[PATCH] staging: greybus: arche: use sysfs_emit() instead of sprintf()

[PATCH] staging: greybus: arche: use sysfs_emit() instead of sprintf()

[Ruslan Valiyev]

Replace sprintf() with sysfs_emit() in state_show() sysfs attribute
callbacks in arche-platform.c and arche-apb-ctrl.c.

sysfs_emit() is preferred over sprintf() in sysfs show functions
because it is aware of the PAGE_SIZE buffer limit, preventing
potential buffer overflows. This addresses checkpatch warnings
about the use of sprintf() in sysfs show callbacks.

Signed-off-by: Ruslan Valiyev <linuxoid@gmail.com>
---
 drivers/staging/greybus/arche-apb-ctrl.c | 10 +++++-----
 drivers/staging/greybus/arche-platform.c | 10 +++++-----
 2 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/drivers/staging/greybus/arche-apb-ctrl.c b/drivers/staging/greybus/arche-apb-ctrl.c
index 33f26a65f..19a6e59b6 100644
--- a/drivers/staging/greybus/arche-apb-ctrl.c
+++ b/drivers/staging/greybus/arche-apb-ctrl.c
@@ -300,16 +300,16 @@ static ssize_t state_show(struct device *dev,
 
 	switch (apb->state) {
 	case ARCHE_PLATFORM_STATE_OFF:
-		return sprintf(buf, "off%s\n",
+		return sysfs_emit(buf, "off%s\n",
 				apb->init_disabled ? ",disabled" : "");
 	case ARCHE_PLATFORM_STATE_ACTIVE:
-		return sprintf(buf, "active\n");
+		return sysfs_emit(buf, "active\n");
 	case ARCHE_PLATFORM_STATE_STANDBY:
-		return sprintf(buf, "standby\n");
+		return sysfs_emit(buf, "standby\n");
 	case ARCHE_PLATFORM_STATE_FW_FLASHING:
-		return sprintf(buf, "fw_flashing\n");
+		return sysfs_emit(buf, "fw_flashing\n");
 	default:
-		return sprintf(buf, "unknown state\n");
+		return sysfs_emit(buf, "unknown state\n");
 	}
 }
 
diff --git a/drivers/staging/greybus/arche-platform.c b/drivers/staging/greybus/arche-platform.c
index f669a7e2e..de5de59ea 100644
--- a/drivers/staging/greybus/arche-platform.c
+++ b/drivers/staging/greybus/arche-platform.c
@@ -374,15 +374,15 @@ static ssize_t state_show(struct device *dev,
 
 	switch (arche_pdata->state) {
 	case ARCHE_PLATFORM_STATE_OFF:
-		return sprintf(buf, "off\n");
+		return sysfs_emit(buf, "off\n");
 	case ARCHE_PLATFORM_STATE_ACTIVE:
-		return sprintf(buf, "active\n");
+		return sysfs_emit(buf, "active\n");
 	case ARCHE_PLATFORM_STATE_STANDBY:
-		return sprintf(buf, "standby\n");
+		return sysfs_emit(buf, "standby\n");
 	case ARCHE_PLATFORM_STATE_FW_FLASHING:
-		return sprintf(buf, "fw_flashing\n");
+		return sysfs_emit(buf, "fw_flashing\n");
 	default:
-		return sprintf(buf, "unknown state\n");
+		return sysfs_emit(buf, "unknown state\n");
 	}
 }
 
-- 
2.43.0

Re: [PATCH] staging: greybus: arche: use sysfs_emit() instead of sprintf()

[Dan Carpenter]

On Wed, Feb 25, 2026 at 09:29:55PM +0000, Ruslan Valiyev wrote:
> Replace sprintf() with sysfs_emit() in state_show() sysfs attribute
> callbacks in arche-platform.c and arche-apb-ctrl.c.
> 
> sysfs_emit() is preferred over sprintf() in sysfs show functions
> because it is aware of the PAGE_SIZE buffer limit, preventing
> potential buffer overflows. This addresses checkpatch warnings
> about the use of sprintf() in sysfs show callbacks.
> 
> Signed-off-by: Ruslan Valiyev <linuxoid@gmail.com>
> ---

I really want these sorts of patches to have some kind of analysis
whether the "potential buffer overflows" are actual buffer overflows or
not.  In this case, it's really easy to see that there are no buffer
overflows so it feels petty for something I can see just by glancing
at the patch...  I just got finished asking for the same thing from
someone else, but in that case I had to look up the buffer size.

Anyway, just add a sentence at the start which says that "This code is
obviously safe".  And remove the bits which mention "potential buffer
overflows".

    Checkpatch complains about code using sprintf().  This code here is
    obviously safe as-is, but it would be more appropriate to use
    sysfs_emit().

regards,
dan carpenter

[PATCH v2] staging: greybus: arche: use sysfs_emit() instead of sprintf()

[Ruslan Valiyev]

Replace sprintf() with sysfs_emit() in state_show() sysfs attribute
callbacks in arche-platform.c and arche-apb-ctrl.c.

Checkpatch complains about code using sprintf(). This code here is
obviously safe as-is, but it would be more appropriate to use
sysfs_emit().

Signed-off-by: Ruslan Valiyev <linuxoid@gmail.com>
---
 drivers/staging/greybus/arche-apb-ctrl.c | 10 +++++-----
 drivers/staging/greybus/arche-platform.c | 10 +++++-----
 2 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/drivers/staging/greybus/arche-apb-ctrl.c b/drivers/staging/greybus/arche-apb-ctrl.c
index 33f26a65f..19a6e59b6 100644
--- a/drivers/staging/greybus/arche-apb-ctrl.c
+++ b/drivers/staging/greybus/arche-apb-ctrl.c
@@ -300,16 +300,16 @@ static ssize_t state_show(struct device *dev,
 
 	switch (apb->state) {
 	case ARCHE_PLATFORM_STATE_OFF:
-		return sprintf(buf, "off%s\n",
+		return sysfs_emit(buf, "off%s\n",
 				apb->init_disabled ? ",disabled" : "");
 	case ARCHE_PLATFORM_STATE_ACTIVE:
-		return sprintf(buf, "active\n");
+		return sysfs_emit(buf, "active\n");
 	case ARCHE_PLATFORM_STATE_STANDBY:
-		return sprintf(buf, "standby\n");
+		return sysfs_emit(buf, "standby\n");
 	case ARCHE_PLATFORM_STATE_FW_FLASHING:
-		return sprintf(buf, "fw_flashing\n");
+		return sysfs_emit(buf, "fw_flashing\n");
 	default:
-		return sprintf(buf, "unknown state\n");
+		return sysfs_emit(buf, "unknown state\n");
 	}
 }
 
diff --git a/drivers/staging/greybus/arche-platform.c b/drivers/staging/greybus/arche-platform.c
index f669a7e2e..de5de59ea 100644
--- a/drivers/staging/greybus/arche-platform.c
+++ b/drivers/staging/greybus/arche-platform.c
@@ -374,15 +374,15 @@ static ssize_t state_show(struct device *dev,
 
 	switch (arche_pdata->state) {
 	case ARCHE_PLATFORM_STATE_OFF:
-		return sprintf(buf, "off\n");
+		return sysfs_emit(buf, "off\n");
 	case ARCHE_PLATFORM_STATE_ACTIVE:
-		return sprintf(buf, "active\n");
+		return sysfs_emit(buf, "active\n");
 	case ARCHE_PLATFORM_STATE_STANDBY:
-		return sprintf(buf, "standby\n");
+		return sysfs_emit(buf, "standby\n");
 	case ARCHE_PLATFORM_STATE_FW_FLASHING:
-		return sprintf(buf, "fw_flashing\n");
+		return sysfs_emit(buf, "fw_flashing\n");
 	default:
-		return sprintf(buf, "unknown state\n");
+		return sysfs_emit(buf, "unknown state\n");
 	}
 }
 
-- 
2.43.0

Re: [PATCH v2] staging: greybus: arche: use sysfs_emit() instead of sprintf()

[Dan Carpenter]

On Thu, Feb 26, 2026 at 07:48:58AM +0000, Ruslan Valiyev wrote:
> Replace sprintf() with sysfs_emit() in state_show() sysfs attribute
> callbacks in arche-platform.c and arche-apb-ctrl.c.
> 
> Checkpatch complains about code using sprintf(). This code here is
> obviously safe as-is, but it would be more appropriate to use
> sysfs_emit().
> 
> Signed-off-by: Ruslan Valiyev <linuxoid@gmail.com>
> ---

Thanks!

Reviewed-by: Dan Carpenter <dan.carpenter@linaro.org>

regards,
dan carpenter