From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wr1-f51.google.com (mail-wr1-f51.google.com [209.85.221.51]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 80EAC61FFC; Sat, 24 Aug 2024 19:12:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.221.51 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724526775; cv=none; b=N2t4j0n8H7mxtSIv/PazsbqhRcFLwIw6SK93u6bieXCe1bQpxW2Hdudht7QZQwqVP6Zl/fZ9kwRvB1SkSU788oLoV5yaDrHDQINXc7fQCuStY1yKU7UrGsU96w4oLxIVgTAlwR+MBfdSncymU7Y6EvXhTLj1FtCPHCfZM33We3g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724526775; c=relaxed/simple; bh=dRsDBERBKXGQmlNxsmOYsnycmpuJFUc5IIm+FZN1U5I=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=eeTmHHawug+j57fGQhfjdRdls5HRxQh2LotXFD2KfnKNY4Cai6AA377wVevE2WyjSMZD37bfg9+mgfBQOQv6L3HN6PMc7IjCQwdtTecMZiROCyeuguCrEN7eKC6UE8iFTU3R1l1STlA6N8gFU2mRhLdXsAHaKlL6zJ6Vjyv4Bgw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=U2ZeEYbP; arc=none smtp.client-ip=209.85.221.51 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="U2ZeEYbP" Received: by mail-wr1-f51.google.com with SMTP id ffacd0b85a97d-3718cd91185so1552600f8f.2; Sat, 24 Aug 2024 12:12:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1724526771; x=1725131571; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=vxw92cxeIEiHhs9EMgxgq3pO39LFJ0Vnsb2d9XSPFpU=; b=U2ZeEYbP5QsmUn61qTqEkBRfGcvO9rITHaVaoP+oQ3JBWfzc6XCDEnxz4FPgX9QGiQ uWbxRUbsX3CdNaOSBKxVaGSo3T+Oc3Z/SLeZJx5sC6MAzaFQO4fbPuEmJFQhrniuGtm+ aW/WiBg4ws/gX8RJhTxx4q8GOALjX+XHOrO+ILCj7C9wcUBM4T3a6giJbDHvhn7Zo7Me P5rr13LhVN2Kwx5KjuV/jzvDV+1AxsMRvbbG84kuAd7owdh87fSP6N+fGHKMVmf3btuZ /vffp0NlIf5RTtnW81gHrA2rVzVvZNFuv5ZzgozTaWfQaFEkWv6b3kYcBJlmzuhc8xaO wHVA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1724526771; x=1725131571; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=vxw92cxeIEiHhs9EMgxgq3pO39LFJ0Vnsb2d9XSPFpU=; b=w0A20t6dj7qx4c+wWm1/5ucA5iD6hI2csuLoLGemseYJgNm4d0n6RRqhdUO0jCgjVG EUnK8XjhzCAz5TxJHW50m8qsK1g/d8F8TzYuX6s47Keg62NQWw1p3FOvgLsSTb7D+DV3 a/FKAPpcR+oMNlMqtjUMte74x5ZZTivY3fSx98ORdUECZeWHNFS16q4S5Bk/4s1BEnyX O+xSODTGucnJnfi3itI0bHUt6RlFUeUAR/xaAoVfcoU94ci/w9OROHr7yqpVPEUJVsiU 4uUN0nlG4oLfYYpH9eXO4LSv6VFI98Sz3rJ3hsv0hz0F+LBrUk3BbRyxV8qbMSNf8qrT 1uHg== X-Forwarded-Encrypted: i=1; AJvYcCXF2J4j9cR2FufAKBrGjE1doPrLF7ymG1/zAzkCi7o9nAOuRgOy4OKQPM1LFVjV/FQXJ5HbAIWB7KKW@vger.kernel.org X-Gm-Message-State: AOJu0YxeQeE75X8plW4rydQilWGCl59omfLmLt0ruKdMzedaogdi/SkA vEmfE/sjbsjnwNV8l1ySmLACTpg3E+08nKZqilFN7rK6ndsUypjpqsBKN41fSHQ= X-Google-Smtp-Source: AGHT+IF9Li3MJwjnTCQZvRS3VVn7nuqBi4T5p7Mo+MHjDsuw5dg8olBZhngWv1qKDBfikGef2aL15A== X-Received: by 2002:a5d:5273:0:b0:371:a70d:107e with SMTP id ffacd0b85a97d-37311843365mr3676162f8f.6.1724526770689; Sat, 24 Aug 2024 12:12:50 -0700 (PDT) Received: from localhost.localdomain ([156.197.22.60]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-3730813c520sm7109793f8f.39.2024.08.24.12.12.49 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 24 Aug 2024 12:12:50 -0700 (PDT) From: Ahmed Ehab To: linux-kernel@vger.kernel.org Cc: Peter Zijlstra , Ingo Molnar , Will Deacon , Waiman Long , Boqun Feng , linux-ext4@vger.kernel.org, syzkaller@googlegroups.com Subject: [PATCH v6 2/2] locking/lockdep: Test no new string literal is created in lockdep_set_subclass() Date: Sun, 25 Aug 2024 01:10:31 +0300 Message-ID: <20240824221031.7751-2-bottaawesome633@gmail.com> X-Mailer: git-send-email 2.46.0 In-Reply-To: <20240824221031.7751-1-bottaawesome633@gmail.com> References: <20240824221031.7751-1-bottaawesome633@gmail.com> Precedence: bulk X-Mailing-List: linux-ext4@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Add a test case to ensure that no new name string literal will be created in lockdep_set_subclass(), otherwise a warning will be triggered in look_up_lock_class(). Add this to catch the problem in the future. Signed-off-by: Ahmed Ehab --- v5->v6: - Changed the subject and changelog to be in imperative format lib/locking-selftest.c | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) diff --git a/lib/locking-selftest.c b/lib/locking-selftest.c index 6f6a5fc85b42..2b4650bdf833 100644 --- a/lib/locking-selftest.c +++ b/lib/locking-selftest.c @@ -2710,6 +2710,32 @@ static void local_lock_3B(void) } +static void lock_class_subclass_X1(void) +{ + const char *name_before_setting_subclass = rwsem_X1.dep_map.name; + const char *name_after_setting_subclass; + + lockdep_set_subclass(&rwsem_X1, 1); + name_after_setting_subclass = rwsem_X1.dep_map.name; + DEBUG_LOCKS_WARN_ON(name_before_setting_subclass != name_after_setting_subclass); +} + +/* + * after setting the subclass the lockdep_map.name changes + * if we initialize a new string literal for the subclass + * we will have a new name pointer + */ +static void class_subclass_X1_name_test(void) +{ + printk(" --------------------------------------------------------------------------\n"); + printk(" | class and subclass name test|\n"); + printk(" ---------------------\n"); + + print_testname("lock class and subclass same name"); + dotest(lock_class_subclass_X1, SUCCESS, LOCKTYPE_RWSEM); + pr_cont("\n"); +} + static void local_lock_tests(void) { printk(" --------------------------------------------------------------------------\n"); @@ -2920,6 +2946,8 @@ void locking_selftest(void) dotest(hardirq_deadlock_softirq_not_deadlock, FAILURE, LOCKTYPE_SPECIAL); pr_cont("\n"); + class_subclass_X1_name_test(); + if (unexpected_testcase_failures) { printk("-----------------------------------------------------------------\n"); debug_locks = 0; -- 2.45.2