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UserspaceEmulator: Defer marking MmapRegion as malloc block

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We don't want to audit accesses into the region *while* we're setting
up malloc tracking for it. Fetching the chunk size from the header
was tripping up the auditing code.
This commit is contained in:
Andreas Kling 2021-03-09 11:40:14 +01:00
parent 0b5a915725
commit 915e8dbe71
1 changed files with 14 additions and 11 deletions
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25
Userland/DevTools/UserspaceEmulator/MallocTracer.cpp
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@ -79,22 +79,25 @@ void MallocTracer::target_did_malloc(Badge<Emulator>, FlatPtr address, size_t si
return;
}
MallocRegionMetadata* malloc_data = static_cast<MmapRegion&>(*region).malloc_metadata();
if (!malloc_data) {
if (!mmap_region.is_malloc_block()) {
auto new_malloc_data = make<MallocRegionMetadata>();
malloc_data = new_malloc_data.ptr();
static_cast<MmapRegion&>(*region).set_malloc_metadata({}, move(new_malloc_data));
malloc_data->address = region->base();
malloc_data->chunk_size = mmap_region.read32(offsetof(CommonHeader, m_size)).value();
mmap_region.set_malloc_metadata({}, move(new_malloc_data));
auto& malloc_data = *mmap_region.malloc_metadata();
malloc_data.address = region->base();
malloc_data.chunk_size = mmap_region.read32(offsetof(CommonHeader, m_size)).value();
bool is_chunked_block = malloc_data->chunk_size <= size_classes[num_size_classes - 1];
bool is_chunked_block = malloc_data.chunk_size <= size_classes[num_size_classes - 1];
if (is_chunked_block)
malloc_data->mallocations.resize((ChunkedBlock::block_size - sizeof(ChunkedBlock)) / malloc_data->chunk_size);
malloc_data.mallocations.resize((ChunkedBlock::block_size - sizeof(ChunkedBlock)) / malloc_data.chunk_size);
else
malloc_data->mallocations.resize(1);
dbgln("Tracking malloc block @ {:p} with chunk_size={}, chunk_count={}", malloc_data->address, malloc_data->chunk_size, malloc_data->mallocations.size());
malloc_data.mallocations.resize(1);
// Mark the containing mmap region as a malloc block!
mmap_region.set_malloc(true);
dbgln("Tracking malloc block @ {:p} with chunk_size={}, chunk_count={}", malloc_data.address, malloc_data.chunk_size, malloc_data.mallocations.size());
}
malloc_data->mallocation_for_address(address) = { address, size, true, false, m_emulator.raw_backtrace(), Vector<FlatPtr>() };
mmap_region.malloc_metadata()->mallocation_for_address(address) = { address, size, true, false, m_emulator.raw_backtrace(), Vector<FlatPtr>() };
}
ALWAYS_INLINE Mallocation& MallocRegionMetadata::mallocation_for_address(FlatPtr address) const