70 lines
2.1 KiB
C
70 lines
2.1 KiB
C
/* Emulate sigstack function using sigaltstack.
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Copyright (C) 1998 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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Contributed by Ulrich Drepper <drepper@cygnus.com>, 1998.
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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 Library General Public License as
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published by the Free Software Foundation; either version 2 of the
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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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Library General Public License for more details.
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You should have received a copy of the GNU Library General Public
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License along with the GNU C Library; see the file COPYING.LIB. If not,
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write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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Boston, MA 02111-1307, USA. */
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#include <signal.h>
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#include <stddef.h>
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#include <sys/syscall.h>
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#ifdef __NR_sigaltstack
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int
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sigstack (ss, oss)
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const struct sigstack *ss;
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struct sigstack *oss;
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{
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stack_t sas;
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stack_t *sasp = NULL;
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stack_t osas;
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stack_t *osasp = oss == NULL ? NULL : &osas;
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int result;
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if (ss != NULL)
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{
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/* We have to convert the information. */
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sas.ss_sp = ss->ss_sp;
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sas.ss_flags = ss->ss_onstack ? SS_ONSTACK : 0;
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/* For the size of the stack we have no value we can pass to the
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kernel. This is why this function should not be used. We simply
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assume that all the memory down to address zero (in case the stack
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grows down) is available. */
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sas.ss_size = ss->ss_sp - NULL;
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sasp = &sas;
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}
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/* Call the kernel. */
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result = __sigaltstack (sasp, osasp);
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/* Convert the result, if wanted and possible. */
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if (result == 0 && oss != NULL)
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{
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oss->ss_sp = osas.ss_sp;
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oss->ss_onstack = (osas.ss_flags & SS_ONSTACK) != 0;
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}
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return result;
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}
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link_warning (sigstack, "the `sigstack' function is dangerous. `sigaltstack' should be used instead.")
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#else
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# include <sysdeps/generic/sigstack.c>
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#endif
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