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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 3a020f7..bc4a683 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,
kcb->kprobe_saved_eflags &= ~IF_MASK;
}
+static __always_inline void clear_btf(void)
+{
+ if (test_thread_flag(TIF_DEBUGCTLMSR))
+ wrmsr(MSR_IA32_DEBUGCTLMSR, 0, 0);
+}
+
+static __always_inline void restore_btf(void)
+{
+ if (test_thread_flag(TIF_DEBUGCTLMSR))
+ wrmsr(MSR_IA32_DEBUGCTLMSR, current->thread.debugctlmsr, 0);
+}
+
static void __kprobes prepare_singlestep(struct kprobe *p, struct pt_regs *regs)
{
+ clear_btf();
regs->eflags |= TF_MASK;
regs->eflags &= ~IF_MASK;
/*single step inline if the instruction is an int3*/
@@ -542,6 +555,8 @@ static void __kprobes resume_execution(struct kprobe *p,
regs->eip = orig_eip + (regs->eip - copy_eip);
no_change:
+ restore_btf();
+
return;
}