Make page_find() return 0 for too-large addresses (Eduardo Habkost)

On some cases, such as under KVM, tb_invalidate_phys_page_range()
may be called for large addresses, when qemu is configured to more than
4GB of RAM.

On these cases, qemu was crashing because it was using an index too
large for l1_map[], that supports only 32-bit addresses when compiling
without CONFIG_USER_ONLY.

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>



git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5227 c046a42c-6fe2-441c-8c8c-71466251a162

1 files changed, 16 insertions, 6 deletions

diff --git a/exec.c b/exec.c
index 18f46cd25c..c927fbc24d 100644
--- a/exec.c
+++ b/exec.c
@@ -279,17 +279,24 @@ static void page_init(void)
 #endif
 }
 
-static inline PageDesc *page_find_alloc(target_ulong index)
+static inline PageDesc **page_l1_map(target_ulong index)
 {
-    PageDesc **lp, *p;
-
 #if TARGET_LONG_BITS > 32
     /* Host memory outside guest VM.  For 32-bit targets we have already
        excluded high addresses.  */
     if (index > ((target_ulong)L2_SIZE * L1_SIZE))
         return NULL;
 #endif
-    lp = &l1_map[index >> L2_BITS];
+    return &l1_map[index >> L2_BITS];
+}
+
+static inline PageDesc *page_find_alloc(target_ulong index)
+{
+    PageDesc **lp, *p;
+    lp = page_l1_map(index);
+    if (!lp)
+        return NULL;
+
     p = *lp;
     if (!p) {
         /* allocate if not found */
@@ -316,9 +323,12 @@ static inline PageDesc *page_find_alloc(target_ulong index)
 
 static inline PageDesc *page_find(target_ulong index)
 {
-    PageDesc *p;
+    PageDesc **lp, *p;
+    lp = page_l1_map(index);
+    if (!lp)
+        return NULL;
 
-    p = l1_map[index >> L2_BITS];
+    p = *lp;
     if (!p)
         return 0;
     return p + (index & (L2_SIZE - 1));