On Fri, Jul 14, 2023, at 22:14, Jens Axboe wrote: > On 7/14/23 12:33?PM, Arnd Bergmann wrote: >> On Fri, Jul 14, 2023, at 17:47, Christian Brauner wrote: >>> On Tue, Jul 11, 2023 at 04:18:13PM -0600, Jens Axboe wrote: >>>>>> Does this require argument conversion for compat tasks? >>>>>> >>>>>> Even without the rusage argument, I think the siginfo >>>>>> remains incompatible with 32-bit tasks, unfortunately. >>>>> >>>>> Hmm yes good point, if compat_siginfo and siginfo are different, then it >>>>> does need handling for that. Would be a trivial addition, I'll make that >>>>> change. Thanks Arnd! >>>> >>>> Should be fixed in the current version: >>>> >>>> https://git.kernel.dk/cgit/linux/commit/?h=io_uring-waitid&id=08f3dc9b7cedbd20c0f215f25c9a7814c6c601cc >>> >>> In kernel/signal.c in pidfd_send_signal() we have >>> copy_siginfo_from_user_any() it seems that a similar version >>> copy_siginfo_to_user_any() might be something to consider. We do have >>> copy_siginfo_to_user32() and copy_siginfo_to_user(). But I may lack >>> context why this wouldn't work here. >> >> We could add a copy_siginfo_to_user_any(), but I think open-coding >> it is easier here, since the in_compat_syscall() check does not >> work inside of the io_uring kernel thread, it has to be >> "if (req->ctx->compat)" in order to match the wordsize of the task >> that started the request. > > Yeah, unifying this stuff did cross my mind when adding another one. > Which I think could still be done, you'd just need to pass in a 'compat' > parameter similar to how it's done for iovec importing. > > But if it's ok with everybody I'd rather do that as a cleanup post this. Sure, keeping that separate seem best. Looking at what copy_siginfo_from_user_any() actually does, I don't even think it's worth adapting copy_siginfo_to_user_any() for io_uring, since it's already just a trivial wrapper, and adding another argument would add more complexity overall than it saves. Arnd
