[Xen-ia64-devel] pickled code

[Jes Sorensen <jes@xxxxxxx>]

Hi,

I found another interesting issue in the code - the way the 'pickle'
functions work just cannot be right. There is no way one should ever
try and truncate the output of __pa() to u32 or expect to be able to
run __va() on a u32 and obtain any level of usable output.

I have to admit I have zero clue what the pickle code is trying to
achieve, but I am at least fairly confident that something needs to
be done in this space :(

Cheers,
Jes

Truncating __va() and __pa() output to u32 is simply not going to work.
Some platforms don't even have any physical memory within the 4GB window.

Signed-off-by: Jes Sorensen <jes@xxxxxxx>


diff -r 3e4fa8b5b245 xen/arch/ia64/xen/mm.c
--- a/xen/arch/ia64/xen/mm.c    Tue Sep 12 11:43:22 2006 -0600
+++ b/xen/arch/ia64/xen/mm.c    Wed Sep 20 15:47:09 2006 +0200
@@ -213,7 +213,7 @@ static void
 static void
 try_to_clear_PGC_allocate(struct domain* d, struct page_info* page)
 {
-    u32 _d, _nd;
+    u64 _d, _nd;
     u64 x, nx, y;
 
     _d = pickle_domptr(d);
@@ -1329,7 +1349,7 @@ steal_page(struct domain *d, struct page
 #if 0 /* if big endian */
 # error "implement big endian version of steal_page()"
 #endif
-    u32 _d, _nd;
+    u64 _d, _nd;
     u64 x, nx, y;
 
     if (page_get_owner(page) != d) {
diff -r 3e4fa8b5b245 xen/include/asm-ia64/mm.h
--- a/xen/include/asm-ia64/mm.h Tue Sep 12 11:43:22 2006 -0600
+++ b/xen/include/asm-ia64/mm.h Wed Sep 20 14:12:43 2006 +0200
@@ -53,7 +53,7 @@ struct page_info
         /* Page is in use: ((count_info & PGC_count_mask) != 0). */
         struct {
             /* Owner of this page (NULL if page is anonymous). */
-            u32 _domain; /* pickled format */
+            u64 _domain; /* pickled format */
             /* Type reference count and various PGT_xxx flags and fields. */
             unsigned long type_info;
         } __attribute__ ((packed)) inuse;
@@ -125,10 +125,10 @@ struct page_info
 #define IS_XEN_HEAP_FRAME(_pfn) ((page_to_maddr(_pfn) < xenheap_phys_end) \
                                 && (page_to_maddr(_pfn) >= xen_pstart))
 
-static inline struct domain *unpickle_domptr(u32 _d)
+static inline struct domain *unpickle_domptr(u64 _d)
 { return (_d == 0) ? NULL : __va(_d); }
 static inline u32 pickle_domptr(struct domain *_d)
-{ return (_d == NULL) ? 0 : (u32)__pa(_d); }
+{ return (_d == NULL) ? 0 : (u64)__pa(_d); }
 
 #define page_get_owner(_p)     (unpickle_domptr((_p)->u.inuse._domain))
 #define page_set_owner(_p, _d) ((_p)->u.inuse._domain = pickle_domptr(_d))

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