| /* Emulate sigstack function using sigaltstack. |
| Copyright (C) 1998-2014 Free Software Foundation, Inc. |
| This file is part of the GNU C Library. |
| Contributed by Ulrich Drepper <drepper@cygnus.com>, 1998. |
| |
| 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 |
| <http://www.gnu.org/licenses/>. */ |
| |
| #include <signal.h> |
| #include <stddef.h> |
| #include <sys/syscall.h> |
| |
| |
| #ifdef __NR_sigaltstack |
| int |
| sigstack (ss, oss) |
| struct sigstack *ss; |
| struct sigstack *oss; |
| { |
| stack_t sas; |
| stack_t *sasp = NULL; |
| stack_t osas; |
| stack_t *osasp = oss == NULL ? NULL : &osas; |
| int result; |
| |
| if (ss != NULL) |
| { |
| /* We have to convert the information. */ |
| sas.ss_sp = ss->ss_sp; |
| sas.ss_flags = ss->ss_onstack ? SS_ONSTACK : 0; |
| |
| /* For the size of the stack we have no value we can pass to the |
| kernel. This is why this function should not be used. We simply |
| assume that all the memory down to address zero (in case the stack |
| grows down) is available. */ |
| sas.ss_size = ss->ss_sp - NULL; |
| |
| sasp = &sas; |
| } |
| |
| /* Call the kernel. */ |
| result = __sigaltstack (sasp, osasp); |
| |
| /* Convert the result, if wanted and possible. */ |
| if (result == 0 && oss != NULL) |
| { |
| oss->ss_sp = osas.ss_sp; |
| oss->ss_onstack = (osas.ss_flags & SS_ONSTACK) != 0; |
| } |
| |
| return result; |
| } |
| |
| link_warning (sigstack, "the `sigstack' function is dangerous. `sigaltstack' should be used instead.") |
| #else |
| # include <signal/sigstack.c> |
| #endif |