xref: /linux/tools/perf/util/jitdump.c (revision f4f346c3465949ebba80c6cc52cd8d2eeaa545fd)
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 	strcpy(jd->dir, name);
237 	dirname(jd->dir);
238 	free(buf);
239 
240 	return 0;
241 error:
242 	free(buf);
243 	funlockfile(jd->in);
244 	fclose(jd->in);
245 	return retval;
246 }
247 
248 static union jr_entry *
jit_get_next_entry(struct jit_buf_desc * jd)249 jit_get_next_entry(struct jit_buf_desc *jd)
250 {
251 	struct jr_prefix *prefix;
252 	union jr_entry *jr;
253 	void *addr;
254 	size_t bs, size;
255 	int id, ret;
256 
257 	if (!(jd && jd->in))
258 		return NULL;
259 
260 	if (jd->buf == NULL) {
261 		size_t sz = getpagesize();
262 		if (sz < sizeof(*prefix))
263 			sz = sizeof(*prefix);
264 
265 		jd->buf = malloc(sz);
266 		if (jd->buf == NULL)
267 			return NULL;
268 
269 		jd->bufsize = sz;
270 	}
271 
272 	prefix = jd->buf;
273 
274 	/*
275 	 * file is still locked at this point
276 	 */
277 	ret = fread(prefix, sizeof(*prefix), 1, jd->in);
278 	if (ret  != 1)
279 		return NULL;
280 
281 	if (jd->needs_bswap) {
282 		prefix->id   	   = bswap_32(prefix->id);
283 		prefix->total_size = bswap_32(prefix->total_size);
284 		prefix->timestamp  = bswap_64(prefix->timestamp);
285 	}
286 	id   = prefix->id;
287 	size = prefix->total_size;
288 
289 	bs = (size_t)size;
290 	if (bs < sizeof(*prefix))
291 		return NULL;
292 
293 	if (id >= JIT_CODE_MAX) {
294 		pr_warning("next_entry: unknown record type %d, skipping\n", id);
295 	}
296 	if (bs > jd->bufsize) {
297 		void *n;
298 		n = realloc(jd->buf, bs);
299 		if (!n)
300 			return NULL;
301 		jd->buf = n;
302 		jd->bufsize = bs;
303 	}
304 
305 	addr = ((void *)jd->buf) + sizeof(*prefix);
306 
307 	ret = fread(addr, bs - sizeof(*prefix), 1, jd->in);
308 	if (ret != 1)
309 		return NULL;
310 
311 	jr = (union jr_entry *)jd->buf;
312 
313 	switch(id) {
314 	case JIT_CODE_DEBUG_INFO:
315 		if (jd->needs_bswap) {
316 			uint64_t n;
317 			jr->info.code_addr = bswap_64(jr->info.code_addr);
318 			jr->info.nr_entry  = bswap_64(jr->info.nr_entry);
319 			for (n = 0 ; n < jr->info.nr_entry; n++) {
320 				jr->info.entries[n].addr    = bswap_64(jr->info.entries[n].addr);
321 				jr->info.entries[n].lineno  = bswap_32(jr->info.entries[n].lineno);
322 				jr->info.entries[n].discrim = bswap_32(jr->info.entries[n].discrim);
323 			}
324 		}
325 		break;
326 	case JIT_CODE_UNWINDING_INFO:
327 		if (jd->needs_bswap) {
328 			jr->unwinding.unwinding_size = bswap_64(jr->unwinding.unwinding_size);
329 			jr->unwinding.eh_frame_hdr_size = bswap_64(jr->unwinding.eh_frame_hdr_size);
330 			jr->unwinding.mapped_size = bswap_64(jr->unwinding.mapped_size);
331 		}
332 		break;
333 	case JIT_CODE_CLOSE:
334 		break;
335 	case JIT_CODE_LOAD:
336 		if (jd->needs_bswap) {
337 			jr->load.pid       = bswap_32(jr->load.pid);
338 			jr->load.tid       = bswap_32(jr->load.tid);
339 			jr->load.vma       = bswap_64(jr->load.vma);
340 			jr->load.code_addr = bswap_64(jr->load.code_addr);
341 			jr->load.code_size = bswap_64(jr->load.code_size);
342 			jr->load.code_index= bswap_64(jr->load.code_index);
343 		}
344 		jd->code_load_count++;
345 		break;
346 	case JIT_CODE_MOVE:
347 		if (jd->needs_bswap) {
348 			jr->move.pid           = bswap_32(jr->move.pid);
349 			jr->move.tid           = bswap_32(jr->move.tid);
350 			jr->move.vma           = bswap_64(jr->move.vma);
351 			jr->move.old_code_addr = bswap_64(jr->move.old_code_addr);
352 			jr->move.new_code_addr = bswap_64(jr->move.new_code_addr);
353 			jr->move.code_size     = bswap_64(jr->move.code_size);
354 			jr->move.code_index    = bswap_64(jr->move.code_index);
355 		}
356 		break;
357 	case JIT_CODE_MAX:
358 	default:
359 		/* skip unknown record (we have read them) */
360 		break;
361 	}
362 	return jr;
363 }
364 
365 static int
jit_inject_event(struct jit_buf_desc * jd,union perf_event * event)366 jit_inject_event(struct jit_buf_desc *jd, union perf_event *event)
367 {
368 	ssize_t size;
369 
370 	size = perf_data__write(jd->output, event, event->header.size);
371 	if (size < 0)
372 		return -1;
373 
374 	jd->bytes_written += size;
375 	return 0;
376 }
377 
jr_entry_pid(struct jit_buf_desc * jd,union jr_entry * jr)378 static pid_t jr_entry_pid(struct jit_buf_desc *jd, union jr_entry *jr)
379 {
380 	if (jd->nsi && nsinfo__in_pidns(jd->nsi))
381 		return nsinfo__tgid(jd->nsi);
382 	return jr->load.pid;
383 }
384 
jr_entry_tid(struct jit_buf_desc * jd,union jr_entry * jr)385 static pid_t jr_entry_tid(struct jit_buf_desc *jd, union jr_entry *jr)
386 {
387 	if (jd->nsi && nsinfo__in_pidns(jd->nsi))
388 		return nsinfo__pid(jd->nsi);
389 	return jr->load.tid;
390 }
391 
convert_timestamp(struct jit_buf_desc * jd,uint64_t timestamp)392 static uint64_t convert_timestamp(struct jit_buf_desc *jd, uint64_t timestamp)
393 {
394 	struct perf_tsc_conversion tc = { .time_shift = 0, };
395 	struct perf_record_time_conv *time_conv = &jd->session->time_conv;
396 
397 	if (!jd->use_arch_timestamp)
398 		return timestamp;
399 
400 	tc.time_shift = time_conv->time_shift;
401 	tc.time_mult  = time_conv->time_mult;
402 	tc.time_zero  = time_conv->time_zero;
403 
404 	/*
405 	 * The event TIME_CONV was extended for the fields from "time_cycles"
406 	 * when supported cap_user_time_short, for backward compatibility,
407 	 * checks the event size and assigns these extended fields if these
408 	 * fields are contained in the event.
409 	 */
410 	if (event_contains(*time_conv, time_cycles)) {
411 		tc.time_cycles	       = time_conv->time_cycles;
412 		tc.time_mask	       = time_conv->time_mask;
413 		tc.cap_user_time_zero  = time_conv->cap_user_time_zero;
414 		tc.cap_user_time_short = time_conv->cap_user_time_short;
415 
416 		if (!tc.cap_user_time_zero)
417 			return 0;
418 	}
419 
420 	return tsc_to_perf_time(timestamp, &tc);
421 }
422 
jit_repipe_code_load(struct jit_buf_desc * jd,union jr_entry * jr)423 static int jit_repipe_code_load(struct jit_buf_desc *jd, union jr_entry *jr)
424 {
425 	struct perf_sample sample;
426 	union perf_event *event;
427 	const struct perf_tool *tool = jd->session->tool;
428 	uint64_t code, addr;
429 	uintptr_t uaddr;
430 	char *filename;
431 	struct stat st;
432 	size_t size;
433 	u16 idr_size;
434 	const char *sym;
435 	uint64_t count;
436 	int ret, csize, usize;
437 	pid_t nspid, pid, tid;
438 	struct {
439 		u32 pid, tid;
440 		u64 time;
441 	} *id;
442 
443 	nspid = jr->load.pid;
444 	pid   = jr_entry_pid(jd, jr);
445 	tid   = jr_entry_tid(jd, jr);
446 	csize = jr->load.code_size;
447 	usize = jd->unwinding_mapped_size;
448 	addr  = jr->load.code_addr;
449 	sym   = (void *)((unsigned long)jr + sizeof(jr->load));
450 	code  = (unsigned long)jr + jr->load.p.total_size - csize;
451 	count = jr->load.code_index;
452 	idr_size = jd->machine->id_hdr_size;
453 
454 	event = calloc(1, sizeof(*event) + idr_size);
455 	if (!event)
456 		return -1;
457 
458 	filename = event->mmap2.filename;
459 	size = snprintf(filename, PATH_MAX, "%s/jitted-%d-%" PRIu64 ".so",
460 			jd->dir,
461 			nspid,
462 			count);
463 
464 	size++; /* for \0 */
465 
466 	size = PERF_ALIGN(size, sizeof(u64));
467 	uaddr = (uintptr_t)code;
468 	ret = jit_emit_elf(jd, filename, sym, addr, (const void *)uaddr, csize, jd->debug_data, jd->nr_debug_entries,
469 			   jd->unwinding_data, jd->eh_frame_hdr_size, jd->unwinding_size);
470 
471 	if (jd->debug_data && jd->nr_debug_entries) {
472 		zfree(&jd->debug_data);
473 		jd->nr_debug_entries = 0;
474 	}
475 
476 	if (jd->unwinding_data && jd->eh_frame_hdr_size) {
477 		zfree(&jd->unwinding_data);
478 		jd->eh_frame_hdr_size = 0;
479 		jd->unwinding_mapped_size = 0;
480 		jd->unwinding_size = 0;
481 	}
482 
483 	if (ret) {
484 		free(event);
485 		return -1;
486 	}
487 	if (nsinfo__stat(filename, &st, jd->nsi))
488 		memset(&st, 0, sizeof(st));
489 
490 	event->mmap2.header.type = PERF_RECORD_MMAP2;
491 	event->mmap2.header.misc = PERF_RECORD_MISC_USER;
492 	event->mmap2.header.size = (sizeof(event->mmap2) -
493 			(sizeof(event->mmap2.filename) - size) + idr_size);
494 
495 	event->mmap2.pgoff = GEN_ELF_TEXT_OFFSET;
496 	event->mmap2.start = addr;
497 	event->mmap2.len   = usize ? ALIGN_8(csize) + usize : csize;
498 	event->mmap2.pid   = pid;
499 	event->mmap2.tid   = tid;
500 	event->mmap2.ino   = st.st_ino;
501 	event->mmap2.maj   = major(st.st_dev);
502 	event->mmap2.min   = minor(st.st_dev);
503 	event->mmap2.prot  = st.st_mode;
504 	event->mmap2.flags = MAP_SHARED;
505 	event->mmap2.ino_generation = 1;
506 
507 	id = (void *)((unsigned long)event + event->mmap.header.size - idr_size);
508 	if (jd->sample_type & PERF_SAMPLE_TID) {
509 		id->pid  = pid;
510 		id->tid  = tid;
511 	}
512 	if (jd->sample_type & PERF_SAMPLE_TIME)
513 		id->time = convert_timestamp(jd, jr->load.p.timestamp);
514 
515 	/*
516 	 * create pseudo sample to induce dso hit increment
517 	 * use first address as sample address
518 	 */
519 	perf_sample__init(&sample, /*all=*/true);
520 	sample.cpumode = PERF_RECORD_MISC_USER;
521 	sample.pid  = pid;
522 	sample.tid  = tid;
523 	sample.time = id->time;
524 	sample.ip   = addr;
525 
526 	ret = perf_event__process_mmap2(tool, event, &sample, jd->machine);
527 	if (ret)
528 		goto out;
529 
530 	ret = jit_inject_event(jd, event);
531 	/*
532 	 * mark dso as use to generate buildid in the header
533 	 */
534 	if (!ret) {
535 		struct dso_id dso_id = {
536 			{
537 				.maj = event->mmap2.maj,
538 				.min = event->mmap2.min,
539 				.ino = event->mmap2.ino,
540 				.ino_generation = event->mmap2.ino_generation,
541 			},
542 			.mmap2_valid = true,
543 			.mmap2_ino_generation_valid = true,
544 		};
545 		struct dso *dso = machine__findnew_dso_id(jd->machine, filename, &dso_id);
546 
547 		if (dso)
548 			dso__set_hit(dso);
549 	}
550 out:
551 	perf_sample__exit(&sample);
552 	free(event);
553 	return ret;
554 }
555 
jit_repipe_code_move(struct jit_buf_desc * jd,union jr_entry * jr)556 static int jit_repipe_code_move(struct jit_buf_desc *jd, union jr_entry *jr)
557 {
558 	struct perf_sample sample;
559 	union perf_event *event;
560 	const struct perf_tool *tool = jd->session->tool;
561 	char *filename;
562 	size_t size;
563 	struct stat st;
564 	int usize;
565 	u16 idr_size;
566 	int ret;
567 	pid_t nspid, pid, tid;
568 	struct {
569 		u32 pid, tid;
570 		u64 time;
571 	} *id;
572 
573 	nspid = jr->load.pid;
574 	pid   = jr_entry_pid(jd, jr);
575 	tid   = jr_entry_tid(jd, jr);
576 	usize = jd->unwinding_mapped_size;
577 	idr_size = jd->machine->id_hdr_size;
578 
579 	/*
580 	 * +16 to account for sample_id_all (hack)
581 	 */
582 	event = calloc(1, sizeof(*event) + 16);
583 	if (!event)
584 		return -1;
585 
586 	filename = event->mmap2.filename;
587 	size = snprintf(filename, PATH_MAX, "%s/jitted-%d-%" PRIu64 ".so",
588 	         jd->dir,
589 		 nspid,
590 		 jr->move.code_index);
591 
592 	size++; /* for \0 */
593 
594 	if (nsinfo__stat(filename, &st, jd->nsi))
595 		memset(&st, 0, sizeof(st));
596 
597 	size = PERF_ALIGN(size, sizeof(u64));
598 
599 	event->mmap2.header.type = PERF_RECORD_MMAP2;
600 	event->mmap2.header.misc = PERF_RECORD_MISC_USER;
601 	event->mmap2.header.size = (sizeof(event->mmap2) -
602 			(sizeof(event->mmap2.filename) - size) + idr_size);
603 	event->mmap2.pgoff = GEN_ELF_TEXT_OFFSET;
604 	event->mmap2.start = jr->move.new_code_addr;
605 	event->mmap2.len   = usize ? ALIGN_8(jr->move.code_size) + usize
606 				   : jr->move.code_size;
607 	event->mmap2.pid   = pid;
608 	event->mmap2.tid   = tid;
609 	event->mmap2.ino   = st.st_ino;
610 	event->mmap2.maj   = major(st.st_dev);
611 	event->mmap2.min   = minor(st.st_dev);
612 	event->mmap2.prot  = st.st_mode;
613 	event->mmap2.flags = MAP_SHARED;
614 	event->mmap2.ino_generation = 1;
615 
616 	id = (void *)((unsigned long)event + event->mmap.header.size - idr_size);
617 	if (jd->sample_type & PERF_SAMPLE_TID) {
618 		id->pid  = pid;
619 		id->tid  = tid;
620 	}
621 	if (jd->sample_type & PERF_SAMPLE_TIME)
622 		id->time = convert_timestamp(jd, jr->load.p.timestamp);
623 
624 	/*
625 	 * create pseudo sample to induce dso hit increment
626 	 * use first address as sample address
627 	 */
628 	perf_sample__init(&sample, /*all=*/true);
629 	sample.cpumode = PERF_RECORD_MISC_USER;
630 	sample.pid  = pid;
631 	sample.tid  = tid;
632 	sample.time = id->time;
633 	sample.ip   = jr->move.new_code_addr;
634 
635 	ret = perf_event__process_mmap2(tool, event, &sample, jd->machine);
636 	if (ret)
637 		goto out;
638 
639 	ret = jit_inject_event(jd, event);
640 	if (!ret)
641 		build_id__mark_dso_hit(tool, event, &sample, NULL, jd->machine);
642 out:
643 	perf_sample__exit(&sample);
644 	return ret;
645 }
646 
jit_repipe_debug_info(struct jit_buf_desc * jd,union jr_entry * jr)647 static int jit_repipe_debug_info(struct jit_buf_desc *jd, union jr_entry *jr)
648 {
649 	void *data;
650 	size_t sz;
651 
652 	if (!(jd && jr))
653 		return -1;
654 
655 	sz  = jr->prefix.total_size - sizeof(jr->info);
656 	data = malloc(sz);
657 	if (!data)
658 		return -1;
659 
660 	memcpy(data, &jr->info.entries, sz);
661 
662 	jd->debug_data       = data;
663 
664 	/*
665 	 * we must use nr_entry instead of size here because
666 	 * we cannot distinguish actual entry from padding otherwise
667 	 */
668 	jd->nr_debug_entries = jr->info.nr_entry;
669 
670 	return 0;
671 }
672 
673 static int
jit_repipe_unwinding_info(struct jit_buf_desc * jd,union jr_entry * jr)674 jit_repipe_unwinding_info(struct jit_buf_desc *jd, union jr_entry *jr)
675 {
676 	void *unwinding_data;
677 	uint32_t unwinding_data_size;
678 
679 	if (!(jd && jr))
680 		return -1;
681 
682 	unwinding_data_size  = jr->prefix.total_size - sizeof(jr->unwinding);
683 	unwinding_data = malloc(unwinding_data_size);
684 	if (!unwinding_data)
685 		return -1;
686 
687 	memcpy(unwinding_data, &jr->unwinding.unwinding_data,
688 	       unwinding_data_size);
689 
690 	jd->eh_frame_hdr_size = jr->unwinding.eh_frame_hdr_size;
691 	jd->unwinding_size = jr->unwinding.unwinding_size;
692 	jd->unwinding_mapped_size = jr->unwinding.mapped_size;
693 	free(jd->unwinding_data);
694 	jd->unwinding_data = unwinding_data;
695 
696 	return 0;
697 }
698 
699 static int
jit_process_dump(struct jit_buf_desc * jd)700 jit_process_dump(struct jit_buf_desc *jd)
701 {
702 	union jr_entry *jr;
703 	int ret = 0;
704 
705 	while ((jr = jit_get_next_entry(jd))) {
706 		switch(jr->prefix.id) {
707 		case JIT_CODE_LOAD:
708 			ret = jit_repipe_code_load(jd, jr);
709 			break;
710 		case JIT_CODE_MOVE:
711 			ret = jit_repipe_code_move(jd, jr);
712 			break;
713 		case JIT_CODE_DEBUG_INFO:
714 			ret = jit_repipe_debug_info(jd, jr);
715 			break;
716 		case JIT_CODE_UNWINDING_INFO:
717 			ret = jit_repipe_unwinding_info(jd, jr);
718 			break;
719 		default:
720 			ret = 0;
721 			continue;
722 		}
723 	}
724 	return ret;
725 }
726 
727 static int
jit_inject(struct jit_buf_desc * jd,const char * path)728 jit_inject(struct jit_buf_desc *jd, const char *path)
729 {
730 	int ret;
731 
732 	if (verbose > 0)
733 		fprintf(stderr, "injecting: %s\n", path);
734 
735 	ret = jit_open(jd, path);
736 	if (ret)
737 		return -1;
738 
739 	ret = jit_process_dump(jd);
740 
741 	jit_close(jd);
742 
743 	if (verbose > 0)
744 		fprintf(stderr, "injected: %s (%d)\n", path, ret);
745 
746 	return 0;
747 }
748 
749 /*
750  * File must be with pattern .../jit-XXXX.dump
751  * where XXXX is the PID of the process which did the mmap()
752  * as captured in the RECORD_MMAP record
753  */
754 static int
jit_detect(const char * mmap_name,pid_t pid,struct nsinfo * nsi,bool * in_pidns)755 jit_detect(const char *mmap_name, pid_t pid, struct nsinfo *nsi, bool *in_pidns)
756  {
757 	char *p;
758 	char *end = NULL;
759 	pid_t pid2;
760 
761 	if (verbose > 2)
762 		fprintf(stderr, "jit marker trying : %s\n", mmap_name);
763 	/*
764 	 * get file name
765 	 */
766 	p = strrchr(mmap_name, '/');
767 	if (!p)
768 		return -1;
769 
770 	/*
771 	 * match prefix
772 	 */
773 	if (strncmp(p, "/jit-", 5))
774 		return -1;
775 
776 	/*
777 	 * skip prefix
778 	 */
779 	p += 5;
780 
781 	/*
782 	 * must be followed by a pid
783 	 */
784 	if (!isdigit(*p))
785 		return -1;
786 
787 	pid2 = (int)strtol(p, &end, 10);
788 	if (!end)
789 		return -1;
790 
791 	*in_pidns = pid == nsinfo__nstgid(nsi);
792 	/*
793 	 * pid does not match mmap pid
794 	 * pid==0 in system-wide mode (synthesized)
795 	 *
796 	 * If the pid in the file name is equal to the nstgid, then
797 	 * the agent ran inside a container and perf outside the
798 	 * container, so record it for further use in jit_inject().
799 	 */
800 	if (pid && !(pid2 == pid || *in_pidns))
801 		return -1;
802 	/*
803 	 * validate suffix
804 	 */
805 	if (strcmp(end, ".dump"))
806 		return -1;
807 
808 	if (verbose > 0)
809 		fprintf(stderr, "jit marker found: %s\n", mmap_name);
810 
811 	return 0;
812 }
813 
jit_add_pid(struct machine * machine,pid_t pid)814 static void jit_add_pid(struct machine *machine, pid_t pid)
815 {
816 	struct thread *thread = machine__findnew_thread(machine, pid, pid);
817 
818 	if (!thread) {
819 		pr_err("%s: thread %d not found or created\n", __func__, pid);
820 		return;
821 	}
822 
823 	thread__set_priv(thread, (void *)true);
824 	thread__put(thread);
825 }
826 
jit_has_pid(struct machine * machine,pid_t pid)827 static bool jit_has_pid(struct machine *machine, pid_t pid)
828 {
829 	struct thread *thread = machine__find_thread(machine, pid, pid);
830 	void *priv;
831 
832 	if (!thread)
833 		return false;
834 
835 	priv = thread__priv(thread);
836 	thread__put(thread);
837 	return (bool)priv;
838 }
839 
840 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)841 jit_process(struct perf_session *session,
842 	    struct perf_data *output,
843 	    struct machine *machine,
844 	    const char *filename,
845 	    pid_t pid,
846 	    pid_t tid,
847 	    u64 *nbytes)
848 {
849 	struct thread *thread;
850 	struct nsinfo *nsi;
851 	struct evsel *first;
852 	struct jit_buf_desc jd;
853 	bool in_pidns = false;
854 	int ret;
855 
856 	thread = machine__findnew_thread(machine, pid, tid);
857 	if (thread == NULL) {
858 		pr_err("problem processing JIT mmap event, skipping it.\n");
859 		return 0;
860 	}
861 
862 	nsi = nsinfo__get(thread__nsinfo(thread));
863 	thread__put(thread);
864 
865 	/*
866 	 * first, detect marker mmap (i.e., the jitdump mmap)
867 	 */
868 	if (jit_detect(filename, pid, nsi, &in_pidns)) {
869 		nsinfo__put(nsi);
870 
871 		/*
872 		 * Strip //anon*, [anon:* and /memfd:* mmaps if we processed a jitdump for this pid
873 		 */
874 		if (jit_has_pid(machine, pid) &&
875 			((strncmp(filename, "//anon", 6) == 0) ||
876 			 (strncmp(filename, "[anon:", 6) == 0) ||
877 			 (strncmp(filename, "/memfd:", 7) == 0)))
878 			return 1;
879 
880 		return 0;
881 	}
882 
883 	memset(&jd, 0, sizeof(jd));
884 
885 	jd.session = session;
886 	jd.output  = output;
887 	jd.machine = machine;
888 	jd.nsi = nsi;
889 
890 	if (in_pidns)
891 		nsinfo__set_in_pidns(nsi);
892 
893 	/*
894 	 * track sample_type to compute id_all layout
895 	 * perf sets the same sample type to all events as of now
896 	 */
897 	first = evlist__first(session->evlist);
898 	jd.sample_type = first->core.attr.sample_type;
899 
900 	*nbytes = 0;
901 
902 	ret = jit_inject(&jd, filename);
903 	if (!ret) {
904 		jit_add_pid(machine, pid);
905 		*nbytes = jd.bytes_written;
906 		ret = 1;
907 	}
908 
909 	nsinfo__put(jd.nsi);
910 	free(jd.buf);
911 
912 	return ret;
913 }
914