1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * probe-event.c : perf-probe definition to probe_events format converter
4  *
5  * Written by Masami Hiramatsu <mhiramat@redhat.com>
6  */
7 
8 #include <inttypes.h>
9 #include <sys/utsname.h>
10 #include <sys/types.h>
11 #include <sys/stat.h>
12 #include <fcntl.h>
13 #include <errno.h>
14 #include <stdio.h>
15 #include <unistd.h>
16 #include <stdlib.h>
17 #include <string.h>
18 #include <stdarg.h>
19 #include <limits.h>
20 #include <elf.h>
21 
22 #include "build-id.h"
23 #include "event.h"
24 #include "namespaces.h"
25 #include "strlist.h"
26 #include "strfilter.h"
27 #include "debug.h"
28 #include "dso.h"
29 #include "color.h"
30 #include "map.h"
31 #include "maps.h"
32 #include "symbol.h"
33 #include <api/fs/fs.h>
34 #include "trace-event.h"	/* For __maybe_unused */
35 #include "probe-event.h"
36 #include "probe-finder.h"
37 #include "probe-file.h"
38 #include "session.h"
39 #include "string2.h"
40 #include "strbuf.h"
41 
42 #include <subcmd/pager.h>
43 #include <linux/ctype.h>
44 #include <linux/zalloc.h>
45 
46 #ifdef HAVE_DEBUGINFOD_SUPPORT
47 #include <elfutils/debuginfod.h>
48 #endif
49 
50 #define PERFPROBE_GROUP "probe"
51 
52 bool probe_event_dry_run;	/* Dry run flag */
53 struct probe_conf probe_conf = { .magic_num = DEFAULT_PROBE_MAGIC_NUM };
54 
55 #define semantic_error(msg ...) pr_err("Semantic error :" msg)
56 
e_snprintf(char * str,size_t size,const char * format,...)57 int e_snprintf(char *str, size_t size, const char *format, ...)
58 {
59 	int ret;
60 	va_list ap;
61 	va_start(ap, format);
62 	ret = vsnprintf(str, size, format, ap);
63 	va_end(ap);
64 	if (ret >= (int)size)
65 		ret = -E2BIG;
66 	return ret;
67 }
68 
69 static struct machine *host_machine;
70 
71 /* Initialize symbol maps and path of vmlinux/modules */
init_probe_symbol_maps(bool user_only)72 int init_probe_symbol_maps(bool user_only)
73 {
74 	int ret;
75 
76 	symbol_conf.sort_by_name = true;
77 	symbol_conf.allow_aliases = true;
78 	ret = symbol__init(NULL);
79 	if (ret < 0) {
80 		pr_debug("Failed to init symbol map.\n");
81 		goto out;
82 	}
83 
84 	if (host_machine || user_only)	/* already initialized */
85 		return 0;
86 
87 	if (symbol_conf.vmlinux_name)
88 		pr_debug("Use vmlinux: %s\n", symbol_conf.vmlinux_name);
89 
90 	host_machine = machine__new_host();
91 	if (!host_machine) {
92 		pr_debug("machine__new_host() failed.\n");
93 		symbol__exit();
94 		ret = -1;
95 	}
96 out:
97 	if (ret < 0)
98 		pr_warning("Failed to init vmlinux path.\n");
99 	return ret;
100 }
101 
exit_probe_symbol_maps(void)102 void exit_probe_symbol_maps(void)
103 {
104 	machine__delete(host_machine);
105 	host_machine = NULL;
106 	symbol__exit();
107 }
108 
kernel_get_ref_reloc_sym(struct map ** pmap)109 static struct ref_reloc_sym *kernel_get_ref_reloc_sym(struct map **pmap)
110 {
111 	/* kmap->ref_reloc_sym should be set if host_machine is initialized */
112 	struct kmap *kmap;
113 	struct map *map = machine__kernel_map(host_machine);
114 
115 	if (map__load(map) < 0)
116 		return NULL;
117 
118 	kmap = map__kmap(map);
119 	if (!kmap)
120 		return NULL;
121 
122 	if (pmap)
123 		*pmap = map;
124 
125 	return kmap->ref_reloc_sym;
126 }
127 
kernel_get_symbol_address_by_name(const char * name,u64 * addr,bool reloc,bool reladdr)128 static int kernel_get_symbol_address_by_name(const char *name, u64 *addr,
129 					     bool reloc, bool reladdr)
130 {
131 	struct ref_reloc_sym *reloc_sym;
132 	struct symbol *sym;
133 	struct map *map;
134 
135 	/* ref_reloc_sym is just a label. Need a special fix*/
136 	reloc_sym = kernel_get_ref_reloc_sym(&map);
137 	if (reloc_sym && strcmp(name, reloc_sym->name) == 0)
138 		*addr = (!map->reloc || reloc) ? reloc_sym->addr :
139 			reloc_sym->unrelocated_addr;
140 	else {
141 		sym = machine__find_kernel_symbol_by_name(host_machine, name, &map);
142 		if (!sym)
143 			return -ENOENT;
144 		*addr = map->unmap_ip(map, sym->start) -
145 			((reloc) ? 0 : map->reloc) -
146 			((reladdr) ? map->start : 0);
147 	}
148 	return 0;
149 }
150 
kernel_get_module_map(const char * module)151 static struct map *kernel_get_module_map(const char *module)
152 {
153 	struct maps *maps = machine__kernel_maps(host_machine);
154 	struct map *pos;
155 
156 	/* A file path -- this is an offline module */
157 	if (module && strchr(module, '/'))
158 		return dso__new_map(module);
159 
160 	if (!module) {
161 		pos = machine__kernel_map(host_machine);
162 		return map__get(pos);
163 	}
164 
165 	maps__for_each_entry(maps, pos) {
166 		/* short_name is "[module]" */
167 		if (strncmp(pos->dso->short_name + 1, module,
168 			    pos->dso->short_name_len - 2) == 0 &&
169 		    module[pos->dso->short_name_len - 2] == '\0') {
170 			return map__get(pos);
171 		}
172 	}
173 	return NULL;
174 }
175 
get_target_map(const char * target,struct nsinfo * nsi,bool user)176 struct map *get_target_map(const char *target, struct nsinfo *nsi, bool user)
177 {
178 	/* Init maps of given executable or kernel */
179 	if (user) {
180 		struct map *map;
181 
182 		map = dso__new_map(target);
183 		if (map && map->dso)
184 			map->dso->nsinfo = nsinfo__get(nsi);
185 		return map;
186 	} else {
187 		return kernel_get_module_map(target);
188 	}
189 }
190 
convert_exec_to_group(const char * exec,char ** result)191 static int convert_exec_to_group(const char *exec, char **result)
192 {
193 	char *ptr1, *ptr2, *exec_copy;
194 	char buf[64];
195 	int ret;
196 
197 	exec_copy = strdup(exec);
198 	if (!exec_copy)
199 		return -ENOMEM;
200 
201 	ptr1 = basename(exec_copy);
202 	if (!ptr1) {
203 		ret = -EINVAL;
204 		goto out;
205 	}
206 
207 	for (ptr2 = ptr1; *ptr2 != '\0'; ptr2++) {
208 		if (!isalnum(*ptr2) && *ptr2 != '_') {
209 			*ptr2 = '\0';
210 			break;
211 		}
212 	}
213 
214 	ret = e_snprintf(buf, 64, "%s_%s", PERFPROBE_GROUP, ptr1);
215 	if (ret < 0)
216 		goto out;
217 
218 	*result = strdup(buf);
219 	ret = *result ? 0 : -ENOMEM;
220 
221 out:
222 	free(exec_copy);
223 	return ret;
224 }
225 
clear_perf_probe_point(struct perf_probe_point * pp)226 static void clear_perf_probe_point(struct perf_probe_point *pp)
227 {
228 	zfree(&pp->file);
229 	zfree(&pp->function);
230 	zfree(&pp->lazy_line);
231 }
232 
clear_probe_trace_events(struct probe_trace_event * tevs,int ntevs)233 static void clear_probe_trace_events(struct probe_trace_event *tevs, int ntevs)
234 {
235 	int i;
236 
237 	for (i = 0; i < ntevs; i++)
238 		clear_probe_trace_event(tevs + i);
239 }
240 
241 static bool kprobe_blacklist__listed(unsigned long address);
kprobe_warn_out_range(const char * symbol,unsigned long address)242 static bool kprobe_warn_out_range(const char *symbol, unsigned long address)
243 {
244 	struct map *map;
245 	bool ret = false;
246 
247 	map = kernel_get_module_map(NULL);
248 	if (map) {
249 		ret = address <= map->start || map->end < address;
250 		if (ret)
251 			pr_warning("%s is out of .text, skip it.\n", symbol);
252 		map__put(map);
253 	}
254 	if (!ret && kprobe_blacklist__listed(address)) {
255 		pr_warning("%s is blacklisted function, skip it.\n", symbol);
256 		ret = true;
257 	}
258 
259 	return ret;
260 }
261 
262 /*
263  * @module can be module name of module file path. In case of path,
264  * inspect elf and find out what is actual module name.
265  * Caller has to free mod_name after using it.
266  */
find_module_name(const char * module)267 static char *find_module_name(const char *module)
268 {
269 	int fd;
270 	Elf *elf;
271 	GElf_Ehdr ehdr;
272 	GElf_Shdr shdr;
273 	Elf_Data *data;
274 	Elf_Scn *sec;
275 	char *mod_name = NULL;
276 	int name_offset;
277 
278 	fd = open(module, O_RDONLY);
279 	if (fd < 0)
280 		return NULL;
281 
282 	elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
283 	if (elf == NULL)
284 		goto elf_err;
285 
286 	if (gelf_getehdr(elf, &ehdr) == NULL)
287 		goto ret_err;
288 
289 	sec = elf_section_by_name(elf, &ehdr, &shdr,
290 			".gnu.linkonce.this_module", NULL);
291 	if (!sec)
292 		goto ret_err;
293 
294 	data = elf_getdata(sec, NULL);
295 	if (!data || !data->d_buf)
296 		goto ret_err;
297 
298 	/*
299 	 * NOTE:
300 	 * '.gnu.linkonce.this_module' section of kernel module elf directly
301 	 * maps to 'struct module' from linux/module.h. This section contains
302 	 * actual module name which will be used by kernel after loading it.
303 	 * But, we cannot use 'struct module' here since linux/module.h is not
304 	 * exposed to user-space. Offset of 'name' has remained same from long
305 	 * time, so hardcoding it here.
306 	 */
307 	if (ehdr.e_ident[EI_CLASS] == ELFCLASS32)
308 		name_offset = 12;
309 	else	/* expect ELFCLASS64 by default */
310 		name_offset = 24;
311 
312 	mod_name = strdup((char *)data->d_buf + name_offset);
313 
314 ret_err:
315 	elf_end(elf);
316 elf_err:
317 	close(fd);
318 	return mod_name;
319 }
320 
321 #ifdef HAVE_DWARF_SUPPORT
322 
kernel_get_module_dso(const char * module,struct dso ** pdso)323 static int kernel_get_module_dso(const char *module, struct dso **pdso)
324 {
325 	struct dso *dso;
326 	struct map *map;
327 	const char *vmlinux_name;
328 	int ret = 0;
329 
330 	if (module) {
331 		char module_name[128];
332 
333 		snprintf(module_name, sizeof(module_name), "[%s]", module);
334 		map = maps__find_by_name(&host_machine->kmaps, module_name);
335 		if (map) {
336 			dso = map->dso;
337 			goto found;
338 		}
339 		pr_debug("Failed to find module %s.\n", module);
340 		return -ENOENT;
341 	}
342 
343 	map = machine__kernel_map(host_machine);
344 	dso = map->dso;
345 	if (!dso->has_build_id)
346 		dso__read_running_kernel_build_id(dso, host_machine);
347 
348 	vmlinux_name = symbol_conf.vmlinux_name;
349 	dso->load_errno = 0;
350 	if (vmlinux_name)
351 		ret = dso__load_vmlinux(dso, map, vmlinux_name, false);
352 	else
353 		ret = dso__load_vmlinux_path(dso, map);
354 found:
355 	*pdso = dso;
356 	return ret;
357 }
358 
359 /*
360  * Some binaries like glibc have special symbols which are on the symbol
361  * table, but not in the debuginfo. If we can find the address of the
362  * symbol from map, we can translate the address back to the probe point.
363  */
find_alternative_probe_point(struct debuginfo * dinfo,struct perf_probe_point * pp,struct perf_probe_point * result,const char * target,struct nsinfo * nsi,bool uprobes)364 static int find_alternative_probe_point(struct debuginfo *dinfo,
365 					struct perf_probe_point *pp,
366 					struct perf_probe_point *result,
367 					const char *target, struct nsinfo *nsi,
368 					bool uprobes)
369 {
370 	struct map *map = NULL;
371 	struct symbol *sym;
372 	u64 address = 0;
373 	int ret = -ENOENT;
374 
375 	/* This can work only for function-name based one */
376 	if (!pp->function || pp->file)
377 		return -ENOTSUP;
378 
379 	map = get_target_map(target, nsi, uprobes);
380 	if (!map)
381 		return -EINVAL;
382 
383 	/* Find the address of given function */
384 	map__for_each_symbol_by_name(map, pp->function, sym) {
385 		if (uprobes) {
386 			address = sym->start;
387 			if (sym->type == STT_GNU_IFUNC)
388 				pr_warning("Warning: The probe function (%s) is a GNU indirect function.\n"
389 					   "Consider identifying the final function used at run time and set the probe directly on that.\n",
390 					   pp->function);
391 		} else
392 			address = map->unmap_ip(map, sym->start) - map->reloc;
393 		break;
394 	}
395 	if (!address) {
396 		ret = -ENOENT;
397 		goto out;
398 	}
399 	pr_debug("Symbol %s address found : %" PRIx64 "\n",
400 			pp->function, address);
401 
402 	ret = debuginfo__find_probe_point(dinfo, (unsigned long)address,
403 					  result);
404 	if (ret <= 0)
405 		ret = (!ret) ? -ENOENT : ret;
406 	else {
407 		result->offset += pp->offset;
408 		result->line += pp->line;
409 		result->retprobe = pp->retprobe;
410 		ret = 0;
411 	}
412 
413 out:
414 	map__put(map);
415 	return ret;
416 
417 }
418 
get_alternative_probe_event(struct debuginfo * dinfo,struct perf_probe_event * pev,struct perf_probe_point * tmp)419 static int get_alternative_probe_event(struct debuginfo *dinfo,
420 				       struct perf_probe_event *pev,
421 				       struct perf_probe_point *tmp)
422 {
423 	int ret;
424 
425 	memcpy(tmp, &pev->point, sizeof(*tmp));
426 	memset(&pev->point, 0, sizeof(pev->point));
427 	ret = find_alternative_probe_point(dinfo, tmp, &pev->point, pev->target,
428 					   pev->nsi, pev->uprobes);
429 	if (ret < 0)
430 		memcpy(&pev->point, tmp, sizeof(*tmp));
431 
432 	return ret;
433 }
434 
get_alternative_line_range(struct debuginfo * dinfo,struct line_range * lr,const char * target,bool user)435 static int get_alternative_line_range(struct debuginfo *dinfo,
436 				      struct line_range *lr,
437 				      const char *target, bool user)
438 {
439 	struct perf_probe_point pp = { .function = lr->function,
440 				       .file = lr->file,
441 				       .line = lr->start };
442 	struct perf_probe_point result;
443 	int ret, len = 0;
444 
445 	memset(&result, 0, sizeof(result));
446 
447 	if (lr->end != INT_MAX)
448 		len = lr->end - lr->start;
449 	ret = find_alternative_probe_point(dinfo, &pp, &result,
450 					   target, NULL, user);
451 	if (!ret) {
452 		lr->function = result.function;
453 		lr->file = result.file;
454 		lr->start = result.line;
455 		if (lr->end != INT_MAX)
456 			lr->end = lr->start + len;
457 		clear_perf_probe_point(&pp);
458 	}
459 	return ret;
460 }
461 
462 #ifdef HAVE_DEBUGINFOD_SUPPORT
open_from_debuginfod(struct dso * dso,struct nsinfo * nsi,bool silent)463 static struct debuginfo *open_from_debuginfod(struct dso *dso, struct nsinfo *nsi,
464 					      bool silent)
465 {
466 	debuginfod_client *c = debuginfod_begin();
467 	char sbuild_id[SBUILD_ID_SIZE + 1];
468 	struct debuginfo *ret = NULL;
469 	struct nscookie nsc;
470 	char *path;
471 	int fd;
472 
473 	if (!c)
474 		return NULL;
475 
476 	build_id__sprintf(&dso->bid, sbuild_id);
477 	fd = debuginfod_find_debuginfo(c, (const unsigned char *)sbuild_id,
478 					0, &path);
479 	if (fd >= 0)
480 		close(fd);
481 	debuginfod_end(c);
482 	if (fd < 0) {
483 		if (!silent)
484 			pr_debug("Failed to find debuginfo in debuginfod.\n");
485 		return NULL;
486 	}
487 	if (!silent)
488 		pr_debug("Load debuginfo from debuginfod (%s)\n", path);
489 
490 	nsinfo__mountns_enter(nsi, &nsc);
491 	ret = debuginfo__new((const char *)path);
492 	nsinfo__mountns_exit(&nsc);
493 	return ret;
494 }
495 #else
496 static inline
open_from_debuginfod(struct dso * dso __maybe_unused,struct nsinfo * nsi __maybe_unused,bool silent __maybe_unused)497 struct debuginfo *open_from_debuginfod(struct dso *dso __maybe_unused,
498 				       struct nsinfo *nsi __maybe_unused,
499 				       bool silent __maybe_unused)
500 {
501 	return NULL;
502 }
503 #endif
504 
505 /* Open new debuginfo of given module */
open_debuginfo(const char * module,struct nsinfo * nsi,bool silent)506 static struct debuginfo *open_debuginfo(const char *module, struct nsinfo *nsi,
507 					bool silent)
508 {
509 	const char *path = module;
510 	char reason[STRERR_BUFSIZE];
511 	struct debuginfo *ret = NULL;
512 	struct dso *dso = NULL;
513 	struct nscookie nsc;
514 	int err;
515 
516 	if (!module || !strchr(module, '/')) {
517 		err = kernel_get_module_dso(module, &dso);
518 		if (err < 0) {
519 			if (!dso || dso->load_errno == 0) {
520 				if (!str_error_r(-err, reason, STRERR_BUFSIZE))
521 					strcpy(reason, "(unknown)");
522 			} else
523 				dso__strerror_load(dso, reason, STRERR_BUFSIZE);
524 			if (dso)
525 				ret = open_from_debuginfod(dso, nsi, silent);
526 			if (ret)
527 				return ret;
528 			if (!silent) {
529 				if (module)
530 					pr_err("Module %s is not loaded, please specify its full path name.\n", module);
531 				else
532 					pr_err("Failed to find the path for the kernel: %s\n", reason);
533 			}
534 			return NULL;
535 		}
536 		path = dso->long_name;
537 	}
538 	nsinfo__mountns_enter(nsi, &nsc);
539 	ret = debuginfo__new(path);
540 	if (!ret && !silent) {
541 		pr_warning("The %s file has no debug information.\n", path);
542 		if (!module || !strtailcmp(path, ".ko"))
543 			pr_warning("Rebuild with CONFIG_DEBUG_INFO=y, ");
544 		else
545 			pr_warning("Rebuild with -g, ");
546 		pr_warning("or install an appropriate debuginfo package.\n");
547 	}
548 	nsinfo__mountns_exit(&nsc);
549 	return ret;
550 }
551 
552 /* For caching the last debuginfo */
553 static struct debuginfo *debuginfo_cache;
554 static char *debuginfo_cache_path;
555 
debuginfo_cache__open(const char * module,bool silent)556 static struct debuginfo *debuginfo_cache__open(const char *module, bool silent)
557 {
558 	const char *path = module;
559 
560 	/* If the module is NULL, it should be the kernel. */
561 	if (!module)
562 		path = "kernel";
563 
564 	if (debuginfo_cache_path && !strcmp(debuginfo_cache_path, path))
565 		goto out;
566 
567 	/* Copy module path */
568 	free(debuginfo_cache_path);
569 	debuginfo_cache_path = strdup(path);
570 	if (!debuginfo_cache_path) {
571 		debuginfo__delete(debuginfo_cache);
572 		debuginfo_cache = NULL;
573 		goto out;
574 	}
575 
576 	debuginfo_cache = open_debuginfo(module, NULL, silent);
577 	if (!debuginfo_cache)
578 		zfree(&debuginfo_cache_path);
579 out:
580 	return debuginfo_cache;
581 }
582 
debuginfo_cache__exit(void)583 static void debuginfo_cache__exit(void)
584 {
585 	debuginfo__delete(debuginfo_cache);
586 	debuginfo_cache = NULL;
587 	zfree(&debuginfo_cache_path);
588 }
589 
590 
get_text_start_address(const char * exec,unsigned long * address,struct nsinfo * nsi)591 static int get_text_start_address(const char *exec, unsigned long *address,
592 				  struct nsinfo *nsi)
593 {
594 	Elf *elf;
595 	GElf_Ehdr ehdr;
596 	GElf_Shdr shdr;
597 	int fd, ret = -ENOENT;
598 	struct nscookie nsc;
599 
600 	nsinfo__mountns_enter(nsi, &nsc);
601 	fd = open(exec, O_RDONLY);
602 	nsinfo__mountns_exit(&nsc);
603 	if (fd < 0)
604 		return -errno;
605 
606 	elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
607 	if (elf == NULL) {
608 		ret = -EINVAL;
609 		goto out_close;
610 	}
611 
612 	if (gelf_getehdr(elf, &ehdr) == NULL)
613 		goto out;
614 
615 	if (!elf_section_by_name(elf, &ehdr, &shdr, ".text", NULL))
616 		goto out;
617 
618 	*address = shdr.sh_addr - shdr.sh_offset;
619 	ret = 0;
620 out:
621 	elf_end(elf);
622 out_close:
623 	close(fd);
624 
625 	return ret;
626 }
627 
628 /*
629  * Convert trace point to probe point with debuginfo
630  */
find_perf_probe_point_from_dwarf(struct probe_trace_point * tp,struct perf_probe_point * pp,bool is_kprobe)631 static int find_perf_probe_point_from_dwarf(struct probe_trace_point *tp,
632 					    struct perf_probe_point *pp,
633 					    bool is_kprobe)
634 {
635 	struct debuginfo *dinfo = NULL;
636 	unsigned long stext = 0;
637 	u64 addr = tp->address;
638 	int ret = -ENOENT;
639 
640 	/* convert the address to dwarf address */
641 	if (!is_kprobe) {
642 		if (!addr) {
643 			ret = -EINVAL;
644 			goto error;
645 		}
646 		ret = get_text_start_address(tp->module, &stext, NULL);
647 		if (ret < 0)
648 			goto error;
649 		addr += stext;
650 	} else if (tp->symbol) {
651 		/* If the module is given, this returns relative address */
652 		ret = kernel_get_symbol_address_by_name(tp->symbol, &addr,
653 							false, !!tp->module);
654 		if (ret != 0)
655 			goto error;
656 		addr += tp->offset;
657 	}
658 
659 	pr_debug("try to find information at %" PRIx64 " in %s\n", addr,
660 		 tp->module ? : "kernel");
661 
662 	dinfo = debuginfo_cache__open(tp->module, verbose <= 0);
663 	if (dinfo)
664 		ret = debuginfo__find_probe_point(dinfo,
665 						 (unsigned long)addr, pp);
666 	else
667 		ret = -ENOENT;
668 
669 	if (ret > 0) {
670 		pp->retprobe = tp->retprobe;
671 		return 0;
672 	}
673 error:
674 	pr_debug("Failed to find corresponding probes from debuginfo.\n");
675 	return ret ? : -ENOENT;
676 }
677 
678 /* Adjust symbol name and address */
post_process_probe_trace_point(struct probe_trace_point * tp,struct map * map,unsigned long offs)679 static int post_process_probe_trace_point(struct probe_trace_point *tp,
680 					   struct map *map, unsigned long offs)
681 {
682 	struct symbol *sym;
683 	u64 addr = tp->address - offs;
684 
685 	sym = map__find_symbol(map, addr);
686 	if (!sym)
687 		return -ENOENT;
688 
689 	if (strcmp(sym->name, tp->symbol)) {
690 		/* If we have no realname, use symbol for it */
691 		if (!tp->realname)
692 			tp->realname = tp->symbol;
693 		else
694 			free(tp->symbol);
695 		tp->symbol = strdup(sym->name);
696 		if (!tp->symbol)
697 			return -ENOMEM;
698 	}
699 	tp->offset = addr - sym->start;
700 	tp->address -= offs;
701 
702 	return 0;
703 }
704 
705 /*
706  * Rename DWARF symbols to ELF symbols -- gcc sometimes optimizes functions
707  * and generate new symbols with suffixes such as .constprop.N or .isra.N
708  * etc. Since those symbols are not recorded in DWARF, we have to find
709  * correct generated symbols from offline ELF binary.
710  * For online kernel or uprobes we don't need this because those are
711  * rebased on _text, or already a section relative address.
712  */
713 static int
post_process_offline_probe_trace_events(struct probe_trace_event * tevs,int ntevs,const char * pathname)714 post_process_offline_probe_trace_events(struct probe_trace_event *tevs,
715 					int ntevs, const char *pathname)
716 {
717 	struct map *map;
718 	unsigned long stext = 0;
719 	int i, ret = 0;
720 
721 	/* Prepare a map for offline binary */
722 	map = dso__new_map(pathname);
723 	if (!map || get_text_start_address(pathname, &stext, NULL) < 0) {
724 		pr_warning("Failed to get ELF symbols for %s\n", pathname);
725 		return -EINVAL;
726 	}
727 
728 	for (i = 0; i < ntevs; i++) {
729 		ret = post_process_probe_trace_point(&tevs[i].point,
730 						     map, stext);
731 		if (ret < 0)
732 			break;
733 	}
734 	map__put(map);
735 
736 	return ret;
737 }
738 
add_exec_to_probe_trace_events(struct probe_trace_event * tevs,int ntevs,const char * exec,struct nsinfo * nsi)739 static int add_exec_to_probe_trace_events(struct probe_trace_event *tevs,
740 					  int ntevs, const char *exec,
741 					  struct nsinfo *nsi)
742 {
743 	int i, ret = 0;
744 	unsigned long stext = 0;
745 
746 	if (!exec)
747 		return 0;
748 
749 	ret = get_text_start_address(exec, &stext, nsi);
750 	if (ret < 0)
751 		return ret;
752 
753 	for (i = 0; i < ntevs && ret >= 0; i++) {
754 		/* point.address is the address of point.symbol + point.offset */
755 		tevs[i].point.address -= stext;
756 		tevs[i].point.module = strdup(exec);
757 		if (!tevs[i].point.module) {
758 			ret = -ENOMEM;
759 			break;
760 		}
761 		tevs[i].uprobes = true;
762 	}
763 
764 	return ret;
765 }
766 
767 static int
post_process_module_probe_trace_events(struct probe_trace_event * tevs,int ntevs,const char * module,struct debuginfo * dinfo)768 post_process_module_probe_trace_events(struct probe_trace_event *tevs,
769 				       int ntevs, const char *module,
770 				       struct debuginfo *dinfo)
771 {
772 	Dwarf_Addr text_offs = 0;
773 	int i, ret = 0;
774 	char *mod_name = NULL;
775 	struct map *map;
776 
777 	if (!module)
778 		return 0;
779 
780 	map = get_target_map(module, NULL, false);
781 	if (!map || debuginfo__get_text_offset(dinfo, &text_offs, true) < 0) {
782 		pr_warning("Failed to get ELF symbols for %s\n", module);
783 		return -EINVAL;
784 	}
785 
786 	mod_name = find_module_name(module);
787 	for (i = 0; i < ntevs; i++) {
788 		ret = post_process_probe_trace_point(&tevs[i].point,
789 						map, (unsigned long)text_offs);
790 		if (ret < 0)
791 			break;
792 		tevs[i].point.module =
793 			strdup(mod_name ? mod_name : module);
794 		if (!tevs[i].point.module) {
795 			ret = -ENOMEM;
796 			break;
797 		}
798 	}
799 
800 	free(mod_name);
801 	map__put(map);
802 
803 	return ret;
804 }
805 
806 static int
post_process_kernel_probe_trace_events(struct probe_trace_event * tevs,int ntevs)807 post_process_kernel_probe_trace_events(struct probe_trace_event *tevs,
808 				       int ntevs)
809 {
810 	struct ref_reloc_sym *reloc_sym;
811 	struct map *map;
812 	char *tmp;
813 	int i, skipped = 0;
814 
815 	/* Skip post process if the target is an offline kernel */
816 	if (symbol_conf.ignore_vmlinux_buildid)
817 		return post_process_offline_probe_trace_events(tevs, ntevs,
818 						symbol_conf.vmlinux_name);
819 
820 	reloc_sym = kernel_get_ref_reloc_sym(&map);
821 	if (!reloc_sym) {
822 		pr_warning("Relocated base symbol is not found!\n");
823 		return -EINVAL;
824 	}
825 
826 	for (i = 0; i < ntevs; i++) {
827 		if (!tevs[i].point.address)
828 			continue;
829 		if (tevs[i].point.retprobe && !kretprobe_offset_is_supported())
830 			continue;
831 		/*
832 		 * If we found a wrong one, mark it by NULL symbol.
833 		 * Since addresses in debuginfo is same as objdump, we need
834 		 * to convert it to addresses on memory.
835 		 */
836 		if (kprobe_warn_out_range(tevs[i].point.symbol,
837 			map__objdump_2mem(map, tevs[i].point.address))) {
838 			tmp = NULL;
839 			skipped++;
840 		} else {
841 			tmp = strdup(reloc_sym->name);
842 			if (!tmp)
843 				return -ENOMEM;
844 		}
845 		/* If we have no realname, use symbol for it */
846 		if (!tevs[i].point.realname)
847 			tevs[i].point.realname = tevs[i].point.symbol;
848 		else
849 			free(tevs[i].point.symbol);
850 		tevs[i].point.symbol = tmp;
851 		tevs[i].point.offset = tevs[i].point.address -
852 			(map->reloc ? reloc_sym->unrelocated_addr :
853 				      reloc_sym->addr);
854 	}
855 	return skipped;
856 }
857 
858 void __weak
arch__post_process_probe_trace_events(struct perf_probe_event * pev __maybe_unused,int ntevs __maybe_unused)859 arch__post_process_probe_trace_events(struct perf_probe_event *pev __maybe_unused,
860 				      int ntevs __maybe_unused)
861 {
862 }
863 
864 /* Post processing the probe events */
post_process_probe_trace_events(struct perf_probe_event * pev,struct probe_trace_event * tevs,int ntevs,const char * module,bool uprobe,struct debuginfo * dinfo)865 static int post_process_probe_trace_events(struct perf_probe_event *pev,
866 					   struct probe_trace_event *tevs,
867 					   int ntevs, const char *module,
868 					   bool uprobe, struct debuginfo *dinfo)
869 {
870 	int ret;
871 
872 	if (uprobe)
873 		ret = add_exec_to_probe_trace_events(tevs, ntevs, module,
874 						     pev->nsi);
875 	else if (module)
876 		/* Currently ref_reloc_sym based probe is not for drivers */
877 		ret = post_process_module_probe_trace_events(tevs, ntevs,
878 							     module, dinfo);
879 	else
880 		ret = post_process_kernel_probe_trace_events(tevs, ntevs);
881 
882 	if (ret >= 0)
883 		arch__post_process_probe_trace_events(pev, ntevs);
884 
885 	return ret;
886 }
887 
888 /* Try to find perf_probe_event with debuginfo */
try_to_find_probe_trace_events(struct perf_probe_event * pev,struct probe_trace_event ** tevs)889 static int try_to_find_probe_trace_events(struct perf_probe_event *pev,
890 					  struct probe_trace_event **tevs)
891 {
892 	bool need_dwarf = perf_probe_event_need_dwarf(pev);
893 	struct perf_probe_point tmp;
894 	struct debuginfo *dinfo;
895 	int ntevs, ret = 0;
896 
897 	/* Workaround for gcc #98776 issue.
898 	 * Perf failed to add kretprobe event with debuginfo of vmlinux which is
899 	 * compiled by gcc with -fpatchable-function-entry option enabled. The
900 	 * same issue with kernel module. The retprobe doesn`t need debuginfo.
901 	 * This workaround solution use map to query the probe function address
902 	 * for retprobe event.
903 	 */
904 	if (pev->point.retprobe)
905 		return 0;
906 
907 	dinfo = open_debuginfo(pev->target, pev->nsi, !need_dwarf);
908 	if (!dinfo) {
909 		if (need_dwarf)
910 			return -ENOENT;
911 		pr_debug("Could not open debuginfo. Try to use symbols.\n");
912 		return 0;
913 	}
914 
915 	pr_debug("Try to find probe point from debuginfo.\n");
916 	/* Searching trace events corresponding to a probe event */
917 	ntevs = debuginfo__find_trace_events(dinfo, pev, tevs);
918 
919 	if (ntevs == 0)	{  /* Not found, retry with an alternative */
920 		ret = get_alternative_probe_event(dinfo, pev, &tmp);
921 		if (!ret) {
922 			ntevs = debuginfo__find_trace_events(dinfo, pev, tevs);
923 			/*
924 			 * Write back to the original probe_event for
925 			 * setting appropriate (user given) event name
926 			 */
927 			clear_perf_probe_point(&pev->point);
928 			memcpy(&pev->point, &tmp, sizeof(tmp));
929 		}
930 	}
931 
932 	if (ntevs > 0) {	/* Succeeded to find trace events */
933 		pr_debug("Found %d probe_trace_events.\n", ntevs);
934 		ret = post_process_probe_trace_events(pev, *tevs, ntevs,
935 					pev->target, pev->uprobes, dinfo);
936 		if (ret < 0 || ret == ntevs) {
937 			pr_debug("Post processing failed or all events are skipped. (%d)\n", ret);
938 			clear_probe_trace_events(*tevs, ntevs);
939 			zfree(tevs);
940 			ntevs = 0;
941 		}
942 	}
943 
944 	debuginfo__delete(dinfo);
945 
946 	if (ntevs == 0)	{	/* No error but failed to find probe point. */
947 		pr_warning("Probe point '%s' not found.\n",
948 			   synthesize_perf_probe_point(&pev->point));
949 		return -ENOENT;
950 	} else if (ntevs < 0) {
951 		/* Error path : ntevs < 0 */
952 		pr_debug("An error occurred in debuginfo analysis (%d).\n", ntevs);
953 		if (ntevs == -EBADF)
954 			pr_warning("Warning: No dwarf info found in the vmlinux - "
955 				"please rebuild kernel with CONFIG_DEBUG_INFO=y.\n");
956 		if (!need_dwarf) {
957 			pr_debug("Trying to use symbols.\n");
958 			return 0;
959 		}
960 	}
961 	return ntevs;
962 }
963 
964 #define LINEBUF_SIZE 256
965 #define NR_ADDITIONAL_LINES 2
966 
__show_one_line(FILE * fp,int l,bool skip,bool show_num)967 static int __show_one_line(FILE *fp, int l, bool skip, bool show_num)
968 {
969 	char buf[LINEBUF_SIZE], sbuf[STRERR_BUFSIZE];
970 	const char *color = show_num ? "" : PERF_COLOR_BLUE;
971 	const char *prefix = NULL;
972 
973 	do {
974 		if (fgets(buf, LINEBUF_SIZE, fp) == NULL)
975 			goto error;
976 		if (skip)
977 			continue;
978 		if (!prefix) {
979 			prefix = show_num ? "%7d  " : "         ";
980 			color_fprintf(stdout, color, prefix, l);
981 		}
982 		color_fprintf(stdout, color, "%s", buf);
983 
984 	} while (strchr(buf, '\n') == NULL);
985 
986 	return 1;
987 error:
988 	if (ferror(fp)) {
989 		pr_warning("File read error: %s\n",
990 			   str_error_r(errno, sbuf, sizeof(sbuf)));
991 		return -1;
992 	}
993 	return 0;
994 }
995 
_show_one_line(FILE * fp,int l,bool skip,bool show_num)996 static int _show_one_line(FILE *fp, int l, bool skip, bool show_num)
997 {
998 	int rv = __show_one_line(fp, l, skip, show_num);
999 	if (rv == 0) {
1000 		pr_warning("Source file is shorter than expected.\n");
1001 		rv = -1;
1002 	}
1003 	return rv;
1004 }
1005 
1006 #define show_one_line_with_num(f,l)	_show_one_line(f,l,false,true)
1007 #define show_one_line(f,l)		_show_one_line(f,l,false,false)
1008 #define skip_one_line(f,l)		_show_one_line(f,l,true,false)
1009 #define show_one_line_or_eof(f,l)	__show_one_line(f,l,false,false)
1010 
1011 /*
1012  * Show line-range always requires debuginfo to find source file and
1013  * line number.
1014  */
__show_line_range(struct line_range * lr,const char * module,bool user)1015 static int __show_line_range(struct line_range *lr, const char *module,
1016 			     bool user)
1017 {
1018 	struct build_id bid;
1019 	int l = 1;
1020 	struct int_node *ln;
1021 	struct debuginfo *dinfo;
1022 	FILE *fp;
1023 	int ret;
1024 	char *tmp;
1025 	char sbuf[STRERR_BUFSIZE];
1026 	char sbuild_id[SBUILD_ID_SIZE] = "";
1027 
1028 	/* Search a line range */
1029 	dinfo = open_debuginfo(module, NULL, false);
1030 	if (!dinfo)
1031 		return -ENOENT;
1032 
1033 	ret = debuginfo__find_line_range(dinfo, lr);
1034 	if (!ret) {	/* Not found, retry with an alternative */
1035 		ret = get_alternative_line_range(dinfo, lr, module, user);
1036 		if (!ret)
1037 			ret = debuginfo__find_line_range(dinfo, lr);
1038 	}
1039 	if (dinfo->build_id) {
1040 		build_id__init(&bid, dinfo->build_id, BUILD_ID_SIZE);
1041 		build_id__sprintf(&bid, sbuild_id);
1042 	}
1043 	debuginfo__delete(dinfo);
1044 	if (ret == 0 || ret == -ENOENT) {
1045 		pr_warning("Specified source line is not found.\n");
1046 		return -ENOENT;
1047 	} else if (ret < 0) {
1048 		pr_warning("Debuginfo analysis failed.\n");
1049 		return ret;
1050 	}
1051 
1052 	/* Convert source file path */
1053 	tmp = lr->path;
1054 	ret = find_source_path(tmp, sbuild_id, lr->comp_dir, &lr->path);
1055 
1056 	/* Free old path when new path is assigned */
1057 	if (tmp != lr->path)
1058 		free(tmp);
1059 
1060 	if (ret < 0) {
1061 		pr_warning("Failed to find source file path.\n");
1062 		return ret;
1063 	}
1064 
1065 	setup_pager();
1066 
1067 	if (lr->function)
1068 		fprintf(stdout, "<%s@%s:%d>\n", lr->function, lr->path,
1069 			lr->start - lr->offset);
1070 	else
1071 		fprintf(stdout, "<%s:%d>\n", lr->path, lr->start);
1072 
1073 	fp = fopen(lr->path, "r");
1074 	if (fp == NULL) {
1075 		pr_warning("Failed to open %s: %s\n", lr->path,
1076 			   str_error_r(errno, sbuf, sizeof(sbuf)));
1077 		return -errno;
1078 	}
1079 	/* Skip to starting line number */
1080 	while (l < lr->start) {
1081 		ret = skip_one_line(fp, l++);
1082 		if (ret < 0)
1083 			goto end;
1084 	}
1085 
1086 	intlist__for_each_entry(ln, lr->line_list) {
1087 		for (; ln->i > (unsigned long)l; l++) {
1088 			ret = show_one_line(fp, l - lr->offset);
1089 			if (ret < 0)
1090 				goto end;
1091 		}
1092 		ret = show_one_line_with_num(fp, l++ - lr->offset);
1093 		if (ret < 0)
1094 			goto end;
1095 	}
1096 
1097 	if (lr->end == INT_MAX)
1098 		lr->end = l + NR_ADDITIONAL_LINES;
1099 	while (l <= lr->end) {
1100 		ret = show_one_line_or_eof(fp, l++ - lr->offset);
1101 		if (ret <= 0)
1102 			break;
1103 	}
1104 end:
1105 	fclose(fp);
1106 	return ret;
1107 }
1108 
show_line_range(struct line_range * lr,const char * module,struct nsinfo * nsi,bool user)1109 int show_line_range(struct line_range *lr, const char *module,
1110 		    struct nsinfo *nsi, bool user)
1111 {
1112 	int ret;
1113 	struct nscookie nsc;
1114 
1115 	ret = init_probe_symbol_maps(user);
1116 	if (ret < 0)
1117 		return ret;
1118 	nsinfo__mountns_enter(nsi, &nsc);
1119 	ret = __show_line_range(lr, module, user);
1120 	nsinfo__mountns_exit(&nsc);
1121 	exit_probe_symbol_maps();
1122 
1123 	return ret;
1124 }
1125 
show_available_vars_at(struct debuginfo * dinfo,struct perf_probe_event * pev,struct strfilter * _filter)1126 static int show_available_vars_at(struct debuginfo *dinfo,
1127 				  struct perf_probe_event *pev,
1128 				  struct strfilter *_filter)
1129 {
1130 	char *buf;
1131 	int ret, i, nvars;
1132 	struct str_node *node;
1133 	struct variable_list *vls = NULL, *vl;
1134 	struct perf_probe_point tmp;
1135 	const char *var;
1136 
1137 	buf = synthesize_perf_probe_point(&pev->point);
1138 	if (!buf)
1139 		return -EINVAL;
1140 	pr_debug("Searching variables at %s\n", buf);
1141 
1142 	ret = debuginfo__find_available_vars_at(dinfo, pev, &vls);
1143 	if (!ret) {  /* Not found, retry with an alternative */
1144 		ret = get_alternative_probe_event(dinfo, pev, &tmp);
1145 		if (!ret) {
1146 			ret = debuginfo__find_available_vars_at(dinfo, pev,
1147 								&vls);
1148 			/* Release the old probe_point */
1149 			clear_perf_probe_point(&tmp);
1150 		}
1151 	}
1152 	if (ret <= 0) {
1153 		if (ret == 0 || ret == -ENOENT) {
1154 			pr_err("Failed to find the address of %s\n", buf);
1155 			ret = -ENOENT;
1156 		} else
1157 			pr_warning("Debuginfo analysis failed.\n");
1158 		goto end;
1159 	}
1160 
1161 	/* Some variables are found */
1162 	fprintf(stdout, "Available variables at %s\n", buf);
1163 	for (i = 0; i < ret; i++) {
1164 		vl = &vls[i];
1165 		/*
1166 		 * A probe point might be converted to
1167 		 * several trace points.
1168 		 */
1169 		fprintf(stdout, "\t@<%s+%lu>\n", vl->point.symbol,
1170 			vl->point.offset);
1171 		zfree(&vl->point.symbol);
1172 		nvars = 0;
1173 		if (vl->vars) {
1174 			strlist__for_each_entry(node, vl->vars) {
1175 				var = strchr(node->s, '\t') + 1;
1176 				if (strfilter__compare(_filter, var)) {
1177 					fprintf(stdout, "\t\t%s\n", node->s);
1178 					nvars++;
1179 				}
1180 			}
1181 			strlist__delete(vl->vars);
1182 		}
1183 		if (nvars == 0)
1184 			fprintf(stdout, "\t\t(No matched variables)\n");
1185 	}
1186 	free(vls);
1187 end:
1188 	free(buf);
1189 	return ret;
1190 }
1191 
1192 /* Show available variables on given probe point */
show_available_vars(struct perf_probe_event * pevs,int npevs,struct strfilter * _filter)1193 int show_available_vars(struct perf_probe_event *pevs, int npevs,
1194 			struct strfilter *_filter)
1195 {
1196 	int i, ret = 0;
1197 	struct debuginfo *dinfo;
1198 
1199 	ret = init_probe_symbol_maps(pevs->uprobes);
1200 	if (ret < 0)
1201 		return ret;
1202 
1203 	dinfo = open_debuginfo(pevs->target, pevs->nsi, false);
1204 	if (!dinfo) {
1205 		ret = -ENOENT;
1206 		goto out;
1207 	}
1208 
1209 	setup_pager();
1210 
1211 	for (i = 0; i < npevs && ret >= 0; i++)
1212 		ret = show_available_vars_at(dinfo, &pevs[i], _filter);
1213 
1214 	debuginfo__delete(dinfo);
1215 out:
1216 	exit_probe_symbol_maps();
1217 	return ret;
1218 }
1219 
1220 #else	/* !HAVE_DWARF_SUPPORT */
1221 
debuginfo_cache__exit(void)1222 static void debuginfo_cache__exit(void)
1223 {
1224 }
1225 
1226 static int
find_perf_probe_point_from_dwarf(struct probe_trace_point * tp __maybe_unused,struct perf_probe_point * pp __maybe_unused,bool is_kprobe __maybe_unused)1227 find_perf_probe_point_from_dwarf(struct probe_trace_point *tp __maybe_unused,
1228 				 struct perf_probe_point *pp __maybe_unused,
1229 				 bool is_kprobe __maybe_unused)
1230 {
1231 	return -ENOSYS;
1232 }
1233 
try_to_find_probe_trace_events(struct perf_probe_event * pev,struct probe_trace_event ** tevs __maybe_unused)1234 static int try_to_find_probe_trace_events(struct perf_probe_event *pev,
1235 				struct probe_trace_event **tevs __maybe_unused)
1236 {
1237 	if (perf_probe_event_need_dwarf(pev)) {
1238 		pr_warning("Debuginfo-analysis is not supported.\n");
1239 		return -ENOSYS;
1240 	}
1241 
1242 	return 0;
1243 }
1244 
show_line_range(struct line_range * lr __maybe_unused,const char * module __maybe_unused,struct nsinfo * nsi __maybe_unused,bool user __maybe_unused)1245 int show_line_range(struct line_range *lr __maybe_unused,
1246 		    const char *module __maybe_unused,
1247 		    struct nsinfo *nsi __maybe_unused,
1248 		    bool user __maybe_unused)
1249 {
1250 	pr_warning("Debuginfo-analysis is not supported.\n");
1251 	return -ENOSYS;
1252 }
1253 
show_available_vars(struct perf_probe_event * pevs __maybe_unused,int npevs __maybe_unused,struct strfilter * filter __maybe_unused)1254 int show_available_vars(struct perf_probe_event *pevs __maybe_unused,
1255 			int npevs __maybe_unused,
1256 			struct strfilter *filter __maybe_unused)
1257 {
1258 	pr_warning("Debuginfo-analysis is not supported.\n");
1259 	return -ENOSYS;
1260 }
1261 #endif
1262 
line_range__clear(struct line_range * lr)1263 void line_range__clear(struct line_range *lr)
1264 {
1265 	zfree(&lr->function);
1266 	zfree(&lr->file);
1267 	zfree(&lr->path);
1268 	zfree(&lr->comp_dir);
1269 	intlist__delete(lr->line_list);
1270 }
1271 
line_range__init(struct line_range * lr)1272 int line_range__init(struct line_range *lr)
1273 {
1274 	memset(lr, 0, sizeof(*lr));
1275 	lr->line_list = intlist__new(NULL);
1276 	if (!lr->line_list)
1277 		return -ENOMEM;
1278 	else
1279 		return 0;
1280 }
1281 
parse_line_num(char ** ptr,int * val,const char * what)1282 static int parse_line_num(char **ptr, int *val, const char *what)
1283 {
1284 	const char *start = *ptr;
1285 
1286 	errno = 0;
1287 	*val = strtol(*ptr, ptr, 0);
1288 	if (errno || *ptr == start) {
1289 		semantic_error("'%s' is not a valid number.\n", what);
1290 		return -EINVAL;
1291 	}
1292 	return 0;
1293 }
1294 
1295 /* Check the name is good for event, group or function */
is_c_func_name(const char * name)1296 static bool is_c_func_name(const char *name)
1297 {
1298 	if (!isalpha(*name) && *name != '_')
1299 		return false;
1300 	while (*++name != '\0') {
1301 		if (!isalpha(*name) && !isdigit(*name) && *name != '_')
1302 			return false;
1303 	}
1304 	return true;
1305 }
1306 
1307 /*
1308  * Stuff 'lr' according to the line range described by 'arg'.
1309  * The line range syntax is described by:
1310  *
1311  *         SRC[:SLN[+NUM|-ELN]]
1312  *         FNC[@SRC][:SLN[+NUM|-ELN]]
1313  */
parse_line_range_desc(const char * arg,struct line_range * lr)1314 int parse_line_range_desc(const char *arg, struct line_range *lr)
1315 {
1316 	char *range, *file, *name = strdup(arg);
1317 	int err;
1318 
1319 	if (!name)
1320 		return -ENOMEM;
1321 
1322 	lr->start = 0;
1323 	lr->end = INT_MAX;
1324 
1325 	range = strchr(name, ':');
1326 	if (range) {
1327 		*range++ = '\0';
1328 
1329 		err = parse_line_num(&range, &lr->start, "start line");
1330 		if (err)
1331 			goto err;
1332 
1333 		if (*range == '+' || *range == '-') {
1334 			const char c = *range++;
1335 
1336 			err = parse_line_num(&range, &lr->end, "end line");
1337 			if (err)
1338 				goto err;
1339 
1340 			if (c == '+') {
1341 				lr->end += lr->start;
1342 				/*
1343 				 * Adjust the number of lines here.
1344 				 * If the number of lines == 1, the
1345 				 * the end of line should be equal to
1346 				 * the start of line.
1347 				 */
1348 				lr->end--;
1349 			}
1350 		}
1351 
1352 		pr_debug("Line range is %d to %d\n", lr->start, lr->end);
1353 
1354 		err = -EINVAL;
1355 		if (lr->start > lr->end) {
1356 			semantic_error("Start line must be smaller"
1357 				       " than end line.\n");
1358 			goto err;
1359 		}
1360 		if (*range != '\0') {
1361 			semantic_error("Tailing with invalid str '%s'.\n", range);
1362 			goto err;
1363 		}
1364 	}
1365 
1366 	file = strchr(name, '@');
1367 	if (file) {
1368 		*file = '\0';
1369 		lr->file = strdup(++file);
1370 		if (lr->file == NULL) {
1371 			err = -ENOMEM;
1372 			goto err;
1373 		}
1374 		lr->function = name;
1375 	} else if (strchr(name, '/') || strchr(name, '.'))
1376 		lr->file = name;
1377 	else if (is_c_func_name(name))/* We reuse it for checking funcname */
1378 		lr->function = name;
1379 	else {	/* Invalid name */
1380 		semantic_error("'%s' is not a valid function name.\n", name);
1381 		err = -EINVAL;
1382 		goto err;
1383 	}
1384 
1385 	return 0;
1386 err:
1387 	free(name);
1388 	return err;
1389 }
1390 
parse_perf_probe_event_name(char ** arg,struct perf_probe_event * pev)1391 static int parse_perf_probe_event_name(char **arg, struct perf_probe_event *pev)
1392 {
1393 	char *ptr;
1394 
1395 	ptr = strpbrk_esc(*arg, ":");
1396 	if (ptr) {
1397 		*ptr = '\0';
1398 		if (!pev->sdt && !is_c_func_name(*arg))
1399 			goto ng_name;
1400 		pev->group = strdup_esc(*arg);
1401 		if (!pev->group)
1402 			return -ENOMEM;
1403 		*arg = ptr + 1;
1404 	} else
1405 		pev->group = NULL;
1406 
1407 	pev->event = strdup_esc(*arg);
1408 	if (pev->event == NULL)
1409 		return -ENOMEM;
1410 
1411 	if (!pev->sdt && !is_c_func_name(pev->event)) {
1412 		zfree(&pev->event);
1413 ng_name:
1414 		zfree(&pev->group);
1415 		semantic_error("%s is bad for event name -it must "
1416 			       "follow C symbol-naming rule.\n", *arg);
1417 		return -EINVAL;
1418 	}
1419 	return 0;
1420 }
1421 
1422 /* Parse probepoint definition. */
parse_perf_probe_point(char * arg,struct perf_probe_event * pev)1423 static int parse_perf_probe_point(char *arg, struct perf_probe_event *pev)
1424 {
1425 	struct perf_probe_point *pp = &pev->point;
1426 	char *ptr, *tmp;
1427 	char c, nc = 0;
1428 	bool file_spec = false;
1429 	int ret;
1430 
1431 	/*
1432 	 * <Syntax>
1433 	 * perf probe [GRP:][EVENT=]SRC[:LN|;PTN]
1434 	 * perf probe [GRP:][EVENT=]FUNC[@SRC][+OFFS|%return|:LN|;PAT]
1435 	 * perf probe %[GRP:]SDT_EVENT
1436 	 */
1437 	if (!arg)
1438 		return -EINVAL;
1439 
1440 	if (is_sdt_event(arg)) {
1441 		pev->sdt = true;
1442 		if (arg[0] == '%')
1443 			arg++;
1444 	}
1445 
1446 	ptr = strpbrk_esc(arg, ";=@+%");
1447 	if (pev->sdt) {
1448 		if (ptr) {
1449 			if (*ptr != '@') {
1450 				semantic_error("%s must be an SDT name.\n",
1451 					       arg);
1452 				return -EINVAL;
1453 			}
1454 			/* This must be a target file name or build id */
1455 			tmp = build_id_cache__complement(ptr + 1);
1456 			if (tmp) {
1457 				pev->target = build_id_cache__origname(tmp);
1458 				free(tmp);
1459 			} else
1460 				pev->target = strdup_esc(ptr + 1);
1461 			if (!pev->target)
1462 				return -ENOMEM;
1463 			*ptr = '\0';
1464 		}
1465 		ret = parse_perf_probe_event_name(&arg, pev);
1466 		if (ret == 0) {
1467 			if (asprintf(&pev->point.function, "%%%s", pev->event) < 0)
1468 				ret = -errno;
1469 		}
1470 		return ret;
1471 	}
1472 
1473 	if (ptr && *ptr == '=') {	/* Event name */
1474 		*ptr = '\0';
1475 		tmp = ptr + 1;
1476 		ret = parse_perf_probe_event_name(&arg, pev);
1477 		if (ret < 0)
1478 			return ret;
1479 
1480 		arg = tmp;
1481 	}
1482 
1483 	/*
1484 	 * Check arg is function or file name and copy it.
1485 	 *
1486 	 * We consider arg to be a file spec if and only if it satisfies
1487 	 * all of the below criteria::
1488 	 * - it does not include any of "+@%",
1489 	 * - it includes one of ":;", and
1490 	 * - it has a period '.' in the name.
1491 	 *
1492 	 * Otherwise, we consider arg to be a function specification.
1493 	 */
1494 	if (!strpbrk_esc(arg, "+@%")) {
1495 		ptr = strpbrk_esc(arg, ";:");
1496 		/* This is a file spec if it includes a '.' before ; or : */
1497 		if (ptr && memchr(arg, '.', ptr - arg))
1498 			file_spec = true;
1499 	}
1500 
1501 	ptr = strpbrk_esc(arg, ";:+@%");
1502 	if (ptr) {
1503 		nc = *ptr;
1504 		*ptr++ = '\0';
1505 	}
1506 
1507 	if (arg[0] == '\0')
1508 		tmp = NULL;
1509 	else {
1510 		tmp = strdup_esc(arg);
1511 		if (tmp == NULL)
1512 			return -ENOMEM;
1513 	}
1514 
1515 	if (file_spec)
1516 		pp->file = tmp;
1517 	else {
1518 		pp->function = tmp;
1519 
1520 		/*
1521 		 * Keep pp->function even if this is absolute address,
1522 		 * so it can mark whether abs_address is valid.
1523 		 * Which make 'perf probe lib.bin 0x0' possible.
1524 		 *
1525 		 * Note that checking length of tmp is not needed
1526 		 * because when we access tmp[1] we know tmp[0] is '0',
1527 		 * so tmp[1] should always valid (but could be '\0').
1528 		 */
1529 		if (tmp && !strncmp(tmp, "0x", 2)) {
1530 			pp->abs_address = strtoul(pp->function, &tmp, 0);
1531 			if (*tmp != '\0') {
1532 				semantic_error("Invalid absolute address.\n");
1533 				return -EINVAL;
1534 			}
1535 		}
1536 	}
1537 
1538 	/* Parse other options */
1539 	while (ptr) {
1540 		arg = ptr;
1541 		c = nc;
1542 		if (c == ';') {	/* Lazy pattern must be the last part */
1543 			pp->lazy_line = strdup(arg); /* let leave escapes */
1544 			if (pp->lazy_line == NULL)
1545 				return -ENOMEM;
1546 			break;
1547 		}
1548 		ptr = strpbrk_esc(arg, ";:+@%");
1549 		if (ptr) {
1550 			nc = *ptr;
1551 			*ptr++ = '\0';
1552 		}
1553 		switch (c) {
1554 		case ':':	/* Line number */
1555 			pp->line = strtoul(arg, &tmp, 0);
1556 			if (*tmp != '\0') {
1557 				semantic_error("There is non-digit char"
1558 					       " in line number.\n");
1559 				return -EINVAL;
1560 			}
1561 			break;
1562 		case '+':	/* Byte offset from a symbol */
1563 			pp->offset = strtoul(arg, &tmp, 0);
1564 			if (*tmp != '\0') {
1565 				semantic_error("There is non-digit character"
1566 						" in offset.\n");
1567 				return -EINVAL;
1568 			}
1569 			break;
1570 		case '@':	/* File name */
1571 			if (pp->file) {
1572 				semantic_error("SRC@SRC is not allowed.\n");
1573 				return -EINVAL;
1574 			}
1575 			pp->file = strdup_esc(arg);
1576 			if (pp->file == NULL)
1577 				return -ENOMEM;
1578 			break;
1579 		case '%':	/* Probe places */
1580 			if (strcmp(arg, "return") == 0) {
1581 				pp->retprobe = 1;
1582 			} else {	/* Others not supported yet */
1583 				semantic_error("%%%s is not supported.\n", arg);
1584 				return -ENOTSUP;
1585 			}
1586 			break;
1587 		default:	/* Buggy case */
1588 			pr_err("This program has a bug at %s:%d.\n",
1589 				__FILE__, __LINE__);
1590 			return -ENOTSUP;
1591 			break;
1592 		}
1593 	}
1594 
1595 	/* Exclusion check */
1596 	if (pp->lazy_line && pp->line) {
1597 		semantic_error("Lazy pattern can't be used with"
1598 			       " line number.\n");
1599 		return -EINVAL;
1600 	}
1601 
1602 	if (pp->lazy_line && pp->offset) {
1603 		semantic_error("Lazy pattern can't be used with offset.\n");
1604 		return -EINVAL;
1605 	}
1606 
1607 	if (pp->line && pp->offset) {
1608 		semantic_error("Offset can't be used with line number.\n");
1609 		return -EINVAL;
1610 	}
1611 
1612 	if (!pp->line && !pp->lazy_line && pp->file && !pp->function) {
1613 		semantic_error("File always requires line number or "
1614 			       "lazy pattern.\n");
1615 		return -EINVAL;
1616 	}
1617 
1618 	if (pp->offset && !pp->function) {
1619 		semantic_error("Offset requires an entry function.\n");
1620 		return -EINVAL;
1621 	}
1622 
1623 	if ((pp->offset || pp->line || pp->lazy_line) && pp->retprobe) {
1624 		semantic_error("Offset/Line/Lazy pattern can't be used with "
1625 			       "return probe.\n");
1626 		return -EINVAL;
1627 	}
1628 
1629 	pr_debug("symbol:%s file:%s line:%d offset:%lu return:%d lazy:%s\n",
1630 		 pp->function, pp->file, pp->line, pp->offset, pp->retprobe,
1631 		 pp->lazy_line);
1632 	return 0;
1633 }
1634 
1635 /* Parse perf-probe event argument */
parse_perf_probe_arg(char * str,struct perf_probe_arg * arg)1636 static int parse_perf_probe_arg(char *str, struct perf_probe_arg *arg)
1637 {
1638 	char *tmp, *goodname;
1639 	struct perf_probe_arg_field **fieldp;
1640 
1641 	pr_debug("parsing arg: %s into ", str);
1642 
1643 	tmp = strchr(str, '=');
1644 	if (tmp) {
1645 		arg->name = strndup(str, tmp - str);
1646 		if (arg->name == NULL)
1647 			return -ENOMEM;
1648 		pr_debug("name:%s ", arg->name);
1649 		str = tmp + 1;
1650 	}
1651 
1652 	tmp = strchr(str, '@');
1653 	if (tmp && tmp != str && !strcmp(tmp + 1, "user")) { /* user attr */
1654 		if (!user_access_is_supported()) {
1655 			semantic_error("ftrace does not support user access\n");
1656 			return -EINVAL;
1657 		}
1658 		*tmp = '\0';
1659 		arg->user_access = true;
1660 		pr_debug("user_access ");
1661 	}
1662 
1663 	tmp = strchr(str, ':');
1664 	if (tmp) {	/* Type setting */
1665 		*tmp = '\0';
1666 		arg->type = strdup(tmp + 1);
1667 		if (arg->type == NULL)
1668 			return -ENOMEM;
1669 		pr_debug("type:%s ", arg->type);
1670 	}
1671 
1672 	tmp = strpbrk(str, "-.[");
1673 	if (!is_c_varname(str) || !tmp) {
1674 		/* A variable, register, symbol or special value */
1675 		arg->var = strdup(str);
1676 		if (arg->var == NULL)
1677 			return -ENOMEM;
1678 		pr_debug("%s\n", arg->var);
1679 		return 0;
1680 	}
1681 
1682 	/* Structure fields or array element */
1683 	arg->var = strndup(str, tmp - str);
1684 	if (arg->var == NULL)
1685 		return -ENOMEM;
1686 	goodname = arg->var;
1687 	pr_debug("%s, ", arg->var);
1688 	fieldp = &arg->field;
1689 
1690 	do {
1691 		*fieldp = zalloc(sizeof(struct perf_probe_arg_field));
1692 		if (*fieldp == NULL)
1693 			return -ENOMEM;
1694 		if (*tmp == '[') {	/* Array */
1695 			str = tmp;
1696 			(*fieldp)->index = strtol(str + 1, &tmp, 0);
1697 			(*fieldp)->ref = true;
1698 			if (*tmp != ']' || tmp == str + 1) {
1699 				semantic_error("Array index must be a"
1700 						" number.\n");
1701 				return -EINVAL;
1702 			}
1703 			tmp++;
1704 			if (*tmp == '\0')
1705 				tmp = NULL;
1706 		} else {		/* Structure */
1707 			if (*tmp == '.') {
1708 				str = tmp + 1;
1709 				(*fieldp)->ref = false;
1710 			} else if (tmp[1] == '>') {
1711 				str = tmp + 2;
1712 				(*fieldp)->ref = true;
1713 			} else {
1714 				semantic_error("Argument parse error: %s\n",
1715 					       str);
1716 				return -EINVAL;
1717 			}
1718 			tmp = strpbrk(str, "-.[");
1719 		}
1720 		if (tmp) {
1721 			(*fieldp)->name = strndup(str, tmp - str);
1722 			if ((*fieldp)->name == NULL)
1723 				return -ENOMEM;
1724 			if (*str != '[')
1725 				goodname = (*fieldp)->name;
1726 			pr_debug("%s(%d), ", (*fieldp)->name, (*fieldp)->ref);
1727 			fieldp = &(*fieldp)->next;
1728 		}
1729 	} while (tmp);
1730 	(*fieldp)->name = strdup(str);
1731 	if ((*fieldp)->name == NULL)
1732 		return -ENOMEM;
1733 	if (*str != '[')
1734 		goodname = (*fieldp)->name;
1735 	pr_debug("%s(%d)\n", (*fieldp)->name, (*fieldp)->ref);
1736 
1737 	/* If no name is specified, set the last field name (not array index)*/
1738 	if (!arg->name) {
1739 		arg->name = strdup(goodname);
1740 		if (arg->name == NULL)
1741 			return -ENOMEM;
1742 	}
1743 	return 0;
1744 }
1745 
1746 /* Parse perf-probe event command */
parse_perf_probe_command(const char * cmd,struct perf_probe_event * pev)1747 int parse_perf_probe_command(const char *cmd, struct perf_probe_event *pev)
1748 {
1749 	char **argv;
1750 	int argc, i, ret = 0;
1751 
1752 	argv = argv_split(cmd, &argc);
1753 	if (!argv) {
1754 		pr_debug("Failed to split arguments.\n");
1755 		return -ENOMEM;
1756 	}
1757 	if (argc - 1 > MAX_PROBE_ARGS) {
1758 		semantic_error("Too many probe arguments (%d).\n", argc - 1);
1759 		ret = -ERANGE;
1760 		goto out;
1761 	}
1762 	/* Parse probe point */
1763 	ret = parse_perf_probe_point(argv[0], pev);
1764 	if (ret < 0)
1765 		goto out;
1766 
1767 	/* Generate event name if needed */
1768 	if (!pev->event && pev->point.function && pev->point.line
1769 			&& !pev->point.lazy_line && !pev->point.offset) {
1770 		if (asprintf(&pev->event, "%s_L%d", pev->point.function,
1771 			pev->point.line) < 0)
1772 			return -ENOMEM;
1773 	}
1774 
1775 	/* Copy arguments and ensure return probe has no C argument */
1776 	pev->nargs = argc - 1;
1777 	pev->args = zalloc(sizeof(struct perf_probe_arg) * pev->nargs);
1778 	if (pev->args == NULL) {
1779 		ret = -ENOMEM;
1780 		goto out;
1781 	}
1782 	for (i = 0; i < pev->nargs && ret >= 0; i++) {
1783 		ret = parse_perf_probe_arg(argv[i + 1], &pev->args[i]);
1784 		if (ret >= 0 &&
1785 		    is_c_varname(pev->args[i].var) && pev->point.retprobe) {
1786 			semantic_error("You can't specify local variable for"
1787 				       " kretprobe.\n");
1788 			ret = -EINVAL;
1789 		}
1790 	}
1791 out:
1792 	argv_free(argv);
1793 
1794 	return ret;
1795 }
1796 
1797 /* Returns true if *any* ARG is either C variable, $params or $vars. */
perf_probe_with_var(struct perf_probe_event * pev)1798 bool perf_probe_with_var(struct perf_probe_event *pev)
1799 {
1800 	int i = 0;
1801 
1802 	for (i = 0; i < pev->nargs; i++)
1803 		if (is_c_varname(pev->args[i].var)              ||
1804 		    !strcmp(pev->args[i].var, PROBE_ARG_PARAMS) ||
1805 		    !strcmp(pev->args[i].var, PROBE_ARG_VARS))
1806 			return true;
1807 	return false;
1808 }
1809 
1810 /* Return true if this perf_probe_event requires debuginfo */
perf_probe_event_need_dwarf(struct perf_probe_event * pev)1811 bool perf_probe_event_need_dwarf(struct perf_probe_event *pev)
1812 {
1813 	if (pev->point.file || pev->point.line || pev->point.lazy_line)
1814 		return true;
1815 
1816 	if (perf_probe_with_var(pev))
1817 		return true;
1818 
1819 	return false;
1820 }
1821 
1822 /* Parse probe_events event into struct probe_point */
parse_probe_trace_command(const char * cmd,struct probe_trace_event * tev)1823 int parse_probe_trace_command(const char *cmd, struct probe_trace_event *tev)
1824 {
1825 	struct probe_trace_point *tp = &tev->point;
1826 	char pr;
1827 	char *p;
1828 	char *argv0_str = NULL, *fmt, *fmt1_str, *fmt2_str, *fmt3_str;
1829 	int ret, i, argc;
1830 	char **argv;
1831 
1832 	pr_debug("Parsing probe_events: %s\n", cmd);
1833 	argv = argv_split(cmd, &argc);
1834 	if (!argv) {
1835 		pr_debug("Failed to split arguments.\n");
1836 		return -ENOMEM;
1837 	}
1838 	if (argc < 2) {
1839 		semantic_error("Too few probe arguments.\n");
1840 		ret = -ERANGE;
1841 		goto out;
1842 	}
1843 
1844 	/* Scan event and group name. */
1845 	argv0_str = strdup(argv[0]);
1846 	if (argv0_str == NULL) {
1847 		ret = -ENOMEM;
1848 		goto out;
1849 	}
1850 	fmt1_str = strtok_r(argv0_str, ":", &fmt);
1851 	fmt2_str = strtok_r(NULL, "/", &fmt);
1852 	fmt3_str = strtok_r(NULL, " \t", &fmt);
1853 	if (fmt1_str == NULL || fmt2_str == NULL || fmt3_str == NULL) {
1854 		semantic_error("Failed to parse event name: %s\n", argv[0]);
1855 		ret = -EINVAL;
1856 		goto out;
1857 	}
1858 	pr = fmt1_str[0];
1859 	tev->group = strdup(fmt2_str);
1860 	tev->event = strdup(fmt3_str);
1861 	if (tev->group == NULL || tev->event == NULL) {
1862 		ret = -ENOMEM;
1863 		goto out;
1864 	}
1865 	pr_debug("Group:%s Event:%s probe:%c\n", tev->group, tev->event, pr);
1866 
1867 	tp->retprobe = (pr == 'r');
1868 
1869 	/* Scan module name(if there), function name and offset */
1870 	p = strchr(argv[1], ':');
1871 	if (p) {
1872 		tp->module = strndup(argv[1], p - argv[1]);
1873 		if (!tp->module) {
1874 			ret = -ENOMEM;
1875 			goto out;
1876 		}
1877 		tev->uprobes = (tp->module[0] == '/');
1878 		p++;
1879 	} else
1880 		p = argv[1];
1881 	fmt1_str = strtok_r(p, "+", &fmt);
1882 	/* only the address started with 0x */
1883 	if (fmt1_str[0] == '0')	{
1884 		/*
1885 		 * Fix a special case:
1886 		 * if address == 0, kernel reports something like:
1887 		 * p:probe_libc/abs_0 /lib/libc-2.18.so:0x          (null) arg1=%ax
1888 		 * Newer kernel may fix that, but we want to
1889 		 * support old kernel also.
1890 		 */
1891 		if (strcmp(fmt1_str, "0x") == 0) {
1892 			if (!argv[2] || strcmp(argv[2], "(null)")) {
1893 				ret = -EINVAL;
1894 				goto out;
1895 			}
1896 			tp->address = 0;
1897 
1898 			free(argv[2]);
1899 			for (i = 2; argv[i + 1] != NULL; i++)
1900 				argv[i] = argv[i + 1];
1901 
1902 			argv[i] = NULL;
1903 			argc -= 1;
1904 		} else
1905 			tp->address = strtoul(fmt1_str, NULL, 0);
1906 	} else {
1907 		/* Only the symbol-based probe has offset */
1908 		tp->symbol = strdup(fmt1_str);
1909 		if (tp->symbol == NULL) {
1910 			ret = -ENOMEM;
1911 			goto out;
1912 		}
1913 		fmt2_str = strtok_r(NULL, "", &fmt);
1914 		if (fmt2_str == NULL)
1915 			tp->offset = 0;
1916 		else
1917 			tp->offset = strtoul(fmt2_str, NULL, 10);
1918 	}
1919 
1920 	if (tev->uprobes) {
1921 		fmt2_str = strchr(p, '(');
1922 		if (fmt2_str)
1923 			tp->ref_ctr_offset = strtoul(fmt2_str + 1, NULL, 0);
1924 	}
1925 
1926 	tev->nargs = argc - 2;
1927 	tev->args = zalloc(sizeof(struct probe_trace_arg) * tev->nargs);
1928 	if (tev->args == NULL) {
1929 		ret = -ENOMEM;
1930 		goto out;
1931 	}
1932 	for (i = 0; i < tev->nargs; i++) {
1933 		p = strchr(argv[i + 2], '=');
1934 		if (p)	/* We don't need which register is assigned. */
1935 			*p++ = '\0';
1936 		else
1937 			p = argv[i + 2];
1938 		tev->args[i].name = strdup(argv[i + 2]);
1939 		/* TODO: parse regs and offset */
1940 		tev->args[i].value = strdup(p);
1941 		if (tev->args[i].name == NULL || tev->args[i].value == NULL) {
1942 			ret = -ENOMEM;
1943 			goto out;
1944 		}
1945 	}
1946 	ret = 0;
1947 out:
1948 	free(argv0_str);
1949 	argv_free(argv);
1950 	return ret;
1951 }
1952 
1953 /* Compose only probe arg */
synthesize_perf_probe_arg(struct perf_probe_arg * pa)1954 char *synthesize_perf_probe_arg(struct perf_probe_arg *pa)
1955 {
1956 	struct perf_probe_arg_field *field = pa->field;
1957 	struct strbuf buf;
1958 	char *ret = NULL;
1959 	int err;
1960 
1961 	if (strbuf_init(&buf, 64) < 0)
1962 		return NULL;
1963 
1964 	if (pa->name && pa->var)
1965 		err = strbuf_addf(&buf, "%s=%s", pa->name, pa->var);
1966 	else
1967 		err = strbuf_addstr(&buf, pa->name ?: pa->var);
1968 	if (err)
1969 		goto out;
1970 
1971 	while (field) {
1972 		if (field->name[0] == '[')
1973 			err = strbuf_addstr(&buf, field->name);
1974 		else
1975 			err = strbuf_addf(&buf, "%s%s", field->ref ? "->" : ".",
1976 					  field->name);
1977 		field = field->next;
1978 		if (err)
1979 			goto out;
1980 	}
1981 
1982 	if (pa->type)
1983 		if (strbuf_addf(&buf, ":%s", pa->type) < 0)
1984 			goto out;
1985 
1986 	ret = strbuf_detach(&buf, NULL);
1987 out:
1988 	strbuf_release(&buf);
1989 	return ret;
1990 }
1991 
1992 /* Compose only probe point (not argument) */
synthesize_perf_probe_point(struct perf_probe_point * pp)1993 char *synthesize_perf_probe_point(struct perf_probe_point *pp)
1994 {
1995 	struct strbuf buf;
1996 	char *tmp, *ret = NULL;
1997 	int len, err = 0;
1998 
1999 	if (strbuf_init(&buf, 64) < 0)
2000 		return NULL;
2001 
2002 	if (pp->function) {
2003 		if (strbuf_addstr(&buf, pp->function) < 0)
2004 			goto out;
2005 		if (pp->offset)
2006 			err = strbuf_addf(&buf, "+%lu", pp->offset);
2007 		else if (pp->line)
2008 			err = strbuf_addf(&buf, ":%d", pp->line);
2009 		else if (pp->retprobe)
2010 			err = strbuf_addstr(&buf, "%return");
2011 		if (err)
2012 			goto out;
2013 	}
2014 	if (pp->file) {
2015 		tmp = pp->file;
2016 		len = strlen(tmp);
2017 		if (len > 30) {
2018 			tmp = strchr(pp->file + len - 30, '/');
2019 			tmp = tmp ? tmp + 1 : pp->file + len - 30;
2020 		}
2021 		err = strbuf_addf(&buf, "@%s", tmp);
2022 		if (!err && !pp->function && pp->line)
2023 			err = strbuf_addf(&buf, ":%d", pp->line);
2024 	}
2025 	if (!err)
2026 		ret = strbuf_detach(&buf, NULL);
2027 out:
2028 	strbuf_release(&buf);
2029 	return ret;
2030 }
2031 
synthesize_perf_probe_command(struct perf_probe_event * pev)2032 char *synthesize_perf_probe_command(struct perf_probe_event *pev)
2033 {
2034 	struct strbuf buf;
2035 	char *tmp, *ret = NULL;
2036 	int i;
2037 
2038 	if (strbuf_init(&buf, 64))
2039 		return NULL;
2040 	if (pev->event)
2041 		if (strbuf_addf(&buf, "%s:%s=", pev->group ?: PERFPROBE_GROUP,
2042 				pev->event) < 0)
2043 			goto out;
2044 
2045 	tmp = synthesize_perf_probe_point(&pev->point);
2046 	if (!tmp || strbuf_addstr(&buf, tmp) < 0)
2047 		goto out;
2048 	free(tmp);
2049 
2050 	for (i = 0; i < pev->nargs; i++) {
2051 		tmp = synthesize_perf_probe_arg(pev->args + i);
2052 		if (!tmp || strbuf_addf(&buf, " %s", tmp) < 0)
2053 			goto out;
2054 		free(tmp);
2055 	}
2056 
2057 	ret = strbuf_detach(&buf, NULL);
2058 out:
2059 	strbuf_release(&buf);
2060 	return ret;
2061 }
2062 
__synthesize_probe_trace_arg_ref(struct probe_trace_arg_ref * ref,struct strbuf * buf,int depth)2063 static int __synthesize_probe_trace_arg_ref(struct probe_trace_arg_ref *ref,
2064 					    struct strbuf *buf, int depth)
2065 {
2066 	int err;
2067 	if (ref->next) {
2068 		depth = __synthesize_probe_trace_arg_ref(ref->next, buf,
2069 							 depth + 1);
2070 		if (depth < 0)
2071 			return depth;
2072 	}
2073 	if (ref->user_access)
2074 		err = strbuf_addf(buf, "%s%ld(", "+u", ref->offset);
2075 	else
2076 		err = strbuf_addf(buf, "%+ld(", ref->offset);
2077 	return (err < 0) ? err : depth;
2078 }
2079 
synthesize_probe_trace_arg(struct probe_trace_arg * arg,struct strbuf * buf)2080 static int synthesize_probe_trace_arg(struct probe_trace_arg *arg,
2081 				      struct strbuf *buf)
2082 {
2083 	struct probe_trace_arg_ref *ref = arg->ref;
2084 	int depth = 0, err;
2085 
2086 	/* Argument name or separator */
2087 	if (arg->name)
2088 		err = strbuf_addf(buf, " %s=", arg->name);
2089 	else
2090 		err = strbuf_addch(buf, ' ');
2091 	if (err)
2092 		return err;
2093 
2094 	/* Special case: @XXX */
2095 	if (arg->value[0] == '@' && arg->ref)
2096 			ref = ref->next;
2097 
2098 	/* Dereferencing arguments */
2099 	if (ref) {
2100 		depth = __synthesize_probe_trace_arg_ref(ref, buf, 1);
2101 		if (depth < 0)
2102 			return depth;
2103 	}
2104 
2105 	/* Print argument value */
2106 	if (arg->value[0] == '@' && arg->ref)
2107 		err = strbuf_addf(buf, "%s%+ld", arg->value, arg->ref->offset);
2108 	else
2109 		err = strbuf_addstr(buf, arg->value);
2110 
2111 	/* Closing */
2112 	while (!err && depth--)
2113 		err = strbuf_addch(buf, ')');
2114 
2115 	/* Print argument type */
2116 	if (!err && arg->type)
2117 		err = strbuf_addf(buf, ":%s", arg->type);
2118 
2119 	return err;
2120 }
2121 
2122 static int
synthesize_uprobe_trace_def(struct probe_trace_event * tev,struct strbuf * buf)2123 synthesize_uprobe_trace_def(struct probe_trace_event *tev, struct strbuf *buf)
2124 {
2125 	struct probe_trace_point *tp = &tev->point;
2126 	int err;
2127 
2128 	err = strbuf_addf(buf, "%s:0x%lx", tp->module, tp->address);
2129 
2130 	if (err >= 0 && tp->ref_ctr_offset) {
2131 		if (!uprobe_ref_ctr_is_supported())
2132 			return -1;
2133 		err = strbuf_addf(buf, "(0x%lx)", tp->ref_ctr_offset);
2134 	}
2135 	return err >= 0 ? 0 : -1;
2136 }
2137 
synthesize_probe_trace_command(struct probe_trace_event * tev)2138 char *synthesize_probe_trace_command(struct probe_trace_event *tev)
2139 {
2140 	struct probe_trace_point *tp = &tev->point;
2141 	struct strbuf buf;
2142 	char *ret = NULL;
2143 	int i, err;
2144 
2145 	/* Uprobes must have tp->module */
2146 	if (tev->uprobes && !tp->module)
2147 		return NULL;
2148 
2149 	if (strbuf_init(&buf, 32) < 0)
2150 		return NULL;
2151 
2152 	if (strbuf_addf(&buf, "%c:%s/%s ", tp->retprobe ? 'r' : 'p',
2153 			tev->group, tev->event) < 0)
2154 		goto error;
2155 	/*
2156 	 * If tp->address == 0, then this point must be a
2157 	 * absolute address uprobe.
2158 	 * try_to_find_absolute_address() should have made
2159 	 * tp->symbol to "0x0".
2160 	 */
2161 	if (tev->uprobes && !tp->address) {
2162 		if (!tp->symbol || strcmp(tp->symbol, "0x0"))
2163 			goto error;
2164 	}
2165 
2166 	/* Use the tp->address for uprobes */
2167 	if (tev->uprobes) {
2168 		err = synthesize_uprobe_trace_def(tev, &buf);
2169 	} else if (!strncmp(tp->symbol, "0x", 2)) {
2170 		/* Absolute address. See try_to_find_absolute_address() */
2171 		err = strbuf_addf(&buf, "%s%s0x%lx", tp->module ?: "",
2172 				  tp->module ? ":" : "", tp->address);
2173 	} else {
2174 		err = strbuf_addf(&buf, "%s%s%s+%lu", tp->module ?: "",
2175 				tp->module ? ":" : "", tp->symbol, tp->offset);
2176 	}
2177 
2178 	if (err)
2179 		goto error;
2180 
2181 	for (i = 0; i < tev->nargs; i++)
2182 		if (synthesize_probe_trace_arg(&tev->args[i], &buf) < 0)
2183 			goto error;
2184 
2185 	ret = strbuf_detach(&buf, NULL);
2186 error:
2187 	strbuf_release(&buf);
2188 	return ret;
2189 }
2190 
find_perf_probe_point_from_map(struct probe_trace_point * tp,struct perf_probe_point * pp,bool is_kprobe)2191 static int find_perf_probe_point_from_map(struct probe_trace_point *tp,
2192 					  struct perf_probe_point *pp,
2193 					  bool is_kprobe)
2194 {
2195 	struct symbol *sym = NULL;
2196 	struct map *map = NULL;
2197 	u64 addr = tp->address;
2198 	int ret = -ENOENT;
2199 
2200 	if (!is_kprobe) {
2201 		map = dso__new_map(tp->module);
2202 		if (!map)
2203 			goto out;
2204 		sym = map__find_symbol(map, addr);
2205 	} else {
2206 		if (tp->symbol && !addr) {
2207 			if (kernel_get_symbol_address_by_name(tp->symbol,
2208 						&addr, true, false) < 0)
2209 				goto out;
2210 		}
2211 		if (addr) {
2212 			addr += tp->offset;
2213 			sym = machine__find_kernel_symbol(host_machine, addr, &map);
2214 		}
2215 	}
2216 
2217 	if (!sym)
2218 		goto out;
2219 
2220 	pp->retprobe = tp->retprobe;
2221 	pp->offset = addr - map->unmap_ip(map, sym->start);
2222 	pp->function = strdup(sym->name);
2223 	ret = pp->function ? 0 : -ENOMEM;
2224 
2225 out:
2226 	if (map && !is_kprobe) {
2227 		map__put(map);
2228 	}
2229 
2230 	return ret;
2231 }
2232 
convert_to_perf_probe_point(struct probe_trace_point * tp,struct perf_probe_point * pp,bool is_kprobe)2233 static int convert_to_perf_probe_point(struct probe_trace_point *tp,
2234 				       struct perf_probe_point *pp,
2235 				       bool is_kprobe)
2236 {
2237 	char buf[128];
2238 	int ret;
2239 
2240 	ret = find_perf_probe_point_from_dwarf(tp, pp, is_kprobe);
2241 	if (!ret)
2242 		return 0;
2243 	ret = find_perf_probe_point_from_map(tp, pp, is_kprobe);
2244 	if (!ret)
2245 		return 0;
2246 
2247 	pr_debug("Failed to find probe point from both of dwarf and map.\n");
2248 
2249 	if (tp->symbol) {
2250 		pp->function = strdup(tp->symbol);
2251 		pp->offset = tp->offset;
2252 	} else {
2253 		ret = e_snprintf(buf, 128, "0x%" PRIx64, (u64)tp->address);
2254 		if (ret < 0)
2255 			return ret;
2256 		pp->function = strdup(buf);
2257 		pp->offset = 0;
2258 	}
2259 	if (pp->function == NULL)
2260 		return -ENOMEM;
2261 
2262 	pp->retprobe = tp->retprobe;
2263 
2264 	return 0;
2265 }
2266 
convert_to_perf_probe_event(struct probe_trace_event * tev,struct perf_probe_event * pev,bool is_kprobe)2267 static int convert_to_perf_probe_event(struct probe_trace_event *tev,
2268 			       struct perf_probe_event *pev, bool is_kprobe)
2269 {
2270 	struct strbuf buf = STRBUF_INIT;
2271 	int i, ret;
2272 
2273 	/* Convert event/group name */
2274 	pev->event = strdup(tev->event);
2275 	pev->group = strdup(tev->group);
2276 	if (pev->event == NULL || pev->group == NULL)
2277 		return -ENOMEM;
2278 
2279 	/* Convert trace_point to probe_point */
2280 	ret = convert_to_perf_probe_point(&tev->point, &pev->point, is_kprobe);
2281 	if (ret < 0)
2282 		return ret;
2283 
2284 	/* Convert trace_arg to probe_arg */
2285 	pev->nargs = tev->nargs;
2286 	pev->args = zalloc(sizeof(struct perf_probe_arg) * pev->nargs);
2287 	if (pev->args == NULL)
2288 		return -ENOMEM;
2289 	for (i = 0; i < tev->nargs && ret >= 0; i++) {
2290 		if (tev->args[i].name)
2291 			pev->args[i].name = strdup(tev->args[i].name);
2292 		else {
2293 			if ((ret = strbuf_init(&buf, 32)) < 0)
2294 				goto error;
2295 			ret = synthesize_probe_trace_arg(&tev->args[i], &buf);
2296 			pev->args[i].name = strbuf_detach(&buf, NULL);
2297 		}
2298 		if (pev->args[i].name == NULL && ret >= 0)
2299 			ret = -ENOMEM;
2300 	}
2301 error:
2302 	if (ret < 0)
2303 		clear_perf_probe_event(pev);
2304 
2305 	return ret;
2306 }
2307 
clear_perf_probe_event(struct perf_probe_event * pev)2308 void clear_perf_probe_event(struct perf_probe_event *pev)
2309 {
2310 	struct perf_probe_arg_field *field, *next;
2311 	int i;
2312 
2313 	zfree(&pev->event);
2314 	zfree(&pev->group);
2315 	zfree(&pev->target);
2316 	clear_perf_probe_point(&pev->point);
2317 
2318 	for (i = 0; i < pev->nargs; i++) {
2319 		zfree(&pev->args[i].name);
2320 		zfree(&pev->args[i].var);
2321 		zfree(&pev->args[i].type);
2322 		field = pev->args[i].field;
2323 		while (field) {
2324 			next = field->next;
2325 			zfree(&field->name);
2326 			free(field);
2327 			field = next;
2328 		}
2329 	}
2330 	pev->nargs = 0;
2331 	zfree(&pev->args);
2332 }
2333 
2334 #define strdup_or_goto(str, label)	\
2335 ({ char *__p = NULL; if (str && !(__p = strdup(str))) goto label; __p; })
2336 
perf_probe_point__copy(struct perf_probe_point * dst,struct perf_probe_point * src)2337 static int perf_probe_point__copy(struct perf_probe_point *dst,
2338 				  struct perf_probe_point *src)
2339 {
2340 	dst->file = strdup_or_goto(src->file, out_err);
2341 	dst->function = strdup_or_goto(src->function, out_err);
2342 	dst->lazy_line = strdup_or_goto(src->lazy_line, out_err);
2343 	dst->line = src->line;
2344 	dst->retprobe = src->retprobe;
2345 	dst->offset = src->offset;
2346 	return 0;
2347 
2348 out_err:
2349 	clear_perf_probe_point(dst);
2350 	return -ENOMEM;
2351 }
2352 
perf_probe_arg__copy(struct perf_probe_arg * dst,struct perf_probe_arg * src)2353 static int perf_probe_arg__copy(struct perf_probe_arg *dst,
2354 				struct perf_probe_arg *src)
2355 {
2356 	struct perf_probe_arg_field *field, **ppfield;
2357 
2358 	dst->name = strdup_or_goto(src->name, out_err);
2359 	dst->var = strdup_or_goto(src->var, out_err);
2360 	dst->type = strdup_or_goto(src->type, out_err);
2361 
2362 	field = src->field;
2363 	ppfield = &(dst->field);
2364 	while (field) {
2365 		*ppfield = zalloc(sizeof(*field));
2366 		if (!*ppfield)
2367 			goto out_err;
2368 		(*ppfield)->name = strdup_or_goto(field->name, out_err);
2369 		(*ppfield)->index = field->index;
2370 		(*ppfield)->ref = field->ref;
2371 		field = field->next;
2372 		ppfield = &((*ppfield)->next);
2373 	}
2374 	return 0;
2375 out_err:
2376 	return -ENOMEM;
2377 }
2378 
perf_probe_event__copy(struct perf_probe_event * dst,struct perf_probe_event * src)2379 int perf_probe_event__copy(struct perf_probe_event *dst,
2380 			   struct perf_probe_event *src)
2381 {
2382 	int i;
2383 
2384 	dst->event = strdup_or_goto(src->event, out_err);
2385 	dst->group = strdup_or_goto(src->group, out_err);
2386 	dst->target = strdup_or_goto(src->target, out_err);
2387 	dst->uprobes = src->uprobes;
2388 
2389 	if (perf_probe_point__copy(&dst->point, &src->point) < 0)
2390 		goto out_err;
2391 
2392 	dst->args = zalloc(sizeof(struct perf_probe_arg) * src->nargs);
2393 	if (!dst->args)
2394 		goto out_err;
2395 	dst->nargs = src->nargs;
2396 
2397 	for (i = 0; i < src->nargs; i++)
2398 		if (perf_probe_arg__copy(&dst->args[i], &src->args[i]) < 0)
2399 			goto out_err;
2400 	return 0;
2401 
2402 out_err:
2403 	clear_perf_probe_event(dst);
2404 	return -ENOMEM;
2405 }
2406 
clear_probe_trace_event(struct probe_trace_event * tev)2407 void clear_probe_trace_event(struct probe_trace_event *tev)
2408 {
2409 	struct probe_trace_arg_ref *ref, *next;
2410 	int i;
2411 
2412 	zfree(&tev->event);
2413 	zfree(&tev->group);
2414 	zfree(&tev->point.symbol);
2415 	zfree(&tev->point.realname);
2416 	zfree(&tev->point.module);
2417 	for (i = 0; i < tev->nargs; i++) {
2418 		zfree(&tev->args[i].name);
2419 		zfree(&tev->args[i].value);
2420 		zfree(&tev->args[i].type);
2421 		ref = tev->args[i].ref;
2422 		while (ref) {
2423 			next = ref->next;
2424 			free(ref);
2425 			ref = next;
2426 		}
2427 	}
2428 	zfree(&tev->args);
2429 	tev->nargs = 0;
2430 }
2431 
2432 struct kprobe_blacklist_node {
2433 	struct list_head list;
2434 	unsigned long start;
2435 	unsigned long end;
2436 	char *symbol;
2437 };
2438 
kprobe_blacklist__delete(struct list_head * blacklist)2439 static void kprobe_blacklist__delete(struct list_head *blacklist)
2440 {
2441 	struct kprobe_blacklist_node *node;
2442 
2443 	while (!list_empty(blacklist)) {
2444 		node = list_first_entry(blacklist,
2445 					struct kprobe_blacklist_node, list);
2446 		list_del_init(&node->list);
2447 		zfree(&node->symbol);
2448 		free(node);
2449 	}
2450 }
2451 
kprobe_blacklist__load(struct list_head * blacklist)2452 static int kprobe_blacklist__load(struct list_head *blacklist)
2453 {
2454 	struct kprobe_blacklist_node *node;
2455 	const char *__debugfs = debugfs__mountpoint();
2456 	char buf[PATH_MAX], *p;
2457 	FILE *fp;
2458 	int ret;
2459 
2460 	if (__debugfs == NULL)
2461 		return -ENOTSUP;
2462 
2463 	ret = e_snprintf(buf, PATH_MAX, "%s/kprobes/blacklist", __debugfs);
2464 	if (ret < 0)
2465 		return ret;
2466 
2467 	fp = fopen(buf, "r");
2468 	if (!fp)
2469 		return -errno;
2470 
2471 	ret = 0;
2472 	while (fgets(buf, PATH_MAX, fp)) {
2473 		node = zalloc(sizeof(*node));
2474 		if (!node) {
2475 			ret = -ENOMEM;
2476 			break;
2477 		}
2478 		INIT_LIST_HEAD(&node->list);
2479 		list_add_tail(&node->list, blacklist);
2480 		if (sscanf(buf, "0x%lx-0x%lx", &node->start, &node->end) != 2) {
2481 			ret = -EINVAL;
2482 			break;
2483 		}
2484 		p = strchr(buf, '\t');
2485 		if (p) {
2486 			p++;
2487 			if (p[strlen(p) - 1] == '\n')
2488 				p[strlen(p) - 1] = '\0';
2489 		} else
2490 			p = (char *)"unknown";
2491 		node->symbol = strdup(p);
2492 		if (!node->symbol) {
2493 			ret = -ENOMEM;
2494 			break;
2495 		}
2496 		pr_debug2("Blacklist: 0x%lx-0x%lx, %s\n",
2497 			  node->start, node->end, node->symbol);
2498 		ret++;
2499 	}
2500 	if (ret < 0)
2501 		kprobe_blacklist__delete(blacklist);
2502 	fclose(fp);
2503 
2504 	return ret;
2505 }
2506 
2507 static struct kprobe_blacklist_node *
kprobe_blacklist__find_by_address(struct list_head * blacklist,unsigned long address)2508 kprobe_blacklist__find_by_address(struct list_head *blacklist,
2509 				  unsigned long address)
2510 {
2511 	struct kprobe_blacklist_node *node;
2512 
2513 	list_for_each_entry(node, blacklist, list) {
2514 		if (node->start <= address && address < node->end)
2515 			return node;
2516 	}
2517 
2518 	return NULL;
2519 }
2520 
2521 static LIST_HEAD(kprobe_blacklist);
2522 
kprobe_blacklist__init(void)2523 static void kprobe_blacklist__init(void)
2524 {
2525 	if (!list_empty(&kprobe_blacklist))
2526 		return;
2527 
2528 	if (kprobe_blacklist__load(&kprobe_blacklist) < 0)
2529 		pr_debug("No kprobe blacklist support, ignored\n");
2530 }
2531 
kprobe_blacklist__release(void)2532 static void kprobe_blacklist__release(void)
2533 {
2534 	kprobe_blacklist__delete(&kprobe_blacklist);
2535 }
2536 
kprobe_blacklist__listed(unsigned long address)2537 static bool kprobe_blacklist__listed(unsigned long address)
2538 {
2539 	return !!kprobe_blacklist__find_by_address(&kprobe_blacklist, address);
2540 }
2541 
perf_probe_event__sprintf(const char * group,const char * event,struct perf_probe_event * pev,const char * module,struct strbuf * result)2542 static int perf_probe_event__sprintf(const char *group, const char *event,
2543 				     struct perf_probe_event *pev,
2544 				     const char *module,
2545 				     struct strbuf *result)
2546 {
2547 	int i, ret;
2548 	char *buf;
2549 
2550 	if (asprintf(&buf, "%s:%s", group, event) < 0)
2551 		return -errno;
2552 	ret = strbuf_addf(result, "  %-20s (on ", buf);
2553 	free(buf);
2554 	if (ret)
2555 		return ret;
2556 
2557 	/* Synthesize only event probe point */
2558 	buf = synthesize_perf_probe_point(&pev->point);
2559 	if (!buf)
2560 		return -ENOMEM;
2561 	ret = strbuf_addstr(result, buf);
2562 	free(buf);
2563 
2564 	if (!ret && module)
2565 		ret = strbuf_addf(result, " in %s", module);
2566 
2567 	if (!ret && pev->nargs > 0) {
2568 		ret = strbuf_add(result, " with", 5);
2569 		for (i = 0; !ret && i < pev->nargs; i++) {
2570 			buf = synthesize_perf_probe_arg(&pev->args[i]);
2571 			if (!buf)
2572 				return -ENOMEM;
2573 			ret = strbuf_addf(result, " %s", buf);
2574 			free(buf);
2575 		}
2576 	}
2577 	if (!ret)
2578 		ret = strbuf_addch(result, ')');
2579 
2580 	return ret;
2581 }
2582 
2583 /* Show an event */
show_perf_probe_event(const char * group,const char * event,struct perf_probe_event * pev,const char * module,bool use_stdout)2584 int show_perf_probe_event(const char *group, const char *event,
2585 			  struct perf_probe_event *pev,
2586 			  const char *module, bool use_stdout)
2587 {
2588 	struct strbuf buf = STRBUF_INIT;
2589 	int ret;
2590 
2591 	ret = perf_probe_event__sprintf(group, event, pev, module, &buf);
2592 	if (ret >= 0) {
2593 		if (use_stdout)
2594 			printf("%s\n", buf.buf);
2595 		else
2596 			pr_info("%s\n", buf.buf);
2597 	}
2598 	strbuf_release(&buf);
2599 
2600 	return ret;
2601 }
2602 
filter_probe_trace_event(struct probe_trace_event * tev,struct strfilter * filter)2603 static bool filter_probe_trace_event(struct probe_trace_event *tev,
2604 				     struct strfilter *filter)
2605 {
2606 	char tmp[128];
2607 
2608 	/* At first, check the event name itself */
2609 	if (strfilter__compare(filter, tev->event))
2610 		return true;
2611 
2612 	/* Next, check the combination of name and group */
2613 	if (e_snprintf(tmp, 128, "%s:%s", tev->group, tev->event) < 0)
2614 		return false;
2615 	return strfilter__compare(filter, tmp);
2616 }
2617 
__show_perf_probe_events(int fd,bool is_kprobe,struct strfilter * filter)2618 static int __show_perf_probe_events(int fd, bool is_kprobe,
2619 				    struct strfilter *filter)
2620 {
2621 	int ret = 0;
2622 	struct probe_trace_event tev;
2623 	struct perf_probe_event pev;
2624 	struct strlist *rawlist;
2625 	struct str_node *ent;
2626 
2627 	memset(&tev, 0, sizeof(tev));
2628 	memset(&pev, 0, sizeof(pev));
2629 
2630 	rawlist = probe_file__get_rawlist(fd);
2631 	if (!rawlist)
2632 		return -ENOMEM;
2633 
2634 	strlist__for_each_entry(ent, rawlist) {
2635 		ret = parse_probe_trace_command(ent->s, &tev);
2636 		if (ret >= 0) {
2637 			if (!filter_probe_trace_event(&tev, filter))
2638 				goto next;
2639 			ret = convert_to_perf_probe_event(&tev, &pev,
2640 								is_kprobe);
2641 			if (ret < 0)
2642 				goto next;
2643 			ret = show_perf_probe_event(pev.group, pev.event,
2644 						    &pev, tev.point.module,
2645 						    true);
2646 		}
2647 next:
2648 		clear_perf_probe_event(&pev);
2649 		clear_probe_trace_event(&tev);
2650 		if (ret < 0)
2651 			break;
2652 	}
2653 	strlist__delete(rawlist);
2654 	/* Cleanup cached debuginfo if needed */
2655 	debuginfo_cache__exit();
2656 
2657 	return ret;
2658 }
2659 
2660 /* List up current perf-probe events */
show_perf_probe_events(struct strfilter * filter)2661 int show_perf_probe_events(struct strfilter *filter)
2662 {
2663 	int kp_fd, up_fd, ret;
2664 
2665 	setup_pager();
2666 
2667 	if (probe_conf.cache)
2668 		return probe_cache__show_all_caches(filter);
2669 
2670 	ret = init_probe_symbol_maps(false);
2671 	if (ret < 0)
2672 		return ret;
2673 
2674 	ret = probe_file__open_both(&kp_fd, &up_fd, 0);
2675 	if (ret < 0)
2676 		return ret;
2677 
2678 	if (kp_fd >= 0)
2679 		ret = __show_perf_probe_events(kp_fd, true, filter);
2680 	if (up_fd >= 0 && ret >= 0)
2681 		ret = __show_perf_probe_events(up_fd, false, filter);
2682 	if (kp_fd > 0)
2683 		close(kp_fd);
2684 	if (up_fd > 0)
2685 		close(up_fd);
2686 	exit_probe_symbol_maps();
2687 
2688 	return ret;
2689 }
2690 
get_new_event_name(char * buf,size_t len,const char * base,struct strlist * namelist,bool ret_event,bool allow_suffix)2691 static int get_new_event_name(char *buf, size_t len, const char *base,
2692 			      struct strlist *namelist, bool ret_event,
2693 			      bool allow_suffix)
2694 {
2695 	int i, ret;
2696 	char *p, *nbase;
2697 
2698 	if (*base == '.')
2699 		base++;
2700 	nbase = strdup(base);
2701 	if (!nbase)
2702 		return -ENOMEM;
2703 
2704 	/* Cut off the dot suffixes (e.g. .const, .isra) and version suffixes */
2705 	p = strpbrk(nbase, ".@");
2706 	if (p && p != nbase)
2707 		*p = '\0';
2708 
2709 	/* Try no suffix number */
2710 	ret = e_snprintf(buf, len, "%s%s", nbase, ret_event ? "__return" : "");
2711 	if (ret < 0) {
2712 		pr_debug("snprintf() failed: %d\n", ret);
2713 		goto out;
2714 	}
2715 	if (!strlist__has_entry(namelist, buf))
2716 		goto out;
2717 
2718 	if (!allow_suffix) {
2719 		pr_warning("Error: event \"%s\" already exists.\n"
2720 			   " Hint: Remove existing event by 'perf probe -d'\n"
2721 			   "       or force duplicates by 'perf probe -f'\n"
2722 			   "       or set 'force=yes' in BPF source.\n",
2723 			   buf);
2724 		ret = -EEXIST;
2725 		goto out;
2726 	}
2727 
2728 	/* Try to add suffix */
2729 	for (i = 1; i < MAX_EVENT_INDEX; i++) {
2730 		ret = e_snprintf(buf, len, "%s_%d", nbase, i);
2731 		if (ret < 0) {
2732 			pr_debug("snprintf() failed: %d\n", ret);
2733 			goto out;
2734 		}
2735 		if (!strlist__has_entry(namelist, buf))
2736 			break;
2737 	}
2738 	if (i == MAX_EVENT_INDEX) {
2739 		pr_warning("Too many events are on the same function.\n");
2740 		ret = -ERANGE;
2741 	}
2742 
2743 out:
2744 	free(nbase);
2745 
2746 	/* Final validation */
2747 	if (ret >= 0 && !is_c_func_name(buf)) {
2748 		pr_warning("Internal error: \"%s\" is an invalid event name.\n",
2749 			   buf);
2750 		ret = -EINVAL;
2751 	}
2752 
2753 	return ret;
2754 }
2755 
2756 /* Warn if the current kernel's uprobe implementation is old */
warn_uprobe_event_compat(struct probe_trace_event * tev)2757 static void warn_uprobe_event_compat(struct probe_trace_event *tev)
2758 {
2759 	int i;
2760 	char *buf = synthesize_probe_trace_command(tev);
2761 	struct probe_trace_point *tp = &tev->point;
2762 
2763 	if (tp->ref_ctr_offset && !uprobe_ref_ctr_is_supported()) {
2764 		pr_warning("A semaphore is associated with %s:%s and "
2765 			   "seems your kernel doesn't support it.\n",
2766 			   tev->group, tev->event);
2767 	}
2768 
2769 	/* Old uprobe event doesn't support memory dereference */
2770 	if (!tev->uprobes || tev->nargs == 0 || !buf)
2771 		goto out;
2772 
2773 	for (i = 0; i < tev->nargs; i++)
2774 		if (strglobmatch(tev->args[i].value, "[$@+-]*")) {
2775 			pr_warning("Please upgrade your kernel to at least "
2776 				   "3.14 to have access to feature %s\n",
2777 				   tev->args[i].value);
2778 			break;
2779 		}
2780 out:
2781 	free(buf);
2782 }
2783 
2784 /* Set new name from original perf_probe_event and namelist */
probe_trace_event__set_name(struct probe_trace_event * tev,struct perf_probe_event * pev,struct strlist * namelist,bool allow_suffix)2785 static int probe_trace_event__set_name(struct probe_trace_event *tev,
2786 				       struct perf_probe_event *pev,
2787 				       struct strlist *namelist,
2788 				       bool allow_suffix)
2789 {
2790 	const char *event, *group;
2791 	char buf[64];
2792 	int ret;
2793 
2794 	/* If probe_event or trace_event already have the name, reuse it */
2795 	if (pev->event && !pev->sdt)
2796 		event = pev->event;
2797 	else if (tev->event)
2798 		event = tev->event;
2799 	else {
2800 		/* Or generate new one from probe point */
2801 		if (pev->point.function &&
2802 			(strncmp(pev->point.function, "0x", 2) != 0) &&
2803 			!strisglob(pev->point.function))
2804 			event = pev->point.function;
2805 		else
2806 			event = tev->point.realname;
2807 	}
2808 	if (pev->group && !pev->sdt)
2809 		group = pev->group;
2810 	else if (tev->group)
2811 		group = tev->group;
2812 	else
2813 		group = PERFPROBE_GROUP;
2814 
2815 	/* Get an unused new event name */
2816 	ret = get_new_event_name(buf, 64, event, namelist,
2817 				 tev->point.retprobe, allow_suffix);
2818 	if (ret < 0)
2819 		return ret;
2820 
2821 	event = buf;
2822 
2823 	tev->event = strdup(event);
2824 	tev->group = strdup(group);
2825 	if (tev->event == NULL || tev->group == NULL)
2826 		return -ENOMEM;
2827 
2828 	/*
2829 	 * Add new event name to namelist if multiprobe event is NOT
2830 	 * supported, since we have to use new event name for following
2831 	 * probes in that case.
2832 	 */
2833 	if (!multiprobe_event_is_supported())
2834 		strlist__add(namelist, event);
2835 	return 0;
2836 }
2837 
__open_probe_file_and_namelist(bool uprobe,struct strlist ** namelist)2838 static int __open_probe_file_and_namelist(bool uprobe,
2839 					  struct strlist **namelist)
2840 {
2841 	int fd;
2842 
2843 	fd = probe_file__open(PF_FL_RW | (uprobe ? PF_FL_UPROBE : 0));
2844 	if (fd < 0)
2845 		return fd;
2846 
2847 	/* Get current event names */
2848 	*namelist = probe_file__get_namelist(fd);
2849 	if (!(*namelist)) {
2850 		pr_debug("Failed to get current event list.\n");
2851 		close(fd);
2852 		return -ENOMEM;
2853 	}
2854 	return fd;
2855 }
2856 
__add_probe_trace_events(struct perf_probe_event * pev,struct probe_trace_event * tevs,int ntevs,bool allow_suffix)2857 static int __add_probe_trace_events(struct perf_probe_event *pev,
2858 				     struct probe_trace_event *tevs,
2859 				     int ntevs, bool allow_suffix)
2860 {
2861 	int i, fd[2] = {-1, -1}, up, ret;
2862 	struct probe_trace_event *tev = NULL;
2863 	struct probe_cache *cache = NULL;
2864 	struct strlist *namelist[2] = {NULL, NULL};
2865 	struct nscookie nsc;
2866 
2867 	up = pev->uprobes ? 1 : 0;
2868 	fd[up] = __open_probe_file_and_namelist(up, &namelist[up]);
2869 	if (fd[up] < 0)
2870 		return fd[up];
2871 
2872 	ret = 0;
2873 	for (i = 0; i < ntevs; i++) {
2874 		tev = &tevs[i];
2875 		up = tev->uprobes ? 1 : 0;
2876 		if (fd[up] == -1) {	/* Open the kprobe/uprobe_events */
2877 			fd[up] = __open_probe_file_and_namelist(up,
2878 								&namelist[up]);
2879 			if (fd[up] < 0)
2880 				goto close_out;
2881 		}
2882 		/* Skip if the symbol is out of .text or blacklisted */
2883 		if (!tev->point.symbol && !pev->uprobes)
2884 			continue;
2885 
2886 		/* Set new name for tev (and update namelist) */
2887 		ret = probe_trace_event__set_name(tev, pev, namelist[up],
2888 						  allow_suffix);
2889 		if (ret < 0)
2890 			break;
2891 
2892 		nsinfo__mountns_enter(pev->nsi, &nsc);
2893 		ret = probe_file__add_event(fd[up], tev);
2894 		nsinfo__mountns_exit(&nsc);
2895 		if (ret < 0)
2896 			break;
2897 
2898 		/*
2899 		 * Probes after the first probe which comes from same
2900 		 * user input are always allowed to add suffix, because
2901 		 * there might be several addresses corresponding to
2902 		 * one code line.
2903 		 */
2904 		allow_suffix = true;
2905 	}
2906 	if (ret == -EINVAL && pev->uprobes)
2907 		warn_uprobe_event_compat(tev);
2908 	if (ret == 0 && probe_conf.cache) {
2909 		cache = probe_cache__new(pev->target, pev->nsi);
2910 		if (!cache ||
2911 		    probe_cache__add_entry(cache, pev, tevs, ntevs) < 0 ||
2912 		    probe_cache__commit(cache) < 0)
2913 			pr_warning("Failed to add event to probe cache\n");
2914 		probe_cache__delete(cache);
2915 	}
2916 
2917 close_out:
2918 	for (up = 0; up < 2; up++) {
2919 		strlist__delete(namelist[up]);
2920 		if (fd[up] >= 0)
2921 			close(fd[up]);
2922 	}
2923 	return ret;
2924 }
2925 
find_probe_functions(struct map * map,char * name,struct symbol ** syms)2926 static int find_probe_functions(struct map *map, char *name,
2927 				struct symbol **syms)
2928 {
2929 	int found = 0;
2930 	struct symbol *sym;
2931 	struct rb_node *tmp;
2932 	const char *norm, *ver;
2933 	char *buf = NULL;
2934 	bool cut_version = true;
2935 
2936 	if (map__load(map) < 0)
2937 		return 0;
2938 
2939 	/* If user gives a version, don't cut off the version from symbols */
2940 	if (strchr(name, '@'))
2941 		cut_version = false;
2942 
2943 	map__for_each_symbol(map, sym, tmp) {
2944 		norm = arch__normalize_symbol_name(sym->name);
2945 		if (!norm)
2946 			continue;
2947 
2948 		if (cut_version) {
2949 			/* We don't care about default symbol or not */
2950 			ver = strchr(norm, '@');
2951 			if (ver) {
2952 				buf = strndup(norm, ver - norm);
2953 				if (!buf)
2954 					return -ENOMEM;
2955 				norm = buf;
2956 			}
2957 		}
2958 
2959 		if (strglobmatch(norm, name)) {
2960 			found++;
2961 			if (syms && found < probe_conf.max_probes)
2962 				syms[found - 1] = sym;
2963 		}
2964 		if (buf)
2965 			zfree(&buf);
2966 	}
2967 
2968 	return found;
2969 }
2970 
arch__fix_tev_from_maps(struct perf_probe_event * pev __maybe_unused,struct probe_trace_event * tev __maybe_unused,struct map * map __maybe_unused,struct symbol * sym __maybe_unused)2971 void __weak arch__fix_tev_from_maps(struct perf_probe_event *pev __maybe_unused,
2972 				struct probe_trace_event *tev __maybe_unused,
2973 				struct map *map __maybe_unused,
2974 				struct symbol *sym __maybe_unused) { }
2975 
2976 /*
2977  * Find probe function addresses from map.
2978  * Return an error or the number of found probe_trace_event
2979  */
find_probe_trace_events_from_map(struct perf_probe_event * pev,struct probe_trace_event ** tevs)2980 static int find_probe_trace_events_from_map(struct perf_probe_event *pev,
2981 					    struct probe_trace_event **tevs)
2982 {
2983 	struct map *map = NULL;
2984 	struct ref_reloc_sym *reloc_sym = NULL;
2985 	struct symbol *sym;
2986 	struct symbol **syms = NULL;
2987 	struct probe_trace_event *tev;
2988 	struct perf_probe_point *pp = &pev->point;
2989 	struct probe_trace_point *tp;
2990 	int num_matched_functions;
2991 	int ret, i, j, skipped = 0;
2992 	char *mod_name;
2993 
2994 	map = get_target_map(pev->target, pev->nsi, pev->uprobes);
2995 	if (!map) {
2996 		ret = -EINVAL;
2997 		goto out;
2998 	}
2999 
3000 	syms = malloc(sizeof(struct symbol *) * probe_conf.max_probes);
3001 	if (!syms) {
3002 		ret = -ENOMEM;
3003 		goto out;
3004 	}
3005 
3006 	/*
3007 	 * Load matched symbols: Since the different local symbols may have
3008 	 * same name but different addresses, this lists all the symbols.
3009 	 */
3010 	num_matched_functions = find_probe_functions(map, pp->function, syms);
3011 	if (num_matched_functions <= 0) {
3012 		pr_err("Failed to find symbol %s in %s\n", pp->function,
3013 			pev->target ? : "kernel");
3014 		ret = -ENOENT;
3015 		goto out;
3016 	} else if (num_matched_functions > probe_conf.max_probes) {
3017 		pr_err("Too many functions matched in %s\n",
3018 			pev->target ? : "kernel");
3019 		ret = -E2BIG;
3020 		goto out;
3021 	}
3022 
3023 	/* Note that the symbols in the kmodule are not relocated */
3024 	if (!pev->uprobes && !pev->target &&
3025 			(!pp->retprobe || kretprobe_offset_is_supported())) {
3026 		reloc_sym = kernel_get_ref_reloc_sym(NULL);
3027 		if (!reloc_sym) {
3028 			pr_warning("Relocated base symbol is not found!\n");
3029 			ret = -EINVAL;
3030 			goto out;
3031 		}
3032 	}
3033 
3034 	/* Setup result trace-probe-events */
3035 	*tevs = zalloc(sizeof(*tev) * num_matched_functions);
3036 	if (!*tevs) {
3037 		ret = -ENOMEM;
3038 		goto out;
3039 	}
3040 
3041 	ret = 0;
3042 
3043 	for (j = 0; j < num_matched_functions; j++) {
3044 		sym = syms[j];
3045 
3046 		/* There can be duplicated symbols in the map */
3047 		for (i = 0; i < j; i++)
3048 			if (sym->start == syms[i]->start) {
3049 				pr_debug("Found duplicated symbol %s @ %" PRIx64 "\n",
3050 					 sym->name, sym->start);
3051 				break;
3052 			}
3053 		if (i != j)
3054 			continue;
3055 
3056 		tev = (*tevs) + ret;
3057 		tp = &tev->point;
3058 		if (ret == num_matched_functions) {
3059 			pr_warning("Too many symbols are listed. Skip it.\n");
3060 			break;
3061 		}
3062 		ret++;
3063 
3064 		if (pp->offset > sym->end - sym->start) {
3065 			pr_warning("Offset %ld is bigger than the size of %s\n",
3066 				   pp->offset, sym->name);
3067 			ret = -ENOENT;
3068 			goto err_out;
3069 		}
3070 		/* Add one probe point */
3071 		tp->address = map->unmap_ip(map, sym->start) + pp->offset;
3072 
3073 		/* Check the kprobe (not in module) is within .text  */
3074 		if (!pev->uprobes && !pev->target &&
3075 		    kprobe_warn_out_range(sym->name, tp->address)) {
3076 			tp->symbol = NULL;	/* Skip it */
3077 			skipped++;
3078 		} else if (reloc_sym) {
3079 			tp->symbol = strdup_or_goto(reloc_sym->name, nomem_out);
3080 			tp->offset = tp->address - reloc_sym->addr;
3081 		} else {
3082 			tp->symbol = strdup_or_goto(sym->name, nomem_out);
3083 			tp->offset = pp->offset;
3084 		}
3085 		tp->realname = strdup_or_goto(sym->name, nomem_out);
3086 
3087 		tp->retprobe = pp->retprobe;
3088 		if (pev->target) {
3089 			if (pev->uprobes) {
3090 				tev->point.module = strdup_or_goto(pev->target,
3091 								   nomem_out);
3092 			} else {
3093 				mod_name = find_module_name(pev->target);
3094 				tev->point.module =
3095 					strdup(mod_name ? mod_name : pev->target);
3096 				free(mod_name);
3097 				if (!tev->point.module)
3098 					goto nomem_out;
3099 			}
3100 		}
3101 		tev->uprobes = pev->uprobes;
3102 		tev->nargs = pev->nargs;
3103 		if (tev->nargs) {
3104 			tev->args = zalloc(sizeof(struct probe_trace_arg) *
3105 					   tev->nargs);
3106 			if (tev->args == NULL)
3107 				goto nomem_out;
3108 		}
3109 		for (i = 0; i < tev->nargs; i++) {
3110 			if (pev->args[i].name)
3111 				tev->args[i].name =
3112 					strdup_or_goto(pev->args[i].name,
3113 							nomem_out);
3114 
3115 			tev->args[i].value = strdup_or_goto(pev->args[i].var,
3116 							    nomem_out);
3117 			if (pev->args[i].type)
3118 				tev->args[i].type =
3119 					strdup_or_goto(pev->args[i].type,
3120 							nomem_out);
3121 		}
3122 		arch__fix_tev_from_maps(pev, tev, map, sym);
3123 	}
3124 	if (ret == skipped) {
3125 		ret = -ENOENT;
3126 		goto err_out;
3127 	}
3128 
3129 out:
3130 	map__put(map);
3131 	free(syms);
3132 	return ret;
3133 
3134 nomem_out:
3135 	ret = -ENOMEM;
3136 err_out:
3137 	clear_probe_trace_events(*tevs, num_matched_functions);
3138 	zfree(tevs);
3139 	goto out;
3140 }
3141 
try_to_find_absolute_address(struct perf_probe_event * pev,struct probe_trace_event ** tevs)3142 static int try_to_find_absolute_address(struct perf_probe_event *pev,
3143 					struct probe_trace_event **tevs)
3144 {
3145 	struct perf_probe_point *pp = &pev->point;
3146 	struct probe_trace_event *tev;
3147 	struct probe_trace_point *tp;
3148 	int i, err;
3149 
3150 	if (!(pev->point.function && !strncmp(pev->point.function, "0x", 2)))
3151 		return -EINVAL;
3152 	if (perf_probe_event_need_dwarf(pev))
3153 		return -EINVAL;
3154 
3155 	/*
3156 	 * This is 'perf probe /lib/libc.so 0xabcd'. Try to probe at
3157 	 * absolute address.
3158 	 *
3159 	 * Only one tev can be generated by this.
3160 	 */
3161 	*tevs = zalloc(sizeof(*tev));
3162 	if (!*tevs)
3163 		return -ENOMEM;
3164 
3165 	tev = *tevs;
3166 	tp = &tev->point;
3167 
3168 	/*
3169 	 * Don't use tp->offset, use address directly, because
3170 	 * in synthesize_probe_trace_command() address cannot be
3171 	 * zero.
3172 	 */
3173 	tp->address = pev->point.abs_address;
3174 	tp->retprobe = pp->retprobe;
3175 	tev->uprobes = pev->uprobes;
3176 
3177 	err = -ENOMEM;
3178 	/*
3179 	 * Give it a '0x' leading symbol name.
3180 	 * In __add_probe_trace_events, a NULL symbol is interpreted as
3181 	 * invalid.
3182 	 */
3183 	if (asprintf(&tp->symbol, "0x%lx", tp->address) < 0)
3184 		goto errout;
3185 
3186 	/* For kprobe, check range */
3187 	if ((!tev->uprobes) &&
3188 	    (kprobe_warn_out_range(tev->point.symbol,
3189 				   tev->point.address))) {
3190 		err = -EACCES;
3191 		goto errout;
3192 	}
3193 
3194 	if (asprintf(&tp->realname, "abs_%lx", tp->address) < 0)
3195 		goto errout;
3196 
3197 	if (pev->target) {
3198 		tp->module = strdup(pev->target);
3199 		if (!tp->module)
3200 			goto errout;
3201 	}
3202 
3203 	if (tev->group) {
3204 		tev->group = strdup(pev->group);
3205 		if (!tev->group)
3206 			goto errout;
3207 	}
3208 
3209 	if (pev->event) {
3210 		tev->event = strdup(pev->event);
3211 		if (!tev->event)
3212 			goto errout;
3213 	}
3214 
3215 	tev->nargs = pev->nargs;
3216 	tev->args = zalloc(sizeof(struct probe_trace_arg) * tev->nargs);
3217 	if (!tev->args)
3218 		goto errout;
3219 
3220 	for (i = 0; i < tev->nargs; i++)
3221 		copy_to_probe_trace_arg(&tev->args[i], &pev->args[i]);
3222 
3223 	return 1;
3224 
3225 errout:
3226 	clear_probe_trace_events(*tevs, 1);
3227 	*tevs = NULL;
3228 	return err;
3229 }
3230 
3231 /* Concatenate two arrays */
memcat(void * a,size_t sz_a,void * b,size_t sz_b)3232 static void *memcat(void *a, size_t sz_a, void *b, size_t sz_b)
3233 {
3234 	void *ret;
3235 
3236 	ret = malloc(sz_a + sz_b);
3237 	if (ret) {
3238 		memcpy(ret, a, sz_a);
3239 		memcpy(ret + sz_a, b, sz_b);
3240 	}
3241 	return ret;
3242 }
3243 
3244 static int
concat_probe_trace_events(struct probe_trace_event ** tevs,int * ntevs,struct probe_trace_event ** tevs2,int ntevs2)3245 concat_probe_trace_events(struct probe_trace_event **tevs, int *ntevs,
3246 			  struct probe_trace_event **tevs2, int ntevs2)
3247 {
3248 	struct probe_trace_event *new_tevs;
3249 	int ret = 0;
3250 
3251 	if (*ntevs == 0) {
3252 		*tevs = *tevs2;
3253 		*ntevs = ntevs2;
3254 		*tevs2 = NULL;
3255 		return 0;
3256 	}
3257 
3258 	if (*ntevs + ntevs2 > probe_conf.max_probes)
3259 		ret = -E2BIG;
3260 	else {
3261 		/* Concatenate the array of probe_trace_event */
3262 		new_tevs = memcat(*tevs, (*ntevs) * sizeof(**tevs),
3263 				  *tevs2, ntevs2 * sizeof(**tevs2));
3264 		if (!new_tevs)
3265 			ret = -ENOMEM;
3266 		else {
3267 			free(*tevs);
3268 			*tevs = new_tevs;
3269 			*ntevs += ntevs2;
3270 		}
3271 	}
3272 	if (ret < 0)
3273 		clear_probe_trace_events(*tevs2, ntevs2);
3274 	zfree(tevs2);
3275 
3276 	return ret;
3277 }
3278 
3279 /*
3280  * Try to find probe_trace_event from given probe caches. Return the number
3281  * of cached events found, if an error occurs return the error.
3282  */
find_cached_events(struct perf_probe_event * pev,struct probe_trace_event ** tevs,const char * target)3283 static int find_cached_events(struct perf_probe_event *pev,
3284 			      struct probe_trace_event **tevs,
3285 			      const char *target)
3286 {
3287 	struct probe_cache *cache;
3288 	struct probe_cache_entry *entry;
3289 	struct probe_trace_event *tmp_tevs = NULL;
3290 	int ntevs = 0;
3291 	int ret = 0;
3292 
3293 	cache = probe_cache__new(target, pev->nsi);
3294 	/* Return 0 ("not found") if the target has no probe cache. */
3295 	if (!cache)
3296 		return 0;
3297 
3298 	for_each_probe_cache_entry(entry, cache) {
3299 		/* Skip the cache entry which has no name */
3300 		if (!entry->pev.event || !entry->pev.group)
3301 			continue;
3302 		if ((!pev->group || strglobmatch(entry->pev.group, pev->group)) &&
3303 		    strglobmatch(entry->pev.event, pev->event)) {
3304 			ret = probe_cache_entry__get_event(entry, &tmp_tevs);
3305 			if (ret > 0)
3306 				ret = concat_probe_trace_events(tevs, &ntevs,
3307 								&tmp_tevs, ret);
3308 			if (ret < 0)
3309 				break;
3310 		}
3311 	}
3312 	probe_cache__delete(cache);
3313 	if (ret < 0) {
3314 		clear_probe_trace_events(*tevs, ntevs);
3315 		zfree(tevs);
3316 	} else {
3317 		ret = ntevs;
3318 		if (ntevs > 0 && target && target[0] == '/')
3319 			pev->uprobes = true;
3320 	}
3321 
3322 	return ret;
3323 }
3324 
3325 /* Try to find probe_trace_event from all probe caches */
find_cached_events_all(struct perf_probe_event * pev,struct probe_trace_event ** tevs)3326 static int find_cached_events_all(struct perf_probe_event *pev,
3327 				   struct probe_trace_event **tevs)
3328 {
3329 	struct probe_trace_event *tmp_tevs = NULL;
3330 	struct strlist *bidlist;
3331 	struct str_node *nd;
3332 	char *pathname;
3333 	int ntevs = 0;
3334 	int ret;
3335 
3336 	/* Get the buildid list of all valid caches */
3337 	bidlist = build_id_cache__list_all(true);
3338 	if (!bidlist) {
3339 		ret = -errno;
3340 		pr_debug("Failed to get buildids: %d\n", ret);
3341 		return ret;
3342 	}
3343 
3344 	ret = 0;
3345 	strlist__for_each_entry(nd, bidlist) {
3346 		pathname = build_id_cache__origname(nd->s);
3347 		ret = find_cached_events(pev, &tmp_tevs, pathname);
3348 		/* In the case of cnt == 0, we just skip it */
3349 		if (ret > 0)
3350 			ret = concat_probe_trace_events(tevs, &ntevs,
3351 							&tmp_tevs, ret);
3352 		free(pathname);
3353 		if (ret < 0)
3354 			break;
3355 	}
3356 	strlist__delete(bidlist);
3357 
3358 	if (ret < 0) {
3359 		clear_probe_trace_events(*tevs, ntevs);
3360 		zfree(tevs);
3361 	} else
3362 		ret = ntevs;
3363 
3364 	return ret;
3365 }
3366 
find_probe_trace_events_from_cache(struct perf_probe_event * pev,struct probe_trace_event ** tevs)3367 static int find_probe_trace_events_from_cache(struct perf_probe_event *pev,
3368 					      struct probe_trace_event **tevs)
3369 {
3370 	struct probe_cache *cache;
3371 	struct probe_cache_entry *entry;
3372 	struct probe_trace_event *tev;
3373 	struct str_node *node;
3374 	int ret, i;
3375 
3376 	if (pev->sdt) {
3377 		/* For SDT/cached events, we use special search functions */
3378 		if (!pev->target)
3379 			return find_cached_events_all(pev, tevs);
3380 		else
3381 			return find_cached_events(pev, tevs, pev->target);
3382 	}
3383 	cache = probe_cache__new(pev->target, pev->nsi);
3384 	if (!cache)
3385 		return 0;
3386 
3387 	entry = probe_cache__find(cache, pev);
3388 	if (!entry) {
3389 		/* SDT must be in the cache */
3390 		ret = pev->sdt ? -ENOENT : 0;
3391 		goto out;
3392 	}
3393 
3394 	ret = strlist__nr_entries(entry->tevlist);
3395 	if (ret > probe_conf.max_probes) {
3396 		pr_debug("Too many entries matched in the cache of %s\n",
3397 			 pev->target ? : "kernel");
3398 		ret = -E2BIG;
3399 		goto out;
3400 	}
3401 
3402 	*tevs = zalloc(ret * sizeof(*tev));
3403 	if (!*tevs) {
3404 		ret = -ENOMEM;
3405 		goto out;
3406 	}
3407 
3408 	i = 0;
3409 	strlist__for_each_entry(node, entry->tevlist) {
3410 		tev = &(*tevs)[i++];
3411 		ret = parse_probe_trace_command(node->s, tev);
3412 		if (ret < 0)
3413 			goto out;
3414 		/* Set the uprobes attribute as same as original */
3415 		tev->uprobes = pev->uprobes;
3416 	}
3417 	ret = i;
3418 
3419 out:
3420 	probe_cache__delete(cache);
3421 	return ret;
3422 }
3423 
convert_to_probe_trace_events(struct perf_probe_event * pev,struct probe_trace_event ** tevs)3424 static int convert_to_probe_trace_events(struct perf_probe_event *pev,
3425 					 struct probe_trace_event **tevs)
3426 {
3427 	int ret;
3428 
3429 	if (!pev->group && !pev->sdt) {
3430 		/* Set group name if not given */
3431 		if (!pev->uprobes) {
3432 			pev->group = strdup(PERFPROBE_GROUP);
3433 			ret = pev->group ? 0 : -ENOMEM;
3434 		} else
3435 			ret = convert_exec_to_group(pev->target, &pev->group);
3436 		if (ret != 0) {
3437 			pr_warning("Failed to make a group name.\n");
3438 			return ret;
3439 		}
3440 	}
3441 
3442 	ret = try_to_find_absolute_address(pev, tevs);
3443 	if (ret > 0)
3444 		return ret;
3445 
3446 	/* At first, we need to lookup cache entry */
3447 	ret = find_probe_trace_events_from_cache(pev, tevs);
3448 	if (ret > 0 || pev->sdt)	/* SDT can be found only in the cache */
3449 		return ret == 0 ? -ENOENT : ret; /* Found in probe cache */
3450 
3451 	/* Convert perf_probe_event with debuginfo */
3452 	ret = try_to_find_probe_trace_events(pev, tevs);
3453 	if (ret != 0)
3454 		return ret;	/* Found in debuginfo or got an error */
3455 
3456 	return find_probe_trace_events_from_map(pev, tevs);
3457 }
3458 
convert_perf_probe_events(struct perf_probe_event * pevs,int npevs)3459 int convert_perf_probe_events(struct perf_probe_event *pevs, int npevs)
3460 {
3461 	int i, ret;
3462 
3463 	/* Loop 1: convert all events */
3464 	for (i = 0; i < npevs; i++) {
3465 		/* Init kprobe blacklist if needed */
3466 		if (!pevs[i].uprobes)
3467 			kprobe_blacklist__init();
3468 		/* Convert with or without debuginfo */
3469 		ret  = convert_to_probe_trace_events(&pevs[i], &pevs[i].tevs);
3470 		if (ret < 0)
3471 			return ret;
3472 		pevs[i].ntevs = ret;
3473 	}
3474 	/* This just release blacklist only if allocated */
3475 	kprobe_blacklist__release();
3476 
3477 	return 0;
3478 }
3479 
show_probe_trace_event(struct probe_trace_event * tev)3480 static int show_probe_trace_event(struct probe_trace_event *tev)
3481 {
3482 	char *buf = synthesize_probe_trace_command(tev);
3483 
3484 	if (!buf) {
3485 		pr_debug("Failed to synthesize probe trace event.\n");
3486 		return -EINVAL;
3487 	}
3488 
3489 	/* Showing definition always go stdout */
3490 	printf("%s\n", buf);
3491 	free(buf);
3492 
3493 	return 0;
3494 }
3495 
show_probe_trace_events(struct perf_probe_event * pevs,int npevs)3496 int show_probe_trace_events(struct perf_probe_event *pevs, int npevs)
3497 {
3498 	struct strlist *namelist = strlist__new(NULL, NULL);
3499 	struct probe_trace_event *tev;
3500 	struct perf_probe_event *pev;
3501 	int i, j, ret = 0;
3502 
3503 	if (!namelist)
3504 		return -ENOMEM;
3505 
3506 	for (j = 0; j < npevs && !ret; j++) {
3507 		pev = &pevs[j];
3508 		for (i = 0; i < pev->ntevs && !ret; i++) {
3509 			tev = &pev->tevs[i];
3510 			/* Skip if the symbol is out of .text or blacklisted */
3511 			if (!tev->point.symbol && !pev->uprobes)
3512 				continue;
3513 
3514 			/* Set new name for tev (and update namelist) */
3515 			ret = probe_trace_event__set_name(tev, pev,
3516 							  namelist, true);
3517 			if (!ret)
3518 				ret = show_probe_trace_event(tev);
3519 		}
3520 	}
3521 	strlist__delete(namelist);
3522 
3523 	return ret;
3524 }
3525 
apply_perf_probe_events(struct perf_probe_event * pevs,int npevs)3526 int apply_perf_probe_events(struct perf_probe_event *pevs, int npevs)
3527 {
3528 	int i, ret = 0;
3529 
3530 	/* Loop 2: add all events */
3531 	for (i = 0; i < npevs; i++) {
3532 		ret = __add_probe_trace_events(&pevs[i], pevs[i].tevs,
3533 					       pevs[i].ntevs,
3534 					       probe_conf.force_add);
3535 		if (ret < 0)
3536 			break;
3537 	}
3538 	return ret;
3539 }
3540 
cleanup_perf_probe_events(struct perf_probe_event * pevs,int npevs)3541 void cleanup_perf_probe_events(struct perf_probe_event *pevs, int npevs)
3542 {
3543 	int i, j;
3544 	struct perf_probe_event *pev;
3545 
3546 	/* Loop 3: cleanup and free trace events  */
3547 	for (i = 0; i < npevs; i++) {
3548 		pev = &pevs[i];
3549 		for (j = 0; j < pevs[i].ntevs; j++)
3550 			clear_probe_trace_event(&pevs[i].tevs[j]);
3551 		zfree(&pevs[i].tevs);
3552 		pevs[i].ntevs = 0;
3553 		nsinfo__zput(pev->nsi);
3554 		clear_perf_probe_event(&pevs[i]);
3555 	}
3556 }
3557 
add_perf_probe_events(struct perf_probe_event * pevs,int npevs)3558 int add_perf_probe_events(struct perf_probe_event *pevs, int npevs)
3559 {
3560 	int ret;
3561 
3562 	ret = init_probe_symbol_maps(pevs->uprobes);
3563 	if (ret < 0)
3564 		return ret;
3565 
3566 	ret = convert_perf_probe_events(pevs, npevs);
3567 	if (ret == 0)
3568 		ret = apply_perf_probe_events(pevs, npevs);
3569 
3570 	cleanup_perf_probe_events(pevs, npevs);
3571 
3572 	exit_probe_symbol_maps();
3573 	return ret;
3574 }
3575 
del_perf_probe_events(struct strfilter * filter)3576 int del_perf_probe_events(struct strfilter *filter)
3577 {
3578 	int ret, ret2, ufd = -1, kfd = -1;
3579 	char *str = strfilter__string(filter);
3580 
3581 	if (!str)
3582 		return -EINVAL;
3583 
3584 	/* Get current event names */
3585 	ret = probe_file__open_both(&kfd, &ufd, PF_FL_RW);
3586 	if (ret < 0)
3587 		goto out;
3588 
3589 	ret = probe_file__del_events(kfd, filter);
3590 	if (ret < 0 && ret != -ENOENT)
3591 		goto error;
3592 
3593 	ret2 = probe_file__del_events(ufd, filter);
3594 	if (ret2 < 0 && ret2 != -ENOENT) {
3595 		ret = ret2;
3596 		goto error;
3597 	}
3598 	ret = 0;
3599 
3600 error:
3601 	if (kfd >= 0)
3602 		close(kfd);
3603 	if (ufd >= 0)
3604 		close(ufd);
3605 out:
3606 	free(str);
3607 
3608 	return ret;
3609 }
3610 
show_available_funcs(const char * target,struct nsinfo * nsi,struct strfilter * _filter,bool user)3611 int show_available_funcs(const char *target, struct nsinfo *nsi,
3612 			 struct strfilter *_filter, bool user)
3613 {
3614         struct rb_node *nd;
3615 	struct map *map;
3616 	int ret;
3617 
3618 	ret = init_probe_symbol_maps(user);
3619 	if (ret < 0)
3620 		return ret;
3621 
3622 	/* Get a symbol map */
3623 	map = get_target_map(target, nsi, user);
3624 	if (!map) {
3625 		pr_err("Failed to get a map for %s\n", (target) ? : "kernel");
3626 		return -EINVAL;
3627 	}
3628 
3629 	ret = map__load(map);
3630 	if (ret) {
3631 		if (ret == -2) {
3632 			char *str = strfilter__string(_filter);
3633 			pr_err("Failed to find symbols matched to \"%s\"\n",
3634 			       str);
3635 			free(str);
3636 		} else
3637 			pr_err("Failed to load symbols in %s\n",
3638 			       (target) ? : "kernel");
3639 		goto end;
3640 	}
3641 	if (!dso__sorted_by_name(map->dso))
3642 		dso__sort_by_name(map->dso);
3643 
3644 	/* Show all (filtered) symbols */
3645 	setup_pager();
3646 
3647 	for (nd = rb_first_cached(&map->dso->symbol_names); nd;
3648 	     nd = rb_next(nd)) {
3649 		struct symbol_name_rb_node *pos = rb_entry(nd, struct symbol_name_rb_node, rb_node);
3650 
3651 		if (strfilter__compare(_filter, pos->sym.name))
3652 			printf("%s\n", pos->sym.name);
3653 	}
3654 end:
3655 	map__put(map);
3656 	exit_probe_symbol_maps();
3657 
3658 	return ret;
3659 }
3660 
copy_to_probe_trace_arg(struct probe_trace_arg * tvar,struct perf_probe_arg * pvar)3661 int copy_to_probe_trace_arg(struct probe_trace_arg *tvar,
3662 			    struct perf_probe_arg *pvar)
3663 {
3664 	tvar->value = strdup(pvar->var);
3665 	if (tvar->value == NULL)
3666 		return -ENOMEM;
3667 	if (pvar->type) {
3668 		tvar->type = strdup(pvar->type);
3669 		if (tvar->type == NULL)
3670 			return -ENOMEM;
3671 	}
3672 	if (pvar->name) {
3673 		tvar->name = strdup(pvar->name);
3674 		if (tvar->name == NULL)
3675 			return -ENOMEM;
3676 	} else
3677 		tvar->name = NULL;
3678 	return 0;
3679 }
3680