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| author | Dan Albert <danalbert@google.com> | 2015-04-16 11:50:30 -0700 |
|---|---|---|
| committer | Dan Albert <danalbert@google.com> | 2015-04-28 11:10:23 -0700 |
| commit | e48b29b2b99a6b4eceacdbdd60838ad7e789be79 (patch) | |
| tree | aa4e00bace4103991707e42c6240b62d9ada68ae /runtime/gc | |
| parent | 97c96f5aab22f75dd54089bdc194588a4b5a2e8d (diff) | |
| download | art-e48b29b2b99a6b4eceacdbdd60838ad7e789be79.zip art-e48b29b2b99a6b4eceacdbdd60838ad7e789be79.tar.gz art-e48b29b2b99a6b4eceacdbdd60838ad7e789be79.tar.bz2 | |
Prevent undefined behavior in RosAlloc.
In cases where remain == 0, the 32-bit value would be left shifted
32-bits, which is undefined behavior.
Change-Id: I6277279341b168536f928ce87375c395a1aa865c
Diffstat (limited to 'runtime/gc')
| -rw-r--r-- | runtime/gc/allocator/rosalloc.cc | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/runtime/gc/allocator/rosalloc.cc b/runtime/gc/allocator/rosalloc.cc index 85234dc..49c7fda 100644 --- a/runtime/gc/allocator/rosalloc.cc +++ b/runtime/gc/allocator/rosalloc.cc @@ -1042,10 +1042,11 @@ inline size_t RosAlloc::Run::MarkFreeBitMapShared(void* ptr, uint32_t* free_bit_ inline uint32_t RosAlloc::Run::GetBitmapLastVectorMask(size_t num_slots, size_t num_vec) { const size_t kBitsPerVec = 32; - DCHECK_GE(num_slots * kBitsPerVec, num_vec); + DCHECK_GE(num_vec * kBitsPerVec, num_slots); + DCHECK_NE(num_vec, 0U); size_t remain = num_vec * kBitsPerVec - num_slots; - DCHECK_NE(remain, kBitsPerVec); - return ((1U << remain) - 1) << (kBitsPerVec - remain); + DCHECK_LT(remain, kBitsPerVec); + return ((1U << remain) - 1) << ((kBitsPerVec - remain) & 0x1F); } inline bool RosAlloc::Run::IsAllFree() { |