On Thu, May 30, 2019 at 4:41 PM Oleg Nesterov oleg@redhat.com wrote:
On 05/30, Arnd Bergmann wrote: Plus every file touched by this patch asks for more cleanups. Say, do_poll() should return -ERESTARTNOHAND, not -EINTR, after that we can remove the ugly EINTR->ERESTARTNOHAND in its callers. And more.
For the stable kernels, I think we want just the addition of the 'bool interrupted' argument to restore_user_sigmask()
or simply revert this patch. I will check if this is possible today... At first glance 854a6ed56839a40f6 fixed another bug by accident, do_pselect() did "ret == -ERESTARTNOHAND" after "ret = poll_select_copy_remaining()" which can turn ERESTARTNOHAND into EINTR, but this is simple. I'll check tomorrow.
Right, there were several differences between the system calls that Deepa's original change got rid of. I don't know if any ones besides the do_pselect() return code can be observed in practice.
ret = set_user_sigmask(ksig.sigmask, &ksigmask, &sigsaved, ksig.sigsetsize);
ret = set_xxx(ksig.sigmask, ksig.sigsetsize); if (ret) return ret; ret = do_io_getevents(ctx_id, min_nr, nr, events, timeout ? &ts : NULL);
restore_user_sigmask(ksig.sigmask, &sigsaved);if (signal_pending(current) && !ret)
interrupted = signal_pending(current);update_xxx(interrupted);Maybe name this
restore_saved_sigmask_if(!interrupted);Yes, I thought about restore_if(), but to me
restore_saved_sigmask_if(ret != -EINTR);doesn't look readable... May be
restore_saved_sigmask_unless(ret == -EINTR);? but actually I agree with any naming.
Yes, restore_saved_sigmask_unless() probably better.
With some of the recent discussions about compat syscall handling, I now think that we want to just fold set_compat_user_sigmask() into set_user_sigmask()
agreed, and I thought about this too. But again, I'd prefer to do this and other cleanups later, on top of this patch.
Ok, fair enough. I don't care much about the order as long as the regression fix comes first.
Arnd