Re: [PATCH 2/3] kasan: disable CONFIG_KASAN_STACK with clang on arm32

From: Linus Walleij
Date: Mon Jul 08 2019 - 10:32:41 EST


On Wed, Jul 3, 2019 at 10:56 PM Arnd Bergmann <arnd@xxxxxxxx> wrote:

> The CONFIG_KASAN_STACK symbol tells us whether we should be using the
> asan-stack=1 parameter. On clang-8, this causes explosive kernel stack
> frame growth, so it is currently disabled, hopefully to be turned back
> on when a future clang version is fixed. Examples include
>
> drivers/media/dvb-frontends/mb86a20s.c:1942:12: error: stack frame size of 4128 bytes in function
> drivers/net/wireless/atmel/atmel.c:1307:5: error: stack frame size of 4928 bytes in function 'atmel_open'
> drivers/gpu/drm/nouveau/nvkm/subdev/fb/ramgk104.c:1521:1: error: stack frame size of 5440 bytes in function
> drivers/media/i2c/mt9t112.c:670:12: error: stack frame size of 9344 bytes in function 'mt9t112_init_camera'
> drivers/video/fbdev/omap2/omapfb/displays/panel-tpo-td028ttec1.c:185:12: error: stack frame size of 10048 bytes
>
> For the 32-bit ARM build, the logic I introduced earlier does
> not work because $(CFLAGS_KASAN_SHADOW) is empty, and we don't add
> those flags.
>
> Moving the asan-stack= parameter down fixes this. No idea of any
> of the other parameters should also be moved though.
>
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>

For some reason the RealView doesn't boot after this patch. Trying to figure
out why.

Yours,
Linus Walleij