• Eric W. Biederman's avatar
    sysfs: Complain bitterly about attempts to remove files from nonexistent directories. · ce597919
    Eric W. Biederman authored
    
    
    Recently an OOPS was observed from the usb serial io_ti driver when it tried to remove
    sysfs directories.  Upon investigation it turns out this driver was always buggy
    and that a recent sysfs change had stopped guarding itself against removing attributes
    from sysfs directories that had already been removed. :(
    
    Historically we have been silent about attempting to files from nonexistent sysfs
    directories and have politely returned error codes.  That has resulted in people writing
    broken code that ignores the error codes.
    
    Issue a kernel WARNING and a stack backtrace to make it clear in no uncertain
    terms that abusing sysfs is not ok, and the callers need to fix their code.
    
    This change transforms the io_ti OOPS into a more comprehensible error message
    and stack backtrace.
    Signed-off-by: default avatarEric W. Biederman <ebiederm@xmission.com>
    Reported-by: default avatarWolfgang Frisch <wfpub@roembden.net>
    Cc: stable <stable@vger.kernel.org>
    Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
    ce597919