From nobody Tue Feb 10 05:26:56 2026 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 8279234D917; Wed, 7 Jan 2026 16:49:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767804556; cv=none; b=DHXHSrTiiP0yF1i4ZC2c1D/J8t6XOZqTSrpvQ6Tu8kbcggy+T+pgtyfiKIeFjmCyRGeB0HxmkVpZONXs+hmQEsnqOSoOkOKcQQ+jHdOdDQr7A827VpjTgIDO3/rEr0UvG5QTxdH+LpwwNN/LxttF3p/Y9YqiiDCo3p83NNr10wE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767804556; c=relaxed/simple; bh=JThi7RLwAirOPVgwT2JD5p1WRyNKU85M6QrfMprXfB8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=bPV8YHXGx9B6ybrwATot2O25NCDjMA9W7/xNYeaFhx4Iz4EJXmLP85MGBXkMi9vORU8xS8LpazTCHOc/208YWDcYVamScOh0zSCOVg+MOExH6ugABNoPSTUcshMMk7wl6EYruQVxU5TLw4t3EoeZ8INJ4MrJe83/74FloI9zaOk= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 98B71168F; Wed, 7 Jan 2026 08:48:53 -0800 (PST) Received: from e123572-lin.arm.com (e123572-lin.cambridge.arm.com [10.1.194.54]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 19AA43F5A1; Wed, 7 Jan 2026 08:48:58 -0800 (PST) From: Kevin Brodsky To: linux-mm@kvack.org, linux-kselftest@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Kevin Brodsky , Andrew Morton , David Hildenbrand , Lorenzo Stoakes , Mark Brown , Ryan Roberts , Shuah Khan , Usama Anjum Subject: [PATCH v2 6/8] selftests/mm: fix faulting-in code in pagemap_ioctl test Date: Wed, 7 Jan 2026 16:48:40 +0000 Message-ID: <20260107164842.3289559-7-kevin.brodsky@arm.com> X-Mailer: git-send-email 2.51.2 In-Reply-To: <20260107164842.3289559-1-kevin.brodsky@arm.com> References: <20260107164842.3289559-1-kevin.brodsky@arm.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 Content-Type: text/plain; charset="utf-8" One of the pagemap_ioctl tests attempts to fault in pages by memcpy()'ing them to an unused buffer. This probably worked originally, but since commit 46036188ea1f ("selftests/mm: build with -O2") the compiler is free to optimise away that unused buffer and the memcpy() with it. As a result there might not be any resident page in the mapping and the test may fail. We don't need to copy all that memory anyway. Just fault in every page. Cc: Usama Anjum Signed-off-by: Kevin Brodsky Acked-by: David Hildenbrand (Red Hat) Reviewed-by: Dev Jain --- tools/testing/selftests/mm/pagemap_ioctl.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/tools/testing/selftests/mm/pagemap_ioctl.c b/tools/testing/sel= ftests/mm/pagemap_ioctl.c index 2cb5441f29c7..80d7c391f8f5 100644 --- a/tools/testing/selftests/mm/pagemap_ioctl.c +++ b/tools/testing/selftests/mm/pagemap_ioctl.c @@ -1056,7 +1056,6 @@ int sanity_tests(void) struct page_region *vec; char *mem, *fmem; struct stat sbuf; - char *tmp_buf; =20 /* 1. wrong operation */ mem_size =3D 10 * page_size; @@ -1167,8 +1166,7 @@ int sanity_tests(void) if (fmem =3D=3D MAP_FAILED) ksft_exit_fail_msg("error nomem %d %s\n", errno, strerror(errno)); =20 - tmp_buf =3D malloc(sbuf.st_size); - memcpy(tmp_buf, fmem, sbuf.st_size); + force_read_pages_in_range(fmem, sbuf.st_size); =20 ret =3D pagemap_ioctl(fmem, sbuf.st_size, vec, vec_size, 0, 0, 0, PAGEMAP_NON_WRITTEN_BITS, 0, PAGEMAP_NON_WRITTEN_BITS); --=20 2.51.2