[Drbd-dev] [PATCH 2/2] exec: allow core_pipe recursion check to look for a value of 1 rather than 0 (v2)

[Oleg Nesterov]

On 02/01, Oleg Nesterov wrote:
>
> Oh. And in theory, it is better to change wait_for_helper(). It should
> do allow_signal(SIGCHLD) after kernel_thread(). Otherwise, kernel_thread()
> can fail if user-space sends SIGCHLD to the forking thread.

Well ;) And since allow_signal(SIGCHLD) was called, in theory we should
call sys_wait4() + clear_thread_flag(TIF_SIGPENDING) in a loop to protect
against the false SIGCHLD.

> > > Cough. And why call_usermodehelper_exec() has this strange ->path[0] == '\0'
> > > check?
> > >
> > That I can't explain.  I figured I'd let that sleeping dog lie until this got
> > striaghtened out and fix it separately if it needed it
> > Neil
>
> Yes, yes, agreed. As I said, this has nothing to do with this series,
> even if I am right these (minor) bugs should be fixed separately.

Yes.

Oleg.