[PATCH v1 1/1] gpiolib: cdev: use !mem_is_zero() instead of memchr_inv(s, 0, n)

[PATCH v1 1/1] gpiolib: cdev: use !mem_is_zero() instead of memchr_inv(s, 0, n)

[Andy Shevchenko]

Use the mem_is_zero() helper where possible.

Signed-off-by: Andy Shevchenko <andy.shevchenko@gmail.com>
---
 drivers/gpio/gpiolib-cdev.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/gpio/gpiolib-cdev.c b/drivers/gpio/gpiolib-cdev.c
index 5aac59de0d76..e98d75dd8acd 100644
--- a/drivers/gpio/gpiolib-cdev.c
+++ b/drivers/gpio/gpiolib-cdev.c
@@ -16,7 +16,6 @@
 #include <linux/hte.h>
 #include <linux/interrupt.h>
 #include <linux/irqreturn.h>
-#include <linux/kernel.h>
 #include <linux/kfifo.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
@@ -26,6 +25,7 @@
 #include <linux/rbtree.h>
 #include <linux/seq_file.h>
 #include <linux/spinlock.h>
+#include <linux/string.h>
 #include <linux/timekeeping.h>
 #include <linux/uaccess.h>
 #include <linux/workqueue.h>
@@ -1331,7 +1331,7 @@ static int gpio_v2_line_config_validate(struct gpio_v2_line_config *lc,
 	if (lc->num_attrs > GPIO_V2_LINE_NUM_ATTRS_MAX)
 		return -EINVAL;
 
-	if (memchr_inv(lc->padding, 0, sizeof(lc->padding)))
+	if (!mem_is_zero(lc->padding, sizeof(lc->padding)))
 		return -EINVAL;
 
 	for (i = 0; i < num_lines; i++) {
@@ -1746,7 +1746,7 @@ static int linereq_create(struct gpio_device *gdev, void __user *ip)
 	if ((ulr.num_lines == 0) || (ulr.num_lines > GPIO_V2_LINES_MAX))
 		return -EINVAL;
 
-	if (memchr_inv(ulr.padding, 0, sizeof(ulr.padding)))
+	if (!mem_is_zero(ulr.padding, sizeof(ulr.padding)))
 		return -EINVAL;
 
 	lc = &ulr.config;
@@ -2516,7 +2516,7 @@ static int lineinfo_get(struct gpio_chardev_data *cdev, void __user *ip,
 	if (copy_from_user(&lineinfo, ip, sizeof(lineinfo)))
 		return -EFAULT;
 
-	if (memchr_inv(lineinfo.padding, 0, sizeof(lineinfo.padding)))
+	if (!mem_is_zero(lineinfo.padding, sizeof(lineinfo.padding)))
 		return -EINVAL;
 
 	desc = gpio_device_get_desc(cdev->gdev, lineinfo.offset);
-- 
2.46.0

Re: [PATCH v1 1/1] gpiolib: cdev: use !mem_is_zero() instead of memchr_inv(s, 0, n)

[Kent Gibson]

On Wed, Sep 04, 2024 at 12:07:43PM +0300, Andy Shevchenko wrote:
> Use the mem_is_zero() helper where possible.
>
> Signed-off-by: Andy Shevchenko <andy.shevchenko@gmail.com>

Somehow I still don't receive mail directly from you, so I only picked
this up via the list. Weird. It should be gmail to gmail, right - WTH?
Unless it isn't - and that is the problem.

I'm ok with the change, though mem_is_zero() hasn't hit any of the trees
I have in front of me, and I had to find the corresponding patch on lore.
Given this is explicitly the use case for it, I would've embedded the
negation in the function and the name, so mem_not_zero() rather than
!mem_is_zero(), as that reads better for me, but ok.

Acked-by: Kent Gibson <warthog618@gmail.com>

> ---
>  drivers/gpio/gpiolib-cdev.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpio/gpiolib-cdev.c b/drivers/gpio/gpiolib-cdev.c
> index 5aac59de0d76..e98d75dd8acd 100644
> --- a/drivers/gpio/gpiolib-cdev.c
> +++ b/drivers/gpio/gpiolib-cdev.c
> @@ -16,7 +16,6 @@
>  #include <linux/hte.h>
>  #include <linux/interrupt.h>
>  #include <linux/irqreturn.h>
> -#include <linux/kernel.h>
>  #include <linux/kfifo.h>
>  #include <linux/module.h>
>  #include <linux/mutex.h>
> @@ -26,6 +25,7 @@
>  #include <linux/rbtree.h>
>  #include <linux/seq_file.h>
>  #include <linux/spinlock.h>
> +#include <linux/string.h>
>  #include <linux/timekeeping.h>
>  #include <linux/uaccess.h>
>  #include <linux/workqueue.h>
> @@ -1331,7 +1331,7 @@ static int gpio_v2_line_config_validate(struct gpio_v2_line_config *lc,
>  	if (lc->num_attrs > GPIO_V2_LINE_NUM_ATTRS_MAX)
>  		return -EINVAL;
>
> -	if (memchr_inv(lc->padding, 0, sizeof(lc->padding)))
> +	if (!mem_is_zero(lc->padding, sizeof(lc->padding)))
>  		return -EINVAL;
>
>  	for (i = 0; i < num_lines; i++) {
> @@ -1746,7 +1746,7 @@ static int linereq_create(struct gpio_device *gdev, void __user *ip)
>  	if ((ulr.num_lines == 0) || (ulr.num_lines > GPIO_V2_LINES_MAX))
>  		return -EINVAL;
>
> -	if (memchr_inv(ulr.padding, 0, sizeof(ulr.padding)))
> +	if (!mem_is_zero(ulr.padding, sizeof(ulr.padding)))
>  		return -EINVAL;
>
>  	lc = &ulr.config;
> @@ -2516,7 +2516,7 @@ static int lineinfo_get(struct gpio_chardev_data *cdev, void __user *ip,
>  	if (copy_from_user(&lineinfo, ip, sizeof(lineinfo)))
>  		return -EFAULT;
>
> -	if (memchr_inv(lineinfo.padding, 0, sizeof(lineinfo.padding)))
> +	if (!mem_is_zero(lineinfo.padding, sizeof(lineinfo.padding)))
>  		return -EINVAL;
>
>  	desc = gpio_device_get_desc(cdev->gdev, lineinfo.offset);
> --
> 2.46.0
>

Re: [PATCH v1 1/1] gpiolib: cdev: use !mem_is_zero() instead of memchr_inv(s, 0, n)

[Bartosz Golaszewski]

From: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>


On Wed, 04 Sep 2024 12:07:43 +0300, Andy Shevchenko wrote:
> Use the mem_is_zero() helper where possible.
> 
> 

Applied, thanks!

[1/1] gpiolib: cdev: use !mem_is_zero() instead of memchr_inv(s, 0, n)
      commit: b1da870ba36b3f525aee9be35b2f08a1feec61a7

Best regards,
-- 
Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

Re: [PATCH v1 1/1] gpiolib: cdev: use !mem_is_zero() instead of memchr_inv(s, 0, n)

[Kent Gibson]

On Thu, Sep 05, 2024 at 09:36:20AM +0200, Bartosz Golaszewski wrote:
> From: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
>
>
> On Wed, 04 Sep 2024 12:07:43 +0300, Andy Shevchenko wrote:
> > Use the mem_is_zero() helper where possible.
> >
> >
>
> Applied, thanks!
>
> [1/1] gpiolib: cdev: use !mem_is_zero() instead of memchr_inv(s, 0, n)
>       commit: b1da870ba36b3f525aee9be35b2f08a1feec61a7
>

As per my other mail, mem_is_zero() is not defined in gpio/for-next yet.
So how does this work?

If I build for-next I get:

drivers/gpio/gpiolib-cdev.c: In function ‘gpio_v2_line_config_validate’:
drivers/gpio/gpiolib-cdev.c:1334:14: error: implicit declaration of function ‘mem_is_zero’; did you mean ‘xa_is_zero’? [-Werror=implicit-function-declaration]
 1334 |         if (!mem_is_zero(lc->padding, sizeof(lc->padding)))
      |              ^~~~~~~~~~~
      |              xa_is_zero


Cheers,
Kent.

Re: [PATCH v1 1/1] gpiolib: cdev: use !mem_is_zero() instead of memchr_inv(s, 0, n)

[Bartosz Golaszewski]

On Thu, Sep 5, 2024 at 3:01 PM Kent Gibson <warthog618@gmail.com> wrote:
>
> On Thu, Sep 05, 2024 at 09:36:20AM +0200, Bartosz Golaszewski wrote:
> > From: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
> >
> >
> > On Wed, 04 Sep 2024 12:07:43 +0300, Andy Shevchenko wrote:
> > > Use the mem_is_zero() helper where possible.
> > >
> > >
> >
> > Applied, thanks!
> >
> > [1/1] gpiolib: cdev: use !mem_is_zero() instead of memchr_inv(s, 0, n)
> >       commit: b1da870ba36b3f525aee9be35b2f08a1feec61a7
> >
>
> As per my other mail, mem_is_zero() is not defined in gpio/for-next yet.
> So how does this work?
>
> If I build for-next I get:
>
> drivers/gpio/gpiolib-cdev.c: In function ‘gpio_v2_line_config_validate’:
> drivers/gpio/gpiolib-cdev.c:1334:14: error: implicit declaration of function ‘mem_is_zero’; did you mean ‘xa_is_zero’? [-Werror=implicit-function-declaration]
>  1334 |         if (!mem_is_zero(lc->padding, sizeof(lc->padding)))
>       |              ^~~~~~~~~~~
>       |              xa_is_zero
>
>
> Cheers,
> Kent.

Ah, it'll have to wait until the next release cycle then. Sorry for
vacuuming patches too eagerly today. Dropping it.

Bart

Re: [PATCH v1 1/1] gpiolib: cdev: use !mem_is_zero() instead of memchr_inv(s, 0, n)

[Kent Gibson]

On Thu, Sep 05, 2024 at 03:04:34PM +0200, Bartosz Golaszewski wrote:
> On Thu, Sep 5, 2024 at 3:01 PM Kent Gibson <warthog618@gmail.com> wrote:
> >
> > On Thu, Sep 05, 2024 at 09:36:20AM +0200, Bartosz Golaszewski wrote:
> > > From: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
> > >
> > >
> > > On Wed, 04 Sep 2024 12:07:43 +0300, Andy Shevchenko wrote:
> > > > Use the mem_is_zero() helper where possible.
> > > >
> > > >
> > >
> > > Applied, thanks!
> > >
> > > [1/1] gpiolib: cdev: use !mem_is_zero() instead of memchr_inv(s, 0, n)
> > >       commit: b1da870ba36b3f525aee9be35b2f08a1feec61a7
> > >
> >
> > As per my other mail, mem_is_zero() is not defined in gpio/for-next yet.
> > So how does this work?
> >
> > If I build for-next I get:
> >
> > drivers/gpio/gpiolib-cdev.c: In function ‘gpio_v2_line_config_validate’:
> > drivers/gpio/gpiolib-cdev.c:1334:14: error: implicit declaration of function ‘mem_is_zero’; did you mean ‘xa_is_zero’? [-Werror=implicit-function-declaration]
> >  1334 |         if (!mem_is_zero(lc->padding, sizeof(lc->padding)))
> >       |              ^~~~~~~~~~~
> >       |              xa_is_zero
> >
> >
> > Cheers,
> > Kent.
>
> Ah, it'll have to wait until the next release cycle then. Sorry for
> vacuuming patches too eagerly today. Dropping it.
>

My bad for not being clearer in my initial mail - that was why I acked
rather than giving it a Rb - it still needs you to work out how to deal
with the other patch that it requires.

Well that and I would flip the sense of the function but, assuming that
ship has sailed, that is just grumbling.

Cheers,
Kent.

Re: [PATCH v1 1/1] gpiolib: cdev: use !mem_is_zero() instead of memchr_inv(s, 0, n)

[Andy Shevchenko]

On Thu, Sep 5, 2024 at 4:04 PM Bartosz Golaszewski <brgl@bgdev.pl> wrote:
> On Thu, Sep 5, 2024 at 3:01 PM Kent Gibson <warthog618@gmail.com> wrote:
> > On Thu, Sep 05, 2024 at 09:36:20AM +0200, Bartosz Golaszewski wrote:
> > > On Wed, 04 Sep 2024 12:07:43 +0300, Andy Shevchenko wrote:
> > > > Use the mem_is_zero() helper where possible.
> > >
> > > Applied, thanks!
> > >
> > > [1/1] gpiolib: cdev: use !mem_is_zero() instead of memchr_inv(s, 0, n)
> > >       commit: b1da870ba36b3f525aee9be35b2f08a1feec61a7
> >
> > As per my other mail, mem_is_zero() is not defined in gpio/for-next yet.
> > So how does this work?
> >
> > If I build for-next I get:
> >
> > drivers/gpio/gpiolib-cdev.c: In function ‘gpio_v2_line_config_validate’:
> > drivers/gpio/gpiolib-cdev.c:1334:14: error: implicit declaration of function ‘mem_is_zero’; did you mean ‘xa_is_zero’? [-Werror=implicit-function-declaration]
> >  1334 |         if (!mem_is_zero(lc->padding, sizeof(lc->padding)))
> >       |              ^~~~~~~~~~~
> >       |              xa_is_zero
>
> Ah, it'll have to wait until the next release cycle then. Sorry for
> vacuuming patches too eagerly today. Dropping it.

Hmm... Somehow I missed that it appeared only on Aug 19 in Linux Next.

-- 
With Best Regards,
Andy Shevchenko