Module Name: src
Committed By: cherry
Date: Mon Jan 9 12:58:49 UTC 2012
Modified Files:
src/sys/arch/x86/x86: pmap.c
src/sys/arch/xen/x86: xen_pmap.c
Log Message:
Harden cross-cpu L3 sync - avoid optimisations that may race.
Update ci->ci_kpm_pdir from user pmap, not global pmap_kernel() entry which may
get clobbered by other CPUs.
XXX: Look into why we use pmap_kernel() userspace entries at all.
To generate a diff of this commit:
cvs rdiff -u -r1.152 -r1.153 src/sys/arch/x86/x86/pmap.c
cvs rdiff -u -r1.12 -r1.13 src/sys/arch/xen/x86/xen_pmap.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/arch/x86/x86/pmap.c
diff -u src/sys/arch/x86/x86/pmap.c:1.152 src/sys/arch/x86/x86/pmap.c:1.153
--- src/sys/arch/x86/x86/pmap.c:1.152 Mon Jan 9 04:55:35 2012
+++ src/sys/arch/x86/x86/pmap.c Mon Jan 9 12:58:49 2012
@@ -1,4 +1,4 @@
-/* $NetBSD: pmap.c,v 1.152 2012/01/09 04:55:35 cherry Exp $ */
+/* $NetBSD: pmap.c,v 1.153 2012/01/09 12:58:49 cherry Exp $ */
/*-
* Copyright (c) 2008, 2010 The NetBSD Foundation, Inc.
@@ -171,7 +171,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.152 2012/01/09 04:55:35 cherry Exp $");
+__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.153 2012/01/09 12:58:49 cherry Exp $");
#include "opt_user_ldt.h"
#include "opt_lockdebug.h"
@@ -1882,20 +1882,14 @@ pmap_free_ptp(struct pmap *pmap, struct
* If ptp is a L3 currently mapped in kernel space,
* on any cpu, clear it before freeing
*/
- struct cpu_info *ci;
- CPU_INFO_ITERATOR cii;
+ if (level == PTP_LEVELS - 1) {
+ pmap_pte_set(&pmap_kernel()->pm_pdir[index], 0);
+ /*
+ * Update the per-cpu PD on all cpus the current
+ * pmap is active on
+ */
+ xen_kpm_sync(pmap, index);
- for (CPU_INFO_FOREACH(cii, ci)) {
- if (pmap_pdirpa(pmap, 0) == ci->ci_xen_current_user_pgd
- && level == PTP_LEVELS - 1) {
- pmap_pte_set(&pmap_kernel()->pm_pdir[index], 0);
- /*
- * Update the per-cpu PD on all cpus the current
- * pmap is active on
- */
- xen_kpm_sync(pmap, index);
- break;
- }
}
# endif /*__x86_64__ */
invaladdr = level == 1 ? (vaddr_t)ptes :
Index: src/sys/arch/xen/x86/xen_pmap.c
diff -u src/sys/arch/xen/x86/xen_pmap.c:1.12 src/sys/arch/xen/x86/xen_pmap.c:1.13
--- src/sys/arch/xen/x86/xen_pmap.c:1.12 Fri Dec 30 16:55:21 2011
+++ src/sys/arch/xen/x86/xen_pmap.c Mon Jan 9 12:58:49 2012
@@ -1,4 +1,4 @@
-/* $NetBSD: xen_pmap.c,v 1.12 2011/12/30 16:55:21 cherry Exp $ */
+/* $NetBSD: xen_pmap.c,v 1.13 2012/01/09 12:58:49 cherry Exp $ */
/*
* Copyright (c) 2007 Manuel Bouyer.
@@ -102,7 +102,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: xen_pmap.c,v 1.12 2011/12/30 16:55:21 cherry Exp $");
+__KERNEL_RCSID(0, "$NetBSD: xen_pmap.c,v 1.13 2012/01/09 12:58:49 cherry Exp $");
#include "opt_user_ldt.h"
#include "opt_lockdebug.h"
@@ -576,6 +576,8 @@ pmap_kpm_sync_xcall(void *arg1, void *ar
struct pmap *pmap = arg1;
int index = *(int *)arg2;
+ KASSERT(pmap == pmap_kernel() || index < PDIR_SLOT_PTE);
+
struct cpu_info *ci = xpq_cpu();
if (pmap == pmap_kernel()) {
@@ -596,7 +598,7 @@ pmap_kpm_sync_xcall(void *arg1, void *ar
}
pmap_pte_set(&ci->ci_kpm_pdir[index],
- pmap_kernel()->pm_pdir[index]);
+ pmap->pm_pdir[index]);
pmap_pte_flush();
#endif /* PAE || __x86_64__ */
}
@@ -650,6 +652,7 @@ xen_kpm_sync(struct pmap *pmap, int inde
#else /* MULTIPROCESSOR */
#define CPU_IS_CURCPU(ci) __predict_true((ci) == curcpu())
#endif /* MULTIPROCESSOR */
+#if 0 /* XXX: Race with remote pmap_load() */
if (ci->ci_want_pmapload &&
!CPU_IS_CURCPU(ci)) {
/*
@@ -659,7 +662,7 @@ xen_kpm_sync(struct pmap *pmap, int inde
*/
continue;
}
-
+#endif /* 0 */
where = xc_unicast(XC_HIGHPRI, pmap_kpm_sync_xcall,
pmap, &index, ci);
xc_wait(where);
