Re: [PATCH] staging: r8188eu: Use flexible-array for one length array member

[Deepak R Varma]

On Fri, Oct 28, 2022 at 05:03:25PM +0300, Pavel Skripkin wrote:
> Hi Deepak R,
>
> Deepak R Varma <drv@xxxxxxxxx> says:
> > Flexible-array member should be used instead of one or zero member to
> > meet the need for having a dynamically sized trailing elements in a
> > structure. Refer to links [1] and [2] for detailed guidance on this
> > suggestion.
> >
> > [1] https://en.wikipedia.org/wiki/Flexible_array_member
> > [2] https://www.kernel.org/doc/html/v5.16/process/deprecated.html#zero-length-and-one-element-arrays
> >
> > Issue identified using coccicheck.
> >
> > Signed-off-by: Deepak R Varma <drv@xxxxxxxxx>
> > ---
> >   drivers/staging/r8188eu/include/odm.h         | 2 +-
> >   drivers/staging/r8188eu/include/wlan_bssdef.h | 6 +++---
> >   2 files changed, 4 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/staging/r8188eu/include/odm.h b/drivers/staging/r8188eu/include/odm.h
> > index 89b01dd614ba..e2a9de5b9323 100644
> > --- a/drivers/staging/r8188eu/include/odm.h
> > +++ b/drivers/staging/r8188eu/include/odm.h
> > @@ -166,7 +166,7 @@ struct odm_ra_info {
> >
> >   struct ijk_matrix_regs_set {
> >   	bool	bIQKDone;
> > -	s32	Value[1][IQK_Matrix_REG_NUM];
> > +	s32	Value[][IQK_Matrix_REG_NUM];
> >   };
> >
>
> you are changing the actual size of the struct. Wondering if you have tested
> this patch somehow

Hello Pavel,
Thank you for reviewing the patch. I build the module post making the changes an
ensured that the build is successful. However, I am not sure how to check the
changes I am proposing. Could you please direct me to some information on how to
test patches? Is there some documentation generic/driver-specific that I can
refer to?

>
> >   struct odm_rf_cal {
> > diff --git a/drivers/staging/r8188eu/include/wlan_bssdef.h b/drivers/staging/r8188eu/include/wlan_bssdef.h
> > index 831c465df500..33177de194eb 100644
> > --- a/drivers/staging/r8188eu/include/wlan_bssdef.h
> > +++ b/drivers/staging/r8188eu/include/wlan_bssdef.h
> > @@ -179,7 +179,7 @@ struct ndis_802_11_status_ind {
> >
> >   struct ndis_802_11_auth_evt {
> >   	struct ndis_802_11_status_ind       Status;
> > -	struct ndis_802_11_auth_req  Request[1];
> > +	struct ndis_802_11_auth_req  Request[];
> >   };
> >
>
> this structure seems to be unused. Better to remove it instead of
> maintaining the old code

Sounds good. I agree and will do as suggested.

>
> >   struct ndis_802_11_test {
> > @@ -291,7 +291,7 @@ struct pmkid_candidate {
> >   struct ndis_802_11_pmkid_list {
> >   	u32 Version;       /*  Version of the structure */
> >   	u32 NumCandidates; /*  No. of pmkid candidates */
> > -	struct pmkid_candidate CandidateList[1];
> > +	struct pmkid_candidate CandidateList[];
> >   };
>
> this one as well

Yes, same here.

>
> >
> >   struct ndis_802_11_auth_encrypt {
> > @@ -304,7 +304,7 @@ struct ndis_802_11_cap {
> >   	u32  Version;
> >   	u32  NoOfPMKIDs;
> >   	u32  NoOfAuthEncryptPairsSupported;
> > -	struct ndis_802_11_auth_encrypt AuthenticationEncryptionSupported[1];
> > +	struct ndis_802_11_auth_encrypt AuthenticationEncryptionSupported[];
> >   };
> >
> >   u8 key_2char2num(u8 hch, u8 lch);
> > --
> > 2.34.1
> >
>
> and this one as well

Yes, will do.

Thank you again for your feedback and suggestions.

./drv

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> With regards,
> Pavel Skripkin
>