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

- From: Steffen Klassert \<steffen.klassert@secunet.com\>
- Date: 2021-03-26 10:29:41 
- List: netdev
- Page: https://ratatoskr.run/netdev/2021/03/6316515
- Thread: https://ratatoskr.run/netdev/2021/03/6310027/t.md

```text
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!
```