diff options
| author | Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> | 2014-04-17 17:16:51 +0900 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2014-04-24 10:02:55 +0200 |
| commit | 6a5022a56ac37da7bffece043331a101ed0040b1 (patch) | |
| tree | efe8e5aadff08546e7a2836bf992961601a2d213 | |
| parent | 4d0fa8a0f01272d4de33704f20303dcecdb55df1 (diff) | |
kprobes/x86: Allow to handle reentered kprobe on single-stepping
Since the NMI handlers(e.g. perf) can interrupt in the
single stepping (or preparing the single stepping, do_debug
etc.), we should consider a kprobe is hit in the NMI
handler. Even in that case, the kprobe is allowed to be
reentered as same as the kprobes hit in kprobe handlers
(KPROBE_HIT_ACTIVE or KPROBE_HIT_SSDONE).
The real issue will happen when a kprobe hit while another
reentered kprobe is processing (KPROBE_REENTER), because
we already consumed a saved-area for the previous kprobe.
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Jonathan Lebon <jlebon@redhat.com>
Link: http://lkml.kernel.org/r/20140417081651.26341.10593.stgit@ltc230.yrl.intra.hitachi.co.jp
Signed-off-by: Ingo Molnar <mingo@kernel.org>
| -rw-r--r-- | arch/x86/kernel/kprobes/core.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c index 61b17dc2c277..da7bdaa3ce15 100644 --- a/arch/x86/kernel/kprobes/core.c +++ b/arch/x86/kernel/kprobes/core.c @@ -531,10 +531,11 @@ reenter_kprobe(struct kprobe *p, struct pt_regs *regs, struct kprobe_ctlblk *kcb switch (kcb->kprobe_status) { case KPROBE_HIT_SSDONE: case KPROBE_HIT_ACTIVE: + case KPROBE_HIT_SS: kprobes_inc_nmissed_count(p); setup_singlestep(p, regs, kcb, 1); break; - case KPROBE_HIT_SS: + case KPROBE_REENTER: /* A probe has been hit in the codepath leading up to, or just * after, single-stepping of a probed instruction. This entire * codepath should strictly reside in .kprobes.text section. |