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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2016-06-25 06:49:32 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-06-25 06:49:32 -0700 |
| commit | 9a949a98596c45763299158b9018f3491e3cbf99 (patch) | |
| tree | fd7943339a39997d2906f1951ee2565e175be3c7 | |
| parent | 57801c1b817128cbb3a4dc45e6a1e0e31a227a19 (diff) | |
| parent | dcfc47248d3f7d28df6f531e6426b933de94370d (diff) | |
| download | linux-9a949a98596c45763299158b9018f3491e3cbf99.tar.bz2 | |
Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 kprobe fix from Thomas Gleixner:
"A single fix clearing the TF bit when a fault is single stepped"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
kprobes/x86: Clear TF bit in fault on single-stepping
| -rw-r--r-- | arch/x86/kernel/kprobes/core.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c index 38cf7a741250..7847e5c0e0b5 100644 --- a/arch/x86/kernel/kprobes/core.c +++ b/arch/x86/kernel/kprobes/core.c @@ -961,7 +961,19 @@ int kprobe_fault_handler(struct pt_regs *regs, int trapnr) * normal page fault. */ regs->ip = (unsigned long)cur->addr; + /* + * Trap flag (TF) has been set here because this fault + * happened where the single stepping will be done. + * So clear it by resetting the current kprobe: + */ + regs->flags &= ~X86_EFLAGS_TF; + + /* + * If the TF flag was set before the kprobe hit, + * don't touch it: + */ regs->flags |= kcb->kprobe_old_flags; + if (kcb->kprobe_status == KPROBE_REENTER) restore_previous_kprobe(kcb); else |