# Check prerequisites for compiling lib/c-stack.c.
-# Copyright (C) 2002, 2003 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.
+# Copyright (C) 2002-2004, 2008-2013 Free Software Foundation, Inc.
+# This file is free software; the Free Software Foundation
+# gives unlimited permission to copy and/or distribute it,
+# with or without modifications, as long as this notice is preserved.
# Written by Paul Eggert.
+# serial 15
+
AC_DEFUN([AC_SYS_XSI_STACK_OVERFLOW_HEURISTIC],
- [# for STACK_DIRECTION
- AC_REQUIRE([AC_FUNC_ALLOCA])
- AC_CHECK_FUNCS(setrlimit)
+ [
+ AC_REQUIRE([AC_CANONICAL_HOST])
+ AC_CHECK_FUNCS_ONCE([setrlimit])
+ AC_CHECK_HEADERS_ONCE([ucontext.h])
+
+ dnl List of signals that are sent when an invalid virtual memory address
+ dnl is accessed, or when the stack overflows.
+ dnl Either { SIGSEGV } or { SIGSEGV, SIGBUS }.
+ case "$host_os" in
+ sunos4* | freebsd* | dragonfly* | openbsd* | mirbsd* | netbsd* | kfreebsd* | knetbsd*) # BSD systems
+ FAULT_YIELDS_SIGBUS=1 ;;
+ hpux*) # HP-UX
+ FAULT_YIELDS_SIGBUS=1 ;;
+ macos* | darwin*) # Mac OS X
+ FAULT_YIELDS_SIGBUS=1 ;;
+ gnu*) # Hurd
+ FAULT_YIELDS_SIGBUS=1 ;;
+ *)
+ FAULT_YIELDS_SIGBUS=0 ;;
+ esac
+ AC_DEFINE_UNQUOTED([FAULT_YIELDS_SIGBUS], [$FAULT_YIELDS_SIGBUS],
+ [Define to 1 if an invalid memory address access may yield a SIGBUS.])
AC_CACHE_CHECK([for working C stack overflow detection],
+ [ac_cv_sys_stack_overflow_works],
+ [AC_RUN_IFELSE([AC_LANG_SOURCE(
+ [[
+ #include <unistd.h>
+ #include <signal.h>
+ #if HAVE_SETRLIMIT
+ # include <sys/types.h>
+ # include <sys/time.h>
+ # include <sys/resource.h>
+ #endif
+ #ifndef SIGSTKSZ
+ # define SIGSTKSZ 16384
+ #endif
+
+ static union
+ {
+ char buffer[2 * SIGSTKSZ];
+ long double ld;
+ long u;
+ void *p;
+ } alternate_signal_stack;
+
+ static void
+ segv_handler (int signo)
+ {
+ _exit (0);
+ }
+
+ static int
+ c_stack_action ()
+ {
+ stack_t st;
+ struct sigaction act;
+ int r;
+
+ st.ss_flags = 0;
+ /* Use the midpoint to avoid Irix sigaltstack bug. */
+ st.ss_sp = alternate_signal_stack.buffer + SIGSTKSZ;
+ st.ss_size = SIGSTKSZ;
+ r = sigaltstack (&st, 0);
+ if (r != 0)
+ return 1;
+
+ sigemptyset (&act.sa_mask);
+ act.sa_flags = SA_NODEFER | SA_ONSTACK | SA_RESETHAND;
+ act.sa_handler = segv_handler;
+ #if FAULT_YIELDS_SIGBUS
+ if (sigaction (SIGBUS, &act, 0) < 0)
+ return 2;
+ #endif
+ if (sigaction (SIGSEGV, &act, 0) < 0)
+ return 3;
+ return 0;
+ }
+ static volatile int *
+ recurse_1 (volatile int n, volatile int *p)
+ {
+ if (n >= 0)
+ *recurse_1 (n + 1, p) += n;
+ return p;
+ }
+ static int
+ recurse (volatile int n)
+ {
+ int sum = 0;
+ return *recurse_1 (n, &sum);
+ }
+ int
+ main ()
+ {
+ int result;
+ #if HAVE_SETRLIMIT && defined RLIMIT_STACK
+ /* Before starting the endless recursion, try to be friendly
+ to the user's machine. On some Linux 2.2.x systems, there
+ is no stack limit for user processes at all. We don't want
+ to kill such systems. */
+ struct rlimit rl;
+ rl.rlim_cur = rl.rlim_max = 0x100000; /* 1 MB */
+ setrlimit (RLIMIT_STACK, &rl);
+ #endif
+
+ result = c_stack_action ();
+ if (result != 0)
+ return result;
+ return recurse (0);
+ }
+ ]])],
+ [ac_cv_sys_stack_overflow_works=yes],
+ [ac_cv_sys_stack_overflow_works=no],
+ [ac_cv_sys_stack_overflow_works=cross-compiling])])
+
+ if test $ac_cv_sys_stack_overflow_works = yes; then
+ AC_DEFINE([HAVE_STACK_OVERFLOW_HANDLING], [1],
+ [Define to 1 if extending the stack slightly past the limit causes
+ a SIGSEGV which can be handled on an alternate stack established
+ with sigaltstack.])
+
+ dnl The ss_sp field of a stack_t is, according to POSIX, the lowest address
+ dnl of the memory block designated as an alternate stack. But IRIX 5.3
+ dnl interprets it as the highest address!
+ AC_CACHE_CHECK([for correct stack_t interpretation],
+ [gl_cv_sigaltstack_low_base], [
+ AC_RUN_IFELSE([
+ AC_LANG_SOURCE([[
+#include <stdlib.h>
+#include <signal.h>
+#if HAVE_SYS_SIGNAL_H
+# include <sys/signal.h>
+#endif
+#ifndef SIGSTKSZ
+# define SIGSTKSZ 16384
+#endif
+volatile char *stack_lower_bound;
+volatile char *stack_upper_bound;
+static void check_stack_location (volatile char *addr)
+{
+ if (addr >= stack_lower_bound && addr <= stack_upper_bound)
+ exit (0);
+ else
+ exit (1);
+}
+static void stackoverflow_handler (int sig)
+{
+ char dummy;
+ check_stack_location (&dummy);
+}
+int main ()
+{
+ char mystack[2 * SIGSTKSZ];
+ stack_t altstack;
+ struct sigaction action;
+ /* Install the alternate stack. */
+ altstack.ss_sp = mystack + SIGSTKSZ;
+ altstack.ss_size = SIGSTKSZ;
+ stack_lower_bound = (char *) altstack.ss_sp;
+ stack_upper_bound = (char *) altstack.ss_sp + altstack.ss_size - 1;
+ altstack.ss_flags = 0; /* no SS_DISABLE */
+ if (sigaltstack (&altstack, NULL) < 0)
+ exit (2);
+ /* Install the SIGSEGV handler. */
+ sigemptyset (&action.sa_mask);
+ action.sa_handler = &stackoverflow_handler;
+ action.sa_flags = SA_ONSTACK;
+ if (sigaction (SIGSEGV, &action, (struct sigaction *) NULL) < 0)
+ exit(3);
+ /* Provoke a SIGSEGV. */
+ raise (SIGSEGV);
+ exit (4);
+}]])],
+ [gl_cv_sigaltstack_low_base=yes],
+ [gl_cv_sigaltstack_low_base=no],
+ [gl_cv_sigaltstack_low_base=cross-compiling])])
+ if test "$gl_cv_sigaltstack_low_base" = no; then
+ AC_DEFINE([SIGALTSTACK_SS_REVERSED], [1],
+ [Define if sigaltstack() interprets the stack_t.ss_sp field
+ incorrectly, as the highest address of the alternate stack range
+ rather than as the lowest address.])
+ fi
+
+ AC_CACHE_CHECK([for precise C stack overflow detection],
ac_cv_sys_xsi_stack_overflow_heuristic,
- [AC_TRY_RUN(
- [
- #include <unistd.h>
- #include <signal.h>
- #include <ucontext.h>
- #if HAVE_SETRLIMIT
- # include <sys/types.h>
- # include <sys/time.h>
- # include <sys/resource.h>
- #endif
-
- static union
- {
- char buffer[SIGSTKSZ];
- long double ld;
- long 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)
- {
- #if HAVE_SETRLIMIT && defined RLIMIT_STACK
- /* Before starting the endless recursion, try to be friendly
- to the user's machine. On some Linux 2.2.x systems, there
- is no stack limit for user processes at all. We don't want
- to kill such systems. */
- struct rlimit rl;
- rl.rlim_cur = rl.rlim_max = 0x100000; /* 1 MB */
- setrlimit (RLIMIT_STACK, &rl);
- #endif
-
- 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])])
+ [AC_RUN_IFELSE([AC_LANG_SOURCE(
+ [[
+ #include <unistd.h>
+ #include <signal.h>
+ #if HAVE_UCONTEXT_H
+ # include <ucontext.h>
+ #endif
+ #if HAVE_SETRLIMIT
+ # include <sys/types.h>
+ # include <sys/time.h>
+ # include <sys/resource.h>
+ #endif
+ #ifndef SIGSTKSZ
+ # define SIGSTKSZ 16384
+ #endif
+
+ static union
+ {
+ char buffer[2 * SIGSTKSZ];
+ long double ld;
+ long 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)
+ {
+ /* For XSI heuristics to work, we need uc_stack to describe
+ the interrupted stack (as on Solaris), and not the
+ currently executing stack (as on Linux). */
+ 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 (4);
+ }
+ _exit (5);
+ }
+
+ static int
+ c_stack_action ()
+ {
+ stack_t st;
+ struct sigaction act;
+ int r;
+
+ st.ss_flags = 0;
+ /* Use the midpoint to avoid Irix sigaltstack bug. */
+ st.ss_sp = alternate_signal_stack.buffer + SIGSTKSZ;
+ st.ss_size = SIGSTKSZ;
+ r = sigaltstack (&st, 0);
+ if (r != 0)
+ return 1;
+
+ sigemptyset (&act.sa_mask);
+ act.sa_flags = SA_NODEFER | SA_ONSTACK | SA_RESETHAND | SA_SIGINFO;
+ act.sa_sigaction = segv_handler;
+ #if FAULT_YIELDS_SIGBUS
+ if (sigaction (SIGBUS, &act, 0) < 0)
+ return 2;
+ #endif
+ if (sigaction (SIGSEGV, &act, 0) < 0)
+ return 3;
+ return 0;
+ }
+ static volatile int *
+ recurse_1 (volatile int n, volatile int *p)
+ {
+ if (n >= 0)
+ *recurse_1 (n + 1, p) += n;
+ return p;
+ }
+ static int
+ recurse (volatile int n)
+ {
+ int sum = 0;
+ return *recurse_1 (n, &sum);
+ }
+ int
+ main ()
+ {
+ int result;
+ #if HAVE_SETRLIMIT && defined RLIMIT_STACK
+ /* Before starting the endless recursion, try to be friendly
+ to the user's machine. On some Linux 2.2.x systems, there
+ is no stack limit for user processes at all. We don't want
+ to kill such systems. */
+ struct rlimit rl;
+ rl.rlim_cur = rl.rlim_max = 0x100000; /* 1 MB */
+ setrlimit (RLIMIT_STACK, &rl);
+ #endif
+
+ result = c_stack_action ();
+ if (result != 0)
+ return result;
+ return recurse (0);
+ }
+ ]])],
+ [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 $ac_cv_sys_xsi_stack_overflow_heuristic = yes; then
- AC_DEFINE(HAVE_XSI_STACK_OVERFLOW_HEURISTIC, 1,
+ AC_DEFINE([HAVE_XSI_STACK_OVERFLOW_HEURISTIC], [1],
[Define to 1 if extending the stack slightly past the limit causes
- a SIGSEGV, and an alternate stack can be established with sigaltstack,
- and the signal handler is passed a context that specifies the
- run time stack. This behavior is defined by POSIX 1003.1-2001
+ a SIGSEGV, and an alternate stack can be established with sigaltstack,
+ and the signal handler is passed a context that specifies the
+ run time stack. This behavior is defined by POSIX 1003.1-2001
with the X/Open System Interface (XSI) option
- and is a standardized way to implement a SEGV-based stack
+ and is a standardized way to implement a SEGV-based stack
overflow detection heuristic.])
- fi])
+ fi
+ fi])
-AC_DEFUN([jm_PREREQ_C_STACK],
+AC_DEFUN([gl_PREREQ_C_STACK],
[AC_REQUIRE([AC_SYS_XSI_STACK_OVERFLOW_HEURISTIC])
+ AC_REQUIRE([gl_LIBSIGSEGV])
# for STACK_DIRECTION
AC_REQUIRE([AC_FUNC_ALLOCA])
- AC_CHECK_FUNCS(getcontext sigaltstack)
- AC_CHECK_DECLS([getcontext], , , [#include <ucontext.h>])
- AC_CHECK_DECLS([sigaltstack], , , [#include <signal.h>])
+ AC_CHECK_FUNCS_ONCE([sigaltstack])
+ AC_CHECK_DECLS([sigaltstack], , , [[#include <signal.h>]])
+
+ AC_CHECK_HEADERS_ONCE([unistd.h ucontext.h])
- AC_CHECK_HEADERS_ONCE(sys/time.h unistd.h)
- AC_CHECK_HEADERS(sys/resource.h ucontext.h)
+ AC_CHECK_TYPES([stack_t], , , [#include <signal.h>])
- AC_CHECK_TYPES([stack_t], , , [#include <signal.h>])])
+ dnl c-stack does not need -lsigsegv if the system has XSI heuristics.
+ if test "$gl_cv_lib_sigsegv" = yes \
+ && test $"ac_cv_sys_xsi_stack_overflow_heuristic" != yes ; then
+ AC_SUBST([LIBCSTACK], [$LIBSIGSEGV])
+ AC_SUBST([LTLIBCSTACK], [$LTLIBSIGSEGV])
+ fi
+])
AC_DEFUN([gl_C_STACK],
[
dnl Prerequisites of lib/c-stack.c.
- jm_PREREQ_C_STACK
+ gl_PREREQ_C_STACK
])
projects / gnulib.git / blobdiff