On Sat, Aug 31, 2013 at 01:11:21AM -0400, Steven Rostedt wrote: > From: "Steven Rostedt (Red Hat)" <rost...@goodmis.org> > > When more than one ftrace_ops is registered, the list function is > is used to call all registered functions. It uses the filter and > notrace hashes from the ftrace_ops to determine if the corresponding > callback should be called or not. > > Currently, it does not take into account for RCU unsafe functions. > If multiple functions are registered, and an RCU safe callback is > used on a RCU unsafe function, and the RCU unsafe callback says to > trace all functions, it will end up tracing this RCU unsafe function > and still suffer the problems when using RCU when RCU tracing is > off. > > Add a test to the multiple ops list function to test if the ops in > question can use an RCU unsafe function or not, and if the function > being traced happens to be an RCU unsafe function. > > Cc: Jiri Olsa <jo...@redhat.com> > Cc: Paul E. McKenney <paul...@linux.vnet.ibm.com> > Signed-off-by: Steven Rostedt <rost...@goodmis.org>
Acked-by: Paul E. McKenney <paul...@linux.vnet.ibm.com> > --- > kernel/trace/ftrace.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c > index a45deaa..06504b2 100644 > --- a/kernel/trace/ftrace.c > +++ b/kernel/trace/ftrace.c > @@ -1480,7 +1480,9 @@ ftrace_ops_test(struct ftrace_ops *ops, unsigned long > ip, void *regs) > if ((ftrace_hash_empty(filter_hash) || > ftrace_lookup_ip(filter_hash, ip)) && > (ftrace_hash_empty(notrace_hash) || > - !ftrace_lookup_ip(notrace_hash, ip))) > + !ftrace_lookup_ip(notrace_hash, ip)) && > + (ops->flags & FTRACE_OPS_FL_RCU_SAFE || > + !ftrace_lookup_ip(ftrace_unsafe_rcu, ip))) > ret = 1; > else > ret = 0; > -- > 1.7.10.4 > > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
