From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752961AbeC2N7K (ORCPT ); Thu, 29 Mar 2018 09:59:10 -0400 Received: from terminus.zytor.com ([198.137.202.136]:46643 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752374AbeC2N7J (ORCPT ); Thu, 29 Mar 2018 09:59:09 -0400 Date: Thu, 29 Mar 2018 06:58:58 -0700 From: tip-bot for Arnaldo Carvalho de Melo Message-ID: Cc: dsahern@gmail.com, hpa@zytor.com, wangnan0@huawei.com, kan.liang@intel.com, acme@redhat.com, tglx@linutronix.de, jolsa@kernel.org, namhyung@kernel.org, linux-kernel@vger.kernel.org, adrian.hunter@intel.com, mingo@kernel.org Reply-To: adrian.hunter@intel.com, mingo@kernel.org, linux-kernel@vger.kernel.org, hpa@zytor.com, dsahern@gmail.com, jolsa@kernel.org, namhyung@kernel.org, kan.liang@intel.com, wangnan0@huawei.com, acme@redhat.com, tglx@linutronix.de In-Reply-To: <20180326144127.GF18897@kernel.org> References: <20180326144127.GF18897@kernel.org> To: linux-tip-commits@vger.kernel.org Subject: [tip:perf/core] perf mmap: Be consistent when checking for an unmaped ring buffer Git-Commit-ID: 895e3b06fc2ce438adc62cb13d31ea001dcfda16 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 895e3b06fc2ce438adc62cb13d31ea001dcfda16 Gitweb: https://git.kernel.org/tip/895e3b06fc2ce438adc62cb13d31ea001dcfda16 Author: Arnaldo Carvalho de Melo AuthorDate: Mon, 26 Mar 2018 11:42:15 -0300 Committer: Arnaldo Carvalho de Melo CommitDate: Tue, 27 Mar 2018 13:13:38 -0300 perf mmap: Be consistent when checking for an unmaped ring buffer The previous patch is insufficient to cure the reported 'perf trace' segfault, as it only cures the perf_mmap__read_done() case, moving the segfault to perf_mmap__read_init() functio, fix it by doing the same refcount check. Cc: Adrian Hunter Cc: Arnaldo Carvalho de Melo Cc: David Ahern Cc: Jiri Olsa Cc: Kan Liang Cc: Namhyung Kim Cc: Wang Nan Fixes: 8872481bd048 ("perf mmap: Introduce perf_mmap__read_init()") Link: https://lkml.kernel.org/r/20180326144127.GF18897@kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/mmap.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/tools/perf/util/mmap.c b/tools/perf/util/mmap.c index f6cfc52ff1fe..fc832676a798 100644 --- a/tools/perf/util/mmap.c +++ b/tools/perf/util/mmap.c @@ -234,7 +234,7 @@ static int overwrite_rb_find_range(void *buf, int mask, u64 *start, u64 *end) /* * Report the start and end of the available data in ringbuffer */ -int perf_mmap__read_init(struct perf_mmap *md) +static int __perf_mmap__read_init(struct perf_mmap *md) { u64 head = perf_mmap__read_head(md); u64 old = md->prev; @@ -268,6 +268,17 @@ int perf_mmap__read_init(struct perf_mmap *md) return 0; } +int perf_mmap__read_init(struct perf_mmap *map) +{ + /* + * Check if event was unmapped due to a POLLHUP/POLLERR. + */ + if (!refcount_read(&map->refcnt)) + return -ENOENT; + + return __perf_mmap__read_init(map); +} + int perf_mmap__push(struct perf_mmap *md, void *to, int push(void *to, void *buf, size_t size)) {