From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759093AbZFXJrx (ORCPT ); Wed, 24 Jun 2009 05:47:53 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758921AbZFXJrg (ORCPT ); Wed, 24 Jun 2009 05:47:36 -0400 Received: from hera.kernel.org ([140.211.167.34]:59782 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758891AbZFXJre (ORCPT ); Wed, 24 Jun 2009 05:47:34 -0400 Date: Wed, 24 Jun 2009 09:46:55 GMT From: tip-bot for Li Zefan To: linux-tip-commits@vger.kernel.org Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@redhat.com, lizf@cn.fujitsu.com, fweisbec@gmail.com, rostedt@goodmis.org, tglx@linutronix.de, liming.wang@windriver.com, mingo@elte.hu Reply-To: mingo@redhat.com, hpa@zytor.com, linux-kernel@vger.kernel.org, fweisbec@gmail.com, rostedt@goodmis.org, lizf@cn.fujitsu.com, tglx@linutronix.de, liming.wang@windriver.com, mingo@elte.hu In-Reply-To: <4A41876E.2060407@cn.fujitsu.com> References: <4A41876E.2060407@cn.fujitsu.com> Subject: [tip:tracing/urgent] ftrace: Fix t_hash_start() Message-ID: Git-Commit-ID: d82d62444f87e5993af2fa82ed636b2206e052ea X-Mailer: tip-git-log-daemon MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.0 (hera.kernel.org [127.0.0.1]); Wed, 24 Jun 2009 09:46:56 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: d82d62444f87e5993af2fa82ed636b2206e052ea Gitweb: http://git.kernel.org/tip/d82d62444f87e5993af2fa82ed636b2206e052ea Author: Li Zefan AuthorDate: Wed, 24 Jun 2009 09:54:54 +0800 Committer: Ingo Molnar CommitDate: Wed, 24 Jun 2009 11:02:53 +0200 ftrace: Fix t_hash_start() When the output of set_ftrace_filter is larger than PAGE_SIZE, t_hash_start() will be called the 2nd time, and then we start from the head of a hlist, which is wrong and causes some entries to be outputed twice. The worse is, if the hlist is large enough, reading set_ftrace_filter won't stop but in a dead loop. Reviewed-by: Liming Wang Signed-off-by: Li Zefan Cc: Steven Rostedt Cc: Frederic Weisbecker LKML-Reference: <4A41876E.2060407@cn.fujitsu.com> Signed-off-by: Ingo Molnar --- kernel/trace/ftrace.c | 12 +++++++++++- 1 files changed, 11 insertions(+), 1 deletions(-) diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index dc81020..71a52c1 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -1417,10 +1417,20 @@ static void *t_hash_start(struct seq_file *m, loff_t *pos) { struct ftrace_iterator *iter = m->private; void *p = NULL; + loff_t l; + + if (!(iter->flags & FTRACE_ITER_HASH)) + *pos = 0; iter->flags |= FTRACE_ITER_HASH; - return t_hash_next(m, p, pos); + iter->hidx = 0; + for (l = 0; l <= *pos; ) { + p = t_hash_next(m, p, &l); + if (!p) + break; + } + return p; } static int t_hash_show(struct seq_file *m, void *v)