This is a note to let you know that I've just added the patch titled
serial: 8250_pci: Add Brainboxes UC-260 4 port serial device
to the 3.18-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum…
The filename of the patch is:
serial-8250_pci-add-brainboxes-uc-260-4-port-serial-device.patch
and it can be found in the queue-3.18 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable(a)vger.kernel.org> know about it.
>From 9f2068f35729948bde84d87a40d135015911345d Mon Sep 17 00:00:00 2001
From: Nikola Ciprich <nikola.ciprich(a)linuxbox.cz>
Date: Tue, 13 Feb 2018 15:04:46 +0100
Subject: serial: 8250_pci: Add Brainboxes UC-260 4 port serial device
From: Nikola Ciprich <nikola.ciprich(a)linuxbox.cz>
commit 9f2068f35729948bde84d87a40d135015911345d upstream.
Add PCI ids for two variants of Brainboxes UC-260 quad port
PCI serial cards.
Suggested-by: Andy Shevchenko <andriy.shevchenko(a)linux.intel.com>
Signed-off-by: Nikola Ciprich <nikola.ciprich(a)linuxbox.cz>
Cc: stable <stable(a)vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
---
drivers/tty/serial/8250/8250_pci.c | 11 +++++++++++
1 file changed, 11 insertions(+)
--- a/drivers/tty/serial/8250/8250_pci.c
+++ b/drivers/tty/serial/8250/8250_pci.c
@@ -4982,6 +4982,17 @@ static struct pci_device_id serial_pci_t
PCI_ANY_ID, PCI_ANY_ID, 0, 0, /* 135a.0dc0 */
pbn_b2_4_115200 },
/*
+ * BrainBoxes UC-260
+ */
+ { PCI_VENDOR_ID_INTASHIELD, 0x0D21,
+ PCI_ANY_ID, PCI_ANY_ID,
+ PCI_CLASS_COMMUNICATION_MULTISERIAL << 8, 0xffff00,
+ pbn_b2_4_115200 },
+ { PCI_VENDOR_ID_INTASHIELD, 0x0E34,
+ PCI_ANY_ID, PCI_ANY_ID,
+ PCI_CLASS_COMMUNICATION_MULTISERIAL << 8, 0xffff00,
+ pbn_b2_4_115200 },
+ /*
* Perle PCI-RAS cards
*/
{ PCI_VENDOR_ID_PLX, PCI_DEVICE_ID_PLX_9030,
Patches currently in stable-queue which might be from nikola.ciprich(a)linuxbox.cz are
queue-3.18/serial-8250_pci-add-brainboxes-uc-260-4-port-serial-device.patch
This is a note to let you know that I've just added the patch titled
x86: Treat R_X86_64_PLT32 as R_X86_64_PC32
to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum…
The filename of the patch is:
x86-treat-r_x86_64_plt32-as-r_x86_64_pc32.patch
and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable(a)vger.kernel.org> know about it.
>From b21ebf2fb4cde1618915a97cc773e287ff49173e Mon Sep 17 00:00:00 2001
From: "H.J. Lu" <hjl.tools(a)gmail.com>
Date: Wed, 7 Feb 2018 14:20:09 -0800
Subject: x86: Treat R_X86_64_PLT32 as R_X86_64_PC32
From: H.J. Lu <hjl.tools(a)gmail.com>
commit b21ebf2fb4cde1618915a97cc773e287ff49173e upstream.
On i386, there are 2 types of PLTs, PIC and non-PIC. PIE and shared
objects must use PIC PLT. To use PIC PLT, you need to load
_GLOBAL_OFFSET_TABLE_ into EBX first. There is no need for that on
x86-64 since x86-64 uses PC-relative PLT.
On x86-64, for 32-bit PC-relative branches, we can generate PLT32
relocation, instead of PC32 relocation, which can also be used as
a marker for 32-bit PC-relative branches. Linker can always reduce
PLT32 relocation to PC32 if function is defined locally. Local
functions should use PC32 relocation. As far as Linux kernel is
concerned, R_X86_64_PLT32 can be treated the same as R_X86_64_PC32
since Linux kernel doesn't use PLT.
R_X86_64_PLT32 for 32-bit PC-relative branches has been enabled in
binutils master branch which will become binutils 2.31.
[ hjl is working on having better documentation on this all, but a few
more notes from him:
"PLT32 relocation is used as marker for PC-relative branches. Because
of EBX, it looks odd to generate PLT32 relocation on i386 when EBX
doesn't have GOT.
As for symbol resolution, PLT32 and PC32 relocations are almost
interchangeable. But when linker sees PLT32 relocation against a
protected symbol, it can resolved locally at link-time since it is
used on a branch instruction. Linker can't do that for PC32
relocation"
but for the kernel use, the two are basically the same, and this
commit gets things building and working with the current binutils
master - Linus ]
Signed-off-by: H.J. Lu <hjl.tools(a)gmail.com>
Signed-off-by: Linus Torvalds <torvalds(a)linux-foundation.org>
Cc: Matthias Kaehlcke <mka(a)chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
---
arch/x86/kernel/machine_kexec_64.c | 1 +
arch/x86/kernel/module.c | 1 +
arch/x86/tools/relocs.c | 3 +++
3 files changed, 5 insertions(+)
--- a/arch/x86/kernel/machine_kexec_64.c
+++ b/arch/x86/kernel/machine_kexec_64.c
@@ -524,6 +524,7 @@ int arch_kexec_apply_relocations_add(con
goto overflow;
break;
case R_X86_64_PC32:
+ case R_X86_64_PLT32:
value -= (u64)address;
*(u32 *)location = value;
break;
--- a/arch/x86/kernel/module.c
+++ b/arch/x86/kernel/module.c
@@ -190,6 +190,7 @@ int apply_relocate_add(Elf64_Shdr *sechd
goto overflow;
break;
case R_X86_64_PC32:
+ case R_X86_64_PLT32:
if (*(u32 *)loc != 0)
goto invalid_relocation;
val -= (u64)loc;
--- a/arch/x86/tools/relocs.c
+++ b/arch/x86/tools/relocs.c
@@ -769,9 +769,12 @@ static int do_reloc64(struct section *se
break;
case R_X86_64_PC32:
+ case R_X86_64_PLT32:
/*
* PC relative relocations don't need to be adjusted unless
* referencing a percpu symbol.
+ *
+ * NB: R_X86_64_PLT32 can be treated as R_X86_64_PC32.
*/
if (is_percpu_sym(sym, symname))
add_reloc(&relocs32neg, offset);
Patches currently in stable-queue which might be from hjl.tools(a)gmail.com are
queue-4.9/x86-treat-r_x86_64_plt32-as-r_x86_64_pc32.patch
This is a note to let you know that I've just added the patch titled
x86/module: Detect and skip invalid relocations
to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum…
The filename of the patch is:
x86-module-detect-and-skip-invalid-relocations.patch
and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable(a)vger.kernel.org> know about it.
>From eda9cec4c9a12208a6f69fbe68f72a6311d50032 Mon Sep 17 00:00:00 2001
From: Josh Poimboeuf <jpoimboe(a)redhat.com>
Date: Fri, 3 Nov 2017 07:58:54 -0500
Subject: x86/module: Detect and skip invalid relocations
From: Josh Poimboeuf <jpoimboe(a)redhat.com>
commit eda9cec4c9a12208a6f69fbe68f72a6311d50032 upstream.
There have been some cases where external tooling (e.g., kpatch-build)
creates a corrupt relocation which targets the wrong address. This is a
silent failure which can corrupt memory in unexpected places.
On x86, the bytes of data being overwritten by relocations are always
initialized to zero beforehand. Use that knowledge to add sanity checks
to detect such cases before they corrupt memory.
Signed-off-by: Josh Poimboeuf <jpoimboe(a)redhat.com>
Cc: Linus Torvalds <torvalds(a)linux-foundation.org>
Cc: Peter Zijlstra <peterz(a)infradead.org>
Cc: Thomas Gleixner <tglx(a)linutronix.de>
Cc: jeyu(a)kernel.org
Cc: live-patching(a)vger.kernel.org
Link: http://lkml.kernel.org/r/37450d6c6225e54db107fba447ce9e56e5f758e9.150971355…
[ Restructured the messages, as it's unclear whether the relocation or the target is corrupted. ]
Signed-off-by: Ingo Molnar <mingo(a)kernel.org>
Cc: Matthias Kaehlcke <mka(a)chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
---
arch/x86/kernel/module.c | 13 +++++++++++++
1 file changed, 13 insertions(+)
--- a/arch/x86/kernel/module.c
+++ b/arch/x86/kernel/module.c
@@ -171,19 +171,27 @@ int apply_relocate_add(Elf64_Shdr *sechd
case R_X86_64_NONE:
break;
case R_X86_64_64:
+ if (*(u64 *)loc != 0)
+ goto invalid_relocation;
*(u64 *)loc = val;
break;
case R_X86_64_32:
+ if (*(u32 *)loc != 0)
+ goto invalid_relocation;
*(u32 *)loc = val;
if (val != *(u32 *)loc)
goto overflow;
break;
case R_X86_64_32S:
+ if (*(s32 *)loc != 0)
+ goto invalid_relocation;
*(s32 *)loc = val;
if ((s64)val != *(s32 *)loc)
goto overflow;
break;
case R_X86_64_PC32:
+ if (*(u32 *)loc != 0)
+ goto invalid_relocation;
val -= (u64)loc;
*(u32 *)loc = val;
#if 0
@@ -199,6 +207,11 @@ int apply_relocate_add(Elf64_Shdr *sechd
}
return 0;
+invalid_relocation:
+ pr_err("x86/modules: Skipping invalid relocation target, existing value is nonzero for type %d, loc %p, val %Lx\n",
+ (int)ELF64_R_TYPE(rel[i].r_info), loc, val);
+ return -ENOEXEC;
+
overflow:
pr_err("overflow in relocation type %d val %Lx\n",
(int)ELF64_R_TYPE(rel[i].r_info), val);
Patches currently in stable-queue which might be from jpoimboe(a)redhat.com are
queue-4.9/x86-boot-objtool-annotate-indirect-jump-in-secondary_startup_64.patch
queue-4.9/x86-module-detect-and-skip-invalid-relocations.patch
queue-4.9/nospec-include-asm-barrier.h-dependency.patch
queue-4.9/x86-speculation-objtool-annotate-indirect-calls-jumps-for-objtool.patch
queue-4.9/x86-paravirt-objtool-annotate-indirect-calls.patch
queue-4.9/nospec-kill-array_index_nospec_mask_check.patch
This is a note to let you know that I've just added the patch titled
x86: Treat R_X86_64_PLT32 as R_X86_64_PC32
to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum…
The filename of the patch is:
x86-treat-r_x86_64_plt32-as-r_x86_64_pc32.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable(a)vger.kernel.org> know about it.
>From b21ebf2fb4cde1618915a97cc773e287ff49173e Mon Sep 17 00:00:00 2001
From: "H.J. Lu" <hjl.tools(a)gmail.com>
Date: Wed, 7 Feb 2018 14:20:09 -0800
Subject: x86: Treat R_X86_64_PLT32 as R_X86_64_PC32
From: H.J. Lu <hjl.tools(a)gmail.com>
commit b21ebf2fb4cde1618915a97cc773e287ff49173e upstream.
On i386, there are 2 types of PLTs, PIC and non-PIC. PIE and shared
objects must use PIC PLT. To use PIC PLT, you need to load
_GLOBAL_OFFSET_TABLE_ into EBX first. There is no need for that on
x86-64 since x86-64 uses PC-relative PLT.
On x86-64, for 32-bit PC-relative branches, we can generate PLT32
relocation, instead of PC32 relocation, which can also be used as
a marker for 32-bit PC-relative branches. Linker can always reduce
PLT32 relocation to PC32 if function is defined locally. Local
functions should use PC32 relocation. As far as Linux kernel is
concerned, R_X86_64_PLT32 can be treated the same as R_X86_64_PC32
since Linux kernel doesn't use PLT.
R_X86_64_PLT32 for 32-bit PC-relative branches has been enabled in
binutils master branch which will become binutils 2.31.
[ hjl is working on having better documentation on this all, but a few
more notes from him:
"PLT32 relocation is used as marker for PC-relative branches. Because
of EBX, it looks odd to generate PLT32 relocation on i386 when EBX
doesn't have GOT.
As for symbol resolution, PLT32 and PC32 relocations are almost
interchangeable. But when linker sees PLT32 relocation against a
protected symbol, it can resolved locally at link-time since it is
used on a branch instruction. Linker can't do that for PC32
relocation"
but for the kernel use, the two are basically the same, and this
commit gets things building and working with the current binutils
master - Linus ]
Signed-off-by: H.J. Lu <hjl.tools(a)gmail.com>
Signed-off-by: Linus Torvalds <torvalds(a)linux-foundation.org>
Cc: Matthias Kaehlcke <mka(a)chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
---
arch/x86/kernel/machine_kexec_64.c | 1 +
arch/x86/kernel/module.c | 1 +
arch/x86/tools/relocs.c | 3 +++
3 files changed, 5 insertions(+)
--- a/arch/x86/kernel/machine_kexec_64.c
+++ b/arch/x86/kernel/machine_kexec_64.c
@@ -519,6 +519,7 @@ int arch_kexec_apply_relocations_add(con
goto overflow;
break;
case R_X86_64_PC32:
+ case R_X86_64_PLT32:
value -= (u64)address;
*(u32 *)location = value;
break;
--- a/arch/x86/kernel/module.c
+++ b/arch/x86/kernel/module.c
@@ -189,6 +189,7 @@ int apply_relocate_add(Elf64_Shdr *sechd
goto overflow;
break;
case R_X86_64_PC32:
+ case R_X86_64_PLT32:
if (*(u32 *)loc != 0)
goto invalid_relocation;
val -= (u64)loc;
--- a/arch/x86/tools/relocs.c
+++ b/arch/x86/tools/relocs.c
@@ -769,9 +769,12 @@ static int do_reloc64(struct section *se
break;
case R_X86_64_PC32:
+ case R_X86_64_PLT32:
/*
* PC relative relocations don't need to be adjusted unless
* referencing a percpu symbol.
+ *
+ * NB: R_X86_64_PLT32 can be treated as R_X86_64_PC32.
*/
if (is_percpu_sym(sym, symname))
add_reloc(&relocs32neg, offset);
Patches currently in stable-queue which might be from hjl.tools(a)gmail.com are
queue-4.4/x86-treat-r_x86_64_plt32-as-r_x86_64_pc32.patch
This is a note to let you know that I've just added the patch titled
x86/module: Detect and skip invalid relocations
to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum…
The filename of the patch is:
x86-module-detect-and-skip-invalid-relocations.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable(a)vger.kernel.org> know about it.
>From eda9cec4c9a12208a6f69fbe68f72a6311d50032 Mon Sep 17 00:00:00 2001
From: Josh Poimboeuf <jpoimboe(a)redhat.com>
Date: Fri, 3 Nov 2017 07:58:54 -0500
Subject: x86/module: Detect and skip invalid relocations
From: Josh Poimboeuf <jpoimboe(a)redhat.com>
commit eda9cec4c9a12208a6f69fbe68f72a6311d50032 upstream.
There have been some cases where external tooling (e.g., kpatch-build)
creates a corrupt relocation which targets the wrong address. This is a
silent failure which can corrupt memory in unexpected places.
On x86, the bytes of data being overwritten by relocations are always
initialized to zero beforehand. Use that knowledge to add sanity checks
to detect such cases before they corrupt memory.
Signed-off-by: Josh Poimboeuf <jpoimboe(a)redhat.com>
Cc: Linus Torvalds <torvalds(a)linux-foundation.org>
Cc: Peter Zijlstra <peterz(a)infradead.org>
Cc: Thomas Gleixner <tglx(a)linutronix.de>
Cc: jeyu(a)kernel.org
Cc: live-patching(a)vger.kernel.org
Link: http://lkml.kernel.org/r/37450d6c6225e54db107fba447ce9e56e5f758e9.150971355…
[ Restructured the messages, as it's unclear whether the relocation or the target is corrupted. ]
Signed-off-by: Ingo Molnar <mingo(a)kernel.org>
Cc: Matthias Kaehlcke <mka(a)chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
---
arch/x86/kernel/module.c | 13 +++++++++++++
1 file changed, 13 insertions(+)
--- a/arch/x86/kernel/module.c
+++ b/arch/x86/kernel/module.c
@@ -170,19 +170,27 @@ int apply_relocate_add(Elf64_Shdr *sechd
case R_X86_64_NONE:
break;
case R_X86_64_64:
+ if (*(u64 *)loc != 0)
+ goto invalid_relocation;
*(u64 *)loc = val;
break;
case R_X86_64_32:
+ if (*(u32 *)loc != 0)
+ goto invalid_relocation;
*(u32 *)loc = val;
if (val != *(u32 *)loc)
goto overflow;
break;
case R_X86_64_32S:
+ if (*(s32 *)loc != 0)
+ goto invalid_relocation;
*(s32 *)loc = val;
if ((s64)val != *(s32 *)loc)
goto overflow;
break;
case R_X86_64_PC32:
+ if (*(u32 *)loc != 0)
+ goto invalid_relocation;
val -= (u64)loc;
*(u32 *)loc = val;
#if 0
@@ -198,6 +206,11 @@ int apply_relocate_add(Elf64_Shdr *sechd
}
return 0;
+invalid_relocation:
+ pr_err("x86/modules: Skipping invalid relocation target, existing value is nonzero for type %d, loc %p, val %Lx\n",
+ (int)ELF64_R_TYPE(rel[i].r_info), loc, val);
+ return -ENOEXEC;
+
overflow:
pr_err("overflow in relocation type %d val %Lx\n",
(int)ELF64_R_TYPE(rel[i].r_info), val);
Patches currently in stable-queue which might be from jpoimboe(a)redhat.com are
queue-4.4/x86-module-detect-and-skip-invalid-relocations.patch
queue-4.4/nospec-include-asm-barrier.h-dependency.patch
This is a note to let you know that I've just added the patch titled
x86: Treat R_X86_64_PLT32 as R_X86_64_PC32
to the 4.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum…
The filename of the patch is:
x86-treat-r_x86_64_plt32-as-r_x86_64_pc32.patch
and it can be found in the queue-4.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable(a)vger.kernel.org> know about it.
>From b21ebf2fb4cde1618915a97cc773e287ff49173e Mon Sep 17 00:00:00 2001
From: "H.J. Lu" <hjl.tools(a)gmail.com>
Date: Wed, 7 Feb 2018 14:20:09 -0800
Subject: x86: Treat R_X86_64_PLT32 as R_X86_64_PC32
From: H.J. Lu <hjl.tools(a)gmail.com>
commit b21ebf2fb4cde1618915a97cc773e287ff49173e upstream.
On i386, there are 2 types of PLTs, PIC and non-PIC. PIE and shared
objects must use PIC PLT. To use PIC PLT, you need to load
_GLOBAL_OFFSET_TABLE_ into EBX first. There is no need for that on
x86-64 since x86-64 uses PC-relative PLT.
On x86-64, for 32-bit PC-relative branches, we can generate PLT32
relocation, instead of PC32 relocation, which can also be used as
a marker for 32-bit PC-relative branches. Linker can always reduce
PLT32 relocation to PC32 if function is defined locally. Local
functions should use PC32 relocation. As far as Linux kernel is
concerned, R_X86_64_PLT32 can be treated the same as R_X86_64_PC32
since Linux kernel doesn't use PLT.
R_X86_64_PLT32 for 32-bit PC-relative branches has been enabled in
binutils master branch which will become binutils 2.31.
[ hjl is working on having better documentation on this all, but a few
more notes from him:
"PLT32 relocation is used as marker for PC-relative branches. Because
of EBX, it looks odd to generate PLT32 relocation on i386 when EBX
doesn't have GOT.
As for symbol resolution, PLT32 and PC32 relocations are almost
interchangeable. But when linker sees PLT32 relocation against a
protected symbol, it can resolved locally at link-time since it is
used on a branch instruction. Linker can't do that for PC32
relocation"
but for the kernel use, the two are basically the same, and this
commit gets things building and working with the current binutils
master - Linus ]
Signed-off-by: H.J. Lu <hjl.tools(a)gmail.com>
Signed-off-by: Linus Torvalds <torvalds(a)linux-foundation.org>
Cc: Matthias Kaehlcke <mka(a)chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
---
arch/x86/kernel/machine_kexec_64.c | 1 +
arch/x86/kernel/module.c | 1 +
arch/x86/tools/relocs.c | 3 +++
3 files changed, 5 insertions(+)
--- a/arch/x86/kernel/machine_kexec_64.c
+++ b/arch/x86/kernel/machine_kexec_64.c
@@ -542,6 +542,7 @@ int arch_kexec_apply_relocations_add(con
goto overflow;
break;
case R_X86_64_PC32:
+ case R_X86_64_PLT32:
value -= (u64)address;
*(u32 *)location = value;
break;
--- a/arch/x86/kernel/module.c
+++ b/arch/x86/kernel/module.c
@@ -191,6 +191,7 @@ int apply_relocate_add(Elf64_Shdr *sechd
goto overflow;
break;
case R_X86_64_PC32:
+ case R_X86_64_PLT32:
if (*(u32 *)loc != 0)
goto invalid_relocation;
val -= (u64)loc;
--- a/arch/x86/tools/relocs.c
+++ b/arch/x86/tools/relocs.c
@@ -770,9 +770,12 @@ static int do_reloc64(struct section *se
break;
case R_X86_64_PC32:
+ case R_X86_64_PLT32:
/*
* PC relative relocations don't need to be adjusted unless
* referencing a percpu symbol.
+ *
+ * NB: R_X86_64_PLT32 can be treated as R_X86_64_PC32.
*/
if (is_percpu_sym(sym, symname))
add_reloc(&relocs32neg, offset);
Patches currently in stable-queue which might be from hjl.tools(a)gmail.com are
queue-4.15/x86-treat-r_x86_64_plt32-as-r_x86_64_pc32.patch
This is a note to let you know that I've just added the patch titled
x86: Treat R_X86_64_PLT32 as R_X86_64_PC32
to the 4.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum…
The filename of the patch is:
x86-treat-r_x86_64_plt32-as-r_x86_64_pc32.patch
and it can be found in the queue-4.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable(a)vger.kernel.org> know about it.
>From b21ebf2fb4cde1618915a97cc773e287ff49173e Mon Sep 17 00:00:00 2001
From: "H.J. Lu" <hjl.tools(a)gmail.com>
Date: Wed, 7 Feb 2018 14:20:09 -0800
Subject: x86: Treat R_X86_64_PLT32 as R_X86_64_PC32
From: H.J. Lu <hjl.tools(a)gmail.com>
commit b21ebf2fb4cde1618915a97cc773e287ff49173e upstream.
On i386, there are 2 types of PLTs, PIC and non-PIC. PIE and shared
objects must use PIC PLT. To use PIC PLT, you need to load
_GLOBAL_OFFSET_TABLE_ into EBX first. There is no need for that on
x86-64 since x86-64 uses PC-relative PLT.
On x86-64, for 32-bit PC-relative branches, we can generate PLT32
relocation, instead of PC32 relocation, which can also be used as
a marker for 32-bit PC-relative branches. Linker can always reduce
PLT32 relocation to PC32 if function is defined locally. Local
functions should use PC32 relocation. As far as Linux kernel is
concerned, R_X86_64_PLT32 can be treated the same as R_X86_64_PC32
since Linux kernel doesn't use PLT.
R_X86_64_PLT32 for 32-bit PC-relative branches has been enabled in
binutils master branch which will become binutils 2.31.
[ hjl is working on having better documentation on this all, but a few
more notes from him:
"PLT32 relocation is used as marker for PC-relative branches. Because
of EBX, it looks odd to generate PLT32 relocation on i386 when EBX
doesn't have GOT.
As for symbol resolution, PLT32 and PC32 relocations are almost
interchangeable. But when linker sees PLT32 relocation against a
protected symbol, it can resolved locally at link-time since it is
used on a branch instruction. Linker can't do that for PC32
relocation"
but for the kernel use, the two are basically the same, and this
commit gets things building and working with the current binutils
master - Linus ]
Signed-off-by: H.J. Lu <hjl.tools(a)gmail.com>
Signed-off-by: Linus Torvalds <torvalds(a)linux-foundation.org>
Cc: Matthias Kaehlcke <mka(a)chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
---
arch/x86/kernel/machine_kexec_64.c | 1 +
arch/x86/kernel/module.c | 1 +
arch/x86/tools/relocs.c | 3 +++
3 files changed, 5 insertions(+)
--- a/arch/x86/kernel/machine_kexec_64.c
+++ b/arch/x86/kernel/machine_kexec_64.c
@@ -542,6 +542,7 @@ int arch_kexec_apply_relocations_add(con
goto overflow;
break;
case R_X86_64_PC32:
+ case R_X86_64_PLT32:
value -= (u64)address;
*(u32 *)location = value;
break;
--- a/arch/x86/kernel/module.c
+++ b/arch/x86/kernel/module.c
@@ -191,6 +191,7 @@ int apply_relocate_add(Elf64_Shdr *sechd
goto overflow;
break;
case R_X86_64_PC32:
+ case R_X86_64_PLT32:
if (*(u32 *)loc != 0)
goto invalid_relocation;
val -= (u64)loc;
--- a/arch/x86/tools/relocs.c
+++ b/arch/x86/tools/relocs.c
@@ -770,9 +770,12 @@ static int do_reloc64(struct section *se
break;
case R_X86_64_PC32:
+ case R_X86_64_PLT32:
/*
* PC relative relocations don't need to be adjusted unless
* referencing a percpu symbol.
+ *
+ * NB: R_X86_64_PLT32 can be treated as R_X86_64_PC32.
*/
if (is_percpu_sym(sym, symname))
add_reloc(&relocs32neg, offset);
Patches currently in stable-queue which might be from hjl.tools(a)gmail.com are
queue-4.14/x86-treat-r_x86_64_plt32-as-r_x86_64_pc32.patch
This is a note to let you know that I've just added the patch titled
x86: Treat R_X86_64_PLT32 as R_X86_64_PC32
to the 3.18-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum…
The filename of the patch is:
x86-treat-r_x86_64_plt32-as-r_x86_64_pc32.patch
and it can be found in the queue-3.18 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable(a)vger.kernel.org> know about it.
>From b21ebf2fb4cde1618915a97cc773e287ff49173e Mon Sep 17 00:00:00 2001
From: "H.J. Lu" <hjl.tools(a)gmail.com>
Date: Wed, 7 Feb 2018 14:20:09 -0800
Subject: x86: Treat R_X86_64_PLT32 as R_X86_64_PC32
From: H.J. Lu <hjl.tools(a)gmail.com>
commit b21ebf2fb4cde1618915a97cc773e287ff49173e upstream.
On i386, there are 2 types of PLTs, PIC and non-PIC. PIE and shared
objects must use PIC PLT. To use PIC PLT, you need to load
_GLOBAL_OFFSET_TABLE_ into EBX first. There is no need for that on
x86-64 since x86-64 uses PC-relative PLT.
On x86-64, for 32-bit PC-relative branches, we can generate PLT32
relocation, instead of PC32 relocation, which can also be used as
a marker for 32-bit PC-relative branches. Linker can always reduce
PLT32 relocation to PC32 if function is defined locally. Local
functions should use PC32 relocation. As far as Linux kernel is
concerned, R_X86_64_PLT32 can be treated the same as R_X86_64_PC32
since Linux kernel doesn't use PLT.
R_X86_64_PLT32 for 32-bit PC-relative branches has been enabled in
binutils master branch which will become binutils 2.31.
[ hjl is working on having better documentation on this all, but a few
more notes from him:
"PLT32 relocation is used as marker for PC-relative branches. Because
of EBX, it looks odd to generate PLT32 relocation on i386 when EBX
doesn't have GOT.
As for symbol resolution, PLT32 and PC32 relocations are almost
interchangeable. But when linker sees PLT32 relocation against a
protected symbol, it can resolved locally at link-time since it is
used on a branch instruction. Linker can't do that for PC32
relocation"
but for the kernel use, the two are basically the same, and this
commit gets things building and working with the current binutils
master - Linus ]
Signed-off-by: H.J. Lu <hjl.tools(a)gmail.com>
Signed-off-by: Linus Torvalds <torvalds(a)linux-foundation.org>
Cc: Matthias Kaehlcke <mka(a)chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
---
arch/x86/kernel/machine_kexec_64.c | 1 +
arch/x86/kernel/module.c | 1 +
arch/x86/tools/relocs.c | 3 +++
3 files changed, 5 insertions(+)
--- a/arch/x86/kernel/machine_kexec_64.c
+++ b/arch/x86/kernel/machine_kexec_64.c
@@ -516,6 +516,7 @@ int arch_kexec_apply_relocations_add(con
goto overflow;
break;
case R_X86_64_PC32:
+ case R_X86_64_PLT32:
value -= (u64)address;
*(u32 *)location = value;
break;
--- a/arch/x86/kernel/module.c
+++ b/arch/x86/kernel/module.c
@@ -186,6 +186,7 @@ int apply_relocate_add(Elf64_Shdr *sechd
goto overflow;
break;
case R_X86_64_PC32:
+ case R_X86_64_PLT32:
if (*(u32 *)loc != 0)
goto invalid_relocation;
val -= (u64)loc;
--- a/arch/x86/tools/relocs.c
+++ b/arch/x86/tools/relocs.c
@@ -769,9 +769,12 @@ static int do_reloc64(struct section *se
break;
case R_X86_64_PC32:
+ case R_X86_64_PLT32:
/*
* PC relative relocations don't need to be adjusted unless
* referencing a percpu symbol.
+ *
+ * NB: R_X86_64_PLT32 can be treated as R_X86_64_PC32.
*/
if (is_percpu_sym(sym, symname))
add_reloc(&relocs32neg, offset);
Patches currently in stable-queue which might be from hjl.tools(a)gmail.com are
queue-3.18/x86-treat-r_x86_64_plt32-as-r_x86_64_pc32.patch
This is a note to let you know that I've just added the patch titled
x86/module: Detect and skip invalid relocations
to the 3.18-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum…
The filename of the patch is:
x86-module-detect-and-skip-invalid-relocations.patch
and it can be found in the queue-3.18 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable(a)vger.kernel.org> know about it.
>From eda9cec4c9a12208a6f69fbe68f72a6311d50032 Mon Sep 17 00:00:00 2001
From: Josh Poimboeuf <jpoimboe(a)redhat.com>
Date: Fri, 3 Nov 2017 07:58:54 -0500
Subject: x86/module: Detect and skip invalid relocations
From: Josh Poimboeuf <jpoimboe(a)redhat.com>
commit eda9cec4c9a12208a6f69fbe68f72a6311d50032 upstream.
There have been some cases where external tooling (e.g., kpatch-build)
creates a corrupt relocation which targets the wrong address. This is a
silent failure which can corrupt memory in unexpected places.
On x86, the bytes of data being overwritten by relocations are always
initialized to zero beforehand. Use that knowledge to add sanity checks
to detect such cases before they corrupt memory.
Signed-off-by: Josh Poimboeuf <jpoimboe(a)redhat.com>
Cc: Linus Torvalds <torvalds(a)linux-foundation.org>
Cc: Peter Zijlstra <peterz(a)infradead.org>
Cc: Thomas Gleixner <tglx(a)linutronix.de>
Cc: jeyu(a)kernel.org
Cc: live-patching(a)vger.kernel.org
Link: http://lkml.kernel.org/r/37450d6c6225e54db107fba447ce9e56e5f758e9.150971355…
[ Restructured the messages, as it's unclear whether the relocation or the target is corrupted. ]
Signed-off-by: Ingo Molnar <mingo(a)kernel.org>
Cc: Matthias Kaehlcke <mka(a)chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
---
arch/x86/kernel/module.c | 13 +++++++++++++
1 file changed, 13 insertions(+)
--- a/arch/x86/kernel/module.c
+++ b/arch/x86/kernel/module.c
@@ -167,19 +167,27 @@ int apply_relocate_add(Elf64_Shdr *sechd
case R_X86_64_NONE:
break;
case R_X86_64_64:
+ if (*(u64 *)loc != 0)
+ goto invalid_relocation;
*(u64 *)loc = val;
break;
case R_X86_64_32:
+ if (*(u32 *)loc != 0)
+ goto invalid_relocation;
*(u32 *)loc = val;
if (val != *(u32 *)loc)
goto overflow;
break;
case R_X86_64_32S:
+ if (*(s32 *)loc != 0)
+ goto invalid_relocation;
*(s32 *)loc = val;
if ((s64)val != *(s32 *)loc)
goto overflow;
break;
case R_X86_64_PC32:
+ if (*(u32 *)loc != 0)
+ goto invalid_relocation;
val -= (u64)loc;
*(u32 *)loc = val;
#if 0
@@ -195,6 +203,11 @@ int apply_relocate_add(Elf64_Shdr *sechd
}
return 0;
+invalid_relocation:
+ pr_err("x86/modules: Skipping invalid relocation target, existing value is nonzero for type %d, loc %p, val %Lx\n",
+ (int)ELF64_R_TYPE(rel[i].r_info), loc, val);
+ return -ENOEXEC;
+
overflow:
pr_err("overflow in relocation type %d val %Lx\n",
(int)ELF64_R_TYPE(rel[i].r_info), val);
Patches currently in stable-queue which might be from jpoimboe(a)redhat.com are
queue-3.18/x86-module-detect-and-skip-invalid-relocations.patch
Hi Greg,
The below patch recently landed in Linus' tree:
commit b21ebf2fb4cde1618915a97cc773e287ff49173e
Author: H.J. Lu <hjl.tools(a)gmail.com>
Date: Wed Feb 7 14:20:09 2018 -0800
x86: Treat R_X86_64_PLT32 as R_X86_64_PC32
On i386, there are 2 types of PLTs, PIC and non-PIC. PIE and shared
objects must use PIC PLT. To use PIC PLT, you need to load
_GLOBAL_OFFSET_TABLE_ into EBX first. There is no need for that on
x86-64 since x86-64 uses PC-relative PLT.
On x86-64, for 32-bit PC-relative branches, we can generate PLT32
relocation, instead of PC32 relocation, which can also be used as
a marker for 32-bit PC-relative branches. Linker can always reduce
PLT32 relocation to PC32 if function is defined locally. Local
functions should use PC32 relocation. As far as Linux kernel is
concerned, R_X86_64_PLT32 can be treated the same as R_X86_64_PC32
since Linux kernel doesn't use PLT.
R_X86_64_PLT32 for 32-bit PC-relative branches has been enabled in
binutils master branch which will become binutils 2.31.
[ hjl is working on having better documentation on this all, but a few
more notes from him:
"PLT32 relocation is used as marker for PC-relative branches. Because
of EBX, it looks odd to generate PLT32 relocation on i386 when EBX
doesn't have GOT.
As for symbol resolution, PLT32 and PC32 relocations are almost
interchangeable. But when linker sees PLT32 relocation against a
protected symbol, it can resolved locally at link-time since it is
used on a branch instruction. Linker can't do that for PC32
relocation"
but for the kernel use, the two are basically the same, and this
commit gets things building and working with the current binutils
master - Linus ]
Signed-off-by: H.J. Lu <hjl.tools(a)gmail.com>
Signed-off-by: Linus Torvalds <torvalds(a)linux-foundation.org>
The commit message mentions that "R_X86_64_PLT32 for 32-bit
PC-relative branches has been enabled in binutils master branch which
will become binutils 2.31."
This probably means that builds of older kernels could fail with
binutils >= 2.31 and that the patch should be included in stable.
FYI: for pre-v4.14 kernel you might also want to include the below
patch. It isn't strictly needed, but is trivial and including it
avoids a conflict.
commit eda9cec4c9a12208a6f69fbe68f72a6311d50032
Author: Josh Poimboeuf <jpoimboe(a)redhat.com>
Date: Fri Nov 3 07:58:54 2017 -0500
x86/module: Detect and skip invalid relocations
Thanks
Matthias