I'm currently running this through my test suite, but wanted to get review or acks, so that I can send this right off to Linus before rc2. I need these to base my new work on.
Basically if a stack trace happens (say from a WARN()) when RCU is not watching (like going to or coming from idle, or bringing down or up a CPU), the stack trace can cause RCU issues because it requires RCU to be watching. We use rcu_nmi_enter() for this case, as these cases behave similar to an NMI (can happen pretty much anywhere). Paul E. McKenney (1): rcu: Allow for page faults in NMI handlers Steven Rostedt (VMware) (3): extable: Consolidate *kernel_text_address() functions extable: Enable RCU if it is not watching in kernel_text_address() tracing: Remove RCU work arounds from stack tracer ---- kernel/extable.c | 45 +++++++++++++++++++++++++++++++-------------- kernel/rcu/tree.c | 10 ++++++++++ kernel/trace/trace_stack.c | 15 --------------- 3 files changed, 41 insertions(+), 29 deletions(-)