Re: Fw: 2.5.61 oops running SDET

Linus Torvalds
2003-02-16T23:26:04Z

On Sun, 16 Feb 2003, Martin J. Bligh wrote:
>
> So what does protect sighand? tasklist_lock?

Yup. At least right now. And we do tend to hold tasklist_lock in most
cases simply by virtue of having to get it anyway in order to search for
the process.

> It doesn't seem to
> as people do things like:
>
> spin_unlock_irq(&current->sighand->siglock);
>
> all the time ... so is it just protected by good faith and the direction
> of the wind?

Agreed. That, and the fact that most of the time the stuff _is_ there:
obviously any time the process looks at its own signals it will always be
there.

So we have two cases:
- "normal" signal sending which holds tasklist_lock to find the target.
- signals to the process itself, which is usually safe, since we know
we're there (the exception would be if/when taking a fault in the exit
path, but even that might be ok since signals are torn down not by exit
itself but by "release_task")

So the signal path may actually be ok.

Linus