---
 gcc/config/host-linux.c |    6 +++++-
 gcc/ggc-common.c        |    2 ++
 gcc/ggc-page.c          |    2 +-
 gcc/ggc-zone.c          |    2 +-
 gcc/ggc.h               |    7 +++++++
 gcc/opts.c              |    5 ++++-
 6 files changed, 20 insertions(+), 4 deletions(-)

Index: gcc-4.1.2.orig/gcc/config/host-linux.c
===================================================================
--- gcc-4.1.2.orig.orig/gcc/config/host-linux.c	2005-08-01 10:43:33.000000000 -0700
+++ gcc-4.1.2.orig/gcc/config/host-linux.c	2007-06-26 15:47:07.000000000 -0700
@@ -27,6 +27,10 @@
 #include "hosthooks-def.h"
 
 
+#ifndef MAP_NOZERO
+#define MAP_NOZERO      0x04000000
+#endif
+
 /* Linux has a feature called exec-shield-randomize that perturbs the
    address of non-fixed mapped segments by a (relatively) small amount.
    The feature is intended to make it harder to attack the system with
@@ -189,7 +193,7 @@
 
   /* Try to make an anonymous private mmap at the desired location.  */
   addr = mmap (base, size, PROT_READ | PROT_WRITE,
-	       MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+	       MAP_PRIVATE | MAP_ANONYMOUS | MAP_NOZERO, -1, 0);
 
   if (addr != base)
     {
Index: gcc-4.1.2.orig/gcc/ggc-common.c
===================================================================
--- gcc-4.1.2.orig.orig/gcc/ggc-common.c	2005-06-24 19:02:01.000000000 -0700
+++ gcc-4.1.2.orig/gcc/ggc-common.c	2007-06-26 15:47:07.000000000 -0700
@@ -64,6 +64,8 @@
 /* When set, ggc_collect will do collection.  */
 bool ggc_force_collect;
 
+unsigned int mmap_flags = MAP_NOZERO;
+
 /* Statistics about the allocation.  */
 static ggc_statistics *ggc_stats;
 
Index: gcc-4.1.2.orig/gcc/ggc.h
===================================================================
--- gcc-4.1.2.orig.orig/gcc/ggc.h	2005-09-06 20:50:08.000000000 -0700
+++ gcc-4.1.2.orig/gcc/ggc.h	2007-06-26 15:47:07.000000000 -0700
@@ -23,6 +23,13 @@
 #define GCC_GGC_H
 #include "statistics.h"
 
+#ifndef MAP_NOZERO
+#define MAP_NOZERO      0x04000000
+#endif
+
+extern unsigned int mmap_flags;
+
+
 /* Symbols are marked with `ggc' for `gcc gc' so as not to interfere with
    an external gc library that might be linked in.  */
 
Index: gcc-4.1.2.orig/gcc/ggc-page.c
===================================================================
--- gcc-4.1.2.orig.orig/gcc/ggc-page.c	2005-09-06 20:50:08.000000000 -0700
+++ gcc-4.1.2.orig/gcc/ggc-page.c	2007-06-26 15:47:07.000000000 -0700
@@ -662,7 +662,7 @@
 {
 #ifdef HAVE_MMAP_ANON
   char *page = mmap (pref, size, PROT_READ | PROT_WRITE,
-		     MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+		     MAP_PRIVATE | MAP_ANONYMOUS | mmap_flags, -1, 0);
 #endif
 #ifdef HAVE_MMAP_DEV_ZERO
   char *page = mmap (pref, size, PROT_READ | PROT_WRITE,
Index: gcc-4.1.2.orig/gcc/ggc-zone.c
===================================================================
--- gcc-4.1.2.orig.orig/gcc/ggc-zone.c	2005-07-25 08:14:21.000000000 -0700
+++ gcc-4.1.2.orig/gcc/ggc-zone.c	2007-06-26 15:47:07.000000000 -0700
@@ -769,7 +769,7 @@
 {
 #ifdef HAVE_MMAP_ANON
   char *page = (char *) mmap (pref, size, PROT_READ | PROT_WRITE,
-			      MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+			      MAP_PRIVATE | MAP_ANONYMOUS | mmap_flags, -1, 0);
 #endif
 #ifdef HAVE_MMAP_DEV_ZERO
   char *page = (char *) mmap (pref, size, PROT_READ | PROT_WRITE,
Index: gcc-4.1.2.orig/gcc/opts.c
===================================================================
--- gcc-4.1.2.orig.orig/gcc/opts.c	2006-05-17 11:38:58.000000000 -0700
+++ gcc-4.1.2.orig/gcc/opts.c	2007-06-26 15:47:07.000000000 -0700
@@ -278,7 +278,10 @@
   const struct cl_option *option;
 
   opt = argv[0];
-
+  if (strcmp(opt, "-mmap-zero") == 0) {
+    mmap_flags &= ~MAP_NOZERO;
+    return 1;
+  }
   opt_index = find_opt (opt + 1, lang_mask | CL_COMMON | CL_TARGET);
   if (opt_index == cl_options_count
       && (opt[1] == 'W' || opt[1] == 'f' || opt[1] == 'm')