Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Sun, 9 Jul 2023 15:07:01 +0700
From:   Bagas Sanjaya <bagasdotme@gmail.com>
To:     wardenjohn <ydzhang@linux.alibaba.com>
Cc:     jpoimboe <jpoimboe@kernel.org>, jikos <jikos@kernel.org>,
        mbenes <mbenes@suse.cz>, pmladek <pmladek@suse.com>,
        "joe.lawrence" <joe.lawrence@redhat.com>,
        Kernel Live Patching <live-patching@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: Fix MAX_STACK_ENTRIES from 100 to 32
Message-ID: <ZKpqpamE89nvgslC@debian.me>
References: <931aaecf-66b1-469a-8bc3-7126871a8464.ydzhang@linux.alibaba.com>
MIME-Version: 1.0
Content-Type: multipart/signed; micalg=pgp-sha512;
        protocol="application/pgp-signature"; boundary="YrNPC+OEMpEeAcTM"
Content-Disposition: inline
In-Reply-To: <931aaecf-66b1-469a-8bc3-7126871a8464.ydzhang@linux.alibaba.com>
Precedence: bulk


--YrNPC+OEMpEeAcTM
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
Content-Transfer-Encoding: quoted-printable

On Sat, Jul 08, 2023 at 09:56:34AM +0800, wardenjohn wrote:
> Thanks for reading my suggestion. I found that the array for task stack e=
ntries when
> doing livepatch function check is too large which seems to be unnecessary=
=2E Therefore,
> I suggest to fix the MAX_STACK_ENTRIES from 100 to 32.

Can you provide Link: to the discussion? Yet, I guess this is somehow
v2 patch.

>=20
> The patch is as follows:
>=20
> From ee27da5e64daced159257f54170a31141e943710 Mon Sep 17 00:00:00 2001
> From: Yongde Zhang <ydzhang@linux.alibaba.com>
> Date: Sat, 8 Jul 2023 09:40:50 +0800
> Subject: [PATCH] Fix MAX_STACK_ENTRIES to 32
>=20
> When checking the task stack, using an stack array of size 100=20
> seems to be to large for a task stack. Therefore, I suggest to
> change the stack size from 100 to 32.=20

Why is MAX_STACK_ENTRIES=3D100 overkill? And why do you reduce it?

>=20
> Signed-off-by: Yongde Zhang <ydzhang@linux.alibaba.com>
> ---
>  kernel/livepatch/transition.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>=20
> diff --git a/kernel/livepatch/transition.c b/kernel/livepatch/transition.c
> index e54c3d60a904..8d61c62b0c27 100644
> --- a/kernel/livepatch/transition.c
> +++ b/kernel/livepatch/transition.c
> @@ -14,7 +14,7 @@
>  #include "patch.h"
>  #include "transition.h"
> =20
> -#define MAX_STACK_ENTRIES  100
> +#define MAX_STACK_ENTRIES  32
>  static DEFINE_PER_CPU(unsigned long[MAX_STACK_ENTRIES], klp_stack_entrie=
s);
> =20
>  #define STACK_ERR_BUF_SIZE 128=20

Your patch is MIME'd, please submit it with git-send-email(1) instead.

Thanks.

--=20
An old man doll... just what I always wanted! - Clara

--YrNPC+OEMpEeAcTM
Content-Type: application/pgp-signature; name="signature.asc"

-----BEGIN PGP SIGNATURE-----

iHUEABYKAB0WIQSSYQ6Cy7oyFNCHrUH2uYlJVVFOowUCZKpqoQAKCRD2uYlJVVFO
o2lGAP9sqV+kuxkKPjIXC+EDhICkPGQGyJ4ZZjXLqtr+lEhRXAEAmBy1p3nykzVq
Q17J1o0wFZVmeG+P+wN3flSRKoqecgw=
=w/f9
-----END PGP SIGNATURE-----

--YrNPC+OEMpEeAcTM--