mirror of
https://sourceware.org/git/glibc.git
synced 2025-09-11 12:10:50 +03:00
4f40e6adc4
The LFS support is implemented on lxstat64.c, instead of lxstat.c for
64-bit architectures. The xstat.c implements the non-LFS and it is
a no-op for !XSTAT_IS_XSTAT64.
The generic non-LFS implementation handles two cases:
1. New kABIs which uses generic pre 64-bit time Linux ABI (csky and
nios): it issues __NR_fstat64 with AT_SYMLINK_NOFOLLOW plus handles
the possible overflow off 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_lstat, otherwise it isseus __NR_lstat64 and convert
to non-LFS stat struct and handle possible overflows on st_ino,
st_size, or st_blocks.
Also 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, sparc64, x86_64): it
issues __NR_lstat for _STAT_VER_KERNEL or _STAT_VER_LINUX.
1.2. Old 64-bit kABI with defines __NR_lstat64 instead of __NR_lstat
(sparc64): it issues __NR_lstat for _STAT_VER_KERNEL or
__NR_lstat64 and convert to struct stat64.
1.3. New kABIs which uses generic 64-bit Linux ABI (aarch64 and
riscv64): it issues __NR_newfstatat with AT_SYMLINK_NOFOLLOW
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_lstat64.
Also, two special cases requires specific LFS implementations:
1. alpha: it requires to handle _STAT_VER_KERNEL64 to issue
__NR_lstat64 and use the kernel_stat with __NR_lstat otherwise.
2. mips64: as for non-LFS implementation its ABIs differ from
glibc exported one, which requires a 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>
This directory contains the sources of the GNU C Library. See the file "version.h" for what release version you have. The GNU C Library is the standard system C library for all GNU systems, and is an important part of what makes up a GNU system. It provides the system API for all programs written in C and C-compatible languages such as C++ and Objective C; the runtime facilities of other programming languages use the C library to access the underlying operating system. In GNU/Linux systems, the C library works with the Linux kernel to implement the operating system behavior seen by user applications. In GNU/Hurd systems, it works with a microkernel and Hurd servers. The GNU C Library implements much of the POSIX.1 functionality in the GNU/Hurd system, using configurations i[4567]86-*-gnu. When working with Linux kernels, this version of the GNU C Library requires Linux kernel version 3.2 or later. Also note that the shared version of the libgcc_s library must be installed for the pthread library to work correctly. The GNU C Library supports these configurations for using Linux kernels: aarch64*-*-linux-gnu alpha*-*-linux-gnu arc*-*-linux-gnu arm-*-linux-gnueabi csky-*-linux-gnuabiv2 hppa-*-linux-gnu i[4567]86-*-linux-gnu x86_64-*-linux-gnu Can build either x86_64 or x32 ia64-*-linux-gnu m68k-*-linux-gnu microblaze*-*-linux-gnu mips-*-linux-gnu mips64-*-linux-gnu powerpc-*-linux-gnu Hardware or software floating point, BE only. powerpc64*-*-linux-gnu Big-endian and little-endian. s390-*-linux-gnu s390x-*-linux-gnu riscv32-*-linux-gnu riscv64-*-linux-gnu sh[34]-*-linux-gnu sparc*-*-linux-gnu sparc64*-*-linux-gnu If you are interested in doing a port, please contact the glibc maintainers; see https://www.gnu.org/software/libc/ for more information. See the file INSTALL to find out how to configure, build, and install the GNU C Library. You might also consider reading the WWW pages for the C library at https://www.gnu.org/software/libc/. The GNU C Library is (almost) completely documented by the Texinfo manual found in the `manual/' subdirectory. The manual is still being updated and contains some known errors and omissions; we regret that we do not have the resources to work on the manual as much as we would like. For corrections to the manual, please file a bug in the `manual' component, following the bug-reporting instructions below. Please be sure to check the manual in the current development sources to see if your problem has already been corrected. Please see https://www.gnu.org/software/libc/bugs.html for bug reporting information. We are now using the Bugzilla system to track all bug reports. This web page gives detailed information on how to report bugs properly. The GNU C Library is free software. See the file COPYING.LIB for copying conditions, and LICENSES for notices about a few contributions that require these additional notices to be distributed. License copyright years may be listed using range notation, e.g., 1996-2015, indicating that every year in the range, inclusive, is a copyrightable year that would otherwise be listed individually.