Re: [PATCH] netlink: move nla_put_{u8,u16,u32} out of line

[Arnd Bergmann]

On Thu, Feb 9, 2017 at 6:00 PM, Arnd Bergmann <arnd@xxxxxxxx> wrote:
> To reduce this risk, -fsanitize-address-use-after-scope is now split out
> into a separate Kconfig option, which cannot be selected at the same time
> as CONFIG_KASAN_INLINE, leading to stack frames that are smaller than 2
> kilobytes most of the time on x86_64. Now we can turn on the warning again
> that was disabled in commit 3f181b4 ("lib/Kconfig.debug: disable
> -Wframe-larger-than warnings with KASAN=y").
>
> The hope is that we can fix all code that still produces warnings, so far
> I have found four areas that are still affected (netlink, hisi-hns,
> dvb and tty/keyboard), and I have patches for all of them.

scratch that, my randconfig tests found too many remaining problems
with asan-stack=1 even when only one of CONFIG_KASAN_INLINE
and -fsanitize-address-use-after-scope is set.

I actually get results as bad as
fs/direct-io.c: In function 'do_direct_IO':
fs/direct-io.c:1057:1: error: the frame size of 7240 bytes is larger
than 2048 bytes [-Werror=frame-larger-than=]

with KASAN_OUTLINE=y and KASAN_EXTRA=n.

I need to investigate further to see if I can narrow it down to some
other configuration options.

       Arnd