sel4vm, guest_ram: fix compare function

The compare function assumed the bb region was smaller than the aa region, which isn't always true. This commit checks the edge cases. Signed-off-by: Chris Guikema <[email protected]>
seL4 · Oct 25, 2023 · 91f09d9 · 91f09d9
1 parent de8c0ab
commit 91f09d9
Showing 1 changed file with 8 additions and 1 deletion.
diff --git a/libsel4vm/src/guest_ram.c b/libsel4vm/src/guest_ram.c
@@ -48,7 +48,14 @@ static int ram_region_cmp(const void *a, const void *b)
 {
     const vm_ram_region_t *aa = a;
     const vm_ram_region_t *bb = b;
-    return aa->start - bb->start;
+
+    if (aa->start == bb->start) {
+        return 0;
+    } else if (aa->start < bb->start) {
+        return -1;
+    } else {
+        return 1;
+    }
 }
 
 static void sort_guest_ram_regions(vm_mem_t *guest_memory)