[PATCH] powerpc: replace strlcat to simplify ppc_kallsyms_lookup_name

[PATCH] powerpc: replace strlcat to simplify ppc_kallsyms_lookup_name

[Thorsten Blum]

strlcat() should not be used anymore (see fortify-string.h), and since
name is guaranteed to be NUL-terminated within KSYM_NAME_LEN bytes, use
memcpy() instead.

Rename dot_appended to the semantically clearer prepend_dot while at it.

Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
---
 arch/powerpc/include/asm/text-patching.h | 17 ++++++++---------
 1 file changed, 8 insertions(+), 9 deletions(-)

diff --git a/arch/powerpc/include/asm/text-patching.h b/arch/powerpc/include/asm/text-patching.h
index e7f14720f630..c47b813bd067 100644
--- a/arch/powerpc/include/asm/text-patching.h
+++ b/arch/powerpc/include/asm/text-patching.h
@@ -227,22 +227,21 @@ static inline unsigned long ppc_kallsyms_lookup_name(const char *name)
 #ifdef CONFIG_PPC64_ELF_ABI_V1
 	/* check for dot variant */
 	char dot_name[1 + KSYM_NAME_LEN];
-	bool dot_appended = false;
+	bool prepend_dot = name[0] != '.';
+	size_t len = strnlen(name, KSYM_NAME_LEN);
 
-	if (strnlen(name, KSYM_NAME_LEN) >= KSYM_NAME_LEN)
+	if (len == KSYM_NAME_LEN)
 		return 0;
 
-	if (name[0] != '.') {
+	if (prepend_dot) {
 		dot_name[0] = '.';
-		dot_name[1] = '\0';
-		strlcat(dot_name, name, sizeof(dot_name));
-		dot_appended = true;
+		memcpy(dot_name + 1, name, len + 1);
 	} else {
-		dot_name[0] = '\0';
-		strlcat(dot_name, name, sizeof(dot_name));
+		memcpy(dot_name, name, len + 1);
 	}
+
 	addr = kallsyms_lookup_name(dot_name);
-	if (!addr && dot_appended)
+	if (!addr && prepend_dot)
 		/* Let's try the original non-dot symbol lookup	*/
 		addr = kallsyms_lookup_name(name);
 #elif defined(CONFIG_PPC64_ELF_ABI_V2)

Re: [PATCH] powerpc: replace strlcat to simplify ppc_kallsyms_lookup_name

[Christophe Leroy (CS GROUP)]

Le 08/06/2026 à 21:32, Thorsten Blum a écrit :
> strlcat() should not be used anymore (see fortify-string.h), and since
> name is guaranteed to be NUL-terminated within KSYM_NAME_LEN bytes, use
> memcpy() instead.
> 
> Rename dot_appended to the semantically clearer prepend_dot while at it.
> 
> Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>

Please take 
https://patchwork.ozlabs.org/project/linuxppc-dev/patch/20260506021143.13797-1-xieyuanbin1@huawei.com/ 
instead

Christophe


> ---
>   arch/powerpc/include/asm/text-patching.h | 17 ++++++++---------
>   1 file changed, 8 insertions(+), 9 deletions(-)
> 
> diff --git a/arch/powerpc/include/asm/text-patching.h b/arch/powerpc/include/asm/text-patching.h
> index e7f14720f630..c47b813bd067 100644
> --- a/arch/powerpc/include/asm/text-patching.h
> +++ b/arch/powerpc/include/asm/text-patching.h
> @@ -227,22 +227,21 @@ static inline unsigned long ppc_kallsyms_lookup_name(const char *name)
>   #ifdef CONFIG_PPC64_ELF_ABI_V1
>   	/* check for dot variant */
>   	char dot_name[1 + KSYM_NAME_LEN];
> -	bool dot_appended = false;
> +	bool prepend_dot = name[0] != '.';
> +	size_t len = strnlen(name, KSYM_NAME_LEN);
>   
> -	if (strnlen(name, KSYM_NAME_LEN) >= KSYM_NAME_LEN)
> +	if (len == KSYM_NAME_LEN)
>   		return 0;
>   
> -	if (name[0] != '.') {
> +	if (prepend_dot) {
>   		dot_name[0] = '.';
> -		dot_name[1] = '\0';
> -		strlcat(dot_name, name, sizeof(dot_name));
> -		dot_appended = true;
> +		memcpy(dot_name + 1, name, len + 1);
>   	} else {
> -		dot_name[0] = '\0';
> -		strlcat(dot_name, name, sizeof(dot_name));
> +		memcpy(dot_name, name, len + 1);
>   	}
> +
>   	addr = kallsyms_lookup_name(dot_name);
> -	if (!addr && dot_appended)
> +	if (!addr && prepend_dot)
>   		/* Let's try the original non-dot symbol lookup	*/
>   		addr = kallsyms_lookup_name(name);
>   #elif defined(CONFIG_PPC64_ELF_ABI_V2)