diff options
Diffstat (limited to 'arch/x86/include/asm')
| -rw-r--r-- | arch/x86/include/asm/irqflags.h | 4 | ||||
| -rw-r--r-- | arch/x86/include/asm/mwait.h | 7 | ||||
| -rw-r--r-- | arch/x86/include/asm/nospec-branch.h | 12 |
3 files changed, 23 insertions, 0 deletions
diff --git a/arch/x86/include/asm/irqflags.h b/arch/x86/include/asm/irqflags.h index 058e40fed167..8a0e56e1dcc9 100644 --- a/arch/x86/include/asm/irqflags.h +++ b/arch/x86/include/asm/irqflags.h @@ -6,6 +6,8 @@ #ifndef __ASSEMBLY__ +#include <asm/nospec-branch.h> + /* Provide __cpuidle; we can't safely include <linux/cpu.h> */ #define __cpuidle __attribute__((__section__(".cpuidle.text"))) @@ -54,11 +56,13 @@ static inline void native_irq_enable(void) static inline __cpuidle void native_safe_halt(void) { + mds_idle_clear_cpu_buffers(); asm volatile("sti; hlt": : :"memory"); } static inline __cpuidle void native_halt(void) { + mds_idle_clear_cpu_buffers(); asm volatile("hlt": : :"memory"); } diff --git a/arch/x86/include/asm/mwait.h b/arch/x86/include/asm/mwait.h index 39a2fb29378a..eb0f80ce8524 100644 --- a/arch/x86/include/asm/mwait.h +++ b/arch/x86/include/asm/mwait.h @@ -6,6 +6,7 @@ #include <linux/sched/idle.h> #include <asm/cpufeature.h> +#include <asm/nospec-branch.h> #define MWAIT_SUBSTATE_MASK 0xf #define MWAIT_CSTATE_MASK 0xf @@ -40,6 +41,8 @@ static inline void __monitorx(const void *eax, unsigned long ecx, static inline void __mwait(unsigned long eax, unsigned long ecx) { + mds_idle_clear_cpu_buffers(); + /* "mwait %eax, %ecx;" */ asm volatile(".byte 0x0f, 0x01, 0xc9;" :: "a" (eax), "c" (ecx)); @@ -74,6 +77,8 @@ static inline void __mwait(unsigned long eax, unsigned long ecx) static inline void __mwaitx(unsigned long eax, unsigned long ebx, unsigned long ecx) { + /* No MDS buffer clear as this is AMD/HYGON only */ + /* "mwaitx %eax, %ebx, %ecx;" */ asm volatile(".byte 0x0f, 0x01, 0xfb;" :: "a" (eax), "b" (ebx), "c" (ecx)); @@ -81,6 +86,8 @@ static inline void __mwaitx(unsigned long eax, unsigned long ebx, static inline void __sti_mwait(unsigned long eax, unsigned long ecx) { + mds_idle_clear_cpu_buffers(); + trace_hardirqs_on(); /* "mwait %eax, %ecx;" */ asm volatile("sti; .byte 0x0f, 0x01, 0xc9;" diff --git a/arch/x86/include/asm/nospec-branch.h b/arch/x86/include/asm/nospec-branch.h index 65b747286d96..4e970390110f 100644 --- a/arch/x86/include/asm/nospec-branch.h +++ b/arch/x86/include/asm/nospec-branch.h @@ -319,6 +319,7 @@ DECLARE_STATIC_KEY_FALSE(switch_mm_cond_ibpb); DECLARE_STATIC_KEY_FALSE(switch_mm_always_ibpb); DECLARE_STATIC_KEY_FALSE(mds_user_clear); +DECLARE_STATIC_KEY_FALSE(mds_idle_clear); #include <asm/segment.h> @@ -356,6 +357,17 @@ static inline void mds_user_clear_cpu_buffers(void) mds_clear_cpu_buffers(); } +/** + * mds_idle_clear_cpu_buffers - Mitigation for MDS vulnerability + * + * Clear CPU buffers if the corresponding static key is enabled + */ +static inline void mds_idle_clear_cpu_buffers(void) +{ + if (static_branch_likely(&mds_idle_clear)) + mds_clear_cpu_buffers(); +} + #endif /* __ASSEMBLY__ */ /* |