Re: [PATCH v6 21/57] dyndbg: test DECLARE_DYNDBG_CLASSMAP, sysfs nodes

[Greg KH]

On Wed, Sep 07, 2022 at 04:54:00PM +0200, Greg KH wrote:
> On Sun, Sep 04, 2022 at 03:40:58PM -0600, Jim Cromie wrote:
> > Demonstrate use of DECLARE_DYNDBG_CLASSMAP macro, and expose them as
> > sysfs-nodes for testing.
> 
> Wait, why sysfs?
> 
> sysfs isn't for testing, why not use debugfs?
> 
> 
> > 
> > For each of the 4 class-map-types:
> > 
> >   - declare a class-map of that type,
> >   - declare the enum corresponding to those class-names
> >   - share _base across 0..30 range
> >   - add a __pr_debug_cls() call for each class-name
> >   - declare 2 sysnodes for each class-map
> >     for 'p' flag, and future 'T' flag
> > 
> > These declarations create the following sysfs parameter interface:
> > 
> >   :#> pwd
> >   /sys/module/test_dynamic_debug/parameters
> >   :#> ls
> >   T_disjoint_bits  T_disjoint_names  T_level_names  T_level_num  do_prints
> >   p_disjoint_bits  p_disjoint_names  p_level_names  p_level_num
> 
> What is in these files?
> 
> For sysfs stuff, you need Documentation/ABI entries so that you can't
> abuse sysfs.  With debugfs, you can do anything you want :)

Ah, it's just module parameter abuse, not a "normal" sysfs file at all :)

Nevermind, sorry for the noise...

greg k-h