On 28 July 2017 at 20:55, Dave Gerlach <[email protected]> wrote: > Hi, > On 07/28/2017 01:48 PM, Dave Gerlach wrote: >> Commit b6a1d093f96b ("PM / Domains: Extend generic power domain >> debugfs") extends the existing generic power domain debugfs to provide >> more information about each genpd, however it creates a debugfs >> directory for each based on the name of the genpd. While it is a good >> idea to populate the name field of each genpd, up until this commit it >> was not required. However, attempting to call debugfs_create_dir with a >> null name value causes a NULL pointer dereference panic. >> >> In order to keep things working as they did before the aforementioned >> patch, check to see if name has been populated and if not, skip creating >> the extended debugfs info path and warn that name is needed to get this >> extended info. >> >> Fixes: b6a1d093f96b ("PM / Domains: Extend generic power domain debugfs") >> Signed-off-by: Dave Gerlach <[email protected]> >> --- > > As changelog describes, commit b6a1d093f96b ("PM / Domains: Extend generic > power > domain debugfs") currently causes a NULL pointer dereference panic if no name > is > assigned for a struct generic_pm_domain registered with the framework. Before > this patch no name was required, so this patch is a first attempt to keep > things > that way and just warn the user that they can't get extended debugfs info > without providing a genpd name. > > Of course a name is always a good idea, so I'm not sure if this patch is how > we > want to go about preventing this panic or perhaps just making the name > mandatory > and checking during probe, but I figured I'd kick the discussion off with a > suggestion by sending this patch.
Instead of making it mandatory, why not assign ->name a generic name (genpd0, genpd1, genpd2, etc ) in case it isn't set. In that way, all debugfs prints using ->name, should at least show something... and the bug you report should also be fixed.. Kind regards Uffe
