Commit | Line | Data |
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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 | 27 | #include "filestuff.h" |
5c3284c1 MM |
28 | #include "common/scoped_fd.h" |
29 | #include "common/scoped_mmap.h" | |
0568462b MM |
30 | |
31 | #include <inttypes.h> | |
7c97f91e | 32 | |
5b4e221c | 33 | #include <sys/syscall.h> |
5b4e221c MF |
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 | { | |
5c3284c1 MM |
184 | gdb_file_up file |
185 | = gdb_fopen_cloexec ("/sys/bus/event_source/devices/intel_pt/type", "r"); | |
186 | if (file == nullptr) | |
b20a6524 MM |
187 | return -1; |
188 | ||
5c3284c1 | 189 | int found = fscanf (file.get (), "%d", type); |
b20a6524 MM |
190 | if (found == 1) |
191 | return 0; | |
192 | return -1; | |
193 | } | |
194 | ||
0568462b MM |
195 | /* Try to determine the start address of the Linux kernel. */ |
196 | ||
197 | static uint64_t | |
198 | linux_determine_kernel_start (void) | |
d68e53f4 | 199 | { |
0568462b MM |
200 | static uint64_t kernel_start; |
201 | static int cached; | |
d68e53f4 | 202 | |
0568462b MM |
203 | if (cached != 0) |
204 | return kernel_start; | |
d68e53f4 | 205 | |
0568462b MM |
206 | cached = 1; |
207 | ||
d419f42d | 208 | gdb_file_up file = gdb_fopen_cloexec ("/proc/kallsyms", "r"); |
0568462b MM |
209 | if (file == NULL) |
210 | return kernel_start; | |
211 | ||
d419f42d | 212 | while (!feof (file.get ())) |
0568462b MM |
213 | { |
214 | char buffer[1024], symbol[8], *line; | |
215 | uint64_t addr; | |
216 | int match; | |
217 | ||
d419f42d | 218 | line = fgets (buffer, sizeof (buffer), file.get ()); |
0568462b MM |
219 | if (line == NULL) |
220 | break; | |
d68e53f4 | 221 | |
0568462b MM |
222 | match = sscanf (line, "%" SCNx64 " %*[tT] %7s", &addr, symbol); |
223 | if (match != 2) | |
224 | continue; | |
d68e53f4 | 225 | |
0568462b MM |
226 | if (strcmp (symbol, "_text") == 0) |
227 | { | |
228 | kernel_start = addr; | |
229 | break; | |
230 | } | |
231 | } | |
232 | ||
0568462b | 233 | return kernel_start; |
d68e53f4 MM |
234 | } |
235 | ||
7c97f91e MM |
236 | /* Check whether an address is in the kernel. */ |
237 | ||
238 | static inline int | |
0568462b | 239 | perf_event_is_kernel_addr (uint64_t addr) |
7c97f91e | 240 | { |
0568462b | 241 | uint64_t kernel_start; |
7c97f91e | 242 | |
0568462b MM |
243 | kernel_start = linux_determine_kernel_start (); |
244 | if (kernel_start != 0ull) | |
245 | return (addr >= kernel_start); | |
7c97f91e | 246 | |
0568462b MM |
247 | /* If we don't know the kernel's start address, let's check the most |
248 | significant bit. This will work at least for 64-bit kernels. */ | |
249 | return ((addr & (1ull << 63)) != 0); | |
7c97f91e MM |
250 | } |
251 | ||
252 | /* Check whether a perf event record should be skipped. */ | |
253 | ||
254 | static inline int | |
0568462b | 255 | perf_event_skip_bts_record (const struct perf_event_bts *bts) |
7c97f91e MM |
256 | { |
257 | /* The hardware may report branches from kernel into user space. Branches | |
258 | from user into kernel space will be suppressed. We filter the former to | |
259 | provide a consistent branch trace excluding kernel. */ | |
0568462b | 260 | return perf_event_is_kernel_addr (bts->from); |
7c97f91e MM |
261 | } |
262 | ||
263 | /* Perform a few consistency checks on a perf event sample record. This is | |
264 | meant to catch cases when we get out of sync with the perf event stream. */ | |
265 | ||
266 | static inline int | |
267 | perf_event_sample_ok (const struct perf_event_sample *sample) | |
268 | { | |
269 | if (sample->header.type != PERF_RECORD_SAMPLE) | |
270 | return 0; | |
271 | ||
272 | if (sample->header.size != sizeof (*sample)) | |
273 | return 0; | |
274 | ||
275 | return 1; | |
276 | } | |
277 | ||
278 | /* Branch trace is collected in a circular buffer [begin; end) as pairs of from | |
279 | and to addresses (plus a header). | |
280 | ||
281 | Start points into that buffer at the next sample position. | |
282 | We read the collected samples backwards from start. | |
283 | ||
284 | While reading the samples, we convert the information into a list of blocks. | |
285 | For two adjacent samples s1 and s2, we form a block b such that b.begin = | |
286 | s1.to and b.end = s2.from. | |
287 | ||
288 | In case the buffer overflows during sampling, one sample may have its lower | |
289 | part at the end and its upper part at the beginning of the buffer. */ | |
290 | ||
291 | static VEC (btrace_block_s) * | |
292 | perf_event_read_bts (struct btrace_target_info* tinfo, const uint8_t *begin, | |
e7b01ce0 | 293 | const uint8_t *end, const uint8_t *start, size_t size) |
7c97f91e MM |
294 | { |
295 | VEC (btrace_block_s) *btrace = NULL; | |
296 | struct perf_event_sample sample; | |
e7b01ce0 | 297 | size_t read = 0; |
7c97f91e MM |
298 | struct btrace_block block = { 0, 0 }; |
299 | struct regcache *regcache; | |
300 | ||
301 | gdb_assert (begin <= start); | |
302 | gdb_assert (start <= end); | |
303 | ||
304 | /* The first block ends at the current pc. */ | |
361c8ade | 305 | regcache = get_thread_regcache_for_ptid (tinfo->ptid); |
7c97f91e MM |
306 | block.end = regcache_read_pc (regcache); |
307 | ||
308 | /* The buffer may contain a partial record as its last entry (i.e. when the | |
309 | buffer size is not a multiple of the sample size). */ | |
310 | read = sizeof (sample) - 1; | |
311 | ||
312 | for (; read < size; read += sizeof (sample)) | |
313 | { | |
314 | const struct perf_event_sample *psample; | |
315 | ||
316 | /* Find the next perf_event sample in a backwards traversal. */ | |
317 | start -= sizeof (sample); | |
318 | ||
319 | /* If we're still inside the buffer, we're done. */ | |
320 | if (begin <= start) | |
321 | psample = (const struct perf_event_sample *) start; | |
322 | else | |
323 | { | |
324 | int missing; | |
325 | ||
326 | /* We're to the left of the ring buffer, we will wrap around and | |
327 | reappear at the very right of the ring buffer. */ | |
328 | ||
329 | missing = (begin - start); | |
330 | start = (end - missing); | |
331 | ||
332 | /* If the entire sample is missing, we're done. */ | |
333 | if (missing == sizeof (sample)) | |
334 | psample = (const struct perf_event_sample *) start; | |
335 | else | |
336 | { | |
337 | uint8_t *stack; | |
338 | ||
339 | /* The sample wrapped around. The lower part is at the end and | |
340 | the upper part is at the beginning of the buffer. */ | |
341 | stack = (uint8_t *) &sample; | |
342 | ||
343 | /* Copy the two parts so we have a contiguous sample. */ | |
344 | memcpy (stack, start, missing); | |
345 | memcpy (stack + missing, begin, sizeof (sample) - missing); | |
346 | ||
347 | psample = &sample; | |
348 | } | |
349 | } | |
350 | ||
351 | if (!perf_event_sample_ok (psample)) | |
352 | { | |
353 | warning (_("Branch trace may be incomplete.")); | |
354 | break; | |
355 | } | |
356 | ||
0568462b | 357 | if (perf_event_skip_bts_record (&psample->bts)) |
7c97f91e MM |
358 | continue; |
359 | ||
360 | /* We found a valid sample, so we can complete the current block. */ | |
361 | block.begin = psample->bts.to; | |
362 | ||
363 | VEC_safe_push (btrace_block_s, btrace, &block); | |
364 | ||
365 | /* Start the next block. */ | |
366 | block.end = psample->bts.from; | |
367 | } | |
368 | ||
969c39fb MM |
369 | /* Push the last block (i.e. the first one of inferior execution), as well. |
370 | We don't know where it ends, but we know where it starts. If we're | |
371 | reading delta trace, we can fill in the start address later on. | |
372 | Otherwise we will prune it. */ | |
373 | block.begin = 0; | |
374 | VEC_safe_push (btrace_block_s, btrace, &block); | |
375 | ||
7c97f91e MM |
376 | return btrace; |
377 | } | |
378 | ||
043c3577 | 379 | /* Check whether the kernel supports BTS. */ |
a950d57c MM |
380 | |
381 | static int | |
043c3577 | 382 | kernel_supports_bts (void) |
a950d57c MM |
383 | { |
384 | struct perf_event_attr attr; | |
385 | pid_t child, pid; | |
386 | int status, file; | |
387 | ||
388 | errno = 0; | |
389 | child = fork (); | |
390 | switch (child) | |
391 | { | |
392 | case -1: | |
76fb6829 | 393 | warning (_("test bts: cannot fork: %s."), safe_strerror (errno)); |
a950d57c MM |
394 | return 0; |
395 | ||
396 | case 0: | |
397 | status = ptrace (PTRACE_TRACEME, 0, NULL, NULL); | |
398 | if (status != 0) | |
399 | { | |
043c3577 | 400 | warning (_("test bts: cannot PTRACE_TRACEME: %s."), |
76fb6829 | 401 | safe_strerror (errno)); |
a950d57c MM |
402 | _exit (1); |
403 | } | |
404 | ||
405 | status = raise (SIGTRAP); | |
406 | if (status != 0) | |
407 | { | |
043c3577 | 408 | warning (_("test bts: cannot raise SIGTRAP: %s."), |
76fb6829 | 409 | safe_strerror (errno)); |
a950d57c MM |
410 | _exit (1); |
411 | } | |
412 | ||
413 | _exit (1); | |
414 | ||
415 | default: | |
416 | pid = waitpid (child, &status, 0); | |
417 | if (pid != child) | |
418 | { | |
043c3577 | 419 | warning (_("test bts: bad pid %ld, error: %s."), |
76fb6829 | 420 | (long) pid, safe_strerror (errno)); |
a950d57c MM |
421 | return 0; |
422 | } | |
423 | ||
424 | if (!WIFSTOPPED (status)) | |
425 | { | |
043c3577 | 426 | warning (_("test bts: expected stop. status: %d."), |
a950d57c MM |
427 | status); |
428 | return 0; | |
429 | } | |
430 | ||
431 | memset (&attr, 0, sizeof (attr)); | |
432 | ||
433 | attr.type = PERF_TYPE_HARDWARE; | |
434 | attr.config = PERF_COUNT_HW_BRANCH_INSTRUCTIONS; | |
435 | attr.sample_period = 1; | |
436 | attr.sample_type = PERF_SAMPLE_IP | PERF_SAMPLE_ADDR; | |
437 | attr.exclude_kernel = 1; | |
438 | attr.exclude_hv = 1; | |
439 | attr.exclude_idle = 1; | |
440 | ||
441 | file = syscall (SYS_perf_event_open, &attr, child, -1, -1, 0); | |
442 | if (file >= 0) | |
443 | close (file); | |
444 | ||
445 | kill (child, SIGKILL); | |
446 | ptrace (PTRACE_KILL, child, NULL, NULL); | |
447 | ||
448 | pid = waitpid (child, &status, 0); | |
449 | if (pid != child) | |
450 | { | |
043c3577 | 451 | warning (_("test bts: bad pid %ld, error: %s."), |
76fb6829 | 452 | (long) pid, safe_strerror (errno)); |
a950d57c | 453 | if (!WIFSIGNALED (status)) |
043c3577 | 454 | warning (_("test bts: expected killed. status: %d."), |
a950d57c MM |
455 | status); |
456 | } | |
457 | ||
458 | return (file >= 0); | |
459 | } | |
460 | } | |
461 | ||
bc504a31 | 462 | /* Check whether the kernel supports Intel Processor Trace. */ |
b20a6524 MM |
463 | |
464 | static int | |
465 | kernel_supports_pt (void) | |
466 | { | |
467 | struct perf_event_attr attr; | |
468 | pid_t child, pid; | |
469 | int status, file, type; | |
470 | ||
471 | errno = 0; | |
472 | child = fork (); | |
473 | switch (child) | |
474 | { | |
475 | case -1: | |
76fb6829 | 476 | warning (_("test pt: cannot fork: %s."), safe_strerror (errno)); |
b20a6524 MM |
477 | return 0; |
478 | ||
479 | case 0: | |
480 | status = ptrace (PTRACE_TRACEME, 0, NULL, NULL); | |
481 | if (status != 0) | |
482 | { | |
483 | warning (_("test pt: cannot PTRACE_TRACEME: %s."), | |
76fb6829 | 484 | safe_strerror (errno)); |
b20a6524 MM |
485 | _exit (1); |
486 | } | |
487 | ||
488 | status = raise (SIGTRAP); | |
489 | if (status != 0) | |
490 | { | |
491 | warning (_("test pt: cannot raise SIGTRAP: %s."), | |
76fb6829 | 492 | safe_strerror (errno)); |
b20a6524 MM |
493 | _exit (1); |
494 | } | |
495 | ||
496 | _exit (1); | |
497 | ||
498 | default: | |
499 | pid = waitpid (child, &status, 0); | |
500 | if (pid != child) | |
501 | { | |
502 | warning (_("test pt: bad pid %ld, error: %s."), | |
76fb6829 | 503 | (long) pid, safe_strerror (errno)); |
b20a6524 MM |
504 | return 0; |
505 | } | |
506 | ||
507 | if (!WIFSTOPPED (status)) | |
508 | { | |
509 | warning (_("test pt: expected stop. status: %d."), | |
510 | status); | |
511 | return 0; | |
512 | } | |
513 | ||
514 | status = perf_event_pt_event_type (&type); | |
515 | if (status != 0) | |
516 | file = -1; | |
517 | else | |
518 | { | |
519 | memset (&attr, 0, sizeof (attr)); | |
520 | ||
521 | attr.size = sizeof (attr); | |
522 | attr.type = type; | |
523 | attr.exclude_kernel = 1; | |
524 | attr.exclude_hv = 1; | |
525 | attr.exclude_idle = 1; | |
526 | ||
527 | file = syscall (SYS_perf_event_open, &attr, child, -1, -1, 0); | |
528 | if (file >= 0) | |
529 | close (file); | |
530 | } | |
531 | ||
532 | kill (child, SIGKILL); | |
533 | ptrace (PTRACE_KILL, child, NULL, NULL); | |
534 | ||
535 | pid = waitpid (child, &status, 0); | |
536 | if (pid != child) | |
537 | { | |
538 | warning (_("test pt: bad pid %ld, error: %s."), | |
76fb6829 | 539 | (long) pid, safe_strerror (errno)); |
b20a6524 MM |
540 | if (!WIFSIGNALED (status)) |
541 | warning (_("test pt: expected killed. status: %d."), | |
542 | status); | |
543 | } | |
544 | ||
545 | return (file >= 0); | |
546 | } | |
547 | } | |
548 | ||
043c3577 | 549 | /* Check whether an Intel cpu supports BTS. */ |
a950d57c MM |
550 | |
551 | static int | |
afb778a2 | 552 | intel_supports_bts (const struct btrace_cpu *cpu) |
a950d57c | 553 | { |
afb778a2 | 554 | switch (cpu->family) |
5f8e0b8f MF |
555 | { |
556 | case 0x6: | |
afb778a2 | 557 | switch (cpu->model) |
5f8e0b8f MF |
558 | { |
559 | case 0x1a: /* Nehalem */ | |
560 | case 0x1f: | |
561 | case 0x1e: | |
562 | case 0x2e: | |
563 | case 0x25: /* Westmere */ | |
564 | case 0x2c: | |
565 | case 0x2f: | |
566 | case 0x2a: /* Sandy Bridge */ | |
567 | case 0x2d: | |
568 | case 0x3a: /* Ivy Bridge */ | |
569 | ||
570 | /* AAJ122: LBR, BTM, or BTS records may have incorrect branch | |
571 | "from" information afer an EIST transition, T-states, C1E, or | |
572 | Adaptive Thermal Throttling. */ | |
573 | return 0; | |
574 | } | |
575 | } | |
a950d57c MM |
576 | |
577 | return 1; | |
a950d57c MM |
578 | } |
579 | ||
043c3577 | 580 | /* Check whether the cpu supports BTS. */ |
a950d57c MM |
581 | |
582 | static int | |
043c3577 | 583 | cpu_supports_bts (void) |
a950d57c | 584 | { |
afb778a2 | 585 | struct btrace_cpu cpu; |
a950d57c | 586 | |
afb778a2 MM |
587 | cpu = btrace_this_cpu (); |
588 | switch (cpu.vendor) | |
589 | { | |
590 | default: | |
591 | /* Don't know about others. Let's assume they do. */ | |
592 | return 1; | |
a950d57c | 593 | |
afb778a2 MM |
594 | case CV_INTEL: |
595 | return intel_supports_bts (&cpu); | |
596 | } | |
a950d57c MM |
597 | } |
598 | ||
043c3577 | 599 | /* Check whether the linux target supports BTS. */ |
7c97f91e | 600 | |
043c3577 MM |
601 | static int |
602 | linux_supports_bts (void) | |
7c97f91e | 603 | { |
a950d57c MM |
604 | static int cached; |
605 | ||
606 | if (cached == 0) | |
607 | { | |
043c3577 | 608 | if (!kernel_supports_bts ()) |
a950d57c | 609 | cached = -1; |
043c3577 | 610 | else if (!cpu_supports_bts ()) |
a950d57c MM |
611 | cached = -1; |
612 | else | |
613 | cached = 1; | |
614 | } | |
615 | ||
616 | return cached > 0; | |
7c97f91e MM |
617 | } |
618 | ||
bc504a31 | 619 | /* Check whether the linux target supports Intel Processor Trace. */ |
b20a6524 MM |
620 | |
621 | static int | |
622 | linux_supports_pt (void) | |
623 | { | |
624 | static int cached; | |
625 | ||
626 | if (cached == 0) | |
627 | { | |
628 | if (!kernel_supports_pt ()) | |
629 | cached = -1; | |
630 | else | |
631 | cached = 1; | |
632 | } | |
633 | ||
634 | return cached > 0; | |
635 | } | |
636 | ||
7c97f91e MM |
637 | /* See linux-btrace.h. */ |
638 | ||
043c3577 MM |
639 | int |
640 | linux_supports_btrace (struct target_ops *ops, enum btrace_format format) | |
641 | { | |
642 | switch (format) | |
643 | { | |
644 | case BTRACE_FORMAT_NONE: | |
645 | return 0; | |
646 | ||
647 | case BTRACE_FORMAT_BTS: | |
648 | return linux_supports_bts (); | |
b20a6524 MM |
649 | |
650 | case BTRACE_FORMAT_PT: | |
651 | return linux_supports_pt (); | |
043c3577 MM |
652 | } |
653 | ||
654 | internal_error (__FILE__, __LINE__, _("Unknown branch trace format")); | |
655 | } | |
656 | ||
f4abbc16 | 657 | /* Enable branch tracing in BTS format. */ |
043c3577 | 658 | |
f4abbc16 | 659 | static struct btrace_target_info * |
d33501a5 | 660 | linux_enable_bts (ptid_t ptid, const struct btrace_config_bts *conf) |
7c97f91e | 661 | { |
f4abbc16 | 662 | struct btrace_tinfo_bts *bts; |
e7b01ce0 MM |
663 | size_t size, pages; |
664 | __u64 data_offset; | |
d0fa7535 | 665 | int pid, pg; |
7c97f91e | 666 | |
5c3284c1 MM |
667 | gdb::unique_xmalloc_ptr<btrace_target_info> tinfo |
668 | (XCNEW (btrace_target_info)); | |
7c97f91e MM |
669 | tinfo->ptid = ptid; |
670 | ||
f4abbc16 MM |
671 | tinfo->conf.format = BTRACE_FORMAT_BTS; |
672 | bts = &tinfo->variant.bts; | |
7c97f91e | 673 | |
f4abbc16 MM |
674 | bts->attr.size = sizeof (bts->attr); |
675 | bts->attr.type = PERF_TYPE_HARDWARE; | |
676 | bts->attr.config = PERF_COUNT_HW_BRANCH_INSTRUCTIONS; | |
677 | bts->attr.sample_period = 1; | |
7c97f91e | 678 | |
f4abbc16 MM |
679 | /* We sample from and to address. */ |
680 | bts->attr.sample_type = PERF_SAMPLE_IP | PERF_SAMPLE_ADDR; | |
7c97f91e | 681 | |
f4abbc16 MM |
682 | bts->attr.exclude_kernel = 1; |
683 | bts->attr.exclude_hv = 1; | |
684 | bts->attr.exclude_idle = 1; | |
7c97f91e MM |
685 | |
686 | pid = ptid_get_lwp (ptid); | |
687 | if (pid == 0) | |
688 | pid = ptid_get_pid (ptid); | |
689 | ||
690 | errno = 0; | |
5c3284c1 MM |
691 | scoped_fd fd (syscall (SYS_perf_event_open, &bts->attr, pid, -1, -1, 0)); |
692 | if (fd.get () < 0) | |
693 | return nullptr; | |
7c97f91e | 694 | |
d33501a5 | 695 | /* Convert the requested size in bytes to pages (rounding up). */ |
e7b01ce0 MM |
696 | pages = ((size_t) conf->size / PAGE_SIZE |
697 | + ((conf->size % PAGE_SIZE) == 0 ? 0 : 1)); | |
d33501a5 MM |
698 | /* We need at least one page. */ |
699 | if (pages == 0) | |
700 | pages = 1; | |
701 | ||
702 | /* The buffer size can be requested in powers of two pages. Adjust PAGES | |
703 | to the next power of two. */ | |
e7b01ce0 MM |
704 | for (pg = 0; pages != ((size_t) 1 << pg); ++pg) |
705 | if ((pages & ((size_t) 1 << pg)) != 0) | |
706 | pages += ((size_t) 1 << pg); | |
d33501a5 MM |
707 | |
708 | /* We try to allocate the requested size. | |
709 | If that fails, try to get as much as we can. */ | |
5c3284c1 | 710 | scoped_mmap data; |
d33501a5 | 711 | for (; pages > 0; pages >>= 1) |
d0fa7535 | 712 | { |
d33501a5 | 713 | size_t length; |
e7b01ce0 | 714 | __u64 data_size; |
d33501a5 | 715 | |
e7b01ce0 MM |
716 | data_size = (__u64) pages * PAGE_SIZE; |
717 | ||
718 | /* Don't ask for more than we can represent in the configuration. */ | |
719 | if ((__u64) UINT_MAX < data_size) | |
720 | continue; | |
721 | ||
722 | size = (size_t) data_size; | |
d33501a5 MM |
723 | length = size + PAGE_SIZE; |
724 | ||
725 | /* Check for overflows. */ | |
e7b01ce0 | 726 | if ((__u64) length != data_size + PAGE_SIZE) |
d33501a5 MM |
727 | continue; |
728 | ||
d0fa7535 | 729 | /* The number of pages we request needs to be a power of two. */ |
5c3284c1 MM |
730 | data.reset (nullptr, length, PROT_READ, MAP_SHARED, fd.get (), 0); |
731 | if (data.get () != MAP_FAILED) | |
aadf7753 | 732 | break; |
d0fa7535 | 733 | } |
7c97f91e | 734 | |
010a18a1 | 735 | if (pages == 0) |
5c3284c1 | 736 | return nullptr; |
aadf7753 | 737 | |
5c3284c1 MM |
738 | struct perf_event_mmap_page *header = (struct perf_event_mmap_page *) |
739 | data.get (); | |
010a18a1 | 740 | data_offset = PAGE_SIZE; |
010a18a1 MM |
741 | |
742 | #if defined (PERF_ATTR_SIZE_VER5) | |
743 | if (offsetof (struct perf_event_mmap_page, data_size) <= header->size) | |
744 | { | |
e7b01ce0 MM |
745 | __u64 data_size; |
746 | ||
010a18a1 MM |
747 | data_offset = header->data_offset; |
748 | data_size = header->data_size; | |
e7b01ce0 MM |
749 | |
750 | size = (unsigned int) data_size; | |
751 | ||
752 | /* Check for overflows. */ | |
753 | if ((__u64) size != data_size) | |
5c3284c1 | 754 | return nullptr; |
010a18a1 MM |
755 | } |
756 | #endif /* defined (PERF_ATTR_SIZE_VER5) */ | |
757 | ||
e7b01ce0 | 758 | bts->bts.size = size; |
f4abbc16 | 759 | bts->bts.data_head = &header->data_head; |
5c3284c1 | 760 | bts->bts.mem = (const uint8_t *) data.get () + data_offset; |
e7b01ce0 | 761 | bts->bts.last_head = 0ull; |
5c3284c1 MM |
762 | bts->header = header; |
763 | bts->file = fd.release (); | |
aadf7753 | 764 | |
5c3284c1 | 765 | data.release (); |
7c97f91e | 766 | |
5c3284c1 MM |
767 | tinfo->conf.bts.size = (unsigned int) size; |
768 | return tinfo.release (); | |
b20a6524 MM |
769 | } |
770 | ||
771 | #if defined (PERF_ATTR_SIZE_VER5) | |
772 | ||
bc504a31 | 773 | /* Enable branch tracing in Intel Processor Trace format. */ |
b20a6524 MM |
774 | |
775 | static struct btrace_target_info * | |
776 | linux_enable_pt (ptid_t ptid, const struct btrace_config_pt *conf) | |
777 | { | |
b20a6524 | 778 | struct btrace_tinfo_pt *pt; |
5c3284c1 | 779 | size_t pages; |
b20a6524 MM |
780 | int pid, pg, errcode, type; |
781 | ||
782 | if (conf->size == 0) | |
783 | return NULL; | |
784 | ||
785 | errcode = perf_event_pt_event_type (&type); | |
786 | if (errcode != 0) | |
787 | return NULL; | |
788 | ||
789 | pid = ptid_get_lwp (ptid); | |
790 | if (pid == 0) | |
791 | pid = ptid_get_pid (ptid); | |
792 | ||
5c3284c1 MM |
793 | gdb::unique_xmalloc_ptr<btrace_target_info> tinfo |
794 | (XCNEW (btrace_target_info)); | |
b20a6524 | 795 | tinfo->ptid = ptid; |
b20a6524 MM |
796 | |
797 | tinfo->conf.format = BTRACE_FORMAT_PT; | |
798 | pt = &tinfo->variant.pt; | |
799 | ||
800 | pt->attr.size = sizeof (pt->attr); | |
801 | pt->attr.type = type; | |
802 | ||
803 | pt->attr.exclude_kernel = 1; | |
804 | pt->attr.exclude_hv = 1; | |
805 | pt->attr.exclude_idle = 1; | |
806 | ||
807 | errno = 0; | |
5c3284c1 MM |
808 | scoped_fd fd (syscall (SYS_perf_event_open, &pt->attr, pid, -1, -1, 0)); |
809 | if (fd.get () < 0) | |
810 | return nullptr; | |
b20a6524 MM |
811 | |
812 | /* Allocate the configuration page. */ | |
5c3284c1 MM |
813 | scoped_mmap data (nullptr, PAGE_SIZE, PROT_READ | PROT_WRITE, MAP_SHARED, |
814 | fd.get (), 0); | |
815 | if (data.get () == MAP_FAILED) | |
816 | return nullptr; | |
817 | ||
818 | struct perf_event_mmap_page *header = (struct perf_event_mmap_page *) | |
819 | data.get (); | |
b20a6524 MM |
820 | |
821 | header->aux_offset = header->data_offset + header->data_size; | |
822 | ||
823 | /* Convert the requested size in bytes to pages (rounding up). */ | |
e7b01ce0 MM |
824 | pages = ((size_t) conf->size / PAGE_SIZE |
825 | + ((conf->size % PAGE_SIZE) == 0 ? 0 : 1)); | |
b20a6524 MM |
826 | /* We need at least one page. */ |
827 | if (pages == 0) | |
828 | pages = 1; | |
829 | ||
830 | /* The buffer size can be requested in powers of two pages. Adjust PAGES | |
831 | to the next power of two. */ | |
e7b01ce0 MM |
832 | for (pg = 0; pages != ((size_t) 1 << pg); ++pg) |
833 | if ((pages & ((size_t) 1 << pg)) != 0) | |
834 | pages += ((size_t) 1 << pg); | |
b20a6524 MM |
835 | |
836 | /* We try to allocate the requested size. | |
837 | If that fails, try to get as much as we can. */ | |
5c3284c1 | 838 | scoped_mmap aux; |
b20a6524 MM |
839 | for (; pages > 0; pages >>= 1) |
840 | { | |
841 | size_t length; | |
e7b01ce0 | 842 | __u64 data_size; |
b20a6524 | 843 | |
e7b01ce0 MM |
844 | data_size = (__u64) pages * PAGE_SIZE; |
845 | ||
846 | /* Don't ask for more than we can represent in the configuration. */ | |
847 | if ((__u64) UINT_MAX < data_size) | |
848 | continue; | |
849 | ||
5c3284c1 | 850 | length = (size_t) data_size; |
b20a6524 MM |
851 | |
852 | /* Check for overflows. */ | |
5c3284c1 | 853 | if ((__u64) length != data_size) |
b20a6524 MM |
854 | continue; |
855 | ||
e7b01ce0 | 856 | header->aux_size = data_size; |
b20a6524 | 857 | |
5c3284c1 MM |
858 | aux.reset (nullptr, length, PROT_READ, MAP_SHARED, fd.get (), |
859 | header->aux_offset); | |
860 | if (aux.get () != MAP_FAILED) | |
b20a6524 MM |
861 | break; |
862 | } | |
863 | ||
864 | if (pages == 0) | |
5c3284c1 | 865 | return nullptr; |
b20a6524 | 866 | |
5c3284c1 MM |
867 | pt->pt.size = aux.size (); |
868 | pt->pt.mem = (const uint8_t *) aux.release (); | |
b20a6524 | 869 | pt->pt.data_head = &header->aux_head; |
5c3284c1 MM |
870 | pt->header = header; |
871 | pt->file = fd.release (); | |
b20a6524 | 872 | |
5c3284c1 | 873 | data.release (); |
b20a6524 | 874 | |
5c3284c1 MM |
875 | tinfo->conf.pt.size = (unsigned int) pt->pt.size; |
876 | return tinfo.release (); | |
7c97f91e MM |
877 | } |
878 | ||
b20a6524 MM |
879 | #else /* !defined (PERF_ATTR_SIZE_VER5) */ |
880 | ||
881 | static struct btrace_target_info * | |
882 | linux_enable_pt (ptid_t ptid, const struct btrace_config_pt *conf) | |
883 | { | |
884 | errno = EOPNOTSUPP; | |
885 | return NULL; | |
886 | } | |
887 | ||
888 | #endif /* !defined (PERF_ATTR_SIZE_VER5) */ | |
889 | ||
7c97f91e MM |
890 | /* See linux-btrace.h. */ |
891 | ||
f4abbc16 MM |
892 | struct btrace_target_info * |
893 | linux_enable_btrace (ptid_t ptid, const struct btrace_config *conf) | |
894 | { | |
895 | struct btrace_target_info *tinfo; | |
896 | ||
897 | tinfo = NULL; | |
898 | switch (conf->format) | |
899 | { | |
900 | case BTRACE_FORMAT_NONE: | |
901 | break; | |
902 | ||
903 | case BTRACE_FORMAT_BTS: | |
d33501a5 | 904 | tinfo = linux_enable_bts (ptid, &conf->bts); |
f4abbc16 | 905 | break; |
b20a6524 MM |
906 | |
907 | case BTRACE_FORMAT_PT: | |
908 | tinfo = linux_enable_pt (ptid, &conf->pt); | |
909 | break; | |
f4abbc16 MM |
910 | } |
911 | ||
9ee23a85 MM |
912 | if (tinfo == NULL) |
913 | error (_("Unknown error.")); | |
914 | ||
f4abbc16 MM |
915 | return tinfo; |
916 | } | |
917 | ||
918 | /* Disable BTS tracing. */ | |
919 | ||
920 | static enum btrace_error | |
921 | linux_disable_bts (struct btrace_tinfo_bts *tinfo) | |
7c97f91e | 922 | { |
aadf7753 | 923 | munmap((void *) tinfo->header, tinfo->bts.size + PAGE_SIZE); |
7c97f91e | 924 | close (tinfo->file); |
7c97f91e | 925 | |
969c39fb | 926 | return BTRACE_ERR_NONE; |
7c97f91e MM |
927 | } |
928 | ||
bc504a31 | 929 | /* Disable Intel Processor Trace tracing. */ |
b20a6524 MM |
930 | |
931 | static enum btrace_error | |
932 | linux_disable_pt (struct btrace_tinfo_pt *tinfo) | |
933 | { | |
934 | munmap((void *) tinfo->pt.mem, tinfo->pt.size); | |
935 | munmap((void *) tinfo->header, PAGE_SIZE); | |
936 | close (tinfo->file); | |
937 | ||
938 | return BTRACE_ERR_NONE; | |
939 | } | |
940 | ||
f4abbc16 MM |
941 | /* See linux-btrace.h. */ |
942 | ||
943 | enum btrace_error | |
944 | linux_disable_btrace (struct btrace_target_info *tinfo) | |
945 | { | |
946 | enum btrace_error errcode; | |
947 | ||
948 | errcode = BTRACE_ERR_NOT_SUPPORTED; | |
949 | switch (tinfo->conf.format) | |
950 | { | |
951 | case BTRACE_FORMAT_NONE: | |
952 | break; | |
953 | ||
954 | case BTRACE_FORMAT_BTS: | |
955 | errcode = linux_disable_bts (&tinfo->variant.bts); | |
956 | break; | |
b20a6524 MM |
957 | |
958 | case BTRACE_FORMAT_PT: | |
959 | errcode = linux_disable_pt (&tinfo->variant.pt); | |
960 | break; | |
f4abbc16 MM |
961 | } |
962 | ||
963 | if (errcode == BTRACE_ERR_NONE) | |
964 | xfree (tinfo); | |
965 | ||
966 | return errcode; | |
967 | } | |
968 | ||
734b0e4b MM |
969 | /* Read branch trace data in BTS format for the thread given by TINFO into |
970 | BTRACE using the TYPE reading method. */ | |
7c97f91e | 971 | |
734b0e4b MM |
972 | static enum btrace_error |
973 | linux_read_bts (struct btrace_data_bts *btrace, | |
974 | struct btrace_target_info *tinfo, | |
975 | enum btrace_read_type type) | |
7c97f91e | 976 | { |
aadf7753 | 977 | struct perf_event_buffer *pevent; |
7c97f91e | 978 | const uint8_t *begin, *end, *start; |
e7b01ce0 MM |
979 | size_t buffer_size, size; |
980 | __u64 data_head, data_tail; | |
aadf7753 MM |
981 | unsigned int retries = 5; |
982 | ||
f4abbc16 | 983 | pevent = &tinfo->variant.bts.bts; |
7c97f91e | 984 | |
969c39fb MM |
985 | /* For delta reads, we return at least the partial last block containing |
986 | the current PC. */ | |
aadf7753 | 987 | if (type == BTRACE_READ_NEW && !perf_event_new_data (pevent)) |
969c39fb | 988 | return BTRACE_ERR_NONE; |
7c97f91e | 989 | |
aadf7753 MM |
990 | buffer_size = pevent->size; |
991 | data_tail = pevent->last_head; | |
7c97f91e MM |
992 | |
993 | /* We may need to retry reading the trace. See below. */ | |
994 | while (retries--) | |
995 | { | |
aadf7753 | 996 | data_head = *pevent->data_head; |
7c97f91e | 997 | |
ed9edfb5 | 998 | /* Delete any leftover trace from the previous iteration. */ |
734b0e4b | 999 | VEC_free (btrace_block_s, btrace->blocks); |
ed9edfb5 | 1000 | |
969c39fb | 1001 | if (type == BTRACE_READ_DELTA) |
7c97f91e | 1002 | { |
e7b01ce0 MM |
1003 | __u64 data_size; |
1004 | ||
969c39fb MM |
1005 | /* Determine the number of bytes to read and check for buffer |
1006 | overflows. */ | |
1007 | ||
1008 | /* Check for data head overflows. We might be able to recover from | |
1009 | those but they are very unlikely and it's not really worth the | |
1010 | effort, I think. */ | |
1011 | if (data_head < data_tail) | |
1012 | return BTRACE_ERR_OVERFLOW; | |
1013 | ||
1014 | /* If the buffer is smaller than the trace delta, we overflowed. */ | |
e7b01ce0 MM |
1015 | data_size = data_head - data_tail; |
1016 | if (buffer_size < data_size) | |
969c39fb | 1017 | return BTRACE_ERR_OVERFLOW; |
e7b01ce0 MM |
1018 | |
1019 | /* DATA_SIZE <= BUFFER_SIZE and therefore fits into a size_t. */ | |
1020 | size = (size_t) data_size; | |
969c39fb MM |
1021 | } |
1022 | else | |
1023 | { | |
1024 | /* Read the entire buffer. */ | |
1025 | size = buffer_size; | |
7c97f91e | 1026 | |
969c39fb MM |
1027 | /* Adjust the size if the buffer has not overflowed, yet. */ |
1028 | if (data_head < size) | |
e7b01ce0 | 1029 | size = (size_t) data_head; |
7c97f91e MM |
1030 | } |
1031 | ||
969c39fb | 1032 | /* Data_head keeps growing; the buffer itself is circular. */ |
aadf7753 | 1033 | begin = pevent->mem; |
969c39fb MM |
1034 | start = begin + data_head % buffer_size; |
1035 | ||
1036 | if (data_head <= buffer_size) | |
1037 | end = start; | |
1038 | else | |
aadf7753 | 1039 | end = begin + pevent->size; |
969c39fb | 1040 | |
734b0e4b | 1041 | btrace->blocks = perf_event_read_bts (tinfo, begin, end, start, size); |
969c39fb | 1042 | |
7c97f91e MM |
1043 | /* The stopping thread notifies its ptracer before it is scheduled out. |
1044 | On multi-core systems, the debugger might therefore run while the | |
1045 | kernel might be writing the last branch trace records. | |
1046 | ||
1047 | Let's check whether the data head moved while we read the trace. */ | |
aadf7753 | 1048 | if (data_head == *pevent->data_head) |
7c97f91e MM |
1049 | break; |
1050 | } | |
1051 | ||
aadf7753 | 1052 | pevent->last_head = data_head; |
7c97f91e | 1053 | |
969c39fb MM |
1054 | /* Prune the incomplete last block (i.e. the first one of inferior execution) |
1055 | if we're not doing a delta read. There is no way of filling in its zeroed | |
1056 | BEGIN element. */ | |
734b0e4b MM |
1057 | if (!VEC_empty (btrace_block_s, btrace->blocks) |
1058 | && type != BTRACE_READ_DELTA) | |
1059 | VEC_pop (btrace_block_s, btrace->blocks); | |
969c39fb MM |
1060 | |
1061 | return BTRACE_ERR_NONE; | |
7c97f91e MM |
1062 | } |
1063 | ||
bc504a31 | 1064 | /* Fill in the Intel Processor Trace configuration information. */ |
b20a6524 MM |
1065 | |
1066 | static void | |
1067 | linux_fill_btrace_pt_config (struct btrace_data_pt_config *conf) | |
1068 | { | |
1069 | conf->cpu = btrace_this_cpu (); | |
1070 | } | |
1071 | ||
bc504a31 | 1072 | /* Read branch trace data in Intel Processor Trace format for the thread |
b20a6524 MM |
1073 | given by TINFO into BTRACE using the TYPE reading method. */ |
1074 | ||
1075 | static enum btrace_error | |
1076 | linux_read_pt (struct btrace_data_pt *btrace, | |
1077 | struct btrace_target_info *tinfo, | |
1078 | enum btrace_read_type type) | |
1079 | { | |
1080 | struct perf_event_buffer *pt; | |
1081 | ||
1082 | pt = &tinfo->variant.pt.pt; | |
1083 | ||
1084 | linux_fill_btrace_pt_config (&btrace->config); | |
1085 | ||
1086 | switch (type) | |
1087 | { | |
1088 | case BTRACE_READ_DELTA: | |
1089 | /* We don't support delta reads. The data head (i.e. aux_head) wraps | |
1090 | around to stay inside the aux buffer. */ | |
1091 | return BTRACE_ERR_NOT_SUPPORTED; | |
1092 | ||
1093 | case BTRACE_READ_NEW: | |
1094 | if (!perf_event_new_data (pt)) | |
1095 | return BTRACE_ERR_NONE; | |
1096 | ||
1097 | /* Fall through. */ | |
1098 | case BTRACE_READ_ALL: | |
1099 | perf_event_read_all (pt, &btrace->data, &btrace->size); | |
1100 | return BTRACE_ERR_NONE; | |
1101 | } | |
1102 | ||
1103 | internal_error (__FILE__, __LINE__, _("Unkown btrace read type.")); | |
1104 | } | |
1105 | ||
734b0e4b MM |
1106 | /* See linux-btrace.h. */ |
1107 | ||
1108 | enum btrace_error | |
1109 | linux_read_btrace (struct btrace_data *btrace, | |
1110 | struct btrace_target_info *tinfo, | |
1111 | enum btrace_read_type type) | |
1112 | { | |
f4abbc16 MM |
1113 | switch (tinfo->conf.format) |
1114 | { | |
1115 | case BTRACE_FORMAT_NONE: | |
1116 | return BTRACE_ERR_NOT_SUPPORTED; | |
1117 | ||
1118 | case BTRACE_FORMAT_BTS: | |
1119 | /* We read btrace in BTS format. */ | |
1120 | btrace->format = BTRACE_FORMAT_BTS; | |
1121 | btrace->variant.bts.blocks = NULL; | |
1122 | ||
1123 | return linux_read_bts (&btrace->variant.bts, tinfo, type); | |
b20a6524 MM |
1124 | |
1125 | case BTRACE_FORMAT_PT: | |
bc504a31 | 1126 | /* We read btrace in Intel Processor Trace format. */ |
b20a6524 MM |
1127 | btrace->format = BTRACE_FORMAT_PT; |
1128 | btrace->variant.pt.data = NULL; | |
1129 | btrace->variant.pt.size = 0; | |
1130 | ||
1131 | return linux_read_pt (&btrace->variant.pt, tinfo, type); | |
f4abbc16 MM |
1132 | } |
1133 | ||
1134 | internal_error (__FILE__, __LINE__, _("Unkown branch trace format.")); | |
1135 | } | |
1136 | ||
1137 | /* See linux-btrace.h. */ | |
734b0e4b | 1138 | |
f4abbc16 MM |
1139 | const struct btrace_config * |
1140 | linux_btrace_conf (const struct btrace_target_info *tinfo) | |
1141 | { | |
1142 | return &tinfo->conf; | |
734b0e4b MM |
1143 | } |
1144 | ||
7c97f91e MM |
1145 | #else /* !HAVE_LINUX_PERF_EVENT_H */ |
1146 | ||
1147 | /* See linux-btrace.h. */ | |
1148 | ||
1149 | int | |
043c3577 | 1150 | linux_supports_btrace (struct target_ops *ops, enum btrace_format format) |
7c97f91e MM |
1151 | { |
1152 | return 0; | |
1153 | } | |
1154 | ||
1155 | /* See linux-btrace.h. */ | |
1156 | ||
1157 | struct btrace_target_info * | |
f4abbc16 | 1158 | linux_enable_btrace (ptid_t ptid, const struct btrace_config *conf) |
7c97f91e MM |
1159 | { |
1160 | return NULL; | |
1161 | } | |
1162 | ||
1163 | /* See linux-btrace.h. */ | |
1164 | ||
969c39fb | 1165 | enum btrace_error |
7c97f91e MM |
1166 | linux_disable_btrace (struct btrace_target_info *tinfo) |
1167 | { | |
969c39fb | 1168 | return BTRACE_ERR_NOT_SUPPORTED; |
7c97f91e MM |
1169 | } |
1170 | ||
1171 | /* See linux-btrace.h. */ | |
1172 | ||
969c39fb | 1173 | enum btrace_error |
734b0e4b | 1174 | linux_read_btrace (struct btrace_data *btrace, |
969c39fb | 1175 | struct btrace_target_info *tinfo, |
7c97f91e MM |
1176 | enum btrace_read_type type) |
1177 | { | |
969c39fb | 1178 | return BTRACE_ERR_NOT_SUPPORTED; |
7c97f91e MM |
1179 | } |
1180 | ||
f4abbc16 MM |
1181 | /* See linux-btrace.h. */ |
1182 | ||
1183 | const struct btrace_config * | |
1184 | linux_btrace_conf (const struct btrace_target_info *tinfo) | |
1185 | { | |
1186 | return NULL; | |
1187 | } | |
1188 | ||
7c97f91e | 1189 | #endif /* !HAVE_LINUX_PERF_EVENT_H */ |