auxtrace.c

Go to the documentation of this file.

/*
 * auxtrace.c: AUX area trace support
 * Copyright (c) 2013-2015, Intel Corporation.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 */

#include <inttypes.h>
#include <sys/types.h>
#include <sys/mman.h>
#include <stdbool.h>
#include <string.h>
#include <limits.h>
#include <errno.h>

#include <linux/kernel.h>
#include <linux/perf_event.h>
#include <linux/types.h>
#include <linux/bitops.h>
#include <linux/log2.h>
#include <linux/string.h>

#include <sys/param.h>
#include <stdlib.h>
#include <stdio.h>
#include <linux/list.h>

#include "../perf.h"
#include "util.h"
#include "evlist.h"
#include "dso.h"
#include "map.h"
#include "pmu.h"
#include "evsel.h"
#include "cpumap.h"
#include "thread_map.h"
#include "asm/bug.h"
#include "auxtrace.h"

#include <linux/hash.h>

#include "event.h"
#include "session.h"
#include "debug.h"
#include <subcmd/parse-options.h>

#include "cs-etm.h"
#include "intel-pt.h"
#include "intel-bts.h"
#include "arm-spe.h"

#include "sane_ctype.h"
#include "symbol/kallsyms.h"

static bool auxtrace__dont_decode(struct perf_session *session)
{
    return !session->itrace_synth_opts ||
           session->itrace_synth_opts->dont_decode;
}

int auxtrace_mmap__mmap(struct auxtrace_mmap *mm,
            struct auxtrace_mmap_params *mp,
            void *userpg, int fd)
{
    struct perf_event_mmap_page *pc = userpg;

    WARN_ONCE(mm->base, "Uninitialized auxtrace_mmap\n");

    mm->userpg = userpg;
    mm->mask = mp->mask;
    mm->len = mp->len;
    mm->prev = 0;
    mm->idx = mp->idx;
    mm->tid = mp->tid;
    mm->cpu = mp->cpu;

    if (!mp->len) {
        mm->base = NULL;
        return 0;
    }

#if BITS_PER_LONG != 64 && !defined(HAVE_SYNC_COMPARE_AND_SWAP_SUPPORT)
    pr_err("Cannot use AUX area tracing mmaps\n");
    return -1;
#endif

    pc->aux_offset = mp->offset;
    pc->aux_size = mp->len;

    mm->base = mmap(NULL, mp->len, mp->prot, MAP_SHARED, fd, mp->offset);
    if (mm->base == MAP_FAILED) {
        pr_debug2("failed to mmap AUX area\n");
        mm->base = NULL;
        return -1;
    }

    return 0;
}

void auxtrace_mmap__munmap(struct auxtrace_mmap *mm)
{
    if (mm->base) {
        munmap(mm->base, mm->len);
        mm->base = NULL;
    }
}

void auxtrace_mmap_params__init(struct auxtrace_mmap_params *mp,
                off_t auxtrace_offset,
                unsigned int auxtrace_pages,
                bool auxtrace_overwrite)
{
    if (auxtrace_pages) {
        mp->offset = auxtrace_offset;
        mp->len = auxtrace_pages * (size_t)page_size;
        mp->mask = is_power_of_2(mp->len) ? mp->len - 1 : 0;
        mp->prot = PROT_READ | (auxtrace_overwrite ? 0 : PROT_WRITE);
        pr_debug2("AUX area mmap length %zu\n", mp->len);
    } else {
        mp->len = 0;
    }
}

void auxtrace_mmap_params__set_idx(struct auxtrace_mmap_params *mp,
                   struct perf_evlist *evlist, int idx,
                   bool per_cpu)
{
    mp->idx = idx;

    if (per_cpu) {
        mp->cpu = evlist->cpus->map[idx];
        if (evlist->threads)
            mp->tid = thread_map__pid(evlist->threads, 0);
        else
            mp->tid = -1;
    } else {
        mp->cpu = -1;
        mp->tid = thread_map__pid(evlist->threads, idx);
    }
}

#define AUXTRACE_INIT_NR_QUEUES 32

static struct auxtrace_queue *auxtrace_alloc_queue_array(unsigned int nr_queues)
{
    struct auxtrace_queue *queue_array;
    unsigned int max_nr_queues, i;

    max_nr_queues = UINT_MAX / sizeof(struct auxtrace_queue);
    if (nr_queues > max_nr_queues)
        return NULL;

    queue_array = calloc(nr_queues, sizeof(struct auxtrace_queue));
    if (!queue_array)
        return NULL;

    for (i = 0; i < nr_queues; i++) {
        INIT_LIST_HEAD(&queue_array[i].head);
        queue_array[i].priv = NULL;
    }

    return queue_array;
}

int auxtrace_queues__init(struct auxtrace_queues *queues)
{
    queues->nr_queues = AUXTRACE_INIT_NR_QUEUES;
    queues->queue_array = auxtrace_alloc_queue_array(queues->nr_queues);
    if (!queues->queue_array)
        return -ENOMEM;
    return 0;
}

static int auxtrace_queues__grow(struct auxtrace_queues *queues,
                 unsigned int new_nr_queues)
{
    unsigned int nr_queues = queues->nr_queues;
    struct auxtrace_queue *queue_array;
    unsigned int i;

    if (!nr_queues)
        nr_queues = AUXTRACE_INIT_NR_QUEUES;

    while (nr_queues && nr_queues < new_nr_queues)
        nr_queues <<= 1;

    if (nr_queues < queues->nr_queues || nr_queues < new_nr_queues)
        return -EINVAL;

    queue_array = auxtrace_alloc_queue_array(nr_queues);
    if (!queue_array)
        return -ENOMEM;

    for (i = 0; i < queues->nr_queues; i++) {
        list_splice_tail(&queues->queue_array[i].head,
                 &queue_array[i].head);
        queue_array[i].priv = queues->queue_array[i].priv;
    }

    queues->nr_queues = nr_queues;
    queues->queue_array = queue_array;

    return 0;
}

static void *auxtrace_copy_data(u64 size, struct perf_session *session)
{
    int fd = perf_data__fd(session->data);
    void *p;
    ssize_t ret;

    if (size > SSIZE_MAX)
        return NULL;

    p = malloc(size);
    if (!p)
        return NULL;

    ret = readn(fd, p, size);
    if (ret != (ssize_t)size) {
        free(p);
        return NULL;
    }

    return p;
}

static int auxtrace_queues__queue_buffer(struct auxtrace_queues *queues,
                     unsigned int idx,
                     struct auxtrace_buffer *buffer)
{
    struct auxtrace_queue *queue;
    int err;

    if (idx >= queues->nr_queues) {
        err = auxtrace_queues__grow(queues, idx + 1);
        if (err)
            return err;
    }

    queue = &queues->queue_array[idx];

    if (!queue->set) {
        queue->set = true;
        queue->tid = buffer->tid;
        queue->cpu = buffer->cpu;
    } else if (buffer->cpu != queue->cpu || buffer->tid != queue->tid) {
        pr_err("auxtrace queue conflict: cpu %d, tid %d vs cpu %d, tid %d\n",
               queue->cpu, queue->tid, buffer->cpu, buffer->tid);
        return -EINVAL;
    }

    buffer->buffer_nr = queues->next_buffer_nr++;

    list_add_tail(&buffer->list, &queue->head);

    queues->new_data = true;
    queues->populated = true;

    return 0;
}

/* Limit buffers to 32MiB on 32-bit */
#define BUFFER_LIMIT_FOR_32_BIT (32 * 1024 * 1024)

static int auxtrace_queues__split_buffer(struct auxtrace_queues *queues,
                     unsigned int idx,
                     struct auxtrace_buffer *buffer)
{
    u64 sz = buffer->size;
    bool consecutive = false;
    struct auxtrace_buffer *b;
    int err;

    while (sz > BUFFER_LIMIT_FOR_32_BIT) {
        b = memdup(buffer, sizeof(struct auxtrace_buffer));
        if (!b)
            return -ENOMEM;
        b->size = BUFFER_LIMIT_FOR_32_BIT;
        b->consecutive = consecutive;
        err = auxtrace_queues__queue_buffer(queues, idx, b);
        if (err) {
            auxtrace_buffer__free(b);
            return err;
        }
        buffer->data_offset += BUFFER_LIMIT_FOR_32_BIT;
        sz -= BUFFER_LIMIT_FOR_32_BIT;
        consecutive = true;
    }

    buffer->size = sz;
    buffer->consecutive = consecutive;

    return 0;
}

static bool filter_cpu(struct perf_session *session, int cpu)
{
    unsigned long *cpu_bitmap = session->itrace_synth_opts->cpu_bitmap;

    return cpu_bitmap && cpu != -1 && !test_bit(cpu, cpu_bitmap);
}

static int auxtrace_queues__add_buffer(struct auxtrace_queues *queues,
                       struct perf_session *session,
                       unsigned int idx,
                       struct auxtrace_buffer *buffer,
                       struct auxtrace_buffer **buffer_ptr)
{
    int err = -ENOMEM;

    if (filter_cpu(session, buffer->cpu))
        return 0;

    buffer = memdup(buffer, sizeof(*buffer));
    if (!buffer)
        return -ENOMEM;

    if (session->one_mmap) {
        buffer->data = buffer->data_offset - session->one_mmap_offset +
                   session->one_mmap_addr;
    } else if (perf_data__is_pipe(session->data)) {
        buffer->data = auxtrace_copy_data(buffer->size, session);
        if (!buffer->data)
            goto out_free;
        buffer->data_needs_freeing = true;
    } else if (BITS_PER_LONG == 32 &&
           buffer->size > BUFFER_LIMIT_FOR_32_BIT) {
        err = auxtrace_queues__split_buffer(queues, idx, buffer);
        if (err)
            goto out_free;
    }

    err = auxtrace_queues__queue_buffer(queues, idx, buffer);
    if (err)
        goto out_free;

    /* FIXME: Doesn't work for split buffer */
    if (buffer_ptr)
        *buffer_ptr = buffer;

    return 0;

out_free:
    auxtrace_buffer__free(buffer);
    return err;
}

int auxtrace_queues__add_event(struct auxtrace_queues *queues,
                   struct perf_session *session,
                   union perf_event *event, off_t data_offset,
                   struct auxtrace_buffer **buffer_ptr)
{
    struct auxtrace_buffer buffer = {
        .pid = -1,
        .tid = event->auxtrace.tid,
        .cpu = event->auxtrace.cpu,
        .data_offset = data_offset,
        .offset = event->auxtrace.offset,
        .reference = event->auxtrace.reference,
        .size = event->auxtrace.size,
    };
    unsigned int idx = event->auxtrace.idx;

    return auxtrace_queues__add_buffer(queues, session, idx, &buffer,
                       buffer_ptr);
}

static int auxtrace_queues__add_indexed_event(struct auxtrace_queues *queues,
                          struct perf_session *session,
                          off_t file_offset, size_t sz)
{
    union perf_event *event;
    int err;
    char buf[PERF_SAMPLE_MAX_SIZE];

    err = perf_session__peek_event(session, file_offset, buf,
                       PERF_SAMPLE_MAX_SIZE, &event, NULL);
    if (err)
        return err;

    if (event->header.type == PERF_RECORD_AUXTRACE) {
        if (event->header.size < sizeof(struct auxtrace_event) ||
            event->header.size != sz) {
            err = -EINVAL;
            goto out;
        }
        file_offset += event->header.size;
        err = auxtrace_queues__add_event(queues, session, event,
                         file_offset, NULL);
    }
out:
    return err;
}

void auxtrace_queues__free(struct auxtrace_queues *queues)
{
    unsigned int i;

    for (i = 0; i < queues->nr_queues; i++) {
        while (!list_empty(&queues->queue_array[i].head)) {
            struct auxtrace_buffer *buffer;

            buffer = list_entry(queues->queue_array[i].head.next,
                        struct auxtrace_buffer, list);
            list_del(&buffer->list);
            auxtrace_buffer__free(buffer);
        }
    }

    zfree(&queues->queue_array);
    queues->nr_queues = 0;
}

static void auxtrace_heapify(struct auxtrace_heap_item *heap_array,
                 unsigned int pos, unsigned int queue_nr,
                 u64 ordinal)
{
    unsigned int parent;

    while (pos) {
        parent = (pos - 1) >> 1;
        if (heap_array[parent].ordinal <= ordinal)
            break;
        heap_array[pos] = heap_array[parent];
        pos = parent;
    }
    heap_array[pos].queue_nr = queue_nr;
    heap_array[pos].ordinal = ordinal;
}

int auxtrace_heap__add(struct auxtrace_heap *heap, unsigned int queue_nr,
               u64 ordinal)
{
    struct auxtrace_heap_item *heap_array;

    if (queue_nr >= heap->heap_sz) {
        unsigned int heap_sz = AUXTRACE_INIT_NR_QUEUES;

        while (heap_sz <= queue_nr)
            heap_sz <<= 1;
        heap_array = realloc(heap->heap_array,
                     heap_sz * sizeof(struct auxtrace_heap_item));
        if (!heap_array)
            return -ENOMEM;
        heap->heap_array = heap_array;
        heap->heap_sz = heap_sz;
    }

    auxtrace_heapify(heap->heap_array, heap->heap_cnt++, queue_nr, ordinal);

    return 0;
}

void auxtrace_heap__free(struct auxtrace_heap *heap)
{
    zfree(&heap->heap_array);
    heap->heap_cnt = 0;
    heap->heap_sz = 0;
}

void auxtrace_heap__pop(struct auxtrace_heap *heap)
{
    unsigned int pos, last, heap_cnt = heap->heap_cnt;
    struct auxtrace_heap_item *heap_array;

    if (!heap_cnt)
        return;

    heap->heap_cnt -= 1;

    heap_array = heap->heap_array;

    pos = 0;
    while (1) {
        unsigned int left, right;

        left = (pos << 1) + 1;
        if (left >= heap_cnt)
            break;
        right = left + 1;
        if (right >= heap_cnt) {
            heap_array[pos] = heap_array[left];
            return;
        }
        if (heap_array[left].ordinal < heap_array[right].ordinal) {
            heap_array[pos] = heap_array[left];
            pos = left;
        } else {
            heap_array[pos] = heap_array[right];
            pos = right;
        }
    }

    last = heap_cnt - 1;
    auxtrace_heapify(heap_array, pos, heap_array[last].queue_nr,
             heap_array[last].ordinal);
}

size_t auxtrace_record__info_priv_size(struct auxtrace_record *itr,
                       struct perf_evlist *evlist)
{
    if (itr)
        return itr->info_priv_size(itr, evlist);
    return 0;
}

static int auxtrace_not_supported(void)
{
    pr_err("AUX area tracing is not supported on this architecture\n");
    return -EINVAL;
}

int auxtrace_record__info_fill(struct auxtrace_record *itr,
                   struct perf_session *session,
                   struct auxtrace_info_event *auxtrace_info,
                   size_t priv_size)
{
    if (itr)
        return itr->info_fill(itr, session, auxtrace_info, priv_size);
    return auxtrace_not_supported();
}

void auxtrace_record__free(struct auxtrace_record *itr)
{
    if (itr)
        itr->free(itr);
}

int auxtrace_record__snapshot_start(struct auxtrace_record *itr)
{
    if (itr && itr->snapshot_start)
        return itr->snapshot_start(itr);
    return 0;
}

int auxtrace_record__snapshot_finish(struct auxtrace_record *itr)
{
    if (itr && itr->snapshot_finish)
        return itr->snapshot_finish(itr);
    return 0;
}

int auxtrace_record__find_snapshot(struct auxtrace_record *itr, int idx,
                   struct auxtrace_mmap *mm,
                   unsigned char *data, u64 *head, u64 *old)
{
    if (itr && itr->find_snapshot)
        return itr->find_snapshot(itr, idx, mm, data, head, old);
    return 0;
}

int auxtrace_record__options(struct auxtrace_record *itr,
                 struct perf_evlist *evlist,
                 struct record_opts *opts)
{
    if (itr)
        return itr->recording_options(itr, evlist, opts);
    return 0;
}

u64 auxtrace_record__reference(struct auxtrace_record *itr)
{
    if (itr)
        return itr->reference(itr);
    return 0;
}

int auxtrace_parse_snapshot_options(struct auxtrace_record *itr,
                    struct record_opts *opts, const char *str)
{
    if (!str)
        return 0;

    if (itr)
        return itr->parse_snapshot_options(itr, opts, str);

    pr_err("No AUX area tracing to snapshot\n");
    return -EINVAL;
}

struct auxtrace_record *__weak
auxtrace_record__init(struct perf_evlist *evlist __maybe_unused, int *err)
{
    *err = 0;
    return NULL;
}

static int auxtrace_index__alloc(struct list_head *head)
{
    struct auxtrace_index *auxtrace_index;

    auxtrace_index = malloc(sizeof(struct auxtrace_index));
    if (!auxtrace_index)
        return -ENOMEM;

    auxtrace_index->nr = 0;
    INIT_LIST_HEAD(&auxtrace_index->list);

    list_add_tail(&auxtrace_index->list, head);

    return 0;
}

void auxtrace_index__free(struct list_head *head)
{
    struct auxtrace_index *auxtrace_index, *n;

    list_for_each_entry_safe(auxtrace_index, n, head, list) {
        list_del(&auxtrace_index->list);
        free(auxtrace_index);
    }
}

static struct auxtrace_index *auxtrace_index__last(struct list_head *head)
{
    struct auxtrace_index *auxtrace_index;
    int err;

    if (list_empty(head)) {
        err = auxtrace_index__alloc(head);
        if (err)
            return NULL;
    }

    auxtrace_index = list_entry(head->prev, struct auxtrace_index, list);

    if (auxtrace_index->nr >= PERF_AUXTRACE_INDEX_ENTRY_COUNT) {
        err = auxtrace_index__alloc(head);
        if (err)
            return NULL;
        auxtrace_index = list_entry(head->prev, struct auxtrace_index,
                        list);
    }

    return auxtrace_index;
}

int auxtrace_index__auxtrace_event(struct list_head *head,
                   union perf_event *event, off_t file_offset)
{
    struct auxtrace_index *auxtrace_index;
    size_t nr;

    auxtrace_index = auxtrace_index__last(head);
    if (!auxtrace_index)
        return -ENOMEM;

    nr = auxtrace_index->nr;
    auxtrace_index->entries[nr].file_offset = file_offset;
    auxtrace_index->entries[nr].sz = event->header.size;
    auxtrace_index->nr += 1;

    return 0;
}

static int auxtrace_index__do_write(int fd,
                    struct auxtrace_index *auxtrace_index)
{
    struct auxtrace_index_entry ent;
    size_t i;

    for (i = 0; i < auxtrace_index->nr; i++) {
        ent.file_offset = auxtrace_index->entries[i].file_offset;
        ent.sz = auxtrace_index->entries[i].sz;
        if (writen(fd, &ent, sizeof(ent)) != sizeof(ent))
            return -errno;
    }
    return 0;
}

int auxtrace_index__write(int fd, struct list_head *head)
{
    struct auxtrace_index *auxtrace_index;
    u64 total = 0;
    int err;

    list_for_each_entry(auxtrace_index, head, list)
        total += auxtrace_index->nr;

    if (writen(fd, &total, sizeof(total)) != sizeof(total))
        return -errno;

    list_for_each_entry(auxtrace_index, head, list) {
        err = auxtrace_index__do_write(fd, auxtrace_index);
        if (err)
            return err;
    }

    return 0;
}

static int auxtrace_index__process_entry(int fd, struct list_head *head,
                     bool needs_swap)
{
    struct auxtrace_index *auxtrace_index;
    struct auxtrace_index_entry ent;
    size_t nr;

    if (readn(fd, &ent, sizeof(ent)) != sizeof(ent))
        return -1;

    auxtrace_index = auxtrace_index__last(head);
    if (!auxtrace_index)
        return -1;

    nr = auxtrace_index->nr;
    if (needs_swap) {
        auxtrace_index->entries[nr].file_offset =
                        bswap_64(ent.file_offset);
        auxtrace_index->entries[nr].sz = bswap_64(ent.sz);
    } else {
        auxtrace_index->entries[nr].file_offset = ent.file_offset;
        auxtrace_index->entries[nr].sz = ent.sz;
    }

    auxtrace_index->nr = nr + 1;

    return 0;
}

int auxtrace_index__process(int fd, u64 size, struct perf_session *session,
                bool needs_swap)
{
    struct list_head *head = &session->auxtrace_index;
    u64 nr;

    if (readn(fd, &nr, sizeof(u64)) != sizeof(u64))
        return -1;

    if (needs_swap)
        nr = bswap_64(nr);

    if (sizeof(u64) + nr * sizeof(struct auxtrace_index_entry) > size)
        return -1;

    while (nr--) {
        int err;

        err = auxtrace_index__process_entry(fd, head, needs_swap);
        if (err)
            return -1;
    }

    return 0;
}

static int auxtrace_queues__process_index_entry(struct auxtrace_queues *queues,
                        struct perf_session *session,
                        struct auxtrace_index_entry *ent)
{
    return auxtrace_queues__add_indexed_event(queues, session,
                          ent->file_offset, ent->sz);
}

int auxtrace_queues__process_index(struct auxtrace_queues *queues,
                   struct perf_session *session)
{
    struct auxtrace_index *auxtrace_index;
    struct auxtrace_index_entry *ent;
    size_t i;
    int err;

    if (auxtrace__dont_decode(session))
        return 0;

    list_for_each_entry(auxtrace_index, &session->auxtrace_index, list) {
        for (i = 0; i < auxtrace_index->nr; i++) {
            ent = &auxtrace_index->entries[i];
            err = auxtrace_queues__process_index_entry(queues,
                                   session,
                                   ent);
            if (err)
                return err;
        }
    }
    return 0;
}

struct auxtrace_buffer *auxtrace_buffer__next(struct auxtrace_queue *queue,
                          struct auxtrace_buffer *buffer)
{
    if (buffer) {
        if (list_is_last(&buffer->list, &queue->head))
            return NULL;
        return list_entry(buffer->list.next, struct auxtrace_buffer,
                  list);
    } else {
        if (list_empty(&queue->head))
            return NULL;
        return list_entry(queue->head.next, struct auxtrace_buffer,
                  list);
    }
}

void *auxtrace_buffer__get_data(struct auxtrace_buffer *buffer, int fd)
{
    size_t adj = buffer->data_offset & (page_size - 1);
    size_t size = buffer->size + adj;
    off_t file_offset = buffer->data_offset - adj;
    void *addr;

    if (buffer->data)
        return buffer->data;

    addr = mmap(NULL, size, PROT_READ, MAP_SHARED, fd, file_offset);
    if (addr == MAP_FAILED)
        return NULL;

    buffer->mmap_addr = addr;
    buffer->mmap_size = size;

    buffer->data = addr + adj;

    return buffer->data;
}

void auxtrace_buffer__put_data(struct auxtrace_buffer *buffer)
{
    if (!buffer->data || !buffer->mmap_addr)
        return;
    munmap(buffer->mmap_addr, buffer->mmap_size);
    buffer->mmap_addr = NULL;
    buffer->mmap_size = 0;
    buffer->data = NULL;
    buffer->use_data = NULL;
}

void auxtrace_buffer__drop_data(struct auxtrace_buffer *buffer)
{
    auxtrace_buffer__put_data(buffer);
    if (buffer->data_needs_freeing) {
        buffer->data_needs_freeing = false;
        zfree(&buffer->data);
        buffer->use_data = NULL;
        buffer->size = 0;
    }
}

void auxtrace_buffer__free(struct auxtrace_buffer *buffer)
{
    auxtrace_buffer__drop_data(buffer);
    free(buffer);
}

void auxtrace_synth_error(struct auxtrace_error_event *auxtrace_error, int type,
              int code, int cpu, pid_t pid, pid_t tid, u64 ip,
              const char *msg)
{
    size_t size;

    memset(auxtrace_error, 0, sizeof(struct auxtrace_error_event));

    auxtrace_error->header.type = PERF_RECORD_AUXTRACE_ERROR;
    auxtrace_error->type = type;
    auxtrace_error->code = code;
    auxtrace_error->cpu = cpu;
    auxtrace_error->pid = pid;
    auxtrace_error->tid = tid;
    auxtrace_error->ip = ip;
    strlcpy(auxtrace_error->msg, msg, MAX_AUXTRACE_ERROR_MSG);

    size = (void *)auxtrace_error->msg - (void *)auxtrace_error +
           strlen(auxtrace_error->msg) + 1;
    auxtrace_error->header.size = PERF_ALIGN(size, sizeof(u64));
}

int perf_event__synthesize_auxtrace_info(struct auxtrace_record *itr,
                     struct perf_tool *tool,
                     struct perf_session *session,
                     perf_event__handler_t process)
{
    union perf_event *ev;
    size_t priv_size;
    int err;

    pr_debug2("Synthesizing auxtrace information\n");
    priv_size = auxtrace_record__info_priv_size(itr, session->evlist);
    ev = zalloc(sizeof(struct auxtrace_info_event) + priv_size);
    if (!ev)
        return -ENOMEM;

    ev->auxtrace_info.header.type = PERF_RECORD_AUXTRACE_INFO;
    ev->auxtrace_info.header.size = sizeof(struct auxtrace_info_event) +
                    priv_size;
    err = auxtrace_record__info_fill(itr, session, &ev->auxtrace_info,
                     priv_size);
    if (err)
        goto out_free;

    err = process(tool, ev, NULL, NULL);
out_free:
    free(ev);
    return err;
}

int perf_event__process_auxtrace_info(struct perf_tool *tool __maybe_unused,
                      union perf_event *event,
                      struct perf_session *session)
{
    enum auxtrace_type type = event->auxtrace_info.type;

    if (dump_trace)
        fprintf(stdout, " type: %u\n", type);

    switch (type) {
    case PERF_AUXTRACE_INTEL_PT:
        return intel_pt_process_auxtrace_info(event, session);
    case PERF_AUXTRACE_INTEL_BTS:
        return intel_bts_process_auxtrace_info(event, session);
    case PERF_AUXTRACE_ARM_SPE:
        return arm_spe_process_auxtrace_info(event, session);
    case PERF_AUXTRACE_CS_ETM:
        return cs_etm__process_auxtrace_info(event, session);
    case PERF_AUXTRACE_UNKNOWN:
    default:
        return -EINVAL;
    }
}

s64 perf_event__process_auxtrace(struct perf_tool *tool,
                 union perf_event *event,
                 struct perf_session *session)
{
    s64 err;

    if (dump_trace)
        fprintf(stdout, " size: %#"PRIx64"  offset: %#"PRIx64"  ref: %#"PRIx64"  idx: %u  tid: %d  cpu: %d\n",
            event->auxtrace.size, event->auxtrace.offset,
            event->auxtrace.reference, event->auxtrace.idx,
            event->auxtrace.tid, event->auxtrace.cpu);

    if (auxtrace__dont_decode(session))
        return event->auxtrace.size;

    if (!session->auxtrace || event->header.type != PERF_RECORD_AUXTRACE)
        return -EINVAL;

    err = session->auxtrace->process_auxtrace_event(session, event, tool);
    if (err < 0)
        return err;

    return event->auxtrace.size;
}

#define PERF_ITRACE_DEFAULT_PERIOD_TYPE     PERF_ITRACE_PERIOD_NANOSECS
#define PERF_ITRACE_DEFAULT_PERIOD      100000
#define PERF_ITRACE_DEFAULT_CALLCHAIN_SZ    16
#define PERF_ITRACE_MAX_CALLCHAIN_SZ        1024
#define PERF_ITRACE_DEFAULT_LAST_BRANCH_SZ  64
#define PERF_ITRACE_MAX_LAST_BRANCH_SZ      1024

void itrace_synth_opts__set_default(struct itrace_synth_opts *synth_opts)
{
    synth_opts->instructions = true;
    synth_opts->branches = true;
    synth_opts->transactions = true;
    synth_opts->ptwrites = true;
    synth_opts->pwr_events = true;
    synth_opts->errors = true;
    synth_opts->period_type = PERF_ITRACE_DEFAULT_PERIOD_TYPE;
    synth_opts->period = PERF_ITRACE_DEFAULT_PERIOD;
    synth_opts->callchain_sz = PERF_ITRACE_DEFAULT_CALLCHAIN_SZ;
    synth_opts->last_branch_sz = PERF_ITRACE_DEFAULT_LAST_BRANCH_SZ;
    synth_opts->initial_skip = 0;
}

/*
 * Please check tools/perf/Documentation/perf-script.txt for information
 * about the options parsed here, which is introduced after this cset,
 * when support in 'perf script' for these options is introduced.
 */
int itrace_parse_synth_opts(const struct option *opt, const char *str,
                int unset)
{
    struct itrace_synth_opts *synth_opts = opt->value;
    const char *p;
    char *endptr;
    bool period_type_set = false;
    bool period_set = false;

    synth_opts->set = true;

    if (unset) {
        synth_opts->dont_decode = true;
        return 0;
    }

    if (!str) {
        itrace_synth_opts__set_default(synth_opts);
        return 0;
    }

    for (p = str; *p;) {
        switch (*p++) {
        case 'i':
            synth_opts->instructions = true;
            while (*p == ' ' || *p == ',')
                p += 1;
            if (isdigit(*p)) {
                synth_opts->period = strtoull(p, &endptr, 10);
                period_set = true;
                p = endptr;
                while (*p == ' ' || *p == ',')
                    p += 1;
                switch (*p++) {
                case 'i':
                    synth_opts->period_type =
                        PERF_ITRACE_PERIOD_INSTRUCTIONS;
                    period_type_set = true;
                    break;
                case 't':
                    synth_opts->period_type =
                        PERF_ITRACE_PERIOD_TICKS;
                    period_type_set = true;
                    break;
                case 'm':
                    synth_opts->period *= 1000;
                    /* Fall through */
                case 'u':
                    synth_opts->period *= 1000;
                    /* Fall through */
                case 'n':
                    if (*p++ != 's')
                        goto out_err;
                    synth_opts->period_type =
                        PERF_ITRACE_PERIOD_NANOSECS;
                    period_type_set = true;
                    break;
                case '\0':
                    goto out;
                default:
                    goto out_err;
                }
            }
            break;
        case 'b':
            synth_opts->branches = true;
            break;
        case 'x':
            synth_opts->transactions = true;
            break;
        case 'w':
            synth_opts->ptwrites = true;
            break;
        case 'p':
            synth_opts->pwr_events = true;
            break;
        case 'e':
            synth_opts->errors = true;
            break;
        case 'd':
            synth_opts->log = true;
            break;
        case 'c':
            synth_opts->branches = true;
            synth_opts->calls = true;
            break;
        case 'r':
            synth_opts->branches = true;
            synth_opts->returns = true;
            break;
        case 'g':
            synth_opts->callchain = true;
            synth_opts->callchain_sz =
                    PERF_ITRACE_DEFAULT_CALLCHAIN_SZ;
            while (*p == ' ' || *p == ',')
                p += 1;
            if (isdigit(*p)) {
                unsigned int val;

                val = strtoul(p, &endptr, 10);
                p = endptr;
                if (!val || val > PERF_ITRACE_MAX_CALLCHAIN_SZ)
                    goto out_err;
                synth_opts->callchain_sz = val;
            }
            break;
        case 'l':
            synth_opts->last_branch = true;
            synth_opts->last_branch_sz =
                    PERF_ITRACE_DEFAULT_LAST_BRANCH_SZ;
            while (*p == ' ' || *p == ',')
                p += 1;
            if (isdigit(*p)) {
                unsigned int val;

                val = strtoul(p, &endptr, 10);
                p = endptr;
                if (!val ||
                    val > PERF_ITRACE_MAX_LAST_BRANCH_SZ)
                    goto out_err;
                synth_opts->last_branch_sz = val;
            }
            break;
        case 's':
            synth_opts->initial_skip = strtoul(p, &endptr, 10);
            if (p == endptr)
                goto out_err;
            p = endptr;
            break;
        case ' ':
        case ',':
            break;
        default:
            goto out_err;
        }
    }
out:
    if (synth_opts->instructions) {
        if (!period_type_set)
            synth_opts->period_type =
                    PERF_ITRACE_DEFAULT_PERIOD_TYPE;
        if (!period_set)
            synth_opts->period = PERF_ITRACE_DEFAULT_PERIOD;
    }

    return 0;

out_err:
    pr_err("Bad Instruction Tracing options '%s'\n", str);
    return -EINVAL;
}

static const char * const auxtrace_error_type_name[] = {
    [PERF_AUXTRACE_ERROR_ITRACE] = "instruction trace",
};

static const char *auxtrace_error_name(int type)
{
    const char *error_type_name = NULL;

    if (type < PERF_AUXTRACE_ERROR_MAX)
        error_type_name = auxtrace_error_type_name[type];
    if (!error_type_name)
        error_type_name = "unknown AUX";
    return error_type_name;
}

size_t perf_event__fprintf_auxtrace_error(union perf_event *event, FILE *fp)
{
    struct auxtrace_error_event *e = &event->auxtrace_error;
    int ret;

    ret = fprintf(fp, " %s error type %u",
              auxtrace_error_name(e->type), e->type);
    ret += fprintf(fp, " cpu %d pid %d tid %d ip %#"PRIx64" code %u: %s\n",
               e->cpu, e->pid, e->tid, e->ip, e->code, e->msg);
    return ret;
}

void perf_session__auxtrace_error_inc(struct perf_session *session,
                      union perf_event *event)
{
    struct auxtrace_error_event *e = &event->auxtrace_error;

    if (e->type < PERF_AUXTRACE_ERROR_MAX)
        session->evlist->stats.nr_auxtrace_errors[e->type] += 1;
}

void events_stats__auxtrace_error_warn(const struct events_stats *stats)
{
    int i;

    for (i = 0; i < PERF_AUXTRACE_ERROR_MAX; i++) {
        if (!stats->nr_auxtrace_errors[i])
            continue;
        ui__warning("%u %s errors\n",
                stats->nr_auxtrace_errors[i],
                auxtrace_error_name(i));
    }
}

int perf_event__process_auxtrace_error(struct perf_tool *tool __maybe_unused,
                       union perf_event *event,
                       struct perf_session *session)
{
    if (auxtrace__dont_decode(session))
        return 0;

    perf_event__fprintf_auxtrace_error(event, stdout);
    return 0;
}

static int __auxtrace_mmap__read(struct auxtrace_mmap *mm,
                 struct auxtrace_record *itr,
                 struct perf_tool *tool, process_auxtrace_t fn,
                 bool snapshot, size_t snapshot_size)
{
    u64 head, old = mm->prev, offset, ref;
    unsigned char *data = mm->base;
    size_t size, head_off, old_off, len1, len2, padding;
    union perf_event ev;
    void *data1, *data2;

    if (snapshot) {
        head = auxtrace_mmap__read_snapshot_head(mm);
        if (auxtrace_record__find_snapshot(itr, mm->idx, mm, data,
                           &head, &old))
            return -1;
    } else {
        head = auxtrace_mmap__read_head(mm);
    }

    if (old == head)
        return 0;

    pr_debug3("auxtrace idx %d old %#"PRIx64" head %#"PRIx64" diff %#"PRIx64"\n",
          mm->idx, old, head, head - old);

    if (mm->mask) {
        head_off = head & mm->mask;
        old_off = old & mm->mask;
    } else {
        head_off = head % mm->len;
        old_off = old % mm->len;
    }

    if (head_off > old_off)
        size = head_off - old_off;
    else
        size = mm->len - (old_off - head_off);

    if (snapshot && size > snapshot_size)
        size = snapshot_size;

    ref = auxtrace_record__reference(itr);

    if (head > old || size <= head || mm->mask) {
        offset = head - size;
    } else {
        /*
         * When the buffer size is not a power of 2, 'head' wraps at the
         * highest multiple of the buffer size, so we have to subtract
         * the remainder here.
         */
        u64 rem = (0ULL - mm->len) % mm->len;

        offset = head - size - rem;
    }

    if (size > head_off) {
        len1 = size - head_off;
        data1 = &data[mm->len - len1];
        len2 = head_off;
        data2 = &data[0];
    } else {
        len1 = size;
        data1 = &data[head_off - len1];
        len2 = 0;
        data2 = NULL;
    }

    if (itr->alignment) {
        unsigned int unwanted = len1 % itr->alignment;

        len1 -= unwanted;
        size -= unwanted;
    }

    /* padding must be written by fn() e.g. record__process_auxtrace() */
    padding = size & 7;
    if (padding)
        padding = 8 - padding;

    memset(&ev, 0, sizeof(ev));
    ev.auxtrace.header.type = PERF_RECORD_AUXTRACE;
    ev.auxtrace.header.size = sizeof(ev.auxtrace);
    ev.auxtrace.size = size + padding;
    ev.auxtrace.offset = offset;
    ev.auxtrace.reference = ref;
    ev.auxtrace.idx = mm->idx;
    ev.auxtrace.tid = mm->tid;
    ev.auxtrace.cpu = mm->cpu;

    if (fn(tool, &ev, data1, len1, data2, len2))
        return -1;

    mm->prev = head;

    if (!snapshot) {
        auxtrace_mmap__write_tail(mm, head);
        if (itr->read_finish) {
            int err;

            err = itr->read_finish(itr, mm->idx);
            if (err < 0)
                return err;
        }
    }

    return 1;
}

int auxtrace_mmap__read(struct auxtrace_mmap *mm, struct auxtrace_record *itr,
            struct perf_tool *tool, process_auxtrace_t fn)
{
    return __auxtrace_mmap__read(mm, itr, tool, fn, false, 0);
}

int auxtrace_mmap__read_snapshot(struct auxtrace_mmap *mm,
                 struct auxtrace_record *itr,
                 struct perf_tool *tool, process_auxtrace_t fn,
                 size_t snapshot_size)
{
    return __auxtrace_mmap__read(mm, itr, tool, fn, true, snapshot_size);
}

struct auxtrace_cache {
    struct hlist_head *hashtable;
    size_t sz;
    size_t entry_size;
    size_t limit;
    size_t cnt;
    unsigned int bits;
};

struct auxtrace_cache *auxtrace_cache__new(unsigned int bits, size_t entry_size,
                       unsigned int limit_percent)
{
    struct auxtrace_cache *c;
    struct hlist_head *ht;
    size_t sz, i;

    c = zalloc(sizeof(struct auxtrace_cache));
    if (!c)
        return NULL;

    sz = 1UL << bits;

    ht = calloc(sz, sizeof(struct hlist_head));
    if (!ht)
        goto out_free;

    for (i = 0; i < sz; i++)
        INIT_HLIST_HEAD(&ht[i]);

    c->hashtable = ht;
    c->sz = sz;
    c->entry_size = entry_size;
    c->limit = (c->sz * limit_percent) / 100;
    c->bits = bits;

    return c;

out_free:
    free(c);
    return NULL;
}

static void auxtrace_cache__drop(struct auxtrace_cache *c)
{
    struct auxtrace_cache_entry *entry;
    struct hlist_node *tmp;
    size_t i;

    if (!c)
        return;

    for (i = 0; i < c->sz; i++) {
        hlist_for_each_entry_safe(entry, tmp, &c->hashtable[i], hash) {
            hlist_del(&entry->hash);
            auxtrace_cache__free_entry(c, entry);
        }
    }

    c->cnt = 0;
}

void auxtrace_cache__free(struct auxtrace_cache *c)
{
    if (!c)
        return;

    auxtrace_cache__drop(c);
    free(c->hashtable);
    free(c);
}

void *auxtrace_cache__alloc_entry(struct auxtrace_cache *c)
{
    return malloc(c->entry_size);
}

void auxtrace_cache__free_entry(struct auxtrace_cache *c __maybe_unused,
                void *entry)
{
    free(entry);
}

int auxtrace_cache__add(struct auxtrace_cache *c, u32 key,
            struct auxtrace_cache_entry *entry)
{
    if (c->limit && ++c->cnt > c->limit)
        auxtrace_cache__drop(c);

    entry->key = key;
    hlist_add_head(&entry->hash, &c->hashtable[hash_32(key, c->bits)]);

    return 0;
}

void *auxtrace_cache__lookup(struct auxtrace_cache *c, u32 key)
{
    struct auxtrace_cache_entry *entry;
    struct hlist_head *hlist;

    if (!c)
        return NULL;

    hlist = &c->hashtable[hash_32(key, c->bits)];
    hlist_for_each_entry(entry, hlist, hash) {
        if (entry->key == key)
            return entry;
    }

    return NULL;
}

static void addr_filter__free_str(struct addr_filter *filt)
{
    free(filt->str);
    filt->action   = NULL;
    filt->sym_from = NULL;
    filt->sym_to   = NULL;
    filt->filename = NULL;
    filt->str      = NULL;
}

static struct addr_filter *addr_filter__new(void)
{
    struct addr_filter *filt = zalloc(sizeof(*filt));

    if (filt)
        INIT_LIST_HEAD(&filt->list);

    return filt;
}

static void addr_filter__free(struct addr_filter *filt)
{
    if (filt)
        addr_filter__free_str(filt);
    free(filt);
}

static void addr_filters__add(struct addr_filters *filts,
                  struct addr_filter *filt)
{
    list_add_tail(&filt->list, &filts->head);
    filts->cnt += 1;
}

static void addr_filters__del(struct addr_filters *filts,
                  struct addr_filter *filt)
{
    list_del_init(&filt->list);
    filts->cnt -= 1;
}

void addr_filters__init(struct addr_filters *filts)
{
    INIT_LIST_HEAD(&filts->head);
    filts->cnt = 0;
}

void addr_filters__exit(struct addr_filters *filts)
{
    struct addr_filter *filt, *n;

    list_for_each_entry_safe(filt, n, &filts->head, list) {
        addr_filters__del(filts, filt);
        addr_filter__free(filt);
    }
}

static int parse_num_or_str(char **inp, u64 *num, const char **str,
                const char *str_delim)
{
    *inp += strspn(*inp, " ");

    if (isdigit(**inp)) {
        char *endptr;

        if (!num)
            return -EINVAL;
        errno = 0;
        *num = strtoull(*inp, &endptr, 0);
        if (errno)
            return -errno;
        if (endptr == *inp)
            return -EINVAL;
        *inp = endptr;
    } else {
        size_t n;

        if (!str)
            return -EINVAL;
        *inp += strspn(*inp, " ");
        *str = *inp;
        n = strcspn(*inp, str_delim);
        if (!n)
            return -EINVAL;
        *inp += n;
        if (**inp) {
            **inp = '\0';
            *inp += 1;
        }
    }
    return 0;
}

static int parse_action(struct addr_filter *filt)
{
    if (!strcmp(filt->action, "filter")) {
        filt->start = true;
        filt->range = true;
    } else if (!strcmp(filt->action, "start")) {
        filt->start = true;
    } else if (!strcmp(filt->action, "stop")) {
        filt->start = false;
    } else if (!strcmp(filt->action, "tracestop")) {
        filt->start = false;
        filt->range = true;
        filt->action += 5; /* Change 'tracestop' to 'stop' */
    } else {
        return -EINVAL;
    }
    return 0;
}

static int parse_sym_idx(char **inp, int *idx)
{
    *idx = -1;

    *inp += strspn(*inp, " ");

    if (**inp != '#')
        return 0;

    *inp += 1;

    if (**inp == 'g' || **inp == 'G') {
        *inp += 1;
        *idx = 0;
    } else {
        unsigned long num;
        char *endptr;

        errno = 0;
        num = strtoul(*inp, &endptr, 0);
        if (errno)
            return -errno;
        if (endptr == *inp || num > INT_MAX)
            return -EINVAL;
        *inp = endptr;
        *idx = num;
    }

    return 0;
}

static int parse_addr_size(char **inp, u64 *num, const char **str, int *idx)
{
    int err = parse_num_or_str(inp, num, str, " ");

    if (!err && *str)
        err = parse_sym_idx(inp, idx);

    return err;
}

static int parse_one_filter(struct addr_filter *filt, const char **filter_inp)
{
    char *fstr;
    int err;

    filt->str = fstr = strdup(*filter_inp);
    if (!fstr)
        return -ENOMEM;

    err = parse_num_or_str(&fstr, NULL, &filt->action, " ");
    if (err)
        goto out_err;

    err = parse_action(filt);
    if (err)
        goto out_err;

    err = parse_addr_size(&fstr, &filt->addr, &filt->sym_from,
                  &filt->sym_from_idx);
    if (err)
        goto out_err;

    fstr += strspn(fstr, " ");

    if (*fstr == '/') {
        fstr += 1;
        err = parse_addr_size(&fstr, &filt->size, &filt->sym_to,
                      &filt->sym_to_idx);
        if (err)
            goto out_err;
        filt->range = true;
    }

    fstr += strspn(fstr, " ");

    if (*fstr == '@') {
        fstr += 1;
        err = parse_num_or_str(&fstr, NULL, &filt->filename, " ,");
        if (err)
            goto out_err;
    }

    fstr += strspn(fstr, " ,");

    *filter_inp += fstr - filt->str;

    return 0;

out_err:
    addr_filter__free_str(filt);

    return err;
}

int addr_filters__parse_bare_filter(struct addr_filters *filts,
                    const char *filter)
{
    struct addr_filter *filt;
    const char *fstr = filter;
    int err;

    while (*fstr) {
        filt = addr_filter__new();
        err = parse_one_filter(filt, &fstr);
        if (err) {
            addr_filter__free(filt);
            addr_filters__exit(filts);
            return err;
        }
        addr_filters__add(filts, filt);
    }

    return 0;
}

struct sym_args {
    const char  *name;
    u64     start;
    u64     size;
    int     idx;
    int     cnt;
    bool        started;
    bool        global;
    bool        selected;
    bool        duplicate;
    bool        near;
};

static bool kern_sym_match(struct sym_args *args, const char *name, char type)
{
    /* A function with the same name, and global or the n'th found or any */
    return kallsyms__is_function(type) &&
           !strcmp(name, args->name) &&
           ((args->global && isupper(type)) ||
        (args->selected && ++(args->cnt) == args->idx) ||
        (!args->global && !args->selected));
}

static int find_kern_sym_cb(void *arg, const char *name, char type, u64 start)
{
    struct sym_args *args = arg;

    if (args->started) {
        if (!args->size)
            args->size = start - args->start;
        if (args->selected) {
            if (args->size)
                return 1;
        } else if (kern_sym_match(args, name, type)) {
            args->duplicate = true;
            return 1;
        }
    } else if (kern_sym_match(args, name, type)) {
        args->started = true;
        args->start = start;
    }

    return 0;
}

static int print_kern_sym_cb(void *arg, const char *name, char type, u64 start)
{
    struct sym_args *args = arg;

    if (kern_sym_match(args, name, type)) {
        pr_err("#%d\t0x%"PRIx64"\t%c\t%s\n",
               ++args->cnt, start, type, name);
        args->near = true;
    } else if (args->near) {
        args->near = false;
        pr_err("\t\twhich is near\t\t%s\n", name);
    }

    return 0;
}

static int sym_not_found_error(const char *sym_name, int idx)
{
    if (idx > 0) {
        pr_err("N'th occurrence (N=%d) of symbol '%s' not found.\n",
               idx, sym_name);
    } else if (!idx) {
        pr_err("Global symbol '%s' not found.\n", sym_name);
    } else {
        pr_err("Symbol '%s' not found.\n", sym_name);
    }
    pr_err("Note that symbols must be functions.\n");

    return -EINVAL;
}

static int find_kern_sym(const char *sym_name, u64 *start, u64 *size, int idx)
{
    struct sym_args args = {
        .name = sym_name,
        .idx = idx,
        .global = !idx,
        .selected = idx > 0,
    };
    int err;

    *start = 0;
    *size = 0;

    err = kallsyms__parse("/proc/kallsyms", &args, find_kern_sym_cb);
    if (err < 0) {
        pr_err("Failed to parse /proc/kallsyms\n");
        return err;
    }

    if (args.duplicate) {
        pr_err("Multiple kernel symbols with name '%s'\n", sym_name);
        args.cnt = 0;
        kallsyms__parse("/proc/kallsyms", &args, print_kern_sym_cb);
        pr_err("Disambiguate symbol name by inserting #n after the name e.g. %s #2\n",
               sym_name);
        pr_err("Or select a global symbol by inserting #0 or #g or #G\n");
        return -EINVAL;
    }

    if (!args.started) {
        pr_err("Kernel symbol lookup: ");
        return sym_not_found_error(sym_name, idx);
    }

    *start = args.start;
    *size = args.size;

    return 0;
}

static int find_entire_kern_cb(void *arg, const char *name __maybe_unused,
                   char type, u64 start)
{
    struct sym_args *args = arg;

    if (!kallsyms__is_function(type))
        return 0;

    if (!args->started) {
        args->started = true;
        args->start = start;
    }
    /* Don't know exactly where the kernel ends, so we add a page */
    args->size = round_up(start, page_size) + page_size - args->start;

    return 0;
}

static int addr_filter__entire_kernel(struct addr_filter *filt)
{
    struct sym_args args = { .started = false };
    int err;

    err = kallsyms__parse("/proc/kallsyms", &args, find_entire_kern_cb);
    if (err < 0 || !args.started) {
        pr_err("Failed to parse /proc/kallsyms\n");
        return err;
    }

    filt->addr = args.start;
    filt->size = args.size;

    return 0;
}

static int check_end_after_start(struct addr_filter *filt, u64 start, u64 size)
{
    if (start + size >= filt->addr)
        return 0;

    if (filt->sym_from) {
        pr_err("Symbol '%s' (0x%"PRIx64") comes before '%s' (0x%"PRIx64")\n",
               filt->sym_to, start, filt->sym_from, filt->addr);
    } else {
        pr_err("Symbol '%s' (0x%"PRIx64") comes before address 0x%"PRIx64")\n",
               filt->sym_to, start, filt->addr);
    }

    return -EINVAL;
}

static int addr_filter__resolve_kernel_syms(struct addr_filter *filt)
{
    bool no_size = false;
    u64 start, size;
    int err;

    if (symbol_conf.kptr_restrict) {
        pr_err("Kernel addresses are restricted. Unable to resolve kernel symbols.\n");
        return -EINVAL;
    }

    if (filt->sym_from && !strcmp(filt->sym_from, "*"))
        return addr_filter__entire_kernel(filt);

    if (filt->sym_from) {
        err = find_kern_sym(filt->sym_from, &start, &size,
                    filt->sym_from_idx);
        if (err)
            return err;
        filt->addr = start;
        if (filt->range && !filt->size && !filt->sym_to) {
            filt->size = size;
            no_size = !size;
        }
    }

    if (filt->sym_to) {
        err = find_kern_sym(filt->sym_to, &start, &size,
                    filt->sym_to_idx);
        if (err)
            return err;

        err = check_end_after_start(filt, start, size);
        if (err)
            return err;
        filt->size = start + size - filt->addr;
        no_size = !size;
    }

    /* The very last symbol in kallsyms does not imply a particular size */
    if (no_size) {
        pr_err("Cannot determine size of symbol '%s'\n",
               filt->sym_to ? filt->sym_to : filt->sym_from);
        return -EINVAL;
    }

    return 0;
}

static struct dso *load_dso(const char *name)
{
    struct map *map;
    struct dso *dso;

    map = dso__new_map(name);
    if (!map)
        return NULL;

    map__load(map);

    dso = dso__get(map->dso);

    map__put(map);

    return dso;
}

static bool dso_sym_match(struct symbol *sym, const char *name, int *cnt,
              int idx)
{
    /* Same name, and global or the n'th found or any */
    return !arch__compare_symbol_names(name, sym->name) &&
           ((!idx && sym->binding == STB_GLOBAL) ||
        (idx > 0 && ++*cnt == idx) ||
        idx < 0);
}

static void print_duplicate_syms(struct dso *dso, const char *sym_name)
{
    struct symbol *sym;
    bool near = false;
    int cnt = 0;

    pr_err("Multiple symbols with name '%s'\n", sym_name);

    sym = dso__first_symbol(dso);
    while (sym) {
        if (dso_sym_match(sym, sym_name, &cnt, -1)) {
            pr_err("#%d\t0x%"PRIx64"\t%c\t%s\n",
                   ++cnt, sym->start,
                   sym->binding == STB_GLOBAL ? 'g' :
                   sym->binding == STB_LOCAL  ? 'l' : 'w',
                   sym->name);
            near = true;
        } else if (near) {
            near = false;
            pr_err("\t\twhich is near\t\t%s\n", sym->name);
        }
        sym = dso__next_symbol(sym);
    }

    pr_err("Disambiguate symbol name by inserting #n after the name e.g. %s #2\n",
           sym_name);
    pr_err("Or select a global symbol by inserting #0 or #g or #G\n");
}

static int find_dso_sym(struct dso *dso, const char *sym_name, u64 *start,
            u64 *size, int idx)
{
    struct symbol *sym;
    int cnt = 0;

    *start = 0;
    *size = 0;

    sym = dso__first_symbol(dso);
    while (sym) {
        if (*start) {
            if (!*size)
                *size = sym->start - *start;
            if (idx > 0) {
                if (*size)
                    return 1;
            } else if (dso_sym_match(sym, sym_name, &cnt, idx)) {
                print_duplicate_syms(dso, sym_name);
                return -EINVAL;
            }
        } else if (dso_sym_match(sym, sym_name, &cnt, idx)) {
            *start = sym->start;
            *size = sym->end - sym->start;
        }
        sym = dso__next_symbol(sym);
    }

    if (!*start)
        return sym_not_found_error(sym_name, idx);

    return 0;
}

static int addr_filter__entire_dso(struct addr_filter *filt, struct dso *dso)
{
    struct symbol *first_sym = dso__first_symbol(dso);
    struct symbol *last_sym = dso__last_symbol(dso);

    if (!first_sym || !last_sym) {
        pr_err("Failed to determine filter for %s\nNo symbols found.\n",
               filt->filename);
        return -EINVAL;
    }

    filt->addr = first_sym->start;
    filt->size = last_sym->end - first_sym->start;

    return 0;
}

static int addr_filter__resolve_syms(struct addr_filter *filt)
{
    u64 start, size;
    struct dso *dso;
    int err = 0;

    if (!filt->sym_from && !filt->sym_to)
        return 0;

    if (!filt->filename)
        return addr_filter__resolve_kernel_syms(filt);

    dso = load_dso(filt->filename);
    if (!dso) {
        pr_err("Failed to load symbols from: %s\n", filt->filename);
        return -EINVAL;
    }

    if (filt->sym_from && !strcmp(filt->sym_from, "*")) {
        err = addr_filter__entire_dso(filt, dso);
        goto put_dso;
    }

    if (filt->sym_from) {
        err = find_dso_sym(dso, filt->sym_from, &start, &size,
                   filt->sym_from_idx);
        if (err)
            goto put_dso;
        filt->addr = start;
        if (filt->range && !filt->size && !filt->sym_to)
            filt->size = size;
    }

    if (filt->sym_to) {
        err = find_dso_sym(dso, filt->sym_to, &start, &size,
                   filt->sym_to_idx);
        if (err)
            goto put_dso;

        err = check_end_after_start(filt, start, size);
        if (err)
            return err;

        filt->size = start + size - filt->addr;
    }

put_dso:
    dso__put(dso);

    return err;
}

static char *addr_filter__to_str(struct addr_filter *filt)
{
    char filename_buf[PATH_MAX];
    const char *at = "";
    const char *fn = "";
    char *filter;
    int err;

    if (filt->filename) {
        at = "@";
        fn = realpath(filt->filename, filename_buf);
        if (!fn)
            return NULL;
    }

    if (filt->range) {
        err = asprintf(&filter, "%s 0x%"PRIx64"/0x%"PRIx64"%s%s",
                   filt->action, filt->addr, filt->size, at, fn);
    } else {
        err = asprintf(&filter, "%s 0x%"PRIx64"%s%s",
                   filt->action, filt->addr, at, fn);
    }

    return err < 0 ? NULL : filter;
}

static int parse_addr_filter(struct perf_evsel *evsel, const char *filter,
                 int max_nr)
{
    struct addr_filters filts;
    struct addr_filter *filt;
    int err;

    addr_filters__init(&filts);

    err = addr_filters__parse_bare_filter(&filts, filter);
    if (err)
        goto out_exit;

    if (filts.cnt > max_nr) {
        pr_err("Error: number of address filters (%d) exceeds maximum (%d)\n",
               filts.cnt, max_nr);
        err = -EINVAL;
        goto out_exit;
    }

    list_for_each_entry(filt, &filts.head, list) {
        char *new_filter;

        err = addr_filter__resolve_syms(filt);
        if (err)
            goto out_exit;

        new_filter = addr_filter__to_str(filt);
        if (!new_filter) {
            err = -ENOMEM;
            goto out_exit;
        }

        if (perf_evsel__append_addr_filter(evsel, new_filter)) {
            err = -ENOMEM;
            goto out_exit;
        }
    }

out_exit:
    addr_filters__exit(&filts);

    if (err) {
        pr_err("Failed to parse address filter: '%s'\n", filter);
        pr_err("Filter format is: filter|start|stop|tracestop <start symbol or address> [/ <end symbol or size>] [@<file name>]\n");
        pr_err("Where multiple filters are separated by space or comma.\n");
    }

    return err;
}

static struct perf_pmu *perf_evsel__find_pmu(struct perf_evsel *evsel)
{
    struct perf_pmu *pmu = NULL;

    while ((pmu = perf_pmu__scan(pmu)) != NULL) {
        if (pmu->type == evsel->attr.type)
            break;
    }

    return pmu;
}

static int perf_evsel__nr_addr_filter(struct perf_evsel *evsel)
{
    struct perf_pmu *pmu = perf_evsel__find_pmu(evsel);
    int nr_addr_filters = 0;

    if (!pmu)
        return 0;

    perf_pmu__scan_file(pmu, "nr_addr_filters", "%d", &nr_addr_filters);

    return nr_addr_filters;
}

int auxtrace_parse_filters(struct perf_evlist *evlist)
{
    struct perf_evsel *evsel;
    char *filter;
    int err, max_nr;

    evlist__for_each_entry(evlist, evsel) {
        filter = evsel->filter;
        max_nr = perf_evsel__nr_addr_filter(evsel);
        if (!filter || !max_nr)
            continue;
        evsel->filter = NULL;
        err = parse_addr_filter(evsel, filter, max_nr);
        free(filter);
        if (err)
            return err;
        pr_debug("Address filter: %s\n", evsel->filter);
    }

    return 0;
}