[asan] Don't assert that a target is within 2GB on 32-bit Windows

Summary:
In a 32-bit address space, PC-relative jump targets are wrapped, so a
direct branch at 0x90000001 can reach address 0x10000000 with a
displacement of 0x7FFFFFFFF. This can happen in applications, such as
Chrome, that are linked with /LARGEADDRESSAWARE.

Reviewers: etienneb

Subscribers: mgorny, llvm-commits

Differential Revision: https://reviews.llvm.org/D26650

llvm-svn: 286997

1 files changed, 6 insertions, 0 deletions

diff --git a/compiler-rt/lib/interception/interception_win.cc b/compiler-rt/lib/interception/interception_win.cc
index 8ffc5ae8f83..91abecf6de5 100644
--- a/compiler-rt/lib/interception/interception_win.cc
+++ b/compiler-rt/lib/interception/interception_win.cc
@@ -148,10 +148,16 @@ static void InterceptionFailed() {
 }
 
 static bool DistanceIsWithin2Gig(uptr from, uptr target) {
+#if SANITIZER_WINDOWS64
   if (from < target)
     return target - from <= (uptr)0x7FFFFFFFU;
   else
     return from - target <= (uptr)0x80000000U;
+#else
+  // In a 32-bit address space, the address calculation will wrap, so this check
+  // is unnecessary.
+  return true;
+#endif
 }
 
 static uptr GetMmapGranularity() {