- Linux-stable-mirror - lists.linaro.org

[Linux-stable-mirror] Patch "x86/retpoline: Add LFENCE to the retpoline/RSB filling RSB macros" has been added to the 4.9-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled x86/retpoline: Add LFENCE to the retpoline/RSB filling RSB macros 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-retpoline-add-lfence-to-the-retpoline-rsb-filling-rsb-macros.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 28d437d550e1e39f805d99f9f8ac399c778827b7 Mon Sep 17 00:00:00 2001 From: Tom Lendacky <thomas.lendacky(a)amd.com> Date: Sat, 13 Jan 2018 17:27:30 -0600 Subject: x86/retpoline: Add LFENCE to the retpoline/RSB filling RSB macros From: Tom Lendacky <thomas.lendacky(a)amd.com> commit 28d437d550e1e39f805d99f9f8ac399c778827b7 upstream. The PAUSE instruction is currently used in the retpoline and RSB filling macros as a speculation trap. The use of PAUSE was originally suggested because it showed a very, very small difference in the amount of cycles/time used to execute the retpoline as compared to LFENCE. On AMD, the PAUSE instruction is not a serializing instruction, so the pause/jmp loop will use excess power as it is speculated over waiting for return to mispredict to the correct target. The RSB filling macro is applicable to AMD, and, if software is unable to verify that LFENCE is serializing on AMD (possible when running under a hypervisor), the generic retpoline support will be used and, so, is also applicable to AMD. Keep the current usage of PAUSE for Intel, but add an LFENCE instruction to the speculation trap for AMD. The same sequence has been adopted by GCC for the GCC generated retpolines. Signed-off-by: Tom Lendacky <thomas.lendacky(a)amd.com> Signed-off-by: Thomas Gleixner <tglx(a)linutronix.de> Reviewed-by: Borislav Petkov <bp(a)alien8.de> Acked-by: David Woodhouse <dwmw(a)amazon.co.uk> Acked-by: Arjan van de Ven <arjan(a)linux.intel.com> Cc: Rik van Riel <riel(a)redhat.com> Cc: Andi Kleen <ak(a)linux.intel.com> Cc: Paul Turner <pjt(a)google.com> Cc: Peter Zijlstra <peterz(a)infradead.org> Cc: Tim Chen <tim.c.chen(a)linux.intel.com> Cc: Jiri Kosina <jikos(a)kernel.org> Cc: Dave Hansen <dave.hansen(a)intel.com> Cc: Andy Lutomirski <luto(a)kernel.org> Cc: Josh Poimboeuf <jpoimboe(a)redhat.com> Cc: Dan Williams <dan.j.williams(a)intel.com> Cc: Linus Torvalds <torvalds(a)linux-foundation.org> Cc: Greg Kroah-Hartman <gregkh(a)linux-foundation.org> Cc: Kees Cook <keescook(a)google.com> Link: https://lkml.kernel.org/r/20180113232730.31060.36287.stgit@tlendack-t1.amdo… Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- arch/x86/include/asm/nospec-branch.h | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) --- a/arch/x86/include/asm/nospec-branch.h +++ b/arch/x86/include/asm/nospec-branch.h @@ -11,7 +11,7 @@ * Fill the CPU return stack buffer. * * Each entry in the RSB, if used for a speculative 'ret', contains an - * infinite 'pause; jmp' loop to capture speculative execution. + * infinite 'pause; lfence; jmp' loop to capture speculative execution. * * This is required in various cases for retpoline and IBRS-based * mitigations for the Spectre variant 2 vulnerability. Sometimes to @@ -38,11 +38,13 @@ call 772f; \ 773: /* speculation trap */ \ pause; \ + lfence; \ jmp 773b; \ 772: \ call 774f; \ 775: /* speculation trap */ \ pause; \ + lfence; \ jmp 775b; \ 774: \ dec reg; \ @@ -73,6 +75,7 @@ call .Ldo_rop_\@ .Lspec_trap_\@: pause + lfence jmp .Lspec_trap_\@ .Ldo_rop_\@: mov \reg, (%_ASM_SP) @@ -165,6 +168,7 @@ " .align 16\n" \ "901: call 903f;\n" \ "902: pause;\n" \ + " lfence;\n" \ " jmp 902b;\n" \ " .align 16\n" \ "903: addl $4, %%esp;\n" \ Patches currently in stable-queue which might be from thomas.lendacky(a)amd.com are queue-4.9/x86-retpoline-fill-rsb-on-context-switch-for-affected-cpus.patch queue-4.9/x86-retpoline-add-lfence-to-the-retpoline-rsb-filling-rsb-macros.patch

7 years, 1 month

1
0
0 0

[Linux-stable-mirror] Patch "x86/cpufeature: Move processor tracing out of scattered features" has been added to the 4.9-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled x86/cpufeature: Move processor tracing out of scattered features 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-cpufeature-move-processor-tracing-out-of-scattered-features.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 4fdec2034b7540dda461c6ba33325dfcff345c64 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini <pbonzini(a)redhat.com> Date: Tue, 16 Jan 2018 16:42:25 +0100 Subject: x86/cpufeature: Move processor tracing out of scattered features MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Paolo Bonzini <pbonzini(a)redhat.com> commit 4fdec2034b7540dda461c6ba33325dfcff345c64 upstream. Processor tracing is already enumerated in word 9 (CPUID[7,0].EBX), so do not duplicate it in the scattered features word. Besides being more tidy, this will be useful for KVM when it presents processor tracing to the guests. KVM selects host features that are supported by both the host kernel (depending on command line options, CPU errata, or whatever) and KVM. Whenever a full feature word exists, KVM's code is written in the expectation that the CPUID bit number matches the X86_FEATURE_* bit number, but this is not the case for X86_FEATURE_INTEL_PT. Signed-off-by: Paolo Bonzini <pbonzini(a)redhat.com> Cc: Borislav Petkov <bp(a)suse.de> Cc: Linus Torvalds <torvalds(a)linux-foundation.org> Cc: Luwei Kang <luwei.kang(a)intel.com> Cc: Peter Zijlstra <peterz(a)infradead.org> Cc: Radim Krčmář <rkrcmar(a)redhat.com> Cc: Thomas Gleixner <tglx(a)linutronix.de> Cc: kvm(a)vger.kernel.org Link: http://lkml.kernel.org/r/1516117345-34561-1-git-send-email-pbonzini@redhat.… Signed-off-by: Ingo Molnar <mingo(a)kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- arch/x86/include/asm/cpufeatures.h | 2 +- arch/x86/kernel/cpu/scattered.c | 1 - 2 files changed, 1 insertion(+), 2 deletions(-) --- a/arch/x86/include/asm/cpufeatures.h +++ b/arch/x86/include/asm/cpufeatures.h @@ -197,7 +197,6 @@ #define X86_FEATURE_RETPOLINE ( 7*32+12) /* Generic Retpoline mitigation for Spectre variant 2 */ #define X86_FEATURE_RETPOLINE_AMD ( 7*32+13) /* AMD Retpoline mitigation for Spectre variant 2 */ -#define X86_FEATURE_INTEL_PT ( 7*32+15) /* Intel Processor Trace */ #define X86_FEATURE_AVX512_4VNNIW (7*32+16) /* AVX-512 Neural Network Instructions */ #define X86_FEATURE_AVX512_4FMAPS (7*32+17) /* AVX-512 Multiply Accumulation Single precision */ #define X86_FEATURE_RSB_CTXSW ( 7*32+19) /* Fill RSB on context switches */ @@ -236,6 +235,7 @@ #define X86_FEATURE_SMAP ( 9*32+20) /* Supervisor Mode Access Prevention */ #define X86_FEATURE_CLFLUSHOPT ( 9*32+23) /* CLFLUSHOPT instruction */ #define X86_FEATURE_CLWB ( 9*32+24) /* CLWB instruction */ +#define X86_FEATURE_INTEL_PT ( 9*32+25) /* Intel Processor Trace */ #define X86_FEATURE_AVX512PF ( 9*32+26) /* AVX-512 Prefetch */ #define X86_FEATURE_AVX512ER ( 9*32+27) /* AVX-512 Exponential and Reciprocal */ #define X86_FEATURE_AVX512CD ( 9*32+28) /* AVX-512 Conflict Detection */ --- a/arch/x86/kernel/cpu/scattered.c +++ b/arch/x86/kernel/cpu/scattered.c @@ -31,7 +31,6 @@ void init_scattered_cpuid_features(struc const struct cpuid_bit *cb; static const struct cpuid_bit cpuid_bits[] = { - { X86_FEATURE_INTEL_PT, CR_EBX,25, 0x00000007, 0 }, { X86_FEATURE_AVX512_4VNNIW, CR_EDX, 2, 0x00000007, 0 }, { X86_FEATURE_AVX512_4FMAPS, CR_EDX, 3, 0x00000007, 0 }, { X86_FEATURE_APERFMPERF, CR_ECX, 0, 0x00000006, 0 }, Patches currently in stable-queue which might be from pbonzini(a)redhat.com are queue-4.9/x86-cpufeature-move-processor-tracing-out-of-scattered-features.patch

7 years, 1 month

1
0
0 0

[Linux-stable-mirror] Patch "x86/mm/pkeys: Fix fill_sig_info_pkey" has been added to the 4.9-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled x86/mm/pkeys: Fix fill_sig_info_pkey 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-mm-pkeys-fix-fill_sig_info_pkey.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 beacd6f7ed5e2915959442245b3b2480c2e37490 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" <ebiederm(a)xmission.com> Date: Fri, 12 Jan 2018 14:31:35 -0600 Subject: x86/mm/pkeys: Fix fill_sig_info_pkey From: Eric W. Biederman <ebiederm(a)xmission.com> commit beacd6f7ed5e2915959442245b3b2480c2e37490 upstream. SEGV_PKUERR is a signal specific si_code which happens to have the same numeric value as several others: BUS_MCEERR_AR, ILL_ILLTRP, FPE_FLTOVF, TRAP_HWBKPT, CLD_TRAPPED, POLL_ERR, SEGV_THREAD_ID, as such it is not safe to just test the si_code the signal number must also be tested to prevent a false positive in fill_sig_info_pkey. This error was by inspection, and BUS_MCEERR_AR appears to be a real candidate for confusion. So pass in si_signo and check for SIG_SEGV to verify that it is actually a SEGV_PKUERR Fixes: 019132ff3daf ("x86/mm/pkeys: Fill in pkey field in siginfo") Signed-off-by: "Eric W. Biederman" <ebiederm(a)xmission.com> Signed-off-by: Thomas Gleixner <tglx(a)linutronix.de> Cc: linux-arch(a)vger.kernel.org Cc: Dave Hansen <dave.hansen(a)linux.intel.com> Cc: Oleg Nesterov <oleg(a)redhat.com> Cc: Al Viro <viro(a)zeniv.linux.org.uk> Link: https://lkml.kernel.org/r/20180112203135.4669-2-ebiederm@xmission.com Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- arch/x86/mm/fault.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -191,14 +191,15 @@ is_prefetch(struct pt_regs *regs, unsign * 6. T1 : reaches here, sees vma_pkey(vma)=5, when we really * faulted on a pte with its pkey=4. */ -static void fill_sig_info_pkey(int si_code, siginfo_t *info, u32 *pkey) +static void fill_sig_info_pkey(int si_signo, int si_code, siginfo_t *info, + u32 *pkey) { /* This is effectively an #ifdef */ if (!boot_cpu_has(X86_FEATURE_OSPKE)) return; /* Fault not from Protection Keys: nothing to do */ - if (si_code != SEGV_PKUERR) + if ((si_code != SEGV_PKUERR) || (si_signo != SIGSEGV)) return; /* * force_sig_info_fault() is called from a number of @@ -237,7 +238,7 @@ force_sig_info_fault(int si_signo, int s lsb = PAGE_SHIFT; info.si_addr_lsb = lsb; - fill_sig_info_pkey(si_code, &info, pkey); + fill_sig_info_pkey(si_signo, si_code, &info, pkey); force_sig_info(si_signo, &info, tsk); } Patches currently in stable-queue which might be from ebiederm(a)xmission.com are queue-4.9/x86-mm-pkeys-fix-fill_sig_info_pkey.patch

7 years, 1 month

1
0
0 0

[Linux-stable-mirror] Patch "objtool: Improve error message for bad file argument" has been added to the 4.9-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled objtool: Improve error message for bad file argument 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: objtool-improve-error-message-for-bad-file-argument.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 385d11b152c4eb638eeb769edcb3249533bb9a00 Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf <jpoimboe(a)redhat.com> Date: Mon, 15 Jan 2018 08:17:08 -0600 Subject: objtool: Improve error message for bad file argument From: Josh Poimboeuf <jpoimboe(a)redhat.com> commit 385d11b152c4eb638eeb769edcb3249533bb9a00 upstream. If a nonexistent file is supplied to objtool, it complains with a non-helpful error: open: No such file or directory Improve it to: objtool: Can't open 'foo': No such file or directory Reported-by: Markus <M4rkusXXL(a)web.de> 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> Link: http://lkml.kernel.org/r/406a3d00a21225eee2819844048e17f68523ccf6.151602565… Signed-off-by: Ingo Molnar <mingo(a)kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- tools/objtool/elf.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/tools/objtool/elf.c +++ b/tools/objtool/elf.c @@ -26,6 +26,7 @@ #include <stdlib.h> #include <string.h> #include <unistd.h> +#include <errno.h> #include "elf.h" #include "warn.h" @@ -370,7 +371,8 @@ struct elf *elf_open(const char *name) elf->fd = open(name, O_RDONLY); if (elf->fd == -1) { - perror("open"); + fprintf(stderr, "objtool: Can't open '%s': %s\n", + name, strerror(errno)); goto err; } Patches currently in stable-queue which might be from jpoimboe(a)redhat.com are queue-4.9/objtool-improve-error-message-for-bad-file-argument.patch queue-4.9/x86-retpoline-fill-rsb-on-context-switch-for-affected-cpus.patch queue-4.9/x86-retpoline-add-lfence-to-the-retpoline-rsb-filling-rsb-macros.patch

7 years, 1 month

1
0
0 0

[Linux-stable-mirror] Patch "module: Add retpoline tag to VERMAGIC" has been added to the 4.9-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled module: Add retpoline tag to VERMAGIC 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: module-add-retpoline-tag-to-vermagic.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 6cfb521ac0d5b97470883ff9b7facae264b7ab12 Mon Sep 17 00:00:00 2001 From: Andi Kleen <ak(a)linux.intel.com> Date: Tue, 16 Jan 2018 12:52:28 -0800 Subject: module: Add retpoline tag to VERMAGIC From: Andi Kleen <ak(a)linux.intel.com> commit 6cfb521ac0d5b97470883ff9b7facae264b7ab12 upstream. Add a marker for retpoline to the module VERMAGIC. This catches the case when a non RETPOLINE compiled module gets loaded into a retpoline kernel, making it insecure. It doesn't handle the case when retpoline has been runtime disabled. Even in this case the match of the retcompile status will be enforced. This implies that even with retpoline run time disabled all modules loaded need to be recompiled. Signed-off-by: Andi Kleen <ak(a)linux.intel.com> Signed-off-by: Thomas Gleixner <tglx(a)linutronix.de> Reviewed-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> Acked-by: David Woodhouse <dwmw(a)amazon.co.uk> Cc: rusty(a)rustcorp.com.au Cc: arjan.van.de.ven(a)intel.com Cc: jeyu(a)kernel.org Cc: torvalds(a)linux-foundation.org Link: https://lkml.kernel.org/r/20180116205228.4890-1-andi@firstfloor.org Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- include/linux/vermagic.h | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) --- a/include/linux/vermagic.h +++ b/include/linux/vermagic.h @@ -24,10 +24,16 @@ #ifndef MODULE_ARCH_VERMAGIC #define MODULE_ARCH_VERMAGIC "" #endif +#ifdef RETPOLINE +#define MODULE_VERMAGIC_RETPOLINE "retpoline " +#else +#define MODULE_VERMAGIC_RETPOLINE "" +#endif #define VERMAGIC_STRING \ UTS_RELEASE " " \ MODULE_VERMAGIC_SMP MODULE_VERMAGIC_PREEMPT \ MODULE_VERMAGIC_MODULE_UNLOAD MODULE_VERMAGIC_MODVERSIONS \ - MODULE_ARCH_VERMAGIC + MODULE_ARCH_VERMAGIC \ + MODULE_VERMAGIC_RETPOLINE Patches currently in stable-queue which might be from ak(a)linux.intel.com are queue-4.9/module-add-retpoline-tag-to-vermagic.patch queue-4.9/x86-retpoline-fill-rsb-on-context-switch-for-affected-cpus.patch queue-4.9/x86-retpoline-add-lfence-to-the-retpoline-rsb-filling-rsb-macros.patch

7 years, 1 month

1
0
0 0

[Linux-stable-mirror] Patch "x86/retpoline: Add LFENCE to the retpoline/RSB filling RSB macros" has been added to the 4.4-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled x86/retpoline: Add LFENCE to the retpoline/RSB filling RSB macros 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-retpoline-add-lfence-to-the-retpoline-rsb-filling-rsb-macros.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 28d437d550e1e39f805d99f9f8ac399c778827b7 Mon Sep 17 00:00:00 2001 From: Tom Lendacky <thomas.lendacky(a)amd.com> Date: Sat, 13 Jan 2018 17:27:30 -0600 Subject: x86/retpoline: Add LFENCE to the retpoline/RSB filling RSB macros From: Tom Lendacky <thomas.lendacky(a)amd.com> commit 28d437d550e1e39f805d99f9f8ac399c778827b7 upstream. The PAUSE instruction is currently used in the retpoline and RSB filling macros as a speculation trap. The use of PAUSE was originally suggested because it showed a very, very small difference in the amount of cycles/time used to execute the retpoline as compared to LFENCE. On AMD, the PAUSE instruction is not a serializing instruction, so the pause/jmp loop will use excess power as it is speculated over waiting for return to mispredict to the correct target. The RSB filling macro is applicable to AMD, and, if software is unable to verify that LFENCE is serializing on AMD (possible when running under a hypervisor), the generic retpoline support will be used and, so, is also applicable to AMD. Keep the current usage of PAUSE for Intel, but add an LFENCE instruction to the speculation trap for AMD. The same sequence has been adopted by GCC for the GCC generated retpolines. Signed-off-by: Tom Lendacky <thomas.lendacky(a)amd.com> Signed-off-by: Thomas Gleixner <tglx(a)linutronix.de> Reviewed-by: Borislav Petkov <bp(a)alien8.de> Acked-by: David Woodhouse <dwmw(a)amazon.co.uk> Acked-by: Arjan van de Ven <arjan(a)linux.intel.com> Cc: Rik van Riel <riel(a)redhat.com> Cc: Andi Kleen <ak(a)linux.intel.com> Cc: Paul Turner <pjt(a)google.com> Cc: Peter Zijlstra <peterz(a)infradead.org> Cc: Tim Chen <tim.c.chen(a)linux.intel.com> Cc: Jiri Kosina <jikos(a)kernel.org> Cc: Dave Hansen <dave.hansen(a)intel.com> Cc: Andy Lutomirski <luto(a)kernel.org> Cc: Josh Poimboeuf <jpoimboe(a)redhat.com> Cc: Dan Williams <dan.j.williams(a)intel.com> Cc: Linus Torvalds <torvalds(a)linux-foundation.org> Cc: Greg Kroah-Hartman <gregkh(a)linux-foundation.org> Cc: Kees Cook <keescook(a)google.com> Link: https://lkml.kernel.org/r/20180113232730.31060.36287.stgit@tlendack-t1.amdo… Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- arch/x86/include/asm/nospec-branch.h | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) --- a/arch/x86/include/asm/nospec-branch.h +++ b/arch/x86/include/asm/nospec-branch.h @@ -11,7 +11,7 @@ * Fill the CPU return stack buffer. * * Each entry in the RSB, if used for a speculative 'ret', contains an - * infinite 'pause; jmp' loop to capture speculative execution. + * infinite 'pause; lfence; jmp' loop to capture speculative execution. * * This is required in various cases for retpoline and IBRS-based * mitigations for the Spectre variant 2 vulnerability. Sometimes to @@ -38,11 +38,13 @@ call 772f; \ 773: /* speculation trap */ \ pause; \ + lfence; \ jmp 773b; \ 772: \ call 774f; \ 775: /* speculation trap */ \ pause; \ + lfence; \ jmp 775b; \ 774: \ dec reg; \ @@ -60,6 +62,7 @@ call .Ldo_rop_\@ .Lspec_trap_\@: pause + lfence jmp .Lspec_trap_\@ .Ldo_rop_\@: mov \reg, (%_ASM_SP) @@ -142,6 +145,7 @@ " .align 16\n" \ "901: call 903f;\n" \ "902: pause;\n" \ + " lfence;\n" \ " jmp 902b;\n" \ " .align 16\n" \ "903: addl $4, %%esp;\n" \ Patches currently in stable-queue which might be from thomas.lendacky(a)amd.com are queue-4.4/x86-spectre-add-boot-time-option-to-select-spectre-v2-mitigation.patch queue-4.4/x86-retpoline-irq32-convert-assembler-indirect-jumps.patch queue-4.4/x86-retpoline-hyperv-convert-assembler-indirect-jumps.patch queue-4.4/x86-retpoline-entry-convert-entry-assembler-indirect-jumps.patch queue-4.4/x86-cpu-amd-make-lfence-a-serializing-instruction.patch queue-4.4/x86-retpoline-ftrace-convert-ftrace-assembler-indirect-jumps.patch queue-4.4/x86-retpoline-crypto-convert-crypto-assembler-indirect-jumps.patch queue-4.4/x86-retpoline-xen-convert-xen-hypercall-indirect-jumps.patch queue-4.4/x86-retpoline-checksum32-convert-assembler-indirect-jumps.patch queue-4.4/x86-retpoline-fill-return-stack-buffer-on-vmexit.patch queue-4.4/x86-retpoline-add-lfence-to-the-retpoline-rsb-filling-rsb-macros.patch queue-4.4/x86-retpoline-remove-compile-time-warning.patch queue-4.4/x86-cpu-amd-use-lfence_rdtsc-in-preference-to-mfence_rdtsc.patch queue-4.4/x86-retpoline-add-initial-retpoline-support.patch

7 years, 1 month

1
0
0 0

[Linux-stable-mirror] Patch "module: Add retpoline tag to VERMAGIC" has been added to the 4.4-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled module: Add retpoline tag to VERMAGIC 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: module-add-retpoline-tag-to-vermagic.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 6cfb521ac0d5b97470883ff9b7facae264b7ab12 Mon Sep 17 00:00:00 2001 From: Andi Kleen <ak(a)linux.intel.com> Date: Tue, 16 Jan 2018 12:52:28 -0800 Subject: module: Add retpoline tag to VERMAGIC From: Andi Kleen <ak(a)linux.intel.com> commit 6cfb521ac0d5b97470883ff9b7facae264b7ab12 upstream. Add a marker for retpoline to the module VERMAGIC. This catches the case when a non RETPOLINE compiled module gets loaded into a retpoline kernel, making it insecure. It doesn't handle the case when retpoline has been runtime disabled. Even in this case the match of the retcompile status will be enforced. This implies that even with retpoline run time disabled all modules loaded need to be recompiled. Signed-off-by: Andi Kleen <ak(a)linux.intel.com> Signed-off-by: Thomas Gleixner <tglx(a)linutronix.de> Reviewed-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> Acked-by: David Woodhouse <dwmw(a)amazon.co.uk> Cc: rusty(a)rustcorp.com.au Cc: arjan.van.de.ven(a)intel.com Cc: jeyu(a)kernel.org Cc: torvalds(a)linux-foundation.org Link: https://lkml.kernel.org/r/20180116205228.4890-1-andi@firstfloor.org Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- include/linux/vermagic.h | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) --- a/include/linux/vermagic.h +++ b/include/linux/vermagic.h @@ -24,10 +24,16 @@ #ifndef MODULE_ARCH_VERMAGIC #define MODULE_ARCH_VERMAGIC "" #endif +#ifdef RETPOLINE +#define MODULE_VERMAGIC_RETPOLINE "retpoline " +#else +#define MODULE_VERMAGIC_RETPOLINE "" +#endif #define VERMAGIC_STRING \ UTS_RELEASE " " \ MODULE_VERMAGIC_SMP MODULE_VERMAGIC_PREEMPT \ MODULE_VERMAGIC_MODULE_UNLOAD MODULE_VERMAGIC_MODVERSIONS \ - MODULE_ARCH_VERMAGIC + MODULE_ARCH_VERMAGIC \ + MODULE_VERMAGIC_RETPOLINE Patches currently in stable-queue which might be from ak(a)linux.intel.com are queue-4.4/x86-spectre-add-boot-time-option-to-select-spectre-v2-mitigation.patch queue-4.4/x86-retpoline-irq32-convert-assembler-indirect-jumps.patch queue-4.4/x86-retpoline-hyperv-convert-assembler-indirect-jumps.patch queue-4.4/x86-retpoline-entry-convert-entry-assembler-indirect-jumps.patch queue-4.4/x86-retpoline-ftrace-convert-ftrace-assembler-indirect-jumps.patch queue-4.4/x86-retpoline-crypto-convert-crypto-assembler-indirect-jumps.patch queue-4.4/module-add-retpoline-tag-to-vermagic.patch queue-4.4/x86-retpoline-xen-convert-xen-hypercall-indirect-jumps.patch queue-4.4/x86-retpoline-checksum32-convert-assembler-indirect-jumps.patch queue-4.4/x86-retpoline-fill-return-stack-buffer-on-vmexit.patch queue-4.4/x86-retpoline-add-lfence-to-the-retpoline-rsb-filling-rsb-macros.patch queue-4.4/x86-retpoline-remove-compile-time-warning.patch queue-4.4/x86-retpoline-add-initial-retpoline-support.patch

7 years, 1 month

1
0
0 0

[Linux-stable-mirror] Patch "x86/tsc: Future-proof native_calibrate_tsc()" has been added to the 4.14-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled x86/tsc: Future-proof native_calibrate_tsc() 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-tsc-future-proof-native_calibrate_tsc.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 da4ae6c4a0b8dee5a5377a385545d2250fa8cddb Mon Sep 17 00:00:00 2001 From: Len Brown <len.brown(a)intel.com> Date: Fri, 22 Dec 2017 00:27:54 -0500 Subject: x86/tsc: Future-proof native_calibrate_tsc() From: Len Brown <len.brown(a)intel.com> commit da4ae6c4a0b8dee5a5377a385545d2250fa8cddb upstream. If the crystal frequency cannot be determined via CPUID(15).crystal_khz or the built-in table then native_calibrate_tsc() will still set the X86_FEATURE_TSC_KNOWN_FREQ flag which prevents the refined TSC calibration. As a consequence such systems use cpu_khz for the TSC frequency which is incorrect when cpu_khz != tsc_khz resulting in time drift. Return early when the crystal frequency cannot be retrieved without setting the X86_FEATURE_TSC_KNOWN_FREQ flag. This ensures that the refined TSC calibration is invoked. [ tglx: Steam-blastered changelog. Sigh ] Fixes: 4ca4df0b7eb0 ("x86/tsc: Mark TSC frequency determined by CPUID as known") Signed-off-by: Len Brown <len.brown(a)intel.com> Signed-off-by: Thomas Gleixner <tglx(a)linutronix.de> Cc: peterz(a)infradead.org Cc: Bin Gao <bin.gao(a)intel.com> Link: https://lkml.kernel.org/r/0fe2503aa7d7fc69137141fc705541a78101d2b9.15139204… Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- arch/x86/kernel/tsc.c | 2 ++ 1 file changed, 2 insertions(+) --- a/arch/x86/kernel/tsc.c +++ b/arch/x86/kernel/tsc.c @@ -612,6 +612,8 @@ unsigned long native_calibrate_tsc(void) } } + if (crystal_khz == 0) + return 0; /* * TSC frequency determined by CPUID is a "hardware reported" * frequency and is the most accurate one so far we have. This Patches currently in stable-queue which might be from len.brown(a)intel.com are queue-4.14/x86-tsc-fix-erroneous-tsc-rate-on-skylake-xeon.patch queue-4.14/x86-tsc-future-proof-native_calibrate_tsc.patch

7 years, 1 month

1
0
0 0

[Linux-stable-mirror] Patch "x86/tsc: Fix erroneous TSC rate on Skylake Xeon" has been added to the 4.14-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled x86/tsc: Fix erroneous TSC rate on Skylake Xeon 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-tsc-fix-erroneous-tsc-rate-on-skylake-xeon.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 b511203093489eb1829cb4de86e8214752205ac6 Mon Sep 17 00:00:00 2001 From: Len Brown <len.brown(a)intel.com> Date: Fri, 22 Dec 2017 00:27:55 -0500 Subject: x86/tsc: Fix erroneous TSC rate on Skylake Xeon From: Len Brown <len.brown(a)intel.com> commit b511203093489eb1829cb4de86e8214752205ac6 upstream. The INTEL_FAM6_SKYLAKE_X hardcoded crystal_khz value of 25MHZ is problematic: - SKX workstations (with same model # as server variants) use a 24 MHz crystal. This results in a -4.0% time drift rate on SKX workstations. - SKX servers subject the crystal to an EMI reduction circuit that reduces its actual frequency by (approximately) -0.25%. This results in -1 second per 10 minute time drift as compared to network time. This issue can also trigger a timer and power problem, on configurations that use the LAPIC timer (versus the TSC deadline timer). Clock ticks scheduled with the LAPIC timer arrive a few usec before the time they are expected (according to the slow TSC). This causes Linux to poll-idle, when it should be in an idle power saving state. The idle and clock code do not graciously recover from this error, sometimes resulting in significant polling and measurable power impact. Stop using native_calibrate_tsc() for INTEL_FAM6_SKYLAKE_X. native_calibrate_tsc() will return 0, boot will run with tsc_khz = cpu_khz, and the TSC refined calibration will update tsc_khz to correct for the difference. [ tglx: Sanitized change log ] Fixes: 6baf3d61821f ("x86/tsc: Add additional Intel CPU models to the crystal quirk list") Signed-off-by: Len Brown <len.brown(a)intel.com> Signed-off-by: Thomas Gleixner <tglx(a)linutronix.de> Cc: peterz(a)infradead.org Cc: Prarit Bhargava <prarit(a)redhat.com> Link: https://lkml.kernel.org/r/ff6dcea166e8ff8f2f6a03c17beab2cb436aa779.15139204… Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- arch/x86/kernel/tsc.c | 1 - 1 file changed, 1 deletion(-) --- a/arch/x86/kernel/tsc.c +++ b/arch/x86/kernel/tsc.c @@ -602,7 +602,6 @@ unsigned long native_calibrate_tsc(void) case INTEL_FAM6_KABYLAKE_DESKTOP: crystal_khz = 24000; /* 24.0 MHz */ break; - case INTEL_FAM6_SKYLAKE_X: case INTEL_FAM6_ATOM_DENVERTON: crystal_khz = 25000; /* 25.0 MHz */ break; Patches currently in stable-queue which might be from len.brown(a)intel.com are queue-4.14/x86-tsc-fix-erroneous-tsc-rate-on-skylake-xeon.patch queue-4.14/x86-tsc-future-proof-native_calibrate_tsc.patch

7 years, 1 month

1
0
0 0

[Linux-stable-mirror] Patch "x86/retpoline: Fill RSB on context switch for affected CPUs" has been added to the 4.14-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled x86/retpoline: Fill RSB on context switch for affected CPUs 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-retpoline-fill-rsb-on-context-switch-for-affected-cpus.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 c995efd5a740d9cbafbf58bde4973e8b50b4d761 Mon Sep 17 00:00:00 2001 From: David Woodhouse <dwmw(a)amazon.co.uk> Date: Fri, 12 Jan 2018 17:49:25 +0000 Subject: x86/retpoline: Fill RSB on context switch for affected CPUs From: David Woodhouse <dwmw(a)amazon.co.uk> commit c995efd5a740d9cbafbf58bde4973e8b50b4d761 upstream. On context switch from a shallow call stack to a deeper one, as the CPU does 'ret' up the deeper side it may encounter RSB entries (predictions for where the 'ret' goes to) which were populated in userspace. This is problematic if neither SMEP nor KPTI (the latter of which marks userspace pages as NX for the kernel) are active, as malicious code in userspace may then be executed speculatively. Overwrite the CPU's return prediction stack with calls which are predicted to return to an infinite loop, to "capture" speculation if this happens. This is required both for retpoline, and also in conjunction with IBRS for !SMEP && !KPTI. On Skylake+ the problem is slightly different, and an *underflow* of the RSB may cause errant branch predictions to occur. So there it's not so much overwrite, as *filling* the RSB to attempt to prevent it getting empty. This is only a partial solution for Skylake+ since there are many other conditions which may result in the RSB becoming empty. The full solution on Skylake+ is to use IBRS, which will prevent the problem even when the RSB becomes empty. With IBRS, the RSB-stuffing will not be required on context switch. [ tglx: Added missing vendor check and slighty massaged comments and changelog ] Signed-off-by: David Woodhouse <dwmw(a)amazon.co.uk> Signed-off-by: Thomas Gleixner <tglx(a)linutronix.de> Acked-by: Arjan van de Ven <arjan(a)linux.intel.com> Cc: gnomes(a)lxorguk.ukuu.org.uk Cc: Rik van Riel <riel(a)redhat.com> Cc: Andi Kleen <ak(a)linux.intel.com> Cc: Josh Poimboeuf <jpoimboe(a)redhat.com> Cc: thomas.lendacky(a)amd.com Cc: Peter Zijlstra <peterz(a)infradead.org> Cc: Linus Torvalds <torvalds(a)linux-foundation.org> Cc: Jiri Kosina <jikos(a)kernel.org> Cc: Andy Lutomirski <luto(a)amacapital.net> Cc: Dave Hansen <dave.hansen(a)intel.com> Cc: Kees Cook <keescook(a)google.com> Cc: Tim Chen <tim.c.chen(a)linux.intel.com> Cc: Greg Kroah-Hartman <gregkh(a)linux-foundation.org> Cc: Paul Turner <pjt(a)google.com> Link: https://lkml.kernel.org/r/1515779365-9032-1-git-send-email-dwmw@amazon.co.uk Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- arch/x86/entry/entry_32.S | 11 +++++++++++ arch/x86/entry/entry_64.S | 11 +++++++++++ arch/x86/include/asm/cpufeatures.h | 1 + arch/x86/kernel/cpu/bugs.c | 36 ++++++++++++++++++++++++++++++++++++ 4 files changed, 59 insertions(+) --- a/arch/x86/entry/entry_32.S +++ b/arch/x86/entry/entry_32.S @@ -244,6 +244,17 @@ ENTRY(__switch_to_asm) movl %ebx, PER_CPU_VAR(stack_canary)+stack_canary_offset #endif +#ifdef CONFIG_RETPOLINE + /* + * When switching from a shallower to a deeper call stack + * the RSB may either underflow or use entries populated + * with userspace addresses. On CPUs where those concerns + * exist, overwrite the RSB with entries which capture + * speculative execution to prevent attack. + */ + FILL_RETURN_BUFFER %ebx, RSB_CLEAR_LOOPS, X86_FEATURE_RSB_CTXSW +#endif + /* restore callee-saved registers */ popl %esi popl %edi --- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -487,6 +487,17 @@ ENTRY(__switch_to_asm) movq %rbx, PER_CPU_VAR(irq_stack_union)+stack_canary_offset #endif +#ifdef CONFIG_RETPOLINE + /* + * When switching from a shallower to a deeper call stack + * the RSB may either underflow or use entries populated + * with userspace addresses. On CPUs where those concerns + * exist, overwrite the RSB with entries which capture + * speculative execution to prevent attack. + */ + FILL_RETURN_BUFFER %r12, RSB_CLEAR_LOOPS, X86_FEATURE_RSB_CTXSW +#endif + /* restore callee-saved registers */ popq %r15 popq %r14 --- a/arch/x86/include/asm/cpufeatures.h +++ b/arch/x86/include/asm/cpufeatures.h @@ -211,6 +211,7 @@ #define X86_FEATURE_AVX512_4FMAPS ( 7*32+17) /* AVX-512 Multiply Accumulation Single precision */ #define X86_FEATURE_MBA ( 7*32+18) /* Memory Bandwidth Allocation */ +#define X86_FEATURE_RSB_CTXSW ( 7*32+19) /* Fill RSB on context switches */ /* Virtualization flags: Linux defined, word 8 */ #define X86_FEATURE_TPR_SHADOW ( 8*32+ 0) /* Intel TPR Shadow */ --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -23,6 +23,7 @@ #include <asm/alternative.h> #include <asm/pgtable.h> #include <asm/set_memory.h> +#include <asm/intel-family.h> static void __init spectre_v2_select_mitigation(void); @@ -155,6 +156,23 @@ disable: return SPECTRE_V2_CMD_NONE; } +/* Check for Skylake-like CPUs (for RSB handling) */ +static bool __init is_skylake_era(void) +{ + if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL && + boot_cpu_data.x86 == 6) { + switch (boot_cpu_data.x86_model) { + case INTEL_FAM6_SKYLAKE_MOBILE: + case INTEL_FAM6_SKYLAKE_DESKTOP: + case INTEL_FAM6_SKYLAKE_X: + case INTEL_FAM6_KABYLAKE_MOBILE: + case INTEL_FAM6_KABYLAKE_DESKTOP: + return true; + } + } + return false; +} + static void __init spectre_v2_select_mitigation(void) { enum spectre_v2_mitigation_cmd cmd = spectre_v2_parse_cmdline(); @@ -213,6 +231,24 @@ retpoline_auto: spectre_v2_enabled = mode; pr_info("%s\n", spectre_v2_strings[mode]); + + /* + * If neither SMEP or KPTI are available, there is a risk of + * hitting userspace addresses in the RSB after a context switch + * from a shallow call stack to a deeper one. To prevent this fill + * the entire RSB, even when using IBRS. + * + * Skylake era CPUs have a separate issue with *underflow* of the + * RSB, when they will predict 'ret' targets from the generic BTB. + * The proper mitigation for this is IBRS. If IBRS is not supported + * or deactivated in favour of retpolines the RSB fill on context + * switch is required. + */ + if ((!boot_cpu_has(X86_FEATURE_PTI) && + !boot_cpu_has(X86_FEATURE_SMEP)) || is_skylake_era()) { + setup_force_cpu_cap(X86_FEATURE_RSB_CTXSW); + pr_info("Filling RSB on context switch\n"); + } } #undef pr_fmt Patches currently in stable-queue which might be from dwmw(a)amazon.co.uk are queue-4.14/module-add-retpoline-tag-to-vermagic.patch queue-4.14/x86-retpoline-fill-rsb-on-context-switch-for-affected-cpus.patch queue-4.14/x86-retpoline-add-lfence-to-the-retpoline-rsb-filling-rsb-macros.patch

7 years, 1 month

1
0
0 0

2025

2024

2023

2022

2021

2020

2019

2018

2017

Linux-stable-mirror