[openbeosstorage] Re: [Open-beos-cvs]CVS:current/src/kernel/core/disk_device_managerddm_userland_interface.cpp,1.17,1.18

  • From: Tyler Dauwalder <tyler@xxxxxxxxxxxxx>
  • To: openbeosstorage@xxxxxxxxxxxxx
  • Date: Sun, 28 Sep 2003 03:25:25 -0700

On 2003-09-28 at 03:18:59 [-0700], Ingo Weinhold wrote:
> 
> On 2003-09-27 at 22:10:08 [+0200], Tyler Dauwalder wrote:
> > > [...]
> > > > @@ -538,11 +554,20 @@
> > > >  // _kern_get_disk_device_data
> > > >  status_t
> > > >  _kern_get_disk_device_data(partition_id id, bool deviceOnly, bool
> > > >  shadow,
> > > > -                           user_disk_device_data *buffer, size_t
> > > > bufferSize,
> > > > +                           user_disk_device_data *_buffer, size_t
> > > > bufferSize,
> > > >                             size_t *neededSize)
> > > >  {
> > > > -    if (!buffer && bufferSize > 0)
> > > > +    if (!_buffer && bufferSize > 0)
> > > >          return B_BAD_VALUE;
> > > > +
> > > > +    // copy in
> > > > +    user_disk_device_data *buffer = bufferSize > 0
> > > > +                                    ?
> > > > reinterpret_cast<user_disk_device_data*>(malloc(bufferSize))
> > > 
> > > static_cast should be sufficient, BTW. No need for the sledgehammer. ;-)
> > 
> > I'm not sure I see how reinterpret_cast<> is a sledgehammer.
> 
> Well, it cast anything to anything else. static_cast only casts between
> compatible pointer or reference types and even heeds consts.

Ah, I see; I took sledgehammer to imply it was heavy, a la dynamic_cast<>. At 
any rate, doesn't reinterpret_cast<> heed consts, as well? I thought only 
const_cast<> got to muck around with those.

> > > However, we should be more careful here. Since bufferSize may have a 
> > > huge
> > > value, we shouldn't malloc() kernel memory unchecked.
> > > So, either we set a reasonably great size constraint (100KB or so maybe)
> > > or
> > > do a dry run with the UserDataWriter to get the
> > > exactly required size. I'd prefer the latter solution.
> > 
> > Okay, I go for the latter.
> 
> Since I need the tests working, I'm going to fix that myself, now. I hope,
> you don't mind.

Sure, help yourself. :-)

-Tyler

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