sysdeps/unix/sysv/linux/s390/s390-32/chown.c

   1 /* Copyright (C) 2000,2001,2002,2003,2004,2006 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, see
  16    <http://www.gnu.org/licenses/>.  */
  17
  18 #include <errno.h>
  19 #include <unistd.h>
  20
  21 #include <sysdep.h>
  22 #include <sys/syscall.h>
  23 #include <shlib-compat.h>
  24 #include <bp-checks.h>
  25
  26 #include <linux/posix_types.h>
  27 #include <kernel-features.h>
  28
  29 /*
  30   In Linux 2.1.x the chown functions have been changed.  A new function lchown
  31   was introduced.  The new chown now follows symlinks - the old chown and the
  32   new lchown do not follow symlinks.
  33   The new lchown function has the same number as the old chown had and the
  34   new chown has a new number.  When compiling with headers from Linux > 2.1.8x
  35   it's impossible to run this libc with older kernels.  In these cases libc
  36   has therefore to route calls to chown to the old chown function.
  37 */
  38
  39 /* Running under Linux > 2.1.80.  */
  40
  41 #ifdef __NR_chown32
  42 # if __ASSUME_32BITUIDS == 0
  43 /* This variable is shared with all files that need to check for 32bit
  44    uids.  */
  45 extern int __libc_missing_32bit_uids;
  46 # endif
  47 #endif /* __NR_chown32 */
  48
  49 int
  50 __real_chown (const char *file, uid_t owner, gid_t group)
  51 {
  52 #if __ASSUME_32BITUIDS > 0
  53   return INLINE_SYSCALL (chown32, 3, CHECK_STRING (file), owner, group);
  54 #else
  55   static int __libc_old_chown;
  56   int result;
  57
  58   if (!__libc_old_chown)
  59     {
  60       int saved_errno = errno;
  61 # ifdef __NR_chown32
  62       if (__libc_missing_32bit_uids <= 0)
  63         {
  64           int result;
  65           int saved_errno = errno;
  66
  67           result = INLINE_SYSCALL (chown32, 3, CHECK_STRING (file), owner, group);
  68           if (result == 0 || errno != ENOSYS)
  69             return result;
  70
  71           __set_errno (saved_errno);
  72           __libc_missing_32bit_uids = 1;
  73         }
  74 # endif /* __NR_chown32 */
  75       if (((owner + 1) > (uid_t) ((__kernel_uid_t) -1U))
  76           || ((group + 1) > (gid_t) ((__kernel_gid_t) -1U)))
  77         {
  78           __set_errno (EINVAL);
  79           return -1;
  80         }
  81
  82       result = INLINE_SYSCALL (chown, 3, CHECK_STRING (file), owner, group);
  83
  84       if (result >= 0 || errno != ENOSYS)
  85         return result;
  86
  87       __set_errno (saved_errno);
  88       __libc_old_chown = 1;
  89     }
  90
  91   return __lchown (file, owner, group);
  92 #endif
  93 }
  94
  95
  96 #if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_1)
  97 /* Compiling for compatibiity.  */
  98 int
  99 attribute_compat_text_section
 100 __chown_is_lchown (const char *file, uid_t owner, gid_t group)
 101 {
 102   return __lchown (file, owner, group);
 103 }
 104 #endif
 105
 106 #if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_1)
 107 strong_alias (__chown_is_lchown, _chown_is_lchown)
 108 compat_symbol (libc, __chown_is_lchown, __chown, GLIBC_2_0);
 109 compat_symbol (libc, _chown_is_lchown, chown, GLIBC_2_0);
 110
 111 strong_alias (__real_chown, _real_chown)
 112 versioned_symbol (libc, __real_chown, __chown, GLIBC_2_1);
 113 versioned_symbol (libc, _real_chown, chown, GLIBC_2_1);
 114 libc_hidden_ver (__real_chown, __chown)
 115 #else
 116 strong_alias (__real_chown, __chown)
 117 libc_hidden_def (__chown)
 118 weak_alias (__real_chown, chown)
 119 #endif