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

[Greg KH]

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 :)

thanks,

greg k-h