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[103.168.172.200]) by smtp.gmail.com with ESMTPSA id 6a1803df08f44-6f50f3c32b5sm44759346d6.30.2025.05.04.11.03.32 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 04 May 2025 11:03:32 -0700 (PDT) Received: from phl-compute-01.internal (phl-compute-01.phl.internal [10.202.2.41]) by mailfauth.phl.internal (Postfix) with ESMTP id 1D6501200043; Sun, 4 May 2025 14:03:32 -0400 (EDT) Received: from phl-mailfrontend-01 ([10.202.2.162]) by phl-compute-01.internal (MEProxy); Sun, 04 May 2025 14:03:32 -0400 X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgeefvddrtddtgddvjeekkeekucetufdoteggodetrf dotffvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdggtfgfnhhsuhgsshgtrhhisggv pdfurfetoffkrfgpnffqhgenuceurghilhhouhhtmecufedttdenucesvcftvggtihhpih gvnhhtshculddquddttddmnecujfgurhepfffhvfevuffkfhggtggujgesthdtredttddt vdenucfhrhhomhepuehoqhhunhcuhfgvnhhguceosghoqhhunhdrfhgvnhhgsehgmhgrih hlrdgtohhmqeenucggtffrrghtthgvrhhnpeehudfgudffffetuedtvdehueevledvhfel leeivedtgeeuhfegueevieduffeivdenucevlhhushhtvghrufhiiigvpedtnecurfgrrh grmhepmhgrihhlfhhrohhmpegsohhquhhnodhmvghsmhhtphgruhhthhhpvghrshhonhgr lhhithihqdeiledvgeehtdeigedqudejjeekheehhedvqdgsohhquhhnrdhfvghngheppe hgmhgrihhlrdgtohhmsehfihigmhgvrdhnrghmvgdpnhgspghrtghpthhtohepiedpmhho uggvpehsmhhtphhouhhtpdhrtghpthhtoheplhhonhhgmhgrnhesrhgvughhrghtrdgtoh hmpdhrtghpthhtohepphgvthgvrhiisehinhhfrhgruggvrggurdhorhhgpdhrtghpthht ohepmhhinhhgohesrhgvughhrghtrdgtohhmpdhrtghpthhtohepfihilhhlrdguvggrtg honhesrghrmhdrtghomhdprhgtphhtthhopehlihhnuhigqdhkvghrnhgvlhesvhhgvghr rdhkvghrnhgvlhdrohhrghdprhgtphhtthhopegsohhquhhnsehfihigmhgvrdhnrghmvg X-ME-Proxy: Feedback-ID: iad51458e:Fastmail Received: by mail.messagingengine.com (Postfix) with ESMTPA; Sun, 4 May 2025 14:03:31 -0400 (EDT) Date: Sun, 4 May 2025 11:03:30 -0700 From: Boqun Feng To: Waiman Long Cc: Peter Zijlstra , Ingo Molnar , Will Deacon , linux-kernel@vger.kernel.org Subject: Re: [PATCH] locking/lockdep: Prevent abuse of lockdep subclass Message-ID: References: <20250409143751.2010391-1-longman@redhat.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250409143751.2010391-1-longman@redhat.com> On Wed, Apr 09, 2025 at 10:37:51AM -0400, Waiman Long wrote: > As I have seen code trying to use a subclass value >= > MAX_LOCKDEP_SUBCLASSES (8), add a DEBUG_LOCKS_WARN_ON() statement to > notify the users that such a large value is not allowed. > > Signed-off-by: Waiman Long Queued for 6.16, thanks! Regards, Boqun > --- > kernel/locking/lockdep.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c > index 58d78a33ac65..3fb79d8fecdf 100644 > --- a/kernel/locking/lockdep.c > +++ b/kernel/locking/lockdep.c > @@ -5101,6 +5101,9 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass, > lockevent_inc(lockdep_nocheck); > } > > + if (DEBUG_LOCKS_WARN_ON(subclass >= MAX_LOCKDEP_SUBCLASSES)) > + return 0; > + > if (subclass < NR_LOCKDEP_CACHING_CLASSES) > class = lock->class_cache[subclass]; > /* > -- > 2.48.1 >