4.19-stable review patch. If anyone has any objections, please let me know.
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From: Masami Hiramatsu mhiramat@kernel.org
commit faacb361f271be4baf2d807e2eeaba87e059225f upstream.
Since the event_mutex and synth_event_mutex ordering issue is gone, we can skip existing event check when adding or deleting events, and some redundant code in error path.
This changes release_all_synth_events() to abort the process when it hits any error and returns the error code. It succeeds only if it has no error.
Link: http://lkml.kernel.org/r/154140847194.17322.17960275728005067803.stgit@devbo...
Reviewed-by: Tom Zanussi tom.zanussi@linux.intel.com Tested-by: Tom Zanussi tom.zanussi@linux.intel.com Signed-off-by: Masami Hiramatsu mhiramat@kernel.org Signed-off-by: Steven Rostedt (VMware) rostedt@goodmis.org Signed-off-by: George Guo guodongtai@kylinos.cn Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- kernel/trace/trace_events_hist.c | 53 +++++++++++++-------------------------- 1 file changed, 18 insertions(+), 35 deletions(-)
--- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -1028,18 +1028,6 @@ struct hist_var_data { struct hist_trigger_data *hist_data; };
-static void add_or_delete_synth_event(struct synth_event *event, int delete) -{ - if (delete) - free_synth_event(event); - else { - if (!find_synth_event(event->name)) - list_add(&event->list, &synth_event_list); - else - free_synth_event(event); - } -} - static int create_synth_event(int argc, char **argv) { struct synth_field *field, *fields[SYNTH_FIELDS_MAX]; @@ -1072,15 +1060,16 @@ static int create_synth_event(int argc, if (event) { if (delete_event) { if (event->ref) { - event = NULL; ret = -EBUSY; goto out; } - list_del(&event->list); - goto out; - } - event = NULL; - ret = -EEXIST; + ret = unregister_synth_event(event); + if (!ret) { + list_del(&event->list); + free_synth_event(event); + } + } else + ret = -EEXIST; goto out; } else if (delete_event) { ret = -ENOENT; @@ -1120,29 +1109,21 @@ static int create_synth_event(int argc, event = NULL; goto err; } + ret = register_synth_event(event); + if (!ret) + list_add(&event->list, &synth_event_list); + else + free_synth_event(event); out: - if (event) { - if (delete_event) { - ret = unregister_synth_event(event); - add_or_delete_synth_event(event, !ret); - } else { - ret = register_synth_event(event); - add_or_delete_synth_event(event, ret); - } - } mutex_unlock(&synth_event_mutex); mutex_unlock(&event_mutex);
return ret; err: - mutex_unlock(&synth_event_mutex); - mutex_unlock(&event_mutex); - for (i = 0; i < n_fields; i++) free_synth_field(fields[i]); - free_synth_event(event);
- return ret; + goto out; }
static int release_all_synth_events(void) @@ -1161,10 +1142,12 @@ static int release_all_synth_events(void }
list_for_each_entry_safe(event, e, &synth_event_list, list) { - list_del(&event->list); - ret = unregister_synth_event(event); - add_or_delete_synth_event(event, !ret); + if (!ret) { + list_del(&event->list); + free_synth_event(event); + } else + break; } mutex_unlock(&synth_event_mutex); mutex_unlock(&event_mutex);