From nobody Fri Apr 3 08:09:42 2026 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 E2E143E6DDD for ; Fri, 20 Mar 2026 18:40:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774032032; cv=none; b=eWmP3qlajdS5e7ftrEG+KVwbaQh2f1WPyBtX2ZJ8KFE8L8VoSAe8J0ejCqvCgT7Ydnqml7O8jakulLKReRlIKNvSy7x0U1+niHOK5J61+0VjwM+RSNBGbJ+lkVWlkgXP1v96fnH84W5Oca7VGp3CcXM4rcSCuIQScHB/ZWAWbTw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774032032; c=relaxed/simple; bh=1BkzluDODaIlh1zrFVpM2Lp05oXawlpqUBD32AskLX8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=KD5kKNiILnXOOvqbFchEgbd0VzWw5l2nfJIkuDKCeBCKicf29MA59QgIeELsA0nmpsogX9Pb9ftJGXZSFIKM5LRFvgmwNdi4fMBTNDcdgtq1eY/GHPiteZ6Bj+BShZikFE4jOYVXyfcPZyfYoD5udisml1NcVygRyyeaXPuCST0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=JQTPSPeo; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine 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="JQTPSPeo" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1774032030; 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: in-reply-to:in-reply-to:references:references; bh=6scTfZdpNdLDWYVNA+QDpQesm+T9ccRyDBvKNA1+6k8=; b=JQTPSPeovqzGSCqWVSdab8u373zNTRO+hfSCXowwTU8FmjNaVpojma+X3H9aL7yD1EIvNN DX1c9OsoAgWp5hMc26Ps6rLDuYZllFlfa+kVR0jH6hl7P6ktDuS9+iG4UZGJJpYFPDQsgE 9XF1UP3wn0/yPuAYt7xQXNh9eqi2Flk= Received: from mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-605-5SC89gtyOjGTIYdEmEjR1A-1; Fri, 20 Mar 2026 14:40:28 -0400 X-MC-Unique: 5SC89gtyOjGTIYdEmEjR1A-1 X-Mimecast-MFC-AGG-ID: 5SC89gtyOjGTIYdEmEjR1A_1774032026 Received: from mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.17]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 847B21955F6A; Fri, 20 Mar 2026 18:40:26 +0000 (UTC) Received: from fedora.redhat.com (unknown [10.22.80.202]) by mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 204B81953944; Fri, 20 Mar 2026 18:40:23 +0000 (UTC) From: Audra Mitchell To: akpm@linux-foundation.org Cc: david@kernel.org, ljs@kernel.org, Liam.Howlett@oracle.com, vbabka@kernel.org, rppt@kernel.org, surenb@google.com, mhocko@suse.com, shuah@kernel.org, usama.anjum@collabora.com, colin.i.king@gmail.com, avagin@google.com, linux-kselftest@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH] selftests/mm: Fix soft-dirty kselftest supported check Date: Fri, 20 Mar 2026 14:39:15 -0400 Message-ID: <20260320184010.759461-2-audra@redhat.com> In-Reply-To: <20260320184010.759461-1-audra@redhat.com> References: <20260320184010.759461-1-audra@redhat.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 3.0 on 10.30.177.17 Content-Type: text/plain; charset="utf-8" On architectures with separate user address space, such as s390 or those without an MMU, the soft-dirty kselftest may fail when checking to see if the feature is supported. # -------------------- # running ./soft-dirty # -------------------- # TAP version 13 # 1..15 # Bail out! PAGEMAP_SCAN succeeded unexpectedly # # Totals: pass:0 fail:0 xfail:0 xpass:0 skip:0 error:0 # [FAIL] not ok 1 soft-dirty # exit=3D1 # SUMMARY: PASS=3D0 SKIP=3D0 FAIL=3D1 The soft-dirty test will initate an ioctl with the PAGEMAP_SCAN flag with an invalid address for the page_region. This is done intentionally to have the ioctl return with an expected EFAULT and with the correct categories returned. However, on architectures with separate user address space, such as s390 or those without an MMU, the call to __access_ok (used to validate the variables provided with the ioctl) will always return true and we will not fail as expected. if (IS_ENABLED(CONFIG_ALTERNATE_USER_ADDRESS_SPACE) || !IS_ENABLED(CONFIG_MMU)) return true; Let's simplify the check for PAGEMAP_SCAN and provide a valid page_region address so that we get a non-errno return if it is supported. Fixes: 600bca580579 ("selftests/mm: check that PAGEMAP_SCAN returns correct= categories") Signed-off-by: Audra Mitchell --- tools/testing/selftests/mm/vm_util.c | 24 +++++++++++++++--------- 1 file changed, 15 insertions(+), 9 deletions(-) diff --git a/tools/testing/selftests/mm/vm_util.c b/tools/testing/selftests= /mm/vm_util.c index a6d4ff7dfdc0..82998406b335 100644 --- a/tools/testing/selftests/mm/vm_util.c +++ b/tools/testing/selftests/mm/vm_util.c @@ -67,20 +67,26 @@ static uint64_t pagemap_scan_get_categories(int fd, cha= r *start) } =20 /* `start` is any valid address. */ -static bool pagemap_scan_supported(int fd, char *start) +static bool pagemap_scan_supported(int fd) { + const size_t pagesize =3D getpagesize(); static int supported =3D -1; - int ret; + struct page_region r; + void *test_area; =20 if (supported !=3D -1) return supported; =20 - /* Provide an invalid address in order to trigger EFAULT. */ - ret =3D __pagemap_scan_get_categories(fd, start, (struct page_region *) ~= 0UL); - if (ret =3D=3D 0) - ksft_exit_fail_msg("PAGEMAP_SCAN succeeded unexpectedly\n"); - - supported =3D errno =3D=3D EFAULT; + test_area =3D mmap(0, pagesize, PROT_READ | PROT_WRITE, + MAP_ANONYMOUS | MAP_PRIVATE, 0, 0); + if (test_area =3D=3D MAP_FAILED) { + ksft_print_msg("WARN: mmap() failed: %s\n", strerror(errno)); + supported =3D 0; + } else { + supported =3D __pagemap_scan_get_categories(fd, test_area, &r) >=3D 0; + ksft_print_msg("errno: %d\n", errno); + munmap(test_area, pagesize); + } =20 return supported; } @@ -90,7 +96,7 @@ static bool page_entry_is(int fd, char *start, char *desc, { bool m =3D pagemap_get_entry(fd, start) & pagemap_flags; =20 - if (pagemap_scan_supported(fd, start)) { + if (pagemap_scan_supported(fd)) { bool s =3D pagemap_scan_get_categories(fd, start) & pagescan_flags; =20 if (m =3D=3D s) --=20 2.52.0