[PATCH 1/2] powerpc/powernv: Avoid strlen() in pnv_restart()

[PATCH 1/2] powerpc/powernv: Avoid strlen() in pnv_restart()

[Thorsten Blum]

Check only the first byte instead of scanning the entire string with
strlen().

Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
---
 arch/powerpc/platforms/powernv/setup.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/platforms/powernv/setup.c b/arch/powerpc/platforms/powernv/setup.c
index 06ed5e2aa265..2af92e7ba4ee 100644
--- a/arch/powerpc/platforms/powernv/setup.c
+++ b/arch/powerpc/platforms/powernv/setup.c
@@ -312,7 +312,7 @@ static void  __noreturn pnv_restart(char *cmd)
 	pnv_prepare_going_down();
 
 	do {
-		if (!cmd || !strlen(cmd))
+		if (!cmd || *cmd == '\0')
 			rc = opal_cec_reboot();
 		else if (strcmp(cmd, "full") == 0)
 			rc = opal_cec_reboot2(OPAL_REBOOT_FULL_IPL, NULL);

[PATCH 2/2] powerpc/pseries: Avoid strlen() in do_{remove,update}_property()

[Thorsten Blum]

Check only the first byte instead of scanning the entire string with
strlen().

Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
---
 arch/powerpc/platforms/pseries/reconfig.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/platforms/pseries/reconfig.c b/arch/powerpc/platforms/pseries/reconfig.c
index 7faebcffc9df..18e3f1a036e3 100644
--- a/arch/powerpc/platforms/pseries/reconfig.c
+++ b/arch/powerpc/platforms/pseries/reconfig.c
@@ -307,7 +307,7 @@ static int do_remove_property(char *buf, size_t bufsize)
 	if (tmp)
 		*tmp = '\0';
 
-	if (strlen(buf) == 0)
+	if (*buf == '\0')
 		return -EINVAL;
 
 	return of_remove_property(np, of_find_property(np, buf, NULL));
@@ -330,7 +330,7 @@ static int do_update_property(char *buf, size_t bufsize)
 	if (!next_prop)
 		return -EINVAL;
 
-	if (!strlen(name))
+	if (*name == '\0')
 		return -ENODEV;
 
 	newprop = new_property(name, length, value, NULL);

Re: [PATCH 2/2] powerpc/pseries: Avoid strlen() in do_{remove,update}_property()

[Christophe Leroy (CS GROUP)]

Le 21/07/2026 à 17:53, Thorsten Blum a écrit :
> Check only the first byte instead of scanning the entire string with
> strlen().
> 
> Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>

Reviewed-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>

> ---
>   arch/powerpc/platforms/pseries/reconfig.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/powerpc/platforms/pseries/reconfig.c b/arch/powerpc/platforms/pseries/reconfig.c
> index 7faebcffc9df..18e3f1a036e3 100644
> --- a/arch/powerpc/platforms/pseries/reconfig.c
> +++ b/arch/powerpc/platforms/pseries/reconfig.c
> @@ -307,7 +307,7 @@ static int do_remove_property(char *buf, size_t bufsize)
>   	if (tmp)
>   		*tmp = '\0';
>   
> -	if (strlen(buf) == 0)
> +	if (*buf == '\0')

Can use !*buf instead.

>   		return -EINVAL;
>   
>   	return of_remove_property(np, of_find_property(np, buf, NULL));
> @@ -330,7 +330,7 @@ static int do_update_property(char *buf, size_t bufsize)
>   	if (!next_prop)
>   		return -EINVAL;
>   
> -	if (!strlen(name))
> +	if (*name == '\0')

Can use !*name instead.

>   		return -ENODEV;
>   
>   	newprop = new_property(name, length, value, NULL);

Re: [PATCH 1/2] powerpc/powernv: Avoid strlen() in pnv_restart()

[Christophe Leroy (CS GROUP)]

Le 21/07/2026 à 17:53, Thorsten Blum a écrit :
> Check only the first byte instead of scanning the entire string with
> strlen().

Well, strlen() is not going to scan the entire string, it will break at 
first 0. But I agreed calling strlen() is not worth it.

> 
> Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>

Reviewed-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>

> ---
>   arch/powerpc/platforms/powernv/setup.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/powerpc/platforms/powernv/setup.c b/arch/powerpc/platforms/powernv/setup.c
> index 06ed5e2aa265..2af92e7ba4ee 100644
> --- a/arch/powerpc/platforms/powernv/setup.c
> +++ b/arch/powerpc/platforms/powernv/setup.c
> @@ -312,7 +312,7 @@ static void  __noreturn pnv_restart(char *cmd)
>   	pnv_prepare_going_down();
>   
>   	do {
> -		if (!cmd || !strlen(cmd))
> +		if (!cmd || *cmd == '\0')

Maybe !*cmd instead ?

>   			rc = opal_cec_reboot();
>   		else if (strcmp(cmd, "full") == 0)
>   			rc = opal_cec_reboot2(OPAL_REBOOT_FULL_IPL, NULL);