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

commit 4b8b3905165ef98386a3c06f196c85d21292d029 upstream.

Commit 6018b585e8c6 ("tracing/histograms: Add histograms to hist_vars if
they have referenced variables") added a check to fail histogram creation
if save_hist_vars() failed to add histogram to hist_vars list. But the
commit failed to set ret to failed return code before jumping to
unregister histogram, fix it.

Link: https://lore.kernel.org/linux-trace-kernel/20230714203341.51396-1-mkhalfella@purestorage.com
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>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 0bb34467e4f250f39941eb05ec83933be18cfe04..1b70fc4c703f7ad8e3992f2e44501ee1008bed51 100644 (file)
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -5949,7 +5949,8 @@ static int event_hist_trigger_func(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;
        }