[PATCH v3] signal: trace_signal_deliver when signal_group_exit

From: Zhenliang Wei
Date: Mon Apr 22 2019 - 11:00:52 EST

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: The action[SIGKILL] must be SIG_DFL, and SEND_SIG_NOINFO matches
the fact that SIGKILL doesn't have any info.

Acked-by: Christian Brauner <christian@xxxxxxxxxx>
Fixes: cf43a757fd4944 ("signal: Restore the stop PTRACE_EVENT_EXIT")
Signed-off-by: Zhenliang Wei <weizhenliang@xxxxxxxxxx>
kernel/signal.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/kernel/signal.c b/kernel/signal.c
index 227ba170298e..0f69ada376ef 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -2441,6 +2441,7 @@ 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, SIG_DFL);
goto fatal;