From patchwork Fri Nov 10 17:44:24 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Adam Wallis X-Patchwork-Id: 10053507 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 15F65603FA for ; Fri, 10 Nov 2017 17:44:52 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id EEE802B3B7 for ; Fri, 10 Nov 2017 17:44:51 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id E2C592B393; Fri, 10 Nov 2017 17:44:51 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_HI,T_DKIM_INVALID autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 54D2D2B393 for ; Fri, 10 Nov 2017 17:44:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752685AbdKJRou (ORCPT ); Fri, 10 Nov 2017 12:44:50 -0500 Received: from smtp.codeaurora.org ([198.145.29.96]:46222 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752625AbdKJRot (ORCPT ); Fri, 10 Nov 2017 12:44:49 -0500 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id ED147607E5; Fri, 10 Nov 2017 17:44:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1510335888; bh=gfacPBAeiACpJXXPsio0M6HA7aB43avbHuwRAJ+Npds=; h=From:To:Cc:Subject:Date:From; b=X0mBUr57zQZWlihsmgqSgoKd4BWoQAhJ4l7iEetPkPfK4tpqKSTyLXWopyL/0GWE+ U0NWgZP+ryvjN9v8iL6FfQNSV6bLonpB9CGBhI6bT2vD6F8Fs5pjRqjM40JUsompTB ksz82XRoErIC2yYdxROHJfPv8jeMNnodXShuyX90= Received: from chromaggus.qualcomm.com (global_nat1_iad_fw.qualcomm.com [129.46.232.65]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: awallis@smtp.codeaurora.org) by smtp.codeaurora.org (Postfix) with ESMTPSA id 7703B607A1; Fri, 10 Nov 2017 17:44:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1510335883; bh=gfacPBAeiACpJXXPsio0M6HA7aB43avbHuwRAJ+Npds=; h=From:To:Cc:Subject:Date:From; b=Mh8JgowmR6ne8Cayz/0jfXD4yhWDuoR9kTov773XuSXAYTVZhGSQa9DRp8i8sLym6 vGM3wAtbzKlZOPFn9A/VdeZNogJRIWuFME6V1Mqa+zRp9Vto+3IRmLZ7r6cg1TaoWT rLRYs3joSgzLj3bKfNbhIP/QJCVEAMdb/v5CpOmk= DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 7703B607A1 Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=none smtp.mailfrom=awallis@codeaurora.org From: Adam Wallis To: linux-arm-kernel@lists.infradead.org, Vinod Koul , Dan Williams , Sinan Kaya , dmaengine@vger.kernel.org, shunyong.yang@hxt-semitech.com, rruigrok@codeaurora.org Cc: timur@codeaurora.org Subject: [PATCH] dmaengine: dmatest: move callback wait queue to thread context Date: Fri, 10 Nov 2017 12:44:24 -0500 Message-Id: <1510335864-25997-1-git-send-email-awallis@codeaurora.org> X-Mailer: git-send-email 1.9.1 Sender: dmaengine-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: dmaengine@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Commit adfa543e7314 ("dmatest: don't use set_freezable_with_signal()") introduced a bug (that is in fact documented by the patch commit text) that leaves behind a dangling pointer. Since the done_wait structure is allocated on the stack, future invocations to the DMATEST can produce undesirable results (e.g., corrupted spinlocks). Commit a9df21e34b42 ("dmaengine: dmatest: warn user when dma test times out") attempted to WARN the user that the stack was likely corrupted but did not fix the actual issue. This patch fixes the issue by pushing the wait queue and callback structs into the the thread structure. If a failure occurs due to time, dmaengine_terminate_all will force the callback to safely call wake_up_all() without possibility of using a freed pointer. Cc: stable@vger.kernel.org Bug: https://bugzilla.kernel.org/show_bug.cgi?id=197605 Reviewed-by: Sinan Kaya Suggested-by: Shunyong Yang Signed-off-by: Adam Wallis --- drivers/dma/dmatest.c | 37 ++++++++++++++++--------------------- 1 file changed, 16 insertions(+), 21 deletions(-) diff --git a/drivers/dma/dmatest.c b/drivers/dma/dmatest.c index 47edc7f..2573b6c 100644 --- a/drivers/dma/dmatest.c +++ b/drivers/dma/dmatest.c @@ -155,6 +155,12 @@ struct dmatest_params { #define PATTERN_COUNT_MASK 0x1f #define PATTERN_MEMSET_IDX 0x01 +/* poor man's completion - we want to use wait_event_freezable() on it */ +struct dmatest_done { + bool done; + wait_queue_head_t *wait; +}; + struct dmatest_thread { struct list_head node; struct dmatest_info *info; @@ -165,6 +171,8 @@ struct dmatest_thread { u8 **dsts; u8 **udsts; enum dma_transaction_type type; + wait_queue_head_t done_wait; + struct dmatest_done test_done; bool done; }; @@ -342,11 +350,6 @@ static unsigned int dmatest_verify(u8 **bufs, unsigned int start, return error_count; } -/* poor man's completion - we want to use wait_event_freezable() on it */ -struct dmatest_done { - bool done; - wait_queue_head_t *wait; -}; static void dmatest_callback(void *arg) { @@ -424,9 +427,8 @@ static unsigned long long dmatest_KBs(s64 runtime, unsigned long long len) */ static int dmatest_func(void *data) { - DECLARE_WAIT_QUEUE_HEAD_ONSTACK(done_wait); struct dmatest_thread *thread = data; - struct dmatest_done done = { .wait = &done_wait }; + struct dmatest_done *done = &thread->test_done; struct dmatest_info *info; struct dmatest_params *params; struct dma_chan *chan; @@ -673,9 +675,9 @@ static int dmatest_func(void *data) continue; } - done.done = false; + done->done = false; tx->callback = dmatest_callback; - tx->callback_param = &done; + tx->callback_param = done; cookie = tx->tx_submit(tx); if (dma_submit_error(cookie)) { @@ -688,21 +690,12 @@ static int dmatest_func(void *data) } dma_async_issue_pending(chan); - wait_event_freezable_timeout(done_wait, done.done, + wait_event_freezable_timeout(thread->done_wait, done->done, msecs_to_jiffies(params->timeout)); status = dma_async_is_tx_complete(chan, cookie, NULL, NULL); - if (!done.done) { - /* - * We're leaving the timed out dma operation with - * dangling pointer to done_wait. To make this - * correct, we'll need to allocate wait_done for - * each test iteration and perform "who's gonna - * free it this time?" dancing. For now, just - * leave it dangling. - */ - WARN(1, "dmatest: Kernel stack may be corrupted!!\n"); + if (!done->done) { dmaengine_unmap_put(um); result("test timed out", total_tests, src_off, dst_off, len, 0); @@ -789,7 +782,7 @@ static int dmatest_func(void *data) dmatest_KBs(runtime, total_len), ret); /* terminate all transfers on specified channels */ - if (ret) + if (ret || failed_tests) dmaengine_terminate_all(chan); thread->done = true; @@ -849,6 +842,8 @@ static int dmatest_add_threads(struct dmatest_info *info, thread->info = info; thread->chan = dtc->chan; thread->type = type; + thread->test_done.wait = &thread->done_wait; + init_waitqueue_head(&thread->done_wait); smp_wmb(); thread->task = kthread_create(dmatest_func, thread, "%s-%s%u", dma_chan_name(chan), op, i);