[PATCH] capability: erase checker warnings about struct __user_cap_data_struct

[PATCH] capability: erase checker warnings about struct __user_cap_data_struct

[GONG, Ruiqi]

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@huaweicloud.com>
---
 include/uapi/linux/capability.h | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/include/uapi/linux/capability.h b/include/uapi/linux/capability.h
index 3d61a0ae055d..5bb906098697 100644
--- a/include/uapi/linux/capability.h
+++ b/include/uapi/linux/capability.h
@@ -41,11 +41,12 @@ typedef struct __user_cap_header_struct {
 	int pid;
 } __user *cap_user_header_t;
 
-typedef struct __user_cap_data_struct {
+struct __user_cap_data_struct {
         __u32 effective;
         __u32 permitted;
         __u32 inheritable;
-} __user *cap_user_data_t;
+};
+typedef struct __user_cap_data_struct __user *cap_user_data_t;
 
 
 #define VFS_CAP_REVISION_MASK	0xFF000000
-- 
2.25.1

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

[Serge E. Hallyn]

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@huaweicloud.com>

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@hallyn.com>

> ---
>  include/uapi/linux/capability.h | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/include/uapi/linux/capability.h b/include/uapi/linux/capability.h
> index 3d61a0ae055d..5bb906098697 100644
> --- a/include/uapi/linux/capability.h
> +++ b/include/uapi/linux/capability.h
> @@ -41,11 +41,12 @@ typedef struct __user_cap_header_struct {
>  	int pid;
>  } __user *cap_user_header_t;
>  
> -typedef struct __user_cap_data_struct {
> +struct __user_cap_data_struct {
>          __u32 effective;
>          __u32 permitted;
>          __u32 inheritable;
> -} __user *cap_user_data_t;
> +};
> +typedef struct __user_cap_data_struct __user *cap_user_data_t;
>  
>  
>  #define VFS_CAP_REVISION_MASK	0xFF000000
> -- 
> 2.25.1

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

[Paul Moore]

On Mon, Jun 5, 2023 at 11:29 PM Serge E. Hallyn <serge@hallyn.com> 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@huaweicloud.com>
>
> 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@hallyn.com>

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

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

[Serge E. Hallyn]

On Tue, Jun 06, 2023 at 12:45:00PM -0400, Paul Moore wrote:
> On Mon, Jun 5, 2023 at 11:29 PM Serge E. Hallyn <serge@hallyn.com> 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@huaweicloud.com>
> >
> > 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@hallyn.com>
> 
> I'm guessing you would prefer if I pulled this via the LSM tree Serge?

Yes, please.

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

Thanks, will do.

If it starts happening more than once or twice a month, then I'll get my tree
into shape and start cueing up patches...

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

[Paul Moore]

On Tue, Jun 6, 2023 at 1:50 PM Serge E. Hallyn <serge@hallyn.com> wrote:
> On Tue, Jun 06, 2023 at 12:45:00PM -0400, Paul Moore wrote:
> > On Mon, Jun 5, 2023 at 11:29 PM Serge E. Hallyn <serge@hallyn.com> 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@huaweicloud.com>
> > >
> > > 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@hallyn.com>
> >
> > I'm guessing you would prefer if I pulled this via the LSM tree Serge?
>
> Yes, please.

Done, it's merged into lsm/next.

> > FWIW, if that is ever the case for future patches, just add a note
> > when you ACK something and I'll pick it up.
>
> Thanks, will do.
>
> If it starts happening more than once or twice a month, then I'll get my tree
> into shape and start cueing up patches...

No problem, as long as the patches are fairly trivial I don't mind.

-- 
paul-moore.com