On Fri, Feb 07, 2020 at 08:28:42AM -0500, Steven Rostedt wrote:
Hi Greg,
On Fri, 07 Feb 2020 11:16:16 +0100
<gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 8c52f5de9384..3c75d29bd861 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -979,6 +979,7 @@ static inline int ftrace_graph_addr(struct ftrace_graph_ent *trace)
* Have to open code "rcu_dereference_sched()" because the
* function graph tracer can be called when RCU is not
* "watching".
+ * Protected with schedule_on_each_cpu(ftrace_sync)
*/
hash = rcu_dereference_protected(ftrace_graph_hash, !preemptible());
@@ -1031,6 +1032,7 @@ static inline int ftrace_graph_notrace_addr(unsigned long addr)
* Have to open code "rcu_dereference_sched()" because the
* function graph tracer can be called when RCU is not
* "watching".
+ * Protected with schedule_on_each_cpu(ftrace_sync)
*/
notrace_hash = rcu_dereference_protected(ftrace_graph_notrace_hash,
!preemptible());
Ah, I updated that patch to insert these comments, which makes it
dependent on 16052dd5bdfa ("ftrace: Add comment to why
rcu_dereference_sched() is open coded"). This is just adding comments
and should have a very lower risk of breaking anything. If you add that
patch first, then this patch should apply cleanly. Would it be OK to
add that comment patch? It should fix most the conflicts.
I've ended up taking these additional commits, and queued everything for
5.5-4.14:
16052dd5bdfa ("ftrace: Add comment to why rcu_dereference_sched() is open coded")
24a9729f8314 ("tracing: Annotate ftrace_graph_hash pointer with __rcu")
fd0e6852c407 ("tracing: Annotate ftrace_graph_notrace_hash pointer with __rcu")
--
Thanks,
Sasha
