From: Nadav Amit <nadav.amit@gmail.com>
To: Linus Torvalds <torvalds@linuxfoundation.org>
Cc: Will Deacon <will@kernel.org>, Jann Horn <jannh@google.com>,
"Paul E. McKenney" <paulmck@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
Peter Zijlstra <peterz@infradead.org>,
Suren Baghdasaryan <surenb@google.com>,
Matthew Wilcox <willy@infradead.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
linux-mm <linux-mm@kvack.org>,
Alan Stern <stern@rowland.harvard.edu>,
Andrea Parri <parri.andrea@gmail.com>,
Boqun Feng <boqun.feng@gmail.com>,
Nicholas Piggin <npiggin@gmail.com>,
David Howells <dhowells@redhat.com>,
Jade Alglave <j.alglave@ucl.ac.uk>,
Luc Maranget <luc.maranget@inria.fr>,
Akira Yokosawa <akiyks@gmail.com>,
Daniel Lustig <dlustig@nvidia.com>,
Joel Fernandes <joel@joelfernandes.org>
Subject: Re: [PATCH 0/2] fix vma->anon_vma check for per-VMA locking; fix anon_vma memory ordering
Date: Thu, 27 Jul 2023 13:11:43 -0700 [thread overview]
Message-ID: <2229115A-23F2-4B6B-800C-7182199DF79D@gmail.com> (raw)
In-Reply-To: <CAHk-=wgeMOvL=ko_eruf5St7h0e9dVn4+GMKjcdshTJoxyD8tw@mail.gmail.com>
> On Jul 27, 2023, at 12:39 PM, Linus Torvalds <torvalds@linuxfoundation.org> wrote:
>
> On Thu, 27 Jul 2023 at 12:10, Nadav Amit <nadav.amit@gmail.com> wrote:
>>
>> Interesting. I wonder if you considered adding to READ_ONCE() something
>> like:
>>
>> asm volatile("" : "+g" (x) );
>>
>> So later loads (such as baz = *ptr) would reload the updated value.
>
> Not necessarily a bad idea. Although I suspect you'd want to add
> *two* of them - on either side - to make sure any previous loads
> wouldn't be moved around it either.
You are right, two are needed.
I’ll give it a shot and see if I see changes to the binary.
next prev parent reply other threads:[~2023-07-27 20:12 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-07-26 21:41 Jann Horn
2023-07-26 21:41 ` [PATCH 1/2] mm: lock_vma_under_rcu() must check vma->anon_vma under vma lock Jann Horn
2023-07-27 21:52 ` Suren Baghdasaryan
2023-07-26 21:41 ` [PATCH 2/2] mm: Fix anon_vma memory ordering Jann Horn
2023-07-26 21:50 ` Jann Horn
2023-07-27 18:25 ` Linus Torvalds
2023-07-26 23:19 ` [PATCH 0/2] fix vma->anon_vma check for per-VMA locking; fix " Paul E. McKenney
2023-07-27 14:39 ` Jann Horn
2023-07-27 14:57 ` Will Deacon
2023-07-27 15:44 ` Alan Stern
2023-07-27 16:10 ` Jann Horn
2023-07-27 16:17 ` Paul E. McKenney
2023-07-27 16:16 ` Paul E. McKenney
2023-07-27 17:11 ` Linus Torvalds
2023-07-27 17:41 ` Alan Stern
2023-07-27 18:01 ` Linus Torvalds
2023-07-27 19:05 ` Nadav Amit
2023-07-27 19:39 ` Linus Torvalds
2023-07-27 20:11 ` Nadav Amit [this message]
2023-07-28 9:18 ` Nadav Amit
2023-07-27 15:07 ` Matthew Wilcox
2023-07-27 15:15 ` Jann Horn
2023-07-27 16:09 ` Paul E. McKenney
2023-07-27 16:34 Joel Fernandes
2023-07-28 12:44 ` Will Deacon
2023-07-28 17:35 ` Joel Fernandes
2023-07-28 17:51 ` Alan Stern
2023-07-28 18:03 ` Joel Fernandes
2023-07-28 18:18 ` Paul E. McKenney
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