Re: [PATCH v2] ubifs: Fix build errors as symbol undefined

[Sascha Hauer]

On Mon, Nov 21, 2022 at 07:18:47PM +0800, Li Hua wrote:
> With CONFIG_UBIFS_FS_AUTHENTICATION not set, the compiler can assume that
> ubifs_node_check_hash() is never true and drops the call to ubifs_bad_hash().
> Is CONFIG_CC_OPTIMIZE_FOR_SIZE enabled this optimization does not happen anymore.
> 
> So When CONFIG_UBIFS_FS and CONFIG_CC_OPTIMIZE_FOR_SIZE is enabled but
> CONFIG_UBIFS_FS_AUTHENTICATION is not set, the build errors is as followd:
>     ERROR: modpost: "ubifs_bad_hash" [fs/ubifs/ubifs.ko] undefined!
> 
> Fix it by add no-op ubifs_bad_hash() for the CONFIG_UBIFS_FS_AUTHENTICATION=n case.
> 
> Fixes: 16a26b20d2af ("ubifs: authentication: Add hashes to index nodes")
> Signed-off-by: Li Hua <hucool.lihua@xxxxxxxxxx>

Reviewed-by: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>

Sascha

> ---
>  fs/ubifs/ubifs.h | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/fs/ubifs/ubifs.h b/fs/ubifs/ubifs.h
> index 478bbbb5382f..2f1f31581094 100644
> --- a/fs/ubifs/ubifs.h
> +++ b/fs/ubifs/ubifs.h
> @@ -1623,8 +1623,13 @@ static inline int ubifs_check_hmac(const struct ubifs_info *c,
>  	return crypto_memneq(expected, got, c->hmac_desc_len);
>  }
>  
> +#ifdef CONFIG_UBIFS_FS_AUTHENTICATION
>  void ubifs_bad_hash(const struct ubifs_info *c, const void *node,
>  		    const u8 *hash, int lnum, int offs);
> +#else
> +static inline void ubifs_bad_hash(const struct ubifs_info *c, const void *node,
> +				  const u8 *hash, int lnum, int offs) {};
> +#endif
>  
>  int __ubifs_node_check_hash(const struct ubifs_info *c, const void *buf,
>  			  const u8 *expected);
> -- 
> 2.17.1
> 
> 

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