Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754323AbdDKJKv (ORCPT ); Tue, 11 Apr 2017 05:10:51 -0400 Received: from mail-pg0-f49.google.com ([74.125.83.49]:33603 "EHLO mail-pg0-f49.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754177AbdDKJKq (ORCPT ); Tue, 11 Apr 2017 05:10:46 -0400 From: Leo Yan To: Mathieu Poirier , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Cc: Leo Yan , Mike Leach , Suzuki K Poulose Subject: [PATCH RFC 1/4] coresight: tmc: check dump buffer is overflow Date: Tue, 11 Apr 2017 17:10:26 +0800 Message-Id: <1491901829-18477-2-git-send-email-leo.yan@linaro.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1491901829-18477-1-git-send-email-leo.yan@linaro.org> References: <1491901829-18477-1-git-send-email-leo.yan@linaro.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1140 Lines: 32 In the code dumping ETB buffer is terminated when read back value 0xFFFF_FFFF. This is not safe and introduce infinite looping for some cases, e.g. when reset the CPU and read out ETB RAM. Cc: Mathieu Poirier Cc: Mike Leach Cc: Suzuki K Poulose Signed-off-by: Leo Yan --- drivers/hwtracing/coresight/coresight-tmc-etf.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/hwtracing/coresight/coresight-tmc-etf.c b/drivers/hwtracing/coresight/coresight-tmc-etf.c index 3a1c181..6150dac 100644 --- a/drivers/hwtracing/coresight/coresight-tmc-etf.c +++ b/drivers/hwtracing/coresight/coresight-tmc-etf.c @@ -54,6 +54,13 @@ static void tmc_etb_dump_hw(struct tmc_drvdata *drvdata) read_data = readl_relaxed(drvdata->base + TMC_RRD); if (read_data == 0xFFFFFFFF) return; + + /* Check if allocated buffer is overflow */ + if (drvdata->len >= drvdata->size) { + dev_info(drvdata->dev, "TMC dump overflow!\n"); + return; + } + memcpy(bufp, &read_data, 4); bufp += 4; drvdata->len += 4; -- 2.7.4