[PATCH 2/2] kernel/signal.c: explicitly initialize si_code and use ksig->info uniformly

[wenyang . linux]

From: Wen Yang <wenyang.linux@xxxxxxxxxxx>

By explicitly initializing ksig->info.si_code and uniformly using ksig->info,
get_signal() function could be slightly optimized, as folowes:

	clear_siginfo(&ksig->info);
	ksig->info.si_signo = signr = SIGKILL;          --> missed si_code
	sigdelset(&current->pending.signal, SIGKILL);
	trace_signal_deliver(SIGKILL, SEND_SIG_NOINFO,  --> unnecessary SEND_SIG_NOINFO
 			&sighand->action[SIGKILL - 1]);
			recalc_sigpending();
	goto fatal;
..

        fatal:
..
                  if (sig_kernel_coredump(signr)) {
..
                          do_coredump(&ksig->info);    --> contains si_code
                }

No functional change intended.

Signed-off-by: Wen Yang <wenyang.linux@xxxxxxxxxxx>
Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Christian Brauner <brauner@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
Cc: Luis Chamberlain <mcgrof@xxxxxxxxxx>
Cc: Mike Christie <michael.christie@xxxxxxxxxx>
Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Cc: Vincent Whitchurch <vincent.whitchurch@xxxxxxxx>
Cc: Ard Biesheuvel <ardb@xxxxxxxxxx>
Cc: linux-kernel@xxxxxxxxxxxxxxx
---
 kernel/signal.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/kernel/signal.c b/kernel/signal.c
index 9b40109f0c56..8cab55bbec2f 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -2732,8 +2732,9 @@ bool get_signal(struct ksignal *ksig)
 		     signal->group_exec_task) {
 			clear_siginfo(&ksig->info);
 			ksig->info.si_signo = signr = SIGKILL;
+			ksig->info.si_code = SI_USER;
 			sigdelset(&current->pending.signal, SIGKILL);
-			trace_signal_deliver(SIGKILL, SEND_SIG_NOINFO,
+			trace_signal_deliver(SIGKILL, &ksig->info,
 				&sighand->action[SIGKILL - 1]);
 			recalc_sigpending();
 			goto fatal;
-- 
2.25.1