Module Name: src
Committed By: pooka
Date: Wed Jun 9 12:02:37 UTC 2010
Modified Files:
src/sys/rump/librump/rumpkern: vm.c
Log Message:
On amd64, allocate module_map memory from the lowest 2GB.
To generate a diff of this commit:
cvs rdiff -u -r1.81 -r1.82 src/sys/rump/librump/rumpkern/vm.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/rump/librump/rumpkern/vm.c
diff -u src/sys/rump/librump/rumpkern/vm.c:1.81 src/sys/rump/librump/rumpkern/vm.c:1.82
--- src/sys/rump/librump/rumpkern/vm.c:1.81 Wed Jun 9 11:35:36 2010
+++ src/sys/rump/librump/rumpkern/vm.c Wed Jun 9 12:02:37 2010
@@ -1,4 +1,4 @@
-/* $NetBSD: vm.c,v 1.81 2010/06/09 11:35:36 pooka Exp $ */
+/* $NetBSD: vm.c,v 1.82 2010/06/09 12:02:37 pooka Exp $ */
/*
* Copyright (c) 2007-2010 Antti Kantee. All Rights Reserved.
@@ -43,7 +43,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: vm.c,v 1.81 2010/06/09 11:35:36 pooka Exp $");
+__KERNEL_RCSID(0, "$NetBSD: vm.c,v 1.82 2010/06/09 12:02:37 pooka Exp $");
#include <sys/param.h>
#include <sys/atomic.h>
@@ -528,15 +528,39 @@
vaddr_t
uvm_km_alloc(struct vm_map *map, vsize_t size, vsize_t align, uvm_flag_t flags)
{
- void *rv;
+ void *rv, *desired = NULL;
int alignbit, error;
+#ifdef __x86_64__
+ /*
+ * On amd64, allocate all module memory from the lowest 2GB.
+ * This is because NetBSD kernel modules are compiled
+ * with -mcmodel=kernel and reserve only 4 bytes for
+ * offsets. If we load code compiled with -mcmodel=kernel
+ * anywhere except the lowest or highest 2GB, it will not
+ * work. Since userspace does not have access to the highest
+ * 2GB, use the lowest 2GB.
+ *
+ * Note: this assumes the rump kernel resides in
+ * the lowest 2GB as well.
+ *
+ * Note2: yes, it's a quick hack, but since this the only
+ * place where we care about the map we're allocating from,
+ * just use a simple "if" instead of coming up with a fancy
+ * generic solution.
+ */
+ extern struct vm_map *module_map;
+ if (map == module_map) {
+ desired = (void *)(0x80000000 - size);
+ }
+#endif
+
alignbit = 0;
if (align) {
alignbit = ffs(align)-1;
}
- rv = rumpuser_anonmmap(NULL, size, alignbit, flags & UVM_KMF_EXEC,
+ rv = rumpuser_anonmmap(desired, size, alignbit, flags & UVM_KMF_EXEC,
&error);
if (rv == NULL) {
if (flags & (UVM_KMF_CANFAIL | UVM_KMF_NOWAIT))
