From f6c8785f50443db4c70faebfc22e59e8064c35a5 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Thu, 8 May 2025 16:45:00 -0700 Subject: [PATCH] rcutorture: Check for no up/down readers at task level The design of testing of up/down readers such as srcu_down_read() and srcu_up_read() assumes that these are tested only by the rcu_torture_updown() kthread, and never by the rcu_torture_reader() kthread. Because we all know which road is paved with good intentions, this commit adds WARN_ON_ONCE() to verify that things are going to plan. Signed-off-by: Paul E. McKenney Signed-off-by: Neeraj Upadhyay (AMD) --- kernel/rcu/rcutorture.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c index f773d4f8f2ae5..10f3cc4861eef 100644 --- a/kernel/rcu/rcutorture.c +++ b/kernel/rcu/rcutorture.c @@ -2232,6 +2232,7 @@ rcutorture_loop_extend(int *readstate, bool insoftirq, struct torture_random_sta i = ((i | (i >> 3)) & RCUTORTURE_RDR_MAX_LOOPS) + 1; for (j = 0; j < i; j++) { mask = rcutorture_extend_mask(*readstate, trsp); + WARN_ON_ONCE(mask & RCUTORTURE_RDR_UPDOWN); rcutorture_one_extend(readstate, mask, insoftirq, trsp, &rtrsp[j]); } return &rtrsp[j]; @@ -2368,6 +2369,7 @@ static bool rcu_torture_one_read(struct torture_random_state *trsp, long myid) WARN_ON_ONCE(!rcu_is_watching()); init_rcu_torture_one_read_state(&rtors, trsp); newstate = rcutorture_extend_mask(rtors.readstate, trsp); + WARN_ON_ONCE(newstate & RCUTORTURE_RDR_UPDOWN); rcutorture_one_extend(&rtors.readstate, newstate, myid < 0, trsp, rtors.rtrsp++); if (!rcu_torture_one_read_start(&rtors, trsp, myid)) { rcutorture_one_extend(&rtors.readstate, 0, myid < 0, trsp, rtors.rtrsp); -- 2.47.2