From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756767AbZBSRIn (ORCPT ); Thu, 19 Feb 2009 12:08:43 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753171AbZBSRIf (ORCPT ); Thu, 19 Feb 2009 12:08:35 -0500 Received: from mx2.mail.elte.hu ([157.181.151.9]:60230 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752414AbZBSRIe (ORCPT ); Thu, 19 Feb 2009 12:08:34 -0500 Date: Thu, 19 Feb 2009 18:08:18 +0100 From: Ingo Molnar To: Linus Torvalds Cc: linux-kernel@vger.kernel.org, Andrew Morton , Steven Rostedt Subject: [git pull] tracing fixes Message-ID: <20090219170818.GA27350@elte.hu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.18 (2008-05-17) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.3 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Linus, Please pull the latest tracing-fixes-for-linus git tree from: git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip.git tracing-fixes-for-linus Thanks, Ingo ------------------> Frederic Weisbecker (1): tracing/function-graph-tracer: trace the idle tasks Steven Rostedt (3): tracing: disable tracing while testing ring buffer tracing: have function trace select kallsyms tracing: limit the number of loops the ring buffer self test can make kernel/trace/Kconfig | 2 ++ kernel/trace/ftrace.c | 6 +++++- kernel/trace/trace_selftest.c | 19 +++++++++++++++++++ 3 files changed, 26 insertions(+), 1 deletions(-) diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 58a93fb..34e707e 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -52,6 +52,7 @@ config FUNCTION_TRACER depends on HAVE_FUNCTION_TRACER depends on DEBUG_KERNEL select FRAME_POINTER + select KALLSYMS select TRACING select CONTEXT_SWITCH_TRACER help @@ -238,6 +239,7 @@ config STACK_TRACER depends on DEBUG_KERNEL select FUNCTION_TRACER select STACKTRACE + select KALLSYMS help This special tracer records the maximum stack footprint of the kernel and displays it in debugfs/tracing/stack_trace. diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 9a236ff..fdf913d 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -2033,7 +2033,7 @@ free: static int start_graph_tracing(void) { struct ftrace_ret_stack **ret_stack_list; - int ret; + int ret, cpu; ret_stack_list = kmalloc(FTRACE_RETSTACK_ALLOC_SIZE * sizeof(struct ftrace_ret_stack *), @@ -2042,6 +2042,10 @@ static int start_graph_tracing(void) if (!ret_stack_list) return -ENOMEM; + /* The cpu_boot init_task->ret_stack will never be freed */ + for_each_online_cpu(cpu) + ftrace_graph_init_task(idle_task(cpu)); + do { ret = alloc_retstack_tasklist(ret_stack_list); } while (ret == -EAGAIN); diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c index 88c8eb7..bc8e80a 100644 --- a/kernel/trace/trace_selftest.c +++ b/kernel/trace/trace_selftest.c @@ -23,10 +23,20 @@ static int trace_test_buffer_cpu(struct trace_array *tr, int cpu) { struct ring_buffer_event *event; struct trace_entry *entry; + unsigned int loops = 0; while ((event = ring_buffer_consume(tr->buffer, cpu, NULL))) { entry = ring_buffer_event_data(event); + /* + * The ring buffer is a size of trace_buf_size, if + * we loop more than the size, there's something wrong + * with the ring buffer. + */ + if (loops++ > trace_buf_size) { + printk(KERN_CONT ".. bad ring buffer "); + goto failed; + } if (!trace_valid_entry(entry)) { printk(KERN_CONT ".. invalid entry %d ", entry->type); @@ -57,11 +67,20 @@ static int trace_test_buffer(struct trace_array *tr, unsigned long *count) cnt = ring_buffer_entries(tr->buffer); + /* + * The trace_test_buffer_cpu runs a while loop to consume all data. + * If the calling tracer is broken, and is constantly filling + * the buffer, this will run forever, and hard lock the box. + * We disable the ring buffer while we do this test to prevent + * a hard lock up. + */ + tracing_off(); for_each_possible_cpu(cpu) { ret = trace_test_buffer_cpu(tr, cpu); if (ret) break; } + tracing_on(); __raw_spin_unlock(&ftrace_max_lock); local_irq_restore(flags);