From 3ba50a15ebd976f7a88393e2e45dc14b6478b9a9 Mon Sep 17 00:00:00 2001 From: "Arnold D. Robbins" Date: Fri, 16 Jul 2010 14:52:31 +0300 Subject: Move to gawk-3.1.7. --- libsigsegv/src/leave-setcontext.c | 38 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 38 insertions(+) create mode 100644 libsigsegv/src/leave-setcontext.c (limited to 'libsigsegv/src/leave-setcontext.c') diff --git a/libsigsegv/src/leave-setcontext.c b/libsigsegv/src/leave-setcontext.c new file mode 100644 index 00000000..e383cf96 --- /dev/null +++ b/libsigsegv/src/leave-setcontext.c @@ -0,0 +1,38 @@ +/* Leaving a signal handler executing on the alternate stack. + Copyright (C) 2002 Bruno Haible + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2, or (at your option) + any later version. + + This program 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 General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software Foundation, + Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ + +#include +#include + +void +sigsegv_reset_onstack_flag (void) +{ + ucontext_t uc; + + if (getcontext (&uc) >= 0) + /* getcontext returns twice. We are interested in the returned context + only the first time, i.e. when the SS_ONSTACK bit is set. */ + if (uc.uc_stack.ss_flags & SS_ONSTACK) + { + uc.uc_stack.ss_flags &= ~SS_ONSTACK; + /* Note that setcontext() does not refill uc. Therefore if + setcontext() keeps SS_ONSTACK set in the kernel, either + setcontext() will return -1 or getcontext() will return a + second time, with the SS_ONSTACK bit being cleared. */ + setcontext (&uc); + } +} -- cgit v1.2.3