sysdeps/unix/sysv/linux/alpha/fxstatat.c

   1 /* Copyright (C) 2005, 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, write to the Free
  16    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  17    02111-1307 USA.  */
  18
  19 #define __fxstatat64 __fxstatat64_disable
  20
  21 #include <errno.h>
  22 #include <fcntl.h>
  23 #include <stddef.h>
  24 #include <stdio.h>
  25 #include <sys/stat.h>
  26 #include <kernel_stat.h>
  27 #include <sysdep.h>
  28 #include <sys/syscall.h>
  29 #include <xstatconv.h>
  30
  31 #undef __fxstatat64
  32
  33
  34 /* Get information about the file NAME in BUF.  */
  35 int
  36 __fxstatat (int vers, int fd, const char *file, struct stat *st, int flag)
  37 {
  38   if (flag & ~AT_SYMLINK_NOFOLLOW)
  39     {
  40       __set_errno (EINVAL);
  41       return -1;
  42     }
  43
  44   char *buf = NULL;
  45
  46   if (fd != AT_FDCWD && file[0] != '/')
  47     {
  48       size_t filelen = strlen (file);
  49       static const char procfd[] = "/proc/self/fd/%d/%s";
  50       /* Buffer for the path name we are going to use.  It consists of
  51          - the string /proc/self/fd/
  52          - the file descriptor number
  53          - the file name provided.
  54          The final NUL is included in the sizeof.   A bit of overhead
  55          due to the format elements compensates for possible negative
  56          numbers.  */
  57       size_t buflen = sizeof (procfd) + sizeof (int) * 3 + filelen;
  58       buf = alloca (buflen);
  59
  60       __snprintf (buf, buflen, procfd, fd, file);
  61       file = buf;
  62     }
  63
  64   INTERNAL_SYSCALL_DECL (err);
  65   int result, errno_out;
  66   struct kernel_stat kst;
  67
  68   if (vers == _STAT_VER_KERNEL64 && !__libc_missing_axp_stat64)
  69     {
  70       if (flag & AT_SYMLINK_NOFOLLOW)
  71         result = INTERNAL_SYSCALL (lstat64, err, 2, file, st);
  72       else
  73         result = INTERNAL_SYSCALL (stat64, err, 2, file, st);
  74
  75       if (__builtin_expect (!INTERNAL_SYSCALL_ERROR_P (result, err), 1))
  76         return result;
  77       errno_out = INTERNAL_SYSCALL_ERRNO (result, err);
  78       if (errno_out != ENOSYS)
  79         goto fail;
  80       __libc_missing_axp_stat64 = 1;
  81     }
  82
  83   if (flag & AT_SYMLINK_NOFOLLOW)
  84     result = INTERNAL_SYSCALL (lstat, err, 2, file, &kst);
  85   else
  86     result = INTERNAL_SYSCALL (stat, err, 2, file, &kst);
  87
  88   if (__builtin_expect (!INTERNAL_SYSCALL_ERROR_P (result, err), 1))
  89     return __xstat_conv (vers, &kst, st);
  90   errno_out = INTERNAL_SYSCALL_ERRNO (result, err);
  91
  92  fail:
  93   __atfct_seterrno (errno_out, fd, buf);
  94
  95   return -1;
  96 }
  97 libc_hidden_def (__fxstatat)
  98 strong_alias (__fxstatat, __fxstatat64);
  99 libc_hidden_ver(__fxstatat, __fxstatat64);