projects / thirdparty / glibc.git / blame
| Commit | Line | Data |
|---|---|---|
| 3c7f1f59 | 1 | /* Linux lseek implementation, 32 bits off_t. |
| 04277e02 | 2 | Copyright (C) 2016-2019 Free Software Foundation, Inc. |
| a63c7fa1 | 3 | This file is part of the GNU C Library. |
| a63c7fa1 CM |
4 | |
| 5 | The GNU C Library is free software; you can redistribute it and/or | |
| 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. | |
| 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 | |
| 13 | Lesser General Public License for more details. | |
| 14 | ||
| 15 | You should have received a copy of the GNU Lesser General Public | |
| ab84e3ff | 16 | License along with the GNU C Library. If not, see |
| 5a82c748 | 17 | <https://www.gnu.org/licenses/>. */ |
| a63c7fa1 | 18 | |
| a63c7fa1 | 19 | #include <unistd.h> |
| 3c7f1f59 | 20 | #include <stdint.h> |
| a63c7fa1 | 21 | #include <sys/types.h> |
| a63c7fa1 | 22 | #include <sysdep.h> |
| 3c7f1f59 AZ |
23 | #include <errno.h> |
| 24 | ||
| 25 | #ifndef __OFF_T_MATCHES_OFF64_T | |
| a63c7fa1 | 26 | |
| 3c7f1f59 AZ |
27 | /* Test for overflows of structures where we ask the kernel to fill them |
| 28 | in with standard 64-bit syscalls but return them through APIs that | |
| 29 | only expose the low 32 bits of some fields. */ | |
| 30 | ||
| 31 | static inline off_t lseek_overflow (loff_t res) | |
| 32 | { | |
| 33 | off_t retval = (off_t) res; | |
| 34 | if (retval == res) | |
| 35 | return retval; | |
| 36 | ||
| 37 | __set_errno (EOVERFLOW); | |
| 38 | return (off_t) -1; | |
| 39 | } | |
| a63c7fa1 CM |
40 | |
| 41 | off_t | |
| 42 | __lseek (int fd, off_t offset, int whence) | |
| 43 | { | |
| 3c7f1f59 | 44 | # ifdef __NR__llseek |
| a63c7fa1 | 45 | loff_t res; |
| 3c7f1f59 AZ |
46 | int rc = INLINE_SYSCALL_CALL (_llseek, fd, |
| 47 | (long) (((uint64_t) (offset)) >> 32), | |
| 48 | (long) offset, &res, whence); | |
| a63c7fa1 | 49 | return rc ?: lseek_overflow (res); |
| 3c7f1f59 AZ |
50 | # else |
| 51 | return INLINE_SYSCALL_CALL (lseek, fd, offset, whence); | |
| 52 | # endif | |
| a63c7fa1 CM |
53 | } |
| 54 | libc_hidden_def (__lseek) | |
| 55 | weak_alias (__lseek, lseek) | |
| 56 | strong_alias (__lseek, __libc_lseek) | |
| 3c7f1f59 | 57 | #endif /* __OFF_T_MATCHES_OFF64_T */ |