Re: [PATCH v2 3/5] kasan, arm64: don't instrument functions that enable kasan

From: Catalin Marinas
Date: Tue Aug 04 2020 - 09:20:34 EST

On Tue, Aug 04, 2020 at 02:41:26PM +0200, Andrey Konovalov wrote:
> This patch prepares Software Tag-Based KASAN for stack tagging support.
> With stack tagging enabled, KASAN tags stack variable in each function
> in its prologue. In start_kernel() stack variables get tagged before KASAN
> is enabled via setup_arch()->kasan_init(). As the result the tags for
> start_kernel()'s stack variables end up in the temporary shadow memory.
> Later when KASAN gets enabled, switched to normal shadow, and starts
> checking tags, this leads to false-positive reports, as proper tags are
> missing in normal shadow.
> Disable KASAN instrumentation for start_kernel(). Also disable it for
> arm64's setup_arch() as a precaution (it doesn't have any stack variables
> right now).
> Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx>

I thought I acked this already. Either way:

Acked-by: Catalin Marinas <catalin.marinas@xxxxxxx>