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7c97f91e MM |
1 | /* Linux-dependent part of branch trace support for GDB, and GDBserver. |
2 | ||
61baf725 | 3 | Copyright (C) 2013-2017 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 | ||
db58b373 MM |
122 | /* We should never ask for more data than the buffer can hold. */ |
123 | buffer_size = pev->size; | |
124 | gdb_assert (size <= buffer_size); | |
125 | ||
126 | /* If we ask for more data than we seem to have, we wrap around and read | |
127 | data from the end of the buffer. This is already handled by the % | |
128 | BUFFER_SIZE operation, below. Here, we just need to make sure that we | |
129 | don't underflow. | |
130 | ||
131 | Note that this is perfectly OK for perf event buffers where data_head | |
132 | doesn'grow indefinitely and instead wraps around to remain within the | |
133 | buffer's boundaries. */ | |
134 | if (data_head < size) | |
135 | data_head += buffer_size; | |
136 | ||
b20a6524 MM |
137 | gdb_assert (size <= data_head); |
138 | data_tail = data_head - size; | |
139 | ||
b20a6524 MM |
140 | begin = pev->mem; |
141 | start = begin + data_tail % buffer_size; | |
142 | stop = begin + data_head % buffer_size; | |
143 | ||
224c3ddb | 144 | buffer = (gdb_byte *) xmalloc (size); |
b20a6524 MM |
145 | |
146 | if (start < stop) | |
147 | memcpy (buffer, start, stop - start); | |
148 | else | |
149 | { | |
150 | end = begin + buffer_size; | |
151 | ||
152 | memcpy (buffer, start, end - start); | |
153 | memcpy (buffer + (end - start), begin, stop - begin); | |
154 | } | |
155 | ||
156 | return buffer; | |
157 | } | |
158 | ||
159 | /* Copy the perf event buffer data from PEV. | |
160 | Store a pointer to the copy into DATA and its size in SIZE. */ | |
161 | ||
162 | static void | |
163 | perf_event_read_all (struct perf_event_buffer *pev, gdb_byte **data, | |
e7b01ce0 | 164 | size_t *psize) |
b20a6524 | 165 | { |
e7b01ce0 MM |
166 | size_t size; |
167 | __u64 data_head; | |
b20a6524 MM |
168 | |
169 | data_head = *pev->data_head; | |
b20a6524 | 170 | size = pev->size; |
b20a6524 MM |
171 | |
172 | *data = perf_event_read (pev, data_head, size); | |
173 | *psize = size; | |
174 | ||
175 | pev->last_head = data_head; | |
176 | } | |
177 | ||
178 | /* Determine the event type. | |
179 | Returns zero on success and fills in TYPE; returns -1 otherwise. */ | |
180 | ||
181 | static int | |
182 | perf_event_pt_event_type (int *type) | |
183 | { | |
184 | FILE *file; | |
185 | int found; | |
186 | ||
187 | file = fopen ("/sys/bus/event_source/devices/intel_pt/type", "r"); | |
188 | if (file == NULL) | |
189 | return -1; | |
190 | ||
191 | found = fscanf (file, "%d", type); | |
192 | ||
193 | fclose (file); | |
194 | ||
195 | if (found == 1) | |
196 | return 0; | |
197 | return -1; | |
198 | } | |
199 | ||
0568462b MM |
200 | /* Try to determine the start address of the Linux kernel. */ |
201 | ||
202 | static uint64_t | |
203 | linux_determine_kernel_start (void) | |
d68e53f4 | 204 | { |
0568462b MM |
205 | static uint64_t kernel_start; |
206 | static int cached; | |
d68e53f4 | 207 | |
0568462b MM |
208 | if (cached != 0) |
209 | return kernel_start; | |
d68e53f4 | 210 | |
0568462b MM |
211 | cached = 1; |
212 | ||
d419f42d | 213 | gdb_file_up file = gdb_fopen_cloexec ("/proc/kallsyms", "r"); |
0568462b MM |
214 | if (file == NULL) |
215 | return kernel_start; | |
216 | ||
d419f42d | 217 | while (!feof (file.get ())) |
0568462b MM |
218 | { |
219 | char buffer[1024], symbol[8], *line; | |
220 | uint64_t addr; | |
221 | int match; | |
222 | ||
d419f42d | 223 | line = fgets (buffer, sizeof (buffer), file.get ()); |
0568462b MM |
224 | if (line == NULL) |
225 | break; | |
d68e53f4 | 226 | |
0568462b MM |
227 | match = sscanf (line, "%" SCNx64 " %*[tT] %7s", &addr, symbol); |
228 | if (match != 2) | |
229 | continue; | |
d68e53f4 | 230 | |
0568462b MM |
231 | if (strcmp (symbol, "_text") == 0) |
232 | { | |
233 | kernel_start = addr; | |
234 | break; | |
235 | } | |
236 | } | |
237 | ||
0568462b | 238 | return kernel_start; |
d68e53f4 MM |
239 | } |
240 | ||
7c97f91e MM |
241 | /* Check whether an address is in the kernel. */ |
242 | ||
243 | static inline int | |
0568462b | 244 | perf_event_is_kernel_addr (uint64_t addr) |
7c97f91e | 245 | { |
0568462b | 246 | uint64_t kernel_start; |
7c97f91e | 247 | |
0568462b MM |
248 | kernel_start = linux_determine_kernel_start (); |
249 | if (kernel_start != 0ull) | |
250 | return (addr >= kernel_start); | |
7c97f91e | 251 | |
0568462b MM |
252 | /* If we don't know the kernel's start address, let's check the most |
253 | significant bit. This will work at least for 64-bit kernels. */ | |
254 | return ((addr & (1ull << 63)) != 0); | |
7c97f91e MM |
255 | } |
256 | ||
257 | /* Check whether a perf event record should be skipped. */ | |
258 | ||
259 | static inline int | |
0568462b | 260 | perf_event_skip_bts_record (const struct perf_event_bts *bts) |
7c97f91e MM |
261 | { |
262 | /* The hardware may report branches from kernel into user space. Branches | |
263 | from user into kernel space will be suppressed. We filter the former to | |
264 | provide a consistent branch trace excluding kernel. */ | |
0568462b | 265 | return perf_event_is_kernel_addr (bts->from); |
7c97f91e MM |
266 | } |
267 | ||
268 | /* Perform a few consistency checks on a perf event sample record. This is | |
269 | meant to catch cases when we get out of sync with the perf event stream. */ | |
270 | ||
271 | static inline int | |
272 | perf_event_sample_ok (const struct perf_event_sample *sample) | |
273 | { | |
274 | if (sample->header.type != PERF_RECORD_SAMPLE) | |
275 | return 0; | |
276 | ||
277 | if (sample->header.size != sizeof (*sample)) | |
278 | return 0; | |
279 | ||
280 | return 1; | |
281 | } | |
282 | ||
283 | /* Branch trace is collected in a circular buffer [begin; end) as pairs of from | |
284 | and to addresses (plus a header). | |
285 | ||
286 | Start points into that buffer at the next sample position. | |
287 | We read the collected samples backwards from start. | |
288 | ||
289 | While reading the samples, we convert the information into a list of blocks. | |
290 | For two adjacent samples s1 and s2, we form a block b such that b.begin = | |
291 | s1.to and b.end = s2.from. | |
292 | ||
293 | In case the buffer overflows during sampling, one sample may have its lower | |
294 | part at the end and its upper part at the beginning of the buffer. */ | |
295 | ||
296 | static VEC (btrace_block_s) * | |
297 | perf_event_read_bts (struct btrace_target_info* tinfo, const uint8_t *begin, | |
e7b01ce0 | 298 | const uint8_t *end, const uint8_t *start, size_t size) |
7c97f91e MM |
299 | { |
300 | VEC (btrace_block_s) *btrace = NULL; | |
301 | struct perf_event_sample sample; | |
e7b01ce0 | 302 | size_t read = 0; |
7c97f91e MM |
303 | struct btrace_block block = { 0, 0 }; |
304 | struct regcache *regcache; | |
305 | ||
306 | gdb_assert (begin <= start); | |
307 | gdb_assert (start <= end); | |
308 | ||
309 | /* The first block ends at the current pc. */ | |
361c8ade | 310 | regcache = get_thread_regcache_for_ptid (tinfo->ptid); |
7c97f91e MM |
311 | block.end = regcache_read_pc (regcache); |
312 | ||
313 | /* The buffer may contain a partial record as its last entry (i.e. when the | |
314 | buffer size is not a multiple of the sample size). */ | |
315 | read = sizeof (sample) - 1; | |
316 | ||
317 | for (; read < size; read += sizeof (sample)) | |
318 | { | |
319 | const struct perf_event_sample *psample; | |
320 | ||
321 | /* Find the next perf_event sample in a backwards traversal. */ | |
322 | start -= sizeof (sample); | |
323 | ||
324 | /* If we're still inside the buffer, we're done. */ | |
325 | if (begin <= start) | |
326 | psample = (const struct perf_event_sample *) start; | |
327 | else | |
328 | { | |
329 | int missing; | |
330 | ||
331 | /* We're to the left of the ring buffer, we will wrap around and | |
332 | reappear at the very right of the ring buffer. */ | |
333 | ||
334 | missing = (begin - start); | |
335 | start = (end - missing); | |
336 | ||
337 | /* If the entire sample is missing, we're done. */ | |
338 | if (missing == sizeof (sample)) | |
339 | psample = (const struct perf_event_sample *) start; | |
340 | else | |
341 | { | |
342 | uint8_t *stack; | |
343 | ||
344 | /* The sample wrapped around. The lower part is at the end and | |
345 | the upper part is at the beginning of the buffer. */ | |
346 | stack = (uint8_t *) &sample; | |
347 | ||
348 | /* Copy the two parts so we have a contiguous sample. */ | |
349 | memcpy (stack, start, missing); | |
350 | memcpy (stack + missing, begin, sizeof (sample) - missing); | |
351 | ||
352 | psample = &sample; | |
353 | } | |
354 | } | |
355 | ||
356 | if (!perf_event_sample_ok (psample)) | |
357 | { | |
358 | warning (_("Branch trace may be incomplete.")); | |
359 | break; | |
360 | } | |
361 | ||
0568462b | 362 | if (perf_event_skip_bts_record (&psample->bts)) |
7c97f91e MM |
363 | continue; |
364 | ||
365 | /* We found a valid sample, so we can complete the current block. */ | |
366 | block.begin = psample->bts.to; | |
367 | ||
368 | VEC_safe_push (btrace_block_s, btrace, &block); | |
369 | ||
370 | /* Start the next block. */ | |
371 | block.end = psample->bts.from; | |
372 | } | |
373 | ||
969c39fb MM |
374 | /* Push the last block (i.e. the first one of inferior execution), as well. |
375 | We don't know where it ends, but we know where it starts. If we're | |
376 | reading delta trace, we can fill in the start address later on. | |
377 | Otherwise we will prune it. */ | |
378 | block.begin = 0; | |
379 | VEC_safe_push (btrace_block_s, btrace, &block); | |
380 | ||
7c97f91e MM |
381 | return btrace; |
382 | } | |
383 | ||
043c3577 | 384 | /* Check whether the kernel supports BTS. */ |
a950d57c MM |
385 | |
386 | static int | |
043c3577 | 387 | kernel_supports_bts (void) |
a950d57c MM |
388 | { |
389 | struct perf_event_attr attr; | |
390 | pid_t child, pid; | |
391 | int status, file; | |
392 | ||
393 | errno = 0; | |
394 | child = fork (); | |
395 | switch (child) | |
396 | { | |
397 | case -1: | |
76fb6829 | 398 | warning (_("test bts: cannot fork: %s."), safe_strerror (errno)); |
a950d57c MM |
399 | return 0; |
400 | ||
401 | case 0: | |
402 | status = ptrace (PTRACE_TRACEME, 0, NULL, NULL); | |
403 | if (status != 0) | |
404 | { | |
043c3577 | 405 | warning (_("test bts: cannot PTRACE_TRACEME: %s."), |
76fb6829 | 406 | safe_strerror (errno)); |
a950d57c MM |
407 | _exit (1); |
408 | } | |
409 | ||
410 | status = raise (SIGTRAP); | |
411 | if (status != 0) | |
412 | { | |
043c3577 | 413 | warning (_("test bts: cannot raise SIGTRAP: %s."), |
76fb6829 | 414 | safe_strerror (errno)); |
a950d57c MM |
415 | _exit (1); |
416 | } | |
417 | ||
418 | _exit (1); | |
419 | ||
420 | default: | |
421 | pid = waitpid (child, &status, 0); | |
422 | if (pid != child) | |
423 | { | |
043c3577 | 424 | warning (_("test bts: bad pid %ld, error: %s."), |
76fb6829 | 425 | (long) pid, safe_strerror (errno)); |
a950d57c MM |
426 | return 0; |
427 | } | |
428 | ||
429 | if (!WIFSTOPPED (status)) | |
430 | { | |
043c3577 | 431 | warning (_("test bts: expected stop. status: %d."), |
a950d57c MM |
432 | status); |
433 | return 0; | |
434 | } | |
435 | ||
436 | memset (&attr, 0, sizeof (attr)); | |
437 | ||
438 | attr.type = PERF_TYPE_HARDWARE; | |
439 | attr.config = PERF_COUNT_HW_BRANCH_INSTRUCTIONS; | |
440 | attr.sample_period = 1; | |
441 | attr.sample_type = PERF_SAMPLE_IP | PERF_SAMPLE_ADDR; | |
442 | attr.exclude_kernel = 1; | |
443 | attr.exclude_hv = 1; | |
444 | attr.exclude_idle = 1; | |
445 | ||
446 | file = syscall (SYS_perf_event_open, &attr, child, -1, -1, 0); | |
447 | if (file >= 0) | |
448 | close (file); | |
449 | ||
450 | kill (child, SIGKILL); | |
451 | ptrace (PTRACE_KILL, child, NULL, NULL); | |
452 | ||
453 | pid = waitpid (child, &status, 0); | |
454 | if (pid != child) | |
455 | { | |
043c3577 | 456 | warning (_("test bts: bad pid %ld, error: %s."), |
76fb6829 | 457 | (long) pid, safe_strerror (errno)); |
a950d57c | 458 | if (!WIFSIGNALED (status)) |
043c3577 | 459 | warning (_("test bts: expected killed. status: %d."), |
a950d57c MM |
460 | status); |
461 | } | |
462 | ||
463 | return (file >= 0); | |
464 | } | |
465 | } | |
466 | ||
bc504a31 | 467 | /* Check whether the kernel supports Intel Processor Trace. */ |
b20a6524 MM |
468 | |
469 | static int | |
470 | kernel_supports_pt (void) | |
471 | { | |
472 | struct perf_event_attr attr; | |
473 | pid_t child, pid; | |
474 | int status, file, type; | |
475 | ||
476 | errno = 0; | |
477 | child = fork (); | |
478 | switch (child) | |
479 | { | |
480 | case -1: | |
76fb6829 | 481 | warning (_("test pt: cannot fork: %s."), safe_strerror (errno)); |
b20a6524 MM |
482 | return 0; |
483 | ||
484 | case 0: | |
485 | status = ptrace (PTRACE_TRACEME, 0, NULL, NULL); | |
486 | if (status != 0) | |
487 | { | |
488 | warning (_("test pt: cannot PTRACE_TRACEME: %s."), | |
76fb6829 | 489 | safe_strerror (errno)); |
b20a6524 MM |
490 | _exit (1); |
491 | } | |
492 | ||
493 | status = raise (SIGTRAP); | |
494 | if (status != 0) | |
495 | { | |
496 | warning (_("test pt: cannot raise SIGTRAP: %s."), | |
76fb6829 | 497 | safe_strerror (errno)); |
b20a6524 MM |
498 | _exit (1); |
499 | } | |
500 | ||
501 | _exit (1); | |
502 | ||
503 | default: | |
504 | pid = waitpid (child, &status, 0); | |
505 | if (pid != child) | |
506 | { | |
507 | warning (_("test pt: bad pid %ld, error: %s."), | |
76fb6829 | 508 | (long) pid, safe_strerror (errno)); |
b20a6524 MM |
509 | return 0; |
510 | } | |
511 | ||
512 | if (!WIFSTOPPED (status)) | |
513 | { | |
514 | warning (_("test pt: expected stop. status: %d."), | |
515 | status); | |
516 | return 0; | |
517 | } | |
518 | ||
519 | status = perf_event_pt_event_type (&type); | |
520 | if (status != 0) | |
521 | file = -1; | |
522 | else | |
523 | { | |
524 | memset (&attr, 0, sizeof (attr)); | |
525 | ||
526 | attr.size = sizeof (attr); | |
527 | attr.type = type; | |
528 | attr.exclude_kernel = 1; | |
529 | attr.exclude_hv = 1; | |
530 | attr.exclude_idle = 1; | |
531 | ||
532 | file = syscall (SYS_perf_event_open, &attr, child, -1, -1, 0); | |
533 | if (file >= 0) | |
534 | close (file); | |
535 | } | |
536 | ||
537 | kill (child, SIGKILL); | |
538 | ptrace (PTRACE_KILL, child, NULL, NULL); | |
539 | ||
540 | pid = waitpid (child, &status, 0); | |
541 | if (pid != child) | |
542 | { | |
543 | warning (_("test pt: bad pid %ld, error: %s."), | |
76fb6829 | 544 | (long) pid, safe_strerror (errno)); |
b20a6524 MM |
545 | if (!WIFSIGNALED (status)) |
546 | warning (_("test pt: expected killed. status: %d."), | |
547 | status); | |
548 | } | |
549 | ||
550 | return (file >= 0); | |
551 | } | |
552 | } | |
553 | ||
043c3577 | 554 | /* Check whether an Intel cpu supports BTS. */ |
a950d57c MM |
555 | |
556 | static int | |
afb778a2 | 557 | intel_supports_bts (const struct btrace_cpu *cpu) |
a950d57c | 558 | { |
afb778a2 | 559 | switch (cpu->family) |
5f8e0b8f MF |
560 | { |
561 | case 0x6: | |
afb778a2 | 562 | switch (cpu->model) |
5f8e0b8f MF |
563 | { |
564 | case 0x1a: /* Nehalem */ | |
565 | case 0x1f: | |
566 | case 0x1e: | |
567 | case 0x2e: | |
568 | case 0x25: /* Westmere */ | |
569 | case 0x2c: | |
570 | case 0x2f: | |
571 | case 0x2a: /* Sandy Bridge */ | |
572 | case 0x2d: | |
573 | case 0x3a: /* Ivy Bridge */ | |
574 | ||
575 | /* AAJ122: LBR, BTM, or BTS records may have incorrect branch | |
576 | "from" information afer an EIST transition, T-states, C1E, or | |
577 | Adaptive Thermal Throttling. */ | |
578 | return 0; | |
579 | } | |
580 | } | |
a950d57c MM |
581 | |
582 | return 1; | |
a950d57c MM |
583 | } |
584 | ||
043c3577 | 585 | /* Check whether the cpu supports BTS. */ |
a950d57c MM |
586 | |
587 | static int | |
043c3577 | 588 | cpu_supports_bts (void) |
a950d57c | 589 | { |
afb778a2 | 590 | struct btrace_cpu cpu; |
a950d57c | 591 | |
afb778a2 MM |
592 | cpu = btrace_this_cpu (); |
593 | switch (cpu.vendor) | |
594 | { | |
595 | default: | |
596 | /* Don't know about others. Let's assume they do. */ | |
597 | return 1; | |
a950d57c | 598 | |
afb778a2 MM |
599 | case CV_INTEL: |
600 | return intel_supports_bts (&cpu); | |
601 | } | |
a950d57c MM |
602 | } |
603 | ||
043c3577 | 604 | /* Check whether the linux target supports BTS. */ |
7c97f91e | 605 | |
043c3577 MM |
606 | static int |
607 | linux_supports_bts (void) | |
7c97f91e | 608 | { |
a950d57c MM |
609 | static int cached; |
610 | ||
611 | if (cached == 0) | |
612 | { | |
043c3577 | 613 | if (!kernel_supports_bts ()) |
a950d57c | 614 | cached = -1; |
043c3577 | 615 | else if (!cpu_supports_bts ()) |
a950d57c MM |
616 | cached = -1; |
617 | else | |
618 | cached = 1; | |
619 | } | |
620 | ||
621 | return cached > 0; | |
7c97f91e MM |
622 | } |
623 | ||
bc504a31 | 624 | /* Check whether the linux target supports Intel Processor Trace. */ |
b20a6524 MM |
625 | |
626 | static int | |
627 | linux_supports_pt (void) | |
628 | { | |
629 | static int cached; | |
630 | ||
631 | if (cached == 0) | |
632 | { | |
633 | if (!kernel_supports_pt ()) | |
634 | cached = -1; | |
635 | else | |
636 | cached = 1; | |
637 | } | |
638 | ||
639 | return cached > 0; | |
640 | } | |
641 | ||
7c97f91e MM |
642 | /* See linux-btrace.h. */ |
643 | ||
043c3577 MM |
644 | int |
645 | linux_supports_btrace (struct target_ops *ops, enum btrace_format format) | |
646 | { | |
647 | switch (format) | |
648 | { | |
649 | case BTRACE_FORMAT_NONE: | |
650 | return 0; | |
651 | ||
652 | case BTRACE_FORMAT_BTS: | |
653 | return linux_supports_bts (); | |
b20a6524 MM |
654 | |
655 | case BTRACE_FORMAT_PT: | |
656 | return linux_supports_pt (); | |
043c3577 MM |
657 | } |
658 | ||
659 | internal_error (__FILE__, __LINE__, _("Unknown branch trace format")); | |
660 | } | |
661 | ||
f4abbc16 | 662 | /* Enable branch tracing in BTS format. */ |
043c3577 | 663 | |
f4abbc16 | 664 | static struct btrace_target_info * |
d33501a5 | 665 | linux_enable_bts (ptid_t ptid, const struct btrace_config_bts *conf) |
7c97f91e | 666 | { |
aadf7753 | 667 | struct perf_event_mmap_page *header; |
7c97f91e | 668 | struct btrace_target_info *tinfo; |
f4abbc16 | 669 | struct btrace_tinfo_bts *bts; |
e7b01ce0 MM |
670 | size_t size, pages; |
671 | __u64 data_offset; | |
d0fa7535 | 672 | int pid, pg; |
7c97f91e | 673 | |
8d749320 | 674 | tinfo = XCNEW (struct btrace_target_info); |
7c97f91e MM |
675 | tinfo->ptid = ptid; |
676 | ||
f4abbc16 MM |
677 | tinfo->conf.format = BTRACE_FORMAT_BTS; |
678 | bts = &tinfo->variant.bts; | |
7c97f91e | 679 | |
f4abbc16 MM |
680 | bts->attr.size = sizeof (bts->attr); |
681 | bts->attr.type = PERF_TYPE_HARDWARE; | |
682 | bts->attr.config = PERF_COUNT_HW_BRANCH_INSTRUCTIONS; | |
683 | bts->attr.sample_period = 1; | |
7c97f91e | 684 | |
f4abbc16 MM |
685 | /* We sample from and to address. */ |
686 | bts->attr.sample_type = PERF_SAMPLE_IP | PERF_SAMPLE_ADDR; | |
7c97f91e | 687 | |
f4abbc16 MM |
688 | bts->attr.exclude_kernel = 1; |
689 | bts->attr.exclude_hv = 1; | |
690 | bts->attr.exclude_idle = 1; | |
7c97f91e MM |
691 | |
692 | pid = ptid_get_lwp (ptid); | |
693 | if (pid == 0) | |
694 | pid = ptid_get_pid (ptid); | |
695 | ||
696 | errno = 0; | |
f4abbc16 MM |
697 | bts->file = syscall (SYS_perf_event_open, &bts->attr, pid, -1, -1, 0); |
698 | if (bts->file < 0) | |
b20a6524 | 699 | goto err_out; |
7c97f91e | 700 | |
d33501a5 | 701 | /* Convert the requested size in bytes to pages (rounding up). */ |
e7b01ce0 MM |
702 | pages = ((size_t) conf->size / PAGE_SIZE |
703 | + ((conf->size % PAGE_SIZE) == 0 ? 0 : 1)); | |
d33501a5 MM |
704 | /* We need at least one page. */ |
705 | if (pages == 0) | |
706 | pages = 1; | |
707 | ||
708 | /* The buffer size can be requested in powers of two pages. Adjust PAGES | |
709 | to the next power of two. */ | |
e7b01ce0 MM |
710 | for (pg = 0; pages != ((size_t) 1 << pg); ++pg) |
711 | if ((pages & ((size_t) 1 << pg)) != 0) | |
712 | pages += ((size_t) 1 << pg); | |
d33501a5 MM |
713 | |
714 | /* We try to allocate the requested size. | |
715 | If that fails, try to get as much as we can. */ | |
716 | for (; pages > 0; pages >>= 1) | |
d0fa7535 | 717 | { |
d33501a5 | 718 | size_t length; |
e7b01ce0 | 719 | __u64 data_size; |
d33501a5 | 720 | |
e7b01ce0 MM |
721 | data_size = (__u64) pages * PAGE_SIZE; |
722 | ||
723 | /* Don't ask for more than we can represent in the configuration. */ | |
724 | if ((__u64) UINT_MAX < data_size) | |
725 | continue; | |
726 | ||
727 | size = (size_t) data_size; | |
d33501a5 MM |
728 | length = size + PAGE_SIZE; |
729 | ||
730 | /* Check for overflows. */ | |
e7b01ce0 | 731 | if ((__u64) length != data_size + PAGE_SIZE) |
d33501a5 MM |
732 | continue; |
733 | ||
d0fa7535 | 734 | /* The number of pages we request needs to be a power of two. */ |
224c3ddb SM |
735 | header = ((struct perf_event_mmap_page *) |
736 | mmap (NULL, length, PROT_READ, MAP_SHARED, bts->file, 0)); | |
aadf7753 MM |
737 | if (header != MAP_FAILED) |
738 | break; | |
d0fa7535 | 739 | } |
7c97f91e | 740 | |
010a18a1 | 741 | if (pages == 0) |
aadf7753 MM |
742 | goto err_file; |
743 | ||
010a18a1 | 744 | data_offset = PAGE_SIZE; |
010a18a1 MM |
745 | |
746 | #if defined (PERF_ATTR_SIZE_VER5) | |
747 | if (offsetof (struct perf_event_mmap_page, data_size) <= header->size) | |
748 | { | |
e7b01ce0 MM |
749 | __u64 data_size; |
750 | ||
010a18a1 MM |
751 | data_offset = header->data_offset; |
752 | data_size = header->data_size; | |
e7b01ce0 MM |
753 | |
754 | size = (unsigned int) data_size; | |
755 | ||
756 | /* Check for overflows. */ | |
757 | if ((__u64) size != data_size) | |
758 | { | |
759 | munmap ((void *) header, size + PAGE_SIZE); | |
760 | goto err_file; | |
761 | } | |
010a18a1 MM |
762 | } |
763 | #endif /* defined (PERF_ATTR_SIZE_VER5) */ | |
764 | ||
f4abbc16 | 765 | bts->header = header; |
010a18a1 | 766 | bts->bts.mem = ((const uint8_t *) header) + data_offset; |
e7b01ce0 | 767 | bts->bts.size = size; |
f4abbc16 | 768 | bts->bts.data_head = &header->data_head; |
e7b01ce0 | 769 | bts->bts.last_head = 0ull; |
aadf7753 | 770 | |
e7b01ce0 | 771 | tinfo->conf.bts.size = (unsigned int) size; |
aadf7753 MM |
772 | return tinfo; |
773 | ||
774 | err_file: | |
d0fa7535 | 775 | /* We were not able to allocate any buffer. */ |
f4abbc16 | 776 | close (bts->file); |
7c97f91e | 777 | |
b20a6524 MM |
778 | err_out: |
779 | xfree (tinfo); | |
780 | return NULL; | |
781 | } | |
782 | ||
783 | #if defined (PERF_ATTR_SIZE_VER5) | |
784 | ||
bc504a31 | 785 | /* Enable branch tracing in Intel Processor Trace format. */ |
b20a6524 MM |
786 | |
787 | static struct btrace_target_info * | |
788 | linux_enable_pt (ptid_t ptid, const struct btrace_config_pt *conf) | |
789 | { | |
790 | struct perf_event_mmap_page *header; | |
791 | struct btrace_target_info *tinfo; | |
792 | struct btrace_tinfo_pt *pt; | |
e7b01ce0 | 793 | size_t pages, size; |
b20a6524 MM |
794 | int pid, pg, errcode, type; |
795 | ||
796 | if (conf->size == 0) | |
797 | return NULL; | |
798 | ||
799 | errcode = perf_event_pt_event_type (&type); | |
800 | if (errcode != 0) | |
801 | return NULL; | |
802 | ||
803 | pid = ptid_get_lwp (ptid); | |
804 | if (pid == 0) | |
805 | pid = ptid_get_pid (ptid); | |
806 | ||
8d749320 | 807 | tinfo = XCNEW (struct btrace_target_info); |
b20a6524 | 808 | tinfo->ptid = ptid; |
b20a6524 MM |
809 | |
810 | tinfo->conf.format = BTRACE_FORMAT_PT; | |
811 | pt = &tinfo->variant.pt; | |
812 | ||
813 | pt->attr.size = sizeof (pt->attr); | |
814 | pt->attr.type = type; | |
815 | ||
816 | pt->attr.exclude_kernel = 1; | |
817 | pt->attr.exclude_hv = 1; | |
818 | pt->attr.exclude_idle = 1; | |
819 | ||
820 | errno = 0; | |
821 | pt->file = syscall (SYS_perf_event_open, &pt->attr, pid, -1, -1, 0); | |
822 | if (pt->file < 0) | |
823 | goto err; | |
824 | ||
825 | /* Allocate the configuration page. */ | |
a55515ee SM |
826 | header = ((struct perf_event_mmap_page *) |
827 | mmap (NULL, PAGE_SIZE, PROT_READ | PROT_WRITE, MAP_SHARED, | |
828 | pt->file, 0)); | |
b20a6524 MM |
829 | if (header == MAP_FAILED) |
830 | goto err_file; | |
831 | ||
832 | header->aux_offset = header->data_offset + header->data_size; | |
833 | ||
834 | /* Convert the requested size in bytes to pages (rounding up). */ | |
e7b01ce0 MM |
835 | pages = ((size_t) conf->size / PAGE_SIZE |
836 | + ((conf->size % PAGE_SIZE) == 0 ? 0 : 1)); | |
b20a6524 MM |
837 | /* We need at least one page. */ |
838 | if (pages == 0) | |
839 | pages = 1; | |
840 | ||
841 | /* The buffer size can be requested in powers of two pages. Adjust PAGES | |
842 | to the next power of two. */ | |
e7b01ce0 MM |
843 | for (pg = 0; pages != ((size_t) 1 << pg); ++pg) |
844 | if ((pages & ((size_t) 1 << pg)) != 0) | |
845 | pages += ((size_t) 1 << pg); | |
b20a6524 MM |
846 | |
847 | /* We try to allocate the requested size. | |
848 | If that fails, try to get as much as we can. */ | |
849 | for (; pages > 0; pages >>= 1) | |
850 | { | |
851 | size_t length; | |
e7b01ce0 | 852 | __u64 data_size; |
b20a6524 | 853 | |
e7b01ce0 MM |
854 | data_size = (__u64) pages * PAGE_SIZE; |
855 | ||
856 | /* Don't ask for more than we can represent in the configuration. */ | |
857 | if ((__u64) UINT_MAX < data_size) | |
858 | continue; | |
859 | ||
860 | size = (size_t) data_size; | |
b20a6524 MM |
861 | |
862 | /* Check for overflows. */ | |
e7b01ce0 | 863 | if ((__u64) size != data_size) |
b20a6524 MM |
864 | continue; |
865 | ||
e7b01ce0 MM |
866 | header->aux_size = data_size; |
867 | length = size; | |
b20a6524 | 868 | |
a55515ee SM |
869 | pt->pt.mem = ((const uint8_t *) |
870 | mmap (NULL, length, PROT_READ, MAP_SHARED, pt->file, | |
871 | header->aux_offset)); | |
b20a6524 MM |
872 | if (pt->pt.mem != MAP_FAILED) |
873 | break; | |
874 | } | |
875 | ||
876 | if (pages == 0) | |
877 | goto err_conf; | |
878 | ||
879 | pt->header = header; | |
880 | pt->pt.size = size; | |
881 | pt->pt.data_head = &header->aux_head; | |
882 | ||
e7b01ce0 | 883 | tinfo->conf.pt.size = (unsigned int) size; |
b20a6524 MM |
884 | return tinfo; |
885 | ||
886 | err_conf: | |
887 | munmap((void *) header, PAGE_SIZE); | |
888 | ||
889 | err_file: | |
890 | close (pt->file); | |
891 | ||
7c97f91e MM |
892 | err: |
893 | xfree (tinfo); | |
894 | return NULL; | |
895 | } | |
896 | ||
b20a6524 MM |
897 | #else /* !defined (PERF_ATTR_SIZE_VER5) */ |
898 | ||
899 | static struct btrace_target_info * | |
900 | linux_enable_pt (ptid_t ptid, const struct btrace_config_pt *conf) | |
901 | { | |
902 | errno = EOPNOTSUPP; | |
903 | return NULL; | |
904 | } | |
905 | ||
906 | #endif /* !defined (PERF_ATTR_SIZE_VER5) */ | |
907 | ||
7c97f91e MM |
908 | /* See linux-btrace.h. */ |
909 | ||
f4abbc16 MM |
910 | struct btrace_target_info * |
911 | linux_enable_btrace (ptid_t ptid, const struct btrace_config *conf) | |
912 | { | |
913 | struct btrace_target_info *tinfo; | |
914 | ||
915 | tinfo = NULL; | |
916 | switch (conf->format) | |
917 | { | |
918 | case BTRACE_FORMAT_NONE: | |
919 | break; | |
920 | ||
921 | case BTRACE_FORMAT_BTS: | |
d33501a5 | 922 | tinfo = linux_enable_bts (ptid, &conf->bts); |
f4abbc16 | 923 | break; |
b20a6524 MM |
924 | |
925 | case BTRACE_FORMAT_PT: | |
926 | tinfo = linux_enable_pt (ptid, &conf->pt); | |
927 | break; | |
f4abbc16 MM |
928 | } |
929 | ||
930 | return tinfo; | |
931 | } | |
932 | ||
933 | /* Disable BTS tracing. */ | |
934 | ||
935 | static enum btrace_error | |
936 | linux_disable_bts (struct btrace_tinfo_bts *tinfo) | |
7c97f91e | 937 | { |
aadf7753 | 938 | munmap((void *) tinfo->header, tinfo->bts.size + PAGE_SIZE); |
7c97f91e | 939 | close (tinfo->file); |
7c97f91e | 940 | |
969c39fb | 941 | return BTRACE_ERR_NONE; |
7c97f91e MM |
942 | } |
943 | ||
bc504a31 | 944 | /* Disable Intel Processor Trace tracing. */ |
b20a6524 MM |
945 | |
946 | static enum btrace_error | |
947 | linux_disable_pt (struct btrace_tinfo_pt *tinfo) | |
948 | { | |
949 | munmap((void *) tinfo->pt.mem, tinfo->pt.size); | |
950 | munmap((void *) tinfo->header, PAGE_SIZE); | |
951 | close (tinfo->file); | |
952 | ||
953 | return BTRACE_ERR_NONE; | |
954 | } | |
955 | ||
f4abbc16 MM |
956 | /* See linux-btrace.h. */ |
957 | ||
958 | enum btrace_error | |
959 | linux_disable_btrace (struct btrace_target_info *tinfo) | |
960 | { | |
961 | enum btrace_error errcode; | |
962 | ||
963 | errcode = BTRACE_ERR_NOT_SUPPORTED; | |
964 | switch (tinfo->conf.format) | |
965 | { | |
966 | case BTRACE_FORMAT_NONE: | |
967 | break; | |
968 | ||
969 | case BTRACE_FORMAT_BTS: | |
970 | errcode = linux_disable_bts (&tinfo->variant.bts); | |
971 | break; | |
b20a6524 MM |
972 | |
973 | case BTRACE_FORMAT_PT: | |
974 | errcode = linux_disable_pt (&tinfo->variant.pt); | |
975 | break; | |
f4abbc16 MM |
976 | } |
977 | ||
978 | if (errcode == BTRACE_ERR_NONE) | |
979 | xfree (tinfo); | |
980 | ||
981 | return errcode; | |
982 | } | |
983 | ||
734b0e4b MM |
984 | /* Read branch trace data in BTS format for the thread given by TINFO into |
985 | BTRACE using the TYPE reading method. */ | |
7c97f91e | 986 | |
734b0e4b MM |
987 | static enum btrace_error |
988 | linux_read_bts (struct btrace_data_bts *btrace, | |
989 | struct btrace_target_info *tinfo, | |
990 | enum btrace_read_type type) | |
7c97f91e | 991 | { |
aadf7753 | 992 | struct perf_event_buffer *pevent; |
7c97f91e | 993 | const uint8_t *begin, *end, *start; |
e7b01ce0 MM |
994 | size_t buffer_size, size; |
995 | __u64 data_head, data_tail; | |
aadf7753 MM |
996 | unsigned int retries = 5; |
997 | ||
f4abbc16 | 998 | pevent = &tinfo->variant.bts.bts; |
7c97f91e | 999 | |
969c39fb MM |
1000 | /* For delta reads, we return at least the partial last block containing |
1001 | the current PC. */ | |
aadf7753 | 1002 | if (type == BTRACE_READ_NEW && !perf_event_new_data (pevent)) |
969c39fb | 1003 | return BTRACE_ERR_NONE; |
7c97f91e | 1004 | |
aadf7753 MM |
1005 | buffer_size = pevent->size; |
1006 | data_tail = pevent->last_head; | |
7c97f91e MM |
1007 | |
1008 | /* We may need to retry reading the trace. See below. */ | |
1009 | while (retries--) | |
1010 | { | |
aadf7753 | 1011 | data_head = *pevent->data_head; |
7c97f91e | 1012 | |
ed9edfb5 | 1013 | /* Delete any leftover trace from the previous iteration. */ |
734b0e4b | 1014 | VEC_free (btrace_block_s, btrace->blocks); |
ed9edfb5 | 1015 | |
969c39fb | 1016 | if (type == BTRACE_READ_DELTA) |
7c97f91e | 1017 | { |
e7b01ce0 MM |
1018 | __u64 data_size; |
1019 | ||
969c39fb MM |
1020 | /* Determine the number of bytes to read and check for buffer |
1021 | overflows. */ | |
1022 | ||
1023 | /* Check for data head overflows. We might be able to recover from | |
1024 | those but they are very unlikely and it's not really worth the | |
1025 | effort, I think. */ | |
1026 | if (data_head < data_tail) | |
1027 | return BTRACE_ERR_OVERFLOW; | |
1028 | ||
1029 | /* If the buffer is smaller than the trace delta, we overflowed. */ | |
e7b01ce0 MM |
1030 | data_size = data_head - data_tail; |
1031 | if (buffer_size < data_size) | |
969c39fb | 1032 | return BTRACE_ERR_OVERFLOW; |
e7b01ce0 MM |
1033 | |
1034 | /* DATA_SIZE <= BUFFER_SIZE and therefore fits into a size_t. */ | |
1035 | size = (size_t) data_size; | |
969c39fb MM |
1036 | } |
1037 | else | |
1038 | { | |
1039 | /* Read the entire buffer. */ | |
1040 | size = buffer_size; | |
7c97f91e | 1041 | |
969c39fb MM |
1042 | /* Adjust the size if the buffer has not overflowed, yet. */ |
1043 | if (data_head < size) | |
e7b01ce0 | 1044 | size = (size_t) data_head; |
7c97f91e MM |
1045 | } |
1046 | ||
969c39fb | 1047 | /* Data_head keeps growing; the buffer itself is circular. */ |
aadf7753 | 1048 | begin = pevent->mem; |
969c39fb MM |
1049 | start = begin + data_head % buffer_size; |
1050 | ||
1051 | if (data_head <= buffer_size) | |
1052 | end = start; | |
1053 | else | |
aadf7753 | 1054 | end = begin + pevent->size; |
969c39fb | 1055 | |
734b0e4b | 1056 | btrace->blocks = perf_event_read_bts (tinfo, begin, end, start, size); |
969c39fb | 1057 | |
7c97f91e MM |
1058 | /* The stopping thread notifies its ptracer before it is scheduled out. |
1059 | On multi-core systems, the debugger might therefore run while the | |
1060 | kernel might be writing the last branch trace records. | |
1061 | ||
1062 | Let's check whether the data head moved while we read the trace. */ | |
aadf7753 | 1063 | if (data_head == *pevent->data_head) |
7c97f91e MM |
1064 | break; |
1065 | } | |
1066 | ||
aadf7753 | 1067 | pevent->last_head = data_head; |
7c97f91e | 1068 | |
969c39fb MM |
1069 | /* Prune the incomplete last block (i.e. the first one of inferior execution) |
1070 | if we're not doing a delta read. There is no way of filling in its zeroed | |
1071 | BEGIN element. */ | |
734b0e4b MM |
1072 | if (!VEC_empty (btrace_block_s, btrace->blocks) |
1073 | && type != BTRACE_READ_DELTA) | |
1074 | VEC_pop (btrace_block_s, btrace->blocks); | |
969c39fb MM |
1075 | |
1076 | return BTRACE_ERR_NONE; | |
7c97f91e MM |
1077 | } |
1078 | ||
bc504a31 | 1079 | /* Fill in the Intel Processor Trace configuration information. */ |
b20a6524 MM |
1080 | |
1081 | static void | |
1082 | linux_fill_btrace_pt_config (struct btrace_data_pt_config *conf) | |
1083 | { | |
1084 | conf->cpu = btrace_this_cpu (); | |
1085 | } | |
1086 | ||
bc504a31 | 1087 | /* Read branch trace data in Intel Processor Trace format for the thread |
b20a6524 MM |
1088 | given by TINFO into BTRACE using the TYPE reading method. */ |
1089 | ||
1090 | static enum btrace_error | |
1091 | linux_read_pt (struct btrace_data_pt *btrace, | |
1092 | struct btrace_target_info *tinfo, | |
1093 | enum btrace_read_type type) | |
1094 | { | |
1095 | struct perf_event_buffer *pt; | |
1096 | ||
1097 | pt = &tinfo->variant.pt.pt; | |
1098 | ||
1099 | linux_fill_btrace_pt_config (&btrace->config); | |
1100 | ||
1101 | switch (type) | |
1102 | { | |
1103 | case BTRACE_READ_DELTA: | |
1104 | /* We don't support delta reads. The data head (i.e. aux_head) wraps | |
1105 | around to stay inside the aux buffer. */ | |
1106 | return BTRACE_ERR_NOT_SUPPORTED; | |
1107 | ||
1108 | case BTRACE_READ_NEW: | |
1109 | if (!perf_event_new_data (pt)) | |
1110 | return BTRACE_ERR_NONE; | |
1111 | ||
1112 | /* Fall through. */ | |
1113 | case BTRACE_READ_ALL: | |
1114 | perf_event_read_all (pt, &btrace->data, &btrace->size); | |
1115 | return BTRACE_ERR_NONE; | |
1116 | } | |
1117 | ||
1118 | internal_error (__FILE__, __LINE__, _("Unkown btrace read type.")); | |
1119 | } | |
1120 | ||
734b0e4b MM |
1121 | /* See linux-btrace.h. */ |
1122 | ||
1123 | enum btrace_error | |
1124 | linux_read_btrace (struct btrace_data *btrace, | |
1125 | struct btrace_target_info *tinfo, | |
1126 | enum btrace_read_type type) | |
1127 | { | |
f4abbc16 MM |
1128 | switch (tinfo->conf.format) |
1129 | { | |
1130 | case BTRACE_FORMAT_NONE: | |
1131 | return BTRACE_ERR_NOT_SUPPORTED; | |
1132 | ||
1133 | case BTRACE_FORMAT_BTS: | |
1134 | /* We read btrace in BTS format. */ | |
1135 | btrace->format = BTRACE_FORMAT_BTS; | |
1136 | btrace->variant.bts.blocks = NULL; | |
1137 | ||
1138 | return linux_read_bts (&btrace->variant.bts, tinfo, type); | |
b20a6524 MM |
1139 | |
1140 | case BTRACE_FORMAT_PT: | |
bc504a31 | 1141 | /* We read btrace in Intel Processor Trace format. */ |
b20a6524 MM |
1142 | btrace->format = BTRACE_FORMAT_PT; |
1143 | btrace->variant.pt.data = NULL; | |
1144 | btrace->variant.pt.size = 0; | |
1145 | ||
1146 | return linux_read_pt (&btrace->variant.pt, tinfo, type); | |
f4abbc16 MM |
1147 | } |
1148 | ||
1149 | internal_error (__FILE__, __LINE__, _("Unkown branch trace format.")); | |
1150 | } | |
1151 | ||
1152 | /* See linux-btrace.h. */ | |
734b0e4b | 1153 | |
f4abbc16 MM |
1154 | const struct btrace_config * |
1155 | linux_btrace_conf (const struct btrace_target_info *tinfo) | |
1156 | { | |
1157 | return &tinfo->conf; | |
734b0e4b MM |
1158 | } |
1159 | ||
7c97f91e MM |
1160 | #else /* !HAVE_LINUX_PERF_EVENT_H */ |
1161 | ||
1162 | /* See linux-btrace.h. */ | |
1163 | ||
1164 | int | |
043c3577 | 1165 | linux_supports_btrace (struct target_ops *ops, enum btrace_format format) |
7c97f91e MM |
1166 | { |
1167 | return 0; | |
1168 | } | |
1169 | ||
1170 | /* See linux-btrace.h. */ | |
1171 | ||
1172 | struct btrace_target_info * | |
f4abbc16 | 1173 | linux_enable_btrace (ptid_t ptid, const struct btrace_config *conf) |
7c97f91e MM |
1174 | { |
1175 | return NULL; | |
1176 | } | |
1177 | ||
1178 | /* See linux-btrace.h. */ | |
1179 | ||
969c39fb | 1180 | enum btrace_error |
7c97f91e MM |
1181 | linux_disable_btrace (struct btrace_target_info *tinfo) |
1182 | { | |
969c39fb | 1183 | return BTRACE_ERR_NOT_SUPPORTED; |
7c97f91e MM |
1184 | } |
1185 | ||
1186 | /* See linux-btrace.h. */ | |
1187 | ||
969c39fb | 1188 | enum btrace_error |
734b0e4b | 1189 | linux_read_btrace (struct btrace_data *btrace, |
969c39fb | 1190 | struct btrace_target_info *tinfo, |
7c97f91e MM |
1191 | enum btrace_read_type type) |
1192 | { | |
969c39fb | 1193 | return BTRACE_ERR_NOT_SUPPORTED; |
7c97f91e MM |
1194 | } |
1195 | ||
f4abbc16 MM |
1196 | /* See linux-btrace.h. */ |
1197 | ||
1198 | const struct btrace_config * | |
1199 | linux_btrace_conf (const struct btrace_target_info *tinfo) | |
1200 | { | |
1201 | return NULL; | |
1202 | } | |
1203 | ||
7c97f91e | 1204 | #endif /* !HAVE_LINUX_PERF_EVENT_H */ |