xref: /openbmc/linux/tools/perf/util/jitdump.c (revision 59b4412f)
1 // SPDX-License-Identifier: GPL-2.0
2 #include <sys/sysmacros.h>
3 #include <sys/types.h>
4 #include <errno.h>
5 #include <libgen.h>
6 #include <stdio.h>
7 #include <stdlib.h>
8 #include <string.h>
9 #include <fcntl.h>
10 #include <unistd.h>
11 #include <inttypes.h>
12 #include <byteswap.h>
13 #include <sys/stat.h>
14 #include <sys/mman.h>
15 #include <linux/stringify.h>
16 
17 #include "build-id.h"
18 #include "event.h"
19 #include "debug.h"
20 #include "evlist.h"
21 #include "symbol.h"
22 #include <elf.h>
23 
24 #include "tsc.h"
25 #include "session.h"
26 #include "jit.h"
27 #include "jitdump.h"
28 #include "genelf.h"
29 #include "thread.h"
30 
31 #include <linux/ctype.h>
32 #include <linux/zalloc.h>
33 
34 struct jit_buf_desc {
35 	struct perf_data *output;
36 	struct perf_session *session;
37 	struct machine *machine;
38 	union jr_entry   *entry;
39 	void             *buf;
40 	uint64_t	 sample_type;
41 	size_t           bufsize;
42 	FILE             *in;
43 	bool		 needs_bswap; /* handles cross-endianness */
44 	bool		 use_arch_timestamp;
45 	void		 *debug_data;
46 	void		 *unwinding_data;
47 	uint64_t	 unwinding_size;
48 	uint64_t	 unwinding_mapped_size;
49 	uint64_t         eh_frame_hdr_size;
50 	size_t		 nr_debug_entries;
51 	uint32_t         code_load_count;
52 	u64		 bytes_written;
53 	struct rb_root   code_root;
54 	char		 dir[PATH_MAX];
55 };
56 
57 struct debug_line_info {
58 	unsigned long vma;
59 	unsigned int lineno;
60 	/* The filename format is unspecified, absolute path, relative etc. */
61 	char const filename[];
62 };
63 
64 struct jit_tool {
65 	struct perf_tool tool;
66 	struct perf_data	output;
67 	struct perf_data	input;
68 	u64 bytes_written;
69 };
70 
71 #define hmax(a, b) ((a) > (b) ? (a) : (b))
72 #define get_jit_tool(t) (container_of(tool, struct jit_tool, tool))
73 
74 static int
75 jit_emit_elf(char *filename,
76 	     const char *sym,
77 	     uint64_t code_addr,
78 	     const void *code,
79 	     int csize,
80 	     void *debug,
81 	     int nr_debug_entries,
82 	     void *unwinding,
83 	     uint32_t unwinding_header_size,
84 	     uint32_t unwinding_size)
85 {
86 	int ret, fd;
87 
88 	if (verbose > 0)
89 		fprintf(stderr, "write ELF image %s\n", filename);
90 
91 	fd = open(filename, O_CREAT|O_TRUNC|O_WRONLY, 0644);
92 	if (fd == -1) {
93 		pr_warning("cannot create jit ELF %s: %s\n", filename, strerror(errno));
94 		return -1;
95 	}
96 
97 	ret = jit_write_elf(fd, code_addr, sym, (const void *)code, csize, debug, nr_debug_entries,
98 			    unwinding, unwinding_header_size, unwinding_size);
99 
100         close(fd);
101 
102         if (ret)
103                 unlink(filename);
104 
105 	return ret;
106 }
107 
108 static void
109 jit_close(struct jit_buf_desc *jd)
110 {
111 	if (!(jd && jd->in))
112 		return;
113 	funlockfile(jd->in);
114 	fclose(jd->in);
115 	jd->in = NULL;
116 }
117 
118 static int
119 jit_validate_events(struct perf_session *session)
120 {
121 	struct evsel *evsel;
122 
123 	/*
124 	 * check that all events use CLOCK_MONOTONIC
125 	 */
126 	evlist__for_each_entry(session->evlist, evsel) {
127 		if (evsel->core.attr.use_clockid == 0 || evsel->core.attr.clockid != CLOCK_MONOTONIC)
128 			return -1;
129 	}
130 	return 0;
131 }
132 
133 static int
134 jit_open(struct jit_buf_desc *jd, const char *name)
135 {
136 	struct jitheader header;
137 	struct jr_prefix *prefix;
138 	ssize_t bs, bsz = 0;
139 	void *n, *buf = NULL;
140 	int ret, retval = -1;
141 
142 	jd->in = fopen(name, "r");
143 	if (!jd->in)
144 		return -1;
145 
146 	bsz = hmax(sizeof(header), sizeof(*prefix));
147 
148 	buf = malloc(bsz);
149 	if (!buf)
150 		goto error;
151 
152 	/*
153 	 * protect from writer modifying the file while we are reading it
154 	 */
155 	flockfile(jd->in);
156 
157 	ret = fread(buf, sizeof(header), 1, jd->in);
158 	if (ret != 1)
159 		goto error;
160 
161 	memcpy(&header, buf, sizeof(header));
162 
163 	if (header.magic != JITHEADER_MAGIC) {
164 		if (header.magic != JITHEADER_MAGIC_SW)
165 			goto error;
166 		jd->needs_bswap = true;
167 	}
168 
169 	if (jd->needs_bswap) {
170 		header.version    = bswap_32(header.version);
171 		header.total_size = bswap_32(header.total_size);
172 		header.pid	  = bswap_32(header.pid);
173 		header.elf_mach   = bswap_32(header.elf_mach);
174 		header.timestamp  = bswap_64(header.timestamp);
175 		header.flags      = bswap_64(header.flags);
176 	}
177 
178 	jd->use_arch_timestamp = header.flags & JITDUMP_FLAGS_ARCH_TIMESTAMP;
179 
180 	if (verbose > 2)
181 		pr_debug("version=%u\nhdr.size=%u\nts=0x%llx\npid=%d\nelf_mach=%d\nuse_arch_timestamp=%d\n",
182 			header.version,
183 			header.total_size,
184 			(unsigned long long)header.timestamp,
185 			header.pid,
186 			header.elf_mach,
187 			jd->use_arch_timestamp);
188 
189 	if (header.version > JITHEADER_VERSION) {
190 		pr_err("wrong jitdump version %u, expected " __stringify(JITHEADER_VERSION),
191 			header.version);
192 		goto error;
193 	}
194 
195 	if (header.flags & JITDUMP_FLAGS_RESERVED) {
196 		pr_err("jitdump file contains invalid or unsupported flags 0x%llx\n",
197 		       (unsigned long long)header.flags & JITDUMP_FLAGS_RESERVED);
198 		goto error;
199 	}
200 
201 	if (jd->use_arch_timestamp && !jd->session->time_conv.time_mult) {
202 		pr_err("jitdump file uses arch timestamps but there is no timestamp conversion\n");
203 		goto error;
204 	}
205 
206 	/*
207 	 * validate event is using the correct clockid
208 	 */
209 	if (!jd->use_arch_timestamp && jit_validate_events(jd->session)) {
210 		pr_err("error, jitted code must be sampled with perf record -k 1\n");
211 		goto error;
212 	}
213 
214 	bs = header.total_size - sizeof(header);
215 
216 	if (bs > bsz) {
217 		n = realloc(buf, bs);
218 		if (!n)
219 			goto error;
220 		bsz = bs;
221 		buf = n;
222 		/* read extra we do not know about */
223 		ret = fread(buf, bs - bsz, 1, jd->in);
224 		if (ret != 1)
225 			goto error;
226 	}
227 	/*
228 	 * keep dirname for generating files and mmap records
229 	 */
230 	strcpy(jd->dir, name);
231 	dirname(jd->dir);
232 
233 	return 0;
234 error:
235 	funlockfile(jd->in);
236 	fclose(jd->in);
237 	return retval;
238 }
239 
240 static union jr_entry *
241 jit_get_next_entry(struct jit_buf_desc *jd)
242 {
243 	struct jr_prefix *prefix;
244 	union jr_entry *jr;
245 	void *addr;
246 	size_t bs, size;
247 	int id, ret;
248 
249 	if (!(jd && jd->in))
250 		return NULL;
251 
252 	if (jd->buf == NULL) {
253 		size_t sz = getpagesize();
254 		if (sz < sizeof(*prefix))
255 			sz = sizeof(*prefix);
256 
257 		jd->buf = malloc(sz);
258 		if (jd->buf == NULL)
259 			return NULL;
260 
261 		jd->bufsize = sz;
262 	}
263 
264 	prefix = jd->buf;
265 
266 	/*
267 	 * file is still locked at this point
268 	 */
269 	ret = fread(prefix, sizeof(*prefix), 1, jd->in);
270 	if (ret  != 1)
271 		return NULL;
272 
273 	if (jd->needs_bswap) {
274 		prefix->id   	   = bswap_32(prefix->id);
275 		prefix->total_size = bswap_32(prefix->total_size);
276 		prefix->timestamp  = bswap_64(prefix->timestamp);
277 	}
278 	id   = prefix->id;
279 	size = prefix->total_size;
280 
281 	bs = (size_t)size;
282 	if (bs < sizeof(*prefix))
283 		return NULL;
284 
285 	if (id >= JIT_CODE_MAX) {
286 		pr_warning("next_entry: unknown record type %d, skipping\n", id);
287 	}
288 	if (bs > jd->bufsize) {
289 		void *n;
290 		n = realloc(jd->buf, bs);
291 		if (!n)
292 			return NULL;
293 		jd->buf = n;
294 		jd->bufsize = bs;
295 	}
296 
297 	addr = ((void *)jd->buf) + sizeof(*prefix);
298 
299 	ret = fread(addr, bs - sizeof(*prefix), 1, jd->in);
300 	if (ret != 1)
301 		return NULL;
302 
303 	jr = (union jr_entry *)jd->buf;
304 
305 	switch(id) {
306 	case JIT_CODE_DEBUG_INFO:
307 		if (jd->needs_bswap) {
308 			uint64_t n;
309 			jr->info.code_addr = bswap_64(jr->info.code_addr);
310 			jr->info.nr_entry  = bswap_64(jr->info.nr_entry);
311 			for (n = 0 ; n < jr->info.nr_entry; n++) {
312 				jr->info.entries[n].addr    = bswap_64(jr->info.entries[n].addr);
313 				jr->info.entries[n].lineno  = bswap_32(jr->info.entries[n].lineno);
314 				jr->info.entries[n].discrim = bswap_32(jr->info.entries[n].discrim);
315 			}
316 		}
317 		break;
318 	case JIT_CODE_UNWINDING_INFO:
319 		if (jd->needs_bswap) {
320 			jr->unwinding.unwinding_size = bswap_64(jr->unwinding.unwinding_size);
321 			jr->unwinding.eh_frame_hdr_size = bswap_64(jr->unwinding.eh_frame_hdr_size);
322 			jr->unwinding.mapped_size = bswap_64(jr->unwinding.mapped_size);
323 		}
324 		break;
325 	case JIT_CODE_CLOSE:
326 		break;
327 	case JIT_CODE_LOAD:
328 		if (jd->needs_bswap) {
329 			jr->load.pid       = bswap_32(jr->load.pid);
330 			jr->load.tid       = bswap_32(jr->load.tid);
331 			jr->load.vma       = bswap_64(jr->load.vma);
332 			jr->load.code_addr = bswap_64(jr->load.code_addr);
333 			jr->load.code_size = bswap_64(jr->load.code_size);
334 			jr->load.code_index= bswap_64(jr->load.code_index);
335 		}
336 		jd->code_load_count++;
337 		break;
338 	case JIT_CODE_MOVE:
339 		if (jd->needs_bswap) {
340 			jr->move.pid           = bswap_32(jr->move.pid);
341 			jr->move.tid           = bswap_32(jr->move.tid);
342 			jr->move.vma           = bswap_64(jr->move.vma);
343 			jr->move.old_code_addr = bswap_64(jr->move.old_code_addr);
344 			jr->move.new_code_addr = bswap_64(jr->move.new_code_addr);
345 			jr->move.code_size     = bswap_64(jr->move.code_size);
346 			jr->move.code_index    = bswap_64(jr->move.code_index);
347 		}
348 		break;
349 	case JIT_CODE_MAX:
350 	default:
351 		/* skip unknown record (we have read them) */
352 		break;
353 	}
354 	return jr;
355 }
356 
357 static int
358 jit_inject_event(struct jit_buf_desc *jd, union perf_event *event)
359 {
360 	ssize_t size;
361 
362 	size = perf_data__write(jd->output, event, event->header.size);
363 	if (size < 0)
364 		return -1;
365 
366 	jd->bytes_written += size;
367 	return 0;
368 }
369 
370 static uint64_t convert_timestamp(struct jit_buf_desc *jd, uint64_t timestamp)
371 {
372 	struct perf_tsc_conversion tc;
373 
374 	if (!jd->use_arch_timestamp)
375 		return timestamp;
376 
377 	tc.time_shift = jd->session->time_conv.time_shift;
378 	tc.time_mult  = jd->session->time_conv.time_mult;
379 	tc.time_zero  = jd->session->time_conv.time_zero;
380 
381 	if (!tc.time_mult)
382 		return 0;
383 
384 	return tsc_to_perf_time(timestamp, &tc);
385 }
386 
387 static int jit_repipe_code_load(struct jit_buf_desc *jd, union jr_entry *jr)
388 {
389 	struct perf_sample sample;
390 	union perf_event *event;
391 	struct perf_tool *tool = jd->session->tool;
392 	uint64_t code, addr;
393 	uintptr_t uaddr;
394 	char *filename;
395 	struct stat st;
396 	size_t size;
397 	u16 idr_size;
398 	const char *sym;
399 	uint64_t count;
400 	int ret, csize, usize;
401 	pid_t pid, tid;
402 	struct {
403 		u32 pid, tid;
404 		u64 time;
405 	} *id;
406 
407 	pid   = jr->load.pid;
408 	tid   = jr->load.tid;
409 	csize = jr->load.code_size;
410 	usize = jd->unwinding_mapped_size;
411 	addr  = jr->load.code_addr;
412 	sym   = (void *)((unsigned long)jr + sizeof(jr->load));
413 	code  = (unsigned long)jr + jr->load.p.total_size - csize;
414 	count = jr->load.code_index;
415 	idr_size = jd->machine->id_hdr_size;
416 
417 	event = calloc(1, sizeof(*event) + idr_size);
418 	if (!event)
419 		return -1;
420 
421 	filename = event->mmap2.filename;
422 	size = snprintf(filename, PATH_MAX, "%s/jitted-%d-%" PRIu64 ".so",
423 			jd->dir,
424 			pid,
425 			count);
426 
427 	size++; /* for \0 */
428 
429 	size = PERF_ALIGN(size, sizeof(u64));
430 	uaddr = (uintptr_t)code;
431 	ret = jit_emit_elf(filename, sym, addr, (const void *)uaddr, csize, jd->debug_data, jd->nr_debug_entries,
432 			   jd->unwinding_data, jd->eh_frame_hdr_size, jd->unwinding_size);
433 
434 	if (jd->debug_data && jd->nr_debug_entries) {
435 		zfree(&jd->debug_data);
436 		jd->nr_debug_entries = 0;
437 	}
438 
439 	if (jd->unwinding_data && jd->eh_frame_hdr_size) {
440 		zfree(&jd->unwinding_data);
441 		jd->eh_frame_hdr_size = 0;
442 		jd->unwinding_mapped_size = 0;
443 		jd->unwinding_size = 0;
444 	}
445 
446 	if (ret) {
447 		free(event);
448 		return -1;
449 	}
450 	if (stat(filename, &st))
451 		memset(&st, 0, sizeof(st));
452 
453 	event->mmap2.header.type = PERF_RECORD_MMAP2;
454 	event->mmap2.header.misc = PERF_RECORD_MISC_USER;
455 	event->mmap2.header.size = (sizeof(event->mmap2) -
456 			(sizeof(event->mmap2.filename) - size) + idr_size);
457 
458 	event->mmap2.pgoff = GEN_ELF_TEXT_OFFSET;
459 	event->mmap2.start = addr;
460 	event->mmap2.len   = usize ? ALIGN_8(csize) + usize : csize;
461 	event->mmap2.pid   = pid;
462 	event->mmap2.tid   = tid;
463 	event->mmap2.ino   = st.st_ino;
464 	event->mmap2.maj   = major(st.st_dev);
465 	event->mmap2.min   = minor(st.st_dev);
466 	event->mmap2.prot  = st.st_mode;
467 	event->mmap2.flags = MAP_SHARED;
468 	event->mmap2.ino_generation = 1;
469 
470 	id = (void *)((unsigned long)event + event->mmap.header.size - idr_size);
471 	if (jd->sample_type & PERF_SAMPLE_TID) {
472 		id->pid  = pid;
473 		id->tid  = tid;
474 	}
475 	if (jd->sample_type & PERF_SAMPLE_TIME)
476 		id->time = convert_timestamp(jd, jr->load.p.timestamp);
477 
478 	/*
479 	 * create pseudo sample to induce dso hit increment
480 	 * use first address as sample address
481 	 */
482 	memset(&sample, 0, sizeof(sample));
483 	sample.cpumode = PERF_RECORD_MISC_USER;
484 	sample.pid  = pid;
485 	sample.tid  = tid;
486 	sample.time = id->time;
487 	sample.ip   = addr;
488 
489 	ret = perf_event__process_mmap2(tool, event, &sample, jd->machine);
490 	if (ret)
491 		return ret;
492 
493 	ret = jit_inject_event(jd, event);
494 	/*
495 	 * mark dso as use to generate buildid in the header
496 	 */
497 	if (!ret)
498 		build_id__mark_dso_hit(tool, event, &sample, NULL, jd->machine);
499 
500 	return ret;
501 }
502 
503 static int jit_repipe_code_move(struct jit_buf_desc *jd, union jr_entry *jr)
504 {
505 	struct perf_sample sample;
506 	union perf_event *event;
507 	struct perf_tool *tool = jd->session->tool;
508 	char *filename;
509 	size_t size;
510 	struct stat st;
511 	int usize;
512 	u16 idr_size;
513 	int ret;
514 	pid_t pid, tid;
515 	struct {
516 		u32 pid, tid;
517 		u64 time;
518 	} *id;
519 
520 	pid = jr->move.pid;
521 	tid =  jr->move.tid;
522 	usize = jd->unwinding_mapped_size;
523 	idr_size = jd->machine->id_hdr_size;
524 
525 	/*
526 	 * +16 to account for sample_id_all (hack)
527 	 */
528 	event = calloc(1, sizeof(*event) + 16);
529 	if (!event)
530 		return -1;
531 
532 	filename = event->mmap2.filename;
533 	size = snprintf(filename, PATH_MAX, "%s/jitted-%d-%" PRIu64 ".so",
534 	         jd->dir,
535 	         pid,
536 		 jr->move.code_index);
537 
538 	size++; /* for \0 */
539 
540 	if (stat(filename, &st))
541 		memset(&st, 0, sizeof(st));
542 
543 	size = PERF_ALIGN(size, sizeof(u64));
544 
545 	event->mmap2.header.type = PERF_RECORD_MMAP2;
546 	event->mmap2.header.misc = PERF_RECORD_MISC_USER;
547 	event->mmap2.header.size = (sizeof(event->mmap2) -
548 			(sizeof(event->mmap2.filename) - size) + idr_size);
549 	event->mmap2.pgoff = GEN_ELF_TEXT_OFFSET;
550 	event->mmap2.start = jr->move.new_code_addr;
551 	event->mmap2.len   = usize ? ALIGN_8(jr->move.code_size) + usize
552 				   : jr->move.code_size;
553 	event->mmap2.pid   = pid;
554 	event->mmap2.tid   = tid;
555 	event->mmap2.ino   = st.st_ino;
556 	event->mmap2.maj   = major(st.st_dev);
557 	event->mmap2.min   = minor(st.st_dev);
558 	event->mmap2.prot  = st.st_mode;
559 	event->mmap2.flags = MAP_SHARED;
560 	event->mmap2.ino_generation = 1;
561 
562 	id = (void *)((unsigned long)event + event->mmap.header.size - idr_size);
563 	if (jd->sample_type & PERF_SAMPLE_TID) {
564 		id->pid  = pid;
565 		id->tid  = tid;
566 	}
567 	if (jd->sample_type & PERF_SAMPLE_TIME)
568 		id->time = convert_timestamp(jd, jr->load.p.timestamp);
569 
570 	/*
571 	 * create pseudo sample to induce dso hit increment
572 	 * use first address as sample address
573 	 */
574 	memset(&sample, 0, sizeof(sample));
575 	sample.cpumode = PERF_RECORD_MISC_USER;
576 	sample.pid  = pid;
577 	sample.tid  = tid;
578 	sample.time = id->time;
579 	sample.ip   = jr->move.new_code_addr;
580 
581 	ret = perf_event__process_mmap2(tool, event, &sample, jd->machine);
582 	if (ret)
583 		return ret;
584 
585 	ret = jit_inject_event(jd, event);
586 	if (!ret)
587 		build_id__mark_dso_hit(tool, event, &sample, NULL, jd->machine);
588 
589 	return ret;
590 }
591 
592 static int jit_repipe_debug_info(struct jit_buf_desc *jd, union jr_entry *jr)
593 {
594 	void *data;
595 	size_t sz;
596 
597 	if (!(jd && jr))
598 		return -1;
599 
600 	sz  = jr->prefix.total_size - sizeof(jr->info);
601 	data = malloc(sz);
602 	if (!data)
603 		return -1;
604 
605 	memcpy(data, &jr->info.entries, sz);
606 
607 	jd->debug_data       = data;
608 
609 	/*
610 	 * we must use nr_entry instead of size here because
611 	 * we cannot distinguish actual entry from padding otherwise
612 	 */
613 	jd->nr_debug_entries = jr->info.nr_entry;
614 
615 	return 0;
616 }
617 
618 static int
619 jit_repipe_unwinding_info(struct jit_buf_desc *jd, union jr_entry *jr)
620 {
621 	void *unwinding_data;
622 	uint32_t unwinding_data_size;
623 
624 	if (!(jd && jr))
625 		return -1;
626 
627 	unwinding_data_size  = jr->prefix.total_size - sizeof(jr->unwinding);
628 	unwinding_data = malloc(unwinding_data_size);
629 	if (!unwinding_data)
630 		return -1;
631 
632 	memcpy(unwinding_data, &jr->unwinding.unwinding_data,
633 	       unwinding_data_size);
634 
635 	jd->eh_frame_hdr_size = jr->unwinding.eh_frame_hdr_size;
636 	jd->unwinding_size = jr->unwinding.unwinding_size;
637 	jd->unwinding_mapped_size = jr->unwinding.mapped_size;
638 	jd->unwinding_data = unwinding_data;
639 
640 	return 0;
641 }
642 
643 static int
644 jit_process_dump(struct jit_buf_desc *jd)
645 {
646 	union jr_entry *jr;
647 	int ret = 0;
648 
649 	while ((jr = jit_get_next_entry(jd))) {
650 		switch(jr->prefix.id) {
651 		case JIT_CODE_LOAD:
652 			ret = jit_repipe_code_load(jd, jr);
653 			break;
654 		case JIT_CODE_MOVE:
655 			ret = jit_repipe_code_move(jd, jr);
656 			break;
657 		case JIT_CODE_DEBUG_INFO:
658 			ret = jit_repipe_debug_info(jd, jr);
659 			break;
660 		case JIT_CODE_UNWINDING_INFO:
661 			ret = jit_repipe_unwinding_info(jd, jr);
662 			break;
663 		default:
664 			ret = 0;
665 			continue;
666 		}
667 	}
668 	return ret;
669 }
670 
671 static int
672 jit_inject(struct jit_buf_desc *jd, char *path)
673 {
674 	int ret;
675 
676 	if (verbose > 0)
677 		fprintf(stderr, "injecting: %s\n", path);
678 
679 	ret = jit_open(jd, path);
680 	if (ret)
681 		return -1;
682 
683 	ret = jit_process_dump(jd);
684 
685 	jit_close(jd);
686 
687 	if (verbose > 0)
688 		fprintf(stderr, "injected: %s (%d)\n", path, ret);
689 
690 	return 0;
691 }
692 
693 /*
694  * File must be with pattern .../jit-XXXX.dump
695  * where XXXX is the PID of the process which did the mmap()
696  * as captured in the RECORD_MMAP record
697  */
698 static int
699 jit_detect(char *mmap_name, pid_t pid)
700  {
701 	char *p;
702 	char *end = NULL;
703 	pid_t pid2;
704 
705 	if (verbose > 2)
706 		fprintf(stderr, "jit marker trying : %s\n", mmap_name);
707 	/*
708 	 * get file name
709 	 */
710 	p = strrchr(mmap_name, '/');
711 	if (!p)
712 		return -1;
713 
714 	/*
715 	 * match prefix
716 	 */
717 	if (strncmp(p, "/jit-", 5))
718 		return -1;
719 
720 	/*
721 	 * skip prefix
722 	 */
723 	p += 5;
724 
725 	/*
726 	 * must be followed by a pid
727 	 */
728 	if (!isdigit(*p))
729 		return -1;
730 
731 	pid2 = (int)strtol(p, &end, 10);
732 	if (!end)
733 		return -1;
734 
735 	/*
736 	 * pid does not match mmap pid
737 	 * pid==0 in system-wide mode (synthesized)
738 	 */
739 	if (pid && pid2 != pid)
740 		return -1;
741 	/*
742 	 * validate suffix
743 	 */
744 	if (strcmp(end, ".dump"))
745 		return -1;
746 
747 	if (verbose > 0)
748 		fprintf(stderr, "jit marker found: %s\n", mmap_name);
749 
750 	return 0;
751 }
752 
753 static void jit_add_pid(struct machine *machine, pid_t pid)
754 {
755 	struct thread *thread = machine__findnew_thread(machine, pid, pid);
756 
757 	if (!thread) {
758 		pr_err("%s: thread %d not found or created\n", __func__, pid);
759 		return;
760 	}
761 
762 	thread->priv = (void *)1;
763 }
764 
765 static bool jit_has_pid(struct machine *machine, pid_t pid)
766 {
767 	struct thread *thread = machine__find_thread(machine, pid, pid);
768 
769 	if (!thread)
770 		return 0;
771 
772 	return (bool)thread->priv;
773 }
774 
775 int
776 jit_process(struct perf_session *session,
777 	    struct perf_data *output,
778 	    struct machine *machine,
779 	    char *filename,
780 	    pid_t pid,
781 	    u64 *nbytes)
782 {
783 	struct evsel *first;
784 	struct jit_buf_desc jd;
785 	int ret;
786 
787 	/*
788 	 * first, detect marker mmap (i.e., the jitdump mmap)
789 	 */
790 	if (jit_detect(filename, pid)) {
791 		// Strip //anon* mmaps if we processed a jitdump for this pid
792 		if (jit_has_pid(machine, pid) && (strncmp(filename, "//anon", 6) == 0))
793 			return 1;
794 
795 		return 0;
796 	}
797 
798 	memset(&jd, 0, sizeof(jd));
799 
800 	jd.session = session;
801 	jd.output  = output;
802 	jd.machine = machine;
803 
804 	/*
805 	 * track sample_type to compute id_all layout
806 	 * perf sets the same sample type to all events as of now
807 	 */
808 	first = evlist__first(session->evlist);
809 	jd.sample_type = first->core.attr.sample_type;
810 
811 	*nbytes = 0;
812 
813 	ret = jit_inject(&jd, filename);
814 	if (!ret) {
815 		jit_add_pid(machine, pid);
816 		*nbytes = jd.bytes_written;
817 		ret = 1;
818 	}
819 
820 	return ret;
821 }
822