xref: /linux/tools/perf/util/jitdump.c (revision 9e906a9dead17d81d6c2687f65e159231d0e3286)
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 "event.h"
18 #include "debug.h"
19 #include "dso.h"
20 #include "evlist.h"
21 #include "namespaces.h"
22 #include "symbol.h"
23 #include <elf.h>
24 
25 #include "tsc.h"
26 #include "session.h"
27 #include "jit.h"
28 #include "jitdump.h"
29 #include "genelf.h"
30 #include "thread.h"
31 
32 #include <linux/ctype.h>
33 #include <linux/zalloc.h>
34 
35 struct jit_buf_desc {
36 	struct perf_data *output;
37 	struct perf_session *session;
38 	struct machine *machine;
39 	struct nsinfo  *nsi;
40 	union jr_entry   *entry;
41 	void             *buf;
42 	uint64_t	 sample_type;
43 	size_t           bufsize;
44 	FILE             *in;
45 	bool		 needs_bswap; /* handles cross-endianness */
46 	bool		 use_arch_timestamp;
47 	void		 *debug_data;
48 	void		 *unwinding_data;
49 	uint64_t	 unwinding_size;
50 	uint64_t	 unwinding_mapped_size;
51 	uint64_t         eh_frame_hdr_size;
52 	size_t		 nr_debug_entries;
53 	uint32_t         code_load_count;
54 	u64		 bytes_written;
55 	struct rb_root   code_root;
56 	char		 dir[PATH_MAX];
57 };
58 
59 struct jit_tool {
60 	struct perf_tool tool;
61 	struct perf_data	output;
62 	struct perf_data	input;
63 	u64 bytes_written;
64 };
65 
66 #define hmax(a, b) ((a) > (b) ? (a) : (b))
67 #define get_jit_tool(t) (container_of(tool, struct jit_tool, tool))
68 
69 static int
jit_emit_elf(struct jit_buf_desc * jd,char * filename,const char * sym,uint64_t code_addr,const void * code,int csize,void * debug,int nr_debug_entries,void * unwinding,uint32_t unwinding_header_size,uint32_t unwinding_size)70 jit_emit_elf(struct jit_buf_desc *jd,
71 	     char *filename,
72 	     const char *sym,
73 	     uint64_t code_addr,
74 	     const void *code,
75 	     int csize,
76 	     void *debug,
77 	     int nr_debug_entries,
78 	     void *unwinding,
79 	     uint32_t unwinding_header_size,
80 	     uint32_t unwinding_size)
81 {
82 	int ret, fd, saved_errno;
83 	struct nscookie nsc;
84 
85 	if (verbose > 0)
86 		fprintf(stderr, "write ELF image %s\n", filename);
87 
88 	nsinfo__mountns_enter(jd->nsi, &nsc);
89 	fd = open(filename, O_CREAT|O_TRUNC|O_WRONLY, 0644);
90 	saved_errno = errno;
91 	nsinfo__mountns_exit(&nsc);
92 	if (fd == -1) {
93 		pr_warning("cannot create jit ELF %s: %s\n", filename, strerror(saved_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 		nsinfo__mountns_enter(jd->nsi, &nsc);
104 		unlink(filename);
105 		nsinfo__mountns_exit(&nsc);
106 	}
107 
108 	return ret;
109 }
110 
111 static void
jit_close(struct jit_buf_desc * jd)112 jit_close(struct jit_buf_desc *jd)
113 {
114 	if (!(jd && jd->in))
115 		return;
116 	funlockfile(jd->in);
117 	fclose(jd->in);
118 	jd->in = NULL;
119 }
120 
121 static int
jit_validate_events(struct perf_session * session)122 jit_validate_events(struct perf_session *session)
123 {
124 	struct evsel *evsel;
125 
126 	/*
127 	 * check that all events use CLOCK_MONOTONIC
128 	 */
129 	evlist__for_each_entry(session->evlist, evsel) {
130 		if (evsel->core.attr.use_clockid == 0 || evsel->core.attr.clockid != CLOCK_MONOTONIC)
131 			return -1;
132 	}
133 	return 0;
134 }
135 
136 static int
jit_open(struct jit_buf_desc * jd,const char * name)137 jit_open(struct jit_buf_desc *jd, const char *name)
138 {
139 	struct jitheader header;
140 	struct nscookie nsc;
141 	struct jr_prefix *prefix;
142 	ssize_t bs, bsz = 0;
143 	void *n, *buf = NULL;
144 	int ret, retval = -1;
145 
146 	nsinfo__mountns_enter(jd->nsi, &nsc);
147 	jd->in = fopen(name, "r");
148 	nsinfo__mountns_exit(&nsc);
149 	if (!jd->in)
150 		return -1;
151 
152 	bsz = hmax(sizeof(header), sizeof(*prefix));
153 
154 	buf = malloc(bsz);
155 	if (!buf)
156 		goto error;
157 
158 	/*
159 	 * protect from writer modifying the file while we are reading it
160 	 */
161 	flockfile(jd->in);
162 
163 	ret = fread(buf, sizeof(header), 1, jd->in);
164 	if (ret != 1)
165 		goto error;
166 
167 	memcpy(&header, buf, sizeof(header));
168 
169 	if (header.magic != JITHEADER_MAGIC) {
170 		if (header.magic != JITHEADER_MAGIC_SW)
171 			goto error;
172 		jd->needs_bswap = true;
173 	}
174 
175 	if (jd->needs_bswap) {
176 		header.version    = bswap_32(header.version);
177 		header.total_size = bswap_32(header.total_size);
178 		header.pid	  = bswap_32(header.pid);
179 		header.elf_mach   = bswap_32(header.elf_mach);
180 		header.timestamp  = bswap_64(header.timestamp);
181 		header.flags      = bswap_64(header.flags);
182 	}
183 
184 	jd->use_arch_timestamp = header.flags & JITDUMP_FLAGS_ARCH_TIMESTAMP;
185 
186 	if (verbose > 2)
187 		pr_debug("version=%u\nhdr.size=%u\nts=0x%llx\npid=%d\nelf_mach=%d\nuse_arch_timestamp=%d\n",
188 			header.version,
189 			header.total_size,
190 			(unsigned long long)header.timestamp,
191 			header.pid,
192 			header.elf_mach,
193 			jd->use_arch_timestamp);
194 
195 	if (header.version > JITHEADER_VERSION) {
196 		pr_err("wrong jitdump version %u, expected " __stringify(JITHEADER_VERSION),
197 			header.version);
198 		goto error;
199 	}
200 
201 	if (header.flags & JITDUMP_FLAGS_RESERVED) {
202 		pr_err("jitdump file contains invalid or unsupported flags 0x%llx\n",
203 		       (unsigned long long)header.flags & JITDUMP_FLAGS_RESERVED);
204 		goto error;
205 	}
206 
207 	if (jd->use_arch_timestamp && !jd->session->time_conv.time_mult) {
208 		pr_err("jitdump file uses arch timestamps but there is no timestamp conversion\n");
209 		goto error;
210 	}
211 
212 	/*
213 	 * validate event is using the correct clockid
214 	 */
215 	if (!jd->use_arch_timestamp && jit_validate_events(jd->session)) {
216 		pr_err("error, jitted code must be sampled with perf record -k 1\n");
217 		goto error;
218 	}
219 
220 	bs = header.total_size - sizeof(header);
221 
222 	if (bs > bsz) {
223 		n = realloc(buf, bs);
224 		if (!n)
225 			goto error;
226 		bsz = bs;
227 		buf = n;
228 		/* read extra we do not know about */
229 		ret = fread(buf, bs - bsz, 1, jd->in);
230 		if (ret != 1)
231 			goto error;
232 	}
233 	/*
234 	 * keep dirname for generating files and mmap records
235 	 */
236 	strncpy(jd->dir, name, PATH_MAX);
237 	jd->dir[PATH_MAX - 1] = '\0';
238 	dirname(jd->dir);
239 	free(buf);
240 
241 	return 0;
242 error:
243 	free(buf);
244 	funlockfile(jd->in);
245 	fclose(jd->in);
246 	return retval;
247 }
248 
249 static union jr_entry *
jit_get_next_entry(struct jit_buf_desc * jd)250 jit_get_next_entry(struct jit_buf_desc *jd)
251 {
252 	struct jr_prefix *prefix;
253 	union jr_entry *jr;
254 	void *addr;
255 	size_t bs, size;
256 	int id, ret;
257 
258 	if (!(jd && jd->in))
259 		return NULL;
260 
261 	if (jd->buf == NULL) {
262 		size_t sz = getpagesize();
263 		if (sz < sizeof(*prefix))
264 			sz = sizeof(*prefix);
265 
266 		jd->buf = malloc(sz);
267 		if (jd->buf == NULL)
268 			return NULL;
269 
270 		jd->bufsize = sz;
271 	}
272 
273 	prefix = jd->buf;
274 
275 	/*
276 	 * file is still locked at this point
277 	 */
278 	ret = fread(prefix, sizeof(*prefix), 1, jd->in);
279 	if (ret  != 1)
280 		return NULL;
281 
282 	if (jd->needs_bswap) {
283 		prefix->id   	   = bswap_32(prefix->id);
284 		prefix->total_size = bswap_32(prefix->total_size);
285 		prefix->timestamp  = bswap_64(prefix->timestamp);
286 	}
287 	id   = prefix->id;
288 	size = prefix->total_size;
289 
290 	bs = (size_t)size;
291 	if (bs < sizeof(*prefix))
292 		return NULL;
293 
294 	if (id >= JIT_CODE_MAX) {
295 		pr_warning("next_entry: unknown record type %d, skipping\n", id);
296 	}
297 	if (bs > jd->bufsize) {
298 		void *n;
299 		n = realloc(jd->buf, bs);
300 		if (!n)
301 			return NULL;
302 		jd->buf = n;
303 		jd->bufsize = bs;
304 	}
305 
306 	addr = ((void *)jd->buf) + sizeof(*prefix);
307 
308 	ret = fread(addr, bs - sizeof(*prefix), 1, jd->in);
309 	if (ret != 1)
310 		return NULL;
311 
312 	jr = (union jr_entry *)jd->buf;
313 
314 	switch(id) {
315 	case JIT_CODE_DEBUG_INFO:
316 		if (jd->needs_bswap) {
317 			uint64_t n;
318 			jr->info.code_addr = bswap_64(jr->info.code_addr);
319 			jr->info.nr_entry  = bswap_64(jr->info.nr_entry);
320 			for (n = 0 ; n < jr->info.nr_entry; n++) {
321 				jr->info.entries[n].addr    = bswap_64(jr->info.entries[n].addr);
322 				jr->info.entries[n].lineno  = bswap_32(jr->info.entries[n].lineno);
323 				jr->info.entries[n].discrim = bswap_32(jr->info.entries[n].discrim);
324 			}
325 		}
326 		break;
327 	case JIT_CODE_UNWINDING_INFO:
328 		if (jd->needs_bswap) {
329 			jr->unwinding.unwinding_size = bswap_64(jr->unwinding.unwinding_size);
330 			jr->unwinding.eh_frame_hdr_size = bswap_64(jr->unwinding.eh_frame_hdr_size);
331 			jr->unwinding.mapped_size = bswap_64(jr->unwinding.mapped_size);
332 		}
333 		break;
334 	case JIT_CODE_CLOSE:
335 		break;
336 	case JIT_CODE_LOAD:
337 		if (jd->needs_bswap) {
338 			jr->load.pid       = bswap_32(jr->load.pid);
339 			jr->load.tid       = bswap_32(jr->load.tid);
340 			jr->load.vma       = bswap_64(jr->load.vma);
341 			jr->load.code_addr = bswap_64(jr->load.code_addr);
342 			jr->load.code_size = bswap_64(jr->load.code_size);
343 			jr->load.code_index= bswap_64(jr->load.code_index);
344 		}
345 		jd->code_load_count++;
346 		break;
347 	case JIT_CODE_MOVE:
348 		if (jd->needs_bswap) {
349 			jr->move.pid           = bswap_32(jr->move.pid);
350 			jr->move.tid           = bswap_32(jr->move.tid);
351 			jr->move.vma           = bswap_64(jr->move.vma);
352 			jr->move.old_code_addr = bswap_64(jr->move.old_code_addr);
353 			jr->move.new_code_addr = bswap_64(jr->move.new_code_addr);
354 			jr->move.code_size     = bswap_64(jr->move.code_size);
355 			jr->move.code_index    = bswap_64(jr->move.code_index);
356 		}
357 		break;
358 	case JIT_CODE_MAX:
359 	default:
360 		/* skip unknown record (we have read them) */
361 		break;
362 	}
363 	return jr;
364 }
365 
366 static int
jit_inject_event(struct jit_buf_desc * jd,union perf_event * event)367 jit_inject_event(struct jit_buf_desc *jd, union perf_event *event)
368 {
369 	ssize_t size;
370 
371 	size = perf_data__write(jd->output, event, event->header.size);
372 	if (size < 0)
373 		return -1;
374 
375 	jd->bytes_written += size;
376 	return 0;
377 }
378 
jr_entry_pid(struct jit_buf_desc * jd,union jr_entry * jr)379 static pid_t jr_entry_pid(struct jit_buf_desc *jd, union jr_entry *jr)
380 {
381 	if (jd->nsi && nsinfo__in_pidns(jd->nsi))
382 		return nsinfo__tgid(jd->nsi);
383 	return jr->load.pid;
384 }
385 
jr_entry_tid(struct jit_buf_desc * jd,union jr_entry * jr)386 static pid_t jr_entry_tid(struct jit_buf_desc *jd, union jr_entry *jr)
387 {
388 	if (jd->nsi && nsinfo__in_pidns(jd->nsi))
389 		return nsinfo__pid(jd->nsi);
390 	return jr->load.tid;
391 }
392 
convert_timestamp(struct jit_buf_desc * jd,uint64_t timestamp)393 static uint64_t convert_timestamp(struct jit_buf_desc *jd, uint64_t timestamp)
394 {
395 	struct perf_tsc_conversion tc = { .time_shift = 0, };
396 	struct perf_record_time_conv *time_conv = &jd->session->time_conv;
397 
398 	if (!jd->use_arch_timestamp)
399 		return timestamp;
400 
401 	tc.time_shift = time_conv->time_shift;
402 	tc.time_mult  = time_conv->time_mult;
403 	tc.time_zero  = time_conv->time_zero;
404 
405 	/*
406 	 * The event TIME_CONV was extended for the fields from "time_cycles"
407 	 * when supported cap_user_time_short, for backward compatibility,
408 	 * checks the event size and assigns these extended fields if these
409 	 * fields are contained in the event.
410 	 */
411 	if (event_contains(*time_conv, time_cycles)) {
412 		tc.time_cycles	       = time_conv->time_cycles;
413 		tc.time_mask	       = time_conv->time_mask;
414 		tc.cap_user_time_zero  = time_conv->cap_user_time_zero;
415 		tc.cap_user_time_short = time_conv->cap_user_time_short;
416 
417 		if (!tc.cap_user_time_zero)
418 			return 0;
419 	}
420 
421 	return tsc_to_perf_time(timestamp, &tc);
422 }
423 
jit_repipe_code_load(struct jit_buf_desc * jd,union jr_entry * jr)424 static int jit_repipe_code_load(struct jit_buf_desc *jd, union jr_entry *jr)
425 {
426 	struct perf_sample sample;
427 	union perf_event *event;
428 	const struct perf_tool *tool = jd->session->tool;
429 	uint64_t code, addr;
430 	uintptr_t uaddr;
431 	char *filename;
432 	struct stat st;
433 	size_t size;
434 	u16 idr_size;
435 	const char *sym;
436 	uint64_t count;
437 	int ret, csize, usize;
438 	pid_t nspid, pid, tid;
439 	struct {
440 		u32 pid, tid;
441 		u64 time;
442 	} *id;
443 
444 	nspid = jr->load.pid;
445 	pid   = jr_entry_pid(jd, jr);
446 	tid   = jr_entry_tid(jd, jr);
447 	csize = jr->load.code_size;
448 	usize = jd->unwinding_mapped_size;
449 	addr  = jr->load.code_addr;
450 	sym   = (void *)((unsigned long)jr + sizeof(jr->load));
451 	code  = (unsigned long)jr + jr->load.p.total_size - csize;
452 	count = jr->load.code_index;
453 	idr_size = jd->machine->id_hdr_size;
454 
455 	event = calloc(1, sizeof(*event) + idr_size);
456 	if (!event)
457 		return -1;
458 
459 	filename = event->mmap2.filename;
460 	size = snprintf(filename, PATH_MAX, "%s/jitted-%d-%" PRIu64 ".so",
461 			jd->dir,
462 			nspid,
463 			count);
464 
465 	size++; /* for \0 */
466 
467 	size = PERF_ALIGN(size, sizeof(u64));
468 	uaddr = (uintptr_t)code;
469 	ret = jit_emit_elf(jd, filename, sym, addr, (const void *)uaddr, csize, jd->debug_data, jd->nr_debug_entries,
470 			   jd->unwinding_data, jd->eh_frame_hdr_size, jd->unwinding_size);
471 
472 	if (jd->debug_data && jd->nr_debug_entries) {
473 		zfree(&jd->debug_data);
474 		jd->nr_debug_entries = 0;
475 	}
476 
477 	if (jd->unwinding_data && jd->eh_frame_hdr_size) {
478 		zfree(&jd->unwinding_data);
479 		jd->eh_frame_hdr_size = 0;
480 		jd->unwinding_mapped_size = 0;
481 		jd->unwinding_size = 0;
482 	}
483 
484 	if (ret) {
485 		free(event);
486 		return -1;
487 	}
488 	if (nsinfo__stat(filename, &st, jd->nsi))
489 		memset(&st, 0, sizeof(st));
490 
491 	event->mmap2.header.type = PERF_RECORD_MMAP2;
492 	event->mmap2.header.misc = PERF_RECORD_MISC_USER;
493 	event->mmap2.header.size = (sizeof(event->mmap2) -
494 			(sizeof(event->mmap2.filename) - size) + idr_size);
495 
496 	event->mmap2.pgoff = GEN_ELF_TEXT_OFFSET;
497 	event->mmap2.start = addr;
498 	event->mmap2.len   = usize ? ALIGN_8(csize) + usize : csize;
499 	event->mmap2.pid   = pid;
500 	event->mmap2.tid   = tid;
501 	event->mmap2.ino   = st.st_ino;
502 	event->mmap2.maj   = major(st.st_dev);
503 	event->mmap2.min   = minor(st.st_dev);
504 	event->mmap2.prot  = st.st_mode;
505 	event->mmap2.flags = MAP_SHARED;
506 	event->mmap2.ino_generation = 1;
507 
508 	id = (void *)((unsigned long)event + event->mmap.header.size - idr_size);
509 	if (jd->sample_type & PERF_SAMPLE_TID) {
510 		id->pid  = pid;
511 		id->tid  = tid;
512 	}
513 	if (jd->sample_type & PERF_SAMPLE_TIME)
514 		id->time = convert_timestamp(jd, jr->load.p.timestamp);
515 
516 	/*
517 	 * create pseudo sample to induce dso hit increment
518 	 * use first address as sample address
519 	 */
520 	perf_sample__init(&sample, /*all=*/true);
521 	sample.cpumode = PERF_RECORD_MISC_USER;
522 	sample.pid  = pid;
523 	sample.tid  = tid;
524 	sample.time = id->time;
525 	sample.ip   = addr;
526 
527 	ret = perf_event__process_mmap2(tool, event, &sample, jd->machine);
528 	if (ret)
529 		goto out;
530 
531 	ret = jit_inject_event(jd, event);
532 	/*
533 	 * mark dso as use to generate buildid in the header
534 	 */
535 	if (!ret) {
536 		struct dso_id dso_id = {
537 			{
538 				.maj = event->mmap2.maj,
539 				.min = event->mmap2.min,
540 				.ino = event->mmap2.ino,
541 				.ino_generation = event->mmap2.ino_generation,
542 			},
543 			.mmap2_valid = true,
544 			.mmap2_ino_generation_valid = true,
545 		};
546 		struct dso *dso = machine__findnew_dso_id(jd->machine, filename, &dso_id);
547 
548 		if (dso)
549 			dso__set_hit(dso);
550 
551 		dso__put(dso);
552 	}
553 out:
554 	perf_sample__exit(&sample);
555 	free(event);
556 	return ret;
557 }
558 
jit_repipe_code_move(struct jit_buf_desc * jd,union jr_entry * jr)559 static int jit_repipe_code_move(struct jit_buf_desc *jd, union jr_entry *jr)
560 {
561 	struct perf_sample sample;
562 	union perf_event *event;
563 	const struct perf_tool *tool = jd->session->tool;
564 	char *filename;
565 	size_t size;
566 	struct stat st;
567 	int usize;
568 	u16 idr_size;
569 	int ret;
570 	pid_t nspid, pid, tid;
571 	struct {
572 		u32 pid, tid;
573 		u64 time;
574 	} *id;
575 
576 	nspid = jr->load.pid;
577 	pid   = jr_entry_pid(jd, jr);
578 	tid   = jr_entry_tid(jd, jr);
579 	usize = jd->unwinding_mapped_size;
580 	idr_size = jd->machine->id_hdr_size;
581 
582 	/*
583 	 * +16 to account for sample_id_all (hack)
584 	 */
585 	event = calloc(1, sizeof(*event) + 16);
586 	if (!event)
587 		return -1;
588 
589 	filename = event->mmap2.filename;
590 	size = snprintf(filename, PATH_MAX, "%s/jitted-%d-%" PRIu64 ".so",
591 	         jd->dir,
592 		 nspid,
593 		 jr->move.code_index);
594 
595 	size++; /* for \0 */
596 
597 	if (nsinfo__stat(filename, &st, jd->nsi))
598 		memset(&st, 0, sizeof(st));
599 
600 	size = PERF_ALIGN(size, sizeof(u64));
601 
602 	event->mmap2.header.type = PERF_RECORD_MMAP2;
603 	event->mmap2.header.misc = PERF_RECORD_MISC_USER;
604 	event->mmap2.header.size = (sizeof(event->mmap2) -
605 			(sizeof(event->mmap2.filename) - size) + idr_size);
606 	event->mmap2.pgoff = GEN_ELF_TEXT_OFFSET;
607 	event->mmap2.start = jr->move.new_code_addr;
608 	event->mmap2.len   = usize ? ALIGN_8(jr->move.code_size) + usize
609 				   : jr->move.code_size;
610 	event->mmap2.pid   = pid;
611 	event->mmap2.tid   = tid;
612 	event->mmap2.ino   = st.st_ino;
613 	event->mmap2.maj   = major(st.st_dev);
614 	event->mmap2.min   = minor(st.st_dev);
615 	event->mmap2.prot  = st.st_mode;
616 	event->mmap2.flags = MAP_SHARED;
617 	event->mmap2.ino_generation = 1;
618 
619 	id = (void *)((unsigned long)event + event->mmap.header.size - idr_size);
620 	if (jd->sample_type & PERF_SAMPLE_TID) {
621 		id->pid  = pid;
622 		id->tid  = tid;
623 	}
624 	if (jd->sample_type & PERF_SAMPLE_TIME)
625 		id->time = convert_timestamp(jd, jr->load.p.timestamp);
626 
627 	/*
628 	 * create pseudo sample to induce dso hit increment
629 	 * use first address as sample address
630 	 */
631 	perf_sample__init(&sample, /*all=*/true);
632 	sample.cpumode = PERF_RECORD_MISC_USER;
633 	sample.pid  = pid;
634 	sample.tid  = tid;
635 	sample.time = id->time;
636 	sample.ip   = jr->move.new_code_addr;
637 
638 	ret = perf_event__process_mmap2(tool, event, &sample, jd->machine);
639 	if (ret)
640 		goto out;
641 
642 	ret = jit_inject_event(jd, event);
643 	if (!ret)
644 		build_id__mark_dso_hit(tool, event, &sample, NULL, jd->machine);
645 out:
646 	perf_sample__exit(&sample);
647 	return ret;
648 }
649 
jit_repipe_debug_info(struct jit_buf_desc * jd,union jr_entry * jr)650 static int jit_repipe_debug_info(struct jit_buf_desc *jd, union jr_entry *jr)
651 {
652 	void *data;
653 	size_t sz;
654 
655 	if (!(jd && jr))
656 		return -1;
657 
658 	sz  = jr->prefix.total_size - sizeof(jr->info);
659 	data = malloc(sz);
660 	if (!data)
661 		return -1;
662 
663 	memcpy(data, &jr->info.entries, sz);
664 
665 	jd->debug_data       = data;
666 
667 	/*
668 	 * we must use nr_entry instead of size here because
669 	 * we cannot distinguish actual entry from padding otherwise
670 	 */
671 	jd->nr_debug_entries = jr->info.nr_entry;
672 
673 	return 0;
674 }
675 
676 static int
jit_repipe_unwinding_info(struct jit_buf_desc * jd,union jr_entry * jr)677 jit_repipe_unwinding_info(struct jit_buf_desc *jd, union jr_entry *jr)
678 {
679 	void *unwinding_data;
680 	uint32_t unwinding_data_size;
681 
682 	if (!(jd && jr))
683 		return -1;
684 
685 	unwinding_data_size  = jr->prefix.total_size - sizeof(jr->unwinding);
686 	unwinding_data = malloc(unwinding_data_size);
687 	if (!unwinding_data)
688 		return -1;
689 
690 	memcpy(unwinding_data, &jr->unwinding.unwinding_data,
691 	       unwinding_data_size);
692 
693 	jd->eh_frame_hdr_size = jr->unwinding.eh_frame_hdr_size;
694 	jd->unwinding_size = jr->unwinding.unwinding_size;
695 	jd->unwinding_mapped_size = jr->unwinding.mapped_size;
696 	free(jd->unwinding_data);
697 	jd->unwinding_data = unwinding_data;
698 
699 	return 0;
700 }
701 
702 static int
jit_process_dump(struct jit_buf_desc * jd)703 jit_process_dump(struct jit_buf_desc *jd)
704 {
705 	union jr_entry *jr;
706 	int ret = 0;
707 
708 	while ((jr = jit_get_next_entry(jd))) {
709 		switch(jr->prefix.id) {
710 		case JIT_CODE_LOAD:
711 			ret = jit_repipe_code_load(jd, jr);
712 			break;
713 		case JIT_CODE_MOVE:
714 			ret = jit_repipe_code_move(jd, jr);
715 			break;
716 		case JIT_CODE_DEBUG_INFO:
717 			ret = jit_repipe_debug_info(jd, jr);
718 			break;
719 		case JIT_CODE_UNWINDING_INFO:
720 			ret = jit_repipe_unwinding_info(jd, jr);
721 			break;
722 		default:
723 			ret = 0;
724 			continue;
725 		}
726 	}
727 	return ret;
728 }
729 
730 static int
jit_inject(struct jit_buf_desc * jd,const char * path)731 jit_inject(struct jit_buf_desc *jd, const char *path)
732 {
733 	int ret;
734 
735 	if (verbose > 0)
736 		fprintf(stderr, "injecting: %s\n", path);
737 
738 	ret = jit_open(jd, path);
739 	if (ret)
740 		return -1;
741 
742 	ret = jit_process_dump(jd);
743 
744 	jit_close(jd);
745 
746 	if (verbose > 0)
747 		fprintf(stderr, "injected: %s (%d)\n", path, ret);
748 
749 	return 0;
750 }
751 
752 /*
753  * File must be with pattern .../jit-XXXX.dump
754  * where XXXX is the PID of the process which did the mmap()
755  * as captured in the RECORD_MMAP record
756  */
757 static int
jit_detect(const char * mmap_name,pid_t pid,struct nsinfo * nsi,bool * in_pidns)758 jit_detect(const char *mmap_name, pid_t pid, struct nsinfo *nsi, bool *in_pidns)
759  {
760 	char *p;
761 	char *end = NULL;
762 	pid_t pid2;
763 
764 	if (verbose > 2)
765 		fprintf(stderr, "jit marker trying : %s\n", mmap_name);
766 	/*
767 	 * get file name
768 	 */
769 	p = strrchr(mmap_name, '/');
770 	if (!p)
771 		return -1;
772 
773 	/*
774 	 * match prefix
775 	 */
776 	if (strncmp(p, "/jit-", 5))
777 		return -1;
778 
779 	/*
780 	 * skip prefix
781 	 */
782 	p += 5;
783 
784 	/*
785 	 * must be followed by a pid
786 	 */
787 	if (!isdigit(*p))
788 		return -1;
789 
790 	pid2 = (int)strtol(p, &end, 10);
791 	if (!end)
792 		return -1;
793 
794 	*in_pidns = pid == nsinfo__nstgid(nsi);
795 	/*
796 	 * pid does not match mmap pid
797 	 * pid==0 in system-wide mode (synthesized)
798 	 *
799 	 * If the pid in the file name is equal to the nstgid, then
800 	 * the agent ran inside a container and perf outside the
801 	 * container, so record it for further use in jit_inject().
802 	 */
803 	if (pid && !(pid2 == pid || *in_pidns))
804 		return -1;
805 	/*
806 	 * validate suffix
807 	 */
808 	if (strcmp(end, ".dump"))
809 		return -1;
810 
811 	if (verbose > 0)
812 		fprintf(stderr, "jit marker found: %s\n", mmap_name);
813 
814 	return 0;
815 }
816 
jit_add_pid(struct machine * machine,pid_t pid)817 static void jit_add_pid(struct machine *machine, pid_t pid)
818 {
819 	struct thread *thread = machine__findnew_thread(machine, pid, pid);
820 
821 	if (!thread) {
822 		pr_err("%s: thread %d not found or created\n", __func__, pid);
823 		return;
824 	}
825 
826 	thread__set_priv(thread, (void *)true);
827 	thread__put(thread);
828 }
829 
jit_has_pid(struct machine * machine,pid_t pid)830 static bool jit_has_pid(struct machine *machine, pid_t pid)
831 {
832 	struct thread *thread = machine__find_thread(machine, pid, pid);
833 	void *priv;
834 
835 	if (!thread)
836 		return false;
837 
838 	priv = thread__priv(thread);
839 	thread__put(thread);
840 	return (bool)priv;
841 }
842 
843 int
jit_process(struct perf_session * session,struct perf_data * output,struct machine * machine,const char * filename,pid_t pid,pid_t tid,u64 * nbytes)844 jit_process(struct perf_session *session,
845 	    struct perf_data *output,
846 	    struct machine *machine,
847 	    const char *filename,
848 	    pid_t pid,
849 	    pid_t tid,
850 	    u64 *nbytes)
851 {
852 	struct thread *thread;
853 	struct nsinfo *nsi;
854 	struct evsel *first;
855 	struct jit_buf_desc jd;
856 	bool in_pidns = false;
857 	int ret;
858 
859 	thread = machine__findnew_thread(machine, pid, tid);
860 	if (thread == NULL) {
861 		pr_err("problem processing JIT mmap event, skipping it.\n");
862 		return 0;
863 	}
864 
865 	nsi = nsinfo__get(thread__nsinfo(thread));
866 	thread__put(thread);
867 
868 	/*
869 	 * first, detect marker mmap (i.e., the jitdump mmap)
870 	 */
871 	if (jit_detect(filename, pid, nsi, &in_pidns)) {
872 		nsinfo__put(nsi);
873 
874 		/*
875 		 * Strip //anon*, [anon:* and /memfd:* mmaps if we processed a jitdump for this pid
876 		 */
877 		if (jit_has_pid(machine, pid) &&
878 			((strncmp(filename, "//anon", 6) == 0) ||
879 			 (strncmp(filename, "[anon:", 6) == 0) ||
880 			 (strncmp(filename, "/memfd:", 7) == 0)))
881 			return 1;
882 
883 		return 0;
884 	}
885 
886 	memset(&jd, 0, sizeof(jd));
887 
888 	jd.session = session;
889 	jd.output  = output;
890 	jd.machine = machine;
891 	jd.nsi = nsi;
892 
893 	if (in_pidns)
894 		nsinfo__set_in_pidns(nsi);
895 
896 	/*
897 	 * track sample_type to compute id_all layout
898 	 * perf sets the same sample type to all events as of now
899 	 */
900 	first = evlist__first(session->evlist);
901 	jd.sample_type = first->core.attr.sample_type;
902 
903 	*nbytes = 0;
904 
905 	ret = jit_inject(&jd, filename);
906 	if (!ret) {
907 		jit_add_pid(machine, pid);
908 		*nbytes = jd.bytes_written;
909 		ret = 1;
910 	}
911 
912 	nsinfo__put(jd.nsi);
913 	free(jd.buf);
914 
915 	return ret;
916 }
917