From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752068AbZI1Pm2 (ORCPT ); Mon, 28 Sep 2009 11:42:28 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751730AbZI1Pm1 (ORCPT ); Mon, 28 Sep 2009 11:42:27 -0400 Received: from 124x34x33x190.ap124.ftth.ucom.ne.jp ([124.34.33.190]:57118 "EHLO master.linux-sh.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751709AbZI1Pm1 (ORCPT ); Mon, 28 Sep 2009 11:42:27 -0400 From: Matt Fleming To: linux-kernel@vger.kernel.org Cc: Steven Rostedt , Frederic Weisbecker , Ingo Molnar Subject: [PATCH] tracing: Fix infinite loop in ftrace_update_pid_func() Date: Mon, 28 Sep 2009 16:43:01 +0100 Message-Id: <1254152581-18347-1-git-send-email-matt@console-pimps.org> X-Mailer: git-send-email 1.6.4.rc0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Matt Fleming When CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST is enabled __ftrace_trace_function contains the current trace function, not ftrace_trace_function. In ftrace_update_pid_func() we currently incorrectly assign the value of ftrace_trace_function to __ftrace_trace_funcion before returning. Without this patch it is possible to execute an infinite loop whereby ftrace_test_stop_func() calls __ftrace_trace_function, which was assigned ftrace_test_stop_func() in ftrace_update_pid_func(). Signed-off-by: Matt Fleming --- kernel/trace/ftrace.c | 4 ++++ 1 files changed, 4 insertions(+), 0 deletions(-) diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 25edd5c..d9ba6d9 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -225,7 +225,11 @@ static void ftrace_update_pid_func(void) if (ftrace_trace_function == ftrace_stub) return; +#ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST func = ftrace_trace_function; +#else + func = __ftrace_trace_function; +#endif if (ftrace_pid_trace) { set_ftrace_pid_function(func); -- 1.6.3.GIT