From nobody Thu Oct 9 02:54:20 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 EDD6A78F4A; Fri, 20 Jun 2025 11:26:37 +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=1750418798; cv=none; b=MyEqPnV98+epqXa3E9dtCzSym34f0nAxVlDwLYgaDL0vFGQZPijWuMy/piVimyeDqj/Ns+DXwjENubRPj3w3/U6Btkl/cnCInGhiZj57umph08UezZS1Nrv7XTDrSN8w/B8QD4LfkccSQhaWO8nstoApjRMQBE/wrhht6MKKoG4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750418798; c=relaxed/simple; bh=iYJH96fpJ5ermvw67vAJtEXO+rloBv7/Iorm8b+Imvk=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=tSgYbXaE2UVhjcvZGJy7CLRXHwg5hSO5cI+kMZO9evI/e4wd34Iiggp2RAlxfsJc9phkQ0HL7Wg8zcycyrsK+Yl2yfFLddP8hD93EWgvKf/Aev2IdSqn89cWnaKxJZhh/kPWgqZJLawuoYpdnCIBwADZJ6zPd2e/B47W6RWKnqk= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=jxPlwCJP; 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="jxPlwCJP" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9D6AFC4CEE3; Fri, 20 Jun 2025 11:26:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1750418797; bh=iYJH96fpJ5ermvw67vAJtEXO+rloBv7/Iorm8b+Imvk=; h=From:To:Cc:Subject:Date:From; b=jxPlwCJPPBd+v35RONzc7sxOKTXEXiUkv0/ININzAKMGNXyO8O101aYuewy/xaQ8C 58qMf5AVqI7FFXK3T8nnUaI3Q0+GwtWSbbyxQq0hgcwjTfg/kTg3sQBTtT/jQk6/sk rhP4dIKC9uVCZ/XAgnbKsT8lunu8noJujg1m+pRQXrPQhe3mq9qYlZMysKNQjkCKtC czxxSNiTz8tAoSuprY61tDHrV9ZNwsheShSQjUUOqJc15XvW3GH29lrCgoI+LTwrVT D9itVZfzW3oUzYxngRtaxB48wiwdSe8r6Ek31WUCbWhtZEJn5En4YdBcCZ9pCR5/Uv NJLMF9grpjmBg== From: Arnd Bergmann To: Andrew Lunn , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni Cc: Arnd Bergmann , Thomas Gleixner , Ingo Molnar , netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] myri10ge: avoid uninitialized variable use Date: Fri, 20 Jun 2025 13:26:28 +0200 Message-Id: <20250620112633.3505634-1-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 While compile testing on less common architectures, I noticed that gcc-10 on s390 finds a bug that all other configurations seem to miss: drivers/net/ethernet/myricom/myri10ge/myri10ge.c: In function 'myri10ge_set= _multicast_list': drivers/net/ethernet/myricom/myri10ge/myri10ge.c:391:25: error: 'cmd.data0'= is used uninitialized in this function [-Werror=3Duninitialized] 391 | buf->data0 =3D htonl(data->data0); | ^~ drivers/net/ethernet/myricom/myri10ge/myri10ge.c:392:25: error: '*((void *)= &cmd+4)' is used uninitialized in this function [-Werror=3Duninitialized] 392 | buf->data1 =3D htonl(data->data1); | ^~ drivers/net/ethernet/myricom/myri10ge/myri10ge.c: In function 'myri10ge_all= ocate_rings': drivers/net/ethernet/myricom/myri10ge/myri10ge.c:392:13: error: 'cmd.data1'= is used uninitialized in this function [-Werror=3Duninitialized] 392 | buf->data1 =3D htonl(data->data1); drivers/net/ethernet/myricom/myri10ge/myri10ge.c:1939:22: note: 'cmd.data1'= was declared here 1939 | struct myri10ge_cmd cmd; | ^~~ drivers/net/ethernet/myricom/myri10ge/myri10ge.c:393:13: error: 'cmd.data2'= is used uninitialized in this function [-Werror=3Duninitialized] 393 | buf->data2 =3D htonl(data->data2); drivers/net/ethernet/myricom/myri10ge/myri10ge.c:1939:22: note: 'cmd.data2'= was declared here 1939 | struct myri10ge_cmd cmd; It would be nice to understand how to make other compilers catch this as well, but for the moment I'll just shut up the warning by fixing the undefined behavior in this driver. Signed-off-by: Arnd Bergmann --- drivers/net/ethernet/myricom/myri10ge/myri10ge.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/drivers/net/ethernet/myricom/myri10ge/myri10ge.c b/drivers/net= /ethernet/myricom/myri10ge/myri10ge.c index e611ff7fa3fa..f9d6ba381361 100644 --- a/drivers/net/ethernet/myricom/myri10ge/myri10ge.c +++ b/drivers/net/ethernet/myricom/myri10ge/myri10ge.c @@ -688,6 +688,9 @@ static int myri10ge_get_firmware_capabilities(struct my= ri10ge_priv *mgp) =20 /* probe for IPv6 TSO support */ mgp->features =3D NETIF_F_SG | NETIF_F_HW_CSUM | NETIF_F_TSO; + cmd.data0 =3D 0, + cmd.data1 =3D 0, + cmd.data2 =3D 0, status =3D myri10ge_send_cmd(mgp, MXGEFW_CMD_GET_MAX_TSO6_HDR_SIZE, &cmd, 0); if (status =3D=3D 0) { @@ -834,6 +837,9 @@ myri10ge_change_promisc(struct myri10ge_priv *mgp, int = promisc, int atomic) int status, ctl; =20 ctl =3D promisc ? MXGEFW_ENABLE_PROMISC : MXGEFW_DISABLE_PROMISC; + cmd.data0 =3D 0; + cmd.data1 =3D 0; + cmd.data2 =3D 0; status =3D myri10ge_send_cmd(mgp, ctl, &cmd, atomic); if (status) netdev_err(mgp->dev, "Failed to set promisc mode\n"); @@ -1946,6 +1952,8 @@ static int myri10ge_allocate_rings(struct myri10ge_sl= ice_state *ss) /* get ring sizes */ slice =3D ss - mgp->ss; cmd.data0 =3D slice; + cmd.data1 =3D 0; + cmd.data2 =3D 0; status =3D myri10ge_send_cmd(mgp, MXGEFW_CMD_GET_SEND_RING_SIZE, &cmd, 0); tx_ring_size =3D cmd.data0; cmd.data0 =3D slice; @@ -2238,6 +2246,8 @@ static int myri10ge_get_txrx(struct myri10ge_priv *mg= p, int slice) status =3D 0; if (slice =3D=3D 0 || (mgp->dev->real_num_tx_queues > 1)) { cmd.data0 =3D slice; + cmd.data1 =3D 0; + cmd.data2 =3D 0; status =3D myri10ge_send_cmd(mgp, MXGEFW_CMD_GET_SEND_OFFSET, &cmd, 0); ss->tx.lanai =3D (struct mcp_kreq_ether_send __iomem *) @@ -2312,6 +2322,7 @@ static int myri10ge_open(struct net_device *dev) if (mgp->num_slices > 1) { cmd.data0 =3D mgp->num_slices; cmd.data1 =3D MXGEFW_SLICE_INTR_MODE_ONE_PER_SLICE; + cmd.data2 =3D 0; if (mgp->dev->real_num_tx_queues > 1) cmd.data1 |=3D MXGEFW_SLICE_ENABLE_MULTIPLE_TX_QUEUES; status =3D myri10ge_send_cmd(mgp, MXGEFW_CMD_ENABLE_RSS_QUEUES, @@ -2414,6 +2425,8 @@ static int myri10ge_open(struct net_device *dev) =20 /* now give firmware buffers sizes, and MTU */ cmd.data0 =3D dev->mtu + ETH_HLEN + VLAN_HLEN; + cmd.data1 =3D 0; + cmd.data2 =3D 0; status =3D myri10ge_send_cmd(mgp, MXGEFW_CMD_SET_MTU, &cmd, 0); cmd.data0 =3D mgp->small_bytes; status |=3D @@ -2956,6 +2969,9 @@ static void myri10ge_set_multicast_list(struct net_de= vice *dev) =20 /* Disable multicast filtering */ =20 + cmd.data0 =3D 0; + cmd.data1 =3D 0; + cmd.data2 =3D 0; err =3D myri10ge_send_cmd(mgp, MXGEFW_ENABLE_ALLMULTI, &cmd, 1); if (err !=3D 0) { netdev_err(dev, "Failed MXGEFW_ENABLE_ALLMULTI, error status: %d\n", --=20 2.39.5