Linux-stable-mirror
October 2020
linux-stable-mirror@lists.linaro.org
- 289 participants
- 1294 discussions
stable-rc/queue/5.8 baseline: 205 runs, 2 regressions (v5.8.16-632-g35e3ec0c7174)
by kernelci.org bot
stable-rc/queue/5.8 baseline: 205 runs, 2 regressions (v5.8.16-632-g35e3ec0c7174)
Regressions Summary
-------------------
platform | arch | lab | compiler | defconfig | regressions
----------------+-------+--------------+----------+--------------------+------------
imx8mp-evk | arm64 | lab-nxp | gcc-8 | defconfig | 1
stm32mp157c-dk2 | arm | lab-baylibre | gcc-8 | multi_v7_defconfig | 1
Details: https://kernelci.org/test/job/stable-rc/branch/queue%2F5.8/kernel/v5.8.16-6…
Test: baseline
Tree: stable-rc
Branch: queue/5.8
Describe: v5.8.16-632-g35e3ec0c7174
URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git
SHA: 35e3ec0c7174453dd4892c5edafb86b2db216ddd
Test Regressions
----------------
platform | arch | lab | compiler | defconfig | regressions
----------------+-------+--------------+----------+--------------------+------------
imx8mp-evk | arm64 | lab-nxp | gcc-8 | defconfig | 1
Details: https://kernelci.org/test/plan/id/5f9a902f505558bcf738102d
Results: 0 PASS, 1 FAIL, 0 SKIP
Full config: defconfig
Compiler: gcc-8 (aarch64-linux-gnu-gcc (Debian 8.3.0-2) 8.3.0)
Plain log: https://storage.kernelci.org//stable-rc/queue-5.8/v5.8.16-632-g35e3ec0c7174…
HTML log: https://storage.kernelci.org//stable-rc/queue-5.8/v5.8.16-632-g35e3ec0c7174…
Rootfs: http://storage.kernelci.org/images/rootfs/buildroot/kci-2020.05-4-g97706c5d…
* baseline.login: https://kernelci.org/test/case/id/5f9a902f505558bcf738102e
failing since 2 days (last pass: v5.8.16-626-gbc7f19da4ffe, first fail: v5.8.16-627-ga9047ecdbcb4)
platform | arch | lab | compiler | defconfig | regressions
----------------+-------+--------------+----------+--------------------+------------
stm32mp157c-dk2 | arm | lab-baylibre | gcc-8 | multi_v7_defconfig | 1
Details: https://kernelci.org/test/plan/id/5f9a8c870b532f6d7b381028
Results: 0 PASS, 1 FAIL, 0 SKIP
Full config: multi_v7_defconfig
Compiler: gcc-8 (arm-linux-gnueabihf-gcc (Debian 8.3.0-2) 8.3.0)
Plain log: https://storage.kernelci.org//stable-rc/queue-5.8/v5.8.16-632-g35e3ec0c7174…
HTML log: https://storage.kernelci.org//stable-rc/queue-5.8/v5.8.16-632-g35e3ec0c7174…
Rootfs: http://storage.kernelci.org/images/rootfs/buildroot/kci-2020.05-4-g97706c5d…
* baseline.login: https://kernelci.org/test/case/id/5f9a8c870b532f6d7b381029
failing since 3 days (last pass: v5.8.16-78-g480e444094c4, first fail: v5.8.16-626-g41d0d5713799)
4 years, 3 months
- 1
- 0
FAILED: patch "[PATCH] x86/copy_mc: Introduce copy_mc_enhanced_fast_string()" failed to apply to 4.9-stable tree
by gregkh＠linuxfoundation.org
The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 5da8e4a658109e3b7e1f45ae672b7c06ac3e7158 Mon Sep 17 00:00:00 2001
From: Dan Williams <dan.j.williams(a)intel.com>
Date: Mon, 5 Oct 2020 20:40:25 -0700
Subject: [PATCH] x86/copy_mc: Introduce copy_mc_enhanced_fast_string()
The motivations to go rework memcpy_mcsafe() are that the benefit of
doing slow and careful copies is obviated on newer CPUs, and that the
current opt-in list of CPUs to instrument recovery is broken relative to
those CPUs. There is no need to keep an opt-in list up to date on an
ongoing basis if pmem/dax operations are instrumented for recovery by
default. With recovery enabled by default the old "mcsafe_key" opt-in to
careful copying can be made a "fragile" opt-out. Where the "fragile"
list takes steps to not consume poison across cachelines.
The discussion with Linus made clear that the current "_mcsafe" suffix
was imprecise to a fault. The operations that are needed by pmem/dax are
to copy from a source address that might throw #MC to a destination that
may write-fault, if it is a user page.
So copy_to_user_mcsafe() becomes copy_mc_to_user() to indicate
the separate precautions taken on source and destination.
copy_mc_to_kernel() is introduced as a non-SMAP version that does not
expect write-faults on the destination, but is still prepared to abort
with an error code upon taking #MC.
The original copy_mc_fragile() implementation had negative performance
implications since it did not use the fast-string instruction sequence
to perform copies. For this reason copy_mc_to_kernel() fell back to
plain memcpy() to preserve performance on platforms that did not indicate
the capability to recover from machine check exceptions. However, that
capability detection was not architectural and now that some platforms
can recover from fast-string consumption of memory errors the memcpy()
fallback now causes these more capable platforms to fail.
Introduce copy_mc_enhanced_fast_string() as the fast default
implementation of copy_mc_to_kernel() and finalize the transition of
copy_mc_fragile() to be a platform quirk to indicate 'copy-carefully'.
With this in place, copy_mc_to_kernel() is fast and recovery-ready by
default regardless of hardware capability.
Thanks to Vivek for identifying that copy_user_generic() is not suitable
as the copy_mc_to_user() backend since the #MC handler explicitly checks
ex_has_fault_handler(). Thanks to the 0day robot for catching a
performance bug in the x86/copy_mc_to_user implementation.
[ bp: Add the "why" for this change from the 0/2th message, massage. ]
Fixes: 92b0729c34ca ("x86/mm, x86/mce: Add memcpy_mcsafe()")
Reported-by: Erwin Tsaur <erwin.tsaur(a)intel.com>
Reported-by: 0day robot <lkp(a)intel.com>
Signed-off-by: Dan Williams <dan.j.williams(a)intel.com>
Signed-off-by: Borislav Petkov <bp(a)suse.de>
Reviewed-by: Tony Luck <tony.luck(a)intel.com>
Tested-by: Erwin Tsaur <erwin.tsaur(a)intel.com>
Cc: <stable(a)vger.kernel.org>
Link: https://lkml.kernel.org/r/160195562556.2163339.18063423034951948973.stgit@d…
diff --git a/arch/x86/lib/copy_mc.c b/arch/x86/lib/copy_mc.c
index 2633635530b7..c13e8c9ee926 100644
--- a/arch/x86/lib/copy_mc.c
+++ b/arch/x86/lib/copy_mc.c
@@ -45,6 +45,8 @@ void enable_copy_mc_fragile(void)
#define copy_mc_fragile_enabled (0)
#endif
+unsigned long copy_mc_enhanced_fast_string(void *dst, const void *src, unsigned len);
+
/**
* copy_mc_to_kernel - memory copy that handles source exceptions
*
@@ -52,9 +54,11 @@ void enable_copy_mc_fragile(void)
* @src: source address
* @len: number of bytes to copy
*
- * Call into the 'fragile' version on systems that have trouble
- * actually do machine check recovery. Everyone else can just
- * use memcpy().
+ * Call into the 'fragile' version on systems that benefit from avoiding
+ * corner case poison consumption scenarios, For example, accessing
+ * poison across 2 cachelines with a single instruction. Almost all
+ * other uses case can use copy_mc_enhanced_fast_string() for a fast
+ * recoverable copy, or fallback to plain memcpy.
*
* Return 0 for success, or number of bytes not copied if there was an
* exception.
@@ -63,6 +67,8 @@ unsigned long __must_check copy_mc_to_kernel(void *dst, const void *src, unsigne
{
if (copy_mc_fragile_enabled)
return copy_mc_fragile(dst, src, len);
+ if (static_cpu_has(X86_FEATURE_ERMS))
+ return copy_mc_enhanced_fast_string(dst, src, len);
memcpy(dst, src, len);
return 0;
}
@@ -72,11 +78,19 @@ unsigned long __must_check copy_mc_to_user(void *dst, const void *src, unsigned
{
unsigned long ret;
- if (!copy_mc_fragile_enabled)
- return copy_user_generic(dst, src, len);
+ if (copy_mc_fragile_enabled) {
+ __uaccess_begin();
+ ret = copy_mc_fragile(dst, src, len);
+ __uaccess_end();
+ return ret;
+ }
+
+ if (static_cpu_has(X86_FEATURE_ERMS)) {
+ __uaccess_begin();
+ ret = copy_mc_enhanced_fast_string(dst, src, len);
+ __uaccess_end();
+ return ret;
+ }
- __uaccess_begin();
- ret = copy_mc_fragile(dst, src, len);
- __uaccess_end();
- return ret;
+ return copy_user_generic(dst, src, len);
}
diff --git a/arch/x86/lib/copy_mc_64.S b/arch/x86/lib/copy_mc_64.S
index c3b613c4544a..892d8915f609 100644
--- a/arch/x86/lib/copy_mc_64.S
+++ b/arch/x86/lib/copy_mc_64.S
@@ -124,4 +124,40 @@ EXPORT_SYMBOL_GPL(copy_mc_fragile)
_ASM_EXTABLE(.L_write_words, .E_write_words)
_ASM_EXTABLE(.L_write_trailing_bytes, .E_trailing_bytes)
#endif /* CONFIG_X86_MCE */
+
+/*
+ * copy_mc_enhanced_fast_string - memory copy with exception handling
+ *
+ * Fast string copy + fault / exception handling. If the CPU does
+ * support machine check exception recovery, but does not support
+ * recovering from fast-string exceptions then this CPU needs to be
+ * added to the copy_mc_fragile_key set of quirks. Otherwise, absent any
+ * machine check recovery support this version should be no slower than
+ * standard memcpy.
+ */
+SYM_FUNC_START(copy_mc_enhanced_fast_string)
+ movq %rdi, %rax
+ movq %rdx, %rcx
+.L_copy:
+ rep movsb
+ /* Copy successful. Return zero */
+ xorl %eax, %eax
+ ret
+SYM_FUNC_END(copy_mc_enhanced_fast_string)
+
+ .section .fixup, "ax"
+.E_copy:
+ /*
+ * On fault %rcx is updated such that the copy instruction could
+ * optionally be restarted at the fault position, i.e. it
+ * contains 'bytes remaining'. A non-zero return indicates error
+ * to copy_mc_generic() users, or indicate short transfers to
+ * user-copy routines.
+ */
+ movq %rcx, %rax
+ ret
+
+ .previous
+
+ _ASM_EXTABLE_FAULT(.L_copy, .E_copy)
#endif /* !CONFIG_UML */
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 893f021fec63..b3e4efcf7ca6 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -550,6 +550,7 @@ static const char *uaccess_safe_builtin[] = {
"csum_partial_copy_generic",
"copy_mc_fragile",
"copy_mc_fragile_handle_tail",
+ "copy_mc_enhanced_fast_string",
"ftrace_likely_update", /* CONFIG_TRACE_BRANCH_PROFILING */
NULL
};
4 years, 3 months
- 1
- 0
FAILED: patch "[PATCH] x86/copy_mc: Introduce copy_mc_enhanced_fast_string()" failed to apply to 4.14-stable tree
by gregkh＠linuxfoundation.org
The patch below does not apply to the 4.14-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 5da8e4a658109e3b7e1f45ae672b7c06ac3e7158 Mon Sep 17 00:00:00 2001
From: Dan Williams <dan.j.williams(a)intel.com>
Date: Mon, 5 Oct 2020 20:40:25 -0700
Subject: [PATCH] x86/copy_mc: Introduce copy_mc_enhanced_fast_string()
The motivations to go rework memcpy_mcsafe() are that the benefit of
doing slow and careful copies is obviated on newer CPUs, and that the
current opt-in list of CPUs to instrument recovery is broken relative to
those CPUs. There is no need to keep an opt-in list up to date on an
ongoing basis if pmem/dax operations are instrumented for recovery by
default. With recovery enabled by default the old "mcsafe_key" opt-in to
careful copying can be made a "fragile" opt-out. Where the "fragile"
list takes steps to not consume poison across cachelines.
The discussion with Linus made clear that the current "_mcsafe" suffix
was imprecise to a fault. The operations that are needed by pmem/dax are
to copy from a source address that might throw #MC to a destination that
may write-fault, if it is a user page.
So copy_to_user_mcsafe() becomes copy_mc_to_user() to indicate
the separate precautions taken on source and destination.
copy_mc_to_kernel() is introduced as a non-SMAP version that does not
expect write-faults on the destination, but is still prepared to abort
with an error code upon taking #MC.
The original copy_mc_fragile() implementation had negative performance
implications since it did not use the fast-string instruction sequence
to perform copies. For this reason copy_mc_to_kernel() fell back to
plain memcpy() to preserve performance on platforms that did not indicate
the capability to recover from machine check exceptions. However, that
capability detection was not architectural and now that some platforms
can recover from fast-string consumption of memory errors the memcpy()
fallback now causes these more capable platforms to fail.
Introduce copy_mc_enhanced_fast_string() as the fast default
implementation of copy_mc_to_kernel() and finalize the transition of
copy_mc_fragile() to be a platform quirk to indicate 'copy-carefully'.
With this in place, copy_mc_to_kernel() is fast and recovery-ready by
default regardless of hardware capability.
Thanks to Vivek for identifying that copy_user_generic() is not suitable
as the copy_mc_to_user() backend since the #MC handler explicitly checks
ex_has_fault_handler(). Thanks to the 0day robot for catching a
performance bug in the x86/copy_mc_to_user implementation.
[ bp: Add the "why" for this change from the 0/2th message, massage. ]
Fixes: 92b0729c34ca ("x86/mm, x86/mce: Add memcpy_mcsafe()")
Reported-by: Erwin Tsaur <erwin.tsaur(a)intel.com>
Reported-by: 0day robot <lkp(a)intel.com>
Signed-off-by: Dan Williams <dan.j.williams(a)intel.com>
Signed-off-by: Borislav Petkov <bp(a)suse.de>
Reviewed-by: Tony Luck <tony.luck(a)intel.com>
Tested-by: Erwin Tsaur <erwin.tsaur(a)intel.com>
Cc: <stable(a)vger.kernel.org>
Link: https://lkml.kernel.org/r/160195562556.2163339.18063423034951948973.stgit@d…
diff --git a/arch/x86/lib/copy_mc.c b/arch/x86/lib/copy_mc.c
index 2633635530b7..c13e8c9ee926 100644
--- a/arch/x86/lib/copy_mc.c
+++ b/arch/x86/lib/copy_mc.c
@@ -45,6 +45,8 @@ void enable_copy_mc_fragile(void)
#define copy_mc_fragile_enabled (0)
#endif
+unsigned long copy_mc_enhanced_fast_string(void *dst, const void *src, unsigned len);
+
/**
* copy_mc_to_kernel - memory copy that handles source exceptions
*
@@ -52,9 +54,11 @@ void enable_copy_mc_fragile(void)
* @src: source address
* @len: number of bytes to copy
*
- * Call into the 'fragile' version on systems that have trouble
- * actually do machine check recovery. Everyone else can just
- * use memcpy().
+ * Call into the 'fragile' version on systems that benefit from avoiding
+ * corner case poison consumption scenarios, For example, accessing
+ * poison across 2 cachelines with a single instruction. Almost all
+ * other uses case can use copy_mc_enhanced_fast_string() for a fast
+ * recoverable copy, or fallback to plain memcpy.
*
* Return 0 for success, or number of bytes not copied if there was an
* exception.
@@ -63,6 +67,8 @@ unsigned long __must_check copy_mc_to_kernel(void *dst, const void *src, unsigne
{
if (copy_mc_fragile_enabled)
return copy_mc_fragile(dst, src, len);
+ if (static_cpu_has(X86_FEATURE_ERMS))
+ return copy_mc_enhanced_fast_string(dst, src, len);
memcpy(dst, src, len);
return 0;
}
@@ -72,11 +78,19 @@ unsigned long __must_check copy_mc_to_user(void *dst, const void *src, unsigned
{
unsigned long ret;
- if (!copy_mc_fragile_enabled)
- return copy_user_generic(dst, src, len);
+ if (copy_mc_fragile_enabled) {
+ __uaccess_begin();
+ ret = copy_mc_fragile(dst, src, len);
+ __uaccess_end();
+ return ret;
+ }
+
+ if (static_cpu_has(X86_FEATURE_ERMS)) {
+ __uaccess_begin();
+ ret = copy_mc_enhanced_fast_string(dst, src, len);
+ __uaccess_end();
+ return ret;
+ }
- __uaccess_begin();
- ret = copy_mc_fragile(dst, src, len);
- __uaccess_end();
- return ret;
+ return copy_user_generic(dst, src, len);
}
diff --git a/arch/x86/lib/copy_mc_64.S b/arch/x86/lib/copy_mc_64.S
index c3b613c4544a..892d8915f609 100644
--- a/arch/x86/lib/copy_mc_64.S
+++ b/arch/x86/lib/copy_mc_64.S
@@ -124,4 +124,40 @@ EXPORT_SYMBOL_GPL(copy_mc_fragile)
_ASM_EXTABLE(.L_write_words, .E_write_words)
_ASM_EXTABLE(.L_write_trailing_bytes, .E_trailing_bytes)
#endif /* CONFIG_X86_MCE */
+
+/*
+ * copy_mc_enhanced_fast_string - memory copy with exception handling
+ *
+ * Fast string copy + fault / exception handling. If the CPU does
+ * support machine check exception recovery, but does not support
+ * recovering from fast-string exceptions then this CPU needs to be
+ * added to the copy_mc_fragile_key set of quirks. Otherwise, absent any
+ * machine check recovery support this version should be no slower than
+ * standard memcpy.
+ */
+SYM_FUNC_START(copy_mc_enhanced_fast_string)
+ movq %rdi, %rax
+ movq %rdx, %rcx
+.L_copy:
+ rep movsb
+ /* Copy successful. Return zero */
+ xorl %eax, %eax
+ ret
+SYM_FUNC_END(copy_mc_enhanced_fast_string)
+
+ .section .fixup, "ax"
+.E_copy:
+ /*
+ * On fault %rcx is updated such that the copy instruction could
+ * optionally be restarted at the fault position, i.e. it
+ * contains 'bytes remaining'. A non-zero return indicates error
+ * to copy_mc_generic() users, or indicate short transfers to
+ * user-copy routines.
+ */
+ movq %rcx, %rax
+ ret
+
+ .previous
+
+ _ASM_EXTABLE_FAULT(.L_copy, .E_copy)
#endif /* !CONFIG_UML */
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 893f021fec63..b3e4efcf7ca6 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -550,6 +550,7 @@ static const char *uaccess_safe_builtin[] = {
"csum_partial_copy_generic",
"copy_mc_fragile",
"copy_mc_fragile_handle_tail",
+ "copy_mc_enhanced_fast_string",
"ftrace_likely_update", /* CONFIG_TRACE_BRANCH_PROFILING */
NULL
};
4 years, 3 months
- 1
- 0
FAILED: patch "[PATCH] x86/copy_mc: Introduce copy_mc_enhanced_fast_string()" failed to apply to 4.19-stable tree
by gregkh＠linuxfoundation.org
The patch below does not apply to the 4.19-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 5da8e4a658109e3b7e1f45ae672b7c06ac3e7158 Mon Sep 17 00:00:00 2001
From: Dan Williams <dan.j.williams(a)intel.com>
Date: Mon, 5 Oct 2020 20:40:25 -0700
Subject: [PATCH] x86/copy_mc: Introduce copy_mc_enhanced_fast_string()
The motivations to go rework memcpy_mcsafe() are that the benefit of
doing slow and careful copies is obviated on newer CPUs, and that the
current opt-in list of CPUs to instrument recovery is broken relative to
those CPUs. There is no need to keep an opt-in list up to date on an
ongoing basis if pmem/dax operations are instrumented for recovery by
default. With recovery enabled by default the old "mcsafe_key" opt-in to
careful copying can be made a "fragile" opt-out. Where the "fragile"
list takes steps to not consume poison across cachelines.
The discussion with Linus made clear that the current "_mcsafe" suffix
was imprecise to a fault. The operations that are needed by pmem/dax are
to copy from a source address that might throw #MC to a destination that
may write-fault, if it is a user page.
So copy_to_user_mcsafe() becomes copy_mc_to_user() to indicate
the separate precautions taken on source and destination.
copy_mc_to_kernel() is introduced as a non-SMAP version that does not
expect write-faults on the destination, but is still prepared to abort
with an error code upon taking #MC.
The original copy_mc_fragile() implementation had negative performance
implications since it did not use the fast-string instruction sequence
to perform copies. For this reason copy_mc_to_kernel() fell back to
plain memcpy() to preserve performance on platforms that did not indicate
the capability to recover from machine check exceptions. However, that
capability detection was not architectural and now that some platforms
can recover from fast-string consumption of memory errors the memcpy()
fallback now causes these more capable platforms to fail.
Introduce copy_mc_enhanced_fast_string() as the fast default
implementation of copy_mc_to_kernel() and finalize the transition of
copy_mc_fragile() to be a platform quirk to indicate 'copy-carefully'.
With this in place, copy_mc_to_kernel() is fast and recovery-ready by
default regardless of hardware capability.
Thanks to Vivek for identifying that copy_user_generic() is not suitable
as the copy_mc_to_user() backend since the #MC handler explicitly checks
ex_has_fault_handler(). Thanks to the 0day robot for catching a
performance bug in the x86/copy_mc_to_user implementation.
[ bp: Add the "why" for this change from the 0/2th message, massage. ]
Fixes: 92b0729c34ca ("x86/mm, x86/mce: Add memcpy_mcsafe()")
Reported-by: Erwin Tsaur <erwin.tsaur(a)intel.com>
Reported-by: 0day robot <lkp(a)intel.com>
Signed-off-by: Dan Williams <dan.j.williams(a)intel.com>
Signed-off-by: Borislav Petkov <bp(a)suse.de>
Reviewed-by: Tony Luck <tony.luck(a)intel.com>
Tested-by: Erwin Tsaur <erwin.tsaur(a)intel.com>
Cc: <stable(a)vger.kernel.org>
Link: https://lkml.kernel.org/r/160195562556.2163339.18063423034951948973.stgit@d…
diff --git a/arch/x86/lib/copy_mc.c b/arch/x86/lib/copy_mc.c
index 2633635530b7..c13e8c9ee926 100644
--- a/arch/x86/lib/copy_mc.c
+++ b/arch/x86/lib/copy_mc.c
@@ -45,6 +45,8 @@ void enable_copy_mc_fragile(void)
#define copy_mc_fragile_enabled (0)
#endif
+unsigned long copy_mc_enhanced_fast_string(void *dst, const void *src, unsigned len);
+
/**
* copy_mc_to_kernel - memory copy that handles source exceptions
*
@@ -52,9 +54,11 @@ void enable_copy_mc_fragile(void)
* @src: source address
* @len: number of bytes to copy
*
- * Call into the 'fragile' version on systems that have trouble
- * actually do machine check recovery. Everyone else can just
- * use memcpy().
+ * Call into the 'fragile' version on systems that benefit from avoiding
+ * corner case poison consumption scenarios, For example, accessing
+ * poison across 2 cachelines with a single instruction. Almost all
+ * other uses case can use copy_mc_enhanced_fast_string() for a fast
+ * recoverable copy, or fallback to plain memcpy.
*
* Return 0 for success, or number of bytes not copied if there was an
* exception.
@@ -63,6 +67,8 @@ unsigned long __must_check copy_mc_to_kernel(void *dst, const void *src, unsigne
{
if (copy_mc_fragile_enabled)
return copy_mc_fragile(dst, src, len);
+ if (static_cpu_has(X86_FEATURE_ERMS))
+ return copy_mc_enhanced_fast_string(dst, src, len);
memcpy(dst, src, len);
return 0;
}
@@ -72,11 +78,19 @@ unsigned long __must_check copy_mc_to_user(void *dst, const void *src, unsigned
{
unsigned long ret;
- if (!copy_mc_fragile_enabled)
- return copy_user_generic(dst, src, len);
+ if (copy_mc_fragile_enabled) {
+ __uaccess_begin();
+ ret = copy_mc_fragile(dst, src, len);
+ __uaccess_end();
+ return ret;
+ }
+
+ if (static_cpu_has(X86_FEATURE_ERMS)) {
+ __uaccess_begin();
+ ret = copy_mc_enhanced_fast_string(dst, src, len);
+ __uaccess_end();
+ return ret;
+ }
- __uaccess_begin();
- ret = copy_mc_fragile(dst, src, len);
- __uaccess_end();
- return ret;
+ return copy_user_generic(dst, src, len);
}
diff --git a/arch/x86/lib/copy_mc_64.S b/arch/x86/lib/copy_mc_64.S
index c3b613c4544a..892d8915f609 100644
--- a/arch/x86/lib/copy_mc_64.S
+++ b/arch/x86/lib/copy_mc_64.S
@@ -124,4 +124,40 @@ EXPORT_SYMBOL_GPL(copy_mc_fragile)
_ASM_EXTABLE(.L_write_words, .E_write_words)
_ASM_EXTABLE(.L_write_trailing_bytes, .E_trailing_bytes)
#endif /* CONFIG_X86_MCE */
+
+/*
+ * copy_mc_enhanced_fast_string - memory copy with exception handling
+ *
+ * Fast string copy + fault / exception handling. If the CPU does
+ * support machine check exception recovery, but does not support
+ * recovering from fast-string exceptions then this CPU needs to be
+ * added to the copy_mc_fragile_key set of quirks. Otherwise, absent any
+ * machine check recovery support this version should be no slower than
+ * standard memcpy.
+ */
+SYM_FUNC_START(copy_mc_enhanced_fast_string)
+ movq %rdi, %rax
+ movq %rdx, %rcx
+.L_copy:
+ rep movsb
+ /* Copy successful. Return zero */
+ xorl %eax, %eax
+ ret
+SYM_FUNC_END(copy_mc_enhanced_fast_string)
+
+ .section .fixup, "ax"
+.E_copy:
+ /*
+ * On fault %rcx is updated such that the copy instruction could
+ * optionally be restarted at the fault position, i.e. it
+ * contains 'bytes remaining'. A non-zero return indicates error
+ * to copy_mc_generic() users, or indicate short transfers to
+ * user-copy routines.
+ */
+ movq %rcx, %rax
+ ret
+
+ .previous
+
+ _ASM_EXTABLE_FAULT(.L_copy, .E_copy)
#endif /* !CONFIG_UML */
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 893f021fec63..b3e4efcf7ca6 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -550,6 +550,7 @@ static const char *uaccess_safe_builtin[] = {
"csum_partial_copy_generic",
"copy_mc_fragile",
"copy_mc_fragile_handle_tail",
+ "copy_mc_enhanced_fast_string",
"ftrace_likely_update", /* CONFIG_TRACE_BRANCH_PROFILING */
NULL
};
4 years, 3 months
- 1
- 0
FAILED: patch "[PATCH] x86/copy_mc: Introduce copy_mc_enhanced_fast_string()" failed to apply to 5.4-stable tree
by gregkh＠linuxfoundation.org
The patch below does not apply to the 5.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 5da8e4a658109e3b7e1f45ae672b7c06ac3e7158 Mon Sep 17 00:00:00 2001
From: Dan Williams <dan.j.williams(a)intel.com>
Date: Mon, 5 Oct 2020 20:40:25 -0700
Subject: [PATCH] x86/copy_mc: Introduce copy_mc_enhanced_fast_string()
The motivations to go rework memcpy_mcsafe() are that the benefit of
doing slow and careful copies is obviated on newer CPUs, and that the
current opt-in list of CPUs to instrument recovery is broken relative to
those CPUs. There is no need to keep an opt-in list up to date on an
ongoing basis if pmem/dax operations are instrumented for recovery by
default. With recovery enabled by default the old "mcsafe_key" opt-in to
careful copying can be made a "fragile" opt-out. Where the "fragile"
list takes steps to not consume poison across cachelines.
The discussion with Linus made clear that the current "_mcsafe" suffix
was imprecise to a fault. The operations that are needed by pmem/dax are
to copy from a source address that might throw #MC to a destination that
may write-fault, if it is a user page.
So copy_to_user_mcsafe() becomes copy_mc_to_user() to indicate
the separate precautions taken on source and destination.
copy_mc_to_kernel() is introduced as a non-SMAP version that does not
expect write-faults on the destination, but is still prepared to abort
with an error code upon taking #MC.
The original copy_mc_fragile() implementation had negative performance
implications since it did not use the fast-string instruction sequence
to perform copies. For this reason copy_mc_to_kernel() fell back to
plain memcpy() to preserve performance on platforms that did not indicate
the capability to recover from machine check exceptions. However, that
capability detection was not architectural and now that some platforms
can recover from fast-string consumption of memory errors the memcpy()
fallback now causes these more capable platforms to fail.
Introduce copy_mc_enhanced_fast_string() as the fast default
implementation of copy_mc_to_kernel() and finalize the transition of
copy_mc_fragile() to be a platform quirk to indicate 'copy-carefully'.
With this in place, copy_mc_to_kernel() is fast and recovery-ready by
default regardless of hardware capability.
Thanks to Vivek for identifying that copy_user_generic() is not suitable
as the copy_mc_to_user() backend since the #MC handler explicitly checks
ex_has_fault_handler(). Thanks to the 0day robot for catching a
performance bug in the x86/copy_mc_to_user implementation.
[ bp: Add the "why" for this change from the 0/2th message, massage. ]
Fixes: 92b0729c34ca ("x86/mm, x86/mce: Add memcpy_mcsafe()")
Reported-by: Erwin Tsaur <erwin.tsaur(a)intel.com>
Reported-by: 0day robot <lkp(a)intel.com>
Signed-off-by: Dan Williams <dan.j.williams(a)intel.com>
Signed-off-by: Borislav Petkov <bp(a)suse.de>
Reviewed-by: Tony Luck <tony.luck(a)intel.com>
Tested-by: Erwin Tsaur <erwin.tsaur(a)intel.com>
Cc: <stable(a)vger.kernel.org>
Link: https://lkml.kernel.org/r/160195562556.2163339.18063423034951948973.stgit@d…
diff --git a/arch/x86/lib/copy_mc.c b/arch/x86/lib/copy_mc.c
index 2633635530b7..c13e8c9ee926 100644
--- a/arch/x86/lib/copy_mc.c
+++ b/arch/x86/lib/copy_mc.c
@@ -45,6 +45,8 @@ void enable_copy_mc_fragile(void)
#define copy_mc_fragile_enabled (0)
#endif
+unsigned long copy_mc_enhanced_fast_string(void *dst, const void *src, unsigned len);
+
/**
* copy_mc_to_kernel - memory copy that handles source exceptions
*
@@ -52,9 +54,11 @@ void enable_copy_mc_fragile(void)
* @src: source address
* @len: number of bytes to copy
*
- * Call into the 'fragile' version on systems that have trouble
- * actually do machine check recovery. Everyone else can just
- * use memcpy().
+ * Call into the 'fragile' version on systems that benefit from avoiding
+ * corner case poison consumption scenarios, For example, accessing
+ * poison across 2 cachelines with a single instruction. Almost all
+ * other uses case can use copy_mc_enhanced_fast_string() for a fast
+ * recoverable copy, or fallback to plain memcpy.
*
* Return 0 for success, or number of bytes not copied if there was an
* exception.
@@ -63,6 +67,8 @@ unsigned long __must_check copy_mc_to_kernel(void *dst, const void *src, unsigne
{
if (copy_mc_fragile_enabled)
return copy_mc_fragile(dst, src, len);
+ if (static_cpu_has(X86_FEATURE_ERMS))
+ return copy_mc_enhanced_fast_string(dst, src, len);
memcpy(dst, src, len);
return 0;
}
@@ -72,11 +78,19 @@ unsigned long __must_check copy_mc_to_user(void *dst, const void *src, unsigned
{
unsigned long ret;
- if (!copy_mc_fragile_enabled)
- return copy_user_generic(dst, src, len);
+ if (copy_mc_fragile_enabled) {
+ __uaccess_begin();
+ ret = copy_mc_fragile(dst, src, len);
+ __uaccess_end();
+ return ret;
+ }
+
+ if (static_cpu_has(X86_FEATURE_ERMS)) {
+ __uaccess_begin();
+ ret = copy_mc_enhanced_fast_string(dst, src, len);
+ __uaccess_end();
+ return ret;
+ }
- __uaccess_begin();
- ret = copy_mc_fragile(dst, src, len);
- __uaccess_end();
- return ret;
+ return copy_user_generic(dst, src, len);
}
diff --git a/arch/x86/lib/copy_mc_64.S b/arch/x86/lib/copy_mc_64.S
index c3b613c4544a..892d8915f609 100644
--- a/arch/x86/lib/copy_mc_64.S
+++ b/arch/x86/lib/copy_mc_64.S
@@ -124,4 +124,40 @@ EXPORT_SYMBOL_GPL(copy_mc_fragile)
_ASM_EXTABLE(.L_write_words, .E_write_words)
_ASM_EXTABLE(.L_write_trailing_bytes, .E_trailing_bytes)
#endif /* CONFIG_X86_MCE */
+
+/*
+ * copy_mc_enhanced_fast_string - memory copy with exception handling
+ *
+ * Fast string copy + fault / exception handling. If the CPU does
+ * support machine check exception recovery, but does not support
+ * recovering from fast-string exceptions then this CPU needs to be
+ * added to the copy_mc_fragile_key set of quirks. Otherwise, absent any
+ * machine check recovery support this version should be no slower than
+ * standard memcpy.
+ */
+SYM_FUNC_START(copy_mc_enhanced_fast_string)
+ movq %rdi, %rax
+ movq %rdx, %rcx
+.L_copy:
+ rep movsb
+ /* Copy successful. Return zero */
+ xorl %eax, %eax
+ ret
+SYM_FUNC_END(copy_mc_enhanced_fast_string)
+
+ .section .fixup, "ax"
+.E_copy:
+ /*
+ * On fault %rcx is updated such that the copy instruction could
+ * optionally be restarted at the fault position, i.e. it
+ * contains 'bytes remaining'. A non-zero return indicates error
+ * to copy_mc_generic() users, or indicate short transfers to
+ * user-copy routines.
+ */
+ movq %rcx, %rax
+ ret
+
+ .previous
+
+ _ASM_EXTABLE_FAULT(.L_copy, .E_copy)
#endif /* !CONFIG_UML */
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 893f021fec63..b3e4efcf7ca6 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -550,6 +550,7 @@ static const char *uaccess_safe_builtin[] = {
"csum_partial_copy_generic",
"copy_mc_fragile",
"copy_mc_fragile_handle_tail",
+ "copy_mc_enhanced_fast_string",
"ftrace_likely_update", /* CONFIG_TRACE_BRANCH_PROFILING */
NULL
};
4 years, 3 months
- 1
- 0
FAILED: patch "[PATCH] x86, powerpc: Rename memcpy_mcsafe() to copy_mc_to_{user, " failed to apply to 4.9-stable tree
by gregkh＠linuxfoundation.org
The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From ec6347bb43395cb92126788a1a5b25302543f815 Mon Sep 17 00:00:00 2001
From: Dan Williams <dan.j.williams(a)intel.com>
Date: Mon, 5 Oct 2020 20:40:16 -0700
Subject: [PATCH] x86, powerpc: Rename memcpy_mcsafe() to copy_mc_to_{user,
kernel}()
In reaction to a proposal to introduce a memcpy_mcsafe_fast()
implementation Linus points out that memcpy_mcsafe() is poorly named
relative to communicating the scope of the interface. Specifically what
addresses are valid to pass as source, destination, and what faults /
exceptions are handled.
Of particular concern is that even though x86 might be able to handle
the semantics of copy_mc_to_user() with its common copy_user_generic()
implementation other archs likely need / want an explicit path for this
case:
On Fri, May 1, 2020 at 11:28 AM Linus Torvalds <torvalds(a)linux-foundation.org> wrote:
>
> On Thu, Apr 30, 2020 at 6:21 PM Dan Williams <dan.j.williams(a)intel.com> wrote:
> >
> > However now I see that copy_user_generic() works for the wrong reason.
> > It works because the exception on the source address due to poison
> > looks no different than a write fault on the user address to the
> > caller, it's still just a short copy. So it makes copy_to_user() work
> > for the wrong reason relative to the name.
>
> Right.
>
> And it won't work that way on other architectures. On x86, we have a
> generic function that can take faults on either side, and we use it
> for both cases (and for the "in_user" case too), but that's an
> artifact of the architecture oddity.
>
> In fact, it's probably wrong even on x86 - because it can hide bugs -
> but writing those things is painful enough that everybody prefers
> having just one function.
Replace a single top-level memcpy_mcsafe() with either
copy_mc_to_user(), or copy_mc_to_kernel().
Introduce an x86 copy_mc_fragile() name as the rename for the
low-level x86 implementation formerly named memcpy_mcsafe(). It is used
as the slow / careful backend that is supplanted by a fast
copy_mc_generic() in a follow-on patch.
One side-effect of this reorganization is that separating copy_mc_64.S
to its own file means that perf no longer needs to track dependencies
for its memcpy_64.S benchmarks.
[ bp: Massage a bit. ]
Signed-off-by: Dan Williams <dan.j.williams(a)intel.com>
Signed-off-by: Borislav Petkov <bp(a)suse.de>
Reviewed-by: Tony Luck <tony.luck(a)intel.com>
Acked-by: Michael Ellerman <mpe(a)ellerman.id.au>
Cc: <stable(a)vger.kernel.org>
Link: http://lore.kernel.org/r/CAHk-=wjSqtXAqfUJxFtWNwmguFASTgB0dz1dT3V-78Quiezqb…
Link: https://lkml.kernel.org/r/160195561680.2163339.11574962055305783722.stgit@d…
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 1f48bbfb3ce9..76473eda3426 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -136,7 +136,7 @@ config PPC
select ARCH_HAS_STRICT_KERNEL_RWX if (PPC32 && !HIBERNATION)
select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
select ARCH_HAS_UACCESS_FLUSHCACHE
- select ARCH_HAS_UACCESS_MCSAFE if PPC64
+ select ARCH_HAS_COPY_MC if PPC64
select ARCH_HAS_UBSAN_SANITIZE_ALL
select ARCH_HAVE_NMI_SAFE_CMPXCHG
select ARCH_KEEP_MEMBLOCK
diff --git a/arch/powerpc/include/asm/string.h b/arch/powerpc/include/asm/string.h
index 283552cd0e58..2aa0e31e6884 100644
--- a/arch/powerpc/include/asm/string.h
+++ b/arch/powerpc/include/asm/string.h
@@ -53,9 +53,7 @@ void *__memmove(void *to, const void *from, __kernel_size_t n);
#ifndef CONFIG_KASAN
#define __HAVE_ARCH_MEMSET32
#define __HAVE_ARCH_MEMSET64
-#define __HAVE_ARCH_MEMCPY_MCSAFE
-extern int memcpy_mcsafe(void *dst, const void *src, __kernel_size_t sz);
extern void *__memset16(uint16_t *, uint16_t v, __kernel_size_t);
extern void *__memset32(uint32_t *, uint32_t v, __kernel_size_t);
extern void *__memset64(uint64_t *, uint64_t v, __kernel_size_t);
diff --git a/arch/powerpc/include/asm/uaccess.h b/arch/powerpc/include/asm/uaccess.h
index 00699903f1ef..20a35373cafc 100644
--- a/arch/powerpc/include/asm/uaccess.h
+++ b/arch/powerpc/include/asm/uaccess.h
@@ -435,6 +435,32 @@ do { \
extern unsigned long __copy_tofrom_user(void __user *to,
const void __user *from, unsigned long size);
+#ifdef CONFIG_ARCH_HAS_COPY_MC
+unsigned long __must_check
+copy_mc_generic(void *to, const void *from, unsigned long size);
+
+static inline unsigned long __must_check
+copy_mc_to_kernel(void *to, const void *from, unsigned long size)
+{
+ return copy_mc_generic(to, from, size);
+}
+#define copy_mc_to_kernel copy_mc_to_kernel
+
+static inline unsigned long __must_check
+copy_mc_to_user(void __user *to, const void *from, unsigned long n)
+{
+ if (likely(check_copy_size(from, n, true))) {
+ if (access_ok(to, n)) {
+ allow_write_to_user(to, n);
+ n = copy_mc_generic((void *)to, from, n);
+ prevent_write_to_user(to, n);
+ }
+ }
+
+ return n;
+}
+#endif
+
#ifdef __powerpc64__
static inline unsigned long
raw_copy_in_user(void __user *to, const void __user *from, unsigned long n)
@@ -523,20 +549,6 @@ raw_copy_to_user(void __user *to, const void *from, unsigned long n)
return ret;
}
-static __always_inline unsigned long __must_check
-copy_to_user_mcsafe(void __user *to, const void *from, unsigned long n)
-{
- if (likely(check_copy_size(from, n, true))) {
- if (access_ok(to, n)) {
- allow_write_to_user(to, n);
- n = memcpy_mcsafe((void *)to, from, n);
- prevent_write_to_user(to, n);
- }
- }
-
- return n;
-}
-
unsigned long __arch_clear_user(void __user *addr, unsigned long size);
static inline unsigned long clear_user(void __user *addr, unsigned long size)
diff --git a/arch/powerpc/lib/Makefile b/arch/powerpc/lib/Makefile
index d66a645503eb..69a91b571845 100644
--- a/arch/powerpc/lib/Makefile
+++ b/arch/powerpc/lib/Makefile
@@ -39,7 +39,7 @@ obj-$(CONFIG_PPC_BOOK3S_64) += copyuser_power7.o copypage_power7.o \
memcpy_power7.o
obj64-y += copypage_64.o copyuser_64.o mem_64.o hweight_64.o \
- memcpy_64.o memcpy_mcsafe_64.o
+ memcpy_64.o copy_mc_64.o
ifndef CONFIG_PPC_QUEUED_SPINLOCKS
obj64-$(CONFIG_SMP) += locks.o
diff --git a/arch/powerpc/lib/memcpy_mcsafe_64.S b/arch/powerpc/lib/copy_mc_64.S
similarity index 98%
rename from arch/powerpc/lib/memcpy_mcsafe_64.S
rename to arch/powerpc/lib/copy_mc_64.S
index cb882d9a6d8a..88d46c471493 100644
--- a/arch/powerpc/lib/memcpy_mcsafe_64.S
+++ b/arch/powerpc/lib/copy_mc_64.S
@@ -50,7 +50,7 @@ err3; stb r0,0(r3)
blr
-_GLOBAL(memcpy_mcsafe)
+_GLOBAL(copy_mc_generic)
mr r7,r5
cmpldi r5,16
blt .Lshort_copy
@@ -239,4 +239,4 @@ err1; stb r0,0(r3)
15: li r3,0
blr
-EXPORT_SYMBOL_GPL(memcpy_mcsafe);
+EXPORT_SYMBOL_GPL(copy_mc_generic);
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 7101ac64bb20..e876b3a087f9 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -75,7 +75,7 @@ config X86
select ARCH_HAS_PTE_DEVMAP if X86_64
select ARCH_HAS_PTE_SPECIAL
select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64
- select ARCH_HAS_UACCESS_MCSAFE if X86_64 && X86_MCE
+ select ARCH_HAS_COPY_MC if X86_64
select ARCH_HAS_SET_MEMORY
select ARCH_HAS_SET_DIRECT_MAP
select ARCH_HAS_STRICT_KERNEL_RWX
diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug
index ee1d3c5834c6..27b5e2bc6a01 100644
--- a/arch/x86/Kconfig.debug
+++ b/arch/x86/Kconfig.debug
@@ -62,7 +62,7 @@ config EARLY_PRINTK_USB_XDBC
You should normally say N here, unless you want to debug early
crashes or need a very simple printk logging facility.
-config MCSAFE_TEST
+config COPY_MC_TEST
def_bool n
config EFI_PGT_DUMP
diff --git a/arch/x86/include/asm/copy_mc_test.h b/arch/x86/include/asm/copy_mc_test.h
new file mode 100644
index 000000000000..e4991ba96726
--- /dev/null
+++ b/arch/x86/include/asm/copy_mc_test.h
@@ -0,0 +1,75 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _COPY_MC_TEST_H_
+#define _COPY_MC_TEST_H_
+
+#ifndef __ASSEMBLY__
+#ifdef CONFIG_COPY_MC_TEST
+extern unsigned long copy_mc_test_src;
+extern unsigned long copy_mc_test_dst;
+
+static inline void copy_mc_inject_src(void *addr)
+{
+ if (addr)
+ copy_mc_test_src = (unsigned long) addr;
+ else
+ copy_mc_test_src = ~0UL;
+}
+
+static inline void copy_mc_inject_dst(void *addr)
+{
+ if (addr)
+ copy_mc_test_dst = (unsigned long) addr;
+ else
+ copy_mc_test_dst = ~0UL;
+}
+#else /* CONFIG_COPY_MC_TEST */
+static inline void copy_mc_inject_src(void *addr)
+{
+}
+
+static inline void copy_mc_inject_dst(void *addr)
+{
+}
+#endif /* CONFIG_COPY_MC_TEST */
+
+#else /* __ASSEMBLY__ */
+#include <asm/export.h>
+
+#ifdef CONFIG_COPY_MC_TEST
+.macro COPY_MC_TEST_CTL
+ .pushsection .data
+ .align 8
+ .globl copy_mc_test_src
+ copy_mc_test_src:
+ .quad 0
+ EXPORT_SYMBOL_GPL(copy_mc_test_src)
+ .globl copy_mc_test_dst
+ copy_mc_test_dst:
+ .quad 0
+ EXPORT_SYMBOL_GPL(copy_mc_test_dst)
+ .popsection
+.endm
+
+.macro COPY_MC_TEST_SRC reg count target
+ leaq \count(\reg), %r9
+ cmp copy_mc_test_src, %r9
+ ja \target
+.endm
+
+.macro COPY_MC_TEST_DST reg count target
+ leaq \count(\reg), %r9
+ cmp copy_mc_test_dst, %r9
+ ja \target
+.endm
+#else
+.macro COPY_MC_TEST_CTL
+.endm
+
+.macro COPY_MC_TEST_SRC reg count target
+.endm
+
+.macro COPY_MC_TEST_DST reg count target
+.endm
+#endif /* CONFIG_COPY_MC_TEST */
+#endif /* __ASSEMBLY__ */
+#endif /* _COPY_MC_TEST_H_ */
diff --git a/arch/x86/include/asm/mce.h b/arch/x86/include/asm/mce.h
index 109af5c7f515..ba2062d6df92 100644
--- a/arch/x86/include/asm/mce.h
+++ b/arch/x86/include/asm/mce.h
@@ -174,6 +174,15 @@ extern void mce_unregister_decode_chain(struct notifier_block *nb);
extern int mce_p5_enabled;
+#ifdef CONFIG_ARCH_HAS_COPY_MC
+extern void enable_copy_mc_fragile(void);
+unsigned long __must_check copy_mc_fragile(void *dst, const void *src, unsigned cnt);
+#else
+static inline void enable_copy_mc_fragile(void)
+{
+}
+#endif
+
#ifdef CONFIG_X86_MCE
int mcheck_init(void);
void mcheck_cpu_init(struct cpuinfo_x86 *c);
diff --git a/arch/x86/include/asm/mcsafe_test.h b/arch/x86/include/asm/mcsafe_test.h
deleted file mode 100644
index eb59804b6201..000000000000
--- a/arch/x86/include/asm/mcsafe_test.h
+++ /dev/null
@@ -1,75 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef _MCSAFE_TEST_H_
-#define _MCSAFE_TEST_H_
-
-#ifndef __ASSEMBLY__
-#ifdef CONFIG_MCSAFE_TEST
-extern unsigned long mcsafe_test_src;
-extern unsigned long mcsafe_test_dst;
-
-static inline void mcsafe_inject_src(void *addr)
-{
- if (addr)
- mcsafe_test_src = (unsigned long) addr;
- else
- mcsafe_test_src = ~0UL;
-}
-
-static inline void mcsafe_inject_dst(void *addr)
-{
- if (addr)
- mcsafe_test_dst = (unsigned long) addr;
- else
- mcsafe_test_dst = ~0UL;
-}
-#else /* CONFIG_MCSAFE_TEST */
-static inline void mcsafe_inject_src(void *addr)
-{
-}
-
-static inline void mcsafe_inject_dst(void *addr)
-{
-}
-#endif /* CONFIG_MCSAFE_TEST */
-
-#else /* __ASSEMBLY__ */
-#include <asm/export.h>
-
-#ifdef CONFIG_MCSAFE_TEST
-.macro MCSAFE_TEST_CTL
- .pushsection .data
- .align 8
- .globl mcsafe_test_src
- mcsafe_test_src:
- .quad 0
- EXPORT_SYMBOL_GPL(mcsafe_test_src)
- .globl mcsafe_test_dst
- mcsafe_test_dst:
- .quad 0
- EXPORT_SYMBOL_GPL(mcsafe_test_dst)
- .popsection
-.endm
-
-.macro MCSAFE_TEST_SRC reg count target
- leaq \count(\reg), %r9
- cmp mcsafe_test_src, %r9
- ja \target
-.endm
-
-.macro MCSAFE_TEST_DST reg count target
- leaq \count(\reg), %r9
- cmp mcsafe_test_dst, %r9
- ja \target
-.endm
-#else
-.macro MCSAFE_TEST_CTL
-.endm
-
-.macro MCSAFE_TEST_SRC reg count target
-.endm
-
-.macro MCSAFE_TEST_DST reg count target
-.endm
-#endif /* CONFIG_MCSAFE_TEST */
-#endif /* __ASSEMBLY__ */
-#endif /* _MCSAFE_TEST_H_ */
diff --git a/arch/x86/include/asm/string_64.h b/arch/x86/include/asm/string_64.h
index 75314c3dbe47..6e450827f677 100644
--- a/arch/x86/include/asm/string_64.h
+++ b/arch/x86/include/asm/string_64.h
@@ -82,38 +82,6 @@ int strcmp(const char *cs, const char *ct);
#endif
-#define __HAVE_ARCH_MEMCPY_MCSAFE 1
-__must_check unsigned long __memcpy_mcsafe(void *dst, const void *src,
- size_t cnt);
-DECLARE_STATIC_KEY_FALSE(mcsafe_key);
-
-/**
- * memcpy_mcsafe - copy memory with indication if a machine check happened
- *
- * @dst: destination address
- * @src: source address
- * @cnt: number of bytes to copy
- *
- * Low level memory copy function that catches machine checks
- * We only call into the "safe" function on systems that can
- * actually do machine check recovery. Everyone else can just
- * use memcpy().
- *
- * Return 0 for success, or number of bytes not copied if there was an
- * exception.
- */
-static __always_inline __must_check unsigned long
-memcpy_mcsafe(void *dst, const void *src, size_t cnt)
-{
-#ifdef CONFIG_X86_MCE
- if (static_branch_unlikely(&mcsafe_key))
- return __memcpy_mcsafe(dst, src, cnt);
- else
-#endif
- memcpy(dst, src, cnt);
- return 0;
-}
-
#ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE
#define __HAVE_ARCH_MEMCPY_FLUSHCACHE 1
void __memcpy_flushcache(void *dst, const void *src, size_t cnt);
diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h
index ecefaffd15d4..eff7fb847149 100644
--- a/arch/x86/include/asm/uaccess.h
+++ b/arch/x86/include/asm/uaccess.h
@@ -455,6 +455,15 @@ extern __must_check long strnlen_user(const char __user *str, long n);
unsigned long __must_check clear_user(void __user *mem, unsigned long len);
unsigned long __must_check __clear_user(void __user *mem, unsigned long len);
+#ifdef CONFIG_ARCH_HAS_COPY_MC
+unsigned long __must_check
+copy_mc_to_kernel(void *to, const void *from, unsigned len);
+#define copy_mc_to_kernel copy_mc_to_kernel
+
+unsigned long __must_check
+copy_mc_to_user(void *to, const void *from, unsigned len);
+#endif
+
/*
* movsl can be slow when source and dest are not both 8-byte aligned
*/
diff --git a/arch/x86/include/asm/uaccess_64.h b/arch/x86/include/asm/uaccess_64.h
index bc10e3dc64fe..e7265a552f4f 100644
--- a/arch/x86/include/asm/uaccess_64.h
+++ b/arch/x86/include/asm/uaccess_64.h
@@ -46,22 +46,6 @@ copy_user_generic(void *to, const void *from, unsigned len)
return ret;
}
-static __always_inline __must_check unsigned long
-copy_to_user_mcsafe(void *to, const void *from, unsigned len)
-{
- unsigned long ret;
-
- __uaccess_begin();
- /*
- * Note, __memcpy_mcsafe() is explicitly used since it can
- * handle exceptions / faults. memcpy_mcsafe() may fall back to
- * memcpy() which lacks this handling.
- */
- ret = __memcpy_mcsafe(to, from, len);
- __uaccess_end();
- return ret;
-}
-
static __always_inline __must_check unsigned long
raw_copy_from_user(void *dst, const void __user *src, unsigned long size)
{
@@ -102,8 +86,4 @@ __copy_from_user_flushcache(void *dst, const void __user *src, unsigned size)
kasan_check_write(dst, size);
return __copy_user_flushcache(dst, src, size);
}
-
-unsigned long
-mcsafe_handle_tail(char *to, char *from, unsigned len);
-
#endif /* _ASM_X86_UACCESS_64_H */
diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c
index 11b6697be010..b5b70f4b351d 100644
--- a/arch/x86/kernel/cpu/mce/core.c
+++ b/arch/x86/kernel/cpu/mce/core.c
@@ -40,7 +40,6 @@
#include <linux/debugfs.h>
#include <linux/irq_work.h>
#include <linux/export.h>
-#include <linux/jump_label.h>
#include <linux/set_memory.h>
#include <linux/sync_core.h>
#include <linux/task_work.h>
@@ -2124,7 +2123,7 @@ void mce_disable_bank(int bank)
and older.
* mce=nobootlog Don't log MCEs from before booting.
* mce=bios_cmci_threshold Don't program the CMCI threshold
- * mce=recovery force enable memcpy_mcsafe()
+ * mce=recovery force enable copy_mc_fragile()
*/
static int __init mcheck_enable(char *str)
{
@@ -2732,13 +2731,10 @@ static void __init mcheck_debugfs_init(void)
static void __init mcheck_debugfs_init(void) { }
#endif
-DEFINE_STATIC_KEY_FALSE(mcsafe_key);
-EXPORT_SYMBOL_GPL(mcsafe_key);
-
static int __init mcheck_late_init(void)
{
if (mca_cfg.recovery)
- static_branch_inc(&mcsafe_key);
+ enable_copy_mc_fragile();
mcheck_debugfs_init();
diff --git a/arch/x86/kernel/quirks.c b/arch/x86/kernel/quirks.c
index 1b10717c9321..6d0df6a58873 100644
--- a/arch/x86/kernel/quirks.c
+++ b/arch/x86/kernel/quirks.c
@@ -8,6 +8,7 @@
#include <asm/hpet.h>
#include <asm/setup.h>
+#include <asm/mce.h>
#if defined(CONFIG_X86_IO_APIC) && defined(CONFIG_SMP) && defined(CONFIG_PCI)
@@ -624,10 +625,6 @@ static void amd_disable_seq_and_redirect_scrub(struct pci_dev *dev)
DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_16H_NB_F3,
amd_disable_seq_and_redirect_scrub);
-#if defined(CONFIG_X86_64) && defined(CONFIG_X86_MCE)
-#include <linux/jump_label.h>
-#include <asm/string_64.h>
-
/* Ivy Bridge, Haswell, Broadwell */
static void quirk_intel_brickland_xeon_ras_cap(struct pci_dev *pdev)
{
@@ -636,7 +633,7 @@ static void quirk_intel_brickland_xeon_ras_cap(struct pci_dev *pdev)
pci_read_config_dword(pdev, 0x84, &capid0);
if (capid0 & 0x10)
- static_branch_inc(&mcsafe_key);
+ enable_copy_mc_fragile();
}
/* Skylake */
@@ -653,7 +650,7 @@ static void quirk_intel_purley_xeon_ras_cap(struct pci_dev *pdev)
* enabled, so memory machine check recovery is also enabled.
*/
if ((capid0 & 0xc0) == 0xc0 || (capid5 & 0x1e0))
- static_branch_inc(&mcsafe_key);
+ enable_copy_mc_fragile();
}
DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x0ec3, quirk_intel_brickland_xeon_ras_cap);
@@ -661,7 +658,6 @@ DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x2fc0, quirk_intel_brickland_xeon_
DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x6fc0, quirk_intel_brickland_xeon_ras_cap);
DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x2083, quirk_intel_purley_xeon_ras_cap);
#endif
-#endif
bool x86_apple_machine;
EXPORT_SYMBOL(x86_apple_machine);
diff --git a/arch/x86/lib/Makefile b/arch/x86/lib/Makefile
index d46fff11f06f..f7d23c9c22b2 100644
--- a/arch/x86/lib/Makefile
+++ b/arch/x86/lib/Makefile
@@ -44,6 +44,7 @@ obj-$(CONFIG_SMP) += msr-smp.o cache-smp.o
lib-y := delay.o misc.o cmdline.o cpu.o
lib-y += usercopy_$(BITS).o usercopy.o getuser.o putuser.o
lib-y += memcpy_$(BITS).o
+lib-$(CONFIG_ARCH_HAS_COPY_MC) += copy_mc.o copy_mc_64.o
lib-$(CONFIG_INSTRUCTION_DECODER) += insn.o inat.o insn-eval.o
lib-$(CONFIG_RANDOMIZE_BASE) += kaslr.o
lib-$(CONFIG_FUNCTION_ERROR_INJECTION) += error-inject.o
diff --git a/arch/x86/lib/copy_mc.c b/arch/x86/lib/copy_mc.c
new file mode 100644
index 000000000000..2633635530b7
--- /dev/null
+++ b/arch/x86/lib/copy_mc.c
@@ -0,0 +1,82 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright(c) 2016-2020 Intel Corporation. All rights reserved. */
+
+#include <linux/jump_label.h>
+#include <linux/uaccess.h>
+#include <linux/export.h>
+#include <linux/string.h>
+#include <linux/types.h>
+
+#include <asm/mce.h>
+
+#ifdef CONFIG_X86_MCE
+/*
+ * See COPY_MC_TEST for self-test of the copy_mc_fragile()
+ * implementation.
+ */
+static DEFINE_STATIC_KEY_FALSE(copy_mc_fragile_key);
+
+void enable_copy_mc_fragile(void)
+{
+ static_branch_inc(©_mc_fragile_key);
+}
+#define copy_mc_fragile_enabled (static_branch_unlikely(©_mc_fragile_key))
+
+/*
+ * Similar to copy_user_handle_tail, probe for the write fault point, or
+ * source exception point.
+ */
+__visible notrace unsigned long
+copy_mc_fragile_handle_tail(char *to, char *from, unsigned len)
+{
+ for (; len; --len, to++, from++)
+ if (copy_mc_fragile(to, from, 1))
+ break;
+ return len;
+}
+#else
+/*
+ * No point in doing careful copying, or consulting a static key when
+ * there is no #MC handler in the CONFIG_X86_MCE=n case.
+ */
+void enable_copy_mc_fragile(void)
+{
+}
+#define copy_mc_fragile_enabled (0)
+#endif
+
+/**
+ * copy_mc_to_kernel - memory copy that handles source exceptions
+ *
+ * @dst: destination address
+ * @src: source address
+ * @len: number of bytes to copy
+ *
+ * Call into the 'fragile' version on systems that have trouble
+ * actually do machine check recovery. Everyone else can just
+ * use memcpy().
+ *
+ * Return 0 for success, or number of bytes not copied if there was an
+ * exception.
+ */
+unsigned long __must_check copy_mc_to_kernel(void *dst, const void *src, unsigned len)
+{
+ if (copy_mc_fragile_enabled)
+ return copy_mc_fragile(dst, src, len);
+ memcpy(dst, src, len);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(copy_mc_to_kernel);
+
+unsigned long __must_check copy_mc_to_user(void *dst, const void *src, unsigned len)
+{
+ unsigned long ret;
+
+ if (!copy_mc_fragile_enabled)
+ return copy_user_generic(dst, src, len);
+
+ __uaccess_begin();
+ ret = copy_mc_fragile(dst, src, len);
+ __uaccess_end();
+ return ret;
+}
diff --git a/arch/x86/lib/copy_mc_64.S b/arch/x86/lib/copy_mc_64.S
new file mode 100644
index 000000000000..c3b613c4544a
--- /dev/null
+++ b/arch/x86/lib/copy_mc_64.S
@@ -0,0 +1,127 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* Copyright(c) 2016-2020 Intel Corporation. All rights reserved. */
+
+#include <linux/linkage.h>
+#include <asm/copy_mc_test.h>
+#include <asm/export.h>
+#include <asm/asm.h>
+
+#ifndef CONFIG_UML
+
+#ifdef CONFIG_X86_MCE
+COPY_MC_TEST_CTL
+
+/*
+ * copy_mc_fragile - copy memory with indication if an exception / fault happened
+ *
+ * The 'fragile' version is opted into by platform quirks and takes
+ * pains to avoid unrecoverable corner cases like 'fast-string'
+ * instruction sequences, and consuming poison across a cacheline
+ * boundary. The non-fragile version is equivalent to memcpy()
+ * regardless of CPU machine-check-recovery capability.
+ */
+SYM_FUNC_START(copy_mc_fragile)
+ cmpl $8, %edx
+ /* Less than 8 bytes? Go to byte copy loop */
+ jb .L_no_whole_words
+
+ /* Check for bad alignment of source */
+ testl $7, %esi
+ /* Already aligned */
+ jz .L_8byte_aligned
+
+ /* Copy one byte at a time until source is 8-byte aligned */
+ movl %esi, %ecx
+ andl $7, %ecx
+ subl $8, %ecx
+ negl %ecx
+ subl %ecx, %edx
+.L_read_leading_bytes:
+ movb (%rsi), %al
+ COPY_MC_TEST_SRC %rsi 1 .E_leading_bytes
+ COPY_MC_TEST_DST %rdi 1 .E_leading_bytes
+.L_write_leading_bytes:
+ movb %al, (%rdi)
+ incq %rsi
+ incq %rdi
+ decl %ecx
+ jnz .L_read_leading_bytes
+
+.L_8byte_aligned:
+ movl %edx, %ecx
+ andl $7, %edx
+ shrl $3, %ecx
+ jz .L_no_whole_words
+
+.L_read_words:
+ movq (%rsi), %r8
+ COPY_MC_TEST_SRC %rsi 8 .E_read_words
+ COPY_MC_TEST_DST %rdi 8 .E_write_words
+.L_write_words:
+ movq %r8, (%rdi)
+ addq $8, %rsi
+ addq $8, %rdi
+ decl %ecx
+ jnz .L_read_words
+
+ /* Any trailing bytes? */
+.L_no_whole_words:
+ andl %edx, %edx
+ jz .L_done_memcpy_trap
+
+ /* Copy trailing bytes */
+ movl %edx, %ecx
+.L_read_trailing_bytes:
+ movb (%rsi), %al
+ COPY_MC_TEST_SRC %rsi 1 .E_trailing_bytes
+ COPY_MC_TEST_DST %rdi 1 .E_trailing_bytes
+.L_write_trailing_bytes:
+ movb %al, (%rdi)
+ incq %rsi
+ incq %rdi
+ decl %ecx
+ jnz .L_read_trailing_bytes
+
+ /* Copy successful. Return zero */
+.L_done_memcpy_trap:
+ xorl %eax, %eax
+.L_done:
+ ret
+SYM_FUNC_END(copy_mc_fragile)
+EXPORT_SYMBOL_GPL(copy_mc_fragile)
+
+ .section .fixup, "ax"
+ /*
+ * Return number of bytes not copied for any failure. Note that
+ * there is no "tail" handling since the source buffer is 8-byte
+ * aligned and poison is cacheline aligned.
+ */
+.E_read_words:
+ shll $3, %ecx
+.E_leading_bytes:
+ addl %edx, %ecx
+.E_trailing_bytes:
+ mov %ecx, %eax
+ jmp .L_done
+
+ /*
+ * For write fault handling, given the destination is unaligned,
+ * we handle faults on multi-byte writes with a byte-by-byte
+ * copy up to the write-protected page.
+ */
+.E_write_words:
+ shll $3, %ecx
+ addl %edx, %ecx
+ movl %ecx, %edx
+ jmp copy_mc_fragile_handle_tail
+
+ .previous
+
+ _ASM_EXTABLE_FAULT(.L_read_leading_bytes, .E_leading_bytes)
+ _ASM_EXTABLE_FAULT(.L_read_words, .E_read_words)
+ _ASM_EXTABLE_FAULT(.L_read_trailing_bytes, .E_trailing_bytes)
+ _ASM_EXTABLE(.L_write_leading_bytes, .E_leading_bytes)
+ _ASM_EXTABLE(.L_write_words, .E_write_words)
+ _ASM_EXTABLE(.L_write_trailing_bytes, .E_trailing_bytes)
+#endif /* CONFIG_X86_MCE */
+#endif /* !CONFIG_UML */
diff --git a/arch/x86/lib/memcpy_64.S b/arch/x86/lib/memcpy_64.S
index bbcc05bcefad..037faac46b0c 100644
--- a/arch/x86/lib/memcpy_64.S
+++ b/arch/x86/lib/memcpy_64.S
@@ -4,7 +4,6 @@
#include <linux/linkage.h>
#include <asm/errno.h>
#include <asm/cpufeatures.h>
-#include <asm/mcsafe_test.h>
#include <asm/alternative-asm.h>
#include <asm/export.h>
@@ -187,117 +186,3 @@ SYM_FUNC_START_LOCAL(memcpy_orig)
SYM_FUNC_END(memcpy_orig)
.popsection
-
-#ifndef CONFIG_UML
-
-MCSAFE_TEST_CTL
-
-/*
- * __memcpy_mcsafe - memory copy with machine check exception handling
- * Note that we only catch machine checks when reading the source addresses.
- * Writes to target are posted and don't generate machine checks.
- */
-SYM_FUNC_START(__memcpy_mcsafe)
- cmpl $8, %edx
- /* Less than 8 bytes? Go to byte copy loop */
- jb .L_no_whole_words
-
- /* Check for bad alignment of source */
- testl $7, %esi
- /* Already aligned */
- jz .L_8byte_aligned
-
- /* Copy one byte at a time until source is 8-byte aligned */
- movl %esi, %ecx
- andl $7, %ecx
- subl $8, %ecx
- negl %ecx
- subl %ecx, %edx
-.L_read_leading_bytes:
- movb (%rsi), %al
- MCSAFE_TEST_SRC %rsi 1 .E_leading_bytes
- MCSAFE_TEST_DST %rdi 1 .E_leading_bytes
-.L_write_leading_bytes:
- movb %al, (%rdi)
- incq %rsi
- incq %rdi
- decl %ecx
- jnz .L_read_leading_bytes
-
-.L_8byte_aligned:
- movl %edx, %ecx
- andl $7, %edx
- shrl $3, %ecx
- jz .L_no_whole_words
-
-.L_read_words:
- movq (%rsi), %r8
- MCSAFE_TEST_SRC %rsi 8 .E_read_words
- MCSAFE_TEST_DST %rdi 8 .E_write_words
-.L_write_words:
- movq %r8, (%rdi)
- addq $8, %rsi
- addq $8, %rdi
- decl %ecx
- jnz .L_read_words
-
- /* Any trailing bytes? */
-.L_no_whole_words:
- andl %edx, %edx
- jz .L_done_memcpy_trap
-
- /* Copy trailing bytes */
- movl %edx, %ecx
-.L_read_trailing_bytes:
- movb (%rsi), %al
- MCSAFE_TEST_SRC %rsi 1 .E_trailing_bytes
- MCSAFE_TEST_DST %rdi 1 .E_trailing_bytes
-.L_write_trailing_bytes:
- movb %al, (%rdi)
- incq %rsi
- incq %rdi
- decl %ecx
- jnz .L_read_trailing_bytes
-
- /* Copy successful. Return zero */
-.L_done_memcpy_trap:
- xorl %eax, %eax
-.L_done:
- ret
-SYM_FUNC_END(__memcpy_mcsafe)
-EXPORT_SYMBOL_GPL(__memcpy_mcsafe)
-
- .section .fixup, "ax"
- /*
- * Return number of bytes not copied for any failure. Note that
- * there is no "tail" handling since the source buffer is 8-byte
- * aligned and poison is cacheline aligned.
- */
-.E_read_words:
- shll $3, %ecx
-.E_leading_bytes:
- addl %edx, %ecx
-.E_trailing_bytes:
- mov %ecx, %eax
- jmp .L_done
-
- /*
- * For write fault handling, given the destination is unaligned,
- * we handle faults on multi-byte writes with a byte-by-byte
- * copy up to the write-protected page.
- */
-.E_write_words:
- shll $3, %ecx
- addl %edx, %ecx
- movl %ecx, %edx
- jmp mcsafe_handle_tail
-
- .previous
-
- _ASM_EXTABLE_FAULT(.L_read_leading_bytes, .E_leading_bytes)
- _ASM_EXTABLE_FAULT(.L_read_words, .E_read_words)
- _ASM_EXTABLE_FAULT(.L_read_trailing_bytes, .E_trailing_bytes)
- _ASM_EXTABLE(.L_write_leading_bytes, .E_leading_bytes)
- _ASM_EXTABLE(.L_write_words, .E_write_words)
- _ASM_EXTABLE(.L_write_trailing_bytes, .E_trailing_bytes)
-#endif
diff --git a/arch/x86/lib/usercopy_64.c b/arch/x86/lib/usercopy_64.c
index b0dfac3d3df7..5f1d4a9ebd5a 100644
--- a/arch/x86/lib/usercopy_64.c
+++ b/arch/x86/lib/usercopy_64.c
@@ -56,27 +56,6 @@ unsigned long clear_user(void __user *to, unsigned long n)
}
EXPORT_SYMBOL(clear_user);
-/*
- * Similar to copy_user_handle_tail, probe for the write fault point,
- * but reuse __memcpy_mcsafe in case a new read error is encountered.
- * clac() is handled in _copy_to_iter_mcsafe().
- */
-__visible notrace unsigned long
-mcsafe_handle_tail(char *to, char *from, unsigned len)
-{
- for (; len; --len, to++, from++) {
- /*
- * Call the assembly routine back directly since
- * memcpy_mcsafe() may silently fallback to memcpy.
- */
- unsigned long rem = __memcpy_mcsafe(to, from, 1);
-
- if (rem)
- break;
- }
- return len;
-}
-
#ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE
/**
* clean_cache_range - write back a cache range with CLWB
diff --git a/drivers/md/dm-writecache.c b/drivers/md/dm-writecache.c
index 86dbe0c8b45c..9fc18fadacc6 100644
--- a/drivers/md/dm-writecache.c
+++ b/drivers/md/dm-writecache.c
@@ -49,7 +49,7 @@ do { \
#define pmem_assign(dest, src) ((dest) = (src))
#endif
-#if defined(__HAVE_ARCH_MEMCPY_MCSAFE) && defined(DM_WRITECACHE_HAS_PMEM)
+#if IS_ENABLED(CONFIG_ARCH_HAS_COPY_MC) && defined(DM_WRITECACHE_HAS_PMEM)
#define DM_WRITECACHE_HANDLE_HARDWARE_ERRORS
#endif
@@ -984,7 +984,8 @@ static void writecache_resume(struct dm_target *ti)
}
wc->freelist_size = 0;
- r = memcpy_mcsafe(&sb_seq_count, &sb(wc)->seq_count, sizeof(uint64_t));
+ r = copy_mc_to_kernel(&sb_seq_count, &sb(wc)->seq_count,
+ sizeof(uint64_t));
if (r) {
writecache_error(wc, r, "hardware memory error when reading superblock: %d", r);
sb_seq_count = cpu_to_le64(0);
@@ -1000,7 +1001,8 @@ static void writecache_resume(struct dm_target *ti)
e->seq_count = -1;
continue;
}
- r = memcpy_mcsafe(&wme, memory_entry(wc, e), sizeof(struct wc_memory_entry));
+ r = copy_mc_to_kernel(&wme, memory_entry(wc, e),
+ sizeof(struct wc_memory_entry));
if (r) {
writecache_error(wc, r, "hardware memory error when reading metadata entry %lu: %d",
(unsigned long)b, r);
@@ -1198,7 +1200,7 @@ static void bio_copy_block(struct dm_writecache *wc, struct bio *bio, void *data
if (rw == READ) {
int r;
- r = memcpy_mcsafe(buf, data, size);
+ r = copy_mc_to_kernel(buf, data, size);
flush_dcache_page(bio_page(bio));
if (unlikely(r)) {
writecache_error(wc, r, "hardware memory error when reading data: %d", r);
@@ -2341,7 +2343,7 @@ static int writecache_ctr(struct dm_target *ti, unsigned argc, char **argv)
}
}
- r = memcpy_mcsafe(&s, sb(wc), sizeof(struct wc_memory_superblock));
+ r = copy_mc_to_kernel(&s, sb(wc), sizeof(struct wc_memory_superblock));
if (r) {
ti->error = "Hardware memory error when reading superblock";
goto bad;
@@ -2352,7 +2354,8 @@ static int writecache_ctr(struct dm_target *ti, unsigned argc, char **argv)
ti->error = "Unable to initialize device";
goto bad;
}
- r = memcpy_mcsafe(&s, sb(wc), sizeof(struct wc_memory_superblock));
+ r = copy_mc_to_kernel(&s, sb(wc),
+ sizeof(struct wc_memory_superblock));
if (r) {
ti->error = "Hardware memory error when reading superblock";
goto bad;
diff --git a/drivers/nvdimm/claim.c b/drivers/nvdimm/claim.c
index 45964acba944..22d865ba6353 100644
--- a/drivers/nvdimm/claim.c
+++ b/drivers/nvdimm/claim.c
@@ -268,7 +268,7 @@ static int nsio_rw_bytes(struct nd_namespace_common *ndns,
if (rw == READ) {
if (unlikely(is_bad_pmem(&nsio->bb, sector, sz_align)))
return -EIO;
- if (memcpy_mcsafe(buf, nsio->addr + offset, size) != 0)
+ if (copy_mc_to_kernel(buf, nsio->addr + offset, size) != 0)
return -EIO;
return 0;
}
diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index fab29b514372..5c6939e004e2 100644
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c
@@ -125,7 +125,7 @@ static blk_status_t read_pmem(struct page *page, unsigned int off,
while (len) {
mem = kmap_atomic(page);
chunk = min_t(unsigned int, len, PAGE_SIZE - off);
- rem = memcpy_mcsafe(mem + off, pmem_addr, chunk);
+ rem = copy_mc_to_kernel(mem + off, pmem_addr, chunk);
kunmap_atomic(mem);
if (rem)
return BLK_STS_IOERR;
@@ -304,7 +304,7 @@ static long pmem_dax_direct_access(struct dax_device *dax_dev,
/*
* Use the 'no check' versions of copy_from_iter_flushcache() and
- * copy_to_iter_mcsafe() to bypass HARDENED_USERCOPY overhead. Bounds
+ * copy_mc_to_iter() to bypass HARDENED_USERCOPY overhead. Bounds
* checking, both file offset and device offset, is handled by
* dax_iomap_actor()
*/
@@ -317,7 +317,7 @@ static size_t pmem_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff,
static size_t pmem_copy_to_iter(struct dax_device *dax_dev, pgoff_t pgoff,
void *addr, size_t bytes, struct iov_iter *i)
{
- return _copy_to_iter_mcsafe(addr, bytes, i);
+ return _copy_mc_to_iter(addr, bytes, i);
}
static const struct dax_operations pmem_dax_ops = {
diff --git a/include/linux/string.h b/include/linux/string.h
index 9b7a0632e87a..b1f3894a0a3e 100644
--- a/include/linux/string.h
+++ b/include/linux/string.h
@@ -161,20 +161,13 @@ extern int bcmp(const void *,const void *,__kernel_size_t);
#ifndef __HAVE_ARCH_MEMCHR
extern void * memchr(const void *,int,__kernel_size_t);
#endif
-#ifndef __HAVE_ARCH_MEMCPY_MCSAFE
-static inline __must_check unsigned long memcpy_mcsafe(void *dst,
- const void *src, size_t cnt)
-{
- memcpy(dst, src, cnt);
- return 0;
-}
-#endif
#ifndef __HAVE_ARCH_MEMCPY_FLUSHCACHE
static inline void memcpy_flushcache(void *dst, const void *src, size_t cnt)
{
memcpy(dst, src, cnt);
}
#endif
+
void *memchr_inv(const void *s, int c, size_t n);
char *strreplace(char *s, char old, char new);
diff --git a/include/linux/uaccess.h b/include/linux/uaccess.h
index 94b285411659..1ae36bc8db35 100644
--- a/include/linux/uaccess.h
+++ b/include/linux/uaccess.h
@@ -179,6 +179,19 @@ copy_in_user(void __user *to, const void __user *from, unsigned long n)
}
#endif
+#ifndef copy_mc_to_kernel
+/*
+ * Without arch opt-in this generic copy_mc_to_kernel() will not handle
+ * #MC (or arch equivalent) during source read.
+ */
+static inline unsigned long __must_check
+copy_mc_to_kernel(void *dst, const void *src, size_t cnt)
+{
+ memcpy(dst, src, cnt);
+ return 0;
+}
+#endif
+
static __always_inline void pagefault_disabled_inc(void)
{
current->pagefault_disabled++;
diff --git a/include/linux/uio.h b/include/linux/uio.h
index 3835a8a8e9ea..f14410c678bd 100644
--- a/include/linux/uio.h
+++ b/include/linux/uio.h
@@ -185,10 +185,10 @@ size_t _copy_from_iter_flushcache(void *addr, size_t bytes, struct iov_iter *i);
#define _copy_from_iter_flushcache _copy_from_iter_nocache
#endif
-#ifdef CONFIG_ARCH_HAS_UACCESS_MCSAFE
-size_t _copy_to_iter_mcsafe(const void *addr, size_t bytes, struct iov_iter *i);
+#ifdef CONFIG_ARCH_HAS_COPY_MC
+size_t _copy_mc_to_iter(const void *addr, size_t bytes, struct iov_iter *i);
#else
-#define _copy_to_iter_mcsafe _copy_to_iter
+#define _copy_mc_to_iter _copy_to_iter
#endif
static __always_inline __must_check
@@ -201,12 +201,12 @@ size_t copy_from_iter_flushcache(void *addr, size_t bytes, struct iov_iter *i)
}
static __always_inline __must_check
-size_t copy_to_iter_mcsafe(void *addr, size_t bytes, struct iov_iter *i)
+size_t copy_mc_to_iter(void *addr, size_t bytes, struct iov_iter *i)
{
if (unlikely(!check_copy_size(addr, bytes, true)))
return 0;
else
- return _copy_to_iter_mcsafe(addr, bytes, i);
+ return _copy_mc_to_iter(addr, bytes, i);
}
size_t iov_iter_zero(size_t bytes, struct iov_iter *);
diff --git a/lib/Kconfig b/lib/Kconfig
index b4b98a03ff98..b46a9fd122c8 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -635,7 +635,12 @@ config UACCESS_MEMCPY
config ARCH_HAS_UACCESS_FLUSHCACHE
bool
-config ARCH_HAS_UACCESS_MCSAFE
+# arch has a concept of a recoverable synchronous exception due to a
+# memory-read error like x86 machine-check or ARM data-abort, and
+# implements copy_mc_to_{user,kernel} to abort and report
+# 'bytes-transferred' if that exception fires when accessing the source
+# buffer.
+config ARCH_HAS_COPY_MC
bool
# Temporary. Goes away when all archs are cleaned up
diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index 5e40786c8f12..d13304a034f5 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -637,30 +637,30 @@ size_t _copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i)
}
EXPORT_SYMBOL(_copy_to_iter);
-#ifdef CONFIG_ARCH_HAS_UACCESS_MCSAFE
-static int copyout_mcsafe(void __user *to, const void *from, size_t n)
+#ifdef CONFIG_ARCH_HAS_COPY_MC
+static int copyout_mc(void __user *to, const void *from, size_t n)
{
if (access_ok(to, n)) {
instrument_copy_to_user(to, from, n);
- n = copy_to_user_mcsafe((__force void *) to, from, n);
+ n = copy_mc_to_user((__force void *) to, from, n);
}
return n;
}
-static unsigned long memcpy_mcsafe_to_page(struct page *page, size_t offset,
+static unsigned long copy_mc_to_page(struct page *page, size_t offset,
const char *from, size_t len)
{
unsigned long ret;
char *to;
to = kmap_atomic(page);
- ret = memcpy_mcsafe(to + offset, from, len);
+ ret = copy_mc_to_kernel(to + offset, from, len);
kunmap_atomic(to);
return ret;
}
-static size_t copy_pipe_to_iter_mcsafe(const void *addr, size_t bytes,
+static size_t copy_mc_pipe_to_iter(const void *addr, size_t bytes,
struct iov_iter *i)
{
struct pipe_inode_info *pipe = i->pipe;
@@ -678,7 +678,7 @@ static size_t copy_pipe_to_iter_mcsafe(const void *addr, size_t bytes,
size_t chunk = min_t(size_t, n, PAGE_SIZE - off);
unsigned long rem;
- rem = memcpy_mcsafe_to_page(pipe->bufs[i_head & p_mask].page,
+ rem = copy_mc_to_page(pipe->bufs[i_head & p_mask].page,
off, addr, chunk);
i->head = i_head;
i->iov_offset = off + chunk - rem;
@@ -695,18 +695,17 @@ static size_t copy_pipe_to_iter_mcsafe(const void *addr, size_t bytes,
}
/**
- * _copy_to_iter_mcsafe - copy to user with source-read error exception handling
+ * _copy_mc_to_iter - copy to iter with source memory error exception handling
* @addr: source kernel address
* @bytes: total transfer length
* @iter: destination iterator
*
- * The pmem driver arranges for filesystem-dax to use this facility via
- * dax_copy_to_iter() for protecting read/write to persistent memory.
- * Unless / until an architecture can guarantee identical performance
- * between _copy_to_iter_mcsafe() and _copy_to_iter() it would be a
- * performance regression to switch more users to the mcsafe version.
+ * The pmem driver deploys this for the dax operation
+ * (dax_copy_to_iter()) for dax reads (bypass page-cache and the
+ * block-layer). Upon #MC read(2) aborts and returns EIO or the bytes
+ * successfully copied.
*
- * Otherwise, the main differences between this and typical _copy_to_iter().
+ * The main differences between this and typical _copy_to_iter().
*
* * Typical tail/residue handling after a fault retries the copy
* byte-by-byte until the fault happens again. Re-triggering machine
@@ -717,23 +716,22 @@ static size_t copy_pipe_to_iter_mcsafe(const void *addr, size_t bytes,
* * ITER_KVEC, ITER_PIPE, and ITER_BVEC can return short copies.
* Compare to copy_to_iter() where only ITER_IOVEC attempts might return
* a short copy.
- *
- * See MCSAFE_TEST for self-test.
*/
-size_t _copy_to_iter_mcsafe(const void *addr, size_t bytes, struct iov_iter *i)
+size_t _copy_mc_to_iter(const void *addr, size_t bytes, struct iov_iter *i)
{
const char *from = addr;
unsigned long rem, curr_addr, s_addr = (unsigned long) addr;
if (unlikely(iov_iter_is_pipe(i)))
- return copy_pipe_to_iter_mcsafe(addr, bytes, i);
+ return copy_mc_pipe_to_iter(addr, bytes, i);
if (iter_is_iovec(i))
might_fault();
iterate_and_advance(i, bytes, v,
- copyout_mcsafe(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len),
+ copyout_mc(v.iov_base, (from += v.iov_len) - v.iov_len,
+ v.iov_len),
({
- rem = memcpy_mcsafe_to_page(v.bv_page, v.bv_offset,
- (from += v.bv_len) - v.bv_len, v.bv_len);
+ rem = copy_mc_to_page(v.bv_page, v.bv_offset,
+ (from += v.bv_len) - v.bv_len, v.bv_len);
if (rem) {
curr_addr = (unsigned long) from;
bytes = curr_addr - s_addr - rem;
@@ -741,8 +739,8 @@ size_t _copy_to_iter_mcsafe(const void *addr, size_t bytes, struct iov_iter *i)
}
}),
({
- rem = memcpy_mcsafe(v.iov_base, (from += v.iov_len) - v.iov_len,
- v.iov_len);
+ rem = copy_mc_to_kernel(v.iov_base, (from += v.iov_len)
+ - v.iov_len, v.iov_len);
if (rem) {
curr_addr = (unsigned long) from;
bytes = curr_addr - s_addr - rem;
@@ -753,8 +751,8 @@ size_t _copy_to_iter_mcsafe(const void *addr, size_t bytes, struct iov_iter *i)
return bytes;
}
-EXPORT_SYMBOL_GPL(_copy_to_iter_mcsafe);
-#endif /* CONFIG_ARCH_HAS_UACCESS_MCSAFE */
+EXPORT_SYMBOL_GPL(_copy_mc_to_iter);
+#endif /* CONFIG_ARCH_HAS_COPY_MC */
size_t _copy_from_iter(void *addr, size_t bytes, struct iov_iter *i)
{
diff --git a/tools/arch/x86/include/asm/mcsafe_test.h b/tools/arch/x86/include/asm/mcsafe_test.h
deleted file mode 100644
index 2ccd588fbad4..000000000000
--- a/tools/arch/x86/include/asm/mcsafe_test.h
+++ /dev/null
@@ -1,13 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef _MCSAFE_TEST_H_
-#define _MCSAFE_TEST_H_
-
-.macro MCSAFE_TEST_CTL
-.endm
-
-.macro MCSAFE_TEST_SRC reg count target
-.endm
-
-.macro MCSAFE_TEST_DST reg count target
-.endm
-#endif /* _MCSAFE_TEST_H_ */
diff --git a/tools/arch/x86/lib/memcpy_64.S b/tools/arch/x86/lib/memcpy_64.S
index 45f8e1b02241..0b5b8ae56bd9 100644
--- a/tools/arch/x86/lib/memcpy_64.S
+++ b/tools/arch/x86/lib/memcpy_64.S
@@ -4,7 +4,6 @@
#include <linux/linkage.h>
#include <asm/errno.h>
#include <asm/cpufeatures.h>
-#include <asm/mcsafe_test.h>
#include <asm/alternative-asm.h>
#include <asm/export.h>
@@ -187,117 +186,3 @@ SYM_FUNC_START(memcpy_orig)
SYM_FUNC_END(memcpy_orig)
.popsection
-
-#ifndef CONFIG_UML
-
-MCSAFE_TEST_CTL
-
-/*
- * __memcpy_mcsafe - memory copy with machine check exception handling
- * Note that we only catch machine checks when reading the source addresses.
- * Writes to target are posted and don't generate machine checks.
- */
-SYM_FUNC_START(__memcpy_mcsafe)
- cmpl $8, %edx
- /* Less than 8 bytes? Go to byte copy loop */
- jb .L_no_whole_words
-
- /* Check for bad alignment of source */
- testl $7, %esi
- /* Already aligned */
- jz .L_8byte_aligned
-
- /* Copy one byte at a time until source is 8-byte aligned */
- movl %esi, %ecx
- andl $7, %ecx
- subl $8, %ecx
- negl %ecx
- subl %ecx, %edx
-.L_read_leading_bytes:
- movb (%rsi), %al
- MCSAFE_TEST_SRC %rsi 1 .E_leading_bytes
- MCSAFE_TEST_DST %rdi 1 .E_leading_bytes
-.L_write_leading_bytes:
- movb %al, (%rdi)
- incq %rsi
- incq %rdi
- decl %ecx
- jnz .L_read_leading_bytes
-
-.L_8byte_aligned:
- movl %edx, %ecx
- andl $7, %edx
- shrl $3, %ecx
- jz .L_no_whole_words
-
-.L_read_words:
- movq (%rsi), %r8
- MCSAFE_TEST_SRC %rsi 8 .E_read_words
- MCSAFE_TEST_DST %rdi 8 .E_write_words
-.L_write_words:
- movq %r8, (%rdi)
- addq $8, %rsi
- addq $8, %rdi
- decl %ecx
- jnz .L_read_words
-
- /* Any trailing bytes? */
-.L_no_whole_words:
- andl %edx, %edx
- jz .L_done_memcpy_trap
-
- /* Copy trailing bytes */
- movl %edx, %ecx
-.L_read_trailing_bytes:
- movb (%rsi), %al
- MCSAFE_TEST_SRC %rsi 1 .E_trailing_bytes
- MCSAFE_TEST_DST %rdi 1 .E_trailing_bytes
-.L_write_trailing_bytes:
- movb %al, (%rdi)
- incq %rsi
- incq %rdi
- decl %ecx
- jnz .L_read_trailing_bytes
-
- /* Copy successful. Return zero */
-.L_done_memcpy_trap:
- xorl %eax, %eax
-.L_done:
- ret
-SYM_FUNC_END(__memcpy_mcsafe)
-EXPORT_SYMBOL_GPL(__memcpy_mcsafe)
-
- .section .fixup, "ax"
- /*
- * Return number of bytes not copied for any failure. Note that
- * there is no "tail" handling since the source buffer is 8-byte
- * aligned and poison is cacheline aligned.
- */
-.E_read_words:
- shll $3, %ecx
-.E_leading_bytes:
- addl %edx, %ecx
-.E_trailing_bytes:
- mov %ecx, %eax
- jmp .L_done
-
- /*
- * For write fault handling, given the destination is unaligned,
- * we handle faults on multi-byte writes with a byte-by-byte
- * copy up to the write-protected page.
- */
-.E_write_words:
- shll $3, %ecx
- addl %edx, %ecx
- movl %ecx, %edx
- jmp mcsafe_handle_tail
-
- .previous
-
- _ASM_EXTABLE_FAULT(.L_read_leading_bytes, .E_leading_bytes)
- _ASM_EXTABLE_FAULT(.L_read_words, .E_read_words)
- _ASM_EXTABLE_FAULT(.L_read_trailing_bytes, .E_trailing_bytes)
- _ASM_EXTABLE(.L_write_leading_bytes, .E_leading_bytes)
- _ASM_EXTABLE(.L_write_words, .E_write_words)
- _ASM_EXTABLE(.L_write_trailing_bytes, .E_trailing_bytes)
-#endif
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index e034a8f24f46..893f021fec63 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -548,8 +548,8 @@ static const char *uaccess_safe_builtin[] = {
"__ubsan_handle_shift_out_of_bounds",
/* misc */
"csum_partial_copy_generic",
- "__memcpy_mcsafe",
- "mcsafe_handle_tail",
+ "copy_mc_fragile",
+ "copy_mc_fragile_handle_tail",
"ftrace_likely_update", /* CONFIG_TRACE_BRANCH_PROFILING */
NULL
};
diff --git a/tools/perf/bench/Build b/tools/perf/bench/Build
index dd68a40a790c..878db6a59a41 100644
--- a/tools/perf/bench/Build
+++ b/tools/perf/bench/Build
@@ -13,7 +13,6 @@ perf-y += synthesize.o
perf-y += kallsyms-parse.o
perf-y += find-bit-bench.o
-perf-$(CONFIG_X86_64) += mem-memcpy-x86-64-lib.o
perf-$(CONFIG_X86_64) += mem-memcpy-x86-64-asm.o
perf-$(CONFIG_X86_64) += mem-memset-x86-64-asm.o
diff --git a/tools/perf/bench/mem-memcpy-x86-64-lib.c b/tools/perf/bench/mem-memcpy-x86-64-lib.c
deleted file mode 100644
index 4130734dde84..000000000000
--- a/tools/perf/bench/mem-memcpy-x86-64-lib.c
+++ /dev/null
@@ -1,24 +0,0 @@
-/*
- * From code in arch/x86/lib/usercopy_64.c, copied to keep tools/ copy
- * of the kernel's arch/x86/lib/memcpy_64.s used in 'perf bench mem memcpy'
- * happy.
- */
-#include <linux/types.h>
-
-unsigned long __memcpy_mcsafe(void *dst, const void *src, size_t cnt);
-unsigned long mcsafe_handle_tail(char *to, char *from, unsigned len);
-
-unsigned long mcsafe_handle_tail(char *to, char *from, unsigned len)
-{
- for (; len; --len, to++, from++) {
- /*
- * Call the assembly routine back directly since
- * memcpy_mcsafe() may silently fallback to memcpy.
- */
- unsigned long rem = __memcpy_mcsafe(to, from, 1);
-
- if (rem)
- break;
- }
- return len;
-}
diff --git a/tools/testing/nvdimm/test/nfit.c b/tools/testing/nvdimm/test/nfit.c
index a1a5dc645b40..2ac0fff6dad8 100644
--- a/tools/testing/nvdimm/test/nfit.c
+++ b/tools/testing/nvdimm/test/nfit.c
@@ -23,7 +23,8 @@
#include "nfit_test.h"
#include "../watermark.h"
-#include <asm/mcsafe_test.h>
+#include <asm/copy_mc_test.h>
+#include <asm/mce.h>
/*
* Generate an NFIT table to describe the following topology:
@@ -3283,7 +3284,7 @@ static struct platform_driver nfit_test_driver = {
.id_table = nfit_test_id,
};
-static char mcsafe_buf[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE)));
+static char copy_mc_buf[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE)));
enum INJECT {
INJECT_NONE,
@@ -3291,7 +3292,7 @@ enum INJECT {
INJECT_DST,
};
-static void mcsafe_test_init(char *dst, char *src, size_t size)
+static void copy_mc_test_init(char *dst, char *src, size_t size)
{
size_t i;
@@ -3300,7 +3301,7 @@ static void mcsafe_test_init(char *dst, char *src, size_t size)
src[i] = (char) i;
}
-static bool mcsafe_test_validate(unsigned char *dst, unsigned char *src,
+static bool copy_mc_test_validate(unsigned char *dst, unsigned char *src,
size_t size, unsigned long rem)
{
size_t i;
@@ -3321,12 +3322,12 @@ static bool mcsafe_test_validate(unsigned char *dst, unsigned char *src,
return true;
}
-void mcsafe_test(void)
+void copy_mc_test(void)
{
char *inject_desc[] = { "none", "source", "destination" };
enum INJECT inj;
- if (IS_ENABLED(CONFIG_MCSAFE_TEST)) {
+ if (IS_ENABLED(CONFIG_COPY_MC_TEST)) {
pr_info("%s: run...\n", __func__);
} else {
pr_info("%s: disabled, skip.\n", __func__);
@@ -3344,31 +3345,31 @@ void mcsafe_test(void)
switch (inj) {
case INJECT_NONE:
- mcsafe_inject_src(NULL);
- mcsafe_inject_dst(NULL);
- dst = &mcsafe_buf[2048];
- src = &mcsafe_buf[1024 - i];
+ copy_mc_inject_src(NULL);
+ copy_mc_inject_dst(NULL);
+ dst = ©_mc_buf[2048];
+ src = ©_mc_buf[1024 - i];
expect = 0;
break;
case INJECT_SRC:
- mcsafe_inject_src(&mcsafe_buf[1024]);
- mcsafe_inject_dst(NULL);
- dst = &mcsafe_buf[2048];
- src = &mcsafe_buf[1024 - i];
+ copy_mc_inject_src(©_mc_buf[1024]);
+ copy_mc_inject_dst(NULL);
+ dst = ©_mc_buf[2048];
+ src = ©_mc_buf[1024 - i];
expect = 512 - i;
break;
case INJECT_DST:
- mcsafe_inject_src(NULL);
- mcsafe_inject_dst(&mcsafe_buf[2048]);
- dst = &mcsafe_buf[2048 - i];
- src = &mcsafe_buf[1024];
+ copy_mc_inject_src(NULL);
+ copy_mc_inject_dst(©_mc_buf[2048]);
+ dst = ©_mc_buf[2048 - i];
+ src = ©_mc_buf[1024];
expect = 512 - i;
break;
}
- mcsafe_test_init(dst, src, 512);
- rem = __memcpy_mcsafe(dst, src, 512);
- valid = mcsafe_test_validate(dst, src, 512, expect);
+ copy_mc_test_init(dst, src, 512);
+ rem = copy_mc_fragile(dst, src, 512);
+ valid = copy_mc_test_validate(dst, src, 512, expect);
if (rem == expect && valid)
continue;
pr_info("%s: copy(%#lx, %#lx, %d) off: %d rem: %ld %s expect: %ld\n",
@@ -3380,8 +3381,8 @@ void mcsafe_test(void)
}
}
- mcsafe_inject_src(NULL);
- mcsafe_inject_dst(NULL);
+ copy_mc_inject_src(NULL);
+ copy_mc_inject_dst(NULL);
}
static __init int nfit_test_init(void)
@@ -3392,7 +3393,7 @@ static __init int nfit_test_init(void)
libnvdimm_test();
acpi_nfit_test();
device_dax_test();
- mcsafe_test();
+ copy_mc_test();
dax_pmem_test();
dax_pmem_core_test();
#ifdef CONFIG_DEV_DAX_PMEM_COMPAT
diff --git a/tools/testing/selftests/powerpc/copyloops/.gitignore b/tools/testing/selftests/powerpc/copyloops/.gitignore
index ddaf140b8255..994b11af765c 100644
--- a/tools/testing/selftests/powerpc/copyloops/.gitignore
+++ b/tools/testing/selftests/powerpc/copyloops/.gitignore
@@ -12,4 +12,4 @@ memcpy_p7_t1
copyuser_64_exc_t0
copyuser_64_exc_t1
copyuser_64_exc_t2
-memcpy_mcsafe_64
+copy_mc_64
diff --git a/tools/testing/selftests/powerpc/copyloops/Makefile b/tools/testing/selftests/powerpc/copyloops/Makefile
index 0917983a1c78..3095b1f1c02b 100644
--- a/tools/testing/selftests/powerpc/copyloops/Makefile
+++ b/tools/testing/selftests/powerpc/copyloops/Makefile
@@ -12,7 +12,7 @@ ASFLAGS = $(CFLAGS) -Wa,-mpower4
TEST_GEN_PROGS := copyuser_64_t0 copyuser_64_t1 copyuser_64_t2 \
copyuser_p7_t0 copyuser_p7_t1 \
memcpy_64_t0 memcpy_64_t1 memcpy_64_t2 \
- memcpy_p7_t0 memcpy_p7_t1 memcpy_mcsafe_64 \
+ memcpy_p7_t0 memcpy_p7_t1 copy_mc_64 \
copyuser_64_exc_t0 copyuser_64_exc_t1 copyuser_64_exc_t2
EXTRA_SOURCES := validate.c ../harness.c stubs.S
@@ -45,9 +45,9 @@ $(OUTPUT)/memcpy_p7_t%: memcpy_power7.S $(EXTRA_SOURCES)
-D SELFTEST_CASE=$(subst memcpy_p7_t,,$(notdir $@)) \
-o $@ $^
-$(OUTPUT)/memcpy_mcsafe_64: memcpy_mcsafe_64.S $(EXTRA_SOURCES)
+$(OUTPUT)/copy_mc_64: copy_mc_64.S $(EXTRA_SOURCES)
$(CC) $(CPPFLAGS) $(CFLAGS) \
- -D COPY_LOOP=test_memcpy_mcsafe \
+ -D COPY_LOOP=test_copy_mc_generic \
-o $@ $^
$(OUTPUT)/copyuser_64_exc_t%: copyuser_64.S exc_validate.c ../harness.c \
diff --git a/tools/testing/selftests/powerpc/copyloops/copy_mc_64.S b/tools/testing/selftests/powerpc/copyloops/copy_mc_64.S
new file mode 120000
index 000000000000..dcbe06d500fb
--- /dev/null
+++ b/tools/testing/selftests/powerpc/copyloops/copy_mc_64.S
@@ -0,0 +1 @@
+../../../../../arch/powerpc/lib/copy_mc_64.S
\ No newline at end of file
diff --git a/tools/testing/selftests/powerpc/copyloops/memcpy_mcsafe_64.S b/tools/testing/selftests/powerpc/copyloops/memcpy_mcsafe_64.S
deleted file mode 120000
index f0feef3062f6..000000000000
--- a/tools/testing/selftests/powerpc/copyloops/memcpy_mcsafe_64.S
+++ /dev/null
@@ -1 +0,0 @@
-../../../../../arch/powerpc/lib/memcpy_mcsafe_64.S
\ No newline at end of file
4 years, 3 months
- 1
- 0
FAILED: patch "[PATCH] x86, powerpc: Rename memcpy_mcsafe() to copy_mc_to_{user, " failed to apply to 4.14-stable tree
by gregkh＠linuxfoundation.org
The patch below does not apply to the 4.14-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From ec6347bb43395cb92126788a1a5b25302543f815 Mon Sep 17 00:00:00 2001
From: Dan Williams <dan.j.williams(a)intel.com>
Date: Mon, 5 Oct 2020 20:40:16 -0700
Subject: [PATCH] x86, powerpc: Rename memcpy_mcsafe() to copy_mc_to_{user,
kernel}()
In reaction to a proposal to introduce a memcpy_mcsafe_fast()
implementation Linus points out that memcpy_mcsafe() is poorly named
relative to communicating the scope of the interface. Specifically what
addresses are valid to pass as source, destination, and what faults /
exceptions are handled.
Of particular concern is that even though x86 might be able to handle
the semantics of copy_mc_to_user() with its common copy_user_generic()
implementation other archs likely need / want an explicit path for this
case:
On Fri, May 1, 2020 at 11:28 AM Linus Torvalds <torvalds(a)linux-foundation.org> wrote:
>
> On Thu, Apr 30, 2020 at 6:21 PM Dan Williams <dan.j.williams(a)intel.com> wrote:
> >
> > However now I see that copy_user_generic() works for the wrong reason.
> > It works because the exception on the source address due to poison
> > looks no different than a write fault on the user address to the
> > caller, it's still just a short copy. So it makes copy_to_user() work
> > for the wrong reason relative to the name.
>
> Right.
>
> And it won't work that way on other architectures. On x86, we have a
> generic function that can take faults on either side, and we use it
> for both cases (and for the "in_user" case too), but that's an
> artifact of the architecture oddity.
>
> In fact, it's probably wrong even on x86 - because it can hide bugs -
> but writing those things is painful enough that everybody prefers
> having just one function.
Replace a single top-level memcpy_mcsafe() with either
copy_mc_to_user(), or copy_mc_to_kernel().
Introduce an x86 copy_mc_fragile() name as the rename for the
low-level x86 implementation formerly named memcpy_mcsafe(). It is used
as the slow / careful backend that is supplanted by a fast
copy_mc_generic() in a follow-on patch.
One side-effect of this reorganization is that separating copy_mc_64.S
to its own file means that perf no longer needs to track dependencies
for its memcpy_64.S benchmarks.
[ bp: Massage a bit. ]
Signed-off-by: Dan Williams <dan.j.williams(a)intel.com>
Signed-off-by: Borislav Petkov <bp(a)suse.de>
Reviewed-by: Tony Luck <tony.luck(a)intel.com>
Acked-by: Michael Ellerman <mpe(a)ellerman.id.au>
Cc: <stable(a)vger.kernel.org>
Link: http://lore.kernel.org/r/CAHk-=wjSqtXAqfUJxFtWNwmguFASTgB0dz1dT3V-78Quiezqb…
Link: https://lkml.kernel.org/r/160195561680.2163339.11574962055305783722.stgit@d…
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 1f48bbfb3ce9..76473eda3426 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -136,7 +136,7 @@ config PPC
select ARCH_HAS_STRICT_KERNEL_RWX if (PPC32 && !HIBERNATION)
select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
select ARCH_HAS_UACCESS_FLUSHCACHE
- select ARCH_HAS_UACCESS_MCSAFE if PPC64
+ select ARCH_HAS_COPY_MC if PPC64
select ARCH_HAS_UBSAN_SANITIZE_ALL
select ARCH_HAVE_NMI_SAFE_CMPXCHG
select ARCH_KEEP_MEMBLOCK
diff --git a/arch/powerpc/include/asm/string.h b/arch/powerpc/include/asm/string.h
index 283552cd0e58..2aa0e31e6884 100644
--- a/arch/powerpc/include/asm/string.h
+++ b/arch/powerpc/include/asm/string.h
@@ -53,9 +53,7 @@ void *__memmove(void *to, const void *from, __kernel_size_t n);
#ifndef CONFIG_KASAN
#define __HAVE_ARCH_MEMSET32
#define __HAVE_ARCH_MEMSET64
-#define __HAVE_ARCH_MEMCPY_MCSAFE
-extern int memcpy_mcsafe(void *dst, const void *src, __kernel_size_t sz);
extern void *__memset16(uint16_t *, uint16_t v, __kernel_size_t);
extern void *__memset32(uint32_t *, uint32_t v, __kernel_size_t);
extern void *__memset64(uint64_t *, uint64_t v, __kernel_size_t);
diff --git a/arch/powerpc/include/asm/uaccess.h b/arch/powerpc/include/asm/uaccess.h
index 00699903f1ef..20a35373cafc 100644
--- a/arch/powerpc/include/asm/uaccess.h
+++ b/arch/powerpc/include/asm/uaccess.h
@@ -435,6 +435,32 @@ do { \
extern unsigned long __copy_tofrom_user(void __user *to,
const void __user *from, unsigned long size);
+#ifdef CONFIG_ARCH_HAS_COPY_MC
+unsigned long __must_check
+copy_mc_generic(void *to, const void *from, unsigned long size);
+
+static inline unsigned long __must_check
+copy_mc_to_kernel(void *to, const void *from, unsigned long size)
+{
+ return copy_mc_generic(to, from, size);
+}
+#define copy_mc_to_kernel copy_mc_to_kernel
+
+static inline unsigned long __must_check
+copy_mc_to_user(void __user *to, const void *from, unsigned long n)
+{
+ if (likely(check_copy_size(from, n, true))) {
+ if (access_ok(to, n)) {
+ allow_write_to_user(to, n);
+ n = copy_mc_generic((void *)to, from, n);
+ prevent_write_to_user(to, n);
+ }
+ }
+
+ return n;
+}
+#endif
+
#ifdef __powerpc64__
static inline unsigned long
raw_copy_in_user(void __user *to, const void __user *from, unsigned long n)
@@ -523,20 +549,6 @@ raw_copy_to_user(void __user *to, const void *from, unsigned long n)
return ret;
}
-static __always_inline unsigned long __must_check
-copy_to_user_mcsafe(void __user *to, const void *from, unsigned long n)
-{
- if (likely(check_copy_size(from, n, true))) {
- if (access_ok(to, n)) {
- allow_write_to_user(to, n);
- n = memcpy_mcsafe((void *)to, from, n);
- prevent_write_to_user(to, n);
- }
- }
-
- return n;
-}
-
unsigned long __arch_clear_user(void __user *addr, unsigned long size);
static inline unsigned long clear_user(void __user *addr, unsigned long size)
diff --git a/arch/powerpc/lib/Makefile b/arch/powerpc/lib/Makefile
index d66a645503eb..69a91b571845 100644
--- a/arch/powerpc/lib/Makefile
+++ b/arch/powerpc/lib/Makefile
@@ -39,7 +39,7 @@ obj-$(CONFIG_PPC_BOOK3S_64) += copyuser_power7.o copypage_power7.o \
memcpy_power7.o
obj64-y += copypage_64.o copyuser_64.o mem_64.o hweight_64.o \
- memcpy_64.o memcpy_mcsafe_64.o
+ memcpy_64.o copy_mc_64.o
ifndef CONFIG_PPC_QUEUED_SPINLOCKS
obj64-$(CONFIG_SMP) += locks.o
diff --git a/arch/powerpc/lib/memcpy_mcsafe_64.S b/arch/powerpc/lib/copy_mc_64.S
similarity index 98%
rename from arch/powerpc/lib/memcpy_mcsafe_64.S
rename to arch/powerpc/lib/copy_mc_64.S
index cb882d9a6d8a..88d46c471493 100644
--- a/arch/powerpc/lib/memcpy_mcsafe_64.S
+++ b/arch/powerpc/lib/copy_mc_64.S
@@ -50,7 +50,7 @@ err3; stb r0,0(r3)
blr
-_GLOBAL(memcpy_mcsafe)
+_GLOBAL(copy_mc_generic)
mr r7,r5
cmpldi r5,16
blt .Lshort_copy
@@ -239,4 +239,4 @@ err1; stb r0,0(r3)
15: li r3,0
blr
-EXPORT_SYMBOL_GPL(memcpy_mcsafe);
+EXPORT_SYMBOL_GPL(copy_mc_generic);
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 7101ac64bb20..e876b3a087f9 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -75,7 +75,7 @@ config X86
select ARCH_HAS_PTE_DEVMAP if X86_64
select ARCH_HAS_PTE_SPECIAL
select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64
- select ARCH_HAS_UACCESS_MCSAFE if X86_64 && X86_MCE
+ select ARCH_HAS_COPY_MC if X86_64
select ARCH_HAS_SET_MEMORY
select ARCH_HAS_SET_DIRECT_MAP
select ARCH_HAS_STRICT_KERNEL_RWX
diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug
index ee1d3c5834c6..27b5e2bc6a01 100644
--- a/arch/x86/Kconfig.debug
+++ b/arch/x86/Kconfig.debug
@@ -62,7 +62,7 @@ config EARLY_PRINTK_USB_XDBC
You should normally say N here, unless you want to debug early
crashes or need a very simple printk logging facility.
-config MCSAFE_TEST
+config COPY_MC_TEST
def_bool n
config EFI_PGT_DUMP
diff --git a/arch/x86/include/asm/copy_mc_test.h b/arch/x86/include/asm/copy_mc_test.h
new file mode 100644
index 000000000000..e4991ba96726
--- /dev/null
+++ b/arch/x86/include/asm/copy_mc_test.h
@@ -0,0 +1,75 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _COPY_MC_TEST_H_
+#define _COPY_MC_TEST_H_
+
+#ifndef __ASSEMBLY__
+#ifdef CONFIG_COPY_MC_TEST
+extern unsigned long copy_mc_test_src;
+extern unsigned long copy_mc_test_dst;
+
+static inline void copy_mc_inject_src(void *addr)
+{
+ if (addr)
+ copy_mc_test_src = (unsigned long) addr;
+ else
+ copy_mc_test_src = ~0UL;
+}
+
+static inline void copy_mc_inject_dst(void *addr)
+{
+ if (addr)
+ copy_mc_test_dst = (unsigned long) addr;
+ else
+ copy_mc_test_dst = ~0UL;
+}
+#else /* CONFIG_COPY_MC_TEST */
+static inline void copy_mc_inject_src(void *addr)
+{
+}
+
+static inline void copy_mc_inject_dst(void *addr)
+{
+}
+#endif /* CONFIG_COPY_MC_TEST */
+
+#else /* __ASSEMBLY__ */
+#include <asm/export.h>
+
+#ifdef CONFIG_COPY_MC_TEST
+.macro COPY_MC_TEST_CTL
+ .pushsection .data
+ .align 8
+ .globl copy_mc_test_src
+ copy_mc_test_src:
+ .quad 0
+ EXPORT_SYMBOL_GPL(copy_mc_test_src)
+ .globl copy_mc_test_dst
+ copy_mc_test_dst:
+ .quad 0
+ EXPORT_SYMBOL_GPL(copy_mc_test_dst)
+ .popsection
+.endm
+
+.macro COPY_MC_TEST_SRC reg count target
+ leaq \count(\reg), %r9
+ cmp copy_mc_test_src, %r9
+ ja \target
+.endm
+
+.macro COPY_MC_TEST_DST reg count target
+ leaq \count(\reg), %r9
+ cmp copy_mc_test_dst, %r9
+ ja \target
+.endm
+#else
+.macro COPY_MC_TEST_CTL
+.endm
+
+.macro COPY_MC_TEST_SRC reg count target
+.endm
+
+.macro COPY_MC_TEST_DST reg count target
+.endm
+#endif /* CONFIG_COPY_MC_TEST */
+#endif /* __ASSEMBLY__ */
+#endif /* _COPY_MC_TEST_H_ */
diff --git a/arch/x86/include/asm/mce.h b/arch/x86/include/asm/mce.h
index 109af5c7f515..ba2062d6df92 100644
--- a/arch/x86/include/asm/mce.h
+++ b/arch/x86/include/asm/mce.h
@@ -174,6 +174,15 @@ extern void mce_unregister_decode_chain(struct notifier_block *nb);
extern int mce_p5_enabled;
+#ifdef CONFIG_ARCH_HAS_COPY_MC
+extern void enable_copy_mc_fragile(void);
+unsigned long __must_check copy_mc_fragile(void *dst, const void *src, unsigned cnt);
+#else
+static inline void enable_copy_mc_fragile(void)
+{
+}
+#endif
+
#ifdef CONFIG_X86_MCE
int mcheck_init(void);
void mcheck_cpu_init(struct cpuinfo_x86 *c);
diff --git a/arch/x86/include/asm/mcsafe_test.h b/arch/x86/include/asm/mcsafe_test.h
deleted file mode 100644
index eb59804b6201..000000000000
--- a/arch/x86/include/asm/mcsafe_test.h
+++ /dev/null
@@ -1,75 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef _MCSAFE_TEST_H_
-#define _MCSAFE_TEST_H_
-
-#ifndef __ASSEMBLY__
-#ifdef CONFIG_MCSAFE_TEST
-extern unsigned long mcsafe_test_src;
-extern unsigned long mcsafe_test_dst;
-
-static inline void mcsafe_inject_src(void *addr)
-{
- if (addr)
- mcsafe_test_src = (unsigned long) addr;
- else
- mcsafe_test_src = ~0UL;
-}
-
-static inline void mcsafe_inject_dst(void *addr)
-{
- if (addr)
- mcsafe_test_dst = (unsigned long) addr;
- else
- mcsafe_test_dst = ~0UL;
-}
-#else /* CONFIG_MCSAFE_TEST */
-static inline void mcsafe_inject_src(void *addr)
-{
-}
-
-static inline void mcsafe_inject_dst(void *addr)
-{
-}
-#endif /* CONFIG_MCSAFE_TEST */
-
-#else /* __ASSEMBLY__ */
-#include <asm/export.h>
-
-#ifdef CONFIG_MCSAFE_TEST
-.macro MCSAFE_TEST_CTL
- .pushsection .data
- .align 8
- .globl mcsafe_test_src
- mcsafe_test_src:
- .quad 0
- EXPORT_SYMBOL_GPL(mcsafe_test_src)
- .globl mcsafe_test_dst
- mcsafe_test_dst:
- .quad 0
- EXPORT_SYMBOL_GPL(mcsafe_test_dst)
- .popsection
-.endm
-
-.macro MCSAFE_TEST_SRC reg count target
- leaq \count(\reg), %r9
- cmp mcsafe_test_src, %r9
- ja \target
-.endm
-
-.macro MCSAFE_TEST_DST reg count target
- leaq \count(\reg), %r9
- cmp mcsafe_test_dst, %r9
- ja \target
-.endm
-#else
-.macro MCSAFE_TEST_CTL
-.endm
-
-.macro MCSAFE_TEST_SRC reg count target
-.endm
-
-.macro MCSAFE_TEST_DST reg count target
-.endm
-#endif /* CONFIG_MCSAFE_TEST */
-#endif /* __ASSEMBLY__ */
-#endif /* _MCSAFE_TEST_H_ */
diff --git a/arch/x86/include/asm/string_64.h b/arch/x86/include/asm/string_64.h
index 75314c3dbe47..6e450827f677 100644
--- a/arch/x86/include/asm/string_64.h
+++ b/arch/x86/include/asm/string_64.h
@@ -82,38 +82,6 @@ int strcmp(const char *cs, const char *ct);
#endif
-#define __HAVE_ARCH_MEMCPY_MCSAFE 1
-__must_check unsigned long __memcpy_mcsafe(void *dst, const void *src,
- size_t cnt);
-DECLARE_STATIC_KEY_FALSE(mcsafe_key);
-
-/**
- * memcpy_mcsafe - copy memory with indication if a machine check happened
- *
- * @dst: destination address
- * @src: source address
- * @cnt: number of bytes to copy
- *
- * Low level memory copy function that catches machine checks
- * We only call into the "safe" function on systems that can
- * actually do machine check recovery. Everyone else can just
- * use memcpy().
- *
- * Return 0 for success, or number of bytes not copied if there was an
- * exception.
- */
-static __always_inline __must_check unsigned long
-memcpy_mcsafe(void *dst, const void *src, size_t cnt)
-{
-#ifdef CONFIG_X86_MCE
- if (static_branch_unlikely(&mcsafe_key))
- return __memcpy_mcsafe(dst, src, cnt);
- else
-#endif
- memcpy(dst, src, cnt);
- return 0;
-}
-
#ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE
#define __HAVE_ARCH_MEMCPY_FLUSHCACHE 1
void __memcpy_flushcache(void *dst, const void *src, size_t cnt);
diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h
index ecefaffd15d4..eff7fb847149 100644
--- a/arch/x86/include/asm/uaccess.h
+++ b/arch/x86/include/asm/uaccess.h
@@ -455,6 +455,15 @@ extern __must_check long strnlen_user(const char __user *str, long n);
unsigned long __must_check clear_user(void __user *mem, unsigned long len);
unsigned long __must_check __clear_user(void __user *mem, unsigned long len);
+#ifdef CONFIG_ARCH_HAS_COPY_MC
+unsigned long __must_check
+copy_mc_to_kernel(void *to, const void *from, unsigned len);
+#define copy_mc_to_kernel copy_mc_to_kernel
+
+unsigned long __must_check
+copy_mc_to_user(void *to, const void *from, unsigned len);
+#endif
+
/*
* movsl can be slow when source and dest are not both 8-byte aligned
*/
diff --git a/arch/x86/include/asm/uaccess_64.h b/arch/x86/include/asm/uaccess_64.h
index bc10e3dc64fe..e7265a552f4f 100644
--- a/arch/x86/include/asm/uaccess_64.h
+++ b/arch/x86/include/asm/uaccess_64.h
@@ -46,22 +46,6 @@ copy_user_generic(void *to, const void *from, unsigned len)
return ret;
}
-static __always_inline __must_check unsigned long
-copy_to_user_mcsafe(void *to, const void *from, unsigned len)
-{
- unsigned long ret;
-
- __uaccess_begin();
- /*
- * Note, __memcpy_mcsafe() is explicitly used since it can
- * handle exceptions / faults. memcpy_mcsafe() may fall back to
- * memcpy() which lacks this handling.
- */
- ret = __memcpy_mcsafe(to, from, len);
- __uaccess_end();
- return ret;
-}
-
static __always_inline __must_check unsigned long
raw_copy_from_user(void *dst, const void __user *src, unsigned long size)
{
@@ -102,8 +86,4 @@ __copy_from_user_flushcache(void *dst, const void __user *src, unsigned size)
kasan_check_write(dst, size);
return __copy_user_flushcache(dst, src, size);
}
-
-unsigned long
-mcsafe_handle_tail(char *to, char *from, unsigned len);
-
#endif /* _ASM_X86_UACCESS_64_H */
diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c
index 11b6697be010..b5b70f4b351d 100644
--- a/arch/x86/kernel/cpu/mce/core.c
+++ b/arch/x86/kernel/cpu/mce/core.c
@@ -40,7 +40,6 @@
#include <linux/debugfs.h>
#include <linux/irq_work.h>
#include <linux/export.h>
-#include <linux/jump_label.h>
#include <linux/set_memory.h>
#include <linux/sync_core.h>
#include <linux/task_work.h>
@@ -2124,7 +2123,7 @@ void mce_disable_bank(int bank)
and older.
* mce=nobootlog Don't log MCEs from before booting.
* mce=bios_cmci_threshold Don't program the CMCI threshold
- * mce=recovery force enable memcpy_mcsafe()
+ * mce=recovery force enable copy_mc_fragile()
*/
static int __init mcheck_enable(char *str)
{
@@ -2732,13 +2731,10 @@ static void __init mcheck_debugfs_init(void)
static void __init mcheck_debugfs_init(void) { }
#endif
-DEFINE_STATIC_KEY_FALSE(mcsafe_key);
-EXPORT_SYMBOL_GPL(mcsafe_key);
-
static int __init mcheck_late_init(void)
{
if (mca_cfg.recovery)
- static_branch_inc(&mcsafe_key);
+ enable_copy_mc_fragile();
mcheck_debugfs_init();
diff --git a/arch/x86/kernel/quirks.c b/arch/x86/kernel/quirks.c
index 1b10717c9321..6d0df6a58873 100644
--- a/arch/x86/kernel/quirks.c
+++ b/arch/x86/kernel/quirks.c
@@ -8,6 +8,7 @@
#include <asm/hpet.h>
#include <asm/setup.h>
+#include <asm/mce.h>
#if defined(CONFIG_X86_IO_APIC) && defined(CONFIG_SMP) && defined(CONFIG_PCI)
@@ -624,10 +625,6 @@ static void amd_disable_seq_and_redirect_scrub(struct pci_dev *dev)
DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_16H_NB_F3,
amd_disable_seq_and_redirect_scrub);
-#if defined(CONFIG_X86_64) && defined(CONFIG_X86_MCE)
-#include <linux/jump_label.h>
-#include <asm/string_64.h>
-
/* Ivy Bridge, Haswell, Broadwell */
static void quirk_intel_brickland_xeon_ras_cap(struct pci_dev *pdev)
{
@@ -636,7 +633,7 @@ static void quirk_intel_brickland_xeon_ras_cap(struct pci_dev *pdev)
pci_read_config_dword(pdev, 0x84, &capid0);
if (capid0 & 0x10)
- static_branch_inc(&mcsafe_key);
+ enable_copy_mc_fragile();
}
/* Skylake */
@@ -653,7 +650,7 @@ static void quirk_intel_purley_xeon_ras_cap(struct pci_dev *pdev)
* enabled, so memory machine check recovery is also enabled.
*/
if ((capid0 & 0xc0) == 0xc0 || (capid5 & 0x1e0))
- static_branch_inc(&mcsafe_key);
+ enable_copy_mc_fragile();
}
DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x0ec3, quirk_intel_brickland_xeon_ras_cap);
@@ -661,7 +658,6 @@ DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x2fc0, quirk_intel_brickland_xeon_
DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x6fc0, quirk_intel_brickland_xeon_ras_cap);
DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x2083, quirk_intel_purley_xeon_ras_cap);
#endif
-#endif
bool x86_apple_machine;
EXPORT_SYMBOL(x86_apple_machine);
diff --git a/arch/x86/lib/Makefile b/arch/x86/lib/Makefile
index d46fff11f06f..f7d23c9c22b2 100644
--- a/arch/x86/lib/Makefile
+++ b/arch/x86/lib/Makefile
@@ -44,6 +44,7 @@ obj-$(CONFIG_SMP) += msr-smp.o cache-smp.o
lib-y := delay.o misc.o cmdline.o cpu.o
lib-y += usercopy_$(BITS).o usercopy.o getuser.o putuser.o
lib-y += memcpy_$(BITS).o
+lib-$(CONFIG_ARCH_HAS_COPY_MC) += copy_mc.o copy_mc_64.o
lib-$(CONFIG_INSTRUCTION_DECODER) += insn.o inat.o insn-eval.o
lib-$(CONFIG_RANDOMIZE_BASE) += kaslr.o
lib-$(CONFIG_FUNCTION_ERROR_INJECTION) += error-inject.o
diff --git a/arch/x86/lib/copy_mc.c b/arch/x86/lib/copy_mc.c
new file mode 100644
index 000000000000..2633635530b7
--- /dev/null
+++ b/arch/x86/lib/copy_mc.c
@@ -0,0 +1,82 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright(c) 2016-2020 Intel Corporation. All rights reserved. */
+
+#include <linux/jump_label.h>
+#include <linux/uaccess.h>
+#include <linux/export.h>
+#include <linux/string.h>
+#include <linux/types.h>
+
+#include <asm/mce.h>
+
+#ifdef CONFIG_X86_MCE
+/*
+ * See COPY_MC_TEST for self-test of the copy_mc_fragile()
+ * implementation.
+ */
+static DEFINE_STATIC_KEY_FALSE(copy_mc_fragile_key);
+
+void enable_copy_mc_fragile(void)
+{
+ static_branch_inc(©_mc_fragile_key);
+}
+#define copy_mc_fragile_enabled (static_branch_unlikely(©_mc_fragile_key))
+
+/*
+ * Similar to copy_user_handle_tail, probe for the write fault point, or
+ * source exception point.
+ */
+__visible notrace unsigned long
+copy_mc_fragile_handle_tail(char *to, char *from, unsigned len)
+{
+ for (; len; --len, to++, from++)
+ if (copy_mc_fragile(to, from, 1))
+ break;
+ return len;
+}
+#else
+/*
+ * No point in doing careful copying, or consulting a static key when
+ * there is no #MC handler in the CONFIG_X86_MCE=n case.
+ */
+void enable_copy_mc_fragile(void)
+{
+}
+#define copy_mc_fragile_enabled (0)
+#endif
+
+/**
+ * copy_mc_to_kernel - memory copy that handles source exceptions
+ *
+ * @dst: destination address
+ * @src: source address
+ * @len: number of bytes to copy
+ *
+ * Call into the 'fragile' version on systems that have trouble
+ * actually do machine check recovery. Everyone else can just
+ * use memcpy().
+ *
+ * Return 0 for success, or number of bytes not copied if there was an
+ * exception.
+ */
+unsigned long __must_check copy_mc_to_kernel(void *dst, const void *src, unsigned len)
+{
+ if (copy_mc_fragile_enabled)
+ return copy_mc_fragile(dst, src, len);
+ memcpy(dst, src, len);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(copy_mc_to_kernel);
+
+unsigned long __must_check copy_mc_to_user(void *dst, const void *src, unsigned len)
+{
+ unsigned long ret;
+
+ if (!copy_mc_fragile_enabled)
+ return copy_user_generic(dst, src, len);
+
+ __uaccess_begin();
+ ret = copy_mc_fragile(dst, src, len);
+ __uaccess_end();
+ return ret;
+}
diff --git a/arch/x86/lib/copy_mc_64.S b/arch/x86/lib/copy_mc_64.S
new file mode 100644
index 000000000000..c3b613c4544a
--- /dev/null
+++ b/arch/x86/lib/copy_mc_64.S
@@ -0,0 +1,127 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* Copyright(c) 2016-2020 Intel Corporation. All rights reserved. */
+
+#include <linux/linkage.h>
+#include <asm/copy_mc_test.h>
+#include <asm/export.h>
+#include <asm/asm.h>
+
+#ifndef CONFIG_UML
+
+#ifdef CONFIG_X86_MCE
+COPY_MC_TEST_CTL
+
+/*
+ * copy_mc_fragile - copy memory with indication if an exception / fault happened
+ *
+ * The 'fragile' version is opted into by platform quirks and takes
+ * pains to avoid unrecoverable corner cases like 'fast-string'
+ * instruction sequences, and consuming poison across a cacheline
+ * boundary. The non-fragile version is equivalent to memcpy()
+ * regardless of CPU machine-check-recovery capability.
+ */
+SYM_FUNC_START(copy_mc_fragile)
+ cmpl $8, %edx
+ /* Less than 8 bytes? Go to byte copy loop */
+ jb .L_no_whole_words
+
+ /* Check for bad alignment of source */
+ testl $7, %esi
+ /* Already aligned */
+ jz .L_8byte_aligned
+
+ /* Copy one byte at a time until source is 8-byte aligned */
+ movl %esi, %ecx
+ andl $7, %ecx
+ subl $8, %ecx
+ negl %ecx
+ subl %ecx, %edx
+.L_read_leading_bytes:
+ movb (%rsi), %al
+ COPY_MC_TEST_SRC %rsi 1 .E_leading_bytes
+ COPY_MC_TEST_DST %rdi 1 .E_leading_bytes
+.L_write_leading_bytes:
+ movb %al, (%rdi)
+ incq %rsi
+ incq %rdi
+ decl %ecx
+ jnz .L_read_leading_bytes
+
+.L_8byte_aligned:
+ movl %edx, %ecx
+ andl $7, %edx
+ shrl $3, %ecx
+ jz .L_no_whole_words
+
+.L_read_words:
+ movq (%rsi), %r8
+ COPY_MC_TEST_SRC %rsi 8 .E_read_words
+ COPY_MC_TEST_DST %rdi 8 .E_write_words
+.L_write_words:
+ movq %r8, (%rdi)
+ addq $8, %rsi
+ addq $8, %rdi
+ decl %ecx
+ jnz .L_read_words
+
+ /* Any trailing bytes? */
+.L_no_whole_words:
+ andl %edx, %edx
+ jz .L_done_memcpy_trap
+
+ /* Copy trailing bytes */
+ movl %edx, %ecx
+.L_read_trailing_bytes:
+ movb (%rsi), %al
+ COPY_MC_TEST_SRC %rsi 1 .E_trailing_bytes
+ COPY_MC_TEST_DST %rdi 1 .E_trailing_bytes
+.L_write_trailing_bytes:
+ movb %al, (%rdi)
+ incq %rsi
+ incq %rdi
+ decl %ecx
+ jnz .L_read_trailing_bytes
+
+ /* Copy successful. Return zero */
+.L_done_memcpy_trap:
+ xorl %eax, %eax
+.L_done:
+ ret
+SYM_FUNC_END(copy_mc_fragile)
+EXPORT_SYMBOL_GPL(copy_mc_fragile)
+
+ .section .fixup, "ax"
+ /*
+ * Return number of bytes not copied for any failure. Note that
+ * there is no "tail" handling since the source buffer is 8-byte
+ * aligned and poison is cacheline aligned.
+ */
+.E_read_words:
+ shll $3, %ecx
+.E_leading_bytes:
+ addl %edx, %ecx
+.E_trailing_bytes:
+ mov %ecx, %eax
+ jmp .L_done
+
+ /*
+ * For write fault handling, given the destination is unaligned,
+ * we handle faults on multi-byte writes with a byte-by-byte
+ * copy up to the write-protected page.
+ */
+.E_write_words:
+ shll $3, %ecx
+ addl %edx, %ecx
+ movl %ecx, %edx
+ jmp copy_mc_fragile_handle_tail
+
+ .previous
+
+ _ASM_EXTABLE_FAULT(.L_read_leading_bytes, .E_leading_bytes)
+ _ASM_EXTABLE_FAULT(.L_read_words, .E_read_words)
+ _ASM_EXTABLE_FAULT(.L_read_trailing_bytes, .E_trailing_bytes)
+ _ASM_EXTABLE(.L_write_leading_bytes, .E_leading_bytes)
+ _ASM_EXTABLE(.L_write_words, .E_write_words)
+ _ASM_EXTABLE(.L_write_trailing_bytes, .E_trailing_bytes)
+#endif /* CONFIG_X86_MCE */
+#endif /* !CONFIG_UML */
diff --git a/arch/x86/lib/memcpy_64.S b/arch/x86/lib/memcpy_64.S
index bbcc05bcefad..037faac46b0c 100644
--- a/arch/x86/lib/memcpy_64.S
+++ b/arch/x86/lib/memcpy_64.S
@@ -4,7 +4,6 @@
#include <linux/linkage.h>
#include <asm/errno.h>
#include <asm/cpufeatures.h>
-#include <asm/mcsafe_test.h>
#include <asm/alternative-asm.h>
#include <asm/export.h>
@@ -187,117 +186,3 @@ SYM_FUNC_START_LOCAL(memcpy_orig)
SYM_FUNC_END(memcpy_orig)
.popsection
-
-#ifndef CONFIG_UML
-
-MCSAFE_TEST_CTL
-
-/*
- * __memcpy_mcsafe - memory copy with machine check exception handling
- * Note that we only catch machine checks when reading the source addresses.
- * Writes to target are posted and don't generate machine checks.
- */
-SYM_FUNC_START(__memcpy_mcsafe)
- cmpl $8, %edx
- /* Less than 8 bytes? Go to byte copy loop */
- jb .L_no_whole_words
-
- /* Check for bad alignment of source */
- testl $7, %esi
- /* Already aligned */
- jz .L_8byte_aligned
-
- /* Copy one byte at a time until source is 8-byte aligned */
- movl %esi, %ecx
- andl $7, %ecx
- subl $8, %ecx
- negl %ecx
- subl %ecx, %edx
-.L_read_leading_bytes:
- movb (%rsi), %al
- MCSAFE_TEST_SRC %rsi 1 .E_leading_bytes
- MCSAFE_TEST_DST %rdi 1 .E_leading_bytes
-.L_write_leading_bytes:
- movb %al, (%rdi)
- incq %rsi
- incq %rdi
- decl %ecx
- jnz .L_read_leading_bytes
-
-.L_8byte_aligned:
- movl %edx, %ecx
- andl $7, %edx
- shrl $3, %ecx
- jz .L_no_whole_words
-
-.L_read_words:
- movq (%rsi), %r8
- MCSAFE_TEST_SRC %rsi 8 .E_read_words
- MCSAFE_TEST_DST %rdi 8 .E_write_words
-.L_write_words:
- movq %r8, (%rdi)
- addq $8, %rsi
- addq $8, %rdi
- decl %ecx
- jnz .L_read_words
-
- /* Any trailing bytes? */
-.L_no_whole_words:
- andl %edx, %edx
- jz .L_done_memcpy_trap
-
- /* Copy trailing bytes */
- movl %edx, %ecx
-.L_read_trailing_bytes:
- movb (%rsi), %al
- MCSAFE_TEST_SRC %rsi 1 .E_trailing_bytes
- MCSAFE_TEST_DST %rdi 1 .E_trailing_bytes
-.L_write_trailing_bytes:
- movb %al, (%rdi)
- incq %rsi
- incq %rdi
- decl %ecx
- jnz .L_read_trailing_bytes
-
- /* Copy successful. Return zero */
-.L_done_memcpy_trap:
- xorl %eax, %eax
-.L_done:
- ret
-SYM_FUNC_END(__memcpy_mcsafe)
-EXPORT_SYMBOL_GPL(__memcpy_mcsafe)
-
- .section .fixup, "ax"
- /*
- * Return number of bytes not copied for any failure. Note that
- * there is no "tail" handling since the source buffer is 8-byte
- * aligned and poison is cacheline aligned.
- */
-.E_read_words:
- shll $3, %ecx
-.E_leading_bytes:
- addl %edx, %ecx
-.E_trailing_bytes:
- mov %ecx, %eax
- jmp .L_done
-
- /*
- * For write fault handling, given the destination is unaligned,
- * we handle faults on multi-byte writes with a byte-by-byte
- * copy up to the write-protected page.
- */
-.E_write_words:
- shll $3, %ecx
- addl %edx, %ecx
- movl %ecx, %edx
- jmp mcsafe_handle_tail
-
- .previous
-
- _ASM_EXTABLE_FAULT(.L_read_leading_bytes, .E_leading_bytes)
- _ASM_EXTABLE_FAULT(.L_read_words, .E_read_words)
- _ASM_EXTABLE_FAULT(.L_read_trailing_bytes, .E_trailing_bytes)
- _ASM_EXTABLE(.L_write_leading_bytes, .E_leading_bytes)
- _ASM_EXTABLE(.L_write_words, .E_write_words)
- _ASM_EXTABLE(.L_write_trailing_bytes, .E_trailing_bytes)
-#endif
diff --git a/arch/x86/lib/usercopy_64.c b/arch/x86/lib/usercopy_64.c
index b0dfac3d3df7..5f1d4a9ebd5a 100644
--- a/arch/x86/lib/usercopy_64.c
+++ b/arch/x86/lib/usercopy_64.c
@@ -56,27 +56,6 @@ unsigned long clear_user(void __user *to, unsigned long n)
}
EXPORT_SYMBOL(clear_user);
-/*
- * Similar to copy_user_handle_tail, probe for the write fault point,
- * but reuse __memcpy_mcsafe in case a new read error is encountered.
- * clac() is handled in _copy_to_iter_mcsafe().
- */
-__visible notrace unsigned long
-mcsafe_handle_tail(char *to, char *from, unsigned len)
-{
- for (; len; --len, to++, from++) {
- /*
- * Call the assembly routine back directly since
- * memcpy_mcsafe() may silently fallback to memcpy.
- */
- unsigned long rem = __memcpy_mcsafe(to, from, 1);
-
- if (rem)
- break;
- }
- return len;
-}
-
#ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE
/**
* clean_cache_range - write back a cache range with CLWB
diff --git a/drivers/md/dm-writecache.c b/drivers/md/dm-writecache.c
index 86dbe0c8b45c..9fc18fadacc6 100644
--- a/drivers/md/dm-writecache.c
+++ b/drivers/md/dm-writecache.c
@@ -49,7 +49,7 @@ do { \
#define pmem_assign(dest, src) ((dest) = (src))
#endif
-#if defined(__HAVE_ARCH_MEMCPY_MCSAFE) && defined(DM_WRITECACHE_HAS_PMEM)
+#if IS_ENABLED(CONFIG_ARCH_HAS_COPY_MC) && defined(DM_WRITECACHE_HAS_PMEM)
#define DM_WRITECACHE_HANDLE_HARDWARE_ERRORS
#endif
@@ -984,7 +984,8 @@ static void writecache_resume(struct dm_target *ti)
}
wc->freelist_size = 0;
- r = memcpy_mcsafe(&sb_seq_count, &sb(wc)->seq_count, sizeof(uint64_t));
+ r = copy_mc_to_kernel(&sb_seq_count, &sb(wc)->seq_count,
+ sizeof(uint64_t));
if (r) {
writecache_error(wc, r, "hardware memory error when reading superblock: %d", r);
sb_seq_count = cpu_to_le64(0);
@@ -1000,7 +1001,8 @@ static void writecache_resume(struct dm_target *ti)
e->seq_count = -1;
continue;
}
- r = memcpy_mcsafe(&wme, memory_entry(wc, e), sizeof(struct wc_memory_entry));
+ r = copy_mc_to_kernel(&wme, memory_entry(wc, e),
+ sizeof(struct wc_memory_entry));
if (r) {
writecache_error(wc, r, "hardware memory error when reading metadata entry %lu: %d",
(unsigned long)b, r);
@@ -1198,7 +1200,7 @@ static void bio_copy_block(struct dm_writecache *wc, struct bio *bio, void *data
if (rw == READ) {
int r;
- r = memcpy_mcsafe(buf, data, size);
+ r = copy_mc_to_kernel(buf, data, size);
flush_dcache_page(bio_page(bio));
if (unlikely(r)) {
writecache_error(wc, r, "hardware memory error when reading data: %d", r);
@@ -2341,7 +2343,7 @@ static int writecache_ctr(struct dm_target *ti, unsigned argc, char **argv)
}
}
- r = memcpy_mcsafe(&s, sb(wc), sizeof(struct wc_memory_superblock));
+ r = copy_mc_to_kernel(&s, sb(wc), sizeof(struct wc_memory_superblock));
if (r) {
ti->error = "Hardware memory error when reading superblock";
goto bad;
@@ -2352,7 +2354,8 @@ static int writecache_ctr(struct dm_target *ti, unsigned argc, char **argv)
ti->error = "Unable to initialize device";
goto bad;
}
- r = memcpy_mcsafe(&s, sb(wc), sizeof(struct wc_memory_superblock));
+ r = copy_mc_to_kernel(&s, sb(wc),
+ sizeof(struct wc_memory_superblock));
if (r) {
ti->error = "Hardware memory error when reading superblock";
goto bad;
diff --git a/drivers/nvdimm/claim.c b/drivers/nvdimm/claim.c
index 45964acba944..22d865ba6353 100644
--- a/drivers/nvdimm/claim.c
+++ b/drivers/nvdimm/claim.c
@@ -268,7 +268,7 @@ static int nsio_rw_bytes(struct nd_namespace_common *ndns,
if (rw == READ) {
if (unlikely(is_bad_pmem(&nsio->bb, sector, sz_align)))
return -EIO;
- if (memcpy_mcsafe(buf, nsio->addr + offset, size) != 0)
+ if (copy_mc_to_kernel(buf, nsio->addr + offset, size) != 0)
return -EIO;
return 0;
}
diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index fab29b514372..5c6939e004e2 100644
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c
@@ -125,7 +125,7 @@ static blk_status_t read_pmem(struct page *page, unsigned int off,
while (len) {
mem = kmap_atomic(page);
chunk = min_t(unsigned int, len, PAGE_SIZE - off);
- rem = memcpy_mcsafe(mem + off, pmem_addr, chunk);
+ rem = copy_mc_to_kernel(mem + off, pmem_addr, chunk);
kunmap_atomic(mem);
if (rem)
return BLK_STS_IOERR;
@@ -304,7 +304,7 @@ static long pmem_dax_direct_access(struct dax_device *dax_dev,
/*
* Use the 'no check' versions of copy_from_iter_flushcache() and
- * copy_to_iter_mcsafe() to bypass HARDENED_USERCOPY overhead. Bounds
+ * copy_mc_to_iter() to bypass HARDENED_USERCOPY overhead. Bounds
* checking, both file offset and device offset, is handled by
* dax_iomap_actor()
*/
@@ -317,7 +317,7 @@ static size_t pmem_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff,
static size_t pmem_copy_to_iter(struct dax_device *dax_dev, pgoff_t pgoff,
void *addr, size_t bytes, struct iov_iter *i)
{
- return _copy_to_iter_mcsafe(addr, bytes, i);
+ return _copy_mc_to_iter(addr, bytes, i);
}
static const struct dax_operations pmem_dax_ops = {
diff --git a/include/linux/string.h b/include/linux/string.h
index 9b7a0632e87a..b1f3894a0a3e 100644
--- a/include/linux/string.h
+++ b/include/linux/string.h
@@ -161,20 +161,13 @@ extern int bcmp(const void *,const void *,__kernel_size_t);
#ifndef __HAVE_ARCH_MEMCHR
extern void * memchr(const void *,int,__kernel_size_t);
#endif
-#ifndef __HAVE_ARCH_MEMCPY_MCSAFE
-static inline __must_check unsigned long memcpy_mcsafe(void *dst,
- const void *src, size_t cnt)
-{
- memcpy(dst, src, cnt);
- return 0;
-}
-#endif
#ifndef __HAVE_ARCH_MEMCPY_FLUSHCACHE
static inline void memcpy_flushcache(void *dst, const void *src, size_t cnt)
{
memcpy(dst, src, cnt);
}
#endif
+
void *memchr_inv(const void *s, int c, size_t n);
char *strreplace(char *s, char old, char new);
diff --git a/include/linux/uaccess.h b/include/linux/uaccess.h
index 94b285411659..1ae36bc8db35 100644
--- a/include/linux/uaccess.h
+++ b/include/linux/uaccess.h
@@ -179,6 +179,19 @@ copy_in_user(void __user *to, const void __user *from, unsigned long n)
}
#endif
+#ifndef copy_mc_to_kernel
+/*
+ * Without arch opt-in this generic copy_mc_to_kernel() will not handle
+ * #MC (or arch equivalent) during source read.
+ */
+static inline unsigned long __must_check
+copy_mc_to_kernel(void *dst, const void *src, size_t cnt)
+{
+ memcpy(dst, src, cnt);
+ return 0;
+}
+#endif
+
static __always_inline void pagefault_disabled_inc(void)
{
current->pagefault_disabled++;
diff --git a/include/linux/uio.h b/include/linux/uio.h
index 3835a8a8e9ea..f14410c678bd 100644
--- a/include/linux/uio.h
+++ b/include/linux/uio.h
@@ -185,10 +185,10 @@ size_t _copy_from_iter_flushcache(void *addr, size_t bytes, struct iov_iter *i);
#define _copy_from_iter_flushcache _copy_from_iter_nocache
#endif
-#ifdef CONFIG_ARCH_HAS_UACCESS_MCSAFE
-size_t _copy_to_iter_mcsafe(const void *addr, size_t bytes, struct iov_iter *i);
+#ifdef CONFIG_ARCH_HAS_COPY_MC
+size_t _copy_mc_to_iter(const void *addr, size_t bytes, struct iov_iter *i);
#else
-#define _copy_to_iter_mcsafe _copy_to_iter
+#define _copy_mc_to_iter _copy_to_iter
#endif
static __always_inline __must_check
@@ -201,12 +201,12 @@ size_t copy_from_iter_flushcache(void *addr, size_t bytes, struct iov_iter *i)
}
static __always_inline __must_check
-size_t copy_to_iter_mcsafe(void *addr, size_t bytes, struct iov_iter *i)
+size_t copy_mc_to_iter(void *addr, size_t bytes, struct iov_iter *i)
{
if (unlikely(!check_copy_size(addr, bytes, true)))
return 0;
else
- return _copy_to_iter_mcsafe(addr, bytes, i);
+ return _copy_mc_to_iter(addr, bytes, i);
}
size_t iov_iter_zero(size_t bytes, struct iov_iter *);
diff --git a/lib/Kconfig b/lib/Kconfig
index b4b98a03ff98..b46a9fd122c8 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -635,7 +635,12 @@ config UACCESS_MEMCPY
config ARCH_HAS_UACCESS_FLUSHCACHE
bool
-config ARCH_HAS_UACCESS_MCSAFE
+# arch has a concept of a recoverable synchronous exception due to a
+# memory-read error like x86 machine-check or ARM data-abort, and
+# implements copy_mc_to_{user,kernel} to abort and report
+# 'bytes-transferred' if that exception fires when accessing the source
+# buffer.
+config ARCH_HAS_COPY_MC
bool
# Temporary. Goes away when all archs are cleaned up
diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index 5e40786c8f12..d13304a034f5 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -637,30 +637,30 @@ size_t _copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i)
}
EXPORT_SYMBOL(_copy_to_iter);
-#ifdef CONFIG_ARCH_HAS_UACCESS_MCSAFE
-static int copyout_mcsafe(void __user *to, const void *from, size_t n)
+#ifdef CONFIG_ARCH_HAS_COPY_MC
+static int copyout_mc(void __user *to, const void *from, size_t n)
{
if (access_ok(to, n)) {
instrument_copy_to_user(to, from, n);
- n = copy_to_user_mcsafe((__force void *) to, from, n);
+ n = copy_mc_to_user((__force void *) to, from, n);
}
return n;
}
-static unsigned long memcpy_mcsafe_to_page(struct page *page, size_t offset,
+static unsigned long copy_mc_to_page(struct page *page, size_t offset,
const char *from, size_t len)
{
unsigned long ret;
char *to;
to = kmap_atomic(page);
- ret = memcpy_mcsafe(to + offset, from, len);
+ ret = copy_mc_to_kernel(to + offset, from, len);
kunmap_atomic(to);
return ret;
}
-static size_t copy_pipe_to_iter_mcsafe(const void *addr, size_t bytes,
+static size_t copy_mc_pipe_to_iter(const void *addr, size_t bytes,
struct iov_iter *i)
{
struct pipe_inode_info *pipe = i->pipe;
@@ -678,7 +678,7 @@ static size_t copy_pipe_to_iter_mcsafe(const void *addr, size_t bytes,
size_t chunk = min_t(size_t, n, PAGE_SIZE - off);
unsigned long rem;
- rem = memcpy_mcsafe_to_page(pipe->bufs[i_head & p_mask].page,
+ rem = copy_mc_to_page(pipe->bufs[i_head & p_mask].page,
off, addr, chunk);
i->head = i_head;
i->iov_offset = off + chunk - rem;
@@ -695,18 +695,17 @@ static size_t copy_pipe_to_iter_mcsafe(const void *addr, size_t bytes,
}
/**
- * _copy_to_iter_mcsafe - copy to user with source-read error exception handling
+ * _copy_mc_to_iter - copy to iter with source memory error exception handling
* @addr: source kernel address
* @bytes: total transfer length
* @iter: destination iterator
*
- * The pmem driver arranges for filesystem-dax to use this facility via
- * dax_copy_to_iter() for protecting read/write to persistent memory.
- * Unless / until an architecture can guarantee identical performance
- * between _copy_to_iter_mcsafe() and _copy_to_iter() it would be a
- * performance regression to switch more users to the mcsafe version.
+ * The pmem driver deploys this for the dax operation
+ * (dax_copy_to_iter()) for dax reads (bypass page-cache and the
+ * block-layer). Upon #MC read(2) aborts and returns EIO or the bytes
+ * successfully copied.
*
- * Otherwise, the main differences between this and typical _copy_to_iter().
+ * The main differences between this and typical _copy_to_iter().
*
* * Typical tail/residue handling after a fault retries the copy
* byte-by-byte until the fault happens again. Re-triggering machine
@@ -717,23 +716,22 @@ static size_t copy_pipe_to_iter_mcsafe(const void *addr, size_t bytes,
* * ITER_KVEC, ITER_PIPE, and ITER_BVEC can return short copies.
* Compare to copy_to_iter() where only ITER_IOVEC attempts might return
* a short copy.
- *
- * See MCSAFE_TEST for self-test.
*/
-size_t _copy_to_iter_mcsafe(const void *addr, size_t bytes, struct iov_iter *i)
+size_t _copy_mc_to_iter(const void *addr, size_t bytes, struct iov_iter *i)
{
const char *from = addr;
unsigned long rem, curr_addr, s_addr = (unsigned long) addr;
if (unlikely(iov_iter_is_pipe(i)))
- return copy_pipe_to_iter_mcsafe(addr, bytes, i);
+ return copy_mc_pipe_to_iter(addr, bytes, i);
if (iter_is_iovec(i))
might_fault();
iterate_and_advance(i, bytes, v,
- copyout_mcsafe(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len),
+ copyout_mc(v.iov_base, (from += v.iov_len) - v.iov_len,
+ v.iov_len),
({
- rem = memcpy_mcsafe_to_page(v.bv_page, v.bv_offset,
- (from += v.bv_len) - v.bv_len, v.bv_len);
+ rem = copy_mc_to_page(v.bv_page, v.bv_offset,
+ (from += v.bv_len) - v.bv_len, v.bv_len);
if (rem) {
curr_addr = (unsigned long) from;
bytes = curr_addr - s_addr - rem;
@@ -741,8 +739,8 @@ size_t _copy_to_iter_mcsafe(const void *addr, size_t bytes, struct iov_iter *i)
}
}),
({
- rem = memcpy_mcsafe(v.iov_base, (from += v.iov_len) - v.iov_len,
- v.iov_len);
+ rem = copy_mc_to_kernel(v.iov_base, (from += v.iov_len)
+ - v.iov_len, v.iov_len);
if (rem) {
curr_addr = (unsigned long) from;
bytes = curr_addr - s_addr - rem;
@@ -753,8 +751,8 @@ size_t _copy_to_iter_mcsafe(const void *addr, size_t bytes, struct iov_iter *i)
return bytes;
}
-EXPORT_SYMBOL_GPL(_copy_to_iter_mcsafe);
-#endif /* CONFIG_ARCH_HAS_UACCESS_MCSAFE */
+EXPORT_SYMBOL_GPL(_copy_mc_to_iter);
+#endif /* CONFIG_ARCH_HAS_COPY_MC */
size_t _copy_from_iter(void *addr, size_t bytes, struct iov_iter *i)
{
diff --git a/tools/arch/x86/include/asm/mcsafe_test.h b/tools/arch/x86/include/asm/mcsafe_test.h
deleted file mode 100644
index 2ccd588fbad4..000000000000
--- a/tools/arch/x86/include/asm/mcsafe_test.h
+++ /dev/null
@@ -1,13 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef _MCSAFE_TEST_H_
-#define _MCSAFE_TEST_H_
-
-.macro MCSAFE_TEST_CTL
-.endm
-
-.macro MCSAFE_TEST_SRC reg count target
-.endm
-
-.macro MCSAFE_TEST_DST reg count target
-.endm
-#endif /* _MCSAFE_TEST_H_ */
diff --git a/tools/arch/x86/lib/memcpy_64.S b/tools/arch/x86/lib/memcpy_64.S
index 45f8e1b02241..0b5b8ae56bd9 100644
--- a/tools/arch/x86/lib/memcpy_64.S
+++ b/tools/arch/x86/lib/memcpy_64.S
@@ -4,7 +4,6 @@
#include <linux/linkage.h>
#include <asm/errno.h>
#include <asm/cpufeatures.h>
-#include <asm/mcsafe_test.h>
#include <asm/alternative-asm.h>
#include <asm/export.h>
@@ -187,117 +186,3 @@ SYM_FUNC_START(memcpy_orig)
SYM_FUNC_END(memcpy_orig)
.popsection
-
-#ifndef CONFIG_UML
-
-MCSAFE_TEST_CTL
-
-/*
- * __memcpy_mcsafe - memory copy with machine check exception handling
- * Note that we only catch machine checks when reading the source addresses.
- * Writes to target are posted and don't generate machine checks.
- */
-SYM_FUNC_START(__memcpy_mcsafe)
- cmpl $8, %edx
- /* Less than 8 bytes? Go to byte copy loop */
- jb .L_no_whole_words
-
- /* Check for bad alignment of source */
- testl $7, %esi
- /* Already aligned */
- jz .L_8byte_aligned
-
- /* Copy one byte at a time until source is 8-byte aligned */
- movl %esi, %ecx
- andl $7, %ecx
- subl $8, %ecx
- negl %ecx
- subl %ecx, %edx
-.L_read_leading_bytes:
- movb (%rsi), %al
- MCSAFE_TEST_SRC %rsi 1 .E_leading_bytes
- MCSAFE_TEST_DST %rdi 1 .E_leading_bytes
-.L_write_leading_bytes:
- movb %al, (%rdi)
- incq %rsi
- incq %rdi
- decl %ecx
- jnz .L_read_leading_bytes
-
-.L_8byte_aligned:
- movl %edx, %ecx
- andl $7, %edx
- shrl $3, %ecx
- jz .L_no_whole_words
-
-.L_read_words:
- movq (%rsi), %r8
- MCSAFE_TEST_SRC %rsi 8 .E_read_words
- MCSAFE_TEST_DST %rdi 8 .E_write_words
-.L_write_words:
- movq %r8, (%rdi)
- addq $8, %rsi
- addq $8, %rdi
- decl %ecx
- jnz .L_read_words
-
- /* Any trailing bytes? */
-.L_no_whole_words:
- andl %edx, %edx
- jz .L_done_memcpy_trap
-
- /* Copy trailing bytes */
- movl %edx, %ecx
-.L_read_trailing_bytes:
- movb (%rsi), %al
- MCSAFE_TEST_SRC %rsi 1 .E_trailing_bytes
- MCSAFE_TEST_DST %rdi 1 .E_trailing_bytes
-.L_write_trailing_bytes:
- movb %al, (%rdi)
- incq %rsi
- incq %rdi
- decl %ecx
- jnz .L_read_trailing_bytes
-
- /* Copy successful. Return zero */
-.L_done_memcpy_trap:
- xorl %eax, %eax
-.L_done:
- ret
-SYM_FUNC_END(__memcpy_mcsafe)
-EXPORT_SYMBOL_GPL(__memcpy_mcsafe)
-
- .section .fixup, "ax"
- /*
- * Return number of bytes not copied for any failure. Note that
- * there is no "tail" handling since the source buffer is 8-byte
- * aligned and poison is cacheline aligned.
- */
-.E_read_words:
- shll $3, %ecx
-.E_leading_bytes:
- addl %edx, %ecx
-.E_trailing_bytes:
- mov %ecx, %eax
- jmp .L_done
-
- /*
- * For write fault handling, given the destination is unaligned,
- * we handle faults on multi-byte writes with a byte-by-byte
- * copy up to the write-protected page.
- */
-.E_write_words:
- shll $3, %ecx
- addl %edx, %ecx
- movl %ecx, %edx
- jmp mcsafe_handle_tail
-
- .previous
-
- _ASM_EXTABLE_FAULT(.L_read_leading_bytes, .E_leading_bytes)
- _ASM_EXTABLE_FAULT(.L_read_words, .E_read_words)
- _ASM_EXTABLE_FAULT(.L_read_trailing_bytes, .E_trailing_bytes)
- _ASM_EXTABLE(.L_write_leading_bytes, .E_leading_bytes)
- _ASM_EXTABLE(.L_write_words, .E_write_words)
- _ASM_EXTABLE(.L_write_trailing_bytes, .E_trailing_bytes)
-#endif
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index e034a8f24f46..893f021fec63 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -548,8 +548,8 @@ static const char *uaccess_safe_builtin[] = {
"__ubsan_handle_shift_out_of_bounds",
/* misc */
"csum_partial_copy_generic",
- "__memcpy_mcsafe",
- "mcsafe_handle_tail",
+ "copy_mc_fragile",
+ "copy_mc_fragile_handle_tail",
"ftrace_likely_update", /* CONFIG_TRACE_BRANCH_PROFILING */
NULL
};
diff --git a/tools/perf/bench/Build b/tools/perf/bench/Build
index dd68a40a790c..878db6a59a41 100644
--- a/tools/perf/bench/Build
+++ b/tools/perf/bench/Build
@@ -13,7 +13,6 @@ perf-y += synthesize.o
perf-y += kallsyms-parse.o
perf-y += find-bit-bench.o
-perf-$(CONFIG_X86_64) += mem-memcpy-x86-64-lib.o
perf-$(CONFIG_X86_64) += mem-memcpy-x86-64-asm.o
perf-$(CONFIG_X86_64) += mem-memset-x86-64-asm.o
diff --git a/tools/perf/bench/mem-memcpy-x86-64-lib.c b/tools/perf/bench/mem-memcpy-x86-64-lib.c
deleted file mode 100644
index 4130734dde84..000000000000
--- a/tools/perf/bench/mem-memcpy-x86-64-lib.c
+++ /dev/null
@@ -1,24 +0,0 @@
-/*
- * From code in arch/x86/lib/usercopy_64.c, copied to keep tools/ copy
- * of the kernel's arch/x86/lib/memcpy_64.s used in 'perf bench mem memcpy'
- * happy.
- */
-#include <linux/types.h>
-
-unsigned long __memcpy_mcsafe(void *dst, const void *src, size_t cnt);
-unsigned long mcsafe_handle_tail(char *to, char *from, unsigned len);
-
-unsigned long mcsafe_handle_tail(char *to, char *from, unsigned len)
-{
- for (; len; --len, to++, from++) {
- /*
- * Call the assembly routine back directly since
- * memcpy_mcsafe() may silently fallback to memcpy.
- */
- unsigned long rem = __memcpy_mcsafe(to, from, 1);
-
- if (rem)
- break;
- }
- return len;
-}
diff --git a/tools/testing/nvdimm/test/nfit.c b/tools/testing/nvdimm/test/nfit.c
index a1a5dc645b40..2ac0fff6dad8 100644
--- a/tools/testing/nvdimm/test/nfit.c
+++ b/tools/testing/nvdimm/test/nfit.c
@@ -23,7 +23,8 @@
#include "nfit_test.h"
#include "../watermark.h"
-#include <asm/mcsafe_test.h>
+#include <asm/copy_mc_test.h>
+#include <asm/mce.h>
/*
* Generate an NFIT table to describe the following topology:
@@ -3283,7 +3284,7 @@ static struct platform_driver nfit_test_driver = {
.id_table = nfit_test_id,
};
-static char mcsafe_buf[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE)));
+static char copy_mc_buf[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE)));
enum INJECT {
INJECT_NONE,
@@ -3291,7 +3292,7 @@ enum INJECT {
INJECT_DST,
};
-static void mcsafe_test_init(char *dst, char *src, size_t size)
+static void copy_mc_test_init(char *dst, char *src, size_t size)
{
size_t i;
@@ -3300,7 +3301,7 @@ static void mcsafe_test_init(char *dst, char *src, size_t size)
src[i] = (char) i;
}
-static bool mcsafe_test_validate(unsigned char *dst, unsigned char *src,
+static bool copy_mc_test_validate(unsigned char *dst, unsigned char *src,
size_t size, unsigned long rem)
{
size_t i;
@@ -3321,12 +3322,12 @@ static bool mcsafe_test_validate(unsigned char *dst, unsigned char *src,
return true;
}
-void mcsafe_test(void)
+void copy_mc_test(void)
{
char *inject_desc[] = { "none", "source", "destination" };
enum INJECT inj;
- if (IS_ENABLED(CONFIG_MCSAFE_TEST)) {
+ if (IS_ENABLED(CONFIG_COPY_MC_TEST)) {
pr_info("%s: run...\n", __func__);
} else {
pr_info("%s: disabled, skip.\n", __func__);
@@ -3344,31 +3345,31 @@ void mcsafe_test(void)
switch (inj) {
case INJECT_NONE:
- mcsafe_inject_src(NULL);
- mcsafe_inject_dst(NULL);
- dst = &mcsafe_buf[2048];
- src = &mcsafe_buf[1024 - i];
+ copy_mc_inject_src(NULL);
+ copy_mc_inject_dst(NULL);
+ dst = ©_mc_buf[2048];
+ src = ©_mc_buf[1024 - i];
expect = 0;
break;
case INJECT_SRC:
- mcsafe_inject_src(&mcsafe_buf[1024]);
- mcsafe_inject_dst(NULL);
- dst = &mcsafe_buf[2048];
- src = &mcsafe_buf[1024 - i];
+ copy_mc_inject_src(©_mc_buf[1024]);
+ copy_mc_inject_dst(NULL);
+ dst = ©_mc_buf[2048];
+ src = ©_mc_buf[1024 - i];
expect = 512 - i;
break;
case INJECT_DST:
- mcsafe_inject_src(NULL);
- mcsafe_inject_dst(&mcsafe_buf[2048]);
- dst = &mcsafe_buf[2048 - i];
- src = &mcsafe_buf[1024];
+ copy_mc_inject_src(NULL);
+ copy_mc_inject_dst(©_mc_buf[2048]);
+ dst = ©_mc_buf[2048 - i];
+ src = ©_mc_buf[1024];
expect = 512 - i;
break;
}
- mcsafe_test_init(dst, src, 512);
- rem = __memcpy_mcsafe(dst, src, 512);
- valid = mcsafe_test_validate(dst, src, 512, expect);
+ copy_mc_test_init(dst, src, 512);
+ rem = copy_mc_fragile(dst, src, 512);
+ valid = copy_mc_test_validate(dst, src, 512, expect);
if (rem == expect && valid)
continue;
pr_info("%s: copy(%#lx, %#lx, %d) off: %d rem: %ld %s expect: %ld\n",
@@ -3380,8 +3381,8 @@ void mcsafe_test(void)
}
}
- mcsafe_inject_src(NULL);
- mcsafe_inject_dst(NULL);
+ copy_mc_inject_src(NULL);
+ copy_mc_inject_dst(NULL);
}
static __init int nfit_test_init(void)
@@ -3392,7 +3393,7 @@ static __init int nfit_test_init(void)
libnvdimm_test();
acpi_nfit_test();
device_dax_test();
- mcsafe_test();
+ copy_mc_test();
dax_pmem_test();
dax_pmem_core_test();
#ifdef CONFIG_DEV_DAX_PMEM_COMPAT
diff --git a/tools/testing/selftests/powerpc/copyloops/.gitignore b/tools/testing/selftests/powerpc/copyloops/.gitignore
index ddaf140b8255..994b11af765c 100644
--- a/tools/testing/selftests/powerpc/copyloops/.gitignore
+++ b/tools/testing/selftests/powerpc/copyloops/.gitignore
@@ -12,4 +12,4 @@ memcpy_p7_t1
copyuser_64_exc_t0
copyuser_64_exc_t1
copyuser_64_exc_t2
-memcpy_mcsafe_64
+copy_mc_64
diff --git a/tools/testing/selftests/powerpc/copyloops/Makefile b/tools/testing/selftests/powerpc/copyloops/Makefile
index 0917983a1c78..3095b1f1c02b 100644
--- a/tools/testing/selftests/powerpc/copyloops/Makefile
+++ b/tools/testing/selftests/powerpc/copyloops/Makefile
@@ -12,7 +12,7 @@ ASFLAGS = $(CFLAGS) -Wa,-mpower4
TEST_GEN_PROGS := copyuser_64_t0 copyuser_64_t1 copyuser_64_t2 \
copyuser_p7_t0 copyuser_p7_t1 \
memcpy_64_t0 memcpy_64_t1 memcpy_64_t2 \
- memcpy_p7_t0 memcpy_p7_t1 memcpy_mcsafe_64 \
+ memcpy_p7_t0 memcpy_p7_t1 copy_mc_64 \
copyuser_64_exc_t0 copyuser_64_exc_t1 copyuser_64_exc_t2
EXTRA_SOURCES := validate.c ../harness.c stubs.S
@@ -45,9 +45,9 @@ $(OUTPUT)/memcpy_p7_t%: memcpy_power7.S $(EXTRA_SOURCES)
-D SELFTEST_CASE=$(subst memcpy_p7_t,,$(notdir $@)) \
-o $@ $^
-$(OUTPUT)/memcpy_mcsafe_64: memcpy_mcsafe_64.S $(EXTRA_SOURCES)
+$(OUTPUT)/copy_mc_64: copy_mc_64.S $(EXTRA_SOURCES)
$(CC) $(CPPFLAGS) $(CFLAGS) \
- -D COPY_LOOP=test_memcpy_mcsafe \
+ -D COPY_LOOP=test_copy_mc_generic \
-o $@ $^
$(OUTPUT)/copyuser_64_exc_t%: copyuser_64.S exc_validate.c ../harness.c \
diff --git a/tools/testing/selftests/powerpc/copyloops/copy_mc_64.S b/tools/testing/selftests/powerpc/copyloops/copy_mc_64.S
new file mode 120000
index 000000000000..dcbe06d500fb
--- /dev/null
+++ b/tools/testing/selftests/powerpc/copyloops/copy_mc_64.S
@@ -0,0 +1 @@
+../../../../../arch/powerpc/lib/copy_mc_64.S
\ No newline at end of file
diff --git a/tools/testing/selftests/powerpc/copyloops/memcpy_mcsafe_64.S b/tools/testing/selftests/powerpc/copyloops/memcpy_mcsafe_64.S
deleted file mode 120000
index f0feef3062f6..000000000000
--- a/tools/testing/selftests/powerpc/copyloops/memcpy_mcsafe_64.S
+++ /dev/null
@@ -1 +0,0 @@
-../../../../../arch/powerpc/lib/memcpy_mcsafe_64.S
\ No newline at end of file
4 years, 3 months
- 1
- 0
FAILED: patch "[PATCH] x86, powerpc: Rename memcpy_mcsafe() to copy_mc_to_{user, " failed to apply to 4.19-stable tree
by gregkh＠linuxfoundation.org
The patch below does not apply to the 4.19-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From ec6347bb43395cb92126788a1a5b25302543f815 Mon Sep 17 00:00:00 2001
From: Dan Williams <dan.j.williams(a)intel.com>
Date: Mon, 5 Oct 2020 20:40:16 -0700
Subject: [PATCH] x86, powerpc: Rename memcpy_mcsafe() to copy_mc_to_{user,
kernel}()
In reaction to a proposal to introduce a memcpy_mcsafe_fast()
implementation Linus points out that memcpy_mcsafe() is poorly named
relative to communicating the scope of the interface. Specifically what
addresses are valid to pass as source, destination, and what faults /
exceptions are handled.
Of particular concern is that even though x86 might be able to handle
the semantics of copy_mc_to_user() with its common copy_user_generic()
implementation other archs likely need / want an explicit path for this
case:
On Fri, May 1, 2020 at 11:28 AM Linus Torvalds <torvalds(a)linux-foundation.org> wrote:
>
> On Thu, Apr 30, 2020 at 6:21 PM Dan Williams <dan.j.williams(a)intel.com> wrote:
> >
> > However now I see that copy_user_generic() works for the wrong reason.
> > It works because the exception on the source address due to poison
> > looks no different than a write fault on the user address to the
> > caller, it's still just a short copy. So it makes copy_to_user() work
> > for the wrong reason relative to the name.
>
> Right.
>
> And it won't work that way on other architectures. On x86, we have a
> generic function that can take faults on either side, and we use it
> for both cases (and for the "in_user" case too), but that's an
> artifact of the architecture oddity.
>
> In fact, it's probably wrong even on x86 - because it can hide bugs -
> but writing those things is painful enough that everybody prefers
> having just one function.
Replace a single top-level memcpy_mcsafe() with either
copy_mc_to_user(), or copy_mc_to_kernel().
Introduce an x86 copy_mc_fragile() name as the rename for the
low-level x86 implementation formerly named memcpy_mcsafe(). It is used
as the slow / careful backend that is supplanted by a fast
copy_mc_generic() in a follow-on patch.
One side-effect of this reorganization is that separating copy_mc_64.S
to its own file means that perf no longer needs to track dependencies
for its memcpy_64.S benchmarks.
[ bp: Massage a bit. ]
Signed-off-by: Dan Williams <dan.j.williams(a)intel.com>
Signed-off-by: Borislav Petkov <bp(a)suse.de>
Reviewed-by: Tony Luck <tony.luck(a)intel.com>
Acked-by: Michael Ellerman <mpe(a)ellerman.id.au>
Cc: <stable(a)vger.kernel.org>
Link: http://lore.kernel.org/r/CAHk-=wjSqtXAqfUJxFtWNwmguFASTgB0dz1dT3V-78Quiezqb…
Link: https://lkml.kernel.org/r/160195561680.2163339.11574962055305783722.stgit@d…
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 1f48bbfb3ce9..76473eda3426 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -136,7 +136,7 @@ config PPC
select ARCH_HAS_STRICT_KERNEL_RWX if (PPC32 && !HIBERNATION)
select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
select ARCH_HAS_UACCESS_FLUSHCACHE
- select ARCH_HAS_UACCESS_MCSAFE if PPC64
+ select ARCH_HAS_COPY_MC if PPC64
select ARCH_HAS_UBSAN_SANITIZE_ALL
select ARCH_HAVE_NMI_SAFE_CMPXCHG
select ARCH_KEEP_MEMBLOCK
diff --git a/arch/powerpc/include/asm/string.h b/arch/powerpc/include/asm/string.h
index 283552cd0e58..2aa0e31e6884 100644
--- a/arch/powerpc/include/asm/string.h
+++ b/arch/powerpc/include/asm/string.h
@@ -53,9 +53,7 @@ void *__memmove(void *to, const void *from, __kernel_size_t n);
#ifndef CONFIG_KASAN
#define __HAVE_ARCH_MEMSET32
#define __HAVE_ARCH_MEMSET64
-#define __HAVE_ARCH_MEMCPY_MCSAFE
-extern int memcpy_mcsafe(void *dst, const void *src, __kernel_size_t sz);
extern void *__memset16(uint16_t *, uint16_t v, __kernel_size_t);
extern void *__memset32(uint32_t *, uint32_t v, __kernel_size_t);
extern void *__memset64(uint64_t *, uint64_t v, __kernel_size_t);
diff --git a/arch/powerpc/include/asm/uaccess.h b/arch/powerpc/include/asm/uaccess.h
index 00699903f1ef..20a35373cafc 100644
--- a/arch/powerpc/include/asm/uaccess.h
+++ b/arch/powerpc/include/asm/uaccess.h
@@ -435,6 +435,32 @@ do { \
extern unsigned long __copy_tofrom_user(void __user *to,
const void __user *from, unsigned long size);
+#ifdef CONFIG_ARCH_HAS_COPY_MC
+unsigned long __must_check
+copy_mc_generic(void *to, const void *from, unsigned long size);
+
+static inline unsigned long __must_check
+copy_mc_to_kernel(void *to, const void *from, unsigned long size)
+{
+ return copy_mc_generic(to, from, size);
+}
+#define copy_mc_to_kernel copy_mc_to_kernel
+
+static inline unsigned long __must_check
+copy_mc_to_user(void __user *to, const void *from, unsigned long n)
+{
+ if (likely(check_copy_size(from, n, true))) {
+ if (access_ok(to, n)) {
+ allow_write_to_user(to, n);
+ n = copy_mc_generic((void *)to, from, n);
+ prevent_write_to_user(to, n);
+ }
+ }
+
+ return n;
+}
+#endif
+
#ifdef __powerpc64__
static inline unsigned long
raw_copy_in_user(void __user *to, const void __user *from, unsigned long n)
@@ -523,20 +549,6 @@ raw_copy_to_user(void __user *to, const void *from, unsigned long n)
return ret;
}
-static __always_inline unsigned long __must_check
-copy_to_user_mcsafe(void __user *to, const void *from, unsigned long n)
-{
- if (likely(check_copy_size(from, n, true))) {
- if (access_ok(to, n)) {
- allow_write_to_user(to, n);
- n = memcpy_mcsafe((void *)to, from, n);
- prevent_write_to_user(to, n);
- }
- }
-
- return n;
-}
-
unsigned long __arch_clear_user(void __user *addr, unsigned long size);
static inline unsigned long clear_user(void __user *addr, unsigned long size)
diff --git a/arch/powerpc/lib/Makefile b/arch/powerpc/lib/Makefile
index d66a645503eb..69a91b571845 100644
--- a/arch/powerpc/lib/Makefile
+++ b/arch/powerpc/lib/Makefile
@@ -39,7 +39,7 @@ obj-$(CONFIG_PPC_BOOK3S_64) += copyuser_power7.o copypage_power7.o \
memcpy_power7.o
obj64-y += copypage_64.o copyuser_64.o mem_64.o hweight_64.o \
- memcpy_64.o memcpy_mcsafe_64.o
+ memcpy_64.o copy_mc_64.o
ifndef CONFIG_PPC_QUEUED_SPINLOCKS
obj64-$(CONFIG_SMP) += locks.o
diff --git a/arch/powerpc/lib/memcpy_mcsafe_64.S b/arch/powerpc/lib/copy_mc_64.S
similarity index 98%
rename from arch/powerpc/lib/memcpy_mcsafe_64.S
rename to arch/powerpc/lib/copy_mc_64.S
index cb882d9a6d8a..88d46c471493 100644
--- a/arch/powerpc/lib/memcpy_mcsafe_64.S
+++ b/arch/powerpc/lib/copy_mc_64.S
@@ -50,7 +50,7 @@ err3; stb r0,0(r3)
blr
-_GLOBAL(memcpy_mcsafe)
+_GLOBAL(copy_mc_generic)
mr r7,r5
cmpldi r5,16
blt .Lshort_copy
@@ -239,4 +239,4 @@ err1; stb r0,0(r3)
15: li r3,0
blr
-EXPORT_SYMBOL_GPL(memcpy_mcsafe);
+EXPORT_SYMBOL_GPL(copy_mc_generic);
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 7101ac64bb20..e876b3a087f9 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -75,7 +75,7 @@ config X86
select ARCH_HAS_PTE_DEVMAP if X86_64
select ARCH_HAS_PTE_SPECIAL
select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64
- select ARCH_HAS_UACCESS_MCSAFE if X86_64 && X86_MCE
+ select ARCH_HAS_COPY_MC if X86_64
select ARCH_HAS_SET_MEMORY
select ARCH_HAS_SET_DIRECT_MAP
select ARCH_HAS_STRICT_KERNEL_RWX
diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug
index ee1d3c5834c6..27b5e2bc6a01 100644
--- a/arch/x86/Kconfig.debug
+++ b/arch/x86/Kconfig.debug
@@ -62,7 +62,7 @@ config EARLY_PRINTK_USB_XDBC
You should normally say N here, unless you want to debug early
crashes or need a very simple printk logging facility.
-config MCSAFE_TEST
+config COPY_MC_TEST
def_bool n
config EFI_PGT_DUMP
diff --git a/arch/x86/include/asm/copy_mc_test.h b/arch/x86/include/asm/copy_mc_test.h
new file mode 100644
index 000000000000..e4991ba96726
--- /dev/null
+++ b/arch/x86/include/asm/copy_mc_test.h
@@ -0,0 +1,75 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _COPY_MC_TEST_H_
+#define _COPY_MC_TEST_H_
+
+#ifndef __ASSEMBLY__
+#ifdef CONFIG_COPY_MC_TEST
+extern unsigned long copy_mc_test_src;
+extern unsigned long copy_mc_test_dst;
+
+static inline void copy_mc_inject_src(void *addr)
+{
+ if (addr)
+ copy_mc_test_src = (unsigned long) addr;
+ else
+ copy_mc_test_src = ~0UL;
+}
+
+static inline void copy_mc_inject_dst(void *addr)
+{
+ if (addr)
+ copy_mc_test_dst = (unsigned long) addr;
+ else
+ copy_mc_test_dst = ~0UL;
+}
+#else /* CONFIG_COPY_MC_TEST */
+static inline void copy_mc_inject_src(void *addr)
+{
+}
+
+static inline void copy_mc_inject_dst(void *addr)
+{
+}
+#endif /* CONFIG_COPY_MC_TEST */
+
+#else /* __ASSEMBLY__ */
+#include <asm/export.h>
+
+#ifdef CONFIG_COPY_MC_TEST
+.macro COPY_MC_TEST_CTL
+ .pushsection .data
+ .align 8
+ .globl copy_mc_test_src
+ copy_mc_test_src:
+ .quad 0
+ EXPORT_SYMBOL_GPL(copy_mc_test_src)
+ .globl copy_mc_test_dst
+ copy_mc_test_dst:
+ .quad 0
+ EXPORT_SYMBOL_GPL(copy_mc_test_dst)
+ .popsection
+.endm
+
+.macro COPY_MC_TEST_SRC reg count target
+ leaq \count(\reg), %r9
+ cmp copy_mc_test_src, %r9
+ ja \target
+.endm
+
+.macro COPY_MC_TEST_DST reg count target
+ leaq \count(\reg), %r9
+ cmp copy_mc_test_dst, %r9
+ ja \target
+.endm
+#else
+.macro COPY_MC_TEST_CTL
+.endm
+
+.macro COPY_MC_TEST_SRC reg count target
+.endm
+
+.macro COPY_MC_TEST_DST reg count target
+.endm
+#endif /* CONFIG_COPY_MC_TEST */
+#endif /* __ASSEMBLY__ */
+#endif /* _COPY_MC_TEST_H_ */
diff --git a/arch/x86/include/asm/mce.h b/arch/x86/include/asm/mce.h
index 109af5c7f515..ba2062d6df92 100644
--- a/arch/x86/include/asm/mce.h
+++ b/arch/x86/include/asm/mce.h
@@ -174,6 +174,15 @@ extern void mce_unregister_decode_chain(struct notifier_block *nb);
extern int mce_p5_enabled;
+#ifdef CONFIG_ARCH_HAS_COPY_MC
+extern void enable_copy_mc_fragile(void);
+unsigned long __must_check copy_mc_fragile(void *dst, const void *src, unsigned cnt);
+#else
+static inline void enable_copy_mc_fragile(void)
+{
+}
+#endif
+
#ifdef CONFIG_X86_MCE
int mcheck_init(void);
void mcheck_cpu_init(struct cpuinfo_x86 *c);
diff --git a/arch/x86/include/asm/mcsafe_test.h b/arch/x86/include/asm/mcsafe_test.h
deleted file mode 100644
index eb59804b6201..000000000000
--- a/arch/x86/include/asm/mcsafe_test.h
+++ /dev/null
@@ -1,75 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef _MCSAFE_TEST_H_
-#define _MCSAFE_TEST_H_
-
-#ifndef __ASSEMBLY__
-#ifdef CONFIG_MCSAFE_TEST
-extern unsigned long mcsafe_test_src;
-extern unsigned long mcsafe_test_dst;
-
-static inline void mcsafe_inject_src(void *addr)
-{
- if (addr)
- mcsafe_test_src = (unsigned long) addr;
- else
- mcsafe_test_src = ~0UL;
-}
-
-static inline void mcsafe_inject_dst(void *addr)
-{
- if (addr)
- mcsafe_test_dst = (unsigned long) addr;
- else
- mcsafe_test_dst = ~0UL;
-}
-#else /* CONFIG_MCSAFE_TEST */
-static inline void mcsafe_inject_src(void *addr)
-{
-}
-
-static inline void mcsafe_inject_dst(void *addr)
-{
-}
-#endif /* CONFIG_MCSAFE_TEST */
-
-#else /* __ASSEMBLY__ */
-#include <asm/export.h>
-
-#ifdef CONFIG_MCSAFE_TEST
-.macro MCSAFE_TEST_CTL
- .pushsection .data
- .align 8
- .globl mcsafe_test_src
- mcsafe_test_src:
- .quad 0
- EXPORT_SYMBOL_GPL(mcsafe_test_src)
- .globl mcsafe_test_dst
- mcsafe_test_dst:
- .quad 0
- EXPORT_SYMBOL_GPL(mcsafe_test_dst)
- .popsection
-.endm
-
-.macro MCSAFE_TEST_SRC reg count target
- leaq \count(\reg), %r9
- cmp mcsafe_test_src, %r9
- ja \target
-.endm
-
-.macro MCSAFE_TEST_DST reg count target
- leaq \count(\reg), %r9
- cmp mcsafe_test_dst, %r9
- ja \target
-.endm
-#else
-.macro MCSAFE_TEST_CTL
-.endm
-
-.macro MCSAFE_TEST_SRC reg count target
-.endm
-
-.macro MCSAFE_TEST_DST reg count target
-.endm
-#endif /* CONFIG_MCSAFE_TEST */
-#endif /* __ASSEMBLY__ */
-#endif /* _MCSAFE_TEST_H_ */
diff --git a/arch/x86/include/asm/string_64.h b/arch/x86/include/asm/string_64.h
index 75314c3dbe47..6e450827f677 100644
--- a/arch/x86/include/asm/string_64.h
+++ b/arch/x86/include/asm/string_64.h
@@ -82,38 +82,6 @@ int strcmp(const char *cs, const char *ct);
#endif
-#define __HAVE_ARCH_MEMCPY_MCSAFE 1
-__must_check unsigned long __memcpy_mcsafe(void *dst, const void *src,
- size_t cnt);
-DECLARE_STATIC_KEY_FALSE(mcsafe_key);
-
-/**
- * memcpy_mcsafe - copy memory with indication if a machine check happened
- *
- * @dst: destination address
- * @src: source address
- * @cnt: number of bytes to copy
- *
- * Low level memory copy function that catches machine checks
- * We only call into the "safe" function on systems that can
- * actually do machine check recovery. Everyone else can just
- * use memcpy().
- *
- * Return 0 for success, or number of bytes not copied if there was an
- * exception.
- */
-static __always_inline __must_check unsigned long
-memcpy_mcsafe(void *dst, const void *src, size_t cnt)
-{
-#ifdef CONFIG_X86_MCE
- if (static_branch_unlikely(&mcsafe_key))
- return __memcpy_mcsafe(dst, src, cnt);
- else
-#endif
- memcpy(dst, src, cnt);
- return 0;
-}
-
#ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE
#define __HAVE_ARCH_MEMCPY_FLUSHCACHE 1
void __memcpy_flushcache(void *dst, const void *src, size_t cnt);
diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h
index ecefaffd15d4..eff7fb847149 100644
--- a/arch/x86/include/asm/uaccess.h
+++ b/arch/x86/include/asm/uaccess.h
@@ -455,6 +455,15 @@ extern __must_check long strnlen_user(const char __user *str, long n);
unsigned long __must_check clear_user(void __user *mem, unsigned long len);
unsigned long __must_check __clear_user(void __user *mem, unsigned long len);
+#ifdef CONFIG_ARCH_HAS_COPY_MC
+unsigned long __must_check
+copy_mc_to_kernel(void *to, const void *from, unsigned len);
+#define copy_mc_to_kernel copy_mc_to_kernel
+
+unsigned long __must_check
+copy_mc_to_user(void *to, const void *from, unsigned len);
+#endif
+
/*
* movsl can be slow when source and dest are not both 8-byte aligned
*/
diff --git a/arch/x86/include/asm/uaccess_64.h b/arch/x86/include/asm/uaccess_64.h
index bc10e3dc64fe..e7265a552f4f 100644
--- a/arch/x86/include/asm/uaccess_64.h
+++ b/arch/x86/include/asm/uaccess_64.h
@@ -46,22 +46,6 @@ copy_user_generic(void *to, const void *from, unsigned len)
return ret;
}
-static __always_inline __must_check unsigned long
-copy_to_user_mcsafe(void *to, const void *from, unsigned len)
-{
- unsigned long ret;
-
- __uaccess_begin();
- /*
- * Note, __memcpy_mcsafe() is explicitly used since it can
- * handle exceptions / faults. memcpy_mcsafe() may fall back to
- * memcpy() which lacks this handling.
- */
- ret = __memcpy_mcsafe(to, from, len);
- __uaccess_end();
- return ret;
-}
-
static __always_inline __must_check unsigned long
raw_copy_from_user(void *dst, const void __user *src, unsigned long size)
{
@@ -102,8 +86,4 @@ __copy_from_user_flushcache(void *dst, const void __user *src, unsigned size)
kasan_check_write(dst, size);
return __copy_user_flushcache(dst, src, size);
}
-
-unsigned long
-mcsafe_handle_tail(char *to, char *from, unsigned len);
-
#endif /* _ASM_X86_UACCESS_64_H */
diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c
index 11b6697be010..b5b70f4b351d 100644
--- a/arch/x86/kernel/cpu/mce/core.c
+++ b/arch/x86/kernel/cpu/mce/core.c
@@ -40,7 +40,6 @@
#include <linux/debugfs.h>
#include <linux/irq_work.h>
#include <linux/export.h>
-#include <linux/jump_label.h>
#include <linux/set_memory.h>
#include <linux/sync_core.h>
#include <linux/task_work.h>
@@ -2124,7 +2123,7 @@ void mce_disable_bank(int bank)
and older.
* mce=nobootlog Don't log MCEs from before booting.
* mce=bios_cmci_threshold Don't program the CMCI threshold
- * mce=recovery force enable memcpy_mcsafe()
+ * mce=recovery force enable copy_mc_fragile()
*/
static int __init mcheck_enable(char *str)
{
@@ -2732,13 +2731,10 @@ static void __init mcheck_debugfs_init(void)
static void __init mcheck_debugfs_init(void) { }
#endif
-DEFINE_STATIC_KEY_FALSE(mcsafe_key);
-EXPORT_SYMBOL_GPL(mcsafe_key);
-
static int __init mcheck_late_init(void)
{
if (mca_cfg.recovery)
- static_branch_inc(&mcsafe_key);
+ enable_copy_mc_fragile();
mcheck_debugfs_init();
diff --git a/arch/x86/kernel/quirks.c b/arch/x86/kernel/quirks.c
index 1b10717c9321..6d0df6a58873 100644
--- a/arch/x86/kernel/quirks.c
+++ b/arch/x86/kernel/quirks.c
@@ -8,6 +8,7 @@
#include <asm/hpet.h>
#include <asm/setup.h>
+#include <asm/mce.h>
#if defined(CONFIG_X86_IO_APIC) && defined(CONFIG_SMP) && defined(CONFIG_PCI)
@@ -624,10 +625,6 @@ static void amd_disable_seq_and_redirect_scrub(struct pci_dev *dev)
DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_16H_NB_F3,
amd_disable_seq_and_redirect_scrub);
-#if defined(CONFIG_X86_64) && defined(CONFIG_X86_MCE)
-#include <linux/jump_label.h>
-#include <asm/string_64.h>
-
/* Ivy Bridge, Haswell, Broadwell */
static void quirk_intel_brickland_xeon_ras_cap(struct pci_dev *pdev)
{
@@ -636,7 +633,7 @@ static void quirk_intel_brickland_xeon_ras_cap(struct pci_dev *pdev)
pci_read_config_dword(pdev, 0x84, &capid0);
if (capid0 & 0x10)
- static_branch_inc(&mcsafe_key);
+ enable_copy_mc_fragile();
}
/* Skylake */
@@ -653,7 +650,7 @@ static void quirk_intel_purley_xeon_ras_cap(struct pci_dev *pdev)
* enabled, so memory machine check recovery is also enabled.
*/
if ((capid0 & 0xc0) == 0xc0 || (capid5 & 0x1e0))
- static_branch_inc(&mcsafe_key);
+ enable_copy_mc_fragile();
}
DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x0ec3, quirk_intel_brickland_xeon_ras_cap);
@@ -661,7 +658,6 @@ DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x2fc0, quirk_intel_brickland_xeon_
DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x6fc0, quirk_intel_brickland_xeon_ras_cap);
DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x2083, quirk_intel_purley_xeon_ras_cap);
#endif
-#endif
bool x86_apple_machine;
EXPORT_SYMBOL(x86_apple_machine);
diff --git a/arch/x86/lib/Makefile b/arch/x86/lib/Makefile
index d46fff11f06f..f7d23c9c22b2 100644
--- a/arch/x86/lib/Makefile
+++ b/arch/x86/lib/Makefile
@@ -44,6 +44,7 @@ obj-$(CONFIG_SMP) += msr-smp.o cache-smp.o
lib-y := delay.o misc.o cmdline.o cpu.o
lib-y += usercopy_$(BITS).o usercopy.o getuser.o putuser.o
lib-y += memcpy_$(BITS).o
+lib-$(CONFIG_ARCH_HAS_COPY_MC) += copy_mc.o copy_mc_64.o
lib-$(CONFIG_INSTRUCTION_DECODER) += insn.o inat.o insn-eval.o
lib-$(CONFIG_RANDOMIZE_BASE) += kaslr.o
lib-$(CONFIG_FUNCTION_ERROR_INJECTION) += error-inject.o
diff --git a/arch/x86/lib/copy_mc.c b/arch/x86/lib/copy_mc.c
new file mode 100644
index 000000000000..2633635530b7
--- /dev/null
+++ b/arch/x86/lib/copy_mc.c
@@ -0,0 +1,82 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright(c) 2016-2020 Intel Corporation. All rights reserved. */
+
+#include <linux/jump_label.h>
+#include <linux/uaccess.h>
+#include <linux/export.h>
+#include <linux/string.h>
+#include <linux/types.h>
+
+#include <asm/mce.h>
+
+#ifdef CONFIG_X86_MCE
+/*
+ * See COPY_MC_TEST for self-test of the copy_mc_fragile()
+ * implementation.
+ */
+static DEFINE_STATIC_KEY_FALSE(copy_mc_fragile_key);
+
+void enable_copy_mc_fragile(void)
+{
+ static_branch_inc(©_mc_fragile_key);
+}
+#define copy_mc_fragile_enabled (static_branch_unlikely(©_mc_fragile_key))
+
+/*
+ * Similar to copy_user_handle_tail, probe for the write fault point, or
+ * source exception point.
+ */
+__visible notrace unsigned long
+copy_mc_fragile_handle_tail(char *to, char *from, unsigned len)
+{
+ for (; len; --len, to++, from++)
+ if (copy_mc_fragile(to, from, 1))
+ break;
+ return len;
+}
+#else
+/*
+ * No point in doing careful copying, or consulting a static key when
+ * there is no #MC handler in the CONFIG_X86_MCE=n case.
+ */
+void enable_copy_mc_fragile(void)
+{
+}
+#define copy_mc_fragile_enabled (0)
+#endif
+
+/**
+ * copy_mc_to_kernel - memory copy that handles source exceptions
+ *
+ * @dst: destination address
+ * @src: source address
+ * @len: number of bytes to copy
+ *
+ * Call into the 'fragile' version on systems that have trouble
+ * actually do machine check recovery. Everyone else can just
+ * use memcpy().
+ *
+ * Return 0 for success, or number of bytes not copied if there was an
+ * exception.
+ */
+unsigned long __must_check copy_mc_to_kernel(void *dst, const void *src, unsigned len)
+{
+ if (copy_mc_fragile_enabled)
+ return copy_mc_fragile(dst, src, len);
+ memcpy(dst, src, len);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(copy_mc_to_kernel);
+
+unsigned long __must_check copy_mc_to_user(void *dst, const void *src, unsigned len)
+{
+ unsigned long ret;
+
+ if (!copy_mc_fragile_enabled)
+ return copy_user_generic(dst, src, len);
+
+ __uaccess_begin();
+ ret = copy_mc_fragile(dst, src, len);
+ __uaccess_end();
+ return ret;
+}
diff --git a/arch/x86/lib/copy_mc_64.S b/arch/x86/lib/copy_mc_64.S
new file mode 100644
index 000000000000..c3b613c4544a
--- /dev/null
+++ b/arch/x86/lib/copy_mc_64.S
@@ -0,0 +1,127 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* Copyright(c) 2016-2020 Intel Corporation. All rights reserved. */
+
+#include <linux/linkage.h>
+#include <asm/copy_mc_test.h>
+#include <asm/export.h>
+#include <asm/asm.h>
+
+#ifndef CONFIG_UML
+
+#ifdef CONFIG_X86_MCE
+COPY_MC_TEST_CTL
+
+/*
+ * copy_mc_fragile - copy memory with indication if an exception / fault happened
+ *
+ * The 'fragile' version is opted into by platform quirks and takes
+ * pains to avoid unrecoverable corner cases like 'fast-string'
+ * instruction sequences, and consuming poison across a cacheline
+ * boundary. The non-fragile version is equivalent to memcpy()
+ * regardless of CPU machine-check-recovery capability.
+ */
+SYM_FUNC_START(copy_mc_fragile)
+ cmpl $8, %edx
+ /* Less than 8 bytes? Go to byte copy loop */
+ jb .L_no_whole_words
+
+ /* Check for bad alignment of source */
+ testl $7, %esi
+ /* Already aligned */
+ jz .L_8byte_aligned
+
+ /* Copy one byte at a time until source is 8-byte aligned */
+ movl %esi, %ecx
+ andl $7, %ecx
+ subl $8, %ecx
+ negl %ecx
+ subl %ecx, %edx
+.L_read_leading_bytes:
+ movb (%rsi), %al
+ COPY_MC_TEST_SRC %rsi 1 .E_leading_bytes
+ COPY_MC_TEST_DST %rdi 1 .E_leading_bytes
+.L_write_leading_bytes:
+ movb %al, (%rdi)
+ incq %rsi
+ incq %rdi
+ decl %ecx
+ jnz .L_read_leading_bytes
+
+.L_8byte_aligned:
+ movl %edx, %ecx
+ andl $7, %edx
+ shrl $3, %ecx
+ jz .L_no_whole_words
+
+.L_read_words:
+ movq (%rsi), %r8
+ COPY_MC_TEST_SRC %rsi 8 .E_read_words
+ COPY_MC_TEST_DST %rdi 8 .E_write_words
+.L_write_words:
+ movq %r8, (%rdi)
+ addq $8, %rsi
+ addq $8, %rdi
+ decl %ecx
+ jnz .L_read_words
+
+ /* Any trailing bytes? */
+.L_no_whole_words:
+ andl %edx, %edx
+ jz .L_done_memcpy_trap
+
+ /* Copy trailing bytes */
+ movl %edx, %ecx
+.L_read_trailing_bytes:
+ movb (%rsi), %al
+ COPY_MC_TEST_SRC %rsi 1 .E_trailing_bytes
+ COPY_MC_TEST_DST %rdi 1 .E_trailing_bytes
+.L_write_trailing_bytes:
+ movb %al, (%rdi)
+ incq %rsi
+ incq %rdi
+ decl %ecx
+ jnz .L_read_trailing_bytes
+
+ /* Copy successful. Return zero */
+.L_done_memcpy_trap:
+ xorl %eax, %eax
+.L_done:
+ ret
+SYM_FUNC_END(copy_mc_fragile)
+EXPORT_SYMBOL_GPL(copy_mc_fragile)
+
+ .section .fixup, "ax"
+ /*
+ * Return number of bytes not copied for any failure. Note that
+ * there is no "tail" handling since the source buffer is 8-byte
+ * aligned and poison is cacheline aligned.
+ */
+.E_read_words:
+ shll $3, %ecx
+.E_leading_bytes:
+ addl %edx, %ecx
+.E_trailing_bytes:
+ mov %ecx, %eax
+ jmp .L_done
+
+ /*
+ * For write fault handling, given the destination is unaligned,
+ * we handle faults on multi-byte writes with a byte-by-byte
+ * copy up to the write-protected page.
+ */
+.E_write_words:
+ shll $3, %ecx
+ addl %edx, %ecx
+ movl %ecx, %edx
+ jmp copy_mc_fragile_handle_tail
+
+ .previous
+
+ _ASM_EXTABLE_FAULT(.L_read_leading_bytes, .E_leading_bytes)
+ _ASM_EXTABLE_FAULT(.L_read_words, .E_read_words)
+ _ASM_EXTABLE_FAULT(.L_read_trailing_bytes, .E_trailing_bytes)
+ _ASM_EXTABLE(.L_write_leading_bytes, .E_leading_bytes)
+ _ASM_EXTABLE(.L_write_words, .E_write_words)
+ _ASM_EXTABLE(.L_write_trailing_bytes, .E_trailing_bytes)
+#endif /* CONFIG_X86_MCE */
+#endif /* !CONFIG_UML */
diff --git a/arch/x86/lib/memcpy_64.S b/arch/x86/lib/memcpy_64.S
index bbcc05bcefad..037faac46b0c 100644
--- a/arch/x86/lib/memcpy_64.S
+++ b/arch/x86/lib/memcpy_64.S
@@ -4,7 +4,6 @@
#include <linux/linkage.h>
#include <asm/errno.h>
#include <asm/cpufeatures.h>
-#include <asm/mcsafe_test.h>
#include <asm/alternative-asm.h>
#include <asm/export.h>
@@ -187,117 +186,3 @@ SYM_FUNC_START_LOCAL(memcpy_orig)
SYM_FUNC_END(memcpy_orig)
.popsection
-
-#ifndef CONFIG_UML
-
-MCSAFE_TEST_CTL
-
-/*
- * __memcpy_mcsafe - memory copy with machine check exception handling
- * Note that we only catch machine checks when reading the source addresses.
- * Writes to target are posted and don't generate machine checks.
- */
-SYM_FUNC_START(__memcpy_mcsafe)
- cmpl $8, %edx
- /* Less than 8 bytes? Go to byte copy loop */
- jb .L_no_whole_words
-
- /* Check for bad alignment of source */
- testl $7, %esi
- /* Already aligned */
- jz .L_8byte_aligned
-
- /* Copy one byte at a time until source is 8-byte aligned */
- movl %esi, %ecx
- andl $7, %ecx
- subl $8, %ecx
- negl %ecx
- subl %ecx, %edx
-.L_read_leading_bytes:
- movb (%rsi), %al
- MCSAFE_TEST_SRC %rsi 1 .E_leading_bytes
- MCSAFE_TEST_DST %rdi 1 .E_leading_bytes
-.L_write_leading_bytes:
- movb %al, (%rdi)
- incq %rsi
- incq %rdi
- decl %ecx
- jnz .L_read_leading_bytes
-
-.L_8byte_aligned:
- movl %edx, %ecx
- andl $7, %edx
- shrl $3, %ecx
- jz .L_no_whole_words
-
-.L_read_words:
- movq (%rsi), %r8
- MCSAFE_TEST_SRC %rsi 8 .E_read_words
- MCSAFE_TEST_DST %rdi 8 .E_write_words
-.L_write_words:
- movq %r8, (%rdi)
- addq $8, %rsi
- addq $8, %rdi
- decl %ecx
- jnz .L_read_words
-
- /* Any trailing bytes? */
-.L_no_whole_words:
- andl %edx, %edx
- jz .L_done_memcpy_trap
-
- /* Copy trailing bytes */
- movl %edx, %ecx
-.L_read_trailing_bytes:
- movb (%rsi), %al
- MCSAFE_TEST_SRC %rsi 1 .E_trailing_bytes
- MCSAFE_TEST_DST %rdi 1 .E_trailing_bytes
-.L_write_trailing_bytes:
- movb %al, (%rdi)
- incq %rsi
- incq %rdi
- decl %ecx
- jnz .L_read_trailing_bytes
-
- /* Copy successful. Return zero */
-.L_done_memcpy_trap:
- xorl %eax, %eax
-.L_done:
- ret
-SYM_FUNC_END(__memcpy_mcsafe)
-EXPORT_SYMBOL_GPL(__memcpy_mcsafe)
-
- .section .fixup, "ax"
- /*
- * Return number of bytes not copied for any failure. Note that
- * there is no "tail" handling since the source buffer is 8-byte
- * aligned and poison is cacheline aligned.
- */
-.E_read_words:
- shll $3, %ecx
-.E_leading_bytes:
- addl %edx, %ecx
-.E_trailing_bytes:
- mov %ecx, %eax
- jmp .L_done
-
- /*
- * For write fault handling, given the destination is unaligned,
- * we handle faults on multi-byte writes with a byte-by-byte
- * copy up to the write-protected page.
- */
-.E_write_words:
- shll $3, %ecx
- addl %edx, %ecx
- movl %ecx, %edx
- jmp mcsafe_handle_tail
-
- .previous
-
- _ASM_EXTABLE_FAULT(.L_read_leading_bytes, .E_leading_bytes)
- _ASM_EXTABLE_FAULT(.L_read_words, .E_read_words)
- _ASM_EXTABLE_FAULT(.L_read_trailing_bytes, .E_trailing_bytes)
- _ASM_EXTABLE(.L_write_leading_bytes, .E_leading_bytes)
- _ASM_EXTABLE(.L_write_words, .E_write_words)
- _ASM_EXTABLE(.L_write_trailing_bytes, .E_trailing_bytes)
-#endif
diff --git a/arch/x86/lib/usercopy_64.c b/arch/x86/lib/usercopy_64.c
index b0dfac3d3df7..5f1d4a9ebd5a 100644
--- a/arch/x86/lib/usercopy_64.c
+++ b/arch/x86/lib/usercopy_64.c
@@ -56,27 +56,6 @@ unsigned long clear_user(void __user *to, unsigned long n)
}
EXPORT_SYMBOL(clear_user);
-/*
- * Similar to copy_user_handle_tail, probe for the write fault point,
- * but reuse __memcpy_mcsafe in case a new read error is encountered.
- * clac() is handled in _copy_to_iter_mcsafe().
- */
-__visible notrace unsigned long
-mcsafe_handle_tail(char *to, char *from, unsigned len)
-{
- for (; len; --len, to++, from++) {
- /*
- * Call the assembly routine back directly since
- * memcpy_mcsafe() may silently fallback to memcpy.
- */
- unsigned long rem = __memcpy_mcsafe(to, from, 1);
-
- if (rem)
- break;
- }
- return len;
-}
-
#ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE
/**
* clean_cache_range - write back a cache range with CLWB
diff --git a/drivers/md/dm-writecache.c b/drivers/md/dm-writecache.c
index 86dbe0c8b45c..9fc18fadacc6 100644
--- a/drivers/md/dm-writecache.c
+++ b/drivers/md/dm-writecache.c
@@ -49,7 +49,7 @@ do { \
#define pmem_assign(dest, src) ((dest) = (src))
#endif
-#if defined(__HAVE_ARCH_MEMCPY_MCSAFE) && defined(DM_WRITECACHE_HAS_PMEM)
+#if IS_ENABLED(CONFIG_ARCH_HAS_COPY_MC) && defined(DM_WRITECACHE_HAS_PMEM)
#define DM_WRITECACHE_HANDLE_HARDWARE_ERRORS
#endif
@@ -984,7 +984,8 @@ static void writecache_resume(struct dm_target *ti)
}
wc->freelist_size = 0;
- r = memcpy_mcsafe(&sb_seq_count, &sb(wc)->seq_count, sizeof(uint64_t));
+ r = copy_mc_to_kernel(&sb_seq_count, &sb(wc)->seq_count,
+ sizeof(uint64_t));
if (r) {
writecache_error(wc, r, "hardware memory error when reading superblock: %d", r);
sb_seq_count = cpu_to_le64(0);
@@ -1000,7 +1001,8 @@ static void writecache_resume(struct dm_target *ti)
e->seq_count = -1;
continue;
}
- r = memcpy_mcsafe(&wme, memory_entry(wc, e), sizeof(struct wc_memory_entry));
+ r = copy_mc_to_kernel(&wme, memory_entry(wc, e),
+ sizeof(struct wc_memory_entry));
if (r) {
writecache_error(wc, r, "hardware memory error when reading metadata entry %lu: %d",
(unsigned long)b, r);
@@ -1198,7 +1200,7 @@ static void bio_copy_block(struct dm_writecache *wc, struct bio *bio, void *data
if (rw == READ) {
int r;
- r = memcpy_mcsafe(buf, data, size);
+ r = copy_mc_to_kernel(buf, data, size);
flush_dcache_page(bio_page(bio));
if (unlikely(r)) {
writecache_error(wc, r, "hardware memory error when reading data: %d", r);
@@ -2341,7 +2343,7 @@ static int writecache_ctr(struct dm_target *ti, unsigned argc, char **argv)
}
}
- r = memcpy_mcsafe(&s, sb(wc), sizeof(struct wc_memory_superblock));
+ r = copy_mc_to_kernel(&s, sb(wc), sizeof(struct wc_memory_superblock));
if (r) {
ti->error = "Hardware memory error when reading superblock";
goto bad;
@@ -2352,7 +2354,8 @@ static int writecache_ctr(struct dm_target *ti, unsigned argc, char **argv)
ti->error = "Unable to initialize device";
goto bad;
}
- r = memcpy_mcsafe(&s, sb(wc), sizeof(struct wc_memory_superblock));
+ r = copy_mc_to_kernel(&s, sb(wc),
+ sizeof(struct wc_memory_superblock));
if (r) {
ti->error = "Hardware memory error when reading superblock";
goto bad;
diff --git a/drivers/nvdimm/claim.c b/drivers/nvdimm/claim.c
index 45964acba944..22d865ba6353 100644
--- a/drivers/nvdimm/claim.c
+++ b/drivers/nvdimm/claim.c
@@ -268,7 +268,7 @@ static int nsio_rw_bytes(struct nd_namespace_common *ndns,
if (rw == READ) {
if (unlikely(is_bad_pmem(&nsio->bb, sector, sz_align)))
return -EIO;
- if (memcpy_mcsafe(buf, nsio->addr + offset, size) != 0)
+ if (copy_mc_to_kernel(buf, nsio->addr + offset, size) != 0)
return -EIO;
return 0;
}
diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index fab29b514372..5c6939e004e2 100644
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c
@@ -125,7 +125,7 @@ static blk_status_t read_pmem(struct page *page, unsigned int off,
while (len) {
mem = kmap_atomic(page);
chunk = min_t(unsigned int, len, PAGE_SIZE - off);
- rem = memcpy_mcsafe(mem + off, pmem_addr, chunk);
+ rem = copy_mc_to_kernel(mem + off, pmem_addr, chunk);
kunmap_atomic(mem);
if (rem)
return BLK_STS_IOERR;
@@ -304,7 +304,7 @@ static long pmem_dax_direct_access(struct dax_device *dax_dev,
/*
* Use the 'no check' versions of copy_from_iter_flushcache() and
- * copy_to_iter_mcsafe() to bypass HARDENED_USERCOPY overhead. Bounds
+ * copy_mc_to_iter() to bypass HARDENED_USERCOPY overhead. Bounds
* checking, both file offset and device offset, is handled by
* dax_iomap_actor()
*/
@@ -317,7 +317,7 @@ static size_t pmem_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff,
static size_t pmem_copy_to_iter(struct dax_device *dax_dev, pgoff_t pgoff,
void *addr, size_t bytes, struct iov_iter *i)
{
- return _copy_to_iter_mcsafe(addr, bytes, i);
+ return _copy_mc_to_iter(addr, bytes, i);
}
static const struct dax_operations pmem_dax_ops = {
diff --git a/include/linux/string.h b/include/linux/string.h
index 9b7a0632e87a..b1f3894a0a3e 100644
--- a/include/linux/string.h
+++ b/include/linux/string.h
@@ -161,20 +161,13 @@ extern int bcmp(const void *,const void *,__kernel_size_t);
#ifndef __HAVE_ARCH_MEMCHR
extern void * memchr(const void *,int,__kernel_size_t);
#endif
-#ifndef __HAVE_ARCH_MEMCPY_MCSAFE
-static inline __must_check unsigned long memcpy_mcsafe(void *dst,
- const void *src, size_t cnt)
-{
- memcpy(dst, src, cnt);
- return 0;
-}
-#endif
#ifndef __HAVE_ARCH_MEMCPY_FLUSHCACHE
static inline void memcpy_flushcache(void *dst, const void *src, size_t cnt)
{
memcpy(dst, src, cnt);
}
#endif
+
void *memchr_inv(const void *s, int c, size_t n);
char *strreplace(char *s, char old, char new);
diff --git a/include/linux/uaccess.h b/include/linux/uaccess.h
index 94b285411659..1ae36bc8db35 100644
--- a/include/linux/uaccess.h
+++ b/include/linux/uaccess.h
@@ -179,6 +179,19 @@ copy_in_user(void __user *to, const void __user *from, unsigned long n)
}
#endif
+#ifndef copy_mc_to_kernel
+/*
+ * Without arch opt-in this generic copy_mc_to_kernel() will not handle
+ * #MC (or arch equivalent) during source read.
+ */
+static inline unsigned long __must_check
+copy_mc_to_kernel(void *dst, const void *src, size_t cnt)
+{
+ memcpy(dst, src, cnt);
+ return 0;
+}
+#endif
+
static __always_inline void pagefault_disabled_inc(void)
{
current->pagefault_disabled++;
diff --git a/include/linux/uio.h b/include/linux/uio.h
index 3835a8a8e9ea..f14410c678bd 100644
--- a/include/linux/uio.h
+++ b/include/linux/uio.h
@@ -185,10 +185,10 @@ size_t _copy_from_iter_flushcache(void *addr, size_t bytes, struct iov_iter *i);
#define _copy_from_iter_flushcache _copy_from_iter_nocache
#endif
-#ifdef CONFIG_ARCH_HAS_UACCESS_MCSAFE
-size_t _copy_to_iter_mcsafe(const void *addr, size_t bytes, struct iov_iter *i);
+#ifdef CONFIG_ARCH_HAS_COPY_MC
+size_t _copy_mc_to_iter(const void *addr, size_t bytes, struct iov_iter *i);
#else
-#define _copy_to_iter_mcsafe _copy_to_iter
+#define _copy_mc_to_iter _copy_to_iter
#endif
static __always_inline __must_check
@@ -201,12 +201,12 @@ size_t copy_from_iter_flushcache(void *addr, size_t bytes, struct iov_iter *i)
}
static __always_inline __must_check
-size_t copy_to_iter_mcsafe(void *addr, size_t bytes, struct iov_iter *i)
+size_t copy_mc_to_iter(void *addr, size_t bytes, struct iov_iter *i)
{
if (unlikely(!check_copy_size(addr, bytes, true)))
return 0;
else
- return _copy_to_iter_mcsafe(addr, bytes, i);
+ return _copy_mc_to_iter(addr, bytes, i);
}
size_t iov_iter_zero(size_t bytes, struct iov_iter *);
diff --git a/lib/Kconfig b/lib/Kconfig
index b4b98a03ff98..b46a9fd122c8 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -635,7 +635,12 @@ config UACCESS_MEMCPY
config ARCH_HAS_UACCESS_FLUSHCACHE
bool
-config ARCH_HAS_UACCESS_MCSAFE
+# arch has a concept of a recoverable synchronous exception due to a
+# memory-read error like x86 machine-check or ARM data-abort, and
+# implements copy_mc_to_{user,kernel} to abort and report
+# 'bytes-transferred' if that exception fires when accessing the source
+# buffer.
+config ARCH_HAS_COPY_MC
bool
# Temporary. Goes away when all archs are cleaned up
diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index 5e40786c8f12..d13304a034f5 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -637,30 +637,30 @@ size_t _copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i)
}
EXPORT_SYMBOL(_copy_to_iter);
-#ifdef CONFIG_ARCH_HAS_UACCESS_MCSAFE
-static int copyout_mcsafe(void __user *to, const void *from, size_t n)
+#ifdef CONFIG_ARCH_HAS_COPY_MC
+static int copyout_mc(void __user *to, const void *from, size_t n)
{
if (access_ok(to, n)) {
instrument_copy_to_user(to, from, n);
- n = copy_to_user_mcsafe((__force void *) to, from, n);
+ n = copy_mc_to_user((__force void *) to, from, n);
}
return n;
}
-static unsigned long memcpy_mcsafe_to_page(struct page *page, size_t offset,
+static unsigned long copy_mc_to_page(struct page *page, size_t offset,
const char *from, size_t len)
{
unsigned long ret;
char *to;
to = kmap_atomic(page);
- ret = memcpy_mcsafe(to + offset, from, len);
+ ret = copy_mc_to_kernel(to + offset, from, len);
kunmap_atomic(to);
return ret;
}
-static size_t copy_pipe_to_iter_mcsafe(const void *addr, size_t bytes,
+static size_t copy_mc_pipe_to_iter(const void *addr, size_t bytes,
struct iov_iter *i)
{
struct pipe_inode_info *pipe = i->pipe;
@@ -678,7 +678,7 @@ static size_t copy_pipe_to_iter_mcsafe(const void *addr, size_t bytes,
size_t chunk = min_t(size_t, n, PAGE_SIZE - off);
unsigned long rem;
- rem = memcpy_mcsafe_to_page(pipe->bufs[i_head & p_mask].page,
+ rem = copy_mc_to_page(pipe->bufs[i_head & p_mask].page,
off, addr, chunk);
i->head = i_head;
i->iov_offset = off + chunk - rem;
@@ -695,18 +695,17 @@ static size_t copy_pipe_to_iter_mcsafe(const void *addr, size_t bytes,
}
/**
- * _copy_to_iter_mcsafe - copy to user with source-read error exception handling
+ * _copy_mc_to_iter - copy to iter with source memory error exception handling
* @addr: source kernel address
* @bytes: total transfer length
* @iter: destination iterator
*
- * The pmem driver arranges for filesystem-dax to use this facility via
- * dax_copy_to_iter() for protecting read/write to persistent memory.
- * Unless / until an architecture can guarantee identical performance
- * between _copy_to_iter_mcsafe() and _copy_to_iter() it would be a
- * performance regression to switch more users to the mcsafe version.
+ * The pmem driver deploys this for the dax operation
+ * (dax_copy_to_iter()) for dax reads (bypass page-cache and the
+ * block-layer). Upon #MC read(2) aborts and returns EIO or the bytes
+ * successfully copied.
*
- * Otherwise, the main differences between this and typical _copy_to_iter().
+ * The main differences between this and typical _copy_to_iter().
*
* * Typical tail/residue handling after a fault retries the copy
* byte-by-byte until the fault happens again. Re-triggering machine
@@ -717,23 +716,22 @@ static size_t copy_pipe_to_iter_mcsafe(const void *addr, size_t bytes,
* * ITER_KVEC, ITER_PIPE, and ITER_BVEC can return short copies.
* Compare to copy_to_iter() where only ITER_IOVEC attempts might return
* a short copy.
- *
- * See MCSAFE_TEST for self-test.
*/
-size_t _copy_to_iter_mcsafe(const void *addr, size_t bytes, struct iov_iter *i)
+size_t _copy_mc_to_iter(const void *addr, size_t bytes, struct iov_iter *i)
{
const char *from = addr;
unsigned long rem, curr_addr, s_addr = (unsigned long) addr;
if (unlikely(iov_iter_is_pipe(i)))
- return copy_pipe_to_iter_mcsafe(addr, bytes, i);
+ return copy_mc_pipe_to_iter(addr, bytes, i);
if (iter_is_iovec(i))
might_fault();
iterate_and_advance(i, bytes, v,
- copyout_mcsafe(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len),
+ copyout_mc(v.iov_base, (from += v.iov_len) - v.iov_len,
+ v.iov_len),
({
- rem = memcpy_mcsafe_to_page(v.bv_page, v.bv_offset,
- (from += v.bv_len) - v.bv_len, v.bv_len);
+ rem = copy_mc_to_page(v.bv_page, v.bv_offset,
+ (from += v.bv_len) - v.bv_len, v.bv_len);
if (rem) {
curr_addr = (unsigned long) from;
bytes = curr_addr - s_addr - rem;
@@ -741,8 +739,8 @@ size_t _copy_to_iter_mcsafe(const void *addr, size_t bytes, struct iov_iter *i)
}
}),
({
- rem = memcpy_mcsafe(v.iov_base, (from += v.iov_len) - v.iov_len,
- v.iov_len);
+ rem = copy_mc_to_kernel(v.iov_base, (from += v.iov_len)
+ - v.iov_len, v.iov_len);
if (rem) {
curr_addr = (unsigned long) from;
bytes = curr_addr - s_addr - rem;
@@ -753,8 +751,8 @@ size_t _copy_to_iter_mcsafe(const void *addr, size_t bytes, struct iov_iter *i)
return bytes;
}
-EXPORT_SYMBOL_GPL(_copy_to_iter_mcsafe);
-#endif /* CONFIG_ARCH_HAS_UACCESS_MCSAFE */
+EXPORT_SYMBOL_GPL(_copy_mc_to_iter);
+#endif /* CONFIG_ARCH_HAS_COPY_MC */
size_t _copy_from_iter(void *addr, size_t bytes, struct iov_iter *i)
{
diff --git a/tools/arch/x86/include/asm/mcsafe_test.h b/tools/arch/x86/include/asm/mcsafe_test.h
deleted file mode 100644
index 2ccd588fbad4..000000000000
--- a/tools/arch/x86/include/asm/mcsafe_test.h
+++ /dev/null
@@ -1,13 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef _MCSAFE_TEST_H_
-#define _MCSAFE_TEST_H_
-
-.macro MCSAFE_TEST_CTL
-.endm
-
-.macro MCSAFE_TEST_SRC reg count target
-.endm
-
-.macro MCSAFE_TEST_DST reg count target
-.endm
-#endif /* _MCSAFE_TEST_H_ */
diff --git a/tools/arch/x86/lib/memcpy_64.S b/tools/arch/x86/lib/memcpy_64.S
index 45f8e1b02241..0b5b8ae56bd9 100644
--- a/tools/arch/x86/lib/memcpy_64.S
+++ b/tools/arch/x86/lib/memcpy_64.S
@@ -4,7 +4,6 @@
#include <linux/linkage.h>
#include <asm/errno.h>
#include <asm/cpufeatures.h>
-#include <asm/mcsafe_test.h>
#include <asm/alternative-asm.h>
#include <asm/export.h>
@@ -187,117 +186,3 @@ SYM_FUNC_START(memcpy_orig)
SYM_FUNC_END(memcpy_orig)
.popsection
-
-#ifndef CONFIG_UML
-
-MCSAFE_TEST_CTL
-
-/*
- * __memcpy_mcsafe - memory copy with machine check exception handling
- * Note that we only catch machine checks when reading the source addresses.
- * Writes to target are posted and don't generate machine checks.
- */
-SYM_FUNC_START(__memcpy_mcsafe)
- cmpl $8, %edx
- /* Less than 8 bytes? Go to byte copy loop */
- jb .L_no_whole_words
-
- /* Check for bad alignment of source */
- testl $7, %esi
- /* Already aligned */
- jz .L_8byte_aligned
-
- /* Copy one byte at a time until source is 8-byte aligned */
- movl %esi, %ecx
- andl $7, %ecx
- subl $8, %ecx
- negl %ecx
- subl %ecx, %edx
-.L_read_leading_bytes:
- movb (%rsi), %al
- MCSAFE_TEST_SRC %rsi 1 .E_leading_bytes
- MCSAFE_TEST_DST %rdi 1 .E_leading_bytes
-.L_write_leading_bytes:
- movb %al, (%rdi)
- incq %rsi
- incq %rdi
- decl %ecx
- jnz .L_read_leading_bytes
-
-.L_8byte_aligned:
- movl %edx, %ecx
- andl $7, %edx
- shrl $3, %ecx
- jz .L_no_whole_words
-
-.L_read_words:
- movq (%rsi), %r8
- MCSAFE_TEST_SRC %rsi 8 .E_read_words
- MCSAFE_TEST_DST %rdi 8 .E_write_words
-.L_write_words:
- movq %r8, (%rdi)
- addq $8, %rsi
- addq $8, %rdi
- decl %ecx
- jnz .L_read_words
-
- /* Any trailing bytes? */
-.L_no_whole_words:
- andl %edx, %edx
- jz .L_done_memcpy_trap
-
- /* Copy trailing bytes */
- movl %edx, %ecx
-.L_read_trailing_bytes:
- movb (%rsi), %al
- MCSAFE_TEST_SRC %rsi 1 .E_trailing_bytes
- MCSAFE_TEST_DST %rdi 1 .E_trailing_bytes
-.L_write_trailing_bytes:
- movb %al, (%rdi)
- incq %rsi
- incq %rdi
- decl %ecx
- jnz .L_read_trailing_bytes
-
- /* Copy successful. Return zero */
-.L_done_memcpy_trap:
- xorl %eax, %eax
-.L_done:
- ret
-SYM_FUNC_END(__memcpy_mcsafe)
-EXPORT_SYMBOL_GPL(__memcpy_mcsafe)
-
- .section .fixup, "ax"
- /*
- * Return number of bytes not copied for any failure. Note that
- * there is no "tail" handling since the source buffer is 8-byte
- * aligned and poison is cacheline aligned.
- */
-.E_read_words:
- shll $3, %ecx
-.E_leading_bytes:
- addl %edx, %ecx
-.E_trailing_bytes:
- mov %ecx, %eax
- jmp .L_done
-
- /*
- * For write fault handling, given the destination is unaligned,
- * we handle faults on multi-byte writes with a byte-by-byte
- * copy up to the write-protected page.
- */
-.E_write_words:
- shll $3, %ecx
- addl %edx, %ecx
- movl %ecx, %edx
- jmp mcsafe_handle_tail
-
- .previous
-
- _ASM_EXTABLE_FAULT(.L_read_leading_bytes, .E_leading_bytes)
- _ASM_EXTABLE_FAULT(.L_read_words, .E_read_words)
- _ASM_EXTABLE_FAULT(.L_read_trailing_bytes, .E_trailing_bytes)
- _ASM_EXTABLE(.L_write_leading_bytes, .E_leading_bytes)
- _ASM_EXTABLE(.L_write_words, .E_write_words)
- _ASM_EXTABLE(.L_write_trailing_bytes, .E_trailing_bytes)
-#endif
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index e034a8f24f46..893f021fec63 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -548,8 +548,8 @@ static const char *uaccess_safe_builtin[] = {
"__ubsan_handle_shift_out_of_bounds",
/* misc */
"csum_partial_copy_generic",
- "__memcpy_mcsafe",
- "mcsafe_handle_tail",
+ "copy_mc_fragile",
+ "copy_mc_fragile_handle_tail",
"ftrace_likely_update", /* CONFIG_TRACE_BRANCH_PROFILING */
NULL
};
diff --git a/tools/perf/bench/Build b/tools/perf/bench/Build
index dd68a40a790c..878db6a59a41 100644
--- a/tools/perf/bench/Build
+++ b/tools/perf/bench/Build
@@ -13,7 +13,6 @@ perf-y += synthesize.o
perf-y += kallsyms-parse.o
perf-y += find-bit-bench.o
-perf-$(CONFIG_X86_64) += mem-memcpy-x86-64-lib.o
perf-$(CONFIG_X86_64) += mem-memcpy-x86-64-asm.o
perf-$(CONFIG_X86_64) += mem-memset-x86-64-asm.o
diff --git a/tools/perf/bench/mem-memcpy-x86-64-lib.c b/tools/perf/bench/mem-memcpy-x86-64-lib.c
deleted file mode 100644
index 4130734dde84..000000000000
--- a/tools/perf/bench/mem-memcpy-x86-64-lib.c
+++ /dev/null
@@ -1,24 +0,0 @@
-/*
- * From code in arch/x86/lib/usercopy_64.c, copied to keep tools/ copy
- * of the kernel's arch/x86/lib/memcpy_64.s used in 'perf bench mem memcpy'
- * happy.
- */
-#include <linux/types.h>
-
-unsigned long __memcpy_mcsafe(void *dst, const void *src, size_t cnt);
-unsigned long mcsafe_handle_tail(char *to, char *from, unsigned len);
-
-unsigned long mcsafe_handle_tail(char *to, char *from, unsigned len)
-{
- for (; len; --len, to++, from++) {
- /*
- * Call the assembly routine back directly since
- * memcpy_mcsafe() may silently fallback to memcpy.
- */
- unsigned long rem = __memcpy_mcsafe(to, from, 1);
-
- if (rem)
- break;
- }
- return len;
-}
diff --git a/tools/testing/nvdimm/test/nfit.c b/tools/testing/nvdimm/test/nfit.c
index a1a5dc645b40..2ac0fff6dad8 100644
--- a/tools/testing/nvdimm/test/nfit.c
+++ b/tools/testing/nvdimm/test/nfit.c
@@ -23,7 +23,8 @@
#include "nfit_test.h"
#include "../watermark.h"
-#include <asm/mcsafe_test.h>
+#include <asm/copy_mc_test.h>
+#include <asm/mce.h>
/*
* Generate an NFIT table to describe the following topology:
@@ -3283,7 +3284,7 @@ static struct platform_driver nfit_test_driver = {
.id_table = nfit_test_id,
};
-static char mcsafe_buf[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE)));
+static char copy_mc_buf[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE)));
enum INJECT {
INJECT_NONE,
@@ -3291,7 +3292,7 @@ enum INJECT {
INJECT_DST,
};
-static void mcsafe_test_init(char *dst, char *src, size_t size)
+static void copy_mc_test_init(char *dst, char *src, size_t size)
{
size_t i;
@@ -3300,7 +3301,7 @@ static void mcsafe_test_init(char *dst, char *src, size_t size)
src[i] = (char) i;
}
-static bool mcsafe_test_validate(unsigned char *dst, unsigned char *src,
+static bool copy_mc_test_validate(unsigned char *dst, unsigned char *src,
size_t size, unsigned long rem)
{
size_t i;
@@ -3321,12 +3322,12 @@ static bool mcsafe_test_validate(unsigned char *dst, unsigned char *src,
return true;
}
-void mcsafe_test(void)
+void copy_mc_test(void)
{
char *inject_desc[] = { "none", "source", "destination" };
enum INJECT inj;
- if (IS_ENABLED(CONFIG_MCSAFE_TEST)) {
+ if (IS_ENABLED(CONFIG_COPY_MC_TEST)) {
pr_info("%s: run...\n", __func__);
} else {
pr_info("%s: disabled, skip.\n", __func__);
@@ -3344,31 +3345,31 @@ void mcsafe_test(void)
switch (inj) {
case INJECT_NONE:
- mcsafe_inject_src(NULL);
- mcsafe_inject_dst(NULL);
- dst = &mcsafe_buf[2048];
- src = &mcsafe_buf[1024 - i];
+ copy_mc_inject_src(NULL);
+ copy_mc_inject_dst(NULL);
+ dst = ©_mc_buf[2048];
+ src = ©_mc_buf[1024 - i];
expect = 0;
break;
case INJECT_SRC:
- mcsafe_inject_src(&mcsafe_buf[1024]);
- mcsafe_inject_dst(NULL);
- dst = &mcsafe_buf[2048];
- src = &mcsafe_buf[1024 - i];
+ copy_mc_inject_src(©_mc_buf[1024]);
+ copy_mc_inject_dst(NULL);
+ dst = ©_mc_buf[2048];
+ src = ©_mc_buf[1024 - i];
expect = 512 - i;
break;
case INJECT_DST:
- mcsafe_inject_src(NULL);
- mcsafe_inject_dst(&mcsafe_buf[2048]);
- dst = &mcsafe_buf[2048 - i];
- src = &mcsafe_buf[1024];
+ copy_mc_inject_src(NULL);
+ copy_mc_inject_dst(©_mc_buf[2048]);
+ dst = ©_mc_buf[2048 - i];
+ src = ©_mc_buf[1024];
expect = 512 - i;
break;
}
- mcsafe_test_init(dst, src, 512);
- rem = __memcpy_mcsafe(dst, src, 512);
- valid = mcsafe_test_validate(dst, src, 512, expect);
+ copy_mc_test_init(dst, src, 512);
+ rem = copy_mc_fragile(dst, src, 512);
+ valid = copy_mc_test_validate(dst, src, 512, expect);
if (rem == expect && valid)
continue;
pr_info("%s: copy(%#lx, %#lx, %d) off: %d rem: %ld %s expect: %ld\n",
@@ -3380,8 +3381,8 @@ void mcsafe_test(void)
}
}
- mcsafe_inject_src(NULL);
- mcsafe_inject_dst(NULL);
+ copy_mc_inject_src(NULL);
+ copy_mc_inject_dst(NULL);
}
static __init int nfit_test_init(void)
@@ -3392,7 +3393,7 @@ static __init int nfit_test_init(void)
libnvdimm_test();
acpi_nfit_test();
device_dax_test();
- mcsafe_test();
+ copy_mc_test();
dax_pmem_test();
dax_pmem_core_test();
#ifdef CONFIG_DEV_DAX_PMEM_COMPAT
diff --git a/tools/testing/selftests/powerpc/copyloops/.gitignore b/tools/testing/selftests/powerpc/copyloops/.gitignore
index ddaf140b8255..994b11af765c 100644
--- a/tools/testing/selftests/powerpc/copyloops/.gitignore
+++ b/tools/testing/selftests/powerpc/copyloops/.gitignore
@@ -12,4 +12,4 @@ memcpy_p7_t1
copyuser_64_exc_t0
copyuser_64_exc_t1
copyuser_64_exc_t2
-memcpy_mcsafe_64
+copy_mc_64
diff --git a/tools/testing/selftests/powerpc/copyloops/Makefile b/tools/testing/selftests/powerpc/copyloops/Makefile
index 0917983a1c78..3095b1f1c02b 100644
--- a/tools/testing/selftests/powerpc/copyloops/Makefile
+++ b/tools/testing/selftests/powerpc/copyloops/Makefile
@@ -12,7 +12,7 @@ ASFLAGS = $(CFLAGS) -Wa,-mpower4
TEST_GEN_PROGS := copyuser_64_t0 copyuser_64_t1 copyuser_64_t2 \
copyuser_p7_t0 copyuser_p7_t1 \
memcpy_64_t0 memcpy_64_t1 memcpy_64_t2 \
- memcpy_p7_t0 memcpy_p7_t1 memcpy_mcsafe_64 \
+ memcpy_p7_t0 memcpy_p7_t1 copy_mc_64 \
copyuser_64_exc_t0 copyuser_64_exc_t1 copyuser_64_exc_t2
EXTRA_SOURCES := validate.c ../harness.c stubs.S
@@ -45,9 +45,9 @@ $(OUTPUT)/memcpy_p7_t%: memcpy_power7.S $(EXTRA_SOURCES)
-D SELFTEST_CASE=$(subst memcpy_p7_t,,$(notdir $@)) \
-o $@ $^
-$(OUTPUT)/memcpy_mcsafe_64: memcpy_mcsafe_64.S $(EXTRA_SOURCES)
+$(OUTPUT)/copy_mc_64: copy_mc_64.S $(EXTRA_SOURCES)
$(CC) $(CPPFLAGS) $(CFLAGS) \
- -D COPY_LOOP=test_memcpy_mcsafe \
+ -D COPY_LOOP=test_copy_mc_generic \
-o $@ $^
$(OUTPUT)/copyuser_64_exc_t%: copyuser_64.S exc_validate.c ../harness.c \
diff --git a/tools/testing/selftests/powerpc/copyloops/copy_mc_64.S b/tools/testing/selftests/powerpc/copyloops/copy_mc_64.S
new file mode 120000
index 000000000000..dcbe06d500fb
--- /dev/null
+++ b/tools/testing/selftests/powerpc/copyloops/copy_mc_64.S
@@ -0,0 +1 @@
+../../../../../arch/powerpc/lib/copy_mc_64.S
\ No newline at end of file
diff --git a/tools/testing/selftests/powerpc/copyloops/memcpy_mcsafe_64.S b/tools/testing/selftests/powerpc/copyloops/memcpy_mcsafe_64.S
deleted file mode 120000
index f0feef3062f6..000000000000
--- a/tools/testing/selftests/powerpc/copyloops/memcpy_mcsafe_64.S
+++ /dev/null
@@ -1 +0,0 @@
-../../../../../arch/powerpc/lib/memcpy_mcsafe_64.S
\ No newline at end of file
4 years, 3 months
- 1
- 0
FAILED: patch "[PATCH] x86, powerpc: Rename memcpy_mcsafe() to copy_mc_to_{user, " failed to apply to 5.4-stable tree
by gregkh＠linuxfoundation.org
The patch below does not apply to the 5.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From ec6347bb43395cb92126788a1a5b25302543f815 Mon Sep 17 00:00:00 2001
From: Dan Williams <dan.j.williams(a)intel.com>
Date: Mon, 5 Oct 2020 20:40:16 -0700
Subject: [PATCH] x86, powerpc: Rename memcpy_mcsafe() to copy_mc_to_{user,
kernel}()
In reaction to a proposal to introduce a memcpy_mcsafe_fast()
implementation Linus points out that memcpy_mcsafe() is poorly named
relative to communicating the scope of the interface. Specifically what
addresses are valid to pass as source, destination, and what faults /
exceptions are handled.
Of particular concern is that even though x86 might be able to handle
the semantics of copy_mc_to_user() with its common copy_user_generic()
implementation other archs likely need / want an explicit path for this
case:
On Fri, May 1, 2020 at 11:28 AM Linus Torvalds <torvalds(a)linux-foundation.org> wrote:
>
> On Thu, Apr 30, 2020 at 6:21 PM Dan Williams <dan.j.williams(a)intel.com> wrote:
> >
> > However now I see that copy_user_generic() works for the wrong reason.
> > It works because the exception on the source address due to poison
> > looks no different than a write fault on the user address to the
> > caller, it's still just a short copy. So it makes copy_to_user() work
> > for the wrong reason relative to the name.
>
> Right.
>
> And it won't work that way on other architectures. On x86, we have a
> generic function that can take faults on either side, and we use it
> for both cases (and for the "in_user" case too), but that's an
> artifact of the architecture oddity.
>
> In fact, it's probably wrong even on x86 - because it can hide bugs -
> but writing those things is painful enough that everybody prefers
> having just one function.
Replace a single top-level memcpy_mcsafe() with either
copy_mc_to_user(), or copy_mc_to_kernel().
Introduce an x86 copy_mc_fragile() name as the rename for the
low-level x86 implementation formerly named memcpy_mcsafe(). It is used
as the slow / careful backend that is supplanted by a fast
copy_mc_generic() in a follow-on patch.
One side-effect of this reorganization is that separating copy_mc_64.S
to its own file means that perf no longer needs to track dependencies
for its memcpy_64.S benchmarks.
[ bp: Massage a bit. ]
Signed-off-by: Dan Williams <dan.j.williams(a)intel.com>
Signed-off-by: Borislav Petkov <bp(a)suse.de>
Reviewed-by: Tony Luck <tony.luck(a)intel.com>
Acked-by: Michael Ellerman <mpe(a)ellerman.id.au>
Cc: <stable(a)vger.kernel.org>
Link: http://lore.kernel.org/r/CAHk-=wjSqtXAqfUJxFtWNwmguFASTgB0dz1dT3V-78Quiezqb…
Link: https://lkml.kernel.org/r/160195561680.2163339.11574962055305783722.stgit@d…
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 1f48bbfb3ce9..76473eda3426 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -136,7 +136,7 @@ config PPC
select ARCH_HAS_STRICT_KERNEL_RWX if (PPC32 && !HIBERNATION)
select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
select ARCH_HAS_UACCESS_FLUSHCACHE
- select ARCH_HAS_UACCESS_MCSAFE if PPC64
+ select ARCH_HAS_COPY_MC if PPC64
select ARCH_HAS_UBSAN_SANITIZE_ALL
select ARCH_HAVE_NMI_SAFE_CMPXCHG
select ARCH_KEEP_MEMBLOCK
diff --git a/arch/powerpc/include/asm/string.h b/arch/powerpc/include/asm/string.h
index 283552cd0e58..2aa0e31e6884 100644
--- a/arch/powerpc/include/asm/string.h
+++ b/arch/powerpc/include/asm/string.h
@@ -53,9 +53,7 @@ void *__memmove(void *to, const void *from, __kernel_size_t n);
#ifndef CONFIG_KASAN
#define __HAVE_ARCH_MEMSET32
#define __HAVE_ARCH_MEMSET64
-#define __HAVE_ARCH_MEMCPY_MCSAFE
-extern int memcpy_mcsafe(void *dst, const void *src, __kernel_size_t sz);
extern void *__memset16(uint16_t *, uint16_t v, __kernel_size_t);
extern void *__memset32(uint32_t *, uint32_t v, __kernel_size_t);
extern void *__memset64(uint64_t *, uint64_t v, __kernel_size_t);
diff --git a/arch/powerpc/include/asm/uaccess.h b/arch/powerpc/include/asm/uaccess.h
index 00699903f1ef..20a35373cafc 100644
--- a/arch/powerpc/include/asm/uaccess.h
+++ b/arch/powerpc/include/asm/uaccess.h
@@ -435,6 +435,32 @@ do { \
extern unsigned long __copy_tofrom_user(void __user *to,
const void __user *from, unsigned long size);
+#ifdef CONFIG_ARCH_HAS_COPY_MC
+unsigned long __must_check
+copy_mc_generic(void *to, const void *from, unsigned long size);
+
+static inline unsigned long __must_check
+copy_mc_to_kernel(void *to, const void *from, unsigned long size)
+{
+ return copy_mc_generic(to, from, size);
+}
+#define copy_mc_to_kernel copy_mc_to_kernel
+
+static inline unsigned long __must_check
+copy_mc_to_user(void __user *to, const void *from, unsigned long n)
+{
+ if (likely(check_copy_size(from, n, true))) {
+ if (access_ok(to, n)) {
+ allow_write_to_user(to, n);
+ n = copy_mc_generic((void *)to, from, n);
+ prevent_write_to_user(to, n);
+ }
+ }
+
+ return n;
+}
+#endif
+
#ifdef __powerpc64__
static inline unsigned long
raw_copy_in_user(void __user *to, const void __user *from, unsigned long n)
@@ -523,20 +549,6 @@ raw_copy_to_user(void __user *to, const void *from, unsigned long n)
return ret;
}
-static __always_inline unsigned long __must_check
-copy_to_user_mcsafe(void __user *to, const void *from, unsigned long n)
-{
- if (likely(check_copy_size(from, n, true))) {
- if (access_ok(to, n)) {
- allow_write_to_user(to, n);
- n = memcpy_mcsafe((void *)to, from, n);
- prevent_write_to_user(to, n);
- }
- }
-
- return n;
-}
-
unsigned long __arch_clear_user(void __user *addr, unsigned long size);
static inline unsigned long clear_user(void __user *addr, unsigned long size)
diff --git a/arch/powerpc/lib/Makefile b/arch/powerpc/lib/Makefile
index d66a645503eb..69a91b571845 100644
--- a/arch/powerpc/lib/Makefile
+++ b/arch/powerpc/lib/Makefile
@@ -39,7 +39,7 @@ obj-$(CONFIG_PPC_BOOK3S_64) += copyuser_power7.o copypage_power7.o \
memcpy_power7.o
obj64-y += copypage_64.o copyuser_64.o mem_64.o hweight_64.o \
- memcpy_64.o memcpy_mcsafe_64.o
+ memcpy_64.o copy_mc_64.o
ifndef CONFIG_PPC_QUEUED_SPINLOCKS
obj64-$(CONFIG_SMP) += locks.o
diff --git a/arch/powerpc/lib/memcpy_mcsafe_64.S b/arch/powerpc/lib/copy_mc_64.S
similarity index 98%
rename from arch/powerpc/lib/memcpy_mcsafe_64.S
rename to arch/powerpc/lib/copy_mc_64.S
index cb882d9a6d8a..88d46c471493 100644
--- a/arch/powerpc/lib/memcpy_mcsafe_64.S
+++ b/arch/powerpc/lib/copy_mc_64.S
@@ -50,7 +50,7 @@ err3; stb r0,0(r3)
blr
-_GLOBAL(memcpy_mcsafe)
+_GLOBAL(copy_mc_generic)
mr r7,r5
cmpldi r5,16
blt .Lshort_copy
@@ -239,4 +239,4 @@ err1; stb r0,0(r3)
15: li r3,0
blr
-EXPORT_SYMBOL_GPL(memcpy_mcsafe);
+EXPORT_SYMBOL_GPL(copy_mc_generic);
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 7101ac64bb20..e876b3a087f9 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -75,7 +75,7 @@ config X86
select ARCH_HAS_PTE_DEVMAP if X86_64
select ARCH_HAS_PTE_SPECIAL
select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64
- select ARCH_HAS_UACCESS_MCSAFE if X86_64 && X86_MCE
+ select ARCH_HAS_COPY_MC if X86_64
select ARCH_HAS_SET_MEMORY
select ARCH_HAS_SET_DIRECT_MAP
select ARCH_HAS_STRICT_KERNEL_RWX
diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug
index ee1d3c5834c6..27b5e2bc6a01 100644
--- a/arch/x86/Kconfig.debug
+++ b/arch/x86/Kconfig.debug
@@ -62,7 +62,7 @@ config EARLY_PRINTK_USB_XDBC
You should normally say N here, unless you want to debug early
crashes or need a very simple printk logging facility.
-config MCSAFE_TEST
+config COPY_MC_TEST
def_bool n
config EFI_PGT_DUMP
diff --git a/arch/x86/include/asm/copy_mc_test.h b/arch/x86/include/asm/copy_mc_test.h
new file mode 100644
index 000000000000..e4991ba96726
--- /dev/null
+++ b/arch/x86/include/asm/copy_mc_test.h
@@ -0,0 +1,75 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _COPY_MC_TEST_H_
+#define _COPY_MC_TEST_H_
+
+#ifndef __ASSEMBLY__
+#ifdef CONFIG_COPY_MC_TEST
+extern unsigned long copy_mc_test_src;
+extern unsigned long copy_mc_test_dst;
+
+static inline void copy_mc_inject_src(void *addr)
+{
+ if (addr)
+ copy_mc_test_src = (unsigned long) addr;
+ else
+ copy_mc_test_src = ~0UL;
+}
+
+static inline void copy_mc_inject_dst(void *addr)
+{
+ if (addr)
+ copy_mc_test_dst = (unsigned long) addr;
+ else
+ copy_mc_test_dst = ~0UL;
+}
+#else /* CONFIG_COPY_MC_TEST */
+static inline void copy_mc_inject_src(void *addr)
+{
+}
+
+static inline void copy_mc_inject_dst(void *addr)
+{
+}
+#endif /* CONFIG_COPY_MC_TEST */
+
+#else /* __ASSEMBLY__ */
+#include <asm/export.h>
+
+#ifdef CONFIG_COPY_MC_TEST
+.macro COPY_MC_TEST_CTL
+ .pushsection .data
+ .align 8
+ .globl copy_mc_test_src
+ copy_mc_test_src:
+ .quad 0
+ EXPORT_SYMBOL_GPL(copy_mc_test_src)
+ .globl copy_mc_test_dst
+ copy_mc_test_dst:
+ .quad 0
+ EXPORT_SYMBOL_GPL(copy_mc_test_dst)
+ .popsection
+.endm
+
+.macro COPY_MC_TEST_SRC reg count target
+ leaq \count(\reg), %r9
+ cmp copy_mc_test_src, %r9
+ ja \target
+.endm
+
+.macro COPY_MC_TEST_DST reg count target
+ leaq \count(\reg), %r9
+ cmp copy_mc_test_dst, %r9
+ ja \target
+.endm
+#else
+.macro COPY_MC_TEST_CTL
+.endm
+
+.macro COPY_MC_TEST_SRC reg count target
+.endm
+
+.macro COPY_MC_TEST_DST reg count target
+.endm
+#endif /* CONFIG_COPY_MC_TEST */
+#endif /* __ASSEMBLY__ */
+#endif /* _COPY_MC_TEST_H_ */
diff --git a/arch/x86/include/asm/mce.h b/arch/x86/include/asm/mce.h
index 109af5c7f515..ba2062d6df92 100644
--- a/arch/x86/include/asm/mce.h
+++ b/arch/x86/include/asm/mce.h
@@ -174,6 +174,15 @@ extern void mce_unregister_decode_chain(struct notifier_block *nb);
extern int mce_p5_enabled;
+#ifdef CONFIG_ARCH_HAS_COPY_MC
+extern void enable_copy_mc_fragile(void);
+unsigned long __must_check copy_mc_fragile(void *dst, const void *src, unsigned cnt);
+#else
+static inline void enable_copy_mc_fragile(void)
+{
+}
+#endif
+
#ifdef CONFIG_X86_MCE
int mcheck_init(void);
void mcheck_cpu_init(struct cpuinfo_x86 *c);
diff --git a/arch/x86/include/asm/mcsafe_test.h b/arch/x86/include/asm/mcsafe_test.h
deleted file mode 100644
index eb59804b6201..000000000000
--- a/arch/x86/include/asm/mcsafe_test.h
+++ /dev/null
@@ -1,75 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef _MCSAFE_TEST_H_
-#define _MCSAFE_TEST_H_
-
-#ifndef __ASSEMBLY__
-#ifdef CONFIG_MCSAFE_TEST
-extern unsigned long mcsafe_test_src;
-extern unsigned long mcsafe_test_dst;
-
-static inline void mcsafe_inject_src(void *addr)
-{
- if (addr)
- mcsafe_test_src = (unsigned long) addr;
- else
- mcsafe_test_src = ~0UL;
-}
-
-static inline void mcsafe_inject_dst(void *addr)
-{
- if (addr)
- mcsafe_test_dst = (unsigned long) addr;
- else
- mcsafe_test_dst = ~0UL;
-}
-#else /* CONFIG_MCSAFE_TEST */
-static inline void mcsafe_inject_src(void *addr)
-{
-}
-
-static inline void mcsafe_inject_dst(void *addr)
-{
-}
-#endif /* CONFIG_MCSAFE_TEST */
-
-#else /* __ASSEMBLY__ */
-#include <asm/export.h>
-
-#ifdef CONFIG_MCSAFE_TEST
-.macro MCSAFE_TEST_CTL
- .pushsection .data
- .align 8
- .globl mcsafe_test_src
- mcsafe_test_src:
- .quad 0
- EXPORT_SYMBOL_GPL(mcsafe_test_src)
- .globl mcsafe_test_dst
- mcsafe_test_dst:
- .quad 0
- EXPORT_SYMBOL_GPL(mcsafe_test_dst)
- .popsection
-.endm
-
-.macro MCSAFE_TEST_SRC reg count target
- leaq \count(\reg), %r9
- cmp mcsafe_test_src, %r9
- ja \target
-.endm
-
-.macro MCSAFE_TEST_DST reg count target
- leaq \count(\reg), %r9
- cmp mcsafe_test_dst, %r9
- ja \target
-.endm
-#else
-.macro MCSAFE_TEST_CTL
-.endm
-
-.macro MCSAFE_TEST_SRC reg count target
-.endm
-
-.macro MCSAFE_TEST_DST reg count target
-.endm
-#endif /* CONFIG_MCSAFE_TEST */
-#endif /* __ASSEMBLY__ */
-#endif /* _MCSAFE_TEST_H_ */
diff --git a/arch/x86/include/asm/string_64.h b/arch/x86/include/asm/string_64.h
index 75314c3dbe47..6e450827f677 100644
--- a/arch/x86/include/asm/string_64.h
+++ b/arch/x86/include/asm/string_64.h
@@ -82,38 +82,6 @@ int strcmp(const char *cs, const char *ct);
#endif
-#define __HAVE_ARCH_MEMCPY_MCSAFE 1
-__must_check unsigned long __memcpy_mcsafe(void *dst, const void *src,
- size_t cnt);
-DECLARE_STATIC_KEY_FALSE(mcsafe_key);
-
-/**
- * memcpy_mcsafe - copy memory with indication if a machine check happened
- *
- * @dst: destination address
- * @src: source address
- * @cnt: number of bytes to copy
- *
- * Low level memory copy function that catches machine checks
- * We only call into the "safe" function on systems that can
- * actually do machine check recovery. Everyone else can just
- * use memcpy().
- *
- * Return 0 for success, or number of bytes not copied if there was an
- * exception.
- */
-static __always_inline __must_check unsigned long
-memcpy_mcsafe(void *dst, const void *src, size_t cnt)
-{
-#ifdef CONFIG_X86_MCE
- if (static_branch_unlikely(&mcsafe_key))
- return __memcpy_mcsafe(dst, src, cnt);
- else
-#endif
- memcpy(dst, src, cnt);
- return 0;
-}
-
#ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE
#define __HAVE_ARCH_MEMCPY_FLUSHCACHE 1
void __memcpy_flushcache(void *dst, const void *src, size_t cnt);
diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h
index ecefaffd15d4..eff7fb847149 100644
--- a/arch/x86/include/asm/uaccess.h
+++ b/arch/x86/include/asm/uaccess.h
@@ -455,6 +455,15 @@ extern __must_check long strnlen_user(const char __user *str, long n);
unsigned long __must_check clear_user(void __user *mem, unsigned long len);
unsigned long __must_check __clear_user(void __user *mem, unsigned long len);
+#ifdef CONFIG_ARCH_HAS_COPY_MC
+unsigned long __must_check
+copy_mc_to_kernel(void *to, const void *from, unsigned len);
+#define copy_mc_to_kernel copy_mc_to_kernel
+
+unsigned long __must_check
+copy_mc_to_user(void *to, const void *from, unsigned len);
+#endif
+
/*
* movsl can be slow when source and dest are not both 8-byte aligned
*/
diff --git a/arch/x86/include/asm/uaccess_64.h b/arch/x86/include/asm/uaccess_64.h
index bc10e3dc64fe..e7265a552f4f 100644
--- a/arch/x86/include/asm/uaccess_64.h
+++ b/arch/x86/include/asm/uaccess_64.h
@@ -46,22 +46,6 @@ copy_user_generic(void *to, const void *from, unsigned len)
return ret;
}
-static __always_inline __must_check unsigned long
-copy_to_user_mcsafe(void *to, const void *from, unsigned len)
-{
- unsigned long ret;
-
- __uaccess_begin();
- /*
- * Note, __memcpy_mcsafe() is explicitly used since it can
- * handle exceptions / faults. memcpy_mcsafe() may fall back to
- * memcpy() which lacks this handling.
- */
- ret = __memcpy_mcsafe(to, from, len);
- __uaccess_end();
- return ret;
-}
-
static __always_inline __must_check unsigned long
raw_copy_from_user(void *dst, const void __user *src, unsigned long size)
{
@@ -102,8 +86,4 @@ __copy_from_user_flushcache(void *dst, const void __user *src, unsigned size)
kasan_check_write(dst, size);
return __copy_user_flushcache(dst, src, size);
}
-
-unsigned long
-mcsafe_handle_tail(char *to, char *from, unsigned len);
-
#endif /* _ASM_X86_UACCESS_64_H */
diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c
index 11b6697be010..b5b70f4b351d 100644
--- a/arch/x86/kernel/cpu/mce/core.c
+++ b/arch/x86/kernel/cpu/mce/core.c
@@ -40,7 +40,6 @@
#include <linux/debugfs.h>
#include <linux/irq_work.h>
#include <linux/export.h>
-#include <linux/jump_label.h>
#include <linux/set_memory.h>
#include <linux/sync_core.h>
#include <linux/task_work.h>
@@ -2124,7 +2123,7 @@ void mce_disable_bank(int bank)
and older.
* mce=nobootlog Don't log MCEs from before booting.
* mce=bios_cmci_threshold Don't program the CMCI threshold
- * mce=recovery force enable memcpy_mcsafe()
+ * mce=recovery force enable copy_mc_fragile()
*/
static int __init mcheck_enable(char *str)
{
@@ -2732,13 +2731,10 @@ static void __init mcheck_debugfs_init(void)
static void __init mcheck_debugfs_init(void) { }
#endif
-DEFINE_STATIC_KEY_FALSE(mcsafe_key);
-EXPORT_SYMBOL_GPL(mcsafe_key);
-
static int __init mcheck_late_init(void)
{
if (mca_cfg.recovery)
- static_branch_inc(&mcsafe_key);
+ enable_copy_mc_fragile();
mcheck_debugfs_init();
diff --git a/arch/x86/kernel/quirks.c b/arch/x86/kernel/quirks.c
index 1b10717c9321..6d0df6a58873 100644
--- a/arch/x86/kernel/quirks.c
+++ b/arch/x86/kernel/quirks.c
@@ -8,6 +8,7 @@
#include <asm/hpet.h>
#include <asm/setup.h>
+#include <asm/mce.h>
#if defined(CONFIG_X86_IO_APIC) && defined(CONFIG_SMP) && defined(CONFIG_PCI)
@@ -624,10 +625,6 @@ static void amd_disable_seq_and_redirect_scrub(struct pci_dev *dev)
DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_16H_NB_F3,
amd_disable_seq_and_redirect_scrub);
-#if defined(CONFIG_X86_64) && defined(CONFIG_X86_MCE)
-#include <linux/jump_label.h>
-#include <asm/string_64.h>
-
/* Ivy Bridge, Haswell, Broadwell */
static void quirk_intel_brickland_xeon_ras_cap(struct pci_dev *pdev)
{
@@ -636,7 +633,7 @@ static void quirk_intel_brickland_xeon_ras_cap(struct pci_dev *pdev)
pci_read_config_dword(pdev, 0x84, &capid0);
if (capid0 & 0x10)
- static_branch_inc(&mcsafe_key);
+ enable_copy_mc_fragile();
}
/* Skylake */
@@ -653,7 +650,7 @@ static void quirk_intel_purley_xeon_ras_cap(struct pci_dev *pdev)
* enabled, so memory machine check recovery is also enabled.
*/
if ((capid0 & 0xc0) == 0xc0 || (capid5 & 0x1e0))
- static_branch_inc(&mcsafe_key);
+ enable_copy_mc_fragile();
}
DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x0ec3, quirk_intel_brickland_xeon_ras_cap);
@@ -661,7 +658,6 @@ DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x2fc0, quirk_intel_brickland_xeon_
DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x6fc0, quirk_intel_brickland_xeon_ras_cap);
DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x2083, quirk_intel_purley_xeon_ras_cap);
#endif
-#endif
bool x86_apple_machine;
EXPORT_SYMBOL(x86_apple_machine);
diff --git a/arch/x86/lib/Makefile b/arch/x86/lib/Makefile
index d46fff11f06f..f7d23c9c22b2 100644
--- a/arch/x86/lib/Makefile
+++ b/arch/x86/lib/Makefile
@@ -44,6 +44,7 @@ obj-$(CONFIG_SMP) += msr-smp.o cache-smp.o
lib-y := delay.o misc.o cmdline.o cpu.o
lib-y += usercopy_$(BITS).o usercopy.o getuser.o putuser.o
lib-y += memcpy_$(BITS).o
+lib-$(CONFIG_ARCH_HAS_COPY_MC) += copy_mc.o copy_mc_64.o
lib-$(CONFIG_INSTRUCTION_DECODER) += insn.o inat.o insn-eval.o
lib-$(CONFIG_RANDOMIZE_BASE) += kaslr.o
lib-$(CONFIG_FUNCTION_ERROR_INJECTION) += error-inject.o
diff --git a/arch/x86/lib/copy_mc.c b/arch/x86/lib/copy_mc.c
new file mode 100644
index 000000000000..2633635530b7
--- /dev/null
+++ b/arch/x86/lib/copy_mc.c
@@ -0,0 +1,82 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright(c) 2016-2020 Intel Corporation. All rights reserved. */
+
+#include <linux/jump_label.h>
+#include <linux/uaccess.h>
+#include <linux/export.h>
+#include <linux/string.h>
+#include <linux/types.h>
+
+#include <asm/mce.h>
+
+#ifdef CONFIG_X86_MCE
+/*
+ * See COPY_MC_TEST for self-test of the copy_mc_fragile()
+ * implementation.
+ */
+static DEFINE_STATIC_KEY_FALSE(copy_mc_fragile_key);
+
+void enable_copy_mc_fragile(void)
+{
+ static_branch_inc(©_mc_fragile_key);
+}
+#define copy_mc_fragile_enabled (static_branch_unlikely(©_mc_fragile_key))
+
+/*
+ * Similar to copy_user_handle_tail, probe for the write fault point, or
+ * source exception point.
+ */
+__visible notrace unsigned long
+copy_mc_fragile_handle_tail(char *to, char *from, unsigned len)
+{
+ for (; len; --len, to++, from++)
+ if (copy_mc_fragile(to, from, 1))
+ break;
+ return len;
+}
+#else
+/*
+ * No point in doing careful copying, or consulting a static key when
+ * there is no #MC handler in the CONFIG_X86_MCE=n case.
+ */
+void enable_copy_mc_fragile(void)
+{
+}
+#define copy_mc_fragile_enabled (0)
+#endif
+
+/**
+ * copy_mc_to_kernel - memory copy that handles source exceptions
+ *
+ * @dst: destination address
+ * @src: source address
+ * @len: number of bytes to copy
+ *
+ * Call into the 'fragile' version on systems that have trouble
+ * actually do machine check recovery. Everyone else can just
+ * use memcpy().
+ *
+ * Return 0 for success, or number of bytes not copied if there was an
+ * exception.
+ */
+unsigned long __must_check copy_mc_to_kernel(void *dst, const void *src, unsigned len)
+{
+ if (copy_mc_fragile_enabled)
+ return copy_mc_fragile(dst, src, len);
+ memcpy(dst, src, len);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(copy_mc_to_kernel);
+
+unsigned long __must_check copy_mc_to_user(void *dst, const void *src, unsigned len)
+{
+ unsigned long ret;
+
+ if (!copy_mc_fragile_enabled)
+ return copy_user_generic(dst, src, len);
+
+ __uaccess_begin();
+ ret = copy_mc_fragile(dst, src, len);
+ __uaccess_end();
+ return ret;
+}
diff --git a/arch/x86/lib/copy_mc_64.S b/arch/x86/lib/copy_mc_64.S
new file mode 100644
index 000000000000..c3b613c4544a
--- /dev/null
+++ b/arch/x86/lib/copy_mc_64.S
@@ -0,0 +1,127 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* Copyright(c) 2016-2020 Intel Corporation. All rights reserved. */
+
+#include <linux/linkage.h>
+#include <asm/copy_mc_test.h>
+#include <asm/export.h>
+#include <asm/asm.h>
+
+#ifndef CONFIG_UML
+
+#ifdef CONFIG_X86_MCE
+COPY_MC_TEST_CTL
+
+/*
+ * copy_mc_fragile - copy memory with indication if an exception / fault happened
+ *
+ * The 'fragile' version is opted into by platform quirks and takes
+ * pains to avoid unrecoverable corner cases like 'fast-string'
+ * instruction sequences, and consuming poison across a cacheline
+ * boundary. The non-fragile version is equivalent to memcpy()
+ * regardless of CPU machine-check-recovery capability.
+ */
+SYM_FUNC_START(copy_mc_fragile)
+ cmpl $8, %edx
+ /* Less than 8 bytes? Go to byte copy loop */
+ jb .L_no_whole_words
+
+ /* Check for bad alignment of source */
+ testl $7, %esi
+ /* Already aligned */
+ jz .L_8byte_aligned
+
+ /* Copy one byte at a time until source is 8-byte aligned */
+ movl %esi, %ecx
+ andl $7, %ecx
+ subl $8, %ecx
+ negl %ecx
+ subl %ecx, %edx
+.L_read_leading_bytes:
+ movb (%rsi), %al
+ COPY_MC_TEST_SRC %rsi 1 .E_leading_bytes
+ COPY_MC_TEST_DST %rdi 1 .E_leading_bytes
+.L_write_leading_bytes:
+ movb %al, (%rdi)
+ incq %rsi
+ incq %rdi
+ decl %ecx
+ jnz .L_read_leading_bytes
+
+.L_8byte_aligned:
+ movl %edx, %ecx
+ andl $7, %edx
+ shrl $3, %ecx
+ jz .L_no_whole_words
+
+.L_read_words:
+ movq (%rsi), %r8
+ COPY_MC_TEST_SRC %rsi 8 .E_read_words
+ COPY_MC_TEST_DST %rdi 8 .E_write_words
+.L_write_words:
+ movq %r8, (%rdi)
+ addq $8, %rsi
+ addq $8, %rdi
+ decl %ecx
+ jnz .L_read_words
+
+ /* Any trailing bytes? */
+.L_no_whole_words:
+ andl %edx, %edx
+ jz .L_done_memcpy_trap
+
+ /* Copy trailing bytes */
+ movl %edx, %ecx
+.L_read_trailing_bytes:
+ movb (%rsi), %al
+ COPY_MC_TEST_SRC %rsi 1 .E_trailing_bytes
+ COPY_MC_TEST_DST %rdi 1 .E_trailing_bytes
+.L_write_trailing_bytes:
+ movb %al, (%rdi)
+ incq %rsi
+ incq %rdi
+ decl %ecx
+ jnz .L_read_trailing_bytes
+
+ /* Copy successful. Return zero */
+.L_done_memcpy_trap:
+ xorl %eax, %eax
+.L_done:
+ ret
+SYM_FUNC_END(copy_mc_fragile)
+EXPORT_SYMBOL_GPL(copy_mc_fragile)
+
+ .section .fixup, "ax"
+ /*
+ * Return number of bytes not copied for any failure. Note that
+ * there is no "tail" handling since the source buffer is 8-byte
+ * aligned and poison is cacheline aligned.
+ */
+.E_read_words:
+ shll $3, %ecx
+.E_leading_bytes:
+ addl %edx, %ecx
+.E_trailing_bytes:
+ mov %ecx, %eax
+ jmp .L_done
+
+ /*
+ * For write fault handling, given the destination is unaligned,
+ * we handle faults on multi-byte writes with a byte-by-byte
+ * copy up to the write-protected page.
+ */
+.E_write_words:
+ shll $3, %ecx
+ addl %edx, %ecx
+ movl %ecx, %edx
+ jmp copy_mc_fragile_handle_tail
+
+ .previous
+
+ _ASM_EXTABLE_FAULT(.L_read_leading_bytes, .E_leading_bytes)
+ _ASM_EXTABLE_FAULT(.L_read_words, .E_read_words)
+ _ASM_EXTABLE_FAULT(.L_read_trailing_bytes, .E_trailing_bytes)
+ _ASM_EXTABLE(.L_write_leading_bytes, .E_leading_bytes)
+ _ASM_EXTABLE(.L_write_words, .E_write_words)
+ _ASM_EXTABLE(.L_write_trailing_bytes, .E_trailing_bytes)
+#endif /* CONFIG_X86_MCE */
+#endif /* !CONFIG_UML */
diff --git a/arch/x86/lib/memcpy_64.S b/arch/x86/lib/memcpy_64.S
index bbcc05bcefad..037faac46b0c 100644
--- a/arch/x86/lib/memcpy_64.S
+++ b/arch/x86/lib/memcpy_64.S
@@ -4,7 +4,6 @@
#include <linux/linkage.h>
#include <asm/errno.h>
#include <asm/cpufeatures.h>
-#include <asm/mcsafe_test.h>
#include <asm/alternative-asm.h>
#include <asm/export.h>
@@ -187,117 +186,3 @@ SYM_FUNC_START_LOCAL(memcpy_orig)
SYM_FUNC_END(memcpy_orig)
.popsection
-
-#ifndef CONFIG_UML
-
-MCSAFE_TEST_CTL
-
-/*
- * __memcpy_mcsafe - memory copy with machine check exception handling
- * Note that we only catch machine checks when reading the source addresses.
- * Writes to target are posted and don't generate machine checks.
- */
-SYM_FUNC_START(__memcpy_mcsafe)
- cmpl $8, %edx
- /* Less than 8 bytes? Go to byte copy loop */
- jb .L_no_whole_words
-
- /* Check for bad alignment of source */
- testl $7, %esi
- /* Already aligned */
- jz .L_8byte_aligned
-
- /* Copy one byte at a time until source is 8-byte aligned */
- movl %esi, %ecx
- andl $7, %ecx
- subl $8, %ecx
- negl %ecx
- subl %ecx, %edx
-.L_read_leading_bytes:
- movb (%rsi), %al
- MCSAFE_TEST_SRC %rsi 1 .E_leading_bytes
- MCSAFE_TEST_DST %rdi 1 .E_leading_bytes
-.L_write_leading_bytes:
- movb %al, (%rdi)
- incq %rsi
- incq %rdi
- decl %ecx
- jnz .L_read_leading_bytes
-
-.L_8byte_aligned:
- movl %edx, %ecx
- andl $7, %edx
- shrl $3, %ecx
- jz .L_no_whole_words
-
-.L_read_words:
- movq (%rsi), %r8
- MCSAFE_TEST_SRC %rsi 8 .E_read_words
- MCSAFE_TEST_DST %rdi 8 .E_write_words
-.L_write_words:
- movq %r8, (%rdi)
- addq $8, %rsi
- addq $8, %rdi
- decl %ecx
- jnz .L_read_words
-
- /* Any trailing bytes? */
-.L_no_whole_words:
- andl %edx, %edx
- jz .L_done_memcpy_trap
-
- /* Copy trailing bytes */
- movl %edx, %ecx
-.L_read_trailing_bytes:
- movb (%rsi), %al
- MCSAFE_TEST_SRC %rsi 1 .E_trailing_bytes
- MCSAFE_TEST_DST %rdi 1 .E_trailing_bytes
-.L_write_trailing_bytes:
- movb %al, (%rdi)
- incq %rsi
- incq %rdi
- decl %ecx
- jnz .L_read_trailing_bytes
-
- /* Copy successful. Return zero */
-.L_done_memcpy_trap:
- xorl %eax, %eax
-.L_done:
- ret
-SYM_FUNC_END(__memcpy_mcsafe)
-EXPORT_SYMBOL_GPL(__memcpy_mcsafe)
-
- .section .fixup, "ax"
- /*
- * Return number of bytes not copied for any failure. Note that
- * there is no "tail" handling since the source buffer is 8-byte
- * aligned and poison is cacheline aligned.
- */
-.E_read_words:
- shll $3, %ecx
-.E_leading_bytes:
- addl %edx, %ecx
-.E_trailing_bytes:
- mov %ecx, %eax
- jmp .L_done
-
- /*
- * For write fault handling, given the destination is unaligned,
- * we handle faults on multi-byte writes with a byte-by-byte
- * copy up to the write-protected page.
- */
-.E_write_words:
- shll $3, %ecx
- addl %edx, %ecx
- movl %ecx, %edx
- jmp mcsafe_handle_tail
-
- .previous
-
- _ASM_EXTABLE_FAULT(.L_read_leading_bytes, .E_leading_bytes)
- _ASM_EXTABLE_FAULT(.L_read_words, .E_read_words)
- _ASM_EXTABLE_FAULT(.L_read_trailing_bytes, .E_trailing_bytes)
- _ASM_EXTABLE(.L_write_leading_bytes, .E_leading_bytes)
- _ASM_EXTABLE(.L_write_words, .E_write_words)
- _ASM_EXTABLE(.L_write_trailing_bytes, .E_trailing_bytes)
-#endif
diff --git a/arch/x86/lib/usercopy_64.c b/arch/x86/lib/usercopy_64.c
index b0dfac3d3df7..5f1d4a9ebd5a 100644
--- a/arch/x86/lib/usercopy_64.c
+++ b/arch/x86/lib/usercopy_64.c
@@ -56,27 +56,6 @@ unsigned long clear_user(void __user *to, unsigned long n)
}
EXPORT_SYMBOL(clear_user);
-/*
- * Similar to copy_user_handle_tail, probe for the write fault point,
- * but reuse __memcpy_mcsafe in case a new read error is encountered.
- * clac() is handled in _copy_to_iter_mcsafe().
- */
-__visible notrace unsigned long
-mcsafe_handle_tail(char *to, char *from, unsigned len)
-{
- for (; len; --len, to++, from++) {
- /*
- * Call the assembly routine back directly since
- * memcpy_mcsafe() may silently fallback to memcpy.
- */
- unsigned long rem = __memcpy_mcsafe(to, from, 1);
-
- if (rem)
- break;
- }
- return len;
-}
-
#ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE
/**
* clean_cache_range - write back a cache range with CLWB
diff --git a/drivers/md/dm-writecache.c b/drivers/md/dm-writecache.c
index 86dbe0c8b45c..9fc18fadacc6 100644
--- a/drivers/md/dm-writecache.c
+++ b/drivers/md/dm-writecache.c
@@ -49,7 +49,7 @@ do { \
#define pmem_assign(dest, src) ((dest) = (src))
#endif
-#if defined(__HAVE_ARCH_MEMCPY_MCSAFE) && defined(DM_WRITECACHE_HAS_PMEM)
+#if IS_ENABLED(CONFIG_ARCH_HAS_COPY_MC) && defined(DM_WRITECACHE_HAS_PMEM)
#define DM_WRITECACHE_HANDLE_HARDWARE_ERRORS
#endif
@@ -984,7 +984,8 @@ static void writecache_resume(struct dm_target *ti)
}
wc->freelist_size = 0;
- r = memcpy_mcsafe(&sb_seq_count, &sb(wc)->seq_count, sizeof(uint64_t));
+ r = copy_mc_to_kernel(&sb_seq_count, &sb(wc)->seq_count,
+ sizeof(uint64_t));
if (r) {
writecache_error(wc, r, "hardware memory error when reading superblock: %d", r);
sb_seq_count = cpu_to_le64(0);
@@ -1000,7 +1001,8 @@ static void writecache_resume(struct dm_target *ti)
e->seq_count = -1;
continue;
}
- r = memcpy_mcsafe(&wme, memory_entry(wc, e), sizeof(struct wc_memory_entry));
+ r = copy_mc_to_kernel(&wme, memory_entry(wc, e),
+ sizeof(struct wc_memory_entry));
if (r) {
writecache_error(wc, r, "hardware memory error when reading metadata entry %lu: %d",
(unsigned long)b, r);
@@ -1198,7 +1200,7 @@ static void bio_copy_block(struct dm_writecache *wc, struct bio *bio, void *data
if (rw == READ) {
int r;
- r = memcpy_mcsafe(buf, data, size);
+ r = copy_mc_to_kernel(buf, data, size);
flush_dcache_page(bio_page(bio));
if (unlikely(r)) {
writecache_error(wc, r, "hardware memory error when reading data: %d", r);
@@ -2341,7 +2343,7 @@ static int writecache_ctr(struct dm_target *ti, unsigned argc, char **argv)
}
}
- r = memcpy_mcsafe(&s, sb(wc), sizeof(struct wc_memory_superblock));
+ r = copy_mc_to_kernel(&s, sb(wc), sizeof(struct wc_memory_superblock));
if (r) {
ti->error = "Hardware memory error when reading superblock";
goto bad;
@@ -2352,7 +2354,8 @@ static int writecache_ctr(struct dm_target *ti, unsigned argc, char **argv)
ti->error = "Unable to initialize device";
goto bad;
}
- r = memcpy_mcsafe(&s, sb(wc), sizeof(struct wc_memory_superblock));
+ r = copy_mc_to_kernel(&s, sb(wc),
+ sizeof(struct wc_memory_superblock));
if (r) {
ti->error = "Hardware memory error when reading superblock";
goto bad;
diff --git a/drivers/nvdimm/claim.c b/drivers/nvdimm/claim.c
index 45964acba944..22d865ba6353 100644
--- a/drivers/nvdimm/claim.c
+++ b/drivers/nvdimm/claim.c
@@ -268,7 +268,7 @@ static int nsio_rw_bytes(struct nd_namespace_common *ndns,
if (rw == READ) {
if (unlikely(is_bad_pmem(&nsio->bb, sector, sz_align)))
return -EIO;
- if (memcpy_mcsafe(buf, nsio->addr + offset, size) != 0)
+ if (copy_mc_to_kernel(buf, nsio->addr + offset, size) != 0)
return -EIO;
return 0;
}
diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index fab29b514372..5c6939e004e2 100644
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c
@@ -125,7 +125,7 @@ static blk_status_t read_pmem(struct page *page, unsigned int off,
while (len) {
mem = kmap_atomic(page);
chunk = min_t(unsigned int, len, PAGE_SIZE - off);
- rem = memcpy_mcsafe(mem + off, pmem_addr, chunk);
+ rem = copy_mc_to_kernel(mem + off, pmem_addr, chunk);
kunmap_atomic(mem);
if (rem)
return BLK_STS_IOERR;
@@ -304,7 +304,7 @@ static long pmem_dax_direct_access(struct dax_device *dax_dev,
/*
* Use the 'no check' versions of copy_from_iter_flushcache() and
- * copy_to_iter_mcsafe() to bypass HARDENED_USERCOPY overhead. Bounds
+ * copy_mc_to_iter() to bypass HARDENED_USERCOPY overhead. Bounds
* checking, both file offset and device offset, is handled by
* dax_iomap_actor()
*/
@@ -317,7 +317,7 @@ static size_t pmem_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff,
static size_t pmem_copy_to_iter(struct dax_device *dax_dev, pgoff_t pgoff,
void *addr, size_t bytes, struct iov_iter *i)
{
- return _copy_to_iter_mcsafe(addr, bytes, i);
+ return _copy_mc_to_iter(addr, bytes, i);
}
static const struct dax_operations pmem_dax_ops = {
diff --git a/include/linux/string.h b/include/linux/string.h
index 9b7a0632e87a..b1f3894a0a3e 100644
--- a/include/linux/string.h
+++ b/include/linux/string.h
@@ -161,20 +161,13 @@ extern int bcmp(const void *,const void *,__kernel_size_t);
#ifndef __HAVE_ARCH_MEMCHR
extern void * memchr(const void *,int,__kernel_size_t);
#endif
-#ifndef __HAVE_ARCH_MEMCPY_MCSAFE
-static inline __must_check unsigned long memcpy_mcsafe(void *dst,
- const void *src, size_t cnt)
-{
- memcpy(dst, src, cnt);
- return 0;
-}
-#endif
#ifndef __HAVE_ARCH_MEMCPY_FLUSHCACHE
static inline void memcpy_flushcache(void *dst, const void *src, size_t cnt)
{
memcpy(dst, src, cnt);
}
#endif
+
void *memchr_inv(const void *s, int c, size_t n);
char *strreplace(char *s, char old, char new);
diff --git a/include/linux/uaccess.h b/include/linux/uaccess.h
index 94b285411659..1ae36bc8db35 100644
--- a/include/linux/uaccess.h
+++ b/include/linux/uaccess.h
@@ -179,6 +179,19 @@ copy_in_user(void __user *to, const void __user *from, unsigned long n)
}
#endif
+#ifndef copy_mc_to_kernel
+/*
+ * Without arch opt-in this generic copy_mc_to_kernel() will not handle
+ * #MC (or arch equivalent) during source read.
+ */
+static inline unsigned long __must_check
+copy_mc_to_kernel(void *dst, const void *src, size_t cnt)
+{
+ memcpy(dst, src, cnt);
+ return 0;
+}
+#endif
+
static __always_inline void pagefault_disabled_inc(void)
{
current->pagefault_disabled++;
diff --git a/include/linux/uio.h b/include/linux/uio.h
index 3835a8a8e9ea..f14410c678bd 100644
--- a/include/linux/uio.h
+++ b/include/linux/uio.h
@@ -185,10 +185,10 @@ size_t _copy_from_iter_flushcache(void *addr, size_t bytes, struct iov_iter *i);
#define _copy_from_iter_flushcache _copy_from_iter_nocache
#endif
-#ifdef CONFIG_ARCH_HAS_UACCESS_MCSAFE
-size_t _copy_to_iter_mcsafe(const void *addr, size_t bytes, struct iov_iter *i);
+#ifdef CONFIG_ARCH_HAS_COPY_MC
+size_t _copy_mc_to_iter(const void *addr, size_t bytes, struct iov_iter *i);
#else
-#define _copy_to_iter_mcsafe _copy_to_iter
+#define _copy_mc_to_iter _copy_to_iter
#endif
static __always_inline __must_check
@@ -201,12 +201,12 @@ size_t copy_from_iter_flushcache(void *addr, size_t bytes, struct iov_iter *i)
}
static __always_inline __must_check
-size_t copy_to_iter_mcsafe(void *addr, size_t bytes, struct iov_iter *i)
+size_t copy_mc_to_iter(void *addr, size_t bytes, struct iov_iter *i)
{
if (unlikely(!check_copy_size(addr, bytes, true)))
return 0;
else
- return _copy_to_iter_mcsafe(addr, bytes, i);
+ return _copy_mc_to_iter(addr, bytes, i);
}
size_t iov_iter_zero(size_t bytes, struct iov_iter *);
diff --git a/lib/Kconfig b/lib/Kconfig
index b4b98a03ff98..b46a9fd122c8 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -635,7 +635,12 @@ config UACCESS_MEMCPY
config ARCH_HAS_UACCESS_FLUSHCACHE
bool
-config ARCH_HAS_UACCESS_MCSAFE
+# arch has a concept of a recoverable synchronous exception due to a
+# memory-read error like x86 machine-check or ARM data-abort, and
+# implements copy_mc_to_{user,kernel} to abort and report
+# 'bytes-transferred' if that exception fires when accessing the source
+# buffer.
+config ARCH_HAS_COPY_MC
bool
# Temporary. Goes away when all archs are cleaned up
diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index 5e40786c8f12..d13304a034f5 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -637,30 +637,30 @@ size_t _copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i)
}
EXPORT_SYMBOL(_copy_to_iter);
-#ifdef CONFIG_ARCH_HAS_UACCESS_MCSAFE
-static int copyout_mcsafe(void __user *to, const void *from, size_t n)
+#ifdef CONFIG_ARCH_HAS_COPY_MC
+static int copyout_mc(void __user *to, const void *from, size_t n)
{
if (access_ok(to, n)) {
instrument_copy_to_user(to, from, n);
- n = copy_to_user_mcsafe((__force void *) to, from, n);
+ n = copy_mc_to_user((__force void *) to, from, n);
}
return n;
}
-static unsigned long memcpy_mcsafe_to_page(struct page *page, size_t offset,
+static unsigned long copy_mc_to_page(struct page *page, size_t offset,
const char *from, size_t len)
{
unsigned long ret;
char *to;
to = kmap_atomic(page);
- ret = memcpy_mcsafe(to + offset, from, len);
+ ret = copy_mc_to_kernel(to + offset, from, len);
kunmap_atomic(to);
return ret;
}
-static size_t copy_pipe_to_iter_mcsafe(const void *addr, size_t bytes,
+static size_t copy_mc_pipe_to_iter(const void *addr, size_t bytes,
struct iov_iter *i)
{
struct pipe_inode_info *pipe = i->pipe;
@@ -678,7 +678,7 @@ static size_t copy_pipe_to_iter_mcsafe(const void *addr, size_t bytes,
size_t chunk = min_t(size_t, n, PAGE_SIZE - off);
unsigned long rem;
- rem = memcpy_mcsafe_to_page(pipe->bufs[i_head & p_mask].page,
+ rem = copy_mc_to_page(pipe->bufs[i_head & p_mask].page,
off, addr, chunk);
i->head = i_head;
i->iov_offset = off + chunk - rem;
@@ -695,18 +695,17 @@ static size_t copy_pipe_to_iter_mcsafe(const void *addr, size_t bytes,
}
/**
- * _copy_to_iter_mcsafe - copy to user with source-read error exception handling
+ * _copy_mc_to_iter - copy to iter with source memory error exception handling
* @addr: source kernel address
* @bytes: total transfer length
* @iter: destination iterator
*
- * The pmem driver arranges for filesystem-dax to use this facility via
- * dax_copy_to_iter() for protecting read/write to persistent memory.
- * Unless / until an architecture can guarantee identical performance
- * between _copy_to_iter_mcsafe() and _copy_to_iter() it would be a
- * performance regression to switch more users to the mcsafe version.
+ * The pmem driver deploys this for the dax operation
+ * (dax_copy_to_iter()) for dax reads (bypass page-cache and the
+ * block-layer). Upon #MC read(2) aborts and returns EIO or the bytes
+ * successfully copied.
*
- * Otherwise, the main differences between this and typical _copy_to_iter().
+ * The main differences between this and typical _copy_to_iter().
*
* * Typical tail/residue handling after a fault retries the copy
* byte-by-byte until the fault happens again. Re-triggering machine
@@ -717,23 +716,22 @@ static size_t copy_pipe_to_iter_mcsafe(const void *addr, size_t bytes,
* * ITER_KVEC, ITER_PIPE, and ITER_BVEC can return short copies.
* Compare to copy_to_iter() where only ITER_IOVEC attempts might return
* a short copy.
- *
- * See MCSAFE_TEST for self-test.
*/
-size_t _copy_to_iter_mcsafe(const void *addr, size_t bytes, struct iov_iter *i)
+size_t _copy_mc_to_iter(const void *addr, size_t bytes, struct iov_iter *i)
{
const char *from = addr;
unsigned long rem, curr_addr, s_addr = (unsigned long) addr;
if (unlikely(iov_iter_is_pipe(i)))
- return copy_pipe_to_iter_mcsafe(addr, bytes, i);
+ return copy_mc_pipe_to_iter(addr, bytes, i);
if (iter_is_iovec(i))
might_fault();
iterate_and_advance(i, bytes, v,
- copyout_mcsafe(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len),
+ copyout_mc(v.iov_base, (from += v.iov_len) - v.iov_len,
+ v.iov_len),
({
- rem = memcpy_mcsafe_to_page(v.bv_page, v.bv_offset,
- (from += v.bv_len) - v.bv_len, v.bv_len);
+ rem = copy_mc_to_page(v.bv_page, v.bv_offset,
+ (from += v.bv_len) - v.bv_len, v.bv_len);
if (rem) {
curr_addr = (unsigned long) from;
bytes = curr_addr - s_addr - rem;
@@ -741,8 +739,8 @@ size_t _copy_to_iter_mcsafe(const void *addr, size_t bytes, struct iov_iter *i)
}
}),
({
- rem = memcpy_mcsafe(v.iov_base, (from += v.iov_len) - v.iov_len,
- v.iov_len);
+ rem = copy_mc_to_kernel(v.iov_base, (from += v.iov_len)
+ - v.iov_len, v.iov_len);
if (rem) {
curr_addr = (unsigned long) from;
bytes = curr_addr - s_addr - rem;
@@ -753,8 +751,8 @@ size_t _copy_to_iter_mcsafe(const void *addr, size_t bytes, struct iov_iter *i)
return bytes;
}
-EXPORT_SYMBOL_GPL(_copy_to_iter_mcsafe);
-#endif /* CONFIG_ARCH_HAS_UACCESS_MCSAFE */
+EXPORT_SYMBOL_GPL(_copy_mc_to_iter);
+#endif /* CONFIG_ARCH_HAS_COPY_MC */
size_t _copy_from_iter(void *addr, size_t bytes, struct iov_iter *i)
{
diff --git a/tools/arch/x86/include/asm/mcsafe_test.h b/tools/arch/x86/include/asm/mcsafe_test.h
deleted file mode 100644
index 2ccd588fbad4..000000000000
--- a/tools/arch/x86/include/asm/mcsafe_test.h
+++ /dev/null
@@ -1,13 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef _MCSAFE_TEST_H_
-#define _MCSAFE_TEST_H_
-
-.macro MCSAFE_TEST_CTL
-.endm
-
-.macro MCSAFE_TEST_SRC reg count target
-.endm
-
-.macro MCSAFE_TEST_DST reg count target
-.endm
-#endif /* _MCSAFE_TEST_H_ */
diff --git a/tools/arch/x86/lib/memcpy_64.S b/tools/arch/x86/lib/memcpy_64.S
index 45f8e1b02241..0b5b8ae56bd9 100644
--- a/tools/arch/x86/lib/memcpy_64.S
+++ b/tools/arch/x86/lib/memcpy_64.S
@@ -4,7 +4,6 @@
#include <linux/linkage.h>
#include <asm/errno.h>
#include <asm/cpufeatures.h>
-#include <asm/mcsafe_test.h>
#include <asm/alternative-asm.h>
#include <asm/export.h>
@@ -187,117 +186,3 @@ SYM_FUNC_START(memcpy_orig)
SYM_FUNC_END(memcpy_orig)
.popsection
-
-#ifndef CONFIG_UML
-
-MCSAFE_TEST_CTL
-
-/*
- * __memcpy_mcsafe - memory copy with machine check exception handling
- * Note that we only catch machine checks when reading the source addresses.
- * Writes to target are posted and don't generate machine checks.
- */
-SYM_FUNC_START(__memcpy_mcsafe)
- cmpl $8, %edx
- /* Less than 8 bytes? Go to byte copy loop */
- jb .L_no_whole_words
-
- /* Check for bad alignment of source */
- testl $7, %esi
- /* Already aligned */
- jz .L_8byte_aligned
-
- /* Copy one byte at a time until source is 8-byte aligned */
- movl %esi, %ecx
- andl $7, %ecx
- subl $8, %ecx
- negl %ecx
- subl %ecx, %edx
-.L_read_leading_bytes:
- movb (%rsi), %al
- MCSAFE_TEST_SRC %rsi 1 .E_leading_bytes
- MCSAFE_TEST_DST %rdi 1 .E_leading_bytes
-.L_write_leading_bytes:
- movb %al, (%rdi)
- incq %rsi
- incq %rdi
- decl %ecx
- jnz .L_read_leading_bytes
-
-.L_8byte_aligned:
- movl %edx, %ecx
- andl $7, %edx
- shrl $3, %ecx
- jz .L_no_whole_words
-
-.L_read_words:
- movq (%rsi), %r8
- MCSAFE_TEST_SRC %rsi 8 .E_read_words
- MCSAFE_TEST_DST %rdi 8 .E_write_words
-.L_write_words:
- movq %r8, (%rdi)
- addq $8, %rsi
- addq $8, %rdi
- decl %ecx
- jnz .L_read_words
-
- /* Any trailing bytes? */
-.L_no_whole_words:
- andl %edx, %edx
- jz .L_done_memcpy_trap
-
- /* Copy trailing bytes */
- movl %edx, %ecx
-.L_read_trailing_bytes:
- movb (%rsi), %al
- MCSAFE_TEST_SRC %rsi 1 .E_trailing_bytes
- MCSAFE_TEST_DST %rdi 1 .E_trailing_bytes
-.L_write_trailing_bytes:
- movb %al, (%rdi)
- incq %rsi
- incq %rdi
- decl %ecx
- jnz .L_read_trailing_bytes
-
- /* Copy successful. Return zero */
-.L_done_memcpy_trap:
- xorl %eax, %eax
-.L_done:
- ret
-SYM_FUNC_END(__memcpy_mcsafe)
-EXPORT_SYMBOL_GPL(__memcpy_mcsafe)
-
- .section .fixup, "ax"
- /*
- * Return number of bytes not copied for any failure. Note that
- * there is no "tail" handling since the source buffer is 8-byte
- * aligned and poison is cacheline aligned.
- */
-.E_read_words:
- shll $3, %ecx
-.E_leading_bytes:
- addl %edx, %ecx
-.E_trailing_bytes:
- mov %ecx, %eax
- jmp .L_done
-
- /*
- * For write fault handling, given the destination is unaligned,
- * we handle faults on multi-byte writes with a byte-by-byte
- * copy up to the write-protected page.
- */
-.E_write_words:
- shll $3, %ecx
- addl %edx, %ecx
- movl %ecx, %edx
- jmp mcsafe_handle_tail
-
- .previous
-
- _ASM_EXTABLE_FAULT(.L_read_leading_bytes, .E_leading_bytes)
- _ASM_EXTABLE_FAULT(.L_read_words, .E_read_words)
- _ASM_EXTABLE_FAULT(.L_read_trailing_bytes, .E_trailing_bytes)
- _ASM_EXTABLE(.L_write_leading_bytes, .E_leading_bytes)
- _ASM_EXTABLE(.L_write_words, .E_write_words)
- _ASM_EXTABLE(.L_write_trailing_bytes, .E_trailing_bytes)
-#endif
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index e034a8f24f46..893f021fec63 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -548,8 +548,8 @@ static const char *uaccess_safe_builtin[] = {
"__ubsan_handle_shift_out_of_bounds",
/* misc */
"csum_partial_copy_generic",
- "__memcpy_mcsafe",
- "mcsafe_handle_tail",
+ "copy_mc_fragile",
+ "copy_mc_fragile_handle_tail",
"ftrace_likely_update", /* CONFIG_TRACE_BRANCH_PROFILING */
NULL
};
diff --git a/tools/perf/bench/Build b/tools/perf/bench/Build
index dd68a40a790c..878db6a59a41 100644
--- a/tools/perf/bench/Build
+++ b/tools/perf/bench/Build
@@ -13,7 +13,6 @@ perf-y += synthesize.o
perf-y += kallsyms-parse.o
perf-y += find-bit-bench.o
-perf-$(CONFIG_X86_64) += mem-memcpy-x86-64-lib.o
perf-$(CONFIG_X86_64) += mem-memcpy-x86-64-asm.o
perf-$(CONFIG_X86_64) += mem-memset-x86-64-asm.o
diff --git a/tools/perf/bench/mem-memcpy-x86-64-lib.c b/tools/perf/bench/mem-memcpy-x86-64-lib.c
deleted file mode 100644
index 4130734dde84..000000000000
--- a/tools/perf/bench/mem-memcpy-x86-64-lib.c
+++ /dev/null
@@ -1,24 +0,0 @@
-/*
- * From code in arch/x86/lib/usercopy_64.c, copied to keep tools/ copy
- * of the kernel's arch/x86/lib/memcpy_64.s used in 'perf bench mem memcpy'
- * happy.
- */
-#include <linux/types.h>
-
-unsigned long __memcpy_mcsafe(void *dst, const void *src, size_t cnt);
-unsigned long mcsafe_handle_tail(char *to, char *from, unsigned len);
-
-unsigned long mcsafe_handle_tail(char *to, char *from, unsigned len)
-{
- for (; len; --len, to++, from++) {
- /*
- * Call the assembly routine back directly since
- * memcpy_mcsafe() may silently fallback to memcpy.
- */
- unsigned long rem = __memcpy_mcsafe(to, from, 1);
-
- if (rem)
- break;
- }
- return len;
-}
diff --git a/tools/testing/nvdimm/test/nfit.c b/tools/testing/nvdimm/test/nfit.c
index a1a5dc645b40..2ac0fff6dad8 100644
--- a/tools/testing/nvdimm/test/nfit.c
+++ b/tools/testing/nvdimm/test/nfit.c
@@ -23,7 +23,8 @@
#include "nfit_test.h"
#include "../watermark.h"
-#include <asm/mcsafe_test.h>
+#include <asm/copy_mc_test.h>
+#include <asm/mce.h>
/*
* Generate an NFIT table to describe the following topology:
@@ -3283,7 +3284,7 @@ static struct platform_driver nfit_test_driver = {
.id_table = nfit_test_id,
};
-static char mcsafe_buf[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE)));
+static char copy_mc_buf[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE)));
enum INJECT {
INJECT_NONE,
@@ -3291,7 +3292,7 @@ enum INJECT {
INJECT_DST,
};
-static void mcsafe_test_init(char *dst, char *src, size_t size)
+static void copy_mc_test_init(char *dst, char *src, size_t size)
{
size_t i;
@@ -3300,7 +3301,7 @@ static void mcsafe_test_init(char *dst, char *src, size_t size)
src[i] = (char) i;
}
-static bool mcsafe_test_validate(unsigned char *dst, unsigned char *src,
+static bool copy_mc_test_validate(unsigned char *dst, unsigned char *src,
size_t size, unsigned long rem)
{
size_t i;
@@ -3321,12 +3322,12 @@ static bool mcsafe_test_validate(unsigned char *dst, unsigned char *src,
return true;
}
-void mcsafe_test(void)
+void copy_mc_test(void)
{
char *inject_desc[] = { "none", "source", "destination" };
enum INJECT inj;
- if (IS_ENABLED(CONFIG_MCSAFE_TEST)) {
+ if (IS_ENABLED(CONFIG_COPY_MC_TEST)) {
pr_info("%s: run...\n", __func__);
} else {
pr_info("%s: disabled, skip.\n", __func__);
@@ -3344,31 +3345,31 @@ void mcsafe_test(void)
switch (inj) {
case INJECT_NONE:
- mcsafe_inject_src(NULL);
- mcsafe_inject_dst(NULL);
- dst = &mcsafe_buf[2048];
- src = &mcsafe_buf[1024 - i];
+ copy_mc_inject_src(NULL);
+ copy_mc_inject_dst(NULL);
+ dst = ©_mc_buf[2048];
+ src = ©_mc_buf[1024 - i];
expect = 0;
break;
case INJECT_SRC:
- mcsafe_inject_src(&mcsafe_buf[1024]);
- mcsafe_inject_dst(NULL);
- dst = &mcsafe_buf[2048];
- src = &mcsafe_buf[1024 - i];
+ copy_mc_inject_src(©_mc_buf[1024]);
+ copy_mc_inject_dst(NULL);
+ dst = ©_mc_buf[2048];
+ src = ©_mc_buf[1024 - i];
expect = 512 - i;
break;
case INJECT_DST:
- mcsafe_inject_src(NULL);
- mcsafe_inject_dst(&mcsafe_buf[2048]);
- dst = &mcsafe_buf[2048 - i];
- src = &mcsafe_buf[1024];
+ copy_mc_inject_src(NULL);
+ copy_mc_inject_dst(©_mc_buf[2048]);
+ dst = ©_mc_buf[2048 - i];
+ src = ©_mc_buf[1024];
expect = 512 - i;
break;
}
- mcsafe_test_init(dst, src, 512);
- rem = __memcpy_mcsafe(dst, src, 512);
- valid = mcsafe_test_validate(dst, src, 512, expect);
+ copy_mc_test_init(dst, src, 512);
+ rem = copy_mc_fragile(dst, src, 512);
+ valid = copy_mc_test_validate(dst, src, 512, expect);
if (rem == expect && valid)
continue;
pr_info("%s: copy(%#lx, %#lx, %d) off: %d rem: %ld %s expect: %ld\n",
@@ -3380,8 +3381,8 @@ void mcsafe_test(void)
}
}
- mcsafe_inject_src(NULL);
- mcsafe_inject_dst(NULL);
+ copy_mc_inject_src(NULL);
+ copy_mc_inject_dst(NULL);
}
static __init int nfit_test_init(void)
@@ -3392,7 +3393,7 @@ static __init int nfit_test_init(void)
libnvdimm_test();
acpi_nfit_test();
device_dax_test();
- mcsafe_test();
+ copy_mc_test();
dax_pmem_test();
dax_pmem_core_test();
#ifdef CONFIG_DEV_DAX_PMEM_COMPAT
diff --git a/tools/testing/selftests/powerpc/copyloops/.gitignore b/tools/testing/selftests/powerpc/copyloops/.gitignore
index ddaf140b8255..994b11af765c 100644
--- a/tools/testing/selftests/powerpc/copyloops/.gitignore
+++ b/tools/testing/selftests/powerpc/copyloops/.gitignore
@@ -12,4 +12,4 @@ memcpy_p7_t1
copyuser_64_exc_t0
copyuser_64_exc_t1
copyuser_64_exc_t2
-memcpy_mcsafe_64
+copy_mc_64
diff --git a/tools/testing/selftests/powerpc/copyloops/Makefile b/tools/testing/selftests/powerpc/copyloops/Makefile
index 0917983a1c78..3095b1f1c02b 100644
--- a/tools/testing/selftests/powerpc/copyloops/Makefile
+++ b/tools/testing/selftests/powerpc/copyloops/Makefile
@@ -12,7 +12,7 @@ ASFLAGS = $(CFLAGS) -Wa,-mpower4
TEST_GEN_PROGS := copyuser_64_t0 copyuser_64_t1 copyuser_64_t2 \
copyuser_p7_t0 copyuser_p7_t1 \
memcpy_64_t0 memcpy_64_t1 memcpy_64_t2 \
- memcpy_p7_t0 memcpy_p7_t1 memcpy_mcsafe_64 \
+ memcpy_p7_t0 memcpy_p7_t1 copy_mc_64 \
copyuser_64_exc_t0 copyuser_64_exc_t1 copyuser_64_exc_t2
EXTRA_SOURCES := validate.c ../harness.c stubs.S
@@ -45,9 +45,9 @@ $(OUTPUT)/memcpy_p7_t%: memcpy_power7.S $(EXTRA_SOURCES)
-D SELFTEST_CASE=$(subst memcpy_p7_t,,$(notdir $@)) \
-o $@ $^
-$(OUTPUT)/memcpy_mcsafe_64: memcpy_mcsafe_64.S $(EXTRA_SOURCES)
+$(OUTPUT)/copy_mc_64: copy_mc_64.S $(EXTRA_SOURCES)
$(CC) $(CPPFLAGS) $(CFLAGS) \
- -D COPY_LOOP=test_memcpy_mcsafe \
+ -D COPY_LOOP=test_copy_mc_generic \
-o $@ $^
$(OUTPUT)/copyuser_64_exc_t%: copyuser_64.S exc_validate.c ../harness.c \
diff --git a/tools/testing/selftests/powerpc/copyloops/copy_mc_64.S b/tools/testing/selftests/powerpc/copyloops/copy_mc_64.S
new file mode 120000
index 000000000000..dcbe06d500fb
--- /dev/null
+++ b/tools/testing/selftests/powerpc/copyloops/copy_mc_64.S
@@ -0,0 +1 @@
+../../../../../arch/powerpc/lib/copy_mc_64.S
\ No newline at end of file
diff --git a/tools/testing/selftests/powerpc/copyloops/memcpy_mcsafe_64.S b/tools/testing/selftests/powerpc/copyloops/memcpy_mcsafe_64.S
deleted file mode 120000
index f0feef3062f6..000000000000
--- a/tools/testing/selftests/powerpc/copyloops/memcpy_mcsafe_64.S
+++ /dev/null
@@ -1 +0,0 @@
-../../../../../arch/powerpc/lib/memcpy_mcsafe_64.S
\ No newline at end of file
4 years, 3 months
- 1
- 0
FAILED: patch "[PATCH] arm64: Run ARCH_WORKAROUND_1 enabling code on all CPUs" failed to apply to 4.14-stable tree
by gregkh＠linuxfoundation.org
The patch below does not apply to the 4.14-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 18fce56134c987e5b4eceddafdbe4b00c07e2ae1 Mon Sep 17 00:00:00 2001
From: Marc Zyngier <maz(a)kernel.org>
Date: Thu, 16 Jul 2020 17:11:09 +0100
Subject: [PATCH] arm64: Run ARCH_WORKAROUND_1 enabling code on all CPUs
Commit 73f381660959 ("arm64: Advertise mitigation of Spectre-v2, or lack
thereof") changed the way we deal with ARCH_WORKAROUND_1, by moving most
of the enabling code to the .matches() callback.
This has the unfortunate effect that the workaround gets only enabled on
the first affected CPU, and no other.
In order to address this, forcefully call the .matches() callback from a
.cpu_enable() callback, which brings us back to the original behaviour.
Fixes: 73f381660959 ("arm64: Advertise mitigation of Spectre-v2, or lack thereof")
Cc: <stable(a)vger.kernel.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose(a)arm.com>
Signed-off-by: Marc Zyngier <maz(a)kernel.org>
Signed-off-by: Will Deacon <will(a)kernel.org>
diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c
index 88966496806a..3fe64bf5a58d 100644
--- a/arch/arm64/kernel/cpu_errata.c
+++ b/arch/arm64/kernel/cpu_errata.c
@@ -599,6 +599,12 @@ check_branch_predictor(const struct arm64_cpu_capabilities *entry, int scope)
return (need_wa > 0);
}
+static void
+cpu_enable_branch_predictor_hardening(const struct arm64_cpu_capabilities *cap)
+{
+ cap->matches(cap, SCOPE_LOCAL_CPU);
+}
+
static const __maybe_unused struct midr_range tx2_family_cpus[] = {
MIDR_ALL_VERSIONS(MIDR_BRCM_VULCAN),
MIDR_ALL_VERSIONS(MIDR_CAVIUM_THUNDERX2),
@@ -890,9 +896,11 @@ const struct arm64_cpu_capabilities arm64_errata[] = {
},
#endif
{
+ .desc = "Branch predictor hardening",
.capability = ARM64_HARDEN_BRANCH_PREDICTOR,
.type = ARM64_CPUCAP_LOCAL_CPU_ERRATUM,
.matches = check_branch_predictor,
+ .cpu_enable = cpu_enable_branch_predictor_hardening,
},
#ifdef CONFIG_RANDOMIZE_BASE
{
4 years, 3 months
- 1
- 0