diff options
Diffstat (limited to 'arch/x86/kernel/process.c')
| -rw-r--r-- | arch/x86/kernel/process.c | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index 03408b942adb..397342725046 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -38,6 +38,7 @@ #include <asm/switch_to.h> #include <asm/desc.h> #include <asm/prctl.h> +#include <asm/spec-ctrl.h> /* * per-CPU TSS segments. Threads are completely 'soft' on Linux, @@ -278,6 +279,24 @@ static inline void switch_to_bitmap(struct tss_struct *tss, } } +static __always_inline void __speculative_store_bypass_update(unsigned long tifn) +{ + u64 msr; + + if (static_cpu_has(X86_FEATURE_AMD_RDS)) { + msr = x86_amd_ls_cfg_base | rds_tif_to_amd_ls_cfg(tifn); + wrmsrl(MSR_AMD64_LS_CFG, msr); + } else { + msr = x86_spec_ctrl_base | rds_tif_to_spec_ctrl(tifn); + wrmsrl(MSR_IA32_SPEC_CTRL, msr); + } +} + +void speculative_store_bypass_update(void) +{ + __speculative_store_bypass_update(current_thread_info()->flags); +} + void __switch_to_xtra(struct task_struct *prev_p, struct task_struct *next_p, struct tss_struct *tss) { @@ -309,6 +328,9 @@ void __switch_to_xtra(struct task_struct *prev_p, struct task_struct *next_p, if ((tifp ^ tifn) & _TIF_NOCPUID) set_cpuid_faulting(!!(tifn & _TIF_NOCPUID)); + + if ((tifp ^ tifn) & _TIF_RDS) + __speculative_store_bypass_update(tifn); } /* |