Merge pull request swiftlang#63302 from mikeash/keypath-big-32-bit-pointers

mikeash · web-flow · commit 08e12243a2fa · 2023-02-01T10:22:44.000-05:00
[Runtime] Fix key paths on 32-bit with KVC string pointers in the top half of memory.
diff --git a/stdlib/public/core/KeyPath.swift b/stdlib/public/core/KeyPath.swift
@@ -177,7 +177,9 @@ public class AnyKeyPath: Hashable, _AppendKeyPath {
     }
     else {
       let offset = Int(bitPattern: _kvcKeyPathStringPtr) - 1
-      if (offset <= maximumOffsetOn32BitArchitecture) {
+      // Pointers above 0x7fffffff will come in as negative numbers which are
+      // less than maximumOffsetOn32BitArchitecture, be sure to reject them.
+      if (offset >= 0 && offset <= maximumOffsetOn32BitArchitecture) {
         return offset
       }
       return nil

Original file line number	Diff line number	Diff line change
`@@ -177,7 +177,9 @@ public class AnyKeyPath: Hashable, _AppendKeyPath {`
`177`	`177`	`}`
`178`	`178`	`else {`
`179`	`179`	`let offset = Int(bitPattern: _kvcKeyPathStringPtr) - 1`
`180`		`- if (offset <= maximumOffsetOn32BitArchitecture) {`
	`180`	`+ // Pointers above 0x7fffffff will come in as negative numbers which are`
	`181`	`+ // less than maximumOffsetOn32BitArchitecture, be sure to reject them.`
	`182`	`+ if (offset >= 0 && offset <= maximumOffsetOn32BitArchitecture) {`
`181`	`183`	`return offset`
`182`	`184`	`}`
`183`	`185`	`return nil`