[PATCH -tip v2 0/3] tracepoint: Add signal events

[PATCH -tip v2 0/3] tracepoint: Add signal events

[Masami Hiramatsu]

Hi,

These patches add signal related tracepoints including
signal generation, delivery, and loss. First patch also
moves signal-sending tracepoint from events/sched.h to
events/signal.h.

Changes in v2
- Add siginfo arguments

Thank you,

---

Masami Hiramatsu (3):
      tracepoint: Add signal loss events
      tracepoint: Add signal deliver event
      tracepoint: Move signal sending tracepoint to events/signal.h


 include/trace/events/sched.h  |   25 -------
 include/trace/events/signal.h |  137 +++++++++++++++++++++++++++++++++++++++++
 kernel/signal.c               |   27 ++++++--
 3 files changed, 157 insertions(+), 32 deletions(-)
 create mode 100644 include/trace/events/signal.h

-- 
Masami Hiramatsu

Software Engineer
Hitachi Computer Products (America), Inc.
Software Solutions Division
e-mail: mhiramat@redhat.com

[PATCH -tip v2 1/3] tracepoint: Move signal sending tracepoint to events/signal.h

[Masami Hiramatsu]

Move signal sending event to events/signal.h. This patch also renames
sched_signal_send event to signal_generate.

Changes in v2:
 - Add siginfo argument
 - Add siginfo storing macro

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
---

 include/trace/events/sched.h  |   25 ------------------
 include/trace/events/signal.h |   57 +++++++++++++++++++++++++++++++++++++++++
 kernel/signal.c               |    5 ++--
 3 files changed, 60 insertions(+), 27 deletions(-)
 create mode 100644 include/trace/events/signal.h

diff --git a/include/trace/events/sched.h b/include/trace/events/sched.h
index b50b985..b221bb3 100644
--- a/include/trace/events/sched.h
+++ b/include/trace/events/sched.h
@@ -320,31 +320,6 @@ TRACE_EVENT(sched_process_fork,
 );
 
 /*
- * Tracepoint for sending a signal:
- */
-TRACE_EVENT(sched_signal_send,
-
-	TP_PROTO(int sig, struct task_struct *p),
-
-	TP_ARGS(sig, p),
-
-	TP_STRUCT__entry(
-		__field(	int,	sig			)
-		__array(	char,	comm,	TASK_COMM_LEN	)
-		__field(	pid_t,	pid			)
-	),
-
-	TP_fast_assign(
-		memcpy(__entry->comm, p->comm, TASK_COMM_LEN);
-		__entry->pid	= p->pid;
-		__entry->sig	= sig;
-	),
-
-	TP_printk("sig=%d comm=%s pid=%d",
-		  __entry->sig, __entry->comm, __entry->pid)
-);
-
-/*
  * XXX the below sched_stat tracepoints only apply to SCHED_OTHER/BATCH/IDLE
  *     adding sched_stat support to SCHED_FIFO/RR would be welcome.
  */
diff --git a/include/trace/events/signal.h b/include/trace/events/signal.h
new file mode 100644
index 0000000..cfe9f0a
--- /dev/null
+++ b/include/trace/events/signal.h
@@ -0,0 +1,57 @@
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM signal
+
+#if !defined(_TRACE_SIGNAL_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_SIGNAL_H
+
+#include <linux/signal.h>
+#include <linux/sched.h>
+#include <linux/tracepoint.h>
+
+#define TP_STORE_SIGINFO(__entry, info)				\
+	do {							\
+		if (info == SEND_SIG_NOINFO) {			\
+			__entry->errno	= 0;			\
+			__entry->code	= SI_USER;		\
+		} else if (info == SEND_SIG_PRIV) {		\
+			__entry->errno	= 0;			\
+			__entry->code	= SI_KERNEL;		\
+		} else {					\
+			__entry->errno	= info->si_errno;	\
+			__entry->code	= info->si_code;	\
+		}						\
+	} while (0)
+
+/*
+ * Tracepoint for generating a signal:
+ */
+TRACE_EVENT(signal_generate,
+
+	TP_PROTO(int sig, struct siginfo *info, struct task_struct *p),
+
+	TP_ARGS(sig, info, p),
+
+	TP_STRUCT__entry(
+		__field(	int,	sig			)
+		__field(	int,	errno			)
+		__field(	int,	code			)
+		__array(	char,	comm,	TASK_COMM_LEN	)
+		__field(	pid_t,	pid			)
+	),
+
+	TP_fast_assign(
+		__entry->sig	= sig;
+		TP_STORE_SIGINFO(__entry, info);
+		memcpy(__entry->comm, p->comm, TASK_COMM_LEN);
+		__entry->pid	= p->pid;
+	),
+
+	TP_printk("sig=%d errno=%d code=%d comm=%s pid=%d",
+		  __entry->sig, __entry->errno, __entry->code,
+		  __entry->comm, __entry->pid)
+);
+
+#endif /* _TRACE_SIGNAL_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>
diff --git a/kernel/signal.c b/kernel/signal.c
index fe08008..54ac4c5 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -28,7 +28,8 @@
 #include <linux/freezer.h>
 #include <linux/pid_namespace.h>
 #include <linux/nsproxy.h>
-#include <trace/events/sched.h>
+#define CREATE_TRACE_POINTS
+#include <trace/events/signal.h>
 
 #include <asm/param.h>
 #include <asm/uaccess.h>
@@ -856,7 +857,7 @@ static int __send_signal(int sig, struct siginfo *info, struct task_struct *t,
 	struct sigqueue *q;
 	int override_rlimit;
 
-	trace_sched_signal_send(sig, t);
+	trace_signal_generate(sig, info, t);
 
 	assert_spin_locked(&t->sighand->siglock);
 


-- 
Masami Hiramatsu

Software Engineer
Hitachi Computer Products (America), Inc.
Software Solutions Division

e-mail: mhiramat@redhat.com

[PATCH -tip v2 3/3] tracepoint: Add signal loss events

[Masami Hiramatsu]

Add signal_overflow_fail and signal_lose_info tracepoints
for signal-lost events.

Changes in v2:
 - Use siginfo string macro

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Suggested-by: Roland McGrath <roland@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
---

 include/trace/events/signal.h |   52 +++++++++++++++++++++++++++++++++++++++++
 kernel/signal.c               |   19 +++++++++++----
 2 files changed, 66 insertions(+), 5 deletions(-)

diff --git a/include/trace/events/signal.h b/include/trace/events/signal.h
index 9a043db..f7215ed 100644
--- a/include/trace/events/signal.h
+++ b/include/trace/events/signal.h
@@ -79,6 +79,58 @@ TRACE_EVENT(signal_deliver,
 		  __entry->sig, __entry->errno, __entry->code,
 		  __entry->sa_handler, __entry->sa_flags)
 );
+
+/*
+ * Tracepoint for losing a signal by overflow:
+ */
+TRACE_EVENT(signal_overflow_fail,
+
+	TP_PROTO(int sig, int group, struct siginfo *info),
+
+	TP_ARGS(sig, group, info),
+
+	TP_STRUCT__entry(
+		__field(	int,	sig	)
+		__field(	int,	group	)
+		__field(	int,	errno	)
+		__field(	int,	code	)
+	),
+
+	TP_fast_assign(
+		__entry->sig	= sig;
+		__entry->group	= group;
+		TP_STORE_SIGINFO(__entry, info);
+	),
+
+	TP_printk("sig=%d group=%d errno=%d code=%d",
+		  __entry->sig, __entry->group, __entry->errno, __entry->code)
+);
+
+/*
+ * Tracepoint for losing a siginfo:
+ */
+TRACE_EVENT(signal_lose_info,
+
+	TP_PROTO(int sig, int group, struct siginfo *info),
+
+	TP_ARGS(sig, group, info),
+
+	TP_STRUCT__entry(
+		__field(	int,	sig	)
+		__field(	int,	group	)
+		__field(	int,	errno	)
+		__field(	int,	code	)
+	),
+
+	TP_fast_assign(
+		__entry->sig	= sig;
+		__entry->group	= group;
+		TP_STORE_SIGINFO(__entry, info);
+	),
+
+	TP_printk("sig=%d group=%d errno=%d code=%d",
+		  __entry->sig, __entry->group, __entry->errno, __entry->code)
+);
 #endif /* _TRACE_SIGNAL_H */
 
 /* This part must be outside protection */
diff --git a/kernel/signal.c b/kernel/signal.c
index d518984..6b982f2 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -919,12 +919,21 @@ static int __send_signal(int sig, struct siginfo *info, struct task_struct *t,
 			break;
 		}
 	} else if (!is_si_special(info)) {
-		if (sig >= SIGRTMIN && info->si_code != SI_USER)
-		/*
-		 * Queue overflow, abort.  We may abort if the signal was rt
-		 * and sent by user using something other than kill().
-		 */
+		if (sig >= SIGRTMIN && info->si_code != SI_USER) {
+			/*
+			 * Queue overflow, abort.  We may abort if the
+			 * signal was rt and sent by user using something
+			 * other than kill().
+			 */
+			trace_signal_overflow_fail(sig, group, info);
 			return -EAGAIN;
+		} else {
+			/*
+			 * This is a silent loss of information.  We still
+			 * send the signal, but the *info bits are lost.
+			 */
+			trace_signal_lose_info(sig, group, info);
+		}
 	}
 
 out_set:


-- 
Masami Hiramatsu

Software Engineer
Hitachi Computer Products (America), Inc.
Software Solutions Division

e-mail: mhiramat@redhat.com

[PATCH -tip v2 2/3] tracepoint: Add signal deliver event

[Masami Hiramatsu]

Add a tracepoint where a process gets a signal. This tracepoint
shows signal-number, sa-handler and sa-flag.

Changes in v2:
 - Add siginfo argument
 - Fix comment

Signed-off-by: Masami Hiramatsu <mhiramat@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 |   28 ++++++++++++++++++++++++++++
 kernel/signal.c               |    3 +++
 2 files changed, 31 insertions(+), 0 deletions(-)

diff --git a/include/trace/events/signal.h b/include/trace/events/signal.h
index cfe9f0a..9a043db 100644
--- a/include/trace/events/signal.h
+++ b/include/trace/events/signal.h
@@ -51,6 +51,34 @@ TRACE_EVENT(signal_generate,
 		  __entry->comm, __entry->pid)
 );
 
+/*
+ * Tracepoint for delivering a signal:
+ */
+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

Re: [PATCH -tip v2 0/3] tracepoint: Add signal events

[Jason Baron]

On Wed, Nov 18, 2009 at 04:16:09PM -0500, Masami Hiramatsu wrote:
> Hi,
> 
> These patches add signal related tracepoints including
> signal generation, delivery, and loss. First patch also
> moves signal-sending tracepoint from events/sched.h to
> events/signal.h.
> 
> Changes in v2
> - Add siginfo arguments
> 

hi Masami,

It would be really great if you could add docbook style comments to
your tracepoints. Here's the initial path I posted for the irq chapter:
http://lkml.indiana.edu/hypermail/linux/kernel/0904.3/02651.html

So you could add a new chapter for signals.

The current tracepoint docbook can be viewed at:

http://www.kernel.org/doc/htmldocs/tracepoint/

thanks,

-Jason

Re: [PATCH -tip v2 0/3] tracepoint: Add signal events

[Masami Hiramatsu]

Hi Jason,

Jason Baron wrote:
> On Wed, Nov 18, 2009 at 04:16:09PM -0500, Masami Hiramatsu wrote:
>> Hi,
>>
>> These patches add signal related tracepoints including
>> signal generation, delivery, and loss. First patch also
>> moves signal-sending tracepoint from events/sched.h to
>> events/signal.h.
>>
>> Changes in v2
>> - Add siginfo arguments
>>
>
> hi Masami,
>
> It would be really great if you could add docbook style comments to
> your tracepoints. Here's the initial path I posted for the irq chapter:
> http://lkml.indiana.edu/hypermail/linux/kernel/0904.3/02651.html
>
> So you could add a new chapter for signals.

Ah, that's a good suggestion. I'll add it next version.

Thank you,

>
> The current tracepoint docbook can be viewed at:
>
> http://www.kernel.org/doc/htmldocs/tracepoint/
>
> thanks,
>
> -Jason

-- 
Masami Hiramatsu

Software Engineer
Hitachi Computer Products (America), Inc.
Software Solutions Division

e-mail: mhiramat@redhat.com