Handle -fPIC thunks #8
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Initially reported in alliedmodders/sourcemod#2212, and then unidentified in alliedmodders/sourcemod#2343 and reported again by @dysphie in AM's internal channels. I've decided to have a look at safetyhook internal works and introduce a proper fix for those
__x86_get_pc_thunks.Fix is trivial, each
__x86_get_pc_thunkis basicallyWhere the reg is the one that corresponds to the function name. EAX for AX, ECX for CX, etc...
Those thunks can be easily identified by checking for their opcodes.
If a thunk call is discovered and moved into the trampoline, instead of copying the original bytes, we replace those original bytes with
mov reg, 0xInstructionAddresswhich coincidentally only use 5 bytes, the same amount used to
call __x86_get_pc_thunk.