1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 2003-2008 Joseph Koshy 5 * Copyright (c) 2007 The FreeBSD Foundation 6 * Copyright (c) 2018 Matthew Macy 7 * All rights reserved. 8 * 9 * Portions of this software were developed by A. Joseph Koshy under 10 * sponsorship from the FreeBSD Foundation and Google, Inc. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 #include <sys/param.h> 35 #include <sys/systm.h> 36 #include <sys/domainset.h> 37 #include <sys/eventhandler.h> 38 #include <sys/jail.h> 39 #include <sys/kernel.h> 40 #include <sys/kthread.h> 41 #include <sys/limits.h> 42 #include <sys/lock.h> 43 #include <sys/malloc.h> 44 #include <sys/module.h> 45 #include <sys/mount.h> 46 #include <sys/mutex.h> 47 #include <sys/pmc.h> 48 #include <sys/pmckern.h> 49 #include <sys/pmclog.h> 50 #include <sys/priv.h> 51 #include <sys/proc.h> 52 #include <sys/queue.h> 53 #include <sys/resourcevar.h> 54 #include <sys/rwlock.h> 55 #include <sys/sched.h> 56 #include <sys/signalvar.h> 57 #include <sys/smp.h> 58 #include <sys/sx.h> 59 #include <sys/sysctl.h> 60 #include <sys/sysent.h> 61 #include <sys/syslog.h> 62 #include <sys/taskqueue.h> 63 #include <sys/vnode.h> 64 65 #include <sys/linker.h> /* needs to be after <sys/malloc.h> */ 66 67 #include <machine/atomic.h> 68 #include <machine/md_var.h> 69 70 #include <vm/vm.h> 71 #include <vm/vm_extern.h> 72 #include <vm/pmap.h> 73 #include <vm/vm_map.h> 74 #include <vm/vm_object.h> 75 76 #include "hwpmc_soft.h" 77 78 #define PMC_EPOCH_ENTER() \ 79 struct epoch_tracker pmc_et; \ 80 epoch_enter_preempt(global_epoch_preempt, &pmc_et) 81 82 #define PMC_EPOCH_EXIT() \ 83 epoch_exit_preempt(global_epoch_preempt, &pmc_et) 84 85 /* 86 * Types 87 */ 88 89 enum pmc_flags { 90 PMC_FLAG_NONE = 0x00, /* do nothing */ 91 PMC_FLAG_REMOVE = 0x01, /* atomically remove entry from hash */ 92 PMC_FLAG_ALLOCATE = 0x02, /* add entry to hash if not found */ 93 PMC_FLAG_NOWAIT = 0x04, /* do not wait for mallocs */ 94 }; 95 96 /* 97 * The offset in sysent where the syscall is allocated. 98 */ 99 static int pmc_syscall_num = NO_SYSCALL; 100 101 struct pmc_cpu **pmc_pcpu; /* per-cpu state */ 102 pmc_value_t *pmc_pcpu_saved; /* saved PMC values: CSW handling */ 103 104 #define PMC_PCPU_SAVED(C, R) pmc_pcpu_saved[(R) + md->pmd_npmc * (C)] 105 106 struct mtx_pool *pmc_mtxpool; 107 static int *pmc_pmcdisp; /* PMC row dispositions */ 108 109 #define PMC_ROW_DISP_IS_FREE(R) (pmc_pmcdisp[(R)] == 0) 110 #define PMC_ROW_DISP_IS_THREAD(R) (pmc_pmcdisp[(R)] > 0) 111 #define PMC_ROW_DISP_IS_STANDALONE(R) (pmc_pmcdisp[(R)] < 0) 112 113 #define PMC_MARK_ROW_FREE(R) do { \ 114 pmc_pmcdisp[(R)] = 0; \ 115 } while (0) 116 117 #define PMC_MARK_ROW_STANDALONE(R) do { \ 118 KASSERT(pmc_pmcdisp[(R)] <= 0, ("[pmc,%d] row disposition error", \ 119 __LINE__)); \ 120 atomic_add_int(&pmc_pmcdisp[(R)], -1); \ 121 KASSERT(pmc_pmcdisp[(R)] >= (-pmc_cpu_max_active()), \ 122 ("[pmc,%d] row disposition error", __LINE__)); \ 123 } while (0) 124 125 #define PMC_UNMARK_ROW_STANDALONE(R) do { \ 126 atomic_add_int(&pmc_pmcdisp[(R)], 1); \ 127 KASSERT(pmc_pmcdisp[(R)] <= 0, ("[pmc,%d] row disposition error", \ 128 __LINE__)); \ 129 } while (0) 130 131 #define PMC_MARK_ROW_THREAD(R) do { \ 132 KASSERT(pmc_pmcdisp[(R)] >= 0, ("[pmc,%d] row disposition error", \ 133 __LINE__)); \ 134 atomic_add_int(&pmc_pmcdisp[(R)], 1); \ 135 } while (0) 136 137 #define PMC_UNMARK_ROW_THREAD(R) do { \ 138 atomic_add_int(&pmc_pmcdisp[(R)], -1); \ 139 KASSERT(pmc_pmcdisp[(R)] >= 0, ("[pmc,%d] row disposition error", \ 140 __LINE__)); \ 141 } while (0) 142 143 /* various event handlers */ 144 static eventhandler_tag pmc_exit_tag, pmc_fork_tag, pmc_kld_load_tag, 145 pmc_kld_unload_tag; 146 147 /* Module statistics */ 148 struct pmc_driverstats pmc_stats; 149 150 /* Machine/processor dependent operations */ 151 static struct pmc_mdep *md; 152 153 /* 154 * Hash tables mapping owner processes and target threads to PMCs. 155 */ 156 struct mtx pmc_processhash_mtx; /* spin mutex */ 157 static u_long pmc_processhashmask; 158 static LIST_HEAD(pmc_processhash, pmc_process) *pmc_processhash; 159 160 /* 161 * Hash table of PMC owner descriptors. This table is protected by 162 * the shared PMC "sx" lock. 163 */ 164 static u_long pmc_ownerhashmask; 165 static LIST_HEAD(pmc_ownerhash, pmc_owner) *pmc_ownerhash; 166 167 /* 168 * List of PMC owners with system-wide sampling PMCs. 169 */ 170 static CK_LIST_HEAD(, pmc_owner) pmc_ss_owners; 171 172 /* 173 * List of free thread entries. This is protected by the spin 174 * mutex. 175 */ 176 static struct mtx pmc_threadfreelist_mtx; /* spin mutex */ 177 static LIST_HEAD(, pmc_thread) pmc_threadfreelist; 178 static int pmc_threadfreelist_entries = 0; 179 #define THREADENTRY_SIZE (sizeof(struct pmc_thread) + \ 180 (md->pmd_npmc * sizeof(struct pmc_threadpmcstate))) 181 182 /* 183 * Task to free thread descriptors 184 */ 185 static struct task free_task; 186 187 /* 188 * A map of row indices to classdep structures. 189 */ 190 static struct pmc_classdep **pmc_rowindex_to_classdep; 191 192 /* 193 * Prototypes 194 */ 195 196 #ifdef HWPMC_DEBUG 197 static int pmc_debugflags_sysctl_handler(SYSCTL_HANDLER_ARGS); 198 static int pmc_debugflags_parse(char *newstr, char *fence); 199 #endif 200 201 static int load(struct module *module, int cmd, void *arg); 202 static int pmc_add_sample(ring_type_t ring, struct pmc *pm, 203 struct trapframe *tf); 204 static void pmc_add_thread_descriptors_from_proc(struct proc *p, 205 struct pmc_process *pp); 206 static int pmc_attach_process(struct proc *p, struct pmc *pm); 207 static struct pmc *pmc_allocate_pmc_descriptor(void); 208 static struct pmc_owner *pmc_allocate_owner_descriptor(struct proc *p); 209 static int pmc_attach_one_process(struct proc *p, struct pmc *pm); 210 static bool pmc_can_allocate_row(int ri, enum pmc_mode mode); 211 static bool pmc_can_allocate_rowindex(struct proc *p, unsigned int ri, 212 int cpu); 213 static int pmc_can_attach(struct pmc *pm, struct proc *p); 214 static void pmc_capture_user_callchain(int cpu, int soft, 215 struct trapframe *tf); 216 static void pmc_cleanup(void); 217 static int pmc_detach_process(struct proc *p, struct pmc *pm); 218 static int pmc_detach_one_process(struct proc *p, struct pmc *pm, 219 int flags); 220 static void pmc_destroy_owner_descriptor(struct pmc_owner *po); 221 static void pmc_destroy_pmc_descriptor(struct pmc *pm); 222 static void pmc_destroy_process_descriptor(struct pmc_process *pp); 223 static struct pmc_owner *pmc_find_owner_descriptor(struct proc *p); 224 static int pmc_find_pmc(pmc_id_t pmcid, struct pmc **pm); 225 static struct pmc *pmc_find_pmc_descriptor_in_process(struct pmc_owner *po, 226 pmc_id_t pmc); 227 static struct pmc_process *pmc_find_process_descriptor(struct proc *p, 228 uint32_t mode); 229 static struct pmc_thread *pmc_find_thread_descriptor(struct pmc_process *pp, 230 struct thread *td, uint32_t mode); 231 static void pmc_force_context_switch(void); 232 static void pmc_link_target_process(struct pmc *pm, 233 struct pmc_process *pp); 234 static void pmc_log_all_process_mappings(struct pmc_owner *po); 235 static void pmc_log_kernel_mappings(struct pmc *pm); 236 static void pmc_log_process_mappings(struct pmc_owner *po, struct proc *p); 237 static void pmc_maybe_remove_owner(struct pmc_owner *po); 238 static void pmc_post_callchain_callback(void); 239 static void pmc_process_allproc(struct pmc *pm); 240 static void pmc_process_csw_in(struct thread *td); 241 static void pmc_process_csw_out(struct thread *td); 242 static void pmc_process_exec(struct thread *td, 243 struct pmckern_procexec *pk); 244 static void pmc_process_exit(void *arg, struct proc *p); 245 static void pmc_process_fork(void *arg, struct proc *p1, 246 struct proc *p2, int n); 247 static void pmc_process_proccreate(struct proc *p); 248 static void pmc_process_samples(int cpu, ring_type_t soft); 249 static void pmc_process_threadcreate(struct thread *td); 250 static void pmc_process_threadexit(struct thread *td); 251 static void pmc_process_thread_add(struct thread *td); 252 static void pmc_process_thread_delete(struct thread *td); 253 static void pmc_process_thread_userret(struct thread *td); 254 static void pmc_release_pmc_descriptor(struct pmc *pmc); 255 static void pmc_remove_owner(struct pmc_owner *po); 256 static void pmc_remove_process_descriptor(struct pmc_process *pp); 257 static int pmc_start(struct pmc *pm); 258 static int pmc_stop(struct pmc *pm); 259 static int pmc_syscall_handler(struct thread *td, void *syscall_args); 260 static struct pmc_thread *pmc_thread_descriptor_pool_alloc(void); 261 static void pmc_thread_descriptor_pool_drain(void); 262 static void pmc_thread_descriptor_pool_free(struct pmc_thread *pt); 263 static void pmc_unlink_target_process(struct pmc *pmc, 264 struct pmc_process *pp); 265 266 static int generic_switch_in(struct pmc_cpu *pc, struct pmc_process *pp); 267 static int generic_switch_out(struct pmc_cpu *pc, struct pmc_process *pp); 268 static struct pmc_mdep *pmc_generic_cpu_initialize(void); 269 static void pmc_generic_cpu_finalize(struct pmc_mdep *md); 270 271 /* 272 * Kernel tunables and sysctl(8) interface. 273 */ 274 275 SYSCTL_DECL(_kern_hwpmc); 276 SYSCTL_NODE(_kern_hwpmc, OID_AUTO, stats, CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 277 "HWPMC stats"); 278 279 /* Stats. */ 280 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, intr_ignored, CTLFLAG_RW, 281 &pmc_stats.pm_intr_ignored, 282 "# of interrupts ignored"); 283 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, intr_processed, CTLFLAG_RW, 284 &pmc_stats.pm_intr_processed, 285 "# of interrupts processed"); 286 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, intr_bufferfull, CTLFLAG_RW, 287 &pmc_stats.pm_intr_bufferfull, 288 "# of interrupts where buffer was full"); 289 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, syscalls, CTLFLAG_RW, 290 &pmc_stats.pm_syscalls, 291 "# of syscalls"); 292 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, syscall_errors, CTLFLAG_RW, 293 &pmc_stats.pm_syscall_errors, 294 "# of syscall_errors"); 295 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, buffer_requests, CTLFLAG_RW, 296 &pmc_stats.pm_buffer_requests, 297 "# of buffer requests"); 298 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, buffer_requests_failed, 299 CTLFLAG_RW, &pmc_stats.pm_buffer_requests_failed, 300 "# of buffer requests which failed"); 301 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, log_sweeps, CTLFLAG_RW, 302 &pmc_stats.pm_log_sweeps, 303 "# of times samples were processed"); 304 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, merges, CTLFLAG_RW, 305 &pmc_stats.pm_merges, 306 "# of times kernel stack was found for user trace"); 307 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, overwrites, CTLFLAG_RW, 308 &pmc_stats.pm_overwrites, 309 "# of times a sample was overwritten before being logged"); 310 311 static int pmc_callchaindepth = PMC_CALLCHAIN_DEPTH; 312 SYSCTL_INT(_kern_hwpmc, OID_AUTO, callchaindepth, CTLFLAG_RDTUN, 313 &pmc_callchaindepth, 0, 314 "depth of call chain records"); 315 316 char pmc_cpuid[PMC_CPUID_LEN]; 317 SYSCTL_STRING(_kern_hwpmc, OID_AUTO, cpuid, CTLFLAG_RD, 318 pmc_cpuid, 0, 319 "cpu version string"); 320 321 #ifdef HWPMC_DEBUG 322 struct pmc_debugflags pmc_debugflags = PMC_DEBUG_DEFAULT_FLAGS; 323 char pmc_debugstr[PMC_DEBUG_STRSIZE]; 324 TUNABLE_STR(PMC_SYSCTL_NAME_PREFIX "debugflags", pmc_debugstr, 325 sizeof(pmc_debugstr)); 326 SYSCTL_PROC(_kern_hwpmc, OID_AUTO, debugflags, 327 CTLTYPE_STRING | CTLFLAG_RWTUN | CTLFLAG_NOFETCH | CTLFLAG_MPSAFE, 328 0, 0, pmc_debugflags_sysctl_handler, "A", 329 "debug flags"); 330 #endif 331 332 /* 333 * kern.hwpmc.hashsize -- determines the number of rows in the 334 * of the hash table used to look up threads 335 */ 336 static int pmc_hashsize = PMC_HASH_SIZE; 337 SYSCTL_INT(_kern_hwpmc, OID_AUTO, hashsize, CTLFLAG_RDTUN, 338 &pmc_hashsize, 0, 339 "rows in hash tables"); 340 341 /* 342 * kern.hwpmc.nsamples --- number of PC samples/callchain stacks per CPU 343 */ 344 static int pmc_nsamples = PMC_NSAMPLES; 345 SYSCTL_INT(_kern_hwpmc, OID_AUTO, nsamples, CTLFLAG_RDTUN, 346 &pmc_nsamples, 0, 347 "number of PC samples per CPU"); 348 349 static uint64_t pmc_sample_mask = PMC_NSAMPLES - 1; 350 351 /* 352 * kern.hwpmc.mtxpoolsize -- number of mutexes in the mutex pool. 353 */ 354 static int pmc_mtxpool_size = PMC_MTXPOOL_SIZE; 355 SYSCTL_INT(_kern_hwpmc, OID_AUTO, mtxpoolsize, CTLFLAG_RDTUN, 356 &pmc_mtxpool_size, 0, 357 "size of spin mutex pool"); 358 359 /* 360 * kern.hwpmc.threadfreelist_entries -- number of free entries 361 */ 362 SYSCTL_INT(_kern_hwpmc, OID_AUTO, threadfreelist_entries, CTLFLAG_RD, 363 &pmc_threadfreelist_entries, 0, 364 "number of available thread entries"); 365 366 /* 367 * kern.hwpmc.threadfreelist_max -- maximum number of free entries 368 */ 369 static int pmc_threadfreelist_max = PMC_THREADLIST_MAX; 370 SYSCTL_INT(_kern_hwpmc, OID_AUTO, threadfreelist_max, CTLFLAG_RW, 371 &pmc_threadfreelist_max, 0, 372 "maximum number of available thread entries before freeing some"); 373 374 /* 375 * kern.hwpmc.mincount -- minimum sample count 376 */ 377 static u_int pmc_mincount = 1000; 378 SYSCTL_INT(_kern_hwpmc, OID_AUTO, mincount, CTLFLAG_RWTUN, 379 &pmc_mincount, 0, 380 "minimum count for sampling counters"); 381 382 /* 383 * security.bsd.unprivileged_syspmcs -- allow non-root processes to 384 * allocate system-wide PMCs. 385 * 386 * Allowing unprivileged processes to allocate system PMCs is convenient 387 * if system-wide measurements need to be taken concurrently with other 388 * per-process measurements. This feature is turned off by default. 389 */ 390 static int pmc_unprivileged_syspmcs = 0; 391 SYSCTL_INT(_security_bsd, OID_AUTO, unprivileged_syspmcs, CTLFLAG_RWTUN, 392 &pmc_unprivileged_syspmcs, 0, 393 "allow unprivileged process to allocate system PMCs"); 394 395 /* 396 * Hash function. Discard the lower 2 bits of the pointer since 397 * these are always zero for our uses. The hash multiplier is 398 * round((2^LONG_BIT) * ((sqrt(5)-1)/2)). 399 */ 400 #if LONG_BIT == 64 401 #define _PMC_HM 11400714819323198486u 402 #elif LONG_BIT == 32 403 #define _PMC_HM 2654435769u 404 #else 405 #error Must know the size of 'long' to compile 406 #endif 407 408 #define PMC_HASH_PTR(P,M) ((((unsigned long) (P) >> 2) * _PMC_HM) & (M)) 409 410 /* 411 * Syscall structures 412 */ 413 414 /* The `sysent' for the new syscall */ 415 static struct sysent pmc_sysent = { 416 .sy_narg = 2, 417 .sy_call = pmc_syscall_handler, 418 }; 419 420 static struct syscall_module_data pmc_syscall_mod = { 421 .chainevh = load, 422 .chainarg = NULL, 423 .offset = &pmc_syscall_num, 424 .new_sysent = &pmc_sysent, 425 .old_sysent = { .sy_narg = 0, .sy_call = NULL }, 426 .flags = SY_THR_STATIC_KLD, 427 }; 428 429 static moduledata_t pmc_mod = { 430 .name = PMC_MODULE_NAME, 431 .evhand = syscall_module_handler, 432 .priv = &pmc_syscall_mod, 433 }; 434 435 #ifdef EARLY_AP_STARTUP 436 DECLARE_MODULE(pmc, pmc_mod, SI_SUB_SYSCALLS, SI_ORDER_ANY); 437 #else 438 DECLARE_MODULE(pmc, pmc_mod, SI_SUB_SMP, SI_ORDER_ANY); 439 #endif 440 MODULE_VERSION(pmc, PMC_VERSION); 441 442 #ifdef HWPMC_DEBUG 443 enum pmc_dbgparse_state { 444 PMCDS_WS, /* in whitespace */ 445 PMCDS_MAJOR, /* seen a major keyword */ 446 PMCDS_MINOR 447 }; 448 449 static int 450 pmc_debugflags_parse(char *newstr, char *fence) 451 { 452 struct pmc_debugflags *tmpflags; 453 size_t kwlen; 454 char c, *p, *q; 455 int error, *newbits, tmp; 456 int found; 457 458 tmpflags = malloc(sizeof(*tmpflags), M_PMC, M_WAITOK | M_ZERO); 459 460 error = 0; 461 for (p = newstr; p < fence && (c = *p); p++) { 462 /* skip white space */ 463 if (c == ' ' || c == '\t') 464 continue; 465 466 /* look for a keyword followed by "=" */ 467 for (q = p; p < fence && (c = *p) && c != '='; p++) 468 ; 469 if (c != '=') { 470 error = EINVAL; 471 goto done; 472 } 473 474 kwlen = p - q; 475 newbits = NULL; 476 477 /* lookup flag group name */ 478 #define DBG_SET_FLAG_MAJ(S,F) \ 479 if (kwlen == sizeof(S)-1 && strncmp(q, S, kwlen) == 0) \ 480 newbits = &tmpflags->pdb_ ## F; 481 482 DBG_SET_FLAG_MAJ("cpu", CPU); 483 DBG_SET_FLAG_MAJ("csw", CSW); 484 DBG_SET_FLAG_MAJ("logging", LOG); 485 DBG_SET_FLAG_MAJ("module", MOD); 486 DBG_SET_FLAG_MAJ("md", MDP); 487 DBG_SET_FLAG_MAJ("owner", OWN); 488 DBG_SET_FLAG_MAJ("pmc", PMC); 489 DBG_SET_FLAG_MAJ("process", PRC); 490 DBG_SET_FLAG_MAJ("sampling", SAM); 491 #undef DBG_SET_FLAG_MAJ 492 493 if (newbits == NULL) { 494 error = EINVAL; 495 goto done; 496 } 497 498 p++; /* skip the '=' */ 499 500 /* Now parse the individual flags */ 501 tmp = 0; 502 newflag: 503 for (q = p; p < fence && (c = *p); p++) 504 if (c == ' ' || c == '\t' || c == ',') 505 break; 506 507 /* p == fence or c == ws or c == "," or c == 0 */ 508 509 if ((kwlen = p - q) == 0) { 510 *newbits = tmp; 511 continue; 512 } 513 514 found = 0; 515 #define DBG_SET_FLAG_MIN(S,F) \ 516 if (kwlen == sizeof(S)-1 && strncmp(q, S, kwlen) == 0) \ 517 tmp |= found = (1 << PMC_DEBUG_MIN_ ## F) 518 519 /* a '*' denotes all possible flags in the group */ 520 if (kwlen == 1 && *q == '*') 521 tmp = found = ~0; 522 /* look for individual flag names */ 523 DBG_SET_FLAG_MIN("allocaterow", ALR); 524 DBG_SET_FLAG_MIN("allocate", ALL); 525 DBG_SET_FLAG_MIN("attach", ATT); 526 DBG_SET_FLAG_MIN("bind", BND); 527 DBG_SET_FLAG_MIN("config", CFG); 528 DBG_SET_FLAG_MIN("exec", EXC); 529 DBG_SET_FLAG_MIN("exit", EXT); 530 DBG_SET_FLAG_MIN("find", FND); 531 DBG_SET_FLAG_MIN("flush", FLS); 532 DBG_SET_FLAG_MIN("fork", FRK); 533 DBG_SET_FLAG_MIN("getbuf", GTB); 534 DBG_SET_FLAG_MIN("hook", PMH); 535 DBG_SET_FLAG_MIN("init", INI); 536 DBG_SET_FLAG_MIN("intr", INT); 537 DBG_SET_FLAG_MIN("linktarget", TLK); 538 DBG_SET_FLAG_MIN("mayberemove", OMR); 539 DBG_SET_FLAG_MIN("ops", OPS); 540 DBG_SET_FLAG_MIN("read", REA); 541 DBG_SET_FLAG_MIN("register", REG); 542 DBG_SET_FLAG_MIN("release", REL); 543 DBG_SET_FLAG_MIN("remove", ORM); 544 DBG_SET_FLAG_MIN("sample", SAM); 545 DBG_SET_FLAG_MIN("scheduleio", SIO); 546 DBG_SET_FLAG_MIN("select", SEL); 547 DBG_SET_FLAG_MIN("signal", SIG); 548 DBG_SET_FLAG_MIN("swi", SWI); 549 DBG_SET_FLAG_MIN("swo", SWO); 550 DBG_SET_FLAG_MIN("start", STA); 551 DBG_SET_FLAG_MIN("stop", STO); 552 DBG_SET_FLAG_MIN("syscall", PMS); 553 DBG_SET_FLAG_MIN("unlinktarget", TUL); 554 DBG_SET_FLAG_MIN("write", WRI); 555 #undef DBG_SET_FLAG_MIN 556 if (found == 0) { 557 /* unrecognized flag name */ 558 error = EINVAL; 559 goto done; 560 } 561 562 if (c == 0 || c == ' ' || c == '\t') { /* end of flag group */ 563 *newbits = tmp; 564 continue; 565 } 566 567 p++; 568 goto newflag; 569 } 570 571 /* save the new flag set */ 572 bcopy(tmpflags, &pmc_debugflags, sizeof(pmc_debugflags)); 573 done: 574 free(tmpflags, M_PMC); 575 return (error); 576 } 577 578 static int 579 pmc_debugflags_sysctl_handler(SYSCTL_HANDLER_ARGS) 580 { 581 char *fence, *newstr; 582 int error; 583 u_int n; 584 585 n = sizeof(pmc_debugstr); 586 newstr = malloc(n, M_PMC, M_WAITOK | M_ZERO); 587 strlcpy(newstr, pmc_debugstr, n); 588 589 error = sysctl_handle_string(oidp, newstr, n, req); 590 591 /* if there is a new string, parse and copy it */ 592 if (error == 0 && req->newptr != NULL) { 593 fence = newstr + (n < req->newlen ? n : req->newlen + 1); 594 error = pmc_debugflags_parse(newstr, fence); 595 if (error == 0) 596 strlcpy(pmc_debugstr, newstr, sizeof(pmc_debugstr)); 597 } 598 free(newstr, M_PMC); 599 600 return (error); 601 } 602 #endif 603 604 /* 605 * Map a row index to a classdep structure and return the adjusted row 606 * index for the PMC class index. 607 */ 608 static struct pmc_classdep * 609 pmc_ri_to_classdep(struct pmc_mdep *md __unused, int ri, int *adjri) 610 { 611 struct pmc_classdep *pcd; 612 613 KASSERT(ri >= 0 && ri < md->pmd_npmc, 614 ("[pmc,%d] illegal row-index %d", __LINE__, ri)); 615 616 pcd = pmc_rowindex_to_classdep[ri]; 617 KASSERT(pcd != NULL, 618 ("[pmc,%d] ri %d null pcd", __LINE__, ri)); 619 620 *adjri = ri - pcd->pcd_ri; 621 KASSERT(*adjri >= 0 && *adjri < pcd->pcd_num, 622 ("[pmc,%d] adjusted row-index %d", __LINE__, *adjri)); 623 624 return (pcd); 625 } 626 627 /* 628 * Concurrency Control 629 * 630 * The driver manages the following data structures: 631 * 632 * - target process descriptors, one per target process 633 * - owner process descriptors (and attached lists), one per owner process 634 * - lookup hash tables for owner and target processes 635 * - PMC descriptors (and attached lists) 636 * - per-cpu hardware state 637 * - the 'hook' variable through which the kernel calls into 638 * this module 639 * - the machine hardware state (managed by the MD layer) 640 * 641 * These data structures are accessed from: 642 * 643 * - thread context-switch code 644 * - interrupt handlers (possibly on multiple cpus) 645 * - kernel threads on multiple cpus running on behalf of user 646 * processes doing system calls 647 * - this driver's private kernel threads 648 * 649 * = Locks and Locking strategy = 650 * 651 * The driver uses four locking strategies for its operation: 652 * 653 * - The global SX lock "pmc_sx" is used to protect internal 654 * data structures. 655 * 656 * Calls into the module by syscall() start with this lock being 657 * held in exclusive mode. Depending on the requested operation, 658 * the lock may be downgraded to 'shared' mode to allow more 659 * concurrent readers into the module. Calls into the module from 660 * other parts of the kernel acquire the lock in shared mode. 661 * 662 * This SX lock is held in exclusive mode for any operations that 663 * modify the linkages between the driver's internal data structures. 664 * 665 * The 'pmc_hook' function pointer is also protected by this lock. 666 * It is only examined with the sx lock held in exclusive mode. The 667 * kernel module is allowed to be unloaded only with the sx lock held 668 * in exclusive mode. In normal syscall handling, after acquiring the 669 * pmc_sx lock we first check that 'pmc_hook' is non-null before 670 * proceeding. This prevents races between the thread unloading the module 671 * and other threads seeking to use the module. 672 * 673 * - Lookups of target process structures and owner process structures 674 * cannot use the global "pmc_sx" SX lock because these lookups need 675 * to happen during context switches and in other critical sections 676 * where sleeping is not allowed. We protect these lookup tables 677 * with their own private spin-mutexes, "pmc_processhash_mtx" and 678 * "pmc_ownerhash_mtx". 679 * 680 * - Interrupt handlers work in a lock free manner. At interrupt 681 * time, handlers look at the PMC pointer (phw->phw_pmc) configured 682 * when the PMC was started. If this pointer is NULL, the interrupt 683 * is ignored after updating driver statistics. We ensure that this 684 * pointer is set (using an atomic operation if necessary) before the 685 * PMC hardware is started. Conversely, this pointer is unset atomically 686 * only after the PMC hardware is stopped. 687 * 688 * We ensure that everything needed for the operation of an 689 * interrupt handler is available without it needing to acquire any 690 * locks. We also ensure that a PMC's software state is destroyed only 691 * after the PMC is taken off hardware (on all CPUs). 692 * 693 * - Context-switch handling with process-private PMCs needs more 694 * care. 695 * 696 * A given process may be the target of multiple PMCs. For example, 697 * PMCATTACH and PMCDETACH may be requested by a process on one CPU 698 * while the target process is running on another. A PMC could also 699 * be getting released because its owner is exiting. We tackle 700 * these situations in the following manner: 701 * 702 * - each target process structure 'pmc_process' has an array 703 * of 'struct pmc *' pointers, one for each hardware PMC. 704 * 705 * - At context switch IN time, each "target" PMC in RUNNING state 706 * gets started on hardware and a pointer to each PMC is copied into 707 * the per-cpu phw array. The 'runcount' for the PMC is 708 * incremented. 709 * 710 * - At context switch OUT time, all process-virtual PMCs are stopped 711 * on hardware. The saved value is added to the PMCs value field 712 * only if the PMC is in a non-deleted state (the PMCs state could 713 * have changed during the current time slice). 714 * 715 * Note that since in-between a switch IN on a processor and a switch 716 * OUT, the PMC could have been released on another CPU. Therefore 717 * context switch OUT always looks at the hardware state to turn 718 * OFF PMCs and will update a PMC's saved value only if reachable 719 * from the target process record. 720 * 721 * - OP PMCRELEASE could be called on a PMC at any time (the PMC could 722 * be attached to many processes at the time of the call and could 723 * be active on multiple CPUs). 724 * 725 * We prevent further scheduling of the PMC by marking it as in 726 * state 'DELETED'. If the runcount of the PMC is non-zero then 727 * this PMC is currently running on a CPU somewhere. The thread 728 * doing the PMCRELEASE operation waits by repeatedly doing a 729 * pause() till the runcount comes to zero. 730 * 731 * The contents of a PMC descriptor (struct pmc) are protected using 732 * a spin-mutex. In order to save space, we use a mutex pool. 733 * 734 * In terms of lock types used by witness(4), we use: 735 * - Type "pmc-sx", used by the global SX lock. 736 * - Type "pmc-sleep", for sleep mutexes used by logger threads. 737 * - Type "pmc-per-proc", for protecting PMC owner descriptors. 738 * - Type "pmc-leaf", used for all other spin mutexes. 739 */ 740 741 /* 742 * Save the CPU binding of the current kthread. 743 */ 744 void 745 pmc_save_cpu_binding(struct pmc_binding *pb) 746 { 747 PMCDBG0(CPU,BND,2, "save-cpu"); 748 thread_lock(curthread); 749 pb->pb_bound = sched_is_bound(curthread); 750 pb->pb_cpu = curthread->td_oncpu; 751 pb->pb_priority = curthread->td_priority; 752 thread_unlock(curthread); 753 PMCDBG1(CPU,BND,2, "save-cpu cpu=%d", pb->pb_cpu); 754 } 755 756 /* 757 * Restore the CPU binding of the current thread. 758 */ 759 void 760 pmc_restore_cpu_binding(struct pmc_binding *pb) 761 { 762 PMCDBG2(CPU,BND,2, "restore-cpu curcpu=%d restore=%d", 763 curthread->td_oncpu, pb->pb_cpu); 764 thread_lock(curthread); 765 sched_bind(curthread, pb->pb_cpu); 766 if (!pb->pb_bound) 767 sched_unbind(curthread); 768 sched_prio(curthread, pb->pb_priority); 769 thread_unlock(curthread); 770 PMCDBG0(CPU,BND,2, "restore-cpu done"); 771 } 772 773 /* 774 * Move execution over to the specified CPU and bind it there. 775 */ 776 void 777 pmc_select_cpu(int cpu) 778 { 779 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 780 ("[pmc,%d] bad cpu number %d", __LINE__, cpu)); 781 782 /* Never move to an inactive CPU. */ 783 KASSERT(pmc_cpu_is_active(cpu), ("[pmc,%d] selecting inactive " 784 "CPU %d", __LINE__, cpu)); 785 786 PMCDBG1(CPU,SEL,2, "select-cpu cpu=%d", cpu); 787 thread_lock(curthread); 788 sched_prio(curthread, PRI_MIN); 789 sched_bind(curthread, cpu); 790 thread_unlock(curthread); 791 792 KASSERT(curthread->td_oncpu == cpu, 793 ("[pmc,%d] CPU not bound [cpu=%d, curr=%d]", __LINE__, 794 cpu, curthread->td_oncpu)); 795 796 PMCDBG1(CPU,SEL,2, "select-cpu cpu=%d ok", cpu); 797 } 798 799 /* 800 * Force a context switch. 801 * 802 * We do this by pause'ing for 1 tick -- invoking mi_switch() is not 803 * guaranteed to force a context switch. 804 */ 805 static void 806 pmc_force_context_switch(void) 807 { 808 809 pause("pmcctx", 1); 810 } 811 812 uint64_t 813 pmc_rdtsc(void) 814 { 815 #if defined(__i386__) || defined(__amd64__) 816 if (__predict_true(amd_feature & AMDID_RDTSCP)) 817 return (rdtscp()); 818 else 819 return (rdtsc()); 820 #else 821 return (get_cyclecount()); 822 #endif 823 } 824 825 /* 826 * Get the file name for an executable. This is a simple wrapper 827 * around vn_fullpath(9). 828 */ 829 static void 830 pmc_getfilename(struct vnode *v, char **fullpath, char **freepath) 831 { 832 833 *fullpath = "unknown"; 834 *freepath = NULL; 835 vn_fullpath(v, fullpath, freepath); 836 } 837 838 /* 839 * Remove a process owning PMCs. 840 */ 841 void 842 pmc_remove_owner(struct pmc_owner *po) 843 { 844 struct pmc *pm, *tmp; 845 846 sx_assert(&pmc_sx, SX_XLOCKED); 847 848 PMCDBG1(OWN,ORM,1, "remove-owner po=%p", po); 849 850 /* Remove descriptor from the owner hash table */ 851 LIST_REMOVE(po, po_next); 852 853 /* release all owned PMC descriptors */ 854 LIST_FOREACH_SAFE(pm, &po->po_pmcs, pm_next, tmp) { 855 PMCDBG1(OWN,ORM,2, "pmc=%p", pm); 856 KASSERT(pm->pm_owner == po, 857 ("[pmc,%d] owner %p != po %p", __LINE__, pm->pm_owner, po)); 858 859 pmc_release_pmc_descriptor(pm); /* will unlink from the list */ 860 pmc_destroy_pmc_descriptor(pm); 861 } 862 863 KASSERT(po->po_sscount == 0, 864 ("[pmc,%d] SS count not zero", __LINE__)); 865 KASSERT(LIST_EMPTY(&po->po_pmcs), 866 ("[pmc,%d] PMC list not empty", __LINE__)); 867 868 /* de-configure the log file if present */ 869 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 870 pmclog_deconfigure_log(po); 871 } 872 873 /* 874 * Remove an owner process record if all conditions are met. 875 */ 876 static void 877 pmc_maybe_remove_owner(struct pmc_owner *po) 878 { 879 880 PMCDBG1(OWN,OMR,1, "maybe-remove-owner po=%p", po); 881 882 /* 883 * Remove owner record if 884 * - this process does not own any PMCs 885 * - this process has not allocated a system-wide sampling buffer 886 */ 887 if (LIST_EMPTY(&po->po_pmcs) && 888 ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0)) { 889 pmc_remove_owner(po); 890 pmc_destroy_owner_descriptor(po); 891 } 892 } 893 894 /* 895 * Add an association between a target process and a PMC. 896 */ 897 static void 898 pmc_link_target_process(struct pmc *pm, struct pmc_process *pp) 899 { 900 struct pmc_target *pt; 901 struct pmc_thread *pt_td __diagused; 902 int ri; 903 904 sx_assert(&pmc_sx, SX_XLOCKED); 905 KASSERT(pm != NULL && pp != NULL, 906 ("[pmc,%d] Null pm %p or pp %p", __LINE__, pm, pp)); 907 KASSERT(PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)), 908 ("[pmc,%d] Attaching a non-process-virtual pmc=%p to pid=%d", 909 __LINE__, pm, pp->pp_proc->p_pid)); 910 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= ((int) md->pmd_npmc - 1), 911 ("[pmc,%d] Illegal reference count %d for process record %p", 912 __LINE__, pp->pp_refcnt, (void *) pp)); 913 914 ri = PMC_TO_ROWINDEX(pm); 915 916 PMCDBG3(PRC,TLK,1, "link-target pmc=%p ri=%d pmc-process=%p", 917 pm, ri, pp); 918 919 #ifdef HWPMC_DEBUG 920 LIST_FOREACH(pt, &pm->pm_targets, pt_next) { 921 if (pt->pt_process == pp) 922 KASSERT(0, ("[pmc,%d] pp %p already in pmc %p targets", 923 __LINE__, pp, pm)); 924 } 925 #endif 926 pt = malloc(sizeof(struct pmc_target), M_PMC, M_WAITOK | M_ZERO); 927 pt->pt_process = pp; 928 929 LIST_INSERT_HEAD(&pm->pm_targets, pt, pt_next); 930 931 atomic_store_rel_ptr((uintptr_t *)&pp->pp_pmcs[ri].pp_pmc, 932 (uintptr_t)pm); 933 934 if (pm->pm_owner->po_owner == pp->pp_proc) 935 pm->pm_flags |= PMC_F_ATTACHED_TO_OWNER; 936 937 /* 938 * Initialize the per-process values at this row index. 939 */ 940 pp->pp_pmcs[ri].pp_pmcval = PMC_TO_MODE(pm) == PMC_MODE_TS ? 941 pm->pm_sc.pm_reloadcount : 0; 942 pp->pp_refcnt++; 943 944 #ifdef INVARIANTS 945 /* Confirm that the per-thread values at this row index are cleared. */ 946 if (PMC_TO_MODE(pm) == PMC_MODE_TS) { 947 mtx_lock_spin(pp->pp_tdslock); 948 LIST_FOREACH(pt_td, &pp->pp_tds, pt_next) { 949 KASSERT(pt_td->pt_pmcs[ri].pt_pmcval == (pmc_value_t) 0, 950 ("[pmc,%d] pt_pmcval not cleared for pid=%d at " 951 "ri=%d", __LINE__, pp->pp_proc->p_pid, ri)); 952 } 953 mtx_unlock_spin(pp->pp_tdslock); 954 } 955 #endif 956 } 957 958 /* 959 * Removes the association between a target process and a PMC. 960 */ 961 static void 962 pmc_unlink_target_process(struct pmc *pm, struct pmc_process *pp) 963 { 964 int ri; 965 struct proc *p; 966 struct pmc_target *ptgt; 967 struct pmc_thread *pt; 968 969 sx_assert(&pmc_sx, SX_XLOCKED); 970 971 KASSERT(pm != NULL && pp != NULL, 972 ("[pmc,%d] Null pm %p or pp %p", __LINE__, pm, pp)); 973 974 KASSERT(pp->pp_refcnt >= 1 && pp->pp_refcnt <= (int) md->pmd_npmc, 975 ("[pmc,%d] Illegal ref count %d on process record %p", 976 __LINE__, pp->pp_refcnt, (void *) pp)); 977 978 ri = PMC_TO_ROWINDEX(pm); 979 980 PMCDBG3(PRC,TUL,1, "unlink-target pmc=%p ri=%d pmc-process=%p", 981 pm, ri, pp); 982 983 KASSERT(pp->pp_pmcs[ri].pp_pmc == pm, 984 ("[pmc,%d] PMC ri %d mismatch pmc %p pp->[ri] %p", __LINE__, 985 ri, pm, pp->pp_pmcs[ri].pp_pmc)); 986 987 pp->pp_pmcs[ri].pp_pmc = NULL; 988 pp->pp_pmcs[ri].pp_pmcval = (pmc_value_t)0; 989 990 /* Clear the per-thread values at this row index. */ 991 if (PMC_TO_MODE(pm) == PMC_MODE_TS) { 992 mtx_lock_spin(pp->pp_tdslock); 993 LIST_FOREACH(pt, &pp->pp_tds, pt_next) 994 pt->pt_pmcs[ri].pt_pmcval = (pmc_value_t)0; 995 mtx_unlock_spin(pp->pp_tdslock); 996 } 997 998 /* Remove owner-specific flags */ 999 if (pm->pm_owner->po_owner == pp->pp_proc) { 1000 pp->pp_flags &= ~PMC_PP_ENABLE_MSR_ACCESS; 1001 pm->pm_flags &= ~PMC_F_ATTACHED_TO_OWNER; 1002 } 1003 1004 pp->pp_refcnt--; 1005 1006 /* Remove the target process from the PMC structure */ 1007 LIST_FOREACH(ptgt, &pm->pm_targets, pt_next) 1008 if (ptgt->pt_process == pp) 1009 break; 1010 1011 KASSERT(ptgt != NULL, ("[pmc,%d] process %p (pp: %p) not found " 1012 "in pmc %p", __LINE__, pp->pp_proc, pp, pm)); 1013 1014 LIST_REMOVE(ptgt, pt_next); 1015 free(ptgt, M_PMC); 1016 1017 /* if the PMC now lacks targets, send the owner a SIGIO */ 1018 if (LIST_EMPTY(&pm->pm_targets)) { 1019 p = pm->pm_owner->po_owner; 1020 PROC_LOCK(p); 1021 kern_psignal(p, SIGIO); 1022 PROC_UNLOCK(p); 1023 1024 PMCDBG2(PRC,SIG,2, "signalling proc=%p signal=%d", p, SIGIO); 1025 } 1026 } 1027 1028 /* 1029 * Check if PMC 'pm' may be attached to target process 't'. 1030 */ 1031 1032 static int 1033 pmc_can_attach(struct pmc *pm, struct proc *t) 1034 { 1035 struct proc *o; /* pmc owner */ 1036 struct ucred *oc, *tc; /* owner, target credentials */ 1037 int decline_attach, i; 1038 1039 /* 1040 * A PMC's owner can always attach that PMC to itself. 1041 */ 1042 1043 if ((o = pm->pm_owner->po_owner) == t) 1044 return 0; 1045 1046 PROC_LOCK(o); 1047 oc = o->p_ucred; 1048 crhold(oc); 1049 PROC_UNLOCK(o); 1050 1051 PROC_LOCK(t); 1052 tc = t->p_ucred; 1053 crhold(tc); 1054 PROC_UNLOCK(t); 1055 1056 /* 1057 * The effective uid of the PMC owner should match at least one 1058 * of the {effective,real,saved} uids of the target process. 1059 */ 1060 1061 decline_attach = oc->cr_uid != tc->cr_uid && 1062 oc->cr_uid != tc->cr_svuid && 1063 oc->cr_uid != tc->cr_ruid; 1064 1065 /* 1066 * Every one of the target's group ids, must be in the owner's 1067 * group list. 1068 */ 1069 for (i = 0; !decline_attach && i < tc->cr_ngroups; i++) 1070 decline_attach = !groupmember(tc->cr_groups[i], oc); 1071 1072 /* check the read and saved gids too */ 1073 if (decline_attach == 0) 1074 decline_attach = !groupmember(tc->cr_rgid, oc) || 1075 !groupmember(tc->cr_svgid, oc); 1076 1077 crfree(tc); 1078 crfree(oc); 1079 1080 return !decline_attach; 1081 } 1082 1083 /* 1084 * Attach a process to a PMC. 1085 */ 1086 static int 1087 pmc_attach_one_process(struct proc *p, struct pmc *pm) 1088 { 1089 int ri, error; 1090 char *fullpath, *freepath; 1091 struct pmc_process *pp; 1092 1093 sx_assert(&pmc_sx, SX_XLOCKED); 1094 1095 PMCDBG5(PRC,ATT,2, "attach-one pm=%p ri=%d proc=%p (%d, %s)", pm, 1096 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 1097 1098 /* 1099 * Locate the process descriptor corresponding to process 'p', 1100 * allocating space as needed. 1101 * 1102 * Verify that rowindex 'pm_rowindex' is free in the process 1103 * descriptor. 1104 * 1105 * If not, allocate space for a descriptor and link the 1106 * process descriptor and PMC. 1107 */ 1108 ri = PMC_TO_ROWINDEX(pm); 1109 1110 /* mark process as using HWPMCs */ 1111 PROC_LOCK(p); 1112 p->p_flag |= P_HWPMC; 1113 PROC_UNLOCK(p); 1114 1115 if ((pp = pmc_find_process_descriptor(p, PMC_FLAG_ALLOCATE)) == NULL) { 1116 error = ENOMEM; 1117 goto fail; 1118 } 1119 1120 if (pp->pp_pmcs[ri].pp_pmc == pm) {/* already present at slot [ri] */ 1121 error = EEXIST; 1122 goto fail; 1123 } 1124 1125 if (pp->pp_pmcs[ri].pp_pmc != NULL) { 1126 error = EBUSY; 1127 goto fail; 1128 } 1129 1130 pmc_link_target_process(pm, pp); 1131 1132 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)) && 1133 (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) == 0) 1134 pm->pm_flags |= PMC_F_NEEDS_LOGFILE; 1135 1136 pm->pm_flags |= PMC_F_ATTACH_DONE; /* mark as attached */ 1137 1138 /* issue an attach event to a configured log file */ 1139 if (pm->pm_owner->po_flags & PMC_PO_OWNS_LOGFILE) { 1140 if (p->p_flag & P_KPROC) { 1141 fullpath = kernelname; 1142 freepath = NULL; 1143 } else { 1144 pmc_getfilename(p->p_textvp, &fullpath, &freepath); 1145 pmclog_process_pmcattach(pm, p->p_pid, fullpath); 1146 } 1147 free(freepath, M_TEMP); 1148 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 1149 pmc_log_process_mappings(pm->pm_owner, p); 1150 } 1151 1152 return (0); 1153 fail: 1154 PROC_LOCK(p); 1155 p->p_flag &= ~P_HWPMC; 1156 PROC_UNLOCK(p); 1157 return (error); 1158 } 1159 1160 /* 1161 * Attach a process and optionally its children 1162 */ 1163 static int 1164 pmc_attach_process(struct proc *p, struct pmc *pm) 1165 { 1166 int error; 1167 struct proc *top; 1168 1169 sx_assert(&pmc_sx, SX_XLOCKED); 1170 1171 PMCDBG5(PRC,ATT,1, "attach pm=%p ri=%d proc=%p (%d, %s)", pm, 1172 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 1173 1174 /* 1175 * If this PMC successfully allowed a GETMSR operation 1176 * in the past, disallow further ATTACHes. 1177 */ 1178 if ((pm->pm_flags & PMC_PP_ENABLE_MSR_ACCESS) != 0) 1179 return (EPERM); 1180 1181 if ((pm->pm_flags & PMC_F_DESCENDANTS) == 0) 1182 return (pmc_attach_one_process(p, pm)); 1183 1184 /* 1185 * Traverse all child processes, attaching them to 1186 * this PMC. 1187 */ 1188 sx_slock(&proctree_lock); 1189 1190 top = p; 1191 for (;;) { 1192 if ((error = pmc_attach_one_process(p, pm)) != 0) 1193 break; 1194 if (!LIST_EMPTY(&p->p_children)) 1195 p = LIST_FIRST(&p->p_children); 1196 else for (;;) { 1197 if (p == top) 1198 goto done; 1199 if (LIST_NEXT(p, p_sibling)) { 1200 p = LIST_NEXT(p, p_sibling); 1201 break; 1202 } 1203 p = p->p_pptr; 1204 } 1205 } 1206 1207 if (error != 0) 1208 (void)pmc_detach_process(top, pm); 1209 1210 done: 1211 sx_sunlock(&proctree_lock); 1212 return (error); 1213 } 1214 1215 /* 1216 * Detach a process from a PMC. If there are no other PMCs tracking 1217 * this process, remove the process structure from its hash table. If 1218 * 'flags' contains PMC_FLAG_REMOVE, then free the process structure. 1219 */ 1220 static int 1221 pmc_detach_one_process(struct proc *p, struct pmc *pm, int flags) 1222 { 1223 int ri; 1224 struct pmc_process *pp; 1225 1226 sx_assert(&pmc_sx, SX_XLOCKED); 1227 1228 KASSERT(pm != NULL, 1229 ("[pmc,%d] null pm pointer", __LINE__)); 1230 1231 ri = PMC_TO_ROWINDEX(pm); 1232 1233 PMCDBG6(PRC,ATT,2, "detach-one pm=%p ri=%d proc=%p (%d, %s) flags=0x%x", 1234 pm, ri, p, p->p_pid, p->p_comm, flags); 1235 1236 if ((pp = pmc_find_process_descriptor(p, 0)) == NULL) 1237 return (ESRCH); 1238 1239 if (pp->pp_pmcs[ri].pp_pmc != pm) 1240 return (EINVAL); 1241 1242 pmc_unlink_target_process(pm, pp); 1243 1244 /* Issue a detach entry if a log file is configured */ 1245 if (pm->pm_owner->po_flags & PMC_PO_OWNS_LOGFILE) 1246 pmclog_process_pmcdetach(pm, p->p_pid); 1247 1248 /* 1249 * If there are no PMCs targeting this process, we remove its 1250 * descriptor from the target hash table and unset the P_HWPMC 1251 * flag in the struct proc. 1252 */ 1253 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= (int) md->pmd_npmc, 1254 ("[pmc,%d] Illegal refcnt %d for process struct %p", 1255 __LINE__, pp->pp_refcnt, pp)); 1256 1257 if (pp->pp_refcnt != 0) /* still a target of some PMC */ 1258 return (0); 1259 1260 pmc_remove_process_descriptor(pp); 1261 1262 if (flags & PMC_FLAG_REMOVE) 1263 pmc_destroy_process_descriptor(pp); 1264 1265 PROC_LOCK(p); 1266 p->p_flag &= ~P_HWPMC; 1267 PROC_UNLOCK(p); 1268 1269 return (0); 1270 } 1271 1272 /* 1273 * Detach a process and optionally its descendants from a PMC. 1274 */ 1275 static int 1276 pmc_detach_process(struct proc *p, struct pmc *pm) 1277 { 1278 struct proc *top; 1279 1280 sx_assert(&pmc_sx, SX_XLOCKED); 1281 1282 PMCDBG5(PRC,ATT,1, "detach pm=%p ri=%d proc=%p (%d, %s)", pm, 1283 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 1284 1285 if ((pm->pm_flags & PMC_F_DESCENDANTS) == 0) 1286 return (pmc_detach_one_process(p, pm, PMC_FLAG_REMOVE)); 1287 1288 /* 1289 * Traverse all children, detaching them from this PMC. We 1290 * ignore errors since we could be detaching a PMC from a 1291 * partially attached proc tree. 1292 */ 1293 sx_slock(&proctree_lock); 1294 1295 top = p; 1296 for (;;) { 1297 (void)pmc_detach_one_process(p, pm, PMC_FLAG_REMOVE); 1298 1299 if (!LIST_EMPTY(&p->p_children)) { 1300 p = LIST_FIRST(&p->p_children); 1301 } else { 1302 for (;;) { 1303 if (p == top) 1304 goto done; 1305 if (LIST_NEXT(p, p_sibling)) { 1306 p = LIST_NEXT(p, p_sibling); 1307 break; 1308 } 1309 p = p->p_pptr; 1310 } 1311 } 1312 } 1313 done: 1314 sx_sunlock(&proctree_lock); 1315 if (LIST_EMPTY(&pm->pm_targets)) 1316 pm->pm_flags &= ~PMC_F_ATTACH_DONE; 1317 1318 return (0); 1319 } 1320 1321 /* 1322 * Handle events after an exec() for a process: 1323 * - Inform log owners of the new exec() event 1324 * - Release any PMCs owned by the process before the exec() 1325 * - Detach PMCs from the target if required 1326 */ 1327 static void 1328 pmc_process_exec(struct thread *td, struct pmckern_procexec *pk) 1329 { 1330 struct pmc *pm; 1331 struct pmc_owner *po; 1332 struct pmc_process *pp; 1333 struct proc *p; 1334 char *fullpath, *freepath; 1335 u_int ri; 1336 bool is_using_hwpmcs; 1337 1338 sx_assert(&pmc_sx, SX_XLOCKED); 1339 1340 p = td->td_proc; 1341 pmc_getfilename(p->p_textvp, &fullpath, &freepath); 1342 1343 PMC_EPOCH_ENTER(); 1344 /* Inform owners of SS mode PMCs of the exec event. */ 1345 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) { 1346 if ((po->po_flags & PMC_PO_OWNS_LOGFILE) != 0) { 1347 pmclog_process_procexec(po, PMC_ID_INVALID, p->p_pid, 1348 pk->pm_baseaddr, pk->pm_dynaddr, fullpath); 1349 } 1350 } 1351 PMC_EPOCH_EXIT(); 1352 1353 PROC_LOCK(p); 1354 is_using_hwpmcs = (p->p_flag & P_HWPMC) != 0; 1355 PROC_UNLOCK(p); 1356 1357 if (!is_using_hwpmcs) { 1358 if (freepath != NULL) 1359 free(freepath, M_TEMP); 1360 return; 1361 } 1362 1363 /* 1364 * PMCs are not inherited across an exec(): remove any PMCs that this 1365 * process is the owner of. 1366 */ 1367 if ((po = pmc_find_owner_descriptor(p)) != NULL) { 1368 pmc_remove_owner(po); 1369 pmc_destroy_owner_descriptor(po); 1370 } 1371 1372 /* 1373 * If the process being exec'ed is not the target of any PMC, we are 1374 * done. 1375 */ 1376 if ((pp = pmc_find_process_descriptor(p, 0)) == NULL) { 1377 if (freepath != NULL) 1378 free(freepath, M_TEMP); 1379 return; 1380 } 1381 1382 /* 1383 * Log the exec event to all monitoring owners. Skip owners who have 1384 * already received the event because they had system sampling PMCs 1385 * active. 1386 */ 1387 for (ri = 0; ri < md->pmd_npmc; ri++) { 1388 if ((pm = pp->pp_pmcs[ri].pp_pmc) == NULL) 1389 continue; 1390 1391 po = pm->pm_owner; 1392 if (po->po_sscount == 0 && 1393 (po->po_flags & PMC_PO_OWNS_LOGFILE) != 0) { 1394 pmclog_process_procexec(po, pm->pm_id, p->p_pid, 1395 pk->pm_baseaddr, pk->pm_dynaddr, fullpath); 1396 } 1397 } 1398 1399 if (freepath != NULL) 1400 free(freepath, M_TEMP); 1401 1402 PMCDBG4(PRC,EXC,1, "exec proc=%p (%d, %s) cred-changed=%d", 1403 p, p->p_pid, p->p_comm, pk->pm_credentialschanged); 1404 1405 if (pk->pm_credentialschanged == 0) /* no change */ 1406 return; 1407 1408 /* 1409 * If the newly exec()'ed process has a different credential 1410 * than before, allow it to be the target of a PMC only if 1411 * the PMC's owner has sufficient privilege. 1412 */ 1413 for (ri = 0; ri < md->pmd_npmc; ri++) { 1414 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) { 1415 if (pmc_can_attach(pm, td->td_proc) != 0) { 1416 pmc_detach_one_process(td->td_proc, pm, 1417 PMC_FLAG_NONE); 1418 } 1419 } 1420 } 1421 1422 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= md->pmd_npmc, 1423 ("[pmc,%d] Illegal ref count %u on pp %p", __LINE__, 1424 pp->pp_refcnt, pp)); 1425 1426 /* 1427 * If this process is no longer the target of any 1428 * PMCs, we can remove the process entry and free 1429 * up space. 1430 */ 1431 if (pp->pp_refcnt == 0) { 1432 pmc_remove_process_descriptor(pp); 1433 pmc_destroy_process_descriptor(pp); 1434 } 1435 } 1436 1437 /* 1438 * Thread context switch IN. 1439 */ 1440 static void 1441 pmc_process_csw_in(struct thread *td) 1442 { 1443 struct pmc *pm; 1444 struct pmc_classdep *pcd; 1445 struct pmc_cpu *pc; 1446 struct pmc_hw *phw __diagused; 1447 struct pmc_process *pp; 1448 struct pmc_thread *pt; 1449 struct proc *p; 1450 pmc_value_t newvalue; 1451 int cpu; 1452 u_int adjri, ri; 1453 1454 p = td->td_proc; 1455 pt = NULL; 1456 if ((pp = pmc_find_process_descriptor(p, PMC_FLAG_NONE)) == NULL) 1457 return; 1458 1459 KASSERT(pp->pp_proc == td->td_proc, 1460 ("[pmc,%d] not my thread state", __LINE__)); 1461 1462 critical_enter(); /* no preemption from this point */ 1463 1464 cpu = PCPU_GET(cpuid); /* td->td_oncpu is invalid */ 1465 1466 PMCDBG5(CSW,SWI,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p, 1467 p->p_pid, p->p_comm, pp); 1468 1469 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 1470 ("[pmc,%d] weird CPU id %d", __LINE__, cpu)); 1471 1472 pc = pmc_pcpu[cpu]; 1473 for (ri = 0; ri < md->pmd_npmc; ri++) { 1474 if ((pm = pp->pp_pmcs[ri].pp_pmc) == NULL) 1475 continue; 1476 1477 KASSERT(PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)), 1478 ("[pmc,%d] Target PMC in non-virtual mode (%d)", 1479 __LINE__, PMC_TO_MODE(pm))); 1480 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 1481 ("[pmc,%d] Row index mismatch pmc %d != ri %d", 1482 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 1483 1484 /* 1485 * Only PMCs that are marked as 'RUNNING' need 1486 * be placed on hardware. 1487 */ 1488 if (pm->pm_state != PMC_STATE_RUNNING) 1489 continue; 1490 1491 KASSERT(counter_u64_fetch(pm->pm_runcount) >= 0, 1492 ("[pmc,%d] pm=%p runcount %ju", __LINE__, pm, 1493 (uintmax_t)counter_u64_fetch(pm->pm_runcount))); 1494 1495 /* increment PMC runcount */ 1496 counter_u64_add(pm->pm_runcount, 1); 1497 1498 /* configure the HWPMC we are going to use. */ 1499 pcd = pmc_ri_to_classdep(md, ri, &adjri); 1500 (void)pcd->pcd_config_pmc(cpu, adjri, pm); 1501 1502 phw = pc->pc_hwpmcs[ri]; 1503 1504 KASSERT(phw != NULL, 1505 ("[pmc,%d] null hw pointer", __LINE__)); 1506 1507 KASSERT(phw->phw_pmc == pm, 1508 ("[pmc,%d] hw->pmc %p != pmc %p", __LINE__, 1509 phw->phw_pmc, pm)); 1510 1511 /* 1512 * Write out saved value and start the PMC. 1513 * 1514 * Sampling PMCs use a per-thread value, while 1515 * counting mode PMCs use a per-pmc value that is 1516 * inherited across descendants. 1517 */ 1518 if (PMC_TO_MODE(pm) == PMC_MODE_TS) { 1519 if (pt == NULL) 1520 pt = pmc_find_thread_descriptor(pp, td, 1521 PMC_FLAG_NONE); 1522 1523 KASSERT(pt != NULL, 1524 ("[pmc,%d] No thread found for td=%p", __LINE__, 1525 td)); 1526 1527 mtx_pool_lock_spin(pmc_mtxpool, pm); 1528 1529 /* 1530 * If we have a thread descriptor, use the per-thread 1531 * counter in the descriptor. If not, we will use 1532 * a per-process counter. 1533 * 1534 * TODO: Remove the per-process "safety net" once 1535 * we have thoroughly tested that we don't hit the 1536 * above assert. 1537 */ 1538 if (pt != NULL) { 1539 if (pt->pt_pmcs[ri].pt_pmcval > 0) 1540 newvalue = pt->pt_pmcs[ri].pt_pmcval; 1541 else 1542 newvalue = pm->pm_sc.pm_reloadcount; 1543 } else { 1544 /* 1545 * Use the saved value calculated after the most 1546 * recent time a thread using the shared counter 1547 * switched out. Reset the saved count in case 1548 * another thread from this process switches in 1549 * before any threads switch out. 1550 */ 1551 newvalue = pp->pp_pmcs[ri].pp_pmcval; 1552 pp->pp_pmcs[ri].pp_pmcval = 1553 pm->pm_sc.pm_reloadcount; 1554 } 1555 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1556 KASSERT(newvalue > 0 && newvalue <= 1557 pm->pm_sc.pm_reloadcount, 1558 ("[pmc,%d] pmcval outside of expected range cpu=%d " 1559 "ri=%d pmcval=%jx pm_reloadcount=%jx", __LINE__, 1560 cpu, ri, newvalue, pm->pm_sc.pm_reloadcount)); 1561 } else { 1562 KASSERT(PMC_TO_MODE(pm) == PMC_MODE_TC, 1563 ("[pmc,%d] illegal mode=%d", __LINE__, 1564 PMC_TO_MODE(pm))); 1565 mtx_pool_lock_spin(pmc_mtxpool, pm); 1566 newvalue = PMC_PCPU_SAVED(cpu, ri) = 1567 pm->pm_gv.pm_savedvalue; 1568 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1569 } 1570 1571 PMCDBG3(CSW,SWI,1,"cpu=%d ri=%d new=%jd", cpu, ri, newvalue); 1572 1573 (void)pcd->pcd_write_pmc(cpu, adjri, pm, newvalue); 1574 1575 /* If a sampling mode PMC, reset stalled state. */ 1576 if (PMC_TO_MODE(pm) == PMC_MODE_TS) 1577 pm->pm_pcpu_state[cpu].pps_stalled = 0; 1578 1579 /* Indicate that we desire this to run. */ 1580 pm->pm_pcpu_state[cpu].pps_cpustate = 1; 1581 1582 /* Start the PMC. */ 1583 (void)pcd->pcd_start_pmc(cpu, adjri, pm); 1584 } 1585 1586 /* 1587 * Perform any other architecture/cpu dependent thread 1588 * switch-in actions. 1589 */ 1590 (void)(*md->pmd_switch_in)(pc, pp); 1591 1592 critical_exit(); 1593 } 1594 1595 /* 1596 * Thread context switch OUT. 1597 */ 1598 static void 1599 pmc_process_csw_out(struct thread *td) 1600 { 1601 struct pmc *pm; 1602 struct pmc_classdep *pcd; 1603 struct pmc_cpu *pc; 1604 struct pmc_process *pp; 1605 struct pmc_thread *pt = NULL; 1606 struct proc *p; 1607 pmc_value_t newvalue; 1608 int64_t tmp; 1609 enum pmc_mode mode; 1610 int cpu; 1611 u_int adjri, ri; 1612 1613 /* 1614 * Locate our process descriptor; this may be NULL if 1615 * this process is exiting and we have already removed 1616 * the process from the target process table. 1617 * 1618 * Note that due to kernel preemption, multiple 1619 * context switches may happen while the process is 1620 * exiting. 1621 * 1622 * Note also that if the target process cannot be 1623 * found we still need to deconfigure any PMCs that 1624 * are currently running on hardware. 1625 */ 1626 p = td->td_proc; 1627 pp = pmc_find_process_descriptor(p, PMC_FLAG_NONE); 1628 1629 critical_enter(); 1630 1631 cpu = PCPU_GET(cpuid); /* td->td_oncpu is invalid */ 1632 1633 PMCDBG5(CSW,SWO,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p, 1634 p->p_pid, p->p_comm, pp); 1635 1636 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 1637 ("[pmc,%d weird CPU id %d", __LINE__, cpu)); 1638 1639 pc = pmc_pcpu[cpu]; 1640 1641 /* 1642 * When a PMC gets unlinked from a target PMC, it will 1643 * be removed from the target's pp_pmc[] array. 1644 * 1645 * However, on a MP system, the target could have been 1646 * executing on another CPU at the time of the unlink. 1647 * So, at context switch OUT time, we need to look at 1648 * the hardware to determine if a PMC is scheduled on 1649 * it. 1650 */ 1651 for (ri = 0; ri < md->pmd_npmc; ri++) { 1652 pcd = pmc_ri_to_classdep(md, ri, &adjri); 1653 pm = NULL; 1654 (void)(*pcd->pcd_get_config)(cpu, adjri, &pm); 1655 1656 if (pm == NULL) /* nothing at this row index */ 1657 continue; 1658 1659 mode = PMC_TO_MODE(pm); 1660 if (!PMC_IS_VIRTUAL_MODE(mode)) 1661 continue; /* not a process virtual PMC */ 1662 1663 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 1664 ("[pmc,%d] ri mismatch pmc(%d) ri(%d)", 1665 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 1666 1667 /* 1668 * Change desired state, and then stop if not stalled. 1669 * This two-step dance should avoid race conditions where 1670 * an interrupt re-enables the PMC after this code has 1671 * already checked the pm_stalled flag. 1672 */ 1673 pm->pm_pcpu_state[cpu].pps_cpustate = 0; 1674 if (pm->pm_pcpu_state[cpu].pps_stalled == 0) 1675 (void)pcd->pcd_stop_pmc(cpu, adjri, pm); 1676 1677 KASSERT(counter_u64_fetch(pm->pm_runcount) > 0, 1678 ("[pmc,%d] pm=%p runcount %ju", __LINE__, pm, 1679 (uintmax_t)counter_u64_fetch(pm->pm_runcount))); 1680 1681 /* reduce this PMC's runcount */ 1682 counter_u64_add(pm->pm_runcount, -1); 1683 1684 /* 1685 * If this PMC is associated with this process, 1686 * save the reading. 1687 */ 1688 if (pm->pm_state != PMC_STATE_DELETED && pp != NULL && 1689 pp->pp_pmcs[ri].pp_pmc != NULL) { 1690 KASSERT(pm == pp->pp_pmcs[ri].pp_pmc, 1691 ("[pmc,%d] pm %p != pp_pmcs[%d] %p", __LINE__, 1692 pm, ri, pp->pp_pmcs[ri].pp_pmc)); 1693 KASSERT(pp->pp_refcnt > 0, 1694 ("[pmc,%d] pp refcnt = %d", __LINE__, 1695 pp->pp_refcnt)); 1696 1697 (void)pcd->pcd_read_pmc(cpu, adjri, pm, &newvalue); 1698 1699 if (mode == PMC_MODE_TS) { 1700 PMCDBG3(CSW,SWO,1,"cpu=%d ri=%d val=%jd (samp)", 1701 cpu, ri, newvalue); 1702 1703 if (pt == NULL) 1704 pt = pmc_find_thread_descriptor(pp, td, 1705 PMC_FLAG_NONE); 1706 1707 KASSERT(pt != NULL, 1708 ("[pmc,%d] No thread found for td=%p", 1709 __LINE__, td)); 1710 1711 mtx_pool_lock_spin(pmc_mtxpool, pm); 1712 1713 /* 1714 * If we have a thread descriptor, save the 1715 * per-thread counter in the descriptor. If not, 1716 * we will update the per-process counter. 1717 * 1718 * TODO: Remove the per-process "safety net" 1719 * once we have thoroughly tested that we 1720 * don't hit the above assert. 1721 */ 1722 if (pt != NULL) { 1723 pt->pt_pmcs[ri].pt_pmcval = newvalue; 1724 } else { 1725 /* 1726 * For sampling process-virtual PMCs, 1727 * newvalue is the number of events to 1728 * be seen until the next sampling 1729 * interrupt. We can just add the events 1730 * left from this invocation to the 1731 * counter, then adjust in case we 1732 * overflow our range. 1733 * 1734 * (Recall that we reload the counter 1735 * every time we use it.) 1736 */ 1737 pp->pp_pmcs[ri].pp_pmcval += newvalue; 1738 if (pp->pp_pmcs[ri].pp_pmcval > 1739 pm->pm_sc.pm_reloadcount) { 1740 pp->pp_pmcs[ri].pp_pmcval -= 1741 pm->pm_sc.pm_reloadcount; 1742 } 1743 } 1744 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1745 } else { 1746 tmp = newvalue - PMC_PCPU_SAVED(cpu, ri); 1747 1748 PMCDBG3(CSW,SWO,1,"cpu=%d ri=%d tmp=%jd (count)", 1749 cpu, ri, tmp); 1750 1751 /* 1752 * For counting process-virtual PMCs, 1753 * we expect the count to be 1754 * increasing monotonically, modulo a 64 1755 * bit wraparound. 1756 */ 1757 KASSERT(tmp >= 0, 1758 ("[pmc,%d] negative increment cpu=%d " 1759 "ri=%d newvalue=%jx saved=%jx " 1760 "incr=%jx", __LINE__, cpu, ri, 1761 newvalue, PMC_PCPU_SAVED(cpu, ri), tmp)); 1762 1763 mtx_pool_lock_spin(pmc_mtxpool, pm); 1764 pm->pm_gv.pm_savedvalue += tmp; 1765 pp->pp_pmcs[ri].pp_pmcval += tmp; 1766 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1767 1768 if (pm->pm_flags & PMC_F_LOG_PROCCSW) 1769 pmclog_process_proccsw(pm, pp, tmp, td); 1770 } 1771 } 1772 1773 /* Mark hardware as free. */ 1774 (void)pcd->pcd_config_pmc(cpu, adjri, NULL); 1775 } 1776 1777 /* 1778 * Perform any other architecture/cpu dependent thread 1779 * switch out functions. 1780 */ 1781 (void)(*md->pmd_switch_out)(pc, pp); 1782 1783 critical_exit(); 1784 } 1785 1786 /* 1787 * A new thread for a process. 1788 */ 1789 static void 1790 pmc_process_thread_add(struct thread *td) 1791 { 1792 struct pmc_process *pmc; 1793 1794 pmc = pmc_find_process_descriptor(td->td_proc, PMC_FLAG_NONE); 1795 if (pmc != NULL) 1796 pmc_find_thread_descriptor(pmc, td, PMC_FLAG_ALLOCATE); 1797 } 1798 1799 /* 1800 * A thread delete for a process. 1801 */ 1802 static void 1803 pmc_process_thread_delete(struct thread *td) 1804 { 1805 struct pmc_process *pmc; 1806 1807 pmc = pmc_find_process_descriptor(td->td_proc, PMC_FLAG_NONE); 1808 if (pmc != NULL) 1809 pmc_thread_descriptor_pool_free(pmc_find_thread_descriptor(pmc, 1810 td, PMC_FLAG_REMOVE)); 1811 } 1812 1813 /* 1814 * A userret() call for a thread. 1815 */ 1816 static void 1817 pmc_process_thread_userret(struct thread *td) 1818 { 1819 sched_pin(); 1820 pmc_capture_user_callchain(curcpu, PMC_UR, td->td_frame); 1821 sched_unpin(); 1822 } 1823 1824 /* 1825 * A mapping change for a process. 1826 */ 1827 static void 1828 pmc_process_mmap(struct thread *td, struct pmckern_map_in *pkm) 1829 { 1830 const struct pmc *pm; 1831 const struct pmc_process *pp; 1832 struct pmc_owner *po; 1833 char *fullpath, *freepath; 1834 pid_t pid; 1835 int ri; 1836 1837 MPASS(!in_epoch(global_epoch_preempt)); 1838 1839 freepath = fullpath = NULL; 1840 pmc_getfilename((struct vnode *)pkm->pm_file, &fullpath, &freepath); 1841 1842 pid = td->td_proc->p_pid; 1843 1844 PMC_EPOCH_ENTER(); 1845 /* Inform owners of all system-wide sampling PMCs. */ 1846 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) { 1847 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1848 pmclog_process_map_in(po, pid, pkm->pm_address, 1849 fullpath); 1850 } 1851 1852 if ((pp = pmc_find_process_descriptor(td->td_proc, 0)) == NULL) 1853 goto done; 1854 1855 /* 1856 * Inform sampling PMC owners tracking this process. 1857 */ 1858 for (ri = 0; ri < md->pmd_npmc; ri++) { 1859 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL && 1860 PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) { 1861 pmclog_process_map_in(pm->pm_owner, 1862 pid, pkm->pm_address, fullpath); 1863 } 1864 } 1865 1866 done: 1867 if (freepath != NULL) 1868 free(freepath, M_TEMP); 1869 PMC_EPOCH_EXIT(); 1870 } 1871 1872 /* 1873 * Log an munmap request. 1874 */ 1875 static void 1876 pmc_process_munmap(struct thread *td, struct pmckern_map_out *pkm) 1877 { 1878 const struct pmc *pm; 1879 const struct pmc_process *pp; 1880 struct pmc_owner *po; 1881 pid_t pid; 1882 int ri; 1883 1884 pid = td->td_proc->p_pid; 1885 1886 PMC_EPOCH_ENTER(); 1887 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) { 1888 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1889 pmclog_process_map_out(po, pid, pkm->pm_address, 1890 pkm->pm_address + pkm->pm_size); 1891 } 1892 PMC_EPOCH_EXIT(); 1893 1894 if ((pp = pmc_find_process_descriptor(td->td_proc, 0)) == NULL) 1895 return; 1896 1897 for (ri = 0; ri < md->pmd_npmc; ri++) { 1898 pm = pp->pp_pmcs[ri].pp_pmc; 1899 if (pm != NULL && PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) { 1900 pmclog_process_map_out(pm->pm_owner, pid, 1901 pkm->pm_address, pkm->pm_address + pkm->pm_size); 1902 } 1903 } 1904 } 1905 1906 /* 1907 * Log mapping information about the kernel. 1908 */ 1909 static void 1910 pmc_log_kernel_mappings(struct pmc *pm) 1911 { 1912 struct pmc_owner *po; 1913 struct pmckern_map_in *km, *kmbase; 1914 1915 MPASS(in_epoch(global_epoch_preempt) || sx_xlocked(&pmc_sx)); 1916 KASSERT(PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)), 1917 ("[pmc,%d] non-sampling PMC (%p) desires mapping information", 1918 __LINE__, (void *) pm)); 1919 1920 po = pm->pm_owner; 1921 if ((po->po_flags & PMC_PO_INITIAL_MAPPINGS_DONE) != 0) 1922 return; 1923 1924 if (PMC_TO_MODE(pm) == PMC_MODE_SS) 1925 pmc_process_allproc(pm); 1926 1927 /* 1928 * Log the current set of kernel modules. 1929 */ 1930 kmbase = linker_hwpmc_list_objects(); 1931 for (km = kmbase; km->pm_file != NULL; km++) { 1932 PMCDBG2(LOG,REG,1,"%s %p", (char *)km->pm_file, 1933 (void *)km->pm_address); 1934 pmclog_process_map_in(po, (pid_t)-1, km->pm_address, 1935 km->pm_file); 1936 } 1937 free(kmbase, M_LINKER); 1938 1939 po->po_flags |= PMC_PO_INITIAL_MAPPINGS_DONE; 1940 } 1941 1942 /* 1943 * Log the mappings for a single process. 1944 */ 1945 static void 1946 pmc_log_process_mappings(struct pmc_owner *po, struct proc *p) 1947 { 1948 vm_map_t map; 1949 vm_map_entry_t entry; 1950 vm_object_t obj, lobj, tobj; 1951 vm_offset_t last_end; 1952 vm_offset_t start_addr; 1953 struct vnode *vp, *last_vp; 1954 struct vmspace *vm; 1955 char *fullpath, *freepath; 1956 u_int last_timestamp; 1957 1958 last_vp = NULL; 1959 last_end = (vm_offset_t)0; 1960 fullpath = freepath = NULL; 1961 1962 if ((vm = vmspace_acquire_ref(p)) == NULL) 1963 return; 1964 1965 map = &vm->vm_map; 1966 vm_map_lock_read(map); 1967 VM_MAP_ENTRY_FOREACH(entry, map) { 1968 if (entry == NULL) { 1969 PMCDBG2(LOG,OPS,2, "hwpmc: vm_map entry unexpectedly " 1970 "NULL! pid=%d vm_map=%p\n", p->p_pid, map); 1971 break; 1972 } 1973 1974 /* 1975 * We only care about executable map entries. 1976 */ 1977 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0 || 1978 (entry->protection & VM_PROT_EXECUTE) == 0 || 1979 entry->object.vm_object == NULL) { 1980 continue; 1981 } 1982 1983 obj = entry->object.vm_object; 1984 VM_OBJECT_RLOCK(obj); 1985 1986 /* 1987 * Walk the backing_object list to find the base (non-shadowed) 1988 * vm_object. 1989 */ 1990 for (lobj = tobj = obj; tobj != NULL; 1991 tobj = tobj->backing_object) { 1992 if (tobj != obj) 1993 VM_OBJECT_RLOCK(tobj); 1994 if (lobj != obj) 1995 VM_OBJECT_RUNLOCK(lobj); 1996 lobj = tobj; 1997 } 1998 1999 /* 2000 * At this point lobj is the base vm_object and it is locked. 2001 */ 2002 if (lobj == NULL) { 2003 PMCDBG3(LOG,OPS,2, 2004 "hwpmc: lobj unexpectedly NULL! pid=%d " 2005 "vm_map=%p vm_obj=%p\n", p->p_pid, map, obj); 2006 VM_OBJECT_RUNLOCK(obj); 2007 continue; 2008 } 2009 2010 vp = vm_object_vnode(lobj); 2011 if (vp == NULL) { 2012 if (lobj != obj) 2013 VM_OBJECT_RUNLOCK(lobj); 2014 VM_OBJECT_RUNLOCK(obj); 2015 continue; 2016 } 2017 2018 /* 2019 * Skip contiguous regions that point to the same vnode, so we 2020 * don't emit redundant MAP-IN directives. 2021 */ 2022 if (entry->start == last_end && vp == last_vp) { 2023 last_end = entry->end; 2024 if (lobj != obj) 2025 VM_OBJECT_RUNLOCK(lobj); 2026 VM_OBJECT_RUNLOCK(obj); 2027 continue; 2028 } 2029 2030 /* 2031 * We don't want to keep the proc's vm_map or this vm_object 2032 * locked while we walk the pathname, since vn_fullpath() can 2033 * sleep. However, if we drop the lock, it's possible for 2034 * concurrent activity to modify the vm_map list. To protect 2035 * against this, we save the vm_map timestamp before we release 2036 * the lock, and check it after we reacquire the lock below. 2037 */ 2038 start_addr = entry->start; 2039 last_end = entry->end; 2040 last_timestamp = map->timestamp; 2041 vm_map_unlock_read(map); 2042 2043 vref(vp); 2044 if (lobj != obj) 2045 VM_OBJECT_RUNLOCK(lobj); 2046 VM_OBJECT_RUNLOCK(obj); 2047 2048 freepath = NULL; 2049 pmc_getfilename(vp, &fullpath, &freepath); 2050 last_vp = vp; 2051 2052 vrele(vp); 2053 2054 vp = NULL; 2055 pmclog_process_map_in(po, p->p_pid, start_addr, fullpath); 2056 if (freepath != NULL) 2057 free(freepath, M_TEMP); 2058 2059 vm_map_lock_read(map); 2060 2061 /* 2062 * If our saved timestamp doesn't match, this means 2063 * that the vm_map was modified out from under us and 2064 * we can't trust our current "entry" pointer. Do a 2065 * new lookup for this entry. If there is no entry 2066 * for this address range, vm_map_lookup_entry() will 2067 * return the previous one, so we always want to go to 2068 * the next entry on the next loop iteration. 2069 * 2070 * There is an edge condition here that can occur if 2071 * there is no entry at or before this address. In 2072 * this situation, vm_map_lookup_entry returns 2073 * &map->header, which would cause our loop to abort 2074 * without processing the rest of the map. However, 2075 * in practice this will never happen for process 2076 * vm_map. This is because the executable's text 2077 * segment is the first mapping in the proc's address 2078 * space, and this mapping is never removed until the 2079 * process exits, so there will always be a non-header 2080 * entry at or before the requested address for 2081 * vm_map_lookup_entry to return. 2082 */ 2083 if (map->timestamp != last_timestamp) 2084 vm_map_lookup_entry(map, last_end - 1, &entry); 2085 } 2086 2087 vm_map_unlock_read(map); 2088 vmspace_free(vm); 2089 return; 2090 } 2091 2092 /* 2093 * Log mappings for all processes in the system. 2094 */ 2095 static void 2096 pmc_log_all_process_mappings(struct pmc_owner *po) 2097 { 2098 struct proc *p, *top; 2099 2100 sx_assert(&pmc_sx, SX_XLOCKED); 2101 2102 if ((p = pfind(1)) == NULL) 2103 panic("[pmc,%d] Cannot find init", __LINE__); 2104 2105 PROC_UNLOCK(p); 2106 2107 sx_slock(&proctree_lock); 2108 2109 top = p; 2110 for (;;) { 2111 pmc_log_process_mappings(po, p); 2112 if (!LIST_EMPTY(&p->p_children)) 2113 p = LIST_FIRST(&p->p_children); 2114 else for (;;) { 2115 if (p == top) 2116 goto done; 2117 if (LIST_NEXT(p, p_sibling)) { 2118 p = LIST_NEXT(p, p_sibling); 2119 break; 2120 } 2121 p = p->p_pptr; 2122 } 2123 } 2124 done: 2125 sx_sunlock(&proctree_lock); 2126 } 2127 2128 #ifdef HWPMC_DEBUG 2129 const char *pmc_hooknames[] = { 2130 /* these strings correspond to PMC_FN_* in <sys/pmckern.h> */ 2131 "", 2132 "EXEC", 2133 "CSW-IN", 2134 "CSW-OUT", 2135 "SAMPLE", 2136 "UNUSED1", 2137 "UNUSED2", 2138 "MMAP", 2139 "MUNMAP", 2140 "CALLCHAIN-NMI", 2141 "CALLCHAIN-SOFT", 2142 "SOFTSAMPLING", 2143 "THR-CREATE", 2144 "THR-EXIT", 2145 "THR-USERRET", 2146 "THR-CREATE-LOG", 2147 "THR-EXIT-LOG", 2148 "PROC-CREATE-LOG" 2149 }; 2150 #endif 2151 2152 /* 2153 * The 'hook' invoked from the kernel proper 2154 */ 2155 static int 2156 pmc_hook_handler(struct thread *td, int function, void *arg) 2157 { 2158 int cpu; 2159 2160 PMCDBG4(MOD,PMH,1, "hook td=%p func=%d \"%s\" arg=%p", td, function, 2161 pmc_hooknames[function], arg); 2162 2163 switch (function) { 2164 case PMC_FN_PROCESS_EXEC: 2165 pmc_process_exec(td, (struct pmckern_procexec *)arg); 2166 break; 2167 2168 case PMC_FN_CSW_IN: 2169 pmc_process_csw_in(td); 2170 break; 2171 2172 case PMC_FN_CSW_OUT: 2173 pmc_process_csw_out(td); 2174 break; 2175 2176 /* 2177 * Process accumulated PC samples. 2178 * 2179 * This function is expected to be called by hardclock() for 2180 * each CPU that has accumulated PC samples. 2181 * 2182 * This function is to be executed on the CPU whose samples 2183 * are being processed. 2184 */ 2185 case PMC_FN_DO_SAMPLES: 2186 /* 2187 * Clear the cpu specific bit in the CPU mask before 2188 * do the rest of the processing. If the NMI handler 2189 * gets invoked after the "atomic_clear_int()" call 2190 * below but before "pmc_process_samples()" gets 2191 * around to processing the interrupt, then we will 2192 * come back here at the next hardclock() tick (and 2193 * may find nothing to do if "pmc_process_samples()" 2194 * had already processed the interrupt). We don't 2195 * lose the interrupt sample. 2196 */ 2197 DPCPU_SET(pmc_sampled, 0); 2198 cpu = PCPU_GET(cpuid); 2199 pmc_process_samples(cpu, PMC_HR); 2200 pmc_process_samples(cpu, PMC_SR); 2201 pmc_process_samples(cpu, PMC_UR); 2202 break; 2203 2204 case PMC_FN_MMAP: 2205 pmc_process_mmap(td, (struct pmckern_map_in *)arg); 2206 break; 2207 2208 case PMC_FN_MUNMAP: 2209 MPASS(in_epoch(global_epoch_preempt) || sx_xlocked(&pmc_sx)); 2210 pmc_process_munmap(td, (struct pmckern_map_out *)arg); 2211 break; 2212 2213 case PMC_FN_PROC_CREATE_LOG: 2214 pmc_process_proccreate((struct proc *)arg); 2215 break; 2216 2217 case PMC_FN_USER_CALLCHAIN: 2218 /* 2219 * Record a call chain. 2220 */ 2221 KASSERT(td == curthread, ("[pmc,%d] td != curthread", 2222 __LINE__)); 2223 2224 pmc_capture_user_callchain(PCPU_GET(cpuid), PMC_HR, 2225 (struct trapframe *)arg); 2226 2227 KASSERT(td->td_pinned == 1, 2228 ("[pmc,%d] invalid td_pinned value", __LINE__)); 2229 sched_unpin(); /* Can migrate safely now. */ 2230 2231 td->td_pflags &= ~TDP_CALLCHAIN; 2232 break; 2233 2234 case PMC_FN_USER_CALLCHAIN_SOFT: 2235 /* 2236 * Record a call chain. 2237 */ 2238 KASSERT(td == curthread, ("[pmc,%d] td != curthread", 2239 __LINE__)); 2240 2241 cpu = PCPU_GET(cpuid); 2242 pmc_capture_user_callchain(cpu, PMC_SR, 2243 (struct trapframe *) arg); 2244 2245 KASSERT(td->td_pinned == 1, 2246 ("[pmc,%d] invalid td_pinned value", __LINE__)); 2247 2248 sched_unpin(); /* Can migrate safely now. */ 2249 2250 td->td_pflags &= ~TDP_CALLCHAIN; 2251 break; 2252 2253 case PMC_FN_SOFT_SAMPLING: 2254 /* 2255 * Call soft PMC sampling intr. 2256 */ 2257 pmc_soft_intr((struct pmckern_soft *)arg); 2258 break; 2259 2260 case PMC_FN_THR_CREATE: 2261 pmc_process_thread_add(td); 2262 pmc_process_threadcreate(td); 2263 break; 2264 2265 case PMC_FN_THR_CREATE_LOG: 2266 pmc_process_threadcreate(td); 2267 break; 2268 2269 case PMC_FN_THR_EXIT: 2270 KASSERT(td == curthread, ("[pmc,%d] td != curthread", 2271 __LINE__)); 2272 pmc_process_thread_delete(td); 2273 pmc_process_threadexit(td); 2274 break; 2275 case PMC_FN_THR_EXIT_LOG: 2276 pmc_process_threadexit(td); 2277 break; 2278 case PMC_FN_THR_USERRET: 2279 KASSERT(td == curthread, ("[pmc,%d] td != curthread", 2280 __LINE__)); 2281 pmc_process_thread_userret(td); 2282 break; 2283 default: 2284 #ifdef HWPMC_DEBUG 2285 KASSERT(0, ("[pmc,%d] unknown hook %d\n", __LINE__, function)); 2286 #endif 2287 break; 2288 } 2289 2290 return (0); 2291 } 2292 2293 /* 2294 * Allocate a 'struct pmc_owner' descriptor in the owner hash table. 2295 */ 2296 static struct pmc_owner * 2297 pmc_allocate_owner_descriptor(struct proc *p) 2298 { 2299 struct pmc_owner *po; 2300 struct pmc_ownerhash *poh; 2301 uint32_t hindex; 2302 2303 hindex = PMC_HASH_PTR(p, pmc_ownerhashmask); 2304 poh = &pmc_ownerhash[hindex]; 2305 2306 /* Allocate space for N pointers and one descriptor struct. */ 2307 po = malloc(sizeof(struct pmc_owner), M_PMC, M_WAITOK | M_ZERO); 2308 po->po_owner = p; 2309 LIST_INSERT_HEAD(poh, po, po_next); /* insert into hash table */ 2310 2311 TAILQ_INIT(&po->po_logbuffers); 2312 mtx_init(&po->po_mtx, "pmc-owner-mtx", "pmc-per-proc", MTX_SPIN); 2313 2314 PMCDBG4(OWN,ALL,1, "allocate-owner proc=%p (%d, %s) pmc-owner=%p", 2315 p, p->p_pid, p->p_comm, po); 2316 2317 return (po); 2318 } 2319 2320 static void 2321 pmc_destroy_owner_descriptor(struct pmc_owner *po) 2322 { 2323 2324 PMCDBG4(OWN,REL,1, "destroy-owner po=%p proc=%p (%d, %s)", 2325 po, po->po_owner, po->po_owner->p_pid, po->po_owner->p_comm); 2326 2327 mtx_destroy(&po->po_mtx); 2328 free(po, M_PMC); 2329 } 2330 2331 /* 2332 * Allocate a thread descriptor from the free pool. 2333 * 2334 * NOTE: This *can* return NULL. 2335 */ 2336 static struct pmc_thread * 2337 pmc_thread_descriptor_pool_alloc(void) 2338 { 2339 struct pmc_thread *pt; 2340 2341 mtx_lock_spin(&pmc_threadfreelist_mtx); 2342 if ((pt = LIST_FIRST(&pmc_threadfreelist)) != NULL) { 2343 LIST_REMOVE(pt, pt_next); 2344 pmc_threadfreelist_entries--; 2345 } 2346 mtx_unlock_spin(&pmc_threadfreelist_mtx); 2347 2348 return (pt); 2349 } 2350 2351 /* 2352 * Add a thread descriptor to the free pool. We use this instead of free() 2353 * to maintain a cache of free entries. Additionally, we can safely call 2354 * this function when we cannot call free(), such as in a critical section. 2355 */ 2356 static void 2357 pmc_thread_descriptor_pool_free(struct pmc_thread *pt) 2358 { 2359 2360 if (pt == NULL) 2361 return; 2362 2363 memset(pt, 0, THREADENTRY_SIZE); 2364 mtx_lock_spin(&pmc_threadfreelist_mtx); 2365 LIST_INSERT_HEAD(&pmc_threadfreelist, pt, pt_next); 2366 pmc_threadfreelist_entries++; 2367 if (pmc_threadfreelist_entries > pmc_threadfreelist_max) 2368 taskqueue_enqueue(taskqueue_fast, &free_task); 2369 mtx_unlock_spin(&pmc_threadfreelist_mtx); 2370 } 2371 2372 /* 2373 * An asynchronous task to manage the free list. 2374 */ 2375 static void 2376 pmc_thread_descriptor_pool_free_task(void *arg __unused, int pending __unused) 2377 { 2378 struct pmc_thread *pt; 2379 LIST_HEAD(, pmc_thread) tmplist; 2380 int delta; 2381 2382 LIST_INIT(&tmplist); 2383 2384 /* Determine what changes, if any, we need to make. */ 2385 mtx_lock_spin(&pmc_threadfreelist_mtx); 2386 delta = pmc_threadfreelist_entries - pmc_threadfreelist_max; 2387 while (delta > 0 && (pt = LIST_FIRST(&pmc_threadfreelist)) != NULL) { 2388 delta--; 2389 pmc_threadfreelist_entries--; 2390 LIST_REMOVE(pt, pt_next); 2391 LIST_INSERT_HEAD(&tmplist, pt, pt_next); 2392 } 2393 mtx_unlock_spin(&pmc_threadfreelist_mtx); 2394 2395 /* If there are entries to free, free them. */ 2396 while (!LIST_EMPTY(&tmplist)) { 2397 pt = LIST_FIRST(&tmplist); 2398 LIST_REMOVE(pt, pt_next); 2399 free(pt, M_PMC); 2400 } 2401 } 2402 2403 /* 2404 * Drain the thread free pool, freeing all allocations. 2405 */ 2406 static void 2407 pmc_thread_descriptor_pool_drain(void) 2408 { 2409 struct pmc_thread *pt, *next; 2410 2411 LIST_FOREACH_SAFE(pt, &pmc_threadfreelist, pt_next, next) { 2412 LIST_REMOVE(pt, pt_next); 2413 free(pt, M_PMC); 2414 } 2415 } 2416 2417 /* 2418 * find the descriptor corresponding to thread 'td', adding or removing it 2419 * as specified by 'mode'. 2420 * 2421 * Note that this supports additional mode flags in addition to those 2422 * supported by pmc_find_process_descriptor(): 2423 * PMC_FLAG_NOWAIT: Causes the function to not wait for mallocs. 2424 * This makes it safe to call while holding certain other locks. 2425 */ 2426 static struct pmc_thread * 2427 pmc_find_thread_descriptor(struct pmc_process *pp, struct thread *td, 2428 uint32_t mode) 2429 { 2430 struct pmc_thread *pt = NULL, *ptnew = NULL; 2431 int wait_flag; 2432 2433 KASSERT(td != NULL, ("[pmc,%d] called to add NULL td", __LINE__)); 2434 2435 /* 2436 * Pre-allocate memory in the PMC_FLAG_ALLOCATE case prior to 2437 * acquiring the lock. 2438 */ 2439 if ((mode & PMC_FLAG_ALLOCATE) != 0) { 2440 if ((ptnew = pmc_thread_descriptor_pool_alloc()) == NULL) { 2441 wait_flag = M_WAITOK; 2442 if ((mode & PMC_FLAG_NOWAIT) != 0 || 2443 in_epoch(global_epoch_preempt)) 2444 wait_flag = M_NOWAIT; 2445 2446 ptnew = malloc(THREADENTRY_SIZE, M_PMC, 2447 wait_flag | M_ZERO); 2448 } 2449 } 2450 2451 mtx_lock_spin(pp->pp_tdslock); 2452 LIST_FOREACH(pt, &pp->pp_tds, pt_next) { 2453 if (pt->pt_td == td) 2454 break; 2455 } 2456 2457 if ((mode & PMC_FLAG_REMOVE) != 0 && pt != NULL) 2458 LIST_REMOVE(pt, pt_next); 2459 2460 if ((mode & PMC_FLAG_ALLOCATE) != 0 && pt == NULL && ptnew != NULL) { 2461 pt = ptnew; 2462 ptnew = NULL; 2463 pt->pt_td = td; 2464 LIST_INSERT_HEAD(&pp->pp_tds, pt, pt_next); 2465 } 2466 2467 mtx_unlock_spin(pp->pp_tdslock); 2468 2469 if (ptnew != NULL) { 2470 free(ptnew, M_PMC); 2471 } 2472 2473 return (pt); 2474 } 2475 2476 /* 2477 * Try to add thread descriptors for each thread in a process. 2478 */ 2479 static void 2480 pmc_add_thread_descriptors_from_proc(struct proc *p, struct pmc_process *pp) 2481 { 2482 struct pmc_thread **tdlist; 2483 struct thread *curtd; 2484 int i, tdcnt, tdlistsz; 2485 2486 KASSERT(!PROC_LOCKED(p), ("[pmc,%d] proc unexpectedly locked", 2487 __LINE__)); 2488 tdcnt = 32; 2489 restart: 2490 tdlistsz = roundup2(tdcnt, 32); 2491 2492 tdcnt = 0; 2493 tdlist = malloc(sizeof(struct pmc_thread *) * tdlistsz, M_TEMP, 2494 M_WAITOK); 2495 2496 PROC_LOCK(p); 2497 FOREACH_THREAD_IN_PROC(p, curtd) 2498 tdcnt++; 2499 if (tdcnt >= tdlistsz) { 2500 PROC_UNLOCK(p); 2501 free(tdlist, M_TEMP); 2502 goto restart; 2503 } 2504 2505 /* 2506 * Try to add each thread to the list without sleeping. If unable, 2507 * add to a queue to retry after dropping the process lock. 2508 */ 2509 tdcnt = 0; 2510 FOREACH_THREAD_IN_PROC(p, curtd) { 2511 tdlist[tdcnt] = pmc_find_thread_descriptor(pp, curtd, 2512 PMC_FLAG_ALLOCATE | PMC_FLAG_NOWAIT); 2513 if (tdlist[tdcnt] == NULL) { 2514 PROC_UNLOCK(p); 2515 for (i = 0; i <= tdcnt; i++) 2516 pmc_thread_descriptor_pool_free(tdlist[i]); 2517 free(tdlist, M_TEMP); 2518 goto restart; 2519 } 2520 tdcnt++; 2521 } 2522 PROC_UNLOCK(p); 2523 free(tdlist, M_TEMP); 2524 } 2525 2526 /* 2527 * Find the descriptor corresponding to process 'p', adding or removing it 2528 * as specified by 'mode'. 2529 */ 2530 static struct pmc_process * 2531 pmc_find_process_descriptor(struct proc *p, uint32_t mode) 2532 { 2533 struct pmc_process *pp, *ppnew; 2534 struct pmc_processhash *pph; 2535 uint32_t hindex; 2536 2537 hindex = PMC_HASH_PTR(p, pmc_processhashmask); 2538 pph = &pmc_processhash[hindex]; 2539 2540 ppnew = NULL; 2541 2542 /* 2543 * Pre-allocate memory in the PMC_FLAG_ALLOCATE case since we 2544 * cannot call malloc(9) once we hold a spin lock. 2545 */ 2546 if ((mode & PMC_FLAG_ALLOCATE) != 0) 2547 ppnew = malloc(sizeof(struct pmc_process) + md->pmd_npmc * 2548 sizeof(struct pmc_targetstate), M_PMC, M_WAITOK | M_ZERO); 2549 2550 mtx_lock_spin(&pmc_processhash_mtx); 2551 LIST_FOREACH(pp, pph, pp_next) { 2552 if (pp->pp_proc == p) 2553 break; 2554 } 2555 2556 if ((mode & PMC_FLAG_REMOVE) != 0 && pp != NULL) 2557 LIST_REMOVE(pp, pp_next); 2558 2559 if ((mode & PMC_FLAG_ALLOCATE) != 0 && pp == NULL && ppnew != NULL) { 2560 ppnew->pp_proc = p; 2561 LIST_INIT(&ppnew->pp_tds); 2562 ppnew->pp_tdslock = mtx_pool_find(pmc_mtxpool, ppnew); 2563 LIST_INSERT_HEAD(pph, ppnew, pp_next); 2564 mtx_unlock_spin(&pmc_processhash_mtx); 2565 pp = ppnew; 2566 ppnew = NULL; 2567 2568 /* Add thread descriptors for this process' current threads. */ 2569 pmc_add_thread_descriptors_from_proc(p, pp); 2570 } else 2571 mtx_unlock_spin(&pmc_processhash_mtx); 2572 2573 if (ppnew != NULL) 2574 free(ppnew, M_PMC); 2575 return (pp); 2576 } 2577 2578 /* 2579 * Remove a process descriptor from the process hash table. 2580 */ 2581 static void 2582 pmc_remove_process_descriptor(struct pmc_process *pp) 2583 { 2584 KASSERT(pp->pp_refcnt == 0, 2585 ("[pmc,%d] Removing process descriptor %p with count %d", 2586 __LINE__, pp, pp->pp_refcnt)); 2587 2588 mtx_lock_spin(&pmc_processhash_mtx); 2589 LIST_REMOVE(pp, pp_next); 2590 mtx_unlock_spin(&pmc_processhash_mtx); 2591 } 2592 2593 /* 2594 * Destroy a process descriptor. 2595 */ 2596 static void 2597 pmc_destroy_process_descriptor(struct pmc_process *pp) 2598 { 2599 struct pmc_thread *pmc_td; 2600 2601 while ((pmc_td = LIST_FIRST(&pp->pp_tds)) != NULL) { 2602 LIST_REMOVE(pmc_td, pt_next); 2603 pmc_thread_descriptor_pool_free(pmc_td); 2604 } 2605 free(pp, M_PMC); 2606 } 2607 2608 /* 2609 * Find an owner descriptor corresponding to proc 'p'. 2610 */ 2611 static struct pmc_owner * 2612 pmc_find_owner_descriptor(struct proc *p) 2613 { 2614 struct pmc_owner *po; 2615 struct pmc_ownerhash *poh; 2616 uint32_t hindex; 2617 2618 hindex = PMC_HASH_PTR(p, pmc_ownerhashmask); 2619 poh = &pmc_ownerhash[hindex]; 2620 2621 po = NULL; 2622 LIST_FOREACH(po, poh, po_next) { 2623 if (po->po_owner == p) 2624 break; 2625 } 2626 2627 PMCDBG5(OWN,FND,1, "find-owner proc=%p (%d, %s) hindex=0x%x -> " 2628 "pmc-owner=%p", p, p->p_pid, p->p_comm, hindex, po); 2629 2630 return (po); 2631 } 2632 2633 /* 2634 * Allocate a pmc descriptor and initialize its fields. 2635 */ 2636 static struct pmc * 2637 pmc_allocate_pmc_descriptor(void) 2638 { 2639 struct pmc *pmc; 2640 2641 pmc = malloc(sizeof(struct pmc), M_PMC, M_WAITOK | M_ZERO); 2642 pmc->pm_runcount = counter_u64_alloc(M_WAITOK); 2643 pmc->pm_pcpu_state = malloc(sizeof(struct pmc_pcpu_state) * mp_ncpus, 2644 M_PMC, M_WAITOK | M_ZERO); 2645 PMCDBG1(PMC,ALL,1, "allocate-pmc -> pmc=%p", pmc); 2646 2647 return (pmc); 2648 } 2649 2650 /* 2651 * Destroy a pmc descriptor. 2652 */ 2653 static void 2654 pmc_destroy_pmc_descriptor(struct pmc *pm) 2655 { 2656 2657 KASSERT(pm->pm_state == PMC_STATE_DELETED || 2658 pm->pm_state == PMC_STATE_FREE, 2659 ("[pmc,%d] destroying non-deleted PMC", __LINE__)); 2660 KASSERT(LIST_EMPTY(&pm->pm_targets), 2661 ("[pmc,%d] destroying pmc with targets", __LINE__)); 2662 KASSERT(pm->pm_owner == NULL, 2663 ("[pmc,%d] destroying pmc attached to an owner", __LINE__)); 2664 KASSERT(counter_u64_fetch(pm->pm_runcount) == 0, 2665 ("[pmc,%d] pmc has non-zero run count %ju", __LINE__, 2666 (uintmax_t)counter_u64_fetch(pm->pm_runcount))); 2667 2668 counter_u64_free(pm->pm_runcount); 2669 free(pm->pm_pcpu_state, M_PMC); 2670 free(pm, M_PMC); 2671 } 2672 2673 static void 2674 pmc_wait_for_pmc_idle(struct pmc *pm) 2675 { 2676 #ifdef INVARIANTS 2677 volatile int maxloop; 2678 2679 maxloop = 100 * pmc_cpu_max(); 2680 #endif 2681 /* 2682 * Loop (with a forced context switch) till the PMC's runcount 2683 * comes down to zero. 2684 */ 2685 pmclog_flush(pm->pm_owner, 1); 2686 while (counter_u64_fetch(pm->pm_runcount) > 0) { 2687 pmclog_flush(pm->pm_owner, 1); 2688 #ifdef INVARIANTS 2689 maxloop--; 2690 KASSERT(maxloop > 0, 2691 ("[pmc,%d] (ri%d, rc%ju) waiting too long for " 2692 "pmc to be free", __LINE__, PMC_TO_ROWINDEX(pm), 2693 (uintmax_t)counter_u64_fetch(pm->pm_runcount))); 2694 #endif 2695 pmc_force_context_switch(); 2696 } 2697 } 2698 2699 /* 2700 * This function does the following things: 2701 * 2702 * - detaches the PMC from hardware 2703 * - unlinks all target threads that were attached to it 2704 * - removes the PMC from its owner's list 2705 * - destroys the PMC private mutex 2706 * 2707 * Once this function completes, the given pmc pointer can be freed by 2708 * calling pmc_destroy_pmc_descriptor(). 2709 */ 2710 static void 2711 pmc_release_pmc_descriptor(struct pmc *pm) 2712 { 2713 struct pmc_binding pb; 2714 struct pmc_classdep *pcd; 2715 struct pmc_hw *phw __diagused; 2716 struct pmc_owner *po; 2717 struct pmc_process *pp; 2718 struct pmc_target *ptgt, *tmp; 2719 enum pmc_mode mode; 2720 u_int adjri, ri, cpu; 2721 2722 sx_assert(&pmc_sx, SX_XLOCKED); 2723 KASSERT(pm, ("[pmc,%d] null pmc", __LINE__)); 2724 2725 ri = PMC_TO_ROWINDEX(pm); 2726 pcd = pmc_ri_to_classdep(md, ri, &adjri); 2727 mode = PMC_TO_MODE(pm); 2728 2729 PMCDBG3(PMC,REL,1, "release-pmc pmc=%p ri=%d mode=%d", pm, ri, 2730 mode); 2731 2732 /* 2733 * First, we take the PMC off hardware. 2734 */ 2735 cpu = 0; 2736 if (PMC_IS_SYSTEM_MODE(mode)) { 2737 /* 2738 * A system mode PMC runs on a specific CPU. Switch 2739 * to this CPU and turn hardware off. 2740 */ 2741 pmc_save_cpu_binding(&pb); 2742 cpu = PMC_TO_CPU(pm); 2743 pmc_select_cpu(cpu); 2744 2745 /* switch off non-stalled CPUs */ 2746 pm->pm_pcpu_state[cpu].pps_cpustate = 0; 2747 if (pm->pm_state == PMC_STATE_RUNNING && 2748 pm->pm_pcpu_state[cpu].pps_stalled == 0) { 2749 2750 phw = pmc_pcpu[cpu]->pc_hwpmcs[ri]; 2751 2752 KASSERT(phw->phw_pmc == pm, 2753 ("[pmc, %d] pmc ptr ri(%d) hw(%p) pm(%p)", 2754 __LINE__, ri, phw->phw_pmc, pm)); 2755 PMCDBG2(PMC,REL,2, "stopping cpu=%d ri=%d", cpu, ri); 2756 2757 critical_enter(); 2758 (void)pcd->pcd_stop_pmc(cpu, adjri, pm); 2759 critical_exit(); 2760 } 2761 2762 PMCDBG2(PMC,REL,2, "decfg cpu=%d ri=%d", cpu, ri); 2763 2764 critical_enter(); 2765 (void)pcd->pcd_config_pmc(cpu, adjri, NULL); 2766 critical_exit(); 2767 2768 /* adjust the global and process count of SS mode PMCs */ 2769 if (mode == PMC_MODE_SS && pm->pm_state == PMC_STATE_RUNNING) { 2770 po = pm->pm_owner; 2771 po->po_sscount--; 2772 if (po->po_sscount == 0) { 2773 atomic_subtract_rel_int(&pmc_ss_count, 1); 2774 CK_LIST_REMOVE(po, po_ssnext); 2775 epoch_wait_preempt(global_epoch_preempt); 2776 } 2777 } 2778 pm->pm_state = PMC_STATE_DELETED; 2779 2780 pmc_restore_cpu_binding(&pb); 2781 2782 /* 2783 * We could have references to this PMC structure in the 2784 * per-cpu sample queues. Wait for the queue to drain. 2785 */ 2786 pmc_wait_for_pmc_idle(pm); 2787 2788 } else if (PMC_IS_VIRTUAL_MODE(mode)) { 2789 /* 2790 * A virtual PMC could be running on multiple CPUs at a given 2791 * instant. 2792 * 2793 * By marking its state as DELETED, we ensure that this PMC is 2794 * never further scheduled on hardware. 2795 * 2796 * Then we wait till all CPUs are done with this PMC. 2797 */ 2798 pm->pm_state = PMC_STATE_DELETED; 2799 2800 /* Wait for the PMCs runcount to come to zero. */ 2801 pmc_wait_for_pmc_idle(pm); 2802 2803 /* 2804 * At this point the PMC is off all CPUs and cannot be freshly 2805 * scheduled onto a CPU. It is now safe to unlink all targets 2806 * from this PMC. If a process-record's refcount falls to zero, 2807 * we remove it from the hash table. The module-wide SX lock 2808 * protects us from races. 2809 */ 2810 LIST_FOREACH_SAFE(ptgt, &pm->pm_targets, pt_next, tmp) { 2811 pp = ptgt->pt_process; 2812 pmc_unlink_target_process(pm, pp); /* frees 'ptgt' */ 2813 2814 PMCDBG1(PMC,REL,3, "pp->refcnt=%d", pp->pp_refcnt); 2815 2816 /* 2817 * If the target process record shows that no PMCs are 2818 * attached to it, reclaim its space. 2819 */ 2820 if (pp->pp_refcnt == 0) { 2821 pmc_remove_process_descriptor(pp); 2822 pmc_destroy_process_descriptor(pp); 2823 } 2824 } 2825 2826 cpu = curthread->td_oncpu; /* setup cpu for pmd_release() */ 2827 } 2828 2829 /* 2830 * Release any MD resources. 2831 */ 2832 (void)pcd->pcd_release_pmc(cpu, adjri, pm); 2833 2834 /* 2835 * Update row disposition. 2836 */ 2837 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) 2838 PMC_UNMARK_ROW_STANDALONE(ri); 2839 else 2840 PMC_UNMARK_ROW_THREAD(ri); 2841 2842 /* Unlink from the owner's list. */ 2843 if (pm->pm_owner != NULL) { 2844 LIST_REMOVE(pm, pm_next); 2845 pm->pm_owner = NULL; 2846 } 2847 } 2848 2849 /* 2850 * Register an owner and a pmc. 2851 */ 2852 static int 2853 pmc_register_owner(struct proc *p, struct pmc *pmc) 2854 { 2855 struct pmc_owner *po; 2856 2857 sx_assert(&pmc_sx, SX_XLOCKED); 2858 2859 if ((po = pmc_find_owner_descriptor(p)) == NULL) { 2860 if ((po = pmc_allocate_owner_descriptor(p)) == NULL) 2861 return (ENOMEM); 2862 } 2863 2864 KASSERT(pmc->pm_owner == NULL, 2865 ("[pmc,%d] attempting to own an initialized PMC", __LINE__)); 2866 pmc->pm_owner = po; 2867 2868 LIST_INSERT_HEAD(&po->po_pmcs, pmc, pm_next); 2869 2870 PROC_LOCK(p); 2871 p->p_flag |= P_HWPMC; 2872 PROC_UNLOCK(p); 2873 2874 if ((po->po_flags & PMC_PO_OWNS_LOGFILE) != 0) 2875 pmclog_process_pmcallocate(pmc); 2876 2877 PMCDBG2(PMC,REG,1, "register-owner pmc-owner=%p pmc=%p", 2878 po, pmc); 2879 2880 return (0); 2881 } 2882 2883 /* 2884 * Return the current row disposition: 2885 * == 0 => FREE 2886 * > 0 => PROCESS MODE 2887 * < 0 => SYSTEM MODE 2888 */ 2889 int 2890 pmc_getrowdisp(int ri) 2891 { 2892 return (pmc_pmcdisp[ri]); 2893 } 2894 2895 /* 2896 * Check if a PMC at row index 'ri' can be allocated to the current 2897 * process. 2898 * 2899 * Allocation can fail if: 2900 * - the current process is already being profiled by a PMC at index 'ri', 2901 * attached to it via OP_PMCATTACH. 2902 * - the current process has already allocated a PMC at index 'ri' 2903 * via OP_ALLOCATE. 2904 */ 2905 static bool 2906 pmc_can_allocate_rowindex(struct proc *p, unsigned int ri, int cpu) 2907 { 2908 struct pmc *pm; 2909 struct pmc_owner *po; 2910 struct pmc_process *pp; 2911 enum pmc_mode mode; 2912 2913 PMCDBG5(PMC,ALR,1, "can-allocate-rowindex proc=%p (%d, %s) ri=%d " 2914 "cpu=%d", p, p->p_pid, p->p_comm, ri, cpu); 2915 2916 /* 2917 * We shouldn't have already allocated a process-mode PMC at 2918 * row index 'ri'. 2919 * 2920 * We shouldn't have allocated a system-wide PMC on the same 2921 * CPU and same RI. 2922 */ 2923 if ((po = pmc_find_owner_descriptor(p)) != NULL) { 2924 LIST_FOREACH(pm, &po->po_pmcs, pm_next) { 2925 if (PMC_TO_ROWINDEX(pm) == ri) { 2926 mode = PMC_TO_MODE(pm); 2927 if (PMC_IS_VIRTUAL_MODE(mode)) 2928 return (false); 2929 if (PMC_IS_SYSTEM_MODE(mode) && 2930 PMC_TO_CPU(pm) == cpu) 2931 return (false); 2932 } 2933 } 2934 } 2935 2936 /* 2937 * We also shouldn't be the target of any PMC at this index 2938 * since otherwise a PMC_ATTACH to ourselves will fail. 2939 */ 2940 if ((pp = pmc_find_process_descriptor(p, 0)) != NULL) 2941 if (pp->pp_pmcs[ri].pp_pmc != NULL) 2942 return (false); 2943 2944 PMCDBG4(PMC,ALR,2, "can-allocate-rowindex proc=%p (%d, %s) ri=%d ok", 2945 p, p->p_pid, p->p_comm, ri); 2946 return (true); 2947 } 2948 2949 /* 2950 * Check if a given PMC at row index 'ri' can be currently used in 2951 * mode 'mode'. 2952 */ 2953 static bool 2954 pmc_can_allocate_row(int ri, enum pmc_mode mode) 2955 { 2956 enum pmc_disp disp; 2957 2958 sx_assert(&pmc_sx, SX_XLOCKED); 2959 2960 PMCDBG2(PMC,ALR,1, "can-allocate-row ri=%d mode=%d", ri, mode); 2961 2962 if (PMC_IS_SYSTEM_MODE(mode)) 2963 disp = PMC_DISP_STANDALONE; 2964 else 2965 disp = PMC_DISP_THREAD; 2966 2967 /* 2968 * check disposition for PMC row 'ri': 2969 * 2970 * Expected disposition Row-disposition Result 2971 * 2972 * STANDALONE STANDALONE or FREE proceed 2973 * STANDALONE THREAD fail 2974 * THREAD THREAD or FREE proceed 2975 * THREAD STANDALONE fail 2976 */ 2977 if (!PMC_ROW_DISP_IS_FREE(ri) && 2978 !(disp == PMC_DISP_THREAD && PMC_ROW_DISP_IS_THREAD(ri)) && 2979 !(disp == PMC_DISP_STANDALONE && PMC_ROW_DISP_IS_STANDALONE(ri))) 2980 return (false); 2981 2982 /* 2983 * All OK 2984 */ 2985 PMCDBG2(PMC,ALR,2, "can-allocate-row ri=%d mode=%d ok", ri, mode); 2986 return (true); 2987 } 2988 2989 /* 2990 * Find a PMC descriptor with user handle 'pmcid' for thread 'td'. 2991 */ 2992 static struct pmc * 2993 pmc_find_pmc_descriptor_in_process(struct pmc_owner *po, pmc_id_t pmcid) 2994 { 2995 struct pmc *pm; 2996 2997 KASSERT(PMC_ID_TO_ROWINDEX(pmcid) < md->pmd_npmc, 2998 ("[pmc,%d] Illegal pmc index %d (max %d)", __LINE__, 2999 PMC_ID_TO_ROWINDEX(pmcid), md->pmd_npmc)); 3000 3001 LIST_FOREACH(pm, &po->po_pmcs, pm_next) { 3002 if (pm->pm_id == pmcid) 3003 return (pm); 3004 } 3005 3006 return (NULL); 3007 } 3008 3009 static int 3010 pmc_find_pmc(pmc_id_t pmcid, struct pmc **pmc) 3011 { 3012 struct pmc *pm, *opm; 3013 struct pmc_owner *po; 3014 struct pmc_process *pp; 3015 3016 PMCDBG1(PMC,FND,1, "find-pmc id=%d", pmcid); 3017 if (PMC_ID_TO_ROWINDEX(pmcid) >= md->pmd_npmc) 3018 return (EINVAL); 3019 3020 if ((po = pmc_find_owner_descriptor(curthread->td_proc)) == NULL) { 3021 /* 3022 * In case of PMC_F_DESCENDANTS child processes we will not find 3023 * the current process in the owners hash list. Find the owner 3024 * process first and from there lookup the po. 3025 */ 3026 pp = pmc_find_process_descriptor(curthread->td_proc, 3027 PMC_FLAG_NONE); 3028 if (pp == NULL) 3029 return (ESRCH); 3030 opm = pp->pp_pmcs[PMC_ID_TO_ROWINDEX(pmcid)].pp_pmc; 3031 if (opm == NULL) 3032 return (ESRCH); 3033 if ((opm->pm_flags & 3034 (PMC_F_ATTACHED_TO_OWNER | PMC_F_DESCENDANTS)) != 3035 (PMC_F_ATTACHED_TO_OWNER | PMC_F_DESCENDANTS)) 3036 return (ESRCH); 3037 3038 po = opm->pm_owner; 3039 } 3040 3041 if ((pm = pmc_find_pmc_descriptor_in_process(po, pmcid)) == NULL) 3042 return (EINVAL); 3043 3044 PMCDBG2(PMC,FND,2, "find-pmc id=%d -> pmc=%p", pmcid, pm); 3045 3046 *pmc = pm; 3047 return (0); 3048 } 3049 3050 /* 3051 * Start a PMC. 3052 */ 3053 static int 3054 pmc_start(struct pmc *pm) 3055 { 3056 struct pmc_binding pb; 3057 struct pmc_classdep *pcd; 3058 struct pmc_owner *po; 3059 pmc_value_t v; 3060 enum pmc_mode mode; 3061 int adjri, error, cpu, ri; 3062 3063 KASSERT(pm != NULL, 3064 ("[pmc,%d] null pm", __LINE__)); 3065 3066 mode = PMC_TO_MODE(pm); 3067 ri = PMC_TO_ROWINDEX(pm); 3068 pcd = pmc_ri_to_classdep(md, ri, &adjri); 3069 3070 error = 0; 3071 po = pm->pm_owner; 3072 3073 PMCDBG3(PMC,OPS,1, "start pmc=%p mode=%d ri=%d", pm, mode, ri); 3074 3075 po = pm->pm_owner; 3076 3077 /* 3078 * Disallow PMCSTART if a logfile is required but has not been 3079 * configured yet. 3080 */ 3081 if ((pm->pm_flags & PMC_F_NEEDS_LOGFILE) != 0 && 3082 (po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) 3083 return (EDOOFUS); /* programming error */ 3084 3085 /* 3086 * If this is a sampling mode PMC, log mapping information for 3087 * the kernel modules that are currently loaded. 3088 */ 3089 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 3090 pmc_log_kernel_mappings(pm); 3091 3092 if (PMC_IS_VIRTUAL_MODE(mode)) { 3093 /* 3094 * If a PMCATTACH has never been done on this PMC, 3095 * attach it to its owner process. 3096 */ 3097 if (LIST_EMPTY(&pm->pm_targets)) { 3098 error = (pm->pm_flags & PMC_F_ATTACH_DONE) != 0 ? 3099 ESRCH : pmc_attach_process(po->po_owner, pm); 3100 } 3101 3102 /* 3103 * If the PMC is attached to its owner, then force a context 3104 * switch to ensure that the MD state gets set correctly. 3105 */ 3106 if (error == 0) { 3107 pm->pm_state = PMC_STATE_RUNNING; 3108 if ((pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) != 0) 3109 pmc_force_context_switch(); 3110 } 3111 3112 return (error); 3113 } 3114 3115 /* 3116 * A system-wide PMC. 3117 * 3118 * Add the owner to the global list if this is a system-wide 3119 * sampling PMC. 3120 */ 3121 if (mode == PMC_MODE_SS) { 3122 /* 3123 * Log mapping information for all existing processes in the 3124 * system. Subsequent mappings are logged as they happen; 3125 * see pmc_process_mmap(). 3126 */ 3127 if (po->po_logprocmaps == 0) { 3128 pmc_log_all_process_mappings(po); 3129 po->po_logprocmaps = 1; 3130 } 3131 po->po_sscount++; 3132 if (po->po_sscount == 1) { 3133 atomic_add_rel_int(&pmc_ss_count, 1); 3134 CK_LIST_INSERT_HEAD(&pmc_ss_owners, po, po_ssnext); 3135 PMCDBG1(PMC,OPS,1, "po=%p in global list", po); 3136 } 3137 } 3138 3139 /* 3140 * Move to the CPU associated with this 3141 * PMC, and start the hardware. 3142 */ 3143 pmc_save_cpu_binding(&pb); 3144 cpu = PMC_TO_CPU(pm); 3145 if (!pmc_cpu_is_active(cpu)) 3146 return (ENXIO); 3147 pmc_select_cpu(cpu); 3148 3149 /* 3150 * global PMCs are configured at allocation time 3151 * so write out the initial value and start the PMC. 3152 */ 3153 pm->pm_state = PMC_STATE_RUNNING; 3154 3155 critical_enter(); 3156 v = PMC_IS_SAMPLING_MODE(mode) ? pm->pm_sc.pm_reloadcount : 3157 pm->pm_sc.pm_initial; 3158 if ((error = pcd->pcd_write_pmc(cpu, adjri, pm, v)) == 0) { 3159 /* If a sampling mode PMC, reset stalled state. */ 3160 if (PMC_IS_SAMPLING_MODE(mode)) 3161 pm->pm_pcpu_state[cpu].pps_stalled = 0; 3162 3163 /* Indicate that we desire this to run. Start it. */ 3164 pm->pm_pcpu_state[cpu].pps_cpustate = 1; 3165 error = pcd->pcd_start_pmc(cpu, adjri, pm); 3166 } 3167 critical_exit(); 3168 3169 pmc_restore_cpu_binding(&pb); 3170 return (error); 3171 } 3172 3173 /* 3174 * Stop a PMC. 3175 */ 3176 static int 3177 pmc_stop(struct pmc *pm) 3178 { 3179 struct pmc_binding pb; 3180 struct pmc_classdep *pcd; 3181 struct pmc_owner *po; 3182 int adjri, cpu, error, ri; 3183 3184 KASSERT(pm != NULL, ("[pmc,%d] null pmc", __LINE__)); 3185 3186 PMCDBG3(PMC,OPS,1, "stop pmc=%p mode=%d ri=%d", pm, PMC_TO_MODE(pm), 3187 PMC_TO_ROWINDEX(pm)); 3188 3189 pm->pm_state = PMC_STATE_STOPPED; 3190 3191 /* 3192 * If the PMC is a virtual mode one, changing the state to non-RUNNING 3193 * is enough to ensure that the PMC never gets scheduled. 3194 * 3195 * If this PMC is current running on a CPU, then it will handled 3196 * correctly at the time its target process is context switched out. 3197 */ 3198 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) 3199 return (0); 3200 3201 /* 3202 * A system-mode PMC. Move to the CPU associated with this PMC, and 3203 * stop the hardware. We update the 'initial count' so that a 3204 * subsequent PMCSTART will resume counting from the current hardware 3205 * count. 3206 */ 3207 pmc_save_cpu_binding(&pb); 3208 3209 cpu = PMC_TO_CPU(pm); 3210 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 3211 ("[pmc,%d] illegal cpu=%d", __LINE__, cpu)); 3212 if (!pmc_cpu_is_active(cpu)) 3213 return (ENXIO); 3214 3215 pmc_select_cpu(cpu); 3216 3217 ri = PMC_TO_ROWINDEX(pm); 3218 pcd = pmc_ri_to_classdep(md, ri, &adjri); 3219 3220 pm->pm_pcpu_state[cpu].pps_cpustate = 0; 3221 critical_enter(); 3222 if ((error = pcd->pcd_stop_pmc(cpu, adjri, pm)) == 0) { 3223 error = pcd->pcd_read_pmc(cpu, adjri, pm, 3224 &pm->pm_sc.pm_initial); 3225 } 3226 critical_exit(); 3227 3228 pmc_restore_cpu_binding(&pb); 3229 3230 /* Remove this owner from the global list of SS PMC owners. */ 3231 po = pm->pm_owner; 3232 if (PMC_TO_MODE(pm) == PMC_MODE_SS) { 3233 po->po_sscount--; 3234 if (po->po_sscount == 0) { 3235 atomic_subtract_rel_int(&pmc_ss_count, 1); 3236 CK_LIST_REMOVE(po, po_ssnext); 3237 epoch_wait_preempt(global_epoch_preempt); 3238 PMCDBG1(PMC,OPS,2,"po=%p removed from global list", po); 3239 } 3240 } 3241 3242 return (error); 3243 } 3244 3245 static struct pmc_classdep * 3246 pmc_class_to_classdep(enum pmc_class class) 3247 { 3248 int n; 3249 3250 for (n = 0; n < md->pmd_nclass; n++) { 3251 if (md->pmd_classdep[n].pcd_class == class) 3252 return (&md->pmd_classdep[n]); 3253 } 3254 return (NULL); 3255 } 3256 3257 #if defined(HWPMC_DEBUG) && defined(KTR) 3258 static const char *pmc_op_to_name[] = { 3259 #undef __PMC_OP 3260 #define __PMC_OP(N, D) #N , 3261 __PMC_OPS() 3262 NULL 3263 }; 3264 #endif 3265 3266 /* 3267 * The syscall interface 3268 */ 3269 3270 #define PMC_GET_SX_XLOCK(...) do { \ 3271 sx_xlock(&pmc_sx); \ 3272 if (pmc_hook == NULL) { \ 3273 sx_xunlock(&pmc_sx); \ 3274 return __VA_ARGS__; \ 3275 } \ 3276 } while (0) 3277 3278 #define PMC_DOWNGRADE_SX() do { \ 3279 sx_downgrade(&pmc_sx); \ 3280 is_sx_downgraded = true; \ 3281 } while (0) 3282 3283 /* 3284 * Main body of PMC_OP_PMCALLOCATE. 3285 */ 3286 static int 3287 pmc_do_op_pmcallocate(struct thread *td, struct pmc_op_pmcallocate *pa) 3288 { 3289 struct proc *p; 3290 struct pmc *pmc; 3291 struct pmc_binding pb; 3292 struct pmc_classdep *pcd; 3293 struct pmc_hw *phw; 3294 enum pmc_mode mode; 3295 enum pmc_class class; 3296 uint32_t caps, flags; 3297 u_int cpu; 3298 int adjri, n; 3299 int error; 3300 3301 class = pa->pm_class; 3302 caps = pa->pm_caps; 3303 flags = pa->pm_flags; 3304 mode = pa->pm_mode; 3305 cpu = pa->pm_cpu; 3306 3307 p = td->td_proc; 3308 3309 /* Requested mode must exist. */ 3310 if ((mode != PMC_MODE_SS && mode != PMC_MODE_SC && 3311 mode != PMC_MODE_TS && mode != PMC_MODE_TC)) 3312 return (EINVAL); 3313 3314 /* Requested CPU must be valid. */ 3315 if (cpu != PMC_CPU_ANY && cpu >= pmc_cpu_max()) 3316 return (EINVAL); 3317 3318 /* 3319 * Virtual PMCs should only ask for a default CPU. 3320 * System mode PMCs need to specify a non-default CPU. 3321 */ 3322 if ((PMC_IS_VIRTUAL_MODE(mode) && cpu != PMC_CPU_ANY) || 3323 (PMC_IS_SYSTEM_MODE(mode) && cpu == PMC_CPU_ANY)) 3324 return (EINVAL); 3325 3326 /* 3327 * Check that an inactive CPU is not being asked for. 3328 */ 3329 if (PMC_IS_SYSTEM_MODE(mode) && !pmc_cpu_is_active(cpu)) 3330 return (ENXIO); 3331 3332 /* 3333 * Refuse an allocation for a system-wide PMC if this process has been 3334 * jailed, or if this process lacks super-user credentials and the 3335 * sysctl tunable 'security.bsd.unprivileged_syspmcs' is zero. 3336 */ 3337 if (PMC_IS_SYSTEM_MODE(mode)) { 3338 if (jailed(td->td_ucred)) 3339 return (EPERM); 3340 if (!pmc_unprivileged_syspmcs) { 3341 error = priv_check(td, PRIV_PMC_SYSTEM); 3342 if (error != 0) 3343 return (error); 3344 } 3345 } 3346 3347 /* 3348 * Look for valid values for 'pm_flags'. 3349 */ 3350 if ((flags & ~(PMC_F_DESCENDANTS | PMC_F_LOG_PROCCSW | 3351 PMC_F_LOG_PROCEXIT | PMC_F_CALLCHAIN | PMC_F_USERCALLCHAIN | 3352 PMC_F_EV_PMU)) != 0) 3353 return (EINVAL); 3354 3355 /* PMC_F_USERCALLCHAIN is only valid with PMC_F_CALLCHAIN. */ 3356 if ((flags & (PMC_F_CALLCHAIN | PMC_F_USERCALLCHAIN)) == 3357 PMC_F_USERCALLCHAIN) 3358 return (EINVAL); 3359 3360 /* PMC_F_USERCALLCHAIN is only valid for sampling mode. */ 3361 if ((flags & PMC_F_USERCALLCHAIN) != 0 && mode != PMC_MODE_TS && 3362 mode != PMC_MODE_SS) 3363 return (EINVAL); 3364 3365 /* Process logging options are not allowed for system PMCs. */ 3366 if (PMC_IS_SYSTEM_MODE(mode) && 3367 (flags & (PMC_F_LOG_PROCCSW | PMC_F_LOG_PROCEXIT)) != 0) 3368 return (EINVAL); 3369 3370 /* 3371 * All sampling mode PMCs need to be able to interrupt the CPU. 3372 */ 3373 if (PMC_IS_SAMPLING_MODE(mode)) 3374 caps |= PMC_CAP_INTERRUPT; 3375 3376 /* A valid class specifier should have been passed in. */ 3377 pcd = pmc_class_to_classdep(class); 3378 if (pcd == NULL) 3379 return (EINVAL); 3380 3381 /* The requested PMC capabilities should be feasible. */ 3382 if ((pcd->pcd_caps & caps) != caps) 3383 return (EOPNOTSUPP); 3384 3385 PMCDBG4(PMC,ALL,2, "event=%d caps=0x%x mode=%d cpu=%d", pa->pm_ev, 3386 caps, mode, cpu); 3387 3388 pmc = pmc_allocate_pmc_descriptor(); 3389 pmc->pm_id = PMC_ID_MAKE_ID(cpu, pa->pm_mode, class, PMC_ID_INVALID); 3390 pmc->pm_event = pa->pm_ev; 3391 pmc->pm_state = PMC_STATE_FREE; 3392 pmc->pm_caps = caps; 3393 pmc->pm_flags = flags; 3394 3395 /* XXX set lower bound on sampling for process counters */ 3396 if (PMC_IS_SAMPLING_MODE(mode)) { 3397 /* 3398 * Don't permit requested sample rate to be less than 3399 * pmc_mincount. 3400 */ 3401 if (pa->pm_count < MAX(1, pmc_mincount)) 3402 log(LOG_WARNING, "pmcallocate: passed sample " 3403 "rate %ju - setting to %u\n", 3404 (uintmax_t)pa->pm_count, 3405 MAX(1, pmc_mincount)); 3406 pmc->pm_sc.pm_reloadcount = MAX(MAX(1, pmc_mincount), 3407 pa->pm_count); 3408 } else 3409 pmc->pm_sc.pm_initial = pa->pm_count; 3410 3411 /* switch thread to CPU 'cpu' */ 3412 pmc_save_cpu_binding(&pb); 3413 3414 #define PMC_IS_SHAREABLE_PMC(cpu, n) \ 3415 (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_state & \ 3416 PMC_PHW_FLAG_IS_SHAREABLE) 3417 #define PMC_IS_UNALLOCATED(cpu, n) \ 3418 (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_pmc == NULL) 3419 3420 if (PMC_IS_SYSTEM_MODE(mode)) { 3421 pmc_select_cpu(cpu); 3422 for (n = pcd->pcd_ri; n < md->pmd_npmc; n++) { 3423 pcd = pmc_ri_to_classdep(md, n, &adjri); 3424 3425 if (!pmc_can_allocate_row(n, mode) || 3426 !pmc_can_allocate_rowindex(p, n, cpu)) 3427 continue; 3428 if (!PMC_IS_UNALLOCATED(cpu, n) && 3429 !PMC_IS_SHAREABLE_PMC(cpu, n)) 3430 continue; 3431 3432 if (pcd->pcd_allocate_pmc(cpu, adjri, pmc, pa) == 0) { 3433 /* Success. */ 3434 break; 3435 } 3436 } 3437 } else { 3438 /* Process virtual mode */ 3439 for (n = pcd->pcd_ri; n < md->pmd_npmc; n++) { 3440 pcd = pmc_ri_to_classdep(md, n, &adjri); 3441 3442 if (!pmc_can_allocate_row(n, mode) || 3443 !pmc_can_allocate_rowindex(p, n, PMC_CPU_ANY)) 3444 continue; 3445 3446 if (pcd->pcd_allocate_pmc(td->td_oncpu, adjri, pmc, 3447 pa) == 0) { 3448 /* Success. */ 3449 break; 3450 } 3451 } 3452 } 3453 3454 #undef PMC_IS_UNALLOCATED 3455 #undef PMC_IS_SHAREABLE_PMC 3456 3457 pmc_restore_cpu_binding(&pb); 3458 3459 if (n == md->pmd_npmc) { 3460 pmc_destroy_pmc_descriptor(pmc); 3461 return (EINVAL); 3462 } 3463 3464 /* Fill in the correct value in the ID field. */ 3465 pmc->pm_id = PMC_ID_MAKE_ID(cpu, mode, class, n); 3466 3467 PMCDBG5(PMC,ALL,2, "ev=%d class=%d mode=%d n=%d -> pmcid=%x", 3468 pmc->pm_event, class, mode, n, pmc->pm_id); 3469 3470 /* Process mode PMCs with logging enabled need log files. */ 3471 if ((pmc->pm_flags & (PMC_F_LOG_PROCEXIT | PMC_F_LOG_PROCCSW)) != 0) 3472 pmc->pm_flags |= PMC_F_NEEDS_LOGFILE; 3473 3474 /* All system mode sampling PMCs require a log file. */ 3475 if (PMC_IS_SAMPLING_MODE(mode) && PMC_IS_SYSTEM_MODE(mode)) 3476 pmc->pm_flags |= PMC_F_NEEDS_LOGFILE; 3477 3478 /* 3479 * Configure global pmc's immediately. 3480 */ 3481 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pmc))) { 3482 pmc_save_cpu_binding(&pb); 3483 pmc_select_cpu(cpu); 3484 3485 phw = pmc_pcpu[cpu]->pc_hwpmcs[n]; 3486 pcd = pmc_ri_to_classdep(md, n, &adjri); 3487 3488 if ((phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0 || 3489 (error = pcd->pcd_config_pmc(cpu, adjri, pmc)) != 0) { 3490 (void)pcd->pcd_release_pmc(cpu, adjri, pmc); 3491 pmc_destroy_pmc_descriptor(pmc); 3492 pmc_restore_cpu_binding(&pb); 3493 return (EPERM); 3494 } 3495 3496 pmc_restore_cpu_binding(&pb); 3497 } 3498 3499 pmc->pm_state = PMC_STATE_ALLOCATED; 3500 pmc->pm_class = class; 3501 3502 /* 3503 * Mark row disposition. 3504 */ 3505 if (PMC_IS_SYSTEM_MODE(mode)) 3506 PMC_MARK_ROW_STANDALONE(n); 3507 else 3508 PMC_MARK_ROW_THREAD(n); 3509 3510 /* 3511 * Register this PMC with the current thread as its owner. 3512 */ 3513 error = pmc_register_owner(p, pmc); 3514 if (error != 0) { 3515 pmc_release_pmc_descriptor(pmc); 3516 pmc_destroy_pmc_descriptor(pmc); 3517 return (error); 3518 } 3519 3520 /* 3521 * Return the allocated index. 3522 */ 3523 pa->pm_pmcid = pmc->pm_id; 3524 return (0); 3525 } 3526 3527 /* 3528 * Main body of PMC_OP_PMCATTACH. 3529 */ 3530 static int 3531 pmc_do_op_pmcattach(struct thread *td, struct pmc_op_pmcattach a) 3532 { 3533 struct pmc *pm; 3534 struct proc *p; 3535 int error; 3536 3537 sx_assert(&pmc_sx, SX_XLOCKED); 3538 3539 if (a.pm_pid < 0) { 3540 return (EINVAL); 3541 } else if (a.pm_pid == 0) { 3542 a.pm_pid = td->td_proc->p_pid; 3543 } 3544 3545 error = pmc_find_pmc(a.pm_pmc, &pm); 3546 if (error != 0) 3547 return (error); 3548 3549 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) 3550 return (EINVAL); 3551 3552 /* PMCs may be (re)attached only when allocated or stopped */ 3553 if (pm->pm_state == PMC_STATE_RUNNING) { 3554 return (EBUSY); 3555 } else if (pm->pm_state != PMC_STATE_ALLOCATED && 3556 pm->pm_state != PMC_STATE_STOPPED) { 3557 return (EINVAL); 3558 } 3559 3560 /* lookup pid */ 3561 if ((p = pfind(a.pm_pid)) == NULL) 3562 return (ESRCH); 3563 3564 /* 3565 * Ignore processes that are working on exiting. 3566 */ 3567 if ((p->p_flag & P_WEXIT) != 0) { 3568 PROC_UNLOCK(p); /* pfind() returns a locked process */ 3569 return (ESRCH); 3570 } 3571 3572 /* 3573 * We are allowed to attach a PMC to a process if we can debug it. 3574 */ 3575 error = p_candebug(curthread, p); 3576 3577 PROC_UNLOCK(p); 3578 3579 if (error == 0) 3580 error = pmc_attach_process(p, pm); 3581 3582 return (error); 3583 } 3584 3585 /* 3586 * Main body of PMC_OP_PMCDETACH. 3587 */ 3588 static int 3589 pmc_do_op_pmcdetach(struct thread *td, struct pmc_op_pmcattach a) 3590 { 3591 struct pmc *pm; 3592 struct proc *p; 3593 int error; 3594 3595 if (a.pm_pid < 0) { 3596 return (EINVAL); 3597 } else if (a.pm_pid == 0) 3598 a.pm_pid = td->td_proc->p_pid; 3599 3600 error = pmc_find_pmc(a.pm_pmc, &pm); 3601 if (error != 0) 3602 return (error); 3603 3604 if ((p = pfind(a.pm_pid)) == NULL) 3605 return (ESRCH); 3606 3607 /* 3608 * Treat processes that are in the process of exiting as if they were 3609 * not present. 3610 */ 3611 if ((p->p_flag & P_WEXIT) != 0) { 3612 PROC_UNLOCK(p); 3613 return (ESRCH); 3614 } 3615 3616 PROC_UNLOCK(p); /* pfind() returns a locked process */ 3617 3618 if (error == 0) 3619 error = pmc_detach_process(p, pm); 3620 3621 return (error); 3622 } 3623 3624 /* 3625 * Main body of PMC_OP_PMCRELEASE. 3626 */ 3627 static int 3628 pmc_do_op_pmcrelease(pmc_id_t pmcid) 3629 { 3630 struct pmc_owner *po; 3631 struct pmc *pm; 3632 int error; 3633 3634 /* 3635 * Find PMC pointer for the named PMC. 3636 * 3637 * Use pmc_release_pmc_descriptor() to switch off the 3638 * PMC, remove all its target threads, and remove the 3639 * PMC from its owner's list. 3640 * 3641 * Remove the owner record if this is the last PMC 3642 * owned. 3643 * 3644 * Free up space. 3645 */ 3646 error = pmc_find_pmc(pmcid, &pm); 3647 if (error != 0) 3648 return (error); 3649 3650 po = pm->pm_owner; 3651 pmc_release_pmc_descriptor(pm); 3652 pmc_maybe_remove_owner(po); 3653 pmc_destroy_pmc_descriptor(pm); 3654 3655 return (error); 3656 } 3657 3658 /* 3659 * Main body of PMC_OP_PMCRW. 3660 */ 3661 static int 3662 pmc_do_op_pmcrw(const struct pmc_op_pmcrw *prw, pmc_value_t *valp) 3663 { 3664 struct pmc_binding pb; 3665 struct pmc_classdep *pcd; 3666 struct pmc *pm; 3667 u_int cpu, ri, adjri; 3668 int error; 3669 3670 PMCDBG2(PMC,OPS,1, "rw id=%d flags=0x%x", prw->pm_pmcid, prw->pm_flags); 3671 3672 /* Must have at least one flag set. */ 3673 if ((prw->pm_flags & (PMC_F_OLDVALUE | PMC_F_NEWVALUE)) == 0) 3674 return (EINVAL); 3675 3676 /* Locate PMC descriptor. */ 3677 error = pmc_find_pmc(prw->pm_pmcid, &pm); 3678 if (error != 0) 3679 return (error); 3680 3681 /* Can't read a PMC that hasn't been started. */ 3682 if (pm->pm_state != PMC_STATE_ALLOCATED && 3683 pm->pm_state != PMC_STATE_STOPPED && 3684 pm->pm_state != PMC_STATE_RUNNING) 3685 return (EINVAL); 3686 3687 /* Writing a new value is allowed only for 'STOPPED' PMCs. */ 3688 if (pm->pm_state == PMC_STATE_RUNNING && 3689 (prw->pm_flags & PMC_F_NEWVALUE) != 0) 3690 return (EBUSY); 3691 3692 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) { 3693 /* 3694 * If this PMC is attached to its owner (i.e., the process 3695 * requesting this operation) and is running, then attempt to 3696 * get an upto-date reading from hardware for a READ. Writes 3697 * are only allowed when the PMC is stopped, so only update the 3698 * saved value field. 3699 * 3700 * If the PMC is not running, or is not attached to its owner, 3701 * read/write to the savedvalue field. 3702 */ 3703 3704 ri = PMC_TO_ROWINDEX(pm); 3705 pcd = pmc_ri_to_classdep(md, ri, &adjri); 3706 3707 mtx_pool_lock_spin(pmc_mtxpool, pm); 3708 cpu = curthread->td_oncpu; 3709 3710 if ((prw->pm_flags & PMC_F_OLDVALUE) != 0) { 3711 if ((pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) && 3712 (pm->pm_state == PMC_STATE_RUNNING)) { 3713 error = (*pcd->pcd_read_pmc)(cpu, adjri, pm, 3714 valp); 3715 } else { 3716 *valp = pm->pm_gv.pm_savedvalue; 3717 } 3718 } 3719 3720 if ((prw->pm_flags & PMC_F_NEWVALUE) != 0) 3721 pm->pm_gv.pm_savedvalue = prw->pm_value; 3722 3723 mtx_pool_unlock_spin(pmc_mtxpool, pm); 3724 } else { /* System mode PMCs */ 3725 cpu = PMC_TO_CPU(pm); 3726 ri = PMC_TO_ROWINDEX(pm); 3727 pcd = pmc_ri_to_classdep(md, ri, &adjri); 3728 3729 if (!pmc_cpu_is_active(cpu)) 3730 return (ENXIO); 3731 3732 /* Move this thread to CPU 'cpu'. */ 3733 pmc_save_cpu_binding(&pb); 3734 pmc_select_cpu(cpu); 3735 critical_enter(); 3736 3737 /* Save old value. */ 3738 if ((prw->pm_flags & PMC_F_OLDVALUE) != 0) 3739 error = (*pcd->pcd_read_pmc)(cpu, adjri, pm, valp); 3740 3741 /* Write out new value. */ 3742 if (error == 0 && (prw->pm_flags & PMC_F_NEWVALUE) != 0) 3743 error = (*pcd->pcd_write_pmc)(cpu, adjri, pm, 3744 prw->pm_value); 3745 3746 critical_exit(); 3747 pmc_restore_cpu_binding(&pb); 3748 if (error != 0) 3749 return (error); 3750 } 3751 3752 #ifdef HWPMC_DEBUG 3753 if ((prw->pm_flags & PMC_F_NEWVALUE) != 0) 3754 PMCDBG3(PMC,OPS,2, "rw id=%d new %jx -> old %jx", 3755 ri, prw->pm_value, *valp); 3756 else 3757 PMCDBG2(PMC,OPS,2, "rw id=%d -> old %jx", ri, *valp); 3758 #endif 3759 return (error); 3760 } 3761 3762 static int 3763 pmc_syscall_handler(struct thread *td, void *syscall_args) 3764 { 3765 struct pmc_syscall_args *c; 3766 void *pmclog_proc_handle; 3767 void *arg; 3768 int error, op; 3769 bool is_sx_downgraded; 3770 3771 c = (struct pmc_syscall_args *)syscall_args; 3772 op = c->pmop_code; 3773 arg = c->pmop_data; 3774 3775 /* PMC isn't set up yet */ 3776 if (pmc_hook == NULL) 3777 return (EINVAL); 3778 3779 if (op == PMC_OP_CONFIGURELOG) { 3780 /* 3781 * We cannot create the logging process inside 3782 * pmclog_configure_log() because there is a LOR 3783 * between pmc_sx and process structure locks. 3784 * Instead, pre-create the process and ignite the loop 3785 * if everything is fine, otherwise direct the process 3786 * to exit. 3787 */ 3788 error = pmclog_proc_create(td, &pmclog_proc_handle); 3789 if (error != 0) 3790 goto done_syscall; 3791 } 3792 3793 PMC_GET_SX_XLOCK(ENOSYS); 3794 is_sx_downgraded = false; 3795 PMCDBG3(MOD,PMS,1, "syscall op=%d \"%s\" arg=%p", op, 3796 pmc_op_to_name[op], arg); 3797 3798 error = 0; 3799 counter_u64_add(pmc_stats.pm_syscalls, 1); 3800 3801 switch (op) { 3802 3803 3804 /* 3805 * Configure a log file. 3806 * 3807 * XXX This OP will be reworked. 3808 */ 3809 3810 case PMC_OP_CONFIGURELOG: 3811 { 3812 struct proc *p; 3813 struct pmc *pm; 3814 struct pmc_owner *po; 3815 struct pmc_op_configurelog cl; 3816 3817 if ((error = copyin(arg, &cl, sizeof(cl))) != 0) { 3818 pmclog_proc_ignite(pmclog_proc_handle, NULL); 3819 break; 3820 } 3821 3822 /* No flags currently implemented */ 3823 if (cl.pm_flags != 0) { 3824 pmclog_proc_ignite(pmclog_proc_handle, NULL); 3825 error = EINVAL; 3826 break; 3827 } 3828 3829 /* mark this process as owning a log file */ 3830 p = td->td_proc; 3831 if ((po = pmc_find_owner_descriptor(p)) == NULL) 3832 if ((po = pmc_allocate_owner_descriptor(p)) == NULL) { 3833 pmclog_proc_ignite(pmclog_proc_handle, NULL); 3834 error = ENOMEM; 3835 break; 3836 } 3837 3838 /* 3839 * If a valid fd was passed in, try to configure that, 3840 * otherwise if 'fd' was less than zero and there was 3841 * a log file configured, flush its buffers and 3842 * de-configure it. 3843 */ 3844 if (cl.pm_logfd >= 0) { 3845 error = pmclog_configure_log(md, po, cl.pm_logfd); 3846 pmclog_proc_ignite(pmclog_proc_handle, error == 0 ? 3847 po : NULL); 3848 } else if (po->po_flags & PMC_PO_OWNS_LOGFILE) { 3849 pmclog_proc_ignite(pmclog_proc_handle, NULL); 3850 error = pmclog_close(po); 3851 if (error == 0) { 3852 LIST_FOREACH(pm, &po->po_pmcs, pm_next) 3853 if (pm->pm_flags & PMC_F_NEEDS_LOGFILE && 3854 pm->pm_state == PMC_STATE_RUNNING) 3855 pmc_stop(pm); 3856 error = pmclog_deconfigure_log(po); 3857 } 3858 } else { 3859 pmclog_proc_ignite(pmclog_proc_handle, NULL); 3860 error = EINVAL; 3861 } 3862 } 3863 break; 3864 3865 /* 3866 * Flush a log file. 3867 */ 3868 3869 case PMC_OP_FLUSHLOG: 3870 { 3871 struct pmc_owner *po; 3872 3873 sx_assert(&pmc_sx, SX_XLOCKED); 3874 3875 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 3876 error = EINVAL; 3877 break; 3878 } 3879 3880 error = pmclog_flush(po, 0); 3881 } 3882 break; 3883 3884 /* 3885 * Close a log file. 3886 */ 3887 3888 case PMC_OP_CLOSELOG: 3889 { 3890 struct pmc_owner *po; 3891 3892 sx_assert(&pmc_sx, SX_XLOCKED); 3893 3894 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 3895 error = EINVAL; 3896 break; 3897 } 3898 3899 error = pmclog_close(po); 3900 } 3901 break; 3902 3903 /* 3904 * Retrieve hardware configuration. 3905 */ 3906 3907 case PMC_OP_GETCPUINFO: /* CPU information */ 3908 { 3909 struct pmc_op_getcpuinfo gci; 3910 struct pmc_classinfo *pci; 3911 struct pmc_classdep *pcd; 3912 int cl; 3913 3914 memset(&gci, 0, sizeof(gci)); 3915 gci.pm_cputype = md->pmd_cputype; 3916 gci.pm_ncpu = pmc_cpu_max(); 3917 gci.pm_npmc = md->pmd_npmc; 3918 gci.pm_nclass = md->pmd_nclass; 3919 pci = gci.pm_classes; 3920 pcd = md->pmd_classdep; 3921 for (cl = 0; cl < md->pmd_nclass; cl++, pci++, pcd++) { 3922 pci->pm_caps = pcd->pcd_caps; 3923 pci->pm_class = pcd->pcd_class; 3924 pci->pm_width = pcd->pcd_width; 3925 pci->pm_num = pcd->pcd_num; 3926 } 3927 error = copyout(&gci, arg, sizeof(gci)); 3928 } 3929 break; 3930 3931 /* 3932 * Retrieve soft events list. 3933 */ 3934 case PMC_OP_GETDYNEVENTINFO: 3935 { 3936 enum pmc_class cl; 3937 enum pmc_event ev; 3938 struct pmc_op_getdyneventinfo *gei; 3939 struct pmc_dyn_event_descr dev; 3940 struct pmc_soft *ps; 3941 uint32_t nevent; 3942 3943 sx_assert(&pmc_sx, SX_LOCKED); 3944 3945 gei = (struct pmc_op_getdyneventinfo *) arg; 3946 3947 if ((error = copyin(&gei->pm_class, &cl, sizeof(cl))) != 0) 3948 break; 3949 3950 /* Only SOFT class is dynamic. */ 3951 if (cl != PMC_CLASS_SOFT) { 3952 error = EINVAL; 3953 break; 3954 } 3955 3956 nevent = 0; 3957 for (ev = PMC_EV_SOFT_FIRST; (int)ev <= PMC_EV_SOFT_LAST; ev++) { 3958 ps = pmc_soft_ev_acquire(ev); 3959 if (ps == NULL) 3960 continue; 3961 bcopy(&ps->ps_ev, &dev, sizeof(dev)); 3962 pmc_soft_ev_release(ps); 3963 3964 error = copyout(&dev, 3965 &gei->pm_events[nevent], 3966 sizeof(struct pmc_dyn_event_descr)); 3967 if (error != 0) 3968 break; 3969 nevent++; 3970 } 3971 if (error != 0) 3972 break; 3973 3974 error = copyout(&nevent, &gei->pm_nevent, 3975 sizeof(nevent)); 3976 } 3977 break; 3978 3979 /* 3980 * Get module statistics 3981 */ 3982 3983 case PMC_OP_GETDRIVERSTATS: 3984 { 3985 struct pmc_op_getdriverstats gms; 3986 #define CFETCH(a, b, field) a.field = counter_u64_fetch(b.field) 3987 CFETCH(gms, pmc_stats, pm_intr_ignored); 3988 CFETCH(gms, pmc_stats, pm_intr_processed); 3989 CFETCH(gms, pmc_stats, pm_intr_bufferfull); 3990 CFETCH(gms, pmc_stats, pm_syscalls); 3991 CFETCH(gms, pmc_stats, pm_syscall_errors); 3992 CFETCH(gms, pmc_stats, pm_buffer_requests); 3993 CFETCH(gms, pmc_stats, pm_buffer_requests_failed); 3994 CFETCH(gms, pmc_stats, pm_log_sweeps); 3995 #undef CFETCH 3996 error = copyout(&gms, arg, sizeof(gms)); 3997 } 3998 break; 3999 4000 4001 /* 4002 * Retrieve module version number 4003 */ 4004 4005 case PMC_OP_GETMODULEVERSION: 4006 { 4007 uint32_t cv, modv; 4008 4009 /* retrieve the client's idea of the ABI version */ 4010 if ((error = copyin(arg, &cv, sizeof(uint32_t))) != 0) 4011 break; 4012 /* don't service clients newer than our driver */ 4013 modv = PMC_VERSION; 4014 if ((cv & 0xFFFF0000) > (modv & 0xFFFF0000)) { 4015 error = EPROGMISMATCH; 4016 break; 4017 } 4018 error = copyout(&modv, arg, sizeof(int)); 4019 } 4020 break; 4021 4022 4023 /* 4024 * Retrieve the state of all the PMCs on a given 4025 * CPU. 4026 */ 4027 4028 case PMC_OP_GETPMCINFO: 4029 { 4030 int ari; 4031 struct pmc *pm; 4032 size_t pmcinfo_size; 4033 uint32_t cpu, n, npmc; 4034 struct pmc_owner *po; 4035 struct pmc_binding pb; 4036 struct pmc_classdep *pcd; 4037 struct pmc_info *p, *pmcinfo; 4038 struct pmc_op_getpmcinfo *gpi; 4039 4040 PMC_DOWNGRADE_SX(); 4041 4042 gpi = (struct pmc_op_getpmcinfo *) arg; 4043 4044 if ((error = copyin(&gpi->pm_cpu, &cpu, sizeof(cpu))) != 0) 4045 break; 4046 4047 if (cpu >= pmc_cpu_max()) { 4048 error = EINVAL; 4049 break; 4050 } 4051 4052 if (!pmc_cpu_is_active(cpu)) { 4053 error = ENXIO; 4054 break; 4055 } 4056 4057 /* switch to CPU 'cpu' */ 4058 pmc_save_cpu_binding(&pb); 4059 pmc_select_cpu(cpu); 4060 4061 npmc = md->pmd_npmc; 4062 4063 pmcinfo_size = npmc * sizeof(struct pmc_info); 4064 pmcinfo = malloc(pmcinfo_size, M_PMC, M_WAITOK | M_ZERO); 4065 4066 p = pmcinfo; 4067 4068 for (n = 0; n < md->pmd_npmc; n++, p++) { 4069 4070 pcd = pmc_ri_to_classdep(md, n, &ari); 4071 4072 KASSERT(pcd != NULL, 4073 ("[pmc,%d] null pcd ri=%d", __LINE__, n)); 4074 4075 if ((error = pcd->pcd_describe(cpu, ari, p, &pm)) != 0) 4076 break; 4077 4078 if (PMC_ROW_DISP_IS_STANDALONE(n)) 4079 p->pm_rowdisp = PMC_DISP_STANDALONE; 4080 else if (PMC_ROW_DISP_IS_THREAD(n)) 4081 p->pm_rowdisp = PMC_DISP_THREAD; 4082 else 4083 p->pm_rowdisp = PMC_DISP_FREE; 4084 4085 p->pm_ownerpid = -1; 4086 4087 if (pm == NULL) /* no PMC associated */ 4088 continue; 4089 4090 po = pm->pm_owner; 4091 4092 KASSERT(po->po_owner != NULL, 4093 ("[pmc,%d] pmc_owner had a null proc pointer", 4094 __LINE__)); 4095 4096 p->pm_ownerpid = po->po_owner->p_pid; 4097 p->pm_mode = PMC_TO_MODE(pm); 4098 p->pm_event = pm->pm_event; 4099 p->pm_flags = pm->pm_flags; 4100 4101 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 4102 p->pm_reloadcount = 4103 pm->pm_sc.pm_reloadcount; 4104 } 4105 4106 pmc_restore_cpu_binding(&pb); 4107 4108 /* now copy out the PMC info collected */ 4109 if (error == 0) 4110 error = copyout(pmcinfo, &gpi->pm_pmcs, pmcinfo_size); 4111 4112 free(pmcinfo, M_PMC); 4113 } 4114 break; 4115 4116 4117 /* 4118 * Set the administrative state of a PMC. I.e. whether 4119 * the PMC is to be used or not. 4120 */ 4121 4122 case PMC_OP_PMCADMIN: 4123 { 4124 int cpu, ri; 4125 enum pmc_state request; 4126 struct pmc_cpu *pc; 4127 struct pmc_hw *phw; 4128 struct pmc_op_pmcadmin pma; 4129 struct pmc_binding pb; 4130 4131 sx_assert(&pmc_sx, SX_XLOCKED); 4132 4133 KASSERT(td == curthread, 4134 ("[pmc,%d] td != curthread", __LINE__)); 4135 4136 error = priv_check(td, PRIV_PMC_MANAGE); 4137 if (error) 4138 break; 4139 4140 if ((error = copyin(arg, &pma, sizeof(pma))) != 0) 4141 break; 4142 4143 cpu = pma.pm_cpu; 4144 4145 if (cpu < 0 || cpu >= (int) pmc_cpu_max()) { 4146 error = EINVAL; 4147 break; 4148 } 4149 4150 if (!pmc_cpu_is_active(cpu)) { 4151 error = ENXIO; 4152 break; 4153 } 4154 4155 request = pma.pm_state; 4156 4157 if (request != PMC_STATE_DISABLED && 4158 request != PMC_STATE_FREE) { 4159 error = EINVAL; 4160 break; 4161 } 4162 4163 ri = pma.pm_pmc; /* pmc id == row index */ 4164 if (ri < 0 || ri >= (int) md->pmd_npmc) { 4165 error = EINVAL; 4166 break; 4167 } 4168 4169 /* 4170 * We can't disable a PMC with a row-index allocated 4171 * for process virtual PMCs. 4172 */ 4173 4174 if (PMC_ROW_DISP_IS_THREAD(ri) && 4175 request == PMC_STATE_DISABLED) { 4176 error = EBUSY; 4177 break; 4178 } 4179 4180 /* 4181 * otherwise, this PMC on this CPU is either free or 4182 * in system-wide mode. 4183 */ 4184 4185 pmc_save_cpu_binding(&pb); 4186 pmc_select_cpu(cpu); 4187 4188 pc = pmc_pcpu[cpu]; 4189 phw = pc->pc_hwpmcs[ri]; 4190 4191 /* 4192 * XXX do we need some kind of 'forced' disable? 4193 */ 4194 4195 if (phw->phw_pmc == NULL) { 4196 if (request == PMC_STATE_DISABLED && 4197 (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED)) { 4198 phw->phw_state &= ~PMC_PHW_FLAG_IS_ENABLED; 4199 PMC_MARK_ROW_STANDALONE(ri); 4200 } else if (request == PMC_STATE_FREE && 4201 (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0) { 4202 phw->phw_state |= PMC_PHW_FLAG_IS_ENABLED; 4203 PMC_UNMARK_ROW_STANDALONE(ri); 4204 } 4205 /* other cases are a no-op */ 4206 } else 4207 error = EBUSY; 4208 4209 pmc_restore_cpu_binding(&pb); 4210 } 4211 break; 4212 4213 4214 /* 4215 * Allocate a PMC. 4216 */ 4217 case PMC_OP_PMCALLOCATE: 4218 { 4219 struct pmc_op_pmcallocate pa; 4220 4221 error = copyin(arg, &pa, sizeof(pa)); 4222 if (error != 0) 4223 break; 4224 4225 error = pmc_do_op_pmcallocate(td, &pa); 4226 if (error != 0) 4227 break; 4228 4229 error = copyout(&pa, arg, sizeof(pa)); 4230 } 4231 break; 4232 4233 /* 4234 * Attach a PMC to a process. 4235 */ 4236 case PMC_OP_PMCATTACH: 4237 { 4238 struct pmc_op_pmcattach a; 4239 4240 error = copyin(arg, &a, sizeof(a)); 4241 if (error != 0) 4242 break; 4243 4244 error = pmc_do_op_pmcattach(td, a); 4245 } 4246 break; 4247 4248 /* 4249 * Detach an attached PMC from a process. 4250 */ 4251 case PMC_OP_PMCDETACH: 4252 { 4253 struct pmc_op_pmcattach a; 4254 4255 error = copyin(arg, &a, sizeof(a)); 4256 if (error != 0) 4257 break; 4258 4259 error = pmc_do_op_pmcdetach(td, a); 4260 } 4261 break; 4262 4263 4264 /* 4265 * Retrieve the MSR number associated with the counter 4266 * 'pmc_id'. This allows processes to directly use RDPMC 4267 * instructions to read their PMCs, without the overhead of a 4268 * system call. 4269 */ 4270 4271 case PMC_OP_PMCGETMSR: 4272 { 4273 int adjri, ri; 4274 struct pmc *pm; 4275 struct pmc_target *pt; 4276 struct pmc_op_getmsr gm; 4277 struct pmc_classdep *pcd; 4278 4279 PMC_DOWNGRADE_SX(); 4280 4281 if ((error = copyin(arg, &gm, sizeof(gm))) != 0) 4282 break; 4283 4284 if ((error = pmc_find_pmc(gm.pm_pmcid, &pm)) != 0) 4285 break; 4286 4287 /* 4288 * The allocated PMC has to be a process virtual PMC, 4289 * i.e., of type MODE_T[CS]. Global PMCs can only be 4290 * read using the PMCREAD operation since they may be 4291 * allocated on a different CPU than the one we could 4292 * be running on at the time of the RDPMC instruction. 4293 * 4294 * The GETMSR operation is not allowed for PMCs that 4295 * are inherited across processes. 4296 */ 4297 4298 if (!PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)) || 4299 (pm->pm_flags & PMC_F_DESCENDANTS)) { 4300 error = EINVAL; 4301 break; 4302 } 4303 4304 /* 4305 * It only makes sense to use a RDPMC (or its 4306 * equivalent instruction on non-x86 architectures) on 4307 * a process that has allocated and attached a PMC to 4308 * itself. Conversely the PMC is only allowed to have 4309 * one process attached to it -- its owner. 4310 */ 4311 4312 if ((pt = LIST_FIRST(&pm->pm_targets)) == NULL || 4313 LIST_NEXT(pt, pt_next) != NULL || 4314 pt->pt_process->pp_proc != pm->pm_owner->po_owner) { 4315 error = EINVAL; 4316 break; 4317 } 4318 4319 ri = PMC_TO_ROWINDEX(pm); 4320 pcd = pmc_ri_to_classdep(md, ri, &adjri); 4321 4322 /* PMC class has no 'GETMSR' support */ 4323 if (pcd->pcd_get_msr == NULL) { 4324 error = ENOSYS; 4325 break; 4326 } 4327 4328 if ((error = (*pcd->pcd_get_msr)(adjri, &gm.pm_msr)) < 0) 4329 break; 4330 4331 if ((error = copyout(&gm, arg, sizeof(gm))) < 0) 4332 break; 4333 4334 /* 4335 * Mark our process as using MSRs. Update machine 4336 * state using a forced context switch. 4337 */ 4338 4339 pt->pt_process->pp_flags |= PMC_PP_ENABLE_MSR_ACCESS; 4340 pmc_force_context_switch(); 4341 4342 } 4343 break; 4344 4345 /* 4346 * Release an allocated PMC. 4347 */ 4348 case PMC_OP_PMCRELEASE: 4349 { 4350 struct pmc_op_simple sp; 4351 4352 error = copyin(arg, &sp, sizeof(sp)); 4353 if (error != 0) 4354 break; 4355 4356 error = pmc_do_op_pmcrelease(sp.pm_pmcid); 4357 } 4358 break; 4359 4360 /* 4361 * Read and/or write a PMC. 4362 */ 4363 case PMC_OP_PMCRW: 4364 { 4365 struct pmc_op_pmcrw prw; 4366 struct pmc_op_pmcrw *pprw; 4367 pmc_value_t oldvalue; 4368 4369 PMC_DOWNGRADE_SX(); 4370 4371 error = copyin(arg, &prw, sizeof(prw)); 4372 if (error != 0) 4373 break; 4374 4375 error = pmc_do_op_pmcrw(&prw, &oldvalue); 4376 if (error != 0) 4377 break; 4378 4379 /* Return old value if requested. */ 4380 if ((prw.pm_flags & PMC_F_OLDVALUE) != 0) { 4381 pprw = arg; 4382 error = copyout(&oldvalue, &pprw->pm_value, 4383 sizeof(prw.pm_value)); 4384 } 4385 } 4386 break; 4387 4388 4389 /* 4390 * Set the sampling rate for a sampling mode PMC and the 4391 * initial count for a counting mode PMC. 4392 */ 4393 4394 case PMC_OP_PMCSETCOUNT: 4395 { 4396 struct pmc *pm; 4397 struct pmc_op_pmcsetcount sc; 4398 4399 PMC_DOWNGRADE_SX(); 4400 4401 if ((error = copyin(arg, &sc, sizeof(sc))) != 0) 4402 break; 4403 4404 if ((error = pmc_find_pmc(sc.pm_pmcid, &pm)) != 0) 4405 break; 4406 4407 if (pm->pm_state == PMC_STATE_RUNNING) { 4408 error = EBUSY; 4409 break; 4410 } 4411 4412 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) { 4413 /* 4414 * Don't permit requested sample rate to be 4415 * less than pmc_mincount. 4416 */ 4417 if (sc.pm_count < MAX(1, pmc_mincount)) 4418 log(LOG_WARNING, "pmcsetcount: passed sample " 4419 "rate %ju - setting to %u\n", 4420 (uintmax_t)sc.pm_count, 4421 MAX(1, pmc_mincount)); 4422 pm->pm_sc.pm_reloadcount = MAX(MAX(1, pmc_mincount), 4423 sc.pm_count); 4424 } else 4425 pm->pm_sc.pm_initial = sc.pm_count; 4426 } 4427 break; 4428 4429 4430 /* 4431 * Start a PMC. 4432 */ 4433 4434 case PMC_OP_PMCSTART: 4435 { 4436 pmc_id_t pmcid; 4437 struct pmc *pm; 4438 struct pmc_op_simple sp; 4439 4440 sx_assert(&pmc_sx, SX_XLOCKED); 4441 4442 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 4443 break; 4444 4445 pmcid = sp.pm_pmcid; 4446 4447 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 4448 break; 4449 4450 KASSERT(pmcid == pm->pm_id, 4451 ("[pmc,%d] pmcid %x != id %x", __LINE__, 4452 pm->pm_id, pmcid)); 4453 4454 if (pm->pm_state == PMC_STATE_RUNNING) /* already running */ 4455 break; 4456 else if (pm->pm_state != PMC_STATE_STOPPED && 4457 pm->pm_state != PMC_STATE_ALLOCATED) { 4458 error = EINVAL; 4459 break; 4460 } 4461 4462 error = pmc_start(pm); 4463 } 4464 break; 4465 4466 4467 /* 4468 * Stop a PMC. 4469 */ 4470 4471 case PMC_OP_PMCSTOP: 4472 { 4473 pmc_id_t pmcid; 4474 struct pmc *pm; 4475 struct pmc_op_simple sp; 4476 4477 PMC_DOWNGRADE_SX(); 4478 4479 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 4480 break; 4481 4482 pmcid = sp.pm_pmcid; 4483 4484 /* 4485 * Mark the PMC as inactive and invoke the MD stop 4486 * routines if needed. 4487 */ 4488 4489 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 4490 break; 4491 4492 KASSERT(pmcid == pm->pm_id, 4493 ("[pmc,%d] pmc id %x != pmcid %x", __LINE__, 4494 pm->pm_id, pmcid)); 4495 4496 if (pm->pm_state == PMC_STATE_STOPPED) /* already stopped */ 4497 break; 4498 else if (pm->pm_state != PMC_STATE_RUNNING) { 4499 error = EINVAL; 4500 break; 4501 } 4502 4503 error = pmc_stop(pm); 4504 } 4505 break; 4506 4507 4508 /* 4509 * Write a user supplied value to the log file. 4510 */ 4511 4512 case PMC_OP_WRITELOG: 4513 { 4514 struct pmc_op_writelog wl; 4515 struct pmc_owner *po; 4516 4517 PMC_DOWNGRADE_SX(); 4518 4519 if ((error = copyin(arg, &wl, sizeof(wl))) != 0) 4520 break; 4521 4522 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 4523 error = EINVAL; 4524 break; 4525 } 4526 4527 if ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) { 4528 error = EINVAL; 4529 break; 4530 } 4531 4532 error = pmclog_process_userlog(po, &wl); 4533 } 4534 break; 4535 4536 4537 default: 4538 error = EINVAL; 4539 break; 4540 } 4541 4542 if (is_sx_downgraded) 4543 sx_sunlock(&pmc_sx); 4544 else 4545 sx_xunlock(&pmc_sx); 4546 done_syscall: 4547 if (error) 4548 counter_u64_add(pmc_stats.pm_syscall_errors, 1); 4549 4550 return (error); 4551 } 4552 4553 /* 4554 * Helper functions 4555 */ 4556 4557 /* 4558 * Mark the thread as needing callchain capture and post an AST. The 4559 * actual callchain capture will be done in a context where it is safe 4560 * to take page faults. 4561 */ 4562 static void 4563 pmc_post_callchain_callback(void) 4564 { 4565 struct thread *td; 4566 4567 td = curthread; 4568 4569 /* 4570 * If there is multiple PMCs for the same interrupt ignore new post 4571 */ 4572 if ((td->td_pflags & TDP_CALLCHAIN) != 0) 4573 return; 4574 4575 /* 4576 * Mark this thread as needing callchain capture. 4577 * `td->td_pflags' will be safe to touch because this thread 4578 * was in user space when it was interrupted. 4579 */ 4580 td->td_pflags |= TDP_CALLCHAIN; 4581 4582 /* 4583 * Don't let this thread migrate between CPUs until callchain 4584 * capture completes. 4585 */ 4586 sched_pin(); 4587 4588 return; 4589 } 4590 4591 /* 4592 * Find a free slot in the per-cpu array of samples and capture the 4593 * current callchain there. If a sample was successfully added, a bit 4594 * is set in mask 'pmc_cpumask' denoting that the DO_SAMPLES hook 4595 * needs to be invoked from the clock handler. 4596 * 4597 * This function is meant to be called from an NMI handler. It cannot 4598 * use any of the locking primitives supplied by the OS. 4599 */ 4600 static int 4601 pmc_add_sample(ring_type_t ring, struct pmc *pm, struct trapframe *tf) 4602 { 4603 struct pmc_sample *ps; 4604 struct pmc_samplebuffer *psb; 4605 struct thread *td; 4606 int error, cpu, callchaindepth; 4607 bool inuserspace; 4608 4609 error = 0; 4610 4611 /* 4612 * Allocate space for a sample buffer. 4613 */ 4614 cpu = curcpu; 4615 psb = pmc_pcpu[cpu]->pc_sb[ring]; 4616 inuserspace = TRAPF_USERMODE(tf); 4617 ps = PMC_PROD_SAMPLE(psb); 4618 if (psb->ps_considx != psb->ps_prodidx && 4619 ps->ps_nsamples) { /* in use, reader hasn't caught up */ 4620 pm->pm_pcpu_state[cpu].pps_stalled = 1; 4621 counter_u64_add(pmc_stats.pm_intr_bufferfull, 1); 4622 PMCDBG6(SAM,INT,1,"(spc) cpu=%d pm=%p tf=%p um=%d wr=%d rd=%d", 4623 cpu, pm, tf, inuserspace, 4624 (int)(psb->ps_prodidx & pmc_sample_mask), 4625 (int)(psb->ps_considx & pmc_sample_mask)); 4626 callchaindepth = 1; 4627 error = ENOMEM; 4628 goto done; 4629 } 4630 4631 /* Fill in entry. */ 4632 PMCDBG6(SAM,INT,1,"cpu=%d pm=%p tf=%p um=%d wr=%d rd=%d", cpu, pm, tf, 4633 inuserspace, (int)(psb->ps_prodidx & pmc_sample_mask), 4634 (int)(psb->ps_considx & pmc_sample_mask)); 4635 4636 td = curthread; 4637 ps->ps_pmc = pm; 4638 ps->ps_td = td; 4639 ps->ps_pid = td->td_proc->p_pid; 4640 ps->ps_tid = td->td_tid; 4641 ps->ps_tsc = pmc_rdtsc(); 4642 ps->ps_ticks = ticks; 4643 ps->ps_cpu = cpu; 4644 ps->ps_flags = inuserspace ? PMC_CC_F_USERSPACE : 0; 4645 4646 callchaindepth = (pm->pm_flags & PMC_F_CALLCHAIN) ? 4647 pmc_callchaindepth : 1; 4648 4649 MPASS(ps->ps_pc != NULL); 4650 if (callchaindepth == 1) { 4651 ps->ps_pc[0] = PMC_TRAPFRAME_TO_PC(tf); 4652 } else { 4653 /* 4654 * Kernel stack traversals can be done immediately, while we 4655 * defer to an AST for user space traversals. 4656 */ 4657 if (!inuserspace) { 4658 callchaindepth = pmc_save_kernel_callchain(ps->ps_pc, 4659 callchaindepth, tf); 4660 } else { 4661 pmc_post_callchain_callback(); 4662 callchaindepth = PMC_USER_CALLCHAIN_PENDING; 4663 } 4664 } 4665 4666 ps->ps_nsamples = callchaindepth; /* mark entry as in-use */ 4667 if (ring == PMC_UR) { 4668 ps->ps_nsamples_actual = callchaindepth; 4669 ps->ps_nsamples = PMC_USER_CALLCHAIN_PENDING; 4670 } 4671 4672 KASSERT(counter_u64_fetch(pm->pm_runcount) >= 0, 4673 ("[pmc,%d] pm=%p runcount %ju", __LINE__, pm, 4674 (uintmax_t)counter_u64_fetch(pm->pm_runcount))); 4675 4676 counter_u64_add(pm->pm_runcount, 1); /* hold onto PMC */ 4677 /* increment write pointer */ 4678 psb->ps_prodidx++; 4679 done: 4680 /* mark CPU as needing processing */ 4681 if (callchaindepth != PMC_USER_CALLCHAIN_PENDING) 4682 DPCPU_SET(pmc_sampled, 1); 4683 4684 return (error); 4685 } 4686 4687 /* 4688 * Interrupt processing. 4689 * 4690 * This function may be called from an NMI handler. It cannot use any of the 4691 * locking primitives supplied by the OS. 4692 */ 4693 int 4694 pmc_process_interrupt(int ring, struct pmc *pm, struct trapframe *tf) 4695 { 4696 struct thread *td; 4697 4698 td = curthread; 4699 if ((pm->pm_flags & PMC_F_USERCALLCHAIN) && 4700 (td->td_proc->p_flag & P_KPROC) == 0 && !TRAPF_USERMODE(tf)) { 4701 atomic_add_int(&td->td_pmcpend, 1); 4702 return (pmc_add_sample(PMC_UR, pm, tf)); 4703 } 4704 return (pmc_add_sample(ring, pm, tf)); 4705 } 4706 4707 /* 4708 * Capture a user call chain. This function will be called from ast() 4709 * before control returns to userland and before the process gets 4710 * rescheduled. 4711 */ 4712 static void 4713 pmc_capture_user_callchain(int cpu, int ring, struct trapframe *tf) 4714 { 4715 struct pmc *pm; 4716 struct pmc_sample *ps; 4717 struct pmc_samplebuffer *psb; 4718 struct thread *td; 4719 uint64_t considx, prodidx; 4720 int nsamples, nrecords, pass, iter; 4721 int start_ticks __diagused; 4722 4723 psb = pmc_pcpu[cpu]->pc_sb[ring]; 4724 td = curthread; 4725 nrecords = INT_MAX; 4726 pass = 0; 4727 start_ticks = ticks; 4728 4729 KASSERT(td->td_pflags & TDP_CALLCHAIN, 4730 ("[pmc,%d] Retrieving callchain for thread that doesn't want it", 4731 __LINE__)); 4732 restart: 4733 if (ring == PMC_UR) 4734 nrecords = atomic_readandclear_32(&td->td_pmcpend); 4735 4736 for (iter = 0, considx = psb->ps_considx, prodidx = psb->ps_prodidx; 4737 considx < prodidx && iter < pmc_nsamples; considx++, iter++) { 4738 ps = PMC_CONS_SAMPLE_OFF(psb, considx); 4739 4740 /* 4741 * Iterate through all deferred callchain requests. Walk from 4742 * the current read pointer to the current write pointer. 4743 */ 4744 #ifdef INVARIANTS 4745 if (ps->ps_nsamples == PMC_SAMPLE_FREE) { 4746 continue; 4747 } 4748 #endif 4749 if (ps->ps_td != td || 4750 ps->ps_nsamples != PMC_USER_CALLCHAIN_PENDING || 4751 ps->ps_pmc->pm_state != PMC_STATE_RUNNING) 4752 continue; 4753 4754 KASSERT(ps->ps_cpu == cpu, 4755 ("[pmc,%d] cpu mismatch ps_cpu=%d pcpu=%d", __LINE__, 4756 ps->ps_cpu, PCPU_GET(cpuid))); 4757 4758 pm = ps->ps_pmc; 4759 KASSERT(pm->pm_flags & PMC_F_CALLCHAIN, 4760 ("[pmc,%d] Retrieving callchain for PMC that doesn't " 4761 "want it", __LINE__)); 4762 KASSERT(counter_u64_fetch(pm->pm_runcount) > 0, 4763 ("[pmc,%d] runcount %ju", __LINE__, 4764 (uintmax_t)counter_u64_fetch(pm->pm_runcount))); 4765 4766 if (ring == PMC_UR) { 4767 nsamples = ps->ps_nsamples_actual; 4768 counter_u64_add(pmc_stats.pm_merges, 1); 4769 } else 4770 nsamples = 0; 4771 4772 /* 4773 * Retrieve the callchain and mark the sample buffer 4774 * as 'processable' by the timer tick sweep code. 4775 */ 4776 if (__predict_true(nsamples < pmc_callchaindepth - 1)) 4777 nsamples += pmc_save_user_callchain(ps->ps_pc + nsamples, 4778 pmc_callchaindepth - nsamples - 1, tf); 4779 4780 /* 4781 * We have to prevent hardclock from potentially overwriting 4782 * this sample between when we read the value and when we set 4783 * it. 4784 */ 4785 spinlock_enter(); 4786 4787 /* 4788 * Verify that the sample hasn't been dropped in the meantime. 4789 */ 4790 if (ps->ps_nsamples == PMC_USER_CALLCHAIN_PENDING) { 4791 ps->ps_nsamples = nsamples; 4792 /* 4793 * If we couldn't get a sample, simply drop the 4794 * reference. 4795 */ 4796 if (nsamples == 0) 4797 counter_u64_add(pm->pm_runcount, -1); 4798 } 4799 spinlock_exit(); 4800 if (nrecords-- == 1) 4801 break; 4802 } 4803 if (__predict_false(ring == PMC_UR && td->td_pmcpend)) { 4804 if (pass == 0) { 4805 pass = 1; 4806 goto restart; 4807 } 4808 /* only collect samples for this part once */ 4809 td->td_pmcpend = 0; 4810 } 4811 4812 #ifdef INVARIANTS 4813 if ((ticks - start_ticks) > hz) 4814 log(LOG_ERR, "%s took %d ticks\n", __func__, (ticks - start_ticks)); 4815 #endif 4816 /* mark CPU as needing processing */ 4817 DPCPU_SET(pmc_sampled, 1); 4818 } 4819 4820 /* 4821 * Process saved PC samples. 4822 */ 4823 static void 4824 pmc_process_samples(int cpu, ring_type_t ring) 4825 { 4826 struct pmc *pm; 4827 struct thread *td; 4828 struct pmc_owner *po; 4829 struct pmc_sample *ps; 4830 struct pmc_classdep *pcd; 4831 struct pmc_samplebuffer *psb; 4832 uint64_t delta __diagused; 4833 int adjri, n; 4834 4835 KASSERT(PCPU_GET(cpuid) == cpu, 4836 ("[pmc,%d] not on the correct CPU pcpu=%d cpu=%d", __LINE__, 4837 PCPU_GET(cpuid), cpu)); 4838 4839 psb = pmc_pcpu[cpu]->pc_sb[ring]; 4840 delta = psb->ps_prodidx - psb->ps_considx; 4841 MPASS(delta <= pmc_nsamples); 4842 MPASS(psb->ps_considx <= psb->ps_prodidx); 4843 for (n = 0; psb->ps_considx < psb->ps_prodidx; psb->ps_considx++, n++) { 4844 ps = PMC_CONS_SAMPLE(psb); 4845 4846 if (__predict_false(ps->ps_nsamples == PMC_SAMPLE_FREE)) 4847 continue; 4848 4849 /* skip non-running samples */ 4850 pm = ps->ps_pmc; 4851 if (pm->pm_state != PMC_STATE_RUNNING) 4852 goto entrydone; 4853 4854 KASSERT(counter_u64_fetch(pm->pm_runcount) > 0, 4855 ("[pmc,%d] pm=%p runcount %ju", __LINE__, pm, 4856 (uintmax_t)counter_u64_fetch(pm->pm_runcount))); 4857 KASSERT(PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)), 4858 ("[pmc,%d] pmc=%p non-sampling mode=%d", __LINE__, 4859 pm, PMC_TO_MODE(pm))); 4860 4861 po = pm->pm_owner; 4862 4863 /* If there is a pending AST wait for completion */ 4864 if (ps->ps_nsamples == PMC_USER_CALLCHAIN_PENDING) { 4865 /* 4866 * If we've been waiting more than 1 tick to 4867 * collect a callchain for this record then 4868 * drop it and move on. 4869 */ 4870 if (ticks - ps->ps_ticks > 1) { 4871 /* 4872 * Track how often we hit this as it will 4873 * preferentially lose user samples 4874 * for long running system calls. 4875 */ 4876 counter_u64_add(pmc_stats.pm_overwrites, 1); 4877 goto entrydone; 4878 } 4879 /* Need a rescan at a later time. */ 4880 DPCPU_SET(pmc_sampled, 1); 4881 break; 4882 } 4883 4884 PMCDBG6(SAM,OPS,1,"cpu=%d pm=%p n=%d fl=%x wr=%d rd=%d", cpu, 4885 pm, ps->ps_nsamples, ps->ps_flags, 4886 (int)(psb->ps_prodidx & pmc_sample_mask), 4887 (int)(psb->ps_considx & pmc_sample_mask)); 4888 4889 /* 4890 * If this is a process-mode PMC that is attached to 4891 * its owner, and if the PC is in user mode, update 4892 * profiling statistics like timer-based profiling 4893 * would have done. 4894 * 4895 * Otherwise, this is either a sampling-mode PMC that 4896 * is attached to a different process than its owner, 4897 * or a system-wide sampling PMC. Dispatch a log 4898 * entry to the PMC's owner process. 4899 */ 4900 if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) { 4901 if (ps->ps_flags & PMC_CC_F_USERSPACE) { 4902 td = FIRST_THREAD_IN_PROC(po->po_owner); 4903 addupc_intr(td, ps->ps_pc[0], 1); 4904 } 4905 } else 4906 pmclog_process_callchain(pm, ps); 4907 4908 entrydone: 4909 ps->ps_nsamples = 0; /* mark entry as free */ 4910 KASSERT(counter_u64_fetch(pm->pm_runcount) > 0, 4911 ("[pmc,%d] pm=%p runcount %ju", __LINE__, pm, 4912 (uintmax_t)counter_u64_fetch(pm->pm_runcount))); 4913 4914 counter_u64_add(pm->pm_runcount, -1); 4915 } 4916 4917 counter_u64_add(pmc_stats.pm_log_sweeps, 1); 4918 4919 /* Do not re-enable stalled PMCs if we failed to process any samples */ 4920 if (n == 0) 4921 return; 4922 4923 /* 4924 * Restart any stalled sampling PMCs on this CPU. 4925 * 4926 * If the NMI handler sets the pm_stalled field of a PMC after 4927 * the check below, we'll end up processing the stalled PMC at 4928 * the next hardclock tick. 4929 */ 4930 for (n = 0; n < md->pmd_npmc; n++) { 4931 pcd = pmc_ri_to_classdep(md, n, &adjri); 4932 KASSERT(pcd != NULL, 4933 ("[pmc,%d] null pcd ri=%d", __LINE__, n)); 4934 (void)(*pcd->pcd_get_config)(cpu, adjri, &pm); 4935 4936 if (pm == NULL || /* !cfg'ed */ 4937 pm->pm_state != PMC_STATE_RUNNING || /* !active */ 4938 !PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)) || /* !sampling */ 4939 !pm->pm_pcpu_state[cpu].pps_cpustate || /* !desired */ 4940 !pm->pm_pcpu_state[cpu].pps_stalled) /* !stalled */ 4941 continue; 4942 4943 pm->pm_pcpu_state[cpu].pps_stalled = 0; 4944 (void)(*pcd->pcd_start_pmc)(cpu, adjri, pm); 4945 } 4946 } 4947 4948 /* 4949 * Event handlers. 4950 */ 4951 4952 /* 4953 * Handle a process exit. 4954 * 4955 * Remove this process from all hash tables. If this process 4956 * owned any PMCs, turn off those PMCs and deallocate them, 4957 * removing any associations with target processes. 4958 * 4959 * This function will be called by the last 'thread' of a 4960 * process. 4961 * 4962 * XXX This eventhandler gets called early in the exit process. 4963 * Consider using a 'hook' invocation from thread_exit() or equivalent 4964 * spot. Another negative is that kse_exit doesn't seem to call 4965 * exit1() [??]. 4966 */ 4967 static void 4968 pmc_process_exit(void *arg __unused, struct proc *p) 4969 { 4970 struct pmc *pm; 4971 struct pmc_owner *po; 4972 struct pmc_process *pp; 4973 struct pmc_classdep *pcd; 4974 pmc_value_t newvalue, tmp; 4975 int ri, adjri, cpu; 4976 bool is_using_hwpmcs; 4977 4978 PROC_LOCK(p); 4979 is_using_hwpmcs = (p->p_flag & P_HWPMC) != 0; 4980 PROC_UNLOCK(p); 4981 4982 /* 4983 * Log a sysexit event to all SS PMC owners. 4984 */ 4985 PMC_EPOCH_ENTER(); 4986 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) { 4987 if ((po->po_flags & PMC_PO_OWNS_LOGFILE) != 0) 4988 pmclog_process_sysexit(po, p->p_pid); 4989 } 4990 PMC_EPOCH_EXIT(); 4991 4992 PMC_GET_SX_XLOCK(); 4993 PMCDBG3(PRC,EXT,1,"process-exit proc=%p (%d, %s)", p, p->p_pid, 4994 p->p_comm); 4995 4996 if (!is_using_hwpmcs) 4997 goto out; 4998 4999 /* 5000 * Since this code is invoked by the last thread in an exiting process, 5001 * we would have context switched IN at some prior point. However, with 5002 * PREEMPTION, kernel mode context switches may happen any time, so we 5003 * want to disable a context switch OUT till we get any PMCs targeting 5004 * this process off the hardware. 5005 * 5006 * We also need to atomically remove this process' entry from our 5007 * target process hash table, using PMC_FLAG_REMOVE. 5008 */ 5009 PMCDBG3(PRC,EXT,1, "process-exit proc=%p (%d, %s)", p, p->p_pid, 5010 p->p_comm); 5011 5012 critical_enter(); /* no preemption */ 5013 5014 cpu = curthread->td_oncpu; 5015 5016 pp = pmc_find_process_descriptor(p, PMC_FLAG_REMOVE); 5017 if (pp == NULL) { 5018 critical_exit(); 5019 goto out; 5020 } 5021 5022 PMCDBG2(PRC,EXT,2, "process-exit proc=%p pmc-process=%p", p, pp); 5023 5024 /* 5025 * The exiting process could be the target of some PMCs which will be 5026 * running on currently executing CPU. 5027 * 5028 * We need to turn these PMCs off like we would do at context switch 5029 * OUT time. 5030 */ 5031 for (ri = 0; ri < md->pmd_npmc; ri++) { 5032 /* 5033 * Pick up the pmc pointer from hardware state similar to the 5034 * CSW_OUT code. 5035 */ 5036 pm = NULL; 5037 pcd = pmc_ri_to_classdep(md, ri, &adjri); 5038 5039 (void)(*pcd->pcd_get_config)(cpu, adjri, &pm); 5040 5041 PMCDBG2(PRC,EXT,2, "ri=%d pm=%p", ri, pm); 5042 5043 if (pm == NULL || !PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) 5044 continue; 5045 5046 PMCDBG4(PRC,EXT,2, "ppmcs[%d]=%p pm=%p state=%d", ri, 5047 pp->pp_pmcs[ri].pp_pmc, pm, pm->pm_state); 5048 5049 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 5050 ("[pmc,%d] ri mismatch pmc(%d) ri(%d)", __LINE__, 5051 PMC_TO_ROWINDEX(pm), ri)); 5052 KASSERT(pm == pp->pp_pmcs[ri].pp_pmc, 5053 ("[pmc,%d] pm %p != pp_pmcs[%d] %p", __LINE__, pm, ri, 5054 pp->pp_pmcs[ri].pp_pmc)); 5055 KASSERT(counter_u64_fetch(pm->pm_runcount) > 0, 5056 ("[pmc,%d] bad runcount ri %d rc %ju", __LINE__, ri, 5057 (uintmax_t)counter_u64_fetch(pm->pm_runcount))); 5058 5059 /* 5060 * Change desired state, and then stop if not stalled. This 5061 * two-step dance should avoid race conditions where an 5062 * interrupt re-enables the PMC after this code has already 5063 * checked the pm_stalled flag. 5064 */ 5065 if (pm->pm_pcpu_state[cpu].pps_cpustate) { 5066 pm->pm_pcpu_state[cpu].pps_cpustate = 0; 5067 if (!pm->pm_pcpu_state[cpu].pps_stalled) { 5068 (void)pcd->pcd_stop_pmc(cpu, adjri, pm); 5069 5070 if (PMC_TO_MODE(pm) == PMC_MODE_TC) { 5071 pcd->pcd_read_pmc(cpu, adjri, pm, 5072 &newvalue); 5073 tmp = newvalue - PMC_PCPU_SAVED(cpu, ri); 5074 5075 mtx_pool_lock_spin(pmc_mtxpool, pm); 5076 pm->pm_gv.pm_savedvalue += tmp; 5077 pp->pp_pmcs[ri].pp_pmcval += tmp; 5078 mtx_pool_unlock_spin(pmc_mtxpool, pm); 5079 } 5080 } 5081 } 5082 5083 KASSERT(counter_u64_fetch(pm->pm_runcount) > 0, 5084 ("[pmc,%d] runcount is %d", __LINE__, ri)); 5085 5086 counter_u64_add(pm->pm_runcount, -1); 5087 (void)pcd->pcd_config_pmc(cpu, adjri, NULL); 5088 } 5089 5090 /* 5091 * Inform the MD layer of this pseudo "context switch out". 5092 */ 5093 (void)md->pmd_switch_out(pmc_pcpu[cpu], pp); 5094 5095 critical_exit(); /* ok to be pre-empted now */ 5096 5097 /* 5098 * Unlink this process from the PMCs that are targeting it. This will 5099 * send a signal to all PMC owner's whose PMCs are orphaned. 5100 * 5101 * Log PMC value at exit time if requested. 5102 */ 5103 for (ri = 0; ri < md->pmd_npmc; ri++) { 5104 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) { 5105 if ((pm->pm_flags & PMC_F_NEEDS_LOGFILE) != 0 && 5106 PMC_IS_COUNTING_MODE(PMC_TO_MODE(pm))) { 5107 pmclog_process_procexit(pm, pp); 5108 } 5109 pmc_unlink_target_process(pm, pp); 5110 } 5111 } 5112 free(pp, M_PMC); 5113 5114 out: 5115 /* 5116 * If the process owned PMCs, free them up and free up memory. 5117 */ 5118 if ((po = pmc_find_owner_descriptor(p)) != NULL) { 5119 if ((po->po_flags & PMC_PO_OWNS_LOGFILE) != 0) 5120 pmclog_close(po); 5121 pmc_remove_owner(po); 5122 pmc_destroy_owner_descriptor(po); 5123 } 5124 5125 sx_xunlock(&pmc_sx); 5126 } 5127 5128 /* 5129 * Handle a process fork. 5130 * 5131 * If the parent process 'p1' is under HWPMC monitoring, then copy 5132 * over any attached PMCs that have 'do_descendants' semantics. 5133 */ 5134 static void 5135 pmc_process_fork(void *arg __unused, struct proc *p1, struct proc *newproc, 5136 int flags __unused) 5137 { 5138 struct pmc *pm; 5139 struct pmc_owner *po; 5140 struct pmc_process *ppnew, *ppold; 5141 unsigned int ri; 5142 bool is_using_hwpmcs, do_descendants; 5143 5144 PROC_LOCK(p1); 5145 is_using_hwpmcs = (p1->p_flag & P_HWPMC) != 0; 5146 PROC_UNLOCK(p1); 5147 5148 /* 5149 * If there are system-wide sampling PMCs active, we need to 5150 * log all fork events to their owner's logs. 5151 */ 5152 PMC_EPOCH_ENTER(); 5153 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) { 5154 if (po->po_flags & PMC_PO_OWNS_LOGFILE) { 5155 pmclog_process_procfork(po, p1->p_pid, newproc->p_pid); 5156 pmclog_process_proccreate(po, newproc, 1); 5157 } 5158 } 5159 PMC_EPOCH_EXIT(); 5160 5161 if (!is_using_hwpmcs) 5162 return; 5163 5164 PMC_GET_SX_XLOCK(); 5165 PMCDBG4(PMC,FRK,1, "process-fork proc=%p (%d, %s) -> %p", p1, 5166 p1->p_pid, p1->p_comm, newproc); 5167 5168 /* 5169 * If the parent process (curthread->td_proc) is a 5170 * target of any PMCs, look for PMCs that are to be 5171 * inherited, and link these into the new process 5172 * descriptor. 5173 */ 5174 ppold = pmc_find_process_descriptor(curthread->td_proc, PMC_FLAG_NONE); 5175 if (ppold == NULL) 5176 goto done; /* nothing to do */ 5177 5178 do_descendants = false; 5179 for (ri = 0; ri < md->pmd_npmc; ri++) { 5180 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL && 5181 (pm->pm_flags & PMC_F_DESCENDANTS) != 0) { 5182 do_descendants = true; 5183 break; 5184 } 5185 } 5186 if (!do_descendants) /* nothing to do */ 5187 goto done; 5188 5189 /* 5190 * Now mark the new process as being tracked by this driver. 5191 */ 5192 PROC_LOCK(newproc); 5193 newproc->p_flag |= P_HWPMC; 5194 PROC_UNLOCK(newproc); 5195 5196 /* Allocate a descriptor for the new process. */ 5197 ppnew = pmc_find_process_descriptor(newproc, PMC_FLAG_ALLOCATE); 5198 if (ppnew == NULL) 5199 goto done; 5200 5201 /* 5202 * Run through all PMCs that were targeting the old process 5203 * and which specified F_DESCENDANTS and attach them to the 5204 * new process. 5205 * 5206 * Log the fork event to all owners of PMCs attached to this 5207 * process, if not already logged. 5208 */ 5209 for (ri = 0; ri < md->pmd_npmc; ri++) { 5210 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL && 5211 (pm->pm_flags & PMC_F_DESCENDANTS) != 0) { 5212 pmc_link_target_process(pm, ppnew); 5213 po = pm->pm_owner; 5214 if (po->po_sscount == 0 && 5215 (po->po_flags & PMC_PO_OWNS_LOGFILE) != 0) { 5216 pmclog_process_procfork(po, p1->p_pid, 5217 newproc->p_pid); 5218 } 5219 } 5220 } 5221 5222 done: 5223 sx_xunlock(&pmc_sx); 5224 } 5225 5226 static void 5227 pmc_process_threadcreate(struct thread *td) 5228 { 5229 struct pmc_owner *po; 5230 5231 PMC_EPOCH_ENTER(); 5232 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) { 5233 if ((po->po_flags & PMC_PO_OWNS_LOGFILE) != 0) 5234 pmclog_process_threadcreate(po, td, 1); 5235 } 5236 PMC_EPOCH_EXIT(); 5237 } 5238 5239 static void 5240 pmc_process_threadexit(struct thread *td) 5241 { 5242 struct pmc_owner *po; 5243 5244 PMC_EPOCH_ENTER(); 5245 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) { 5246 if ((po->po_flags & PMC_PO_OWNS_LOGFILE) != 0) 5247 pmclog_process_threadexit(po, td); 5248 } 5249 PMC_EPOCH_EXIT(); 5250 } 5251 5252 static void 5253 pmc_process_proccreate(struct proc *p) 5254 { 5255 struct pmc_owner *po; 5256 5257 PMC_EPOCH_ENTER(); 5258 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) { 5259 if ((po->po_flags & PMC_PO_OWNS_LOGFILE) != 0) 5260 pmclog_process_proccreate(po, p, 1 /* sync */); 5261 } 5262 PMC_EPOCH_EXIT(); 5263 } 5264 5265 static void 5266 pmc_process_allproc(struct pmc *pm) 5267 { 5268 struct pmc_owner *po; 5269 struct thread *td; 5270 struct proc *p; 5271 5272 po = pm->pm_owner; 5273 if ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) 5274 return; 5275 5276 sx_slock(&allproc_lock); 5277 FOREACH_PROC_IN_SYSTEM(p) { 5278 pmclog_process_proccreate(po, p, 0 /* sync */); 5279 PROC_LOCK(p); 5280 FOREACH_THREAD_IN_PROC(p, td) 5281 pmclog_process_threadcreate(po, td, 0 /* sync */); 5282 PROC_UNLOCK(p); 5283 } 5284 sx_sunlock(&allproc_lock); 5285 pmclog_flush(po, 0); 5286 } 5287 5288 static void 5289 pmc_kld_load(void *arg __unused, linker_file_t lf) 5290 { 5291 struct pmc_owner *po; 5292 5293 /* 5294 * Notify owners of system sampling PMCs about KLD operations. 5295 */ 5296 PMC_EPOCH_ENTER(); 5297 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) { 5298 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 5299 pmclog_process_map_in(po, (pid_t) -1, 5300 (uintfptr_t) lf->address, lf->pathname); 5301 } 5302 PMC_EPOCH_EXIT(); 5303 5304 /* 5305 * TODO: Notify owners of (all) process-sampling PMCs too. 5306 */ 5307 } 5308 5309 static void 5310 pmc_kld_unload(void *arg __unused, const char *filename __unused, 5311 caddr_t address, size_t size) 5312 { 5313 struct pmc_owner *po; 5314 5315 PMC_EPOCH_ENTER(); 5316 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) { 5317 if ((po->po_flags & PMC_PO_OWNS_LOGFILE) != 0) { 5318 pmclog_process_map_out(po, (pid_t)-1, 5319 (uintfptr_t)address, (uintfptr_t)address + size); 5320 } 5321 } 5322 PMC_EPOCH_EXIT(); 5323 5324 /* 5325 * TODO: Notify owners of process-sampling PMCs. 5326 */ 5327 } 5328 5329 /* 5330 * initialization 5331 */ 5332 static const char * 5333 pmc_name_of_pmcclass(enum pmc_class class) 5334 { 5335 5336 switch (class) { 5337 #undef __PMC_CLASS 5338 #define __PMC_CLASS(S,V,D) \ 5339 case PMC_CLASS_##S: \ 5340 return #S; 5341 __PMC_CLASSES(); 5342 default: 5343 return ("<unknown>"); 5344 } 5345 } 5346 5347 /* 5348 * Base class initializer: allocate structure and set default classes. 5349 */ 5350 struct pmc_mdep * 5351 pmc_mdep_alloc(int nclasses) 5352 { 5353 struct pmc_mdep *md; 5354 int n; 5355 5356 /* SOFT + md classes */ 5357 n = 1 + nclasses; 5358 md = malloc(sizeof(struct pmc_mdep) + n * sizeof(struct pmc_classdep), 5359 M_PMC, M_WAITOK | M_ZERO); 5360 md->pmd_nclass = n; 5361 5362 /* Default methods */ 5363 md->pmd_switch_in = generic_switch_in; 5364 md->pmd_switch_out = generic_switch_out; 5365 5366 /* Add base class. */ 5367 pmc_soft_initialize(md); 5368 return (md); 5369 } 5370 5371 void 5372 pmc_mdep_free(struct pmc_mdep *md) 5373 { 5374 pmc_soft_finalize(md); 5375 free(md, M_PMC); 5376 } 5377 5378 static int 5379 generic_switch_in(struct pmc_cpu *pc __unused, struct pmc_process *pp __unused) 5380 { 5381 5382 return (0); 5383 } 5384 5385 static int 5386 generic_switch_out(struct pmc_cpu *pc __unused, struct pmc_process *pp __unused) 5387 { 5388 5389 return (0); 5390 } 5391 5392 static struct pmc_mdep * 5393 pmc_generic_cpu_initialize(void) 5394 { 5395 struct pmc_mdep *md; 5396 5397 md = pmc_mdep_alloc(0); 5398 5399 md->pmd_cputype = PMC_CPU_GENERIC; 5400 5401 return (md); 5402 } 5403 5404 static void 5405 pmc_generic_cpu_finalize(struct pmc_mdep *md __unused) 5406 { 5407 5408 } 5409 5410 static int 5411 pmc_initialize(void) 5412 { 5413 struct pcpu *pc; 5414 struct pmc_binding pb; 5415 struct pmc_classdep *pcd; 5416 struct pmc_sample *ps; 5417 struct pmc_samplebuffer *sb; 5418 int c, cpu, error, n, ri; 5419 u_int maxcpu, domain; 5420 5421 md = NULL; 5422 error = 0; 5423 5424 pmc_stats.pm_intr_ignored = counter_u64_alloc(M_WAITOK); 5425 pmc_stats.pm_intr_processed = counter_u64_alloc(M_WAITOK); 5426 pmc_stats.pm_intr_bufferfull = counter_u64_alloc(M_WAITOK); 5427 pmc_stats.pm_syscalls = counter_u64_alloc(M_WAITOK); 5428 pmc_stats.pm_syscall_errors = counter_u64_alloc(M_WAITOK); 5429 pmc_stats.pm_buffer_requests = counter_u64_alloc(M_WAITOK); 5430 pmc_stats.pm_buffer_requests_failed = counter_u64_alloc(M_WAITOK); 5431 pmc_stats.pm_log_sweeps = counter_u64_alloc(M_WAITOK); 5432 pmc_stats.pm_merges = counter_u64_alloc(M_WAITOK); 5433 pmc_stats.pm_overwrites = counter_u64_alloc(M_WAITOK); 5434 5435 #ifdef HWPMC_DEBUG 5436 /* parse debug flags first */ 5437 if (TUNABLE_STR_FETCH(PMC_SYSCTL_NAME_PREFIX "debugflags", 5438 pmc_debugstr, sizeof(pmc_debugstr))) { 5439 pmc_debugflags_parse(pmc_debugstr, pmc_debugstr + 5440 strlen(pmc_debugstr)); 5441 } 5442 #endif 5443 5444 PMCDBG1(MOD,INI,0, "PMC Initialize (version %x)", PMC_VERSION); 5445 5446 /* check kernel version */ 5447 if (pmc_kernel_version != PMC_VERSION) { 5448 if (pmc_kernel_version == 0) 5449 printf("hwpmc: this kernel has not been compiled with " 5450 "'options HWPMC_HOOKS'.\n"); 5451 else 5452 printf("hwpmc: kernel version (0x%x) does not match " 5453 "module version (0x%x).\n", pmc_kernel_version, 5454 PMC_VERSION); 5455 return (EPROGMISMATCH); 5456 } 5457 5458 /* 5459 * check sysctl parameters 5460 */ 5461 if (pmc_hashsize <= 0) { 5462 printf("hwpmc: tunable \"hashsize\"=%d must be " 5463 "greater than zero.\n", pmc_hashsize); 5464 pmc_hashsize = PMC_HASH_SIZE; 5465 } 5466 5467 if (pmc_nsamples <= 0 || pmc_nsamples > 65535) { 5468 printf("hwpmc: tunable \"nsamples\"=%d out of " 5469 "range.\n", pmc_nsamples); 5470 pmc_nsamples = PMC_NSAMPLES; 5471 } 5472 pmc_sample_mask = pmc_nsamples - 1; 5473 5474 if (pmc_callchaindepth <= 0 || 5475 pmc_callchaindepth > PMC_CALLCHAIN_DEPTH_MAX) { 5476 printf("hwpmc: tunable \"callchaindepth\"=%d out of " 5477 "range - using %d.\n", pmc_callchaindepth, 5478 PMC_CALLCHAIN_DEPTH_MAX); 5479 pmc_callchaindepth = PMC_CALLCHAIN_DEPTH_MAX; 5480 } 5481 5482 md = pmc_md_initialize(); 5483 if (md == NULL) { 5484 /* Default to generic CPU. */ 5485 md = pmc_generic_cpu_initialize(); 5486 if (md == NULL) 5487 return (ENOSYS); 5488 } 5489 5490 /* 5491 * Refresh classes base ri. Optional classes may come in different 5492 * order. 5493 */ 5494 for (ri = c = 0; c < md->pmd_nclass; c++) { 5495 pcd = &md->pmd_classdep[c]; 5496 pcd->pcd_ri = ri; 5497 ri += pcd->pcd_num; 5498 } 5499 5500 KASSERT(md->pmd_nclass >= 1 && md->pmd_npmc >= 1, 5501 ("[pmc,%d] no classes or pmcs", __LINE__)); 5502 5503 /* Compute the map from row-indices to classdep pointers. */ 5504 pmc_rowindex_to_classdep = malloc(sizeof(struct pmc_classdep *) * 5505 md->pmd_npmc, M_PMC, M_WAITOK | M_ZERO); 5506 5507 for (n = 0; n < md->pmd_npmc; n++) 5508 pmc_rowindex_to_classdep[n] = NULL; 5509 5510 for (ri = c = 0; c < md->pmd_nclass; c++) { 5511 pcd = &md->pmd_classdep[c]; 5512 for (n = 0; n < pcd->pcd_num; n++, ri++) 5513 pmc_rowindex_to_classdep[ri] = pcd; 5514 } 5515 5516 KASSERT(ri == md->pmd_npmc, 5517 ("[pmc,%d] npmc miscomputed: ri=%d, md->npmc=%d", __LINE__, 5518 ri, md->pmd_npmc)); 5519 5520 maxcpu = pmc_cpu_max(); 5521 5522 /* allocate space for the per-cpu array */ 5523 pmc_pcpu = malloc(maxcpu * sizeof(struct pmc_cpu *), M_PMC, 5524 M_WAITOK | M_ZERO); 5525 5526 /* per-cpu 'saved values' for managing process-mode PMCs */ 5527 pmc_pcpu_saved = malloc(sizeof(pmc_value_t) * maxcpu * md->pmd_npmc, 5528 M_PMC, M_WAITOK); 5529 5530 /* Perform CPU-dependent initialization. */ 5531 pmc_save_cpu_binding(&pb); 5532 error = 0; 5533 for (cpu = 0; error == 0 && cpu < maxcpu; cpu++) { 5534 if (!pmc_cpu_is_active(cpu)) 5535 continue; 5536 pmc_select_cpu(cpu); 5537 pmc_pcpu[cpu] = malloc(sizeof(struct pmc_cpu) + 5538 md->pmd_npmc * sizeof(struct pmc_hw *), M_PMC, 5539 M_WAITOK | M_ZERO); 5540 for (n = 0; error == 0 && n < md->pmd_nclass; n++) 5541 if (md->pmd_classdep[n].pcd_num > 0) 5542 error = md->pmd_classdep[n].pcd_pcpu_init(md, 5543 cpu); 5544 } 5545 pmc_restore_cpu_binding(&pb); 5546 5547 if (error != 0) 5548 return (error); 5549 5550 /* allocate space for the sample array */ 5551 for (cpu = 0; cpu < maxcpu; cpu++) { 5552 if (!pmc_cpu_is_active(cpu)) 5553 continue; 5554 pc = pcpu_find(cpu); 5555 domain = pc->pc_domain; 5556 sb = malloc_domainset(sizeof(struct pmc_samplebuffer) + 5557 pmc_nsamples * sizeof(struct pmc_sample), M_PMC, 5558 DOMAINSET_PREF(domain), M_WAITOK | M_ZERO); 5559 5560 KASSERT(pmc_pcpu[cpu] != NULL, 5561 ("[pmc,%d] cpu=%d Null per-cpu data", __LINE__, cpu)); 5562 5563 sb->ps_callchains = malloc_domainset(pmc_callchaindepth * 5564 pmc_nsamples * sizeof(uintptr_t), M_PMC, 5565 DOMAINSET_PREF(domain), M_WAITOK | M_ZERO); 5566 5567 for (n = 0, ps = sb->ps_samples; n < pmc_nsamples; n++, ps++) 5568 ps->ps_pc = sb->ps_callchains + 5569 (n * pmc_callchaindepth); 5570 5571 pmc_pcpu[cpu]->pc_sb[PMC_HR] = sb; 5572 5573 sb = malloc_domainset(sizeof(struct pmc_samplebuffer) + 5574 pmc_nsamples * sizeof(struct pmc_sample), M_PMC, 5575 DOMAINSET_PREF(domain), M_WAITOK | M_ZERO); 5576 5577 sb->ps_callchains = malloc_domainset(pmc_callchaindepth * 5578 pmc_nsamples * sizeof(uintptr_t), M_PMC, 5579 DOMAINSET_PREF(domain), M_WAITOK | M_ZERO); 5580 for (n = 0, ps = sb->ps_samples; n < pmc_nsamples; n++, ps++) 5581 ps->ps_pc = sb->ps_callchains + 5582 (n * pmc_callchaindepth); 5583 5584 pmc_pcpu[cpu]->pc_sb[PMC_SR] = sb; 5585 5586 sb = malloc_domainset(sizeof(struct pmc_samplebuffer) + 5587 pmc_nsamples * sizeof(struct pmc_sample), M_PMC, 5588 DOMAINSET_PREF(domain), M_WAITOK | M_ZERO); 5589 sb->ps_callchains = malloc_domainset(pmc_callchaindepth * 5590 pmc_nsamples * sizeof(uintptr_t), M_PMC, 5591 DOMAINSET_PREF(domain), M_WAITOK | M_ZERO); 5592 for (n = 0, ps = sb->ps_samples; n < pmc_nsamples; n++, ps++) 5593 ps->ps_pc = sb->ps_callchains + n * pmc_callchaindepth; 5594 5595 pmc_pcpu[cpu]->pc_sb[PMC_UR] = sb; 5596 } 5597 5598 /* allocate space for the row disposition array */ 5599 pmc_pmcdisp = malloc(sizeof(enum pmc_mode) * md->pmd_npmc, 5600 M_PMC, M_WAITOK | M_ZERO); 5601 5602 /* mark all PMCs as available */ 5603 for (n = 0; n < md->pmd_npmc; n++) 5604 PMC_MARK_ROW_FREE(n); 5605 5606 /* allocate thread hash tables */ 5607 pmc_ownerhash = hashinit(pmc_hashsize, M_PMC, 5608 &pmc_ownerhashmask); 5609 5610 pmc_processhash = hashinit(pmc_hashsize, M_PMC, 5611 &pmc_processhashmask); 5612 mtx_init(&pmc_processhash_mtx, "pmc-process-hash", "pmc-leaf", 5613 MTX_SPIN); 5614 5615 CK_LIST_INIT(&pmc_ss_owners); 5616 pmc_ss_count = 0; 5617 5618 /* allocate a pool of spin mutexes */ 5619 pmc_mtxpool = mtx_pool_create("pmc-leaf", pmc_mtxpool_size, 5620 MTX_SPIN); 5621 5622 PMCDBG4(MOD,INI,1, "pmc_ownerhash=%p, mask=0x%lx " 5623 "targethash=%p mask=0x%lx", pmc_ownerhash, pmc_ownerhashmask, 5624 pmc_processhash, pmc_processhashmask); 5625 5626 /* Initialize a spin mutex for the thread free list. */ 5627 mtx_init(&pmc_threadfreelist_mtx, "pmc-threadfreelist", "pmc-leaf", 5628 MTX_SPIN); 5629 5630 /* Initialize the task to prune the thread free list. */ 5631 TASK_INIT(&free_task, 0, pmc_thread_descriptor_pool_free_task, NULL); 5632 5633 /* register process {exit,fork,exec} handlers */ 5634 pmc_exit_tag = EVENTHANDLER_REGISTER(process_exit, 5635 pmc_process_exit, NULL, EVENTHANDLER_PRI_ANY); 5636 pmc_fork_tag = EVENTHANDLER_REGISTER(process_fork, 5637 pmc_process_fork, NULL, EVENTHANDLER_PRI_ANY); 5638 5639 /* register kld event handlers */ 5640 pmc_kld_load_tag = EVENTHANDLER_REGISTER(kld_load, pmc_kld_load, 5641 NULL, EVENTHANDLER_PRI_ANY); 5642 pmc_kld_unload_tag = EVENTHANDLER_REGISTER(kld_unload, pmc_kld_unload, 5643 NULL, EVENTHANDLER_PRI_ANY); 5644 5645 /* initialize logging */ 5646 pmclog_initialize(); 5647 5648 /* set hook functions */ 5649 pmc_intr = md->pmd_intr; 5650 wmb(); 5651 pmc_hook = pmc_hook_handler; 5652 5653 if (error == 0) { 5654 printf(PMC_MODULE_NAME ":"); 5655 for (n = 0; n < md->pmd_nclass; n++) { 5656 if (md->pmd_classdep[n].pcd_num == 0) 5657 continue; 5658 pcd = &md->pmd_classdep[n]; 5659 printf(" %s/%d/%d/0x%b", 5660 pmc_name_of_pmcclass(pcd->pcd_class), 5661 pcd->pcd_num, 5662 pcd->pcd_width, 5663 pcd->pcd_caps, 5664 "\20" 5665 "\1INT\2USR\3SYS\4EDG\5THR" 5666 "\6REA\7WRI\10INV\11QUA\12PRC" 5667 "\13TAG\14CSC"); 5668 } 5669 printf("\n"); 5670 } 5671 5672 return (error); 5673 } 5674 5675 /* prepare to be unloaded */ 5676 static void 5677 pmc_cleanup(void) 5678 { 5679 struct pmc_binding pb; 5680 struct pmc_owner *po, *tmp; 5681 struct pmc_ownerhash *ph; 5682 struct pmc_processhash *prh __pmcdbg_used; 5683 u_int maxcpu; 5684 int cpu, c; 5685 5686 PMCDBG0(MOD,INI,0, "cleanup"); 5687 5688 /* switch off sampling */ 5689 CPU_FOREACH(cpu) 5690 DPCPU_ID_SET(cpu, pmc_sampled, 0); 5691 pmc_intr = NULL; 5692 5693 sx_xlock(&pmc_sx); 5694 if (pmc_hook == NULL) { /* being unloaded already */ 5695 sx_xunlock(&pmc_sx); 5696 return; 5697 } 5698 5699 pmc_hook = NULL; /* prevent new threads from entering module */ 5700 5701 /* deregister event handlers */ 5702 EVENTHANDLER_DEREGISTER(process_fork, pmc_fork_tag); 5703 EVENTHANDLER_DEREGISTER(process_exit, pmc_exit_tag); 5704 EVENTHANDLER_DEREGISTER(kld_load, pmc_kld_load_tag); 5705 EVENTHANDLER_DEREGISTER(kld_unload, pmc_kld_unload_tag); 5706 5707 /* send SIGBUS to all owner threads, free up allocations */ 5708 if (pmc_ownerhash != NULL) { 5709 for (ph = pmc_ownerhash; 5710 ph <= &pmc_ownerhash[pmc_ownerhashmask]; 5711 ph++) { 5712 LIST_FOREACH_SAFE(po, ph, po_next, tmp) { 5713 pmc_remove_owner(po); 5714 5715 PMCDBG3(MOD,INI,2, 5716 "cleanup signal proc=%p (%d, %s)", 5717 po->po_owner, po->po_owner->p_pid, 5718 po->po_owner->p_comm); 5719 5720 PROC_LOCK(po->po_owner); 5721 kern_psignal(po->po_owner, SIGBUS); 5722 PROC_UNLOCK(po->po_owner); 5723 5724 pmc_destroy_owner_descriptor(po); 5725 } 5726 } 5727 } 5728 5729 /* reclaim allocated data structures */ 5730 taskqueue_drain(taskqueue_fast, &free_task); 5731 mtx_destroy(&pmc_threadfreelist_mtx); 5732 pmc_thread_descriptor_pool_drain(); 5733 5734 if (pmc_mtxpool != NULL) 5735 mtx_pool_destroy(&pmc_mtxpool); 5736 5737 mtx_destroy(&pmc_processhash_mtx); 5738 if (pmc_processhash != NULL) { 5739 #ifdef HWPMC_DEBUG 5740 struct pmc_process *pp; 5741 5742 PMCDBG0(MOD,INI,3, "destroy process hash"); 5743 for (prh = pmc_processhash; 5744 prh <= &pmc_processhash[pmc_processhashmask]; 5745 prh++) 5746 LIST_FOREACH(pp, prh, pp_next) 5747 PMCDBG1(MOD,INI,3, "pid=%d", pp->pp_proc->p_pid); 5748 #endif 5749 5750 hashdestroy(pmc_processhash, M_PMC, pmc_processhashmask); 5751 pmc_processhash = NULL; 5752 } 5753 5754 if (pmc_ownerhash != NULL) { 5755 PMCDBG0(MOD,INI,3, "destroy owner hash"); 5756 hashdestroy(pmc_ownerhash, M_PMC, pmc_ownerhashmask); 5757 pmc_ownerhash = NULL; 5758 } 5759 5760 KASSERT(CK_LIST_EMPTY(&pmc_ss_owners), 5761 ("[pmc,%d] Global SS owner list not empty", __LINE__)); 5762 KASSERT(pmc_ss_count == 0, 5763 ("[pmc,%d] Global SS count not empty", __LINE__)); 5764 5765 /* do processor and pmc-class dependent cleanup */ 5766 maxcpu = pmc_cpu_max(); 5767 5768 PMCDBG0(MOD,INI,3, "md cleanup"); 5769 if (md) { 5770 pmc_save_cpu_binding(&pb); 5771 for (cpu = 0; cpu < maxcpu; cpu++) { 5772 PMCDBG2(MOD,INI,1,"pmc-cleanup cpu=%d pcs=%p", 5773 cpu, pmc_pcpu[cpu]); 5774 if (!pmc_cpu_is_active(cpu) || pmc_pcpu[cpu] == NULL) 5775 continue; 5776 5777 pmc_select_cpu(cpu); 5778 for (c = 0; c < md->pmd_nclass; c++) { 5779 if (md->pmd_classdep[c].pcd_num > 0) { 5780 md->pmd_classdep[c].pcd_pcpu_fini(md, 5781 cpu); 5782 } 5783 } 5784 } 5785 5786 if (md->pmd_cputype == PMC_CPU_GENERIC) 5787 pmc_generic_cpu_finalize(md); 5788 else 5789 pmc_md_finalize(md); 5790 5791 pmc_mdep_free(md); 5792 md = NULL; 5793 pmc_restore_cpu_binding(&pb); 5794 } 5795 5796 /* Free per-cpu descriptors. */ 5797 for (cpu = 0; cpu < maxcpu; cpu++) { 5798 if (!pmc_cpu_is_active(cpu)) 5799 continue; 5800 KASSERT(pmc_pcpu[cpu]->pc_sb[PMC_HR] != NULL, 5801 ("[pmc,%d] Null hw cpu sample buffer cpu=%d", __LINE__, 5802 cpu)); 5803 KASSERT(pmc_pcpu[cpu]->pc_sb[PMC_SR] != NULL, 5804 ("[pmc,%d] Null sw cpu sample buffer cpu=%d", __LINE__, 5805 cpu)); 5806 KASSERT(pmc_pcpu[cpu]->pc_sb[PMC_UR] != NULL, 5807 ("[pmc,%d] Null userret cpu sample buffer cpu=%d", __LINE__, 5808 cpu)); 5809 free(pmc_pcpu[cpu]->pc_sb[PMC_HR]->ps_callchains, M_PMC); 5810 free(pmc_pcpu[cpu]->pc_sb[PMC_HR], M_PMC); 5811 free(pmc_pcpu[cpu]->pc_sb[PMC_SR]->ps_callchains, M_PMC); 5812 free(pmc_pcpu[cpu]->pc_sb[PMC_SR], M_PMC); 5813 free(pmc_pcpu[cpu]->pc_sb[PMC_UR]->ps_callchains, M_PMC); 5814 free(pmc_pcpu[cpu]->pc_sb[PMC_UR], M_PMC); 5815 free(pmc_pcpu[cpu], M_PMC); 5816 } 5817 5818 free(pmc_pcpu, M_PMC); 5819 pmc_pcpu = NULL; 5820 5821 free(pmc_pcpu_saved, M_PMC); 5822 pmc_pcpu_saved = NULL; 5823 5824 if (pmc_pmcdisp != NULL) { 5825 free(pmc_pmcdisp, M_PMC); 5826 pmc_pmcdisp = NULL; 5827 } 5828 5829 if (pmc_rowindex_to_classdep != NULL) { 5830 free(pmc_rowindex_to_classdep, M_PMC); 5831 pmc_rowindex_to_classdep = NULL; 5832 } 5833 5834 pmclog_shutdown(); 5835 counter_u64_free(pmc_stats.pm_intr_ignored); 5836 counter_u64_free(pmc_stats.pm_intr_processed); 5837 counter_u64_free(pmc_stats.pm_intr_bufferfull); 5838 counter_u64_free(pmc_stats.pm_syscalls); 5839 counter_u64_free(pmc_stats.pm_syscall_errors); 5840 counter_u64_free(pmc_stats.pm_buffer_requests); 5841 counter_u64_free(pmc_stats.pm_buffer_requests_failed); 5842 counter_u64_free(pmc_stats.pm_log_sweeps); 5843 counter_u64_free(pmc_stats.pm_merges); 5844 counter_u64_free(pmc_stats.pm_overwrites); 5845 sx_xunlock(&pmc_sx); /* we are done */ 5846 } 5847 5848 /* 5849 * The function called at load/unload. 5850 */ 5851 static int 5852 load(struct module *module __unused, int cmd, void *arg __unused) 5853 { 5854 int error; 5855 5856 error = 0; 5857 5858 switch (cmd) { 5859 case MOD_LOAD: 5860 /* initialize the subsystem */ 5861 error = pmc_initialize(); 5862 if (error != 0) 5863 break; 5864 PMCDBG2(MOD,INI,1, "syscall=%d maxcpu=%d", pmc_syscall_num, 5865 pmc_cpu_max()); 5866 break; 5867 case MOD_UNLOAD: 5868 case MOD_SHUTDOWN: 5869 pmc_cleanup(); 5870 PMCDBG0(MOD,INI,1, "unloaded"); 5871 break; 5872 default: 5873 error = EINVAL; 5874 break; 5875 } 5876 5877 return (error); 5878 } 5879