From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj2-f12.google.com (mail-pj2-f12.google.com [74.125.227.140]) (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 467BD3033EC for ; Sat, 19 Sep 2026 00:46:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=74.125.227.140 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789778809; cv=none; b=K1HVk31AFG6rli0GpGGeD/PjXCGa7mFFVyPS3w/G7519iNf9qz/onUGbuiKRahgs/IGWS2f5uCKksa202gXymJ5SVxbTHWOPO7vV4B+ea+usTnGlOfqWHxEiAHCMjLpo6fpOa9u6CW3CHF1K80Pkm5lqqByAo4r67X3pEdjPy2w= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789778809; c=relaxed/simple; bh=HeQwU2YYW2ammaacyTh52hjG4IGzTEGbQ0IVGSCt54A=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=M1sWQJ2v/wwwj+fvqSBE1BQ/CxH7hk9wmDr27awfvQGciQnmTLRm6O0U6d7CNtbTcUjHa62InvsWu3iV1M/T+T3kuMuQaoelsxqNr3umT0rn3XP/sDhIuI2l6FeWecVsa6sxbbzC/fVs+vHiDuGx18gysGpy7iS0HOX1shbsBmE= 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=LSzNLoS2; arc=none smtp.client-ip=74.125.227.140 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="LSzNLoS2" Received: by mail-pj2-f12.google.com with SMTP id 98e67ed59e1d1-39b5b07ec78so966963a91.3 for ; Fri, 18 Sep 2026 17:46:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1789778803; x=1790383603; 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:content-type; bh=uyjZLL0sA6T5K+I6SLCzFZO+c82gRPna/G98UbpeCXU=; b=LSzNLoS2eCNxSfyyJZ56Eq+Zfi/AYKURigBiNiLp+GWv7PFSBkqXWLgi1dNwBgpUQi 8mRjqef1zXCDmxUnWfY+c45LyFpZU/JmR2TCvQtIhiJSY+0cq9jzmatY/bhKkyvuifL3 MExSzcvLoPAX1+uWxDtjWvD1SbB4AHEWZcUHAJQK9eM+1R8WYcHLhVbf1Z6LOucZn7LW ZU9oR9gqCSYVstCLGyBiom1cGmC4iGdxaN2pyh3G7j2bPfeg3d/oyBOi69TnKJ2UH/QH tLheUA7uk/vF4eeJr+JjR88sy5Oessa6jc/IfbSWS1laBb3yK3+HKIfFys44eLD2gDhW RvaQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1789778803; x=1790383603; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to:content-type; bh=uyjZLL0sA6T5K+I6SLCzFZO+c82gRPna/G98UbpeCXU=; b=P6HLm3mW/TPVWk70LxSjtvxSVnnYpY2cOoIl3ZRA0me7vhqtnfQndJzxLKp56nNHyz ZKiVx+3M5M6muQUD658udnhLu9yxnkBXFImUGdzTAfpSajDarNXaC+sdPlT1gfq2xZ/t 5bjYIMqzKlyY2TVLmgBCXnAsUDOANdxXH0nRyFVox6Zzc8a2z2sqvFWOU4qZQXDQF4I8 RbuliwWrdmozbtk3Srcx36Q9XtG0toIn0akL+xMZR8St1Gen5/qfoNShXalL5voarJ38 EAc7TROMdLmeo5t4J2ESFQiH81O3JO0kQyDHc3zrhRnkxXe+8ad1Ep4Xfqa8IEobhrL3 nEUg== X-Forwarded-Encrypted: i=1; AKwUvBz80+HX7fzwdtYiEbwqLiqAK0hqeAje1eyOIZguiRAimmWkIijgwzGLdwGXwqzln5Z8on55TdANGXOuzac=@vger.kernel.org X-Gm-Message-State: AFuF++mJXcwDB1zZHE5Orwxqtc8xXRoi6tgdhadhq/M7rXux4ezmto3Z 3aeKEcQp2zOplED+J8scXb/P0DRjLgMS+KmgtvyrdDfHDK/mbg0MFTw= X-Gm-Gg: AYBFou2IK+unKrL375JcTY0m1TI+h5LRFg9k47v9HQgGevoanQ76hHHwYIX/QwCEhKO KZfdZl4FB1gY0y8lfccL3vKuQOjyYHbIaayafcUVAiQrQdix33k0yAmdb/KpeQKtUSpOr2sSD/0 YfY+1xPsR2LBdaO7UP7PazpAI6JXOauK4q0/66fq4BvmthPqwaA2sj4naQWESAfbQN1anNoa73d +mc2xNmct/OcPVUkEIygJVIUR5U37yBbuKymP9BJNIGYR9uB2XsIbChiGYKX+gYmDKzim3Fj/J2 WRzs+o9zrJFoT9NxwGB4SPihlLqP2yvcT9jT/k4thW8KdMsb3Dx9Pm1bti1Rsjw8Rj4l0Sc+npb dOY1RBaviTS/ViB5zW63MbfLX92CNBSpFCrniAK/KL1vZllUNAHvypJJJ3PEfYWBw0wuaxgGhSF 8iKmRbjWW7NXtgt2QKsFzDpw74W/aunqnAxAD22slvq05KNH+wqYC/3YLcnVJIMiAI/8c3NXsM7 4FtlnS9b1ucLCwrsL7/n/KPahYpCeKPyvrJ1Q== X-Received: by 2002:a17:90b:37cb:b0:39e:6c6a:2090 with SMTP id 98e67ed59e1d1-39e6c6a229fmr1913904a91.49.1789778803484; Fri, 18 Sep 2026 17:46:43 -0700 (PDT) Received: from ydg-Zenbook-14-UM3406GA ([2001:2d8:7f00:8c85:45e5:9e39:6356:6164]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-39e6c169dcdsm1927166a91.2.2026.09.18.17.46.39 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 18 Sep 2026 17:46:43 -0700 (PDT) From: Donggeun Yoo To: akpm@linux-foundation.org, rppt@kernel.org Cc: peterx@redhat.com, surenb@google.com, aarcange@redhat.com, david@kernel.org, ljs@kernel.org, liam@infradead.org, vbabka@kernel.org, mhocko@suse.com, shuah@kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org, donggeunyoo.kernel@gmail.com Subject: [PATCH v1 2/2] selftests/mm: add a test for UFFDIO_MOVE of a write-protected swap entry Date: Sat, 19 Sep 2026 09:46:30 +0900 Message-ID: <20260919004630.1159895-3-donggeunyoo.kernel@gmail.com> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260919004630.1159895-1-donggeunyoo.kernel@gmail.com> References: <20260919004630.1159895-1-donggeunyoo.kernel@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: 8bit Move a swapped-out page out of a write-protected area into a destination registered for missing faults only, and read pagemap bit 57 at the destination. The destination was never write-protected, so the bit must be clear. Signed-off-by: Donggeun Yoo --- tools/testing/selftests/mm/uffd-unit-tests.c | 61 ++++++++++++++++++++ 1 file changed, 61 insertions(+) diff --git a/tools/testing/selftests/mm/uffd-unit-tests.c b/tools/testing/selftests/mm/uffd-unit-tests.c index ef9b3956bdcf..ae8b718f0a27 100644 --- a/tools/testing/selftests/mm/uffd-unit-tests.c +++ b/tools/testing/selftests/mm/uffd-unit-tests.c @@ -2037,6 +2037,59 @@ static void uffd_move_pmd_split_test(uffd_global_test_opts_t *gopts, uffd_test_a uffd_move_pmd_handle_fault); } +/* + * Moving a swapped-out page out of a write-protected area must not carry the + * uffd-wp bit into a destination that is not write-protect registered: such a + * bit is never cleared afterwards, so pagemap keeps reporting the page as + * uffd-tracked. + * + * Needs a swap device; skipped if MADV_PAGEOUT cannot evict the page. + */ +static void uffd_move_swap_wp_test(uffd_global_test_opts_t *gopts, + uffd_test_args_t *targs) +{ + unsigned long page_size = gopts->page_size; + struct uffdio_move move = { }; + int pagemap_fd, i; + + if (uffd_register(gopts->uffd, gopts->area_src, page_size, + false, true, false)) + err("register src failure"); + if (uffd_register(gopts->uffd, gopts->area_dst, page_size, + true, false, false)) + err("register dst failure"); + + wp_range(gopts->uffd, (unsigned long)gopts->area_src, page_size, true); + + pagemap_fd = pagemap_open(); + for (i = 0; i < 100; i++) { + if (madvise(gopts->area_src, page_size, MADV_PAGEOUT)) + err("MADV_PAGEOUT"); + if (pagemap_is_swapped(pagemap_fd, gopts->area_src)) + break; + usleep(10000); + } + if (!pagemap_is_swapped(pagemap_fd, gopts->area_src)) { + uffd_test_skip("MADV_PAGEOUT did not swap the page; is swap enabled?"); + goto out; + } + + move.dst = (unsigned long)gopts->area_dst; + move.src = (unsigned long)gopts->area_src; + move.len = page_size; + if (ioctl(gopts->uffd, UFFDIO_MOVE, &move)) + err("UFFDIO_MOVE"); + + if (pagemap_get_entry(pagemap_fd, gopts->area_dst) & PM_UFFD_WP) + uffd_test_fail("uffd-wp bit moved into an area that is not write-protected"); + else + uffd_test_pass(); +out: + close(pagemap_fd); + uffd_unregister(gopts->uffd, gopts->area_src, page_size); + uffd_unregister(gopts->uffd, gopts->area_dst, page_size); +} + static bool uffdio_verify_results(const char *name, int ret, int error, long result) { @@ -2359,6 +2412,14 @@ uffd_test_case_t uffd_tests[] = { .uffd_feature_required = UFFD_FEATURE_MOVE, .test_case_ops = &uffd_move_test_pmd_case_ops, }, + { + .name = "move-swap-wp", + .uffd_fn = uffd_move_swap_wp_test, + .mem_targets = MEM_ANON, + .uffd_feature_required = UFFD_FEATURE_MOVE | + UFFD_FEATURE_PAGEFAULT_FLAG_WP, + .test_case_ops = &uffd_move_test_case_ops, + }, { .name = "wp-fork", .uffd_fn = uffd_wp_fork_test, -- 2.53.0