linux-kernel - Re: [PATCH v4 6/9] i2c: atr: allow replacing mappings in attach

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: <20250430163356.17eedc2f@booty>
Date: Wed, 30 Apr 2025 16:33:56 +0200
From: Luca Ceresoli <luca.ceresoli@...tlin.com>
To: Cosmin Tanislav <demonsingur@...il.com>
Cc: Tomi Valkeinen <tomi.valkeinen@...asonboard.com>, Wolfram Sang
 <wsa+renesas@...g-engineering.com>, Mauro Carvalho Chehab
 <mchehab@...nel.org>, Romain Gantois <romain.gantois@...tlin.com>, Arnd
 Bergmann <arnd@...db.de>, Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
 linux-i2c@...r.kernel.org, linux-kernel@...r.kernel.org,
 linux-media@...r.kernel.org
Subject: Re: [PATCH v4 6/9] i2c: atr: allow replacing mappings in
 attach_addr()

On Mon, 28 Apr 2025 13:25:11 +0300
Cosmin Tanislav <demonsingur@...il.com> wrote:

> It is possible for aliases to be exhausted while we are still attaching
> children.
> 
> Allow replacing mapping on attach by calling
> i2c_atr_replace_mapping_by_addr() if i2c_atr_create_mapping_by_addr()
> fails.
> 
> Signed-off-by: Cosmin Tanislav <demonsingur@...il.com>
> ---
>  drivers/i2c/i2c-atr.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/i2c/i2c-atr.c b/drivers/i2c/i2c-atr.c
> index bf7b2ac5e9cf..7214a59ddf15 100644
> --- a/drivers/i2c/i2c-atr.c
> +++ b/drivers/i2c/i2c-atr.c
> @@ -543,6 +543,9 @@ static int i2c_atr_attach_addr(struct i2c_adapter *adapter,
>  	mutex_lock(&chan->alias_pairs_lock);
>  
>  	c2a = i2c_atr_create_mapping_by_addr(chan, addr);
> +	if (!c2a)
> +		c2a = i2c_atr_replace_mapping_by_addr(chan, addr);
> +
>  	if (!c2a) {
>  		dev_err(atr->dev, "failed to find a free alias\n");
>  		ret = -EBUSY;

Looks like this should be squashed into patch 5, no? I might be
wrong, but IIUC the change in patch 5 is introducing a "bug" ("It is
possible for aliases to be exhausted while we are still attaching
children") and this patch fixes it.

Ah, nitpick: I wouldn't add that empty line.

Luca

-- 
Luca Ceresoli, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com