From 8b05c7e6e159d2f33c9275281b8b909a89eb7c5d Mon Sep 17 00:00:00 2001 From: FUJITA Tomonori Date: Wed, 23 Jul 2008 21:26:53 -0700 Subject: add a helper function to test if an object is on the stack lib/debugobjects.c has a function to test if an object is on the stack. The block layer and ide needs it (they need to avoid DMA from/to stack buffers). This patch moves the function to include/linux/sched.h so that everyone can use it. lib/debugobjects.c uses current->stack but this patch uses a task_stack_page() accessor, which is a preferable way to access the stack. Signed-off-by: FUJITA Tomonori Cc: Christoph Lameter Cc: Andy Whitcroft Cc: Ingo Molnar Cc: Thomas Gleixner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- lib/debugobjects.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) (limited to 'lib/debugobjects.c') diff --git a/lib/debugobjects.c b/lib/debugobjects.c index 85b18d79be8..f86196390cf 100644 --- a/lib/debugobjects.c +++ b/lib/debugobjects.c @@ -226,15 +226,13 @@ debug_object_fixup(int (*fixup)(void *addr, enum debug_obj_state state), static void debug_object_is_on_stack(void *addr, int onstack) { - void *stack = current->stack; int is_on_stack; static int limit; if (limit > 4) return; - is_on_stack = (addr >= stack && addr < (stack + THREAD_SIZE)); - + is_on_stack = object_is_on_stack(addr); if (is_on_stack == onstack) return; -- cgit v1.2.3-70-g09d2 From 5cd2b459d326a424671dcd95f038649f7bf7cb96 Mon Sep 17 00:00:00 2001 From: Arjan van de Ven Date: Fri, 25 Jul 2008 19:45:39 -0700 Subject: Use WARN() in lib/ Use WARN() instead of a printk+WARN_ON() pair; this way the message becomes part of the warning section for better reporting/collection. In addition, one of the if() clauses collapes into the WARN() entirely now. Signed-off-by: Arjan van de Ven Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- lib/debugobjects.c | 15 +++++---------- lib/iomap.c | 3 +-- lib/kobject_uevent.c | 6 ++---- lib/plist.c | 13 +++++++------ 4 files changed, 15 insertions(+), 22 deletions(-) (limited to 'lib/debugobjects.c') diff --git a/lib/debugobjects.c b/lib/debugobjects.c index f86196390cf..45a6bde762d 100644 --- a/lib/debugobjects.c +++ b/lib/debugobjects.c @@ -205,9 +205,8 @@ static void debug_print_object(struct debug_obj *obj, char *msg) if (limit < 5 && obj->descr != descr_test) { limit++; - printk(KERN_ERR "ODEBUG: %s %s object type: %s\n", msg, + WARN(1, KERN_ERR "ODEBUG: %s %s object type: %s\n", msg, obj_states[obj->state], obj->descr->name); - WARN_ON(1); } debug_objects_warnings++; } @@ -733,26 +732,22 @@ check_results(void *addr, enum debug_obj_state state, int fixups, int warnings) obj = lookup_object(addr, db); if (!obj && state != ODEBUG_STATE_NONE) { - printk(KERN_ERR "ODEBUG: selftest object not found\n"); - WARN_ON(1); + WARN(1, KERN_ERR "ODEBUG: selftest object not found\n"); goto out; } if (obj && obj->state != state) { - printk(KERN_ERR "ODEBUG: selftest wrong state: %d != %d\n", + WARN(1, KERN_ERR "ODEBUG: selftest wrong state: %d != %d\n", obj->state, state); - WARN_ON(1); goto out; } if (fixups != debug_objects_fixups) { - printk(KERN_ERR "ODEBUG: selftest fixups failed %d != %d\n", + WARN(1, KERN_ERR "ODEBUG: selftest fixups failed %d != %d\n", fixups, debug_objects_fixups); - WARN_ON(1); goto out; } if (warnings != debug_objects_warnings) { - printk(KERN_ERR "ODEBUG: selftest warnings failed %d != %d\n", + WARN(1, KERN_ERR "ODEBUG: selftest warnings failed %d != %d\n", warnings, debug_objects_warnings); - WARN_ON(1); goto out; } res = 0; diff --git a/lib/iomap.c b/lib/iomap.c index 37a3ea4cac9..d3222938515 100644 --- a/lib/iomap.c +++ b/lib/iomap.c @@ -40,8 +40,7 @@ static void bad_io_access(unsigned long port, const char *access) static int count = 10; if (count) { count--; - printk(KERN_ERR "Bad IO access at port %#lx (%s)\n", port, access); - WARN_ON(1); + WARN(1, KERN_ERR "Bad IO access at port %#lx (%s)\n", port, access); } } diff --git a/lib/kobject_uevent.c b/lib/kobject_uevent.c index 9f8d599459d..3f914725bda 100644 --- a/lib/kobject_uevent.c +++ b/lib/kobject_uevent.c @@ -285,8 +285,7 @@ int add_uevent_var(struct kobj_uevent_env *env, const char *format, ...) int len; if (env->envp_idx >= ARRAY_SIZE(env->envp)) { - printk(KERN_ERR "add_uevent_var: too many keys\n"); - WARN_ON(1); + WARN(1, KERN_ERR "add_uevent_var: too many keys\n"); return -ENOMEM; } @@ -297,8 +296,7 @@ int add_uevent_var(struct kobj_uevent_env *env, const char *format, ...) va_end(args); if (len >= (sizeof(env->buf) - env->buflen)) { - printk(KERN_ERR "add_uevent_var: buffer size too small\n"); - WARN_ON(1); + WARN(1, KERN_ERR "add_uevent_var: buffer size too small\n"); return -ENOMEM; } diff --git a/lib/plist.c b/lib/plist.c index 3074a02272f..d6c64a824e1 100644 --- a/lib/plist.c +++ b/lib/plist.c @@ -31,12 +31,13 @@ static void plist_check_prev_next(struct list_head *t, struct list_head *p, struct list_head *n) { - if (n->prev != p || p->next != n) { - printk("top: %p, n: %p, p: %p\n", t, t->next, t->prev); - printk("prev: %p, n: %p, p: %p\n", p, p->next, p->prev); - printk("next: %p, n: %p, p: %p\n", n, n->next, n->prev); - WARN_ON(1); - } + WARN(n->prev != p || p->next != n, + "top: %p, n: %p, p: %p\n" + "prev: %p, n: %p, p: %p\n" + "next: %p, n: %p, p: %p\n", + t, t->next, t->prev, + p, p->next, p->prev, + n, n->next, n->prev); } static void plist_check_list(struct list_head *top) -- cgit v1.2.3-70-g09d2 From 673d62cc5ea6fca046650f17f77985b112c62322 Mon Sep 17 00:00:00 2001 From: Vegard Nossum Date: Sun, 31 Aug 2008 23:39:21 +0200 Subject: debugobjects: fix lockdep warning Daniel J. Blueman reported: > ======================================================= > [ INFO: possible circular locking dependency detected ] > 2.6.27-rc4-224c #1 > ------------------------------------------------------- > hald/4680 is trying to acquire lock: > (&n->list_lock){++..}, at: [] add_partial+0x26/0x80 > > but task is already holding lock: > (&obj_hash[i].lock){++..}, at: [] > debug_object_free+0x5c/0x120 We fix it by moving the actual freeing to outside the lock (the lock now only protects the list). The pool lock is also promoted to irq-safe (suggested by Dan). It's necessary because free_pool is now called outside the irq disabled region. So we need to protect against an interrupt handler which calls debug_object_init(). [tglx@linutronix.de: added hlist_move_list helper to avoid looping through the list twice] Reported-by: Daniel J Blueman Signed-off-by: Vegard Nossum Signed-off-by: Thomas Gleixner --- include/linux/list.h | 13 +++++++++++++ lib/debugobjects.c | 31 +++++++++++++++++++++++-------- 2 files changed, 36 insertions(+), 8 deletions(-) (limited to 'lib/debugobjects.c') diff --git a/include/linux/list.h b/include/linux/list.h index db35ef02e74..969f6e92d08 100644 --- a/include/linux/list.h +++ b/include/linux/list.h @@ -619,6 +619,19 @@ static inline void hlist_add_after(struct hlist_node *n, next->next->pprev = &next->next; } +/* + * Move a list from one list head to another. Fixup the pprev + * reference of the first entry if it exists. + */ +static inline void hlist_move_list(struct hlist_head *old, + struct hlist_head *new) +{ + new->first = old->first; + if (new->first) + new->first->pprev = &new->first; + old->first = NULL; +} + #define hlist_entry(ptr, type, member) container_of(ptr,type,member) #define hlist_for_each(pos, head) \ diff --git a/lib/debugobjects.c b/lib/debugobjects.c index 45a6bde762d..e3ab374e133 100644 --- a/lib/debugobjects.c +++ b/lib/debugobjects.c @@ -112,6 +112,7 @@ static struct debug_obj *lookup_object(void *addr, struct debug_bucket *b) /* * Allocate a new object. If the pool is empty, switch off the debugger. + * Must be called with interrupts disabled. */ static struct debug_obj * alloc_object(void *addr, struct debug_bucket *b, struct debug_obj_descr *descr) @@ -148,17 +149,18 @@ alloc_object(void *addr, struct debug_bucket *b, struct debug_obj_descr *descr) static void free_object(struct debug_obj *obj) { unsigned long idx = (unsigned long)(obj - obj_static_pool); + unsigned long flags; if (obj_pool_free < ODEBUG_POOL_SIZE || idx < ODEBUG_POOL_SIZE) { - spin_lock(&pool_lock); + spin_lock_irqsave(&pool_lock, flags); hlist_add_head(&obj->node, &obj_pool); obj_pool_free++; obj_pool_used--; - spin_unlock(&pool_lock); + spin_unlock_irqrestore(&pool_lock, flags); } else { - spin_lock(&pool_lock); + spin_lock_irqsave(&pool_lock, flags); obj_pool_used--; - spin_unlock(&pool_lock); + spin_unlock_irqrestore(&pool_lock, flags); kmem_cache_free(obj_cache, obj); } } @@ -171,6 +173,7 @@ static void debug_objects_oom(void) { struct debug_bucket *db = obj_hash; struct hlist_node *node, *tmp; + HLIST_HEAD(freelist); struct debug_obj *obj; unsigned long flags; int i; @@ -179,11 +182,14 @@ static void debug_objects_oom(void) for (i = 0; i < ODEBUG_HASH_SIZE; i++, db++) { spin_lock_irqsave(&db->lock, flags); - hlist_for_each_entry_safe(obj, node, tmp, &db->list, node) { + hlist_move_list(&db->list, &freelist); + spin_unlock_irqrestore(&db->lock, flags); + + /* Now free them */ + hlist_for_each_entry_safe(obj, node, tmp, &freelist, node) { hlist_del(&obj->node); free_object(obj); } - spin_unlock_irqrestore(&db->lock, flags); } } @@ -498,8 +504,9 @@ void debug_object_free(void *addr, struct debug_obj_descr *descr) return; default: hlist_del(&obj->node); + spin_unlock_irqrestore(&db->lock, flags); free_object(obj); - break; + return; } out_unlock: spin_unlock_irqrestore(&db->lock, flags); @@ -510,6 +517,7 @@ static void __debug_check_no_obj_freed(const void *address, unsigned long size) { unsigned long flags, oaddr, saddr, eaddr, paddr, chunks; struct hlist_node *node, *tmp; + HLIST_HEAD(freelist); struct debug_obj_descr *descr; enum debug_obj_state state; struct debug_bucket *db; @@ -545,11 +553,18 @@ repeat: goto repeat; default: hlist_del(&obj->node); - free_object(obj); + hlist_add_head(&obj->node, &freelist); break; } } spin_unlock_irqrestore(&db->lock, flags); + + /* Now free them */ + hlist_for_each_entry_safe(obj, node, tmp, &freelist, node) { + hlist_del(&obj->node); + free_object(obj); + } + if (cnt > debug_objects_maxchain) debug_objects_maxchain = cnt; } -- cgit v1.2.3-70-g09d2