From: Jonathan Wakely <jwakely.gcc@gmail.com>
To: Thomas Rodgers <rodgert@appliantology.com>
Cc: gcc-patches <gcc-patches@gcc.gnu.org>,
"libstdc++" <libstdc++@gcc.gnu.org>,
Thomas Rodgers <trodgers@redhat.com>,
Thomas Rodgers <rodgert@twrodgers.com>
Subject: Re: [PATCH] libstdc++: Fix UB in atomic_ref/wait_notify.cc [PR101761]
Date: Fri, 17 Sep 2021 00:39:48 +0100 [thread overview]
Message-ID: <CAH6eHdRMq9ceqeFvG56O2SKm8yvTyjeq2O40bPrV8S+GeWi_7g@mail.gmail.com> (raw)
In-Reply-To: <20210916221408.602576-1-rodgert@appliantology.com>
On Thu, 16 Sep 2021, 23:24 Thomas Rodgers, <rodgert@appliantology.com>
wrote:
> From: Thomas Rodgers <rodgert@twrodgers.com>
>
> Remove UB in atomic_ref/wait_notify test.
>
> Signed-off-by: Thomas Rodgers <trodgers@redhat.com>
>
> libstdc++-v3/ChangeLog:
>
> PR libstdc++/101761
> * testsuite/29_atomics/atomic_ref/wait_notify.cc (test): Use
> va and vb as arguments to wait/notify, remove unused bb local.
>
> Tested x86_64-pc-linux-gnu, committed to master.
> Ok to backport to releases/gcc-11?
>
Yes, ok for 11, thanks.
> ---
> .../testsuite/29_atomics/atomic_ref/wait_notify.cc | 7 +++----
> 1 file changed, 3 insertions(+), 4 deletions(-)
>
> diff --git a/libstdc++-v3/testsuite/29_atomics/atomic_ref/wait_notify.cc
> b/libstdc++-v3/testsuite/29_atomics/atomic_ref/wait_notify.cc
> index b75e27617f7..b41d1ac0bb7 100644
> --- a/libstdc++-v3/testsuite/29_atomics/atomic_ref/wait_notify.cc
> +++ b/libstdc++-v3/testsuite/29_atomics/atomic_ref/wait_notify.cc
> @@ -33,15 +33,14 @@ template<typename S>
> if constexpr (std::atomic_ref<S>::is_always_lock_free)
> {
> S aa{ va };
> - S bb{ vb };
> std::atomic_ref<S> a{ aa };
> - a.wait(bb);
> + a.wait(vb);
> std::thread t([&]
> {
> - a.store(bb);
> + a.store(vb);
> a.notify_one();
> });
> - a.wait(aa);
> + a.wait(va);
> t.join();
> }
> }
> --
> 2.31.1
>
>
prev parent reply other threads:[~2021-09-16 23:40 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-16 22:14 Thomas Rodgers
2021-09-16 23:39 ` Jonathan Wakely [this message]
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