[PATCH v4] signal: trace_signal_deliver when signal_group_exit

[Zhenliang Wei <weizhenliang@xxxxxxxxxx>]

In the fixes commit, removing SIGKILL from each thread signal mask
and executing "goto fatal" directly will skip the call to
"trace_signal_deliver". At this point, the delivery tracking of the SIGKILL
signal will be inaccurate.

Therefore, we need to add trace_signal_deliver before "goto fatal"
after executing sigdelset.

Note: SEND_SIG_NOINFO matches the fact that SIGKILL doesn't have any info.

Acked-by: Christian Brauner <christian@xxxxxxxxxx>
Reviewed-by: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Fixes: cf43a757fd4944 ("signal: Restore the stop PTRACE_EVENT_EXIT")
Reported-by: kbuild test robot <lkp@xxxxxxxxx>
Signed-off-by: Zhenliang Wei <weizhenliang@xxxxxxxxxx>
---
 kernel/signal.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/kernel/signal.c b/kernel/signal.c
index 227ba170298e..3edf526db7c6 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -2441,6 +2441,8 @@ bool get_signal(struct ksignal *ksig)
 	if (signal_group_exit(signal)) {
 		ksig->info.si_signo = signr = SIGKILL;
 		sigdelset(&current->pending.signal, SIGKILL);
+		trace_signal_deliver(SIGKILL, SEND_SIG_NOINFO,
+			&sighand->action[signr - 1]);
 		recalc_sigpending();
 		goto fatal;
 	}
-- 
2.14.1.windows.1