On 7/15/23 8:06?AM, Jens Axboe wrote: > On 7/15/23 1:12?AM, Arnd Bergmann wrote: >> 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. > > Yeah, took a look too this morning, and not sure there's much to reduce > here that would make it cleaner. I'm going to send out a v2 with this > unchanged, holler if people disagree. Looking over changes, none have been made so far. So I guess a v2 can wait a bit. The branch was rebased to add Christian's acked-bys for some of the patches, and since a branch it was based on (io_uring-futex) got rebased to accommodate PeterZ's changes. -- Jens Axboe
