]>
Commit | Line | Data |
---|---|---|
fb1c8f93 IM |
1 | /* |
2 | * Copyright 2005, Red Hat, Inc., Ingo Molnar | |
3 | * Released under the General Public License (GPL). | |
4 | * | |
5 | * This file contains the spinlock/rwlock implementations for | |
6 | * DEBUG_SPINLOCK. | |
7 | */ | |
8 | ||
9 | #include <linux/config.h> | |
10 | #include <linux/spinlock.h> | |
11 | #include <linux/interrupt.h> | |
12 | #include <linux/delay.h> | |
13 | ||
14 | static void spin_bug(spinlock_t *lock, const char *msg) | |
15 | { | |
16 | static long print_once = 1; | |
17 | struct task_struct *owner = NULL; | |
18 | ||
19 | if (xchg(&print_once, 0)) { | |
20 | if (lock->owner && lock->owner != SPINLOCK_OWNER_INIT) | |
21 | owner = lock->owner; | |
22 | printk("BUG: spinlock %s on CPU#%d, %s/%d\n", | |
23 | msg, smp_processor_id(), current->comm, current->pid); | |
24 | printk(" lock: %p, .magic: %08x, .owner: %s/%d, .owner_cpu: %d\n", | |
25 | lock, lock->magic, | |
26 | owner ? owner->comm : "<none>", | |
27 | owner ? owner->pid : -1, | |
28 | lock->owner_cpu); | |
29 | dump_stack(); | |
30 | #ifdef CONFIG_SMP | |
31 | /* | |
32 | * We cannot continue on SMP: | |
33 | */ | |
34 | // panic("bad locking"); | |
35 | #endif | |
36 | } | |
37 | } | |
38 | ||
39 | #define SPIN_BUG_ON(cond, lock, msg) if (unlikely(cond)) spin_bug(lock, msg) | |
40 | ||
41 | static inline void debug_spin_lock_before(spinlock_t *lock) | |
42 | { | |
43 | SPIN_BUG_ON(lock->magic != SPINLOCK_MAGIC, lock, "bad magic"); | |
44 | SPIN_BUG_ON(lock->owner == current, lock, "recursion"); | |
45 | SPIN_BUG_ON(lock->owner_cpu == raw_smp_processor_id(), | |
46 | lock, "cpu recursion"); | |
47 | } | |
48 | ||
49 | static inline void debug_spin_lock_after(spinlock_t *lock) | |
50 | { | |
51 | lock->owner_cpu = raw_smp_processor_id(); | |
52 | lock->owner = current; | |
53 | } | |
54 | ||
55 | static inline void debug_spin_unlock(spinlock_t *lock) | |
56 | { | |
57 | SPIN_BUG_ON(lock->magic != SPINLOCK_MAGIC, lock, "bad magic"); | |
58 | SPIN_BUG_ON(!spin_is_locked(lock), lock, "already unlocked"); | |
59 | SPIN_BUG_ON(lock->owner != current, lock, "wrong owner"); | |
60 | SPIN_BUG_ON(lock->owner_cpu != raw_smp_processor_id(), | |
61 | lock, "wrong CPU"); | |
62 | lock->owner = SPINLOCK_OWNER_INIT; | |
63 | lock->owner_cpu = -1; | |
64 | } | |
65 | ||
66 | static void __spin_lock_debug(spinlock_t *lock) | |
67 | { | |
68 | int print_once = 1; | |
69 | u64 i; | |
70 | ||
71 | for (;;) { | |
72 | for (i = 0; i < loops_per_jiffy * HZ; i++) { | |
73 | cpu_relax(); | |
74 | if (__raw_spin_trylock(&lock->raw_lock)) | |
75 | return; | |
76 | } | |
77 | /* lockup suspected: */ | |
78 | if (print_once) { | |
79 | print_once = 0; | |
80 | printk("BUG: spinlock lockup on CPU#%d, %s/%d, %p\n", | |
81 | smp_processor_id(), current->comm, current->pid, | |
82 | lock); | |
83 | dump_stack(); | |
84 | } | |
85 | } | |
86 | } | |
87 | ||
88 | void _raw_spin_lock(spinlock_t *lock) | |
89 | { | |
90 | debug_spin_lock_before(lock); | |
91 | if (unlikely(!__raw_spin_trylock(&lock->raw_lock))) | |
92 | __spin_lock_debug(lock); | |
93 | debug_spin_lock_after(lock); | |
94 | } | |
95 | ||
96 | int _raw_spin_trylock(spinlock_t *lock) | |
97 | { | |
98 | int ret = __raw_spin_trylock(&lock->raw_lock); | |
99 | ||
100 | if (ret) | |
101 | debug_spin_lock_after(lock); | |
102 | #ifndef CONFIG_SMP | |
103 | /* | |
104 | * Must not happen on UP: | |
105 | */ | |
106 | SPIN_BUG_ON(!ret, lock, "trylock failure on UP"); | |
107 | #endif | |
108 | return ret; | |
109 | } | |
110 | ||
111 | void _raw_spin_unlock(spinlock_t *lock) | |
112 | { | |
113 | debug_spin_unlock(lock); | |
114 | __raw_spin_unlock(&lock->raw_lock); | |
115 | } | |
116 | ||
117 | static void rwlock_bug(rwlock_t *lock, const char *msg) | |
118 | { | |
119 | static long print_once = 1; | |
120 | ||
121 | if (xchg(&print_once, 0)) { | |
122 | printk("BUG: rwlock %s on CPU#%d, %s/%d, %p\n", msg, | |
123 | smp_processor_id(), current->comm, current->pid, lock); | |
124 | dump_stack(); | |
125 | #ifdef CONFIG_SMP | |
126 | /* | |
127 | * We cannot continue on SMP: | |
128 | */ | |
129 | panic("bad locking"); | |
130 | #endif | |
131 | } | |
132 | } | |
133 | ||
134 | #define RWLOCK_BUG_ON(cond, lock, msg) if (unlikely(cond)) rwlock_bug(lock, msg) | |
135 | ||
136 | static void __read_lock_debug(rwlock_t *lock) | |
137 | { | |
138 | int print_once = 1; | |
139 | u64 i; | |
140 | ||
141 | for (;;) { | |
142 | for (i = 0; i < loops_per_jiffy * HZ; i++) { | |
143 | cpu_relax(); | |
144 | if (__raw_read_trylock(&lock->raw_lock)) | |
145 | return; | |
146 | } | |
147 | /* lockup suspected: */ | |
148 | if (print_once) { | |
149 | print_once = 0; | |
150 | printk("BUG: read-lock lockup on CPU#%d, %s/%d, %p\n", | |
151 | smp_processor_id(), current->comm, current->pid, | |
152 | lock); | |
153 | dump_stack(); | |
154 | } | |
155 | } | |
156 | } | |
157 | ||
158 | void _raw_read_lock(rwlock_t *lock) | |
159 | { | |
160 | RWLOCK_BUG_ON(lock->magic != RWLOCK_MAGIC, lock, "bad magic"); | |
161 | if (unlikely(!__raw_read_trylock(&lock->raw_lock))) | |
162 | __read_lock_debug(lock); | |
163 | } | |
164 | ||
165 | int _raw_read_trylock(rwlock_t *lock) | |
166 | { | |
167 | int ret = __raw_read_trylock(&lock->raw_lock); | |
168 | ||
169 | #ifndef CONFIG_SMP | |
170 | /* | |
171 | * Must not happen on UP: | |
172 | */ | |
173 | RWLOCK_BUG_ON(!ret, lock, "trylock failure on UP"); | |
174 | #endif | |
175 | return ret; | |
176 | } | |
177 | ||
178 | void _raw_read_unlock(rwlock_t *lock) | |
179 | { | |
180 | RWLOCK_BUG_ON(lock->magic != RWLOCK_MAGIC, lock, "bad magic"); | |
181 | __raw_read_unlock(&lock->raw_lock); | |
182 | } | |
183 | ||
184 | static inline void debug_write_lock_before(rwlock_t *lock) | |
185 | { | |
186 | RWLOCK_BUG_ON(lock->magic != RWLOCK_MAGIC, lock, "bad magic"); | |
187 | RWLOCK_BUG_ON(lock->owner == current, lock, "recursion"); | |
188 | RWLOCK_BUG_ON(lock->owner_cpu == raw_smp_processor_id(), | |
189 | lock, "cpu recursion"); | |
190 | } | |
191 | ||
192 | static inline void debug_write_lock_after(rwlock_t *lock) | |
193 | { | |
194 | lock->owner_cpu = raw_smp_processor_id(); | |
195 | lock->owner = current; | |
196 | } | |
197 | ||
198 | static inline void debug_write_unlock(rwlock_t *lock) | |
199 | { | |
200 | RWLOCK_BUG_ON(lock->magic != RWLOCK_MAGIC, lock, "bad magic"); | |
201 | RWLOCK_BUG_ON(lock->owner != current, lock, "wrong owner"); | |
202 | RWLOCK_BUG_ON(lock->owner_cpu != raw_smp_processor_id(), | |
203 | lock, "wrong CPU"); | |
204 | lock->owner = SPINLOCK_OWNER_INIT; | |
205 | lock->owner_cpu = -1; | |
206 | } | |
207 | ||
208 | static void __write_lock_debug(rwlock_t *lock) | |
209 | { | |
210 | int print_once = 1; | |
211 | u64 i; | |
212 | ||
213 | for (;;) { | |
214 | for (i = 0; i < loops_per_jiffy * HZ; i++) { | |
215 | cpu_relax(); | |
216 | if (__raw_write_trylock(&lock->raw_lock)) | |
217 | return; | |
218 | } | |
219 | /* lockup suspected: */ | |
220 | if (print_once) { | |
221 | print_once = 0; | |
222 | printk("BUG: write-lock lockup on CPU#%d, %s/%d, %p\n", | |
223 | smp_processor_id(), current->comm, current->pid, | |
224 | lock); | |
225 | dump_stack(); | |
226 | } | |
227 | } | |
228 | } | |
229 | ||
230 | void _raw_write_lock(rwlock_t *lock) | |
231 | { | |
232 | debug_write_lock_before(lock); | |
233 | if (unlikely(!__raw_write_trylock(&lock->raw_lock))) | |
234 | __write_lock_debug(lock); | |
235 | debug_write_lock_after(lock); | |
236 | } | |
237 | ||
238 | int _raw_write_trylock(rwlock_t *lock) | |
239 | { | |
240 | int ret = __raw_write_trylock(&lock->raw_lock); | |
241 | ||
242 | if (ret) | |
243 | debug_write_lock_after(lock); | |
244 | #ifndef CONFIG_SMP | |
245 | /* | |
246 | * Must not happen on UP: | |
247 | */ | |
248 | RWLOCK_BUG_ON(!ret, lock, "trylock failure on UP"); | |
249 | #endif | |
250 | return ret; | |
251 | } | |
252 | ||
253 | void _raw_write_unlock(rwlock_t *lock) | |
254 | { | |
255 | debug_write_unlock(lock); | |
256 | __raw_write_unlock(&lock->raw_lock); | |
257 | } |