1 files changed, 54 insertions, 22 deletions

diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index 17724fb2067..f7862224fe8 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -90,21 +90,11 @@ EXPORT_SYMBOL(unregister_die_notifier);
  * Trap & Exception support
  */
 
-static DEFINE_SPINLOCK(die_lock);
-
-int die(const char *str, struct pt_regs *regs, long err)
-{
-	static int die_counter;
-
-	if (debugger(regs))
-		return 1;
-
-	console_verbose();
-	spin_lock_irq(&die_lock);
-	bust_spinlocks(1);
 #ifdef CONFIG_PMAC_BACKLIGHT
+static void pmac_backlight_unblank(void)
+{
 	mutex_lock(&pmac_backlight_mutex);
-	if (machine_is(powermac) && pmac_backlight) {
+	if (pmac_backlight) {
 		struct backlight_properties *props;
 
 		props = &pmac_backlight->props;
@@ -113,26 +103,67 @@ int die(const char *str, struct pt_regs *regs, long err)
 		backlight_update_status(pmac_backlight);
 	}
 	mutex_unlock(&pmac_backlight_mutex);
+}
+#else
+static inline void pmac_backlight_unblank(void) { }
 #endif
-	printk("Oops: %s, sig: %ld [#%d]\n", str, err, ++die_counter);
+
+int die(const char *str, struct pt_regs *regs, long err)
+{
+	static struct {
+		spinlock_t lock;
+		u32 lock_owner;
+		int lock_owner_depth;
+	} die = {
+		.lock =			__SPIN_LOCK_UNLOCKED(die.lock),
+		.lock_owner =		-1,
+		.lock_owner_depth =	0
+	};
+	static int die_counter;
+	unsigned long flags;
+
+	if (debugger(regs))
+		return 1;
+
+	oops_enter();
+
+	if (die.lock_owner != raw_smp_processor_id()) {
+		console_verbose();
+		spin_lock_irqsave(&die.lock, flags);
+		die.lock_owner = smp_processor_id();
+		die.lock_owner_depth = 0;
+		bust_spinlocks(1);
+		if (machine_is(powermac))
+			pmac_backlight_unblank();
+	} else {
+		local_save_flags(flags);
+	}
+
+	if (++die.lock_owner_depth < 3) {
+		printk("Oops: %s, sig: %ld [#%d]\n", str, err, ++die_counter);
 #ifdef CONFIG_PREEMPT
-	printk("PREEMPT ");
+		printk("PREEMPT ");
 #endif
 #ifdef CONFIG_SMP
-	printk("SMP NR_CPUS=%d ", NR_CPUS);
+		printk("SMP NR_CPUS=%d ", NR_CPUS);
 #endif
 #ifdef CONFIG_DEBUG_PAGEALLOC
-	printk("DEBUG_PAGEALLOC ");
+		printk("DEBUG_PAGEALLOC ");
 #endif
 #ifdef CONFIG_NUMA
-	printk("NUMA ");
+		printk("NUMA ");
 #endif
-	printk("%s\n", ppc_md.name ? "" : ppc_md.name);
+		printk("%s\n", ppc_md.name ? ppc_md.name : "");
+
+		print_modules();
+		show_regs(regs);
+	} else {
+		printk("Recursive die() failure, output suppressed\n");
+	}
 
-	print_modules();
-	show_regs(regs);
 	bust_spinlocks(0);
-	spin_unlock_irq(&die_lock);
+	die.lock_owner = -1;
+	spin_unlock_irqrestore(&die.lock, flags);
 
 	if (kexec_should_crash(current) ||
 		kexec_sr_activated(smp_processor_id()))
@@ -145,6 +176,7 @@ int die(const char *str, struct pt_regs *regs, long err)
 	if (panic_on_oops)
 		panic("Fatal exception");
 
+	oops_exit();
 	do_exit(err);
 
 	return 0;