From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756832Ab0IXPlK (ORCPT ); Fri, 24 Sep 2010 11:41:10 -0400 Received: from mx1.redhat.com ([209.132.183.28]:50288 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753689Ab0IXPlJ (ORCPT ); Fri, 24 Sep 2010 11:41:09 -0400 Date: Fri, 24 Sep 2010 17:41:02 +0200 From: Jiri Olsa To: Steven Rostedt Cc: fweisbec@gmail.com, linux-kernel@vger.kernel.org Subject: Re: [PATCHv2 1/3] tracing: proper check for irq_depth routines Message-ID: <20100924154102.GB1818@jolsa.brq.redhat.com> References: <1285243253-7372-1-git-send-email-jolsa@redhat.com> <1285243253-7372-2-git-send-email-jolsa@redhat.com> <1285271293.26872.1613.camel@gandalf.stny.rr.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1285271293.26872.1613.camel@gandalf.stny.rr.com> User-Agent: Mutt/1.5.20 (2009-12-10) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Sep 23, 2010 at 03:48:13PM -0400, Steven Rostedt wrote: > On Thu, 2010-09-23 at 14:00 +0200, Jiri Olsa wrote: > > The check_irq_entry and check_irq_return could be called > > from graph event context. In such case there's no graph > > private data allocated. Adding checks to handle this case. > > > > wbr, > > jirka > > > > > > Signed-off-by: Jiri Olsa > > --- > > kernel/trace/trace_functions_graph.c | 24 ++++++++++++++++++++---- > > 1 files changed, 20 insertions(+), 4 deletions(-) > > > > diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c > > index 02c708a..1390159 100644 > > --- a/kernel/trace/trace_functions_graph.c > > +++ b/kernel/trace/trace_functions_graph.c > > @@ -887,12 +887,20 @@ check_irq_entry(struct trace_iterator *iter, u32 flags, > > unsigned long addr, int depth) > > { > > int cpu = iter->cpu; > > + int *depth_irq; > > struct fgraph_data *data = iter->private; > > - int *depth_irq = &(per_cpu_ptr(data->cpu_data, cpu)->depth_irq); > > > > - if (flags & TRACE_GRAPH_PRINT_IRQS) > > + /* > > + * We either display irqs, or we got called as > > + * graph event, and out private data do no exist. > > "out private data do no exist" makes no sense. > > > + * In both cases we bypass the irq check. > > + */ > > + if ((flags & TRACE_GRAPH_PRINT_IRQS) || > > + (!data)) > > return 0; > > > > + depth_irq = &(per_cpu_ptr(data->cpu_data, cpu)->depth_irq); > > + > > /* > > * We are inside the irq code > > */ > > @@ -925,12 +933,20 @@ static int > > check_irq_return(struct trace_iterator *iter, u32 flags, int depth) > > { > > int cpu = iter->cpu; > > + int *depth_irq; > > struct fgraph_data *data = iter->private; > > - int *depth_irq = &(per_cpu_ptr(data->cpu_data, cpu)->depth_irq); > > > > - if (flags & TRACE_GRAPH_PRINT_IRQS) > > + /* > > + * We either display irqs, or we got called as > > + * graph event, and out private data do no exist. > > ditto. > > -- Steve > > > + * In both cases we bypass the irq check. > > + */ > > + if ((flags & TRACE_GRAPH_PRINT_IRQS) || > > + (!data)) > > return 0; > > > > + depth_irq = &(per_cpu_ptr(data->cpu_data, cpu)->depth_irq); > > + > > /* > > * We are not inside the irq code. > > */ > > hi, attaching changed patch thanks, jirka --- The check_irq_entry and check_irq_return could be called from graph event context. In such case there's no graph private data allocated. Adding checks to handle this case. wbr, jirka Signed-off-by: Jiri Olsa --- kernel/trace/trace_functions_graph.c | 24 ++++++++++++++++++++---- 1 files changed, 20 insertions(+), 4 deletions(-) diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c index 02c708a..1390159 100644 --- a/kernel/trace/trace_functions_graph.c +++ b/kernel/trace/trace_functions_graph.c @@ -887,12 +887,20 @@ check_irq_entry(struct trace_iterator *iter, u32 flags, unsigned long addr, int depth) { int cpu = iter->cpu; + int *depth_irq; struct fgraph_data *data = iter->private; - int *depth_irq = &(per_cpu_ptr(data->cpu_data, cpu)->depth_irq); - if (flags & TRACE_GRAPH_PRINT_IRQS) + /* + * We either display irqs, or we got called as + * graph event, and private data do no exist. + * In both cases we bypass the irq check. + */ + if ((flags & TRACE_GRAPH_PRINT_IRQS) || + (!data)) return 0; + depth_irq = &(per_cpu_ptr(data->cpu_data, cpu)->depth_irq); + /* * We are inside the irq code */ @@ -925,12 +933,20 @@ static int check_irq_return(struct trace_iterator *iter, u32 flags, int depth) { int cpu = iter->cpu; + int *depth_irq; struct fgraph_data *data = iter->private; - int *depth_irq = &(per_cpu_ptr(data->cpu_data, cpu)->depth_irq); - if (flags & TRACE_GRAPH_PRINT_IRQS) + /* + * We either display irqs, or we got called as + * graph event, and private data do no exist. + * In both cases we bypass the irq check. + */ + if ((flags & TRACE_GRAPH_PRINT_IRQS) || + (!data)) return 0; + depth_irq = &(per_cpu_ptr(data->cpu_data, cpu)->depth_irq); + /* * We are not inside the irq code. */ -- 1.7.1