2017-04-25 01:46:04

by Orson Zhai

Subject: [PATCH] iio: core: Fix suspicious sizeof usage

Pointer size is variours in different system, say 32bit for 4 and 64bit
for 8. The 'sizeof(infomask)' may lead to wrong bit numbers.

Signed-off-by: Orson Zhai <[email protected]>
---
drivers/iio/industrialio-core.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
index 3ff91e0..795f53c 100644
--- a/drivers/iio/industrialio-core.c
+++ b/drivers/iio/industrialio-core.c
@@ -1089,7 +1089,7 @@ static int iio_device_add_info_mask_type(struct iio_dev *indio_dev,
{
int i, ret, attrcount = 0;

- for_each_set_bit(i, infomask, sizeof(infomask)*8) {
+ for_each_set_bit(i, infomask, sizeof(*infomask)*8) {
if (i >= ARRAY_SIZE(iio_chan_info_postfix))
return -EINVAL;
ret = __iio_add_chan_devattr(iio_chan_info_postfix[i],
@@ -1118,7 +1118,7 @@ static int iio_device_add_info_mask_type_avail(struct iio_dev *indio_dev,
int i, ret, attrcount = 0;
char *avail_postfix;

- for_each_set_bit(i, infomask, sizeof(infomask) * 8) {
+ for_each_set_bit(i, infomask, sizeof(*infomask) * 8) {
avail_postfix = kasprintf(GFP_KERNEL,
"%s_available",
iio_chan_info_postfix[i]);
--
1.9.1

2017-04-27 05:32:37

by Jonathan Cameron

Subject: Re: [PATCH] iio: core: Fix suspicious sizeof usage

On 25/04/17 02:16, Orson Zhai wrote:
> Pointer size is variours in different system, say 32bit for 4 and 64bit
> for 8. The 'sizeof(infomask)' may lead to wrong bit numbers.
>
> Signed-off-by: Orson Zhai <[email protected]>
That's certainly been there a while. oops.

Anyhow, whilst clearly garbage, it doesn't actually have an effect
at the moment due to the relatively small number of bits that can be
set and the fact this is limited by 32 bit platforms anyway.

So applied to the togreg branch of iio.git and pushed out as
testing for the auto builders to play with it.

Thanks,

Jonathan
> ---
> drivers/iio/industrialio-core.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
> index 3ff91e0..795f53c 100644
> --- a/drivers/iio/industrialio-core.c
> +++ b/drivers/iio/industrialio-core.c
> @@ -1089,7 +1089,7 @@ static int iio_device_add_info_mask_type(struct iio_dev *indio_dev,
> {
> int i, ret, attrcount = 0;
>
> - for_each_set_bit(i, infomask, sizeof(infomask)*8) {
> + for_each_set_bit(i, infomask, sizeof(*infomask)*8) {
> if (i >= ARRAY_SIZE(iio_chan_info_postfix))
> return -EINVAL;
> ret = __iio_add_chan_devattr(iio_chan_info_postfix[i],
> @@ -1118,7 +1118,7 @@ static int iio_device_add_info_mask_type_avail(struct iio_dev *indio_dev,
> int i, ret, attrcount = 0;
> char *avail_postfix;
>
> - for_each_set_bit(i, infomask, sizeof(infomask) * 8) {
> + for_each_set_bit(i, infomask, sizeof(*infomask) * 8) {
> avail_postfix = kasprintf(GFP_KERNEL,
> "%s_available",
> iio_chan_info_postfix[i]);
>

2017-04-27 07:33:05

by Orson Zhai

Subject: Re: [PATCH] iio: core: Fix suspicious sizeof usage

On Thu, Apr 27, 2017 at 06:32:22AM +0100, Jonathan Cameron wrote:
> On 25/04/17 02:16, Orson Zhai wrote:
> > Pointer size is variours in different system, say 32bit for 4 and 64bit
> > for 8. The 'sizeof(infomask)' may lead to wrong bit numbers.
> >
> > Signed-off-by: Orson Zhai <[email protected]>
> That's certainly been there a while. oops.
>
> Anyhow, whilst clearly garbage, it doesn't actually have an effect
> at the moment due to the relatively small number of bits that can be
> set and the fact this is limited by 32 bit platforms anyway.
>
> So applied to the togreg branch of iio.git and pushed out as
> testing for the auto builders to play with it.

Thank you!

-Orson

>
> Thanks,
>
> Jonathan
> > ---
> > drivers/iio/industrialio-core.c | 4 ++--
> > 1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
> > index 3ff91e0..795f53c 100644
> > --- a/drivers/iio/industrialio-core.c
> > +++ b/drivers/iio/industrialio-core.c
> > @@ -1089,7 +1089,7 @@ static int iio_device_add_info_mask_type(struct iio_dev *indio_dev,
> > {
> > int i, ret, attrcount = 0;
> >
> > - for_each_set_bit(i, infomask, sizeof(infomask)*8) {
> > + for_each_set_bit(i, infomask, sizeof(*infomask)*8) {
> > if (i >= ARRAY_SIZE(iio_chan_info_postfix))
> > return -EINVAL;
> > ret = __iio_add_chan_devattr(iio_chan_info_postfix[i],
> > @@ -1118,7 +1118,7 @@ static int iio_device_add_info_mask_type_avail(struct iio_dev *indio_dev,
> > int i, ret, attrcount = 0;
> > char *avail_postfix;
> >
> > - for_each_set_bit(i, infomask, sizeof(infomask) * 8) {
> > + for_each_set_bit(i, infomask, sizeof(*infomask) * 8) {
> > avail_postfix = kasprintf(GFP_KERNEL,
> > "%s_available",
> > iio_chan_info_postfix[i]);
> >
>