glibc/sysdeps/unix/sysv/linux/i386/fxstatat.c
Ulrich Drepper 801720e63b Fix compat handling in *at functions.
When passed an empty string for the filename, the compat code
using /proc in all *at functions did the wrong thing.
2009-10-29 21:33:26 -07:00

183 lines
5.2 KiB
C

/* Copyright (C) 2005, 2006, 2009 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
/* Ho hum, if fxstatat == fxstatat64 we must get rid of the prototype or gcc
will complain since they don't strictly match. */
#define __fxstatat64 __fxstatat64_disable
#include <errno.h>
#include <fcntl.h>
#include <stddef.h>
#include <stdio.h>
#include <string.h>
#include <sys/stat.h>
#include <kernel_stat.h>
#include <sysdep.h>
#include <sys/syscall.h>
#include <bp-checks.h>
#include <kernel-features.h>
#include <xstatconv.h>
#ifdef __NR_stat64
# if __ASSUME_STAT64_SYSCALL == 0
/* The variable is shared between all wrappers around *stat64 calls. */
extern int __have_no_stat64;
# endif
#endif
/* Get information about the file NAME relative to FD in ST. */
int
__fxstatat (int vers, int fd, const char *file, struct stat *st, int flag)
{
int result;
INTERNAL_SYSCALL_DECL (err);
struct stat64 st64;
#ifdef __NR_fstatat64
# ifndef __ASSUME_ATFCTS
if (__have_atfcts >= 0)
# endif
{
result = INTERNAL_SYSCALL (fstatat64, err, 4, fd, file, &st64, flag);
# ifndef __ASSUME_ATFCTS
if (__builtin_expect (INTERNAL_SYSCALL_ERROR_P (result, err), 1)
&& INTERNAL_SYSCALL_ERRNO (result, err) == ENOSYS)
__have_atfcts = -1;
else
# endif
if (!__builtin_expect (INTERNAL_SYSCALL_ERROR_P (result, err), 1))
return __xstat32_conv (vers, &st64, st);
else
{
__set_errno (INTERNAL_SYSCALL_ERRNO (result, err));
return -1;
}
}
#endif
#ifndef __ASSUME_ATFCTS
if (__builtin_expect (flag & ~AT_SYMLINK_NOFOLLOW, 0))
{
__set_errno (EINVAL);
return -1;
}
char *buf = NULL;
if (fd != AT_FDCWD && file[0] != '/')
{
size_t filelen = strlen (file);
if (__builtin_expect (filelen == 0, 0))
{
__set_errno (ENOENT);
return -1;
}
static const char procfd[] = "/proc/self/fd/%d/%s";
/* Buffer for the path name we are going to use. It consists of
- the string /proc/self/fd/
- the file descriptor number
- the file name provided.
The final NUL is included in the sizeof. A bit of overhead
due to the format elements compensates for possible negative
numbers. */
size_t buflen = sizeof (procfd) + sizeof (int) * 3 + filelen;
buf = alloca (buflen);
__snprintf (buf, buflen, procfd, fd, file);
file = buf;
}
# if __ASSUME_STAT64_SYSCALL == 0
struct kernel_stat kst;
# endif
if (vers == _STAT_VER_KERNEL)
{
if (flag & AT_SYMLINK_NOFOLLOW)
result = INTERNAL_SYSCALL (lstat, err, 2, CHECK_STRING (file),
CHECK_1 ((struct kernel_stat *) st));
else
result = INTERNAL_SYSCALL (stat, err, 2, CHECK_STRING (file),
CHECK_1 ((struct kernel_stat *) st));
goto out;
}
# if __ASSUME_STAT64_SYSCALL > 0
if (flag & AT_SYMLINK_NOFOLLOW)
result = INTERNAL_SYSCALL (lstat64, err, 2, CHECK_STRING (file),
__ptrvalue (&st64));
else
result = INTERNAL_SYSCALL (stat64, err, 2, CHECK_STRING (file),
__ptrvalue (&st64));
if (__builtin_expect (!INTERNAL_SYSCALL_ERROR_P (result, err), 1))
return __xstat32_conv (vers, &st64, st);
# else
# if defined __NR_stat64
/* To support 32 bit UIDs, we have to use stat64. The normal stat
call only returns 16 bit UIDs. */
if (! __have_no_stat64)
{
if (flag & AT_SYMLINK_NOFOLLOW)
result = INTERNAL_SYSCALL (lstat64, err, 2, CHECK_STRING (file),
__ptrvalue (&st64));
else
result = INTERNAL_SYSCALL (stat64, err, 2, CHECK_STRING (file),
__ptrvalue (&st64));
if (__builtin_expect (!INTERNAL_SYSCALL_ERROR_P (result, err), 1))
result = __xstat32_conv (vers, &st64, st);
if (__builtin_expect (!INTERNAL_SYSCALL_ERROR_P (result, err), 1)
|| INTERNAL_SYSCALL_ERRNO (result, err) != ENOSYS)
goto out;
__have_no_stat64 = 1;
}
# endif
if (flag & AT_SYMLINK_NOFOLLOW)
result = INTERNAL_SYSCALL (lstat, err, 2, CHECK_STRING (file),
__ptrvalue (&kst));
else
result = INTERNAL_SYSCALL (stat, err, 2, CHECK_STRING (file),
__ptrvalue (&kst));
if (__builtin_expect (!INTERNAL_SYSCALL_ERROR_P (result, err), 1))
return __xstat_conv (vers, &kst, st);
# endif /* __ASSUME_STAT64_SYSCALL */
out:
if (__builtin_expect (INTERNAL_SYSCALL_ERROR_P (result, err), 0))
{
__atfct_seterrno (INTERNAL_SYSCALL_ERRNO (result, err), fd, buf);
result = -1;
}
return result;
#endif
}
libc_hidden_def (__fxstatat)
#ifdef XSTAT_IS_XSTAT64
# undef __fxstatat64
strong_alias (__fxstatat, __fxstatat64);
libc_hidden_ver (__fxstatat, __fxstatat64)
#endif