132 lines
3.6 KiB
Plaintext
132 lines
3.6 KiB
Plaintext
# Check prerequisites for compiling lib/c-stack.c.
|
|
|
|
# Copyright (C) 2002 Free Software Foundation, Inc.
|
|
|
|
# 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., 59 Temple Place - Suite 330, Boston, MA
|
|
# 02111-1307, USA.
|
|
|
|
AC_DEFUN([AC_SYS_XSI_STACK_OVERFLOW_HEURISTIC],
|
|
[# for STACK_DIRECTION
|
|
AC_REQUIRE([AC_FUNC_ALLOCA])
|
|
|
|
AC_CACHE_CHECK([for working C stack overflow detection],
|
|
ac_cv_sys_xsi_stack_overflow_heuristic,
|
|
[AC_TRY_RUN(
|
|
[
|
|
#include <signal.h>
|
|
#include <ucontext.h>
|
|
|
|
static union
|
|
{
|
|
char buffer[SIGSTKSZ];
|
|
long double ld;
|
|
uintmax_t u;
|
|
void *p;
|
|
} alternate_signal_stack;
|
|
|
|
#if STACK_DIRECTION
|
|
# define find_stack_direction(ptr) STACK_DIRECTION
|
|
#else
|
|
static int
|
|
find_stack_direction (char const *addr)
|
|
{
|
|
char dummy;
|
|
return (! addr ? find_stack_direction (&dummy)
|
|
: addr < &dummy ? 1 : -1);
|
|
}
|
|
#endif
|
|
|
|
static void
|
|
segv_handler (int signo, siginfo_t *info, void *context)
|
|
{
|
|
if (0 < info->si_code)
|
|
{
|
|
ucontext_t const *user_context = context;
|
|
char const *stack_min = user_context->uc_stack.ss_sp;
|
|
size_t stack_size = user_context->uc_stack.ss_size;
|
|
char const *faulting_address = info->si_addr;
|
|
size_t s = faulting_address - stack_min;
|
|
size_t page_size = sysconf (_SC_PAGESIZE);
|
|
if (find_stack_direction (0) < 0)
|
|
s += page_size;
|
|
if (s < stack_size + page_size)
|
|
_exit (0);
|
|
}
|
|
|
|
_exit (1);
|
|
}
|
|
|
|
static int
|
|
c_stack_action (void)
|
|
{
|
|
stack_t st;
|
|
struct sigaction act;
|
|
int r;
|
|
|
|
st.ss_flags = 0;
|
|
st.ss_sp = alternate_signal_stack.buffer;
|
|
st.ss_size = sizeof alternate_signal_stack.buffer;
|
|
r = sigaltstack (&st, 0);
|
|
if (r != 0)
|
|
return r;
|
|
|
|
sigemptyset (&act.sa_mask);
|
|
act.sa_flags = SA_NODEFER | SA_ONSTACK | SA_RESETHAND | SA_SIGINFO;
|
|
act.sa_sigaction = segv_handler;
|
|
return sigaction (SIGSEGV, &act, 0);
|
|
}
|
|
|
|
static int
|
|
recurse (char *p)
|
|
{
|
|
char array[500];
|
|
array[0] = 1;
|
|
return *p + recurse (array);
|
|
}
|
|
|
|
int
|
|
main (void)
|
|
{
|
|
c_stack_action ();
|
|
return recurse ("\1");
|
|
}
|
|
],
|
|
[ac_cv_sys_xsi_stack_overflow_heuristic=yes],
|
|
[ac_cv_sys_xsi_stack_overflow_heuristic=no],
|
|
[ac_cv_sys_xsi_stack_overflow_heuristic=cross-compiling])])
|
|
|
|
if test $ac_cv_sys_xsi_stack_overflow_heuristic = yes; then
|
|
AC_DEFINE(HAVE_XSI_STACK_OVERFLOW_HEURISTIC, 1,
|
|
[Define to 1 if extending the stack slightly past the limit causes
|
|
a SIGSEGV, and an alternate stack can be established with sigaltstack,
|
|
and the signal handler is passed a context that specifies the
|
|
run time stack. This behavior is defined by POSIX 1003.1-2001
|
|
with the X/Open System Interface (XSI) option
|
|
and is a standardized way to implement a SEGV-based stack
|
|
overflow detection heuristic.])
|
|
fi])
|
|
|
|
|
|
AC_DEFUN([jm_PREREQ_C_STACK],
|
|
[AC_REQUIRE([jm_AC_TYPE_UINTMAX_T])
|
|
AC_REQUIRE([AC_SYS_XSI_STACK_OVERFLOW_HEURISTIC])
|
|
|
|
# for STACK_DIRECTION
|
|
AC_REQUIRE([AC_FUNC_ALLOCA])
|
|
|
|
AC_CHECK_HEADERS(unistd.h)
|
|
|
|
AC_CHECK_TYPES([siginfo_t, stack_t], , , [#include <signal.h>])])
|