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