Merge pull request #27128 from jckarter/reflection-context-alignment-5.1

tkremenek · web-flow · commit 457c6f5d5584 · 2019-09-12T22:46:01.000-07:00
[5.1] ReflectionContext: Keep read range properly aligned.
diff --git a/include/swift/Reflection/ReflectionContext.h b/include/swift/Reflection/ReflectionContext.h
@@ -193,6 +193,11 @@ class ReflectionContext
       }
       RangeStart = std::min(RangeStart, (uint64_t)S->addr + Slide);
       RangeEnd = std::max(RangeEnd, (uint64_t)(S->addr + S->size + Slide));
+      // Keep the range rounded to 8 byte alignment on both ends so we don't
+      // introduce misaligned pointers mapping between local and remote
+      // address space.
+      RangeStart = RangeStart & ~7;
+      RangeEnd = RangeEnd + 7 & ~7;      
     }
  
     if (RangeStart == UINT64_MAX && RangeEnd == UINT64_MAX)

Original file line number	Diff line number	Diff line change
`@@ -193,6 +193,11 @@ class ReflectionContext`
`193`	`193`	`}`
`194`	`194`	`RangeStart = std::min(RangeStart, (uint64_t)S->addr + Slide);`
`195`	`195`	`RangeEnd = std::max(RangeEnd, (uint64_t)(S->addr + S->size + Slide));`
	`196`	`+ // Keep the range rounded to 8 byte alignment on both ends so we don't`
	`197`	`+ // introduce misaligned pointers mapping between local and remote`
	`198`	`+ // address space.`
	`199`	`+ RangeStart = RangeStart & ~7;`
	`200`	`+ RangeEnd = RangeEnd + 7 & ~7;`
`196`	`201`	`}`
`197`	`202`
`198`	`203`	`if (RangeStart == UINT64_MAX && RangeEnd == UINT64_MAX)`