lkml.org 
[lkml]   [2007]   [Sep]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH] [36/50] x86: Use raw locks during oopses
Date

Don't want any lockdep or other fragile machinery to run during oopses.
Use raw spinlocks directly for oops locking.
Also disables irq flag tracing there.

Signed-off-by: Andi Kleen <ak@suse.de>

---
arch/i386/kernel/traps.c | 12 +++++++-----
arch/x86_64/kernel/traps.c | 17 ++++++++---------
2 files changed, 15 insertions(+), 14 deletions(-)

Index: linux/arch/i386/kernel/traps.c
===================================================================
--- linux.orig/arch/i386/kernel/traps.c
+++ linux/arch/i386/kernel/traps.c
@@ -447,11 +447,11 @@ void ler_enable(void) {
void die(const char * str, struct pt_regs * regs, long err)
{
static struct {
- spinlock_t lock;
+ raw_spinlock_t lock;
u32 lock_owner;
int lock_owner_depth;
} die = {
- .lock = __SPIN_LOCK_UNLOCKED(die.lock),
+ .lock = __RAW_SPIN_LOCK_UNLOCKED,
.lock_owner = -1,
.lock_owner_depth = 0
};
@@ -462,13 +462,14 @@ void die(const char * str, struct pt_reg

if (die.lock_owner != raw_smp_processor_id()) {
console_verbose();
- spin_lock_irqsave(&die.lock, flags);
+ __raw_spin_lock(&die.lock);
+ raw_local_save_flags(flags);
die.lock_owner = smp_processor_id();
die.lock_owner_depth = 0;
bust_spinlocks(1);
}
else
- local_save_flags(flags);
+ raw_local_save_flags(flags);

if (++die.lock_owner_depth < 3) {
unsigned long esp;
@@ -511,7 +512,8 @@ void die(const char * str, struct pt_reg
bust_spinlocks(0);
die.lock_owner = -1;
add_taint(TAINT_DIE);
- spin_unlock_irqrestore(&die.lock, flags);
+ __raw_spin_unlock(&die.lock);
+ raw_local_irq_restore(flags);

if (!regs)
return;
Index: linux/arch/x86_64/kernel/traps.c
===================================================================
--- linux.orig/arch/x86_64/kernel/traps.c
+++ linux/arch/x86_64/kernel/traps.c
@@ -556,7 +556,7 @@ void ler_enable(void) {
}
}

-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;

@@ -568,13 +568,13 @@ 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;
@@ -588,12 +588,11 @@ 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 (!regs) {
oops_exit();
return;
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
\
 
 \ /
  Last update: 2007-09-22 00:49    [W:0.309 / U:0.792 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site