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(&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, 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 unsigned long flags; 846 bool lockit = jiffies & 0x1; 847 848 if (lockit) 849 raw_spin_lock_irqsave(¤t->pi_lock, flags); 850 call_srcu(srcu_ctlp, &rp->rtort_rcu, rcu_torture_cb); 851 if (lockit) 852 raw_spin_unlock_irqrestore(¤t->pi_lock, flags); 853 } 854 855 static void srcu_torture_synchronize(void) 856 { 857 synchronize_srcu(srcu_ctlp); 858 } 859 860 static unsigned long srcu_torture_get_gp_state(void) 861 { 862 return get_state_synchronize_srcu(srcu_ctlp); 863 } 864 865 static unsigned long srcu_torture_start_gp_poll(void) 866 { 867 return start_poll_synchronize_srcu(srcu_ctlp); 868 } 869 870 static bool srcu_torture_poll_gp_state(unsigned long oldstate) 871 { 872 return poll_state_synchronize_srcu(srcu_ctlp, oldstate); 873 } 874 875 static void srcu_torture_call(struct rcu_head *head, 876 rcu_callback_t func) 877 { 878 call_srcu(srcu_ctlp, head, func); 879 } 880 881 static void srcu_torture_barrier(void) 882 { 883 srcu_barrier(srcu_ctlp); 884 } 885 886 static void srcu_torture_stats(void) 887 { 888 srcu_torture_stats_print(srcu_ctlp, torture_type, TORTURE_FLAG); 889 } 890 891 static void srcu_torture_synchronize_expedited(void) 892 { 893 synchronize_srcu_expedited(srcu_ctlp); 894 } 895 896 static void srcu_torture_expedite_current(void) 897 { 898 srcu_expedite_current(srcu_ctlp); 899 } 900 901 static struct rcu_torture_ops srcu_ops = { 902 .ttype = SRCU_FLAVOR, 903 .init = srcu_torture_init, 904 .readlock = srcu_torture_read_lock, 905 .read_delay = srcu_read_delay, 906 .readunlock = srcu_torture_read_unlock, 907 .down_read = srcu_torture_down_read, 908 .up_read = srcu_torture_up_read, 909 .readlock_held = torture_srcu_read_lock_held, 910 .get_gp_seq = srcu_torture_completed, 911 .gp_diff = rcu_seq_diff, 912 .deferred_free = srcu_torture_deferred_free, 913 .sync = srcu_torture_synchronize, 914 .exp_sync = srcu_torture_synchronize_expedited, 915 .exp_current = srcu_torture_expedite_current, 916 .same_gp_state = same_state_synchronize_srcu, 917 .get_comp_state = get_completed_synchronize_srcu, 918 .get_gp_state = srcu_torture_get_gp_state, 919 .start_gp_poll = srcu_torture_start_gp_poll, 920 .poll_gp_state = srcu_torture_poll_gp_state, 921 .poll_active = NUM_ACTIVE_SRCU_POLL_OLDSTATE, 922 .call = srcu_torture_call, 923 .cb_barrier = srcu_torture_barrier, 924 .stats = srcu_torture_stats, 925 .get_gp_data = srcu_get_gp_data, 926 .cbflood_max = 50000, 927 .irq_capable = 1, 928 .no_pi_lock = IS_ENABLED(CONFIG_TINY_SRCU), 929 .debug_objects = 1, 930 .have_up_down = IS_ENABLED(CONFIG_TINY_SRCU) 931 ? 0 : SRCU_READ_FLAVOR_NORMAL | SRCU_READ_FLAVOR_FAST_UPDOWN, 932 .name = "srcu" 933 }; 934 935 static void srcud_torture_init(void) 936 { 937 rcu_sync_torture_init(); 938 if (!reader_flavor || (reader_flavor & SRCU_READ_FLAVOR_NORMAL)) { 939 WARN_ON(init_srcu_struct(&srcu_ctld)); 940 VERBOSE_TOROUT_STRING("srcud_torture_init normal SRCU"); 941 } else if (reader_flavor & SRCU_READ_FLAVOR_NMI) { 942 WARN_ON(init_srcu_struct(&srcu_ctld)); 943 VERBOSE_TOROUT_STRING("srcud_torture_init NMI-safe SRCU"); 944 } else if (reader_flavor & SRCU_READ_FLAVOR_FAST) { 945 WARN_ON(init_srcu_struct_fast(&srcu_ctld)); 946 VERBOSE_TOROUT_STRING("srcud_torture_init fast SRCU"); 947 } else if (reader_flavor & SRCU_READ_FLAVOR_FAST_UPDOWN) { 948 WARN_ON(init_srcu_struct_fast_updown(&srcu_ctld)); 949 VERBOSE_TOROUT_STRING("srcud_torture_init fast-up/down SRCU"); 950 } else { 951 WARN_ON(init_srcu_struct(&srcu_ctld)); 952 } 953 srcu_ctlp = &srcu_ctld; 954 } 955 956 static void srcu_torture_cleanup(void) 957 { 958 cleanup_srcu_struct(&srcu_ctld); 959 srcu_ctlp = &srcu_ctl; /* In case of a later rcutorture run. */ 960 } 961 962 /* As above, but dynamically allocated. */ 963 static struct rcu_torture_ops srcud_ops = { 964 .ttype = SRCU_FLAVOR, 965 .init = srcud_torture_init, 966 .cleanup = srcu_torture_cleanup, 967 .readlock = srcu_torture_read_lock, 968 .read_delay = srcu_read_delay, 969 .readunlock = srcu_torture_read_unlock, 970 .readlock_held = torture_srcu_read_lock_held, 971 .down_read = srcu_torture_down_read, 972 .up_read = srcu_torture_up_read, 973 .get_gp_seq = srcu_torture_completed, 974 .gp_diff = rcu_seq_diff, 975 .deferred_free = srcu_torture_deferred_free, 976 .sync = srcu_torture_synchronize, 977 .exp_sync = srcu_torture_synchronize_expedited, 978 .exp_current = srcu_torture_expedite_current, 979 .same_gp_state = same_state_synchronize_srcu, 980 .get_comp_state = get_completed_synchronize_srcu, 981 .get_gp_state = srcu_torture_get_gp_state, 982 .start_gp_poll = srcu_torture_start_gp_poll, 983 .poll_gp_state = srcu_torture_poll_gp_state, 984 .poll_active = NUM_ACTIVE_SRCU_POLL_OLDSTATE, 985 .call = srcu_torture_call, 986 .cb_barrier = srcu_torture_barrier, 987 .stats = srcu_torture_stats, 988 .get_gp_data = srcu_get_gp_data, 989 .cbflood_max = 50000, 990 .irq_capable = 1, 991 .no_pi_lock = IS_ENABLED(CONFIG_TINY_SRCU), 992 .debug_objects = 1, 993 .have_up_down = IS_ENABLED(CONFIG_TINY_SRCU) 994 ? 0 : SRCU_READ_FLAVOR_NORMAL | SRCU_READ_FLAVOR_FAST_UPDOWN, 995 .name = "srcud" 996 }; 997 998 /* As above, but broken due to inappropriate reader extension. */ 999 static struct rcu_torture_ops busted_srcud_ops = { 1000 .ttype = SRCU_FLAVOR, 1001 .init = srcu_torture_init, 1002 .cleanup = srcu_torture_cleanup, 1003 .readlock = srcu_torture_read_lock, 1004 .read_delay = rcu_read_delay, 1005 .readunlock = srcu_torture_read_unlock, 1006 .readlock_held = torture_srcu_read_lock_held, 1007 .get_gp_seq = srcu_torture_completed, 1008 .deferred_free = srcu_torture_deferred_free, 1009 .sync = srcu_torture_synchronize, 1010 .exp_sync = srcu_torture_synchronize_expedited, 1011 .call = srcu_torture_call, 1012 .cb_barrier = srcu_torture_barrier, 1013 .stats = srcu_torture_stats, 1014 .irq_capable = 1, 1015 .no_pi_lock = IS_ENABLED(CONFIG_TINY_SRCU), 1016 .extendables = RCUTORTURE_MAX_EXTEND, 1017 .name = "busted_srcud" 1018 }; 1019 1020 /* 1021 * Definitions for trivial CONFIG_PREEMPT=n-only torture testing. 1022 * This implementation does not work well with CPU hotplug nor 1023 * with rcutorture's shuffling. 1024 */ 1025 1026 static void synchronize_rcu_trivial(void) 1027 { 1028 int cpu; 1029 1030 for_each_online_cpu(cpu) { 1031 torture_sched_setaffinity(current->pid, cpumask_of(cpu), true); 1032 WARN_ON_ONCE(raw_smp_processor_id() != cpu); 1033 } 1034 } 1035 1036 static void rcu_sync_torture_init_trivial(void) 1037 { 1038 rcu_sync_torture_init(); 1039 // if (onoff_interval || shuffle_interval) { 1040 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)) { 1041 onoff_interval = 0; 1042 shuffle_interval = 0; 1043 } 1044 } 1045 1046 static int rcu_torture_read_lock_trivial(void) 1047 { 1048 preempt_disable(); 1049 return 0; 1050 } 1051 1052 static void rcu_torture_read_unlock_trivial(int idx) 1053 { 1054 preempt_enable(); 1055 } 1056 1057 static struct rcu_torture_ops trivial_ops = { 1058 .ttype = RCU_TRIVIAL_FLAVOR, 1059 .init = rcu_sync_torture_init_trivial, 1060 .readlock = rcu_torture_read_lock_trivial, 1061 .read_delay = rcu_read_delay, /* just reuse rcu's version. */ 1062 .readunlock = rcu_torture_read_unlock_trivial, 1063 .readlock_held = torture_readlock_not_held, 1064 .get_gp_seq = rcu_no_completed, 1065 .sync = synchronize_rcu_trivial, 1066 .exp_sync = synchronize_rcu_trivial, 1067 .irq_capable = 1, 1068 .name = "trivial" 1069 }; 1070 1071 #ifdef CONFIG_TRIVIAL_PREEMPT_RCU 1072 1073 /* 1074 * Definitions for trivial CONFIG_PREEMPT=y torture testing. This 1075 * implementation does not work well with large numbers of tasks or with 1076 * long-term preemption. Either or both get you RCU CPU stall warnings. 1077 */ 1078 1079 static void rcu_sync_torture_init_trivial_preempt(void) 1080 { 1081 rcu_sync_torture_init(); 1082 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)) { 1083 onoff_interval = 0; 1084 shuffle_interval = 0; 1085 } 1086 } 1087 1088 static int rcu_torture_read_lock_trivial_preempt(void) 1089 { 1090 struct task_struct *t = current; 1091 1092 WRITE_ONCE(t->rcu_trivial_preempt_nesting, t->rcu_trivial_preempt_nesting + 1); 1093 smp_mb(); 1094 return 0; 1095 } 1096 1097 static void rcu_torture_read_unlock_trivial_preempt(int idx) 1098 { 1099 struct task_struct *t = current; 1100 1101 smp_store_release(&t->rcu_trivial_preempt_nesting, t->rcu_trivial_preempt_nesting - 1); 1102 } 1103 1104 static struct rcu_torture_ops trivial_preempt_ops = { 1105 .ttype = RCU_TRIVIAL_FLAVOR, 1106 .init = rcu_sync_torture_init_trivial_preempt, 1107 .readlock = rcu_torture_read_lock_trivial_preempt, 1108 .read_delay = rcu_read_delay, // just reuse rcu's version. 1109 .readunlock = rcu_torture_read_unlock_trivial_preempt, 1110 .readlock_held = torture_readlock_not_held, 1111 .get_gp_seq = rcu_no_completed, 1112 .sync = synchronize_rcu_trivial_preempt, 1113 .exp_sync = synchronize_rcu_trivial_preempt, 1114 .irq_capable = 0, // In theory it should be, but let's keep it trivial. 1115 .name = "trivial-preempt" 1116 }; 1117 1118 #define TRIVIAL_PREEMPT_OPS &trivial_preempt_ops, 1119 1120 #else // #ifdef CONFIG_TRIVIAL_PREEMPT_RCU 1121 1122 #define TRIVIAL_PREEMPT_OPS 1123 1124 #endif // #else // #ifdef CONFIG_TRIVIAL_PREEMPT_RCU 1125 1126 #ifdef CONFIG_TASKS_RCU 1127 1128 /* 1129 * Definitions for RCU-tasks torture testing. 1130 */ 1131 1132 static int tasks_torture_read_lock(void) 1133 { 1134 return 0; 1135 } 1136 1137 static void tasks_torture_read_unlock(int idx) 1138 { 1139 } 1140 1141 static void rcu_tasks_torture_deferred_free(struct rcu_torture *p) 1142 { 1143 call_rcu_tasks(&p->rtort_rcu, rcu_torture_cb); 1144 } 1145 1146 static void synchronize_rcu_mult_test(void) 1147 { 1148 synchronize_rcu_mult(call_rcu_tasks, call_rcu); 1149 } 1150 1151 static struct rcu_torture_ops tasks_ops = { 1152 .ttype = RCU_TASKS_FLAVOR, 1153 .init = rcu_sync_torture_init, 1154 .readlock = tasks_torture_read_lock, 1155 .read_delay = rcu_read_delay, /* just reuse rcu's version. */ 1156 .readunlock = tasks_torture_read_unlock, 1157 .get_gp_seq = rcu_no_completed, 1158 .deferred_free = rcu_tasks_torture_deferred_free, 1159 .sync = synchronize_rcu_tasks, 1160 .exp_sync = synchronize_rcu_mult_test, 1161 .call = call_rcu_tasks, 1162 .cb_barrier = rcu_barrier_tasks, 1163 .gp_kthread_dbg = show_rcu_tasks_classic_gp_kthread, 1164 .get_gp_data = rcu_tasks_get_gp_data, 1165 .irq_capable = 1, 1166 .slow_gps = 1, 1167 .name = "tasks" 1168 }; 1169 1170 #define TASKS_OPS &tasks_ops, 1171 1172 #else // #ifdef CONFIG_TASKS_RCU 1173 1174 #define TASKS_OPS 1175 1176 #endif // #else #ifdef CONFIG_TASKS_RCU 1177 1178 1179 #ifdef CONFIG_TASKS_RUDE_RCU 1180 1181 /* 1182 * Definitions for rude RCU-tasks torture testing. 1183 */ 1184 1185 static struct rcu_torture_ops tasks_rude_ops = { 1186 .ttype = RCU_TASKS_RUDE_FLAVOR, 1187 .init = rcu_sync_torture_init, 1188 .readlock = rcu_torture_read_lock_trivial, 1189 .read_delay = rcu_read_delay, /* just reuse rcu's version. */ 1190 .readunlock = rcu_torture_read_unlock_trivial, 1191 .get_gp_seq = rcu_no_completed, 1192 .sync = synchronize_rcu_tasks_rude, 1193 .exp_sync = synchronize_rcu_tasks_rude, 1194 .gp_kthread_dbg = show_rcu_tasks_rude_gp_kthread, 1195 .get_gp_data = rcu_tasks_rude_get_gp_data, 1196 .cbflood_max = 50000, 1197 .irq_capable = 1, 1198 .name = "tasks-rude" 1199 }; 1200 1201 #define TASKS_RUDE_OPS &tasks_rude_ops, 1202 1203 #else // #ifdef CONFIG_TASKS_RUDE_RCU 1204 1205 #define TASKS_RUDE_OPS 1206 1207 #endif // #else #ifdef CONFIG_TASKS_RUDE_RCU 1208 1209 1210 #ifdef CONFIG_TASKS_TRACE_RCU 1211 1212 /* 1213 * Definitions for tracing RCU-tasks torture testing. 1214 */ 1215 1216 static int tasks_tracing_torture_read_lock(void) 1217 { 1218 rcu_read_lock_trace(); 1219 return 0; 1220 } 1221 1222 static void tasks_tracing_torture_read_unlock(int idx) 1223 { 1224 rcu_read_unlock_trace(); 1225 } 1226 1227 static void rcu_tasks_tracing_torture_deferred_free(struct rcu_torture *p) 1228 { 1229 call_rcu_tasks_trace(&p->rtort_rcu, rcu_torture_cb); 1230 } 1231 1232 static struct rcu_torture_ops tasks_tracing_ops = { 1233 .ttype = RCU_TASKS_TRACING_FLAVOR, 1234 .init = rcu_sync_torture_init, 1235 .readlock = tasks_tracing_torture_read_lock, 1236 .read_delay = srcu_read_delay, /* just reuse srcu's version. */ 1237 .readunlock = tasks_tracing_torture_read_unlock, 1238 .readlock_held = rcu_read_lock_trace_held, 1239 .get_gp_seq = rcu_no_completed, 1240 .deferred_free = rcu_tasks_tracing_torture_deferred_free, 1241 .sync = synchronize_rcu_tasks_trace, 1242 .exp_sync = synchronize_rcu_tasks_trace, 1243 .exp_current = rcu_tasks_trace_expedite_current, 1244 .call = call_rcu_tasks_trace, 1245 .cb_barrier = rcu_barrier_tasks_trace, 1246 .cbflood_max = 50000, 1247 .irq_capable = 1, 1248 .slow_gps = 1, 1249 .name = "tasks-tracing" 1250 }; 1251 1252 #define TASKS_TRACING_OPS &tasks_tracing_ops, 1253 1254 #else // #ifdef CONFIG_TASKS_TRACE_RCU 1255 1256 #define TASKS_TRACING_OPS 1257 1258 #endif // #else #ifdef CONFIG_TASKS_TRACE_RCU 1259 1260 1261 static unsigned long rcutorture_seq_diff(unsigned long new, unsigned long old) 1262 { 1263 if (!cur_ops->gp_diff) 1264 return new - old; 1265 return cur_ops->gp_diff(new, old); 1266 } 1267 1268 /* 1269 * RCU torture priority-boost testing. Runs one real-time thread per 1270 * CPU for moderate bursts, repeatedly starting grace periods and waiting 1271 * for them to complete. If a given grace period takes too long, we assume 1272 * that priority inversion has occurred. 1273 */ 1274 1275 static int old_rt_runtime = -1; 1276 1277 static void rcu_torture_disable_rt_throttle(void) 1278 { 1279 /* 1280 * Disable RT throttling so that rcutorture's boost threads don't get 1281 * throttled. Only possible if rcutorture is built-in otherwise the 1282 * user should manually do this by setting the sched_rt_period_us and 1283 * sched_rt_runtime sysctls. 1284 */ 1285 if (!IS_BUILTIN(CONFIG_RCU_TORTURE_TEST) || old_rt_runtime != -1) 1286 return; 1287 1288 old_rt_runtime = sysctl_sched_rt_runtime; 1289 sysctl_sched_rt_runtime = -1; 1290 } 1291 1292 static void rcu_torture_enable_rt_throttle(void) 1293 { 1294 if (!IS_BUILTIN(CONFIG_RCU_TORTURE_TEST) || old_rt_runtime == -1) 1295 return; 1296 1297 sysctl_sched_rt_runtime = old_rt_runtime; 1298 old_rt_runtime = -1; 1299 } 1300 1301 static bool rcu_torture_boost_failed(unsigned long gp_state, unsigned long *start) 1302 { 1303 int cpu; 1304 static int dbg_done; 1305 unsigned long end = jiffies; 1306 bool gp_done; 1307 unsigned long j; 1308 static unsigned long last_persist; 1309 unsigned long lp; 1310 unsigned long mininterval = test_boost_duration * HZ - HZ / 2; 1311 1312 if (end - *start > mininterval) { 1313 // Recheck after checking time to avoid false positives. 1314 smp_mb(); // Time check before grace-period check. 1315 if (cur_ops->poll_gp_state(gp_state)) 1316 return false; // passed, though perhaps just barely 1317 if (cur_ops->check_boost_failed && !cur_ops->check_boost_failed(gp_state, &cpu)) { 1318 // At most one persisted message per boost test. 1319 j = jiffies; 1320 lp = READ_ONCE(last_persist); 1321 if (time_after(j, lp + mininterval) && 1322 cmpxchg(&last_persist, lp, j) == lp) { 1323 if (cpu < 0) 1324 pr_info("Boost inversion persisted: QS from all CPUs\n"); 1325 else 1326 pr_info("Boost inversion persisted: No QS from CPU %d\n", cpu); 1327 } 1328 return false; // passed on a technicality 1329 } 1330 VERBOSE_TOROUT_STRING("rcu_torture_boost boosting failed"); 1331 n_rcu_torture_boost_failure++; 1332 if (!xchg(&dbg_done, 1) && cur_ops->gp_kthread_dbg) { 1333 pr_info("Boost inversion thread ->rt_priority %u gp_state %lu jiffies %lu\n", 1334 current->rt_priority, gp_state, end - *start); 1335 cur_ops->gp_kthread_dbg(); 1336 // Recheck after print to flag grace period ending during splat. 1337 gp_done = cur_ops->poll_gp_state(gp_state); 1338 pr_info("Boost inversion: GP %lu %s.\n", gp_state, 1339 gp_done ? "ended already" : "still pending"); 1340 1341 } 1342 1343 return true; // failed 1344 } else if (cur_ops->check_boost_failed && !cur_ops->check_boost_failed(gp_state, NULL)) { 1345 *start = jiffies; 1346 } 1347 1348 return false; // passed 1349 } 1350 1351 static int rcu_torture_boost(void *arg) 1352 { 1353 unsigned long endtime; 1354 unsigned long gp_state; 1355 unsigned long gp_state_time; 1356 unsigned long oldstarttime; 1357 unsigned long booststarttime = get_torture_init_jiffies() + test_boost_holdoff * HZ; 1358 1359 if (test_boost_holdoff <= 0 || time_after(jiffies, booststarttime)) { 1360 VERBOSE_TOROUT_STRING("rcu_torture_boost started"); 1361 } else { 1362 VERBOSE_TOROUT_STRING("rcu_torture_boost started holdoff period"); 1363 while (time_before(jiffies, booststarttime)) { 1364 schedule_timeout_idle(HZ); 1365 if (kthread_should_stop()) 1366 goto cleanup; 1367 } 1368 VERBOSE_TOROUT_STRING("rcu_torture_boost finished holdoff period"); 1369 } 1370 1371 /* Set real-time priority. */ 1372 sched_set_fifo_low(current); 1373 1374 /* Each pass through the following loop does one boost-test cycle. */ 1375 do { 1376 bool failed = false; // Test failed already in this test interval 1377 bool gp_initiated = false; 1378 1379 if (kthread_should_stop()) 1380 goto checkwait; 1381 1382 /* Wait for the next test interval. */ 1383 oldstarttime = READ_ONCE(boost_starttime); 1384 while (time_before(jiffies, oldstarttime)) { 1385 schedule_timeout_interruptible(oldstarttime - jiffies); 1386 if (stutter_wait("rcu_torture_boost")) 1387 sched_set_fifo_low(current); 1388 if (torture_must_stop()) 1389 goto checkwait; 1390 } 1391 1392 // Do one boost-test interval. 1393 endtime = oldstarttime + test_boost_duration * HZ; 1394 while (time_before(jiffies, endtime)) { 1395 // Has current GP gone too long? 1396 if (gp_initiated && !failed && !cur_ops->poll_gp_state(gp_state)) 1397 failed = rcu_torture_boost_failed(gp_state, &gp_state_time); 1398 // If we don't have a grace period in flight, start one. 1399 if (!gp_initiated || cur_ops->poll_gp_state(gp_state)) { 1400 gp_state = cur_ops->start_gp_poll(); 1401 gp_initiated = true; 1402 gp_state_time = jiffies; 1403 } 1404 if (stutter_wait("rcu_torture_boost")) { 1405 sched_set_fifo_low(current); 1406 // If the grace period already ended, 1407 // we don't know when that happened, so 1408 // start over. 1409 if (cur_ops->poll_gp_state(gp_state)) 1410 gp_initiated = false; 1411 } 1412 if (torture_must_stop()) 1413 goto checkwait; 1414 } 1415 1416 // In case the grace period extended beyond the end of the loop. 1417 if (gp_initiated && !failed && !cur_ops->poll_gp_state(gp_state)) 1418 rcu_torture_boost_failed(gp_state, &gp_state_time); 1419 1420 /* 1421 * Set the start time of the next test interval. 1422 * Yes, this is vulnerable to long delays, but such 1423 * delays simply cause a false negative for the next 1424 * interval. Besides, we are running at RT priority, 1425 * so delays should be relatively rare. 1426 */ 1427 while (oldstarttime == READ_ONCE(boost_starttime) && !kthread_should_stop()) { 1428 if (mutex_trylock(&boost_mutex)) { 1429 if (oldstarttime == boost_starttime) { 1430 WRITE_ONCE(boost_starttime, 1431 jiffies + test_boost_interval * HZ); 1432 n_rcu_torture_boosts++; 1433 } 1434 mutex_unlock(&boost_mutex); 1435 break; 1436 } 1437 schedule_timeout_uninterruptible(HZ / 20); 1438 } 1439 1440 /* Go do the stutter. */ 1441 checkwait: if (stutter_wait("rcu_torture_boost")) 1442 sched_set_fifo_low(current); 1443 } while (!torture_must_stop()); 1444 1445 cleanup: 1446 /* Clean up and exit. */ 1447 while (!kthread_should_stop()) { 1448 torture_shutdown_absorb("rcu_torture_boost"); 1449 schedule_timeout_uninterruptible(HZ / 20); 1450 } 1451 torture_kthread_stopping("rcu_torture_boost"); 1452 return 0; 1453 } 1454 1455 /* 1456 * RCU torture force-quiescent-state kthread. Repeatedly induces 1457 * bursts of calls to force_quiescent_state(), increasing the probability 1458 * of occurrence of some important types of race conditions. 1459 */ 1460 static int 1461 rcu_torture_fqs(void *arg) 1462 { 1463 unsigned long fqs_resume_time; 1464 int fqs_burst_remaining; 1465 int oldnice = task_nice(current); 1466 1467 VERBOSE_TOROUT_STRING("rcu_torture_fqs task started"); 1468 do { 1469 fqs_resume_time = jiffies + fqs_stutter * HZ; 1470 while (time_before(jiffies, fqs_resume_time) && 1471 !kthread_should_stop()) { 1472 schedule_timeout_interruptible(HZ / 20); 1473 } 1474 fqs_burst_remaining = fqs_duration; 1475 while (fqs_burst_remaining > 0 && 1476 !kthread_should_stop()) { 1477 cur_ops->fqs(); 1478 udelay(fqs_holdoff); 1479 fqs_burst_remaining -= fqs_holdoff; 1480 } 1481 if (stutter_wait("rcu_torture_fqs")) 1482 sched_set_normal(current, oldnice); 1483 } while (!torture_must_stop()); 1484 torture_kthread_stopping("rcu_torture_fqs"); 1485 return 0; 1486 } 1487 1488 // Used by writers to randomly choose from the available grace-period primitives. 1489 static int synctype[ARRAY_SIZE(rcu_torture_writer_state_names)] = { }; 1490 static int nsynctypes; 1491 1492 /* 1493 * Determine which grace-period primitives are available. 1494 */ 1495 static void rcu_torture_write_types(void) 1496 { 1497 bool gp_cond1 = gp_cond, gp_cond_exp1 = gp_cond_exp, gp_cond_full1 = gp_cond_full; 1498 bool gp_cond_exp_full1 = gp_cond_exp_full, gp_exp1 = gp_exp, gp_poll_exp1 = gp_poll_exp; 1499 bool gp_poll_exp_full1 = gp_poll_exp_full, gp_normal1 = gp_normal, gp_poll1 = gp_poll; 1500 bool gp_poll_full1 = gp_poll_full, gp_sync1 = gp_sync; 1501 1502 /* Initialize synctype[] array. If none set, take default. */ 1503 if (!gp_cond1 && 1504 !gp_cond_exp1 && 1505 !gp_cond_full1 && 1506 !gp_cond_exp_full1 && 1507 !gp_exp1 && 1508 !gp_poll_exp1 && 1509 !gp_poll_exp_full1 && 1510 !gp_normal1 && 1511 !gp_poll1 && 1512 !gp_poll_full1 && 1513 !gp_sync1) { 1514 gp_cond1 = true; 1515 gp_cond_exp1 = true; 1516 gp_cond_full1 = true; 1517 gp_cond_exp_full1 = true; 1518 gp_exp1 = true; 1519 gp_poll_exp1 = true; 1520 gp_poll_exp_full1 = true; 1521 gp_normal1 = true; 1522 gp_poll1 = true; 1523 gp_poll_full1 = true; 1524 gp_sync1 = true; 1525 } 1526 if (gp_cond1 && cur_ops->get_gp_state && cur_ops->cond_sync) { 1527 synctype[nsynctypes++] = RTWS_COND_GET; 1528 pr_info("%s: Testing conditional GPs.\n", __func__); 1529 } else if (gp_cond && (!cur_ops->get_gp_state || !cur_ops->cond_sync)) { 1530 pr_alert("%s: gp_cond without primitives.\n", __func__); 1531 } 1532 if (gp_cond_exp1 && cur_ops->get_gp_state_exp && cur_ops->cond_sync_exp) { 1533 synctype[nsynctypes++] = RTWS_COND_GET_EXP; 1534 pr_info("%s: Testing conditional expedited GPs.\n", __func__); 1535 } else if (gp_cond_exp && (!cur_ops->get_gp_state_exp || !cur_ops->cond_sync_exp)) { 1536 pr_alert("%s: gp_cond_exp without primitives.\n", __func__); 1537 } 1538 if (gp_cond_full1 && cur_ops->get_gp_state && cur_ops->cond_sync_full) { 1539 synctype[nsynctypes++] = RTWS_COND_GET_FULL; 1540 pr_info("%s: Testing conditional full-state GPs.\n", __func__); 1541 } else if (gp_cond_full && (!cur_ops->get_gp_state || !cur_ops->cond_sync_full)) { 1542 pr_alert("%s: gp_cond_full without primitives.\n", __func__); 1543 } 1544 if (gp_cond_exp_full1 && cur_ops->get_gp_state_exp && cur_ops->cond_sync_exp_full) { 1545 synctype[nsynctypes++] = RTWS_COND_GET_EXP_FULL; 1546 pr_info("%s: Testing conditional full-state expedited GPs.\n", __func__); 1547 } else if (gp_cond_exp_full && 1548 (!cur_ops->get_gp_state_exp || !cur_ops->cond_sync_exp_full)) { 1549 pr_alert("%s: gp_cond_exp_full without primitives.\n", __func__); 1550 } 1551 if (gp_exp1 && cur_ops->exp_sync) { 1552 synctype[nsynctypes++] = RTWS_EXP_SYNC; 1553 pr_info("%s: Testing expedited GPs.\n", __func__); 1554 } else if (gp_exp && !cur_ops->exp_sync) { 1555 pr_alert("%s: gp_exp without primitives.\n", __func__); 1556 } 1557 if (gp_normal1 && cur_ops->deferred_free) { 1558 synctype[nsynctypes++] = RTWS_DEF_FREE; 1559 pr_info("%s: Testing asynchronous GPs.\n", __func__); 1560 } else if (gp_normal && !cur_ops->deferred_free) { 1561 pr_alert("%s: gp_normal without primitives.\n", __func__); 1562 } 1563 if (gp_poll1 && cur_ops->get_comp_state && cur_ops->same_gp_state && 1564 cur_ops->start_gp_poll && cur_ops->poll_gp_state) { 1565 synctype[nsynctypes++] = RTWS_POLL_GET; 1566 pr_info("%s: Testing polling GPs.\n", __func__); 1567 } else if (gp_poll && (!cur_ops->start_gp_poll || !cur_ops->poll_gp_state)) { 1568 pr_alert("%s: gp_poll without primitives.\n", __func__); 1569 } 1570 if (gp_poll_full1 && cur_ops->get_comp_state_full && cur_ops->same_gp_state_full 1571 && cur_ops->start_gp_poll_full && cur_ops->poll_gp_state_full) { 1572 synctype[nsynctypes++] = RTWS_POLL_GET_FULL; 1573 pr_info("%s: Testing polling full-state GPs.\n", __func__); 1574 } else if (gp_poll_full && (!cur_ops->start_gp_poll_full || !cur_ops->poll_gp_state_full)) { 1575 pr_alert("%s: gp_poll_full without primitives.\n", __func__); 1576 } 1577 if (gp_poll_exp1 && cur_ops->start_gp_poll_exp && cur_ops->poll_gp_state_exp) { 1578 synctype[nsynctypes++] = RTWS_POLL_GET_EXP; 1579 pr_info("%s: Testing polling expedited GPs.\n", __func__); 1580 } else if (gp_poll_exp && (!cur_ops->start_gp_poll_exp || !cur_ops->poll_gp_state_exp)) { 1581 pr_alert("%s: gp_poll_exp without primitives.\n", __func__); 1582 } 1583 if (gp_poll_exp_full1 && cur_ops->start_gp_poll_exp_full && cur_ops->poll_gp_state_full) { 1584 synctype[nsynctypes++] = RTWS_POLL_GET_EXP_FULL; 1585 pr_info("%s: Testing polling full-state expedited GPs.\n", __func__); 1586 } else if (gp_poll_exp_full && 1587 (!cur_ops->start_gp_poll_exp_full || !cur_ops->poll_gp_state_full)) { 1588 pr_alert("%s: gp_poll_exp_full without primitives.\n", __func__); 1589 } 1590 if (gp_sync1 && cur_ops->sync) { 1591 synctype[nsynctypes++] = RTWS_SYNC; 1592 pr_info("%s: Testing normal GPs.\n", __func__); 1593 } else if (gp_sync && !cur_ops->sync) { 1594 pr_alert("%s: gp_sync without primitives.\n", __func__); 1595 } 1596 pr_alert("%s: Testing %d update types.\n", __func__, nsynctypes); 1597 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); 1598 } 1599 1600 /* 1601 * Do the specified rcu_torture_writer() synchronous grace period, 1602 * while also testing out the polled APIs. Note well that the single-CPU 1603 * grace-period optimizations must be accounted for. 1604 */ 1605 static void do_rtws_sync(struct torture_random_state *trsp, void (*sync)(void)) 1606 { 1607 unsigned long cookie; 1608 struct rcu_gp_oldstate cookie_full; 1609 bool dopoll; 1610 bool dopoll_full; 1611 unsigned long r = torture_random(trsp); 1612 1613 dopoll = cur_ops->get_gp_state && cur_ops->poll_gp_state && !(r & 0x300); 1614 dopoll_full = cur_ops->get_gp_state_full && cur_ops->poll_gp_state_full && !(r & 0xc00); 1615 if (dopoll || dopoll_full) 1616 cpus_read_lock(); 1617 if (dopoll) 1618 cookie = cur_ops->get_gp_state(); 1619 if (dopoll_full) 1620 cur_ops->get_gp_state_full(&cookie_full); 1621 if (cur_ops->poll_need_2gp && cur_ops->poll_need_2gp(dopoll, dopoll_full)) 1622 sync(); 1623 sync(); 1624 WARN_ONCE(dopoll && !cur_ops->poll_gp_state(cookie), 1625 "%s: Cookie check 3 failed %pS() online %*pbl.", 1626 __func__, sync, cpumask_pr_args(cpu_online_mask)); 1627 WARN_ONCE(dopoll_full && !cur_ops->poll_gp_state_full(&cookie_full), 1628 "%s: Cookie check 4 failed %pS() online %*pbl", 1629 __func__, sync, cpumask_pr_args(cpu_online_mask)); 1630 if (dopoll || dopoll_full) 1631 cpus_read_unlock(); 1632 } 1633 1634 /* 1635 * Do an rcu_barrier() to motivate lazy callbacks during a stutter 1636 * pause. Without this, we can get false-positives rtort_pipe_count 1637 * splats. 1638 */ 1639 static void rcu_torture_writer_work(struct work_struct *work) 1640 { 1641 if (cur_ops->cb_barrier) 1642 cur_ops->cb_barrier(); 1643 } 1644 1645 /* 1646 * RCU torture writer kthread. Repeatedly substitutes a new structure 1647 * for that pointed to by rcu_torture_current, freeing the old structure 1648 * after a series of grace periods (the "pipeline"). 1649 */ 1650 static int 1651 rcu_torture_writer(void *arg) 1652 { 1653 bool booting_still = false; 1654 bool can_expedite = !rcu_gp_is_expedited() && !rcu_gp_is_normal(); 1655 unsigned long cookie; 1656 struct rcu_gp_oldstate cookie_full; 1657 int expediting = 0; 1658 unsigned long gp_snap; 1659 unsigned long gp_snap1; 1660 struct rcu_gp_oldstate gp_snap_full; 1661 struct rcu_gp_oldstate gp_snap1_full; 1662 int i; 1663 int idx; 1664 unsigned long j; 1665 struct work_struct lazy_work; 1666 int oldnice = task_nice(current); 1667 struct rcu_gp_oldstate *rgo = NULL; 1668 int rgo_size = 0; 1669 struct rcu_torture *rp; 1670 struct rcu_torture *old_rp; 1671 static DEFINE_TORTURE_RANDOM(rand); 1672 unsigned long stallsdone = jiffies; 1673 bool stutter_waited; 1674 unsigned long *ulo = NULL; 1675 int ulo_size = 0; 1676 1677 // If a new stall test is added, this must be adjusted. 1678 if (stall_cpu_holdoff + stall_gp_kthread + stall_cpu) 1679 stallsdone += (stall_cpu_holdoff + stall_gp_kthread + stall_cpu + 60) * 1680 HZ * (stall_cpu_repeat + 1); 1681 VERBOSE_TOROUT_STRING("rcu_torture_writer task started"); 1682 if (!can_expedite) 1683 pr_alert("%s" TORTURE_FLAG 1684 " GP expediting controlled from boot/sysfs for %s.\n", 1685 torture_type, cur_ops->name); 1686 if (WARN_ONCE(nsynctypes == 0, 1687 "%s: No update-side primitives.\n", __func__)) { 1688 /* 1689 * No updates primitives, so don't try updating. 1690 * The resulting test won't be testing much, hence the 1691 * above WARN_ONCE(). 1692 */ 1693 rcu_torture_writer_state = RTWS_STOPPING; 1694 torture_kthread_stopping("rcu_torture_writer"); 1695 return 0; 1696 } 1697 if (cur_ops->poll_active > 0) { 1698 ulo = kcalloc(cur_ops->poll_active, sizeof(*ulo), GFP_KERNEL); 1699 if (!WARN_ON(!ulo)) 1700 ulo_size = cur_ops->poll_active; 1701 } 1702 if (cur_ops->poll_active_full > 0) { 1703 rgo = kzalloc_objs(*rgo, cur_ops->poll_active_full); 1704 if (!WARN_ON(!rgo)) 1705 rgo_size = cur_ops->poll_active_full; 1706 } 1707 1708 // If the system is still booting, let it finish. 1709 j = jiffies; 1710 while (!torture_must_stop() && !rcu_inkernel_boot_has_ended()) { 1711 booting_still = true; 1712 schedule_timeout_interruptible(HZ); 1713 } 1714 if (booting_still) 1715 pr_alert("%s" TORTURE_FLAG " Waited %lu jiffies for boot to complete.\n", 1716 torture_type, jiffies - j); 1717 1718 if (IS_ENABLED(CONFIG_RCU_LAZY)) 1719 INIT_WORK_ONSTACK(&lazy_work, rcu_torture_writer_work); 1720 1721 do { 1722 rcu_torture_writer_state = RTWS_FIXED_DELAY; 1723 torture_hrtimeout_us(500, 1000, &rand); 1724 rp = rcu_torture_alloc(); 1725 if (rp == NULL) 1726 continue; 1727 rp->rtort_pipe_count = 0; 1728 ASSERT_EXCLUSIVE_WRITER(rp->rtort_pipe_count); 1729 rcu_torture_writer_state = RTWS_DELAY; 1730 udelay(torture_random(&rand) & 0x3ff); 1731 rcu_torture_writer_state = RTWS_REPLACE; 1732 old_rp = rcu_dereference_check(rcu_torture_current, 1733 current == writer_task); 1734 rp->rtort_mbtest = 1; 1735 rcu_assign_pointer(rcu_torture_current, rp); 1736 smp_wmb(); /* Mods to old_rp must follow rcu_assign_pointer() */ 1737 if (old_rp) { 1738 i = old_rp->rtort_pipe_count; 1739 if (i > RCU_TORTURE_PIPE_LEN) 1740 i = RCU_TORTURE_PIPE_LEN; 1741 atomic_inc(&rcu_torture_wcount[i]); 1742 WRITE_ONCE(old_rp->rtort_pipe_count, 1743 old_rp->rtort_pipe_count + 1); 1744 ASSERT_EXCLUSIVE_WRITER(old_rp->rtort_pipe_count); 1745 1746 // Make sure readers block polled grace periods. 1747 if (cur_ops->get_gp_state && cur_ops->poll_gp_state) { 1748 idx = cur_ops->readlock(); 1749 cookie = cur_ops->get_gp_state(); 1750 WARN_ONCE(cur_ops->poll_gp_state(cookie), 1751 "%s: Cookie check 1 failed %s(%d) %lu->%lu\n", 1752 __func__, 1753 rcu_torture_writer_state_getname(), 1754 rcu_torture_writer_state, 1755 cookie, cur_ops->get_gp_state()); 1756 if (cur_ops->get_comp_state) { 1757 cookie = cur_ops->get_comp_state(); 1758 WARN_ON_ONCE(!cur_ops->poll_gp_state(cookie)); 1759 } 1760 cur_ops->readunlock(idx); 1761 } 1762 if (cur_ops->get_gp_state_full && cur_ops->poll_gp_state_full) { 1763 idx = cur_ops->readlock(); 1764 cur_ops->get_gp_state_full(&cookie_full); 1765 WARN_ONCE(cur_ops->poll_gp_state_full(&cookie_full), 1766 "%s: Cookie check 5 failed %s(%d) online %*pbl\n", 1767 __func__, 1768 rcu_torture_writer_state_getname(), 1769 rcu_torture_writer_state, 1770 cpumask_pr_args(cpu_online_mask)); 1771 if (cur_ops->get_comp_state_full) { 1772 cur_ops->get_comp_state_full(&cookie_full); 1773 WARN_ON_ONCE(!cur_ops->poll_gp_state_full(&cookie_full)); 1774 } 1775 cur_ops->readunlock(idx); 1776 } 1777 switch (synctype[torture_random(&rand) % nsynctypes]) { 1778 case RTWS_DEF_FREE: 1779 rcu_torture_writer_state = RTWS_DEF_FREE; 1780 cur_ops->deferred_free(old_rp); 1781 break; 1782 case RTWS_EXP_SYNC: 1783 rcu_torture_writer_state = RTWS_EXP_SYNC; 1784 do_rtws_sync(&rand, cur_ops->exp_sync); 1785 rcu_torture_pipe_update(old_rp); 1786 break; 1787 case RTWS_COND_GET: 1788 rcu_torture_writer_state = RTWS_COND_GET; 1789 gp_snap = cur_ops->get_gp_state(); 1790 torture_hrtimeout_us(torture_random(&rand) % gp_cond_wi, 1791 1000, &rand); 1792 rcu_torture_writer_state = RTWS_COND_SYNC; 1793 cur_ops->cond_sync(gp_snap); 1794 rcu_torture_pipe_update(old_rp); 1795 break; 1796 case RTWS_COND_GET_EXP: 1797 rcu_torture_writer_state = RTWS_COND_GET_EXP; 1798 gp_snap = cur_ops->get_gp_state_exp(); 1799 torture_hrtimeout_us(torture_random(&rand) % gp_cond_wi_exp, 1800 1000, &rand); 1801 rcu_torture_writer_state = RTWS_COND_SYNC_EXP; 1802 cur_ops->cond_sync_exp(gp_snap); 1803 rcu_torture_pipe_update(old_rp); 1804 break; 1805 case RTWS_COND_GET_FULL: 1806 rcu_torture_writer_state = RTWS_COND_GET_FULL; 1807 cur_ops->get_gp_state_full(&gp_snap_full); 1808 torture_hrtimeout_us(torture_random(&rand) % gp_cond_wi, 1809 1000, &rand); 1810 rcu_torture_writer_state = RTWS_COND_SYNC_FULL; 1811 cur_ops->cond_sync_full(&gp_snap_full); 1812 rcu_torture_pipe_update(old_rp); 1813 break; 1814 case RTWS_COND_GET_EXP_FULL: 1815 rcu_torture_writer_state = RTWS_COND_GET_EXP_FULL; 1816 cur_ops->get_gp_state_full(&gp_snap_full); 1817 torture_hrtimeout_us(torture_random(&rand) % gp_cond_wi_exp, 1818 1000, &rand); 1819 rcu_torture_writer_state = RTWS_COND_SYNC_EXP_FULL; 1820 cur_ops->cond_sync_exp_full(&gp_snap_full); 1821 rcu_torture_pipe_update(old_rp); 1822 break; 1823 case RTWS_POLL_GET: 1824 rcu_torture_writer_state = RTWS_POLL_GET; 1825 for (i = 0; i < ulo_size; i++) 1826 ulo[i] = cur_ops->get_comp_state(); 1827 gp_snap = cur_ops->start_gp_poll(); 1828 rcu_torture_writer_state = RTWS_POLL_WAIT; 1829 if (cur_ops->exp_current && !(torture_random(&rand) & 0xff)) 1830 cur_ops->exp_current(); 1831 while (!cur_ops->poll_gp_state(gp_snap)) { 1832 gp_snap1 = cur_ops->get_gp_state(); 1833 for (i = 0; i < ulo_size; i++) 1834 if (cur_ops->poll_gp_state(ulo[i]) || 1835 cur_ops->same_gp_state(ulo[i], gp_snap1)) { 1836 ulo[i] = gp_snap1; 1837 break; 1838 } 1839 WARN_ON_ONCE(ulo_size > 0 && i >= ulo_size); 1840 torture_hrtimeout_us(torture_random(&rand) % gp_poll_wi, 1841 1000, &rand); 1842 } 1843 rcu_torture_pipe_update(old_rp); 1844 break; 1845 case RTWS_POLL_GET_FULL: 1846 rcu_torture_writer_state = RTWS_POLL_GET_FULL; 1847 for (i = 0; i < rgo_size; i++) 1848 cur_ops->get_comp_state_full(&rgo[i]); 1849 cur_ops->start_gp_poll_full(&gp_snap_full); 1850 rcu_torture_writer_state = RTWS_POLL_WAIT_FULL; 1851 if (cur_ops->exp_current && !(torture_random(&rand) & 0xff)) 1852 cur_ops->exp_current(); 1853 while (!cur_ops->poll_gp_state_full(&gp_snap_full)) { 1854 cur_ops->get_gp_state_full(&gp_snap1_full); 1855 for (i = 0; i < rgo_size; i++) 1856 if (cur_ops->poll_gp_state_full(&rgo[i]) || 1857 cur_ops->same_gp_state_full(&rgo[i], 1858 &gp_snap1_full)) { 1859 rgo[i] = gp_snap1_full; 1860 break; 1861 } 1862 WARN_ON_ONCE(rgo_size > 0 && i >= rgo_size); 1863 torture_hrtimeout_us(torture_random(&rand) % gp_poll_wi, 1864 1000, &rand); 1865 } 1866 rcu_torture_pipe_update(old_rp); 1867 break; 1868 case RTWS_POLL_GET_EXP: 1869 rcu_torture_writer_state = RTWS_POLL_GET_EXP; 1870 gp_snap = cur_ops->start_gp_poll_exp(); 1871 rcu_torture_writer_state = RTWS_POLL_WAIT_EXP; 1872 while (!cur_ops->poll_gp_state_exp(gp_snap)) 1873 torture_hrtimeout_us(torture_random(&rand) % gp_poll_wi_exp, 1874 1000, &rand); 1875 rcu_torture_pipe_update(old_rp); 1876 break; 1877 case RTWS_POLL_GET_EXP_FULL: 1878 rcu_torture_writer_state = RTWS_POLL_GET_EXP_FULL; 1879 cur_ops->start_gp_poll_exp_full(&gp_snap_full); 1880 rcu_torture_writer_state = RTWS_POLL_WAIT_EXP_FULL; 1881 while (!cur_ops->poll_gp_state_full(&gp_snap_full)) 1882 torture_hrtimeout_us(torture_random(&rand) % gp_poll_wi_exp, 1883 1000, &rand); 1884 rcu_torture_pipe_update(old_rp); 1885 break; 1886 case RTWS_SYNC: 1887 rcu_torture_writer_state = RTWS_SYNC; 1888 do_rtws_sync(&rand, cur_ops->sync); 1889 rcu_torture_pipe_update(old_rp); 1890 break; 1891 default: 1892 WARN_ON_ONCE(1); 1893 break; 1894 } 1895 } 1896 WRITE_ONCE(rcu_torture_current_version, 1897 rcu_torture_current_version + 1); 1898 /* Cycle through nesting levels of rcu_expedite_gp() calls. */ 1899 if (can_expedite && 1900 !(torture_random(&rand) & 0xff & (!!expediting - 1))) { 1901 WARN_ON_ONCE(expediting == 0 && rcu_gp_is_expedited()); 1902 if (expediting >= 0) 1903 rcu_expedite_gp(); 1904 else 1905 rcu_unexpedite_gp(); 1906 if (++expediting > 3) 1907 expediting = -expediting; 1908 } else if (!can_expedite) { /* Disabled during boot, recheck. */ 1909 can_expedite = !rcu_gp_is_expedited() && 1910 !rcu_gp_is_normal(); 1911 } 1912 rcu_torture_writer_state = RTWS_STUTTER; 1913 if (IS_ENABLED(CONFIG_RCU_LAZY)) 1914 queue_work(system_percpu_wq, &lazy_work); 1915 stutter_waited = stutter_wait("rcu_torture_writer"); 1916 if (stutter_waited && 1917 !atomic_read(&rcu_fwd_cb_nodelay) && 1918 !cur_ops->slow_gps && 1919 !torture_must_stop() && 1920 time_after(jiffies, stallsdone)) 1921 for (i = 0; i < ARRAY_SIZE(rcu_tortures); i++) 1922 if (list_empty(&rcu_tortures[i].rtort_free) && 1923 rcu_access_pointer(rcu_torture_current) != &rcu_tortures[i]) { 1924 tracing_off(); 1925 if (cur_ops->gp_kthread_dbg) 1926 cur_ops->gp_kthread_dbg(); 1927 WARN(1, "%s: rtort_pipe_count: %d\n", __func__, rcu_tortures[i].rtort_pipe_count); 1928 rcu_ftrace_dump(DUMP_ALL); 1929 break; 1930 } 1931 if (stutter_waited) 1932 sched_set_normal(current, oldnice); 1933 } while (!torture_must_stop()); 1934 rcu_torture_current = NULL; // Let stats task know that we are done. 1935 /* Reset expediting back to unexpedited. */ 1936 if (expediting > 0) 1937 expediting = -expediting; 1938 while (can_expedite && expediting++ < 0) 1939 rcu_unexpedite_gp(); 1940 WARN_ON_ONCE(can_expedite && rcu_gp_is_expedited()); 1941 if (!can_expedite) 1942 pr_alert("%s" TORTURE_FLAG 1943 " Dynamic grace-period expediting was disabled.\n", 1944 torture_type); 1945 1946 if (IS_ENABLED(CONFIG_RCU_LAZY)) { 1947 cancel_work_sync(&lazy_work); 1948 destroy_work_on_stack(&lazy_work); 1949 } 1950 1951 kfree(ulo); 1952 kfree(rgo); 1953 rcu_torture_writer_state = RTWS_STOPPING; 1954 torture_kthread_stopping("rcu_torture_writer"); 1955 return 0; 1956 } 1957 1958 /* 1959 * RCU torture fake writer kthread. Repeatedly calls sync, with a random 1960 * delay between calls. 1961 */ 1962 static int 1963 rcu_torture_fakewriter(void *arg) 1964 { 1965 unsigned long gp_snap; 1966 struct rcu_gp_oldstate gp_snap_full; 1967 DEFINE_TORTURE_RANDOM(rand); 1968 1969 VERBOSE_TOROUT_STRING("rcu_torture_fakewriter task started"); 1970 set_user_nice(current, MAX_NICE); 1971 1972 if (WARN_ONCE(nsynctypes == 0, 1973 "%s: No update-side primitives.\n", __func__)) { 1974 /* 1975 * No updates primitives, so don't try updating. 1976 * The resulting test won't be testing much, hence the 1977 * above WARN_ONCE(). 1978 */ 1979 torture_kthread_stopping("rcu_torture_fakewriter"); 1980 return 0; 1981 } 1982 1983 do { 1984 torture_hrtimeout_jiffies(torture_random(&rand) % 10, &rand); 1985 if (cur_ops->cb_barrier != NULL && 1986 torture_random(&rand) % (nrealfakewriters * 8) == 0) { 1987 cur_ops->cb_barrier(); 1988 } else { 1989 switch (synctype[torture_random(&rand) % nsynctypes]) { 1990 case RTWS_DEF_FREE: 1991 break; 1992 case RTWS_EXP_SYNC: 1993 cur_ops->exp_sync(); 1994 break; 1995 case RTWS_COND_GET: 1996 gp_snap = cur_ops->get_gp_state(); 1997 torture_hrtimeout_jiffies(torture_random(&rand) % 16, &rand); 1998 cur_ops->cond_sync(gp_snap); 1999 break; 2000 case RTWS_COND_GET_EXP: 2001 gp_snap = cur_ops->get_gp_state_exp(); 2002 torture_hrtimeout_jiffies(torture_random(&rand) % 16, &rand); 2003 cur_ops->cond_sync_exp(gp_snap); 2004 break; 2005 case RTWS_COND_GET_FULL: 2006 cur_ops->get_gp_state_full(&gp_snap_full); 2007 torture_hrtimeout_jiffies(torture_random(&rand) % 16, &rand); 2008 cur_ops->cond_sync_full(&gp_snap_full); 2009 break; 2010 case RTWS_COND_GET_EXP_FULL: 2011 cur_ops->get_gp_state_full(&gp_snap_full); 2012 torture_hrtimeout_jiffies(torture_random(&rand) % 16, &rand); 2013 cur_ops->cond_sync_exp_full(&gp_snap_full); 2014 break; 2015 case RTWS_POLL_GET: 2016 if (cur_ops->start_poll_irqsoff) 2017 local_irq_disable(); 2018 gp_snap = cur_ops->start_gp_poll(); 2019 if (cur_ops->start_poll_irqsoff) 2020 local_irq_enable(); 2021 while (!cur_ops->poll_gp_state(gp_snap)) { 2022 torture_hrtimeout_jiffies(torture_random(&rand) % 16, 2023 &rand); 2024 } 2025 break; 2026 case RTWS_POLL_GET_FULL: 2027 if (cur_ops->start_poll_irqsoff) 2028 local_irq_disable(); 2029 cur_ops->start_gp_poll_full(&gp_snap_full); 2030 if (cur_ops->start_poll_irqsoff) 2031 local_irq_enable(); 2032 while (!cur_ops->poll_gp_state_full(&gp_snap_full)) { 2033 torture_hrtimeout_jiffies(torture_random(&rand) % 16, 2034 &rand); 2035 } 2036 break; 2037 case RTWS_POLL_GET_EXP: 2038 gp_snap = cur_ops->start_gp_poll_exp(); 2039 while (!cur_ops->poll_gp_state_exp(gp_snap)) { 2040 torture_hrtimeout_jiffies(torture_random(&rand) % 16, 2041 &rand); 2042 } 2043 break; 2044 case RTWS_POLL_GET_EXP_FULL: 2045 cur_ops->start_gp_poll_exp_full(&gp_snap_full); 2046 while (!cur_ops->poll_gp_state_full(&gp_snap_full)) { 2047 torture_hrtimeout_jiffies(torture_random(&rand) % 16, 2048 &rand); 2049 } 2050 break; 2051 case RTWS_SYNC: 2052 cur_ops->sync(); 2053 break; 2054 default: 2055 WARN_ON_ONCE(1); 2056 break; 2057 } 2058 } 2059 stutter_wait("rcu_torture_fakewriter"); 2060 } while (!torture_must_stop()); 2061 2062 torture_kthread_stopping("rcu_torture_fakewriter"); 2063 return 0; 2064 } 2065 2066 static void rcu_torture_timer_cb(struct rcu_head *rhp) 2067 { 2068 kfree(rhp); 2069 } 2070 2071 // Set up and carry out testing of RCU's global memory ordering 2072 static void rcu_torture_reader_do_mbchk(long myid, struct rcu_torture *rtp, 2073 struct torture_random_state *trsp) 2074 { 2075 unsigned long loops; 2076 int noc = torture_num_online_cpus(); 2077 int rdrchked; 2078 int rdrchker; 2079 struct rcu_torture_reader_check *rtrcp; // Me. 2080 struct rcu_torture_reader_check *rtrcp_assigner; // Assigned us to do checking. 2081 struct rcu_torture_reader_check *rtrcp_chked; // Reader being checked. 2082 struct rcu_torture_reader_check *rtrcp_chker; // Reader doing checking when not me. 2083 2084 if (myid < 0) 2085 return; // Don't try this from timer handlers. 2086 2087 // Increment my counter. 2088 rtrcp = &rcu_torture_reader_mbchk[myid]; 2089 WRITE_ONCE(rtrcp->rtc_myloops, rtrcp->rtc_myloops + 1); 2090 2091 // Attempt to assign someone else some checking work. 2092 rdrchked = torture_random(trsp) % nrealreaders; 2093 rtrcp_chked = &rcu_torture_reader_mbchk[rdrchked]; 2094 rdrchker = torture_random(trsp) % nrealreaders; 2095 rtrcp_chker = &rcu_torture_reader_mbchk[rdrchker]; 2096 if (rdrchked != myid && rdrchked != rdrchker && noc >= rdrchked && noc >= rdrchker && 2097 smp_load_acquire(&rtrcp->rtc_chkrdr) < 0 && // Pairs with smp_store_release below. 2098 !READ_ONCE(rtp->rtort_chkp) && 2099 !smp_load_acquire(&rtrcp_chker->rtc_assigner)) { // Pairs with smp_store_release below. 2100 rtrcp->rtc_chkloops = READ_ONCE(rtrcp_chked->rtc_myloops); 2101 WARN_ON_ONCE(rtrcp->rtc_chkrdr >= 0); 2102 rtrcp->rtc_chkrdr = rdrchked; 2103 WARN_ON_ONCE(rtrcp->rtc_ready); // This gets set after the grace period ends. 2104 if (cmpxchg_relaxed(&rtrcp_chker->rtc_assigner, NULL, rtrcp) || 2105 cmpxchg_relaxed(&rtp->rtort_chkp, NULL, rtrcp)) 2106 (void)cmpxchg_relaxed(&rtrcp_chker->rtc_assigner, rtrcp, NULL); // Back out. 2107 } 2108 2109 // If assigned some completed work, do it! 2110 rtrcp_assigner = READ_ONCE(rtrcp->rtc_assigner); 2111 if (!rtrcp_assigner || !smp_load_acquire(&rtrcp_assigner->rtc_ready)) 2112 return; // No work or work not yet ready. 2113 rdrchked = rtrcp_assigner->rtc_chkrdr; 2114 if (WARN_ON_ONCE(rdrchked < 0)) 2115 return; 2116 rtrcp_chked = &rcu_torture_reader_mbchk[rdrchked]; 2117 loops = READ_ONCE(rtrcp_chked->rtc_myloops); 2118 atomic_inc(&n_rcu_torture_mbchk_tries); 2119 if (ULONG_CMP_LT(loops, rtrcp_assigner->rtc_chkloops)) 2120 atomic_inc(&n_rcu_torture_mbchk_fail); 2121 rtrcp_assigner->rtc_chkloops = loops + ULONG_MAX / 2; 2122 rtrcp_assigner->rtc_ready = 0; 2123 smp_store_release(&rtrcp->rtc_assigner, NULL); // Someone else can assign us work. 2124 smp_store_release(&rtrcp_assigner->rtc_chkrdr, -1); // Assigner can again assign. 2125 } 2126 2127 // Verify the specified RCUTORTURE_RDR* state. 2128 #define ROEC_ARGS "%s %s: Current %#x To add %#x To remove %#x preempt_count() %#x\n", __func__, s, curstate, new, old, preempt_count() 2129 static void rcutorture_one_extend_check(char *s, int curstate, int new, int old) 2130 { 2131 int mask; 2132 2133 if (!IS_ENABLED(CONFIG_RCU_TORTURE_TEST_CHK_RDR_STATE) || in_nmi()) 2134 return; 2135 2136 WARN_ONCE(!(curstate & RCUTORTURE_RDR_IRQ) && irqs_disabled() && !in_hardirq(), ROEC_ARGS); 2137 WARN_ONCE((curstate & RCUTORTURE_RDR_IRQ) && !irqs_disabled(), ROEC_ARGS); 2138 2139 // If CONFIG_PREEMPT_COUNT=n, further checks are unreliable. 2140 if (!IS_ENABLED(CONFIG_PREEMPT_COUNT)) 2141 return; 2142 2143 WARN_ONCE((curstate & (RCUTORTURE_RDR_BH | RCUTORTURE_RDR_RBH)) && 2144 !softirq_count(), ROEC_ARGS); 2145 WARN_ONCE((curstate & (RCUTORTURE_RDR_PREEMPT | RCUTORTURE_RDR_SCHED)) && 2146 !(preempt_count() & PREEMPT_MASK), ROEC_ARGS); 2147 WARN_ONCE(cur_ops->readlock_nesting && 2148 (curstate & (RCUTORTURE_RDR_RCU_1 | RCUTORTURE_RDR_RCU_2)) && 2149 cur_ops->readlock_nesting() == 0, ROEC_ARGS); 2150 2151 // Interrupt handlers have all sorts of stuff disabled, so ignore 2152 // unintended disabling. 2153 if (in_serving_softirq() || in_hardirq()) 2154 return; 2155 2156 WARN_ONCE(cur_ops->extendables && 2157 !(curstate & (RCUTORTURE_RDR_BH | RCUTORTURE_RDR_RBH)) && 2158 softirq_count(), ROEC_ARGS); 2159 2160 /* 2161 * non-preemptible RCU in a preemptible kernel uses preempt_disable() 2162 * as rcu_read_lock(). 2163 */ 2164 mask = RCUTORTURE_RDR_PREEMPT | RCUTORTURE_RDR_SCHED; 2165 if (!IS_ENABLED(CONFIG_PREEMPT_RCU)) 2166 mask |= RCUTORTURE_RDR_RCU_1 | RCUTORTURE_RDR_RCU_2; 2167 2168 WARN_ONCE(cur_ops->extendables && !(curstate & mask) && 2169 (preempt_count() & PREEMPT_MASK), ROEC_ARGS); 2170 2171 /* 2172 * non-preemptible RCU in a preemptible kernel uses "preempt_count() & 2173 * PREEMPT_MASK" as ->readlock_nesting(). 2174 */ 2175 mask = RCUTORTURE_RDR_RCU_1 | RCUTORTURE_RDR_RCU_2; 2176 if (!IS_ENABLED(CONFIG_PREEMPT_RCU)) 2177 mask |= RCUTORTURE_RDR_PREEMPT | RCUTORTURE_RDR_SCHED; 2178 2179 if (IS_ENABLED(CONFIG_PREEMPT_RT) && softirq_count()) 2180 mask |= RCUTORTURE_RDR_BH | RCUTORTURE_RDR_RBH; 2181 2182 WARN_ONCE(cur_ops->readlock_nesting && !(curstate & mask) && 2183 cur_ops->readlock_nesting() > 0, ROEC_ARGS); 2184 } 2185 2186 /* 2187 * Do one extension of an RCU read-side critical section using the 2188 * current reader state in readstate (set to zero for initial entry 2189 * to extended critical section), set the new state as specified by 2190 * newstate (set to zero for final exit from extended critical section), 2191 * and random-number-generator state in trsp. If this is neither the 2192 * beginning or end of the critical section and if there was actually a 2193 * change, do a ->read_delay(). 2194 */ 2195 static void rcutorture_one_extend(int *readstate, int newstate, struct torture_random_state *trsp, 2196 struct rt_read_seg *rtrsp) 2197 { 2198 bool first; 2199 unsigned long flags; 2200 int idxnew1 = -1; 2201 int idxnew2 = -1; 2202 int idxold1 = *readstate; 2203 int idxold2 = idxold1; 2204 int statesnew = ~*readstate & newstate; 2205 int statesold = *readstate & ~newstate; 2206 2207 first = idxold1 == 0; 2208 WARN_ON_ONCE(idxold2 < 0); 2209 WARN_ON_ONCE(idxold2 & ~(RCUTORTURE_RDR_ALLBITS | RCUTORTURE_RDR_UPDOWN)); 2210 rcutorture_one_extend_check("before change", idxold1, statesnew, statesold); 2211 rtrsp->rt_readstate = newstate; 2212 2213 /* First, put new protection in place to avoid critical-section gap. */ 2214 if (statesnew & RCUTORTURE_RDR_BH) 2215 local_bh_disable(); 2216 if (statesnew & RCUTORTURE_RDR_RBH) 2217 rcu_read_lock_bh(); 2218 if (statesnew & RCUTORTURE_RDR_IRQ) 2219 local_irq_disable(); 2220 if (statesnew & RCUTORTURE_RDR_PREEMPT) 2221 preempt_disable(); 2222 if (statesnew & RCUTORTURE_RDR_SCHED) 2223 rcu_read_lock_sched(); 2224 if (statesnew & RCUTORTURE_RDR_RCU_1) 2225 idxnew1 = (cur_ops->readlock() << RCUTORTURE_RDR_SHIFT_1) & RCUTORTURE_RDR_MASK_1; 2226 if (statesnew & RCUTORTURE_RDR_RCU_2) 2227 idxnew2 = (cur_ops->readlock() << RCUTORTURE_RDR_SHIFT_2) & RCUTORTURE_RDR_MASK_2; 2228 2229 // Complain unless both the old and the new protection is in place. 2230 rcutorture_one_extend_check("during change", idxold1 | statesnew, statesnew, statesold); 2231 2232 // Sample CPU under both sets of protections to reduce confusion. 2233 if (IS_ENABLED(CONFIG_RCU_TORTURE_TEST_LOG_CPU)) { 2234 int cpu = raw_smp_processor_id(); 2235 rtrsp->rt_cpu = cpu; 2236 if (!first) { 2237 rtrsp[-1].rt_end_cpu = cpu; 2238 if (cur_ops->reader_blocked) 2239 rtrsp[-1].rt_preempted = cur_ops->reader_blocked(); 2240 } 2241 } 2242 // Sample grace-period sequence number, as good a place as any. 2243 if (IS_ENABLED(CONFIG_RCU_TORTURE_TEST_LOG_GP) && cur_ops->gather_gp_seqs) { 2244 rtrsp->rt_gp_seq = cur_ops->gather_gp_seqs(); 2245 rtrsp->rt_ts = ktime_get_mono_fast_ns(); 2246 if (!first) 2247 rtrsp[-1].rt_gp_seq_end = rtrsp->rt_gp_seq; 2248 } 2249 2250 /* 2251 * Next, remove old protection, in decreasing order of strength 2252 * to avoid unlock paths that aren't safe in the stronger 2253 * context. Namely: BH can not be enabled with disabled interrupts. 2254 * Additionally PREEMPT_RT requires that BH is enabled in preemptible 2255 * context. 2256 */ 2257 if (statesold & RCUTORTURE_RDR_IRQ) 2258 local_irq_enable(); 2259 if (statesold & RCUTORTURE_RDR_PREEMPT) 2260 preempt_enable(); 2261 if (statesold & RCUTORTURE_RDR_SCHED) 2262 rcu_read_unlock_sched(); 2263 if (statesold & RCUTORTURE_RDR_BH) 2264 local_bh_enable(); 2265 if (statesold & RCUTORTURE_RDR_RBH) 2266 rcu_read_unlock_bh(); 2267 if (statesold & RCUTORTURE_RDR_RCU_2) { 2268 cur_ops->readunlock((idxold2 & RCUTORTURE_RDR_MASK_2) >> RCUTORTURE_RDR_SHIFT_2); 2269 WARN_ON_ONCE(idxnew2 != -1); 2270 idxold2 = 0; 2271 } 2272 if (statesold & RCUTORTURE_RDR_RCU_1) { 2273 bool lockit; 2274 2275 lockit = !cur_ops->no_pi_lock && !statesnew && !(torture_random(trsp) & 0xffff); 2276 if (lockit) 2277 raw_spin_lock_irqsave(¤t->pi_lock, flags); 2278 cur_ops->readunlock((idxold1 & RCUTORTURE_RDR_MASK_1) >> RCUTORTURE_RDR_SHIFT_1); 2279 WARN_ON_ONCE(idxnew1 != -1); 2280 idxold1 = 0; 2281 if (lockit) 2282 raw_spin_unlock_irqrestore(¤t->pi_lock, flags); 2283 } 2284 if (statesold & RCUTORTURE_RDR_UPDOWN) { 2285 cur_ops->up_read((idxold1 & RCUTORTURE_RDR_MASK_1) >> RCUTORTURE_RDR_SHIFT_1); 2286 WARN_ON_ONCE(idxnew1 != -1); 2287 idxold1 = 0; 2288 } 2289 2290 /* Delay if neither beginning nor end and there was a change. */ 2291 if ((statesnew || statesold) && *readstate && newstate) 2292 cur_ops->read_delay(trsp, rtrsp); 2293 2294 /* Update the reader state. */ 2295 if (idxnew1 == -1) 2296 idxnew1 = idxold1 & RCUTORTURE_RDR_MASK_1; 2297 WARN_ON_ONCE(idxnew1 < 0); 2298 if (idxnew2 == -1) 2299 idxnew2 = idxold2 & RCUTORTURE_RDR_MASK_2; 2300 WARN_ON_ONCE(idxnew2 < 0); 2301 *readstate = idxnew1 | idxnew2 | newstate; 2302 WARN_ON_ONCE(*readstate < 0); 2303 if (WARN_ON_ONCE(*readstate & ~RCUTORTURE_RDR_ALLBITS)) 2304 pr_info("Unexpected readstate value of %#x\n", *readstate); 2305 rcutorture_one_extend_check("after change", *readstate, statesnew, statesold); 2306 } 2307 2308 /* Return the biggest extendables mask given current RCU and boot parameters. */ 2309 static int rcutorture_extend_mask_max(void) 2310 { 2311 int mask; 2312 2313 WARN_ON_ONCE(extendables & ~RCUTORTURE_MAX_EXTEND); 2314 mask = extendables & RCUTORTURE_MAX_EXTEND & cur_ops->extendables; 2315 mask = mask | RCUTORTURE_RDR_RCU_1 | RCUTORTURE_RDR_RCU_2; 2316 return mask; 2317 } 2318 2319 /* Return a random protection state mask, but with at least one bit set. */ 2320 static int 2321 rcutorture_extend_mask(int oldmask, struct torture_random_state *trsp) 2322 { 2323 int mask = rcutorture_extend_mask_max(); 2324 unsigned long randmask1 = torture_random(trsp); 2325 unsigned long randmask2 = randmask1 >> 3; 2326 unsigned long preempts = RCUTORTURE_RDR_PREEMPT | RCUTORTURE_RDR_SCHED; 2327 unsigned long preempts_irq = preempts | RCUTORTURE_RDR_IRQ; 2328 unsigned long bhs = RCUTORTURE_RDR_BH | RCUTORTURE_RDR_RBH; 2329 2330 WARN_ON_ONCE(mask >> RCUTORTURE_RDR_SHIFT_1); // Can't have reader idx bits. 2331 /* Mostly only one bit (need preemption!), sometimes lots of bits. */ 2332 if (!(randmask1 & 0x7)) 2333 mask = mask & randmask2; 2334 else 2335 mask = mask & (1 << (randmask2 % RCUTORTURE_RDR_NBITS)); 2336 2337 // Can't have nested RCU reader without outer RCU reader. 2338 if (!(mask & RCUTORTURE_RDR_RCU_1) && (mask & RCUTORTURE_RDR_RCU_2)) { 2339 if (oldmask & RCUTORTURE_RDR_RCU_1) 2340 mask &= ~RCUTORTURE_RDR_RCU_2; 2341 else 2342 mask |= RCUTORTURE_RDR_RCU_1; 2343 } 2344 2345 /* 2346 * Can't enable bh w/irq disabled. 2347 */ 2348 if (mask & RCUTORTURE_RDR_IRQ) 2349 mask |= oldmask & bhs; 2350 2351 /* 2352 * Ideally these sequences would be detected in debug builds 2353 * (regardless of RT), but until then don't stop testing 2354 * them on non-RT. 2355 */ 2356 if (IS_ENABLED(CONFIG_PREEMPT_RT)) { 2357 /* Can't modify BH in atomic context */ 2358 if (oldmask & preempts_irq) 2359 mask &= ~bhs; 2360 if ((oldmask | mask) & preempts_irq) 2361 mask |= oldmask & bhs; 2362 } 2363 2364 return mask ?: RCUTORTURE_RDR_RCU_1; 2365 } 2366 2367 /* 2368 * Do a randomly selected number of extensions of an existing RCU read-side 2369 * critical section. 2370 */ 2371 static struct rt_read_seg * 2372 rcutorture_loop_extend(int *readstate, struct torture_random_state *trsp, struct rt_read_seg *rtrsp) 2373 { 2374 int i; 2375 int j; 2376 int mask = rcutorture_extend_mask_max(); 2377 2378 WARN_ON_ONCE(!*readstate); /* -Existing- RCU read-side critsect! */ 2379 if (!((mask - 1) & mask)) 2380 return rtrsp; /* Current RCU reader not extendable. */ 2381 /* Bias towards larger numbers of loops. */ 2382 i = torture_random(trsp); 2383 i = ((i | (i >> 3)) & RCUTORTURE_RDR_MAX_LOOPS) + 1; 2384 for (j = 0; j < i; j++) { 2385 mask = rcutorture_extend_mask(*readstate, trsp); 2386 WARN_ON_ONCE(mask & RCUTORTURE_RDR_UPDOWN); 2387 rcutorture_one_extend(readstate, mask, trsp, &rtrsp[j]); 2388 } 2389 return &rtrsp[j]; 2390 } 2391 2392 struct rcu_torture_one_read_state { 2393 bool checkpolling; 2394 unsigned long cookie; 2395 struct rcu_gp_oldstate cookie_full; 2396 unsigned long started; 2397 struct rcu_torture *p; 2398 int readstate; 2399 struct rt_read_seg rtseg[RCUTORTURE_RDR_MAX_SEGS]; 2400 struct rt_read_seg *rtrsp; 2401 unsigned long long ts; 2402 }; 2403 2404 static void init_rcu_torture_one_read_state(struct rcu_torture_one_read_state *rtorsp, 2405 struct torture_random_state *trsp) 2406 { 2407 memset(rtorsp, 0, sizeof(*rtorsp)); 2408 rtorsp->checkpolling = !(torture_random(trsp) & 0xfff); 2409 rtorsp->rtrsp = &rtorsp->rtseg[0]; 2410 } 2411 2412 /* 2413 * Set up the first segment of a series of overlapping read-side 2414 * critical sections. The caller must have actually initiated the 2415 * outermost read-side critical section. 2416 */ 2417 static bool rcu_torture_one_read_start(struct rcu_torture_one_read_state *rtorsp, 2418 struct torture_random_state *trsp, long myid) 2419 { 2420 if (rtorsp->checkpolling) { 2421 if (cur_ops->get_gp_state && cur_ops->poll_gp_state) 2422 rtorsp->cookie = cur_ops->get_gp_state(); 2423 if (cur_ops->get_gp_state_full && cur_ops->poll_gp_state_full) 2424 cur_ops->get_gp_state_full(&rtorsp->cookie_full); 2425 } 2426 rtorsp->started = cur_ops->get_gp_seq(); 2427 rtorsp->ts = rcu_trace_clock_local(); 2428 rtorsp->p = rcu_dereference_check(rcu_torture_current, 2429 !cur_ops->readlock_held || cur_ops->readlock_held() || 2430 (rtorsp->readstate & RCUTORTURE_RDR_UPDOWN)); 2431 if (rtorsp->p == NULL) { 2432 /* Wait for rcu_torture_writer to get underway */ 2433 rcutorture_one_extend(&rtorsp->readstate, 0, trsp, rtorsp->rtrsp); 2434 return false; 2435 } 2436 if (rtorsp->p->rtort_mbtest == 0) 2437 atomic_inc(&n_rcu_torture_mberror); 2438 rcu_torture_reader_do_mbchk(myid, rtorsp->p, trsp); 2439 return true; 2440 } 2441 2442 /* 2443 * Complete the last segment of a series of overlapping read-side 2444 * critical sections and check for errors. 2445 */ 2446 static void rcu_torture_one_read_end(struct rcu_torture_one_read_state *rtorsp, 2447 struct torture_random_state *trsp) 2448 { 2449 int i; 2450 unsigned long completed; 2451 int pipe_count; 2452 bool preempted = false; 2453 struct rt_read_seg *rtrsp1; 2454 2455 preempt_disable(); 2456 pipe_count = READ_ONCE(rtorsp->p->rtort_pipe_count); 2457 if (pipe_count > RCU_TORTURE_PIPE_LEN) { 2458 // Should not happen in a correct RCU implementation, 2459 // happens quite often for torture_type=busted. 2460 pipe_count = RCU_TORTURE_PIPE_LEN; 2461 } 2462 completed = cur_ops->get_gp_seq(); 2463 if (pipe_count > 1) { 2464 do_trace_rcu_torture_read(cur_ops->name, &rtorsp->p->rtort_rcu, 2465 rtorsp->ts, rtorsp->started, completed); 2466 rcu_ftrace_dump(DUMP_ALL); 2467 } 2468 __this_cpu_inc(rcu_torture_count[pipe_count]); 2469 completed = rcutorture_seq_diff(completed, rtorsp->started); 2470 if (completed > RCU_TORTURE_PIPE_LEN) { 2471 /* Should not happen, but... */ 2472 completed = RCU_TORTURE_PIPE_LEN; 2473 } 2474 __this_cpu_inc(rcu_torture_batch[completed]); 2475 preempt_enable(); 2476 if (rtorsp->checkpolling) { 2477 if (cur_ops->get_gp_state && cur_ops->poll_gp_state) 2478 WARN_ONCE(cur_ops->poll_gp_state(rtorsp->cookie), 2479 "%s: Cookie check 2 failed %s(%d) %lu->%lu\n", 2480 __func__, 2481 rcu_torture_writer_state_getname(), 2482 rcu_torture_writer_state, 2483 rtorsp->cookie, cur_ops->get_gp_state()); 2484 if (cur_ops->get_gp_state_full && cur_ops->poll_gp_state_full) 2485 WARN_ONCE(cur_ops->poll_gp_state_full(&rtorsp->cookie_full), 2486 "%s: Cookie check 6 failed %s(%d) online %*pbl\n", 2487 __func__, 2488 rcu_torture_writer_state_getname(), 2489 rcu_torture_writer_state, 2490 cpumask_pr_args(cpu_online_mask)); 2491 } 2492 if (cur_ops->reader_blocked) 2493 preempted = cur_ops->reader_blocked(); 2494 rcutorture_one_extend(&rtorsp->readstate, 0, trsp, rtorsp->rtrsp); 2495 WARN_ON_ONCE(rtorsp->readstate); 2496 // This next splat is expected behavior if leakpointer, especially 2497 // for CONFIG_RCU_STRICT_GRACE_PERIOD=y kernels. 2498 WARN_ON_ONCE(leakpointer && READ_ONCE(rtorsp->p->rtort_pipe_count) > 1); 2499 2500 /* If error or close call, record the sequence of reader protections. */ 2501 if ((pipe_count > 1 || completed > 1) && !xchg(&err_segs_recorded, 1)) { 2502 i = 0; 2503 for (rtrsp1 = &rtorsp->rtseg[0]; rtrsp1 < rtorsp->rtrsp; rtrsp1++) 2504 err_segs[i++] = *rtrsp1; 2505 rt_read_nsegs = i; 2506 rt_read_preempted = preempted; 2507 } 2508 } 2509 2510 /* 2511 * Do one read-side critical section, returning false if there was 2512 * no data to read. Can be invoked both from process context and 2513 * from a timer handler. 2514 */ 2515 static bool rcu_torture_one_read(struct torture_random_state *trsp, long myid) 2516 { 2517 int newstate; 2518 struct rcu_torture_one_read_state rtors; 2519 2520 WARN_ON_ONCE(!rcu_is_watching()); 2521 init_rcu_torture_one_read_state(&rtors, trsp); 2522 newstate = rcutorture_extend_mask(rtors.readstate, trsp); 2523 WARN_ON_ONCE(newstate & RCUTORTURE_RDR_UPDOWN); 2524 rcutorture_one_extend(&rtors.readstate, newstate, trsp, rtors.rtrsp++); 2525 if (!rcu_torture_one_read_start(&rtors, trsp, myid)) 2526 return false; 2527 rtors.rtrsp = rcutorture_loop_extend(&rtors.readstate, trsp, rtors.rtrsp); 2528 rcu_torture_one_read_end(&rtors, trsp); 2529 return true; 2530 } 2531 2532 static DEFINE_TORTURE_RANDOM_PERCPU(rcu_torture_timer_rand); 2533 2534 /* 2535 * RCU torture reader from timer handler. Dereferences rcu_torture_current, 2536 * incrementing the corresponding element of the pipeline array. The 2537 * counter in the element should never be greater than 1, otherwise, the 2538 * RCU implementation is broken. 2539 */ 2540 static void rcu_torture_timer(struct timer_list *unused) 2541 { 2542 WARN_ON_ONCE(!in_serving_softirq()); 2543 WARN_ON_ONCE(in_hardirq()); 2544 WARN_ON_ONCE(in_nmi()); 2545 atomic_long_inc(&n_rcu_torture_timers); 2546 (void)rcu_torture_one_read(this_cpu_ptr(&rcu_torture_timer_rand), -1); 2547 2548 /* Test call_rcu() invocation from interrupt handler. */ 2549 if (cur_ops->call) { 2550 struct rcu_head *rhp = kmalloc_obj(*rhp, GFP_NOWAIT); 2551 2552 if (rhp) 2553 cur_ops->call(rhp, rcu_torture_timer_cb); 2554 } 2555 } 2556 2557 /* 2558 * RCU torture reader kthread. Repeatedly dereferences rcu_torture_current, 2559 * incrementing the corresponding element of the pipeline array. The 2560 * counter in the element should never be greater than 1, otherwise, the 2561 * RCU implementation is broken. 2562 */ 2563 static int 2564 rcu_torture_reader(void *arg) 2565 { 2566 unsigned long lastsleep = jiffies; 2567 long myid = (long)arg; 2568 int mynumonline = myid; 2569 DEFINE_TORTURE_RANDOM(rand); 2570 struct timer_list t; 2571 2572 VERBOSE_TOROUT_STRING("rcu_torture_reader task started"); 2573 set_user_nice(current, MAX_NICE); 2574 if (irqreader && cur_ops->irq_capable) 2575 timer_setup_on_stack(&t, rcu_torture_timer, 0); 2576 tick_dep_set_task(current, TICK_DEP_BIT_RCU); // CPU bound, so need tick. 2577 do { 2578 if (irqreader && cur_ops->irq_capable) { 2579 if (!timer_pending(&t)) 2580 mod_timer(&t, jiffies + 1); 2581 } 2582 if (!rcu_torture_one_read(&rand, myid) && !torture_must_stop()) 2583 schedule_timeout_interruptible(HZ); 2584 if (time_after(jiffies, lastsleep) && !torture_must_stop()) { 2585 torture_hrtimeout_us(500, 1000, &rand); 2586 lastsleep = jiffies + 10; 2587 } 2588 while (!torture_must_stop() && 2589 (torture_num_online_cpus() < mynumonline || !rcu_inkernel_boot_has_ended())) 2590 schedule_timeout_interruptible(HZ / 5); 2591 stutter_wait("rcu_torture_reader"); 2592 } while (!torture_must_stop()); 2593 if (irqreader && cur_ops->irq_capable) { 2594 timer_delete_sync(&t); 2595 timer_destroy_on_stack(&t); 2596 } 2597 tick_dep_clear_task(current, TICK_DEP_BIT_RCU); 2598 torture_kthread_stopping("rcu_torture_reader"); 2599 return 0; 2600 } 2601 2602 struct rcu_torture_one_read_state_updown { 2603 struct hrtimer rtorsu_hrt; 2604 bool rtorsu_inuse; 2605 ktime_t rtorsu_kt; 2606 int rtorsu_cpu; 2607 unsigned long rtorsu_j; 2608 unsigned long rtorsu_ndowns; 2609 unsigned long rtorsu_nups; 2610 unsigned long rtorsu_nmigrates; 2611 struct torture_random_state rtorsu_trs; 2612 struct rcu_torture_one_read_state rtorsu_rtors; 2613 }; 2614 2615 static struct rcu_torture_one_read_state_updown *updownreaders; 2616 static DEFINE_TORTURE_RANDOM(rcu_torture_updown_rand); 2617 static int rcu_torture_updown(void *arg); 2618 2619 static enum hrtimer_restart rcu_torture_updown_hrt(struct hrtimer *hrtp) 2620 { 2621 int cpu = raw_smp_processor_id(); 2622 struct rcu_torture_one_read_state_updown *rtorsup; 2623 2624 rtorsup = container_of(hrtp, struct rcu_torture_one_read_state_updown, rtorsu_hrt); 2625 rcu_torture_one_read_end(&rtorsup->rtorsu_rtors, &rtorsup->rtorsu_trs); 2626 WARN_ONCE(rtorsup->rtorsu_nups >= rtorsup->rtorsu_ndowns, "%s: Up without matching down #%zu.\n", __func__, rtorsup - updownreaders); 2627 WRITE_ONCE(rtorsup->rtorsu_nups, rtorsup->rtorsu_nups + 1); 2628 WRITE_ONCE(rtorsup->rtorsu_nmigrates, 2629 rtorsup->rtorsu_nmigrates + (cpu != rtorsup->rtorsu_cpu)); 2630 smp_store_release(&rtorsup->rtorsu_inuse, false); 2631 return HRTIMER_NORESTART; 2632 } 2633 2634 static int rcu_torture_updown_init(void) 2635 { 2636 int i; 2637 struct torture_random_state *rand = &rcu_torture_updown_rand; 2638 int ret; 2639 2640 if (n_up_down < 0) 2641 return 0; 2642 if (!srcu_torture_have_up_down()) { 2643 VERBOSE_TOROUT_STRING("rcu_torture_updown_init: Disabling up/down reader tests due to lack of primitives"); 2644 return 0; 2645 } 2646 updownreaders = kzalloc_objs(*updownreaders, n_up_down); 2647 if (!updownreaders) { 2648 VERBOSE_TOROUT_STRING("rcu_torture_updown_init: Out of memory, disabling up/down reader tests"); 2649 return -ENOMEM; 2650 } 2651 for (i = 0; i < n_up_down; i++) { 2652 init_rcu_torture_one_read_state(&updownreaders[i].rtorsu_rtors, rand); 2653 hrtimer_setup(&updownreaders[i].rtorsu_hrt, rcu_torture_updown_hrt, CLOCK_MONOTONIC, 2654 HRTIMER_MODE_REL | HRTIMER_MODE_HARD); 2655 torture_random_init(&updownreaders[i].rtorsu_trs); 2656 init_rcu_torture_one_read_state(&updownreaders[i].rtorsu_rtors, 2657 &updownreaders[i].rtorsu_trs); 2658 } 2659 ret = torture_create_kthread(rcu_torture_updown, rand, updown_task); 2660 if (ret) { 2661 kfree(updownreaders); 2662 updownreaders = NULL; 2663 } 2664 return ret; 2665 } 2666 2667 static void rcu_torture_updown_cleanup(void) 2668 { 2669 struct rcu_torture_one_read_state_updown *rtorsup; 2670 2671 for (rtorsup = updownreaders; rtorsup < &updownreaders[n_up_down]; rtorsup++) { 2672 if (!smp_load_acquire(&rtorsup->rtorsu_inuse)) 2673 continue; 2674 if (hrtimer_cancel(&rtorsup->rtorsu_hrt) || WARN_ON_ONCE(rtorsup->rtorsu_inuse)) { 2675 rcu_torture_one_read_end(&rtorsup->rtorsu_rtors, &rtorsup->rtorsu_trs); 2676 WARN_ONCE(rtorsup->rtorsu_nups >= rtorsup->rtorsu_ndowns, "%s: Up without matching down #%zu.\n", __func__, rtorsup - updownreaders); 2677 WRITE_ONCE(rtorsup->rtorsu_nups, rtorsup->rtorsu_nups + 1); 2678 smp_store_release(&rtorsup->rtorsu_inuse, false); 2679 } 2680 2681 } 2682 kfree(updownreaders); 2683 updownreaders = NULL; 2684 } 2685 2686 // Do one reader for rcu_torture_updown(). 2687 static void rcu_torture_updown_one(struct rcu_torture_one_read_state_updown *rtorsup) 2688 { 2689 int idx; 2690 int rawidx; 2691 ktime_t t; 2692 2693 init_rcu_torture_one_read_state(&rtorsup->rtorsu_rtors, &rtorsup->rtorsu_trs); 2694 rawidx = cur_ops->down_read(); 2695 WRITE_ONCE(rtorsup->rtorsu_ndowns, rtorsup->rtorsu_ndowns + 1); 2696 idx = (rawidx << RCUTORTURE_RDR_SHIFT_1) & RCUTORTURE_RDR_MASK_1; 2697 rtorsup->rtorsu_rtors.readstate = idx | RCUTORTURE_RDR_UPDOWN; 2698 rtorsup->rtorsu_rtors.rtrsp++; 2699 rtorsup->rtorsu_cpu = raw_smp_processor_id(); 2700 if (!rcu_torture_one_read_start(&rtorsup->rtorsu_rtors, &rtorsup->rtorsu_trs, -1)) { 2701 WARN_ONCE(rtorsup->rtorsu_nups >= rtorsup->rtorsu_ndowns, "%s: Up without matching down #%zu.\n", __func__, rtorsup - updownreaders); 2702 WRITE_ONCE(rtorsup->rtorsu_nups, rtorsup->rtorsu_nups + 1); 2703 schedule_timeout_idle(HZ); 2704 return; 2705 } 2706 smp_store_release(&rtorsup->rtorsu_inuse, true); 2707 t = torture_random(&rtorsup->rtorsu_trs) & 0xfffff; // One per million. 2708 if (t < 10 * 1000) 2709 t = 200 * 1000 * 1000; 2710 hrtimer_start(&rtorsup->rtorsu_hrt, t, HRTIMER_MODE_REL | HRTIMER_MODE_HARD); 2711 smp_mb(); // Sample jiffies after posting hrtimer. 2712 rtorsup->rtorsu_j = jiffies; // Not used by hrtimer handler. 2713 rtorsup->rtorsu_kt = t; 2714 } 2715 2716 /* 2717 * RCU torture up/down reader kthread, starting RCU readers in kthread 2718 * context and ending them in hrtimer handlers. Otherwise similar to 2719 * rcu_torture_reader(). 2720 */ 2721 static int 2722 rcu_torture_updown(void *arg) 2723 { 2724 unsigned long j; 2725 struct rcu_torture_one_read_state_updown *rtorsup; 2726 2727 VERBOSE_TOROUT_STRING("rcu_torture_updown task started"); 2728 do { 2729 for (rtorsup = updownreaders; rtorsup < &updownreaders[n_up_down]; rtorsup++) { 2730 if (torture_must_stop()) 2731 break; 2732 j = smp_load_acquire(&jiffies); // Time before ->rtorsu_inuse. 2733 if (smp_load_acquire(&rtorsup->rtorsu_inuse)) { 2734 WARN_ONCE(time_after(j, rtorsup->rtorsu_j + 1 + HZ * 10), 2735 "hrtimer queued at jiffies %lu for %lld ns took %lu jiffies\n", rtorsup->rtorsu_j, rtorsup->rtorsu_kt, j - rtorsup->rtorsu_j); 2736 continue; 2737 } 2738 rcu_torture_updown_one(rtorsup); 2739 } 2740 torture_hrtimeout_ms(1, 1000, &rcu_torture_updown_rand); 2741 stutter_wait("rcu_torture_updown"); 2742 } while (!torture_must_stop()); 2743 rcu_torture_updown_cleanup(); 2744 torture_kthread_stopping("rcu_torture_updown"); 2745 return 0; 2746 } 2747 2748 /* 2749 * Randomly Toggle CPUs' callback-offload state. This uses hrtimers to 2750 * increase race probabilities and fuzzes the interval between toggling. 2751 */ 2752 static int rcu_nocb_toggle(void *arg) 2753 { 2754 int cpu; 2755 int maxcpu = -1; 2756 int oldnice = task_nice(current); 2757 long r; 2758 DEFINE_TORTURE_RANDOM(rand); 2759 ktime_t toggle_delay; 2760 unsigned long toggle_fuzz; 2761 ktime_t toggle_interval = ms_to_ktime(nocbs_toggle); 2762 2763 VERBOSE_TOROUT_STRING("rcu_nocb_toggle task started"); 2764 while (!rcu_inkernel_boot_has_ended()) 2765 schedule_timeout_interruptible(HZ / 10); 2766 for_each_possible_cpu(cpu) 2767 maxcpu = cpu; 2768 WARN_ON(maxcpu < 0); 2769 if (toggle_interval > ULONG_MAX) 2770 toggle_fuzz = ULONG_MAX >> 3; 2771 else 2772 toggle_fuzz = toggle_interval >> 3; 2773 if (toggle_fuzz <= 0) 2774 toggle_fuzz = NSEC_PER_USEC; 2775 do { 2776 r = torture_random(&rand); 2777 cpu = (r >> 1) % (maxcpu + 1); 2778 if (r & 0x1) { 2779 rcu_nocb_cpu_offload(cpu); 2780 atomic_long_inc(&n_nocb_offload); 2781 } else { 2782 rcu_nocb_cpu_deoffload(cpu); 2783 atomic_long_inc(&n_nocb_deoffload); 2784 } 2785 toggle_delay = torture_random(&rand) % toggle_fuzz + toggle_interval; 2786 set_current_state(TASK_INTERRUPTIBLE); 2787 schedule_hrtimeout(&toggle_delay, HRTIMER_MODE_REL); 2788 if (stutter_wait("rcu_nocb_toggle")) 2789 sched_set_normal(current, oldnice); 2790 } while (!torture_must_stop()); 2791 torture_kthread_stopping("rcu_nocb_toggle"); 2792 return 0; 2793 } 2794 2795 /* 2796 * Print torture statistics. Caller must ensure that there is only 2797 * one call to this function at a given time!!! This is normally 2798 * accomplished by relying on the module system to only have one copy 2799 * of the module loaded, and then by giving the rcu_torture_stats 2800 * kthread full control (or the init/cleanup functions when rcu_torture_stats 2801 * thread is not running). 2802 */ 2803 static void 2804 rcu_torture_stats_print(void) 2805 { 2806 int cpu; 2807 int i; 2808 long pipesummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 }; 2809 long batchsummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 }; 2810 long n_gpwraps = 0; 2811 unsigned long ndowns = 0; 2812 unsigned long nunexpired = 0; 2813 unsigned long nmigrates = 0; 2814 unsigned long nups = 0; 2815 struct rcu_torture *rtcp; 2816 static unsigned long rtcv_snap = ULONG_MAX; 2817 static bool splatted; 2818 struct task_struct *wtp; 2819 2820 for_each_possible_cpu(cpu) { 2821 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) { 2822 pipesummary[i] += READ_ONCE(per_cpu(rcu_torture_count, cpu)[i]); 2823 batchsummary[i] += READ_ONCE(per_cpu(rcu_torture_batch, cpu)[i]); 2824 } 2825 if (cur_ops->get_gpwrap_count) 2826 n_gpwraps += cur_ops->get_gpwrap_count(cpu); 2827 } 2828 if (updownreaders) { 2829 for (i = 0; i < n_up_down; i++) { 2830 ndowns += READ_ONCE(updownreaders[i].rtorsu_ndowns); 2831 nups += READ_ONCE(updownreaders[i].rtorsu_nups); 2832 nunexpired += READ_ONCE(updownreaders[i].rtorsu_inuse); 2833 nmigrates += READ_ONCE(updownreaders[i].rtorsu_nmigrates); 2834 } 2835 } 2836 for (i = RCU_TORTURE_PIPE_LEN; i >= 0; i--) { 2837 if (pipesummary[i] != 0) 2838 break; 2839 } // The value of variable "i" is used later, so don't clobber it! 2840 2841 pr_alert("%s%s ", torture_type, TORTURE_FLAG); 2842 rtcp = rcu_access_pointer(rcu_torture_current); 2843 pr_cont("rtc: %p %s: %lu tfle: %d rta: %d rtaf: %d rtf: %d ", 2844 rtcp, 2845 rtcp && !rcu_stall_is_suppressed_at_boot() ? "ver" : "VER", 2846 rcu_torture_current_version, 2847 list_empty(&rcu_torture_freelist), 2848 atomic_read(&n_rcu_torture_alloc), 2849 atomic_read(&n_rcu_torture_alloc_fail), 2850 atomic_read(&n_rcu_torture_free)); 2851 pr_cont("rtmbe: %d rtmbkf: %d/%d rtbe: %ld rtbke: %ld ", 2852 atomic_read(&n_rcu_torture_mberror), 2853 atomic_read(&n_rcu_torture_mbchk_fail), atomic_read(&n_rcu_torture_mbchk_tries), 2854 n_rcu_torture_barrier_error, 2855 n_rcu_torture_boost_ktrerror); 2856 pr_cont("rtbf: %ld rtb: %ld nt: %ld ", 2857 n_rcu_torture_boost_failure, 2858 n_rcu_torture_boosts, 2859 atomic_long_read(&n_rcu_torture_timers)); 2860 if (updownreaders) 2861 pr_cont("ndowns: %lu nups: %lu nhrt: %lu nmigrates: %lu ", ndowns, nups, nunexpired, nmigrates); 2862 torture_onoff_stats(); 2863 pr_cont("barrier: %ld/%ld:%ld ", 2864 data_race(n_barrier_successes), 2865 data_race(n_barrier_attempts), 2866 data_race(n_rcu_torture_barrier_error)); 2867 pr_cont("read-exits: %ld ", data_race(n_read_exits)); // Statistic. 2868 pr_cont("nocb-toggles: %ld:%ld ", 2869 atomic_long_read(&n_nocb_offload), atomic_long_read(&n_nocb_deoffload)); 2870 pr_cont("gpwraps: %ld\n", n_gpwraps); 2871 2872 pr_alert("%s%s ", torture_type, TORTURE_FLAG); 2873 if (atomic_read(&n_rcu_torture_mberror) || 2874 atomic_read(&n_rcu_torture_mbchk_fail) || 2875 n_rcu_torture_barrier_error || n_rcu_torture_boost_ktrerror || 2876 n_rcu_torture_boost_failure || i > 1) { 2877 pr_cont("%s", "!!! "); 2878 atomic_inc(&n_rcu_torture_error); 2879 WARN_ON_ONCE(atomic_read(&n_rcu_torture_mberror)); 2880 WARN_ON_ONCE(atomic_read(&n_rcu_torture_mbchk_fail)); 2881 WARN_ON_ONCE(n_rcu_torture_barrier_error); // rcu_barrier() 2882 WARN_ON_ONCE(n_rcu_torture_boost_ktrerror); // no boost kthread 2883 WARN_ON_ONCE(n_rcu_torture_boost_failure); // boost failed (TIMER_SOFTIRQ RT prio?) 2884 WARN_ON_ONCE(i > 1); // Too-short grace period 2885 } 2886 pr_cont("Reader Pipe: "); 2887 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) 2888 pr_cont(" %ld", pipesummary[i]); 2889 pr_cont("\n"); 2890 2891 pr_alert("%s%s ", torture_type, TORTURE_FLAG); 2892 pr_cont("Reader Batch: "); 2893 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) 2894 pr_cont(" %ld", batchsummary[i]); 2895 pr_cont("\n"); 2896 2897 pr_alert("%s%s ", torture_type, TORTURE_FLAG); 2898 pr_cont("Free-Block Circulation: "); 2899 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) { 2900 pr_cont(" %d", atomic_read(&rcu_torture_wcount[i])); 2901 } 2902 pr_cont("\n"); 2903 2904 if (cur_ops->stats) 2905 cur_ops->stats(); 2906 if (rtcv_snap == rcu_torture_current_version && 2907 rcu_access_pointer(rcu_torture_current) && 2908 !rcu_stall_is_suppressed() && 2909 rcu_inkernel_boot_has_ended()) { 2910 int __maybe_unused flags = 0; 2911 unsigned long __maybe_unused gp_seq = 0; 2912 2913 if (cur_ops->get_gp_data) 2914 cur_ops->get_gp_data(&flags, &gp_seq); 2915 wtp = READ_ONCE(writer_task); 2916 pr_alert("??? Writer stall state %s(%d) g%lu f%#x ->state %#x cpu %d\n", 2917 rcu_torture_writer_state_getname(), 2918 rcu_torture_writer_state, gp_seq, flags, 2919 wtp == NULL ? ~0U : wtp->__state, 2920 wtp == NULL ? -1 : (int)task_cpu(wtp)); 2921 if (!splatted && wtp) { 2922 sched_show_task(wtp); 2923 splatted = true; 2924 } 2925 if (cur_ops->gp_kthread_dbg) 2926 cur_ops->gp_kthread_dbg(); 2927 rcu_ftrace_dump(DUMP_ALL); 2928 } 2929 rtcv_snap = rcu_torture_current_version; 2930 } 2931 2932 /* 2933 * Periodically prints torture statistics, if periodic statistics printing 2934 * was specified via the stat_interval module parameter. 2935 */ 2936 static int 2937 rcu_torture_stats(void *arg) 2938 { 2939 VERBOSE_TOROUT_STRING("rcu_torture_stats task started"); 2940 do { 2941 schedule_timeout_interruptible(stat_interval * HZ); 2942 rcu_torture_stats_print(); 2943 torture_shutdown_absorb("rcu_torture_stats"); 2944 } while (!torture_must_stop()); 2945 torture_kthread_stopping("rcu_torture_stats"); 2946 return 0; 2947 } 2948 2949 /* Test mem_dump_obj() and friends. */ 2950 static void rcu_torture_mem_dump_obj(void) 2951 { 2952 struct rcu_head *rhp; 2953 struct kmem_cache *kcp; 2954 static int z; 2955 2956 kcp = kmem_cache_create("rcuscale", 136, 8, SLAB_STORE_USER, NULL); 2957 if (WARN_ON_ONCE(!kcp)) 2958 return; 2959 rhp = kmem_cache_alloc(kcp, GFP_KERNEL); 2960 if (WARN_ON_ONCE(!rhp)) { 2961 kmem_cache_destroy(kcp); 2962 return; 2963 } 2964 pr_alert("mem_dump_obj() slab test: rcu_torture_stats = %px, &rhp = %px, rhp = %px, &z = %px\n", stats_task, &rhp, rhp, &z); 2965 pr_alert("mem_dump_obj(ZERO_SIZE_PTR):"); 2966 mem_dump_obj(ZERO_SIZE_PTR); 2967 pr_alert("mem_dump_obj(NULL):"); 2968 mem_dump_obj(NULL); 2969 pr_alert("mem_dump_obj(%px):", &rhp); 2970 mem_dump_obj(&rhp); 2971 pr_alert("mem_dump_obj(%px):", rhp); 2972 mem_dump_obj(rhp); 2973 pr_alert("mem_dump_obj(%px):", &rhp->func); 2974 mem_dump_obj(&rhp->func); 2975 pr_alert("mem_dump_obj(%px):", &z); 2976 mem_dump_obj(&z); 2977 kmem_cache_free(kcp, rhp); 2978 kmem_cache_destroy(kcp); 2979 rhp = kmalloc_obj(*rhp); 2980 if (WARN_ON_ONCE(!rhp)) 2981 return; 2982 pr_alert("mem_dump_obj() kmalloc test: rcu_torture_stats = %px, &rhp = %px, rhp = %px\n", stats_task, &rhp, rhp); 2983 pr_alert("mem_dump_obj(kmalloc %px):", rhp); 2984 mem_dump_obj(rhp); 2985 pr_alert("mem_dump_obj(kmalloc %px):", &rhp->func); 2986 mem_dump_obj(&rhp->func); 2987 kfree(rhp); 2988 rhp = vmalloc(4096); 2989 if (WARN_ON_ONCE(!rhp)) 2990 return; 2991 pr_alert("mem_dump_obj() vmalloc test: rcu_torture_stats = %px, &rhp = %px, rhp = %px\n", stats_task, &rhp, rhp); 2992 pr_alert("mem_dump_obj(vmalloc %px):", rhp); 2993 mem_dump_obj(rhp); 2994 pr_alert("mem_dump_obj(vmalloc %px):", &rhp->func); 2995 mem_dump_obj(&rhp->func); 2996 vfree(rhp); 2997 } 2998 2999 static void 3000 rcu_torture_print_module_parms(struct rcu_torture_ops *cur_ops, const char *tag) 3001 { 3002 pr_alert("%s" TORTURE_FLAG 3003 "--- %s: nreaders=%d nfakewriters=%d " 3004 "stat_interval=%d verbose=%d test_no_idle_hz=%d " 3005 "shuffle_interval=%d stutter=%d irqreader=%d " 3006 "fqs_duration=%d fqs_holdoff=%d fqs_stutter=%d " 3007 "test_boost=%d/%d test_boost_interval=%d " 3008 "test_boost_duration=%d test_boost_holdoff=%d shutdown_secs=%d " 3009 "stall_cpu=%d stall_cpu_holdoff=%d stall_cpu_irqsoff=%d " 3010 "stall_cpu_block=%d stall_cpu_repeat=%d " 3011 "n_barrier_cbs=%d " 3012 "onoff_interval=%d onoff_holdoff=%d " 3013 "read_exit_delay=%d read_exit_burst=%d " 3014 "reader_flavor=%x " 3015 "nocbs_nthreads=%d nocbs_toggle=%d " 3016 "test_nmis=%d " 3017 "preempt_duration=%d preempt_interval=%d n_up_down=%d\n", 3018 torture_type, tag, nrealreaders, nrealfakewriters, 3019 stat_interval, verbose, test_no_idle_hz, shuffle_interval, 3020 stutter, irqreader, fqs_duration, fqs_holdoff, fqs_stutter, 3021 test_boost, cur_ops->can_boost, 3022 test_boost_interval, test_boost_duration, test_boost_holdoff, shutdown_secs, 3023 stall_cpu, stall_cpu_holdoff, stall_cpu_irqsoff, 3024 stall_cpu_block, stall_cpu_repeat, 3025 n_barrier_cbs, 3026 onoff_interval, onoff_holdoff, 3027 read_exit_delay, read_exit_burst, 3028 reader_flavor, 3029 nocbs_nthreads, nocbs_toggle, 3030 test_nmis, 3031 preempt_duration, preempt_interval, n_up_down); 3032 } 3033 3034 static int rcutorture_booster_cleanup(unsigned int cpu) 3035 { 3036 struct task_struct *t; 3037 3038 if (boost_tasks[cpu] == NULL) 3039 return 0; 3040 mutex_lock(&boost_mutex); 3041 t = boost_tasks[cpu]; 3042 boost_tasks[cpu] = NULL; 3043 rcu_torture_enable_rt_throttle(); 3044 mutex_unlock(&boost_mutex); 3045 3046 /* This must be outside of the mutex, otherwise deadlock! */ 3047 torture_stop_kthread(rcu_torture_boost, t); 3048 return 0; 3049 } 3050 3051 static int rcutorture_booster_init(unsigned int cpu) 3052 { 3053 int retval; 3054 3055 if (boost_tasks[cpu] != NULL) 3056 return 0; /* Already created, nothing more to do. */ 3057 3058 // Testing RCU priority boosting requires rcutorture do 3059 // some serious abuse. Counter this by running ksoftirqd 3060 // at higher priority. 3061 if (IS_BUILTIN(CONFIG_RCU_TORTURE_TEST)) { 3062 struct sched_param sp; 3063 struct task_struct *t; 3064 3065 t = per_cpu(ksoftirqd, cpu); 3066 WARN_ON_ONCE(!t); 3067 sp.sched_priority = 2; 3068 sched_setscheduler_nocheck(t, SCHED_FIFO, &sp); 3069 #ifdef CONFIG_IRQ_FORCED_THREADING 3070 if (force_irqthreads()) { 3071 t = per_cpu(ktimerd, cpu); 3072 WARN_ON_ONCE(!t); 3073 sp.sched_priority = 2; 3074 sched_setscheduler_nocheck(t, SCHED_FIFO, &sp); 3075 } 3076 #endif 3077 } 3078 3079 /* Don't allow time recalculation while creating a new task. */ 3080 mutex_lock(&boost_mutex); 3081 rcu_torture_disable_rt_throttle(); 3082 VERBOSE_TOROUT_STRING("Creating rcu_torture_boost task"); 3083 boost_tasks[cpu] = kthread_run_on_cpu(rcu_torture_boost, NULL, 3084 cpu, "rcu_torture_boost_%u"); 3085 if (IS_ERR(boost_tasks[cpu])) { 3086 retval = PTR_ERR(boost_tasks[cpu]); 3087 VERBOSE_TOROUT_STRING("rcu_torture_boost task create failed"); 3088 n_rcu_torture_boost_ktrerror++; 3089 boost_tasks[cpu] = NULL; 3090 mutex_unlock(&boost_mutex); 3091 return retval; 3092 } 3093 mutex_unlock(&boost_mutex); 3094 return 0; 3095 } 3096 3097 static int rcu_torture_stall_nf(struct notifier_block *nb, unsigned long v, void *ptr) 3098 { 3099 pr_info("%s: v=%lu, duration=%lu.\n", __func__, v, (unsigned long)ptr); 3100 return NOTIFY_OK; 3101 } 3102 3103 static struct notifier_block rcu_torture_stall_block = { 3104 .notifier_call = rcu_torture_stall_nf, 3105 }; 3106 3107 /* 3108 * CPU-stall kthread. It waits as specified by stall_cpu_holdoff, then 3109 * induces a CPU stall for the time specified by stall_cpu. If a new 3110 * stall test is added, stallsdone in rcu_torture_writer() must be adjusted. 3111 */ 3112 static void rcu_torture_stall_one(int rep, int irqsoff) 3113 { 3114 int idx; 3115 unsigned long stop_at; 3116 3117 if (stall_cpu_holdoff > 0) { 3118 VERBOSE_TOROUT_STRING("rcu_torture_stall begin holdoff"); 3119 schedule_timeout_interruptible(stall_cpu_holdoff * HZ); 3120 VERBOSE_TOROUT_STRING("rcu_torture_stall end holdoff"); 3121 } 3122 if (!kthread_should_stop() && stall_gp_kthread > 0) { 3123 VERBOSE_TOROUT_STRING("rcu_torture_stall begin GP stall"); 3124 rcu_gp_set_torture_wait(stall_gp_kthread * HZ); 3125 for (idx = 0; idx < stall_gp_kthread + 2; idx++) { 3126 if (kthread_should_stop()) 3127 break; 3128 schedule_timeout_uninterruptible(HZ); 3129 } 3130 } 3131 if (!kthread_should_stop() && stall_cpu > 0) { 3132 VERBOSE_TOROUT_STRING("rcu_torture_stall begin CPU stall"); 3133 stop_at = ktime_get_seconds() + stall_cpu; 3134 /* RCU CPU stall is expected behavior in following code. */ 3135 idx = cur_ops->readlock(); 3136 if (irqsoff) 3137 local_irq_disable(); 3138 else if (!stall_cpu_block) 3139 preempt_disable(); 3140 pr_alert("%s start stall episode %d on CPU %d.\n", 3141 __func__, rep + 1, raw_smp_processor_id()); 3142 while (ULONG_CMP_LT((unsigned long)ktime_get_seconds(), stop_at) && 3143 !kthread_should_stop()) 3144 if (stall_cpu_block) { 3145 #ifdef CONFIG_PREEMPTION 3146 preempt_schedule(); 3147 #else 3148 schedule_timeout_uninterruptible(HZ); 3149 #endif 3150 } else if (stall_no_softlockup) { 3151 touch_softlockup_watchdog(); 3152 } 3153 if (irqsoff) 3154 local_irq_enable(); 3155 else if (!stall_cpu_block) 3156 preempt_enable(); 3157 cur_ops->readunlock(idx); 3158 } 3159 } 3160 3161 /* 3162 * CPU-stall kthread. Invokes rcu_torture_stall_one() once, and then as many 3163 * additional times as specified by the stall_cpu_repeat module parameter. 3164 * Note that stall_cpu_irqsoff is ignored on the second and subsequent 3165 * stall. 3166 */ 3167 static int rcu_torture_stall(void *args) 3168 { 3169 int i; 3170 int repeat = stall_cpu_repeat; 3171 int ret; 3172 3173 VERBOSE_TOROUT_STRING("rcu_torture_stall task started"); 3174 if (repeat < 0) { 3175 repeat = 0; 3176 WARN_ON_ONCE(IS_BUILTIN(CONFIG_RCU_TORTURE_TEST)); 3177 } 3178 if (rcu_cpu_stall_notifiers) { 3179 ret = rcu_stall_chain_notifier_register(&rcu_torture_stall_block); 3180 if (ret) 3181 pr_info("%s: rcu_stall_chain_notifier_register() returned %d, %sexpected.\n", 3182 __func__, ret, !IS_ENABLED(CONFIG_RCU_STALL_COMMON) ? "un" : ""); 3183 } 3184 for (i = 0; i <= repeat; i++) { 3185 if (kthread_should_stop()) 3186 break; 3187 rcu_torture_stall_one(i, i == 0 ? stall_cpu_irqsoff : 0); 3188 } 3189 pr_alert("%s end.\n", __func__); 3190 if (rcu_cpu_stall_notifiers && !ret) { 3191 ret = rcu_stall_chain_notifier_unregister(&rcu_torture_stall_block); 3192 if (ret) 3193 pr_info("%s: rcu_stall_chain_notifier_unregister() returned %d.\n", __func__, ret); 3194 } 3195 torture_shutdown_absorb("rcu_torture_stall"); 3196 while (!kthread_should_stop()) 3197 schedule_timeout_interruptible(10 * HZ); 3198 return 0; 3199 } 3200 3201 /* Spawn CPU-stall kthread, if stall_cpu specified. */ 3202 static int __init rcu_torture_stall_init(void) 3203 { 3204 if (stall_cpu <= 0 && stall_gp_kthread <= 0) 3205 return 0; 3206 return torture_create_kthread(rcu_torture_stall, NULL, stall_task); 3207 } 3208 3209 /* State structure for forward-progress self-propagating RCU callback. */ 3210 struct fwd_cb_state { 3211 struct rcu_head rh; 3212 int stop; 3213 }; 3214 3215 /* 3216 * Forward-progress self-propagating RCU callback function. Because 3217 * callbacks run from softirq, this function is an implicit RCU read-side 3218 * critical section. 3219 */ 3220 static void rcu_torture_fwd_prog_cb(struct rcu_head *rhp) 3221 { 3222 struct fwd_cb_state *fcsp = container_of(rhp, struct fwd_cb_state, rh); 3223 3224 if (READ_ONCE(fcsp->stop)) { 3225 WRITE_ONCE(fcsp->stop, 2); 3226 return; 3227 } 3228 cur_ops->call(&fcsp->rh, rcu_torture_fwd_prog_cb); 3229 } 3230 3231 /* State for continuous-flood RCU callbacks. */ 3232 struct rcu_fwd_cb { 3233 struct rcu_head rh; 3234 struct rcu_fwd_cb *rfc_next; 3235 struct rcu_fwd *rfc_rfp; 3236 int rfc_gps; 3237 }; 3238 3239 #define MAX_FWD_CB_JIFFIES (8 * HZ) /* Maximum CB test duration. */ 3240 #define MIN_FWD_CB_LAUNDERS 3 /* This many CB invocations to count. */ 3241 #define MIN_FWD_CBS_LAUNDERED 100 /* Number of counted CBs. */ 3242 #define FWD_CBS_HIST_DIV 10 /* Histogram buckets/second. */ 3243 #define N_LAUNDERS_HIST (2 * MAX_FWD_CB_JIFFIES / (HZ / FWD_CBS_HIST_DIV)) 3244 3245 struct rcu_launder_hist { 3246 long n_launders; 3247 unsigned long launder_gp_seq; 3248 }; 3249 3250 struct rcu_fwd { 3251 spinlock_t rcu_fwd_lock; 3252 struct rcu_fwd_cb *rcu_fwd_cb_head; 3253 struct rcu_fwd_cb **rcu_fwd_cb_tail; 3254 long n_launders_cb; 3255 unsigned long rcu_fwd_startat; 3256 struct rcu_launder_hist n_launders_hist[N_LAUNDERS_HIST]; 3257 unsigned long rcu_launder_gp_seq_start; 3258 int rcu_fwd_id; 3259 }; 3260 3261 static DEFINE_MUTEX(rcu_fwd_mutex); 3262 static struct rcu_fwd *rcu_fwds; 3263 static unsigned long rcu_fwd_seq; 3264 static atomic_long_t rcu_fwd_max_cbs; 3265 static bool rcu_fwd_emergency_stop; 3266 3267 static void rcu_torture_fwd_cb_hist(struct rcu_fwd *rfp) 3268 { 3269 unsigned long gps; 3270 unsigned long gps_old; 3271 int i; 3272 int j; 3273 3274 for (i = ARRAY_SIZE(rfp->n_launders_hist) - 1; i > 0; i--) 3275 if (rfp->n_launders_hist[i].n_launders > 0) 3276 break; 3277 pr_alert("%s: Callback-invocation histogram %d (duration %lu jiffies):", 3278 __func__, rfp->rcu_fwd_id, jiffies - rfp->rcu_fwd_startat); 3279 gps_old = rfp->rcu_launder_gp_seq_start; 3280 for (j = 0; j <= i; j++) { 3281 gps = rfp->n_launders_hist[j].launder_gp_seq; 3282 pr_cont(" %ds/%d: %ld:%ld", 3283 j + 1, FWD_CBS_HIST_DIV, 3284 rfp->n_launders_hist[j].n_launders, 3285 rcutorture_seq_diff(gps, gps_old)); 3286 gps_old = gps; 3287 } 3288 pr_cont("\n"); 3289 } 3290 3291 /* Callback function for continuous-flood RCU callbacks. */ 3292 static void rcu_torture_fwd_cb_cr(struct rcu_head *rhp) 3293 { 3294 unsigned long flags; 3295 int i; 3296 struct rcu_fwd_cb *rfcp = container_of(rhp, struct rcu_fwd_cb, rh); 3297 struct rcu_fwd_cb **rfcpp; 3298 struct rcu_fwd *rfp = rfcp->rfc_rfp; 3299 3300 rfcp->rfc_next = NULL; 3301 rfcp->rfc_gps++; 3302 spin_lock_irqsave(&rfp->rcu_fwd_lock, flags); 3303 rfcpp = rfp->rcu_fwd_cb_tail; 3304 rfp->rcu_fwd_cb_tail = &rfcp->rfc_next; 3305 smp_store_release(rfcpp, rfcp); 3306 WRITE_ONCE(rfp->n_launders_cb, rfp->n_launders_cb + 1); 3307 i = ((jiffies - rfp->rcu_fwd_startat) / (HZ / FWD_CBS_HIST_DIV)); 3308 if (i >= ARRAY_SIZE(rfp->n_launders_hist)) 3309 i = ARRAY_SIZE(rfp->n_launders_hist) - 1; 3310 rfp->n_launders_hist[i].n_launders++; 3311 rfp->n_launders_hist[i].launder_gp_seq = cur_ops->get_gp_seq(); 3312 spin_unlock_irqrestore(&rfp->rcu_fwd_lock, flags); 3313 } 3314 3315 // Give the scheduler a chance, even on nohz_full CPUs. 3316 static void rcu_torture_fwd_prog_cond_resched(unsigned long iter) 3317 { 3318 if (IS_ENABLED(CONFIG_PREEMPTION) && IS_ENABLED(CONFIG_NO_HZ_FULL)) { 3319 // Real call_rcu() floods hit userspace, so emulate that. 3320 if (need_resched() || (iter & 0xfff)) 3321 schedule(); 3322 return; 3323 } 3324 // No userspace emulation: CB invocation throttles call_rcu() 3325 cond_resched(); 3326 } 3327 3328 /* 3329 * Free all callbacks on the rcu_fwd_cb_head list, either because the 3330 * test is over or because we hit an OOM event. 3331 */ 3332 static unsigned long rcu_torture_fwd_prog_cbfree(struct rcu_fwd *rfp) 3333 { 3334 unsigned long flags; 3335 unsigned long freed = 0; 3336 struct rcu_fwd_cb *rfcp; 3337 3338 for (;;) { 3339 spin_lock_irqsave(&rfp->rcu_fwd_lock, flags); 3340 rfcp = rfp->rcu_fwd_cb_head; 3341 if (!rfcp) { 3342 spin_unlock_irqrestore(&rfp->rcu_fwd_lock, flags); 3343 break; 3344 } 3345 rfp->rcu_fwd_cb_head = rfcp->rfc_next; 3346 if (!rfp->rcu_fwd_cb_head) 3347 rfp->rcu_fwd_cb_tail = &rfp->rcu_fwd_cb_head; 3348 spin_unlock_irqrestore(&rfp->rcu_fwd_lock, flags); 3349 kfree(rfcp); 3350 freed++; 3351 rcu_torture_fwd_prog_cond_resched(freed); 3352 if (tick_nohz_full_enabled()) { 3353 local_irq_save(flags); 3354 rcu_momentary_eqs(); 3355 local_irq_restore(flags); 3356 } 3357 } 3358 return freed; 3359 } 3360 3361 /* Carry out need_resched()/cond_resched() forward-progress testing. */ 3362 static void rcu_torture_fwd_prog_nr(struct rcu_fwd *rfp, 3363 int *tested, int *tested_tries) 3364 { 3365 unsigned long cver; 3366 unsigned long dur; 3367 struct fwd_cb_state fcs; 3368 unsigned long gps; 3369 int idx; 3370 int sd; 3371 int sd4; 3372 bool selfpropcb = false; 3373 unsigned long stopat; 3374 static DEFINE_TORTURE_RANDOM(trs); 3375 3376 pr_alert("%s: Starting forward-progress test %d\n", __func__, rfp->rcu_fwd_id); 3377 if (!cur_ops->sync) 3378 return; // Cannot do need_resched() forward progress testing without ->sync. 3379 if (cur_ops->call && cur_ops->cb_barrier) { 3380 init_rcu_head_on_stack(&fcs.rh); 3381 selfpropcb = true; 3382 } 3383 3384 /* Tight loop containing cond_resched(). */ 3385 atomic_inc(&rcu_fwd_cb_nodelay); 3386 cur_ops->sync(); /* Later readers see above write. */ 3387 if (selfpropcb) { 3388 WRITE_ONCE(fcs.stop, 0); 3389 cur_ops->call(&fcs.rh, rcu_torture_fwd_prog_cb); 3390 } 3391 cver = READ_ONCE(rcu_torture_current_version); 3392 gps = cur_ops->get_gp_seq(); 3393 sd = cur_ops->stall_dur() + 1; 3394 sd4 = (sd + fwd_progress_div - 1) / fwd_progress_div; 3395 dur = sd4 + torture_random(&trs) % (sd - sd4); 3396 WRITE_ONCE(rfp->rcu_fwd_startat, jiffies); 3397 stopat = rfp->rcu_fwd_startat + dur; 3398 while (time_before(jiffies, stopat) && 3399 !shutdown_time_arrived() && 3400 !READ_ONCE(rcu_fwd_emergency_stop) && !torture_must_stop()) { 3401 idx = cur_ops->readlock(); 3402 udelay(10); 3403 cur_ops->readunlock(idx); 3404 if (!fwd_progress_need_resched || need_resched()) 3405 cond_resched(); 3406 } 3407 (*tested_tries)++; 3408 if (!time_before(jiffies, stopat) && 3409 !shutdown_time_arrived() && 3410 !READ_ONCE(rcu_fwd_emergency_stop) && !torture_must_stop()) { 3411 (*tested)++; 3412 cver = READ_ONCE(rcu_torture_current_version) - cver; 3413 gps = rcutorture_seq_diff(cur_ops->get_gp_seq(), gps); 3414 WARN_ON(!cver && gps < 2); 3415 pr_alert("%s: %d Duration %ld cver %ld gps %ld\n", __func__, 3416 rfp->rcu_fwd_id, dur, cver, gps); 3417 } 3418 if (selfpropcb) { 3419 WRITE_ONCE(fcs.stop, 1); 3420 cur_ops->sync(); /* Wait for running CB to complete. */ 3421 pr_alert("%s: Waiting for CBs: %pS() %d\n", __func__, cur_ops->cb_barrier, rfp->rcu_fwd_id); 3422 cur_ops->cb_barrier(); /* Wait for queued callbacks. */ 3423 } 3424 3425 if (selfpropcb) { 3426 WARN_ON(READ_ONCE(fcs.stop) != 2); 3427 destroy_rcu_head_on_stack(&fcs.rh); 3428 } 3429 schedule_timeout_uninterruptible(HZ / 10); /* Let kthreads recover. */ 3430 atomic_dec(&rcu_fwd_cb_nodelay); 3431 } 3432 3433 /* Carry out call_rcu() forward-progress testing. */ 3434 static void rcu_torture_fwd_prog_cr(struct rcu_fwd *rfp) 3435 { 3436 unsigned long cver; 3437 unsigned long flags; 3438 unsigned long gps; 3439 int i; 3440 long n_launders; 3441 long n_launders_cb_snap; 3442 long n_launders_sa; 3443 long n_max_cbs; 3444 long n_max_gps; 3445 struct rcu_fwd_cb *rfcp; 3446 struct rcu_fwd_cb *rfcpn; 3447 unsigned long stopat; 3448 unsigned long stoppedat; 3449 3450 pr_alert("%s: Starting forward-progress test %d\n", __func__, rfp->rcu_fwd_id); 3451 if (READ_ONCE(rcu_fwd_emergency_stop)) 3452 return; /* Get out of the way quickly, no GP wait! */ 3453 if (!cur_ops->call) 3454 return; /* Can't do call_rcu() fwd prog without ->call. */ 3455 3456 /* Loop continuously posting RCU callbacks. */ 3457 atomic_inc(&rcu_fwd_cb_nodelay); 3458 cur_ops->sync(); /* Later readers see above write. */ 3459 WRITE_ONCE(rfp->rcu_fwd_startat, jiffies); 3460 stopat = rfp->rcu_fwd_startat + MAX_FWD_CB_JIFFIES; 3461 n_launders = 0; 3462 rfp->n_launders_cb = 0; // Hoist initialization for multi-kthread 3463 n_launders_sa = 0; 3464 n_max_cbs = 0; 3465 n_max_gps = 0; 3466 for (i = 0; i < ARRAY_SIZE(rfp->n_launders_hist); i++) 3467 rfp->n_launders_hist[i].n_launders = 0; 3468 cver = READ_ONCE(rcu_torture_current_version); 3469 gps = cur_ops->get_gp_seq(); 3470 rfp->rcu_launder_gp_seq_start = gps; 3471 tick_dep_set_task(current, TICK_DEP_BIT_RCU); // CPU bound, so need tick. 3472 while (time_before(jiffies, stopat) && 3473 !shutdown_time_arrived() && 3474 !READ_ONCE(rcu_fwd_emergency_stop) && !torture_must_stop()) { 3475 rfcp = READ_ONCE(rfp->rcu_fwd_cb_head); 3476 rfcpn = NULL; 3477 if (rfcp) 3478 rfcpn = READ_ONCE(rfcp->rfc_next); 3479 if (rfcpn) { 3480 if (rfcp->rfc_gps >= MIN_FWD_CB_LAUNDERS && 3481 ++n_max_gps >= MIN_FWD_CBS_LAUNDERED) 3482 break; 3483 rfp->rcu_fwd_cb_head = rfcpn; 3484 n_launders++; 3485 n_launders_sa++; 3486 } else if (!cur_ops->cbflood_max || cur_ops->cbflood_max > n_max_cbs) { 3487 rfcp = kmalloc_obj(*rfcp); 3488 if (WARN_ON_ONCE(!rfcp)) { 3489 schedule_timeout_interruptible(1); 3490 continue; 3491 } 3492 n_max_cbs++; 3493 n_launders_sa = 0; 3494 rfcp->rfc_gps = 0; 3495 rfcp->rfc_rfp = rfp; 3496 } else { 3497 rfcp = NULL; 3498 } 3499 if (rfcp) 3500 cur_ops->call(&rfcp->rh, rcu_torture_fwd_cb_cr); 3501 rcu_torture_fwd_prog_cond_resched(n_launders + n_max_cbs); 3502 if (tick_nohz_full_enabled()) { 3503 local_irq_save(flags); 3504 rcu_momentary_eqs(); 3505 local_irq_restore(flags); 3506 } 3507 } 3508 stoppedat = jiffies; 3509 n_launders_cb_snap = READ_ONCE(rfp->n_launders_cb); 3510 cver = READ_ONCE(rcu_torture_current_version) - cver; 3511 gps = rcutorture_seq_diff(cur_ops->get_gp_seq(), gps); 3512 pr_alert("%s: Waiting for CBs: %pS() %d\n", __func__, cur_ops->cb_barrier, rfp->rcu_fwd_id); 3513 cur_ops->cb_barrier(); /* Wait for callbacks to be invoked. */ 3514 (void)rcu_torture_fwd_prog_cbfree(rfp); 3515 3516 if (!torture_must_stop() && !READ_ONCE(rcu_fwd_emergency_stop) && 3517 !shutdown_time_arrived()) { 3518 if (WARN_ON(n_max_gps < MIN_FWD_CBS_LAUNDERED) && cur_ops->gp_kthread_dbg) 3519 cur_ops->gp_kthread_dbg(); 3520 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", 3521 __func__, 3522 stoppedat - rfp->rcu_fwd_startat, jiffies - stoppedat, 3523 n_launders + n_max_cbs - n_launders_cb_snap, 3524 n_launders, n_launders_sa, 3525 n_max_gps, n_max_cbs, cver, gps, num_online_cpus()); 3526 atomic_long_add(n_max_cbs, &rcu_fwd_max_cbs); 3527 mutex_lock(&rcu_fwd_mutex); // Serialize histograms. 3528 rcu_torture_fwd_cb_hist(rfp); 3529 mutex_unlock(&rcu_fwd_mutex); 3530 } 3531 schedule_timeout_uninterruptible(HZ); /* Let CBs drain. */ 3532 tick_dep_clear_task(current, TICK_DEP_BIT_RCU); 3533 atomic_dec(&rcu_fwd_cb_nodelay); 3534 } 3535 3536 3537 /* 3538 * OOM notifier, but this only prints diagnostic information for the 3539 * current forward-progress test. 3540 */ 3541 static int rcutorture_oom_notify(struct notifier_block *self, 3542 unsigned long notused, void *nfreed) 3543 { 3544 int i; 3545 long ncbs; 3546 struct rcu_fwd *rfp; 3547 3548 mutex_lock(&rcu_fwd_mutex); 3549 rfp = rcu_fwds; 3550 if (!rfp) { 3551 mutex_unlock(&rcu_fwd_mutex); 3552 return NOTIFY_OK; 3553 } 3554 WARN(1, "%s invoked upon OOM during forward-progress testing.\n", 3555 __func__); 3556 for (i = 0; i < fwd_progress; i++) { 3557 rcu_torture_fwd_cb_hist(&rfp[i]); 3558 rcu_fwd_progress_check(1 + (jiffies - READ_ONCE(rfp[i].rcu_fwd_startat)) / 2); 3559 } 3560 WRITE_ONCE(rcu_fwd_emergency_stop, true); 3561 smp_mb(); /* Emergency stop before free and wait to avoid hangs. */ 3562 ncbs = 0; 3563 for (i = 0; i < fwd_progress; i++) 3564 ncbs += rcu_torture_fwd_prog_cbfree(&rfp[i]); 3565 pr_info("%s: Freed %lu RCU callbacks.\n", __func__, ncbs); 3566 cur_ops->cb_barrier(); 3567 ncbs = 0; 3568 for (i = 0; i < fwd_progress; i++) 3569 ncbs += rcu_torture_fwd_prog_cbfree(&rfp[i]); 3570 pr_info("%s: Freed %lu RCU callbacks.\n", __func__, ncbs); 3571 cur_ops->cb_barrier(); 3572 ncbs = 0; 3573 for (i = 0; i < fwd_progress; i++) 3574 ncbs += rcu_torture_fwd_prog_cbfree(&rfp[i]); 3575 pr_info("%s: Freed %lu RCU callbacks.\n", __func__, ncbs); 3576 smp_mb(); /* Frees before return to avoid redoing OOM. */ 3577 (*(unsigned long *)nfreed)++; /* Forward progress CBs freed! */ 3578 pr_info("%s returning after OOM processing.\n", __func__); 3579 mutex_unlock(&rcu_fwd_mutex); 3580 return NOTIFY_OK; 3581 } 3582 3583 static struct notifier_block rcutorture_oom_nb = { 3584 .notifier_call = rcutorture_oom_notify 3585 }; 3586 3587 /* Carry out grace-period forward-progress testing. */ 3588 static int rcu_torture_fwd_prog(void *args) 3589 { 3590 bool firsttime = true; 3591 long max_cbs; 3592 int oldnice = task_nice(current); 3593 unsigned long oldseq = READ_ONCE(rcu_fwd_seq); 3594 struct rcu_fwd *rfp = args; 3595 int tested = 0; 3596 int tested_tries = 0; 3597 3598 VERBOSE_TOROUT_STRING("rcu_torture_fwd_progress task started"); 3599 while (!rcu_inkernel_boot_has_ended()) 3600 schedule_timeout_interruptible(HZ / 10); 3601 rcu_bind_current_to_nocb(); 3602 if (!IS_ENABLED(CONFIG_SMP) || !IS_ENABLED(CONFIG_RCU_BOOST)) 3603 set_user_nice(current, MAX_NICE); 3604 do { 3605 if (!rfp->rcu_fwd_id) { 3606 schedule_timeout_interruptible(fwd_progress_holdoff * HZ); 3607 WRITE_ONCE(rcu_fwd_emergency_stop, false); 3608 if (!firsttime) { 3609 max_cbs = atomic_long_xchg(&rcu_fwd_max_cbs, 0); 3610 pr_alert("%s n_max_cbs: %ld\n", __func__, max_cbs); 3611 } 3612 firsttime = false; 3613 WRITE_ONCE(rcu_fwd_seq, rcu_fwd_seq + 1); 3614 } else { 3615 while (READ_ONCE(rcu_fwd_seq) == oldseq && !torture_must_stop()) 3616 schedule_timeout_interruptible(HZ / 20); 3617 oldseq = READ_ONCE(rcu_fwd_seq); 3618 } 3619 pr_alert("%s: Starting forward-progress test %d\n", __func__, rfp->rcu_fwd_id); 3620 if (rcu_inkernel_boot_has_ended() && torture_num_online_cpus() > rfp->rcu_fwd_id) 3621 rcu_torture_fwd_prog_cr(rfp); 3622 if ((cur_ops->stall_dur && cur_ops->stall_dur() > 0) && 3623 (!IS_ENABLED(CONFIG_TINY_RCU) || 3624 (rcu_inkernel_boot_has_ended() && 3625 torture_num_online_cpus() > rfp->rcu_fwd_id))) 3626 rcu_torture_fwd_prog_nr(rfp, &tested, &tested_tries); 3627 3628 /* Avoid slow periods, better to test when busy. */ 3629 if (stutter_wait("rcu_torture_fwd_prog")) 3630 sched_set_normal(current, oldnice); 3631 } while (!torture_must_stop()); 3632 /* Short runs might not contain a valid forward-progress attempt. */ 3633 if (!rfp->rcu_fwd_id) { 3634 WARN_ON(!tested && tested_tries >= 5); 3635 pr_alert("%s: tested %d tested_tries %d\n", __func__, tested, tested_tries); 3636 } 3637 torture_kthread_stopping("rcu_torture_fwd_prog"); 3638 return 0; 3639 } 3640 3641 /* If forward-progress checking is requested and feasible, spawn the thread. */ 3642 static int __init rcu_torture_fwd_prog_init(void) 3643 { 3644 int i; 3645 int ret = 0; 3646 struct rcu_fwd *rfp; 3647 3648 if (!fwd_progress) 3649 return 0; /* Not requested, so don't do it. */ 3650 if (fwd_progress >= nr_cpu_ids) { 3651 VERBOSE_TOROUT_STRING("rcu_torture_fwd_prog_init: Limiting fwd_progress to # CPUs.\n"); 3652 fwd_progress = nr_cpu_ids; 3653 } else if (fwd_progress < 0) { 3654 fwd_progress = nr_cpu_ids; 3655 } 3656 if ((!cur_ops->sync && !cur_ops->call) || 3657 (!cur_ops->cbflood_max && (!cur_ops->stall_dur || cur_ops->stall_dur() <= 0)) || 3658 cur_ops == &rcu_busted_ops) { 3659 VERBOSE_TOROUT_STRING("rcu_torture_fwd_prog_init: Disabled, unsupported by RCU flavor under test"); 3660 fwd_progress = 0; 3661 return 0; 3662 } 3663 if (stall_cpu > 0 || (preempt_duration > 0 && IS_ENABLED(CONFIG_RCU_NOCB_CPU))) { 3664 VERBOSE_TOROUT_STRING("rcu_torture_fwd_prog_init: Disabled, conflicts with CPU-stall and/or preemption testing"); 3665 fwd_progress = 0; 3666 if (IS_MODULE(CONFIG_RCU_TORTURE_TEST)) 3667 return -EINVAL; /* In module, can fail back to user. */ 3668 WARN_ON(1); /* Make sure rcutorture scripting notices conflict. */ 3669 return 0; 3670 } 3671 if (fwd_progress_holdoff <= 0) 3672 fwd_progress_holdoff = 1; 3673 if (fwd_progress_div <= 0) 3674 fwd_progress_div = 4; 3675 rfp = kzalloc_objs(*rfp, fwd_progress); 3676 fwd_prog_tasks = kzalloc_objs(*fwd_prog_tasks, fwd_progress); 3677 if (!rfp || !fwd_prog_tasks) { 3678 kfree(rfp); 3679 kfree(fwd_prog_tasks); 3680 fwd_prog_tasks = NULL; 3681 fwd_progress = 0; 3682 return -ENOMEM; 3683 } 3684 for (i = 0; i < fwd_progress; i++) { 3685 spin_lock_init(&rfp[i].rcu_fwd_lock); 3686 rfp[i].rcu_fwd_cb_tail = &rfp[i].rcu_fwd_cb_head; 3687 rfp[i].rcu_fwd_id = i; 3688 } 3689 mutex_lock(&rcu_fwd_mutex); 3690 rcu_fwds = rfp; 3691 mutex_unlock(&rcu_fwd_mutex); 3692 register_oom_notifier(&rcutorture_oom_nb); 3693 for (i = 0; i < fwd_progress; i++) { 3694 ret = torture_create_kthread(rcu_torture_fwd_prog, &rcu_fwds[i], fwd_prog_tasks[i]); 3695 if (ret) { 3696 fwd_progress = i; 3697 return ret; 3698 } 3699 } 3700 return 0; 3701 } 3702 3703 static void rcu_torture_fwd_prog_cleanup(void) 3704 { 3705 int i; 3706 struct rcu_fwd *rfp; 3707 3708 if (!rcu_fwds || !fwd_prog_tasks) 3709 return; 3710 for (i = 0; i < fwd_progress; i++) 3711 torture_stop_kthread(rcu_torture_fwd_prog, fwd_prog_tasks[i]); 3712 unregister_oom_notifier(&rcutorture_oom_nb); 3713 mutex_lock(&rcu_fwd_mutex); 3714 rfp = rcu_fwds; 3715 rcu_fwds = NULL; 3716 mutex_unlock(&rcu_fwd_mutex); 3717 kfree(rfp); 3718 kfree(fwd_prog_tasks); 3719 fwd_prog_tasks = NULL; 3720 } 3721 3722 /* Callback function for RCU barrier testing. */ 3723 static void rcu_torture_barrier_cbf(struct rcu_head *rcu) 3724 { 3725 atomic_inc(&barrier_cbs_invoked); 3726 } 3727 3728 /* IPI handler to get callback posted on desired CPU, if online. */ 3729 static int rcu_torture_barrier1cb(void *rcu_void) 3730 { 3731 struct rcu_head *rhp = rcu_void; 3732 3733 cur_ops->call(rhp, rcu_torture_barrier_cbf); 3734 return 0; 3735 } 3736 3737 /* kthread function to register callbacks used to test RCU barriers. */ 3738 static int rcu_torture_barrier_cbs(void *arg) 3739 { 3740 long myid = (long)arg; 3741 bool lastphase = false; 3742 bool newphase; 3743 struct rcu_head rcu; 3744 3745 init_rcu_head_on_stack(&rcu); 3746 VERBOSE_TOROUT_STRING("rcu_torture_barrier_cbs task started"); 3747 set_user_nice(current, MAX_NICE); 3748 do { 3749 wait_event(barrier_cbs_wq[myid], 3750 (newphase = 3751 smp_load_acquire(&barrier_phase)) != lastphase || 3752 torture_must_stop()); 3753 lastphase = newphase; 3754 if (torture_must_stop()) 3755 break; 3756 /* 3757 * The above smp_load_acquire() ensures barrier_phase load 3758 * is ordered before the following ->call(). 3759 */ 3760 if (smp_call_on_cpu(myid, rcu_torture_barrier1cb, &rcu, 1)) 3761 cur_ops->call(&rcu, rcu_torture_barrier_cbf); 3762 3763 if (atomic_dec_and_test(&barrier_cbs_count)) 3764 wake_up(&barrier_wq); 3765 } while (!torture_must_stop()); 3766 if (cur_ops->cb_barrier != NULL) 3767 cur_ops->cb_barrier(); 3768 destroy_rcu_head_on_stack(&rcu); 3769 torture_kthread_stopping("rcu_torture_barrier_cbs"); 3770 return 0; 3771 } 3772 3773 /* kthread function to drive and coordinate RCU barrier testing. */ 3774 static int rcu_torture_barrier(void *arg) 3775 { 3776 int i; 3777 3778 VERBOSE_TOROUT_STRING("rcu_torture_barrier task starting"); 3779 do { 3780 atomic_set(&barrier_cbs_invoked, 0); 3781 atomic_set(&barrier_cbs_count, n_barrier_cbs); 3782 /* Ensure barrier_phase ordered after prior assignments. */ 3783 smp_store_release(&barrier_phase, !barrier_phase); 3784 for (i = 0; i < n_barrier_cbs; i++) 3785 wake_up(&barrier_cbs_wq[i]); 3786 wait_event(barrier_wq, 3787 atomic_read(&barrier_cbs_count) == 0 || 3788 torture_must_stop()); 3789 if (torture_must_stop()) 3790 break; 3791 n_barrier_attempts++; 3792 cur_ops->cb_barrier(); /* Implies smp_mb() for wait_event(). */ 3793 if (atomic_read(&barrier_cbs_invoked) != n_barrier_cbs) { 3794 n_rcu_torture_barrier_error++; 3795 pr_err("barrier_cbs_invoked = %d, n_barrier_cbs = %d\n", 3796 atomic_read(&barrier_cbs_invoked), 3797 n_barrier_cbs); 3798 WARN_ON(1); 3799 // Wait manually for the remaining callbacks 3800 i = 0; 3801 do { 3802 if (WARN_ON(i++ > HZ)) 3803 i = INT_MIN; 3804 schedule_timeout_interruptible(1); 3805 cur_ops->cb_barrier(); 3806 } while (atomic_read(&barrier_cbs_invoked) != 3807 n_barrier_cbs && 3808 !torture_must_stop()); 3809 smp_mb(); // Can't trust ordering if broken. 3810 if (!torture_must_stop()) 3811 pr_err("Recovered: barrier_cbs_invoked = %d\n", 3812 atomic_read(&barrier_cbs_invoked)); 3813 } else { 3814 n_barrier_successes++; 3815 } 3816 schedule_timeout_interruptible(HZ / 10); 3817 } while (!torture_must_stop()); 3818 torture_kthread_stopping("rcu_torture_barrier"); 3819 return 0; 3820 } 3821 3822 /* Initialize RCU barrier testing. */ 3823 static int rcu_torture_barrier_init(void) 3824 { 3825 int i; 3826 int ret; 3827 3828 if (n_barrier_cbs <= 0) 3829 return 0; 3830 if (cur_ops->call == NULL || cur_ops->cb_barrier == NULL) { 3831 pr_alert("%s" TORTURE_FLAG 3832 " Call or barrier ops missing for %s,\n", 3833 torture_type, cur_ops->name); 3834 pr_alert("%s" TORTURE_FLAG 3835 " RCU barrier testing omitted from run.\n", 3836 torture_type); 3837 return 0; 3838 } 3839 atomic_set(&barrier_cbs_count, 0); 3840 atomic_set(&barrier_cbs_invoked, 0); 3841 barrier_cbs_tasks = 3842 kzalloc_objs(barrier_cbs_tasks[0], n_barrier_cbs); 3843 barrier_cbs_wq = 3844 kzalloc_objs(barrier_cbs_wq[0], n_barrier_cbs); 3845 if (barrier_cbs_tasks == NULL || !barrier_cbs_wq) 3846 return -ENOMEM; 3847 for (i = 0; i < n_barrier_cbs; i++) { 3848 init_waitqueue_head(&barrier_cbs_wq[i]); 3849 ret = torture_create_kthread(rcu_torture_barrier_cbs, 3850 (void *)(long)i, 3851 barrier_cbs_tasks[i]); 3852 if (ret) 3853 return ret; 3854 } 3855 return torture_create_kthread(rcu_torture_barrier, NULL, barrier_task); 3856 } 3857 3858 /* Clean up after RCU barrier testing. */ 3859 static void rcu_torture_barrier_cleanup(void) 3860 { 3861 int i; 3862 3863 torture_stop_kthread(rcu_torture_barrier, barrier_task); 3864 if (barrier_cbs_tasks != NULL) { 3865 for (i = 0; i < n_barrier_cbs; i++) 3866 torture_stop_kthread(rcu_torture_barrier_cbs, 3867 barrier_cbs_tasks[i]); 3868 kfree(barrier_cbs_tasks); 3869 barrier_cbs_tasks = NULL; 3870 } 3871 if (barrier_cbs_wq != NULL) { 3872 kfree(barrier_cbs_wq); 3873 barrier_cbs_wq = NULL; 3874 } 3875 } 3876 3877 static bool rcu_torture_can_boost(void) 3878 { 3879 static int boost_warn_once; 3880 int prio; 3881 3882 if (!(test_boost == 1 && cur_ops->can_boost) && test_boost != 2) 3883 return false; 3884 if (!cur_ops->start_gp_poll || !cur_ops->poll_gp_state) 3885 return false; 3886 3887 prio = rcu_get_gp_kthreads_prio(); 3888 if (!prio) 3889 return false; 3890 3891 if (prio < 2) { 3892 if (boost_warn_once == 1) 3893 return false; 3894 3895 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); 3896 boost_warn_once = 1; 3897 return false; 3898 } 3899 3900 return true; 3901 } 3902 3903 static bool read_exit_child_stop; 3904 static bool read_exit_child_stopped; 3905 static wait_queue_head_t read_exit_wq; 3906 3907 // Child kthread which just does an rcutorture reader and exits. 3908 static int rcu_torture_read_exit_child(void *trsp_in) 3909 { 3910 struct torture_random_state *trsp = trsp_in; 3911 3912 set_user_nice(current, MAX_NICE); 3913 // Minimize time between reading and exiting. 3914 while (!kthread_should_stop()) 3915 schedule_timeout_uninterruptible(HZ / 20); 3916 (void)rcu_torture_one_read(trsp, -1); 3917 return 0; 3918 } 3919 3920 // Parent kthread which creates and destroys read-exit child kthreads. 3921 static int rcu_torture_read_exit(void *unused) 3922 { 3923 bool errexit = false; 3924 int i; 3925 struct task_struct *tsp; 3926 DEFINE_TORTURE_RANDOM(trs); 3927 3928 // Allocate and initialize. 3929 set_user_nice(current, MAX_NICE); 3930 VERBOSE_TOROUT_STRING("rcu_torture_read_exit: Start of test"); 3931 3932 // Each pass through this loop does one read-exit episode. 3933 do { 3934 VERBOSE_TOROUT_STRING("rcu_torture_read_exit: Start of episode"); 3935 for (i = 0; i < read_exit_burst; i++) { 3936 if (READ_ONCE(read_exit_child_stop)) 3937 break; 3938 stutter_wait("rcu_torture_read_exit"); 3939 // Spawn child. 3940 tsp = kthread_run(rcu_torture_read_exit_child, 3941 &trs, "%s", "rcu_torture_read_exit_child"); 3942 if (IS_ERR(tsp)) { 3943 TOROUT_ERRSTRING("out of memory"); 3944 errexit = true; 3945 break; 3946 } 3947 cond_resched(); 3948 kthread_stop(tsp); 3949 n_read_exits++; 3950 } 3951 VERBOSE_TOROUT_STRING("rcu_torture_read_exit: End of episode"); 3952 rcu_barrier(); // Wait for task_struct free, avoid OOM. 3953 i = 0; 3954 for (; !errexit && !READ_ONCE(read_exit_child_stop) && i < read_exit_delay; i++) 3955 schedule_timeout_uninterruptible(HZ); 3956 } while (!errexit && !READ_ONCE(read_exit_child_stop)); 3957 3958 // Clean up and exit. 3959 smp_store_release(&read_exit_child_stopped, true); // After reaping. 3960 smp_mb(); // Store before wakeup. 3961 wake_up(&read_exit_wq); 3962 while (!torture_must_stop()) 3963 schedule_timeout_uninterruptible(HZ / 20); 3964 torture_kthread_stopping("rcu_torture_read_exit"); 3965 return 0; 3966 } 3967 3968 static int rcu_torture_read_exit_init(void) 3969 { 3970 if (read_exit_burst <= 0) 3971 return 0; 3972 init_waitqueue_head(&read_exit_wq); 3973 read_exit_child_stop = false; 3974 read_exit_child_stopped = false; 3975 return torture_create_kthread(rcu_torture_read_exit, NULL, 3976 read_exit_task); 3977 } 3978 3979 static void rcu_torture_read_exit_cleanup(void) 3980 { 3981 if (!read_exit_task) 3982 return; 3983 WRITE_ONCE(read_exit_child_stop, true); 3984 smp_mb(); // Above write before wait. 3985 wait_event(read_exit_wq, smp_load_acquire(&read_exit_child_stopped)); 3986 torture_stop_kthread(rcutorture_read_exit, read_exit_task); 3987 } 3988 3989 static void rcutorture_test_nmis(int n) 3990 { 3991 #if IS_BUILTIN(CONFIG_RCU_TORTURE_TEST) 3992 int cpu; 3993 int dumpcpu; 3994 int i; 3995 3996 for (i = 0; i < n; i++) { 3997 preempt_disable(); 3998 cpu = smp_processor_id(); 3999 dumpcpu = cpu + 1; 4000 if (dumpcpu >= nr_cpu_ids) 4001 dumpcpu = 0; 4002 pr_alert("%s: CPU %d invoking dump_cpu_task(%d)\n", __func__, cpu, dumpcpu); 4003 dump_cpu_task(dumpcpu); 4004 preempt_enable(); 4005 schedule_timeout_uninterruptible(15 * HZ); 4006 } 4007 #else // #if IS_BUILTIN(CONFIG_RCU_TORTURE_TEST) 4008 WARN_ONCE(n, "Non-zero rcutorture.test_nmis=%d permitted only when rcutorture is built in.\n", test_nmis); 4009 #endif // #else // #if IS_BUILTIN(CONFIG_RCU_TORTURE_TEST) 4010 } 4011 4012 // Randomly preempt online CPUs. 4013 static int rcu_torture_preempt(void *unused) 4014 { 4015 int cpu = -1; 4016 DEFINE_TORTURE_RANDOM(rand); 4017 4018 schedule_timeout_idle(stall_cpu_holdoff); 4019 do { 4020 // Wait for preempt_interval ms with up to 100us fuzz. 4021 torture_hrtimeout_ms(preempt_interval, 100, &rand); 4022 // Select online CPU. 4023 cpu = cpumask_next(cpu, cpu_online_mask); 4024 if (cpu >= nr_cpu_ids) 4025 cpu = cpumask_next(-1, cpu_online_mask); 4026 WARN_ON_ONCE(cpu >= nr_cpu_ids); 4027 // Move to that CPU, if can't do so, retry later. 4028 if (torture_sched_setaffinity(current->pid, cpumask_of(cpu), false)) 4029 continue; 4030 // Preempt at high-ish priority, then reset to normal. 4031 sched_set_fifo(current); 4032 torture_sched_setaffinity(current->pid, cpu_present_mask, true); 4033 mdelay(preempt_duration); 4034 sched_set_normal(current, 0); 4035 stutter_wait("rcu_torture_preempt"); 4036 } while (!torture_must_stop()); 4037 torture_kthread_stopping("rcu_torture_preempt"); 4038 return 0; 4039 } 4040 4041 static enum cpuhp_state rcutor_hp; 4042 4043 static struct hrtimer gpwrap_lag_timer; 4044 static bool gpwrap_lag_active; 4045 4046 /* Timer handler for toggling RCU grace-period sequence overflow test lag value */ 4047 static enum hrtimer_restart rcu_gpwrap_lag_timer(struct hrtimer *timer) 4048 { 4049 ktime_t next_delay; 4050 4051 if (gpwrap_lag_active) { 4052 pr_alert("rcu-torture: Disabling gpwrap lag (value=0)\n"); 4053 cur_ops->set_gpwrap_lag(0); 4054 gpwrap_lag_active = false; 4055 next_delay = ktime_set((gpwrap_lag_cycle_mins - gpwrap_lag_active_mins) * 60, 0); 4056 } else { 4057 pr_alert("rcu-torture: Enabling gpwrap lag (value=%d)\n", gpwrap_lag_gps); 4058 cur_ops->set_gpwrap_lag(gpwrap_lag_gps); 4059 gpwrap_lag_active = true; 4060 next_delay = ktime_set(gpwrap_lag_active_mins * 60, 0); 4061 } 4062 4063 if (torture_must_stop_irq()) 4064 return HRTIMER_NORESTART; 4065 4066 hrtimer_forward_now(timer, next_delay); 4067 return HRTIMER_RESTART; 4068 } 4069 4070 static int rcu_gpwrap_lag_init(void) 4071 { 4072 if (!gpwrap_lag) 4073 return 0; 4074 4075 if (gpwrap_lag_cycle_mins <= 0 || gpwrap_lag_active_mins <= 0) { 4076 pr_alert("rcu-torture: lag timing parameters must be positive\n"); 4077 return -EINVAL; 4078 } 4079 4080 hrtimer_setup(&gpwrap_lag_timer, rcu_gpwrap_lag_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); 4081 gpwrap_lag_active = false; 4082 hrtimer_start(&gpwrap_lag_timer, 4083 ktime_set((gpwrap_lag_cycle_mins - gpwrap_lag_active_mins) * 60, 0), HRTIMER_MODE_REL); 4084 4085 return 0; 4086 } 4087 4088 static void rcu_gpwrap_lag_cleanup(void) 4089 { 4090 hrtimer_cancel(&gpwrap_lag_timer); 4091 cur_ops->set_gpwrap_lag(0); 4092 gpwrap_lag_active = false; 4093 } 4094 static void 4095 rcu_torture_cleanup(void) 4096 { 4097 int firsttime; 4098 int flags = 0; 4099 unsigned long gp_seq = 0; 4100 int i; 4101 int j; 4102 4103 if (torture_cleanup_begin()) { 4104 if (cur_ops->cb_barrier != NULL) { 4105 pr_info("%s: Invoking %pS().\n", __func__, cur_ops->cb_barrier); 4106 cur_ops->cb_barrier(); 4107 } 4108 if (cur_ops->gp_slow_unregister) 4109 cur_ops->gp_slow_unregister(NULL); 4110 return; 4111 } 4112 if (!cur_ops) { 4113 torture_cleanup_end(); 4114 return; 4115 } 4116 4117 rcutorture_test_nmis(test_nmis); 4118 4119 if (cur_ops->gp_kthread_dbg) 4120 cur_ops->gp_kthread_dbg(); 4121 torture_stop_kthread(rcu_torture_preempt, preempt_task); 4122 rcu_torture_read_exit_cleanup(); 4123 rcu_torture_barrier_cleanup(); 4124 rcu_torture_fwd_prog_cleanup(); 4125 torture_stop_kthread(rcu_torture_stall, stall_task); 4126 torture_stop_kthread(rcu_torture_writer, writer_task); 4127 4128 if (nocb_tasks) { 4129 for (i = 0; i < nrealnocbers; i++) 4130 torture_stop_kthread(rcu_nocb_toggle, nocb_tasks[i]); 4131 kfree(nocb_tasks); 4132 nocb_tasks = NULL; 4133 } 4134 4135 if (updown_task) { 4136 torture_stop_kthread(rcu_torture_updown, updown_task); 4137 updown_task = NULL; 4138 } 4139 if (reader_tasks) { 4140 for (i = 0; i < nrealreaders; i++) 4141 torture_stop_kthread(rcu_torture_reader, 4142 reader_tasks[i]); 4143 kfree(reader_tasks); 4144 reader_tasks = NULL; 4145 } 4146 kfree(rcu_torture_reader_mbchk); 4147 rcu_torture_reader_mbchk = NULL; 4148 4149 if (fakewriter_tasks) { 4150 for (i = 0; i < nrealfakewriters; i++) 4151 torture_stop_kthread(rcu_torture_fakewriter, 4152 fakewriter_tasks[i]); 4153 kfree(fakewriter_tasks); 4154 fakewriter_tasks = NULL; 4155 } 4156 4157 if (cur_ops->get_gp_data) 4158 cur_ops->get_gp_data(&flags, &gp_seq); 4159 pr_alert("%s: End-test grace-period state: g%ld f%#x total-gps=%ld\n", 4160 cur_ops->name, (long)gp_seq, flags, 4161 rcutorture_seq_diff(gp_seq, start_gp_seq)); 4162 torture_stop_kthread(rcu_torture_stats, stats_task); 4163 torture_stop_kthread(rcu_torture_fqs, fqs_task); 4164 if (rcu_torture_can_boost() && rcutor_hp >= 0) 4165 cpuhp_remove_state(rcutor_hp); 4166 4167 /* 4168 * Wait for all RCU callbacks to fire, then do torture-type-specific 4169 * cleanup operations. 4170 */ 4171 if (cur_ops->cb_barrier != NULL) { 4172 pr_info("%s: Invoking %pS().\n", __func__, cur_ops->cb_barrier); 4173 cur_ops->cb_barrier(); 4174 } 4175 if (cur_ops->cleanup != NULL) 4176 cur_ops->cleanup(); 4177 4178 rcu_torture_mem_dump_obj(); 4179 4180 rcu_torture_stats_print(); /* -After- the stats thread is stopped! */ 4181 4182 if (err_segs_recorded) { 4183 pr_alert("Failure/close-call rcutorture reader segments:\n"); 4184 if (rt_read_nsegs == 0) 4185 pr_alert("\t: No segments recorded!!!\n"); 4186 firsttime = 1; 4187 for (i = 0; i < rt_read_nsegs; i++) { 4188 if (IS_ENABLED(CONFIG_RCU_TORTURE_TEST_LOG_GP)) 4189 pr_alert("\t%lluus ", div64_u64(err_segs[i].rt_ts, 1000ULL)); 4190 else 4191 pr_alert("\t"); 4192 pr_cont("%d: %#4x", i, err_segs[i].rt_readstate); 4193 if (err_segs[i].rt_delay_jiffies != 0) { 4194 pr_cont("%s%ldjiffies", firsttime ? "" : "+", 4195 err_segs[i].rt_delay_jiffies); 4196 firsttime = 0; 4197 } 4198 if (IS_ENABLED(CONFIG_RCU_TORTURE_TEST_LOG_CPU)) { 4199 pr_cont(" CPU %2d", err_segs[i].rt_cpu); 4200 if (err_segs[i].rt_cpu != err_segs[i].rt_end_cpu) 4201 pr_cont("->%-2d", err_segs[i].rt_end_cpu); 4202 else 4203 pr_cont(" ..."); 4204 } 4205 if (IS_ENABLED(CONFIG_RCU_TORTURE_TEST_LOG_GP) && 4206 cur_ops->gather_gp_seqs && cur_ops->format_gp_seqs) { 4207 char buf1[20+1]; 4208 char buf2[20+1]; 4209 char sepchar = '-'; 4210 4211 cur_ops->format_gp_seqs(err_segs[i].rt_gp_seq, 4212 buf1, ARRAY_SIZE(buf1)); 4213 cur_ops->format_gp_seqs(err_segs[i].rt_gp_seq_end, 4214 buf2, ARRAY_SIZE(buf2)); 4215 if (err_segs[i].rt_gp_seq == err_segs[i].rt_gp_seq_end) { 4216 if (buf2[0]) { 4217 for (j = 0; buf2[j]; j++) 4218 buf2[j] = '.'; 4219 if (j) 4220 buf2[j - 1] = ' '; 4221 } 4222 sepchar = ' '; 4223 } 4224 pr_cont(" %s%c%s", buf1, sepchar, buf2); 4225 } 4226 if (err_segs[i].rt_delay_ms != 0) { 4227 pr_cont(" %s%ldms", firsttime ? "" : "+", 4228 err_segs[i].rt_delay_ms); 4229 firsttime = 0; 4230 } 4231 if (err_segs[i].rt_delay_us != 0) { 4232 pr_cont(" %s%ldus", firsttime ? "" : "+", 4233 err_segs[i].rt_delay_us); 4234 firsttime = 0; 4235 } 4236 pr_cont("%s", err_segs[i].rt_preempted ? " preempted" : ""); 4237 if (err_segs[i].rt_readstate & RCUTORTURE_RDR_BH) 4238 pr_cont(" BH"); 4239 if (err_segs[i].rt_readstate & RCUTORTURE_RDR_IRQ) 4240 pr_cont(" IRQ"); 4241 if (err_segs[i].rt_readstate & RCUTORTURE_RDR_PREEMPT) 4242 pr_cont(" PREEMPT"); 4243 if (err_segs[i].rt_readstate & RCUTORTURE_RDR_RBH) 4244 pr_cont(" RBH"); 4245 if (err_segs[i].rt_readstate & RCUTORTURE_RDR_SCHED) 4246 pr_cont(" SCHED"); 4247 if (err_segs[i].rt_readstate & RCUTORTURE_RDR_RCU_1) 4248 pr_cont(" RCU_1"); 4249 if (err_segs[i].rt_readstate & RCUTORTURE_RDR_RCU_2) 4250 pr_cont(" RCU_2"); 4251 pr_cont("\n"); 4252 4253 } 4254 if (rt_read_preempted) 4255 pr_alert("\tReader was preempted.\n"); 4256 } 4257 if (atomic_read(&n_rcu_torture_error) || n_rcu_torture_barrier_error) 4258 rcu_torture_print_module_parms(cur_ops, "End of test: FAILURE"); 4259 else if (torture_onoff_failures()) 4260 rcu_torture_print_module_parms(cur_ops, 4261 "End of test: RCU_HOTPLUG"); 4262 else 4263 rcu_torture_print_module_parms(cur_ops, "End of test: SUCCESS"); 4264 torture_cleanup_end(); 4265 if (cur_ops->gp_slow_unregister) 4266 cur_ops->gp_slow_unregister(NULL); 4267 4268 if (gpwrap_lag && cur_ops->set_gpwrap_lag) 4269 rcu_gpwrap_lag_cleanup(); 4270 } 4271 4272 static void rcu_torture_leak_cb(struct rcu_head *rhp) 4273 { 4274 } 4275 4276 static void rcu_torture_err_cb(struct rcu_head *rhp) 4277 { 4278 /* 4279 * This -might- happen due to race conditions, but is unlikely. 4280 * The scenario that leads to this happening is that the 4281 * first of the pair of duplicate callbacks is queued, 4282 * someone else starts a grace period that includes that 4283 * callback, then the second of the pair must wait for the 4284 * next grace period. Unlikely, but can happen. If it 4285 * does happen, the debug-objects subsystem won't have splatted. 4286 */ 4287 pr_alert("%s: duplicated callback was invoked.\n", KBUILD_MODNAME); 4288 } 4289 4290 /* 4291 * Verify that double-free causes debug-objects to complain, but only 4292 * if CONFIG_DEBUG_OBJECTS_RCU_HEAD=y. Otherwise, say that the test 4293 * cannot be carried out. 4294 */ 4295 static void rcu_test_debug_objects(void) 4296 { 4297 struct rcu_head rh1; 4298 struct rcu_head rh2; 4299 int idx; 4300 4301 if (!IS_ENABLED(CONFIG_DEBUG_OBJECTS_RCU_HEAD)) { 4302 pr_alert("%s: !CONFIG_DEBUG_OBJECTS_RCU_HEAD, not testing duplicate call_%s()\n", 4303 KBUILD_MODNAME, cur_ops->name); 4304 return; 4305 } 4306 4307 if (WARN_ON_ONCE(cur_ops->debug_objects && 4308 (!cur_ops->call || !cur_ops->cb_barrier))) 4309 return; 4310 4311 struct rcu_head *rhp = kmalloc_obj(*rhp); 4312 4313 init_rcu_head_on_stack(&rh1); 4314 init_rcu_head_on_stack(&rh2); 4315 pr_alert("%s: WARN: Duplicate call_%s() test starting.\n", KBUILD_MODNAME, cur_ops->name); 4316 4317 /* Try to queue the rh2 pair of callbacks for the same grace period. */ 4318 idx = cur_ops->readlock(); /* Make it impossible to finish a grace period. */ 4319 cur_ops->call(&rh1, rcu_torture_leak_cb); /* Start grace period. */ 4320 cur_ops->call(&rh2, rcu_torture_leak_cb); 4321 cur_ops->call(&rh2, rcu_torture_err_cb); /* Duplicate callback. */ 4322 if (rhp) { 4323 cur_ops->call(rhp, rcu_torture_leak_cb); 4324 cur_ops->call(rhp, rcu_torture_err_cb); /* Another duplicate callback. */ 4325 } 4326 cur_ops->readunlock(idx); 4327 4328 /* Wait for them all to get done so we can safely return. */ 4329 cur_ops->cb_barrier(); 4330 pr_alert("%s: WARN: Duplicate call_%s() test complete.\n", KBUILD_MODNAME, cur_ops->name); 4331 destroy_rcu_head_on_stack(&rh1); 4332 destroy_rcu_head_on_stack(&rh2); 4333 kfree(rhp); 4334 } 4335 4336 static void rcutorture_sync(void) 4337 { 4338 static unsigned long n; 4339 4340 if (cur_ops->sync && !(++n & 0xfff)) 4341 cur_ops->sync(); 4342 } 4343 4344 static DEFINE_MUTEX(mut0); 4345 static DEFINE_MUTEX(mut1); 4346 static DEFINE_MUTEX(mut2); 4347 static DEFINE_MUTEX(mut3); 4348 static DEFINE_MUTEX(mut4); 4349 static DEFINE_MUTEX(mut5); 4350 static DEFINE_MUTEX(mut6); 4351 static DEFINE_MUTEX(mut7); 4352 static DEFINE_MUTEX(mut8); 4353 static DEFINE_MUTEX(mut9); 4354 4355 static DECLARE_RWSEM(rwsem0); 4356 static DECLARE_RWSEM(rwsem1); 4357 static DECLARE_RWSEM(rwsem2); 4358 static DECLARE_RWSEM(rwsem3); 4359 static DECLARE_RWSEM(rwsem4); 4360 static DECLARE_RWSEM(rwsem5); 4361 static DECLARE_RWSEM(rwsem6); 4362 static DECLARE_RWSEM(rwsem7); 4363 static DECLARE_RWSEM(rwsem8); 4364 static DECLARE_RWSEM(rwsem9); 4365 4366 DEFINE_STATIC_SRCU(srcu0); 4367 DEFINE_STATIC_SRCU(srcu1); 4368 DEFINE_STATIC_SRCU(srcu2); 4369 DEFINE_STATIC_SRCU(srcu3); 4370 DEFINE_STATIC_SRCU(srcu4); 4371 DEFINE_STATIC_SRCU(srcu5); 4372 DEFINE_STATIC_SRCU(srcu6); 4373 DEFINE_STATIC_SRCU(srcu7); 4374 DEFINE_STATIC_SRCU(srcu8); 4375 DEFINE_STATIC_SRCU(srcu9); 4376 4377 static int srcu_lockdep_next(const char *f, const char *fl, const char *fs, const char *fu, int i, 4378 int cyclelen, int deadlock) 4379 { 4380 int j = i + 1; 4381 4382 if (j >= cyclelen) 4383 j = deadlock ? 0 : -1; 4384 if (j >= 0) 4385 pr_info("%s: %s(%d), %s(%d), %s(%d)\n", f, fl, i, fs, j, fu, i); 4386 else 4387 pr_info("%s: %s(%d), %s(%d)\n", f, fl, i, fu, i); 4388 return j; 4389 } 4390 4391 // Test lockdep on SRCU-based deadlock scenarios. 4392 static void rcu_torture_init_srcu_lockdep(void) 4393 { 4394 int cyclelen; 4395 int deadlock; 4396 bool err = false; 4397 int i; 4398 int j; 4399 int idx; 4400 struct mutex *muts[] = { &mut0, &mut1, &mut2, &mut3, &mut4, 4401 &mut5, &mut6, &mut7, &mut8, &mut9 }; 4402 struct rw_semaphore *rwsems[] = { &rwsem0, &rwsem1, &rwsem2, &rwsem3, &rwsem4, 4403 &rwsem5, &rwsem6, &rwsem7, &rwsem8, &rwsem9 }; 4404 struct srcu_struct *srcus[] = { &srcu0, &srcu1, &srcu2, &srcu3, &srcu4, 4405 &srcu5, &srcu6, &srcu7, &srcu8, &srcu9 }; 4406 int testtype; 4407 4408 if (!test_srcu_lockdep) 4409 return; 4410 4411 deadlock = test_srcu_lockdep / 1000; 4412 testtype = (test_srcu_lockdep / 10) % 100; 4413 cyclelen = test_srcu_lockdep % 10; 4414 WARN_ON_ONCE(ARRAY_SIZE(muts) != ARRAY_SIZE(srcus)); 4415 if (WARN_ONCE(deadlock != !!deadlock, 4416 "%s: test_srcu_lockdep=%d and deadlock digit %d must be zero or one.\n", 4417 __func__, test_srcu_lockdep, deadlock)) 4418 err = true; 4419 if (WARN_ONCE(cyclelen <= 0, 4420 "%s: test_srcu_lockdep=%d and cycle-length digit %d must be greater than zero.\n", 4421 __func__, test_srcu_lockdep, cyclelen)) 4422 err = true; 4423 if (err) 4424 goto err_out; 4425 4426 if (testtype == 0) { 4427 pr_info("%s: test_srcu_lockdep = %05d: SRCU %d-way %sdeadlock.\n", 4428 __func__, test_srcu_lockdep, cyclelen, deadlock ? "" : "non-"); 4429 if (deadlock && cyclelen == 1) 4430 pr_info("%s: Expect hang.\n", __func__); 4431 for (i = 0; i < cyclelen; i++) { 4432 j = srcu_lockdep_next(__func__, "srcu_read_lock", "synchronize_srcu", 4433 "srcu_read_unlock", i, cyclelen, deadlock); 4434 idx = srcu_read_lock(srcus[i]); 4435 if (j >= 0) 4436 synchronize_srcu(srcus[j]); 4437 srcu_read_unlock(srcus[i], idx); 4438 } 4439 return; 4440 } 4441 4442 if (testtype == 1) { 4443 pr_info("%s: test_srcu_lockdep = %05d: SRCU/mutex %d-way %sdeadlock.\n", 4444 __func__, test_srcu_lockdep, cyclelen, deadlock ? "" : "non-"); 4445 for (i = 0; i < cyclelen; i++) { 4446 pr_info("%s: srcu_read_lock(%d), mutex_lock(%d), mutex_unlock(%d), srcu_read_unlock(%d)\n", 4447 __func__, i, i, i, i); 4448 idx = srcu_read_lock(srcus[i]); 4449 mutex_lock(muts[i]); 4450 mutex_unlock(muts[i]); 4451 srcu_read_unlock(srcus[i], idx); 4452 4453 j = srcu_lockdep_next(__func__, "mutex_lock", "synchronize_srcu", 4454 "mutex_unlock", i, cyclelen, deadlock); 4455 mutex_lock(muts[i]); 4456 if (j >= 0) 4457 synchronize_srcu(srcus[j]); 4458 mutex_unlock(muts[i]); 4459 } 4460 return; 4461 } 4462 4463 if (testtype == 2) { 4464 pr_info("%s: test_srcu_lockdep = %05d: SRCU/rwsem %d-way %sdeadlock.\n", 4465 __func__, test_srcu_lockdep, cyclelen, deadlock ? "" : "non-"); 4466 for (i = 0; i < cyclelen; i++) { 4467 pr_info("%s: srcu_read_lock(%d), down_read(%d), up_read(%d), srcu_read_unlock(%d)\n", 4468 __func__, i, i, i, i); 4469 idx = srcu_read_lock(srcus[i]); 4470 down_read(rwsems[i]); 4471 up_read(rwsems[i]); 4472 srcu_read_unlock(srcus[i], idx); 4473 4474 j = srcu_lockdep_next(__func__, "down_write", "synchronize_srcu", 4475 "up_write", i, cyclelen, deadlock); 4476 down_write(rwsems[i]); 4477 if (j >= 0) 4478 synchronize_srcu(srcus[j]); 4479 up_write(rwsems[i]); 4480 } 4481 return; 4482 } 4483 4484 #ifdef CONFIG_TASKS_TRACE_RCU 4485 if (testtype == 3) { 4486 pr_info("%s: test_srcu_lockdep = %05d: SRCU and Tasks Trace RCU %d-way %sdeadlock.\n", 4487 __func__, test_srcu_lockdep, cyclelen, deadlock ? "" : "non-"); 4488 if (deadlock && cyclelen == 1) 4489 pr_info("%s: Expect hang.\n", __func__); 4490 for (i = 0; i < cyclelen; i++) { 4491 char *fl = i == 0 ? "rcu_read_lock_trace" : "srcu_read_lock"; 4492 char *fs = i == cyclelen - 1 ? "synchronize_rcu_tasks_trace" 4493 : "synchronize_srcu"; 4494 char *fu = i == 0 ? "rcu_read_unlock_trace" : "srcu_read_unlock"; 4495 4496 j = srcu_lockdep_next(__func__, fl, fs, fu, i, cyclelen, deadlock); 4497 if (i == 0) 4498 rcu_read_lock_trace(); 4499 else 4500 idx = srcu_read_lock(srcus[i]); 4501 if (j >= 0) { 4502 if (i == cyclelen - 1) 4503 synchronize_rcu_tasks_trace(); 4504 else 4505 synchronize_srcu(srcus[j]); 4506 } 4507 if (i == 0) 4508 rcu_read_unlock_trace(); 4509 else 4510 srcu_read_unlock(srcus[i], idx); 4511 } 4512 return; 4513 } 4514 #endif // #ifdef CONFIG_TASKS_TRACE_RCU 4515 4516 err_out: 4517 pr_info("%s: test_srcu_lockdep = %05d does nothing.\n", __func__, test_srcu_lockdep); 4518 pr_info("%s: test_srcu_lockdep = DNNL.\n", __func__); 4519 pr_info("%s: D: Deadlock if nonzero.\n", __func__); 4520 pr_info("%s: NN: Test number, 0=SRCU, 1=SRCU/mutex, 2=SRCU/rwsem, 3=SRCU/Tasks Trace RCU.\n", __func__); 4521 pr_info("%s: L: Cycle length.\n", __func__); 4522 if (!IS_ENABLED(CONFIG_TASKS_TRACE_RCU)) 4523 pr_info("%s: NN=3 disallowed because kernel is built with CONFIG_TASKS_TRACE_RCU=n\n", __func__); 4524 } 4525 4526 static int __init 4527 rcu_torture_init(void) 4528 { 4529 long i; 4530 int cpu; 4531 int firsterr = 0; 4532 int flags = 0; 4533 unsigned long gp_seq = 0; 4534 static struct rcu_torture_ops *torture_ops[] = { 4535 &rcu_ops, &rcu_busted_ops, &srcu_ops, &srcud_ops, &busted_srcud_ops, 4536 TASKS_OPS TASKS_RUDE_OPS TASKS_TRACING_OPS 4537 &trivial_ops, TRIVIAL_PREEMPT_OPS 4538 }; 4539 4540 if (!torture_init_begin(torture_type, verbose)) 4541 return -EBUSY; 4542 4543 /* Process args and tell the world that the torturer is on the job. */ 4544 for (i = 0; i < ARRAY_SIZE(torture_ops); i++) { 4545 cur_ops = torture_ops[i]; 4546 if (strcmp(torture_type, cur_ops->name) == 0) 4547 break; 4548 } 4549 if (i == ARRAY_SIZE(torture_ops)) { 4550 pr_alert("rcu-torture: invalid torture type: \"%s\"\n", 4551 torture_type); 4552 pr_alert("rcu-torture types:"); 4553 for (i = 0; i < ARRAY_SIZE(torture_ops); i++) 4554 pr_cont(" %s", torture_ops[i]->name); 4555 pr_cont("\n"); 4556 firsterr = -EINVAL; 4557 cur_ops = NULL; 4558 goto unwind; 4559 } 4560 if (cur_ops->fqs == NULL && fqs_duration != 0) { 4561 pr_alert("rcu-torture: ->fqs NULL and non-zero fqs_duration, fqs disabled.\n"); 4562 fqs_duration = 0; 4563 } 4564 if (nocbs_nthreads != 0 && (cur_ops != &rcu_ops || 4565 !IS_ENABLED(CONFIG_RCU_NOCB_CPU))) { 4566 pr_alert("rcu-torture types: %s and CONFIG_RCU_NOCB_CPU=%d, nocb toggle disabled.\n", 4567 cur_ops->name, IS_ENABLED(CONFIG_RCU_NOCB_CPU)); 4568 nocbs_nthreads = 0; 4569 } 4570 if (cur_ops->init) 4571 cur_ops->init(); 4572 4573 rcu_torture_init_srcu_lockdep(); 4574 4575 if (nfakewriters >= 0) { 4576 nrealfakewriters = nfakewriters; 4577 } else { 4578 nrealfakewriters = num_online_cpus() - 2 - nfakewriters; 4579 if (nrealfakewriters <= 0) 4580 nrealfakewriters = 1; 4581 } 4582 4583 if (nreaders >= 0) { 4584 nrealreaders = nreaders; 4585 } else { 4586 nrealreaders = num_online_cpus() - 2 - nreaders; 4587 if (nrealreaders <= 0) 4588 nrealreaders = 1; 4589 } 4590 rcu_torture_print_module_parms(cur_ops, "Start of test"); 4591 if (cur_ops->get_gp_data) 4592 cur_ops->get_gp_data(&flags, &gp_seq); 4593 start_gp_seq = gp_seq; 4594 pr_alert("%s: Start-test grace-period state: g%ld f%#x\n", 4595 cur_ops->name, (long)gp_seq, flags); 4596 4597 /* Set up the freelist. */ 4598 4599 INIT_LIST_HEAD(&rcu_torture_freelist); 4600 for (i = 0; i < ARRAY_SIZE(rcu_tortures); i++) { 4601 rcu_tortures[i].rtort_mbtest = 0; 4602 list_add_tail(&rcu_tortures[i].rtort_free, 4603 &rcu_torture_freelist); 4604 } 4605 4606 /* Initialize the statistics so that each run gets its own numbers. */ 4607 4608 rcu_torture_current = NULL; 4609 rcu_torture_current_version = 0; 4610 atomic_set(&n_rcu_torture_alloc, 0); 4611 atomic_set(&n_rcu_torture_alloc_fail, 0); 4612 atomic_set(&n_rcu_torture_free, 0); 4613 atomic_set(&n_rcu_torture_mberror, 0); 4614 atomic_set(&n_rcu_torture_mbchk_fail, 0); 4615 atomic_set(&n_rcu_torture_mbchk_tries, 0); 4616 atomic_set(&n_rcu_torture_error, 0); 4617 n_rcu_torture_barrier_error = 0; 4618 n_rcu_torture_boost_ktrerror = 0; 4619 n_rcu_torture_boost_failure = 0; 4620 n_rcu_torture_boosts = 0; 4621 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) 4622 atomic_set(&rcu_torture_wcount[i], 0); 4623 for_each_possible_cpu(cpu) { 4624 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) { 4625 per_cpu(rcu_torture_count, cpu)[i] = 0; 4626 per_cpu(rcu_torture_batch, cpu)[i] = 0; 4627 } 4628 } 4629 err_segs_recorded = 0; 4630 rt_read_nsegs = 0; 4631 4632 /* Start up the kthreads. */ 4633 4634 rcu_torture_write_types(); 4635 if (nrealfakewriters > 0) { 4636 fakewriter_tasks = kzalloc_objs(fakewriter_tasks[0], 4637 nrealfakewriters); 4638 if (fakewriter_tasks == NULL) { 4639 TOROUT_ERRSTRING("out of memory"); 4640 firsterr = -ENOMEM; 4641 goto unwind; 4642 } 4643 } 4644 for (i = 0; i < nrealfakewriters; i++) { 4645 firsterr = torture_create_kthread(rcu_torture_fakewriter, 4646 NULL, fakewriter_tasks[i]); 4647 if (torture_init_error(firsterr)) 4648 goto unwind; 4649 } 4650 reader_tasks = kzalloc_objs(reader_tasks[0], nrealreaders); 4651 rcu_torture_reader_mbchk = kzalloc_objs(*rcu_torture_reader_mbchk, 4652 nrealreaders); 4653 if (!reader_tasks || !rcu_torture_reader_mbchk) { 4654 TOROUT_ERRSTRING("out of memory"); 4655 firsterr = -ENOMEM; 4656 goto unwind; 4657 } 4658 for (i = 0; i < nrealreaders; i++) { 4659 rcu_torture_reader_mbchk[i].rtc_chkrdr = -1; 4660 firsterr = torture_create_kthread(rcu_torture_reader, (void *)i, 4661 reader_tasks[i]); 4662 if (torture_init_error(firsterr)) 4663 goto unwind; 4664 } 4665 4666 firsterr = torture_create_kthread(rcu_torture_writer, NULL, 4667 writer_task); 4668 if (torture_init_error(firsterr)) 4669 goto unwind; 4670 4671 firsterr = rcu_torture_updown_init(); 4672 if (torture_init_error(firsterr)) 4673 goto unwind; 4674 nrealnocbers = nocbs_nthreads; 4675 if (WARN_ON(nrealnocbers < 0)) 4676 nrealnocbers = 1; 4677 if (WARN_ON(nocbs_toggle < 0)) 4678 nocbs_toggle = HZ; 4679 if (nrealnocbers > 0) { 4680 nocb_tasks = kzalloc_objs(nocb_tasks[0], nrealnocbers); 4681 if (nocb_tasks == NULL) { 4682 TOROUT_ERRSTRING("out of memory"); 4683 firsterr = -ENOMEM; 4684 goto unwind; 4685 } 4686 } else { 4687 nocb_tasks = NULL; 4688 } 4689 for (i = 0; i < nrealnocbers; i++) { 4690 firsterr = torture_create_kthread(rcu_nocb_toggle, NULL, nocb_tasks[i]); 4691 if (torture_init_error(firsterr)) 4692 goto unwind; 4693 } 4694 if (stat_interval > 0) { 4695 firsterr = torture_create_kthread(rcu_torture_stats, NULL, 4696 stats_task); 4697 if (torture_init_error(firsterr)) 4698 goto unwind; 4699 } 4700 if (test_no_idle_hz && shuffle_interval > 0) { 4701 firsterr = torture_shuffle_init(shuffle_interval * HZ); 4702 if (torture_init_error(firsterr)) 4703 goto unwind; 4704 } 4705 if (stutter < 0) 4706 stutter = 0; 4707 if (stutter) { 4708 int t; 4709 4710 t = cur_ops->stall_dur ? cur_ops->stall_dur() : stutter * HZ; 4711 firsterr = torture_stutter_init(stutter * HZ, t); 4712 if (torture_init_error(firsterr)) 4713 goto unwind; 4714 } 4715 if (fqs_duration < 0) 4716 fqs_duration = 0; 4717 if (fqs_holdoff < 0) 4718 fqs_holdoff = 0; 4719 if (fqs_duration && fqs_holdoff) { 4720 /* Create the fqs thread */ 4721 firsterr = torture_create_kthread(rcu_torture_fqs, NULL, 4722 fqs_task); 4723 if (torture_init_error(firsterr)) 4724 goto unwind; 4725 } 4726 if (test_boost_interval < 1) 4727 test_boost_interval = 1; 4728 if (test_boost_duration < 2) 4729 test_boost_duration = 2; 4730 if (rcu_torture_can_boost()) { 4731 4732 boost_starttime = jiffies + test_boost_interval * HZ; 4733 4734 firsterr = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "RCU_TORTURE", 4735 rcutorture_booster_init, 4736 rcutorture_booster_cleanup); 4737 rcutor_hp = firsterr; 4738 if (torture_init_error(firsterr)) 4739 goto unwind; 4740 } 4741 shutdown_jiffies = jiffies + shutdown_secs * HZ; 4742 firsterr = torture_shutdown_init(shutdown_secs, rcu_torture_cleanup); 4743 if (torture_init_error(firsterr)) 4744 goto unwind; 4745 firsterr = torture_onoff_init(onoff_holdoff * HZ, onoff_interval, 4746 rcutorture_sync); 4747 if (torture_init_error(firsterr)) 4748 goto unwind; 4749 firsterr = rcu_torture_stall_init(); 4750 if (torture_init_error(firsterr)) 4751 goto unwind; 4752 firsterr = rcu_torture_fwd_prog_init(); 4753 if (torture_init_error(firsterr)) 4754 goto unwind; 4755 firsterr = rcu_torture_barrier_init(); 4756 if (torture_init_error(firsterr)) 4757 goto unwind; 4758 firsterr = rcu_torture_read_exit_init(); 4759 if (torture_init_error(firsterr)) 4760 goto unwind; 4761 if (preempt_duration > 0) { 4762 firsterr = torture_create_kthread(rcu_torture_preempt, NULL, preempt_task); 4763 if (torture_init_error(firsterr)) 4764 goto unwind; 4765 } 4766 if (object_debug) 4767 rcu_test_debug_objects(); 4768 4769 if (cur_ops->gp_slow_register && !WARN_ON_ONCE(!cur_ops->gp_slow_unregister)) 4770 cur_ops->gp_slow_register(&rcu_fwd_cb_nodelay); 4771 4772 if (gpwrap_lag && cur_ops->set_gpwrap_lag) { 4773 firsterr = rcu_gpwrap_lag_init(); 4774 if (torture_init_error(firsterr)) 4775 goto unwind; 4776 } 4777 4778 torture_init_end(); 4779 return 0; 4780 4781 unwind: 4782 torture_init_end(); 4783 rcu_torture_cleanup(); 4784 if (shutdown_secs) { 4785 WARN_ON(!IS_MODULE(CONFIG_RCU_TORTURE_TEST)); 4786 kernel_power_off(); 4787 } 4788 return firsterr; 4789 } 4790 4791 module_init(rcu_torture_init); 4792 module_exit(rcu_torture_cleanup); 4793