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6ddd37a4 | 1 | /* Copyright (C) 1997-2000,2002,2003,2004,2006 Free Software Foundation, Inc. |
af6f3906 UD |
2 | This file is part of the GNU C Library. |
3 | Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997. | |
4 | ||
5 | The GNU C Library is free software; you can redistribute it and/or | |
41bdb6e2 AJ |
6 | modify it under the terms of the GNU Lesser General Public |
7 | License as published by the Free Software Foundation; either | |
8 | version 2.1 of the License, or (at your option) any later version. | |
af6f3906 UD |
9 | |
10 | The GNU C Library is distributed in the hope that it will be useful, | |
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
41bdb6e2 | 13 | Lesser General Public License for more details. |
af6f3906 | 14 | |
41bdb6e2 AJ |
15 | You should have received a copy of the GNU Lesser General Public |
16 | License along with the GNU C Library; if not, write to the Free | |
17 | Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA | |
18 | 02111-1307 USA. */ | |
af6f3906 | 19 | |
cd682e15 | 20 | #include <assert.h> |
d71b808a | 21 | #include <errno.h> |
741845cb | 22 | #include <endian.h> |
af6f3906 | 23 | #include <unistd.h> |
0dee6738 | 24 | |
6ee8d334 | 25 | #include <sysdep-cancel.h> |
36ecfe56 | 26 | #include <sys/syscall.h> |
4bbb61e4 | 27 | #include <bp-checks.h> |
36ecfe56 | 28 | |
6ddd37a4 | 29 | #include <kernel-features.h> |
958f238f | 30 | |
4b172769 RM |
31 | #ifdef __NR_pread64 /* Newer kernels renamed but it's the same. */ |
32 | # ifdef __NR_pread | |
33 | # error "__NR_pread and __NR_pread64 both defined???" | |
34 | # endif | |
35 | # define __NR_pread __NR_pread64 | |
36 | #endif | |
37 | ||
958f238f | 38 | #if defined __NR_pread || __ASSUME_PREAD_SYSCALL > 0 |
af6f3906 | 39 | |
958f238f | 40 | # if __ASSUME_PREAD_SYSCALL == 0 |
d71b808a UD |
41 | static ssize_t __emulate_pread (int fd, void *buf, size_t count, |
42 | off_t offset) internal_function; | |
958f238f | 43 | # endif |
d71b808a UD |
44 | |
45 | ||
6ee8d334 | 46 | static ssize_t |
ce6e047f UD |
47 | #ifdef NO_CANCELLATION |
48 | inline __attribute ((always_inline)) | |
49 | #endif | |
6ee8d334 | 50 | do_pread (int fd, void *buf, size_t count, off_t offset) |
af6f3906 | 51 | { |
d71b808a UD |
52 | ssize_t result; |
53 | ||
54 | /* First try the syscall. */ | |
cd682e15 | 55 | assert (sizeof (offset) == 4); |
4bbb61e4 | 56 | result = INLINE_SYSCALL (pread, 5, fd, CHECK_N (buf, count), count, |
cd682e15 | 57 | __LONG_LONG_PAIR (offset >> 31, offset)); |
958f238f | 58 | # if __ASSUME_PREAD_SYSCALL == 0 |
d71b808a UD |
59 | if (result == -1 && errno == ENOSYS) |
60 | /* No system call available. Use the emulation. */ | |
61 | result = __emulate_pread (fd, buf, count, offset); | |
958f238f | 62 | # endif |
d71b808a UD |
63 | |
64 | return result; | |
af6f3906 UD |
65 | } |
66 | ||
6ee8d334 UD |
67 | |
68 | ssize_t | |
69 | __libc_pread (fd, buf, count, offset) | |
70 | int fd; | |
71 | void *buf; | |
72 | size_t count; | |
73 | off_t offset; | |
74 | { | |
75 | if (SINGLE_THREAD_P) | |
76 | return do_pread (fd, buf, count, offset); | |
77 | ||
78 | int oldtype = LIBC_CANCEL_ASYNC (); | |
79 | ||
80 | ssize_t result = do_pread (fd, buf, count, offset); | |
81 | ||
82 | LIBC_CANCEL_RESET (oldtype); | |
83 | ||
84 | return result; | |
85 | } | |
86 | ||
bef24895 | 87 | strong_alias (__libc_pread, __pread) |
778c59c8 | 88 | weak_alias (__libc_pread, pread) |
d71b808a | 89 | |
778c59c8 | 90 | # define __libc_pread(fd, buf, count, offset) \ |
d71b808a | 91 | static internal_function __emulate_pread (fd, buf, count, offset) |
36ecfe56 | 92 | #endif |
958f238f UD |
93 | |
94 | #if __ASSUME_PREAD_SYSCALL == 0 | |
95 | # include <sysdeps/posix/pread.c> | |
96 | #endif |