1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * Read-Copy Update module-based torture test facility 4 * 5 * Copyright (C) IBM Corporation, 2005, 2006 6 * 7 * Authors: Paul E. McKenney <paulmck@linux.ibm.com> 8 * Josh Triplett <josh@joshtriplett.org> 9 * 10 * See also: Documentation/RCU/torture.rst 11 */ 12 13 #define pr_fmt(fmt) fmt 14 15 #include <linux/types.h> 16 #include <linux/kernel.h> 17 #include <linux/init.h> 18 #include <linux/module.h> 19 #include <linux/kthread.h> 20 #include <linux/err.h> 21 #include <linux/spinlock.h> 22 #include <linux/smp.h> 23 #include <linux/rcupdate_wait.h> 24 #include <linux/rcu_notifier.h> 25 #include <linux/interrupt.h> 26 #include <linux/sched/signal.h> 27 #include <uapi/linux/sched/types.h> 28 #include <linux/atomic.h> 29 #include <linux/bitops.h> 30 #include <linux/completion.h> 31 #include <linux/moduleparam.h> 32 #include <linux/percpu.h> 33 #include <linux/notifier.h> 34 #include <linux/reboot.h> 35 #include <linux/freezer.h> 36 #include <linux/cpu.h> 37 #include <linux/delay.h> 38 #include <linux/stat.h> 39 #include <linux/srcu.h> 40 #include <linux/slab.h> 41 #include <linux/trace_clock.h> 42 #include <asm/byteorder.h> 43 #include <linux/torture.h> 44 #include <linux/vmalloc.h> 45 #include <linux/sched/debug.h> 46 #include <linux/sched/sysctl.h> 47 #include <linux/oom.h> 48 #include <linux/tick.h> 49 #include <linux/rcupdate_trace.h> 50 #include <linux/nmi.h> 51 52 #include "rcu.h" 53 54 MODULE_DESCRIPTION("Read-Copy Update module-based torture test facility"); 55 MODULE_LICENSE("GPL"); 56 MODULE_AUTHOR("Paul E. McKenney <paulmck@linux.ibm.com> and Josh Triplett <josh@joshtriplett.org>"); 57 58 // Bits for ->extendables field, extendables param, and related definitions. 59 #define RCUTORTURE_RDR_SHIFT_1 8 // Put SRCU index in upper bits. 60 #define RCUTORTURE_RDR_MASK_1 (0xff << RCUTORTURE_RDR_SHIFT_1) 61 #define RCUTORTURE_RDR_SHIFT_2 16 // Put SRCU index in upper bits. 62 #define RCUTORTURE_RDR_MASK_2 (0xff << RCUTORTURE_RDR_SHIFT_2) 63 #define RCUTORTURE_RDR_BH 0x01 // Extend readers by disabling bh. 64 #define RCUTORTURE_RDR_IRQ 0x02 // ... disabling interrupts. 65 #define RCUTORTURE_RDR_PREEMPT 0x04 // ... disabling preemption. 66 #define RCUTORTURE_RDR_RBH 0x08 // ... rcu_read_lock_bh(). 67 #define RCUTORTURE_RDR_SCHED 0x10 // ... rcu_read_lock_sched(). 68 #define RCUTORTURE_RDR_RCU_1 0x20 // ... entering another RCU reader. 69 #define RCUTORTURE_RDR_RCU_2 0x40 // ... entering another RCU reader. 70 #define RCUTORTURE_RDR_UPDOWN 0x80 // ... up-read from task, down-read from timer. 71 // Note: Manual start, automatic end. 72 #define RCUTORTURE_RDR_NBITS 8 // Number of bits defined above. 73 #define RCUTORTURE_MAX_EXTEND \ 74 (RCUTORTURE_RDR_BH | RCUTORTURE_RDR_IRQ | RCUTORTURE_RDR_PREEMPT | \ 75 RCUTORTURE_RDR_RBH | RCUTORTURE_RDR_SCHED) // Intentionally omit RCUTORTURE_RDR_UPDOWN. 76 #define RCUTORTURE_RDR_ALLBITS \ 77 (RCUTORTURE_MAX_EXTEND | RCUTORTURE_RDR_RCU_1 | RCUTORTURE_RDR_RCU_2 | \ 78 RCUTORTURE_RDR_MASK_1 | RCUTORTURE_RDR_MASK_2) 79 #define RCUTORTURE_RDR_MAX_LOOPS 0x7 /* Maximum reader extensions. */ 80 /* Must be power of two minus one. */ 81 #define RCUTORTURE_RDR_MAX_SEGS (RCUTORTURE_RDR_MAX_LOOPS + 3) 82 83 torture_param(int, extendables, RCUTORTURE_MAX_EXTEND, 84 "Extend readers by disabling bh (1), irqs (2), or preempt (4)"); 85 torture_param(int, fqs_duration, 0, "Duration of fqs bursts (us), 0 to disable"); 86 torture_param(int, fqs_holdoff, 0, "Holdoff time within fqs bursts (us)"); 87 torture_param(int, fqs_stutter, 3, "Wait time between fqs bursts (s)"); 88 torture_param(int, fwd_progress, 1, "Number of grace-period forward progress tasks (0 to disable)"); 89 torture_param(int, fwd_progress_div, 4, "Fraction of CPU stall to wait"); 90 torture_param(int, fwd_progress_holdoff, 60, "Time between forward-progress tests (s)"); 91 torture_param(bool, fwd_progress_need_resched, 1, "Hide cond_resched() behind need_resched()"); 92 torture_param(bool, gp_cond, false, "Use conditional/async GP wait primitives"); 93 torture_param(bool, gp_cond_exp, false, "Use conditional/async expedited GP wait primitives"); 94 torture_param(bool, gp_cond_full, false, "Use conditional/async full-state GP wait primitives"); 95 torture_param(bool, gp_cond_exp_full, false, 96 "Use conditional/async full-stateexpedited GP wait primitives"); 97 torture_param(int, gp_cond_wi, 16 * USEC_PER_SEC / HZ, 98 "Wait interval for normal conditional grace periods, us (default 16 jiffies)"); 99 torture_param(int, gp_cond_wi_exp, 128, 100 "Wait interval for expedited conditional grace periods, us (default 128 us)"); 101 torture_param(bool, gp_exp, false, "Use expedited GP wait primitives"); 102 torture_param(bool, gp_normal, false, "Use normal (non-expedited) GP wait primitives"); 103 torture_param(bool, gp_poll, false, "Use polling GP wait primitives"); 104 torture_param(bool, gp_poll_exp, false, "Use polling expedited GP wait primitives"); 105 torture_param(bool, gp_poll_full, false, "Use polling full-state GP wait primitives"); 106 torture_param(bool, gp_poll_exp_full, false, "Use polling full-state expedited GP wait primitives"); 107 torture_param(int, gp_poll_wi, 16 * USEC_PER_SEC / HZ, 108 "Wait interval for normal polled grace periods, us (default 16 jiffies)"); 109 torture_param(int, gp_poll_wi_exp, 128, 110 "Wait interval for expedited polled grace periods, us (default 128 us)"); 111 torture_param(bool, gp_sync, false, "Use synchronous GP wait primitives"); 112 torture_param(int, irqreader, 1, "Allow RCU readers from irq handlers"); 113 torture_param(int, leakpointer, 0, "Leak pointer dereferences from readers"); 114 torture_param(int, n_barrier_cbs, 0, "# of callbacks/kthreads for barrier testing"); 115 torture_param(int, n_up_down, 32, "# of concurrent up/down hrtimer-based RCU readers"); 116 torture_param(int, nfakewriters, 4, "Number of RCU fake writer threads"); 117 torture_param(int, nreaders, -1, "Number of RCU reader threads"); 118 torture_param(int, object_debug, 0, "Enable debug-object double call_rcu() testing"); 119 torture_param(int, onoff_holdoff, 0, "Time after boot before CPU hotplugs (s)"); 120 torture_param(int, onoff_interval, 0, "Time between CPU hotplugs (jiffies), 0=disable"); 121 torture_param(bool, gpwrap_lag, true, "Enable grace-period wrap lag testing"); 122 torture_param(int, gpwrap_lag_gps, 8, "Value to set for set_gpwrap_lag during an active testing period."); 123 torture_param(int, gpwrap_lag_cycle_mins, 30, "Total cycle duration for gpwrap lag testing (in minutes)"); 124 torture_param(int, gpwrap_lag_active_mins, 5, "Duration for which gpwrap lag is active within each cycle (in minutes)"); 125 torture_param(int, nocbs_nthreads, 0, "Number of NOCB toggle threads, 0 to disable"); 126 torture_param(int, nocbs_toggle, 1000, "Time between toggling nocb state (ms)"); 127 torture_param(int, preempt_duration, 0, "Preemption duration (ms), zero to disable"); 128 torture_param(int, preempt_interval, MSEC_PER_SEC, "Interval between preemptions (ms)"); 129 torture_param(int, read_exit_delay, 13, "Delay between read-then-exit episodes (s)"); 130 torture_param(int, read_exit_burst, 16, "# of read-then-exit bursts per episode, zero to disable"); 131 torture_param(int, reader_flavor, SRCU_READ_FLAVOR_NORMAL, "Reader flavors to use, one per bit."); 132 torture_param(int, shuffle_interval, 3, "Number of seconds between shuffles"); 133 torture_param(int, shutdown_secs, 0, "Shutdown time (s), <= zero to disable."); 134 torture_param(int, stall_cpu, 0, "Stall duration (s), zero to disable."); 135 torture_param(int, stall_cpu_holdoff, 10, "Time to wait before starting stall (s)."); 136 torture_param(bool, stall_no_softlockup, false, "Avoid softlockup warning during cpu stall."); 137 torture_param(int, stall_cpu_irqsoff, 0, "Disable interrupts while stalling."); 138 torture_param(int, stall_cpu_block, 0, "Sleep while stalling."); 139 torture_param(int, stall_cpu_repeat, 0, "Number of additional stalls after the first one."); 140 torture_param(int, stall_gp_kthread, 0, "Grace-period kthread stall duration (s)."); 141 torture_param(int, stat_interval, 60, "Number of seconds between stats printk()s"); 142 torture_param(int, stutter, 5, "Number of seconds to run/halt test"); 143 torture_param(int, test_boost, 1, "Test RCU prio boost: 0=no, 1=maybe, 2=yes."); 144 torture_param(int, test_boost_duration, 4, "Duration of each boost test, seconds."); 145 torture_param(int, test_boost_holdoff, 0, "Holdoff time from rcutorture start, seconds."); 146 torture_param(int, test_boost_interval, 7, "Interval between boost tests, seconds."); 147 torture_param(int, test_nmis, 0, "End-test NMI tests, 0 to disable."); 148 torture_param(bool, test_no_idle_hz, true, "Test support for tickless idle CPUs"); 149 torture_param(int, test_srcu_lockdep, 0, "Test specified SRCU deadlock scenario."); 150 torture_param(int, verbose, 1, "Enable verbose debugging printk()s"); 151 152 static char *torture_type = "rcu"; 153 module_param(torture_type, charp, 0444); 154 MODULE_PARM_DESC(torture_type, "Type of RCU to torture (rcu, srcu, ...)"); 155 156 static int nrealnocbers; 157 static int nrealreaders; 158 static int nrealfakewriters; 159 static struct task_struct *writer_task; 160 static struct task_struct **fakewriter_tasks; 161 static struct task_struct **reader_tasks; 162 static struct task_struct *updown_task; 163 static struct task_struct **nocb_tasks; 164 static struct task_struct *stats_task; 165 static struct task_struct *fqs_task; 166 static struct task_struct *boost_tasks[NR_CPUS]; 167 static struct task_struct *stall_task; 168 static struct task_struct **fwd_prog_tasks; 169 static struct task_struct **barrier_cbs_tasks; 170 static struct task_struct *barrier_task; 171 static struct task_struct *read_exit_task; 172 static struct task_struct *preempt_task; 173 174 #define RCU_TORTURE_PIPE_LEN 10 175 176 // Mailbox-like structure to check RCU global memory ordering. 177 struct rcu_torture_reader_check { 178 unsigned long rtc_myloops; 179 int rtc_chkrdr; 180 unsigned long rtc_chkloops; 181 int rtc_ready; 182 struct rcu_torture_reader_check *rtc_assigner; 183 } ____cacheline_internodealigned_in_smp; 184 185 // Update-side data structure used to check RCU readers. 186 struct rcu_torture { 187 struct rcu_head rtort_rcu; 188 int rtort_pipe_count; 189 struct list_head rtort_free; 190 int rtort_mbtest; 191 struct rcu_torture_reader_check *rtort_chkp; 192 }; 193 194 static LIST_HEAD(rcu_torture_freelist); 195 static struct rcu_torture __rcu *rcu_torture_current; 196 static unsigned long rcu_torture_current_version; 197 static struct rcu_torture rcu_tortures[10 * RCU_TORTURE_PIPE_LEN]; 198 static DEFINE_SPINLOCK(rcu_torture_lock); 199 static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], rcu_torture_count); 200 static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], rcu_torture_batch); 201 static atomic_t rcu_torture_wcount[RCU_TORTURE_PIPE_LEN + 1]; 202 static struct rcu_torture_reader_check *rcu_torture_reader_mbchk; 203 static atomic_t n_rcu_torture_alloc; 204 static atomic_t n_rcu_torture_alloc_fail; 205 static atomic_t n_rcu_torture_free; 206 static atomic_t n_rcu_torture_mberror; 207 static atomic_t n_rcu_torture_mbchk_fail; 208 static atomic_t n_rcu_torture_mbchk_tries; 209 static atomic_t n_rcu_torture_error; 210 static long n_rcu_torture_barrier_error; 211 static long n_rcu_torture_boost_ktrerror; 212 static long n_rcu_torture_boost_failure; 213 static long n_rcu_torture_boosts; 214 static atomic_long_t n_rcu_torture_timers; 215 static long n_barrier_attempts; 216 static long n_barrier_successes; /* did rcu_barrier test succeed? */ 217 static unsigned long n_read_exits; 218 static struct list_head rcu_torture_removed; 219 static unsigned long shutdown_jiffies; 220 static unsigned long start_gp_seq; 221 static atomic_long_t n_nocb_offload; 222 static atomic_long_t n_nocb_deoffload; 223 224 static int rcu_torture_writer_state; 225 #define RTWS_FIXED_DELAY 0 226 #define RTWS_DELAY 1 227 #define RTWS_REPLACE 2 228 #define RTWS_DEF_FREE 3 229 #define RTWS_EXP_SYNC 4 230 #define RTWS_COND_GET 5 231 #define RTWS_COND_GET_FULL 6 232 #define RTWS_COND_GET_EXP 7 233 #define RTWS_COND_GET_EXP_FULL 8 234 #define RTWS_COND_SYNC 9 235 #define RTWS_COND_SYNC_FULL 10 236 #define RTWS_COND_SYNC_EXP 11 237 #define RTWS_COND_SYNC_EXP_FULL 12 238 #define RTWS_POLL_GET 13 239 #define RTWS_POLL_GET_FULL 14 240 #define RTWS_POLL_GET_EXP 15 241 #define RTWS_POLL_GET_EXP_FULL 16 242 #define RTWS_POLL_WAIT 17 243 #define RTWS_POLL_WAIT_FULL 18 244 #define RTWS_POLL_WAIT_EXP 19 245 #define RTWS_POLL_WAIT_EXP_FULL 20 246 #define RTWS_SYNC 21 247 #define RTWS_STUTTER 22 248 #define RTWS_STOPPING 23 249 static const char * const rcu_torture_writer_state_names[] = { 250 "RTWS_FIXED_DELAY", 251 "RTWS_DELAY", 252 "RTWS_REPLACE", 253 "RTWS_DEF_FREE", 254 "RTWS_EXP_SYNC", 255 "RTWS_COND_GET", 256 "RTWS_COND_GET_FULL", 257 "RTWS_COND_GET_EXP", 258 "RTWS_COND_GET_EXP_FULL", 259 "RTWS_COND_SYNC", 260 "RTWS_COND_SYNC_FULL", 261 "RTWS_COND_SYNC_EXP", 262 "RTWS_COND_SYNC_EXP_FULL", 263 "RTWS_POLL_GET", 264 "RTWS_POLL_GET_FULL", 265 "RTWS_POLL_GET_EXP", 266 "RTWS_POLL_GET_EXP_FULL", 267 "RTWS_POLL_WAIT", 268 "RTWS_POLL_WAIT_FULL", 269 "RTWS_POLL_WAIT_EXP", 270 "RTWS_POLL_WAIT_EXP_FULL", 271 "RTWS_SYNC", 272 "RTWS_STUTTER", 273 "RTWS_STOPPING", 274 }; 275 276 /* Record reader segment types and duration for first failing read. */ 277 struct rt_read_seg { 278 int rt_readstate; 279 unsigned long rt_delay_jiffies; 280 unsigned long rt_delay_ms; 281 unsigned long rt_delay_us; 282 bool rt_preempted; 283 int rt_cpu; 284 int rt_end_cpu; 285 unsigned long long rt_gp_seq; 286 unsigned long long rt_gp_seq_end; 287 u64 rt_ts; 288 }; 289 static int err_segs_recorded; 290 static struct rt_read_seg err_segs[RCUTORTURE_RDR_MAX_SEGS]; 291 static int rt_read_nsegs; 292 static int rt_read_preempted; 293 294 static const char *rcu_torture_writer_state_getname(void) 295 { 296 unsigned int i = READ_ONCE(rcu_torture_writer_state); 297 298 if (i >= ARRAY_SIZE(rcu_torture_writer_state_names)) 299 return "???"; 300 return rcu_torture_writer_state_names[i]; 301 } 302 303 #ifdef CONFIG_RCU_TRACE 304 static u64 notrace rcu_trace_clock_local(void) 305 { 306 u64 ts = trace_clock_local(); 307 308 (void)do_div(ts, NSEC_PER_USEC); 309 return ts; 310 } 311 #else /* #ifdef CONFIG_RCU_TRACE */ 312 static u64 notrace rcu_trace_clock_local(void) 313 { 314 return 0ULL; 315 } 316 #endif /* #else #ifdef CONFIG_RCU_TRACE */ 317 318 /* 319 * Stop aggressive CPU-hog tests a bit before the end of the test in order 320 * to avoid interfering with test shutdown. 321 */ 322 static bool shutdown_time_arrived(void) 323 { 324 return shutdown_secs && time_after(jiffies, shutdown_jiffies - 30 * HZ); 325 } 326 327 static unsigned long boost_starttime; /* jiffies of next boost test start. */ 328 static DEFINE_MUTEX(boost_mutex); /* protect setting boost_starttime */ 329 /* and boost task create/destroy. */ 330 static atomic_t barrier_cbs_count; /* Barrier callbacks registered. */ 331 static bool barrier_phase; /* Test phase. */ 332 static atomic_t barrier_cbs_invoked; /* Barrier callbacks invoked. */ 333 static wait_queue_head_t *barrier_cbs_wq; /* Coordinate barrier testing. */ 334 static DECLARE_WAIT_QUEUE_HEAD(barrier_wq); 335 336 static atomic_t rcu_fwd_cb_nodelay; /* Short rcu_torture_delay() delays. */ 337 338 /* 339 * Allocate an element from the rcu_tortures pool. 340 */ 341 static struct rcu_torture * 342 rcu_torture_alloc(void) 343 { 344 struct list_head *p; 345 346 spin_lock_bh(&rcu_torture_lock); 347 if (list_empty(&rcu_torture_freelist)) { 348 atomic_inc(&n_rcu_torture_alloc_fail); 349 spin_unlock_bh(&rcu_torture_lock); 350 return NULL; 351 } 352 atomic_inc(&n_rcu_torture_alloc); 353 p = rcu_torture_freelist.next; 354 list_del_init(p); 355 spin_unlock_bh(&rcu_torture_lock); 356 return container_of(p, struct rcu_torture, rtort_free); 357 } 358 359 /* 360 * Free an element to the rcu_tortures pool. 361 */ 362 static void 363 rcu_torture_free(struct rcu_torture *p) 364 { 365 atomic_inc(&n_rcu_torture_free); 366 spin_lock_bh(&rcu_torture_lock); 367 list_add_tail(&p->rtort_free, &rcu_torture_freelist); 368 spin_unlock_bh(&rcu_torture_lock); 369 } 370 371 /* 372 * Operations vector for selecting different types of tests. 373 */ 374 375 struct rcu_torture_ops { 376 int ttype; 377 void (*init)(void); 378 void (*cleanup)(void); 379 int (*readlock)(void); 380 void (*read_delay)(struct torture_random_state *rrsp, 381 struct rt_read_seg *rtrsp); 382 void (*readunlock)(int idx); 383 int (*readlock_held)(void); // lockdep. 384 int (*readlock_nesting)(void); // actual nesting, if available, -1 if not. 385 int (*down_read)(void); 386 void (*up_read)(int idx); 387 unsigned long (*get_gp_seq)(void); 388 unsigned long (*gp_diff)(unsigned long new, unsigned long old); 389 void (*deferred_free)(struct rcu_torture *p); 390 void (*sync)(void); 391 void (*exp_sync)(void); 392 void (*exp_current)(void); 393 unsigned long (*get_gp_state_exp)(void); 394 unsigned long (*start_gp_poll_exp)(void); 395 void (*start_gp_poll_exp_full)(struct rcu_gp_oldstate *rgosp); 396 bool (*poll_gp_state_exp)(unsigned long oldstate); 397 void (*cond_sync_exp)(unsigned long oldstate); 398 void (*cond_sync_exp_full)(struct rcu_gp_oldstate *rgosp); 399 unsigned long (*get_comp_state)(void); 400 void (*get_comp_state_full)(struct rcu_gp_oldstate *rgosp); 401 bool (*same_gp_state)(unsigned long oldstate1, unsigned long oldstate2); 402 bool (*same_gp_state_full)(struct rcu_gp_oldstate *rgosp1, struct rcu_gp_oldstate *rgosp2); 403 unsigned long (*get_gp_state)(void); 404 void (*get_gp_state_full)(struct rcu_gp_oldstate *rgosp); 405 unsigned long (*start_gp_poll)(void); 406 void (*start_gp_poll_full)(struct rcu_gp_oldstate *rgosp); 407 bool (*poll_gp_state)(unsigned long oldstate); 408 bool (*poll_gp_state_full)(struct rcu_gp_oldstate *rgosp); 409 bool (*poll_need_2gp)(bool poll, bool poll_full); 410 void (*cond_sync)(unsigned long oldstate); 411 void (*cond_sync_full)(struct rcu_gp_oldstate *rgosp); 412 int poll_active; 413 int poll_active_full; 414 call_rcu_func_t call; 415 void (*cb_barrier)(void); 416 void (*fqs)(void); 417 void (*stats)(void); 418 void (*gp_kthread_dbg)(void); 419 bool (*check_boost_failed)(unsigned long gp_state, int *cpup); 420 int (*stall_dur)(void); 421 void (*get_gp_data)(int *flags, unsigned long *gp_seq); 422 void (*gp_slow_register)(atomic_t *rgssp); 423 void (*gp_slow_unregister)(atomic_t *rgssp); 424 bool (*reader_blocked)(void); 425 unsigned long long (*gather_gp_seqs)(void); 426 void (*format_gp_seqs)(unsigned long long seqs, char *cp, size_t len); 427 void (*set_gpwrap_lag)(unsigned long lag); 428 int (*get_gpwrap_count)(int cpu); 429 long cbflood_max; 430 int irq_capable; 431 int can_boost; 432 int extendables; 433 int slow_gps; 434 int no_pi_lock; 435 int debug_objects; 436 int start_poll_irqsoff; 437 int have_up_down; 438 const char *name; 439 }; 440 441 static struct rcu_torture_ops *cur_ops; 442 443 /* 444 * Definitions for rcu torture testing. 445 */ 446 447 static int torture_readlock_not_held(void) 448 { 449 return rcu_read_lock_bh_held() || rcu_read_lock_sched_held(); 450 } 451 452 static int rcu_torture_read_lock(void) 453 { 454 rcu_read_lock(); 455 return 0; 456 } 457 458 static void 459 rcu_read_delay(struct torture_random_state *rrsp, struct rt_read_seg *rtrsp) 460 { 461 unsigned long started; 462 unsigned long completed; 463 const unsigned long shortdelay_us = 200; 464 unsigned long longdelay_ms = 300; 465 unsigned long long ts; 466 467 /* We want a short delay sometimes to make a reader delay the grace 468 * period, and we want a long delay occasionally to trigger 469 * force_quiescent_state. */ 470 471 if (!atomic_read(&rcu_fwd_cb_nodelay) && 472 !(torture_random(rrsp) % (nrealreaders * 2000 * longdelay_ms))) { 473 started = cur_ops->get_gp_seq(); 474 ts = rcu_trace_clock_local(); 475 if ((preempt_count() & HARDIRQ_MASK) || softirq_count()) 476 longdelay_ms = 5; /* Avoid triggering BH limits. */ 477 mdelay(longdelay_ms); 478 rtrsp->rt_delay_ms = longdelay_ms; 479 completed = cur_ops->get_gp_seq(); 480 do_trace_rcu_torture_read(cur_ops->name, NULL, ts, 481 started, completed); 482 } 483 if (!(torture_random(rrsp) % (nrealreaders * 2 * shortdelay_us))) { 484 udelay(shortdelay_us); 485 rtrsp->rt_delay_us = shortdelay_us; 486 } 487 if (!preempt_count() && 488 !(torture_random(rrsp) % (nrealreaders * 500))) 489 torture_preempt_schedule(); /* QS only if preemptible. */ 490 } 491 492 static void rcu_torture_read_unlock(int idx) 493 { 494 rcu_read_unlock(); 495 } 496 497 static int rcu_torture_readlock_nesting(void) 498 { 499 if (IS_ENABLED(CONFIG_PREEMPT_RCU)) 500 return rcu_preempt_depth(); 501 if (IS_ENABLED(CONFIG_PREEMPT_COUNT)) 502 return (preempt_count() & PREEMPT_MASK); 503 return -1; 504 } 505 506 /* 507 * Update callback in the pipe. This should be invoked after a grace period. 508 */ 509 static bool 510 rcu_torture_pipe_update_one(struct rcu_torture *rp) 511 { 512 int i; 513 struct rcu_torture_reader_check *rtrcp = READ_ONCE(rp->rtort_chkp); 514 515 if (rtrcp) { 516 WRITE_ONCE(rp->rtort_chkp, NULL); 517 smp_store_release(&rtrcp->rtc_ready, 1); // Pair with smp_load_acquire(). 518 } 519 i = rp->rtort_pipe_count; 520 if (i > RCU_TORTURE_PIPE_LEN) 521 i = RCU_TORTURE_PIPE_LEN; 522 atomic_inc(&rcu_torture_wcount[i]); 523 WRITE_ONCE(rp->rtort_pipe_count, i + 1); 524 ASSERT_EXCLUSIVE_WRITER(rp->rtort_pipe_count); 525 if (i + 1 >= RCU_TORTURE_PIPE_LEN) { 526 rp->rtort_mbtest = 0; 527 return true; 528 } 529 return false; 530 } 531 532 /* 533 * Update all callbacks in the pipe. Suitable for synchronous grace-period 534 * primitives. 535 */ 536 static void 537 rcu_torture_pipe_update(struct rcu_torture *old_rp) 538 { 539 struct rcu_torture *rp; 540 struct rcu_torture *rp1; 541 542 if (old_rp) 543 list_add(&old_rp->rtort_free, &rcu_torture_removed); 544 list_for_each_entry_safe(rp, rp1, &rcu_torture_removed, rtort_free) { 545 if (rcu_torture_pipe_update_one(rp)) { 546 list_del(&rp->rtort_free); 547 rcu_torture_free(rp); 548 } 549 } 550 } 551 552 static void 553 rcu_torture_cb(struct rcu_head *p) 554 { 555 struct rcu_torture *rp = container_of(p, struct rcu_torture, rtort_rcu); 556 557 if (torture_must_stop_irq()) { 558 /* Test is ending, just drop callbacks on the floor. */ 559 /* The next initialization will pick up the pieces. */ 560 return; 561 } 562 if (rcu_torture_pipe_update_one(rp)) 563 rcu_torture_free(rp); 564 else 565 cur_ops->deferred_free(rp); 566 } 567 568 static unsigned long rcu_no_completed(void) 569 { 570 return 0; 571 } 572 573 static void rcu_torture_deferred_free(struct rcu_torture *p) 574 { 575 call_rcu_hurry(&p->rtort_rcu, rcu_torture_cb); 576 } 577 578 static void rcu_sync_torture_init(void) 579 { 580 INIT_LIST_HEAD(&rcu_torture_removed); 581 } 582 583 static bool rcu_poll_need_2gp(bool poll, bool poll_full) 584 { 585 return poll; 586 } 587 588 static struct rcu_torture_ops rcu_ops = { 589 .ttype = RCU_FLAVOR, 590 .init = rcu_sync_torture_init, 591 .readlock = rcu_torture_read_lock, 592 .read_delay = rcu_read_delay, 593 .readunlock = rcu_torture_read_unlock, 594 .readlock_held = torture_readlock_not_held, 595 .readlock_nesting = rcu_torture_readlock_nesting, 596 .get_gp_seq = rcu_get_gp_seq, 597 .gp_diff = rcu_seq_diff, 598 .deferred_free = rcu_torture_deferred_free, 599 .sync = synchronize_rcu, 600 .exp_sync = synchronize_rcu_expedited, 601 .same_gp_state = same_state_synchronize_rcu, 602 .same_gp_state_full = same_state_synchronize_rcu_full, 603 .get_comp_state = get_completed_synchronize_rcu, 604 .get_comp_state_full = get_completed_synchronize_rcu_full, 605 .get_gp_state = get_state_synchronize_rcu, 606 .get_gp_state_full = get_state_synchronize_rcu_full, 607 .start_gp_poll = start_poll_synchronize_rcu, 608 .start_gp_poll_full = start_poll_synchronize_rcu_full, 609 .poll_gp_state = poll_state_synchronize_rcu, 610 .poll_gp_state_full = poll_state_synchronize_rcu_full, 611 .poll_need_2gp = rcu_poll_need_2gp, 612 .cond_sync = cond_synchronize_rcu, 613 .cond_sync_full = cond_synchronize_rcu_full, 614 .poll_active = NUM_ACTIVE_RCU_POLL_OLDSTATE, 615 .poll_active_full = NUM_ACTIVE_RCU_POLL_FULL_OLDSTATE, 616 .get_gp_state_exp = get_state_synchronize_rcu, 617 .start_gp_poll_exp = start_poll_synchronize_rcu_expedited, 618 .start_gp_poll_exp_full = start_poll_synchronize_rcu_expedited_full, 619 .poll_gp_state_exp = poll_state_synchronize_rcu, 620 .cond_sync_exp = cond_synchronize_rcu_expedited, 621 .cond_sync_exp_full = cond_synchronize_rcu_expedited_full, 622 .call = call_rcu_hurry, 623 .cb_barrier = rcu_barrier, 624 .fqs = rcu_force_quiescent_state, 625 .gp_kthread_dbg = show_rcu_gp_kthreads, 626 .check_boost_failed = rcu_check_boost_fail, 627 .stall_dur = rcu_jiffies_till_stall_check, 628 .get_gp_data = rcutorture_get_gp_data, 629 .gp_slow_register = rcu_gp_slow_register, 630 .gp_slow_unregister = rcu_gp_slow_unregister, 631 .reader_blocked = IS_ENABLED(CONFIG_RCU_TORTURE_TEST_LOG_CPU) 632 ? has_rcu_reader_blocked 633 : NULL, 634 .gather_gp_seqs = rcutorture_gather_gp_seqs, 635 .format_gp_seqs = rcutorture_format_gp_seqs, 636 .set_gpwrap_lag = rcu_set_gpwrap_lag, 637 .get_gpwrap_count = rcu_get_gpwrap_count, 638 .irq_capable = 1, 639 .can_boost = IS_ENABLED(CONFIG_RCU_BOOST), 640 .extendables = RCUTORTURE_MAX_EXTEND, 641 .debug_objects = 1, 642 .start_poll_irqsoff = 1, 643 .name = "rcu" 644 }; 645 646 /* 647 * Don't even think about trying any of these in real life!!! 648 * The names includes "busted", and they really means it! 649 * The only purpose of these functions is to provide a buggy RCU 650 * implementation to make sure that rcutorture correctly emits 651 * buggy-RCU error messages. 652 */ 653 static void rcu_busted_torture_deferred_free(struct rcu_torture *p) 654 { 655 /* This is a deliberate bug for testing purposes only! */ 656 rcu_torture_cb(&p->rtort_rcu); 657 } 658 659 static void synchronize_rcu_busted(void) 660 { 661 /* This is a deliberate bug for testing purposes only! */ 662 } 663 664 static void 665 call_rcu_busted(struct rcu_head *head, rcu_callback_t func) 666 { 667 /* This is a deliberate bug for testing purposes only! */ 668 func(head); 669 } 670 671 static struct rcu_torture_ops rcu_busted_ops = { 672 .ttype = INVALID_RCU_FLAVOR, 673 .init = rcu_sync_torture_init, 674 .readlock = rcu_torture_read_lock, 675 .read_delay = rcu_read_delay, /* just reuse rcu's version. */ 676 .readunlock = rcu_torture_read_unlock, 677 .readlock_held = torture_readlock_not_held, 678 .get_gp_seq = rcu_no_completed, 679 .deferred_free = rcu_busted_torture_deferred_free, 680 .sync = synchronize_rcu_busted, 681 .exp_sync = synchronize_rcu_busted, 682 .call = call_rcu_busted, 683 .gather_gp_seqs = rcutorture_gather_gp_seqs, 684 .format_gp_seqs = rcutorture_format_gp_seqs, 685 .irq_capable = 1, 686 .extendables = RCUTORTURE_MAX_EXTEND, 687 .name = "busted" 688 }; 689 690 /* 691 * Definitions for srcu torture testing. 692 */ 693 694 DEFINE_STATIC_SRCU(srcu_ctl); 695 DEFINE_STATIC_SRCU_FAST(srcu_ctlf); 696 DEFINE_STATIC_SRCU_FAST_UPDOWN(srcu_ctlfud); 697 static struct srcu_struct srcu_ctld; 698 static struct srcu_struct *srcu_ctlp = &srcu_ctl; 699 static struct rcu_torture_ops srcud_ops; 700 701 static void srcu_torture_init(void) 702 { 703 rcu_sync_torture_init(); 704 if (!reader_flavor || (reader_flavor & SRCU_READ_FLAVOR_NORMAL)) 705 VERBOSE_TOROUT_STRING("srcu_torture_init normal SRCU"); 706 if (reader_flavor & SRCU_READ_FLAVOR_NMI) 707 VERBOSE_TOROUT_STRING("srcu_torture_init NMI-safe SRCU"); 708 if (reader_flavor & SRCU_READ_FLAVOR_FAST) { 709 srcu_ctlp = &srcu_ctlf; 710 VERBOSE_TOROUT_STRING("srcu_torture_init fast SRCU"); 711 } 712 if (reader_flavor & SRCU_READ_FLAVOR_FAST_UPDOWN) { 713 srcu_ctlp = &srcu_ctlfud; 714 VERBOSE_TOROUT_STRING("srcu_torture_init fast-up/down SRCU"); 715 } 716 } 717 718 static void srcu_get_gp_data(int *flags, unsigned long *gp_seq) 719 { 720 srcutorture_get_gp_data(srcu_ctlp, flags, gp_seq); 721 } 722 723 static int srcu_torture_read_lock(void) 724 { 725 int idx; 726 struct srcu_ctr __percpu *scp; 727 int ret = 0; 728 729 WARN_ON_ONCE(reader_flavor & ~SRCU_READ_FLAVOR_ALL); 730 731 if ((reader_flavor & SRCU_READ_FLAVOR_NORMAL) || !(reader_flavor & SRCU_READ_FLAVOR_ALL)) { 732 idx = srcu_read_lock(srcu_ctlp); 733 WARN_ON_ONCE(idx & ~0x1); 734 ret += idx; 735 } 736 if (reader_flavor & SRCU_READ_FLAVOR_NMI) { 737 idx = srcu_read_lock_nmisafe(srcu_ctlp); 738 WARN_ON_ONCE(idx & ~0x1); 739 ret += idx << 1; 740 } 741 if (reader_flavor & SRCU_READ_FLAVOR_FAST) { 742 scp = srcu_read_lock_fast(srcu_ctlp); 743 idx = __srcu_ptr_to_ctr(srcu_ctlp, scp); 744 WARN_ON_ONCE(idx & ~0x1); 745 ret += idx << 2; 746 } 747 if (reader_flavor & SRCU_READ_FLAVOR_FAST_UPDOWN) { 748 scp = srcu_read_lock_fast_updown(srcu_ctlp); 749 idx = __srcu_ptr_to_ctr(srcu_ctlp, scp); 750 WARN_ON_ONCE(idx & ~0x1); 751 ret += idx << 3; 752 } 753 return ret; 754 } 755 756 static void 757 srcu_read_delay(struct torture_random_state *rrsp, struct rt_read_seg *rtrsp) 758 { 759 long delay; 760 const long uspertick = 1000000 / HZ; 761 const long longdelay = 10; 762 763 /* We want there to be long-running readers, but not all the time. */ 764 765 delay = torture_random(rrsp) % 766 (nrealreaders * 2 * longdelay * uspertick); 767 if (!delay && in_task()) { 768 schedule_timeout_interruptible(longdelay); 769 rtrsp->rt_delay_jiffies = longdelay; 770 } else { 771 rcu_read_delay(rrsp, rtrsp); 772 } 773 } 774 775 static void srcu_torture_read_unlock(int idx) 776 { 777 WARN_ON_ONCE((reader_flavor && (idx & ~reader_flavor)) || (!reader_flavor && (idx & ~0x1))); 778 if (reader_flavor & SRCU_READ_FLAVOR_FAST_UPDOWN) 779 srcu_read_unlock_fast_updown(srcu_ctlp, 780 __srcu_ctr_to_ptr(srcu_ctlp, (idx & 0x8) >> 3)); 781 if (reader_flavor & SRCU_READ_FLAVOR_FAST) 782 srcu_read_unlock_fast(srcu_ctlp, __srcu_ctr_to_ptr(srcu_ctlp, (idx & 0x4) >> 2)); 783 if (reader_flavor & SRCU_READ_FLAVOR_NMI) 784 srcu_read_unlock_nmisafe(srcu_ctlp, (idx & 0x2) >> 1); 785 if ((reader_flavor & SRCU_READ_FLAVOR_NORMAL) || !(reader_flavor & SRCU_READ_FLAVOR_ALL)) 786 srcu_read_unlock(srcu_ctlp, idx & 0x1); 787 } 788 789 static int torture_srcu_read_lock_held(void) 790 { 791 return srcu_read_lock_held(srcu_ctlp); 792 } 793 794 static bool srcu_torture_have_up_down(void) 795 { 796 int rf = reader_flavor; 797 798 if (!rf) 799 rf = SRCU_READ_FLAVOR_NORMAL; 800 return !!(cur_ops->have_up_down & rf); 801 } 802 803 static int srcu_torture_down_read(void) 804 { 805 int idx; 806 struct srcu_ctr __percpu *scp; 807 808 WARN_ON_ONCE(reader_flavor & ~SRCU_READ_FLAVOR_ALL); 809 WARN_ON_ONCE(reader_flavor & (reader_flavor - 1)); 810 811 if ((reader_flavor & SRCU_READ_FLAVOR_NORMAL) || !(reader_flavor & SRCU_READ_FLAVOR_ALL)) { 812 idx = srcu_down_read(srcu_ctlp); 813 WARN_ON_ONCE(idx & ~0x1); 814 return idx; 815 } 816 if (reader_flavor & SRCU_READ_FLAVOR_FAST_UPDOWN) { 817 scp = srcu_down_read_fast(srcu_ctlp); 818 idx = __srcu_ptr_to_ctr(srcu_ctlp, scp); 819 WARN_ON_ONCE(idx & ~0x1); 820 return idx << 3; 821 } 822 WARN_ON_ONCE(1); 823 return 0; 824 } 825 826 static void srcu_torture_up_read(int idx) 827 { 828 WARN_ON_ONCE((reader_flavor && (idx & ~reader_flavor)) || (!reader_flavor && (idx & ~0x1))); 829 if (reader_flavor & SRCU_READ_FLAVOR_FAST_UPDOWN) 830 srcu_up_read_fast(srcu_ctlp, __srcu_ctr_to_ptr(srcu_ctlp, (idx & 0x8) >> 3)); 831 else if ((reader_flavor & SRCU_READ_FLAVOR_NORMAL) || 832 !(reader_flavor & SRCU_READ_FLAVOR_ALL)) 833 srcu_up_read(srcu_ctlp, idx & 0x1); 834 else 835 WARN_ON_ONCE(1); 836 } 837 838 static unsigned long srcu_torture_completed(void) 839 { 840 return srcu_batches_completed(srcu_ctlp); 841 } 842 843 static void srcu_torture_deferred_free(struct rcu_torture *rp) 844 { 845 call_srcu(srcu_ctlp, &rp->rtort_rcu, rcu_torture_cb); 846 } 847 848 static void srcu_torture_synchronize(void) 849 { 850 synchronize_srcu(srcu_ctlp); 851 } 852 853 static unsigned long srcu_torture_get_gp_state(void) 854 { 855 return get_state_synchronize_srcu(srcu_ctlp); 856 } 857 858 static unsigned long srcu_torture_start_gp_poll(void) 859 { 860 return start_poll_synchronize_srcu(srcu_ctlp); 861 } 862 863 static bool srcu_torture_poll_gp_state(unsigned long oldstate) 864 { 865 return poll_state_synchronize_srcu(srcu_ctlp, oldstate); 866 } 867 868 static void srcu_torture_call(struct rcu_head *head, 869 rcu_callback_t func) 870 { 871 call_srcu(srcu_ctlp, head, func); 872 } 873 874 static void srcu_torture_barrier(void) 875 { 876 srcu_barrier(srcu_ctlp); 877 } 878 879 static void srcu_torture_stats(void) 880 { 881 srcu_torture_stats_print(srcu_ctlp, torture_type, TORTURE_FLAG); 882 } 883 884 static void srcu_torture_synchronize_expedited(void) 885 { 886 synchronize_srcu_expedited(srcu_ctlp); 887 } 888 889 static void srcu_torture_expedite_current(void) 890 { 891 srcu_expedite_current(srcu_ctlp); 892 } 893 894 static struct rcu_torture_ops srcu_ops = { 895 .ttype = SRCU_FLAVOR, 896 .init = srcu_torture_init, 897 .readlock = srcu_torture_read_lock, 898 .read_delay = srcu_read_delay, 899 .readunlock = srcu_torture_read_unlock, 900 .down_read = srcu_torture_down_read, 901 .up_read = srcu_torture_up_read, 902 .readlock_held = torture_srcu_read_lock_held, 903 .get_gp_seq = srcu_torture_completed, 904 .gp_diff = rcu_seq_diff, 905 .deferred_free = srcu_torture_deferred_free, 906 .sync = srcu_torture_synchronize, 907 .exp_sync = srcu_torture_synchronize_expedited, 908 .exp_current = srcu_torture_expedite_current, 909 .same_gp_state = same_state_synchronize_srcu, 910 .get_comp_state = get_completed_synchronize_srcu, 911 .get_gp_state = srcu_torture_get_gp_state, 912 .start_gp_poll = srcu_torture_start_gp_poll, 913 .poll_gp_state = srcu_torture_poll_gp_state, 914 .poll_active = NUM_ACTIVE_SRCU_POLL_OLDSTATE, 915 .call = srcu_torture_call, 916 .cb_barrier = srcu_torture_barrier, 917 .stats = srcu_torture_stats, 918 .get_gp_data = srcu_get_gp_data, 919 .cbflood_max = 50000, 920 .irq_capable = 1, 921 .no_pi_lock = IS_ENABLED(CONFIG_TINY_SRCU), 922 .debug_objects = 1, 923 .have_up_down = IS_ENABLED(CONFIG_TINY_SRCU) 924 ? 0 : SRCU_READ_FLAVOR_NORMAL | SRCU_READ_FLAVOR_FAST_UPDOWN, 925 .name = "srcu" 926 }; 927 928 static void srcud_torture_init(void) 929 { 930 rcu_sync_torture_init(); 931 if (!reader_flavor || (reader_flavor & SRCU_READ_FLAVOR_NORMAL)) { 932 WARN_ON(init_srcu_struct(&srcu_ctld)); 933 VERBOSE_TOROUT_STRING("srcud_torture_init normal SRCU"); 934 } else if (reader_flavor & SRCU_READ_FLAVOR_NMI) { 935 WARN_ON(init_srcu_struct(&srcu_ctld)); 936 VERBOSE_TOROUT_STRING("srcud_torture_init NMI-safe SRCU"); 937 } else if (reader_flavor & SRCU_READ_FLAVOR_FAST) { 938 WARN_ON(init_srcu_struct_fast(&srcu_ctld)); 939 VERBOSE_TOROUT_STRING("srcud_torture_init fast SRCU"); 940 } else if (reader_flavor & SRCU_READ_FLAVOR_FAST_UPDOWN) { 941 WARN_ON(init_srcu_struct_fast_updown(&srcu_ctld)); 942 VERBOSE_TOROUT_STRING("srcud_torture_init fast-up/down SRCU"); 943 } else { 944 WARN_ON(init_srcu_struct(&srcu_ctld)); 945 } 946 srcu_ctlp = &srcu_ctld; 947 } 948 949 static void srcu_torture_cleanup(void) 950 { 951 cleanup_srcu_struct(&srcu_ctld); 952 srcu_ctlp = &srcu_ctl; /* In case of a later rcutorture run. */ 953 } 954 955 /* As above, but dynamically allocated. */ 956 static struct rcu_torture_ops srcud_ops = { 957 .ttype = SRCU_FLAVOR, 958 .init = srcud_torture_init, 959 .cleanup = srcu_torture_cleanup, 960 .readlock = srcu_torture_read_lock, 961 .read_delay = srcu_read_delay, 962 .readunlock = srcu_torture_read_unlock, 963 .readlock_held = torture_srcu_read_lock_held, 964 .down_read = srcu_torture_down_read, 965 .up_read = srcu_torture_up_read, 966 .get_gp_seq = srcu_torture_completed, 967 .gp_diff = rcu_seq_diff, 968 .deferred_free = srcu_torture_deferred_free, 969 .sync = srcu_torture_synchronize, 970 .exp_sync = srcu_torture_synchronize_expedited, 971 .exp_current = srcu_torture_expedite_current, 972 .same_gp_state = same_state_synchronize_srcu, 973 .get_comp_state = get_completed_synchronize_srcu, 974 .get_gp_state = srcu_torture_get_gp_state, 975 .start_gp_poll = srcu_torture_start_gp_poll, 976 .poll_gp_state = srcu_torture_poll_gp_state, 977 .poll_active = NUM_ACTIVE_SRCU_POLL_OLDSTATE, 978 .call = srcu_torture_call, 979 .cb_barrier = srcu_torture_barrier, 980 .stats = srcu_torture_stats, 981 .get_gp_data = srcu_get_gp_data, 982 .cbflood_max = 50000, 983 .irq_capable = 1, 984 .no_pi_lock = IS_ENABLED(CONFIG_TINY_SRCU), 985 .debug_objects = 1, 986 .have_up_down = IS_ENABLED(CONFIG_TINY_SRCU) 987 ? 0 : SRCU_READ_FLAVOR_NORMAL | SRCU_READ_FLAVOR_FAST_UPDOWN, 988 .name = "srcud" 989 }; 990 991 /* As above, but broken due to inappropriate reader extension. */ 992 static struct rcu_torture_ops busted_srcud_ops = { 993 .ttype = SRCU_FLAVOR, 994 .init = srcu_torture_init, 995 .cleanup = srcu_torture_cleanup, 996 .readlock = srcu_torture_read_lock, 997 .read_delay = rcu_read_delay, 998 .readunlock = srcu_torture_read_unlock, 999 .readlock_held = torture_srcu_read_lock_held, 1000 .get_gp_seq = srcu_torture_completed, 1001 .deferred_free = srcu_torture_deferred_free, 1002 .sync = srcu_torture_synchronize, 1003 .exp_sync = srcu_torture_synchronize_expedited, 1004 .call = srcu_torture_call, 1005 .cb_barrier = srcu_torture_barrier, 1006 .stats = srcu_torture_stats, 1007 .irq_capable = 1, 1008 .no_pi_lock = IS_ENABLED(CONFIG_TINY_SRCU), 1009 .extendables = RCUTORTURE_MAX_EXTEND, 1010 .name = "busted_srcud" 1011 }; 1012 1013 /* 1014 * Definitions for trivial CONFIG_PREEMPT=n-only torture testing. 1015 * This implementation does not work well with CPU hotplug nor 1016 * with rcutorture's shuffling. 1017 */ 1018 1019 static void synchronize_rcu_trivial(void) 1020 { 1021 int cpu; 1022 1023 for_each_online_cpu(cpu) { 1024 torture_sched_setaffinity(current->pid, cpumask_of(cpu), true); 1025 WARN_ON_ONCE(raw_smp_processor_id() != cpu); 1026 } 1027 } 1028 1029 static void rcu_sync_torture_init_trivial(void) 1030 { 1031 rcu_sync_torture_init(); 1032 // if (onoff_interval || shuffle_interval) { 1033 if (WARN_ONCE(onoff_interval || shuffle_interval, "%s: Non-zero onoff_interval (%d) or shuffle_interval (%d) breaks trivial RCU, resetting to zero", __func__, onoff_interval, shuffle_interval)) { 1034 onoff_interval = 0; 1035 shuffle_interval = 0; 1036 } 1037 } 1038 1039 static int rcu_torture_read_lock_trivial(void) 1040 { 1041 preempt_disable(); 1042 return 0; 1043 } 1044 1045 static void rcu_torture_read_unlock_trivial(int idx) 1046 { 1047 preempt_enable(); 1048 } 1049 1050 static struct rcu_torture_ops trivial_ops = { 1051 .ttype = RCU_TRIVIAL_FLAVOR, 1052 .init = rcu_sync_torture_init_trivial, 1053 .readlock = rcu_torture_read_lock_trivial, 1054 .read_delay = rcu_read_delay, /* just reuse rcu's version. */ 1055 .readunlock = rcu_torture_read_unlock_trivial, 1056 .readlock_held = torture_readlock_not_held, 1057 .get_gp_seq = rcu_no_completed, 1058 .sync = synchronize_rcu_trivial, 1059 .exp_sync = synchronize_rcu_trivial, 1060 .irq_capable = 1, 1061 .name = "trivial" 1062 }; 1063 1064 #ifdef CONFIG_TASKS_RCU 1065 1066 /* 1067 * Definitions for RCU-tasks torture testing. 1068 */ 1069 1070 static int tasks_torture_read_lock(void) 1071 { 1072 return 0; 1073 } 1074 1075 static void tasks_torture_read_unlock(int idx) 1076 { 1077 } 1078 1079 static void rcu_tasks_torture_deferred_free(struct rcu_torture *p) 1080 { 1081 call_rcu_tasks(&p->rtort_rcu, rcu_torture_cb); 1082 } 1083 1084 static void synchronize_rcu_mult_test(void) 1085 { 1086 synchronize_rcu_mult(call_rcu_tasks, call_rcu_hurry); 1087 } 1088 1089 static struct rcu_torture_ops tasks_ops = { 1090 .ttype = RCU_TASKS_FLAVOR, 1091 .init = rcu_sync_torture_init, 1092 .readlock = tasks_torture_read_lock, 1093 .read_delay = rcu_read_delay, /* just reuse rcu's version. */ 1094 .readunlock = tasks_torture_read_unlock, 1095 .get_gp_seq = rcu_no_completed, 1096 .deferred_free = rcu_tasks_torture_deferred_free, 1097 .sync = synchronize_rcu_tasks, 1098 .exp_sync = synchronize_rcu_mult_test, 1099 .call = call_rcu_tasks, 1100 .cb_barrier = rcu_barrier_tasks, 1101 .gp_kthread_dbg = show_rcu_tasks_classic_gp_kthread, 1102 .get_gp_data = rcu_tasks_get_gp_data, 1103 .irq_capable = 1, 1104 .slow_gps = 1, 1105 .name = "tasks" 1106 }; 1107 1108 #define TASKS_OPS &tasks_ops, 1109 1110 #else // #ifdef CONFIG_TASKS_RCU 1111 1112 #define TASKS_OPS 1113 1114 #endif // #else #ifdef CONFIG_TASKS_RCU 1115 1116 1117 #ifdef CONFIG_TASKS_RUDE_RCU 1118 1119 /* 1120 * Definitions for rude RCU-tasks torture testing. 1121 */ 1122 1123 static struct rcu_torture_ops tasks_rude_ops = { 1124 .ttype = RCU_TASKS_RUDE_FLAVOR, 1125 .init = rcu_sync_torture_init, 1126 .readlock = rcu_torture_read_lock_trivial, 1127 .read_delay = rcu_read_delay, /* just reuse rcu's version. */ 1128 .readunlock = rcu_torture_read_unlock_trivial, 1129 .get_gp_seq = rcu_no_completed, 1130 .sync = synchronize_rcu_tasks_rude, 1131 .exp_sync = synchronize_rcu_tasks_rude, 1132 .gp_kthread_dbg = show_rcu_tasks_rude_gp_kthread, 1133 .get_gp_data = rcu_tasks_rude_get_gp_data, 1134 .cbflood_max = 50000, 1135 .irq_capable = 1, 1136 .name = "tasks-rude" 1137 }; 1138 1139 #define TASKS_RUDE_OPS &tasks_rude_ops, 1140 1141 #else // #ifdef CONFIG_TASKS_RUDE_RCU 1142 1143 #define TASKS_RUDE_OPS 1144 1145 #endif // #else #ifdef CONFIG_TASKS_RUDE_RCU 1146 1147 1148 #ifdef CONFIG_TASKS_TRACE_RCU 1149 1150 /* 1151 * Definitions for tracing RCU-tasks torture testing. 1152 */ 1153 1154 static int tasks_tracing_torture_read_lock(void) 1155 { 1156 rcu_read_lock_trace(); 1157 return 0; 1158 } 1159 1160 static void tasks_tracing_torture_read_unlock(int idx) 1161 { 1162 rcu_read_unlock_trace(); 1163 } 1164 1165 static void rcu_tasks_tracing_torture_deferred_free(struct rcu_torture *p) 1166 { 1167 call_rcu_tasks_trace(&p->rtort_rcu, rcu_torture_cb); 1168 } 1169 1170 static struct rcu_torture_ops tasks_tracing_ops = { 1171 .ttype = RCU_TASKS_TRACING_FLAVOR, 1172 .init = rcu_sync_torture_init, 1173 .readlock = tasks_tracing_torture_read_lock, 1174 .read_delay = srcu_read_delay, /* just reuse srcu's version. */ 1175 .readunlock = tasks_tracing_torture_read_unlock, 1176 .readlock_held = rcu_read_lock_trace_held, 1177 .get_gp_seq = rcu_no_completed, 1178 .deferred_free = rcu_tasks_tracing_torture_deferred_free, 1179 .sync = synchronize_rcu_tasks_trace, 1180 .exp_sync = synchronize_rcu_tasks_trace, 1181 .call = call_rcu_tasks_trace, 1182 .cb_barrier = rcu_barrier_tasks_trace, 1183 .gp_kthread_dbg = show_rcu_tasks_trace_gp_kthread, 1184 .get_gp_data = rcu_tasks_trace_get_gp_data, 1185 .cbflood_max = 50000, 1186 .irq_capable = 1, 1187 .slow_gps = 1, 1188 .name = "tasks-tracing" 1189 }; 1190 1191 #define TASKS_TRACING_OPS &tasks_tracing_ops, 1192 1193 #else // #ifdef CONFIG_TASKS_TRACE_RCU 1194 1195 #define TASKS_TRACING_OPS 1196 1197 #endif // #else #ifdef CONFIG_TASKS_TRACE_RCU 1198 1199 1200 static unsigned long rcutorture_seq_diff(unsigned long new, unsigned long old) 1201 { 1202 if (!cur_ops->gp_diff) 1203 return new - old; 1204 return cur_ops->gp_diff(new, old); 1205 } 1206 1207 /* 1208 * RCU torture priority-boost testing. Runs one real-time thread per 1209 * CPU for moderate bursts, repeatedly starting grace periods and waiting 1210 * for them to complete. If a given grace period takes too long, we assume 1211 * that priority inversion has occurred. 1212 */ 1213 1214 static int old_rt_runtime = -1; 1215 1216 static void rcu_torture_disable_rt_throttle(void) 1217 { 1218 /* 1219 * Disable RT throttling so that rcutorture's boost threads don't get 1220 * throttled. Only possible if rcutorture is built-in otherwise the 1221 * user should manually do this by setting the sched_rt_period_us and 1222 * sched_rt_runtime sysctls. 1223 */ 1224 if (!IS_BUILTIN(CONFIG_RCU_TORTURE_TEST) || old_rt_runtime != -1) 1225 return; 1226 1227 old_rt_runtime = sysctl_sched_rt_runtime; 1228 sysctl_sched_rt_runtime = -1; 1229 } 1230 1231 static void rcu_torture_enable_rt_throttle(void) 1232 { 1233 if (!IS_BUILTIN(CONFIG_RCU_TORTURE_TEST) || old_rt_runtime == -1) 1234 return; 1235 1236 sysctl_sched_rt_runtime = old_rt_runtime; 1237 old_rt_runtime = -1; 1238 } 1239 1240 static bool rcu_torture_boost_failed(unsigned long gp_state, unsigned long *start) 1241 { 1242 int cpu; 1243 static int dbg_done; 1244 unsigned long end = jiffies; 1245 bool gp_done; 1246 unsigned long j; 1247 static unsigned long last_persist; 1248 unsigned long lp; 1249 unsigned long mininterval = test_boost_duration * HZ - HZ / 2; 1250 1251 if (end - *start > mininterval) { 1252 // Recheck after checking time to avoid false positives. 1253 smp_mb(); // Time check before grace-period check. 1254 if (cur_ops->poll_gp_state(gp_state)) 1255 return false; // passed, though perhaps just barely 1256 if (cur_ops->check_boost_failed && !cur_ops->check_boost_failed(gp_state, &cpu)) { 1257 // At most one persisted message per boost test. 1258 j = jiffies; 1259 lp = READ_ONCE(last_persist); 1260 if (time_after(j, lp + mininterval) && 1261 cmpxchg(&last_persist, lp, j) == lp) { 1262 if (cpu < 0) 1263 pr_info("Boost inversion persisted: QS from all CPUs\n"); 1264 else 1265 pr_info("Boost inversion persisted: No QS from CPU %d\n", cpu); 1266 } 1267 return false; // passed on a technicality 1268 } 1269 VERBOSE_TOROUT_STRING("rcu_torture_boost boosting failed"); 1270 n_rcu_torture_boost_failure++; 1271 if (!xchg(&dbg_done, 1) && cur_ops->gp_kthread_dbg) { 1272 pr_info("Boost inversion thread ->rt_priority %u gp_state %lu jiffies %lu\n", 1273 current->rt_priority, gp_state, end - *start); 1274 cur_ops->gp_kthread_dbg(); 1275 // Recheck after print to flag grace period ending during splat. 1276 gp_done = cur_ops->poll_gp_state(gp_state); 1277 pr_info("Boost inversion: GP %lu %s.\n", gp_state, 1278 gp_done ? "ended already" : "still pending"); 1279 1280 } 1281 1282 return true; // failed 1283 } else if (cur_ops->check_boost_failed && !cur_ops->check_boost_failed(gp_state, NULL)) { 1284 *start = jiffies; 1285 } 1286 1287 return false; // passed 1288 } 1289 1290 static int rcu_torture_boost(void *arg) 1291 { 1292 unsigned long endtime; 1293 unsigned long gp_state; 1294 unsigned long gp_state_time; 1295 unsigned long oldstarttime; 1296 unsigned long booststarttime = get_torture_init_jiffies() + test_boost_holdoff * HZ; 1297 1298 if (test_boost_holdoff <= 0 || time_after(jiffies, booststarttime)) { 1299 VERBOSE_TOROUT_STRING("rcu_torture_boost started"); 1300 } else { 1301 VERBOSE_TOROUT_STRING("rcu_torture_boost started holdoff period"); 1302 while (time_before(jiffies, booststarttime)) { 1303 schedule_timeout_idle(HZ); 1304 if (kthread_should_stop()) 1305 goto cleanup; 1306 } 1307 VERBOSE_TOROUT_STRING("rcu_torture_boost finished holdoff period"); 1308 } 1309 1310 /* Set real-time priority. */ 1311 sched_set_fifo_low(current); 1312 1313 /* Each pass through the following loop does one boost-test cycle. */ 1314 do { 1315 bool failed = false; // Test failed already in this test interval 1316 bool gp_initiated = false; 1317 1318 if (kthread_should_stop()) 1319 goto checkwait; 1320 1321 /* Wait for the next test interval. */ 1322 oldstarttime = READ_ONCE(boost_starttime); 1323 while (time_before(jiffies, oldstarttime)) { 1324 schedule_timeout_interruptible(oldstarttime - jiffies); 1325 if (stutter_wait("rcu_torture_boost")) 1326 sched_set_fifo_low(current); 1327 if (torture_must_stop()) 1328 goto checkwait; 1329 } 1330 1331 // Do one boost-test interval. 1332 endtime = oldstarttime + test_boost_duration * HZ; 1333 while (time_before(jiffies, endtime)) { 1334 // Has current GP gone too long? 1335 if (gp_initiated && !failed && !cur_ops->poll_gp_state(gp_state)) 1336 failed = rcu_torture_boost_failed(gp_state, &gp_state_time); 1337 // If we don't have a grace period in flight, start one. 1338 if (!gp_initiated || cur_ops->poll_gp_state(gp_state)) { 1339 gp_state = cur_ops->start_gp_poll(); 1340 gp_initiated = true; 1341 gp_state_time = jiffies; 1342 } 1343 if (stutter_wait("rcu_torture_boost")) { 1344 sched_set_fifo_low(current); 1345 // If the grace period already ended, 1346 // we don't know when that happened, so 1347 // start over. 1348 if (cur_ops->poll_gp_state(gp_state)) 1349 gp_initiated = false; 1350 } 1351 if (torture_must_stop()) 1352 goto checkwait; 1353 } 1354 1355 // In case the grace period extended beyond the end of the loop. 1356 if (gp_initiated && !failed && !cur_ops->poll_gp_state(gp_state)) 1357 rcu_torture_boost_failed(gp_state, &gp_state_time); 1358 1359 /* 1360 * Set the start time of the next test interval. 1361 * Yes, this is vulnerable to long delays, but such 1362 * delays simply cause a false negative for the next 1363 * interval. Besides, we are running at RT priority, 1364 * so delays should be relatively rare. 1365 */ 1366 while (oldstarttime == READ_ONCE(boost_starttime) && !kthread_should_stop()) { 1367 if (mutex_trylock(&boost_mutex)) { 1368 if (oldstarttime == boost_starttime) { 1369 WRITE_ONCE(boost_starttime, 1370 jiffies + test_boost_interval * HZ); 1371 n_rcu_torture_boosts++; 1372 } 1373 mutex_unlock(&boost_mutex); 1374 break; 1375 } 1376 schedule_timeout_uninterruptible(HZ / 20); 1377 } 1378 1379 /* Go do the stutter. */ 1380 checkwait: if (stutter_wait("rcu_torture_boost")) 1381 sched_set_fifo_low(current); 1382 } while (!torture_must_stop()); 1383 1384 cleanup: 1385 /* Clean up and exit. */ 1386 while (!kthread_should_stop()) { 1387 torture_shutdown_absorb("rcu_torture_boost"); 1388 schedule_timeout_uninterruptible(HZ / 20); 1389 } 1390 torture_kthread_stopping("rcu_torture_boost"); 1391 return 0; 1392 } 1393 1394 /* 1395 * RCU torture force-quiescent-state kthread. Repeatedly induces 1396 * bursts of calls to force_quiescent_state(), increasing the probability 1397 * of occurrence of some important types of race conditions. 1398 */ 1399 static int 1400 rcu_torture_fqs(void *arg) 1401 { 1402 unsigned long fqs_resume_time; 1403 int fqs_burst_remaining; 1404 int oldnice = task_nice(current); 1405 1406 VERBOSE_TOROUT_STRING("rcu_torture_fqs task started"); 1407 do { 1408 fqs_resume_time = jiffies + fqs_stutter * HZ; 1409 while (time_before(jiffies, fqs_resume_time) && 1410 !kthread_should_stop()) { 1411 schedule_timeout_interruptible(HZ / 20); 1412 } 1413 fqs_burst_remaining = fqs_duration; 1414 while (fqs_burst_remaining > 0 && 1415 !kthread_should_stop()) { 1416 cur_ops->fqs(); 1417 udelay(fqs_holdoff); 1418 fqs_burst_remaining -= fqs_holdoff; 1419 } 1420 if (stutter_wait("rcu_torture_fqs")) 1421 sched_set_normal(current, oldnice); 1422 } while (!torture_must_stop()); 1423 torture_kthread_stopping("rcu_torture_fqs"); 1424 return 0; 1425 } 1426 1427 // Used by writers to randomly choose from the available grace-period primitives. 1428 static int synctype[ARRAY_SIZE(rcu_torture_writer_state_names)] = { }; 1429 static int nsynctypes; 1430 1431 /* 1432 * Determine which grace-period primitives are available. 1433 */ 1434 static void rcu_torture_write_types(void) 1435 { 1436 bool gp_cond1 = gp_cond, gp_cond_exp1 = gp_cond_exp, gp_cond_full1 = gp_cond_full; 1437 bool gp_cond_exp_full1 = gp_cond_exp_full, gp_exp1 = gp_exp, gp_poll_exp1 = gp_poll_exp; 1438 bool gp_poll_exp_full1 = gp_poll_exp_full, gp_normal1 = gp_normal, gp_poll1 = gp_poll; 1439 bool gp_poll_full1 = gp_poll_full, gp_sync1 = gp_sync; 1440 1441 /* Initialize synctype[] array. If none set, take default. */ 1442 if (!gp_cond1 && 1443 !gp_cond_exp1 && 1444 !gp_cond_full1 && 1445 !gp_cond_exp_full1 && 1446 !gp_exp1 && 1447 !gp_poll_exp1 && 1448 !gp_poll_exp_full1 && 1449 !gp_normal1 && 1450 !gp_poll1 && 1451 !gp_poll_full1 && 1452 !gp_sync1) { 1453 gp_cond1 = true; 1454 gp_cond_exp1 = true; 1455 gp_cond_full1 = true; 1456 gp_cond_exp_full1 = true; 1457 gp_exp1 = true; 1458 gp_poll_exp1 = true; 1459 gp_poll_exp_full1 = true; 1460 gp_normal1 = true; 1461 gp_poll1 = true; 1462 gp_poll_full1 = true; 1463 gp_sync1 = true; 1464 } 1465 if (gp_cond1 && cur_ops->get_gp_state && cur_ops->cond_sync) { 1466 synctype[nsynctypes++] = RTWS_COND_GET; 1467 pr_info("%s: Testing conditional GPs.\n", __func__); 1468 } else if (gp_cond && (!cur_ops->get_gp_state || !cur_ops->cond_sync)) { 1469 pr_alert("%s: gp_cond without primitives.\n", __func__); 1470 } 1471 if (gp_cond_exp1 && cur_ops->get_gp_state_exp && cur_ops->cond_sync_exp) { 1472 synctype[nsynctypes++] = RTWS_COND_GET_EXP; 1473 pr_info("%s: Testing conditional expedited GPs.\n", __func__); 1474 } else if (gp_cond_exp && (!cur_ops->get_gp_state_exp || !cur_ops->cond_sync_exp)) { 1475 pr_alert("%s: gp_cond_exp without primitives.\n", __func__); 1476 } 1477 if (gp_cond_full1 && cur_ops->get_gp_state && cur_ops->cond_sync_full) { 1478 synctype[nsynctypes++] = RTWS_COND_GET_FULL; 1479 pr_info("%s: Testing conditional full-state GPs.\n", __func__); 1480 } else if (gp_cond_full && (!cur_ops->get_gp_state || !cur_ops->cond_sync_full)) { 1481 pr_alert("%s: gp_cond_full without primitives.\n", __func__); 1482 } 1483 if (gp_cond_exp_full1 && cur_ops->get_gp_state_exp && cur_ops->cond_sync_exp_full) { 1484 synctype[nsynctypes++] = RTWS_COND_GET_EXP_FULL; 1485 pr_info("%s: Testing conditional full-state expedited GPs.\n", __func__); 1486 } else if (gp_cond_exp_full && 1487 (!cur_ops->get_gp_state_exp || !cur_ops->cond_sync_exp_full)) { 1488 pr_alert("%s: gp_cond_exp_full without primitives.\n", __func__); 1489 } 1490 if (gp_exp1 && cur_ops->exp_sync) { 1491 synctype[nsynctypes++] = RTWS_EXP_SYNC; 1492 pr_info("%s: Testing expedited GPs.\n", __func__); 1493 } else if (gp_exp && !cur_ops->exp_sync) { 1494 pr_alert("%s: gp_exp without primitives.\n", __func__); 1495 } 1496 if (gp_normal1 && cur_ops->deferred_free) { 1497 synctype[nsynctypes++] = RTWS_DEF_FREE; 1498 pr_info("%s: Testing asynchronous GPs.\n", __func__); 1499 } else if (gp_normal && !cur_ops->deferred_free) { 1500 pr_alert("%s: gp_normal without primitives.\n", __func__); 1501 } 1502 if (gp_poll1 && cur_ops->get_comp_state && cur_ops->same_gp_state && 1503 cur_ops->start_gp_poll && cur_ops->poll_gp_state) { 1504 synctype[nsynctypes++] = RTWS_POLL_GET; 1505 pr_info("%s: Testing polling GPs.\n", __func__); 1506 } else if (gp_poll && (!cur_ops->start_gp_poll || !cur_ops->poll_gp_state)) { 1507 pr_alert("%s: gp_poll without primitives.\n", __func__); 1508 } 1509 if (gp_poll_full1 && cur_ops->get_comp_state_full && cur_ops->same_gp_state_full 1510 && cur_ops->start_gp_poll_full && cur_ops->poll_gp_state_full) { 1511 synctype[nsynctypes++] = RTWS_POLL_GET_FULL; 1512 pr_info("%s: Testing polling full-state GPs.\n", __func__); 1513 } else if (gp_poll_full && (!cur_ops->start_gp_poll_full || !cur_ops->poll_gp_state_full)) { 1514 pr_alert("%s: gp_poll_full without primitives.\n", __func__); 1515 } 1516 if (gp_poll_exp1 && cur_ops->start_gp_poll_exp && cur_ops->poll_gp_state_exp) { 1517 synctype[nsynctypes++] = RTWS_POLL_GET_EXP; 1518 pr_info("%s: Testing polling expedited GPs.\n", __func__); 1519 } else if (gp_poll_exp && (!cur_ops->start_gp_poll_exp || !cur_ops->poll_gp_state_exp)) { 1520 pr_alert("%s: gp_poll_exp without primitives.\n", __func__); 1521 } 1522 if (gp_poll_exp_full1 && cur_ops->start_gp_poll_exp_full && cur_ops->poll_gp_state_full) { 1523 synctype[nsynctypes++] = RTWS_POLL_GET_EXP_FULL; 1524 pr_info("%s: Testing polling full-state expedited GPs.\n", __func__); 1525 } else if (gp_poll_exp_full && 1526 (!cur_ops->start_gp_poll_exp_full || !cur_ops->poll_gp_state_full)) { 1527 pr_alert("%s: gp_poll_exp_full without primitives.\n", __func__); 1528 } 1529 if (gp_sync1 && cur_ops->sync) { 1530 synctype[nsynctypes++] = RTWS_SYNC; 1531 pr_info("%s: Testing normal GPs.\n", __func__); 1532 } else if (gp_sync && !cur_ops->sync) { 1533 pr_alert("%s: gp_sync without primitives.\n", __func__); 1534 } 1535 pr_alert("%s: Testing %d update types.\n", __func__, nsynctypes); 1536 pr_info("%s: gp_cond_wi %d gp_cond_wi_exp %d gp_poll_wi %d gp_poll_wi_exp %d\n", __func__, gp_cond_wi, gp_cond_wi_exp, gp_poll_wi, gp_poll_wi_exp); 1537 } 1538 1539 /* 1540 * Do the specified rcu_torture_writer() synchronous grace period, 1541 * while also testing out the polled APIs. Note well that the single-CPU 1542 * grace-period optimizations must be accounted for. 1543 */ 1544 static void do_rtws_sync(struct torture_random_state *trsp, void (*sync)(void)) 1545 { 1546 unsigned long cookie; 1547 struct rcu_gp_oldstate cookie_full; 1548 bool dopoll; 1549 bool dopoll_full; 1550 unsigned long r = torture_random(trsp); 1551 1552 dopoll = cur_ops->get_gp_state && cur_ops->poll_gp_state && !(r & 0x300); 1553 dopoll_full = cur_ops->get_gp_state_full && cur_ops->poll_gp_state_full && !(r & 0xc00); 1554 if (dopoll || dopoll_full) 1555 cpus_read_lock(); 1556 if (dopoll) 1557 cookie = cur_ops->get_gp_state(); 1558 if (dopoll_full) 1559 cur_ops->get_gp_state_full(&cookie_full); 1560 if (cur_ops->poll_need_2gp && cur_ops->poll_need_2gp(dopoll, dopoll_full)) 1561 sync(); 1562 sync(); 1563 WARN_ONCE(dopoll && !cur_ops->poll_gp_state(cookie), 1564 "%s: Cookie check 3 failed %pS() online %*pbl.", 1565 __func__, sync, cpumask_pr_args(cpu_online_mask)); 1566 WARN_ONCE(dopoll_full && !cur_ops->poll_gp_state_full(&cookie_full), 1567 "%s: Cookie check 4 failed %pS() online %*pbl", 1568 __func__, sync, cpumask_pr_args(cpu_online_mask)); 1569 if (dopoll || dopoll_full) 1570 cpus_read_unlock(); 1571 } 1572 1573 /* 1574 * RCU torture writer kthread. Repeatedly substitutes a new structure 1575 * for that pointed to by rcu_torture_current, freeing the old structure 1576 * after a series of grace periods (the "pipeline"). 1577 */ 1578 static int 1579 rcu_torture_writer(void *arg) 1580 { 1581 bool booting_still = false; 1582 bool can_expedite = !rcu_gp_is_expedited() && !rcu_gp_is_normal(); 1583 unsigned long cookie; 1584 struct rcu_gp_oldstate cookie_full; 1585 int expediting = 0; 1586 unsigned long gp_snap; 1587 unsigned long gp_snap1; 1588 struct rcu_gp_oldstate gp_snap_full; 1589 struct rcu_gp_oldstate gp_snap1_full; 1590 int i; 1591 int idx; 1592 unsigned long j; 1593 int oldnice = task_nice(current); 1594 struct rcu_gp_oldstate *rgo = NULL; 1595 int rgo_size = 0; 1596 struct rcu_torture *rp; 1597 struct rcu_torture *old_rp; 1598 static DEFINE_TORTURE_RANDOM(rand); 1599 unsigned long stallsdone = jiffies; 1600 bool stutter_waited; 1601 unsigned long *ulo = NULL; 1602 int ulo_size = 0; 1603 1604 // If a new stall test is added, this must be adjusted. 1605 if (stall_cpu_holdoff + stall_gp_kthread + stall_cpu) 1606 stallsdone += (stall_cpu_holdoff + stall_gp_kthread + stall_cpu + 60) * 1607 HZ * (stall_cpu_repeat + 1); 1608 VERBOSE_TOROUT_STRING("rcu_torture_writer task started"); 1609 if (!can_expedite) 1610 pr_alert("%s" TORTURE_FLAG 1611 " GP expediting controlled from boot/sysfs for %s.\n", 1612 torture_type, cur_ops->name); 1613 if (WARN_ONCE(nsynctypes == 0, 1614 "%s: No update-side primitives.\n", __func__)) { 1615 /* 1616 * No updates primitives, so don't try updating. 1617 * The resulting test won't be testing much, hence the 1618 * above WARN_ONCE(). 1619 */ 1620 rcu_torture_writer_state = RTWS_STOPPING; 1621 torture_kthread_stopping("rcu_torture_writer"); 1622 return 0; 1623 } 1624 if (cur_ops->poll_active > 0) { 1625 ulo = kcalloc(cur_ops->poll_active, sizeof(*ulo), GFP_KERNEL); 1626 if (!WARN_ON(!ulo)) 1627 ulo_size = cur_ops->poll_active; 1628 } 1629 if (cur_ops->poll_active_full > 0) { 1630 rgo = kcalloc(cur_ops->poll_active_full, sizeof(*rgo), GFP_KERNEL); 1631 if (!WARN_ON(!rgo)) 1632 rgo_size = cur_ops->poll_active_full; 1633 } 1634 1635 // If the system is still booting, let it finish. 1636 j = jiffies; 1637 while (!torture_must_stop() && !rcu_inkernel_boot_has_ended()) { 1638 booting_still = true; 1639 schedule_timeout_interruptible(HZ); 1640 } 1641 if (booting_still) 1642 pr_alert("%s" TORTURE_FLAG " Waited %lu jiffies for boot to complete.\n", 1643 torture_type, jiffies - j); 1644 1645 do { 1646 rcu_torture_writer_state = RTWS_FIXED_DELAY; 1647 torture_hrtimeout_us(500, 1000, &rand); 1648 rp = rcu_torture_alloc(); 1649 if (rp == NULL) 1650 continue; 1651 rp->rtort_pipe_count = 0; 1652 ASSERT_EXCLUSIVE_WRITER(rp->rtort_pipe_count); 1653 rcu_torture_writer_state = RTWS_DELAY; 1654 udelay(torture_random(&rand) & 0x3ff); 1655 rcu_torture_writer_state = RTWS_REPLACE; 1656 old_rp = rcu_dereference_check(rcu_torture_current, 1657 current == writer_task); 1658 rp->rtort_mbtest = 1; 1659 rcu_assign_pointer(rcu_torture_current, rp); 1660 smp_wmb(); /* Mods to old_rp must follow rcu_assign_pointer() */ 1661 if (old_rp) { 1662 i = old_rp->rtort_pipe_count; 1663 if (i > RCU_TORTURE_PIPE_LEN) 1664 i = RCU_TORTURE_PIPE_LEN; 1665 atomic_inc(&rcu_torture_wcount[i]); 1666 WRITE_ONCE(old_rp->rtort_pipe_count, 1667 old_rp->rtort_pipe_count + 1); 1668 ASSERT_EXCLUSIVE_WRITER(old_rp->rtort_pipe_count); 1669 1670 // Make sure readers block polled grace periods. 1671 if (cur_ops->get_gp_state && cur_ops->poll_gp_state) { 1672 idx = cur_ops->readlock(); 1673 cookie = cur_ops->get_gp_state(); 1674 WARN_ONCE(cur_ops->poll_gp_state(cookie), 1675 "%s: Cookie check 1 failed %s(%d) %lu->%lu\n", 1676 __func__, 1677 rcu_torture_writer_state_getname(), 1678 rcu_torture_writer_state, 1679 cookie, cur_ops->get_gp_state()); 1680 if (cur_ops->get_comp_state) { 1681 cookie = cur_ops->get_comp_state(); 1682 WARN_ON_ONCE(!cur_ops->poll_gp_state(cookie)); 1683 } 1684 cur_ops->readunlock(idx); 1685 } 1686 if (cur_ops->get_gp_state_full && cur_ops->poll_gp_state_full) { 1687 idx = cur_ops->readlock(); 1688 cur_ops->get_gp_state_full(&cookie_full); 1689 WARN_ONCE(cur_ops->poll_gp_state_full(&cookie_full), 1690 "%s: Cookie check 5 failed %s(%d) online %*pbl\n", 1691 __func__, 1692 rcu_torture_writer_state_getname(), 1693 rcu_torture_writer_state, 1694 cpumask_pr_args(cpu_online_mask)); 1695 if (cur_ops->get_comp_state_full) { 1696 cur_ops->get_comp_state_full(&cookie_full); 1697 WARN_ON_ONCE(!cur_ops->poll_gp_state_full(&cookie_full)); 1698 } 1699 cur_ops->readunlock(idx); 1700 } 1701 switch (synctype[torture_random(&rand) % nsynctypes]) { 1702 case RTWS_DEF_FREE: 1703 rcu_torture_writer_state = RTWS_DEF_FREE; 1704 cur_ops->deferred_free(old_rp); 1705 break; 1706 case RTWS_EXP_SYNC: 1707 rcu_torture_writer_state = RTWS_EXP_SYNC; 1708 do_rtws_sync(&rand, cur_ops->exp_sync); 1709 rcu_torture_pipe_update(old_rp); 1710 break; 1711 case RTWS_COND_GET: 1712 rcu_torture_writer_state = RTWS_COND_GET; 1713 gp_snap = cur_ops->get_gp_state(); 1714 torture_hrtimeout_us(torture_random(&rand) % gp_cond_wi, 1715 1000, &rand); 1716 rcu_torture_writer_state = RTWS_COND_SYNC; 1717 cur_ops->cond_sync(gp_snap); 1718 rcu_torture_pipe_update(old_rp); 1719 break; 1720 case RTWS_COND_GET_EXP: 1721 rcu_torture_writer_state = RTWS_COND_GET_EXP; 1722 gp_snap = cur_ops->get_gp_state_exp(); 1723 torture_hrtimeout_us(torture_random(&rand) % gp_cond_wi_exp, 1724 1000, &rand); 1725 rcu_torture_writer_state = RTWS_COND_SYNC_EXP; 1726 cur_ops->cond_sync_exp(gp_snap); 1727 rcu_torture_pipe_update(old_rp); 1728 break; 1729 case RTWS_COND_GET_FULL: 1730 rcu_torture_writer_state = RTWS_COND_GET_FULL; 1731 cur_ops->get_gp_state_full(&gp_snap_full); 1732 torture_hrtimeout_us(torture_random(&rand) % gp_cond_wi, 1733 1000, &rand); 1734 rcu_torture_writer_state = RTWS_COND_SYNC_FULL; 1735 cur_ops->cond_sync_full(&gp_snap_full); 1736 rcu_torture_pipe_update(old_rp); 1737 break; 1738 case RTWS_COND_GET_EXP_FULL: 1739 rcu_torture_writer_state = RTWS_COND_GET_EXP_FULL; 1740 cur_ops->get_gp_state_full(&gp_snap_full); 1741 torture_hrtimeout_us(torture_random(&rand) % gp_cond_wi_exp, 1742 1000, &rand); 1743 rcu_torture_writer_state = RTWS_COND_SYNC_EXP_FULL; 1744 cur_ops->cond_sync_exp_full(&gp_snap_full); 1745 rcu_torture_pipe_update(old_rp); 1746 break; 1747 case RTWS_POLL_GET: 1748 rcu_torture_writer_state = RTWS_POLL_GET; 1749 for (i = 0; i < ulo_size; i++) 1750 ulo[i] = cur_ops->get_comp_state(); 1751 gp_snap = cur_ops->start_gp_poll(); 1752 rcu_torture_writer_state = RTWS_POLL_WAIT; 1753 if (cur_ops->exp_current && !torture_random(&rand) % 0xff) 1754 cur_ops->exp_current(); 1755 while (!cur_ops->poll_gp_state(gp_snap)) { 1756 gp_snap1 = cur_ops->get_gp_state(); 1757 for (i = 0; i < ulo_size; i++) 1758 if (cur_ops->poll_gp_state(ulo[i]) || 1759 cur_ops->same_gp_state(ulo[i], gp_snap1)) { 1760 ulo[i] = gp_snap1; 1761 break; 1762 } 1763 WARN_ON_ONCE(ulo_size > 0 && i >= ulo_size); 1764 torture_hrtimeout_us(torture_random(&rand) % gp_poll_wi, 1765 1000, &rand); 1766 } 1767 rcu_torture_pipe_update(old_rp); 1768 break; 1769 case RTWS_POLL_GET_FULL: 1770 rcu_torture_writer_state = RTWS_POLL_GET_FULL; 1771 for (i = 0; i < rgo_size; i++) 1772 cur_ops->get_comp_state_full(&rgo[i]); 1773 cur_ops->start_gp_poll_full(&gp_snap_full); 1774 rcu_torture_writer_state = RTWS_POLL_WAIT_FULL; 1775 if (cur_ops->exp_current && !torture_random(&rand) % 0xff) 1776 cur_ops->exp_current(); 1777 while (!cur_ops->poll_gp_state_full(&gp_snap_full)) { 1778 cur_ops->get_gp_state_full(&gp_snap1_full); 1779 for (i = 0; i < rgo_size; i++) 1780 if (cur_ops->poll_gp_state_full(&rgo[i]) || 1781 cur_ops->same_gp_state_full(&rgo[i], 1782 &gp_snap1_full)) { 1783 rgo[i] = gp_snap1_full; 1784 break; 1785 } 1786 WARN_ON_ONCE(rgo_size > 0 && i >= rgo_size); 1787 torture_hrtimeout_us(torture_random(&rand) % gp_poll_wi, 1788 1000, &rand); 1789 } 1790 rcu_torture_pipe_update(old_rp); 1791 break; 1792 case RTWS_POLL_GET_EXP: 1793 rcu_torture_writer_state = RTWS_POLL_GET_EXP; 1794 gp_snap = cur_ops->start_gp_poll_exp(); 1795 rcu_torture_writer_state = RTWS_POLL_WAIT_EXP; 1796 while (!cur_ops->poll_gp_state_exp(gp_snap)) 1797 torture_hrtimeout_us(torture_random(&rand) % gp_poll_wi_exp, 1798 1000, &rand); 1799 rcu_torture_pipe_update(old_rp); 1800 break; 1801 case RTWS_POLL_GET_EXP_FULL: 1802 rcu_torture_writer_state = RTWS_POLL_GET_EXP_FULL; 1803 cur_ops->start_gp_poll_exp_full(&gp_snap_full); 1804 rcu_torture_writer_state = RTWS_POLL_WAIT_EXP_FULL; 1805 while (!cur_ops->poll_gp_state_full(&gp_snap_full)) 1806 torture_hrtimeout_us(torture_random(&rand) % gp_poll_wi_exp, 1807 1000, &rand); 1808 rcu_torture_pipe_update(old_rp); 1809 break; 1810 case RTWS_SYNC: 1811 rcu_torture_writer_state = RTWS_SYNC; 1812 do_rtws_sync(&rand, cur_ops->sync); 1813 rcu_torture_pipe_update(old_rp); 1814 break; 1815 default: 1816 WARN_ON_ONCE(1); 1817 break; 1818 } 1819 } 1820 WRITE_ONCE(rcu_torture_current_version, 1821 rcu_torture_current_version + 1); 1822 /* Cycle through nesting levels of rcu_expedite_gp() calls. */ 1823 if (can_expedite && 1824 !(torture_random(&rand) & 0xff & (!!expediting - 1))) { 1825 WARN_ON_ONCE(expediting == 0 && rcu_gp_is_expedited()); 1826 if (expediting >= 0) 1827 rcu_expedite_gp(); 1828 else 1829 rcu_unexpedite_gp(); 1830 if (++expediting > 3) 1831 expediting = -expediting; 1832 } else if (!can_expedite) { /* Disabled during boot, recheck. */ 1833 can_expedite = !rcu_gp_is_expedited() && 1834 !rcu_gp_is_normal(); 1835 } 1836 rcu_torture_writer_state = RTWS_STUTTER; 1837 stutter_waited = stutter_wait("rcu_torture_writer"); 1838 if (stutter_waited && 1839 !atomic_read(&rcu_fwd_cb_nodelay) && 1840 !cur_ops->slow_gps && 1841 !torture_must_stop() && 1842 time_after(jiffies, stallsdone)) 1843 for (i = 0; i < ARRAY_SIZE(rcu_tortures); i++) 1844 if (list_empty(&rcu_tortures[i].rtort_free) && 1845 rcu_access_pointer(rcu_torture_current) != &rcu_tortures[i]) { 1846 tracing_off(); 1847 if (cur_ops->gp_kthread_dbg) 1848 cur_ops->gp_kthread_dbg(); 1849 WARN(1, "%s: rtort_pipe_count: %d\n", __func__, rcu_tortures[i].rtort_pipe_count); 1850 rcu_ftrace_dump(DUMP_ALL); 1851 break; 1852 } 1853 if (stutter_waited) 1854 sched_set_normal(current, oldnice); 1855 } while (!torture_must_stop()); 1856 rcu_torture_current = NULL; // Let stats task know that we are done. 1857 /* Reset expediting back to unexpedited. */ 1858 if (expediting > 0) 1859 expediting = -expediting; 1860 while (can_expedite && expediting++ < 0) 1861 rcu_unexpedite_gp(); 1862 WARN_ON_ONCE(can_expedite && rcu_gp_is_expedited()); 1863 if (!can_expedite) 1864 pr_alert("%s" TORTURE_FLAG 1865 " Dynamic grace-period expediting was disabled.\n", 1866 torture_type); 1867 kfree(ulo); 1868 kfree(rgo); 1869 rcu_torture_writer_state = RTWS_STOPPING; 1870 torture_kthread_stopping("rcu_torture_writer"); 1871 return 0; 1872 } 1873 1874 /* 1875 * RCU torture fake writer kthread. Repeatedly calls sync, with a random 1876 * delay between calls. 1877 */ 1878 static int 1879 rcu_torture_fakewriter(void *arg) 1880 { 1881 unsigned long gp_snap; 1882 struct rcu_gp_oldstate gp_snap_full; 1883 DEFINE_TORTURE_RANDOM(rand); 1884 1885 VERBOSE_TOROUT_STRING("rcu_torture_fakewriter task started"); 1886 set_user_nice(current, MAX_NICE); 1887 1888 if (WARN_ONCE(nsynctypes == 0, 1889 "%s: No update-side primitives.\n", __func__)) { 1890 /* 1891 * No updates primitives, so don't try updating. 1892 * The resulting test won't be testing much, hence the 1893 * above WARN_ONCE(). 1894 */ 1895 torture_kthread_stopping("rcu_torture_fakewriter"); 1896 return 0; 1897 } 1898 1899 do { 1900 torture_hrtimeout_jiffies(torture_random(&rand) % 10, &rand); 1901 if (cur_ops->cb_barrier != NULL && 1902 torture_random(&rand) % (nrealfakewriters * 8) == 0) { 1903 cur_ops->cb_barrier(); 1904 } else { 1905 switch (synctype[torture_random(&rand) % nsynctypes]) { 1906 case RTWS_DEF_FREE: 1907 break; 1908 case RTWS_EXP_SYNC: 1909 cur_ops->exp_sync(); 1910 break; 1911 case RTWS_COND_GET: 1912 gp_snap = cur_ops->get_gp_state(); 1913 torture_hrtimeout_jiffies(torture_random(&rand) % 16, &rand); 1914 cur_ops->cond_sync(gp_snap); 1915 break; 1916 case RTWS_COND_GET_EXP: 1917 gp_snap = cur_ops->get_gp_state_exp(); 1918 torture_hrtimeout_jiffies(torture_random(&rand) % 16, &rand); 1919 cur_ops->cond_sync_exp(gp_snap); 1920 break; 1921 case RTWS_COND_GET_FULL: 1922 cur_ops->get_gp_state_full(&gp_snap_full); 1923 torture_hrtimeout_jiffies(torture_random(&rand) % 16, &rand); 1924 cur_ops->cond_sync_full(&gp_snap_full); 1925 break; 1926 case RTWS_COND_GET_EXP_FULL: 1927 cur_ops->get_gp_state_full(&gp_snap_full); 1928 torture_hrtimeout_jiffies(torture_random(&rand) % 16, &rand); 1929 cur_ops->cond_sync_exp_full(&gp_snap_full); 1930 break; 1931 case RTWS_POLL_GET: 1932 if (cur_ops->start_poll_irqsoff) 1933 local_irq_disable(); 1934 gp_snap = cur_ops->start_gp_poll(); 1935 if (cur_ops->start_poll_irqsoff) 1936 local_irq_enable(); 1937 while (!cur_ops->poll_gp_state(gp_snap)) { 1938 torture_hrtimeout_jiffies(torture_random(&rand) % 16, 1939 &rand); 1940 } 1941 break; 1942 case RTWS_POLL_GET_FULL: 1943 if (cur_ops->start_poll_irqsoff) 1944 local_irq_disable(); 1945 cur_ops->start_gp_poll_full(&gp_snap_full); 1946 if (cur_ops->start_poll_irqsoff) 1947 local_irq_enable(); 1948 while (!cur_ops->poll_gp_state_full(&gp_snap_full)) { 1949 torture_hrtimeout_jiffies(torture_random(&rand) % 16, 1950 &rand); 1951 } 1952 break; 1953 case RTWS_POLL_GET_EXP: 1954 gp_snap = cur_ops->start_gp_poll_exp(); 1955 while (!cur_ops->poll_gp_state_exp(gp_snap)) { 1956 torture_hrtimeout_jiffies(torture_random(&rand) % 16, 1957 &rand); 1958 } 1959 break; 1960 case RTWS_POLL_GET_EXP_FULL: 1961 cur_ops->start_gp_poll_exp_full(&gp_snap_full); 1962 while (!cur_ops->poll_gp_state_full(&gp_snap_full)) { 1963 torture_hrtimeout_jiffies(torture_random(&rand) % 16, 1964 &rand); 1965 } 1966 break; 1967 case RTWS_SYNC: 1968 cur_ops->sync(); 1969 break; 1970 default: 1971 WARN_ON_ONCE(1); 1972 break; 1973 } 1974 } 1975 stutter_wait("rcu_torture_fakewriter"); 1976 } while (!torture_must_stop()); 1977 1978 torture_kthread_stopping("rcu_torture_fakewriter"); 1979 return 0; 1980 } 1981 1982 static void rcu_torture_timer_cb(struct rcu_head *rhp) 1983 { 1984 kfree(rhp); 1985 } 1986 1987 // Set up and carry out testing of RCU's global memory ordering 1988 static void rcu_torture_reader_do_mbchk(long myid, struct rcu_torture *rtp, 1989 struct torture_random_state *trsp) 1990 { 1991 unsigned long loops; 1992 int noc = torture_num_online_cpus(); 1993 int rdrchked; 1994 int rdrchker; 1995 struct rcu_torture_reader_check *rtrcp; // Me. 1996 struct rcu_torture_reader_check *rtrcp_assigner; // Assigned us to do checking. 1997 struct rcu_torture_reader_check *rtrcp_chked; // Reader being checked. 1998 struct rcu_torture_reader_check *rtrcp_chker; // Reader doing checking when not me. 1999 2000 if (myid < 0) 2001 return; // Don't try this from timer handlers. 2002 2003 // Increment my counter. 2004 rtrcp = &rcu_torture_reader_mbchk[myid]; 2005 WRITE_ONCE(rtrcp->rtc_myloops, rtrcp->rtc_myloops + 1); 2006 2007 // Attempt to assign someone else some checking work. 2008 rdrchked = torture_random(trsp) % nrealreaders; 2009 rtrcp_chked = &rcu_torture_reader_mbchk[rdrchked]; 2010 rdrchker = torture_random(trsp) % nrealreaders; 2011 rtrcp_chker = &rcu_torture_reader_mbchk[rdrchker]; 2012 if (rdrchked != myid && rdrchked != rdrchker && noc >= rdrchked && noc >= rdrchker && 2013 smp_load_acquire(&rtrcp->rtc_chkrdr) < 0 && // Pairs with smp_store_release below. 2014 !READ_ONCE(rtp->rtort_chkp) && 2015 !smp_load_acquire(&rtrcp_chker->rtc_assigner)) { // Pairs with smp_store_release below. 2016 rtrcp->rtc_chkloops = READ_ONCE(rtrcp_chked->rtc_myloops); 2017 WARN_ON_ONCE(rtrcp->rtc_chkrdr >= 0); 2018 rtrcp->rtc_chkrdr = rdrchked; 2019 WARN_ON_ONCE(rtrcp->rtc_ready); // This gets set after the grace period ends. 2020 if (cmpxchg_relaxed(&rtrcp_chker->rtc_assigner, NULL, rtrcp) || 2021 cmpxchg_relaxed(&rtp->rtort_chkp, NULL, rtrcp)) 2022 (void)cmpxchg_relaxed(&rtrcp_chker->rtc_assigner, rtrcp, NULL); // Back out. 2023 } 2024 2025 // If assigned some completed work, do it! 2026 rtrcp_assigner = READ_ONCE(rtrcp->rtc_assigner); 2027 if (!rtrcp_assigner || !smp_load_acquire(&rtrcp_assigner->rtc_ready)) 2028 return; // No work or work not yet ready. 2029 rdrchked = rtrcp_assigner->rtc_chkrdr; 2030 if (WARN_ON_ONCE(rdrchked < 0)) 2031 return; 2032 rtrcp_chked = &rcu_torture_reader_mbchk[rdrchked]; 2033 loops = READ_ONCE(rtrcp_chked->rtc_myloops); 2034 atomic_inc(&n_rcu_torture_mbchk_tries); 2035 if (ULONG_CMP_LT(loops, rtrcp_assigner->rtc_chkloops)) 2036 atomic_inc(&n_rcu_torture_mbchk_fail); 2037 rtrcp_assigner->rtc_chkloops = loops + ULONG_MAX / 2; 2038 rtrcp_assigner->rtc_ready = 0; 2039 smp_store_release(&rtrcp->rtc_assigner, NULL); // Someone else can assign us work. 2040 smp_store_release(&rtrcp_assigner->rtc_chkrdr, -1); // Assigner can again assign. 2041 } 2042 2043 // Verify the specified RCUTORTURE_RDR* state. 2044 #define ROEC_ARGS "%s %s: Current %#x To add %#x To remove %#x preempt_count() %#x\n", __func__, s, curstate, new, old, preempt_count() 2045 static void rcutorture_one_extend_check(char *s, int curstate, int new, int old) 2046 { 2047 int mask; 2048 2049 if (!IS_ENABLED(CONFIG_RCU_TORTURE_TEST_CHK_RDR_STATE) || in_nmi()) 2050 return; 2051 2052 WARN_ONCE(!(curstate & RCUTORTURE_RDR_IRQ) && irqs_disabled() && !in_hardirq(), ROEC_ARGS); 2053 WARN_ONCE((curstate & RCUTORTURE_RDR_IRQ) && !irqs_disabled(), ROEC_ARGS); 2054 2055 // If CONFIG_PREEMPT_COUNT=n, further checks are unreliable. 2056 if (!IS_ENABLED(CONFIG_PREEMPT_COUNT)) 2057 return; 2058 2059 WARN_ONCE((curstate & (RCUTORTURE_RDR_BH | RCUTORTURE_RDR_RBH)) && 2060 !softirq_count(), ROEC_ARGS); 2061 WARN_ONCE((curstate & (RCUTORTURE_RDR_PREEMPT | RCUTORTURE_RDR_SCHED)) && 2062 !(preempt_count() & PREEMPT_MASK), ROEC_ARGS); 2063 WARN_ONCE(cur_ops->readlock_nesting && 2064 (curstate & (RCUTORTURE_RDR_RCU_1 | RCUTORTURE_RDR_RCU_2)) && 2065 cur_ops->readlock_nesting() == 0, ROEC_ARGS); 2066 2067 // Interrupt handlers have all sorts of stuff disabled, so ignore 2068 // unintended disabling. 2069 if (in_serving_softirq() || in_hardirq()) 2070 return; 2071 2072 WARN_ONCE(cur_ops->extendables && 2073 !(curstate & (RCUTORTURE_RDR_BH | RCUTORTURE_RDR_RBH)) && 2074 softirq_count(), ROEC_ARGS); 2075 2076 /* 2077 * non-preemptible RCU in a preemptible kernel uses preempt_disable() 2078 * as rcu_read_lock(). 2079 */ 2080 mask = RCUTORTURE_RDR_PREEMPT | RCUTORTURE_RDR_SCHED; 2081 if (!IS_ENABLED(CONFIG_PREEMPT_RCU)) 2082 mask |= RCUTORTURE_RDR_RCU_1 | RCUTORTURE_RDR_RCU_2; 2083 2084 WARN_ONCE(cur_ops->extendables && !(curstate & mask) && 2085 (preempt_count() & PREEMPT_MASK), ROEC_ARGS); 2086 2087 /* 2088 * non-preemptible RCU in a preemptible kernel uses "preempt_count() & 2089 * PREEMPT_MASK" as ->readlock_nesting(). 2090 */ 2091 mask = RCUTORTURE_RDR_RCU_1 | RCUTORTURE_RDR_RCU_2; 2092 if (!IS_ENABLED(CONFIG_PREEMPT_RCU)) 2093 mask |= RCUTORTURE_RDR_PREEMPT | RCUTORTURE_RDR_SCHED; 2094 2095 if (IS_ENABLED(CONFIG_PREEMPT_RT) && softirq_count()) 2096 mask |= RCUTORTURE_RDR_BH | RCUTORTURE_RDR_RBH; 2097 2098 WARN_ONCE(cur_ops->readlock_nesting && !(curstate & mask) && 2099 cur_ops->readlock_nesting() > 0, ROEC_ARGS); 2100 } 2101 2102 /* 2103 * Do one extension of an RCU read-side critical section using the 2104 * current reader state in readstate (set to zero for initial entry 2105 * to extended critical section), set the new state as specified by 2106 * newstate (set to zero for final exit from extended critical section), 2107 * and random-number-generator state in trsp. If this is neither the 2108 * beginning or end of the critical section and if there was actually a 2109 * change, do a ->read_delay(). 2110 */ 2111 static void rcutorture_one_extend(int *readstate, int newstate, struct torture_random_state *trsp, 2112 struct rt_read_seg *rtrsp) 2113 { 2114 bool first; 2115 unsigned long flags; 2116 int idxnew1 = -1; 2117 int idxnew2 = -1; 2118 int idxold1 = *readstate; 2119 int idxold2 = idxold1; 2120 int statesnew = ~*readstate & newstate; 2121 int statesold = *readstate & ~newstate; 2122 2123 first = idxold1 == 0; 2124 WARN_ON_ONCE(idxold2 < 0); 2125 WARN_ON_ONCE(idxold2 & ~(RCUTORTURE_RDR_ALLBITS | RCUTORTURE_RDR_UPDOWN)); 2126 rcutorture_one_extend_check("before change", idxold1, statesnew, statesold); 2127 rtrsp->rt_readstate = newstate; 2128 2129 /* First, put new protection in place to avoid critical-section gap. */ 2130 if (statesnew & RCUTORTURE_RDR_BH) 2131 local_bh_disable(); 2132 if (statesnew & RCUTORTURE_RDR_RBH) 2133 rcu_read_lock_bh(); 2134 if (statesnew & RCUTORTURE_RDR_IRQ) 2135 local_irq_disable(); 2136 if (statesnew & RCUTORTURE_RDR_PREEMPT) 2137 preempt_disable(); 2138 if (statesnew & RCUTORTURE_RDR_SCHED) 2139 rcu_read_lock_sched(); 2140 if (statesnew & RCUTORTURE_RDR_RCU_1) 2141 idxnew1 = (cur_ops->readlock() << RCUTORTURE_RDR_SHIFT_1) & RCUTORTURE_RDR_MASK_1; 2142 if (statesnew & RCUTORTURE_RDR_RCU_2) 2143 idxnew2 = (cur_ops->readlock() << RCUTORTURE_RDR_SHIFT_2) & RCUTORTURE_RDR_MASK_2; 2144 2145 // Complain unless both the old and the new protection is in place. 2146 rcutorture_one_extend_check("during change", idxold1 | statesnew, statesnew, statesold); 2147 2148 // Sample CPU under both sets of protections to reduce confusion. 2149 if (IS_ENABLED(CONFIG_RCU_TORTURE_TEST_LOG_CPU)) { 2150 int cpu = raw_smp_processor_id(); 2151 rtrsp->rt_cpu = cpu; 2152 if (!first) { 2153 rtrsp[-1].rt_end_cpu = cpu; 2154 if (cur_ops->reader_blocked) 2155 rtrsp[-1].rt_preempted = cur_ops->reader_blocked(); 2156 } 2157 } 2158 // Sample grace-period sequence number, as good a place as any. 2159 if (IS_ENABLED(CONFIG_RCU_TORTURE_TEST_LOG_GP) && cur_ops->gather_gp_seqs) { 2160 rtrsp->rt_gp_seq = cur_ops->gather_gp_seqs(); 2161 rtrsp->rt_ts = ktime_get_mono_fast_ns(); 2162 if (!first) 2163 rtrsp[-1].rt_gp_seq_end = rtrsp->rt_gp_seq; 2164 } 2165 2166 /* 2167 * Next, remove old protection, in decreasing order of strength 2168 * to avoid unlock paths that aren't safe in the stronger 2169 * context. Namely: BH can not be enabled with disabled interrupts. 2170 * Additionally PREEMPT_RT requires that BH is enabled in preemptible 2171 * context. 2172 */ 2173 if (statesold & RCUTORTURE_RDR_IRQ) 2174 local_irq_enable(); 2175 if (statesold & RCUTORTURE_RDR_PREEMPT) 2176 preempt_enable(); 2177 if (statesold & RCUTORTURE_RDR_SCHED) 2178 rcu_read_unlock_sched(); 2179 if (statesold & RCUTORTURE_RDR_BH) 2180 local_bh_enable(); 2181 if (statesold & RCUTORTURE_RDR_RBH) 2182 rcu_read_unlock_bh(); 2183 if (statesold & RCUTORTURE_RDR_RCU_2) { 2184 cur_ops->readunlock((idxold2 & RCUTORTURE_RDR_MASK_2) >> RCUTORTURE_RDR_SHIFT_2); 2185 WARN_ON_ONCE(idxnew2 != -1); 2186 idxold2 = 0; 2187 } 2188 if (statesold & RCUTORTURE_RDR_RCU_1) { 2189 bool lockit; 2190 2191 lockit = !cur_ops->no_pi_lock && !statesnew && !(torture_random(trsp) & 0xffff); 2192 if (lockit) 2193 raw_spin_lock_irqsave(¤t->pi_lock, flags); 2194 cur_ops->readunlock((idxold1 & RCUTORTURE_RDR_MASK_1) >> RCUTORTURE_RDR_SHIFT_1); 2195 WARN_ON_ONCE(idxnew1 != -1); 2196 idxold1 = 0; 2197 if (lockit) 2198 raw_spin_unlock_irqrestore(¤t->pi_lock, flags); 2199 } 2200 if (statesold & RCUTORTURE_RDR_UPDOWN) { 2201 cur_ops->up_read((idxold1 & RCUTORTURE_RDR_MASK_1) >> RCUTORTURE_RDR_SHIFT_1); 2202 WARN_ON_ONCE(idxnew1 != -1); 2203 idxold1 = 0; 2204 } 2205 2206 /* Delay if neither beginning nor end and there was a change. */ 2207 if ((statesnew || statesold) && *readstate && newstate) 2208 cur_ops->read_delay(trsp, rtrsp); 2209 2210 /* Update the reader state. */ 2211 if (idxnew1 == -1) 2212 idxnew1 = idxold1 & RCUTORTURE_RDR_MASK_1; 2213 WARN_ON_ONCE(idxnew1 < 0); 2214 if (idxnew2 == -1) 2215 idxnew2 = idxold2 & RCUTORTURE_RDR_MASK_2; 2216 WARN_ON_ONCE(idxnew2 < 0); 2217 *readstate = idxnew1 | idxnew2 | newstate; 2218 WARN_ON_ONCE(*readstate < 0); 2219 if (WARN_ON_ONCE(*readstate & ~RCUTORTURE_RDR_ALLBITS)) 2220 pr_info("Unexpected readstate value of %#x\n", *readstate); 2221 rcutorture_one_extend_check("after change", *readstate, statesnew, statesold); 2222 } 2223 2224 /* Return the biggest extendables mask given current RCU and boot parameters. */ 2225 static int rcutorture_extend_mask_max(void) 2226 { 2227 int mask; 2228 2229 WARN_ON_ONCE(extendables & ~RCUTORTURE_MAX_EXTEND); 2230 mask = extendables & RCUTORTURE_MAX_EXTEND & cur_ops->extendables; 2231 mask = mask | RCUTORTURE_RDR_RCU_1 | RCUTORTURE_RDR_RCU_2; 2232 return mask; 2233 } 2234 2235 /* Return a random protection state mask, but with at least one bit set. */ 2236 static int 2237 rcutorture_extend_mask(int oldmask, struct torture_random_state *trsp) 2238 { 2239 int mask = rcutorture_extend_mask_max(); 2240 unsigned long randmask1 = torture_random(trsp); 2241 unsigned long randmask2 = randmask1 >> 3; 2242 unsigned long preempts = RCUTORTURE_RDR_PREEMPT | RCUTORTURE_RDR_SCHED; 2243 unsigned long preempts_irq = preempts | RCUTORTURE_RDR_IRQ; 2244 unsigned long bhs = RCUTORTURE_RDR_BH | RCUTORTURE_RDR_RBH; 2245 2246 WARN_ON_ONCE(mask >> RCUTORTURE_RDR_SHIFT_1); // Can't have reader idx bits. 2247 /* Mostly only one bit (need preemption!), sometimes lots of bits. */ 2248 if (!(randmask1 & 0x7)) 2249 mask = mask & randmask2; 2250 else 2251 mask = mask & (1 << (randmask2 % RCUTORTURE_RDR_NBITS)); 2252 2253 // Can't have nested RCU reader without outer RCU reader. 2254 if (!(mask & RCUTORTURE_RDR_RCU_1) && (mask & RCUTORTURE_RDR_RCU_2)) { 2255 if (oldmask & RCUTORTURE_RDR_RCU_1) 2256 mask &= ~RCUTORTURE_RDR_RCU_2; 2257 else 2258 mask |= RCUTORTURE_RDR_RCU_1; 2259 } 2260 2261 /* 2262 * Can't enable bh w/irq disabled. 2263 */ 2264 if (mask & RCUTORTURE_RDR_IRQ) 2265 mask |= oldmask & bhs; 2266 2267 /* 2268 * Ideally these sequences would be detected in debug builds 2269 * (regardless of RT), but until then don't stop testing 2270 * them on non-RT. 2271 */ 2272 if (IS_ENABLED(CONFIG_PREEMPT_RT)) { 2273 /* Can't modify BH in atomic context */ 2274 if (oldmask & preempts_irq) 2275 mask &= ~bhs; 2276 if ((oldmask | mask) & preempts_irq) 2277 mask |= oldmask & bhs; 2278 } 2279 2280 return mask ?: RCUTORTURE_RDR_RCU_1; 2281 } 2282 2283 /* 2284 * Do a randomly selected number of extensions of an existing RCU read-side 2285 * critical section. 2286 */ 2287 static struct rt_read_seg * 2288 rcutorture_loop_extend(int *readstate, struct torture_random_state *trsp, struct rt_read_seg *rtrsp) 2289 { 2290 int i; 2291 int j; 2292 int mask = rcutorture_extend_mask_max(); 2293 2294 WARN_ON_ONCE(!*readstate); /* -Existing- RCU read-side critsect! */ 2295 if (!((mask - 1) & mask)) 2296 return rtrsp; /* Current RCU reader not extendable. */ 2297 /* Bias towards larger numbers of loops. */ 2298 i = torture_random(trsp); 2299 i = ((i | (i >> 3)) & RCUTORTURE_RDR_MAX_LOOPS) + 1; 2300 for (j = 0; j < i; j++) { 2301 mask = rcutorture_extend_mask(*readstate, trsp); 2302 WARN_ON_ONCE(mask & RCUTORTURE_RDR_UPDOWN); 2303 rcutorture_one_extend(readstate, mask, trsp, &rtrsp[j]); 2304 } 2305 return &rtrsp[j]; 2306 } 2307 2308 struct rcu_torture_one_read_state { 2309 bool checkpolling; 2310 unsigned long cookie; 2311 struct rcu_gp_oldstate cookie_full; 2312 unsigned long started; 2313 struct rcu_torture *p; 2314 int readstate; 2315 struct rt_read_seg rtseg[RCUTORTURE_RDR_MAX_SEGS]; 2316 struct rt_read_seg *rtrsp; 2317 unsigned long long ts; 2318 }; 2319 2320 static void init_rcu_torture_one_read_state(struct rcu_torture_one_read_state *rtorsp, 2321 struct torture_random_state *trsp) 2322 { 2323 memset(rtorsp, 0, sizeof(*rtorsp)); 2324 rtorsp->checkpolling = !(torture_random(trsp) & 0xfff); 2325 rtorsp->rtrsp = &rtorsp->rtseg[0]; 2326 } 2327 2328 /* 2329 * Set up the first segment of a series of overlapping read-side 2330 * critical sections. The caller must have actually initiated the 2331 * outermost read-side critical section. 2332 */ 2333 static bool rcu_torture_one_read_start(struct rcu_torture_one_read_state *rtorsp, 2334 struct torture_random_state *trsp, long myid) 2335 { 2336 if (rtorsp->checkpolling) { 2337 if (cur_ops->get_gp_state && cur_ops->poll_gp_state) 2338 rtorsp->cookie = cur_ops->get_gp_state(); 2339 if (cur_ops->get_gp_state_full && cur_ops->poll_gp_state_full) 2340 cur_ops->get_gp_state_full(&rtorsp->cookie_full); 2341 } 2342 rtorsp->started = cur_ops->get_gp_seq(); 2343 rtorsp->ts = rcu_trace_clock_local(); 2344 rtorsp->p = rcu_dereference_check(rcu_torture_current, 2345 !cur_ops->readlock_held || cur_ops->readlock_held() || 2346 (rtorsp->readstate & RCUTORTURE_RDR_UPDOWN)); 2347 if (rtorsp->p == NULL) { 2348 /* Wait for rcu_torture_writer to get underway */ 2349 rcutorture_one_extend(&rtorsp->readstate, 0, trsp, rtorsp->rtrsp); 2350 return false; 2351 } 2352 if (rtorsp->p->rtort_mbtest == 0) 2353 atomic_inc(&n_rcu_torture_mberror); 2354 rcu_torture_reader_do_mbchk(myid, rtorsp->p, trsp); 2355 return true; 2356 } 2357 2358 /* 2359 * Complete the last segment of a series of overlapping read-side 2360 * critical sections and check for errors. 2361 */ 2362 static void rcu_torture_one_read_end(struct rcu_torture_one_read_state *rtorsp, 2363 struct torture_random_state *trsp) 2364 { 2365 int i; 2366 unsigned long completed; 2367 int pipe_count; 2368 bool preempted = false; 2369 struct rt_read_seg *rtrsp1; 2370 2371 preempt_disable(); 2372 pipe_count = READ_ONCE(rtorsp->p->rtort_pipe_count); 2373 if (pipe_count > RCU_TORTURE_PIPE_LEN) { 2374 // Should not happen in a correct RCU implementation, 2375 // happens quite often for torture_type=busted. 2376 pipe_count = RCU_TORTURE_PIPE_LEN; 2377 } 2378 completed = cur_ops->get_gp_seq(); 2379 if (pipe_count > 1) { 2380 do_trace_rcu_torture_read(cur_ops->name, &rtorsp->p->rtort_rcu, 2381 rtorsp->ts, rtorsp->started, completed); 2382 rcu_ftrace_dump(DUMP_ALL); 2383 } 2384 __this_cpu_inc(rcu_torture_count[pipe_count]); 2385 completed = rcutorture_seq_diff(completed, rtorsp->started); 2386 if (completed > RCU_TORTURE_PIPE_LEN) { 2387 /* Should not happen, but... */ 2388 completed = RCU_TORTURE_PIPE_LEN; 2389 } 2390 __this_cpu_inc(rcu_torture_batch[completed]); 2391 preempt_enable(); 2392 if (rtorsp->checkpolling) { 2393 if (cur_ops->get_gp_state && cur_ops->poll_gp_state) 2394 WARN_ONCE(cur_ops->poll_gp_state(rtorsp->cookie), 2395 "%s: Cookie check 2 failed %s(%d) %lu->%lu\n", 2396 __func__, 2397 rcu_torture_writer_state_getname(), 2398 rcu_torture_writer_state, 2399 rtorsp->cookie, cur_ops->get_gp_state()); 2400 if (cur_ops->get_gp_state_full && cur_ops->poll_gp_state_full) 2401 WARN_ONCE(cur_ops->poll_gp_state_full(&rtorsp->cookie_full), 2402 "%s: Cookie check 6 failed %s(%d) online %*pbl\n", 2403 __func__, 2404 rcu_torture_writer_state_getname(), 2405 rcu_torture_writer_state, 2406 cpumask_pr_args(cpu_online_mask)); 2407 } 2408 if (cur_ops->reader_blocked) 2409 preempted = cur_ops->reader_blocked(); 2410 rcutorture_one_extend(&rtorsp->readstate, 0, trsp, rtorsp->rtrsp); 2411 WARN_ON_ONCE(rtorsp->readstate); 2412 // This next splat is expected behavior if leakpointer, especially 2413 // for CONFIG_RCU_STRICT_GRACE_PERIOD=y kernels. 2414 WARN_ON_ONCE(leakpointer && READ_ONCE(rtorsp->p->rtort_pipe_count) > 1); 2415 2416 /* If error or close call, record the sequence of reader protections. */ 2417 if ((pipe_count > 1 || completed > 1) && !xchg(&err_segs_recorded, 1)) { 2418 i = 0; 2419 for (rtrsp1 = &rtorsp->rtseg[0]; rtrsp1 < rtorsp->rtrsp; rtrsp1++) 2420 err_segs[i++] = *rtrsp1; 2421 rt_read_nsegs = i; 2422 rt_read_preempted = preempted; 2423 } 2424 } 2425 2426 /* 2427 * Do one read-side critical section, returning false if there was 2428 * no data to read. Can be invoked both from process context and 2429 * from a timer handler. 2430 */ 2431 static bool rcu_torture_one_read(struct torture_random_state *trsp, long myid) 2432 { 2433 int newstate; 2434 struct rcu_torture_one_read_state rtors; 2435 2436 WARN_ON_ONCE(!rcu_is_watching()); 2437 init_rcu_torture_one_read_state(&rtors, trsp); 2438 newstate = rcutorture_extend_mask(rtors.readstate, trsp); 2439 WARN_ON_ONCE(newstate & RCUTORTURE_RDR_UPDOWN); 2440 rcutorture_one_extend(&rtors.readstate, newstate, trsp, rtors.rtrsp++); 2441 if (!rcu_torture_one_read_start(&rtors, trsp, myid)) 2442 return false; 2443 rtors.rtrsp = rcutorture_loop_extend(&rtors.readstate, trsp, rtors.rtrsp); 2444 rcu_torture_one_read_end(&rtors, trsp); 2445 return true; 2446 } 2447 2448 static DEFINE_TORTURE_RANDOM_PERCPU(rcu_torture_timer_rand); 2449 2450 /* 2451 * RCU torture reader from timer handler. Dereferences rcu_torture_current, 2452 * incrementing the corresponding element of the pipeline array. The 2453 * counter in the element should never be greater than 1, otherwise, the 2454 * RCU implementation is broken. 2455 */ 2456 static void rcu_torture_timer(struct timer_list *unused) 2457 { 2458 atomic_long_inc(&n_rcu_torture_timers); 2459 (void)rcu_torture_one_read(this_cpu_ptr(&rcu_torture_timer_rand), -1); 2460 2461 /* Test call_rcu() invocation from interrupt handler. */ 2462 if (cur_ops->call) { 2463 struct rcu_head *rhp = kmalloc(sizeof(*rhp), GFP_NOWAIT); 2464 2465 if (rhp) 2466 cur_ops->call(rhp, rcu_torture_timer_cb); 2467 } 2468 } 2469 2470 /* 2471 * RCU torture reader kthread. Repeatedly dereferences rcu_torture_current, 2472 * incrementing the corresponding element of the pipeline array. The 2473 * counter in the element should never be greater than 1, otherwise, the 2474 * RCU implementation is broken. 2475 */ 2476 static int 2477 rcu_torture_reader(void *arg) 2478 { 2479 unsigned long lastsleep = jiffies; 2480 long myid = (long)arg; 2481 int mynumonline = myid; 2482 DEFINE_TORTURE_RANDOM(rand); 2483 struct timer_list t; 2484 2485 VERBOSE_TOROUT_STRING("rcu_torture_reader task started"); 2486 set_user_nice(current, MAX_NICE); 2487 if (irqreader && cur_ops->irq_capable) 2488 timer_setup_on_stack(&t, rcu_torture_timer, 0); 2489 tick_dep_set_task(current, TICK_DEP_BIT_RCU); // CPU bound, so need tick. 2490 do { 2491 if (irqreader && cur_ops->irq_capable) { 2492 if (!timer_pending(&t)) 2493 mod_timer(&t, jiffies + 1); 2494 } 2495 if (!rcu_torture_one_read(&rand, myid) && !torture_must_stop()) 2496 schedule_timeout_interruptible(HZ); 2497 if (time_after(jiffies, lastsleep) && !torture_must_stop()) { 2498 torture_hrtimeout_us(500, 1000, &rand); 2499 lastsleep = jiffies + 10; 2500 } 2501 while (!torture_must_stop() && 2502 (torture_num_online_cpus() < mynumonline || !rcu_inkernel_boot_has_ended())) 2503 schedule_timeout_interruptible(HZ / 5); 2504 stutter_wait("rcu_torture_reader"); 2505 } while (!torture_must_stop()); 2506 if (irqreader && cur_ops->irq_capable) { 2507 timer_delete_sync(&t); 2508 timer_destroy_on_stack(&t); 2509 } 2510 tick_dep_clear_task(current, TICK_DEP_BIT_RCU); 2511 torture_kthread_stopping("rcu_torture_reader"); 2512 return 0; 2513 } 2514 2515 struct rcu_torture_one_read_state_updown { 2516 struct hrtimer rtorsu_hrt; 2517 bool rtorsu_inuse; 2518 ktime_t rtorsu_kt; 2519 int rtorsu_cpu; 2520 unsigned long rtorsu_j; 2521 unsigned long rtorsu_ndowns; 2522 unsigned long rtorsu_nups; 2523 unsigned long rtorsu_nmigrates; 2524 struct torture_random_state rtorsu_trs; 2525 struct rcu_torture_one_read_state rtorsu_rtors; 2526 }; 2527 2528 static struct rcu_torture_one_read_state_updown *updownreaders; 2529 static DEFINE_TORTURE_RANDOM(rcu_torture_updown_rand); 2530 static int rcu_torture_updown(void *arg); 2531 2532 static enum hrtimer_restart rcu_torture_updown_hrt(struct hrtimer *hrtp) 2533 { 2534 int cpu = raw_smp_processor_id(); 2535 struct rcu_torture_one_read_state_updown *rtorsup; 2536 2537 rtorsup = container_of(hrtp, struct rcu_torture_one_read_state_updown, rtorsu_hrt); 2538 rcu_torture_one_read_end(&rtorsup->rtorsu_rtors, &rtorsup->rtorsu_trs); 2539 WARN_ONCE(rtorsup->rtorsu_nups >= rtorsup->rtorsu_ndowns, "%s: Up without matching down #%zu.\n", __func__, rtorsup - updownreaders); 2540 WRITE_ONCE(rtorsup->rtorsu_nups, rtorsup->rtorsu_nups + 1); 2541 WRITE_ONCE(rtorsup->rtorsu_nmigrates, 2542 rtorsup->rtorsu_nmigrates + (cpu != rtorsup->rtorsu_cpu)); 2543 smp_store_release(&rtorsup->rtorsu_inuse, false); 2544 return HRTIMER_NORESTART; 2545 } 2546 2547 static int rcu_torture_updown_init(void) 2548 { 2549 int i; 2550 struct torture_random_state *rand = &rcu_torture_updown_rand; 2551 int ret; 2552 2553 if (n_up_down < 0) 2554 return 0; 2555 if (!srcu_torture_have_up_down()) { 2556 VERBOSE_TOROUT_STRING("rcu_torture_updown_init: Disabling up/down reader tests due to lack of primitives"); 2557 return 0; 2558 } 2559 updownreaders = kcalloc(n_up_down, sizeof(*updownreaders), GFP_KERNEL); 2560 if (!updownreaders) { 2561 VERBOSE_TOROUT_STRING("rcu_torture_updown_init: Out of memory, disabling up/down reader tests"); 2562 return -ENOMEM; 2563 } 2564 for (i = 0; i < n_up_down; i++) { 2565 init_rcu_torture_one_read_state(&updownreaders[i].rtorsu_rtors, rand); 2566 hrtimer_setup(&updownreaders[i].rtorsu_hrt, rcu_torture_updown_hrt, CLOCK_MONOTONIC, 2567 HRTIMER_MODE_REL | HRTIMER_MODE_HARD); 2568 torture_random_init(&updownreaders[i].rtorsu_trs); 2569 init_rcu_torture_one_read_state(&updownreaders[i].rtorsu_rtors, 2570 &updownreaders[i].rtorsu_trs); 2571 } 2572 ret = torture_create_kthread(rcu_torture_updown, rand, updown_task); 2573 if (ret) { 2574 kfree(updownreaders); 2575 updownreaders = NULL; 2576 } 2577 return ret; 2578 } 2579 2580 static void rcu_torture_updown_cleanup(void) 2581 { 2582 struct rcu_torture_one_read_state_updown *rtorsup; 2583 2584 for (rtorsup = updownreaders; rtorsup < &updownreaders[n_up_down]; rtorsup++) { 2585 if (!smp_load_acquire(&rtorsup->rtorsu_inuse)) 2586 continue; 2587 if (hrtimer_cancel(&rtorsup->rtorsu_hrt) || WARN_ON_ONCE(rtorsup->rtorsu_inuse)) { 2588 rcu_torture_one_read_end(&rtorsup->rtorsu_rtors, &rtorsup->rtorsu_trs); 2589 WARN_ONCE(rtorsup->rtorsu_nups >= rtorsup->rtorsu_ndowns, "%s: Up without matching down #%zu.\n", __func__, rtorsup - updownreaders); 2590 WRITE_ONCE(rtorsup->rtorsu_nups, rtorsup->rtorsu_nups + 1); 2591 smp_store_release(&rtorsup->rtorsu_inuse, false); 2592 } 2593 2594 } 2595 kfree(updownreaders); 2596 updownreaders = NULL; 2597 } 2598 2599 // Do one reader for rcu_torture_updown(). 2600 static void rcu_torture_updown_one(struct rcu_torture_one_read_state_updown *rtorsup) 2601 { 2602 int idx; 2603 int rawidx; 2604 ktime_t t; 2605 2606 init_rcu_torture_one_read_state(&rtorsup->rtorsu_rtors, &rtorsup->rtorsu_trs); 2607 rawidx = cur_ops->down_read(); 2608 WRITE_ONCE(rtorsup->rtorsu_ndowns, rtorsup->rtorsu_ndowns + 1); 2609 idx = (rawidx << RCUTORTURE_RDR_SHIFT_1) & RCUTORTURE_RDR_MASK_1; 2610 rtorsup->rtorsu_rtors.readstate = idx | RCUTORTURE_RDR_UPDOWN; 2611 rtorsup->rtorsu_rtors.rtrsp++; 2612 rtorsup->rtorsu_cpu = raw_smp_processor_id(); 2613 if (!rcu_torture_one_read_start(&rtorsup->rtorsu_rtors, &rtorsup->rtorsu_trs, -1)) { 2614 WARN_ONCE(rtorsup->rtorsu_nups >= rtorsup->rtorsu_ndowns, "%s: Up without matching down #%zu.\n", __func__, rtorsup - updownreaders); 2615 WRITE_ONCE(rtorsup->rtorsu_nups, rtorsup->rtorsu_nups + 1); 2616 schedule_timeout_idle(HZ); 2617 return; 2618 } 2619 smp_store_release(&rtorsup->rtorsu_inuse, true); 2620 t = torture_random(&rtorsup->rtorsu_trs) & 0xfffff; // One per million. 2621 if (t < 10 * 1000) 2622 t = 200 * 1000 * 1000; 2623 hrtimer_start(&rtorsup->rtorsu_hrt, t, HRTIMER_MODE_REL | HRTIMER_MODE_HARD); 2624 smp_mb(); // Sample jiffies after posting hrtimer. 2625 rtorsup->rtorsu_j = jiffies; // Not used by hrtimer handler. 2626 rtorsup->rtorsu_kt = t; 2627 } 2628 2629 /* 2630 * RCU torture up/down reader kthread, starting RCU readers in kthread 2631 * context and ending them in hrtimer handlers. Otherwise similar to 2632 * rcu_torture_reader(). 2633 */ 2634 static int 2635 rcu_torture_updown(void *arg) 2636 { 2637 unsigned long j; 2638 struct rcu_torture_one_read_state_updown *rtorsup; 2639 2640 VERBOSE_TOROUT_STRING("rcu_torture_updown task started"); 2641 do { 2642 for (rtorsup = updownreaders; rtorsup < &updownreaders[n_up_down]; rtorsup++) { 2643 if (torture_must_stop()) 2644 break; 2645 j = smp_load_acquire(&jiffies); // Time before ->rtorsu_inuse. 2646 if (smp_load_acquire(&rtorsup->rtorsu_inuse)) { 2647 WARN_ONCE(time_after(j, rtorsup->rtorsu_j + 1 + HZ * 10), 2648 "hrtimer queued at jiffies %lu for %lld ns took %lu jiffies\n", rtorsup->rtorsu_j, rtorsup->rtorsu_kt, j - rtorsup->rtorsu_j); 2649 continue; 2650 } 2651 rcu_torture_updown_one(rtorsup); 2652 } 2653 torture_hrtimeout_ms(1, 1000, &rcu_torture_updown_rand); 2654 stutter_wait("rcu_torture_updown"); 2655 } while (!torture_must_stop()); 2656 rcu_torture_updown_cleanup(); 2657 torture_kthread_stopping("rcu_torture_updown"); 2658 return 0; 2659 } 2660 2661 /* 2662 * Randomly Toggle CPUs' callback-offload state. This uses hrtimers to 2663 * increase race probabilities and fuzzes the interval between toggling. 2664 */ 2665 static int rcu_nocb_toggle(void *arg) 2666 { 2667 int cpu; 2668 int maxcpu = -1; 2669 int oldnice = task_nice(current); 2670 long r; 2671 DEFINE_TORTURE_RANDOM(rand); 2672 ktime_t toggle_delay; 2673 unsigned long toggle_fuzz; 2674 ktime_t toggle_interval = ms_to_ktime(nocbs_toggle); 2675 2676 VERBOSE_TOROUT_STRING("rcu_nocb_toggle task started"); 2677 while (!rcu_inkernel_boot_has_ended()) 2678 schedule_timeout_interruptible(HZ / 10); 2679 for_each_possible_cpu(cpu) 2680 maxcpu = cpu; 2681 WARN_ON(maxcpu < 0); 2682 if (toggle_interval > ULONG_MAX) 2683 toggle_fuzz = ULONG_MAX >> 3; 2684 else 2685 toggle_fuzz = toggle_interval >> 3; 2686 if (toggle_fuzz <= 0) 2687 toggle_fuzz = NSEC_PER_USEC; 2688 do { 2689 r = torture_random(&rand); 2690 cpu = (r >> 1) % (maxcpu + 1); 2691 if (r & 0x1) { 2692 rcu_nocb_cpu_offload(cpu); 2693 atomic_long_inc(&n_nocb_offload); 2694 } else { 2695 rcu_nocb_cpu_deoffload(cpu); 2696 atomic_long_inc(&n_nocb_deoffload); 2697 } 2698 toggle_delay = torture_random(&rand) % toggle_fuzz + toggle_interval; 2699 set_current_state(TASK_INTERRUPTIBLE); 2700 schedule_hrtimeout(&toggle_delay, HRTIMER_MODE_REL); 2701 if (stutter_wait("rcu_nocb_toggle")) 2702 sched_set_normal(current, oldnice); 2703 } while (!torture_must_stop()); 2704 torture_kthread_stopping("rcu_nocb_toggle"); 2705 return 0; 2706 } 2707 2708 /* 2709 * Print torture statistics. Caller must ensure that there is only 2710 * one call to this function at a given time!!! This is normally 2711 * accomplished by relying on the module system to only have one copy 2712 * of the module loaded, and then by giving the rcu_torture_stats 2713 * kthread full control (or the init/cleanup functions when rcu_torture_stats 2714 * thread is not running). 2715 */ 2716 static void 2717 rcu_torture_stats_print(void) 2718 { 2719 int cpu; 2720 int i; 2721 long pipesummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 }; 2722 long batchsummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 }; 2723 long n_gpwraps = 0; 2724 unsigned long ndowns = 0; 2725 unsigned long nunexpired = 0; 2726 unsigned long nmigrates = 0; 2727 unsigned long nups = 0; 2728 struct rcu_torture *rtcp; 2729 static unsigned long rtcv_snap = ULONG_MAX; 2730 static bool splatted; 2731 struct task_struct *wtp; 2732 2733 for_each_possible_cpu(cpu) { 2734 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) { 2735 pipesummary[i] += READ_ONCE(per_cpu(rcu_torture_count, cpu)[i]); 2736 batchsummary[i] += READ_ONCE(per_cpu(rcu_torture_batch, cpu)[i]); 2737 } 2738 if (cur_ops->get_gpwrap_count) 2739 n_gpwraps += cur_ops->get_gpwrap_count(cpu); 2740 } 2741 if (updownreaders) { 2742 for (i = 0; i < n_up_down; i++) { 2743 ndowns += READ_ONCE(updownreaders[i].rtorsu_ndowns); 2744 nups += READ_ONCE(updownreaders[i].rtorsu_nups); 2745 nunexpired += READ_ONCE(updownreaders[i].rtorsu_inuse); 2746 nmigrates += READ_ONCE(updownreaders[i].rtorsu_nmigrates); 2747 } 2748 } 2749 for (i = RCU_TORTURE_PIPE_LEN; i >= 0; i--) { 2750 if (pipesummary[i] != 0) 2751 break; 2752 } // The value of variable "i" is used later, so don't clobber it! 2753 2754 pr_alert("%s%s ", torture_type, TORTURE_FLAG); 2755 rtcp = rcu_access_pointer(rcu_torture_current); 2756 pr_cont("rtc: %p %s: %lu tfle: %d rta: %d rtaf: %d rtf: %d ", 2757 rtcp, 2758 rtcp && !rcu_stall_is_suppressed_at_boot() ? "ver" : "VER", 2759 rcu_torture_current_version, 2760 list_empty(&rcu_torture_freelist), 2761 atomic_read(&n_rcu_torture_alloc), 2762 atomic_read(&n_rcu_torture_alloc_fail), 2763 atomic_read(&n_rcu_torture_free)); 2764 pr_cont("rtmbe: %d rtmbkf: %d/%d rtbe: %ld rtbke: %ld ", 2765 atomic_read(&n_rcu_torture_mberror), 2766 atomic_read(&n_rcu_torture_mbchk_fail), atomic_read(&n_rcu_torture_mbchk_tries), 2767 n_rcu_torture_barrier_error, 2768 n_rcu_torture_boost_ktrerror); 2769 pr_cont("rtbf: %ld rtb: %ld nt: %ld ", 2770 n_rcu_torture_boost_failure, 2771 n_rcu_torture_boosts, 2772 atomic_long_read(&n_rcu_torture_timers)); 2773 if (updownreaders) 2774 pr_cont("ndowns: %lu nups: %lu nhrt: %lu nmigrates: %lu ", ndowns, nups, nunexpired, nmigrates); 2775 torture_onoff_stats(); 2776 pr_cont("barrier: %ld/%ld:%ld ", 2777 data_race(n_barrier_successes), 2778 data_race(n_barrier_attempts), 2779 data_race(n_rcu_torture_barrier_error)); 2780 pr_cont("read-exits: %ld ", data_race(n_read_exits)); // Statistic. 2781 pr_cont("nocb-toggles: %ld:%ld ", 2782 atomic_long_read(&n_nocb_offload), atomic_long_read(&n_nocb_deoffload)); 2783 pr_cont("gpwraps: %ld\n", n_gpwraps); 2784 2785 pr_alert("%s%s ", torture_type, TORTURE_FLAG); 2786 if (atomic_read(&n_rcu_torture_mberror) || 2787 atomic_read(&n_rcu_torture_mbchk_fail) || 2788 n_rcu_torture_barrier_error || n_rcu_torture_boost_ktrerror || 2789 n_rcu_torture_boost_failure || i > 1) { 2790 pr_cont("%s", "!!! "); 2791 atomic_inc(&n_rcu_torture_error); 2792 WARN_ON_ONCE(atomic_read(&n_rcu_torture_mberror)); 2793 WARN_ON_ONCE(atomic_read(&n_rcu_torture_mbchk_fail)); 2794 WARN_ON_ONCE(n_rcu_torture_barrier_error); // rcu_barrier() 2795 WARN_ON_ONCE(n_rcu_torture_boost_ktrerror); // no boost kthread 2796 WARN_ON_ONCE(n_rcu_torture_boost_failure); // boost failed (TIMER_SOFTIRQ RT prio?) 2797 WARN_ON_ONCE(i > 1); // Too-short grace period 2798 } 2799 pr_cont("Reader Pipe: "); 2800 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) 2801 pr_cont(" %ld", pipesummary[i]); 2802 pr_cont("\n"); 2803 2804 pr_alert("%s%s ", torture_type, TORTURE_FLAG); 2805 pr_cont("Reader Batch: "); 2806 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) 2807 pr_cont(" %ld", batchsummary[i]); 2808 pr_cont("\n"); 2809 2810 pr_alert("%s%s ", torture_type, TORTURE_FLAG); 2811 pr_cont("Free-Block Circulation: "); 2812 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) { 2813 pr_cont(" %d", atomic_read(&rcu_torture_wcount[i])); 2814 } 2815 pr_cont("\n"); 2816 2817 if (cur_ops->stats) 2818 cur_ops->stats(); 2819 if (rtcv_snap == rcu_torture_current_version && 2820 rcu_access_pointer(rcu_torture_current) && 2821 !rcu_stall_is_suppressed() && 2822 rcu_inkernel_boot_has_ended()) { 2823 int __maybe_unused flags = 0; 2824 unsigned long __maybe_unused gp_seq = 0; 2825 2826 if (cur_ops->get_gp_data) 2827 cur_ops->get_gp_data(&flags, &gp_seq); 2828 wtp = READ_ONCE(writer_task); 2829 pr_alert("??? Writer stall state %s(%d) g%lu f%#x ->state %#x cpu %d\n", 2830 rcu_torture_writer_state_getname(), 2831 rcu_torture_writer_state, gp_seq, flags, 2832 wtp == NULL ? ~0U : wtp->__state, 2833 wtp == NULL ? -1 : (int)task_cpu(wtp)); 2834 if (!splatted && wtp) { 2835 sched_show_task(wtp); 2836 splatted = true; 2837 } 2838 if (cur_ops->gp_kthread_dbg) 2839 cur_ops->gp_kthread_dbg(); 2840 rcu_ftrace_dump(DUMP_ALL); 2841 } 2842 rtcv_snap = rcu_torture_current_version; 2843 } 2844 2845 /* 2846 * Periodically prints torture statistics, if periodic statistics printing 2847 * was specified via the stat_interval module parameter. 2848 */ 2849 static int 2850 rcu_torture_stats(void *arg) 2851 { 2852 VERBOSE_TOROUT_STRING("rcu_torture_stats task started"); 2853 do { 2854 schedule_timeout_interruptible(stat_interval * HZ); 2855 rcu_torture_stats_print(); 2856 torture_shutdown_absorb("rcu_torture_stats"); 2857 } while (!torture_must_stop()); 2858 torture_kthread_stopping("rcu_torture_stats"); 2859 return 0; 2860 } 2861 2862 /* Test mem_dump_obj() and friends. */ 2863 static void rcu_torture_mem_dump_obj(void) 2864 { 2865 struct rcu_head *rhp; 2866 struct kmem_cache *kcp; 2867 static int z; 2868 2869 kcp = kmem_cache_create("rcuscale", 136, 8, SLAB_STORE_USER, NULL); 2870 if (WARN_ON_ONCE(!kcp)) 2871 return; 2872 rhp = kmem_cache_alloc(kcp, GFP_KERNEL); 2873 if (WARN_ON_ONCE(!rhp)) { 2874 kmem_cache_destroy(kcp); 2875 return; 2876 } 2877 pr_alert("mem_dump_obj() slab test: rcu_torture_stats = %px, &rhp = %px, rhp = %px, &z = %px\n", stats_task, &rhp, rhp, &z); 2878 pr_alert("mem_dump_obj(ZERO_SIZE_PTR):"); 2879 mem_dump_obj(ZERO_SIZE_PTR); 2880 pr_alert("mem_dump_obj(NULL):"); 2881 mem_dump_obj(NULL); 2882 pr_alert("mem_dump_obj(%px):", &rhp); 2883 mem_dump_obj(&rhp); 2884 pr_alert("mem_dump_obj(%px):", rhp); 2885 mem_dump_obj(rhp); 2886 pr_alert("mem_dump_obj(%px):", &rhp->func); 2887 mem_dump_obj(&rhp->func); 2888 pr_alert("mem_dump_obj(%px):", &z); 2889 mem_dump_obj(&z); 2890 kmem_cache_free(kcp, rhp); 2891 kmem_cache_destroy(kcp); 2892 rhp = kmalloc(sizeof(*rhp), GFP_KERNEL); 2893 if (WARN_ON_ONCE(!rhp)) 2894 return; 2895 pr_alert("mem_dump_obj() kmalloc test: rcu_torture_stats = %px, &rhp = %px, rhp = %px\n", stats_task, &rhp, rhp); 2896 pr_alert("mem_dump_obj(kmalloc %px):", rhp); 2897 mem_dump_obj(rhp); 2898 pr_alert("mem_dump_obj(kmalloc %px):", &rhp->func); 2899 mem_dump_obj(&rhp->func); 2900 kfree(rhp); 2901 rhp = vmalloc(4096); 2902 if (WARN_ON_ONCE(!rhp)) 2903 return; 2904 pr_alert("mem_dump_obj() vmalloc test: rcu_torture_stats = %px, &rhp = %px, rhp = %px\n", stats_task, &rhp, rhp); 2905 pr_alert("mem_dump_obj(vmalloc %px):", rhp); 2906 mem_dump_obj(rhp); 2907 pr_alert("mem_dump_obj(vmalloc %px):", &rhp->func); 2908 mem_dump_obj(&rhp->func); 2909 vfree(rhp); 2910 } 2911 2912 static void 2913 rcu_torture_print_module_parms(struct rcu_torture_ops *cur_ops, const char *tag) 2914 { 2915 pr_alert("%s" TORTURE_FLAG 2916 "--- %s: nreaders=%d nfakewriters=%d " 2917 "stat_interval=%d verbose=%d test_no_idle_hz=%d " 2918 "shuffle_interval=%d stutter=%d irqreader=%d " 2919 "fqs_duration=%d fqs_holdoff=%d fqs_stutter=%d " 2920 "test_boost=%d/%d test_boost_interval=%d " 2921 "test_boost_duration=%d test_boost_holdoff=%d shutdown_secs=%d " 2922 "stall_cpu=%d stall_cpu_holdoff=%d stall_cpu_irqsoff=%d " 2923 "stall_cpu_block=%d stall_cpu_repeat=%d " 2924 "n_barrier_cbs=%d " 2925 "onoff_interval=%d onoff_holdoff=%d " 2926 "read_exit_delay=%d read_exit_burst=%d " 2927 "reader_flavor=%x " 2928 "nocbs_nthreads=%d nocbs_toggle=%d " 2929 "test_nmis=%d " 2930 "preempt_duration=%d preempt_interval=%d n_up_down=%d\n", 2931 torture_type, tag, nrealreaders, nrealfakewriters, 2932 stat_interval, verbose, test_no_idle_hz, shuffle_interval, 2933 stutter, irqreader, fqs_duration, fqs_holdoff, fqs_stutter, 2934 test_boost, cur_ops->can_boost, 2935 test_boost_interval, test_boost_duration, test_boost_holdoff, shutdown_secs, 2936 stall_cpu, stall_cpu_holdoff, stall_cpu_irqsoff, 2937 stall_cpu_block, stall_cpu_repeat, 2938 n_barrier_cbs, 2939 onoff_interval, onoff_holdoff, 2940 read_exit_delay, read_exit_burst, 2941 reader_flavor, 2942 nocbs_nthreads, nocbs_toggle, 2943 test_nmis, 2944 preempt_duration, preempt_interval, n_up_down); 2945 } 2946 2947 static int rcutorture_booster_cleanup(unsigned int cpu) 2948 { 2949 struct task_struct *t; 2950 2951 if (boost_tasks[cpu] == NULL) 2952 return 0; 2953 mutex_lock(&boost_mutex); 2954 t = boost_tasks[cpu]; 2955 boost_tasks[cpu] = NULL; 2956 rcu_torture_enable_rt_throttle(); 2957 mutex_unlock(&boost_mutex); 2958 2959 /* This must be outside of the mutex, otherwise deadlock! */ 2960 torture_stop_kthread(rcu_torture_boost, t); 2961 return 0; 2962 } 2963 2964 static int rcutorture_booster_init(unsigned int cpu) 2965 { 2966 int retval; 2967 2968 if (boost_tasks[cpu] != NULL) 2969 return 0; /* Already created, nothing more to do. */ 2970 2971 // Testing RCU priority boosting requires rcutorture do 2972 // some serious abuse. Counter this by running ksoftirqd 2973 // at higher priority. 2974 if (IS_BUILTIN(CONFIG_RCU_TORTURE_TEST)) { 2975 struct sched_param sp; 2976 struct task_struct *t; 2977 2978 t = per_cpu(ksoftirqd, cpu); 2979 WARN_ON_ONCE(!t); 2980 sp.sched_priority = 2; 2981 sched_setscheduler_nocheck(t, SCHED_FIFO, &sp); 2982 #ifdef CONFIG_IRQ_FORCED_THREADING 2983 if (force_irqthreads()) { 2984 t = per_cpu(ktimerd, cpu); 2985 WARN_ON_ONCE(!t); 2986 sp.sched_priority = 2; 2987 sched_setscheduler_nocheck(t, SCHED_FIFO, &sp); 2988 } 2989 #endif 2990 } 2991 2992 /* Don't allow time recalculation while creating a new task. */ 2993 mutex_lock(&boost_mutex); 2994 rcu_torture_disable_rt_throttle(); 2995 VERBOSE_TOROUT_STRING("Creating rcu_torture_boost task"); 2996 boost_tasks[cpu] = kthread_run_on_cpu(rcu_torture_boost, NULL, 2997 cpu, "rcu_torture_boost_%u"); 2998 if (IS_ERR(boost_tasks[cpu])) { 2999 retval = PTR_ERR(boost_tasks[cpu]); 3000 VERBOSE_TOROUT_STRING("rcu_torture_boost task create failed"); 3001 n_rcu_torture_boost_ktrerror++; 3002 boost_tasks[cpu] = NULL; 3003 mutex_unlock(&boost_mutex); 3004 return retval; 3005 } 3006 mutex_unlock(&boost_mutex); 3007 return 0; 3008 } 3009 3010 static int rcu_torture_stall_nf(struct notifier_block *nb, unsigned long v, void *ptr) 3011 { 3012 pr_info("%s: v=%lu, duration=%lu.\n", __func__, v, (unsigned long)ptr); 3013 return NOTIFY_OK; 3014 } 3015 3016 static struct notifier_block rcu_torture_stall_block = { 3017 .notifier_call = rcu_torture_stall_nf, 3018 }; 3019 3020 /* 3021 * CPU-stall kthread. It waits as specified by stall_cpu_holdoff, then 3022 * induces a CPU stall for the time specified by stall_cpu. If a new 3023 * stall test is added, stallsdone in rcu_torture_writer() must be adjusted. 3024 */ 3025 static void rcu_torture_stall_one(int rep, int irqsoff) 3026 { 3027 int idx; 3028 unsigned long stop_at; 3029 3030 if (stall_cpu_holdoff > 0) { 3031 VERBOSE_TOROUT_STRING("rcu_torture_stall begin holdoff"); 3032 schedule_timeout_interruptible(stall_cpu_holdoff * HZ); 3033 VERBOSE_TOROUT_STRING("rcu_torture_stall end holdoff"); 3034 } 3035 if (!kthread_should_stop() && stall_gp_kthread > 0) { 3036 VERBOSE_TOROUT_STRING("rcu_torture_stall begin GP stall"); 3037 rcu_gp_set_torture_wait(stall_gp_kthread * HZ); 3038 for (idx = 0; idx < stall_gp_kthread + 2; idx++) { 3039 if (kthread_should_stop()) 3040 break; 3041 schedule_timeout_uninterruptible(HZ); 3042 } 3043 } 3044 if (!kthread_should_stop() && stall_cpu > 0) { 3045 VERBOSE_TOROUT_STRING("rcu_torture_stall begin CPU stall"); 3046 stop_at = ktime_get_seconds() + stall_cpu; 3047 /* RCU CPU stall is expected behavior in following code. */ 3048 idx = cur_ops->readlock(); 3049 if (irqsoff) 3050 local_irq_disable(); 3051 else if (!stall_cpu_block) 3052 preempt_disable(); 3053 pr_alert("%s start stall episode %d on CPU %d.\n", 3054 __func__, rep + 1, raw_smp_processor_id()); 3055 while (ULONG_CMP_LT((unsigned long)ktime_get_seconds(), stop_at) && 3056 !kthread_should_stop()) 3057 if (stall_cpu_block) { 3058 #ifdef CONFIG_PREEMPTION 3059 preempt_schedule(); 3060 #else 3061 schedule_timeout_uninterruptible(HZ); 3062 #endif 3063 } else if (stall_no_softlockup) { 3064 touch_softlockup_watchdog(); 3065 } 3066 if (irqsoff) 3067 local_irq_enable(); 3068 else if (!stall_cpu_block) 3069 preempt_enable(); 3070 cur_ops->readunlock(idx); 3071 } 3072 } 3073 3074 /* 3075 * CPU-stall kthread. Invokes rcu_torture_stall_one() once, and then as many 3076 * additional times as specified by the stall_cpu_repeat module parameter. 3077 * Note that stall_cpu_irqsoff is ignored on the second and subsequent 3078 * stall. 3079 */ 3080 static int rcu_torture_stall(void *args) 3081 { 3082 int i; 3083 int repeat = stall_cpu_repeat; 3084 int ret; 3085 3086 VERBOSE_TOROUT_STRING("rcu_torture_stall task started"); 3087 if (repeat < 0) { 3088 repeat = 0; 3089 WARN_ON_ONCE(IS_BUILTIN(CONFIG_RCU_TORTURE_TEST)); 3090 } 3091 if (rcu_cpu_stall_notifiers) { 3092 ret = rcu_stall_chain_notifier_register(&rcu_torture_stall_block); 3093 if (ret) 3094 pr_info("%s: rcu_stall_chain_notifier_register() returned %d, %sexpected.\n", 3095 __func__, ret, !IS_ENABLED(CONFIG_RCU_STALL_COMMON) ? "un" : ""); 3096 } 3097 for (i = 0; i <= repeat; i++) { 3098 if (kthread_should_stop()) 3099 break; 3100 rcu_torture_stall_one(i, i == 0 ? stall_cpu_irqsoff : 0); 3101 } 3102 pr_alert("%s end.\n", __func__); 3103 if (rcu_cpu_stall_notifiers && !ret) { 3104 ret = rcu_stall_chain_notifier_unregister(&rcu_torture_stall_block); 3105 if (ret) 3106 pr_info("%s: rcu_stall_chain_notifier_unregister() returned %d.\n", __func__, ret); 3107 } 3108 torture_shutdown_absorb("rcu_torture_stall"); 3109 while (!kthread_should_stop()) 3110 schedule_timeout_interruptible(10 * HZ); 3111 return 0; 3112 } 3113 3114 /* Spawn CPU-stall kthread, if stall_cpu specified. */ 3115 static int __init rcu_torture_stall_init(void) 3116 { 3117 if (stall_cpu <= 0 && stall_gp_kthread <= 0) 3118 return 0; 3119 return torture_create_kthread(rcu_torture_stall, NULL, stall_task); 3120 } 3121 3122 /* State structure for forward-progress self-propagating RCU callback. */ 3123 struct fwd_cb_state { 3124 struct rcu_head rh; 3125 int stop; 3126 }; 3127 3128 /* 3129 * Forward-progress self-propagating RCU callback function. Because 3130 * callbacks run from softirq, this function is an implicit RCU read-side 3131 * critical section. 3132 */ 3133 static void rcu_torture_fwd_prog_cb(struct rcu_head *rhp) 3134 { 3135 struct fwd_cb_state *fcsp = container_of(rhp, struct fwd_cb_state, rh); 3136 3137 if (READ_ONCE(fcsp->stop)) { 3138 WRITE_ONCE(fcsp->stop, 2); 3139 return; 3140 } 3141 cur_ops->call(&fcsp->rh, rcu_torture_fwd_prog_cb); 3142 } 3143 3144 /* State for continuous-flood RCU callbacks. */ 3145 struct rcu_fwd_cb { 3146 struct rcu_head rh; 3147 struct rcu_fwd_cb *rfc_next; 3148 struct rcu_fwd *rfc_rfp; 3149 int rfc_gps; 3150 }; 3151 3152 #define MAX_FWD_CB_JIFFIES (8 * HZ) /* Maximum CB test duration. */ 3153 #define MIN_FWD_CB_LAUNDERS 3 /* This many CB invocations to count. */ 3154 #define MIN_FWD_CBS_LAUNDERED 100 /* Number of counted CBs. */ 3155 #define FWD_CBS_HIST_DIV 10 /* Histogram buckets/second. */ 3156 #define N_LAUNDERS_HIST (2 * MAX_FWD_CB_JIFFIES / (HZ / FWD_CBS_HIST_DIV)) 3157 3158 struct rcu_launder_hist { 3159 long n_launders; 3160 unsigned long launder_gp_seq; 3161 }; 3162 3163 struct rcu_fwd { 3164 spinlock_t rcu_fwd_lock; 3165 struct rcu_fwd_cb *rcu_fwd_cb_head; 3166 struct rcu_fwd_cb **rcu_fwd_cb_tail; 3167 long n_launders_cb; 3168 unsigned long rcu_fwd_startat; 3169 struct rcu_launder_hist n_launders_hist[N_LAUNDERS_HIST]; 3170 unsigned long rcu_launder_gp_seq_start; 3171 int rcu_fwd_id; 3172 }; 3173 3174 static DEFINE_MUTEX(rcu_fwd_mutex); 3175 static struct rcu_fwd *rcu_fwds; 3176 static unsigned long rcu_fwd_seq; 3177 static atomic_long_t rcu_fwd_max_cbs; 3178 static bool rcu_fwd_emergency_stop; 3179 3180 static void rcu_torture_fwd_cb_hist(struct rcu_fwd *rfp) 3181 { 3182 unsigned long gps; 3183 unsigned long gps_old; 3184 int i; 3185 int j; 3186 3187 for (i = ARRAY_SIZE(rfp->n_launders_hist) - 1; i > 0; i--) 3188 if (rfp->n_launders_hist[i].n_launders > 0) 3189 break; 3190 pr_alert("%s: Callback-invocation histogram %d (duration %lu jiffies):", 3191 __func__, rfp->rcu_fwd_id, jiffies - rfp->rcu_fwd_startat); 3192 gps_old = rfp->rcu_launder_gp_seq_start; 3193 for (j = 0; j <= i; j++) { 3194 gps = rfp->n_launders_hist[j].launder_gp_seq; 3195 pr_cont(" %ds/%d: %ld:%ld", 3196 j + 1, FWD_CBS_HIST_DIV, 3197 rfp->n_launders_hist[j].n_launders, 3198 rcutorture_seq_diff(gps, gps_old)); 3199 gps_old = gps; 3200 } 3201 pr_cont("\n"); 3202 } 3203 3204 /* Callback function for continuous-flood RCU callbacks. */ 3205 static void rcu_torture_fwd_cb_cr(struct rcu_head *rhp) 3206 { 3207 unsigned long flags; 3208 int i; 3209 struct rcu_fwd_cb *rfcp = container_of(rhp, struct rcu_fwd_cb, rh); 3210 struct rcu_fwd_cb **rfcpp; 3211 struct rcu_fwd *rfp = rfcp->rfc_rfp; 3212 3213 rfcp->rfc_next = NULL; 3214 rfcp->rfc_gps++; 3215 spin_lock_irqsave(&rfp->rcu_fwd_lock, flags); 3216 rfcpp = rfp->rcu_fwd_cb_tail; 3217 rfp->rcu_fwd_cb_tail = &rfcp->rfc_next; 3218 smp_store_release(rfcpp, rfcp); 3219 WRITE_ONCE(rfp->n_launders_cb, rfp->n_launders_cb + 1); 3220 i = ((jiffies - rfp->rcu_fwd_startat) / (HZ / FWD_CBS_HIST_DIV)); 3221 if (i >= ARRAY_SIZE(rfp->n_launders_hist)) 3222 i = ARRAY_SIZE(rfp->n_launders_hist) - 1; 3223 rfp->n_launders_hist[i].n_launders++; 3224 rfp->n_launders_hist[i].launder_gp_seq = cur_ops->get_gp_seq(); 3225 spin_unlock_irqrestore(&rfp->rcu_fwd_lock, flags); 3226 } 3227 3228 // Give the scheduler a chance, even on nohz_full CPUs. 3229 static void rcu_torture_fwd_prog_cond_resched(unsigned long iter) 3230 { 3231 if (IS_ENABLED(CONFIG_PREEMPTION) && IS_ENABLED(CONFIG_NO_HZ_FULL)) { 3232 // Real call_rcu() floods hit userspace, so emulate that. 3233 if (need_resched() || (iter & 0xfff)) 3234 schedule(); 3235 return; 3236 } 3237 // No userspace emulation: CB invocation throttles call_rcu() 3238 cond_resched(); 3239 } 3240 3241 /* 3242 * Free all callbacks on the rcu_fwd_cb_head list, either because the 3243 * test is over or because we hit an OOM event. 3244 */ 3245 static unsigned long rcu_torture_fwd_prog_cbfree(struct rcu_fwd *rfp) 3246 { 3247 unsigned long flags; 3248 unsigned long freed = 0; 3249 struct rcu_fwd_cb *rfcp; 3250 3251 for (;;) { 3252 spin_lock_irqsave(&rfp->rcu_fwd_lock, flags); 3253 rfcp = rfp->rcu_fwd_cb_head; 3254 if (!rfcp) { 3255 spin_unlock_irqrestore(&rfp->rcu_fwd_lock, flags); 3256 break; 3257 } 3258 rfp->rcu_fwd_cb_head = rfcp->rfc_next; 3259 if (!rfp->rcu_fwd_cb_head) 3260 rfp->rcu_fwd_cb_tail = &rfp->rcu_fwd_cb_head; 3261 spin_unlock_irqrestore(&rfp->rcu_fwd_lock, flags); 3262 kfree(rfcp); 3263 freed++; 3264 rcu_torture_fwd_prog_cond_resched(freed); 3265 if (tick_nohz_full_enabled()) { 3266 local_irq_save(flags); 3267 rcu_momentary_eqs(); 3268 local_irq_restore(flags); 3269 } 3270 } 3271 return freed; 3272 } 3273 3274 /* Carry out need_resched()/cond_resched() forward-progress testing. */ 3275 static void rcu_torture_fwd_prog_nr(struct rcu_fwd *rfp, 3276 int *tested, int *tested_tries) 3277 { 3278 unsigned long cver; 3279 unsigned long dur; 3280 struct fwd_cb_state fcs; 3281 unsigned long gps; 3282 int idx; 3283 int sd; 3284 int sd4; 3285 bool selfpropcb = false; 3286 unsigned long stopat; 3287 static DEFINE_TORTURE_RANDOM(trs); 3288 3289 pr_alert("%s: Starting forward-progress test %d\n", __func__, rfp->rcu_fwd_id); 3290 if (!cur_ops->sync) 3291 return; // Cannot do need_resched() forward progress testing without ->sync. 3292 if (cur_ops->call && cur_ops->cb_barrier) { 3293 init_rcu_head_on_stack(&fcs.rh); 3294 selfpropcb = true; 3295 } 3296 3297 /* Tight loop containing cond_resched(). */ 3298 atomic_inc(&rcu_fwd_cb_nodelay); 3299 cur_ops->sync(); /* Later readers see above write. */ 3300 if (selfpropcb) { 3301 WRITE_ONCE(fcs.stop, 0); 3302 cur_ops->call(&fcs.rh, rcu_torture_fwd_prog_cb); 3303 } 3304 cver = READ_ONCE(rcu_torture_current_version); 3305 gps = cur_ops->get_gp_seq(); 3306 sd = cur_ops->stall_dur() + 1; 3307 sd4 = (sd + fwd_progress_div - 1) / fwd_progress_div; 3308 dur = sd4 + torture_random(&trs) % (sd - sd4); 3309 WRITE_ONCE(rfp->rcu_fwd_startat, jiffies); 3310 stopat = rfp->rcu_fwd_startat + dur; 3311 while (time_before(jiffies, stopat) && 3312 !shutdown_time_arrived() && 3313 !READ_ONCE(rcu_fwd_emergency_stop) && !torture_must_stop()) { 3314 idx = cur_ops->readlock(); 3315 udelay(10); 3316 cur_ops->readunlock(idx); 3317 if (!fwd_progress_need_resched || need_resched()) 3318 cond_resched(); 3319 } 3320 (*tested_tries)++; 3321 if (!time_before(jiffies, stopat) && 3322 !shutdown_time_arrived() && 3323 !READ_ONCE(rcu_fwd_emergency_stop) && !torture_must_stop()) { 3324 (*tested)++; 3325 cver = READ_ONCE(rcu_torture_current_version) - cver; 3326 gps = rcutorture_seq_diff(cur_ops->get_gp_seq(), gps); 3327 WARN_ON(!cver && gps < 2); 3328 pr_alert("%s: %d Duration %ld cver %ld gps %ld\n", __func__, 3329 rfp->rcu_fwd_id, dur, cver, gps); 3330 } 3331 if (selfpropcb) { 3332 WRITE_ONCE(fcs.stop, 1); 3333 cur_ops->sync(); /* Wait for running CB to complete. */ 3334 pr_alert("%s: Waiting for CBs: %pS() %d\n", __func__, cur_ops->cb_barrier, rfp->rcu_fwd_id); 3335 cur_ops->cb_barrier(); /* Wait for queued callbacks. */ 3336 } 3337 3338 if (selfpropcb) { 3339 WARN_ON(READ_ONCE(fcs.stop) != 2); 3340 destroy_rcu_head_on_stack(&fcs.rh); 3341 } 3342 schedule_timeout_uninterruptible(HZ / 10); /* Let kthreads recover. */ 3343 atomic_dec(&rcu_fwd_cb_nodelay); 3344 } 3345 3346 /* Carry out call_rcu() forward-progress testing. */ 3347 static void rcu_torture_fwd_prog_cr(struct rcu_fwd *rfp) 3348 { 3349 unsigned long cver; 3350 unsigned long flags; 3351 unsigned long gps; 3352 int i; 3353 long n_launders; 3354 long n_launders_cb_snap; 3355 long n_launders_sa; 3356 long n_max_cbs; 3357 long n_max_gps; 3358 struct rcu_fwd_cb *rfcp; 3359 struct rcu_fwd_cb *rfcpn; 3360 unsigned long stopat; 3361 unsigned long stoppedat; 3362 3363 pr_alert("%s: Starting forward-progress test %d\n", __func__, rfp->rcu_fwd_id); 3364 if (READ_ONCE(rcu_fwd_emergency_stop)) 3365 return; /* Get out of the way quickly, no GP wait! */ 3366 if (!cur_ops->call) 3367 return; /* Can't do call_rcu() fwd prog without ->call. */ 3368 3369 /* Loop continuously posting RCU callbacks. */ 3370 atomic_inc(&rcu_fwd_cb_nodelay); 3371 cur_ops->sync(); /* Later readers see above write. */ 3372 WRITE_ONCE(rfp->rcu_fwd_startat, jiffies); 3373 stopat = rfp->rcu_fwd_startat + MAX_FWD_CB_JIFFIES; 3374 n_launders = 0; 3375 rfp->n_launders_cb = 0; // Hoist initialization for multi-kthread 3376 n_launders_sa = 0; 3377 n_max_cbs = 0; 3378 n_max_gps = 0; 3379 for (i = 0; i < ARRAY_SIZE(rfp->n_launders_hist); i++) 3380 rfp->n_launders_hist[i].n_launders = 0; 3381 cver = READ_ONCE(rcu_torture_current_version); 3382 gps = cur_ops->get_gp_seq(); 3383 rfp->rcu_launder_gp_seq_start = gps; 3384 tick_dep_set_task(current, TICK_DEP_BIT_RCU); // CPU bound, so need tick. 3385 while (time_before(jiffies, stopat) && 3386 !shutdown_time_arrived() && 3387 !READ_ONCE(rcu_fwd_emergency_stop) && !torture_must_stop()) { 3388 rfcp = READ_ONCE(rfp->rcu_fwd_cb_head); 3389 rfcpn = NULL; 3390 if (rfcp) 3391 rfcpn = READ_ONCE(rfcp->rfc_next); 3392 if (rfcpn) { 3393 if (rfcp->rfc_gps >= MIN_FWD_CB_LAUNDERS && 3394 ++n_max_gps >= MIN_FWD_CBS_LAUNDERED) 3395 break; 3396 rfp->rcu_fwd_cb_head = rfcpn; 3397 n_launders++; 3398 n_launders_sa++; 3399 } else if (!cur_ops->cbflood_max || cur_ops->cbflood_max > n_max_cbs) { 3400 rfcp = kmalloc(sizeof(*rfcp), GFP_KERNEL); 3401 if (WARN_ON_ONCE(!rfcp)) { 3402 schedule_timeout_interruptible(1); 3403 continue; 3404 } 3405 n_max_cbs++; 3406 n_launders_sa = 0; 3407 rfcp->rfc_gps = 0; 3408 rfcp->rfc_rfp = rfp; 3409 } else { 3410 rfcp = NULL; 3411 } 3412 if (rfcp) 3413 cur_ops->call(&rfcp->rh, rcu_torture_fwd_cb_cr); 3414 rcu_torture_fwd_prog_cond_resched(n_launders + n_max_cbs); 3415 if (tick_nohz_full_enabled()) { 3416 local_irq_save(flags); 3417 rcu_momentary_eqs(); 3418 local_irq_restore(flags); 3419 } 3420 } 3421 stoppedat = jiffies; 3422 n_launders_cb_snap = READ_ONCE(rfp->n_launders_cb); 3423 cver = READ_ONCE(rcu_torture_current_version) - cver; 3424 gps = rcutorture_seq_diff(cur_ops->get_gp_seq(), gps); 3425 pr_alert("%s: Waiting for CBs: %pS() %d\n", __func__, cur_ops->cb_barrier, rfp->rcu_fwd_id); 3426 cur_ops->cb_barrier(); /* Wait for callbacks to be invoked. */ 3427 (void)rcu_torture_fwd_prog_cbfree(rfp); 3428 3429 if (!torture_must_stop() && !READ_ONCE(rcu_fwd_emergency_stop) && 3430 !shutdown_time_arrived()) { 3431 if (WARN_ON(n_max_gps < MIN_FWD_CBS_LAUNDERED) && cur_ops->gp_kthread_dbg) 3432 cur_ops->gp_kthread_dbg(); 3433 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 #online %u\n", 3434 __func__, 3435 stoppedat - rfp->rcu_fwd_startat, jiffies - stoppedat, 3436 n_launders + n_max_cbs - n_launders_cb_snap, 3437 n_launders, n_launders_sa, 3438 n_max_gps, n_max_cbs, cver, gps, num_online_cpus()); 3439 atomic_long_add(n_max_cbs, &rcu_fwd_max_cbs); 3440 mutex_lock(&rcu_fwd_mutex); // Serialize histograms. 3441 rcu_torture_fwd_cb_hist(rfp); 3442 mutex_unlock(&rcu_fwd_mutex); 3443 } 3444 schedule_timeout_uninterruptible(HZ); /* Let CBs drain. */ 3445 tick_dep_clear_task(current, TICK_DEP_BIT_RCU); 3446 atomic_dec(&rcu_fwd_cb_nodelay); 3447 } 3448 3449 3450 /* 3451 * OOM notifier, but this only prints diagnostic information for the 3452 * current forward-progress test. 3453 */ 3454 static int rcutorture_oom_notify(struct notifier_block *self, 3455 unsigned long notused, void *nfreed) 3456 { 3457 int i; 3458 long ncbs; 3459 struct rcu_fwd *rfp; 3460 3461 mutex_lock(&rcu_fwd_mutex); 3462 rfp = rcu_fwds; 3463 if (!rfp) { 3464 mutex_unlock(&rcu_fwd_mutex); 3465 return NOTIFY_OK; 3466 } 3467 WARN(1, "%s invoked upon OOM during forward-progress testing.\n", 3468 __func__); 3469 for (i = 0; i < fwd_progress; i++) { 3470 rcu_torture_fwd_cb_hist(&rfp[i]); 3471 rcu_fwd_progress_check(1 + (jiffies - READ_ONCE(rfp[i].rcu_fwd_startat)) / 2); 3472 } 3473 WRITE_ONCE(rcu_fwd_emergency_stop, true); 3474 smp_mb(); /* Emergency stop before free and wait to avoid hangs. */ 3475 ncbs = 0; 3476 for (i = 0; i < fwd_progress; i++) 3477 ncbs += rcu_torture_fwd_prog_cbfree(&rfp[i]); 3478 pr_info("%s: Freed %lu RCU callbacks.\n", __func__, ncbs); 3479 cur_ops->cb_barrier(); 3480 ncbs = 0; 3481 for (i = 0; i < fwd_progress; i++) 3482 ncbs += rcu_torture_fwd_prog_cbfree(&rfp[i]); 3483 pr_info("%s: Freed %lu RCU callbacks.\n", __func__, ncbs); 3484 cur_ops->cb_barrier(); 3485 ncbs = 0; 3486 for (i = 0; i < fwd_progress; i++) 3487 ncbs += rcu_torture_fwd_prog_cbfree(&rfp[i]); 3488 pr_info("%s: Freed %lu RCU callbacks.\n", __func__, ncbs); 3489 smp_mb(); /* Frees before return to avoid redoing OOM. */ 3490 (*(unsigned long *)nfreed)++; /* Forward progress CBs freed! */ 3491 pr_info("%s returning after OOM processing.\n", __func__); 3492 mutex_unlock(&rcu_fwd_mutex); 3493 return NOTIFY_OK; 3494 } 3495 3496 static struct notifier_block rcutorture_oom_nb = { 3497 .notifier_call = rcutorture_oom_notify 3498 }; 3499 3500 /* Carry out grace-period forward-progress testing. */ 3501 static int rcu_torture_fwd_prog(void *args) 3502 { 3503 bool firsttime = true; 3504 long max_cbs; 3505 int oldnice = task_nice(current); 3506 unsigned long oldseq = READ_ONCE(rcu_fwd_seq); 3507 struct rcu_fwd *rfp = args; 3508 int tested = 0; 3509 int tested_tries = 0; 3510 3511 VERBOSE_TOROUT_STRING("rcu_torture_fwd_progress task started"); 3512 while (!rcu_inkernel_boot_has_ended()) 3513 schedule_timeout_interruptible(HZ / 10); 3514 rcu_bind_current_to_nocb(); 3515 if (!IS_ENABLED(CONFIG_SMP) || !IS_ENABLED(CONFIG_RCU_BOOST)) 3516 set_user_nice(current, MAX_NICE); 3517 do { 3518 if (!rfp->rcu_fwd_id) { 3519 schedule_timeout_interruptible(fwd_progress_holdoff * HZ); 3520 WRITE_ONCE(rcu_fwd_emergency_stop, false); 3521 if (!firsttime) { 3522 max_cbs = atomic_long_xchg(&rcu_fwd_max_cbs, 0); 3523 pr_alert("%s n_max_cbs: %ld\n", __func__, max_cbs); 3524 } 3525 firsttime = false; 3526 WRITE_ONCE(rcu_fwd_seq, rcu_fwd_seq + 1); 3527 } else { 3528 while (READ_ONCE(rcu_fwd_seq) == oldseq && !torture_must_stop()) 3529 schedule_timeout_interruptible(HZ / 20); 3530 oldseq = READ_ONCE(rcu_fwd_seq); 3531 } 3532 pr_alert("%s: Starting forward-progress test %d\n", __func__, rfp->rcu_fwd_id); 3533 if (rcu_inkernel_boot_has_ended() && torture_num_online_cpus() > rfp->rcu_fwd_id) 3534 rcu_torture_fwd_prog_cr(rfp); 3535 if ((cur_ops->stall_dur && cur_ops->stall_dur() > 0) && 3536 (!IS_ENABLED(CONFIG_TINY_RCU) || 3537 (rcu_inkernel_boot_has_ended() && 3538 torture_num_online_cpus() > rfp->rcu_fwd_id))) 3539 rcu_torture_fwd_prog_nr(rfp, &tested, &tested_tries); 3540 3541 /* Avoid slow periods, better to test when busy. */ 3542 if (stutter_wait("rcu_torture_fwd_prog")) 3543 sched_set_normal(current, oldnice); 3544 } while (!torture_must_stop()); 3545 /* Short runs might not contain a valid forward-progress attempt. */ 3546 if (!rfp->rcu_fwd_id) { 3547 WARN_ON(!tested && tested_tries >= 5); 3548 pr_alert("%s: tested %d tested_tries %d\n", __func__, tested, tested_tries); 3549 } 3550 torture_kthread_stopping("rcu_torture_fwd_prog"); 3551 return 0; 3552 } 3553 3554 /* If forward-progress checking is requested and feasible, spawn the thread. */ 3555 static int __init rcu_torture_fwd_prog_init(void) 3556 { 3557 int i; 3558 int ret = 0; 3559 struct rcu_fwd *rfp; 3560 3561 if (!fwd_progress) 3562 return 0; /* Not requested, so don't do it. */ 3563 if (fwd_progress >= nr_cpu_ids) { 3564 VERBOSE_TOROUT_STRING("rcu_torture_fwd_prog_init: Limiting fwd_progress to # CPUs.\n"); 3565 fwd_progress = nr_cpu_ids; 3566 } else if (fwd_progress < 0) { 3567 fwd_progress = nr_cpu_ids; 3568 } 3569 if ((!cur_ops->sync && !cur_ops->call) || 3570 (!cur_ops->cbflood_max && (!cur_ops->stall_dur || cur_ops->stall_dur() <= 0)) || 3571 cur_ops == &rcu_busted_ops) { 3572 VERBOSE_TOROUT_STRING("rcu_torture_fwd_prog_init: Disabled, unsupported by RCU flavor under test"); 3573 fwd_progress = 0; 3574 return 0; 3575 } 3576 if (stall_cpu > 0 || (preempt_duration > 0 && IS_ENABLED(CONFIG_RCU_NOCB_CPU))) { 3577 VERBOSE_TOROUT_STRING("rcu_torture_fwd_prog_init: Disabled, conflicts with CPU-stall and/or preemption testing"); 3578 fwd_progress = 0; 3579 if (IS_MODULE(CONFIG_RCU_TORTURE_TEST)) 3580 return -EINVAL; /* In module, can fail back to user. */ 3581 WARN_ON(1); /* Make sure rcutorture scripting notices conflict. */ 3582 return 0; 3583 } 3584 if (fwd_progress_holdoff <= 0) 3585 fwd_progress_holdoff = 1; 3586 if (fwd_progress_div <= 0) 3587 fwd_progress_div = 4; 3588 rfp = kcalloc(fwd_progress, sizeof(*rfp), GFP_KERNEL); 3589 fwd_prog_tasks = kcalloc(fwd_progress, sizeof(*fwd_prog_tasks), GFP_KERNEL); 3590 if (!rfp || !fwd_prog_tasks) { 3591 kfree(rfp); 3592 kfree(fwd_prog_tasks); 3593 fwd_prog_tasks = NULL; 3594 fwd_progress = 0; 3595 return -ENOMEM; 3596 } 3597 for (i = 0; i < fwd_progress; i++) { 3598 spin_lock_init(&rfp[i].rcu_fwd_lock); 3599 rfp[i].rcu_fwd_cb_tail = &rfp[i].rcu_fwd_cb_head; 3600 rfp[i].rcu_fwd_id = i; 3601 } 3602 mutex_lock(&rcu_fwd_mutex); 3603 rcu_fwds = rfp; 3604 mutex_unlock(&rcu_fwd_mutex); 3605 register_oom_notifier(&rcutorture_oom_nb); 3606 for (i = 0; i < fwd_progress; i++) { 3607 ret = torture_create_kthread(rcu_torture_fwd_prog, &rcu_fwds[i], fwd_prog_tasks[i]); 3608 if (ret) { 3609 fwd_progress = i; 3610 return ret; 3611 } 3612 } 3613 return 0; 3614 } 3615 3616 static void rcu_torture_fwd_prog_cleanup(void) 3617 { 3618 int i; 3619 struct rcu_fwd *rfp; 3620 3621 if (!rcu_fwds || !fwd_prog_tasks) 3622 return; 3623 for (i = 0; i < fwd_progress; i++) 3624 torture_stop_kthread(rcu_torture_fwd_prog, fwd_prog_tasks[i]); 3625 unregister_oom_notifier(&rcutorture_oom_nb); 3626 mutex_lock(&rcu_fwd_mutex); 3627 rfp = rcu_fwds; 3628 rcu_fwds = NULL; 3629 mutex_unlock(&rcu_fwd_mutex); 3630 kfree(rfp); 3631 kfree(fwd_prog_tasks); 3632 fwd_prog_tasks = NULL; 3633 } 3634 3635 /* Callback function for RCU barrier testing. */ 3636 static void rcu_torture_barrier_cbf(struct rcu_head *rcu) 3637 { 3638 atomic_inc(&barrier_cbs_invoked); 3639 } 3640 3641 /* IPI handler to get callback posted on desired CPU, if online. */ 3642 static int rcu_torture_barrier1cb(void *rcu_void) 3643 { 3644 struct rcu_head *rhp = rcu_void; 3645 3646 cur_ops->call(rhp, rcu_torture_barrier_cbf); 3647 return 0; 3648 } 3649 3650 /* kthread function to register callbacks used to test RCU barriers. */ 3651 static int rcu_torture_barrier_cbs(void *arg) 3652 { 3653 long myid = (long)arg; 3654 bool lastphase = false; 3655 bool newphase; 3656 struct rcu_head rcu; 3657 3658 init_rcu_head_on_stack(&rcu); 3659 VERBOSE_TOROUT_STRING("rcu_torture_barrier_cbs task started"); 3660 set_user_nice(current, MAX_NICE); 3661 do { 3662 wait_event(barrier_cbs_wq[myid], 3663 (newphase = 3664 smp_load_acquire(&barrier_phase)) != lastphase || 3665 torture_must_stop()); 3666 lastphase = newphase; 3667 if (torture_must_stop()) 3668 break; 3669 /* 3670 * The above smp_load_acquire() ensures barrier_phase load 3671 * is ordered before the following ->call(). 3672 */ 3673 if (smp_call_on_cpu(myid, rcu_torture_barrier1cb, &rcu, 1)) 3674 cur_ops->call(&rcu, rcu_torture_barrier_cbf); 3675 3676 if (atomic_dec_and_test(&barrier_cbs_count)) 3677 wake_up(&barrier_wq); 3678 } while (!torture_must_stop()); 3679 if (cur_ops->cb_barrier != NULL) 3680 cur_ops->cb_barrier(); 3681 destroy_rcu_head_on_stack(&rcu); 3682 torture_kthread_stopping("rcu_torture_barrier_cbs"); 3683 return 0; 3684 } 3685 3686 /* kthread function to drive and coordinate RCU barrier testing. */ 3687 static int rcu_torture_barrier(void *arg) 3688 { 3689 int i; 3690 3691 VERBOSE_TOROUT_STRING("rcu_torture_barrier task starting"); 3692 do { 3693 atomic_set(&barrier_cbs_invoked, 0); 3694 atomic_set(&barrier_cbs_count, n_barrier_cbs); 3695 /* Ensure barrier_phase ordered after prior assignments. */ 3696 smp_store_release(&barrier_phase, !barrier_phase); 3697 for (i = 0; i < n_barrier_cbs; i++) 3698 wake_up(&barrier_cbs_wq[i]); 3699 wait_event(barrier_wq, 3700 atomic_read(&barrier_cbs_count) == 0 || 3701 torture_must_stop()); 3702 if (torture_must_stop()) 3703 break; 3704 n_barrier_attempts++; 3705 cur_ops->cb_barrier(); /* Implies smp_mb() for wait_event(). */ 3706 if (atomic_read(&barrier_cbs_invoked) != n_barrier_cbs) { 3707 n_rcu_torture_barrier_error++; 3708 pr_err("barrier_cbs_invoked = %d, n_barrier_cbs = %d\n", 3709 atomic_read(&barrier_cbs_invoked), 3710 n_barrier_cbs); 3711 WARN_ON(1); 3712 // Wait manually for the remaining callbacks 3713 i = 0; 3714 do { 3715 if (WARN_ON(i++ > HZ)) 3716 i = INT_MIN; 3717 schedule_timeout_interruptible(1); 3718 cur_ops->cb_barrier(); 3719 } while (atomic_read(&barrier_cbs_invoked) != 3720 n_barrier_cbs && 3721 !torture_must_stop()); 3722 smp_mb(); // Can't trust ordering if broken. 3723 if (!torture_must_stop()) 3724 pr_err("Recovered: barrier_cbs_invoked = %d\n", 3725 atomic_read(&barrier_cbs_invoked)); 3726 } else { 3727 n_barrier_successes++; 3728 } 3729 schedule_timeout_interruptible(HZ / 10); 3730 } while (!torture_must_stop()); 3731 torture_kthread_stopping("rcu_torture_barrier"); 3732 return 0; 3733 } 3734 3735 /* Initialize RCU barrier testing. */ 3736 static int rcu_torture_barrier_init(void) 3737 { 3738 int i; 3739 int ret; 3740 3741 if (n_barrier_cbs <= 0) 3742 return 0; 3743 if (cur_ops->call == NULL || cur_ops->cb_barrier == NULL) { 3744 pr_alert("%s" TORTURE_FLAG 3745 " Call or barrier ops missing for %s,\n", 3746 torture_type, cur_ops->name); 3747 pr_alert("%s" TORTURE_FLAG 3748 " RCU barrier testing omitted from run.\n", 3749 torture_type); 3750 return 0; 3751 } 3752 atomic_set(&barrier_cbs_count, 0); 3753 atomic_set(&barrier_cbs_invoked, 0); 3754 barrier_cbs_tasks = 3755 kcalloc(n_barrier_cbs, sizeof(barrier_cbs_tasks[0]), 3756 GFP_KERNEL); 3757 barrier_cbs_wq = 3758 kcalloc(n_barrier_cbs, sizeof(barrier_cbs_wq[0]), GFP_KERNEL); 3759 if (barrier_cbs_tasks == NULL || !barrier_cbs_wq) 3760 return -ENOMEM; 3761 for (i = 0; i < n_barrier_cbs; i++) { 3762 init_waitqueue_head(&barrier_cbs_wq[i]); 3763 ret = torture_create_kthread(rcu_torture_barrier_cbs, 3764 (void *)(long)i, 3765 barrier_cbs_tasks[i]); 3766 if (ret) 3767 return ret; 3768 } 3769 return torture_create_kthread(rcu_torture_barrier, NULL, barrier_task); 3770 } 3771 3772 /* Clean up after RCU barrier testing. */ 3773 static void rcu_torture_barrier_cleanup(void) 3774 { 3775 int i; 3776 3777 torture_stop_kthread(rcu_torture_barrier, barrier_task); 3778 if (barrier_cbs_tasks != NULL) { 3779 for (i = 0; i < n_barrier_cbs; i++) 3780 torture_stop_kthread(rcu_torture_barrier_cbs, 3781 barrier_cbs_tasks[i]); 3782 kfree(barrier_cbs_tasks); 3783 barrier_cbs_tasks = NULL; 3784 } 3785 if (barrier_cbs_wq != NULL) { 3786 kfree(barrier_cbs_wq); 3787 barrier_cbs_wq = NULL; 3788 } 3789 } 3790 3791 static bool rcu_torture_can_boost(void) 3792 { 3793 static int boost_warn_once; 3794 int prio; 3795 3796 if (!(test_boost == 1 && cur_ops->can_boost) && test_boost != 2) 3797 return false; 3798 if (!cur_ops->start_gp_poll || !cur_ops->poll_gp_state) 3799 return false; 3800 3801 prio = rcu_get_gp_kthreads_prio(); 3802 if (!prio) 3803 return false; 3804 3805 if (prio < 2) { 3806 if (boost_warn_once == 1) 3807 return false; 3808 3809 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); 3810 boost_warn_once = 1; 3811 return false; 3812 } 3813 3814 return true; 3815 } 3816 3817 static bool read_exit_child_stop; 3818 static bool read_exit_child_stopped; 3819 static wait_queue_head_t read_exit_wq; 3820 3821 // Child kthread which just does an rcutorture reader and exits. 3822 static int rcu_torture_read_exit_child(void *trsp_in) 3823 { 3824 struct torture_random_state *trsp = trsp_in; 3825 3826 set_user_nice(current, MAX_NICE); 3827 // Minimize time between reading and exiting. 3828 while (!kthread_should_stop()) 3829 schedule_timeout_uninterruptible(HZ / 20); 3830 (void)rcu_torture_one_read(trsp, -1); 3831 return 0; 3832 } 3833 3834 // Parent kthread which creates and destroys read-exit child kthreads. 3835 static int rcu_torture_read_exit(void *unused) 3836 { 3837 bool errexit = false; 3838 int i; 3839 struct task_struct *tsp; 3840 DEFINE_TORTURE_RANDOM(trs); 3841 3842 // Allocate and initialize. 3843 set_user_nice(current, MAX_NICE); 3844 VERBOSE_TOROUT_STRING("rcu_torture_read_exit: Start of test"); 3845 3846 // Each pass through this loop does one read-exit episode. 3847 do { 3848 VERBOSE_TOROUT_STRING("rcu_torture_read_exit: Start of episode"); 3849 for (i = 0; i < read_exit_burst; i++) { 3850 if (READ_ONCE(read_exit_child_stop)) 3851 break; 3852 stutter_wait("rcu_torture_read_exit"); 3853 // Spawn child. 3854 tsp = kthread_run(rcu_torture_read_exit_child, 3855 &trs, "%s", "rcu_torture_read_exit_child"); 3856 if (IS_ERR(tsp)) { 3857 TOROUT_ERRSTRING("out of memory"); 3858 errexit = true; 3859 break; 3860 } 3861 cond_resched(); 3862 kthread_stop(tsp); 3863 n_read_exits++; 3864 } 3865 VERBOSE_TOROUT_STRING("rcu_torture_read_exit: End of episode"); 3866 rcu_barrier(); // Wait for task_struct free, avoid OOM. 3867 i = 0; 3868 for (; !errexit && !READ_ONCE(read_exit_child_stop) && i < read_exit_delay; i++) 3869 schedule_timeout_uninterruptible(HZ); 3870 } while (!errexit && !READ_ONCE(read_exit_child_stop)); 3871 3872 // Clean up and exit. 3873 smp_store_release(&read_exit_child_stopped, true); // After reaping. 3874 smp_mb(); // Store before wakeup. 3875 wake_up(&read_exit_wq); 3876 while (!torture_must_stop()) 3877 schedule_timeout_uninterruptible(HZ / 20); 3878 torture_kthread_stopping("rcu_torture_read_exit"); 3879 return 0; 3880 } 3881 3882 static int rcu_torture_read_exit_init(void) 3883 { 3884 if (read_exit_burst <= 0) 3885 return 0; 3886 init_waitqueue_head(&read_exit_wq); 3887 read_exit_child_stop = false; 3888 read_exit_child_stopped = false; 3889 return torture_create_kthread(rcu_torture_read_exit, NULL, 3890 read_exit_task); 3891 } 3892 3893 static void rcu_torture_read_exit_cleanup(void) 3894 { 3895 if (!read_exit_task) 3896 return; 3897 WRITE_ONCE(read_exit_child_stop, true); 3898 smp_mb(); // Above write before wait. 3899 wait_event(read_exit_wq, smp_load_acquire(&read_exit_child_stopped)); 3900 torture_stop_kthread(rcutorture_read_exit, read_exit_task); 3901 } 3902 3903 static void rcutorture_test_nmis(int n) 3904 { 3905 #if IS_BUILTIN(CONFIG_RCU_TORTURE_TEST) 3906 int cpu; 3907 int dumpcpu; 3908 int i; 3909 3910 for (i = 0; i < n; i++) { 3911 preempt_disable(); 3912 cpu = smp_processor_id(); 3913 dumpcpu = cpu + 1; 3914 if (dumpcpu >= nr_cpu_ids) 3915 dumpcpu = 0; 3916 pr_alert("%s: CPU %d invoking dump_cpu_task(%d)\n", __func__, cpu, dumpcpu); 3917 dump_cpu_task(dumpcpu); 3918 preempt_enable(); 3919 schedule_timeout_uninterruptible(15 * HZ); 3920 } 3921 #else // #if IS_BUILTIN(CONFIG_RCU_TORTURE_TEST) 3922 WARN_ONCE(n, "Non-zero rcutorture.test_nmis=%d permitted only when rcutorture is built in.\n", test_nmis); 3923 #endif // #else // #if IS_BUILTIN(CONFIG_RCU_TORTURE_TEST) 3924 } 3925 3926 // Randomly preempt online CPUs. 3927 static int rcu_torture_preempt(void *unused) 3928 { 3929 int cpu = -1; 3930 DEFINE_TORTURE_RANDOM(rand); 3931 3932 schedule_timeout_idle(stall_cpu_holdoff); 3933 do { 3934 // Wait for preempt_interval ms with up to 100us fuzz. 3935 torture_hrtimeout_ms(preempt_interval, 100, &rand); 3936 // Select online CPU. 3937 cpu = cpumask_next(cpu, cpu_online_mask); 3938 if (cpu >= nr_cpu_ids) 3939 cpu = cpumask_next(-1, cpu_online_mask); 3940 WARN_ON_ONCE(cpu >= nr_cpu_ids); 3941 // Move to that CPU, if can't do so, retry later. 3942 if (torture_sched_setaffinity(current->pid, cpumask_of(cpu), false)) 3943 continue; 3944 // Preempt at high-ish priority, then reset to normal. 3945 sched_set_fifo(current); 3946 torture_sched_setaffinity(current->pid, cpu_present_mask, true); 3947 mdelay(preempt_duration); 3948 sched_set_normal(current, 0); 3949 stutter_wait("rcu_torture_preempt"); 3950 } while (!torture_must_stop()); 3951 torture_kthread_stopping("rcu_torture_preempt"); 3952 return 0; 3953 } 3954 3955 static enum cpuhp_state rcutor_hp; 3956 3957 static struct hrtimer gpwrap_lag_timer; 3958 static bool gpwrap_lag_active; 3959 3960 /* Timer handler for toggling RCU grace-period sequence overflow test lag value */ 3961 static enum hrtimer_restart rcu_gpwrap_lag_timer(struct hrtimer *timer) 3962 { 3963 ktime_t next_delay; 3964 3965 if (gpwrap_lag_active) { 3966 pr_alert("rcu-torture: Disabling gpwrap lag (value=0)\n"); 3967 cur_ops->set_gpwrap_lag(0); 3968 gpwrap_lag_active = false; 3969 next_delay = ktime_set((gpwrap_lag_cycle_mins - gpwrap_lag_active_mins) * 60, 0); 3970 } else { 3971 pr_alert("rcu-torture: Enabling gpwrap lag (value=%d)\n", gpwrap_lag_gps); 3972 cur_ops->set_gpwrap_lag(gpwrap_lag_gps); 3973 gpwrap_lag_active = true; 3974 next_delay = ktime_set(gpwrap_lag_active_mins * 60, 0); 3975 } 3976 3977 if (torture_must_stop_irq()) 3978 return HRTIMER_NORESTART; 3979 3980 hrtimer_forward_now(timer, next_delay); 3981 return HRTIMER_RESTART; 3982 } 3983 3984 static int rcu_gpwrap_lag_init(void) 3985 { 3986 if (!gpwrap_lag) 3987 return 0; 3988 3989 if (gpwrap_lag_cycle_mins <= 0 || gpwrap_lag_active_mins <= 0) { 3990 pr_alert("rcu-torture: lag timing parameters must be positive\n"); 3991 return -EINVAL; 3992 } 3993 3994 hrtimer_setup(&gpwrap_lag_timer, rcu_gpwrap_lag_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); 3995 gpwrap_lag_active = false; 3996 hrtimer_start(&gpwrap_lag_timer, 3997 ktime_set((gpwrap_lag_cycle_mins - gpwrap_lag_active_mins) * 60, 0), HRTIMER_MODE_REL); 3998 3999 return 0; 4000 } 4001 4002 static void rcu_gpwrap_lag_cleanup(void) 4003 { 4004 hrtimer_cancel(&gpwrap_lag_timer); 4005 cur_ops->set_gpwrap_lag(0); 4006 gpwrap_lag_active = false; 4007 } 4008 static void 4009 rcu_torture_cleanup(void) 4010 { 4011 int firsttime; 4012 int flags = 0; 4013 unsigned long gp_seq = 0; 4014 int i; 4015 int j; 4016 4017 if (torture_cleanup_begin()) { 4018 if (cur_ops->cb_barrier != NULL) { 4019 pr_info("%s: Invoking %pS().\n", __func__, cur_ops->cb_barrier); 4020 cur_ops->cb_barrier(); 4021 } 4022 if (cur_ops->gp_slow_unregister) 4023 cur_ops->gp_slow_unregister(NULL); 4024 return; 4025 } 4026 if (!cur_ops) { 4027 torture_cleanup_end(); 4028 return; 4029 } 4030 4031 rcutorture_test_nmis(test_nmis); 4032 4033 if (cur_ops->gp_kthread_dbg) 4034 cur_ops->gp_kthread_dbg(); 4035 torture_stop_kthread(rcu_torture_preempt, preempt_task); 4036 rcu_torture_read_exit_cleanup(); 4037 rcu_torture_barrier_cleanup(); 4038 rcu_torture_fwd_prog_cleanup(); 4039 torture_stop_kthread(rcu_torture_stall, stall_task); 4040 torture_stop_kthread(rcu_torture_writer, writer_task); 4041 4042 if (nocb_tasks) { 4043 for (i = 0; i < nrealnocbers; i++) 4044 torture_stop_kthread(rcu_nocb_toggle, nocb_tasks[i]); 4045 kfree(nocb_tasks); 4046 nocb_tasks = NULL; 4047 } 4048 4049 if (updown_task) { 4050 torture_stop_kthread(rcu_torture_updown, updown_task); 4051 updown_task = NULL; 4052 } 4053 if (reader_tasks) { 4054 for (i = 0; i < nrealreaders; i++) 4055 torture_stop_kthread(rcu_torture_reader, 4056 reader_tasks[i]); 4057 kfree(reader_tasks); 4058 reader_tasks = NULL; 4059 } 4060 kfree(rcu_torture_reader_mbchk); 4061 rcu_torture_reader_mbchk = NULL; 4062 4063 if (fakewriter_tasks) { 4064 for (i = 0; i < nrealfakewriters; i++) 4065 torture_stop_kthread(rcu_torture_fakewriter, 4066 fakewriter_tasks[i]); 4067 kfree(fakewriter_tasks); 4068 fakewriter_tasks = NULL; 4069 } 4070 4071 if (cur_ops->get_gp_data) 4072 cur_ops->get_gp_data(&flags, &gp_seq); 4073 pr_alert("%s: End-test grace-period state: g%ld f%#x total-gps=%ld\n", 4074 cur_ops->name, (long)gp_seq, flags, 4075 rcutorture_seq_diff(gp_seq, start_gp_seq)); 4076 torture_stop_kthread(rcu_torture_stats, stats_task); 4077 torture_stop_kthread(rcu_torture_fqs, fqs_task); 4078 if (rcu_torture_can_boost() && rcutor_hp >= 0) 4079 cpuhp_remove_state(rcutor_hp); 4080 4081 /* 4082 * Wait for all RCU callbacks to fire, then do torture-type-specific 4083 * cleanup operations. 4084 */ 4085 if (cur_ops->cb_barrier != NULL) { 4086 pr_info("%s: Invoking %pS().\n", __func__, cur_ops->cb_barrier); 4087 cur_ops->cb_barrier(); 4088 } 4089 if (cur_ops->cleanup != NULL) 4090 cur_ops->cleanup(); 4091 4092 rcu_torture_mem_dump_obj(); 4093 4094 rcu_torture_stats_print(); /* -After- the stats thread is stopped! */ 4095 4096 if (err_segs_recorded) { 4097 pr_alert("Failure/close-call rcutorture reader segments:\n"); 4098 if (rt_read_nsegs == 0) 4099 pr_alert("\t: No segments recorded!!!\n"); 4100 firsttime = 1; 4101 for (i = 0; i < rt_read_nsegs; i++) { 4102 if (IS_ENABLED(CONFIG_RCU_TORTURE_TEST_LOG_GP)) 4103 pr_alert("\t%lluus ", div64_u64(err_segs[i].rt_ts, 1000ULL)); 4104 else 4105 pr_alert("\t"); 4106 pr_cont("%d: %#4x", i, err_segs[i].rt_readstate); 4107 if (err_segs[i].rt_delay_jiffies != 0) { 4108 pr_cont("%s%ldjiffies", firsttime ? "" : "+", 4109 err_segs[i].rt_delay_jiffies); 4110 firsttime = 0; 4111 } 4112 if (IS_ENABLED(CONFIG_RCU_TORTURE_TEST_LOG_CPU)) { 4113 pr_cont(" CPU %2d", err_segs[i].rt_cpu); 4114 if (err_segs[i].rt_cpu != err_segs[i].rt_end_cpu) 4115 pr_cont("->%-2d", err_segs[i].rt_end_cpu); 4116 else 4117 pr_cont(" ..."); 4118 } 4119 if (IS_ENABLED(CONFIG_RCU_TORTURE_TEST_LOG_GP) && 4120 cur_ops->gather_gp_seqs && cur_ops->format_gp_seqs) { 4121 char buf1[20+1]; 4122 char buf2[20+1]; 4123 char sepchar = '-'; 4124 4125 cur_ops->format_gp_seqs(err_segs[i].rt_gp_seq, 4126 buf1, ARRAY_SIZE(buf1)); 4127 cur_ops->format_gp_seqs(err_segs[i].rt_gp_seq_end, 4128 buf2, ARRAY_SIZE(buf2)); 4129 if (err_segs[i].rt_gp_seq == err_segs[i].rt_gp_seq_end) { 4130 if (buf2[0]) { 4131 for (j = 0; buf2[j]; j++) 4132 buf2[j] = '.'; 4133 if (j) 4134 buf2[j - 1] = ' '; 4135 } 4136 sepchar = ' '; 4137 } 4138 pr_cont(" %s%c%s", buf1, sepchar, buf2); 4139 } 4140 if (err_segs[i].rt_delay_ms != 0) { 4141 pr_cont(" %s%ldms", firsttime ? "" : "+", 4142 err_segs[i].rt_delay_ms); 4143 firsttime = 0; 4144 } 4145 if (err_segs[i].rt_delay_us != 0) { 4146 pr_cont(" %s%ldus", firsttime ? "" : "+", 4147 err_segs[i].rt_delay_us); 4148 firsttime = 0; 4149 } 4150 pr_cont("%s", err_segs[i].rt_preempted ? " preempted" : ""); 4151 if (err_segs[i].rt_readstate & RCUTORTURE_RDR_BH) 4152 pr_cont(" BH"); 4153 if (err_segs[i].rt_readstate & RCUTORTURE_RDR_IRQ) 4154 pr_cont(" IRQ"); 4155 if (err_segs[i].rt_readstate & RCUTORTURE_RDR_PREEMPT) 4156 pr_cont(" PREEMPT"); 4157 if (err_segs[i].rt_readstate & RCUTORTURE_RDR_RBH) 4158 pr_cont(" RBH"); 4159 if (err_segs[i].rt_readstate & RCUTORTURE_RDR_SCHED) 4160 pr_cont(" SCHED"); 4161 if (err_segs[i].rt_readstate & RCUTORTURE_RDR_RCU_1) 4162 pr_cont(" RCU_1"); 4163 if (err_segs[i].rt_readstate & RCUTORTURE_RDR_RCU_2) 4164 pr_cont(" RCU_2"); 4165 pr_cont("\n"); 4166 4167 } 4168 if (rt_read_preempted) 4169 pr_alert("\tReader was preempted.\n"); 4170 } 4171 if (atomic_read(&n_rcu_torture_error) || n_rcu_torture_barrier_error) 4172 rcu_torture_print_module_parms(cur_ops, "End of test: FAILURE"); 4173 else if (torture_onoff_failures()) 4174 rcu_torture_print_module_parms(cur_ops, 4175 "End of test: RCU_HOTPLUG"); 4176 else 4177 rcu_torture_print_module_parms(cur_ops, "End of test: SUCCESS"); 4178 torture_cleanup_end(); 4179 if (cur_ops->gp_slow_unregister) 4180 cur_ops->gp_slow_unregister(NULL); 4181 4182 if (gpwrap_lag && cur_ops->set_gpwrap_lag) 4183 rcu_gpwrap_lag_cleanup(); 4184 } 4185 4186 static void rcu_torture_leak_cb(struct rcu_head *rhp) 4187 { 4188 } 4189 4190 static void rcu_torture_err_cb(struct rcu_head *rhp) 4191 { 4192 /* 4193 * This -might- happen due to race conditions, but is unlikely. 4194 * The scenario that leads to this happening is that the 4195 * first of the pair of duplicate callbacks is queued, 4196 * someone else starts a grace period that includes that 4197 * callback, then the second of the pair must wait for the 4198 * next grace period. Unlikely, but can happen. If it 4199 * does happen, the debug-objects subsystem won't have splatted. 4200 */ 4201 pr_alert("%s: duplicated callback was invoked.\n", KBUILD_MODNAME); 4202 } 4203 4204 /* 4205 * Verify that double-free causes debug-objects to complain, but only 4206 * if CONFIG_DEBUG_OBJECTS_RCU_HEAD=y. Otherwise, say that the test 4207 * cannot be carried out. 4208 */ 4209 static void rcu_test_debug_objects(void) 4210 { 4211 struct rcu_head rh1; 4212 struct rcu_head rh2; 4213 int idx; 4214 4215 if (!IS_ENABLED(CONFIG_DEBUG_OBJECTS_RCU_HEAD)) { 4216 pr_alert("%s: !CONFIG_DEBUG_OBJECTS_RCU_HEAD, not testing duplicate call_%s()\n", 4217 KBUILD_MODNAME, cur_ops->name); 4218 return; 4219 } 4220 4221 if (WARN_ON_ONCE(cur_ops->debug_objects && 4222 (!cur_ops->call || !cur_ops->cb_barrier))) 4223 return; 4224 4225 struct rcu_head *rhp = kmalloc(sizeof(*rhp), GFP_KERNEL); 4226 4227 init_rcu_head_on_stack(&rh1); 4228 init_rcu_head_on_stack(&rh2); 4229 pr_alert("%s: WARN: Duplicate call_%s() test starting.\n", KBUILD_MODNAME, cur_ops->name); 4230 4231 /* Try to queue the rh2 pair of callbacks for the same grace period. */ 4232 idx = cur_ops->readlock(); /* Make it impossible to finish a grace period. */ 4233 cur_ops->call(&rh1, rcu_torture_leak_cb); /* Start grace period. */ 4234 cur_ops->call(&rh2, rcu_torture_leak_cb); 4235 cur_ops->call(&rh2, rcu_torture_err_cb); /* Duplicate callback. */ 4236 if (rhp) { 4237 cur_ops->call(rhp, rcu_torture_leak_cb); 4238 cur_ops->call(rhp, rcu_torture_err_cb); /* Another duplicate callback. */ 4239 } 4240 cur_ops->readunlock(idx); 4241 4242 /* Wait for them all to get done so we can safely return. */ 4243 cur_ops->cb_barrier(); 4244 pr_alert("%s: WARN: Duplicate call_%s() test complete.\n", KBUILD_MODNAME, cur_ops->name); 4245 destroy_rcu_head_on_stack(&rh1); 4246 destroy_rcu_head_on_stack(&rh2); 4247 kfree(rhp); 4248 } 4249 4250 static void rcutorture_sync(void) 4251 { 4252 static unsigned long n; 4253 4254 if (cur_ops->sync && !(++n & 0xfff)) 4255 cur_ops->sync(); 4256 } 4257 4258 static DEFINE_MUTEX(mut0); 4259 static DEFINE_MUTEX(mut1); 4260 static DEFINE_MUTEX(mut2); 4261 static DEFINE_MUTEX(mut3); 4262 static DEFINE_MUTEX(mut4); 4263 static DEFINE_MUTEX(mut5); 4264 static DEFINE_MUTEX(mut6); 4265 static DEFINE_MUTEX(mut7); 4266 static DEFINE_MUTEX(mut8); 4267 static DEFINE_MUTEX(mut9); 4268 4269 static DECLARE_RWSEM(rwsem0); 4270 static DECLARE_RWSEM(rwsem1); 4271 static DECLARE_RWSEM(rwsem2); 4272 static DECLARE_RWSEM(rwsem3); 4273 static DECLARE_RWSEM(rwsem4); 4274 static DECLARE_RWSEM(rwsem5); 4275 static DECLARE_RWSEM(rwsem6); 4276 static DECLARE_RWSEM(rwsem7); 4277 static DECLARE_RWSEM(rwsem8); 4278 static DECLARE_RWSEM(rwsem9); 4279 4280 DEFINE_STATIC_SRCU(srcu0); 4281 DEFINE_STATIC_SRCU(srcu1); 4282 DEFINE_STATIC_SRCU(srcu2); 4283 DEFINE_STATIC_SRCU(srcu3); 4284 DEFINE_STATIC_SRCU(srcu4); 4285 DEFINE_STATIC_SRCU(srcu5); 4286 DEFINE_STATIC_SRCU(srcu6); 4287 DEFINE_STATIC_SRCU(srcu7); 4288 DEFINE_STATIC_SRCU(srcu8); 4289 DEFINE_STATIC_SRCU(srcu9); 4290 4291 static int srcu_lockdep_next(const char *f, const char *fl, const char *fs, const char *fu, int i, 4292 int cyclelen, int deadlock) 4293 { 4294 int j = i + 1; 4295 4296 if (j >= cyclelen) 4297 j = deadlock ? 0 : -1; 4298 if (j >= 0) 4299 pr_info("%s: %s(%d), %s(%d), %s(%d)\n", f, fl, i, fs, j, fu, i); 4300 else 4301 pr_info("%s: %s(%d), %s(%d)\n", f, fl, i, fu, i); 4302 return j; 4303 } 4304 4305 // Test lockdep on SRCU-based deadlock scenarios. 4306 static void rcu_torture_init_srcu_lockdep(void) 4307 { 4308 int cyclelen; 4309 int deadlock; 4310 bool err = false; 4311 int i; 4312 int j; 4313 int idx; 4314 struct mutex *muts[] = { &mut0, &mut1, &mut2, &mut3, &mut4, 4315 &mut5, &mut6, &mut7, &mut8, &mut9 }; 4316 struct rw_semaphore *rwsems[] = { &rwsem0, &rwsem1, &rwsem2, &rwsem3, &rwsem4, 4317 &rwsem5, &rwsem6, &rwsem7, &rwsem8, &rwsem9 }; 4318 struct srcu_struct *srcus[] = { &srcu0, &srcu1, &srcu2, &srcu3, &srcu4, 4319 &srcu5, &srcu6, &srcu7, &srcu8, &srcu9 }; 4320 int testtype; 4321 4322 if (!test_srcu_lockdep) 4323 return; 4324 4325 deadlock = test_srcu_lockdep / 1000; 4326 testtype = (test_srcu_lockdep / 10) % 100; 4327 cyclelen = test_srcu_lockdep % 10; 4328 WARN_ON_ONCE(ARRAY_SIZE(muts) != ARRAY_SIZE(srcus)); 4329 if (WARN_ONCE(deadlock != !!deadlock, 4330 "%s: test_srcu_lockdep=%d and deadlock digit %d must be zero or one.\n", 4331 __func__, test_srcu_lockdep, deadlock)) 4332 err = true; 4333 if (WARN_ONCE(cyclelen <= 0, 4334 "%s: test_srcu_lockdep=%d and cycle-length digit %d must be greater than zero.\n", 4335 __func__, test_srcu_lockdep, cyclelen)) 4336 err = true; 4337 if (err) 4338 goto err_out; 4339 4340 if (testtype == 0) { 4341 pr_info("%s: test_srcu_lockdep = %05d: SRCU %d-way %sdeadlock.\n", 4342 __func__, test_srcu_lockdep, cyclelen, deadlock ? "" : "non-"); 4343 if (deadlock && cyclelen == 1) 4344 pr_info("%s: Expect hang.\n", __func__); 4345 for (i = 0; i < cyclelen; i++) { 4346 j = srcu_lockdep_next(__func__, "srcu_read_lock", "synchronize_srcu", 4347 "srcu_read_unlock", i, cyclelen, deadlock); 4348 idx = srcu_read_lock(srcus[i]); 4349 if (j >= 0) 4350 synchronize_srcu(srcus[j]); 4351 srcu_read_unlock(srcus[i], idx); 4352 } 4353 return; 4354 } 4355 4356 if (testtype == 1) { 4357 pr_info("%s: test_srcu_lockdep = %05d: SRCU/mutex %d-way %sdeadlock.\n", 4358 __func__, test_srcu_lockdep, cyclelen, deadlock ? "" : "non-"); 4359 for (i = 0; i < cyclelen; i++) { 4360 pr_info("%s: srcu_read_lock(%d), mutex_lock(%d), mutex_unlock(%d), srcu_read_unlock(%d)\n", 4361 __func__, i, i, i, i); 4362 idx = srcu_read_lock(srcus[i]); 4363 mutex_lock(muts[i]); 4364 mutex_unlock(muts[i]); 4365 srcu_read_unlock(srcus[i], idx); 4366 4367 j = srcu_lockdep_next(__func__, "mutex_lock", "synchronize_srcu", 4368 "mutex_unlock", i, cyclelen, deadlock); 4369 mutex_lock(muts[i]); 4370 if (j >= 0) 4371 synchronize_srcu(srcus[j]); 4372 mutex_unlock(muts[i]); 4373 } 4374 return; 4375 } 4376 4377 if (testtype == 2) { 4378 pr_info("%s: test_srcu_lockdep = %05d: SRCU/rwsem %d-way %sdeadlock.\n", 4379 __func__, test_srcu_lockdep, cyclelen, deadlock ? "" : "non-"); 4380 for (i = 0; i < cyclelen; i++) { 4381 pr_info("%s: srcu_read_lock(%d), down_read(%d), up_read(%d), srcu_read_unlock(%d)\n", 4382 __func__, i, i, i, i); 4383 idx = srcu_read_lock(srcus[i]); 4384 down_read(rwsems[i]); 4385 up_read(rwsems[i]); 4386 srcu_read_unlock(srcus[i], idx); 4387 4388 j = srcu_lockdep_next(__func__, "down_write", "synchronize_srcu", 4389 "up_write", i, cyclelen, deadlock); 4390 down_write(rwsems[i]); 4391 if (j >= 0) 4392 synchronize_srcu(srcus[j]); 4393 up_write(rwsems[i]); 4394 } 4395 return; 4396 } 4397 4398 #ifdef CONFIG_TASKS_TRACE_RCU 4399 if (testtype == 3) { 4400 pr_info("%s: test_srcu_lockdep = %05d: SRCU and Tasks Trace RCU %d-way %sdeadlock.\n", 4401 __func__, test_srcu_lockdep, cyclelen, deadlock ? "" : "non-"); 4402 if (deadlock && cyclelen == 1) 4403 pr_info("%s: Expect hang.\n", __func__); 4404 for (i = 0; i < cyclelen; i++) { 4405 char *fl = i == 0 ? "rcu_read_lock_trace" : "srcu_read_lock"; 4406 char *fs = i == cyclelen - 1 ? "synchronize_rcu_tasks_trace" 4407 : "synchronize_srcu"; 4408 char *fu = i == 0 ? "rcu_read_unlock_trace" : "srcu_read_unlock"; 4409 4410 j = srcu_lockdep_next(__func__, fl, fs, fu, i, cyclelen, deadlock); 4411 if (i == 0) 4412 rcu_read_lock_trace(); 4413 else 4414 idx = srcu_read_lock(srcus[i]); 4415 if (j >= 0) { 4416 if (i == cyclelen - 1) 4417 synchronize_rcu_tasks_trace(); 4418 else 4419 synchronize_srcu(srcus[j]); 4420 } 4421 if (i == 0) 4422 rcu_read_unlock_trace(); 4423 else 4424 srcu_read_unlock(srcus[i], idx); 4425 } 4426 return; 4427 } 4428 #endif // #ifdef CONFIG_TASKS_TRACE_RCU 4429 4430 err_out: 4431 pr_info("%s: test_srcu_lockdep = %05d does nothing.\n", __func__, test_srcu_lockdep); 4432 pr_info("%s: test_srcu_lockdep = DNNL.\n", __func__); 4433 pr_info("%s: D: Deadlock if nonzero.\n", __func__); 4434 pr_info("%s: NN: Test number, 0=SRCU, 1=SRCU/mutex, 2=SRCU/rwsem, 3=SRCU/Tasks Trace RCU.\n", __func__); 4435 pr_info("%s: L: Cycle length.\n", __func__); 4436 if (!IS_ENABLED(CONFIG_TASKS_TRACE_RCU)) 4437 pr_info("%s: NN=3 disallowed because kernel is built with CONFIG_TASKS_TRACE_RCU=n\n", __func__); 4438 } 4439 4440 static int __init 4441 rcu_torture_init(void) 4442 { 4443 long i; 4444 int cpu; 4445 int firsterr = 0; 4446 int flags = 0; 4447 unsigned long gp_seq = 0; 4448 static struct rcu_torture_ops *torture_ops[] = { 4449 &rcu_ops, &rcu_busted_ops, &srcu_ops, &srcud_ops, &busted_srcud_ops, 4450 TASKS_OPS TASKS_RUDE_OPS TASKS_TRACING_OPS 4451 &trivial_ops, 4452 }; 4453 4454 if (!torture_init_begin(torture_type, verbose)) 4455 return -EBUSY; 4456 4457 /* Process args and tell the world that the torturer is on the job. */ 4458 for (i = 0; i < ARRAY_SIZE(torture_ops); i++) { 4459 cur_ops = torture_ops[i]; 4460 if (strcmp(torture_type, cur_ops->name) == 0) 4461 break; 4462 } 4463 if (i == ARRAY_SIZE(torture_ops)) { 4464 pr_alert("rcu-torture: invalid torture type: \"%s\"\n", 4465 torture_type); 4466 pr_alert("rcu-torture types:"); 4467 for (i = 0; i < ARRAY_SIZE(torture_ops); i++) 4468 pr_cont(" %s", torture_ops[i]->name); 4469 pr_cont("\n"); 4470 firsterr = -EINVAL; 4471 cur_ops = NULL; 4472 goto unwind; 4473 } 4474 if (cur_ops->fqs == NULL && fqs_duration != 0) { 4475 pr_alert("rcu-torture: ->fqs NULL and non-zero fqs_duration, fqs disabled.\n"); 4476 fqs_duration = 0; 4477 } 4478 if (nocbs_nthreads != 0 && (cur_ops != &rcu_ops || 4479 !IS_ENABLED(CONFIG_RCU_NOCB_CPU))) { 4480 pr_alert("rcu-torture types: %s and CONFIG_RCU_NOCB_CPU=%d, nocb toggle disabled.\n", 4481 cur_ops->name, IS_ENABLED(CONFIG_RCU_NOCB_CPU)); 4482 nocbs_nthreads = 0; 4483 } 4484 if (cur_ops->init) 4485 cur_ops->init(); 4486 4487 rcu_torture_init_srcu_lockdep(); 4488 4489 if (nfakewriters >= 0) { 4490 nrealfakewriters = nfakewriters; 4491 } else { 4492 nrealfakewriters = num_online_cpus() - 2 - nfakewriters; 4493 if (nrealfakewriters <= 0) 4494 nrealfakewriters = 1; 4495 } 4496 4497 if (nreaders >= 0) { 4498 nrealreaders = nreaders; 4499 } else { 4500 nrealreaders = num_online_cpus() - 2 - nreaders; 4501 if (nrealreaders <= 0) 4502 nrealreaders = 1; 4503 } 4504 rcu_torture_print_module_parms(cur_ops, "Start of test"); 4505 if (cur_ops->get_gp_data) 4506 cur_ops->get_gp_data(&flags, &gp_seq); 4507 start_gp_seq = gp_seq; 4508 pr_alert("%s: Start-test grace-period state: g%ld f%#x\n", 4509 cur_ops->name, (long)gp_seq, flags); 4510 4511 /* Set up the freelist. */ 4512 4513 INIT_LIST_HEAD(&rcu_torture_freelist); 4514 for (i = 0; i < ARRAY_SIZE(rcu_tortures); i++) { 4515 rcu_tortures[i].rtort_mbtest = 0; 4516 list_add_tail(&rcu_tortures[i].rtort_free, 4517 &rcu_torture_freelist); 4518 } 4519 4520 /* Initialize the statistics so that each run gets its own numbers. */ 4521 4522 rcu_torture_current = NULL; 4523 rcu_torture_current_version = 0; 4524 atomic_set(&n_rcu_torture_alloc, 0); 4525 atomic_set(&n_rcu_torture_alloc_fail, 0); 4526 atomic_set(&n_rcu_torture_free, 0); 4527 atomic_set(&n_rcu_torture_mberror, 0); 4528 atomic_set(&n_rcu_torture_mbchk_fail, 0); 4529 atomic_set(&n_rcu_torture_mbchk_tries, 0); 4530 atomic_set(&n_rcu_torture_error, 0); 4531 n_rcu_torture_barrier_error = 0; 4532 n_rcu_torture_boost_ktrerror = 0; 4533 n_rcu_torture_boost_failure = 0; 4534 n_rcu_torture_boosts = 0; 4535 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) 4536 atomic_set(&rcu_torture_wcount[i], 0); 4537 for_each_possible_cpu(cpu) { 4538 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) { 4539 per_cpu(rcu_torture_count, cpu)[i] = 0; 4540 per_cpu(rcu_torture_batch, cpu)[i] = 0; 4541 } 4542 } 4543 err_segs_recorded = 0; 4544 rt_read_nsegs = 0; 4545 4546 /* Start up the kthreads. */ 4547 4548 rcu_torture_write_types(); 4549 if (nrealfakewriters > 0) { 4550 fakewriter_tasks = kcalloc(nrealfakewriters, 4551 sizeof(fakewriter_tasks[0]), 4552 GFP_KERNEL); 4553 if (fakewriter_tasks == NULL) { 4554 TOROUT_ERRSTRING("out of memory"); 4555 firsterr = -ENOMEM; 4556 goto unwind; 4557 } 4558 } 4559 for (i = 0; i < nrealfakewriters; i++) { 4560 firsterr = torture_create_kthread(rcu_torture_fakewriter, 4561 NULL, fakewriter_tasks[i]); 4562 if (torture_init_error(firsterr)) 4563 goto unwind; 4564 } 4565 reader_tasks = kcalloc(nrealreaders, sizeof(reader_tasks[0]), 4566 GFP_KERNEL); 4567 rcu_torture_reader_mbchk = kcalloc(nrealreaders, sizeof(*rcu_torture_reader_mbchk), 4568 GFP_KERNEL); 4569 if (!reader_tasks || !rcu_torture_reader_mbchk) { 4570 TOROUT_ERRSTRING("out of memory"); 4571 firsterr = -ENOMEM; 4572 goto unwind; 4573 } 4574 for (i = 0; i < nrealreaders; i++) { 4575 rcu_torture_reader_mbchk[i].rtc_chkrdr = -1; 4576 firsterr = torture_create_kthread(rcu_torture_reader, (void *)i, 4577 reader_tasks[i]); 4578 if (torture_init_error(firsterr)) 4579 goto unwind; 4580 } 4581 4582 firsterr = torture_create_kthread(rcu_torture_writer, NULL, 4583 writer_task); 4584 if (torture_init_error(firsterr)) 4585 goto unwind; 4586 4587 firsterr = rcu_torture_updown_init(); 4588 if (torture_init_error(firsterr)) 4589 goto unwind; 4590 nrealnocbers = nocbs_nthreads; 4591 if (WARN_ON(nrealnocbers < 0)) 4592 nrealnocbers = 1; 4593 if (WARN_ON(nocbs_toggle < 0)) 4594 nocbs_toggle = HZ; 4595 if (nrealnocbers > 0) { 4596 nocb_tasks = kcalloc(nrealnocbers, sizeof(nocb_tasks[0]), GFP_KERNEL); 4597 if (nocb_tasks == NULL) { 4598 TOROUT_ERRSTRING("out of memory"); 4599 firsterr = -ENOMEM; 4600 goto unwind; 4601 } 4602 } else { 4603 nocb_tasks = NULL; 4604 } 4605 for (i = 0; i < nrealnocbers; i++) { 4606 firsterr = torture_create_kthread(rcu_nocb_toggle, NULL, nocb_tasks[i]); 4607 if (torture_init_error(firsterr)) 4608 goto unwind; 4609 } 4610 if (stat_interval > 0) { 4611 firsterr = torture_create_kthread(rcu_torture_stats, NULL, 4612 stats_task); 4613 if (torture_init_error(firsterr)) 4614 goto unwind; 4615 } 4616 if (test_no_idle_hz && shuffle_interval > 0) { 4617 firsterr = torture_shuffle_init(shuffle_interval * HZ); 4618 if (torture_init_error(firsterr)) 4619 goto unwind; 4620 } 4621 if (stutter < 0) 4622 stutter = 0; 4623 if (stutter) { 4624 int t; 4625 4626 t = cur_ops->stall_dur ? cur_ops->stall_dur() : stutter * HZ; 4627 firsterr = torture_stutter_init(stutter * HZ, t); 4628 if (torture_init_error(firsterr)) 4629 goto unwind; 4630 } 4631 if (fqs_duration < 0) 4632 fqs_duration = 0; 4633 if (fqs_holdoff < 0) 4634 fqs_holdoff = 0; 4635 if (fqs_duration && fqs_holdoff) { 4636 /* Create the fqs thread */ 4637 firsterr = torture_create_kthread(rcu_torture_fqs, NULL, 4638 fqs_task); 4639 if (torture_init_error(firsterr)) 4640 goto unwind; 4641 } 4642 if (test_boost_interval < 1) 4643 test_boost_interval = 1; 4644 if (test_boost_duration < 2) 4645 test_boost_duration = 2; 4646 if (rcu_torture_can_boost()) { 4647 4648 boost_starttime = jiffies + test_boost_interval * HZ; 4649 4650 firsterr = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "RCU_TORTURE", 4651 rcutorture_booster_init, 4652 rcutorture_booster_cleanup); 4653 rcutor_hp = firsterr; 4654 if (torture_init_error(firsterr)) 4655 goto unwind; 4656 } 4657 shutdown_jiffies = jiffies + shutdown_secs * HZ; 4658 firsterr = torture_shutdown_init(shutdown_secs, rcu_torture_cleanup); 4659 if (torture_init_error(firsterr)) 4660 goto unwind; 4661 firsterr = torture_onoff_init(onoff_holdoff * HZ, onoff_interval, 4662 rcutorture_sync); 4663 if (torture_init_error(firsterr)) 4664 goto unwind; 4665 firsterr = rcu_torture_stall_init(); 4666 if (torture_init_error(firsterr)) 4667 goto unwind; 4668 firsterr = rcu_torture_fwd_prog_init(); 4669 if (torture_init_error(firsterr)) 4670 goto unwind; 4671 firsterr = rcu_torture_barrier_init(); 4672 if (torture_init_error(firsterr)) 4673 goto unwind; 4674 firsterr = rcu_torture_read_exit_init(); 4675 if (torture_init_error(firsterr)) 4676 goto unwind; 4677 if (preempt_duration > 0) { 4678 firsterr = torture_create_kthread(rcu_torture_preempt, NULL, preempt_task); 4679 if (torture_init_error(firsterr)) 4680 goto unwind; 4681 } 4682 if (object_debug) 4683 rcu_test_debug_objects(); 4684 4685 if (cur_ops->gp_slow_register && !WARN_ON_ONCE(!cur_ops->gp_slow_unregister)) 4686 cur_ops->gp_slow_register(&rcu_fwd_cb_nodelay); 4687 4688 if (gpwrap_lag && cur_ops->set_gpwrap_lag) { 4689 firsterr = rcu_gpwrap_lag_init(); 4690 if (torture_init_error(firsterr)) 4691 goto unwind; 4692 } 4693 4694 torture_init_end(); 4695 return 0; 4696 4697 unwind: 4698 torture_init_end(); 4699 rcu_torture_cleanup(); 4700 if (shutdown_secs) { 4701 WARN_ON(!IS_MODULE(CONFIG_RCU_TORTURE_TEST)); 4702 kernel_power_off(); 4703 } 4704 return firsterr; 4705 } 4706 4707 module_init(rcu_torture_init); 4708 module_exit(rcu_torture_cleanup); 4709