From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754737Ab3ILLMQ (ORCPT ); Thu, 12 Sep 2013 07:12:16 -0400 Received: from terminus.zytor.com ([198.137.202.10]:34456 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754497Ab3ILLLz (ORCPT ); Thu, 12 Sep 2013 07:11:55 -0400 Date: Thu, 12 Sep 2013 04:11:37 -0700 From: tip-bot for Oleg Nesterov Message-ID: Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@kernel.org, hkshaw@linux.vnet.ibm.com, anton@redhat.com, tglx@linutronix.de, oleg@redhat.com, Mikhail.Kulemin@ru.ibm.com Reply-To: mingo@kernel.org, hpa@zytor.com, linux-kernel@vger.kernel.org, hkshaw@linux.vnet.ibm.com, anton@redhat.com, tglx@linutronix.de, oleg@redhat.com, Mikhail.Kulemin@ru.ibm.com In-Reply-To: <20130911154726.GA8093@redhat.com> References: <20130911154726.GA8093@redhat.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:perf/urgent] uprobes: Fix utask-> depth accounting in handle_trampoline() Git-Commit-ID: 878b5a6efd38030c7a90895dc8346e8fb1e09b4c 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 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.7 (terminus.zytor.com [127.0.0.1]); Thu, 12 Sep 2013 04:11:44 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 878b5a6efd38030c7a90895dc8346e8fb1e09b4c Gitweb: http://git.kernel.org/tip/878b5a6efd38030c7a90895dc8346e8fb1e09b4c Author: Oleg Nesterov AuthorDate: Wed, 11 Sep 2013 17:47:26 +0200 Committer: Ingo Molnar CommitDate: Thu, 12 Sep 2013 08:00:55 +0200 uprobes: Fix utask->depth accounting in handle_trampoline() Currently utask->depth is simply the number of allocated/pending return_instance's in uprobe_task->return_instances list. handle_trampoline() should decrement this counter every time we handle/free an instance, but due to typo it does this only if ->chained == T. This means that in the likely case this counter is never decremented and the probed task can't report more than MAX_URETPROBE_DEPTH events. Reported-by: Mikhail Kulemin Reported-by: Hemant Kumar Shaw Signed-off-by: Oleg Nesterov Acked-by: Anton Arapov Cc: masami.hiramatsu.pt@hitachi.com Cc: srikar@linux.vnet.ibm.com Cc: systemtap@sourceware.org Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/20130911154726.GA8093@redhat.com Signed-off-by: Ingo Molnar --- kernel/events/uprobes.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index f356974..ad8e1bd 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -1682,12 +1682,10 @@ static bool handle_trampoline(struct pt_regs *regs) tmp = ri; ri = ri->next; kfree(tmp); + utask->depth--; if (!chained) break; - - utask->depth--; - BUG_ON(!ri); }