[PATCH] tracing: add checks for printing graph irq

[PATCH] tracing: add checks for printing graph irq

[Wenji Huang]

Check return value of trace_seq_printf.

Signed-off-by: Wenji Huang <wenji.huang@oracle.com>
---
 kernel/trace/trace_functions_graph.c |    7 +++++--
 1 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
index 45e6c01..3fa4055 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -555,8 +555,11 @@ print_graph_irq(struct trace_iterator *iter, unsigned long addr,
 		return TRACE_TYPE_PARTIAL_LINE;
 
 	/* Don't close the duration column if haven't one */
-	if (tracer_flags.val & TRACE_GRAPH_PRINT_DURATION)
-		trace_seq_printf(s, " |");
+	if (tracer_flags.val & TRACE_GRAPH_PRINT_DURATION) {
+		ret = trace_seq_printf(s, " |");
+		if (!ret)
+			return TRACE_TYPE_PARTIAL_LINE;
+	}
 	ret = trace_seq_printf(s, "\n");
 
 	if (!ret)
-- 
1.5.6

Re: [PATCH] tracing: add checks for printing graph irq

[Frederic Weisbecker]

On Fri, Dec 11, 2009 at 05:38:35PM +0800, Wenji Huang wrote:
> Check return value of trace_seq_printf.
> 
> Signed-off-by: Wenji Huang <wenji.huang@oracle.com>
> ---


Thanks.

Acked-by: Frederic Weisbecker <fweisbec@gmail.com>

Re: [PATCH] tracing: add checks for printing graph irq

[Frederic Weisbecker]

On Fri, Dec 11, 2009 at 05:38:35PM +0800, Wenji Huang wrote:
> Check return value of trace_seq_printf.
> 
> Signed-off-by: Wenji Huang <wenji.huang@oracle.com>
> ---


I'm applying it, I'll send the fix for the problem you've reported
at the same time.

Thanks.

Re: [PATCH] tracing: add checks for printing graph irq

[Steven Rostedt]

On Fri, 2009-12-11 at 12:19 +0100, Frederic Weisbecker wrote:
> On Fri, Dec 11, 2009 at 05:38:35PM +0800, Wenji Huang wrote:
> > Check return value of trace_seq_printf.
> > 
> > Signed-off-by: Wenji Huang <wenji.huang@oracle.com>
> > ---
> 
> 
> I'm applying it, I'll send the fix for the problem you've reported
> at the same time.

As for my comment to the patch. Please do not apply this.

Thanks,

-- Steve

Re: [PATCH] tracing: add checks for printing graph irq

[Frederic Weisbecker]

On Fri, Dec 11, 2009 at 10:00:50AM -0500, Steven Rostedt wrote:
> On Fri, 2009-12-11 at 12:19 +0100, Frederic Weisbecker wrote:
> > On Fri, Dec 11, 2009 at 05:38:35PM +0800, Wenji Huang wrote:
> > > Check return value of trace_seq_printf.
> > > 
> > > Signed-off-by: Wenji Huang <wenji.huang@oracle.com>
> > > ---
> > 
> > 
> > I'm applying it, I'll send the fix for the problem you've reported
> > at the same time.
> 
> As for my comment to the patch. Please do not apply this.
> 
> Thanks,


Ok. Yeah you're right, the seq buffer will refuse them once
it's fullfilled anyway, so only the last check matters, we have
too much of these checks in the current code.

Re: [PATCH] tracing: add checks for printing graph irq

[Steven Rostedt]

On Fri, 2009-12-11 at 17:38 +0800, Wenji Huang wrote:
> Check return value of trace_seq_printf.
> 
> Signed-off-by: Wenji Huang <wenji.huang@oracle.com>
> ---
>  kernel/trace/trace_functions_graph.c |    7 +++++--
>  1 files changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
> index 45e6c01..3fa4055 100644
> --- a/kernel/trace/trace_functions_graph.c
> +++ b/kernel/trace/trace_functions_graph.c
> @@ -555,8 +555,11 @@ print_graph_irq(struct trace_iterator *iter, unsigned long addr,
>  		return TRACE_TYPE_PARTIAL_LINE;
>  
>  	/* Don't close the duration column if haven't one */
> -	if (tracer_flags.val & TRACE_GRAPH_PRINT_DURATION)
> -		trace_seq_printf(s, " |");
> +	if (tracer_flags.val & TRACE_GRAPH_PRINT_DURATION) {
> +		ret = trace_seq_printf(s, " |");
> +		if (!ret)
> +			return TRACE_TYPE_PARTIAL_LINE;
> +	}
>  	ret = trace_seq_printf(s, "\n");

Actually these checks are no longer needed. I would like to start
removing them. Only the last one is needed.

This is because trace_seq_* now has a "full" attribute. If the s buffer
gets full, it wont write anymore, and all new "trace_seq_*" calls will
return the same.

-- Steve

>  
>  	if (!ret)