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