MSVC can sometimes generate instructions in function prologues that asan previously didn't know the size of. This teaches asan those sizes. This isn't super useful for using ASAN with non-msvc compilers, but it does stand alone.
This is an incorrect machine code instruction; according to my disassembler, EC 8B results in:
in al, dx .byte 8B
which is clearly nonsense; additionally, I notice that it's a reverse of the "correct" two bytes, which says to me that someone got confused by byte to little-endian conversions.
These, OTOH, are correct; however, the constants should be capitalised and the formatting should be made closer to the other cases (same below).
I've not yet taken a look at these, and I need to go home; I'd appreciate if you'd just double check that these are correct (and also fix the formatting).
Style edits (please make the same edits below)
Please actually write out the opcode and operation (same below).
(side note, I really dislike cmp DWORD PTR rather than just cmd DWORD, but no change requested because that's the existing style)