Changes in kernel/generic/include/macros.h [33ca0f5:94795812] in mainline

File:

• kernel/generic/include/macros.h (modified) (2 diffs)

kernel/generic/include/macros.h

@@ -52 +52 @@
     uint64_t sz2)
 {
-        uint64_t e1 = s1 + sz1;
-        uint64_t e2 = s2 + sz2;
-        
-        return ((s1 < e2) && (s2 < e1));
+        uint64_t e1 = s1 + sz1 - 1;
+        uint64_t e2 = s2 + sz2 - 1;
+
+        /* both sizes are non-zero */
+        if (sz1 && sz2)
+                return ((s1 <= e2) && (s2 <= e1));
+
+        /* one size is non-zero */
+        if (sz2)
+                return ((s1 >= s2) && (s1 <= e2));
+        if (sz1)
+                return ((s2 >= s1) && (s2 <= e1));
+
+        /* both are zero */
+        return (s1 == s2);
 }
 
@@ -119 +130 @@
             | ((((uint64_t) (up)) & UINT32_C(0xffffffff)) << 32))
 
+/* Test for sum overflow. */
+#define overflows(a, b) \
+        ((a) + (b) < (a))
+
+/* Test for sum overflow into positive numbers. */
+#define overflows_into_positive(a, b)   \
+        (overflows((a), (b)) && ((a) + (b) > 0))
+
 /** Pseudorandom generator
  *