Re: [PATCH v4 1/9] brcmsmac: make some local variables 'static const' to reduce stack size

From: Kalle Valo <kvalo@codeaurora.org>
To: Arnd Bergmann <arnd@arndb.de>
Cc: "Arend van Spriel" <arend.vanspriel@broadcom.com>,
	"Franky Lin" <franky.lin@broadcom.com>,
	"Hante Meuleman" <hante.meuleman@broadcom.com>,
	"Chi-Hsien Lin" <chi-hsien.lin@cypress.com>,
	"Wright Feng" <wright.feng@cypress.com>,
	"Mauro Carvalho Chehab" <mchehab@kernel.org>,
	"Jiri Pirko" <jiri@resnulli.us>,
	"David S. Miller" <davem@davemloft.net>,
	"Andrey Ryabinin" <aryabinin@virtuozzo.com>,
	"Alexander Potapenko" <glider@google.com>,
	"Dmitry Vyukov" <dvyukov@google.com>,
	"Masahiro Yamada" <yamada.masahiro@socionext.com>,
	"Michal Marek" <mmarek@suse.com>,
	"Andrew Morton" <akpm@linux-foundation.org>,
	"Kees Cook" <keescook@chromium.org>,
	"Geert Uytterhoeven" <geert@linux-m68k.org>,
	"Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
	linux-media@vger.kernel.org, linux-kernel@vger.kernel.org,
	netdev@vger.kernel.org, linux-wireless@vger.kernel.org,
	brcm80211-dev-list.pdl@broadcom.com,
	brcm80211-dev-list@cypress.com, kasan-dev@googlegroups.com,
	linux-kbuild@vger.kernel.org, "Jakub Jelinek" <jakub@gcc.gnu.org>,
	"Martin Liška" <marxin@gcc.gnu.org>
Subject: Re: [PATCH v4 1/9] brcmsmac: make some local variables 'static const' to reduce stack size
Date: Mon, 25 Sep 2017 07:33:50 +0300	[thread overview]
Message-ID: <87h8vr75xt.fsf@kamboji.qca.qualcomm.com> (raw)
In-Reply-To: <20170922212930.620249-2-arnd@arndb.de> (Arnd Bergmann's message of "Fri, 22 Sep 2017 23:29:12 +0200")

Arnd Bergmann <arnd@arndb.de> writes:

> With KASAN and a couple of other patches applied, this driver is one
> of the few remaining ones that actually use more than 2048 bytes of
> kernel stack:
>
> broadcom/brcm80211/brcmsmac/phy/phy_n.c: In function 'wlc_phy_workarounds_nphy_gainctrl':
> broadcom/brcm80211/brcmsmac/phy/phy_n.c:16065:1: warning: the frame size of 3264 bytes is larger than 2048 bytes [-Wframe-larger-than=]
> broadcom/brcm80211/brcmsmac/phy/phy_n.c: In function 'wlc_phy_workarounds_nphy':
> broadcom/brcm80211/brcmsmac/phy/phy_n.c:17138:1: warning: the frame size of 2864 bytes is larger than 2048 bytes [-Wframe-larger-than=]
>
> Here, I'm reducing the stack size by marking as many local variables as
> 'static const' as I can without changing the actual code.
>
> This is the first of three patches to improve the stack usage in this
> driver. It would be good to have this backported to stabl kernels
> to get all drivers in 'allmodconfig' below the 2048 byte limit so
> we can turn on the frame warning again globally, but I realize that
> the patch is larger than the normal limit for stable backports.
>
> The other two patches do not need to be backported.
>
> Acked-by: Arend van Spriel <arend.vanspriel@broadcom.com>
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

I'll queue this and the two following brcmsmac patches for 4.14.

Also I'll add (only for this patch):

Cc: <stable@vger.kernel.org>

-- 
Kalle Valo