[PATCH] tracing/histograms: Return an error if we fail to add histogram to hist_vars list

[PATCH] tracing/histograms: Return an error if we fail to add histogram to hist_vars list

[Mohamed Khalfella]

If the code fails to add histogram to hist_vars list, then ret should
contain error code before jumping to unregister histogram.

Cc: stable@vger.kernel.org
Fixes: 6018b585e8c6 ("tracing/histograms: Add histograms to hist_vars if they have referenced variables")
Signed-off-by: Mohamed Khalfella <mkhalfella@purestorage.com>
---
 kernel/trace/trace_events_hist.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index c8c61381eba4..d06938ae0717 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -6668,7 +6668,8 @@ static int event_hist_trigger_parse(struct event_command *cmd_ops,
 		goto out_unreg;
 
 	if (has_hist_vars(hist_data) || hist_data->n_var_refs) {
-		if (save_hist_vars(hist_data))
+		ret = save_hist_vars(hist_data);
+		if (ret)
 			goto out_unreg;
 	}
 
-- 
2.34.1

Re: [PATCH] tracing/histograms: Return an error if we fail to add histogram to hist_vars list

[Steven Rostedt]

On Fri, 14 Jul 2023 19:21:43 +0000
Mohamed Khalfella <mkhalfella@purestorage.com> wrote:

> If the code fails to add histogram to hist_vars list, then ret should
> contain error code before jumping to unregister histogram.

Thanks, but I think I'm going to hold off till rc2 to push this through, to
see what else comes in, before I go back into running tests just to get
another fix as I send my pull request to Linus! ;-)

-- Steve


> 
> Cc: stable@vger.kernel.org
> Fixes: 6018b585e8c6 ("tracing/histograms: Add histograms to hist_vars if
> they have referenced variables") Signed-off-by: Mohamed Khalfella
> <mkhalfella@purestorage.com> ---
>  kernel/trace/trace_events_hist.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/kernel/trace/trace_events_hist.c
> b/kernel/trace/trace_events_hist.c index c8c61381eba4..d06938ae0717 100644
> --- a/kernel/trace/trace_events_hist.c
> +++ b/kernel/trace/trace_events_hist.c
> @@ -6668,7 +6668,8 @@ static int event_hist_trigger_parse(struct
> event_command *cmd_ops, goto out_unreg;
>  
>  	if (has_hist_vars(hist_data) || hist_data->n_var_refs) {
> -		if (save_hist_vars(hist_data))
> +		ret = save_hist_vars(hist_data);
> +		if (ret)
>  			goto out_unreg;
>  	}
>