* [PATCH] gpio: pca953x: Fix pca953x_gpio_set_multiple() on 64-bit
@ 2016-03-11 16:31 Geert Uytterhoeven
2016-03-12 15:20 ` Phil Reid
2016-03-16 12:03 ` Linus Walleij
0 siblings, 2 replies; 3+ messages in thread
From: Geert Uytterhoeven @ 2016-03-11 16:31 UTC (permalink / raw)
To: Linus Walleij, Alexandre Courbot, Phil Reid
Cc: linux-gpio, linux-kernel, Geert Uytterhoeven
pca953x_gpio_set_multiple() divides by 4 to convert from longs to bytes,
which assumes a 32-bit platform, and is not correct on 64-bit platforms.
Use "sizeof(...)" instead to fix this.
Fixes: b4818afeacbd8182 ("gpio: pca953x: Add set_multiple to allow multiple bits to be set in one write.")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
Untested, found by code inspection.
This bug was introduced in v4.5-rc1, but unless Linus (the other one ;-)
will make a v4.5-rc8, it's probably too late to get this fixed in v4.5.
---
drivers/gpio/gpio-pca953x.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/gpio/gpio-pca953x.c b/drivers/gpio/gpio-pca953x.c
index 23196c5fc17ceb6b..99b375c959987fe9 100644
--- a/drivers/gpio/gpio-pca953x.c
+++ b/drivers/gpio/gpio-pca953x.c
@@ -367,9 +367,11 @@ static void pca953x_gpio_set_multiple(struct gpio_chip *gc,
memcpy(reg_val, chip->reg_output, NBANK(chip));
mutex_lock(&chip->i2c_lock);
for(bank=0; bank<NBANK(chip); bank++) {
- unsigned bankmask = mask[bank/4] >> ((bank % 4) * 8);
+ unsigned bankmask = mask[bank / sizeof(*mask)] >>
+ ((bank % sizeof(*mask)) * 8);
if(bankmask) {
- unsigned bankval = bits[bank/4] >> ((bank % 4) * 8);
+ unsigned bankval = bits[bank / sizeof(*bits)] >>
+ ((bank % sizeof(*bits)) * 8);
reg_val[bank] = (reg_val[bank] & ~bankmask) | bankval;
}
}
--
1.9.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] gpio: pca953x: Fix pca953x_gpio_set_multiple() on 64-bit
2016-03-11 16:31 [PATCH] gpio: pca953x: Fix pca953x_gpio_set_multiple() on 64-bit Geert Uytterhoeven
@ 2016-03-12 15:20 ` Phil Reid
2016-03-16 12:03 ` Linus Walleij
1 sibling, 0 replies; 3+ messages in thread
From: Phil Reid @ 2016-03-12 15:20 UTC (permalink / raw)
To: Geert Uytterhoeven, Linus Walleij, Alexandre Courbot
Cc: linux-gpio, linux-kernel
On 12/03/2016 12:31 AM, Geert Uytterhoeven wrote:
> pca953x_gpio_set_multiple() divides by 4 to convert from longs to bytes,
> which assumes a 32-bit platform, and is not correct on 64-bit platforms.
> Use "sizeof(...)" instead to fix this.
>
> Fixes: b4818afeacbd8182 ("gpio: pca953x: Add set_multiple to allow multiple bits to be set in one write.")
> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Phil Reid <preid@electromag.com.au>
> ---
> Untested, found by code inspection.
>
> This bug was introduced in v4.5-rc1, but unless Linus (the other one ;-)
> will make a v4.5-rc8, it's probably too late to get this fixed in v4.5.
> ---
> drivers/gpio/gpio-pca953x.c | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpio/gpio-pca953x.c b/drivers/gpio/gpio-pca953x.c
> index 23196c5fc17ceb6b..99b375c959987fe9 100644
> --- a/drivers/gpio/gpio-pca953x.c
> +++ b/drivers/gpio/gpio-pca953x.c
> @@ -367,9 +367,11 @@ static void pca953x_gpio_set_multiple(struct gpio_chip *gc,
> memcpy(reg_val, chip->reg_output, NBANK(chip));
> mutex_lock(&chip->i2c_lock);
> for(bank=0; bank<NBANK(chip); bank++) {
> - unsigned bankmask = mask[bank/4] >> ((bank % 4) * 8);
> + unsigned bankmask = mask[bank / sizeof(*mask)] >>
> + ((bank % sizeof(*mask)) * 8);
> if(bankmask) {
> - unsigned bankval = bits[bank/4] >> ((bank % 4) * 8);
> + unsigned bankval = bits[bank / sizeof(*bits)] >>
> + ((bank % sizeof(*bits)) * 8);
> reg_val[bank] = (reg_val[bank] & ~bankmask) | bankval;
> }
> }
>
--
Regards
Phil Reid
ElectroMagnetic Imaging Technology Pty Ltd
Development of Geophysical Instrumentation & Software
www.electromag.com.au
3 The Avenue, Midland WA 6056, AUSTRALIA
Ph: +61 8 9250 8100
Fax: +61 8 9250 7100
Email: preid@electromag.com.au
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] gpio: pca953x: Fix pca953x_gpio_set_multiple() on 64-bit
2016-03-11 16:31 [PATCH] gpio: pca953x: Fix pca953x_gpio_set_multiple() on 64-bit Geert Uytterhoeven
2016-03-12 15:20 ` Phil Reid
@ 2016-03-16 12:03 ` Linus Walleij
1 sibling, 0 replies; 3+ messages in thread
From: Linus Walleij @ 2016-03-16 12:03 UTC (permalink / raw)
To: Geert Uytterhoeven; +Cc: Alexandre Courbot, Phil Reid, linux-gpio, linux-kernel
On Fri, Mar 11, 2016 at 5:31 PM, Geert Uytterhoeven
<geert+renesas@glider.be> wrote:
> pca953x_gpio_set_multiple() divides by 4 to convert from longs to bytes,
> which assumes a 32-bit platform, and is not correct on 64-bit platforms.
> Use "sizeof(...)" instead to fix this.
>
> Fixes: b4818afeacbd8182 ("gpio: pca953x: Add set_multiple to allow multiple bits to be set in one write.")
> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Patch applied for fixes. Tagged for stable.
Ack from Phil.
Yours,
Linus Walleij
^ permalink raw reply [flat|nested] 3+ messages in thread
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2016-03-12 15:20 ` Phil Reid
2016-03-16 12:03 ` Linus Walleij
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