| /* Linux lseek implementation, 32 bits off_t. |
| Copyright (C) 2016-2018 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, see |
| <http://www.gnu.org/licenses/>. */ |
| |
| #include <unistd.h> |
| #include <stdint.h> |
| #include <sys/types.h> |
| #include <sysdep.h> |
| #include <errno.h> |
| |
| #ifndef __OFF_T_MATCHES_OFF64_T |
| |
| /* Test for overflows of structures where we ask the kernel to fill them |
| in with standard 64-bit syscalls but return them through APIs that |
| only expose the low 32 bits of some fields. */ |
| |
| static inline off_t lseek_overflow (loff_t res) |
| { |
| off_t retval = (off_t) res; |
| if (retval == res) |
| return retval; |
| |
| __set_errno (EOVERFLOW); |
| return (off_t) -1; |
| } |
| |
| off_t |
| __lseek (int fd, off_t offset, int whence) |
| { |
| # ifdef __NR__llseek |
| loff_t res; |
| int rc = INLINE_SYSCALL_CALL (_llseek, fd, |
| (long) (((uint64_t) (offset)) >> 32), |
| (long) offset, &res, whence); |
| return rc ?: lseek_overflow (res); |
| # else |
| return INLINE_SYSCALL_CALL (lseek, fd, offset, whence); |
| # endif |
| } |
| libc_hidden_def (__lseek) |
| weak_alias (__lseek, lseek) |
| strong_alias (__lseek, __libc_lseek) |
| #endif /* __OFF_T_MATCHES_OFF64_T */ |
