From patchwork Wed Jan 10 15:59:47 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marco Pagani X-Patchwork-Id: 762608 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5A41E4C3A5 for ; Wed, 10 Jan 2024 15:59:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="WMrsvWd1" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1704902397; 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=XQnGeG1QGEu/QBtp4/TBUL4MRasK2rgYQhSF+ZicemU=; b=WMrsvWd17oLCmT/9W6JkzBX+p+Dwzb92qj4j0s9uP0n4VX1sypNbxsfYP8DxSPwXQAFEae bWJRlV7xpx51URsfSw9KX7i/TRIMQymeXTlobh+GH5Dhrm3K3Kw2bL08krkh9TP4tNpkUd 6NhQlHlUaYKwcnXiNK/1FMYx3q8ttHc= Received: from mail-qk1-f199.google.com (mail-qk1-f199.google.com [209.85.222.199]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-259-AjRjoeYRO7-moMEMwbISoQ-1; Wed, 10 Jan 2024 10:59:56 -0500 X-MC-Unique: AjRjoeYRO7-moMEMwbISoQ-1 Received: by mail-qk1-f199.google.com with SMTP id af79cd13be357-7831be985c0so517707685a.3 for ; Wed, 10 Jan 2024 07:59:55 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1704902395; x=1705507195; 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=XQnGeG1QGEu/QBtp4/TBUL4MRasK2rgYQhSF+ZicemU=; b=D+zMMkTD5vn4hB/f9y0JQjlPb0BantH5dCqpbrsrQ6CUxaPG+ysUCdZabfp3WBa/ID RVg7RJ3NhxwlwHXO4Mh1EyqY+EzorUQTyi00A3KsB4PR2CqGoOppagPEcf4tv4dIdlf5 kbyIkhBGvgWv1qtqgnpRPoa8K811N70IxzcFsH2e7OhmavgC9sz/EFZwUNsCBlpQdYmk c9gRpqlAaCGzT2FOyU2U/H3Qxi22heMsYZu/455Gb66PEpV5e57GiCy3Hfl/iY3915Z+ pGsy7vkB6oMQjCvUS8wU5R87bc+pJunZA1PBNPp8P0M1AD+u5TLilHex3eICVRWiYcev O1ug== X-Gm-Message-State: AOJu0YxfGhCJ7RoAGa4AG+mPRoPmVcd2olXs4nKTPJnwS8JUHF7e1U6r X69FSqm0zHUPYPs+Iq7SEQbkwpajAfFdqeIVDlG9Nji1dPDJttc1D1Mds/wr0oVYlzKf+thoqS+ Rwcaw2RlCzBFLQGEoK6uf0E+4lDuBpK+Fk7E= X-Received: by 2002:a05:620a:5604:b0:781:a2bc:3211 with SMTP id vu4-20020a05620a560400b00781a2bc3211mr1186461qkn.128.1704902395533; Wed, 10 Jan 2024 07:59:55 -0800 (PST) X-Google-Smtp-Source: AGHT+IH/bzCATczOMB0vRgD1epB1FaXF/PgxKumauea4s3H5r12+zW5Kxf78GIo1oE4XXqbp03PmNA== X-Received: by 2002:a05:620a:5604:b0:781:a2bc:3211 with SMTP id vu4-20020a05620a560400b00781a2bc3211mr1186454qkn.128.1704902395222; Wed, 10 Jan 2024 07:59:55 -0800 (PST) Received: from klayman.redhat.com (net-2-34-31-72.cust.vodafonedsl.it. [2.34.31.72]) by smtp.gmail.com with ESMTPSA id z11-20020a05620a08cb00b00783206b9fedsm1691930qkz.86.2024.01.10.07.59.53 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 10 Jan 2024 07:59:54 -0800 (PST) From: Marco Pagani To: Brendan Higgins , David Gow , Jinjie Ruan , Rae Moar , Shuah Khan Cc: Marco Pagani , Richard Fitzgerald , Javier Martinez Canillas , linux-kselftest@vger.kernel.org, kunit-dev@googlegroups.com, linux-kernel@vger.kernel.org Subject: [PATCH v4] kunit: run test suites only after module initialization completes Date: Wed, 10 Jan 2024 16:59:47 +0100 Message-ID: <20240110155948.90964-1-marpagan@redhat.com> X-Mailer: git-send-email 2.43.0 Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 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. v4: - rebased on 6.8 - noted that kunit_filter_suites() must return a virtual address 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()") Reviewed-by: David Gow Tested-by: Rae Moar Tested-by: Richard Fitzgerald Reviewed-by: Javier Martinez Canillas Signed-off-by: Marco Pagani Tested-by: Geert Uytterhoeven --- lib/kunit/executor.c | 4 ++++ lib/kunit/test.c | 14 +++++++++++--- 2 files changed, 15 insertions(+), 3 deletions(-) base-commit: 539e582a375dedee95a4fa9ca3f37cdb25c441ec diff --git a/lib/kunit/executor.c b/lib/kunit/executor.c index 717b9599036b..689fff2b2b10 100644 --- a/lib/kunit/executor.c +++ b/lib/kunit/executor.c @@ -146,6 +146,10 @@ void kunit_free_suite_set(struct kunit_suite_set suite_set) kfree(suite_set.start); } +/* + * Filter and reallocate test suites. Must return the filtered test suites set + * allocated at a valid virtual address or NULL in case of error. + */ struct kunit_suite_set kunit_filter_suites(const struct kunit_suite_set *suite_set, const char *filter_glob, diff --git a/lib/kunit/test.c b/lib/kunit/test.c index f95d2093a0aa..31a5a992e646 100644 --- a/lib/kunit/test.c +++ b/lib/kunit/test.c @@ -17,6 +17,7 @@ #include #include #include +#include #include "debugfs.h" #include "device-impl.h" @@ -801,12 +802,19 @@ static void kunit_module_exit(struct module *mod) }; const char *action = kunit_action(); + /* + * 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); - if (suite_set.start) - kunit_free_suite_set(suite_set); + kunit_free_suite_set(suite_set); } static int kunit_module_notify(struct notifier_block *nb, unsigned long val, @@ -816,12 +824,12 @@ static int kunit_module_notify(struct notifier_block *nb, unsigned long val, 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;