tracing/kprobe: bpf: Check error injectable event is on function entry
Check whether error injectable event is on function entry or not.
Currently it checks the event is ftrace-based kprobes or not,
but that is wrong. It should check if the event is on the entry
of target function. Since error injection will override a function
to just return with modified return value, that operation must
be done before the target function starts making stackframe.
As a side effect, bpf error injection is no need to depend on
function-tracer. It can work with sw-breakpoint based kprobe
events too.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 91f4b57..3c8deb9 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -88,13 +88,16 @@ static nokprobe_inline unsigned long trace_kprobe_nhit(struct trace_kprobe *tk)
return nhit;
}
-int trace_kprobe_ftrace(struct trace_event_call *call)
+bool trace_kprobe_on_func_entry(struct trace_event_call *call)
{
struct trace_kprobe *tk = (struct trace_kprobe *)call->data;
- return kprobe_ftrace(&tk->rp.kp);
+
+ return kprobe_on_func_entry(tk->rp.kp.addr,
+ tk->rp.kp.addr ? NULL : tk->rp.kp.symbol_name,
+ tk->rp.kp.addr ? 0 : tk->rp.kp.offset);
}
-int trace_kprobe_error_injectable(struct trace_event_call *call)
+bool trace_kprobe_error_injectable(struct trace_event_call *call)
{
struct trace_kprobe *tk = (struct trace_kprobe *)call->data;
unsigned long addr;
