From patchwork Mon Aug 17 15:10:57 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 266525 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-12.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B6EEEC433DF for ; Mon, 17 Aug 2020 15:23:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 96F6723382 for ; Mon, 17 Aug 2020 15:23:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597677793; bh=WlMHZGrHsTRRURnOEQgp8HWwE6YoZ6gLYbRbIFTqfN8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=pMvo0kIbFTiob8GTFkJbI4JhEfCBWWdrCcFVV4JRgpvYh2aoELzQk593+kUG1dRIO nVId4XHsukiG68CPqOP3mVgAs1kVEVFOP7krsNilNAvcL9wWn8GkiNzg/oqlpfLBUF wa5Yi/Y+vSyo5NiGVh/61LV75EYLMRvAuZvPPDHQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729513AbgHQPXF (ORCPT ); Mon, 17 Aug 2020 11:23:05 -0400 Received: from mail.kernel.org ([198.145.29.99]:48802 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729496AbgHQPW4 (ORCPT ); Mon, 17 Aug 2020 11:22:56 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 44FC82310F; Mon, 17 Aug 2020 15:22:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597677775; bh=WlMHZGrHsTRRURnOEQgp8HWwE6YoZ6gLYbRbIFTqfN8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=uXiycR/LBzT5AdW70YHmLAaClRB60QkbIpKF8sx7fxUVGoLn34BMi/UCQZT7GD2GK jynPQZc8mma0O1VVVSBWtfdTv4b4cfo8fS9zx4xsJdVTJKqdNRgmImRoPi8yNHZNCO tAsyqzbf6X6svrCxV0hPGjMQFixQUn4Atz4S6Pzs= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Akhil P Oommen , Rob Clark , Sasha Levin Subject: [PATCH 5.8 104/464] drm/msm: Fix a null pointer access in msm_gem_shrinker_count() Date: Mon, 17 Aug 2020 17:10:57 +0200 Message-Id: <20200817143838.775395515@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200817143833.737102804@linuxfoundation.org> References: <20200817143833.737102804@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Akhil P Oommen [ Upstream commit 3cbdc8d8b7f39a7af3ea7b8dfa75caaebfda4e56 ] Adding an msm_gem_object object to the inactive_list before completing its initialization is a bad idea because shrinker may pick it up from the inactive_list. Fix this by making sure that the initialization is complete before moving the msm_obj object to the inactive list. This patch fixes the below error: [10027.553044] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000068 [10027.573305] Mem abort info: [10027.590160] ESR = 0x96000006 [10027.597905] EC = 0x25: DABT (current EL), IL = 32 bits [10027.614430] SET = 0, FnV = 0 [10027.624427] EA = 0, S1PTW = 0 [10027.632722] Data abort info: [10027.638039] ISV = 0, ISS = 0x00000006 [10027.647459] CM = 0, WnR = 0 [10027.654345] user pgtable: 4k pages, 39-bit VAs, pgdp=00000001e3a6a000 [10027.672681] [0000000000000068] pgd=0000000198c31003, pud=0000000198c31003, pmd=0000000000000000 [10027.693900] Internal error: Oops: 96000006 [#1] PREEMPT SMP [10027.738261] CPU: 3 PID: 214 Comm: kswapd0 Tainted: G S 5.4.40 #1 [10027.745766] Hardware name: Qualcomm Technologies, Inc. SC7180 IDP (DT) [10027.752472] pstate: 80c00009 (Nzcv daif +PAN +UAO) [10027.757409] pc : mutex_is_locked+0x14/0x2c [10027.761626] lr : msm_gem_shrinker_count+0x70/0xec [10027.766454] sp : ffffffc011323ad0 [10027.769867] x29: ffffffc011323ad0 x28: ffffffe677e4b878 [10027.775324] x27: 0000000000000cc0 x26: 0000000000000000 [10027.780783] x25: ffffff817114a708 x24: 0000000000000008 [10027.786242] x23: ffffff8023ab7170 x22: 0000000000000001 [10027.791701] x21: ffffff817114a080 x20: 0000000000000119 [10027.797160] x19: 0000000000000068 x18: 00000000000003bc [10027.802621] x17: 0000000004a34210 x16: 00000000000000c0 [10027.808083] x15: 0000000000000000 x14: 0000000000000000 [10027.813542] x13: ffffffe677e0a3c0 x12: 0000000000000000 [10027.819000] x11: 0000000000000000 x10: ffffff8174b94340 [10027.824461] x9 : 0000000000000000 x8 : 0000000000000000 [10027.829919] x7 : 00000000000001fc x6 : ffffffc011323c88 [10027.835373] x5 : 0000000000000001 x4 : ffffffc011323d80 [10027.840832] x3 : ffffffff0477b348 x2 : 0000000000000000 [10027.846290] x1 : ffffffc011323b68 x0 : 0000000000000068 [10027.851748] Call trace: [10027.854264] mutex_is_locked+0x14/0x2c [10027.858121] msm_gem_shrinker_count+0x70/0xec [10027.862603] shrink_slab+0xc0/0x4b4 [10027.866187] shrink_node+0x4a8/0x818 [10027.869860] kswapd+0x624/0x890 [10027.873097] kthread+0x11c/0x12c [10027.876424] ret_from_fork+0x10/0x18 [10027.880102] Code: f9000bf3 910003fd aa0003f3 d503201f (f9400268) [10027.886362] ---[ end trace df5849a1a3543251 ]--- [10027.891518] Kernel panic - not syncing: Fatal exception Signed-off-by: Akhil P Oommen Signed-off-by: Rob Clark Signed-off-by: Sasha Levin --- drivers/gpu/drm/msm/msm_gem.c | 36 ++++++++++++++++++++--------------- 1 file changed, 21 insertions(+), 15 deletions(-) diff --git a/drivers/gpu/drm/msm/msm_gem.c b/drivers/gpu/drm/msm/msm_gem.c index 6277fde13df91..f63bb7e452d2a 100644 --- a/drivers/gpu/drm/msm/msm_gem.c +++ b/drivers/gpu/drm/msm/msm_gem.c @@ -994,10 +994,8 @@ int msm_gem_new_handle(struct drm_device *dev, struct drm_file *file, static int msm_gem_new_impl(struct drm_device *dev, uint32_t size, uint32_t flags, - struct drm_gem_object **obj, - bool struct_mutex_locked) + struct drm_gem_object **obj) { - struct msm_drm_private *priv = dev->dev_private; struct msm_gem_object *msm_obj; switch (flags & MSM_BO_CACHE_MASK) { @@ -1023,15 +1021,6 @@ static int msm_gem_new_impl(struct drm_device *dev, INIT_LIST_HEAD(&msm_obj->submit_entry); INIT_LIST_HEAD(&msm_obj->vmas); - if (struct_mutex_locked) { - WARN_ON(!mutex_is_locked(&dev->struct_mutex)); - list_add_tail(&msm_obj->mm_list, &priv->inactive_list); - } else { - mutex_lock(&dev->struct_mutex); - list_add_tail(&msm_obj->mm_list, &priv->inactive_list); - mutex_unlock(&dev->struct_mutex); - } - *obj = &msm_obj->base; return 0; @@ -1041,6 +1030,7 @@ static struct drm_gem_object *_msm_gem_new(struct drm_device *dev, uint32_t size, uint32_t flags, bool struct_mutex_locked) { struct msm_drm_private *priv = dev->dev_private; + struct msm_gem_object *msm_obj; struct drm_gem_object *obj = NULL; bool use_vram = false; int ret; @@ -1061,14 +1051,15 @@ static struct drm_gem_object *_msm_gem_new(struct drm_device *dev, if (size == 0) return ERR_PTR(-EINVAL); - ret = msm_gem_new_impl(dev, size, flags, &obj, struct_mutex_locked); + ret = msm_gem_new_impl(dev, size, flags, &obj); if (ret) goto fail; + msm_obj = to_msm_bo(obj); + if (use_vram) { struct msm_gem_vma *vma; struct page **pages; - struct msm_gem_object *msm_obj = to_msm_bo(obj); mutex_lock(&msm_obj->lock); @@ -1103,6 +1094,15 @@ static struct drm_gem_object *_msm_gem_new(struct drm_device *dev, mapping_set_gfp_mask(obj->filp->f_mapping, GFP_HIGHUSER); } + if (struct_mutex_locked) { + WARN_ON(!mutex_is_locked(&dev->struct_mutex)); + list_add_tail(&msm_obj->mm_list, &priv->inactive_list); + } else { + mutex_lock(&dev->struct_mutex); + list_add_tail(&msm_obj->mm_list, &priv->inactive_list); + mutex_unlock(&dev->struct_mutex); + } + return obj; fail: @@ -1125,6 +1125,7 @@ struct drm_gem_object *msm_gem_new(struct drm_device *dev, struct drm_gem_object *msm_gem_import(struct drm_device *dev, struct dma_buf *dmabuf, struct sg_table *sgt) { + struct msm_drm_private *priv = dev->dev_private; struct msm_gem_object *msm_obj; struct drm_gem_object *obj; uint32_t size; @@ -1138,7 +1139,7 @@ struct drm_gem_object *msm_gem_import(struct drm_device *dev, size = PAGE_ALIGN(dmabuf->size); - ret = msm_gem_new_impl(dev, size, MSM_BO_WC, &obj, false); + ret = msm_gem_new_impl(dev, size, MSM_BO_WC, &obj); if (ret) goto fail; @@ -1163,6 +1164,11 @@ struct drm_gem_object *msm_gem_import(struct drm_device *dev, } mutex_unlock(&msm_obj->lock); + + mutex_lock(&dev->struct_mutex); + list_add_tail(&msm_obj->mm_list, &priv->inactive_list); + mutex_unlock(&dev->struct_mutex); + return obj; fail: