Author: cperciva
Date: Fri Jan 7 14:03:28 2011
New Revision: 217095
URL: http://svn.freebsd.org/changeset/base/217095
Log:
MFC r216944,r216963,r216960: Improve the stability of the i386/XEN pmap
code by correctly protecting page mapping queue variables within a
critical section and by adding ham-fisted locking to pmap.c.
Modified:
stable/8/sys/i386/xen/pmap.c
stable/8/sys/i386/xen/xen_machdep.c
Directory Properties:
stable/8/sys/ (props changed)
stable/8/sys/amd64/include/xen/ (props changed)
stable/8/sys/cddl/contrib/opensolaris/ (props changed)
stable/8/sys/contrib/dev/acpica/ (props changed)
stable/8/sys/contrib/pf/ (props changed)
Modified: stable/8/sys/i386/xen/pmap.c
==============================================================================
--- stable/8/sys/i386/xen/pmap.c Fri Jan 7 12:16:17 2011
(r217094)
+++ stable/8/sys/i386/xen/pmap.c Fri Jan 7 14:03:28 2011
(r217095)
@@ -202,6 +202,11 @@ __FBSDID("$FreeBSD$");
#define pmap_pte_set_prot(pte, v) ((*(int *)pte &= ~PG_PROT), (*(int *)pte |=
(v)))
+#define HAMFISTED_LOCKING
+#ifdef HAMFISTED_LOCKING
+static struct mtx createdelete_lock;
+#endif
+
struct pmap kernel_pmap_store;
LIST_HEAD(pmaplist, pmap);
static struct pmaplist allpmaps;
@@ -502,6 +507,10 @@ pmap_bootstrap(vm_paddr_t firstaddr)
/* Turn on PG_G on kernel page(s) */
pmap_set_pg();
#endif
+
+#ifdef HAMFISTED_LOCKING
+ mtx_init(&createdelete_lock, "pmap create/delete", NULL, MTX_DEF);
+#endif
}
/*
@@ -1510,6 +1519,10 @@ pmap_pinit(pmap_t pmap)
static int color;
int i;
+#ifdef HAMFISTED_LOCKING
+ mtx_lock(&createdelete_lock);
+#endif
+
PMAP_LOCK_INIT(pmap);
/*
@@ -1521,6 +1534,9 @@ pmap_pinit(pmap_t pmap)
NBPTD);
if (pmap->pm_pdir == NULL) {
PMAP_LOCK_DESTROY(pmap);
+#ifdef HAMFISTED_LOCKING
+ mtx_unlock(&createdelete_lock);
+#endif
return (0);
}
#if defined(XEN) && defined(PAE)
@@ -1606,6 +1622,9 @@ pmap_pinit(pmap_t pmap)
TAILQ_INIT(&pmap->pm_pvchunk);
bzero(&pmap->pm_stats, sizeof pmap->pm_stats);
+#ifdef HAMFISTED_LOCKING
+ mtx_unlock(&createdelete_lock);
+#endif
return (1);
}
@@ -1841,6 +1860,10 @@ pmap_release(pmap_t pmap)
pmap->pm_stats.resident_count));
PT_UPDATES_FLUSH();
+#ifdef HAMFISTED_LOCKING
+ mtx_lock(&createdelete_lock);
+#endif
+
pmap_lazyfix(pmap);
mtx_lock_spin(&allpmaps_lock);
LIST_REMOVE(pmap, pm_list);
@@ -1876,6 +1899,10 @@ pmap_release(pmap_t pmap)
pmap_qremove((vm_offset_t)pmap->pm_pdpt, 1);
#endif
PMAP_LOCK_DESTROY(pmap);
+
+#ifdef HAMFISTED_LOCKING
+ mtx_unlock(&createdelete_lock);
+#endif
}
static int
@@ -3242,6 +3269,10 @@ pmap_copy(pmap_t dst_pmap, pmap_t src_pm
CTR5(KTR_PMAP, "pmap_copy: dst_pmap=%p src_pmap=%p dst_addr=0x%x
len=%d src_addr=0x%x",
dst_pmap, src_pmap, dst_addr, len, src_addr);
+#ifdef HAMFISTED_LOCKING
+ mtx_lock(&createdelete_lock);
+#endif
+
vm_page_lock_queues();
if (dst_pmap < src_pmap) {
PMAP_LOCK(dst_pmap);
@@ -3331,6 +3362,10 @@ pmap_copy(pmap_t dst_pmap, pmap_t src_pm
vm_page_unlock_queues();
PMAP_UNLOCK(src_pmap);
PMAP_UNLOCK(dst_pmap);
+
+#ifdef HAMFISTED_LOCKING
+ mtx_unlock(&createdelete_lock);
+#endif
}
static __inline void
Modified: stable/8/sys/i386/xen/xen_machdep.c
==============================================================================
--- stable/8/sys/i386/xen/xen_machdep.c Fri Jan 7 12:16:17 2011
(r217094)
+++ stable/8/sys/i386/xen/xen_machdep.c Fri Jan 7 14:03:28 2011
(r217095)
@@ -42,6 +42,7 @@ __FBSDID("$FreeBSD$");
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/kernel.h>
+#include <sys/proc.h>
#include <sys/reboot.h>
#include <sys/sysproto.h>
@@ -249,10 +250,12 @@ _xen_flush_queue(void)
SET_VCPU();
int _xpq_idx = XPQ_IDX;
int error, i;
- /* window of vulnerability here? */
+#ifdef INVARIANTS
if (__predict_true(gdtset))
- critical_enter();
+ CRITICAL_ASSERT(curthread);
+#endif
+
XPQ_IDX = 0;
/* Make sure index is cleared first to avoid double updates. */
error = HYPERVISOR_mmu_update((mmu_update_t *)&XPQ_QUEUE,
@@ -286,8 +289,6 @@ _xen_flush_queue(void)
}
}
#endif
- if (__predict_true(gdtset))
- critical_exit();
if (__predict_false(error < 0)) {
for (i = 0; i < _xpq_idx; i++)
printf("val: %llx ptr: %llx\n",
@@ -301,7 +302,12 @@ void
xen_flush_queue(void)
{
SET_VCPU();
+
+ if (__predict_true(gdtset))
+ critical_enter();
if (XPQ_IDX != 0) _xen_flush_queue();
+ if (__predict_true(gdtset))
+ critical_exit();
}
static __inline void
_______________________________________________
svn-src-all@freebsd.org mailing list
http://lists.freebsd.org/mailman/listinfo/svn-src-all
To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"
