Re: [PATCH 08/26] brcmsmac: make some local variables 'static const' to reduce stack size

Arend Van Spriel
2017-03-07T10:05:01Z

On 7-3-2017 10:44, Kalle Valo wrote:
> Arnd Bergmann <arnd@arndb.de> writes:
>
>> On Mon, Mar 6, 2017 at 5:19 PM, Kalle Valo <kvalo@codeaurora.org> wrote:
>>> Arend Van Spriel <arend.vanspriel@broadcom.com> writes:
>>>
>>>> On 2-3-2017 17:38, Arnd Bergmann wrote:
>>>>> 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.
>>>>
>>>> Acked-by: Arend van Spriel <arend.vanspriel@broadcom.com>
>>>
>>> Arnd, via which tree are you planning to submit these? I'm not sure
>>> what I should do with the wireless drivers patches from this series.
>>
>> I'm not quite sure myself yet. I'd probably want the first few patches that
>> do most of the work get merged through Andrew's linux-mm tree once
>> we have come to agreement on them. The driver specific patches like
>> the brcmsmac ones depend on the introduction of noinline_for_kasan
>> or noinline_if_stackbloat and could either go in along with the first
>> set, or as a follow-up through the normal maintainer trees.
>
> Either way is fine for me. Just mark clearly if you want the wireless
> drivers patches to go through via my tree, otherwise I'll ignore them.

That (dreaded) phy code does not get a lot of changes so I think it does
not matter which tree is will go through in terms of risk for conflicts.
So going through linux-mm is fine for me as well.

Regards,
Arend