Linux-libre 4.7.1-gnupck-4.7.1-gnu

1 files changed, 24 insertions, 15 deletions

diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
index e22849a90..b1166d1e5 100644
--- a/arch/arm64/mm/fault.c
+++ b/arch/arm64/mm/fault.c
@@ -262,10 +262,6 @@ static int __kprobes do_page_fault(unsigned long addr, unsigned int esr,
 	tsk = current;
 	mm  = tsk->mm;
 
-	/* Enable interrupts if they were enabled in the parent context. */
-	if (interrupts_enabled(regs))
-		local_irq_enable();
-
 	/*
 	 * If we're in an interrupt or have no user context, we must not take
 	 * the fault.
@@ -446,7 +442,7 @@ static int do_bad(unsigned long addr, unsigned int esr, struct pt_regs *regs)
 	return 1;
 }
 
-static struct fault_info {
+static const struct fault_info {
 	int	(*fn)(unsigned long addr, unsigned int esr, struct pt_regs *regs);
 	int	sig;
 	int	code;
@@ -606,20 +602,33 @@ asmlinkage int __exception do_debug_exception(unsigned long addr,
 {
 	const struct fault_info *inf = debug_fault_info + DBG_ESR_EVT(esr);
 	struct siginfo info;
+	int rv;
 
-	if (!inf->fn(addr, esr, regs))
-		return 1;
+	/*
+	 * Tell lockdep we disabled irqs in entry.S. Do nothing if they were
+	 * already disabled to preserve the last enabled/disabled addresses.
+	 */
+	if (interrupts_enabled(regs))
+		trace_hardirqs_off();
 
-	pr_alert("Unhandled debug exception: %s (0x%08x) at 0x%016lx\n",
-		 inf->name, esr, addr);
+	if (!inf->fn(addr, esr, regs)) {
+		rv = 1;
+	} else {
+		pr_alert("Unhandled debug exception: %s (0x%08x) at 0x%016lx\n",
+			 inf->name, esr, addr);
+
+		info.si_signo = inf->sig;
+		info.si_errno = 0;
+		info.si_code  = inf->code;
+		info.si_addr  = (void __user *)addr;
+		arm64_notify_die("", regs, &info, 0);
+		rv = 0;
+	}
 
-	info.si_signo = inf->sig;
-	info.si_errno = 0;
-	info.si_code  = inf->code;
-	info.si_addr  = (void __user *)addr;
-	arm64_notify_die("", regs, &info, 0);
+	if (interrupts_enabled(regs))
+		trace_hardirqs_on();
 
-	return 0;
+	return rv;
 }
 
 #ifdef CONFIG_ARM64_PAN