On Mon, Aug 11, 2014 at 7:11 AM, Guenter Roeck <li...@roeck-us.net> wrote: > On 08/11/2014 04:48 AM, Oleg Nesterov wrote: >> >> On 08/10, Linus Torvalds wrote: >>> >>> >>> So that should just be converted to assert_spin_is_locked(). >> >> >> I still think that lockdep_assert_held() is better. Unlike >> assert_spin_locked() it checks that this lock is held by us, and this >> is what we want in this case. >> > > assert_spin_locked maps to "BUG_ON(!raw_spin_is_locked(x))" > which it seems is exactly what the current code is doing. > I submitted a patch to make that change to use assert_spin_locked. > Presumably the author had a reason for using BUG_ON and not > lockdep_assert_held(), ie to perform the checks all the time > and not just while debugging. For me this was the safe change > to make. Anything else should, in my opinion, come from the > original author who introduced the code.
Thanks for the patch! Yeah, that's a weird case; I think we need some documentation in the header file about the UP vs SMP logic when using spin_is_locked(). I note that all other stuff gets hidden behind the _up and _smp headers. I don't prefer lockdep_assert_held(), though, since I want lock failures to hit BUG. I'll apply the patch and ask James to pull it. Thanks! -Kees -- Kees Cook Chrome OS Security -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
