Re: [PATCH v3][next] NFSD: Avoid multiple -Wflex-array-member-not-at-end warnings

[Jeff Layton <jlayton@kernel.org>]

On Mon, 2025-06-16 at 16:31 -0600, Gustavo A. R. Silva wrote:
> Replace flexible-array member with a fixed-size array.
> 
> With this changes, fix many instances of the following type of
> warnings:
> 
> fs/nfsd/nfsfh.h:79:33: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
> fs/nfsd/state.h:763:33: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
> fs/nfsd/state.h:669:33: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
> fs/nfsd/state.h:549:33: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
> fs/nfsd/xdr4.h:705:33: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
> fs/nfsd/xdr4.h:678:33: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
> 
> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
> ---
> Changes in v3:
>  - Replace flexible-array member with a fixed-size array. (NeilBrown)
> 
> Changes in v2:
>  - Use indices into `fh_raw`. (Christoph)
>  - Remove union and flexible-array member `fh_fsid`. (Christoph)
>  - Link: https://lore.kernel.org/linux-hardening/aEoKCuQ1YDs2Ivn0@kspp/
> 
> v1:
>  - Link: https://lore.kernel.org/linux-hardening/aBp37ZXBJM09yAXp@kspp/
> 
>  fs/nfsd/nfsfh.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/fs/nfsd/nfsfh.h b/fs/nfsd/nfsfh.h
> index 5103c2f4d225..760e77f3630b 100644
> --- a/fs/nfsd/nfsfh.h
> +++ b/fs/nfsd/nfsfh.h
> @@ -56,7 +56,7 @@ struct knfsd_fh {
>  			u8		fh_auth_type;	/* deprecated */
>  			u8		fh_fsid_type;
>  			u8		fh_fileid_type;
> -			u32		fh_fsid[]; /* flexible-array member */
> +			u32		fh_fsid[NFS4_FHSIZE / 4 - 1];
>  		};
>  	};
>  };

Reviewed-by: Jeff Layton <jlayton@kernel.org>