Commit a32e01ee authored by Matthew Wilcox's avatar Matthew Wilcox Committed by Paul E. McKenney
Browse files

rcu: Use wrapper for lockdep asserts 



Commits c0b334c5 and ea9b0c8a introduced new sparse warnings
by accessing rcu_node->lock directly and ignoring the __private
marker.  Introduce a new wrapper and use it.  Also fix a similar problem
in srcutree.c introduced by a3883df3.

Signed-off-by: default avatarMatthew Wilcox <mawilcox@microsoft.com>
Signed-off-by: default avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
parent 65518db8

kernel/rcu/rcu.h

+4 −1
Original line number Diff line number Diff line
@@ -337,7 +337,7 @@ do { \ 
} while (0)



#define raw_spin_unlock_irqrestore_rcu_node(p, flags)			\

	raw_spin_unlock_irqrestore(&ACCESS_PRIVATE(p, lock), flags)	\

	raw_spin_unlock_irqrestore(&ACCESS_PRIVATE(p, lock), flags)



#define raw_spin_trylock_rcu_node(p)					\

({									\
@@ -348,6 +348,9 @@ do { \ 
	___locked;							\

})



#define raw_lockdep_assert_held_rcu_node(p)				\

	lockdep_assert_held(&ACCESS_PRIVATE(p, lock))



#endif /* #if defined(SRCU) || !defined(TINY_RCU) */



#ifdef CONFIG_TINY_RCU

kernel/rcu/srcutree.c

+1 −1
Original line number Diff line number Diff line
@@ -439,7 +439,7 @@ static void srcu_gp_start(struct srcu_struct *sp) 
	struct srcu_data *sdp = this_cpu_ptr(sp->sda);

	int state;



	lockdep_assert_held(&sp->lock);

	lockdep_assert_held(&ACCESS_PRIVATE(sp, lock));

	WARN_ON_ONCE(ULONG_CMP_GE(sp->srcu_gp_seq, sp->srcu_gp_seq_needed));

	rcu_segcblist_advance(&sdp->srcu_cblist,

			      rcu_seq_current(&sp->srcu_gp_seq));

kernel/rcu/tree.c

+12 −12
Original line number Diff line number Diff line
@@ -1161,7 +1161,7 @@ static int rcu_is_cpu_rrupt_from_idle(void) 
 */

static void rcu_gpnum_ovf(struct rcu_node *rnp, struct rcu_data *rdp)

{

	lockdep_assert_held(&rnp->lock);

	raw_lockdep_assert_held_rcu_node(rnp);

	if (ULONG_CMP_LT(READ_ONCE(rdp->gpnum) + ULONG_MAX / 4, rnp->gpnum))

		WRITE_ONCE(rdp->gpwrap, true);

	if (ULONG_CMP_LT(rdp->rcu_iw_gpnum + ULONG_MAX / 4, rnp->gpnum))
@@ -1629,7 +1629,7 @@ void rcu_cpu_stall_reset(void) 
static unsigned long rcu_cbs_completed(struct rcu_state *rsp,

				       struct rcu_node *rnp)

{

	lockdep_assert_held(&rnp->lock);

	raw_lockdep_assert_held_rcu_node(rnp);



	/*

	 * If RCU is idle, we just wait for the next grace period.
@@ -1676,7 +1676,7 @@ rcu_start_future_gp(struct rcu_node *rnp, struct rcu_data *rdp, 
	bool ret = false;

	struct rcu_node *rnp_root = rcu_get_root(rdp->rsp);



	lockdep_assert_held(&rnp->lock);

	raw_lockdep_assert_held_rcu_node(rnp);



	/*

	 * Pick up grace-period number for new callbacks.  If this
@@ -1804,7 +1804,7 @@ static bool rcu_accelerate_cbs(struct rcu_state *rsp, struct rcu_node *rnp, 
{

	bool ret = false;



	lockdep_assert_held(&rnp->lock);

	raw_lockdep_assert_held_rcu_node(rnp);



	/* If no pending (not yet ready to invoke) callbacks, nothing to do. */

	if (!rcu_segcblist_pend_cbs(&rdp->cblist))
@@ -1844,7 +1844,7 @@ static bool rcu_accelerate_cbs(struct rcu_state *rsp, struct rcu_node *rnp, 
static bool rcu_advance_cbs(struct rcu_state *rsp, struct rcu_node *rnp,

			    struct rcu_data *rdp)

{

	lockdep_assert_held(&rnp->lock);

	raw_lockdep_assert_held_rcu_node(rnp);



	/* If no pending (not yet ready to invoke) callbacks, nothing to do. */

	if (!rcu_segcblist_pend_cbs(&rdp->cblist))
@@ -1872,7 +1872,7 @@ static bool __note_gp_changes(struct rcu_state *rsp, struct rcu_node *rnp, 
	bool ret;

	bool need_gp;



	lockdep_assert_held(&rnp->lock);

	raw_lockdep_assert_held_rcu_node(rnp);



	/* Handle the ends of any preceding grace periods first. */

	if (rdp->completed == rnp->completed &&
@@ -2297,7 +2297,7 @@ static bool 
rcu_start_gp_advanced(struct rcu_state *rsp, struct rcu_node *rnp,

		      struct rcu_data *rdp)

{

	lockdep_assert_held(&rnp->lock);

	raw_lockdep_assert_held_rcu_node(rnp);

	if (!rsp->gp_kthread || !cpu_needs_another_gp(rsp, rdp)) {

		/*

		 * Either we have not yet spawned the grace-period
@@ -2359,7 +2359,7 @@ static bool rcu_start_gp(struct rcu_state *rsp) 
static void rcu_report_qs_rsp(struct rcu_state *rsp, unsigned long flags)

	__releases(rcu_get_root(rsp)->lock)

{

	lockdep_assert_held(&rcu_get_root(rsp)->lock);

	raw_lockdep_assert_held_rcu_node(rcu_get_root(rsp));

	WARN_ON_ONCE(!rcu_gp_in_progress(rsp));

	WRITE_ONCE(rsp->gp_flags, READ_ONCE(rsp->gp_flags) | RCU_GP_FLAG_FQS);

	raw_spin_unlock_irqrestore_rcu_node(rcu_get_root(rsp), flags);
@@ -2384,7 +2384,7 @@ rcu_report_qs_rnp(unsigned long mask, struct rcu_state *rsp, 
	unsigned long oldmask = 0;

	struct rcu_node *rnp_c;



	lockdep_assert_held(&rnp->lock);

	raw_lockdep_assert_held_rcu_node(rnp);



	/* Walk up the rcu_node hierarchy. */

	for (;;) {
@@ -2448,7 +2448,7 @@ static void rcu_report_unblock_qs_rnp(struct rcu_state *rsp, 
	unsigned long mask;

	struct rcu_node *rnp_p;



	lockdep_assert_held(&rnp->lock);

	raw_lockdep_assert_held_rcu_node(rnp);

	if (rcu_state_p == &rcu_sched_state || rsp != rcu_state_p ||

	    rnp->qsmask != 0 || rcu_preempt_blocked_readers_cgp(rnp)) {

		raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
@@ -2593,7 +2593,7 @@ static void rcu_cleanup_dead_rnp(struct rcu_node *rnp_leaf) 
	long mask;

	struct rcu_node *rnp = rnp_leaf;



	lockdep_assert_held(&rnp->lock);

	raw_lockdep_assert_held_rcu_node(rnp);

	if (!IS_ENABLED(CONFIG_HOTPLUG_CPU) ||

	    rnp->qsmaskinit || rcu_preempt_has_tasks(rnp))

		return;
@@ -3596,7 +3596,7 @@ static void rcu_init_new_rnp(struct rcu_node *rnp_leaf) 
	long mask;

	struct rcu_node *rnp = rnp_leaf;



	lockdep_assert_held(&rnp->lock);

	raw_lockdep_assert_held_rcu_node(rnp);

	for (;;) {

		mask = rnp->grpmask;

		rnp = rnp->parent;

kernel/rcu/tree_plugin.h

+2 −2
Original line number Diff line number Diff line
@@ -180,7 +180,7 @@ static void rcu_preempt_ctxt_queue(struct rcu_node *rnp, struct rcu_data *rdp) 
			 (rnp->expmask & rdp->grpmask ? RCU_EXP_BLKD : 0);

	struct task_struct *t = current;



	lockdep_assert_held(&rnp->lock);

	raw_lockdep_assert_held_rcu_node(rnp);

	WARN_ON_ONCE(rdp->mynode != rnp);

	WARN_ON_ONCE(rnp->level != rcu_num_lvls - 1);
@@ -1044,7 +1044,7 @@ static void rcu_initiate_boost(struct rcu_node *rnp, unsigned long flags) 
{

	struct task_struct *t;



	lockdep_assert_held(&rnp->lock);

	raw_lockdep_assert_held_rcu_node(rnp);

	if (!rcu_preempt_blocked_readers_cgp(rnp) && rnp->exp_tasks == NULL) {

		raw_spin_unlock_irqrestore_rcu_node(rnp, flags);

		return;

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