On Tue, Jan 14, 2025 at 03:02:37PM +0100, Jiri Olsa wrote: > hi, > while checking on similar code for uprobes I was wondering if we > can merge first 2 steps of instruction update in text_poke_bp_batch > function. > > Basically the first step now would be to write int3 byte together > with the rest of the bytes of the new instruction instead of doing > that separately. And the second step would be to overwrite int3 > byte with first byte of the new instruction. > > Would that work or do I miss some x86 detail that could lead to crash? I *think* it will work on most modern systems, but I'm very sure I don't have all the details. IIRC this is the magic recipe blessed by both Intel and AMD, and if we're going to be changing this I would want both vendors to sign off on that. > I tried to hack it together in attached patch and it speeds up a bit > text_poke_bp_batch as shown below. Why do we care about performance here?
