When the kernel is oopsing no realtime guarantees are needed anymore and sleeping
here is unsafe; e.g. in case the crash site had interrupts disabled.
- Convert die_lock to a raw spinlock
- Really disable interrupts
Signed-off-by: Andi Kleen <ak@xxxxxxx>
Index: linux-2.6.23-rc4-rt1/arch/x86_64/kernel/traps.c
===================================================================
--- linux-2.6.23-rc4-rt1.orig/arch/x86_64/kernel/traps.c
+++ linux-2.6.23-rc4-rt1/arch/x86_64/kernel/traps.c
@@ -467,7 +467,7 @@ void out_of_line_bug(void)
EXPORT_SYMBOL(out_of_line_bug);
#endif
-static DEFINE_SPINLOCK(die_lock);
+static __raw_spinlock_t die_lock = __RAW_SPIN_LOCK_UNLOCKED;
static int die_owner = -1;
static unsigned int die_nest_count;
@@ -479,13 +479,13 @@ unsigned __kprobes long oops_begin(void)
oops_enter();
/* racy, but better than risking deadlock. */
- local_irq_save(flags);
+ raw_local_irq_save(flags);
cpu = smp_processor_id();
- if (!spin_trylock(&die_lock)) {
+ if (!__raw_spin_trylock(&die_lock)) {
if (cpu == die_owner)
/* nested oops. should stop eventually */;
else
- spin_lock(&die_lock);
+ __raw_spin_lock(&die_lock);
}
die_nest_count++;
die_owner = cpu;
@@ -499,12 +499,10 @@ void __kprobes oops_end(unsigned long fl
die_owner = -1;
bust_spinlocks(0);
die_nest_count--;
- if (die_nest_count)
- /* We still own the lock */
- local_irq_restore(flags);
- else
+ if (!die_nest_count)
/* Nest count reaches zero, release the lock. */
- spin_unlock_irqrestore(&die_lock, flags);
+ __raw_spin_unlock(&die_lock);
+ raw_local_irq_restore(flags);
if (panic_on_oops)
panic("Fatal exception");
oops_exit();
-
To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
