From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751572AbdITNaQ (ORCPT ); Wed, 20 Sep 2017 09:30:16 -0400 Received: from mail.kernel.org ([198.145.29.99]:36006 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750892AbdITNaO (ORCPT ); Wed, 20 Sep 2017 09:30:14 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E4A0921EAA Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=goodmis.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=rostedt@goodmis.org Message-Id: <20170920133012.906504825@goodmis.org> User-Agent: quilt/0.63-1 Date: Wed, 20 Sep 2017 09:29:40 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Linus Torvalds , Ingo Molnar , Andrew Morton , "Ziqian SUN (Zamir)" Subject: [PATCH 2/3] tracing: Ignore mmiotrace from kernel commandline References: <20170920132938.098873640@goodmis.org> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Content-Disposition: inline; filename=0002-tracing-Ignore-mmiotrace-from-kernel-commandline.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "Ziqian SUN (Zamir)" The mmiotrace tracer cannot be enabled with ftrace=mmiotrace in kernel commandline. With this patch, noboot is added to the tracer struct, and when system boot with a tracer that has noboot=true, it will print out a warning message and continue booting. Link: http://lkml.kernel.org/r/1505111195-31942-1-git-send-email-zsun@redhat.com Signed-off-by: Ziqian SUN (Zamir) Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/trace.c | 7 +++++++ kernel/trace/trace.h | 2 ++ kernel/trace/trace_mmiotrace.c | 1 + 3 files changed, 10 insertions(+) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index a7fb136da891..d3ca35f38803 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -5364,6 +5364,13 @@ static int tracing_set_tracer(struct trace_array *tr, const char *buf) if (t == tr->current_trace) goto out; + /* Some tracers won't work on kernel command line */ + if (system_state < SYSTEM_RUNNING && t->noboot) { + pr_warn("Tracer '%s' is not allowed on command line, ignored\n", + t->name); + goto out; + } + /* Some tracers are only allowed for the top level buffer */ if (!trace_ok_for_array(t, tr)) { ret = -EINVAL; diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index fb5d54d0d1b3..652c682707cd 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -444,6 +444,8 @@ struct tracer { #ifdef CONFIG_TRACER_MAX_TRACE bool use_max_tr; #endif + /* True if tracer cannot be enabled in kernel param */ + bool noboot; }; diff --git a/kernel/trace/trace_mmiotrace.c b/kernel/trace/trace_mmiotrace.c index cd7480d0a201..dca78fc48439 100644 --- a/kernel/trace/trace_mmiotrace.c +++ b/kernel/trace/trace_mmiotrace.c @@ -282,6 +282,7 @@ static struct tracer mmio_tracer __read_mostly = .close = mmio_close, .read = mmio_read, .print_line = mmio_print_line, + .noboot = true, }; __init static int init_mmio_trace(void) -- 2.13.2