From nobody Sat Feb 7 18:15:39 2026 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 494FB3242CA; Thu, 5 Feb 2026 16:29:41 +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=1770308982; cv=none; b=cFERjksyIsZBMSucYoFaHW3H3QZRLzT8mtNznoo5QI+UyPEw2oBiEGoqEWOqUhpjdcxEEuZXUdgmGakGZL+oqhZ0BlE9WMdjGvogZaRW1sV5IKeNQVNJcPXBxxePddObHJ2xMkhLFQJXCIipIOCL7+FuBL/HXNhCCm7a6L2TBig= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770308982; c=relaxed/simple; bh=se9z/Rx6urcZzEtFxPaxv3F+3lAPdn51/037pyhOCjY=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=lW51+UGS5EcSLOkH+ojTAerbp7rdoJQXVU2sQF/NP/cCnmMPJygg+iuZf+WgFr80d/8msmWcbTqKNSS1ha+FtgXxo33/xZ1BpstCLTK4lioGgRMF8j8HSiSAJewqpGcCxjfJzqTjv8oAP5zNdaq787Coh1RLnPtMJjh3Q7qFQj4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=TtHeHwmc; 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="TtHeHwmc" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 07EF5C4CEF7; Thu, 5 Feb 2026 16:29:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1770308981; bh=se9z/Rx6urcZzEtFxPaxv3F+3lAPdn51/037pyhOCjY=; h=From:To:Cc:Subject:Date:From; b=TtHeHwmcs6wrjMTeeCCDrEaKkJf4aktcaE9m3xEG7ns14BJypYmQZ11SYNHlz6NAO 9L6640DsbaXwHm6Ydwk+4WPv188PWL89v6RGuS9Mb34BynXYDWnAtRrFlJYGb+p1OE wsEKAKyIMqOJM3jTxVcGrNuR0IptjxT06RK+xvvxTnvaGzWBU7Zxlty43KEd2kUBj2 Zm/m1RLVxs54W7Q+Jt/2kgAcCWylc1oRwUoC8VAu7depfR3/UjIhwnYnhlSJbPzyab 0C0guo2zcfY7lM9ejwoBUh60PQfqEqmRtkLvNgONfgcfOgV7B6IWYrUcyBC/GGDDLD U6OM7ucOSL0hg== From: Arnd Bergmann To: Andrew Lunn , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni Cc: Arnd Bergmann , netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] [v4] myri10ge: avoid uninitialized variable use Date: Thu, 5 Feb 2026 17:28:09 +0100 Message-Id: <20260205162935.2126442-1-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 --- v2..v4: address more instances of the same bug --- .../net/ethernet/myricom/myri10ge/myri10ge.c | 28 ++++++++++++++++++- 1 file changed, 27 insertions(+), 1 deletion(-) diff --git a/drivers/net/ethernet/myricom/myri10ge/myri10ge.c b/drivers/net= /ethernet/myricom/myri10ge/myri10ge.c index cea28aa971cc..25b46d8c49e6 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) { @@ -806,6 +809,7 @@ static int myri10ge_update_mac_address(struct myri10ge_= priv *mgp, | (addr[2] << 8) | addr[3]); =20 cmd.data1 =3D ((addr[4] << 8) | (addr[5])); + cmd.data2 =3D 0; =20 status =3D myri10ge_send_cmd(mgp, MXGEFW_SET_MAC_ADDRESS, &cmd, 0); return status; @@ -817,6 +821,9 @@ static int myri10ge_change_pause(struct myri10ge_priv *= mgp, int pause) int status, ctl; =20 ctl =3D pause ? MXGEFW_ENABLE_FLOW_CONTROL : MXGEFW_DISABLE_FLOW_CONTROL; + cmd.data0 =3D 0, + cmd.data1 =3D 0, + cmd.data2 =3D 0, status =3D myri10ge_send_cmd(mgp, ctl, &cmd, 0); =20 if (status) { @@ -834,6 +841,9 @@ 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 +1956,8 @@ 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; @@ -2238,12 +2250,16 @@ static int myri10ge_get_txrx(struct myri10ge_priv *= mgp, 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 *) (mgp->sram + cmd.data0); } cmd.data0 =3D slice; + cmd.data1 =3D 0; + cmd.data2 =3D 0; status |=3D myri10ge_send_cmd(mgp, MXGEFW_CMD_GET_SMALL_RX_OFFSET, &cmd, 0); ss->rx_small.lanai =3D (struct mcp_kreq_ether_recv __iomem *) @@ -2312,6 +2328,7 @@ 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 +2431,8 @@ 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 @@ -2472,7 +2491,6 @@ static int myri10ge_open(struct net_device *dev) static int myri10ge_close(struct net_device *dev) { struct myri10ge_priv *mgp =3D netdev_priv(dev); - struct myri10ge_cmd cmd; int status, old_down_cnt; int i; =20 @@ -2491,8 +2509,13 @@ static int myri10ge_close(struct net_device *dev) =20 netif_tx_stop_all_queues(dev); if (mgp->rebooted =3D=3D 0) { + struct myri10ge_cmd cmd; + old_down_cnt =3D mgp->down_cnt; mb(); + cmd.data0 =3D 0; + cmd.data1 =3D 0; + cmd.data2 =3D 0; status =3D myri10ge_send_cmd(mgp, MXGEFW_CMD_ETHERNET_DOWN, &cmd, 0); if (status) @@ -2956,6 +2979,9 @@ 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