From 88499a87cef0a70f381524b9c4951b53bc5184e3 Mon Sep 17 00:00:00 2001 From: Adhemerval Zanella Date: Mon, 21 Nov 2016 17:26:35 -0200 Subject: posix: Consolidate Linux pause syscall This patch consolidates the pause Linux implementation on sysdeps/unix/sysv/linux/pause.c. If defined the pause syscall (__NR_pause) will be used, other ppoll with 0 arguments will be used instead. It has the small advantage of generic pause implementation with uses rt_sigprocmask plus rt_sigsuspend because it requires only one syscall and the pause is done atomically regarding signal handling (for instance, pause may not be interrupted if the signal arrives between the rt_sigprocmask and rt_sigsuspend syscall). Checked on i686-linux-gnu, x86_64-linux-gnu, x86_64-linux-gnux32, arch64-linux-gnu, arm-linux-gnueabihf, powerpc64le-linux-gnu, sparc64-linux-gnu, and sparcv9-linux-gnu. * sysdeps/unix/sysv/linux/generic/pause.c: Remove file. * sysdeps/unix/sysv/linux/sparc/sparc64/pause.c: Likewise. * sysdeps/unix/sysv/linux/sparc/kernel-features.h [__arch64__] (__NR_pause): Undefine. * sysdeps/unix/sysv/linux/pause.c: New file. * sysdeps/unix/sysv/linux/syscalls.list: Remove pause from auto-generation list. --- sysdeps/unix/sysv/linux/generic/pause.c | 39 ------------------------- sysdeps/unix/sysv/linux/pause.c | 35 ++++++++++++++++++++++ sysdeps/unix/sysv/linux/sparc/kernel-features.h | 4 +++ sysdeps/unix/sysv/linux/sparc/sparc64/Makefile | 1 - sysdeps/unix/sysv/linux/sparc/sparc64/pause.c | 9 ------ sysdeps/unix/sysv/linux/syscalls.list | 1 - 6 files changed, 39 insertions(+), 50 deletions(-) delete mode 100644 sysdeps/unix/sysv/linux/generic/pause.c create mode 100644 sysdeps/unix/sysv/linux/pause.c delete mode 100644 sysdeps/unix/sysv/linux/sparc/sparc64/pause.c (limited to 'sysdeps/unix') diff --git a/sysdeps/unix/sysv/linux/generic/pause.c b/sysdeps/unix/sysv/linux/generic/pause.c deleted file mode 100644 index a8b3e33a6c..0000000000 --- a/sysdeps/unix/sysv/linux/generic/pause.c +++ /dev/null @@ -1,39 +0,0 @@ -/* Copyright (C) 2011-2017 Free Software Foundation, Inc. - This file is part of the GNU C Library. - Contributed by Chris Metcalf , 2011. - - 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 - . */ - -#include -#include -#include - -/* Suspend the process until a signal arrives. - This always returns -1 and sets errno to EINTR. */ - -int -__libc_pause (void) -{ - sigset_t set; - - int rc = - SYSCALL_CANCEL (rt_sigprocmask, SIG_BLOCK, NULL, &set, _NSIG / 8); - if (rc == 0) - rc = SYSCALL_CANCEL (rt_sigsuspend, &set, _NSIG / 8); - - return rc; -} - -weak_alias (__libc_pause, pause) diff --git a/sysdeps/unix/sysv/linux/pause.c b/sysdeps/unix/sysv/linux/pause.c new file mode 100644 index 0000000000..4ccce9ebd8 --- /dev/null +++ b/sysdeps/unix/sysv/linux/pause.c @@ -0,0 +1,35 @@ +/* Linux pause syscall implementation. + Copyright (C) 2017 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 + . */ + +#include +#include +#include + +/* Suspend the process until a signal arrives. + This always returns -1 and sets errno to EINTR. */ + +int +__libc_pause (void) +{ +#ifdef __NR_pause + return SYSCALL_CANCEL (pause); +#else + return SYSCALL_CANCEL (ppoll, NULL, 0, NULL, NULL); +#endif +} +weak_alias (__libc_pause, pause) diff --git a/sysdeps/unix/sysv/linux/sparc/kernel-features.h b/sysdeps/unix/sysv/linux/sparc/kernel-features.h index 72065a0248..3fafab359c 100644 --- a/sysdeps/unix/sysv/linux/sparc/kernel-features.h +++ b/sysdeps/unix/sysv/linux/sparc/kernel-features.h @@ -32,6 +32,10 @@ # undef __ASSUME_ACCEPT_SYSCALL # undef __ASSUME_CONNECT_SYSCALL # undef __ASSUME_RECVFROM_SYSCALL +#else +/* sparc64 defines __NR_pause, however it is not supported (ENOSYS). + Undefine so pause.c can use a correct alternative. */ +# undef __NR_pause #endif /* sparc only supports ipc syscall. */ diff --git a/sysdeps/unix/sysv/linux/sparc/sparc64/Makefile b/sysdeps/unix/sysv/linux/sparc/sparc64/Makefile index 7ea433f21f..3a7f4aa84a 100644 --- a/sysdeps/unix/sysv/linux/sparc/sparc64/Makefile +++ b/sysdeps/unix/sysv/linux/sparc/sparc64/Makefile @@ -9,6 +9,5 @@ sysdep_routines += __start_context endif ifeq ($(subdir),nptl) -CFLAGS-pause.c += -fexceptions CFLAGS-sigsuspend.c += -fexceptions endif diff --git a/sysdeps/unix/sysv/linux/sparc/sparc64/pause.c b/sysdeps/unix/sysv/linux/sparc/sparc64/pause.c deleted file mode 100644 index e399e7c7eb..0000000000 --- a/sysdeps/unix/sysv/linux/sparc/sparc64/pause.c +++ /dev/null @@ -1,9 +0,0 @@ -#include -#include -#include -#include - -#define __sigprocmask(how, set, oset) \ - INLINE_SYSCALL (rt_sigprocmask, 4, how, set, oset, _NSIG / 8) - -#include diff --git a/sysdeps/unix/sysv/linux/syscalls.list b/sysdeps/unix/sysv/linux/syscalls.list index f4abf3e6c8..eab30dda06 100644 --- a/sysdeps/unix/sysv/linux/syscalls.list +++ b/sysdeps/unix/sysv/linux/syscalls.list @@ -44,7 +44,6 @@ munlock - munlock i:ai munlock munlockall - munlockall i: munlockall nanosleep - nanosleep Ci:pp __nanosleep nanosleep nfsservctl EXTRA nfsservctl i:ipp nfsservctl -pause - pause Ci: __libc_pause pause pipe - pipe i:f __pipe pipe pipe2 - pipe2 i:fi __pipe2 pipe2 pivot_root EXTRA pivot_root i:ss pivot_root -- cgit v1.2.3