[Xen-changelog] [xen-unstable] x86, 32-on-64: Improve checking in vcpu_destroy_pagetables(). It *is*

[Xen patchbot-unstable <patchbot-unstable@xxxxxxxxxxxxxxxxxxx>]

# HG changeset patch
# User Keir Fraser <keir.fraser@xxxxxxxxxx>
# Date 1195572865 0
# Node ID f62e6c697eeb68a7a62f4beb87e85a68b91b3c6a
# Parent  94b3979606cd9c4e9202bc59209b9d0c897f7689
x86, 32-on-64: Improve checking in vcpu_destroy_pagetables(). It *is*
possible for 64-bit guest to have matching guest_table and
guest_table_user.
Original patch by John Levon <levon@xxxxxxxxxxxxxxxxx>
Signed-off-by: Keir Fraser <keir.fraser@xxxxxxxxxxxxx>
---
 xen/arch/x86/domain.c |   15 +++++++--------
 1 files changed, 7 insertions(+), 8 deletions(-)

diff -r 94b3979606cd -r f62e6c697eeb xen/arch/x86/domain.c
--- a/xen/arch/x86/domain.c     Tue Nov 20 15:18:09 2007 +0000
+++ b/xen/arch/x86/domain.c     Tue Nov 20 15:34:25 2007 +0000
@@ -1756,10 +1756,6 @@ static void vcpu_destroy_pagetables(stru
             put_page(mfn_to_page(pfn));
         else
             put_page_and_type(mfn_to_page(pfn));
-#ifdef __x86_64__
-        if ( pfn == pagetable_get_pfn(v->arch.guest_table_user) )
-            v->arch.guest_table_user = pagetable_null();
-#endif
         v->arch.guest_table = pagetable_null();
     }
 
@@ -1768,10 +1764,13 @@ static void vcpu_destroy_pagetables(stru
     pfn = pagetable_get_pfn(v->arch.guest_table_user);
     if ( pfn != 0 )
     {
-        if ( paging_mode_refcounts(d) )
-            put_page(mfn_to_page(pfn));
-        else
-            put_page_and_type(mfn_to_page(pfn));
+        if ( !is_pv_32bit_vcpu(v) )
+        {
+            if ( paging_mode_refcounts(d) )
+                put_page(mfn_to_page(pfn));
+            else
+                put_page_and_type(mfn_to_page(pfn));
+        }
         v->arch.guest_table_user = pagetable_null();
     }
 #endif

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