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7c97f91e MM |
1 | /* Linux-dependent part of branch trace support for GDB, and GDBserver. |
2 | ||
e2882c85 | 3 | Copyright (C) 2013-2018 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 | 31 | #include <sys/syscall.h> |
5b4e221c MF |
32 | |
33 | #if HAVE_LINUX_PERF_EVENT_H && defined(SYS_perf_event_open) | |
7c97f91e | 34 | #include <unistd.h> |
7c97f91e MM |
35 | #include <sys/mman.h> |
36 | #include <sys/user.h> | |
5826e159 | 37 | #include "nat/gdb_ptrace.h" |
a950d57c | 38 | #include <sys/types.h> |
a950d57c | 39 | #include <signal.h> |
7c97f91e MM |
40 | |
41 | /* A branch trace record in perf_event. */ | |
42 | struct perf_event_bts | |
43 | { | |
44 | /* The linear address of the branch source. */ | |
45 | uint64_t from; | |
46 | ||
47 | /* The linear address of the branch destination. */ | |
48 | uint64_t to; | |
49 | }; | |
50 | ||
51 | /* A perf_event branch trace sample. */ | |
52 | struct perf_event_sample | |
53 | { | |
54 | /* The perf_event sample header. */ | |
55 | struct perf_event_header header; | |
56 | ||
57 | /* The perf_event branch tracing payload. */ | |
58 | struct perf_event_bts bts; | |
59 | }; | |
60 | ||
afb778a2 MM |
61 | /* Identify the cpu we're running on. */ |
62 | static struct btrace_cpu | |
63 | btrace_this_cpu (void) | |
64 | { | |
65 | struct btrace_cpu cpu; | |
66 | unsigned int eax, ebx, ecx, edx; | |
67 | int ok; | |
68 | ||
69 | memset (&cpu, 0, sizeof (cpu)); | |
70 | ||
71 | ok = x86_cpuid (0, &eax, &ebx, &ecx, &edx); | |
72 | if (ok != 0) | |
73 | { | |
74 | if (ebx == signature_INTEL_ebx && ecx == signature_INTEL_ecx | |
75 | && edx == signature_INTEL_edx) | |
76 | { | |
77 | unsigned int cpuid, ignore; | |
78 | ||
79 | ok = x86_cpuid (1, &cpuid, &ignore, &ignore, &ignore); | |
80 | if (ok != 0) | |
81 | { | |
82 | cpu.vendor = CV_INTEL; | |
83 | ||
84 | cpu.family = (cpuid >> 8) & 0xf; | |
85 | cpu.model = (cpuid >> 4) & 0xf; | |
86 | ||
87 | if (cpu.family == 0x6) | |
88 | cpu.model += (cpuid >> 12) & 0xf0; | |
89 | } | |
90 | } | |
91 | } | |
92 | ||
93 | return cpu; | |
94 | } | |
95 | ||
aadf7753 | 96 | /* Return non-zero if there is new data in PEVENT; zero otherwise. */ |
7c97f91e | 97 | |
aadf7753 MM |
98 | static int |
99 | perf_event_new_data (const struct perf_event_buffer *pev) | |
7c97f91e | 100 | { |
aadf7753 | 101 | return *pev->data_head != pev->last_head; |
7c97f91e MM |
102 | } |
103 | ||
b20a6524 MM |
104 | /* Copy the last SIZE bytes from PEV ending at DATA_HEAD and return a pointer |
105 | to the memory holding the copy. | |
106 | The caller is responsible for freeing the memory. */ | |
107 | ||
108 | static gdb_byte * | |
e7b01ce0 MM |
109 | perf_event_read (const struct perf_event_buffer *pev, __u64 data_head, |
110 | size_t size) | |
b20a6524 MM |
111 | { |
112 | const gdb_byte *begin, *end, *start, *stop; | |
113 | gdb_byte *buffer; | |
e7b01ce0 MM |
114 | size_t buffer_size; |
115 | __u64 data_tail; | |
b20a6524 MM |
116 | |
117 | if (size == 0) | |
118 | return NULL; | |
119 | ||
db58b373 MM |
120 | /* We should never ask for more data than the buffer can hold. */ |
121 | buffer_size = pev->size; | |
122 | gdb_assert (size <= buffer_size); | |
123 | ||
124 | /* If we ask for more data than we seem to have, we wrap around and read | |
125 | data from the end of the buffer. This is already handled by the % | |
126 | BUFFER_SIZE operation, below. Here, we just need to make sure that we | |
127 | don't underflow. | |
128 | ||
129 | Note that this is perfectly OK for perf event buffers where data_head | |
130 | doesn'grow indefinitely and instead wraps around to remain within the | |
131 | buffer's boundaries. */ | |
132 | if (data_head < size) | |
133 | data_head += buffer_size; | |
134 | ||
b20a6524 MM |
135 | gdb_assert (size <= data_head); |
136 | data_tail = data_head - size; | |
137 | ||
b20a6524 MM |
138 | begin = pev->mem; |
139 | start = begin + data_tail % buffer_size; | |
140 | stop = begin + data_head % buffer_size; | |
141 | ||
224c3ddb | 142 | buffer = (gdb_byte *) xmalloc (size); |
b20a6524 MM |
143 | |
144 | if (start < stop) | |
145 | memcpy (buffer, start, stop - start); | |
146 | else | |
147 | { | |
148 | end = begin + buffer_size; | |
149 | ||
150 | memcpy (buffer, start, end - start); | |
151 | memcpy (buffer + (end - start), begin, stop - begin); | |
152 | } | |
153 | ||
154 | return buffer; | |
155 | } | |
156 | ||
157 | /* Copy the perf event buffer data from PEV. | |
158 | Store a pointer to the copy into DATA and its size in SIZE. */ | |
159 | ||
160 | static void | |
161 | perf_event_read_all (struct perf_event_buffer *pev, gdb_byte **data, | |
e7b01ce0 | 162 | size_t *psize) |
b20a6524 | 163 | { |
e7b01ce0 MM |
164 | size_t size; |
165 | __u64 data_head; | |
b20a6524 MM |
166 | |
167 | data_head = *pev->data_head; | |
b20a6524 | 168 | size = pev->size; |
b20a6524 MM |
169 | |
170 | *data = perf_event_read (pev, data_head, size); | |
171 | *psize = size; | |
172 | ||
173 | pev->last_head = data_head; | |
174 | } | |
175 | ||
176 | /* Determine the event type. | |
177 | Returns zero on success and fills in TYPE; returns -1 otherwise. */ | |
178 | ||
179 | static int | |
180 | perf_event_pt_event_type (int *type) | |
181 | { | |
182 | FILE *file; | |
183 | int found; | |
184 | ||
185 | file = fopen ("/sys/bus/event_source/devices/intel_pt/type", "r"); | |
186 | if (file == NULL) | |
187 | return -1; | |
188 | ||
189 | found = fscanf (file, "%d", type); | |
190 | ||
191 | fclose (file); | |
192 | ||
193 | if (found == 1) | |
194 | return 0; | |
195 | return -1; | |
196 | } | |
197 | ||
0568462b MM |
198 | /* Try to determine the start address of the Linux kernel. */ |
199 | ||
200 | static uint64_t | |
201 | linux_determine_kernel_start (void) | |
d68e53f4 | 202 | { |
0568462b MM |
203 | static uint64_t kernel_start; |
204 | static int cached; | |
d68e53f4 | 205 | |
0568462b MM |
206 | if (cached != 0) |
207 | return kernel_start; | |
d68e53f4 | 208 | |
0568462b MM |
209 | cached = 1; |
210 | ||
d419f42d | 211 | gdb_file_up file = gdb_fopen_cloexec ("/proc/kallsyms", "r"); |
0568462b MM |
212 | if (file == NULL) |
213 | return kernel_start; | |
214 | ||
d419f42d | 215 | while (!feof (file.get ())) |
0568462b MM |
216 | { |
217 | char buffer[1024], symbol[8], *line; | |
218 | uint64_t addr; | |
219 | int match; | |
220 | ||
d419f42d | 221 | line = fgets (buffer, sizeof (buffer), file.get ()); |
0568462b MM |
222 | if (line == NULL) |
223 | break; | |
d68e53f4 | 224 | |
0568462b MM |
225 | match = sscanf (line, "%" SCNx64 " %*[tT] %7s", &addr, symbol); |
226 | if (match != 2) | |
227 | continue; | |
d68e53f4 | 228 | |
0568462b MM |
229 | if (strcmp (symbol, "_text") == 0) |
230 | { | |
231 | kernel_start = addr; | |
232 | break; | |
233 | } | |
234 | } | |
235 | ||
0568462b | 236 | return kernel_start; |
d68e53f4 MM |
237 | } |
238 | ||
7c97f91e MM |
239 | /* Check whether an address is in the kernel. */ |
240 | ||
241 | static inline int | |
0568462b | 242 | perf_event_is_kernel_addr (uint64_t addr) |
7c97f91e | 243 | { |
0568462b | 244 | uint64_t kernel_start; |
7c97f91e | 245 | |
0568462b MM |
246 | kernel_start = linux_determine_kernel_start (); |
247 | if (kernel_start != 0ull) | |
248 | return (addr >= kernel_start); | |
7c97f91e | 249 | |
0568462b MM |
250 | /* If we don't know the kernel's start address, let's check the most |
251 | significant bit. This will work at least for 64-bit kernels. */ | |
252 | return ((addr & (1ull << 63)) != 0); | |
7c97f91e MM |
253 | } |
254 | ||
255 | /* Check whether a perf event record should be skipped. */ | |
256 | ||
257 | static inline int | |
0568462b | 258 | perf_event_skip_bts_record (const struct perf_event_bts *bts) |
7c97f91e MM |
259 | { |
260 | /* The hardware may report branches from kernel into user space. Branches | |
261 | from user into kernel space will be suppressed. We filter the former to | |
262 | provide a consistent branch trace excluding kernel. */ | |
0568462b | 263 | return perf_event_is_kernel_addr (bts->from); |
7c97f91e MM |
264 | } |
265 | ||
266 | /* Perform a few consistency checks on a perf event sample record. This is | |
267 | meant to catch cases when we get out of sync with the perf event stream. */ | |
268 | ||
269 | static inline int | |
270 | perf_event_sample_ok (const struct perf_event_sample *sample) | |
271 | { | |
272 | if (sample->header.type != PERF_RECORD_SAMPLE) | |
273 | return 0; | |
274 | ||
275 | if (sample->header.size != sizeof (*sample)) | |
276 | return 0; | |
277 | ||
278 | return 1; | |
279 | } | |
280 | ||
281 | /* Branch trace is collected in a circular buffer [begin; end) as pairs of from | |
282 | and to addresses (plus a header). | |
283 | ||
284 | Start points into that buffer at the next sample position. | |
285 | We read the collected samples backwards from start. | |
286 | ||
287 | While reading the samples, we convert the information into a list of blocks. | |
288 | For two adjacent samples s1 and s2, we form a block b such that b.begin = | |
289 | s1.to and b.end = s2.from. | |
290 | ||
291 | In case the buffer overflows during sampling, one sample may have its lower | |
292 | part at the end and its upper part at the beginning of the buffer. */ | |
293 | ||
294 | static VEC (btrace_block_s) * | |
295 | perf_event_read_bts (struct btrace_target_info* tinfo, const uint8_t *begin, | |
e7b01ce0 | 296 | const uint8_t *end, const uint8_t *start, size_t size) |
7c97f91e MM |
297 | { |
298 | VEC (btrace_block_s) *btrace = NULL; | |
299 | struct perf_event_sample sample; | |
e7b01ce0 | 300 | size_t read = 0; |
7c97f91e MM |
301 | struct btrace_block block = { 0, 0 }; |
302 | struct regcache *regcache; | |
303 | ||
304 | gdb_assert (begin <= start); | |
305 | gdb_assert (start <= end); | |
306 | ||
307 | /* The first block ends at the current pc. */ | |
361c8ade | 308 | regcache = get_thread_regcache_for_ptid (tinfo->ptid); |
7c97f91e MM |
309 | block.end = regcache_read_pc (regcache); |
310 | ||
311 | /* The buffer may contain a partial record as its last entry (i.e. when the | |
312 | buffer size is not a multiple of the sample size). */ | |
313 | read = sizeof (sample) - 1; | |
314 | ||
315 | for (; read < size; read += sizeof (sample)) | |
316 | { | |
317 | const struct perf_event_sample *psample; | |
318 | ||
319 | /* Find the next perf_event sample in a backwards traversal. */ | |
320 | start -= sizeof (sample); | |
321 | ||
322 | /* If we're still inside the buffer, we're done. */ | |
323 | if (begin <= start) | |
324 | psample = (const struct perf_event_sample *) start; | |
325 | else | |
326 | { | |
327 | int missing; | |
328 | ||
329 | /* We're to the left of the ring buffer, we will wrap around and | |
330 | reappear at the very right of the ring buffer. */ | |
331 | ||
332 | missing = (begin - start); | |
333 | start = (end - missing); | |
334 | ||
335 | /* If the entire sample is missing, we're done. */ | |
336 | if (missing == sizeof (sample)) | |
337 | psample = (const struct perf_event_sample *) start; | |
338 | else | |
339 | { | |
340 | uint8_t *stack; | |
341 | ||
342 | /* The sample wrapped around. The lower part is at the end and | |
343 | the upper part is at the beginning of the buffer. */ | |
344 | stack = (uint8_t *) &sample; | |
345 | ||
346 | /* Copy the two parts so we have a contiguous sample. */ | |
347 | memcpy (stack, start, missing); | |
348 | memcpy (stack + missing, begin, sizeof (sample) - missing); | |
349 | ||
350 | psample = &sample; | |
351 | } | |
352 | } | |
353 | ||
354 | if (!perf_event_sample_ok (psample)) | |
355 | { | |
356 | warning (_("Branch trace may be incomplete.")); | |
357 | break; | |
358 | } | |
359 | ||
0568462b | 360 | if (perf_event_skip_bts_record (&psample->bts)) |
7c97f91e MM |
361 | continue; |
362 | ||
363 | /* We found a valid sample, so we can complete the current block. */ | |
364 | block.begin = psample->bts.to; | |
365 | ||
366 | VEC_safe_push (btrace_block_s, btrace, &block); | |
367 | ||
368 | /* Start the next block. */ | |
369 | block.end = psample->bts.from; | |
370 | } | |
371 | ||
969c39fb MM |
372 | /* Push the last block (i.e. the first one of inferior execution), as well. |
373 | We don't know where it ends, but we know where it starts. If we're | |
374 | reading delta trace, we can fill in the start address later on. | |
375 | Otherwise we will prune it. */ | |
376 | block.begin = 0; | |
377 | VEC_safe_push (btrace_block_s, btrace, &block); | |
378 | ||
7c97f91e MM |
379 | return btrace; |
380 | } | |
381 | ||
043c3577 | 382 | /* Check whether the kernel supports BTS. */ |
a950d57c MM |
383 | |
384 | static int | |
043c3577 | 385 | kernel_supports_bts (void) |
a950d57c MM |
386 | { |
387 | struct perf_event_attr attr; | |
388 | pid_t child, pid; | |
389 | int status, file; | |
390 | ||
391 | errno = 0; | |
392 | child = fork (); | |
393 | switch (child) | |
394 | { | |
395 | case -1: | |
76fb6829 | 396 | warning (_("test bts: cannot fork: %s."), safe_strerror (errno)); |
a950d57c MM |
397 | return 0; |
398 | ||
399 | case 0: | |
400 | status = ptrace (PTRACE_TRACEME, 0, NULL, NULL); | |
401 | if (status != 0) | |
402 | { | |
043c3577 | 403 | warning (_("test bts: cannot PTRACE_TRACEME: %s."), |
76fb6829 | 404 | safe_strerror (errno)); |
a950d57c MM |
405 | _exit (1); |
406 | } | |
407 | ||
408 | status = raise (SIGTRAP); | |
409 | if (status != 0) | |
410 | { | |
043c3577 | 411 | warning (_("test bts: cannot raise SIGTRAP: %s."), |
76fb6829 | 412 | safe_strerror (errno)); |
a950d57c MM |
413 | _exit (1); |
414 | } | |
415 | ||
416 | _exit (1); | |
417 | ||
418 | default: | |
419 | pid = waitpid (child, &status, 0); | |
420 | if (pid != child) | |
421 | { | |
043c3577 | 422 | warning (_("test bts: bad pid %ld, error: %s."), |
76fb6829 | 423 | (long) pid, safe_strerror (errno)); |
a950d57c MM |
424 | return 0; |
425 | } | |
426 | ||
427 | if (!WIFSTOPPED (status)) | |
428 | { | |
043c3577 | 429 | warning (_("test bts: expected stop. status: %d."), |
a950d57c MM |
430 | status); |
431 | return 0; | |
432 | } | |
433 | ||
434 | memset (&attr, 0, sizeof (attr)); | |
435 | ||
436 | attr.type = PERF_TYPE_HARDWARE; | |
437 | attr.config = PERF_COUNT_HW_BRANCH_INSTRUCTIONS; | |
438 | attr.sample_period = 1; | |
439 | attr.sample_type = PERF_SAMPLE_IP | PERF_SAMPLE_ADDR; | |
440 | attr.exclude_kernel = 1; | |
441 | attr.exclude_hv = 1; | |
442 | attr.exclude_idle = 1; | |
443 | ||
444 | file = syscall (SYS_perf_event_open, &attr, child, -1, -1, 0); | |
445 | if (file >= 0) | |
446 | close (file); | |
447 | ||
448 | kill (child, SIGKILL); | |
449 | ptrace (PTRACE_KILL, child, NULL, NULL); | |
450 | ||
451 | pid = waitpid (child, &status, 0); | |
452 | if (pid != child) | |
453 | { | |
043c3577 | 454 | warning (_("test bts: bad pid %ld, error: %s."), |
76fb6829 | 455 | (long) pid, safe_strerror (errno)); |
a950d57c | 456 | if (!WIFSIGNALED (status)) |
043c3577 | 457 | warning (_("test bts: expected killed. status: %d."), |
a950d57c MM |
458 | status); |
459 | } | |
460 | ||
461 | return (file >= 0); | |
462 | } | |
463 | } | |
464 | ||
bc504a31 | 465 | /* Check whether the kernel supports Intel Processor Trace. */ |
b20a6524 MM |
466 | |
467 | static int | |
468 | kernel_supports_pt (void) | |
469 | { | |
470 | struct perf_event_attr attr; | |
471 | pid_t child, pid; | |
472 | int status, file, type; | |
473 | ||
474 | errno = 0; | |
475 | child = fork (); | |
476 | switch (child) | |
477 | { | |
478 | case -1: | |
76fb6829 | 479 | warning (_("test pt: cannot fork: %s."), safe_strerror (errno)); |
b20a6524 MM |
480 | return 0; |
481 | ||
482 | case 0: | |
483 | status = ptrace (PTRACE_TRACEME, 0, NULL, NULL); | |
484 | if (status != 0) | |
485 | { | |
486 | warning (_("test pt: cannot PTRACE_TRACEME: %s."), | |
76fb6829 | 487 | safe_strerror (errno)); |
b20a6524 MM |
488 | _exit (1); |
489 | } | |
490 | ||
491 | status = raise (SIGTRAP); | |
492 | if (status != 0) | |
493 | { | |
494 | warning (_("test pt: cannot raise SIGTRAP: %s."), | |
76fb6829 | 495 | safe_strerror (errno)); |
b20a6524 MM |
496 | _exit (1); |
497 | } | |
498 | ||
499 | _exit (1); | |
500 | ||
501 | default: | |
502 | pid = waitpid (child, &status, 0); | |
503 | if (pid != child) | |
504 | { | |
505 | warning (_("test pt: bad pid %ld, error: %s."), | |
76fb6829 | 506 | (long) pid, safe_strerror (errno)); |
b20a6524 MM |
507 | return 0; |
508 | } | |
509 | ||
510 | if (!WIFSTOPPED (status)) | |
511 | { | |
512 | warning (_("test pt: expected stop. status: %d."), | |
513 | status); | |
514 | return 0; | |
515 | } | |
516 | ||
517 | status = perf_event_pt_event_type (&type); | |
518 | if (status != 0) | |
519 | file = -1; | |
520 | else | |
521 | { | |
522 | memset (&attr, 0, sizeof (attr)); | |
523 | ||
524 | attr.size = sizeof (attr); | |
525 | attr.type = type; | |
526 | attr.exclude_kernel = 1; | |
527 | attr.exclude_hv = 1; | |
528 | attr.exclude_idle = 1; | |
529 | ||
530 | file = syscall (SYS_perf_event_open, &attr, child, -1, -1, 0); | |
531 | if (file >= 0) | |
532 | close (file); | |
533 | } | |
534 | ||
535 | kill (child, SIGKILL); | |
536 | ptrace (PTRACE_KILL, child, NULL, NULL); | |
537 | ||
538 | pid = waitpid (child, &status, 0); | |
539 | if (pid != child) | |
540 | { | |
541 | warning (_("test pt: bad pid %ld, error: %s."), | |
76fb6829 | 542 | (long) pid, safe_strerror (errno)); |
b20a6524 MM |
543 | if (!WIFSIGNALED (status)) |
544 | warning (_("test pt: expected killed. status: %d."), | |
545 | status); | |
546 | } | |
547 | ||
548 | return (file >= 0); | |
549 | } | |
550 | } | |
551 | ||
043c3577 | 552 | /* Check whether an Intel cpu supports BTS. */ |
a950d57c MM |
553 | |
554 | static int | |
afb778a2 | 555 | intel_supports_bts (const struct btrace_cpu *cpu) |
a950d57c | 556 | { |
afb778a2 | 557 | switch (cpu->family) |
5f8e0b8f MF |
558 | { |
559 | case 0x6: | |
afb778a2 | 560 | switch (cpu->model) |
5f8e0b8f MF |
561 | { |
562 | case 0x1a: /* Nehalem */ | |
563 | case 0x1f: | |
564 | case 0x1e: | |
565 | case 0x2e: | |
566 | case 0x25: /* Westmere */ | |
567 | case 0x2c: | |
568 | case 0x2f: | |
569 | case 0x2a: /* Sandy Bridge */ | |
570 | case 0x2d: | |
571 | case 0x3a: /* Ivy Bridge */ | |
572 | ||
573 | /* AAJ122: LBR, BTM, or BTS records may have incorrect branch | |
574 | "from" information afer an EIST transition, T-states, C1E, or | |
575 | Adaptive Thermal Throttling. */ | |
576 | return 0; | |
577 | } | |
578 | } | |
a950d57c MM |
579 | |
580 | return 1; | |
a950d57c MM |
581 | } |
582 | ||
043c3577 | 583 | /* Check whether the cpu supports BTS. */ |
a950d57c MM |
584 | |
585 | static int | |
043c3577 | 586 | cpu_supports_bts (void) |
a950d57c | 587 | { |
afb778a2 | 588 | struct btrace_cpu cpu; |
a950d57c | 589 | |
afb778a2 MM |
590 | cpu = btrace_this_cpu (); |
591 | switch (cpu.vendor) | |
592 | { | |
593 | default: | |
594 | /* Don't know about others. Let's assume they do. */ | |
595 | return 1; | |
a950d57c | 596 | |
afb778a2 MM |
597 | case CV_INTEL: |
598 | return intel_supports_bts (&cpu); | |
599 | } | |
a950d57c MM |
600 | } |
601 | ||
043c3577 | 602 | /* Check whether the linux target supports BTS. */ |
7c97f91e | 603 | |
043c3577 MM |
604 | static int |
605 | linux_supports_bts (void) | |
7c97f91e | 606 | { |
a950d57c MM |
607 | static int cached; |
608 | ||
609 | if (cached == 0) | |
610 | { | |
043c3577 | 611 | if (!kernel_supports_bts ()) |
a950d57c | 612 | cached = -1; |
043c3577 | 613 | else if (!cpu_supports_bts ()) |
a950d57c MM |
614 | cached = -1; |
615 | else | |
616 | cached = 1; | |
617 | } | |
618 | ||
619 | return cached > 0; | |
7c97f91e MM |
620 | } |
621 | ||
bc504a31 | 622 | /* Check whether the linux target supports Intel Processor Trace. */ |
b20a6524 MM |
623 | |
624 | static int | |
625 | linux_supports_pt (void) | |
626 | { | |
627 | static int cached; | |
628 | ||
629 | if (cached == 0) | |
630 | { | |
631 | if (!kernel_supports_pt ()) | |
632 | cached = -1; | |
633 | else | |
634 | cached = 1; | |
635 | } | |
636 | ||
637 | return cached > 0; | |
638 | } | |
639 | ||
7c97f91e MM |
640 | /* See linux-btrace.h. */ |
641 | ||
043c3577 MM |
642 | int |
643 | linux_supports_btrace (struct target_ops *ops, enum btrace_format format) | |
644 | { | |
645 | switch (format) | |
646 | { | |
647 | case BTRACE_FORMAT_NONE: | |
648 | return 0; | |
649 | ||
650 | case BTRACE_FORMAT_BTS: | |
651 | return linux_supports_bts (); | |
b20a6524 MM |
652 | |
653 | case BTRACE_FORMAT_PT: | |
654 | return linux_supports_pt (); | |
043c3577 MM |
655 | } |
656 | ||
657 | internal_error (__FILE__, __LINE__, _("Unknown branch trace format")); | |
658 | } | |
659 | ||
f4abbc16 | 660 | /* Enable branch tracing in BTS format. */ |
043c3577 | 661 | |
f4abbc16 | 662 | static struct btrace_target_info * |
d33501a5 | 663 | linux_enable_bts (ptid_t ptid, const struct btrace_config_bts *conf) |
7c97f91e | 664 | { |
aadf7753 | 665 | struct perf_event_mmap_page *header; |
7c97f91e | 666 | struct btrace_target_info *tinfo; |
f4abbc16 | 667 | struct btrace_tinfo_bts *bts; |
e7b01ce0 MM |
668 | size_t size, pages; |
669 | __u64 data_offset; | |
d0fa7535 | 670 | int pid, pg; |
7c97f91e | 671 | |
8d749320 | 672 | tinfo = XCNEW (struct btrace_target_info); |
7c97f91e MM |
673 | tinfo->ptid = ptid; |
674 | ||
f4abbc16 MM |
675 | tinfo->conf.format = BTRACE_FORMAT_BTS; |
676 | bts = &tinfo->variant.bts; | |
7c97f91e | 677 | |
f4abbc16 MM |
678 | bts->attr.size = sizeof (bts->attr); |
679 | bts->attr.type = PERF_TYPE_HARDWARE; | |
680 | bts->attr.config = PERF_COUNT_HW_BRANCH_INSTRUCTIONS; | |
681 | bts->attr.sample_period = 1; | |
7c97f91e | 682 | |
f4abbc16 MM |
683 | /* We sample from and to address. */ |
684 | bts->attr.sample_type = PERF_SAMPLE_IP | PERF_SAMPLE_ADDR; | |
7c97f91e | 685 | |
f4abbc16 MM |
686 | bts->attr.exclude_kernel = 1; |
687 | bts->attr.exclude_hv = 1; | |
688 | bts->attr.exclude_idle = 1; | |
7c97f91e MM |
689 | |
690 | pid = ptid_get_lwp (ptid); | |
691 | if (pid == 0) | |
692 | pid = ptid_get_pid (ptid); | |
693 | ||
694 | errno = 0; | |
f4abbc16 MM |
695 | bts->file = syscall (SYS_perf_event_open, &bts->attr, pid, -1, -1, 0); |
696 | if (bts->file < 0) | |
b20a6524 | 697 | goto err_out; |
7c97f91e | 698 | |
d33501a5 | 699 | /* Convert the requested size in bytes to pages (rounding up). */ |
e7b01ce0 MM |
700 | pages = ((size_t) conf->size / PAGE_SIZE |
701 | + ((conf->size % PAGE_SIZE) == 0 ? 0 : 1)); | |
d33501a5 MM |
702 | /* We need at least one page. */ |
703 | if (pages == 0) | |
704 | pages = 1; | |
705 | ||
706 | /* The buffer size can be requested in powers of two pages. Adjust PAGES | |
707 | to the next power of two. */ | |
e7b01ce0 MM |
708 | for (pg = 0; pages != ((size_t) 1 << pg); ++pg) |
709 | if ((pages & ((size_t) 1 << pg)) != 0) | |
710 | pages += ((size_t) 1 << pg); | |
d33501a5 MM |
711 | |
712 | /* We try to allocate the requested size. | |
713 | If that fails, try to get as much as we can. */ | |
714 | for (; pages > 0; pages >>= 1) | |
d0fa7535 | 715 | { |
d33501a5 | 716 | size_t length; |
e7b01ce0 | 717 | __u64 data_size; |
d33501a5 | 718 | |
e7b01ce0 MM |
719 | data_size = (__u64) pages * PAGE_SIZE; |
720 | ||
721 | /* Don't ask for more than we can represent in the configuration. */ | |
722 | if ((__u64) UINT_MAX < data_size) | |
723 | continue; | |
724 | ||
725 | size = (size_t) data_size; | |
d33501a5 MM |
726 | length = size + PAGE_SIZE; |
727 | ||
728 | /* Check for overflows. */ | |
e7b01ce0 | 729 | if ((__u64) length != data_size + PAGE_SIZE) |
d33501a5 MM |
730 | continue; |
731 | ||
d0fa7535 | 732 | /* The number of pages we request needs to be a power of two. */ |
224c3ddb SM |
733 | header = ((struct perf_event_mmap_page *) |
734 | mmap (NULL, length, PROT_READ, MAP_SHARED, bts->file, 0)); | |
aadf7753 MM |
735 | if (header != MAP_FAILED) |
736 | break; | |
d0fa7535 | 737 | } |
7c97f91e | 738 | |
010a18a1 | 739 | if (pages == 0) |
aadf7753 MM |
740 | goto err_file; |
741 | ||
010a18a1 | 742 | data_offset = PAGE_SIZE; |
010a18a1 MM |
743 | |
744 | #if defined (PERF_ATTR_SIZE_VER5) | |
745 | if (offsetof (struct perf_event_mmap_page, data_size) <= header->size) | |
746 | { | |
e7b01ce0 MM |
747 | __u64 data_size; |
748 | ||
010a18a1 MM |
749 | data_offset = header->data_offset; |
750 | data_size = header->data_size; | |
e7b01ce0 MM |
751 | |
752 | size = (unsigned int) data_size; | |
753 | ||
754 | /* Check for overflows. */ | |
755 | if ((__u64) size != data_size) | |
756 | { | |
757 | munmap ((void *) header, size + PAGE_SIZE); | |
758 | goto err_file; | |
759 | } | |
010a18a1 MM |
760 | } |
761 | #endif /* defined (PERF_ATTR_SIZE_VER5) */ | |
762 | ||
f4abbc16 | 763 | bts->header = header; |
010a18a1 | 764 | bts->bts.mem = ((const uint8_t *) header) + data_offset; |
e7b01ce0 | 765 | bts->bts.size = size; |
f4abbc16 | 766 | bts->bts.data_head = &header->data_head; |
e7b01ce0 | 767 | bts->bts.last_head = 0ull; |
aadf7753 | 768 | |
e7b01ce0 | 769 | tinfo->conf.bts.size = (unsigned int) size; |
aadf7753 MM |
770 | return tinfo; |
771 | ||
772 | err_file: | |
d0fa7535 | 773 | /* We were not able to allocate any buffer. */ |
f4abbc16 | 774 | close (bts->file); |
7c97f91e | 775 | |
b20a6524 MM |
776 | err_out: |
777 | xfree (tinfo); | |
778 | return NULL; | |
779 | } | |
780 | ||
781 | #if defined (PERF_ATTR_SIZE_VER5) | |
782 | ||
bc504a31 | 783 | /* Enable branch tracing in Intel Processor Trace format. */ |
b20a6524 MM |
784 | |
785 | static struct btrace_target_info * | |
786 | linux_enable_pt (ptid_t ptid, const struct btrace_config_pt *conf) | |
787 | { | |
788 | struct perf_event_mmap_page *header; | |
789 | struct btrace_target_info *tinfo; | |
790 | struct btrace_tinfo_pt *pt; | |
e7b01ce0 | 791 | size_t pages, size; |
b20a6524 MM |
792 | int pid, pg, errcode, type; |
793 | ||
794 | if (conf->size == 0) | |
795 | return NULL; | |
796 | ||
797 | errcode = perf_event_pt_event_type (&type); | |
798 | if (errcode != 0) | |
799 | return NULL; | |
800 | ||
801 | pid = ptid_get_lwp (ptid); | |
802 | if (pid == 0) | |
803 | pid = ptid_get_pid (ptid); | |
804 | ||
8d749320 | 805 | tinfo = XCNEW (struct btrace_target_info); |
b20a6524 | 806 | tinfo->ptid = ptid; |
b20a6524 MM |
807 | |
808 | tinfo->conf.format = BTRACE_FORMAT_PT; | |
809 | pt = &tinfo->variant.pt; | |
810 | ||
811 | pt->attr.size = sizeof (pt->attr); | |
812 | pt->attr.type = type; | |
813 | ||
814 | pt->attr.exclude_kernel = 1; | |
815 | pt->attr.exclude_hv = 1; | |
816 | pt->attr.exclude_idle = 1; | |
817 | ||
818 | errno = 0; | |
819 | pt->file = syscall (SYS_perf_event_open, &pt->attr, pid, -1, -1, 0); | |
820 | if (pt->file < 0) | |
821 | goto err; | |
822 | ||
823 | /* Allocate the configuration page. */ | |
a55515ee SM |
824 | header = ((struct perf_event_mmap_page *) |
825 | mmap (NULL, PAGE_SIZE, PROT_READ | PROT_WRITE, MAP_SHARED, | |
826 | pt->file, 0)); | |
b20a6524 MM |
827 | if (header == MAP_FAILED) |
828 | goto err_file; | |
829 | ||
830 | header->aux_offset = header->data_offset + header->data_size; | |
831 | ||
832 | /* Convert the requested size in bytes to pages (rounding up). */ | |
e7b01ce0 MM |
833 | pages = ((size_t) conf->size / PAGE_SIZE |
834 | + ((conf->size % PAGE_SIZE) == 0 ? 0 : 1)); | |
b20a6524 MM |
835 | /* We need at least one page. */ |
836 | if (pages == 0) | |
837 | pages = 1; | |
838 | ||
839 | /* The buffer size can be requested in powers of two pages. Adjust PAGES | |
840 | to the next power of two. */ | |
e7b01ce0 MM |
841 | for (pg = 0; pages != ((size_t) 1 << pg); ++pg) |
842 | if ((pages & ((size_t) 1 << pg)) != 0) | |
843 | pages += ((size_t) 1 << pg); | |
b20a6524 MM |
844 | |
845 | /* We try to allocate the requested size. | |
846 | If that fails, try to get as much as we can. */ | |
847 | for (; pages > 0; pages >>= 1) | |
848 | { | |
849 | size_t length; | |
e7b01ce0 | 850 | __u64 data_size; |
b20a6524 | 851 | |
e7b01ce0 MM |
852 | data_size = (__u64) pages * PAGE_SIZE; |
853 | ||
854 | /* Don't ask for more than we can represent in the configuration. */ | |
855 | if ((__u64) UINT_MAX < data_size) | |
856 | continue; | |
857 | ||
858 | size = (size_t) data_size; | |
b20a6524 MM |
859 | |
860 | /* Check for overflows. */ | |
e7b01ce0 | 861 | if ((__u64) size != data_size) |
b20a6524 MM |
862 | continue; |
863 | ||
e7b01ce0 MM |
864 | header->aux_size = data_size; |
865 | length = size; | |
b20a6524 | 866 | |
a55515ee SM |
867 | pt->pt.mem = ((const uint8_t *) |
868 | mmap (NULL, length, PROT_READ, MAP_SHARED, pt->file, | |
869 | header->aux_offset)); | |
b20a6524 MM |
870 | if (pt->pt.mem != MAP_FAILED) |
871 | break; | |
872 | } | |
873 | ||
874 | if (pages == 0) | |
875 | goto err_conf; | |
876 | ||
877 | pt->header = header; | |
878 | pt->pt.size = size; | |
879 | pt->pt.data_head = &header->aux_head; | |
880 | ||
e7b01ce0 | 881 | tinfo->conf.pt.size = (unsigned int) size; |
b20a6524 MM |
882 | return tinfo; |
883 | ||
884 | err_conf: | |
885 | munmap((void *) header, PAGE_SIZE); | |
886 | ||
887 | err_file: | |
888 | close (pt->file); | |
889 | ||
7c97f91e MM |
890 | err: |
891 | xfree (tinfo); | |
892 | return NULL; | |
893 | } | |
894 | ||
b20a6524 MM |
895 | #else /* !defined (PERF_ATTR_SIZE_VER5) */ |
896 | ||
897 | static struct btrace_target_info * | |
898 | linux_enable_pt (ptid_t ptid, const struct btrace_config_pt *conf) | |
899 | { | |
900 | errno = EOPNOTSUPP; | |
901 | return NULL; | |
902 | } | |
903 | ||
904 | #endif /* !defined (PERF_ATTR_SIZE_VER5) */ | |
905 | ||
7c97f91e MM |
906 | /* See linux-btrace.h. */ |
907 | ||
f4abbc16 MM |
908 | struct btrace_target_info * |
909 | linux_enable_btrace (ptid_t ptid, const struct btrace_config *conf) | |
910 | { | |
911 | struct btrace_target_info *tinfo; | |
912 | ||
913 | tinfo = NULL; | |
914 | switch (conf->format) | |
915 | { | |
916 | case BTRACE_FORMAT_NONE: | |
917 | break; | |
918 | ||
919 | case BTRACE_FORMAT_BTS: | |
d33501a5 | 920 | tinfo = linux_enable_bts (ptid, &conf->bts); |
f4abbc16 | 921 | break; |
b20a6524 MM |
922 | |
923 | case BTRACE_FORMAT_PT: | |
924 | tinfo = linux_enable_pt (ptid, &conf->pt); | |
925 | break; | |
f4abbc16 MM |
926 | } |
927 | ||
928 | return tinfo; | |
929 | } | |
930 | ||
931 | /* Disable BTS tracing. */ | |
932 | ||
933 | static enum btrace_error | |
934 | linux_disable_bts (struct btrace_tinfo_bts *tinfo) | |
7c97f91e | 935 | { |
aadf7753 | 936 | munmap((void *) tinfo->header, tinfo->bts.size + PAGE_SIZE); |
7c97f91e | 937 | close (tinfo->file); |
7c97f91e | 938 | |
969c39fb | 939 | return BTRACE_ERR_NONE; |
7c97f91e MM |
940 | } |
941 | ||
bc504a31 | 942 | /* Disable Intel Processor Trace tracing. */ |
b20a6524 MM |
943 | |
944 | static enum btrace_error | |
945 | linux_disable_pt (struct btrace_tinfo_pt *tinfo) | |
946 | { | |
947 | munmap((void *) tinfo->pt.mem, tinfo->pt.size); | |
948 | munmap((void *) tinfo->header, PAGE_SIZE); | |
949 | close (tinfo->file); | |
950 | ||
951 | return BTRACE_ERR_NONE; | |
952 | } | |
953 | ||
f4abbc16 MM |
954 | /* See linux-btrace.h. */ |
955 | ||
956 | enum btrace_error | |
957 | linux_disable_btrace (struct btrace_target_info *tinfo) | |
958 | { | |
959 | enum btrace_error errcode; | |
960 | ||
961 | errcode = BTRACE_ERR_NOT_SUPPORTED; | |
962 | switch (tinfo->conf.format) | |
963 | { | |
964 | case BTRACE_FORMAT_NONE: | |
965 | break; | |
966 | ||
967 | case BTRACE_FORMAT_BTS: | |
968 | errcode = linux_disable_bts (&tinfo->variant.bts); | |
969 | break; | |
b20a6524 MM |
970 | |
971 | case BTRACE_FORMAT_PT: | |
972 | errcode = linux_disable_pt (&tinfo->variant.pt); | |
973 | break; | |
f4abbc16 MM |
974 | } |
975 | ||
976 | if (errcode == BTRACE_ERR_NONE) | |
977 | xfree (tinfo); | |
978 | ||
979 | return errcode; | |
980 | } | |
981 | ||
734b0e4b MM |
982 | /* Read branch trace data in BTS format for the thread given by TINFO into |
983 | BTRACE using the TYPE reading method. */ | |
7c97f91e | 984 | |
734b0e4b MM |
985 | static enum btrace_error |
986 | linux_read_bts (struct btrace_data_bts *btrace, | |
987 | struct btrace_target_info *tinfo, | |
988 | enum btrace_read_type type) | |
7c97f91e | 989 | { |
aadf7753 | 990 | struct perf_event_buffer *pevent; |
7c97f91e | 991 | const uint8_t *begin, *end, *start; |
e7b01ce0 MM |
992 | size_t buffer_size, size; |
993 | __u64 data_head, data_tail; | |
aadf7753 MM |
994 | unsigned int retries = 5; |
995 | ||
f4abbc16 | 996 | pevent = &tinfo->variant.bts.bts; |
7c97f91e | 997 | |
969c39fb MM |
998 | /* For delta reads, we return at least the partial last block containing |
999 | the current PC. */ | |
aadf7753 | 1000 | if (type == BTRACE_READ_NEW && !perf_event_new_data (pevent)) |
969c39fb | 1001 | return BTRACE_ERR_NONE; |
7c97f91e | 1002 | |
aadf7753 MM |
1003 | buffer_size = pevent->size; |
1004 | data_tail = pevent->last_head; | |
7c97f91e MM |
1005 | |
1006 | /* We may need to retry reading the trace. See below. */ | |
1007 | while (retries--) | |
1008 | { | |
aadf7753 | 1009 | data_head = *pevent->data_head; |
7c97f91e | 1010 | |
ed9edfb5 | 1011 | /* Delete any leftover trace from the previous iteration. */ |
734b0e4b | 1012 | VEC_free (btrace_block_s, btrace->blocks); |
ed9edfb5 | 1013 | |
969c39fb | 1014 | if (type == BTRACE_READ_DELTA) |
7c97f91e | 1015 | { |
e7b01ce0 MM |
1016 | __u64 data_size; |
1017 | ||
969c39fb MM |
1018 | /* Determine the number of bytes to read and check for buffer |
1019 | overflows. */ | |
1020 | ||
1021 | /* Check for data head overflows. We might be able to recover from | |
1022 | those but they are very unlikely and it's not really worth the | |
1023 | effort, I think. */ | |
1024 | if (data_head < data_tail) | |
1025 | return BTRACE_ERR_OVERFLOW; | |
1026 | ||
1027 | /* If the buffer is smaller than the trace delta, we overflowed. */ | |
e7b01ce0 MM |
1028 | data_size = data_head - data_tail; |
1029 | if (buffer_size < data_size) | |
969c39fb | 1030 | return BTRACE_ERR_OVERFLOW; |
e7b01ce0 MM |
1031 | |
1032 | /* DATA_SIZE <= BUFFER_SIZE and therefore fits into a size_t. */ | |
1033 | size = (size_t) data_size; | |
969c39fb MM |
1034 | } |
1035 | else | |
1036 | { | |
1037 | /* Read the entire buffer. */ | |
1038 | size = buffer_size; | |
7c97f91e | 1039 | |
969c39fb MM |
1040 | /* Adjust the size if the buffer has not overflowed, yet. */ |
1041 | if (data_head < size) | |
e7b01ce0 | 1042 | size = (size_t) data_head; |
7c97f91e MM |
1043 | } |
1044 | ||
969c39fb | 1045 | /* Data_head keeps growing; the buffer itself is circular. */ |
aadf7753 | 1046 | begin = pevent->mem; |
969c39fb MM |
1047 | start = begin + data_head % buffer_size; |
1048 | ||
1049 | if (data_head <= buffer_size) | |
1050 | end = start; | |
1051 | else | |
aadf7753 | 1052 | end = begin + pevent->size; |
969c39fb | 1053 | |
734b0e4b | 1054 | btrace->blocks = perf_event_read_bts (tinfo, begin, end, start, size); |
969c39fb | 1055 | |
7c97f91e MM |
1056 | /* The stopping thread notifies its ptracer before it is scheduled out. |
1057 | On multi-core systems, the debugger might therefore run while the | |
1058 | kernel might be writing the last branch trace records. | |
1059 | ||
1060 | Let's check whether the data head moved while we read the trace. */ | |
aadf7753 | 1061 | if (data_head == *pevent->data_head) |
7c97f91e MM |
1062 | break; |
1063 | } | |
1064 | ||
aadf7753 | 1065 | pevent->last_head = data_head; |
7c97f91e | 1066 | |
969c39fb MM |
1067 | /* Prune the incomplete last block (i.e. the first one of inferior execution) |
1068 | if we're not doing a delta read. There is no way of filling in its zeroed | |
1069 | BEGIN element. */ | |
734b0e4b MM |
1070 | if (!VEC_empty (btrace_block_s, btrace->blocks) |
1071 | && type != BTRACE_READ_DELTA) | |
1072 | VEC_pop (btrace_block_s, btrace->blocks); | |
969c39fb MM |
1073 | |
1074 | return BTRACE_ERR_NONE; | |
7c97f91e MM |
1075 | } |
1076 | ||
bc504a31 | 1077 | /* Fill in the Intel Processor Trace configuration information. */ |
b20a6524 MM |
1078 | |
1079 | static void | |
1080 | linux_fill_btrace_pt_config (struct btrace_data_pt_config *conf) | |
1081 | { | |
1082 | conf->cpu = btrace_this_cpu (); | |
1083 | } | |
1084 | ||
bc504a31 | 1085 | /* Read branch trace data in Intel Processor Trace format for the thread |
b20a6524 MM |
1086 | given by TINFO into BTRACE using the TYPE reading method. */ |
1087 | ||
1088 | static enum btrace_error | |
1089 | linux_read_pt (struct btrace_data_pt *btrace, | |
1090 | struct btrace_target_info *tinfo, | |
1091 | enum btrace_read_type type) | |
1092 | { | |
1093 | struct perf_event_buffer *pt; | |
1094 | ||
1095 | pt = &tinfo->variant.pt.pt; | |
1096 | ||
1097 | linux_fill_btrace_pt_config (&btrace->config); | |
1098 | ||
1099 | switch (type) | |
1100 | { | |
1101 | case BTRACE_READ_DELTA: | |
1102 | /* We don't support delta reads. The data head (i.e. aux_head) wraps | |
1103 | around to stay inside the aux buffer. */ | |
1104 | return BTRACE_ERR_NOT_SUPPORTED; | |
1105 | ||
1106 | case BTRACE_READ_NEW: | |
1107 | if (!perf_event_new_data (pt)) | |
1108 | return BTRACE_ERR_NONE; | |
1109 | ||
1110 | /* Fall through. */ | |
1111 | case BTRACE_READ_ALL: | |
1112 | perf_event_read_all (pt, &btrace->data, &btrace->size); | |
1113 | return BTRACE_ERR_NONE; | |
1114 | } | |
1115 | ||
1116 | internal_error (__FILE__, __LINE__, _("Unkown btrace read type.")); | |
1117 | } | |
1118 | ||
734b0e4b MM |
1119 | /* See linux-btrace.h. */ |
1120 | ||
1121 | enum btrace_error | |
1122 | linux_read_btrace (struct btrace_data *btrace, | |
1123 | struct btrace_target_info *tinfo, | |
1124 | enum btrace_read_type type) | |
1125 | { | |
f4abbc16 MM |
1126 | switch (tinfo->conf.format) |
1127 | { | |
1128 | case BTRACE_FORMAT_NONE: | |
1129 | return BTRACE_ERR_NOT_SUPPORTED; | |
1130 | ||
1131 | case BTRACE_FORMAT_BTS: | |
1132 | /* We read btrace in BTS format. */ | |
1133 | btrace->format = BTRACE_FORMAT_BTS; | |
1134 | btrace->variant.bts.blocks = NULL; | |
1135 | ||
1136 | return linux_read_bts (&btrace->variant.bts, tinfo, type); | |
b20a6524 MM |
1137 | |
1138 | case BTRACE_FORMAT_PT: | |
bc504a31 | 1139 | /* We read btrace in Intel Processor Trace format. */ |
b20a6524 MM |
1140 | btrace->format = BTRACE_FORMAT_PT; |
1141 | btrace->variant.pt.data = NULL; | |
1142 | btrace->variant.pt.size = 0; | |
1143 | ||
1144 | return linux_read_pt (&btrace->variant.pt, tinfo, type); | |
f4abbc16 MM |
1145 | } |
1146 | ||
1147 | internal_error (__FILE__, __LINE__, _("Unkown branch trace format.")); | |
1148 | } | |
1149 | ||
1150 | /* See linux-btrace.h. */ | |
734b0e4b | 1151 | |
f4abbc16 MM |
1152 | const struct btrace_config * |
1153 | linux_btrace_conf (const struct btrace_target_info *tinfo) | |
1154 | { | |
1155 | return &tinfo->conf; | |
734b0e4b MM |
1156 | } |
1157 | ||
7c97f91e MM |
1158 | #else /* !HAVE_LINUX_PERF_EVENT_H */ |
1159 | ||
1160 | /* See linux-btrace.h. */ | |
1161 | ||
1162 | int | |
043c3577 | 1163 | linux_supports_btrace (struct target_ops *ops, enum btrace_format format) |
7c97f91e MM |
1164 | { |
1165 | return 0; | |
1166 | } | |
1167 | ||
1168 | /* See linux-btrace.h. */ | |
1169 | ||
1170 | struct btrace_target_info * | |
f4abbc16 | 1171 | linux_enable_btrace (ptid_t ptid, const struct btrace_config *conf) |
7c97f91e MM |
1172 | { |
1173 | return NULL; | |
1174 | } | |
1175 | ||
1176 | /* See linux-btrace.h. */ | |
1177 | ||
969c39fb | 1178 | enum btrace_error |
7c97f91e MM |
1179 | linux_disable_btrace (struct btrace_target_info *tinfo) |
1180 | { | |
969c39fb | 1181 | return BTRACE_ERR_NOT_SUPPORTED; |
7c97f91e MM |
1182 | } |
1183 | ||
1184 | /* See linux-btrace.h. */ | |
1185 | ||
969c39fb | 1186 | enum btrace_error |
734b0e4b | 1187 | linux_read_btrace (struct btrace_data *btrace, |
969c39fb | 1188 | struct btrace_target_info *tinfo, |
7c97f91e MM |
1189 | enum btrace_read_type type) |
1190 | { | |
969c39fb | 1191 | return BTRACE_ERR_NOT_SUPPORTED; |
7c97f91e MM |
1192 | } |
1193 | ||
f4abbc16 MM |
1194 | /* See linux-btrace.h. */ |
1195 | ||
1196 | const struct btrace_config * | |
1197 | linux_btrace_conf (const struct btrace_target_info *tinfo) | |
1198 | { | |
1199 | return NULL; | |
1200 | } | |
1201 | ||
7c97f91e | 1202 | #endif /* !HAVE_LINUX_PERF_EVENT_H */ |