linux-next: build warning after merge of the overlayfs tree

linux-next: build warning after merge of the overlayfs tree

[Stephen Rothwell]

Hi Miklos,

After merging the overlayfs tree, today's linux-next build (powerpc
ppc64_defconfig) produced this warning:

fs/overlayfs/super.c: In function 'ovl_fill_super':
fs/overlayfs/super.c:1070:25: warning: 'numlower' may be used uninitialized in this function [-Wmaybe-uninitialized]
  unsigned int stacklen, numlower, i;
                         ^
fs/overlayfs/super.c:1069:15: warning: 'stack' may be used uninitialized in this function [-Wmaybe-uninitialized]
  struct path *stack;
               ^

-- 
Cheers,
Stephen Rothwell

Re: linux-next: build warning after merge of the overlayfs tree

[Chandan Rajendra]

On Thursday, November 9, 2017 4:03:06 AM IST Stephen Rothwell wrote:
> Hi Miklos,
> 
> After merging the overlayfs tree, today's linux-next build (powerpc
> ppc64_defconfig) produced this warning:
> 
> fs/overlayfs/super.c: In function 'ovl_fill_super':
> fs/overlayfs/super.c:1070:25: warning: 'numlower' may be used uninitialized in this function [-Wmaybe-uninitialized]
>   unsigned int stacklen, numlower, i;
>                          ^
> fs/overlayfs/super.c:1069:15: warning: 'stack' may be used uninitialized in this function [-Wmaybe-uninitialized]
>   struct path *stack;
>                ^
> 
> 

The following trivial patch resolves the warnings,

diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index fd11c05..602e686 100644
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -1066,8 +1066,8 @@ static struct ovl_entry *ovl_get_lowerstack(struct super_block *sb,
 {
        int err;
        char *lowertmp, *lower;
-       struct path *stack;
-       unsigned int stacklen, numlower, i;
+       struct path *stack = NULL;
+       unsigned int stacklen, numlower = 0, i;
        bool remote = false;
        struct ovl_entry *oe;
 
-- 
chandan

Re: linux-next: build warning after merge of the overlayfs tree

[Miklos Szeredi]

On Tue, 20 Jul 2021 at 08:38, Stephen Rothwell <sfr@canb.auug.org.au> wrote:
>
> Hi all,
>
> After merging the overlayfs tree, today's linux-next build (htmldocs)
> produced this warning:
>
> Documentation/filesystems/api-summary:95: fs/stat.c:67: WARNING: Unknown target name: "statx_attr".
>
> Introduced by commit
>
>   d1e717e0032c ("fs: add generic helper for filling statx attribute flags")

Thanks, fix folded and force pushed.

Miklos

linux-next: build warning after merge of the overlayfs tree

[Stephen Rothwell]

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Hi all,

After merging the overlayfs tree, today's linux-next build (htmldocs)
produced this warning:

Documentation/filesystems/api-summary:95: fs/stat.c:67: WARNING: Unknown target name: "statx_attr".

Introduced by commit

  d1e717e0032c ("fs: add generic helper for filling statx attribute flags")

-- 
Cheers,
Stephen Rothwell

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Re: linux-next: build warning after merge of the overlayfs tree

[Stephen Rothwell]

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Hi all,

On Mon, 29 Mar 2021 20:14:26 +1100 Stephen Rothwell <sfr@canb.auug.org.au> wrote:
>
> After merging the overlayfs tree, today's linux-next build (htmldocs)
> produced this warning:
> 
> Documentation/devicetree/kernel-api:56: /home/sfr/next/next/drivers/of/overlay.c:1184: WARNING: Inline emphasis start-string without end-string.
> 
> Introduced by commit
> 
>   24789c5ce5a3 ("of: overlay: detect cases where device tree may become corrupt")
> 
> Probably exposed by commit
> 
>   8c8239c2c1fb ("of: Add missing 'Return' section in kerneldoc comments")

I am still seeing this warning (as of next-20210420).
-- 
Cheers,
Stephen Rothwell

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Re: linux-next: build warning after merge of the overlayfs tree

[Stephen Rothwell]

Hi Miklos,

On Mon, 29 Mar 2021 11:28:10 +0200 Miklos Szeredi <miklos@szeredi.hu> wrote:
>
> On Mon, Mar 29, 2021 at 11:14 AM Stephen Rothwell <sfr@canb.auug.org.au> wrote:
> >
> > Hi all,
> >
> > After merging the overlayfs tree, today's linux-next build (htmldocs)  
> 
> I think you mixed up drivers/of/overlay.c with fs/overlay/.

You are entirely correct and I have no idea how I managed that :-(

-- 
Cheers,
Stephen Rothwell

Re: linux-next: build warning after merge of the overlayfs tree

[Miklos Szeredi]

On Mon, Mar 29, 2021 at 11:14 AM Stephen Rothwell <sfr@canb.auug.org.au> wrote:
>
> Hi all,
>
> After merging the overlayfs tree, today's linux-next build (htmldocs)

Hi Stephen,

I think you mixed up drivers/of/overlay.c with fs/overlay/.

Thanks,
Miklos

linux-next: build warning after merge of the overlayfs tree

[Stephen Rothwell]

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Hi all,

After merging the overlayfs tree, today's linux-next build (htmldocs)
produced this warning:

Documentation/devicetree/kernel-api:56: /home/sfr/next/next/drivers/of/overlay.c:1184: WARNING: Inline emphasis start-string without end-string.

Introduced by commit

  24789c5ce5a3 ("of: overlay: detect cases where device tree may become corrupt")

Probably exposed by commit

  8c8239c2c1fb ("of: Add missing 'Return' section in kerneldoc comments")

-- 
Cheers,
Stephen Rothwell

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Re: linux-next: build warning after merge of the overlayfs tree

[Amir Goldstein]

On Wed, May 17, 2017 at 3:19 AM, Stephen Rothwell <sfr@canb.auug.org.au> wrote:
> Hi Miklos,
>
> After merging the overlayfs tree, today's linux-next build (powerpc
> ppc64_defconfig) produced this warning:
>
> fs/overlayfs/dir.c: In function 'ovl_rename':
> fs/overlayfs/dir.c:1060:2: warning: 'newdentry' may be used uninitialized in this function [-Wmaybe-uninitialized]
>   dput(newdentry);
>   ^
> fs/overlayfs/dir.c:1062:2: warning: 'olddentry' may be used uninitialized in this function [-Wmaybe-uninitialized]
>   dput(olddentry);
>   ^
>
> Introduced by commit
>
>   02cac3227a28 ("ovl: mark upper dir with type origin entries "impure"")
>

Posted a fix for that ("ovl: fix wrong error handling of ovl_set_impure()")

Thanks!

linux-next: build warning after merge of the overlayfs tree

[Stephen Rothwell]

Hi Miklos,

After merging the overlayfs tree, today's linux-next build (powerpc
ppc64_defconfig) produced this warning:

fs/overlayfs/dir.c: In function 'ovl_rename':
fs/overlayfs/dir.c:1060:2: warning: 'newdentry' may be used uninitialized in this function [-Wmaybe-uninitialized]
  dput(newdentry);
  ^
fs/overlayfs/dir.c:1062:2: warning: 'olddentry' may be used uninitialized in this function [-Wmaybe-uninitialized]
  dput(olddentry);
  ^

Introduced by commit

  02cac3227a28 ("ovl: mark upper dir with type origin entries "impure"")

-- 
Cheers,
Stephen Rothwell

Re: linux-next: build warning after merge of the overlayfs tree

[Miklos Szeredi]

On Tue, Nov 22, 2016 at 1:19 AM, Stephen Rothwell <sfr@canb.auug.org.au> wrote:
> Hi Miklos,
>
> After merging the overlayfs tree, today's linux-next build (powerpc
> ppc64_defconfig) produced this warning:
>
> In file included from fs/overlayfs/dir.c:20:0:
> fs/overlayfs/dir.c: In function 'ovl_set_redirect':
> fs/overlayfs/overlayfs.h:92:6: warning: 'ret' may be used uninitialized in this function [-Wmaybe-uninitialized]
>   int err = vfs_setxattr(dentry, name, value, size, flags);
>       ^
> fs/overlayfs/dir.c:788:14: note: 'ret' was declared here
>   char *buf, *ret;
>               ^
>
> Introduced by commit
>
>   496654b0792e ("ovl: redirect on rename-dir")
>
> This is not necessarily a false positive (although is is a confusing
> message): if the kmalloc of "buf" fails and samedir was not set in
> ovl_get_redirect(), then "return ret" will be executed but "ret" has
> not been set.

Fixed. Thanks for reporting.

Miklos

linux-next: build warning after merge of the overlayfs tree

[Stephen Rothwell]

Hi Miklos,

After merging the overlayfs tree, today's linux-next build (powerpc
ppc64_defconfig) produced this warning:

In file included from fs/overlayfs/dir.c:20:0:
fs/overlayfs/dir.c: In function 'ovl_set_redirect':
fs/overlayfs/overlayfs.h:92:6: warning: 'ret' may be used uninitialized in this function [-Wmaybe-uninitialized]
  int err = vfs_setxattr(dentry, name, value, size, flags);
      ^
fs/overlayfs/dir.c:788:14: note: 'ret' was declared here
  char *buf, *ret;
              ^

Introduced by commit

  496654b0792e ("ovl: redirect on rename-dir")

This is not necessarily a false positive (although is is a confusing
message): if the kmalloc of "buf" fails and samedir was not set in
ovl_get_redirect(), then "return ret" will be executed but "ret" has
not been set.

-- 
Cheers,
Stephen Rothwell