Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932715AbcDSPox (ORCPT ); Tue, 19 Apr 2016 11:44:53 -0400 Received: from bear.ext.ti.com ([192.94.94.41]:55627 "EHLO bear.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932416AbcDSPow (ORCPT ); Tue, 19 Apr 2016 11:44:52 -0400 Subject: Re: [PATCH v2 1/1] drivers: net: cpsw: Prevent NUll pointer dereference with two PHYs To: "David Rivshin (Allworx)" References: <1461074186-25535-1-git-send-email-andrew.goodbody@cambrionix.com> <1461074186-25535-2-git-send-email-andrew.goodbody@cambrionix.com> <57164383.6080103@ti.com> <20160419110140.75e35c3c.drivshin.allworx@gmail.com> CC: Andrew Goodbody , , "David S. Miller" , , , , From: Grygorii Strashko Message-ID: <57165269.40207@ti.com> Date: Tue, 19 Apr 2016 18:44:41 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.6.0 MIME-Version: 1.0 In-Reply-To: <20160419110140.75e35c3c.drivshin.allworx@gmail.com> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 7333 Lines: 181 On 04/19/2016 06:01 PM, David Rivshin (Allworx) wrote: > On Tue, 19 Apr 2016 17:41:07 +0300 > Grygorii Strashko wrote: > >> Hi, >> >> On 04/19/2016 04:56 PM, Andrew Goodbody wrote: >>> Adding a 2nd PHY to cpsw results in a NULL pointer dereference >>> as below. Fix by maintaining a reference to each PHY node in slave >>> struct instead of a single reference in the priv struct which was >>> overwritten by the 2nd PHY. >> >> David, Is it possible to drop prev version of this patch from linux-next >> - it breaks boot on many TI boards with -next. >> >> >>> >>> [ 17.870933] Unable to handle kernel NULL pointer dereference at virtual address 00000180 >>> [ 17.879557] pgd = dc8bc000 >>> [ 17.882514] [00000180] *pgd=9c882831, *pte=00000000, *ppte=00000000 >>> [ 17.889213] Internal error: Oops: 17 [#1] ARM >>> [ 17.893838] Modules linked in: >>> [ 17.897102] CPU: 0 PID: 1657 Comm: connmand Not tainted 4.5.0-ge463dfb-dirty #11 >>> [ 17.904947] Hardware name: Cambrionix whippet >>> [ 17.909576] task: dc859240 ti: dc968000 task.ti: dc968000 >>> [ 17.915339] PC is at phy_attached_print+0x18/0x8c >>> [ 17.920339] LR is at phy_attached_info+0x14/0x18 >>> [ 17.925247] pc : [] lr : [] psr: 600f0113 >>> [ 17.925247] sp : dc969cf8 ip : dc969d28 fp : dc969d18 >>> [ 17.937425] r10: dda7a400 r9 : 00000000 r8 : 00000000 >>> [ 17.942971] r7 : 00000001 r6 : ddb00480 r5 : ddb8cb34 r4 : 00000000 >>> [ 17.949898] r3 : c0954cc0 r2 : c09562b0 r1 : 00000000 r0 : 00000000 >>> [ 17.956829] Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none >>> [ 17.964401] Control: 10c5387d Table: 9c8bc019 DAC: 00000051 >>> [ 17.970500] Process connmand (pid: 1657, stack limit = 0xdc968210) >>> [ 17.977059] Stack: (0xdc969cf8 to 0xdc96a000) >> >> [...] >> >>> [ 18.323956] [] (inet_ioctl) from [] (sock_ioctl+0x15c/0x2d8) >>> [ 18.331829] [] (sock_ioctl) from [] (do_vfs_ioctl+0x98/0x8d0) >>> [ 18.339765] r7:00008914 r6:dc8ab4c0 r5:dd257ae0 r4:beaeda20 >>> [ 18.345822] [] (do_vfs_ioctl) from [] (SyS_ioctl+0x74/0x84) >>> [ 18.353573] r10:00000000 r9:00000011 r8:beaeda20 r7:00008914 r6:dc8ab4c0 r5:dc8ab4c0 >>> [ 18.361924] r4:00000000 >>> [ 18.364653] [] (SyS_ioctl) from [] (ret_fast_syscall+0x0/0x3c) >>> [ 18.372682] r9:dc968000 r8:c00165e8 r7:00000036 r6:00000002 r5:00000011 r4:00000000 >>> [ 18.380960] Code: e92dd810 e24cb010 e24dd010 e59b4004 (e5902180) >>> [ 18.387580] ---[ end trace c80529466223f3f3 ]--- >> >> ^ Could you make it shorter and drop timestamps, pls? >> >>> >>> Signed-off-by: Andrew Goodbody >>> --- >>> >>> v2 - Move allocation of memory for priv->slaves to inside cpsw_probe_dt so it >>> has data->slaves initialised first which is needed to calculate size >>> >>> drivers/net/ethernet/ti/cpsw.c | 30 +++++++++++++++--------------- >>> 1 file changed, 15 insertions(+), 15 deletions(-) >>> >>> diff --git a/drivers/net/ethernet/ti/cpsw.c b/drivers/net/ethernet/ti/cpsw.c >>> index 42fdfd4..e62909c 100644 >>> --- a/drivers/net/ethernet/ti/cpsw.c >>> +++ b/drivers/net/ethernet/ti/cpsw.c >>> @@ -349,6 +349,7 @@ struct cpsw_slave { >>> struct cpsw_slave_data *data; >>> struct phy_device *phy; >>> struct net_device *ndev; >>> + struct device_node *phy_node; >>> u32 port_vlan; >>> u32 open_stat; >>> }; >>> @@ -367,7 +368,6 @@ struct cpsw_priv { >>> spinlock_t lock; >>> struct platform_device *pdev; >>> struct net_device *ndev; >>> - struct device_node *phy_node; >>> struct napi_struct napi_rx; >>> struct napi_struct napi_tx; >>> struct device *dev; >>> @@ -1148,8 +1148,8 @@ static void cpsw_slave_open(struct cpsw_slave *slave, struct cpsw_priv *priv) >>> cpsw_ale_add_mcast(priv->ale, priv->ndev->broadcast, >>> 1 << slave_port, 0, 0, ALE_MCAST_FWD_2); >>> >>> - if (priv->phy_node) >>> - slave->phy = of_phy_connect(priv->ndev, priv->phy_node, >>> + if (slave->phy_node) >>> + slave->phy = of_phy_connect(priv->ndev, slave->phy_node, >>> &cpsw_adjust_link, 0, slave->data->phy_if); >>> else >>> slave->phy = phy_connect(priv->ndev, slave->data->phy_id, >>> @@ -1946,7 +1946,7 @@ static int cpsw_probe_dt(struct cpsw_priv *priv, >>> struct device_node *node = pdev->dev.of_node; >>> struct device_node *slave_node; >>> struct cpsw_platform_data *data = &priv->data; >>> - int i = 0, ret; >>> + int i, ret; >>> u32 prop; >>> >>> if (!node) >>> @@ -1958,6 +1958,14 @@ static int cpsw_probe_dt(struct cpsw_priv *priv, >>> } >>> data->slaves = prop; >>> >>> + priv->slaves = devm_kzalloc(&pdev->dev, >>> + sizeof(struct cpsw_slave) * data->slaves, >>> + GFP_KERNEL); >>> + if (!priv->slaves) >>> + return -ENOMEM; >>> + for (i = 0; i < data->slaves; i++) >>> + priv->slaves[i].slave_num = i; >>> + >>> if (of_property_read_u32(node, "active_slave", &prop)) { >>> dev_err(&pdev->dev, "Missing active_slave property in the DT.\n"); >>> return -EINVAL; >>> @@ -2023,6 +2031,7 @@ static int cpsw_probe_dt(struct cpsw_priv *priv, >>> if (ret) >>> dev_warn(&pdev->dev, "Doesn't have any child node\n"); >>> >>> + i = 0; >>> for_each_child_of_node(node, slave_node) { >>> struct cpsw_slave_data *slave_data = data->slave_data + i; >>> const void *mac_addr = NULL; >>> @@ -2033,7 +2042,8 @@ static int cpsw_probe_dt(struct cpsw_priv *priv, >>> if (strcmp(slave_node->name, "slave")) >>> continue; >>> >>> - priv->phy_node = of_parse_phandle(slave_node, "phy-handle", 0); >>> + priv->slaves[i].phy_node = >>> + of_parse_phandle(slave_node, "phy-handle", 0); >> >> i++? >> >> Ideally, the simplest way is to save phy_node in slave_data, but ... >> (see comment below). > > FYI, I have a patch [1] that does exactly that in my queue. Sorry > I've been busy and haven't had a chance to rebase/retest/resubmit > since Nicolas gave his Tested-By (and I missed Andrew's original > patch). I can probably steal some time to resurrect that quickly > if it's preferred, just let me know. > > [1] http://www.spinics.net/lists/netdev/msg357772.html Ah Ok. There are no user of cpsw_platform_data outside of net/ethernet/ti/, so yes, looks like your patch 1 does exactly what's needed. > >> >> >>> parp = of_get_property(slave_node, "phy_id", &lenp); >>> if (of_phy_is_fixed_link(slave_node)) { >>> struct device_node *phy_node; >>> @@ -2292,16 +2302,6 @@ static int cpsw_probe(struct platform_device *pdev) >>> >>> memcpy(ndev->dev_addr, priv->mac_addr, ETH_ALEN); >>> >>> - priv->slaves = devm_kzalloc(&pdev->dev, >>> - sizeof(struct cpsw_slave) * data->slaves, >>> - GFP_KERNEL); >>> - if (!priv->slaves) { >>> - ret = -ENOMEM; >>> - goto clean_runtime_disable_ret; >>> - } >> I don't think you can move this out from here - it will break legacy boot :( >> >> >>> - for (i = 0; i < data->slaves; i++) >>> - priv->slaves[i].slave_num = i; >> >> Personally, I see only one safe way to do it without big rework - >> do second pass of DT parsing here to fill phy_node field. >> -- regards, -grygorii