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71aadfb8ae
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>
68 lines
2.0 KiB
C
68 lines
2.0 KiB
C
/* Overflow tests for stat, statfs, and lseek functions.
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Copyright (C) 2020 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library. If not, see
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<https://www.gnu.org/licenses/>. */
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#include <sys/stat.h>
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#include <sys/statfs.h>
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/* Test for overflows of structures where we ask the kernel to fill them
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in with standard 64-bit syscalls but return them through APIs that
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only expose the low 32 bits of some fields. */
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static inline off_t lseek_overflow (loff_t res)
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{
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off_t retval = (off_t) res;
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if (retval == res)
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return retval;
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__set_errno (EOVERFLOW);
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return (off_t) -1;
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}
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static inline int stat_overflow (struct stat *buf)
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{
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#if defined __INO_T_MATCHES_INO64_T || !STAT_IS_KERNEL_STAT
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return 0;
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#else
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if (buf->__st_ino_pad == 0 && buf->__st_size_pad == 0
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&& buf->__st_blocks_pad == 0)
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return 0;
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__set_errno (EOVERFLOW);
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return -1;
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#endif
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}
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/* Note that f_files and f_ffree may validly be a sign-extended -1. */
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static inline int statfs_overflow (struct statfs *buf)
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{
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#if __STATFS_MATCHES_STATFS64 || !STAT_IS_KERNEL_STAT
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return 0;
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#else
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if (buf->__f_blocks_pad == 0 && buf->__f_bfree_pad == 0
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&& buf->__f_bavail_pad == 0
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&& (buf->__f_files_pad == 0
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|| (buf->f_files == -1U && buf->__f_files_pad == -1))
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&& (buf->__f_ffree_pad == 0
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|| (buf->f_ffree == -1U && buf->__f_ffree_pad == -1)))
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return 0;
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__set_errno (EOVERFLOW);
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return -1;
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#endif
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}
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