[Xen-devel] [PATCH 2 of 3] Clip mfn to allowable width when building a PTE

[Andres Lagar-Cavilla <andres@xxxxxxxxxxxxxxxx>]

 xen/include/asm-x86/page.h |  12 ++++++++----
 1 files changed, 8 insertions(+), 4 deletions(-)


Otherwise, INVALID_MFN tramples over high order bits used for additional flags.

Signed-off-by: Andres Lagar-Cavilla <andres@xxxxxxxxxxxxxxxx>
Signed-off-by: Tim Deegan <tim@xxxxxxx>

diff -r 642c0e6a01c2 -r e325da663345 xen/include/asm-x86/page.h
--- a/xen/include/asm-x86/page.h
+++ b/xen/include/asm-x86/page.h
@@ -107,13 +107,17 @@
 
 /* Construct a pte from a pfn and access flags. */
 #define l1e_from_pfn(pfn, flags)   \
-    ((l1_pgentry_t) { ((intpte_t)(pfn) << PAGE_SHIFT) | put_pte_flags(flags) })
+    ((l1_pgentry_t) { (((intpte_t)(pfn) << PAGE_SHIFT) & PADDR_MASK)    \
+                        | put_pte_flags(flags) })
 #define l2e_from_pfn(pfn, flags)   \
-    ((l2_pgentry_t) { ((intpte_t)(pfn) << PAGE_SHIFT) | put_pte_flags(flags) })
+    ((l2_pgentry_t) { (((intpte_t)(pfn) << PAGE_SHIFT) & PADDR_MASK)    \
+                        | put_pte_flags(flags) })
 #define l3e_from_pfn(pfn, flags)   \
-    ((l3_pgentry_t) { ((intpte_t)(pfn) << PAGE_SHIFT) | put_pte_flags(flags) })
+    ((l3_pgentry_t) { (((intpte_t)(pfn) << PAGE_SHIFT) & PADDR_MASK)    \
+                        | put_pte_flags(flags) })
 #define l4e_from_pfn(pfn, flags)   \
-    ((l4_pgentry_t) { ((intpte_t)(pfn) << PAGE_SHIFT) | put_pte_flags(flags) })
+    ((l4_pgentry_t) { (((intpte_t)(pfn) << PAGE_SHIFT) & PADDR_MASK)    \
+                        | put_pte_flags(flags) })
 
 /* Construct a pte from a physical address and access flags. */
 #ifndef __ASSEMBLY__

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel