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* configure.in (HAVE_RANDOM_HEAPSTART): Renamed HAVE_EXECSHIELD.

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Run test to see if heap start address is random.
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Jan Djärv 2004-10-05 20:24:19 +00:00
parent 0c8b5b65f1
commit 4494a266b4
3 changed files with 530 additions and 292 deletions
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ChangeLog
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@ -1,3 +1,8 @@
2004-10-05 Jan D. <jhd@ostrich.localdomain>
* configure.in (HAVE_RANDOM_HEAPSTART): Renamed HAVE_EXECSHIELD.
Run test to see if heap start address is random.
2004-09-29 Miles Bader <miles@gnu.org>
* configure.in (HAVE_EXECSHIELD): Test correct env variable to see

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67
configure.in
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@ -1286,25 +1286,6 @@ AC_LINK_IFELSE([main(){return 0;}],
dnl checks for Unix variants
AC_AIX
dnl check if exec-shield is present.
AC_CHECK_FILE(/proc/sys/kernel/exec-shield, emacs_cv_execshield=1,
emacs_cv_execshield=0)
if test "$emacs_cv_execshield" = 1; then
AC_PATH_PROG(SETARCH, setarch, no)
AC_SUBST(SETARCH)
if test "$SETARCH" != no && test "$machine" = "intel386"; then
AC_DEFINE(HAVE_EXECSHIELD, 1,
[Define to 1 if this OS has exec shield and we can handle it.])
else
case "`cat /proc/sys/kernel/exec-shield`" in
0) ;;
*)
AC_MSG_ERROR([Exec-shield is turned on.
Emacs can not dump itself if exec-shield is turned on.
See `etc/PROBLEMS' for further information.])
esac
fi
fi
#### Extract some information from the operating system and machine files.
@ -1591,6 +1572,54 @@ AH_TEMPLATE(POINTER_TYPE,
[Define as `void' if your compiler accepts `void *'; otherwise
define as `char'.])dnl
dnl Test if heap start address is randomized (exec-shield does this).
dnl The test program requires unistd.h and stdlib.h. They are present
dnl on the systems that currently have exec-shield.
AC_MSG_CHECKING(whether heap start address is randomized)
if test x"$ac_cv_header_unistd_h" != x && test x"$ac_cv_header_stdlib_h" != x
then
AC_TRY_RUN([#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
int main (int argc, char *argv[])
{
unsigned long old_sbrk = 0;
unsigned long this_sbrk = (unsigned long) sbrk(0);
int nr = 1;
if (argc != 1) {
old_sbrk = strtoul (argv[1], 0, 0);
nr = atoi (argv[2])+1;
}
if (argc == 1 || (old_sbrk == this_sbrk && nr < 3))
{
char buf1[32], buf2[32];
sprintf (buf1, "%lu", this_sbrk);
sprintf (buf2, "%d", nr);
execl (argv[0], argv[0], buf1, buf2, 0);
exit (-1);
}
exit (this_sbrk == old_sbrk);
}], emacs_cv_execshield=yes, emacs_cv_execshield=no,
emacs_cv_execshield='assuming no')
else
emacs_cv_execshield='assuming no'
fi
AC_MSG_RESULT($emacs_cv_execshield)
if test "$emacs_cv_execshield" = yes; then
AC_PATH_PROG(SETARCH, setarch, no)
AC_SUBST(SETARCH)
if test "$SETARCH" != no && test "$machine" = "intel386"; then
AC_DEFINE(HAVE_RANDOM_HEAPSTART, 1,
[Define to 1 if this OS randomizes the start address of the heap.])
else
AC_MSG_ERROR([Heap start address is randomized and no workaround is known.
Probably exec-shield is turned on. Emacs can not dump itself if this is the
case. Read about exec-shield in `etc/PROBLEMS' for further information.])
fi
fi
dnl This could be used for targets which can have both byte sexes.
dnl We could presumably replace the hardwired WORDS_BIG_ENDIAN generally.
dnl AC_C_BIGENDIAN