From e43d674f44dc885a2476cab3537e639d9eaa31a9 Mon Sep 17 00:00:00 2001
From: Jan Beulich <jbeulich@novell.com>
Date: Fri, 6 Jan 2006 00:11:48 -0800
Subject: [PATCH] [PATCH] i386: don't blindly enable interrupts in die()
Rather than blindly re-enabling interrupts in die(), save their state
upon entry and then restore that state.
If the kernel is in really bad condition and faults with interrupts disabled,
re-enabling them in die() may cause even more trouble, implying more chances
of data corruption.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---
arch/i386/kernel/traps.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/arch/i386/kernel/traps.c b/arch/i386/kernel/traps.c
index ab0e9430f775c..bb36a989db778 100644
--- a/arch/i386/kernel/traps.c
+++ b/arch/i386/kernel/traps.c
@@ -306,14 +306,17 @@ void die(const char * str, struct pt_regs * regs, long err)
.lock_owner_depth = 0
};
static int die_counter;
+ unsigned long flags;
if (die.lock_owner != raw_smp_processor_id()) {
console_verbose();
- spin_lock_irq(&die.lock);
+ spin_lock_irqsave(&die.lock, flags);
die.lock_owner = smp_processor_id();
die.lock_owner_depth = 0;
bust_spinlocks(1);
}
+ else
+ local_save_flags(flags);
if (++die.lock_owner_depth < 3) {
int nl = 0;
@@ -340,7 +343,7 @@ void die(const char * str, struct pt_regs * regs, long err)
bust_spinlocks(0);
die.lock_owner = -1;
- spin_unlock_irq(&die.lock);
+ spin_unlock_irqrestore(&die.lock, flags);
if (kexec_should_crash(current))
crash_kexec(regs);
--
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