Messages in this thread Patch in this message | | | Date | Sun, 24 Jun 2018 13:29:00 +0200 (CEST) | From | Thomas Gleixner <> | Subject | [GIT pull] x86 pti updates for 4.18 |
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Linus,
please pull the latest x86-pti-for-linus git tree from:
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86-pti-for-linus
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.
Thanks,
tglx
------------------> Dan Williams (1): x86/spectre_v1: Disable compiler optimizations over array_index_mask_nospec()
Jiri Kosina (1): x86/pti: Don't report XenPV as vulnerable
arch/x86/include/asm/barrier.h | 2 +- arch/x86/kernel/cpu/bugs.c | 4 ++++ 2 files changed, 5 insertions(+), 1 deletion(-)
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:
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