From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756253AbZKTV3Y (ORCPT ); Fri, 20 Nov 2009 16:29:24 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754772AbZKTV3V (ORCPT ); Fri, 20 Nov 2009 16:29:21 -0500 Received: from mx1.redhat.com ([209.132.183.28]:58115 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756237AbZKTV3S (ORCPT ); Fri, 20 Nov 2009 16:29:18 -0500 From: Masami Hiramatsu Subject: [PATCH -tip v3 3/3] tracepoint: Add signal loss events To: Ingo Molnar , lkml Cc: systemtap , DLE , Masami Hiramatsu , Oleg Nesterov , Jason Baron , Ingo Molnar Date: Fri, 20 Nov 2009 16:31:28 -0500 Message-ID: <20091120213128.14708.47495.stgit@dhcp-100-2-132.bos.redhat.com> In-Reply-To: <20091120213108.14708.97871.stgit@dhcp-100-2-132.bos.redhat.com> References: <20091120213108.14708.97871.stgit@dhcp-100-2-132.bos.redhat.com> User-Agent: StGIT/0.14.3 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Add signal_overflow_fail and signal_lose_info tracepoints for signal-lost events. Changes in v3: - Add docbook style comments Changes in v2: - Use siginfo string macro Signed-off-by: Masami Hiramatsu Suggested-by: Roland McGrath Cc: Oleg Nesterov Cc: Jason Baron Cc: Ingo Molnar --- include/trace/events/signal.h | 68 +++++++++++++++++++++++++++++++++++++++++ kernel/signal.c | 19 ++++++++--- 2 files changed, 82 insertions(+), 5 deletions(-) diff --git a/include/trace/events/signal.h b/include/trace/events/signal.h index ddf89c9..8404d8b 100644 --- a/include/trace/events/signal.h +++ b/include/trace/events/signal.h @@ -99,6 +99,74 @@ TRACE_EVENT(signal_deliver, __entry->sig, __entry->errno, __entry->code, __entry->sa_handler, __entry->sa_flags) ); + +/** + * signal_overflow_fail - called when signal queue is overflow + * @sig: signal number + * @group: signal to process group or not (bool) + * @info: pointer to struct siginfo + * + * Kernel fails to generate 'sig' signal with 'info' siginfo, because + * siginfo queue is overflow, and the signal is dropped. + * 'group' is not 0 if the signal will be sent to a process group. + * 'sig' is always one of RT signals. + */ +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) +); + +/** + * signal_lose_info - called when siginfo is lost + * @sig: signal number + * @group: signal to process group or not (bool) + * @info: pointer to struct siginfo + * + * Kernel generates 'sig' signal but loses 'info' siginfo, because siginfo + * queue is overflow. + * 'group' is not 0 if the signal will be sent to a process group. + * 'sig' is always one of non-RT signals. + */ +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