Commit-ID: 6a5022a56ac37da7bffece043331a101ed0040b1 Gitweb: http://git.kernel.org/tip/6a5022a56ac37da7bffece043331a101ed0040b1 Author: Masami Hiramatsu <masami.hiramatsu...@hitachi.com> AuthorDate: Thu, 17 Apr 2014 17:16:51 +0900 Committer: Ingo Molnar <mi...@kernel.org> CommitDate: Thu, 24 Apr 2014 10:02:55 +0200
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...@hitachi.com> Reviewed-by: Steven Rostedt <rost...@goodmis.org> Cc: Jiri Kosina <jkos...@suse.cz> Cc: Jonathan Lebon <jle...@redhat.com> Link: http://lkml.kernel.org/r/20140417081651.26341.10593.st...@ltc230.yrl.intra.hitachi.co.jp Signed-off-by: Ingo Molnar <mi...@kernel.org> --- arch/x86/kernel/kprobes/core.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c index 61b17dc..da7bdaa 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. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
