HID: hiddev: Fix slab-out-of-bounds write in hiddev_ioctl_usage()
[linux/fpc-iii.git] / tools / lib / lockdep / preload.c
blob21cdf869a01b8b7facc084c4dc66cf73afa163bb
1 #define _GNU_SOURCE
2 #include <pthread.h>
3 #include <stdio.h>
4 #include <dlfcn.h>
5 #include <stdlib.h>
6 #include <sysexits.h>
7 #include "include/liblockdep/mutex.h"
8 #include "../../include/linux/rbtree.h"
10 /**
11 * struct lock_lookup - liblockdep's view of a single unique lock
12 * @orig: pointer to the original pthread lock, used for lookups
13 * @dep_map: lockdep's dep_map structure
14 * @key: lockdep's key structure
15 * @node: rb-tree node used to store the lock in a global tree
16 * @name: a unique name for the lock
18 struct lock_lookup {
19 void *orig; /* Original pthread lock, used for lookups */
20 struct lockdep_map dep_map; /* Since all locks are dynamic, we need
21 * a dep_map and a key for each lock */
23 * Wait, there's no support for key classes? Yup :(
24 * Most big projects wrap the pthread api with their own calls to
25 * be compatible with different locking methods. This means that
26 * "classes" will be brokes since the function that creates all
27 * locks will point to a generic locking function instead of the
28 * actual code that wants to do the locking.
30 struct lock_class_key key;
31 struct rb_node node;
32 #define LIBLOCKDEP_MAX_LOCK_NAME 22
33 char name[LIBLOCKDEP_MAX_LOCK_NAME];
36 /* This is where we store our locks */
37 static struct rb_root locks = RB_ROOT;
38 static pthread_rwlock_t locks_rwlock = PTHREAD_RWLOCK_INITIALIZER;
40 /* pthread mutex API */
42 #ifdef __GLIBC__
43 extern int __pthread_mutex_init(pthread_mutex_t *mutex, const pthread_mutexattr_t *attr);
44 extern int __pthread_mutex_lock(pthread_mutex_t *mutex);
45 extern int __pthread_mutex_trylock(pthread_mutex_t *mutex);
46 extern int __pthread_mutex_unlock(pthread_mutex_t *mutex);
47 extern int __pthread_mutex_destroy(pthread_mutex_t *mutex);
48 #else
49 #define __pthread_mutex_init NULL
50 #define __pthread_mutex_lock NULL
51 #define __pthread_mutex_trylock NULL
52 #define __pthread_mutex_unlock NULL
53 #define __pthread_mutex_destroy NULL
54 #endif
55 static int (*ll_pthread_mutex_init)(pthread_mutex_t *mutex,
56 const pthread_mutexattr_t *attr) = __pthread_mutex_init;
57 static int (*ll_pthread_mutex_lock)(pthread_mutex_t *mutex) = __pthread_mutex_lock;
58 static int (*ll_pthread_mutex_trylock)(pthread_mutex_t *mutex) = __pthread_mutex_trylock;
59 static int (*ll_pthread_mutex_unlock)(pthread_mutex_t *mutex) = __pthread_mutex_unlock;
60 static int (*ll_pthread_mutex_destroy)(pthread_mutex_t *mutex) = __pthread_mutex_destroy;
62 /* pthread rwlock API */
64 #ifdef __GLIBC__
65 extern int __pthread_rwlock_init(pthread_rwlock_t *rwlock, const pthread_rwlockattr_t *attr);
66 extern int __pthread_rwlock_destroy(pthread_rwlock_t *rwlock);
67 extern int __pthread_rwlock_wrlock(pthread_rwlock_t *rwlock);
68 extern int __pthread_rwlock_trywrlock(pthread_rwlock_t *rwlock);
69 extern int __pthread_rwlock_rdlock(pthread_rwlock_t *rwlock);
70 extern int __pthread_rwlock_tryrdlock(pthread_rwlock_t *rwlock);
71 extern int __pthread_rwlock_unlock(pthread_rwlock_t *rwlock);
72 #else
73 #define __pthread_rwlock_init NULL
74 #define __pthread_rwlock_destroy NULL
75 #define __pthread_rwlock_wrlock NULL
76 #define __pthread_rwlock_trywrlock NULL
77 #define __pthread_rwlock_rdlock NULL
78 #define __pthread_rwlock_tryrdlock NULL
79 #define __pthread_rwlock_unlock NULL
80 #endif
82 static int (*ll_pthread_rwlock_init)(pthread_rwlock_t *rwlock,
83 const pthread_rwlockattr_t *attr) = __pthread_rwlock_init;
84 static int (*ll_pthread_rwlock_destroy)(pthread_rwlock_t *rwlock) = __pthread_rwlock_destroy;
85 static int (*ll_pthread_rwlock_rdlock)(pthread_rwlock_t *rwlock) = __pthread_rwlock_rdlock;
86 static int (*ll_pthread_rwlock_tryrdlock)(pthread_rwlock_t *rwlock) = __pthread_rwlock_tryrdlock;
87 static int (*ll_pthread_rwlock_trywrlock)(pthread_rwlock_t *rwlock) = __pthread_rwlock_trywrlock;
88 static int (*ll_pthread_rwlock_wrlock)(pthread_rwlock_t *rwlock) = __pthread_rwlock_wrlock;
89 static int (*ll_pthread_rwlock_unlock)(pthread_rwlock_t *rwlock) = __pthread_rwlock_unlock;
91 enum { none, prepare, done, } __init_state;
92 static void init_preload(void);
93 static void try_init_preload(void)
95 if (__init_state != done)
96 init_preload();
99 static struct rb_node **__get_lock_node(void *lock, struct rb_node **parent)
101 struct rb_node **node = &locks.rb_node;
102 struct lock_lookup *l;
104 *parent = NULL;
106 while (*node) {
107 l = rb_entry(*node, struct lock_lookup, node);
109 *parent = *node;
110 if (lock < l->orig)
111 node = &l->node.rb_left;
112 else if (lock > l->orig)
113 node = &l->node.rb_right;
114 else
115 return node;
118 return node;
121 #ifndef LIBLOCKDEP_STATIC_ENTRIES
122 #define LIBLOCKDEP_STATIC_ENTRIES 1024
123 #endif
125 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
127 static struct lock_lookup __locks[LIBLOCKDEP_STATIC_ENTRIES];
128 static int __locks_nr;
130 static inline bool is_static_lock(struct lock_lookup *lock)
132 return lock >= __locks && lock < __locks + ARRAY_SIZE(__locks);
135 static struct lock_lookup *alloc_lock(void)
137 if (__init_state != done) {
139 * Some programs attempt to initialize and use locks in their
140 * allocation path. This means that a call to malloc() would
141 * result in locks being initialized and locked.
143 * Why is it an issue for us? dlsym() below will try allocating
144 * to give us the original function. Since this allocation will
145 * result in a locking operations, we have to let pthread deal
146 * with it, but we can't! we don't have the pointer to the
147 * original API since we're inside dlsym() trying to get it
150 int idx = __locks_nr++;
151 if (idx >= ARRAY_SIZE(__locks)) {
152 fprintf(stderr,
153 "LOCKDEP error: insufficient LIBLOCKDEP_STATIC_ENTRIES\n");
154 exit(EX_UNAVAILABLE);
156 return __locks + idx;
159 return malloc(sizeof(struct lock_lookup));
162 static inline void free_lock(struct lock_lookup *lock)
164 if (likely(!is_static_lock(lock)))
165 free(lock);
169 * __get_lock - find or create a lock instance
170 * @lock: pointer to a pthread lock function
172 * Try to find an existing lock in the rbtree using the provided pointer. If
173 * one wasn't found - create it.
175 static struct lock_lookup *__get_lock(void *lock)
177 struct rb_node **node, *parent;
178 struct lock_lookup *l;
180 ll_pthread_rwlock_rdlock(&locks_rwlock);
181 node = __get_lock_node(lock, &parent);
182 ll_pthread_rwlock_unlock(&locks_rwlock);
183 if (*node) {
184 return rb_entry(*node, struct lock_lookup, node);
187 /* We didn't find the lock, let's create it */
188 l = alloc_lock();
189 if (l == NULL)
190 return NULL;
192 l->orig = lock;
194 * Currently the name of the lock is the ptr value of the pthread lock,
195 * while not optimal, it makes debugging a bit easier.
197 * TODO: Get the real name of the lock using libdwarf
199 sprintf(l->name, "%p", lock);
200 lockdep_init_map(&l->dep_map, l->name, &l->key, 0);
202 ll_pthread_rwlock_wrlock(&locks_rwlock);
203 /* This might have changed since the last time we fetched it */
204 node = __get_lock_node(lock, &parent);
205 rb_link_node(&l->node, parent, node);
206 rb_insert_color(&l->node, &locks);
207 ll_pthread_rwlock_unlock(&locks_rwlock);
209 return l;
212 static void __del_lock(struct lock_lookup *lock)
214 ll_pthread_rwlock_wrlock(&locks_rwlock);
215 rb_erase(&lock->node, &locks);
216 ll_pthread_rwlock_unlock(&locks_rwlock);
217 free_lock(lock);
220 int pthread_mutex_init(pthread_mutex_t *mutex,
221 const pthread_mutexattr_t *attr)
223 int r;
226 * We keep trying to init our preload module because there might be
227 * code in init sections that tries to touch locks before we are
228 * initialized, in that case we'll need to manually call preload
229 * to get us going.
231 * Funny enough, kernel's lockdep had the same issue, and used
232 * (almost) the same solution. See look_up_lock_class() in
233 * kernel/locking/lockdep.c for details.
235 try_init_preload();
237 r = ll_pthread_mutex_init(mutex, attr);
238 if (r == 0)
240 * We do a dummy initialization here so that lockdep could
241 * warn us if something fishy is going on - such as
242 * initializing a held lock.
244 __get_lock(mutex);
246 return r;
249 int pthread_mutex_lock(pthread_mutex_t *mutex)
251 int r;
253 try_init_preload();
255 lock_acquire(&__get_lock(mutex)->dep_map, 0, 0, 0, 1, NULL,
256 (unsigned long)_RET_IP_);
258 * Here's the thing with pthread mutexes: unlike the kernel variant,
259 * they can fail.
261 * This means that the behaviour here is a bit different from what's
262 * going on in the kernel: there we just tell lockdep that we took the
263 * lock before actually taking it, but here we must deal with the case
264 * that locking failed.
266 * To do that we'll "release" the lock if locking failed - this way
267 * we'll get lockdep doing the correct checks when we try to take
268 * the lock, and if that fails - we'll be back to the correct
269 * state by releasing it.
271 r = ll_pthread_mutex_lock(mutex);
272 if (r)
273 lock_release(&__get_lock(mutex)->dep_map, 0, (unsigned long)_RET_IP_);
275 return r;
278 int pthread_mutex_trylock(pthread_mutex_t *mutex)
280 int r;
282 try_init_preload();
284 lock_acquire(&__get_lock(mutex)->dep_map, 0, 1, 0, 1, NULL, (unsigned long)_RET_IP_);
285 r = ll_pthread_mutex_trylock(mutex);
286 if (r)
287 lock_release(&__get_lock(mutex)->dep_map, 0, (unsigned long)_RET_IP_);
289 return r;
292 int pthread_mutex_unlock(pthread_mutex_t *mutex)
294 int r;
296 try_init_preload();
298 lock_release(&__get_lock(mutex)->dep_map, 0, (unsigned long)_RET_IP_);
300 * Just like taking a lock, only in reverse!
302 * If we fail releasing the lock, tell lockdep we're holding it again.
304 r = ll_pthread_mutex_unlock(mutex);
305 if (r)
306 lock_acquire(&__get_lock(mutex)->dep_map, 0, 0, 0, 1, NULL, (unsigned long)_RET_IP_);
308 return r;
311 int pthread_mutex_destroy(pthread_mutex_t *mutex)
313 try_init_preload();
316 * Let's see if we're releasing a lock that's held.
318 * TODO: Hook into free() and add that check there as well.
320 debug_check_no_locks_freed(mutex, sizeof(*mutex));
321 __del_lock(__get_lock(mutex));
322 return ll_pthread_mutex_destroy(mutex);
325 /* This is the rwlock part, very similar to what happened with mutex above */
326 int pthread_rwlock_init(pthread_rwlock_t *rwlock,
327 const pthread_rwlockattr_t *attr)
329 int r;
331 try_init_preload();
333 r = ll_pthread_rwlock_init(rwlock, attr);
334 if (r == 0)
335 __get_lock(rwlock);
337 return r;
340 int pthread_rwlock_destroy(pthread_rwlock_t *rwlock)
342 try_init_preload();
344 debug_check_no_locks_freed(rwlock, sizeof(*rwlock));
345 __del_lock(__get_lock(rwlock));
346 return ll_pthread_rwlock_destroy(rwlock);
349 int pthread_rwlock_rdlock(pthread_rwlock_t *rwlock)
351 int r;
353 init_preload();
355 lock_acquire(&__get_lock(rwlock)->dep_map, 0, 0, 2, 1, NULL, (unsigned long)_RET_IP_);
356 r = ll_pthread_rwlock_rdlock(rwlock);
357 if (r)
358 lock_release(&__get_lock(rwlock)->dep_map, 0, (unsigned long)_RET_IP_);
360 return r;
363 int pthread_rwlock_tryrdlock(pthread_rwlock_t *rwlock)
365 int r;
367 init_preload();
369 lock_acquire(&__get_lock(rwlock)->dep_map, 0, 1, 2, 1, NULL, (unsigned long)_RET_IP_);
370 r = ll_pthread_rwlock_tryrdlock(rwlock);
371 if (r)
372 lock_release(&__get_lock(rwlock)->dep_map, 0, (unsigned long)_RET_IP_);
374 return r;
377 int pthread_rwlock_trywrlock(pthread_rwlock_t *rwlock)
379 int r;
381 init_preload();
383 lock_acquire(&__get_lock(rwlock)->dep_map, 0, 1, 0, 1, NULL, (unsigned long)_RET_IP_);
384 r = ll_pthread_rwlock_trywrlock(rwlock);
385 if (r)
386 lock_release(&__get_lock(rwlock)->dep_map, 0, (unsigned long)_RET_IP_);
388 return r;
391 int pthread_rwlock_wrlock(pthread_rwlock_t *rwlock)
393 int r;
395 init_preload();
397 lock_acquire(&__get_lock(rwlock)->dep_map, 0, 0, 0, 1, NULL, (unsigned long)_RET_IP_);
398 r = ll_pthread_rwlock_wrlock(rwlock);
399 if (r)
400 lock_release(&__get_lock(rwlock)->dep_map, 0, (unsigned long)_RET_IP_);
402 return r;
405 int pthread_rwlock_unlock(pthread_rwlock_t *rwlock)
407 int r;
409 init_preload();
411 lock_release(&__get_lock(rwlock)->dep_map, 0, (unsigned long)_RET_IP_);
412 r = ll_pthread_rwlock_unlock(rwlock);
413 if (r)
414 lock_acquire(&__get_lock(rwlock)->dep_map, 0, 0, 0, 1, NULL, (unsigned long)_RET_IP_);
416 return r;
419 __attribute__((constructor)) static void init_preload(void)
421 if (__init_state == done)
422 return;
424 #ifndef __GLIBC__
425 __init_state = prepare;
427 ll_pthread_mutex_init = dlsym(RTLD_NEXT, "pthread_mutex_init");
428 ll_pthread_mutex_lock = dlsym(RTLD_NEXT, "pthread_mutex_lock");
429 ll_pthread_mutex_trylock = dlsym(RTLD_NEXT, "pthread_mutex_trylock");
430 ll_pthread_mutex_unlock = dlsym(RTLD_NEXT, "pthread_mutex_unlock");
431 ll_pthread_mutex_destroy = dlsym(RTLD_NEXT, "pthread_mutex_destroy");
433 ll_pthread_rwlock_init = dlsym(RTLD_NEXT, "pthread_rwlock_init");
434 ll_pthread_rwlock_destroy = dlsym(RTLD_NEXT, "pthread_rwlock_destroy");
435 ll_pthread_rwlock_rdlock = dlsym(RTLD_NEXT, "pthread_rwlock_rdlock");
436 ll_pthread_rwlock_tryrdlock = dlsym(RTLD_NEXT, "pthread_rwlock_tryrdlock");
437 ll_pthread_rwlock_wrlock = dlsym(RTLD_NEXT, "pthread_rwlock_wrlock");
438 ll_pthread_rwlock_trywrlock = dlsym(RTLD_NEXT, "pthread_rwlock_trywrlock");
439 ll_pthread_rwlock_unlock = dlsym(RTLD_NEXT, "pthread_rwlock_unlock");
440 #endif
442 lockdep_init();
444 __init_state = done;