From patchwork Wed Nov 27 17:35:28 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Maciej Wieczor-Retman X-Patchwork-Id: 13887256 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.9]) (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 60D9182D66; Wed, 27 Nov 2024 17:35:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.9 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732728959; cv=none; b=Tck4m4OUgKAmnVXRvHH/18CtBm8UJnLujLmFGszE+E+6u9XQCBrOnhnJWqrSQIrj9BCtoZf5lLm5I59ev3F5P17GUuJGj0HW7dB2qPH1Zyg0dvKb610p0MqDTlFhTQxAPbn+giVbIz/qJKU/xEcxpTzV6ylxnmipvxnrDIskVFI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732728959; c=relaxed/simple; bh=c0zuWt6mdYDjYYy4T74tvlWPLSfnhUIlLQoMx0yS/PY=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=V1WajU17UEPOE4d3lhecWHdgs2ihpHfF9qsh54V3Rigirb/pKCoDgWYoxWPa8DCEDY0D6w/ySVj3oqfvfHVqt1voxLiTugdapBxkCLkmoxcPmjZVea+YrY3CeOzdhz16oG+CdgbOLE/rDUE5RcnULU0drMyxWQwMyskvl2Y2qYs= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=Nb2bf6Mp; arc=none smtp.client-ip=192.198.163.9 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="Nb2bf6Mp" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1732728958; x=1764264958; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=c0zuWt6mdYDjYYy4T74tvlWPLSfnhUIlLQoMx0yS/PY=; b=Nb2bf6Mp+iIuTvrSSMxlLWBQL5iYLOa+nZilnl922jnMbuZIPf9aCvcJ 3IqBBQ2Rm8MAGatbI2+FM6+TW4VSOvjx2DtdTTQU6McdcS+uCSEA+U7Lu vMc/CAxA7Yu8weMn4cTZ09EZQya45mpy6Fe3RPylBpC9908ak8eZ7uI/I se2HPbr06FU86IJ5jbOAoY6/9+m9/rPfz7mNVctRaFANrGhPRBis0oCk7 21BWbFQu17dCi2DnO6ECyVxf/mgAp+hLek3R7b0NdMsW65fTzGiJVusgz NeazTuLBheeju7Wor2XQ2EF3eBs2oZs9UMps/S4gk9iGbsvWNQ3wGNWB0 w==; X-CSE-ConnectionGUID: R51cXALtQG+zT3gOYKGHlw== X-CSE-MsgGUID: +Z1IE9njQiGYFOzQFnhSKw== X-IronPort-AV: E=McAfee;i="6700,10204,11269"; a="43607485" X-IronPort-AV: E=Sophos;i="6.12,189,1728975600"; d="scan'208";a="43607485" Received: from fmviesa006.fm.intel.com ([10.60.135.146]) by fmvoesa103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 27 Nov 2024 09:35:57 -0800 X-CSE-ConnectionGUID: xnuEqC3CSOi221KXmmb9MQ== X-CSE-MsgGUID: RgpV8uTaS++Kwab9OnAHCQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.12,189,1728975600"; d="scan'208";a="91626318" Received: from pgcooper-mobl3.ger.corp.intel.com (HELO wieczorr-mobl1.intel.com) ([10.245.244.193]) by fmviesa006-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 27 Nov 2024 09:35:54 -0800 From: Maciej Wieczor-Retman To: shuah@kernel.org, hpa@zytor.com, x86@kernel.org, dave.hansen@linux.intel.com, bp@alien8.de, mingo@redhat.com, tglx@linutronix.de Cc: linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, kirill@shutemov.name, maciej.wieczor-retman@intel.com Subject: [PATCH v5 0/3] selftests/lam: get_user additions and LAM enabled check Date: Wed, 27 Nov 2024 18:35:28 +0100 Message-ID: X-Mailer: git-send-email 2.47.1 Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Recent change in how get_user() handles pointers [1] has a specific case for LAM. It assigns a different bitmask that's later used to check whether a pointer comes from userland in get_user(). While currently commented out (until LASS [2] is merged into the kernel) it's worth making changes to the LAM selftest ahead of time. Modify cpu_has_la57() so it provides current paging level information instead of the cpuid one. Add test case to LAM that utilizes a ioctl (FIOASYNC) syscall which uses get_user() in its implementation. Execute the syscall with differently tagged pointers to verify that valid user pointers are passing through and invalid kernel/non-canonical pointers are not. Also to avoid unhelpful test failures add a check in main() to skip running tests if LAM was not compiled into the kernel. Code was tested on a Sierra Forest Xeon machine that's LAM capable. The test was ran without issues with both the LAM lines from [1] untouched and commented out. The test was also ran without issues with LAM_SUP both enabled and disabled. 4/5 level pagetables code paths were also successfully tested in Simics on a 5-level capable machine. [1] https://lore.kernel.org/all/20241024013214.129639-1-torvalds@linux-foundation.org/ [2] https://lore.kernel.org/all/20241028160917.1380714-1-alexander.shishkin@linux.intel.com/ Maciej Wieczor-Retman (3): selftests/lam: Move cpu_has_la57() to use cpuinfo flag selftests/lam: Skip test if LAM is disabled selftests/lam: Test get_user() LAM pointer handling tools/testing/selftests/x86/lam.c | 120 ++++++++++++++++++++++++++++-- 1 file changed, 115 insertions(+), 5 deletions(-)