[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, 3 insertions, 4 deletions

diff --git a/lib/sanitizer_common/sanitizer_allocator_primary32.h b/lib/sanitizer_common/sanitizer_allocator_primary32.h
index d3949cc05..e85821543 100644
--- a/lib/sanitizer_common/sanitizer_allocator_primary32.h
+++ b/lib/sanitizer_common/sanitizer_allocator_primary32.h
@@ -118,7 +118,6 @@ class SizeClassAllocator32 {
   }
 
   void *MapWithCallback(uptr size) {
-    size = RoundUpTo(size, GetPageSizeCached());
     void *res = MmapOrDie(size, "SizeClassAllocator32");
     MapUnmapCallback().OnMap((uptr)res, size);
     return res;
@@ -285,7 +284,7 @@ class SizeClassAllocator32 {
       return 0;
     MapUnmapCallback().OnMap(res, kRegionSize);
     stat->Add(AllocatorStatMapped, kRegionSize);
-    CHECK_EQ(0U, (res & (kRegionSize - 1)));
+    CHECK(IsAligned(res, kRegionSize));
     possible_regions.set(ComputeRegionId(res), static_cast<u8>(class_id));
     return res;
   }
@@ -303,17 +302,17 @@ class SizeClassAllocator32 {
       return false;
     uptr n_chunks = kRegionSize / (size + kMetadataSize);
     uptr max_count = TransferBatch::MaxCached(class_id);
+    CHECK_GT(max_count, 0);
     TransferBatch *b = nullptr;
     for (uptr i = reg; i < reg + n_chunks * size; i += size) {
       if (!b) {
         b = c->CreateBatch(class_id, this, (TransferBatch*)i);
-        if (!b)
+        if (UNLIKELY(!b))
           return false;
         b->Clear();
       }
       b->Add((void*)i);
       if (b->Count() == max_count) {
-        CHECK_GT(b->Count(), 0);
         sci->free_list.push_back(b);
         b = nullptr;
       }