From patchwork Wed Sep 4 17:29:31 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: SeongJae Park X-Patchwork-Id: 825438 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 415FD10A12; Wed, 4 Sep 2024 17:29:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725470982; cv=none; b=o52p+/q5RoFk5z7yRk1yqc53ySnXH3Myw7bKj1B2jEysDGp8ZXANFf7QDznLg/rbbz2P0xLRlf/YWJu6EMSEnWaqK9vvCPj7rPuohIaex+WFw8VjqTG86SJLufndXyfsOEVWaeXnxr8f4yWbOzAWTTgUYCwxn4TXztGX4WvVqd4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725470982; c=relaxed/simple; bh=g2SvYEsNRUISamOgyu6CD7Iy+rnUtlzFhcKFNMBbW+o=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=W3cJ48+6RCXwMjy2WB/XstyM6VMELpXV/kkh1uV97sFtbv9GkwWQvVAcZr9vgOwFEK1Fu1KJag/CvXi26R19F/PGjac7Ts7PEJe2WiEmJ2m3XbLGY7QIL/2Eecr+Eq6JRuuhTjIWRskgDfqfsG7G+4nCV6IiCPNDnnWyyYn13S0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Zf8qnOV4; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Zf8qnOV4" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B2D39C4CEC2; Wed, 4 Sep 2024 17:29:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1725470981; bh=g2SvYEsNRUISamOgyu6CD7Iy+rnUtlzFhcKFNMBbW+o=; h=From:To:Cc:Subject:Date:From; b=Zf8qnOV4xVEXtXImMjjoQ/DlyyKTurmsFg3Sn05aCnHyFRrQOWLthCj5ZcGmKdLAh wFcoCGDddKU40xe0pqdzgyVXOCwQMKv1DQuHhVi2mi406cM53G8vic1HXtCqKnm+Hs gYcCqMhy+hvi+i0op9ujV83L+n+JktjTMubSLiezAKKoN0BxaN+KbkIJG/4Yn2uPc5 DBVVAwKKkqI0ZrVLN1T/v5xdQ5UtfELgG5BOkjkkUz+/zB7n4ECdc2I1LReLUcfi2r 4U1/sG3ax9xfvJZwYS9Kl4/0e8Y7fLJdkOa+LiGM1kBjwYm9XsDLlba4exX9XFuJ4e usaZEqvlOLUpw== From: SeongJae Park To: Andrew Morton Cc: SeongJae Park , "Liam R. Howlett" , David Hildenbrand , "Matthew Wilcox (Oracle)" , Brendan Higgins , David Gow , damon@lists.linux.dev, linux-mm@kvack.org, kunit-dev@googlegroups.com, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org, Guenter Roeck , "Liam R . Howlett" Subject: [PATCH v2] mm/damon/tests/vaddr-kunit: init maple tree without MT_FLAGS_LOCK_EXTERN Date: Wed, 4 Sep 2024 10:29:31 -0700 Message-Id: <20240904172931.1284-1-sj@kernel.org> X-Mailer: git-send-email 2.39.2 Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 damon_test_three_regions_in_vmas() initializes a maple tree with MM_MT_FLAGS. The flags contains MT_FLAGS_LOCK_EXTERN, which means mt_lock of the maple tree will not be used. And therefore the maple tree initialization code skips initialization of the mt_lock. However, __link_vmas(), which adds vmas for test to the maple tree, uses the mt_lock. In other words, the uninitialized spinlock is used. The problem becomes clear when spinlock debugging is turned on, since it reports spinlock bad magic bug. Fix the issue by excluding MT_FLAGS_LOCK_EXTERN from the maple tree initialization flags. Note that we don't use empty flags to make it further similar to the usage of mm maple tree, and to be prepared for possible future changes, as suggested by Liam. Reported-by: Guenter Roeck Closes: https://lore.kernel.org/1453b2b2-6119-4082-ad9e-f3c5239bf87e@roeck-us.net Fixes: d0cf3dd47f0d ("damon: convert __damon_va_three_regions to use the VMA iterator") Suggested-by: Liam R. Howlett Signed-off-by: SeongJae Park --- Changes from v1 (https://lore.kernel.org/20240904004534.1189-1-sj@kernel.org) - Keep lock usage and update the initialization flags (Liam) - Fix a typo: s/celar/clear/ (Guenter) mm/damon/tests/vaddr-kunit.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/damon/tests/vaddr-kunit.h b/mm/damon/tests/vaddr-kunit.h index 83626483f82b..a339d117150f 100644 --- a/mm/damon/tests/vaddr-kunit.h +++ b/mm/damon/tests/vaddr-kunit.h @@ -77,7 +77,7 @@ static void damon_test_three_regions_in_vmas(struct kunit *test) (struct vm_area_struct) {.vm_start = 307, .vm_end = 330}, }; - mt_init_flags(&mm.mm_mt, MM_MT_FLAGS); + mt_init_flags(&mm.mm_mt, MT_FLAGS_ALLOC_RANGE | MT_FLAGS_USE_RCU); if (__link_vmas(&mm.mm_mt, vmas, ARRAY_SIZE(vmas))) kunit_skip(test, "Failed to create VMA tree");