xref: /linux/tools/perf/util/evsel.c (revision d060296cc0300ae8ed08004ebd3994bf325fa257)
1 /*
2  * Copyright (C) 2011, Red Hat Inc, Arnaldo Carvalho de Melo <acme@redhat.com>
3  *
4  * Parts came from builtin-{top,stat,record}.c, see those files for further
5  * copyright notes.
6  *
7  * Released under the GPL v2. (and only v2, not any later version)
8  */
9 
10 #include <byteswap.h>
11 #include <errno.h>
12 #include <inttypes.h>
13 #include <linux/bitops.h>
14 #include <api/fs/fs.h>
15 #include <api/fs/tracing_path.h>
16 #include <traceevent/event-parse.h>
17 #include <linux/hw_breakpoint.h>
18 #include <linux/perf_event.h>
19 #include <linux/compiler.h>
20 #include <linux/err.h>
21 #include <sys/ioctl.h>
22 #include <sys/resource.h>
23 #include <sys/types.h>
24 #include <dirent.h>
25 #include "asm/bug.h"
26 #include "callchain.h"
27 #include "cgroup.h"
28 #include "event.h"
29 #include "evsel.h"
30 #include "evlist.h"
31 #include "util.h"
32 #include "cpumap.h"
33 #include "thread_map.h"
34 #include "target.h"
35 #include "perf_regs.h"
36 #include "debug.h"
37 #include "trace-event.h"
38 #include "stat.h"
39 #include "util/parse-branch-options.h"
40 
41 #include "sane_ctype.h"
42 
43 static struct {
44 	bool sample_id_all;
45 	bool exclude_guest;
46 	bool mmap2;
47 	bool cloexec;
48 	bool clockid;
49 	bool clockid_wrong;
50 	bool lbr_flags;
51 	bool write_backward;
52 } perf_missing_features;
53 
54 static clockid_t clockid;
55 
56 static int perf_evsel__no_extra_init(struct perf_evsel *evsel __maybe_unused)
57 {
58 	return 0;
59 }
60 
61 static void perf_evsel__no_extra_fini(struct perf_evsel *evsel __maybe_unused)
62 {
63 }
64 
65 static struct {
66 	size_t	size;
67 	int	(*init)(struct perf_evsel *evsel);
68 	void	(*fini)(struct perf_evsel *evsel);
69 } perf_evsel__object = {
70 	.size = sizeof(struct perf_evsel),
71 	.init = perf_evsel__no_extra_init,
72 	.fini = perf_evsel__no_extra_fini,
73 };
74 
75 int perf_evsel__object_config(size_t object_size,
76 			      int (*init)(struct perf_evsel *evsel),
77 			      void (*fini)(struct perf_evsel *evsel))
78 {
79 
80 	if (object_size == 0)
81 		goto set_methods;
82 
83 	if (perf_evsel__object.size > object_size)
84 		return -EINVAL;
85 
86 	perf_evsel__object.size = object_size;
87 
88 set_methods:
89 	if (init != NULL)
90 		perf_evsel__object.init = init;
91 
92 	if (fini != NULL)
93 		perf_evsel__object.fini = fini;
94 
95 	return 0;
96 }
97 
98 #define FD(e, x, y) (*(int *)xyarray__entry(e->fd, x, y))
99 
100 int __perf_evsel__sample_size(u64 sample_type)
101 {
102 	u64 mask = sample_type & PERF_SAMPLE_MASK;
103 	int size = 0;
104 	int i;
105 
106 	for (i = 0; i < 64; i++) {
107 		if (mask & (1ULL << i))
108 			size++;
109 	}
110 
111 	size *= sizeof(u64);
112 
113 	return size;
114 }
115 
116 /**
117  * __perf_evsel__calc_id_pos - calculate id_pos.
118  * @sample_type: sample type
119  *
120  * This function returns the position of the event id (PERF_SAMPLE_ID or
121  * PERF_SAMPLE_IDENTIFIER) in a sample event i.e. in the array of struct
122  * sample_event.
123  */
124 static int __perf_evsel__calc_id_pos(u64 sample_type)
125 {
126 	int idx = 0;
127 
128 	if (sample_type & PERF_SAMPLE_IDENTIFIER)
129 		return 0;
130 
131 	if (!(sample_type & PERF_SAMPLE_ID))
132 		return -1;
133 
134 	if (sample_type & PERF_SAMPLE_IP)
135 		idx += 1;
136 
137 	if (sample_type & PERF_SAMPLE_TID)
138 		idx += 1;
139 
140 	if (sample_type & PERF_SAMPLE_TIME)
141 		idx += 1;
142 
143 	if (sample_type & PERF_SAMPLE_ADDR)
144 		idx += 1;
145 
146 	return idx;
147 }
148 
149 /**
150  * __perf_evsel__calc_is_pos - calculate is_pos.
151  * @sample_type: sample type
152  *
153  * This function returns the position (counting backwards) of the event id
154  * (PERF_SAMPLE_ID or PERF_SAMPLE_IDENTIFIER) in a non-sample event i.e. if
155  * sample_id_all is used there is an id sample appended to non-sample events.
156  */
157 static int __perf_evsel__calc_is_pos(u64 sample_type)
158 {
159 	int idx = 1;
160 
161 	if (sample_type & PERF_SAMPLE_IDENTIFIER)
162 		return 1;
163 
164 	if (!(sample_type & PERF_SAMPLE_ID))
165 		return -1;
166 
167 	if (sample_type & PERF_SAMPLE_CPU)
168 		idx += 1;
169 
170 	if (sample_type & PERF_SAMPLE_STREAM_ID)
171 		idx += 1;
172 
173 	return idx;
174 }
175 
176 void perf_evsel__calc_id_pos(struct perf_evsel *evsel)
177 {
178 	evsel->id_pos = __perf_evsel__calc_id_pos(evsel->attr.sample_type);
179 	evsel->is_pos = __perf_evsel__calc_is_pos(evsel->attr.sample_type);
180 }
181 
182 void __perf_evsel__set_sample_bit(struct perf_evsel *evsel,
183 				  enum perf_event_sample_format bit)
184 {
185 	if (!(evsel->attr.sample_type & bit)) {
186 		evsel->attr.sample_type |= bit;
187 		evsel->sample_size += sizeof(u64);
188 		perf_evsel__calc_id_pos(evsel);
189 	}
190 }
191 
192 void __perf_evsel__reset_sample_bit(struct perf_evsel *evsel,
193 				    enum perf_event_sample_format bit)
194 {
195 	if (evsel->attr.sample_type & bit) {
196 		evsel->attr.sample_type &= ~bit;
197 		evsel->sample_size -= sizeof(u64);
198 		perf_evsel__calc_id_pos(evsel);
199 	}
200 }
201 
202 void perf_evsel__set_sample_id(struct perf_evsel *evsel,
203 			       bool can_sample_identifier)
204 {
205 	if (can_sample_identifier) {
206 		perf_evsel__reset_sample_bit(evsel, ID);
207 		perf_evsel__set_sample_bit(evsel, IDENTIFIER);
208 	} else {
209 		perf_evsel__set_sample_bit(evsel, ID);
210 	}
211 	evsel->attr.read_format |= PERF_FORMAT_ID;
212 }
213 
214 /**
215  * perf_evsel__is_function_event - Return whether given evsel is a function
216  * trace event
217  *
218  * @evsel - evsel selector to be tested
219  *
220  * Return %true if event is function trace event
221  */
222 bool perf_evsel__is_function_event(struct perf_evsel *evsel)
223 {
224 #define FUNCTION_EVENT "ftrace:function"
225 
226 	return evsel->name &&
227 	       !strncmp(FUNCTION_EVENT, evsel->name, sizeof(FUNCTION_EVENT));
228 
229 #undef FUNCTION_EVENT
230 }
231 
232 void perf_evsel__init(struct perf_evsel *evsel,
233 		      struct perf_event_attr *attr, int idx)
234 {
235 	evsel->idx	   = idx;
236 	evsel->tracking	   = !idx;
237 	evsel->attr	   = *attr;
238 	evsel->leader	   = evsel;
239 	evsel->unit	   = "";
240 	evsel->scale	   = 1.0;
241 	evsel->evlist	   = NULL;
242 	evsel->bpf_fd	   = -1;
243 	INIT_LIST_HEAD(&evsel->node);
244 	INIT_LIST_HEAD(&evsel->config_terms);
245 	perf_evsel__object.init(evsel);
246 	evsel->sample_size = __perf_evsel__sample_size(attr->sample_type);
247 	perf_evsel__calc_id_pos(evsel);
248 	evsel->cmdline_group_boundary = false;
249 	evsel->metric_expr   = NULL;
250 	evsel->metric_name   = NULL;
251 	evsel->metric_events = NULL;
252 	evsel->collect_stat  = false;
253 }
254 
255 struct perf_evsel *perf_evsel__new_idx(struct perf_event_attr *attr, int idx)
256 {
257 	struct perf_evsel *evsel = zalloc(perf_evsel__object.size);
258 
259 	if (evsel != NULL)
260 		perf_evsel__init(evsel, attr, idx);
261 
262 	if (perf_evsel__is_bpf_output(evsel)) {
263 		evsel->attr.sample_type |= (PERF_SAMPLE_RAW | PERF_SAMPLE_TIME |
264 					    PERF_SAMPLE_CPU | PERF_SAMPLE_PERIOD),
265 		evsel->attr.sample_period = 1;
266 	}
267 
268 	return evsel;
269 }
270 
271 struct perf_evsel *perf_evsel__new_cycles(void)
272 {
273 	struct perf_event_attr attr = {
274 		.type	= PERF_TYPE_HARDWARE,
275 		.config	= PERF_COUNT_HW_CPU_CYCLES,
276 		.exclude_kernel	= geteuid() != 0,
277 	};
278 	struct perf_evsel *evsel;
279 
280 	event_attr_init(&attr);
281 	/*
282 	 * Unnamed union member, not supported as struct member named
283 	 * initializer in older compilers such as gcc 4.4.7
284 	 *
285 	 * Just for probing the precise_ip:
286 	 */
287 	attr.sample_period = 1;
288 
289 	perf_event_attr__set_max_precise_ip(&attr);
290 	/*
291 	 * Now let the usual logic to set up the perf_event_attr defaults
292 	 * to kick in when we return and before perf_evsel__open() is called.
293 	 */
294 	attr.sample_period = 0;
295 
296 	evsel = perf_evsel__new(&attr);
297 	if (evsel == NULL)
298 		goto out;
299 
300 	/* use asprintf() because free(evsel) assumes name is allocated */
301 	if (asprintf(&evsel->name, "cycles%s%s%.*s",
302 		     (attr.precise_ip || attr.exclude_kernel) ? ":" : "",
303 		     attr.exclude_kernel ? "u" : "",
304 		     attr.precise_ip ? attr.precise_ip + 1 : 0, "ppp") < 0)
305 		goto error_free;
306 out:
307 	return evsel;
308 error_free:
309 	perf_evsel__delete(evsel);
310 	evsel = NULL;
311 	goto out;
312 }
313 
314 /*
315  * Returns pointer with encoded error via <linux/err.h> interface.
316  */
317 struct perf_evsel *perf_evsel__newtp_idx(const char *sys, const char *name, int idx)
318 {
319 	struct perf_evsel *evsel = zalloc(perf_evsel__object.size);
320 	int err = -ENOMEM;
321 
322 	if (evsel == NULL) {
323 		goto out_err;
324 	} else {
325 		struct perf_event_attr attr = {
326 			.type	       = PERF_TYPE_TRACEPOINT,
327 			.sample_type   = (PERF_SAMPLE_RAW | PERF_SAMPLE_TIME |
328 					  PERF_SAMPLE_CPU | PERF_SAMPLE_PERIOD),
329 		};
330 
331 		if (asprintf(&evsel->name, "%s:%s", sys, name) < 0)
332 			goto out_free;
333 
334 		evsel->tp_format = trace_event__tp_format(sys, name);
335 		if (IS_ERR(evsel->tp_format)) {
336 			err = PTR_ERR(evsel->tp_format);
337 			goto out_free;
338 		}
339 
340 		event_attr_init(&attr);
341 		attr.config = evsel->tp_format->id;
342 		attr.sample_period = 1;
343 		perf_evsel__init(evsel, &attr, idx);
344 	}
345 
346 	return evsel;
347 
348 out_free:
349 	zfree(&evsel->name);
350 	free(evsel);
351 out_err:
352 	return ERR_PTR(err);
353 }
354 
355 const char *perf_evsel__hw_names[PERF_COUNT_HW_MAX] = {
356 	"cycles",
357 	"instructions",
358 	"cache-references",
359 	"cache-misses",
360 	"branches",
361 	"branch-misses",
362 	"bus-cycles",
363 	"stalled-cycles-frontend",
364 	"stalled-cycles-backend",
365 	"ref-cycles",
366 };
367 
368 static const char *__perf_evsel__hw_name(u64 config)
369 {
370 	if (config < PERF_COUNT_HW_MAX && perf_evsel__hw_names[config])
371 		return perf_evsel__hw_names[config];
372 
373 	return "unknown-hardware";
374 }
375 
376 static int perf_evsel__add_modifiers(struct perf_evsel *evsel, char *bf, size_t size)
377 {
378 	int colon = 0, r = 0;
379 	struct perf_event_attr *attr = &evsel->attr;
380 	bool exclude_guest_default = false;
381 
382 #define MOD_PRINT(context, mod)	do {					\
383 		if (!attr->exclude_##context) {				\
384 			if (!colon) colon = ++r;			\
385 			r += scnprintf(bf + r, size - r, "%c", mod);	\
386 		} } while(0)
387 
388 	if (attr->exclude_kernel || attr->exclude_user || attr->exclude_hv) {
389 		MOD_PRINT(kernel, 'k');
390 		MOD_PRINT(user, 'u');
391 		MOD_PRINT(hv, 'h');
392 		exclude_guest_default = true;
393 	}
394 
395 	if (attr->precise_ip) {
396 		if (!colon)
397 			colon = ++r;
398 		r += scnprintf(bf + r, size - r, "%.*s", attr->precise_ip, "ppp");
399 		exclude_guest_default = true;
400 	}
401 
402 	if (attr->exclude_host || attr->exclude_guest == exclude_guest_default) {
403 		MOD_PRINT(host, 'H');
404 		MOD_PRINT(guest, 'G');
405 	}
406 #undef MOD_PRINT
407 	if (colon)
408 		bf[colon - 1] = ':';
409 	return r;
410 }
411 
412 static int perf_evsel__hw_name(struct perf_evsel *evsel, char *bf, size_t size)
413 {
414 	int r = scnprintf(bf, size, "%s", __perf_evsel__hw_name(evsel->attr.config));
415 	return r + perf_evsel__add_modifiers(evsel, bf + r, size - r);
416 }
417 
418 const char *perf_evsel__sw_names[PERF_COUNT_SW_MAX] = {
419 	"cpu-clock",
420 	"task-clock",
421 	"page-faults",
422 	"context-switches",
423 	"cpu-migrations",
424 	"minor-faults",
425 	"major-faults",
426 	"alignment-faults",
427 	"emulation-faults",
428 	"dummy",
429 };
430 
431 static const char *__perf_evsel__sw_name(u64 config)
432 {
433 	if (config < PERF_COUNT_SW_MAX && perf_evsel__sw_names[config])
434 		return perf_evsel__sw_names[config];
435 	return "unknown-software";
436 }
437 
438 static int perf_evsel__sw_name(struct perf_evsel *evsel, char *bf, size_t size)
439 {
440 	int r = scnprintf(bf, size, "%s", __perf_evsel__sw_name(evsel->attr.config));
441 	return r + perf_evsel__add_modifiers(evsel, bf + r, size - r);
442 }
443 
444 static int __perf_evsel__bp_name(char *bf, size_t size, u64 addr, u64 type)
445 {
446 	int r;
447 
448 	r = scnprintf(bf, size, "mem:0x%" PRIx64 ":", addr);
449 
450 	if (type & HW_BREAKPOINT_R)
451 		r += scnprintf(bf + r, size - r, "r");
452 
453 	if (type & HW_BREAKPOINT_W)
454 		r += scnprintf(bf + r, size - r, "w");
455 
456 	if (type & HW_BREAKPOINT_X)
457 		r += scnprintf(bf + r, size - r, "x");
458 
459 	return r;
460 }
461 
462 static int perf_evsel__bp_name(struct perf_evsel *evsel, char *bf, size_t size)
463 {
464 	struct perf_event_attr *attr = &evsel->attr;
465 	int r = __perf_evsel__bp_name(bf, size, attr->bp_addr, attr->bp_type);
466 	return r + perf_evsel__add_modifiers(evsel, bf + r, size - r);
467 }
468 
469 const char *perf_evsel__hw_cache[PERF_COUNT_HW_CACHE_MAX]
470 				[PERF_EVSEL__MAX_ALIASES] = {
471  { "L1-dcache",	"l1-d",		"l1d",		"L1-data",		},
472  { "L1-icache",	"l1-i",		"l1i",		"L1-instruction",	},
473  { "LLC",	"L2",							},
474  { "dTLB",	"d-tlb",	"Data-TLB",				},
475  { "iTLB",	"i-tlb",	"Instruction-TLB",			},
476  { "branch",	"branches",	"bpu",		"btb",		"bpc",	},
477  { "node",								},
478 };
479 
480 const char *perf_evsel__hw_cache_op[PERF_COUNT_HW_CACHE_OP_MAX]
481 				   [PERF_EVSEL__MAX_ALIASES] = {
482  { "load",	"loads",	"read",					},
483  { "store",	"stores",	"write",				},
484  { "prefetch",	"prefetches",	"speculative-read", "speculative-load",	},
485 };
486 
487 const char *perf_evsel__hw_cache_result[PERF_COUNT_HW_CACHE_RESULT_MAX]
488 				       [PERF_EVSEL__MAX_ALIASES] = {
489  { "refs",	"Reference",	"ops",		"access",		},
490  { "misses",	"miss",							},
491 };
492 
493 #define C(x)		PERF_COUNT_HW_CACHE_##x
494 #define CACHE_READ	(1 << C(OP_READ))
495 #define CACHE_WRITE	(1 << C(OP_WRITE))
496 #define CACHE_PREFETCH	(1 << C(OP_PREFETCH))
497 #define COP(x)		(1 << x)
498 
499 /*
500  * cache operartion stat
501  * L1I : Read and prefetch only
502  * ITLB and BPU : Read-only
503  */
504 static unsigned long perf_evsel__hw_cache_stat[C(MAX)] = {
505  [C(L1D)]	= (CACHE_READ | CACHE_WRITE | CACHE_PREFETCH),
506  [C(L1I)]	= (CACHE_READ | CACHE_PREFETCH),
507  [C(LL)]	= (CACHE_READ | CACHE_WRITE | CACHE_PREFETCH),
508  [C(DTLB)]	= (CACHE_READ | CACHE_WRITE | CACHE_PREFETCH),
509  [C(ITLB)]	= (CACHE_READ),
510  [C(BPU)]	= (CACHE_READ),
511  [C(NODE)]	= (CACHE_READ | CACHE_WRITE | CACHE_PREFETCH),
512 };
513 
514 bool perf_evsel__is_cache_op_valid(u8 type, u8 op)
515 {
516 	if (perf_evsel__hw_cache_stat[type] & COP(op))
517 		return true;	/* valid */
518 	else
519 		return false;	/* invalid */
520 }
521 
522 int __perf_evsel__hw_cache_type_op_res_name(u8 type, u8 op, u8 result,
523 					    char *bf, size_t size)
524 {
525 	if (result) {
526 		return scnprintf(bf, size, "%s-%s-%s", perf_evsel__hw_cache[type][0],
527 				 perf_evsel__hw_cache_op[op][0],
528 				 perf_evsel__hw_cache_result[result][0]);
529 	}
530 
531 	return scnprintf(bf, size, "%s-%s", perf_evsel__hw_cache[type][0],
532 			 perf_evsel__hw_cache_op[op][1]);
533 }
534 
535 static int __perf_evsel__hw_cache_name(u64 config, char *bf, size_t size)
536 {
537 	u8 op, result, type = (config >>  0) & 0xff;
538 	const char *err = "unknown-ext-hardware-cache-type";
539 
540 	if (type >= PERF_COUNT_HW_CACHE_MAX)
541 		goto out_err;
542 
543 	op = (config >>  8) & 0xff;
544 	err = "unknown-ext-hardware-cache-op";
545 	if (op >= PERF_COUNT_HW_CACHE_OP_MAX)
546 		goto out_err;
547 
548 	result = (config >> 16) & 0xff;
549 	err = "unknown-ext-hardware-cache-result";
550 	if (result >= PERF_COUNT_HW_CACHE_RESULT_MAX)
551 		goto out_err;
552 
553 	err = "invalid-cache";
554 	if (!perf_evsel__is_cache_op_valid(type, op))
555 		goto out_err;
556 
557 	return __perf_evsel__hw_cache_type_op_res_name(type, op, result, bf, size);
558 out_err:
559 	return scnprintf(bf, size, "%s", err);
560 }
561 
562 static int perf_evsel__hw_cache_name(struct perf_evsel *evsel, char *bf, size_t size)
563 {
564 	int ret = __perf_evsel__hw_cache_name(evsel->attr.config, bf, size);
565 	return ret + perf_evsel__add_modifiers(evsel, bf + ret, size - ret);
566 }
567 
568 static int perf_evsel__raw_name(struct perf_evsel *evsel, char *bf, size_t size)
569 {
570 	int ret = scnprintf(bf, size, "raw 0x%" PRIx64, evsel->attr.config);
571 	return ret + perf_evsel__add_modifiers(evsel, bf + ret, size - ret);
572 }
573 
574 const char *perf_evsel__name(struct perf_evsel *evsel)
575 {
576 	char bf[128];
577 
578 	if (evsel->name)
579 		return evsel->name;
580 
581 	switch (evsel->attr.type) {
582 	case PERF_TYPE_RAW:
583 		perf_evsel__raw_name(evsel, bf, sizeof(bf));
584 		break;
585 
586 	case PERF_TYPE_HARDWARE:
587 		perf_evsel__hw_name(evsel, bf, sizeof(bf));
588 		break;
589 
590 	case PERF_TYPE_HW_CACHE:
591 		perf_evsel__hw_cache_name(evsel, bf, sizeof(bf));
592 		break;
593 
594 	case PERF_TYPE_SOFTWARE:
595 		perf_evsel__sw_name(evsel, bf, sizeof(bf));
596 		break;
597 
598 	case PERF_TYPE_TRACEPOINT:
599 		scnprintf(bf, sizeof(bf), "%s", "unknown tracepoint");
600 		break;
601 
602 	case PERF_TYPE_BREAKPOINT:
603 		perf_evsel__bp_name(evsel, bf, sizeof(bf));
604 		break;
605 
606 	default:
607 		scnprintf(bf, sizeof(bf), "unknown attr type: %d",
608 			  evsel->attr.type);
609 		break;
610 	}
611 
612 	evsel->name = strdup(bf);
613 
614 	return evsel->name ?: "unknown";
615 }
616 
617 const char *perf_evsel__group_name(struct perf_evsel *evsel)
618 {
619 	return evsel->group_name ?: "anon group";
620 }
621 
622 int perf_evsel__group_desc(struct perf_evsel *evsel, char *buf, size_t size)
623 {
624 	int ret;
625 	struct perf_evsel *pos;
626 	const char *group_name = perf_evsel__group_name(evsel);
627 
628 	ret = scnprintf(buf, size, "%s", group_name);
629 
630 	ret += scnprintf(buf + ret, size - ret, " { %s",
631 			 perf_evsel__name(evsel));
632 
633 	for_each_group_member(pos, evsel)
634 		ret += scnprintf(buf + ret, size - ret, ", %s",
635 				 perf_evsel__name(pos));
636 
637 	ret += scnprintf(buf + ret, size - ret, " }");
638 
639 	return ret;
640 }
641 
642 void perf_evsel__config_callchain(struct perf_evsel *evsel,
643 				  struct record_opts *opts,
644 				  struct callchain_param *param)
645 {
646 	bool function = perf_evsel__is_function_event(evsel);
647 	struct perf_event_attr *attr = &evsel->attr;
648 
649 	perf_evsel__set_sample_bit(evsel, CALLCHAIN);
650 
651 	attr->sample_max_stack = param->max_stack;
652 
653 	if (param->record_mode == CALLCHAIN_LBR) {
654 		if (!opts->branch_stack) {
655 			if (attr->exclude_user) {
656 				pr_warning("LBR callstack option is only available "
657 					   "to get user callchain information. "
658 					   "Falling back to framepointers.\n");
659 			} else {
660 				perf_evsel__set_sample_bit(evsel, BRANCH_STACK);
661 				attr->branch_sample_type = PERF_SAMPLE_BRANCH_USER |
662 							PERF_SAMPLE_BRANCH_CALL_STACK |
663 							PERF_SAMPLE_BRANCH_NO_CYCLES |
664 							PERF_SAMPLE_BRANCH_NO_FLAGS;
665 			}
666 		} else
667 			 pr_warning("Cannot use LBR callstack with branch stack. "
668 				    "Falling back to framepointers.\n");
669 	}
670 
671 	if (param->record_mode == CALLCHAIN_DWARF) {
672 		if (!function) {
673 			perf_evsel__set_sample_bit(evsel, REGS_USER);
674 			perf_evsel__set_sample_bit(evsel, STACK_USER);
675 			attr->sample_regs_user = PERF_REGS_MASK;
676 			attr->sample_stack_user = param->dump_size;
677 			attr->exclude_callchain_user = 1;
678 		} else {
679 			pr_info("Cannot use DWARF unwind for function trace event,"
680 				" falling back to framepointers.\n");
681 		}
682 	}
683 
684 	if (function) {
685 		pr_info("Disabling user space callchains for function trace event.\n");
686 		attr->exclude_callchain_user = 1;
687 	}
688 }
689 
690 static void
691 perf_evsel__reset_callgraph(struct perf_evsel *evsel,
692 			    struct callchain_param *param)
693 {
694 	struct perf_event_attr *attr = &evsel->attr;
695 
696 	perf_evsel__reset_sample_bit(evsel, CALLCHAIN);
697 	if (param->record_mode == CALLCHAIN_LBR) {
698 		perf_evsel__reset_sample_bit(evsel, BRANCH_STACK);
699 		attr->branch_sample_type &= ~(PERF_SAMPLE_BRANCH_USER |
700 					      PERF_SAMPLE_BRANCH_CALL_STACK);
701 	}
702 	if (param->record_mode == CALLCHAIN_DWARF) {
703 		perf_evsel__reset_sample_bit(evsel, REGS_USER);
704 		perf_evsel__reset_sample_bit(evsel, STACK_USER);
705 	}
706 }
707 
708 static void apply_config_terms(struct perf_evsel *evsel,
709 			       struct record_opts *opts)
710 {
711 	struct perf_evsel_config_term *term;
712 	struct list_head *config_terms = &evsel->config_terms;
713 	struct perf_event_attr *attr = &evsel->attr;
714 	struct callchain_param param;
715 	u32 dump_size = 0;
716 	int max_stack = 0;
717 	const char *callgraph_buf = NULL;
718 
719 	/* callgraph default */
720 	param.record_mode = callchain_param.record_mode;
721 
722 	list_for_each_entry(term, config_terms, list) {
723 		switch (term->type) {
724 		case PERF_EVSEL__CONFIG_TERM_PERIOD:
725 			attr->sample_period = term->val.period;
726 			attr->freq = 0;
727 			break;
728 		case PERF_EVSEL__CONFIG_TERM_FREQ:
729 			attr->sample_freq = term->val.freq;
730 			attr->freq = 1;
731 			break;
732 		case PERF_EVSEL__CONFIG_TERM_TIME:
733 			if (term->val.time)
734 				perf_evsel__set_sample_bit(evsel, TIME);
735 			else
736 				perf_evsel__reset_sample_bit(evsel, TIME);
737 			break;
738 		case PERF_EVSEL__CONFIG_TERM_CALLGRAPH:
739 			callgraph_buf = term->val.callgraph;
740 			break;
741 		case PERF_EVSEL__CONFIG_TERM_BRANCH:
742 			if (term->val.branch && strcmp(term->val.branch, "no")) {
743 				perf_evsel__set_sample_bit(evsel, BRANCH_STACK);
744 				parse_branch_str(term->val.branch,
745 						 &attr->branch_sample_type);
746 			} else
747 				perf_evsel__reset_sample_bit(evsel, BRANCH_STACK);
748 			break;
749 		case PERF_EVSEL__CONFIG_TERM_STACK_USER:
750 			dump_size = term->val.stack_user;
751 			break;
752 		case PERF_EVSEL__CONFIG_TERM_MAX_STACK:
753 			max_stack = term->val.max_stack;
754 			break;
755 		case PERF_EVSEL__CONFIG_TERM_INHERIT:
756 			/*
757 			 * attr->inherit should has already been set by
758 			 * perf_evsel__config. If user explicitly set
759 			 * inherit using config terms, override global
760 			 * opt->no_inherit setting.
761 			 */
762 			attr->inherit = term->val.inherit ? 1 : 0;
763 			break;
764 		case PERF_EVSEL__CONFIG_TERM_OVERWRITE:
765 			attr->write_backward = term->val.overwrite ? 1 : 0;
766 			break;
767 		default:
768 			break;
769 		}
770 	}
771 
772 	/* User explicitly set per-event callgraph, clear the old setting and reset. */
773 	if ((callgraph_buf != NULL) || (dump_size > 0) || max_stack) {
774 		if (max_stack) {
775 			param.max_stack = max_stack;
776 			if (callgraph_buf == NULL)
777 				callgraph_buf = "fp";
778 		}
779 
780 		/* parse callgraph parameters */
781 		if (callgraph_buf != NULL) {
782 			if (!strcmp(callgraph_buf, "no")) {
783 				param.enabled = false;
784 				param.record_mode = CALLCHAIN_NONE;
785 			} else {
786 				param.enabled = true;
787 				if (parse_callchain_record(callgraph_buf, &param)) {
788 					pr_err("per-event callgraph setting for %s failed. "
789 					       "Apply callgraph global setting for it\n",
790 					       evsel->name);
791 					return;
792 				}
793 			}
794 		}
795 		if (dump_size > 0) {
796 			dump_size = round_up(dump_size, sizeof(u64));
797 			param.dump_size = dump_size;
798 		}
799 
800 		/* If global callgraph set, clear it */
801 		if (callchain_param.enabled)
802 			perf_evsel__reset_callgraph(evsel, &callchain_param);
803 
804 		/* set perf-event callgraph */
805 		if (param.enabled)
806 			perf_evsel__config_callchain(evsel, opts, &param);
807 	}
808 }
809 
810 /*
811  * The enable_on_exec/disabled value strategy:
812  *
813  *  1) For any type of traced program:
814  *    - all independent events and group leaders are disabled
815  *    - all group members are enabled
816  *
817  *     Group members are ruled by group leaders. They need to
818  *     be enabled, because the group scheduling relies on that.
819  *
820  *  2) For traced programs executed by perf:
821  *     - all independent events and group leaders have
822  *       enable_on_exec set
823  *     - we don't specifically enable or disable any event during
824  *       the record command
825  *
826  *     Independent events and group leaders are initially disabled
827  *     and get enabled by exec. Group members are ruled by group
828  *     leaders as stated in 1).
829  *
830  *  3) For traced programs attached by perf (pid/tid):
831  *     - we specifically enable or disable all events during
832  *       the record command
833  *
834  *     When attaching events to already running traced we
835  *     enable/disable events specifically, as there's no
836  *     initial traced exec call.
837  */
838 void perf_evsel__config(struct perf_evsel *evsel, struct record_opts *opts,
839 			struct callchain_param *callchain)
840 {
841 	struct perf_evsel *leader = evsel->leader;
842 	struct perf_event_attr *attr = &evsel->attr;
843 	int track = evsel->tracking;
844 	bool per_cpu = opts->target.default_per_cpu && !opts->target.per_thread;
845 
846 	attr->sample_id_all = perf_missing_features.sample_id_all ? 0 : 1;
847 	attr->inherit	    = !opts->no_inherit;
848 	attr->write_backward = opts->overwrite ? 1 : 0;
849 
850 	perf_evsel__set_sample_bit(evsel, IP);
851 	perf_evsel__set_sample_bit(evsel, TID);
852 
853 	if (evsel->sample_read) {
854 		perf_evsel__set_sample_bit(evsel, READ);
855 
856 		/*
857 		 * We need ID even in case of single event, because
858 		 * PERF_SAMPLE_READ process ID specific data.
859 		 */
860 		perf_evsel__set_sample_id(evsel, false);
861 
862 		/*
863 		 * Apply group format only if we belong to group
864 		 * with more than one members.
865 		 */
866 		if (leader->nr_members > 1) {
867 			attr->read_format |= PERF_FORMAT_GROUP;
868 			attr->inherit = 0;
869 		}
870 	}
871 
872 	/*
873 	 * We default some events to have a default interval. But keep
874 	 * it a weak assumption overridable by the user.
875 	 */
876 	if (!attr->sample_period || (opts->user_freq != UINT_MAX ||
877 				     opts->user_interval != ULLONG_MAX)) {
878 		if (opts->freq) {
879 			perf_evsel__set_sample_bit(evsel, PERIOD);
880 			attr->freq		= 1;
881 			attr->sample_freq	= opts->freq;
882 		} else {
883 			attr->sample_period = opts->default_interval;
884 		}
885 	}
886 
887 	/*
888 	 * Disable sampling for all group members other
889 	 * than leader in case leader 'leads' the sampling.
890 	 */
891 	if ((leader != evsel) && leader->sample_read) {
892 		attr->sample_freq   = 0;
893 		attr->sample_period = 0;
894 	}
895 
896 	if (opts->no_samples)
897 		attr->sample_freq = 0;
898 
899 	if (opts->inherit_stat)
900 		attr->inherit_stat = 1;
901 
902 	if (opts->sample_address) {
903 		perf_evsel__set_sample_bit(evsel, ADDR);
904 		attr->mmap_data = track;
905 	}
906 
907 	/*
908 	 * We don't allow user space callchains for  function trace
909 	 * event, due to issues with page faults while tracing page
910 	 * fault handler and its overall trickiness nature.
911 	 */
912 	if (perf_evsel__is_function_event(evsel))
913 		evsel->attr.exclude_callchain_user = 1;
914 
915 	if (callchain && callchain->enabled && !evsel->no_aux_samples)
916 		perf_evsel__config_callchain(evsel, opts, callchain);
917 
918 	if (opts->sample_intr_regs) {
919 		attr->sample_regs_intr = opts->sample_intr_regs;
920 		perf_evsel__set_sample_bit(evsel, REGS_INTR);
921 	}
922 
923 	if (target__has_cpu(&opts->target) || opts->sample_cpu)
924 		perf_evsel__set_sample_bit(evsel, CPU);
925 
926 	if (opts->period)
927 		perf_evsel__set_sample_bit(evsel, PERIOD);
928 
929 	/*
930 	 * When the user explicitly disabled time don't force it here.
931 	 */
932 	if (opts->sample_time &&
933 	    (!perf_missing_features.sample_id_all &&
934 	    (!opts->no_inherit || target__has_cpu(&opts->target) || per_cpu ||
935 	     opts->sample_time_set)))
936 		perf_evsel__set_sample_bit(evsel, TIME);
937 
938 	if (opts->raw_samples && !evsel->no_aux_samples) {
939 		perf_evsel__set_sample_bit(evsel, TIME);
940 		perf_evsel__set_sample_bit(evsel, RAW);
941 		perf_evsel__set_sample_bit(evsel, CPU);
942 	}
943 
944 	if (opts->sample_address)
945 		perf_evsel__set_sample_bit(evsel, DATA_SRC);
946 
947 	if (opts->no_buffering) {
948 		attr->watermark = 0;
949 		attr->wakeup_events = 1;
950 	}
951 	if (opts->branch_stack && !evsel->no_aux_samples) {
952 		perf_evsel__set_sample_bit(evsel, BRANCH_STACK);
953 		attr->branch_sample_type = opts->branch_stack;
954 	}
955 
956 	if (opts->sample_weight)
957 		perf_evsel__set_sample_bit(evsel, WEIGHT);
958 
959 	attr->task  = track;
960 	attr->mmap  = track;
961 	attr->mmap2 = track && !perf_missing_features.mmap2;
962 	attr->comm  = track;
963 
964 	if (opts->record_namespaces)
965 		attr->namespaces  = track;
966 
967 	if (opts->record_switch_events)
968 		attr->context_switch = track;
969 
970 	if (opts->sample_transaction)
971 		perf_evsel__set_sample_bit(evsel, TRANSACTION);
972 
973 	if (opts->running_time) {
974 		evsel->attr.read_format |=
975 			PERF_FORMAT_TOTAL_TIME_ENABLED |
976 			PERF_FORMAT_TOTAL_TIME_RUNNING;
977 	}
978 
979 	/*
980 	 * XXX see the function comment above
981 	 *
982 	 * Disabling only independent events or group leaders,
983 	 * keeping group members enabled.
984 	 */
985 	if (perf_evsel__is_group_leader(evsel))
986 		attr->disabled = 1;
987 
988 	/*
989 	 * Setting enable_on_exec for independent events and
990 	 * group leaders for traced executed by perf.
991 	 */
992 	if (target__none(&opts->target) && perf_evsel__is_group_leader(evsel) &&
993 		!opts->initial_delay)
994 		attr->enable_on_exec = 1;
995 
996 	if (evsel->immediate) {
997 		attr->disabled = 0;
998 		attr->enable_on_exec = 0;
999 	}
1000 
1001 	clockid = opts->clockid;
1002 	if (opts->use_clockid) {
1003 		attr->use_clockid = 1;
1004 		attr->clockid = opts->clockid;
1005 	}
1006 
1007 	if (evsel->precise_max)
1008 		perf_event_attr__set_max_precise_ip(attr);
1009 
1010 	if (opts->all_user) {
1011 		attr->exclude_kernel = 1;
1012 		attr->exclude_user   = 0;
1013 	}
1014 
1015 	if (opts->all_kernel) {
1016 		attr->exclude_kernel = 0;
1017 		attr->exclude_user   = 1;
1018 	}
1019 
1020 	/*
1021 	 * Apply event specific term settings,
1022 	 * it overloads any global configuration.
1023 	 */
1024 	apply_config_terms(evsel, opts);
1025 
1026 	evsel->ignore_missing_thread = opts->ignore_missing_thread;
1027 }
1028 
1029 static int perf_evsel__alloc_fd(struct perf_evsel *evsel, int ncpus, int nthreads)
1030 {
1031 	if (evsel->system_wide)
1032 		nthreads = 1;
1033 
1034 	evsel->fd = xyarray__new(ncpus, nthreads, sizeof(int));
1035 
1036 	if (evsel->fd) {
1037 		int cpu, thread;
1038 		for (cpu = 0; cpu < ncpus; cpu++) {
1039 			for (thread = 0; thread < nthreads; thread++) {
1040 				FD(evsel, cpu, thread) = -1;
1041 			}
1042 		}
1043 	}
1044 
1045 	return evsel->fd != NULL ? 0 : -ENOMEM;
1046 }
1047 
1048 static int perf_evsel__run_ioctl(struct perf_evsel *evsel, int ncpus, int nthreads,
1049 			  int ioc,  void *arg)
1050 {
1051 	int cpu, thread;
1052 
1053 	if (evsel->system_wide)
1054 		nthreads = 1;
1055 
1056 	for (cpu = 0; cpu < ncpus; cpu++) {
1057 		for (thread = 0; thread < nthreads; thread++) {
1058 			int fd = FD(evsel, cpu, thread),
1059 			    err = ioctl(fd, ioc, arg);
1060 
1061 			if (err)
1062 				return err;
1063 		}
1064 	}
1065 
1066 	return 0;
1067 }
1068 
1069 int perf_evsel__apply_filter(struct perf_evsel *evsel, int ncpus, int nthreads,
1070 			     const char *filter)
1071 {
1072 	return perf_evsel__run_ioctl(evsel, ncpus, nthreads,
1073 				     PERF_EVENT_IOC_SET_FILTER,
1074 				     (void *)filter);
1075 }
1076 
1077 int perf_evsel__set_filter(struct perf_evsel *evsel, const char *filter)
1078 {
1079 	char *new_filter = strdup(filter);
1080 
1081 	if (new_filter != NULL) {
1082 		free(evsel->filter);
1083 		evsel->filter = new_filter;
1084 		return 0;
1085 	}
1086 
1087 	return -1;
1088 }
1089 
1090 static int perf_evsel__append_filter(struct perf_evsel *evsel,
1091 				     const char *fmt, const char *filter)
1092 {
1093 	char *new_filter;
1094 
1095 	if (evsel->filter == NULL)
1096 		return perf_evsel__set_filter(evsel, filter);
1097 
1098 	if (asprintf(&new_filter, fmt, evsel->filter, filter) > 0) {
1099 		free(evsel->filter);
1100 		evsel->filter = new_filter;
1101 		return 0;
1102 	}
1103 
1104 	return -1;
1105 }
1106 
1107 int perf_evsel__append_tp_filter(struct perf_evsel *evsel, const char *filter)
1108 {
1109 	return perf_evsel__append_filter(evsel, "(%s) && (%s)", filter);
1110 }
1111 
1112 int perf_evsel__append_addr_filter(struct perf_evsel *evsel, const char *filter)
1113 {
1114 	return perf_evsel__append_filter(evsel, "%s,%s", filter);
1115 }
1116 
1117 int perf_evsel__enable(struct perf_evsel *evsel)
1118 {
1119 	int nthreads = thread_map__nr(evsel->threads);
1120 	int ncpus = cpu_map__nr(evsel->cpus);
1121 
1122 	return perf_evsel__run_ioctl(evsel, ncpus, nthreads,
1123 				     PERF_EVENT_IOC_ENABLE,
1124 				     0);
1125 }
1126 
1127 int perf_evsel__disable(struct perf_evsel *evsel)
1128 {
1129 	int nthreads = thread_map__nr(evsel->threads);
1130 	int ncpus = cpu_map__nr(evsel->cpus);
1131 
1132 	return perf_evsel__run_ioctl(evsel, ncpus, nthreads,
1133 				     PERF_EVENT_IOC_DISABLE,
1134 				     0);
1135 }
1136 
1137 int perf_evsel__alloc_id(struct perf_evsel *evsel, int ncpus, int nthreads)
1138 {
1139 	if (ncpus == 0 || nthreads == 0)
1140 		return 0;
1141 
1142 	if (evsel->system_wide)
1143 		nthreads = 1;
1144 
1145 	evsel->sample_id = xyarray__new(ncpus, nthreads, sizeof(struct perf_sample_id));
1146 	if (evsel->sample_id == NULL)
1147 		return -ENOMEM;
1148 
1149 	evsel->id = zalloc(ncpus * nthreads * sizeof(u64));
1150 	if (evsel->id == NULL) {
1151 		xyarray__delete(evsel->sample_id);
1152 		evsel->sample_id = NULL;
1153 		return -ENOMEM;
1154 	}
1155 
1156 	return 0;
1157 }
1158 
1159 static void perf_evsel__free_fd(struct perf_evsel *evsel)
1160 {
1161 	xyarray__delete(evsel->fd);
1162 	evsel->fd = NULL;
1163 }
1164 
1165 static void perf_evsel__free_id(struct perf_evsel *evsel)
1166 {
1167 	xyarray__delete(evsel->sample_id);
1168 	evsel->sample_id = NULL;
1169 	zfree(&evsel->id);
1170 }
1171 
1172 static void perf_evsel__free_config_terms(struct perf_evsel *evsel)
1173 {
1174 	struct perf_evsel_config_term *term, *h;
1175 
1176 	list_for_each_entry_safe(term, h, &evsel->config_terms, list) {
1177 		list_del(&term->list);
1178 		free(term);
1179 	}
1180 }
1181 
1182 void perf_evsel__close_fd(struct perf_evsel *evsel, int ncpus, int nthreads)
1183 {
1184 	int cpu, thread;
1185 
1186 	if (evsel->system_wide)
1187 		nthreads = 1;
1188 
1189 	for (cpu = 0; cpu < ncpus; cpu++)
1190 		for (thread = 0; thread < nthreads; ++thread) {
1191 			close(FD(evsel, cpu, thread));
1192 			FD(evsel, cpu, thread) = -1;
1193 		}
1194 }
1195 
1196 void perf_evsel__exit(struct perf_evsel *evsel)
1197 {
1198 	assert(list_empty(&evsel->node));
1199 	assert(evsel->evlist == NULL);
1200 	perf_evsel__free_fd(evsel);
1201 	perf_evsel__free_id(evsel);
1202 	perf_evsel__free_config_terms(evsel);
1203 	close_cgroup(evsel->cgrp);
1204 	cpu_map__put(evsel->cpus);
1205 	cpu_map__put(evsel->own_cpus);
1206 	thread_map__put(evsel->threads);
1207 	zfree(&evsel->group_name);
1208 	zfree(&evsel->name);
1209 	perf_evsel__object.fini(evsel);
1210 }
1211 
1212 void perf_evsel__delete(struct perf_evsel *evsel)
1213 {
1214 	perf_evsel__exit(evsel);
1215 	free(evsel);
1216 }
1217 
1218 void perf_evsel__compute_deltas(struct perf_evsel *evsel, int cpu, int thread,
1219 				struct perf_counts_values *count)
1220 {
1221 	struct perf_counts_values tmp;
1222 
1223 	if (!evsel->prev_raw_counts)
1224 		return;
1225 
1226 	if (cpu == -1) {
1227 		tmp = evsel->prev_raw_counts->aggr;
1228 		evsel->prev_raw_counts->aggr = *count;
1229 	} else {
1230 		tmp = *perf_counts(evsel->prev_raw_counts, cpu, thread);
1231 		*perf_counts(evsel->prev_raw_counts, cpu, thread) = *count;
1232 	}
1233 
1234 	count->val = count->val - tmp.val;
1235 	count->ena = count->ena - tmp.ena;
1236 	count->run = count->run - tmp.run;
1237 }
1238 
1239 void perf_counts_values__scale(struct perf_counts_values *count,
1240 			       bool scale, s8 *pscaled)
1241 {
1242 	s8 scaled = 0;
1243 
1244 	if (scale) {
1245 		if (count->run == 0) {
1246 			scaled = -1;
1247 			count->val = 0;
1248 		} else if (count->run < count->ena) {
1249 			scaled = 1;
1250 			count->val = (u64)((double) count->val * count->ena / count->run + 0.5);
1251 		}
1252 	} else
1253 		count->ena = count->run = 0;
1254 
1255 	if (pscaled)
1256 		*pscaled = scaled;
1257 }
1258 
1259 int perf_evsel__read(struct perf_evsel *evsel, int cpu, int thread,
1260 		     struct perf_counts_values *count)
1261 {
1262 	memset(count, 0, sizeof(*count));
1263 
1264 	if (FD(evsel, cpu, thread) < 0)
1265 		return -EINVAL;
1266 
1267 	if (readn(FD(evsel, cpu, thread), count, sizeof(*count)) <= 0)
1268 		return -errno;
1269 
1270 	return 0;
1271 }
1272 
1273 int __perf_evsel__read_on_cpu(struct perf_evsel *evsel,
1274 			      int cpu, int thread, bool scale)
1275 {
1276 	struct perf_counts_values count;
1277 	size_t nv = scale ? 3 : 1;
1278 
1279 	if (FD(evsel, cpu, thread) < 0)
1280 		return -EINVAL;
1281 
1282 	if (evsel->counts == NULL && perf_evsel__alloc_counts(evsel, cpu + 1, thread + 1) < 0)
1283 		return -ENOMEM;
1284 
1285 	if (readn(FD(evsel, cpu, thread), &count, nv * sizeof(u64)) <= 0)
1286 		return -errno;
1287 
1288 	perf_evsel__compute_deltas(evsel, cpu, thread, &count);
1289 	perf_counts_values__scale(&count, scale, NULL);
1290 	*perf_counts(evsel->counts, cpu, thread) = count;
1291 	return 0;
1292 }
1293 
1294 static int get_group_fd(struct perf_evsel *evsel, int cpu, int thread)
1295 {
1296 	struct perf_evsel *leader = evsel->leader;
1297 	int fd;
1298 
1299 	if (perf_evsel__is_group_leader(evsel))
1300 		return -1;
1301 
1302 	/*
1303 	 * Leader must be already processed/open,
1304 	 * if not it's a bug.
1305 	 */
1306 	BUG_ON(!leader->fd);
1307 
1308 	fd = FD(leader, cpu, thread);
1309 	BUG_ON(fd == -1);
1310 
1311 	return fd;
1312 }
1313 
1314 struct bit_names {
1315 	int bit;
1316 	const char *name;
1317 };
1318 
1319 static void __p_bits(char *buf, size_t size, u64 value, struct bit_names *bits)
1320 {
1321 	bool first_bit = true;
1322 	int i = 0;
1323 
1324 	do {
1325 		if (value & bits[i].bit) {
1326 			buf += scnprintf(buf, size, "%s%s", first_bit ? "" : "|", bits[i].name);
1327 			first_bit = false;
1328 		}
1329 	} while (bits[++i].name != NULL);
1330 }
1331 
1332 static void __p_sample_type(char *buf, size_t size, u64 value)
1333 {
1334 #define bit_name(n) { PERF_SAMPLE_##n, #n }
1335 	struct bit_names bits[] = {
1336 		bit_name(IP), bit_name(TID), bit_name(TIME), bit_name(ADDR),
1337 		bit_name(READ), bit_name(CALLCHAIN), bit_name(ID), bit_name(CPU),
1338 		bit_name(PERIOD), bit_name(STREAM_ID), bit_name(RAW),
1339 		bit_name(BRANCH_STACK), bit_name(REGS_USER), bit_name(STACK_USER),
1340 		bit_name(IDENTIFIER), bit_name(REGS_INTR), bit_name(DATA_SRC),
1341 		bit_name(WEIGHT),
1342 		{ .name = NULL, }
1343 	};
1344 #undef bit_name
1345 	__p_bits(buf, size, value, bits);
1346 }
1347 
1348 static void __p_branch_sample_type(char *buf, size_t size, u64 value)
1349 {
1350 #define bit_name(n) { PERF_SAMPLE_BRANCH_##n, #n }
1351 	struct bit_names bits[] = {
1352 		bit_name(USER), bit_name(KERNEL), bit_name(HV), bit_name(ANY),
1353 		bit_name(ANY_CALL), bit_name(ANY_RETURN), bit_name(IND_CALL),
1354 		bit_name(ABORT_TX), bit_name(IN_TX), bit_name(NO_TX),
1355 		bit_name(COND), bit_name(CALL_STACK), bit_name(IND_JUMP),
1356 		bit_name(CALL), bit_name(NO_FLAGS), bit_name(NO_CYCLES),
1357 		{ .name = NULL, }
1358 	};
1359 #undef bit_name
1360 	__p_bits(buf, size, value, bits);
1361 }
1362 
1363 static void __p_read_format(char *buf, size_t size, u64 value)
1364 {
1365 #define bit_name(n) { PERF_FORMAT_##n, #n }
1366 	struct bit_names bits[] = {
1367 		bit_name(TOTAL_TIME_ENABLED), bit_name(TOTAL_TIME_RUNNING),
1368 		bit_name(ID), bit_name(GROUP),
1369 		{ .name = NULL, }
1370 	};
1371 #undef bit_name
1372 	__p_bits(buf, size, value, bits);
1373 }
1374 
1375 #define BUF_SIZE		1024
1376 
1377 #define p_hex(val)		snprintf(buf, BUF_SIZE, "%#"PRIx64, (uint64_t)(val))
1378 #define p_unsigned(val)		snprintf(buf, BUF_SIZE, "%"PRIu64, (uint64_t)(val))
1379 #define p_signed(val)		snprintf(buf, BUF_SIZE, "%"PRId64, (int64_t)(val))
1380 #define p_sample_type(val)	__p_sample_type(buf, BUF_SIZE, val)
1381 #define p_branch_sample_type(val) __p_branch_sample_type(buf, BUF_SIZE, val)
1382 #define p_read_format(val)	__p_read_format(buf, BUF_SIZE, val)
1383 
1384 #define PRINT_ATTRn(_n, _f, _p)				\
1385 do {							\
1386 	if (attr->_f) {					\
1387 		_p(attr->_f);				\
1388 		ret += attr__fprintf(fp, _n, buf, priv);\
1389 	}						\
1390 } while (0)
1391 
1392 #define PRINT_ATTRf(_f, _p)	PRINT_ATTRn(#_f, _f, _p)
1393 
1394 int perf_event_attr__fprintf(FILE *fp, struct perf_event_attr *attr,
1395 			     attr__fprintf_f attr__fprintf, void *priv)
1396 {
1397 	char buf[BUF_SIZE];
1398 	int ret = 0;
1399 
1400 	PRINT_ATTRf(type, p_unsigned);
1401 	PRINT_ATTRf(size, p_unsigned);
1402 	PRINT_ATTRf(config, p_hex);
1403 	PRINT_ATTRn("{ sample_period, sample_freq }", sample_period, p_unsigned);
1404 	PRINT_ATTRf(sample_type, p_sample_type);
1405 	PRINT_ATTRf(read_format, p_read_format);
1406 
1407 	PRINT_ATTRf(disabled, p_unsigned);
1408 	PRINT_ATTRf(inherit, p_unsigned);
1409 	PRINT_ATTRf(pinned, p_unsigned);
1410 	PRINT_ATTRf(exclusive, p_unsigned);
1411 	PRINT_ATTRf(exclude_user, p_unsigned);
1412 	PRINT_ATTRf(exclude_kernel, p_unsigned);
1413 	PRINT_ATTRf(exclude_hv, p_unsigned);
1414 	PRINT_ATTRf(exclude_idle, p_unsigned);
1415 	PRINT_ATTRf(mmap, p_unsigned);
1416 	PRINT_ATTRf(comm, p_unsigned);
1417 	PRINT_ATTRf(freq, p_unsigned);
1418 	PRINT_ATTRf(inherit_stat, p_unsigned);
1419 	PRINT_ATTRf(enable_on_exec, p_unsigned);
1420 	PRINT_ATTRf(task, p_unsigned);
1421 	PRINT_ATTRf(watermark, p_unsigned);
1422 	PRINT_ATTRf(precise_ip, p_unsigned);
1423 	PRINT_ATTRf(mmap_data, p_unsigned);
1424 	PRINT_ATTRf(sample_id_all, p_unsigned);
1425 	PRINT_ATTRf(exclude_host, p_unsigned);
1426 	PRINT_ATTRf(exclude_guest, p_unsigned);
1427 	PRINT_ATTRf(exclude_callchain_kernel, p_unsigned);
1428 	PRINT_ATTRf(exclude_callchain_user, p_unsigned);
1429 	PRINT_ATTRf(mmap2, p_unsigned);
1430 	PRINT_ATTRf(comm_exec, p_unsigned);
1431 	PRINT_ATTRf(use_clockid, p_unsigned);
1432 	PRINT_ATTRf(context_switch, p_unsigned);
1433 	PRINT_ATTRf(write_backward, p_unsigned);
1434 
1435 	PRINT_ATTRn("{ wakeup_events, wakeup_watermark }", wakeup_events, p_unsigned);
1436 	PRINT_ATTRf(bp_type, p_unsigned);
1437 	PRINT_ATTRn("{ bp_addr, config1 }", bp_addr, p_hex);
1438 	PRINT_ATTRn("{ bp_len, config2 }", bp_len, p_hex);
1439 	PRINT_ATTRf(branch_sample_type, p_branch_sample_type);
1440 	PRINT_ATTRf(sample_regs_user, p_hex);
1441 	PRINT_ATTRf(sample_stack_user, p_unsigned);
1442 	PRINT_ATTRf(clockid, p_signed);
1443 	PRINT_ATTRf(sample_regs_intr, p_hex);
1444 	PRINT_ATTRf(aux_watermark, p_unsigned);
1445 	PRINT_ATTRf(sample_max_stack, p_unsigned);
1446 
1447 	return ret;
1448 }
1449 
1450 static int __open_attr__fprintf(FILE *fp, const char *name, const char *val,
1451 				void *priv __maybe_unused)
1452 {
1453 	return fprintf(fp, "  %-32s %s\n", name, val);
1454 }
1455 
1456 static bool ignore_missing_thread(struct perf_evsel *evsel,
1457 				  struct thread_map *threads,
1458 				  int thread, int err)
1459 {
1460 	if (!evsel->ignore_missing_thread)
1461 		return false;
1462 
1463 	/* The system wide setup does not work with threads. */
1464 	if (evsel->system_wide)
1465 		return false;
1466 
1467 	/* The -ESRCH is perf event syscall errno for pid's not found. */
1468 	if (err != -ESRCH)
1469 		return false;
1470 
1471 	/* If there's only one thread, let it fail. */
1472 	if (threads->nr == 1)
1473 		return false;
1474 
1475 	if (thread_map__remove(threads, thread))
1476 		return false;
1477 
1478 	pr_warning("WARNING: Ignored open failure for pid %d\n",
1479 		   thread_map__pid(threads, thread));
1480 	return true;
1481 }
1482 
1483 int perf_evsel__open(struct perf_evsel *evsel, struct cpu_map *cpus,
1484 		     struct thread_map *threads)
1485 {
1486 	int cpu, thread, nthreads;
1487 	unsigned long flags = PERF_FLAG_FD_CLOEXEC;
1488 	int pid = -1, err;
1489 	enum { NO_CHANGE, SET_TO_MAX, INCREASED_MAX } set_rlimit = NO_CHANGE;
1490 
1491 	if (perf_missing_features.write_backward && evsel->attr.write_backward)
1492 		return -EINVAL;
1493 
1494 	if (cpus == NULL) {
1495 		static struct cpu_map *empty_cpu_map;
1496 
1497 		if (empty_cpu_map == NULL) {
1498 			empty_cpu_map = cpu_map__dummy_new();
1499 			if (empty_cpu_map == NULL)
1500 				return -ENOMEM;
1501 		}
1502 
1503 		cpus = empty_cpu_map;
1504 	}
1505 
1506 	if (threads == NULL) {
1507 		static struct thread_map *empty_thread_map;
1508 
1509 		if (empty_thread_map == NULL) {
1510 			empty_thread_map = thread_map__new_by_tid(-1);
1511 			if (empty_thread_map == NULL)
1512 				return -ENOMEM;
1513 		}
1514 
1515 		threads = empty_thread_map;
1516 	}
1517 
1518 	if (evsel->system_wide)
1519 		nthreads = 1;
1520 	else
1521 		nthreads = threads->nr;
1522 
1523 	if (evsel->fd == NULL &&
1524 	    perf_evsel__alloc_fd(evsel, cpus->nr, nthreads) < 0)
1525 		return -ENOMEM;
1526 
1527 	if (evsel->cgrp) {
1528 		flags |= PERF_FLAG_PID_CGROUP;
1529 		pid = evsel->cgrp->fd;
1530 	}
1531 
1532 fallback_missing_features:
1533 	if (perf_missing_features.clockid_wrong)
1534 		evsel->attr.clockid = CLOCK_MONOTONIC; /* should always work */
1535 	if (perf_missing_features.clockid) {
1536 		evsel->attr.use_clockid = 0;
1537 		evsel->attr.clockid = 0;
1538 	}
1539 	if (perf_missing_features.cloexec)
1540 		flags &= ~(unsigned long)PERF_FLAG_FD_CLOEXEC;
1541 	if (perf_missing_features.mmap2)
1542 		evsel->attr.mmap2 = 0;
1543 	if (perf_missing_features.exclude_guest)
1544 		evsel->attr.exclude_guest = evsel->attr.exclude_host = 0;
1545 	if (perf_missing_features.lbr_flags)
1546 		evsel->attr.branch_sample_type &= ~(PERF_SAMPLE_BRANCH_NO_FLAGS |
1547 				     PERF_SAMPLE_BRANCH_NO_CYCLES);
1548 retry_sample_id:
1549 	if (perf_missing_features.sample_id_all)
1550 		evsel->attr.sample_id_all = 0;
1551 
1552 	if (verbose >= 2) {
1553 		fprintf(stderr, "%.60s\n", graph_dotted_line);
1554 		fprintf(stderr, "perf_event_attr:\n");
1555 		perf_event_attr__fprintf(stderr, &evsel->attr, __open_attr__fprintf, NULL);
1556 		fprintf(stderr, "%.60s\n", graph_dotted_line);
1557 	}
1558 
1559 	for (cpu = 0; cpu < cpus->nr; cpu++) {
1560 
1561 		for (thread = 0; thread < nthreads; thread++) {
1562 			int fd, group_fd;
1563 
1564 			if (!evsel->cgrp && !evsel->system_wide)
1565 				pid = thread_map__pid(threads, thread);
1566 
1567 			group_fd = get_group_fd(evsel, cpu, thread);
1568 retry_open:
1569 			pr_debug2("sys_perf_event_open: pid %d  cpu %d  group_fd %d  flags %#lx",
1570 				  pid, cpus->map[cpu], group_fd, flags);
1571 
1572 			fd = sys_perf_event_open(&evsel->attr, pid, cpus->map[cpu],
1573 						 group_fd, flags);
1574 
1575 			FD(evsel, cpu, thread) = fd;
1576 
1577 			if (fd < 0) {
1578 				err = -errno;
1579 
1580 				if (ignore_missing_thread(evsel, threads, thread, err)) {
1581 					/*
1582 					 * We just removed 1 thread, so take a step
1583 					 * back on thread index and lower the upper
1584 					 * nthreads limit.
1585 					 */
1586 					nthreads--;
1587 					thread--;
1588 
1589 					/* ... and pretend like nothing have happened. */
1590 					err = 0;
1591 					continue;
1592 				}
1593 
1594 				pr_debug2("\nsys_perf_event_open failed, error %d\n",
1595 					  err);
1596 				goto try_fallback;
1597 			}
1598 
1599 			pr_debug2(" = %d\n", fd);
1600 
1601 			if (evsel->bpf_fd >= 0) {
1602 				int evt_fd = fd;
1603 				int bpf_fd = evsel->bpf_fd;
1604 
1605 				err = ioctl(evt_fd,
1606 					    PERF_EVENT_IOC_SET_BPF,
1607 					    bpf_fd);
1608 				if (err && errno != EEXIST) {
1609 					pr_err("failed to attach bpf fd %d: %s\n",
1610 					       bpf_fd, strerror(errno));
1611 					err = -EINVAL;
1612 					goto out_close;
1613 				}
1614 			}
1615 
1616 			set_rlimit = NO_CHANGE;
1617 
1618 			/*
1619 			 * If we succeeded but had to kill clockid, fail and
1620 			 * have perf_evsel__open_strerror() print us a nice
1621 			 * error.
1622 			 */
1623 			if (perf_missing_features.clockid ||
1624 			    perf_missing_features.clockid_wrong) {
1625 				err = -EINVAL;
1626 				goto out_close;
1627 			}
1628 		}
1629 	}
1630 
1631 	return 0;
1632 
1633 try_fallback:
1634 	/*
1635 	 * perf stat needs between 5 and 22 fds per CPU. When we run out
1636 	 * of them try to increase the limits.
1637 	 */
1638 	if (err == -EMFILE && set_rlimit < INCREASED_MAX) {
1639 		struct rlimit l;
1640 		int old_errno = errno;
1641 
1642 		if (getrlimit(RLIMIT_NOFILE, &l) == 0) {
1643 			if (set_rlimit == NO_CHANGE)
1644 				l.rlim_cur = l.rlim_max;
1645 			else {
1646 				l.rlim_cur = l.rlim_max + 1000;
1647 				l.rlim_max = l.rlim_cur;
1648 			}
1649 			if (setrlimit(RLIMIT_NOFILE, &l) == 0) {
1650 				set_rlimit++;
1651 				errno = old_errno;
1652 				goto retry_open;
1653 			}
1654 		}
1655 		errno = old_errno;
1656 	}
1657 
1658 	if (err != -EINVAL || cpu > 0 || thread > 0)
1659 		goto out_close;
1660 
1661 	/*
1662 	 * Must probe features in the order they were added to the
1663 	 * perf_event_attr interface.
1664 	 */
1665 	if (!perf_missing_features.write_backward && evsel->attr.write_backward) {
1666 		perf_missing_features.write_backward = true;
1667 		goto out_close;
1668 	} else if (!perf_missing_features.clockid_wrong && evsel->attr.use_clockid) {
1669 		perf_missing_features.clockid_wrong = true;
1670 		goto fallback_missing_features;
1671 	} else if (!perf_missing_features.clockid && evsel->attr.use_clockid) {
1672 		perf_missing_features.clockid = true;
1673 		goto fallback_missing_features;
1674 	} else if (!perf_missing_features.cloexec && (flags & PERF_FLAG_FD_CLOEXEC)) {
1675 		perf_missing_features.cloexec = true;
1676 		goto fallback_missing_features;
1677 	} else if (!perf_missing_features.mmap2 && evsel->attr.mmap2) {
1678 		perf_missing_features.mmap2 = true;
1679 		goto fallback_missing_features;
1680 	} else if (!perf_missing_features.exclude_guest &&
1681 		   (evsel->attr.exclude_guest || evsel->attr.exclude_host)) {
1682 		perf_missing_features.exclude_guest = true;
1683 		goto fallback_missing_features;
1684 	} else if (!perf_missing_features.sample_id_all) {
1685 		perf_missing_features.sample_id_all = true;
1686 		goto retry_sample_id;
1687 	} else if (!perf_missing_features.lbr_flags &&
1688 			(evsel->attr.branch_sample_type &
1689 			 (PERF_SAMPLE_BRANCH_NO_CYCLES |
1690 			  PERF_SAMPLE_BRANCH_NO_FLAGS))) {
1691 		perf_missing_features.lbr_flags = true;
1692 		goto fallback_missing_features;
1693 	}
1694 out_close:
1695 	do {
1696 		while (--thread >= 0) {
1697 			close(FD(evsel, cpu, thread));
1698 			FD(evsel, cpu, thread) = -1;
1699 		}
1700 		thread = nthreads;
1701 	} while (--cpu >= 0);
1702 	return err;
1703 }
1704 
1705 void perf_evsel__close(struct perf_evsel *evsel, int ncpus, int nthreads)
1706 {
1707 	if (evsel->fd == NULL)
1708 		return;
1709 
1710 	perf_evsel__close_fd(evsel, ncpus, nthreads);
1711 	perf_evsel__free_fd(evsel);
1712 }
1713 
1714 int perf_evsel__open_per_cpu(struct perf_evsel *evsel,
1715 			     struct cpu_map *cpus)
1716 {
1717 	return perf_evsel__open(evsel, cpus, NULL);
1718 }
1719 
1720 int perf_evsel__open_per_thread(struct perf_evsel *evsel,
1721 				struct thread_map *threads)
1722 {
1723 	return perf_evsel__open(evsel, NULL, threads);
1724 }
1725 
1726 static int perf_evsel__parse_id_sample(const struct perf_evsel *evsel,
1727 				       const union perf_event *event,
1728 				       struct perf_sample *sample)
1729 {
1730 	u64 type = evsel->attr.sample_type;
1731 	const u64 *array = event->sample.array;
1732 	bool swapped = evsel->needs_swap;
1733 	union u64_swap u;
1734 
1735 	array += ((event->header.size -
1736 		   sizeof(event->header)) / sizeof(u64)) - 1;
1737 
1738 	if (type & PERF_SAMPLE_IDENTIFIER) {
1739 		sample->id = *array;
1740 		array--;
1741 	}
1742 
1743 	if (type & PERF_SAMPLE_CPU) {
1744 		u.val64 = *array;
1745 		if (swapped) {
1746 			/* undo swap of u64, then swap on individual u32s */
1747 			u.val64 = bswap_64(u.val64);
1748 			u.val32[0] = bswap_32(u.val32[0]);
1749 		}
1750 
1751 		sample->cpu = u.val32[0];
1752 		array--;
1753 	}
1754 
1755 	if (type & PERF_SAMPLE_STREAM_ID) {
1756 		sample->stream_id = *array;
1757 		array--;
1758 	}
1759 
1760 	if (type & PERF_SAMPLE_ID) {
1761 		sample->id = *array;
1762 		array--;
1763 	}
1764 
1765 	if (type & PERF_SAMPLE_TIME) {
1766 		sample->time = *array;
1767 		array--;
1768 	}
1769 
1770 	if (type & PERF_SAMPLE_TID) {
1771 		u.val64 = *array;
1772 		if (swapped) {
1773 			/* undo swap of u64, then swap on individual u32s */
1774 			u.val64 = bswap_64(u.val64);
1775 			u.val32[0] = bswap_32(u.val32[0]);
1776 			u.val32[1] = bswap_32(u.val32[1]);
1777 		}
1778 
1779 		sample->pid = u.val32[0];
1780 		sample->tid = u.val32[1];
1781 		array--;
1782 	}
1783 
1784 	return 0;
1785 }
1786 
1787 static inline bool overflow(const void *endp, u16 max_size, const void *offset,
1788 			    u64 size)
1789 {
1790 	return size > max_size || offset + size > endp;
1791 }
1792 
1793 #define OVERFLOW_CHECK(offset, size, max_size)				\
1794 	do {								\
1795 		if (overflow(endp, (max_size), (offset), (size)))	\
1796 			return -EFAULT;					\
1797 	} while (0)
1798 
1799 #define OVERFLOW_CHECK_u64(offset) \
1800 	OVERFLOW_CHECK(offset, sizeof(u64), sizeof(u64))
1801 
1802 int perf_evsel__parse_sample(struct perf_evsel *evsel, union perf_event *event,
1803 			     struct perf_sample *data)
1804 {
1805 	u64 type = evsel->attr.sample_type;
1806 	bool swapped = evsel->needs_swap;
1807 	const u64 *array;
1808 	u16 max_size = event->header.size;
1809 	const void *endp = (void *)event + max_size;
1810 	u64 sz;
1811 
1812 	/*
1813 	 * used for cross-endian analysis. See git commit 65014ab3
1814 	 * for why this goofiness is needed.
1815 	 */
1816 	union u64_swap u;
1817 
1818 	memset(data, 0, sizeof(*data));
1819 	data->cpu = data->pid = data->tid = -1;
1820 	data->stream_id = data->id = data->time = -1ULL;
1821 	data->period = evsel->attr.sample_period;
1822 	data->cpumode = event->header.misc & PERF_RECORD_MISC_CPUMODE_MASK;
1823 
1824 	if (event->header.type != PERF_RECORD_SAMPLE) {
1825 		if (!evsel->attr.sample_id_all)
1826 			return 0;
1827 		return perf_evsel__parse_id_sample(evsel, event, data);
1828 	}
1829 
1830 	array = event->sample.array;
1831 
1832 	/*
1833 	 * The evsel's sample_size is based on PERF_SAMPLE_MASK which includes
1834 	 * up to PERF_SAMPLE_PERIOD.  After that overflow() must be used to
1835 	 * check the format does not go past the end of the event.
1836 	 */
1837 	if (evsel->sample_size + sizeof(event->header) > event->header.size)
1838 		return -EFAULT;
1839 
1840 	data->id = -1ULL;
1841 	if (type & PERF_SAMPLE_IDENTIFIER) {
1842 		data->id = *array;
1843 		array++;
1844 	}
1845 
1846 	if (type & PERF_SAMPLE_IP) {
1847 		data->ip = *array;
1848 		array++;
1849 	}
1850 
1851 	if (type & PERF_SAMPLE_TID) {
1852 		u.val64 = *array;
1853 		if (swapped) {
1854 			/* undo swap of u64, then swap on individual u32s */
1855 			u.val64 = bswap_64(u.val64);
1856 			u.val32[0] = bswap_32(u.val32[0]);
1857 			u.val32[1] = bswap_32(u.val32[1]);
1858 		}
1859 
1860 		data->pid = u.val32[0];
1861 		data->tid = u.val32[1];
1862 		array++;
1863 	}
1864 
1865 	if (type & PERF_SAMPLE_TIME) {
1866 		data->time = *array;
1867 		array++;
1868 	}
1869 
1870 	data->addr = 0;
1871 	if (type & PERF_SAMPLE_ADDR) {
1872 		data->addr = *array;
1873 		array++;
1874 	}
1875 
1876 	if (type & PERF_SAMPLE_ID) {
1877 		data->id = *array;
1878 		array++;
1879 	}
1880 
1881 	if (type & PERF_SAMPLE_STREAM_ID) {
1882 		data->stream_id = *array;
1883 		array++;
1884 	}
1885 
1886 	if (type & PERF_SAMPLE_CPU) {
1887 
1888 		u.val64 = *array;
1889 		if (swapped) {
1890 			/* undo swap of u64, then swap on individual u32s */
1891 			u.val64 = bswap_64(u.val64);
1892 			u.val32[0] = bswap_32(u.val32[0]);
1893 		}
1894 
1895 		data->cpu = u.val32[0];
1896 		array++;
1897 	}
1898 
1899 	if (type & PERF_SAMPLE_PERIOD) {
1900 		data->period = *array;
1901 		array++;
1902 	}
1903 
1904 	if (type & PERF_SAMPLE_READ) {
1905 		u64 read_format = evsel->attr.read_format;
1906 
1907 		OVERFLOW_CHECK_u64(array);
1908 		if (read_format & PERF_FORMAT_GROUP)
1909 			data->read.group.nr = *array;
1910 		else
1911 			data->read.one.value = *array;
1912 
1913 		array++;
1914 
1915 		if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) {
1916 			OVERFLOW_CHECK_u64(array);
1917 			data->read.time_enabled = *array;
1918 			array++;
1919 		}
1920 
1921 		if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) {
1922 			OVERFLOW_CHECK_u64(array);
1923 			data->read.time_running = *array;
1924 			array++;
1925 		}
1926 
1927 		/* PERF_FORMAT_ID is forced for PERF_SAMPLE_READ */
1928 		if (read_format & PERF_FORMAT_GROUP) {
1929 			const u64 max_group_nr = UINT64_MAX /
1930 					sizeof(struct sample_read_value);
1931 
1932 			if (data->read.group.nr > max_group_nr)
1933 				return -EFAULT;
1934 			sz = data->read.group.nr *
1935 			     sizeof(struct sample_read_value);
1936 			OVERFLOW_CHECK(array, sz, max_size);
1937 			data->read.group.values =
1938 					(struct sample_read_value *)array;
1939 			array = (void *)array + sz;
1940 		} else {
1941 			OVERFLOW_CHECK_u64(array);
1942 			data->read.one.id = *array;
1943 			array++;
1944 		}
1945 	}
1946 
1947 	if (type & PERF_SAMPLE_CALLCHAIN) {
1948 		const u64 max_callchain_nr = UINT64_MAX / sizeof(u64);
1949 
1950 		OVERFLOW_CHECK_u64(array);
1951 		data->callchain = (struct ip_callchain *)array++;
1952 		if (data->callchain->nr > max_callchain_nr)
1953 			return -EFAULT;
1954 		sz = data->callchain->nr * sizeof(u64);
1955 		OVERFLOW_CHECK(array, sz, max_size);
1956 		array = (void *)array + sz;
1957 	}
1958 
1959 	if (type & PERF_SAMPLE_RAW) {
1960 		OVERFLOW_CHECK_u64(array);
1961 		u.val64 = *array;
1962 		if (WARN_ONCE(swapped,
1963 			      "Endianness of raw data not corrected!\n")) {
1964 			/* undo swap of u64, then swap on individual u32s */
1965 			u.val64 = bswap_64(u.val64);
1966 			u.val32[0] = bswap_32(u.val32[0]);
1967 			u.val32[1] = bswap_32(u.val32[1]);
1968 		}
1969 		data->raw_size = u.val32[0];
1970 		array = (void *)array + sizeof(u32);
1971 
1972 		OVERFLOW_CHECK(array, data->raw_size, max_size);
1973 		data->raw_data = (void *)array;
1974 		array = (void *)array + data->raw_size;
1975 	}
1976 
1977 	if (type & PERF_SAMPLE_BRANCH_STACK) {
1978 		const u64 max_branch_nr = UINT64_MAX /
1979 					  sizeof(struct branch_entry);
1980 
1981 		OVERFLOW_CHECK_u64(array);
1982 		data->branch_stack = (struct branch_stack *)array++;
1983 
1984 		if (data->branch_stack->nr > max_branch_nr)
1985 			return -EFAULT;
1986 		sz = data->branch_stack->nr * sizeof(struct branch_entry);
1987 		OVERFLOW_CHECK(array, sz, max_size);
1988 		array = (void *)array + sz;
1989 	}
1990 
1991 	if (type & PERF_SAMPLE_REGS_USER) {
1992 		OVERFLOW_CHECK_u64(array);
1993 		data->user_regs.abi = *array;
1994 		array++;
1995 
1996 		if (data->user_regs.abi) {
1997 			u64 mask = evsel->attr.sample_regs_user;
1998 
1999 			sz = hweight_long(mask) * sizeof(u64);
2000 			OVERFLOW_CHECK(array, sz, max_size);
2001 			data->user_regs.mask = mask;
2002 			data->user_regs.regs = (u64 *)array;
2003 			array = (void *)array + sz;
2004 		}
2005 	}
2006 
2007 	if (type & PERF_SAMPLE_STACK_USER) {
2008 		OVERFLOW_CHECK_u64(array);
2009 		sz = *array++;
2010 
2011 		data->user_stack.offset = ((char *)(array - 1)
2012 					  - (char *) event);
2013 
2014 		if (!sz) {
2015 			data->user_stack.size = 0;
2016 		} else {
2017 			OVERFLOW_CHECK(array, sz, max_size);
2018 			data->user_stack.data = (char *)array;
2019 			array = (void *)array + sz;
2020 			OVERFLOW_CHECK_u64(array);
2021 			data->user_stack.size = *array++;
2022 			if (WARN_ONCE(data->user_stack.size > sz,
2023 				      "user stack dump failure\n"))
2024 				return -EFAULT;
2025 		}
2026 	}
2027 
2028 	if (type & PERF_SAMPLE_WEIGHT) {
2029 		OVERFLOW_CHECK_u64(array);
2030 		data->weight = *array;
2031 		array++;
2032 	}
2033 
2034 	data->data_src = PERF_MEM_DATA_SRC_NONE;
2035 	if (type & PERF_SAMPLE_DATA_SRC) {
2036 		OVERFLOW_CHECK_u64(array);
2037 		data->data_src = *array;
2038 		array++;
2039 	}
2040 
2041 	data->transaction = 0;
2042 	if (type & PERF_SAMPLE_TRANSACTION) {
2043 		OVERFLOW_CHECK_u64(array);
2044 		data->transaction = *array;
2045 		array++;
2046 	}
2047 
2048 	data->intr_regs.abi = PERF_SAMPLE_REGS_ABI_NONE;
2049 	if (type & PERF_SAMPLE_REGS_INTR) {
2050 		OVERFLOW_CHECK_u64(array);
2051 		data->intr_regs.abi = *array;
2052 		array++;
2053 
2054 		if (data->intr_regs.abi != PERF_SAMPLE_REGS_ABI_NONE) {
2055 			u64 mask = evsel->attr.sample_regs_intr;
2056 
2057 			sz = hweight_long(mask) * sizeof(u64);
2058 			OVERFLOW_CHECK(array, sz, max_size);
2059 			data->intr_regs.mask = mask;
2060 			data->intr_regs.regs = (u64 *)array;
2061 			array = (void *)array + sz;
2062 		}
2063 	}
2064 
2065 	return 0;
2066 }
2067 
2068 size_t perf_event__sample_event_size(const struct perf_sample *sample, u64 type,
2069 				     u64 read_format)
2070 {
2071 	size_t sz, result = sizeof(struct sample_event);
2072 
2073 	if (type & PERF_SAMPLE_IDENTIFIER)
2074 		result += sizeof(u64);
2075 
2076 	if (type & PERF_SAMPLE_IP)
2077 		result += sizeof(u64);
2078 
2079 	if (type & PERF_SAMPLE_TID)
2080 		result += sizeof(u64);
2081 
2082 	if (type & PERF_SAMPLE_TIME)
2083 		result += sizeof(u64);
2084 
2085 	if (type & PERF_SAMPLE_ADDR)
2086 		result += sizeof(u64);
2087 
2088 	if (type & PERF_SAMPLE_ID)
2089 		result += sizeof(u64);
2090 
2091 	if (type & PERF_SAMPLE_STREAM_ID)
2092 		result += sizeof(u64);
2093 
2094 	if (type & PERF_SAMPLE_CPU)
2095 		result += sizeof(u64);
2096 
2097 	if (type & PERF_SAMPLE_PERIOD)
2098 		result += sizeof(u64);
2099 
2100 	if (type & PERF_SAMPLE_READ) {
2101 		result += sizeof(u64);
2102 		if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
2103 			result += sizeof(u64);
2104 		if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
2105 			result += sizeof(u64);
2106 		/* PERF_FORMAT_ID is forced for PERF_SAMPLE_READ */
2107 		if (read_format & PERF_FORMAT_GROUP) {
2108 			sz = sample->read.group.nr *
2109 			     sizeof(struct sample_read_value);
2110 			result += sz;
2111 		} else {
2112 			result += sizeof(u64);
2113 		}
2114 	}
2115 
2116 	if (type & PERF_SAMPLE_CALLCHAIN) {
2117 		sz = (sample->callchain->nr + 1) * sizeof(u64);
2118 		result += sz;
2119 	}
2120 
2121 	if (type & PERF_SAMPLE_RAW) {
2122 		result += sizeof(u32);
2123 		result += sample->raw_size;
2124 	}
2125 
2126 	if (type & PERF_SAMPLE_BRANCH_STACK) {
2127 		sz = sample->branch_stack->nr * sizeof(struct branch_entry);
2128 		sz += sizeof(u64);
2129 		result += sz;
2130 	}
2131 
2132 	if (type & PERF_SAMPLE_REGS_USER) {
2133 		if (sample->user_regs.abi) {
2134 			result += sizeof(u64);
2135 			sz = hweight_long(sample->user_regs.mask) * sizeof(u64);
2136 			result += sz;
2137 		} else {
2138 			result += sizeof(u64);
2139 		}
2140 	}
2141 
2142 	if (type & PERF_SAMPLE_STACK_USER) {
2143 		sz = sample->user_stack.size;
2144 		result += sizeof(u64);
2145 		if (sz) {
2146 			result += sz;
2147 			result += sizeof(u64);
2148 		}
2149 	}
2150 
2151 	if (type & PERF_SAMPLE_WEIGHT)
2152 		result += sizeof(u64);
2153 
2154 	if (type & PERF_SAMPLE_DATA_SRC)
2155 		result += sizeof(u64);
2156 
2157 	if (type & PERF_SAMPLE_TRANSACTION)
2158 		result += sizeof(u64);
2159 
2160 	if (type & PERF_SAMPLE_REGS_INTR) {
2161 		if (sample->intr_regs.abi) {
2162 			result += sizeof(u64);
2163 			sz = hweight_long(sample->intr_regs.mask) * sizeof(u64);
2164 			result += sz;
2165 		} else {
2166 			result += sizeof(u64);
2167 		}
2168 	}
2169 
2170 	return result;
2171 }
2172 
2173 int perf_event__synthesize_sample(union perf_event *event, u64 type,
2174 				  u64 read_format,
2175 				  const struct perf_sample *sample,
2176 				  bool swapped)
2177 {
2178 	u64 *array;
2179 	size_t sz;
2180 	/*
2181 	 * used for cross-endian analysis. See git commit 65014ab3
2182 	 * for why this goofiness is needed.
2183 	 */
2184 	union u64_swap u;
2185 
2186 	array = event->sample.array;
2187 
2188 	if (type & PERF_SAMPLE_IDENTIFIER) {
2189 		*array = sample->id;
2190 		array++;
2191 	}
2192 
2193 	if (type & PERF_SAMPLE_IP) {
2194 		*array = sample->ip;
2195 		array++;
2196 	}
2197 
2198 	if (type & PERF_SAMPLE_TID) {
2199 		u.val32[0] = sample->pid;
2200 		u.val32[1] = sample->tid;
2201 		if (swapped) {
2202 			/*
2203 			 * Inverse of what is done in perf_evsel__parse_sample
2204 			 */
2205 			u.val32[0] = bswap_32(u.val32[0]);
2206 			u.val32[1] = bswap_32(u.val32[1]);
2207 			u.val64 = bswap_64(u.val64);
2208 		}
2209 
2210 		*array = u.val64;
2211 		array++;
2212 	}
2213 
2214 	if (type & PERF_SAMPLE_TIME) {
2215 		*array = sample->time;
2216 		array++;
2217 	}
2218 
2219 	if (type & PERF_SAMPLE_ADDR) {
2220 		*array = sample->addr;
2221 		array++;
2222 	}
2223 
2224 	if (type & PERF_SAMPLE_ID) {
2225 		*array = sample->id;
2226 		array++;
2227 	}
2228 
2229 	if (type & PERF_SAMPLE_STREAM_ID) {
2230 		*array = sample->stream_id;
2231 		array++;
2232 	}
2233 
2234 	if (type & PERF_SAMPLE_CPU) {
2235 		u.val32[0] = sample->cpu;
2236 		if (swapped) {
2237 			/*
2238 			 * Inverse of what is done in perf_evsel__parse_sample
2239 			 */
2240 			u.val32[0] = bswap_32(u.val32[0]);
2241 			u.val64 = bswap_64(u.val64);
2242 		}
2243 		*array = u.val64;
2244 		array++;
2245 	}
2246 
2247 	if (type & PERF_SAMPLE_PERIOD) {
2248 		*array = sample->period;
2249 		array++;
2250 	}
2251 
2252 	if (type & PERF_SAMPLE_READ) {
2253 		if (read_format & PERF_FORMAT_GROUP)
2254 			*array = sample->read.group.nr;
2255 		else
2256 			*array = sample->read.one.value;
2257 		array++;
2258 
2259 		if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) {
2260 			*array = sample->read.time_enabled;
2261 			array++;
2262 		}
2263 
2264 		if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) {
2265 			*array = sample->read.time_running;
2266 			array++;
2267 		}
2268 
2269 		/* PERF_FORMAT_ID is forced for PERF_SAMPLE_READ */
2270 		if (read_format & PERF_FORMAT_GROUP) {
2271 			sz = sample->read.group.nr *
2272 			     sizeof(struct sample_read_value);
2273 			memcpy(array, sample->read.group.values, sz);
2274 			array = (void *)array + sz;
2275 		} else {
2276 			*array = sample->read.one.id;
2277 			array++;
2278 		}
2279 	}
2280 
2281 	if (type & PERF_SAMPLE_CALLCHAIN) {
2282 		sz = (sample->callchain->nr + 1) * sizeof(u64);
2283 		memcpy(array, sample->callchain, sz);
2284 		array = (void *)array + sz;
2285 	}
2286 
2287 	if (type & PERF_SAMPLE_RAW) {
2288 		u.val32[0] = sample->raw_size;
2289 		if (WARN_ONCE(swapped,
2290 			      "Endianness of raw data not corrected!\n")) {
2291 			/*
2292 			 * Inverse of what is done in perf_evsel__parse_sample
2293 			 */
2294 			u.val32[0] = bswap_32(u.val32[0]);
2295 			u.val32[1] = bswap_32(u.val32[1]);
2296 			u.val64 = bswap_64(u.val64);
2297 		}
2298 		*array = u.val64;
2299 		array = (void *)array + sizeof(u32);
2300 
2301 		memcpy(array, sample->raw_data, sample->raw_size);
2302 		array = (void *)array + sample->raw_size;
2303 	}
2304 
2305 	if (type & PERF_SAMPLE_BRANCH_STACK) {
2306 		sz = sample->branch_stack->nr * sizeof(struct branch_entry);
2307 		sz += sizeof(u64);
2308 		memcpy(array, sample->branch_stack, sz);
2309 		array = (void *)array + sz;
2310 	}
2311 
2312 	if (type & PERF_SAMPLE_REGS_USER) {
2313 		if (sample->user_regs.abi) {
2314 			*array++ = sample->user_regs.abi;
2315 			sz = hweight_long(sample->user_regs.mask) * sizeof(u64);
2316 			memcpy(array, sample->user_regs.regs, sz);
2317 			array = (void *)array + sz;
2318 		} else {
2319 			*array++ = 0;
2320 		}
2321 	}
2322 
2323 	if (type & PERF_SAMPLE_STACK_USER) {
2324 		sz = sample->user_stack.size;
2325 		*array++ = sz;
2326 		if (sz) {
2327 			memcpy(array, sample->user_stack.data, sz);
2328 			array = (void *)array + sz;
2329 			*array++ = sz;
2330 		}
2331 	}
2332 
2333 	if (type & PERF_SAMPLE_WEIGHT) {
2334 		*array = sample->weight;
2335 		array++;
2336 	}
2337 
2338 	if (type & PERF_SAMPLE_DATA_SRC) {
2339 		*array = sample->data_src;
2340 		array++;
2341 	}
2342 
2343 	if (type & PERF_SAMPLE_TRANSACTION) {
2344 		*array = sample->transaction;
2345 		array++;
2346 	}
2347 
2348 	if (type & PERF_SAMPLE_REGS_INTR) {
2349 		if (sample->intr_regs.abi) {
2350 			*array++ = sample->intr_regs.abi;
2351 			sz = hweight_long(sample->intr_regs.mask) * sizeof(u64);
2352 			memcpy(array, sample->intr_regs.regs, sz);
2353 			array = (void *)array + sz;
2354 		} else {
2355 			*array++ = 0;
2356 		}
2357 	}
2358 
2359 	return 0;
2360 }
2361 
2362 struct format_field *perf_evsel__field(struct perf_evsel *evsel, const char *name)
2363 {
2364 	return pevent_find_field(evsel->tp_format, name);
2365 }
2366 
2367 void *perf_evsel__rawptr(struct perf_evsel *evsel, struct perf_sample *sample,
2368 			 const char *name)
2369 {
2370 	struct format_field *field = perf_evsel__field(evsel, name);
2371 	int offset;
2372 
2373 	if (!field)
2374 		return NULL;
2375 
2376 	offset = field->offset;
2377 
2378 	if (field->flags & FIELD_IS_DYNAMIC) {
2379 		offset = *(int *)(sample->raw_data + field->offset);
2380 		offset &= 0xffff;
2381 	}
2382 
2383 	return sample->raw_data + offset;
2384 }
2385 
2386 u64 format_field__intval(struct format_field *field, struct perf_sample *sample,
2387 			 bool needs_swap)
2388 {
2389 	u64 value;
2390 	void *ptr = sample->raw_data + field->offset;
2391 
2392 	switch (field->size) {
2393 	case 1:
2394 		return *(u8 *)ptr;
2395 	case 2:
2396 		value = *(u16 *)ptr;
2397 		break;
2398 	case 4:
2399 		value = *(u32 *)ptr;
2400 		break;
2401 	case 8:
2402 		memcpy(&value, ptr, sizeof(u64));
2403 		break;
2404 	default:
2405 		return 0;
2406 	}
2407 
2408 	if (!needs_swap)
2409 		return value;
2410 
2411 	switch (field->size) {
2412 	case 2:
2413 		return bswap_16(value);
2414 	case 4:
2415 		return bswap_32(value);
2416 	case 8:
2417 		return bswap_64(value);
2418 	default:
2419 		return 0;
2420 	}
2421 
2422 	return 0;
2423 }
2424 
2425 u64 perf_evsel__intval(struct perf_evsel *evsel, struct perf_sample *sample,
2426 		       const char *name)
2427 {
2428 	struct format_field *field = perf_evsel__field(evsel, name);
2429 
2430 	if (!field)
2431 		return 0;
2432 
2433 	return field ? format_field__intval(field, sample, evsel->needs_swap) : 0;
2434 }
2435 
2436 bool perf_evsel__fallback(struct perf_evsel *evsel, int err,
2437 			  char *msg, size_t msgsize)
2438 {
2439 	int paranoid;
2440 
2441 	if ((err == ENOENT || err == ENXIO || err == ENODEV) &&
2442 	    evsel->attr.type   == PERF_TYPE_HARDWARE &&
2443 	    evsel->attr.config == PERF_COUNT_HW_CPU_CYCLES) {
2444 		/*
2445 		 * If it's cycles then fall back to hrtimer based
2446 		 * cpu-clock-tick sw counter, which is always available even if
2447 		 * no PMU support.
2448 		 *
2449 		 * PPC returns ENXIO until 2.6.37 (behavior changed with commit
2450 		 * b0a873e).
2451 		 */
2452 		scnprintf(msg, msgsize, "%s",
2453 "The cycles event is not supported, trying to fall back to cpu-clock-ticks");
2454 
2455 		evsel->attr.type   = PERF_TYPE_SOFTWARE;
2456 		evsel->attr.config = PERF_COUNT_SW_CPU_CLOCK;
2457 
2458 		zfree(&evsel->name);
2459 		return true;
2460 	} else if (err == EACCES && !evsel->attr.exclude_kernel &&
2461 		   (paranoid = perf_event_paranoid()) > 1) {
2462 		const char *name = perf_evsel__name(evsel);
2463 		char *new_name;
2464 
2465 		if (asprintf(&new_name, "%s%su", name, strchr(name, ':') ? "" : ":") < 0)
2466 			return false;
2467 
2468 		if (evsel->name)
2469 			free(evsel->name);
2470 		evsel->name = new_name;
2471 		scnprintf(msg, msgsize,
2472 "kernel.perf_event_paranoid=%d, trying to fall back to excluding kernel samples", paranoid);
2473 		evsel->attr.exclude_kernel = 1;
2474 
2475 		return true;
2476 	}
2477 
2478 	return false;
2479 }
2480 
2481 static bool find_process(const char *name)
2482 {
2483 	size_t len = strlen(name);
2484 	DIR *dir;
2485 	struct dirent *d;
2486 	int ret = -1;
2487 
2488 	dir = opendir(procfs__mountpoint());
2489 	if (!dir)
2490 		return false;
2491 
2492 	/* Walk through the directory. */
2493 	while (ret && (d = readdir(dir)) != NULL) {
2494 		char path[PATH_MAX];
2495 		char *data;
2496 		size_t size;
2497 
2498 		if ((d->d_type != DT_DIR) ||
2499 		     !strcmp(".", d->d_name) ||
2500 		     !strcmp("..", d->d_name))
2501 			continue;
2502 
2503 		scnprintf(path, sizeof(path), "%s/%s/comm",
2504 			  procfs__mountpoint(), d->d_name);
2505 
2506 		if (filename__read_str(path, &data, &size))
2507 			continue;
2508 
2509 		ret = strncmp(name, data, len);
2510 		free(data);
2511 	}
2512 
2513 	closedir(dir);
2514 	return ret ? false : true;
2515 }
2516 
2517 int perf_evsel__open_strerror(struct perf_evsel *evsel, struct target *target,
2518 			      int err, char *msg, size_t size)
2519 {
2520 	char sbuf[STRERR_BUFSIZE];
2521 	int printed = 0;
2522 
2523 	switch (err) {
2524 	case EPERM:
2525 	case EACCES:
2526 		if (err == EPERM)
2527 			printed = scnprintf(msg, size,
2528 				"No permission to enable %s event.\n\n",
2529 				perf_evsel__name(evsel));
2530 
2531 		return scnprintf(msg + printed, size - printed,
2532 		 "You may not have permission to collect %sstats.\n\n"
2533 		 "Consider tweaking /proc/sys/kernel/perf_event_paranoid,\n"
2534 		 "which controls use of the performance events system by\n"
2535 		 "unprivileged users (without CAP_SYS_ADMIN).\n\n"
2536 		 "The current value is %d:\n\n"
2537 		 "  -1: Allow use of (almost) all events by all users\n"
2538 		 ">= 0: Disallow raw tracepoint access by users without CAP_IOC_LOCK\n"
2539 		 ">= 1: Disallow CPU event access by users without CAP_SYS_ADMIN\n"
2540 		 ">= 2: Disallow kernel profiling by users without CAP_SYS_ADMIN\n\n"
2541 		 "To make this setting permanent, edit /etc/sysctl.conf too, e.g.:\n\n"
2542 		 "	kernel.perf_event_paranoid = -1\n" ,
2543 				 target->system_wide ? "system-wide " : "",
2544 				 perf_event_paranoid());
2545 	case ENOENT:
2546 		return scnprintf(msg, size, "The %s event is not supported.",
2547 				 perf_evsel__name(evsel));
2548 	case EMFILE:
2549 		return scnprintf(msg, size, "%s",
2550 			 "Too many events are opened.\n"
2551 			 "Probably the maximum number of open file descriptors has been reached.\n"
2552 			 "Hint: Try again after reducing the number of events.\n"
2553 			 "Hint: Try increasing the limit with 'ulimit -n <limit>'");
2554 	case ENOMEM:
2555 		if ((evsel->attr.sample_type & PERF_SAMPLE_CALLCHAIN) != 0 &&
2556 		    access("/proc/sys/kernel/perf_event_max_stack", F_OK) == 0)
2557 			return scnprintf(msg, size,
2558 					 "Not enough memory to setup event with callchain.\n"
2559 					 "Hint: Try tweaking /proc/sys/kernel/perf_event_max_stack\n"
2560 					 "Hint: Current value: %d", sysctl_perf_event_max_stack);
2561 		break;
2562 	case ENODEV:
2563 		if (target->cpu_list)
2564 			return scnprintf(msg, size, "%s",
2565 	 "No such device - did you specify an out-of-range profile CPU?");
2566 		break;
2567 	case EOPNOTSUPP:
2568 		if (evsel->attr.sample_period != 0)
2569 			return scnprintf(msg, size, "%s",
2570 	"PMU Hardware doesn't support sampling/overflow-interrupts.");
2571 		if (evsel->attr.precise_ip)
2572 			return scnprintf(msg, size, "%s",
2573 	"\'precise\' request may not be supported. Try removing 'p' modifier.");
2574 #if defined(__i386__) || defined(__x86_64__)
2575 		if (evsel->attr.type == PERF_TYPE_HARDWARE)
2576 			return scnprintf(msg, size, "%s",
2577 	"No hardware sampling interrupt available.\n"
2578 	"No APIC? If so then you can boot the kernel with the \"lapic\" boot parameter to force-enable it.");
2579 #endif
2580 		break;
2581 	case EBUSY:
2582 		if (find_process("oprofiled"))
2583 			return scnprintf(msg, size,
2584 	"The PMU counters are busy/taken by another profiler.\n"
2585 	"We found oprofile daemon running, please stop it and try again.");
2586 		break;
2587 	case EINVAL:
2588 		if (evsel->attr.write_backward && perf_missing_features.write_backward)
2589 			return scnprintf(msg, size, "Reading from overwrite event is not supported by this kernel.");
2590 		if (perf_missing_features.clockid)
2591 			return scnprintf(msg, size, "clockid feature not supported.");
2592 		if (perf_missing_features.clockid_wrong)
2593 			return scnprintf(msg, size, "wrong clockid (%d).", clockid);
2594 		break;
2595 	default:
2596 		break;
2597 	}
2598 
2599 	return scnprintf(msg, size,
2600 	"The sys_perf_event_open() syscall returned with %d (%s) for event (%s).\n"
2601 	"/bin/dmesg may provide additional information.\n"
2602 	"No CONFIG_PERF_EVENTS=y kernel support configured?",
2603 			 err, str_error_r(err, sbuf, sizeof(sbuf)),
2604 			 perf_evsel__name(evsel));
2605 }
2606 
2607 char *perf_evsel__env_arch(struct perf_evsel *evsel)
2608 {
2609 	if (evsel && evsel->evlist && evsel->evlist->env)
2610 		return evsel->evlist->env->arch;
2611 	return NULL;
2612 }
2613