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