Messages in this thread | | | Date | Mon, 22 Jul 2019 10:40:48 -0400 | From | Steven Rostedt <> | Subject | Re: [PATCH v3 12/24] erofs: introduce tagged pointer |
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On Mon, 22 Jul 2019 09:16:22 +0300 Amir Goldstein <amir73il@gmail.com> wrote:
> CC kernel/trace maintainers for RB_PAGE_HEAD/RB_PAGE_UPDATE > and kernel/locking maintainers for RT_MUTEX_HAS_WAITERS
Interesting.
> > > (Is there some use scenerios in overlayfs and fanotify?...) > > We had one in overlayfs once. It is gone now. > > > > > and I'm not sure Al could accept __fdget conversion (I just wanted to give a example then...) > > > > Therefore, I tend to keep silence and just promote EROFS... some better ideas?... > > > > Writing example conversion patches to demonstrate cleaner code > and perhaps reduce LOC seems the best way.
Yes, I would be more interested in seeing patches that clean up the code than just talking about it.
> > Also pointing out that fixing potential bugs in one implementation is preferred > to having to patch all copied implementations. > > I wonder if tagptr_unfold_tags() doesn't need READ_ONCE() as per: > 1be5d4fa0af3 locking/rtmutex: Use READ_ONCE() in rt_mutex_owner() > > rb_list_head() doesn't have READ_ONCE()
Hmm, even if the compiler decided to reread the data, it would still need to clear the extra bits wouldn't it? Or am I missing something?
-- Steve
> Nor does hlist_bl_first() and BPF_MAP_PTR(). > > Are those all safe due to safe call sites? or potentially broken?
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