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5e7698c6f1
This patch reduces duplication between different architectures' kernel-features.h files by making the architecture-independent file define various macros unconditionally (instead of only for a particular list of architectures), with the architecture-specific files then undefining the macros if necessary. Specifically, __ASSUME_O_CLOEXEC (O_CLOEXEC flag to open) and __ASSUME_SOCK_CLOEXEC (SOCK_NONBLOCK and SOCK_CLOEXEC flags to socket) are supported on all architectures as of 2.6.32 or the minimum kernel version for the architecture if later. For __ASSUME_IN_NONBLOCK, __ASSUME_PIPE2, __ASSUME_EVENTFD2, __ASSUME_SIGNALFD4 and __ASSUME_DUP3, the relevant syscalls were added for alpha in 2.6.33 but otherwise the features are available as of 2.6.32. For __ASSUME_UTIMES, support is everywhere in 2.6.32 except for asm-generic architectures and hppa. Although those were the main cases of duplication among kernel-features.h files, some other cases of unnecessary definitions were also cleaned up: the hppa file defined various macros that were either no longer used at all, or defined by the main file by default anyway, the ia64 file had duplicative definitions of __ASSUME_PSELECT and __ASSUME_PPOLL, while mips had such a definition of __ASSUME_IPC64. Really, rather than being defined in the main file then undefined for asm-generic architectures, __ASSUME_UTIMES should become an hppa-specific macro. Given that __ASSUME_ATFCTS and __ASSUME_UTIMENSAT are now always true, the only live __ASSUME_UTIMES conditional is in sysdeps/unix/sysv/linux/utimes.c, which is not used for asm-generic architectures. I think the desired state would be an hppa-specific file (that includes sysdeps/unix/sysv/linux/utimes.c if __ASSUME_UTIMES, and otherwise has fallback code), with the fallback code being removed from the main utimes.c. But I think that's most reasonably a separate cleanup once __ASSUME_ATFCTS and __ASSUME_UTIMESAT have both had conditional code cleaned up. Given this patch, I think it's straightforward to move non-ex-ports architectures to having their own kernel-features.h files, like ex-ports architectures, rather than conditionals in the main file (i.e., such a move won't require the architecture-specific file to contain anything that isn't genuinely architecture-specific), and would encourage architecture maintainers to do so. Tested x86_64 that the installed shared libraries are unchanged by this patch. Note that on some architectures this *will* cause __ASSUME_* macros to be defined in cases where they weren't previously but should have been (but this is just optimization, not a fix to a user-visible bug, so doesn't need a bug report in Bugzilla). * sysdeps/unix/sysv/linux/kernel-features.h (__ASSUME_UTIMES): Define unconditionally. (__ASSUME_O_CLOEXEC): Likewise. (__ASSUME_SOCK_CLOEXEC): Likewise. (__ASSUME_IN_NONBLOCK): Likewise. (__ASSUME_PIPE2): Likewise. (__ASSUME_EVENTFD2): Likewise. (__ASSUME_SIGNALFD4): Likewise. (__ASSUME_DUP3): Likewise. * sysdeps/unix/sysv/linux/aarch64/kernel-features.h (__ASSUME_DUP3): Do not define. (__ASSUME_EVENTFD2): Likewise. (__ASSUME_IN_NONBLOCK): Likewise. (__ASSUME_O_CLOEXEC): Likewise. (__ASSUME_PIPE2): Likewise. (__ASSUME_SIGNALFD4): Likewise. (__ASSUME_SOCK_CLOEXEC): Likewise. (__ASSUME_UTIMES): Undefine. * sysdeps/unix/sysv/linux/alpha/kernel-features.h (__ASSUME_UTIMES): Do not define. (__ASSUME_O_CLOEXEC): Likewise. (__ASSUME_SOCK_CLOEXEC): Likewise. (__ASSUME_IN_NONBLOCK): Undefine if [__LINUX_KERNEL_VERSION < 0x020621] instead of defining if [__LINUX_KERNEL_VERSION >= 0x020621]. (__ASSUME_PIPE2): Likewise. (__ASSUME_EVENTFD2): Likewise. (__ASSUME_SIGNALFD4): Likewise. [__LINUX_KERNEL_VERSION < 0x020621] (__ASSUME_DUP3): Undefine. * sysdeps/unix/sysv/linux/arm/kernel-features.h (__ASSUME_UTIMES): Do not define. (__ASSUME_EVENTFD2): Likewise. (__ASSUME_SIGNALFD4): Likewise. * sysdeps/unix/sysv/linux/hppa/kernel-features.h (__ASSUME_32BITUIDS): Likewise. (__ASSUME_TRUNCATE64_SYSCALL): Likewise. (__ASSUME_IPC64): Likewise. (__ASSUME_ST_INO_64_BIT): Likewise. (__ASSUME_GETDENTS64_SYSCALL): Likewise. [__LINUX_KERNEL_VERSION < 0x030e00] (__ASSUME_UTIMES): Undefine. * sysdeps/unix/sysv/linux/ia64/kernel-features.h (__ASSUME_UTIMES): Do not define. (__ASSUME_PSELECT): Likewise. (__ASSUME_PPOLL): Likewise. (__ASSUME_O_CLOEXEC): Likewise. (__ASSUME_SOCK_CLOEXEC): Likewise. (__ASSUME_IN_NONBLOCK): Likewise. (__ASSUME_PIPE2): Likewise. (__ASSUME_EVENTFD2): Likewise. (__ASSUME_SIGNALFD4): Likewise. (__ASSUME_DUP3): Likewise. * sysdeps/unix/sysv/linux/m68k/kernel-features.h (__ASSUME_UTIMES): Likewise. (__ASSUME_O_CLOEXEC): Likewise. (__ASSUME_SOCK_CLOEXEC): Likewise. (__ASSUME_IN_NONBLOCK): Likewise. (__ASSUME_PIPE2): Likewise. (__ASSUME_EVENTFD2): Likewise. (__ASSUME_SIGNALFD4): Likewise. (__ASSUME_DUP3): Likewise. * sysdeps/unix/sysv/linux/microblaze/kernel-features.h (__ASSUME_UTIMES): Likewise. (__ASSUME_O_CLOEXEC): Likewise. (__ASSUME_SOCK_CLOEXEC): Likewise. (__ASSUME_IN_NONBLOCK): Likewise. (__ASSUME_PIPE2): Likewise. (__ASSUME_EVENTFD2): Likewise. (__ASSUME_SIGNALFD4): Likewise. (__ASSUME_DUP3): Likewise. * sysdeps/unix/sysv/linux/mips/kernel-features.h (__ASSUME_IPC64): Likewise. (__ASSUME_UTIMES): Likewise. (__ASSUME_EVENTFD2): Likewise. (__ASSUME_SIGNALFD4): Likewise. * sysdeps/unix/sysv/linux/tile/kernel-features.h (__ASSUME_O_CLOEXEC): Likewise. (__ASSUME_SOCK_CLOEXEC): Likewise. (__ASSUME_IN_NONBLOCK): Likewise. (__ASSUME_PIPE2): Likewise. (__ASSUME_EVENTFD2): Likewise. (__ASSUME_SIGNALFD4): Likewise. (__ASSUME_DUP3): Likewise. (__ASSUME_UTIMES): Undefine.
253 lines
9.1 KiB
C
253 lines
9.1 KiB
C
/* Set flags signalling availability of kernel features based on given
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kernel version number.
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Copyright (C) 1999-2014 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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<http://www.gnu.org/licenses/>. */
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/* This file must not contain any C code. At least it must be protected
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to allow using the file also in assembler files. */
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#ifndef __LINUX_KERNEL_VERSION
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/* We assume the worst; all kernels should be supported. */
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# define __LINUX_KERNEL_VERSION 0
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#endif
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/* We assume for __LINUX_KERNEL_VERSION the same encoding used in
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linux/version.h. I.e., the major, minor, and subminor all get a
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byte with the major number being in the highest byte. This means
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we can do numeric comparisons.
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In the following we will define certain symbols depending on
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whether the describes kernel feature is available in the kernel
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version given by __LINUX_KERNEL_VERSION. We are not always exactly
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recording the correct versions in which the features were
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introduced. If somebody cares these values can afterwards be
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corrected. */
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/* The sendfile syscall was introduced in 2.2.0. */
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#define __ASSUME_SENDFILE 1
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/* Some architectures use the socketcall multiplexer for some or all
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socket-related operations, via a socket.S file in glibc, instead of
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separate syscalls. __ASSUME_SOCKETCALL is defined for such
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architectures. */
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#if defined __i386__ \
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|| defined __powerpc__ \
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|| defined __s390__ \
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|| defined __sh__ \
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|| defined __sparc__
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# define __ASSUME_SOCKETCALL 1
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#endif
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/* Linux 2.3.39 introduced IPC64. Except for powerpc. Linux 2.4.0 on
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PPC introduced a correct IPC64. But PowerPC64 does not support a
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separate 64-bit syscall, already 64-bit. */
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#ifndef __powerpc64__
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# define __ASSUME_IPC64 1
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#endif
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/* The changed st_ino field appeared in 2.4.0-test6. However, SH is lame,
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and still does not have a 64-bit inode field. */
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#ifndef __sh__
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# define __ASSUME_ST_INO_64_BIT 1
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#endif
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/* The getdents64 syscall was introduced in 2.4.0-test7 (but later for
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MIPS n32). */
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#define __ASSUME_GETDENTS64_SYSCALL 1
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/* The statfs64 syscalls are available in 2.5.74 (but not for alpha). */
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#define __ASSUME_STATFS64 1
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/* The utimes syscall has been available for some architectures
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forever. For x86 it was introduced after 2.5.75, for x86-64,
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ppc, and ppc64 it was introduced in 2.6.0-test3, for s390 it was
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introduced in 2.6.21-rc5. */
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#define __ASSUME_UTIMES 1
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/* pselect/ppoll were introduced just after 2.6.16-rc1. On x86_64 and
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SH this appeared first in 2.6.19-rc1, on ia64 in 2.6.22-rc1. */
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#define __ASSUME_PSELECT 1
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#define __ASSUME_PPOLL 1
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/* The *at syscalls were introduced just after 2.6.16-rc1. On PPC
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they were introduced in 2.6.17-rc1, on SH in 2.6.19-rc1. */
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#define __ASSUME_ATFCTS 1
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/* Support for inter-process robust mutexes was added in 2.6.17 (but
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some architectures lack futex_atomic_cmpxchg_inatomic in some
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configurations). */
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#if !(defined __sparc__ && !defined __arch64__ && !defined __sparc_v9__)
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# define __ASSUME_SET_ROBUST_LIST 1
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#endif
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/* Pessimistically assume that 2.6.18 introduced real handling of
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large numbers of requests to readv and writev and that we don't
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need a fallback. It likely worked for much longer. */
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#define __ASSUME_COMPLETE_READV_WRITEV 1
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/* Support for PI futexes was added in 2.6.18 (but some architectures
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lack futex_atomic_cmpxchg_inatomic in some configurations). */
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#if !(defined __sparc__ && !defined __arch64__ && !defined __sparc_v9__)
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# define __ASSUME_FUTEX_LOCK_PI 1
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#endif
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/* Support for utimensat syscall was added in 2.6.22, on SH
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only after 2.6.22-rc1. */
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#define __ASSUME_UTIMENSAT 1
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/* Support for private futexes was added in 2.6.22. */
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#define __ASSUME_PRIVATE_FUTEX 1
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/* Support for fallocate was added in 2.6.23, on s390
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only after 2.6.23-rc1. */
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#define __ASSUME_FALLOCATE 1
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/* Support for various CLOEXEC and NONBLOCK flags was added in
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2.6.23. */
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#define __ASSUME_O_CLOEXEC 1
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/* Support for ADJ_OFFSET_SS_READ was added in 2.6.24. */
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#define __ASSUME_ADJ_OFFSET_SS_READ 1
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/* Support for various CLOEXEC and NONBLOCK flags was added in
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2.6.27. */
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#define __ASSUME_SOCK_CLOEXEC 1
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#define __ASSUME_IN_NONBLOCK 1
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#define __ASSUME_PIPE2 1
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#define __ASSUME_EVENTFD2 1
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#define __ASSUME_SIGNALFD4 1
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#define __ASSUME_DUP3 1
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/* Support for accept4 functionality was added in 2.6.28, but for some
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architectures using a separate syscall rather than socketcall that
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syscall was only added later, and some architectures first had
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socketcall support then a separate syscall. Define
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__ASSUME_ACCEPT4_SOCKETCALL if glibc uses socketcall on this
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architecture and accept4 is available through socketcall,
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__ASSUME_ACCEPT4_SYSCALL if it is available through a separate
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syscall, __ASSUME_ACCEPT4_SYSCALL_WITH_SOCKETCALL if it became
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available through a separate syscall at the same time as through
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socketcall, and __ASSUME_ACCEPT4 if the accept4 function is known
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to work. */
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#ifdef __ASSUME_SOCKETCALL
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# define __ASSUME_ACCEPT4_SOCKETCALL 1
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#endif
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/* The accept4 syscall was added for x86_64 and SPARC in 2.6.28, and
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for PowerPC and SH in 2.6.37. */
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#if (defined __x86_64__ || defined __sparc__) \
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|| (__LINUX_KERNEL_VERSION >= 0x020625 \
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&& (defined __powerpc__ || defined __sh__))
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# define __ASSUME_ACCEPT4_SYSCALL 1
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#endif
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#ifdef __sparc__
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# define __ASSUME_ACCEPT4_SYSCALL_WITH_SOCKETCALL 1
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#endif
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#if defined __ASSUME_ACCEPT4_SOCKETCALL || defined __ASSUME_ACCEPT4_SYSCALL
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# define __ASSUME_ACCEPT4 1
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#endif
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/* Support for the FUTEX_CLOCK_REALTIME flag was added in 2.6.29. */
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#define __ASSUME_FUTEX_CLOCK_REALTIME 1
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/* Support for the AT_RANDOM auxiliary vector entry was added in 2.6.29. */
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#define __ASSUME_AT_RANDOM 1
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/* Support for preadv and pwritev was added in 2.6.30. */
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#define __ASSUME_PREADV 1
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#define __ASSUME_PWRITEV 1
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/* Support for FUTEX_*_REQUEUE_PI was added in 2.6.31 (but some
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architectures lack futex_atomic_cmpxchg_inatomic in some
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configurations). */
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#if !(defined __sparc__ && !defined __arch64__ && !defined __sparc_v9__)
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# define __ASSUME_REQUEUE_PI 1
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#endif
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/* Support for F_GETOWN_EX was introduced in 2.6.32. */
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#define __ASSUME_F_GETOWN_EX 1
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/* Support for recvmmsg functionality was added in 2.6.33. The macros
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defined correspond to those for accept4. */
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#if __LINUX_KERNEL_VERSION >= 0x020621 && defined __ASSUME_SOCKETCALL
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# define __ASSUME_RECVMMSG_SOCKETCALL 1
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#endif
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/* The recvmmsg syscall was added for i386, x86_64 and SPARC in
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2.6.33, and for PowerPC and SH in 2.6.37. */
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#if (__LINUX_KERNEL_VERSION >= 0x020621 \
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&& (defined __i386__ || defined __x86_64__ || defined __sparc__)) \
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|| (__LINUX_KERNEL_VERSION >= 0x020625 \
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&& (defined __powerpc__ || defined __sh__))
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# define __ASSUME_RECVMMSG_SYSCALL 1
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#endif
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#if defined __i386__ || defined __sparc__
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# define __ASSUME_RECVMMSG_SYSCALL_WITH_SOCKETCALL 1
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#endif
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#if defined __ASSUME_RECVMMSG_SOCKETCALL || defined __ASSUME_RECVMMSG_SYSCALL
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# define __ASSUME_RECVMMSG 1
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#endif
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/* Support for /proc/self/task/$tid/comm and /proc/$pid/task/$tid/comm was
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added in 2.6.33. */
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#if __LINUX_KERNEL_VERSION >= 0x020621
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# define __ASSUME_PROC_PID_TASK_COMM 1
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#endif
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/* statfs fills in f_flags since 2.6.36. */
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#if __LINUX_KERNEL_VERSION >= 0x020624
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# define __ASSUME_STATFS_F_FLAGS 1
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#endif
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/* prlimit64 is available in 2.6.36. */
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#if __LINUX_KERNEL_VERSION >= 0x020624
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# define __ASSUME_PRLIMIT64 1
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#endif
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/* Support for sendmmsg functionality was added in 3.0. The macros
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defined correspond to those for accept4 and recvmmsg. */
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#if __LINUX_KERNEL_VERSION >= 0x030000 && defined __ASSUME_SOCKETCALL
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# define __ASSUME_SENDMMSG_SOCKETCALL 1
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#endif
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/* The sendmmsg syscall was added for i386, x86_64, PowerPC, SH and
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SPARC in 3.0. */
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#if __LINUX_KERNEL_VERSION >= 0x030000 \
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&& (defined __i386__ || defined __x86_64__ || defined __powerpc__ \
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|| defined __sh__ || defined __sparc__)
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# define __ASSUME_SENDMMSG_SYSCALL 1
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#endif
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#if defined __i386__ || defined __powerpc__ || defined __sh__ \
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|| defined __sparc__
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# define __ASSUME_SENDMMSG_SYSCALL_WITH_SOCKETCALL 1
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#endif
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#if defined __ASSUME_SENDMMSG_SOCKETCALL || defined __ASSUME_SENDMMSG_SYSCALL
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# define __ASSUME_SENDMMSG 1
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#endif
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/* getcpu is a syscall for x86-64 since 3.1. */
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#if defined __x86_64__ && __LINUX_KERNEL_VERSION >= 0x030100
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# define __ASSUME_GETCPU_SYSCALL 1
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#endif
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/* 2.6.29 removed the XFS restricted_chown sysctl, so it is pointless looking
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for it in newer kernels. */
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#define __ASSUME_XFS_RESTRICTED_CHOWN 1
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