diff options
Diffstat (limited to 'kernel/rcu/rcutorture.c')
-rw-r--r-- | kernel/rcu/rcutorture.c | 86 |
1 files changed, 55 insertions, 31 deletions
diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c index ab4215266ebe..8b410d982990 100644 --- a/kernel/rcu/rcutorture.c +++ b/kernel/rcu/rcutorture.c @@ -1432,28 +1432,34 @@ static void rcutorture_one_extend(int *readstate, int newstate, /* First, put new protection in place to avoid critical-section gap. */ if (statesnew & RCUTORTURE_RDR_BH) local_bh_disable(); + if (statesnew & RCUTORTURE_RDR_RBH) + rcu_read_lock_bh(); if (statesnew & RCUTORTURE_RDR_IRQ) local_irq_disable(); if (statesnew & RCUTORTURE_RDR_PREEMPT) preempt_disable(); - if (statesnew & RCUTORTURE_RDR_RBH) - rcu_read_lock_bh(); if (statesnew & RCUTORTURE_RDR_SCHED) rcu_read_lock_sched(); if (statesnew & RCUTORTURE_RDR_RCU) idxnew = cur_ops->readlock() << RCUTORTURE_RDR_SHIFT; - /* Next, remove old protection, irq first due to bh conflict. */ + /* + * Next, remove old protection, in decreasing order of strength + * to avoid unlock paths that aren't safe in the stronger + * context. Namely: BH can not be enabled with disabled interrupts. + * Additionally PREEMPT_RT requires that BH is enabled in preemptible + * context. + */ if (statesold & RCUTORTURE_RDR_IRQ) local_irq_enable(); - if (statesold & RCUTORTURE_RDR_BH) - local_bh_enable(); if (statesold & RCUTORTURE_RDR_PREEMPT) preempt_enable(); - if (statesold & RCUTORTURE_RDR_RBH) - rcu_read_unlock_bh(); if (statesold & RCUTORTURE_RDR_SCHED) rcu_read_unlock_sched(); + if (statesold & RCUTORTURE_RDR_BH) + local_bh_enable(); + if (statesold & RCUTORTURE_RDR_RBH) + rcu_read_unlock_bh(); if (statesold & RCUTORTURE_RDR_RCU) { bool lockit = !statesnew && !(torture_random(trsp) & 0xffff); @@ -1496,6 +1502,9 @@ rcutorture_extend_mask(int oldmask, struct torture_random_state *trsp) int mask = rcutorture_extend_mask_max(); unsigned long randmask1 = torture_random(trsp) >> 8; unsigned long randmask2 = randmask1 >> 3; + unsigned long preempts = RCUTORTURE_RDR_PREEMPT | RCUTORTURE_RDR_SCHED; + unsigned long preempts_irq = preempts | RCUTORTURE_RDR_IRQ; + unsigned long bhs = RCUTORTURE_RDR_BH | RCUTORTURE_RDR_RBH; WARN_ON_ONCE(mask >> RCUTORTURE_RDR_SHIFT); /* Mostly only one bit (need preemption!), sometimes lots of bits. */ @@ -1503,11 +1512,26 @@ rcutorture_extend_mask(int oldmask, struct torture_random_state *trsp) mask = mask & randmask2; else mask = mask & (1 << (randmask2 % RCUTORTURE_RDR_NBITS)); - /* Can't enable bh w/irq disabled. */ - if ((mask & RCUTORTURE_RDR_IRQ) && - ((!(mask & RCUTORTURE_RDR_BH) && (oldmask & RCUTORTURE_RDR_BH)) || - (!(mask & RCUTORTURE_RDR_RBH) && (oldmask & RCUTORTURE_RDR_RBH)))) - mask |= RCUTORTURE_RDR_BH | RCUTORTURE_RDR_RBH; + + /* + * Can't enable bh w/irq disabled. + */ + if (mask & RCUTORTURE_RDR_IRQ) + mask |= oldmask & bhs; + + /* + * Ideally these sequences would be detected in debug builds + * (regardless of RT), but until then don't stop testing + * them on non-RT. + */ + if (IS_ENABLED(CONFIG_PREEMPT_RT)) { + /* Can't modify BH in atomic context */ + if (oldmask & preempts_irq) + mask &= ~bhs; + if ((oldmask | mask) & preempts_irq) + mask |= oldmask & bhs; + } + return mask ?: RCUTORTURE_RDR_RCU; } @@ -2449,7 +2473,7 @@ static int __init rcu_torture_fwd_prog_init(void) } if (stall_cpu > 0) { VERBOSE_TOROUT_STRING("rcu_torture_fwd_prog_init: Disabled, conflicts with CPU-stall testing"); - if (IS_MODULE(CONFIG_RCU_TORTURE_TESTS)) + if (IS_MODULE(CONFIG_RCU_TORTURE_TEST)) return -EINVAL; /* In module, can fail back to user. */ WARN_ON(1); /* Make sure rcutorture notices conflict. */ return 0; @@ -2741,7 +2765,7 @@ static int rcu_torture_read_exit(void *unused) static int rcu_torture_read_exit_init(void) { if (read_exit_burst <= 0) - return -EINVAL; + return 0; init_waitqueue_head(&read_exit_wq); read_exit_child_stop = false; read_exit_child_stopped = false; @@ -2819,7 +2843,7 @@ rcu_torture_cleanup(void) rcutorture_seq_diff(gp_seq, start_gp_seq)); torture_stop_kthread(rcu_torture_stats, stats_task); torture_stop_kthread(rcu_torture_fqs, fqs_task); - if (rcu_torture_can_boost()) + if (rcu_torture_can_boost() && rcutor_hp >= 0) cpuhp_remove_state(rcutor_hp); /* @@ -3037,7 +3061,7 @@ rcu_torture_init(void) rcu_torture_write_types(); firsterr = torture_create_kthread(rcu_torture_writer, NULL, writer_task); - if (firsterr) + if (torture_init_error(firsterr)) goto unwind; if (nfakewriters > 0) { fakewriter_tasks = kcalloc(nfakewriters, @@ -3052,7 +3076,7 @@ rcu_torture_init(void) for (i = 0; i < nfakewriters; i++) { firsterr = torture_create_kthread(rcu_torture_fakewriter, NULL, fakewriter_tasks[i]); - if (firsterr) + if (torture_init_error(firsterr)) goto unwind; } reader_tasks = kcalloc(nrealreaders, sizeof(reader_tasks[0]), @@ -3068,7 +3092,7 @@ rcu_torture_init(void) rcu_torture_reader_mbchk[i].rtc_chkrdr = -1; firsterr = torture_create_kthread(rcu_torture_reader, (void *)i, reader_tasks[i]); - if (firsterr) + if (torture_init_error(firsterr)) goto unwind; } nrealnocbers = nocbs_nthreads; @@ -3088,18 +3112,18 @@ rcu_torture_init(void) } for (i = 0; i < nrealnocbers; i++) { firsterr = torture_create_kthread(rcu_nocb_toggle, NULL, nocb_tasks[i]); - if (firsterr) + if (torture_init_error(firsterr)) goto unwind; } if (stat_interval > 0) { firsterr = torture_create_kthread(rcu_torture_stats, NULL, stats_task); - if (firsterr) + if (torture_init_error(firsterr)) goto unwind; } if (test_no_idle_hz && shuffle_interval > 0) { firsterr = torture_shuffle_init(shuffle_interval * HZ); - if (firsterr) + if (torture_init_error(firsterr)) goto unwind; } if (stutter < 0) @@ -3109,7 +3133,7 @@ rcu_torture_init(void) t = cur_ops->stall_dur ? cur_ops->stall_dur() : stutter * HZ; firsterr = torture_stutter_init(stutter * HZ, t); - if (firsterr) + if (torture_init_error(firsterr)) goto unwind; } if (fqs_duration < 0) @@ -3118,7 +3142,7 @@ rcu_torture_init(void) /* Create the fqs thread */ firsterr = torture_create_kthread(rcu_torture_fqs, NULL, fqs_task); - if (firsterr) + if (torture_init_error(firsterr)) goto unwind; } if (test_boost_interval < 1) @@ -3132,9 +3156,9 @@ rcu_torture_init(void) firsterr = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "RCU_TORTURE", rcutorture_booster_init, rcutorture_booster_cleanup); - if (firsterr < 0) - goto unwind; rcutor_hp = firsterr; + if (torture_init_error(firsterr)) + goto unwind; // Testing RCU priority boosting requires rcutorture do // some serious abuse. Counter this by running ksoftirqd @@ -3153,23 +3177,23 @@ rcu_torture_init(void) } shutdown_jiffies = jiffies + shutdown_secs * HZ; firsterr = torture_shutdown_init(shutdown_secs, rcu_torture_cleanup); - if (firsterr) + if (torture_init_error(firsterr)) goto unwind; firsterr = torture_onoff_init(onoff_holdoff * HZ, onoff_interval, rcutorture_sync); - if (firsterr) + if (torture_init_error(firsterr)) goto unwind; firsterr = rcu_torture_stall_init(); - if (firsterr) + if (torture_init_error(firsterr)) goto unwind; firsterr = rcu_torture_fwd_prog_init(); - if (firsterr) + if (torture_init_error(firsterr)) goto unwind; firsterr = rcu_torture_barrier_init(); - if (firsterr) + if (torture_init_error(firsterr)) goto unwind; firsterr = rcu_torture_read_exit_init(); - if (firsterr) + if (torture_init_error(firsterr)) goto unwind; if (object_debug) rcu_test_debug_objects(); |