linux-kernel - Re: [PATCH] clk: at91: generated: consider range when calculating best rate

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: <20220422011216.A4A23C385A5@smtp.kernel.org>
Date:   Thu, 21 Apr 2022 18:12:14 -0700
From:   Stephen Boyd <sboyd@...nel.org>
To:     Codrin Ciubotariu <codrin.ciubotariu@...rochip.com>,
        linux-arm-kernel@...ts.infradead.org, linux-clk@...r.kernel.org,
        linux-kernel@...r.kernel.org
Cc:     mturquette@...libre.com, nicolas.ferre@...rochip.com,
        alexandre.belloni@...tlin.com, claudiu.beznea@...rochip.com,
        Codrin Ciubotariu <codrin.ciubotariu@...rochip.com>
Subject: Re: [PATCH] clk: at91: generated: consider range when calculating best rate

Quoting Codrin Ciubotariu (2022-04-13 00:13:18)
> clk_generated_best_diff() helps in finding the parent and the divisor to
> compute a rate closest to the required one. However, it doesn't take into
> account the request's range for the new rate. Make sure the new rate
> is within the required range.
> 
> Fixes: 8a8f4bf0c480 ("clk: at91: clk-generated: create function to find best_diff")
> Signed-off-by: Codrin Ciubotariu <codrin.ciubotariu@...rochip.com>
> ---

Is this fixing anything real or it's just a thing that you noticed and
sent a patch to fix?

>  drivers/clk/at91/clk-generated.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/clk/at91/clk-generated.c b/drivers/clk/at91/clk-generated.c
> index 23cc8297ec4c..d429ba52a719 100644
> --- a/drivers/clk/at91/clk-generated.c
> +++ b/drivers/clk/at91/clk-generated.c
> @@ -117,6 +117,10 @@ static void clk_generated_best_diff(struct clk_rate_request *req,
>                 tmp_rate = parent_rate;
>         else
>                 tmp_rate = parent_rate / div;
> +
> +       if (tmp_rate < req->min_rate || tmp_rate > req->max_rate)
> +               return;
> +
>         tmp_diff = abs(req->rate - tmp_rate);
>  
>         if (*best_diff < 0 || *best_diff >= tmp_diff) {