root/tools/perf/builtin-inject.c
// SPDX-License-Identifier: GPL-2.0
/*
 * builtin-inject.c
 *
 * Builtin inject command: Examine the live mode (stdin) event stream
 * and repipe it to stdout while optionally injecting additional
 * events into it.
 */
#include "builtin.h"

#include "util/color.h"
#include "util/dso.h"
#include "util/vdso.h"
#include "util/evlist.h"
#include "util/evsel.h"
#include "util/map.h"
#include "util/session.h"
#include "util/tool.h"
#include "util/debug.h"
#include "util/build-id.h"
#include "util/data.h"
#include "util/auxtrace.h"
#include "util/jit.h"
#include "util/string2.h"
#include "util/symbol.h"
#include "util/synthetic-events.h"
#include "util/thread.h"
#include "util/namespaces.h"
#include "util/util.h"
#include "util/tsc.h"

#include <internal/lib.h>

#include <linux/err.h>
#include <subcmd/parse-options.h>
#include <uapi/linux/mman.h> /* To get things like MAP_HUGETLB even on older libc headers */

#include <linux/list.h>
#include <linux/string.h>
#include <linux/zalloc.h>
#include <linux/hash.h>
#include <ctype.h>
#include <errno.h>
#include <signal.h>
#include <inttypes.h>

struct guest_event {
        struct perf_sample              sample;
        union perf_event                *event;
        char                            *event_buf;
};

struct guest_id {
        /* hlist_node must be first, see free_hlist() */
        struct hlist_node               node;
        u64                             id;
        u64                             host_id;
        u32                             vcpu;
};

struct guest_tid {
        /* hlist_node must be first, see free_hlist() */
        struct hlist_node               node;
        /* Thread ID of QEMU thread */
        u32                             tid;
        u32                             vcpu;
};

struct guest_vcpu {
        /* Current host CPU */
        u32                             cpu;
        /* Thread ID of QEMU thread */
        u32                             tid;
};

struct guest_session {
        char                            *perf_data_file;
        u32                             machine_pid;
        u64                             time_offset;
        double                          time_scale;
        struct perf_tool                tool;
        struct perf_data                data;
        struct perf_session             *session;
        char                            *tmp_file_name;
        int                             tmp_fd;
        struct perf_tsc_conversion      host_tc;
        struct perf_tsc_conversion      guest_tc;
        bool                            copy_kcore_dir;
        bool                            have_tc;
        bool                            fetched;
        bool                            ready;
        u16                             dflt_id_hdr_size;
        u64                             dflt_id;
        u64                             highest_id;
        /* Array of guest_vcpu */
        struct guest_vcpu               *vcpu;
        size_t                          vcpu_cnt;
        /* Hash table for guest_id */
        struct hlist_head               heads[PERF_EVLIST__HLIST_SIZE];
        /* Hash table for guest_tid */
        struct hlist_head               tids[PERF_EVLIST__HLIST_SIZE];
        /* Place to stash next guest event */
        struct guest_event              ev;
};

enum build_id_rewrite_style {
        BID_RWS__NONE = 0,
        BID_RWS__INJECT_HEADER_LAZY,
        BID_RWS__INJECT_HEADER_ALL,
        BID_RWS__MMAP2_BUILDID_ALL,
        BID_RWS__MMAP2_BUILDID_LAZY,
};

struct perf_inject {
        struct perf_tool        tool;
        struct perf_session     *session;
        enum build_id_rewrite_style build_id_style;
        bool                    sched_stat;
        bool                    have_auxtrace;
        bool                    strip;
        bool                    jit_mode;
        bool                    in_place_update;
        bool                    in_place_update_dry_run;
        bool                    copy_kcore_dir;
        bool                    convert_callchain;
        const char              *input_name;
        struct perf_data        output;
        u64                     bytes_written;
        u64                     aux_id;
        struct list_head        samples;
        struct itrace_synth_opts itrace_synth_opts;
        char                    *event_copy;
        struct perf_file_section secs[HEADER_FEAT_BITS];
        struct guest_session    guest_session;
        struct strlist          *known_build_ids;
        const struct evsel      *mmap_evsel;
        struct ip_callchain     *raw_callchain;
};

struct event_entry {
        struct list_head node;
        u32              tid;
        union perf_event event[];
};

static int tool__inject_build_id(const struct perf_tool *tool,
                                 struct perf_sample *sample,
                                 struct machine *machine,
                                 const struct evsel *evsel,
                                 __u16 misc,
                                 const char *filename,
                                 struct dso *dso, u32 flags);
static int tool__inject_mmap2_build_id(const struct perf_tool *tool,
                                      struct perf_sample *sample,
                                      struct machine *machine,
                                      const struct evsel *evsel,
                                      __u16 misc,
                                      __u32 pid, __u32 tid,
                                      __u64 start, __u64 len, __u64 pgoff,
                                      struct dso *dso,
                                      __u32 prot, __u32 flags,
                                      const char *filename);

static int output_bytes(struct perf_inject *inject, void *buf, size_t sz)
{
        ssize_t size;

        size = perf_data__write(&inject->output, buf, sz);
        if (size < 0)
                return -errno;

        inject->bytes_written += size;
        return 0;
}

static int perf_event__repipe_synth(const struct perf_tool *tool,
                                    union perf_event *event)

{
        struct perf_inject *inject = container_of(tool, struct perf_inject,
                                                  tool);

        return output_bytes(inject, event, event->header.size);
}

static int perf_event__repipe_oe_synth(const struct perf_tool *tool,
                                       union perf_event *event,
                                       struct ordered_events *oe __maybe_unused)
{
        return perf_event__repipe_synth(tool, event);
}

#ifdef HAVE_JITDUMP
static int perf_event__drop_oe(const struct perf_tool *tool __maybe_unused,
                               union perf_event *event __maybe_unused,
                               struct ordered_events *oe __maybe_unused)
{
        return 0;
}
#endif

static int perf_event__repipe_op2_synth(const struct perf_tool *tool,
                                        struct perf_session *session __maybe_unused,
                                        union perf_event *event)
{
        return perf_event__repipe_synth(tool, event);
}

static int perf_event__repipe_op4_synth(const struct perf_tool *tool,
                                        struct perf_session *session __maybe_unused,
                                        union perf_event *event,
                                        u64 data __maybe_unused,
                                        const char *str __maybe_unused)
{
        return perf_event__repipe_synth(tool, event);
}

static int perf_event__repipe_attr(const struct perf_tool *tool,
                                   union perf_event *event,
                                   struct evlist **pevlist)
{
        struct perf_inject *inject = container_of(tool, struct perf_inject,
                                                  tool);
        int ret;

        ret = perf_event__process_attr(tool, event, pevlist);
        if (ret)
                return ret;

        /* If the output isn't a pipe then the attributes will be written as part of the header. */
        if (!inject->output.is_pipe)
                return 0;

        return perf_event__repipe_synth(tool, event);
}

static int perf_event__repipe_event_update(const struct perf_tool *tool,
                                           union perf_event *event,
                                           struct evlist **pevlist __maybe_unused)
{
        return perf_event__repipe_synth(tool, event);
}

static int copy_bytes(struct perf_inject *inject, struct perf_data *data, off_t size)
{
        char buf[4096];
        ssize_t ssz;
        int ret;

        while (size > 0) {
                ssz = perf_data__read(data, buf, min(size, (off_t)sizeof(buf)));
                if (ssz < 0)
                        return -errno;
                ret = output_bytes(inject, buf, ssz);
                if (ret)
                        return ret;
                size -= ssz;
        }

        return 0;
}

static s64 perf_event__repipe_auxtrace(const struct perf_tool *tool,
                                       struct perf_session *session,
                                       union perf_event *event)
{
        struct perf_inject *inject = container_of(tool, struct perf_inject, tool);
        int ret;

        inject->have_auxtrace = true;

        if (!inject->output.is_pipe) {
                off_t offset;

                offset = lseek(inject->output.file.fd, 0, SEEK_CUR);
                if (offset == -1)
                        return -errno;
                ret = auxtrace_index__auxtrace_event(&session->auxtrace_index,
                                                     event, offset);
                if (ret < 0)
                        return ret;
        }

        if (perf_data__is_pipe(session->data) || !session->one_mmap) {
                ret = output_bytes(inject, event, event->header.size);
                if (ret < 0)
                        return ret;
                ret = copy_bytes(inject, session->data,
                                 event->auxtrace.size);
        } else {
                ret = output_bytes(inject, event,
                                   event->header.size + event->auxtrace.size);
        }
        if (ret < 0)
                return ret;

        return event->auxtrace.size;
}

static int perf_event__repipe(const struct perf_tool *tool,
                              union perf_event *event,
                              struct perf_sample *sample __maybe_unused,
                              struct machine *machine __maybe_unused)
{
        return perf_event__repipe_synth(tool, event);
}

static int perf_event__drop(const struct perf_tool *tool __maybe_unused,
                            union perf_event *event __maybe_unused,
                            struct perf_sample *sample __maybe_unused,
                            struct machine *machine __maybe_unused)
{
        return 0;
}

static int perf_event__drop_aux(const struct perf_tool *tool,
                                union perf_event *event __maybe_unused,
                                struct perf_sample *sample,
                                struct machine *machine __maybe_unused)
{
        struct perf_inject *inject = container_of(tool, struct perf_inject, tool);

        if (!inject->aux_id)
                inject->aux_id = sample->id;

        return 0;
}

static union perf_event *
perf_inject__cut_auxtrace_sample(struct perf_inject *inject,
                                 union perf_event *event,
                                 struct perf_sample *sample)
{
        size_t sz1 = sample->aux_sample.data - (void *)event;
        size_t sz2 = event->header.size - sample->aux_sample.size - sz1;
        union perf_event *ev;

        if (inject->event_copy == NULL) {
                inject->event_copy = malloc(PERF_SAMPLE_MAX_SIZE);
                if (!inject->event_copy)
                        return ERR_PTR(-ENOMEM);
        }
        ev = (union perf_event *)inject->event_copy;
        if (sz1 > event->header.size || sz2 > event->header.size ||
            sz1 + sz2 > event->header.size ||
            sz1 < sizeof(struct perf_event_header) + sizeof(u64))
                return event;

        memcpy(ev, event, sz1);
        memcpy((void *)ev + sz1, (void *)event + event->header.size - sz2, sz2);
        ev->header.size = sz1 + sz2;
        ((u64 *)((void *)ev + sz1))[-1] = 0;

        return ev;
}

typedef int (*inject_handler)(const struct perf_tool *tool,
                              union perf_event *event,
                              struct perf_sample *sample,
                              struct evsel *evsel,
                              struct machine *machine);

static int perf_event__repipe_sample(const struct perf_tool *tool,
                                     union perf_event *event,
                                     struct perf_sample *sample,
                                     struct evsel *evsel,
                                     struct machine *machine)
{
        struct perf_inject *inject = container_of(tool, struct perf_inject,
                                                  tool);

        if (evsel && evsel->handler) {
                inject_handler f = evsel->handler;
                return f(tool, event, sample, evsel, machine);
        }

        build_id__mark_dso_hit(tool, event, sample, evsel, machine);

        if (inject->itrace_synth_opts.set && sample->aux_sample.size) {
                event = perf_inject__cut_auxtrace_sample(inject, event, sample);
                if (IS_ERR(event))
                        return PTR_ERR(event);
        }

        return perf_event__repipe_synth(tool, event);
}

static int perf_event__convert_sample_callchain(const struct perf_tool *tool,
                                                union perf_event *event,
                                                struct perf_sample *sample,
                                                struct evsel *evsel,
                                                struct machine *machine)
{
        struct perf_inject *inject = container_of(tool, struct perf_inject, tool);
        struct callchain_cursor *cursor = get_tls_callchain_cursor();
        union perf_event *event_copy = (void *)inject->event_copy;
        struct callchain_cursor_node *node;
        struct thread *thread;
        u64 sample_type = evsel->core.attr.sample_type;
        u32 sample_size = event->header.size;
        u64 i, k;
        int ret;

        if (event_copy == NULL) {
                inject->event_copy = malloc(PERF_SAMPLE_MAX_SIZE);
                if (!inject->event_copy)
                        return -ENOMEM;

                event_copy = (void *)inject->event_copy;
        }

        if (cursor == NULL)
                return -ENOMEM;

        callchain_cursor_reset(cursor);

        thread = machine__find_thread(machine, sample->tid, sample->pid);
        if (thread == NULL)
                goto out;

        /* this will parse DWARF using stack and register data */
        ret = thread__resolve_callchain(thread, cursor, evsel, sample,
                                        /*parent=*/NULL, /*root_al=*/NULL,
                                        PERF_MAX_STACK_DEPTH);
        thread__put(thread);
        if (ret != 0)
                goto out;

        /* copy kernel callchain and context entries */
        for (i = 0; i < sample->callchain->nr; i++) {
                inject->raw_callchain->ips[i] = sample->callchain->ips[i];
                if (sample->callchain->ips[i] == PERF_CONTEXT_USER) {
                        i++;
                        break;
                }
        }
        if (i == 0 || inject->raw_callchain->ips[i - 1] != PERF_CONTEXT_USER)
                inject->raw_callchain->ips[i++] = PERF_CONTEXT_USER;

        node = cursor->first;
        for (k = 0; k < cursor->nr && i < PERF_MAX_STACK_DEPTH; k++) {
                if (machine__kernel_ip(machine, node->ip))
                        /* kernel IPs were added already */;
                else if (node->ms.sym && node->ms.sym->inlined)
                        /* we can't handle inlined callchains */;
                else
                        inject->raw_callchain->ips[i++] = node->ip;

                node = node->next;
        }

        inject->raw_callchain->nr = i;
        sample->callchain = inject->raw_callchain;

out:
        memcpy(event_copy, event, sizeof(event->header));

        /* adjust sample size for stack and regs */
        sample_size -= sample->user_stack.size;
        sample_size -= (hweight64(evsel->core.attr.sample_regs_user) + 1) * sizeof(u64);
        sample_size += (sample->callchain->nr + 1) * sizeof(u64);
        event_copy->header.size = sample_size;

        /* remove sample_type {STACK,REGS}_USER for synthesize */
        sample_type &= ~(PERF_SAMPLE_STACK_USER | PERF_SAMPLE_REGS_USER);

        perf_event__synthesize_sample(event_copy, sample_type,
                                      evsel->core.attr.read_format, sample);
        return perf_event__repipe_synth(tool, event_copy);
}

static struct dso *findnew_dso(int pid, int tid, const char *filename,
                               const struct dso_id *id, struct machine *machine)
{
        struct thread *thread;
        struct nsinfo *nsi = NULL;
        struct nsinfo *nnsi;
        struct dso *dso;
        bool vdso;

        thread = machine__findnew_thread(machine, pid, tid);
        if (thread == NULL) {
                pr_err("cannot find or create a task %d/%d.\n", tid, pid);
                return NULL;
        }

        vdso = is_vdso_map(filename);
        nsi = nsinfo__get(thread__nsinfo(thread));

        if (vdso) {
                /* The vdso maps are always on the host and not the
                 * container.  Ensure that we don't use setns to look
                 * them up.
                 */
                nnsi = nsinfo__copy(nsi);
                if (nnsi) {
                        nsinfo__put(nsi);
                        nsinfo__clear_need_setns(nnsi);
                        nsi = nnsi;
                }
                dso = machine__findnew_vdso(machine, thread);
        } else {
                dso = machine__findnew_dso_id(machine, filename, id);
        }

        if (dso) {
                mutex_lock(dso__lock(dso));
                dso__set_nsinfo(dso, nsi);
                mutex_unlock(dso__lock(dso));
        } else
                nsinfo__put(nsi);

        thread__put(thread);
        return dso;
}

/*
 * The evsel used for the sample ID for mmap events. Typically stashed when
 * processing mmap events. If not stashed, search the evlist for the first mmap
 * gathering event.
 */
static const struct evsel *inject__mmap_evsel(struct perf_inject *inject)
{
        struct evsel *pos;

        if (inject->mmap_evsel)
                return inject->mmap_evsel;

        evlist__for_each_entry(inject->session->evlist, pos) {
                if (pos->core.attr.mmap) {
                        inject->mmap_evsel = pos;
                        return pos;
                }
        }
        pr_err("No mmap events found\n");
        return NULL;
}

static int perf_event__repipe_common_mmap(const struct perf_tool *tool,
                                          union perf_event *event,
                                          struct perf_sample *sample,
                                          struct machine *machine,
                                          __u32 pid, __u32 tid,
                                          __u64 start, __u64 len, __u64 pgoff,
                                          __u32 flags, __u32 prot,
                                          const char *filename,
                                          const struct dso_id *dso_id,
                                          int (*perf_event_process)(const struct perf_tool *tool,
                                                                    union perf_event *event,
                                                                    struct perf_sample *sample,
                                                                    struct machine *machine))
{
        struct perf_inject *inject = container_of(tool, struct perf_inject, tool);
        struct dso *dso = NULL;
        bool dso_sought = false;

#ifdef HAVE_JITDUMP
        if (inject->jit_mode) {
                u64 n = 0;
                int ret;

                /* If jit marker, then inject jit mmaps and generate ELF images. */
                ret = jit_process(inject->session, &inject->output, machine,
                                  filename, pid, tid, &n);
                if (ret < 0)
                        return ret;
                if (ret) {
                        inject->bytes_written += n;
                        return 0;
                }
        }
#endif
        if (event->header.misc & PERF_RECORD_MISC_MMAP_BUILD_ID) {
                dso = findnew_dso(pid, tid, filename, dso_id, machine);
                dso_sought = true;
                if (dso) {
                        /* mark it not to inject build-id */
                        dso__set_hit(dso);
                }
        }
        if (inject->build_id_style == BID_RWS__INJECT_HEADER_ALL) {
                if (!dso_sought) {
                        dso = findnew_dso(pid, tid, filename, dso_id, machine);
                        dso_sought = true;
                }

                if (dso && !dso__hit(dso)) {
                        struct evsel *evsel = evlist__event2evsel(inject->session->evlist, event);

                        if (evsel) {
                                dso__set_hit(dso);
                                tool__inject_build_id(tool, sample, machine, evsel,
                                                      /*misc=*/sample->cpumode,
                                                      filename, dso, flags);
                        }
                }
        } else {
                int err;

                /*
                 * Remember the evsel for lazy build id generation. It is used
                 * for the sample id header type.
                 */
                if ((inject->build_id_style == BID_RWS__INJECT_HEADER_LAZY ||
                     inject->build_id_style == BID_RWS__MMAP2_BUILDID_LAZY) &&
                    !inject->mmap_evsel)
                        inject->mmap_evsel = evlist__event2evsel(inject->session->evlist, event);

                /* Create the thread, map, etc. Not done for the unordered inject all case. */
                err = perf_event_process(tool, event, sample, machine);

                if (err) {
                        dso__put(dso);
                        return err;
                }
        }
        if ((inject->build_id_style == BID_RWS__MMAP2_BUILDID_ALL) &&
            !(event->header.misc & PERF_RECORD_MISC_MMAP_BUILD_ID)) {
                struct evsel *evsel = evlist__event2evsel(inject->session->evlist, event);

                if (evsel && !dso_sought) {
                        dso = findnew_dso(pid, tid, filename, dso_id, machine);
                        dso_sought = true;
                }
                if (evsel && dso &&
                    !tool__inject_mmap2_build_id(tool, sample, machine, evsel,
                                                 sample->cpumode | PERF_RECORD_MISC_MMAP_BUILD_ID,
                                                 pid, tid, start, len, pgoff,
                                                 dso,
                                                 prot, flags,
                                                 filename)) {
                        /* Injected mmap2 so no need to repipe. */
                        dso__put(dso);
                        return 0;
                }
        }
        dso__put(dso);
        if (inject->build_id_style == BID_RWS__MMAP2_BUILDID_LAZY)
                return 0;

        return perf_event__repipe(tool, event, sample, machine);
}

static int perf_event__repipe_mmap(const struct perf_tool *tool,
                                union perf_event *event,
                                struct perf_sample *sample,
                                struct machine *machine)
{
        return perf_event__repipe_common_mmap(
                tool, event, sample, machine,
                event->mmap.pid, event->mmap.tid,
                event->mmap.start, event->mmap.len, event->mmap.pgoff,
                /*flags=*/0, PROT_EXEC,
                event->mmap.filename, /*dso_id=*/NULL,
                perf_event__process_mmap);
}

static int perf_event__repipe_mmap2(const struct perf_tool *tool,
                                union perf_event *event,
                                struct perf_sample *sample,
                                struct machine *machine)
{
        struct dso_id id = dso_id_empty;

        if (event->header.misc & PERF_RECORD_MISC_MMAP_BUILD_ID) {
                build_id__init(&id.build_id, event->mmap2.build_id, event->mmap2.build_id_size);
        } else {
                id.maj = event->mmap2.maj;
                id.min = event->mmap2.min;
                id.ino = event->mmap2.ino;
                id.ino_generation = event->mmap2.ino_generation;
                id.mmap2_valid = true;
                id.mmap2_ino_generation_valid = true;
        }

        return perf_event__repipe_common_mmap(
                tool, event, sample, machine,
                event->mmap2.pid, event->mmap2.tid,
                event->mmap2.start, event->mmap2.len, event->mmap2.pgoff,
                event->mmap2.flags, event->mmap2.prot,
                event->mmap2.filename, &id,
                perf_event__process_mmap2);
}

static int perf_event__repipe_fork(const struct perf_tool *tool,
                                   union perf_event *event,
                                   struct perf_sample *sample,
                                   struct machine *machine)
{
        int err;

        err = perf_event__process_fork(tool, event, sample, machine);
        perf_event__repipe(tool, event, sample, machine);

        return err;
}

static int perf_event__repipe_comm(const struct perf_tool *tool,
                                   union perf_event *event,
                                   struct perf_sample *sample,
                                   struct machine *machine)
{
        int err;

        err = perf_event__process_comm(tool, event, sample, machine);
        perf_event__repipe(tool, event, sample, machine);

        return err;
}

static int perf_event__repipe_namespaces(const struct perf_tool *tool,
                                         union perf_event *event,
                                         struct perf_sample *sample,
                                         struct machine *machine)
{
        int err = perf_event__process_namespaces(tool, event, sample, machine);

        perf_event__repipe(tool, event, sample, machine);

        return err;
}

static int perf_event__repipe_exit(const struct perf_tool *tool,
                                   union perf_event *event,
                                   struct perf_sample *sample,
                                   struct machine *machine)
{
        int err;

        err = perf_event__process_exit(tool, event, sample, machine);
        perf_event__repipe(tool, event, sample, machine);

        return err;
}

#ifdef HAVE_LIBTRACEEVENT
static int perf_event__repipe_tracing_data(const struct perf_tool *tool,
                                           struct perf_session *session,
                                           union perf_event *event)
{
        perf_event__repipe_synth(tool, event);

        return perf_event__process_tracing_data(tool, session, event);
}
#endif

static int dso__read_build_id(struct dso *dso)
{
        struct nscookie nsc;
        struct build_id bid = { .size = 0, };

        if (dso__has_build_id(dso))
                return 0;

        mutex_lock(dso__lock(dso));
        nsinfo__mountns_enter(dso__nsinfo(dso), &nsc);
        if (filename__read_build_id(dso__long_name(dso), &bid) > 0)
                dso__set_build_id(dso, &bid);
        else if (dso__nsinfo(dso)) {
                char *new_name = dso__filename_with_chroot(dso, dso__long_name(dso));

                if (new_name && filename__read_build_id(new_name, &bid) > 0)
                        dso__set_build_id(dso, &bid);
                free(new_name);
        }
        nsinfo__mountns_exit(&nsc);
        mutex_unlock(dso__lock(dso));

        return dso__has_build_id(dso) ? 0 : -1;
}

static struct strlist *perf_inject__parse_known_build_ids(
        const char *known_build_ids_string)
{
        struct str_node *pos, *tmp;
        struct strlist *known_build_ids;
        int bid_len;

        known_build_ids = strlist__new(known_build_ids_string, NULL);
        if (known_build_ids == NULL)
                return NULL;
        strlist__for_each_entry_safe(pos, tmp, known_build_ids) {
                const char *build_id, *dso_name;

                build_id = skip_spaces(pos->s);
                dso_name = strchr(build_id, ' ');
                if (dso_name == NULL) {
                        strlist__remove(known_build_ids, pos);
                        continue;
                }
                bid_len = dso_name - pos->s;
                dso_name = skip_spaces(dso_name);
                if (bid_len % 2 != 0 || bid_len >= SBUILD_ID_SIZE) {
                        strlist__remove(known_build_ids, pos);
                        continue;
                }
                for (int ix = 0; 2 * ix + 1 < bid_len; ++ix) {
                        if (!isxdigit(build_id[2 * ix]) ||
                            !isxdigit(build_id[2 * ix + 1])) {
                                strlist__remove(known_build_ids, pos);
                                break;
                        }
                }
        }
        return known_build_ids;
}

static bool perf_inject__lookup_known_build_id(struct perf_inject *inject,
                                               struct dso *dso)
{
        struct str_node *pos;

        strlist__for_each_entry(pos, inject->known_build_ids) {
                struct build_id bid;
                const char *build_id, *dso_name;
                size_t bid_len;

                build_id = skip_spaces(pos->s);
                dso_name = strchr(build_id, ' ');
                bid_len = dso_name - pos->s;
                if (bid_len > sizeof(bid.data))
                        bid_len = sizeof(bid.data);
                dso_name = skip_spaces(dso_name);
                if (strcmp(dso__long_name(dso), dso_name))
                        continue;
                for (size_t ix = 0; 2 * ix + 1 < bid_len; ++ix) {
                        bid.data[ix] = (hex(build_id[2 * ix]) << 4 |
                                        hex(build_id[2 * ix + 1]));
                }
                bid.size = bid_len / 2;
                dso__set_build_id(dso, &bid);
                return true;
        }
        return false;
}

static int tool__inject_build_id(const struct perf_tool *tool,
                                 struct perf_sample *sample,
                                 struct machine *machine,
                                 const struct evsel *evsel,
                                 __u16 misc,
                                 const char *filename,
                                 struct dso *dso, u32 flags)
{
        struct perf_inject *inject = container_of(tool, struct perf_inject, tool);
        int err;

        if (is_anon_memory(filename) || flags & MAP_HUGETLB)
                return 0;
        if (is_no_dso_memory(filename))
                return 0;

        if (inject->known_build_ids != NULL &&
            perf_inject__lookup_known_build_id(inject, dso))
                return 1;

        if (dso__read_build_id(dso) < 0) {
                pr_debug("no build_id found for %s\n", filename);
                return -1;
        }

        err = perf_event__synthesize_build_id(tool, sample, machine,
                                              perf_event__repipe,
                                              evsel, misc, dso__bid(dso),
                                              filename);
        if (err) {
                pr_err("Can't synthesize build_id event for %s\n", filename);
                return -1;
        }

        return 0;
}

static int tool__inject_mmap2_build_id(const struct perf_tool *tool,
                                       struct perf_sample *sample,
                                       struct machine *machine,
                                       const struct evsel *evsel,
                                       __u16 misc,
                                       __u32 pid, __u32 tid,
                                       __u64 start, __u64 len, __u64 pgoff,
                                       struct dso *dso,
                                       __u32 prot, __u32 flags,
                                       const char *filename)
{
        int err;

        /* Return to repipe anonymous maps. */
        if (is_anon_memory(filename) || flags & MAP_HUGETLB)
                return 1;
        if (is_no_dso_memory(filename))
                return 1;

        if (dso__read_build_id(dso)) {
                pr_debug("no build_id found for %s\n", filename);
                return -1;
        }

        err = perf_event__synthesize_mmap2_build_id(tool, sample, machine,
                                                    perf_event__repipe,
                                                    evsel,
                                                    misc, pid, tid,
                                                    start, len, pgoff,
                                                    dso__bid(dso),
                                                    prot, flags,
                                                    filename);
        if (err) {
                pr_err("Can't synthesize build_id event for %s\n", filename);
                return -1;
        }
        return 0;
}

static int mark_dso_hit(const struct perf_inject *inject,
                        const struct perf_tool *tool,
                        struct perf_sample *sample,
                        struct machine *machine,
                        const struct evsel *mmap_evsel,
                        struct map *map, bool sample_in_dso)
{
        struct dso *dso;
        u16 misc = sample->cpumode;

        if (!map)
                return 0;

        if (!sample_in_dso) {
                u16 guest_mask = PERF_RECORD_MISC_GUEST_KERNEL |
                        PERF_RECORD_MISC_GUEST_USER;

                if ((misc & guest_mask) != 0) {
                        misc &= PERF_RECORD_MISC_HYPERVISOR;
                        misc |= __map__is_kernel(map)
                                ? PERF_RECORD_MISC_GUEST_KERNEL
                                : PERF_RECORD_MISC_GUEST_USER;
                } else {
                        misc &= PERF_RECORD_MISC_HYPERVISOR;
                        misc |= __map__is_kernel(map)
                                ? PERF_RECORD_MISC_KERNEL
                                : PERF_RECORD_MISC_USER;
                }
        }
        dso = map__dso(map);
        if (inject->build_id_style == BID_RWS__INJECT_HEADER_LAZY) {
                if (dso && !dso__hit(dso)) {
                        dso__set_hit(dso);
                        tool__inject_build_id(tool, sample, machine,
                                             mmap_evsel, misc, dso__long_name(dso), dso,
                                             map__flags(map));
                }
        } else if (inject->build_id_style == BID_RWS__MMAP2_BUILDID_LAZY) {
                if (!map__hit(map)) {
                        const struct build_id null_bid = { .size = 0 };
                        const struct build_id *bid = dso ? dso__bid(dso) : &null_bid;
                        const char *filename = dso ? dso__long_name(dso) : "";

                        map__set_hit(map);
                        perf_event__synthesize_mmap2_build_id(tool, sample, machine,
                                                                perf_event__repipe,
                                                                mmap_evsel,
                                                                misc,
                                                                sample->pid, sample->tid,
                                                                map__start(map),
                                                                map__end(map) - map__start(map),
                                                                map__pgoff(map),
                                                                bid,
                                                                map__prot(map),
                                                                map__flags(map),
                                                                filename);
                }
        }
        return 0;
}

struct mark_dso_hit_args {
        const struct perf_inject *inject;
        const struct perf_tool *tool;
        struct perf_sample *sample;
        struct machine *machine;
        const struct evsel *mmap_evsel;
};

static int mark_dso_hit_callback(struct callchain_cursor_node *node, void *data)
{
        struct mark_dso_hit_args *args = data;
        struct map *map = node->ms.map;

        return mark_dso_hit(args->inject, args->tool, args->sample, args->machine,
                            args->mmap_evsel, map, /*sample_in_dso=*/false);
}

int perf_event__inject_buildid(const struct perf_tool *tool, union perf_event *event,
                               struct perf_sample *sample,
                               struct evsel *evsel __maybe_unused,
                               struct machine *machine)
{
        struct addr_location al;
        struct thread *thread;
        struct perf_inject *inject = container_of(tool, struct perf_inject, tool);
        struct mark_dso_hit_args args = {
                .inject = inject,
                .tool = tool,
                /*
                 * Use the parsed sample data of the sample event, which will
                 * have a later timestamp than the mmap event.
                 */
                .sample = sample,
                .machine = machine,
                .mmap_evsel = inject__mmap_evsel(inject),
        };

        addr_location__init(&al);
        thread = machine__findnew_thread(machine, sample->pid, sample->tid);
        if (thread == NULL) {
                pr_err("problem processing %d event, skipping it.\n",
                       event->header.type);
                goto repipe;
        }

        if (thread__find_map(thread, sample->cpumode, sample->ip, &al)) {
                mark_dso_hit(inject, tool, sample, machine, args.mmap_evsel, al.map,
                             /*sample_in_dso=*/true);
        }

        sample__for_each_callchain_node(thread, evsel, sample, PERF_MAX_STACK_DEPTH,
                                        /*symbols=*/false, mark_dso_hit_callback, &args);

        thread__put(thread);
repipe:
        perf_event__repipe(tool, event, sample, machine);
        addr_location__exit(&al);
        return 0;
}

static int perf_inject__sched_process_exit(const struct perf_tool *tool,
                                           union perf_event *event __maybe_unused,
                                           struct perf_sample *sample,
                                           struct evsel *evsel __maybe_unused,
                                           struct machine *machine __maybe_unused)
{
        struct perf_inject *inject = container_of(tool, struct perf_inject, tool);
        struct event_entry *ent;

        list_for_each_entry(ent, &inject->samples, node) {
                if (sample->tid == ent->tid) {
                        list_del_init(&ent->node);
                        free(ent);
                        break;
                }
        }

        return 0;
}

static int perf_inject__sched_switch(const struct perf_tool *tool,
                                     union perf_event *event,
                                     struct perf_sample *sample,
                                     struct evsel *evsel,
                                     struct machine *machine)
{
        struct perf_inject *inject = container_of(tool, struct perf_inject, tool);
        struct event_entry *ent;

        perf_inject__sched_process_exit(tool, event, sample, evsel, machine);

        ent = malloc(event->header.size + sizeof(struct event_entry));
        if (ent == NULL) {
                color_fprintf(stderr, PERF_COLOR_RED,
                             "Not enough memory to process sched switch event!");
                return -1;
        }

        ent->tid = sample->tid;
        memcpy(&ent->event, event, event->header.size);
        list_add(&ent->node, &inject->samples);
        return 0;
}

#ifdef HAVE_LIBTRACEEVENT
static int perf_inject__sched_stat(const struct perf_tool *tool,
                                   union perf_event *event __maybe_unused,
                                   struct perf_sample *sample,
                                   struct evsel *evsel,
                                   struct machine *machine)
{
        struct event_entry *ent;
        union perf_event *event_sw;
        struct perf_sample sample_sw;
        struct perf_inject *inject = container_of(tool, struct perf_inject, tool);
        u32 pid = evsel__intval(evsel, sample, "pid");

        list_for_each_entry(ent, &inject->samples, node) {
                if (pid == ent->tid)
                        goto found;
        }

        return 0;
found:
        event_sw = &ent->event[0];
        evsel__parse_sample(evsel, event_sw, &sample_sw);

        sample_sw.period = sample->period;
        sample_sw.time   = sample->time;
        perf_event__synthesize_sample(event_sw, evsel->core.attr.sample_type,
                                      evsel->core.attr.read_format, &sample_sw);
        build_id__mark_dso_hit(tool, event_sw, &sample_sw, evsel, machine);
        return perf_event__repipe(tool, event_sw, &sample_sw, machine);
}
#endif

static struct guest_vcpu *guest_session__vcpu(struct guest_session *gs, u32 vcpu)
{
        if (realloc_array_as_needed(gs->vcpu, gs->vcpu_cnt, vcpu, NULL))
                return NULL;
        return &gs->vcpu[vcpu];
}

static int guest_session__output_bytes(struct guest_session *gs, void *buf, size_t sz)
{
        ssize_t ret = writen(gs->tmp_fd, buf, sz);

        return ret < 0 ? ret : 0;
}

static int guest_session__repipe(const struct perf_tool *tool,
                                 union perf_event *event,
                                 struct perf_sample *sample __maybe_unused,
                                 struct machine *machine __maybe_unused)
{
        struct guest_session *gs = container_of(tool, struct guest_session, tool);

        return guest_session__output_bytes(gs, event, event->header.size);
}

static int guest_session__map_tid(struct guest_session *gs, u32 tid, u32 vcpu)
{
        struct guest_tid *guest_tid = zalloc(sizeof(*guest_tid));
        int hash;

        if (!guest_tid)
                return -ENOMEM;

        guest_tid->tid = tid;
        guest_tid->vcpu = vcpu;
        hash = hash_32(guest_tid->tid, PERF_EVLIST__HLIST_BITS);
        hlist_add_head(&guest_tid->node, &gs->tids[hash]);

        return 0;
}

static int host_peek_vm_comms_cb(struct perf_session *session __maybe_unused,
                                 union perf_event *event,
                                 u64 offset __maybe_unused, void *data)
{
        struct guest_session *gs = data;
        unsigned int vcpu;
        struct guest_vcpu *guest_vcpu;
        int ret;

        if (event->header.type != PERF_RECORD_COMM ||
            event->comm.pid != gs->machine_pid)
                return 0;

        /*
         * QEMU option -name debug-threads=on, causes thread names formatted as
         * below, although it is not an ABI. Also libvirt seems to use this by
         * default. Here we rely on it to tell us which thread is which VCPU.
         */
        ret = sscanf(event->comm.comm, "CPU %u/KVM", &vcpu);
        if (ret <= 0)
                return ret;
        pr_debug("Found VCPU: tid %u comm %s vcpu %u\n",
                 event->comm.tid, event->comm.comm, vcpu);
        if (vcpu > INT_MAX) {
                pr_err("Invalid VCPU %u\n", vcpu);
                return -EINVAL;
        }
        guest_vcpu = guest_session__vcpu(gs, vcpu);
        if (!guest_vcpu)
                return -ENOMEM;
        if (guest_vcpu->tid && guest_vcpu->tid != event->comm.tid) {
                pr_err("Fatal error: Two threads found with the same VCPU\n");
                return -EINVAL;
        }
        guest_vcpu->tid = event->comm.tid;

        return guest_session__map_tid(gs, event->comm.tid, vcpu);
}

static int host_peek_vm_comms(struct perf_session *session, struct guest_session *gs)
{
        return perf_session__peek_events(session, session->header.data_offset,
                                         session->header.data_size,
                                         host_peek_vm_comms_cb, gs);
}

static bool evlist__is_id_used(struct evlist *evlist, u64 id)
{
        return evlist__id2sid(evlist, id);
}

static u64 guest_session__allocate_new_id(struct guest_session *gs, struct evlist *host_evlist)
{
        do {
                gs->highest_id += 1;
        } while (!gs->highest_id || evlist__is_id_used(host_evlist, gs->highest_id));

        return gs->highest_id;
}

static int guest_session__map_id(struct guest_session *gs, u64 id, u64 host_id, u32 vcpu)
{
        struct guest_id *guest_id = zalloc(sizeof(*guest_id));
        int hash;

        if (!guest_id)
                return -ENOMEM;

        guest_id->id = id;
        guest_id->host_id = host_id;
        guest_id->vcpu = vcpu;
        hash = hash_64(guest_id->id, PERF_EVLIST__HLIST_BITS);
        hlist_add_head(&guest_id->node, &gs->heads[hash]);

        return 0;
}

static u64 evlist__find_highest_id(struct evlist *evlist)
{
        struct evsel *evsel;
        u64 highest_id = 1;

        evlist__for_each_entry(evlist, evsel) {
                u32 j;

                for (j = 0; j < evsel->core.ids; j++) {
                        u64 id = evsel->core.id[j];

                        if (id > highest_id)
                                highest_id = id;
                }
        }

        return highest_id;
}

static int guest_session__map_ids(struct guest_session *gs, struct evlist *host_evlist)
{
        struct evlist *evlist = gs->session->evlist;
        struct evsel *evsel;
        int ret;

        evlist__for_each_entry(evlist, evsel) {
                u32 j;

                for (j = 0; j < evsel->core.ids; j++) {
                        struct perf_sample_id *sid;
                        u64 host_id;
                        u64 id;

                        id = evsel->core.id[j];
                        sid = evlist__id2sid(evlist, id);
                        if (!sid || sid->cpu.cpu == -1)
                                continue;
                        host_id = guest_session__allocate_new_id(gs, host_evlist);
                        ret = guest_session__map_id(gs, id, host_id, sid->cpu.cpu);
                        if (ret)
                                return ret;
                }
        }

        return 0;
}

static struct guest_id *guest_session__lookup_id(struct guest_session *gs, u64 id)
{
        struct hlist_head *head;
        struct guest_id *guest_id;
        int hash;

        hash = hash_64(id, PERF_EVLIST__HLIST_BITS);
        head = &gs->heads[hash];

        hlist_for_each_entry(guest_id, head, node)
                if (guest_id->id == id)
                        return guest_id;

        return NULL;
}

static int process_attr(const struct perf_tool *tool, union perf_event *event,
                        struct perf_sample *sample __maybe_unused,
                        struct machine *machine __maybe_unused)
{
        struct perf_inject *inject = container_of(tool, struct perf_inject, tool);

        return perf_event__process_attr(tool, event, &inject->session->evlist);
}

static int guest_session__add_attr(struct guest_session *gs, struct evsel *evsel)
{
        struct perf_inject *inject = container_of(gs, struct perf_inject, guest_session);
        struct perf_event_attr attr = evsel->core.attr;
        u64 *id_array;
        u32 *vcpu_array;
        int ret = -ENOMEM;
        u32 i;

        id_array = calloc(evsel->core.ids, sizeof(*id_array));
        if (!id_array)
                return -ENOMEM;

        vcpu_array = calloc(evsel->core.ids, sizeof(*vcpu_array));
        if (!vcpu_array)
                goto out;

        for (i = 0; i < evsel->core.ids; i++) {
                u64 id = evsel->core.id[i];
                struct guest_id *guest_id = guest_session__lookup_id(gs, id);

                if (!guest_id) {
                        pr_err("Failed to find guest id %"PRIu64"\n", id);
                        ret = -EINVAL;
                        goto out;
                }
                id_array[i] = guest_id->host_id;
                vcpu_array[i] = guest_id->vcpu;
        }

        attr.sample_type |= PERF_SAMPLE_IDENTIFIER;
        attr.exclude_host = 1;
        attr.exclude_guest = 0;

        ret = perf_event__synthesize_attr(&inject->tool, &attr, evsel->core.ids,
                                          id_array, process_attr);
        if (ret)
                pr_err("Failed to add guest attr.\n");

        for (i = 0; i < evsel->core.ids; i++) {
                struct perf_sample_id *sid;
                u32 vcpu = vcpu_array[i];

                sid = evlist__id2sid(inject->session->evlist, id_array[i]);
                /* Guest event is per-thread from the host point of view */
                sid->cpu.cpu = -1;
                sid->tid = gs->vcpu[vcpu].tid;
                sid->machine_pid = gs->machine_pid;
                sid->vcpu.cpu = vcpu;
        }
out:
        free(vcpu_array);
        free(id_array);
        return ret;
}

static int guest_session__add_attrs(struct guest_session *gs)
{
        struct evlist *evlist = gs->session->evlist;
        struct evsel *evsel;
        int ret;

        evlist__for_each_entry(evlist, evsel) {
                ret = guest_session__add_attr(gs, evsel);
                if (ret)
                        return ret;
        }

        return 0;
}

static int synthesize_id_index(struct perf_inject *inject, size_t new_cnt)
{
        struct perf_session *session = inject->session;
        struct evlist *evlist = session->evlist;
        struct machine *machine = &session->machines.host;
        size_t from = evlist->core.nr_entries - new_cnt;

        return __perf_event__synthesize_id_index(&inject->tool, perf_event__repipe,
                                                 evlist, machine, from);
}

static struct guest_tid *guest_session__lookup_tid(struct guest_session *gs, u32 tid)
{
        struct hlist_head *head;
        struct guest_tid *guest_tid;
        int hash;

        hash = hash_32(tid, PERF_EVLIST__HLIST_BITS);
        head = &gs->tids[hash];

        hlist_for_each_entry(guest_tid, head, node)
                if (guest_tid->tid == tid)
                        return guest_tid;

        return NULL;
}

static bool dso__is_in_kernel_space(struct dso *dso)
{
        if (dso__is_vdso(dso))
                return false;

        return dso__is_kcore(dso) ||
               dso__kernel(dso) ||
               is_kernel_module(dso__long_name(dso), PERF_RECORD_MISC_CPUMODE_UNKNOWN);
}

static u64 evlist__first_id(struct evlist *evlist)
{
        struct evsel *evsel;

        evlist__for_each_entry(evlist, evsel) {
                if (evsel->core.ids)
                        return evsel->core.id[0];
        }
        return 0;
}

static int process_build_id(const struct perf_tool *tool,
                            union perf_event *event,
                            struct perf_sample *sample __maybe_unused,
                            struct machine *machine __maybe_unused)
{
        struct perf_inject *inject = container_of(tool, struct perf_inject, tool);

        return perf_event__process_build_id(tool, inject->session, event);
}

static int synthesize_build_id(struct perf_inject *inject, struct dso *dso, pid_t machine_pid)
{
        struct machine *machine = perf_session__findnew_machine(inject->session, machine_pid);
        struct perf_sample synth_sample = {
                .pid       = -1,
                .tid       = -1,
                .time      = -1,
                .stream_id = -1,
                .cpu       = -1,
                .period    = 1,
                .cpumode   = dso__is_in_kernel_space(dso)
                ? PERF_RECORD_MISC_GUEST_KERNEL
                : PERF_RECORD_MISC_GUEST_USER,
        };

        if (!machine)
                return -ENOMEM;

        dso__set_hit(dso);

        return perf_event__synthesize_build_id(&inject->tool, &synth_sample, machine,
                                               process_build_id, inject__mmap_evsel(inject),
                                               /*misc=*/synth_sample.cpumode,
                                               dso__bid(dso), dso__long_name(dso));
}

static int guest_session__add_build_ids_cb(struct dso *dso, void *data)
{
        struct guest_session *gs = data;
        struct perf_inject *inject = container_of(gs, struct perf_inject, guest_session);

        if (!dso__has_build_id(dso))
                return 0;

        return synthesize_build_id(inject, dso, gs->machine_pid);

}

static int guest_session__add_build_ids(struct guest_session *gs)
{
        struct perf_inject *inject = container_of(gs, struct perf_inject, guest_session);

        /* Build IDs will be put in the Build ID feature section */
        perf_header__set_feat(&inject->session->header, HEADER_BUILD_ID);

        return dsos__for_each_dso(&gs->session->machines.host.dsos,
                                  guest_session__add_build_ids_cb,
                                  gs);
}

static int guest_session__ksymbol_event(const struct perf_tool *tool,
                                        union perf_event *event,
                                        struct perf_sample *sample __maybe_unused,
                                        struct machine *machine __maybe_unused)
{
        struct guest_session *gs = container_of(tool, struct guest_session, tool);

        /* Only support out-of-line i.e. no BPF support */
        if (event->ksymbol.ksym_type != PERF_RECORD_KSYMBOL_TYPE_OOL)
                return 0;

        return guest_session__output_bytes(gs, event, event->header.size);
}

static int guest_session__start(struct guest_session *gs, const char *name, bool force)
{
        char tmp_file_name[] = "/tmp/perf-inject-guest_session-XXXXXX";
        struct perf_session *session;
        int ret;

        /* Only these events will be injected */
        gs->tool.mmap           = guest_session__repipe;
        gs->tool.mmap2          = guest_session__repipe;
        gs->tool.comm           = guest_session__repipe;
        gs->tool.fork           = guest_session__repipe;
        gs->tool.exit           = guest_session__repipe;
        gs->tool.lost           = guest_session__repipe;
        gs->tool.context_switch = guest_session__repipe;
        gs->tool.ksymbol        = guest_session__ksymbol_event;
        gs->tool.text_poke      = guest_session__repipe;
        /*
         * Processing a build ID creates a struct dso with that build ID. Later,
         * all guest dsos are iterated and the build IDs processed into the host
         * session where they will be output to the Build ID feature section
         * when the perf.data file header is written.
         */
        gs->tool.build_id       = perf_event__process_build_id;
        /* Process the id index to know what VCPU an ID belongs to */
        gs->tool.id_index       = perf_event__process_id_index;

        gs->tool.ordered_events = true;
        gs->tool.ordering_requires_timestamps = true;

        gs->data.path   = name;
        gs->data.force  = force;
        gs->data.mode   = PERF_DATA_MODE_READ;

        session = perf_session__new(&gs->data, &gs->tool);
        if (IS_ERR(session))
                return PTR_ERR(session);
        gs->session = session;

        /*
         * Initial events have zero'd ID samples. Get default ID sample size
         * used for removing them.
         */
        gs->dflt_id_hdr_size = session->machines.host.id_hdr_size;
        /* And default ID for adding back a host-compatible ID sample */
        gs->dflt_id = evlist__first_id(session->evlist);
        if (!gs->dflt_id) {
                pr_err("Guest data has no sample IDs");
                return -EINVAL;
        }

        /* Temporary file for guest events */
        gs->tmp_file_name = strdup(tmp_file_name);
        if (!gs->tmp_file_name)
                return -ENOMEM;
        gs->tmp_fd = mkstemp(gs->tmp_file_name);
        if (gs->tmp_fd < 0)
                return -errno;

        if (zstd_init(&gs->session->zstd_data, 0) < 0)
                pr_warning("Guest session decompression initialization failed.\n");

        /*
         * perf does not support processing 2 sessions simultaneously, so output
         * guest events to a temporary file.
         */
        ret = perf_session__process_events(gs->session);
        if (ret)
                return ret;

        if (lseek(gs->tmp_fd, 0, SEEK_SET))
                return -errno;

        return 0;
}

/* Free hlist nodes assuming hlist_node is the first member of hlist entries */
static void free_hlist(struct hlist_head *heads, size_t hlist_sz)
{
        struct hlist_node *pos, *n;
        size_t i;

        for (i = 0; i < hlist_sz; ++i) {
                hlist_for_each_safe(pos, n, &heads[i]) {
                        hlist_del(pos);
                        free(pos);
                }
        }
}

static void guest_session__exit(struct guest_session *gs)
{
        if (gs->session) {
                perf_session__delete(gs->session);
                free_hlist(gs->heads, PERF_EVLIST__HLIST_SIZE);
                free_hlist(gs->tids, PERF_EVLIST__HLIST_SIZE);
        }
        if (gs->tmp_file_name) {
                if (gs->tmp_fd >= 0)
                        close(gs->tmp_fd);
                unlink(gs->tmp_file_name);
                zfree(&gs->tmp_file_name);
        }
        zfree(&gs->vcpu);
        zfree(&gs->perf_data_file);
}

static void get_tsc_conv(struct perf_tsc_conversion *tc, struct perf_record_time_conv *time_conv)
{
        tc->time_shift          = time_conv->time_shift;
        tc->time_mult           = time_conv->time_mult;
        tc->time_zero           = time_conv->time_zero;
        tc->time_cycles         = time_conv->time_cycles;
        tc->time_mask           = time_conv->time_mask;
        tc->cap_user_time_zero  = time_conv->cap_user_time_zero;
        tc->cap_user_time_short = time_conv->cap_user_time_short;
}

static void guest_session__get_tc(struct guest_session *gs)
{
        struct perf_inject *inject = container_of(gs, struct perf_inject, guest_session);

        get_tsc_conv(&gs->host_tc, &inject->session->time_conv);
        get_tsc_conv(&gs->guest_tc, &gs->session->time_conv);
}

static void guest_session__convert_time(struct guest_session *gs, u64 guest_time, u64 *host_time)
{
        u64 tsc;

        if (!guest_time) {
                *host_time = 0;
                return;
        }

        if (gs->guest_tc.cap_user_time_zero)
                tsc = perf_time_to_tsc(guest_time, &gs->guest_tc);
        else
                tsc = guest_time;

        /*
         * This is the correct order of operations for x86 if the TSC Offset and
         * Multiplier values are used.
         */
        tsc -= gs->time_offset;
        tsc /= gs->time_scale;

        if (gs->host_tc.cap_user_time_zero)
                *host_time = tsc_to_perf_time(tsc, &gs->host_tc);
        else
                *host_time = tsc;
}

static int guest_session__fetch(struct guest_session *gs)
{
        void *buf;
        struct perf_event_header *hdr;
        size_t hdr_sz = sizeof(*hdr);
        ssize_t ret;

        buf = gs->ev.event_buf;
        if (!buf) {
                buf = malloc(PERF_SAMPLE_MAX_SIZE);
                if (!buf)
                        return -ENOMEM;
                gs->ev.event_buf = buf;
        }
        hdr = buf;
        ret = readn(gs->tmp_fd, buf, hdr_sz);
        if (ret < 0)
                return ret;

        if (!ret) {
                /* Zero size means EOF */
                hdr->size = 0;
                return 0;
        }

        buf += hdr_sz;

        ret = readn(gs->tmp_fd, buf, hdr->size - hdr_sz);
        if (ret < 0)
                return ret;

        gs->ev.event = (union perf_event *)gs->ev.event_buf;
        gs->ev.sample.time = 0;

        if (hdr->type >= PERF_RECORD_USER_TYPE_START) {
                pr_err("Unexpected type fetching guest event");
                return 0;
        }

        ret = evlist__parse_sample(gs->session->evlist, gs->ev.event, &gs->ev.sample);
        if (ret) {
                pr_err("Parse failed fetching guest event");
                return ret;
        }

        if (!gs->have_tc) {
                guest_session__get_tc(gs);
                gs->have_tc = true;
        }

        guest_session__convert_time(gs, gs->ev.sample.time, &gs->ev.sample.time);

        return 0;
}

static int evlist__append_id_sample(struct evlist *evlist, union perf_event *ev,
                                    const struct perf_sample *sample)
{
        struct evsel *evsel;
        void *array;
        int ret;

        evsel = evlist__id2evsel(evlist, sample->id);
        array = ev;

        if (!evsel) {
                pr_err("No evsel for id %"PRIu64"\n", sample->id);
                return -EINVAL;
        }

        array += ev->header.size;
        ret = perf_event__synthesize_id_sample(array, evsel->core.attr.sample_type, sample);
        if (ret < 0)
                return ret;

        if (ret & 7) {
                pr_err("Bad id sample size %d\n", ret);
                return -EINVAL;
        }

        ev->header.size += ret;

        return 0;
}

static int guest_session__inject_events(struct guest_session *gs, u64 timestamp)
{
        struct perf_inject *inject = container_of(gs, struct perf_inject, guest_session);
        int ret;

        if (!gs->ready)
                return 0;

        while (1) {
                struct perf_sample *sample;
                struct guest_id *guest_id;
                union perf_event *ev;
                u16 id_hdr_size;
                u8 cpumode;
                u64 id;

                if (!gs->fetched) {
                        ret = guest_session__fetch(gs);
                        if (ret)
                                return ret;
                        gs->fetched = true;
                }

                ev = gs->ev.event;
                sample = &gs->ev.sample;

                if (!ev->header.size)
                        return 0; /* EOF */

                if (sample->time > timestamp)
                        return 0;

                /* Change cpumode to guest */
                cpumode = ev->header.misc & PERF_RECORD_MISC_CPUMODE_MASK;
                if (cpumode & PERF_RECORD_MISC_USER)
                        cpumode = PERF_RECORD_MISC_GUEST_USER;
                else
                        cpumode = PERF_RECORD_MISC_GUEST_KERNEL;
                ev->header.misc &= ~PERF_RECORD_MISC_CPUMODE_MASK;
                ev->header.misc |= cpumode;

                id = sample->id;
                if (!id) {
                        id = gs->dflt_id;
                        id_hdr_size = gs->dflt_id_hdr_size;
                } else {
                        struct evsel *evsel = evlist__id2evsel(gs->session->evlist, id);

                        id_hdr_size = evsel__id_hdr_size(evsel);
                }

                if (id_hdr_size & 7) {
                        pr_err("Bad id_hdr_size %u\n", id_hdr_size);
                        return -EINVAL;
                }

                if (ev->header.size & 7) {
                        pr_err("Bad event size %u\n", ev->header.size);
                        return -EINVAL;
                }

                /* Remove guest id sample */
                ev->header.size -= id_hdr_size;

                if (ev->header.size & 7) {
                        pr_err("Bad raw event size %u\n", ev->header.size);
                        return -EINVAL;
                }

                guest_id = guest_session__lookup_id(gs, id);
                if (!guest_id) {
                        pr_err("Guest event with unknown id %llu\n",
                               (unsigned long long)id);
                        return -EINVAL;
                }

                /* Change to host ID to avoid conflicting ID values */
                sample->id = guest_id->host_id;
                sample->stream_id = guest_id->host_id;

                if (sample->cpu != (u32)-1) {
                        if (sample->cpu >= gs->vcpu_cnt) {
                                pr_err("Guest event with unknown VCPU %u\n",
                                       sample->cpu);
                                return -EINVAL;
                        }
                        /* Change to host CPU instead of guest VCPU */
                        sample->cpu = gs->vcpu[sample->cpu].cpu;
                }

                /* New id sample with new ID and CPU */
                ret = evlist__append_id_sample(inject->session->evlist, ev, sample);
                if (ret)
                        return ret;

                if (ev->header.size & 7) {
                        pr_err("Bad new event size %u\n", ev->header.size);
                        return -EINVAL;
                }

                gs->fetched = false;

                ret = output_bytes(inject, ev, ev->header.size);
                if (ret)
                        return ret;
        }
}

static int guest_session__flush_events(struct guest_session *gs)
{
        return guest_session__inject_events(gs, -1);
}

static int host__repipe(const struct perf_tool *tool,
                        union perf_event *event,
                        struct perf_sample *sample,
                        struct machine *machine)
{
        struct perf_inject *inject = container_of(tool, struct perf_inject, tool);
        int ret;

        ret = guest_session__inject_events(&inject->guest_session, sample->time);
        if (ret)
                return ret;

        return perf_event__repipe(tool, event, sample, machine);
}

static int host__finished_init(const struct perf_tool *tool, struct perf_session *session,
                               union perf_event *event)
{
        struct perf_inject *inject = container_of(tool, struct perf_inject, tool);
        struct guest_session *gs = &inject->guest_session;
        int ret;

        /*
         * Peek through host COMM events to find QEMU threads and the VCPU they
         * are running.
         */
        ret = host_peek_vm_comms(session, gs);
        if (ret)
                return ret;

        if (!gs->vcpu_cnt) {
                pr_err("No VCPU threads found for pid %u\n", gs->machine_pid);
                return -EINVAL;
        }

        /*
         * Allocate new (unused) host sample IDs and map them to the guest IDs.
         */
        gs->highest_id = evlist__find_highest_id(session->evlist);
        ret = guest_session__map_ids(gs, session->evlist);
        if (ret)
                return ret;

        ret = guest_session__add_attrs(gs);
        if (ret)
                return ret;

        ret = synthesize_id_index(inject, gs->session->evlist->core.nr_entries);
        if (ret) {
                pr_err("Failed to synthesize id_index\n");
                return ret;
        }

        ret = guest_session__add_build_ids(gs);
        if (ret) {
                pr_err("Failed to add guest build IDs\n");
                return ret;
        }

        gs->ready = true;

        ret = guest_session__inject_events(gs, 0);
        if (ret)
                return ret;

        return perf_event__repipe_op2_synth(tool, session, event);
}

/*
 * Obey finished-round ordering. The FINISHED_ROUND event is first processed
 * which flushes host events to file up until the last flush time. Then inject
 * guest events up to the same time. Finally write out the FINISHED_ROUND event
 * itself.
 */
static int host__finished_round(const struct perf_tool *tool,
                                union perf_event *event,
                                struct ordered_events *oe)
{
        struct perf_inject *inject = container_of(tool, struct perf_inject, tool);
        int ret = perf_event__process_finished_round(tool, event, oe);
        u64 timestamp = ordered_events__last_flush_time(oe);

        if (ret)
                return ret;

        ret = guest_session__inject_events(&inject->guest_session, timestamp);
        if (ret)
                return ret;

        return perf_event__repipe_oe_synth(tool, event, oe);
}

static int host__context_switch(const struct perf_tool *tool,
                                union perf_event *event,
                                struct perf_sample *sample,
                                struct machine *machine)
{
        struct perf_inject *inject = container_of(tool, struct perf_inject, tool);
        bool out = event->header.misc & PERF_RECORD_MISC_SWITCH_OUT;
        struct guest_session *gs = &inject->guest_session;
        u32 pid = event->context_switch.next_prev_pid;
        u32 tid = event->context_switch.next_prev_tid;
        struct guest_tid *guest_tid;
        u32 vcpu;

        if (out || pid != gs->machine_pid)
                goto out;

        guest_tid = guest_session__lookup_tid(gs, tid);
        if (!guest_tid)
                goto out;

        if (sample->cpu == (u32)-1) {
                pr_err("Switch event does not have CPU\n");
                return -EINVAL;
        }

        vcpu = guest_tid->vcpu;
        if (vcpu >= gs->vcpu_cnt)
                return -EINVAL;

        /* Guest is switching in, record which CPU the VCPU is now running on */
        gs->vcpu[vcpu].cpu = sample->cpu;
out:
        return host__repipe(tool, event, sample, machine);
}

static void sig_handler(int sig __maybe_unused)
{
        session_done = 1;
}

static int evsel__check_stype(struct evsel *evsel, u64 sample_type, const char *sample_msg)
{
        struct perf_event_attr *attr = &evsel->core.attr;
        const char *name = evsel__name(evsel);

        if (!(attr->sample_type & sample_type)) {
                pr_err("Samples for %s event do not have %s attribute set.",
                        name, sample_msg);
                return -EINVAL;
        }

        return 0;
}

static int drop_sample(const struct perf_tool *tool __maybe_unused,
                       union perf_event *event __maybe_unused,
                       struct perf_sample *sample __maybe_unused,
                       struct evsel *evsel __maybe_unused,
                       struct machine *machine __maybe_unused)
{
        return 0;
}

static void strip_init(struct perf_inject *inject)
{
        struct evlist *evlist = inject->session->evlist;
        struct evsel *evsel;

        inject->tool.context_switch = perf_event__drop;

        evlist__for_each_entry(evlist, evsel)
                evsel->handler = drop_sample;
}

static int parse_vm_time_correlation(const struct option *opt, const char *str, int unset)
{
        struct perf_inject *inject = opt->value;
        const char *args;
        char *dry_run;

        if (unset)
                return 0;

        inject->itrace_synth_opts.set = true;
        inject->itrace_synth_opts.vm_time_correlation = true;
        inject->in_place_update = true;

        if (!str)
                return 0;

        dry_run = skip_spaces(str);
        if (!strncmp(dry_run, "dry-run", strlen("dry-run"))) {
                inject->itrace_synth_opts.vm_tm_corr_dry_run = true;
                inject->in_place_update_dry_run = true;
                args = dry_run + strlen("dry-run");
        } else {
                args = str;
        }

        inject->itrace_synth_opts.vm_tm_corr_args = strdup(args);

        return inject->itrace_synth_opts.vm_tm_corr_args ? 0 : -ENOMEM;
}

static int parse_guest_data(const struct option *opt, const char *str, int unset)
{
        struct perf_inject *inject = opt->value;
        struct guest_session *gs = &inject->guest_session;
        char *tok;
        char *s;

        if (unset)
                return 0;

        if (!str)
                goto bad_args;

        s = strdup(str);
        if (!s)
                return -ENOMEM;

        gs->perf_data_file = strsep(&s, ",");
        if (!gs->perf_data_file)
                goto bad_args;

        gs->copy_kcore_dir = has_kcore_dir(gs->perf_data_file);
        if (gs->copy_kcore_dir)
                inject->output.is_dir = true;

        tok = strsep(&s, ",");
        if (!tok)
                goto bad_args;
        gs->machine_pid = strtoul(tok, NULL, 0);
        if (!inject->guest_session.machine_pid)
                goto bad_args;

        gs->time_scale = 1;

        tok = strsep(&s, ",");
        if (!tok)
                goto out;
        gs->time_offset = strtoull(tok, NULL, 0);

        tok = strsep(&s, ",");
        if (!tok)
                goto out;
        gs->time_scale = strtod(tok, NULL);
        if (!gs->time_scale)
                goto bad_args;
out:
        return 0;

bad_args:
        pr_err("--guest-data option requires guest perf.data file name, "
               "guest machine PID, and optionally guest timestamp offset, "
               "and guest timestamp scale factor, separated by commas.\n");
        return -1;
}

static int save_section_info_cb(struct perf_file_section *section,
                                struct perf_header *ph __maybe_unused,
                                int feat, int fd __maybe_unused, void *data)
{
        struct perf_inject *inject = data;

        inject->secs[feat] = *section;
        return 0;
}

static int save_section_info(struct perf_inject *inject)
{
        struct perf_header *header = &inject->session->header;
        int fd = perf_data__fd(inject->session->data);

        return perf_header__process_sections(header, fd, inject, save_section_info_cb);
}

static bool keep_feat(struct perf_inject *inject, int feat)
{
        switch (feat) {
        /* Keep original information that describes the machine or software */
        case HEADER_TRACING_DATA:
        case HEADER_HOSTNAME:
        case HEADER_OSRELEASE:
        case HEADER_VERSION:
        case HEADER_ARCH:
        case HEADER_NRCPUS:
        case HEADER_CPUDESC:
        case HEADER_CPUID:
        case HEADER_TOTAL_MEM:
        case HEADER_CPU_TOPOLOGY:
        case HEADER_NUMA_TOPOLOGY:
        case HEADER_PMU_MAPPINGS:
        case HEADER_CACHE:
        case HEADER_MEM_TOPOLOGY:
        case HEADER_CLOCKID:
        case HEADER_BPF_PROG_INFO:
        case HEADER_BPF_BTF:
        case HEADER_CPU_PMU_CAPS:
        case HEADER_CLOCK_DATA:
        case HEADER_HYBRID_TOPOLOGY:
        case HEADER_PMU_CAPS:
        case HEADER_CPU_DOMAIN_INFO:
                return true;
        /* Information that can be updated */
        case HEADER_BUILD_ID:
                return inject->build_id_style == BID_RWS__NONE;
        case HEADER_CMDLINE:
        case HEADER_EVENT_DESC:
        case HEADER_BRANCH_STACK:
        case HEADER_GROUP_DESC:
        case HEADER_AUXTRACE:
        case HEADER_STAT:
        case HEADER_SAMPLE_TIME:
        case HEADER_DIR_FORMAT:
        case HEADER_COMPRESSED:
        default:
                return false;
        };
}

static int read_file(int fd, u64 offs, void *buf, size_t sz)
{
        ssize_t ret = preadn(fd, buf, sz, offs);

        if (ret < 0)
                return -errno;
        if ((size_t)ret != sz)
                return -EINVAL;
        return 0;
}

static int feat_copy(struct perf_inject *inject, int feat, struct feat_writer *fw)
{
        int fd = perf_data__fd(inject->session->data);
        u64 offs = inject->secs[feat].offset;
        size_t sz = inject->secs[feat].size;
        void *buf = malloc(sz);
        int ret;

        if (!buf)
                return -ENOMEM;

        ret = read_file(fd, offs, buf, sz);
        if (ret)
                goto out_free;

        ret = fw->write(fw, buf, sz);
out_free:
        free(buf);
        return ret;
}

struct inject_fc {
        struct feat_copier fc;
        struct perf_inject *inject;
};

static int feat_copy_cb(struct feat_copier *fc, int feat, struct feat_writer *fw)
{
        struct inject_fc *inj_fc = container_of(fc, struct inject_fc, fc);
        struct perf_inject *inject = inj_fc->inject;
        int ret;

        if (!inject->secs[feat].offset ||
            !keep_feat(inject, feat))
                return 0;

        ret = feat_copy(inject, feat, fw);
        if (ret < 0)
                return ret;

        return 1; /* Feature section copied */
}

static int copy_kcore_dir(struct perf_inject *inject)
{
        char *cmd;
        int ret;

        ret = asprintf(&cmd, "cp -r -n %s/kcore_dir* %s >/dev/null 2>&1",
                       inject->input_name, inject->output.path);
        if (ret < 0)
                return ret;
        pr_debug("%s\n", cmd);
        ret = system(cmd);
        free(cmd);
        return ret;
}

static int guest_session__copy_kcore_dir(struct guest_session *gs)
{
        struct perf_inject *inject = container_of(gs, struct perf_inject, guest_session);
        char *cmd;
        int ret;

        ret = asprintf(&cmd, "cp -r -n %s/kcore_dir %s/kcore_dir__%u >/dev/null 2>&1",
                       gs->perf_data_file, inject->output.path, gs->machine_pid);
        if (ret < 0)
                return ret;
        pr_debug("%s\n", cmd);
        ret = system(cmd);
        free(cmd);
        return ret;
}

static int output_fd(struct perf_inject *inject)
{
        return inject->in_place_update ? -1 : perf_data__fd(&inject->output);
}

static int __cmd_inject(struct perf_inject *inject)
{
        int ret = -EINVAL;
        struct guest_session *gs = &inject->guest_session;
        struct perf_session *session = inject->session;
        int fd = output_fd(inject);
        u64 output_data_offset = perf_session__data_offset(session->evlist);
        /*
         * Pipe input hasn't loaded the attributes and will handle them as
         * events. So that the attributes don't overlap the data, write the
         * attributes after the data.
         */
        bool write_attrs_after_data = !inject->output.is_pipe && inject->session->data->is_pipe;

        signal(SIGINT, sig_handler);

        if (inject->build_id_style != BID_RWS__NONE || inject->sched_stat ||
            inject->itrace_synth_opts.set) {
                inject->tool.mmap         = perf_event__repipe_mmap;
                inject->tool.mmap2        = perf_event__repipe_mmap2;
                inject->tool.fork         = perf_event__repipe_fork;
#ifdef HAVE_LIBTRACEEVENT
                inject->tool.tracing_data = perf_event__repipe_tracing_data;
#endif
        }

        if (inject->build_id_style == BID_RWS__INJECT_HEADER_LAZY ||
            inject->build_id_style == BID_RWS__MMAP2_BUILDID_LAZY) {
                inject->tool.sample = perf_event__inject_buildid;
        } else if (inject->sched_stat) {
                struct evsel *evsel;

                evlist__for_each_entry(session->evlist, evsel) {
                        const char *name = evsel__name(evsel);

                        if (!strcmp(name, "sched:sched_switch")) {
                                if (evsel__check_stype(evsel, PERF_SAMPLE_TID, "TID"))
                                        return -EINVAL;

                                evsel->handler = perf_inject__sched_switch;
                        } else if (!strcmp(name, "sched:sched_process_exit"))
                                evsel->handler = perf_inject__sched_process_exit;
#ifdef HAVE_LIBTRACEEVENT
                        else if (!strncmp(name, "sched:sched_stat_", 17))
                                evsel->handler = perf_inject__sched_stat;
#endif
                }
        } else if (inject->itrace_synth_opts.vm_time_correlation) {
                session->itrace_synth_opts = &inject->itrace_synth_opts;
                memset(&inject->tool, 0, sizeof(inject->tool));
                inject->tool.id_index       = perf_event__process_id_index;
                inject->tool.auxtrace_info  = perf_event__process_auxtrace_info;
                inject->tool.auxtrace       = perf_event__process_auxtrace;
                inject->tool.auxtrace_error = perf_event__process_auxtrace_error;
                inject->tool.ordered_events = true;
                inject->tool.ordering_requires_timestamps = true;
        } else if (inject->itrace_synth_opts.set) {
                session->itrace_synth_opts = &inject->itrace_synth_opts;
                inject->itrace_synth_opts.inject = true;
                inject->tool.comm           = perf_event__repipe_comm;
                inject->tool.namespaces     = perf_event__repipe_namespaces;
                inject->tool.exit           = perf_event__repipe_exit;
                inject->tool.id_index       = perf_event__process_id_index;
                inject->tool.auxtrace_info  = perf_event__process_auxtrace_info;
                inject->tool.auxtrace       = perf_event__process_auxtrace;
                inject->tool.aux            = perf_event__drop_aux;
                inject->tool.itrace_start   = perf_event__drop_aux;
                inject->tool.aux_output_hw_id = perf_event__drop_aux;
                inject->tool.ordered_events = true;
                inject->tool.ordering_requires_timestamps = true;
                /* Allow space in the header for new attributes */
                output_data_offset = roundup(8192 + session->header.data_offset, 4096);
                if (inject->strip)
                        strip_init(inject);
        } else if (gs->perf_data_file) {
                char *name = gs->perf_data_file;

                /*
                 * Not strictly necessary, but keep these events in order wrt
                 * guest events.
                 */
                inject->tool.mmap               = host__repipe;
                inject->tool.mmap2              = host__repipe;
                inject->tool.comm               = host__repipe;
                inject->tool.fork               = host__repipe;
                inject->tool.exit               = host__repipe;
                inject->tool.lost               = host__repipe;
                inject->tool.context_switch     = host__repipe;
                inject->tool.ksymbol            = host__repipe;
                inject->tool.text_poke          = host__repipe;
                /*
                 * Once the host session has initialized, set up sample ID
                 * mapping and feed in guest attrs, build IDs and initial
                 * events.
                 */
                inject->tool.finished_init      = host__finished_init;
                /* Obey finished round ordering */
                inject->tool.finished_round     = host__finished_round;
                /* Keep track of which CPU a VCPU is runnng on */
                inject->tool.context_switch     = host__context_switch;
                /*
                 * Must order events to be able to obey finished round
                 * ordering.
                 */
                inject->tool.ordered_events     = true;
                inject->tool.ordering_requires_timestamps = true;
                /* Set up a separate session to process guest perf.data file */
                ret = guest_session__start(gs, name, session->data->force);
                if (ret) {
                        pr_err("Failed to process %s, error %d\n", name, ret);
                        return ret;
                }
                /* Allow space in the header for guest attributes */
                output_data_offset += gs->session->header.data_offset;
                output_data_offset = roundup(output_data_offset, 4096);
        } else if (inject->convert_callchain) {
                inject->tool.sample     = perf_event__convert_sample_callchain;
                inject->tool.fork       = perf_event__repipe_fork;
                inject->tool.comm       = perf_event__repipe_comm;
                inject->tool.exit       = perf_event__repipe_exit;
                inject->tool.mmap       = perf_event__repipe_mmap;
                inject->tool.mmap2      = perf_event__repipe_mmap2;
                inject->tool.ordered_events = true;
                inject->tool.ordering_requires_timestamps = true;
        }

        if (!inject->itrace_synth_opts.set)
                auxtrace_index__free(&session->auxtrace_index);

        if (!inject->output.is_pipe && !inject->in_place_update)
                lseek(fd, output_data_offset, SEEK_SET);

        ret = perf_session__process_events(session);
        if (ret)
                return ret;

        if (gs->session) {
                /*
                 * Remaining guest events have later timestamps. Flush them
                 * out to file.
                 */
                ret = guest_session__flush_events(gs);
                if (ret) {
                        pr_err("Failed to flush guest events\n");
                        return ret;
                }
        }

        if (!inject->output.is_pipe && !inject->in_place_update) {
                struct inject_fc inj_fc = {
                        .fc.copy = feat_copy_cb,
                        .inject = inject,
                };

                if (inject->build_id_style == BID_RWS__INJECT_HEADER_LAZY ||
                    inject->build_id_style == BID_RWS__INJECT_HEADER_ALL)
                        perf_header__set_feat(&session->header, HEADER_BUILD_ID);
                /*
                 * Keep all buildids when there is unprocessed AUX data because
                 * it is not known which ones the AUX trace hits.
                 */
                if (perf_header__has_feat(&session->header, HEADER_BUILD_ID) &&
                    inject->have_auxtrace && !inject->itrace_synth_opts.set)
                        perf_session__dsos_hit_all(session);
                /*
                 * The AUX areas have been removed and replaced with
                 * synthesized hardware events, so clear the feature flag.
                 */
                if (inject->itrace_synth_opts.set) {
                        perf_header__clear_feat(&session->header,
                                                HEADER_AUXTRACE);
                        if (inject->itrace_synth_opts.last_branch ||
                            inject->itrace_synth_opts.add_last_branch)
                                perf_header__set_feat(&session->header,
                                                      HEADER_BRANCH_STACK);
                }

                /*
                 * The converted data file won't have stack and registers.
                 * Update the perf_event_attr to remove them before writing.
                 */
                if (inject->convert_callchain) {
                        struct evsel *evsel;

                        evlist__for_each_entry(session->evlist, evsel) {
                                evsel__reset_sample_bit(evsel, REGS_USER);
                                evsel__reset_sample_bit(evsel, STACK_USER);
                                evsel->core.attr.sample_regs_user = 0;
                                evsel->core.attr.sample_stack_user = 0;
                                evsel->core.attr.exclude_callchain_user = 0;
                        }
                }

                session->header.data_offset = output_data_offset;
                session->header.data_size = inject->bytes_written;
                perf_session__inject_header(session, session->evlist, fd, &inj_fc.fc,
                                            write_attrs_after_data);

                if (inject->copy_kcore_dir) {
                        ret = copy_kcore_dir(inject);
                        if (ret) {
                                pr_err("Failed to copy kcore\n");
                                return ret;
                        }
                }
                if (gs->copy_kcore_dir) {
                        ret = guest_session__copy_kcore_dir(gs);
                        if (ret) {
                                pr_err("Failed to copy guest kcore\n");
                                return ret;
                        }
                }
        }

        return ret;
}

static bool evsel__has_dwarf_callchain(struct evsel *evsel)
{
        struct perf_event_attr *attr = &evsel->core.attr;
        const u64 dwarf_callchain_flags =
                PERF_SAMPLE_STACK_USER | PERF_SAMPLE_REGS_USER | PERF_SAMPLE_CALLCHAIN;

        if (!attr->exclude_callchain_user)
                return false;

        return (attr->sample_type & dwarf_callchain_flags) == dwarf_callchain_flags;
}

int cmd_inject(int argc, const char **argv)
{
        struct perf_inject inject = {
                .input_name  = "-",
                .samples = LIST_HEAD_INIT(inject.samples),
                .output = {
                        .path = "-",
                        .mode = PERF_DATA_MODE_WRITE,
                        .use_stdio = true,
                },
        };
        struct perf_data data = {
                .mode = PERF_DATA_MODE_READ,
                .use_stdio = true,
        };
        int ret;
        const char *known_build_ids = NULL;
        bool build_ids = false;
        bool build_id_all = false;
        bool mmap2_build_ids = false;
        bool mmap2_build_id_all = false;

        struct option options[] = {
                OPT_BOOLEAN('b', "build-ids", &build_ids,
                            "Inject build-ids into the output stream"),
                OPT_BOOLEAN(0, "buildid-all", &build_id_all,
                            "Inject build-ids of all DSOs into the output stream"),
                OPT_BOOLEAN('B', "mmap2-buildids", &mmap2_build_ids,
                            "Drop unused mmap events, make others mmap2 with build IDs"),
                OPT_BOOLEAN(0, "mmap2-buildid-all", &mmap2_build_id_all,
                            "Rewrite all mmap events as mmap2 events with build IDs"),
                OPT_STRING(0, "known-build-ids", &known_build_ids,
                           "buildid path [,buildid path...]",
                           "build-ids to use for given paths"),
                OPT_STRING('i', "input", &inject.input_name, "file",
                           "input file name"),
                OPT_STRING('o', "output", &inject.output.path, "file",
                           "output file name"),
                OPT_BOOLEAN('s', "sched-stat", &inject.sched_stat,
                            "Merge sched-stat and sched-switch for getting events "
                            "where and how long tasks slept"),
#ifdef HAVE_JITDUMP
                OPT_BOOLEAN('j', "jit", &inject.jit_mode, "merge jitdump files into perf.data file"),
#endif
                OPT_INCR('v', "verbose", &verbose,
                         "be more verbose (show build ids, etc)"),
                OPT_STRING('k', "vmlinux", &symbol_conf.vmlinux_name,
                           "file", "vmlinux pathname"),
                OPT_BOOLEAN(0, "ignore-vmlinux", &symbol_conf.ignore_vmlinux,
                            "don't load vmlinux even if found"),
                OPT_STRING(0, "kallsyms", &symbol_conf.kallsyms_name, "file",
                           "kallsyms pathname"),
                OPT_BOOLEAN('f', "force", &data.force, "don't complain, do it"),
                OPT_CALLBACK_OPTARG(0, "itrace", &inject.itrace_synth_opts,
                                    NULL, "opts", "Instruction Tracing options\n"
                                    ITRACE_HELP,
                                    itrace_parse_synth_opts),
                OPT_BOOLEAN(0, "strip", &inject.strip,
                            "strip non-synthesized events (use with --itrace)"),
                OPT_CALLBACK_OPTARG(0, "vm-time-correlation", &inject, NULL, "opts",
                                    "correlate time between VM guests and the host",
                                    parse_vm_time_correlation),
                OPT_CALLBACK_OPTARG(0, "guest-data", &inject, NULL, "opts",
                                    "inject events from a guest perf.data file",
                                    parse_guest_data),
                OPT_STRING(0, "guestmount", &symbol_conf.guestmount, "directory",
                           "guest mount directory under which every guest os"
                           " instance has a subdir"),
                OPT_BOOLEAN(0, "convert-callchain", &inject.convert_callchain,
                            "Generate callchains using DWARF and drop register/stack data"),
                OPT_END()
        };
        const char * const inject_usage[] = {
                "perf inject [<options>]",
                NULL
        };
        bool ordered_events;

        if (!inject.itrace_synth_opts.set) {
                /* Disable eager loading of kernel symbols that adds overhead to perf inject. */
                symbol_conf.lazy_load_kernel_maps = true;
        }

#ifndef HAVE_JITDUMP
        set_option_nobuild(options, 'j', "jit", "NO_LIBELF=1", true);
#endif
#ifndef HAVE_LIBDW_SUPPORT
        set_option_nobuild(options, 0, "convert-callchain", "NO_LIBDW=1", true);
#endif
        argc = parse_options(argc, argv, options, inject_usage, 0);

        /*
         * Any (unrecognized) arguments left?
         */
        if (argc)
                usage_with_options(inject_usage, options);

        if (inject.strip && !inject.itrace_synth_opts.set) {
                pr_err("--strip option requires --itrace option\n");
                return -1;
        }

        if (symbol__validate_sym_arguments())
                return -1;

        if (inject.in_place_update) {
                if (!strcmp(inject.input_name, "-")) {
                        pr_err("Input file name required for in-place updating\n");
                        return -1;
                }
                if (strcmp(inject.output.path, "-")) {
                        pr_err("Output file name must not be specified for in-place updating\n");
                        return -1;
                }
                if (!data.force && !inject.in_place_update_dry_run) {
                        pr_err("The input file would be updated in place, "
                                "the --force option is required.\n");
                        return -1;
                }
                if (!inject.in_place_update_dry_run)
                        data.in_place_update = true;
        } else {
                if (strcmp(inject.output.path, "-") && !inject.strip &&
                    has_kcore_dir(inject.input_name)) {
                        inject.output.is_dir = true;
                        inject.copy_kcore_dir = true;
                }
                if (perf_data__open(&inject.output)) {
                        perror("failed to create output file");
                        return -1;
                }
        }
        if (mmap2_build_ids)
                inject.build_id_style = BID_RWS__MMAP2_BUILDID_LAZY;
        if (mmap2_build_id_all)
                inject.build_id_style = BID_RWS__MMAP2_BUILDID_ALL;
        if (build_ids)
                inject.build_id_style = BID_RWS__INJECT_HEADER_LAZY;
        if (build_id_all)
                inject.build_id_style = BID_RWS__INJECT_HEADER_ALL;

        data.path = inject.input_name;

        ordered_events = inject.jit_mode || inject.sched_stat ||
                inject.build_id_style == BID_RWS__INJECT_HEADER_LAZY ||
                inject.build_id_style == BID_RWS__MMAP2_BUILDID_LAZY;
        perf_tool__init(&inject.tool, ordered_events);
        inject.tool.sample              = perf_event__repipe_sample;
        inject.tool.read                = perf_event__repipe_sample;
        inject.tool.mmap                = perf_event__repipe;
        inject.tool.mmap2               = perf_event__repipe;
        inject.tool.comm                = perf_event__repipe;
        inject.tool.namespaces          = perf_event__repipe;
        inject.tool.cgroup              = perf_event__repipe;
        inject.tool.fork                = perf_event__repipe;
        inject.tool.exit                = perf_event__repipe;
        inject.tool.lost                = perf_event__repipe;
        inject.tool.lost_samples        = perf_event__repipe;
        inject.tool.aux                 = perf_event__repipe;
        inject.tool.itrace_start        = perf_event__repipe;
        inject.tool.aux_output_hw_id    = perf_event__repipe;
        inject.tool.context_switch      = perf_event__repipe;
        inject.tool.throttle            = perf_event__repipe;
        inject.tool.unthrottle          = perf_event__repipe;
        inject.tool.ksymbol             = perf_event__repipe;
        inject.tool.bpf                 = perf_event__repipe;
        inject.tool.text_poke           = perf_event__repipe;
        inject.tool.attr                = perf_event__repipe_attr;
        inject.tool.event_update        = perf_event__repipe_event_update;
        inject.tool.tracing_data        = perf_event__repipe_op2_synth;
        inject.tool.finished_round      = perf_event__repipe_oe_synth;
        inject.tool.build_id            = perf_event__repipe_op2_synth;
        inject.tool.id_index            = perf_event__repipe_op2_synth;
        inject.tool.auxtrace_info       = perf_event__repipe_op2_synth;
        inject.tool.auxtrace_error      = perf_event__repipe_op2_synth;
        inject.tool.time_conv           = perf_event__repipe_op2_synth;
        inject.tool.thread_map          = perf_event__repipe_op2_synth;
        inject.tool.cpu_map             = perf_event__repipe_op2_synth;
        inject.tool.stat_config         = perf_event__repipe_op2_synth;
        inject.tool.stat                = perf_event__repipe_op2_synth;
        inject.tool.stat_round          = perf_event__repipe_op2_synth;
        inject.tool.feature             = perf_event__repipe_op2_synth;
        inject.tool.finished_init       = perf_event__repipe_op2_synth;
        inject.tool.compressed          = perf_event__repipe_op4_synth;
        inject.tool.auxtrace            = perf_event__repipe_auxtrace;
        inject.tool.bpf_metadata        = perf_event__repipe_op2_synth;
        inject.tool.schedstat_cpu       = perf_event__repipe_op2_synth;
        inject.tool.schedstat_domain    = perf_event__repipe_op2_synth;
        inject.tool.dont_split_sample_group = true;
        inject.tool.merge_deferred_callchains = false;
        inject.session = __perf_session__new(&data, &inject.tool,
                                             /*trace_event_repipe=*/inject.output.is_pipe,
                                             /*host_env=*/NULL);

        if (IS_ERR(inject.session)) {
                ret = PTR_ERR(inject.session);
                goto out_close_output;
        }

        if (zstd_init(&(inject.session->zstd_data), 0) < 0)
                pr_warning("Decompression initialization failed.\n");

        /* Save original section info before feature bits change */
        ret = save_section_info(&inject);
        if (ret)
                goto out_delete;

        if (inject.output.is_pipe) {
                ret = perf_header__write_pipe(perf_data__fd(&inject.output));
                if (ret < 0) {
                        pr_err("Couldn't write a new pipe header.\n");
                        goto out_delete;
                }

                /*
                 * If the input is already a pipe then the features and
                 * attributes don't need synthesizing, they will be present in
                 * the input.
                 */
                if (!data.is_pipe) {
                        ret = perf_event__synthesize_for_pipe(&inject.tool,
                                                              inject.session,
                                                              &inject.output,
                                                              perf_event__repipe);
                        if (ret < 0)
                                goto out_delete;
                }
        }

        if (inject.build_id_style == BID_RWS__INJECT_HEADER_LAZY ||
            inject.build_id_style == BID_RWS__MMAP2_BUILDID_LAZY) {
                /*
                 * to make sure the mmap records are ordered correctly
                 * and so that the correct especially due to jitted code
                 * mmaps. We cannot generate the buildid hit list and
                 * inject the jit mmaps at the same time for now.
                 */
                inject.tool.ordering_requires_timestamps = true;
        }
        if (inject.build_id_style != BID_RWS__NONE && known_build_ids != NULL) {
                inject.known_build_ids =
                        perf_inject__parse_known_build_ids(known_build_ids);

                if (inject.known_build_ids == NULL) {
                        pr_err("Couldn't parse known build ids.\n");
                        goto out_delete;
                }
        }

        if (inject.convert_callchain) {
                struct evsel *evsel;

                if (inject.output.is_pipe || inject.session->data->is_pipe) {
                        pr_err("--convert-callchain cannot work with pipe\n");
                        goto out_delete;
                }

                evlist__for_each_entry(inject.session->evlist, evsel) {
                        if (!evsel__has_dwarf_callchain(evsel) && !evsel__is_dummy_event(evsel)) {
                                pr_err("--convert-callchain requires DWARF call graph.\n");
                                goto out_delete;
                        }
                }

                inject.raw_callchain = calloc(PERF_MAX_STACK_DEPTH, sizeof(u64));
                if (inject.raw_callchain == NULL) {
                        pr_err("callchain allocation failed\n");
                        goto out_delete;
                }
        }

#ifdef HAVE_JITDUMP
        if (inject.jit_mode) {
                inject.tool.mmap2          = perf_event__repipe_mmap2;
                inject.tool.mmap           = perf_event__repipe_mmap;
                inject.tool.ordering_requires_timestamps = true;
                /*
                 * JIT MMAP injection injects all MMAP events in one go, so it
                 * does not obey finished_round semantics.
                 */
                inject.tool.finished_round = perf_event__drop_oe;
        }
#endif
        ret = symbol__init(perf_session__env(inject.session));
        if (ret < 0)
                goto out_delete;

        ret = __cmd_inject(&inject);

        guest_session__exit(&inject.guest_session);

out_delete:
        strlist__delete(inject.known_build_ids);
        zstd_fini(&(inject.session->zstd_data));
        perf_session__delete(inject.session);
out_close_output:
        if (!inject.in_place_update)
                perf_data__close(&inject.output);
        free(inject.itrace_synth_opts.vm_tm_corr_args);
        free(inject.event_copy);
        free(inject.guest_session.ev.event_buf);
        free(inject.raw_callchain);
        return ret;
}