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 X-Spam-Level: X-Spam-Status: No, score=-17.4 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT, USER_IN_DEF_DKIM_WL 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 23074C433FF for ; Mon, 5 Aug 2019 23:37:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E5E2A214C6 for ; Mon, 5 Aug 2019 23:37:53 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="teLFSQzd" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731185AbfHEXhx (ORCPT ); Mon, 5 Aug 2019 19:37:53 -0400 Received: from mail-pg1-f201.google.com ([209.85.215.201]:37093 "EHLO mail-pg1-f201.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730733AbfHEXhw (ORCPT ); Mon, 5 Aug 2019 19:37:52 -0400 Received: by mail-pg1-f201.google.com with SMTP id n9so50228295pgq.4 for ; Mon, 05 Aug 2019 16:37:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:message-id:mime-version:subject:from:to:cc; bh=fBjJNFjoK1CAcW2n/5qAZBcAEg4a650LiNHBPnT1bA8=; b=teLFSQzdFhTree3GuH3s2GuOa3/Qab921rb+2lHcsNF3Q36mmpwBTCwosqfJMXKhRF ehSuAk72xI064YEL3vjbaFafFs9TTuIwStWRcNBJl0PITAgIhImi5Hte9gT6Z6JVA5QU GCdGwMMTfclbzqcWnR+tmYtxu2dBqp053GvGc2DHX76PMWaPsDX43n5BWxgfeHfjfv94 ajnNeldBRDSHzNLzKuChwzT2zFyoIXqBPYgaxOmmSipvwGNsEC2SFwQR61tHNK+/L4V8 8BQjqzD/GqzUxPY9AloyABiNCCpOUNuO+m0D/Wn+JpgVohng7LkFJGjmC6J3t3/kdtZU UMQg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:message-id:mime-version:subject:from:to:cc; bh=fBjJNFjoK1CAcW2n/5qAZBcAEg4a650LiNHBPnT1bA8=; b=Bqu/ab8fbXVGwZjitbT3NJpWJebxCyWiiojxLbxvF0IoADk5M1T3pNWZi6nLaNUwCl Amzov7qnxw6tNRgzT+oHaG0Ko3j3JCcOnqWoM4z//w3As6rF0fRvB+ttMc3QfhN8vtFA DTH8umSAokdyp6lgArF362u8T97kDMMdWiLv60PpA9c+hCctsU2raG1ETo1oa+Ehi8nt yeAxctQWrDvi0cg5tGHObxTXScVWFu6ffdmTUthsBieYLDe1cm4nZLSY5mzPq1uoxXAc Cl8IaWstSWqSUZEI3xVTp5gs09Jrjb+EbpRoioJjro2AhxWVYNTkGRTUgy8+8LiexRk4 thpw== X-Gm-Message-State: APjAAAUyOfe+D5U+TVl3+6W5PKOFOesmTjA+7Li+fAX1ucByoWDJ+f5N QpRNJEP0vAp3g+dpclHHwC6A2urZCg== X-Google-Smtp-Source: APXvYqzElEKumTXzdjS5AKxhg+INSn2hflNMrkQU+AM6dd6TOj81EETimI6pwSS2tR7xd/O69Zccw7xtJRQ= X-Received: by 2002:a63:6eca:: with SMTP id j193mr367802pgc.74.1565048271547; Mon, 05 Aug 2019 16:37:51 -0700 (PDT) Date: Mon, 5 Aug 2019 16:37:38 -0700 Message-Id: <20190805233738.136357-1-yabinc@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.22.0.770.g0f2c4a37fd-goog Subject: [PATCH] coresight: tmc-etr: Fix updating buffer in not-snapshot mode. From: Yabin Cui To: Mathieu Poirier , Suzuki K Poulose , Alexander Shishkin Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Yabin Cui Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org TMC etr always copies all available data to perf aux buffer, which may exceed the available space in perf aux buffer. It isn't suitable for not-snapshot mode, because: 1) It may overwrite previously written data. 2) It may make the perf_event_mmap_page->aux_head report having more or less data than the reality. Signed-off-by: Yabin Cui --- drivers/hwtracing/coresight/coresight-tmc-etr.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c index 17006705287a..697e68d492af 100644 --- a/drivers/hwtracing/coresight/coresight-tmc-etr.c +++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c @@ -1410,9 +1410,10 @@ static void tmc_free_etr_buffer(void *config) * tmc_etr_sync_perf_buffer: Copy the actual trace data from the hardware * buffer to the perf ring buffer. */ -static void tmc_etr_sync_perf_buffer(struct etr_perf_buffer *etr_perf) +static void tmc_etr_sync_perf_buffer(struct etr_perf_buffer *etr_perf, + unsigned long to_copy) { - long bytes, to_copy; + long bytes; long pg_idx, pg_offset, src_offset; unsigned long head = etr_perf->head; char **dst_pages, *src_buf; @@ -1423,7 +1424,6 @@ static void tmc_etr_sync_perf_buffer(struct etr_perf_buffer *etr_perf) pg_offset = head & (PAGE_SIZE - 1); dst_pages = (char **)etr_perf->pages; src_offset = etr_buf->offset; - to_copy = etr_buf->len; while (to_copy > 0) { /* @@ -1501,7 +1501,11 @@ tmc_update_etr_buffer(struct coresight_device *csdev, spin_unlock_irqrestore(&drvdata->spinlock, flags); size = etr_buf->len; - tmc_etr_sync_perf_buffer(etr_perf); + if (!etr_perf->snapshot && size > handle->size) { + size = handle->size; + lost = true; + } + tmc_etr_sync_perf_buffer(etr_perf, size); /* * In snapshot mode we simply increment the head by the number of byte -- 2.22.0.770.g0f2c4a37fd-goog