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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 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 8C1B2C432C3 for ; Fri, 15 Nov 2019 09:05:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6B5E220732 for ; Fri, 15 Nov 2019 09:05:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727064AbfKOJFT (ORCPT ); Fri, 15 Nov 2019 04:05:19 -0500 Received: from mga11.intel.com ([192.55.52.93]:60095 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725829AbfKOJFS (ORCPT ); Fri, 15 Nov 2019 04:05:18 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmsmga102.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 15 Nov 2019 01:05:18 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.68,307,1569308400"; d="scan'208";a="379874420" Received: from linux.intel.com ([10.54.29.200]) by orsmga005.jf.intel.com with ESMTP; 15 Nov 2019 01:05:17 -0800 Received: from [10.125.252.175] (abudanko-mobl.ccr.corp.intel.com [10.125.252.175]) by linux.intel.com (Postfix) with ESMTP id DD84F5802B1; Fri, 15 Nov 2019 01:05:15 -0800 (PST) From: Alexey Budankov Organization: Intel Corp. To: Arnaldo Carvalho de Melo Subject: [PATCH v1] perf session: fix decompression of PERF_RECORD_COMPRESSED records Cc: Jiri Olsa , Namhyung Kim , Peter Zijlstra , Alexander Shishkin , Ingo Molnar , Andi Kleen , linux-kernel Message-ID: <237222f1-9765-dce1-601c-60530a7fc844@linux.intel.com> Date: Fri, 15 Nov 2019 12:05:14 +0300 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.9.1 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Avoid termination of trace loading in case the last record in the decompressed buffer partly resides in the following mmaped PERF_RECORD_COMPRESSED record. In this case NULL value returned by fetch_mmaped_event() means to proceed to the next mmaped record then decompress it and load compressed events. The issue can be reproduced like this: $ perf record -z -- some_long_running_workload $ perf report --stdio -vv decomp (B): 44519 to 163000 decomp (B): 48119 to 174800 decomp (B): 65527 to 131072 fetch_mmaped_event: head=0x1ffe0 event->header_size=0x28, mmap_size=0x20000: fuzzed perf.data? Error: failed to process sample ... Testing: 71: Zstd perf.data compression/decompression : Ok Fixes: 57fc032ad643 ("perf session: Avoid infinite loop when seeing invalid header.size") Link: https://marc.info/?l=linux-kernel&m=156580812427554&w=2 Co-developed-by: Jiri Olsa Signed-off-by: Alexey Budankov --- tools/perf/util/session.c | 47 +++++++++++++++++++++++++++++++++-------------- 1 file changed, 33 insertions(+), 14 deletions(-) diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c index f07b8ecb91bc..3f6f812ec4ed 100644 --- a/tools/perf/util/session.c +++ b/tools/perf/util/session.c @@ -1957,9 +1957,31 @@ static int __perf_session__process_pipe_events(struct perf_session *session) return err; } +static union perf_event * +prefetch_event(char *buf, u64 head, size_t mmap_size, + bool needs_swap, union perf_event *ret); + static union perf_event * fetch_mmaped_event(struct perf_session *session, u64 head, size_t mmap_size, char *buf) +{ + return prefetch_event(buf, head, mmap_size, + session->header.needs_swap, + ERR_PTR(-EINVAL)); +} + +static union perf_event * +fetch_decomp_event(struct perf_session *session, + u64 head, size_t mmap_size, char *buf) +{ + return prefetch_event(buf, head, mmap_size, + session->header.needs_swap, + NULL); +} + +static union perf_event * +prefetch_event(char *buf, u64 head, size_t mmap_size, + bool needs_swap, union perf_event *ret) { union perf_event *event; @@ -1971,20 +1993,20 @@ fetch_mmaped_event(struct perf_session *session, return NULL; event = (union perf_event *)(buf + head); + if (needs_swap) + perf_event_header__bswap(&event->header); - if (session->header.needs_swap) + if (head + event->header.size <= mmap_size) + return event; + + /* We're not fetching the event so swap back again */ + if (needs_swap) perf_event_header__bswap(&event->header); - if (head + event->header.size > mmap_size) { - /* We're not fetching the event so swap back again */ - if (session->header.needs_swap) - perf_event_header__bswap(&event->header); - pr_debug("%s: head=%#" PRIx64 " event->header_size=%#x, mmap_size=%#zx: fuzzed perf.data?\n", - __func__, head, event->header.size, mmap_size); - return ERR_PTR(-EINVAL); - } + pr_debug("%s: head=%#" PRIx64 " event->header_size=%#x, mmap_size=%#zx\n", + __func__, head, event->header.size, mmap_size); - return event; + return ret; } static int __perf_session__process_decomp_events(struct perf_session *session) @@ -1997,10 +2019,7 @@ static int __perf_session__process_decomp_events(struct perf_session *session) return 0; while (decomp->head < decomp->size && !session_done()) { - union perf_event *event = fetch_mmaped_event(session, decomp->head, decomp->size, decomp->data); - - if (IS_ERR(event)) - return PTR_ERR(event); + union perf_event *event = fetch_decomp_event(session, decomp->head, decomp->size, decomp->data); if (!event) break;