netdev - Re: [PATCH net-next v3] net: mana: Implement get_ringparam/set

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20240816185805.60e16145@kernel.org>
Date: Fri, 16 Aug 2024 18:58:05 -0700
From: Jakub Kicinski <kuba@...nel.org>
To: Shradha Gupta <shradhagupta@...ux.microsoft.com>
Cc: linux-hyperv@...r.kernel.org, netdev@...r.kernel.org,
 linux-kernel@...r.kernel.org, linux-rdma@...r.kernel.org, "K. Y.
 Srinivasan" <kys@...rosoft.com>, Haiyang Zhang <haiyangz@...rosoft.com>,
 Wei Liu <wei.liu@...nel.org>, Dexuan Cui <decui@...rosoft.com>, "David S.
 Miller" <davem@...emloft.net>, Eric Dumazet <edumazet@...gle.com>, Paolo
 Abeni <pabeni@...hat.com>, Long Li <longli@...rosoft.com>, Ajay Sharma
 <sharmaajay@...rosoft.com>, Simon Horman <horms@...nel.org>, Konstantin
 Taranov <kotaranov@...rosoft.com>, Souradeep Chakrabarti
 <schakrabarti@...ux.microsoft.com>, Erick Archer
 <erick.archer@...look.com>, Pavan Chebbi <pavan.chebbi@...adcom.com>, Ahmed
 Zaki <ahmed.zaki@...el.com>, Colin Ian King <colin.i.king@...il.com>,
 Shradha Gupta <shradhagupta@...rosoft.com>
Subject: Re: [PATCH net-next v3] net: mana: Implement
 get_ringparam/set_ringparam for mana

On Fri, 16 Aug 2024 03:48:23 -0700 Shradha Gupta wrote:
> +	old_tx = apc->tx_queue_size;
> +	old_rx = apc->rx_queue_size;
> +	new_tx = clamp_t(u32, ring->tx_pending, MIN_TX_BUFFERS_PER_QUEUE, MAX_TX_BUFFERS_PER_QUEUE);
> +	new_rx = clamp_t(u32, ring->rx_pending, MIN_RX_BUFFERS_PER_QUEUE, MAX_RX_BUFFERS_PER_QUEUE);

You can min(), the max side of clam is unnecessary. Core code won't let
user requests above max provided by "get" thru.

> +	if (!is_power_of_2(new_tx)) {
> +		netdev_err(ndev, "%s:Tx:%d not supported. Needs to be a power of 2\n",
> +			   __func__, new_tx);
> +		return -EINVAL;
> +	}

The power of 2 vs clamp is a bit odd.
On one hand you clamp the values to what's supported automatically.
On the other you hard reject values which are not power of 2.
Why not round them up?

IDK whether checking or auto-correction is better, but mixing the two
is odd.

> +	if (!is_power_of_2(new_rx)) {
> +		netdev_err(ndev, "%s:Rx:%d not supported. Needs to be a power of 2\n",
> +			   __func__, new_rx);

Instead of printing please use the extack passed in as an argument.
-- 
pw-bot: cr