Joseph Myers
809fdf0d23
Remove __ASSUME_ATFCTS conditionals in sysdeps/unix/sysv/linux/.
This patch cleans up for __ASSUME_ATFCTS now always being true for the supported Linux kernel versions by removing conditional code in sysdeps/unix/sysv/linux. Several fchownat.c files that were only present because of differences in the fallback syscalls used (depending on the architecture-specific names of chown-related syscalls for 32-bit uids) are removed. Files that looks like they could be replaced by syscalls.list entries have the standard "Consider moving to syscalls.list." comment (see bug 14138) added. Conditionals on the relevant __NR_* syscall numbers being defined are also removed, since my analysis indicated that the relevant syscalls are always defined for all relevant kernel versions using any affected file. Much of the removed fallback code had unbounded stack allocations, so this reduces the number of cases to consider for anyone reviewing uses of alloca and VLAs in glibc. There remain tests of __ASSUME_ATFCTS in io/openat.c (to determine whether to define __have_atfcts) and sysdeps/posix/getcwd.c (which also uses __have_atfcts); thus, the definition of __ASSUME_ATFCTS remains in kernel-features.h. The logical condition relevant there is whether openat64_not_cancel_3 is known to work. Hurd doesn't use this version of getcwd at all, so the conditionals in getcwd.c are always true in glibc. However, this code is also used in gnulib. So the best way to deal with the conditionals there may be for gnulib people to deal with merging all relevant changes in both directions between the glibc and gnulib versions of this file, at the end of which the openat conditionals should be in whatever form is best for gnulib, and hardcoded in the _LIBC case to having openat supported. Tested by comparing before-and-after disassembly of installed (stripped) shared libraries, on x86_64 and x86. On x86 the patch made no change to the disassembly; on x86_64, the only changes were in readlinkat, where formerly the return value from the readlinkat syscall was stored in an int variable before being converted to ssize_t for the return, and now the return value is returned directly without truncation to int. I think it's clearly correct not to truncate the return value (although I also think the truncation would not have been a user-visible bug because the kernel would never have returned a value it could have affected). * include/fcntl.h (__atfct_seterrno): Remove prototype. (__atfct_seterrno_2): Likewise. * sysdeps/unix/sysv/linux/alpha/dl-fxstatat64.c: Do not include <kernel-features.h>. (__ASSUME_ATFCTS): Do not undefine and redefine. * sysdeps/unix/sysv/linux/alpha/fxstatat.c [__ASSUME_ATFCTS] (__have_atfcts): Remove conditional definition. (__fxstatat([__NR_fstatat64]: Make code unconditional. (__fxstatat) [!__ASSUME_ATFCTS]: Remove conditional code and code unreachable if [__ASSUME_ATFCTS]. * sysdeps/unix/sysv/linux/dl-fxstatat64.c (__ASSUME_ATFCTS): Do not undefine and redefine. * sysdeps/unix/sysv/linux/faccessat.c: Do not include <kernel-features.h>. (faccessat) [__NR_faccessat]: Make code unconditional. (faccessat) [!__ASSUME_ATFCTS]: Remove conditional code. * sysdeps/unix/sysv/linux/fchmodat.c: Do not include <kernel-features.h>. (fchmodat) [__NR_fchmodat]: Make code unconditional. (fchmodat) [!__ASSUME_ATFCTS]: Remove conditional code. * sysdeps/unix/sysv/linux/fchownat.c: Do not include <kernel-features.h>. (fchownat) [__NR_fchownat]: Make code unconditional. (fchownat) [!__ASSUME_ATFCTS]: Remove conditional code. * sysdeps/unix/sysv/linux/futimesat.c: Do not include <kernel-features.h>. (futimesat) [__NR_futimesat]: Make code unconditional. (futimesat) [!__ASSUME_ATFCTS]: Remove conditional code. * sysdeps/unix/sysv/linux/fxstatat.c: Do not include <kernel-features.h>. (__fxstatat) [__NR_newfstatat]: Make code unconditional. (__fxstatat) [!__ASSUME_ATFCTS]: Remove conditional code. * sysdeps/unix/sysv/linux/fxstatat64.c: Do not include <kernel-features.h>. (__fxstatat64) [__NR_fstatat64]: Make code unconditional. (__fxstatat64) [!__ASSUME_ATFCTS]: Remove conditional code. * sysdeps/unix/sysv/linux/i386/fchownat.c: Remove file. * sysdeps/unix/sysv/linux/i386/fxstatat.c: Do not include <kernel-features.h>. (__fxstatat) [__NR_fstatat64]: Make code unconditional. (__fxstatat) [!__ASSUME_ATFCTS]: Remove conditional code. * sysdeps/unix/sysv/linux/linkat.c: Do not include <kernel-features.h>. (linkat) [__NR_linkat]: Make code unconditional. (linkat) [!__ASSUME_ATFCTS]: Remove conditional code. * sysdeps/unix/sysv/linux/m68k/fchownat.c: Remove file. * sysdeps/unix/sysv/linux/mips/mips64/fxstatat64.c: Do not include <kernel-features.h>. (__fxstatat64) [__NR_newfstatat]: Make code unconditional. (__fxstatat64) [!__ASSUME_ATFCTS]: Remove conditional code. * sysdeps/unix/sysv/linux/mkdirat.c: Do not include <kernel-features.h>. (mkdirat) [__NR_mkdirat]: Make code unconditional. (mkdirat) [!__ASSUME_ATFCTS]: Remove conditional code. * sysdeps/unix/sysv/linux/openat.c: Do not include <kernel-features.h>. [!__ASSUME_ATFCTS] (__atfct_seterrno): Remove function. [!__ASSUME_ATFCTS] (__have_atfcts): Remove variable. (OPENAT_NOT_CANCEL) [__NR_openat]: Make code unconditional. (OPENAT_NOT_CANCEL) [!__ASSUME_ATFCTS]: Remove conditional code. * sysdeps/unix/sysv/linux/powerpc/fchownat.c: Remove file. * sysdeps/unix/sysv/linux/readlinkat.c: Do not include <kernel-features.h>. (readlinkat) [__NR_readlinkat]: Make code unconditional. (readlinkat) [!__ASSUME_ATFCTS]: Remove conditional code. Return result of INLINE_SYSCALL directly, not via int variable. * sysdeps/unix/sysv/linux/renameat.c: Do not include <kernel-features.h>. [!__ASSUME_ATFCTS] (__atfct_seterrno_2): Remove function. (renameat) [__NR_renameat]: Make code unconditional. (renameat) [!__ASSUME_ATFCTS]: Remove conditional code. * sysdeps/unix/sysv/linux/s390/s390-32/fchownat.c: Remove file. * sysdeps/unix/sysv/linux/sh/fchownat.c: Remove file. * sysdeps/unix/sysv/linux/sparc/sparc32/fchownat.c: Remove file. * sysdeps/unix/sysv/linux/sparc/sparc64/dl-fxstatat64.c (__ASSUME_ATFCTS): Do not undefine and redefine. * sysdeps/unix/sysv/linux/symlinkat.c: Do not include <kernel-features.h>. (symlinkat) [__NR_symlinkat]: Make code unconditional. (symlinkat) [!__ASSUME_ATFCTS]: Remove conditional code. * sysdeps/unix/sysv/linux/unlinkat.c: Do not include <kernel-features.h>. (unlinkat) [__NR_unlinkat]: Make code unconditional. (unlinkat) [!__ASSUME_ATFCTS]: Remove conditional code. * sysdeps/unix/sysv/linux/wordsize-64/dl-fxstatat64.c (__ASSUME_ATFCTS): Do not undefine and redefine. * sysdeps/unix/sysv/linux/wordsize-64/fxstatat.c: Do not include <kernel-features.h>. (__fxstatat) [__NR_newfstatat]: Make code unconditional. (__fxstatat) [!__ASSUME_ATFCTS]: Remove conditional code. * sysdeps/unix/sysv/linux/xmknodat.c: Do not include <kernel-features.h>. (__xmknodat) [__NR_mknodat]: Make code unconditional. (__xmknodat) [!__ASSUME_ATFCTS]: Remove conditional code.
…
…
…
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. The current GNU/Hurd support requires out-of-tree patches that will eventually be incorporated into an official GNU C Library release. When working with Linux kernels, this version of the GNU C Library requires Linux kernel version 2.6.32 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 arm-*-linux-gnueabi hppa-*-linux-gnu Not currently functional without patches. 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 sh[34]-*-linux-gnu sparc*-*-linux-gnu sparc64*-*-linux-gnu tilegx-*-linux-gnu tilepro-*-linux-gnu The code for other CPU configurations supported by volunteers outside of the core glibc maintenance effort is contained in the `ports' add-on, located in the `ports' subdirectory of the source tree. If you are interested in doing a port, please contact the glibc maintainers; see http://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 http://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 http://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., 2000-2013, indicating that every year in the range, inclusive, is a copyrightable year that would otherwise be listed individually.
Description
Languages
C
75%
Assembly
14.8%
Roff
3.5%
Pawn
3.4%
Makefile
0.8%
Other
2.3%