openat-syscall-tp-fields.c

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// SPDX-License-Identifier: GPL-2.0
#include <linux/err.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include "perf.h"
#include "evlist.h"
#include "evsel.h"
#include "thread_map.h"
#include "tests.h"
#include "debug.h"
#include <errno.h>

#ifndef O_DIRECTORY
#define O_DIRECTORY    00200000
#endif
#ifndef AT_FDCWD
#define AT_FDCWD       -100
#endif

int test__syscall_openat_tp_fields(struct test *test __maybe_unused, int subtest __maybe_unused)
{
    struct record_opts opts = {
        .target = {
            .uid = UINT_MAX,
            .uses_mmap = true,
        },
        .no_buffering = true,
        .freq         = 1,
        .mmap_pages   = 256,
        .raw_samples  = true,
    };
    const char *filename = "/etc/passwd";
    int flags = O_RDONLY | O_DIRECTORY;
    struct perf_evlist *evlist = perf_evlist__new();
    struct perf_evsel *evsel;
    int err = -1, i, nr_events = 0, nr_polls = 0;
    char sbuf[STRERR_BUFSIZE];

    if (evlist == NULL) {
        pr_debug("%s: perf_evlist__new\n", __func__);
        goto out;
    }

    evsel = perf_evsel__newtp("syscalls", "sys_enter_openat");
    if (IS_ERR(evsel)) {
        pr_debug("%s: perf_evsel__newtp\n", __func__);
        goto out_delete_evlist;
    }

    perf_evlist__add(evlist, evsel);

    err = perf_evlist__create_maps(evlist, &opts.target);
    if (err < 0) {
        pr_debug("%s: perf_evlist__create_maps\n", __func__);
        goto out_delete_evlist;
    }

    perf_evsel__config(evsel, &opts, NULL);

    thread_map__set_pid(evlist->threads, 0, getpid());

    err = perf_evlist__open(evlist);
    if (err < 0) {
        pr_debug("perf_evlist__open: %s\n",
             str_error_r(errno, sbuf, sizeof(sbuf)));
        goto out_delete_evlist;
    }

    err = perf_evlist__mmap(evlist, UINT_MAX);
    if (err < 0) {
        pr_debug("perf_evlist__mmap: %s\n",
             str_error_r(errno, sbuf, sizeof(sbuf)));
        goto out_delete_evlist;
    }

    perf_evlist__enable(evlist);

    /*
     * Generate the event:
     */
    openat(AT_FDCWD, filename, flags);

    while (1) {
        int before = nr_events;

        for (i = 0; i < evlist->nr_mmaps; i++) {
            union perf_event *event;
            struct perf_mmap *md;

            md = &evlist->mmap[i];
            if (perf_mmap__read_init(md) < 0)
                continue;

            while ((event = perf_mmap__read_event(md)) != NULL) {
                const u32 type = event->header.type;
                int tp_flags;
                struct perf_sample sample;

                ++nr_events;

                if (type != PERF_RECORD_SAMPLE) {
                    perf_mmap__consume(md);
                    continue;
                }

                err = perf_evsel__parse_sample(evsel, event, &sample);
                if (err) {
                    pr_debug("Can't parse sample, err = %d\n", err);
                    goto out_delete_evlist;
                }

                tp_flags = perf_evsel__intval(evsel, &sample, "flags");

                if (flags != tp_flags) {
                    pr_debug("%s: Expected flags=%#x, got %#x\n",
                         __func__, flags, tp_flags);
                    goto out_delete_evlist;
                }

                goto out_ok;
            }
            perf_mmap__read_done(md);
        }

        if (nr_events == before)
            perf_evlist__poll(evlist, 10);

        if (++nr_polls > 5) {
            pr_debug("%s: no events!\n", __func__);
            goto out_delete_evlist;
        }
    }
out_ok:
    err = 0;
out_delete_evlist:
    perf_evlist__delete(evlist);
out:
    return err;
}