text: // SPDX-License-Identifier: GPL-2.0-only 
  
  #include "util/debug.h"
  #include "util/dso.h"
  #include "util/event.h"
  #include "util/evlist.h"
  #include "util/machine.h"
  #include "util/map.h"
  #include "util/map_symbol.h"
  #include "util/branch.h"
  #include "util/memswap.h"
  #include "util/namespaces.h"
  #include "util/session.h"
  #include "util/stat.h"
  #include "util/symbol.h"
  #include "util/synthetic-events.h"
  #include "util/target.h"
  #include "util/time-utils.h"
  #include "util/cgroup.h"
  #include <linux/bitops.h>
  #include <linux/kernel.h>
  #include <linux/string.h>
  #include <linux/zalloc.h>
  #include <linux/perf_event.h>
  #include <asm/bug.h>
  #include <perf/evsel.h>
  #include <perf/cpumap.h>
  #include <internal/lib.h> // page_size
  #include <internal/threadmap.h>
  #include <perf/threadmap.h>
  #include <symbol/kallsyms.h>
  #include <dirent.h>
  #include <errno.h>
  #include <inttypes.h>
  #include <stdio.h>
  #include <string.h>
  #include <uapi/linux/mman.h> /* To get things like MAP_HUGETLB even on older libc headers */
  #include <api/fs/fs.h>
  #include <api/io.h>
  #include <sys/types.h>
  #include <sys/stat.h>
  #include <fcntl.h>
  #include <unistd.h>
  
  #define DEFAULT_PROC_MAP_PARSE_TIMEOUT 500
  
  unsigned int proc_map_timeout = DEFAULT_PROC_MAP_PARSE_TIMEOUT;
  
  int perf_tool__process_synth_event(struct perf_tool *tool,
  				   union perf_event *event,
  				   struct machine *machine,
  				   perf_event__handler_t process)
  {
  	struct perf_sample synth_sample = {
  		.pid	   = -1,
  		.tid	   = -1,
  		.time	   = -1,
  		.stream_id = -1,
  		.cpu	   = -1,
  		.period	   = 1,
  		.cpumode   = event->header.misc & PERF_RECORD_MISC_CPUMODE_MASK,
  	};
  
  	return process(tool, event, &synth_sample, machine);
  };
  
  /*
   * Assumes that the first 4095 bytes of /proc/pid/stat contains
   * the comm, tgid and ppid.
   */
  static int perf_event__get_comm_ids(pid_t pid, pid_t tid, char *comm, size_t len,
  				    pid_t *tgid, pid_t *ppid, bool *kernel)
  {
  	char bf[4096];
  	int fd;
  	size_t size = 0;
  	ssize_t n;
  	char *name, *tgids, *ppids, *vmpeak, *threads;
  
  	*tgid = -1;
  	*ppid = -1;
  
  	if (pid)
  		snprintf(bf, sizeof(bf), "/proc/%d/task/%d/status", pid, tid);
  	else
  		snprintf(bf, sizeof(bf), "/proc/%d/status", tid);
  
  	fd = open(bf, O_RDONLY);
  	if (fd < 0) {
  		pr_debug("couldn't open %s\n", bf);
  		return -1;
  	}
  
  	n = read(fd, bf, sizeof(bf) - 1);
  	close(fd);
  	if (n <= 0) {
  		pr_warning("Couldn't get COMM, tigd and ppid for pid %d\n",
  			   tid);
  		return -1;
  	}
  	bf[n] = '\0';
  
  	name = strstr(bf, "Name:");
  	tgids = strstr(name ?: bf, "Tgid:");
  	ppids = strstr(tgids ?: bf, "PPid:");
  	vmpeak = strstr(ppids ?: bf, "VmPeak:");
  
  	if (vmpeak)
  		threads = NULL;
  	else
  		threads = strstr(ppids ?: bf, "Threads:");
  
  	if (name) {
  		char *nl;
  
  		name = skip_spaces(name + 5);  /* strlen("Name:") */
  		nl = strchr(name, '\n');
  		if (nl)
  			*nl = '\0';
  
  		size = strlen(name);
  		if (size >= len)
  			size = len - 1;
  		memcpy(comm, name, size);
  		comm[size] = '\0';
  	} else {
  		pr_debug("Name: string not found for pid %d\n", tid);
  	}
  
  	if (tgids) {
  		tgids += 5;  /* strlen("Tgid:") */
  		*tgid = atoi(tgids);
  	} else {
  		pr_debug("Tgid: string not found for pid %d\n", tid);
  	}
  
  	if (ppids) {
  		ppids += 5;  /* strlen("PPid:") */
  		*ppid = atoi(ppids);
  	} else {
  		pr_debug("PPid: string not found for pid %d\n", tid);
  	}
  
  	if (!vmpeak && threads)
  		*kernel = true;
  	else
  		*kernel = false;
  
  	return 0;
  }
  
  static int perf_event__prepare_comm(union perf_event *event, pid_t pid, pid_t tid,
  				    struct machine *machine,
  				    pid_t *tgid, pid_t *ppid, bool *kernel)
  {
  	size_t size;
  
  	*ppid = -1;
  
  	memset(&event->comm, 0, sizeof(event->comm));
  
  	if (machine__is_host(machine)) {
  		if (perf_event__get_comm_ids(pid, tid, event->comm.comm,
  					     sizeof(event->comm.comm),
  					     tgid, ppid, kernel) != 0) {
  			return -1;
  		}
  	} else {
  		*tgid = machine->pid;
  	}
  
  	if (*tgid < 0)
  		return -1;
  
  	event->comm.pid = *tgid;
  	event->comm.header.type = PERF_RECORD_COMM;
  
  	size = strlen(event->comm.comm) + 1;
  	size = PERF_ALIGN(size, sizeof(u64));
  	memset(event->comm.comm + size, 0, machine->id_hdr_size);
  	event->comm.header.size = (sizeof(event->comm) -
  				(sizeof(event->comm.comm) - size) +
  				machine->id_hdr_size);
  	event->comm.tid = tid;
  
  	return 0;
  }
  
  pid_t perf_event__synthesize_comm(struct perf_tool *tool,
  					 union perf_event *event, pid_t pid,
  					 perf_event__handler_t process,
  					 struct machine *machine)
  {
  	pid_t tgid, ppid;
  	bool kernel_thread;
  
  	if (perf_event__prepare_comm(event, 0, pid, machine, &tgid, &ppid,
  				     &kernel_thread) != 0)
  		return -1;
  
  	if (perf_tool__process_synth_event(tool, event, machine, process) != 0)
  		return -1;
  
  	return tgid;
  }
  
  static void perf_event__get_ns_link_info(pid_t pid, const char *ns,
  					 struct perf_ns_link_info *ns_link_info)
  {
  	struct stat64 st;
  	char proc_ns[128];
  
  	sprintf(proc_ns, "/proc/%u/ns/%s", pid, ns);
  	if (stat64(proc_ns, &st) == 0) {
  		ns_link_info->dev = st.st_dev;
  		ns_link_info->ino = st.st_ino;
  	}
  }
  
  int perf_event__synthesize_namespaces(struct perf_tool *tool,
  				      union perf_event *event,
  				      pid_t pid, pid_t tgid,
  				      perf_event__handler_t process,
  				      struct machine *machine)
  {
  	u32 idx;
  	struct perf_ns_link_info *ns_link_info;
  
  	if (!tool || !tool->namespace_events)
  		return 0;
  
  	memset(&event->namespaces, 0, (sizeof(event->namespaces) +
  	       (NR_NAMESPACES * sizeof(struct perf_ns_link_info)) +
  	       machine->id_hdr_size));
  
  	event->namespaces.pid = tgid;
  	event->namespaces.tid = pid;
  
  	event->namespaces.nr_namespaces = NR_NAMESPACES;
  
  	ns_link_info = event->namespaces.link_info;
  
  	for (idx = 0; idx < event->namespaces.nr_namespaces; idx++)
  		perf_event__get_ns_link_info(pid, perf_ns__name(idx),
  					     &ns_link_info[idx]);
  
  	event->namespaces.header.type = PERF_RECORD_NAMESPACES;
  
  	event->namespaces.header.size = (sizeof(event->namespaces) +
  			(NR_NAMESPACES * sizeof(struct perf_ns_link_info)) +
  			machine->id_hdr_size);
  
  	if (perf_tool__process_synth_event(tool, event, machine, process) != 0)
  		return -1;
  
  	return 0;
  }
  
  static int perf_event__synthesize_fork(struct perf_tool *tool,
  				       union perf_event *event,
  				       pid_t pid, pid_t tgid, pid_t ppid,
  				       perf_event__handler_t process,
  				       struct machine *machine)
  {
  	memset(&event->fork, 0, sizeof(event->fork) + machine->id_hdr_size);
  
  	/*
  	 * for main thread set parent to ppid from status file. For other
  	 * threads set parent pid to main thread. ie., assume main thread
  	 * spawns all threads in a process
  	*/
  	if (tgid == pid) {
  		event->fork.ppid = ppid;
  		event->fork.ptid = ppid;
  	} else {
  		event->fork.ppid = tgid;
  		event->fork.ptid = tgid;
  	}
  	event->fork.pid  = tgid;
  	event->fork.tid  = pid;
  	event->fork.header.type = PERF_RECORD_FORK;
  	event->fork.header.misc = PERF_RECORD_MISC_FORK_EXEC;
  
  	event->fork.header.size = (sizeof(event->fork) + machine->id_hdr_size);
  
  	if (perf_tool__process_synth_event(tool, event, machine, process) != 0)
  		return -1;
  
  	return 0;
  }
  
  static bool read_proc_maps_line(struct io *io, __u64 *start, __u64 *end,
  				u32 *prot, u32 *flags, __u64 *offset,
  				u32 *maj, u32 *min,
  				__u64 *inode,
  				ssize_t pathname_size, char *pathname)
  {
  	__u64 temp;
  	int ch;
  	char *start_pathname = pathname;
  
  	if (io__get_hex(io, start) != '-')
  		return false;
  	if (io__get_hex(io, end) != ' ')
  		return false;
  
  	/* map protection and flags bits */
  	*prot = 0;
  	ch = io__get_char(io);
  	if (ch == 'r')
  		*prot |= PROT_READ;
  	else if (ch != '-')
  		return false;
  	ch = io__get_char(io);
  	if (ch == 'w')
  		*prot |= PROT_WRITE;
  	else if (ch != '-')
  		return false;
  	ch = io__get_char(io);
  	if (ch == 'x')
  		*prot |= PROT_EXEC;
  	else if (ch != '-')
  		return false;
  	ch = io__get_char(io);
  	if (ch == 's')
  		*flags = MAP_SHARED;
  	else if (ch == 'p')
  		*flags = MAP_PRIVATE;
  	else
  		return false;
  	if (io__get_char(io) != ' ')
  		return false;
  
  	if (io__get_hex(io, offset) != ' ')
  		return false;
  
  	if (io__get_hex(io, &temp) != ':')
  		return false;
  	*maj = temp;
  	if (io__get_hex(io, &temp) != ' ')
  		return false;
  	*min = temp;
  
  	ch = io__get_dec(io, inode);
  	if (ch != ' ') {
  		*pathname = '\0';
  		return ch == '\n';
  	}
  	do {
  		ch = io__get_char(io);
  	} while (ch == ' ');
  	while (true) {
  		if (ch < 0)
  			return false;
  		if (ch == '\0' || ch == '\n' ||
  		    (pathname + 1 - start_pathname) >= pathname_size) {
  			*pathname = '\0';
  			return true;
  		}
  		*pathname++ = ch;
  		ch = io__get_char(io);
  	}
  }
  
  static void perf_record_mmap2__read_build_id(struct perf_record_mmap2 *event,
  					     bool is_kernel)
  {
  	struct build_id bid;
  	int rc;
  
  	if (is_kernel)
  		rc = sysfs__read_build_id("/sys/kernel/notes", &bid);
  	else
  		rc = filename__read_build_id(event->filename, &bid) > 0 ? 0 : -1;
  
  	if (rc == 0) {
  		memcpy(event->build_id, bid.data, sizeof(bid.data));
  		event->build_id_size = (u8) bid.size;
  		event->header.misc |= PERF_RECORD_MISC_MMAP_BUILD_ID;
  		event->__reserved_1 = 0;
  		event->__reserved_2 = 0;
  	} else {
  		if (event->filename[0] == '/') {
  			pr_debug2("Failed to read build ID for %s\n",
  				  event->filename);
  		}
  	}
  }
  
  int perf_event__synthesize_mmap_events(struct perf_tool *tool,
  				       union perf_event *event,
  				       pid_t pid, pid_t tgid,
  				       perf_event__handler_t process,
  				       struct machine *machine,
  				       bool mmap_data)
  {
  	unsigned long long t;
  	char bf[BUFSIZ];
  	struct io io;
  	bool truncation = false;
  	unsigned long long timeout = proc_map_timeout * 1000000ULL;
  	int rc = 0;
  	const char *hugetlbfs_mnt = hugetlbfs__mountpoint();
  	int hugetlbfs_mnt_len = hugetlbfs_mnt ? strlen(hugetlbfs_mnt) : 0;
  
  	if (machine__is_default_guest(machine))
  		return 0;
  
  	snprintf(bf, sizeof(bf), "%s/proc/%d/task/%d/maps",
  		machine->root_dir, pid, pid);
  
  	io.fd = open(bf, O_RDONLY, 0);
  	if (io.fd < 0) {
  		/*
  		 * We raced with a task exiting - just return:
  		 */
  		pr_debug("couldn't open %s\n", bf);
  		return -1;
  	}
  	io__init(&io, io.fd, bf, sizeof(bf));
  
  	event->header.type = PERF_RECORD_MMAP2;
  	t = rdclock();
  
  	while (!io.eof) {
  		static const char anonstr[] = "//anon";
  		size_t size, aligned_size;
  
  		/* ensure null termination since stack will be reused. */
  		event->mmap2.filename[0] = '\0';
  
  		/* 00400000-0040c000 r-xp 00000000 fd:01 41038  /bin/cat */
  		if (!read_proc_maps_line(&io,
  					&event->mmap2.start,
  					&event->mmap2.len,
  					&event->mmap2.prot,
  					&event->mmap2.flags,
  					&event->mmap2.pgoff,
  					&event->mmap2.maj,
  					&event->mmap2.min,
  					&event->mmap2.ino,
  					sizeof(event->mmap2.filename),
  					event->mmap2.filename))
  			continue;
  
  		if ((rdclock() - t) > timeout) {
  			pr_warning("Reading %s/proc/%d/task/%d/maps time out. "
  				   "You may want to increase "
  				   "the time limit by --proc-map-timeout\n",
  				   machine->root_dir, pid, pid);
  			truncation = true;
  			goto out;
  		}
  
  		event->mmap2.ino_generation = 0;
  
  		/*
  		 * Just like the kernel, see __perf_event_mmap in kernel/perf_event.c
  		 */
  		if (machine__is_host(machine))
  			event->header.misc = PERF_RECORD_MISC_USER;
  		else
  			event->header.misc = PERF_RECORD_MISC_GUEST_USER;
  
  		if ((event->mmap2.prot & PROT_EXEC) == 0) {
  			if (!mmap_data || (event->mmap2.prot & PROT_READ) == 0)
  				continue;
  
  			event->header.misc |= PERF_RECORD_MISC_MMAP_DATA;
  		}
  
  out:
  		if (truncation)
  			event->header.misc |= PERF_RECORD_MISC_PROC_MAP_PARSE_TIMEOUT;
  
  		if (!strcmp(event->mmap2.filename, ""))
  			strcpy(event->mmap2.filename, anonstr);
  
  		if (hugetlbfs_mnt_len &&
  		    !strncmp(event->mmap2.filename, hugetlbfs_mnt,
  			     hugetlbfs_mnt_len)) {
  			strcpy(event->mmap2.filename, anonstr);
  			event->mmap2.flags |= MAP_HUGETLB;
  		}
  
  		size = strlen(event->mmap2.filename) + 1;
  		aligned_size = PERF_ALIGN(size, sizeof(u64));
  		event->mmap2.len -= event->mmap.start;
  		event->mmap2.header.size = (sizeof(event->mmap2) -
  					(sizeof(event->mmap2.filename) - aligned_size));
  		memset(event->mmap2.filename + size, 0, machine->id_hdr_size +
  			(aligned_size - size));
  		event->mmap2.header.size += machine->id_hdr_size;
  		event->mmap2.pid = tgid;
  		event->mmap2.tid = pid;
  
  		if (symbol_conf.buildid_mmap2)
  			perf_record_mmap2__read_build_id(&event->mmap2, false);
  
  		if (perf_tool__process_synth_event(tool, event, machine, process) != 0) {
  			rc = -1;
  			break;
  		}
  
  		if (truncation)
  			break;
  	}
  
  	close(io.fd);
  	return rc;
  }
  
  #ifdef HAVE_FILE_HANDLE
  static int perf_event__synthesize_cgroup(struct perf_tool *tool,
  					 union perf_event *event,
  					 char *path, size_t mount_len,
  					 perf_event__handler_t process,
  					 struct machine *machine)
  {
  	size_t event_size = sizeof(event->cgroup) - sizeof(event->cgroup.path);
  	size_t path_len = strlen(path) - mount_len + 1;
  	struct {
  		struct file_handle fh;
  		uint64_t cgroup_id;
  	} handle;
  	int mount_id;
  
  	while (path_len % sizeof(u64))
  		path[mount_len + path_len++] = '\0';
  
  	memset(&event->cgroup, 0, event_size);
  
  	event->cgroup.header.type = PERF_RECORD_CGROUP;
  	event->cgroup.header.size = event_size + path_len + machine->id_hdr_size;
  
  	handle.fh.handle_bytes = sizeof(handle.cgroup_id);
  	if (name_to_handle_at(AT_FDCWD, path, &handle.fh, &mount_id, 0) < 0) {
  		pr_debug("stat failed: %s\n", path);
  		return -1;
  	}
  
  	event->cgroup.id = handle.cgroup_id;
  	strncpy(event->cgroup.path, path + mount_len, path_len);
  	memset(event->cgroup.path + path_len, 0, machine->id_hdr_size);
  
  	if (perf_tool__process_synth_event(tool, event, machine, process) < 0) {
  		pr_debug("process synth event failed\n");
  		return -1;
  	}
  
  	return 0;
  }
  
  static int perf_event__walk_cgroup_tree(struct perf_tool *tool,
  					union perf_event *event,
  					char *path, size_t mount_len,
  					perf_event__handler_t process,
  					struct machine *machine)
  {
  	size_t pos = strlen(path);
  	DIR *d;
  	struct dirent *dent;
  	int ret = 0;
  
  	if (perf_event__synthesize_cgroup(tool, event, path, mount_len,
  					  process, machine) < 0)
  		return -1;
  
  	d = opendir(path);
  	if (d == NULL) {
  		pr_debug("failed to open directory: %s\n", path);
  		return -1;
  	}
  
  	while ((dent = readdir(d)) != NULL) {
  		if (dent->d_type != DT_DIR)
  			continue;
  		if (!strcmp(dent->d_name, ".") ||
  		    !strcmp(dent->d_name, ".."))
  			continue;
  
  		/* any sane path should be less than PATH_MAX */
  		if (strlen(path) + strlen(dent->d_name) + 1 >= PATH_MAX)
  			continue;
  
  		if (path[pos - 1] != '/')
  			strcat(path, "/");
  		strcat(path, dent->d_name);
  
  		ret = perf_event__walk_cgroup_tree(tool, event, path,
  						   mount_len, process, machine);
  		if (ret < 0)
  			break;
  
  		path[pos] = '\0';
  	}
  
  	closedir(d);
  	return ret;
  }
  
  int perf_event__synthesize_cgroups(struct perf_tool *tool,
  				   perf_event__handler_t process,
  				   struct machine *machine)
  {
  	union perf_event event;
  	char cgrp_root[PATH_MAX];
  	size_t mount_len;  /* length of mount point in the path */
  
  	if (!tool || !tool->cgroup_events)
  		return 0;
  
  	if (cgroupfs_find_mountpoint(cgrp_root, PATH_MAX, "perf_event") < 0) {
  		pr_debug("cannot find cgroup mount point\n");
  		return -1;
  	}
  
  	mount_len = strlen(cgrp_root);
  	/* make sure the path starts with a slash (after mount point) */
  	strcat(cgrp_root, "/");
  
  	if (perf_event__walk_cgroup_tree(tool, &event, cgrp_root, mount_len,
  					 process, machine) < 0)
  		return -1;
  
  	return 0;
  }
  #else
  int perf_event__synthesize_cgroups(struct perf_tool *tool __maybe_unused,
  				   perf_event__handler_t process __maybe_unused,
  				   struct machine *machine __maybe_unused)
  {
  	return -1;
  }
  #endif
  
  int perf_event__synthesize_modules(struct perf_tool *tool, perf_event__handler_t process,
  				   struct machine *machine)
  {
  	int rc = 0;
  	struct map *pos;
  	struct maps *maps = machine__kernel_maps(machine);
  	union perf_event *event;
  	size_t size = symbol_conf.buildid_mmap2 ?
  			sizeof(event->mmap2) : sizeof(event->mmap);
  
  	event = zalloc(size + machine->id_hdr_size);
  	if (event == NULL) {
  		pr_debug("Not enough memory synthesizing mmap event "
  			 "for kernel modules\n");
  		return -1;
  	}
  
  	/*
  	 * kernel uses 0 for user space maps, see kernel/perf_event.c
  	 * __perf_event_mmap
  	 */
  	if (machine__is_host(machine))
  		event->header.misc = PERF_RECORD_MISC_KERNEL;
  	else
  		event->header.misc = PERF_RECORD_MISC_GUEST_KERNEL;
  
  	maps__for_each_entry(maps, pos) {
  		if (!__map__is_kmodule(pos))
  			continue;
  
  		if (symbol_conf.buildid_mmap2) {
  			size = PERF_ALIGN(pos->dso->long_name_len + 1, sizeof(u64));
  			event->mmap2.header.type = PERF_RECORD_MMAP2;
  			event->mmap2.header.size = (sizeof(event->mmap2) -
  						(sizeof(event->mmap2.filename) - size));
  			memset(event->mmap2.filename + size, 0, machine->id_hdr_size);
  			event->mmap2.header.size += machine->id_hdr_size;
  			event->mmap2.start = pos->start;
  			event->mmap2.len   = pos->end - pos->start;
  			event->mmap2.pid   = machine->pid;
  
  			memcpy(event->mmap2.filename, pos->dso->long_name,
  			       pos->dso->long_name_len + 1);
  
  			perf_record_mmap2__read_build_id(&event->mmap2, false);
  		} else {
  			size = PERF_ALIGN(pos->dso->long_name_len + 1, sizeof(u64));
  			event->mmap.header.type = PERF_RECORD_MMAP;
  			event->mmap.header.size = (sizeof(event->mmap) -
  						(sizeof(event->mmap.filename) - size));
  			memset(event->mmap.filename + size, 0, machine->id_hdr_size);
  			event->mmap.header.size += machine->id_hdr_size;
  			event->mmap.start = pos->start;
  			event->mmap.len   = pos->end - pos->start;
  			event->mmap.pid   = machine->pid;
  
  			memcpy(event->mmap.filename, pos->dso->long_name,
  			       pos->dso->long_name_len + 1);
  		}
  
  		if (perf_tool__process_synth_event(tool, event, machine, process) != 0) {
  			rc = -1;
  			break;
  		}
  	}
  
  	free(event);
  	return rc;
  }
  
  static int filter_task(const struct dirent *dirent)
  {
  	return isdigit(dirent->d_name[0]);
  }
  
  static int __event__synthesize_thread(union perf_event *comm_event,
  				      union perf_event *mmap_event,
  				      union perf_event *fork_event,
  				      union perf_event *namespaces_event,
  				      pid_t pid, int full, perf_event__handler_t process,
  				      struct perf_tool *tool, struct machine *machine, bool mmap_data)
  {
  	char filename[PATH_MAX];
  	struct dirent **dirent;
  	pid_t tgid, ppid;
  	int rc = 0;
  	int i, n;
  
  	/* special case: only send one comm event using passed in pid */
  	if (!full) {
  		tgid = perf_event__synthesize_comm(tool, comm_event, pid,
  						   process, machine);
  
  		if (tgid == -1)
  			return -1;
  
  		if (perf_event__synthesize_namespaces(tool, namespaces_event, pid,
  						      tgid, process, machine) < 0)
  			return -1;
  
  		/*
  		 * send mmap only for thread group leader
  		 * see thread__init_maps()
  		 */
  		if (pid == tgid &&
  		    perf_event__synthesize_mmap_events(tool, mmap_event, pid, tgid,
  						       process, machine, mmap_data))
  			return -1;
  
  		return 0;
  	}
  
  	if (machine__is_default_guest(machine))
  		return 0;
  
  	snprintf(filename, sizeof(filename), "%s/proc/%d/task",
  		 machine->root_dir, pid);
  
  	n = scandir(filename, &dirent, filter_task, alphasort);
  	if (n < 0)
  		return n;
  
  	for (i = 0; i < n; i++) {
  		char *end;
  		pid_t _pid;
  		bool kernel_thread = false;
  
  		_pid = strtol(dirent[i]->d_name, &end, 10);
  		if (*end)
  			continue;
  
  		rc = -1;
  		if (perf_event__prepare_comm(comm_event, pid, _pid, machine,
  					     &tgid, &ppid, &kernel_thread) != 0)
  			break;
  
  		if (perf_event__synthesize_fork(tool, fork_event, _pid, tgid,
  						ppid, process, machine) < 0)
  			break;
  
  		if (perf_event__synthesize_namespaces(tool, namespaces_event, _pid,
  						      tgid, process, machine) < 0)
  			break;
  
  		/*
  		 * Send the prepared comm event
  		 */
  		if (perf_tool__process_synth_event(tool, comm_event, machine, process) != 0)
  			break;
  
  		rc = 0;
  		if (_pid == pid && !kernel_thread) {
  			/* process the parent's maps too */
  			rc = perf_event__synthesize_mmap_events(tool, mmap_event, pid, tgid,
  						process, machine, mmap_data);
  			if (rc)
  				break;
  		}
  	}
  
  	for (i = 0; i < n; i++)
  		zfree(&dirent[i]);
  	free(dirent);
  
  	return rc;
  }
  
  int perf_event__synthesize_thread_map(struct perf_tool *tool,
  				      struct perf_thread_map *threads,
  				      perf_event__handler_t process,
  				      struct machine *machine,
  				      bool mmap_data)
  {
  	union perf_event *comm_event, *mmap_event, *fork_event;
  	union perf_event *namespaces_event;
  	int err = -1, thread, j;
  
  	comm_event = malloc(sizeof(comm_event->comm) + machine->id_hdr_size);
  	if (comm_event == NULL)
  		goto out;
  
  	mmap_event = malloc(sizeof(mmap_event->mmap2) + machine->id_hdr_size);
  	if (mmap_event == NULL)
  		goto out_free_comm;
  
  	fork_event = malloc(sizeof(fork_event->fork) + machine->id_hdr_size);
  	if (fork_event == NULL)
  		goto out_free_mmap;
  
  	namespaces_event = malloc(sizeof(namespaces_event->namespaces) +
  				  (NR_NAMESPACES * sizeof(struct perf_ns_link_info)) +
  				  machine->id_hdr_size);
  	if (namespaces_event == NULL)
  		goto out_free_fork;
  
  	err = 0;
  	for (thread = 0; thread < threads->nr; ++thread) {
  		if (__event__synthesize_thread(comm_event, mmap_event,
  					       fork_event, namespaces_event,
  					       perf_thread_map__pid(threads, thread), 0,
  					       process, tool, machine,
  					       mmap_data)) {
  			err = -1;
  			break;
  		}
  
  		/*
  		 * comm.pid is set to thread group id by
  		 * perf_event__synthesize_comm
  		 */
  		if ((int) comm_event->comm.pid != perf_thread_map__pid(threads, thread)) {
  			bool need_leader = true;
  
  			/* is thread group leader in thread_map? */
  			for (j = 0; j < threads->nr; ++j) {
  				if ((int) comm_event->comm.pid == perf_thread_map__pid(threads, j)) {
  					need_leader = false;
  					break;
  				}
  			}
  
  			/* if not, generate events for it */
  			if (need_leader &&
  			    __event__synthesize_thread(comm_event, mmap_event,
  						       fork_event, namespaces_event,
  						       comm_event->comm.pid, 0,
  						       process, tool, machine,
  						       mmap_data)) {
  				err = -1;
  				break;
  			}
  		}
  	}
  	free(namespaces_event);
  out_free_fork:
  	free(fork_event);
  out_free_mmap:
  	free(mmap_event);
  out_free_comm:
  	free(comm_event);
  out:
  	return err;
  }
  
  static int __perf_event__synthesize_threads(struct perf_tool *tool,
  					    perf_event__handler_t process,
  					    struct machine *machine,
  					    bool mmap_data,
  					    struct dirent **dirent,
  					    int start,
  					    int num)
  {
  	union perf_event *comm_event, *mmap_event, *fork_event;
  	union perf_event *namespaces_event;
  	int err = -1;
  	char *end;
  	pid_t pid;
  	int i;
  
  	comm_event = malloc(sizeof(comm_event->comm) + machine->id_hdr_size);
  	if (comm_event == NULL)
  		goto out;
  
  	mmap_event = malloc(sizeof(mmap_event->mmap2) + machine->id_hdr_size);
  	if (mmap_event == NULL)
  		goto out_free_comm;
  
  	fork_event = malloc(sizeof(fork_event->fork) + machine->id_hdr_size);
  	if (fork_event == NULL)
  		goto out_free_mmap;
  
  	namespaces_event = malloc(sizeof(namespaces_event->namespaces) +
  				  (NR_NAMESPACES * sizeof(struct perf_ns_link_info)) +
  				  machine->id_hdr_size);
  	if (namespaces_event == NULL)
  		goto out_free_fork;
  
  	for (i = start; i < start + num; i++) {
  		if (!isdigit(dirent[i]->d_name[0]))
  			continue;
  
  		pid = (pid_t)strtol(dirent[i]->d_name, &end, 10);
  		/* only interested in proper numerical dirents */
  		if (*end)
  			continue;
  		/*
  		 * We may race with exiting thread, so don't stop just because
  		 * one thread couldn't be synthesized.
  		 */
  		__event__synthesize_thread(comm_event, mmap_event, fork_event,
  					   namespaces_event, pid, 1, process,
  					   tool, machine, mmap_data);
  	}
  	err = 0;
  
  	free(namespaces_event);
  out_free_fork:
  	free(fork_event);
  out_free_mmap:
  	free(mmap_event);
  out_free_comm:
  	free(comm_event);
  out:
  	return err;
  }
  
  struct synthesize_threads_arg {
  	struct perf_tool *tool;
  	perf_event__handler_t process;
  	struct machine *machine;
  	bool mmap_data;
  	struct dirent **dirent;
  	int num;
  	int start;
  };
  
  static void *synthesize_threads_worker(void *arg)
  {
  	struct synthesize_threads_arg *args = arg;
  
  	__perf_event__synthesize_threads(args->tool, args->process,
  					 args->machine, args->mmap_data,
  					 args->dirent,
  					 args->start, args->num);
  	return NULL;
  }
  
  int perf_event__synthesize_threads(struct perf_tool *tool,
  				   perf_event__handler_t process,
  				   struct machine *machine,
  				   bool mmap_data,
  				   unsigned int nr_threads_synthesize)
  {
  	struct synthesize_threads_arg *args = NULL;
  	pthread_t *synthesize_threads = NULL;
  	char proc_path[PATH_MAX];
  	struct dirent **dirent;
  	int num_per_thread;
  	int m, n, i, j;
  	int thread_nr;
  	int base = 0;
  	int err = -1;
  
  
  	if (machine__is_default_guest(machine))
  		return 0;
  
  	snprintf(proc_path, sizeof(proc_path), "%s/proc", machine->root_dir);
  	n = scandir(proc_path, &dirent, filter_task, alphasort);
  	if (n < 0)
  		return err;
  
  	if (nr_threads_synthesize == UINT_MAX)
  		thread_nr = sysconf(_SC_NPROCESSORS_ONLN);
  	else
  		thread_nr = nr_threads_synthesize;
  
  	if (thread_nr <= 1) {
  		err = __perf_event__synthesize_threads(tool, process,
  						       machine, mmap_data,
  						       dirent, base, n);
  		goto free_dirent;
  	}
  	if (thread_nr > n)
  		thread_nr = n;
  
  	synthesize_threads = calloc(sizeof(pthread_t), thread_nr);
  	if (synthesize_threads == NULL)
  		goto free_dirent;
  
  	args = calloc(sizeof(*args), thread_nr);
  	if (args == NULL)
  		goto free_threads;
  
  	num_per_thread = n / thread_nr;
  	m = n % thread_nr;
  	for (i = 0; i < thread_nr; i++) {
  		args[i].tool = tool;
  		args[i].process = process;
  		args[i].machine = machine;
  		args[i].mmap_data = mmap_data;
  		args[i].dirent = dirent;
  	}
  	for (i = 0; i < m; i++) {
  		args[i].num = num_per_thread + 1;
  		args[i].start = i * args[i].num;
  	}
  	if (i != 0)
  		base = args[i-1].start + args[i-1].num;
  	for (j = i; j < thread_nr; j++) {
  		args[j].num = num_per_thread;
  		args[j].start = base + (j - i) * args[i].num;
  	}
  
  	for (i = 0; i < thread_nr; i++) {
  		if (pthread_create(&synthesize_threads[i], NULL,
  				   synthesize_threads_worker, &args[i]))
  			goto out_join;
  	}
  	err = 0;
  out_join:
  	for (i = 0; i < thread_nr; i++)
  		pthread_join(synthesize_threads[i], NULL);
  	free(args);
  free_threads:
  	free(synthesize_threads);
  free_dirent:
  	for (i = 0; i < n; i++)
  		zfree(&dirent[i]);
  	free(dirent);
  
  	return err;
  }
  
  int __weak perf_event__synthesize_extra_kmaps(struct perf_tool *tool __maybe_unused,
  					      perf_event__handler_t process __maybe_unused,
  					      struct machine *machine __maybe_unused)
  {
  	return 0;
  }
  
  static int __perf_event__synthesize_kernel_mmap(struct perf_tool *tool,
  						perf_event__handler_t process,
  						struct machine *machine)
  {
  	union perf_event *event;
  	size_t size = symbol_conf.buildid_mmap2 ?
  			sizeof(event->mmap2) : sizeof(event->mmap);
  	struct map *map = machine__kernel_map(machine);
  	struct kmap *kmap;
  	int err;
  
  	if (map == NULL)
  		return -1;
  
  	kmap = map__kmap(map);
  	if (!kmap->ref_reloc_sym)
  		return -1;
  
  	/*
  	 * We should get this from /sys/kernel/sections/.text, but till that is
  	 * available use this, and after it is use this as a fallback for older
  	 * kernels.
  	 */
  	event = zalloc(size + machine->id_hdr_size);
  	if (event == NULL) {
  		pr_debug("Not enough memory synthesizing mmap event "
  			 "for kernel modules\n");
  		return -1;
  	}
  
  	if (machine__is_host(machine)) {
  		/*
  		 * kernel uses PERF_RECORD_MISC_USER for user space maps,
  		 * see kernel/perf_event.c __perf_event_mmap
  		 */
  		event->header.misc = PERF_RECORD_MISC_KERNEL;
  	} else {
  		event->header.misc = PERF_RECORD_MISC_GUEST_KERNEL;
  	}
  
  	if (symbol_conf.buildid_mmap2) {
  		size = snprintf(event->mmap2.filename, sizeof(event->mmap2.filename),
  				"%s%s", machine->mmap_name, kmap->ref_reloc_sym->name) + 1;
  		size = PERF_ALIGN(size, sizeof(u64));
  		event->mmap2.header.type = PERF_RECORD_MMAP2;
  		event->mmap2.header.size = (sizeof(event->mmap2) -
  				(sizeof(event->mmap2.filename) - size) + machine->id_hdr_size);
  		event->mmap2.pgoff = kmap->ref_reloc_sym->addr;
  		event->mmap2.start = map->start;
  		event->mmap2.len   = map->end - event->mmap.start;
  		event->mmap2.pid   = machine->pid;
  
  		perf_record_mmap2__read_build_id(&event->mmap2, true);
  	} else {
  		size = snprintf(event->mmap.filename, sizeof(event->mmap.filename),
  				"%s%s", machine->mmap_name, kmap->ref_reloc_sym->name) + 1;
  		size = PERF_ALIGN(size, sizeof(u64));
  		event->mmap.header.type = PERF_RECORD_MMAP;
  		event->mmap.header.size = (sizeof(event->mmap) -
  				(sizeof(event->mmap.filename) - size) + machine->id_hdr_size);
  		event->mmap.pgoff = kmap->ref_reloc_sym->addr;
  		event->mmap.start = map->start;
  		event->mmap.len   = map->end - event->mmap.start;
  		event->mmap.pid   = machine->pid;
  	}
  
  	err = perf_tool__process_synth_event(tool, event, machine, process);
  	free(event);
  
  	return err;
  }
  
  int perf_event__synthesize_kernel_mmap(struct perf_tool *tool,
  				       perf_event__handler_t process,
  				       struct machine *machine)
  {
  	int err;
  
  	err = __perf_event__synthesize_kernel_mmap(tool, process, machine);
  	if (err < 0)
  		return err;
  
  	return perf_event__synthesize_extra_kmaps(tool, process, machine);
  }
  
  int perf_event__synthesize_thread_map2(struct perf_tool *tool,
  				      struct perf_thread_map *threads,
  				      perf_event__handler_t process,
  				      struct machine *machine)
  {
  	union perf_event *event;
  	int i, err, size;
  
  	size  = sizeof(event->thread_map);
  	size +=	threads->nr * sizeof(event->thread_map.entries[0]);
  
  	event = zalloc(size);
  	if (!event)
  		return -ENOMEM;
  
  	event->header.type = PERF_RECORD_THREAD_MAP;
  	event->header.size = size;
  	event->thread_map.nr = threads->nr;
  
  	for (i = 0; i < threads->nr; i++) {
  		struct perf_record_thread_map_entry *entry = &event->thread_map.entries[i];
  		char *comm = perf_thread_map__comm(threads, i);
  
  		if (!comm)
  			comm = (char *) "";
  
  		entry->pid = perf_thread_map__pid(threads, i);
  		strncpy((char *) &entry->comm, comm, sizeof(entry->comm));
  	}
  
  	err = process(tool, event, NULL, machine);
  
  	free(event);
  	return err;
  }
  
  static void synthesize_cpus(struct cpu_map_entries *cpus,
  			    struct perf_cpu_map *map)
  {
  	int i;
  
  	cpus->nr = map->nr;
  
  	for (i = 0; i < map->nr; i++)
  		cpus->cpu[i] = map->map[i];
  }
  
  static void synthesize_mask(struct perf_record_record_cpu_map *mask,
  			    struct perf_cpu_map *map, int max)
  {
  	int i;
  
  	mask->nr = BITS_TO_LONGS(max);
  	mask->long_size = sizeof(long);
  
  	for (i = 0; i < map->nr; i++)
  		set_bit(map->map[i], mask->mask);
  }
  
  static size_t cpus_size(struct perf_cpu_map *map)
  {
  	return sizeof(struct cpu_map_entries) + map->nr * sizeof(u16);
  }
  
  static size_t mask_size(struct perf_cpu_map *map, int *max)
  {
  	int i;
  
  	*max = 0;
  
  	for (i = 0; i < map->nr; i++) {
  		/* bit position of the cpu is + 1 */
  		int bit = map->map[i] + 1;
  
  		if (bit > *max)
  			*max = bit;
  	}
  
  	return sizeof(struct perf_record_record_cpu_map) + BITS_TO_LONGS(*max) * sizeof(long);
  }
  
  void *cpu_map_data__alloc(struct perf_cpu_map *map, size_t *size, u16 *type, int *max)
  {
  	size_t size_cpus, size_mask;
  	bool is_dummy = perf_cpu_map__empty(map);
  
  	/*
  	 * Both array and mask data have variable size based
  	 * on the number of cpus and their actual values.
  	 * The size of the 'struct perf_record_cpu_map_data' is:
  	 *
  	 *   array = size of 'struct cpu_map_entries' +
  	 *           number of cpus * sizeof(u64)
  	 *
  	 *   mask  = size of 'struct perf_record_record_cpu_map' +
  	 *           maximum cpu bit converted to size of longs
  	 *
  	 * and finally + the size of 'struct perf_record_cpu_map_data'.
  	 */
  	size_cpus = cpus_size(map);
  	size_mask = mask_size(map, max);
  
  	if (is_dummy || (size_cpus < size_mask)) {
  		*size += size_cpus;
  		*type  = PERF_CPU_MAP__CPUS;
  	} else {
  		*size += size_mask;
  		*type  = PERF_CPU_MAP__MASK;
  	}
  
  	*size += sizeof(struct perf_record_cpu_map_data);
  	*size = PERF_ALIGN(*size, sizeof(u64));
  	return zalloc(*size);
  }
  
  void cpu_map_data__synthesize(struct perf_record_cpu_map_data *data, struct perf_cpu_map *map,
  			      u16 type, int max)
  {
  	data->type = type;
  
  	switch (type) {
  	case PERF_CPU_MAP__CPUS:
  		synthesize_cpus((struct cpu_map_entries *) data->data, map);
  		break;
  	case PERF_CPU_MAP__MASK:
  		synthesize_mask((struct perf_record_record_cpu_map *)data->data, map, max);
  	default:
  		break;
  	}
  }
  
  static struct perf_record_cpu_map *cpu_map_event__new(struct perf_cpu_map *map)
  {
  	size_t size = sizeof(struct perf_record_cpu_map);
  	struct perf_record_cpu_map *event;
  	int max;
  	u16 type;
  
  	event = cpu_map_data__alloc(map, &size, &type, &max);
  	if (!event)
  		return NULL;
  
  	event->header.type = PERF_RECORD_CPU_MAP;
  	event->header.size = size;
  	event->data.type   = type;
  
  	cpu_map_data__synthesize(&event->data, map, type, max);
  	return event;
  }
  
  int perf_event__synthesize_cpu_map(struct perf_tool *tool,
  				   struct perf_cpu_map *map,
  				   perf_event__handler_t process,
  				   struct machine *machine)
  {
  	struct perf_record_cpu_map *event;
  	int err;
  
  	event = cpu_map_event__new(map);
  	if (!event)
  		return -ENOMEM;
  
  	err = process(tool, (union perf_event *) event, NULL, machine);
  
  	free(event);
  	return err;
  }
  
  int perf_event__synthesize_stat_config(struct perf_tool *tool,
  				       struct perf_stat_config *config,
  				       perf_event__handler_t process,
  				       struct machine *machine)
  {
  	struct perf_record_stat_config *event;
  	int size, i = 0, err;
  
  	size  = sizeof(*event);
  	size += (PERF_STAT_CONFIG_TERM__MAX * sizeof(event->data[0]));
  
  	event = zalloc(size);
  	if (!event)
  		return -ENOMEM;
  
  	event->header.type = PERF_RECORD_STAT_CONFIG;
  	event->header.size = size;
  	event->nr          = PERF_STAT_CONFIG_TERM__MAX;
  
  #define ADD(__term, __val)					\
  	event->data[i].tag = PERF_STAT_CONFIG_TERM__##__term;	\
  	event->data[i].val = __val;				\
  	i++;
  
  	ADD(AGGR_MODE,	config->aggr_mode)
  	ADD(INTERVAL,	config->interval)
  	ADD(SCALE,	config->scale)
  
  	WARN_ONCE(i != PERF_STAT_CONFIG_TERM__MAX,
  		  "stat config terms unbalanced\n");
  #undef ADD
  
  	err = process(tool, (union perf_event *) event, NULL, machine);
  
  	free(event);
  	return err;
  }
  
  int perf_event__synthesize_stat(struct perf_tool *tool,
  				u32 cpu, u32 thread, u64 id,
  				struct perf_counts_values *count,
  				perf_event__handler_t process,
  				struct machine *machine)
  {
  	struct perf_record_stat event;
  
  	event.header.type = PERF_RECORD_STAT;
  	event.header.size = sizeof(event);
  	event.header.misc = 0;
  
  	event.id        = id;
  	event.cpu       = cpu;
  	event.thread    = thread;
  	event.val       = count->val;
  	event.ena       = count->ena;
  	event.run       = count->run;
  
  	return process(tool, (union perf_event *) &event, NULL, machine);
  }
  
  int perf_event__synthesize_stat_round(struct perf_tool *tool,
  				      u64 evtime, u64 type,
  				      perf_event__handler_t process,
  				      struct machine *machine)
  {
  	struct perf_record_stat_round event;
  
  	event.header.type = PERF_RECORD_STAT_ROUND;
  	event.header.size = sizeof(event);
  	event.header.misc = 0;
  
  	event.time = evtime;
  	event.type = type;
  
  	return process(tool, (union perf_event *) &event, NULL, machine);
  }
  
  size_t perf_event__sample_event_size(const struct perf_sample *sample, u64 type, u64 read_format)
  {
  	size_t sz, result = sizeof(struct perf_record_sample);
  
  	if (type & PERF_SAMPLE_IDENTIFIER)
  		result += sizeof(u64);
  
  	if (type & PERF_SAMPLE_IP)
  		result += sizeof(u64);
  
  	if (type & PERF_SAMPLE_TID)
  		result += sizeof(u64);
  
  	if (type & PERF_SAMPLE_TIME)
  		result += sizeof(u64);
  
  	if (type & PERF_SAMPLE_ADDR)
  		result += sizeof(u64);
  
  	if (type & PERF_SAMPLE_ID)
  		result += sizeof(u64);
  
  	if (type & PERF_SAMPLE_STREAM_ID)
  		result += sizeof(u64);
  
  	if (type & PERF_SAMPLE_CPU)
  		result += sizeof(u64);
  
  	if (type & PERF_SAMPLE_PERIOD)
  		result += sizeof(u64);
  
  	if (type & PERF_SAMPLE_READ) {
  		result += sizeof(u64);
  		if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
  			result += sizeof(u64);
  		if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
  			result += sizeof(u64);
  		/* PERF_FORMAT_ID is forced for PERF_SAMPLE_READ */
  		if (read_format & PERF_FORMAT_GROUP) {
  			sz = sample->read.group.nr *
  			     sizeof(struct sample_read_value);
  			result += sz;
  		} else {
  			result += sizeof(u64);
  		}
  	}
  
  	if (type & PERF_SAMPLE_CALLCHAIN) {
  		sz = (sample->callchain->nr + 1) * sizeof(u64);
  		result += sz;
  	}
  
  	if (type & PERF_SAMPLE_RAW) {
  		result += sizeof(u32);
  		result += sample->raw_size;
  	}
  
  	if (type & PERF_SAMPLE_BRANCH_STACK) {
  		sz = sample->branch_stack->nr * sizeof(struct branch_entry);
  		/* nr, hw_idx */
  		sz += 2 * sizeof(u64);
  		result += sz;
  	}
  
  	if (type & PERF_SAMPLE_REGS_USER) {
  		if (sample->user_regs.abi) {
  			result += sizeof(u64);
  			sz = hweight64(sample->user_regs.mask) * sizeof(u64);
  			result += sz;
  		} else {
  			result += sizeof(u64);
  		}
  	}
  
  	if (type & PERF_SAMPLE_STACK_USER) {
  		sz = sample->user_stack.size;
  		result += sizeof(u64);
  		if (sz) {
  			result += sz;
  			result += sizeof(u64);
  		}
  	}
  
  	if (type & PERF_SAMPLE_WEIGHT_TYPE)
  		result += sizeof(u64);
  
  	if (type & PERF_SAMPLE_DATA_SRC)
  		result += sizeof(u64);
  
  	if (type & PERF_SAMPLE_TRANSACTION)
  		result += sizeof(u64);
  
  	if (type & PERF_SAMPLE_REGS_INTR) {
  		if (sample->intr_regs.abi) {
  			result += sizeof(u64);
  			sz = hweight64(sample->intr_regs.mask) * sizeof(u64);
  			result += sz;
  		} else {
  			result += sizeof(u64);
  		}
  	}
  
  	if (type & PERF_SAMPLE_PHYS_ADDR)
  		result += sizeof(u64);
  
  	if (type & PERF_SAMPLE_CGROUP)
  		result += sizeof(u64);
  
  	if (type & PERF_SAMPLE_DATA_PAGE_SIZE)
  		result += sizeof(u64);
  
  	if (type & PERF_SAMPLE_CODE_PAGE_SIZE)
  		result += sizeof(u64);
  
  	if (type & PERF_SAMPLE_AUX) {
  		result += sizeof(u64);
  		result += sample->aux_sample.size;
  	}
  
  	return result;
  }
  
  void __weak arch_perf_synthesize_sample_weight(const struct perf_sample *data,
  					       __u64 *array, u64 type __maybe_unused)
  {
  	*array = data->weight;
  }
  
  int perf_event__synthesize_sample(union perf_event *event, u64 type, u64 read_format,
  				  const struct perf_sample *sample)
  {
  	__u64 *array;
  	size_t sz;
  	/*
  	 * used for cross-endian analysis. See git commit 65014ab3
  	 * for why this goofiness is needed.
  	 */
  	union u64_swap u;
  
  	array = event->sample.array;
  
  	if (type & PERF_SAMPLE_IDENTIFIER) {
  		*array = sample->id;
  		array++;
  	}
  
  	if (type & PERF_SAMPLE_IP) {
  		*array = sample->ip;
  		array++;
  	}
  
  	if (type & PERF_SAMPLE_TID) {
  		u.val32[0] = sample->pid;
  		u.val32[1] = sample->tid;
  		*array = u.val64;
  		array++;
  	}
  
  	if (type & PERF_SAMPLE_TIME) {
  		*array = sample->time;
  		array++;
  	}
  
  	if (type & PERF_SAMPLE_ADDR) {
  		*array = sample->addr;
  		array++;
  	}
  
  	if (type & PERF_SAMPLE_ID) {
  		*array = sample->id;
  		array++;
  	}
  
  	if (type & PERF_SAMPLE_STREAM_ID) {
  		*array = sample->stream_id;
  		array++;
  	}
  
  	if (type & PERF_SAMPLE_CPU) {
  		u.val32[0] = sample->cpu;
  		u.val32[1] = 0;
  		*array = u.val64;
  		array++;
  	}
  
  	if (type & PERF_SAMPLE_PERIOD) {
  		*array = sample->period;
  		array++;
  	}
  
  	if (type & PERF_SAMPLE_READ) {
  		if (read_format & PERF_FORMAT_GROUP)
  			*array = sample->read.group.nr;
  		else
  			*array = sample->read.one.value;
  		array++;
  
  		if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) {
  			*array = sample->read.time_enabled;
  			array++;
  		}
  
  		if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) {
  			*array = sample->read.time_running;
  			array++;
  		}
  
  		/* PERF_FORMAT_ID is forced for PERF_SAMPLE_READ */
  		if (read_format & PERF_FORMAT_GROUP) {
  			sz = sample->read.group.nr *
  			     sizeof(struct sample_read_value);
  			memcpy(array, sample->read.group.values, sz);
  			array = (void *)array + sz;
  		} else {
  			*array = sample->read.one.id;
  			array++;
  		}
  	}
  
  	if (type & PERF_SAMPLE_CALLCHAIN) {
  		sz = (sample->callchain->nr + 1) * sizeof(u64);
  		memcpy(array, sample->callchain, sz);
  		array = (void *)array + sz;
  	}
  
  	if (type & PERF_SAMPLE_RAW) {
  		u.val32[0] = sample->raw_size;
  		*array = u.val64;
  		array = (void *)array + sizeof(u32);
  
  		memcpy(array, sample->raw_data, sample->raw_size);
  		array = (void *)array + sample->raw_size;
  	}
  
  	if (type & PERF_SAMPLE_BRANCH_STACK) {
  		sz = sample->branch_stack->nr * sizeof(struct branch_entry);
  		/* nr, hw_idx */
  		sz += 2 * sizeof(u64);
  		memcpy(array, sample->branch_stack, sz);
  		array = (void *)array + sz;
  	}
  
  	if (type & PERF_SAMPLE_REGS_USER) {
  		if (sample->user_regs.abi) {
  			*array++ = sample->user_regs.abi;
  			sz = hweight64(sample->user_regs.mask) * sizeof(u64);
  			memcpy(array, sample->user_regs.regs, sz);
  			array = (void *)array + sz;
  		} else {
  			*array++ = 0;
  		}
  	}
  
  	if (type & PERF_SAMPLE_STACK_USER) {
  		sz = sample->user_stack.size;
  		*array++ = sz;
  		if (sz) {
  			memcpy(array, sample->user_stack.data, sz);
  			array = (void *)array + sz;
  			*array++ = sz;
  		}
  	}
  
  	if (type & PERF_SAMPLE_WEIGHT_TYPE) {
  		arch_perf_synthesize_sample_weight(sample, array, type);
  		array++;
  	}
  
  	if (type & PERF_SAMPLE_DATA_SRC) {
  		*array = sample->data_src;
  		array++;
  	}
  
  	if (type & PERF_SAMPLE_TRANSACTION) {
  		*array = sample->transaction;
  		array++;
  	}
  
  	if (type & PERF_SAMPLE_REGS_INTR) {
  		if (sample->intr_regs.abi) {
  			*array++ = sample->intr_regs.abi;
  			sz = hweight64(sample->intr_regs.mask) * sizeof(u64);
  			memcpy(array, sample->intr_regs.regs, sz);
  			array = (void *)array + sz;
  		} else {
  			*array++ = 0;
  		}
  	}
  
  	if (type & PERF_SAMPLE_PHYS_ADDR) {
  		*array = sample->phys_addr;
  		array++;
  	}
  
  	if (type & PERF_SAMPLE_CGROUP) {
  		*array = sample->cgroup;
  		array++;
  	}
  
  	if (type & PERF_SAMPLE_DATA_PAGE_SIZE) {
  		*array = sample->data_page_size;
  		array++;
  	}
  
  	if (type & PERF_SAMPLE_CODE_PAGE_SIZE) {
  		*array = sample->code_page_size;
  		array++;
  	}
  
  	if (type & PERF_SAMPLE_AUX) {
  		sz = sample->aux_sample.size;
  		*array++ = sz;
  		memcpy(array, sample->aux_sample.data, sz);
  		array = (void *)array + sz;
  	}
  
  	return 0;
  }
  
  int perf_event__synthesize_id_index(struct perf_tool *tool, perf_event__handler_t process,
  				    struct evlist *evlist, struct machine *machine)
  {
  	union perf_event *ev;
  	struct evsel *evsel;
  	size_t nr = 0, i = 0, sz, max_nr, n;
  	int err;
  
  	pr_debug2("Synthesizing id index\n");
  
  	max_nr = (UINT16_MAX - sizeof(struct perf_record_id_index)) /
  		 sizeof(struct id_index_entry);
  
  	evlist__for_each_entry(evlist, evsel)
  		nr += evsel->core.ids;
  
  	n = nr > max_nr ? max_nr : nr;
  	sz = sizeof(struct perf_record_id_index) + n * sizeof(struct id_index_entry);
  	ev = zalloc(sz);
  	if (!ev)
  		return -ENOMEM;
  
  	ev->id_index.header.type = PERF_RECORD_ID_INDEX;
  	ev->id_index.header.size = sz;
  	ev->id_index.nr = n;
  
  	evlist__for_each_entry(evlist, evsel) {
  		u32 j;
  
  		for (j = 0; j < evsel->core.ids; j++) {
  			struct id_index_entry *e;
  			struct perf_sample_id *sid;
  
  			if (i >= n) {
  				err = process(tool, ev, NULL, machine);
  				if (err)
  					goto out_err;
  				nr -= n;
  				i = 0;
  			}
  
  			e = &ev->id_index.entries[i++];
  
  			e->id = evsel->core.id[j];
  
  			sid = evlist__id2sid(evlist, e->id);
  			if (!sid) {
  				free(ev);
  				return -ENOENT;
  			}
  
  			e->idx = sid->idx;
  			e->cpu = sid->cpu;
  			e->tid = sid->tid;
  		}
  	}
  
  	sz = sizeof(struct perf_record_id_index) + nr * sizeof(struct id_index_entry);
  	ev->id_index.header.size = sz;
  	ev->id_index.nr = nr;
  
  	err = process(tool, ev, NULL, machine);
  out_err:
  	free(ev);
  
  	return err;
  }
  
  int __machine__synthesize_threads(struct machine *machine, struct perf_tool *tool,
  				  struct target *target, struct perf_thread_map *threads,
  				  perf_event__handler_t process, bool data_mmap,
  				  unsigned int nr_threads_synthesize)
  {
  	if (target__has_task(target))
  		return perf_event__synthesize_thread_map(tool, threads, process, machine, data_mmap);
  	else if (target__has_cpu(target))
  		return perf_event__synthesize_threads(tool, process,
  						      machine, data_mmap,
  						      nr_threads_synthesize);
  	/* command specified */
  	return 0;
  }
  
  int machine__synthesize_threads(struct machine *machine, struct target *target,
  				struct perf_thread_map *threads, bool data_mmap,
  				unsigned int nr_threads_synthesize)
  {
  	return __machine__synthesize_threads(machine, NULL, target, threads,
  					     perf_event__process, data_mmap,
  					     nr_threads_synthesize);
  }
  
  static struct perf_record_event_update *event_update_event__new(size_t size, u64 type, u64 id)
  {
  	struct perf_record_event_update *ev;
  
  	size += sizeof(*ev);
  	size  = PERF_ALIGN(size, sizeof(u64));
  
  	ev = zalloc(size);
  	if (ev) {
  		ev->header.type = PERF_RECORD_EVENT_UPDATE;
  		ev->header.size = (u16)size;
  		ev->type	= type;
  		ev->id		= id;
  	}
  	return ev;
  }
  
  int perf_event__synthesize_event_update_unit(struct perf_tool *tool, struct evsel *evsel,
  					     perf_event__handler_t process)
  {
  	size_t size = strlen(evsel->unit);
  	struct perf_record_event_update *ev;
  	int err;
  
  	ev = event_update_event__new(size + 1, PERF_EVENT_UPDATE__UNIT, evsel->core.id[0]);
  	if (ev == NULL)
  		return -ENOMEM;
  
  	strlcpy(ev->data, evsel->unit, size + 1);
  	err = process(tool, (union perf_event *)ev, NULL, NULL);
  	free(ev);
  	return err;
  }
  
  int perf_event__synthesize_event_update_scale(struct perf_tool *tool, struct evsel *evsel,
  					      perf_event__handler_t process)
  {
  	struct perf_record_event_update *ev;
  	struct perf_record_event_update_scale *ev_data;
  	int err;
  
  	ev = event_update_event__new(sizeof(*ev_data), PERF_EVENT_UPDATE__SCALE, evsel->core.id[0]);
  	if (ev == NULL)
  		return -ENOMEM;
  
  	ev_data = (struct perf_record_event_update_scale *)ev->data;
  	ev_data->scale = evsel->scale;
  	err = process(tool, (union perf_event *)ev, NULL, NULL);
  	free(ev);
  	return err;
  }
  
  int perf_event__synthesize_event_update_name(struct perf_tool *tool, struct evsel *evsel,
  					     perf_event__handler_t process)
  {
  	struct perf_record_event_update *ev;
  	size_t len = strlen(evsel->name);
  	int err;
  
  	ev = event_update_event__new(len + 1, PERF_EVENT_UPDATE__NAME, evsel->core.id[0]);
  	if (ev == NULL)
  		return -ENOMEM;
  
  	strlcpy(ev->data, evsel->name, len + 1);
  	err = process(tool, (union perf_event *)ev, NULL, NULL);
  	free(ev);
  	return err;
  }
  
  int perf_event__synthesize_event_update_cpus(struct perf_tool *tool, struct evsel *evsel,
  					     perf_event__handler_t process)
  {
  	size_t size = sizeof(struct perf_record_event_update);
  	struct perf_record_event_update *ev;
  	int max, err;
  	u16 type;
  
  	if (!evsel->core.own_cpus)
  		return 0;
  
  	ev = cpu_map_data__alloc(evsel->core.own_cpus, &size, &type, &max);
  	if (!ev)
  		return -ENOMEM;
  
  	ev->header.type = PERF_RECORD_EVENT_UPDATE;
  	ev->header.size = (u16)size;
  	ev->type	= PERF_EVENT_UPDATE__CPUS;
  	ev->id		= evsel->core.id[0];
  
  	cpu_map_data__synthesize((struct perf_record_cpu_map_data *)ev->data,
  				 evsel->core.own_cpus, type, max);
  
  	err = process(tool, (union perf_event *)ev, NULL, NULL);
  	free(ev);
  	return err;
  }
  
  int perf_event__synthesize_attrs(struct perf_tool *tool, struct evlist *evlist,
  				 perf_event__handler_t process)
  {
  	struct evsel *evsel;
  	int err = 0;
  
  	evlist__for_each_entry(evlist, evsel) {
  		err = perf_event__synthesize_attr(tool, &evsel->core.attr, evsel->core.ids,
  						  evsel->core.id, process);
  		if (err) {
  			pr_debug("failed to create perf header attribute\n");
  			return err;
  		}
  	}
  
  	return err;
  }
  
  static bool has_unit(struct evsel *evsel)
  {
  	return evsel->unit && *evsel->unit;
  }
  
  static bool has_scale(struct evsel *evsel)
  {
  	return evsel->scale != 1;
  }
  
  int perf_event__synthesize_extra_attr(struct perf_tool *tool, struct evlist *evsel_list,
  				      perf_event__handler_t process, bool is_pipe)
  {
  	struct evsel *evsel;
  	int err;
  
  	/*
  	 * Synthesize other events stuff not carried within
  	 * attr event - unit, scale, name
  	 */
  	evlist__for_each_entry(evsel_list, evsel) {
  		if (!evsel->supported)
  			continue;
  
  		/*
  		 * Synthesize unit and scale only if it's defined.
  		 */
  		if (has_unit(evsel)) {
  			err = perf_event__synthesize_event_update_unit(tool, evsel, process);
  			if (err < 0) {
  				pr_err("Couldn't synthesize evsel unit.\n");
  				return err;
  			}
  		}
  
  		if (has_scale(evsel)) {
  			err = perf_event__synthesize_event_update_scale(tool, evsel, process);
  			if (err < 0) {
  				pr_err("Couldn't synthesize evsel evsel.\n");
  				return err;
  			}
  		}
  
  		if (evsel->core.own_cpus) {
  			err = perf_event__synthesize_event_update_cpus(tool, evsel, process);
  			if (err < 0) {
  				pr_err("Couldn't synthesize evsel cpus.\n");
  				return err;
  			}
  		}
  
  		/*
  		 * Name is needed only for pipe output,
  		 * perf.data carries event names.
  		 */
  		if (is_pipe) {
  			err = perf_event__synthesize_event_update_name(tool, evsel, process);
  			if (err < 0) {
  				pr_err("Couldn't synthesize evsel name.\n");
  				return err;
  			}
  		}
  	}
  	return 0;
  }
  
  int perf_event__synthesize_attr(struct perf_tool *tool, struct perf_event_attr *attr,
  				u32 ids, u64 *id, perf_event__handler_t process)
  {
  	union perf_event *ev;
  	size_t size;
  	int err;
  
  	size = sizeof(struct perf_event_attr);
  	size = PERF_ALIGN(size, sizeof(u64));
  	size += sizeof(struct perf_event_header);
  	size += ids * sizeof(u64);
  
  	ev = zalloc(size);
  
  	if (ev == NULL)
  		return -ENOMEM;
  
  	ev->attr.attr = *attr;
  	memcpy(ev->attr.id, id, ids * sizeof(u64));
  
  	ev->attr.header.type = PERF_RECORD_HEADER_ATTR;
  	ev->attr.header.size = (u16)size;
  
  	if (ev->attr.header.size == size)
  		err = process(tool, ev, NULL, NULL);
  	else
  		err = -E2BIG;
  
  	free(ev);
  
  	return err;
  }
  
  int perf_event__synthesize_tracing_data(struct perf_tool *tool, int fd, struct evlist *evlist,
  					perf_event__handler_t process)
  {
  	union perf_event ev;
  	struct tracing_data *tdata;
  	ssize_t size = 0, aligned_size = 0, padding;
  	struct feat_fd ff;
  
  	/*
  	 * We are going to store the size of the data followed
  	 * by the data contents. Since the fd descriptor is a pipe,
  	 * we cannot seek back to store the size of the data once
  	 * we know it. Instead we:
  	 *
  	 * - write the tracing data to the temp file
  	 * - get/write the data size to pipe
  	 * - write the tracing data from the temp file
  	 *   to the pipe
  	 */
  	tdata = tracing_data_get(&evlist->core.entries, fd, true);
  	if (!tdata)
  		return -1;
  
  	memset(&ev, 0, sizeof(ev));
  
  	ev.tracing_data.header.type = PERF_RECORD_HEADER_TRACING_DATA;
  	size = tdata->size;
  	aligned_size = PERF_ALIGN(size, sizeof(u64));
  	padding = aligned_size - size;
  	ev.tracing_data.header.size = sizeof(ev.tracing_data);
  	ev.tracing_data.size = aligned_size;
  
  	process(tool, &ev, NULL, NULL);
  
  	/*
  	 * The put function will copy all the tracing data
  	 * stored in temp file to the pipe.
  	 */
  	tracing_data_put(tdata);
  
  	ff = (struct feat_fd){ .fd = fd };
  	if (write_padded(&ff, NULL, 0, padding))
  		return -1;
  
  	return aligned_size;
  }
  
  int perf_event__synthesize_build_id(struct perf_tool *tool, struct dso *pos, u16 misc,
  				    perf_event__handler_t process, struct machine *machine)
  {
  	union perf_event ev;
  	size_t len;
  
  	if (!pos->hit)
  		return 0;
  
  	memset(&ev, 0, sizeof(ev));
  
  	len = pos->long_name_len + 1;
  	len = PERF_ALIGN(len, NAME_ALIGN);
  	memcpy(&ev.build_id.build_id, pos->bid.data, sizeof(pos->bid.data));
  	ev.build_id.header.type = PERF_RECORD_HEADER_BUILD_ID;
  	ev.build_id.header.misc = misc;
  	ev.build_id.pid = machine->pid;
  	ev.build_id.header.size = sizeof(ev.build_id) + len;
  	memcpy(&ev.build_id.filename, pos->long_name, pos->long_name_len);
  
  	return process(tool, &ev, NULL, machine);
  }
  
  int perf_event__synthesize_stat_events(struct perf_stat_config *config, struct perf_tool *tool,
  				       struct evlist *evlist, perf_event__handler_t process, bool attrs)
  {
  	int err;
  
  	if (attrs) {
  		err = perf_event__synthesize_attrs(tool, evlist, process);
  		if (err < 0) {
  			pr_err("Couldn't synthesize attrs.\n");
  			return err;
  		}
  	}
  
  	err = perf_event__synthesize_extra_attr(tool, evlist, process, attrs);
  	err = perf_event__synthesize_thread_map2(tool, evlist->core.threads, process, NULL);
  	if (err < 0) {
  		pr_err("Couldn't synthesize thread map.\n");
  		return err;
  	}
  
  	err = perf_event__synthesize_cpu_map(tool, evlist->core.cpus, process, NULL);
  	if (err < 0) {
  		pr_err("Couldn't synthesize thread map.\n");
  		return err;
  	}
  
  	err = perf_event__synthesize_stat_config(tool, config, process, NULL);
  	if (err < 0) {
  		pr_err("Couldn't synthesize config.\n");
  		return err;
  	}
  
  	return 0;
  }
  
  extern const struct perf_header_feature_ops feat_ops[HEADER_LAST_FEATURE];
  
  int perf_event__synthesize_features(struct perf_tool *tool, struct perf_session *session,
  				    struct evlist *evlist, perf_event__handler_t process)
  {
  	struct perf_header *header = &session->header;
  	struct perf_record_header_feature *fe;
  	struct feat_fd ff;
  	size_t sz, sz_hdr;
  	int feat, ret;
  
  	sz_hdr = sizeof(fe->header);
  	sz = sizeof(union perf_event);
  	/* get a nice alignment */
  	sz = PERF_ALIGN(sz, page_size);
  
  	memset(&ff, 0, sizeof(ff));
  
  	ff.buf = malloc(sz);
  	if (!ff.buf)
  		return -ENOMEM;
  
  	ff.size = sz - sz_hdr;
  	ff.ph = &session->header;
  
  	for_each_set_bit(feat, header->adds_features, HEADER_FEAT_BITS) {
  		if (!feat_ops[feat].synthesize) {
  			pr_debug("No record header feature for header :%d\n", feat);
  			continue;
  		}
  
  		ff.offset = sizeof(*fe);
  
  		ret = feat_ops[feat].write(&ff, evlist);
  		if (ret || ff.offset <= (ssize_t)sizeof(*fe)) {
  			pr_debug("Error writing feature\n");
  			continue;
  		}
  		/* ff.buf may have changed due to realloc in do_write() */
  		fe = ff.buf;
  		memset(fe, 0, sizeof(*fe));
  
  		fe->feat_id = feat;
  		fe->header.type = PERF_RECORD_HEADER_FEATURE;
  		fe->header.size = ff.offset;
  
  		ret = process(tool, ff.buf, NULL, NULL);
  		if (ret) {
  			free(ff.buf);
  			return ret;
  		}
  	}
  
  	/* Send HEADER_LAST_FEATURE mark. */
  	fe = ff.buf;
  	fe->feat_id     = HEADER_LAST_FEATURE;
  	fe->header.type = PERF_RECORD_HEADER_FEATURE;
  	fe->header.size = sizeof(*fe);
  
  	ret = process(tool, ff.buf, NULL, NULL);
  
  	free(ff.buf);
  	return ret;
  }
  