Re: [PATCH] Disable -Wframe-larger-than warnings with KASAN=y

[Abylay Ospan]

Hello,

Acked-by: Abylay Ospan <aospan@xxxxxxxx>



2015-10-16 19:02 GMT+03:00 Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx>:
> When the kernel compiled with KASAN=y, GCC adds redzones
> for each variable on stack. This enlarges function's stack
> frame and causes:
>         'warning: the frame size of X bytes is larger than Y bytes'
>
> The worst case I've seen for now is following:
>  ../net/wireless/nl80211.c: In function ânl80211_send_wiphyâ:
>  ../net/wireless/nl80211.c:1731:1: warning: the frame size of 5448 bytes is larger than 2048 bytes [-Wframe-larger-than=]
>   }
>    ^
> That kind of warning becomes useless with KASAN=y. It doesn't necessarily
> indicate that there is some problem in the code, thus we should turn it off.
>
> Reported-by: Fengguang Wu <fengguang.wu@xxxxxxxxx>
> Signed-off-by: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx>
> ---
>  lib/Kconfig.debug | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
> index ab76b99..1d1521c 100644
> --- a/lib/Kconfig.debug
> +++ b/lib/Kconfig.debug
> @@ -197,6 +197,7 @@ config ENABLE_MUST_CHECK
>  config FRAME_WARN
>         int "Warn for stack frames larger than (needs gcc 4.4)"
>         range 0 8192
> +       default 0 if KASAN
>         default 1024 if !64BIT
>         default 2048 if 64BIT
>         help
> --
> 2.4.9
>



-- 
Abylay Ospan,
NetUP Inc.
http://www.netup.tv
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