From patchwork Mon Mar 14 18:20:04 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ramalingam C X-Patchwork-Id: 12780655 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 03491C433FE for ; Mon, 14 Mar 2022 18:19:52 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id D73C710E360; Mon, 14 Mar 2022 18:19:47 +0000 (UTC) Received: from mga18.intel.com (mga18.intel.com [134.134.136.126]) by gabe.freedesktop.org (Postfix) with ESMTPS id A378F10E2E8; Mon, 14 Mar 2022 18:19:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1647281983; x=1678817983; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=z0Hn3QhqbH4SGwzFRjVD3ddzXZUuVyn1XMZMas1ZDbI=; b=I3Mna8j96yZpkgIcDsdr9LO+d5eioNLFl1+PcK7Xt7lvl2m9Vu7+aMXN geZAlxjK0m/9PSSyX6u68l8KRbtfSJHVyTTA5LMPtoktmooMxsyf1jmrB jm33HdMhUdZuAuCBDbqmIAQfcy5tob7CBPJLtxpb1BalPAFj3txCE2pHK qkGPueDzeq0H+MTaJSDyhsf53ZMgJWKrYEz3HNLEddubyLSXSiHDbbJQs 6esWOUV8KXdWOSA0ROuGFvBzNk9B1HQLiZjzenEL/MiqtPWaersfBSOxc W1X8hry0GAa2YFiAYX5fB8zu8G1mtoB4sjiU6ufXEhTYL3oV26OtnORQf w==; X-IronPort-AV: E=McAfee;i="6200,9189,10286"; a="238279140" X-IronPort-AV: E=Sophos;i="5.90,181,1643702400"; d="scan'208";a="238279140" Received: from orsmga006.jf.intel.com ([10.7.209.51]) by orsmga106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Mar 2022 11:19:43 -0700 X-IronPort-AV: E=Sophos;i="5.90,181,1643702400"; d="scan'208";a="515549352" Received: from ramaling-i9x.iind.intel.com ([10.203.144.108]) by orsmga006-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Mar 2022 11:19:41 -0700 From: Ramalingam C To: intel-gfx , dri-devel Subject: [PATCH 3/4] drm/i915/selftest: Clear the output buffers before GPU writes Date: Mon, 14 Mar 2022 23:50:04 +0530 Message-Id: <20220314182005.17071-4-ramalingam.c@intel.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20220314182005.17071-1-ramalingam.c@intel.com> References: <20220314182005.17071-1-ramalingam.c@intel.com> MIME-Version: 1.0 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: CQ Tang , Hellstrom Thomas , Chris Wilson Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" From: Chris Wilson When testing whether we can get the GPU to leak information about non-privileged state, we first need to ensure that the output buffer is set to a known value as the HW may opt to skip the write into memory for a non-privileged read of a sensitive register. We chose POISON_INUSE (0x5a) so that is both non-zero and distinct from the poison values used during the test. Reported-by: CQ Tang Signed-off-by: Chris Wilson Cc: CQ Tang cc: Joonas Lahtinen Signed-off-by: Ramalingam C --- drivers/gpu/drm/i915/gt/selftest_lrc.c | 32 ++++++++++++++++++++++---- 1 file changed, 28 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/i915/gt/selftest_lrc.c b/drivers/gpu/drm/i915/gt/selftest_lrc.c index 0a8ed4246082..b9cc89de01bf 100644 --- a/drivers/gpu/drm/i915/gt/selftest_lrc.c +++ b/drivers/gpu/drm/i915/gt/selftest_lrc.c @@ -1346,6 +1346,30 @@ static int compare_isolation(struct intel_engine_cs *engine, return err; } +static struct i915_vma * +create_result_vma(struct i915_address_space *vm, unsigned long sz) +{ + struct i915_vma *vma; + void *ptr; + + vma = create_user_vma(vm, sz); + if (IS_ERR(vma)) + return vma; + + /* Set the results to a known value distinct from the poison */ + ptr = i915_gem_object_pin_map(vma->obj, I915_MAP_WC); + if (IS_ERR(ptr)) { + i915_vma_put(vma); + return ERR_CAST(ptr); + } + + memset(ptr, POISON_INUSE, vma->size); + i915_gem_object_flush_map(vma->obj); + i915_gem_object_unpin_map(vma->obj); + + return vma; +} + static int __lrc_isolation(struct intel_engine_cs *engine, u32 poison) { u32 *sema = memset32(engine->status_page.addr + 1000, 0, 1); @@ -1364,13 +1388,13 @@ static int __lrc_isolation(struct intel_engine_cs *engine, u32 poison) goto err_A; } - ref[0] = create_user_vma(A->vm, SZ_64K); + ref[0] = create_result_vma(A->vm, SZ_64K); if (IS_ERR(ref[0])) { err = PTR_ERR(ref[0]); goto err_B; } - ref[1] = create_user_vma(A->vm, SZ_64K); + ref[1] = create_result_vma(A->vm, SZ_64K); if (IS_ERR(ref[1])) { err = PTR_ERR(ref[1]); goto err_ref0; @@ -1392,13 +1416,13 @@ static int __lrc_isolation(struct intel_engine_cs *engine, u32 poison) } i915_request_put(rq); - result[0] = create_user_vma(A->vm, SZ_64K); + result[0] = create_result_vma(A->vm, SZ_64K); if (IS_ERR(result[0])) { err = PTR_ERR(result[0]); goto err_ref1; } - result[1] = create_user_vma(A->vm, SZ_64K); + result[1] = create_result_vma(A->vm, SZ_64K); if (IS_ERR(result[1])) { err = PTR_ERR(result[1]); goto err_result0;