[v5] kni: fix device address set
Checks
Commit Message
Currently, run KNI APP When Kernel version is 5.17. When quit the APP,
dmesg buffer get calltrace, info like:
[ 5965.847401] rte_kni: Creating kni...
[ 6225.627205] vEth0 (unregistered): Current addr: 70 fd 45 d0 72 a7 00..
[ 6225.640113] vEth0 (unregistered): Expected addr: 00 00 00 00 00 00 00..
[ 6225.653010] ------------[ cut here ]------------
[ 6225.657609] netdevice: vEth0 (unregistered): Incorrect netdev->dev_addr
[ 6225.832647] Call trace:
[ 6225.835083] dev_addr_check+0xa0/0x144
[ 6225.838816] dev_addr_flush+0x30/0x9c
[ 6225.842462] free_netdev+0x8c/0x1e0
[ 6225.845939] kni_release+0xc0/0x1d0 [rte_kni]
[ 6225.850281] __fput+0x78/0x220
[ 6225.853327] ____fput+0x1c/0x30
[ 6225.856455] task_work_run+0x88/0xc0
[ 6225.860017] do_exit+0x2fc/0x940
[ 6225.863232] do_group_exit+0x40/0xac
[ 6225.866791] get_signal+0x190/0x960
[ 6225.870265] do_notify_resume+0x26c/0x1360
[ 6225.874346] el0_interrupt+0x60/0xe0
[ 6225.877910] __el0_irq_handler_common+0x18/0x24
[ 6225.882420] el0t_64_irq_handler+0x14/0x20
[ 6225.886499] el0t_64_irq+0x1a0/0x1a4
[ 6225.890059] ---[ end trace 0000000000000000 ]---
[ 6245.598157] rte_kni: Creating kni...
The reason is that 5.17 kernel introduce 'dev_addr_shadow' in function
'dev_addr_set' to ensure that netdev->dev_addr should only be modified
via helpers('dev_addr_set'). 'dev_addr_check' will check if
netdev->dev_addr is modified by other ways, like 'memcpy'.
More info could get by referring to kernel patch:
https://patchwork.kernel.org/project/netdevbpf/patch/
20211118041501.3102861-8-kuba@kernel.org/
https://www.spinics.net/lists/netdev/msg764992.html
Fixes: ea6b39b5b847 ("kni: remove ethtool support")
Signed-off-by: Min Hu (Connor) <humin29@huawei.com>
---
v5:
* define 'HAVE_DEV_ADDR_SHADOW'.
v3,v4:
* fix compiling errors.
v2:
* change 'memcpy' to 'ether_addr_copy' to copy device addr.
---
kernel/linux/kni/compat.h | 4 ++++
kernel/linux/kni/kni_misc.c | 10 ++++++++--
2 files changed, 12 insertions(+), 2 deletions(-)
Comments
On 6/2/22 09:54, Min Hu (Connor) wrote:
> Currently, run KNI APP When Kernel version is 5.17. When quit the APP,
> dmesg buffer get calltrace, info like:
> [ 5965.847401] rte_kni: Creating kni...
> [ 6225.627205] vEth0 (unregistered): Current addr: 70 fd 45 d0 72 a7 00..
> [ 6225.640113] vEth0 (unregistered): Expected addr: 00 00 00 00 00 00 00..
> [ 6225.653010] ------------[ cut here ]------------
> [ 6225.657609] netdevice: vEth0 (unregistered): Incorrect netdev->dev_addr
> [ 6225.832647] Call trace:
> [ 6225.835083] dev_addr_check+0xa0/0x144
> [ 6225.838816] dev_addr_flush+0x30/0x9c
> [ 6225.842462] free_netdev+0x8c/0x1e0
> [ 6225.845939] kni_release+0xc0/0x1d0 [rte_kni]
> [ 6225.850281] __fput+0x78/0x220
> [ 6225.853327] ____fput+0x1c/0x30
> [ 6225.856455] task_work_run+0x88/0xc0
> [ 6225.860017] do_exit+0x2fc/0x940
> [ 6225.863232] do_group_exit+0x40/0xac
> [ 6225.866791] get_signal+0x190/0x960
> [ 6225.870265] do_notify_resume+0x26c/0x1360
> [ 6225.874346] el0_interrupt+0x60/0xe0
> [ 6225.877910] __el0_irq_handler_common+0x18/0x24
> [ 6225.882420] el0t_64_irq_handler+0x14/0x20
> [ 6225.886499] el0t_64_irq+0x1a0/0x1a4
> [ 6225.890059] ---[ end trace 0000000000000000 ]---
> [ 6245.598157] rte_kni: Creating kni...
>
> The reason is that 5.17 kernel introduce 'dev_addr_shadow' in function
> 'dev_addr_set' to ensure that netdev->dev_addr should only be modified
> via helpers('dev_addr_set'). 'dev_addr_check' will check if
> netdev->dev_addr is modified by other ways, like 'memcpy'.
>
> More info could get by referring to kernel patch:
> https://patchwork.kernel.org/project/netdevbpf/patch/
> 20211118041501.3102861-8-kuba@kernel.org/
> https://www.spinics.net/lists/netdev/msg764992.html
>
> Fixes: ea6b39b5b847 ("kni: remove ethtool support")
>
> Signed-off-by: Min Hu (Connor) <humin29@huawei.com>
> ---
> v5:
> * define 'HAVE_DEV_ADDR_SHADOW'.
>
> v3,v4:
> * fix compiling errors.
>
> v2:
> * change 'memcpy' to 'ether_addr_copy' to copy device addr.
> ---
> kernel/linux/kni/compat.h | 4 ++++
> kernel/linux/kni/kni_misc.c | 10 ++++++++--
> 2 files changed, 12 insertions(+), 2 deletions(-)
>
> diff --git a/kernel/linux/kni/compat.h b/kernel/linux/kni/compat.h
> index 664785674f..7ffca63bd4 100644
> --- a/kernel/linux/kni/compat.h
> +++ b/kernel/linux/kni/compat.h
> @@ -141,3 +141,7 @@
> #if KERNEL_VERSION(5, 9, 0) > LINUX_VERSION_CODE
> #define HAVE_TSK_IN_GUP
> #endif
> +
> +#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 17, 0)
> +#define HAVE_DEV_ADDR_SHADOW
> +#endif
> diff --git a/kernel/linux/kni/kni_misc.c b/kernel/linux/kni/kni_misc.c
> index 780187d8bf..0470d349c5 100644
> --- a/kernel/linux/kni/kni_misc.c
> +++ b/kernel/linux/kni/kni_misc.c
> @@ -299,6 +299,7 @@ kni_ioctl_create(struct net *net, uint32_t ioctl_num,
> struct kni_net *knet = net_generic(net, kni_net_id);
> int ret;
> struct rte_kni_device_info dev_info;
> + unsigned char mac_addr[ETH_ALEN];
> struct net_device *net_dev = NULL;
> struct kni_dev *kni, *dev, *n;
>
> @@ -403,10 +404,15 @@ kni_ioctl_create(struct net *net, uint32_t ioctl_num,
>
> /* if user has provided a valid mac address */
> if (is_valid_ether_addr(dev_info.mac_addr))
> - memcpy(net_dev->dev_addr, dev_info.mac_addr, ETH_ALEN);
> + ether_addr_copy(mac_addr, dev_info.mac_addr);
> else
> /* Generate random MAC address. */
> - eth_random_addr(net_dev->dev_addr);
> + eth_random_addr(mac_addr);
The following point from Stephen is still not processed:
<quote>
This is still not the best way to handle this.
If you use eth_hw_addr_random() it will set the address assign type.
Right now KNI is not doing this correctly.
</quote>
> +#ifdef HAVE_DEV_ADDR_SHADOW
> + dev_addr_set(net_dev, mac_addr);
> +#else
> + ether_addr_copy(net_dev->dev_addr, mac_addr);
> +#endif
>
> if (dev_info.mtu)
> net_dev->mtu = dev_info.mtu;
@@ -141,3 +141,7 @@
#if KERNEL_VERSION(5, 9, 0) > LINUX_VERSION_CODE
#define HAVE_TSK_IN_GUP
#endif
+
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 17, 0)
+#define HAVE_DEV_ADDR_SHADOW
+#endif
@@ -299,6 +299,7 @@ kni_ioctl_create(struct net *net, uint32_t ioctl_num,
struct kni_net *knet = net_generic(net, kni_net_id);
int ret;
struct rte_kni_device_info dev_info;
+ unsigned char mac_addr[ETH_ALEN];
struct net_device *net_dev = NULL;
struct kni_dev *kni, *dev, *n;
@@ -403,10 +404,15 @@ kni_ioctl_create(struct net *net, uint32_t ioctl_num,
/* if user has provided a valid mac address */
if (is_valid_ether_addr(dev_info.mac_addr))
- memcpy(net_dev->dev_addr, dev_info.mac_addr, ETH_ALEN);
+ ether_addr_copy(mac_addr, dev_info.mac_addr);
else
/* Generate random MAC address. */
- eth_random_addr(net_dev->dev_addr);
+ eth_random_addr(mac_addr);
+#ifdef HAVE_DEV_ADDR_SHADOW
+ dev_addr_set(net_dev, mac_addr);
+#else
+ ether_addr_copy(net_dev->dev_addr, mac_addr);
+#endif
if (dev_info.mtu)
net_dev->mtu = dev_info.mtu;