From nobody Thu Oct 9 01:09:45 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 84BEB1B808; Sat, 21 Jun 2025 19:35:27 +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=1750534527; cv=none; b=tIx+mNLzXfpf69nxPBEcgCGx+4kLNH+Z3nGr2NeKSWtzfpHasdLjeoUD+jyuAJ9raHcIXr7Wmd8bykk2Awsr29yi5LZGPCerROH6fY5I+15giAMcV5ZKRZoRO6jbcLusyr8/3YvFetVGmTLngyQkBXXn1hyWSiY8cVyPR4ZDEHM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750534527; c=relaxed/simple; bh=iRkCqVQGrH7VlO+9U6q1MVEncu/VK7gTCzhyUJEx2FY=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=gqRzfb6G4FuYeNr5DZE2CBBR285LLAjQtP77l3D0rpr2u/qBjvvzMtt+BKFzml4v4ut9I7U3o3b/P7WMflNlS41J5+I6now/XgNYlIHf965Vz1RnEgZ6uM7AOaIT667jWlE5OxmQXD2fE298aAAhxC4VoFMHeG5Hfgj2DdcNz3A= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Ii0+CgVb; 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="Ii0+CgVb" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C9251C4CEE7; Sat, 21 Jun 2025 19:35:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1750534527; bh=iRkCqVQGrH7VlO+9U6q1MVEncu/VK7gTCzhyUJEx2FY=; h=From:To:Cc:Subject:Date:From; b=Ii0+CgVbPT3fYC1KmGf/kH6CdtpLZJRxYnookgmuYuk3hcVkCOwXfpAkZciFhDzYq f2qBaiedTaUwSog0/EC8sfCZTdhWPK+Ui9/ACDmbnF3QZhNyuOoC2fcxXGMnqXIOEW xOqflyFhuPI3ipUIrzX1D8Xl4MDe5RdIuSDf+hLk/2BOqbvwPfgCwHOAOYZ7f0kSls zlWYEktQaboMk3WV2V4LFZdeXSs+CxcBHbd4cToPJqda2ozJMOh2PS9OtHj839RlTc qQ+mV+efexs9ikpm8NPtLjcAJyOPXDqRU3MGF/HCrYi+bVFAaxamKOUPHv5vRrGK7P FfZ9zEZ2CRRnQ== From: Arnd Bergmann To: Andrew Lunn , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni Cc: Simon Horman , Arnd Bergmann , Ingo Molnar , Thomas Gleixner , netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] [v2] myri10ge: avoid uninitialized variable use Date: Sat, 21 Jun 2025 21:35:11 +0200 Message-Id: <20250621193520.620419-1-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: initialize two more instances of these [Simon Horman] --- .../net/ethernet/myricom/myri10ge/myri10ge.c | 20 +++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/drivers/net/ethernet/myricom/myri10ge/myri10ge.c b/drivers/net= /ethernet/myricom/myri10ge/myri10ge.c index e611ff7fa3fa..4743064bc6d4 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; @@ -2238,6 +2250,8 @@ 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 +2326,7 @@ 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 +2429,8 @@ 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 +2973,9 @@ 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