Commit | Line | Data |
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cf73e0fe AB |
1 | /* |
2 | * Copyright (C) 2013 Paul Woegerer <paul_woegerer@mentor.com> | |
3 | * Copyright (C) 2015 Antoine Busque <abusque@efficios.com> | |
4 | * | |
5 | * This library is free software; you can redistribute it and/or | |
6 | * modify it under the terms of the GNU Lesser General Public | |
7 | * License as published by the Free Software Foundation; either | |
8 | * version 2.1 of the License, or (at your option) any later version. | |
9 | * | |
10 | * This library is distributed in the hope that it will be useful, | |
11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
13 | * Lesser General Public License for more details. | |
14 | * | |
15 | * You should have received a copy of the GNU Lesser General Public | |
16 | * License along with this library; if not, write to the Free Software | |
17 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
18 | */ | |
19 | ||
20 | #define _LGPL_SOURCE | |
21 | #define _GNU_SOURCE | |
cf73e0fe | 22 | |
8e2aed3f | 23 | #include <link.h> |
cf73e0fe | 24 | #include <limits.h> |
cf73e0fe | 25 | #include <stdio.h> |
8e2aed3f AB |
26 | #include <stdint.h> |
27 | #include <stdlib.h> | |
28 | #include <sys/types.h> | |
29 | #include <unistd.h> | |
cf73e0fe | 30 | |
8e2aed3f | 31 | #include <lttng/ust-elf.h> |
cf73e0fe AB |
32 | #include "lttng-tracer-core.h" |
33 | #include "lttng-ust-statedump.h" | |
c452ee17 | 34 | #include "getenv.h" |
cf73e0fe AB |
35 | |
36 | #define TRACEPOINT_DEFINE | |
37 | #define TRACEPOINT_CREATE_PROBES | |
38 | #define TP_SESSION_CHECK | |
39 | #include "lttng-ust-statedump-provider.h" | |
40 | ||
41 | struct dl_iterate_data { | |
42 | void *owner; | |
43 | int exec_found; | |
44 | }; | |
45 | ||
ee047a74 | 46 | struct bin_info_data { |
cf73e0fe AB |
47 | void *owner; |
48 | void *base_addr_ptr; | |
49 | const char *resolved_path; | |
8e2aed3f AB |
50 | char *dbg_file; |
51 | uint8_t *build_id; | |
52 | uint64_t memsz; | |
53 | size_t build_id_len; | |
cf73e0fe | 54 | int vdso; |
8e2aed3f | 55 | uint32_t crc; |
444da810 | 56 | uint8_t is_pic; |
a435064b MD |
57 | uint8_t has_build_id; |
58 | uint8_t has_debug_link; | |
cf73e0fe AB |
59 | }; |
60 | ||
61 | typedef void (*tracepoint_cb)(struct lttng_session *session, void *priv); | |
62 | ||
63 | /* | |
64 | * Trace statedump event into all sessions owned by the caller thread | |
65 | * for which statedump is pending. | |
66 | */ | |
67 | static | |
68 | int trace_statedump_event(tracepoint_cb tp_cb, void *owner, void *priv) | |
69 | { | |
70 | struct cds_list_head *sessionsp; | |
71 | struct lttng_session *session; | |
72 | ||
cf73e0fe AB |
73 | sessionsp = _lttng_get_sessions(); |
74 | cds_list_for_each_entry(session, sessionsp, node) { | |
75 | if (session->owner != owner) | |
76 | continue; | |
77 | if (!session->statedump_pending) | |
78 | continue; | |
79 | tp_cb(session, priv); | |
80 | } | |
cf73e0fe AB |
81 | return 0; |
82 | } | |
83 | ||
84 | static | |
ee047a74 | 85 | void trace_bin_info_cb(struct lttng_session *session, void *priv) |
cf73e0fe | 86 | { |
ee047a74 | 87 | struct bin_info_data *bin_data = (struct bin_info_data *) priv; |
cf73e0fe | 88 | |
ee047a74 AB |
89 | tracepoint(lttng_ust_statedump, bin_info, |
90 | session, bin_data->base_addr_ptr, | |
a435064b MD |
91 | bin_data->resolved_path, bin_data->memsz, |
92 | bin_data->is_pic, bin_data->has_build_id, | |
93 | bin_data->has_debug_link); | |
8e2aed3f AB |
94 | } |
95 | ||
96 | static | |
97 | void trace_build_id_cb(struct lttng_session *session, void *priv) | |
98 | { | |
ee047a74 | 99 | struct bin_info_data *bin_data = (struct bin_info_data *) priv; |
8e2aed3f AB |
100 | |
101 | tracepoint(lttng_ust_statedump, build_id, | |
ee047a74 AB |
102 | session, bin_data->base_addr_ptr, |
103 | bin_data->build_id, bin_data->build_id_len); | |
8e2aed3f AB |
104 | } |
105 | ||
106 | static | |
107 | void trace_debug_link_cb(struct lttng_session *session, void *priv) | |
108 | { | |
ee047a74 | 109 | struct bin_info_data *bin_data = (struct bin_info_data *) priv; |
8e2aed3f AB |
110 | |
111 | tracepoint(lttng_ust_statedump, debug_link, | |
ee047a74 AB |
112 | session, bin_data->base_addr_ptr, |
113 | bin_data->dbg_file, bin_data->crc); | |
cf73e0fe AB |
114 | } |
115 | ||
116 | static | |
117 | void trace_start_cb(struct lttng_session *session, void *priv) | |
118 | { | |
119 | tracepoint(lttng_ust_statedump, start, session); | |
120 | } | |
121 | ||
122 | static | |
123 | void trace_end_cb(struct lttng_session *session, void *priv) | |
124 | { | |
125 | tracepoint(lttng_ust_statedump, end, session); | |
126 | } | |
127 | ||
8e2aed3f | 128 | static |
a435064b MD |
129 | int get_elf_info(struct bin_info_data *bin_data) |
130 | { | |
8e2aed3f | 131 | struct lttng_ust_elf *elf; |
a435064b | 132 | int ret = 0, found; |
8e2aed3f | 133 | |
ee047a74 | 134 | elf = lttng_ust_elf_create(bin_data->resolved_path); |
8e2aed3f AB |
135 | if (!elf) { |
136 | ret = -1; | |
137 | goto end; | |
138 | } | |
139 | ||
ee047a74 | 140 | ret = lttng_ust_elf_get_memsz(elf, &bin_data->memsz); |
8e2aed3f AB |
141 | if (ret) { |
142 | goto end; | |
143 | } | |
144 | ||
a435064b | 145 | found = 0; |
ee047a74 | 146 | ret = lttng_ust_elf_get_build_id(elf, &bin_data->build_id, |
a435064b MD |
147 | &bin_data->build_id_len, |
148 | &found); | |
8e2aed3f AB |
149 | if (ret) { |
150 | goto end; | |
151 | } | |
a435064b MD |
152 | bin_data->has_build_id = !!found; |
153 | found = 0; | |
ee047a74 | 154 | ret = lttng_ust_elf_get_debug_link(elf, &bin_data->dbg_file, |
a435064b MD |
155 | &bin_data->crc, |
156 | &found); | |
8e2aed3f AB |
157 | if (ret) { |
158 | goto end; | |
159 | } | |
a435064b | 160 | bin_data->has_debug_link = !!found; |
8e2aed3f | 161 | |
ee047a74 | 162 | bin_data->is_pic = lttng_ust_elf_is_pic(elf); |
444da810 | 163 | |
8e2aed3f AB |
164 | end: |
165 | lttng_ust_elf_destroy(elf); | |
166 | return ret; | |
167 | } | |
168 | ||
cf73e0fe | 169 | static |
ee047a74 | 170 | int trace_baddr(struct bin_info_data *bin_data) |
cf73e0fe | 171 | { |
a435064b | 172 | int ret = 0; |
8e2aed3f | 173 | |
ee047a74 | 174 | if (!bin_data->vdso) { |
a435064b | 175 | ret = get_elf_info(bin_data); |
8e2aed3f AB |
176 | if (ret) { |
177 | goto end; | |
178 | } | |
179 | } else { | |
ee047a74 | 180 | bin_data->memsz = 0; |
2bb51006 MD |
181 | bin_data->has_build_id = 0; |
182 | bin_data->has_debug_link = 0; | |
8e2aed3f AB |
183 | } |
184 | ||
ee047a74 AB |
185 | ret = trace_statedump_event(trace_bin_info_cb, bin_data->owner, |
186 | bin_data); | |
8e2aed3f AB |
187 | if (ret) { |
188 | goto end; | |
189 | } | |
cf73e0fe | 190 | |
a435064b | 191 | if (bin_data->has_build_id) { |
8e2aed3f | 192 | ret = trace_statedump_event( |
ee047a74 AB |
193 | trace_build_id_cb, bin_data->owner, bin_data); |
194 | free(bin_data->build_id); | |
8e2aed3f AB |
195 | if (ret) { |
196 | goto end; | |
197 | } | |
cf73e0fe AB |
198 | } |
199 | ||
a435064b | 200 | if (bin_data->has_debug_link) { |
8e2aed3f | 201 | ret = trace_statedump_event( |
ee047a74 AB |
202 | trace_debug_link_cb, bin_data->owner, bin_data); |
203 | free(bin_data->dbg_file); | |
8e2aed3f AB |
204 | if (ret) { |
205 | goto end; | |
206 | } | |
207 | } | |
cf73e0fe | 208 | |
8e2aed3f AB |
209 | end: |
210 | return ret; | |
cf73e0fe AB |
211 | } |
212 | ||
213 | static | |
214 | int trace_statedump_start(void *owner) | |
215 | { | |
216 | return trace_statedump_event(trace_start_cb, owner, NULL); | |
217 | } | |
218 | ||
219 | static | |
220 | int trace_statedump_end(void *owner) | |
221 | { | |
222 | return trace_statedump_event(trace_end_cb, owner, NULL); | |
223 | } | |
224 | ||
225 | static | |
ee047a74 | 226 | int extract_bin_info_events(struct dl_phdr_info *info, size_t size, void *_data) |
cf73e0fe | 227 | { |
d34e6761 | 228 | int j, ret = 0; |
cf73e0fe AB |
229 | struct dl_iterate_data *data = _data; |
230 | ||
d34e6761 MD |
231 | /* |
232 | * UST lock nests within dynamic loader lock. | |
233 | * | |
234 | * Hold this lock across handling of the entire module to | |
235 | * protect memory allocation at early process start, due to | |
236 | * interactions with libc-wrapper lttng malloc instrumentation. | |
237 | */ | |
238 | if (ust_lock()) { | |
239 | goto end; | |
240 | } | |
241 | ||
cf73e0fe | 242 | for (j = 0; j < info->dlpi_phnum; j++) { |
ee047a74 | 243 | struct bin_info_data bin_data; |
cf73e0fe AB |
244 | char resolved_path[PATH_MAX]; |
245 | void *base_addr_ptr; | |
246 | ||
247 | if (info->dlpi_phdr[j].p_type != PT_LOAD) | |
248 | continue; | |
249 | ||
250 | /* Calculate virtual memory address of the loadable segment */ | |
251 | base_addr_ptr = (void *) info->dlpi_addr + | |
252 | info->dlpi_phdr[j].p_vaddr; | |
253 | ||
254 | if ((info->dlpi_name == NULL || info->dlpi_name[0] == 0)) { | |
255 | /* | |
256 | * Only the first phdr without a dlpi_name | |
257 | * encountered is considered as the program | |
258 | * executable. The rest are vdsos. | |
259 | */ | |
260 | if (!data->exec_found) { | |
261 | ssize_t path_len; | |
262 | data->exec_found = 1; | |
263 | ||
264 | /* | |
265 | * Use /proc/self/exe to resolve the | |
266 | * executable's full path. | |
267 | */ | |
268 | path_len = readlink("/proc/self/exe", | |
269 | resolved_path, | |
270 | PATH_MAX - 1); | |
271 | if (path_len <= 0) | |
272 | break; | |
273 | ||
274 | resolved_path[path_len] = '\0'; | |
ee047a74 | 275 | bin_data.vdso = 0; |
cf73e0fe AB |
276 | } else { |
277 | snprintf(resolved_path, PATH_MAX - 1, "[vdso]"); | |
ee047a74 | 278 | bin_data.vdso = 1; |
cf73e0fe AB |
279 | } |
280 | } else { | |
281 | /* | |
282 | * For regular dl_phdr_info entries check if | |
ee047a74 | 283 | * the path to the binary really exists. If not, |
cf73e0fe AB |
284 | * treat as vdso and use dlpi_name as 'path'. |
285 | */ | |
286 | if (!realpath(info->dlpi_name, resolved_path)) { | |
287 | snprintf(resolved_path, PATH_MAX - 1, "[%s]", | |
288 | info->dlpi_name); | |
ee047a74 | 289 | bin_data.vdso = 1; |
89be5359 | 290 | } else { |
ee047a74 | 291 | bin_data.vdso = 0; |
cf73e0fe AB |
292 | } |
293 | } | |
294 | ||
ee047a74 AB |
295 | bin_data.owner = data->owner; |
296 | bin_data.base_addr_ptr = base_addr_ptr; | |
297 | bin_data.resolved_path = resolved_path; | |
298 | ret = trace_baddr(&bin_data); | |
d34e6761 | 299 | break; |
cf73e0fe | 300 | } |
d34e6761 MD |
301 | end: |
302 | ust_unlock(); | |
303 | return ret; | |
cf73e0fe AB |
304 | } |
305 | ||
306 | /* | |
307 | * Generate a statedump of base addresses of all shared objects loaded | |
308 | * by the traced application, as well as for the application's | |
309 | * executable itself. | |
310 | */ | |
311 | static | |
312 | int do_baddr_statedump(void *owner) | |
313 | { | |
314 | struct dl_iterate_data data; | |
315 | ||
c452ee17 | 316 | if (lttng_getenv("LTTNG_UST_WITHOUT_BADDR_STATEDUMP")) |
cf73e0fe AB |
317 | return 0; |
318 | ||
a3b964eb MD |
319 | /* |
320 | * Fixup lttng-ust TLS when called from dlopen/dlclose | |
321 | * instrumentation. | |
322 | */ | |
323 | lttng_ust_fixup_tls(); | |
324 | ||
cf73e0fe AB |
325 | data.owner = owner; |
326 | data.exec_found = 0; | |
327 | /* | |
328 | * Iterate through the list of currently loaded shared objects and | |
329 | * generate events for loadable segments using | |
ee047a74 | 330 | * extract_bin_info_events. |
cf73e0fe | 331 | */ |
ee047a74 | 332 | dl_iterate_phdr(extract_bin_info_events, &data); |
cf73e0fe AB |
333 | |
334 | return 0; | |
335 | } | |
336 | ||
337 | /* | |
338 | * Generate a statedump of a given traced application. A statedump is | |
339 | * delimited by start and end events. For a given (process, session) | |
340 | * pair, begin/end events are serialized and will match. However, in a | |
341 | * session, statedumps from different processes may be | |
342 | * interleaved. The vpid context should be used to identify which | |
343 | * events belong to which process. | |
246bb09a MD |
344 | * |
345 | * Grab the ust_lock outside of the RCU read-side lock because we | |
346 | * perform synchronize_rcu with the ust_lock held, which can trigger | |
347 | * deadlocks otherwise. | |
cf73e0fe AB |
348 | */ |
349 | int do_lttng_ust_statedump(void *owner) | |
350 | { | |
246bb09a | 351 | ust_lock_nocheck(); |
cf73e0fe | 352 | trace_statedump_start(owner); |
246bb09a MD |
353 | ust_unlock(); |
354 | ||
cf73e0fe | 355 | do_baddr_statedump(owner); |
246bb09a MD |
356 | |
357 | ust_lock_nocheck(); | |
cf73e0fe | 358 | trace_statedump_end(owner); |
246bb09a | 359 | ust_unlock(); |
cf73e0fe AB |
360 | |
361 | return 0; | |
362 | } | |
363 | ||
364 | void lttng_ust_statedump_init(void) | |
365 | { | |
366 | __tracepoints__init(); | |
367 | __tracepoints__ptrs_init(); | |
368 | __lttng_events_init__lttng_ust_statedump(); | |
369 | } | |
370 | ||
371 | void lttng_ust_statedump_destroy(void) | |
372 | { | |
373 | __lttng_events_exit__lttng_ust_statedump(); | |
374 | __tracepoints__ptrs_destroy(); | |
375 | __tracepoints__destroy(); | |
376 | } |