netdev - Re: [PATCH net v2 1/3] net_sched: sch_sfq: use a temporary work area for validating configuration

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: <20250402134631.5af060dc@hermes.local>
Date: Wed, 2 Apr 2025 13:46:31 -0700
From: Stephen Hemminger <stephen@...workplumber.org>
To: Octavian Purdila <tavip@...gle.com>
Cc: jhs@...atatu.com, xiyou.wangcong@...il.com, jiri@...nulli.us,
 davem@...emloft.net, edumazet@...gle.com, kuba@...nel.org,
 pabeni@...hat.com, horms@...nel.org, shuah@...nel.org,
 netdev@...r.kernel.org
Subject: Re: [PATCH net v2 1/3] net_sched: sch_sfq: use a temporary work
 area for validating configuration

On Wed,  2 Apr 2025 09:27:48 -0700
Octavian Purdila <tavip@...gle.com> wrote:

> diff --git a/net/sched/sch_sfq.c b/net/sched/sch_sfq.c
> index 65d5b59da583..1af06cd5034a 100644
> --- a/net/sched/sch_sfq.c
> +++ b/net/sched/sch_sfq.c
> @@ -631,6 +631,16 @@ static int sfq_change(struct Qdisc *sch, struct nlattr *opt,
>  	struct red_parms *p = NULL;
>  	struct sk_buff *to_free = NULL;
>  	struct sk_buff *tail = NULL;
> +	/* work area for validating changes before committing them */
Unnecessary comment.
> +	int limit;
> +	unsigned int divisor;
> +	unsigned int maxflows;
> +	int perturb_period;
> +	unsigned int quantum;
> +	u8 headdrop;
> +	u8 maxdepth;
> +	u8 flags;
> +

Network code prefers reverse christmas tree style declaration order.

+	/* copy configuration to work area */
+	limit = q->limit;
+	divisor = q->divisor;
+	headdrop = q->headdrop;
+	maxdepth = q->maxdepth;
+	maxflows = q->maxflows;
+	perturb_period = q->perturb_period;
+	quantum = q->quantum;
+	flags = q->flags;

Comment is unneeded. Rather than doing individual fields, why not just use
a whole temporary structure?