vmm: don't vmap non-canonical addresses

Signed-off-by: Johannes Wikner <[email protected]>

arch/x86/pagetables.c

@@ -92,6 +92,17 @@ static inline void dump_pte(void *entry, mfn_t table, int level, int index) {
            level, index, paddr, flags);
 }
 
+#if defined(__x86_64__)
+static inline int canonical_va(void *va) {
+    int sign = _ul(va) >> 47 & 1;
+    return sign * 0xfffful == _ul(va) >> 48;
+}
+#else
+static inline int canonical_va(void *va) {
+    return 1;
+}
+#endif
+
 static void dump_pagetable(mfn_t table, int level) {
     pte_t *pt;
 
@@ -262,7 +273,7 @@ static void *_vmap(cr3_t *cr3_ptr, void *va, mfn_t mfn, unsigned int order,
     mfn_t l1t_mfn, l2t_mfn, l3t_mfn;
     pgentry_t *tab, *entry;
 
-    if (!va || (_ul(va) & ~PAGE_ORDER_TO_MASK(order)))
+    if (!va || (_ul(va) & ~PAGE_ORDER_TO_MASK(order)) || !canonical_va(va))
         return NULL;
 
     dprintk("%s: va: 0x%p mfn: 0x%lx (order: %u)\n", __func__, va, mfn, order);