82 lines
2.5 KiB
C
82 lines
2.5 KiB
C
/* sigaltstack wrappers.
|
|
Copyright (C) 2019-2022 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
|
|
<https://www.gnu.org/licenses/>. */
|
|
|
|
#include <support/xsignal.h>
|
|
#include <support/support.h>
|
|
#include <support/xunistd.h>
|
|
#include <support/check.h>
|
|
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
#include <sys/mman.h>
|
|
#include <sys/param.h> /* roundup, MAX */
|
|
|
|
#ifndef MAP_NORESERVE
|
|
# define MAP_NORESERVE 0
|
|
#endif
|
|
#ifndef MAP_STACK
|
|
# define MAP_STACK 0
|
|
#endif
|
|
|
|
/* The "cookie" returned by xalloc_sigstack points to one of these
|
|
structures. */
|
|
struct sigstack_desc
|
|
{
|
|
struct support_stack stack;
|
|
stack_t alt_stack; /* The address and size of the stack itself. */
|
|
stack_t old_stack; /* The previous signal stack. */
|
|
};
|
|
|
|
void *
|
|
xalloc_sigstack (size_t size)
|
|
{
|
|
struct sigstack_desc *desc = xmalloc (sizeof (struct sigstack_desc));
|
|
desc->stack = support_stack_alloc (size);
|
|
desc->alt_stack.ss_sp = desc->stack.stack;
|
|
desc->alt_stack.ss_flags = 0;
|
|
desc->alt_stack.ss_size = desc->stack.size;
|
|
|
|
if (sigaltstack (&desc->alt_stack, &desc->old_stack))
|
|
FAIL_EXIT1 ("sigaltstack (new stack: sp=%p, size=%zu, flags=%u): %m\n",
|
|
desc->alt_stack.ss_sp, desc->alt_stack.ss_size,
|
|
desc->alt_stack.ss_flags);
|
|
|
|
return desc;
|
|
}
|
|
|
|
void
|
|
xfree_sigstack (void *stack)
|
|
{
|
|
struct sigstack_desc *desc = stack;
|
|
|
|
if (sigaltstack (&desc->old_stack, 0))
|
|
FAIL_EXIT1 ("sigaltstack (restore old stack: sp=%p, size=%zu, flags=%u): "
|
|
"%m\n", desc->old_stack.ss_sp, desc->old_stack.ss_size,
|
|
desc->old_stack.ss_flags);
|
|
support_stack_free (&desc->stack);
|
|
free (desc);
|
|
}
|
|
|
|
void
|
|
xget_sigstack_location (const void *stack, unsigned char **addrp, size_t *sizep)
|
|
{
|
|
const struct sigstack_desc *desc = stack;
|
|
*addrp = desc->alt_stack.ss_sp;
|
|
*sizep = desc->alt_stack.ss_size;
|
|
}
|