From: "Steven Rostedt (VMware)" <rostedt@xxxxxxxxxxx>
A call to tracefs_kprobe_clear() will attempt to disable all kprobes. If
any kprobe is set, and the @force parameter is set, it will fail with
errno set to EBUSY. If @force is set, then it will attempt to disable all
the defined kprobe events and then clear it.
Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
---
include/tracefs.h | 2 +-
src/tracefs-kprobes.c | 116 ++++++++++++++++++++++++++++++++++++++++++
2 files changed, 117 insertions(+), 1 deletion(-)
diff --git a/include/tracefs.h b/include/tracefs.h
index bc504bcb0188..19b9b49d2dae 100644
--- a/include/tracefs.h
+++ b/include/tracefs.h
@@ -217,5 +217,5 @@ void tracefs_trace_pipe_stop(struct tracefs_instance *instance);
int tracefs_kprobe_raw(const char *system, const char *event,
const char *addr, const char *format);
-
+int tracefs_kprobe_clear(bool force);
#endif /* _TRACE_FS_H */
diff --git a/src/tracefs-kprobes.c b/src/tracefs-kprobes.c
index e4b28cff9f08..a6faf69fc010 100644
--- a/src/tracefs-kprobes.c
+++ b/src/tracefs-kprobes.c
@@ -68,3 +68,119 @@ int tracefs_kprobe_raw(const char *system, const char *event,
return ret < 0 ? ret : 0;
}
+
+struct instance_list {
+ struct instance_list *next;
+ struct tracefs_instance *instance;
+};
+
+static void disable_events(const char *system, const char *event,
+ char **list)
+{
+ struct tracefs_instance *instance;
+ int i;
+
+ /*
+ * Note, this will not fail even on error.
+ * That is because even if something fails, it may still
+ * work enough to clear the kprobes. If that's the case
+ * the clearing after the loop will succeed and the function
+ * is a success, even though other parts had failed. If
+ * one of the kprobe events is enabled in one of the
+ * instances that fail, then the clearing will fail too
+ * and the function will return an error.
+ */
+
+ tracefs_event_disable(NULL, system, event);
+ /* No need to test results */
+
+ if (!list)
+ return;
+
+ for (i = 0; list[i]; i++) {
+ instance = tracefs_instance_alloc(NULL, list[i]);
+ /* If this fails, try the next one */
+ if (!instance)
+ continue;
+ tracefs_event_disable(instance, system, event);
+ tracefs_instance_free(instance);
+ }
+ return;
+}
+
+/**
+ * tracefs_kprobe_clear - clear kprobe events
+ * @force: Will attempt to disable all kprobe events and clear them
+ *
+ * Will remove all defined kprobe events. If any of them are enabled,
+ * and @force is not set, then it will error with -1 and errno to be
+ * EBUSY. If @force is set, then it will attempt to disable all the kprobe
+ * events in all instances, and try again.
+ *
+ * Returns zero on success, -1 otherwise.
+ */
+int tracefs_kprobe_clear(bool force)
+{
+ char **instance_list;
+ char *content;
+ char *saveptr;
+ char *system;
+ char *event;
+ char *p;
+ int ret;
+
+ ret = tracefs_instance_file_clear(NULL, KPROBE_EVENTS);
+ if (!ret)
+ return 0;
+
+ if (!force)
+ return -1;
+
+ /* Attempt to disable all kprobe events */
+ content = tracefs_instance_file_read(NULL, KPROBE_EVENTS, NULL);
+ if (!content)
+ return -1;
+
+ instance_list = tracefs_instances(NULL);
+ /*
+ * Even if the above failed and instance_list is NULL,
+ * keep going, as the enabled event may simply be in the
+ * top level.
+ */
+
+ ret = -1;
+ p = strtok_r(content, ":", &saveptr);
+ if (!p)
+ goto out;
+
+ for (;;) {
+ p = strtok_r(NULL, "/", &saveptr);
+ if (!p)
+ goto out;
+
+ system = p;
+
+ p = strtok_r(NULL," ", &saveptr);
+ if (!p)
+ goto out;
+ event = p;
+
+ disable_events(system, event, instance_list);
+
+ ret = tracefs_instance_file_clear(NULL, KPROBE_EVENTS);
+ /* On success stop the loop */
+ if (!ret)
+ goto out;
+
+ ret = -1;
+ p = strtok_r(NULL, "\n", &saveptr);
+ if (!p)
+ goto out;
+
+ p = strtok_r(NULL, ":", &saveptr);
+ }
+ out:
+ tracefs_list_free(instance_list);
+ free(content);
+ return ret;
+}
--
2.30.2
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