From: "Steven Rostedt (VMware)" <rostedt@xxxxxxxxxxx>
Add an interface that is similar to tracefs_kprobe_raw() but creates a
"kretprobe". The difference between a kprobe and a kretprobe is that a
kretprobe comes at the end of a function.
See Documentation/trace/kprobetrace.rst in the Linux kernel source code
for more information. Note, kprobes are started with "p" and kretprobe
lines start with an "r".
Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
---
include/tracefs.h | 3 +-
src/tracefs-kprobes.c | 85 ++++++++++++++++++++++++++++++-------------
2 files changed, 61 insertions(+), 27 deletions(-)
diff --git a/include/tracefs.h b/include/tracefs.h
index bc504bcb0188..64164c8c2b20 100644
--- a/include/tracefs.h
+++ b/include/tracefs.h
@@ -217,5 +217,6 @@ 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_kretprobe_raw(const char *system, const char *event,
+ const char *addr, const char *format);
#endif /* _TRACE_FS_H */
diff --git a/src/tracefs-kprobes.c b/src/tracefs-kprobes.c
index d50191d55181..4970620b28f2 100644
--- a/src/tracefs-kprobes.c
+++ b/src/tracefs-kprobes.c
@@ -19,28 +19,9 @@
#define KPROBE_EVENTS "kprobe_events"
-/**
- * tracefs_kprobe_raw - Create a kprobe using raw format
- * @system: The system name (NULL for the default kprobes)
- * @event: The event to create (NULL to use @addr for the event)
- * @addr: The function and offset (or address) to insert the probe
- * @format: The raw format string to define the probe.
- *
- * Create a kprobe that will be in the @system group (or kprobes if
- * @system is NULL). Have the name of @event (or @addr if @event is
- * NULL). Will be inserted to @addr (function name, with or without
- * offset, or a address). And the @format will define the raw format
- * of the kprobe. See the Linux documentation file under:
- * Documentation/trace/kprobetrace.rst
- *
- * Return 0 on success, or -1 on error.
- * If the syntex of @format was incorrect, running
- * tracefs_error_last(NULL) may show what went wrong.
- *
- * errno will be set to EBADMSG if addr or format is NULL.
- */
-int tracefs_kprobe_raw(const char *system, const char *event,
- const char *addr, const char *format)
+static int insert_kprobe(const char *type, const char *system,
+ const char *event, const char *addr,
+ const char *format)
{
char *str;
int ret;
@@ -56,11 +37,11 @@ int tracefs_kprobe_raw(const char *system, const char *event,
event = addr;
if (system)
- ret = asprintf(&str, "p:%s/%s %s %s\n",
- system, event, addr, format);
+ ret = asprintf(&str, "%s:%s/%s %s %s\n",
+ type, system, event, addr, format);
else
- ret = asprintf(&str, "p:%s %s %s\n",
- event, addr, format);
+ ret = asprintf(&str, "%s:%s %s %s\n",
+ type, event, addr, format);
if (ret < 0)
return -1;
@@ -70,3 +51,55 @@ int tracefs_kprobe_raw(const char *system, const char *event,
return ret < 0 ? ret : 0;
}
+
+/**
+ * tracefs_kprobe_raw - Create a kprobe using raw format
+ * @system: The system name (NULL for the default kprobes)
+ * @event: The event to create (NULL to use @addr for the event)
+ * @addr: The function and offset (or address) to insert the probe
+ * @format: The raw format string to define the probe.
+ *
+ * Create a kprobe that will be in the @system group (or kprobes if
+ * @system is NULL). Have the name of @event (or @addr if @event is
+ * NULL). Will be inserted to @addr (function name, with or without
+ * offset, or a address). And the @format will define the raw format
+ * of the kprobe. See the Linux documentation file under:
+ * Documentation/trace/kprobetrace.rst
+ *
+ * Return 0 on success, or -1 on error.
+ * If the syntex of @format was incorrect, running
+ * tracefs_error_last(NULL) may show what went wrong.
+ *
+ * errno will be set to EBADMSG if addr or format is NULL.
+ */
+int tracefs_kprobe_raw(const char *system, const char *event,
+ const char *addr, const char *format)
+{
+ return insert_kprobe("p", system, event, addr, format);
+}
+
+/**
+ * tracefs_kretprobe_raw - Create a kretprobe using raw format
+ * @system: The system name (NULL for the default kprobes)
+ * @event: The event to create (NULL to use @addr for the event)
+ * @addr: The function and offset (or address) to insert the retprobe
+ * @format: The raw format string to define the retprobe.
+ *
+ * Create a kretprobe that will be in the @system group (or kprobes if
+ * @system is NULL). Have the name of @event (or @addr if @event is
+ * NULL). Will be inserted to @addr (function name, with or without
+ * offset, or a address). And the @format will define the raw format
+ * of the kprobe. See the Linux documentation file under:
+ * Documentation/trace/kprobetrace.rst
+ *
+ * Return 0 on success, or -1 on error.
+ * If the syntex of @format was incorrect, running
+ * tracefs_error_last(NULL) may show what went wrong.
+ *
+ * errno will be set to EBADMSG if addr or format is NULL.
+ */
+int tracefs_kretprobe_raw(const char *system, const char *event,
+ const char *addr, const char *format)
+{
+ return insert_kprobe("r", system, event, addr, format);
+}
--
2.30.2
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