[for-next][PATCH 19/19] rcu: validate arguments for rcu tracepoints

Steven Rostedt
2019-04-04T01:37:59Z

From: Yafang Shao <laoar.shao@gmail.com>

When CONFIG_RCU_TRACE is not set, all these tracepoints are defined as
do-nothing macro.
We'd better make those inline functions that take proper arguments.

As RCU_TRACE() is defined as do-nothing marco as well when
CONFIG_RCU_TRACE is not set, so we can clean it up.

Link: http://lkml.kernel.org/r/1553602391-11926-4-git-send-email-laoar.shao@gmail.com

Reviewed-by: Paul E. McKenney <paulmck@linux.ibm.com>
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
include/trace/events/rcu.h | 81 ++++++++++++--------------------------
kernel/rcu/rcu.h | 9 +----
kernel/rcu/tree.c | 8 ++--
3 files changed, 31 insertions(+), 67 deletions(-)

diff --git a/include/trace/events/rcu.h b/include/trace/events/rcu.h
index f0c4d10e614b..e3f357b89432 100644
--- a/include/trace/events/rcu.h
+++ b/include/trace/events/rcu.h
@@ -7,6 +7,12 @@

#include <linux/tracepoint.h>

+#ifdef CONFIG_RCU_TRACE
+#define TRACE_EVENT_RCU TRACE_EVENT
+#else
+#define TRACE_EVENT_RCU TRACE_EVENT_NOP
+#endif
+
/*
* Tracepoint for start/end markers used for utilization calculations.
* By convention, the string is of the following forms:
@@ -35,8 +41,6 @@ TRACE_EVENT(rcu_utilization,
TP_printk("%s", __entry->s)
);

-#ifdef CONFIG_RCU_TRACE
-
#if defined(CONFIG_TREE_RCU) || defined(CONFIG_PREEMPT_RCU)

/*
@@ -62,7 +66,7 @@ TRACE_EVENT(rcu_utilization,
* "end": End a grace period.
* "cpuend": CPU first notices a grace-period end.
*/
-TRACE_EVENT(rcu_grace_period,
+TRACE_EVENT_RCU(rcu_grace_period,

TP_PROTO(const char *rcuname, unsigned long gp_seq, const char *gpevent),

@@ -101,7 +105,7 @@ TRACE_EVENT(rcu_grace_period,
* "Cleanup": Clean up rcu_node structure after previous GP.
* "CleanupMore": Clean up, and another GP is needed.
*/
-TRACE_EVENT(rcu_future_grace_period,
+TRACE_EVENT_RCU(rcu_future_grace_period,

TP_PROTO(const char *rcuname, unsigned long gp_seq,
unsigned long gp_seq_req, u8 level, int grplo, int grphi,
@@ -141,7 +145,7 @@ TRACE_EVENT(rcu_future_grace_period,
* rcu_node structure, and the mask of CPUs that will be waited for.
* All but the type of RCU are extracted from the rcu_node structure.
*/
-TRACE_EVENT(rcu_grace_period_init,
+TRACE_EVENT_RCU(rcu_grace_period_init,

TP_PROTO(const char *rcuname, unsigned long gp_seq, u8 level,
int grplo, int grphi, unsigned long qsmask),
@@ -186,7 +190,7 @@ TRACE_EVENT(rcu_grace_period_init,
* "endwake": Woke piggybackers up.
* "done": Someone else did the expedited grace period for us.
*/
-TRACE_EVENT(rcu_exp_grace_period,
+TRACE_EVENT_RCU(rcu_exp_grace_period,

TP_PROTO(const char *rcuname, unsigned long gpseq, const char *gpevent),

@@ -218,7 +222,7 @@ TRACE_EVENT(rcu_exp_grace_period,
* "nxtlvl": Advance to next level of rcu_node funnel
* "wait": Wait for someone else to do expedited GP
*/
-TRACE_EVENT(rcu_exp_funnel_lock,
+TRACE_EVENT_RCU(rcu_exp_funnel_lock,

TP_PROTO(const char *rcuname, u8 level, int grplo, int grphi,
const char *gpevent),
@@ -269,7 +273,7 @@ TRACE_EVENT(rcu_exp_funnel_lock,
* "WaitQueue": Enqueue partially done, timed wait for it to complete.
* "WokeQueue": Partial enqueue now complete.
*/
-TRACE_EVENT(rcu_nocb_wake,
+TRACE_EVENT_RCU(rcu_nocb_wake,

TP_PROTO(const char *rcuname, int cpu, const char *reason),

@@ -297,7 +301,7 @@ TRACE_EVENT(rcu_nocb_wake,
* include SRCU), the grace-period number that the task is blocking
* (the current or the next), and the task's PID.
*/
-TRACE_EVENT(rcu_preempt_task,
+TRACE_EVENT_RCU(rcu_preempt_task,

TP_PROTO(const char *rcuname, int pid, unsigned long gp_seq),

@@ -324,7 +328,7 @@ TRACE_EVENT(rcu_preempt_task,
* read-side critical section exiting that critical section. Track the
* type of RCU (which one day might include SRCU) and the task's PID.
*/
-TRACE_EVENT(rcu_unlock_preempted_task,
+TRACE_EVENT_RCU(rcu_unlock_preempted_task,

TP_PROTO(const char *rcuname, unsigned long gp_seq, int pid),

@@ -353,7 +357,7 @@ TRACE_EVENT(rcu_unlock_preempted_task,
* whether there are any blocked tasks blocking the current grace period.
* All but the type of RCU are extracted from the rcu_node structure.
*/
-TRACE_EVENT(rcu_quiescent_state_report,
+TRACE_EVENT_RCU(rcu_quiescent_state_report,

TP_PROTO(const char *rcuname, unsigned long gp_seq,
unsigned long mask, unsigned long qsmask,
@@ -396,7 +400,7 @@ TRACE_EVENT(rcu_quiescent_state_report,
* state, which can be "dti" for dyntick-idle mode or "kick" when kicking
* a CPU that has been in dyntick-idle mode for too long.
*/
-TRACE_EVENT(rcu_fqs,
+TRACE_EVENT_RCU(rcu_fqs,

TP_PROTO(const char *rcuname, unsigned long gp_seq, int cpu, const char *qsevent),

@@ -436,7 +440,7 @@ TRACE_EVENT(rcu_fqs,
* events use two separate counters, and that the "++=" and "--=" events
* for irq/NMI will change the counter by two, otherwise by one.
*/
-TRACE_EVENT(rcu_dyntick,
+TRACE_EVENT_RCU(rcu_dyntick,

TP_PROTO(const char *polarity, long oldnesting, long newnesting, atomic_t dynticks),

@@ -468,7 +472,7 @@ TRACE_EVENT(rcu_dyntick,
* number of lazy callbacks queued, and the fourth element is the
* total number of callbacks queued.
*/
-TRACE_EVENT(rcu_callback,
+TRACE_EVENT_RCU(rcu_callback,

TP_PROTO(const char *rcuname, struct rcu_head *rhp, long qlen_lazy,
long qlen),
@@ -504,7 +508,7 @@ TRACE_EVENT(rcu_callback,
* the fourth argument is the number of lazy callbacks queued, and the
* fifth argument is the total number of callbacks queued.
*/
-TRACE_EVENT(rcu_kfree_callback,
+TRACE_EVENT_RCU(rcu_kfree_callback,

TP_PROTO(const char *rcuname, struct rcu_head *rhp, unsigned long offset,
long qlen_lazy, long qlen),
@@ -539,7 +543,7 @@ TRACE_EVENT(rcu_kfree_callback,
* the total number of callbacks queued, and the fourth argument is
* the current RCU-callback batch limit.
*/
-TRACE_EVENT(rcu_batch_start,
+TRACE_EVENT_RCU(rcu_batch_start,

TP_PROTO(const char *rcuname, long qlen_lazy, long qlen, long blimit),

@@ -569,7 +573,7 @@ TRACE_EVENT(rcu_batch_start,
* The first argument is the type of RCU, and the second argument is
* a pointer to the RCU callback itself.
*/
-TRACE_EVENT(rcu_invoke_callback,
+TRACE_EVENT_RCU(rcu_invoke_callback,

TP_PROTO(const char *rcuname, struct rcu_head *rhp),

@@ -598,7 +602,7 @@ TRACE_EVENT(rcu_invoke_callback,
* is the offset of the callback within the enclosing RCU-protected
* data structure.
*/
-TRACE_EVENT(rcu_invoke_kfree_callback,
+TRACE_EVENT_RCU(rcu_invoke_kfree_callback,

TP_PROTO(const char *rcuname, struct rcu_head *rhp, unsigned long offset),

@@ -631,7 +635,7 @@ TRACE_EVENT(rcu_invoke_kfree_callback,
* and the sixth argument (risk) is the return value from
* rcu_is_callbacks_kthread().
*/
-TRACE_EVENT(rcu_batch_end,
+TRACE_EVENT_RCU(rcu_batch_end,

TP_PROTO(const char *rcuname, int callbacks_invoked,
char cb, char nr, char iit, char risk),
@@ -673,7 +677,7 @@ TRACE_EVENT(rcu_batch_end,
* callback address can be NULL.
*/
#define RCUTORTURENAME_LEN 8
-TRACE_EVENT(rcu_torture_read,
+TRACE_EVENT_RCU(rcu_torture_read,

TP_PROTO(const char *rcutorturename, struct rcu_head *rhp,
unsigned long secs, unsigned long c_old, unsigned long c),
@@ -721,7 +725,7 @@ TRACE_EVENT(rcu_torture_read,
* The "cpu" argument is the CPU or -1 if meaningless, the "cnt" argument
* is the count of remaining callbacks, and "done" is the piggybacking count.
*/
-TRACE_EVENT(rcu_barrier,
+TRACE_EVENT_RCU(rcu_barrier,

TP_PROTO(const char *rcuname, const char *s, int cpu, int cnt, unsigned long done),

@@ -748,41 +752,6 @@ TRACE_EVENT(rcu_barrier,
__entry->done)
);

-#else /* #ifdef CONFIG_RCU_TRACE */
-
-#define trace_rcu_grace_period(rcuname, gp_seq, gpevent) do { } while (0)
-#define trace_rcu_future_grace_period(rcuname, gp_seq, gp_seq_req, \
- level, grplo, grphi, event) \
- do { } while (0)
-#define trace_rcu_grace_period_init(rcuname, gp_seq, level, grplo, grphi, \
- qsmask) do { } while (0)
-#define trace_rcu_exp_grace_period(rcuname, gqseq, gpevent) \
- do { } while (0)
-#define trace_rcu_exp_funnel_lock(rcuname, level, grplo, grphi, gpevent) \
- do { } while (0)
-#define trace_rcu_nocb_wake(rcuname, cpu, reason) do { } while (0)
-#define trace_rcu_preempt_task(rcuname, pid, gp_seq) do { } while (0)
-#define trace_rcu_unlock_preempted_task(rcuname, gp_seq, pid) do { } while (0)
-#define trace_rcu_quiescent_state_report(rcuname, gp_seq, mask, qsmask, level, \
- grplo, grphi, gp_tasks) do { } \
- while (0)
-#define trace_rcu_fqs(rcuname, gp_seq, cpu, qsevent) do { } while (0)
-#define trace_rcu_dyntick(polarity, oldnesting, newnesting, dyntick) do { } while (0)
-#define trace_rcu_callback(rcuname, rhp, qlen_lazy, qlen) do { } while (0)
-#define trace_rcu_kfree_callback(rcuname, rhp, offset, qlen_lazy, qlen) \
- do { } while (0)
-#define trace_rcu_batch_start(rcuname, qlen_lazy, qlen, blimit) \
- do { } while (0)
-#define trace_rcu_invoke_callback(rcuname, rhp) do { } while (0)
-#define trace_rcu_invoke_kfree_callback(rcuname, rhp, offset) do { } while (0)
-#define trace_rcu_batch_end(rcuname, callbacks_invoked, cb, nr, iit, risk) \
- do { } while (0)
-#define trace_rcu_torture_read(rcutorturename, rhp, secs, c_old, c) \
- do { } while (0)
-#define trace_rcu_barrier(name, s, cpu, cnt, done) do { } while (0)
-
-#endif /* #else #ifdef CONFIG_RCU_TRACE */
-
#endif /* _TRACE_RCU_H */

/* This part must be outside protection */
diff --git a/kernel/rcu/rcu.h b/kernel/rcu/rcu.h
index acee72c0b24b..442ace406ac9 100644
--- a/kernel/rcu/rcu.h
+++ b/kernel/rcu/rcu.h
@@ -11,11 +11,6 @@
#define __LINUX_RCU_H

#include <trace/events/rcu.h>
-#ifdef CONFIG_RCU_TRACE
-#define RCU_TRACE(stmt) stmt
-#else /* #ifdef CONFIG_RCU_TRACE */
-#define RCU_TRACE(stmt)
-#endif /* #else #ifdef CONFIG_RCU_TRACE */

/* Offset to allow distinguishing irq vs. task-based idle entry/exit. */
#define DYNTICK_IRQ_NONIDLE ((LONG_MAX / 2) + 1)
@@ -216,12 +211,12 @@ static inline bool __rcu_reclaim(const char *rn, struct rcu_head *head)

rcu_lock_acquire(&rcu_callback_map);
if (__is_kfree_rcu_offset(offset)) {
- RCU_TRACE(trace_rcu_invoke_kfree_callback(rn, head, offset);)
+ trace_rcu_invoke_kfree_callback(rn, head, offset);
kfree((void *)head - offset);
rcu_lock_release(&rcu_callback_map);
return true;
} else {
- RCU_TRACE(trace_rcu_invoke_callback(rn, head);)
+ trace_rcu_invoke_callback(rn, head);
f = head->func;
WRITE_ONCE(head->func, (rcu_callback_t)0L);
f(head);
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index acd6ccf56faf..906563a1cdea 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -2352,14 +2352,14 @@ rcu_check_quiescent_state(struct rcu_data *rdp)
*/
int rcutree_dying_cpu(unsigned int cpu)
{
- RCU_TRACE(bool blkd;)
- RCU_TRACE(struct rcu_data *rdp = this_cpu_ptr(&rcu_data);)
- RCU_TRACE(struct rcu_node *rnp = rdp->mynode;)
+ bool blkd;
+ struct rcu_data *rdp = this_cpu_ptr(&rcu_data);
+ struct rcu_node *rnp = rdp->mynode;

if (!IS_ENABLED(CONFIG_HOTPLUG_CPU))
return 0;

- RCU_TRACE(blkd = !!(rnp->qsmask & rdp->grpmask);)
+ blkd = !!(rnp->qsmask & rdp->grpmask);
trace_rcu_grace_period(rcu_state.name, rnp->gp_seq,
blkd ? TPS("cpuofl") : TPS("cpuofl-bgp"));
return 0;
--
2.20.1