Re: [PATCH v2] net: ipv4: fix clang -Wformat warnings

[Steffen Klassert]

On Fri, Jul 08, 2022 at 05:37:04PM -0700, Justin Stitt wrote:
> When building with Clang we encounter these warnings:
> | net/ipv4/ah4.c:513:4: error: format specifies type 'unsigned short' but
> | the argument has type 'int' [-Werror,-Wformat]
> | aalg_desc->uinfo.auth.icv_fullbits / 8);
> -
> | net/ipv4/esp4.c:1114:5: error: format specifies type 'unsigned short'
> | but the argument has type 'int' [-Werror,-Wformat]
> | aalg_desc->uinfo.auth.icv_fullbits / 8);
> 
> `aalg_desc->uinfo.auth.icv_fullbits` is a u16 but due to default
> argument promotion becomes an int.
> 
> Variadic functions (printf-like) undergo default argument promotion.
> Documentation/core-api/printk-formats.rst specifically recommends using
> the promoted-to-type's format flag.
> 
> As per C11 6.3.1.1:
> (https://www.open-std.org/jtc1/sc22/wg14/www/docs/n1548.pdf) `If an int
> can represent all values of the original type ..., the value is
> converted to an int; otherwise, it is converted to an unsigned int.
> These are called the integer promotions.` Thus it makes sense to change
> %hu to %d not only to follow this standard but to suppress the warning
> as well.
> 
> Link: https://github.com/ClangBuiltLinux/linux/issues/378
> Signed-off-by: Justin Stitt <justinstitt@xxxxxxxxxx>
> Suggested-by: Joe Perches <joe@xxxxxxxxxxx>
> Suggested-by: Nathan Chancellor <nathan@xxxxxxxxxx>
> Suggested-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>

Applied to the ipsec tree, thanks a lot!