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AK: Align last bump allocated chunk's end offset to the type size too

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Otherwise we can end up freeing garbage memory with some type sizes.
This commit is contained in:
Ali Mohammad Pur 2022-11-03 10:25:11 +03:30 • committed by Ali Mohammad Pur
parent cfcd6e770c
commit bee9412ae4
1 changed files with 4 additions and 4 deletions
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8
AK/BumpAllocator.h
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@ -91,7 +91,7 @@ protected:
if (head_chunk == m_current_chunk) if (head_chunk == m_current_chunk)
VERIFY(chunk_header.next_chunk == 0); VERIFY(chunk_header.next_chunk == 0);
auto next_chunk = chunk_header.next_chunk; auto next_chunk = chunk_header.next_chunk;
fn(head_chunk); fn(head_chunk + sizeof(ChunkHeader));
head_chunk = next_chunk; head_chunk = next_chunk;
} }
} }
@ -179,13 +179,13 @@ public:
void destroy_all() void destroy_all()
{ {
this->for_each_chunk([&](auto chunk) { this->for_each_chunk([&](auto chunk) {
auto base_ptr = align_up_to(chunk + sizeof(typename Allocator::ChunkHeader), alignof(T)); auto base_ptr = align_up_to(chunk, alignof(T));
// Compute the offset of the first byte *after* this chunk: // Compute the offset of the first byte *after* this chunk:
FlatPtr end_offset = base_ptr + this->m_chunk_size - chunk; FlatPtr end_offset = base_ptr + this->m_chunk_size - chunk;
if (chunk == this->m_current_chunk + sizeof(typename Allocator::ChunkHeader))
end_offset = this->m_byte_offset_into_current_chunk;
// Compute the offset of the first byte *after* the last valid object, in case the end of the chunk does not align with the end of an object: // Compute the offset of the first byte *after* the last valid object, in case the end of the chunk does not align with the end of an object:
end_offset = (end_offset / sizeof(T)) * sizeof(T); end_offset = (end_offset / sizeof(T)) * sizeof(T);
if (chunk == this->m_current_chunk)
end_offset = this->m_byte_offset_into_current_chunk;
for (; base_ptr - chunk < end_offset; base_ptr += sizeof(T)) for (; base_ptr - chunk < end_offset; base_ptr += sizeof(T))
reinterpret_cast<T*>(base_ptr)->~T(); reinterpret_cast<T*>(base_ptr)->~T();
}); });