[v4] net: dsa: lan9303: use ethtool_puts() for lan9303_get_strings()

Commit Message

Justin Stitt April 25, 2024, 1:19 a.m. UTC

This pattern of strncpy with some pointer arithmetic setting fixed-sized
intervals with string literal data is a bit weird so let's use
ethtool_puts() as this has more obvious behavior and is less-error
prone.

Nicely, we also get to drop a usage of the now deprecated strncpy() [1].

Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
Link: https://github.com/KSPP/linux/issues/90
Cc: [e-mail]
Cc: Kees Cook <[e-mail]>
Suggested-by: Alexander Lobakin <[e-mail]>
Reviewed-by: Kees Cook <[e-mail]>
Signed-off-by: Justin Stitt <[e-mail]>
---
Changes in v4:
- drop unnecessary { } (thanks Alexander L.)
- carry Kees' RB because of trivial change
- Link to v3: https://lore.kernel.org/r/2[e-mail]

Changes in v3:
- use ethtool_puts over ethtool_sprintf
- Link to v2: https://lore.kernel.org/r/2[e-mail]

Changes in v2:
- use ethtool_sprintf (thanks Alexander)
- Link to v1: https://lore.kernel.org/r/2[e-mail]
---
 drivers/net/dsa/lan9303-core.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)


---
base-commit: c85af715cac0a951eea97393378e84bb49384734
change-id: 20231005-strncpy-drivers-net-dsa-lan9303-core-c-6386858e5c22

Best regards,
--
Justin Stitt <[e-mail]>

Comments

[e-mail] April 26, 2024, 7:50 p.m. UTC | #1

Hello:

This patch was applied to netdev/net-next.git (main)
by Jakub Kicinski <[e-mail]>:

On Thu, 25 Apr 2024 01:19:13 +0000 you wrote:
> This pattern of strncpy with some pointer arithmetic setting fixed-sized
> intervals with string literal data is a bit weird so let's use
> ethtool_puts() as this has more obvious behavior and is less-error
> prone.
> 
> Nicely, we also get to drop a usage of the now deprecated strncpy() [1].
> 
> [...]

Here is the summary with links:
  - [v4] net: dsa: lan9303: use ethtool_puts() for lan9303_get_strings()
    https://git.kernel.org/netdev/net-next/c/8880e2666fa8

You are awesome, thank you!

Patch

diff --git a/drivers/net/dsa/lan9303-core.c b/drivers/net/dsa/lan9303-core.c
index fcb20eac332a..f3b50adae865 100644
--- a/drivers/net/dsa/lan9303-core.c
+++ b/drivers/net/dsa/lan9303-core.c
@@ -1007,15 +1007,14 @@  static const struct lan9303_mib_desc lan9303_mib[] = {
 static void lan9303_get_strings(struct dsa_switch *ds, int port,
 				u32 stringset, uint8_t *data)
 {
+	u8 *buf = data;
 	unsigned int u;
 
 	if (stringset != ETH_SS_STATS)
 		return;
 
-	for (u = 0; u < ARRAY_SIZE(lan9303_mib); u++) {
-		strncpy(data + u * ETH_GSTRING_LEN, lan9303_mib[u].name,
-			ETH_GSTRING_LEN);
-	}
+	for (u = 0; u < ARRAY_SIZE(lan9303_mib); u++)
+		ethtool_puts(&buf, lan9303_mib[u].name);
 }
 
 static void lan9303_get_ethtool_stats(struct dsa_switch *ds, int port,