From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754731Ab1ASTTp (ORCPT ); Wed, 19 Jan 2011 14:19:45 -0500 Received: from hera.kernel.org ([140.211.167.34]:49581 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754435Ab1ASTTm (ORCPT ); Wed, 19 Jan 2011 14:19:42 -0500 Date: Wed, 19 Jan 2011 19:19:12 GMT From: tip-bot for Oleg Nesterov Cc: linux-kernel@vger.kernel.org, paulus@samba.org, acme@redhat.com, hpa@zytor.com, mingo@redhat.com, stern@rowland.harvard.edu, a.p.zijlstra@chello.nl, roland@redhat.com, fweisbec@gmail.com, tglx@linutronix.de, oleg@redhat.com, mingo@elte.hu, prasad@linux.vnet.ibm.com Reply-To: mingo@redhat.com, hpa@zytor.com, acme@redhat.com, paulus@samba.org, linux-kernel@vger.kernel.org, stern@rowland.harvard.edu, a.p.zijlstra@chello.nl, fweisbec@gmail.com, roland@redhat.com, oleg@redhat.com, tglx@linutronix.de, prasad@linux.vnet.ibm.com, mingo@elte.hu In-Reply-To: <20110119182228.GC12183@redhat.com> References: <20110119182228.GC12183@redhat.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:perf/urgent] perf: Fix perf_event_init_task()/perf_event_free_task() interaction Message-ID: Git-Commit-ID: 8550d7cb6ed6c89add49c3b6ad4c753ab8a3d7f9 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.3 (hera.kernel.org [127.0.0.1]); Wed, 19 Jan 2011 19:19:12 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 8550d7cb6ed6c89add49c3b6ad4c753ab8a3d7f9 Gitweb: http://git.kernel.org/tip/8550d7cb6ed6c89add49c3b6ad4c753ab8a3d7f9 Author: Oleg Nesterov AuthorDate: Wed, 19 Jan 2011 19:22:28 +0100 Committer: Ingo Molnar CommitDate: Wed, 19 Jan 2011 20:04:28 +0100 perf: Fix perf_event_init_task()/perf_event_free_task() interaction perf_event_init_task() should clear child->perf_event_ctxp[] before anything else. Otherwise, if perf_event_init_context(perf_hw_context) fails, perf_event_free_task() can free perf_event_ctxp[perf_sw_context] copied from parent->perf_event_ctxp[] by dup_task_struct(). Also move the initialization of perf_event_mutex and perf_event_list from perf_event_init_context() to perf_event_init_context(). Signed-off-by: Oleg Nesterov Acked-by: Peter Zijlstra Cc: Alan Stern Cc: Arnaldo Carvalho de Melo Cc: Frederic Weisbecker Cc: Paul Mackerras Cc: Prasad Cc: Roland McGrath LKML-Reference: <20110119182228.GC12183@redhat.com> Signed-off-by: Ingo Molnar --- kernel/perf_event.c | 9 ++++----- 1 files changed, 4 insertions(+), 5 deletions(-) diff --git a/kernel/perf_event.c b/kernel/perf_event.c index 4ec55ef..244ca3a 100644 --- a/kernel/perf_event.c +++ b/kernel/perf_event.c @@ -6446,11 +6446,6 @@ int perf_event_init_context(struct task_struct *child, int ctxn) unsigned long flags; int ret = 0; - child->perf_event_ctxp[ctxn] = NULL; - - mutex_init(&child->perf_event_mutex); - INIT_LIST_HEAD(&child->perf_event_list); - if (likely(!parent->perf_event_ctxp[ctxn])) return 0; @@ -6539,6 +6534,10 @@ int perf_event_init_task(struct task_struct *child) { int ctxn, ret; + memset(child->perf_event_ctxp, 0, sizeof(child->perf_event_ctxp)); + mutex_init(&child->perf_event_mutex); + INIT_LIST_HEAD(&child->perf_event_list); + for_each_task_context_nr(ctxn) { ret = perf_event_init_context(child, ctxn); if (ret)