From: "Steven Rostedt (VMware)" <rostedt@xxxxxxxxxxx>
Add the function tracefs_get_kprobes() that returns a list of kprobes that
are registered. The list contains strings that are of the format
"group/event" (i.e. "kprobes/open"). The last element in the list is a
NULL pointer. In the case that there are no kprobes, the list will return
a single entry of a NULL pointer.
tracefs_get_kprobes() takes a type parameter to determine which kprobes to
return:
TRACEFS_ALL_KPROBES - return all that are found
TRACEFS_KPROBE - return only normal kprobes ("p:")
TRACEFS_KRETPROBE - return only kretprobes ("r:")
NULL is returned in the case of error (mainly a memory issue, or bad
parsing).
Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
---
include/tracefs.h | 7 ++++
src/tracefs-kprobes.c | 93 +++++++++++++++++++++++++++++++++++++++++++
2 files changed, 100 insertions(+)
diff --git a/include/tracefs.h b/include/tracefs.h
index 64164c8c2b20..e8a2008d9714 100644
--- a/include/tracefs.h
+++ b/include/tracefs.h
@@ -215,8 +215,15 @@ ssize_t tracefs_trace_pipe_stream(int fd, struct tracefs_instance *instance, int
ssize_t tracefs_trace_pipe_print(struct tracefs_instance *instance, int flags);
void tracefs_trace_pipe_stop(struct tracefs_instance *instance);
+enum tracefs_kprobe_type {
+ TRACEFS_ALL_KPROBES,
+ TRACEFS_KPROBE,
+ TRACEFS_KRETPROBE,
+};
+
int tracefs_kprobe_raw(const char *system, const char *event,
const char *addr, const char *format);
int tracefs_kretprobe_raw(const char *system, const char *event,
const char *addr, const char *format);
+char **tracefs_get_kprobes(enum tracefs_kprobe_type type);
#endif /* _TRACE_FS_H */
diff --git a/src/tracefs-kprobes.c b/src/tracefs-kprobes.c
index 4970620b28f2..3bba3683f29b 100644
--- a/src/tracefs-kprobes.c
+++ b/src/tracefs-kprobes.c
@@ -103,3 +103,96 @@ int tracefs_kretprobe_raw(const char *system, const char *event,
{
return insert_kprobe("r", system, event, addr, format);
}
+
+/**
+ * tracefs_get_kprobes - return a list kprobes (by group/event name)
+ * @type: The type of kprobes to return.
+ *
+ * If @type is TRACEFS_ALL_KPROBES all kprobes in the kprobe_events
+ * are returned. Otherwise if it is TRACEFS_KPROBE, then only
+ * normal kprobes (p:) are returned, or if type is TRACEFS_KRETPROBE
+ * then only kretprobes (r:) are returned.
+ *
+ * Returns a list of strings that contain the kprobes that exist
+ * in the kprobe_events files. The strings returned are in the
+ * "group/event" format.
+ * The list must be freed with tracefs_list_free().
+ * If there are no kprobes, a list is still returned, but it contains
+ * only a NULL pointer.
+ * On error, NULL is returned.
+ */
+char **tracefs_get_kprobes(enum tracefs_kprobe_type type)
+{
+ char **list = NULL;
+ char *content;
+ char *saveptr;
+ char *event;
+ char *p;
+ int cnt = 0;
+
+ errno = 0;
+ content = tracefs_instance_file_read(NULL, KPROBE_EVENTS, NULL);
+ if (!content) {
+ if (errno)
+ return NULL;
+ /* content is NULL on empty file, return an empty list */
+ list = calloc(1, sizeof(*list));
+ return list;
+ }
+
+ p = strtok_r(content, ":", &saveptr);
+
+ while (p) {
+ char **tmp;
+
+ if (type != TRACEFS_ALL_KPROBES) {
+ switch (*p) {
+ case 'p':
+ if (type != TRACEFS_KPROBE)
+ goto next;
+ break;
+ case 'r':
+ if (type != TRACEFS_KRETPROBE)
+ goto next;
+ break;
+ default:
+ goto next;
+ }
+ }
+
+ /* Failed parsing always return a failure */
+ p = strtok_r(NULL, " ", &saveptr);
+ if (!p)
+ break;
+
+ event = strdup(p);
+ if (!event)
+ goto fail;
+
+ tmp = realloc(list, sizeof(*list) * (cnt + 2));
+ if (!tmp)
+ goto fail;
+
+ list = tmp;
+ list[cnt++] = event;
+ list[cnt] = NULL;
+ next:
+ p = strtok_r(NULL, "\n", &saveptr);
+ /* Could be end of content */
+ if (!p)
+ break;
+
+ /* p is NULL on end of content */
+ p = strtok_r(NULL, ":", &saveptr);
+ }
+
+ if (!list)
+ list = calloc(1, sizeof(*list));
+ out:
+ free(content);
+ return list;
+ fail:
+ free(list);
+ list = NULL;
+ goto out;
+}
--
2.30.2
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