From patchwork Thu Sep 24 06:59:44 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mansur Alisha Shaik X-Patchwork-Id: 11796393 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 30D0292C for ; Thu, 24 Sep 2020 07:00:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 197C62395C for ; Thu, 24 Sep 2020 07:00:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727034AbgIXHAL (ORCPT ); Thu, 24 Sep 2020 03:00:11 -0400 Received: from alexa-out.qualcomm.com ([129.46.98.28]:46639 "EHLO alexa-out.qualcomm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726961AbgIXHAL (ORCPT ); Thu, 24 Sep 2020 03:00:11 -0400 Received: from ironmsg08-lv.qualcomm.com ([10.47.202.152]) by alexa-out.qualcomm.com with ESMTP; 23 Sep 2020 23:59:55 -0700 Received: from ironmsg02-blr.qualcomm.com ([10.86.208.131]) by ironmsg08-lv.qualcomm.com with ESMTP/TLS/AES256-SHA; 23 Sep 2020 23:59:53 -0700 Received: from c-mansur-linux.qualcomm.com ([10.204.90.208]) by ironmsg02-blr.qualcomm.com with ESMTP; 24 Sep 2020 12:29:51 +0530 Received: by c-mansur-linux.qualcomm.com (Postfix, from userid 461723) id 5208C21D59; Thu, 24 Sep 2020 12:29:50 +0530 (IST) From: Mansur Alisha Shaik To: linux-media@vger.kernel.org, stanimir.varbanov@linaro.org Cc: linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, vgarodia@codeaurora.org, Mansur Alisha Shaik Subject: [PATCH v5 1/3] venus: core: handle race condititon for core ops Date: Thu, 24 Sep 2020 12:29:44 +0530 Message-Id: <1600930786-18275-2-git-send-email-mansur@codeaurora.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1600930786-18275-1-git-send-email-mansur@codeaurora.org> References: <1600930786-18275-1-git-send-email-mansur@codeaurora.org> Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org For core ops we are having only write protect but there is no read protect, because of this in multithreading and concurrency, one CPU core is reading without wait which is causing the NULL pointer dereferece crash. one such scenario is as show below, where in one CPU core, core->ops becoming NULL and in another CPU core calling core->ops->session_init(). CPU: core-7: Call trace: hfi_session_init+0x180/0x1dc [venus_core] vdec_queue_setup+0x9c/0x364 [venus_dec] vb2_core_reqbufs+0x1e4/0x368 [videobuf2_common] vb2_reqbufs+0x4c/0x64 [videobuf2_v4l2] v4l2_m2m_reqbufs+0x50/0x84 [v4l2_mem2mem] v4l2_m2m_ioctl_reqbufs+0x2c/0x38 [v4l2_mem2mem] v4l_reqbufs+0x4c/0x5c __video_do_ioctl+0x2b0/0x39c CPU: core-0: Call trace: venus_shutdown+0x98/0xfc [venus_core] venus_sys_error_handler+0x64/0x148 [venus_core] process_one_work+0x210/0x3d0 worker_thread+0x248/0x3f4 kthread+0x11c/0x12c Signed-off-by: Mansur Alisha Shaik Acked-by: Stanimir Varbanov --- Changes in v5: - Addressed review comments by stan in v4 version drivers/media/platform/qcom/venus/hfi.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/drivers/media/platform/qcom/venus/hfi.c b/drivers/media/platform/qcom/venus/hfi.c index a59022a..638ed5c 100644 --- a/drivers/media/platform/qcom/venus/hfi.c +++ b/drivers/media/platform/qcom/venus/hfi.c @@ -198,6 +198,18 @@ int hfi_session_init(struct venus_inst *inst, u32 pixfmt) const struct hfi_ops *ops = core->ops; int ret; + /* + * If core shutdown is in progress or if we are in system + * recovery, return an error as during system error recovery + * session_init() can't pass successfully + */ + mutex_lock(&core->lock); + if (!core->ops || core->sys_error) { + mutex_unlock(&core->lock); + return -EIO; + } + mutex_unlock(&core->lock); + if (inst->state != INST_UNINIT) return -EINVAL;