From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 A198B486E78; Mon, 28 Sep 2026 08:53:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790585602; cv=none; b=BnskpN+yf8x6O4ueF0PlAJUkpF9YSHvUPsUOQ4gcV8PIWj34+KTpvy4/XYJkGztSgq9PEiUZoCJ3CIHrZWmBGdQs1d+zk5hIA4LupRYwSi76HIznBOX22vAxp0yyDWIN76z4dA0+Dijk1gBUCFoaa8y45UeK2fvs+oV8Fh4GjlE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790585602; c=relaxed/simple; bh=a1gjw015DETcieT1DcIKm+L9rR/PU6Ll3zjww55sHRo=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=LTFFfY1FENiVqhuwfkMpnoBYFogiGHtWC9phrCzBobbttbKPkk1ZwVtDCjdtdnrc4IopsKjEpSaBh+dXSlcEvTtpcM1DaMV+U4o7bLlr+Jrc5YzkWc9LV8Z4zEJbW3t9igHfLglyxifM0rT1VLCJBryqJKyGXq4nrTvbo/As4qE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=hrFYJfwf; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="hrFYJfwf" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 110201F00893; Mon, 28 Sep 2026 08:53:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1790585600; bh=5PVeGOJnaKCpJJY0+kbJzTfUxuIOeJRjTWg+Uf9bzrY=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=hrFYJfwfCcGmTGKwfH4kA1bByopbzivdG95gwg9QPSMCGENY3BYLnIJuz03bHzn1m Auytg8u9pwWvX2XtvlywvDnrVK9KT2YmJWuYTRSbLMbIj+BWVo2ucIYvOYthdKZo94 pvMD3pulkrFS7Hx+dQ29+b9K424ZJRXVXUIdZELDA+71CmEW2mr3AlD8jxMhNjScX8 zoQBOjv3qbDWZPo0Fo8+qslY0f1ixzEYJj3rMOf4XlhTW8tyVOiwxfJmzpuI1Xq/xL hxqF2tmWBUKuwUZOBJuOxhfybAj4egnRehaLH8BOnjgHTWhDupwm49rZ/RDiMOUB0N YeqNkMD711OUw== Message-ID: <4e4223f4-dfec-4e82-97fe-25ae3a3b0f73@kernel.org> Date: Mon, 28 Sep 2026 10:53:10 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v3 2/2] selftests/mm: add tests for UFFDIO_MOVE of a uffd-protected swap entry To: Donggeun Yoo , akpm@linux-foundation.org, rppt@kernel.org Cc: peterx@redhat.com, surenb@google.com, aarcange@redhat.com, ljs@kernel.org, liam@infradead.org, vbabka@kernel.org, mhocko@suse.com, shuah@kernel.org, kirill@shutemov.name, linux-mm@kvack.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org References: <20260926124145.2878520-1-donggeunyoo.kernel@gmail.com> <20260926124145.2878520-3-donggeunyoo.kernel@gmail.com> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit On 9/26/26 14:41, Donggeun Yoo wrote: > Move a swapped-out page out of a write-protected or RWP-protected area into > a destination registered for missing faults only, and read pagemap bit 57 > at the destination. The destination was never protected, so the bit must > be clear. > > Assisted-by: LLM > Signed-off-by: Donggeun Yoo > --- > tools/testing/selftests/mm/uffd-unit-tests.c | 84 ++++++++++++++++++++ > 1 file changed, 84 insertions(+) > > diff --git a/tools/testing/selftests/mm/uffd-unit-tests.c b/tools/testing/selftests/mm/uffd-unit-tests.c > index ef9b3956bdcfd..580178630eded 100644 > --- a/tools/testing/selftests/mm/uffd-unit-tests.c > +++ b/tools/testing/selftests/mm/uffd-unit-tests.c > @@ -2037,6 +2037,75 @@ 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 or RWP-protected area > + * must not carry the uffd bit into a destination registered for missing > + * faults only: 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_test_common(uffd_global_test_opts_t *gopts, > + bool rwp) > +{ > + unsigned long page_size = gopts->page_size; > + struct uffdio_move move = { }; > + int pagemap_fd; > + > + if (rwp) { > + if (uffd_register_rwp(gopts->uffd, gopts->area_src, page_size)) > + err("register src failure"); > + } else if (uffd_register(gopts->uffd, gopts->area_src, page_size, > + false, true, false)) { > + err("register src failure"); > + } if () > + if (uffd_register(gopts->uffd, gopts->area_dst, page_size, > + true, false, false)) > + err("register dst failure"); > + > + if (rwp) > + rwprotect_range(gopts->uffd, (unsigned long)gopts->area_src, > + page_size, true); > + else > + wp_range(gopts->uffd, (unsigned long)gopts->area_src, > + page_size, true); > + > + pagemap_fd = pagemap_open(); > + if (madvise(gopts->area_src, page_size, MADV_PAGEOUT)) > + err("MADV_PAGEOUT"); > + 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 bit moved into an area registered for missing faults only"); > + 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 void uffd_move_swap_wp_test(uffd_global_test_opts_t *gopts, > + uffd_test_args_t *targs) > +{ > + uffd_move_swap_test_common(gopts, false); > +} > + > +static void uffd_move_swap_rwp_test(uffd_global_test_opts_t *gopts, > + uffd_test_args_t *targs) > +{ > + uffd_move_swap_test_common(gopts, true); > +} > + > static bool > uffdio_verify_results(const char *name, int ret, int error, long result) > { > @@ -2359,6 +2428,21 @@ 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 = "move-swap-rwp", > + .uffd_fn = uffd_move_swap_rwp_test, > + .mem_targets = MEM_ANON, > + .uffd_feature_required = UFFD_FEATURE_MOVE | UFFD_FEATURE_RWP, > + .test_case_ops = &uffd_move_test_case_ops, > + }, > { > .name = "wp-fork", > .uffd_fn = uffd_wp_fork_test, -- Cheers, David