summaryrefslogtreecommitdiff
path: root/sysdeps/unix/sysv/linux/fxstatat64.c
blob: cb932b8e59d707b46689b457e31fa45ab56c5a42 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
/* Copyright (C) 2005,2006 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.  */

#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>

#if __ASSUME_STAT64_SYSCALL == 0
# include <xstatconv.h>
#endif

#ifdef __NR_stat64
# if  __ASSUME_STAT64_SYSCALL == 0
/* The variable is shared between all wrappers around *stat64 calls.
   This is the definition.  */
extern int __have_no_stat64;
# endif
#endif

/* Get information about the file NAME in BUF.  */

int
__fxstatat64 (int vers, int fd, const char *file, struct stat64 *st, int flag)
{
  if (__builtin_expect (vers != _STAT_VER_LINUX, 0))
    {
      __set_errno (EINVAL);
      return -1;
    }

  int result;
  INTERNAL_SYSCALL_DECL (err);

#ifdef __NR_fstatat64
# ifndef __ASSUME_ATFCTS
  if (__have_atfcts >= 0)
# endif
    {
      result = INTERNAL_SYSCALL (fstatat64, err, 4, fd, file, st, 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 0;
	else
	  {
	    __set_errno (INTERNAL_SYSCALL_ERRNO (result, err));
	    return -1;
	  }
    }
#endif

#ifndef __ASSUME_ATFCTS
  if (flag & ~AT_SYMLINK_NOFOLLOW)
    {
      __set_errno (EINVAL);
      return -1;
    }

  char *buf = NULL;

  if (fd != AT_FDCWD && file[0] != '/')
    {
      size_t filelen = strlen (file);
      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
  if (flag & AT_SYMLINK_NOFOLLOW)
    result = INTERNAL_SYSCALL (lstat64, err, 2, CHECK_STRING (file),
			       CHECK_1 (st));
  else
    result = INTERNAL_SYSCALL (stat64, err, 2, CHECK_STRING (file),
			       CHECK_1 (st));
  if (__builtin_expect (!INTERNAL_SYSCALL_ERROR_P (result, err), 1))
    {
#  if defined _HAVE_STAT64___ST_INO && __ASSUME_ST_INO_64_BIT == 0
      if (st->__st_ino != (__ino_t) st->st_ino)
	st->st_ino = st->__st_ino;
#  endif
      return result;
    }
# else
  struct kernel_stat kst;
#  ifdef __NR_stat64
  if (! __have_no_stat64)
    {
      if (flag & AT_SYMLINK_NOFOLLOW)
	result = INTERNAL_SYSCALL (lstat64, err, 2, CHECK_STRING (file),
				   CHECK_1 (st));
      else
	result = INTERNAL_SYSCALL (stat64, err, 2, CHECK_STRING (file),
				   CHECK_1 (st));

      if (__builtin_expect (!INTERNAL_SYSCALL_ERROR_P (result, err), 1))
	{
#   if defined _HAVE_STAT64___ST_INO && __ASSUME_ST_INO_64_BIT == 0
	  if (st->__st_ino != (__ino_t) st->st_ino)
	    st->st_ino = st->__st_ino;
#   endif
	  return result;
	}
      if (INTERNAL_SYSCALL_ERRNO (result, err) != ENOSYS)
	goto fail;

      __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 __xstat64_conv (vers, &kst, st);

 fail:
# endif
  __atfct_seterrno (INTERNAL_SYSCALL_ERRNO (result, err), fd, buf);

  return -1;
#endif
}
libc_hidden_def (__fxstatat64)