1 // SPDX-License-Identifier: GPL-2.0
3 * Test backward bit in event attribute, read ring buffer from end to
12 #include "parse-events.h"
14 #include <linux/string.h>
18 static void testcase(void)
22 for (i = 0; i < NR_ITERS; i++) {
25 snprintf(proc_name, sizeof(proc_name), "p:%d\n", i);
26 prctl(PR_SET_NAME, proc_name);
30 static int count_samples(struct evlist *evlist, int *sample_count,
35 for (i = 0; i < evlist->nr_mmaps; i++) {
36 struct perf_mmap *map = &evlist->overwrite_mmap[i];
37 union perf_event *event;
39 perf_mmap__read_init(map);
40 while ((event = perf_mmap__read_event(map)) != NULL) {
41 const u32 type = event->header.type;
44 case PERF_RECORD_SAMPLE:
47 case PERF_RECORD_COMM:
51 pr_err("Unexpected record of type %d\n", type);
55 perf_mmap__read_done(map);
60 static int do_test(struct evlist *evlist, int mmap_pages,
61 int *sample_count, int *comm_count)
64 char sbuf[STRERR_BUFSIZE];
66 err = perf_evlist__mmap(evlist, mmap_pages);
68 pr_debug("perf_evlist__mmap: %s\n",
69 str_error_r(errno, sbuf, sizeof(sbuf)));
73 evlist__enable(evlist);
75 evlist__disable(evlist);
77 err = count_samples(evlist, sample_count, comm_count);
78 perf_evlist__munmap(evlist);
83 int test__backward_ring_buffer(struct test *test __maybe_unused, int subtest __maybe_unused)
85 int ret = TEST_SKIP, err, sample_count = 0, comm_count = 0;
86 char pid[16], sbuf[STRERR_BUFSIZE];
87 struct evlist *evlist;
88 struct evsel *evsel __maybe_unused;
89 struct parse_events_error parse_error;
90 struct record_opts opts = {
97 .default_interval = 1,
100 snprintf(pid, sizeof(pid), "%d", getpid());
101 pid[sizeof(pid) - 1] = '\0';
102 opts.target.tid = opts.target.pid = pid;
104 evlist = evlist__new();
106 pr_debug("Not enough memory to create evlist\n");
110 err = perf_evlist__create_maps(evlist, &opts.target);
112 pr_debug("Not enough memory to create thread/cpu maps\n");
113 goto out_delete_evlist;
116 bzero(&parse_error, sizeof(parse_error));
118 * Set backward bit, ring buffer should be writing from end. Record
121 err = parse_events(evlist, "syscalls:sys_enter_prctl/overwrite/", &parse_error);
123 pr_debug("Failed to parse tracepoint event, try use root\n");
125 goto out_delete_evlist;
128 perf_evlist__config(evlist, &opts, NULL);
130 err = evlist__open(evlist);
132 pr_debug("perf_evlist__open: %s\n",
133 str_error_r(errno, sbuf, sizeof(sbuf)));
134 goto out_delete_evlist;
138 err = do_test(evlist, opts.mmap_pages, &sample_count,
141 goto out_delete_evlist;
143 if ((sample_count != NR_ITERS) || (comm_count != NR_ITERS)) {
144 pr_err("Unexpected counter: sample_count=%d, comm_count=%d\n",
145 sample_count, comm_count);
146 goto out_delete_evlist;
149 err = do_test(evlist, 1, &sample_count, &comm_count);
151 goto out_delete_evlist;
155 evlist__delete(evlist);