get_signal: don't abuse ksig->info.si_signo and ksig->sig

Patch series "get_signal: minor cleanups and fix".

Lets remove this clear_siginfo() right now.  It is incomplete (and thus
looks confusing) and unnecessary.  Also, PF_USER_WORKER's already don't
get a fully initialized ksig anyway.


This patch (of 3):

Cleanup and preparation for the next changes.

get_signal() uses signr or ksig->info.si_signo or ksig->sig in a chaotic
way, this looks confusing. Change it to always use signr.

Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Oleg Nesterov <[email protected]>
Cc: Christian Brauner <[email protected]>
Cc: Eric W. Biederman <[email protected]>
Cc: Peter Collingbourne <[email protected]>
Cc: Wen Yang <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

Author: oleg-nesterov

kernel/signal.c

@@ -2842,7 +2842,7 @@ bool get_signal(struct ksignal *ksig)
 				spin_lock_irq(&sighand->siglock);
 			}
 
-			if (likely(do_signal_stop(ksig->info.si_signo))) {
+			if (likely(do_signal_stop(signr))) {
 				/* It released the siglock.  */
 				goto relock;
 			}
@@ -2866,7 +2866,7 @@ bool get_signal(struct ksignal *ksig)
 
 		if (sig_kernel_coredump(signr)) {
 			if (print_fatal_signals)
-				print_fatal_signal(ksig->info.si_signo);
+				print_fatal_signal(signr);
 			proc_coredump_connector(current);
 			/*
 			 * If it was able to dump core, this kills all
@@ -2890,7 +2890,7 @@ bool get_signal(struct ksignal *ksig)
 		/*
 		 * Death signals, no core dump.
 		 */
-		do_group_exit(ksig->info.si_signo);
+		do_group_exit(signr);
 		/* NOTREACHED */
 	}
 	spin_unlock_irq(&sighand->siglock);
@@ -2900,7 +2900,7 @@ bool get_signal(struct ksignal *ksig)
 	if (!(ksig->ka.sa.sa_flags & SA_EXPOSE_TAGBITS))
 		hide_si_addr_tag_bits(ksig);
 
-	return ksig->sig > 0;
+	return signr > 0;
 }
 
 /**