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

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linux: Consolidate xstat{64} The LFS support is implemented on xstat64.c, instead of xstat.c for 64-bit architectures. The xstat.c implements the non-LFS it is no-op for !XSTAT_IS_XSTAT64. The generic non-LFS implementation handle two cases: 1. New kABIs which uses generic pre 64-bit time Linux ABI (csky and nios): it issues __NR_fstat64 plus handle the overflow on st_ino, st_size, or st_blocks. It only handles _STAT_VER_KERNEL. 2. Old KABIs with old non-LFS support (arm, i386, hppa, m68k, microblaze, s390, sh, powerpc, and sparc32). For _STAT_VER_KERNEL it issues __NR_stat, otherwise it issues __NR_stat64 and convert to non-LFS stat struct handling possible overflows on st_ino, st_size, or st_blocks. Also the non-LFS mips is an outlier and it has its own implementation since _STAT_VER_LINUX requires a different conversion function (it uses the kernel_stat as the syscall argument since its exported ABI is different than the kernel one for both non-LFS and LFS implementation). The generic LFS implementation handles multiple cases: 1. XSTAT_IS_XSTAT64 being 1: 1.1. Old 64-bit kABI (ia64, powerpc64*, s390x, x86_64): it issues __NR_stat for _STAT_VER_KERNEL or _STAT_VER_LINUX. 1.2. Old 64-bit kABI with defines __NR_stat64 instead of __NR_stat (sparc64): it issues __NR_stat for _STAT_VER_KERNEL or __NR_stat64 and convert to struct stat64. 1.3. New kABIs which uses generic 64-bit Linux ABI (aarch64 and riscv64): it issues __NR_newfstatat and only for _STAT_VER_KERNEL. 1.4. New 32-bit kABIs with only 64-bit time_t support (arc and riscv32): it issues __NR_statx and covert to struct stat64. 2. Old ABIs with XSTAT_IS_XSTAT64 being 0: 2.1. New kABIs which uses generic pre 64-bit time Linux ABI (csky and nios2): it issues __NR_fstatat64 for _STAT_VER_KERNEL. 2.2. Old kABIs with old non-LFS support (arm, i386, hppa, m68k, microblaze, s390, sh, mips32, powerpc32, and sparc32): it issues __NR_stat64. Also, two special cases requires specific LFS implementations: 1. alpha: it requires to handle _STAT_VER_KERNEL64 to call __NR_stat64 or use the kernel_stat with __NR_stat otherwise. 2. mips64: as for non-LFS implementation its ABIs differ from glibc exported one, which requires an specific conversion function to handle the kernel_stat. Checked with a build for all affected ABIs. I also checked on x86_64, i686, powerpc, powerpc64le, sparcv9, sparc64, s390, and s390x. Reviewed-by: Lukasz Majewski <lukma@denx.de>
2020-07-13 12:13:12 +00:00
/* Overflow tests for stat, statfs, and lseek functions.
Copyright (C) 2020 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
}