All RCU disabled code should be noinstr and hence we should never get here -- when we do, WARN about it and make sure to not actually do tracing.
Signed-off-by: Peter Zijlstra (Intel) <[email protected]> --- arch/x86/kernel/ftrace.c | 3 +++ 1 file changed, 3 insertions(+) --- a/arch/x86/kernel/ftrace.c +++ b/arch/x86/kernel/ftrace.c @@ -646,6 +646,9 @@ void prepare_ftrace_return(unsigned long if (unlikely(atomic_read(¤t->tracing_graph_pause))) return; + if (WARN_ONCE(!rcu_is_watching(), "RCU not on for: %pS\n", (void *)ip)) + return; + bit = ftrace_test_recursion_trylock(ip, *parent); if (bit < 0) return; _______________________________________________ Virtualization mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/virtualization
