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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 | ||
cf73e0fe | 20 | #define _GNU_SOURCE |
1ddceb36 | 21 | #define _LGPL_SOURCE |
8e2aed3f | 22 | #include <link.h> |
cf73e0fe | 23 | #include <limits.h> |
cf73e0fe | 24 | #include <stdio.h> |
8e2aed3f AB |
25 | #include <stdint.h> |
26 | #include <stdlib.h> | |
27 | #include <sys/types.h> | |
28 | #include <unistd.h> | |
cf73e0fe | 29 | |
8e2aed3f | 30 | #include <lttng/ust-elf.h> |
cf73e0fe AB |
31 | #include "lttng-tracer-core.h" |
32 | #include "lttng-ust-statedump.h" | |
33 | ||
34 | #define TRACEPOINT_DEFINE | |
35 | #define TRACEPOINT_CREATE_PROBES | |
36 | #define TP_SESSION_CHECK | |
37 | #include "lttng-ust-statedump-provider.h" | |
38 | ||
39 | struct dl_iterate_data { | |
40 | void *owner; | |
41 | int exec_found; | |
42 | }; | |
43 | ||
f60e49df | 44 | struct bin_info_data { |
cf73e0fe AB |
45 | void *owner; |
46 | void *base_addr_ptr; | |
47 | const char *resolved_path; | |
8e2aed3f AB |
48 | char *dbg_file; |
49 | uint8_t *build_id; | |
50 | uint64_t memsz; | |
51 | size_t build_id_len; | |
cf73e0fe | 52 | int vdso; |
8e2aed3f | 53 | uint32_t crc; |
f5eb039d | 54 | uint8_t is_pic; |
c5c4fd82 MD |
55 | uint8_t has_build_id; |
56 | uint8_t has_debug_link; | |
cf73e0fe AB |
57 | }; |
58 | ||
59 | typedef void (*tracepoint_cb)(struct lttng_session *session, void *priv); | |
60 | ||
61 | /* | |
62 | * Trace statedump event into all sessions owned by the caller thread | |
63 | * for which statedump is pending. | |
64 | */ | |
65 | static | |
66 | int trace_statedump_event(tracepoint_cb tp_cb, void *owner, void *priv) | |
67 | { | |
68 | struct cds_list_head *sessionsp; | |
69 | struct lttng_session *session; | |
70 | ||
cf73e0fe AB |
71 | sessionsp = _lttng_get_sessions(); |
72 | cds_list_for_each_entry(session, sessionsp, node) { | |
73 | if (session->owner != owner) | |
74 | continue; | |
75 | if (!session->statedump_pending) | |
76 | continue; | |
77 | tp_cb(session, priv); | |
78 | } | |
cf73e0fe AB |
79 | return 0; |
80 | } | |
81 | ||
82 | static | |
f60e49df | 83 | void trace_bin_info_cb(struct lttng_session *session, void *priv) |
cf73e0fe | 84 | { |
f60e49df | 85 | struct bin_info_data *bin_data = (struct bin_info_data *) priv; |
cf73e0fe | 86 | |
f60e49df AB |
87 | tracepoint(lttng_ust_statedump, bin_info, |
88 | session, bin_data->base_addr_ptr, | |
c5c4fd82 MD |
89 | bin_data->resolved_path, bin_data->memsz, |
90 | bin_data->is_pic, bin_data->has_build_id, | |
91 | bin_data->has_debug_link); | |
8e2aed3f AB |
92 | } |
93 | ||
94 | static | |
95 | void trace_build_id_cb(struct lttng_session *session, void *priv) | |
96 | { | |
f60e49df | 97 | struct bin_info_data *bin_data = (struct bin_info_data *) priv; |
8e2aed3f AB |
98 | |
99 | tracepoint(lttng_ust_statedump, build_id, | |
f60e49df AB |
100 | session, bin_data->base_addr_ptr, |
101 | bin_data->build_id, bin_data->build_id_len); | |
8e2aed3f AB |
102 | } |
103 | ||
104 | static | |
105 | void trace_debug_link_cb(struct lttng_session *session, void *priv) | |
106 | { | |
f60e49df | 107 | struct bin_info_data *bin_data = (struct bin_info_data *) priv; |
8e2aed3f AB |
108 | |
109 | tracepoint(lttng_ust_statedump, debug_link, | |
f60e49df AB |
110 | session, bin_data->base_addr_ptr, |
111 | bin_data->dbg_file, bin_data->crc); | |
cf73e0fe AB |
112 | } |
113 | ||
114 | static | |
115 | void trace_start_cb(struct lttng_session *session, void *priv) | |
116 | { | |
117 | tracepoint(lttng_ust_statedump, start, session); | |
118 | } | |
119 | ||
120 | static | |
121 | void trace_end_cb(struct lttng_session *session, void *priv) | |
122 | { | |
123 | tracepoint(lttng_ust_statedump, end, session); | |
124 | } | |
125 | ||
8e2aed3f | 126 | static |
c5c4fd82 MD |
127 | int get_elf_info(struct bin_info_data *bin_data) |
128 | { | |
8e2aed3f | 129 | struct lttng_ust_elf *elf; |
c5c4fd82 | 130 | int ret = 0, found; |
8e2aed3f | 131 | |
f60e49df | 132 | elf = lttng_ust_elf_create(bin_data->resolved_path); |
8e2aed3f AB |
133 | if (!elf) { |
134 | ret = -1; | |
135 | goto end; | |
136 | } | |
137 | ||
f60e49df | 138 | ret = lttng_ust_elf_get_memsz(elf, &bin_data->memsz); |
8e2aed3f AB |
139 | if (ret) { |
140 | goto end; | |
141 | } | |
142 | ||
c5c4fd82 | 143 | found = 0; |
f60e49df | 144 | ret = lttng_ust_elf_get_build_id(elf, &bin_data->build_id, |
c5c4fd82 MD |
145 | &bin_data->build_id_len, |
146 | &found); | |
8e2aed3f AB |
147 | if (ret) { |
148 | goto end; | |
149 | } | |
c5c4fd82 MD |
150 | bin_data->has_build_id = !!found; |
151 | found = 0; | |
f60e49df | 152 | ret = lttng_ust_elf_get_debug_link(elf, &bin_data->dbg_file, |
c5c4fd82 MD |
153 | &bin_data->crc, |
154 | &found); | |
8e2aed3f AB |
155 | if (ret) { |
156 | goto end; | |
157 | } | |
c5c4fd82 | 158 | bin_data->has_debug_link = !!found; |
8e2aed3f | 159 | |
f60e49df | 160 | bin_data->is_pic = lttng_ust_elf_is_pic(elf); |
f5eb039d | 161 | |
8e2aed3f AB |
162 | end: |
163 | lttng_ust_elf_destroy(elf); | |
164 | return ret; | |
165 | } | |
166 | ||
cf73e0fe | 167 | static |
f60e49df | 168 | int trace_baddr(struct bin_info_data *bin_data) |
cf73e0fe | 169 | { |
c5c4fd82 | 170 | int ret = 0; |
8e2aed3f | 171 | |
f60e49df | 172 | if (!bin_data->vdso) { |
c5c4fd82 | 173 | ret = get_elf_info(bin_data); |
8e2aed3f AB |
174 | if (ret) { |
175 | goto end; | |
176 | } | |
177 | } else { | |
f60e49df | 178 | bin_data->memsz = 0; |
fd783031 MD |
179 | bin_data->has_build_id = 0; |
180 | bin_data->has_debug_link = 0; | |
8e2aed3f AB |
181 | } |
182 | ||
f60e49df AB |
183 | ret = trace_statedump_event(trace_bin_info_cb, bin_data->owner, |
184 | bin_data); | |
8e2aed3f AB |
185 | if (ret) { |
186 | goto end; | |
187 | } | |
cf73e0fe | 188 | |
c5c4fd82 | 189 | if (bin_data->has_build_id) { |
8e2aed3f | 190 | ret = trace_statedump_event( |
f60e49df AB |
191 | trace_build_id_cb, bin_data->owner, bin_data); |
192 | free(bin_data->build_id); | |
8e2aed3f AB |
193 | if (ret) { |
194 | goto end; | |
195 | } | |
cf73e0fe AB |
196 | } |
197 | ||
c5c4fd82 | 198 | if (bin_data->has_debug_link) { |
8e2aed3f | 199 | ret = trace_statedump_event( |
f60e49df AB |
200 | trace_debug_link_cb, bin_data->owner, bin_data); |
201 | free(bin_data->dbg_file); | |
8e2aed3f AB |
202 | if (ret) { |
203 | goto end; | |
204 | } | |
205 | } | |
cf73e0fe | 206 | |
8e2aed3f AB |
207 | end: |
208 | return ret; | |
cf73e0fe AB |
209 | } |
210 | ||
211 | static | |
212 | int trace_statedump_start(void *owner) | |
213 | { | |
214 | return trace_statedump_event(trace_start_cb, owner, NULL); | |
215 | } | |
216 | ||
217 | static | |
218 | int trace_statedump_end(void *owner) | |
219 | { | |
220 | return trace_statedump_event(trace_end_cb, owner, NULL); | |
221 | } | |
222 | ||
223 | static | |
f60e49df | 224 | int extract_bin_info_events(struct dl_phdr_info *info, size_t size, void *_data) |
cf73e0fe | 225 | { |
d34e6761 | 226 | int j, ret = 0; |
cf73e0fe AB |
227 | struct dl_iterate_data *data = _data; |
228 | ||
d34e6761 MD |
229 | /* |
230 | * UST lock nests within dynamic loader lock. | |
231 | * | |
232 | * Hold this lock across handling of the entire module to | |
233 | * protect memory allocation at early process start, due to | |
234 | * interactions with libc-wrapper lttng malloc instrumentation. | |
235 | */ | |
236 | if (ust_lock()) { | |
237 | goto end; | |
238 | } | |
239 | ||
cf73e0fe | 240 | for (j = 0; j < info->dlpi_phnum; j++) { |
f60e49df | 241 | struct bin_info_data bin_data; |
cf73e0fe AB |
242 | char resolved_path[PATH_MAX]; |
243 | void *base_addr_ptr; | |
244 | ||
245 | if (info->dlpi_phdr[j].p_type != PT_LOAD) | |
246 | continue; | |
247 | ||
248 | /* Calculate virtual memory address of the loadable segment */ | |
249 | base_addr_ptr = (void *) info->dlpi_addr + | |
250 | info->dlpi_phdr[j].p_vaddr; | |
251 | ||
252 | if ((info->dlpi_name == NULL || info->dlpi_name[0] == 0)) { | |
253 | /* | |
254 | * Only the first phdr without a dlpi_name | |
255 | * encountered is considered as the program | |
256 | * executable. The rest are vdsos. | |
257 | */ | |
258 | if (!data->exec_found) { | |
259 | ssize_t path_len; | |
260 | data->exec_found = 1; | |
261 | ||
262 | /* | |
263 | * Use /proc/self/exe to resolve the | |
264 | * executable's full path. | |
265 | */ | |
266 | path_len = readlink("/proc/self/exe", | |
267 | resolved_path, | |
268 | PATH_MAX - 1); | |
269 | if (path_len <= 0) | |
270 | break; | |
271 | ||
272 | resolved_path[path_len] = '\0'; | |
f60e49df | 273 | bin_data.vdso = 0; |
cf73e0fe AB |
274 | } else { |
275 | snprintf(resolved_path, PATH_MAX - 1, "[vdso]"); | |
f60e49df | 276 | bin_data.vdso = 1; |
cf73e0fe AB |
277 | } |
278 | } else { | |
279 | /* | |
280 | * For regular dl_phdr_info entries check if | |
f60e49df | 281 | * the path to the binary really exists. If not, |
cf73e0fe AB |
282 | * treat as vdso and use dlpi_name as 'path'. |
283 | */ | |
284 | if (!realpath(info->dlpi_name, resolved_path)) { | |
285 | snprintf(resolved_path, PATH_MAX - 1, "[%s]", | |
286 | info->dlpi_name); | |
f60e49df | 287 | bin_data.vdso = 1; |
89be5359 | 288 | } else { |
f60e49df | 289 | bin_data.vdso = 0; |
cf73e0fe AB |
290 | } |
291 | } | |
292 | ||
f60e49df AB |
293 | bin_data.owner = data->owner; |
294 | bin_data.base_addr_ptr = base_addr_ptr; | |
295 | bin_data.resolved_path = resolved_path; | |
296 | ret = trace_baddr(&bin_data); | |
d34e6761 | 297 | break; |
cf73e0fe | 298 | } |
d34e6761 MD |
299 | end: |
300 | ust_unlock(); | |
301 | return ret; | |
cf73e0fe AB |
302 | } |
303 | ||
304 | /* | |
305 | * Generate a statedump of base addresses of all shared objects loaded | |
306 | * by the traced application, as well as for the application's | |
307 | * executable itself. | |
308 | */ | |
309 | static | |
310 | int do_baddr_statedump(void *owner) | |
311 | { | |
312 | struct dl_iterate_data data; | |
313 | ||
314 | if (getenv("LTTNG_UST_WITHOUT_BADDR_STATEDUMP")) | |
315 | return 0; | |
316 | ||
317 | data.owner = owner; | |
318 | data.exec_found = 0; | |
319 | /* | |
320 | * Iterate through the list of currently loaded shared objects and | |
321 | * generate events for loadable segments using | |
f60e49df | 322 | * extract_bin_info_events. |
cf73e0fe | 323 | */ |
f60e49df | 324 | dl_iterate_phdr(extract_bin_info_events, &data); |
cf73e0fe AB |
325 | |
326 | return 0; | |
327 | } | |
328 | ||
329 | /* | |
330 | * Generate a statedump of a given traced application. A statedump is | |
331 | * delimited by start and end events. For a given (process, session) | |
332 | * pair, begin/end events are serialized and will match. However, in a | |
333 | * session, statedumps from different processes may be | |
334 | * interleaved. The vpid context should be used to identify which | |
335 | * events belong to which process. | |
336 | */ | |
337 | int do_lttng_ust_statedump(void *owner) | |
338 | { | |
339 | trace_statedump_start(owner); | |
340 | do_baddr_statedump(owner); | |
341 | trace_statedump_end(owner); | |
342 | ||
343 | return 0; | |
344 | } | |
345 | ||
346 | void lttng_ust_statedump_init(void) | |
347 | { | |
348 | __tracepoints__init(); | |
349 | __tracepoints__ptrs_init(); | |
350 | __lttng_events_init__lttng_ust_statedump(); | |
351 | } | |
352 | ||
353 | void lttng_ust_statedump_destroy(void) | |
354 | { | |
355 | __lttng_events_exit__lttng_ust_statedump(); | |
356 | __tracepoints__ptrs_destroy(); | |
357 | __tracepoints__destroy(); | |
358 | } |