1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
|
// SPDX-License-Identifier: GPL-2.0
#define _GNU_SOURCE
#include <pthread.h>
#include <sched.h>
#include <sys/socket.h>
#include <test_progs.h>
#include "bpf/libbpf_internal.h"
#include "test_perf_branches.skel.h"
static void check_good_sample(struct test_perf_branches *skel)
{
int written_global = skel->bss->written_global_out;
int required_size = skel->bss->required_size_out;
int written_stack = skel->bss->written_stack_out;
int pbe_size = sizeof(struct perf_branch_entry);
int duration = 0;
if (CHECK(!skel->bss->valid, "output not valid",
"no valid sample from prog"))
return;
/*
* It's hard to validate the contents of the branch entries b/c it
* would require some kind of disassembler and also encoding the
* valid jump instructions for supported architectures. So just check
* the easy stuff for now.
*/
CHECK(required_size <= 0, "read_branches_size", "err %d\n", required_size);
CHECK(written_stack < 0, "read_branches_stack", "err %d\n", written_stack);
CHECK(written_stack % pbe_size != 0, "read_branches_stack",
"stack bytes written=%d not multiple of struct size=%d\n",
written_stack, pbe_size);
CHECK(written_global < 0, "read_branches_global", "err %d\n", written_global);
CHECK(written_global % pbe_size != 0, "read_branches_global",
"global bytes written=%d not multiple of struct size=%d\n",
written_global, pbe_size);
CHECK(written_global < written_stack, "read_branches_size",
"written_global=%d < written_stack=%d\n", written_global, written_stack);
}
static void check_bad_sample(struct test_perf_branches *skel)
{
int written_global = skel->bss->written_global_out;
int required_size = skel->bss->required_size_out;
int written_stack = skel->bss->written_stack_out;
int duration = 0;
if (CHECK(!skel->bss->valid, "output not valid",
"no valid sample from prog"))
return;
CHECK((required_size != -EINVAL && required_size != -ENOENT),
"read_branches_size", "err %d\n", required_size);
CHECK((written_stack != -EINVAL && written_stack != -ENOENT),
"read_branches_stack", "written %d\n", written_stack);
CHECK((written_global != -EINVAL && written_global != -ENOENT),
"read_branches_global", "written %d\n", written_global);
}
static void test_perf_branches_common(int perf_fd,
void (*cb)(struct test_perf_branches *))
{
struct test_perf_branches *skel;
int err, i, duration = 0;
bool detached = false;
struct bpf_link *link;
volatile int j = 0;
cpu_set_t cpu_set;
skel = test_perf_branches__open_and_load();
if (CHECK(!skel, "test_perf_branches_load",
"perf_branches skeleton failed\n"))
return;
/* attach perf_event */
link = bpf_program__attach_perf_event(skel->progs.perf_branches, perf_fd);
if (!ASSERT_OK_PTR(link, "attach_perf_event"))
goto out_destroy_skel;
/* generate some branches on cpu 0 */
CPU_ZERO(&cpu_set);
CPU_SET(0, &cpu_set);
err = pthread_setaffinity_np(pthread_self(), sizeof(cpu_set), &cpu_set);
if (CHECK(err, "set_affinity", "cpu #0, err %d\n", err))
goto out_destroy;
/* spin the loop for a while (random high number) */
for (i = 0; i < 1000000; ++i)
++j;
test_perf_branches__detach(skel);
detached = true;
cb(skel);
out_destroy:
bpf_link__destroy(link);
out_destroy_skel:
if (!detached)
test_perf_branches__detach(skel);
test_perf_branches__destroy(skel);
}
static void test_perf_branches_hw(void)
{
struct perf_event_attr attr = {0};
int duration = 0;
int pfd;
/* create perf event */
attr.size = sizeof(attr);
attr.type = PERF_TYPE_HARDWARE;
attr.config = PERF_COUNT_HW_CPU_CYCLES;
attr.freq = 1;
attr.sample_freq = 4000;
attr.sample_type = PERF_SAMPLE_BRANCH_STACK;
attr.branch_sample_type = PERF_SAMPLE_BRANCH_USER | PERF_SAMPLE_BRANCH_ANY;
pfd = syscall(__NR_perf_event_open, &attr, -1, 0, -1, PERF_FLAG_FD_CLOEXEC);
/*
* Some setups don't support branch records (virtual machines, !x86),
* so skip test in this case.
*/
if (pfd < 0) {
if (errno == ENOENT || errno == EOPNOTSUPP) {
printf("%s:SKIP:no PERF_SAMPLE_BRANCH_STACK\n",
__func__);
test__skip();
return;
}
if (CHECK(pfd < 0, "perf_event_open", "err %d errno %d\n",
pfd, errno))
return;
}
test_perf_branches_common(pfd, check_good_sample);
close(pfd);
}
/*
* Tests negative case -- run bpf_read_branch_records() on improperly configured
* perf event.
*/
static void test_perf_branches_no_hw(void)
{
struct perf_event_attr attr = {0};
int duration = 0;
int pfd;
/* create perf event */
attr.size = sizeof(attr);
attr.type = PERF_TYPE_SOFTWARE;
attr.config = PERF_COUNT_SW_CPU_CLOCK;
attr.freq = 1;
attr.sample_freq = 4000;
pfd = syscall(__NR_perf_event_open, &attr, -1, 0, -1, PERF_FLAG_FD_CLOEXEC);
if (CHECK(pfd < 0, "perf_event_open", "err %d\n", pfd))
return;
test_perf_branches_common(pfd, check_bad_sample);
close(pfd);
}
void test_perf_branches(void)
{
if (test__start_subtest("perf_branches_hw"))
test_perf_branches_hw();
if (test__start_subtest("perf_branches_no_hw"))
test_perf_branches_no_hw();
}
|
