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- // 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 "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 8 /* Put SRCU index in upper bits. */
- #define RCUTORTURE_RDR_MASK ((1 << RCUTORTURE_RDR_SHIFT) - 1)
- #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 0x20 /* ... entering another RCU reader. */
- #define RCUTORTURE_RDR_NBITS 6 /* 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(bool, fwd_progress, 1, "Test grace-period forward progress");
- 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_exp, false, "Use expedited GP wait primitives");
- torture_param(bool, gp_normal, false,
- "Use normal (non-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, 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(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 nrealreaders;
- static struct task_struct *writer_task;
- static struct task_struct **fakewriter_tasks;
- static struct task_struct **reader_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_task;
- 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
- struct rcu_torture {
- struct rcu_head rtort_rcu;
- int rtort_pipe_count;
- struct list_head rtort_free;
- int rtort_mbtest;
- };
- 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 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_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 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_SYNC 6
- #define RTWS_SYNC 7
- #define RTWS_STUTTER 8
- #define RTWS_STOPPING 9
- 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_SYNC",
- "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];
- }
- #if defined(CONFIG_RCU_BOOST) && !defined(CONFIG_HOTPLUG_CPU)
- #define rcu_can_boost() 1
- #else /* #if defined(CONFIG_RCU_BOOST) && !defined(CONFIG_HOTPLUG_CPU) */
- #define rcu_can_boost() 0
- #endif /* #else #if defined(CONFIG_RCU_BOOST) && !defined(CONFIG_HOTPLUG_CPU) */
- #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 bool 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);
- 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_state)(void);
- void (*cond_sync)(unsigned long oldstate);
- call_rcu_func_t call;
- void (*cb_barrier)(void);
- void (*fqs)(void);
- void (*stats)(void);
- int (*stall_dur)(void);
- int irq_capable;
- int can_boost;
- int extendables;
- int slow_gps;
- const char *name;
- };
- static struct rcu_torture_ops *cur_ops;
- /*
- * Definitions for rcu torture testing.
- */
- 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 (!READ_ONCE(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;
- 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,
- .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_state = get_state_synchronize_rcu,
- .cond_sync = cond_synchronize_rcu,
- .call = call_rcu,
- .cb_barrier = rcu_barrier,
- .fqs = rcu_force_quiescent_state,
- .stats = NULL,
- .stall_dur = rcu_jiffies_till_stall_check,
- .irq_capable = 1,
- .can_boost = rcu_can_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,
- .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 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 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,
- .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,
- .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,
- .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,
- .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,
- .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,
- .extendables = RCUTORTURE_MAX_EXTEND,
- .name = "busted_srcud"
- };
- /*
- * 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,
- .fqs = NULL,
- .stats = NULL,
- .irq_capable = 1,
- .slow_gps = 1,
- .name = "tasks"
- };
- /*
- * 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,
- .get_gp_seq = rcu_no_completed,
- .sync = synchronize_rcu_trivial,
- .exp_sync = synchronize_rcu_trivial,
- .fqs = NULL,
- .stats = NULL,
- .irq_capable = 1,
- .name = "trivial"
- };
- /*
- * 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,
- .fqs = NULL,
- .stats = NULL,
- .irq_capable = 1,
- .name = "tasks-rude"
- };
- /*
- * 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,
- .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,
- .fqs = NULL,
- .stats = NULL,
- .irq_capable = 1,
- .slow_gps = 1,
- .name = "tasks-tracing"
- };
- 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);
- }
- static bool __maybe_unused torturing_tasks(void)
- {
- return cur_ops == &tasks_ops || cur_ops == &tasks_rude_ops;
- }
- /*
- * RCU torture priority-boost testing. Runs one real-time thread per
- * CPU for moderate bursts, repeatedly registering RCU callbacks and
- * spinning waiting for them to be invoked. If a given callback takes
- * too long to be invoked, we assume that priority inversion has occurred.
- */
- struct rcu_boost_inflight {
- struct rcu_head rcu;
- int inflight;
- };
- static void rcu_torture_boost_cb(struct rcu_head *head)
- {
- struct rcu_boost_inflight *rbip =
- container_of(head, struct rcu_boost_inflight, rcu);
- /* Ensure RCU-core accesses precede clearing ->inflight */
- smp_store_release(&rbip->inflight, 0);
- }
- 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 start, unsigned long end)
- {
- if (end - start > test_boost_duration * HZ - HZ / 2) {
- VERBOSE_TOROUT_STRING("rcu_torture_boost boosting failed");
- n_rcu_torture_boost_failure++;
- return true; /* failed */
- }
- return false; /* passed */
- }
- static int rcu_torture_boost(void *arg)
- {
- unsigned long call_rcu_time;
- unsigned long endtime;
- unsigned long oldstarttime;
- struct rcu_boost_inflight rbi = { .inflight = 0 };
- VERBOSE_TOROUT_STRING("rcu_torture_boost started");
- /* Set real-time priority. */
- sched_set_fifo_low(current);
- init_rcu_head_on_stack(&rbi.rcu);
- /* Each pass through the following loop does one boost-test cycle. */
- do {
- /* Track if the test failed already in this test interval? */
- bool failed = false;
- /* Increment n_rcu_torture_boosts once per boost-test */
- while (!kthread_should_stop()) {
- if (mutex_trylock(&boost_mutex)) {
- n_rcu_torture_boosts++;
- mutex_unlock(&boost_mutex);
- break;
- }
- schedule_timeout_uninterruptible(1);
- }
- if (kthread_should_stop())
- goto checkwait;
- /* Wait for the next test interval. */
- oldstarttime = boost_starttime;
- while (time_before(jiffies, oldstarttime)) {
- schedule_timeout_interruptible(oldstarttime - jiffies);
- stutter_wait("rcu_torture_boost");
- if (torture_must_stop())
- goto checkwait;
- }
- /* Do one boost-test interval. */
- endtime = oldstarttime + test_boost_duration * HZ;
- call_rcu_time = jiffies;
- while (time_before(jiffies, endtime)) {
- /* If we don't have a callback in flight, post one. */
- if (!smp_load_acquire(&rbi.inflight)) {
- /* RCU core before ->inflight = 1. */
- smp_store_release(&rbi.inflight, 1);
- call_rcu(&rbi.rcu, rcu_torture_boost_cb);
- /* Check if the boost test failed */
- failed = failed ||
- rcu_torture_boost_failed(call_rcu_time,
- jiffies);
- call_rcu_time = jiffies;
- }
- stutter_wait("rcu_torture_boost");
- if (torture_must_stop())
- goto checkwait;
- }
- /*
- * If boost never happened, then inflight will always be 1, in
- * this case the boost check would never happen in the above
- * loop so do another one here.
- */
- if (!failed && smp_load_acquire(&rbi.inflight))
- rcu_torture_boost_failed(call_rcu_time, jiffies);
- /*
- * 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 == boost_starttime &&
- !kthread_should_stop()) {
- if (mutex_trylock(&boost_mutex)) {
- boost_starttime = jiffies +
- test_boost_interval * HZ;
- mutex_unlock(&boost_mutex);
- break;
- }
- schedule_timeout_uninterruptible(1);
- }
- /* Go do the stutter. */
- checkwait: stutter_wait("rcu_torture_boost");
- } while (!torture_must_stop());
- /* Clean up and exit. */
- while (!kthread_should_stop() || smp_load_acquire(&rbi.inflight)) {
- torture_shutdown_absorb("rcu_torture_boost");
- schedule_timeout_uninterruptible(1);
- }
- destroy_rcu_head_on_stack(&rbi.rcu);
- 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;
- 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;
- }
- stutter_wait("rcu_torture_fqs");
- } while (!torture_must_stop());
- torture_kthread_stopping("rcu_torture_fqs");
- return 0;
- }
- /*
- * 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 can_expedite = !rcu_gp_is_expedited() && !rcu_gp_is_normal();
- int expediting = 0;
- unsigned long gp_snap;
- bool gp_cond1 = gp_cond, gp_exp1 = gp_exp, gp_normal1 = gp_normal;
- bool gp_sync1 = gp_sync;
- int i;
- struct rcu_torture *rp;
- struct rcu_torture *old_rp;
- static DEFINE_TORTURE_RANDOM(rand);
- int synctype[] = { RTWS_DEF_FREE, RTWS_EXP_SYNC,
- RTWS_COND_GET, RTWS_SYNC };
- int nsynctypes = 0;
- 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);
- /* Initialize synctype[] array. If none set, take default. */
- if (!gp_cond1 && !gp_exp1 && !gp_normal1 && !gp_sync1)
- gp_cond1 = gp_exp1 = gp_normal1 = gp_sync1 = true;
- if (gp_cond1 && cur_ops->get_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_state || !cur_ops->cond_sync)) {
- pr_alert("%s: gp_cond 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_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__);
- }
- if (WARN_ONCE(nsynctypes == 0,
- "rcu_torture_writer: No update-side primitives.\n")) {
- /*
- * 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");
- }
- do {
- rcu_torture_writer_state = RTWS_FIXED_DELAY;
- schedule_timeout_uninterruptible(1);
- 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);
- 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;
- cur_ops->exp_sync();
- rcu_torture_pipe_update(old_rp);
- break;
- case RTWS_COND_GET:
- rcu_torture_writer_state = RTWS_COND_GET;
- gp_snap = cur_ops->get_state();
- i = torture_random(&rand) % 16;
- if (i != 0)
- schedule_timeout_interruptible(i);
- udelay(torture_random(&rand) % 1000);
- rcu_torture_writer_state = RTWS_COND_SYNC;
- cur_ops->cond_sync(gp_snap);
- rcu_torture_pipe_update(old_rp);
- break;
- case RTWS_SYNC:
- rcu_torture_writer_state = RTWS_SYNC;
- cur_ops->sync();
- 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;
- if (stutter_wait("rcu_torture_writer") &&
- !READ_ONCE(rcu_fwd_cb_nodelay) &&
- !cur_ops->slow_gps &&
- !torture_must_stop() &&
- rcu_inkernel_boot_has_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]) {
- rcu_ftrace_dump(DUMP_ALL);
- WARN(1, "%s: rtort_pipe_count: %d\n", __func__, rcu_tortures[i].rtort_pipe_count);
- }
- } 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)
- {
- DEFINE_TORTURE_RANDOM(rand);
- VERBOSE_TOROUT_STRING("rcu_torture_fakewriter task started");
- set_user_nice(current, MAX_NICE);
- do {
- schedule_timeout_uninterruptible(1 + torture_random(&rand)%10);
- udelay(torture_random(&rand) & 0x3ff);
- if (cur_ops->cb_barrier != NULL &&
- torture_random(&rand) % (nfakewriters * 8) == 0) {
- cur_ops->cb_barrier();
- } else if (gp_normal == gp_exp) {
- if (cur_ops->sync && torture_random(&rand) & 0x80)
- cur_ops->sync();
- else if (cur_ops->exp_sync)
- cur_ops->exp_sync();
- } else if (gp_normal && cur_ops->sync) {
- cur_ops->sync();
- } else if (cur_ops->exp_sync) {
- cur_ops->exp_sync();
- }
- 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);
- }
- /*
- * 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 idxnew = -1;
- int idxold = *readstate;
- int statesnew = ~*readstate & newstate;
- int statesold = *readstate & ~newstate;
- WARN_ON_ONCE(idxold < 0);
- WARN_ON_ONCE((idxold >> RCUTORTURE_RDR_SHIFT) > 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)
- idxnew = cur_ops->readlock() << RCUTORTURE_RDR_SHIFT;
- /*
- * 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) {
- bool lockit = !statesnew && !(torture_random(trsp) & 0xffff);
- if (lockit)
- raw_spin_lock_irqsave(¤t->pi_lock, flags);
- cur_ops->readunlock(idxold >> RCUTORTURE_RDR_SHIFT);
- 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 (idxnew == -1)
- idxnew = idxold & ~RCUTORTURE_RDR_MASK;
- WARN_ON_ONCE(idxnew < 0);
- WARN_ON_ONCE((idxnew >> RCUTORTURE_RDR_SHIFT) > 1);
- *readstate = idxnew | newstate;
- WARN_ON_ONCE((*readstate >> RCUTORTURE_RDR_SHIFT) < 0);
- WARN_ON_ONCE((*readstate >> RCUTORTURE_RDR_SHIFT) > 1);
- }
- /* 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;
- 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);
- /* 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 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;
- }
- /*
- * 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)
- {
- 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++);
- started = cur_ops->get_gp_seq();
- ts = rcu_trace_clock_local();
- p = rcu_dereference_check(rcu_torture_current,
- rcu_read_lock_bh_held() ||
- rcu_read_lock_sched_held() ||
- srcu_read_lock_held(srcu_ctlp) ||
- rcu_read_lock_trace_held() ||
- torturing_tasks());
- 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);
- 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();
- rcutorture_one_extend(&readstate, 0, trsp, rtrsp);
- WARN_ON_ONCE(readstate & RCUTORTURE_RDR_MASK);
- // 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));
- /* 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) && !torture_must_stop())
- schedule_timeout_interruptible(HZ);
- if (time_after(jiffies, lastsleep) && !torture_must_stop()) {
- schedule_timeout_interruptible(1);
- lastsleep = jiffies + 10;
- }
- while (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;
- }
- /*
- * 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 - 1; 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 rtbe: %ld rtbke: %ld rtbre: %ld ",
- atomic_read(&n_rcu_torture_mberror),
- 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\n", data_race(n_read_exits));
- pr_alert("%s%s ", torture_type, TORTURE_FLAG);
- if (atomic_read(&n_rcu_torture_mberror) ||
- 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(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); // RCU boost failed
- 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 %#lx cpu %d\n",
- rcu_torture_writer_state_getname(),
- rcu_torture_writer_state, gp_seq, flags,
- wtp == NULL ? ~0UL : wtp->state,
- wtp == NULL ? -1 : (int)task_cpu(wtp));
- if (!splatted && wtp) {
- sched_show_task(wtp);
- splatted = true;
- }
- show_rcu_gp_kthreads();
- 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;
- }
- 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\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);
- }
- 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. */
- /* 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_create_on_node(rcu_torture_boost, NULL,
- cpu_to_node(cpu),
- "rcu_torture_boost");
- 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;
- }
- kthread_bind(boost_tasks[cpu], cpu);
- wake_up_process(boost_tasks[cpu]);
- 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("rcu_torture_stall start on CPU %d.\n",
- raw_smp_processor_id());
- while (ULONG_CMP_LT((unsigned long)ktime_get_seconds(),
- stop_at))
- if (stall_cpu_block)
- schedule_timeout_uninterruptible(HZ);
- if (stall_cpu_irqsoff)
- local_irq_enable();
- else if (!stall_cpu_block)
- preempt_enable();
- cur_ops->readunlock(idx);
- }
- pr_alert("rcu_torture_stall end.\n");
- 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;
- };
- static DEFINE_MUTEX(rcu_fwd_mutex);
- static struct rcu_fwd *rcu_fwds;
- 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 (duration %lu jiffies):",
- __func__, 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);
- if (cur_ops->call && cur_ops->sync && cur_ops->cb_barrier) {
- init_rcu_head_on_stack(&fcs.rh);
- selfpropcb = true;
- }
- /* Tight loop containing cond_resched(). */
- WRITE_ONCE(rcu_fwd_cb_nodelay, true);
- 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: Duration %ld cver %ld gps %ld\n", __func__, dur, cver, gps);
- }
- if (selfpropcb) {
- WRITE_ONCE(fcs.stop, 1);
- cur_ops->sync(); /* Wait for running CB to complete. */
- 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. */
- WRITE_ONCE(rcu_fwd_cb_nodelay, false);
- }
- /* 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;
- 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. */
- WRITE_ONCE(rcu_fwd_cb_nodelay, true);
- 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 {
- 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;
- }
- 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);
- 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);
- rcu_torture_fwd_cb_hist(rfp);
- }
- schedule_timeout_uninterruptible(HZ); /* Let CBs drain. */
- tick_dep_clear_task(current, TICK_DEP_BIT_RCU);
- WRITE_ONCE(rcu_fwd_cb_nodelay, false);
- }
- /*
- * 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)
- {
- 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__);
- rcu_torture_fwd_cb_hist(rfp);
- rcu_fwd_progress_check(1 + (jiffies - READ_ONCE(rfp->rcu_fwd_startat)) / 2);
- WRITE_ONCE(rcu_fwd_emergency_stop, true);
- smp_mb(); /* Emergency stop before free and wait to avoid hangs. */
- pr_info("%s: Freed %lu RCU callbacks.\n",
- __func__, rcu_torture_fwd_prog_cbfree(rfp));
- rcu_barrier();
- pr_info("%s: Freed %lu RCU callbacks.\n",
- __func__, rcu_torture_fwd_prog_cbfree(rfp));
- rcu_barrier();
- pr_info("%s: Freed %lu RCU callbacks.\n",
- __func__, rcu_torture_fwd_prog_cbfree(rfp));
- 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)
- {
- 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 {
- schedule_timeout_interruptible(fwd_progress_holdoff * HZ);
- WRITE_ONCE(rcu_fwd_emergency_stop, false);
- if (!IS_ENABLED(CONFIG_TINY_RCU) ||
- rcu_inkernel_boot_has_ended())
- rcu_torture_fwd_prog_nr(rfp, &tested, &tested_tries);
- if (rcu_inkernel_boot_has_ended())
- rcu_torture_fwd_prog_cr(rfp);
- /* Avoid slow periods, better to test when busy. */
- stutter_wait("rcu_torture_fwd_prog");
- } while (!torture_must_stop());
- /* Short runs might not contain a valid forward-progress attempt. */
- 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)
- {
- struct rcu_fwd *rfp;
- if (!fwd_progress)
- return 0; /* Not requested, so don't do it. */
- if (!cur_ops->stall_dur || cur_ops->stall_dur() <= 0 ||
- cur_ops == &rcu_busted_ops) {
- VERBOSE_TOROUT_STRING("rcu_torture_fwd_prog_init: Disabled, unsupported by RCU flavor under test");
- return 0;
- }
- if (stall_cpu > 0) {
- VERBOSE_TOROUT_STRING("rcu_torture_fwd_prog_init: Disabled, conflicts with CPU-stall testing");
- if (IS_MODULE(CONFIG_RCU_TORTURE_TESTS))
- 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 = kzalloc(sizeof(*rfp), GFP_KERNEL);
- if (!rfp)
- return -ENOMEM;
- spin_lock_init(&rfp->rcu_fwd_lock);
- rfp->rcu_fwd_cb_tail = &rfp->rcu_fwd_cb_head;
- mutex_lock(&rcu_fwd_mutex);
- rcu_fwds = rfp;
- mutex_unlock(&rcu_fwd_mutex);
- register_oom_notifier(&rcutorture_oom_nb);
- return torture_create_kthread(rcu_torture_fwd_prog, rfp, fwd_prog_task);
- }
- static void rcu_torture_fwd_prog_cleanup(void)
- {
- struct rcu_fwd *rfp;
- torture_stop_kthread(rcu_torture_fwd_prog, fwd_prog_task);
- rfp = rcu_fwds;
- mutex_lock(&rcu_fwd_mutex);
- rcu_fwds = NULL;
- mutex_unlock(&rcu_fwd_mutex);
- unregister_oom_notifier(&rcutorture_oom_nb);
- kfree(rfp);
- }
- /* 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;
- 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);
- return 0;
- }
- // Parent kthread which creates and destroys read-exit child kthreads.
- static int rcu_torture_read_exit(void *unused)
- {
- int count = 0;
- 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 {
- if (++count > read_exit_burst) {
- VERBOSE_TOROUT_STRING("rcu_torture_read_exit: End of episode");
- rcu_barrier(); // Wait for task_struct free, avoid OOM.
- for (i = 0; i < read_exit_delay; i++) {
- schedule_timeout_uninterruptible(HZ);
- if (READ_ONCE(read_exit_child_stop))
- break;
- }
- if (!READ_ONCE(read_exit_child_stop))
- VERBOSE_TOROUT_STRING("rcu_torture_read_exit: Start of episode");
- count = 0;
- }
- if (READ_ONCE(read_exit_child_stop))
- break;
- // Spawn child.
- tsp = kthread_run(rcu_torture_read_exit_child,
- &trs, "%s",
- "rcu_torture_read_exit_child");
- if (IS_ERR(tsp)) {
- VERBOSE_TOROUT_ERRSTRING("out of memory");
- errexit = true;
- tsp = NULL;
- break;
- }
- cond_resched();
- kthread_stop(tsp);
- n_read_exits ++;
- stutter_wait("rcu_torture_read_exit");
- } while (!errexit && !READ_ONCE(read_exit_child_stop));
- // Clean up and exit.
- smp_store_release(&read_exit_child_stopped, true); // After reaping.
- smp_mb(); // Store before wakeup.
- wake_up(&read_exit_wq);
- while (!torture_must_stop())
- schedule_timeout_uninterruptible(1);
- torture_kthread_stopping("rcu_torture_read_exit");
- return 0;
- }
- static int rcu_torture_read_exit_init(void)
- {
- if (read_exit_burst <= 0)
- return -EINVAL;
- init_waitqueue_head(&read_exit_wq);
- read_exit_child_stop = false;
- read_exit_child_stopped = false;
- return torture_create_kthread(rcu_torture_read_exit, NULL,
- read_exit_task);
- }
- static void rcu_torture_read_exit_cleanup(void)
- {
- if (!read_exit_task)
- return;
- WRITE_ONCE(read_exit_child_stop, true);
- smp_mb(); // Above write before wait.
- wait_event(read_exit_wq, smp_load_acquire(&read_exit_child_stopped));
- torture_stop_kthread(rcutorture_read_exit, read_exit_task);
- }
- static enum cpuhp_state rcutor_hp;
- static void
- rcu_torture_cleanup(void)
- {
- int firsttime;
- int flags = 0;
- unsigned long gp_seq = 0;
- int i;
- if (torture_cleanup_begin()) {
- if (cur_ops->cb_barrier != NULL)
- cur_ops->cb_barrier();
- return;
- }
- if (!cur_ops) {
- torture_cleanup_end();
- return;
- }
- show_rcu_gp_kthreads();
- rcu_torture_read_exit_cleanup();
- rcu_torture_barrier_cleanup();
- rcu_torture_fwd_prog_cleanup();
- torture_stop_kthread(rcu_torture_stall, stall_task);
- torture_stop_kthread(rcu_torture_writer, writer_task);
- if (reader_tasks) {
- for (i = 0; i < nrealreaders; i++)
- torture_stop_kthread(rcu_torture_reader,
- reader_tasks[i]);
- kfree(reader_tasks);
- }
- if (fakewriter_tasks) {
- for (i = 0; i < nfakewriters; i++) {
- torture_stop_kthread(rcu_torture_fakewriter,
- fakewriter_tasks[i]);
- }
- kfree(fakewriter_tasks);
- fakewriter_tasks = NULL;
- }
- rcutorture_get_gp_data(cur_ops->ttype, &flags, &gp_seq);
- srcutorture_get_gp_data(cur_ops->ttype, srcu_ctlp, &flags, &gp_seq);
- pr_alert("%s: End-test grace-period state: g%ld f%#x total-gps=%ld\n",
- cur_ops->name, (long)gp_seq, flags,
- rcutorture_seq_diff(gp_seq, start_gp_seq));
- torture_stop_kthread(rcu_torture_stats, stats_task);
- torture_stop_kthread(rcu_torture_fqs, fqs_task);
- if (rcu_torture_can_boost())
- cpuhp_remove_state(rcutor_hp);
- /*
- * Wait for all RCU callbacks to fire, then do torture-type-specific
- * cleanup operations.
- */
- if (cur_ops->cb_barrier != NULL)
- cur_ops->cb_barrier();
- if (cur_ops->cleanup != NULL)
- cur_ops->cleanup();
- rcu_torture_stats_print(); /* -After- the stats thread is stopped! */
- if (err_segs_recorded) {
- pr_alert("Failure/close-call rcutorture reader segments:\n");
- if (rt_read_nsegs == 0)
- pr_alert("\t: No segments recorded!!!\n");
- firsttime = 1;
- for (i = 0; i < rt_read_nsegs; i++) {
- pr_alert("\t%d: %#x ", i, err_segs[i].rt_readstate);
- if (err_segs[i].rt_delay_jiffies != 0) {
- pr_cont("%s%ldjiffies", firsttime ? "" : "+",
- err_segs[i].rt_delay_jiffies);
- firsttime = 0;
- }
- if (err_segs[i].rt_delay_ms != 0) {
- pr_cont("%s%ldms", firsttime ? "" : "+",
- err_segs[i].rt_delay_ms);
- firsttime = 0;
- }
- if (err_segs[i].rt_delay_us != 0) {
- pr_cont("%s%ldus", firsttime ? "" : "+",
- err_segs[i].rt_delay_us);
- firsttime = 0;
- }
- pr_cont("%s\n",
- err_segs[i].rt_preempted ? "preempted" : "");
- }
- }
- if (atomic_read(&n_rcu_torture_error) || n_rcu_torture_barrier_error)
- rcu_torture_print_module_parms(cur_ops, "End of test: FAILURE");
- else if (torture_onoff_failures())
- rcu_torture_print_module_parms(cur_ops,
- "End of test: RCU_HOTPLUG");
- else
- rcu_torture_print_module_parms(cur_ops, "End of test: SUCCESS");
- torture_cleanup_end();
- }
- #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD
- static void rcu_torture_leak_cb(struct rcu_head *rhp)
- {
- }
- static void rcu_torture_err_cb(struct rcu_head *rhp)
- {
- /*
- * This -might- happen due to race conditions, but is unlikely.
- * The scenario that leads to this happening is that the
- * first of the pair of duplicate callbacks is queued,
- * someone else starts a grace period that includes that
- * callback, then the second of the pair must wait for the
- * next grace period. Unlikely, but can happen. If it
- * does happen, the debug-objects subsystem won't have splatted.
- */
- pr_alert("%s: duplicated callback was invoked.\n", KBUILD_MODNAME);
- }
- #endif /* #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */
- /*
- * Verify that double-free causes debug-objects to complain, but only
- * if CONFIG_DEBUG_OBJECTS_RCU_HEAD=y. Otherwise, say that the test
- * cannot be carried out.
- */
- static void rcu_test_debug_objects(void)
- {
- #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD
- struct rcu_head rh1;
- struct rcu_head rh2;
- init_rcu_head_on_stack(&rh1);
- init_rcu_head_on_stack(&rh2);
- pr_alert("%s: WARN: Duplicate call_rcu() test starting.\n", KBUILD_MODNAME);
- /* Try to queue the rh2 pair of callbacks for the same grace period. */
- preempt_disable(); /* Prevent preemption from interrupting test. */
- rcu_read_lock(); /* Make it impossible to finish a grace period. */
- call_rcu(&rh1, rcu_torture_leak_cb); /* Start grace period. */
- local_irq_disable(); /* Make it harder to start a new grace period. */
- call_rcu(&rh2, rcu_torture_leak_cb);
- call_rcu(&rh2, rcu_torture_err_cb); /* Duplicate callback. */
- local_irq_enable();
- rcu_read_unlock();
- preempt_enable();
- /* Wait for them all to get done so we can safely return. */
- rcu_barrier();
- pr_alert("%s: WARN: Duplicate call_rcu() test complete.\n", KBUILD_MODNAME);
- destroy_rcu_head_on_stack(&rh1);
- destroy_rcu_head_on_stack(&rh2);
- #else /* #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */
- pr_alert("%s: !CONFIG_DEBUG_OBJECTS_RCU_HEAD, not testing duplicate call_rcu()\n", KBUILD_MODNAME);
- #endif /* #else #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */
- }
- static void rcutorture_sync(void)
- {
- static unsigned long n;
- if (cur_ops->sync && !(++n & 0xfff))
- cur_ops->sync();
- }
- static int __init
- rcu_torture_init(void)
- {
- long i;
- int cpu;
- int firsterr = 0;
- int flags = 0;
- unsigned long gp_seq = 0;
- static struct rcu_torture_ops *torture_ops[] = {
- &rcu_ops, &rcu_busted_ops, &srcu_ops, &srcud_ops,
- &busted_srcud_ops, &tasks_ops, &tasks_rude_ops,
- &tasks_tracing_ops, &trivial_ops,
- };
- if (!torture_init_begin(torture_type, verbose))
- return -EBUSY;
- /* Process args and tell the world that the torturer is on the job. */
- for (i = 0; i < ARRAY_SIZE(torture_ops); i++) {
- cur_ops = torture_ops[i];
- if (strcmp(torture_type, cur_ops->name) == 0)
- break;
- }
- if (i == ARRAY_SIZE(torture_ops)) {
- pr_alert("rcu-torture: invalid torture type: \"%s\"\n",
- torture_type);
- pr_alert("rcu-torture types:");
- for (i = 0; i < ARRAY_SIZE(torture_ops); i++)
- pr_cont(" %s", torture_ops[i]->name);
- pr_cont("\n");
- WARN_ON(!IS_MODULE(CONFIG_RCU_TORTURE_TEST));
- firsterr = -EINVAL;
- cur_ops = NULL;
- goto unwind;
- }
- if (cur_ops->fqs == NULL && fqs_duration != 0) {
- pr_alert("rcu-torture: ->fqs NULL and non-zero fqs_duration, fqs disabled.\n");
- fqs_duration = 0;
- }
- if (cur_ops->init)
- cur_ops->init();
- if (nreaders >= 0) {
- nrealreaders = nreaders;
- } else {
- nrealreaders = num_online_cpus() - 2 - nreaders;
- if (nrealreaders <= 0)
- nrealreaders = 1;
- }
- rcu_torture_print_module_parms(cur_ops, "Start of test");
- rcutorture_get_gp_data(cur_ops->ttype, &flags, &gp_seq);
- srcutorture_get_gp_data(cur_ops->ttype, srcu_ctlp, &flags, &gp_seq);
- start_gp_seq = gp_seq;
- pr_alert("%s: Start-test grace-period state: g%ld f%#x\n",
- cur_ops->name, (long)gp_seq, flags);
- /* Set up the freelist. */
- INIT_LIST_HEAD(&rcu_torture_freelist);
- for (i = 0; i < ARRAY_SIZE(rcu_tortures); i++) {
- rcu_tortures[i].rtort_mbtest = 0;
- list_add_tail(&rcu_tortures[i].rtort_free,
- &rcu_torture_freelist);
- }
- /* Initialize the statistics so that each run gets its own numbers. */
- rcu_torture_current = NULL;
- rcu_torture_current_version = 0;
- atomic_set(&n_rcu_torture_alloc, 0);
- atomic_set(&n_rcu_torture_alloc_fail, 0);
- atomic_set(&n_rcu_torture_free, 0);
- atomic_set(&n_rcu_torture_mberror, 0);
- atomic_set(&n_rcu_torture_error, 0);
- n_rcu_torture_barrier_error = 0;
- n_rcu_torture_boost_ktrerror = 0;
- n_rcu_torture_boost_rterror = 0;
- n_rcu_torture_boost_failure = 0;
- n_rcu_torture_boosts = 0;
- for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++)
- atomic_set(&rcu_torture_wcount[i], 0);
- for_each_possible_cpu(cpu) {
- for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) {
- per_cpu(rcu_torture_count, cpu)[i] = 0;
- per_cpu(rcu_torture_batch, cpu)[i] = 0;
- }
- }
- err_segs_recorded = 0;
- rt_read_nsegs = 0;
- /* Start up the kthreads. */
- firsterr = torture_create_kthread(rcu_torture_writer, NULL,
- writer_task);
- if (firsterr)
- goto unwind;
- if (nfakewriters > 0) {
- fakewriter_tasks = kcalloc(nfakewriters,
- sizeof(fakewriter_tasks[0]),
- GFP_KERNEL);
- if (fakewriter_tasks == NULL) {
- VERBOSE_TOROUT_ERRSTRING("out of memory");
- firsterr = -ENOMEM;
- goto unwind;
- }
- }
- for (i = 0; i < nfakewriters; i++) {
- firsterr = torture_create_kthread(rcu_torture_fakewriter,
- NULL, fakewriter_tasks[i]);
- if (firsterr)
- goto unwind;
- }
- reader_tasks = kcalloc(nrealreaders, sizeof(reader_tasks[0]),
- GFP_KERNEL);
- if (reader_tasks == NULL) {
- VERBOSE_TOROUT_ERRSTRING("out of memory");
- firsterr = -ENOMEM;
- goto unwind;
- }
- for (i = 0; i < nrealreaders; i++) {
- firsterr = torture_create_kthread(rcu_torture_reader, (void *)i,
- reader_tasks[i]);
- if (firsterr)
- goto unwind;
- }
- if (stat_interval > 0) {
- firsterr = torture_create_kthread(rcu_torture_stats, NULL,
- stats_task);
- if (firsterr)
- goto unwind;
- }
- if (test_no_idle_hz && shuffle_interval > 0) {
- firsterr = torture_shuffle_init(shuffle_interval * HZ);
- if (firsterr)
- goto unwind;
- }
- if (stutter < 0)
- stutter = 0;
- if (stutter) {
- int t;
- t = cur_ops->stall_dur ? cur_ops->stall_dur() : stutter * HZ;
- firsterr = torture_stutter_init(stutter * HZ, t);
- if (firsterr)
- goto unwind;
- }
- if (fqs_duration < 0)
- fqs_duration = 0;
- if (fqs_duration) {
- /* Create the fqs thread */
- firsterr = torture_create_kthread(rcu_torture_fqs, NULL,
- fqs_task);
- if (firsterr)
- goto unwind;
- }
- if (test_boost_interval < 1)
- test_boost_interval = 1;
- if (test_boost_duration < 2)
- test_boost_duration = 2;
- if (rcu_torture_can_boost()) {
- boost_starttime = jiffies + test_boost_interval * HZ;
- firsterr = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "RCU_TORTURE",
- rcutorture_booster_init,
- rcutorture_booster_cleanup);
- if (firsterr < 0)
- goto unwind;
- rcutor_hp = firsterr;
- }
- shutdown_jiffies = jiffies + shutdown_secs * HZ;
- firsterr = torture_shutdown_init(shutdown_secs, rcu_torture_cleanup);
- if (firsterr)
- goto unwind;
- firsterr = torture_onoff_init(onoff_holdoff * HZ, onoff_interval,
- rcutorture_sync);
- if (firsterr)
- goto unwind;
- firsterr = rcu_torture_stall_init();
- if (firsterr)
- goto unwind;
- firsterr = rcu_torture_fwd_prog_init();
- if (firsterr)
- goto unwind;
- firsterr = rcu_torture_barrier_init();
- if (firsterr)
- goto unwind;
- firsterr = rcu_torture_read_exit_init();
- if (firsterr)
- goto unwind;
- if (object_debug)
- rcu_test_debug_objects();
- torture_init_end();
- return 0;
- unwind:
- torture_init_end();
- rcu_torture_cleanup();
- return firsterr;
- }
- module_init(rcu_torture_init);
- module_exit(rcu_torture_cleanup);
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