Re: [PATCH] vfs: remove redundant sanity check in do_mount

[Seunghun Lee <waydi1@gmail.com>]

On 09/13/2014 01:28 AM, Al Viro wrote:
> On Sat, Sep 13, 2014 at 12:53:32AM +0900, Seunghun Lee wrote:
>> In sys_mount, getname() checks dir_name.
>> So do_mount needn't check dir_name again.
> ... and simple grep shows four more call sites.  At the very least, the
> commit message needs to cover those as well, *if* the check is, indeed,
> redundant.  From the look through those guys it looks like it is, but...
> I wonder if it would make more sense to pass char __user * instead of
> char * here.  And do getname() inside do_mount().  As it is, we do
> getname() in all callers *and* never look into the result of said getname()
> until passing it to do_mount().  So how about just passing userland pointer
> all the way down to do_mount() (grep for callers and watch out for ones
> in arch/alpha/kernel/osf_sys.c) and doing getname() in do_mount() itself?
Ok, I will rework the patch.

Thanks.