diff options
| -rw-r--r-- | include/linux/lockdep.h | 7 | ||||
| -rw-r--r-- | kernel/lockdep.c | 284 | ||||
| -rw-r--r-- | kernel/lockdep_internals.h | 97 |
3 files changed, 175 insertions, 213 deletions
diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h index 9ec026f8d09..12aabfcb45f 100644 --- a/include/linux/lockdep.h +++ b/include/linux/lockdep.h @@ -58,7 +58,6 @@ struct lock_class { struct lockdep_subclass_key *key; unsigned int subclass; - unsigned int dep_gen_id; /* * IRQ/softirq usage tracking bits: @@ -150,9 +149,9 @@ struct lock_list { struct stack_trace trace; int distance; - /*The parent field is used to implement breadth-first search,and - *the bit 0 is reused to indicate if the lock has been accessed - *in BFS. + /* + * The parent field is used to implement breadth-first search, and the + * bit 0 is reused to indicate if the lock has been accessed in BFS. */ struct lock_list *parent; }; diff --git a/kernel/lockdep.c b/kernel/lockdep.c index 744da6265d9..1cedb00e3e7 100644 --- a/kernel/lockdep.c +++ b/kernel/lockdep.c @@ -43,6 +43,7 @@ #include <linux/ftrace.h> #include <linux/stringify.h> #include <linux/bitops.h> + #include <asm/sections.h> #include "lockdep_internals.h" @@ -118,7 +119,7 @@ static inline int debug_locks_off_graph_unlock(void) static int lockdep_initialized; unsigned long nr_list_entries; -struct lock_list list_entries[MAX_LOCKDEP_ENTRIES]; +static struct lock_list list_entries[MAX_LOCKDEP_ENTRIES]; /* * All data structures here are protected by the global debug_lock. @@ -390,19 +391,6 @@ unsigned int nr_process_chains; unsigned int max_lockdep_depth; unsigned int max_recursion_depth; -static unsigned int lockdep_dependency_gen_id; - -static bool lockdep_dependency_visit(struct lock_class *source, - unsigned int depth) -{ - if (!depth) - lockdep_dependency_gen_id++; - if (source->dep_gen_id == lockdep_dependency_gen_id) - return true; - source->dep_gen_id = lockdep_dependency_gen_id; - return false; -} - #ifdef CONFIG_DEBUG_LOCKDEP /* * We cannot printk in early bootup code. Not even early_printk() @@ -551,88 +539,6 @@ static void lockdep_print_held_locks(struct task_struct *curr) } } -static void print_lock_class_header(struct lock_class *class, int depth) -{ - int bit; - - printk("%*s->", depth, ""); - print_lock_name(class); - printk(" ops: %lu", class->ops); - printk(" {\n"); - - for (bit = 0; bit < LOCK_USAGE_STATES; bit++) { - if (class->usage_mask & (1 << bit)) { - int len = depth; - - len += printk("%*s %s", depth, "", usage_str[bit]); - len += printk(" at:\n"); - print_stack_trace(class->usage_traces + bit, len); - } - } - printk("%*s }\n", depth, ""); - - printk("%*s ... key at: ",depth,""); - print_ip_sym((unsigned long)class->key); -} - -/* - * printk the shortest lock dependencies from @start to @end in reverse order: - */ -static void __used -print_shortest_lock_dependencies(struct lock_list *leaf, - struct lock_list *root) -{ - struct lock_list *entry = leaf; - int depth; - - /*compute depth from generated tree by BFS*/ - depth = get_lock_depth(leaf); - - do { - print_lock_class_header(entry->class, depth); - printk("%*s ... acquired at:\n", depth, ""); - print_stack_trace(&entry->trace, 2); - printk("\n"); - - if (depth == 0 && (entry != root)) { - printk("lockdep:%s bad BFS generated tree\n", __func__); - break; - } - - entry = get_lock_parent(entry); - depth--; - } while (entry && (depth >= 0)); - - return; -} -/* - * printk all lock dependencies starting at <entry>: - */ -static void __used -print_lock_dependencies(struct lock_class *class, int depth) -{ - struct lock_list *entry; - - if (lockdep_dependency_visit(class, depth)) - return; - - if (DEBUG_LOCKS_WARN_ON(depth >= 20)) - return; - - print_lock_class_header(class, depth); - - list_for_each_entry(entry, &class->locks_after, entry) { - if (DEBUG_LOCKS_WARN_ON(!entry->class)) - return; - - print_lock_dependencies(entry->class, depth + 1); - - printk("%*s ... acquired at:\n",depth,""); - print_stack_trace(&entry->trace, 2); - printk("\n"); - } -} - static void print_kernel_version(void) { printk("%s %.*s\n", init_utsname()->release, @@ -927,14 +833,106 @@ static int add_lock_to_list(struct lock_class *class, struct lock_class *this, return 1; } -unsigned long bfs_accessed[BITS_TO_LONGS(MAX_LOCKDEP_ENTRIES)]; -static struct circular_queue lock_cq; +/*For good efficiency of modular, we use power of 2*/ +#define MAX_CIRCULAR_QUEUE_SIZE 4096UL +#define CQ_MASK (MAX_CIRCULAR_QUEUE_SIZE-1) + +/* The circular_queue and helpers is used to implement the + * breadth-first search(BFS)algorithem, by which we can build + * the shortest path from the next lock to be acquired to the + * previous held lock if there is a circular between them. + * */ +struct circular_queue { + unsigned long element[MAX_CIRCULAR_QUEUE_SIZE]; + unsigned int front, rear; +}; + +static struct circular_queue lock_cq; +static unsigned long bfs_accessed[BITS_TO_LONGS(MAX_LOCKDEP_ENTRIES)]; + unsigned int max_bfs_queue_depth; + +static inline void __cq_init(struct circular_queue *cq) +{ + cq->front = cq->rear = 0; + bitmap_zero(bfs_accessed, MAX_LOCKDEP_ENTRIES); +} + +static inline int __cq_empty(struct circular_queue *cq) +{ + return (cq->front == cq->rear); +} + +static inline int __cq_full(struct circular_queue *cq) +{ + return ((cq->rear + 1) & CQ_MASK) == cq->front; +} + +static inline int __cq_enqueue(struct circular_queue *cq, unsigned long elem) +{ + if (__cq_full(cq)) + return -1; + + cq->element[cq->rear] = elem; + cq->rear = (cq->rear + 1) & CQ_MASK; + return 0; +} + +static inline int __cq_dequeue(struct circular_queue *cq, unsigned long *elem) +{ + if (__cq_empty(cq)) + return -1; + + *elem = cq->element[cq->front]; + cq->front = (cq->front + 1) & CQ_MASK; + return 0; +} + +static inline unsigned int __cq_get_elem_count(struct circular_queue *cq) +{ + return (cq->rear - cq->front) & CQ_MASK; +} + +static inline void mark_lock_accessed(struct lock_list *lock, + struct lock_list *parent) +{ + unsigned long nr; + nr = lock - list_entries; + WARN_ON(nr >= nr_list_entries); + lock->parent = parent; + set_bit(nr, bfs_accessed); +} + +static inline unsigned long lock_accessed(struct lock_list *lock) +{ + unsigned long nr; + nr = lock - list_entries; + WARN_ON(nr >= nr_list_entries); + return test_bit(nr, bfs_accessed); +} + +static inline struct lock_list *get_lock_parent(struct lock_list *child) +{ + return child->parent; +} + +static inline int get_lock_depth(struct lock_list *child) +{ + int depth = 0; + struct lock_list *parent; + + while ((parent = get_lock_parent(child))) { + child = parent; + depth++; + } + return depth; +} + static int __bfs(struct lock_list *source_entry, - void *data, - int (*match)(struct lock_list *entry, void *data), - struct lock_list **target_entry, - int forward) + void *data, + int (*match)(struct lock_list *entry, void *data), + struct lock_list **target_entry, + int forward) { struct lock_list *entry; struct list_head *head; @@ -1202,14 +1200,6 @@ check_noncircular(struct lock_list *root, struct lock_class *target, * without creating any illegal irq-safe -> irq-unsafe lock dependency. */ - -#define BFS_PROCESS_RET(ret) do { \ - if (ret < 0) \ - return print_bfs_bug(ret); \ - if (ret == 1) \ - return 1; \ - } while (0) - static inline int usage_match(struct lock_list *entry, void *bit) { return entry->class->usage_mask & (1 << (enum lock_usage_bit)bit); @@ -1263,6 +1253,60 @@ find_usage_backwards(struct lock_list *root, enum lock_usage_bit bit, return result; } +static void print_lock_class_header(struct lock_class *class, int depth) +{ + int bit; + + printk("%*s->", depth, ""); + print_lock_name(class); + printk(" ops: %lu", class->ops); + printk(" {\n"); + + for (bit = 0; bit < LOCK_USAGE_STATES; bit++) { + if (class->usage_mask & (1 << bit)) { + int len = depth; + + len += printk("%*s %s", depth, "", usage_str[bit]); + len += printk(" at:\n"); + print_stack_trace(class->usage_traces + bit, len); + } + } + printk("%*s }\n", depth, ""); + + printk("%*s ... key at: ",depth,""); + print_ip_sym((unsigned long)class->key); +} + +/* + * printk the shortest lock dependencies from @start to @end in reverse order: + */ +static void __used +print_shortest_lock_dependencies(struct lock_list *leaf, + struct lock_list *root) +{ + struct lock_list *entry = leaf; + int depth; + + /*compute depth from generated tree by BFS*/ + depth = get_lock_depth(leaf); + + do { + print_lock_class_header(entry->class, depth); + printk("%*s ... acquired at:\n", depth, ""); + print_stack_trace(&entry->trace, 2); + printk("\n"); + + if (depth == 0 && (entry != root)) { + printk("lockdep:%s bad BFS generated tree\n", __func__); + break; + } + + entry = get_lock_parent(entry); + depth--; + } while (entry && (depth >= 0)); + + return; +} static int print_bad_irq_dependency(struct task_struct *curr, @@ -1349,12 +1393,18 @@ check_usage(struct task_struct *curr, struct held_lock *prev, this.class = hlock_class(prev); ret = find_usage_backwards(&this, bit_backwards, &target_entry); - BFS_PROCESS_RET(ret); + if (ret < 0) + return print_bfs_bug(ret); + if (ret == 1) + return ret; that.parent = NULL; that.class = hlock_class(next); ret = find_usage_forwards(&that, bit_forwards, &target_entry1); - BFS_PROCESS_RET(ret); + if (ret < 0) + return print_bfs_bug(ret); + if (ret == 1) + return ret; return print_bad_irq_dependency(curr, &this, &that, target_entry, target_entry1, @@ -2038,7 +2088,10 @@ check_usage_forwards(struct task_struct *curr, struct held_lock *this, root.parent = NULL; root.class = hlock_class(this); ret = find_usage_forwards(&root, bit, &target_entry); - BFS_PROCESS_RET(ret); + if (ret < 0) + return print_bfs_bug(ret); + if (ret == 1) + return ret; return print_irq_inversion_bug(curr, &root, target_entry, this, 1, irqclass); @@ -2059,7 +2112,10 @@ check_usage_backwards(struct task_struct *curr, struct held_lock *this, root.parent = NULL; root.class = hlock_class(this); ret = find_usage_backwards(&root, bit, &target_entry); - BFS_PROCESS_RET(ret); + if (ret < 0) + return print_bfs_bug(ret); + if (ret == 1) + return ret; return print_irq_inversion_bug(curr, &root, target_entry, this, 1, irqclass); diff --git a/kernel/lockdep_internals.h b/kernel/lockdep_internals.h index 6baa8807efd..a2ee95ad131 100644 --- a/kernel/lockdep_internals.h +++ b/kernel/lockdep_internals.h @@ -91,6 +91,8 @@ extern unsigned int nr_process_chains; extern unsigned int max_lockdep_depth; extern unsigned int max_recursion_depth; +extern unsigned int max_bfs_queue_depth; + #ifdef CONFIG_PROVE_LOCKING extern unsigned long lockdep_count_forward_deps(struct lock_class *); extern unsigned long lockdep_count_backward_deps(struct lock_class *); @@ -136,98 +138,3 @@ extern atomic_t nr_find_usage_backwards_recursions; # define debug_atomic_dec(ptr) do { } while (0) # define debug_atomic_read(ptr) 0 #endif - - -extern unsigned int max_bfs_queue_depth; -extern unsigned long nr_list_entries; -extern struct lock_list list_entries[MAX_LOCKDEP_ENTRIES]; -extern unsigned long bfs_accessed[]; - -/*For good efficiency of modular, we use power of 2*/ -#define MAX_CIRCULAR_QUE_SIZE 4096UL - -/* The circular_queue and helpers is used to implement the - * breadth-first search(BFS)algorithem, by which we can build - * the shortest path from the next lock to be acquired to the - * previous held lock if there is a circular between them. - * */ -struct circular_queue{ - unsigned long element[MAX_CIRCULAR_QUE_SIZE]; - unsigned int front, rear; -}; - -static inline void __cq_init(struct circular_queue *cq) -{ - cq->front = cq->rear = 0; - bitmap_zero(bfs_accessed, MAX_LOCKDEP_ENTRIES); -} - -static inline int __cq_empty(struct circular_queue *cq) -{ - return (cq->front == cq->rear); -} - -static inline int __cq_full(struct circular_queue *cq) -{ - return ((cq->rear + 1)&(MAX_CIRCULAR_QUE_SIZE-1)) == cq->front; -} - -static inline int __cq_enqueue(struct circular_queue *cq, unsigned long elem) -{ - if (__cq_full(cq)) - return -1; - - cq->element[cq->rear] = elem; - cq->rear = (cq->rear + 1)&(MAX_CIRCULAR_QUE_SIZE-1); - return 0; -} - -static inline int __cq_dequeue(struct circular_queue *cq, unsigned long *elem) -{ - if (__cq_empty(cq)) - return -1; - - *elem = cq->element[cq->front]; - cq->front = (cq->front + 1)&(MAX_CIRCULAR_QUE_SIZE-1); - return 0; -} - -static inline unsigned int __cq_get_elem_count(struct circular_queue *cq) -{ - return (cq->rear - cq->front)&(MAX_CIRCULAR_QUE_SIZE-1); -} - -static inline void mark_lock_accessed(struct lock_list *lock, - struct lock_list *parent) -{ - unsigned long nr; - nr = lock - list_entries; - WARN_ON(nr >= nr_list_entries); - lock->parent = parent; - set_bit(nr, bfs_accessed); -} - -static inline unsigned long lock_accessed(struct lock_list *lock) -{ - unsigned long nr; - nr = lock - list_entries; - WARN_ON(nr >= nr_list_entries); - return test_bit(nr, bfs_accessed); -} - -static inline struct lock_list *get_lock_parent(struct lock_list *child) -{ - return child->parent; -} - -static inline int get_lock_depth(struct lock_list *child) -{ - int depth = 0; - struct lock_list *parent; - - while ((parent = get_lock_parent(child))) { - child = parent; - depth++; - } - return depth; -} |