Messages in this thread | | | Date | Mon, 9 Dec 2013 21:49:36 +0800 | Subject | Re: [PATCH v3] xen/debugfs: Check debugfs initialization before using it | From | Ethan Zhao <> |
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On Mon, Dec 9, 2013 at 7:19 PM, Greg KH <gregkh@linuxfoundation.org> wrote: > On Mon, Dec 09, 2013 at 05:56:52PM +0800, Ethan Zhao 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. >> >> V3: add warning message when debugfs not configured or disabled. > > That's not what this patch does... > >> 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; >> + } > > Again, why is this even needed? > > What problem in the existing code are you trying to solve? > What I want to ask who is so smart and fake some many functions when CONFIG_DEBUG_FS is not configured/defined and the build could pass without any error ? What is the motive make him wrote some many fake function and why he wrote the debugfs_initialized() function seem 'useless' at all ?
Thanks, Ethan
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