[sanitizer] Small tweaks and fixes to allocator related functions

Summary:
In `sanitizer_allocator_primary32.h`:
- rounding up in `MapWithCallback` is not needed as `MmapOrDie` does it. Note
  that the 64-bit counterpart doesn't round up, this keeps the behavior
  consistent;
- since `IsAligned` exists, use it in `AllocateRegion`;
- in `PopulateFreeList`:
  - checking `b->Count` to be greater than 0 when `b->Count() == max_count` is
    redundant when done more than once. Just check that `max_count` is greater
    than 0 out of the loop; the compiler (at least on ARM) didn't optimize it;
  - mark the batch creation failure as `UNLIKELY`;

In `sanitizer_allocator_primary64.h`:
- in `MapWithCallback`, mark the failure condition as `UNLIKELY`;

In `sanitizer_posix.h`:
- mark a bunch of Mmap related failure conditions as `UNLIKELY`;
- in `MmapAlignedOrDieOnFatalError`, we have `IsAligned`, so use it; rearrange
  the conditions as one test was redudant;
- in `MmapFixedImpl`, 30 chars was not large enough to hold the message and a
  full 64-bit address (or at least a 48-bit usermode address), increase to 40.

Reviewers: alekseyshl

Reviewed By: alekseyshl

Subscribers: aemerson, kubamracek, kristof.beyls, llvm-commits

Differential Revision: https://reviews.llvm.org/D34840

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@306834 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 1 insertions, 1 deletions

diff --git a/lib/sanitizer_common/sanitizer_allocator_primary64.h b/lib/sanitizer_common/sanitizer_allocator_primary64.h
index efa2258dd..0c2e72ce7 100644
--- a/lib/sanitizer_common/sanitizer_allocator_primary64.h
+++ b/lib/sanitizer_common/sanitizer_allocator_primary64.h
@@ -389,7 +389,7 @@ class SizeClassAllocator64 {
 
   bool MapWithCallback(uptr beg, uptr size) {
     uptr mapped = reinterpret_cast<uptr>(MmapFixedOrDieOnFatalError(beg, size));
-    if (!mapped)
+    if (UNLIKELY(!mapped))
       return false;
     CHECK_EQ(beg, mapped);
     MapUnmapCallback().OnMap(beg, size);