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 <[email protected]>
---
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
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 <[email protected]>
Acked-by: Phil Reid <[email protected]>
> ---
> 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
http://www.electromag.com.au
3 The Avenue, Midland WA 6056, AUSTRALIA
Ph: +61 8 9250 8100
Fax: +61 8 9250 7100
Email: [email protected]
On Fri, Mar 11, 2016 at 5:31 PM, Geert Uytterhoeven
<[email protected]> 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 <[email protected]>
Patch applied for fixes. Tagged for stable.
Ack from Phil.
Yours,
Linus Walleij