On Sat, 11 Jul 2015 10:25:13 +0900 Sergey Senozhatsky 
<[email protected]> wrote:

> > > I was thinking of a trivial INIT_SHRINKER macro to init `struct shrinker'
> > > internal members (composed in email client, not tested)
> > > 
> > > include/linux/shrinker.h
> > > 
> > > #define INIT_SHRINKER(s)                  \
> > >   do {                                    \
> > >           (s)->nr_deferred = NULL;        \
> > >           INIT_LIST_HEAD(&(s)->list);     \
> > >   } while (0)
> > 
> > Spose so.  Although it would be simpler to change unregister_shrinker()
> > to bale out if list.next==NULL and then say "all zeroes is the
> > initialized state".
> 
> Yes, or '->nr_deferred == NULL' -- we can't have NULL ->nr_deferred
> in a properly registered shrinker (as of now)

list.next seems safer because that will always be non-zero.  But
whatever - we can change it later.
 
> But that will not work if someone has accidentally passed not zeroed
> out pointer to unregister.

I wouldn't worry about that really.  If you pass a pointer to
uninitialized memory, the kernel will explode.  That's true of just
about every pointer-accepting function in the kernel.


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to