Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 2416 insertions, 0 deletions

diff --git a/tools/perf/util/synthetic-events.c b/tools/perf/util/synthetic-events.c
new file mode 100644
index 0000000000..a0579c7d7b
--- /dev/null
+++ b/tools/perf/util/synthetic-events.c
@@ -0,0 +1,2416 @@
+// SPDX-License-Identifier: GPL-2.0-only 
+
+#include "util/cgroup.h"
+#include "util/data.h"
+#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 <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,
+					     struct machine *machine,
+					     bool is_kernel)
+{
+	struct build_id bid;
+	struct nsinfo *nsi;
+	struct nscookie nc;
+	struct dso *dso = NULL;
+	struct dso_id id;
+	int rc;
+
+	if (is_kernel) {
+		rc = sysfs__read_build_id("/sys/kernel/notes", &bid);
+		goto out;
+	}
+
+	id.maj = event->maj;
+	id.min = event->min;
+	id.ino = event->ino;
+	id.ino_generation = event->ino_generation;
+
+	dso = dsos__findnew_id(&machine->dsos, event->filename, &id);
+	if (dso && dso->has_build_id) {
+		bid = dso->bid;
+		rc = 0;
+		goto out;
+	}
+
+	nsi = nsinfo__new(event->pid);
+	nsinfo__mountns_enter(nsi, &nc);
+
+	rc = filename__read_build_id(event->filename, &bid) > 0 ? 0 : -1;
+
+	nsinfo__mountns_exit(&nc);
+	nsinfo__put(nsi);
+
+out:
+	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;
+
+		if (dso && !dso->has_build_id)
+			dso__set_build_id(dso, &bid);
+	} else {
+		if (event->filename[0] == '/') {
+			pr_debug2("Failed to read build ID for %s\n",
+				  event->filename);
+		}
+	}
+	dso__put(dso);
+}
+
+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, machine, 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_rb_node *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) {
+		struct map *map = pos->map;
+		struct dso *dso;
+
+		if (!__map__is_kmodule(map))
+			continue;
+
+		dso = map__dso(map);
+		if (symbol_conf.buildid_mmap2) {
+			size = PERF_ALIGN(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 = map__start(map);
+			event->mmap2.len   = map__size(map);
+			event->mmap2.pid   = machine->pid;
+
+			memcpy(event->mmap2.filename, dso->long_name, dso->long_name_len + 1);
+
+			perf_record_mmap2__read_build_id(&event->mmap2, machine, false);
+		} else {
+			size = PERF_ALIGN(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 = map__start(map);
+			event->mmap.len   = map__size(map);
+			event->mmap.pid   = machine->pid;
+
+			memcpy(event->mmap.filename, dso->long_name, 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 needs_mmap, 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 && needs_mmap &&
+		    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, NULL);
+	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;
+
+		/* some threads may exit just after scan, ignore it */
+		if (perf_event__prepare_comm(comm_event, pid, _pid, machine,
+					     &tgid, &ppid, &kernel_thread) != 0)
+			continue;
+
+		rc = -1;
+		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 && needs_mmap) {
+			/* 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 needs_mmap, 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,
+					       needs_mmap, 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,
+						       needs_mmap, 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 needs_mmap,
+					    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, needs_mmap, 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 needs_mmap;
+	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->needs_mmap, 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 needs_mmap, 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, NULL);
+	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,
+						       needs_mmap, 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].needs_mmap = needs_mmap;
+		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(map);
+		event->mmap2.len   = map__end(map) - event->mmap.start;
+		event->mmap2.pid   = machine->pid;
+
+		perf_record_mmap2__read_build_id(&event->mmap2, machine, 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(map);
+		event->mmap.len   = map__end(map) - 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;
+}
+
+struct synthesize_cpu_map_data {
+	const struct perf_cpu_map *map;
+	int nr;
+	int min_cpu;
+	int max_cpu;
+	int has_any_cpu;
+	int type;
+	size_t size;
+	struct perf_record_cpu_map_data *data;
+};
+
+static void synthesize_cpus(struct synthesize_cpu_map_data *data)
+{
+	data->data->type = PERF_CPU_MAP__CPUS;
+	data->data->cpus_data.nr = data->nr;
+	for (int i = 0; i < data->nr; i++)
+		data->data->cpus_data.cpu[i] = perf_cpu_map__cpu(data->map, i).cpu;
+}
+
+static void synthesize_mask(struct synthesize_cpu_map_data *data)
+{
+	int idx;
+	struct perf_cpu cpu;
+
+	/* Due to padding, the 4bytes per entry mask variant is always smaller. */
+	data->data->type = PERF_CPU_MAP__MASK;
+	data->data->mask32_data.nr = BITS_TO_U32(data->max_cpu);
+	data->data->mask32_data.long_size = 4;
+
+	perf_cpu_map__for_each_cpu(cpu, idx, data->map) {
+		int bit_word = cpu.cpu / 32;
+		u32 bit_mask = 1U << (cpu.cpu & 31);
+
+		data->data->mask32_data.mask[bit_word] |= bit_mask;
+	}
+}
+
+static void synthesize_range_cpus(struct synthesize_cpu_map_data *data)
+{
+	data->data->type = PERF_CPU_MAP__RANGE_CPUS;
+	data->data->range_cpu_data.any_cpu = data->has_any_cpu;
+	data->data->range_cpu_data.start_cpu = data->min_cpu;
+	data->data->range_cpu_data.end_cpu = data->max_cpu;
+}
+
+static void *cpu_map_data__alloc(struct synthesize_cpu_map_data *syn_data,
+				 size_t header_size)
+{
+	size_t size_cpus, size_mask;
+
+	syn_data->nr = perf_cpu_map__nr(syn_data->map);
+	syn_data->has_any_cpu = (perf_cpu_map__cpu(syn_data->map, 0).cpu == -1) ? 1 : 0;
+
+	syn_data->min_cpu = perf_cpu_map__cpu(syn_data->map, syn_data->has_any_cpu).cpu;
+	syn_data->max_cpu = perf_cpu_map__max(syn_data->map).cpu;
+	if (syn_data->max_cpu - syn_data->min_cpu + 1 == syn_data->nr - syn_data->has_any_cpu) {
+		/* A consecutive range of CPUs can be encoded using a range. */
+		assert(sizeof(u16) + sizeof(struct perf_record_range_cpu_map) == sizeof(u64));
+		syn_data->type = PERF_CPU_MAP__RANGE_CPUS;
+		syn_data->size = header_size + sizeof(u64);
+		return zalloc(syn_data->size);
+	}
+
+	size_cpus = sizeof(u16) + sizeof(struct cpu_map_entries) + syn_data->nr * sizeof(u16);
+	/* Due to padding, the 4bytes per entry mask variant is always smaller. */
+	size_mask = sizeof(u16) + sizeof(struct perf_record_mask_cpu_map32) +
+		BITS_TO_U32(syn_data->max_cpu) * sizeof(__u32);
+	if (syn_data->has_any_cpu || size_cpus < size_mask) {
+		/* Follow the CPU map encoding. */
+		syn_data->type = PERF_CPU_MAP__CPUS;
+		syn_data->size = header_size + PERF_ALIGN(size_cpus, sizeof(u64));
+		return zalloc(syn_data->size);
+	}
+	/* Encode using a bitmask. */
+	syn_data->type = PERF_CPU_MAP__MASK;
+	syn_data->size = header_size + PERF_ALIGN(size_mask, sizeof(u64));
+	return zalloc(syn_data->size);
+}
+
+static void cpu_map_data__synthesize(struct synthesize_cpu_map_data *data)
+{
+	switch (data->type) {
+	case PERF_CPU_MAP__CPUS:
+		synthesize_cpus(data);
+		break;
+	case PERF_CPU_MAP__MASK:
+		synthesize_mask(data);
+		break;
+	case PERF_CPU_MAP__RANGE_CPUS:
+		synthesize_range_cpus(data);
+		break;
+	default:
+		break;
+	}
+}
+
+static struct perf_record_cpu_map *cpu_map_event__new(const struct perf_cpu_map *map)
+{
+	struct synthesize_cpu_map_data syn_data = { .map = map };
+	struct perf_record_cpu_map *event;
+
+
+	event = cpu_map_data__alloc(&syn_data, sizeof(struct perf_event_header));
+	if (!event)
+		return NULL;
+
+	syn_data.data = &event->data;
+	event->header.type = PERF_RECORD_CPU_MAP;
+	event->header.size = syn_data.size;
+	cpu_map_data__synthesize(&syn_data);
+	return event;
+}
+
+
+int perf_event__synthesize_cpu_map(struct perf_tool *tool,
+				   const 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)
+	ADD(AGGR_LEVEL,	config->aggr_level)
+
+	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,
+				struct perf_cpu 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.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_value_size(read_format);
+			result += sz * sample->read.group.nr;
+		} else {
+			result += sizeof(u64);
+			if (read_format & PERF_FORMAT_LOST)
+				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;
+}
+
+static __u64 *copy_read_group_values(__u64 *array, __u64 read_format,
+				     const struct perf_sample *sample)
+{
+	size_t sz = sample_read_value_size(read_format);
+	struct sample_read_value *v = sample->read.group.values;
+
+	sample_read_group__for_each(v, sample->read.group.nr, read_format) {
+		/* PERF_FORMAT_ID is forced for PERF_SAMPLE_READ */
+		memcpy(array, v, sz);
+		array = (void *)array + sz;
+	}
+	return array;
+}
+
+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) {
+			array = copy_read_group_values(array, read_format,
+						       sample);
+		} else {
+			*array = sample->read.one.id;
+			array++;
+
+			if (read_format & PERF_FORMAT_LOST) {
+				*array = sample->read.one.lost;
+				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_sample(__u64 *array, u64 type, const struct perf_sample *sample)
+{
+	__u64 *start = array;
+
+	/*
+	 * used for cross-endian analysis. See git commit 65014ab3
+	 * for why this goofiness is needed.
+	 */
+	union u64_swap u;
+
+	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_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_IDENTIFIER) {
+		*array = sample->id;
+		array++;
+	}
+
+	return (void *)array - (void *)start;
+}
+
+int __perf_event__synthesize_id_index(struct perf_tool *tool, perf_event__handler_t process,
+				      struct evlist *evlist, struct machine *machine, size_t from)
+{
+	union perf_event *ev;
+	struct evsel *evsel;
+	size_t nr = 0, i = 0, sz, max_nr, n, pos;
+	size_t e1_sz = sizeof(struct id_index_entry);
+	size_t e2_sz = sizeof(struct id_index_entry_2);
+	size_t etot_sz = e1_sz + e2_sz;
+	bool e2_needed = false;
+	int err;
+
+	max_nr = (UINT16_MAX - sizeof(struct perf_record_id_index)) / etot_sz;
+
+	pos = 0;
+	evlist__for_each_entry(evlist, evsel) {
+		if (pos++ < from)
+			continue;
+		nr += evsel->core.ids;
+	}
+
+	if (!nr)
+		return 0;
+
+	pr_debug2("Synthesizing id index\n");
+
+	n = nr > max_nr ? max_nr : nr;
+	sz = sizeof(struct perf_record_id_index) + n * etot_sz;
+	ev = zalloc(sz);
+	if (!ev)
+		return -ENOMEM;
+
+	sz = sizeof(struct perf_record_id_index) + n * e1_sz;
+
+	ev->id_index.header.type = PERF_RECORD_ID_INDEX;
+	ev->id_index.nr = n;
+
+	pos = 0;
+	evlist__for_each_entry(evlist, evsel) {
+		u32 j;
+
+		if (pos++ < from)
+			continue;
+		for (j = 0; j < evsel->core.ids; j++, i++) {
+			struct id_index_entry *e;
+			struct id_index_entry_2 *e2;
+			struct perf_sample_id *sid;
+
+			if (i >= n) {
+				ev->id_index.header.size = sz + (e2_needed ? n * e2_sz : 0);
+				err = process(tool, ev, NULL, machine);
+				if (err)
+					goto out_err;
+				nr -= n;
+				i = 0;
+				e2_needed = false;
+			}
+
+			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.cpu;
+			e->tid = sid->tid;
+
+			if (sid->machine_pid)
+				e2_needed = true;
+
+			e2 = (void *)ev + sz;
+			e2[i].machine_pid = sid->machine_pid;
+			e2[i].vcpu        = sid->vcpu.cpu;
+		}
+	}
+
+	sz = sizeof(struct perf_record_id_index) + nr * e1_sz;
+	ev->id_index.header.size = sz + (e2_needed ? nr * e2_sz : 0);
+	ev->id_index.nr = nr;
+
+	err = process(tool, ev, NULL, machine);
+out_err:
+	free(ev);
+
+	return err;
+}
+
+int perf_event__synthesize_id_index(struct perf_tool *tool, perf_event__handler_t process,
+				    struct evlist *evlist, struct machine *machine)
+{
+	return __perf_event__synthesize_id_index(tool, process, evlist, machine, 0);
+}
+
+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 needs_mmap,
+				  bool data_mmap, unsigned int nr_threads_synthesize)
+{
+	/*
+	 * When perf runs in non-root PID namespace, and the namespace's proc FS
+	 * is not mounted, nsinfo__is_in_root_namespace() returns false.
+	 * In this case, the proc FS is coming for the parent namespace, thus
+	 * perf tool will wrongly gather process info from its parent PID
+	 * namespace.
+	 *
+	 * To avoid the confusion that the perf tool runs in a child PID
+	 * namespace but it synthesizes thread info from its parent PID
+	 * namespace, returns failure with warning.
+	 */
+	if (!nsinfo__is_in_root_namespace()) {
+		pr_err("Perf runs in non-root PID namespace but it tries to ");
+		pr_err("gather process info from its parent PID namespace.\n");
+		pr_err("Please mount the proc file system properly, e.g. ");
+		pr_err("add the option '--mount-proc' for unshare command.\n");
+		return -EPERM;
+	}
+
+	if (target__has_task(target))
+		return perf_event__synthesize_thread_map(tool, threads, process, machine,
+							 needs_mmap, data_mmap);
+	else if (target__has_cpu(target))
+		return perf_event__synthesize_threads(tool, process, machine,
+						      needs_mmap, 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 needs_mmap,
+				bool data_mmap, unsigned int nr_threads_synthesize)
+{
+	return __machine__synthesize_threads(machine, NULL, target, threads,
+					     perf_event__process, needs_mmap,
+					     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->unit, 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->scale.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(evsel));
+	int err;
+
+	ev = event_update_event__new(len + 1, PERF_EVENT_UPDATE__NAME, evsel->core.id[0]);
+	if (ev == NULL)
+		return -ENOMEM;
+
+	strlcpy(ev->name, 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)
+{
+	struct synthesize_cpu_map_data syn_data = { .map = evsel->core.own_cpus };
+	struct perf_record_event_update *ev;
+	int err;
+
+	ev = cpu_map_data__alloc(&syn_data, sizeof(struct perf_event_header) + 2 * sizeof(u64));
+	if (!ev)
+		return -ENOMEM;
+
+	syn_data.data = &ev->cpus.cpus;
+	ev->header.type = PERF_RECORD_EVENT_UPDATE;
+	ev->header.size = (u16)syn_data.size;
+	ev->type	= PERF_EVENT_UPDATE__CPUS;
+	ev->id		= evsel->core.id[0];
+	cpu_map_data__synthesize(&syn_data);
+
+	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(perf_record_header_attr_id(ev), 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;
+}
+
+#ifdef HAVE_LIBTRACEEVENT
+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;
+}
+#endif
+
+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);
+	ev.build_id.size = min(pos->bid.size, sizeof(pos->bid.data));
+	memcpy(&ev.build_id.build_id, pos->bid.data, ev.build_id.size);
+	ev.build_id.header.type = PERF_RECORD_HEADER_BUILD_ID;
+	ev.build_id.header.misc = misc | PERF_RECORD_MISC_BUILD_ID_SIZE;
+	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.user_requested_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;
+}
+
+int perf_event__synthesize_for_pipe(struct perf_tool *tool,
+				    struct perf_session *session,
+				    struct perf_data *data,
+				    perf_event__handler_t process)
+{
+	int err;
+	int ret = 0;
+	struct evlist *evlist = session->evlist;
+
+	/*
+	 * We need to synthesize events first, because some
+	 * features works on top of them (on report side).
+	 */
+	err = perf_event__synthesize_attrs(tool, evlist, process);
+	if (err < 0) {
+		pr_err("Couldn't synthesize attrs.\n");
+		return err;
+	}
+	ret += err;
+
+	err = perf_event__synthesize_features(tool, session, evlist, process);
+	if (err < 0) {
+		pr_err("Couldn't synthesize features.\n");
+		return err;
+	}
+	ret += err;
+
+#ifdef HAVE_LIBTRACEEVENT
+	if (have_tracepoints(&evlist->core.entries)) {
+		int fd = perf_data__fd(data);
+
+		/*
+		 * FIXME err <= 0 here actually means that
+		 * there were no tracepoints so its not really
+		 * an error, just that we don't need to
+		 * synthesize anything.  We really have to
+		 * return this more properly and also
+		 * propagate errors that now are calling die()
+		 */
+		err = perf_event__synthesize_tracing_data(tool,	fd, evlist,
+							  process);
+		if (err <= 0) {
+			pr_err("Couldn't record tracing data.\n");
+			return err;
+		}
+		ret += err;
+	}
+#else
+	(void)data;
+#endif
+
+	return ret;
+}
+
+int parse_synth_opt(char *synth)
+{
+	char *p, *q;
+	int ret = 0;
+
+	if (synth == NULL)
+		return -1;
+
+	for (q = synth; (p = strsep(&q, ",")); p = q) {
+		if (!strcasecmp(p, "no") || !strcasecmp(p, "none"))
+			return 0;
+
+		if (!strcasecmp(p, "all"))
+			return PERF_SYNTH_ALL;
+
+		if (!strcasecmp(p, "task"))
+			ret |= PERF_SYNTH_TASK;
+		else if (!strcasecmp(p, "mmap"))
+			ret |= PERF_SYNTH_TASK | PERF_SYNTH_MMAP;
+		else if (!strcasecmp(p, "cgroup"))
+			ret |= PERF_SYNTH_CGROUP;
+		else
+			return -1;
+	}
+
+	return ret;
+}