[PATCH v2] examples/kni: clear warning about discarding const qualifier

[PATCH v2] examples/kni: clear warning about discarding const qualifier

[Ke Zhang]

The warning info:
warning: passing argument 1 of ‘memcpy’ discards ‘const’
qualifier from pointer target type

Variable is done const intentionally to prevent using it
directly, using the new helper functions :
'eth_hw_addr_set()' and 'eth_hw_addr_random()'

Fixes: ea6b39b5b847 ("kni: remove ethtool support")
Cc: stable@dpdk.org

Signed-off-by: Ke Zhang <ke1x.zhang@intel.com>
---
 kernel/linux/kni/kni_misc.c | 4 ++--
 kernel/linux/kni/kni_net.c  | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/kernel/linux/kni/kni_misc.c b/kernel/linux/kni/kni_misc.c
index 780187d8bf..1da8e812b7 100644
--- a/kernel/linux/kni/kni_misc.c
+++ b/kernel/linux/kni/kni_misc.c
@@ -403,10 +403,10 @@ 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);
+		eth_hw_addr_set(net_dev, dev_info.mac_addr);
 	else
 		/* Generate random MAC address. */
-		eth_random_addr(net_dev->dev_addr);
+		eth_hw_addr_random(net_dev);
 
 	if (dev_info.mtu)
 		net_dev->mtu = dev_info.mtu;
diff --git a/kernel/linux/kni/kni_net.c b/kernel/linux/kni/kni_net.c
index 29e5b9e21f..1da4f836aa 100644
--- a/kernel/linux/kni/kni_net.c
+++ b/kernel/linux/kni/kni_net.c
@@ -779,7 +779,7 @@ kni_net_set_mac(struct net_device *netdev, void *p)
 		return -EADDRNOTAVAIL;
 
 	memcpy(req.mac_addr, addr->sa_data, netdev->addr_len);
-	memcpy(netdev->dev_addr, addr->sa_data, netdev->addr_len);
+	eth_hw_addr_set(netdev, addr->sa_data);
 
 	ret = kni_net_process_request(netdev, &req);
 
-- 
2.25.1

Re: [PATCH v2] examples/kni: clear warning about discarding const qualifier

[Ferruh Yigit]

On 6/1/2022 6:45 AM, Ke Zhang wrote:
> The warning info:
> warning: passing argument 1 of ‘memcpy’ discards ‘const’
> qualifier from pointer target type
> 
> Variable is done const intentionally to prevent using it
> directly, using the new helper functions :
> 'eth_hw_addr_set()' and 'eth_hw_addr_random()'
> 
> Fixes: ea6b39b5b847 ("kni: remove ethtool support")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Ke Zhang <ke1x.zhang@intel.com>
> ---
>   kernel/linux/kni/kni_misc.c | 4 ++--
>   kernel/linux/kni/kni_net.c  | 2 +-
>   2 files changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/kernel/linux/kni/kni_misc.c b/kernel/linux/kni/kni_misc.c
> index 780187d8bf..1da8e812b7 100644
> --- a/kernel/linux/kni/kni_misc.c
> +++ b/kernel/linux/kni/kni_misc.c
> @@ -403,10 +403,10 @@ 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);
> +		eth_hw_addr_set(net_dev, dev_info.mac_addr);
>   	else
>   		/* Generate random MAC address. */
> -		eth_random_addr(net_dev->dev_addr);
> +		eth_hw_addr_random(net_dev);
>   
>   	if (dev_info.mtu)
>   		net_dev->mtu = dev_info.mtu;
> diff --git a/kernel/linux/kni/kni_net.c b/kernel/linux/kni/kni_net.c
> index 29e5b9e21f..1da4f836aa 100644
> --- a/kernel/linux/kni/kni_net.c
> +++ b/kernel/linux/kni/kni_net.c
> @@ -779,7 +779,7 @@ kni_net_set_mac(struct net_device *netdev, void *p)
>   		return -EADDRNOTAVAIL;
>   
>   	memcpy(req.mac_addr, addr->sa_data, netdev->addr_len);
> -	memcpy(netdev->dev_addr, addr->sa_data, netdev->addr_len);
> +	eth_hw_addr_set(netdev, addr->sa_data);
>   
>   	ret = kni_net_process_request(netdev, &req);
>   

Hi Ke,

We can't just use new APIs, otherwise this will fail with old kernels.
A version check is needed, please check 'compat.h' for various samples.

[PATCH v3 1/2] kni: use dedicated function to set random MAC address

[Andrew Rybchenko]

eth_hw_addr_random() sets address type correctly.

eth_hw_addr_random() is available since Linux v3.4, so
no compat is required.

Also fix the warning:
warning: passing argument 1 of ‘memcpy’ discards ‘const’
qualifier from pointer target type

Variable dev_addr is done const intentionally in Linux v5.17 to
prevent using it directly.

Fixes: ea6b39b5b847 ("kni: remove ethtool support")
Cc: stable@dpdk.org

Signed-off-by: Ke Zhang <ke1x.zhang@intel.com>
Signed-off-by: Andrew Rybchenko <andrew.rybchenko@oktetlabs.ru>
---
 kernel/linux/kni/kni_misc.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/linux/kni/kni_misc.c b/kernel/linux/kni/kni_misc.c
index 780187d8bf..4f6dd373a3 100644
--- a/kernel/linux/kni/kni_misc.c
+++ b/kernel/linux/kni/kni_misc.c
@@ -405,8 +405,8 @@ kni_ioctl_create(struct net *net, uint32_t ioctl_num,
 	if (is_valid_ether_addr(dev_info.mac_addr))
 		memcpy(net_dev->dev_addr, dev_info.mac_addr, ETH_ALEN);
 	else
-		/* Generate random MAC address. */
-		eth_random_addr(net_dev->dev_addr);
+		/* Assign random MAC address. */
+		eth_hw_addr_random(net_dev);
 
 	if (dev_info.mtu)
 		net_dev->mtu = dev_info.mtu;
-- 
2.30.2

[PATCH v3 2/2] kni: fix warning about discarding const qualifier

[Andrew Rybchenko]

The warning info:
warning: passing argument 1 of ‘memcpy’ discards ‘const’
qualifier from pointer target type

Variable dev_addr is done const intentionally in v5.17 to prevent using
it directly. See kernel series [1] for more information.

[1] https://lore.kernel.org/netdev/YZYAb4X%2FVQFy0iks@shredder/T/

Fixes: ea6b39b5b847 ("kni: remove ethtool support")
Cc: stable@dpdk.org

Signed-off-by: Ke Zhang <ke1x.zhang@intel.com>
Signed-off-by: Andrew Rybchenko <andrew.rybchenko@oktetlabs.ru>
---
 kernel/linux/kni/compat.h   | 4 ++++
 kernel/linux/kni/kni_misc.c | 9 +++++++--
 kernel/linux/kni/kni_net.c  | 4 ++++
 3 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/kernel/linux/kni/compat.h b/kernel/linux/kni/compat.h
index 0db29a4a6f..2c8f346ddf 100644
--- a/kernel/linux/kni/compat.h
+++ b/kernel/linux/kni/compat.h
@@ -145,3 +145,7 @@
 #if KERNEL_VERSION(5, 18, 0) > LINUX_VERSION_CODE
 #define HAVE_NETIF_RX_NI
 #endif
+
+#if KERNEL_VERSION(5, 15, 0) <= LINUX_VERSION_CODE
+#define HAVE_ETH_HW_ADDR_SET
+#endif
diff --git a/kernel/linux/kni/kni_misc.c b/kernel/linux/kni/kni_misc.c
index 4f6dd373a3..0c3a86ee35 100644
--- a/kernel/linux/kni/kni_misc.c
+++ b/kernel/linux/kni/kni_misc.c
@@ -402,11 +402,16 @@ kni_ioctl_create(struct net *net, uint32_t ioctl_num,
 	pr_debug("mbuf_size:    %u\n", kni->mbuf_size);
 
 	/* if user has provided a valid mac address */
-	if (is_valid_ether_addr(dev_info.mac_addr))
+	if (is_valid_ether_addr(dev_info.mac_addr)) {
+#ifdef HAVE_ETH_HW_ADDR_SET
+		eth_hw_addr_set(net_dev, dev_info.mac_addr);
+#else
 		memcpy(net_dev->dev_addr, dev_info.mac_addr, ETH_ALEN);
-	else
+#endif
+	} else {
 		/* Assign random MAC address. */
 		eth_hw_addr_random(net_dev);
+	}
 
 	if (dev_info.mtu)
 		net_dev->mtu = dev_info.mtu;
diff --git a/kernel/linux/kni/kni_net.c b/kernel/linux/kni/kni_net.c
index a8b092b756..2da2029b0c 100644
--- a/kernel/linux/kni/kni_net.c
+++ b/kernel/linux/kni/kni_net.c
@@ -783,7 +783,11 @@ kni_net_set_mac(struct net_device *netdev, void *p)
 		return -EADDRNOTAVAIL;
 
 	memcpy(req.mac_addr, addr->sa_data, netdev->addr_len);
+#ifdef HAVE_ETH_HW_ADDR_SET
+	eth_hw_addr_set(net_dev, addr->sa_data);
+#else
 	memcpy(netdev->dev_addr, addr->sa_data, netdev->addr_len);
+#endif
 
 	ret = kni_net_process_request(netdev, &req);
 
-- 
2.30.2

[PATCH v4 1/2] kni: use dedicated function to set random MAC address

[Andrew Rybchenko]

From: Ke Zhang <ke1x.zhang@intel.com>

eth_hw_addr_random() sets address type correctly.

eth_hw_addr_random() is available since Linux v3.4, so
no compat is required.

Also fix the warning:
warning: passing argument 1 of ‘memcpy’ discards ‘const’
qualifier from pointer target type

Variable dev_addr is done const intentionally in Linux v5.17 to
prevent using it directly.

Fixes: ea6b39b5b847 ("kni: remove ethtool support")
Cc: stable@dpdk.org

Signed-off-by: Ke Zhang <ke1x.zhang@intel.com>
Signed-off-by: Andrew Rybchenko <andrew.rybchenko@oktetlabs.ru>
---
 kernel/linux/kni/kni_misc.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/linux/kni/kni_misc.c b/kernel/linux/kni/kni_misc.c
index 780187d8bf..4f6dd373a3 100644
--- a/kernel/linux/kni/kni_misc.c
+++ b/kernel/linux/kni/kni_misc.c
@@ -405,8 +405,8 @@ kni_ioctl_create(struct net *net, uint32_t ioctl_num,
 	if (is_valid_ether_addr(dev_info.mac_addr))
 		memcpy(net_dev->dev_addr, dev_info.mac_addr, ETH_ALEN);
 	else
-		/* Generate random MAC address. */
-		eth_random_addr(net_dev->dev_addr);
+		/* Assign random MAC address. */
+		eth_hw_addr_random(net_dev);
 
 	if (dev_info.mtu)
 		net_dev->mtu = dev_info.mtu;
-- 
2.30.2

[PATCH v4 2/2] kni: fix warning about discarding const qualifier

[Andrew Rybchenko]

From: Ke Zhang <ke1x.zhang@intel.com>

The warning info:
warning: passing argument 1 of ‘memcpy’ discards ‘const’
qualifier from pointer target type

Variable dev_addr is done const intentionally in v5.17 to prevent using
it directly. See kernel series [1] for more information.

[1] https://lore.kernel.org/netdev/YZYAb4X%2FVQFy0iks@shredder/T/

Fixes: ea6b39b5b847 ("kni: remove ethtool support")
Cc: stable@dpdk.org

Signed-off-by: Ke Zhang <ke1x.zhang@intel.com>
Signed-off-by: Andrew Rybchenko <andrew.rybchenko@oktetlabs.ru>
---
 kernel/linux/kni/compat.h   | 4 ++++
 kernel/linux/kni/kni_misc.c | 9 +++++++--
 kernel/linux/kni/kni_net.c  | 4 ++++
 3 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/kernel/linux/kni/compat.h b/kernel/linux/kni/compat.h
index 0db29a4a6f..2c8f346ddf 100644
--- a/kernel/linux/kni/compat.h
+++ b/kernel/linux/kni/compat.h
@@ -145,3 +145,7 @@
 #if KERNEL_VERSION(5, 18, 0) > LINUX_VERSION_CODE
 #define HAVE_NETIF_RX_NI
 #endif
+
+#if KERNEL_VERSION(5, 15, 0) <= LINUX_VERSION_CODE
+#define HAVE_ETH_HW_ADDR_SET
+#endif
diff --git a/kernel/linux/kni/kni_misc.c b/kernel/linux/kni/kni_misc.c
index 4f6dd373a3..0c3a86ee35 100644
--- a/kernel/linux/kni/kni_misc.c
+++ b/kernel/linux/kni/kni_misc.c
@@ -402,11 +402,16 @@ kni_ioctl_create(struct net *net, uint32_t ioctl_num,
 	pr_debug("mbuf_size:    %u\n", kni->mbuf_size);
 
 	/* if user has provided a valid mac address */
-	if (is_valid_ether_addr(dev_info.mac_addr))
+	if (is_valid_ether_addr(dev_info.mac_addr)) {
+#ifdef HAVE_ETH_HW_ADDR_SET
+		eth_hw_addr_set(net_dev, dev_info.mac_addr);
+#else
 		memcpy(net_dev->dev_addr, dev_info.mac_addr, ETH_ALEN);
-	else
+#endif
+	} else {
 		/* Assign random MAC address. */
 		eth_hw_addr_random(net_dev);
+	}
 
 	if (dev_info.mtu)
 		net_dev->mtu = dev_info.mtu;
diff --git a/kernel/linux/kni/kni_net.c b/kernel/linux/kni/kni_net.c
index 41805fcabf..6257dcb1a8 100644
--- a/kernel/linux/kni/kni_net.c
+++ b/kernel/linux/kni/kni_net.c
@@ -783,7 +783,11 @@ kni_net_set_mac(struct net_device *netdev, void *p)
 		return -EADDRNOTAVAIL;
 
 	memcpy(req.mac_addr, addr->sa_data, netdev->addr_len);
+#ifdef HAVE_ETH_HW_ADDR_SET
+	eth_hw_addr_set(net_dev, addr->sa_data);
+#else
 	memcpy(netdev->dev_addr, addr->sa_data, netdev->addr_len);
+#endif
 
 	ret = kni_net_process_request(netdev, &req);
 
-- 
2.30.2

[PATCH v5 1/2] kni: use dedicated function to set random MAC address

[Andrew Rybchenko]

From: Ke Zhang <ke1x.zhang@intel.com>

eth_hw_addr_random() sets address type correctly.

eth_hw_addr_random() is available since Linux v3.4, so
no compat is required.

Also fix the warning:
warning: passing argument 1 of ‘memcpy’ discards ‘const’
qualifier from pointer target type

Variable dev_addr is done const intentionally in Linux v5.17 to
prevent using it directly.

Fixes: ea6b39b5b847 ("kni: remove ethtool support")
Cc: stable@dpdk.org

Signed-off-by: Ke Zhang <ke1x.zhang@intel.com>
Signed-off-by: Andrew Rybchenko <andrew.rybchenko@oktetlabs.ru>
---
 kernel/linux/kni/kni_misc.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/linux/kni/kni_misc.c b/kernel/linux/kni/kni_misc.c
index 780187d8bf..4f6dd373a3 100644
--- a/kernel/linux/kni/kni_misc.c
+++ b/kernel/linux/kni/kni_misc.c
@@ -405,8 +405,8 @@ kni_ioctl_create(struct net *net, uint32_t ioctl_num,
 	if (is_valid_ether_addr(dev_info.mac_addr))
 		memcpy(net_dev->dev_addr, dev_info.mac_addr, ETH_ALEN);
 	else
-		/* Generate random MAC address. */
-		eth_random_addr(net_dev->dev_addr);
+		/* Assign random MAC address. */
+		eth_hw_addr_random(net_dev);
 
 	if (dev_info.mtu)
 		net_dev->mtu = dev_info.mtu;
-- 
2.30.2

[PATCH v5 2/2] kni: fix warning about discarding const qualifier

[Andrew Rybchenko]

From: Ke Zhang <ke1x.zhang@intel.com>

The warning info:
warning: passing argument 1 of ‘memcpy’ discards ‘const’
qualifier from pointer target type

Variable dev_addr is done const intentionally in v5.17 to prevent using
it directly. See kernel series [1] for more information.

[1] https://lore.kernel.org/netdev/YZYAb4X%2FVQFy0iks@shredder/T/

Fixes: ea6b39b5b847 ("kni: remove ethtool support")
Cc: stable@dpdk.org

Signed-off-by: Ke Zhang <ke1x.zhang@intel.com>
Signed-off-by: Andrew Rybchenko <andrew.rybchenko@oktetlabs.ru>
---
 kernel/linux/kni/compat.h   | 4 ++++
 kernel/linux/kni/kni_misc.c | 9 +++++++--
 kernel/linux/kni/kni_net.c  | 4 ++++
 3 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/kernel/linux/kni/compat.h b/kernel/linux/kni/compat.h
index 0db29a4a6f..2c8f346ddf 100644
--- a/kernel/linux/kni/compat.h
+++ b/kernel/linux/kni/compat.h
@@ -145,3 +145,7 @@
 #if KERNEL_VERSION(5, 18, 0) > LINUX_VERSION_CODE
 #define HAVE_NETIF_RX_NI
 #endif
+
+#if KERNEL_VERSION(5, 15, 0) <= LINUX_VERSION_CODE
+#define HAVE_ETH_HW_ADDR_SET
+#endif
diff --git a/kernel/linux/kni/kni_misc.c b/kernel/linux/kni/kni_misc.c
index 4f6dd373a3..0c3a86ee35 100644
--- a/kernel/linux/kni/kni_misc.c
+++ b/kernel/linux/kni/kni_misc.c
@@ -402,11 +402,16 @@ kni_ioctl_create(struct net *net, uint32_t ioctl_num,
 	pr_debug("mbuf_size:    %u\n", kni->mbuf_size);
 
 	/* if user has provided a valid mac address */
-	if (is_valid_ether_addr(dev_info.mac_addr))
+	if (is_valid_ether_addr(dev_info.mac_addr)) {
+#ifdef HAVE_ETH_HW_ADDR_SET
+		eth_hw_addr_set(net_dev, dev_info.mac_addr);
+#else
 		memcpy(net_dev->dev_addr, dev_info.mac_addr, ETH_ALEN);
-	else
+#endif
+	} else {
 		/* Assign random MAC address. */
 		eth_hw_addr_random(net_dev);
+	}
 
 	if (dev_info.mtu)
 		net_dev->mtu = dev_info.mtu;
diff --git a/kernel/linux/kni/kni_net.c b/kernel/linux/kni/kni_net.c
index 41805fcabf..779ee3451a 100644
--- a/kernel/linux/kni/kni_net.c
+++ b/kernel/linux/kni/kni_net.c
@@ -783,7 +783,11 @@ kni_net_set_mac(struct net_device *netdev, void *p)
 		return -EADDRNOTAVAIL;
 
 	memcpy(req.mac_addr, addr->sa_data, netdev->addr_len);
+#ifdef HAVE_ETH_HW_ADDR_SET
+	eth_hw_addr_set(netdev, addr->sa_data);
+#else
 	memcpy(netdev->dev_addr, addr->sa_data, netdev->addr_len);
+#endif
 
 	ret = kni_net_process_request(netdev, &req);
 
-- 
2.30.2

Re: [PATCH v5 1/2] kni: use dedicated function to set random MAC address

[Ferruh Yigit]

On 6/8/2022 1:11 PM, Andrew Rybchenko wrote:
> From: Ke Zhang <ke1x.zhang@intel.com>
> 
> eth_hw_addr_random() sets address type correctly.
> 
> eth_hw_addr_random() is available since Linux v3.4, so
> no compat is required.
> 
> Also fix the warning:
> warning: passing argument 1 of ‘memcpy’ discards ‘const’
> qualifier from pointer target type
> 
> Variable dev_addr is done const intentionally in Linux v5.17 to
> prevent using it directly.
> 
> Fixes: ea6b39b5b847 ("kni: remove ethtool support")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Ke Zhang <ke1x.zhang@intel.com>
> Signed-off-by: Andrew Rybchenko <andrew.rybchenko@oktetlabs.ru>

Acked-by: Ferruh Yigit <ferruh.yigit@xilinx.com>

Re: [PATCH v5 2/2] kni: fix warning about discarding const qualifier

[Ferruh Yigit]

On 6/8/2022 1:11 PM, Andrew Rybchenko wrote:

> 
> From: Ke Zhang <ke1x.zhang@intel.com>
> 
> The warning info:
> warning: passing argument 1 of ‘memcpy’ discards ‘const’
> qualifier from pointer target type
> 
> Variable dev_addr is done const intentionally in v5.17 to prevent using
> it directly. See kernel series [1] for more information.
> 
> [1] https://lore.kernel.org/netdev/YZYAb4X%2FVQFy0iks@shredder/T/

Can you add Linux kernel commit log, instead of the mail list archive? 
This helps to check the relevant code change in kernel easier, and 
verify in which versions it exists etc..

> 
> Fixes: ea6b39b5b847 ("kni: remove ethtool support")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Ke Zhang <ke1x.zhang@intel.com>
> Signed-off-by: Andrew Rybchenko <andrew.rybchenko@oktetlabs.ru>

Acked-by: Ferruh Yigit <ferruh.yigit@xilinx.com>

Re: [PATCH v5 2/2] kni: fix warning about discarding const qualifier

[Ferruh Yigit]

On 6/8/2022 1:54 PM, Ferruh Yigit wrote:
> On 6/8/2022 1:11 PM, Andrew Rybchenko wrote:
> 
>>
>> From: Ke Zhang <ke1x.zhang@intel.com>
>>
>> The warning info:
>> warning: passing argument 1 of ‘memcpy’ discards ‘const’
>> qualifier from pointer target type
>>
>> Variable dev_addr is done const intentionally in v5.17 to prevent using
>> it directly. See kernel series [1] for more information.

`dev_addr` is done const in v5.17,
but patch checks >= v5.15 because used helpers introduced in v5.15, 
should this be clarified to not confuse users? No strong opinion from me.

>>
>> [1] https://lore.kernel.org/netdev/YZYAb4X%2FVQFy0iks@shredder/T/
> 
> Can you add Linux kernel commit log, instead of the mail list archive? 
> This helps to check the relevant code change in kernel easier, and 
> verify in which versions it exists etc..
> 

I think mentioned commit is following
Commit adeef3e32146 ("net: constify netdev->dev_addr")

>>
>> Fixes: ea6b39b5b847 ("kni: remove ethtool support")
>> Cc: stable@dpdk.org
>>
>> Signed-off-by: Ke Zhang <ke1x.zhang@intel.com>
>> Signed-off-by: Andrew Rybchenko <andrew.rybchenko@oktetlabs.ru>
> 
> Acked-by: Ferruh Yigit <ferruh.yigit@xilinx.com>
>