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glibc  2.9
setgid.c
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00001 /* Copyright (C) 1998, 2000, 2003, 2004, 2006 Free Software Foundation, Inc.
00002    This file is part of the GNU C Library.
00003 
00004    The GNU C Library is free software; you can redistribute it and/or
00005    modify it under the terms of the GNU Lesser General Public
00006    License as published by the Free Software Foundation; either
00007    version 2.1 of the License, or (at your option) any later version.
00008 
00009    The GNU C Library is distributed in the hope that it will be useful,
00010    but WITHOUT ANY WARRANTY; without even the implied warranty of
00011    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00012    Lesser General Public License for more details.
00013 
00014    You should have received a copy of the GNU Lesser General Public
00015    License along with the GNU C Library; if not, write to the Free
00016    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
00017    02111-1307 USA.  */
00018 
00019 #include <errno.h>
00020 #include <unistd.h>
00021 #include <setxid.h>
00022 #include <linux/posix_types.h>
00023 #include <kernel-features.h>
00024 
00025 
00026 #ifdef __NR_setgid32
00027 # if __ASSUME_32BITUIDS == 0
00028 /* This variable is shared with all files that need to check for 32bit
00029    uids.  */
00030 extern int __libc_missing_32bit_uids;
00031 # endif
00032 #endif /* __NR_setgid32 */
00033 
00034 int
00035 __setgid (gid_t gid)
00036 {
00037   int result;
00038 
00039 #if __ASSUME_32BITUIDS > 0
00040   result = INLINE_SETXID_SYSCALL (setgid32, 1, gid);
00041 #else
00042 # ifdef __NR_setgid32
00043   if (__libc_missing_32bit_uids <= 0)
00044     {
00045       int saved_errno = errno;
00046 
00047       result = INLINE_SETXID_SYSCALL (setgid32, 1, gid);
00048 
00049       if (result == 0)
00050        goto out;
00051       if (errno != ENOSYS)
00052        return result;
00053 
00054       __set_errno (saved_errno);
00055       __libc_missing_32bit_uids = 1;
00056     }
00057 # endif /* __NR_setgid32 */
00058 
00059   if (gid == (gid_t) ~0
00060       || gid != (gid_t) ((__kernel_gid_t) gid))
00061     {
00062       __set_errno (EINVAL);
00063       return -1;
00064     }
00065 
00066   result = INLINE_SETXID_SYSCALL (setgid, 1, gid);
00067 # ifdef __NR_setgid32
00068  out:
00069 # endif
00070 #endif
00071 
00072   return result;
00073 }
00074 #ifndef __setgid
00075 weak_alias (__setgid, setgid)
00076 #endif