| // SPDX-License-Identifier: GPL-2.0+ |
| /* |
| * Read-Copy Update module-based torture test facility |
| * |
| * Copyright (C) IBM Corporation, 2005, 2006 |
| * |
| * Authors: Paul E. McKenney <paulmck@linux.ibm.com> |
| * Josh Triplett <josh@joshtriplett.org> |
| * |
| * See also: Documentation/RCU/torture.rst |
| */ |
| |
| #define pr_fmt(fmt) fmt |
| |
| #include <linux/types.h> |
| #include <linux/kernel.h> |
| #include <linux/init.h> |
| #include <linux/module.h> |
| #include <linux/kthread.h> |
| #include <linux/err.h> |
| #include <linux/spinlock.h> |
| #include <linux/smp.h> |
| #include <linux/rcupdate_wait.h> |
| #include <linux/interrupt.h> |
| #include <linux/sched/signal.h> |
| #include <uapi/linux/sched/types.h> |
| #include <linux/atomic.h> |
| #include <linux/bitops.h> |
| #include <linux/completion.h> |
| #include <linux/moduleparam.h> |
| #include <linux/percpu.h> |
| #include <linux/notifier.h> |
| #include <linux/reboot.h> |
| #include <linux/freezer.h> |
| #include <linux/cpu.h> |
| #include <linux/delay.h> |
| #include <linux/stat.h> |
| #include <linux/srcu.h> |
| #include <linux/slab.h> |
| #include <linux/trace_clock.h> |
| #include <asm/byteorder.h> |
| #include <linux/torture.h> |
| #include <linux/vmalloc.h> |
| #include <linux/sched/debug.h> |
| #include <linux/sched/sysctl.h> |
| #include <linux/oom.h> |
| #include <linux/tick.h> |
| #include <linux/rcupdate_trace.h> |
| #include <linux/nmi.h> |
| |
| #include "rcu.h" |
| |
| MODULE_LICENSE("GPL"); |
| MODULE_AUTHOR("Paul E. McKenney <paulmck@linux.ibm.com> and Josh Triplett <josh@joshtriplett.org>"); |
| |
| /* Bits for ->extendables field, extendables param, and related definitions. */ |
| #define RCUTORTURE_RDR_SHIFT_1 8 /* Put SRCU index in upper bits. */ |
| #define RCUTORTURE_RDR_MASK_1 (1 << RCUTORTURE_RDR_SHIFT_1) |
| #define RCUTORTURE_RDR_SHIFT_2 9 /* Put SRCU index in upper bits. */ |
| #define RCUTORTURE_RDR_MASK_2 (1 << RCUTORTURE_RDR_SHIFT_2) |
| #define RCUTORTURE_RDR_BH 0x01 /* Extend readers by disabling bh. */ |
| #define RCUTORTURE_RDR_IRQ 0x02 /* ... disabling interrupts. */ |
| #define RCUTORTURE_RDR_PREEMPT 0x04 /* ... disabling preemption. */ |
| #define RCUTORTURE_RDR_RBH 0x08 /* ... rcu_read_lock_bh(). */ |
| #define RCUTORTURE_RDR_SCHED 0x10 /* ... rcu_read_lock_sched(). */ |
| #define RCUTORTURE_RDR_RCU_1 0x20 /* ... entering another RCU reader. */ |
| #define RCUTORTURE_RDR_RCU_2 0x40 /* ... entering another RCU reader. */ |
| #define RCUTORTURE_RDR_NBITS 7 /* Number of bits defined above. */ |
| #define RCUTORTURE_MAX_EXTEND \ |
| (RCUTORTURE_RDR_BH | RCUTORTURE_RDR_IRQ | RCUTORTURE_RDR_PREEMPT | \ |
| RCUTORTURE_RDR_RBH | RCUTORTURE_RDR_SCHED) |
| #define RCUTORTURE_RDR_MAX_LOOPS 0x7 /* Maximum reader extensions. */ |
| /* Must be power of two minus one. */ |
| #define RCUTORTURE_RDR_MAX_SEGS (RCUTORTURE_RDR_MAX_LOOPS + 3) |
| |
| torture_param(int, extendables, RCUTORTURE_MAX_EXTEND, |
| "Extend readers by disabling bh (1), irqs (2), or preempt (4)"); |
| torture_param(int, fqs_duration, 0, "Duration of fqs bursts (us), 0 to disable"); |
| torture_param(int, fqs_holdoff, 0, "Holdoff time within fqs bursts (us)"); |
| torture_param(int, fqs_stutter, 3, "Wait time between fqs bursts (s)"); |
| torture_param(int, fwd_progress, 1, "Number of grace-period forward progress tasks (0 to disable)"); |
| torture_param(int, fwd_progress_div, 4, "Fraction of CPU stall to wait"); |
| torture_param(int, fwd_progress_holdoff, 60, "Time between forward-progress tests (s)"); |
| torture_param(bool, fwd_progress_need_resched, 1, "Hide cond_resched() behind need_resched()"); |
| torture_param(bool, gp_cond, false, "Use conditional/async GP wait primitives"); |
| torture_param(bool, gp_cond_exp, false, "Use conditional/async expedited GP wait primitives"); |
| torture_param(bool, gp_exp, false, "Use expedited GP wait primitives"); |
| torture_param(bool, gp_normal, false, "Use normal (non-expedited) GP wait primitives"); |
| torture_param(bool, gp_poll, false, "Use polling GP wait primitives"); |
| torture_param(bool, gp_poll_exp, false, "Use polling expedited GP wait primitives"); |
| torture_param(bool, gp_sync, false, "Use synchronous GP wait primitives"); |
| torture_param(int, irqreader, 1, "Allow RCU readers from irq handlers"); |
| torture_param(int, leakpointer, 0, "Leak pointer dereferences from readers"); |
| torture_param(int, n_barrier_cbs, 0, "# of callbacks/kthreads for barrier testing"); |
| torture_param(int, nfakewriters, 4, "Number of RCU fake writer threads"); |
| torture_param(int, nreaders, -1, "Number of RCU reader threads"); |
| torture_param(int, object_debug, 0, "Enable debug-object double call_rcu() testing"); |
| torture_param(int, onoff_holdoff, 0, "Time after boot before CPU hotplugs (s)"); |
| torture_param(int, onoff_interval, 0, "Time between CPU hotplugs (jiffies), 0=disable"); |
| torture_param(int, nocbs_nthreads, 0, "Number of NOCB toggle threads, 0 to disable"); |
| torture_param(int, nocbs_toggle, 1000, "Time between toggling nocb state (ms)"); |
| torture_param(int, read_exit_delay, 13, "Delay between read-then-exit episodes (s)"); |
| torture_param(int, read_exit_burst, 16, "# of read-then-exit bursts per episode, zero to disable"); |
| torture_param(int, shuffle_interval, 3, "Number of seconds between shuffles"); |
| torture_param(int, shutdown_secs, 0, "Shutdown time (s), <= zero to disable."); |
| torture_param(int, stall_cpu, 0, "Stall duration (s), zero to disable."); |
| torture_param(int, stall_cpu_holdoff, 10, "Time to wait before starting stall (s)."); |
| torture_param(bool, stall_no_softlockup, false, "Avoid softlockup warning during cpu stall."); |
| torture_param(int, stall_cpu_irqsoff, 0, "Disable interrupts while stalling."); |
| torture_param(int, stall_cpu_block, 0, "Sleep while stalling."); |
| torture_param(int, stall_gp_kthread, 0, "Grace-period kthread stall duration (s)."); |
| torture_param(int, stat_interval, 60, "Number of seconds between stats printk()s"); |
| torture_param(int, stutter, 5, "Number of seconds to run/halt test"); |
| torture_param(int, test_boost, 1, "Test RCU prio boost: 0=no, 1=maybe, 2=yes."); |
| torture_param(int, test_boost_duration, 4, "Duration of each boost test, seconds."); |
| torture_param(int, test_boost_interval, 7, "Interval between boost tests, seconds."); |
| torture_param(bool, test_no_idle_hz, true, "Test support for tickless idle CPUs"); |
| torture_param(int, verbose, 1, "Enable verbose debugging printk()s"); |
| |
| static char *torture_type = "rcu"; |
| module_param(torture_type, charp, 0444); |
| MODULE_PARM_DESC(torture_type, "Type of RCU to torture (rcu, srcu, ...)"); |
| |
| static int nrealnocbers; |
| static int nrealreaders; |
| static struct task_struct *writer_task; |
| static struct task_struct **fakewriter_tasks; |
| static struct task_struct **reader_tasks; |
| static struct task_struct **nocb_tasks; |
| static struct task_struct *stats_task; |
| static struct task_struct *fqs_task; |
| static struct task_struct *boost_tasks[NR_CPUS]; |
| static struct task_struct *stall_task; |
| static struct task_struct **fwd_prog_tasks; |
| static struct task_struct **barrier_cbs_tasks; |
| static struct task_struct *barrier_task; |
| static struct task_struct *read_exit_task; |
| |
| #define RCU_TORTURE_PIPE_LEN 10 |
| |
| // Mailbox-like structure to check RCU global memory ordering. |
| struct rcu_torture_reader_check { |
| unsigned long rtc_myloops; |
| int rtc_chkrdr; |
| unsigned long rtc_chkloops; |
| int rtc_ready; |
| struct rcu_torture_reader_check *rtc_assigner; |
| } ____cacheline_internodealigned_in_smp; |
| |
| // Update-side data structure used to check RCU readers. |
| struct rcu_torture { |
| struct rcu_head rtort_rcu; |
| int rtort_pipe_count; |
| struct list_head rtort_free; |
| int rtort_mbtest; |
| struct rcu_torture_reader_check *rtort_chkp; |
| }; |
| |
| static LIST_HEAD(rcu_torture_freelist); |
| static struct rcu_torture __rcu *rcu_torture_current; |
| static unsigned long rcu_torture_current_version; |
| static struct rcu_torture rcu_tortures[10 * RCU_TORTURE_PIPE_LEN]; |
| static DEFINE_SPINLOCK(rcu_torture_lock); |
| static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], rcu_torture_count); |
| static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], rcu_torture_batch); |
| static atomic_t rcu_torture_wcount[RCU_TORTURE_PIPE_LEN + 1]; |
| static struct rcu_torture_reader_check *rcu_torture_reader_mbchk; |
| static atomic_t n_rcu_torture_alloc; |
| static atomic_t n_rcu_torture_alloc_fail; |
| static atomic_t n_rcu_torture_free; |
| static atomic_t n_rcu_torture_mberror; |
| static atomic_t n_rcu_torture_mbchk_fail; |
| static atomic_t n_rcu_torture_mbchk_tries; |
| static atomic_t n_rcu_torture_error; |
| static long n_rcu_torture_barrier_error; |
| static long n_rcu_torture_boost_ktrerror; |
| static long n_rcu_torture_boost_rterror; |
| static long n_rcu_torture_boost_failure; |
| static long n_rcu_torture_boosts; |
| static atomic_long_t n_rcu_torture_timers; |
| static long n_barrier_attempts; |
| static long n_barrier_successes; /* did rcu_barrier test succeed? */ |
| static unsigned long n_read_exits; |
| static struct list_head rcu_torture_removed; |
| static unsigned long shutdown_jiffies; |
| static unsigned long start_gp_seq; |
| static atomic_long_t n_nocb_offload; |
| static atomic_long_t n_nocb_deoffload; |
| |
| static int rcu_torture_writer_state; |
| #define RTWS_FIXED_DELAY 0 |
| #define RTWS_DELAY 1 |
| #define RTWS_REPLACE 2 |
| #define RTWS_DEF_FREE 3 |
| #define RTWS_EXP_SYNC 4 |
| #define RTWS_COND_GET 5 |
| #define RTWS_COND_GET_EXP 6 |
| #define RTWS_COND_SYNC 7 |
| #define RTWS_COND_SYNC_EXP 8 |
| #define RTWS_POLL_GET 9 |
| #define RTWS_POLL_GET_EXP 10 |
| #define RTWS_POLL_WAIT 11 |
| #define RTWS_POLL_WAIT_EXP 12 |
| #define RTWS_SYNC 13 |
| #define RTWS_STUTTER 14 |
| #define RTWS_STOPPING 15 |
| static const char * const rcu_torture_writer_state_names[] = { |
| "RTWS_FIXED_DELAY", |
| "RTWS_DELAY", |
| "RTWS_REPLACE", |
| "RTWS_DEF_FREE", |
| "RTWS_EXP_SYNC", |
| "RTWS_COND_GET", |
| "RTWS_COND_GET_EXP", |
| "RTWS_COND_SYNC", |
| "RTWS_COND_SYNC_EXP", |
| "RTWS_POLL_GET", |
| "RTWS_POLL_GET_EXP", |
| "RTWS_POLL_WAIT", |
| "RTWS_POLL_WAIT_EXP", |
| "RTWS_SYNC", |
| "RTWS_STUTTER", |
| "RTWS_STOPPING", |
| }; |
| |
| /* Record reader segment types and duration for first failing read. */ |
| struct rt_read_seg { |
| int rt_readstate; |
| unsigned long rt_delay_jiffies; |
| unsigned long rt_delay_ms; |
| unsigned long rt_delay_us; |
| bool rt_preempted; |
| }; |
| static int err_segs_recorded; |
| static struct rt_read_seg err_segs[RCUTORTURE_RDR_MAX_SEGS]; |
| static int rt_read_nsegs; |
| |
| static const char *rcu_torture_writer_state_getname(void) |
| { |
| unsigned int i = READ_ONCE(rcu_torture_writer_state); |
| |
| if (i >= ARRAY_SIZE(rcu_torture_writer_state_names)) |
| return "???"; |
| return rcu_torture_writer_state_names[i]; |
| } |
| |
| #ifdef CONFIG_RCU_TRACE |
| static u64 notrace rcu_trace_clock_local(void) |
| { |
| u64 ts = trace_clock_local(); |
| |
| (void)do_div(ts, NSEC_PER_USEC); |
| return ts; |
| } |
| #else /* #ifdef CONFIG_RCU_TRACE */ |
| static u64 notrace rcu_trace_clock_local(void) |
| { |
| return 0ULL; |
| } |
| #endif /* #else #ifdef CONFIG_RCU_TRACE */ |
| |
| /* |
| * Stop aggressive CPU-hog tests a bit before the end of the test in order |
| * to avoid interfering with test shutdown. |
| */ |
| static bool shutdown_time_arrived(void) |
| { |
| return shutdown_secs && time_after(jiffies, shutdown_jiffies - 30 * HZ); |
| } |
| |
| static unsigned long boost_starttime; /* jiffies of next boost test start. */ |
| static DEFINE_MUTEX(boost_mutex); /* protect setting boost_starttime */ |
| /* and boost task create/destroy. */ |
| static atomic_t barrier_cbs_count; /* Barrier callbacks registered. */ |
| static bool barrier_phase; /* Test phase. */ |
| static atomic_t barrier_cbs_invoked; /* Barrier callbacks invoked. */ |
| static wait_queue_head_t *barrier_cbs_wq; /* Coordinate barrier testing. */ |
| static DECLARE_WAIT_QUEUE_HEAD(barrier_wq); |
| |
| static atomic_t rcu_fwd_cb_nodelay; /* Short rcu_torture_delay() delays. */ |
| |
| /* |
| * Allocate an element from the rcu_tortures pool. |
| */ |
| static struct rcu_torture * |
| rcu_torture_alloc(void) |
| { |
| struct list_head *p; |
| |
| spin_lock_bh(&rcu_torture_lock); |
| if (list_empty(&rcu_torture_freelist)) { |
| atomic_inc(&n_rcu_torture_alloc_fail); |
| spin_unlock_bh(&rcu_torture_lock); |
| return NULL; |
| } |
| atomic_inc(&n_rcu_torture_alloc); |
| p = rcu_torture_freelist.next; |
| list_del_init(p); |
| spin_unlock_bh(&rcu_torture_lock); |
| return container_of(p, struct rcu_torture, rtort_free); |
| } |
| |
| /* |
| * Free an element to the rcu_tortures pool. |
| */ |
| static void |
| rcu_torture_free(struct rcu_torture *p) |
| { |
| atomic_inc(&n_rcu_torture_free); |
| spin_lock_bh(&rcu_torture_lock); |
| list_add_tail(&p->rtort_free, &rcu_torture_freelist); |
| spin_unlock_bh(&rcu_torture_lock); |
| } |
| |
| /* |
| * Operations vector for selecting different types of tests. |
| */ |
| |
| struct rcu_torture_ops { |
| int ttype; |
| void (*init)(void); |
| void (*cleanup)(void); |
| int (*readlock)(void); |
| void (*read_delay)(struct torture_random_state *rrsp, |
| struct rt_read_seg *rtrsp); |
| void (*readunlock)(int idx); |
| int (*readlock_held)(void); |
| unsigned long (*get_gp_seq)(void); |
| unsigned long (*gp_diff)(unsigned long new, unsigned long old); |
| void (*deferred_free)(struct rcu_torture *p); |
| void (*sync)(void); |
| void (*exp_sync)(void); |
| unsigned long (*get_gp_state_exp)(void); |
| unsigned long (*start_gp_poll_exp)(void); |
| bool (*poll_gp_state_exp)(unsigned long oldstate); |
| void (*cond_sync_exp)(unsigned long oldstate); |
| unsigned long (*get_gp_state)(void); |
| unsigned long (*get_gp_completed)(void); |
| unsigned long (*start_gp_poll)(void); |
| bool (*poll_gp_state)(unsigned long oldstate); |
| void (*cond_sync)(unsigned long oldstate); |
| call_rcu_func_t call; |
| void (*cb_barrier)(void); |
| void (*fqs)(void); |
| void (*stats)(void); |
| void (*gp_kthread_dbg)(void); |
| bool (*check_boost_failed)(unsigned long gp_state, int *cpup); |
| int (*stall_dur)(void); |
| long cbflood_max; |
| int irq_capable; |
| int can_boost; |
| int extendables; |
| int slow_gps; |
| int no_pi_lock; |
| const char *name; |
| }; |
| |
| static struct rcu_torture_ops *cur_ops; |
| |
| /* |
| * Definitions for rcu torture testing. |
| */ |
| |
| static int torture_readlock_not_held(void) |
| { |
| return rcu_read_lock_bh_held() || rcu_read_lock_sched_held(); |
| } |
| |
| static int rcu_torture_read_lock(void) __acquires(RCU) |
| { |
| rcu_read_lock(); |
| return 0; |
| } |
| |
| static void |
| rcu_read_delay(struct torture_random_state *rrsp, struct rt_read_seg *rtrsp) |
| { |
| unsigned long started; |
| unsigned long completed; |
| const unsigned long shortdelay_us = 200; |
| unsigned long longdelay_ms = 300; |
| unsigned long long ts; |
| |
| /* We want a short delay sometimes to make a reader delay the grace |
| * period, and we want a long delay occasionally to trigger |
| * force_quiescent_state. */ |
| |
| if (!atomic_read(&rcu_fwd_cb_nodelay) && |
| !(torture_random(rrsp) % (nrealreaders * 2000 * longdelay_ms))) { |
| started = cur_ops->get_gp_seq(); |
| ts = rcu_trace_clock_local(); |
| if (preempt_count() & (SOFTIRQ_MASK | HARDIRQ_MASK)) |
| longdelay_ms = 5; /* Avoid triggering BH limits. */ |
| mdelay(longdelay_ms); |
| rtrsp->rt_delay_ms = longdelay_ms; |
| completed = cur_ops->get_gp_seq(); |
| do_trace_rcu_torture_read(cur_ops->name, NULL, ts, |
| started, completed); |
| } |
| if (!(torture_random(rrsp) % (nrealreaders * 2 * shortdelay_us))) { |
| udelay(shortdelay_us); |
| rtrsp->rt_delay_us = shortdelay_us; |
| } |
| if (!preempt_count() && |
| !(torture_random(rrsp) % (nrealreaders * 500))) { |
| torture_preempt_schedule(); /* QS only if preemptible. */ |
| rtrsp->rt_preempted = true; |
| } |
| } |
| |
| static void rcu_torture_read_unlock(int idx) __releases(RCU) |
| { |
| rcu_read_unlock(); |
| } |
| |
| /* |
| * Update callback in the pipe. This should be invoked after a grace period. |
| */ |
| static bool |
| rcu_torture_pipe_update_one(struct rcu_torture *rp) |
| { |
| int i; |
| struct rcu_torture_reader_check *rtrcp = READ_ONCE(rp->rtort_chkp); |
| |
| if (rtrcp) { |
| WRITE_ONCE(rp->rtort_chkp, NULL); |
| smp_store_release(&rtrcp->rtc_ready, 1); // Pair with smp_load_acquire(). |
| } |
| i = READ_ONCE(rp->rtort_pipe_count); |
| if (i > RCU_TORTURE_PIPE_LEN) |
| i = RCU_TORTURE_PIPE_LEN; |
| atomic_inc(&rcu_torture_wcount[i]); |
| WRITE_ONCE(rp->rtort_pipe_count, i + 1); |
| if (rp->rtort_pipe_count >= RCU_TORTURE_PIPE_LEN) { |
| rp->rtort_mbtest = 0; |
| return true; |
| } |
| return false; |
| } |
| |
| /* |
| * Update all callbacks in the pipe. Suitable for synchronous grace-period |
| * primitives. |
| */ |
| static void |
| rcu_torture_pipe_update(struct rcu_torture *old_rp) |
| { |
| struct rcu_torture *rp; |
| struct rcu_torture *rp1; |
| |
| if (old_rp) |
| list_add(&old_rp->rtort_free, &rcu_torture_removed); |
| list_for_each_entry_safe(rp, rp1, &rcu_torture_removed, rtort_free) { |
| if (rcu_torture_pipe_update_one(rp)) { |
| list_del(&rp->rtort_free); |
| rcu_torture_free(rp); |
| } |
| } |
| } |
| |
| static void |
| rcu_torture_cb(struct rcu_head *p) |
| { |
| struct rcu_torture *rp = container_of(p, struct rcu_torture, rtort_rcu); |
| |
| if (torture_must_stop_irq()) { |
| /* Test is ending, just drop callbacks on the floor. */ |
| /* The next initialization will pick up the pieces. */ |
| return; |
| } |
| if (rcu_torture_pipe_update_one(rp)) |
| rcu_torture_free(rp); |
| else |
| cur_ops->deferred_free(rp); |
| } |
| |
| static unsigned long rcu_no_completed(void) |
| { |
| return 0; |
| } |
| |
| static void rcu_torture_deferred_free(struct rcu_torture *p) |
| { |
| call_rcu(&p->rtort_rcu, rcu_torture_cb); |
| } |
| |
| static void rcu_sync_torture_init(void) |
| { |
| INIT_LIST_HEAD(&rcu_torture_removed); |
| } |
| |
| static struct rcu_torture_ops rcu_ops = { |
| .ttype = RCU_FLAVOR, |
| .init = rcu_sync_torture_init, |
| .readlock = rcu_torture_read_lock, |
| .read_delay = rcu_read_delay, |
| .readunlock = rcu_torture_read_unlock, |
| .readlock_held = torture_readlock_not_held, |
| .get_gp_seq = rcu_get_gp_seq, |
| .gp_diff = rcu_seq_diff, |
| .deferred_free = rcu_torture_deferred_free, |
| .sync = synchronize_rcu, |
| .exp_sync = synchronize_rcu_expedited, |
| .get_gp_state = get_state_synchronize_rcu, |
| .get_gp_completed = get_completed_synchronize_rcu, |
| .start_gp_poll = start_poll_synchronize_rcu, |
| .poll_gp_state = poll_state_synchronize_rcu, |
| .cond_sync = cond_synchronize_rcu, |
| .get_gp_state_exp = get_state_synchronize_rcu, |
| .start_gp_poll_exp = start_poll_synchronize_rcu_expedited, |
| .poll_gp_state_exp = poll_state_synchronize_rcu, |
| .cond_sync_exp = cond_synchronize_rcu_expedited, |
| .call = call_rcu, |
| .cb_barrier = rcu_barrier, |
| .fqs = rcu_force_quiescent_state, |
| .stats = NULL, |
| .gp_kthread_dbg = show_rcu_gp_kthreads, |
| .check_boost_failed = rcu_check_boost_fail, |
| .stall_dur = rcu_jiffies_till_stall_check, |
| .irq_capable = 1, |
| .can_boost = IS_ENABLED(CONFIG_RCU_BOOST), |
| .extendables = RCUTORTURE_MAX_EXTEND, |
| .name = "rcu" |
| }; |
| |
| /* |
| * Don't even think about trying any of these in real life!!! |
| * The names includes "busted", and they really means it! |
| * The only purpose of these functions is to provide a buggy RCU |
| * implementation to make sure that rcutorture correctly emits |
| * buggy-RCU error messages. |
| */ |
| static void rcu_busted_torture_deferred_free(struct rcu_torture *p) |
| { |
| /* This is a deliberate bug for testing purposes only! */ |
| rcu_torture_cb(&p->rtort_rcu); |
| } |
| |
| static void synchronize_rcu_busted(void) |
| { |
| /* This is a deliberate bug for testing purposes only! */ |
| } |
| |
| static void |
| call_rcu_busted(struct rcu_head *head, rcu_callback_t func) |
| { |
| /* This is a deliberate bug for testing purposes only! */ |
| func(head); |
| } |
| |
| static struct rcu_torture_ops rcu_busted_ops = { |
| .ttype = INVALID_RCU_FLAVOR, |
| .init = rcu_sync_torture_init, |
| .readlock = rcu_torture_read_lock, |
| .read_delay = rcu_read_delay, /* just reuse rcu's version. */ |
| .readunlock = rcu_torture_read_unlock, |
| .readlock_held = torture_readlock_not_held, |
| .get_gp_seq = rcu_no_completed, |
| .deferred_free = rcu_busted_torture_deferred_free, |
| .sync = synchronize_rcu_busted, |
| .exp_sync = synchronize_rcu_busted, |
| .call = call_rcu_busted, |
| .cb_barrier = NULL, |
| .fqs = NULL, |
| .stats = NULL, |
| .irq_capable = 1, |
| .name = "busted" |
| }; |
| |
| /* |
| * Definitions for srcu torture testing. |
| */ |
| |
| DEFINE_STATIC_SRCU(srcu_ctl); |
| static struct srcu_struct srcu_ctld; |
| static struct srcu_struct *srcu_ctlp = &srcu_ctl; |
| |
| static int srcu_torture_read_lock(void) __acquires(srcu_ctlp) |
| { |
| return srcu_read_lock(srcu_ctlp); |
| } |
| |
| static void |
| srcu_read_delay(struct torture_random_state *rrsp, struct rt_read_seg *rtrsp) |
| { |
| long delay; |
| const long uspertick = 1000000 / HZ; |
| const long longdelay = 10; |
| |
| /* We want there to be long-running readers, but not all the time. */ |
| |
| delay = torture_random(rrsp) % |
| (nrealreaders * 2 * longdelay * uspertick); |
| if (!delay && in_task()) { |
| schedule_timeout_interruptible(longdelay); |
| rtrsp->rt_delay_jiffies = longdelay; |
| } else { |
| rcu_read_delay(rrsp, rtrsp); |
| } |
| } |
| |
| static void srcu_torture_read_unlock(int idx) __releases(srcu_ctlp) |
| { |
| srcu_read_unlock(srcu_ctlp, idx); |
| } |
| |
| static int torture_srcu_read_lock_held(void) |
| { |
| return srcu_read_lock_held(srcu_ctlp); |
| } |
| |
| static unsigned long srcu_torture_completed(void) |
| { |
| return srcu_batches_completed(srcu_ctlp); |
| } |
| |
| static void srcu_torture_deferred_free(struct rcu_torture *rp) |
| { |
| call_srcu(srcu_ctlp, &rp->rtort_rcu, rcu_torture_cb); |
| } |
| |
| static void srcu_torture_synchronize(void) |
| { |
| synchronize_srcu(srcu_ctlp); |
| } |
| |
| static unsigned long srcu_torture_get_gp_state(void) |
| { |
| return get_state_synchronize_srcu(srcu_ctlp); |
| } |
| |
| static unsigned long srcu_torture_start_gp_poll(void) |
| { |
| return start_poll_synchronize_srcu(srcu_ctlp); |
| } |
| |
| static bool srcu_torture_poll_gp_state(unsigned long oldstate) |
| { |
| return poll_state_synchronize_srcu(srcu_ctlp, oldstate); |
| } |
| |
| static void srcu_torture_call(struct rcu_head *head, |
| rcu_callback_t func) |
| { |
| call_srcu(srcu_ctlp, head, func); |
| } |
| |
| static void srcu_torture_barrier(void) |
| { |
| srcu_barrier(srcu_ctlp); |
| } |
| |
| static void srcu_torture_stats(void) |
| { |
| srcu_torture_stats_print(srcu_ctlp, torture_type, TORTURE_FLAG); |
| } |
| |
| static void srcu_torture_synchronize_expedited(void) |
| { |
| synchronize_srcu_expedited(srcu_ctlp); |
| } |
| |
| static struct rcu_torture_ops srcu_ops = { |
| .ttype = SRCU_FLAVOR, |
| .init = rcu_sync_torture_init, |
| .readlock = srcu_torture_read_lock, |
| .read_delay = srcu_read_delay, |
| .readunlock = srcu_torture_read_unlock, |
| .readlock_held = torture_srcu_read_lock_held, |
| .get_gp_seq = srcu_torture_completed, |
| .deferred_free = srcu_torture_deferred_free, |
| .sync = srcu_torture_synchronize, |
| .exp_sync = srcu_torture_synchronize_expedited, |
| .get_gp_state = srcu_torture_get_gp_state, |
| .start_gp_poll = srcu_torture_start_gp_poll, |
| .poll_gp_state = srcu_torture_poll_gp_state, |
| .call = srcu_torture_call, |
| .cb_barrier = srcu_torture_barrier, |
| .stats = srcu_torture_stats, |
| .cbflood_max = 50000, |
| .irq_capable = 1, |
| .no_pi_lock = IS_ENABLED(CONFIG_TINY_SRCU), |
| .name = "srcu" |
| }; |
| |
| static void srcu_torture_init(void) |
| { |
| rcu_sync_torture_init(); |
| WARN_ON(init_srcu_struct(&srcu_ctld)); |
| srcu_ctlp = &srcu_ctld; |
| } |
| |
| static void srcu_torture_cleanup(void) |
| { |
| cleanup_srcu_struct(&srcu_ctld); |
| srcu_ctlp = &srcu_ctl; /* In case of a later rcutorture run. */ |
| } |
| |
| /* As above, but dynamically allocated. */ |
| static struct rcu_torture_ops srcud_ops = { |
| .ttype = SRCU_FLAVOR, |
| .init = srcu_torture_init, |
| .cleanup = srcu_torture_cleanup, |
| .readlock = srcu_torture_read_lock, |
| .read_delay = srcu_read_delay, |
| .readunlock = srcu_torture_read_unlock, |
| .readlock_held = torture_srcu_read_lock_held, |
| .get_gp_seq = srcu_torture_completed, |
| .deferred_free = srcu_torture_deferred_free, |
| .sync = srcu_torture_synchronize, |
| .exp_sync = srcu_torture_synchronize_expedited, |
| .call = srcu_torture_call, |
| .cb_barrier = srcu_torture_barrier, |
| .stats = srcu_torture_stats, |
| .cbflood_max = 50000, |
| .irq_capable = 1, |
| .no_pi_lock = IS_ENABLED(CONFIG_TINY_SRCU), |
| .name = "srcud" |
| }; |
| |
| /* As above, but broken due to inappropriate reader extension. */ |
| static struct rcu_torture_ops busted_srcud_ops = { |
| .ttype = SRCU_FLAVOR, |
| .init = srcu_torture_init, |
| .cleanup = srcu_torture_cleanup, |
| .readlock = srcu_torture_read_lock, |
| .read_delay = rcu_read_delay, |
| .readunlock = srcu_torture_read_unlock, |
| .readlock_held = torture_srcu_read_lock_held, |
| .get_gp_seq = srcu_torture_completed, |
| .deferred_free = srcu_torture_deferred_free, |
| .sync = srcu_torture_synchronize, |
| .exp_sync = srcu_torture_synchronize_expedited, |
| .call = srcu_torture_call, |
| .cb_barrier = srcu_torture_barrier, |
| .stats = srcu_torture_stats, |
| .irq_capable = 1, |
| .no_pi_lock = IS_ENABLED(CONFIG_TINY_SRCU), |
| .extendables = RCUTORTURE_MAX_EXTEND, |
| .name = "busted_srcud" |
| }; |
| |
| /* |
| * Definitions for trivial CONFIG_PREEMPT=n-only torture testing. |
| * This implementation does not necessarily work well with CPU hotplug. |
| */ |
| |
| static void synchronize_rcu_trivial(void) |
| { |
| int cpu; |
| |
| for_each_online_cpu(cpu) { |
| rcutorture_sched_setaffinity(current->pid, cpumask_of(cpu)); |
| WARN_ON_ONCE(raw_smp_processor_id() != cpu); |
| } |
| } |
| |
| static int rcu_torture_read_lock_trivial(void) __acquires(RCU) |
| { |
| preempt_disable(); |
| return 0; |
| } |
| |
| static void rcu_torture_read_unlock_trivial(int idx) __releases(RCU) |
| { |
| preempt_enable(); |
| } |
| |
| static struct rcu_torture_ops trivial_ops = { |
| .ttype = RCU_TRIVIAL_FLAVOR, |
| .init = rcu_sync_torture_init, |
| .readlock = rcu_torture_read_lock_trivial, |
| .read_delay = rcu_read_delay, /* just reuse rcu's version. */ |
| .readunlock = rcu_torture_read_unlock_trivial, |
| .readlock_held = torture_readlock_not_held, |
| .get_gp_seq = rcu_no_completed, |
| .sync = synchronize_rcu_trivial, |
| .exp_sync = synchronize_rcu_trivial, |
| .fqs = NULL, |
| .stats = NULL, |
| .irq_capable = 1, |
| .name = "trivial" |
| }; |
| |
| #ifdef CONFIG_TASKS_RCU |
| |
| /* |
| * Definitions for RCU-tasks torture testing. |
| */ |
| |
| static int tasks_torture_read_lock(void) |
| { |
| return 0; |
| } |
| |
| static void tasks_torture_read_unlock(int idx) |
| { |
| } |
| |
| static void rcu_tasks_torture_deferred_free(struct rcu_torture *p) |
| { |
| call_rcu_tasks(&p->rtort_rcu, rcu_torture_cb); |
| } |
| |
| static void synchronize_rcu_mult_test(void) |
| { |
| synchronize_rcu_mult(call_rcu_tasks, call_rcu); |
| } |
| |
| static struct rcu_torture_ops tasks_ops = { |
| .ttype = RCU_TASKS_FLAVOR, |
| .init = rcu_sync_torture_init, |
| .readlock = tasks_torture_read_lock, |
| .read_delay = rcu_read_delay, /* just reuse rcu's version. */ |
| .readunlock = tasks_torture_read_unlock, |
| .get_gp_seq = rcu_no_completed, |
| .deferred_free = rcu_tasks_torture_deferred_free, |
| .sync = synchronize_rcu_tasks, |
| .exp_sync = synchronize_rcu_mult_test, |
| .call = call_rcu_tasks, |
| .cb_barrier = rcu_barrier_tasks, |
| .gp_kthread_dbg = show_rcu_tasks_classic_gp_kthread, |
| .fqs = NULL, |
| .stats = NULL, |
| .irq_capable = 1, |
| .slow_gps = 1, |
| .name = "tasks" |
| }; |
| |
| #define TASKS_OPS &tasks_ops, |
| |
| #else // #ifdef CONFIG_TASKS_RCU |
| |
| #define TASKS_OPS |
| |
| #endif // #else #ifdef CONFIG_TASKS_RCU |
| |
| |
| #ifdef CONFIG_TASKS_RUDE_RCU |
| |
| /* |
| * Definitions for rude RCU-tasks torture testing. |
| */ |
| |
| static void rcu_tasks_rude_torture_deferred_free(struct rcu_torture *p) |
| { |
| call_rcu_tasks_rude(&p->rtort_rcu, rcu_torture_cb); |
| } |
| |
| static struct rcu_torture_ops tasks_rude_ops = { |
| .ttype = RCU_TASKS_RUDE_FLAVOR, |
| .init = rcu_sync_torture_init, |
| .readlock = rcu_torture_read_lock_trivial, |
| .read_delay = rcu_read_delay, /* just reuse rcu's version. */ |
| .readunlock = rcu_torture_read_unlock_trivial, |
| .get_gp_seq = rcu_no_completed, |
| .deferred_free = rcu_tasks_rude_torture_deferred_free, |
| .sync = synchronize_rcu_tasks_rude, |
| .exp_sync = synchronize_rcu_tasks_rude, |
| .call = call_rcu_tasks_rude, |
| .cb_barrier = rcu_barrier_tasks_rude, |
| .gp_kthread_dbg = show_rcu_tasks_rude_gp_kthread, |
| .cbflood_max = 50000, |
| .fqs = NULL, |
| .stats = NULL, |
| .irq_capable = 1, |
| .name = "tasks-rude" |
| }; |
| |
| #define TASKS_RUDE_OPS &tasks_rude_ops, |
| |
| #else // #ifdef CONFIG_TASKS_RUDE_RCU |
| |
| #define TASKS_RUDE_OPS |
| |
| #endif // #else #ifdef CONFIG_TASKS_RUDE_RCU |
| |
| |
| #ifdef CONFIG_TASKS_TRACE_RCU |
| |
| /* |
| * Definitions for tracing RCU-tasks torture testing. |
| */ |
| |
| static int tasks_tracing_torture_read_lock(void) |
| { |
| rcu_read_lock_trace(); |
| return 0; |
| } |
| |
| static void tasks_tracing_torture_read_unlock(int idx) |
| { |
| rcu_read_unlock_trace(); |
| } |
| |
| static void rcu_tasks_tracing_torture_deferred_free(struct rcu_torture *p) |
| { |
| call_rcu_tasks_trace(&p->rtort_rcu, rcu_torture_cb); |
| } |
| |
| static struct rcu_torture_ops tasks_tracing_ops = { |
| .ttype = RCU_TASKS_TRACING_FLAVOR, |
| .init = rcu_sync_torture_init, |
| .readlock = tasks_tracing_torture_read_lock, |
| .read_delay = srcu_read_delay, /* just reuse srcu's version. */ |
| .readunlock = tasks_tracing_torture_read_unlock, |
| .readlock_held = rcu_read_lock_trace_held, |
| .get_gp_seq = rcu_no_completed, |
| .deferred_free = rcu_tasks_tracing_torture_deferred_free, |
| .sync = synchronize_rcu_tasks_trace, |
| .exp_sync = synchronize_rcu_tasks_trace, |
| .call = call_rcu_tasks_trace, |
| .cb_barrier = rcu_barrier_tasks_trace, |
| .gp_kthread_dbg = show_rcu_tasks_trace_gp_kthread, |
| .cbflood_max = 50000, |
| .fqs = NULL, |
| .stats = NULL, |
| .irq_capable = 1, |
| .slow_gps = 1, |
| .name = "tasks-tracing" |
| }; |
| |
| #define TASKS_TRACING_OPS &tasks_tracing_ops, |
| |
| #else // #ifdef CONFIG_TASKS_TRACE_RCU |
| |
| #define TASKS_TRACING_OPS |
| |
| #endif // #else #ifdef CONFIG_TASKS_TRACE_RCU |
| |
| |
| static unsigned long rcutorture_seq_diff(unsigned long new, unsigned long old) |
| { |
| if (!cur_ops->gp_diff) |
| return new - old; |
| return cur_ops->gp_diff(new, old); |
| } |
| |
| /* |
| * RCU torture priority-boost testing. Runs one real-time thread per |
| * CPU for moderate bursts, repeatedly starting grace periods and waiting |
| * for them to complete. If a given grace period takes too long, we assume |
| * that priority inversion has occurred. |
| */ |
| |
| static int old_rt_runtime = -1; |
| |
| static void rcu_torture_disable_rt_throttle(void) |
| { |
| /* |
| * Disable RT throttling so that rcutorture's boost threads don't get |
| * throttled. Only possible if rcutorture is built-in otherwise the |
| * user should manually do this by setting the sched_rt_period_us and |
| * sched_rt_runtime sysctls. |
| */ |
| if (!IS_BUILTIN(CONFIG_RCU_TORTURE_TEST) || old_rt_runtime != -1) |
| return; |
| |
| old_rt_runtime = sysctl_sched_rt_runtime; |
| sysctl_sched_rt_runtime = -1; |
| } |
| |
| static void rcu_torture_enable_rt_throttle(void) |
| { |
| if (!IS_BUILTIN(CONFIG_RCU_TORTURE_TEST) || old_rt_runtime == -1) |
| return; |
| |
| sysctl_sched_rt_runtime = old_rt_runtime; |
| old_rt_runtime = -1; |
| } |
| |
| static bool rcu_torture_boost_failed(unsigned long gp_state, unsigned long *start) |
| { |
| int cpu; |
| static int dbg_done; |
| unsigned long end = jiffies; |
| bool gp_done; |
| unsigned long j; |
| static unsigned long last_persist; |
| unsigned long lp; |
| unsigned long mininterval = test_boost_duration * HZ - HZ / 2; |
| |
| if (end - *start > mininterval) { |
| // Recheck after checking time to avoid false positives. |
| smp_mb(); // Time check before grace-period check. |
| if (cur_ops->poll_gp_state(gp_state)) |
| return false; // passed, though perhaps just barely |
| if (cur_ops->check_boost_failed && !cur_ops->check_boost_failed(gp_state, &cpu)) { |
| // At most one persisted message per boost test. |
| j = jiffies; |
| lp = READ_ONCE(last_persist); |
| if (time_after(j, lp + mininterval) && cmpxchg(&last_persist, lp, j) == lp) |
| pr_info("Boost inversion persisted: No QS from CPU %d\n", cpu); |
| return false; // passed on a technicality |
| } |
| VERBOSE_TOROUT_STRING("rcu_torture_boost boosting failed"); |
| n_rcu_torture_boost_failure++; |
| if (!xchg(&dbg_done, 1) && cur_ops->gp_kthread_dbg) { |
| pr_info("Boost inversion thread ->rt_priority %u gp_state %lu jiffies %lu\n", |
| current->rt_priority, gp_state, end - *start); |
| cur_ops->gp_kthread_dbg(); |
| // Recheck after print to flag grace period ending during splat. |
| gp_done = cur_ops->poll_gp_state(gp_state); |
| pr_info("Boost inversion: GP %lu %s.\n", gp_state, |
| gp_done ? "ended already" : "still pending"); |
| |
| } |
| |
| return true; // failed |
| } else if (cur_ops->check_boost_failed && !cur_ops->check_boost_failed(gp_state, NULL)) { |
| *start = jiffies; |
| } |
| |
| return false; // passed |
| } |
| |
| static int rcu_torture_boost(void *arg) |
| { |
| unsigned long endtime; |
| unsigned long gp_state; |
| unsigned long gp_state_time; |
| unsigned long oldstarttime; |
| |
| VERBOSE_TOROUT_STRING("rcu_torture_boost started"); |
| |
| /* Set real-time priority. */ |
| sched_set_fifo_low(current); |
| |
| /* Each pass through the following loop does one boost-test cycle. */ |
| do { |
| bool failed = false; // Test failed already in this test interval |
| bool gp_initiated = false; |
| |
| if (kthread_should_stop()) |
| goto checkwait; |
| |
| /* Wait for the next test interval. */ |
| oldstarttime = READ_ONCE(boost_starttime); |
| while (time_before(jiffies, oldstarttime)) { |
| schedule_timeout_interruptible(oldstarttime - jiffies); |
| if (stutter_wait("rcu_torture_boost")) |
| sched_set_fifo_low(current); |
| if (torture_must_stop()) |
| goto checkwait; |
| } |
| |
| // Do one boost-test interval. |
| endtime = oldstarttime + test_boost_duration * HZ; |
| while (time_before(jiffies, endtime)) { |
| // Has current GP gone too long? |
| if (gp_initiated && !failed && !cur_ops->poll_gp_state(gp_state)) |
| failed = rcu_torture_boost_failed(gp_state, &gp_state_time); |
| // If we don't have a grace period in flight, start one. |
| if (!gp_initiated || cur_ops->poll_gp_state(gp_state)) { |
| gp_state = cur_ops->start_gp_poll(); |
| gp_initiated = true; |
| gp_state_time = jiffies; |
| } |
| if (stutter_wait("rcu_torture_boost")) { |
| sched_set_fifo_low(current); |
| // If the grace period already ended, |
| // we don't know when that happened, so |
| // start over. |
| if (cur_ops->poll_gp_state(gp_state)) |
| gp_initiated = false; |
| } |
| if (torture_must_stop()) |
| goto checkwait; |
| } |
| |
| // In case the grace period extended beyond the end of the loop. |
| if (gp_initiated && !failed && !cur_ops->poll_gp_state(gp_state)) |
| rcu_torture_boost_failed(gp_state, &gp_state_time); |
| |
| /* |
| * Set the start time of the next test interval. |
| * Yes, this is vulnerable to long delays, but such |
| * delays simply cause a false negative for the next |
| * interval. Besides, we are running at RT priority, |
| * so delays should be relatively rare. |
| */ |
| while (oldstarttime == READ_ONCE(boost_starttime) && !kthread_should_stop()) { |
| if (mutex_trylock(&boost_mutex)) { |
| if (oldstarttime == boost_starttime) { |
| WRITE_ONCE(boost_starttime, |
| jiffies + test_boost_interval * HZ); |
| n_rcu_torture_boosts++; |
| } |
| mutex_unlock(&boost_mutex); |
| break; |
| } |
| schedule_timeout_uninterruptible(1); |
| } |
| |
| /* Go do the stutter. */ |
| checkwait: if (stutter_wait("rcu_torture_boost")) |
| sched_set_fifo_low(current); |
| } while (!torture_must_stop()); |
| |
| /* Clean up and exit. */ |
| while (!kthread_should_stop()) { |
| torture_shutdown_absorb("rcu_torture_boost"); |
| schedule_timeout_uninterruptible(1); |
| } |
| torture_kthread_stopping("rcu_torture_boost"); |
| return 0; |
| } |
| |
| /* |
| * RCU torture force-quiescent-state kthread. Repeatedly induces |
| * bursts of calls to force_quiescent_state(), increasing the probability |
| * of occurrence of some important types of race conditions. |
| */ |
| static int |
| rcu_torture_fqs(void *arg) |
| { |
| unsigned long fqs_resume_time; |
| int fqs_burst_remaining; |
| int oldnice = task_nice(current); |
| |
| VERBOSE_TOROUT_STRING("rcu_torture_fqs task started"); |
| do { |
| fqs_resume_time = jiffies + fqs_stutter * HZ; |
| while (time_before(jiffies, fqs_resume_time) && |
| !kthread_should_stop()) { |
| schedule_timeout_interruptible(1); |
| } |
| fqs_burst_remaining = fqs_duration; |
| while (fqs_burst_remaining > 0 && |
| !kthread_should_stop()) { |
| cur_ops->fqs(); |
| udelay(fqs_holdoff); |
| fqs_burst_remaining -= fqs_holdoff; |
| } |
| if (stutter_wait("rcu_torture_fqs")) |
| sched_set_normal(current, oldnice); |
| } while (!torture_must_stop()); |
| torture_kthread_stopping("rcu_torture_fqs"); |
| return 0; |
| } |
| |
| // Used by writers to randomly choose from the available grace-period primitives. |
| static int synctype[ARRAY_SIZE(rcu_torture_writer_state_names)] = { }; |
| static int nsynctypes; |
| |
| /* |
| * Determine which grace-period primitives are available. |
| */ |
| static void rcu_torture_write_types(void) |
| { |
| bool gp_cond1 = gp_cond, gp_cond_exp1 = gp_cond_exp, gp_exp1 = gp_exp; |
| bool gp_poll_exp1 = gp_poll_exp, gp_normal1 = gp_normal, gp_poll1 = gp_poll; |
| bool gp_sync1 = gp_sync; |
| |
| /* Initialize synctype[] array. If none set, take default. */ |
| if (!gp_cond1 && !gp_cond_exp1 && !gp_exp1 && !gp_poll_exp && |
| !gp_normal1 && !gp_poll1 && !gp_sync1) |
| gp_cond1 = gp_cond_exp1 = gp_exp1 = gp_poll_exp1 = |
| gp_normal1 = gp_poll1 = gp_sync1 = true; |
| if (gp_cond1 && cur_ops->get_gp_state && cur_ops->cond_sync) { |
| synctype[nsynctypes++] = RTWS_COND_GET; |
| pr_info("%s: Testing conditional GPs.\n", __func__); |
| } else if (gp_cond && (!cur_ops->get_gp_state || !cur_ops->cond_sync)) { |
| pr_alert("%s: gp_cond without primitives.\n", __func__); |
| } |
| if (gp_cond_exp1 && cur_ops->get_gp_state_exp && cur_ops->cond_sync_exp) { |
| synctype[nsynctypes++] = RTWS_COND_GET_EXP; |
| pr_info("%s: Testing conditional expedited GPs.\n", __func__); |
| } else if (gp_cond_exp && (!cur_ops->get_gp_state_exp || !cur_ops->cond_sync_exp)) { |
| pr_alert("%s: gp_cond_exp without primitives.\n", __func__); |
| } |
| if (gp_exp1 && cur_ops->exp_sync) { |
| synctype[nsynctypes++] = RTWS_EXP_SYNC; |
| pr_info("%s: Testing expedited GPs.\n", __func__); |
| } else if (gp_exp && !cur_ops->exp_sync) { |
| pr_alert("%s: gp_exp without primitives.\n", __func__); |
| } |
| if (gp_normal1 && cur_ops->deferred_free) { |
| synctype[nsynctypes++] = RTWS_DEF_FREE; |
| pr_info("%s: Testing asynchronous GPs.\n", __func__); |
| } else if (gp_normal && !cur_ops->deferred_free) { |
| pr_alert("%s: gp_normal without primitives.\n", __func__); |
| } |
| if (gp_poll1 && cur_ops->start_gp_poll && cur_ops->poll_gp_state) { |
| synctype[nsynctypes++] = RTWS_POLL_GET; |
| pr_info("%s: Testing polling GPs.\n", __func__); |
| } else if (gp_poll && (!cur_ops->start_gp_poll || !cur_ops->poll_gp_state)) { |
| pr_alert("%s: gp_poll without primitives.\n", __func__); |
| } |
| if (gp_poll_exp1 && cur_ops->start_gp_poll_exp && cur_ops->poll_gp_state_exp) { |
| synctype[nsynctypes++] = RTWS_POLL_GET_EXP; |
| pr_info("%s: Testing polling expedited GPs.\n", __func__); |
| } else if (gp_poll_exp && (!cur_ops->start_gp_poll_exp || !cur_ops->poll_gp_state_exp)) { |
| pr_alert("%s: gp_poll_exp without primitives.\n", __func__); |
| } |
| if (gp_sync1 && cur_ops->sync) { |
| synctype[nsynctypes++] = RTWS_SYNC; |
| pr_info("%s: Testing normal GPs.\n", __func__); |
| } else if (gp_sync && !cur_ops->sync) { |
| pr_alert("%s: gp_sync without primitives.\n", __func__); |
| } |
| } |
| |
| /* |
| * RCU torture writer kthread. Repeatedly substitutes a new structure |
| * for that pointed to by rcu_torture_current, freeing the old structure |
| * after a series of grace periods (the "pipeline"). |
| */ |
| static int |
| rcu_torture_writer(void *arg) |
| { |
| bool boot_ended; |
| bool can_expedite = !rcu_gp_is_expedited() && !rcu_gp_is_normal(); |
| unsigned long cookie; |
| int expediting = 0; |
| unsigned long gp_snap; |
| int i; |
| int idx; |
| int oldnice = task_nice(current); |
| struct rcu_torture *rp; |
| struct rcu_torture *old_rp; |
| static DEFINE_TORTURE_RANDOM(rand); |
| bool stutter_waited; |
| |
| VERBOSE_TOROUT_STRING("rcu_torture_writer task started"); |
| if (!can_expedite) |
| pr_alert("%s" TORTURE_FLAG |
| " GP expediting controlled from boot/sysfs for %s.\n", |
| torture_type, cur_ops->name); |
| if (WARN_ONCE(nsynctypes == 0, |
| "%s: No update-side primitives.\n", __func__)) { |
| /* |
| * No updates primitives, so don't try updating. |
| * The resulting test won't be testing much, hence the |
| * above WARN_ONCE(). |
| */ |
| rcu_torture_writer_state = RTWS_STOPPING; |
| torture_kthread_stopping("rcu_torture_writer"); |
| return 0; |
| } |
| |
| do { |
| rcu_torture_writer_state = RTWS_FIXED_DELAY; |
| torture_hrtimeout_us(500, 1000, &rand); |
| rp = rcu_torture_alloc(); |
| if (rp == NULL) |
| continue; |
| rp->rtort_pipe_count = 0; |
| rcu_torture_writer_state = RTWS_DELAY; |
| udelay(torture_random(&rand) & 0x3ff); |
| rcu_torture_writer_state = RTWS_REPLACE; |
| old_rp = rcu_dereference_check(rcu_torture_current, |
| current == writer_task); |
| rp->rtort_mbtest = 1; |
| rcu_assign_pointer(rcu_torture_current, rp); |
| smp_wmb(); /* Mods to old_rp must follow rcu_assign_pointer() */ |
| if (old_rp) { |
| i = old_rp->rtort_pipe_count; |
| if (i > RCU_TORTURE_PIPE_LEN) |
| i = RCU_TORTURE_PIPE_LEN; |
| atomic_inc(&rcu_torture_wcount[i]); |
| WRITE_ONCE(old_rp->rtort_pipe_count, |
| old_rp->rtort_pipe_count + 1); |
| if (cur_ops->get_gp_state && cur_ops->poll_gp_state) { |
| idx = cur_ops->readlock(); |
| cookie = cur_ops->get_gp_state(); |
| WARN_ONCE(rcu_torture_writer_state != RTWS_DEF_FREE && |
| cur_ops->poll_gp_state(cookie), |
| "%s: Cookie check 1 failed %s(%d) %lu->%lu\n", |
| __func__, |
| rcu_torture_writer_state_getname(), |
| rcu_torture_writer_state, |
| cookie, cur_ops->get_gp_state()); |
| if (cur_ops->get_gp_completed) { |
| cookie = cur_ops->get_gp_completed(); |
| WARN_ON_ONCE(!cur_ops->poll_gp_state(cookie)); |
| } |
| cur_ops->readunlock(idx); |
| } |
| switch (synctype[torture_random(&rand) % nsynctypes]) { |
| case RTWS_DEF_FREE: |
| rcu_torture_writer_state = RTWS_DEF_FREE; |
| cur_ops->deferred_free(old_rp); |
| break; |
| case RTWS_EXP_SYNC: |
| rcu_torture_writer_state = RTWS_EXP_SYNC; |
| if (cur_ops->get_gp_state && cur_ops->poll_gp_state) |
| cookie = cur_ops->get_gp_state(); |
| cur_ops->exp_sync(); |
| cur_ops->exp_sync(); |
| if (cur_ops->get_gp_state && cur_ops->poll_gp_state) |
| WARN_ON_ONCE(!cur_ops->poll_gp_state(cookie)); |
| rcu_torture_pipe_update(old_rp); |
| break; |
| case RTWS_COND_GET: |
| rcu_torture_writer_state = RTWS_COND_GET; |
| gp_snap = cur_ops->get_gp_state(); |
| torture_hrtimeout_jiffies(torture_random(&rand) % 16, &rand); |
| rcu_torture_writer_state = RTWS_COND_SYNC; |
| cur_ops->cond_sync(gp_snap); |
| rcu_torture_pipe_update(old_rp); |
| break; |
| case RTWS_COND_GET_EXP: |
| rcu_torture_writer_state = RTWS_COND_GET_EXP; |
| gp_snap = cur_ops->get_gp_state_exp(); |
| torture_hrtimeout_jiffies(torture_random(&rand) % 16, &rand); |
| rcu_torture_writer_state = RTWS_COND_SYNC_EXP; |
| cur_ops->cond_sync_exp(gp_snap); |
| rcu_torture_pipe_update(old_rp); |
| break; |
| case RTWS_POLL_GET: |
| rcu_torture_writer_state = RTWS_POLL_GET; |
| gp_snap = cur_ops->start_gp_poll(); |
| rcu_torture_writer_state = RTWS_POLL_WAIT; |
| while (!cur_ops->poll_gp_state(gp_snap)) |
| torture_hrtimeout_jiffies(torture_random(&rand) % 16, |
| &rand); |
| rcu_torture_pipe_update(old_rp); |
| break; |
| case RTWS_POLL_GET_EXP: |
| rcu_torture_writer_state = RTWS_POLL_GET_EXP; |
| gp_snap = cur_ops->start_gp_poll_exp(); |
| rcu_torture_writer_state = RTWS_POLL_WAIT_EXP; |
| while (!cur_ops->poll_gp_state_exp(gp_snap)) |
| torture_hrtimeout_jiffies(torture_random(&rand) % 16, |
| &rand); |
| rcu_torture_pipe_update(old_rp); |
| break; |
| case RTWS_SYNC: |
| rcu_torture_writer_state = RTWS_SYNC; |
| if (cur_ops->get_gp_state && cur_ops->poll_gp_state) |
| cookie = cur_ops->get_gp_state(); |
| cur_ops->sync(); |
| cur_ops->sync(); |
| if (cur_ops->get_gp_state && cur_ops->poll_gp_state) |
| WARN_ON_ONCE(!cur_ops->poll_gp_state(cookie)); |
| rcu_torture_pipe_update(old_rp); |
| break; |
| default: |
| WARN_ON_ONCE(1); |
| break; |
| } |
| } |
| WRITE_ONCE(rcu_torture_current_version, |
| rcu_torture_current_version + 1); |
| /* Cycle through nesting levels of rcu_expedite_gp() calls. */ |
| if (can_expedite && |
| !(torture_random(&rand) & 0xff & (!!expediting - 1))) { |
| WARN_ON_ONCE(expediting == 0 && rcu_gp_is_expedited()); |
| if (expediting >= 0) |
| rcu_expedite_gp(); |
| else |
| rcu_unexpedite_gp(); |
| if (++expediting > 3) |
| expediting = -expediting; |
| } else if (!can_expedite) { /* Disabled during boot, recheck. */ |
| can_expedite = !rcu_gp_is_expedited() && |
| !rcu_gp_is_normal(); |
| } |
| rcu_torture_writer_state = RTWS_STUTTER; |
| boot_ended = rcu_inkernel_boot_has_ended(); |
| stutter_waited = stutter_wait("rcu_torture_writer"); |
| if (stutter_waited && |
| !atomic_read(&rcu_fwd_cb_nodelay) && |
| !cur_ops->slow_gps && |
| !torture_must_stop() && |
| boot_ended) |
| for (i = 0; i < ARRAY_SIZE(rcu_tortures); i++) |
| if (list_empty(&rcu_tortures[i].rtort_free) && |
| rcu_access_pointer(rcu_torture_current) != |
| &rcu_tortures[i]) { |
| tracing_off(); |
| WARN(1, "%s: rtort_pipe_count: %d\n", __func__, rcu_tortures[i].rtort_pipe_count); |
| rcu_ftrace_dump(DUMP_ALL); |
| } |
| if (stutter_waited) |
| sched_set_normal(current, oldnice); |
| } while (!torture_must_stop()); |
| rcu_torture_current = NULL; // Let stats task know that we are done. |
| /* Reset expediting back to unexpedited. */ |
| if (expediting > 0) |
| expediting = -expediting; |
| while (can_expedite && expediting++ < 0) |
| rcu_unexpedite_gp(); |
| WARN_ON_ONCE(can_expedite && rcu_gp_is_expedited()); |
| if (!can_expedite) |
| pr_alert("%s" TORTURE_FLAG |
| " Dynamic grace-period expediting was disabled.\n", |
| torture_type); |
| rcu_torture_writer_state = RTWS_STOPPING; |
| torture_kthread_stopping("rcu_torture_writer"); |
| return 0; |
| } |
| |
| /* |
| * RCU torture fake writer kthread. Repeatedly calls sync, with a random |
| * delay between calls. |
| */ |
| static int |
| rcu_torture_fakewriter(void *arg) |
| { |
| unsigned long gp_snap; |
| DEFINE_TORTURE_RANDOM(rand); |
| |
| VERBOSE_TOROUT_STRING("rcu_torture_fakewriter task started"); |
| set_user_nice(current, MAX_NICE); |
| |
| if (WARN_ONCE(nsynctypes == 0, |
| "%s: No update-side primitives.\n", __func__)) { |
| /* |
| * No updates primitives, so don't try updating. |
| * The resulting test won't be testing much, hence the |
| * above WARN_ONCE(). |
| */ |
| torture_kthread_stopping("rcu_torture_fakewriter"); |
| return 0; |
| } |
| |
| do { |
| torture_hrtimeout_jiffies(torture_random(&rand) % 10, &rand); |
| if (cur_ops->cb_barrier != NULL && |
| torture_random(&rand) % (nfakewriters * 8) == 0) { |
| cur_ops->cb_barrier(); |
| } else { |
| switch (synctype[torture_random(&rand) % nsynctypes]) { |
| case RTWS_DEF_FREE: |
| break; |
| case RTWS_EXP_SYNC: |
| cur_ops->exp_sync(); |
| break; |
| case RTWS_COND_GET: |
| gp_snap = cur_ops->get_gp_state(); |
| torture_hrtimeout_jiffies(torture_random(&rand) % 16, &rand); |
| cur_ops->cond_sync(gp_snap); |
| break; |
| case RTWS_COND_GET_EXP: |
| gp_snap = cur_ops->get_gp_state_exp(); |
| torture_hrtimeout_jiffies(torture_random(&rand) % 16, &rand); |
| cur_ops->cond_sync_exp(gp_snap); |
| break; |
| case RTWS_POLL_GET: |
| gp_snap = cur_ops->start_gp_poll(); |
| while (!cur_ops->poll_gp_state(gp_snap)) { |
| torture_hrtimeout_jiffies(torture_random(&rand) % 16, |
| &rand); |
| } |
| break; |
| case RTWS_POLL_GET_EXP: |
| gp_snap = cur_ops->start_gp_poll_exp(); |
| while (!cur_ops->poll_gp_state_exp(gp_snap)) { |
| torture_hrtimeout_jiffies(torture_random(&rand) % 16, |
| &rand); |
| } |
| break; |
| case RTWS_SYNC: |
| cur_ops->sync(); |
| break; |
| default: |
| WARN_ON_ONCE(1); |
| break; |
| } |
| } |
| stutter_wait("rcu_torture_fakewriter"); |
| } while (!torture_must_stop()); |
| |
| torture_kthread_stopping("rcu_torture_fakewriter"); |
| return 0; |
| } |
| |
| static void rcu_torture_timer_cb(struct rcu_head *rhp) |
| { |
| kfree(rhp); |
| } |
| |
| // Set up and carry out testing of RCU's global memory ordering |
| static void rcu_torture_reader_do_mbchk(long myid, struct rcu_torture *rtp, |
| struct torture_random_state *trsp) |
| { |
| unsigned long loops; |
| int noc = torture_num_online_cpus(); |
| int rdrchked; |
| int rdrchker; |
| struct rcu_torture_reader_check *rtrcp; // Me. |
| struct rcu_torture_reader_check *rtrcp_assigner; // Assigned us to do checking. |
| struct rcu_torture_reader_check *rtrcp_chked; // Reader being checked. |
| struct rcu_torture_reader_check *rtrcp_chker; // Reader doing checking when not me. |
| |
| if (myid < 0) |
| return; // Don't try this from timer handlers. |
| |
| // Increment my counter. |
| rtrcp = &rcu_torture_reader_mbchk[myid]; |
| WRITE_ONCE(rtrcp->rtc_myloops, rtrcp->rtc_myloops + 1); |
| |
| // Attempt to assign someone else some checking work. |
| rdrchked = torture_random(trsp) % nrealreaders; |
| rtrcp_chked = &rcu_torture_reader_mbchk[rdrchked]; |
| rdrchker = torture_random(trsp) % nrealreaders; |
| rtrcp_chker = &rcu_torture_reader_mbchk[rdrchker]; |
| if (rdrchked != myid && rdrchked != rdrchker && noc >= rdrchked && noc >= rdrchker && |
| smp_load_acquire(&rtrcp->rtc_chkrdr) < 0 && // Pairs with smp_store_release below. |
| !READ_ONCE(rtp->rtort_chkp) && |
| !smp_load_acquire(&rtrcp_chker->rtc_assigner)) { // Pairs with smp_store_release below. |
| rtrcp->rtc_chkloops = READ_ONCE(rtrcp_chked->rtc_myloops); |
| WARN_ON_ONCE(rtrcp->rtc_chkrdr >= 0); |
| rtrcp->rtc_chkrdr = rdrchked; |
| WARN_ON_ONCE(rtrcp->rtc_ready); // This gets set after the grace period ends. |
| if (cmpxchg_relaxed(&rtrcp_chker->rtc_assigner, NULL, rtrcp) || |
| cmpxchg_relaxed(&rtp->rtort_chkp, NULL, rtrcp)) |
| (void)cmpxchg_relaxed(&rtrcp_chker->rtc_assigner, rtrcp, NULL); // Back out. |
| } |
| |
| // If assigned some completed work, do it! |
| rtrcp_assigner = READ_ONCE(rtrcp->rtc_assigner); |
| if (!rtrcp_assigner || !smp_load_acquire(&rtrcp_assigner->rtc_ready)) |
| return; // No work or work not yet ready. |
| rdrchked = rtrcp_assigner->rtc_chkrdr; |
| if (WARN_ON_ONCE(rdrchked < 0)) |
| return; |
| rtrcp_chked = &rcu_torture_reader_mbchk[rdrchked]; |
| loops = READ_ONCE(rtrcp_chked->rtc_myloops); |
| atomic_inc(&n_rcu_torture_mbchk_tries); |
| if (ULONG_CMP_LT(loops, rtrcp_assigner->rtc_chkloops)) |
| atomic_inc(&n_rcu_torture_mbchk_fail); |
| rtrcp_assigner->rtc_chkloops = loops + ULONG_MAX / 2; |
| rtrcp_assigner->rtc_ready = 0; |
| smp_store_release(&rtrcp->rtc_assigner, NULL); // Someone else can assign us work. |
| smp_store_release(&rtrcp_assigner->rtc_chkrdr, -1); // Assigner can again assign. |
| } |
| |
| /* |
| * Do one extension of an RCU read-side critical section using the |
| * current reader state in readstate (set to zero for initial entry |
| * to extended critical section), set the new state as specified by |
| * newstate (set to zero for final exit from extended critical section), |
| * and random-number-generator state in trsp. If this is neither the |
| * beginning or end of the critical section and if there was actually a |
| * change, do a ->read_delay(). |
| */ |
| static void rcutorture_one_extend(int *readstate, int newstate, |
| struct torture_random_state *trsp, |
| struct rt_read_seg *rtrsp) |
| { |
| unsigned long flags; |
| int idxnew1 = -1; |
| int idxnew2 = -1; |
| int idxold1 = *readstate; |
| int idxold2 = idxold1; |
| int statesnew = ~*readstate & newstate; |
| int statesold = *readstate & ~newstate; |
| |
| WARN_ON_ONCE(idxold2 < 0); |
| WARN_ON_ONCE((idxold2 >> RCUTORTURE_RDR_SHIFT_2) > 1); |
| rtrsp->rt_readstate = 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_SCHED) |
| rcu_read_lock_sched(); |
| if (statesnew & RCUTORTURE_RDR_RCU_1) |
| idxnew1 = (cur_ops->readlock() & 0x1) << RCUTORTURE_RDR_SHIFT_1; |
| if (statesnew & RCUTORTURE_RDR_RCU_2) |
| idxnew2 = (cur_ops->readlock() & 0x1) << RCUTORTURE_RDR_SHIFT_2; |
| |
| /* |
| * 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_PREEMPT) |
| preempt_enable(); |
| 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_2) { |
| cur_ops->readunlock((idxold2 >> RCUTORTURE_RDR_SHIFT_2) & 0x1); |
| WARN_ON_ONCE(idxnew2 != -1); |
| idxold2 = 0; |
| } |
| if (statesold & RCUTORTURE_RDR_RCU_1) { |
| bool lockit; |
| |
| lockit = !cur_ops->no_pi_lock && !statesnew && !(torture_random(trsp) & 0xffff); |
| if (lockit) |
| raw_spin_lock_irqsave(¤t->pi_lock, flags); |
| cur_ops->readunlock((idxold1 >> RCUTORTURE_RDR_SHIFT_1) & 0x1); |
| WARN_ON_ONCE(idxnew1 != -1); |
| idxold1 = 0; |
| if (lockit) |
| raw_spin_unlock_irqrestore(¤t->pi_lock, flags); |
| } |
| |
| /* Delay if neither beginning nor end and there was a change. */ |
| if ((statesnew || statesold) && *readstate && newstate) |
| cur_ops->read_delay(trsp, rtrsp); |
| |
| /* Update the reader state. */ |
| if (idxnew1 == -1) |
| idxnew1 = idxold1 & RCUTORTURE_RDR_MASK_1; |
| WARN_ON_ONCE(idxnew1 < 0); |
| if (WARN_ON_ONCE((idxnew1 >> RCUTORTURE_RDR_SHIFT_1) > 1)) |
| pr_info("Unexpected idxnew1 value of %#x\n", idxnew1); |
| if (idxnew2 == -1) |
| idxnew2 = idxold2 & RCUTORTURE_RDR_MASK_2; |
| WARN_ON_ONCE(idxnew2 < 0); |
| WARN_ON_ONCE((idxnew2 >> RCUTORTURE_RDR_SHIFT_2) > 1); |
| *readstate = idxnew1 | idxnew2 | newstate; |
| WARN_ON_ONCE(*readstate < 0); |
| if (WARN_ON_ONCE((*readstate >> RCUTORTURE_RDR_SHIFT_2) > 1)) |
| pr_info("Unexpected idxnew2 value of %#x\n", idxnew2); |
| } |
| |
| /* Return the biggest extendables mask given current RCU and boot parameters. */ |
| static int rcutorture_extend_mask_max(void) |
| { |
| int mask; |
| |
| WARN_ON_ONCE(extendables & ~RCUTORTURE_MAX_EXTEND); |
| mask = extendables & RCUTORTURE_MAX_EXTEND & cur_ops->extendables; |
| mask = mask | RCUTORTURE_RDR_RCU_1 | RCUTORTURE_RDR_RCU_2; |
| return mask; |
| } |
| |
| /* Return a random protection state mask, but with at least one bit set. */ |
| static int |
| 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_1); |
| /* Mostly only one bit (need preemption!), sometimes lots of bits. */ |
| if (!(randmask1 & 0x7)) |
| mask = mask & randmask2; |
| else |
| mask = mask & (1 << (randmask2 % RCUTORTURE_RDR_NBITS)); |
| |
| // Can't have nested RCU reader without outer RCU reader. |
| if (!(mask & RCUTORTURE_RDR_RCU_1) && (mask & RCUTORTURE_RDR_RCU_2)) { |
| if (oldmask & RCUTORTURE_RDR_RCU_1) |
| mask &= ~RCUTORTURE_RDR_RCU_2; |
| else |
| mask |= RCUTORTURE_RDR_RCU_1; |
| } |
| |
| /* |
| * 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_1; |
| } |
| |
| /* |
| * Do a randomly selected number of extensions of an existing RCU read-side |
| * critical section. |
| */ |
| static struct rt_read_seg * |
| rcutorture_loop_extend(int *readstate, struct torture_random_state *trsp, |
| struct rt_read_seg *rtrsp) |
| { |
| int i; |
| int j; |
| int mask = rcutorture_extend_mask_max(); |
| |
| WARN_ON_ONCE(!*readstate); /* -Existing- RCU read-side critsect! */ |
| if (!((mask - 1) & mask)) |
| return rtrsp; /* Current RCU reader not extendable. */ |
| /* Bias towards larger numbers of loops. */ |
| i = (torture_random(trsp) >> 3); |
| i = ((i | (i >> 3)) & RCUTORTURE_RDR_MAX_LOOPS) + 1; |
| for (j = 0; j < i; j++) { |
| mask = rcutorture_extend_mask(*readstate, trsp); |
| rcutorture_one_extend(readstate, mask, trsp, &rtrsp[j]); |
| } |
| return &rtrsp[j]; |
| } |
| |
| /* |
| * Do one read-side critical section, returning false if there was |
| * no data to read. Can be invoked both from process context and |
| * from a timer handler. |
| */ |
| static bool rcu_torture_one_read(struct torture_random_state *trsp, long myid) |
| { |
| unsigned long cookie; |
| int i; |
| unsigned long started; |
| unsigned long completed; |
| int newstate; |
| struct rcu_torture *p; |
| int pipe_count; |
| int readstate = 0; |
| struct rt_read_seg rtseg[RCUTORTURE_RDR_MAX_SEGS] = { { 0 } }; |
| struct rt_read_seg *rtrsp = &rtseg[0]; |
| struct rt_read_seg *rtrsp1; |
| unsigned long long ts; |
| |
| WARN_ON_ONCE(!rcu_is_watching()); |
| newstate = rcutorture_extend_mask(readstate, trsp); |
| rcutorture_one_extend(&readstate, newstate, trsp, rtrsp++); |
| if (cur_ops->get_gp_state && cur_ops->poll_gp_state) |
| cookie = cur_ops->get_gp_state(); |
| started = cur_ops->get_gp_seq(); |
| ts = rcu_trace_clock_local(); |
| p = rcu_dereference_check(rcu_torture_current, |
| !cur_ops->readlock_held || cur_ops->readlock_held()); |
| if (p == NULL) { |
| /* Wait for rcu_torture_writer to get underway */ |
| rcutorture_one_extend(&readstate, 0, trsp, rtrsp); |
| return false; |
| } |
| if (p->rtort_mbtest == 0) |
| atomic_inc(&n_rcu_torture_mberror); |
| rcu_torture_reader_do_mbchk(myid, p, trsp); |
| rtrsp = rcutorture_loop_extend(&readstate, trsp, rtrsp); |
| preempt_disable(); |
| pipe_count = READ_ONCE(p->rtort_pipe_count); |
| if (pipe_count > RCU_TORTURE_PIPE_LEN) { |
| /* Should not happen, but... */ |
| pipe_count = RCU_TORTURE_PIPE_LEN; |
| } |
| completed = cur_ops->get_gp_seq(); |
| if (pipe_count > 1) { |
| do_trace_rcu_torture_read(cur_ops->name, &p->rtort_rcu, |
| ts, started, completed); |
| rcu_ftrace_dump(DUMP_ALL); |
| } |
| __this_cpu_inc(rcu_torture_count[pipe_count]); |
| completed = rcutorture_seq_diff(completed, started); |
| if (completed > RCU_TORTURE_PIPE_LEN) { |
| /* Should not happen, but... */ |
| completed = RCU_TORTURE_PIPE_LEN; |
| } |
| __this_cpu_inc(rcu_torture_batch[completed]); |
| preempt_enable(); |
| if (cur_ops->get_gp_state && cur_ops->poll_gp_state) |
| WARN_ONCE(cur_ops->poll_gp_state(cookie), |
| "%s: Cookie check 2 failed %s(%d) %lu->%lu\n", |
| __func__, |
| rcu_torture_writer_state_getname(), |
| rcu_torture_writer_state, |
| cookie, cur_ops->get_gp_state()); |
| rcutorture_one_extend(&readstate, 0, trsp, rtrsp); |
| WARN_ON_ONCE(readstate); |
| // This next splat is expected behavior if leakpointer, especially |
| // for CONFIG_RCU_STRICT_GRACE_PERIOD=y kernels. |
| WARN_ON_ONCE(leakpointer && READ_ONCE(p->rtort_pipe_count) > 1); |
| |
| /* If error or close call, record the sequence of reader protections. */ |
| if ((pipe_count > 1 || completed > 1) && !xchg(&err_segs_recorded, 1)) { |
| i = 0; |
| for (rtrsp1 = &rtseg[0]; rtrsp1 < rtrsp; rtrsp1++) |
| err_segs[i++] = *rtrsp1; |
| rt_read_nsegs = i; |
| } |
| |
| return true; |
| } |
| |
| static DEFINE_TORTURE_RANDOM_PERCPU(rcu_torture_timer_rand); |
| |
| /* |
| * RCU torture reader from timer handler. Dereferences rcu_torture_current, |
| * incrementing the corresponding element of the pipeline array. The |
| * counter in the element should never be greater than 1, otherwise, the |
| * RCU implementation is broken. |
| */ |
| static void rcu_torture_timer(struct timer_list *unused) |
| { |
| atomic_long_inc(&n_rcu_torture_timers); |
| (void)rcu_torture_one_read(this_cpu_ptr(&rcu_torture_timer_rand), -1); |
| |
| /* Test call_rcu() invocation from interrupt handler. */ |
| if (cur_ops->call) { |
| struct rcu_head *rhp = kmalloc(sizeof(*rhp), GFP_NOWAIT); |
| |
| if (rhp) |
| cur_ops->call(rhp, rcu_torture_timer_cb); |
| } |
| } |
| |
| /* |
| * RCU torture reader kthread. Repeatedly dereferences rcu_torture_current, |
| * incrementing the corresponding element of the pipeline array. The |
| * counter in the element should never be greater than 1, otherwise, the |
| * RCU implementation is broken. |
| */ |
| static int |
| rcu_torture_reader(void *arg) |
| { |
| unsigned long lastsleep = jiffies; |
| long myid = (long)arg; |
| int mynumonline = myid; |
| DEFINE_TORTURE_RANDOM(rand); |
| struct timer_list t; |
| |
| VERBOSE_TOROUT_STRING("rcu_torture_reader task started"); |
| set_user_nice(current, MAX_NICE); |
| if (irqreader && cur_ops->irq_capable) |
| timer_setup_on_stack(&t, rcu_torture_timer, 0); |
| tick_dep_set_task(current, TICK_DEP_BIT_RCU); |
| do { |
| if (irqreader && cur_ops->irq_capable) { |
| if (!timer_pending(&t)) |
| mod_timer(&t, jiffies + 1); |
| } |
| if (!rcu_torture_one_read(&rand, myid) && !torture_must_stop()) |
| schedule_timeout_interruptible(HZ); |
| if (time_after(jiffies, lastsleep) && !torture_must_stop()) { |
| torture_hrtimeout_us(500, 1000, &rand); |
| lastsleep = jiffies + 10; |
| } |
| while (torture_num_online_cpus() < mynumonline && !torture_must_stop()) |
| schedule_timeout_interruptible(HZ / 5); |
| stutter_wait("rcu_torture_reader"); |
| } while (!torture_must_stop()); |
| if (irqreader && cur_ops->irq_capable) { |
| del_timer_sync(&t); |
| destroy_timer_on_stack(&t); |
| } |
| tick_dep_clear_task(current, TICK_DEP_BIT_RCU); |
| torture_kthread_stopping("rcu_torture_reader"); |
| return 0; |
| } |
| |
| /* |
| * Randomly Toggle CPUs' callback-offload state. This uses hrtimers to |
| * increase race probabilities and fuzzes the interval between toggling. |
| */ |
| static int rcu_nocb_toggle(void *arg) |
| { |
| int cpu; |
| int maxcpu = -1; |
| int oldnice = task_nice(current); |
| long r; |
| DEFINE_TORTURE_RANDOM(rand); |
| ktime_t toggle_delay; |
| unsigned long toggle_fuzz; |
| ktime_t toggle_interval = ms_to_ktime(nocbs_toggle); |
| |
| VERBOSE_TOROUT_STRING("rcu_nocb_toggle task started"); |
| while (!rcu_inkernel_boot_has_ended()) |
| schedule_timeout_interruptible(HZ / 10); |
| for_each_online_cpu(cpu) |
| maxcpu = cpu; |
| WARN_ON(maxcpu < 0); |
| if (toggle_interval > ULONG_MAX) |
| toggle_fuzz = ULONG_MAX >> 3; |
| else |
| toggle_fuzz = toggle_interval >> 3; |
| if (toggle_fuzz <= 0) |
| toggle_fuzz = NSEC_PER_USEC; |
| do { |
| r = torture_random(&rand); |
| cpu = (r >> 4) % (maxcpu + 1); |
| if (r & 0x1) { |
| rcu_nocb_cpu_offload(cpu); |
| atomic_long_inc(&n_nocb_offload); |
| } else { |
| rcu_nocb_cpu_deoffload(cpu); |
| atomic_long_inc(&n_nocb_deoffload); |
| } |
| toggle_delay = torture_random(&rand) % toggle_fuzz + toggle_interval; |
| set_current_state(TASK_INTERRUPTIBLE); |
| schedule_hrtimeout(&toggle_delay, HRTIMER_MODE_REL); |
| if (stutter_wait("rcu_nocb_toggle")) |
| sched_set_normal(current, oldnice); |
| } while (!torture_must_stop()); |
| torture_kthread_stopping("rcu_nocb_toggle"); |
| return 0; |
| } |
| |
| /* |
| * Print torture statistics. Caller must ensure that there is only |
| * one call to this function at a given time!!! This is normally |
| * accomplished by relying on the module system to only have one copy |
| * of the module loaded, and then by giving the rcu_torture_stats |
| * kthread full control (or the init/cleanup functions when rcu_torture_stats |
| * thread is not running). |
| */ |
| static void |
| rcu_torture_stats_print(void) |
| { |
| int cpu; |
| int i; |
| long pipesummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 }; |
| long batchsummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 }; |
| struct rcu_torture *rtcp; |
| static unsigned long rtcv_snap = ULONG_MAX; |
| static bool splatted; |
| struct task_struct *wtp; |
| |
| for_each_possible_cpu(cpu) { |
| for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) { |
| pipesummary[i] += READ_ONCE(per_cpu(rcu_torture_count, cpu)[i]); |
| batchsummary[i] += READ_ONCE(per_cpu(rcu_torture_batch, cpu)[i]); |
| } |
| } |
| for (i = RCU_TORTURE_PIPE_LEN; i >= 0; i--) { |
| if (pipesummary[i] != 0) |
| break; |
| } |
| |
| pr_alert("%s%s ", torture_type, TORTURE_FLAG); |
| rtcp = rcu_access_pointer(rcu_torture_current); |
| pr_cont("rtc: %p %s: %lu tfle: %d rta: %d rtaf: %d rtf: %d ", |
| rtcp, |
| rtcp && !rcu_stall_is_suppressed_at_boot() ? "ver" : "VER", |
| rcu_torture_current_version, |
| list_empty(&rcu_torture_freelist), |
| atomic_read(&n_rcu_torture_alloc), |
| atomic_read(&n_rcu_torture_alloc_fail), |
| atomic_read(&n_rcu_torture_free)); |
| pr_cont("rtmbe: %d rtmbkf: %d/%d rtbe: %ld rtbke: %ld rtbre: %ld ", |
| atomic_read(&n_rcu_torture_mberror), |
| atomic_read(&n_rcu_torture_mbchk_fail), atomic_read(&n_rcu_torture_mbchk_tries), |
| n_rcu_torture_barrier_error, |
| n_rcu_torture_boost_ktrerror, |
| n_rcu_torture_boost_rterror); |
| pr_cont("rtbf: %ld rtb: %ld nt: %ld ", |
| n_rcu_torture_boost_failure, |
| n_rcu_torture_boosts, |
| atomic_long_read(&n_rcu_torture_timers)); |
| torture_onoff_stats(); |
| pr_cont("barrier: %ld/%ld:%ld ", |
| data_race(n_barrier_successes), |
| data_race(n_barrier_attempts), |
| data_race(n_rcu_torture_barrier_error)); |
| pr_cont("read-exits: %ld ", data_race(n_read_exits)); // Statistic. |
| pr_cont("nocb-toggles: %ld:%ld\n", |
| atomic_long_read(&n_nocb_offload), atomic_long_read(&n_nocb_deoffload)); |
| |
| pr_alert("%s%s ", torture_type, TORTURE_FLAG); |
| if (atomic_read(&n_rcu_torture_mberror) || |
| atomic_read(&n_rcu_torture_mbchk_fail) || |
| n_rcu_torture_barrier_error || n_rcu_torture_boost_ktrerror || |
| n_rcu_torture_boost_rterror || n_rcu_torture_boost_failure || |
| i > 1) { |
| pr_cont("%s", "!!! "); |
| atomic_inc(&n_rcu_torture_error); |
| WARN_ON_ONCE(atomic_read(&n_rcu_torture_mberror)); |
| WARN_ON_ONCE(atomic_read(&n_rcu_torture_mbchk_fail)); |
| WARN_ON_ONCE(n_rcu_torture_barrier_error); // rcu_barrier() |
| WARN_ON_ONCE(n_rcu_torture_boost_ktrerror); // no boost kthread |
| WARN_ON_ONCE(n_rcu_torture_boost_rterror); // can't set RT prio |
| WARN_ON_ONCE(n_rcu_torture_boost_failure); // boost failed (TIMER_SOFTIRQ RT prio?) |
| WARN_ON_ONCE(i > 1); // Too-short grace period |
| } |
| pr_cont("Reader Pipe: "); |
| for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) |
| pr_cont(" %ld", pipesummary[i]); |
| pr_cont("\n"); |
| |
| pr_alert("%s%s ", torture_type, TORTURE_FLAG); |
| pr_cont("Reader Batch: "); |
| for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) |
| pr_cont(" %ld", batchsummary[i]); |
| pr_cont("\n"); |
| |
| pr_alert("%s%s ", torture_type, TORTURE_FLAG); |
| pr_cont("Free-Block Circulation: "); |
| for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) { |
| pr_cont(" %d", atomic_read(&rcu_torture_wcount[i])); |
| } |
| pr_cont("\n"); |
| |
| if (cur_ops->stats) |
| cur_ops->stats(); |
| if (rtcv_snap == rcu_torture_current_version && |
| rcu_access_pointer(rcu_torture_current) && |
| !rcu_stall_is_suppressed()) { |
| int __maybe_unused flags = 0; |
| unsigned long __maybe_unused gp_seq = 0; |
| |
| rcutorture_get_gp_data(cur_ops->ttype, |
| &flags, &gp_seq); |
| srcutorture_get_gp_data(cur_ops->ttype, srcu_ctlp, |
| &flags, &gp_seq); |
| wtp = READ_ONCE(writer_task); |
| pr_alert("??? Writer stall state %s(%d) g%lu f%#x ->state %#x cpu %d\n", |
| rcu_torture_writer_state_getname(), |
| rcu_torture_writer_state, gp_seq, flags, |
| wtp == NULL ? ~0U : wtp->__state, |
| wtp == NULL ? -1 : (int)task_cpu(wtp)); |
| if (!splatted && wtp) { |
| sched_show_task(wtp); |
| splatted = true; |
| } |
| if (cur_ops->gp_kthread_dbg) |
| cur_ops->gp_kthread_dbg(); |
| rcu_ftrace_dump(DUMP_ALL); |
| } |
| rtcv_snap = rcu_torture_current_version; |
| } |
| |
| /* |
| * Periodically prints torture statistics, if periodic statistics printing |
| * was specified via the stat_interval module parameter. |
| */ |
| static int |
| rcu_torture_stats(void *arg) |
| { |
| VERBOSE_TOROUT_STRING("rcu_torture_stats task started"); |
| do { |
| schedule_timeout_interruptible(stat_interval * HZ); |
| rcu_torture_stats_print(); |
| torture_shutdown_absorb("rcu_torture_stats"); |
| } while (!torture_must_stop()); |
| torture_kthread_stopping("rcu_torture_stats"); |
| return 0; |
| } |
| |
| /* Test mem_dump_obj() and friends. */ |
| static void rcu_torture_mem_dump_obj(void) |
| { |
| struct rcu_head *rhp; |
| struct kmem_cache *kcp; |
| static int z; |
| |
| kcp = kmem_cache_create("rcuscale", 136, 8, SLAB_STORE_USER, NULL); |
| if (WARN_ON_ONCE(!kcp)) |
| return; |
| rhp = kmem_cache_alloc(kcp, GFP_KERNEL); |
| if (WARN_ON_ONCE(!rhp)) { |
| kmem_cache_destroy(kcp); |
| return; |
| } |
| pr_alert("mem_dump_obj() slab test: rcu_torture_stats = %px, &rhp = %px, rhp = %px, &z = %px\n", stats_task, &rhp, rhp, &z); |
| pr_alert("mem_dump_obj(ZERO_SIZE_PTR):"); |
| mem_dump_obj(ZERO_SIZE_PTR); |
| pr_alert("mem_dump_obj(NULL):"); |
| mem_dump_obj(NULL); |
| pr_alert("mem_dump_obj(%px):", &rhp); |
| mem_dump_obj(&rhp); |
| pr_alert("mem_dump_obj(%px):", rhp); |
| mem_dump_obj(rhp); |
| pr_alert("mem_dump_obj(%px):", &rhp->func); |
| mem_dump_obj(&rhp->func); |
| pr_alert("mem_dump_obj(%px):", &z); |
| mem_dump_obj(&z); |
| kmem_cache_free(kcp, rhp); |
| kmem_cache_destroy(kcp); |
| rhp = kmalloc(sizeof(*rhp), GFP_KERNEL); |
| if (WARN_ON_ONCE(!rhp)) |
| return; |
| pr_alert("mem_dump_obj() kmalloc test: rcu_torture_stats = %px, &rhp = %px, rhp = %px\n", stats_task, &rhp, rhp); |
| pr_alert("mem_dump_obj(kmalloc %px):", rhp); |
| mem_dump_obj(rhp); |
| pr_alert("mem_dump_obj(kmalloc %px):", &rhp->func); |
| mem_dump_obj(&rhp->func); |
| kfree(rhp); |
| rhp = vmalloc(4096); |
| if (WARN_ON_ONCE(!rhp)) |
| return; |
| pr_alert("mem_dump_obj() vmalloc test: rcu_torture_stats = %px, &rhp = %px, rhp = %px\n", stats_task, &rhp, rhp); |
| pr_alert("mem_dump_obj(vmalloc %px):", rhp); |
| mem_dump_obj(rhp); |
| pr_alert("mem_dump_obj(vmalloc %px):", &rhp->func); |
| mem_dump_obj(&rhp->func); |
| vfree(rhp); |
| } |
| |
| static void |
| rcu_torture_print_module_parms(struct rcu_torture_ops *cur_ops, const char *tag) |
| { |
| pr_alert("%s" TORTURE_FLAG |
| "--- %s: nreaders=%d nfakewriters=%d " |
| "stat_interval=%d verbose=%d test_no_idle_hz=%d " |
| "shuffle_interval=%d stutter=%d irqreader=%d " |
| "fqs_duration=%d fqs_holdoff=%d fqs_stutter=%d " |
| "test_boost=%d/%d test_boost_interval=%d " |
| "test_boost_duration=%d shutdown_secs=%d " |
| "stall_cpu=%d stall_cpu_holdoff=%d stall_cpu_irqsoff=%d " |
| "stall_cpu_block=%d " |
| "n_barrier_cbs=%d " |
| "onoff_interval=%d onoff_holdoff=%d " |
| "read_exit_delay=%d read_exit_burst=%d " |
| "nocbs_nthreads=%d nocbs_toggle=%d\n", |
| torture_type, tag, nrealreaders, nfakewriters, |
| stat_interval, verbose, test_no_idle_hz, shuffle_interval, |
| stutter, irqreader, fqs_duration, fqs_holdoff, fqs_stutter, |
| test_boost, cur_ops->can_boost, |
| test_boost_interval, test_boost_duration, shutdown_secs, |
| stall_cpu, stall_cpu_holdoff, stall_cpu_irqsoff, |
| stall_cpu_block, |
| n_barrier_cbs, |
| onoff_interval, onoff_holdoff, |
| read_exit_delay, read_exit_burst, |
| nocbs_nthreads, nocbs_toggle); |
| } |
| |
| static int rcutorture_booster_cleanup(unsigned int cpu) |
| { |
| struct task_struct *t; |
| |
| if (boost_tasks[cpu] == NULL) |
| return 0; |
| mutex_lock(&boost_mutex); |
| t = boost_tasks[cpu]; |
| boost_tasks[cpu] = NULL; |
| rcu_torture_enable_rt_throttle(); |
| mutex_unlock(&boost_mutex); |
| |
| /* This must be outside of the mutex, otherwise deadlock! */ |
| torture_stop_kthread(rcu_torture_boost, t); |
| return 0; |
| } |
| |
| static int rcutorture_booster_init(unsigned int cpu) |
| { |
| int retval; |
| |
| if (boost_tasks[cpu] != NULL) |
| return 0; /* Already created, nothing more to do. */ |
| |
| // Testing RCU priority boosting requires rcutorture do |
| // some serious abuse. Counter this by running ksoftirqd |
| // at higher priority. |
| if (IS_BUILTIN(CONFIG_RCU_TORTURE_TEST)) { |
| struct sched_param sp; |
| struct task_struct *t; |
| |
| t = per_cpu(ksoftirqd, cpu); |
| WARN_ON_ONCE(!t); |
| sp.sched_priority = 2; |
| sched_setscheduler_nocheck(t, SCHED_FIFO, &sp); |
| } |
| |
| /* Don't allow time recalculation while creating a new task. */ |
| mutex_lock(&boost_mutex); |
| rcu_torture_disable_rt_throttle(); |
| VERBOSE_TOROUT_STRING("Creating rcu_torture_boost task"); |
| boost_tasks[cpu] = kthread_run_on_cpu(rcu_torture_boost, NULL, |
| cpu, "rcu_torture_boost_%u"); |
| if (IS_ERR(boost_tasks[cpu])) { |
| retval = PTR_ERR(boost_tasks[cpu]); |
| VERBOSE_TOROUT_STRING("rcu_torture_boost task create failed"); |
| n_rcu_torture_boost_ktrerror++; |
| boost_tasks[cpu] = NULL; |
| mutex_unlock(&boost_mutex); |
| return retval; |
| } |
| mutex_unlock(&boost_mutex); |
| return 0; |
| } |
| |
| /* |
| * CPU-stall kthread. It waits as specified by stall_cpu_holdoff, then |
| * induces a CPU stall for the time specified by stall_cpu. |
| */ |
| static int rcu_torture_stall(void *args) |
| { |
| int idx; |
| unsigned long stop_at; |
| |
| VERBOSE_TOROUT_STRING("rcu_torture_stall task started"); |
| if (stall_cpu_holdoff > 0) { |
| VERBOSE_TOROUT_STRING("rcu_torture_stall begin holdoff"); |
| schedule_timeout_interruptible(stall_cpu_holdoff * HZ); |
| VERBOSE_TOROUT_STRING("rcu_torture_stall end holdoff"); |
| } |
| if (!kthread_should_stop() && stall_gp_kthread > 0) { |
| VERBOSE_TOROUT_STRING("rcu_torture_stall begin GP stall"); |
| rcu_gp_set_torture_wait(stall_gp_kthread * HZ); |
| for (idx = 0; idx < stall_gp_kthread + 2; idx++) { |
| if (kthread_should_stop()) |
| break; |
| schedule_timeout_uninterruptible(HZ); |
| } |
| } |
| if (!kthread_should_stop() && stall_cpu > 0) { |
| VERBOSE_TOROUT_STRING("rcu_torture_stall begin CPU stall"); |
| stop_at = ktime_get_seconds() + stall_cpu; |
| /* RCU CPU stall is expected behavior in following code. */ |
| idx = cur_ops->readlock(); |
| if (stall_cpu_irqsoff) |
| local_irq_disable(); |
| else if (!stall_cpu_block) |
| preempt_disable(); |
| pr_alert("%s start on CPU %d.\n", |
| __func__, raw_smp_processor_id()); |
| while (ULONG_CMP_LT((unsigned long)ktime_get_seconds(), |
| stop_at)) |
| if (stall_cpu_block) { |
| #ifdef CONFIG_PREEMPTION |
| preempt_schedule(); |
| #else |
| schedule_timeout_uninterruptible(HZ); |
| #endif |
| } else if (stall_no_softlockup) { |
| touch_softlockup_watchdog(); |
| } |
| if (stall_cpu_irqsoff) |
| local_irq_enable(); |
| else if (!stall_cpu_block) |
| preempt_enable(); |
| cur_ops->readunlock(idx); |
| } |
| pr_alert("%s end.\n", __func__); |
| torture_shutdown_absorb("rcu_torture_stall"); |
| while (!kthread_should_stop()) |
| schedule_timeout_interruptible(10 * HZ); |
| return 0; |
| } |
| |
| /* Spawn CPU-stall kthread, if stall_cpu specified. */ |
| static int __init rcu_torture_stall_init(void) |
| { |
| if (stall_cpu <= 0 && stall_gp_kthread <= 0) |
| return 0; |
| return torture_create_kthread(rcu_torture_stall, NULL, stall_task); |
| } |
| |
| /* State structure for forward-progress self-propagating RCU callback. */ |
| struct fwd_cb_state { |
| struct rcu_head rh; |
| int stop; |
| }; |
| |
| /* |
| * Forward-progress self-propagating RCU callback function. Because |
| * callbacks run from softirq, this function is an implicit RCU read-side |
| * critical section. |
| */ |
| static void rcu_torture_fwd_prog_cb(struct rcu_head *rhp) |
| { |
| struct fwd_cb_state *fcsp = container_of(rhp, struct fwd_cb_state, rh); |
| |
| if (READ_ONCE(fcsp->stop)) { |
| WRITE_ONCE(fcsp->stop, 2); |
| return; |
| } |
| cur_ops->call(&fcsp->rh, rcu_torture_fwd_prog_cb); |
| } |
| |
| /* State for continuous-flood RCU callbacks. */ |
| struct rcu_fwd_cb { |
| struct rcu_head rh; |
| struct rcu_fwd_cb *rfc_next; |
| struct rcu_fwd *rfc_rfp; |
| int rfc_gps; |
| }; |
| |
| #define MAX_FWD_CB_JIFFIES (8 * HZ) /* Maximum CB test duration. */ |
| #define MIN_FWD_CB_LAUNDERS 3 /* This many CB invocations to count. */ |
| #define MIN_FWD_CBS_LAUNDERED 100 /* Number of counted CBs. */ |
| #define FWD_CBS_HIST_DIV 10 /* Histogram buckets/second. */ |
| #define N_LAUNDERS_HIST (2 * MAX_FWD_CB_JIFFIES / (HZ / FWD_CBS_HIST_DIV)) |
| |
| struct rcu_launder_hist { |
| long n_launders; |
| unsigned long launder_gp_seq; |
| }; |
| |
| struct rcu_fwd { |
| spinlock_t rcu_fwd_lock; |
| struct rcu_fwd_cb *rcu_fwd_cb_head; |
| struct rcu_fwd_cb **rcu_fwd_cb_tail; |
| long n_launders_cb; |
| unsigned long rcu_fwd_startat; |
| struct rcu_launder_hist n_launders_hist[N_LAUNDERS_HIST]; |
| unsigned long rcu_launder_gp_seq_start; |
| int rcu_fwd_id; |
| }; |
| |
| static DEFINE_MUTEX(rcu_fwd_mutex); |
| static struct rcu_fwd *rcu_fwds; |
| static unsigned long rcu_fwd_seq; |
| static atomic_long_t rcu_fwd_max_cbs; |
| static bool rcu_fwd_emergency_stop; |
| |
| static void rcu_torture_fwd_cb_hist(struct rcu_fwd *rfp) |
| { |
| unsigned long gps; |
| unsigned long gps_old; |
| int i; |
| int j; |
| |
| for (i = ARRAY_SIZE(rfp->n_launders_hist) - 1; i > 0; i--) |
| if (rfp->n_launders_hist[i].n_launders > 0) |
| break; |
| pr_alert("%s: Callback-invocation histogram %d (duration %lu jiffies):", |
| __func__, rfp->rcu_fwd_id, jiffies - rfp->rcu_fwd_startat); |
| gps_old = rfp->rcu_launder_gp_seq_start; |
| for (j = 0; j <= i; j++) { |
| gps = rfp->n_launders_hist[j].launder_gp_seq; |
| pr_cont(" %ds/%d: %ld:%ld", |
| j + 1, FWD_CBS_HIST_DIV, |
| rfp->n_launders_hist[j].n_launders, |
| rcutorture_seq_diff(gps, gps_old)); |
| gps_old = gps; |
| } |
| pr_cont("\n"); |
| } |
| |
| /* Callback function for continuous-flood RCU callbacks. */ |
| static void rcu_torture_fwd_cb_cr(struct rcu_head *rhp) |
| { |
| unsigned long flags; |
| int i; |
| struct rcu_fwd_cb *rfcp = container_of(rhp, struct rcu_fwd_cb, rh); |
| struct rcu_fwd_cb **rfcpp; |
| struct rcu_fwd *rfp = rfcp->rfc_rfp; |
| |
| rfcp->rfc_next = NULL; |
| rfcp->rfc_gps++; |
| spin_lock_irqsave(&rfp->rcu_fwd_lock, flags); |
| rfcpp = rfp->rcu_fwd_cb_tail; |
| rfp->rcu_fwd_cb_tail = &rfcp->rfc_next; |
| WRITE_ONCE(*rfcpp, rfcp); |
| WRITE_ONCE(rfp->n_launders_cb, rfp->n_launders_cb + 1); |
| i = ((jiffies - rfp->rcu_fwd_startat) / (HZ / FWD_CBS_HIST_DIV)); |
| if (i >= ARRAY_SIZE(rfp->n_launders_hist)) |
| i = ARRAY_SIZE(rfp->n_launders_hist) - 1; |
| rfp->n_launders_hist[i].n_launders++; |
| rfp->n_launders_hist[i].launder_gp_seq = cur_ops->get_gp_seq(); |
| spin_unlock_irqrestore(&rfp->rcu_fwd_lock, flags); |
| } |
| |
| // Give the scheduler a chance, even on nohz_full CPUs. |
| static void rcu_torture_fwd_prog_cond_resched(unsigned long iter) |
| { |
| if (IS_ENABLED(CONFIG_PREEMPTION) && IS_ENABLED(CONFIG_NO_HZ_FULL)) { |
| // Real call_rcu() floods hit userspace, so emulate that. |
| if (need_resched() || (iter & 0xfff)) |
| schedule(); |
| return; |
| } |
| // No userspace emulation: CB invocation throttles call_rcu() |
| cond_resched(); |
| } |
| |
| /* |
| * Free all callbacks on the rcu_fwd_cb_head list, either because the |
| * test is over or because we hit an OOM event. |
| */ |
| static unsigned long rcu_torture_fwd_prog_cbfree(struct rcu_fwd *rfp) |
| { |
| unsigned long flags; |
| unsigned long freed = 0; |
| struct rcu_fwd_cb *rfcp; |
| |
| for (;;) { |
| spin_lock_irqsave(&rfp->rcu_fwd_lock, flags); |
| rfcp = rfp->rcu_fwd_cb_head; |
| if (!rfcp) { |
| spin_unlock_irqrestore(&rfp->rcu_fwd_lock, flags); |
| break; |
| } |
| rfp->rcu_fwd_cb_head = rfcp->rfc_next; |
| if (!rfp->rcu_fwd_cb_head) |
| rfp->rcu_fwd_cb_tail = &rfp->rcu_fwd_cb_head; |
| spin_unlock_irqrestore(&rfp->rcu_fwd_lock, flags); |
| kfree(rfcp); |
| freed++; |
| rcu_torture_fwd_prog_cond_resched(freed); |
| if (tick_nohz_full_enabled()) { |
| local_irq_save(flags); |
| rcu_momentary_dyntick_idle(); |
| local_irq_restore(flags); |
| } |
| } |
| return freed; |
| } |
| |
| /* Carry out need_resched()/cond_resched() forward-progress testing. */ |
| static void rcu_torture_fwd_prog_nr(struct rcu_fwd *rfp, |
| int *tested, int *tested_tries) |
| { |
| unsigned long cver; |
| unsigned long dur; |
| struct fwd_cb_state fcs; |
| unsigned long gps; |
| int idx; |
| int sd; |
| int sd4; |
| bool selfpropcb = false; |
| unsigned long stopat; |
| static DEFINE_TORTURE_RANDOM(trs); |
| |
| pr_alert("%s: Starting forward-progress test %d\n", __func__, rfp->rcu_fwd_id); |
| 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; |
| } |
| |
| /* Tight loop containing cond_resched(). */ |
| atomic_inc(&rcu_fwd_cb_nodelay); |
| cur_ops->sync(); /* Later readers see above write. */ |
| if (selfpropcb) { |
| WRITE_ONCE(fcs.stop, 0); |
| cur_ops->call(&fcs.rh, rcu_torture_fwd_prog_cb); |
| } |
| cver = READ_ONCE(rcu_torture_current_version); |
| gps = cur_ops->get_gp_seq(); |
| sd = cur_ops->stall_dur() + 1; |
| sd4 = (sd + fwd_progress_div - 1) / fwd_progress_div; |
| dur = sd4 + torture_random(&trs) % (sd - sd4); |
| WRITE_ONCE(rfp->rcu_fwd_startat, jiffies); |
| stopat = rfp->rcu_fwd_startat + dur; |
| while (time_before(jiffies, stopat) && |
| !shutdown_time_arrived() && |
| !READ_ONCE(rcu_fwd_emergency_stop) && !torture_must_stop()) { |
| idx = cur_ops->readlock(); |
| udelay(10); |
| cur_ops->readunlock(idx); |
| if (!fwd_progress_need_resched || need_resched()) |
| cond_resched(); |
| } |
| (*tested_tries)++; |
| if (!time_before(jiffies, stopat) && |
| !shutdown_time_arrived() && |
| !READ_ONCE(rcu_fwd_emergency_stop) && !torture_must_stop()) { |
| (*tested)++; |
| cver = READ_ONCE(rcu_torture_current_version) - cver; |
| gps = rcutorture_seq_diff(cur_ops->get_gp_seq(), gps); |
| WARN_ON(!cver && gps < 2); |
| pr_alert("%s: %d Duration %ld cver %ld gps %ld\n", __func__, |
| rfp->rcu_fwd_id, dur, cver, gps); |
| } |
| if (selfpropcb) { |
| WRITE_ONCE(fcs.stop, 1); |
| cur_ops->sync(); /* Wait for running CB to complete. */ |
| pr_alert("%s: Waiting for CBs: %pS() %d\n", __func__, cur_ops->cb_barrier, rfp->rcu_fwd_id); |
| cur_ops->cb_barrier(); /* Wait for queued callbacks. */ |
| } |
| |
| if (selfpropcb) { |
| WARN_ON(READ_ONCE(fcs.stop) != 2); |
| destroy_rcu_head_on_stack(&fcs.rh); |
| } |
| schedule_timeout_uninterruptible(HZ / 10); /* Let kthreads recover. */ |
| atomic_dec(&rcu_fwd_cb_nodelay); |
| } |
| |
| /* Carry out call_rcu() forward-progress testing. */ |
| static void rcu_torture_fwd_prog_cr(struct rcu_fwd *rfp) |
| { |
| unsigned long cver; |
| unsigned long flags; |
| unsigned long gps; |
| int i; |
| long n_launders; |
| long n_launders_cb_snap; |
| long n_launders_sa; |
| long n_max_cbs; |
| long n_max_gps; |
| struct rcu_fwd_cb *rfcp; |
| struct rcu_fwd_cb *rfcpn; |
| unsigned long stopat; |
| unsigned long stoppedat; |
| |
| pr_alert("%s: Starting forward-progress test %d\n", __func__, rfp->rcu_fwd_id); |
| if (READ_ONCE(rcu_fwd_emergency_stop)) |
| return; /* Get out of the way quickly, no GP wait! */ |
| if (!cur_ops->call) |
| return; /* Can't do call_rcu() fwd prog without ->call. */ |
| |
| /* Loop continuously posting RCU callbacks. */ |
| atomic_inc(&rcu_fwd_cb_nodelay); |
| cur_ops->sync(); /* Later readers see above write. */ |
| WRITE_ONCE(rfp->rcu_fwd_startat, jiffies); |
| stopat = rfp->rcu_fwd_startat + MAX_FWD_CB_JIFFIES; |
| n_launders = 0; |
| rfp->n_launders_cb = 0; // Hoist initialization for multi-kthread |
| n_launders_sa = 0; |
| n_max_cbs = 0; |
| n_max_gps = 0; |
| for (i = 0; i < ARRAY_SIZE(rfp->n_launders_hist); i++) |
| rfp->n_launders_hist[i].n_launders = 0; |
| cver = READ_ONCE(rcu_torture_current_version); |
| gps = cur_ops->get_gp_seq(); |
| rfp->rcu_launder_gp_seq_start = gps; |
| tick_dep_set_task(current, TICK_DEP_BIT_RCU); |
| while (time_before(jiffies, stopat) && |
| !shutdown_time_arrived() && |
| !READ_ONCE(rcu_fwd_emergency_stop) && !torture_must_stop()) { |
| rfcp = READ_ONCE(rfp->rcu_fwd_cb_head); |
| rfcpn = NULL; |
| if (rfcp) |
| rfcpn = READ_ONCE(rfcp->rfc_next); |
| if (rfcpn) { |
| if (rfcp->rfc_gps >= MIN_FWD_CB_LAUNDERS && |
| ++n_max_gps >= MIN_FWD_CBS_LAUNDERED) |
| break; |
| rfp->rcu_fwd_cb_head = rfcpn; |
| n_launders++; |
| n_launders_sa++; |
| } else if (!cur_ops->cbflood_max || cur_ops->cbflood_max > n_max_cbs) { |
| rfcp = kmalloc(sizeof(*rfcp), GFP_KERNEL); |
| if (WARN_ON_ONCE(!rfcp)) { |
| schedule_timeout_interruptible(1); |
| continue; |
| } |
| n_max_cbs++; |
| n_launders_sa = 0; |
| rfcp->rfc_gps = 0; |
| rfcp->rfc_rfp = rfp; |
| } else { |
| rfcp = NULL; |
| } |
| if (rfcp) |
| cur_ops->call(&rfcp->rh, rcu_torture_fwd_cb_cr); |
| rcu_torture_fwd_prog_cond_resched(n_launders + n_max_cbs); |
| if (tick_nohz_full_enabled()) { |
| local_irq_save(flags); |
| rcu_momentary_dyntick_idle(); |
| local_irq_restore(flags); |
| } |
| } |
| stoppedat = jiffies; |
| n_launders_cb_snap = READ_ONCE(rfp->n_launders_cb); |
| cver = READ_ONCE(rcu_torture_current_version) - cver; |
| gps = rcutorture_seq_diff(cur_ops->get_gp_seq(), gps); |
| pr_alert("%s: Waiting for CBs: %pS() %d\n", __func__, cur_ops->cb_barrier, rfp->rcu_fwd_id); |
| cur_ops->cb_barrier(); /* Wait for callbacks to be invoked. */ |
| (void)rcu_torture_fwd_prog_cbfree(rfp); |
| |
| if (!torture_must_stop() && !READ_ONCE(rcu_fwd_emergency_stop) && |
| !shutdown_time_arrived()) { |
| WARN_ON(n_max_gps < MIN_FWD_CBS_LAUNDERED); |
| pr_alert("%s Duration %lu barrier: %lu pending %ld n_launders: %ld n_launders_sa: %ld n_max_gps: %ld n_max_cbs: %ld cver %ld gps %ld\n", |
| __func__, |
| stoppedat - rfp->rcu_fwd_startat, jiffies - stoppedat, |
| n_launders + n_max_cbs - n_launders_cb_snap, |
| n_launders, n_launders_sa, |
| n_max_gps, n_max_cbs, cver, gps); |
| atomic_long_add(n_max_cbs, &rcu_fwd_max_cbs); |
| mutex_lock(&rcu_fwd_mutex); // Serialize histograms. |
| rcu_torture_fwd_cb_hist(rfp); |
| mutex_unlock(&rcu_fwd_mutex); |
| } |
| schedule_timeout_uninterruptible(HZ); /* Let CBs drain. */ |
| tick_dep_clear_task(current, TICK_DEP_BIT_RCU); |
| atomic_dec(&rcu_fwd_cb_nodelay); |
| } |
| |
| |
| /* |
| * OOM notifier, but this only prints diagnostic information for the |
| * current forward-progress test. |
| */ |
| static int rcutorture_oom_notify(struct notifier_block *self, |
| unsigned long notused, void *nfreed) |
| { |
| int i; |
| long ncbs; |
| struct rcu_fwd *rfp; |
| |
| mutex_lock(&rcu_fwd_mutex); |
| rfp = rcu_fwds; |
| if (!rfp) { |
| mutex_unlock(&rcu_fwd_mutex); |
| return NOTIFY_OK; |
| } |
| WARN(1, "%s invoked upon OOM during forward-progress testing.\n", |
| __func__); |
| for (i = 0; i < fwd_progress; i++) { |
| rcu_torture_fwd_cb_hist(&rfp[i]); |
| rcu_fwd_progress_check(1 + (jiffies - READ_ONCE(rfp[i].rcu_fwd_startat)) / 2); |
| } |
| WRITE_ONCE(rcu_fwd_emergency_stop, true); |
| smp_mb(); /* Emergency stop before free and wait to avoid hangs. */ |
| ncbs = 0; |
| for (i = 0; i < fwd_progress; i++) |
| ncbs += rcu_torture_fwd_prog_cbfree(&rfp[i]); |
| pr_info("%s: Freed %lu RCU callbacks.\n", __func__, ncbs); |
| rcu_barrier(); |
| ncbs = 0; |
| for (i = 0; i < fwd_progress; i++) |
| ncbs += rcu_torture_fwd_prog_cbfree(&rfp[i]); |
| pr_info("%s: Freed %lu RCU callbacks.\n", __func__, ncbs); |
| rcu_barrier(); |
| ncbs = 0; |
| for (i = 0; i < fwd_progress; i++) |
| ncbs += rcu_torture_fwd_prog_cbfree(&rfp[i]); |
| pr_info("%s: Freed %lu RCU callbacks.\n", __func__, ncbs); |
| smp_mb(); /* Frees before return to avoid redoing OOM. */ |
| (*(unsigned long *)nfreed)++; /* Forward progress CBs freed! */ |
| pr_info("%s returning after OOM processing.\n", __func__); |
| mutex_unlock(&rcu_fwd_mutex); |
| return NOTIFY_OK; |
| } |
| |
| static struct notifier_block rcutorture_oom_nb = { |
| .notifier_call = rcutorture_oom_notify |
| }; |
| |
| /* Carry out grace-period forward-progress testing. */ |
| static int rcu_torture_fwd_prog(void *args) |
| { |
| bool firsttime = true; |
| long max_cbs; |
| int oldnice = task_nice(current); |
| unsigned long oldseq = READ_ONCE(rcu_fwd_seq); |
| struct rcu_fwd *rfp = args; |
| int tested = 0; |
| int tested_tries = 0; |
| |
| VERBOSE_TOROUT_STRING("rcu_torture_fwd_progress task started"); |
| rcu_bind_current_to_nocb(); |
| if (!IS_ENABLED(CONFIG_SMP) || !IS_ENABLED(CONFIG_RCU_BOOST)) |
| set_user_nice(current, MAX_NICE); |
| do { |
| if (!rfp->rcu_fwd_id) { |
| schedule_timeout_interruptible(fwd_progress_holdoff * HZ); |
| WRITE_ONCE(rcu_fwd_emergency_stop, false); |
| if (!firsttime) { |
| max_cbs = atomic_long_xchg(&rcu_fwd_max_cbs, 0); |
| pr_alert("%s n_max_cbs: %ld\n", __func__, max_cbs); |
| } |
| firsttime = false; |
| WRITE_ONCE(rcu_fwd_seq, rcu_fwd_seq + 1); |
| } else { |
| while (READ_ONCE(rcu_fwd_seq) == oldseq && !torture_must_stop()) |
| schedule_timeout_interruptible(1); |
| oldseq = READ_ONCE(rcu_fwd_seq); |
| } |
| pr_alert("%s: Starting forward-progress test %d\n", __func__, rfp->rcu_fwd_id); |
| if (rcu_inkernel_boot_has_ended() && torture_num_online_cpus() > rfp->rcu_fwd_id) |
| rcu_torture_fwd_prog_cr(rfp); |
| if ((cur_ops->stall_dur && cur_ops->stall_dur() > 0) && |
| (!IS_ENABLED(CONFIG_TINY_RCU) || |
| (rcu_inkernel_boot_has_ended() && |
| torture_num_online_cpus() > rfp->rcu_fwd_id))) |
| rcu_torture_fwd_prog_nr(rfp, &tested, &tested_tries); |
| |
| /* Avoid slow periods, better to test when busy. */ |
| if (stutter_wait("rcu_torture_fwd_prog")) |
| sched_set_normal(current, oldnice); |
| } while (!torture_must_stop()); |
| /* Short runs might not contain a valid forward-progress attempt. */ |
| if (!rfp->rcu_fwd_id) { |
| WARN_ON(!tested && tested_tries >= 5); |
| pr_alert("%s: tested %d tested_tries %d\n", __func__, tested, tested_tries); |
| } |
| torture_kthread_stopping("rcu_torture_fwd_prog"); |
| return 0; |
| } |
| |
| /* If forward-progress checking is requested and feasible, spawn the thread. */ |
| static int __init rcu_torture_fwd_prog_init(void) |
| { |
| int i; |
| int ret = 0; |
| struct rcu_fwd *rfp; |
| |
| if (!fwd_progress) |
| return 0; /* Not requested, so don't do it. */ |
| if (fwd_progress >= nr_cpu_ids) { |
| VERBOSE_TOROUT_STRING("rcu_torture_fwd_prog_init: Limiting fwd_progress to # CPUs.\n"); |
| fwd_progress = nr_cpu_ids; |
| } else if (fwd_progress < 0) { |
| fwd_progress = nr_cpu_ids; |
| } |
| if ((!cur_ops->sync && !cur_ops->call) || |
| (!cur_ops->cbflood_max && (!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"); |
| fwd_progress = 0; |
| return 0; |
| } |
| if (stall_cpu > 0) { |
| VERBOSE_TOROUT_STRING("rcu_torture_fwd_prog_init: Disabled, conflicts with CPU-stall testing"); |
| fwd_progress = 0; |
| 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; |
| } |
| if (fwd_progress_holdoff <= 0) |
| fwd_progress_holdoff = 1; |
| if (fwd_progress_div <= 0) |
| fwd_progress_div = 4; |
| rfp = kcalloc(fwd_progress, sizeof(*rfp), GFP_KERNEL); |
| fwd_prog_tasks = kcalloc(fwd_progress, sizeof(*fwd_prog_tasks), GFP_KERNEL); |
| if (!rfp || !fwd_prog_tasks) { |
| kfree(rfp); |
| kfree(fwd_prog_tasks); |
| fwd_prog_tasks = NULL; |
| fwd_progress = 0; |
| return -ENOMEM; |
| } |
| for (i = 0; i < fwd_progress; i++) { |
| spin_lock_init(&rfp[i].rcu_fwd_lock); |
| rfp[i].rcu_fwd_cb_tail = &rfp[i].rcu_fwd_cb_head; |
| rfp[i].rcu_fwd_id = i; |
| } |
| mutex_lock(&rcu_fwd_mutex); |
| rcu_fwds = rfp; |
| mutex_unlock(&rcu_fwd_mutex); |
| register_oom_notifier(&rcutorture_oom_nb); |
| for (i = 0; i < fwd_progress; i++) { |
| ret = torture_create_kthread(rcu_torture_fwd_prog, &rcu_fwds[i], fwd_prog_tasks[i]); |
| if (ret) { |
| fwd_progress = i; |
| return ret; |
| } |
| } |
| return 0; |
| } |
| |
| static void rcu_torture_fwd_prog_cleanup(void) |
| { |
| int i; |
| struct rcu_fwd *rfp; |
| |
| if (!rcu_fwds || !fwd_prog_tasks) |
| return; |
| for (i = 0; i < fwd_progress; i++) |
| torture_stop_kthread(rcu_torture_fwd_prog, fwd_prog_tasks[i]); |
| unregister_oom_notifier(&rcutorture_oom_nb); |
| mutex_lock(&rcu_fwd_mutex); |
| rfp = rcu_fwds; |
| rcu_fwds = NULL; |
| mutex_unlock(&rcu_fwd_mutex); |
| kfree(rfp); |
| kfree(fwd_prog_tasks); |
| fwd_prog_tasks = NULL; |
| } |
| |
| /* Callback function for RCU barrier testing. */ |
| static void rcu_torture_barrier_cbf(struct rcu_head *rcu) |
| { |
| atomic_inc(&barrier_cbs_invoked); |
| } |
| |
| /* IPI handler to get callback posted on desired CPU, if online. */ |
| static void rcu_torture_barrier1cb(void *rcu_void) |
| { |
| struct rcu_head *rhp = rcu_void; |
| |
| cur_ops->call(rhp, rcu_torture_barrier_cbf); |
| } |
| |
| /* kthread function to register callbacks used to test RCU barriers. */ |
| static int rcu_torture_barrier_cbs(void *arg) |
| { |
| long myid = (long)arg; |
| bool lastphase = false; |
| bool newphase; |
| struct rcu_head rcu; |
| |
| init_rcu_head_on_stack(&rcu); |
| VERBOSE_TOROUT_STRING("rcu_torture_barrier_cbs task started"); |
| set_user_nice(current, MAX_NICE); |
| do { |
| wait_event(barrier_cbs_wq[myid], |
| (newphase = |
| smp_load_acquire(&barrier_phase)) != lastphase || |
| torture_must_stop()); |
| lastphase = newphase; |
| if (torture_must_stop()) |
| break; |
| /* |
| * The above smp_load_acquire() ensures barrier_phase load |
| * is ordered before the following ->call(). |
| */ |
| if (smp_call_function_single(myid, rcu_torture_barrier1cb, |
| &rcu, 1)) { |
| // IPI failed, so use direct call from current CPU. |
| cur_ops->call(&rcu, rcu_torture_barrier_cbf); |
| } |
| if (atomic_dec_and_test(&barrier_cbs_count)) |
| wake_up(&barrier_wq); |
| } while (!torture_must_stop()); |
| if (cur_ops->cb_barrier != NULL) |
| cur_ops->cb_barrier(); |
| destroy_rcu_head_on_stack(&rcu); |
| torture_kthread_stopping("rcu_torture_barrier_cbs"); |
| return 0; |
| } |
| |
| /* kthread function to drive and coordinate RCU barrier testing. */ |
| static int rcu_torture_barrier(void *arg) |
| { |
| int i; |
| |
| VERBOSE_TOROUT_STRING("rcu_torture_barrier task starting"); |
| do { |
| atomic_set(&barrier_cbs_invoked, 0); |
| atomic_set(&barrier_cbs_count, n_barrier_cbs); |
| /* Ensure barrier_phase ordered after prior assignments. */ |
| smp_store_release(&barrier_phase, !barrier_phase); |
| for (i = 0; i < n_barrier_cbs; i++) |
| wake_up(&barrier_cbs_wq[i]); |
| wait_event(barrier_wq, |
| atomic_read(&barrier_cbs_count) == 0 || |
| torture_must_stop()); |
| if (torture_must_stop()) |
| break; |
| n_barrier_attempts++; |
| cur_ops->cb_barrier(); /* Implies smp_mb() for wait_event(). */ |
| if (atomic_read(&barrier_cbs_invoked) != n_barrier_cbs) { |
| n_rcu_torture_barrier_error++; |
| pr_err("barrier_cbs_invoked = %d, n_barrier_cbs = %d\n", |
| atomic_read(&barrier_cbs_invoked), |
| n_barrier_cbs); |
| WARN_ON(1); |
| // Wait manually for the remaining callbacks |
| i = 0; |
| do { |
| if (WARN_ON(i++ > HZ)) |
| i = INT_MIN; |
| schedule_timeout_interruptible(1); |
| cur_ops->cb_barrier(); |
| } while (atomic_read(&barrier_cbs_invoked) != |
| n_barrier_cbs && |
| !torture_must_stop()); |
| smp_mb(); // Can't trust ordering if broken. |
| if (!torture_must_stop()) |
| pr_err("Recovered: barrier_cbs_invoked = %d\n", |
| atomic_read(&barrier_cbs_invoked)); |
| } else { |
| n_barrier_successes++; |
| } |
| schedule_timeout_interruptible(HZ / 10); |
| } while (!torture_must_stop()); |
| torture_kthread_stopping("rcu_torture_barrier"); |
| return 0; |
| } |
| |
| /* Initialize RCU barrier testing. */ |
| static int rcu_torture_barrier_init(void) |
| { |
| int i; |
| int ret; |
| |
| if (n_barrier_cbs <= 0) |
| return 0; |
| if (cur_ops->call == NULL || cur_ops->cb_barrier == NULL) { |
| pr_alert("%s" TORTURE_FLAG |
| " Call or barrier ops missing for %s,\n", |
| torture_type, cur_ops->name); |
| pr_alert("%s" TORTURE_FLAG |
| " RCU barrier testing omitted from run.\n", |
| torture_type); |
| return 0; |
| } |
| atomic_set(&barrier_cbs_count, 0); |
| atomic_set(&barrier_cbs_invoked, 0); |
| barrier_cbs_tasks = |
| kcalloc(n_barrier_cbs, sizeof(barrier_cbs_tasks[0]), |
| GFP_KERNEL); |
| barrier_cbs_wq = |
| kcalloc(n_barrier_cbs, sizeof(barrier_cbs_wq[0]), GFP_KERNEL); |
| if (barrier_cbs_tasks == NULL || !barrier_cbs_wq) |
| return -ENOMEM; |
| for (i = 0; i < n_barrier_cbs; i++) { |
| init_waitqueue_head(&barrier_cbs_wq[i]); |
| ret = torture_create_kthread(rcu_torture_barrier_cbs, |
| (void *)(long)i, |
| barrier_cbs_tasks[i]); |
| if (ret) |
| return ret; |
| } |
| return torture_create_kthread(rcu_torture_barrier, NULL, barrier_task); |
| } |
| |
| /* Clean up after RCU barrier testing. */ |
| static void rcu_torture_barrier_cleanup(void) |
| { |
| int i; |
| |
| torture_stop_kthread(rcu_torture_barrier, barrier_task); |
| if (barrier_cbs_tasks != NULL) { |
| for (i = 0; i < n_barrier_cbs; i++) |
| torture_stop_kthread(rcu_torture_barrier_cbs, |
| barrier_cbs_tasks[i]); |
| kfree(barrier_cbs_tasks); |
| barrier_cbs_tasks = NULL; |
| } |
| if (barrier_cbs_wq != NULL) { |
| kfree(barrier_cbs_wq); |
| barrier_cbs_wq = NULL; |
| } |
| } |
| |
| static bool rcu_torture_can_boost(void) |
| { |
| static int boost_warn_once; |
| int prio; |
| |
| if (!(test_boost == 1 && cur_ops->can_boost) && test_boost != 2) |
| return false; |
| if (!cur_ops->start_gp_poll || !cur_ops->poll_gp_state) |
| return false; |
| |
| prio = rcu_get_gp_kthreads_prio(); |
| if (!prio) |
| return false; |
| |
| if (prio < 2) { |
| if (boost_warn_once == 1) |
| return false; |
| |
| pr_alert("%s: WARN: RCU kthread priority too low to test boosting. Skipping RCU boost test. Try passing rcutree.kthread_prio > 1 on the kernel command line.\n", KBUILD_MODNAME); |
| boost_warn_once = 1; |
| return false; |
| } |
| |
| return true; |
| } |
| |
| static bool read_exit_child_stop; |
| static bool read_exit_child_stopped; |
| static wait_queue_head_t read_exit_wq; |
| |
| // Child kthread which just does an rcutorture reader and exits. |
| static int rcu_torture_read_exit_child(void *trsp_in) |
| { |
| struct torture_random_state *trsp = trsp_in; |
| |
| set_user_nice(current, MAX_NICE); |
| // Minimize time between reading and exiting. |
| while (!kthread_should_stop()) |
| schedule_timeout_uninterruptible(1); |
| (void)rcu_torture_one_read(trsp, -1); |
| return 0; |
| } |
| |
| // Parent kthread which creates and destroys read-exit child kthreads. |
| static int rcu_torture_read_exit(void *unused) |
| { |
| bool errexit = false; |
| int i; |
| struct task_struct *tsp; |
| DEFINE_TORTURE_RANDOM(trs); |
| |
| // Allocate and initialize. |
| set_user_nice(current, MAX_NICE); |
| VERBOSE_TOROUT_STRING("rcu_torture_read_exit: Start of test"); |
| |
| // Each pass through this loop does one read-exit episode. |
| do { |
| VERBOSE_TOROUT_STRING("rcu_torture_read_exit: Start of episode"); |
| for (i = 0; i < read_exit_burst; i++) { |
| if (READ_ONCE(read_exit_child_stop)) |
| break; |
| stutter_wait("rcu_torture_read_exit"); |
| // Spawn child. |
| tsp = kthread_run(rcu_torture_read_exit_child, |
| &trs, "%s", "rcu_torture_read_exit_child"); |
| if (IS_ERR(tsp)) { |
| TOROUT_ERRSTRING("out of memory"); |
| errexit = true; |
|