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7c97f91e MM |
1 | /* Linux-dependent part of branch trace support for GDB, and GDBserver. |
2 | ||
618f726f | 3 | Copyright (C) 2013-2016 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 | ||
b20a6524 MM |
106 | /* Copy the last SIZE bytes from PEV ending at DATA_HEAD and return a pointer |
107 | to the memory holding the copy. | |
108 | The caller is responsible for freeing the memory. */ | |
109 | ||
110 | static gdb_byte * | |
e7b01ce0 MM |
111 | perf_event_read (const struct perf_event_buffer *pev, __u64 data_head, |
112 | size_t size) | |
b20a6524 MM |
113 | { |
114 | const gdb_byte *begin, *end, *start, *stop; | |
115 | gdb_byte *buffer; | |
e7b01ce0 MM |
116 | size_t buffer_size; |
117 | __u64 data_tail; | |
b20a6524 MM |
118 | |
119 | if (size == 0) | |
120 | return NULL; | |
121 | ||
122 | gdb_assert (size <= data_head); | |
123 | data_tail = data_head - size; | |
124 | ||
125 | buffer_size = pev->size; | |
126 | begin = pev->mem; | |
127 | start = begin + data_tail % buffer_size; | |
128 | stop = begin + data_head % buffer_size; | |
129 | ||
224c3ddb | 130 | buffer = (gdb_byte *) xmalloc (size); |
b20a6524 MM |
131 | |
132 | if (start < stop) | |
133 | memcpy (buffer, start, stop - start); | |
134 | else | |
135 | { | |
136 | end = begin + buffer_size; | |
137 | ||
138 | memcpy (buffer, start, end - start); | |
139 | memcpy (buffer + (end - start), begin, stop - begin); | |
140 | } | |
141 | ||
142 | return buffer; | |
143 | } | |
144 | ||
145 | /* Copy the perf event buffer data from PEV. | |
146 | Store a pointer to the copy into DATA and its size in SIZE. */ | |
147 | ||
148 | static void | |
149 | perf_event_read_all (struct perf_event_buffer *pev, gdb_byte **data, | |
e7b01ce0 | 150 | size_t *psize) |
b20a6524 | 151 | { |
e7b01ce0 MM |
152 | size_t size; |
153 | __u64 data_head; | |
b20a6524 MM |
154 | |
155 | data_head = *pev->data_head; | |
156 | ||
157 | size = pev->size; | |
158 | if (data_head < size) | |
e7b01ce0 | 159 | size = (size_t) data_head; |
b20a6524 MM |
160 | |
161 | *data = perf_event_read (pev, data_head, size); | |
162 | *psize = size; | |
163 | ||
164 | pev->last_head = data_head; | |
165 | } | |
166 | ||
167 | /* Determine the event type. | |
168 | Returns zero on success and fills in TYPE; returns -1 otherwise. */ | |
169 | ||
170 | static int | |
171 | perf_event_pt_event_type (int *type) | |
172 | { | |
173 | FILE *file; | |
174 | int found; | |
175 | ||
176 | file = fopen ("/sys/bus/event_source/devices/intel_pt/type", "r"); | |
177 | if (file == NULL) | |
178 | return -1; | |
179 | ||
180 | found = fscanf (file, "%d", type); | |
181 | ||
182 | fclose (file); | |
183 | ||
184 | if (found == 1) | |
185 | return 0; | |
186 | return -1; | |
187 | } | |
188 | ||
0568462b MM |
189 | /* Try to determine the start address of the Linux kernel. */ |
190 | ||
191 | static uint64_t | |
192 | linux_determine_kernel_start (void) | |
d68e53f4 | 193 | { |
0568462b MM |
194 | static uint64_t kernel_start; |
195 | static int cached; | |
196 | FILE *file; | |
d68e53f4 | 197 | |
0568462b MM |
198 | if (cached != 0) |
199 | return kernel_start; | |
d68e53f4 | 200 | |
0568462b MM |
201 | cached = 1; |
202 | ||
203 | file = gdb_fopen_cloexec ("/proc/kallsyms", "r"); | |
204 | if (file == NULL) | |
205 | return kernel_start; | |
206 | ||
207 | while (!feof (file)) | |
208 | { | |
209 | char buffer[1024], symbol[8], *line; | |
210 | uint64_t addr; | |
211 | int match; | |
212 | ||
213 | line = fgets (buffer, sizeof (buffer), file); | |
214 | if (line == NULL) | |
215 | break; | |
d68e53f4 | 216 | |
0568462b MM |
217 | match = sscanf (line, "%" SCNx64 " %*[tT] %7s", &addr, symbol); |
218 | if (match != 2) | |
219 | continue; | |
d68e53f4 | 220 | |
0568462b MM |
221 | if (strcmp (symbol, "_text") == 0) |
222 | { | |
223 | kernel_start = addr; | |
224 | break; | |
225 | } | |
226 | } | |
227 | ||
228 | fclose (file); | |
229 | ||
230 | return kernel_start; | |
d68e53f4 MM |
231 | } |
232 | ||
7c97f91e MM |
233 | /* Check whether an address is in the kernel. */ |
234 | ||
235 | static inline int | |
0568462b | 236 | perf_event_is_kernel_addr (uint64_t addr) |
7c97f91e | 237 | { |
0568462b | 238 | uint64_t kernel_start; |
7c97f91e | 239 | |
0568462b MM |
240 | kernel_start = linux_determine_kernel_start (); |
241 | if (kernel_start != 0ull) | |
242 | return (addr >= kernel_start); | |
7c97f91e | 243 | |
0568462b MM |
244 | /* If we don't know the kernel's start address, let's check the most |
245 | significant bit. This will work at least for 64-bit kernels. */ | |
246 | return ((addr & (1ull << 63)) != 0); | |
7c97f91e MM |
247 | } |
248 | ||
249 | /* Check whether a perf event record should be skipped. */ | |
250 | ||
251 | static inline int | |
0568462b | 252 | perf_event_skip_bts_record (const struct perf_event_bts *bts) |
7c97f91e MM |
253 | { |
254 | /* The hardware may report branches from kernel into user space. Branches | |
255 | from user into kernel space will be suppressed. We filter the former to | |
256 | provide a consistent branch trace excluding kernel. */ | |
0568462b | 257 | return perf_event_is_kernel_addr (bts->from); |
7c97f91e MM |
258 | } |
259 | ||
260 | /* Perform a few consistency checks on a perf event sample record. This is | |
261 | meant to catch cases when we get out of sync with the perf event stream. */ | |
262 | ||
263 | static inline int | |
264 | perf_event_sample_ok (const struct perf_event_sample *sample) | |
265 | { | |
266 | if (sample->header.type != PERF_RECORD_SAMPLE) | |
267 | return 0; | |
268 | ||
269 | if (sample->header.size != sizeof (*sample)) | |
270 | return 0; | |
271 | ||
272 | return 1; | |
273 | } | |
274 | ||
275 | /* Branch trace is collected in a circular buffer [begin; end) as pairs of from | |
276 | and to addresses (plus a header). | |
277 | ||
278 | Start points into that buffer at the next sample position. | |
279 | We read the collected samples backwards from start. | |
280 | ||
281 | While reading the samples, we convert the information into a list of blocks. | |
282 | For two adjacent samples s1 and s2, we form a block b such that b.begin = | |
283 | s1.to and b.end = s2.from. | |
284 | ||
285 | In case the buffer overflows during sampling, one sample may have its lower | |
286 | part at the end and its upper part at the beginning of the buffer. */ | |
287 | ||
288 | static VEC (btrace_block_s) * | |
289 | perf_event_read_bts (struct btrace_target_info* tinfo, const uint8_t *begin, | |
e7b01ce0 | 290 | const uint8_t *end, const uint8_t *start, size_t size) |
7c97f91e MM |
291 | { |
292 | VEC (btrace_block_s) *btrace = NULL; | |
293 | struct perf_event_sample sample; | |
e7b01ce0 | 294 | size_t read = 0; |
7c97f91e MM |
295 | struct btrace_block block = { 0, 0 }; |
296 | struct regcache *regcache; | |
297 | ||
298 | gdb_assert (begin <= start); | |
299 | gdb_assert (start <= end); | |
300 | ||
301 | /* The first block ends at the current pc. */ | |
361c8ade | 302 | regcache = get_thread_regcache_for_ptid (tinfo->ptid); |
7c97f91e MM |
303 | block.end = regcache_read_pc (regcache); |
304 | ||
305 | /* The buffer may contain a partial record as its last entry (i.e. when the | |
306 | buffer size is not a multiple of the sample size). */ | |
307 | read = sizeof (sample) - 1; | |
308 | ||
309 | for (; read < size; read += sizeof (sample)) | |
310 | { | |
311 | const struct perf_event_sample *psample; | |
312 | ||
313 | /* Find the next perf_event sample in a backwards traversal. */ | |
314 | start -= sizeof (sample); | |
315 | ||
316 | /* If we're still inside the buffer, we're done. */ | |
317 | if (begin <= start) | |
318 | psample = (const struct perf_event_sample *) start; | |
319 | else | |
320 | { | |
321 | int missing; | |
322 | ||
323 | /* We're to the left of the ring buffer, we will wrap around and | |
324 | reappear at the very right of the ring buffer. */ | |
325 | ||
326 | missing = (begin - start); | |
327 | start = (end - missing); | |
328 | ||
329 | /* If the entire sample is missing, we're done. */ | |
330 | if (missing == sizeof (sample)) | |
331 | psample = (const struct perf_event_sample *) start; | |
332 | else | |
333 | { | |
334 | uint8_t *stack; | |
335 | ||
336 | /* The sample wrapped around. The lower part is at the end and | |
337 | the upper part is at the beginning of the buffer. */ | |
338 | stack = (uint8_t *) &sample; | |
339 | ||
340 | /* Copy the two parts so we have a contiguous sample. */ | |
341 | memcpy (stack, start, missing); | |
342 | memcpy (stack + missing, begin, sizeof (sample) - missing); | |
343 | ||
344 | psample = &sample; | |
345 | } | |
346 | } | |
347 | ||
348 | if (!perf_event_sample_ok (psample)) | |
349 | { | |
350 | warning (_("Branch trace may be incomplete.")); | |
351 | break; | |
352 | } | |
353 | ||
0568462b | 354 | if (perf_event_skip_bts_record (&psample->bts)) |
7c97f91e MM |
355 | continue; |
356 | ||
357 | /* We found a valid sample, so we can complete the current block. */ | |
358 | block.begin = psample->bts.to; | |
359 | ||
360 | VEC_safe_push (btrace_block_s, btrace, &block); | |
361 | ||
362 | /* Start the next block. */ | |
363 | block.end = psample->bts.from; | |
364 | } | |
365 | ||
969c39fb MM |
366 | /* Push the last block (i.e. the first one of inferior execution), as well. |
367 | We don't know where it ends, but we know where it starts. If we're | |
368 | reading delta trace, we can fill in the start address later on. | |
369 | Otherwise we will prune it. */ | |
370 | block.begin = 0; | |
371 | VEC_safe_push (btrace_block_s, btrace, &block); | |
372 | ||
7c97f91e MM |
373 | return btrace; |
374 | } | |
375 | ||
043c3577 | 376 | /* Check whether the kernel supports BTS. */ |
a950d57c MM |
377 | |
378 | static int | |
043c3577 | 379 | kernel_supports_bts (void) |
a950d57c MM |
380 | { |
381 | struct perf_event_attr attr; | |
382 | pid_t child, pid; | |
383 | int status, file; | |
384 | ||
385 | errno = 0; | |
386 | child = fork (); | |
387 | switch (child) | |
388 | { | |
389 | case -1: | |
76fb6829 | 390 | warning (_("test bts: cannot fork: %s."), safe_strerror (errno)); |
a950d57c MM |
391 | return 0; |
392 | ||
393 | case 0: | |
394 | status = ptrace (PTRACE_TRACEME, 0, NULL, NULL); | |
395 | if (status != 0) | |
396 | { | |
043c3577 | 397 | warning (_("test bts: cannot PTRACE_TRACEME: %s."), |
76fb6829 | 398 | safe_strerror (errno)); |
a950d57c MM |
399 | _exit (1); |
400 | } | |
401 | ||
402 | status = raise (SIGTRAP); | |
403 | if (status != 0) | |
404 | { | |
043c3577 | 405 | warning (_("test bts: cannot raise SIGTRAP: %s."), |
76fb6829 | 406 | safe_strerror (errno)); |
a950d57c MM |
407 | _exit (1); |
408 | } | |
409 | ||
410 | _exit (1); | |
411 | ||
412 | default: | |
413 | pid = waitpid (child, &status, 0); | |
414 | if (pid != child) | |
415 | { | |
043c3577 | 416 | warning (_("test bts: bad pid %ld, error: %s."), |
76fb6829 | 417 | (long) pid, safe_strerror (errno)); |
a950d57c MM |
418 | return 0; |
419 | } | |
420 | ||
421 | if (!WIFSTOPPED (status)) | |
422 | { | |
043c3577 | 423 | warning (_("test bts: expected stop. status: %d."), |
a950d57c MM |
424 | status); |
425 | return 0; | |
426 | } | |
427 | ||
428 | memset (&attr, 0, sizeof (attr)); | |
429 | ||
430 | attr.type = PERF_TYPE_HARDWARE; | |
431 | attr.config = PERF_COUNT_HW_BRANCH_INSTRUCTIONS; | |
432 | attr.sample_period = 1; | |
433 | attr.sample_type = PERF_SAMPLE_IP | PERF_SAMPLE_ADDR; | |
434 | attr.exclude_kernel = 1; | |
435 | attr.exclude_hv = 1; | |
436 | attr.exclude_idle = 1; | |
437 | ||
438 | file = syscall (SYS_perf_event_open, &attr, child, -1, -1, 0); | |
439 | if (file >= 0) | |
440 | close (file); | |
441 | ||
442 | kill (child, SIGKILL); | |
443 | ptrace (PTRACE_KILL, child, NULL, NULL); | |
444 | ||
445 | pid = waitpid (child, &status, 0); | |
446 | if (pid != child) | |
447 | { | |
043c3577 | 448 | warning (_("test bts: bad pid %ld, error: %s."), |
76fb6829 | 449 | (long) pid, safe_strerror (errno)); |
a950d57c | 450 | if (!WIFSIGNALED (status)) |
043c3577 | 451 | warning (_("test bts: expected killed. status: %d."), |
a950d57c MM |
452 | status); |
453 | } | |
454 | ||
455 | return (file >= 0); | |
456 | } | |
457 | } | |
458 | ||
bc504a31 | 459 | /* Check whether the kernel supports Intel Processor Trace. */ |
b20a6524 MM |
460 | |
461 | static int | |
462 | kernel_supports_pt (void) | |
463 | { | |
464 | struct perf_event_attr attr; | |
465 | pid_t child, pid; | |
466 | int status, file, type; | |
467 | ||
468 | errno = 0; | |
469 | child = fork (); | |
470 | switch (child) | |
471 | { | |
472 | case -1: | |
76fb6829 | 473 | warning (_("test pt: cannot fork: %s."), safe_strerror (errno)); |
b20a6524 MM |
474 | return 0; |
475 | ||
476 | case 0: | |
477 | status = ptrace (PTRACE_TRACEME, 0, NULL, NULL); | |
478 | if (status != 0) | |
479 | { | |
480 | warning (_("test pt: cannot PTRACE_TRACEME: %s."), | |
76fb6829 | 481 | safe_strerror (errno)); |
b20a6524 MM |
482 | _exit (1); |
483 | } | |
484 | ||
485 | status = raise (SIGTRAP); | |
486 | if (status != 0) | |
487 | { | |
488 | warning (_("test pt: cannot raise SIGTRAP: %s."), | |
76fb6829 | 489 | safe_strerror (errno)); |
b20a6524 MM |
490 | _exit (1); |
491 | } | |
492 | ||
493 | _exit (1); | |
494 | ||
495 | default: | |
496 | pid = waitpid (child, &status, 0); | |
497 | if (pid != child) | |
498 | { | |
499 | warning (_("test pt: bad pid %ld, error: %s."), | |
76fb6829 | 500 | (long) pid, safe_strerror (errno)); |
b20a6524 MM |
501 | return 0; |
502 | } | |
503 | ||
504 | if (!WIFSTOPPED (status)) | |
505 | { | |
506 | warning (_("test pt: expected stop. status: %d."), | |
507 | status); | |
508 | return 0; | |
509 | } | |
510 | ||
511 | status = perf_event_pt_event_type (&type); | |
512 | if (status != 0) | |
513 | file = -1; | |
514 | else | |
515 | { | |
516 | memset (&attr, 0, sizeof (attr)); | |
517 | ||
518 | attr.size = sizeof (attr); | |
519 | attr.type = type; | |
520 | attr.exclude_kernel = 1; | |
521 | attr.exclude_hv = 1; | |
522 | attr.exclude_idle = 1; | |
523 | ||
524 | file = syscall (SYS_perf_event_open, &attr, child, -1, -1, 0); | |
525 | if (file >= 0) | |
526 | close (file); | |
527 | } | |
528 | ||
529 | kill (child, SIGKILL); | |
530 | ptrace (PTRACE_KILL, child, NULL, NULL); | |
531 | ||
532 | pid = waitpid (child, &status, 0); | |
533 | if (pid != child) | |
534 | { | |
535 | warning (_("test pt: bad pid %ld, error: %s."), | |
76fb6829 | 536 | (long) pid, safe_strerror (errno)); |
b20a6524 MM |
537 | if (!WIFSIGNALED (status)) |
538 | warning (_("test pt: expected killed. status: %d."), | |
539 | status); | |
540 | } | |
541 | ||
542 | return (file >= 0); | |
543 | } | |
544 | } | |
545 | ||
043c3577 | 546 | /* Check whether an Intel cpu supports BTS. */ |
a950d57c MM |
547 | |
548 | static int | |
afb778a2 | 549 | intel_supports_bts (const struct btrace_cpu *cpu) |
a950d57c | 550 | { |
afb778a2 | 551 | switch (cpu->family) |
5f8e0b8f MF |
552 | { |
553 | case 0x6: | |
afb778a2 | 554 | switch (cpu->model) |
5f8e0b8f MF |
555 | { |
556 | case 0x1a: /* Nehalem */ | |
557 | case 0x1f: | |
558 | case 0x1e: | |
559 | case 0x2e: | |
560 | case 0x25: /* Westmere */ | |
561 | case 0x2c: | |
562 | case 0x2f: | |
563 | case 0x2a: /* Sandy Bridge */ | |
564 | case 0x2d: | |
565 | case 0x3a: /* Ivy Bridge */ | |
566 | ||
567 | /* AAJ122: LBR, BTM, or BTS records may have incorrect branch | |
568 | "from" information afer an EIST transition, T-states, C1E, or | |
569 | Adaptive Thermal Throttling. */ | |
570 | return 0; | |
571 | } | |
572 | } | |
a950d57c MM |
573 | |
574 | return 1; | |
a950d57c MM |
575 | } |
576 | ||
043c3577 | 577 | /* Check whether the cpu supports BTS. */ |
a950d57c MM |
578 | |
579 | static int | |
043c3577 | 580 | cpu_supports_bts (void) |
a950d57c | 581 | { |
afb778a2 | 582 | struct btrace_cpu cpu; |
a950d57c | 583 | |
afb778a2 MM |
584 | cpu = btrace_this_cpu (); |
585 | switch (cpu.vendor) | |
586 | { | |
587 | default: | |
588 | /* Don't know about others. Let's assume they do. */ | |
589 | return 1; | |
a950d57c | 590 | |
afb778a2 MM |
591 | case CV_INTEL: |
592 | return intel_supports_bts (&cpu); | |
593 | } | |
a950d57c MM |
594 | } |
595 | ||
043c3577 | 596 | /* Check whether the linux target supports BTS. */ |
7c97f91e | 597 | |
043c3577 MM |
598 | static int |
599 | linux_supports_bts (void) | |
7c97f91e | 600 | { |
a950d57c MM |
601 | static int cached; |
602 | ||
603 | if (cached == 0) | |
604 | { | |
043c3577 | 605 | if (!kernel_supports_bts ()) |
a950d57c | 606 | cached = -1; |
043c3577 | 607 | else if (!cpu_supports_bts ()) |
a950d57c MM |
608 | cached = -1; |
609 | else | |
610 | cached = 1; | |
611 | } | |
612 | ||
613 | return cached > 0; | |
7c97f91e MM |
614 | } |
615 | ||
bc504a31 | 616 | /* Check whether the linux target supports Intel Processor Trace. */ |
b20a6524 MM |
617 | |
618 | static int | |
619 | linux_supports_pt (void) | |
620 | { | |
621 | static int cached; | |
622 | ||
623 | if (cached == 0) | |
624 | { | |
625 | if (!kernel_supports_pt ()) | |
626 | cached = -1; | |
627 | else | |
628 | cached = 1; | |
629 | } | |
630 | ||
631 | return cached > 0; | |
632 | } | |
633 | ||
7c97f91e MM |
634 | /* See linux-btrace.h. */ |
635 | ||
043c3577 MM |
636 | int |
637 | linux_supports_btrace (struct target_ops *ops, enum btrace_format format) | |
638 | { | |
639 | switch (format) | |
640 | { | |
641 | case BTRACE_FORMAT_NONE: | |
642 | return 0; | |
643 | ||
644 | case BTRACE_FORMAT_BTS: | |
645 | return linux_supports_bts (); | |
b20a6524 MM |
646 | |
647 | case BTRACE_FORMAT_PT: | |
648 | return linux_supports_pt (); | |
043c3577 MM |
649 | } |
650 | ||
651 | internal_error (__FILE__, __LINE__, _("Unknown branch trace format")); | |
652 | } | |
653 | ||
f4abbc16 | 654 | /* Enable branch tracing in BTS format. */ |
043c3577 | 655 | |
f4abbc16 | 656 | static struct btrace_target_info * |
d33501a5 | 657 | linux_enable_bts (ptid_t ptid, const struct btrace_config_bts *conf) |
7c97f91e | 658 | { |
aadf7753 | 659 | struct perf_event_mmap_page *header; |
7c97f91e | 660 | struct btrace_target_info *tinfo; |
f4abbc16 | 661 | struct btrace_tinfo_bts *bts; |
e7b01ce0 MM |
662 | size_t size, pages; |
663 | __u64 data_offset; | |
d0fa7535 | 664 | int pid, pg; |
7c97f91e | 665 | |
8d749320 | 666 | tinfo = XCNEW (struct btrace_target_info); |
7c97f91e MM |
667 | tinfo->ptid = ptid; |
668 | ||
f4abbc16 MM |
669 | tinfo->conf.format = BTRACE_FORMAT_BTS; |
670 | bts = &tinfo->variant.bts; | |
7c97f91e | 671 | |
f4abbc16 MM |
672 | bts->attr.size = sizeof (bts->attr); |
673 | bts->attr.type = PERF_TYPE_HARDWARE; | |
674 | bts->attr.config = PERF_COUNT_HW_BRANCH_INSTRUCTIONS; | |
675 | bts->attr.sample_period = 1; | |
7c97f91e | 676 | |
f4abbc16 MM |
677 | /* We sample from and to address. */ |
678 | bts->attr.sample_type = PERF_SAMPLE_IP | PERF_SAMPLE_ADDR; | |
7c97f91e | 679 | |
f4abbc16 MM |
680 | bts->attr.exclude_kernel = 1; |
681 | bts->attr.exclude_hv = 1; | |
682 | bts->attr.exclude_idle = 1; | |
7c97f91e MM |
683 | |
684 | pid = ptid_get_lwp (ptid); | |
685 | if (pid == 0) | |
686 | pid = ptid_get_pid (ptid); | |
687 | ||
688 | errno = 0; | |
f4abbc16 MM |
689 | bts->file = syscall (SYS_perf_event_open, &bts->attr, pid, -1, -1, 0); |
690 | if (bts->file < 0) | |
b20a6524 | 691 | goto err_out; |
7c97f91e | 692 | |
d33501a5 | 693 | /* Convert the requested size in bytes to pages (rounding up). */ |
e7b01ce0 MM |
694 | pages = ((size_t) conf->size / PAGE_SIZE |
695 | + ((conf->size % PAGE_SIZE) == 0 ? 0 : 1)); | |
d33501a5 MM |
696 | /* We need at least one page. */ |
697 | if (pages == 0) | |
698 | pages = 1; | |
699 | ||
700 | /* The buffer size can be requested in powers of two pages. Adjust PAGES | |
701 | to the next power of two. */ | |
e7b01ce0 MM |
702 | for (pg = 0; pages != ((size_t) 1 << pg); ++pg) |
703 | if ((pages & ((size_t) 1 << pg)) != 0) | |
704 | pages += ((size_t) 1 << pg); | |
d33501a5 MM |
705 | |
706 | /* We try to allocate the requested size. | |
707 | If that fails, try to get as much as we can. */ | |
708 | for (; pages > 0; pages >>= 1) | |
d0fa7535 | 709 | { |
d33501a5 | 710 | size_t length; |
e7b01ce0 | 711 | __u64 data_size; |
d33501a5 | 712 | |
e7b01ce0 MM |
713 | data_size = (__u64) pages * PAGE_SIZE; |
714 | ||
715 | /* Don't ask for more than we can represent in the configuration. */ | |
716 | if ((__u64) UINT_MAX < data_size) | |
717 | continue; | |
718 | ||
719 | size = (size_t) data_size; | |
d33501a5 MM |
720 | length = size + PAGE_SIZE; |
721 | ||
722 | /* Check for overflows. */ | |
e7b01ce0 | 723 | if ((__u64) length != data_size + PAGE_SIZE) |
d33501a5 MM |
724 | continue; |
725 | ||
d0fa7535 | 726 | /* The number of pages we request needs to be a power of two. */ |
224c3ddb SM |
727 | header = ((struct perf_event_mmap_page *) |
728 | mmap (NULL, length, PROT_READ, MAP_SHARED, bts->file, 0)); | |
aadf7753 MM |
729 | if (header != MAP_FAILED) |
730 | break; | |
d0fa7535 | 731 | } |
7c97f91e | 732 | |
010a18a1 | 733 | if (pages == 0) |
aadf7753 MM |
734 | goto err_file; |
735 | ||
010a18a1 | 736 | data_offset = PAGE_SIZE; |
010a18a1 MM |
737 | |
738 | #if defined (PERF_ATTR_SIZE_VER5) | |
739 | if (offsetof (struct perf_event_mmap_page, data_size) <= header->size) | |
740 | { | |
e7b01ce0 MM |
741 | __u64 data_size; |
742 | ||
010a18a1 MM |
743 | data_offset = header->data_offset; |
744 | data_size = header->data_size; | |
e7b01ce0 MM |
745 | |
746 | size = (unsigned int) data_size; | |
747 | ||
748 | /* Check for overflows. */ | |
749 | if ((__u64) size != data_size) | |
750 | { | |
751 | munmap ((void *) header, size + PAGE_SIZE); | |
752 | goto err_file; | |
753 | } | |
010a18a1 MM |
754 | } |
755 | #endif /* defined (PERF_ATTR_SIZE_VER5) */ | |
756 | ||
f4abbc16 | 757 | bts->header = header; |
010a18a1 | 758 | bts->bts.mem = ((const uint8_t *) header) + data_offset; |
e7b01ce0 | 759 | bts->bts.size = size; |
f4abbc16 | 760 | bts->bts.data_head = &header->data_head; |
e7b01ce0 | 761 | bts->bts.last_head = 0ull; |
aadf7753 | 762 | |
e7b01ce0 | 763 | tinfo->conf.bts.size = (unsigned int) size; |
aadf7753 MM |
764 | return tinfo; |
765 | ||
766 | err_file: | |
d0fa7535 | 767 | /* We were not able to allocate any buffer. */ |
f4abbc16 | 768 | close (bts->file); |
7c97f91e | 769 | |
b20a6524 MM |
770 | err_out: |
771 | xfree (tinfo); | |
772 | return NULL; | |
773 | } | |
774 | ||
775 | #if defined (PERF_ATTR_SIZE_VER5) | |
776 | ||
bc504a31 | 777 | /* Enable branch tracing in Intel Processor Trace format. */ |
b20a6524 MM |
778 | |
779 | static struct btrace_target_info * | |
780 | linux_enable_pt (ptid_t ptid, const struct btrace_config_pt *conf) | |
781 | { | |
782 | struct perf_event_mmap_page *header; | |
783 | struct btrace_target_info *tinfo; | |
784 | struct btrace_tinfo_pt *pt; | |
e7b01ce0 | 785 | size_t pages, size; |
b20a6524 MM |
786 | int pid, pg, errcode, type; |
787 | ||
788 | if (conf->size == 0) | |
789 | return NULL; | |
790 | ||
791 | errcode = perf_event_pt_event_type (&type); | |
792 | if (errcode != 0) | |
793 | return NULL; | |
794 | ||
795 | pid = ptid_get_lwp (ptid); | |
796 | if (pid == 0) | |
797 | pid = ptid_get_pid (ptid); | |
798 | ||
8d749320 | 799 | tinfo = XCNEW (struct btrace_target_info); |
b20a6524 | 800 | tinfo->ptid = ptid; |
b20a6524 MM |
801 | |
802 | tinfo->conf.format = BTRACE_FORMAT_PT; | |
803 | pt = &tinfo->variant.pt; | |
804 | ||
805 | pt->attr.size = sizeof (pt->attr); | |
806 | pt->attr.type = type; | |
807 | ||
808 | pt->attr.exclude_kernel = 1; | |
809 | pt->attr.exclude_hv = 1; | |
810 | pt->attr.exclude_idle = 1; | |
811 | ||
812 | errno = 0; | |
813 | pt->file = syscall (SYS_perf_event_open, &pt->attr, pid, -1, -1, 0); | |
814 | if (pt->file < 0) | |
815 | goto err; | |
816 | ||
817 | /* Allocate the configuration page. */ | |
a55515ee SM |
818 | header = ((struct perf_event_mmap_page *) |
819 | mmap (NULL, PAGE_SIZE, PROT_READ | PROT_WRITE, MAP_SHARED, | |
820 | pt->file, 0)); | |
b20a6524 MM |
821 | if (header == MAP_FAILED) |
822 | goto err_file; | |
823 | ||
824 | header->aux_offset = header->data_offset + header->data_size; | |
825 | ||
826 | /* Convert the requested size in bytes to pages (rounding up). */ | |
e7b01ce0 MM |
827 | pages = ((size_t) conf->size / PAGE_SIZE |
828 | + ((conf->size % PAGE_SIZE) == 0 ? 0 : 1)); | |
b20a6524 MM |
829 | /* We need at least one page. */ |
830 | if (pages == 0) | |
831 | pages = 1; | |
832 | ||
833 | /* The buffer size can be requested in powers of two pages. Adjust PAGES | |
834 | to the next power of two. */ | |
e7b01ce0 MM |
835 | for (pg = 0; pages != ((size_t) 1 << pg); ++pg) |
836 | if ((pages & ((size_t) 1 << pg)) != 0) | |
837 | pages += ((size_t) 1 << pg); | |
b20a6524 MM |
838 | |
839 | /* We try to allocate the requested size. | |
840 | If that fails, try to get as much as we can. */ | |
841 | for (; pages > 0; pages >>= 1) | |
842 | { | |
843 | size_t length; | |
e7b01ce0 | 844 | __u64 data_size; |
b20a6524 | 845 | |
e7b01ce0 MM |
846 | data_size = (__u64) pages * PAGE_SIZE; |
847 | ||
848 | /* Don't ask for more than we can represent in the configuration. */ | |
849 | if ((__u64) UINT_MAX < data_size) | |
850 | continue; | |
851 | ||
852 | size = (size_t) data_size; | |
b20a6524 MM |
853 | |
854 | /* Check for overflows. */ | |
e7b01ce0 | 855 | if ((__u64) size != data_size) |
b20a6524 MM |
856 | continue; |
857 | ||
e7b01ce0 MM |
858 | header->aux_size = data_size; |
859 | length = size; | |
b20a6524 | 860 | |
a55515ee SM |
861 | pt->pt.mem = ((const uint8_t *) |
862 | mmap (NULL, length, PROT_READ, MAP_SHARED, pt->file, | |
863 | header->aux_offset)); | |
b20a6524 MM |
864 | if (pt->pt.mem != MAP_FAILED) |
865 | break; | |
866 | } | |
867 | ||
868 | if (pages == 0) | |
869 | goto err_conf; | |
870 | ||
871 | pt->header = header; | |
872 | pt->pt.size = size; | |
873 | pt->pt.data_head = &header->aux_head; | |
874 | ||
e7b01ce0 | 875 | tinfo->conf.pt.size = (unsigned int) size; |
b20a6524 MM |
876 | return tinfo; |
877 | ||
878 | err_conf: | |
879 | munmap((void *) header, PAGE_SIZE); | |
880 | ||
881 | err_file: | |
882 | close (pt->file); | |
883 | ||
7c97f91e MM |
884 | err: |
885 | xfree (tinfo); | |
886 | return NULL; | |
887 | } | |
888 | ||
b20a6524 MM |
889 | #else /* !defined (PERF_ATTR_SIZE_VER5) */ |
890 | ||
891 | static struct btrace_target_info * | |
892 | linux_enable_pt (ptid_t ptid, const struct btrace_config_pt *conf) | |
893 | { | |
894 | errno = EOPNOTSUPP; | |
895 | return NULL; | |
896 | } | |
897 | ||
898 | #endif /* !defined (PERF_ATTR_SIZE_VER5) */ | |
899 | ||
7c97f91e MM |
900 | /* See linux-btrace.h. */ |
901 | ||
f4abbc16 MM |
902 | struct btrace_target_info * |
903 | linux_enable_btrace (ptid_t ptid, const struct btrace_config *conf) | |
904 | { | |
905 | struct btrace_target_info *tinfo; | |
906 | ||
907 | tinfo = NULL; | |
908 | switch (conf->format) | |
909 | { | |
910 | case BTRACE_FORMAT_NONE: | |
911 | break; | |
912 | ||
913 | case BTRACE_FORMAT_BTS: | |
d33501a5 | 914 | tinfo = linux_enable_bts (ptid, &conf->bts); |
f4abbc16 | 915 | break; |
b20a6524 MM |
916 | |
917 | case BTRACE_FORMAT_PT: | |
918 | tinfo = linux_enable_pt (ptid, &conf->pt); | |
919 | break; | |
f4abbc16 MM |
920 | } |
921 | ||
922 | return tinfo; | |
923 | } | |
924 | ||
925 | /* Disable BTS tracing. */ | |
926 | ||
927 | static enum btrace_error | |
928 | linux_disable_bts (struct btrace_tinfo_bts *tinfo) | |
7c97f91e | 929 | { |
aadf7753 | 930 | munmap((void *) tinfo->header, tinfo->bts.size + PAGE_SIZE); |
7c97f91e | 931 | close (tinfo->file); |
7c97f91e | 932 | |
969c39fb | 933 | return BTRACE_ERR_NONE; |
7c97f91e MM |
934 | } |
935 | ||
bc504a31 | 936 | /* Disable Intel Processor Trace tracing. */ |
b20a6524 MM |
937 | |
938 | static enum btrace_error | |
939 | linux_disable_pt (struct btrace_tinfo_pt *tinfo) | |
940 | { | |
941 | munmap((void *) tinfo->pt.mem, tinfo->pt.size); | |
942 | munmap((void *) tinfo->header, PAGE_SIZE); | |
943 | close (tinfo->file); | |
944 | ||
945 | return BTRACE_ERR_NONE; | |
946 | } | |
947 | ||
f4abbc16 MM |
948 | /* See linux-btrace.h. */ |
949 | ||
950 | enum btrace_error | |
951 | linux_disable_btrace (struct btrace_target_info *tinfo) | |
952 | { | |
953 | enum btrace_error errcode; | |
954 | ||
955 | errcode = BTRACE_ERR_NOT_SUPPORTED; | |
956 | switch (tinfo->conf.format) | |
957 | { | |
958 | case BTRACE_FORMAT_NONE: | |
959 | break; | |
960 | ||
961 | case BTRACE_FORMAT_BTS: | |
962 | errcode = linux_disable_bts (&tinfo->variant.bts); | |
963 | break; | |
b20a6524 MM |
964 | |
965 | case BTRACE_FORMAT_PT: | |
966 | errcode = linux_disable_pt (&tinfo->variant.pt); | |
967 | break; | |
f4abbc16 MM |
968 | } |
969 | ||
970 | if (errcode == BTRACE_ERR_NONE) | |
971 | xfree (tinfo); | |
972 | ||
973 | return errcode; | |
974 | } | |
975 | ||
734b0e4b MM |
976 | /* Read branch trace data in BTS format for the thread given by TINFO into |
977 | BTRACE using the TYPE reading method. */ | |
7c97f91e | 978 | |
734b0e4b MM |
979 | static enum btrace_error |
980 | linux_read_bts (struct btrace_data_bts *btrace, | |
981 | struct btrace_target_info *tinfo, | |
982 | enum btrace_read_type type) | |
7c97f91e | 983 | { |
aadf7753 | 984 | struct perf_event_buffer *pevent; |
7c97f91e | 985 | const uint8_t *begin, *end, *start; |
e7b01ce0 MM |
986 | size_t buffer_size, size; |
987 | __u64 data_head, data_tail; | |
aadf7753 MM |
988 | unsigned int retries = 5; |
989 | ||
f4abbc16 | 990 | pevent = &tinfo->variant.bts.bts; |
7c97f91e | 991 | |
969c39fb MM |
992 | /* For delta reads, we return at least the partial last block containing |
993 | the current PC. */ | |
aadf7753 | 994 | if (type == BTRACE_READ_NEW && !perf_event_new_data (pevent)) |
969c39fb | 995 | return BTRACE_ERR_NONE; |
7c97f91e | 996 | |
aadf7753 MM |
997 | buffer_size = pevent->size; |
998 | data_tail = pevent->last_head; | |
7c97f91e MM |
999 | |
1000 | /* We may need to retry reading the trace. See below. */ | |
1001 | while (retries--) | |
1002 | { | |
aadf7753 | 1003 | data_head = *pevent->data_head; |
7c97f91e | 1004 | |
ed9edfb5 | 1005 | /* Delete any leftover trace from the previous iteration. */ |
734b0e4b | 1006 | VEC_free (btrace_block_s, btrace->blocks); |
ed9edfb5 | 1007 | |
969c39fb | 1008 | if (type == BTRACE_READ_DELTA) |
7c97f91e | 1009 | { |
e7b01ce0 MM |
1010 | __u64 data_size; |
1011 | ||
969c39fb MM |
1012 | /* Determine the number of bytes to read and check for buffer |
1013 | overflows. */ | |
1014 | ||
1015 | /* Check for data head overflows. We might be able to recover from | |
1016 | those but they are very unlikely and it's not really worth the | |
1017 | effort, I think. */ | |
1018 | if (data_head < data_tail) | |
1019 | return BTRACE_ERR_OVERFLOW; | |
1020 | ||
1021 | /* If the buffer is smaller than the trace delta, we overflowed. */ | |
e7b01ce0 MM |
1022 | data_size = data_head - data_tail; |
1023 | if (buffer_size < data_size) | |
969c39fb | 1024 | return BTRACE_ERR_OVERFLOW; |
e7b01ce0 MM |
1025 | |
1026 | /* DATA_SIZE <= BUFFER_SIZE and therefore fits into a size_t. */ | |
1027 | size = (size_t) data_size; | |
969c39fb MM |
1028 | } |
1029 | else | |
1030 | { | |
1031 | /* Read the entire buffer. */ | |
1032 | size = buffer_size; | |
7c97f91e | 1033 | |
969c39fb MM |
1034 | /* Adjust the size if the buffer has not overflowed, yet. */ |
1035 | if (data_head < size) | |
e7b01ce0 | 1036 | size = (size_t) data_head; |
7c97f91e MM |
1037 | } |
1038 | ||
969c39fb | 1039 | /* Data_head keeps growing; the buffer itself is circular. */ |
aadf7753 | 1040 | begin = pevent->mem; |
969c39fb MM |
1041 | start = begin + data_head % buffer_size; |
1042 | ||
1043 | if (data_head <= buffer_size) | |
1044 | end = start; | |
1045 | else | |
aadf7753 | 1046 | end = begin + pevent->size; |
969c39fb | 1047 | |
734b0e4b | 1048 | btrace->blocks = perf_event_read_bts (tinfo, begin, end, start, size); |
969c39fb | 1049 | |
7c97f91e MM |
1050 | /* The stopping thread notifies its ptracer before it is scheduled out. |
1051 | On multi-core systems, the debugger might therefore run while the | |
1052 | kernel might be writing the last branch trace records. | |
1053 | ||
1054 | Let's check whether the data head moved while we read the trace. */ | |
aadf7753 | 1055 | if (data_head == *pevent->data_head) |
7c97f91e MM |
1056 | break; |
1057 | } | |
1058 | ||
aadf7753 | 1059 | pevent->last_head = data_head; |
7c97f91e | 1060 | |
969c39fb MM |
1061 | /* Prune the incomplete last block (i.e. the first one of inferior execution) |
1062 | if we're not doing a delta read. There is no way of filling in its zeroed | |
1063 | BEGIN element. */ | |
734b0e4b MM |
1064 | if (!VEC_empty (btrace_block_s, btrace->blocks) |
1065 | && type != BTRACE_READ_DELTA) | |
1066 | VEC_pop (btrace_block_s, btrace->blocks); | |
969c39fb MM |
1067 | |
1068 | return BTRACE_ERR_NONE; | |
7c97f91e MM |
1069 | } |
1070 | ||
bc504a31 | 1071 | /* Fill in the Intel Processor Trace configuration information. */ |
b20a6524 MM |
1072 | |
1073 | static void | |
1074 | linux_fill_btrace_pt_config (struct btrace_data_pt_config *conf) | |
1075 | { | |
1076 | conf->cpu = btrace_this_cpu (); | |
1077 | } | |
1078 | ||
bc504a31 | 1079 | /* Read branch trace data in Intel Processor Trace format for the thread |
b20a6524 MM |
1080 | given by TINFO into BTRACE using the TYPE reading method. */ |
1081 | ||
1082 | static enum btrace_error | |
1083 | linux_read_pt (struct btrace_data_pt *btrace, | |
1084 | struct btrace_target_info *tinfo, | |
1085 | enum btrace_read_type type) | |
1086 | { | |
1087 | struct perf_event_buffer *pt; | |
1088 | ||
1089 | pt = &tinfo->variant.pt.pt; | |
1090 | ||
1091 | linux_fill_btrace_pt_config (&btrace->config); | |
1092 | ||
1093 | switch (type) | |
1094 | { | |
1095 | case BTRACE_READ_DELTA: | |
1096 | /* We don't support delta reads. The data head (i.e. aux_head) wraps | |
1097 | around to stay inside the aux buffer. */ | |
1098 | return BTRACE_ERR_NOT_SUPPORTED; | |
1099 | ||
1100 | case BTRACE_READ_NEW: | |
1101 | if (!perf_event_new_data (pt)) | |
1102 | return BTRACE_ERR_NONE; | |
1103 | ||
1104 | /* Fall through. */ | |
1105 | case BTRACE_READ_ALL: | |
1106 | perf_event_read_all (pt, &btrace->data, &btrace->size); | |
1107 | return BTRACE_ERR_NONE; | |
1108 | } | |
1109 | ||
1110 | internal_error (__FILE__, __LINE__, _("Unkown btrace read type.")); | |
1111 | } | |
1112 | ||
734b0e4b MM |
1113 | /* See linux-btrace.h. */ |
1114 | ||
1115 | enum btrace_error | |
1116 | linux_read_btrace (struct btrace_data *btrace, | |
1117 | struct btrace_target_info *tinfo, | |
1118 | enum btrace_read_type type) | |
1119 | { | |
f4abbc16 MM |
1120 | switch (tinfo->conf.format) |
1121 | { | |
1122 | case BTRACE_FORMAT_NONE: | |
1123 | return BTRACE_ERR_NOT_SUPPORTED; | |
1124 | ||
1125 | case BTRACE_FORMAT_BTS: | |
1126 | /* We read btrace in BTS format. */ | |
1127 | btrace->format = BTRACE_FORMAT_BTS; | |
1128 | btrace->variant.bts.blocks = NULL; | |
1129 | ||
1130 | return linux_read_bts (&btrace->variant.bts, tinfo, type); | |
b20a6524 MM |
1131 | |
1132 | case BTRACE_FORMAT_PT: | |
bc504a31 | 1133 | /* We read btrace in Intel Processor Trace format. */ |
b20a6524 MM |
1134 | btrace->format = BTRACE_FORMAT_PT; |
1135 | btrace->variant.pt.data = NULL; | |
1136 | btrace->variant.pt.size = 0; | |
1137 | ||
1138 | return linux_read_pt (&btrace->variant.pt, tinfo, type); | |
f4abbc16 MM |
1139 | } |
1140 | ||
1141 | internal_error (__FILE__, __LINE__, _("Unkown branch trace format.")); | |
1142 | } | |
1143 | ||
1144 | /* See linux-btrace.h. */ | |
734b0e4b | 1145 | |
f4abbc16 MM |
1146 | const struct btrace_config * |
1147 | linux_btrace_conf (const struct btrace_target_info *tinfo) | |
1148 | { | |
1149 | return &tinfo->conf; | |
734b0e4b MM |
1150 | } |
1151 | ||
7c97f91e MM |
1152 | #else /* !HAVE_LINUX_PERF_EVENT_H */ |
1153 | ||
1154 | /* See linux-btrace.h. */ | |
1155 | ||
1156 | int | |
043c3577 | 1157 | linux_supports_btrace (struct target_ops *ops, enum btrace_format format) |
7c97f91e MM |
1158 | { |
1159 | return 0; | |
1160 | } | |
1161 | ||
1162 | /* See linux-btrace.h. */ | |
1163 | ||
1164 | struct btrace_target_info * | |
f4abbc16 | 1165 | linux_enable_btrace (ptid_t ptid, const struct btrace_config *conf) |
7c97f91e MM |
1166 | { |
1167 | return NULL; | |
1168 | } | |
1169 | ||
1170 | /* See linux-btrace.h. */ | |
1171 | ||
969c39fb | 1172 | enum btrace_error |
7c97f91e MM |
1173 | linux_disable_btrace (struct btrace_target_info *tinfo) |
1174 | { | |
969c39fb | 1175 | return BTRACE_ERR_NOT_SUPPORTED; |
7c97f91e MM |
1176 | } |
1177 | ||
1178 | /* See linux-btrace.h. */ | |
1179 | ||
969c39fb | 1180 | enum btrace_error |
734b0e4b | 1181 | linux_read_btrace (struct btrace_data *btrace, |
969c39fb | 1182 | struct btrace_target_info *tinfo, |
7c97f91e MM |
1183 | enum btrace_read_type type) |
1184 | { | |
969c39fb | 1185 | return BTRACE_ERR_NOT_SUPPORTED; |
7c97f91e MM |
1186 | } |
1187 | ||
f4abbc16 MM |
1188 | /* See linux-btrace.h. */ |
1189 | ||
1190 | const struct btrace_config * | |
1191 | linux_btrace_conf (const struct btrace_target_info *tinfo) | |
1192 | { | |
1193 | return NULL; | |
1194 | } | |
1195 | ||
7c97f91e | 1196 | #endif /* !HAVE_LINUX_PERF_EVENT_H */ |