diff -urN 2.2.16/arch/alpha/mm/fault.c s/arch/alpha/mm/fault.c
--- 2.2.16/arch/alpha/mm/fault.c	Tue Jun 13 03:48:12 2000
+++ s/arch/alpha/mm/fault.c	Sat Jun 17 03:30:41 2000
@@ -102,7 +102,7 @@
 		goto good_area;
 	if (!(vma->vm_flags & VM_GROWSDOWN))
 		goto bad_area;
-	if (expand_stack(vma, address))
+	if (expand_stack(vma, address, NULL))
 		goto bad_area;
 /*
  * Ok, we have a good vm_area for this memory access, so
diff -urN 2.2.16/arch/i386/mm/fault.c s/arch/i386/mm/fault.c
--- 2.2.16/arch/i386/mm/fault.c	Thu May  4 13:00:36 2000
+++ s/arch/i386/mm/fault.c	Sat Jun 17 03:30:41 2000
@@ -29,13 +29,13 @@
  */
 int __verify_write(const void * addr, unsigned long size)
 {
-	struct vm_area_struct * vma;
+	struct vm_area_struct * vma, * prev_vma;
 	unsigned long start = (unsigned long) addr;
 
 	if (!size)
 		return 1;
 
-	vma = find_vma(current->mm, start);
+	vma = find_vma_prev(current->mm, start, &prev_vma);
 	if (!vma)
 		goto bad_area;
 	if (vma->vm_start > start)
@@ -75,7 +75,7 @@
 check_stack:
 	if (!(vma->vm_flags & VM_GROWSDOWN))
 		goto bad_area;
-	if (expand_stack(vma, start) == 0)
+	if (expand_stack(vma, start, prev_vma) == 0)
 		goto good_area;
 
 bad_area:
@@ -112,7 +112,7 @@
 {
 	struct task_struct *tsk;
 	struct mm_struct *mm;
-	struct vm_area_struct * vma;
+	struct vm_area_struct * vma, * prev_vma;
 	unsigned long address;
 	unsigned long page;
 	unsigned long fixup;
@@ -133,7 +133,7 @@
 
 	down(&mm->mmap_sem);
 
-	vma = find_vma(mm, address);
+	vma = find_vma_prev(mm, address, &prev_vma);
 	if (!vma)
 		goto bad_area;
 	if (vma->vm_start <= address)
@@ -150,7 +150,7 @@
 		if (address + 32 < regs->esp)
 			goto bad_area;
 	}
-	if (expand_stack(vma, address))
+	if (expand_stack(vma, address, prev_vma))
 		goto bad_area;
 /*
  * Ok, we have a good vm_area for this memory access, so
diff -urN 2.2.16/arch/ppc/mm/fault.c s/arch/ppc/mm/fault.c
--- 2.2.16/arch/ppc/mm/fault.c	Thu May  4 13:00:36 2000
+++ s/arch/ppc/mm/fault.c	Sat Jun 17 03:30:41 2000
@@ -58,7 +58,7 @@
 void do_page_fault(struct pt_regs *regs, unsigned long address,
 		   unsigned long error_code)
 {
-	struct vm_area_struct * vma;
+	struct vm_area_struct * vma, * prev_vma;
 	struct mm_struct *mm = current->mm;
 	int fault;
 
@@ -89,14 +89,14 @@
 	}
 
 	down(&mm->mmap_sem);
-	vma = find_vma(mm, address);
+	vma = find_vma_prev(mm, address, &prev_vma);
 	if (!vma)
 		goto bad_area;
 	if (vma->vm_start <= address)
 		goto good_area;
 	if (!(vma->vm_flags & VM_GROWSDOWN))
 		goto bad_area;
-	if (expand_stack(vma, address))
+	if (expand_stack(vma, address, prev_vma))
 		goto bad_area;
 
 good_area:
diff -urN 2.2.16/include/linux/mm.h s/include/linux/mm.h
--- 2.2.16/include/linux/mm.h	Wed May 10 22:26:45 2000
+++ s/include/linux/mm.h	Sat Jun 17 03:30:41 2000
@@ -347,13 +347,18 @@
 
 #define GFP_DMA		__GFP_DMA
 
+extern int heap_stack_gap;
+
 /* vma is the first one with  address < vma->vm_end,
  * and even  address < vma->vm_start. Have to extend vma. */
-static inline int expand_stack(struct vm_area_struct * vma, unsigned long address)
+static inline int expand_stack(struct vm_area_struct * vma, unsigned long address,
+			       struct vm_area_struct * prev_vma)
 {
 	unsigned long grow;
 
 	address &= PAGE_MASK;
+	if (prev_vma && prev_vma->vm_end + (heap_stack_gap << PAGE_SHIFT) > address)
+		return -ENOMEM;
 	grow = vma->vm_start - address;
 	if ((vma->vm_end - address
 	    > current->rlim[RLIMIT_STACK].rlim_cur) ||
diff -urN 2.2.16/include/linux/sysctl.h s/include/linux/sysctl.h
--- 2.2.16/include/linux/sysctl.h	Tue Jun 13 03:48:15 2000
+++ s/include/linux/sysctl.h	Sat Jun 17 03:30:41 2000
@@ -121,7 +121,8 @@
 	VM_PAGECACHE=7,		/* struct: Set cache memory thresholds */
 	VM_PAGERDAEMON=8,	/* struct: Control kswapd behaviour */
 	VM_PGT_CACHE=9,		/* struct: Set page table cache parameters */
-	VM_PAGE_CLUSTER=10	/* int: set number of pages to swap together */
+	VM_PAGE_CLUSTER=10,	/* int: set number of pages to swap together */
+	VM_HEAP_STACK_GAP=11,	/* int: page gap between heap and stack */
 };
 
 
diff -urN 2.2.16/kernel/sysctl.c s/kernel/sysctl.c
--- 2.2.16/kernel/sysctl.c	Tue Jun 13 03:48:15 2000
+++ s/kernel/sysctl.c	Sat Jun 17 03:30:41 2000
@@ -252,6 +252,8 @@
 	 &pgt_cache_water, 2*sizeof(int), 0600, NULL, &proc_dointvec},
 	{VM_PAGE_CLUSTER, "page-cluster", 
 	 &page_cluster, sizeof(int), 0600, NULL, &proc_dointvec},
+	{VM_HEAP_STACK_GAP, "heap-stack-gap", 
+	 &heap_stack_gap, sizeof(int), 0644, NULL, &proc_dointvec},
 	{0}
 };
 
diff -urN 2.2.16/mm/mmap.c s/mm/mmap.c
--- 2.2.16/mm/mmap.c	Tue Jun 13 03:48:15 2000
+++ s/mm/mmap.c	Sat Jun 17 03:31:20 2000
@@ -40,6 +40,7 @@
 kmem_cache_t *vm_area_cachep;
 
 int sysctl_overcommit_memory;
+int heap_stack_gap = 1;
 
 /* Check that a process has enough memory to allocate a
  * new virtual mapping.
@@ -371,9 +372,14 @@
 
 	for (vmm = find_vma(current->mm, addr); ; vmm = vmm->vm_next) {
 		/* At this point:  (!vmm || addr < vmm->vm_end). */
+		unsigned long __heap_stack_gap = 0;
 		if (TASK_SIZE - len < addr)
 			return 0;
-		if (!vmm || addr + len <= vmm->vm_start)
+		if (!vmm)
+			return addr;
+		if (vmm->vm_flags & VM_GROWSDOWN)
+			__heap_stack_gap = heap_stack_gap << PAGE_SHIFT;
+		if (addr + len + __heap_stack_gap <= vmm->vm_start)
 			return addr;
 		addr = vmm->vm_end;
 	}