[PATCH v2 11/20] kasan: add and integrate kasan boot parameters

[Catalin Marinas]

On Tue, Nov 10, 2020 at 11:20:15PM +0100, Andrey Konovalov wrote:
> Hardware tag-based KASAN mode is intended to eventually be used in
> production as a security mitigation. Therefore there's a need for finer
> control over KASAN features and for an existence of a kill switch.
> 
> This change adds a few boot parameters for hardware tag-based KASAN that
> allow to disable or otherwise control particular KASAN features.
> 
> The features that can be controlled are:
> 
> 1. Whether KASAN is enabled at all.
> 2. Whether KASAN collects and saves alloc/free stacks.
> 3. Whether KASAN panics on a detected bug or not.
> 
> With this change a new boot parameter kasan.mode allows to choose one of
> three main modes:
> 
> - kasan.mode=off - KASAN is disabled, no tag checks are performed
> - kasan.mode=prod - only essential production features are enabled
> - kasan.mode=full - all KASAN features are enabled

Alternative naming if we want to avoid "production" (in case someone
considers MTE to be expensive in a production system):

- kasan.mode=off
- kasan.mode=on
- kasan.mode=debug

Anyway, whatever you prefer is fine by me:

Acked-by: Catalin Marinas <catalin.marinas at arm.com>