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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6B389C433EF for ; Mon, 4 Oct 2021 13:30:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 550A1610A5 for ; Mon, 4 Oct 2021 13:30:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237312AbhJDNcQ (ORCPT ); Mon, 4 Oct 2021 09:32:16 -0400 Received: from mail.kernel.org ([198.145.29.99]:43492 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237735AbhJDNaW (ORCPT ); Mon, 4 Oct 2021 09:30:22 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 1315361B3E; Mon, 4 Oct 2021 13:13:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1633353220; bh=a4zoJc5uapeK376WmBaJPS7Dvv8GZptPeFqhDydmTFw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=GmHhHmDr6ouJIQq4pG2gOi5Lbdpl94PVLcYdH2BGF0UqIoooBSP9TE8ief8s6V6D5 0OuHrAsWe4cyjpvo1UmD0+Vjm9d0TCFwIiRowDCvVTYe0ePitGbhYrI9YjHUhNuTmW Sjm1IKt/80/Kaz0ZJB7kNhqbbZOJ+dcGSz0qa80o= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Like Xu , Alexander Antonov , Alexander Shishkin , Ian Rogers , Jiri Olsa , Mark Rutland , Namhyung Kim , Peter Zijlstra , Stephane Eranian , Arnaldo Carvalho de Melo , Sasha Levin Subject: [PATCH 5.14 025/172] perf iostat: Fix Segmentation fault from NULL struct perf_counts_values * Date: Mon, 4 Oct 2021 14:51:15 +0200 Message-Id: <20211004125045.781798191@linuxfoundation.org> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20211004125044.945314266@linuxfoundation.org> References: <20211004125044.945314266@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Like Xu [ Upstream commit 4da8b121884d84476f3d50d46a471471af1aa9df ] If the 'perf iostat' user specifies two or more iio_root_ports and also specifies the cpu(s) by -C which is not *connected to all* the above iio ports, the iostat_print_metric() will run into trouble: For example: $ perf iostat list S0-uncore_iio_0<0000:16> S1-uncore_iio_0<0000:97> # <--- CPU 1 is located in the socket S0 $ perf iostat 0000:16,0000:97 -C 1 -- ls port Inbound Read(MB) Inbound Write(MB) Outbound Read(MB) Outbound Write(MB) ../perf-iostat: line 12: 104418 Segmentation fault (core dumped) perf stat --iostat$DELIMITER$* The core-dump stack says, in the above corner case, the returned (struct perf_counts_values *) count will be NULL, and the caller iostat_print_metric() apparently doesn't not handle this case. 433 struct perf_counts_values *count = perf_counts(evsel->counts, die, 0); 434 435 if (count->run && count->ena) { (gdb) p count $1 = (struct perf_counts_values *) 0x0 The deeper reason is that there are actually no statistics from the user specified pair "iostat 0000:X, -C (disconnected) Y ", but let's fix it with minimum cost by adding a NULL check in the user space. Fixes: f9ed693e8bc0e7de ("perf stat: Enable iostat mode for x86 platforms") Signed-off-by: Like Xu Cc: Alexander Antonov Cc: Alexander Shishkin Cc: Ian Rogers Cc: Jiri Olsa Cc: Mark Rutland Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Stephane Eranian Link: http://lore.kernel.org/lkml/20210927081115.39568-2-likexu@tencent.com Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Sasha Levin --- tools/perf/arch/x86/util/iostat.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/perf/arch/x86/util/iostat.c b/tools/perf/arch/x86/util/iostat.c index eeafe97b8105..792cd75ade33 100644 --- a/tools/perf/arch/x86/util/iostat.c +++ b/tools/perf/arch/x86/util/iostat.c @@ -432,7 +432,7 @@ void iostat_print_metric(struct perf_stat_config *config, struct evsel *evsel, u8 die = ((struct iio_root_port *)evsel->priv)->die; struct perf_counts_values *count = perf_counts(evsel->counts, die, 0); - if (count->run && count->ena) { + if (count && count->run && count->ena) { if (evsel->prev_raw_counts && !out->force_header) { struct perf_counts_values *prev_count = perf_counts(evsel->prev_raw_counts, die, 0); -- 2.33.0