netdev - Re: [PATCH net-next v5 4/6] Convert neighbour iteration to use hlist+macro

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: <20241018114200.GG1697@kernel.org>
Date: Fri, 18 Oct 2024 12:42:00 +0100
From: Simon Horman <horms@...nel.org>
To: Gilad Naaman <gnaaman@...venets.com>
Cc: netdev <netdev@...r.kernel.org>,
	"David S. Miller" <davem@...emloft.net>,
	Eric Dumazet <edumazet@...gle.com>,
	Jakub Kicinski <kuba@...nel.org>, Paolo Abeni <pabeni@...hat.com>,
	Kuniyuki Iwashima <kuniyu@...zon.com>,
	Ido Schimmel <idosch@...dia.com>, Petr Machata <petrm@...dia.com>
Subject: Re: [PATCH net-next v5 4/6] Convert neighbour iteration to use
 hlist+macro

On Thu, Oct 17, 2024 at 07:04:39AM +0000, Gilad Naaman wrote:
> Remove all usage of the bare neighbour::next pointer,
> replacing them with neighbour::hash and its for_each macro.
> 
> Signed-off-by: Gilad Naaman <gnaaman@...venets.com>

...

> diff --git a/net/core/neighbour.c b/net/core/neighbour.c

...

> @@ -621,11 +620,9 @@ static struct neigh_hash_table *neigh_hash_grow(struct neigh_table *tbl,
>  
>  	for (i = 0; i < (1 << old_nht->hash_shift); i++) {
>  		struct neighbour *n, *next;
> +		struct hlist_node *tmp;
>  
> -		for (n = rcu_dereference_protected(old_nht->hash_buckets[i],
> -						   lockdep_is_held(&tbl->lock));
> -		     n != NULL;
> -		     n = next) {
> +		neigh_for_each_safe(n, tmp, &old_nht->hash_heads[i]) {
>  			hash = tbl->hash(n->primary_key, n->dev,
>  					 new_nht->hash_rnd);
>  

Hi Gilad,

With this change next is now set but otherwise unused in this function.
Probably it can be removed.

Flagged by W=1 x86_64 allmodconfig builds with gcc-14 and clang-18.

...