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Date: Thu, 5 Mar 2026 08:08:46 +0100
From: Philipp Matthias Hahn <pmhahn@pmhahn.de>
To: Rosen Penev <rosenp@gmail.com>
Cc: linux-mtd@lists.infradead.org,
	Miquel Raynal <miquel.raynal@bootlin.com>,
	Richard Weinberger <richard@nod.at>,
	Vignesh Raghavendra <vigneshr@ti.com>, Kees Cook <kees@kernel.org>,
	"Gustavo A. R. Silva" <gustavoars@kernel.org>,
	open list <linux-kernel@vger.kernel.org>,
	"open list:KERNEL HARDENING (not covered by other areas):Keyword:b__counted_by(_le|_be)?b" <linux-hardening@vger.kernel.org>
Subject: Re: [PATCH 1/2] mtd: virt_concat: use single allocation for node
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Mail-Followup-To: Rosen Penev <rosenp@gmail.com>,
	linux-mtd@lists.infradead.org,
	Miquel Raynal <miquel.raynal@bootlin.com>,
	Richard Weinberger <richard@nod.at>,
	Vignesh Raghavendra <vigneshr@ti.com>, Kees Cook <kees@kernel.org>,
	"Gustavo A. R. Silva" <gustavoars@kernel.org>,
	open list <linux-kernel@vger.kernel.org>,
	"open list:KERNEL HARDENING (not covered by other areas):Keyword:b__counted_by(_le|_be)?b" <linux-hardening@vger.kernel.org>
References: <20260304221530.15018-1-rosenp@gmail.com>
 <20260304221530.15018-2-rosenp@gmail.com>
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In-Reply-To: <20260304221530.15018-2-rosenp@gmail.com>

Hello,

Am Wed, Mar 04, 2026 at 02:15:29PM -0800 schrieb Rosen Penev:
> Also add __counted_by attribute for extra runtime analysis.
…
> diff --git a/drivers/mtd/mtd_virt_concat.c b/drivers/mtd/mtd_virt_concat.c
> index aea88d1c9bc5..89e223edac6a 100644
> --- a/drivers/mtd/mtd_virt_concat.c
> +++ b/drivers/mtd/mtd_virt_concat.c
> @@ -31,8 +31,8 @@ static LIST_HEAD(concat_node_list);
>  struct mtd_virt_concat_node {
>  	struct list_head head;
>  	unsigned int count;
> -	struct device_node **nodes;
>  	struct mtd_concat *concat;
> +	struct device_node *nodes[] __counted_by(nodes);

Looks wrong. Your follow-up patch does that:
-       struct device_node *nodes[] __counted_by(nodes);
+       struct device_node *nodes[] __counted_by(count);

Philipp