diff -urNp --exclude CVS --exclude BitKeeper --exclude {arch} --exclude .arch-ids x-ref/arch/s390x/kernel/binfmt_elf32.c x/arch/s390x/kernel/binfmt_elf32.c
--- x-ref/arch/s390x/kernel/binfmt_elf32.c	2003-11-28 23:12:33.000000000 +0100
+++ x/arch/s390x/kernel/binfmt_elf32.c	2004-05-31 16:02:45.529156584 +0200
@@ -198,7 +198,7 @@ elf_map32 (struct file *filep, unsigned 
 	unsigned long map_addr;
 
 	if(!addr)
-		addr = 0x40000000;
+		addr = current->map_base;
 
 	down_write(&current->mm->mmap_sem);
 	map_addr = do_mmap(filep, ELF_PAGESTART(addr),
diff -urNp --exclude CVS --exclude BitKeeper --exclude {arch} --exclude .arch-ids x-ref/fs/proc/base.c x/fs/proc/base.c
--- x-ref/fs/proc/base.c	2003-11-28 23:12:44.000000000 +0100
+++ x/fs/proc/base.c	2004-05-31 16:02:45.521157800 +0200
@@ -499,6 +499,58 @@ static struct file_operations proc_mem_o
 	open:		mem_open,
 };
 
+#ifdef __HAS_ARCH_PROC_MAPPED_BASE
+static ssize_t mapbase_read(struct file * file, char * buf,
+			size_t count, loff_t *ppos)
+{
+	struct task_struct *task = file->f_dentry->d_inode->u.proc_i.task;
+	char buffer[64];
+	size_t len;
+	
+	sprintf(buffer, "%li", task->map_base);
+	len=strlen(buffer)+1;			
+	*ppos += len;
+	if (copy_to_user(buf, buffer, len)) 
+		len = -EFAULT;
+	
+	return (len<*ppos)?0:len;
+}
+
+static ssize_t mapbase_write(struct file * file, const char * buf,
+			 size_t count, loff_t *ppos)
+{
+	struct task_struct *task = file->f_dentry->d_inode->u.proc_i.task;
+	char buffer[64];
+	int len;
+	unsigned long newbase;
+	if (!capable(CAP_SYS_ADMIN)) return -EPERM;
+	memset(buffer, 0, 64);
+	len = count;
+	if (len>63)
+		len = 63;
+	if (copy_from_user(buffer, buf, len)) 
+		return -EFAULT;
+	
+	for (len = 0; len < 64; len++)
+		if (!buffer[len])
+			break;
+	if (len>60)
+		return -EFAULT;
+	
+	newbase = simple_strtoul(buffer, NULL, 0);
+
+	if (newbase > 0)
+		task->map_base = newbase;
+	
+	return len;
+}
+
+static struct file_operations proc_mapbase_operations = {
+	read:		mapbase_read,
+	write:		mapbase_write,
+};
+#endif /* __HAS_ARCH_PROC_MAPPED_BASE */
+
 static struct inode_operations proc_mem_inode_operations = {
 	permission:	proc_permission,
 };
@@ -599,6 +651,7 @@ enum pid_directory_inos {
 	PROC_PID_MAPS,
 	PROC_PID_CPU,
 	PROC_PID_MOUNTS,
+	PROC_PID_MAPBASE,
 	PROC_PID_FD_DIR = 0x8000,	/* 0x8000-0xffff */
 };
 
@@ -619,6 +672,9 @@ static struct pid_entry base_stuff[] = {
   E(PROC_PID_ROOT,	"root",		S_IFLNK|S_IRWXUGO),
   E(PROC_PID_EXE,	"exe",		S_IFLNK|S_IRWXUGO),
   E(PROC_PID_MOUNTS,	"mounts",	S_IFREG|S_IRUGO),
+#ifdef __HAS_ARCH_PROC_MAPPED_BASE
+  E(PROC_PID_MAPBASE,	"mapped_base",	S_IFREG|S_IRUSR|S_IWUSR),
+#endif
   {0,0,NULL,0}
 };
 #undef E
@@ -971,6 +1027,11 @@ static struct dentry *proc_base_lookup(s
 			inode->i_fop = &proc_info_file_operations;
 			inode->u.proc_i.op.proc_read = proc_pid_statm;
 			break;
+#ifdef __HAS_ARCH_PROC_MAPPED_BASE
+		case PROC_PID_MAPBASE:
+			inode->i_fop = &proc_mapbase_operations;
+			break;
+#endif
 		case PROC_PID_MAPS:
 			inode->i_fop = &proc_maps_operations;
 			break;
diff -urNp --exclude CVS --exclude BitKeeper --exclude {arch} --exclude .arch-ids x-ref/include/asm-i386/processor.h x/include/asm-i386/processor.h
--- x-ref/include/asm-i386/processor.h	2004-05-31 16:02:39.799027696 +0200
+++ x/include/asm-i386/processor.h	2004-05-31 16:02:45.523157496 +0200
@@ -265,10 +265,12 @@ extern unsigned int mca_pentium_flag;
 /* This decides where the kernel will search for a free chunk of vm
  * space during mmap's.
  */
+#define TASK_UNMAPPED_BASE	(current->map_base)
+
 #ifndef CONFIG_05GB
-#define TASK_UNMAPPED_BASE	(TASK_SIZE / 3)
+#define __TASK_UNMAPPED_BASE	(TASK_SIZE / 3)
 #else
-#define TASK_UNMAPPED_BASE	(TASK_SIZE / 16)
+#define __TASK_UNMAPPED_BASE	(TASK_SIZE / 16)
 #endif
 
 /*
diff -urNp --exclude CVS --exclude BitKeeper --exclude {arch} --exclude .arch-ids x-ref/include/asm-s390/processor.h x/include/asm-s390/processor.h
--- x-ref/include/asm-s390/processor.h	2003-06-13 22:07:41.000000000 +0200
+++ x/include/asm-s390/processor.h	2004-05-31 16:02:45.523157496 +0200
@@ -60,7 +60,8 @@ extern struct task_struct *last_task_use
 /* This decides where the kernel will search for a free chunk of vm
  * space during mmap's.
  */
-#define TASK_UNMAPPED_BASE      (TASK_SIZE / 2)
+#define __TASK_UNMAPPED_BASE      (TASK_SIZE / 2)
+#define TASK_UNMAPPED_BASE	(current->map_base)
 
 #define THREAD_SIZE (2*PAGE_SIZE)
 
diff -urNp --exclude CVS --exclude BitKeeper --exclude {arch} --exclude .arch-ids x-ref/include/asm-s390x/processor.h x/include/asm-s390x/processor.h
--- x-ref/include/asm-s390x/processor.h	2003-06-13 22:07:42.000000000 +0200
+++ x/include/asm-s390x/processor.h	2004-05-31 16:02:45.524157344 +0200
@@ -62,12 +62,13 @@ extern struct task_struct *last_task_use
  */
 #define TASK_SIZE       (0x20000000000UL)
 #define TASK31_SIZE     (0x80000000UL)
+#define __TASK_UNMAPPED_BASE (TASK31_SIZE/2)
 
 /* This decides where the kernel will search for a free chunk of vm
  * space during mmap's.
  */
 #define TASK_UNMAPPED_BASE      ((current->thread.flags & S390_FLAG_31BIT) ? \
-	(TASK31_SIZE / 2) : (TASK_SIZE / 2))
+	(current->map_base) : (TASK_SIZE / 2))
 
 #define THREAD_SIZE (4*PAGE_SIZE)
 
diff -urNp --exclude CVS --exclude BitKeeper --exclude {arch} --exclude .arch-ids x-ref/include/asm-um/processor-generic.h x/include/asm-um/processor-generic.h
--- x-ref/include/asm-um/processor-generic.h	2004-05-31 16:02:41.449776744 +0200
+++ x/include/asm-um/processor-generic.h	2004-05-31 16:02:45.524157344 +0200
@@ -139,7 +139,8 @@ extern unsigned long task_size;
 /* This decides where the kernel will search for a free chunk of vm
  * space during mmap's.
  */
-#define TASK_UNMAPPED_BASE	(0x40000000)
+#define __TASK_UNMAPPED_BASE	(0x40000000)
+#define TASK_UNMAPPED_BASE	(current->map_base)
 
 extern void start_thread(struct pt_regs *regs, unsigned long entry, 
 			 unsigned long stack);
diff -urNp --exclude CVS --exclude BitKeeper --exclude {arch} --exclude .arch-ids x-ref/include/asm-x86_64/processor.h x/include/asm-x86_64/processor.h
--- x-ref/include/asm-x86_64/processor.h	2003-11-28 23:12:46.000000000 +0100
+++ x/include/asm-x86_64/processor.h	2004-05-31 16:03:52.260011952 +0200
@@ -250,11 +250,12 @@ static inline void clear_in_cr4 (unsigne
  * space during mmap's.
  */
 
+#define __TASK_UNMAPPED_BASE TASK_UNMAPPED_32
 #define IA32_PAGE_OFFSET ((current->personality & ADDR_LIMIT_3GB) ? 0xc0000000 : 0xFFFFe000)
 #define TASK_UNMAPPED_32 (IA32_PAGE_OFFSET / 3) 
 #define TASK_UNMAPPED_64 (TASK_SIZE/3) 
 #define TASK_UNMAPPED_BASE	\
-	((current->thread.flags & THREAD_IA32) ? TASK_UNMAPPED_32 : TASK_UNMAPPED_64)  
+	((current->thread.flags & THREAD_IA32) ? (current->map_base) : TASK_UNMAPPED_64)  
 
 /*
  * Size of io_bitmap in longwords: 32 is ports 0-0x3ff.
diff -urNp --exclude CVS --exclude BitKeeper --exclude {arch} --exclude .arch-ids x-ref/include/linux/sched.h x/include/linux/sched.h
--- x-ref/include/linux/sched.h	2004-05-31 16:02:42.480620032 +0200
+++ x/include/linux/sched.h	2004-05-31 16:02:45.528156736 +0200
@@ -436,6 +436,9 @@ struct task_struct {
 
 /* journalling filesystem info */
 	void *journal_info;
+
+/* TASK_UNMAPPED_BASE value */
+	unsigned long map_base;
 };
 
 /*
@@ -488,6 +491,12 @@ extern void yield(void);
  */
 extern struct exec_domain	default_exec_domain;
 
+#ifndef __TASK_UNMAPPED_BASE
+#define __TASK_UNMAPPED_BASE 0UL
+#else
+#define __HAS_ARCH_PROC_MAPPED_BASE
+#endif
+
 /*
  *  INIT_TASK is used to set up the first task table, touch at
  * your own risk!. Base=0, limit=0x1fffff (=2MB)
@@ -534,6 +543,7 @@ extern struct exec_domain	default_exec_d
     alloc_lock:		SPIN_LOCK_UNLOCKED,				\
     switch_lock:        SPIN_LOCK_UNLOCKED,                             \
     journal_info:	NULL,						\
+    map_base:		__TASK_UNMAPPED_BASE,				\
 }