linux-kernel - Re: [PATCH v2] pinctrl: pinctrl-single: Fix pcs_parse_bits_in_pinctrl_entry to use _

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 for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CACRpkdZxY3FNti37HfuwS7KT9K+pA=REr_G=hEQRi-D3=CHUpQ@mail.gmail.com>
Date:	Fri, 15 Apr 2016 11:27:51 +0200
From:	Linus Walleij <linus.walleij@...aro.org>
To:	Keerthy <j-keerthy@...com>
Cc:	Tony Lindgren <tony@...mide.com>,
	"linux-arm-kernel@...ts.infradead.org" 
	<linux-arm-kernel@...ts.infradead.org>,
	Linux-OMAP <linux-omap@...r.kernel.org>,
	"linux-gpio@...r.kernel.org" <linux-gpio@...r.kernel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	Tero Kristo <t-kristo@...com>, Sekhar Nori <nsekhar@...com>
Subject: Re: [PATCH v2] pinctrl: pinctrl-single: Fix pcs_parse_bits_in_pinctrl_entry
 to use __ffs than ffs

On Thu, Apr 14, 2016 at 6:59 AM, Keerthy <j-keerthy@...com> wrote:

> pcs_parse_bits_in_pinctrl_entry uses ffs which gives bit indices
> ranging from 1 to MAX. This leads to a corner case where we try to request
> the pin number = MAX and fails.
>
> bit_pos value is being calculted using ffs. pin_num_from_lsb uses
> bit_pos value. pins array is populated with:
>
> pin + pin_num_from_lsb.
>
> The above is 1 more than usual bit indices as bit_pos uses ffs to compute
> first set bit. Hence the last of the pins array is populated with the MAX
> value and not MAX - 1 which causes error when we call pin_request.
>
> mask_pos is rightly calculated as ((pcs->fmask) << (bit_pos - 1))
> Consequently val_pos and submask are correct.
>
> Hence use __ffs which gives (ffs(x) - 1) as the first bit set.
>
> fixes: 4e7e8017a8 ("pinctrl: pinctrl-single: enhance to configure multiple pins of different modules")
> Signed-off-by: Keerthy <j-keerthy@...com>
> ---
>
> Changes in v2:
>
>   * Changed pcs->fshift to use __ffs instead of ffs to be consistent.
>
> Boot tesed on da850-evm and checked the pinctrl sysfs nodes.

Patch applied for fixes with Tony's ACK.

Should it also be tagged for stable?

Yours,
Linus Walleij