Use checked_sub for steps_between implementation

phil-opp · phil-opp · commit e2b5d0136fa5 · 2022-03-01T11:21:26.000+01:00
An overflow should not be possible since `VirtAddr` ise guarenteed to be a canoncial address, but it's better to be safe.
diff --git a/src/addr.rs b/src/addr.rs
@@ -335,7 +335,7 @@ impl Step for VirtAddr {
 
         // Check if we jumped the gap.
         if end.0.get_bit(47) && !start.0.get_bit(47) {
-            steps -= 0xffff_0000_0000_0000;
+            steps = steps.checked_sub(0xffff_0000_0000_0000).unwrap();
         }
 
         usize::try_from(steps).ok()

Original file line number	Diff line number	Diff line change
`@@ -335,7 +335,7 @@ impl Step for VirtAddr {`
`335`	`335`
`336`	`336`	`// Check if we jumped the gap.`
`337`	`337`	`if end.0.get_bit(47) && !start.0.get_bit(47) {`
`338`		`- steps -= 0xffff_0000_0000_0000;`
	`338`	`+ steps = steps.checked_sub(0xffff_0000_0000_0000).unwrap();`
`339`	`339`	`}`
`340`	`340`
`341`	`341`	`usize::try_from(steps).ok()`