1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * Test backward bit in event attribute, read ring buffer from end to |
4 | * beginning |
5 | */ |
6 | |
7 | #include <evlist.h> |
8 | #include <sys/prctl.h> |
9 | #include "record.h" |
10 | #include "tests.h" |
11 | #include "debug.h" |
12 | #include "parse-events.h" |
13 | #include "util/mmap.h" |
14 | #include <errno.h> |
15 | #include <linux/string.h> |
16 | #include <perf/mmap.h> |
17 | |
18 | #define NR_ITERS 111 |
19 | |
20 | static void testcase(void) |
21 | { |
22 | int i; |
23 | |
24 | for (i = 0; i < NR_ITERS; i++) { |
25 | char proc_name[15]; |
26 | |
27 | snprintf(proc_name, sizeof(proc_name), "p:%d\n" , i); |
28 | prctl(PR_SET_NAME, proc_name); |
29 | } |
30 | } |
31 | |
32 | static int count_samples(struct evlist *evlist, int *sample_count, |
33 | int *comm_count) |
34 | { |
35 | int i; |
36 | |
37 | for (i = 0; i < evlist->core.nr_mmaps; i++) { |
38 | struct mmap *map = &evlist->overwrite_mmap[i]; |
39 | union perf_event *event; |
40 | |
41 | perf_mmap__read_init(&map->core); |
42 | while ((event = perf_mmap__read_event(&map->core)) != NULL) { |
43 | const u32 type = event->header.type; |
44 | |
45 | switch (type) { |
46 | case PERF_RECORD_SAMPLE: |
47 | (*sample_count)++; |
48 | break; |
49 | case PERF_RECORD_COMM: |
50 | (*comm_count)++; |
51 | break; |
52 | default: |
53 | pr_err("Unexpected record of type %d\n" , type); |
54 | return TEST_FAIL; |
55 | } |
56 | } |
57 | perf_mmap__read_done(&map->core); |
58 | } |
59 | return TEST_OK; |
60 | } |
61 | |
62 | static int do_test(struct evlist *evlist, int mmap_pages, |
63 | int *sample_count, int *comm_count) |
64 | { |
65 | int err; |
66 | char sbuf[STRERR_BUFSIZE]; |
67 | |
68 | err = evlist__mmap(evlist, mmap_pages); |
69 | if (err < 0) { |
70 | pr_debug("evlist__mmap: %s\n" , |
71 | str_error_r(errno, sbuf, sizeof(sbuf))); |
72 | return TEST_FAIL; |
73 | } |
74 | |
75 | evlist__enable(evlist); |
76 | testcase(); |
77 | evlist__disable(evlist); |
78 | |
79 | err = count_samples(evlist, sample_count, comm_count); |
80 | evlist__munmap(evlist); |
81 | return err; |
82 | } |
83 | |
84 | |
85 | static int test__backward_ring_buffer(struct test_suite *test __maybe_unused, int subtest __maybe_unused) |
86 | { |
87 | int ret = TEST_SKIP, err, sample_count = 0, comm_count = 0; |
88 | char pid[16], sbuf[STRERR_BUFSIZE]; |
89 | struct evlist *evlist; |
90 | struct evsel *evsel __maybe_unused; |
91 | struct parse_events_error parse_error; |
92 | struct record_opts opts = { |
93 | .target = { |
94 | .uid = UINT_MAX, |
95 | .uses_mmap = true, |
96 | }, |
97 | .freq = 0, |
98 | .mmap_pages = 256, |
99 | .default_interval = 1, |
100 | }; |
101 | |
102 | snprintf(pid, sizeof(pid), "%d" , getpid()); |
103 | pid[sizeof(pid) - 1] = '\0'; |
104 | opts.target.tid = opts.target.pid = pid; |
105 | |
106 | evlist = evlist__new(); |
107 | if (!evlist) { |
108 | pr_debug("Not enough memory to create evlist\n" ); |
109 | return TEST_FAIL; |
110 | } |
111 | |
112 | err = evlist__create_maps(evlist, &opts.target); |
113 | if (err < 0) { |
114 | pr_debug("Not enough memory to create thread/cpu maps\n" ); |
115 | goto out_delete_evlist; |
116 | } |
117 | |
118 | parse_events_error__init(&parse_error); |
119 | /* |
120 | * Set backward bit, ring buffer should be writing from end. Record |
121 | * it in aux evlist |
122 | */ |
123 | err = parse_events(evlist, "syscalls:sys_enter_prctl/overwrite/" , &parse_error); |
124 | parse_events_error__exit(&parse_error); |
125 | if (err) { |
126 | pr_debug("Failed to parse tracepoint event, try use root\n" ); |
127 | ret = TEST_SKIP; |
128 | goto out_delete_evlist; |
129 | } |
130 | |
131 | evlist__config(evlist, &opts, NULL); |
132 | |
133 | err = evlist__open(evlist); |
134 | if (err < 0) { |
135 | pr_debug("perf_evlist__open: %s\n" , |
136 | str_error_r(errno, sbuf, sizeof(sbuf))); |
137 | goto out_delete_evlist; |
138 | } |
139 | |
140 | ret = TEST_FAIL; |
141 | err = do_test(evlist, mmap_pages: opts.mmap_pages, sample_count: &sample_count, |
142 | comm_count: &comm_count); |
143 | if (err != TEST_OK) |
144 | goto out_delete_evlist; |
145 | |
146 | if ((sample_count != NR_ITERS) || (comm_count != NR_ITERS)) { |
147 | pr_err("Unexpected counter: sample_count=%d, comm_count=%d\n" , |
148 | sample_count, comm_count); |
149 | goto out_delete_evlist; |
150 | } |
151 | |
152 | evlist__close(evlist); |
153 | |
154 | err = evlist__open(evlist); |
155 | if (err < 0) { |
156 | pr_debug("perf_evlist__open: %s\n" , |
157 | str_error_r(errno, sbuf, sizeof(sbuf))); |
158 | goto out_delete_evlist; |
159 | } |
160 | |
161 | err = do_test(evlist, mmap_pages: 1, sample_count: &sample_count, comm_count: &comm_count); |
162 | if (err != TEST_OK) |
163 | goto out_delete_evlist; |
164 | |
165 | ret = TEST_OK; |
166 | out_delete_evlist: |
167 | evlist__delete(evlist); |
168 | return ret; |
169 | } |
170 | |
171 | DEFINE_SUITE("Read backward ring buffer" , backward_ring_buffer); |
172 | |