The find.h APIs are designed to be used only on unsigned long arguments.
This can technically result in a over-read, but it is harmless in this
case. Regardless, fix it to avoid the warning seen under -Warray-bounds,
which we'd like to enable globally:
In file included from ./include/linux/bitmap.h:9,
from ./include/linux/cpumask.h:12,
from ./arch/x86/include/asm/cpumask.h:5,
from ./arch/x86/include/asm/msr.h:11,
from ./arch/x86/include/asm/processor.h:22,
from ./arch/x86/include/asm/cpufeature.h:5,
from ./arch/x86/include/asm/thread_info.h:53,
from ./include/linux/thread_info.h:60,
from ./arch/x86/include/asm/preempt.h:7,
from ./include/linux/preempt.h:78,
from ./include/linux/spinlock.h:55,
from ./include/linux/swait.h:7,
from ./include/linux/completion.h:12,
from drivers/iio/adc/stmpe-adc.c:10:
drivers/iio/adc/stmpe-adc.c: In function 'stmpe_adc_probe':
./include/linux/find.h:98:23: warning: array subscript 'long unsigned int[0]' is partly outside array bounds of 'u32[1]' {aka 'unsigned int[1]'} [-Warray-bounds]
98 | val = *addr | ~GENMASK(size - 1, offset);
| ^~~~~
drivers/iio/adc/stmpe-adc.c:258:13: note: while referencing 'norequest_mask'
258 | u32 norequest_mask = 0;
| ^~~~~~~~~~~~~~
Signed-off-by: Kees Cook <[email protected]>
---
drivers/iio/adc/stmpe-adc.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/iio/adc/stmpe-adc.c b/drivers/iio/adc/stmpe-adc.c
index fba659bfdb40..d2d405388499 100644
--- a/drivers/iio/adc/stmpe-adc.c
+++ b/drivers/iio/adc/stmpe-adc.c
@@ -256,6 +256,7 @@ static int stmpe_adc_probe(struct platform_device *pdev)
struct stmpe_adc *info;
struct device_node *np;
u32 norequest_mask = 0;
+ unsigned long bits;
int irq_temp, irq_adc;
int num_chan = 0;
int i = 0;
@@ -309,8 +310,8 @@ static int stmpe_adc_probe(struct platform_device *pdev)
of_property_read_u32(np, "st,norequest-mask", &norequest_mask);
- for_each_clear_bit(i, (unsigned long *) &norequest_mask,
- (STMPE_ADC_LAST_NR + 1)) {
+ bits = norequest_mask;
+ for_each_clear_bit(i, &bits, (STMPE_ADC_LAST_NR + 1)) {
stmpe_adc_voltage_chan(&info->stmpe_adc_iio_channels[num_chan], i);
num_chan++;
}
--
2.30.2
On Wed, 15 Dec 2021 15:25:13 -0800
Kees Cook <[email protected]> wrote:
> The find.h APIs are designed to be used only on unsigned long arguments.
> This can technically result in a over-read, but it is harmless in this
> case. Regardless, fix it to avoid the warning seen under -Warray-bounds,
> which we'd like to enable globally:
>
> In file included from ./include/linux/bitmap.h:9,
> from ./include/linux/cpumask.h:12,
> from ./arch/x86/include/asm/cpumask.h:5,
> from ./arch/x86/include/asm/msr.h:11,
> from ./arch/x86/include/asm/processor.h:22,
> from ./arch/x86/include/asm/cpufeature.h:5,
> from ./arch/x86/include/asm/thread_info.h:53,
> from ./include/linux/thread_info.h:60,
> from ./arch/x86/include/asm/preempt.h:7,
> from ./include/linux/preempt.h:78,
> from ./include/linux/spinlock.h:55,
> from ./include/linux/swait.h:7,
> from ./include/linux/completion.h:12,
> from drivers/iio/adc/stmpe-adc.c:10:
> drivers/iio/adc/stmpe-adc.c: In function 'stmpe_adc_probe':
> ./include/linux/find.h:98:23: warning: array subscript 'long unsigned int[0]' is partly outside array bounds of 'u32[1]' {aka 'unsigned int[1]'} [-Warray-bounds]
> 98 | val = *addr | ~GENMASK(size - 1, offset);
> | ^~~~~
> drivers/iio/adc/stmpe-adc.c:258:13: note: while referencing 'norequest_mask'
> 258 | u32 norequest_mask = 0;
> | ^~~~~~~~~~~~~~
>
> Signed-off-by: Kees Cook <[email protected]>
Applied to the togreg branch of iio.git and pushed out as testing to let
0-day have a first poke at it.
I took the view this one was trivial, but if anyone else wants to add
tags there will be a few days before this goes out in a form I'm not happy
to rebase.
Thanks,
Jonathan
> ---
> drivers/iio/adc/stmpe-adc.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/iio/adc/stmpe-adc.c b/drivers/iio/adc/stmpe-adc.c
> index fba659bfdb40..d2d405388499 100644
> --- a/drivers/iio/adc/stmpe-adc.c
> +++ b/drivers/iio/adc/stmpe-adc.c
> @@ -256,6 +256,7 @@ static int stmpe_adc_probe(struct platform_device *pdev)
> struct stmpe_adc *info;
> struct device_node *np;
> u32 norequest_mask = 0;
> + unsigned long bits;
> int irq_temp, irq_adc;
> int num_chan = 0;
> int i = 0;
> @@ -309,8 +310,8 @@ static int stmpe_adc_probe(struct platform_device *pdev)
>
> of_property_read_u32(np, "st,norequest-mask", &norequest_mask);
>
> - for_each_clear_bit(i, (unsigned long *) &norequest_mask,
> - (STMPE_ADC_LAST_NR + 1)) {
> + bits = norequest_mask;
> + for_each_clear_bit(i, &bits, (STMPE_ADC_LAST_NR + 1)) {
> stmpe_adc_voltage_chan(&info->stmpe_adc_iio_channels[num_chan], i);
> num_chan++;
> }
On Wed, Dec 15, 2021 at 03:25:13PM -0800, Kees Cook wrote:
> The find.h APIs are designed to be used only on unsigned long arguments.
> This can technically result in a over-read, but it is harmless in this
> case. Regardless, fix it to avoid the warning seen under -Warray-bounds,
> which we'd like to enable globally:
>
> In file included from ./include/linux/bitmap.h:9,
> from ./include/linux/cpumask.h:12,
> from ./arch/x86/include/asm/cpumask.h:5,
> from ./arch/x86/include/asm/msr.h:11,
> from ./arch/x86/include/asm/processor.h:22,
> from ./arch/x86/include/asm/cpufeature.h:5,
> from ./arch/x86/include/asm/thread_info.h:53,
> from ./include/linux/thread_info.h:60,
> from ./arch/x86/include/asm/preempt.h:7,
> from ./include/linux/preempt.h:78,
> from ./include/linux/spinlock.h:55,
> from ./include/linux/swait.h:7,
> from ./include/linux/completion.h:12,
> from drivers/iio/adc/stmpe-adc.c:10:
> drivers/iio/adc/stmpe-adc.c: In function 'stmpe_adc_probe':
> ./include/linux/find.h:98:23: warning: array subscript 'long unsigned int[0]' is partly outside array bounds of 'u32[1]' {aka 'unsigned int[1]'} [-Warray-bounds]
> 98 | val = *addr | ~GENMASK(size - 1, offset);
> | ^~~~~
> drivers/iio/adc/stmpe-adc.c:258:13: note: while referencing 'norequest_mask'
> 258 | u32 norequest_mask = 0;
> | ^~~~~~~~~~~~~~
>
> Signed-off-by: Kees Cook <[email protected]>
> ---
> drivers/iio/adc/stmpe-adc.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/iio/adc/stmpe-adc.c b/drivers/iio/adc/stmpe-adc.c
> index fba659bfdb40..d2d405388499 100644
> --- a/drivers/iio/adc/stmpe-adc.c
> +++ b/drivers/iio/adc/stmpe-adc.c
> @@ -256,6 +256,7 @@ static int stmpe_adc_probe(struct platform_device *pdev)
> struct stmpe_adc *info;
> struct device_node *np;
> u32 norequest_mask = 0;
> + unsigned long bits;
> int irq_temp, irq_adc;
> int num_chan = 0;
> int i = 0;
> @@ -309,8 +310,8 @@ static int stmpe_adc_probe(struct platform_device *pdev)
>
> of_property_read_u32(np, "st,norequest-mask", &norequest_mask);
>
> - for_each_clear_bit(i, (unsigned long *) &norequest_mask,
> - (STMPE_ADC_LAST_NR + 1)) {
> + bits = norequest_mask;
This would not work on 64-bit BE architecture. It should use bitmap_from_arr32()
> + for_each_clear_bit(i, &bits, (STMPE_ADC_LAST_NR + 1)) {
> stmpe_adc_voltage_chan(&info->stmpe_adc_iio_channels[num_chan], i);
> num_chan++;
> }
> --
> 2.30.2
From: Yury Norov
> Sent: 04 February 2022 04:30
>
> On Wed, Dec 15, 2021 at 03:25:13PM -0800, Kees Cook wrote:
> > The find.h APIs are designed to be used only on unsigned long arguments.
> > This can technically result in a over-read, but it is harmless in this
> > case. Regardless, fix it to avoid the warning seen under -Warray-bounds,
> > which we'd like to enable globally:
> >
...
> >
> > Signed-off-by: Kees Cook <[email protected]>
> > ---
> > drivers/iio/adc/stmpe-adc.c | 5 +++--
> > 1 file changed, 3 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/iio/adc/stmpe-adc.c b/drivers/iio/adc/stmpe-adc.c
> > index fba659bfdb40..d2d405388499 100644
> > --- a/drivers/iio/adc/stmpe-adc.c
> > +++ b/drivers/iio/adc/stmpe-adc.c
> > @@ -256,6 +256,7 @@ static int stmpe_adc_probe(struct platform_device *pdev)
> > struct stmpe_adc *info;
> > struct device_node *np;
> > u32 norequest_mask = 0;
> > + unsigned long bits;
> > int irq_temp, irq_adc;
> > int num_chan = 0;
> > int i = 0;
> > @@ -309,8 +310,8 @@ static int stmpe_adc_probe(struct platform_device *pdev)
> >
> > of_property_read_u32(np, "st,norequest-mask", &norequest_mask);
> >
> > - for_each_clear_bit(i, (unsigned long *) &norequest_mask,
> > - (STMPE_ADC_LAST_NR + 1)) {
> > + bits = norequest_mask;
>
> This would not work on 64-bit BE architecture. It should use bitmap_from_arr32()
The old version was wrong on 64 bit BE, Kees version is probably ok.
But changing norequest_mask to 'unsigned long' is probably neater.
OTOH using the bitmap functions on single words is just bloat.
David
-
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