// SPDX-License-Identifier: GPL-2.0
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/*
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* Test backward bit in event attribute, read ring buffer from end to
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* beginning
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*/
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#include <perf.h>
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#include <evlist.h>
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#include <sys/prctl.h>
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#include "tests.h"
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#include "debug.h"
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#include <errno.h>
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#define NR_ITERS 111
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static void testcase(void)
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{
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int i;
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for (i = 0; i < NR_ITERS; i++) {
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char proc_name[10];
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snprintf(proc_name, sizeof(proc_name), "p:%d\n", i);
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prctl(PR_SET_NAME, proc_name);
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}
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}
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static int count_samples(struct perf_evlist *evlist, int *sample_count,
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int *comm_count)
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{
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int i;
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for (i = 0; i < evlist->nr_mmaps; i++) {
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struct perf_mmap *map = &evlist->overwrite_mmap[i];
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union perf_event *event;
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perf_mmap__read_init(map);
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while ((event = perf_mmap__read_event(map)) != NULL) {
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const u32 type = event->header.type;
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switch (type) {
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case PERF_RECORD_SAMPLE:
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(*sample_count)++;
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break;
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case PERF_RECORD_COMM:
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(*comm_count)++;
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break;
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default:
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pr_err("Unexpected record of type %d\n", type);
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return TEST_FAIL;
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}
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}
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perf_mmap__read_done(map);
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}
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return TEST_OK;
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}
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static int do_test(struct perf_evlist *evlist, int mmap_pages,
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int *sample_count, int *comm_count)
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{
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int err;
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char sbuf[STRERR_BUFSIZE];
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err = perf_evlist__mmap(evlist, mmap_pages);
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if (err < 0) {
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pr_debug("perf_evlist__mmap: %s\n",
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str_error_r(errno, sbuf, sizeof(sbuf)));
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return TEST_FAIL;
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}
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perf_evlist__enable(evlist);
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testcase();
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perf_evlist__disable(evlist);
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err = count_samples(evlist, sample_count, comm_count);
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perf_evlist__munmap(evlist);
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return err;
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}
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int test__backward_ring_buffer(struct test *test __maybe_unused, int subtest __maybe_unused)
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{
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int ret = TEST_SKIP, err, sample_count = 0, comm_count = 0;
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char pid[16], sbuf[STRERR_BUFSIZE];
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struct perf_evlist *evlist;
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struct perf_evsel *evsel __maybe_unused;
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struct parse_events_error parse_error;
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struct record_opts opts = {
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.target = {
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.uid = UINT_MAX,
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.uses_mmap = true,
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},
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.freq = 0,
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.mmap_pages = 256,
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.default_interval = 1,
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};
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snprintf(pid, sizeof(pid), "%d", getpid());
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pid[sizeof(pid) - 1] = '\0';
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opts.target.tid = opts.target.pid = pid;
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evlist = perf_evlist__new();
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if (!evlist) {
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pr_debug("Not enough memory to create evlist\n");
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return TEST_FAIL;
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}
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err = perf_evlist__create_maps(evlist, &opts.target);
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if (err < 0) {
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pr_debug("Not enough memory to create thread/cpu maps\n");
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goto out_delete_evlist;
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}
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bzero(&parse_error, sizeof(parse_error));
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/*
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* Set backward bit, ring buffer should be writing from end. Record
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* it in aux evlist
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*/
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err = parse_events(evlist, "syscalls:sys_enter_prctl/overwrite/", &parse_error);
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if (err) {
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pr_debug("Failed to parse tracepoint event, try use root\n");
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ret = TEST_SKIP;
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goto out_delete_evlist;
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}
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perf_evlist__config(evlist, &opts, NULL);
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err = perf_evlist__open(evlist);
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if (err < 0) {
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pr_debug("perf_evlist__open: %s\n",
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str_error_r(errno, sbuf, sizeof(sbuf)));
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goto out_delete_evlist;
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}
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ret = TEST_FAIL;
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err = do_test(evlist, opts.mmap_pages, &sample_count,
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&comm_count);
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if (err != TEST_OK)
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goto out_delete_evlist;
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if ((sample_count != NR_ITERS) || (comm_count != NR_ITERS)) {
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pr_err("Unexpected counter: sample_count=%d, comm_count=%d\n",
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sample_count, comm_count);
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goto out_delete_evlist;
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}
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err = do_test(evlist, 1, &sample_count, &comm_count);
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if (err != TEST_OK)
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goto out_delete_evlist;
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ret = TEST_OK;
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out_delete_evlist:
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perf_evlist__delete(evlist);
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return ret;
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}
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