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 } 51