From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759060Ab2KBWpO (ORCPT ); Fri, 2 Nov 2012 18:45:14 -0400 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.122]:19944 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754052Ab2KBWpL (ORCPT ); Fri, 2 Nov 2012 18:45:11 -0400 X-Authority-Analysis: v=2.0 cv=dvhZ+ic4 c=1 sm=0 a=rXTBtCOcEpjy1lPqhTCpEQ==:17 a=mNMOxpOpBa8A:10 a=Ciwy3NGCPMMA:10 a=Yz3Bi5mCXbAA:10 a=5SG0PmZfjMsA:10 a=bbbx4UPp9XUA:10 a=meVymXHHAAAA:8 a=xSQHIVwy9PUA:10 a=20KFwNOVAAAA:8 a=FmuBU-rodUV_qrTzYOYA:9 a=jEp0ucaQiEUA:10 a=jeBq3FmKZ4MA:10 a=rXTBtCOcEpjy1lPqhTCpEQ==:117 X-Cloudmark-Score: 0 X-Originating-IP: 74.67.115.198 Message-Id: <20121102224509.791009824@goodmis.org> User-Agent: quilt/0.60-1 Date: Fri, 02 Nov 2012 18:38:29 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Ingo Molnar , Andrew Morton , Thomas Gleixner , Peter Zijlstra , Frederic Weisbecker Subject: [PATCH 1/8][RFC] ftrace: Fix global function tracers that are not recursion safe References: <20121102223828.795874032@goodmis.org> Content-Disposition: inline; filename=0001-ftrace-Fix-global-function-tracers-that-are-not-recu.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Steven Rostedt If one of the function tracers set by the global ops is not recursion safe, it can still be called directly without the added recursion supplied by the ftrace infrastructure. Signed-off-by: Steven Rostedt --- kernel/trace/ftrace.c | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-) diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 4451aa3..67e886e 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -221,10 +221,24 @@ static void update_global_ops(void) * registered callers. */ if (ftrace_global_list == &ftrace_list_end || - ftrace_global_list->next == &ftrace_list_end) + ftrace_global_list->next == &ftrace_list_end) { func = ftrace_global_list->func; - else + /* + * As we are calling the function directly. + * If it does not have recursion protection, + * the function_trace_op needs to be updated + * accordingly. + */ + if (ftrace_global_list->flags & FTRACE_OPS_FL_RECURSION_SAFE) + global_ops.flags |= FTRACE_OPS_FL_RECURSION_SAFE; + else + global_ops.flags &= ~FTRACE_OPS_FL_RECURSION_SAFE; + } else { func = ftrace_global_list_func; + /* The list has its own recursion protection. */ + global_ops.flags |= FTRACE_OPS_FL_RECURSION_SAFE; + } + /* If we filter on pids, update to use the pid function */ if (!list_empty(&ftrace_pids)) { -- 1.7.10.4