From e4fb43902a0b2e76926b19a90c89f9be229b656a Mon Sep 17 00:00:00 2001 From: Andy Whitcroft Date: Tue, 20 Feb 2018 13:53:31 +0000 Subject: [PATCH 008/131] Revert "UBUNTU: SAUCE: x86/cpu/AMD: Remove now unused definition of MFENCE_RDTSC feature" CVE-2017-5753 (revert embargoed) CVE-2017-5715 (revert embargoed) This reverts commit 5a9fc7213b0fe87816f968ed6100a8dec0738331. Signed-off-by: Andy Whitcroft --- arch/x86/include/asm/barrier.h | 4 +++- arch/x86/include/asm/cpufeature.h | 2 +- arch/x86/um/asm/barrier.h | 1 + 3 files changed, 5 insertions(+), 2 deletions(-) diff --git a/arch/x86/include/asm/barrier.h b/arch/x86/include/asm/barrier.h index eb5aa1cbcef1..90be66de9bb2 100644 --- a/arch/x86/include/asm/barrier.h +++ b/arch/x86/include/asm/barrier.h @@ -24,7 +24,8 @@ #define wmb() asm volatile("sfence" ::: "memory") #endif -#define gmb() alternative("", "lfence", X86_FEATURE_LFENCE_RDTSC); +#define gmb() alternative_2("", "mfence", X86_FEATURE_MFENCE_RDTSC, \ + "lfence", X86_FEATURE_LFENCE_RDTSC); /** * read_barrier_depends - Flush all pending reads that subsequents reads @@ -152,6 +153,7 @@ do { \ */ static __always_inline void rdtsc_barrier(void) { + alternative(ASM_NOP3, "mfence", X86_FEATURE_MFENCE_RDTSC); alternative(ASM_NOP3, "lfence", X86_FEATURE_LFENCE_RDTSC); } diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h index 7e89e296b911..9717149e476d 100644 --- a/arch/x86/include/asm/cpufeature.h +++ b/arch/x86/include/asm/cpufeature.h @@ -88,7 +88,7 @@ #define X86_FEATURE_SYSCALL32 (3*32+14) /* "" syscall in ia32 userspace */ #define X86_FEATURE_SYSENTER32 (3*32+15) /* "" sysenter in ia32 userspace */ #define X86_FEATURE_REP_GOOD (3*32+16) /* rep microcode works well */ - +#define X86_FEATURE_MFENCE_RDTSC (3*32+17) /* "" Mfence synchronizes RDTSC */ #define X86_FEATURE_LFENCE_RDTSC (3*32+18) /* "" Lfence synchronizes RDTSC */ #define X86_FEATURE_11AP (3*32+19) /* "" Bad local APIC aka 11AP */ #define X86_FEATURE_NOPL (3*32+20) /* The NOPL (0F 1F) instructions */ diff --git a/arch/x86/um/asm/barrier.h b/arch/x86/um/asm/barrier.h index 14634ffc6f0e..7d01b8c56c00 100644 --- a/arch/x86/um/asm/barrier.h +++ b/arch/x86/um/asm/barrier.h @@ -68,6 +68,7 @@ */ static inline void rdtsc_barrier(void) { + alternative(ASM_NOP3, "mfence", X86_FEATURE_MFENCE_RDTSC); alternative(ASM_NOP3, "lfence", X86_FEATURE_LFENCE_RDTSC); } -- 2.15.1