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[103.168.172.201]) by smtp.gmail.com with ESMTPSA id af79cd13be357-7cad2441633sm655256585a.107.2025.05.05.21.20.57 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 05 May 2025 21:20:57 -0700 (PDT) Received: from phl-compute-04.internal (phl-compute-04.phl.internal [10.202.2.44]) by mailfauth.phl.internal (Postfix) with ESMTP id 053211200068; Tue, 6 May 2025 00:20:57 -0400 (EDT) Received: from phl-mailfrontend-01 ([10.202.2.162]) by phl-compute-04.internal (MEProxy); Tue, 06 May 2025 00:20:57 -0400 X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgeefvddrtddtgddvkeeftddtucetufdoteggodetrf dotffvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdggtfgfnhhsuhgsshgtrhhisggv pdfurfetoffkrfgpnffqhgenuceurghilhhouhhtmecufedttdenucesvcftvggtihhpih gvnhhtshculddquddttddmnecujfgurhephffvvefufffkofgjfhgggfestdekredtredt tdenucfhrhhomhepuehoqhhunhcuhfgvnhhguceosghoqhhunhdrfhgvnhhgsehgmhgrih hlrdgtohhmqeenucggtffrrghtthgvrhhnpefghfffvefhhfdvgfejgfekvdelgfekgeev ueehlefhiedvgeffjefgteeugfehieenucffohhmrghinhepkhgvrhhnvghlrdhorhhgne cuvehluhhsthgvrhfuihiivgeptdenucfrrghrrghmpehmrghilhhfrhhomhepsghoqhhu nhdomhgvshhmthhprghuthhhphgvrhhsohhnrghlihhthidqieelvdeghedtieegqdduje ejkeehheehvddqsghoqhhunhdrfhgvnhhgpeepghhmrghilhdrtghomhesfhhigihmvgdr nhgrmhgvpdhnsggprhgtphhtthhopeduvddpmhhouggvpehsmhhtphhouhhtpdhrtghpth htohepmhhinhhgoheskhgvrhhnvghlrdhorhhgpdhrtghpthhtohepphgvthgvrhiisehi nhhfrhgruggvrggurdhorhhgpdhrtghpthhtohepmhhinhhgohesrhgvughhrghtrdgtoh hmpdhrtghpthhtohepfihilhhlsehkvghrnhgvlhdrohhrghdprhgtphhtthhopegsohhq uhhnrdhfvghnghesghhmrghilhdrtghomhdprhgtphhtthhopehlohhnghhmrghnsehrvg guhhgrthdrtghomhdprhgtphhtthhopehnrghthhgrnheskhgvrhhnvghlrdhorhhgpdhr tghpthhtohepnhhitghkrdguvghsrghulhhnihgvrhhsodhlkhhmlhesghhmrghilhdrtg homhdprhgtphhtthhopehmohhrsghosehgohhoghhlvgdrtghomh X-ME-Proxy: Feedback-ID: iad51458e:Fastmail Received: by mail.messagingengine.com (Postfix) with ESMTPA; Tue, 6 May 2025 00:20:56 -0400 (EDT) From: Boqun Feng To: Ingo Molnar , Peter Zijlstra Cc: Ingo Molnar , Will Deacon , Boqun Feng , Waiman Long , Nathan Chancellor , Nick Desaulniers , Bill Wendling , Justin Stitt , linux-kernel@vger.kernel.org, llvm@lists.linux.dev Subject: [PATCH 2/3] locking/lockdep: Prevent abuse of lockdep subclass Date: Mon, 5 May 2025 21:20:48 -0700 Message-Id: <20250506042049.50060-3-boqun.feng@gmail.com> X-Mailer: git-send-email 2.39.5 (Apple Git-154) In-Reply-To: <20250506042049.50060-1-boqun.feng@gmail.com> References: <20250506042049.50060-1-boqun.feng@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Waiman Long To catch the code trying to use a subclass value >=3D MAX_LOCKDEP_SUBCLASSES (8), add a DEBUG_LOCKS_WARN_ON() statement to notify the users that such a large value is not allowed. [boqun: Reword the commit log with a more objective tone] Signed-off-by: Waiman Long Signed-off-by: Boqun Feng Link: https://lore.kernel.org/r/20250409143751.2010391-1-longman@redhat.com --- kernel/locking/lockdep.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index ff2ce90a87bc..58883c8375d1 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -5101,6 +5101,9 @@ static int __lock_acquire(struct lockdep_map *lock, u= nsigned int subclass, lockevent_inc(lockdep_nocheck); } =20 + if (DEBUG_LOCKS_WARN_ON(subclass >=3D MAX_LOCKDEP_SUBCLASSES)) + return 0; + if (subclass < NR_LOCKDEP_CACHING_CLASSES) class =3D lock->class_cache[subclass]; /* --=20 2.39.5 (Apple Git-154)