From: Oleg Nesterov Date: Tue, 22 Nov 2011 20:13:48 +0000 (+0100) Subject: tracing: let trace_signal_generate() report more info, kill overflow_fail/lose_info X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=6c303d3ab39f0dc69546f179c424ee1124f50906;p=linux-beck.git tracing: let trace_signal_generate() report more info, kill overflow_fail/lose_info __send_signal()->trace_signal_generate() doesn't report enough info. The users want to know was the signal actually delivered or not, and they also need the shared/private info. The patch moves trace_signal_generate() at the end of __send_signal() and adds the 2 additional arguments. This also allows us to kill trace_signal_overflow_fail/lose_info, we can simply add the appropriate TRACE_SIGNAL_ "result" codes. Reported-by: Seiji Aguchi Reviewed-by: Seiji Aguchi Acked-by: Steven Rostedt Signed-off-by: Oleg Nesterov --- diff --git a/include/trace/events/signal.h b/include/trace/events/signal.h index 17df43464df0..39a8a430d90f 100644 --- a/include/trace/events/signal.h +++ b/include/trace/events/signal.h @@ -23,11 +23,23 @@ } \ } while (0) +#ifndef TRACE_HEADER_MULTI_READ +enum { + TRACE_SIGNAL_DELIVERED, + TRACE_SIGNAL_IGNORED, + TRACE_SIGNAL_ALREADY_PENDING, + TRACE_SIGNAL_OVERFLOW_FAIL, + TRACE_SIGNAL_LOSE_INFO, +}; +#endif + /** * signal_generate - called when a signal is generated * @sig: signal number * @info: pointer to struct siginfo * @task: pointer to struct task_struct + * @group: shared or private + * @result: TRACE_SIGNAL_* * * Current process sends a 'sig' signal to 'task' process with * 'info' siginfo. If 'info' is SEND_SIG_NOINFO or SEND_SIG_PRIV, @@ -37,9 +49,10 @@ */ TRACE_EVENT(signal_generate, - TP_PROTO(int sig, struct siginfo *info, struct task_struct *task), + TP_PROTO(int sig, struct siginfo *info, struct task_struct *task, + int group, int result), - TP_ARGS(sig, info, task), + TP_ARGS(sig, info, task, group, result), TP_STRUCT__entry( __field( int, sig ) @@ -47,6 +60,8 @@ TRACE_EVENT(signal_generate, __field( int, code ) __array( char, comm, TASK_COMM_LEN ) __field( pid_t, pid ) + __field( int, group ) + __field( int, result ) ), TP_fast_assign( @@ -54,11 +69,14 @@ TRACE_EVENT(signal_generate, TP_STORE_SIGINFO(__entry, info); memcpy(__entry->comm, task->comm, TASK_COMM_LEN); __entry->pid = task->pid; + __entry->group = group; + __entry->result = result; ), - TP_printk("sig=%d errno=%d code=%d comm=%s pid=%d", + TP_printk("sig=%d errno=%d code=%d comm=%s pid=%d grp=%d res=%d", __entry->sig, __entry->errno, __entry->code, - __entry->comm, __entry->pid) + __entry->comm, __entry->pid, __entry->group, + __entry->result) ); /** @@ -101,65 +119,6 @@ TRACE_EVENT(signal_deliver, __entry->sa_handler, __entry->sa_flags) ); -DECLARE_EVENT_CLASS(signal_queue_overflow, - - 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_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. - */ -DEFINE_EVENT(signal_queue_overflow, signal_overflow_fail, - - TP_PROTO(int sig, int group, struct siginfo *info), - - TP_ARGS(sig, group, info) -); - -/** - * 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. - */ -DEFINE_EVENT(signal_queue_overflow, signal_lose_info, - - TP_PROTO(int sig, int group, struct siginfo *info), - - TP_ARGS(sig, group, info) -); - #endif /* _TRACE_SIGNAL_H */ /* This part must be outside protection */ diff --git a/kernel/signal.c b/kernel/signal.c index c73c4284160e..1bd9e86fda1f 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -1054,13 +1054,13 @@ static int __send_signal(int sig, struct siginfo *info, struct task_struct *t, struct sigpending *pending; struct sigqueue *q; int override_rlimit; - - trace_signal_generate(sig, info, t); + int ret = 0, result; assert_spin_locked(&t->sighand->siglock); + result = TRACE_SIGNAL_IGNORED; if (!prepare_signal(sig, t, from_ancestor_ns)) - return 0; + goto ret; pending = group ? &t->signal->shared_pending : &t->pending; /* @@ -1068,8 +1068,11 @@ static int __send_signal(int sig, struct siginfo *info, struct task_struct *t, * exactly one non-rt signal, so that we can get more * detailed information about the cause of the signal. */ + result = TRACE_SIGNAL_ALREADY_PENDING; if (legacy_queue(pending, sig)) - return 0; + goto ret; + + result = TRACE_SIGNAL_DELIVERED; /* * fast-pathed signals for kernel-internal things like SIGSTOP * or SIGKILL. @@ -1127,14 +1130,15 @@ static int __send_signal(int sig, struct siginfo *info, struct task_struct *t, * signal was rt and sent by user using something * other than kill(). */ - trace_signal_overflow_fail(sig, group, info); - return -EAGAIN; + result = TRACE_SIGNAL_OVERFLOW_FAIL; + ret = -EAGAIN; + goto ret; } 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); + result = TRACE_SIGNAL_LOSE_INFO; } } @@ -1142,7 +1146,9 @@ out_set: signalfd_notify(t, sig); sigaddset(&pending->signal, sig); complete_signal(sig, t, group); - return 0; +ret: + trace_signal_generate(sig, info, t, group, result); + return ret; } static int send_signal(int sig, struct siginfo *info, struct task_struct *t,