On Wed, Sep 02, 2020 at 04:40:58PM +0200, Carlos Maiolino wrote:
> nameval is a variable-size array, so, define it as it, and remove all
> the -1 magic number subtractions
>
> Signed-off-by: Carlos Maiolino <cmaiolino@xxxxxxxxxx>
> ---
> Changelog:
>
> V2:
> - Drop wrong change to XFS_ATTR_SF_ENTSIZE_MAX
>
> fs/xfs/libxfs/xfs_attr_leaf.c | 6 ++----
> fs/xfs/libxfs/xfs_attr_sf.h | 4 ++--
> fs/xfs/libxfs/xfs_da_format.h | 2 +-
> 3 files changed, 5 insertions(+), 7 deletions(-)
>
> diff --git a/fs/xfs/libxfs/xfs_attr_leaf.c b/fs/xfs/libxfs/xfs_attr_leaf.c
> index d920183b08a99..89193871e6a7f 100644
> --- a/fs/xfs/libxfs/xfs_attr_leaf.c
> +++ b/fs/xfs/libxfs/xfs_attr_leaf.c
> @@ -992,7 +992,7 @@ xfs_attr_shortform_allfit(
> return 0;
> if (be16_to_cpu(name_loc->valuelen) >= XFS_ATTR_SF_ENTSIZE_MAX)
> return 0;
> - bytes += sizeof(struct xfs_attr_sf_entry) - 1
> + bytes += sizeof(struct xfs_attr_sf_entry)
> + name_loc->namelen
> + be16_to_cpu(name_loc->valuelen);
Isn't this an open-coded:
bytes += XFS_ATTR_SF_ENTSIZE_BYNAME(name_loc->namelen,
be16_to_cpu(name_loc->valuelen));
Otherwise this patch looks ok to me.
--D
> }
> @@ -1036,10 +1036,8 @@ xfs_attr_shortform_verify(
> * struct xfs_attr_sf_entry has a variable length.
> * Check the fixed-offset parts of the structure are
> * within the data buffer.
> - * xfs_attr_sf_entry is defined with a 1-byte variable
> - * array at the end, so we must subtract that off.
> */
> - if (((char *)sfep + sizeof(*sfep) - 1) >= endp)
> + if (((char *)sfep + sizeof(*sfep)) >= endp)
> return __this_address;
>
> /* Don't allow names with known bad length. */
> diff --git a/fs/xfs/libxfs/xfs_attr_sf.h b/fs/xfs/libxfs/xfs_attr_sf.h
> index c4afb33079184..f608a2966d7f8 100644
> --- a/fs/xfs/libxfs/xfs_attr_sf.h
> +++ b/fs/xfs/libxfs/xfs_attr_sf.h
> @@ -27,11 +27,11 @@ typedef struct xfs_attr_sf_sort {
> } xfs_attr_sf_sort_t;
>
> #define XFS_ATTR_SF_ENTSIZE_BYNAME(nlen,vlen) /* space name/value uses */ \
> - (((int)sizeof(struct xfs_attr_sf_entry)-1 + (nlen)+(vlen)))
> + (((int)sizeof(struct xfs_attr_sf_entry) + (nlen)+(vlen)))
> #define XFS_ATTR_SF_ENTSIZE_MAX /* max space for name&value */ \
> ((1 << (NBBY*(int)sizeof(uint8_t))) - 1)
> #define XFS_ATTR_SF_ENTSIZE(sfep) /* space an entry uses */ \
> - ((int)sizeof(struct xfs_attr_sf_entry)-1 + \
> + ((int)sizeof(struct xfs_attr_sf_entry) + \
> (sfep)->namelen+(sfep)->valuelen)
> #define XFS_ATTR_SF_NEXTENTRY(sfep) /* next entry in struct */ \
> ((struct xfs_attr_sf_entry *)((char *)(sfep) + \
> diff --git a/fs/xfs/libxfs/xfs_da_format.h b/fs/xfs/libxfs/xfs_da_format.h
> index e708b714bf99d..b40a4e80f5ee6 100644
> --- a/fs/xfs/libxfs/xfs_da_format.h
> +++ b/fs/xfs/libxfs/xfs_da_format.h
> @@ -589,7 +589,7 @@ struct xfs_attr_shortform {
> uint8_t namelen; /* actual length of name (no NULL) */
> uint8_t valuelen; /* actual length of value (no NULL) */
> uint8_t flags; /* flags bits (see xfs_attr_leaf.h) */
> - uint8_t nameval[1]; /* name & value bytes concatenated */
> + uint8_t nameval[]; /* name & value bytes concatenated */
> } list[1]; /* variable sized array */
> };
>
> --
> 2.26.2
>
