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-rw-r--r--arch/x86/kernel/kprobes_64.c14
1 files changed, 14 insertions, 0 deletions
diff --git a/arch/x86/kernel/kprobes_64.c b/arch/x86/kernel/kprobes_64.c
index 5df19a9f9239..10d66e323c7d 100644
--- a/arch/x86/kernel/kprobes_64.c
+++ b/arch/x86/kernel/kprobes_64.c
@@ -256,8 +256,21 @@ static void __kprobes set_current_kprobe(struct kprobe *p, struct pt_regs *regs,
256 kcb->kprobe_saved_rflags &= ~IF_MASK; 256 kcb->kprobe_saved_rflags &= ~IF_MASK;
257} 257}
258 258
259static __always_inline void clear_btf(void)
260{
261 if (test_thread_flag(TIF_DEBUGCTLMSR))
262 wrmsrl(MSR_IA32_DEBUGCTLMSR, 0);
263}
264
265static __always_inline void restore_btf(void)
266{
267 if (test_thread_flag(TIF_DEBUGCTLMSR))
268 wrmsrl(MSR_IA32_DEBUGCTLMSR, current->thread.debugctlmsr);
269}
270
259static void __kprobes prepare_singlestep(struct kprobe *p, struct pt_regs *regs) 271static void __kprobes prepare_singlestep(struct kprobe *p, struct pt_regs *regs)
260{ 272{
273 clear_btf();
261 regs->eflags |= TF_MASK; 274 regs->eflags |= TF_MASK;
262 regs->eflags &= ~IF_MASK; 275 regs->eflags &= ~IF_MASK;
263 /*single step inline if the instruction is an int3*/ 276 /*single step inline if the instruction is an int3*/
@@ -527,6 +540,7 @@ static void __kprobes resume_execution(struct kprobe *p,
527 540
528 regs->rip = orig_rip + (regs->rip - copy_rip); 541 regs->rip = orig_rip + (regs->rip - copy_rip);
529no_change: 542no_change:
543 restore_btf();
530 544
531 return; 545 return;
532} 546}