diff options
Diffstat (limited to 'arch/x86/include/asm/switch_to.h')
| -rw-r--r-- | arch/x86/include/asm/switch_to.h | 31 |
1 files changed, 28 insertions, 3 deletions
diff --git a/arch/x86/include/asm/switch_to.h b/arch/x86/include/asm/switch_to.h index 899084b70412..eb5f7999a893 100644 --- a/arch/x86/include/asm/switch_to.h +++ b/arch/x86/include/asm/switch_to.h @@ -2,6 +2,8 @@ #ifndef _ASM_X86_SWITCH_TO_H #define _ASM_X86_SWITCH_TO_H +#include <linux/sched/task_stack.h> + struct task_struct; /* one of the stranger aspects of C forward declarations */ struct task_struct *__switch_to_asm(struct task_struct *prev, @@ -14,8 +16,7 @@ void __switch_to_xtra(struct task_struct *prev_p, struct task_struct *next_p, struct tss_struct *tss); /* This runs runs on the previous thread's stack. */ -static inline void prepare_switch_to(struct task_struct *prev, - struct task_struct *next) +static inline void prepare_switch_to(struct task_struct *next) { #ifdef CONFIG_VMAP_STACK /* @@ -68,9 +69,33 @@ struct fork_frame { #define switch_to(prev, next, last) \ do { \ - prepare_switch_to(prev, next); \ + prepare_switch_to(next); \ \ ((last) = __switch_to_asm((prev), (next))); \ } while (0) +#ifdef CONFIG_X86_32 +static inline void refresh_sysenter_cs(struct thread_struct *thread) +{ + /* Only happens when SEP is enabled, no need to test "SEP"arately: */ + if (unlikely(this_cpu_read(cpu_tss_rw.x86_tss.ss1) == thread->sysenter_cs)) + return; + + this_cpu_write(cpu_tss_rw.x86_tss.ss1, thread->sysenter_cs); + wrmsr(MSR_IA32_SYSENTER_CS, thread->sysenter_cs, 0); +} +#endif + +/* This is used when switching tasks or entering/exiting vm86 mode. */ +static inline void update_sp0(struct task_struct *task) +{ + /* On x86_64, sp0 always points to the entry trampoline stack, which is constant: */ +#ifdef CONFIG_X86_32 + load_sp0(task->thread.sp0); +#else + if (static_cpu_has(X86_FEATURE_XENPV)) + load_sp0(task_top_of_stack(task)); +#endif +} + #endif /* _ASM_X86_SWITCH_TO_H */ |