Re: [PATCH] android: binder: print error message on failure of creating proc file

[Greg Kroah-Hartman]

On Fri, Jul 12, 2024 at 03:52:32PM +0900, Leesoo Ahn wrote:
> 2024년 7월 12일 (금) 오후 1:01, Carlos Llamas <cmllamas@xxxxxxxxxx>님이 작성:
> >
> > On Fri, Jul 12, 2024 at 12:21:40PM +0900, Leesoo Ahn wrote:
> > > It better prints out an error message to give more information if
> > > calling debugfs_create_file() is failure and the return value has an
> > > error code.
> > >
> > > Signed-off-by: Leesoo Ahn <lsahn@xxxxxxxxxx>
> > > ---
> >
> > What are you trying to fix? My understanding is that users of the
> > debugfs API can safely ignore any errors and move on. IMO it doesn't
> > make sense to add this without a real reason.
> 
> What I was trying to say, users would predict that a file under
> debugfs will be created while they are opening a binder device. But if
> it failed for some reason without any debug message, they would get
> confused that the file doesn't exist and have no clue what happened
> without a message.

And that's fine, again, the kernel does not care if debugfs is working
or not.  It's just a debugging help, it does not affect the normal
operation of a system at all, and as such, userspace can't rely on it
being present for any functionality other than debugging issues that
might happen at times.

thanks,

greg k-h