Messages in this thread Patch in this message | | | Date | Thu, 18 Feb 2016 18:13:57 +0000 | From | Catalin Marinas <> | Subject | Re: [PATCH] arm64: kasan: clear stale stack poison |
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On Thu, Feb 18, 2016 at 06:03:54PM +0000, Will Deacon wrote: > On Thu, Feb 18, 2016 at 05:54:47PM +0000, Catalin Marinas wrote: > > On Thu, Feb 18, 2016 at 05:27:38PM +0000, Mark Rutland wrote: > > > @@ -145,6 +146,7 @@ ENTRY(cpu_resume_mmu) > > > ENDPROC(cpu_resume_mmu) > > > .popsection > > > cpu_resume_after_mmu: > > > + kasan_unpoison_stack 96 > > > > I don't think the 96 here is needed since we populate the stack in > > assembly (__cpu_suspend_enter) and unwind it again still in assembly > > (cpu_resume_after_mmu), so no KASAN shadow writes/reads. > > > > Otherwise the patch looks fine. > > I'd much rather it was written in C -- is there a reason we can't do > that if we use a separate compilation unit where the compiler will > honour the fno-sanitize flag?
A simple, non-sanitised C wrapper around __cpu_suspend_enter() would probably work. We need to make sure it is static inline when !KASAN to avoid an unnecessary function call. Or we just move cpu_suspend() to a different compilation unit, though that's a slightly larger function which we may want to track under KASAN.
-- Catalin
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