// SPDX-License-Identifier: GPL-2.0
/*
 * Test backward bit in event attribute, read ring buffer from end to
 * beginning
 */

#include <evlist.h>
#include <sys/prctl.h>
#include "record.h"
#include "tests.h"
#include "debug.h"
#include "parse-events.h"
#include "util/mmap.h"
#include <errno.h>
#include <linux/string.h>
#include <perf/mmap.h>

#define NR_ITERS 111

static void testcase(void)
{
        int i;

        for (i = 0; i < NR_ITERS; i++) {
                char proc_name[15];

                snprintf(proc_name, sizeof(proc_name), "p:%d\n", i);
                prctl(PR_SET_NAME, proc_name);
        }
}

static int count_samples(struct evlist *evlist, int *sample_count,
                         int *comm_count)
{
        int i;

        for (i = 0; i < evlist->core.nr_mmaps; i++) {
                struct mmap *map = &evlist->overwrite_mmap[i];
                union perf_event *event;

                perf_mmap__read_init(&map->core);
                while ((event = perf_mmap__read_event(&map->core)) != NULL) {
                        const u32 type = event->header.type;

                        switch (type) {
                        case PERF_RECORD_SAMPLE:
                                (*sample_count)++;
                                break;
                        case PERF_RECORD_COMM:
                                (*comm_count)++;
                                break;
                        default:
                                pr_err("Unexpected record of type %d\n", type);
                                return TEST_FAIL;
                        }
                }
                perf_mmap__read_done(&map->core);
        }
        return TEST_OK;
}

static int do_test(struct evlist *evlist, int mmap_pages,
                   int *sample_count, int *comm_count)
{
        int err;
        char sbuf[STRERR_BUFSIZE];

        err = evlist__mmap(evlist, mmap_pages);
        if (err < 0) {
                pr_debug("evlist__mmap: %s\n",
                         str_error_r(errno, sbuf, sizeof(sbuf)));
                return TEST_FAIL;
        }

        evlist__enable(evlist);
        testcase();
        evlist__disable(evlist);

        err = count_samples(evlist, sample_count, comm_count);
        evlist__munmap(evlist);
        return err;
}


static int test__backward_ring_buffer(struct test_suite *test __maybe_unused, int subtest __maybe_unused)
{
        int ret = TEST_SKIP, err, sample_count = 0, comm_count = 0;
        char pid[16], sbuf[STRERR_BUFSIZE];
        struct evlist *evlist;
        struct evsel *evsel __maybe_unused;
        struct parse_events_error parse_error;
        struct record_opts opts = {
                .target = {
                        .uses_mmap = true,
                },
                .freq         = 0,
                .mmap_pages   = 256,
                .default_interval = 1,
        };

        snprintf(pid, sizeof(pid), "%d", getpid());
        pid[sizeof(pid) - 1] = '\0';
        opts.target.tid = opts.target.pid = pid;

        evlist = evlist__new();
        if (!evlist) {
                pr_debug("Not enough memory to create evlist\n");
                return TEST_FAIL;
        }

        err = evlist__create_maps(evlist, &opts.target);
        if (err < 0) {
                pr_debug("Not enough memory to create thread/cpu maps\n");
                goto out_delete_evlist;
        }

        parse_events_error__init(&parse_error);
        /*
         * Set backward bit, ring buffer should be writing from end. Record
         * it in aux evlist
         */
        err = parse_events(evlist, "syscalls:sys_enter_prctl/overwrite/", &parse_error);
        parse_events_error__exit(&parse_error);
        if (err) {
                pr_debug("Failed to parse tracepoint event, try use root\n");
                ret = TEST_SKIP;
                goto out_delete_evlist;
        }

        evlist__config(evlist, &opts, NULL);

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

        ret = TEST_FAIL;
        err = do_test(evlist, opts.mmap_pages, &sample_count,
                      &comm_count);
        if (err != TEST_OK)
                goto out_delete_evlist;

        if ((sample_count != NR_ITERS) || (comm_count != NR_ITERS)) {
                pr_err("Unexpected counter: sample_count=%d, comm_count=%d\n",
                       sample_count, comm_count);
                goto out_delete_evlist;
        }

        evlist__close(evlist);

        err = 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 = do_test(evlist, 1, &sample_count, &comm_count);
        if (err != TEST_OK)
                goto out_delete_evlist;

        ret = TEST_OK;
out_delete_evlist:
        evlist__delete(evlist);
        return ret;
}

DEFINE_SUITE("Read backward ring buffer", backward_ring_buffer);