Re: [PATCH v2 1/1] scsi: ufs: Fix unexpected values get from ufshcd_read_desc_param()

[Can Guo]

On 2020-10-26 13:22, Avri Altman wrote:
> > On 2020-10-22 14:37, Avri Altman wrote:
> > >> Since WB feature has been added, WB related sysfs entries can be
> > >> accessed
> > >> even when an UFS device does not support WB feature. In that case, the
> > >> descriptors which are not supported by the UFS device may be wrongly
> > >> reported when they are accessed from their corrsponding sysfs entries.
> > >> Fix it by adding a sanity check of parameter offset against the actual
> > >> decriptor length.s
> > > This should be a bug fix IMO, and be dealt with similarly like
> > > ufshcd_is_wb_attrs or ufshcd_is_wb_flag.
> > > Thanks,
> > > Avri
> >
> > Could you please elaborate on ufshcd_is_wb_attrs or ufshcd_is_wb_flag?
> > Sorry that I don't quite get it.
> Since this change is only protecting illegal access from sysfs entries,
> I am suggesting to handle it there, just like ufshcd_is_wb_attrs or
> ufshcd_is_wb_flag
> Are doing it for flags and attributes.
>
> Thanks,
> Avri

This is a general problem - if later we have HPB entries added into 
sysfs,
we will hit it again. We cannot keep adding checks like 
ufshcd_is_xxx_attrs
or ufshcd_is_xxx_flag to block them, right?

Thanks,

Can Guo.