[PATCH] Removing deprecated strncpy()

[PATCH] Removing deprecated strncpy()

[Kevin Paul Reddy Janagari]

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@gmail.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);
 		/* reserve 15 bytes for offset/len in symbol+0x1234/0x1234 */
 		p = buf + strnlen(buf, MAX_SYMLEN - 15);
 		strcpy(p, "+0x");
-- 
2.39.5

Re: [PATCH] Removing deprecated strncpy()

[Heiko Carstens]

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@gmail.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.

[PATCH] Removing deprecated strncpy()

[Kevin Paul Reddy Janagari]

This patch suggests the replacement of strncpy with strscpy
as per Documentation/process/deprecated.
The strncpy() fails to guarntee NULL termination,
The function adds zero pads which 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 mentioned above

Compile Tested
Signed-off-by: Kevin Paul Reddy Janagari <kevinpaul468@gmail.com>
---
 net/tipc/link.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/tipc/link.c b/net/tipc/link.c
index 50c2e0846ea4..4859b3ccc094 100644
--- a/net/tipc/link.c
+++ b/net/tipc/link.c
@@ -2227,7 +2227,7 @@ static int tipc_link_proto_rcv(struct tipc_link *l, struct sk_buff *skb,
 			break;
 		if (msg_data_sz(hdr) < TIPC_MAX_IF_NAME)
 			break;
-		strncpy(if_name, data, TIPC_MAX_IF_NAME);
+		strscpy(if_name, data, TIPC_MAX_IF_NAME);
 
 		/* Update own tolerance if peer indicates a non-zero value */
 		if (tipc_in_range(peers_tol, TIPC_MIN_LINK_TOL, TIPC_MAX_LINK_TOL)) {
-- 
2.39.5

RE: [PATCH] Removing deprecated strncpy()

[Tung Quang Nguyen]

>which isn't really convenient for short strings as it may cause performce issues
Typo: /performce/performance
Also please append net-next to [PATCH] in your email subject.
>
>strscpy() is a preffered replacement because it overcomes the limitations of
>strncpy mentioned above
>
>Compile Tested
>Signed-off-by: Kevin Paul Reddy Janagari <kevinpaul468@gmail.com>
>---
> net/tipc/link.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
>diff --git a/net/tipc/link.c b/net/tipc/link.c index 50c2e0846ea4..4859b3ccc094
>100644
>--- a/net/tipc/link.c
>+++ b/net/tipc/link.c
>@@ -2227,7 +2227,7 @@ static int tipc_link_proto_rcv(struct tipc_link *l, struct
>sk_buff *skb,
> 			break;
> 		if (msg_data_sz(hdr) < TIPC_MAX_IF_NAME)
> 			break;
>-		strncpy(if_name, data, TIPC_MAX_IF_NAME);
>+		strscpy(if_name, data, TIPC_MAX_IF_NAME);
Could you please do the same replacement in function tipc_node_get_linkname() (node.c) ?

>
> 		/* Update own tolerance if peer indicates a non-zero value */
> 		if (tipc_in_range(peers_tol, TIPC_MIN_LINK_TOL,
>TIPC_MAX_LINK_TOL)) {
>--
>2.39.5
>

[PATCH] Removing deprecated strncpy()

[Kevin Paul Reddy Janagari]

This patch suggests the replacement of strncpy with strscpy
as per Documentation/process/deprecated.
The strncpy() fails to guarntee NULL termination,
The function adds zero pads which 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 mentioned above

Compile Tested

Signed-off-by: Kevin Paul Reddy Janagari <kevinpaul468@gmail.com>
---
 net/tipc/node.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/tipc/node.c b/net/tipc/node.c
index ccf5e427f43e..cb43f2016a70 100644
--- a/net/tipc/node.c
+++ b/net/tipc/node.c
@@ -1581,7 +1581,7 @@ int tipc_node_get_linkname(struct net *net, u32 bearer_id, u32 addr,
 	tipc_node_read_lock(node);
 	link = node->links[bearer_id].link;
 	if (link) {
-		strncpy(linkname, tipc_link_name(link), len);
+		strscpy(linkname, tipc_link_name(link), len);
 		err = 0;
 	}
 	tipc_node_read_unlock(node);
-- 
2.39.5

RE: [PATCH] Removing deprecated strncpy()

[Tung Quang Nguyen]

>This patch suggests the replacement of strncpy with strscpy as per
>Documentation/process/deprecated.
>The strncpy() fails to guarntee NULL termination, The function adds zero pads
>which 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 mentioned above
>
Please read my comment for your previous patch:
- Add "net-next" to your email subject like this: [PATCH net-next]
- Fix many typos in your changelog:  guarntee -> guarantee, performce --> performance, preffered --> preferred
>Compile Tested
>
>Signed-off-by: Kevin Paul Reddy Janagari <kevinpaul468@gmail.com>
>---
> net/tipc/node.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
>diff --git a/net/tipc/node.c b/net/tipc/node.c index
>ccf5e427f43e..cb43f2016a70 100644
>--- a/net/tipc/node.c
>+++ b/net/tipc/node.c
>@@ -1581,7 +1581,7 @@ int tipc_node_get_linkname(struct net *net, u32
>bearer_id, u32 addr,
> 	tipc_node_read_lock(node);
> 	link = node->links[bearer_id].link;
> 	if (link) {
>-		strncpy(linkname, tipc_link_name(link), len);
>+		strscpy(linkname, tipc_link_name(link), len);
please merge this change into your previous patch. We do not need a separate patch for the same purpose.