tools/testing/selftests/proc/proc-fsconfig-hidepid.c

   1 /*
   2  * Copyright © 2020 Alexey Gladkov <gladkov.alexey@gmail.com>
   3  *
   4  * Permission to use, copy, modify, and distribute this software for any
   5  * purpose with or without fee is hereby granted, provided that the above
   6  * copyright notice and this permission notice appear in all copies.
   7  *
   8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
   9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  15  */
  16 #include <assert.h>
  17 #include <unistd.h>
  18 #include <stdlib.h>
  19 #include <errno.h>
  20 #include <linux/mount.h>
  21 #include <linux/unistd.h>
  22
  23 static inline int fsopen(const char *fsname, unsigned int flags)
  24 {
  25         return syscall(__NR_fsopen, fsname, flags);
  26 }
  27
  28 static inline int fsconfig(int fd, unsigned int cmd, const char *key, const void *val, int aux)
  29 {
  30         return syscall(__NR_fsconfig, fd, cmd, key, val, aux);
  31 }
  32
  33 int main(void)
  34 {
  35         int fsfd, ret;
  36         int hidepid = 2;
  37
  38         assert((fsfd = fsopen("proc", 0)) != -1);
  39
  40         ret = fsconfig(fsfd, FSCONFIG_SET_BINARY, "hidepid", &hidepid, 0);
  41         assert(ret == -1);
  42         assert(errno == EINVAL);
  43
  44         assert(!fsconfig(fsfd, FSCONFIG_SET_STRING, "hidepid", "2", 0));
  45         assert(!fsconfig(fsfd, FSCONFIG_SET_STRING, "hidepid", "invisible", 0));
  46
  47         assert(!close(fsfd));
  48
  49         return 0;
  50 }