[PATCH] PM: Replace snprintf() with scnprintf() in show_trace_dev_match()

[PATCH] PM: Replace snprintf() with scnprintf() in show_trace_dev_match()

[Kaushlendra Kumar]

Replace snprintf() with scnprintf() in show_trace_dev_match() to simplify
buffer length handling. The scnprintf() function returns the number of
characters actually written (excluding the null terminator), which
eliminates the need for manual length checking and clamping.

This change removes the redundant size check since scnprintf() guarantees
that the return value will never exceed the buffer size, making the code
cleaner and less error-prone.

Signed-off-by: Kaushlendra Kumar <kaushlendra.kumar@intel.com>
---
 drivers/base/power/trace.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/base/power/trace.c b/drivers/base/power/trace.c
index cd6e559648b2..d8da7195bb00 100644
--- a/drivers/base/power/trace.c
+++ b/drivers/base/power/trace.c
@@ -238,10 +238,8 @@ int show_trace_dev_match(char *buf, size_t size)
 		unsigned int hash = hash_string(DEVSEED, dev_name(dev),
 						DEVHASH);
 		if (hash == value) {
-			int len = snprintf(buf, size, "%s\n",
+			int len = scnprintf(buf, size, "%s\n",
 					    dev_driver_string(dev));
-			if (len > size)
-				len = size;
 			buf += len;
 			ret += len;
 			size -= len;
-- 
2.34.1

Re: [PATCH] PM: Replace snprintf() with scnprintf() in show_trace_dev_match()

[Rafael J. Wysocki]

On Mon, Sep 22, 2025 at 7:54 AM Kaushlendra Kumar
<kaushlendra.kumar@intel.com> wrote:
>
> Replace snprintf() with scnprintf() in show_trace_dev_match() to simplify
> buffer length handling. The scnprintf() function returns the number of
> characters actually written (excluding the null terminator), which
> eliminates the need for manual length checking and clamping.
>
> This change removes the redundant size check since scnprintf() guarantees
> that the return value will never exceed the buffer size, making the code
> cleaner and less error-prone.
>
> Signed-off-by: Kaushlendra Kumar <kaushlendra.kumar@intel.com>
> ---
>  drivers/base/power/trace.c | 4 +---
>  1 file changed, 1 insertion(+), 3 deletions(-)
>
> diff --git a/drivers/base/power/trace.c b/drivers/base/power/trace.c
> index cd6e559648b2..d8da7195bb00 100644
> --- a/drivers/base/power/trace.c
> +++ b/drivers/base/power/trace.c
> @@ -238,10 +238,8 @@ int show_trace_dev_match(char *buf, size_t size)
>                 unsigned int hash = hash_string(DEVSEED, dev_name(dev),
>                                                 DEVHASH);
>                 if (hash == value) {
> -                       int len = snprintf(buf, size, "%s\n",
> +                       int len = scnprintf(buf, size, "%s\n",
>                                             dev_driver_string(dev));
> -                       if (len > size)
> -                               len = size;
>                         buf += len;
>                         ret += len;
>                         size -= len;
> --

Applied as 6.19 material, thanks!