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Diffstat (limited to 'arch/x86/kernel/kprobes_32.c')
-rw-r--r--arch/x86/kernel/kprobes_32.c15
1 files changed, 15 insertions, 0 deletions
diff --git a/arch/x86/kernel/kprobes_32.c b/arch/x86/kernel/kprobes_32.c
index 3a020f79f82b..bc4a68367cd0 100644
--- a/arch/x86/kernel/kprobes_32.c
+++ b/arch/x86/kernel/kprobes_32.c
@@ -217,8 +217,21 @@ static void __kprobes set_current_kprobe(struct kprobe *p, struct pt_regs *regs,
217 kcb->kprobe_saved_eflags &= ~IF_MASK; 217 kcb->kprobe_saved_eflags &= ~IF_MASK;
218} 218}
219 219
220static __always_inline void clear_btf(void)
221{
222 if (test_thread_flag(TIF_DEBUGCTLMSR))
223 wrmsr(MSR_IA32_DEBUGCTLMSR, 0, 0);
224}
225
226static __always_inline void restore_btf(void)
227{
228 if (test_thread_flag(TIF_DEBUGCTLMSR))
229 wrmsr(MSR_IA32_DEBUGCTLMSR, current->thread.debugctlmsr, 0);
230}
231
220static void __kprobes prepare_singlestep(struct kprobe *p, struct pt_regs *regs) 232static void __kprobes prepare_singlestep(struct kprobe *p, struct pt_regs *regs)
221{ 233{
234 clear_btf();
222 regs->eflags |= TF_MASK; 235 regs->eflags |= TF_MASK;
223 regs->eflags &= ~IF_MASK; 236 regs->eflags &= ~IF_MASK;
224 /*single step inline if the instruction is an int3*/ 237 /*single step inline if the instruction is an int3*/
@@ -542,6 +555,8 @@ static void __kprobes resume_execution(struct kprobe *p,
542 regs->eip = orig_eip + (regs->eip - copy_eip); 555 regs->eip = orig_eip + (regs->eip - copy_eip);
543 556
544no_change: 557no_change:
558 restore_btf();
559
545 return; 560 return;
546} 561}
547 562