[PATCH] D30101: [asan] Implement "scribble" flag, which overwrites free'd memory with 0x55

[Filipe Cabecinhas via Phabricator via llvm-commits]

filcab added inline comments.


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Comment at: lib/asan/asan_allocator.cc:533
+        uptr size_to_scribble = m->UsedSize() - kChunkHeader2Size;
+        size_to_scribble = Min(size_to_scribble, (uptr)fl.max_malloc_fill_size);
+        REAL(memset)((void *)scribble_start_ptr, 0x55, size_to_scribble);
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If you're re-using `max_malloc_fill_size`, please add to its description that it's also used for scribbling after deallocation.
Otherwise, having different flags for the deallocation scribbling looks good too.


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Comment at: lib/asan/asan_flags.inc:147
+ASAN_FLAG(bool, scribble, false,
+          "On free(), set each byte of released memory to 0x55.")
 ASAN_FLAG(bool, halt_on_error, true,
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`"On deallocation..."`? Since we also set it for `delete`/`delete[]`
I think the current phrasing is understandable, but seems better to phrase it more generally.


https://reviews.llvm.org/D30101