sysdeps/unix/sysv/linux/i386/setgid.c

   1 /* Copyright (C) 1998, 2000 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, write to the Free
  16    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  17    02111-1307 USA.  */
  18
  19 #include <errno.h>
  20 #include <unistd.h>
  21 #include <sys/types.h>
  22
  23 #include <sysdep.h>
  24 #include <sys/syscall.h>
  25
  26 #include <linux/posix_types.h>
  27
  28 #include "kernel-features.h"
  29
  30 extern int __syscall_setgid (__kernel_gid_t);
  31
  32 #ifdef __NR_setgid32
  33 extern int __syscall_setgid32 (__kernel_gid32_t);
  34 # if __ASSUME_32BITUIDS == 0
  35 /* This variable is shared with all files that need to check for 32bit
  36    uids.  */
  37 extern int __libc_missing_32bit_uids;
  38 # endif
  39 #endif /* __NR_setgid32 */
  40
  41 int
  42 __setgid (gid_t gid)
  43 {
  44 #if __ASSUME_32BITUIDS > 0
  45   return INLINE_SYSCALL (setgid32, 1, gid);
  46 #else
  47 # ifdef __NR_setgid32
  48   if (__libc_missing_32bit_uids <= 0)
  49     {
  50       int result;
  51       int saved_errno = errno;
  52
  53       result = INLINE_SYSCALL (setgid32, 1, gid);
  54
  55       if (result == 0 || errno != ENOSYS)
  56         return result;
  57
  58       __set_errno (saved_errno);
  59       __libc_missing_32bit_uids = 1;
  60     }
  61 # endif /* __NR_setgid32 */
  62
  63   if (gid == (gid_t) ~0
  64       || gid != (gid_t) ((__kernel_gid_t) gid))
  65     {
  66       __set_errno (EINVAL);
  67       return -1;
  68     }
  69
  70   return INLINE_SYSCALL (setgid, 1, gid);
  71 #endif
  72 }
  73 weak_alias (__setgid, setgid)