Hi Josh, On Wed, Nov 22, 2017 at 4:31 AM, Josh Poimboeuf <[email protected]> wrote: > - Make your feature conflict with CONFIG_FRAME_POINTER on x86_64. The > ORC unwinder is now the default anyway for 4.15, and we renamed the > configs, so most people will be actively switching to ORC. > BTW, since CONFIG_FRAME_POINTER is no longer the default and is becoming > deprecated, there has been some talk of disabling objtool with > CONFIG_FRAME_POINTER. That would make your life easier. However I > think we're not quite ready for that, so it might be a few more release > cycles before that happens.
Fortunately my code won't be ready to be merged for a few release cycles, so thanks for letting me know about future plans. I think my patch set and these changes will synchronize nicely. > > - Add some ifdefs so your code only uses %rbp as a scratch register when > CONFIG_FRAME_POINTER is disabled. > - If one of the registers is used less often than the others, you could > spill it to the stack. I know you said you need all the registers, > but I'd be willing to review the code for ideas, if that would help. > Sometimes it helps to get fresh eyes on the problem. We were able to > fix this problem with all the existing crypto code without affecting > performance measurably. We had to get creative with a few of those. That actually could be interesting, if you're curious about looking at it. Jason
