From e2138a2a4d692e07b68120def684697144681f28 Mon Sep 17 00:00:00 2001
From: Dale Rahn <drahn@cvs.openbsd.org>
Date: Thu, 17 Apr 2003 03:50:55 +0000
Subject: changes to support mquery with 1Gsep on i386. avoid heap on mappings.

---
 sys/uvm/uvm_map.c  | 11 ++++++++++-
 sys/uvm/uvm_mmap.c | 15 ++++++++++++++-
 2 files changed, 24 insertions(+), 2 deletions(-)

(limited to 'sys/uvm')

diff --git a/sys/uvm/uvm_map.c b/sys/uvm/uvm_map.c
index 30af50d1508..9dc0d92fa4f 100644
--- a/sys/uvm/uvm_map.c
+++ b/sys/uvm/uvm_map.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: uvm_map.c,v 1.57 2003/04/14 04:53:51 art Exp $	*/
+/*	$OpenBSD: uvm_map.c,v 1.58 2003/04/17 03:50:54 drahn Exp $	*/
 /*	$NetBSD: uvm_map.c,v 1.86 2000/11/27 08:40:03 chs Exp $	*/
 
 /* 
@@ -1078,6 +1078,15 @@ uvm_map_spacefits(vm_map_t map, vaddr_t *phint, vsize_t length,
 vaddr_t
 uvm_map_hint(struct proc *p, vm_prot_t prot)
 {
+#ifdef __i386__
+	/*
+	 * If executable skip first two pages, otherwise start
+	 * after data + heap region.
+	 */
+	if ((prot & VM_PROT_EXECUTE) &&
+	    ((vaddr_t)p->p_vmspace->vm_daddr >= 0x40000000))
+		return (round_page(PAGE_SIZE*2));
+#endif
 	return (round_page((vaddr_t)p->p_vmspace->vm_daddr + MAXDSIZ));
 }
 
diff --git a/sys/uvm/uvm_mmap.c b/sys/uvm/uvm_mmap.c
index 0a68cc18275..680f8d5ff87 100644
--- a/sys/uvm/uvm_mmap.c
+++ b/sys/uvm/uvm_mmap.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: uvm_mmap.c,v 1.40 2003/04/14 04:53:51 art Exp $	*/
+/*	$OpenBSD: uvm_mmap.c,v 1.41 2003/04/17 03:50:54 drahn Exp $	*/
 /*	$NetBSD: uvm_mmap.c,v 1.49 2001/02/18 21:19:08 chs Exp $	*/
 
 /*
@@ -166,10 +166,23 @@ sys_mquery(struct proc *p, void *v, register_t *retval)
 	if (vaddr == 0)
 		vaddr = uvm_map_hint(p, prot);
 
+	/* prevent a user requested address from falling in heap space */
+	if ((vaddr + SCARG(uap, size) > (vaddr_t)p->p_vmspace->vm_daddr) &&
+	    (vaddr < (vaddr_t)p->p_vmspace->vm_daddr + MAXDSIZ))
+		vaddr = round_page((vaddr_t)p->p_vmspace->vm_daddr + MAXDSIZ);
+
 	if (uvm_map_findspace(&p->p_vmspace->vm_map, vaddr, SCARG(uap, size),
 	    &vaddr, uobj, uoff, 0, flags) == NULL) {
 		error = ENOMEM;
 	} else {
+		/*
+		 * XXX?
+		 * is it possible for uvm_map_findspace() to return
+		 * an address in vm_addr - vm_addr+MAXDSIZ ?
+		 * if all of the memory below 1G (i386) is used, 
+		 * this could occur. In this case, could this loop
+		 * changing the hint to above daddr in that case?
+		 */
 		error = copyout(&vaddr, SCARG(uap, addr), sizeof(void *));
 	}
 
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