allow recursive die() on i386

[Jeff Moyer <jmoyer@redhat.com>]

Hello,

This patch allows for a recursive die() on i386.  This closely resembles
what is done on x86_64, fwiw.

-Jeff

--- linux-2.6.7/arch/i386/kernel/traps.c.orig	2004-07-28 08:08:21.000000000 -0400
+++ linux-2.6.7/arch/i386/kernel/traps.c	2004-07-28 08:10:54.000000000 -0400
@@ -294,6 +294,7 @@ bug:
 }
 
 spinlock_t die_lock = SPIN_LOCK_UNLOCKED;
+static int die_owner = -1;
 
 void die(const char * str, struct pt_regs * regs, long err)
 {
@@ -301,7 +302,13 @@ void die(const char * str, struct pt_reg
 	int nl = 0;
 
 	console_verbose();
-	spin_lock_irq(&die_lock);
+	local_irq_disable();
+	if (!spin_trylock(&die_lock)) {
+		if (smp_processor_id() != die_owner)
+			spin_lock(&die_lock);
+		/* allow recursive die to fall through */
+	}
+	die_owner = smp_processor_id();
 	bust_spinlocks(1);
 	handle_BUG(regs);
 	printk(KERN_ALERT "%s: %04lx [#%d]\n", str, err & 0xffff, ++die_counter);
@@ -321,6 +328,7 @@ void die(const char * str, struct pt_reg
 		printk("\n");
 	show_registers(regs);
 	bust_spinlocks(0);
+	die_owner = -1;
 	spin_unlock_irq(&die_lock);
 	if (in_interrupt())
 		panic("Fatal exception in interrupt");