From: Ingo Molnar It seems ppc64 wants to lock mutexes in early bootup code, with interrupts disabled, and they expect interrupts to stay disabled, else they crash. Work around this bug by making mutex debugging variants save/restore irq flags. Signed-off-by: Ingo Molnar Signed-off-by: Andrew Morton --- kernel/mutex-debug.c | 12 ++++++------ kernel/mutex-debug.h | 25 +++++-------------------- kernel/mutex.c | 21 ++++++++++++--------- kernel/mutex.h | 6 ++++-- 4 files changed, 27 insertions(+), 37 deletions(-) diff -puN kernel/mutex.c~work-around-ppc64-bootup-bug-by-making-mutex-debugging-save-restore-irqs kernel/mutex.c --- devel/kernel/mutex.c~work-around-ppc64-bootup-bug-by-making-mutex-debugging-save-restore-irqs 2006-01-18 18:42:19.000000000 -0800 +++ devel-akpm/kernel/mutex.c 2006-01-18 18:42:19.000000000 -0800 @@ -125,10 +125,11 @@ __mutex_lock_common(struct mutex *lock, struct task_struct *task = current; struct mutex_waiter waiter; unsigned int old_val; + unsigned long flags; debug_mutex_init_waiter(&waiter); - spin_lock_mutex(&lock->wait_lock); + spin_lock_mutex(&lock->wait_lock, flags); debug_mutex_add_waiter(lock, &waiter, task->thread_info, ip); @@ -157,7 +158,7 @@ __mutex_lock_common(struct mutex *lock, if (unlikely(state == TASK_INTERRUPTIBLE && signal_pending(task))) { mutex_remove_waiter(lock, &waiter, task->thread_info); - spin_unlock_mutex(&lock->wait_lock); + spin_unlock_mutex(&lock->wait_lock, flags); debug_mutex_free_waiter(&waiter); return -EINTR; @@ -165,9 +166,9 @@ __mutex_lock_common(struct mutex *lock, __set_task_state(task, state); /* didnt get the lock, go to sleep: */ - spin_unlock_mutex(&lock->wait_lock); + spin_unlock_mutex(&lock->wait_lock, flags); schedule(); - spin_lock_mutex(&lock->wait_lock); + spin_lock_mutex(&lock->wait_lock, flags); } /* got the lock - rejoice! */ @@ -178,7 +179,7 @@ __mutex_lock_common(struct mutex *lock, if (likely(list_empty(&lock->wait_list))) atomic_set(&lock->count, 0); - spin_unlock_mutex(&lock->wait_lock); + spin_unlock_mutex(&lock->wait_lock, flags); debug_mutex_free_waiter(&waiter); @@ -203,10 +204,11 @@ static fastcall noinline void __mutex_unlock_slowpath(atomic_t *lock_count __IP_DECL__) { struct mutex *lock = container_of(lock_count, struct mutex, count); + unsigned long flags; DEBUG_WARN_ON(lock->owner != current_thread_info()); - spin_lock_mutex(&lock->wait_lock); + spin_lock_mutex(&lock->wait_lock, flags); /* * some architectures leave the lock unlocked in the fastpath failure @@ -231,7 +233,7 @@ __mutex_unlock_slowpath(atomic_t *lock_c debug_mutex_clear_owner(lock); - spin_unlock_mutex(&lock->wait_lock); + spin_unlock_mutex(&lock->wait_lock, flags); } /* @@ -276,9 +278,10 @@ __mutex_lock_interruptible_slowpath(atom static inline int __mutex_trylock_slowpath(atomic_t *lock_count) { struct mutex *lock = container_of(lock_count, struct mutex, count); + unsigned long flags; int prev; - spin_lock_mutex(&lock->wait_lock); + spin_lock_mutex(&lock->wait_lock, flags); prev = atomic_xchg(&lock->count, -1); if (likely(prev == 1)) @@ -287,7 +290,7 @@ static inline int __mutex_trylock_slowpa if (likely(list_empty(&lock->wait_list))) atomic_set(&lock->count, 0); - spin_unlock_mutex(&lock->wait_lock); + spin_unlock_mutex(&lock->wait_lock, flags); return prev == 1; } diff -puN kernel/mutex-debug.c~work-around-ppc64-bootup-bug-by-making-mutex-debugging-save-restore-irqs kernel/mutex-debug.c --- devel/kernel/mutex-debug.c~work-around-ppc64-bootup-bug-by-making-mutex-debugging-save-restore-irqs 2006-01-18 18:42:19.000000000 -0800 +++ devel-akpm/kernel/mutex-debug.c 2006-01-18 18:42:19.000000000 -0800 @@ -153,13 +153,13 @@ next: continue; count++; cursor = curr->next; - debug_spin_lock_restore(&debug_mutex_lock, flags); + debug_spin_unlock_restore(&debug_mutex_lock, flags); printk("\n#%03d: ", count); printk_lock(lock, filter ? 0 : 1); goto next; } - debug_spin_lock_restore(&debug_mutex_lock, flags); + debug_spin_unlock_restore(&debug_mutex_lock, flags); printk("\n"); } @@ -316,7 +316,7 @@ void mutex_debug_check_no_locks_held(str continue; list_del_init(curr); DEBUG_OFF(); - debug_spin_lock_restore(&debug_mutex_lock, flags); + debug_spin_unlock_restore(&debug_mutex_lock, flags); printk("BUG: %s/%d, lock held at task exit time!\n", task->comm, task->pid); @@ -325,7 +325,7 @@ void mutex_debug_check_no_locks_held(str printk("exiting task is not even the owner??\n"); return; } - debug_spin_lock_restore(&debug_mutex_lock, flags); + debug_spin_unlock_restore(&debug_mutex_lock, flags); } /* @@ -352,7 +352,7 @@ void mutex_debug_check_no_locks_freed(co continue; list_del_init(curr); DEBUG_OFF(); - debug_spin_lock_restore(&debug_mutex_lock, flags); + debug_spin_unlock_restore(&debug_mutex_lock, flags); printk("BUG: %s/%d, active lock [%p(%p-%p)] freed!\n", current->comm, current->pid, lock, from, to); @@ -362,7 +362,7 @@ void mutex_debug_check_no_locks_freed(co printk("freeing task is not even the owner??\n"); return; } - debug_spin_lock_restore(&debug_mutex_lock, flags); + debug_spin_unlock_restore(&debug_mutex_lock, flags); } /* diff -puN kernel/mutex-debug.h~work-around-ppc64-bootup-bug-by-making-mutex-debugging-save-restore-irqs kernel/mutex-debug.h --- devel/kernel/mutex-debug.h~work-around-ppc64-bootup-bug-by-making-mutex-debugging-save-restore-irqs 2006-01-18 18:42:19.000000000 -0800 +++ devel-akpm/kernel/mutex-debug.h 2006-01-18 18:42:19.000000000 -0800 @@ -46,21 +46,6 @@ extern void mutex_remove_waiter(struct m extern void debug_mutex_unlock(struct mutex *lock); extern void debug_mutex_init(struct mutex *lock, const char *name); -#define debug_spin_lock(lock) \ - do { \ - local_irq_disable(); \ - if (debug_mutex_on) \ - spin_lock(lock); \ - } while (0) - -#define debug_spin_unlock(lock) \ - do { \ - if (debug_mutex_on) \ - spin_unlock(lock); \ - local_irq_enable(); \ - preempt_check_resched(); \ - } while (0) - #define debug_spin_lock_save(lock, flags) \ do { \ local_irq_save(flags); \ @@ -68,7 +53,7 @@ extern void debug_mutex_init(struct mute spin_lock(lock); \ } while (0) -#define debug_spin_lock_restore(lock, flags) \ +#define debug_spin_unlock_restore(lock, flags) \ do { \ if (debug_mutex_on) \ spin_unlock(lock); \ @@ -76,20 +61,20 @@ extern void debug_mutex_init(struct mute preempt_check_resched(); \ } while (0) -#define spin_lock_mutex(lock) \ +#define spin_lock_mutex(lock, flags) \ do { \ struct mutex *l = container_of(lock, struct mutex, wait_lock); \ \ DEBUG_WARN_ON(in_interrupt()); \ - debug_spin_lock(&debug_mutex_lock); \ + debug_spin_lock_save(&debug_mutex_lock, flags); \ spin_lock(lock); \ DEBUG_WARN_ON(l->magic != l); \ } while (0) -#define spin_unlock_mutex(lock) \ +#define spin_unlock_mutex(lock, flags) \ do { \ spin_unlock(lock); \ - debug_spin_unlock(&debug_mutex_lock); \ + debug_spin_unlock_restore(&debug_mutex_lock, flags); \ } while (0) #define DEBUG_OFF() \ diff -puN kernel/mutex.h~work-around-ppc64-bootup-bug-by-making-mutex-debugging-save-restore-irqs kernel/mutex.h --- devel/kernel/mutex.h~work-around-ppc64-bootup-bug-by-making-mutex-debugging-save-restore-irqs 2006-01-18 18:42:19.000000000 -0800 +++ devel-akpm/kernel/mutex.h 2006-01-18 18:42:19.000000000 -0800 @@ -9,8 +9,10 @@ * !CONFIG_DEBUG_MUTEXES case. Most of them are NOPs: */ -#define spin_lock_mutex(lock) spin_lock(lock) -#define spin_unlock_mutex(lock) spin_unlock(lock) +#define spin_lock_mutex(lock, flags) \ + do { spin_lock(lock); (void)(flags); } while (0) +#define spin_unlock_mutex(lock, flags) \ + do { spin_unlock(lock); (void)(flags); } while (0) #define mutex_remove_waiter(lock, waiter, ti) \ __list_del((waiter)->list.prev, (waiter)->list.next) _