On Fri, Jul 31, 2020 at 03:20:39PM +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> For arm64: Acked-by: Catalin Marinas <catalin.marinas@xxxxxxx>
