glibc/sysdeps/unix/sysv/linux/xstatover.h

68 lines
2.0 KiB
C

/* Overflow tests for stat, statfs, and lseek functions.
Copyright (C) 2020-2023 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
<https://www.gnu.org/licenses/>. */
#include <sys/stat.h>
#include <sys/statfs.h>
/* 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;
}
static inline int stat_overflow (struct stat *buf)
{
#if defined __INO_T_MATCHES_INO64_T || !STAT_IS_KERNEL_STAT
return 0;
#else
if (buf->__st_ino_pad == 0 && buf->__st_size_pad == 0
&& buf->__st_blocks_pad == 0)
return 0;
__set_errno (EOVERFLOW);
return -1;
#endif
}
/* Note that f_files and f_ffree may validly be a sign-extended -1. */
static inline int statfs_overflow (struct statfs *buf)
{
#if __STATFS_MATCHES_STATFS64 || !STAT_IS_KERNEL_STAT
return 0;
#else
if (buf->__f_blocks_pad == 0 && buf->__f_bfree_pad == 0
&& buf->__f_bavail_pad == 0
&& (buf->__f_files_pad == 0
|| (buf->f_files == -1U && buf->__f_files_pad == -1))
&& (buf->__f_ffree_pad == 0
|| (buf->f_ffree == -1U && buf->__f_ffree_pad == -1)))
return 0;
__set_errno (EOVERFLOW);
return -1;
#endif
}