linux-kernel - Re: [RFC PATCH 18/77] dtc-parser.y: Avoid an empty proplist

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: <aWhEG0GQp04wjcLs@zatzit>
Date: Thu, 15 Jan 2026 12:34:19 +1100
From: David Gibson <david@...son.dropbear.id.au>
To: Herve Codina <herve.codina@...tlin.com>
Cc: Rob Herring <robh@...nel.org>, Krzysztof Kozlowski <krzk@...nel.org>,
	Conor Dooley <conor+dt@...nel.org>,
	Ayush Singh <ayush@...gleboard.org>,
	Geert Uytterhoeven <geert@...ux-m68k.org>,
	devicetree-compiler@...r.kernel.org, devicetree@...r.kernel.org,
	linux-kernel@...r.kernel.org, devicetree-spec@...r.kernel.org,
	Hui Pu <hui.pu@...ealthcare.com>,
	Ian Ray <ian.ray@...ealthcare.com>,
	Luca Ceresoli <luca.ceresoli@...tlin.com>,
	Thomas Petazzoni <thomas.petazzoni@...tlin.com>
Subject: Re: [RFC PATCH 18/77] dtc-parser.y: Avoid an empty proplist

On Mon, Jan 12, 2026 at 03:19:08PM +0100, Herve Codina wrote:
> In the dts parser grammar, a nodedef is defined by
>   '{' proplist subnodes '}' ';'
> with both proplist and subnodes that can be empty lists.
> 
> Soon a new list will be added in the nodedef related to export symbol
> list.
> 
> Having all those lists with support for empty lists will lead to some
> Bison warnings:
>   warning: 4 shift/reduce conflicts [-Wconflicts-sr]
>   warning: 1 reduce/reduce conflict [-Wconflicts-rr]
> 
> The simpler way to remove those warning and thus have a robust parsing
> is to avoid those empty lists.
> 
> Update the proplist definition and nodedef definition to avoid those
> multiple empty lists. Instead of allowing a proplist to be an empty
> list, force the list to be a non empty one and update the nodedef to
> handle explicitly the absence of the proplist to support the case where
> no properties are available, i.e. the case of a node composed only of
> sub-nodes.
> 
> This doesn't change the functional behavior.
> 
> Signed-off-by: Herve Codina <herve.codina@...tlin.com>

I think it makes sense to apply this on its own before the rest of the
series, but the commit message will want rewording for that context.

> ---
>  dtc-parser.y | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
> 
> diff --git a/dtc-parser.y b/dtc-parser.y
> index d8914d2..2e152b0 100644
> --- a/dtc-parser.y
> +++ b/dtc-parser.y
> @@ -272,12 +272,16 @@ nodedef:
>  		{
>  			$$ = build_node($2, $3, &@$);
>  		}
> +	| '{' subnodes '}' ';'
> +		{
> +			$$ = build_node(NULL, $2, &@$);
> +		}
>  	;
>  
>  proplist:
> -	  /* empty */
> +	  propdef
>  		{
> -			$$ = NULL;
> +			$$ = chain_property($1, NULL);
>  		}
>  	| proplist propdef
>  		{
> -- 
> 2.52.0
> 
> 

-- 
David Gibson (he or they)	| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you, not the other way
				| around.
http://www.ozlabs.org/~dgibson

Download attachment "signature.asc" of type "application/pgp-signature" (834 bytes)