diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/Kconfig.debug | 8 | ||||
| -rw-r--r-- | lib/Makefile | 1 | ||||
| -rw-r--r-- | lib/dec_and_lock.c | 3 | ||||
| -rw-r--r-- | lib/kernel_lock.c | 3 | ||||
| -rw-r--r-- | lib/radix-tree.c | 2 | ||||
| -rw-r--r-- | lib/sort.c | 5 | ||||
| -rw-r--r-- | lib/spinlock_debug.c | 257 |
7 files changed, 267 insertions, 12 deletions
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 3754c9a8f5c..016e89a44ac 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -170,11 +170,11 @@ config DEBUG_FS config FRAME_POINTER bool "Compile the kernel with frame pointers" - depends on DEBUG_KERNEL && ((X86 && !X86_64) || CRIS || M68K || M68KNOMMU || FRV || UML) + depends on DEBUG_KERNEL && (X86 || CRIS || M68K || M68KNOMMU || FRV || UML) default y if DEBUG_INFO && UML help If you say Y here the resulting kernel image will be slightly larger - and slower, but it will give very useful debugging information. - If you don't debug the kernel, you can say N, but we may not be able - to solve problems without frame pointers. + and slower, but it might give very useful debugging information + on some architectures or you use external debuggers. + If you don't debug the kernel, you can say N. diff --git a/lib/Makefile b/lib/Makefile index d9c38ba05e7..44a46750690 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -16,6 +16,7 @@ CFLAGS_kobject.o += -DDEBUG CFLAGS_kobject_uevent.o += -DDEBUG endif +obj-$(CONFIG_DEBUG_SPINLOCK) += spinlock_debug.o lib-$(CONFIG_RWSEM_GENERIC_SPINLOCK) += rwsem-spinlock.o lib-$(CONFIG_RWSEM_XCHGADD_ALGORITHM) += rwsem.o lib-$(CONFIG_SEMAPHORE_SLEEPERS) += semaphore-sleepers.o diff --git a/lib/dec_and_lock.c b/lib/dec_and_lock.c index 6658d81e183..2377af057d0 100644 --- a/lib/dec_and_lock.c +++ b/lib/dec_and_lock.c @@ -25,8 +25,6 @@ * this is trivially done efficiently using a load-locked * store-conditional approach, for example. */ - -#ifndef ATOMIC_DEC_AND_LOCK int _atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock) { spin_lock(lock); @@ -37,4 +35,3 @@ int _atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock) } EXPORT_SYMBOL(_atomic_dec_and_lock); -#endif diff --git a/lib/kernel_lock.c b/lib/kernel_lock.c index bd2bc5d887b..cb5490ec00f 100644 --- a/lib/kernel_lock.c +++ b/lib/kernel_lock.c @@ -177,8 +177,7 @@ static inline void __lock_kernel(void) static inline void __unlock_kernel(void) { - _raw_spin_unlock(&kernel_flag); - preempt_enable(); + spin_unlock(&kernel_flag); } /* diff --git a/lib/radix-tree.c b/lib/radix-tree.c index b972dd29289..6a8bc6e0643 100644 --- a/lib/radix-tree.c +++ b/lib/radix-tree.c @@ -110,7 +110,7 @@ radix_tree_node_free(struct radix_tree_node *node) * success, return zero, with preemption disabled. On error, return -ENOMEM * with preemption not disabled. */ -int radix_tree_preload(int gfp_mask) +int radix_tree_preload(unsigned int __nocast gfp_mask) { struct radix_tree_preload *rtp; struct radix_tree_node *node; diff --git a/lib/sort.c b/lib/sort.c index b73dbb0e7c8..ddc4d35df28 100644 --- a/lib/sort.c +++ b/lib/sort.c @@ -6,15 +6,16 @@ #include <linux/kernel.h> #include <linux/module.h> +#include <linux/sort.h> -void u32_swap(void *a, void *b, int size) +static void u32_swap(void *a, void *b, int size) { u32 t = *(u32 *)a; *(u32 *)a = *(u32 *)b; *(u32 *)b = t; } -void generic_swap(void *a, void *b, int size) +static void generic_swap(void *a, void *b, int size) { char t; diff --git a/lib/spinlock_debug.c b/lib/spinlock_debug.c new file mode 100644 index 00000000000..906ad101eab --- /dev/null +++ b/lib/spinlock_debug.c @@ -0,0 +1,257 @@ +/* + * Copyright 2005, Red Hat, Inc., Ingo Molnar + * Released under the General Public License (GPL). + * + * This file contains the spinlock/rwlock implementations for + * DEBUG_SPINLOCK. + */ + +#include <linux/config.h> +#include <linux/spinlock.h> +#include <linux/interrupt.h> +#include <linux/delay.h> + +static void spin_bug(spinlock_t *lock, const char *msg) +{ + static long print_once = 1; + struct task_struct *owner = NULL; + + if (xchg(&print_once, 0)) { + if (lock->owner && lock->owner != SPINLOCK_OWNER_INIT) + owner = lock->owner; + printk("BUG: spinlock %s on CPU#%d, %s/%d\n", + msg, smp_processor_id(), current->comm, current->pid); + printk(" lock: %p, .magic: %08x, .owner: %s/%d, .owner_cpu: %d\n", + lock, lock->magic, + owner ? owner->comm : "<none>", + owner ? owner->pid : -1, + lock->owner_cpu); + dump_stack(); +#ifdef CONFIG_SMP + /* + * We cannot continue on SMP: + */ +// panic("bad locking"); +#endif + } +} + +#define SPIN_BUG_ON(cond, lock, msg) if (unlikely(cond)) spin_bug(lock, msg) + +static inline void debug_spin_lock_before(spinlock_t *lock) +{ + SPIN_BUG_ON(lock->magic != SPINLOCK_MAGIC, lock, "bad magic"); + SPIN_BUG_ON(lock->owner == current, lock, "recursion"); + SPIN_BUG_ON(lock->owner_cpu == raw_smp_processor_id(), + lock, "cpu recursion"); +} + +static inline void debug_spin_lock_after(spinlock_t *lock) +{ + lock->owner_cpu = raw_smp_processor_id(); + lock->owner = current; +} + +static inline void debug_spin_unlock(spinlock_t *lock) +{ + SPIN_BUG_ON(lock->magic != SPINLOCK_MAGIC, lock, "bad magic"); + SPIN_BUG_ON(!spin_is_locked(lock), lock, "already unlocked"); + SPIN_BUG_ON(lock->owner != current, lock, "wrong owner"); + SPIN_BUG_ON(lock->owner_cpu != raw_smp_processor_id(), + lock, "wrong CPU"); + lock->owner = SPINLOCK_OWNER_INIT; + lock->owner_cpu = -1; +} + +static void __spin_lock_debug(spinlock_t *lock) +{ + int print_once = 1; + u64 i; + + for (;;) { + for (i = 0; i < loops_per_jiffy * HZ; i++) { + cpu_relax(); + if (__raw_spin_trylock(&lock->raw_lock)) + return; + } + /* lockup suspected: */ + if (print_once) { + print_once = 0; + printk("BUG: spinlock lockup on CPU#%d, %s/%d, %p\n", + smp_processor_id(), current->comm, current->pid, + lock); + dump_stack(); + } + } +} + +void _raw_spin_lock(spinlock_t *lock) +{ + debug_spin_lock_before(lock); + if (unlikely(!__raw_spin_trylock(&lock->raw_lock))) + __spin_lock_debug(lock); + debug_spin_lock_after(lock); +} + +int _raw_spin_trylock(spinlock_t *lock) +{ + int ret = __raw_spin_trylock(&lock->raw_lock); + + if (ret) + debug_spin_lock_after(lock); +#ifndef CONFIG_SMP + /* + * Must not happen on UP: + */ + SPIN_BUG_ON(!ret, lock, "trylock failure on UP"); +#endif + return ret; +} + +void _raw_spin_unlock(spinlock_t *lock) +{ + debug_spin_unlock(lock); + __raw_spin_unlock(&lock->raw_lock); +} + +static void rwlock_bug(rwlock_t *lock, const char *msg) +{ + static long print_once = 1; + + if (xchg(&print_once, 0)) { + printk("BUG: rwlock %s on CPU#%d, %s/%d, %p\n", msg, + smp_processor_id(), current->comm, current->pid, lock); + dump_stack(); +#ifdef CONFIG_SMP + /* + * We cannot continue on SMP: + */ + panic("bad locking"); +#endif + } +} + +#define RWLOCK_BUG_ON(cond, lock, msg) if (unlikely(cond)) rwlock_bug(lock, msg) + +static void __read_lock_debug(rwlock_t *lock) +{ + int print_once = 1; + u64 i; + + for (;;) { + for (i = 0; i < loops_per_jiffy * HZ; i++) { + cpu_relax(); + if (__raw_read_trylock(&lock->raw_lock)) + return; + } + /* lockup suspected: */ + if (print_once) { + print_once = 0; + printk("BUG: read-lock lockup on CPU#%d, %s/%d, %p\n", + smp_processor_id(), current->comm, current->pid, + lock); + dump_stack(); + } + } +} + +void _raw_read_lock(rwlock_t *lock) +{ + RWLOCK_BUG_ON(lock->magic != RWLOCK_MAGIC, lock, "bad magic"); + if (unlikely(!__raw_read_trylock(&lock->raw_lock))) + __read_lock_debug(lock); +} + +int _raw_read_trylock(rwlock_t *lock) +{ + int ret = __raw_read_trylock(&lock->raw_lock); + +#ifndef CONFIG_SMP + /* + * Must not happen on UP: + */ + RWLOCK_BUG_ON(!ret, lock, "trylock failure on UP"); +#endif + return ret; +} + +void _raw_read_unlock(rwlock_t *lock) +{ + RWLOCK_BUG_ON(lock->magic != RWLOCK_MAGIC, lock, "bad magic"); + __raw_read_unlock(&lock->raw_lock); +} + +static inline void debug_write_lock_before(rwlock_t *lock) +{ + RWLOCK_BUG_ON(lock->magic != RWLOCK_MAGIC, lock, "bad magic"); + RWLOCK_BUG_ON(lock->owner == current, lock, "recursion"); + RWLOCK_BUG_ON(lock->owner_cpu == raw_smp_processor_id(), + lock, "cpu recursion"); +} + +static inline void debug_write_lock_after(rwlock_t *lock) +{ + lock->owner_cpu = raw_smp_processor_id(); + lock->owner = current; +} + +static inline void debug_write_unlock(rwlock_t *lock) +{ + RWLOCK_BUG_ON(lock->magic != RWLOCK_MAGIC, lock, "bad magic"); + RWLOCK_BUG_ON(lock->owner != current, lock, "wrong owner"); + RWLOCK_BUG_ON(lock->owner_cpu != raw_smp_processor_id(), + lock, "wrong CPU"); + lock->owner = SPINLOCK_OWNER_INIT; + lock->owner_cpu = -1; +} + +static void __write_lock_debug(rwlock_t *lock) +{ + int print_once = 1; + u64 i; + + for (;;) { + for (i = 0; i < loops_per_jiffy * HZ; i++) { + cpu_relax(); + if (__raw_write_trylock(&lock->raw_lock)) + return; + } + /* lockup suspected: */ + if (print_once) { + print_once = 0; + printk("BUG: write-lock lockup on CPU#%d, %s/%d, %p\n", + smp_processor_id(), current->comm, current->pid, + lock); + dump_stack(); + } + } +} + +void _raw_write_lock(rwlock_t *lock) +{ + debug_write_lock_before(lock); + if (unlikely(!__raw_write_trylock(&lock->raw_lock))) + __write_lock_debug(lock); + debug_write_lock_after(lock); +} + +int _raw_write_trylock(rwlock_t *lock) +{ + int ret = __raw_write_trylock(&lock->raw_lock); + + if (ret) + debug_write_lock_after(lock); +#ifndef CONFIG_SMP + /* + * Must not happen on UP: + */ + RWLOCK_BUG_ON(!ret, lock, "trylock failure on UP"); +#endif + return ret; +} + +void _raw_write_unlock(rwlock_t *lock) +{ + debug_write_unlock(lock); + __raw_write_unlock(&lock->raw_lock); +} |