lkml.org 
[lkml]   [2013]   [Nov]   [30]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 3/3] pinctrl: single: fix infinite loop caused by bad mask
* Tomi Valkeinen <tomi.valkeinen@ti.com> [131128 03:30]:
> If the masks in DT data are not quite right,
> pcs_parse_bits_in_pinctrl_entry() can end up in an infinite loop,
> trashing memory at the same time.
>
> Add a check to verify that each loop actually removes bits from the
> 'mask', so that the loop can eventually end.

Linus W, might be worth updating the change log with the regression
causing commit. Something like commit 4e7e8017a80e1 (pinctrl: pinctrl-single:
enhance to configure multiple pins of different modules) improved
support for pinctrl-single,bits option, but also caused a regression
in parsing badly configured mask data.

Acked-by: Tony Lindgren <tony@atomide.com>

> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
> ---
> drivers/pinctrl/pinctrl-single.c | 8 ++++++++
> 1 file changed, 8 insertions(+)
>
> diff --git a/drivers/pinctrl/pinctrl-single.c b/drivers/pinctrl/pinctrl-single.c
> index 174f4c50cd77..de6459628b4f 100644
> --- a/drivers/pinctrl/pinctrl-single.c
> +++ b/drivers/pinctrl/pinctrl-single.c
> @@ -1318,6 +1318,14 @@ static int pcs_parse_bits_in_pinctrl_entry(struct pcs_device *pcs,
> mask_pos = ((pcs->fmask) << (bit_pos - 1));
> val_pos = val & mask_pos;
> submask = mask & mask_pos;
> +
> + if ((mask & mask_pos) == 0) {
> + dev_err(pcs->dev,
> + "Invalid mask for %s at 0x%x\n",
> + np->name, offset);
> + break;
> + }
> +
> mask &= ~mask_pos;
>
> if (submask != mask_pos) {
> --
> 1.8.3.2
>


\
 
 \ /
  Last update: 2013-11-30 18:41    [W:0.054 / U:0.256 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site