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1
2#include <unistd.h>
3#include <stdio.h>
4#include <string.h>
5#include <sys/types.h>
6#include <sys/stat.h>
7#include <fcntl.h>
8#include <stdlib.h>
9#include <linux/kernel.h>
10
11#include "vdso.h"
12#include "util.h"
13#include "symbol.h"
14#include "machine.h"
15#include "thread.h"
16#include "linux/string.h"
17#include "debug.h"
18
19/*
20 * Include definition of find_vdso_map() also used in perf-read-vdso.c for
21 * building perf-read-vdso32 and perf-read-vdsox32.
22 */
23#include "find-vdso-map.c"
24
25#define VDSO__TEMP_FILE_NAME "/tmp/perf-vdso.so-XXXXXX"
26
27struct vdso_file {
28 bool found;
29 bool error;
30 char temp_file_name[sizeof(VDSO__TEMP_FILE_NAME)];
31 const char *dso_name;
32 const char *read_prog;
33};
34
35struct vdso_info {
36 struct vdso_file vdso;
37#if BITS_PER_LONG == 64
38 struct vdso_file vdso32;
39 struct vdso_file vdsox32;
40#endif
41};
42
43static struct vdso_info *vdso_info__new(void)
44{
45 static const struct vdso_info vdso_info_init = {
46 .vdso = {
47 .temp_file_name = VDSO__TEMP_FILE_NAME,
48 .dso_name = DSO__NAME_VDSO,
49 },
50#if BITS_PER_LONG == 64
51 .vdso32 = {
52 .temp_file_name = VDSO__TEMP_FILE_NAME,
53 .dso_name = DSO__NAME_VDSO32,
54 .read_prog = "perf-read-vdso32",
55 },
56 .vdsox32 = {
57 .temp_file_name = VDSO__TEMP_FILE_NAME,
58 .dso_name = DSO__NAME_VDSOX32,
59 .read_prog = "perf-read-vdsox32",
60 },
61#endif
62 };
63
64 return memdup(&vdso_info_init, sizeof(vdso_info_init));
65}
66
67static char *get_file(struct vdso_file *vdso_file)
68{
69 char *vdso = NULL;
70 char *buf = NULL;
71 void *start, *end;
72 size_t size;
73 int fd;
74
75 if (vdso_file->found)
76 return vdso_file->temp_file_name;
77
78 if (vdso_file->error || find_vdso_map(&start, &end))
79 return NULL;
80
81 size = end - start;
82
83 buf = memdup(start, size);
84 if (!buf)
85 return NULL;
86
87 fd = mkstemp(vdso_file->temp_file_name);
88 if (fd < 0)
89 goto out;
90
91 if (size == (size_t) write(fd, buf, size))
92 vdso = vdso_file->temp_file_name;
93
94 close(fd);
95
96 out:
97 free(buf);
98
99 vdso_file->found = (vdso != NULL);
100 vdso_file->error = !vdso_file->found;
101 return vdso;
102}
103
104void machine__exit_vdso(struct machine *machine)
105{
106 struct vdso_info *vdso_info = machine->vdso_info;
107
108 if (!vdso_info)
109 return;
110
111 if (vdso_info->vdso.found)
112 unlink(vdso_info->vdso.temp_file_name);
113#if BITS_PER_LONG == 64
114 if (vdso_info->vdso32.found)
115 unlink(vdso_info->vdso32.temp_file_name);
116 if (vdso_info->vdsox32.found)
117 unlink(vdso_info->vdsox32.temp_file_name);
118#endif
119
120 zfree(&machine->vdso_info);
121}
122
123static struct dso *__machine__addnew_vdso(struct machine *machine, const char *short_name,
124 const char *long_name)
125{
126 struct dso *dso;
127
128 dso = dso__new(short_name);
129 if (dso != NULL) {
130 __dsos__add(&machine->dsos, dso);
131 dso__set_long_name(dso, long_name, false);
132 }
133
134 return dso;
135}
136
137#if BITS_PER_LONG == 64
138
139static enum dso_type machine__thread_dso_type(struct machine *machine,
140 struct thread *thread)
141{
142 enum dso_type dso_type = DSO__TYPE_UNKNOWN;
143 struct map *map;
144 struct dso *dso;
145
146 map = map_groups__first(thread->mg, MAP__FUNCTION);
147 for (; map ; map = map_groups__next(map)) {
148 dso = map->dso;
149 if (!dso || dso->long_name[0] != '/')
150 continue;
151 dso_type = dso__type(dso, machine);
152 if (dso_type != DSO__TYPE_UNKNOWN)
153 break;
154 }
155
156 return dso_type;
157}
158
159static int vdso__do_copy_compat(FILE *f, int fd)
160{
161 char buf[4096];
162 size_t count;
163
164 while (1) {
165 count = fread(buf, 1, sizeof(buf), f);
166 if (ferror(f))
167 return -errno;
168 if (feof(f))
169 break;
170 if (count && writen(fd, buf, count) != (ssize_t)count)
171 return -errno;
172 }
173
174 return 0;
175}
176
177static int vdso__copy_compat(const char *prog, int fd)
178{
179 FILE *f;
180 int err;
181
182 f = popen(prog, "r");
183 if (!f)
184 return -errno;
185
186 err = vdso__do_copy_compat(f, fd);
187
188 if (pclose(f) == -1)
189 return -errno;
190
191 return err;
192}
193
194static int vdso__create_compat_file(const char *prog, char *temp_name)
195{
196 int fd, err;
197
198 fd = mkstemp(temp_name);
199 if (fd < 0)
200 return -errno;
201
202 err = vdso__copy_compat(prog, fd);
203
204 if (close(fd) == -1)
205 return -errno;
206
207 return err;
208}
209
210static const char *vdso__get_compat_file(struct vdso_file *vdso_file)
211{
212 int err;
213
214 if (vdso_file->found)
215 return vdso_file->temp_file_name;
216
217 if (vdso_file->error)
218 return NULL;
219
220 err = vdso__create_compat_file(vdso_file->read_prog,
221 vdso_file->temp_file_name);
222 if (err) {
223 pr_err("%s failed, error %d\n", vdso_file->read_prog, err);
224 vdso_file->error = true;
225 return NULL;
226 }
227
228 vdso_file->found = true;
229
230 return vdso_file->temp_file_name;
231}
232
233static struct dso *__machine__findnew_compat(struct machine *machine,
234 struct vdso_file *vdso_file)
235{
236 const char *file_name;
237 struct dso *dso;
238
239 dso = __dsos__find(&machine->dsos, vdso_file->dso_name, true);
240 if (dso)
241 goto out;
242
243 file_name = vdso__get_compat_file(vdso_file);
244 if (!file_name)
245 goto out;
246
247 dso = __machine__addnew_vdso(machine, vdso_file->dso_name, file_name);
248out:
249 return dso;
250}
251
252static int __machine__findnew_vdso_compat(struct machine *machine,
253 struct thread *thread,
254 struct vdso_info *vdso_info,
255 struct dso **dso)
256{
257 enum dso_type dso_type;
258
259 dso_type = machine__thread_dso_type(machine, thread);
260
261#ifndef HAVE_PERF_READ_VDSO32
262 if (dso_type == DSO__TYPE_32BIT)
263 return 0;
264#endif
265#ifndef HAVE_PERF_READ_VDSOX32
266 if (dso_type == DSO__TYPE_X32BIT)
267 return 0;
268#endif
269
270 switch (dso_type) {
271 case DSO__TYPE_32BIT:
272 *dso = __machine__findnew_compat(machine, &vdso_info->vdso32);
273 return 1;
274 case DSO__TYPE_X32BIT:
275 *dso = __machine__findnew_compat(machine, &vdso_info->vdsox32);
276 return 1;
277 case DSO__TYPE_UNKNOWN:
278 case DSO__TYPE_64BIT:
279 default:
280 return 0;
281 }
282}
283
284#endif
285
286struct dso *machine__findnew_vdso(struct machine *machine,
287 struct thread *thread __maybe_unused)
288{
289 struct vdso_info *vdso_info;
290 struct dso *dso = NULL;
291
292 pthread_rwlock_wrlock(&machine->dsos.lock);
293 if (!machine->vdso_info)
294 machine->vdso_info = vdso_info__new();
295
296 vdso_info = machine->vdso_info;
297 if (!vdso_info)
298 goto out_unlock;
299
300#if BITS_PER_LONG == 64
301 if (__machine__findnew_vdso_compat(machine, thread, vdso_info, &dso))
302 goto out_unlock;
303#endif
304
305 dso = __dsos__find(&machine->dsos, DSO__NAME_VDSO, true);
306 if (!dso) {
307 char *file;
308
309 file = get_file(&vdso_info->vdso);
310 if (file)
311 dso = __machine__addnew_vdso(machine, DSO__NAME_VDSO, file);
312 }
313
314out_unlock:
315 dso__get(dso);
316 pthread_rwlock_unlock(&machine->dsos.lock);
317 return dso;
318}
319
320bool dso__is_vdso(struct dso *dso)
321{
322 return !strcmp(dso->short_name, DSO__NAME_VDSO) ||
323 !strcmp(dso->short_name, DSO__NAME_VDSO32) ||
324 !strcmp(dso->short_name, DSO__NAME_VDSOX32);
325}
1// SPDX-License-Identifier: GPL-2.0
2#include <errno.h>
3#include <unistd.h>
4#include <stdio.h>
5#include <string.h>
6#include <sys/types.h>
7#include <sys/stat.h>
8#include <fcntl.h>
9#include <stdlib.h>
10#include <linux/kernel.h>
11
12#include "vdso.h"
13#include "util.h"
14#include "symbol.h"
15#include "machine.h"
16#include "thread.h"
17#include "linux/string.h"
18#include "debug.h"
19
20/*
21 * Include definition of find_vdso_map() also used in perf-read-vdso.c for
22 * building perf-read-vdso32 and perf-read-vdsox32.
23 */
24#include "find-vdso-map.c"
25
26#define VDSO__TEMP_FILE_NAME "/tmp/perf-vdso.so-XXXXXX"
27
28struct vdso_file {
29 bool found;
30 bool error;
31 char temp_file_name[sizeof(VDSO__TEMP_FILE_NAME)];
32 const char *dso_name;
33 const char *read_prog;
34};
35
36struct vdso_info {
37 struct vdso_file vdso;
38#if BITS_PER_LONG == 64
39 struct vdso_file vdso32;
40 struct vdso_file vdsox32;
41#endif
42};
43
44static struct vdso_info *vdso_info__new(void)
45{
46 static const struct vdso_info vdso_info_init = {
47 .vdso = {
48 .temp_file_name = VDSO__TEMP_FILE_NAME,
49 .dso_name = DSO__NAME_VDSO,
50 },
51#if BITS_PER_LONG == 64
52 .vdso32 = {
53 .temp_file_name = VDSO__TEMP_FILE_NAME,
54 .dso_name = DSO__NAME_VDSO32,
55 .read_prog = "perf-read-vdso32",
56 },
57 .vdsox32 = {
58 .temp_file_name = VDSO__TEMP_FILE_NAME,
59 .dso_name = DSO__NAME_VDSOX32,
60 .read_prog = "perf-read-vdsox32",
61 },
62#endif
63 };
64
65 return memdup(&vdso_info_init, sizeof(vdso_info_init));
66}
67
68static char *get_file(struct vdso_file *vdso_file)
69{
70 char *vdso = NULL;
71 char *buf = NULL;
72 void *start, *end;
73 size_t size;
74 int fd;
75
76 if (vdso_file->found)
77 return vdso_file->temp_file_name;
78
79 if (vdso_file->error || find_vdso_map(&start, &end))
80 return NULL;
81
82 size = end - start;
83
84 buf = memdup(start, size);
85 if (!buf)
86 return NULL;
87
88 fd = mkstemp(vdso_file->temp_file_name);
89 if (fd < 0)
90 goto out;
91
92 if (size == (size_t) write(fd, buf, size))
93 vdso = vdso_file->temp_file_name;
94
95 close(fd);
96
97 out:
98 free(buf);
99
100 vdso_file->found = (vdso != NULL);
101 vdso_file->error = !vdso_file->found;
102 return vdso;
103}
104
105void machine__exit_vdso(struct machine *machine)
106{
107 struct vdso_info *vdso_info = machine->vdso_info;
108
109 if (!vdso_info)
110 return;
111
112 if (vdso_info->vdso.found)
113 unlink(vdso_info->vdso.temp_file_name);
114#if BITS_PER_LONG == 64
115 if (vdso_info->vdso32.found)
116 unlink(vdso_info->vdso32.temp_file_name);
117 if (vdso_info->vdsox32.found)
118 unlink(vdso_info->vdsox32.temp_file_name);
119#endif
120
121 zfree(&machine->vdso_info);
122}
123
124static struct dso *__machine__addnew_vdso(struct machine *machine, const char *short_name,
125 const char *long_name)
126{
127 struct dso *dso;
128
129 dso = dso__new(short_name);
130 if (dso != NULL) {
131 __dsos__add(&machine->dsos, dso);
132 dso__set_long_name(dso, long_name, false);
133 }
134
135 return dso;
136}
137
138static enum dso_type machine__thread_dso_type(struct machine *machine,
139 struct thread *thread)
140{
141 enum dso_type dso_type = DSO__TYPE_UNKNOWN;
142 struct map *map;
143 struct dso *dso;
144
145 map = map_groups__first(thread->mg, MAP__FUNCTION);
146 for (; map ; map = map_groups__next(map)) {
147 dso = map->dso;
148 if (!dso || dso->long_name[0] != '/')
149 continue;
150 dso_type = dso__type(dso, machine);
151 if (dso_type != DSO__TYPE_UNKNOWN)
152 break;
153 }
154
155 return dso_type;
156}
157
158#if BITS_PER_LONG == 64
159
160static int vdso__do_copy_compat(FILE *f, int fd)
161{
162 char buf[4096];
163 size_t count;
164
165 while (1) {
166 count = fread(buf, 1, sizeof(buf), f);
167 if (ferror(f))
168 return -errno;
169 if (feof(f))
170 break;
171 if (count && writen(fd, buf, count) != (ssize_t)count)
172 return -errno;
173 }
174
175 return 0;
176}
177
178static int vdso__copy_compat(const char *prog, int fd)
179{
180 FILE *f;
181 int err;
182
183 f = popen(prog, "r");
184 if (!f)
185 return -errno;
186
187 err = vdso__do_copy_compat(f, fd);
188
189 if (pclose(f) == -1)
190 return -errno;
191
192 return err;
193}
194
195static int vdso__create_compat_file(const char *prog, char *temp_name)
196{
197 int fd, err;
198
199 fd = mkstemp(temp_name);
200 if (fd < 0)
201 return -errno;
202
203 err = vdso__copy_compat(prog, fd);
204
205 if (close(fd) == -1)
206 return -errno;
207
208 return err;
209}
210
211static const char *vdso__get_compat_file(struct vdso_file *vdso_file)
212{
213 int err;
214
215 if (vdso_file->found)
216 return vdso_file->temp_file_name;
217
218 if (vdso_file->error)
219 return NULL;
220
221 err = vdso__create_compat_file(vdso_file->read_prog,
222 vdso_file->temp_file_name);
223 if (err) {
224 pr_err("%s failed, error %d\n", vdso_file->read_prog, err);
225 vdso_file->error = true;
226 return NULL;
227 }
228
229 vdso_file->found = true;
230
231 return vdso_file->temp_file_name;
232}
233
234static struct dso *__machine__findnew_compat(struct machine *machine,
235 struct vdso_file *vdso_file)
236{
237 const char *file_name;
238 struct dso *dso;
239
240 dso = __dsos__find(&machine->dsos, vdso_file->dso_name, true);
241 if (dso)
242 goto out;
243
244 file_name = vdso__get_compat_file(vdso_file);
245 if (!file_name)
246 goto out;
247
248 dso = __machine__addnew_vdso(machine, vdso_file->dso_name, file_name);
249out:
250 return dso;
251}
252
253static int __machine__findnew_vdso_compat(struct machine *machine,
254 struct thread *thread,
255 struct vdso_info *vdso_info,
256 struct dso **dso)
257{
258 enum dso_type dso_type;
259
260 dso_type = machine__thread_dso_type(machine, thread);
261
262#ifndef HAVE_PERF_READ_VDSO32
263 if (dso_type == DSO__TYPE_32BIT)
264 return 0;
265#endif
266#ifndef HAVE_PERF_READ_VDSOX32
267 if (dso_type == DSO__TYPE_X32BIT)
268 return 0;
269#endif
270
271 switch (dso_type) {
272 case DSO__TYPE_32BIT:
273 *dso = __machine__findnew_compat(machine, &vdso_info->vdso32);
274 return 1;
275 case DSO__TYPE_X32BIT:
276 *dso = __machine__findnew_compat(machine, &vdso_info->vdsox32);
277 return 1;
278 case DSO__TYPE_UNKNOWN:
279 case DSO__TYPE_64BIT:
280 default:
281 return 0;
282 }
283}
284
285#endif
286
287static struct dso *machine__find_vdso(struct machine *machine,
288 struct thread *thread)
289{
290 struct dso *dso = NULL;
291 enum dso_type dso_type;
292
293 dso_type = machine__thread_dso_type(machine, thread);
294 switch (dso_type) {
295 case DSO__TYPE_32BIT:
296 dso = __dsos__find(&machine->dsos, DSO__NAME_VDSO32, true);
297 if (!dso) {
298 dso = __dsos__find(&machine->dsos, DSO__NAME_VDSO,
299 true);
300 if (dso && dso_type != dso__type(dso, machine))
301 dso = NULL;
302 }
303 break;
304 case DSO__TYPE_X32BIT:
305 dso = __dsos__find(&machine->dsos, DSO__NAME_VDSOX32, true);
306 break;
307 case DSO__TYPE_64BIT:
308 case DSO__TYPE_UNKNOWN:
309 default:
310 dso = __dsos__find(&machine->dsos, DSO__NAME_VDSO, true);
311 break;
312 }
313
314 return dso;
315}
316
317struct dso *machine__findnew_vdso(struct machine *machine,
318 struct thread *thread)
319{
320 struct vdso_info *vdso_info;
321 struct dso *dso = NULL;
322
323 down_write(&machine->dsos.lock);
324 if (!machine->vdso_info)
325 machine->vdso_info = vdso_info__new();
326
327 vdso_info = machine->vdso_info;
328 if (!vdso_info)
329 goto out_unlock;
330
331 dso = machine__find_vdso(machine, thread);
332 if (dso)
333 goto out_unlock;
334
335#if BITS_PER_LONG == 64
336 if (__machine__findnew_vdso_compat(machine, thread, vdso_info, &dso))
337 goto out_unlock;
338#endif
339
340 dso = __dsos__find(&machine->dsos, DSO__NAME_VDSO, true);
341 if (!dso) {
342 char *file;
343
344 file = get_file(&vdso_info->vdso);
345 if (file)
346 dso = __machine__addnew_vdso(machine, DSO__NAME_VDSO, file);
347 }
348
349out_unlock:
350 dso__get(dso);
351 up_write(&machine->dsos.lock);
352 return dso;
353}
354
355bool dso__is_vdso(struct dso *dso)
356{
357 return !strcmp(dso->short_name, DSO__NAME_VDSO) ||
358 !strcmp(dso->short_name, DSO__NAME_VDSO32) ||
359 !strcmp(dso->short_name, DSO__NAME_VDSOX32);
360}