In this patchset, I introduce a new macro TRACE_EVENT_NONE(), which will
define a tracepoint as a do-nothing inline function.
#define TRACE_EVENT_NONE(name, proto) \
static inline void trace_##name(proto) \
{ } \
static inline bool trace_##name##_enabled(void) \
{ \
return false; \
}
Let's take some example for why this macro is needed.
- sched
The tracepoints trace_sched_stat_{iowait, blocked, wait, sleep} should
be not exposed to user if CONFIG_SCHEDSTATS is not set.
We can place #ifdef in the kernel/sched/fair.c to fix it, but we don't want
to sprinkle #ifdef.
So with TRACE_EVENT_NONE(), we can fix it in include/trace/events/sched.h.
- rcu
When CONFIG_RCU_TRACE is not set, some rcu tracepoints are define as
do-nothing macro without validating arguments, that is not proper.
We should validate the arguments.
Yafang Shao (3):
tracing: introduce TRACE_EVENT_NONE()
sched/fair: do not expose some tracepoints to user if
CONFIG_SCHEDSTATS is not set
rcu: validate arguments for rcu tracepoints
include/linux/tracepoint.h | 8 +++++
include/trace/define_trace.h | 4 +++
include/trace/events/rcu.h | 84 ++++++++++++++++++++++++++++----------------
include/trace/events/sched.h | 14 ++++++++
kernel/rcu/rcu.h | 9 ++---
kernel/rcu/tree.c | 8 ++---
6 files changed, 86 insertions(+), 41 deletions(-)
--
1.8.3.1
