* Rik van Riel <r...@surriel.com> wrote:
> On Mon, 2018-07-16 at 00:59 +0200, Ingo Molnar wrote: > > * Rik van Riel <r...@surriel.com> wrote: > > > > > The mm_struct always contains a cpumask bitmap, regardless of > > > CONFIG_CPUMASK_OFFSTACK. That means the first step can be to > > > simplify things, and simply have one bitmask at the end of the > > > mm_struct for the mm_cpumask. > > > > > > This does necessitate moving everything else in mm_struct into > > > an anonymous sub-structure, which can be randomized when struct > > > randomization is enabled. > > > > > > The second step is to determine the correct size for the > > > mm_struct slab object from the size of the mm_struct > > > (excluding the cpu bitmap) and the size the cpumask. > > > > > > For init_mm we can simply allocate the maximum size this > > > kernel is compiled for, since we only have one init_mm > > > in the system, anyway. > > > > > > Pointer magic by Mike Galbraith, to evade -Wstringop-overflow > > > getting confused by the dynamically sized array. > > > > > > Signed-off-by: Rik van Riel <r...@surriel.com> > > > Signed-off-by: Mike Galbraith <efa...@gmx.de> > > > > Is this an Acked-by in disguise, or did this patch route via Mike? > > Mike found an issue with the patch and sent a > fix, so I added his S-o-b to this patch as > well. Makes sense - I'd suggest such a SoB chain: Signed-off-by: Rik van Riel <r...@surriel.com> [ Fixed crash. ] Signed-off-by: Mike Galbraith <efa...@gmx.de> Signed-off-by: Rik van Riel <r...@surriel.com> ... it's a bit non-standard but we've used it in similar cases and it makes the routing and evolution of the patch pretty clear. Thanks, Ingo