[vfs:master 30/32] fs/proc/fd.c:87:55: sparse: incorrect type in initializer (different base types)

[vfs:master 30/32] fs/proc/fd.c:87:55: sparse: incorrect type in initializer (different base types)

[Fengguang Wu]

Hi Cyrill,

FYI, there are new sparse warnings show up in

tree:   git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs.git master
head:   9283194882d18e3755c4ebc0b86db9f9a4f4c81a
commit: c8506285ded8009f7c1ab937fc0021c6294ba424 [30/32] procfs: Move /proc/pid/fd[info] handling code to fd.[ch]

All sparse warnings:

+ fs/proc/fd.c:87:55: sparse: incorrect type in initializer (different base types)
  fs/proc/fd.c:87:55:    expected unsigned int [unsigned] f_mode
  fs/proc/fd.c:87:55:    got restricted fmode_t [usertype] f_mode
+ fs/proc/fd.c:105:54: sparse: restricted fmode_t degrades to integer
  fs/proc/fd.c:107:54: sparse: restricted fmode_t degrades to integer

vim +87 fs/proc/fd.c
    84				rcu_read_lock();
    85				file = fcheck_files(files, fd);
    86				if (file) {
  > 87					unsigned f_mode = file->f_mode;
    88	
    89					rcu_read_unlock();
    90					put_files_struct(files);

---
0-DAY kernel build testing backend         Open Source Technology Centre
Fengguang Wu <wfg@linux.intel.com>                     Intel Corporation

Re: [vfs:master 30/32] fs/proc/fd.c:87:55: sparse: incorrect type in initializer (different base typ

[Cyrill Gorcunov]

On Mon, Aug 27, 2012 at 03:12:57AM +0800, Fengguang Wu wrote:
> Hi Cyrill,
> 
> FYI, there are new sparse warnings show up in
> 
> tree:   git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs.git master
> head:   9283194882d18e3755c4ebc0b86db9f9a4f4c81a
> commit: c8506285ded8009f7c1ab937fc0021c6294ba424 [30/32] procfs: Move /proc/pid/fd[info] handling code to fd.[ch]
> 
> All sparse warnings:
> 
> + fs/proc/fd.c:87:55: sparse: incorrect type in initializer (different base types)
>   fs/proc/fd.c:87:55:    expected unsigned int [unsigned] f_mode
>   fs/proc/fd.c:87:55:    got restricted fmode_t [usertype] f_mode
> + fs/proc/fd.c:105:54: sparse: restricted fmode_t degrades to integer
>   fs/proc/fd.c:107:54: sparse: restricted fmode_t degrades to integer
> 
> vim +87 fs/proc/fd.c
>     84				rcu_read_lock();
>     85				file = fcheck_files(files, fd);
>     86				if (file) {
>   > 87					unsigned f_mode = file->f_mode;
>     88	
>     89					rcu_read_unlock();
>     90					put_files_struct(files);

Sigh. Thanks a lot, Fengguang! This routine has been moved from base.c
(which had this nit already). Al, could you please make it unsigned int,
and push fix intou your tree?

	Cyrill

Re: [vfs:master 30/32] fs/proc/fd.c:87:55: sparse: incorrect type in initializer (different base typ

[Cyrill Gorcunov]

On Sun, Aug 26, 2012 at 11:26:20PM +0400, Cyrill Gorcunov wrote:
> On Mon, Aug 27, 2012 at 03:12:57AM +0800, Fengguang Wu wrote:
> > Hi Cyrill,
> > 
> > FYI, there are new sparse warnings show up in
> > 
> > tree:   git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs.git master
> > head:   9283194882d18e3755c4ebc0b86db9f9a4f4c81a
> > commit: c8506285ded8009f7c1ab937fc0021c6294ba424 [30/32] procfs: Move /proc/pid/fd[info] handling code to fd.[ch]
> > 
> > All sparse warnings:
> > 
> > + fs/proc/fd.c:87:55: sparse: incorrect type in initializer (different base types)
> >   fs/proc/fd.c:87:55:    expected unsigned int [unsigned] f_mode
> >   fs/proc/fd.c:87:55:    got restricted fmode_t [usertype] f_mode
> > + fs/proc/fd.c:105:54: sparse: restricted fmode_t degrades to integer
> >   fs/proc/fd.c:107:54: sparse: restricted fmode_t degrades to integer
> > 
> > vim +87 fs/proc/fd.c
> >     84				rcu_read_lock();
> >     85				file = fcheck_files(files, fd);
> >     86				if (file) {
> >   > 87					unsigned f_mode = file->f_mode;
> >     88	
> >     89					rcu_read_unlock();
> >     90					put_files_struct(files);
> 
> Sigh. Thanks a lot, Fengguang! This routine has been moved from base.c
> (which had this nit already). Al, could you please make it unsigned int,
> and push fix intou your tree?

This should fix the problem (if needed, since the next commit in series
should drop this declaration). Also this patch changes type for i_mode,
which I think a good idea.
---
From: Cyrill Gorcunov <gorcunov@openvz.org>
Subject: fs, proc: Fix sparse warning in tid_fd_revalidate

The following warnings have been caught

 | + fs/proc/fd.c:87:55:  sparse: incorrect type in initializer (different base types)
 |   fs/proc/fd.c:87:55:  expected unsigned int [unsigned] f_mode
 |   fs/proc/fd.c:87:55:  got restricted fmode_t [usertype] f_mode
 | + fs/proc/fd.c:105:54: sparse: restricted fmode_t degrades to integer
 |   fs/proc/fd.c:107:54: sparse: restricted fmode_t degrades to integer

make f_mode and i_mode declared with proper types.

Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
CC: Al Viro <viro@ZenIV.linux.org.uk>
---
 fs/proc/fd.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Index: linux-2.6.git/fs/proc/fd.c
=================================--- linux-2.6.git.orig/fs/proc/fd.c
+++ linux-2.6.git/fs/proc/fd.c
@@ -84,7 +84,7 @@ static int tid_fd_revalidate(struct dent
 			rcu_read_lock();
 			file = fcheck_files(files, fd);
 			if (file) {
-				unsigned f_mode = file->f_mode;
+				unsigned int f_mode = file->f_mode;
 
 				rcu_read_unlock();
 				put_files_struct(files);
@@ -101,7 +101,7 @@ static int tid_fd_revalidate(struct dent
 				}
 
 				if (S_ISLNK(inode->i_mode)) {
-					unsigned i_mode = S_IFLNK;
+					umode_t i_mode = S_IFLNK;
 					if (f_mode & FMODE_READ)
 						i_mode |= S_IRUSR | S_IXUSR;
 					if (f_mode & FMODE_WRITE)

Re: [vfs:master 30/32] fs/proc/fd.c:87:55: sparse: incorrect type in initializer (different base typ

[Al Viro]

On Sun, Aug 26, 2012 at 11:52:36PM +0400, Cyrill Gorcunov wrote:
> -				unsigned f_mode = file->f_mode;
> +				unsigned int f_mode = file->f_mode;

This changes nothing; unsigned and unsigned int are exactly the same.
fmode_t isn't, from sparse POV, and that's what you want to use here.

Re: [vfs:master 30/32] fs/proc/fd.c:87:55: sparse: incorrect type in initializer (different base typ

[Cyrill Gorcunov]

On Sun, Aug 26, 2012 at 09:20:49PM +0100, Al Viro wrote:
> On Sun, Aug 26, 2012 at 11:52:36PM +0400, Cyrill Gorcunov wrote:
> > -				unsigned f_mode = file->f_mode;
> > +				unsigned int f_mode = file->f_mode;
> 
> This changes nothing; unsigned and unsigned int are exactly the same.
> fmode_t isn't, from sparse POV, and that's what you want to use here.

True. I get messed with this warning. Please see updated below.
---
From: Cyrill Gorcunov <gorcunov@openvz.org>
Subject: fs, proc: Fix sparse warning in tid_fd_revalidate

The following warnings have been caught

 | + fs/proc/fd.c:87:55: sparse: incorrect type in initializer (different base types)
 |   fs/proc/fd.c:87:55:    expected unsigned int [unsigned] f_mode
 |   fs/proc/fd.c:87:55:    got restricted fmode_t [usertype] f_mode
 | + fs/proc/fd.c:105:54: sparse: restricted fmode_t degrades to integer
 |   fs/proc/fd.c:107:54: sparse: restricted fmode_t degrades to integer

make f_mode and i_mode declared with proper types.

Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
CC: Al Viro <viro@ZenIV.linux.org.uk>
---
 fs/proc/fd.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Index: linux-2.6.git/fs/proc/fd.c
=================================--- linux-2.6.git.orig/fs/proc/fd.c
+++ linux-2.6.git/fs/proc/fd.c
@@ -84,7 +84,7 @@ static int tid_fd_revalidate(struct dent
 			rcu_read_lock();
 			file = fcheck_files(files, fd);
 			if (file) {
-				unsigned f_mode = file->f_mode;
+				fmode_t f_mode = file->f_mode;
 
 				rcu_read_unlock();
 				put_files_struct(files);
@@ -101,7 +101,7 @@ static int tid_fd_revalidate(struct dent
 				}
 
 				if (S_ISLNK(inode->i_mode)) {
-					unsigned i_mode = S_IFLNK;
+					umode_t i_mode = S_IFLNK;
 					if (f_mode & FMODE_READ)
 						i_mode |= S_IRUSR | S_IXUSR;
 					if (f_mode & FMODE_WRITE)