[scudo] Fix MallocIterateBoundary on 32 bit.

On Android, the 32 bit value of 8 for BlockDelta results in a
failure because a valid pointer can never be found.

Change the code to always use 16 which passes on both 32 bit
and 64 bit.

Verified that re-introducing the old bug causes the test to fail
on both 32 bit and 64 with the new BlockDelta value.

Reviewed By: Chia-hungDuan

Differential Revision: https://reviews.llvm.org/D152767

diff --git a/compiler-rt/lib/scudo/standalone/tests/wrappers_c_test.cpp b/compiler-rt/lib/scudo/standalone/tests/wrappers_c_test.cpp
index 05d1d48..26bab8d 100644 (file)
--- a/compiler-rt/lib/scudo/standalone/tests/wrappers_c_test.cpp
+++ b/compiler-rt/lib/scudo/standalone/tests/wrappers_c_test.cpp
@@ -333,7 +333,7 @@ static void callback(uintptr_t Base, size_t Size, void *Arg) {
 // block is a boundary for. It must only be seen once by the callback function.
 TEST(ScudoWrappersCTest, MallocIterateBoundary) {
   const size_t PageSize = sysconf(_SC_PAGESIZE);
-  const size_t BlockDelta = FIRST_32_SECOND_64(8U, 16U);
+  const size_t BlockDelta = 16U;
   const size_t SpecialSize = PageSize - BlockDelta;
 
   // We aren't guaranteed that any size class is exactly a page wide. So we need