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Message-ID: <000001d01c28$41c937c0$c55ba740$@163.com>
Date: Sat, 20 Dec 2014 15:40:39 +0800
From: "Jia-Ju Bai" <baijiaju1990@....com>
To: <todd.fujinaka@...el.com>
Cc: <netdev@...r.kernel.org>, <Linux-nics@...tope.jf.intel.com>,
<linux.nics@...el.com>, <e1000-devel@...ts.sourceforge.net>
Subject: [PATCH]e100 in linux-3.18.0: some potential bugs
I have actually tested e100 driver on the real hardware(Intel 82559 PCI
Ethernet Controller), and find some bugs:
The target file is drivers/net/ethernet/intel/e100.c, which is used to build
e100.ko.
(1) The function pci_pool_create is called by e100_probe when initializing
the ethernet card driver. But when pci_pool_create is failed, which means
that it returns NULL to nic->cbs_pool, the system crash will happen. Because
pci_pool_alloc (in e100_alloc_cbs in e100_up in e100_open) need to use
nic->cbs_pool to allocate the resource, but it is NULL. I suggest that a
check can be added in the code to detect whether pci_pool_create returns
NULL.
(2) In the normal process, netif_napi_add is called in e100_probe, but
netif_napi_del is not called in e100_remove. However, many other ethernet
card drivers call them in pairs, even in the error handling paths, such as
r8169 and igb.
Meanwhile, I also write the patch to fix the bugs. I have run the patch on
the hardware, it can work normally and fix the above bugs.
diff --git a/drivers/net/ethernet/intel/e100.c
b/drivers/net/ethernet/intel/e100.c
index 781065e..2631d3f 100644
--- a/drivers/net/ethernet/intel/e100.c
+++ b/drivers/net/ethernet/intel/e100.c
@@ -2969,6 +2969,11 @@ static int e100_probe(struct pci_dev *pdev, const
struct pci_device_id *ent)
nic->params.cbs.max * sizeof(struct cb),
sizeof(u32),
0);
+ if(!(nic->cbs_pool))
+ {
+ err = -ENOMEM;
+ goto err_out_pool;
+ }
netif_info(nic, probe, nic->netdev,
"addr 0x%llx, irq %d, MAC addr %pM\n",
(unsigned long long)pci_resource_start(pdev, use_io ? 1 :
0),
@@ -2976,6 +2981,8 @@ static int e100_probe(struct pci_dev *pdev, const
struct pci_device_id *ent)
return 0;
+err_out_pool:
+ unregister_netdev(netdev);
err_out_free:
e100_free(nic);
err_out_iounmap:
@@ -2985,6 +2992,7 @@ err_out_free_res:
err_out_disable_pdev:
pci_disable_device(pdev);
err_out_free_dev:
+ netif_napi_del(&nic->napi);
free_netdev(netdev);
return err;
}
@@ -2995,6 +3003,7 @@ static void e100_remove(struct pci_dev *pdev)
if (netdev) {
struct nic *nic = netdev_priv(netdev);
+ netif_napi_del(&nic->napi);
unregister_netdev(netdev);
e100_free(nic);
pci_iounmap(pdev, nic->csr);
Download attachment "patch_e100" of type "application/octet-stream" (1225 bytes)
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