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   1// SPDX-License-Identifier: GPL-2.0-only 
   2
   3#include "util/debug.h"
   4#include "util/dso.h"
   5#include "util/event.h"
   6#include "util/evlist.h"
   7#include "util/machine.h"
   8#include "util/map.h"
   9#include "util/map_symbol.h"
  10#include "util/branch.h"
  11#include "util/memswap.h"
  12#include "util/namespaces.h"
  13#include "util/session.h"
  14#include "util/stat.h"
  15#include "util/symbol.h"
  16#include "util/synthetic-events.h"
  17#include "util/target.h"
  18#include "util/time-utils.h"
  19#include "util/cgroup.h"
  20#include <linux/bitops.h>
  21#include <linux/kernel.h>
  22#include <linux/string.h>
  23#include <linux/zalloc.h>
  24#include <linux/perf_event.h>
  25#include <asm/bug.h>
  26#include <perf/evsel.h>
  27#include <perf/cpumap.h>
  28#include <internal/lib.h> // page_size
  29#include <internal/threadmap.h>
  30#include <perf/threadmap.h>
  31#include <symbol/kallsyms.h>
  32#include <dirent.h>
  33#include <errno.h>
  34#include <inttypes.h>
  35#include <stdio.h>
  36#include <string.h>
  37#include <uapi/linux/mman.h> /* To get things like MAP_HUGETLB even on older libc headers */
  38#include <api/fs/fs.h>
  39#include <api/io.h>
  40#include <sys/types.h>
  41#include <sys/stat.h>
  42#include <fcntl.h>
  43#include <unistd.h>
  44
  45#define DEFAULT_PROC_MAP_PARSE_TIMEOUT 500
  46
  47unsigned int proc_map_timeout = DEFAULT_PROC_MAP_PARSE_TIMEOUT;
  48
  49int perf_tool__process_synth_event(struct perf_tool *tool,
  50				   union perf_event *event,
  51				   struct machine *machine,
  52				   perf_event__handler_t process)
  53{
  54	struct perf_sample synth_sample = {
  55		.pid	   = -1,
  56		.tid	   = -1,
  57		.time	   = -1,
  58		.stream_id = -1,
  59		.cpu	   = -1,
  60		.period	   = 1,
  61		.cpumode   = event->header.misc & PERF_RECORD_MISC_CPUMODE_MASK,
  62	};
  63
  64	return process(tool, event, &synth_sample, machine);
  65};
  66
  67/*
  68 * Assumes that the first 4095 bytes of /proc/pid/stat contains
  69 * the comm, tgid and ppid.
  70 */
  71static int perf_event__get_comm_ids(pid_t pid, pid_t tid, char *comm, size_t len,
  72				    pid_t *tgid, pid_t *ppid, bool *kernel)
  73{
  74	char bf[4096];
  75	int fd;
  76	size_t size = 0;
  77	ssize_t n;
  78	char *name, *tgids, *ppids, *vmpeak, *threads;
  79
  80	*tgid = -1;
  81	*ppid = -1;
  82
  83	if (pid)
  84		snprintf(bf, sizeof(bf), "/proc/%d/task/%d/status", pid, tid);
  85	else
  86		snprintf(bf, sizeof(bf), "/proc/%d/status", tid);
  87
  88	fd = open(bf, O_RDONLY);
  89	if (fd < 0) {
  90		pr_debug("couldn't open %s\n", bf);
  91		return -1;
  92	}
  93
  94	n = read(fd, bf, sizeof(bf) - 1);
  95	close(fd);
  96	if (n <= 0) {
  97		pr_warning("Couldn't get COMM, tigd and ppid for pid %d\n",
  98			   tid);
  99		return -1;
 100	}
 101	bf[n] = '\0';
 102
 103	name = strstr(bf, "Name:");
 104	tgids = strstr(name ?: bf, "Tgid:");
 105	ppids = strstr(tgids ?: bf, "PPid:");
 106	vmpeak = strstr(ppids ?: bf, "VmPeak:");
 107
 108	if (vmpeak)
 109		threads = NULL;
 110	else
 111		threads = strstr(ppids ?: bf, "Threads:");
 112
 113	if (name) {
 114		char *nl;
 115
 116		name = skip_spaces(name + 5);  /* strlen("Name:") */
 117		nl = strchr(name, '\n');
 118		if (nl)
 119			*nl = '\0';
 120
 121		size = strlen(name);
 122		if (size >= len)
 123			size = len - 1;
 124		memcpy(comm, name, size);
 125		comm[size] = '\0';
 126	} else {
 127		pr_debug("Name: string not found for pid %d\n", tid);
 128	}
 129
 130	if (tgids) {
 131		tgids += 5;  /* strlen("Tgid:") */
 132		*tgid = atoi(tgids);
 133	} else {
 134		pr_debug("Tgid: string not found for pid %d\n", tid);
 135	}
 136
 137	if (ppids) {
 138		ppids += 5;  /* strlen("PPid:") */
 139		*ppid = atoi(ppids);
 140	} else {
 141		pr_debug("PPid: string not found for pid %d\n", tid);
 142	}
 143
 144	if (!vmpeak && threads)
 145		*kernel = true;
 146	else
 147		*kernel = false;
 148
 149	return 0;
 150}
 151
 152static int perf_event__prepare_comm(union perf_event *event, pid_t pid, pid_t tid,
 153				    struct machine *machine,
 154				    pid_t *tgid, pid_t *ppid, bool *kernel)
 155{
 156	size_t size;
 157
 158	*ppid = -1;
 159
 160	memset(&event->comm, 0, sizeof(event->comm));
 161
 162	if (machine__is_host(machine)) {
 163		if (perf_event__get_comm_ids(pid, tid, event->comm.comm,
 164					     sizeof(event->comm.comm),
 165					     tgid, ppid, kernel) != 0) {
 166			return -1;
 167		}
 168	} else {
 169		*tgid = machine->pid;
 170	}
 171
 172	if (*tgid < 0)
 173		return -1;
 174
 175	event->comm.pid = *tgid;
 176	event->comm.header.type = PERF_RECORD_COMM;
 177
 178	size = strlen(event->comm.comm) + 1;
 179	size = PERF_ALIGN(size, sizeof(u64));
 180	memset(event->comm.comm + size, 0, machine->id_hdr_size);
 181	event->comm.header.size = (sizeof(event->comm) -
 182				(sizeof(event->comm.comm) - size) +
 183				machine->id_hdr_size);
 184	event->comm.tid = tid;
 185
 186	return 0;
 187}
 188
 189pid_t perf_event__synthesize_comm(struct perf_tool *tool,
 190					 union perf_event *event, pid_t pid,
 191					 perf_event__handler_t process,
 192					 struct machine *machine)
 193{
 194	pid_t tgid, ppid;
 195	bool kernel_thread;
 196
 197	if (perf_event__prepare_comm(event, 0, pid, machine, &tgid, &ppid,
 198				     &kernel_thread) != 0)
 199		return -1;
 200
 201	if (perf_tool__process_synth_event(tool, event, machine, process) != 0)
 202		return -1;
 203
 204	return tgid;
 205}
 206
 207static void perf_event__get_ns_link_info(pid_t pid, const char *ns,
 208					 struct perf_ns_link_info *ns_link_info)
 209{
 210	struct stat64 st;
 211	char proc_ns[128];
 212
 213	sprintf(proc_ns, "/proc/%u/ns/%s", pid, ns);
 214	if (stat64(proc_ns, &st) == 0) {
 215		ns_link_info->dev = st.st_dev;
 216		ns_link_info->ino = st.st_ino;
 217	}
 218}
 219
 220int perf_event__synthesize_namespaces(struct perf_tool *tool,
 221				      union perf_event *event,
 222				      pid_t pid, pid_t tgid,
 223				      perf_event__handler_t process,
 224				      struct machine *machine)
 225{
 226	u32 idx;
 227	struct perf_ns_link_info *ns_link_info;
 228
 229	if (!tool || !tool->namespace_events)
 230		return 0;
 231
 232	memset(&event->namespaces, 0, (sizeof(event->namespaces) +
 233	       (NR_NAMESPACES * sizeof(struct perf_ns_link_info)) +
 234	       machine->id_hdr_size));
 235
 236	event->namespaces.pid = tgid;
 237	event->namespaces.tid = pid;
 238
 239	event->namespaces.nr_namespaces = NR_NAMESPACES;
 240
 241	ns_link_info = event->namespaces.link_info;
 242
 243	for (idx = 0; idx < event->namespaces.nr_namespaces; idx++)
 244		perf_event__get_ns_link_info(pid, perf_ns__name(idx),
 245					     &ns_link_info[idx]);
 246
 247	event->namespaces.header.type = PERF_RECORD_NAMESPACES;
 248
 249	event->namespaces.header.size = (sizeof(event->namespaces) +
 250			(NR_NAMESPACES * sizeof(struct perf_ns_link_info)) +
 251			machine->id_hdr_size);
 252
 253	if (perf_tool__process_synth_event(tool, event, machine, process) != 0)
 254		return -1;
 255
 256	return 0;
 257}
 258
 259static int perf_event__synthesize_fork(struct perf_tool *tool,
 260				       union perf_event *event,
 261				       pid_t pid, pid_t tgid, pid_t ppid,
 262				       perf_event__handler_t process,
 263				       struct machine *machine)
 264{
 265	memset(&event->fork, 0, sizeof(event->fork) + machine->id_hdr_size);
 266
 267	/*
 268	 * for main thread set parent to ppid from status file. For other
 269	 * threads set parent pid to main thread. ie., assume main thread
 270	 * spawns all threads in a process
 271	*/
 272	if (tgid == pid) {
 273		event->fork.ppid = ppid;
 274		event->fork.ptid = ppid;
 275	} else {
 276		event->fork.ppid = tgid;
 277		event->fork.ptid = tgid;
 278	}
 279	event->fork.pid  = tgid;
 280	event->fork.tid  = pid;
 281	event->fork.header.type = PERF_RECORD_FORK;
 282	event->fork.header.misc = PERF_RECORD_MISC_FORK_EXEC;
 283
 284	event->fork.header.size = (sizeof(event->fork) + machine->id_hdr_size);
 285
 286	if (perf_tool__process_synth_event(tool, event, machine, process) != 0)
 287		return -1;
 288
 289	return 0;
 290}
 291
 292static bool read_proc_maps_line(struct io *io, __u64 *start, __u64 *end,
 293				u32 *prot, u32 *flags, __u64 *offset,
 294				u32 *maj, u32 *min,
 295				__u64 *inode,
 296				ssize_t pathname_size, char *pathname)
 297{
 298	__u64 temp;
 299	int ch;
 300	char *start_pathname = pathname;
 301
 302	if (io__get_hex(io, start) != '-')
 303		return false;
 304	if (io__get_hex(io, end) != ' ')
 305		return false;
 306
 307	/* map protection and flags bits */
 308	*prot = 0;
 309	ch = io__get_char(io);
 310	if (ch == 'r')
 311		*prot |= PROT_READ;
 312	else if (ch != '-')
 313		return false;
 314	ch = io__get_char(io);
 315	if (ch == 'w')
 316		*prot |= PROT_WRITE;
 317	else if (ch != '-')
 318		return false;
 319	ch = io__get_char(io);
 320	if (ch == 'x')
 321		*prot |= PROT_EXEC;
 322	else if (ch != '-')
 323		return false;
 324	ch = io__get_char(io);
 325	if (ch == 's')
 326		*flags = MAP_SHARED;
 327	else if (ch == 'p')
 328		*flags = MAP_PRIVATE;
 329	else
 330		return false;
 331	if (io__get_char(io) != ' ')
 332		return false;
 333
 334	if (io__get_hex(io, offset) != ' ')
 335		return false;
 336
 337	if (io__get_hex(io, &temp) != ':')
 338		return false;
 339	*maj = temp;
 340	if (io__get_hex(io, &temp) != ' ')
 341		return false;
 342	*min = temp;
 343
 344	ch = io__get_dec(io, inode);
 345	if (ch != ' ') {
 346		*pathname = '\0';
 347		return ch == '\n';
 348	}
 349	do {
 350		ch = io__get_char(io);
 351	} while (ch == ' ');
 352	while (true) {
 353		if (ch < 0)
 354			return false;
 355		if (ch == '\0' || ch == '\n' ||
 356		    (pathname + 1 - start_pathname) >= pathname_size) {
 357			*pathname = '\0';
 358			return true;
 359		}
 360		*pathname++ = ch;
 361		ch = io__get_char(io);
 362	}
 363}
 364
 365static void perf_record_mmap2__read_build_id(struct perf_record_mmap2 *event,
 366					     bool is_kernel)
 367{
 368	struct build_id bid;
 369	int rc;
 370
 371	if (is_kernel)
 372		rc = sysfs__read_build_id("/sys/kernel/notes", &bid);
 373	else
 374		rc = filename__read_build_id(event->filename, &bid) > 0 ? 0 : -1;
 375
 376	if (rc == 0) {
 377		memcpy(event->build_id, bid.data, sizeof(bid.data));
 378		event->build_id_size = (u8) bid.size;
 379		event->header.misc |= PERF_RECORD_MISC_MMAP_BUILD_ID;
 380		event->__reserved_1 = 0;
 381		event->__reserved_2 = 0;
 382	} else {
 383		if (event->filename[0] == '/') {
 384			pr_debug2("Failed to read build ID for %s\n",
 385				  event->filename);
 386		}
 387	}
 388}
 389
 390int perf_event__synthesize_mmap_events(struct perf_tool *tool,
 391				       union perf_event *event,
 392				       pid_t pid, pid_t tgid,
 393				       perf_event__handler_t process,
 394				       struct machine *machine,
 395				       bool mmap_data)
 396{
 397	unsigned long long t;
 398	char bf[BUFSIZ];
 399	struct io io;
 400	bool truncation = false;
 401	unsigned long long timeout = proc_map_timeout * 1000000ULL;
 402	int rc = 0;
 403	const char *hugetlbfs_mnt = hugetlbfs__mountpoint();
 404	int hugetlbfs_mnt_len = hugetlbfs_mnt ? strlen(hugetlbfs_mnt) : 0;
 405
 406	if (machine__is_default_guest(machine))
 407		return 0;
 408
 409	snprintf(bf, sizeof(bf), "%s/proc/%d/task/%d/maps",
 410		machine->root_dir, pid, pid);
 411
 412	io.fd = open(bf, O_RDONLY, 0);
 413	if (io.fd < 0) {
 414		/*
 415		 * We raced with a task exiting - just return:
 416		 */
 417		pr_debug("couldn't open %s\n", bf);
 418		return -1;
 419	}
 420	io__init(&io, io.fd, bf, sizeof(bf));
 421
 422	event->header.type = PERF_RECORD_MMAP2;
 423	t = rdclock();
 424
 425	while (!io.eof) {
 426		static const char anonstr[] = "//anon";
 427		size_t size, aligned_size;
 428
 429		/* ensure null termination since stack will be reused. */
 430		event->mmap2.filename[0] = '\0';
 431
 432		/* 00400000-0040c000 r-xp 00000000 fd:01 41038  /bin/cat */
 433		if (!read_proc_maps_line(&io,
 434					&event->mmap2.start,
 435					&event->mmap2.len,
 436					&event->mmap2.prot,
 437					&event->mmap2.flags,
 438					&event->mmap2.pgoff,
 439					&event->mmap2.maj,
 440					&event->mmap2.min,
 441					&event->mmap2.ino,
 442					sizeof(event->mmap2.filename),
 443					event->mmap2.filename))
 444			continue;
 445
 446		if ((rdclock() - t) > timeout) {
 447			pr_warning("Reading %s/proc/%d/task/%d/maps time out. "
 448				   "You may want to increase "
 449				   "the time limit by --proc-map-timeout\n",
 450				   machine->root_dir, pid, pid);
 451			truncation = true;
 452			goto out;
 453		}
 454
 455		event->mmap2.ino_generation = 0;
 456
 457		/*
 458		 * Just like the kernel, see __perf_event_mmap in kernel/perf_event.c
 459		 */
 460		if (machine__is_host(machine))
 461			event->header.misc = PERF_RECORD_MISC_USER;
 462		else
 463			event->header.misc = PERF_RECORD_MISC_GUEST_USER;
 464
 465		if ((event->mmap2.prot & PROT_EXEC) == 0) {
 466			if (!mmap_data || (event->mmap2.prot & PROT_READ) == 0)
 467				continue;
 468
 469			event->header.misc |= PERF_RECORD_MISC_MMAP_DATA;
 470		}
 471
 472out:
 473		if (truncation)
 474			event->header.misc |= PERF_RECORD_MISC_PROC_MAP_PARSE_TIMEOUT;
 475
 476		if (!strcmp(event->mmap2.filename, ""))
 477			strcpy(event->mmap2.filename, anonstr);
 478
 479		if (hugetlbfs_mnt_len &&
 480		    !strncmp(event->mmap2.filename, hugetlbfs_mnt,
 481			     hugetlbfs_mnt_len)) {
 482			strcpy(event->mmap2.filename, anonstr);
 483			event->mmap2.flags |= MAP_HUGETLB;
 484		}
 485
 486		size = strlen(event->mmap2.filename) + 1;
 487		aligned_size = PERF_ALIGN(size, sizeof(u64));
 488		event->mmap2.len -= event->mmap.start;
 489		event->mmap2.header.size = (sizeof(event->mmap2) -
 490					(sizeof(event->mmap2.filename) - aligned_size));
 491		memset(event->mmap2.filename + size, 0, machine->id_hdr_size +
 492			(aligned_size - size));
 493		event->mmap2.header.size += machine->id_hdr_size;
 494		event->mmap2.pid = tgid;
 495		event->mmap2.tid = pid;
 496
 497		if (symbol_conf.buildid_mmap2)
 498			perf_record_mmap2__read_build_id(&event->mmap2, false);
 499
 500		if (perf_tool__process_synth_event(tool, event, machine, process) != 0) {
 501			rc = -1;
 502			break;
 503		}
 504
 505		if (truncation)
 506			break;
 507	}
 508
 509	close(io.fd);
 510	return rc;
 511}
 512
 513#ifdef HAVE_FILE_HANDLE
 514static int perf_event__synthesize_cgroup(struct perf_tool *tool,
 515					 union perf_event *event,
 516					 char *path, size_t mount_len,
 517					 perf_event__handler_t process,
 518					 struct machine *machine)
 519{
 520	size_t event_size = sizeof(event->cgroup) - sizeof(event->cgroup.path);
 521	size_t path_len = strlen(path) - mount_len + 1;
 522	struct {
 523		struct file_handle fh;
 524		uint64_t cgroup_id;
 525	} handle;
 526	int mount_id;
 527
 528	while (path_len % sizeof(u64))
 529		path[mount_len + path_len++] = '\0';
 530
 531	memset(&event->cgroup, 0, event_size);
 532
 533	event->cgroup.header.type = PERF_RECORD_CGROUP;
 534	event->cgroup.header.size = event_size + path_len + machine->id_hdr_size;
 535
 536	handle.fh.handle_bytes = sizeof(handle.cgroup_id);
 537	if (name_to_handle_at(AT_FDCWD, path, &handle.fh, &mount_id, 0) < 0) {
 538		pr_debug("stat failed: %s\n", path);
 539		return -1;
 540	}
 541
 542	event->cgroup.id = handle.cgroup_id;
 543	strncpy(event->cgroup.path, path + mount_len, path_len);
 544	memset(event->cgroup.path + path_len, 0, machine->id_hdr_size);
 545
 546	if (perf_tool__process_synth_event(tool, event, machine, process) < 0) {
 547		pr_debug("process synth event failed\n");
 548		return -1;
 549	}
 550
 551	return 0;
 552}
 553
 554static int perf_event__walk_cgroup_tree(struct perf_tool *tool,
 555					union perf_event *event,
 556					char *path, size_t mount_len,
 557					perf_event__handler_t process,
 558					struct machine *machine)
 559{
 560	size_t pos = strlen(path);
 561	DIR *d;
 562	struct dirent *dent;
 563	int ret = 0;
 564
 565	if (perf_event__synthesize_cgroup(tool, event, path, mount_len,
 566					  process, machine) < 0)
 567		return -1;
 568
 569	d = opendir(path);
 570	if (d == NULL) {
 571		pr_debug("failed to open directory: %s\n", path);
 572		return -1;
 573	}
 574
 575	while ((dent = readdir(d)) != NULL) {
 576		if (dent->d_type != DT_DIR)
 577			continue;
 578		if (!strcmp(dent->d_name, ".") ||
 579		    !strcmp(dent->d_name, ".."))
 580			continue;
 581
 582		/* any sane path should be less than PATH_MAX */
 583		if (strlen(path) + strlen(dent->d_name) + 1 >= PATH_MAX)
 584			continue;
 585
 586		if (path[pos - 1] != '/')
 587			strcat(path, "/");
 588		strcat(path, dent->d_name);
 589
 590		ret = perf_event__walk_cgroup_tree(tool, event, path,
 591						   mount_len, process, machine);
 592		if (ret < 0)
 593			break;
 594
 595		path[pos] = '\0';
 596	}
 597
 598	closedir(d);
 599	return ret;
 600}
 601
 602int perf_event__synthesize_cgroups(struct perf_tool *tool,
 603				   perf_event__handler_t process,
 604				   struct machine *machine)
 605{
 606	union perf_event event;
 607	char cgrp_root[PATH_MAX];
 608	size_t mount_len;  /* length of mount point in the path */
 609
 610	if (!tool || !tool->cgroup_events)
 611		return 0;
 612
 613	if (cgroupfs_find_mountpoint(cgrp_root, PATH_MAX, "perf_event") < 0) {
 614		pr_debug("cannot find cgroup mount point\n");
 615		return -1;
 616	}
 617
 618	mount_len = strlen(cgrp_root);
 619	/* make sure the path starts with a slash (after mount point) */
 620	strcat(cgrp_root, "/");
 621
 622	if (perf_event__walk_cgroup_tree(tool, &event, cgrp_root, mount_len,
 623					 process, machine) < 0)
 624		return -1;
 625
 626	return 0;
 627}
 628#else
 629int perf_event__synthesize_cgroups(struct perf_tool *tool __maybe_unused,
 630				   perf_event__handler_t process __maybe_unused,
 631				   struct machine *machine __maybe_unused)
 632{
 633	return -1;
 634}
 635#endif
 636
 637int perf_event__synthesize_modules(struct perf_tool *tool, perf_event__handler_t process,
 638				   struct machine *machine)
 639{
 640	int rc = 0;
 641	struct map *pos;
 642	struct maps *maps = machine__kernel_maps(machine);
 643	union perf_event *event;
 644	size_t size = symbol_conf.buildid_mmap2 ?
 645			sizeof(event->mmap2) : sizeof(event->mmap);
 646
 647	event = zalloc(size + machine->id_hdr_size);
 648	if (event == NULL) {
 649		pr_debug("Not enough memory synthesizing mmap event "
 650			 "for kernel modules\n");
 651		return -1;
 652	}
 653
 654	/*
 655	 * kernel uses 0 for user space maps, see kernel/perf_event.c
 656	 * __perf_event_mmap
 657	 */
 658	if (machine__is_host(machine))
 659		event->header.misc = PERF_RECORD_MISC_KERNEL;
 660	else
 661		event->header.misc = PERF_RECORD_MISC_GUEST_KERNEL;
 662
 663	maps__for_each_entry(maps, pos) {
 664		if (!__map__is_kmodule(pos))
 665			continue;
 666
 667		if (symbol_conf.buildid_mmap2) {
 668			size = PERF_ALIGN(pos->dso->long_name_len + 1, sizeof(u64));
 669			event->mmap2.header.type = PERF_RECORD_MMAP2;
 670			event->mmap2.header.size = (sizeof(event->mmap2) -
 671						(sizeof(event->mmap2.filename) - size));
 672			memset(event->mmap2.filename + size, 0, machine->id_hdr_size);
 673			event->mmap2.header.size += machine->id_hdr_size;
 674			event->mmap2.start = pos->start;
 675			event->mmap2.len   = pos->end - pos->start;
 676			event->mmap2.pid   = machine->pid;
 677
 678			memcpy(event->mmap2.filename, pos->dso->long_name,
 679			       pos->dso->long_name_len + 1);
 680
 681			perf_record_mmap2__read_build_id(&event->mmap2, false);
 682		} else {
 683			size = PERF_ALIGN(pos->dso->long_name_len + 1, sizeof(u64));
 684			event->mmap.header.type = PERF_RECORD_MMAP;
 685			event->mmap.header.size = (sizeof(event->mmap) -
 686						(sizeof(event->mmap.filename) - size));
 687			memset(event->mmap.filename + size, 0, machine->id_hdr_size);
 688			event->mmap.header.size += machine->id_hdr_size;
 689			event->mmap.start = pos->start;
 690			event->mmap.len   = pos->end - pos->start;
 691			event->mmap.pid   = machine->pid;
 692
 693			memcpy(event->mmap.filename, pos->dso->long_name,
 694			       pos->dso->long_name_len + 1);
 695		}
 696
 697		if (perf_tool__process_synth_event(tool, event, machine, process) != 0) {
 698			rc = -1;
 699			break;
 700		}
 701	}
 702
 703	free(event);
 704	return rc;
 705}
 706
 707static int filter_task(const struct dirent *dirent)
 708{
 709	return isdigit(dirent->d_name[0]);
 710}
 711
 712static int __event__synthesize_thread(union perf_event *comm_event,
 713				      union perf_event *mmap_event,
 714				      union perf_event *fork_event,
 715				      union perf_event *namespaces_event,
 716				      pid_t pid, int full, perf_event__handler_t process,
 717				      struct perf_tool *tool, struct machine *machine, bool mmap_data)
 718{
 719	char filename[PATH_MAX];
 720	struct dirent **dirent;
 721	pid_t tgid, ppid;
 722	int rc = 0;
 723	int i, n;
 724
 725	/* special case: only send one comm event using passed in pid */
 726	if (!full) {
 727		tgid = perf_event__synthesize_comm(tool, comm_event, pid,
 728						   process, machine);
 729
 730		if (tgid == -1)
 731			return -1;
 732
 733		if (perf_event__synthesize_namespaces(tool, namespaces_event, pid,
 734						      tgid, process, machine) < 0)
 735			return -1;
 736
 737		/*
 738		 * send mmap only for thread group leader
 739		 * see thread__init_maps()
 740		 */
 741		if (pid == tgid &&
 742		    perf_event__synthesize_mmap_events(tool, mmap_event, pid, tgid,
 743						       process, machine, mmap_data))
 744			return -1;
 745
 746		return 0;
 747	}
 748
 749	if (machine__is_default_guest(machine))
 750		return 0;
 751
 752	snprintf(filename, sizeof(filename), "%s/proc/%d/task",
 753		 machine->root_dir, pid);
 754
 755	n = scandir(filename, &dirent, filter_task, alphasort);
 756	if (n < 0)
 757		return n;
 758
 759	for (i = 0; i < n; i++) {
 760		char *end;
 761		pid_t _pid;
 762		bool kernel_thread = false;
 763
 764		_pid = strtol(dirent[i]->d_name, &end, 10);
 765		if (*end)
 766			continue;
 767
 768		rc = -1;
 769		if (perf_event__prepare_comm(comm_event, pid, _pid, machine,
 770					     &tgid, &ppid, &kernel_thread) != 0)
 771			break;
 772
 773		if (perf_event__synthesize_fork(tool, fork_event, _pid, tgid,
 774						ppid, process, machine) < 0)
 775			break;
 776
 777		if (perf_event__synthesize_namespaces(tool, namespaces_event, _pid,
 778						      tgid, process, machine) < 0)
 779			break;
 780
 781		/*
 782		 * Send the prepared comm event
 783		 */
 784		if (perf_tool__process_synth_event(tool, comm_event, machine, process) != 0)
 785			break;
 786
 787		rc = 0;
 788		if (_pid == pid && !kernel_thread) {
 789			/* process the parent's maps too */
 790			rc = perf_event__synthesize_mmap_events(tool, mmap_event, pid, tgid,
 791						process, machine, mmap_data);
 792			if (rc)
 793				break;
 794		}
 795	}
 796
 797	for (i = 0; i < n; i++)
 798		zfree(&dirent[i]);
 799	free(dirent);
 800
 801	return rc;
 802}
 803
 804int perf_event__synthesize_thread_map(struct perf_tool *tool,
 805				      struct perf_thread_map *threads,
 806				      perf_event__handler_t process,
 807				      struct machine *machine,
 808				      bool mmap_data)
 809{
 810	union perf_event *comm_event, *mmap_event, *fork_event;
 811	union perf_event *namespaces_event;
 812	int err = -1, thread, j;
 813
 814	comm_event = malloc(sizeof(comm_event->comm) + machine->id_hdr_size);
 815	if (comm_event == NULL)
 816		goto out;
 817
 818	mmap_event = malloc(sizeof(mmap_event->mmap2) + machine->id_hdr_size);
 819	if (mmap_event == NULL)
 820		goto out_free_comm;
 821
 822	fork_event = malloc(sizeof(fork_event->fork) + machine->id_hdr_size);
 823	if (fork_event == NULL)
 824		goto out_free_mmap;
 825
 826	namespaces_event = malloc(sizeof(namespaces_event->namespaces) +
 827				  (NR_NAMESPACES * sizeof(struct perf_ns_link_info)) +
 828				  machine->id_hdr_size);
 829	if (namespaces_event == NULL)
 830		goto out_free_fork;
 831
 832	err = 0;
 833	for (thread = 0; thread < threads->nr; ++thread) {
 834		if (__event__synthesize_thread(comm_event, mmap_event,
 835					       fork_event, namespaces_event,
 836					       perf_thread_map__pid(threads, thread), 0,
 837					       process, tool, machine,
 838					       mmap_data)) {
 839			err = -1;
 840			break;
 841		}
 842
 843		/*
 844		 * comm.pid is set to thread group id by
 845		 * perf_event__synthesize_comm
 846		 */
 847		if ((int) comm_event->comm.pid != perf_thread_map__pid(threads, thread)) {
 848			bool need_leader = true;
 849
 850			/* is thread group leader in thread_map? */
 851			for (j = 0; j < threads->nr; ++j) {
 852				if ((int) comm_event->comm.pid == perf_thread_map__pid(threads, j)) {
 853					need_leader = false;
 854					break;
 855				}
 856			}
 857
 858			/* if not, generate events for it */
 859			if (need_leader &&
 860			    __event__synthesize_thread(comm_event, mmap_event,
 861						       fork_event, namespaces_event,
 862						       comm_event->comm.pid, 0,
 863						       process, tool, machine,
 864						       mmap_data)) {
 865				err = -1;
 866				break;
 867			}
 868		}
 869	}
 870	free(namespaces_event);
 871out_free_fork:
 872	free(fork_event);
 873out_free_mmap:
 874	free(mmap_event);
 875out_free_comm:
 876	free(comm_event);
 877out:
 878	return err;
 879}
 880
 881static int __perf_event__synthesize_threads(struct perf_tool *tool,
 882					    perf_event__handler_t process,
 883					    struct machine *machine,
 884					    bool mmap_data,
 885					    struct dirent **dirent,
 886					    int start,
 887					    int num)
 888{
 889	union perf_event *comm_event, *mmap_event, *fork_event;
 890	union perf_event *namespaces_event;
 891	int err = -1;
 892	char *end;
 893	pid_t pid;
 894	int i;
 895
 896	comm_event = malloc(sizeof(comm_event->comm) + machine->id_hdr_size);
 897	if (comm_event == NULL)
 898		goto out;
 899
 900	mmap_event = malloc(sizeof(mmap_event->mmap2) + machine->id_hdr_size);
 901	if (mmap_event == NULL)
 902		goto out_free_comm;
 903
 904	fork_event = malloc(sizeof(fork_event->fork) + machine->id_hdr_size);
 905	if (fork_event == NULL)
 906		goto out_free_mmap;
 907
 908	namespaces_event = malloc(sizeof(namespaces_event->namespaces) +
 909				  (NR_NAMESPACES * sizeof(struct perf_ns_link_info)) +
 910				  machine->id_hdr_size);
 911	if (namespaces_event == NULL)
 912		goto out_free_fork;
 913
 914	for (i = start; i < start + num; i++) {
 915		if (!isdigit(dirent[i]->d_name[0]))
 916			continue;
 917
 918		pid = (pid_t)strtol(dirent[i]->d_name, &end, 10);
 919		/* only interested in proper numerical dirents */
 920		if (*end)
 921			continue;
 922		/*
 923		 * We may race with exiting thread, so don't stop just because
 924		 * one thread couldn't be synthesized.
 925		 */
 926		__event__synthesize_thread(comm_event, mmap_event, fork_event,
 927					   namespaces_event, pid, 1, process,
 928					   tool, machine, mmap_data);
 929	}
 930	err = 0;
 931
 932	free(namespaces_event);
 933out_free_fork:
 934	free(fork_event);
 935out_free_mmap:
 936	free(mmap_event);
 937out_free_comm:
 938	free(comm_event);
 939out:
 940	return err;
 941}
 942
 943struct synthesize_threads_arg {
 944	struct perf_tool *tool;
 945	perf_event__handler_t process;
 946	struct machine *machine;
 947	bool mmap_data;
 948	struct dirent **dirent;
 949	int num;
 950	int start;
 951};
 952
 953static void *synthesize_threads_worker(void *arg)
 954{
 955	struct synthesize_threads_arg *args = arg;
 956
 957	__perf_event__synthesize_threads(args->tool, args->process,
 958					 args->machine, args->mmap_data,
 959					 args->dirent,
 960					 args->start, args->num);
 961	return NULL;
 962}
 963
 964int perf_event__synthesize_threads(struct perf_tool *tool,
 965				   perf_event__handler_t process,
 966				   struct machine *machine,
 967				   bool mmap_data,
 968				   unsigned int nr_threads_synthesize)
 969{
 970	struct synthesize_threads_arg *args = NULL;
 971	pthread_t *synthesize_threads = NULL;
 972	char proc_path[PATH_MAX];
 973	struct dirent **dirent;
 974	int num_per_thread;
 975	int m, n, i, j;
 976	int thread_nr;
 977	int base = 0;
 978	int err = -1;
 979
 980
 981	if (machine__is_default_guest(machine))
 982		return 0;
 983
 984	snprintf(proc_path, sizeof(proc_path), "%s/proc", machine->root_dir);
 985	n = scandir(proc_path, &dirent, filter_task, alphasort);
 986	if (n < 0)
 987		return err;
 988
 989	if (nr_threads_synthesize == UINT_MAX)
 990		thread_nr = sysconf(_SC_NPROCESSORS_ONLN);
 991	else
 992		thread_nr = nr_threads_synthesize;
 993
 994	if (thread_nr <= 1) {
 995		err = __perf_event__synthesize_threads(tool, process,
 996						       machine, mmap_data,
 997						       dirent, base, n);
 998		goto free_dirent;
 999	}
1000	if (thread_nr > n)
1001		thread_nr = n;
1002
1003	synthesize_threads = calloc(sizeof(pthread_t), thread_nr);
1004	if (synthesize_threads == NULL)
1005		goto free_dirent;
1006
1007	args = calloc(sizeof(*args), thread_nr);
1008	if (args == NULL)
1009		goto free_threads;
1010
1011	num_per_thread = n / thread_nr;
1012	m = n % thread_nr;
1013	for (i = 0; i < thread_nr; i++) {
1014		args[i].tool = tool;
1015		args[i].process = process;
1016		args[i].machine = machine;
1017		args[i].mmap_data = mmap_data;
1018		args[i].dirent = dirent;
1019	}
1020	for (i = 0; i < m; i++) {
1021		args[i].num = num_per_thread + 1;
1022		args[i].start = i * args[i].num;
1023	}
1024	if (i != 0)
1025		base = args[i-1].start + args[i-1].num;
1026	for (j = i; j < thread_nr; j++) {
1027		args[j].num = num_per_thread;
1028		args[j].start = base + (j - i) * args[i].num;
1029	}
1030
1031	for (i = 0; i < thread_nr; i++) {
1032		if (pthread_create(&synthesize_threads[i], NULL,
1033				   synthesize_threads_worker, &args[i]))
1034			goto out_join;
1035	}
1036	err = 0;
1037out_join:
1038	for (i = 0; i < thread_nr; i++)
1039		pthread_join(synthesize_threads[i], NULL);
1040	free(args);
1041free_threads:
1042	free(synthesize_threads);
1043free_dirent:
1044	for (i = 0; i < n; i++)
1045		zfree(&dirent[i]);
1046	free(dirent);
1047
1048	return err;
1049}
1050
1051int __weak perf_event__synthesize_extra_kmaps(struct perf_tool *tool __maybe_unused,
1052					      perf_event__handler_t process __maybe_unused,
1053					      struct machine *machine __maybe_unused)
1054{
1055	return 0;
1056}
1057
1058static int __perf_event__synthesize_kernel_mmap(struct perf_tool *tool,
1059						perf_event__handler_t process,
1060						struct machine *machine)
1061{
1062	union perf_event *event;
1063	size_t size = symbol_conf.buildid_mmap2 ?
1064			sizeof(event->mmap2) : sizeof(event->mmap);
1065	struct map *map = machine__kernel_map(machine);
1066	struct kmap *kmap;
1067	int err;
1068
1069	if (map == NULL)
1070		return -1;
1071
1072	kmap = map__kmap(map);
1073	if (!kmap->ref_reloc_sym)
1074		return -1;
1075
1076	/*
1077	 * We should get this from /sys/kernel/sections/.text, but till that is
1078	 * available use this, and after it is use this as a fallback for older
1079	 * kernels.
1080	 */
1081	event = zalloc(size + machine->id_hdr_size);
1082	if (event == NULL) {
1083		pr_debug("Not enough memory synthesizing mmap event "
1084			 "for kernel modules\n");
1085		return -1;
1086	}
1087
1088	if (machine__is_host(machine)) {
1089		/*
1090		 * kernel uses PERF_RECORD_MISC_USER for user space maps,
1091		 * see kernel/perf_event.c __perf_event_mmap
1092		 */
1093		event->header.misc = PERF_RECORD_MISC_KERNEL;
1094	} else {
1095		event->header.misc = PERF_RECORD_MISC_GUEST_KERNEL;
1096	}
1097
1098	if (symbol_conf.buildid_mmap2) {
1099		size = snprintf(event->mmap2.filename, sizeof(event->mmap2.filename),
1100				"%s%s", machine->mmap_name, kmap->ref_reloc_sym->name) + 1;
1101		size = PERF_ALIGN(size, sizeof(u64));
1102		event->mmap2.header.type = PERF_RECORD_MMAP2;
1103		event->mmap2.header.size = (sizeof(event->mmap2) -
1104				(sizeof(event->mmap2.filename) - size) + machine->id_hdr_size);
1105		event->mmap2.pgoff = kmap->ref_reloc_sym->addr;
1106		event->mmap2.start = map->start;
1107		event->mmap2.len   = map->end - event->mmap.start;
1108		event->mmap2.pid   = machine->pid;
1109
1110		perf_record_mmap2__read_build_id(&event->mmap2, true);
1111	} else {
1112		size = snprintf(event->mmap.filename, sizeof(event->mmap.filename),
1113				"%s%s", machine->mmap_name, kmap->ref_reloc_sym->name) + 1;
1114		size = PERF_ALIGN(size, sizeof(u64));
1115		event->mmap.header.type = PERF_RECORD_MMAP;
1116		event->mmap.header.size = (sizeof(event->mmap) -
1117				(sizeof(event->mmap.filename) - size) + machine->id_hdr_size);
1118		event->mmap.pgoff = kmap->ref_reloc_sym->addr;
1119		event->mmap.start = map->start;
1120		event->mmap.len   = map->end - event->mmap.start;
1121		event->mmap.pid   = machine->pid;
1122	}
1123
1124	err = perf_tool__process_synth_event(tool, event, machine, process);
1125	free(event);
1126
1127	return err;
1128}
1129
1130int perf_event__synthesize_kernel_mmap(struct perf_tool *tool,
1131				       perf_event__handler_t process,
1132				       struct machine *machine)
1133{
1134	int err;
1135
1136	err = __perf_event__synthesize_kernel_mmap(tool, process, machine);
1137	if (err < 0)
1138		return err;
1139
1140	return perf_event__synthesize_extra_kmaps(tool, process, machine);
1141}
1142
1143int perf_event__synthesize_thread_map2(struct perf_tool *tool,
1144				      struct perf_thread_map *threads,
1145				      perf_event__handler_t process,
1146				      struct machine *machine)
1147{
1148	union perf_event *event;
1149	int i, err, size;
1150
1151	size  = sizeof(event->thread_map);
1152	size +=	threads->nr * sizeof(event->thread_map.entries[0]);
1153
1154	event = zalloc(size);
1155	if (!event)
1156		return -ENOMEM;
1157
1158	event->header.type = PERF_RECORD_THREAD_MAP;
1159	event->header.size = size;
1160	event->thread_map.nr = threads->nr;
1161
1162	for (i = 0; i < threads->nr; i++) {
1163		struct perf_record_thread_map_entry *entry = &event->thread_map.entries[i];
1164		char *comm = perf_thread_map__comm(threads, i);
1165
1166		if (!comm)
1167			comm = (char *) "";
1168
1169		entry->pid = perf_thread_map__pid(threads, i);
1170		strncpy((char *) &entry->comm, comm, sizeof(entry->comm));
1171	}
1172
1173	err = process(tool, event, NULL, machine);
1174
1175	free(event);
1176	return err;
1177}
1178
1179static void synthesize_cpus(struct cpu_map_entries *cpus,
1180			    struct perf_cpu_map *map)
1181{
1182	int i;
1183
1184	cpus->nr = map->nr;
1185
1186	for (i = 0; i < map->nr; i++)
1187		cpus->cpu[i] = map->map[i];
1188}
1189
1190static void synthesize_mask(struct perf_record_record_cpu_map *mask,
1191			    struct perf_cpu_map *map, int max)
1192{
1193	int i;
1194
1195	mask->nr = BITS_TO_LONGS(max);
1196	mask->long_size = sizeof(long);
1197
1198	for (i = 0; i < map->nr; i++)
1199		set_bit(map->map[i], mask->mask);
1200}
1201
1202static size_t cpus_size(struct perf_cpu_map *map)
1203{
1204	return sizeof(struct cpu_map_entries) + map->nr * sizeof(u16);
1205}
1206
1207static size_t mask_size(struct perf_cpu_map *map, int *max)
1208{
1209	int i;
1210
1211	*max = 0;
1212
1213	for (i = 0; i < map->nr; i++) {
1214		/* bit position of the cpu is + 1 */
1215		int bit = map->map[i] + 1;
1216
1217		if (bit > *max)
1218			*max = bit;
1219	}
1220
1221	return sizeof(struct perf_record_record_cpu_map) + BITS_TO_LONGS(*max) * sizeof(long);
1222}
1223
1224void *cpu_map_data__alloc(struct perf_cpu_map *map, size_t *size, u16 *type, int *max)
1225{
1226	size_t size_cpus, size_mask;
1227	bool is_dummy = perf_cpu_map__empty(map);
1228
1229	/*
1230	 * Both array and mask data have variable size based
1231	 * on the number of cpus and their actual values.
1232	 * The size of the 'struct perf_record_cpu_map_data' is:
1233	 *
1234	 *   array = size of 'struct cpu_map_entries' +
1235	 *           number of cpus * sizeof(u64)
1236	 *
1237	 *   mask  = size of 'struct perf_record_record_cpu_map' +
1238	 *           maximum cpu bit converted to size of longs
1239	 *
1240	 * and finally + the size of 'struct perf_record_cpu_map_data'.
1241	 */
1242	size_cpus = cpus_size(map);
1243	size_mask = mask_size(map, max);
1244
1245	if (is_dummy || (size_cpus < size_mask)) {
1246		*size += size_cpus;
1247		*type  = PERF_CPU_MAP__CPUS;
1248	} else {
1249		*size += size_mask;
1250		*type  = PERF_CPU_MAP__MASK;
1251	}
1252
1253	*size += sizeof(struct perf_record_cpu_map_data);
1254	*size = PERF_ALIGN(*size, sizeof(u64));
1255	return zalloc(*size);
1256}
1257
1258void cpu_map_data__synthesize(struct perf_record_cpu_map_data *data, struct perf_cpu_map *map,
1259			      u16 type, int max)
1260{
1261	data->type = type;
1262
1263	switch (type) {
1264	case PERF_CPU_MAP__CPUS:
1265		synthesize_cpus((struct cpu_map_entries *) data->data, map);
1266		break;
1267	case PERF_CPU_MAP__MASK:
1268		synthesize_mask((struct perf_record_record_cpu_map *)data->data, map, max);
1269	default:
1270		break;
1271	}
1272}
1273
1274static struct perf_record_cpu_map *cpu_map_event__new(struct perf_cpu_map *map)
1275{
1276	size_t size = sizeof(struct perf_record_cpu_map);
1277	struct perf_record_cpu_map *event;
1278	int max;
1279	u16 type;
1280
1281	event = cpu_map_data__alloc(map, &size, &type, &max);
1282	if (!event)
1283		return NULL;
1284
1285	event->header.type = PERF_RECORD_CPU_MAP;
1286	event->header.size = size;
1287	event->data.type   = type;
1288
1289	cpu_map_data__synthesize(&event->data, map, type, max);
1290	return event;
1291}
1292
1293int perf_event__synthesize_cpu_map(struct perf_tool *tool,
1294				   struct perf_cpu_map *map,
1295				   perf_event__handler_t process,
1296				   struct machine *machine)
1297{
1298	struct perf_record_cpu_map *event;
1299	int err;
1300
1301	event = cpu_map_event__new(map);
1302	if (!event)
1303		return -ENOMEM;
1304
1305	err = process(tool, (union perf_event *) event, NULL, machine);
1306
1307	free(event);
1308	return err;
1309}
1310
1311int perf_event__synthesize_stat_config(struct perf_tool *tool,
1312				       struct perf_stat_config *config,
1313				       perf_event__handler_t process,
1314				       struct machine *machine)
1315{
1316	struct perf_record_stat_config *event;
1317	int size, i = 0, err;
1318
1319	size  = sizeof(*event);
1320	size += (PERF_STAT_CONFIG_TERM__MAX * sizeof(event->data[0]));
1321
1322	event = zalloc(size);
1323	if (!event)
1324		return -ENOMEM;
1325
1326	event->header.type = PERF_RECORD_STAT_CONFIG;
1327	event->header.size = size;
1328	event->nr          = PERF_STAT_CONFIG_TERM__MAX;
1329
1330#define ADD(__term, __val)					\
1331	event->data[i].tag = PERF_STAT_CONFIG_TERM__##__term;	\
1332	event->data[i].val = __val;				\
1333	i++;
1334
1335	ADD(AGGR_MODE,	config->aggr_mode)
1336	ADD(INTERVAL,	config->interval)
1337	ADD(SCALE,	config->scale)
1338
1339	WARN_ONCE(i != PERF_STAT_CONFIG_TERM__MAX,
1340		  "stat config terms unbalanced\n");
1341#undef ADD
1342
1343	err = process(tool, (union perf_event *) event, NULL, machine);
1344
1345	free(event);
1346	return err;
1347}
1348
1349int perf_event__synthesize_stat(struct perf_tool *tool,
1350				u32 cpu, u32 thread, u64 id,
1351				struct perf_counts_values *count,
1352				perf_event__handler_t process,
1353				struct machine *machine)
1354{
1355	struct perf_record_stat event;
1356
1357	event.header.type = PERF_RECORD_STAT;
1358	event.header.size = sizeof(event);
1359	event.header.misc = 0;
1360
1361	event.id        = id;
1362	event.cpu       = cpu;
1363	event.thread    = thread;
1364	event.val       = count->val;
1365	event.ena       = count->ena;
1366	event.run       = count->run;
1367
1368	return process(tool, (union perf_event *) &event, NULL, machine);
1369}
1370
1371int perf_event__synthesize_stat_round(struct perf_tool *tool,
1372				      u64 evtime, u64 type,
1373				      perf_event__handler_t process,
1374				      struct machine *machine)
1375{
1376	struct perf_record_stat_round event;
1377
1378	event.header.type = PERF_RECORD_STAT_ROUND;
1379	event.header.size = sizeof(event);
1380	event.header.misc = 0;
1381
1382	event.time = evtime;
1383	event.type = type;
1384
1385	return process(tool, (union perf_event *) &event, NULL, machine);
1386}
1387
1388size_t perf_event__sample_event_size(const struct perf_sample *sample, u64 type, u64 read_format)
1389{
1390	size_t sz, result = sizeof(struct perf_record_sample);
1391
1392	if (type & PERF_SAMPLE_IDENTIFIER)
1393		result += sizeof(u64);
1394
1395	if (type & PERF_SAMPLE_IP)
1396		result += sizeof(u64);
1397
1398	if (type & PERF_SAMPLE_TID)
1399		result += sizeof(u64);
1400
1401	if (type & PERF_SAMPLE_TIME)
1402		result += sizeof(u64);
1403
1404	if (type & PERF_SAMPLE_ADDR)
1405		result += sizeof(u64);
1406
1407	if (type & PERF_SAMPLE_ID)
1408		result += sizeof(u64);
1409
1410	if (type & PERF_SAMPLE_STREAM_ID)
1411		result += sizeof(u64);
1412
1413	if (type & PERF_SAMPLE_CPU)
1414		result += sizeof(u64);
1415
1416	if (type & PERF_SAMPLE_PERIOD)
1417		result += sizeof(u64);
1418
1419	if (type & PERF_SAMPLE_READ) {
1420		result += sizeof(u64);
1421		if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
1422			result += sizeof(u64);
1423		if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
1424			result += sizeof(u64);
1425		/* PERF_FORMAT_ID is forced for PERF_SAMPLE_READ */
1426		if (read_format & PERF_FORMAT_GROUP) {
1427			sz = sample->read.group.nr *
1428			     sizeof(struct sample_read_value);
1429			result += sz;
1430		} else {
1431			result += sizeof(u64);
1432		}
1433	}
1434
1435	if (type & PERF_SAMPLE_CALLCHAIN) {
1436		sz = (sample->callchain->nr + 1) * sizeof(u64);
1437		result += sz;
1438	}
1439
1440	if (type & PERF_SAMPLE_RAW) {
1441		result += sizeof(u32);
1442		result += sample->raw_size;
1443	}
1444
1445	if (type & PERF_SAMPLE_BRANCH_STACK) {
1446		sz = sample->branch_stack->nr * sizeof(struct branch_entry);
1447		/* nr, hw_idx */
1448		sz += 2 * sizeof(u64);
1449		result += sz;
1450	}
1451
1452	if (type & PERF_SAMPLE_REGS_USER) {
1453		if (sample->user_regs.abi) {
1454			result += sizeof(u64);
1455			sz = hweight64(sample->user_regs.mask) * sizeof(u64);
1456			result += sz;
1457		} else {
1458			result += sizeof(u64);
1459		}
1460	}
1461
1462	if (type & PERF_SAMPLE_STACK_USER) {
1463		sz = sample->user_stack.size;
1464		result += sizeof(u64);
1465		if (sz) {
1466			result += sz;
1467			result += sizeof(u64);
1468		}
1469	}
1470
1471	if (type & PERF_SAMPLE_WEIGHT_TYPE)
1472		result += sizeof(u64);
1473
1474	if (type & PERF_SAMPLE_DATA_SRC)
1475		result += sizeof(u64);
1476
1477	if (type & PERF_SAMPLE_TRANSACTION)
1478		result += sizeof(u64);
1479
1480	if (type & PERF_SAMPLE_REGS_INTR) {
1481		if (sample->intr_regs.abi) {
1482			result += sizeof(u64);
1483			sz = hweight64(sample->intr_regs.mask) * sizeof(u64);
1484			result += sz;
1485		} else {
1486			result += sizeof(u64);
1487		}
1488	}
1489
1490	if (type & PERF_SAMPLE_PHYS_ADDR)
1491		result += sizeof(u64);
1492
1493	if (type & PERF_SAMPLE_CGROUP)
1494		result += sizeof(u64);
1495
1496	if (type & PERF_SAMPLE_DATA_PAGE_SIZE)
1497		result += sizeof(u64);
1498
1499	if (type & PERF_SAMPLE_CODE_PAGE_SIZE)
1500		result += sizeof(u64);
1501
1502	if (type & PERF_SAMPLE_AUX) {
1503		result += sizeof(u64);
1504		result += sample->aux_sample.size;
1505	}
1506
1507	return result;
1508}
1509
1510void __weak arch_perf_synthesize_sample_weight(const struct perf_sample *data,
1511					       __u64 *array, u64 type __maybe_unused)
1512{
1513	*array = data->weight;
1514}
1515
1516int perf_event__synthesize_sample(union perf_event *event, u64 type, u64 read_format,
1517				  const struct perf_sample *sample)
1518{
1519	__u64 *array;
1520	size_t sz;
1521	/*
1522	 * used for cross-endian analysis. See git commit 65014ab3
1523	 * for why this goofiness is needed.
1524	 */
1525	union u64_swap u;
1526
1527	array = event->sample.array;
1528
1529	if (type & PERF_SAMPLE_IDENTIFIER) {
1530		*array = sample->id;
1531		array++;
1532	}
1533
1534	if (type & PERF_SAMPLE_IP) {
1535		*array = sample->ip;
1536		array++;
1537	}
1538
1539	if (type & PERF_SAMPLE_TID) {
1540		u.val32[0] = sample->pid;
1541		u.val32[1] = sample->tid;
1542		*array = u.val64;
1543		array++;
1544	}
1545
1546	if (type & PERF_SAMPLE_TIME) {
1547		*array = sample->time;
1548		array++;
1549	}
1550
1551	if (type & PERF_SAMPLE_ADDR) {
1552		*array = sample->addr;
1553		array++;
1554	}
1555
1556	if (type & PERF_SAMPLE_ID) {
1557		*array = sample->id;
1558		array++;
1559	}
1560
1561	if (type & PERF_SAMPLE_STREAM_ID) {
1562		*array = sample->stream_id;
1563		array++;
1564	}
1565
1566	if (type & PERF_SAMPLE_CPU) {
1567		u.val32[0] = sample->cpu;
1568		u.val32[1] = 0;
1569		*array = u.val64;
1570		array++;
1571	}
1572
1573	if (type & PERF_SAMPLE_PERIOD) {
1574		*array = sample->period;
1575		array++;
1576	}
1577
1578	if (type & PERF_SAMPLE_READ) {
1579		if (read_format & PERF_FORMAT_GROUP)
1580			*array = sample->read.group.nr;
1581		else
1582			*array = sample->read.one.value;
1583		array++;
1584
1585		if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) {
1586			*array = sample->read.time_enabled;
1587			array++;
1588		}
1589
1590		if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) {
1591			*array = sample->read.time_running;
1592			array++;
1593		}
1594
1595		/* PERF_FORMAT_ID is forced for PERF_SAMPLE_READ */
1596		if (read_format & PERF_FORMAT_GROUP) {
1597			sz = sample->read.group.nr *
1598			     sizeof(struct sample_read_value);
1599			memcpy(array, sample->read.group.values, sz);
1600			array = (void *)array + sz;
1601		} else {
1602			*array = sample->read.one.id;
1603			array++;
1604		}
1605	}
1606
1607	if (type & PERF_SAMPLE_CALLCHAIN) {
1608		sz = (sample->callchain->nr + 1) * sizeof(u64);
1609		memcpy(array, sample->callchain, sz);
1610		array = (void *)array + sz;
1611	}
1612
1613	if (type & PERF_SAMPLE_RAW) {
1614		u.val32[0] = sample->raw_size;
1615		*array = u.val64;
1616		array = (void *)array + sizeof(u32);
1617
1618		memcpy(array, sample->raw_data, sample->raw_size);
1619		array = (void *)array + sample->raw_size;
1620	}
1621
1622	if (type & PERF_SAMPLE_BRANCH_STACK) {
1623		sz = sample->branch_stack->nr * sizeof(struct branch_entry);
1624		/* nr, hw_idx */
1625		sz += 2 * sizeof(u64);
1626		memcpy(array, sample->branch_stack, sz);
1627		array = (void *)array + sz;
1628	}
1629
1630	if (type & PERF_SAMPLE_REGS_USER) {
1631		if (sample->user_regs.abi) {
1632			*array++ = sample->user_regs.abi;
1633			sz = hweight64(sample->user_regs.mask) * sizeof(u64);
1634			memcpy(array, sample->user_regs.regs, sz);
1635			array = (void *)array + sz;
1636		} else {
1637			*array++ = 0;
1638		}
1639	}
1640
1641	if (type & PERF_SAMPLE_STACK_USER) {
1642		sz = sample->user_stack.size;
1643		*array++ = sz;
1644		if (sz) {
1645			memcpy(array, sample->user_stack.data, sz);
1646			array = (void *)array + sz;
1647			*array++ = sz;
1648		}
1649	}
1650
1651	if (type & PERF_SAMPLE_WEIGHT_TYPE) {
1652		arch_perf_synthesize_sample_weight(sample, array, type);
1653		array++;
1654	}
1655
1656	if (type & PERF_SAMPLE_DATA_SRC) {
1657		*array = sample->data_src;
1658		array++;
1659	}
1660
1661	if (type & PERF_SAMPLE_TRANSACTION) {
1662		*array = sample->transaction;
1663		array++;
1664	}
1665
1666	if (type & PERF_SAMPLE_REGS_INTR) {
1667		if (sample->intr_regs.abi) {
1668			*array++ = sample->intr_regs.abi;
1669			sz = hweight64(sample->intr_regs.mask) * sizeof(u64);
1670			memcpy(array, sample->intr_regs.regs, sz);
1671			array = (void *)array + sz;
1672		} else {
1673			*array++ = 0;
1674		}
1675	}
1676
1677	if (type & PERF_SAMPLE_PHYS_ADDR) {
1678		*array = sample->phys_addr;
1679		array++;
1680	}
1681
1682	if (type & PERF_SAMPLE_CGROUP) {
1683		*array = sample->cgroup;
1684		array++;
1685	}
1686
1687	if (type & PERF_SAMPLE_DATA_PAGE_SIZE) {
1688		*array = sample->data_page_size;
1689		array++;
1690	}
1691
1692	if (type & PERF_SAMPLE_CODE_PAGE_SIZE) {
1693		*array = sample->code_page_size;
1694		array++;
1695	}
1696
1697	if (type & PERF_SAMPLE_AUX) {
1698		sz = sample->aux_sample.size;
1699		*array++ = sz;
1700		memcpy(array, sample->aux_sample.data, sz);
1701		array = (void *)array + sz;
1702	}
1703
1704	return 0;
1705}
1706
1707int perf_event__synthesize_id_index(struct perf_tool *tool, perf_event__handler_t process,
1708				    struct evlist *evlist, struct machine *machine)
1709{
1710	union perf_event *ev;
1711	struct evsel *evsel;
1712	size_t nr = 0, i = 0, sz, max_nr, n;
1713	int err;
1714
1715	pr_debug2("Synthesizing id index\n");
1716
1717	max_nr = (UINT16_MAX - sizeof(struct perf_record_id_index)) /
1718		 sizeof(struct id_index_entry);
1719
1720	evlist__for_each_entry(evlist, evsel)
1721		nr += evsel->core.ids;
1722
1723	n = nr > max_nr ? max_nr : nr;
1724	sz = sizeof(struct perf_record_id_index) + n * sizeof(struct id_index_entry);
1725	ev = zalloc(sz);
1726	if (!ev)
1727		return -ENOMEM;
1728
1729	ev->id_index.header.type = PERF_RECORD_ID_INDEX;
1730	ev->id_index.header.size = sz;
1731	ev->id_index.nr = n;
1732
1733	evlist__for_each_entry(evlist, evsel) {
1734		u32 j;
1735
1736		for (j = 0; j < evsel->core.ids; j++) {
1737			struct id_index_entry *e;
1738			struct perf_sample_id *sid;
1739
1740			if (i >= n) {
1741				err = process(tool, ev, NULL, machine);
1742				if (err)
1743					goto out_err;
1744				nr -= n;
1745				i = 0;
1746			}
1747
1748			e = &ev->id_index.entries[i++];
1749
1750			e->id = evsel->core.id[j];
1751
1752			sid = evlist__id2sid(evlist, e->id);
1753			if (!sid) {
1754				free(ev);
1755				return -ENOENT;
1756			}
1757
1758			e->idx = sid->idx;
1759			e->cpu = sid->cpu;
1760			e->tid = sid->tid;
1761		}
1762	}
1763
1764	sz = sizeof(struct perf_record_id_index) + nr * sizeof(struct id_index_entry);
1765	ev->id_index.header.size = sz;
1766	ev->id_index.nr = nr;
1767
1768	err = process(tool, ev, NULL, machine);
1769out_err:
1770	free(ev);
1771
1772	return err;
1773}
1774
1775int __machine__synthesize_threads(struct machine *machine, struct perf_tool *tool,
1776				  struct target *target, struct perf_thread_map *threads,
1777				  perf_event__handler_t process, bool data_mmap,
1778				  unsigned int nr_threads_synthesize)
1779{
1780	if (target__has_task(target))
1781		return perf_event__synthesize_thread_map(tool, threads, process, machine, data_mmap);
1782	else if (target__has_cpu(target))
1783		return perf_event__synthesize_threads(tool, process,
1784						      machine, data_mmap,
1785						      nr_threads_synthesize);
1786	/* command specified */
1787	return 0;
1788}
1789
1790int machine__synthesize_threads(struct machine *machine, struct target *target,
1791				struct perf_thread_map *threads, bool data_mmap,
1792				unsigned int nr_threads_synthesize)
1793{
1794	return __machine__synthesize_threads(machine, NULL, target, threads,
1795					     perf_event__process, data_mmap,
1796					     nr_threads_synthesize);
1797}
1798
1799static struct perf_record_event_update *event_update_event__new(size_t size, u64 type, u64 id)
1800{
1801	struct perf_record_event_update *ev;
1802
1803	size += sizeof(*ev);
1804	size  = PERF_ALIGN(size, sizeof(u64));
1805
1806	ev = zalloc(size);
1807	if (ev) {
1808		ev->header.type = PERF_RECORD_EVENT_UPDATE;
1809		ev->header.size = (u16)size;
1810		ev->type	= type;
1811		ev->id		= id;
1812	}
1813	return ev;
1814}
1815
1816int perf_event__synthesize_event_update_unit(struct perf_tool *tool, struct evsel *evsel,
1817					     perf_event__handler_t process)
1818{
1819	size_t size = strlen(evsel->unit);
1820	struct perf_record_event_update *ev;
1821	int err;
1822
1823	ev = event_update_event__new(size + 1, PERF_EVENT_UPDATE__UNIT, evsel->core.id[0]);
1824	if (ev == NULL)
1825		return -ENOMEM;
1826
1827	strlcpy(ev->data, evsel->unit, size + 1);
1828	err = process(tool, (union perf_event *)ev, NULL, NULL);
1829	free(ev);
1830	return err;
1831}
1832
1833int perf_event__synthesize_event_update_scale(struct perf_tool *tool, struct evsel *evsel,
1834					      perf_event__handler_t process)
1835{
1836	struct perf_record_event_update *ev;
1837	struct perf_record_event_update_scale *ev_data;
1838	int err;
1839
1840	ev = event_update_event__new(sizeof(*ev_data), PERF_EVENT_UPDATE__SCALE, evsel->core.id[0]);
1841	if (ev == NULL)
1842		return -ENOMEM;
1843
1844	ev_data = (struct perf_record_event_update_scale *)ev->data;
1845	ev_data->scale = evsel->scale;
1846	err = process(tool, (union perf_event *)ev, NULL, NULL);
1847	free(ev);
1848	return err;
1849}
1850
1851int perf_event__synthesize_event_update_name(struct perf_tool *tool, struct evsel *evsel,
1852					     perf_event__handler_t process)
1853{
1854	struct perf_record_event_update *ev;
1855	size_t len = strlen(evsel->name);
1856	int err;
1857
1858	ev = event_update_event__new(len + 1, PERF_EVENT_UPDATE__NAME, evsel->core.id[0]);
1859	if (ev == NULL)
1860		return -ENOMEM;
1861
1862	strlcpy(ev->data, evsel->name, len + 1);
1863	err = process(tool, (union perf_event *)ev, NULL, NULL);
1864	free(ev);
1865	return err;
1866}
1867
1868int perf_event__synthesize_event_update_cpus(struct perf_tool *tool, struct evsel *evsel,
1869					     perf_event__handler_t process)
1870{
1871	size_t size = sizeof(struct perf_record_event_update);
1872	struct perf_record_event_update *ev;
1873	int max, err;
1874	u16 type;
1875
1876	if (!evsel->core.own_cpus)
1877		return 0;
1878
1879	ev = cpu_map_data__alloc(evsel->core.own_cpus, &size, &type, &max);
1880	if (!ev)
1881		return -ENOMEM;
1882
1883	ev->header.type = PERF_RECORD_EVENT_UPDATE;
1884	ev->header.size = (u16)size;
1885	ev->type	= PERF_EVENT_UPDATE__CPUS;
1886	ev->id		= evsel->core.id[0];
1887
1888	cpu_map_data__synthesize((struct perf_record_cpu_map_data *)ev->data,
1889				 evsel->core.own_cpus, type, max);
1890
1891	err = process(tool, (union perf_event *)ev, NULL, NULL);
1892	free(ev);
1893	return err;
1894}
1895
1896int perf_event__synthesize_attrs(struct perf_tool *tool, struct evlist *evlist,
1897				 perf_event__handler_t process)
1898{
1899	struct evsel *evsel;
1900	int err = 0;
1901
1902	evlist__for_each_entry(evlist, evsel) {
1903		err = perf_event__synthesize_attr(tool, &evsel->core.attr, evsel->core.ids,
1904						  evsel->core.id, process);
1905		if (err) {
1906			pr_debug("failed to create perf header attribute\n");
1907			return err;
1908		}
1909	}
1910
1911	return err;
1912}
1913
1914static bool has_unit(struct evsel *evsel)
1915{
1916	return evsel->unit && *evsel->unit;
1917}
1918
1919static bool has_scale(struct evsel *evsel)
1920{
1921	return evsel->scale != 1;
1922}
1923
1924int perf_event__synthesize_extra_attr(struct perf_tool *tool, struct evlist *evsel_list,
1925				      perf_event__handler_t process, bool is_pipe)
1926{
1927	struct evsel *evsel;
1928	int err;
1929
1930	/*
1931	 * Synthesize other events stuff not carried within
1932	 * attr event - unit, scale, name
1933	 */
1934	evlist__for_each_entry(evsel_list, evsel) {
1935		if (!evsel->supported)
1936			continue;
1937
1938		/*
1939		 * Synthesize unit and scale only if it's defined.
1940		 */
1941		if (has_unit(evsel)) {
1942			err = perf_event__synthesize_event_update_unit(tool, evsel, process);
1943			if (err < 0) {
1944				pr_err("Couldn't synthesize evsel unit.\n");
1945				return err;
1946			}
1947		}
1948
1949		if (has_scale(evsel)) {
1950			err = perf_event__synthesize_event_update_scale(tool, evsel, process);
1951			if (err < 0) {
1952				pr_err("Couldn't synthesize evsel evsel.\n");
1953				return err;
1954			}
1955		}
1956
1957		if (evsel->core.own_cpus) {
1958			err = perf_event__synthesize_event_update_cpus(tool, evsel, process);
1959			if (err < 0) {
1960				pr_err("Couldn't synthesize evsel cpus.\n");
1961				return err;
1962			}
1963		}
1964
1965		/*
1966		 * Name is needed only for pipe output,
1967		 * perf.data carries event names.
1968		 */
1969		if (is_pipe) {
1970			err = perf_event__synthesize_event_update_name(tool, evsel, process);
1971			if (err < 0) {
1972				pr_err("Couldn't synthesize evsel name.\n");
1973				return err;
1974			}
1975		}
1976	}
1977	return 0;
1978}
1979
1980int perf_event__synthesize_attr(struct perf_tool *tool, struct perf_event_attr *attr,
1981				u32 ids, u64 *id, perf_event__handler_t process)
1982{
1983	union perf_event *ev;
1984	size_t size;
1985	int err;
1986
1987	size = sizeof(struct perf_event_attr);
1988	size = PERF_ALIGN(size, sizeof(u64));
1989	size += sizeof(struct perf_event_header);
1990	size += ids * sizeof(u64);
1991
1992	ev = zalloc(size);
1993
1994	if (ev == NULL)
1995		return -ENOMEM;
1996
1997	ev->attr.attr = *attr;
1998	memcpy(ev->attr.id, id, ids * sizeof(u64));
1999
2000	ev->attr.header.type = PERF_RECORD_HEADER_ATTR;
2001	ev->attr.header.size = (u16)size;
2002
2003	if (ev->attr.header.size == size)
2004		err = process(tool, ev, NULL, NULL);
2005	else
2006		err = -E2BIG;
2007
2008	free(ev);
2009
2010	return err;
2011}
2012
2013int perf_event__synthesize_tracing_data(struct perf_tool *tool, int fd, struct evlist *evlist,
2014					perf_event__handler_t process)
2015{
2016	union perf_event ev;
2017	struct tracing_data *tdata;
2018	ssize_t size = 0, aligned_size = 0, padding;
2019	struct feat_fd ff;
2020
2021	/*
2022	 * We are going to store the size of the data followed
2023	 * by the data contents. Since the fd descriptor is a pipe,
2024	 * we cannot seek back to store the size of the data once
2025	 * we know it. Instead we:
2026	 *
2027	 * - write the tracing data to the temp file
2028	 * - get/write the data size to pipe
2029	 * - write the tracing data from the temp file
2030	 *   to the pipe
2031	 */
2032	tdata = tracing_data_get(&evlist->core.entries, fd, true);
2033	if (!tdata)
2034		return -1;
2035
2036	memset(&ev, 0, sizeof(ev));
2037
2038	ev.tracing_data.header.type = PERF_RECORD_HEADER_TRACING_DATA;
2039	size = tdata->size;
2040	aligned_size = PERF_ALIGN(size, sizeof(u64));
2041	padding = aligned_size - size;
2042	ev.tracing_data.header.size = sizeof(ev.tracing_data);
2043	ev.tracing_data.size = aligned_size;
2044
2045	process(tool, &ev, NULL, NULL);
2046
2047	/*
2048	 * The put function will copy all the tracing data
2049	 * stored in temp file to the pipe.
2050	 */
2051	tracing_data_put(tdata);
2052
2053	ff = (struct feat_fd){ .fd = fd };
2054	if (write_padded(&ff, NULL, 0, padding))
2055		return -1;
2056
2057	return aligned_size;
2058}
2059
2060int perf_event__synthesize_build_id(struct perf_tool *tool, struct dso *pos, u16 misc,
2061				    perf_event__handler_t process, struct machine *machine)
2062{
2063	union perf_event ev;
2064	size_t len;
2065
2066	if (!pos->hit)
2067		return 0;
2068
2069	memset(&ev, 0, sizeof(ev));
2070
2071	len = pos->long_name_len + 1;
2072	len = PERF_ALIGN(len, NAME_ALIGN);
2073	memcpy(&ev.build_id.build_id, pos->bid.data, sizeof(pos->bid.data));
2074	ev.build_id.header.type = PERF_RECORD_HEADER_BUILD_ID;
2075	ev.build_id.header.misc = misc;
2076	ev.build_id.pid = machine->pid;
2077	ev.build_id.header.size = sizeof(ev.build_id) + len;
2078	memcpy(&ev.build_id.filename, pos->long_name, pos->long_name_len);
2079
2080	return process(tool, &ev, NULL, machine);
2081}
2082
2083int perf_event__synthesize_stat_events(struct perf_stat_config *config, struct perf_tool *tool,
2084				       struct evlist *evlist, perf_event__handler_t process, bool attrs)
2085{
2086	int err;
2087
2088	if (attrs) {
2089		err = perf_event__synthesize_attrs(tool, evlist, process);
2090		if (err < 0) {
2091			pr_err("Couldn't synthesize attrs.\n");
2092			return err;
2093		}
2094	}
2095
2096	err = perf_event__synthesize_extra_attr(tool, evlist, process, attrs);
2097	err = perf_event__synthesize_thread_map2(tool, evlist->core.threads, process, NULL);
2098	if (err < 0) {
2099		pr_err("Couldn't synthesize thread map.\n");
2100		return err;
2101	}
2102
2103	err = perf_event__synthesize_cpu_map(tool, evlist->core.cpus, process, NULL);
2104	if (err < 0) {
2105		pr_err("Couldn't synthesize thread map.\n");
2106		return err;
2107	}
2108
2109	err = perf_event__synthesize_stat_config(tool, config, process, NULL);
2110	if (err < 0) {
2111		pr_err("Couldn't synthesize config.\n");
2112		return err;
2113	}
2114
2115	return 0;
2116}
2117
2118extern const struct perf_header_feature_ops feat_ops[HEADER_LAST_FEATURE];
2119
2120int perf_event__synthesize_features(struct perf_tool *tool, struct perf_session *session,
2121				    struct evlist *evlist, perf_event__handler_t process)
2122{
2123	struct perf_header *header = &session->header;
2124	struct perf_record_header_feature *fe;
2125	struct feat_fd ff;
2126	size_t sz, sz_hdr;
2127	int feat, ret;
2128
2129	sz_hdr = sizeof(fe->header);
2130	sz = sizeof(union perf_event);
2131	/* get a nice alignment */
2132	sz = PERF_ALIGN(sz, page_size);
2133
2134	memset(&ff, 0, sizeof(ff));
2135
2136	ff.buf = malloc(sz);
2137	if (!ff.buf)
2138		return -ENOMEM;
2139
2140	ff.size = sz - sz_hdr;
2141	ff.ph = &session->header;
2142
2143	for_each_set_bit(feat, header->adds_features, HEADER_FEAT_BITS) {
2144		if (!feat_ops[feat].synthesize) {
2145			pr_debug("No record header feature for header :%d\n", feat);
2146			continue;
2147		}
2148
2149		ff.offset = sizeof(*fe);
2150
2151		ret = feat_ops[feat].write(&ff, evlist);
2152		if (ret || ff.offset <= (ssize_t)sizeof(*fe)) {
2153			pr_debug("Error writing feature\n");
2154			continue;
2155		}
2156		/* ff.buf may have changed due to realloc in do_write() */
2157		fe = ff.buf;
2158		memset(fe, 0, sizeof(*fe));
2159
2160		fe->feat_id = feat;
2161		fe->header.type = PERF_RECORD_HEADER_FEATURE;
2162		fe->header.size = ff.offset;
2163
2164		ret = process(tool, ff.buf, NULL, NULL);
2165		if (ret) {
2166			free(ff.buf);
2167			return ret;
2168		}
2169	}
2170
2171	/* Send HEADER_LAST_FEATURE mark. */
2172	fe = ff.buf;
2173	fe->feat_id     = HEADER_LAST_FEATURE;
2174	fe->header.type = PERF_RECORD_HEADER_FEATURE;
2175	fe->header.size = sizeof(*fe);
2176
2177	ret = process(tool, ff.buf, NULL, NULL);
2178
2179	free(ff.buf);
2180	return ret;
2181}