[PATCH net-next] ipv6: fix clang Wformat warning

[PATCH net-next] ipv6: fix clang Wformat warning

[Arnd Bergmann]

From: Arnd Bergmann <arnd@arndb.de>

When building with 'make W=1', clang warns about a mismatched
format string:

net/ipv6/ah6.c:710:4: error: format specifies type 'unsigned short' but the argument has type 'int' [-Werror,-Wformat]
                        aalg_desc->uinfo.auth.icv_fullbits/8);
                        ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/printk.h:375:34: note: expanded from macro 'pr_info'
        printk(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
                                ~~~     ^~~~~~~~~~~
net/ipv6/esp6.c:1153:5: error: format specifies type 'unsigned short' but the argument has type 'int' [-Werror,-Wformat]
                                aalg_desc->uinfo.auth.icv_fullbits / 8);
                                ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/printk.h:375:34: note: expanded from macro 'pr_info'
        printk(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
                                ~~~     ^~~~~~~~~~~

Here, the result of dividing a 16-bit number by a 32-bit number
produces a 32-bit result, which is printed as a 16-bit integer.

Change the %hu format to the normal %u, which has the same effect
but avoids the warning.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 net/ipv6/ah6.c  | 2 +-
 net/ipv6/esp6.c | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/ipv6/ah6.c b/net/ipv6/ah6.c
index 440080da805b..01c638f5d8b8 100644
--- a/net/ipv6/ah6.c
+++ b/net/ipv6/ah6.c
@@ -705,7 +705,7 @@ static int ah6_init_state(struct xfrm_state *x)
 
 	if (aalg_desc->uinfo.auth.icv_fullbits/8 !=
 	    crypto_ahash_digestsize(ahash)) {
-		pr_info("AH: %s digestsize %u != %hu\n",
+		pr_info("AH: %s digestsize %u != %u\n",
 			x->aalg->alg_name, crypto_ahash_digestsize(ahash),
 			aalg_desc->uinfo.auth.icv_fullbits/8);
 		goto error;
diff --git a/net/ipv6/esp6.c b/net/ipv6/esp6.c
index 153ad103ba74..831a588b04a2 100644
--- a/net/ipv6/esp6.c
+++ b/net/ipv6/esp6.c
@@ -1147,7 +1147,7 @@ static int esp_init_authenc(struct xfrm_state *x)
 		err = -EINVAL;
 		if (aalg_desc->uinfo.auth.icv_fullbits / 8 !=
 		    crypto_aead_authsize(aead)) {
-			pr_info("ESP: %s digestsize %u != %hu\n",
+			pr_info("ESP: %s digestsize %u != %u\n",
 				x->aalg->alg_name,
 				crypto_aead_authsize(aead),
 				aalg_desc->uinfo.auth.icv_fullbits / 8);
-- 
2.29.2

Re: [PATCH net-next] ipv6: fix clang Wformat warning

[Steffen Klassert]

On Mon, Mar 22, 2021 at 12:56:49PM +0100, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@arndb.de>
> 
> When building with 'make W=1', clang warns about a mismatched
> format string:
> 
> net/ipv6/ah6.c:710:4: error: format specifies type 'unsigned short' but the argument has type 'int' [-Werror,-Wformat]
>                         aalg_desc->uinfo.auth.icv_fullbits/8);
>                         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> include/linux/printk.h:375:34: note: expanded from macro 'pr_info'
>         printk(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
>                                 ~~~     ^~~~~~~~~~~
> net/ipv6/esp6.c:1153:5: error: format specifies type 'unsigned short' but the argument has type 'int' [-Werror,-Wformat]
>                                 aalg_desc->uinfo.auth.icv_fullbits / 8);
>                                 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> include/linux/printk.h:375:34: note: expanded from macro 'pr_info'
>         printk(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
>                                 ~~~     ^~~~~~~~~~~
> 
> Here, the result of dividing a 16-bit number by a 32-bit number
> produces a 32-bit result, which is printed as a 16-bit integer.
> 
> Change the %hu format to the normal %u, which has the same effect
> but avoids the warning.
> 
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Applied to ipsec-next, thanks!