From nobody Tue Oct 7 16:29:36 2025 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8069C1E412A; Tue, 8 Jul 2025 16:06:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751990818; cv=none; b=ooBkndAFIdMXrBsrqem2sGcz8qnrLdMQCGyUQdFsVwAgTG9ShxbPznTjVmQX7Uzwm7FMsrwmDZR2kqY/Co7UrGgMqGNmBXKOurzbBnOJ5s4n75aDXQNQIVqRuSGqDAm00iwYFvwwbDsZITnkBofoNSgd17tfInDn+uz1uWNt6RI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751990818; c=relaxed/simple; bh=u/XqwXMvGwGUcQMh5nLy52xMhImOmTCmv1c95gYdotM=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=Dsuh7PF3zY6OnpPgJKXkj73PfeNmlnd6kBeP/X7zYw7s+KiLDgE71Ua+IwlANqpSrBOuNdB4j+S6+mS7o+S0UdwUUIxEvbe6X1ZkbFzz2LrdVvgNA/2ejm9GpA0+IzhAvXZYqq6zalI/LdjlOqlprpuRRHkq2/BDcRfHFsoF+Dk= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=AyWhgxPm; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="AyWhgxPm" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7CFAFC4CEED; Tue, 8 Jul 2025 16:06:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1751990818; bh=u/XqwXMvGwGUcQMh5nLy52xMhImOmTCmv1c95gYdotM=; h=From:To:Cc:Subject:Date:From; b=AyWhgxPm4VUthsW8kH0LLjf4nC7Z3OyguNy6KeGSZfahJSZhDpml7QFLHsDtvzjAw UmjpQxTvuBMz8LihCgODJIryzaeG8lF1t+aDfz0Zi75I5+LPhHleZIrwbVPFpxz0mt QGeGOlZIsNo6LwErHOx/DORkFI1/vJyIWKf+8491SantSMN9MZxN2LEmp+Eq+Wy1/7 hklB/ZXDnB3oxuScQyCf4Hvro0d8nEpm/SpbmC1XiiZHhMeAlGY6jtTsPz0gZGXeUN B8s8Bw1WkEP2jkzNIlAGC+MBWWxthPqesZj9jAzPel6zHy5YQy56HRTVq7H/ln/XD4 kvLmI1z8bOA4A== From: Arnd Bergmann To: Jiri Pirko , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Carolina Jubran , Tariq Toukan , Cosmin Ratiu , Mark Bloch Cc: Arnd Bergmann , Simon Horman , Joe Damato , Przemek Kitszel , netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] devlink: move DEVLINK_ATTR_MAX-sized array off stack Date: Tue, 8 Jul 2025 18:06:43 +0200 Message-Id: <20250708160652.1810573-1-arnd@kernel.org> X-Mailer: git-send-email 2.39.5 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Arnd Bergmann There are many possible devlink attributes, so having an array of them on the stack can cause a warning for excessive stack usage: net/devlink/rate.c: In function 'devlink_nl_rate_tc_bw_parse': net/devlink/rate.c:382:1: error: the frame size of 1648 bytes is larger tha= n 1536 bytes [-Werror=3Dframe-larger-than=3D] Change this to dynamic allocation instead. Fixes: 566e8f108fc7 ("devlink: Extend devlink rate API with traffic classes= bandwidth management") Signed-off-by: Arnd Bergmann --- I see that only two of the many array entries are actually used in this function: DEVLINK_ATTR_RATE_TC_INDEX and DEVLINK_ATTR_RATE_TC_BW. If there is an interface to extract just a single entry, using that would be a little easier than the kcalloc(). --- net/devlink/rate.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-) diff --git a/net/devlink/rate.c b/net/devlink/rate.c index d39300a9b3d4..e4083649748f 100644 --- a/net/devlink/rate.c +++ b/net/devlink/rate.c @@ -346,19 +346,23 @@ static int devlink_nl_rate_tc_bw_parse(struct nlattr = *parent_nest, u32 *tc_bw, unsigned long *bitmap, struct netlink_ext_ack *extack) { - struct nlattr *tb[DEVLINK_ATTR_MAX + 1]; + struct nlattr **tb; u8 tc_index; int err; =20 + tb =3D kcalloc(DEVLINK_ATTR_MAX + 1, sizeof(struct nlattr *), GFP_KERNEL); + if (!tb) + return -ENOMEM; err =3D nla_parse_nested(tb, DEVLINK_ATTR_MAX, parent_nest, devlink_dl_rate_tc_bws_nl_policy, extack); if (err) - return err; + goto out; =20 + err =3D -EINVAL; if (!tb[DEVLINK_ATTR_RATE_TC_INDEX]) { NL_SET_ERR_ATTR_MISS(extack, parent_nest, DEVLINK_ATTR_RATE_TC_INDEX); - return -EINVAL; + goto out; } =20 tc_index =3D nla_get_u8(tb[DEVLINK_ATTR_RATE_TC_INDEX]); @@ -366,19 +370,21 @@ static int devlink_nl_rate_tc_bw_parse(struct nlattr = *parent_nest, u32 *tc_bw, if (!tb[DEVLINK_ATTR_RATE_TC_BW]) { NL_SET_ERR_ATTR_MISS(extack, parent_nest, DEVLINK_ATTR_RATE_TC_BW); - return -EINVAL; + goto out; } =20 if (test_and_set_bit(tc_index, bitmap)) { NL_SET_ERR_MSG_FMT(extack, "Duplicate traffic class index specified (%u)", tc_index); - return -EINVAL; + goto out; } =20 tc_bw[tc_index] =3D nla_get_u32(tb[DEVLINK_ATTR_RATE_TC_BW]); =20 - return 0; +out: + kfree(tb); + return err; } =20 static int devlink_nl_rate_tc_bw_set(struct devlink_rate *devlink_rate, --=20 2.39.5