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Date: Mon, 18 Mar 2024 09:30:19 +0100
From: "Arnd Bergmann" <arnd@arndb.de>
To: "Dan Carpenter" <dan.carpenter@linaro.org>
Cc: "Philipp Hortmann" <philipp.g.hortmann@gmail.com>,
 "Lee Jones" <lee@kernel.org>,
 "Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
 linux-staging@lists.linux.dev, linux-kernel@vger.kernel.org,
 "Larry Finger" <Larry.Finger@lwfinger.net>,
 "Johannes Berg" <johannes@sipsolutions.net>, "Kalle Valo" <kvalo@kernel.org>,
 "Julia Lawall" <julia.lawall@inria.fr>
Subject: Re: [RFC] staging: wlan-ng: Driver broken since kernel 5.15
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On Mon, Mar 18, 2024, at 09:01, Dan Carpenter wrote:
> On Sun, Mar 17, 2024 at 09:20:34PM +0100, Arnd Bergmann wrote:
>> On Sun, Mar 17, 2024, at 21:07, Philipp Hortmann wrote:
>> > On 3/11/24 08:04, Dan Carpenter wrote:
>> >> On Sat, Mar 09, 2024 at 11:09:24PM +0100, Philipp Hortmann wrote:
>> > You are right with the statement that it is this commit.
>> > commit ea82ff749587807fa48e3277c977ff3cec266f25 (HEAD)
>> > Author: Lee Jones <lee.jones@linaro.org>
>> > Date:   Wed Apr 14 19:10:39 2021 +0100
>> >
>> >      staging: wlan-ng: cfg80211: Move large struct onto the heap
>> >
>> >      Fixes the following W=3D1 kernel build warning(s):
>> >
>> >       drivers/staging/wlan-ng/cfg80211.c: In function =E2=80=98pris=
m2_scan=E2=80=99:
>> >       drivers/staging/wlan-ng/cfg80211.c:388:1: warning: the frame =
size=20
>> > of 1296 bytes is larger than 1024 bytes [-Wframe-larger-than=3D]
>> >
>> > But It is not depending on the line you pointed to.
>>=20
>> Right, the kzalloc() already clears the data, so the memset
>> is not needed.
>>=20
>
> No, it's inside a loop so it needs to be cleared on each iteration.

Right, at least the conversion could not remove the memset()
without a deeper analysis. It's still likely that each
field of the structure still gets initialized properly
inside the loop and the repeated memset() wasn't necessary
in the first place, but that is a completely separate question.

    Arnd