On Mon, Oct 08, 2018 at 01:33:14AM -0700, Andy Lutomirski wrote: > > Can't we hijack the relocation records for these functions before they > > get thrown out in the (final) link pass or something? > > I could be talking out my arse here, but I thought we could do this, > too, then changed my mind. The relocation records give us the > location of the call or jump operand, but they don’t give the address > of the beginning of the instruction.
But that's like 1 byte before the operand, right? We could even double check this by reading back that byte and ensuring it is in fact 0xE8 (CALL). AFAICT there is only the _1_ CALL encoding, and that is the 5 byte: E8 <PLT32>, so if we have the PLT32 location, we also have the instruction location. Or am I missing something?
