rcutorture: Don't do need_resched() testing if ->sync is NULL (a7eb937b) · Commits · 戴 / test

If cur_ops->sync is NULL, rcu_torture_fwd_prog_nr() will nevertheless attempt to call through it. This commit therefore flags cases where neither need_resched() nor call_rcu() forward-progress testing can be performed due to NULL function pointers, and also causes rcu_torture_fwd_prog_nr() to take an early exit if cur_ops->sync() is NULL. Reported-by:

Tom Rix <trix@redhat.com> Signed-off-by:

Paul E. McKenney <paulmck@kernel.org>

kernel/rcu/rcutorture.c

+5 −3

Original line number	Diff line number	Diff line
		@@ -1923,7 +1923,9 @@ static void rcu_torture_fwd_prog_nr(struct rcu_fwd *rfp,
		unsigned long stopat;
		static DEFINE_TORTURE_RANDOM(trs);

		if (cur_ops->call && cur_ops->sync && cur_ops->cb_barrier) {
		if (!cur_ops->sync)
		return; // Cannot do need_resched() forward progress testing without ->sync.
		if (cur_ops->call && cur_ops->cb_barrier) {
		init_rcu_head_on_stack(&fcs.rh);
		selfpropcb = true;
		}
		@@ -2149,8 +2151,8 @@ static int __init rcu_torture_fwd_prog_init(void)

		if (!fwd_progress)
		return 0; /* Not requested, so don't do it. */
		if (!cur_ops->stall_dur \|\| cur_ops->stall_dur() <= 0 \|\|
		cur_ops == &rcu_busted_ops) {
		if ((!cur_ops->sync && !cur_ops->call) \|\|
		!cur_ops->stall_dur \|\| cur_ops->stall_dur() <= 0 \|\| cur_ops == &rcu_busted_ops) {
		VERBOSE_TOROUT_STRING("rcu_torture_fwd_prog_init: Disabled, unsupported by RCU flavor under test");
		return 0;
		}

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