[PATCH v2] xen/debugfs: Check debugfs initialization before using it

[PATCH v2] xen/debugfs: Check debugfs initialization before using it

[Ethan Zhao]

From: "Ethan Zhao" <ethan.kernel@gmail.com>

Should check debugfs initialization with debugfs_initialized() before using it,
Because if it isn't initialized, the return value of fake debugfs_create_dir() etc
functions would be ERR_PTR(-ENODEV), checking with NULL will not work.

V2: change to normative author name.

Signed-off-by: Ethan Zhao <ethan.kernel@gmail.com>
---
 arch/x86/xen/debugfs.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/arch/x86/xen/debugfs.c b/arch/x86/xen/debugfs.c
index c8377fb..85c0e0e 100644
--- a/arch/x86/xen/debugfs.c
+++ b/arch/x86/xen/debugfs.c
@@ -9,12 +9,18 @@ static struct dentry *d_xen_debug;
 
 struct dentry * __init xen_init_debugfs(void)
 {
+	if (!debugfs_initialized()) {
+		d_xen_debug = NULL;
+		goto nodebugfs;
+	}
+
 	if (!d_xen_debug) {
 		d_xen_debug = debugfs_create_dir("xen", NULL);
 
 		if (!d_xen_debug)
 			pr_warning("Could not create 'xen' debugfs directory\n");
 	}
+nodebugfs:
 
 	return d_xen_debug;
 }
-- 
1.8.3.4 (Apple Git-47)

Re: [PATCH v2] xen/debugfs: Check debugfs initialization before using it

[Ethan Zhao]

All,
  Please ignore this one, sorry, see v3.


Thanks,
Ethan

On Mon, Dec 9, 2013 at 5:42 PM, Ethan Zhao <ethan.kernel@gmail.com> wrote:
> From: "Ethan Zhao" <ethan.kernel@gmail.com>
>
> Should check debugfs initialization with debugfs_initialized() before using it,
> Because if it isn't initialized, the return value of fake debugfs_create_dir() etc
> functions would be ERR_PTR(-ENODEV), checking with NULL will not work.
>
> V2: change to normative author name.
>
> Signed-off-by: Ethan Zhao <ethan.kernel@gmail.com>
> ---
>  arch/x86/xen/debugfs.c | 6 ++++++
>  1 file changed, 6 insertions(+)
>
> diff --git a/arch/x86/xen/debugfs.c b/arch/x86/xen/debugfs.c
> index c8377fb..85c0e0e 100644
> --- a/arch/x86/xen/debugfs.c
> +++ b/arch/x86/xen/debugfs.c
> @@ -9,12 +9,18 @@ static struct dentry *d_xen_debug;
>
>  struct dentry * __init xen_init_debugfs(void)
>  {
> +       if (!debugfs_initialized()) {
> +               d_xen_debug = NULL;
> +               goto nodebugfs;
> +       }
> +
>         if (!d_xen_debug) {
>                 d_xen_debug = debugfs_create_dir("xen", NULL);
>
>                 if (!d_xen_debug)
>                         pr_warning("Could not create 'xen' debugfs directory\n");
>         }
> +nodebugfs:
>
>         return d_xen_debug;
>  }
> --
> 1.8.3.4 (Apple Git-47)
>