From: Linus Torvalds > Sent: 05 June 2019 18:25 > On Wed, Jun 5, 2019 at 8:58 AM Oleg Nesterov <oleg@xxxxxxxxxx> wrote: > > > > To simplify the review, please see the code with this patch applied. > > I am using epoll_pwait() as an example because it looks very simple. > > I like it. > > However. > > I think I'd like it even more if we just said "we don't need > restore_saved_sigmask AT ALL". > > Which would be fairly easy to do with something like the attached... That would always call the signal handlers even when EINTR wasn't being returned (which I think ought to happen ...). The real purpose of restore_saved_sigmask() is to stop signal handlers that are enabled by the temporary mask being called. If a signal handler is called, I presume that the trampoline calls back into the kernel to get further handlers called and to finally restore the original signal mask? What happens if a signal handler calls something that would normally write to current->saved_sigmask? David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)
