From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755841AbZFXBxU (ORCPT ); Tue, 23 Jun 2009 21:53:20 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753418AbZFXBxF (ORCPT ); Tue, 23 Jun 2009 21:53:05 -0400 Received: from cn.fujitsu.com ([222.73.24.84]:61927 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1753201AbZFXBxF (ORCPT ); Tue, 23 Jun 2009 21:53:05 -0400 Message-ID: <4A418738.7090401@cn.fujitsu.com> Date: Wed, 24 Jun 2009 09:54:00 +0800 From: Li Zefan User-Agent: Thunderbird 2.0.0.9 (X11/20071115) MIME-Version: 1.0 To: Ingo Molnar CC: Steven Rostedt , Frederic Weisbecker , Liming Wang , LKML Subject: [PATCH 5/7] ftrace: don't increment @pos in g_start() References: <4A4186C6.9090706@cn.fujitsu.com> In-Reply-To: <4A4186C6.9090706@cn.fujitsu.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org It's wrong to increment @pos in g_start(). It causes some entries lost when reading set_graph_function, if the output of the file is large than PAGE_SIZE. [ Impact: fix missing entries when reading set_graph_function ] Reviewed-by: Liming Wang Signed-off-by: Li Zefan --- kernel/trace/ftrace.c | 21 ++++++++++----------- 1 files changed, 10 insertions(+), 11 deletions(-) diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 561cafc..c06e9ab 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -2499,32 +2499,31 @@ int ftrace_graph_count; unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly; static void * -g_next(struct seq_file *m, void *v, loff_t *pos) +__g_next(struct seq_file *m, loff_t *pos) { unsigned long *array = m->private; - int index = *pos; - - (*pos)++; - if (index >= ftrace_graph_count) + if (*pos >= ftrace_graph_count) return NULL; + return &array[*pos]; +} - return &array[index]; +static void * +g_next(struct seq_file *m, void *v, loff_t *pos) +{ + (*pos)++; + return __g_next(m, pos); } static void *g_start(struct seq_file *m, loff_t *pos) { - void *p = NULL; - mutex_lock(&graph_lock); /* Nothing, tell g_show to print all functions are enabled */ if (!ftrace_graph_count && !*pos) return (void *)1; - p = g_next(m, p, pos); - - return p; + return __g_next(m, pos); } static void g_stop(struct seq_file *m, void *p) -- 1.5.4.rc3