linux-kernel - Re: [PATCH net-next v3 2/2] net/mlx5: Don't use %pK through printk or tracepoints

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Message-ID: <20250619133220.GQ1699@horms.kernel.org>
Date: Thu, 19 Jun 2025 14:32:20 +0100
From: Simon Horman <horms@...nel.org>
To: Thomas Weißschuh <thomas.weissschuh@...utronix.de>
Cc: Tony Nguyen <anthony.l.nguyen@...el.com>,
	Przemek Kitszel <przemyslaw.kitszel@...el.com>,
	Andrew Lunn <andrew+netdev@...n.ch>,
	"David S. Miller" <davem@...emloft.net>,
	Eric Dumazet <edumazet@...gle.com>,
	Jakub Kicinski <kuba@...nel.org>, Paolo Abeni <pabeni@...hat.com>,
	Saeed Mahameed <saeedm@...dia.com>,
	Leon Romanovsky <leon@...nel.org>, Tariq Toukan <tariqt@...dia.com>,
	intel-wired-lan@...ts.osuosl.org, netdev@...r.kernel.org,
	linux-kernel@...r.kernel.org, linux-rdma@...r.kernel.org,
	Aleksandr Loktionov <aleksandr.loktionov@...el.com>
Subject: Re: [PATCH net-next v3 2/2] net/mlx5: Don't use %pK through printk
 or tracepoints

On Wed, Jun 18, 2025 at 09:08:07AM +0200, Thomas Weißschuh wrote:
> In the past %pK was preferable to %p as it would not leak raw pointer
> values into the kernel log.
> Since commit ad67b74d2469 ("printk: hash addresses printed with %p")
> the regular %p has been improved to avoid this issue.
> Furthermore, restricted pointers ("%pK") were never meant to be used
> through tracepoints. They can still unintentionally leak raw pointers or
> acquire sleeping locks in atomic contexts.
> 
> Switch to the regular pointer formatting which is safer and
> easier to reason about.
> There are still a few users of %pK left, but these use it through seq_file,
> for which its usage is safe.
> 
> Signed-off-by: Thomas Weißschuh <thomas.weissschuh@...utronix.de>
> Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@...el.com>
> Reviewed-by: Tariq Toukan <tariqt@...dia.com>

Reviewed-by: Simon Horman <horms@...nel.org>