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7c97f91e MM |
1 | /* Linux-dependent part of branch trace support for GDB, and GDBserver. |
2 | ||
32d0add0 | 3 | Copyright (C) 2013-2015 Free Software Foundation, Inc. |
7c97f91e MM |
4 | |
5 | Contributed by Intel Corp. <markus.t.metzger@intel.com> | |
6 | ||
7 | This file is part of GDB. | |
8 | ||
9 | This program is free software; you can redistribute it and/or modify | |
10 | it under the terms of the GNU General Public License as published by | |
11 | the Free Software Foundation; either version 3 of the License, or | |
12 | (at your option) any later version. | |
13 | ||
14 | This program is distributed in the hope that it will be useful, | |
15 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
16 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
17 | GNU General Public License for more details. | |
18 | ||
19 | You should have received a copy of the GNU General Public License | |
20 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ | |
21 | ||
53f81362 | 22 | #include "common-defs.h" |
7c97f91e | 23 | #include "linux-btrace.h" |
361c8ade | 24 | #include "common-regcache.h" |
be8b1ea6 | 25 | #include "gdb_wait.h" |
df7e5265 | 26 | #include "x86-cpuid.h" |
0568462b MM |
27 | #include "filestuff.h" |
28 | ||
29 | #include <inttypes.h> | |
7c97f91e | 30 | |
5b4e221c MF |
31 | #ifdef HAVE_SYS_SYSCALL_H |
32 | #include <sys/syscall.h> | |
33 | #endif | |
34 | ||
35 | #if HAVE_LINUX_PERF_EVENT_H && defined(SYS_perf_event_open) | |
7c97f91e | 36 | #include <unistd.h> |
7c97f91e MM |
37 | #include <sys/mman.h> |
38 | #include <sys/user.h> | |
5826e159 | 39 | #include "nat/gdb_ptrace.h" |
a950d57c | 40 | #include <sys/types.h> |
a950d57c | 41 | #include <signal.h> |
7c97f91e MM |
42 | |
43 | /* A branch trace record in perf_event. */ | |
44 | struct perf_event_bts | |
45 | { | |
46 | /* The linear address of the branch source. */ | |
47 | uint64_t from; | |
48 | ||
49 | /* The linear address of the branch destination. */ | |
50 | uint64_t to; | |
51 | }; | |
52 | ||
53 | /* A perf_event branch trace sample. */ | |
54 | struct perf_event_sample | |
55 | { | |
56 | /* The perf_event sample header. */ | |
57 | struct perf_event_header header; | |
58 | ||
59 | /* The perf_event branch tracing payload. */ | |
60 | struct perf_event_bts bts; | |
61 | }; | |
62 | ||
afb778a2 MM |
63 | /* Identify the cpu we're running on. */ |
64 | static struct btrace_cpu | |
65 | btrace_this_cpu (void) | |
66 | { | |
67 | struct btrace_cpu cpu; | |
68 | unsigned int eax, ebx, ecx, edx; | |
69 | int ok; | |
70 | ||
71 | memset (&cpu, 0, sizeof (cpu)); | |
72 | ||
73 | ok = x86_cpuid (0, &eax, &ebx, &ecx, &edx); | |
74 | if (ok != 0) | |
75 | { | |
76 | if (ebx == signature_INTEL_ebx && ecx == signature_INTEL_ecx | |
77 | && edx == signature_INTEL_edx) | |
78 | { | |
79 | unsigned int cpuid, ignore; | |
80 | ||
81 | ok = x86_cpuid (1, &cpuid, &ignore, &ignore, &ignore); | |
82 | if (ok != 0) | |
83 | { | |
84 | cpu.vendor = CV_INTEL; | |
85 | ||
86 | cpu.family = (cpuid >> 8) & 0xf; | |
87 | cpu.model = (cpuid >> 4) & 0xf; | |
88 | ||
89 | if (cpu.family == 0x6) | |
90 | cpu.model += (cpuid >> 12) & 0xf0; | |
91 | } | |
92 | } | |
93 | } | |
94 | ||
95 | return cpu; | |
96 | } | |
97 | ||
aadf7753 | 98 | /* Return non-zero if there is new data in PEVENT; zero otherwise. */ |
7c97f91e | 99 | |
aadf7753 MM |
100 | static int |
101 | perf_event_new_data (const struct perf_event_buffer *pev) | |
7c97f91e | 102 | { |
aadf7753 | 103 | return *pev->data_head != pev->last_head; |
7c97f91e MM |
104 | } |
105 | ||
d68e53f4 MM |
106 | /* Try to determine the size of a pointer in bits for the OS. |
107 | ||
108 | This is the same as the size of a pointer for the inferior process | |
109 | except when a 32-bit inferior is running on a 64-bit OS. */ | |
110 | ||
b20a6524 MM |
111 | /* Copy the last SIZE bytes from PEV ending at DATA_HEAD and return a pointer |
112 | to the memory holding the copy. | |
113 | The caller is responsible for freeing the memory. */ | |
114 | ||
115 | static gdb_byte * | |
e7b01ce0 MM |
116 | perf_event_read (const struct perf_event_buffer *pev, __u64 data_head, |
117 | size_t size) | |
b20a6524 MM |
118 | { |
119 | const gdb_byte *begin, *end, *start, *stop; | |
120 | gdb_byte *buffer; | |
e7b01ce0 MM |
121 | size_t buffer_size; |
122 | __u64 data_tail; | |
b20a6524 MM |
123 | |
124 | if (size == 0) | |
125 | return NULL; | |
126 | ||
127 | gdb_assert (size <= data_head); | |
128 | data_tail = data_head - size; | |
129 | ||
130 | buffer_size = pev->size; | |
131 | begin = pev->mem; | |
132 | start = begin + data_tail % buffer_size; | |
133 | stop = begin + data_head % buffer_size; | |
134 | ||
224c3ddb | 135 | buffer = (gdb_byte *) xmalloc (size); |
b20a6524 MM |
136 | |
137 | if (start < stop) | |
138 | memcpy (buffer, start, stop - start); | |
139 | else | |
140 | { | |
141 | end = begin + buffer_size; | |
142 | ||
143 | memcpy (buffer, start, end - start); | |
144 | memcpy (buffer + (end - start), begin, stop - begin); | |
145 | } | |
146 | ||
147 | return buffer; | |
148 | } | |
149 | ||
150 | /* Copy the perf event buffer data from PEV. | |
151 | Store a pointer to the copy into DATA and its size in SIZE. */ | |
152 | ||
153 | static void | |
154 | perf_event_read_all (struct perf_event_buffer *pev, gdb_byte **data, | |
e7b01ce0 | 155 | size_t *psize) |
b20a6524 | 156 | { |
e7b01ce0 MM |
157 | size_t size; |
158 | __u64 data_head; | |
b20a6524 MM |
159 | |
160 | data_head = *pev->data_head; | |
161 | ||
162 | size = pev->size; | |
163 | if (data_head < size) | |
e7b01ce0 | 164 | size = (size_t) data_head; |
b20a6524 MM |
165 | |
166 | *data = perf_event_read (pev, data_head, size); | |
167 | *psize = size; | |
168 | ||
169 | pev->last_head = data_head; | |
170 | } | |
171 | ||
172 | /* Determine the event type. | |
173 | Returns zero on success and fills in TYPE; returns -1 otherwise. */ | |
174 | ||
175 | static int | |
176 | perf_event_pt_event_type (int *type) | |
177 | { | |
178 | FILE *file; | |
179 | int found; | |
180 | ||
181 | file = fopen ("/sys/bus/event_source/devices/intel_pt/type", "r"); | |
182 | if (file == NULL) | |
183 | return -1; | |
184 | ||
185 | found = fscanf (file, "%d", type); | |
186 | ||
187 | fclose (file); | |
188 | ||
189 | if (found == 1) | |
190 | return 0; | |
191 | return -1; | |
192 | } | |
193 | ||
0568462b MM |
194 | /* Try to determine the start address of the Linux kernel. */ |
195 | ||
196 | static uint64_t | |
197 | linux_determine_kernel_start (void) | |
d68e53f4 | 198 | { |
0568462b MM |
199 | static uint64_t kernel_start; |
200 | static int cached; | |
201 | FILE *file; | |
d68e53f4 | 202 | |
0568462b MM |
203 | if (cached != 0) |
204 | return kernel_start; | |
d68e53f4 | 205 | |
0568462b MM |
206 | cached = 1; |
207 | ||
208 | file = gdb_fopen_cloexec ("/proc/kallsyms", "r"); | |
209 | if (file == NULL) | |
210 | return kernel_start; | |
211 | ||
212 | while (!feof (file)) | |
213 | { | |
214 | char buffer[1024], symbol[8], *line; | |
215 | uint64_t addr; | |
216 | int match; | |
217 | ||
218 | line = fgets (buffer, sizeof (buffer), file); | |
219 | if (line == NULL) | |
220 | break; | |
d68e53f4 | 221 | |
0568462b MM |
222 | match = sscanf (line, "%" SCNx64 " %*[tT] %7s", &addr, symbol); |
223 | if (match != 2) | |
224 | continue; | |
d68e53f4 | 225 | |
0568462b MM |
226 | if (strcmp (symbol, "_text") == 0) |
227 | { | |
228 | kernel_start = addr; | |
229 | break; | |
230 | } | |
231 | } | |
232 | ||
233 | fclose (file); | |
234 | ||
235 | return kernel_start; | |
d68e53f4 MM |
236 | } |
237 | ||
7c97f91e MM |
238 | /* Check whether an address is in the kernel. */ |
239 | ||
240 | static inline int | |
0568462b | 241 | perf_event_is_kernel_addr (uint64_t addr) |
7c97f91e | 242 | { |
0568462b | 243 | uint64_t kernel_start; |
7c97f91e | 244 | |
0568462b MM |
245 | kernel_start = linux_determine_kernel_start (); |
246 | if (kernel_start != 0ull) | |
247 | return (addr >= kernel_start); | |
7c97f91e | 248 | |
0568462b MM |
249 | /* If we don't know the kernel's start address, let's check the most |
250 | significant bit. This will work at least for 64-bit kernels. */ | |
251 | return ((addr & (1ull << 63)) != 0); | |
7c97f91e MM |
252 | } |
253 | ||
254 | /* Check whether a perf event record should be skipped. */ | |
255 | ||
256 | static inline int | |
0568462b | 257 | perf_event_skip_bts_record (const struct perf_event_bts *bts) |
7c97f91e MM |
258 | { |
259 | /* The hardware may report branches from kernel into user space. Branches | |
260 | from user into kernel space will be suppressed. We filter the former to | |
261 | provide a consistent branch trace excluding kernel. */ | |
0568462b | 262 | return perf_event_is_kernel_addr (bts->from); |
7c97f91e MM |
263 | } |
264 | ||
265 | /* Perform a few consistency checks on a perf event sample record. This is | |
266 | meant to catch cases when we get out of sync with the perf event stream. */ | |
267 | ||
268 | static inline int | |
269 | perf_event_sample_ok (const struct perf_event_sample *sample) | |
270 | { | |
271 | if (sample->header.type != PERF_RECORD_SAMPLE) | |
272 | return 0; | |
273 | ||
274 | if (sample->header.size != sizeof (*sample)) | |
275 | return 0; | |
276 | ||
277 | return 1; | |
278 | } | |
279 | ||
280 | /* Branch trace is collected in a circular buffer [begin; end) as pairs of from | |
281 | and to addresses (plus a header). | |
282 | ||
283 | Start points into that buffer at the next sample position. | |
284 | We read the collected samples backwards from start. | |
285 | ||
286 | While reading the samples, we convert the information into a list of blocks. | |
287 | For two adjacent samples s1 and s2, we form a block b such that b.begin = | |
288 | s1.to and b.end = s2.from. | |
289 | ||
290 | In case the buffer overflows during sampling, one sample may have its lower | |
291 | part at the end and its upper part at the beginning of the buffer. */ | |
292 | ||
293 | static VEC (btrace_block_s) * | |
294 | perf_event_read_bts (struct btrace_target_info* tinfo, const uint8_t *begin, | |
e7b01ce0 | 295 | const uint8_t *end, const uint8_t *start, size_t size) |
7c97f91e MM |
296 | { |
297 | VEC (btrace_block_s) *btrace = NULL; | |
298 | struct perf_event_sample sample; | |
e7b01ce0 | 299 | size_t read = 0; |
7c97f91e MM |
300 | struct btrace_block block = { 0, 0 }; |
301 | struct regcache *regcache; | |
302 | ||
303 | gdb_assert (begin <= start); | |
304 | gdb_assert (start <= end); | |
305 | ||
306 | /* The first block ends at the current pc. */ | |
361c8ade | 307 | regcache = get_thread_regcache_for_ptid (tinfo->ptid); |
7c97f91e MM |
308 | block.end = regcache_read_pc (regcache); |
309 | ||
310 | /* The buffer may contain a partial record as its last entry (i.e. when the | |
311 | buffer size is not a multiple of the sample size). */ | |
312 | read = sizeof (sample) - 1; | |
313 | ||
314 | for (; read < size; read += sizeof (sample)) | |
315 | { | |
316 | const struct perf_event_sample *psample; | |
317 | ||
318 | /* Find the next perf_event sample in a backwards traversal. */ | |
319 | start -= sizeof (sample); | |
320 | ||
321 | /* If we're still inside the buffer, we're done. */ | |
322 | if (begin <= start) | |
323 | psample = (const struct perf_event_sample *) start; | |
324 | else | |
325 | { | |
326 | int missing; | |
327 | ||
328 | /* We're to the left of the ring buffer, we will wrap around and | |
329 | reappear at the very right of the ring buffer. */ | |
330 | ||
331 | missing = (begin - start); | |
332 | start = (end - missing); | |
333 | ||
334 | /* If the entire sample is missing, we're done. */ | |
335 | if (missing == sizeof (sample)) | |
336 | psample = (const struct perf_event_sample *) start; | |
337 | else | |
338 | { | |
339 | uint8_t *stack; | |
340 | ||
341 | /* The sample wrapped around. The lower part is at the end and | |
342 | the upper part is at the beginning of the buffer. */ | |
343 | stack = (uint8_t *) &sample; | |
344 | ||
345 | /* Copy the two parts so we have a contiguous sample. */ | |
346 | memcpy (stack, start, missing); | |
347 | memcpy (stack + missing, begin, sizeof (sample) - missing); | |
348 | ||
349 | psample = &sample; | |
350 | } | |
351 | } | |
352 | ||
353 | if (!perf_event_sample_ok (psample)) | |
354 | { | |
355 | warning (_("Branch trace may be incomplete.")); | |
356 | break; | |
357 | } | |
358 | ||
0568462b | 359 | if (perf_event_skip_bts_record (&psample->bts)) |
7c97f91e MM |
360 | continue; |
361 | ||
362 | /* We found a valid sample, so we can complete the current block. */ | |
363 | block.begin = psample->bts.to; | |
364 | ||
365 | VEC_safe_push (btrace_block_s, btrace, &block); | |
366 | ||
367 | /* Start the next block. */ | |
368 | block.end = psample->bts.from; | |
369 | } | |
370 | ||
969c39fb MM |
371 | /* Push the last block (i.e. the first one of inferior execution), as well. |
372 | We don't know where it ends, but we know where it starts. If we're | |
373 | reading delta trace, we can fill in the start address later on. | |
374 | Otherwise we will prune it. */ | |
375 | block.begin = 0; | |
376 | VEC_safe_push (btrace_block_s, btrace, &block); | |
377 | ||
7c97f91e MM |
378 | return btrace; |
379 | } | |
380 | ||
043c3577 | 381 | /* Check whether the kernel supports BTS. */ |
a950d57c MM |
382 | |
383 | static int | |
043c3577 | 384 | kernel_supports_bts (void) |
a950d57c MM |
385 | { |
386 | struct perf_event_attr attr; | |
387 | pid_t child, pid; | |
388 | int status, file; | |
389 | ||
390 | errno = 0; | |
391 | child = fork (); | |
392 | switch (child) | |
393 | { | |
394 | case -1: | |
76fb6829 | 395 | warning (_("test bts: cannot fork: %s."), safe_strerror (errno)); |
a950d57c MM |
396 | return 0; |
397 | ||
398 | case 0: | |
399 | status = ptrace (PTRACE_TRACEME, 0, NULL, NULL); | |
400 | if (status != 0) | |
401 | { | |
043c3577 | 402 | warning (_("test bts: cannot PTRACE_TRACEME: %s."), |
76fb6829 | 403 | safe_strerror (errno)); |
a950d57c MM |
404 | _exit (1); |
405 | } | |
406 | ||
407 | status = raise (SIGTRAP); | |
408 | if (status != 0) | |
409 | { | |
043c3577 | 410 | warning (_("test bts: cannot raise SIGTRAP: %s."), |
76fb6829 | 411 | safe_strerror (errno)); |
a950d57c MM |
412 | _exit (1); |
413 | } | |
414 | ||
415 | _exit (1); | |
416 | ||
417 | default: | |
418 | pid = waitpid (child, &status, 0); | |
419 | if (pid != child) | |
420 | { | |
043c3577 | 421 | warning (_("test bts: bad pid %ld, error: %s."), |
76fb6829 | 422 | (long) pid, safe_strerror (errno)); |
a950d57c MM |
423 | return 0; |
424 | } | |
425 | ||
426 | if (!WIFSTOPPED (status)) | |
427 | { | |
043c3577 | 428 | warning (_("test bts: expected stop. status: %d."), |
a950d57c MM |
429 | status); |
430 | return 0; | |
431 | } | |
432 | ||
433 | memset (&attr, 0, sizeof (attr)); | |
434 | ||
435 | attr.type = PERF_TYPE_HARDWARE; | |
436 | attr.config = PERF_COUNT_HW_BRANCH_INSTRUCTIONS; | |
437 | attr.sample_period = 1; | |
438 | attr.sample_type = PERF_SAMPLE_IP | PERF_SAMPLE_ADDR; | |
439 | attr.exclude_kernel = 1; | |
440 | attr.exclude_hv = 1; | |
441 | attr.exclude_idle = 1; | |
442 | ||
443 | file = syscall (SYS_perf_event_open, &attr, child, -1, -1, 0); | |
444 | if (file >= 0) | |
445 | close (file); | |
446 | ||
447 | kill (child, SIGKILL); | |
448 | ptrace (PTRACE_KILL, child, NULL, NULL); | |
449 | ||
450 | pid = waitpid (child, &status, 0); | |
451 | if (pid != child) | |
452 | { | |
043c3577 | 453 | warning (_("test bts: bad pid %ld, error: %s."), |
76fb6829 | 454 | (long) pid, safe_strerror (errno)); |
a950d57c | 455 | if (!WIFSIGNALED (status)) |
043c3577 | 456 | warning (_("test bts: expected killed. status: %d."), |
a950d57c MM |
457 | status); |
458 | } | |
459 | ||
460 | return (file >= 0); | |
461 | } | |
462 | } | |
463 | ||
b20a6524 MM |
464 | /* Check whether the kernel supports Intel(R) Processor Trace. */ |
465 | ||
466 | static int | |
467 | kernel_supports_pt (void) | |
468 | { | |
469 | struct perf_event_attr attr; | |
470 | pid_t child, pid; | |
471 | int status, file, type; | |
472 | ||
473 | errno = 0; | |
474 | child = fork (); | |
475 | switch (child) | |
476 | { | |
477 | case -1: | |
76fb6829 | 478 | warning (_("test pt: cannot fork: %s."), safe_strerror (errno)); |
b20a6524 MM |
479 | return 0; |
480 | ||
481 | case 0: | |
482 | status = ptrace (PTRACE_TRACEME, 0, NULL, NULL); | |
483 | if (status != 0) | |
484 | { | |
485 | warning (_("test pt: cannot PTRACE_TRACEME: %s."), | |
76fb6829 | 486 | safe_strerror (errno)); |
b20a6524 MM |
487 | _exit (1); |
488 | } | |
489 | ||
490 | status = raise (SIGTRAP); | |
491 | if (status != 0) | |
492 | { | |
493 | warning (_("test pt: cannot raise SIGTRAP: %s."), | |
76fb6829 | 494 | safe_strerror (errno)); |
b20a6524 MM |
495 | _exit (1); |
496 | } | |
497 | ||
498 | _exit (1); | |
499 | ||
500 | default: | |
501 | pid = waitpid (child, &status, 0); | |
502 | if (pid != child) | |
503 | { | |
504 | warning (_("test pt: bad pid %ld, error: %s."), | |
76fb6829 | 505 | (long) pid, safe_strerror (errno)); |
b20a6524 MM |
506 | return 0; |
507 | } | |
508 | ||
509 | if (!WIFSTOPPED (status)) | |
510 | { | |
511 | warning (_("test pt: expected stop. status: %d."), | |
512 | status); | |
513 | return 0; | |
514 | } | |
515 | ||
516 | status = perf_event_pt_event_type (&type); | |
517 | if (status != 0) | |
518 | file = -1; | |
519 | else | |
520 | { | |
521 | memset (&attr, 0, sizeof (attr)); | |
522 | ||
523 | attr.size = sizeof (attr); | |
524 | attr.type = type; | |
525 | attr.exclude_kernel = 1; | |
526 | attr.exclude_hv = 1; | |
527 | attr.exclude_idle = 1; | |
528 | ||
529 | file = syscall (SYS_perf_event_open, &attr, child, -1, -1, 0); | |
530 | if (file >= 0) | |
531 | close (file); | |
532 | } | |
533 | ||
534 | kill (child, SIGKILL); | |
535 | ptrace (PTRACE_KILL, child, NULL, NULL); | |
536 | ||
537 | pid = waitpid (child, &status, 0); | |
538 | if (pid != child) | |
539 | { | |
540 | warning (_("test pt: bad pid %ld, error: %s."), | |
76fb6829 | 541 | (long) pid, safe_strerror (errno)); |
b20a6524 MM |
542 | if (!WIFSIGNALED (status)) |
543 | warning (_("test pt: expected killed. status: %d."), | |
544 | status); | |
545 | } | |
546 | ||
547 | return (file >= 0); | |
548 | } | |
549 | } | |
550 | ||
043c3577 | 551 | /* Check whether an Intel cpu supports BTS. */ |
a950d57c MM |
552 | |
553 | static int | |
afb778a2 | 554 | intel_supports_bts (const struct btrace_cpu *cpu) |
a950d57c | 555 | { |
afb778a2 | 556 | switch (cpu->family) |
5f8e0b8f MF |
557 | { |
558 | case 0x6: | |
afb778a2 | 559 | switch (cpu->model) |
5f8e0b8f MF |
560 | { |
561 | case 0x1a: /* Nehalem */ | |
562 | case 0x1f: | |
563 | case 0x1e: | |
564 | case 0x2e: | |
565 | case 0x25: /* Westmere */ | |
566 | case 0x2c: | |
567 | case 0x2f: | |
568 | case 0x2a: /* Sandy Bridge */ | |
569 | case 0x2d: | |
570 | case 0x3a: /* Ivy Bridge */ | |
571 | ||
572 | /* AAJ122: LBR, BTM, or BTS records may have incorrect branch | |
573 | "from" information afer an EIST transition, T-states, C1E, or | |
574 | Adaptive Thermal Throttling. */ | |
575 | return 0; | |
576 | } | |
577 | } | |
a950d57c MM |
578 | |
579 | return 1; | |
a950d57c MM |
580 | } |
581 | ||
043c3577 | 582 | /* Check whether the cpu supports BTS. */ |
a950d57c MM |
583 | |
584 | static int | |
043c3577 | 585 | cpu_supports_bts (void) |
a950d57c | 586 | { |
afb778a2 | 587 | struct btrace_cpu cpu; |
a950d57c | 588 | |
afb778a2 MM |
589 | cpu = btrace_this_cpu (); |
590 | switch (cpu.vendor) | |
591 | { | |
592 | default: | |
593 | /* Don't know about others. Let's assume they do. */ | |
594 | return 1; | |
a950d57c | 595 | |
afb778a2 MM |
596 | case CV_INTEL: |
597 | return intel_supports_bts (&cpu); | |
598 | } | |
a950d57c MM |
599 | } |
600 | ||
043c3577 | 601 | /* Check whether the linux target supports BTS. */ |
7c97f91e | 602 | |
043c3577 MM |
603 | static int |
604 | linux_supports_bts (void) | |
7c97f91e | 605 | { |
a950d57c MM |
606 | static int cached; |
607 | ||
608 | if (cached == 0) | |
609 | { | |
043c3577 | 610 | if (!kernel_supports_bts ()) |
a950d57c | 611 | cached = -1; |
043c3577 | 612 | else if (!cpu_supports_bts ()) |
a950d57c MM |
613 | cached = -1; |
614 | else | |
615 | cached = 1; | |
616 | } | |
617 | ||
618 | return cached > 0; | |
7c97f91e MM |
619 | } |
620 | ||
b20a6524 MM |
621 | /* Check whether the linux target supports Intel(R) Processor Trace. */ |
622 | ||
623 | static int | |
624 | linux_supports_pt (void) | |
625 | { | |
626 | static int cached; | |
627 | ||
628 | if (cached == 0) | |
629 | { | |
630 | if (!kernel_supports_pt ()) | |
631 | cached = -1; | |
632 | else | |
633 | cached = 1; | |
634 | } | |
635 | ||
636 | return cached > 0; | |
637 | } | |
638 | ||
7c97f91e MM |
639 | /* See linux-btrace.h. */ |
640 | ||
043c3577 MM |
641 | int |
642 | linux_supports_btrace (struct target_ops *ops, enum btrace_format format) | |
643 | { | |
644 | switch (format) | |
645 | { | |
646 | case BTRACE_FORMAT_NONE: | |
647 | return 0; | |
648 | ||
649 | case BTRACE_FORMAT_BTS: | |
650 | return linux_supports_bts (); | |
b20a6524 MM |
651 | |
652 | case BTRACE_FORMAT_PT: | |
653 | return linux_supports_pt (); | |
043c3577 MM |
654 | } |
655 | ||
656 | internal_error (__FILE__, __LINE__, _("Unknown branch trace format")); | |
657 | } | |
658 | ||
f4abbc16 | 659 | /* Enable branch tracing in BTS format. */ |
043c3577 | 660 | |
f4abbc16 | 661 | static struct btrace_target_info * |
d33501a5 | 662 | linux_enable_bts (ptid_t ptid, const struct btrace_config_bts *conf) |
7c97f91e | 663 | { |
aadf7753 | 664 | struct perf_event_mmap_page *header; |
7c97f91e | 665 | struct btrace_target_info *tinfo; |
f4abbc16 | 666 | struct btrace_tinfo_bts *bts; |
e7b01ce0 MM |
667 | size_t size, pages; |
668 | __u64 data_offset; | |
d0fa7535 | 669 | int pid, pg; |
7c97f91e | 670 | |
8d749320 | 671 | tinfo = XCNEW (struct btrace_target_info); |
7c97f91e MM |
672 | tinfo->ptid = ptid; |
673 | ||
f4abbc16 MM |
674 | tinfo->conf.format = BTRACE_FORMAT_BTS; |
675 | bts = &tinfo->variant.bts; | |
7c97f91e | 676 | |
f4abbc16 MM |
677 | bts->attr.size = sizeof (bts->attr); |
678 | bts->attr.type = PERF_TYPE_HARDWARE; | |
679 | bts->attr.config = PERF_COUNT_HW_BRANCH_INSTRUCTIONS; | |
680 | bts->attr.sample_period = 1; | |
7c97f91e | 681 | |
f4abbc16 MM |
682 | /* We sample from and to address. */ |
683 | bts->attr.sample_type = PERF_SAMPLE_IP | PERF_SAMPLE_ADDR; | |
7c97f91e | 684 | |
f4abbc16 MM |
685 | bts->attr.exclude_kernel = 1; |
686 | bts->attr.exclude_hv = 1; | |
687 | bts->attr.exclude_idle = 1; | |
7c97f91e MM |
688 | |
689 | pid = ptid_get_lwp (ptid); | |
690 | if (pid == 0) | |
691 | pid = ptid_get_pid (ptid); | |
692 | ||
693 | errno = 0; | |
f4abbc16 MM |
694 | bts->file = syscall (SYS_perf_event_open, &bts->attr, pid, -1, -1, 0); |
695 | if (bts->file < 0) | |
b20a6524 | 696 | goto err_out; |
7c97f91e | 697 | |
d33501a5 | 698 | /* Convert the requested size in bytes to pages (rounding up). */ |
e7b01ce0 MM |
699 | pages = ((size_t) conf->size / PAGE_SIZE |
700 | + ((conf->size % PAGE_SIZE) == 0 ? 0 : 1)); | |
d33501a5 MM |
701 | /* We need at least one page. */ |
702 | if (pages == 0) | |
703 | pages = 1; | |
704 | ||
705 | /* The buffer size can be requested in powers of two pages. Adjust PAGES | |
706 | to the next power of two. */ | |
e7b01ce0 MM |
707 | for (pg = 0; pages != ((size_t) 1 << pg); ++pg) |
708 | if ((pages & ((size_t) 1 << pg)) != 0) | |
709 | pages += ((size_t) 1 << pg); | |
d33501a5 MM |
710 | |
711 | /* We try to allocate the requested size. | |
712 | If that fails, try to get as much as we can. */ | |
713 | for (; pages > 0; pages >>= 1) | |
d0fa7535 | 714 | { |
d33501a5 | 715 | size_t length; |
e7b01ce0 | 716 | __u64 data_size; |
d33501a5 | 717 | |
e7b01ce0 MM |
718 | data_size = (__u64) pages * PAGE_SIZE; |
719 | ||
720 | /* Don't ask for more than we can represent in the configuration. */ | |
721 | if ((__u64) UINT_MAX < data_size) | |
722 | continue; | |
723 | ||
724 | size = (size_t) data_size; | |
d33501a5 MM |
725 | length = size + PAGE_SIZE; |
726 | ||
727 | /* Check for overflows. */ | |
e7b01ce0 | 728 | if ((__u64) length != data_size + PAGE_SIZE) |
d33501a5 MM |
729 | continue; |
730 | ||
d0fa7535 | 731 | /* The number of pages we request needs to be a power of two. */ |
224c3ddb SM |
732 | header = ((struct perf_event_mmap_page *) |
733 | mmap (NULL, length, PROT_READ, MAP_SHARED, bts->file, 0)); | |
aadf7753 MM |
734 | if (header != MAP_FAILED) |
735 | break; | |
d0fa7535 | 736 | } |
7c97f91e | 737 | |
010a18a1 | 738 | if (pages == 0) |
aadf7753 MM |
739 | goto err_file; |
740 | ||
010a18a1 | 741 | data_offset = PAGE_SIZE; |
010a18a1 MM |
742 | |
743 | #if defined (PERF_ATTR_SIZE_VER5) | |
744 | if (offsetof (struct perf_event_mmap_page, data_size) <= header->size) | |
745 | { | |
e7b01ce0 MM |
746 | __u64 data_size; |
747 | ||
010a18a1 MM |
748 | data_offset = header->data_offset; |
749 | data_size = header->data_size; | |
e7b01ce0 MM |
750 | |
751 | size = (unsigned int) data_size; | |
752 | ||
753 | /* Check for overflows. */ | |
754 | if ((__u64) size != data_size) | |
755 | { | |
756 | munmap ((void *) header, size + PAGE_SIZE); | |
757 | goto err_file; | |
758 | } | |
010a18a1 MM |
759 | } |
760 | #endif /* defined (PERF_ATTR_SIZE_VER5) */ | |
761 | ||
f4abbc16 | 762 | bts->header = header; |
010a18a1 | 763 | bts->bts.mem = ((const uint8_t *) header) + data_offset; |
e7b01ce0 | 764 | bts->bts.size = size; |
f4abbc16 | 765 | bts->bts.data_head = &header->data_head; |
e7b01ce0 | 766 | bts->bts.last_head = 0ull; |
aadf7753 | 767 | |
e7b01ce0 | 768 | tinfo->conf.bts.size = (unsigned int) size; |
aadf7753 MM |
769 | return tinfo; |
770 | ||
771 | err_file: | |
d0fa7535 | 772 | /* We were not able to allocate any buffer. */ |
f4abbc16 | 773 | close (bts->file); |
7c97f91e | 774 | |
b20a6524 MM |
775 | err_out: |
776 | xfree (tinfo); | |
777 | return NULL; | |
778 | } | |
779 | ||
780 | #if defined (PERF_ATTR_SIZE_VER5) | |
781 | ||
782 | /* Enable branch tracing in Intel(R) Processor Trace format. */ | |
783 | ||
784 | static struct btrace_target_info * | |
785 | linux_enable_pt (ptid_t ptid, const struct btrace_config_pt *conf) | |
786 | { | |
787 | struct perf_event_mmap_page *header; | |
788 | struct btrace_target_info *tinfo; | |
789 | struct btrace_tinfo_pt *pt; | |
e7b01ce0 | 790 | size_t pages, size; |
b20a6524 MM |
791 | int pid, pg, errcode, type; |
792 | ||
793 | if (conf->size == 0) | |
794 | return NULL; | |
795 | ||
796 | errcode = perf_event_pt_event_type (&type); | |
797 | if (errcode != 0) | |
798 | return NULL; | |
799 | ||
800 | pid = ptid_get_lwp (ptid); | |
801 | if (pid == 0) | |
802 | pid = ptid_get_pid (ptid); | |
803 | ||
8d749320 | 804 | tinfo = XCNEW (struct btrace_target_info); |
b20a6524 | 805 | tinfo->ptid = ptid; |
b20a6524 MM |
806 | |
807 | tinfo->conf.format = BTRACE_FORMAT_PT; | |
808 | pt = &tinfo->variant.pt; | |
809 | ||
810 | pt->attr.size = sizeof (pt->attr); | |
811 | pt->attr.type = type; | |
812 | ||
813 | pt->attr.exclude_kernel = 1; | |
814 | pt->attr.exclude_hv = 1; | |
815 | pt->attr.exclude_idle = 1; | |
816 | ||
817 | errno = 0; | |
818 | pt->file = syscall (SYS_perf_event_open, &pt->attr, pid, -1, -1, 0); | |
819 | if (pt->file < 0) | |
820 | goto err; | |
821 | ||
822 | /* Allocate the configuration page. */ | |
823 | header = mmap (NULL, PAGE_SIZE, PROT_READ | PROT_WRITE, MAP_SHARED, | |
824 | pt->file, 0); | |
825 | if (header == MAP_FAILED) | |
826 | goto err_file; | |
827 | ||
828 | header->aux_offset = header->data_offset + header->data_size; | |
829 | ||
830 | /* Convert the requested size in bytes to pages (rounding up). */ | |
e7b01ce0 MM |
831 | pages = ((size_t) conf->size / PAGE_SIZE |
832 | + ((conf->size % PAGE_SIZE) == 0 ? 0 : 1)); | |
b20a6524 MM |
833 | /* We need at least one page. */ |
834 | if (pages == 0) | |
835 | pages = 1; | |
836 | ||
837 | /* The buffer size can be requested in powers of two pages. Adjust PAGES | |
838 | to the next power of two. */ | |
e7b01ce0 MM |
839 | for (pg = 0; pages != ((size_t) 1 << pg); ++pg) |
840 | if ((pages & ((size_t) 1 << pg)) != 0) | |
841 | pages += ((size_t) 1 << pg); | |
b20a6524 MM |
842 | |
843 | /* We try to allocate the requested size. | |
844 | If that fails, try to get as much as we can. */ | |
845 | for (; pages > 0; pages >>= 1) | |
846 | { | |
847 | size_t length; | |
e7b01ce0 | 848 | __u64 data_size; |
b20a6524 | 849 | |
e7b01ce0 MM |
850 | data_size = (__u64) pages * PAGE_SIZE; |
851 | ||
852 | /* Don't ask for more than we can represent in the configuration. */ | |
853 | if ((__u64) UINT_MAX < data_size) | |
854 | continue; | |
855 | ||
856 | size = (size_t) data_size; | |
b20a6524 MM |
857 | |
858 | /* Check for overflows. */ | |
e7b01ce0 | 859 | if ((__u64) size != data_size) |
b20a6524 MM |
860 | continue; |
861 | ||
e7b01ce0 MM |
862 | header->aux_size = data_size; |
863 | length = size; | |
b20a6524 MM |
864 | |
865 | pt->pt.mem = mmap (NULL, length, PROT_READ, MAP_SHARED, pt->file, | |
866 | header->aux_offset); | |
867 | if (pt->pt.mem != MAP_FAILED) | |
868 | break; | |
869 | } | |
870 | ||
871 | if (pages == 0) | |
872 | goto err_conf; | |
873 | ||
874 | pt->header = header; | |
875 | pt->pt.size = size; | |
876 | pt->pt.data_head = &header->aux_head; | |
877 | ||
e7b01ce0 | 878 | tinfo->conf.pt.size = (unsigned int) size; |
b20a6524 MM |
879 | return tinfo; |
880 | ||
881 | err_conf: | |
882 | munmap((void *) header, PAGE_SIZE); | |
883 | ||
884 | err_file: | |
885 | close (pt->file); | |
886 | ||
7c97f91e MM |
887 | err: |
888 | xfree (tinfo); | |
889 | return NULL; | |
890 | } | |
891 | ||
b20a6524 MM |
892 | #else /* !defined (PERF_ATTR_SIZE_VER5) */ |
893 | ||
894 | static struct btrace_target_info * | |
895 | linux_enable_pt (ptid_t ptid, const struct btrace_config_pt *conf) | |
896 | { | |
897 | errno = EOPNOTSUPP; | |
898 | return NULL; | |
899 | } | |
900 | ||
901 | #endif /* !defined (PERF_ATTR_SIZE_VER5) */ | |
902 | ||
7c97f91e MM |
903 | /* See linux-btrace.h. */ |
904 | ||
f4abbc16 MM |
905 | struct btrace_target_info * |
906 | linux_enable_btrace (ptid_t ptid, const struct btrace_config *conf) | |
907 | { | |
908 | struct btrace_target_info *tinfo; | |
909 | ||
910 | tinfo = NULL; | |
911 | switch (conf->format) | |
912 | { | |
913 | case BTRACE_FORMAT_NONE: | |
914 | break; | |
915 | ||
916 | case BTRACE_FORMAT_BTS: | |
d33501a5 | 917 | tinfo = linux_enable_bts (ptid, &conf->bts); |
f4abbc16 | 918 | break; |
b20a6524 MM |
919 | |
920 | case BTRACE_FORMAT_PT: | |
921 | tinfo = linux_enable_pt (ptid, &conf->pt); | |
922 | break; | |
f4abbc16 MM |
923 | } |
924 | ||
925 | return tinfo; | |
926 | } | |
927 | ||
928 | /* Disable BTS tracing. */ | |
929 | ||
930 | static enum btrace_error | |
931 | linux_disable_bts (struct btrace_tinfo_bts *tinfo) | |
7c97f91e | 932 | { |
aadf7753 | 933 | munmap((void *) tinfo->header, tinfo->bts.size + PAGE_SIZE); |
7c97f91e | 934 | close (tinfo->file); |
7c97f91e | 935 | |
969c39fb | 936 | return BTRACE_ERR_NONE; |
7c97f91e MM |
937 | } |
938 | ||
b20a6524 MM |
939 | /* Disable Intel(R) Processor Trace tracing. */ |
940 | ||
941 | static enum btrace_error | |
942 | linux_disable_pt (struct btrace_tinfo_pt *tinfo) | |
943 | { | |
944 | munmap((void *) tinfo->pt.mem, tinfo->pt.size); | |
945 | munmap((void *) tinfo->header, PAGE_SIZE); | |
946 | close (tinfo->file); | |
947 | ||
948 | return BTRACE_ERR_NONE; | |
949 | } | |
950 | ||
f4abbc16 MM |
951 | /* See linux-btrace.h. */ |
952 | ||
953 | enum btrace_error | |
954 | linux_disable_btrace (struct btrace_target_info *tinfo) | |
955 | { | |
956 | enum btrace_error errcode; | |
957 | ||
958 | errcode = BTRACE_ERR_NOT_SUPPORTED; | |
959 | switch (tinfo->conf.format) | |
960 | { | |
961 | case BTRACE_FORMAT_NONE: | |
962 | break; | |
963 | ||
964 | case BTRACE_FORMAT_BTS: | |
965 | errcode = linux_disable_bts (&tinfo->variant.bts); | |
966 | break; | |
b20a6524 MM |
967 | |
968 | case BTRACE_FORMAT_PT: | |
969 | errcode = linux_disable_pt (&tinfo->variant.pt); | |
970 | break; | |
f4abbc16 MM |
971 | } |
972 | ||
973 | if (errcode == BTRACE_ERR_NONE) | |
974 | xfree (tinfo); | |
975 | ||
976 | return errcode; | |
977 | } | |
978 | ||
734b0e4b MM |
979 | /* Read branch trace data in BTS format for the thread given by TINFO into |
980 | BTRACE using the TYPE reading method. */ | |
7c97f91e | 981 | |
734b0e4b MM |
982 | static enum btrace_error |
983 | linux_read_bts (struct btrace_data_bts *btrace, | |
984 | struct btrace_target_info *tinfo, | |
985 | enum btrace_read_type type) | |
7c97f91e | 986 | { |
aadf7753 | 987 | struct perf_event_buffer *pevent; |
7c97f91e | 988 | const uint8_t *begin, *end, *start; |
e7b01ce0 MM |
989 | size_t buffer_size, size; |
990 | __u64 data_head, data_tail; | |
aadf7753 MM |
991 | unsigned int retries = 5; |
992 | ||
f4abbc16 | 993 | pevent = &tinfo->variant.bts.bts; |
7c97f91e | 994 | |
969c39fb MM |
995 | /* For delta reads, we return at least the partial last block containing |
996 | the current PC. */ | |
aadf7753 | 997 | if (type == BTRACE_READ_NEW && !perf_event_new_data (pevent)) |
969c39fb | 998 | return BTRACE_ERR_NONE; |
7c97f91e | 999 | |
aadf7753 MM |
1000 | buffer_size = pevent->size; |
1001 | data_tail = pevent->last_head; | |
7c97f91e MM |
1002 | |
1003 | /* We may need to retry reading the trace. See below. */ | |
1004 | while (retries--) | |
1005 | { | |
aadf7753 | 1006 | data_head = *pevent->data_head; |
7c97f91e | 1007 | |
ed9edfb5 | 1008 | /* Delete any leftover trace from the previous iteration. */ |
734b0e4b | 1009 | VEC_free (btrace_block_s, btrace->blocks); |
ed9edfb5 | 1010 | |
969c39fb | 1011 | if (type == BTRACE_READ_DELTA) |
7c97f91e | 1012 | { |
e7b01ce0 MM |
1013 | __u64 data_size; |
1014 | ||
969c39fb MM |
1015 | /* Determine the number of bytes to read and check for buffer |
1016 | overflows. */ | |
1017 | ||
1018 | /* Check for data head overflows. We might be able to recover from | |
1019 | those but they are very unlikely and it's not really worth the | |
1020 | effort, I think. */ | |
1021 | if (data_head < data_tail) | |
1022 | return BTRACE_ERR_OVERFLOW; | |
1023 | ||
1024 | /* If the buffer is smaller than the trace delta, we overflowed. */ | |
e7b01ce0 MM |
1025 | data_size = data_head - data_tail; |
1026 | if (buffer_size < data_size) | |
969c39fb | 1027 | return BTRACE_ERR_OVERFLOW; |
e7b01ce0 MM |
1028 | |
1029 | /* DATA_SIZE <= BUFFER_SIZE and therefore fits into a size_t. */ | |
1030 | size = (size_t) data_size; | |
969c39fb MM |
1031 | } |
1032 | else | |
1033 | { | |
1034 | /* Read the entire buffer. */ | |
1035 | size = buffer_size; | |
7c97f91e | 1036 | |
969c39fb MM |
1037 | /* Adjust the size if the buffer has not overflowed, yet. */ |
1038 | if (data_head < size) | |
e7b01ce0 | 1039 | size = (size_t) data_head; |
7c97f91e MM |
1040 | } |
1041 | ||
969c39fb | 1042 | /* Data_head keeps growing; the buffer itself is circular. */ |
aadf7753 | 1043 | begin = pevent->mem; |
969c39fb MM |
1044 | start = begin + data_head % buffer_size; |
1045 | ||
1046 | if (data_head <= buffer_size) | |
1047 | end = start; | |
1048 | else | |
aadf7753 | 1049 | end = begin + pevent->size; |
969c39fb | 1050 | |
734b0e4b | 1051 | btrace->blocks = perf_event_read_bts (tinfo, begin, end, start, size); |
969c39fb | 1052 | |
7c97f91e MM |
1053 | /* The stopping thread notifies its ptracer before it is scheduled out. |
1054 | On multi-core systems, the debugger might therefore run while the | |
1055 | kernel might be writing the last branch trace records. | |
1056 | ||
1057 | Let's check whether the data head moved while we read the trace. */ | |
aadf7753 | 1058 | if (data_head == *pevent->data_head) |
7c97f91e MM |
1059 | break; |
1060 | } | |
1061 | ||
aadf7753 | 1062 | pevent->last_head = data_head; |
7c97f91e | 1063 | |
969c39fb MM |
1064 | /* Prune the incomplete last block (i.e. the first one of inferior execution) |
1065 | if we're not doing a delta read. There is no way of filling in its zeroed | |
1066 | BEGIN element. */ | |
734b0e4b MM |
1067 | if (!VEC_empty (btrace_block_s, btrace->blocks) |
1068 | && type != BTRACE_READ_DELTA) | |
1069 | VEC_pop (btrace_block_s, btrace->blocks); | |
969c39fb MM |
1070 | |
1071 | return BTRACE_ERR_NONE; | |
7c97f91e MM |
1072 | } |
1073 | ||
b20a6524 MM |
1074 | /* Fill in the Intel(R) Processor Trace configuration information. */ |
1075 | ||
1076 | static void | |
1077 | linux_fill_btrace_pt_config (struct btrace_data_pt_config *conf) | |
1078 | { | |
1079 | conf->cpu = btrace_this_cpu (); | |
1080 | } | |
1081 | ||
1082 | /* Read branch trace data in Intel(R) Processor Trace format for the thread | |
1083 | given by TINFO into BTRACE using the TYPE reading method. */ | |
1084 | ||
1085 | static enum btrace_error | |
1086 | linux_read_pt (struct btrace_data_pt *btrace, | |
1087 | struct btrace_target_info *tinfo, | |
1088 | enum btrace_read_type type) | |
1089 | { | |
1090 | struct perf_event_buffer *pt; | |
1091 | ||
1092 | pt = &tinfo->variant.pt.pt; | |
1093 | ||
1094 | linux_fill_btrace_pt_config (&btrace->config); | |
1095 | ||
1096 | switch (type) | |
1097 | { | |
1098 | case BTRACE_READ_DELTA: | |
1099 | /* We don't support delta reads. The data head (i.e. aux_head) wraps | |
1100 | around to stay inside the aux buffer. */ | |
1101 | return BTRACE_ERR_NOT_SUPPORTED; | |
1102 | ||
1103 | case BTRACE_READ_NEW: | |
1104 | if (!perf_event_new_data (pt)) | |
1105 | return BTRACE_ERR_NONE; | |
1106 | ||
1107 | /* Fall through. */ | |
1108 | case BTRACE_READ_ALL: | |
1109 | perf_event_read_all (pt, &btrace->data, &btrace->size); | |
1110 | return BTRACE_ERR_NONE; | |
1111 | } | |
1112 | ||
1113 | internal_error (__FILE__, __LINE__, _("Unkown btrace read type.")); | |
1114 | } | |
1115 | ||
734b0e4b MM |
1116 | /* See linux-btrace.h. */ |
1117 | ||
1118 | enum btrace_error | |
1119 | linux_read_btrace (struct btrace_data *btrace, | |
1120 | struct btrace_target_info *tinfo, | |
1121 | enum btrace_read_type type) | |
1122 | { | |
f4abbc16 MM |
1123 | switch (tinfo->conf.format) |
1124 | { | |
1125 | case BTRACE_FORMAT_NONE: | |
1126 | return BTRACE_ERR_NOT_SUPPORTED; | |
1127 | ||
1128 | case BTRACE_FORMAT_BTS: | |
1129 | /* We read btrace in BTS format. */ | |
1130 | btrace->format = BTRACE_FORMAT_BTS; | |
1131 | btrace->variant.bts.blocks = NULL; | |
1132 | ||
1133 | return linux_read_bts (&btrace->variant.bts, tinfo, type); | |
b20a6524 MM |
1134 | |
1135 | case BTRACE_FORMAT_PT: | |
1136 | /* We read btrace in Intel(R) Processor Trace format. */ | |
1137 | btrace->format = BTRACE_FORMAT_PT; | |
1138 | btrace->variant.pt.data = NULL; | |
1139 | btrace->variant.pt.size = 0; | |
1140 | ||
1141 | return linux_read_pt (&btrace->variant.pt, tinfo, type); | |
f4abbc16 MM |
1142 | } |
1143 | ||
1144 | internal_error (__FILE__, __LINE__, _("Unkown branch trace format.")); | |
1145 | } | |
1146 | ||
1147 | /* See linux-btrace.h. */ | |
734b0e4b | 1148 | |
f4abbc16 MM |
1149 | const struct btrace_config * |
1150 | linux_btrace_conf (const struct btrace_target_info *tinfo) | |
1151 | { | |
1152 | return &tinfo->conf; | |
734b0e4b MM |
1153 | } |
1154 | ||
7c97f91e MM |
1155 | #else /* !HAVE_LINUX_PERF_EVENT_H */ |
1156 | ||
1157 | /* See linux-btrace.h. */ | |
1158 | ||
1159 | int | |
043c3577 | 1160 | linux_supports_btrace (struct target_ops *ops, enum btrace_format format) |
7c97f91e MM |
1161 | { |
1162 | return 0; | |
1163 | } | |
1164 | ||
1165 | /* See linux-btrace.h. */ | |
1166 | ||
1167 | struct btrace_target_info * | |
f4abbc16 | 1168 | linux_enable_btrace (ptid_t ptid, const struct btrace_config *conf) |
7c97f91e MM |
1169 | { |
1170 | return NULL; | |
1171 | } | |
1172 | ||
1173 | /* See linux-btrace.h. */ | |
1174 | ||
969c39fb | 1175 | enum btrace_error |
7c97f91e MM |
1176 | linux_disable_btrace (struct btrace_target_info *tinfo) |
1177 | { | |
969c39fb | 1178 | return BTRACE_ERR_NOT_SUPPORTED; |
7c97f91e MM |
1179 | } |
1180 | ||
1181 | /* See linux-btrace.h. */ | |
1182 | ||
969c39fb | 1183 | enum btrace_error |
734b0e4b | 1184 | linux_read_btrace (struct btrace_data *btrace, |
969c39fb | 1185 | struct btrace_target_info *tinfo, |
7c97f91e MM |
1186 | enum btrace_read_type type) |
1187 | { | |
969c39fb | 1188 | return BTRACE_ERR_NOT_SUPPORTED; |
7c97f91e MM |
1189 | } |
1190 | ||
f4abbc16 MM |
1191 | /* See linux-btrace.h. */ |
1192 | ||
1193 | const struct btrace_config * | |
1194 | linux_btrace_conf (const struct btrace_target_info *tinfo) | |
1195 | { | |
1196 | return NULL; | |
1197 | } | |
1198 | ||
7c97f91e | 1199 | #endif /* !HAVE_LINUX_PERF_EVENT_H */ |