1 // SPDX-License-Identifier: GPL-2.0
2 #include <subcmd/parse-options.h>
3 #include "bench.h"
4 
5 #include <uapi/linux/filter.h>
6 #include <sys/types.h>
7 #include <sys/time.h>
8 #include <linux/unistd.h>
9 #include <sys/syscall.h>
10 #include <sys/ioctl.h>
11 #include <linux/time64.h>
12 #include <uapi/linux/seccomp.h>
13 #include <sys/prctl.h>
14 
15 #include <unistd.h>
16 #include <limits.h>
17 #include <stddef.h>
18 #include <stdint.h>
19 #include <stdio.h>
20 #include <stdlib.h>
21 #include <signal.h>
22 #include <sys/wait.h>
23 #include <string.h>
24 #include <errno.h>
25 #include <err.h>
26 #include <inttypes.h>
27 
28 #define LOOPS_DEFAULT 1000000UL
29 static uint64_t loops = LOOPS_DEFAULT;
30 static bool sync_mode;
31 
32 static const struct option options[] = {
33 	OPT_U64('l', "loop",	&loops,		"Specify number of loops"),
34 	OPT_BOOLEAN('s', "sync-mode", &sync_mode,
35 		    "Enable the synchronious mode for seccomp notifications"),
36 	OPT_END()
37 };
38 
39 static const char * const bench_seccomp_usage[] = {
40 	"perf bench sched secccomp-notify <options>",
41 	NULL
42 };
43 
44 static int seccomp(unsigned int op, unsigned int flags, void *args)
45 {
46 	return syscall(__NR_seccomp, op, flags, args);
47 }
48 
49 static int user_notif_syscall(int nr, unsigned int flags)
50 {
51 	struct sock_filter filter[] = {
52 		BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
53 			offsetof(struct seccomp_data, nr)),
54 		BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, nr, 0, 1),
55 		BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_USER_NOTIF),
56 		BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
57 	};
58 
59 	struct sock_fprog prog = {
60 		.len = (unsigned short)ARRAY_SIZE(filter),
61 		.filter = filter,
62 	};
63 
64 	return seccomp(SECCOMP_SET_MODE_FILTER, flags, &prog);
65 }
66 
67 #define USER_NOTIF_MAGIC INT_MAX
68 static void user_notification_sync_loop(int listener)
69 {
70 	struct seccomp_notif_resp resp;
71 	struct seccomp_notif req;
72 	uint64_t nr;
73 
74 	for (nr = 0; nr < loops; nr++) {
75 		memset(&req, 0, sizeof(req));
76 		if (ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req))
77 			err(EXIT_FAILURE, "SECCOMP_IOCTL_NOTIF_RECV failed");
78 
79 		if (req.data.nr != __NR_gettid)
80 			errx(EXIT_FAILURE, "unexpected syscall: %d", req.data.nr);
81 
82 		resp.id = req.id;
83 		resp.error = 0;
84 		resp.val = USER_NOTIF_MAGIC;
85 		resp.flags = 0;
86 		if (ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp))
87 			err(EXIT_FAILURE, "SECCOMP_IOCTL_NOTIF_SEND failed");
88 	}
89 }
90 
91 #ifndef SECCOMP_USER_NOTIF_FD_SYNC_WAKE_UP
92 #define SECCOMP_USER_NOTIF_FD_SYNC_WAKE_UP (1UL << 0)
93 #define SECCOMP_IOCTL_NOTIF_SET_FLAGS  SECCOMP_IOW(4, __u64)
94 #endif
95 int bench_sched_seccomp_notify(int argc, const char **argv)
96 {
97 	struct timeval start, stop, diff;
98 	unsigned long long result_usec = 0;
99 	int status, listener;
100 	pid_t pid;
101 	long ret;
102 
103 	argc = parse_options(argc, argv, options, bench_seccomp_usage, 0);
104 
105 	gettimeofday(&start, NULL);
106 
107 	prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
108 	listener = user_notif_syscall(__NR_gettid,
109 				      SECCOMP_FILTER_FLAG_NEW_LISTENER);
110 	if (listener < 0)
111 		err(EXIT_FAILURE, "can't create a notification descriptor");
112 
113 	pid = fork();
114 	if (pid < 0)
115 		err(EXIT_FAILURE, "fork");
116 	if (pid == 0) {
117 		if (prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0))
118 			err(EXIT_FAILURE, "can't set the parent death signal");
119 		while (1) {
120 			ret = syscall(__NR_gettid);
121 			if (ret == USER_NOTIF_MAGIC)
122 				continue;
123 			break;
124 		}
125 		_exit(1);
126 	}
127 
128 	if (sync_mode) {
129 		if (ioctl(listener, SECCOMP_IOCTL_NOTIF_SET_FLAGS,
130 			     SECCOMP_USER_NOTIF_FD_SYNC_WAKE_UP, 0))
131 			err(EXIT_FAILURE,
132 			    "can't set SECCOMP_USER_NOTIF_FD_SYNC_WAKE_UP");
133 	}
134 	user_notification_sync_loop(listener);
135 
136 	kill(pid, SIGKILL);
137 	if (waitpid(pid, &status, 0) != pid)
138 		err(EXIT_FAILURE, "waitpid(%d) failed", pid);
139 	if (!WIFSIGNALED(status) || WTERMSIG(status) != SIGKILL)
140 		errx(EXIT_FAILURE, "unexpected exit code: %d", status);
141 
142 	gettimeofday(&stop, NULL);
143 	timersub(&stop, &start, &diff);
144 
145 	switch (bench_format) {
146 	case BENCH_FORMAT_DEFAULT:
147 		printf("# Executed %" PRIu64 " system calls\n\n",
148 			loops);
149 
150 		result_usec = diff.tv_sec * USEC_PER_SEC;
151 		result_usec += diff.tv_usec;
152 
153 		printf(" %14s: %lu.%03lu [sec]\n\n", "Total time",
154 		       (unsigned long) diff.tv_sec,
155 		       (unsigned long) (diff.tv_usec / USEC_PER_MSEC));
156 
157 		printf(" %14lf usecs/op\n",
158 		       (double)result_usec / (double)loops);
159 		printf(" %14d ops/sec\n",
160 		       (int)((double)loops /
161 			     ((double)result_usec / (double)USEC_PER_SEC)));
162 		break;
163 
164 	case BENCH_FORMAT_SIMPLE:
165 		printf("%lu.%03lu\n",
166 		       (unsigned long) diff.tv_sec,
167 		       (unsigned long) (diff.tv_usec / USEC_PER_MSEC));
168 		break;
169 
170 	default:
171 		/* reaching here is something disaster */
172 		fprintf(stderr, "Unknown format:%d\n", bench_format);
173 		exit(1);
174 		break;
175 	}
176 
177 	return 0;
178 }
179