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1// SPDX-License-Identifier: GPL-2.0
2#include <test_progs.h>
3#include <sys/time.h>
4#include <sys/resource.h>
5#include "test_send_signal_kern.skel.h"
6#include "io_helpers.h"
7
8static int sigusr1_received;
9
10static void sigusr1_handler(int signum)
11{
12 sigusr1_received = 8;
13}
14
15static void sigusr1_siginfo_handler(int s, siginfo_t *i, void *v)
16{
17 sigusr1_received = (int)(long long)i->si_value.sival_ptr;
18}
19
20static void test_send_signal_common(struct perf_event_attr *attr,
21 bool signal_thread, bool remote)
22{
23 struct test_send_signal_kern *skel;
24 struct sigaction sa;
25 int pipe_c2p[2], pipe_p2c[2];
26 int err = -1, pmu_fd = -1;
27 volatile int j = 0;
28 int retry_count;
29 char buf[256];
30 pid_t pid;
31 int old_prio;
32
33 if (!ASSERT_OK(pipe(pipe_c2p), "pipe_c2p"))
34 return;
35
36 if (!ASSERT_OK(pipe(pipe_p2c), "pipe_p2c")) {
37 close(pipe_c2p[0]);
38 close(pipe_c2p[1]);
39 return;
40 }
41
42 pid = fork();
43 if (!ASSERT_GE(pid, 0, "fork")) {
44 close(pipe_c2p[0]);
45 close(pipe_c2p[1]);
46 close(pipe_p2c[0]);
47 close(pipe_p2c[1]);
48 return;
49 }
50
51 if (pid == 0) {
52 /* install signal handler and notify parent */
53 if (remote) {
54 sa.sa_sigaction = sigusr1_siginfo_handler;
55 sa.sa_flags = SA_RESTART | SA_SIGINFO;
56 ASSERT_NEQ(sigaction(SIGUSR1, &sa, NULL), -1, "sigaction");
57 } else {
58 ASSERT_NEQ(signal(SIGUSR1, sigusr1_handler), SIG_ERR, "signal");
59 }
60
61 close(pipe_c2p[0]); /* close read */
62 close(pipe_p2c[1]); /* close write */
63
64 /* boost with a high priority so we got a higher chance
65 * that if an interrupt happens, the underlying task
66 * is this process.
67 */
68 if (!remote) {
69 errno = 0;
70 old_prio = getpriority(PRIO_PROCESS, 0);
71 ASSERT_OK(errno, "getpriority");
72 ASSERT_OK(setpriority(PRIO_PROCESS, 0, -20), "setpriority");
73 }
74
75 /* notify parent signal handler is installed */
76 ASSERT_EQ(write(pipe_c2p[1], buf, 1), 1, "pipe_write");
77
78 /* make sure parent enabled bpf program to send_signal */
79 ASSERT_EQ(read(pipe_p2c[0], buf, 1), 1, "pipe_read");
80
81 /* wait a little for signal handler */
82 for (int i = 0; i < 1000000000 && !sigusr1_received; i++) {
83 j /= i + j + 1;
84 if (remote)
85 sleep(1);
86 else
87 if (!attr)
88 /* trigger the nanosleep tracepoint program. */
89 usleep(1);
90 }
91
92 buf[0] = sigusr1_received;
93
94 ASSERT_EQ(sigusr1_received, 8, "sigusr1_received");
95 ASSERT_EQ(write(pipe_c2p[1], buf, 1), 1, "pipe_write");
96
97 /* wait for parent notification and exit */
98 ASSERT_EQ(read(pipe_p2c[0], buf, 1), 1, "pipe_read");
99
100 /* restore the old priority */
101 if (!remote)
102 ASSERT_OK(setpriority(PRIO_PROCESS, 0, old_prio), "setpriority");
103
104 close(pipe_c2p[1]);
105 close(pipe_p2c[0]);
106 exit(0);
107 }
108
109 close(pipe_c2p[1]); /* close write */
110 close(pipe_p2c[0]); /* close read */
111
112 skel = test_send_signal_kern__open_and_load();
113 if (!ASSERT_OK_PTR(skel, "skel_open_and_load"))
114 goto skel_open_load_failure;
115
116 /* boost with a high priority so we got a higher chance
117 * that if an interrupt happens, the underlying task
118 * is this process.
119 */
120 if (remote) {
121 errno = 0;
122 old_prio = getpriority(PRIO_PROCESS, 0);
123 ASSERT_OK(errno, "getpriority");
124 ASSERT_OK(setpriority(PRIO_PROCESS, 0, -20), "setpriority");
125 }
126
127 if (!attr) {
128 err = test_send_signal_kern__attach(skel);
129 if (!ASSERT_OK(err, "skel_attach")) {
130 err = -1;
131 goto destroy_skel;
132 }
133 } else {
134 if (!remote)
135 pmu_fd = syscall(__NR_perf_event_open, attr, pid, -1 /* cpu */,
136 -1 /* group id */, 0 /* flags */);
137 else
138 pmu_fd = syscall(__NR_perf_event_open, attr, getpid(), -1 /* cpu */,
139 -1 /* group id */, 0 /* flags */);
140 if (!ASSERT_GE(pmu_fd, 0, "perf_event_open")) {
141 err = -1;
142 goto destroy_skel;
143 }
144
145 skel->links.send_signal_perf =
146 bpf_program__attach_perf_event(skel->progs.send_signal_perf, pmu_fd);
147 if (!ASSERT_OK_PTR(skel->links.send_signal_perf, "attach_perf_event"))
148 goto disable_pmu;
149 }
150
151 /* wait until child signal handler installed */
152 ASSERT_EQ(read(pipe_c2p[0], buf, 1), 1, "pipe_read");
153
154 /* trigger the bpf send_signal */
155 skel->bss->signal_thread = signal_thread;
156 skel->bss->sig = SIGUSR1;
157 if (!remote) {
158 skel->bss->target_pid = 0;
159 skel->bss->pid = pid;
160 } else {
161 skel->bss->target_pid = pid;
162 skel->bss->pid = getpid();
163 }
164
165 /* notify child that bpf program can send_signal now */
166 ASSERT_EQ(write(pipe_p2c[1], buf, 1), 1, "pipe_write");
167
168 for (retry_count = 0;;) {
169 /* For the remote test, the BPF program is triggered from this
170 * process but the other process/thread is signaled.
171 */
172 if (remote) {
173 if (!attr) {
174 for (int i = 0; i < 10; i++)
175 usleep(1);
176 } else {
177 for (int i = 0; i < 100000000; i++)
178 j /= i + 1;
179 }
180 }
181 /* wait for result */
182 err = read_with_timeout(pipe_c2p[0], buf, 1, 100);
183 if (err == -EAGAIN && retry_count++ < 10000)
184 continue;
185 break;
186 }
187 if (!ASSERT_GE(err, 0, "reading pipe"))
188 goto disable_pmu;
189 if (!ASSERT_GT(err, 0, "reading pipe error: size 0")) {
190 err = -1;
191 goto disable_pmu;
192 }
193
194 ASSERT_EQ(buf[0], 8, "incorrect result");
195
196 /* notify child safe to exit */
197 ASSERT_EQ(write(pipe_p2c[1], buf, 1), 1, "pipe_write");
198
199disable_pmu:
200 close(pmu_fd);
201destroy_skel:
202 test_send_signal_kern__destroy(skel);
203 /* restore the old priority */
204 if (remote)
205 ASSERT_OK(setpriority(PRIO_PROCESS, 0, old_prio), "setpriority");
206skel_open_load_failure:
207 close(pipe_c2p[0]);
208 close(pipe_p2c[1]);
209 wait(NULL);
210}
211
212static void test_send_signal_tracepoint(bool signal_thread, bool remote)
213{
214 test_send_signal_common(NULL, signal_thread, remote);
215}
216
217static void test_send_signal_perf(bool signal_thread, bool remote)
218{
219 struct perf_event_attr attr = {
220 .freq = 1,
221 .sample_freq = 1000,
222 .type = PERF_TYPE_SOFTWARE,
223 .config = PERF_COUNT_SW_CPU_CLOCK,
224 };
225
226 test_send_signal_common(&attr, signal_thread, remote);
227}
228
229static void test_send_signal_nmi(bool signal_thread, bool remote)
230{
231 struct perf_event_attr attr = {
232 .freq = 1,
233 .sample_freq = 1000,
234 .type = PERF_TYPE_HARDWARE,
235 .config = PERF_COUNT_HW_CPU_CYCLES,
236 };
237 int pmu_fd;
238
239 /* Some setups (e.g. virtual machines) might run with hardware
240 * perf events disabled. If this is the case, skip this test.
241 */
242 pmu_fd = syscall(__NR_perf_event_open, &attr, 0 /* pid */,
243 -1 /* cpu */, -1 /* group_fd */, 0 /* flags */);
244 if (pmu_fd == -1) {
245 if (errno == ENOENT || errno == EOPNOTSUPP) {
246 printf("%s:SKIP:no PERF_COUNT_HW_CPU_CYCLES\n",
247 __func__);
248 test__skip();
249 return;
250 }
251 /* Let the test fail with a more informative message */
252 } else {
253 close(pmu_fd);
254 }
255
256 test_send_signal_common(&attr, signal_thread, remote);
257}
258
259void test_send_signal(void)
260{
261 if (test__start_subtest("send_signal_tracepoint"))
262 test_send_signal_tracepoint(false, false);
263 if (test__start_subtest("send_signal_perf"))
264 test_send_signal_perf(false, false);
265 if (test__start_subtest("send_signal_nmi"))
266 test_send_signal_nmi(false, false);
267 if (test__start_subtest("send_signal_tracepoint_thread"))
268 test_send_signal_tracepoint(true, false);
269 if (test__start_subtest("send_signal_perf_thread"))
270 test_send_signal_perf(true, false);
271 if (test__start_subtest("send_signal_nmi_thread"))
272 test_send_signal_nmi(true, false);
273
274 /* Signal remote thread and thread group */
275 if (test__start_subtest("send_signal_tracepoint_remote"))
276 test_send_signal_tracepoint(false, true);
277 if (test__start_subtest("send_signal_perf_remote"))
278 test_send_signal_perf(false, true);
279 if (test__start_subtest("send_signal_nmi_remote"))
280 test_send_signal_nmi(false, true);
281 if (test__start_subtest("send_signal_tracepoint_thread_remote"))
282 test_send_signal_tracepoint(true, true);
283 if (test__start_subtest("send_signal_perf_thread_remote"))
284 test_send_signal_perf(true, true);
285 if (test__start_subtest("send_signal_nmi_thread_remote"))
286 test_send_signal_nmi(true, true);
287}
1// SPDX-License-Identifier: GPL-2.0
2#include <test_progs.h>
3#include <sys/time.h>
4#include <sys/resource.h>
5#include "test_send_signal_kern.skel.h"
6
7static int sigusr1_received;
8
9static void sigusr1_handler(int signum)
10{
11 sigusr1_received = 1;
12}
13
14static void test_send_signal_common(struct perf_event_attr *attr,
15 bool signal_thread)
16{
17 struct test_send_signal_kern *skel;
18 int pipe_c2p[2], pipe_p2c[2];
19 int err = -1, pmu_fd = -1;
20 char buf[256];
21 pid_t pid;
22
23 if (!ASSERT_OK(pipe(pipe_c2p), "pipe_c2p"))
24 return;
25
26 if (!ASSERT_OK(pipe(pipe_p2c), "pipe_p2c")) {
27 close(pipe_c2p[0]);
28 close(pipe_c2p[1]);
29 return;
30 }
31
32 pid = fork();
33 if (!ASSERT_GE(pid, 0, "fork")) {
34 close(pipe_c2p[0]);
35 close(pipe_c2p[1]);
36 close(pipe_p2c[0]);
37 close(pipe_p2c[1]);
38 return;
39 }
40
41 if (pid == 0) {
42 int old_prio;
43 volatile int j = 0;
44
45 /* install signal handler and notify parent */
46 ASSERT_NEQ(signal(SIGUSR1, sigusr1_handler), SIG_ERR, "signal");
47
48 close(pipe_c2p[0]); /* close read */
49 close(pipe_p2c[1]); /* close write */
50
51 /* boost with a high priority so we got a higher chance
52 * that if an interrupt happens, the underlying task
53 * is this process.
54 */
55 errno = 0;
56 old_prio = getpriority(PRIO_PROCESS, 0);
57 ASSERT_OK(errno, "getpriority");
58 ASSERT_OK(setpriority(PRIO_PROCESS, 0, -20), "setpriority");
59
60 /* notify parent signal handler is installed */
61 ASSERT_EQ(write(pipe_c2p[1], buf, 1), 1, "pipe_write");
62
63 /* make sure parent enabled bpf program to send_signal */
64 ASSERT_EQ(read(pipe_p2c[0], buf, 1), 1, "pipe_read");
65
66 /* wait a little for signal handler */
67 for (int i = 0; i < 1000000000 && !sigusr1_received; i++)
68 j /= i + j + 1;
69
70 buf[0] = sigusr1_received ? '2' : '0';
71 ASSERT_EQ(sigusr1_received, 1, "sigusr1_received");
72 ASSERT_EQ(write(pipe_c2p[1], buf, 1), 1, "pipe_write");
73
74 /* wait for parent notification and exit */
75 ASSERT_EQ(read(pipe_p2c[0], buf, 1), 1, "pipe_read");
76
77 /* restore the old priority */
78 ASSERT_OK(setpriority(PRIO_PROCESS, 0, old_prio), "setpriority");
79
80 close(pipe_c2p[1]);
81 close(pipe_p2c[0]);
82 exit(0);
83 }
84
85 close(pipe_c2p[1]); /* close write */
86 close(pipe_p2c[0]); /* close read */
87
88 skel = test_send_signal_kern__open_and_load();
89 if (!ASSERT_OK_PTR(skel, "skel_open_and_load"))
90 goto skel_open_load_failure;
91
92 if (!attr) {
93 err = test_send_signal_kern__attach(skel);
94 if (!ASSERT_OK(err, "skel_attach")) {
95 err = -1;
96 goto destroy_skel;
97 }
98 } else {
99 pmu_fd = syscall(__NR_perf_event_open, attr, pid, -1 /* cpu */,
100 -1 /* group id */, 0 /* flags */);
101 if (!ASSERT_GE(pmu_fd, 0, "perf_event_open")) {
102 err = -1;
103 goto destroy_skel;
104 }
105
106 skel->links.send_signal_perf =
107 bpf_program__attach_perf_event(skel->progs.send_signal_perf, pmu_fd);
108 if (!ASSERT_OK_PTR(skel->links.send_signal_perf, "attach_perf_event"))
109 goto disable_pmu;
110 }
111
112 /* wait until child signal handler installed */
113 ASSERT_EQ(read(pipe_c2p[0], buf, 1), 1, "pipe_read");
114
115 /* trigger the bpf send_signal */
116 skel->bss->signal_thread = signal_thread;
117 skel->bss->sig = SIGUSR1;
118 skel->bss->pid = pid;
119
120 /* notify child that bpf program can send_signal now */
121 ASSERT_EQ(write(pipe_p2c[1], buf, 1), 1, "pipe_write");
122
123 /* wait for result */
124 err = read(pipe_c2p[0], buf, 1);
125 if (!ASSERT_GE(err, 0, "reading pipe"))
126 goto disable_pmu;
127 if (!ASSERT_GT(err, 0, "reading pipe error: size 0")) {
128 err = -1;
129 goto disable_pmu;
130 }
131
132 ASSERT_EQ(buf[0], '2', "incorrect result");
133
134 /* notify child safe to exit */
135 ASSERT_EQ(write(pipe_p2c[1], buf, 1), 1, "pipe_write");
136
137disable_pmu:
138 close(pmu_fd);
139destroy_skel:
140 test_send_signal_kern__destroy(skel);
141skel_open_load_failure:
142 close(pipe_c2p[0]);
143 close(pipe_p2c[1]);
144 wait(NULL);
145}
146
147static void test_send_signal_tracepoint(bool signal_thread)
148{
149 test_send_signal_common(NULL, signal_thread);
150}
151
152static void test_send_signal_perf(bool signal_thread)
153{
154 struct perf_event_attr attr = {
155 .sample_period = 1,
156 .type = PERF_TYPE_SOFTWARE,
157 .config = PERF_COUNT_SW_CPU_CLOCK,
158 };
159
160 test_send_signal_common(&attr, signal_thread);
161}
162
163static void test_send_signal_nmi(bool signal_thread)
164{
165 struct perf_event_attr attr = {
166 .sample_period = 1,
167 .type = PERF_TYPE_HARDWARE,
168 .config = PERF_COUNT_HW_CPU_CYCLES,
169 };
170 int pmu_fd;
171
172 /* Some setups (e.g. virtual machines) might run with hardware
173 * perf events disabled. If this is the case, skip this test.
174 */
175 pmu_fd = syscall(__NR_perf_event_open, &attr, 0 /* pid */,
176 -1 /* cpu */, -1 /* group_fd */, 0 /* flags */);
177 if (pmu_fd == -1) {
178 if (errno == ENOENT) {
179 printf("%s:SKIP:no PERF_COUNT_HW_CPU_CYCLES\n",
180 __func__);
181 test__skip();
182 return;
183 }
184 /* Let the test fail with a more informative message */
185 } else {
186 close(pmu_fd);
187 }
188
189 test_send_signal_common(&attr, signal_thread);
190}
191
192void test_send_signal(void)
193{
194 if (test__start_subtest("send_signal_tracepoint"))
195 test_send_signal_tracepoint(false);
196 if (test__start_subtest("send_signal_perf"))
197 test_send_signal_perf(false);
198 if (test__start_subtest("send_signal_nmi"))
199 test_send_signal_nmi(false);
200 if (test__start_subtest("send_signal_tracepoint_thread"))
201 test_send_signal_tracepoint(true);
202 if (test__start_subtest("send_signal_perf_thread"))
203 test_send_signal_perf(true);
204 if (test__start_subtest("send_signal_nmi_thread"))
205 test_send_signal_nmi(true);
206}