| Subject | Re: [PATCH v6 4/7] arm64: Add ftrace support | From | Steven Rostedt <> | Date | Thu, 13 Mar 2014 14:27:39 -0400 |
| |
On Thu, 2014-03-13 at 17:08 +0000, Will Deacon wrote:
> > + /* > > + * Note: > > + * No protection against faulting at *parent, which may be seen > > + * on other archs. It's unlikely on AArch64. > > + */ > > + old = *parent; > > + *parent = return_hooker; > > return_hook? People might take it personally otherwise ;)
No, return_hooker is consistent with all the other archs. Hey, it's a rugby position! Note, which I was when I played. ;-)
> > > + trace.func = self_addr; > > in kernel/ftrace/ftrace.c there's an smb_wmb() between setting up > tracing_graph_pause and setting the ret_stack with a comment saying: > > /* Make sure the tasks see the -1 first: */ > > Why don't we have a corresponding read-barrier here?
The corresponding rmb is in kernel/trace/trace_function_graph ftrace_push_return_trace().
-- Steve
|