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"
13 #include "util/mmap.h"
15 #include <linux/string.h>
19 static void testcase(void)
23 for (i = 0; i < NR_ITERS; i++) {
26 snprintf(proc_name, sizeof(proc_name), "p:%d\n", i);
27 prctl(PR_SET_NAME, proc_name);
31 static int count_samples(struct evlist *evlist, int *sample_count,
36 for (i = 0; i < evlist->core.nr_mmaps; i++) {
37 struct mmap *map = &evlist->overwrite_mmap[i];
38 union perf_event *event;
40 perf_mmap__read_init(map);
41 while ((event = perf_mmap__read_event(map)) != NULL) {
42 const u32 type = event->header.type;
45 case PERF_RECORD_SAMPLE:
48 case PERF_RECORD_COMM:
52 pr_err("Unexpected record of type %d\n", type);
56 perf_mmap__read_done(map);
61 static int do_test(struct evlist *evlist, int mmap_pages,
62 int *sample_count, int *comm_count)
65 char sbuf[STRERR_BUFSIZE];
67 err = evlist__mmap(evlist, mmap_pages);
69 pr_debug("evlist__mmap: %s\n",
70 str_error_r(errno, sbuf, sizeof(sbuf)));
74 evlist__enable(evlist);
76 evlist__disable(evlist);
78 err = count_samples(evlist, sample_count, comm_count);
79 evlist__munmap(evlist);
84 int test__backward_ring_buffer(struct test *test __maybe_unused, int subtest __maybe_unused)
86 int ret = TEST_SKIP, err, sample_count = 0, comm_count = 0;
87 char pid[16], sbuf[STRERR_BUFSIZE];
88 struct evlist *evlist;
89 struct evsel *evsel __maybe_unused;
90 struct parse_events_error parse_error;
91 struct record_opts opts = {
98 .default_interval = 1,
101 snprintf(pid, sizeof(pid), "%d", getpid());
102 pid[sizeof(pid) - 1] = '\0';
103 opts.target.tid = opts.target.pid = pid;
105 evlist = evlist__new();
107 pr_debug("Not enough memory to create evlist\n");
111 err = perf_evlist__create_maps(evlist, &opts.target);
113 pr_debug("Not enough memory to create thread/cpu maps\n");
114 goto out_delete_evlist;
117 bzero(&parse_error, sizeof(parse_error));
119 * Set backward bit, ring buffer should be writing from end. Record
122 err = parse_events(evlist, "syscalls:sys_enter_prctl/overwrite/", &parse_error);
124 pr_debug("Failed to parse tracepoint event, try use root\n");
126 goto out_delete_evlist;
129 perf_evlist__config(evlist, &opts, NULL);
131 err = evlist__open(evlist);
133 pr_debug("perf_evlist__open: %s\n",
134 str_error_r(errno, sbuf, sizeof(sbuf)));
135 goto out_delete_evlist;
139 err = do_test(evlist, opts.mmap_pages, &sample_count,
142 goto out_delete_evlist;
144 if ((sample_count != NR_ITERS) || (comm_count != NR_ITERS)) {
145 pr_err("Unexpected counter: sample_count=%d, comm_count=%d\n",
146 sample_count, comm_count);
147 goto out_delete_evlist;
150 err = do_test(evlist, 1, &sample_count, &comm_count);
152 goto out_delete_evlist;
156 evlist__delete(evlist);