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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2018-06-24 13:48:30 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-06-24 13:48:30 +0200 |
| commit | 177d363e720c9a940282a295acbd36c2657cc279 (patch) | |
| tree | 69141a102f050cc2c3cdd621e6fc0a83b318bd19 | |
| parent | Merge branch 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux... (diff) | |
| parent | x86/spectre_v1: Disable compiler optimizations over array_index_mask_nospec() (diff) | |
| download | linux-177d363e720c9a940282a295acbd36c2657cc279.tar.xz linux-177d363e720c9a940282a295acbd36c2657cc279.zip | |
Merge branch 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 pti fixes from Thomas Gleixner:
"Two small updates for the speculative distractions:
- Make it more clear to the compiler that array_index_mask_nospec()
is not subject for optimizations. It's not perfect, but ...
- Don't report XEN PV guests as vulnerable because their mitigation
state depends on the hypervisor. Report unknown and refer to the
hypervisor requirement"
* 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/spectre_v1: Disable compiler optimizations over array_index_mask_nospec()
x86/pti: Don't report XenPV as vulnerable
| -rw-r--r-- | arch/x86/include/asm/barrier.h | 2 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/bugs.c | 4 |
2 files changed, 5 insertions, 1 deletions
diff --git a/arch/x86/include/asm/barrier.h b/arch/x86/include/asm/barrier.h index 042b5e892ed1..14de0432d288 100644 --- a/arch/x86/include/asm/barrier.h +++ b/arch/x86/include/asm/barrier.h @@ -38,7 +38,7 @@ static inline unsigned long array_index_mask_nospec(unsigned long index, { unsigned long mask; - asm ("cmp %1,%2; sbb %0,%0;" + asm volatile ("cmp %1,%2; sbb %0,%0;" :"=r" (mask) :"g"(size),"r" (index) :"cc"); diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c index cd0fda1fff6d..404df26b7de8 100644 --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -27,6 +27,7 @@ #include <asm/pgtable.h> #include <asm/set_memory.h> #include <asm/intel-family.h> +#include <asm/hypervisor.h> static void __init spectre_v2_select_mitigation(void); static void __init ssb_select_mitigation(void); @@ -664,6 +665,9 @@ static ssize_t cpu_show_common(struct device *dev, struct device_attribute *attr if (boot_cpu_has(X86_FEATURE_PTI)) return sprintf(buf, "Mitigation: PTI\n"); + if (hypervisor_is_type(X86_HYPER_XEN_PV)) + return sprintf(buf, "Unknown (XEN PV detected, hypervisor mitigation required)\n"); + break; case X86_BUG_SPECTRE_V1: |