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/pause.c | 35 +++++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+) create mode 100644 sysdeps/unix/sysv/linux/pause.c (limited to 'sysdeps/unix/sysv/linux/pause.c') 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) -- cgit 1.4.1