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=-10.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 4685FECDE4B for ; Thu, 8 Nov 2018 21:56:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0E6D72089A for ; Thu, 8 Nov 2018 21:56:36 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="oA2sXKD1" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0E6D72089A Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729222AbeKIHeA (ORCPT ); Fri, 9 Nov 2018 02:34:00 -0500 Received: from mail.kernel.org ([198.145.29.99]:50198 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729189AbeKIHdy (ORCPT ); Fri, 9 Nov 2018 02:33:54 -0500 Received: from localhost (unknown [208.72.13.198]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 390D420892; Thu, 8 Nov 2018 21:56:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1541714187; bh=TDwxN8a2Cl6OVpmax91PTFxvW7LqOwHe/+wxo65Qi+o=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=oA2sXKD1tzir9owIOa7Y0NJ6pd3zZCnU/PPvf93a5scq3upIeRh62JvgSGRdUeAst owLdgjyia4qb1yHI98isBKY0a+MBcJOz+p5nFJq4X+2xIuqGEnWm/2N9KyB+y6Qxrs A4Qy4mJ27hexynhUqEUWWwBtXp6VZaKR4NvjT5rk= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dmitry Vyukov , "Peter Zijlstra (Intel)" , Alexander Potapenko , Arnaldo Carvalho de Melo , Arnaldo Carvalho de Melo , Eric Dumazet , Jiri Olsa , Kostya Serebryany , Linus Torvalds , Sasha Levin , Stephane Eranian , Thomas Gleixner , Vince Weaver , Ingo Molnar , Sasha Levin Subject: [PATCH 3.18 112/144] perf: Fix PERF_EVENT_IOC_PERIOD deadlock Date: Thu, 8 Nov 2018 13:51:23 -0800 Message-Id: <20181108215105.986230598@linuxfoundation.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20181108215054.826084593@linuxfoundation.org> References: <20181108215054.826084593@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.18-stable review patch. If anyone has any objections, please let me know. ------------------ [ Upstream commit 642c2d671ceff40e9453203ea0c66e991e11e249 ] Dmitry reported a fairly silly recursive lock deadlock for PERF_EVENT_IOC_PERIOD, fix this by explicitly doing the inactive part of __perf_event_period() instead of calling that function. Reported-by: Dmitry Vyukov Signed-off-by: Peter Zijlstra (Intel) Cc: Cc: Alexander Potapenko Cc: Arnaldo Carvalho de Melo Cc: Arnaldo Carvalho de Melo Cc: Eric Dumazet Cc: Jiri Olsa Cc: Kostya Serebryany Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Sasha Levin Cc: Stephane Eranian Cc: Thomas Gleixner Cc: Vince Weaver Fixes: c7999c6f3fed ("perf: Fix PERF_EVENT_IOC_PERIOD migration race") Link: http://lkml.kernel.org/r/20151130115615.GJ17308@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar Signed-off-by: Sasha Levin --- kernel/events/core.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/kernel/events/core.c b/kernel/events/core.c index 1f08f691de59..7b2f9d432fe7 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -3929,7 +3929,14 @@ retry: goto retry; } - __perf_event_period(&pe); + if (event->attr.freq) { + event->attr.sample_freq = value; + } else { + event->attr.sample_period = value; + event->hw.sample_period = value; + } + + local64_set(&event->hw.period_left, 0); raw_spin_unlock_irq(&ctx->lock); return 0; -- 2.17.1