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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}
1// SPDX-License-Identifier: GPL-2.0
2#include <test_progs.h>
3#include "test_send_signal_kern.skel.h"
4
5static volatile int sigusr1_received = 0;
6
7static void sigusr1_handler(int signum)
8{
9 sigusr1_received++;
10}
11
12static void test_send_signal_common(struct perf_event_attr *attr,
13 bool signal_thread,
14 const char *test_name)
15{
16 struct test_send_signal_kern *skel;
17 int pipe_c2p[2], pipe_p2c[2];
18 int err = -1, pmu_fd = -1;
19 __u32 duration = 0;
20 char buf[256];
21 pid_t pid;
22
23 if (CHECK(pipe(pipe_c2p), test_name,
24 "pipe pipe_c2p error: %s\n", strerror(errno)))
25 return;
26
27 if (CHECK(pipe(pipe_p2c), test_name,
28 "pipe pipe_p2c error: %s\n", strerror(errno))) {
29 close(pipe_c2p[0]);
30 close(pipe_c2p[1]);
31 return;
32 }
33
34 pid = fork();
35 if (CHECK(pid < 0, test_name, "fork error: %s\n", strerror(errno))) {
36 close(pipe_c2p[0]);
37 close(pipe_c2p[1]);
38 close(pipe_p2c[0]);
39 close(pipe_p2c[1]);
40 return;
41 }
42
43 if (pid == 0) {
44 /* install signal handler and notify parent */
45 signal(SIGUSR1, sigusr1_handler);
46
47 close(pipe_c2p[0]); /* close read */
48 close(pipe_p2c[1]); /* close write */
49
50 /* notify parent signal handler is installed */
51 CHECK(write(pipe_c2p[1], buf, 1) != 1, "pipe_write", "err %d\n", -errno);
52
53 /* make sure parent enabled bpf program to send_signal */
54 CHECK(read(pipe_p2c[0], buf, 1) != 1, "pipe_read", "err %d\n", -errno);
55
56 /* wait a little for signal handler */
57 sleep(1);
58
59 buf[0] = sigusr1_received ? '2' : '0';
60 CHECK(write(pipe_c2p[1], buf, 1) != 1, "pipe_write", "err %d\n", -errno);
61
62 /* wait for parent notification and exit */
63 CHECK(read(pipe_p2c[0], buf, 1) != 1, "pipe_read", "err %d\n", -errno);
64
65 close(pipe_c2p[1]);
66 close(pipe_p2c[0]);
67 exit(0);
68 }
69
70 close(pipe_c2p[1]); /* close write */
71 close(pipe_p2c[0]); /* close read */
72
73 skel = test_send_signal_kern__open_and_load();
74 if (CHECK(!skel, "skel_open_and_load", "skeleton open_and_load failed\n"))
75 goto skel_open_load_failure;
76
77 if (!attr) {
78 err = test_send_signal_kern__attach(skel);
79 if (CHECK(err, "skel_attach", "skeleton attach failed\n")) {
80 err = -1;
81 goto destroy_skel;
82 }
83 } else {
84 pmu_fd = syscall(__NR_perf_event_open, attr, pid, -1,
85 -1 /* group id */, 0 /* flags */);
86 if (CHECK(pmu_fd < 0, test_name, "perf_event_open error: %s\n",
87 strerror(errno))) {
88 err = -1;
89 goto destroy_skel;
90 }
91
92 skel->links.send_signal_perf =
93 bpf_program__attach_perf_event(skel->progs.send_signal_perf, pmu_fd);
94 if (CHECK(IS_ERR(skel->links.send_signal_perf), "attach_perf_event",
95 "err %ld\n", PTR_ERR(skel->links.send_signal_perf)))
96 goto disable_pmu;
97 }
98
99 /* wait until child signal handler installed */
100 CHECK(read(pipe_c2p[0], buf, 1) != 1, "pipe_read", "err %d\n", -errno);
101
102 /* trigger the bpf send_signal */
103 skel->bss->pid = pid;
104 skel->bss->sig = SIGUSR1;
105 skel->bss->signal_thread = signal_thread;
106
107 /* notify child that bpf program can send_signal now */
108 CHECK(write(pipe_p2c[1], buf, 1) != 1, "pipe_write", "err %d\n", -errno);
109
110 /* wait for result */
111 err = read(pipe_c2p[0], buf, 1);
112 if (CHECK(err < 0, test_name, "reading pipe error: %s\n", strerror(errno)))
113 goto disable_pmu;
114 if (CHECK(err == 0, test_name, "reading pipe error: size 0\n")) {
115 err = -1;
116 goto disable_pmu;
117 }
118
119 CHECK(buf[0] != '2', test_name, "incorrect result\n");
120
121 /* notify child safe to exit */
122 CHECK(write(pipe_p2c[1], buf, 1) != 1, "pipe_write", "err %d\n", -errno);
123
124disable_pmu:
125 close(pmu_fd);
126destroy_skel:
127 test_send_signal_kern__destroy(skel);
128skel_open_load_failure:
129 close(pipe_c2p[0]);
130 close(pipe_p2c[1]);
131 wait(NULL);
132}
133
134static void test_send_signal_tracepoint(bool signal_thread)
135{
136 test_send_signal_common(NULL, signal_thread, "tracepoint");
137}
138
139static void test_send_signal_perf(bool signal_thread)
140{
141 struct perf_event_attr attr = {
142 .sample_period = 1,
143 .type = PERF_TYPE_SOFTWARE,
144 .config = PERF_COUNT_SW_CPU_CLOCK,
145 };
146
147 test_send_signal_common(&attr, signal_thread, "perf_sw_event");
148}
149
150static void test_send_signal_nmi(bool signal_thread)
151{
152 struct perf_event_attr attr = {
153 .sample_period = 1,
154 .type = PERF_TYPE_HARDWARE,
155 .config = PERF_COUNT_HW_CPU_CYCLES,
156 };
157 int pmu_fd;
158
159 /* Some setups (e.g. virtual machines) might run with hardware
160 * perf events disabled. If this is the case, skip this test.
161 */
162 pmu_fd = syscall(__NR_perf_event_open, &attr, 0 /* pid */,
163 -1 /* cpu */, -1 /* group_fd */, 0 /* flags */);
164 if (pmu_fd == -1) {
165 if (errno == ENOENT) {
166 printf("%s:SKIP:no PERF_COUNT_HW_CPU_CYCLES\n",
167 __func__);
168 test__skip();
169 return;
170 }
171 /* Let the test fail with a more informative message */
172 } else {
173 close(pmu_fd);
174 }
175
176 test_send_signal_common(&attr, signal_thread, "perf_hw_event");
177}
178
179void test_send_signal(void)
180{
181 if (test__start_subtest("send_signal_tracepoint"))
182 test_send_signal_tracepoint(false);
183 if (test__start_subtest("send_signal_perf"))
184 test_send_signal_perf(false);
185 if (test__start_subtest("send_signal_nmi"))
186 test_send_signal_nmi(false);
187 if (test__start_subtest("send_signal_tracepoint_thread"))
188 test_send_signal_tracepoint(true);
189 if (test__start_subtest("send_signal_perf_thread"))
190 test_send_signal_perf(true);
191 if (test__start_subtest("send_signal_nmi_thread"))
192 test_send_signal_nmi(true);
193}