Re: [RFC PATCH v2 09/18] livepatch/x86: add TIF_PATCH_PENDING thread flag

From: Josh Poimboeuf
Date: Fri Apr 29 2016 - 16:18:29 EST


On Fri, Apr 29, 2016 at 11:08:04AM -0700, Andy Lutomirski wrote:
> On Thu, Apr 28, 2016 at 1:44 PM, Josh Poimboeuf <jpoimboe@xxxxxxxxxx> wrote:
> > Add the TIF_PATCH_PENDING thread flag to enable the new livepatch
> > per-task consistency model for x86_64. The bit getting set indicates
> > the thread has a pending patch which needs to be applied when the thread
> > exits the kernel.
> >
> > The bit is placed in the least-significant word of the thread_info flags
>
> NAK to that part.
>
> The least-significant word thing is a huge hack that has gotten out of
> control. Please add the thing explicitly to all relevant masks.

Yeah, it is quite dangerous. I'll make it explicit, and make all the
other _TIF_ALLWORK_MASK flags explicit while I'm at it.

--
Josh