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7c97f91e MM |
1 | /* Linux-dependent part of branch trace support for GDB, and GDBserver. |
2 | ||
32d0add0 | 3 | Copyright (C) 2013-2015 Free Software Foundation, Inc. |
7c97f91e MM |
4 | |
5 | Contributed by Intel Corp. <markus.t.metzger@intel.com> | |
6 | ||
7 | This file is part of GDB. | |
8 | ||
9 | This program is free software; you can redistribute it and/or modify | |
10 | it under the terms of the GNU General Public License as published by | |
11 | the Free Software Foundation; either version 3 of the License, or | |
12 | (at your option) any later version. | |
13 | ||
14 | This program is distributed in the hope that it will be useful, | |
15 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
16 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
17 | GNU General Public License for more details. | |
18 | ||
19 | You should have received a copy of the GNU General Public License | |
20 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ | |
21 | ||
53f81362 | 22 | #include "common-defs.h" |
7c97f91e | 23 | #include "linux-btrace.h" |
361c8ade | 24 | #include "common-regcache.h" |
be8b1ea6 | 25 | #include "gdb_wait.h" |
df7e5265 | 26 | #include "x86-cpuid.h" |
7c97f91e | 27 | |
5b4e221c MF |
28 | #ifdef HAVE_SYS_SYSCALL_H |
29 | #include <sys/syscall.h> | |
30 | #endif | |
31 | ||
32 | #if HAVE_LINUX_PERF_EVENT_H && defined(SYS_perf_event_open) | |
7c97f91e | 33 | #include <unistd.h> |
7c97f91e MM |
34 | #include <sys/mman.h> |
35 | #include <sys/user.h> | |
5826e159 | 36 | #include "nat/gdb_ptrace.h" |
a950d57c | 37 | #include <sys/types.h> |
a950d57c | 38 | #include <signal.h> |
d68e53f4 | 39 | #include <sys/utsname.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 | ||
d68e53f4 MM |
104 | /* Try to determine the size of a pointer in bits for the OS. |
105 | ||
106 | This is the same as the size of a pointer for the inferior process | |
107 | except when a 32-bit inferior is running on a 64-bit OS. */ | |
108 | ||
b20a6524 MM |
109 | /* Copy the last SIZE bytes from PEV ending at DATA_HEAD and return a pointer |
110 | to the memory holding the copy. | |
111 | The caller is responsible for freeing the memory. */ | |
112 | ||
113 | static gdb_byte * | |
e7b01ce0 MM |
114 | perf_event_read (const struct perf_event_buffer *pev, __u64 data_head, |
115 | size_t size) | |
b20a6524 MM |
116 | { |
117 | const gdb_byte *begin, *end, *start, *stop; | |
118 | gdb_byte *buffer; | |
e7b01ce0 MM |
119 | size_t buffer_size; |
120 | __u64 data_tail; | |
b20a6524 MM |
121 | |
122 | if (size == 0) | |
123 | return NULL; | |
124 | ||
125 | gdb_assert (size <= data_head); | |
126 | data_tail = data_head - size; | |
127 | ||
128 | buffer_size = pev->size; | |
129 | begin = pev->mem; | |
130 | start = begin + data_tail % buffer_size; | |
131 | stop = begin + data_head % buffer_size; | |
132 | ||
133 | buffer = xmalloc (size); | |
134 | ||
135 | if (start < stop) | |
136 | memcpy (buffer, start, stop - start); | |
137 | else | |
138 | { | |
139 | end = begin + buffer_size; | |
140 | ||
141 | memcpy (buffer, start, end - start); | |
142 | memcpy (buffer + (end - start), begin, stop - begin); | |
143 | } | |
144 | ||
145 | return buffer; | |
146 | } | |
147 | ||
148 | /* Copy the perf event buffer data from PEV. | |
149 | Store a pointer to the copy into DATA and its size in SIZE. */ | |
150 | ||
151 | static void | |
152 | perf_event_read_all (struct perf_event_buffer *pev, gdb_byte **data, | |
e7b01ce0 | 153 | size_t *psize) |
b20a6524 | 154 | { |
e7b01ce0 MM |
155 | size_t size; |
156 | __u64 data_head; | |
b20a6524 MM |
157 | |
158 | data_head = *pev->data_head; | |
159 | ||
160 | size = pev->size; | |
161 | if (data_head < size) | |
e7b01ce0 | 162 | size = (size_t) data_head; |
b20a6524 MM |
163 | |
164 | *data = perf_event_read (pev, data_head, size); | |
165 | *psize = size; | |
166 | ||
167 | pev->last_head = data_head; | |
168 | } | |
169 | ||
170 | /* Determine the event type. | |
171 | Returns zero on success and fills in TYPE; returns -1 otherwise. */ | |
172 | ||
173 | static int | |
174 | perf_event_pt_event_type (int *type) | |
175 | { | |
176 | FILE *file; | |
177 | int found; | |
178 | ||
179 | file = fopen ("/sys/bus/event_source/devices/intel_pt/type", "r"); | |
180 | if (file == NULL) | |
181 | return -1; | |
182 | ||
183 | found = fscanf (file, "%d", type); | |
184 | ||
185 | fclose (file); | |
186 | ||
187 | if (found == 1) | |
188 | return 0; | |
189 | return -1; | |
190 | } | |
191 | ||
d68e53f4 MM |
192 | static int |
193 | linux_determine_kernel_ptr_bits (void) | |
194 | { | |
195 | struct utsname utsn; | |
196 | int errcode; | |
197 | ||
198 | memset (&utsn, 0, sizeof (utsn)); | |
199 | ||
200 | errcode = uname (&utsn); | |
201 | if (errcode < 0) | |
202 | return 0; | |
203 | ||
204 | /* We only need to handle the 64-bit host case, here. For 32-bit host, | |
205 | the pointer size can be filled in later based on the inferior. */ | |
206 | if (strcmp (utsn.machine, "x86_64") == 0) | |
207 | return 64; | |
208 | ||
209 | return 0; | |
210 | } | |
211 | ||
7c97f91e MM |
212 | /* Check whether an address is in the kernel. */ |
213 | ||
214 | static inline int | |
215 | perf_event_is_kernel_addr (const struct btrace_target_info *tinfo, | |
216 | uint64_t addr) | |
217 | { | |
218 | uint64_t mask; | |
219 | ||
220 | /* If we don't know the size of a pointer, we can't check. Let's assume it's | |
221 | not a kernel address in this case. */ | |
222 | if (tinfo->ptr_bits == 0) | |
223 | return 0; | |
224 | ||
225 | /* A bit mask for the most significant bit in an address. */ | |
226 | mask = (uint64_t) 1 << (tinfo->ptr_bits - 1); | |
227 | ||
228 | /* Check whether the most significant bit in the address is set. */ | |
229 | return (addr & mask) != 0; | |
230 | } | |
231 | ||
232 | /* Check whether a perf event record should be skipped. */ | |
233 | ||
234 | static inline int | |
f4abbc16 MM |
235 | perf_event_skip_bts_record (const struct btrace_target_info *tinfo, |
236 | const struct perf_event_bts *bts) | |
7c97f91e MM |
237 | { |
238 | /* The hardware may report branches from kernel into user space. Branches | |
239 | from user into kernel space will be suppressed. We filter the former to | |
240 | provide a consistent branch trace excluding kernel. */ | |
241 | return perf_event_is_kernel_addr (tinfo, bts->from); | |
242 | } | |
243 | ||
244 | /* Perform a few consistency checks on a perf event sample record. This is | |
245 | meant to catch cases when we get out of sync with the perf event stream. */ | |
246 | ||
247 | static inline int | |
248 | perf_event_sample_ok (const struct perf_event_sample *sample) | |
249 | { | |
250 | if (sample->header.type != PERF_RECORD_SAMPLE) | |
251 | return 0; | |
252 | ||
253 | if (sample->header.size != sizeof (*sample)) | |
254 | return 0; | |
255 | ||
256 | return 1; | |
257 | } | |
258 | ||
259 | /* Branch trace is collected in a circular buffer [begin; end) as pairs of from | |
260 | and to addresses (plus a header). | |
261 | ||
262 | Start points into that buffer at the next sample position. | |
263 | We read the collected samples backwards from start. | |
264 | ||
265 | While reading the samples, we convert the information into a list of blocks. | |
266 | For two adjacent samples s1 and s2, we form a block b such that b.begin = | |
267 | s1.to and b.end = s2.from. | |
268 | ||
269 | In case the buffer overflows during sampling, one sample may have its lower | |
270 | part at the end and its upper part at the beginning of the buffer. */ | |
271 | ||
272 | static VEC (btrace_block_s) * | |
273 | perf_event_read_bts (struct btrace_target_info* tinfo, const uint8_t *begin, | |
e7b01ce0 | 274 | const uint8_t *end, const uint8_t *start, size_t size) |
7c97f91e MM |
275 | { |
276 | VEC (btrace_block_s) *btrace = NULL; | |
277 | struct perf_event_sample sample; | |
e7b01ce0 | 278 | size_t read = 0; |
7c97f91e MM |
279 | struct btrace_block block = { 0, 0 }; |
280 | struct regcache *regcache; | |
281 | ||
282 | gdb_assert (begin <= start); | |
283 | gdb_assert (start <= end); | |
284 | ||
285 | /* The first block ends at the current pc. */ | |
361c8ade | 286 | regcache = get_thread_regcache_for_ptid (tinfo->ptid); |
7c97f91e MM |
287 | block.end = regcache_read_pc (regcache); |
288 | ||
289 | /* The buffer may contain a partial record as its last entry (i.e. when the | |
290 | buffer size is not a multiple of the sample size). */ | |
291 | read = sizeof (sample) - 1; | |
292 | ||
293 | for (; read < size; read += sizeof (sample)) | |
294 | { | |
295 | const struct perf_event_sample *psample; | |
296 | ||
297 | /* Find the next perf_event sample in a backwards traversal. */ | |
298 | start -= sizeof (sample); | |
299 | ||
300 | /* If we're still inside the buffer, we're done. */ | |
301 | if (begin <= start) | |
302 | psample = (const struct perf_event_sample *) start; | |
303 | else | |
304 | { | |
305 | int missing; | |
306 | ||
307 | /* We're to the left of the ring buffer, we will wrap around and | |
308 | reappear at the very right of the ring buffer. */ | |
309 | ||
310 | missing = (begin - start); | |
311 | start = (end - missing); | |
312 | ||
313 | /* If the entire sample is missing, we're done. */ | |
314 | if (missing == sizeof (sample)) | |
315 | psample = (const struct perf_event_sample *) start; | |
316 | else | |
317 | { | |
318 | uint8_t *stack; | |
319 | ||
320 | /* The sample wrapped around. The lower part is at the end and | |
321 | the upper part is at the beginning of the buffer. */ | |
322 | stack = (uint8_t *) &sample; | |
323 | ||
324 | /* Copy the two parts so we have a contiguous sample. */ | |
325 | memcpy (stack, start, missing); | |
326 | memcpy (stack + missing, begin, sizeof (sample) - missing); | |
327 | ||
328 | psample = &sample; | |
329 | } | |
330 | } | |
331 | ||
332 | if (!perf_event_sample_ok (psample)) | |
333 | { | |
334 | warning (_("Branch trace may be incomplete.")); | |
335 | break; | |
336 | } | |
337 | ||
f4abbc16 | 338 | if (perf_event_skip_bts_record (tinfo, &psample->bts)) |
7c97f91e MM |
339 | continue; |
340 | ||
341 | /* We found a valid sample, so we can complete the current block. */ | |
342 | block.begin = psample->bts.to; | |
343 | ||
344 | VEC_safe_push (btrace_block_s, btrace, &block); | |
345 | ||
346 | /* Start the next block. */ | |
347 | block.end = psample->bts.from; | |
348 | } | |
349 | ||
969c39fb MM |
350 | /* Push the last block (i.e. the first one of inferior execution), as well. |
351 | We don't know where it ends, but we know where it starts. If we're | |
352 | reading delta trace, we can fill in the start address later on. | |
353 | Otherwise we will prune it. */ | |
354 | block.begin = 0; | |
355 | VEC_safe_push (btrace_block_s, btrace, &block); | |
356 | ||
7c97f91e MM |
357 | return btrace; |
358 | } | |
359 | ||
043c3577 | 360 | /* Check whether the kernel supports BTS. */ |
a950d57c MM |
361 | |
362 | static int | |
043c3577 | 363 | kernel_supports_bts (void) |
a950d57c MM |
364 | { |
365 | struct perf_event_attr attr; | |
366 | pid_t child, pid; | |
367 | int status, file; | |
368 | ||
369 | errno = 0; | |
370 | child = fork (); | |
371 | switch (child) | |
372 | { | |
373 | case -1: | |
76fb6829 | 374 | warning (_("test bts: cannot fork: %s."), safe_strerror (errno)); |
a950d57c MM |
375 | return 0; |
376 | ||
377 | case 0: | |
378 | status = ptrace (PTRACE_TRACEME, 0, NULL, NULL); | |
379 | if (status != 0) | |
380 | { | |
043c3577 | 381 | warning (_("test bts: cannot PTRACE_TRACEME: %s."), |
76fb6829 | 382 | safe_strerror (errno)); |
a950d57c MM |
383 | _exit (1); |
384 | } | |
385 | ||
386 | status = raise (SIGTRAP); | |
387 | if (status != 0) | |
388 | { | |
043c3577 | 389 | warning (_("test bts: cannot raise SIGTRAP: %s."), |
76fb6829 | 390 | safe_strerror (errno)); |
a950d57c MM |
391 | _exit (1); |
392 | } | |
393 | ||
394 | _exit (1); | |
395 | ||
396 | default: | |
397 | pid = waitpid (child, &status, 0); | |
398 | if (pid != child) | |
399 | { | |
043c3577 | 400 | warning (_("test bts: bad pid %ld, error: %s."), |
76fb6829 | 401 | (long) pid, safe_strerror (errno)); |
a950d57c MM |
402 | return 0; |
403 | } | |
404 | ||
405 | if (!WIFSTOPPED (status)) | |
406 | { | |
043c3577 | 407 | warning (_("test bts: expected stop. status: %d."), |
a950d57c MM |
408 | status); |
409 | return 0; | |
410 | } | |
411 | ||
412 | memset (&attr, 0, sizeof (attr)); | |
413 | ||
414 | attr.type = PERF_TYPE_HARDWARE; | |
415 | attr.config = PERF_COUNT_HW_BRANCH_INSTRUCTIONS; | |
416 | attr.sample_period = 1; | |
417 | attr.sample_type = PERF_SAMPLE_IP | PERF_SAMPLE_ADDR; | |
418 | attr.exclude_kernel = 1; | |
419 | attr.exclude_hv = 1; | |
420 | attr.exclude_idle = 1; | |
421 | ||
422 | file = syscall (SYS_perf_event_open, &attr, child, -1, -1, 0); | |
423 | if (file >= 0) | |
424 | close (file); | |
425 | ||
426 | kill (child, SIGKILL); | |
427 | ptrace (PTRACE_KILL, child, NULL, NULL); | |
428 | ||
429 | pid = waitpid (child, &status, 0); | |
430 | if (pid != child) | |
431 | { | |
043c3577 | 432 | warning (_("test bts: bad pid %ld, error: %s."), |
76fb6829 | 433 | (long) pid, safe_strerror (errno)); |
a950d57c | 434 | if (!WIFSIGNALED (status)) |
043c3577 | 435 | warning (_("test bts: expected killed. status: %d."), |
a950d57c MM |
436 | status); |
437 | } | |
438 | ||
439 | return (file >= 0); | |
440 | } | |
441 | } | |
442 | ||
b20a6524 MM |
443 | /* Check whether the kernel supports Intel(R) Processor Trace. */ |
444 | ||
445 | static int | |
446 | kernel_supports_pt (void) | |
447 | { | |
448 | struct perf_event_attr attr; | |
449 | pid_t child, pid; | |
450 | int status, file, type; | |
451 | ||
452 | errno = 0; | |
453 | child = fork (); | |
454 | switch (child) | |
455 | { | |
456 | case -1: | |
76fb6829 | 457 | warning (_("test pt: cannot fork: %s."), safe_strerror (errno)); |
b20a6524 MM |
458 | return 0; |
459 | ||
460 | case 0: | |
461 | status = ptrace (PTRACE_TRACEME, 0, NULL, NULL); | |
462 | if (status != 0) | |
463 | { | |
464 | warning (_("test pt: cannot PTRACE_TRACEME: %s."), | |
76fb6829 | 465 | safe_strerror (errno)); |
b20a6524 MM |
466 | _exit (1); |
467 | } | |
468 | ||
469 | status = raise (SIGTRAP); | |
470 | if (status != 0) | |
471 | { | |
472 | warning (_("test pt: cannot raise SIGTRAP: %s."), | |
76fb6829 | 473 | safe_strerror (errno)); |
b20a6524 MM |
474 | _exit (1); |
475 | } | |
476 | ||
477 | _exit (1); | |
478 | ||
479 | default: | |
480 | pid = waitpid (child, &status, 0); | |
481 | if (pid != child) | |
482 | { | |
483 | warning (_("test pt: bad pid %ld, error: %s."), | |
76fb6829 | 484 | (long) pid, safe_strerror (errno)); |
b20a6524 MM |
485 | return 0; |
486 | } | |
487 | ||
488 | if (!WIFSTOPPED (status)) | |
489 | { | |
490 | warning (_("test pt: expected stop. status: %d."), | |
491 | status); | |
492 | return 0; | |
493 | } | |
494 | ||
495 | status = perf_event_pt_event_type (&type); | |
496 | if (status != 0) | |
497 | file = -1; | |
498 | else | |
499 | { | |
500 | memset (&attr, 0, sizeof (attr)); | |
501 | ||
502 | attr.size = sizeof (attr); | |
503 | attr.type = type; | |
504 | attr.exclude_kernel = 1; | |
505 | attr.exclude_hv = 1; | |
506 | attr.exclude_idle = 1; | |
507 | ||
508 | file = syscall (SYS_perf_event_open, &attr, child, -1, -1, 0); | |
509 | if (file >= 0) | |
510 | close (file); | |
511 | } | |
512 | ||
513 | kill (child, SIGKILL); | |
514 | ptrace (PTRACE_KILL, child, NULL, NULL); | |
515 | ||
516 | pid = waitpid (child, &status, 0); | |
517 | if (pid != child) | |
518 | { | |
519 | warning (_("test pt: bad pid %ld, error: %s."), | |
76fb6829 | 520 | (long) pid, safe_strerror (errno)); |
b20a6524 MM |
521 | if (!WIFSIGNALED (status)) |
522 | warning (_("test pt: expected killed. status: %d."), | |
523 | status); | |
524 | } | |
525 | ||
526 | return (file >= 0); | |
527 | } | |
528 | } | |
529 | ||
043c3577 | 530 | /* Check whether an Intel cpu supports BTS. */ |
a950d57c MM |
531 | |
532 | static int | |
afb778a2 | 533 | intel_supports_bts (const struct btrace_cpu *cpu) |
a950d57c | 534 | { |
afb778a2 | 535 | switch (cpu->family) |
5f8e0b8f MF |
536 | { |
537 | case 0x6: | |
afb778a2 | 538 | switch (cpu->model) |
5f8e0b8f MF |
539 | { |
540 | case 0x1a: /* Nehalem */ | |
541 | case 0x1f: | |
542 | case 0x1e: | |
543 | case 0x2e: | |
544 | case 0x25: /* Westmere */ | |
545 | case 0x2c: | |
546 | case 0x2f: | |
547 | case 0x2a: /* Sandy Bridge */ | |
548 | case 0x2d: | |
549 | case 0x3a: /* Ivy Bridge */ | |
550 | ||
551 | /* AAJ122: LBR, BTM, or BTS records may have incorrect branch | |
552 | "from" information afer an EIST transition, T-states, C1E, or | |
553 | Adaptive Thermal Throttling. */ | |
554 | return 0; | |
555 | } | |
556 | } | |
a950d57c MM |
557 | |
558 | return 1; | |
a950d57c MM |
559 | } |
560 | ||
043c3577 | 561 | /* Check whether the cpu supports BTS. */ |
a950d57c MM |
562 | |
563 | static int | |
043c3577 | 564 | cpu_supports_bts (void) |
a950d57c | 565 | { |
afb778a2 | 566 | struct btrace_cpu cpu; |
a950d57c | 567 | |
afb778a2 MM |
568 | cpu = btrace_this_cpu (); |
569 | switch (cpu.vendor) | |
570 | { | |
571 | default: | |
572 | /* Don't know about others. Let's assume they do. */ | |
573 | return 1; | |
a950d57c | 574 | |
afb778a2 MM |
575 | case CV_INTEL: |
576 | return intel_supports_bts (&cpu); | |
577 | } | |
a950d57c MM |
578 | } |
579 | ||
043c3577 | 580 | /* Check whether the linux target supports BTS. */ |
7c97f91e | 581 | |
043c3577 MM |
582 | static int |
583 | linux_supports_bts (void) | |
7c97f91e | 584 | { |
a950d57c MM |
585 | static int cached; |
586 | ||
587 | if (cached == 0) | |
588 | { | |
043c3577 | 589 | if (!kernel_supports_bts ()) |
a950d57c | 590 | cached = -1; |
043c3577 | 591 | else if (!cpu_supports_bts ()) |
a950d57c MM |
592 | cached = -1; |
593 | else | |
594 | cached = 1; | |
595 | } | |
596 | ||
597 | return cached > 0; | |
7c97f91e MM |
598 | } |
599 | ||
b20a6524 MM |
600 | /* Check whether the linux target supports Intel(R) Processor Trace. */ |
601 | ||
602 | static int | |
603 | linux_supports_pt (void) | |
604 | { | |
605 | static int cached; | |
606 | ||
607 | if (cached == 0) | |
608 | { | |
609 | if (!kernel_supports_pt ()) | |
610 | cached = -1; | |
611 | else | |
612 | cached = 1; | |
613 | } | |
614 | ||
615 | return cached > 0; | |
616 | } | |
617 | ||
7c97f91e MM |
618 | /* See linux-btrace.h. */ |
619 | ||
043c3577 MM |
620 | int |
621 | linux_supports_btrace (struct target_ops *ops, enum btrace_format format) | |
622 | { | |
623 | switch (format) | |
624 | { | |
625 | case BTRACE_FORMAT_NONE: | |
626 | return 0; | |
627 | ||
628 | case BTRACE_FORMAT_BTS: | |
629 | return linux_supports_bts (); | |
b20a6524 MM |
630 | |
631 | case BTRACE_FORMAT_PT: | |
632 | return linux_supports_pt (); | |
043c3577 MM |
633 | } |
634 | ||
635 | internal_error (__FILE__, __LINE__, _("Unknown branch trace format")); | |
636 | } | |
637 | ||
f4abbc16 | 638 | /* Enable branch tracing in BTS format. */ |
043c3577 | 639 | |
f4abbc16 | 640 | static struct btrace_target_info * |
d33501a5 | 641 | linux_enable_bts (ptid_t ptid, const struct btrace_config_bts *conf) |
7c97f91e | 642 | { |
aadf7753 | 643 | struct perf_event_mmap_page *header; |
7c97f91e | 644 | struct btrace_target_info *tinfo; |
f4abbc16 | 645 | struct btrace_tinfo_bts *bts; |
e7b01ce0 MM |
646 | size_t size, pages; |
647 | __u64 data_offset; | |
d0fa7535 | 648 | int pid, pg; |
7c97f91e MM |
649 | |
650 | tinfo = xzalloc (sizeof (*tinfo)); | |
651 | tinfo->ptid = ptid; | |
d68e53f4 | 652 | tinfo->ptr_bits = linux_determine_kernel_ptr_bits (); |
7c97f91e | 653 | |
f4abbc16 MM |
654 | tinfo->conf.format = BTRACE_FORMAT_BTS; |
655 | bts = &tinfo->variant.bts; | |
7c97f91e | 656 | |
f4abbc16 MM |
657 | bts->attr.size = sizeof (bts->attr); |
658 | bts->attr.type = PERF_TYPE_HARDWARE; | |
659 | bts->attr.config = PERF_COUNT_HW_BRANCH_INSTRUCTIONS; | |
660 | bts->attr.sample_period = 1; | |
7c97f91e | 661 | |
f4abbc16 MM |
662 | /* We sample from and to address. */ |
663 | bts->attr.sample_type = PERF_SAMPLE_IP | PERF_SAMPLE_ADDR; | |
7c97f91e | 664 | |
f4abbc16 MM |
665 | bts->attr.exclude_kernel = 1; |
666 | bts->attr.exclude_hv = 1; | |
667 | bts->attr.exclude_idle = 1; | |
7c97f91e MM |
668 | |
669 | pid = ptid_get_lwp (ptid); | |
670 | if (pid == 0) | |
671 | pid = ptid_get_pid (ptid); | |
672 | ||
673 | errno = 0; | |
f4abbc16 MM |
674 | bts->file = syscall (SYS_perf_event_open, &bts->attr, pid, -1, -1, 0); |
675 | if (bts->file < 0) | |
b20a6524 | 676 | goto err_out; |
7c97f91e | 677 | |
d33501a5 | 678 | /* Convert the requested size in bytes to pages (rounding up). */ |
e7b01ce0 MM |
679 | pages = ((size_t) conf->size / PAGE_SIZE |
680 | + ((conf->size % PAGE_SIZE) == 0 ? 0 : 1)); | |
d33501a5 MM |
681 | /* We need at least one page. */ |
682 | if (pages == 0) | |
683 | pages = 1; | |
684 | ||
685 | /* The buffer size can be requested in powers of two pages. Adjust PAGES | |
686 | to the next power of two. */ | |
e7b01ce0 MM |
687 | for (pg = 0; pages != ((size_t) 1 << pg); ++pg) |
688 | if ((pages & ((size_t) 1 << pg)) != 0) | |
689 | pages += ((size_t) 1 << pg); | |
d33501a5 MM |
690 | |
691 | /* We try to allocate the requested size. | |
692 | If that fails, try to get as much as we can. */ | |
693 | for (; pages > 0; pages >>= 1) | |
d0fa7535 | 694 | { |
d33501a5 | 695 | size_t length; |
e7b01ce0 | 696 | __u64 data_size; |
d33501a5 | 697 | |
e7b01ce0 MM |
698 | data_size = (__u64) pages * PAGE_SIZE; |
699 | ||
700 | /* Don't ask for more than we can represent in the configuration. */ | |
701 | if ((__u64) UINT_MAX < data_size) | |
702 | continue; | |
703 | ||
704 | size = (size_t) data_size; | |
d33501a5 MM |
705 | length = size + PAGE_SIZE; |
706 | ||
707 | /* Check for overflows. */ | |
e7b01ce0 | 708 | if ((__u64) length != data_size + PAGE_SIZE) |
d33501a5 MM |
709 | continue; |
710 | ||
d0fa7535 | 711 | /* The number of pages we request needs to be a power of two. */ |
d33501a5 | 712 | header = mmap (NULL, length, PROT_READ, MAP_SHARED, bts->file, 0); |
aadf7753 MM |
713 | if (header != MAP_FAILED) |
714 | break; | |
d0fa7535 | 715 | } |
7c97f91e | 716 | |
010a18a1 | 717 | if (pages == 0) |
aadf7753 MM |
718 | goto err_file; |
719 | ||
010a18a1 | 720 | data_offset = PAGE_SIZE; |
010a18a1 MM |
721 | |
722 | #if defined (PERF_ATTR_SIZE_VER5) | |
723 | if (offsetof (struct perf_event_mmap_page, data_size) <= header->size) | |
724 | { | |
e7b01ce0 MM |
725 | __u64 data_size; |
726 | ||
010a18a1 MM |
727 | data_offset = header->data_offset; |
728 | data_size = header->data_size; | |
e7b01ce0 MM |
729 | |
730 | size = (unsigned int) data_size; | |
731 | ||
732 | /* Check for overflows. */ | |
733 | if ((__u64) size != data_size) | |
734 | { | |
735 | munmap ((void *) header, size + PAGE_SIZE); | |
736 | goto err_file; | |
737 | } | |
010a18a1 MM |
738 | } |
739 | #endif /* defined (PERF_ATTR_SIZE_VER5) */ | |
740 | ||
f4abbc16 | 741 | bts->header = header; |
010a18a1 | 742 | bts->bts.mem = ((const uint8_t *) header) + data_offset; |
e7b01ce0 | 743 | bts->bts.size = size; |
f4abbc16 | 744 | bts->bts.data_head = &header->data_head; |
e7b01ce0 | 745 | bts->bts.last_head = 0ull; |
aadf7753 | 746 | |
e7b01ce0 | 747 | tinfo->conf.bts.size = (unsigned int) size; |
aadf7753 MM |
748 | return tinfo; |
749 | ||
750 | err_file: | |
d0fa7535 | 751 | /* We were not able to allocate any buffer. */ |
f4abbc16 | 752 | close (bts->file); |
7c97f91e | 753 | |
b20a6524 MM |
754 | err_out: |
755 | xfree (tinfo); | |
756 | return NULL; | |
757 | } | |
758 | ||
759 | #if defined (PERF_ATTR_SIZE_VER5) | |
760 | ||
761 | /* Enable branch tracing in Intel(R) Processor Trace format. */ | |
762 | ||
763 | static struct btrace_target_info * | |
764 | linux_enable_pt (ptid_t ptid, const struct btrace_config_pt *conf) | |
765 | { | |
766 | struct perf_event_mmap_page *header; | |
767 | struct btrace_target_info *tinfo; | |
768 | struct btrace_tinfo_pt *pt; | |
e7b01ce0 | 769 | size_t pages, size; |
b20a6524 MM |
770 | int pid, pg, errcode, type; |
771 | ||
772 | if (conf->size == 0) | |
773 | return NULL; | |
774 | ||
775 | errcode = perf_event_pt_event_type (&type); | |
776 | if (errcode != 0) | |
777 | return NULL; | |
778 | ||
779 | pid = ptid_get_lwp (ptid); | |
780 | if (pid == 0) | |
781 | pid = ptid_get_pid (ptid); | |
782 | ||
783 | tinfo = xzalloc (sizeof (*tinfo)); | |
784 | tinfo->ptid = ptid; | |
785 | tinfo->ptr_bits = 0; | |
786 | ||
787 | tinfo->conf.format = BTRACE_FORMAT_PT; | |
788 | pt = &tinfo->variant.pt; | |
789 | ||
790 | pt->attr.size = sizeof (pt->attr); | |
791 | pt->attr.type = type; | |
792 | ||
793 | pt->attr.exclude_kernel = 1; | |
794 | pt->attr.exclude_hv = 1; | |
795 | pt->attr.exclude_idle = 1; | |
796 | ||
797 | errno = 0; | |
798 | pt->file = syscall (SYS_perf_event_open, &pt->attr, pid, -1, -1, 0); | |
799 | if (pt->file < 0) | |
800 | goto err; | |
801 | ||
802 | /* Allocate the configuration page. */ | |
803 | header = mmap (NULL, PAGE_SIZE, PROT_READ | PROT_WRITE, MAP_SHARED, | |
804 | pt->file, 0); | |
805 | if (header == MAP_FAILED) | |
806 | goto err_file; | |
807 | ||
808 | header->aux_offset = header->data_offset + header->data_size; | |
809 | ||
810 | /* Convert the requested size in bytes to pages (rounding up). */ | |
e7b01ce0 MM |
811 | pages = ((size_t) conf->size / PAGE_SIZE |
812 | + ((conf->size % PAGE_SIZE) == 0 ? 0 : 1)); | |
b20a6524 MM |
813 | /* We need at least one page. */ |
814 | if (pages == 0) | |
815 | pages = 1; | |
816 | ||
817 | /* The buffer size can be requested in powers of two pages. Adjust PAGES | |
818 | to the next power of two. */ | |
e7b01ce0 MM |
819 | for (pg = 0; pages != ((size_t) 1 << pg); ++pg) |
820 | if ((pages & ((size_t) 1 << pg)) != 0) | |
821 | pages += ((size_t) 1 << pg); | |
b20a6524 MM |
822 | |
823 | /* We try to allocate the requested size. | |
824 | If that fails, try to get as much as we can. */ | |
825 | for (; pages > 0; pages >>= 1) | |
826 | { | |
827 | size_t length; | |
e7b01ce0 | 828 | __u64 data_size; |
b20a6524 | 829 | |
e7b01ce0 MM |
830 | data_size = (__u64) pages * PAGE_SIZE; |
831 | ||
832 | /* Don't ask for more than we can represent in the configuration. */ | |
833 | if ((__u64) UINT_MAX < data_size) | |
834 | continue; | |
835 | ||
836 | size = (size_t) data_size; | |
b20a6524 MM |
837 | |
838 | /* Check for overflows. */ | |
e7b01ce0 | 839 | if ((__u64) size != data_size) |
b20a6524 MM |
840 | continue; |
841 | ||
e7b01ce0 MM |
842 | header->aux_size = data_size; |
843 | length = size; | |
b20a6524 MM |
844 | |
845 | pt->pt.mem = mmap (NULL, length, PROT_READ, MAP_SHARED, pt->file, | |
846 | header->aux_offset); | |
847 | if (pt->pt.mem != MAP_FAILED) | |
848 | break; | |
849 | } | |
850 | ||
851 | if (pages == 0) | |
852 | goto err_conf; | |
853 | ||
854 | pt->header = header; | |
855 | pt->pt.size = size; | |
856 | pt->pt.data_head = &header->aux_head; | |
857 | ||
e7b01ce0 | 858 | tinfo->conf.pt.size = (unsigned int) size; |
b20a6524 MM |
859 | return tinfo; |
860 | ||
861 | err_conf: | |
862 | munmap((void *) header, PAGE_SIZE); | |
863 | ||
864 | err_file: | |
865 | close (pt->file); | |
866 | ||
7c97f91e MM |
867 | err: |
868 | xfree (tinfo); | |
869 | return NULL; | |
870 | } | |
871 | ||
b20a6524 MM |
872 | #else /* !defined (PERF_ATTR_SIZE_VER5) */ |
873 | ||
874 | static struct btrace_target_info * | |
875 | linux_enable_pt (ptid_t ptid, const struct btrace_config_pt *conf) | |
876 | { | |
877 | errno = EOPNOTSUPP; | |
878 | return NULL; | |
879 | } | |
880 | ||
881 | #endif /* !defined (PERF_ATTR_SIZE_VER5) */ | |
882 | ||
7c97f91e MM |
883 | /* See linux-btrace.h. */ |
884 | ||
f4abbc16 MM |
885 | struct btrace_target_info * |
886 | linux_enable_btrace (ptid_t ptid, const struct btrace_config *conf) | |
887 | { | |
888 | struct btrace_target_info *tinfo; | |
889 | ||
890 | tinfo = NULL; | |
891 | switch (conf->format) | |
892 | { | |
893 | case BTRACE_FORMAT_NONE: | |
894 | break; | |
895 | ||
896 | case BTRACE_FORMAT_BTS: | |
d33501a5 | 897 | tinfo = linux_enable_bts (ptid, &conf->bts); |
f4abbc16 | 898 | break; |
b20a6524 MM |
899 | |
900 | case BTRACE_FORMAT_PT: | |
901 | tinfo = linux_enable_pt (ptid, &conf->pt); | |
902 | break; | |
f4abbc16 MM |
903 | } |
904 | ||
905 | return tinfo; | |
906 | } | |
907 | ||
908 | /* Disable BTS tracing. */ | |
909 | ||
910 | static enum btrace_error | |
911 | linux_disable_bts (struct btrace_tinfo_bts *tinfo) | |
7c97f91e | 912 | { |
aadf7753 | 913 | munmap((void *) tinfo->header, tinfo->bts.size + PAGE_SIZE); |
7c97f91e | 914 | close (tinfo->file); |
7c97f91e | 915 | |
969c39fb | 916 | return BTRACE_ERR_NONE; |
7c97f91e MM |
917 | } |
918 | ||
b20a6524 MM |
919 | /* Disable Intel(R) Processor Trace tracing. */ |
920 | ||
921 | static enum btrace_error | |
922 | linux_disable_pt (struct btrace_tinfo_pt *tinfo) | |
923 | { | |
924 | munmap((void *) tinfo->pt.mem, tinfo->pt.size); | |
925 | munmap((void *) tinfo->header, PAGE_SIZE); | |
926 | close (tinfo->file); | |
927 | ||
928 | return BTRACE_ERR_NONE; | |
929 | } | |
930 | ||
f4abbc16 MM |
931 | /* See linux-btrace.h. */ |
932 | ||
933 | enum btrace_error | |
934 | linux_disable_btrace (struct btrace_target_info *tinfo) | |
935 | { | |
936 | enum btrace_error errcode; | |
937 | ||
938 | errcode = BTRACE_ERR_NOT_SUPPORTED; | |
939 | switch (tinfo->conf.format) | |
940 | { | |
941 | case BTRACE_FORMAT_NONE: | |
942 | break; | |
943 | ||
944 | case BTRACE_FORMAT_BTS: | |
945 | errcode = linux_disable_bts (&tinfo->variant.bts); | |
946 | break; | |
b20a6524 MM |
947 | |
948 | case BTRACE_FORMAT_PT: | |
949 | errcode = linux_disable_pt (&tinfo->variant.pt); | |
950 | break; | |
f4abbc16 MM |
951 | } |
952 | ||
953 | if (errcode == BTRACE_ERR_NONE) | |
954 | xfree (tinfo); | |
955 | ||
956 | return errcode; | |
957 | } | |
958 | ||
734b0e4b MM |
959 | /* Read branch trace data in BTS format for the thread given by TINFO into |
960 | BTRACE using the TYPE reading method. */ | |
7c97f91e | 961 | |
734b0e4b MM |
962 | static enum btrace_error |
963 | linux_read_bts (struct btrace_data_bts *btrace, | |
964 | struct btrace_target_info *tinfo, | |
965 | enum btrace_read_type type) | |
7c97f91e | 966 | { |
aadf7753 | 967 | struct perf_event_buffer *pevent; |
7c97f91e | 968 | const uint8_t *begin, *end, *start; |
e7b01ce0 MM |
969 | size_t buffer_size, size; |
970 | __u64 data_head, data_tail; | |
aadf7753 MM |
971 | unsigned int retries = 5; |
972 | ||
f4abbc16 | 973 | pevent = &tinfo->variant.bts.bts; |
7c97f91e | 974 | |
969c39fb MM |
975 | /* For delta reads, we return at least the partial last block containing |
976 | the current PC. */ | |
aadf7753 | 977 | if (type == BTRACE_READ_NEW && !perf_event_new_data (pevent)) |
969c39fb | 978 | return BTRACE_ERR_NONE; |
7c97f91e | 979 | |
aadf7753 MM |
980 | buffer_size = pevent->size; |
981 | data_tail = pevent->last_head; | |
7c97f91e MM |
982 | |
983 | /* We may need to retry reading the trace. See below. */ | |
984 | while (retries--) | |
985 | { | |
aadf7753 | 986 | data_head = *pevent->data_head; |
7c97f91e | 987 | |
ed9edfb5 | 988 | /* Delete any leftover trace from the previous iteration. */ |
734b0e4b | 989 | VEC_free (btrace_block_s, btrace->blocks); |
ed9edfb5 | 990 | |
969c39fb | 991 | if (type == BTRACE_READ_DELTA) |
7c97f91e | 992 | { |
e7b01ce0 MM |
993 | __u64 data_size; |
994 | ||
969c39fb MM |
995 | /* Determine the number of bytes to read and check for buffer |
996 | overflows. */ | |
997 | ||
998 | /* Check for data head overflows. We might be able to recover from | |
999 | those but they are very unlikely and it's not really worth the | |
1000 | effort, I think. */ | |
1001 | if (data_head < data_tail) | |
1002 | return BTRACE_ERR_OVERFLOW; | |
1003 | ||
1004 | /* If the buffer is smaller than the trace delta, we overflowed. */ | |
e7b01ce0 MM |
1005 | data_size = data_head - data_tail; |
1006 | if (buffer_size < data_size) | |
969c39fb | 1007 | return BTRACE_ERR_OVERFLOW; |
e7b01ce0 MM |
1008 | |
1009 | /* DATA_SIZE <= BUFFER_SIZE and therefore fits into a size_t. */ | |
1010 | size = (size_t) data_size; | |
969c39fb MM |
1011 | } |
1012 | else | |
1013 | { | |
1014 | /* Read the entire buffer. */ | |
1015 | size = buffer_size; | |
7c97f91e | 1016 | |
969c39fb MM |
1017 | /* Adjust the size if the buffer has not overflowed, yet. */ |
1018 | if (data_head < size) | |
e7b01ce0 | 1019 | size = (size_t) data_head; |
7c97f91e MM |
1020 | } |
1021 | ||
969c39fb | 1022 | /* Data_head keeps growing; the buffer itself is circular. */ |
aadf7753 | 1023 | begin = pevent->mem; |
969c39fb MM |
1024 | start = begin + data_head % buffer_size; |
1025 | ||
1026 | if (data_head <= buffer_size) | |
1027 | end = start; | |
1028 | else | |
aadf7753 | 1029 | end = begin + pevent->size; |
969c39fb | 1030 | |
734b0e4b | 1031 | btrace->blocks = perf_event_read_bts (tinfo, begin, end, start, size); |
969c39fb | 1032 | |
7c97f91e MM |
1033 | /* The stopping thread notifies its ptracer before it is scheduled out. |
1034 | On multi-core systems, the debugger might therefore run while the | |
1035 | kernel might be writing the last branch trace records. | |
1036 | ||
1037 | Let's check whether the data head moved while we read the trace. */ | |
aadf7753 | 1038 | if (data_head == *pevent->data_head) |
7c97f91e MM |
1039 | break; |
1040 | } | |
1041 | ||
aadf7753 | 1042 | pevent->last_head = data_head; |
7c97f91e | 1043 | |
969c39fb MM |
1044 | /* Prune the incomplete last block (i.e. the first one of inferior execution) |
1045 | if we're not doing a delta read. There is no way of filling in its zeroed | |
1046 | BEGIN element. */ | |
734b0e4b MM |
1047 | if (!VEC_empty (btrace_block_s, btrace->blocks) |
1048 | && type != BTRACE_READ_DELTA) | |
1049 | VEC_pop (btrace_block_s, btrace->blocks); | |
969c39fb MM |
1050 | |
1051 | return BTRACE_ERR_NONE; | |
7c97f91e MM |
1052 | } |
1053 | ||
b20a6524 MM |
1054 | /* Fill in the Intel(R) Processor Trace configuration information. */ |
1055 | ||
1056 | static void | |
1057 | linux_fill_btrace_pt_config (struct btrace_data_pt_config *conf) | |
1058 | { | |
1059 | conf->cpu = btrace_this_cpu (); | |
1060 | } | |
1061 | ||
1062 | /* Read branch trace data in Intel(R) Processor Trace format for the thread | |
1063 | given by TINFO into BTRACE using the TYPE reading method. */ | |
1064 | ||
1065 | static enum btrace_error | |
1066 | linux_read_pt (struct btrace_data_pt *btrace, | |
1067 | struct btrace_target_info *tinfo, | |
1068 | enum btrace_read_type type) | |
1069 | { | |
1070 | struct perf_event_buffer *pt; | |
1071 | ||
1072 | pt = &tinfo->variant.pt.pt; | |
1073 | ||
1074 | linux_fill_btrace_pt_config (&btrace->config); | |
1075 | ||
1076 | switch (type) | |
1077 | { | |
1078 | case BTRACE_READ_DELTA: | |
1079 | /* We don't support delta reads. The data head (i.e. aux_head) wraps | |
1080 | around to stay inside the aux buffer. */ | |
1081 | return BTRACE_ERR_NOT_SUPPORTED; | |
1082 | ||
1083 | case BTRACE_READ_NEW: | |
1084 | if (!perf_event_new_data (pt)) | |
1085 | return BTRACE_ERR_NONE; | |
1086 | ||
1087 | /* Fall through. */ | |
1088 | case BTRACE_READ_ALL: | |
1089 | perf_event_read_all (pt, &btrace->data, &btrace->size); | |
1090 | return BTRACE_ERR_NONE; | |
1091 | } | |
1092 | ||
1093 | internal_error (__FILE__, __LINE__, _("Unkown btrace read type.")); | |
1094 | } | |
1095 | ||
734b0e4b MM |
1096 | /* See linux-btrace.h. */ |
1097 | ||
1098 | enum btrace_error | |
1099 | linux_read_btrace (struct btrace_data *btrace, | |
1100 | struct btrace_target_info *tinfo, | |
1101 | enum btrace_read_type type) | |
1102 | { | |
f4abbc16 MM |
1103 | switch (tinfo->conf.format) |
1104 | { | |
1105 | case BTRACE_FORMAT_NONE: | |
1106 | return BTRACE_ERR_NOT_SUPPORTED; | |
1107 | ||
1108 | case BTRACE_FORMAT_BTS: | |
1109 | /* We read btrace in BTS format. */ | |
1110 | btrace->format = BTRACE_FORMAT_BTS; | |
1111 | btrace->variant.bts.blocks = NULL; | |
1112 | ||
1113 | return linux_read_bts (&btrace->variant.bts, tinfo, type); | |
b20a6524 MM |
1114 | |
1115 | case BTRACE_FORMAT_PT: | |
1116 | /* We read btrace in Intel(R) Processor Trace format. */ | |
1117 | btrace->format = BTRACE_FORMAT_PT; | |
1118 | btrace->variant.pt.data = NULL; | |
1119 | btrace->variant.pt.size = 0; | |
1120 | ||
1121 | return linux_read_pt (&btrace->variant.pt, tinfo, type); | |
f4abbc16 MM |
1122 | } |
1123 | ||
1124 | internal_error (__FILE__, __LINE__, _("Unkown branch trace format.")); | |
1125 | } | |
1126 | ||
1127 | /* See linux-btrace.h. */ | |
734b0e4b | 1128 | |
f4abbc16 MM |
1129 | const struct btrace_config * |
1130 | linux_btrace_conf (const struct btrace_target_info *tinfo) | |
1131 | { | |
1132 | return &tinfo->conf; | |
734b0e4b MM |
1133 | } |
1134 | ||
7c97f91e MM |
1135 | #else /* !HAVE_LINUX_PERF_EVENT_H */ |
1136 | ||
1137 | /* See linux-btrace.h. */ | |
1138 | ||
1139 | int | |
043c3577 | 1140 | linux_supports_btrace (struct target_ops *ops, enum btrace_format format) |
7c97f91e MM |
1141 | { |
1142 | return 0; | |
1143 | } | |
1144 | ||
1145 | /* See linux-btrace.h. */ | |
1146 | ||
1147 | struct btrace_target_info * | |
f4abbc16 | 1148 | linux_enable_btrace (ptid_t ptid, const struct btrace_config *conf) |
7c97f91e MM |
1149 | { |
1150 | return NULL; | |
1151 | } | |
1152 | ||
1153 | /* See linux-btrace.h. */ | |
1154 | ||
969c39fb | 1155 | enum btrace_error |
7c97f91e MM |
1156 | linux_disable_btrace (struct btrace_target_info *tinfo) |
1157 | { | |
969c39fb | 1158 | return BTRACE_ERR_NOT_SUPPORTED; |
7c97f91e MM |
1159 | } |
1160 | ||
1161 | /* See linux-btrace.h. */ | |
1162 | ||
969c39fb | 1163 | enum btrace_error |
734b0e4b | 1164 | linux_read_btrace (struct btrace_data *btrace, |
969c39fb | 1165 | struct btrace_target_info *tinfo, |
7c97f91e MM |
1166 | enum btrace_read_type type) |
1167 | { | |
969c39fb | 1168 | return BTRACE_ERR_NOT_SUPPORTED; |
7c97f91e MM |
1169 | } |
1170 | ||
f4abbc16 MM |
1171 | /* See linux-btrace.h. */ |
1172 | ||
1173 | const struct btrace_config * | |
1174 | linux_btrace_conf (const struct btrace_target_info *tinfo) | |
1175 | { | |
1176 | return NULL; | |
1177 | } | |
1178 | ||
7c97f91e | 1179 | #endif /* !HAVE_LINUX_PERF_EVENT_H */ |