linux-kernel - Re: [PATCH] Removing deprecated strncpy()

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Message-ID: <20250410115404.8774F32-hca@linux.ibm.com>
Date: Thu, 10 Apr 2025 13:54:04 +0200
From: Heiko Carstens <hca@...ux.ibm.com>
To: Kevin Paul Reddy Janagari <kevinpaul468@...il.com>
Cc: gor@...ux.ibm.com, agordeev@...ux.ibm.com, borntraeger@...ux.ibm.com,
        svens@...ux.ibm.com, linux-s390@...r.kernel.org,
        linux-kernel@...r.kernel.org, skhan@...uxfoundation.org
Subject: Re: [PATCH] Removing deprecated strncpy()

On Thu, Apr 10, 2025 at 05:02:30PM +0530, Kevin Paul Reddy Janagari wrote:
> This patch suggests the replacement of strncpy with strscpy
> as per the Documentation/process/deprecated
> the strncpy() fails to guarntee NULL termination
> since the function adds zero pads, this isn't really convenient
> for short strings as it may cause performce issues
> 
> strscpy() is a preffered replacement because
> it overcomes the limitations of strncpy as mentioned above
> 
> Signed-off-by: Kevin Paul Reddy Janagari <kevinpaul468@...il.com>
> ---
>  arch/s390/boot/printk.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/s390/boot/printk.c b/arch/s390/boot/printk.c
> index 8cf6331bc060..8f3b2244ef1b 100644
> --- a/arch/s390/boot/printk.c
> +++ b/arch/s390/boot/printk.c
> @@ -158,7 +158,7 @@ static noinline char *strsym(char *buf, void *ip)
>  
>  	p = findsym((unsigned long)ip, &off, &len);
>  	if (p) {
> -		strncpy(buf, p, MAX_SYMLEN);
> +		strscpy(buf, p, MAX_SYMLEN);

This won't even compile. Please compile test before sending any patches.