1
2#include <test_progs.h>
3#include "test_stacktrace_build_id.skel.h"
4
5static __u64 read_perf_max_sample_freq(void)
6{
7 __u64 sample_freq = 5000;
8 FILE *f;
9 __u32 duration = 0;
10
11 f = fopen("/proc/sys/kernel/perf_event_max_sample_rate", "r");
12 if (f == NULL)
13 return sample_freq;
14 CHECK(fscanf(f, "%llu", &sample_freq) != 1, "Get max sample rate",
15 "return default value: 5000,err %d\n", -errno);
16 fclose(f);
17 return sample_freq;
18}
19
20void test_stacktrace_build_id_nmi(void)
21{
22 int control_map_fd, stackid_hmap_fd, stackmap_fd;
23 struct test_stacktrace_build_id *skel;
24 int err, pmu_fd;
25 struct perf_event_attr attr = {
26 .freq = 1,
27 .type = PERF_TYPE_HARDWARE,
28 .config = PERF_COUNT_HW_CPU_CYCLES,
29 };
30 __u32 key, previous_key, val, duration = 0;
31 char buf[256];
32 int i, j;
33 struct bpf_stack_build_id id_offs[PERF_MAX_STACK_DEPTH];
34 int build_id_matches = 0;
35 int retry = 1;
36
37 attr.sample_freq = read_perf_max_sample_freq();
38
39retry:
40 skel = test_stacktrace_build_id__open();
41 if (CHECK(!skel, "skel_open", "skeleton open failed\n"))
42 return;
43
44
45 bpf_program__set_perf_event(skel->progs.oncpu);
46
47 err = test_stacktrace_build_id__load(skel);
48 if (CHECK(err, "skel_load", "skeleton load failed: %d\n", err))
49 goto cleanup;
50
51 pmu_fd = syscall(__NR_perf_event_open, &attr, -1 ,
52 0 , -1 ,
53 0 );
54 if (pmu_fd < 0 && errno == ENOENT) {
55 printf("%s:SKIP:no PERF_COUNT_HW_CPU_CYCLES\n", __func__);
56 test__skip();
57 goto cleanup;
58 }
59 if (CHECK(pmu_fd < 0, "perf_event_open", "err %d errno %d\n",
60 pmu_fd, errno))
61 goto cleanup;
62
63 skel->links.oncpu = bpf_program__attach_perf_event(skel->progs.oncpu,
64 pmu_fd);
65 if (CHECK(IS_ERR(skel->links.oncpu), "attach_perf_event",
66 "err %ld\n", PTR_ERR(skel->links.oncpu))) {
67 close(pmu_fd);
68 goto cleanup;
69 }
70
71
72 control_map_fd = bpf_map__fd(skel->maps.control_map);
73 stackid_hmap_fd = bpf_map__fd(skel->maps.stackid_hmap);
74 stackmap_fd = bpf_map__fd(skel->maps.stackmap);
75
76 if (CHECK_FAIL(system("dd if=/dev/urandom of=/dev/zero count=4 2> /dev/null")))
77 goto cleanup;
78 if (CHECK_FAIL(system("taskset 0x1 ./urandom_read 100000")))
79 goto cleanup;
80
81 key = 0;
82 val = 1;
83 bpf_map_update_elem(control_map_fd, &key, &val, 0);
84
85
86
87
88 err = compare_map_keys(stackid_hmap_fd, stackmap_fd);
89 if (CHECK(err, "compare_map_keys stackid_hmap vs. stackmap",
90 "err %d errno %d\n", err, errno))
91 goto cleanup;
92
93 err = compare_map_keys(stackmap_fd, stackid_hmap_fd);
94 if (CHECK(err, "compare_map_keys stackmap vs. stackid_hmap",
95 "err %d errno %d\n", err, errno))
96 goto cleanup;
97
98 err = extract_build_id(buf, 256);
99
100 if (CHECK(err, "get build_id with readelf",
101 "err %d errno %d\n", err, errno))
102 goto cleanup;
103
104 err = bpf_map_get_next_key(stackmap_fd, NULL, &key);
105 if (CHECK(err, "get_next_key from stackmap",
106 "err %d, errno %d\n", err, errno))
107 goto cleanup;
108
109 do {
110 char build_id[64];
111
112 err = bpf_map_lookup_elem(stackmap_fd, &key, id_offs);
113 if (CHECK(err, "lookup_elem from stackmap",
114 "err %d, errno %d\n", err, errno))
115 goto cleanup;
116 for (i = 0; i < PERF_MAX_STACK_DEPTH; ++i)
117 if (id_offs[i].status == BPF_STACK_BUILD_ID_VALID &&
118 id_offs[i].offset != 0) {
119 for (j = 0; j < 20; ++j)
120 sprintf(build_id + 2 * j, "%02x",
121 id_offs[i].build_id[j] & 0xff);
122 if (strstr(buf, build_id) != NULL)
123 build_id_matches = 1;
124 }
125 previous_key = key;
126 } while (bpf_map_get_next_key(stackmap_fd, &previous_key, &key) == 0);
127
128
129
130
131
132 if (build_id_matches < 1 && retry--) {
133 test_stacktrace_build_id__destroy(skel);
134 printf("%s:WARN:Didn't find expected build ID from the map, retrying\n",
135 __func__);
136 goto retry;
137 }
138
139 if (CHECK(build_id_matches < 1, "build id match",
140 "Didn't find expected build ID from the map\n"))
141 goto cleanup;
142
143
144
145
146
147
148
149
150cleanup:
151 test_stacktrace_build_id__destroy(skel);
152}
153