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: >>> On 7/11/23 3:22?PM, Jens Axboe wrote: >>>> On 7/11/23 3:11?PM, Arnd Bergmann 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. > Using copy_siginfo_to_user32() and copy_siginfo_to_user() is > probably a good idea though, it's often faster and less > error-prone than writing each member separately. I was just pattern matching on the other use cases. I'll take a look at the siginfo copy helpers, thanks! -- Jens Axboe
