syscalls/linkat.c

   1 /*
   2  * SYSCALL_DEFINE5(linkat, int, olddfd, const char __user *, oldname,
   3          int, newdfd, const char __user *, newname, int, flags)
   4  */
   5 #include <fcntl.h>
   6 #include <stdlib.h>
   7 #include "shm.h"
   8 #include "sanitise.h"
   9 #include "compat.h"
  10
  11 static void sanitise_linkat(int childno)
  12 {
  13         /* .. If oldpath is relative and olddirfd is the special value AT_FDCWD, then oldpath is
  14          * interpreted relative to the current working directory of the calling process  */
  15         if ((rand() % 100) == 0)
  16                 shm->syscall[childno].a1 = AT_FDCWD;
  17 }
  18
  19 struct syscallentry syscall_linkat = {
  20         .name = "linkat",
  21         .num_args = 5,
  22         .arg1name = "olddfd",
  23         .arg1type = ARG_FD,
  24         .arg2name = "oldname",
  25         .arg2type = ARG_PATHNAME,
  26         .arg3name = "newdfd",
  27         .arg3type = ARG_FD,
  28         .arg4name = "newname",
  29         .arg4type = ARG_PATHNAME,
  30         .arg5name = "flags",
  31         .arg5type = ARG_LIST,
  32         .arg5list = {
  33                 .num = 2,
  34                 .values = { AT_SYMLINK_FOLLOW , AT_EMPTY_PATH },
  35         },
  36         .flags = NEED_ALARM,
  37         .group = GROUP_VFS,
  38         .sanitise = sanitise_linkat,
  39 };