Messages in this thread | | | Date | Wed, 18 Jun 2014 18:49:09 +0400 | From | Andrey Ryabinin <> | Subject | Re: [PATCH] arm: get rid of hardcoded assumptions about kernel stack size |
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On 06/18/14 18:31, Will Deacon wrote: > On Wed, Jun 18, 2014 at 02:50:22PM +0100, Andrey Ryabinin wrote: >> Changing kernel stack size on arm is not as simple as it should be: >> 1) THRED_SIZE macro doen't respect PAGE_SIZE and THREAD_SIZE_ORDER > > THREAD_SIZE > Yup, I just found some more typos in my commit message. I'll fix them in update.
>> 2) stack size is hardcoded in get_thread_info macro >> >> This patch fixes it by caculating THREAD_SIZE and thread_info address >> taking into account PAGE_SIZE and THREAD_SIZE_ORDER. >> >> Now changing stack size becomes simply changing THREAD_SIZE_ORDER. > > Curious: is this just a cleanup, or are you actually running out of kernel > stack on an ARM platform? >
It's actually both. I'm working on address sanitizer for kernel [1]. Recently we started experiments with stack instrumentation. Compiler inserts redzones around every variable on stack, so we could detect accesses to such redzones and catch out-of-bound read/write bugs on stack variables. Obviously stack is bloated in such kernel. For mainline kernel it just a cleanup.
[1] https://code.google.com/p/address-sanitizer/wiki/AddressSanitizerForKernel
> Will >
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