tools/perf/bench/sched-seccomp-notify.c

   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 synchronous 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 }