arm64: Do not report user faults for handled signals

Currently user faults (page, undefined instruction) are always reported
even though the user may have a signal handler for them. This patch adds
unhandled_signal() check together with printk_ratelimit() for these
cases.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

arch/arm64/kernel/traps.c

@@ -267,7 +267,8 @@ asmlinkage void __exception do_undefinstr(struct pt_regs *regs)
 		return;
 #endif
 
-	if (show_unhandled_signals) {
+	if (show_unhandled_signals && unhandled_signal(current, SIGILL) &&
+	    printk_ratelimit()) {
 		pr_info("%s[%d]: undefined instruction: pc=%p\n",
 			current->comm, task_pid_nr(current), pc);
 		dump_instr(KERN_INFO, regs);
@@ -294,7 +295,7 @@ asmlinkage long do_ni_syscall(struct pt_regs *regs)
 	}
 #endif
 
-	if (show_unhandled_signals) {
+	if (show_unhandled_signals && printk_ratelimit()) {
 		pr_info("%s[%d]: syscall %d\n", current->comm,
 			task_pid_nr(current), (int)regs->syscallno);
 		dump_instr("", regs);

arch/arm64/mm/fault.c

@@ -113,7 +113,8 @@ static void __do_user_fault(struct task_struct *tsk, unsigned long addr,
 {
 	struct siginfo si;
 
-	if (show_unhandled_signals) {
+	if (show_unhandled_signals && unhandled_signal(tsk, sig) &&
+	    printk_ratelimit()) {
 		pr_info("%s[%d]: unhandled %s (%d) at 0x%08lx, esr 0x%03x\n",
 			tsk->comm, task_pid_nr(tsk), fault_name(esr), sig,
 			addr, esr);