Commit | Line | Data |
---|---|---|
b27f8e75 | 1 | /* |
c0c0989a | 2 | * SPDX-License-Identifier: LGPL-2.1-or-later |
c39c72ee | 3 | * |
c0c0989a MJ |
4 | * Copyright (C) 2009 Pierre-Marc Fournier |
5 | * Copyright (C) 2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | |
c39c72ee PMF |
6 | */ |
7 | ||
d7e89462 MD |
8 | /* |
9 | * Do _not_ define _LGPL_SOURCE because we don't want to create a | |
10 | * circular dependency loop between this malloc wrapper, liburcu and | |
11 | * libc. | |
12 | */ | |
9d315d6d MJ |
13 | |
14 | /* Has to be included first to override dlfcn.h */ | |
15 | #include <common/compat/dlfcn.h> | |
16 | ||
e541a28d PMF |
17 | #include <sys/types.h> |
18 | #include <stdio.h> | |
2594a5b4 | 19 | #include <assert.h> |
4b4a1337 MJ |
20 | #include <malloc.h> |
21 | ||
4c3536e0 MD |
22 | #include <urcu/system.h> |
23 | #include <urcu/uatomic.h> | |
2594a5b4 | 24 | #include <urcu/compiler.h> |
20ef5166 | 25 | #include <urcu/arch.h> |
4b4a1337 MJ |
26 | |
27 | #include <lttng/ust-libc-wrapper.h> | |
28 | ||
9d315d6d MJ |
29 | #include "common/macros.h" |
30 | #include "common/align.h" | |
1622ba22 | 31 | |
6ba0c2b2 MD |
32 | #define LTTNG_UST_TRACEPOINT_HIDDEN_DEFINITION |
33 | #define LTTNG_UST_TRACEPOINT_PROVIDER_HIDDEN_DEFINITION | |
34 | ||
88c7c4ea | 35 | #define LTTNG_UST_TRACEPOINT_DEFINE |
660323e6 | 36 | #define LTTNG_UST_TRACEPOINT_CREATE_PROBES |
c28c4a88 | 37 | #define LTTNG_UST_TP_IP_PARAM ip |
1622ba22 | 38 | #include "ust_libc.h" |
fbd8191b | 39 | |
f95b2888 SS |
40 | #define STATIC_CALLOC_LEN 4096 |
41 | static char static_calloc_buf[STATIC_CALLOC_LEN]; | |
4c3536e0 | 42 | static unsigned long static_calloc_buf_offset; |
f95b2888 | 43 | |
2594a5b4 MD |
44 | struct alloc_functions { |
45 | void *(*calloc)(size_t nmemb, size_t size); | |
46 | void *(*malloc)(size_t size); | |
47 | void (*free)(void *ptr); | |
48 | void *(*realloc)(void *ptr, size_t size); | |
49 | void *(*memalign)(size_t alignment, size_t size); | |
50 | int (*posix_memalign)(void **memptr, size_t alignment, size_t size); | |
51 | }; | |
52 | ||
53 | static | |
54 | struct alloc_functions cur_alloc; | |
55 | ||
8c06ba6f MD |
56 | /* |
57 | * Make sure our own use of the LTS compat layer will not cause infinite | |
58 | * recursion by calling calloc. | |
59 | */ | |
60 | ||
61 | static | |
62 | void *static_calloc(size_t nmemb, size_t size); | |
63 | ||
20ef5166 MD |
64 | /* |
65 | * pthread mutex replacement for URCU tls compat layer. | |
66 | */ | |
67 | static int ust_malloc_lock; | |
68 | ||
8da9deee MJ |
69 | static |
70 | void ust_malloc_spin_lock(pthread_mutex_t *lock) | |
71 | __attribute__((unused)); | |
72 | static | |
2208d8b5 | 73 | void ust_malloc_spin_lock(pthread_mutex_t *lock __attribute__((unused))) |
20ef5166 MD |
74 | { |
75 | /* | |
76 | * The memory barrier within cmpxchg takes care of ordering | |
77 | * memory accesses with respect to the start of the critical | |
78 | * section. | |
79 | */ | |
80 | while (uatomic_cmpxchg(&ust_malloc_lock, 0, 1) != 0) | |
81 | caa_cpu_relax(); | |
82 | } | |
83 | ||
8da9deee MJ |
84 | static |
85 | void ust_malloc_spin_unlock(pthread_mutex_t *lock) | |
86 | __attribute__((unused)); | |
87 | static | |
2208d8b5 | 88 | void ust_malloc_spin_unlock(pthread_mutex_t *lock __attribute__((unused))) |
20ef5166 MD |
89 | { |
90 | /* | |
91 | * Ensure memory accesses within the critical section do not | |
92 | * leak outside. | |
93 | */ | |
94 | cmm_smp_mb(); | |
95 | uatomic_set(&ust_malloc_lock, 0); | |
96 | } | |
97 | ||
49400d96 MD |
98 | /* |
99 | * Use initial-exec TLS model for the malloc_nesting nesting guard | |
100 | * variable to ensure that the glibc implementation of the TLS access | |
101 | * don't trigger infinite recursion by calling the memory allocator | |
102 | * wrapper functions, which could happen with global-dynamic. | |
103 | */ | |
104 | static __thread __attribute__((tls_model("initial-exec"))) int malloc_nesting; | |
8c06ba6f | 105 | |
2594a5b4 MD |
106 | /* |
107 | * Static allocator to use when initially executing dlsym(). It keeps a | |
108 | * size_t value of each object size prior to the object. | |
109 | */ | |
110 | static | |
111 | void *static_calloc_aligned(size_t nmemb, size_t size, size_t alignment) | |
f95b2888 | 112 | { |
2594a5b4 MD |
113 | size_t prev_offset, new_offset, res_offset, aligned_offset; |
114 | ||
115 | if (nmemb * size == 0) { | |
116 | return NULL; | |
117 | } | |
f95b2888 | 118 | |
4c3536e0 MD |
119 | /* |
120 | * Protect static_calloc_buf_offset from concurrent updates | |
121 | * using a cmpxchg loop rather than a mutex to remove a | |
122 | * dependency on pthread. This will minimize the risk of bad | |
123 | * interaction between mutex and malloc instrumentation. | |
124 | */ | |
125 | res_offset = CMM_LOAD_SHARED(static_calloc_buf_offset); | |
126 | do { | |
127 | prev_offset = res_offset; | |
b72687b8 | 128 | aligned_offset = LTTNG_UST_ALIGN(prev_offset + sizeof(size_t), alignment); |
2594a5b4 MD |
129 | new_offset = aligned_offset + nmemb * size; |
130 | if (new_offset > sizeof(static_calloc_buf)) { | |
131 | abort(); | |
4c3536e0 | 132 | } |
4c3536e0 MD |
133 | } while ((res_offset = uatomic_cmpxchg(&static_calloc_buf_offset, |
134 | prev_offset, new_offset)) != prev_offset); | |
2594a5b4 MD |
135 | *(size_t *) &static_calloc_buf[aligned_offset - sizeof(size_t)] = size; |
136 | return &static_calloc_buf[aligned_offset]; | |
137 | } | |
138 | ||
139 | static | |
140 | void *static_calloc(size_t nmemb, size_t size) | |
141 | { | |
142 | void *retval; | |
143 | ||
144 | retval = static_calloc_aligned(nmemb, size, 1); | |
2594a5b4 MD |
145 | return retval; |
146 | } | |
147 | ||
148 | static | |
149 | void *static_malloc(size_t size) | |
150 | { | |
151 | void *retval; | |
152 | ||
153 | retval = static_calloc_aligned(1, size, 1); | |
2594a5b4 MD |
154 | return retval; |
155 | } | |
156 | ||
157 | static | |
2208d8b5 | 158 | void static_free(void *ptr __attribute__((unused))) |
2594a5b4 MD |
159 | { |
160 | /* no-op. */ | |
2594a5b4 MD |
161 | } |
162 | ||
163 | static | |
164 | void *static_realloc(void *ptr, size_t size) | |
165 | { | |
166 | size_t *old_size = NULL; | |
167 | void *retval; | |
168 | ||
169 | if (size == 0) { | |
170 | retval = NULL; | |
171 | goto end; | |
172 | } | |
173 | ||
174 | if (ptr) { | |
175 | old_size = (size_t *) ptr - 1; | |
176 | if (size <= *old_size) { | |
177 | /* We can re-use the old entry. */ | |
178 | *old_size = size; | |
179 | retval = ptr; | |
180 | goto end; | |
181 | } | |
182 | } | |
183 | /* We need to expand. Don't free previous memory location. */ | |
184 | retval = static_calloc_aligned(1, size, 1); | |
185 | assert(retval); | |
186 | if (ptr) | |
187 | memcpy(retval, ptr, *old_size); | |
188 | end: | |
2594a5b4 MD |
189 | return retval; |
190 | } | |
191 | ||
192 | static | |
193 | void *static_memalign(size_t alignment, size_t size) | |
194 | { | |
195 | void *retval; | |
196 | ||
197 | retval = static_calloc_aligned(1, size, alignment); | |
2594a5b4 MD |
198 | return retval; |
199 | } | |
200 | ||
201 | static | |
202 | int static_posix_memalign(void **memptr, size_t alignment, size_t size) | |
203 | { | |
2594a5b4 MD |
204 | void *ptr; |
205 | ||
206 | /* Check for power of 2, larger than void *. */ | |
207 | if (alignment & (alignment - 1) | |
208 | || alignment < sizeof(void *) | |
209 | || alignment == 0) { | |
2594a5b4 MD |
210 | goto end; |
211 | } | |
212 | ptr = static_calloc_aligned(1, size, alignment); | |
213 | *memptr = ptr; | |
2594a5b4 | 214 | end: |
2594a5b4 MD |
215 | return 0; |
216 | } | |
217 | ||
218 | static | |
219 | void setup_static_allocator(void) | |
220 | { | |
221 | assert(cur_alloc.calloc == NULL); | |
222 | cur_alloc.calloc = static_calloc; | |
223 | assert(cur_alloc.malloc == NULL); | |
224 | cur_alloc.malloc = static_malloc; | |
225 | assert(cur_alloc.free == NULL); | |
226 | cur_alloc.free = static_free; | |
227 | assert(cur_alloc.realloc == NULL); | |
228 | cur_alloc.realloc = static_realloc; | |
229 | assert(cur_alloc.memalign == NULL); | |
230 | cur_alloc.memalign = static_memalign; | |
231 | assert(cur_alloc.posix_memalign == NULL); | |
232 | cur_alloc.posix_memalign = static_posix_memalign; | |
233 | } | |
234 | ||
235 | static | |
236 | void lookup_all_symbols(void) | |
237 | { | |
238 | struct alloc_functions af; | |
239 | ||
240 | /* | |
241 | * Temporarily redirect allocation functions to | |
242 | * static_calloc_aligned, and free function to static_free | |
243 | * (no-op), until the dlsym lookup has completed. | |
244 | */ | |
245 | setup_static_allocator(); | |
246 | ||
247 | /* Perform the actual lookups */ | |
248 | af.calloc = dlsym(RTLD_NEXT, "calloc"); | |
249 | af.malloc = dlsym(RTLD_NEXT, "malloc"); | |
250 | af.free = dlsym(RTLD_NEXT, "free"); | |
251 | af.realloc = dlsym(RTLD_NEXT, "realloc"); | |
252 | af.memalign = dlsym(RTLD_NEXT, "memalign"); | |
253 | af.posix_memalign = dlsym(RTLD_NEXT, "posix_memalign"); | |
254 | ||
255 | /* Populate the new allocator functions */ | |
256 | memcpy(&cur_alloc, &af, sizeof(cur_alloc)); | |
f95b2888 SS |
257 | } |
258 | ||
e541a28d PMF |
259 | void *malloc(size_t size) |
260 | { | |
1c184644 PMF |
261 | void *retval; |
262 | ||
49400d96 | 263 | malloc_nesting++; |
2594a5b4 MD |
264 | if (cur_alloc.malloc == NULL) { |
265 | lookup_all_symbols(); | |
266 | if (cur_alloc.malloc == NULL) { | |
e541a28d | 267 | fprintf(stderr, "mallocwrap: unable to find malloc\n"); |
2594a5b4 | 268 | abort(); |
e541a28d PMF |
269 | } |
270 | } | |
2594a5b4 | 271 | retval = cur_alloc.malloc(size); |
49400d96 | 272 | if (malloc_nesting == 1) { |
cbc06a3b | 273 | lttng_ust_tracepoint(lttng_ust_libc, malloc, |
171fcc6f | 274 | size, retval, LTTNG_UST_CALLER_IP()); |
8c06ba6f | 275 | } |
49400d96 | 276 | malloc_nesting--; |
1c184644 PMF |
277 | return retval; |
278 | } | |
279 | ||
280 | void free(void *ptr) | |
281 | { | |
49400d96 | 282 | malloc_nesting++; |
2594a5b4 MD |
283 | /* |
284 | * Check whether the memory was allocated with | |
285 | * static_calloc_align, in which case there is nothing to free. | |
f95b2888 | 286 | */ |
2594a5b4 MD |
287 | if (caa_unlikely((char *)ptr >= static_calloc_buf && |
288 | (char *)ptr < static_calloc_buf + STATIC_CALLOC_LEN)) { | |
8c06ba6f MD |
289 | goto end; |
290 | } | |
291 | ||
49400d96 | 292 | if (malloc_nesting == 1) { |
cbc06a3b | 293 | lttng_ust_tracepoint(lttng_ust_libc, free, |
171fcc6f | 294 | ptr, LTTNG_UST_CALLER_IP()); |
f95b2888 | 295 | } |
1c184644 | 296 | |
2594a5b4 MD |
297 | if (cur_alloc.free == NULL) { |
298 | lookup_all_symbols(); | |
299 | if (cur_alloc.free == NULL) { | |
1c184644 | 300 | fprintf(stderr, "mallocwrap: unable to find free\n"); |
2594a5b4 | 301 | abort(); |
1c184644 PMF |
302 | } |
303 | } | |
2594a5b4 | 304 | cur_alloc.free(ptr); |
8c06ba6f | 305 | end: |
49400d96 | 306 | malloc_nesting--; |
e541a28d | 307 | } |
f95b2888 SS |
308 | |
309 | void *calloc(size_t nmemb, size_t size) | |
310 | { | |
f95b2888 SS |
311 | void *retval; |
312 | ||
49400d96 | 313 | malloc_nesting++; |
2594a5b4 MD |
314 | if (cur_alloc.calloc == NULL) { |
315 | lookup_all_symbols(); | |
316 | if (cur_alloc.calloc == NULL) { | |
f95b2888 | 317 | fprintf(stderr, "callocwrap: unable to find calloc\n"); |
2594a5b4 | 318 | abort(); |
f95b2888 SS |
319 | } |
320 | } | |
2594a5b4 | 321 | retval = cur_alloc.calloc(nmemb, size); |
49400d96 | 322 | if (malloc_nesting == 1) { |
cbc06a3b | 323 | lttng_ust_tracepoint(lttng_ust_libc, calloc, |
171fcc6f | 324 | nmemb, size, retval, LTTNG_UST_CALLER_IP()); |
8c06ba6f | 325 | } |
49400d96 | 326 | malloc_nesting--; |
f95b2888 SS |
327 | return retval; |
328 | } | |
329 | ||
330 | void *realloc(void *ptr, size_t size) | |
331 | { | |
f95b2888 SS |
332 | void *retval; |
333 | ||
49400d96 | 334 | malloc_nesting++; |
8c06ba6f MD |
335 | /* |
336 | * Check whether the memory was allocated with | |
2594a5b4 MD |
337 | * static_calloc_align, in which case there is nothing |
338 | * to free, and we need to copy the old data. | |
339 | */ | |
340 | if (caa_unlikely((char *)ptr >= static_calloc_buf && | |
341 | (char *)ptr < static_calloc_buf + STATIC_CALLOC_LEN)) { | |
342 | size_t *old_size; | |
343 | ||
344 | old_size = (size_t *) ptr - 1; | |
345 | if (cur_alloc.calloc == NULL) { | |
346 | lookup_all_symbols(); | |
347 | if (cur_alloc.calloc == NULL) { | |
348 | fprintf(stderr, "reallocwrap: unable to find calloc\n"); | |
349 | abort(); | |
350 | } | |
351 | } | |
352 | retval = cur_alloc.calloc(1, size); | |
353 | if (retval) { | |
354 | memcpy(retval, ptr, *old_size); | |
355 | } | |
8c06ba6f | 356 | /* |
2fbda51c | 357 | * Mimic that a NULL pointer has been received, so |
8c06ba6f MD |
358 | * memory allocation analysis based on the trace don't |
359 | * get confused by the address from the static | |
360 | * allocator. | |
361 | */ | |
362 | ptr = NULL; | |
2594a5b4 MD |
363 | goto end; |
364 | } | |
365 | ||
366 | if (cur_alloc.realloc == NULL) { | |
367 | lookup_all_symbols(); | |
368 | if (cur_alloc.realloc == NULL) { | |
f95b2888 | 369 | fprintf(stderr, "reallocwrap: unable to find realloc\n"); |
2594a5b4 | 370 | abort(); |
f95b2888 SS |
371 | } |
372 | } | |
2594a5b4 MD |
373 | retval = cur_alloc.realloc(ptr, size); |
374 | end: | |
49400d96 | 375 | if (malloc_nesting == 1) { |
cbc06a3b | 376 | lttng_ust_tracepoint(lttng_ust_libc, realloc, |
171fcc6f | 377 | ptr, size, retval, LTTNG_UST_CALLER_IP()); |
8c06ba6f | 378 | } |
49400d96 | 379 | malloc_nesting--; |
f95b2888 SS |
380 | return retval; |
381 | } | |
9d34b226 SS |
382 | |
383 | void *memalign(size_t alignment, size_t size) | |
384 | { | |
9d34b226 SS |
385 | void *retval; |
386 | ||
49400d96 | 387 | malloc_nesting++; |
2594a5b4 MD |
388 | if (cur_alloc.memalign == NULL) { |
389 | lookup_all_symbols(); | |
390 | if (cur_alloc.memalign == NULL) { | |
9d34b226 | 391 | fprintf(stderr, "memalignwrap: unable to find memalign\n"); |
2594a5b4 | 392 | abort(); |
9d34b226 SS |
393 | } |
394 | } | |
2594a5b4 | 395 | retval = cur_alloc.memalign(alignment, size); |
49400d96 | 396 | if (malloc_nesting == 1) { |
cbc06a3b | 397 | lttng_ust_tracepoint(lttng_ust_libc, memalign, |
6d4658aa | 398 | alignment, size, retval, |
171fcc6f | 399 | LTTNG_UST_CALLER_IP()); |
8c06ba6f | 400 | } |
49400d96 | 401 | malloc_nesting--; |
9d34b226 SS |
402 | return retval; |
403 | } | |
404 | ||
405 | int posix_memalign(void **memptr, size_t alignment, size_t size) | |
406 | { | |
9d34b226 SS |
407 | int retval; |
408 | ||
49400d96 | 409 | malloc_nesting++; |
2594a5b4 MD |
410 | if (cur_alloc.posix_memalign == NULL) { |
411 | lookup_all_symbols(); | |
412 | if (cur_alloc.posix_memalign == NULL) { | |
9d34b226 | 413 | fprintf(stderr, "posix_memalignwrap: unable to find posix_memalign\n"); |
2594a5b4 | 414 | abort(); |
9d34b226 SS |
415 | } |
416 | } | |
2594a5b4 | 417 | retval = cur_alloc.posix_memalign(memptr, alignment, size); |
49400d96 | 418 | if (malloc_nesting == 1) { |
cbc06a3b | 419 | lttng_ust_tracepoint(lttng_ust_libc, posix_memalign, |
6d4658aa | 420 | *memptr, alignment, size, |
171fcc6f | 421 | retval, LTTNG_UST_CALLER_IP()); |
8c06ba6f | 422 | } |
49400d96 | 423 | malloc_nesting--; |
9d34b226 SS |
424 | return retval; |
425 | } | |
2594a5b4 | 426 | |
fca97dfd | 427 | void lttng_ust_libc_wrapper_malloc_ctor(void) |
2594a5b4 MD |
428 | { |
429 | /* Initialization already done */ | |
430 | if (cur_alloc.calloc) { | |
431 | return; | |
432 | } | |
433 | /* | |
434 | * Ensure the allocator is in place before the process becomes | |
435 | * multithreaded. | |
436 | */ | |
437 | lookup_all_symbols(); | |
438 | } |