[PATCH 0/5] net: use vmalloc_array() to simplify code

[PATCH 0/5] net: use vmalloc_array() to simplify code

[Qianfeng Rong]

Remove array_size() calls and replace vmalloc() with vmalloc_array() to
simplify the code and maintain consistency with existing kmalloc_array()
usage.

Compile-tested only.

Qianfeng Rong (5):
  ethtool: use vmalloc_array() to simplify code
  nfp: flower: use vmalloc_array() to simplify code
  ppp: use vmalloc_array() to simplify
  wifi: ath5k: use vmalloc_array() to simplify code
  wifi: mwifiex: use vmalloc_array() to simplify code

 drivers/net/ethernet/intel/fm10k/fm10k_ethtool.c     | 2 +-
 drivers/net/ethernet/intel/igb/igb_ethtool.c         | 8 ++++----
 drivers/net/ethernet/intel/igc/igc_ethtool.c         | 8 ++++----
 drivers/net/ethernet/intel/ixgbe/ixgbe_ethtool.c     | 2 +-
 drivers/net/ethernet/intel/ixgbevf/ethtool.c         | 6 +++---
 drivers/net/ethernet/netronome/nfp/flower/metadata.c | 4 ++--
 drivers/net/ppp/bsd_comp.c                           | 4 ++--
 drivers/net/wireless/ath/ath5k/debug.c               | 2 +-
 drivers/net/wireless/marvell/mwifiex/cfg80211.c      | 4 ++--
 9 files changed, 20 insertions(+), 20 deletions(-)

-- 
2.34.1

[PATCH 1/5] ethtool: use vmalloc_array() to simplify code

[Qianfeng Rong]

Remove array_size() calls and replace vmalloc() with vmalloc_array() to
simplify the code and maintain consistency with existing kmalloc_array()
usage.

Signed-off-by: Qianfeng Rong <rongqianfeng@vivo.com>
---
 drivers/net/ethernet/intel/fm10k/fm10k_ethtool.c | 2 +-
 drivers/net/ethernet/intel/igb/igb_ethtool.c     | 8 ++++----
 drivers/net/ethernet/intel/igc/igc_ethtool.c     | 8 ++++----
 drivers/net/ethernet/intel/ixgbe/ixgbe_ethtool.c | 2 +-
 drivers/net/ethernet/intel/ixgbevf/ethtool.c     | 6 +++---
 5 files changed, 13 insertions(+), 13 deletions(-)

diff --git a/drivers/net/ethernet/intel/fm10k/fm10k_ethtool.c b/drivers/net/ethernet/intel/fm10k/fm10k_ethtool.c
index 1954a04460d1..bf2029144c1d 100644
--- a/drivers/net/ethernet/intel/fm10k/fm10k_ethtool.c
+++ b/drivers/net/ethernet/intel/fm10k/fm10k_ethtool.c
@@ -560,7 +560,7 @@ static int fm10k_set_ringparam(struct net_device *netdev,
 
 	/* allocate temporary buffer to store rings in */
 	i = max_t(int, interface->num_tx_queues, interface->num_rx_queues);
-	temp_ring = vmalloc(array_size(i, sizeof(struct fm10k_ring)));
+	temp_ring = vmalloc_array(i, sizeof(struct fm10k_ring));
 
 	if (!temp_ring) {
 		err = -ENOMEM;
diff --git a/drivers/net/ethernet/intel/igb/igb_ethtool.c b/drivers/net/ethernet/intel/igb/igb_ethtool.c
index 92ef33459aec..51d5cb6599ed 100644
--- a/drivers/net/ethernet/intel/igb/igb_ethtool.c
+++ b/drivers/net/ethernet/intel/igb/igb_ethtool.c
@@ -920,11 +920,11 @@ static int igb_set_ringparam(struct net_device *netdev,
 	}
 
 	if (adapter->num_tx_queues > adapter->num_rx_queues)
-		temp_ring = vmalloc(array_size(sizeof(struct igb_ring),
-					       adapter->num_tx_queues));
+		temp_ring = vmalloc_array(adapter->num_tx_queues,
+					  sizeof(struct igb_ring));
 	else
-		temp_ring = vmalloc(array_size(sizeof(struct igb_ring),
-					       adapter->num_rx_queues));
+		temp_ring = vmalloc_array(adapter->num_rx_queues,
+					  sizeof(struct igb_ring));
 
 	if (!temp_ring) {
 		err = -ENOMEM;
diff --git a/drivers/net/ethernet/intel/igc/igc_ethtool.c b/drivers/net/ethernet/intel/igc/igc_ethtool.c
index ecb35b693ce5..f3e7218ba6f3 100644
--- a/drivers/net/ethernet/intel/igc/igc_ethtool.c
+++ b/drivers/net/ethernet/intel/igc/igc_ethtool.c
@@ -627,11 +627,11 @@ igc_ethtool_set_ringparam(struct net_device *netdev,
 	}
 
 	if (adapter->num_tx_queues > adapter->num_rx_queues)
-		temp_ring = vmalloc(array_size(sizeof(struct igc_ring),
-					       adapter->num_tx_queues));
+		temp_ring = vmalloc_array(adapter->num_tx_queues,
+					  sizeof(struct igc_ring));
 	else
-		temp_ring = vmalloc(array_size(sizeof(struct igc_ring),
-					       adapter->num_rx_queues));
+		temp_ring = vmalloc_array(adapter->num_rx_queues,
+					  sizeof(struct igc_ring));
 
 	if (!temp_ring) {
 		err = -ENOMEM;
diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_ethtool.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_ethtool.c
index 25c3a09ad7f1..2c5d774f1ec1 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_ethtool.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_ethtool.c
@@ -1278,7 +1278,7 @@ static int ixgbe_set_ringparam(struct net_device *netdev,
 	/* allocate temporary buffer to store rings in */
 	i = max_t(int, adapter->num_tx_queues + adapter->num_xdp_queues,
 		  adapter->num_rx_queues);
-	temp_ring = vmalloc(array_size(i, sizeof(struct ixgbe_ring)));
+	temp_ring = vmalloc_array(i, sizeof(struct ixgbe_ring));
 
 	if (!temp_ring) {
 		err = -ENOMEM;
diff --git a/drivers/net/ethernet/intel/ixgbevf/ethtool.c b/drivers/net/ethernet/intel/ixgbevf/ethtool.c
index 7ac53171b041..bebad564188e 100644
--- a/drivers/net/ethernet/intel/ixgbevf/ethtool.c
+++ b/drivers/net/ethernet/intel/ixgbevf/ethtool.c
@@ -276,9 +276,9 @@ static int ixgbevf_set_ringparam(struct net_device *netdev,
 	}
 
 	if (new_tx_count != adapter->tx_ring_count) {
-		tx_ring = vmalloc(array_size(sizeof(*tx_ring),
-					     adapter->num_tx_queues +
-						adapter->num_xdp_queues));
+		tx_ring = vmalloc_array(adapter->num_tx_queues +
+					adapter->num_xdp_queues,
+					sizeof(*tx_ring));
 		if (!tx_ring) {
 			err = -ENOMEM;
 			goto clear_reset;
-- 
2.34.1

RE: [Intel-wired-lan] [PATCH 1/5] ethtool: use vmalloc_array() to simplify code

[Loktionov, Aleksandr]

> -----Original Message-----
> From: Intel-wired-lan <intel-wired-lan-bounces@osuosl.org> On Behalf
> Of Qianfeng Rong
> Sent: Tuesday, August 12, 2025 3:32 PM
> To: Nguyen, Anthony L <anthony.l.nguyen@intel.com>; Kitszel,
> Przemyslaw <przemyslaw.kitszel@intel.com>; Andrew Lunn
> <andrew+netdev@lunn.ch>; David S. Miller <davem@davemloft.net>; Eric
> Dumazet <edumazet@google.com>; Jakub Kicinski <kuba@kernel.org>; Paolo
> Abeni <pabeni@redhat.com>; Alexei Starovoitov <ast@kernel.org>; Daniel
> Borkmann <daniel@iogearbox.net>; Jesper Dangaard Brouer
> <hawk@kernel.org>; John Fastabend <john.fastabend@gmail.com>;
> Stanislav Fomichev <sdf@fomichev.me>; moderated list:INTEL ETHERNET
> DRIVERS <intel-wired-lan@lists.osuosl.org>; open list:NETWORKING
> DRIVERS <netdev@vger.kernel.org>; open list <linux-
> kernel@vger.kernel.org>; open list:XDP (eXpress Data
> Path):Keyword:(?:\b|_)xdp(?:\b|_) <bpf@vger.kernel.org>
> Cc: Qianfeng Rong <rongqianfeng@vivo.com>
> Subject: [Intel-wired-lan] [PATCH 1/5] ethtool: use vmalloc_array() to
> simplify code
> 
> Remove array_size() calls and replace vmalloc() with vmalloc_array()
> to simplify the code and maintain consistency with existing
> kmalloc_array() usage.
> 
> Signed-off-by: Qianfeng Rong <rongqianfeng@vivo.com>

Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>
> ---
>  drivers/net/ethernet/intel/fm10k/fm10k_ethtool.c | 2 +-
>  drivers/net/ethernet/intel/igb/igb_ethtool.c     | 8 ++++----
>  drivers/net/ethernet/intel/igc/igc_ethtool.c     | 8 ++++----
>  drivers/net/ethernet/intel/ixgbe/ixgbe_ethtool.c | 2 +-
>  drivers/net/ethernet/intel/ixgbevf/ethtool.c     | 6 +++---
>  5 files changed, 13 insertions(+), 13 deletions(-)
> 
> diff --git a/drivers/net/ethernet/intel/fm10k/fm10k_ethtool.c
> b/drivers/net/ethernet/intel/fm10k/fm10k_ethtool.c
> index 1954a04460d1..bf2029144c1d 100644
> --- a/drivers/net/ethernet/intel/fm10k/fm10k_ethtool.c
> +++ b/drivers/net/ethernet/intel/fm10k/fm10k_ethtool.c
> @@ -560,7 +560,7 @@ static int fm10k_set_ringparam(struct net_device
> *netdev,
> 
>  	/* allocate temporary buffer to store rings in */
>  	i = max_t(int, interface->num_tx_queues, interface-
> >num_rx_queues);
> -	temp_ring = vmalloc(array_size(i, sizeof(struct fm10k_ring)));
> +	temp_ring = vmalloc_array(i, sizeof(struct fm10k_ring));
> 
>  	if (!temp_ring) {
>  		err = -ENOMEM;
> diff --git a/drivers/net/ethernet/intel/igb/igb_ethtool.c
> b/drivers/net/ethernet/intel/igb/igb_ethtool.c
> index 92ef33459aec..51d5cb6599ed 100644
> --- a/drivers/net/ethernet/intel/igb/igb_ethtool.c
> +++ b/drivers/net/ethernet/intel/igb/igb_ethtool.c
> @@ -920,11 +920,11 @@ static int igb_set_ringparam(struct net_device
> *netdev,
>  	}
> 
>  	if (adapter->num_tx_queues > adapter->num_rx_queues)
> -		temp_ring = vmalloc(array_size(sizeof(struct igb_ring),
> -					       adapter->num_tx_queues));
> +		temp_ring = vmalloc_array(adapter->num_tx_queues,
> +					  sizeof(struct igb_ring));
>  	else
> -		temp_ring = vmalloc(array_size(sizeof(struct igb_ring),
> -					       adapter->num_rx_queues));
> +		temp_ring = vmalloc_array(adapter->num_rx_queues,
> +					  sizeof(struct igb_ring));
> 
>  	if (!temp_ring) {
>  		err = -ENOMEM;
> diff --git a/drivers/net/ethernet/intel/igc/igc_ethtool.c
> b/drivers/net/ethernet/intel/igc/igc_ethtool.c
> index ecb35b693ce5..f3e7218ba6f3 100644
> --- a/drivers/net/ethernet/intel/igc/igc_ethtool.c
> +++ b/drivers/net/ethernet/intel/igc/igc_ethtool.c
> @@ -627,11 +627,11 @@ igc_ethtool_set_ringparam(struct net_device
> *netdev,
>  	}
> 
>  	if (adapter->num_tx_queues > adapter->num_rx_queues)
> -		temp_ring = vmalloc(array_size(sizeof(struct igc_ring),
> -					       adapter->num_tx_queues));
> +		temp_ring = vmalloc_array(adapter->num_tx_queues,
> +					  sizeof(struct igc_ring));
>  	else
> -		temp_ring = vmalloc(array_size(sizeof(struct igc_ring),
> -					       adapter->num_rx_queues));
> +		temp_ring = vmalloc_array(adapter->num_rx_queues,
> +					  sizeof(struct igc_ring));
> 
>  	if (!temp_ring) {
>  		err = -ENOMEM;
> diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_ethtool.c
> b/drivers/net/ethernet/intel/ixgbe/ixgbe_ethtool.c
> index 25c3a09ad7f1..2c5d774f1ec1 100644
> --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_ethtool.c
> +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_ethtool.c
> @@ -1278,7 +1278,7 @@ static int ixgbe_set_ringparam(struct net_device
> *netdev,
>  	/* allocate temporary buffer to store rings in */
>  	i = max_t(int, adapter->num_tx_queues + adapter-
> >num_xdp_queues,
>  		  adapter->num_rx_queues);
> -	temp_ring = vmalloc(array_size(i, sizeof(struct ixgbe_ring)));
> +	temp_ring = vmalloc_array(i, sizeof(struct ixgbe_ring));
> 
>  	if (!temp_ring) {
>  		err = -ENOMEM;
> diff --git a/drivers/net/ethernet/intel/ixgbevf/ethtool.c
> b/drivers/net/ethernet/intel/ixgbevf/ethtool.c
> index 7ac53171b041..bebad564188e 100644
> --- a/drivers/net/ethernet/intel/ixgbevf/ethtool.c
> +++ b/drivers/net/ethernet/intel/ixgbevf/ethtool.c
> @@ -276,9 +276,9 @@ static int ixgbevf_set_ringparam(struct net_device
> *netdev,
>  	}
> 
>  	if (new_tx_count != adapter->tx_ring_count) {
> -		tx_ring = vmalloc(array_size(sizeof(*tx_ring),
> -					     adapter->num_tx_queues +
> -						adapter->num_xdp_queues));
> +		tx_ring = vmalloc_array(adapter->num_tx_queues +
> +					adapter->num_xdp_queues,
> +					sizeof(*tx_ring));
>  		if (!tx_ring) {
>  			err = -ENOMEM;
>  			goto clear_reset;
> --
> 2.34.1

Re: [Intel-wired-lan] [PATCH 1/5] ethtool: use vmalloc_array() to simplify code

[Paul Menzel]

Dear Qianfeng,


Thank you for your patch.

Am 12.08.25 um 15:32 schrieb Qianfeng Rong:
> Remove array_size() calls and replace vmalloc() with vmalloc_array() to
> simplify the code and maintain consistency with existing kmalloc_array()
> usage.

You could build it without and with your patch and look if the assembler 
code changes.

> Signed-off-by: Qianfeng Rong <rongqianfeng@vivo.com>
> ---
>   drivers/net/ethernet/intel/fm10k/fm10k_ethtool.c | 2 +-
>   drivers/net/ethernet/intel/igb/igb_ethtool.c     | 8 ++++----
>   drivers/net/ethernet/intel/igc/igc_ethtool.c     | 8 ++++----
>   drivers/net/ethernet/intel/ixgbe/ixgbe_ethtool.c | 2 +-
>   drivers/net/ethernet/intel/ixgbevf/ethtool.c     | 6 +++---
>   5 files changed, 13 insertions(+), 13 deletions(-)
> 
> diff --git a/drivers/net/ethernet/intel/fm10k/fm10k_ethtool.c b/drivers/net/ethernet/intel/fm10k/fm10k_ethtool.c
> index 1954a04460d1..bf2029144c1d 100644
> --- a/drivers/net/ethernet/intel/fm10k/fm10k_ethtool.c
> +++ b/drivers/net/ethernet/intel/fm10k/fm10k_ethtool.c
> @@ -560,7 +560,7 @@ static int fm10k_set_ringparam(struct net_device *netdev,
>   
>   	/* allocate temporary buffer to store rings in */
>   	i = max_t(int, interface->num_tx_queues, interface->num_rx_queues);
> -	temp_ring = vmalloc(array_size(i, sizeof(struct fm10k_ring)));
> +	temp_ring = vmalloc_array(i, sizeof(struct fm10k_ring));
>   
>   	if (!temp_ring) {
>   		err = -ENOMEM;
> diff --git a/drivers/net/ethernet/intel/igb/igb_ethtool.c b/drivers/net/ethernet/intel/igb/igb_ethtool.c
> index 92ef33459aec..51d5cb6599ed 100644
> --- a/drivers/net/ethernet/intel/igb/igb_ethtool.c
> +++ b/drivers/net/ethernet/intel/igb/igb_ethtool.c
> @@ -920,11 +920,11 @@ static int igb_set_ringparam(struct net_device *netdev,
>   	}
>   
>   	if (adapter->num_tx_queues > adapter->num_rx_queues)
> -		temp_ring = vmalloc(array_size(sizeof(struct igb_ring),
> -					       adapter->num_tx_queues));
> +		temp_ring = vmalloc_array(adapter->num_tx_queues,
> +					  sizeof(struct igb_ring));
>   	else
> -		temp_ring = vmalloc(array_size(sizeof(struct igb_ring),
> -					       adapter->num_rx_queues));
> +		temp_ring = vmalloc_array(adapter->num_rx_queues,
> +					  sizeof(struct igb_ring));
>   
>   	if (!temp_ring) {
>   		err = -ENOMEM;
> diff --git a/drivers/net/ethernet/intel/igc/igc_ethtool.c b/drivers/net/ethernet/intel/igc/igc_ethtool.c
> index ecb35b693ce5..f3e7218ba6f3 100644
> --- a/drivers/net/ethernet/intel/igc/igc_ethtool.c
> +++ b/drivers/net/ethernet/intel/igc/igc_ethtool.c
> @@ -627,11 +627,11 @@ igc_ethtool_set_ringparam(struct net_device *netdev,
>   	}
>   
>   	if (adapter->num_tx_queues > adapter->num_rx_queues)
> -		temp_ring = vmalloc(array_size(sizeof(struct igc_ring),
> -					       adapter->num_tx_queues));
> +		temp_ring = vmalloc_array(adapter->num_tx_queues,
> +					  sizeof(struct igc_ring));
>   	else
> -		temp_ring = vmalloc(array_size(sizeof(struct igc_ring),
> -					       adapter->num_rx_queues));
> +		temp_ring = vmalloc_array(adapter->num_rx_queues,
> +					  sizeof(struct igc_ring));
>   
>   	if (!temp_ring) {
>   		err = -ENOMEM;
> diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_ethtool.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_ethtool.c
> index 25c3a09ad7f1..2c5d774f1ec1 100644
> --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_ethtool.c
> +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_ethtool.c
> @@ -1278,7 +1278,7 @@ static int ixgbe_set_ringparam(struct net_device *netdev,
>   	/* allocate temporary buffer to store rings in */
>   	i = max_t(int, adapter->num_tx_queues + adapter->num_xdp_queues,
>   		  adapter->num_rx_queues);
> -	temp_ring = vmalloc(array_size(i, sizeof(struct ixgbe_ring)));
> +	temp_ring = vmalloc_array(i, sizeof(struct ixgbe_ring));
>   
>   	if (!temp_ring) {
>   		err = -ENOMEM;
> diff --git a/drivers/net/ethernet/intel/ixgbevf/ethtool.c b/drivers/net/ethernet/intel/ixgbevf/ethtool.c
> index 7ac53171b041..bebad564188e 100644
> --- a/drivers/net/ethernet/intel/ixgbevf/ethtool.c
> +++ b/drivers/net/ethernet/intel/ixgbevf/ethtool.c
> @@ -276,9 +276,9 @@ static int ixgbevf_set_ringparam(struct net_device *netdev,
>   	}
>   
>   	if (new_tx_count != adapter->tx_ring_count) {
> -		tx_ring = vmalloc(array_size(sizeof(*tx_ring),
> -					     adapter->num_tx_queues +
> -						adapter->num_xdp_queues));
> +		tx_ring = vmalloc_array(adapter->num_tx_queues +
> +					adapter->num_xdp_queues,
> +					sizeof(*tx_ring));
>   		if (!tx_ring) {
>   			err = -ENOMEM;
>   			goto clear_reset;

Reviewed-by: Paul Menzel <pmenzel@molgen.mpg.de>


Kind regards,

Paul

Re: [PATCH 0/5] net: use vmalloc_array() to simplify code

[Jakub Kicinski]

On Tue, 12 Aug 2025 21:32:13 +0800 Qianfeng Rong wrote:
> Remove array_size() calls and replace vmalloc() with vmalloc_array() to
> simplify the code and maintain consistency with existing kmalloc_array()
> usage.

You need to submit the first 3 as a separate series.
They get applied to a different tree than wireless patches.

Re: [PATCH 1/5] ethtool: use vmalloc_array() to simplify code

[Jakub Kicinski]

On Tue, 12 Aug 2025 21:32:14 +0800 Qianfeng Rong wrote:
> Subject: [PATCH 1/5] ethtool: use vmalloc_array() to simplify code

ethtool:

would make sense for patches which touch net/ethtool.
Please use 

	eth: intel:

as the subject prefix.

Re: [PATCH 0/5] net: use vmalloc_array() to simplify code

[Qianfeng Rong]

在 2025/8/13 4:48, Jakub Kicinski 写道:
> On Tue, 12 Aug 2025 21:32:13 +0800 Qianfeng Rong wrote:
>> Remove array_size() calls and replace vmalloc() with vmalloc_array() to
>> simplify the code and maintain consistency with existing kmalloc_array()
>> usage.
> You need to submit the first 3 as a separate series.
> They get applied to a different tree than wireless patches.
Ok, Will do in the next version.

Re: [PATCH 0/5] net: use vmalloc_array() to simplify code

[Qianfeng Rong]

在 2025/8/13 4:48, Jakub Kicinski 写道:
> On Tue, 12 Aug 2025 21:32:13 +0800 Qianfeng Rong wrote:
>> Remove array_size() calls and replace vmalloc() with vmalloc_array() to
>> simplify the code and maintain consistency with existing kmalloc_array()
>> usage.
> You need to submit the first 3 as a separate series.
> They get applied to a different tree than wireless patches.

Ok，Will do in the next version.

Best regards,
Qianfeng

Re: [PATCH 1/5] ethtool: use vmalloc_array() to simplify code

[Qianfeng Rong]

在 2025/8/13 4:49, Jakub Kicinski 写道:
> On Tue, 12 Aug 2025 21:32:14 +0800 Qianfeng Rong wrote:
>> Subject: [PATCH 1/5] ethtool: use vmalloc_array() to simplify code
> ethtool:
>
> would make sense for patches which touch net/ethtool.
> Please use
>
> 	eth: intel:
>
> as the subject prefix.

Got it. Will do in the next version.

Best regards,
Qianfeng

Re: [Intel-wired-lan] [PATCH 1/5] ethtool: use vmalloc_array() to simplify code

[Qianfeng Rong]

在 2025/8/13 0:34, Paul Menzel 写道:
> [You don't often get email from pmenzel@molgen.mpg.de. Learn why this 
> is important at https://aka.ms/LearnAboutSenderIdentification ]
>
> Dear Qianfeng,
>
>
> Thank you for your patch.
>
> Am 12.08.25 um 15:32 schrieb Qianfeng Rong:
>> Remove array_size() calls and replace vmalloc() with vmalloc_array() to
>> simplify the code and maintain consistency with existing kmalloc_array()
>> usage.
>
> You could build it without and with your patch and look if the assembler
> code changes.
>

Very good point, the following experiment was done:
//before apply patch:
objdump -dSl --prefix-addresses fm10k_ethtool.o > original.dis

//after apply patch:
objdump -dSl --prefix-addresses fm10k_ethtool.o > patched.dis

diff -u original.dis patched.dis | diffstat
patched.dis | 1578 ... 1 file changed, 785 insertions(+), 793 deletions(-)

 From the above results, we can see that the assembly instructions are
reduced after applying the patch.


#define array_size(a, b)    size_mul(a, b)

static inline size_t __must_check size_mul(size_t factor1, size_t factor2)
{
     size_t bytes;

     if (check_mul_overflow(factor1, factor2, &bytes))
         return SIZE_MAX;

     return bytes;
}

void *__vmalloc_array_noprof(size_t n, size_t size, gfp_t flags)
{
     size_t bytes;

     if (unlikely(check_mul_overflow(n, size, &bytes)))
         return NULL;
     return __vmalloc_noprof(bytes, flags);
}

And from the code, array_size() will return SIZE_MAX after detecting
overflow.  SIZE_MAX is passed to vmalloc for available memory
verification before exiting and returning NULL. vmalloc_array()
will directly return NULL after detecting overflow.

Best regards,
Qianfeng
> Reviewed-by: Paul Menzel <pmenzel@molgen.mpg.de>
>
>
> Kind regards,
>
> Paul

Re: [Intel-wired-lan] [PATCH 1/5] ethtool: use vmalloc_array() to simplify code

[Paul Menzel]

Dear Quianfeng,


Thank you very much for your reply.

Am 14.08.25 um 06:05 schrieb Qianfeng Rong:
> 
> 在 2025/8/13 0:34, Paul Menzel 写道:

[…]

>> Am 12.08.25 um 15:32 schrieb Qianfeng Rong:
>>> Remove array_size() calls and replace vmalloc() with vmalloc_array() to
>>> simplify the code and maintain consistency with existing kmalloc_array()
>>> usage.
>>
>> You could build it without and with your patch and look if the assembler
>> code changes.
> 
> Very good point, the following experiment was done:
> //before apply patch:
> objdump -dSl --prefix-addresses fm10k_ethtool.o > original.dis
> 
> //after apply patch:
> objdump -dSl --prefix-addresses fm10k_ethtool.o > patched.dis
> 
> diff -u original.dis patched.dis | diffstat
> patched.dis | 1578 ... 1 file changed, 785 insertions(+), 793 deletions(-)
> 
> From the above results, we can see that the assembly instructions are
> reduced after applying the patch.
> 
> 
> #define array_size(a, b)    size_mul(a, b)
> 
> static inline size_t __must_check size_mul(size_t factor1, size_t factor2)
> {
>      size_t bytes;
> 
>      if (check_mul_overflow(factor1, factor2, &bytes))
>          return SIZE_MAX;
> 
>      return bytes;
> }
> 
> void *__vmalloc_array_noprof(size_t n, size_t size, gfp_t flags)
> {
>      size_t bytes;
> 
>      if (unlikely(check_mul_overflow(n, size, &bytes)))
>          return NULL;
>      return __vmalloc_noprof(bytes, flags);
> }
> 
> And from the code, array_size() will return SIZE_MAX after detecting
> overflow.  SIZE_MAX is passed to vmalloc for available memory
> verification before exiting and returning NULL. vmalloc_array()
> will directly return NULL after detecting overflow.

Awesome! Thank you for digging that up. Maybe something to add to the 
commit message. Maybe something like:

`vmalloc_array()` is also optimized better, resulting in less 
instructions being used, which can be verified with:

objdump -dSl --prefix-addresses <changed module>.o

>> Reviewed-by: Paul Menzel <pmenzel@molgen.mpg.de>


Kind regards,

Paul

Re: [Intel-wired-lan] [PATCH 1/5] ethtool: use vmalloc_array() to simplify code

[Qianfeng Rong]

在 2025/8/14 14:28, Paul Menzel 写道:
> [You don't often get email from pmenzel@molgen.mpg.de. Learn why this 
> is important at https://aka.ms/LearnAboutSenderIdentification ]
>
> Dear Quianfeng,
>
>
> Thank you very much for your reply.
>
> Am 14.08.25 um 06:05 schrieb Qianfeng Rong:
>>
>> 在 2025/8/13 0:34, Paul Menzel 写道:
>
> […]
>
>>> Am 12.08.25 um 15:32 schrieb Qianfeng Rong:
>>>> Remove array_size() calls and replace vmalloc() with 
>>>> vmalloc_array() to
>>>> simplify the code and maintain consistency with existing 
>>>> kmalloc_array()
>>>> usage.
>>>
>>> You could build it without and with your patch and look if the 
>>> assembler
>>> code changes.
>>
>> Very good point, the following experiment was done:
>> //before apply patch:
>> objdump -dSl --prefix-addresses fm10k_ethtool.o > original.dis
>>
>> //after apply patch:
>> objdump -dSl --prefix-addresses fm10k_ethtool.o > patched.dis
>>
>> diff -u original.dis patched.dis | diffstat
>> patched.dis | 1578 ... 1 file changed, 785 insertions(+), 793 
>> deletions(-)
>>
>> From the above results, we can see that the assembly instructions are
>> reduced after applying the patch.
>>
>>
>> #define array_size(a, b)    size_mul(a, b)
>>
>> static inline size_t __must_check size_mul(size_t factor1, size_t 
>> factor2)
>> {
>>      size_t bytes;
>>
>>      if (check_mul_overflow(factor1, factor2, &bytes))
>>          return SIZE_MAX;
>>
>>      return bytes;
>> }
>>
>> void *__vmalloc_array_noprof(size_t n, size_t size, gfp_t flags)
>> {
>>      size_t bytes;
>>
>>      if (unlikely(check_mul_overflow(n, size, &bytes)))
>>          return NULL;
>>      return __vmalloc_noprof(bytes, flags);
>> }
>>
>> And from the code, array_size() will return SIZE_MAX after detecting
>> overflow.  SIZE_MAX is passed to vmalloc for available memory
>> verification before exiting and returning NULL. vmalloc_array()
>> will directly return NULL after detecting overflow.
>
> Awesome! Thank you for digging that up. Maybe something to add to the
> commit message. Maybe something like:
>
> `vmalloc_array()` is also optimized better, resulting in less
> instructions being used, which can be verified with:
>
> objdump -dSl --prefix-addresses <changed module>.o


Ok，I'll release v2 later.

>
>>> Reviewed-by: Paul Menzel <pmenzel@molgen.mpg.de>
>
>
> Kind regards,
>
> Paul