Changeset 33ca0f5 in mainline

Timestamp:

2012-02-09T21:54:30Z (12 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

492ddc9

Parents:

7b5789e

Message:

iswithin() needs to be imune to the base + size 64-bit overflow.

File:

• kernel/generic/include/macros.h (modified) (1 diff)

kernel/generic/include/macros.h

@@ -69 +69 @@
     uint64_t sz2)
 {
-        uint64_t e1 = s1 + sz1;
-        uint64_t e2 = s2 + sz2;
-        
+        uint64_t e1;
+        uint64_t e2;
+
+        /* Handle the two corner cases when either sz1 or sz2 are zero. */
+        if (sz1 == 0)
+                return (s1 == s2) && (sz2 == 0);
+        e1 = s1 + sz1 - 1;      
+        if (sz2 == 0)
+                return (s1 <= s2) && (s2 <= e1);
+        e2 = s2 + sz2 - 1;
+
+        /* e1 and e2 are end addresses, the sum is imune to overflow */
         return ((s1 <= s2) && (e1 >= e2));
 }