[PATCH 0/5] gpio: aggregator: Fix Smatch warnings

[PATCH 0/5] gpio: aggregator: Fix Smatch warnings

[Dan Carpenter]

Fix some static checker warnings from Smatch:
https://github.com/error27/smatch

Dan Carpenter (5):
  gpio: aggregator: fix "_sysfs" prefix check in
    gpio_aggregator_make_group()
  gpio: aggregator: Fix gpio_aggregator_line_alloc() checking
  gpio: aggregator: Return an error if there are no GPIOs in
    gpio_aggregator_parse()
  gpio: aggregator: Fix error code in gpio_aggregator_activate()
  gpio: aggregator: Fix leak in gpio_aggregator_parse()

 drivers/gpio/gpio-aggregator.c | 21 ++++++++++++---------
 1 file changed, 12 insertions(+), 9 deletions(-)

-- 
2.47.2

[PATCH 1/5] gpio: aggregator: fix "_sysfs" prefix check in gpio_aggregator_make_group()

[Dan Carpenter]

This code is intended to reject strings that start with "_sysfs" but the
strcmp() limit is wrong so checks the whole string instead of the prefix.

Fixes: 83c8e3df642f ("gpio: aggregator: expose aggregator created via legacy sysfs to configfs")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
---
 drivers/gpio/gpio-aggregator.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpio/gpio-aggregator.c b/drivers/gpio/gpio-aggregator.c
index dde969f29ee2..b4c9e373a6ec 100644
--- a/drivers/gpio/gpio-aggregator.c
+++ b/drivers/gpio/gpio-aggregator.c
@@ -1016,7 +1016,7 @@ gpio_aggregator_make_group(struct config_group *group, const char *name)
 	 * for devices create via legacy sysfs interface.
 	 */
 	if (strncmp(name, AGGREGATOR_LEGACY_PREFIX,
-		    sizeof(AGGREGATOR_LEGACY_PREFIX)) == 0)
+		    sizeof(AGGREGATOR_LEGACY_PREFIX) - 1) == 0)
 		return ERR_PTR(-EINVAL);
 
 	/* arg space is unneeded */
-- 
2.47.2

Re: [PATCH 1/5] gpio: aggregator: fix "_sysfs" prefix check in gpio_aggregator_make_group()

[Geert Uytterhoeven]

Hi Dan,

On Sat, 12 Apr 2025 at 12:15, Dan Carpenter <dan.carpenter@linaro.org> wrote:
> This code is intended to reject strings that start with "_sysfs" but the
> strcmp() limit is wrong so checks the whole string instead of the prefix.
>
> Fixes: 83c8e3df642f ("gpio: aggregator: expose aggregator created via legacy sysfs to configfs")
> Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>

Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>

> --- a/drivers/gpio/gpio-aggregator.c
> +++ b/drivers/gpio/gpio-aggregator.c
> @@ -1016,7 +1016,7 @@ gpio_aggregator_make_group(struct config_group *group, const char *name)
>          * for devices create via legacy sysfs interface.
>          */
>         if (strncmp(name, AGGREGATOR_LEGACY_PREFIX,
> -                   sizeof(AGGREGATOR_LEGACY_PREFIX)) == 0)
> +                   sizeof(AGGREGATOR_LEGACY_PREFIX) - 1) == 0)

Or perhaps just strlen()? The compiler should optimize that to a constant, too.

>                 return ERR_PTR(-EINVAL);
>
>         /* arg space is unneeded */

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Re: [PATCH 1/5] gpio: aggregator: fix "_sysfs" prefix check in gpio_aggregator_make_group()

[Andy Shevchenko]

On Sat, Apr 12, 2025 at 01:15:00PM +0300, Dan Carpenter wrote:
> This code is intended to reject strings that start with "_sysfs" but the
> strcmp() limit is wrong so checks the whole string instead of the prefix.

...

>  	if (strncmp(name, AGGREGATOR_LEGACY_PREFIX,
> -		    sizeof(AGGREGATOR_LEGACY_PREFIX)) == 0)
> +		    sizeof(AGGREGATOR_LEGACY_PREFIX) - 1) == 0)
>  		return ERR_PTR(-EINVAL);

Wouldn't be better to use strstarts() / str_has_prefix()?

-- 
With Best Regards,
Andy Shevchenko

[PATCH 2/5] gpio: aggregator: Fix gpio_aggregator_line_alloc() checking

[Dan Carpenter]

The gpio_aggregator_line_alloc() function returns error pointers, but
the callers check for NULL.  Update the error checking in the callers.

Fixes: 83c8e3df642f ("gpio: aggregator: expose aggregator created via legacy sysfs to configfs")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
---
 drivers/gpio/gpio-aggregator.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/gpio/gpio-aggregator.c b/drivers/gpio/gpio-aggregator.c
index b4c9e373a6ec..e1b2efc0df99 100644
--- a/drivers/gpio/gpio-aggregator.c
+++ b/drivers/gpio/gpio-aggregator.c
@@ -984,8 +984,8 @@ gpio_aggregator_device_make_group(struct config_group *group, const char *name)
 			return ERR_PTR(-EINVAL);
 
 	line = gpio_aggregator_line_alloc(aggr, idx, NULL, -1);
-	if (!line)
-		return ERR_PTR(-ENOMEM);
+	if (IS_ERR(line))
+		return ERR_CAST(line);
 
 	config_group_init_type_name(&line->group, name, &gpio_aggregator_line_type);
 
@@ -1074,8 +1074,8 @@ static int gpio_aggregator_parse(struct gpio_aggregator *aggr)
 			/* Named GPIO line */
 			scnprintf(name, sizeof(name), "line%u", n);
 			line = gpio_aggregator_line_alloc(aggr, n, key, -1);
-			if (!line) {
-				error = -ENOMEM;
+			if (IS_ERR(line)) {
+				error = PTR_ERR(line);
 				goto err;
 			}
 			config_group_init_type_name(&line->group, name,
@@ -1105,8 +1105,8 @@ static int gpio_aggregator_parse(struct gpio_aggregator *aggr)
 		for_each_set_bit(i, bitmap, AGGREGATOR_MAX_GPIOS) {
 			scnprintf(name, sizeof(name), "line%u", n);
 			line = gpio_aggregator_line_alloc(aggr, n, key, i);
-			if (!line) {
-				error = -ENOMEM;
+			if (IS_ERR(line)) {
+				error = PTR_ERR(line);
 				goto err;
 			}
 			config_group_init_type_name(&line->group, name,
-- 
2.47.2

[PATCH 3/5] gpio: aggregator: Return an error if there are no GPIOs in gpio_aggregator_parse()

[Dan Carpenter]

The error handling in gpio_aggregator_parse() was re-written.  It now
returns success if there are no GPIOs.  Restore the previous behavior
and return -EINVAL instead.

Fixes: 83c8e3df642f ("gpio: aggregator: expose aggregator created via legacy sysfs to configfs")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
---
 drivers/gpio/gpio-aggregator.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/gpio/gpio-aggregator.c b/drivers/gpio/gpio-aggregator.c
index e1b2efc0df99..62bb50af7cda 100644
--- a/drivers/gpio/gpio-aggregator.c
+++ b/drivers/gpio/gpio-aggregator.c
@@ -1128,6 +1128,7 @@ static int gpio_aggregator_parse(struct gpio_aggregator *aggr)
 
 	if (!n) {
 		pr_err("No GPIOs specified\n");
+		error = -EINVAL;
 		goto err;
 	}
 
-- 
2.47.2

[PATCH 4/5] gpio: aggregator: Fix error code in gpio_aggregator_activate()

[Dan Carpenter]

Propagate the error code if gpio_aggregator_make_device_sw_node() fails.
Don't return success.

Fixes: 86f162e73d2d ("gpio: aggregator: introduce basic configfs interface")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
---
 drivers/gpio/gpio-aggregator.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/gpio/gpio-aggregator.c b/drivers/gpio/gpio-aggregator.c
index 62bb50af7cda..071d76dbfcec 100644
--- a/drivers/gpio/gpio-aggregator.c
+++ b/drivers/gpio/gpio-aggregator.c
@@ -626,8 +626,10 @@ static int gpio_aggregator_activate(struct gpio_aggregator *aggr)
 		return -ENOMEM;
 
 	swnode = gpio_aggregator_make_device_sw_node(aggr);
-	if (IS_ERR(swnode))
+	if (IS_ERR(swnode)) {
+		ret = PTR_ERR(swnode);
 		goto err_remove_lookups;
+	}
 
 	memset(&pdevinfo, 0, sizeof(pdevinfo));
 	pdevinfo.name = DRV_NAME;
-- 
2.47.2

[PATCH 5/5] gpio: aggregator: Fix leak in gpio_aggregator_parse()

[Dan Carpenter]

Call gpio_aggregator_free_lines() before returning on this error path.

Fixes: 83c8e3df642f ("gpio: aggregator: expose aggregator created via legacy sysfs to configfs")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
---
 drivers/gpio/gpio-aggregator.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpio/gpio-aggregator.c b/drivers/gpio/gpio-aggregator.c
index 071d76dbfcec..6f941db02c04 100644
--- a/drivers/gpio/gpio-aggregator.c
+++ b/drivers/gpio/gpio-aggregator.c
@@ -1101,7 +1101,7 @@ static int gpio_aggregator_parse(struct gpio_aggregator *aggr)
 		error = bitmap_parselist(offsets, bitmap, AGGREGATOR_MAX_GPIOS);
 		if (error) {
 			pr_err("Cannot parse %s: %d\n", offsets, error);
-			return error;
+			goto err;
 		}
 
 		for_each_set_bit(i, bitmap, AGGREGATOR_MAX_GPIOS) {
-- 
2.47.2

Re: [PATCH 0/5] gpio: aggregator: Fix Smatch warnings

[Koichiro Den]

On Sat, Apr 12, 2025 at 01:14:53PM GMT, Dan Carpenter wrote:
> Fix some static checker warnings from Smatch:
> https://github.com/error27/smatch
> 
> Dan Carpenter (5):
>   gpio: aggregator: fix "_sysfs" prefix check in
>     gpio_aggregator_make_group()
>   gpio: aggregator: Fix gpio_aggregator_line_alloc() checking
>   gpio: aggregator: Return an error if there are no GPIOs in
>     gpio_aggregator_parse()
>   gpio: aggregator: Fix error code in gpio_aggregator_activate()
>   gpio: aggregator: Fix leak in gpio_aggregator_parse()
> 
>  drivers/gpio/gpio-aggregator.c | 21 ++++++++++++---------
>  1 file changed, 12 insertions(+), 9 deletions(-)

Thank you very much for spotting these issues. I doubt myself for having
overlooked these.. And I had actually forgotten to run Smatch (it's really
amazing tool). I also tested the patched module by running kselftest
(gpio-aggregator.sh), with the addition of a new test case for the issue
that your first patch uncovered. I'll submit a patch to add it to selftest
later.

Acked-by: Koichiro Den <koichiro.den@canonical.com>

Thanks,
Koichiro Den

> 
> -- 
> 2.47.2
> 

Re: [PATCH 0/5] gpio: aggregator: Fix Smatch warnings

[Dan Carpenter]

On Sat, Apr 12, 2025 at 11:45:08PM +0900, Koichiro Den wrote:
> On Sat, Apr 12, 2025 at 01:14:53PM GMT, Dan Carpenter wrote:
> > Fix some static checker warnings from Smatch:
> > https://github.com/error27/smatch
> > 
> > Dan Carpenter (5):
> >   gpio: aggregator: fix "_sysfs" prefix check in
> >     gpio_aggregator_make_group()
> >   gpio: aggregator: Fix gpio_aggregator_line_alloc() checking
> >   gpio: aggregator: Return an error if there are no GPIOs in
> >     gpio_aggregator_parse()
> >   gpio: aggregator: Fix error code in gpio_aggregator_activate()
> >   gpio: aggregator: Fix leak in gpio_aggregator_parse()
> > 
> >  drivers/gpio/gpio-aggregator.c | 21 ++++++++++++---------
> >  1 file changed, 12 insertions(+), 9 deletions(-)
> 
> Thank you very much for spotting these issues. I doubt myself for having
> overlooked these.

Heh.  Don't beat yourself up.  Humans can never compete with a computer
at being nit-picky.

regards,
dan carpenter

Re: [PATCH 0/5] gpio: aggregator: Fix Smatch warnings

[Bartosz Golaszewski]

On Sat, 12 Apr 2025 13:14:53 +0300, Dan Carpenter wrote:
> Fix some static checker warnings from Smatch:
> https://github.com/error27/smatch
> 
> Dan Carpenter (5):
>   gpio: aggregator: fix "_sysfs" prefix check in
>     gpio_aggregator_make_group()
>   gpio: aggregator: Fix gpio_aggregator_line_alloc() checking
>   gpio: aggregator: Return an error if there are no GPIOs in
>     gpio_aggregator_parse()
>   gpio: aggregator: Fix error code in gpio_aggregator_activate()
>   gpio: aggregator: Fix leak in gpio_aggregator_parse()
> 
> [...]

Applied, thanks!

[1/5] gpio: aggregator: fix "_sysfs" prefix check in gpio_aggregator_make_group()
      https://git.kernel.org/brgl/linux/c/eebfcb98cdc0228f5e1b7407f9db1c602bd8e545
[2/5] gpio: aggregator: Fix gpio_aggregator_line_alloc() checking
      https://git.kernel.org/brgl/linux/c/2e8636ca340002f3ac31383622911a1aa75fb086
[3/5] gpio: aggregator: Return an error if there are no GPIOs in gpio_aggregator_parse()
      https://git.kernel.org/brgl/linux/c/db1baf69e563fc222a75c0add5c76f437c717ac0
[4/5] gpio: aggregator: Fix error code in gpio_aggregator_activate()
      https://git.kernel.org/brgl/linux/c/05b43de95add3d787a7a88378086bf01c10b3f40
[5/5] gpio: aggregator: Fix leak in gpio_aggregator_parse()
      https://git.kernel.org/brgl/linux/c/d945ff52642d98eb6fa191f88a9cfde729129395

Best regards,
-- 
Bartosz Golaszewski <brgl@bgdev.pl>