Re: [PATCH v5] printk: Userspace format enumeration support

[Petr Mladek <pmladek@suse.com>]

On Wed 2021-03-10 13:16:43, Greg Kroah-Hartman wrote:
> On Wed, Mar 10, 2021 at 12:12:57PM +0000, Chris Down wrote:
> > Greg Kroah-Hartman writes:
> > > On Wed, Mar 10, 2021 at 02:30:31AM +0000, Chris Down wrote:
> > > > +	ps->file = debugfs_create_file(pi_get_module_name(mod), 0444, dfs_index,
> > > > +				       ps, &dfs_index_fops);
> > > > +
> > > > +	if (IS_ERR(ps->file)) {
> > > > +		pi_sec_remove(mod);
> > > > +		return;
> > > > +	}
> > > 
> > > No need to check this and try to clean up if there is a problem, just
> > > save the pointer off and call debugfs_remove() when you want to clean
> > > up.
> > 
> > Petr, what are your thoughts on this, since you requested the cleanup on
> > debugfs failure? :-)
> 
> There is nothing to "clean up" if there is a debugfs failure here so I
> don't see the need.

My main concern is that the allocated struct pi_sec must not be leaked
when debugfs file was not created.

I still have to check if it would be freed even without the file
when the module is going out.


> > > Or better yet, no need to save anything, you can always look it up when
> > > you want to remove it, that will save you one pointer per module.
> > 
> > That's a good point, and with that maybe we can even do away with the pi_sec
> > entirely then since that only leaves start/end pointers which we can
> > calculate on demand from existing data.
> 
> Please do, that makes the code simpler overall.

Yup, that might make things even easier. Well, I still have to go and
try to better understand the new patch.

Best Regards,
Petr