From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 97D7EC001DB for ; Thu, 3 Aug 2023 16:19:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236022AbjHCQTh (ORCPT ); Thu, 3 Aug 2023 12:19:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56444 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234935AbjHCQTf (ORCPT ); Thu, 3 Aug 2023 12:19:35 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id CCA4F3AA6 for ; Thu, 3 Aug 2023 09:19:33 -0700 (PDT) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 819D2113E; Thu, 3 Aug 2023 09:20:16 -0700 (PDT) Received: from [10.57.90.14] (unknown [10.57.90.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 624213F5A1; Thu, 3 Aug 2023 09:19:32 -0700 (PDT) Message-ID: <0410712c-d658-8f54-5a29-699a68bc0dea@arm.com> Date: Thu, 3 Aug 2023 17:19:30 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:102.0) Gecko/20100101 Thunderbird/102.13.0 Subject: Re: [PATCH v2] coresight: tmc: Explicit type conversions to prevent integer overflow To: Ruidong Tian Cc: alexander.shishkin@linux.intel.com, coresight@lists.linaro.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, mike.leach@linaro.org, james.clark@arm.com References: <20230714084349.31567-1-tianruidong@linux.alibaba.com> <20230803023321.111078-1-tianruidong@linux.alibaba.com> From: Suzuki K Poulose In-Reply-To: <20230803023321.111078-1-tianruidong@linux.alibaba.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 03/08/2023 03:33, Ruidong Tian wrote: > Perf cs_etm session executed unexpectedly when AUX buffer > 1G. > > perf record -C 0 -m ,2G -e cs_etm// -- > [ perf record: Captured and wrote 2.615 MB perf.data ] > > Perf only collect about 2M perf data rather than 2G. This is becasuse > the operation, "nr_pages << PAGE_SHIFT", in coresight tmc driver, will > overflow when nr_pages >= 0x80000(correspond to 1G AUX buffer). The > overflow cause buffer allocation to fail, and TMC driver will alloc > minimal buffer size(1M). You can just get about 2M perf data(1M AUX > buffer + perf data header) at least. > > Explicit convert nr_pages to 64 bit to avoid overflow. > > Signed-off-by: Ruidong Tian > Reviewed-by: James Clark Fixes: 22f429f19c41 ("coresight: etm-perf: Add support for ETR backend") > --- > drivers/hwtracing/coresight/coresight-tmc-etr.c | 2 +- > drivers/hwtracing/coresight/coresight-tmc.h | 2 +- > 2 files changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c > index 766325de0e29..1425ecd1cf78 100644 > --- a/drivers/hwtracing/coresight/coresight-tmc-etr.c > +++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c > @@ -1267,7 +1267,7 @@ alloc_etr_buf(struct tmc_drvdata *drvdata, struct perf_event *event, > * than the size requested via sysfs. > */ > if ((nr_pages << PAGE_SHIFT) > drvdata->size) { > - etr_buf = tmc_alloc_etr_buf(drvdata, (nr_pages << PAGE_SHIFT), > + etr_buf = tmc_alloc_etr_buf(drvdata, ((ssize_t)nr_pages << PAGE_SHIFT), > 0, node, NULL); > if (!IS_ERR(etr_buf)) > goto done; > diff --git a/drivers/hwtracing/coresight/coresight-tmc.h b/drivers/hwtracing/coresight/coresight-tmc.h > index b97da39652d2..0ee48c5ba764 100644 > --- a/drivers/hwtracing/coresight/coresight-tmc.h > +++ b/drivers/hwtracing/coresight/coresight-tmc.h > @@ -325,7 +325,7 @@ ssize_t tmc_sg_table_get_data(struct tmc_sg_table *sg_table, > static inline unsigned long > tmc_sg_table_buf_size(struct tmc_sg_table *sg_table) > { > - return sg_table->data_pages.nr_pages << PAGE_SHIFT; > + return (unsigned long)sg_table->data_pages.nr_pages << PAGE_SHIFT; > } > > struct coresight_device *tmc_etr_get_catu_device(struct tmc_drvdata *drvdata); There are other places where such a fix is needed. e.g., $ git grep "nr_pages << PAGE_SHIFT" drivers/hwtracing/coresight/coresight-tmc* drivers/hwtracing/coresight/coresight-tmc-etf.c: head = handle->head & ((buf->nr_pages << PAGE_SHIFT) - 1); drivers/hwtracing/coresight/coresight-tmc-etr.c:#define PERF_IDX2OFF(idx, buf) ((idx) % ((buf)->nr_pages << PAGE_SHIFT)) drivers/hwtracing/coresight/coresight-tmc-etr.c: if ((nr_pages << PAGE_SHIFT) > drvdata->size) { drivers/hwtracing/coresight/coresight-tmc-etr.c: etr_buf = tmc_alloc_etr_buf(drvdata, (nr_pages << PAGE_SHIFT), drivers/hwtracing/coresight/coresight-tmc.h: return sg_table->data_pages.nr_pages << PAGE_SHIFT; Are you able to fix all of them ? Suzuki