From patchwork Mon Mar 14 18:20:03 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Ramalingam C X-Patchwork-Id: 12780654 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 6DF76C433F5 for ; Mon, 14 Mar 2022 18:19:48 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id E4C9110E268; Mon, 14 Mar 2022 18:19:42 +0000 (UTC) Received: from mga18.intel.com (mga18.intel.com [134.134.136.126]) by gabe.freedesktop.org (Postfix) with ESMTPS id 4317310E291; Mon, 14 Mar 2022 18:19:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1647281981; x=1678817981; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=3FH32hwLfXGeT5vkIUdrknzTQFtlQVrfogh6IomWroA=; b=luuHArRwHV4lW4P9gYAGSqNSYRpZte1FZTiFo0yGIONJumcvKxZX+MB3 DWWs7rI0qpHevdnTXdCARovJnsloyvpymRJ+XNco7Ba7Y1FAO2OOYuuHS FwCw9yj0I8hYFCqGYFFHzMsDIhjp3O5La43VVICTXeBQABDVaza3TszV1 DOBdUEte/req2r+o5FZ99UO+UJiKcBWTBDH0OLuX+fLhH3NRVWxy1HJp8 5cehSXMJW2FI84SajzxxzYQgqY2AXNdXt7hWSiTAQkzcGdAbNxpr4JW2y 5CcO5Cl+fO1d8w0ZHb1BsGXH17zBLCM1MX+Pw8Z6C/Hxt4dCPQcCLbcRW w==; X-IronPort-AV: E=McAfee;i="6200,9189,10286"; a="238279122" X-IronPort-AV: E=Sophos;i="5.90,181,1643702400"; d="scan'208";a="238279122" 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 11:19:41 -0700 X-IronPort-AV: E=Sophos;i="5.90,181,1643702400"; d="scan'208";a="515549313" 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 11:19:38 -0700 From: Ramalingam C To: intel-gfx , dri-devel Subject: [PATCH 2/4] drm/i915/selftests: Check for incomplete LRI from the context image Date: Mon, 14 Mar 2022 23:50:03 +0530 Message-Id: <20220314182005.17071-3-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: Hellstrom Thomas , Daniele Ceraolo Spurio , Chris Wilson Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" From: Chris Wilson In order to keep the context image parser simple, we assume that all commands follow a similar format. A few, especially not MI commands on the render engines, have fixed lengths not encoded in a length field. This caused us to incorrectly skip over 3D state commands, and start interpretting context data as instructions. Eventually, as Daniele discovered, this would lead us to find addition LRI as part of the data and mistakenly add invalid LRI commands to the context probes. Stop parsing after we see the first !MI command, as we know we will have seen all the context registers by that point. (Mostly true for all gen so far, though the render context does have LRI after the first page that we have been ignoring so far. It would be useful to extract those as well so that we have the full list of user accesisble registers.) Similarly, emit a warning if we do try to emit an invalid zero-length LRI. Reported-by: Daniele Ceraolo Spurio Signed-off-by: Chris Wilson Cc: Daniele Ceraolo Spurio Signed-off-by: Ramalingam C Acked-by: Thomas Hellström --- drivers/gpu/drm/i915/gt/selftest_lrc.c | 61 +++++++++++++++++++++++--- 1 file changed, 54 insertions(+), 7 deletions(-) diff --git a/drivers/gpu/drm/i915/gt/selftest_lrc.c b/drivers/gpu/drm/i915/gt/selftest_lrc.c index 13f57c7c4224..0a8ed4246082 100644 --- a/drivers/gpu/drm/i915/gt/selftest_lrc.c +++ b/drivers/gpu/drm/i915/gt/selftest_lrc.c @@ -27,6 +27,9 @@ #define NUM_GPR 16 #define NUM_GPR_DW (NUM_GPR * 2) /* each GPR is 2 dwords */ +#define LRI_HEADER MI_INSTR(0x22, 0) +#define LRI_LENGTH_MASK GENMASK(7, 0) + static struct i915_vma *create_scratch(struct intel_gt *gt) { return __vm_create_scratch_for_read_pinned(>->ggtt->vm, PAGE_SIZE); @@ -180,7 +183,7 @@ static int live_lrc_layout(void *arg) continue; } - if ((lri & GENMASK(31, 23)) != MI_INSTR(0x22, 0)) { + if ((lri & GENMASK(31, 23)) != LRI_HEADER) { pr_err("%s: Expected LRI command at dword %d, found %08x\n", engine->name, dw, lri); err = -EINVAL; @@ -945,18 +948,40 @@ store_context(struct intel_context *ce, struct i915_vma *scratch) hw = defaults; hw += LRC_STATE_OFFSET / sizeof(*hw); do { - u32 len = hw[dw] & 0x7f; + u32 len = hw[dw] & LRI_LENGTH_MASK; + + /* + * Keep it simple, skip parsing complex commands + * + * At present, there are no more MI_LOAD_REGISTER_IMM + * commands after the first 3D state command. Rather + * than include a table (see i915_cmd_parser.c) of all + * the possible commands and their instruction lengths + * (or mask for variable length instructions), assume + * we have gathered the complete list of registers and + * bail out. + */ + if ((hw[dw] >> INSTR_CLIENT_SHIFT) != INSTR_MI_CLIENT) + break; if (hw[dw] == 0) { dw++; continue; } - if ((hw[dw] & GENMASK(31, 23)) != MI_INSTR(0x22, 0)) { + if ((hw[dw] & GENMASK(31, 23)) != LRI_HEADER) { + /* Assume all other MI commands match LRI length mask */ dw += len + 2; continue; } + if (!len) { + pr_err("%s: invalid LRI found in context image\n", + ce->engine->name); + igt_hexdump(defaults, PAGE_SIZE); + break; + } + dw++; len = (len + 1) / 2; while (len--) { @@ -1108,18 +1133,29 @@ static struct i915_vma *load_context(struct intel_context *ce, u32 poison) hw = defaults; hw += LRC_STATE_OFFSET / sizeof(*hw); do { - u32 len = hw[dw] & 0x7f; + u32 len = hw[dw] & LRI_LENGTH_MASK; + + /* For simplicity, break parsing at the first complex command */ + if ((hw[dw] >> INSTR_CLIENT_SHIFT) != INSTR_MI_CLIENT) + break; if (hw[dw] == 0) { dw++; continue; } - if ((hw[dw] & GENMASK(31, 23)) != MI_INSTR(0x22, 0)) { + if ((hw[dw] & GENMASK(31, 23)) != LRI_HEADER) { dw += len + 2; continue; } + if (!len) { + pr_err("%s: invalid LRI found in context image\n", + ce->engine->name); + igt_hexdump(defaults, PAGE_SIZE); + break; + } + dw++; len = (len + 1) / 2; *cs++ = MI_LOAD_REGISTER_IMM(len); @@ -1248,18 +1284,29 @@ static int compare_isolation(struct intel_engine_cs *engine, hw = defaults; hw += LRC_STATE_OFFSET / sizeof(*hw); do { - u32 len = hw[dw] & 0x7f; + u32 len = hw[dw] & LRI_LENGTH_MASK; + + /* For simplicity, break parsing at the first complex command */ + if ((hw[dw] >> INSTR_CLIENT_SHIFT) != INSTR_MI_CLIENT) + break; if (hw[dw] == 0) { dw++; continue; } - if ((hw[dw] & GENMASK(31, 23)) != MI_INSTR(0x22, 0)) { + if ((hw[dw] & GENMASK(31, 23)) != LRI_HEADER) { dw += len + 2; continue; } + if (!len) { + pr_err("%s: invalid LRI found in context image\n", + engine->name); + igt_hexdump(defaults, PAGE_SIZE); + break; + } + dw++; len = (len + 1) / 2; while (len--) {