Re: [PATCH] ptrace: take into account saved_sigmask in PTRACE_{GET,SET}SIGMASK

[Oleg Nesterov]

On 11/26, Andrei Vagin wrote:
>
> > IOW, could you please explain how PTRACE_SETSIGMASK should be used, and why
> > it doesn't do something like
> >
>
> CRIU uses PTRACE_SETSIGMASK when it injects a parasite code into a
> target process. In this case, we have to be sure that when the process
> is resumed by PTRACE_CONT, it will not start handling signals and
> executing signal handlers.

So iiuc CRUI uses PTRACE_SETSIGMASK to block all signals, run the parasite
code, then restore the original sigmask.

Assuming that CRIU also turns ERESTARTNOHAND into syscall-restart (I think
it does ;) everything looks correct...

OK, I think the patch is fine.

Oleg.