Re: [PATCH] capability: erase checker warnings about struct __user_cap_data_struct

From: Paul Moore
Date: Tue Jun 06 2023 - 12:45:18 EST


On Mon, Jun 5, 2023 at 11:29 PM Serge E. Hallyn <serge@xxxxxxxxxx> wrote:
> On Fri, Jun 02, 2023 at 01:45:27PM +0800, GONG, Ruiqi wrote:
> > Currently Sparse warns the following when compiling kernel/capability.c:
> >
> > kernel/capability.c:191:35: warning: incorrect type in argument 2 (different address spaces)
> > kernel/capability.c:191:35: expected void const *from
> > kernel/capability.c:191:35: got struct __user_cap_data_struct [noderef] __user *
> > kernel/capability.c:168:14: warning: dereference of noderef expression
> > ...... (multiple noderef warnings on different locations)
> > kernel/capability.c:244:29: warning: incorrect type in argument 1 (different address spaces)
> > kernel/capability.c:244:29: expected void *to
> > kernel/capability.c:244:29: got struct __user_cap_data_struct [noderef] __user ( * )[2]
> > kernel/capability.c:247:42: warning: dereference of noderef expression
> > ...... (multiple noderef warnings on different locations)
> >
> > It seems that defining `struct __user_cap_data_struct` together with
> > `cap_user_data_t` make Sparse believe that the struct is `noderef` as
> > well. Separate their definitions to clarify their respective attributes.
> >
> > Signed-off-by: GONG, Ruiqi <gongruiqi@xxxxxxxxxxxxxxx>
>
> Seems ok.
>
> There's still so much noise in the make C=2 output even just for
> kernel/capability.c that I'm not sure it's worth it, but no
> objection.
>
> Acked-by: Serge Hallyn <serge@xxxxxxxxxx>

I'm guessing you would prefer if I pulled this via the LSM tree Serge?

FWIW, if that is ever the case for future patches, just add a note
when you ACK something and I'll pick it up.

--
paul-moore.com