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[PATCH -tip v4 2/3] tracepoint: Add signal deliver event
- From: Masami Hiramatsu <mhiramat at redhat dot com>
- To: Ingo Molnar <mingo at elte dot hu>, lkml<linux-kernel at vger dot kernel dot org>
- Cc: Jason Baron <jbaron at redhat dot com>, Roland McGrath <roland at redhat dot com>, systemtap<systemtap at sources dot redhat dot com>, DLE<dle-develop at lists dot sourceforge dot net>, Masami Hiramatsu <mhiramat at redhat dot com>, Oleg Nesterov <oleg at redhat dot com>, Roland McGrath <roland at redhat dot com>, Ingo Molnar <mingo at elte dot hu>
- Date: Tue, 24 Nov 2009 16:56:51 -0500
- Subject: [PATCH -tip v4 2/3] tracepoint: Add signal deliver event
- References: <20091124215638.30449.3838.stgit@dhcp-100-2-132.bos.redhat.com>
Add a tracepoint where a process gets a signal. This tracepoint
shows signal-number, sa-handler and sa-flag.
Changes in v3:
- Add docbook style comments
Changes in v2:
- Add siginfo argument
- Fix comment
Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Reviewed-by: Jason Baron <jbaron@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
---
include/trace/events/signal.h | 39 +++++++++++++++++++++++++++++++++++++++
kernel/signal.c | 3 +++
2 files changed, 42 insertions(+), 0 deletions(-)
diff --git a/include/trace/events/signal.h b/include/trace/events/signal.h
index ef51756..a6d71de 100644
--- a/include/trace/events/signal.h
+++ b/include/trace/events/signal.h
@@ -60,6 +60,45 @@ TRACE_EVENT(signal_generate,
__entry->comm, __entry->pid)
);
+/**
+ * signal_deliver - called when a signal is delivered
+ * @sig: signal number
+ * @info: pointer to struct siginfo
+ * @ka: pointer to struct k_sigaction
+ *
+ * A 'sig' signal is delivered to current process with 'info' siginfo,
+ * and it will be handled by 'ka'. ka->sa.sa_handler can be SIG_IGN or
+ * SIG_DFL.
+ * Note that some signals reported by signal_generate tracepoint can be
+ * lost, ignored or modified (by debugger) before hitting this tracepoint.
+ * This means, this can show which signals are actually delivered, but
+ * matching generated signals and delivered signals may not be correct.
+ */
+TRACE_EVENT(signal_deliver,
+
+ TP_PROTO(int sig, struct siginfo *info, struct k_sigaction *ka),
+
+ TP_ARGS(sig, info, ka),
+
+ TP_STRUCT__entry(
+ __field( int, sig )
+ __field( int, errno )
+ __field( int, code )
+ __field( unsigned long, sa_handler )
+ __field( unsigned long, sa_flags )
+ ),
+
+ TP_fast_assign(
+ __entry->sig = sig;
+ TP_STORE_SIGINFO(__entry, info);
+ __entry->sa_handler = (unsigned long)ka->sa.sa_handler;
+ __entry->sa_flags = ka->sa.sa_flags;
+ ),
+
+ TP_printk("sig=%d errno=%d code=%d sa_handler=%lx sa_flags=%lx",
+ __entry->sig, __entry->errno, __entry->code,
+ __entry->sa_handler, __entry->sa_flags)
+);
#endif /* _TRACE_SIGNAL_H */
/* This part must be outside protection */
diff --git a/kernel/signal.c b/kernel/signal.c
index 54ac4c5..d518984 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -1860,6 +1860,9 @@ relock:
ka = &sighand->action[signr-1];
}
+ /* Trace actually delivered signals. */
+ trace_signal_deliver(signr, info, ka);
+
if (ka->sa.sa_handler == SIG_IGN) /* Do nothing. */
continue;
if (ka->sa.sa_handler != SIG_DFL) {
--
Masami Hiramatsu
Software Engineer
Hitachi Computer Products (America), Inc.
Software Solutions Division
e-mail: mhiramat@redhat.com