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pinctrl: single: fix infinite loop caused by bad mask 

commit 4e7e8017a8 (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.

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.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This commit is contained in:
Tomi Valkeinen 2014-01-09 14:50:29 +02:00 committed by Linus Walleij
parent dd4c2b3cb3
commit ad5d25fef8
1 changed files with 8 additions and 0 deletions
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8
drivers/pinctrl/pinctrl-single.c
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@ -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) {