Add SIGURG to list of ignore-by-default signals

arch/i386/kernel/signal.c

@@ -657,7 +657,7 @@ int do_signal(struct pt_regs *regs, sigset_t *oldset)
 				continue;
 
 			switch (signr) {
-			case SIGCONT: case SIGCHLD: case SIGWINCH:
+			case SIGCONT: case SIGCHLD: case SIGWINCH: case SIGURG:
 				continue;
 
 			case SIGTSTP: case SIGTTIN: case SIGTTOU:

kernel/signal.c

@@ -1110,7 +1110,8 @@ do_sigaction(int sig, const struct k_sigaction *act, struct k_sigaction *oact)
 		    || (k->sa.sa_handler == SIG_DFL
 			&& (sig == SIGCONT ||
 			    sig == SIGCHLD ||
-			    sig == SIGWINCH))) {
+			    sig == SIGWINCH ||
+			    sig == SIGURG))) {
 			spin_lock_irq(&current->sigmask_lock);
 			if (rm_sig_from_queue(sig, current))
 				recalc_sigpending();