Merge tag 'trace-v4.17-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt...

[linux-block.git] / kernel / trace / trace_uprobe.c

diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index 21604754bb79eafa293845fe2475175f5bb57351..469ba7ecd14be1cb2d9b4964cd5dc9abb38b4093 100644 (file)
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -1277,16 +1277,25 @@ static struct trace_event_functions uprobe_funcs = {
        .trace          = print_uprobe_event
 };
 
-static int register_uprobe_event(struct trace_uprobe *tu)
+static inline void init_trace_event_call(struct trace_uprobe *tu,
+                                        struct trace_event_call *call)
 {
-       struct trace_event_call *call = &tu->tp.call;
-       int ret;
-
-       /* Initialize trace_event_call */
        INIT_LIST_HEAD(&call->class->fields);
        call->event.funcs = &uprobe_funcs;
        call->class->define_fields = uprobe_event_define_fields;
 
+       call->flags = TRACE_EVENT_FL_UPROBE;
+       call->class->reg = trace_uprobe_register;
+       call->data = tu;
+}
+
+static int register_uprobe_event(struct trace_uprobe *tu)
+{
+       struct trace_event_call *call = &tu->tp.call;
+       int ret = 0;
+
+       init_trace_event_call(tu, call);
+
        if (set_print_fmt(&tu->tp, is_ret_probe(tu)) < 0)
                return -ENOMEM;
 
@@ -1296,9 +1305,6 @@ static int register_uprobe_event(struct trace_uprobe *tu)
                return -ENODEV;
        }
 
-       call->flags = TRACE_EVENT_FL_UPROBE;
-       call->class->reg = trace_uprobe_register;
-       call->data = tu;
        ret = trace_add_event_call(call);
 
        if (ret) {
@@ -1324,6 +1330,70 @@ static int unregister_uprobe_event(struct trace_uprobe *tu)
        return 0;
 }
 
+#ifdef CONFIG_PERF_EVENTS
+struct trace_event_call *
+create_local_trace_uprobe(char *name, unsigned long offs, bool is_return)
+{
+       struct trace_uprobe *tu;
+       struct inode *inode;
+       struct path path;
+       int ret;
+
+       ret = kern_path(name, LOOKUP_FOLLOW, &path);
+       if (ret)
+               return ERR_PTR(ret);
+
+       inode = igrab(d_inode(path.dentry));
+       path_put(&path);
+
+       if (!inode || !S_ISREG(inode->i_mode)) {
+               iput(inode);
+               return ERR_PTR(-EINVAL);
+       }
+
+       /*
+        * local trace_kprobes are not added to probe_list, so they are never
+        * searched in find_trace_kprobe(). Therefore, there is no concern of
+        * duplicated name "DUMMY_EVENT" here.
+        */
+       tu = alloc_trace_uprobe(UPROBE_EVENT_SYSTEM, "DUMMY_EVENT", 0,
+                               is_return);
+
+       if (IS_ERR(tu)) {
+               pr_info("Failed to allocate trace_uprobe.(%d)\n",
+                       (int)PTR_ERR(tu));
+               return ERR_CAST(tu);
+       }
+
+       tu->offset = offs;
+       tu->inode = inode;
+       tu->filename = kstrdup(name, GFP_KERNEL);
+       init_trace_event_call(tu, &tu->tp.call);
+
+       if (set_print_fmt(&tu->tp, is_ret_probe(tu)) < 0) {
+               ret = -ENOMEM;
+               goto error;
+       }
+
+       return &tu->tp.call;
+error:
+       free_trace_uprobe(tu);
+       return ERR_PTR(ret);
+}
+
+void destroy_local_trace_uprobe(struct trace_event_call *event_call)
+{
+       struct trace_uprobe *tu;
+
+       tu = container_of(event_call, struct trace_uprobe, tp.call);
+
+       kfree(tu->tp.call.print_fmt);
+       tu->tp.call.print_fmt = NULL;
+
+       free_trace_uprobe(tu);
+}
+#endif /* CONFIG_PERF_EVENTS */
+
 /* Make a trace interface for controling probe points */
 static __init int init_uprobe_trace(void)
 {