Re: [PATCH] kernel/trace: Use rcu_assign_pointer() for setting fgraph hash pointers

[Steven Rostedt]

On Wed,  5 Feb 2020 17:18:08 -0500
"Joel Fernandes (Google)" <joel@xxxxxxxxxxxxxxxxx> wrote:

> set_ftrace_early_graph() sets pointers without any explicit
> release-barriers. Let us use rcu_assign_pointer() to ensure the same.
> 
> Note that ftrace_early_graph() calls ftrace_graph_set_hash() which does
> do mutex_unlock(&ftrace_lock); which should imply a release barrier.
> However it is better to not depend on it and just use
> rcu_assign_pointer() which should also avoid sparse errors in the
> future.

This is going to have to wait for the next merge window, as I'm already
*very* late, and I've pushed the limit to what I will add at this time
frame.

-- Steve