From nobody Sun Dec 28 17:28:54 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2D752C4167B for ; Wed, 6 Dec 2023 15:07:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1442423AbjLFPHp (ORCPT ); Wed, 6 Dec 2023 10:07:45 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37728 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1379115AbjLFPHm (ORCPT ); Wed, 6 Dec 2023 10:07:42 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 62302D46 for ; Wed, 6 Dec 2023 07:07:48 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1701875267; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=/JBJQVO5XBoc9lUdPYm1Dkdtmlp9iMHA1ds5P3k5wtk=; b=JNeHjo0Zqd9VpCbcepdiHQ/VtVqFsj8d7hTLCtMGjOVyw3IGmXb9keZTr8jGvdbft/XHr+ V7EsqIt77n6wqBkAL29HMKBqFIC856VV1JYWHY6nzypNsdYW2uM5/XkG9W0qUTZnb+964q d2eAR+TaHSiM6fDA5lrd7KZ//SVYNVw= Received: from mail-wr1-f72.google.com (mail-wr1-f72.google.com [209.85.221.72]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-320-AU8IRVTjNYqiuh7hhJ6ozg-1; Wed, 06 Dec 2023 10:07:43 -0500 X-MC-Unique: AU8IRVTjNYqiuh7hhJ6ozg-1 Received: by mail-wr1-f72.google.com with SMTP id ffacd0b85a97d-332e71b8841so800651f8f.0 for ; Wed, 06 Dec 2023 07:07:39 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1701875258; x=1702480058; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=/JBJQVO5XBoc9lUdPYm1Dkdtmlp9iMHA1ds5P3k5wtk=; b=mzwJnfibU39gaPoOT8TZG3ZbjLjUnCw5cWOHKNnrrLB293/tgnxy5xsizpisti53dP ScyczTXzWcGbOtbOEeVsASXqmycoQ4rou6kHDG4gvHVwbNGsa7ulMvRm1mNxtOmfe+Gl kr0f7Aq5ZwHRszsBKxGqch0wz/DTkQ/NVnXF2fi2Ge6YCot0mPpZcvC9J9/tu5CTR84n ZDZjAAtA/mq0cJyNCNZxpzO017cm+UIqFcbjcP3lPz6CQWUGXmab/BVrwmU6bK30PUl2 NuKeJLcPoqT4w5pgWVfODeUIjm6dG01LD8m4JUREdgyu4rgK2DuTV13snSrmm76N3glc XGgg== X-Gm-Message-State: AOJu0YzArj3lvFMGD4vgDHS6s/90KJz+pERYru+c+R56AwSorcyrsEHu 24CJhzmTmMdSsZ3CGHGqfFSGO5i6bfC29yy9v557srR7HcVepBg53My5ZM8Zt47fHHyIH5uRrSU 4bKlqqNrBioeSrXln2w1kGQo= X-Received: by 2002:a5d:4009:0:b0:333:5258:68ef with SMTP id n9-20020a5d4009000000b00333525868efmr692840wrp.68.1701875258351; Wed, 06 Dec 2023 07:07:38 -0800 (PST) X-Google-Smtp-Source: AGHT+IHLa1/yFQDJ3QsgPuJIOsVfygTgkEWMxKZQhHwYBT6FHhXNXPic4hIBJCiXWvnVGxjbXDr5Dw== X-Received: by 2002:a5d:4009:0:b0:333:5258:68ef with SMTP id n9-20020a5d4009000000b00333525868efmr692834wrp.68.1701875257975; Wed, 06 Dec 2023 07:07:37 -0800 (PST) Received: from klayman.redhat.com (net-2-34-30-38.cust.vodafonedsl.it. [2.34.30.38]) by smtp.gmail.com with ESMTPSA id c1-20020adfa301000000b003333a216682sm11896497wrb.97.2023.12.06.07.07.37 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 06 Dec 2023 07:07:37 -0800 (PST) From: Marco Pagani To: Brendan Higgins , David Gow , Shuah Khan , Jinjie Ruan , Rae Moar Cc: Marco Pagani , Richard Fitzgerald , Javier Martinez Canillas , linux-kselftest@vger.kernel.org, kunit-dev@googlegroups.com, linux-kernel@vger.kernel.org Subject: [PATCH v3] kunit: run test suites only after module initialization completes Date: Wed, 6 Dec 2023 16:07:28 +0100 Message-ID: <20231206150729.54604-1-marpagan@redhat.com> X-Mailer: git-send-email 2.43.0 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Commit 2810c1e99867 ("kunit: Fix wild-memory-access bug in kunit_free_suite_set()") fixed a wild-memory-access bug that could have happened during the loading phase of test suites built and executed as loadable modules. However, it also introduced a problematic side effect that causes test suites modules to crash when they attempt to register fake devices. When a module is loaded, it traverses the MODULE_STATE_UNFORMED and MODULE_STATE_COMING states before reaching the normal operating state MODULE_STATE_LIVE. Finally, when the module is removed, it moves to MODULE_STATE_GOING before being released. However, if the loading function load_module() fails between complete_formation() and do_init_module(), the module goes directly from MODULE_STATE_COMING to MODULE_STATE_GOING without passing through MODULE_STATE_LIVE. This behavior was causing kunit_module_exit() to be called without having first executed kunit_module_init(). Since kunit_module_exit() is responsible for freeing the memory allocated by kunit_module_init() through kunit_filter_suites(), this behavior was resulting in a wild-memory-access bug. Commit 2810c1e99867 ("kunit: Fix wild-memory-access bug in kunit_free_suite_set()") fixed this issue by running the tests when the module is still in MODULE_STATE_COMING. However, modules in that state are not fully initialized, lacking sysfs kobjects. Therefore, if a test module attempts to register a fake device, it will inevitably crash. This patch proposes a different approach to fix the original wild-memory-access bug while restoring the normal module execution flow by making kunit_module_exit() able to detect if kunit_module_init() has previously initialized the tests suite set. In this way, test modules can once again register fake devices without crashing. This behavior is achieved by checking whether mod->kunit_suites is a virtual or direct mapping address. If it is a virtual address, then kunit_module_init() has allocated the suite_set in kunit_filter_suites() using kmalloc_array(). On the contrary, if mod->kunit_suites is still pointing to the original address that was set when looking up the .kunit_test_suites section of the module, then the loading phase has failed and there's no memory to be freed. v3: - add a comment to clarify why the start address is checked v2: - add include Fixes: 2810c1e99867 ("kunit: Fix wild-memory-access bug in kunit_free_suite= _set()") Tested-by: Richard Fitzgerald Reviewed-by: Javier Martinez Canillas Signed-off-by: Marco Pagani Reviewed-by: David Gow Tested-by: Rae Moar --- lib/kunit/test.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) diff --git a/lib/kunit/test.c b/lib/kunit/test.c index 7aceb07a1af9..3263e0d5e0f6 100644 --- a/lib/kunit/test.c +++ b/lib/kunit/test.c @@ -16,6 +16,7 @@ #include #include #include +#include =20 #include "debugfs.h" #include "hooks-impl.h" @@ -775,12 +776,19 @@ static void kunit_module_exit(struct module *mod) }; const char *action =3D kunit_action(); =20 + /* + * Check if the start address is a valid virtual address to detect + * if the module load sequence has failed and the suite set has not + * been initialized and filtered. + */ + if (!suite_set.start || !virt_addr_valid(suite_set.start)) + return; + if (!action) __kunit_test_suites_exit(mod->kunit_suites, mod->num_kunit_suites); =20 - if (suite_set.start) - kunit_free_suite_set(suite_set); + kunit_free_suite_set(suite_set); } =20 static int kunit_module_notify(struct notifier_block *nb, unsigned long va= l, @@ -790,12 +798,12 @@ static int kunit_module_notify(struct notifier_block = *nb, unsigned long val, =20 switch (val) { case MODULE_STATE_LIVE: + kunit_module_init(mod); break; case MODULE_STATE_GOING: kunit_module_exit(mod); break; case MODULE_STATE_COMING: - kunit_module_init(mod); break; case MODULE_STATE_UNFORMED: break; base-commit: 33cc938e65a98f1d29d0a18403dbbee050dcad9a --=20 2.43.0