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
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
|
// SPDX-License-Identifier: GPL-2.0
#include <test_progs.h>
#include <sys/time.h>
#include <sys/resource.h>
#include "test_send_signal_kern.skel.h"
int sigusr1_received = 0;
static void sigusr1_handler(int signum)
{
sigusr1_received++;
}
static void test_send_signal_common(struct perf_event_attr *attr,
bool signal_thread)
{
struct test_send_signal_kern *skel;
int pipe_c2p[2], pipe_p2c[2];
int err = -1, pmu_fd = -1;
char buf[256];
pid_t pid;
if (!ASSERT_OK(pipe(pipe_c2p), "pipe_c2p"))
return;
if (!ASSERT_OK(pipe(pipe_p2c), "pipe_p2c")) {
close(pipe_c2p[0]);
close(pipe_c2p[1]);
return;
}
pid = fork();
if (!ASSERT_GE(pid, 0, "fork")) {
close(pipe_c2p[0]);
close(pipe_c2p[1]);
close(pipe_p2c[0]);
close(pipe_p2c[1]);
return;
}
if (pid == 0) {
int old_prio;
/* install signal handler and notify parent */
signal(SIGUSR1, sigusr1_handler);
close(pipe_c2p[0]); /* close read */
close(pipe_p2c[1]); /* close write */
/* boost with a high priority so we got a higher chance
* that if an interrupt happens, the underlying task
* is this process.
*/
errno = 0;
old_prio = getpriority(PRIO_PROCESS, 0);
ASSERT_OK(errno, "getpriority");
ASSERT_OK(setpriority(PRIO_PROCESS, 0, -20), "setpriority");
/* notify parent signal handler is installed */
ASSERT_EQ(write(pipe_c2p[1], buf, 1), 1, "pipe_write");
/* make sure parent enabled bpf program to send_signal */
ASSERT_EQ(read(pipe_p2c[0], buf, 1), 1, "pipe_read");
/* wait a little for signal handler */
sleep(1);
buf[0] = sigusr1_received ? '2' : '0';
ASSERT_EQ(write(pipe_c2p[1], buf, 1), 1, "pipe_write");
/* wait for parent notification and exit */
ASSERT_EQ(read(pipe_p2c[0], buf, 1), 1, "pipe_read");
/* restore the old priority */
ASSERT_OK(setpriority(PRIO_PROCESS, 0, old_prio), "setpriority");
close(pipe_c2p[1]);
close(pipe_p2c[0]);
exit(0);
}
close(pipe_c2p[1]); /* close write */
close(pipe_p2c[0]); /* close read */
skel = test_send_signal_kern__open_and_load();
if (!ASSERT_OK_PTR(skel, "skel_open_and_load"))
goto skel_open_load_failure;
if (!attr) {
err = test_send_signal_kern__attach(skel);
if (!ASSERT_OK(err, "skel_attach")) {
err = -1;
goto destroy_skel;
}
} else {
pmu_fd = syscall(__NR_perf_event_open, attr, pid, -1,
-1 /* group id */, 0 /* flags */);
if (!ASSERT_GE(pmu_fd, 0, "perf_event_open")) {
err = -1;
goto destroy_skel;
}
skel->links.send_signal_perf =
bpf_program__attach_perf_event(skel->progs.send_signal_perf, pmu_fd);
if (!ASSERT_OK_PTR(skel->links.send_signal_perf, "attach_perf_event"))
goto disable_pmu;
}
/* wait until child signal handler installed */
ASSERT_EQ(read(pipe_c2p[0], buf, 1), 1, "pipe_read");
/* trigger the bpf send_signal */
skel->bss->pid = pid;
skel->bss->sig = SIGUSR1;
skel->bss->signal_thread = signal_thread;
/* notify child that bpf program can send_signal now */
ASSERT_EQ(write(pipe_p2c[1], buf, 1), 1, "pipe_write");
/* wait for result */
err = read(pipe_c2p[0], buf, 1);
if (!ASSERT_GE(err, 0, "reading pipe"))
goto disable_pmu;
if (!ASSERT_GT(err, 0, "reading pipe error: size 0")) {
err = -1;
goto disable_pmu;
}
ASSERT_EQ(buf[0], '2', "incorrect result");
/* notify child safe to exit */
ASSERT_EQ(write(pipe_p2c[1], buf, 1), 1, "pipe_write");
disable_pmu:
close(pmu_fd);
destroy_skel:
test_send_signal_kern__destroy(skel);
skel_open_load_failure:
close(pipe_c2p[0]);
close(pipe_p2c[1]);
wait(NULL);
}
static void test_send_signal_tracepoint(bool signal_thread)
{
test_send_signal_common(NULL, signal_thread);
}
static void test_send_signal_perf(bool signal_thread)
{
struct perf_event_attr attr = {
.sample_period = 1,
.type = PERF_TYPE_SOFTWARE,
.config = PERF_COUNT_SW_CPU_CLOCK,
};
test_send_signal_common(&attr, signal_thread);
}
static void test_send_signal_nmi(bool signal_thread)
{
struct perf_event_attr attr = {
.sample_period = 1,
.type = PERF_TYPE_HARDWARE,
.config = PERF_COUNT_HW_CPU_CYCLES,
};
int pmu_fd;
/* Some setups (e.g. virtual machines) might run with hardware
* perf events disabled. If this is the case, skip this test.
*/
pmu_fd = syscall(__NR_perf_event_open, &attr, 0 /* pid */,
-1 /* cpu */, -1 /* group_fd */, 0 /* flags */);
if (pmu_fd == -1) {
if (errno == ENOENT) {
printf("%s:SKIP:no PERF_COUNT_HW_CPU_CYCLES\n",
__func__);
test__skip();
return;
}
/* Let the test fail with a more informative message */
} else {
close(pmu_fd);
}
test_send_signal_common(&attr, signal_thread);
}
void test_send_signal(void)
{
if (test__start_subtest("send_signal_tracepoint"))
test_send_signal_tracepoint(false);
if (test__start_subtest("send_signal_perf"))
test_send_signal_perf(false);
if (test__start_subtest("send_signal_nmi"))
test_send_signal_nmi(false);
if (test__start_subtest("send_signal_tracepoint_thread"))
test_send_signal_tracepoint(true);
if (test__start_subtest("send_signal_perf_thread"))
test_send_signal_perf(true);
if (test__start_subtest("send_signal_nmi_thread"))
test_send_signal_nmi(true);
}
|
