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[66.111.4.228]) by smtp.gmail.com with ESMTPSA id g13sm425340ile.68.2021.09.07.19.17.47 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 07 Sep 2021 19:17:48 -0700 (PDT) Received: from compute4.internal (compute4.nyi.internal [10.202.2.44]) by mailauth.nyi.internal (Postfix) with ESMTP id 8EB9227C0054; Tue, 7 Sep 2021 22:17:47 -0400 (EDT) Received: from mailfrontend1 ([10.202.2.162]) by compute4.internal (MEProxy); Tue, 07 Sep 2021 22:17:47 -0400 X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedvtddrudefiedgheegucetufdoteggodetrfdotf fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfqfgfvpdfurfetoffkrfgpnffqhgen uceurghilhhouhhtmecufedttdenucesvcftvggtihhpihgvnhhtshculddquddttddmne cujfgurhepfffhvffukfhfgggtugfgjgesthekredttddtjeenucfhrhhomhepuehoqhhu nhcuhfgvnhhguceosghoqhhunhdrfhgvnhhgsehgmhgrihhlrdgtohhmqeenucggtffrrg htthgvrhhnpedvvdekhfeltedujeeuheevtdefueefheehfeeukedthedufeffleetueej vdejueenucevlhhushhtvghrufhiiigvpedtnecurfgrrhgrmhepmhgrihhlfhhrohhmpe gsohhquhhnodhmvghsmhhtphgruhhthhhpvghrshhonhgrlhhithihqdeiledvgeehtdei gedqudejjeekheehhedvqdgsohhquhhnrdhfvghngheppehgmhgrihhlrdgtohhmsehfih igmhgvrdhnrghmvg X-ME-Proxy: Received: by mail.messagingengine.com (Postfix) with ESMTPA; Tue, 7 Sep 2021 22:17:46 -0400 (EDT) Date: Wed, 8 Sep 2021 10:16:19 +0800 From: Boqun Feng To: Sebastian Andrzej Siewior Cc: Waiman Long , linux-kernel@vger.kernel.org, Peter Zijlstra , Ingo Molnar , Will Deacon , Thomas Gleixner Subject: Re: [PATCH v2] lockdep: Let lock_is_held_type() detect recursive read as read Message-ID: References: <20210901162255.u2vhecaxgjsjfdtc@linutronix.de> <9af2b074-9fcf-5aea-f37d-9b2482146489@redhat.com> <20210903084001.lblecrvz4esl4mrr@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20210903084001.lblecrvz4esl4mrr@linutronix.de> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Sep 03, 2021 at 10:40:01AM +0200, Sebastian Andrzej Siewior wrote: > lock_is_held_type(, 1) detects acquired read locks. It only recognized > locks acquired with lock_acquire_shared(). Read locks acquired with > lock_acquire_shared_recursive() are not recognized because a `2' is > stored as the read value. > > Rework the check to additionally recognise lock's read value one and two > as a read held lock. > > Fixes: e918188611f07 ("locking: More accurate annotations for read_lock()") > Signed-off-by: Sebastian Andrzej Siewior > --- > v1…v2: > - simplify the read check to !!read as suggested by Waiman Long. > > kernel/locking/lockdep.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > --- a/kernel/locking/lockdep.c > +++ b/kernel/locking/lockdep.c > @@ -5366,7 +5366,7 @@ int __lock_is_held(const struct lockdep_ > struct held_lock *hlock = curr->held_locks + i; > > if (match_held_lock(hlock, lock)) { > - if (read == -1 || hlock->read == read) > + if (read == -1 || hlock->read == !!read) I think this should be: !!hlock->read == read With that, Acked-by: Boqun Feng Regards, Boqun > return LOCK_STATE_HELD; > > return LOCK_STATE_NOT_HELD;