Reimplement uvm/uvm_map.

vmmap is designed to perform address space randomized allocations,
without letting fragmentation of the address space go through the roof.

Some highlights:
- kernel address space randomization
- proper implementation of guardpages
- roughly 10% system time reduction during kernel build

Tested by alot of people on tech@ and developers.
Theo's machines are still happy.

1 files changed, 13 insertions, 11 deletions

diff --git a/sys/kern/exec_elf.c b/sys/kern/exec_elf.c
index 980f49431ed..d4bdfd1ba7e 100644
--- a/sys/kern/exec_elf.c
+++ b/sys/kern/exec_elf.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: exec_elf.c,v 1.81 2011/04/18 21:44:56 guenther Exp $	*/
+/*	$OpenBSD: exec_elf.c,v 1.82 2011/05/24 15:27:36 ariane Exp $	*/
 
 /*
  * Copyright (c) 1996 Per Fogelstrom
@@ -333,6 +333,7 @@ ELFNAME(load_file)(struct proc *p, char *path, struct exec_package *epp,
 	int nload, idx = 0;
 	Elf_Addr pos = *last;
 	int file_align;
+	int loop;
 
 	NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, path, p);
 	if ((error = namei(&nd)) != 0) {
@@ -389,6 +390,7 @@ ELFNAME(load_file)(struct proc *p, char *path, struct exec_package *epp,
 
 	pos = ELF_ROUND(pos, file_align);
 	*last = epp->ep_interp_pos = pos;
+	loop = 0;
 	for (i = 0; i < nload;/**/) {
 		vaddr_t	addr;
 		struct	uvm_object *uobj;
@@ -416,17 +418,17 @@ ELFNAME(load_file)(struct proc *p, char *path, struct exec_package *epp,
 			addr = round_page((vaddr_t)p->p_vmspace->vm_daddr +
 			    BRKSIZ);
 
-		vm_map_lock(&p->p_vmspace->vm_map);
-		if (uvm_map_findspace(&p->p_vmspace->vm_map, addr, size,
-		    &addr, uobj, uoff, 0, UVM_FLAG_FIXED) == NULL) {
-			if (uvm_map_findspace(&p->p_vmspace->vm_map, addr, size,
-			    &addr, uobj, uoff, 0, 0) == NULL) {
-				error = ENOMEM; /* XXX */
-				vm_map_unlock(&p->p_vmspace->vm_map);
-				goto bad1;
+		if (uvm_map_mquery(&p->p_vmspace->vm_map, &addr, size,
+		    (i == 0 ? uoff : UVM_UNKNOWN_OFFSET), 0) != 0) {
+			if (loop == 0) {
+				loop = 1;
+				i = 0;
+				*last = epp->ep_interp_pos = pos = 0;
+				continue;
 			}
-		} 
-		vm_map_unlock(&p->p_vmspace->vm_map);
+			error = ENOMEM;
+			goto bad1;
+		}
 		if (addr != pos + loadmap[i].vaddr) {
 			/* base changed. */
 			pos = addr - trunc_page(loadmap[i].vaddr);