Revision 7695fb04aca62e2d8a7ca6ede50f6211e1d71e53 authored by Darren Salt on 07 February 2009, 06:02:07 UTC, committed by Len Brown on 07 February 2009, 06:02:07 UTC
I got the following oops while changing the backlight brightness during startup. When it happens, it prevents use of the hotkeys, Fn-Fx, and the lid button. It's a clear use-before-init, as I verified by testing with an appropriately-placed "else printk". BUG: unable to handle kernel NULL pointer dereference at 00000000 *pde = 00000000 Oops: 0002 [#1] PREEMPT SMP Pid: 160, comm: kacpi_notify Not tainted (2.6.28.1-eee901 #4) 901 EIP: 0060:[<c0264e68>] [<c0264e68>] eeepc_hotk_notify+26/da EFLAGS: 00010246 CPU: 1 Using defaults from ksymoops -t elf32-i386 -a i386 EAX: 00000009 EBX: 00000000 ECX: 00000009 EDX: f70dbf64 ESI: 00000029 EDI: f7335188 EBP: c02112c9 ESP: f70dbf80 DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068 f70731e0 f73acd50 c02164ac f7335180 f70aa040 c02112e6 f733518c c012b62f f70aa044 f70aa040 c012bdba f70aa04c 00000000 c012be6e 00000000 f70bdf80 c012e198 f70dbfc4 f70dbfc4 f70aa040 c012bdba 00000000 c012e0c9 c012e091 Call Trace: [<c02164ac>] ? acpi_ev_notify_dispatch+4c/55 [<c02112e6>] ? acpi_os_execute_deferred+1d/25 [<c012b62f>] ? run_workqueue+71/f1 [<c012bdba>] ? worker_thread+0/bf [<c012be6e>] ? worker_thread+b4/bf [<c012e198>] ? autoremove_wake_function+0/2b [<c012bdba>] ? worker_thread+0/bf [<c012e0c9>] ? kthread+38/5f [<c012e091>] ? kthread+0/5f [<c0103abf>] ? kernel_thread_helper+7/10 Code: 00 00 00 00 c3 83 3d 60 5c 50 c0 00 56 89 d6 53 0f 84 c4 00 00 00 8d 42 e0 83 f8 0f 77 0f 8b 1d 68 5c 50 c0 89 d8 e8 a9 fa ff ff <89> 03 8b 1d 60 5c 50 c0 89 f2 83 e2 7f 0f b7 4c 53 10 8d 41 01 Signed-off-by: Darren Salt <linux@youmustbejoking.demon.co.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Len Brown <len.brown@intel.com>
1 parent 386e4a8
spinlock.c
/*
* Copyright (2004) Linus Torvalds
*
* Author: Zwane Mwaikambo <zwane@fsmlabs.com>
*
* Copyright (2004, 2005) Ingo Molnar
*
* This file contains the spinlock/rwlock implementations for the
* SMP and the DEBUG_SPINLOCK cases. (UP-nondebug inlines them)
*
* Note that some architectures have special knowledge about the
* stack frames of these functions in their profile_pc. If you
* change anything significant here that could change the stack
* frame contact the architecture maintainers.
*/
#include <linux/linkage.h>
#include <linux/preempt.h>
#include <linux/spinlock.h>
#include <linux/interrupt.h>
#include <linux/debug_locks.h>
#include <linux/module.h>
int __lockfunc _spin_trylock(spinlock_t *lock)
{
preempt_disable();
if (_raw_spin_trylock(lock)) {
spin_acquire(&lock->dep_map, 0, 1, _RET_IP_);
return 1;
}
preempt_enable();
return 0;
}
EXPORT_SYMBOL(_spin_trylock);
int __lockfunc _read_trylock(rwlock_t *lock)
{
preempt_disable();
if (_raw_read_trylock(lock)) {
rwlock_acquire_read(&lock->dep_map, 0, 1, _RET_IP_);
return 1;
}
preempt_enable();
return 0;
}
EXPORT_SYMBOL(_read_trylock);
int __lockfunc _write_trylock(rwlock_t *lock)
{
preempt_disable();
if (_raw_write_trylock(lock)) {
rwlock_acquire(&lock->dep_map, 0, 1, _RET_IP_);
return 1;
}
preempt_enable();
return 0;
}
EXPORT_SYMBOL(_write_trylock);
/*
* If lockdep is enabled then we use the non-preemption spin-ops
* even on CONFIG_PREEMPT, because lockdep assumes that interrupts are
* not re-enabled during lock-acquire (which the preempt-spin-ops do):
*/
#if !defined(CONFIG_GENERIC_LOCKBREAK) || defined(CONFIG_DEBUG_LOCK_ALLOC)
void __lockfunc _read_lock(rwlock_t *lock)
{
preempt_disable();
rwlock_acquire_read(&lock->dep_map, 0, 0, _RET_IP_);
LOCK_CONTENDED(lock, _raw_read_trylock, _raw_read_lock);
}
EXPORT_SYMBOL(_read_lock);
unsigned long __lockfunc _spin_lock_irqsave(spinlock_t *lock)
{
unsigned long flags;
local_irq_save(flags);
preempt_disable();
spin_acquire(&lock->dep_map, 0, 0, _RET_IP_);
/*
* On lockdep we dont want the hand-coded irq-enable of
* _raw_spin_lock_flags() code, because lockdep assumes
* that interrupts are not re-enabled during lock-acquire:
*/
#ifdef CONFIG_LOCKDEP
LOCK_CONTENDED(lock, _raw_spin_trylock, _raw_spin_lock);
#else
_raw_spin_lock_flags(lock, &flags);
#endif
return flags;
}
EXPORT_SYMBOL(_spin_lock_irqsave);
void __lockfunc _spin_lock_irq(spinlock_t *lock)
{
local_irq_disable();
preempt_disable();
spin_acquire(&lock->dep_map, 0, 0, _RET_IP_);
LOCK_CONTENDED(lock, _raw_spin_trylock, _raw_spin_lock);
}
EXPORT_SYMBOL(_spin_lock_irq);
void __lockfunc _spin_lock_bh(spinlock_t *lock)
{
local_bh_disable();
preempt_disable();
spin_acquire(&lock->dep_map, 0, 0, _RET_IP_);
LOCK_CONTENDED(lock, _raw_spin_trylock, _raw_spin_lock);
}
EXPORT_SYMBOL(_spin_lock_bh);
unsigned long __lockfunc _read_lock_irqsave(rwlock_t *lock)
{
unsigned long flags;
local_irq_save(flags);
preempt_disable();
rwlock_acquire_read(&lock->dep_map, 0, 0, _RET_IP_);
LOCK_CONTENDED(lock, _raw_read_trylock, _raw_read_lock);
return flags;
}
EXPORT_SYMBOL(_read_lock_irqsave);
void __lockfunc _read_lock_irq(rwlock_t *lock)
{
local_irq_disable();
preempt_disable();
rwlock_acquire_read(&lock->dep_map, 0, 0, _RET_IP_);
LOCK_CONTENDED(lock, _raw_read_trylock, _raw_read_lock);
}
EXPORT_SYMBOL(_read_lock_irq);
void __lockfunc _read_lock_bh(rwlock_t *lock)
{
local_bh_disable();
preempt_disable();
rwlock_acquire_read(&lock->dep_map, 0, 0, _RET_IP_);
LOCK_CONTENDED(lock, _raw_read_trylock, _raw_read_lock);
}
EXPORT_SYMBOL(_read_lock_bh);
unsigned long __lockfunc _write_lock_irqsave(rwlock_t *lock)
{
unsigned long flags;
local_irq_save(flags);
preempt_disable();
rwlock_acquire(&lock->dep_map, 0, 0, _RET_IP_);
LOCK_CONTENDED(lock, _raw_write_trylock, _raw_write_lock);
return flags;
}
EXPORT_SYMBOL(_write_lock_irqsave);
void __lockfunc _write_lock_irq(rwlock_t *lock)
{
local_irq_disable();
preempt_disable();
rwlock_acquire(&lock->dep_map, 0, 0, _RET_IP_);
LOCK_CONTENDED(lock, _raw_write_trylock, _raw_write_lock);
}
EXPORT_SYMBOL(_write_lock_irq);
void __lockfunc _write_lock_bh(rwlock_t *lock)
{
local_bh_disable();
preempt_disable();
rwlock_acquire(&lock->dep_map, 0, 0, _RET_IP_);
LOCK_CONTENDED(lock, _raw_write_trylock, _raw_write_lock);
}
EXPORT_SYMBOL(_write_lock_bh);
void __lockfunc _spin_lock(spinlock_t *lock)
{
preempt_disable();
spin_acquire(&lock->dep_map, 0, 0, _RET_IP_);
LOCK_CONTENDED(lock, _raw_spin_trylock, _raw_spin_lock);
}
EXPORT_SYMBOL(_spin_lock);
void __lockfunc _write_lock(rwlock_t *lock)
{
preempt_disable();
rwlock_acquire(&lock->dep_map, 0, 0, _RET_IP_);
LOCK_CONTENDED(lock, _raw_write_trylock, _raw_write_lock);
}
EXPORT_SYMBOL(_write_lock);
#else /* CONFIG_PREEMPT: */
/*
* This could be a long-held lock. We both prepare to spin for a long
* time (making _this_ CPU preemptable if possible), and we also signal
* towards that other CPU that it should break the lock ASAP.
*
* (We do this in a function because inlining it would be excessive.)
*/
#define BUILD_LOCK_OPS(op, locktype) \
void __lockfunc _##op##_lock(locktype##_t *lock) \
{ \
for (;;) { \
preempt_disable(); \
if (likely(_raw_##op##_trylock(lock))) \
break; \
preempt_enable(); \
\
if (!(lock)->break_lock) \
(lock)->break_lock = 1; \
while (!op##_can_lock(lock) && (lock)->break_lock) \
_raw_##op##_relax(&lock->raw_lock); \
} \
(lock)->break_lock = 0; \
} \
\
EXPORT_SYMBOL(_##op##_lock); \
\
unsigned long __lockfunc _##op##_lock_irqsave(locktype##_t *lock) \
{ \
unsigned long flags; \
\
for (;;) { \
preempt_disable(); \
local_irq_save(flags); \
if (likely(_raw_##op##_trylock(lock))) \
break; \
local_irq_restore(flags); \
preempt_enable(); \
\
if (!(lock)->break_lock) \
(lock)->break_lock = 1; \
while (!op##_can_lock(lock) && (lock)->break_lock) \
_raw_##op##_relax(&lock->raw_lock); \
} \
(lock)->break_lock = 0; \
return flags; \
} \
\
EXPORT_SYMBOL(_##op##_lock_irqsave); \
\
void __lockfunc _##op##_lock_irq(locktype##_t *lock) \
{ \
_##op##_lock_irqsave(lock); \
} \
\
EXPORT_SYMBOL(_##op##_lock_irq); \
\
void __lockfunc _##op##_lock_bh(locktype##_t *lock) \
{ \
unsigned long flags; \
\
/* */ \
/* Careful: we must exclude softirqs too, hence the */ \
/* irq-disabling. We use the generic preemption-aware */ \
/* function: */ \
/**/ \
flags = _##op##_lock_irqsave(lock); \
local_bh_disable(); \
local_irq_restore(flags); \
} \
\
EXPORT_SYMBOL(_##op##_lock_bh)
/*
* Build preemption-friendly versions of the following
* lock-spinning functions:
*
* _[spin|read|write]_lock()
* _[spin|read|write]_lock_irq()
* _[spin|read|write]_lock_irqsave()
* _[spin|read|write]_lock_bh()
*/
BUILD_LOCK_OPS(spin, spinlock);
BUILD_LOCK_OPS(read, rwlock);
BUILD_LOCK_OPS(write, rwlock);
#endif /* CONFIG_PREEMPT */
#ifdef CONFIG_DEBUG_LOCK_ALLOC
void __lockfunc _spin_lock_nested(spinlock_t *lock, int subclass)
{
preempt_disable();
spin_acquire(&lock->dep_map, subclass, 0, _RET_IP_);
LOCK_CONTENDED(lock, _raw_spin_trylock, _raw_spin_lock);
}
EXPORT_SYMBOL(_spin_lock_nested);
unsigned long __lockfunc _spin_lock_irqsave_nested(spinlock_t *lock, int subclass)
{
unsigned long flags;
local_irq_save(flags);
preempt_disable();
spin_acquire(&lock->dep_map, subclass, 0, _RET_IP_);
/*
* On lockdep we dont want the hand-coded irq-enable of
* _raw_spin_lock_flags() code, because lockdep assumes
* that interrupts are not re-enabled during lock-acquire:
*/
#ifdef CONFIG_LOCKDEP
LOCK_CONTENDED(lock, _raw_spin_trylock, _raw_spin_lock);
#else
_raw_spin_lock_flags(lock, &flags);
#endif
return flags;
}
EXPORT_SYMBOL(_spin_lock_irqsave_nested);
void __lockfunc _spin_lock_nest_lock(spinlock_t *lock,
struct lockdep_map *nest_lock)
{
preempt_disable();
spin_acquire_nest(&lock->dep_map, 0, 0, nest_lock, _RET_IP_);
LOCK_CONTENDED(lock, _raw_spin_trylock, _raw_spin_lock);
}
EXPORT_SYMBOL(_spin_lock_nest_lock);
#endif
void __lockfunc _spin_unlock(spinlock_t *lock)
{
spin_release(&lock->dep_map, 1, _RET_IP_);
_raw_spin_unlock(lock);
preempt_enable();
}
EXPORT_SYMBOL(_spin_unlock);
void __lockfunc _write_unlock(rwlock_t *lock)
{
rwlock_release(&lock->dep_map, 1, _RET_IP_);
_raw_write_unlock(lock);
preempt_enable();
}
EXPORT_SYMBOL(_write_unlock);
void __lockfunc _read_unlock(rwlock_t *lock)
{
rwlock_release(&lock->dep_map, 1, _RET_IP_);
_raw_read_unlock(lock);
preempt_enable();
}
EXPORT_SYMBOL(_read_unlock);
void __lockfunc _spin_unlock_irqrestore(spinlock_t *lock, unsigned long flags)
{
spin_release(&lock->dep_map, 1, _RET_IP_);
_raw_spin_unlock(lock);
local_irq_restore(flags);
preempt_enable();
}
EXPORT_SYMBOL(_spin_unlock_irqrestore);
void __lockfunc _spin_unlock_irq(spinlock_t *lock)
{
spin_release(&lock->dep_map, 1, _RET_IP_);
_raw_spin_unlock(lock);
local_irq_enable();
preempt_enable();
}
EXPORT_SYMBOL(_spin_unlock_irq);
void __lockfunc _spin_unlock_bh(spinlock_t *lock)
{
spin_release(&lock->dep_map, 1, _RET_IP_);
_raw_spin_unlock(lock);
preempt_enable_no_resched();
local_bh_enable_ip((unsigned long)__builtin_return_address(0));
}
EXPORT_SYMBOL(_spin_unlock_bh);
void __lockfunc _read_unlock_irqrestore(rwlock_t *lock, unsigned long flags)
{
rwlock_release(&lock->dep_map, 1, _RET_IP_);
_raw_read_unlock(lock);
local_irq_restore(flags);
preempt_enable();
}
EXPORT_SYMBOL(_read_unlock_irqrestore);
void __lockfunc _read_unlock_irq(rwlock_t *lock)
{
rwlock_release(&lock->dep_map, 1, _RET_IP_);
_raw_read_unlock(lock);
local_irq_enable();
preempt_enable();
}
EXPORT_SYMBOL(_read_unlock_irq);
void __lockfunc _read_unlock_bh(rwlock_t *lock)
{
rwlock_release(&lock->dep_map, 1, _RET_IP_);
_raw_read_unlock(lock);
preempt_enable_no_resched();
local_bh_enable_ip((unsigned long)__builtin_return_address(0));
}
EXPORT_SYMBOL(_read_unlock_bh);
void __lockfunc _write_unlock_irqrestore(rwlock_t *lock, unsigned long flags)
{
rwlock_release(&lock->dep_map, 1, _RET_IP_);
_raw_write_unlock(lock);
local_irq_restore(flags);
preempt_enable();
}
EXPORT_SYMBOL(_write_unlock_irqrestore);
void __lockfunc _write_unlock_irq(rwlock_t *lock)
{
rwlock_release(&lock->dep_map, 1, _RET_IP_);
_raw_write_unlock(lock);
local_irq_enable();
preempt_enable();
}
EXPORT_SYMBOL(_write_unlock_irq);
void __lockfunc _write_unlock_bh(rwlock_t *lock)
{
rwlock_release(&lock->dep_map, 1, _RET_IP_);
_raw_write_unlock(lock);
preempt_enable_no_resched();
local_bh_enable_ip((unsigned long)__builtin_return_address(0));
}
EXPORT_SYMBOL(_write_unlock_bh);
int __lockfunc _spin_trylock_bh(spinlock_t *lock)
{
local_bh_disable();
preempt_disable();
if (_raw_spin_trylock(lock)) {
spin_acquire(&lock->dep_map, 0, 1, _RET_IP_);
return 1;
}
preempt_enable_no_resched();
local_bh_enable_ip((unsigned long)__builtin_return_address(0));
return 0;
}
EXPORT_SYMBOL(_spin_trylock_bh);
notrace int in_lock_functions(unsigned long addr)
{
/* Linker adds these: start and end of __lockfunc functions */
extern char __lock_text_start[], __lock_text_end[];
return addr >= (unsigned long)__lock_text_start
&& addr < (unsigned long)__lock_text_end;
}
EXPORT_SYMBOL(in_lock_functions);
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