Re: [PATCH] tpm: aovid -Wunused-but-set-variable

[Thorsten Blum <thorsten.blum@linux.dev>]

On Fri, Mar 22, 2024 at 02:22:48PM +0100, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@arndb.de>
> 
> Outside of the EFI tpm code, the TPM_MEMREMAP()/TPM_MEMUNMAP functions are
> defined as trivial macros, leading to the mapping_size variable ending
> up unused:
> 
> In file included from drivers/char/tpm/tpm-sysfs.c:16:
> In file included from drivers/char/tpm/tpm.h:28:
> include/linux/tpm_eventlog.h:167:6: error: variable 'mapping_size' set but not used [-Werror,-Wunused-but-set-variable]
>   167 |         int mapping_size;
> 
> Turn the stubs into inline functions to avoid this warning.
> 
> Fixes: c46f3405692d ("tpm: Reserve the TPM final events table")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
>  include/linux/tpm_eventlog.h | 9 +++++++--
>  1 file changed, 7 insertions(+), 2 deletions(-)
> 
> diff --git a/include/linux/tpm_eventlog.h b/include/linux/tpm_eventlog.h
> index 7d68a5cc5881..6e5be15029fb 100644
> --- a/include/linux/tpm_eventlog.h
> +++ b/include/linux/tpm_eventlog.h
> @@ -131,11 +131,16 @@ struct tcg_algorithm_info {
>  };
>  
>  #ifndef TPM_MEMREMAP
> -#define TPM_MEMREMAP(start, size) NULL
> +static inline void *TPM_MEMREMAP(unsigned long start, size_t size)
> +{
> +	return NULL;
> +}
>  #endif
>  
>  #ifndef TPM_MEMUNMAP
> -#define TPM_MEMUNMAP(start, size) do{} while(0)
> +static inline void TPM_MEMUNMAP(void *mapping, size_t size)
> +{
> +}
>  #endif
>  
>  /**

I just stumbled upon the same problem and found this patch from 2024,
which still applies. I cc'ed the current maintainers - maybe someone can
pick this up? Thanks!

Reviewed-by: Thorsten Blum <thorsten.blum@linux.dev>