When a plugin unloaded it needs to unregister its handler from pevent.
So add unregister function to do it.
Cc: Jiri Olsa <jo...@redhat.com>
Signed-off-by: Namhyung Kim <namhy...@kernel.org>
---
tools/lib/traceevent/event-parse.c | 113 ++++++++++++++++++++++++++++++++-----
tools/lib/traceevent/event-parse.h | 3 +
2 files changed, 102 insertions(+), 14 deletions(-)
diff --git a/tools/lib/traceevent/event-parse.c
b/tools/lib/traceevent/event-parse.c
index 2ce565a73dd5..05ae4b4ed0c8 100644
--- a/tools/lib/traceevent/event-parse.c
+++ b/tools/lib/traceevent/event-parse.c
@@ -5560,6 +5560,29 @@ int pevent_register_print_function(struct pevent *pevent,
return ret;
}
+static struct event_format *pevent_search_event(struct pevent *pevent, int id,
+ const char *sys_name,
+ const char *event_name)
+{
+ struct event_format *event;
+
+ if (id >= 0) {
+ /* search by id */
+ event = pevent_find_event(pevent, id);
+ if (!event)
+ return NULL;
+ if (event_name && (strcmp(event_name, event->name) != 0))
+ return NULL;
+ if (sys_name && (strcmp(sys_name, event->system) != 0))
+ return NULL;
+ } else {
+ event = pevent_find_event_by_name(pevent, sys_name, event_name);
+ if (!event)
+ return NULL;
+ }
+ return event;
+}
+
/**
* pevent_register_event_handler - register a way to parse an event
* @pevent: the handle to the pevent
@@ -5584,20 +5607,9 @@ int pevent_register_event_handler(struct pevent *pevent,
int id,
struct event_format *event;
struct event_handler *handle;
- if (id >= 0) {
- /* search by id */
- event = pevent_find_event(pevent, id);
- if (!event)
- goto not_found;
- if (event_name && (strcmp(event_name, event->name) != 0))
- goto not_found;
- if (sys_name && (strcmp(sys_name, event->system) != 0))
- goto not_found;
- } else {
- event = pevent_find_event_by_name(pevent, sys_name, event_name);
- if (!event)
- goto not_found;
- }
+ event = pevent_search_event(pevent, id, sys_name, event_name);
+ if (event == NULL)
+ goto not_found;
pr_stat("overriding event (%d) %s:%s with new print handler",
event->id, event->system, event->name);
@@ -5637,6 +5649,79 @@ int pevent_register_event_handler(struct pevent *pevent,
int id,
return -1;
}
+static int handle_matches(struct event_handler *handler, int id,
+ const char *sys_name, const char *event_name,
+ pevent_event_handler_func func, void *context)
+{
+ if (id >= 0 && id != handler->id)
+ return 0;
+
+ if (event_name && (strcmp(event_name, handler->event_name) != 0))
+ return 0;
+
+ if (sys_name && (strcmp(sys_name, handler->sys_name) != 0))
+ return 0;
+
+ if (func != handler->func || context != handler->context)
+ return 0;
+
+ return 1;
+}
+
+/**
+ * pevent_unregister_event_handler - unregister an existing event handler
+ * @pevent: the handle to the pevent
+ * @id: the id of the event to unregister
+ * @sys_name: the system name the handler belongs to
+ * @event_name: the name of the event handler
+ * @func: the function to call to parse the event information
+ * @context: the data to be passed to @func
+ *
+ * This function removes existing event handler (parser).
+ *
+ * If @id is >= 0, then it is used to find the event.
+ * else @sys_name and @event_name are used.
+ *
+ * Returns 0 if handler was removed successfully, -1 if event was not found.
+ */
+int pevent_unregister_event_handler(struct pevent *pevent, int id,
+ const char *sys_name, const char
*event_name,
+ pevent_event_handler_func func, void
*context)
+{
+ struct event_format *event;
+ struct event_handler *handle;
+ struct event_handler **next;
+
+ event = pevent_search_event(pevent, id, sys_name, event_name);
+ if (event == NULL)
+ goto not_found;
+
+ if (event->handler == func && event->context == context) {
+ pr_stat("overriding event (%d) %s:%s with default print
handler",
+ event->id, event->system, event->name);
+
+ event->handler = NULL;
+ event->context = NULL;
+ return 0;
+ }
+
+not_found:
+ for (next = &pevent->handlers; *next; next = &(*next)->next) {
+ handle = *next;
+ if (handle_matches(handle, id, sys_name, event_name,
+ func, context))
+ break;
+ }
+
+ if (!(*next))
+ return -1;
+
+ *next = handle->next;
+ free_handler(handle);
+
+ return 0;
+}
+
/**
* pevent_alloc - create a pevent handle
*/
diff --git a/tools/lib/traceevent/event-parse.h
b/tools/lib/traceevent/event-parse.h
index a3beca56cb35..c48acfbc6230 100644
--- a/tools/lib/traceevent/event-parse.h
+++ b/tools/lib/traceevent/event-parse.h
@@ -624,6 +624,9 @@ int pevent_print_func_field(struct trace_seq *s, const char
*fmt,
int pevent_register_event_handler(struct pevent *pevent, int id,
const char *sys_name, const char *event_name,
pevent_event_handler_func func, void
*context);
+int pevent_unregister_event_handler(struct pevent *pevent, int id,
+ const char *sys_name, const char
*event_name,
+ pevent_event_handler_func func, void
*context);
int pevent_register_print_function(struct pevent *pevent,
pevent_func_handler func,
enum pevent_func_arg_type ret_type,
--
1.7.11.7
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