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-rw-r--r--arch/x86/kernel/process_32.c37
1 files changed, 25 insertions, 12 deletions
diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c
index 5cec8a75a4e8..496ea3110aa2 100644
--- a/arch/x86/kernel/process_32.c
+++ b/arch/x86/kernel/process_32.c
@@ -484,20 +484,13 @@ int set_tsc_mode(unsigned int val)
484 return 0; 484 return 0;
485} 485}
486 486
487static noinline void 487#ifdef CONFIG_X86_DS
488__switch_to_xtra(struct task_struct *prev_p, struct task_struct *next_p, 488static int update_debugctl(struct thread_struct *prev,
489 struct tss_struct *tss) 489 struct thread_struct *next, unsigned long debugctl)
490{ 490{
491 struct thread_struct *prev, *next; 491 unsigned long ds_prev = 0;
492 unsigned long debugctl; 492 unsigned long ds_next = 0;
493 unsigned long ds_prev = 0, ds_next = 0;
494 493
495 prev = &prev_p->thread;
496 next = &next_p->thread;
497
498 debugctl = prev->debugctlmsr;
499
500#ifdef CONFIG_X86_DS
501 if (prev->ds_ctx) 494 if (prev->ds_ctx)
502 ds_prev = (unsigned long)prev->ds_ctx->ds; 495 ds_prev = (unsigned long)prev->ds_ctx->ds;
503 if (next->ds_ctx) 496 if (next->ds_ctx)
@@ -510,8 +503,28 @@ __switch_to_xtra(struct task_struct *prev_p, struct task_struct *next_p,
510 update_debugctlmsr(0); 503 update_debugctlmsr(0);
511 wrmsr(MSR_IA32_DS_AREA, ds_next, 0); 504 wrmsr(MSR_IA32_DS_AREA, ds_next, 0);
512 } 505 }
506 return debugctl;
507}
508#else
509static int update_debugctl(struct thread_struct *prev,
510 struct thread_struct *next, unsigned long debugctl)
511{
512 return debugctl;
513}
513#endif /* CONFIG_X86_DS */ 514#endif /* CONFIG_X86_DS */
514 515
516static noinline void
517__switch_to_xtra(struct task_struct *prev_p, struct task_struct *next_p,
518 struct tss_struct *tss)
519{
520 struct thread_struct *prev, *next;
521 unsigned long debugctl;
522
523 prev = &prev_p->thread;
524 next = &next_p->thread;
525
526 debugctl = update_debugctl(prev, next, prev->debugctlmsr);
527
515 if (next->debugctlmsr != debugctl) 528 if (next->debugctlmsr != debugctl)
516 update_debugctlmsr(next->debugctlmsr); 529 update_debugctlmsr(next->debugctlmsr);
517 530