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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
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}
1// SPDX-License-Identifier: GPL-2.0
2#include <test_progs.h>
3
4static volatile int sigusr1_received = 0;
5
6static void sigusr1_handler(int signum)
7{
8 sigusr1_received++;
9}
10
11static void test_send_signal_common(struct perf_event_attr *attr,
12 int prog_type,
13 const char *test_name)
14{
15 int err = -1, pmu_fd, prog_fd, info_map_fd, status_map_fd;
16 const char *file = "./test_send_signal_kern.o";
17 struct bpf_object *obj = NULL;
18 int pipe_c2p[2], pipe_p2c[2];
19 __u32 key = 0, duration = 0;
20 char buf[256];
21 pid_t pid;
22 __u64 val;
23
24 if (CHECK(pipe(pipe_c2p), test_name,
25 "pipe pipe_c2p error: %s\n", strerror(errno)))
26 return;
27
28 if (CHECK(pipe(pipe_p2c), test_name,
29 "pipe pipe_p2c error: %s\n", strerror(errno))) {
30 close(pipe_c2p[0]);
31 close(pipe_c2p[1]);
32 return;
33 }
34
35 pid = fork();
36 if (CHECK(pid < 0, test_name, "fork error: %s\n", strerror(errno))) {
37 close(pipe_c2p[0]);
38 close(pipe_c2p[1]);
39 close(pipe_p2c[0]);
40 close(pipe_p2c[1]);
41 return;
42 }
43
44 if (pid == 0) {
45 /* install signal handler and notify parent */
46 signal(SIGUSR1, sigusr1_handler);
47
48 close(pipe_c2p[0]); /* close read */
49 close(pipe_p2c[1]); /* close write */
50
51 /* notify parent signal handler is installed */
52 write(pipe_c2p[1], buf, 1);
53
54 /* make sure parent enabled bpf program to send_signal */
55 read(pipe_p2c[0], buf, 1);
56
57 /* wait a little for signal handler */
58 sleep(1);
59
60 if (sigusr1_received)
61 write(pipe_c2p[1], "2", 1);
62 else
63 write(pipe_c2p[1], "0", 1);
64
65 /* wait for parent notification and exit */
66 read(pipe_p2c[0], buf, 1);
67
68 close(pipe_c2p[1]);
69 close(pipe_p2c[0]);
70 exit(0);
71 }
72
73 close(pipe_c2p[1]); /* close write */
74 close(pipe_p2c[0]); /* close read */
75
76 err = bpf_prog_load(file, prog_type, &obj, &prog_fd);
77 if (CHECK(err < 0, test_name, "bpf_prog_load error: %s\n",
78 strerror(errno)))
79 goto prog_load_failure;
80
81 pmu_fd = syscall(__NR_perf_event_open, attr, pid, -1,
82 -1 /* group id */, 0 /* flags */);
83 if (CHECK(pmu_fd < 0, test_name, "perf_event_open error: %s\n",
84 strerror(errno))) {
85 err = -1;
86 goto close_prog;
87 }
88
89 err = ioctl(pmu_fd, PERF_EVENT_IOC_ENABLE, 0);
90 if (CHECK(err < 0, test_name, "ioctl perf_event_ioc_enable error: %s\n",
91 strerror(errno)))
92 goto disable_pmu;
93
94 err = ioctl(pmu_fd, PERF_EVENT_IOC_SET_BPF, prog_fd);
95 if (CHECK(err < 0, test_name, "ioctl perf_event_ioc_set_bpf error: %s\n",
96 strerror(errno)))
97 goto disable_pmu;
98
99 err = -1;
100 info_map_fd = bpf_object__find_map_fd_by_name(obj, "info_map");
101 if (CHECK(info_map_fd < 0, test_name, "find map %s error\n", "info_map"))
102 goto disable_pmu;
103
104 status_map_fd = bpf_object__find_map_fd_by_name(obj, "status_map");
105 if (CHECK(status_map_fd < 0, test_name, "find map %s error\n", "status_map"))
106 goto disable_pmu;
107
108 /* wait until child signal handler installed */
109 read(pipe_c2p[0], buf, 1);
110
111 /* trigger the bpf send_signal */
112 key = 0;
113 val = (((__u64)(SIGUSR1)) << 32) | pid;
114 bpf_map_update_elem(info_map_fd, &key, &val, 0);
115
116 /* notify child that bpf program can send_signal now */
117 write(pipe_p2c[1], buf, 1);
118
119 /* wait for result */
120 err = read(pipe_c2p[0], buf, 1);
121 if (CHECK(err < 0, test_name, "reading pipe error: %s\n", strerror(errno)))
122 goto disable_pmu;
123 if (CHECK(err == 0, test_name, "reading pipe error: size 0\n")) {
124 err = -1;
125 goto disable_pmu;
126 }
127
128 CHECK(buf[0] != '2', test_name, "incorrect result\n");
129
130 /* notify child safe to exit */
131 write(pipe_p2c[1], buf, 1);
132
133disable_pmu:
134 close(pmu_fd);
135close_prog:
136 bpf_object__close(obj);
137prog_load_failure:
138 close(pipe_c2p[0]);
139 close(pipe_p2c[1]);
140 wait(NULL);
141}
142
143static void test_send_signal_tracepoint(void)
144{
145 const char *id_path = "/sys/kernel/debug/tracing/events/syscalls/sys_enter_nanosleep/id";
146 struct perf_event_attr attr = {
147 .type = PERF_TYPE_TRACEPOINT,
148 .sample_type = PERF_SAMPLE_RAW | PERF_SAMPLE_CALLCHAIN,
149 .sample_period = 1,
150 .wakeup_events = 1,
151 };
152 __u32 duration = 0;
153 int bytes, efd;
154 char buf[256];
155
156 efd = open(id_path, O_RDONLY, 0);
157 if (CHECK(efd < 0, "tracepoint",
158 "open syscalls/sys_enter_nanosleep/id failure: %s\n",
159 strerror(errno)))
160 return;
161
162 bytes = read(efd, buf, sizeof(buf));
163 close(efd);
164 if (CHECK(bytes <= 0 || bytes >= sizeof(buf), "tracepoint",
165 "read syscalls/sys_enter_nanosleep/id failure: %s\n",
166 strerror(errno)))
167 return;
168
169 attr.config = strtol(buf, NULL, 0);
170
171 test_send_signal_common(&attr, BPF_PROG_TYPE_TRACEPOINT, "tracepoint");
172}
173
174static void test_send_signal_perf(void)
175{
176 struct perf_event_attr attr = {
177 .sample_period = 1,
178 .type = PERF_TYPE_SOFTWARE,
179 .config = PERF_COUNT_SW_CPU_CLOCK,
180 };
181
182 test_send_signal_common(&attr, BPF_PROG_TYPE_PERF_EVENT,
183 "perf_sw_event");
184}
185
186static void test_send_signal_nmi(void)
187{
188 struct perf_event_attr attr = {
189 .sample_freq = 50,
190 .freq = 1,
191 .type = PERF_TYPE_HARDWARE,
192 .config = PERF_COUNT_HW_CPU_CYCLES,
193 };
194 int pmu_fd;
195
196 /* Some setups (e.g. virtual machines) might run with hardware
197 * perf events disabled. If this is the case, skip this test.
198 */
199 pmu_fd = syscall(__NR_perf_event_open, &attr, 0 /* pid */,
200 -1 /* cpu */, -1 /* group_fd */, 0 /* flags */);
201 if (pmu_fd == -1) {
202 if (errno == ENOENT) {
203 printf("%s:SKIP:no PERF_COUNT_HW_CPU_CYCLES\n",
204 __func__);
205 test__skip();
206 return;
207 }
208 /* Let the test fail with a more informative message */
209 } else {
210 close(pmu_fd);
211 }
212
213 test_send_signal_common(&attr, BPF_PROG_TYPE_PERF_EVENT,
214 "perf_hw_event");
215}
216
217void test_send_signal(void)
218{
219 if (test__start_subtest("send_signal_tracepoint"))
220 test_send_signal_tracepoint();
221 if (test__start_subtest("send_signal_perf"))
222 test_send_signal_perf();
223 if (test__start_subtest("send_signal_nmi"))
224 test_send_signal_nmi();
225}