From patchwork Mon Dec 14 10:50:50 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jani Nikula X-Patchwork-Id: 7843401 Return-Path: X-Original-To: patchwork-intel-gfx@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 57C1BBEEE1 for ; Mon, 14 Dec 2015 10:51:16 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 5AC57203C3 for ; Mon, 14 Dec 2015 10:51:15 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) by mail.kernel.org (Postfix) with ESMTP id 53C5C203DB for ; Mon, 14 Dec 2015 10:51:14 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id D37FC6E601; Mon, 14 Dec 2015 02:51:13 -0800 (PST) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from mga03.intel.com (mga03.intel.com [134.134.136.65]) by gabe.freedesktop.org (Postfix) with ESMTP id 797076E603 for ; Mon, 14 Dec 2015 02:51:12 -0800 (PST) Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by orsmga103.jf.intel.com with ESMTP; 14 Dec 2015 02:51:12 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.20,426,1444719600"; d="scan'208";a="873139128" Received: from jnikula-mobl.fi.intel.com (HELO localhost) ([10.237.72.67]) by fmsmga002.fm.intel.com with ESMTP; 14 Dec 2015 02:51:10 -0800 From: Jani Nikula To: intel-gfx@lists.freedesktop.org Date: Mon, 14 Dec 2015 12:50:50 +0200 Message-Id: <068ea5809a2ebe1e79aef85bc91d05ef69041f1d.1450089383.git.jani.nikula@intel.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: References: In-Reply-To: References: Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo Cc: Deepak M , jani.nikula@intel.com Subject: [Intel-gfx] [PATCH 06/11] drm/i915: refactor VBT validation X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Make the validation function a boolean operating on a buffer of given size, removing the extra pointer dances. Move the OpRegion based VBT validation to intel_opregion_setup(), only initializing opregion->vbt if it's valid. Signed-off-by: Jani Nikula --- drivers/gpu/drm/i915/i915_drv.h | 1 + drivers/gpu/drm/i915/intel_bios.c | 63 ++++++++++++++++++----------------- drivers/gpu/drm/i915/intel_opregion.c | 9 +++-- 3 files changed, 40 insertions(+), 33 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index a2bd4c6a86a1..ef15f1710b50 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -3354,6 +3354,7 @@ extern void intel_i2c_reset(struct drm_device *dev); /* intel_bios.c */ int intel_bios_init(struct drm_device *dev); +bool intel_bios_is_valid_vbt(const void *buf, size_t size); /* intel_opregion.c */ #ifdef CONFIG_ACPI diff --git a/drivers/gpu/drm/i915/intel_bios.c b/drivers/gpu/drm/i915/intel_bios.c index f2b79b7d12b8..007b2b759600 100644 --- a/drivers/gpu/drm/i915/intel_bios.c +++ b/drivers/gpu/drm/i915/intel_bios.c @@ -1221,37 +1221,40 @@ static const struct bdb_header *get_bdb_header(const struct vbt_header *vbt) return _vbt + vbt->bdb_offset; } -static const struct vbt_header *validate_vbt(const void *base, - size_t size, - const void *_vbt) +/** + * intel_bios_is_valid_vbt - does the given buffer contain a valid VBT + * @buf: pointer to a buffer to validate + * @size: size of the buffer + * + * Returns true on valid VBT. + */ +bool intel_bios_is_valid_vbt(const void *buf, size_t size) { - size_t offset = _vbt - base; - const struct vbt_header *vbt = _vbt; + const struct vbt_header *vbt = buf; const struct bdb_header *bdb; if (!vbt) - return NULL; + return false; - if (offset + sizeof(struct vbt_header) > size) { + if (sizeof(struct vbt_header) > size) { DRM_DEBUG_DRIVER("VBT header incomplete\n"); - return NULL; + return false; } if (memcmp(vbt->signature, "$VBT", 4)) { DRM_DEBUG_DRIVER("VBT invalid signature\n"); - return NULL; + return false; } - offset += vbt->bdb_offset; - if (offset + sizeof(struct bdb_header) > size) { + if (vbt->bdb_offset + sizeof(struct bdb_header) > size) { DRM_DEBUG_DRIVER("BDB header incomplete\n"); - return NULL; + return false; } bdb = get_bdb_header(vbt); - if (offset + bdb->bdb_size > size) { + if (vbt->bdb_offset + bdb->bdb_size > size) { DRM_DEBUG_DRIVER("BDB incomplete\n"); - return NULL; + return false; } return vbt; @@ -1259,26 +1262,27 @@ static const struct vbt_header *validate_vbt(const void *base, static const struct vbt_header *find_vbt(void __iomem *bios, size_t size) { - const struct vbt_header *vbt = NULL; size_t i; /* Scour memory looking for the VBT signature. */ for (i = 0; i + 4 < size; i++) { - if (ioread32(bios + i) == *((const u32 *) "$VBT")) { - /* - * This is the one place where we explicitly discard the - * address space (__iomem) of the BIOS/VBT. From now on - * everything is based on 'base', and treated as regular - * memory. - */ - void *_bios = (void __force *) bios; + void *vbt; - vbt = validate_vbt(_bios, size, _bios + i); - break; - } + if (ioread32(bios + i) != *((const u32 *) "$VBT")) + continue; + + /* + * This is the one place where we explicitly discard the address + * space (__iomem) of the BIOS/VBT. + */ + vbt = (void __force *) bios + i; + if (intel_bios_is_valid_vbt(vbt, size - i)) + return vbt; + + break; } - return vbt; + return NULL; } /** @@ -1295,7 +1299,7 @@ intel_bios_init(struct drm_device *dev) { struct drm_i915_private *dev_priv = dev->dev_private; struct pci_dev *pdev = dev->pdev; - const struct vbt_header *vbt; + const struct vbt_header *vbt = dev_priv->opregion.vbt; const struct bdb_header *bdb; u8 __iomem *bios = NULL; @@ -1304,9 +1308,6 @@ intel_bios_init(struct drm_device *dev) init_vbt_defaults(dev_priv); - /* XXX Should this validation be moved to intel_opregion.c? */ - vbt = validate_vbt(dev_priv->opregion.header, OPREGION_SIZE, - dev_priv->opregion.vbt); if (vbt) { DRM_DEBUG_KMS("Using VBT from ACPI OpRegion: %20s\n", vbt->signature); diff --git a/drivers/gpu/drm/i915/intel_opregion.c b/drivers/gpu/drm/i915/intel_opregion.c index 5b9fc790d300..9f992e7c6185 100644 --- a/drivers/gpu/drm/i915/intel_opregion.c +++ b/drivers/gpu/drm/i915/intel_opregion.c @@ -986,8 +986,13 @@ int intel_opregion_setup(struct drm_device *dev) if (mboxes & MBOX_ASLE_EXT) DRM_DEBUG_DRIVER("ASLE extension supported\n"); - if (!dmi_check_system(intel_no_opregion_vbt)) - opregion->vbt = base + OPREGION_VBT_OFFSET; + if (!dmi_check_system(intel_no_opregion_vbt)) { + void *vbt = base + OPREGION_VBT_OFFSET; + u32 vbt_size = OPREGION_SIZE - OPREGION_VBT_OFFSET; + + if (intel_bios_is_valid_vbt(vbt, vbt_size)) + opregion->vbt = vbt; + } return 0;