diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/Kconfig | 10 | ||||
| -rw-r--r-- | lib/Kconfig.debug | 19 | ||||
| -rw-r--r-- | lib/Makefile | 1 | ||||
| -rw-r--r-- | lib/debugobjects.c | 20 | ||||
| -rw-r--r-- | lib/dump_stack.c | 4 | ||||
| -rw-r--r-- | lib/dynamic_debug.c | 2 | ||||
| -rw-r--r-- | lib/earlycpio.c | 27 | ||||
| -rw-r--r-- | lib/kobject.c | 22 | ||||
| -rw-r--r-- | lib/lockref.c | 128 | ||||
| -rw-r--r-- | lib/swiotlb.c | 8 |
10 files changed, 212 insertions, 29 deletions
diff --git a/lib/Kconfig b/lib/Kconfig index 71d9f81..6556171 100644 --- a/lib/Kconfig +++ b/lib/Kconfig @@ -48,6 +48,16 @@ config STMP_DEVICE config PERCPU_RWSEM boolean +config ARCH_USE_CMPXCHG_LOCKREF + bool + +config CMPXCHG_LOCKREF + def_bool y if ARCH_USE_CMPXCHG_LOCKREF + depends on SMP + depends on !GENERIC_LOCKBREAK + depends on !DEBUG_SPINLOCK + depends on !DEBUG_LOCK_ALLOC + config CRC_CCITT tristate "CRC-CCITT functions" help diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 1501aa5..444e1c1 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -981,6 +981,25 @@ config DEBUG_KOBJECT If you say Y here, some extra kobject debugging messages will be sent to the syslog. +config DEBUG_KOBJECT_RELEASE + bool "kobject release debugging" + depends on DEBUG_KERNEL + help + kobjects are reference counted objects. This means that their + last reference count put is not predictable, and the kobject can + live on past the point at which a driver decides to drop it's + initial reference to the kobject gained on allocation. An + example of this would be a struct device which has just been + unregistered. + + However, some buggy drivers assume that after such an operation, + the memory backing the kobject can be immediately freed. This + goes completely against the principles of a refcounted object. + + If you say Y here, the kernel will delay the release of kobjects + on the last reference count to improve the visibility of this + kind of kobject release bug. + config HAVE_DEBUG_BUGVERBOSE bool diff --git a/lib/Makefile b/lib/Makefile index 7baccfd..f2cb308 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -20,6 +20,7 @@ lib-$(CONFIG_MMU) += ioremap.o lib-$(CONFIG_SMP) += cpumask.o lib-y += kobject.o klist.o +obj-y += lockref.o obj-y += bcd.o div64.o sort.o parser.o halfmd4.o debug_locks.o random32.o \ bust_spinlocks.o hexdump.o kasprintf.o bitmap.o scatterlist.o \ diff --git a/lib/debugobjects.c b/lib/debugobjects.c index 37061ed..bf2c8b1 100644 --- a/lib/debugobjects.c +++ b/lib/debugobjects.c @@ -381,19 +381,21 @@ void debug_object_init_on_stack(void *addr, struct debug_obj_descr *descr) * debug_object_activate - debug checks when an object is activated * @addr: address of the object * @descr: pointer to an object specific debug description structure + * Returns 0 for success, -EINVAL for check failed. */ -void debug_object_activate(void *addr, struct debug_obj_descr *descr) +int debug_object_activate(void *addr, struct debug_obj_descr *descr) { enum debug_obj_state state; struct debug_bucket *db; struct debug_obj *obj; unsigned long flags; + int ret; struct debug_obj o = { .object = addr, .state = ODEBUG_STATE_NOTAVAILABLE, .descr = descr }; if (!debug_objects_enabled) - return; + return 0; db = get_bucket((unsigned long) addr); @@ -405,23 +407,26 @@ void debug_object_activate(void *addr, struct debug_obj_descr *descr) case ODEBUG_STATE_INIT: case ODEBUG_STATE_INACTIVE: obj->state = ODEBUG_STATE_ACTIVE; + ret = 0; break; case ODEBUG_STATE_ACTIVE: debug_print_object(obj, "activate"); state = obj->state; raw_spin_unlock_irqrestore(&db->lock, flags); - debug_object_fixup(descr->fixup_activate, addr, state); - return; + ret = debug_object_fixup(descr->fixup_activate, addr, state); + return ret ? -EINVAL : 0; case ODEBUG_STATE_DESTROYED: debug_print_object(obj, "activate"); + ret = -EINVAL; break; default: + ret = 0; break; } raw_spin_unlock_irqrestore(&db->lock, flags); - return; + return ret; } raw_spin_unlock_irqrestore(&db->lock, flags); @@ -431,8 +436,11 @@ void debug_object_activate(void *addr, struct debug_obj_descr *descr) * true or not. */ if (debug_object_fixup(descr->fixup_activate, addr, - ODEBUG_STATE_NOTAVAILABLE)) + ODEBUG_STATE_NOTAVAILABLE)) { debug_print_object(&o, "activate"); + return -EINVAL; + } + return 0; } /** diff --git a/lib/dump_stack.c b/lib/dump_stack.c index c031541..f23b63f 100644 --- a/lib/dump_stack.c +++ b/lib/dump_stack.c @@ -23,7 +23,7 @@ static void __dump_stack(void) #ifdef CONFIG_SMP static atomic_t dump_lock = ATOMIC_INIT(-1); -void dump_stack(void) +asmlinkage void dump_stack(void) { int was_locked; int old; @@ -55,7 +55,7 @@ retry: preempt_enable(); } #else -void dump_stack(void) +asmlinkage void dump_stack(void) { __dump_stack(); } diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c index 99fec3a..c37aeac 100644 --- a/lib/dynamic_debug.c +++ b/lib/dynamic_debug.c @@ -309,7 +309,7 @@ static int ddebug_parse_query(char *words[], int nwords, struct ddebug_query *query, const char *modname) { unsigned int i; - int rc; + int rc = 0; /* check we have an even number of words */ if (nwords % 2 != 0) { diff --git a/lib/earlycpio.c b/lib/earlycpio.c index 7aa7ce2..3eb3e47 100644 --- a/lib/earlycpio.c +++ b/lib/earlycpio.c @@ -49,22 +49,23 @@ enum cpio_fields { /** * cpio_data find_cpio_data - Search for files in an uncompressed cpio - * @path: The directory to search for, including a slash at the end - * @data: Pointer to the the cpio archive or a header inside - * @len: Remaining length of the cpio based on data pointer - * @offset: When a matching file is found, this is the offset to the - * beginning of the cpio. It can be used to iterate through - * the cpio to find all files inside of a directory path + * @path: The directory to search for, including a slash at the end + * @data: Pointer to the the cpio archive or a header inside + * @len: Remaining length of the cpio based on data pointer + * @nextoff: When a matching file is found, this is the offset from the + * beginning of the cpio to the beginning of the next file, not the + * matching file itself. It can be used to iterate through the cpio + * to find all files inside of a directory path. * - * @return: struct cpio_data containing the address, length and - * filename (with the directory path cut off) of the found file. - * If you search for a filename and not for files in a directory, - * pass the absolute path of the filename in the cpio and make sure - * the match returned an empty filename string. + * @return: struct cpio_data containing the address, length and + * filename (with the directory path cut off) of the found file. + * If you search for a filename and not for files in a directory, + * pass the absolute path of the filename in the cpio and make sure + * the match returned an empty filename string. */ struct cpio_data find_cpio_data(const char *path, void *data, - size_t len, long *offset) + size_t len, long *nextoff) { const size_t cpio_header_len = 8*C_NFIELDS - 2; struct cpio_data cd = { NULL, 0, "" }; @@ -124,7 +125,7 @@ struct cpio_data find_cpio_data(const char *path, void *data, if ((ch[C_MODE] & 0170000) == 0100000 && ch[C_NAMESIZE] >= mypathsize && !memcmp(p, path, mypathsize)) { - *offset = (long)nptr - (long)data; + *nextoff = (long)nptr - (long)data; if (ch[C_NAMESIZE] - mypathsize >= MAX_CPIO_FILE_NAME) { pr_warn( "File %s exceeding MAX_CPIO_FILE_NAME [%d]\n", diff --git a/lib/kobject.c b/lib/kobject.c index 4a1f33d..1d46c15 100644 --- a/lib/kobject.c +++ b/lib/kobject.c @@ -545,8 +545,8 @@ static void kobject_cleanup(struct kobject *kobj) struct kobj_type *t = get_ktype(kobj); const char *name = kobj->name; - pr_debug("kobject: '%s' (%p): %s\n", - kobject_name(kobj), kobj, __func__); + pr_debug("kobject: '%s' (%p): %s, parent %p\n", + kobject_name(kobj), kobj, __func__, kobj->parent); if (t && !t->release) pr_debug("kobject: '%s' (%p): does not have a release() " @@ -580,9 +580,25 @@ static void kobject_cleanup(struct kobject *kobj) } } +#ifdef CONFIG_DEBUG_KOBJECT_RELEASE +static void kobject_delayed_cleanup(struct work_struct *work) +{ + kobject_cleanup(container_of(to_delayed_work(work), + struct kobject, release)); +} +#endif + static void kobject_release(struct kref *kref) { - kobject_cleanup(container_of(kref, struct kobject, kref)); + struct kobject *kobj = container_of(kref, struct kobject, kref); +#ifdef CONFIG_DEBUG_KOBJECT_RELEASE + pr_debug("kobject: '%s' (%p): %s, parent %p (delayed)\n", + kobject_name(kobj), kobj, __func__, kobj->parent); + INIT_DELAYED_WORK(&kobj->release, kobject_delayed_cleanup); + schedule_delayed_work(&kobj->release, HZ); +#else + kobject_cleanup(kobj); +#endif } /** diff --git a/lib/lockref.c b/lib/lockref.c new file mode 100644 index 0000000..9d76f40 --- /dev/null +++ b/lib/lockref.c @@ -0,0 +1,128 @@ +#include <linux/export.h> +#include <linux/lockref.h> + +#ifdef CONFIG_CMPXCHG_LOCKREF + +/* + * Note that the "cmpxchg()" reloads the "old" value for the + * failure case. + */ +#define CMPXCHG_LOOP(CODE, SUCCESS) do { \ + struct lockref old; \ + BUILD_BUG_ON(sizeof(old) != 8); \ + old.lock_count = ACCESS_ONCE(lockref->lock_count); \ + while (likely(arch_spin_value_unlocked(old.lock.rlock.raw_lock))) { \ + struct lockref new = old, prev = old; \ + CODE \ + old.lock_count = cmpxchg(&lockref->lock_count, \ + old.lock_count, new.lock_count); \ + if (likely(old.lock_count == prev.lock_count)) { \ + SUCCESS; \ + } \ + cpu_relax(); \ + } \ +} while (0) + +#else + +#define CMPXCHG_LOOP(CODE, SUCCESS) do { } while (0) + +#endif + +/** + * lockref_get - Increments reference count unconditionally + * @lockcnt: pointer to lockref structure + * + * This operation is only valid if you already hold a reference + * to the object, so you know the count cannot be zero. + */ +void lockref_get(struct lockref *lockref) +{ + CMPXCHG_LOOP( + new.count++; + , + return; + ); + + spin_lock(&lockref->lock); + lockref->count++; + spin_unlock(&lockref->lock); +} +EXPORT_SYMBOL(lockref_get); + +/** + * lockref_get_not_zero - Increments count unless the count is 0 + * @lockcnt: pointer to lockref structure + * Return: 1 if count updated successfully or 0 if count was zero + */ +int lockref_get_not_zero(struct lockref *lockref) +{ + int retval; + + CMPXCHG_LOOP( + new.count++; + if (!old.count) + return 0; + , + return 1; + ); + + spin_lock(&lockref->lock); + retval = 0; + if (lockref->count) { + lockref->count++; + retval = 1; + } + spin_unlock(&lockref->lock); + return retval; +} +EXPORT_SYMBOL(lockref_get_not_zero); + +/** + * lockref_get_or_lock - Increments count unless the count is 0 + * @lockcnt: pointer to lockref structure + * Return: 1 if count updated successfully or 0 if count was zero + * and we got the lock instead. + */ +int lockref_get_or_lock(struct lockref *lockref) +{ + CMPXCHG_LOOP( + new.count++; + if (!old.count) + break; + , + return 1; + ); + + spin_lock(&lockref->lock); + if (!lockref->count) + return 0; + lockref->count++; + spin_unlock(&lockref->lock); + return 1; +} +EXPORT_SYMBOL(lockref_get_or_lock); + +/** + * lockref_put_or_lock - decrements count unless count <= 1 before decrement + * @lockcnt: pointer to lockref structure + * Return: 1 if count updated successfully or 0 if count <= 1 and lock taken + */ +int lockref_put_or_lock(struct lockref *lockref) +{ + CMPXCHG_LOOP( + new.count--; + if (old.count <= 1) + break; + , + return 1; + ); + + spin_lock(&lockref->lock); + if (lockref->count <= 1) + return 0; + lockref->count--; + spin_unlock(&lockref->lock); + return 1; +} +EXPORT_SYMBOL(lockref_put_or_lock); diff --git a/lib/swiotlb.c b/lib/swiotlb.c index d23762e..4e8686c 100644 --- a/lib/swiotlb.c +++ b/lib/swiotlb.c @@ -870,13 +870,13 @@ swiotlb_map_sg_attrs(struct device *hwdev, struct scatterlist *sgl, int nelems, swiotlb_full(hwdev, sg->length, dir, 0); swiotlb_unmap_sg_attrs(hwdev, sgl, i, dir, attrs); - sgl[0].dma_length = 0; + sg_dma_len(sgl) = 0; return 0; } sg->dma_address = phys_to_dma(hwdev, map); } else sg->dma_address = dev_addr; - sg->dma_length = sg->length; + sg_dma_len(sg) = sg->length; } return nelems; } @@ -904,7 +904,7 @@ swiotlb_unmap_sg_attrs(struct device *hwdev, struct scatterlist *sgl, BUG_ON(dir == DMA_NONE); for_each_sg(sgl, sg, nelems, i) - unmap_single(hwdev, sg->dma_address, sg->dma_length, dir); + unmap_single(hwdev, sg->dma_address, sg_dma_len(sg), dir); } EXPORT_SYMBOL(swiotlb_unmap_sg_attrs); @@ -934,7 +934,7 @@ swiotlb_sync_sg(struct device *hwdev, struct scatterlist *sgl, for_each_sg(sgl, sg, nelems, i) swiotlb_sync_single(hwdev, sg->dma_address, - sg->dma_length, dir, target); + sg_dma_len(sg), dir, target); } void |
