Quoting Sebastian Capella (2014-02-28 15:38:54) > Quoting Lorenzo Pieralisi (2014-02-28 14:49:33) > > On Fri, Feb 28, 2014 at 08:15:57PM +0000, Sebastian Capella wrote: > > > > > > > > This does not guarantee your stack is 8-byte aligned, that's not AAPCS > > > > compliant and might buy you trouble. > > > > > > > > Either you align the stack or you align the pointer you are passing. > > > > > > > > Please have a look at kernel/process.c > > > > > > I've added this for now, do you see any issues? > > > > > > -static u8 resume_stack[PAGE_SIZE/2] __nosavedata; > > > +static u64 resume_stack[PAGE_SIZE/2/sizeof(u64)] __nosavedata; > > > - resume_stack + sizeof(resume_stack)); > > > + resume_stack + ARRAY_SIZE(resume_stack)); > > > > I do not see why the stack depends on the PAGE_SIZE. I would be surprised > > if you need more than a few bytes (given that soft_restart switches stack > > again...), go through it with a debugger, it is easy to check the stack > > usage and allow for some extra buffer (but half a page is not needed). > > I assuming this is becase the no-save region is one page anyway (we skip > restoring the no-save region physical page). So maybe 1/2 is a way to > leave some room for whatever else may need to be here, but in any case > the 4k is used for nosave. I think you're right that it can be much less.
Hi Lorenzo, Are you ok with this just being half a page? Or do you want me to try to reduce the stack size? I am at Connect without my debugger, so in that case it would have to wait until next week. The change for alignment is in as discussed. Thanks! Sebastian -- 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/
