1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 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 35 #include <sys/cdefs.h> 36 __FBSDID("$FreeBSD$"); 37 38 #include <sys/param.h> 39 #include <sys/systm.h> 40 #include <sys/domainset.h> 41 #include <sys/eventhandler.h> 42 #include <sys/jail.h> 43 #include <sys/kernel.h> 44 #include <sys/kthread.h> 45 #include <sys/limits.h> 46 #include <sys/lock.h> 47 #include <sys/malloc.h> 48 #include <sys/module.h> 49 #include <sys/mount.h> 50 #include <sys/mutex.h> 51 #include <sys/pmc.h> 52 #include <sys/pmckern.h> 53 #include <sys/pmclog.h> 54 #include <sys/priv.h> 55 #include <sys/proc.h> 56 #include <sys/queue.h> 57 #include <sys/resourcevar.h> 58 #include <sys/rwlock.h> 59 #include <sys/sched.h> 60 #include <sys/signalvar.h> 61 #include <sys/smp.h> 62 #include <sys/sx.h> 63 #include <sys/sysctl.h> 64 #include <sys/sysent.h> 65 #include <sys/syslog.h> 66 #include <sys/taskqueue.h> 67 #include <sys/vnode.h> 68 69 #include <sys/linker.h> /* needs to be after <sys/malloc.h> */ 70 71 #include <machine/atomic.h> 72 #include <machine/md_var.h> 73 74 #include <vm/vm.h> 75 #include <vm/vm_extern.h> 76 #include <vm/pmap.h> 77 #include <vm/vm_map.h> 78 #include <vm/vm_object.h> 79 80 #include "hwpmc_soft.h" 81 82 #define PMC_EPOCH_ENTER() struct epoch_tracker pmc_et; epoch_enter_preempt(global_epoch_preempt, &pmc_et) 83 #define PMC_EPOCH_EXIT() 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 */ 99 100 static int pmc_syscall_num = NO_SYSCALL; 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) 142 143 144 /* various event handlers */ 145 static eventhandler_tag pmc_exit_tag, pmc_fork_tag, pmc_kld_load_tag, 146 pmc_kld_unload_tag; 147 148 /* Module statistics */ 149 struct pmc_driverstats pmc_stats; 150 151 152 /* Machine/processor dependent operations */ 153 static struct pmc_mdep *md; 154 155 /* 156 * Hash tables mapping owner processes and target threads to PMCs. 157 */ 158 159 struct mtx pmc_processhash_mtx; /* spin mutex */ 160 static u_long pmc_processhashmask; 161 static LIST_HEAD(pmc_processhash, pmc_process) *pmc_processhash; 162 163 /* 164 * Hash table of PMC owner descriptors. This table is protected by 165 * the shared PMC "sx" lock. 166 */ 167 168 static u_long pmc_ownerhashmask; 169 static LIST_HEAD(pmc_ownerhash, pmc_owner) *pmc_ownerhash; 170 171 /* 172 * List of PMC owners with system-wide sampling PMCs. 173 */ 174 175 static CK_LIST_HEAD(, pmc_owner) pmc_ss_owners; 176 177 /* 178 * List of free thread entries. This is protected by the spin 179 * mutex. 180 */ 181 static struct mtx pmc_threadfreelist_mtx; /* spin mutex */ 182 static LIST_HEAD(, pmc_thread) pmc_threadfreelist; 183 static int pmc_threadfreelist_entries=0; 184 #define THREADENTRY_SIZE \ 185 (sizeof(struct pmc_thread) + (md->pmd_npmc * sizeof(struct pmc_threadpmcstate))) 186 187 /* 188 * Task to free thread descriptors 189 */ 190 static struct task free_task; 191 192 /* 193 * A map of row indices to classdep structures. 194 */ 195 static struct pmc_classdep **pmc_rowindex_to_classdep; 196 197 /* 198 * Prototypes 199 */ 200 201 #ifdef HWPMC_DEBUG 202 static int pmc_debugflags_sysctl_handler(SYSCTL_HANDLER_ARGS); 203 static int pmc_debugflags_parse(char *newstr, char *fence); 204 #endif 205 206 static int load(struct module *module, int cmd, void *arg); 207 static int pmc_add_sample(ring_type_t ring, struct pmc *pm, struct trapframe *tf); 208 static void pmc_add_thread_descriptors_from_proc(struct proc *p, 209 struct pmc_process *pp); 210 static int pmc_attach_process(struct proc *p, struct pmc *pm); 211 static struct pmc *pmc_allocate_pmc_descriptor(void); 212 static struct pmc_owner *pmc_allocate_owner_descriptor(struct proc *p); 213 static int pmc_attach_one_process(struct proc *p, struct pmc *pm); 214 static int pmc_can_allocate_rowindex(struct proc *p, unsigned int ri, 215 int cpu); 216 static int pmc_can_attach(struct pmc *pm, struct proc *p); 217 static void pmc_capture_user_callchain(int cpu, int soft, struct trapframe *tf); 218 static void pmc_cleanup(void); 219 static int pmc_detach_process(struct proc *p, struct pmc *pm); 220 static int pmc_detach_one_process(struct proc *p, struct pmc *pm, 221 int flags); 222 static void pmc_destroy_owner_descriptor(struct pmc_owner *po); 223 static void pmc_destroy_pmc_descriptor(struct pmc *pm); 224 static void pmc_destroy_process_descriptor(struct pmc_process *pp); 225 static struct pmc_owner *pmc_find_owner_descriptor(struct proc *p); 226 static int pmc_find_pmc(pmc_id_t pmcid, struct pmc **pm); 227 static struct pmc *pmc_find_pmc_descriptor_in_process(struct pmc_owner *po, 228 pmc_id_t pmc); 229 static struct pmc_process *pmc_find_process_descriptor(struct proc *p, 230 uint32_t mode); 231 static struct pmc_thread *pmc_find_thread_descriptor(struct pmc_process *pp, 232 struct thread *td, uint32_t mode); 233 static void pmc_force_context_switch(void); 234 static void pmc_link_target_process(struct pmc *pm, 235 struct pmc_process *pp); 236 static void pmc_log_all_process_mappings(struct pmc_owner *po); 237 static void pmc_log_kernel_mappings(struct pmc *pm); 238 static void pmc_log_process_mappings(struct pmc_owner *po, struct proc *p); 239 static void pmc_maybe_remove_owner(struct pmc_owner *po); 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_exit(void *arg, struct proc *p); 243 static void pmc_process_fork(void *arg, struct proc *p1, 244 struct proc *p2, int n); 245 static void pmc_process_samples(int cpu, ring_type_t soft); 246 static void pmc_release_pmc_descriptor(struct pmc *pmc); 247 static void pmc_process_thread_add(struct thread *td); 248 static void pmc_process_thread_delete(struct thread *td); 249 static void pmc_process_thread_userret(struct thread *td); 250 static void pmc_remove_owner(struct pmc_owner *po); 251 static void pmc_remove_process_descriptor(struct pmc_process *pp); 252 static void pmc_restore_cpu_binding(struct pmc_binding *pb); 253 static void pmc_save_cpu_binding(struct pmc_binding *pb); 254 static void pmc_select_cpu(int cpu); 255 static int pmc_start(struct pmc *pm); 256 static int pmc_stop(struct pmc *pm); 257 static int pmc_syscall_handler(struct thread *td, void *syscall_args); 258 static struct pmc_thread *pmc_thread_descriptor_pool_alloc(void); 259 static void pmc_thread_descriptor_pool_drain(void); 260 static void pmc_thread_descriptor_pool_free(struct pmc_thread *pt); 261 static void pmc_unlink_target_process(struct pmc *pmc, 262 struct pmc_process *pp); 263 static int generic_switch_in(struct pmc_cpu *pc, struct pmc_process *pp); 264 static int generic_switch_out(struct pmc_cpu *pc, struct pmc_process *pp); 265 static struct pmc_mdep *pmc_generic_cpu_initialize(void); 266 static void pmc_generic_cpu_finalize(struct pmc_mdep *md); 267 static void pmc_post_callchain_callback(void); 268 static void pmc_process_threadcreate(struct thread *td); 269 static void pmc_process_threadexit(struct thread *td); 270 static void pmc_process_proccreate(struct proc *p); 271 static void pmc_process_allproc(struct pmc *pm); 272 273 /* 274 * Kernel tunables and sysctl(8) interface. 275 */ 276 277 SYSCTL_DECL(_kern_hwpmc); 278 SYSCTL_NODE(_kern_hwpmc, OID_AUTO, stats, CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 279 "HWPMC stats"); 280 281 282 /* Stats. */ 283 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, intr_ignored, CTLFLAG_RW, 284 &pmc_stats.pm_intr_ignored, "# of interrupts ignored"); 285 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, intr_processed, CTLFLAG_RW, 286 &pmc_stats.pm_intr_processed, "# of interrupts processed"); 287 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, intr_bufferfull, CTLFLAG_RW, 288 &pmc_stats.pm_intr_bufferfull, "# of interrupts where buffer was full"); 289 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, syscalls, CTLFLAG_RW, 290 &pmc_stats.pm_syscalls, "# of syscalls"); 291 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, syscall_errors, CTLFLAG_RW, 292 &pmc_stats.pm_syscall_errors, "# of syscall_errors"); 293 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, buffer_requests, CTLFLAG_RW, 294 &pmc_stats.pm_buffer_requests, "# of buffer requests"); 295 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, buffer_requests_failed, CTLFLAG_RW, 296 &pmc_stats.pm_buffer_requests_failed, "# of buffer requests which failed"); 297 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, log_sweeps, CTLFLAG_RW, 298 &pmc_stats.pm_log_sweeps, "# of ?"); 299 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, merges, CTLFLAG_RW, 300 &pmc_stats.pm_merges, "# of times kernel stack was found for user trace"); 301 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, overwrites, CTLFLAG_RW, 302 &pmc_stats.pm_overwrites, "# of times a sample was overwritten before being logged"); 303 304 static int pmc_callchaindepth = PMC_CALLCHAIN_DEPTH; 305 SYSCTL_INT(_kern_hwpmc, OID_AUTO, callchaindepth, CTLFLAG_RDTUN, 306 &pmc_callchaindepth, 0, "depth of call chain records"); 307 308 char pmc_cpuid[PMC_CPUID_LEN]; 309 SYSCTL_STRING(_kern_hwpmc, OID_AUTO, cpuid, CTLFLAG_RD, 310 pmc_cpuid, 0, "cpu version string"); 311 #ifdef HWPMC_DEBUG 312 struct pmc_debugflags pmc_debugflags = PMC_DEBUG_DEFAULT_FLAGS; 313 char pmc_debugstr[PMC_DEBUG_STRSIZE]; 314 TUNABLE_STR(PMC_SYSCTL_NAME_PREFIX "debugflags", pmc_debugstr, 315 sizeof(pmc_debugstr)); 316 SYSCTL_PROC(_kern_hwpmc, OID_AUTO, debugflags, 317 CTLTYPE_STRING | CTLFLAG_RWTUN | CTLFLAG_NOFETCH | CTLFLAG_NEEDGIANT, 318 0, 0, pmc_debugflags_sysctl_handler, "A", 319 "debug flags"); 320 #endif 321 322 323 /* 324 * kern.hwpmc.hashrows -- determines the number of rows in the 325 * of the hash table used to look up threads 326 */ 327 328 static int pmc_hashsize = PMC_HASH_SIZE; 329 SYSCTL_INT(_kern_hwpmc, OID_AUTO, hashsize, CTLFLAG_RDTUN, 330 &pmc_hashsize, 0, "rows in hash tables"); 331 332 /* 333 * kern.hwpmc.nsamples --- number of PC samples/callchain stacks per CPU 334 */ 335 336 static int pmc_nsamples = PMC_NSAMPLES; 337 SYSCTL_INT(_kern_hwpmc, OID_AUTO, nsamples, CTLFLAG_RDTUN, 338 &pmc_nsamples, 0, "number of PC samples per CPU"); 339 340 static uint64_t pmc_sample_mask = PMC_NSAMPLES-1; 341 342 /* 343 * kern.hwpmc.mtxpoolsize -- number of mutexes in the mutex pool. 344 */ 345 346 static int pmc_mtxpool_size = PMC_MTXPOOL_SIZE; 347 SYSCTL_INT(_kern_hwpmc, OID_AUTO, mtxpoolsize, CTLFLAG_RDTUN, 348 &pmc_mtxpool_size, 0, "size of spin mutex pool"); 349 350 351 /* 352 * kern.hwpmc.threadfreelist_entries -- number of free entries 353 */ 354 355 SYSCTL_INT(_kern_hwpmc, OID_AUTO, threadfreelist_entries, CTLFLAG_RD, 356 &pmc_threadfreelist_entries, 0, "number of avalable thread entries"); 357 358 359 /* 360 * kern.hwpmc.threadfreelist_max -- maximum number of free entries 361 */ 362 363 static int pmc_threadfreelist_max = PMC_THREADLIST_MAX; 364 SYSCTL_INT(_kern_hwpmc, OID_AUTO, threadfreelist_max, CTLFLAG_RW, 365 &pmc_threadfreelist_max, 0, 366 "maximum number of available thread entries before freeing some"); 367 368 369 /* 370 * security.bsd.unprivileged_syspmcs -- allow non-root processes to 371 * allocate system-wide PMCs. 372 * 373 * Allowing unprivileged processes to allocate system PMCs is convenient 374 * if system-wide measurements need to be taken concurrently with other 375 * per-process measurements. This feature is turned off by default. 376 */ 377 378 static int pmc_unprivileged_syspmcs = 0; 379 SYSCTL_INT(_security_bsd, OID_AUTO, unprivileged_syspmcs, CTLFLAG_RWTUN, 380 &pmc_unprivileged_syspmcs, 0, 381 "allow unprivileged process to allocate system PMCs"); 382 383 /* 384 * Hash function. Discard the lower 2 bits of the pointer since 385 * these are always zero for our uses. The hash multiplier is 386 * round((2^LONG_BIT) * ((sqrt(5)-1)/2)). 387 */ 388 389 #if LONG_BIT == 64 390 #define _PMC_HM 11400714819323198486u 391 #elif LONG_BIT == 32 392 #define _PMC_HM 2654435769u 393 #else 394 #error Must know the size of 'long' to compile 395 #endif 396 397 #define PMC_HASH_PTR(P,M) ((((unsigned long) (P) >> 2) * _PMC_HM) & (M)) 398 399 /* 400 * Syscall structures 401 */ 402 403 /* The `sysent' for the new syscall */ 404 static struct sysent pmc_sysent = { 405 .sy_narg = 2, 406 .sy_call = pmc_syscall_handler, 407 }; 408 409 static struct syscall_module_data pmc_syscall_mod = { 410 .chainevh = load, 411 .chainarg = NULL, 412 .offset = &pmc_syscall_num, 413 .new_sysent = &pmc_sysent, 414 .old_sysent = { .sy_narg = 0, .sy_call = NULL }, 415 .flags = SY_THR_STATIC_KLD, 416 }; 417 418 static moduledata_t pmc_mod = { 419 .name = PMC_MODULE_NAME, 420 .evhand = syscall_module_handler, 421 .priv = &pmc_syscall_mod, 422 }; 423 424 #ifdef EARLY_AP_STARTUP 425 DECLARE_MODULE(pmc, pmc_mod, SI_SUB_SYSCALLS, SI_ORDER_ANY); 426 #else 427 DECLARE_MODULE(pmc, pmc_mod, SI_SUB_SMP, SI_ORDER_ANY); 428 #endif 429 MODULE_VERSION(pmc, PMC_VERSION); 430 431 #ifdef HWPMC_DEBUG 432 enum pmc_dbgparse_state { 433 PMCDS_WS, /* in whitespace */ 434 PMCDS_MAJOR, /* seen a major keyword */ 435 PMCDS_MINOR 436 }; 437 438 static int 439 pmc_debugflags_parse(char *newstr, char *fence) 440 { 441 char c, *p, *q; 442 struct pmc_debugflags *tmpflags; 443 int error, found, *newbits, tmp; 444 size_t kwlen; 445 446 tmpflags = malloc(sizeof(*tmpflags), M_PMC, M_WAITOK|M_ZERO); 447 448 p = newstr; 449 error = 0; 450 451 for (; p < fence && (c = *p); p++) { 452 453 /* skip white space */ 454 if (c == ' ' || c == '\t') 455 continue; 456 457 /* look for a keyword followed by "=" */ 458 for (q = p; p < fence && (c = *p) && c != '='; p++) 459 ; 460 if (c != '=') { 461 error = EINVAL; 462 goto done; 463 } 464 465 kwlen = p - q; 466 newbits = NULL; 467 468 /* lookup flag group name */ 469 #define DBG_SET_FLAG_MAJ(S,F) \ 470 if (kwlen == sizeof(S)-1 && strncmp(q, S, kwlen) == 0) \ 471 newbits = &tmpflags->pdb_ ## F; 472 473 DBG_SET_FLAG_MAJ("cpu", CPU); 474 DBG_SET_FLAG_MAJ("csw", CSW); 475 DBG_SET_FLAG_MAJ("logging", LOG); 476 DBG_SET_FLAG_MAJ("module", MOD); 477 DBG_SET_FLAG_MAJ("md", MDP); 478 DBG_SET_FLAG_MAJ("owner", OWN); 479 DBG_SET_FLAG_MAJ("pmc", PMC); 480 DBG_SET_FLAG_MAJ("process", PRC); 481 DBG_SET_FLAG_MAJ("sampling", SAM); 482 483 if (newbits == NULL) { 484 error = EINVAL; 485 goto done; 486 } 487 488 p++; /* skip the '=' */ 489 490 /* Now parse the individual flags */ 491 tmp = 0; 492 newflag: 493 for (q = p; p < fence && (c = *p); p++) 494 if (c == ' ' || c == '\t' || c == ',') 495 break; 496 497 /* p == fence or c == ws or c == "," or c == 0 */ 498 499 if ((kwlen = p - q) == 0) { 500 *newbits = tmp; 501 continue; 502 } 503 504 found = 0; 505 #define DBG_SET_FLAG_MIN(S,F) \ 506 if (kwlen == sizeof(S)-1 && strncmp(q, S, kwlen) == 0) \ 507 tmp |= found = (1 << PMC_DEBUG_MIN_ ## F) 508 509 /* a '*' denotes all possible flags in the group */ 510 if (kwlen == 1 && *q == '*') 511 tmp = found = ~0; 512 /* look for individual flag names */ 513 DBG_SET_FLAG_MIN("allocaterow", ALR); 514 DBG_SET_FLAG_MIN("allocate", ALL); 515 DBG_SET_FLAG_MIN("attach", ATT); 516 DBG_SET_FLAG_MIN("bind", BND); 517 DBG_SET_FLAG_MIN("config", CFG); 518 DBG_SET_FLAG_MIN("exec", EXC); 519 DBG_SET_FLAG_MIN("exit", EXT); 520 DBG_SET_FLAG_MIN("find", FND); 521 DBG_SET_FLAG_MIN("flush", FLS); 522 DBG_SET_FLAG_MIN("fork", FRK); 523 DBG_SET_FLAG_MIN("getbuf", GTB); 524 DBG_SET_FLAG_MIN("hook", PMH); 525 DBG_SET_FLAG_MIN("init", INI); 526 DBG_SET_FLAG_MIN("intr", INT); 527 DBG_SET_FLAG_MIN("linktarget", TLK); 528 DBG_SET_FLAG_MIN("mayberemove", OMR); 529 DBG_SET_FLAG_MIN("ops", OPS); 530 DBG_SET_FLAG_MIN("read", REA); 531 DBG_SET_FLAG_MIN("register", REG); 532 DBG_SET_FLAG_MIN("release", REL); 533 DBG_SET_FLAG_MIN("remove", ORM); 534 DBG_SET_FLAG_MIN("sample", SAM); 535 DBG_SET_FLAG_MIN("scheduleio", SIO); 536 DBG_SET_FLAG_MIN("select", SEL); 537 DBG_SET_FLAG_MIN("signal", SIG); 538 DBG_SET_FLAG_MIN("swi", SWI); 539 DBG_SET_FLAG_MIN("swo", SWO); 540 DBG_SET_FLAG_MIN("start", STA); 541 DBG_SET_FLAG_MIN("stop", STO); 542 DBG_SET_FLAG_MIN("syscall", PMS); 543 DBG_SET_FLAG_MIN("unlinktarget", TUL); 544 DBG_SET_FLAG_MIN("write", WRI); 545 if (found == 0) { 546 /* unrecognized flag name */ 547 error = EINVAL; 548 goto done; 549 } 550 551 if (c == 0 || c == ' ' || c == '\t') { /* end of flag group */ 552 *newbits = tmp; 553 continue; 554 } 555 556 p++; 557 goto newflag; 558 } 559 560 /* save the new flag set */ 561 bcopy(tmpflags, &pmc_debugflags, sizeof(pmc_debugflags)); 562 563 done: 564 free(tmpflags, M_PMC); 565 return error; 566 } 567 568 static int 569 pmc_debugflags_sysctl_handler(SYSCTL_HANDLER_ARGS) 570 { 571 char *fence, *newstr; 572 int error; 573 unsigned int n; 574 575 (void) arg1; (void) arg2; /* unused parameters */ 576 577 n = sizeof(pmc_debugstr); 578 newstr = malloc(n, M_PMC, M_WAITOK|M_ZERO); 579 (void) strlcpy(newstr, pmc_debugstr, n); 580 581 error = sysctl_handle_string(oidp, newstr, n, req); 582 583 /* if there is a new string, parse and copy it */ 584 if (error == 0 && req->newptr != NULL) { 585 fence = newstr + (n < req->newlen ? n : req->newlen + 1); 586 if ((error = pmc_debugflags_parse(newstr, fence)) == 0) 587 (void) strlcpy(pmc_debugstr, newstr, 588 sizeof(pmc_debugstr)); 589 } 590 591 free(newstr, M_PMC); 592 593 return error; 594 } 595 #endif 596 597 /* 598 * Map a row index to a classdep structure and return the adjusted row 599 * index for the PMC class index. 600 */ 601 static struct pmc_classdep * 602 pmc_ri_to_classdep(struct pmc_mdep *md, int ri, int *adjri) 603 { 604 struct pmc_classdep *pcd; 605 606 (void) md; 607 608 KASSERT(ri >= 0 && ri < md->pmd_npmc, 609 ("[pmc,%d] illegal row-index %d", __LINE__, ri)); 610 611 pcd = pmc_rowindex_to_classdep[ri]; 612 613 KASSERT(pcd != NULL, 614 ("[pmc,%d] ri %d null pcd", __LINE__, ri)); 615 616 *adjri = ri - pcd->pcd_ri; 617 618 KASSERT(*adjri >= 0 && *adjri < pcd->pcd_num, 619 ("[pmc,%d] adjusted row-index %d", __LINE__, *adjri)); 620 621 return (pcd); 622 } 623 624 /* 625 * Concurrency Control 626 * 627 * The driver manages the following data structures: 628 * 629 * - target process descriptors, one per target process 630 * - owner process descriptors (and attached lists), one per owner process 631 * - lookup hash tables for owner and target processes 632 * - PMC descriptors (and attached lists) 633 * - per-cpu hardware state 634 * - the 'hook' variable through which the kernel calls into 635 * this module 636 * - the machine hardware state (managed by the MD layer) 637 * 638 * These data structures are accessed from: 639 * 640 * - thread context-switch code 641 * - interrupt handlers (possibly on multiple cpus) 642 * - kernel threads on multiple cpus running on behalf of user 643 * processes doing system calls 644 * - this driver's private kernel threads 645 * 646 * = Locks and Locking strategy = 647 * 648 * The driver uses four locking strategies for its operation: 649 * 650 * - The global SX lock "pmc_sx" is used to protect internal 651 * data structures. 652 * 653 * Calls into the module by syscall() start with this lock being 654 * held in exclusive mode. Depending on the requested operation, 655 * the lock may be downgraded to 'shared' mode to allow more 656 * concurrent readers into the module. Calls into the module from 657 * other parts of the kernel acquire the lock in shared mode. 658 * 659 * This SX lock is held in exclusive mode for any operations that 660 * modify the linkages between the driver's internal data structures. 661 * 662 * The 'pmc_hook' function pointer is also protected by this lock. 663 * It is only examined with the sx lock held in exclusive mode. The 664 * kernel module is allowed to be unloaded only with the sx lock held 665 * in exclusive mode. In normal syscall handling, after acquiring the 666 * pmc_sx lock we first check that 'pmc_hook' is non-null before 667 * proceeding. This prevents races between the thread unloading the module 668 * and other threads seeking to use the module. 669 * 670 * - Lookups of target process structures and owner process structures 671 * cannot use the global "pmc_sx" SX lock because these lookups need 672 * to happen during context switches and in other critical sections 673 * where sleeping is not allowed. We protect these lookup tables 674 * with their own private spin-mutexes, "pmc_processhash_mtx" and 675 * "pmc_ownerhash_mtx". 676 * 677 * - Interrupt handlers work in a lock free manner. At interrupt 678 * time, handlers look at the PMC pointer (phw->phw_pmc) configured 679 * when the PMC was started. If this pointer is NULL, the interrupt 680 * is ignored after updating driver statistics. We ensure that this 681 * pointer is set (using an atomic operation if necessary) before the 682 * PMC hardware is started. Conversely, this pointer is unset atomically 683 * only after the PMC hardware is stopped. 684 * 685 * We ensure that everything needed for the operation of an 686 * interrupt handler is available without it needing to acquire any 687 * locks. We also ensure that a PMC's software state is destroyed only 688 * after the PMC is taken off hardware (on all CPUs). 689 * 690 * - Context-switch handling with process-private PMCs needs more 691 * care. 692 * 693 * A given process may be the target of multiple PMCs. For example, 694 * PMCATTACH and PMCDETACH may be requested by a process on one CPU 695 * while the target process is running on another. A PMC could also 696 * be getting released because its owner is exiting. We tackle 697 * these situations in the following manner: 698 * 699 * - each target process structure 'pmc_process' has an array 700 * of 'struct pmc *' pointers, one for each hardware PMC. 701 * 702 * - At context switch IN time, each "target" PMC in RUNNING state 703 * gets started on hardware and a pointer to each PMC is copied into 704 * the per-cpu phw array. The 'runcount' for the PMC is 705 * incremented. 706 * 707 * - At context switch OUT time, all process-virtual PMCs are stopped 708 * on hardware. The saved value is added to the PMCs value field 709 * only if the PMC is in a non-deleted state (the PMCs state could 710 * have changed during the current time slice). 711 * 712 * Note that since in-between a switch IN on a processor and a switch 713 * OUT, the PMC could have been released on another CPU. Therefore 714 * context switch OUT always looks at the hardware state to turn 715 * OFF PMCs and will update a PMC's saved value only if reachable 716 * from the target process record. 717 * 718 * - OP PMCRELEASE could be called on a PMC at any time (the PMC could 719 * be attached to many processes at the time of the call and could 720 * be active on multiple CPUs). 721 * 722 * We prevent further scheduling of the PMC by marking it as in 723 * state 'DELETED'. If the runcount of the PMC is non-zero then 724 * this PMC is currently running on a CPU somewhere. The thread 725 * doing the PMCRELEASE operation waits by repeatedly doing a 726 * pause() till the runcount comes to zero. 727 * 728 * The contents of a PMC descriptor (struct pmc) are protected using 729 * a spin-mutex. In order to save space, we use a mutex pool. 730 * 731 * In terms of lock types used by witness(4), we use: 732 * - Type "pmc-sx", used by the global SX lock. 733 * - Type "pmc-sleep", for sleep mutexes used by logger threads. 734 * - Type "pmc-per-proc", for protecting PMC owner descriptors. 735 * - Type "pmc-leaf", used for all other spin mutexes. 736 */ 737 738 /* 739 * save the cpu binding of the current kthread 740 */ 741 742 static void 743 pmc_save_cpu_binding(struct pmc_binding *pb) 744 { 745 PMCDBG0(CPU,BND,2, "save-cpu"); 746 thread_lock(curthread); 747 pb->pb_bound = sched_is_bound(curthread); 748 pb->pb_cpu = curthread->td_oncpu; 749 thread_unlock(curthread); 750 PMCDBG1(CPU,BND,2, "save-cpu cpu=%d", pb->pb_cpu); 751 } 752 753 /* 754 * restore the cpu binding of the current thread 755 */ 756 757 static void 758 pmc_restore_cpu_binding(struct pmc_binding *pb) 759 { 760 PMCDBG2(CPU,BND,2, "restore-cpu curcpu=%d restore=%d", 761 curthread->td_oncpu, pb->pb_cpu); 762 thread_lock(curthread); 763 if (pb->pb_bound) 764 sched_bind(curthread, pb->pb_cpu); 765 else 766 sched_unbind(curthread); 767 thread_unlock(curthread); 768 PMCDBG0(CPU,BND,2, "restore-cpu done"); 769 } 770 771 /* 772 * move execution over the specified cpu and bind it there. 773 */ 774 775 static void 776 pmc_select_cpu(int cpu) 777 { 778 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 779 ("[pmc,%d] bad cpu number %d", __LINE__, cpu)); 780 781 /* Never move to an inactive CPU. */ 782 KASSERT(pmc_cpu_is_active(cpu), ("[pmc,%d] selecting inactive " 783 "CPU %d", __LINE__, cpu)); 784 785 PMCDBG1(CPU,SEL,2, "select-cpu cpu=%d", cpu); 786 thread_lock(curthread); 787 sched_bind(curthread, cpu); 788 thread_unlock(curthread); 789 790 KASSERT(curthread->td_oncpu == cpu, 791 ("[pmc,%d] CPU not bound [cpu=%d, curr=%d]", __LINE__, 792 cpu, curthread->td_oncpu)); 793 794 PMCDBG1(CPU,SEL,2, "select-cpu cpu=%d ok", cpu); 795 } 796 797 /* 798 * Force a context switch. 799 * 800 * We do this by pause'ing for 1 tick -- invoking mi_switch() is not 801 * guaranteed to force a context switch. 802 */ 803 804 static void 805 pmc_force_context_switch(void) 806 { 807 808 pause("pmcctx", 1); 809 } 810 811 uint64_t 812 pmc_rdtsc(void) 813 { 814 #if defined(__i386__) || defined(__amd64__) 815 if (__predict_true(amd_feature & AMDID_RDTSCP)) 816 return rdtscp(); 817 else 818 return rdtsc(); 819 #else 820 return get_cyclecount(); 821 #endif 822 } 823 824 /* 825 * Get the file name for an executable. This is a simple wrapper 826 * around vn_fullpath(9). 827 */ 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 an process owning PMCs 840 */ 841 842 void 843 pmc_remove_owner(struct pmc_owner *po) 844 { 845 struct pmc *pm, *tmp; 846 847 sx_assert(&pmc_sx, SX_XLOCKED); 848 849 PMCDBG1(OWN,ORM,1, "remove-owner po=%p", po); 850 851 /* Remove descriptor from the owner hash table */ 852 LIST_REMOVE(po, po_next); 853 854 /* release all owned PMC descriptors */ 855 LIST_FOREACH_SAFE(pm, &po->po_pmcs, pm_next, tmp) { 856 PMCDBG1(OWN,ORM,2, "pmc=%p", pm); 857 KASSERT(pm->pm_owner == po, 858 ("[pmc,%d] owner %p != po %p", __LINE__, pm->pm_owner, po)); 859 860 pmc_release_pmc_descriptor(pm); /* will unlink from the list */ 861 pmc_destroy_pmc_descriptor(pm); 862 } 863 864 KASSERT(po->po_sscount == 0, 865 ("[pmc,%d] SS count not zero", __LINE__)); 866 KASSERT(LIST_EMPTY(&po->po_pmcs), 867 ("[pmc,%d] PMC list not empty", __LINE__)); 868 869 /* de-configure the log file if present */ 870 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 871 pmclog_deconfigure_log(po); 872 } 873 874 /* 875 * remove an owner process record if all conditions are met. 876 */ 877 878 static void 879 pmc_maybe_remove_owner(struct pmc_owner *po) 880 { 881 882 PMCDBG1(OWN,OMR,1, "maybe-remove-owner po=%p", po); 883 884 /* 885 * Remove owner record if 886 * - this process does not own any PMCs 887 * - this process has not allocated a system-wide sampling buffer 888 */ 889 890 if (LIST_EMPTY(&po->po_pmcs) && 891 ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0)) { 892 pmc_remove_owner(po); 893 pmc_destroy_owner_descriptor(po); 894 } 895 } 896 897 /* 898 * Add an association between a target process and a PMC. 899 */ 900 901 static void 902 pmc_link_target_process(struct pmc *pm, struct pmc_process *pp) 903 { 904 int ri; 905 struct pmc_target *pt; 906 #ifdef INVARIANTS 907 struct pmc_thread *pt_td; 908 #endif 909 910 sx_assert(&pmc_sx, SX_XLOCKED); 911 912 KASSERT(pm != NULL && pp != NULL, 913 ("[pmc,%d] Null pm %p or pp %p", __LINE__, pm, pp)); 914 KASSERT(PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)), 915 ("[pmc,%d] Attaching a non-process-virtual pmc=%p to pid=%d", 916 __LINE__, pm, pp->pp_proc->p_pid)); 917 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= ((int) md->pmd_npmc - 1), 918 ("[pmc,%d] Illegal reference count %d for process record %p", 919 __LINE__, pp->pp_refcnt, (void *) pp)); 920 921 ri = PMC_TO_ROWINDEX(pm); 922 923 PMCDBG3(PRC,TLK,1, "link-target pmc=%p ri=%d pmc-process=%p", 924 pm, ri, pp); 925 926 #ifdef HWPMC_DEBUG 927 LIST_FOREACH(pt, &pm->pm_targets, pt_next) 928 if (pt->pt_process == pp) 929 KASSERT(0, ("[pmc,%d] pp %p already in pmc %p targets", 930 __LINE__, pp, pm)); 931 #endif 932 933 pt = malloc(sizeof(struct pmc_target), M_PMC, M_WAITOK|M_ZERO); 934 pt->pt_process = pp; 935 936 LIST_INSERT_HEAD(&pm->pm_targets, pt, pt_next); 937 938 atomic_store_rel_ptr((uintptr_t *)&pp->pp_pmcs[ri].pp_pmc, 939 (uintptr_t)pm); 940 941 if (pm->pm_owner->po_owner == pp->pp_proc) 942 pm->pm_flags |= PMC_F_ATTACHED_TO_OWNER; 943 944 /* 945 * Initialize the per-process values at this row index. 946 */ 947 pp->pp_pmcs[ri].pp_pmcval = PMC_TO_MODE(pm) == PMC_MODE_TS ? 948 pm->pm_sc.pm_reloadcount : 0; 949 950 pp->pp_refcnt++; 951 952 #ifdef INVARIANTS 953 /* Confirm that the per-thread values at this row index are cleared. */ 954 if (PMC_TO_MODE(pm) == PMC_MODE_TS) { 955 mtx_lock_spin(pp->pp_tdslock); 956 LIST_FOREACH(pt_td, &pp->pp_tds, pt_next) { 957 KASSERT(pt_td->pt_pmcs[ri].pt_pmcval == (pmc_value_t) 0, 958 ("[pmc,%d] pt_pmcval not cleared for pid=%d at " 959 "ri=%d", __LINE__, pp->pp_proc->p_pid, ri)); 960 } 961 mtx_unlock_spin(pp->pp_tdslock); 962 } 963 #endif 964 } 965 966 /* 967 * Removes the association between a target process and a PMC. 968 */ 969 970 static void 971 pmc_unlink_target_process(struct pmc *pm, struct pmc_process *pp) 972 { 973 int ri; 974 struct proc *p; 975 struct pmc_target *ptgt; 976 struct pmc_thread *pt; 977 978 sx_assert(&pmc_sx, SX_XLOCKED); 979 980 KASSERT(pm != NULL && pp != NULL, 981 ("[pmc,%d] Null pm %p or pp %p", __LINE__, pm, pp)); 982 983 KASSERT(pp->pp_refcnt >= 1 && pp->pp_refcnt <= (int) md->pmd_npmc, 984 ("[pmc,%d] Illegal ref count %d on process record %p", 985 __LINE__, pp->pp_refcnt, (void *) pp)); 986 987 ri = PMC_TO_ROWINDEX(pm); 988 989 PMCDBG3(PRC,TUL,1, "unlink-target pmc=%p ri=%d pmc-process=%p", 990 pm, ri, pp); 991 992 KASSERT(pp->pp_pmcs[ri].pp_pmc == pm, 993 ("[pmc,%d] PMC ri %d mismatch pmc %p pp->[ri] %p", __LINE__, 994 ri, pm, pp->pp_pmcs[ri].pp_pmc)); 995 996 pp->pp_pmcs[ri].pp_pmc = NULL; 997 pp->pp_pmcs[ri].pp_pmcval = (pmc_value_t) 0; 998 999 /* Clear the per-thread values at this row index. */ 1000 if (PMC_TO_MODE(pm) == PMC_MODE_TS) { 1001 mtx_lock_spin(pp->pp_tdslock); 1002 LIST_FOREACH(pt, &pp->pp_tds, pt_next) 1003 pt->pt_pmcs[ri].pt_pmcval = (pmc_value_t) 0; 1004 mtx_unlock_spin(pp->pp_tdslock); 1005 } 1006 1007 /* Remove owner-specific flags */ 1008 if (pm->pm_owner->po_owner == pp->pp_proc) { 1009 pp->pp_flags &= ~PMC_PP_ENABLE_MSR_ACCESS; 1010 pm->pm_flags &= ~PMC_F_ATTACHED_TO_OWNER; 1011 } 1012 1013 pp->pp_refcnt--; 1014 1015 /* Remove the target process from the PMC structure */ 1016 LIST_FOREACH(ptgt, &pm->pm_targets, pt_next) 1017 if (ptgt->pt_process == pp) 1018 break; 1019 1020 KASSERT(ptgt != NULL, ("[pmc,%d] process %p (pp: %p) not found " 1021 "in pmc %p", __LINE__, pp->pp_proc, pp, pm)); 1022 1023 LIST_REMOVE(ptgt, pt_next); 1024 free(ptgt, M_PMC); 1025 1026 /* if the PMC now lacks targets, send the owner a SIGIO */ 1027 if (LIST_EMPTY(&pm->pm_targets)) { 1028 p = pm->pm_owner->po_owner; 1029 PROC_LOCK(p); 1030 kern_psignal(p, SIGIO); 1031 PROC_UNLOCK(p); 1032 1033 PMCDBG2(PRC,SIG,2, "signalling proc=%p signal=%d", p, 1034 SIGIO); 1035 } 1036 } 1037 1038 /* 1039 * Check if PMC 'pm' may be attached to target process 't'. 1040 */ 1041 1042 static int 1043 pmc_can_attach(struct pmc *pm, struct proc *t) 1044 { 1045 struct proc *o; /* pmc owner */ 1046 struct ucred *oc, *tc; /* owner, target credentials */ 1047 int decline_attach, i; 1048 1049 /* 1050 * A PMC's owner can always attach that PMC to itself. 1051 */ 1052 1053 if ((o = pm->pm_owner->po_owner) == t) 1054 return 0; 1055 1056 PROC_LOCK(o); 1057 oc = o->p_ucred; 1058 crhold(oc); 1059 PROC_UNLOCK(o); 1060 1061 PROC_LOCK(t); 1062 tc = t->p_ucred; 1063 crhold(tc); 1064 PROC_UNLOCK(t); 1065 1066 /* 1067 * The effective uid of the PMC owner should match at least one 1068 * of the {effective,real,saved} uids of the target process. 1069 */ 1070 1071 decline_attach = oc->cr_uid != tc->cr_uid && 1072 oc->cr_uid != tc->cr_svuid && 1073 oc->cr_uid != tc->cr_ruid; 1074 1075 /* 1076 * Every one of the target's group ids, must be in the owner's 1077 * group list. 1078 */ 1079 for (i = 0; !decline_attach && i < tc->cr_ngroups; i++) 1080 decline_attach = !groupmember(tc->cr_groups[i], oc); 1081 1082 /* check the read and saved gids too */ 1083 if (decline_attach == 0) 1084 decline_attach = !groupmember(tc->cr_rgid, oc) || 1085 !groupmember(tc->cr_svgid, oc); 1086 1087 crfree(tc); 1088 crfree(oc); 1089 1090 return !decline_attach; 1091 } 1092 1093 /* 1094 * Attach a process to a PMC. 1095 */ 1096 1097 static int 1098 pmc_attach_one_process(struct proc *p, struct pmc *pm) 1099 { 1100 int ri, error; 1101 char *fullpath, *freepath; 1102 struct pmc_process *pp; 1103 1104 sx_assert(&pmc_sx, SX_XLOCKED); 1105 1106 PMCDBG5(PRC,ATT,2, "attach-one pm=%p ri=%d proc=%p (%d, %s)", pm, 1107 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 1108 1109 /* 1110 * Locate the process descriptor corresponding to process 'p', 1111 * allocating space as needed. 1112 * 1113 * Verify that rowindex 'pm_rowindex' is free in the process 1114 * descriptor. 1115 * 1116 * If not, allocate space for a descriptor and link the 1117 * process descriptor and PMC. 1118 */ 1119 ri = PMC_TO_ROWINDEX(pm); 1120 1121 /* mark process as using HWPMCs */ 1122 PROC_LOCK(p); 1123 p->p_flag |= P_HWPMC; 1124 PROC_UNLOCK(p); 1125 1126 if ((pp = pmc_find_process_descriptor(p, PMC_FLAG_ALLOCATE)) == NULL) { 1127 error = ENOMEM; 1128 goto fail; 1129 } 1130 1131 if (pp->pp_pmcs[ri].pp_pmc == pm) {/* already present at slot [ri] */ 1132 error = EEXIST; 1133 goto fail; 1134 } 1135 1136 if (pp->pp_pmcs[ri].pp_pmc != NULL) { 1137 error = EBUSY; 1138 goto fail; 1139 } 1140 1141 pmc_link_target_process(pm, pp); 1142 1143 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)) && 1144 (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) == 0) 1145 pm->pm_flags |= PMC_F_NEEDS_LOGFILE; 1146 1147 pm->pm_flags |= PMC_F_ATTACH_DONE; /* mark as attached */ 1148 1149 /* issue an attach event to a configured log file */ 1150 if (pm->pm_owner->po_flags & PMC_PO_OWNS_LOGFILE) { 1151 if (p->p_flag & P_KPROC) { 1152 fullpath = kernelname; 1153 freepath = NULL; 1154 } else { 1155 pmc_getfilename(p->p_textvp, &fullpath, &freepath); 1156 pmclog_process_pmcattach(pm, p->p_pid, fullpath); 1157 } 1158 free(freepath, M_TEMP); 1159 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 1160 pmc_log_process_mappings(pm->pm_owner, p); 1161 } 1162 1163 return (0); 1164 fail: 1165 PROC_LOCK(p); 1166 p->p_flag &= ~P_HWPMC; 1167 PROC_UNLOCK(p); 1168 return (error); 1169 } 1170 1171 /* 1172 * Attach a process and optionally its children 1173 */ 1174 1175 static int 1176 pmc_attach_process(struct proc *p, struct pmc *pm) 1177 { 1178 int error; 1179 struct proc *top; 1180 1181 sx_assert(&pmc_sx, SX_XLOCKED); 1182 1183 PMCDBG5(PRC,ATT,1, "attach pm=%p ri=%d proc=%p (%d, %s)", pm, 1184 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 1185 1186 1187 /* 1188 * If this PMC successfully allowed a GETMSR operation 1189 * in the past, disallow further ATTACHes. 1190 */ 1191 1192 if ((pm->pm_flags & PMC_PP_ENABLE_MSR_ACCESS) != 0) 1193 return EPERM; 1194 1195 if ((pm->pm_flags & PMC_F_DESCENDANTS) == 0) 1196 return pmc_attach_one_process(p, pm); 1197 1198 /* 1199 * Traverse all child processes, attaching them to 1200 * this PMC. 1201 */ 1202 1203 sx_slock(&proctree_lock); 1204 1205 top = p; 1206 1207 for (;;) { 1208 if ((error = pmc_attach_one_process(p, pm)) != 0) 1209 break; 1210 if (!LIST_EMPTY(&p->p_children)) 1211 p = LIST_FIRST(&p->p_children); 1212 else for (;;) { 1213 if (p == top) 1214 goto done; 1215 if (LIST_NEXT(p, p_sibling)) { 1216 p = LIST_NEXT(p, p_sibling); 1217 break; 1218 } 1219 p = p->p_pptr; 1220 } 1221 } 1222 1223 if (error) 1224 (void) pmc_detach_process(top, pm); 1225 1226 done: 1227 sx_sunlock(&proctree_lock); 1228 return error; 1229 } 1230 1231 /* 1232 * Detach a process from a PMC. If there are no other PMCs tracking 1233 * this process, remove the process structure from its hash table. If 1234 * 'flags' contains PMC_FLAG_REMOVE, then free the process structure. 1235 */ 1236 1237 static int 1238 pmc_detach_one_process(struct proc *p, struct pmc *pm, int flags) 1239 { 1240 int ri; 1241 struct pmc_process *pp; 1242 1243 sx_assert(&pmc_sx, SX_XLOCKED); 1244 1245 KASSERT(pm != NULL, 1246 ("[pmc,%d] null pm pointer", __LINE__)); 1247 1248 ri = PMC_TO_ROWINDEX(pm); 1249 1250 PMCDBG6(PRC,ATT,2, "detach-one pm=%p ri=%d proc=%p (%d, %s) flags=0x%x", 1251 pm, ri, p, p->p_pid, p->p_comm, flags); 1252 1253 if ((pp = pmc_find_process_descriptor(p, 0)) == NULL) 1254 return ESRCH; 1255 1256 if (pp->pp_pmcs[ri].pp_pmc != pm) 1257 return EINVAL; 1258 1259 pmc_unlink_target_process(pm, pp); 1260 1261 /* Issue a detach entry if a log file is configured */ 1262 if (pm->pm_owner->po_flags & PMC_PO_OWNS_LOGFILE) 1263 pmclog_process_pmcdetach(pm, p->p_pid); 1264 1265 /* 1266 * If there are no PMCs targeting this process, we remove its 1267 * descriptor from the target hash table and unset the P_HWPMC 1268 * flag in the struct proc. 1269 */ 1270 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= (int) md->pmd_npmc, 1271 ("[pmc,%d] Illegal refcnt %d for process struct %p", 1272 __LINE__, pp->pp_refcnt, pp)); 1273 1274 if (pp->pp_refcnt != 0) /* still a target of some PMC */ 1275 return 0; 1276 1277 pmc_remove_process_descriptor(pp); 1278 1279 if (flags & PMC_FLAG_REMOVE) 1280 pmc_destroy_process_descriptor(pp); 1281 1282 PROC_LOCK(p); 1283 p->p_flag &= ~P_HWPMC; 1284 PROC_UNLOCK(p); 1285 1286 return 0; 1287 } 1288 1289 /* 1290 * Detach a process and optionally its descendants from a PMC. 1291 */ 1292 1293 static int 1294 pmc_detach_process(struct proc *p, struct pmc *pm) 1295 { 1296 struct proc *top; 1297 1298 sx_assert(&pmc_sx, SX_XLOCKED); 1299 1300 PMCDBG5(PRC,ATT,1, "detach pm=%p ri=%d proc=%p (%d, %s)", pm, 1301 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 1302 1303 if ((pm->pm_flags & PMC_F_DESCENDANTS) == 0) 1304 return pmc_detach_one_process(p, pm, PMC_FLAG_REMOVE); 1305 1306 /* 1307 * Traverse all children, detaching them from this PMC. We 1308 * ignore errors since we could be detaching a PMC from a 1309 * partially attached proc tree. 1310 */ 1311 1312 sx_slock(&proctree_lock); 1313 1314 top = p; 1315 1316 for (;;) { 1317 (void) pmc_detach_one_process(p, pm, PMC_FLAG_REMOVE); 1318 1319 if (!LIST_EMPTY(&p->p_children)) 1320 p = LIST_FIRST(&p->p_children); 1321 else for (;;) { 1322 if (p == top) 1323 goto done; 1324 if (LIST_NEXT(p, p_sibling)) { 1325 p = LIST_NEXT(p, p_sibling); 1326 break; 1327 } 1328 p = p->p_pptr; 1329 } 1330 } 1331 1332 done: 1333 sx_sunlock(&proctree_lock); 1334 1335 if (LIST_EMPTY(&pm->pm_targets)) 1336 pm->pm_flags &= ~PMC_F_ATTACH_DONE; 1337 1338 return 0; 1339 } 1340 1341 1342 /* 1343 * Thread context switch IN 1344 */ 1345 1346 static void 1347 pmc_process_csw_in(struct thread *td) 1348 { 1349 int cpu; 1350 unsigned int adjri, ri; 1351 struct pmc *pm; 1352 struct proc *p; 1353 struct pmc_cpu *pc; 1354 struct pmc_hw *phw; 1355 pmc_value_t newvalue; 1356 struct pmc_process *pp; 1357 struct pmc_thread *pt; 1358 struct pmc_classdep *pcd; 1359 1360 p = td->td_proc; 1361 pt = NULL; 1362 if ((pp = pmc_find_process_descriptor(p, PMC_FLAG_NONE)) == NULL) 1363 return; 1364 1365 KASSERT(pp->pp_proc == td->td_proc, 1366 ("[pmc,%d] not my thread state", __LINE__)); 1367 1368 critical_enter(); /* no preemption from this point */ 1369 1370 cpu = PCPU_GET(cpuid); /* td->td_oncpu is invalid */ 1371 1372 PMCDBG5(CSW,SWI,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p, 1373 p->p_pid, p->p_comm, pp); 1374 1375 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 1376 ("[pmc,%d] weird CPU id %d", __LINE__, cpu)); 1377 1378 pc = pmc_pcpu[cpu]; 1379 1380 for (ri = 0; ri < md->pmd_npmc; ri++) { 1381 1382 if ((pm = pp->pp_pmcs[ri].pp_pmc) == NULL) 1383 continue; 1384 1385 KASSERT(PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)), 1386 ("[pmc,%d] Target PMC in non-virtual mode (%d)", 1387 __LINE__, PMC_TO_MODE(pm))); 1388 1389 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 1390 ("[pmc,%d] Row index mismatch pmc %d != ri %d", 1391 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 1392 1393 /* 1394 * Only PMCs that are marked as 'RUNNING' need 1395 * be placed on hardware. 1396 */ 1397 1398 if (pm->pm_state != PMC_STATE_RUNNING) 1399 continue; 1400 1401 KASSERT(counter_u64_fetch(pm->pm_runcount) >= 0, 1402 ("[pmc,%d] pm=%p runcount %ld", __LINE__, (void *) pm, 1403 (unsigned long)counter_u64_fetch(pm->pm_runcount))); 1404 1405 /* increment PMC runcount */ 1406 counter_u64_add(pm->pm_runcount, 1); 1407 1408 /* configure the HWPMC we are going to use. */ 1409 pcd = pmc_ri_to_classdep(md, ri, &adjri); 1410 pcd->pcd_config_pmc(cpu, adjri, pm); 1411 1412 phw = pc->pc_hwpmcs[ri]; 1413 1414 KASSERT(phw != NULL, 1415 ("[pmc,%d] null hw pointer", __LINE__)); 1416 1417 KASSERT(phw->phw_pmc == pm, 1418 ("[pmc,%d] hw->pmc %p != pmc %p", __LINE__, 1419 phw->phw_pmc, pm)); 1420 1421 /* 1422 * Write out saved value and start the PMC. 1423 * 1424 * Sampling PMCs use a per-thread value, while 1425 * counting mode PMCs use a per-pmc value that is 1426 * inherited across descendants. 1427 */ 1428 if (PMC_TO_MODE(pm) == PMC_MODE_TS) { 1429 if (pt == NULL) 1430 pt = pmc_find_thread_descriptor(pp, td, 1431 PMC_FLAG_NONE); 1432 1433 KASSERT(pt != NULL, 1434 ("[pmc,%d] No thread found for td=%p", __LINE__, 1435 td)); 1436 1437 mtx_pool_lock_spin(pmc_mtxpool, pm); 1438 1439 /* 1440 * If we have a thread descriptor, use the per-thread 1441 * counter in the descriptor. If not, we will use 1442 * a per-process counter. 1443 * 1444 * TODO: Remove the per-process "safety net" once 1445 * we have thoroughly tested that we don't hit the 1446 * above assert. 1447 */ 1448 if (pt != NULL) { 1449 if (pt->pt_pmcs[ri].pt_pmcval > 0) 1450 newvalue = pt->pt_pmcs[ri].pt_pmcval; 1451 else 1452 newvalue = pm->pm_sc.pm_reloadcount; 1453 } else { 1454 /* 1455 * Use the saved value calculated after the most 1456 * recent time a thread using the shared counter 1457 * switched out. Reset the saved count in case 1458 * another thread from this process switches in 1459 * before any threads switch out. 1460 */ 1461 1462 newvalue = pp->pp_pmcs[ri].pp_pmcval; 1463 pp->pp_pmcs[ri].pp_pmcval = 1464 pm->pm_sc.pm_reloadcount; 1465 } 1466 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1467 KASSERT(newvalue > 0 && newvalue <= 1468 pm->pm_sc.pm_reloadcount, 1469 ("[pmc,%d] pmcval outside of expected range cpu=%d " 1470 "ri=%d pmcval=%jx pm_reloadcount=%jx", __LINE__, 1471 cpu, ri, newvalue, pm->pm_sc.pm_reloadcount)); 1472 } else { 1473 KASSERT(PMC_TO_MODE(pm) == PMC_MODE_TC, 1474 ("[pmc,%d] illegal mode=%d", __LINE__, 1475 PMC_TO_MODE(pm))); 1476 mtx_pool_lock_spin(pmc_mtxpool, pm); 1477 newvalue = PMC_PCPU_SAVED(cpu, ri) = 1478 pm->pm_gv.pm_savedvalue; 1479 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1480 } 1481 1482 PMCDBG3(CSW,SWI,1,"cpu=%d ri=%d new=%jd", cpu, ri, newvalue); 1483 1484 pcd->pcd_write_pmc(cpu, adjri, newvalue); 1485 1486 /* If a sampling mode PMC, reset stalled state. */ 1487 if (PMC_TO_MODE(pm) == PMC_MODE_TS) 1488 pm->pm_pcpu_state[cpu].pps_stalled = 0; 1489 1490 /* Indicate that we desire this to run. */ 1491 pm->pm_pcpu_state[cpu].pps_cpustate = 1; 1492 1493 /* Start the PMC. */ 1494 pcd->pcd_start_pmc(cpu, adjri); 1495 } 1496 1497 /* 1498 * perform any other architecture/cpu dependent thread 1499 * switch-in actions. 1500 */ 1501 1502 (void) (*md->pmd_switch_in)(pc, pp); 1503 1504 critical_exit(); 1505 1506 } 1507 1508 /* 1509 * Thread context switch OUT. 1510 */ 1511 1512 static void 1513 pmc_process_csw_out(struct thread *td) 1514 { 1515 int cpu; 1516 int64_t tmp; 1517 struct pmc *pm; 1518 struct proc *p; 1519 enum pmc_mode mode; 1520 struct pmc_cpu *pc; 1521 pmc_value_t newvalue; 1522 unsigned int adjri, ri; 1523 struct pmc_process *pp; 1524 struct pmc_thread *pt = NULL; 1525 struct pmc_classdep *pcd; 1526 1527 1528 /* 1529 * Locate our process descriptor; this may be NULL if 1530 * this process is exiting and we have already removed 1531 * the process from the target process table. 1532 * 1533 * Note that due to kernel preemption, multiple 1534 * context switches may happen while the process is 1535 * exiting. 1536 * 1537 * Note also that if the target process cannot be 1538 * found we still need to deconfigure any PMCs that 1539 * are currently running on hardware. 1540 */ 1541 1542 p = td->td_proc; 1543 pp = pmc_find_process_descriptor(p, PMC_FLAG_NONE); 1544 1545 /* 1546 * save PMCs 1547 */ 1548 1549 critical_enter(); 1550 1551 cpu = PCPU_GET(cpuid); /* td->td_oncpu is invalid */ 1552 1553 PMCDBG5(CSW,SWO,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p, 1554 p->p_pid, p->p_comm, pp); 1555 1556 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 1557 ("[pmc,%d weird CPU id %d", __LINE__, cpu)); 1558 1559 pc = pmc_pcpu[cpu]; 1560 1561 /* 1562 * When a PMC gets unlinked from a target PMC, it will 1563 * be removed from the target's pp_pmc[] array. 1564 * 1565 * However, on a MP system, the target could have been 1566 * executing on another CPU at the time of the unlink. 1567 * So, at context switch OUT time, we need to look at 1568 * the hardware to determine if a PMC is scheduled on 1569 * it. 1570 */ 1571 1572 for (ri = 0; ri < md->pmd_npmc; ri++) { 1573 1574 pcd = pmc_ri_to_classdep(md, ri, &adjri); 1575 pm = NULL; 1576 (void) (*pcd->pcd_get_config)(cpu, adjri, &pm); 1577 1578 if (pm == NULL) /* nothing at this row index */ 1579 continue; 1580 1581 mode = PMC_TO_MODE(pm); 1582 if (!PMC_IS_VIRTUAL_MODE(mode)) 1583 continue; /* not a process virtual PMC */ 1584 1585 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 1586 ("[pmc,%d] ri mismatch pmc(%d) ri(%d)", 1587 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 1588 1589 /* 1590 * Change desired state, and then stop if not stalled. 1591 * This two-step dance should avoid race conditions where 1592 * an interrupt re-enables the PMC after this code has 1593 * already checked the pm_stalled flag. 1594 */ 1595 pm->pm_pcpu_state[cpu].pps_cpustate = 0; 1596 if (pm->pm_pcpu_state[cpu].pps_stalled == 0) 1597 pcd->pcd_stop_pmc(cpu, adjri); 1598 1599 KASSERT(counter_u64_fetch(pm->pm_runcount) > 0, 1600 ("[pmc,%d] pm=%p runcount %ld", __LINE__, (void *) pm, 1601 (unsigned long)counter_u64_fetch(pm->pm_runcount))); 1602 1603 /* reduce this PMC's runcount */ 1604 counter_u64_add(pm->pm_runcount, -1); 1605 1606 /* 1607 * If this PMC is associated with this process, 1608 * save the reading. 1609 */ 1610 1611 if (pm->pm_state != PMC_STATE_DELETED && pp != NULL && 1612 pp->pp_pmcs[ri].pp_pmc != NULL) { 1613 KASSERT(pm == pp->pp_pmcs[ri].pp_pmc, 1614 ("[pmc,%d] pm %p != pp_pmcs[%d] %p", __LINE__, 1615 pm, ri, pp->pp_pmcs[ri].pp_pmc)); 1616 1617 KASSERT(pp->pp_refcnt > 0, 1618 ("[pmc,%d] pp refcnt = %d", __LINE__, 1619 pp->pp_refcnt)); 1620 1621 pcd->pcd_read_pmc(cpu, adjri, &newvalue); 1622 1623 if (mode == PMC_MODE_TS) { 1624 PMCDBG3(CSW,SWO,1,"cpu=%d ri=%d val=%jd (samp)", 1625 cpu, ri, newvalue); 1626 1627 if (pt == NULL) 1628 pt = pmc_find_thread_descriptor(pp, td, 1629 PMC_FLAG_NONE); 1630 1631 KASSERT(pt != NULL, 1632 ("[pmc,%d] No thread found for td=%p", 1633 __LINE__, td)); 1634 1635 mtx_pool_lock_spin(pmc_mtxpool, pm); 1636 1637 /* 1638 * If we have a thread descriptor, save the 1639 * per-thread counter in the descriptor. If not, 1640 * we will update the per-process counter. 1641 * 1642 * TODO: Remove the per-process "safety net" 1643 * once we have thoroughly tested that we 1644 * don't hit the above assert. 1645 */ 1646 if (pt != NULL) 1647 pt->pt_pmcs[ri].pt_pmcval = newvalue; 1648 else { 1649 /* 1650 * For sampling process-virtual PMCs, 1651 * newvalue is the number of events to 1652 * be seen until the next sampling 1653 * interrupt. We can just add the events 1654 * left from this invocation to the 1655 * counter, then adjust in case we 1656 * overflow our range. 1657 * 1658 * (Recall that we reload the counter 1659 * every time we use it.) 1660 */ 1661 pp->pp_pmcs[ri].pp_pmcval += newvalue; 1662 if (pp->pp_pmcs[ri].pp_pmcval > 1663 pm->pm_sc.pm_reloadcount) 1664 pp->pp_pmcs[ri].pp_pmcval -= 1665 pm->pm_sc.pm_reloadcount; 1666 } 1667 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1668 } else { 1669 tmp = newvalue - PMC_PCPU_SAVED(cpu,ri); 1670 1671 PMCDBG3(CSW,SWO,1,"cpu=%d ri=%d tmp=%jd (count)", 1672 cpu, ri, tmp); 1673 1674 /* 1675 * For counting process-virtual PMCs, 1676 * we expect the count to be 1677 * increasing monotonically, modulo a 64 1678 * bit wraparound. 1679 */ 1680 KASSERT(tmp >= 0, 1681 ("[pmc,%d] negative increment cpu=%d " 1682 "ri=%d newvalue=%jx saved=%jx " 1683 "incr=%jx", __LINE__, cpu, ri, 1684 newvalue, PMC_PCPU_SAVED(cpu,ri), tmp)); 1685 1686 mtx_pool_lock_spin(pmc_mtxpool, pm); 1687 pm->pm_gv.pm_savedvalue += tmp; 1688 pp->pp_pmcs[ri].pp_pmcval += tmp; 1689 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1690 1691 if (pm->pm_flags & PMC_F_LOG_PROCCSW) 1692 pmclog_process_proccsw(pm, pp, tmp, td); 1693 } 1694 } 1695 1696 /* mark hardware as free */ 1697 pcd->pcd_config_pmc(cpu, adjri, NULL); 1698 } 1699 1700 /* 1701 * perform any other architecture/cpu dependent thread 1702 * switch out functions. 1703 */ 1704 1705 (void) (*md->pmd_switch_out)(pc, pp); 1706 1707 critical_exit(); 1708 } 1709 1710 /* 1711 * A new thread for a process. 1712 */ 1713 static void 1714 pmc_process_thread_add(struct thread *td) 1715 { 1716 struct pmc_process *pmc; 1717 1718 pmc = pmc_find_process_descriptor(td->td_proc, PMC_FLAG_NONE); 1719 if (pmc != NULL) 1720 pmc_find_thread_descriptor(pmc, td, PMC_FLAG_ALLOCATE); 1721 } 1722 1723 /* 1724 * A thread delete for a process. 1725 */ 1726 static void 1727 pmc_process_thread_delete(struct thread *td) 1728 { 1729 struct pmc_process *pmc; 1730 1731 pmc = pmc_find_process_descriptor(td->td_proc, PMC_FLAG_NONE); 1732 if (pmc != NULL) 1733 pmc_thread_descriptor_pool_free(pmc_find_thread_descriptor(pmc, 1734 td, PMC_FLAG_REMOVE)); 1735 } 1736 1737 /* 1738 * A userret() call for a thread. 1739 */ 1740 static void 1741 pmc_process_thread_userret(struct thread *td) 1742 { 1743 sched_pin(); 1744 pmc_capture_user_callchain(curcpu, PMC_UR, td->td_frame); 1745 sched_unpin(); 1746 } 1747 1748 /* 1749 * A mapping change for a process. 1750 */ 1751 1752 static void 1753 pmc_process_mmap(struct thread *td, struct pmckern_map_in *pkm) 1754 { 1755 int ri; 1756 pid_t pid; 1757 char *fullpath, *freepath; 1758 const struct pmc *pm; 1759 struct pmc_owner *po; 1760 const struct pmc_process *pp; 1761 1762 freepath = fullpath = NULL; 1763 MPASS(!in_epoch(global_epoch_preempt)); 1764 pmc_getfilename((struct vnode *) pkm->pm_file, &fullpath, &freepath); 1765 1766 pid = td->td_proc->p_pid; 1767 1768 PMC_EPOCH_ENTER(); 1769 /* Inform owners of all system-wide sampling PMCs. */ 1770 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1771 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1772 pmclog_process_map_in(po, pid, pkm->pm_address, fullpath); 1773 1774 if ((pp = pmc_find_process_descriptor(td->td_proc, 0)) == NULL) 1775 goto done; 1776 1777 /* 1778 * Inform sampling PMC owners tracking this process. 1779 */ 1780 for (ri = 0; ri < md->pmd_npmc; ri++) 1781 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL && 1782 PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 1783 pmclog_process_map_in(pm->pm_owner, 1784 pid, pkm->pm_address, fullpath); 1785 1786 done: 1787 if (freepath) 1788 free(freepath, M_TEMP); 1789 PMC_EPOCH_EXIT(); 1790 } 1791 1792 1793 /* 1794 * Log an munmap request. 1795 */ 1796 1797 static void 1798 pmc_process_munmap(struct thread *td, struct pmckern_map_out *pkm) 1799 { 1800 int ri; 1801 pid_t pid; 1802 struct pmc_owner *po; 1803 const struct pmc *pm; 1804 const struct pmc_process *pp; 1805 1806 pid = td->td_proc->p_pid; 1807 1808 PMC_EPOCH_ENTER(); 1809 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1810 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1811 pmclog_process_map_out(po, pid, pkm->pm_address, 1812 pkm->pm_address + pkm->pm_size); 1813 PMC_EPOCH_EXIT(); 1814 1815 if ((pp = pmc_find_process_descriptor(td->td_proc, 0)) == NULL) 1816 return; 1817 1818 for (ri = 0; ri < md->pmd_npmc; ri++) 1819 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL && 1820 PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 1821 pmclog_process_map_out(pm->pm_owner, pid, 1822 pkm->pm_address, pkm->pm_address + pkm->pm_size); 1823 } 1824 1825 /* 1826 * Log mapping information about the kernel. 1827 */ 1828 1829 static void 1830 pmc_log_kernel_mappings(struct pmc *pm) 1831 { 1832 struct pmc_owner *po; 1833 struct pmckern_map_in *km, *kmbase; 1834 1835 MPASS(in_epoch(global_epoch_preempt) || sx_xlocked(&pmc_sx)); 1836 KASSERT(PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)), 1837 ("[pmc,%d] non-sampling PMC (%p) desires mapping information", 1838 __LINE__, (void *) pm)); 1839 1840 po = pm->pm_owner; 1841 1842 if (po->po_flags & PMC_PO_INITIAL_MAPPINGS_DONE) 1843 return; 1844 if (PMC_TO_MODE(pm) == PMC_MODE_SS) 1845 pmc_process_allproc(pm); 1846 /* 1847 * Log the current set of kernel modules. 1848 */ 1849 kmbase = linker_hwpmc_list_objects(); 1850 for (km = kmbase; km->pm_file != NULL; km++) { 1851 PMCDBG2(LOG,REG,1,"%s %p", (char *) km->pm_file, 1852 (void *) km->pm_address); 1853 pmclog_process_map_in(po, (pid_t) -1, km->pm_address, 1854 km->pm_file); 1855 } 1856 free(kmbase, M_LINKER); 1857 1858 po->po_flags |= PMC_PO_INITIAL_MAPPINGS_DONE; 1859 } 1860 1861 /* 1862 * Log the mappings for a single process. 1863 */ 1864 1865 static void 1866 pmc_log_process_mappings(struct pmc_owner *po, struct proc *p) 1867 { 1868 vm_map_t map; 1869 struct vnode *vp; 1870 struct vmspace *vm; 1871 vm_map_entry_t entry; 1872 vm_offset_t last_end; 1873 u_int last_timestamp; 1874 struct vnode *last_vp; 1875 vm_offset_t start_addr; 1876 vm_object_t obj, lobj, tobj; 1877 char *fullpath, *freepath; 1878 1879 last_vp = NULL; 1880 last_end = (vm_offset_t) 0; 1881 fullpath = freepath = NULL; 1882 1883 if ((vm = vmspace_acquire_ref(p)) == NULL) 1884 return; 1885 1886 map = &vm->vm_map; 1887 vm_map_lock_read(map); 1888 1889 VM_MAP_ENTRY_FOREACH(entry, map) { 1890 1891 if (entry == NULL) { 1892 PMCDBG2(LOG,OPS,2, "hwpmc: vm_map entry unexpectedly " 1893 "NULL! pid=%d vm_map=%p\n", p->p_pid, map); 1894 break; 1895 } 1896 1897 /* 1898 * We only care about executable map entries. 1899 */ 1900 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) || 1901 !(entry->protection & VM_PROT_EXECUTE) || 1902 (entry->object.vm_object == NULL)) { 1903 continue; 1904 } 1905 1906 obj = entry->object.vm_object; 1907 VM_OBJECT_RLOCK(obj); 1908 1909 /* 1910 * Walk the backing_object list to find the base 1911 * (non-shadowed) vm_object. 1912 */ 1913 for (lobj = tobj = obj; tobj != NULL; tobj = tobj->backing_object) { 1914 if (tobj != obj) 1915 VM_OBJECT_RLOCK(tobj); 1916 if (lobj != obj) 1917 VM_OBJECT_RUNLOCK(lobj); 1918 lobj = tobj; 1919 } 1920 1921 /* 1922 * At this point lobj is the base vm_object and it is locked. 1923 */ 1924 if (lobj == NULL) { 1925 PMCDBG3(LOG,OPS,2, "hwpmc: lobj unexpectedly NULL! pid=%d " 1926 "vm_map=%p vm_obj=%p\n", p->p_pid, map, obj); 1927 VM_OBJECT_RUNLOCK(obj); 1928 continue; 1929 } 1930 1931 vp = vm_object_vnode(lobj); 1932 if (vp == NULL) { 1933 if (lobj != obj) 1934 VM_OBJECT_RUNLOCK(lobj); 1935 VM_OBJECT_RUNLOCK(obj); 1936 continue; 1937 } 1938 1939 /* 1940 * Skip contiguous regions that point to the same 1941 * vnode, so we don't emit redundant MAP-IN 1942 * directives. 1943 */ 1944 if (entry->start == last_end && vp == last_vp) { 1945 last_end = entry->end; 1946 if (lobj != obj) 1947 VM_OBJECT_RUNLOCK(lobj); 1948 VM_OBJECT_RUNLOCK(obj); 1949 continue; 1950 } 1951 1952 /* 1953 * We don't want to keep the proc's vm_map or this 1954 * vm_object locked while we walk the pathname, since 1955 * vn_fullpath() can sleep. However, if we drop the 1956 * lock, it's possible for concurrent activity to 1957 * modify the vm_map list. To protect against this, 1958 * we save the vm_map timestamp before we release the 1959 * lock, and check it after we reacquire the lock 1960 * below. 1961 */ 1962 start_addr = entry->start; 1963 last_end = entry->end; 1964 last_timestamp = map->timestamp; 1965 vm_map_unlock_read(map); 1966 1967 vref(vp); 1968 if (lobj != obj) 1969 VM_OBJECT_RUNLOCK(lobj); 1970 1971 VM_OBJECT_RUNLOCK(obj); 1972 1973 freepath = NULL; 1974 pmc_getfilename(vp, &fullpath, &freepath); 1975 last_vp = vp; 1976 1977 vrele(vp); 1978 1979 vp = NULL; 1980 pmclog_process_map_in(po, p->p_pid, start_addr, fullpath); 1981 if (freepath) 1982 free(freepath, M_TEMP); 1983 1984 vm_map_lock_read(map); 1985 1986 /* 1987 * If our saved timestamp doesn't match, this means 1988 * that the vm_map was modified out from under us and 1989 * we can't trust our current "entry" pointer. Do a 1990 * new lookup for this entry. If there is no entry 1991 * for this address range, vm_map_lookup_entry() will 1992 * return the previous one, so we always want to go to 1993 * the next entry on the next loop iteration. 1994 * 1995 * There is an edge condition here that can occur if 1996 * there is no entry at or before this address. In 1997 * this situation, vm_map_lookup_entry returns 1998 * &map->header, which would cause our loop to abort 1999 * without processing the rest of the map. However, 2000 * in practice this will never happen for process 2001 * vm_map. This is because the executable's text 2002 * segment is the first mapping in the proc's address 2003 * space, and this mapping is never removed until the 2004 * process exits, so there will always be a non-header 2005 * entry at or before the requested address for 2006 * vm_map_lookup_entry to return. 2007 */ 2008 if (map->timestamp != last_timestamp) 2009 vm_map_lookup_entry(map, last_end - 1, &entry); 2010 } 2011 2012 vm_map_unlock_read(map); 2013 vmspace_free(vm); 2014 return; 2015 } 2016 2017 /* 2018 * Log mappings for all processes in the system. 2019 */ 2020 2021 static void 2022 pmc_log_all_process_mappings(struct pmc_owner *po) 2023 { 2024 struct proc *p, *top; 2025 2026 sx_assert(&pmc_sx, SX_XLOCKED); 2027 2028 if ((p = pfind(1)) == NULL) 2029 panic("[pmc,%d] Cannot find init", __LINE__); 2030 2031 PROC_UNLOCK(p); 2032 2033 sx_slock(&proctree_lock); 2034 2035 top = p; 2036 2037 for (;;) { 2038 pmc_log_process_mappings(po, p); 2039 if (!LIST_EMPTY(&p->p_children)) 2040 p = LIST_FIRST(&p->p_children); 2041 else for (;;) { 2042 if (p == top) 2043 goto done; 2044 if (LIST_NEXT(p, p_sibling)) { 2045 p = LIST_NEXT(p, p_sibling); 2046 break; 2047 } 2048 p = p->p_pptr; 2049 } 2050 } 2051 done: 2052 sx_sunlock(&proctree_lock); 2053 } 2054 2055 /* 2056 * The 'hook' invoked from the kernel proper 2057 */ 2058 2059 2060 #ifdef HWPMC_DEBUG 2061 const char *pmc_hooknames[] = { 2062 /* these strings correspond to PMC_FN_* in <sys/pmckern.h> */ 2063 "", 2064 "EXEC", 2065 "CSW-IN", 2066 "CSW-OUT", 2067 "SAMPLE", 2068 "UNUSED1", 2069 "UNUSED2", 2070 "MMAP", 2071 "MUNMAP", 2072 "CALLCHAIN-NMI", 2073 "CALLCHAIN-SOFT", 2074 "SOFTSAMPLING", 2075 "THR-CREATE", 2076 "THR-EXIT", 2077 "THR-USERRET", 2078 "THR-CREATE-LOG", 2079 "THR-EXIT-LOG", 2080 "PROC-CREATE-LOG" 2081 }; 2082 #endif 2083 2084 static int 2085 pmc_hook_handler(struct thread *td, int function, void *arg) 2086 { 2087 int cpu; 2088 2089 PMCDBG4(MOD,PMH,1, "hook td=%p func=%d \"%s\" arg=%p", td, function, 2090 pmc_hooknames[function], arg); 2091 2092 switch (function) 2093 { 2094 2095 /* 2096 * Process exec() 2097 */ 2098 2099 case PMC_FN_PROCESS_EXEC: 2100 { 2101 char *fullpath, *freepath; 2102 unsigned int ri; 2103 int is_using_hwpmcs; 2104 struct pmc *pm; 2105 struct proc *p; 2106 struct pmc_owner *po; 2107 struct pmc_process *pp; 2108 struct pmckern_procexec *pk; 2109 2110 sx_assert(&pmc_sx, SX_XLOCKED); 2111 2112 p = td->td_proc; 2113 pmc_getfilename(p->p_textvp, &fullpath, &freepath); 2114 2115 pk = (struct pmckern_procexec *) arg; 2116 2117 PMC_EPOCH_ENTER(); 2118 /* Inform owners of SS mode PMCs of the exec event. */ 2119 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 2120 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 2121 pmclog_process_procexec(po, PMC_ID_INVALID, 2122 p->p_pid, pk->pm_entryaddr, fullpath); 2123 PMC_EPOCH_EXIT(); 2124 2125 PROC_LOCK(p); 2126 is_using_hwpmcs = p->p_flag & P_HWPMC; 2127 PROC_UNLOCK(p); 2128 2129 if (!is_using_hwpmcs) { 2130 if (freepath) 2131 free(freepath, M_TEMP); 2132 break; 2133 } 2134 2135 /* 2136 * PMCs are not inherited across an exec(): remove any 2137 * PMCs that this process is the owner of. 2138 */ 2139 2140 if ((po = pmc_find_owner_descriptor(p)) != NULL) { 2141 pmc_remove_owner(po); 2142 pmc_destroy_owner_descriptor(po); 2143 } 2144 2145 /* 2146 * If the process being exec'ed is not the target of any 2147 * PMC, we are done. 2148 */ 2149 if ((pp = pmc_find_process_descriptor(p, 0)) == NULL) { 2150 if (freepath) 2151 free(freepath, M_TEMP); 2152 break; 2153 } 2154 2155 /* 2156 * Log the exec event to all monitoring owners. Skip 2157 * owners who have already received the event because 2158 * they had system sampling PMCs active. 2159 */ 2160 for (ri = 0; ri < md->pmd_npmc; ri++) 2161 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) { 2162 po = pm->pm_owner; 2163 if (po->po_sscount == 0 && 2164 po->po_flags & PMC_PO_OWNS_LOGFILE) 2165 pmclog_process_procexec(po, pm->pm_id, 2166 p->p_pid, pk->pm_entryaddr, 2167 fullpath); 2168 } 2169 2170 if (freepath) 2171 free(freepath, M_TEMP); 2172 2173 2174 PMCDBG4(PRC,EXC,1, "exec proc=%p (%d, %s) cred-changed=%d", 2175 p, p->p_pid, p->p_comm, pk->pm_credentialschanged); 2176 2177 if (pk->pm_credentialschanged == 0) /* no change */ 2178 break; 2179 2180 /* 2181 * If the newly exec()'ed process has a different credential 2182 * than before, allow it to be the target of a PMC only if 2183 * the PMC's owner has sufficient privilege. 2184 */ 2185 2186 for (ri = 0; ri < md->pmd_npmc; ri++) 2187 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) 2188 if (pmc_can_attach(pm, td->td_proc) != 0) 2189 pmc_detach_one_process(td->td_proc, 2190 pm, PMC_FLAG_NONE); 2191 2192 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= (int) md->pmd_npmc, 2193 ("[pmc,%d] Illegal ref count %d on pp %p", __LINE__, 2194 pp->pp_refcnt, pp)); 2195 2196 /* 2197 * If this process is no longer the target of any 2198 * PMCs, we can remove the process entry and free 2199 * up space. 2200 */ 2201 2202 if (pp->pp_refcnt == 0) { 2203 pmc_remove_process_descriptor(pp); 2204 pmc_destroy_process_descriptor(pp); 2205 break; 2206 } 2207 2208 } 2209 break; 2210 2211 case PMC_FN_CSW_IN: 2212 pmc_process_csw_in(td); 2213 break; 2214 2215 case PMC_FN_CSW_OUT: 2216 pmc_process_csw_out(td); 2217 break; 2218 2219 /* 2220 * Process accumulated PC samples. 2221 * 2222 * This function is expected to be called by hardclock() for 2223 * each CPU that has accumulated PC samples. 2224 * 2225 * This function is to be executed on the CPU whose samples 2226 * are being processed. 2227 */ 2228 case PMC_FN_DO_SAMPLES: 2229 2230 /* 2231 * Clear the cpu specific bit in the CPU mask before 2232 * do the rest of the processing. If the NMI handler 2233 * gets invoked after the "atomic_clear_int()" call 2234 * below but before "pmc_process_samples()" gets 2235 * around to processing the interrupt, then we will 2236 * come back here at the next hardclock() tick (and 2237 * may find nothing to do if "pmc_process_samples()" 2238 * had already processed the interrupt). We don't 2239 * lose the interrupt sample. 2240 */ 2241 DPCPU_SET(pmc_sampled, 0); 2242 cpu = PCPU_GET(cpuid); 2243 pmc_process_samples(cpu, PMC_HR); 2244 pmc_process_samples(cpu, PMC_SR); 2245 pmc_process_samples(cpu, PMC_UR); 2246 break; 2247 2248 case PMC_FN_MMAP: 2249 pmc_process_mmap(td, (struct pmckern_map_in *) arg); 2250 break; 2251 2252 case PMC_FN_MUNMAP: 2253 MPASS(in_epoch(global_epoch_preempt) || sx_xlocked(&pmc_sx)); 2254 pmc_process_munmap(td, (struct pmckern_map_out *) arg); 2255 break; 2256 2257 case PMC_FN_PROC_CREATE_LOG: 2258 pmc_process_proccreate((struct proc *)arg); 2259 break; 2260 2261 case PMC_FN_USER_CALLCHAIN: 2262 /* 2263 * Record a call chain. 2264 */ 2265 KASSERT(td == curthread, ("[pmc,%d] td != curthread", 2266 __LINE__)); 2267 2268 pmc_capture_user_callchain(PCPU_GET(cpuid), PMC_HR, 2269 (struct trapframe *) arg); 2270 2271 KASSERT(td->td_pinned == 1, 2272 ("[pmc,%d] invalid td_pinned value", __LINE__)); 2273 sched_unpin(); /* Can migrate safely now. */ 2274 2275 td->td_pflags &= ~TDP_CALLCHAIN; 2276 break; 2277 2278 case PMC_FN_USER_CALLCHAIN_SOFT: 2279 /* 2280 * Record a call chain. 2281 */ 2282 KASSERT(td == curthread, ("[pmc,%d] td != curthread", 2283 __LINE__)); 2284 2285 cpu = PCPU_GET(cpuid); 2286 pmc_capture_user_callchain(cpu, PMC_SR, 2287 (struct trapframe *) arg); 2288 2289 KASSERT(td->td_pinned == 1, 2290 ("[pmc,%d] invalid td_pinned value", __LINE__)); 2291 2292 sched_unpin(); /* Can migrate safely now. */ 2293 2294 td->td_pflags &= ~TDP_CALLCHAIN; 2295 break; 2296 2297 case PMC_FN_SOFT_SAMPLING: 2298 /* 2299 * Call soft PMC sampling intr. 2300 */ 2301 pmc_soft_intr((struct pmckern_soft *) arg); 2302 break; 2303 2304 case PMC_FN_THR_CREATE: 2305 pmc_process_thread_add(td); 2306 pmc_process_threadcreate(td); 2307 break; 2308 2309 case PMC_FN_THR_CREATE_LOG: 2310 pmc_process_threadcreate(td); 2311 break; 2312 2313 case PMC_FN_THR_EXIT: 2314 KASSERT(td == curthread, ("[pmc,%d] td != curthread", 2315 __LINE__)); 2316 pmc_process_thread_delete(td); 2317 pmc_process_threadexit(td); 2318 break; 2319 case PMC_FN_THR_EXIT_LOG: 2320 pmc_process_threadexit(td); 2321 break; 2322 case PMC_FN_THR_USERRET: 2323 KASSERT(td == curthread, ("[pmc,%d] td != curthread", 2324 __LINE__)); 2325 pmc_process_thread_userret(td); 2326 break; 2327 2328 default: 2329 #ifdef HWPMC_DEBUG 2330 KASSERT(0, ("[pmc,%d] unknown hook %d\n", __LINE__, function)); 2331 #endif 2332 break; 2333 2334 } 2335 2336 return 0; 2337 } 2338 2339 /* 2340 * allocate a 'struct pmc_owner' descriptor in the owner hash table. 2341 */ 2342 2343 static struct pmc_owner * 2344 pmc_allocate_owner_descriptor(struct proc *p) 2345 { 2346 uint32_t hindex; 2347 struct pmc_owner *po; 2348 struct pmc_ownerhash *poh; 2349 2350 hindex = PMC_HASH_PTR(p, pmc_ownerhashmask); 2351 poh = &pmc_ownerhash[hindex]; 2352 2353 /* allocate space for N pointers and one descriptor struct */ 2354 po = malloc(sizeof(struct pmc_owner), M_PMC, M_WAITOK|M_ZERO); 2355 po->po_owner = p; 2356 LIST_INSERT_HEAD(poh, po, po_next); /* insert into hash table */ 2357 2358 TAILQ_INIT(&po->po_logbuffers); 2359 mtx_init(&po->po_mtx, "pmc-owner-mtx", "pmc-per-proc", MTX_SPIN); 2360 2361 PMCDBG4(OWN,ALL,1, "allocate-owner proc=%p (%d, %s) pmc-owner=%p", 2362 p, p->p_pid, p->p_comm, po); 2363 2364 return po; 2365 } 2366 2367 static void 2368 pmc_destroy_owner_descriptor(struct pmc_owner *po) 2369 { 2370 2371 PMCDBG4(OWN,REL,1, "destroy-owner po=%p proc=%p (%d, %s)", 2372 po, po->po_owner, po->po_owner->p_pid, po->po_owner->p_comm); 2373 2374 mtx_destroy(&po->po_mtx); 2375 free(po, M_PMC); 2376 } 2377 2378 /* 2379 * Allocate a thread descriptor from the free pool. 2380 * 2381 * NOTE: This *can* return NULL. 2382 */ 2383 static struct pmc_thread * 2384 pmc_thread_descriptor_pool_alloc(void) 2385 { 2386 struct pmc_thread *pt; 2387 2388 mtx_lock_spin(&pmc_threadfreelist_mtx); 2389 if ((pt = LIST_FIRST(&pmc_threadfreelist)) != NULL) { 2390 LIST_REMOVE(pt, pt_next); 2391 pmc_threadfreelist_entries--; 2392 } 2393 mtx_unlock_spin(&pmc_threadfreelist_mtx); 2394 2395 return (pt); 2396 } 2397 2398 /* 2399 * Add a thread descriptor to the free pool. We use this instead of free() 2400 * to maintain a cache of free entries. Additionally, we can safely call 2401 * this function when we cannot call free(), such as in a critical section. 2402 * 2403 */ 2404 static void 2405 pmc_thread_descriptor_pool_free(struct pmc_thread *pt) 2406 { 2407 2408 if (pt == NULL) 2409 return; 2410 2411 memset(pt, 0, THREADENTRY_SIZE); 2412 mtx_lock_spin(&pmc_threadfreelist_mtx); 2413 LIST_INSERT_HEAD(&pmc_threadfreelist, pt, pt_next); 2414 pmc_threadfreelist_entries++; 2415 if (pmc_threadfreelist_entries > pmc_threadfreelist_max) 2416 taskqueue_enqueue(taskqueue_fast, &free_task); 2417 mtx_unlock_spin(&pmc_threadfreelist_mtx); 2418 } 2419 2420 /* 2421 * An asynchronous task to manage the free list. 2422 */ 2423 static void 2424 pmc_thread_descriptor_pool_free_task(void *arg __unused, int pending __unused) 2425 { 2426 struct pmc_thread *pt; 2427 LIST_HEAD(, pmc_thread) tmplist; 2428 int delta; 2429 2430 LIST_INIT(&tmplist); 2431 2432 /* Determine what changes, if any, we need to make. */ 2433 mtx_lock_spin(&pmc_threadfreelist_mtx); 2434 delta = pmc_threadfreelist_entries - pmc_threadfreelist_max; 2435 while (delta > 0 && (pt = LIST_FIRST(&pmc_threadfreelist)) != NULL) { 2436 delta--; 2437 pmc_threadfreelist_entries--; 2438 LIST_REMOVE(pt, pt_next); 2439 LIST_INSERT_HEAD(&tmplist, pt, pt_next); 2440 } 2441 mtx_unlock_spin(&pmc_threadfreelist_mtx); 2442 2443 /* If there are entries to free, free them. */ 2444 while (!LIST_EMPTY(&tmplist)) { 2445 pt = LIST_FIRST(&tmplist); 2446 LIST_REMOVE(pt, pt_next); 2447 free(pt, M_PMC); 2448 } 2449 } 2450 2451 /* 2452 * Drain the thread free pool, freeing all allocations. 2453 */ 2454 static void 2455 pmc_thread_descriptor_pool_drain() 2456 { 2457 struct pmc_thread *pt, *next; 2458 2459 LIST_FOREACH_SAFE(pt, &pmc_threadfreelist, pt_next, next) { 2460 LIST_REMOVE(pt, pt_next); 2461 free(pt, M_PMC); 2462 } 2463 } 2464 2465 /* 2466 * find the descriptor corresponding to thread 'td', adding or removing it 2467 * as specified by 'mode'. 2468 * 2469 * Note that this supports additional mode flags in addition to those 2470 * supported by pmc_find_process_descriptor(): 2471 * PMC_FLAG_NOWAIT: Causes the function to not wait for mallocs. 2472 * This makes it safe to call while holding certain other locks. 2473 */ 2474 2475 static struct pmc_thread * 2476 pmc_find_thread_descriptor(struct pmc_process *pp, struct thread *td, 2477 uint32_t mode) 2478 { 2479 struct pmc_thread *pt = NULL, *ptnew = NULL; 2480 int wait_flag; 2481 2482 KASSERT(td != NULL, ("[pmc,%d] called to add NULL td", __LINE__)); 2483 2484 /* 2485 * Pre-allocate memory in the PMC_FLAG_ALLOCATE case prior to 2486 * acquiring the lock. 2487 */ 2488 if (mode & PMC_FLAG_ALLOCATE) { 2489 if ((ptnew = pmc_thread_descriptor_pool_alloc()) == NULL) { 2490 wait_flag = M_WAITOK; 2491 if ((mode & PMC_FLAG_NOWAIT) || in_epoch(global_epoch_preempt)) 2492 wait_flag = M_NOWAIT; 2493 2494 ptnew = malloc(THREADENTRY_SIZE, M_PMC, 2495 wait_flag|M_ZERO); 2496 } 2497 } 2498 2499 mtx_lock_spin(pp->pp_tdslock); 2500 2501 LIST_FOREACH(pt, &pp->pp_tds, pt_next) 2502 if (pt->pt_td == td) 2503 break; 2504 2505 if ((mode & PMC_FLAG_REMOVE) && pt != NULL) 2506 LIST_REMOVE(pt, pt_next); 2507 2508 if ((mode & PMC_FLAG_ALLOCATE) && pt == NULL && ptnew != NULL) { 2509 pt = ptnew; 2510 ptnew = NULL; 2511 pt->pt_td = td; 2512 LIST_INSERT_HEAD(&pp->pp_tds, pt, pt_next); 2513 } 2514 2515 mtx_unlock_spin(pp->pp_tdslock); 2516 2517 if (ptnew != NULL) { 2518 free(ptnew, M_PMC); 2519 } 2520 2521 return pt; 2522 } 2523 2524 /* 2525 * Try to add thread descriptors for each thread in a process. 2526 */ 2527 2528 static void 2529 pmc_add_thread_descriptors_from_proc(struct proc *p, struct pmc_process *pp) 2530 { 2531 struct thread *curtd; 2532 struct pmc_thread **tdlist; 2533 int i, tdcnt, tdlistsz; 2534 2535 KASSERT(!PROC_LOCKED(p), ("[pmc,%d] proc unexpectedly locked", 2536 __LINE__)); 2537 tdcnt = 32; 2538 restart: 2539 tdlistsz = roundup2(tdcnt, 32); 2540 2541 tdcnt = 0; 2542 tdlist = malloc(sizeof(struct pmc_thread*) * tdlistsz, M_TEMP, M_WAITOK); 2543 2544 PROC_LOCK(p); 2545 FOREACH_THREAD_IN_PROC(p, curtd) 2546 tdcnt++; 2547 if (tdcnt >= tdlistsz) { 2548 PROC_UNLOCK(p); 2549 free(tdlist, M_TEMP); 2550 goto restart; 2551 } 2552 /* 2553 * Try to add each thread to the list without sleeping. If unable, 2554 * add to a queue to retry after dropping the process lock. 2555 */ 2556 tdcnt = 0; 2557 FOREACH_THREAD_IN_PROC(p, curtd) { 2558 tdlist[tdcnt] = pmc_find_thread_descriptor(pp, curtd, 2559 PMC_FLAG_ALLOCATE|PMC_FLAG_NOWAIT); 2560 if (tdlist[tdcnt] == NULL) { 2561 PROC_UNLOCK(p); 2562 for (i = 0; i <= tdcnt; i++) 2563 pmc_thread_descriptor_pool_free(tdlist[i]); 2564 free(tdlist, M_TEMP); 2565 goto restart; 2566 } 2567 tdcnt++; 2568 } 2569 PROC_UNLOCK(p); 2570 free(tdlist, M_TEMP); 2571 } 2572 2573 /* 2574 * find the descriptor corresponding to process 'p', adding or removing it 2575 * as specified by 'mode'. 2576 */ 2577 2578 static struct pmc_process * 2579 pmc_find_process_descriptor(struct proc *p, uint32_t mode) 2580 { 2581 uint32_t hindex; 2582 struct pmc_process *pp, *ppnew; 2583 struct pmc_processhash *pph; 2584 2585 hindex = PMC_HASH_PTR(p, pmc_processhashmask); 2586 pph = &pmc_processhash[hindex]; 2587 2588 ppnew = NULL; 2589 2590 /* 2591 * Pre-allocate memory in the PMC_FLAG_ALLOCATE case since we 2592 * cannot call malloc(9) once we hold a spin lock. 2593 */ 2594 if (mode & PMC_FLAG_ALLOCATE) 2595 ppnew = malloc(sizeof(struct pmc_process) + md->pmd_npmc * 2596 sizeof(struct pmc_targetstate), M_PMC, M_WAITOK|M_ZERO); 2597 2598 mtx_lock_spin(&pmc_processhash_mtx); 2599 LIST_FOREACH(pp, pph, pp_next) 2600 if (pp->pp_proc == p) 2601 break; 2602 2603 if ((mode & PMC_FLAG_REMOVE) && pp != NULL) 2604 LIST_REMOVE(pp, pp_next); 2605 2606 if ((mode & PMC_FLAG_ALLOCATE) && pp == NULL && 2607 ppnew != NULL) { 2608 ppnew->pp_proc = p; 2609 LIST_INIT(&ppnew->pp_tds); 2610 ppnew->pp_tdslock = mtx_pool_find(pmc_mtxpool, ppnew); 2611 LIST_INSERT_HEAD(pph, ppnew, pp_next); 2612 mtx_unlock_spin(&pmc_processhash_mtx); 2613 pp = ppnew; 2614 ppnew = NULL; 2615 2616 /* Add thread descriptors for this process' current threads. */ 2617 pmc_add_thread_descriptors_from_proc(p, pp); 2618 } 2619 else 2620 mtx_unlock_spin(&pmc_processhash_mtx); 2621 2622 if (ppnew != NULL) 2623 free(ppnew, M_PMC); 2624 2625 return pp; 2626 } 2627 2628 /* 2629 * remove a process descriptor from the process hash table. 2630 */ 2631 2632 static void 2633 pmc_remove_process_descriptor(struct pmc_process *pp) 2634 { 2635 KASSERT(pp->pp_refcnt == 0, 2636 ("[pmc,%d] Removing process descriptor %p with count %d", 2637 __LINE__, pp, pp->pp_refcnt)); 2638 2639 mtx_lock_spin(&pmc_processhash_mtx); 2640 LIST_REMOVE(pp, pp_next); 2641 mtx_unlock_spin(&pmc_processhash_mtx); 2642 } 2643 2644 /* 2645 * destroy a process descriptor. 2646 */ 2647 2648 static void 2649 pmc_destroy_process_descriptor(struct pmc_process *pp) 2650 { 2651 struct pmc_thread *pmc_td; 2652 2653 while ((pmc_td = LIST_FIRST(&pp->pp_tds)) != NULL) { 2654 LIST_REMOVE(pmc_td, pt_next); 2655 pmc_thread_descriptor_pool_free(pmc_td); 2656 } 2657 free(pp, M_PMC); 2658 } 2659 2660 2661 /* 2662 * find an owner descriptor corresponding to proc 'p' 2663 */ 2664 2665 static struct pmc_owner * 2666 pmc_find_owner_descriptor(struct proc *p) 2667 { 2668 uint32_t hindex; 2669 struct pmc_owner *po; 2670 struct pmc_ownerhash *poh; 2671 2672 hindex = PMC_HASH_PTR(p, pmc_ownerhashmask); 2673 poh = &pmc_ownerhash[hindex]; 2674 2675 po = NULL; 2676 LIST_FOREACH(po, poh, po_next) 2677 if (po->po_owner == p) 2678 break; 2679 2680 PMCDBG5(OWN,FND,1, "find-owner proc=%p (%d, %s) hindex=0x%x -> " 2681 "pmc-owner=%p", p, p->p_pid, p->p_comm, hindex, po); 2682 2683 return po; 2684 } 2685 2686 /* 2687 * pmc_allocate_pmc_descriptor 2688 * 2689 * Allocate a pmc descriptor and initialize its 2690 * fields. 2691 */ 2692 2693 static struct pmc * 2694 pmc_allocate_pmc_descriptor(void) 2695 { 2696 struct pmc *pmc; 2697 2698 pmc = malloc(sizeof(struct pmc), M_PMC, M_WAITOK|M_ZERO); 2699 pmc->pm_runcount = counter_u64_alloc(M_WAITOK); 2700 pmc->pm_pcpu_state = malloc(sizeof(struct pmc_pcpu_state)*mp_ncpus, M_PMC, M_WAITOK|M_ZERO); 2701 PMCDBG1(PMC,ALL,1, "allocate-pmc -> pmc=%p", pmc); 2702 2703 return pmc; 2704 } 2705 2706 /* 2707 * Destroy a pmc descriptor. 2708 */ 2709 2710 static void 2711 pmc_destroy_pmc_descriptor(struct pmc *pm) 2712 { 2713 2714 KASSERT(pm->pm_state == PMC_STATE_DELETED || 2715 pm->pm_state == PMC_STATE_FREE, 2716 ("[pmc,%d] destroying non-deleted PMC", __LINE__)); 2717 KASSERT(LIST_EMPTY(&pm->pm_targets), 2718 ("[pmc,%d] destroying pmc with targets", __LINE__)); 2719 KASSERT(pm->pm_owner == NULL, 2720 ("[pmc,%d] destroying pmc attached to an owner", __LINE__)); 2721 KASSERT(counter_u64_fetch(pm->pm_runcount) == 0, 2722 ("[pmc,%d] pmc has non-zero run count %ld", __LINE__, 2723 (unsigned long)counter_u64_fetch(pm->pm_runcount))); 2724 2725 counter_u64_free(pm->pm_runcount); 2726 free(pm->pm_pcpu_state, M_PMC); 2727 free(pm, M_PMC); 2728 } 2729 2730 static void 2731 pmc_wait_for_pmc_idle(struct pmc *pm) 2732 { 2733 #ifdef INVARIANTS 2734 volatile int maxloop; 2735 2736 maxloop = 100 * pmc_cpu_max(); 2737 #endif 2738 /* 2739 * Loop (with a forced context switch) till the PMC's runcount 2740 * comes down to zero. 2741 */ 2742 pmclog_flush(pm->pm_owner, 1); 2743 while (counter_u64_fetch(pm->pm_runcount) > 0) { 2744 pmclog_flush(pm->pm_owner, 1); 2745 #ifdef INVARIANTS 2746 maxloop--; 2747 KASSERT(maxloop > 0, 2748 ("[pmc,%d] (ri%d, rc%ld) waiting too long for " 2749 "pmc to be free", __LINE__, 2750 PMC_TO_ROWINDEX(pm), (unsigned long)counter_u64_fetch(pm->pm_runcount))); 2751 #endif 2752 pmc_force_context_switch(); 2753 } 2754 } 2755 2756 /* 2757 * This function does the following things: 2758 * 2759 * - detaches the PMC from hardware 2760 * - unlinks all target threads that were attached to it 2761 * - removes the PMC from its owner's list 2762 * - destroys the PMC private mutex 2763 * 2764 * Once this function completes, the given pmc pointer can be freed by 2765 * calling pmc_destroy_pmc_descriptor(). 2766 */ 2767 2768 static void 2769 pmc_release_pmc_descriptor(struct pmc *pm) 2770 { 2771 enum pmc_mode mode; 2772 struct pmc_hw *phw; 2773 u_int adjri, ri, cpu; 2774 struct pmc_owner *po; 2775 struct pmc_binding pb; 2776 struct pmc_process *pp; 2777 struct pmc_classdep *pcd; 2778 struct pmc_target *ptgt, *tmp; 2779 2780 sx_assert(&pmc_sx, SX_XLOCKED); 2781 2782 KASSERT(pm, ("[pmc,%d] null pmc", __LINE__)); 2783 2784 ri = PMC_TO_ROWINDEX(pm); 2785 pcd = pmc_ri_to_classdep(md, ri, &adjri); 2786 mode = PMC_TO_MODE(pm); 2787 2788 PMCDBG3(PMC,REL,1, "release-pmc pmc=%p ri=%d mode=%d", pm, ri, 2789 mode); 2790 2791 /* 2792 * First, we take the PMC off hardware. 2793 */ 2794 cpu = 0; 2795 if (PMC_IS_SYSTEM_MODE(mode)) { 2796 2797 /* 2798 * A system mode PMC runs on a specific CPU. Switch 2799 * to this CPU and turn hardware off. 2800 */ 2801 pmc_save_cpu_binding(&pb); 2802 2803 cpu = PMC_TO_CPU(pm); 2804 2805 pmc_select_cpu(cpu); 2806 2807 /* switch off non-stalled CPUs */ 2808 pm->pm_pcpu_state[cpu].pps_cpustate = 0; 2809 if (pm->pm_state == PMC_STATE_RUNNING && 2810 pm->pm_pcpu_state[cpu].pps_stalled == 0) { 2811 2812 phw = pmc_pcpu[cpu]->pc_hwpmcs[ri]; 2813 2814 KASSERT(phw->phw_pmc == pm, 2815 ("[pmc, %d] pmc ptr ri(%d) hw(%p) pm(%p)", 2816 __LINE__, ri, phw->phw_pmc, pm)); 2817 PMCDBG2(PMC,REL,2, "stopping cpu=%d ri=%d", cpu, ri); 2818 2819 critical_enter(); 2820 pcd->pcd_stop_pmc(cpu, adjri); 2821 critical_exit(); 2822 } 2823 2824 PMCDBG2(PMC,REL,2, "decfg cpu=%d ri=%d", cpu, ri); 2825 2826 critical_enter(); 2827 pcd->pcd_config_pmc(cpu, adjri, NULL); 2828 critical_exit(); 2829 2830 /* adjust the global and process count of SS mode PMCs */ 2831 if (mode == PMC_MODE_SS && pm->pm_state == PMC_STATE_RUNNING) { 2832 po = pm->pm_owner; 2833 po->po_sscount--; 2834 if (po->po_sscount == 0) { 2835 atomic_subtract_rel_int(&pmc_ss_count, 1); 2836 CK_LIST_REMOVE(po, po_ssnext); 2837 epoch_wait_preempt(global_epoch_preempt); 2838 } 2839 } 2840 2841 pm->pm_state = PMC_STATE_DELETED; 2842 2843 pmc_restore_cpu_binding(&pb); 2844 2845 /* 2846 * We could have references to this PMC structure in 2847 * the per-cpu sample queues. Wait for the queue to 2848 * drain. 2849 */ 2850 pmc_wait_for_pmc_idle(pm); 2851 2852 } else if (PMC_IS_VIRTUAL_MODE(mode)) { 2853 2854 /* 2855 * A virtual PMC could be running on multiple CPUs at 2856 * a given instant. 2857 * 2858 * By marking its state as DELETED, we ensure that 2859 * this PMC is never further scheduled on hardware. 2860 * 2861 * Then we wait till all CPUs are done with this PMC. 2862 */ 2863 pm->pm_state = PMC_STATE_DELETED; 2864 2865 2866 /* Wait for the PMCs runcount to come to zero. */ 2867 pmc_wait_for_pmc_idle(pm); 2868 2869 /* 2870 * At this point the PMC is off all CPUs and cannot be 2871 * freshly scheduled onto a CPU. It is now safe to 2872 * unlink all targets from this PMC. If a 2873 * process-record's refcount falls to zero, we remove 2874 * it from the hash table. The module-wide SX lock 2875 * protects us from races. 2876 */ 2877 LIST_FOREACH_SAFE(ptgt, &pm->pm_targets, pt_next, tmp) { 2878 pp = ptgt->pt_process; 2879 pmc_unlink_target_process(pm, pp); /* frees 'ptgt' */ 2880 2881 PMCDBG1(PMC,REL,3, "pp->refcnt=%d", pp->pp_refcnt); 2882 2883 /* 2884 * If the target process record shows that no 2885 * PMCs are attached to it, reclaim its space. 2886 */ 2887 2888 if (pp->pp_refcnt == 0) { 2889 pmc_remove_process_descriptor(pp); 2890 pmc_destroy_process_descriptor(pp); 2891 } 2892 } 2893 2894 cpu = curthread->td_oncpu; /* setup cpu for pmd_release() */ 2895 2896 } 2897 2898 /* 2899 * Release any MD resources 2900 */ 2901 (void) pcd->pcd_release_pmc(cpu, adjri, pm); 2902 2903 /* 2904 * Update row disposition 2905 */ 2906 2907 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) 2908 PMC_UNMARK_ROW_STANDALONE(ri); 2909 else 2910 PMC_UNMARK_ROW_THREAD(ri); 2911 2912 /* unlink from the owner's list */ 2913 if (pm->pm_owner) { 2914 LIST_REMOVE(pm, pm_next); 2915 pm->pm_owner = NULL; 2916 } 2917 } 2918 2919 /* 2920 * Register an owner and a pmc. 2921 */ 2922 2923 static int 2924 pmc_register_owner(struct proc *p, struct pmc *pmc) 2925 { 2926 struct pmc_owner *po; 2927 2928 sx_assert(&pmc_sx, SX_XLOCKED); 2929 2930 if ((po = pmc_find_owner_descriptor(p)) == NULL) 2931 if ((po = pmc_allocate_owner_descriptor(p)) == NULL) 2932 return ENOMEM; 2933 2934 KASSERT(pmc->pm_owner == NULL, 2935 ("[pmc,%d] attempting to own an initialized PMC", __LINE__)); 2936 pmc->pm_owner = po; 2937 2938 LIST_INSERT_HEAD(&po->po_pmcs, pmc, pm_next); 2939 2940 PROC_LOCK(p); 2941 p->p_flag |= P_HWPMC; 2942 PROC_UNLOCK(p); 2943 2944 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 2945 pmclog_process_pmcallocate(pmc); 2946 2947 PMCDBG2(PMC,REG,1, "register-owner pmc-owner=%p pmc=%p", 2948 po, pmc); 2949 2950 return 0; 2951 } 2952 2953 /* 2954 * Return the current row disposition: 2955 * == 0 => FREE 2956 * > 0 => PROCESS MODE 2957 * < 0 => SYSTEM MODE 2958 */ 2959 2960 int 2961 pmc_getrowdisp(int ri) 2962 { 2963 return pmc_pmcdisp[ri]; 2964 } 2965 2966 /* 2967 * Check if a PMC at row index 'ri' can be allocated to the current 2968 * process. 2969 * 2970 * Allocation can fail if: 2971 * - the current process is already being profiled by a PMC at index 'ri', 2972 * attached to it via OP_PMCATTACH. 2973 * - the current process has already allocated a PMC at index 'ri' 2974 * via OP_ALLOCATE. 2975 */ 2976 2977 static int 2978 pmc_can_allocate_rowindex(struct proc *p, unsigned int ri, int cpu) 2979 { 2980 enum pmc_mode mode; 2981 struct pmc *pm; 2982 struct pmc_owner *po; 2983 struct pmc_process *pp; 2984 2985 PMCDBG5(PMC,ALR,1, "can-allocate-rowindex proc=%p (%d, %s) ri=%d " 2986 "cpu=%d", p, p->p_pid, p->p_comm, ri, cpu); 2987 2988 /* 2989 * We shouldn't have already allocated a process-mode PMC at 2990 * row index 'ri'. 2991 * 2992 * We shouldn't have allocated a system-wide PMC on the same 2993 * CPU and same RI. 2994 */ 2995 if ((po = pmc_find_owner_descriptor(p)) != NULL) 2996 LIST_FOREACH(pm, &po->po_pmcs, pm_next) { 2997 if (PMC_TO_ROWINDEX(pm) == ri) { 2998 mode = PMC_TO_MODE(pm); 2999 if (PMC_IS_VIRTUAL_MODE(mode)) 3000 return EEXIST; 3001 if (PMC_IS_SYSTEM_MODE(mode) && 3002 (int) PMC_TO_CPU(pm) == cpu) 3003 return EEXIST; 3004 } 3005 } 3006 3007 /* 3008 * We also shouldn't be the target of any PMC at this index 3009 * since otherwise a PMC_ATTACH to ourselves will fail. 3010 */ 3011 if ((pp = pmc_find_process_descriptor(p, 0)) != NULL) 3012 if (pp->pp_pmcs[ri].pp_pmc) 3013 return EEXIST; 3014 3015 PMCDBG4(PMC,ALR,2, "can-allocate-rowindex proc=%p (%d, %s) ri=%d ok", 3016 p, p->p_pid, p->p_comm, ri); 3017 3018 return 0; 3019 } 3020 3021 /* 3022 * Check if a given PMC at row index 'ri' can be currently used in 3023 * mode 'mode'. 3024 */ 3025 3026 static int 3027 pmc_can_allocate_row(int ri, enum pmc_mode mode) 3028 { 3029 enum pmc_disp disp; 3030 3031 sx_assert(&pmc_sx, SX_XLOCKED); 3032 3033 PMCDBG2(PMC,ALR,1, "can-allocate-row ri=%d mode=%d", ri, mode); 3034 3035 if (PMC_IS_SYSTEM_MODE(mode)) 3036 disp = PMC_DISP_STANDALONE; 3037 else 3038 disp = PMC_DISP_THREAD; 3039 3040 /* 3041 * check disposition for PMC row 'ri': 3042 * 3043 * Expected disposition Row-disposition Result 3044 * 3045 * STANDALONE STANDALONE or FREE proceed 3046 * STANDALONE THREAD fail 3047 * THREAD THREAD or FREE proceed 3048 * THREAD STANDALONE fail 3049 */ 3050 3051 if (!PMC_ROW_DISP_IS_FREE(ri) && 3052 !(disp == PMC_DISP_THREAD && PMC_ROW_DISP_IS_THREAD(ri)) && 3053 !(disp == PMC_DISP_STANDALONE && PMC_ROW_DISP_IS_STANDALONE(ri))) 3054 return EBUSY; 3055 3056 /* 3057 * All OK 3058 */ 3059 3060 PMCDBG2(PMC,ALR,2, "can-allocate-row ri=%d mode=%d ok", ri, mode); 3061 3062 return 0; 3063 3064 } 3065 3066 /* 3067 * Find a PMC descriptor with user handle 'pmcid' for thread 'td'. 3068 */ 3069 3070 static struct pmc * 3071 pmc_find_pmc_descriptor_in_process(struct pmc_owner *po, pmc_id_t pmcid) 3072 { 3073 struct pmc *pm; 3074 3075 KASSERT(PMC_ID_TO_ROWINDEX(pmcid) < md->pmd_npmc, 3076 ("[pmc,%d] Illegal pmc index %d (max %d)", __LINE__, 3077 PMC_ID_TO_ROWINDEX(pmcid), md->pmd_npmc)); 3078 3079 LIST_FOREACH(pm, &po->po_pmcs, pm_next) 3080 if (pm->pm_id == pmcid) 3081 return pm; 3082 3083 return NULL; 3084 } 3085 3086 static int 3087 pmc_find_pmc(pmc_id_t pmcid, struct pmc **pmc) 3088 { 3089 3090 struct pmc *pm, *opm; 3091 struct pmc_owner *po; 3092 struct pmc_process *pp; 3093 3094 PMCDBG1(PMC,FND,1, "find-pmc id=%d", pmcid); 3095 if (PMC_ID_TO_ROWINDEX(pmcid) >= md->pmd_npmc) 3096 return (EINVAL); 3097 3098 if ((po = pmc_find_owner_descriptor(curthread->td_proc)) == NULL) { 3099 /* 3100 * In case of PMC_F_DESCENDANTS child processes we will not find 3101 * the current process in the owners hash list. Find the owner 3102 * process first and from there lookup the po. 3103 */ 3104 if ((pp = pmc_find_process_descriptor(curthread->td_proc, 3105 PMC_FLAG_NONE)) == NULL) { 3106 return ESRCH; 3107 } else { 3108 opm = pp->pp_pmcs[PMC_ID_TO_ROWINDEX(pmcid)].pp_pmc; 3109 if (opm == NULL) 3110 return ESRCH; 3111 if ((opm->pm_flags & (PMC_F_ATTACHED_TO_OWNER| 3112 PMC_F_DESCENDANTS)) != (PMC_F_ATTACHED_TO_OWNER| 3113 PMC_F_DESCENDANTS)) 3114 return ESRCH; 3115 po = opm->pm_owner; 3116 } 3117 } 3118 3119 if ((pm = pmc_find_pmc_descriptor_in_process(po, pmcid)) == NULL) 3120 return EINVAL; 3121 3122 PMCDBG2(PMC,FND,2, "find-pmc id=%d -> pmc=%p", pmcid, pm); 3123 3124 *pmc = pm; 3125 return 0; 3126 } 3127 3128 /* 3129 * Start a PMC. 3130 */ 3131 3132 static int 3133 pmc_start(struct pmc *pm) 3134 { 3135 enum pmc_mode mode; 3136 struct pmc_owner *po; 3137 struct pmc_binding pb; 3138 struct pmc_classdep *pcd; 3139 int adjri, error, cpu, ri; 3140 3141 KASSERT(pm != NULL, 3142 ("[pmc,%d] null pm", __LINE__)); 3143 3144 mode = PMC_TO_MODE(pm); 3145 ri = PMC_TO_ROWINDEX(pm); 3146 pcd = pmc_ri_to_classdep(md, ri, &adjri); 3147 3148 error = 0; 3149 3150 PMCDBG3(PMC,OPS,1, "start pmc=%p mode=%d ri=%d", pm, mode, ri); 3151 3152 po = pm->pm_owner; 3153 3154 /* 3155 * Disallow PMCSTART if a logfile is required but has not been 3156 * configured yet. 3157 */ 3158 if ((pm->pm_flags & PMC_F_NEEDS_LOGFILE) && 3159 (po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) 3160 return (EDOOFUS); /* programming error */ 3161 3162 /* 3163 * If this is a sampling mode PMC, log mapping information for 3164 * the kernel modules that are currently loaded. 3165 */ 3166 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 3167 pmc_log_kernel_mappings(pm); 3168 3169 if (PMC_IS_VIRTUAL_MODE(mode)) { 3170 3171 /* 3172 * If a PMCATTACH has never been done on this PMC, 3173 * attach it to its owner process. 3174 */ 3175 3176 if (LIST_EMPTY(&pm->pm_targets)) 3177 error = (pm->pm_flags & PMC_F_ATTACH_DONE) ? ESRCH : 3178 pmc_attach_process(po->po_owner, pm); 3179 3180 /* 3181 * If the PMC is attached to its owner, then force a context 3182 * switch to ensure that the MD state gets set correctly. 3183 */ 3184 3185 if (error == 0) { 3186 pm->pm_state = PMC_STATE_RUNNING; 3187 if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) 3188 pmc_force_context_switch(); 3189 } 3190 3191 return (error); 3192 } 3193 3194 3195 /* 3196 * A system-wide PMC. 3197 * 3198 * Add the owner to the global list if this is a system-wide 3199 * sampling PMC. 3200 */ 3201 3202 if (mode == PMC_MODE_SS) { 3203 /* 3204 * Log mapping information for all existing processes in the 3205 * system. Subsequent mappings are logged as they happen; 3206 * see pmc_process_mmap(). 3207 */ 3208 if (po->po_logprocmaps == 0) { 3209 pmc_log_all_process_mappings(po); 3210 po->po_logprocmaps = 1; 3211 } 3212 po->po_sscount++; 3213 if (po->po_sscount == 1) { 3214 atomic_add_rel_int(&pmc_ss_count, 1); 3215 CK_LIST_INSERT_HEAD(&pmc_ss_owners, po, po_ssnext); 3216 PMCDBG1(PMC,OPS,1, "po=%p in global list", po); 3217 } 3218 } 3219 3220 /* 3221 * Move to the CPU associated with this 3222 * PMC, and start the hardware. 3223 */ 3224 3225 pmc_save_cpu_binding(&pb); 3226 3227 cpu = PMC_TO_CPU(pm); 3228 3229 if (!pmc_cpu_is_active(cpu)) 3230 return (ENXIO); 3231 3232 pmc_select_cpu(cpu); 3233 3234 /* 3235 * global PMCs are configured at allocation time 3236 * so write out the initial value and start the PMC. 3237 */ 3238 3239 pm->pm_state = PMC_STATE_RUNNING; 3240 3241 critical_enter(); 3242 if ((error = pcd->pcd_write_pmc(cpu, adjri, 3243 PMC_IS_SAMPLING_MODE(mode) ? 3244 pm->pm_sc.pm_reloadcount : 3245 pm->pm_sc.pm_initial)) == 0) { 3246 /* If a sampling mode PMC, reset stalled state. */ 3247 if (PMC_IS_SAMPLING_MODE(mode)) 3248 pm->pm_pcpu_state[cpu].pps_stalled = 0; 3249 3250 /* Indicate that we desire this to run. Start it. */ 3251 pm->pm_pcpu_state[cpu].pps_cpustate = 1; 3252 error = pcd->pcd_start_pmc(cpu, adjri); 3253 } 3254 critical_exit(); 3255 3256 pmc_restore_cpu_binding(&pb); 3257 3258 return (error); 3259 } 3260 3261 /* 3262 * Stop a PMC. 3263 */ 3264 3265 static int 3266 pmc_stop(struct pmc *pm) 3267 { 3268 struct pmc_owner *po; 3269 struct pmc_binding pb; 3270 struct pmc_classdep *pcd; 3271 int adjri, cpu, error, ri; 3272 3273 KASSERT(pm != NULL, ("[pmc,%d] null pmc", __LINE__)); 3274 3275 PMCDBG3(PMC,OPS,1, "stop pmc=%p mode=%d ri=%d", pm, 3276 PMC_TO_MODE(pm), PMC_TO_ROWINDEX(pm)); 3277 3278 pm->pm_state = PMC_STATE_STOPPED; 3279 3280 /* 3281 * If the PMC is a virtual mode one, changing the state to 3282 * non-RUNNING is enough to ensure that the PMC never gets 3283 * scheduled. 3284 * 3285 * If this PMC is current running on a CPU, then it will 3286 * handled correctly at the time its target process is context 3287 * switched out. 3288 */ 3289 3290 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) 3291 return 0; 3292 3293 /* 3294 * A system-mode PMC. Move to the CPU associated with 3295 * this PMC, and stop the hardware. We update the 3296 * 'initial count' so that a subsequent PMCSTART will 3297 * resume counting from the current hardware count. 3298 */ 3299 3300 pmc_save_cpu_binding(&pb); 3301 3302 cpu = PMC_TO_CPU(pm); 3303 3304 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 3305 ("[pmc,%d] illegal cpu=%d", __LINE__, cpu)); 3306 3307 if (!pmc_cpu_is_active(cpu)) 3308 return ENXIO; 3309 3310 pmc_select_cpu(cpu); 3311 3312 ri = PMC_TO_ROWINDEX(pm); 3313 pcd = pmc_ri_to_classdep(md, ri, &adjri); 3314 3315 pm->pm_pcpu_state[cpu].pps_cpustate = 0; 3316 critical_enter(); 3317 if ((error = pcd->pcd_stop_pmc(cpu, adjri)) == 0) 3318 error = pcd->pcd_read_pmc(cpu, adjri, &pm->pm_sc.pm_initial); 3319 critical_exit(); 3320 3321 pmc_restore_cpu_binding(&pb); 3322 3323 po = pm->pm_owner; 3324 3325 /* remove this owner from the global list of SS PMC owners */ 3326 if (PMC_TO_MODE(pm) == PMC_MODE_SS) { 3327 po->po_sscount--; 3328 if (po->po_sscount == 0) { 3329 atomic_subtract_rel_int(&pmc_ss_count, 1); 3330 CK_LIST_REMOVE(po, po_ssnext); 3331 epoch_wait_preempt(global_epoch_preempt); 3332 PMCDBG1(PMC,OPS,2,"po=%p removed from global list", po); 3333 } 3334 } 3335 3336 return (error); 3337 } 3338 3339 static struct pmc_classdep * 3340 pmc_class_to_classdep(enum pmc_class class) 3341 { 3342 int n; 3343 3344 for (n = 0; n < md->pmd_nclass; n++) 3345 if (md->pmd_classdep[n].pcd_class == class) 3346 return (&md->pmd_classdep[n]); 3347 return (NULL); 3348 } 3349 3350 #if defined(HWPMC_DEBUG) && defined(KTR) 3351 static const char *pmc_op_to_name[] = { 3352 #undef __PMC_OP 3353 #define __PMC_OP(N, D) #N , 3354 __PMC_OPS() 3355 NULL 3356 }; 3357 #endif 3358 3359 /* 3360 * The syscall interface 3361 */ 3362 3363 #define PMC_GET_SX_XLOCK(...) do { \ 3364 sx_xlock(&pmc_sx); \ 3365 if (pmc_hook == NULL) { \ 3366 sx_xunlock(&pmc_sx); \ 3367 return __VA_ARGS__; \ 3368 } \ 3369 } while (0) 3370 3371 #define PMC_DOWNGRADE_SX() do { \ 3372 sx_downgrade(&pmc_sx); \ 3373 is_sx_downgraded = 1; \ 3374 } while (0) 3375 3376 static int 3377 pmc_syscall_handler(struct thread *td, void *syscall_args) 3378 { 3379 int error, is_sx_downgraded, op; 3380 struct pmc_syscall_args *c; 3381 void *pmclog_proc_handle; 3382 void *arg; 3383 3384 c = (struct pmc_syscall_args *)syscall_args; 3385 op = c->pmop_code; 3386 arg = c->pmop_data; 3387 /* PMC isn't set up yet */ 3388 if (pmc_hook == NULL) 3389 return (EINVAL); 3390 if (op == PMC_OP_CONFIGURELOG) { 3391 /* 3392 * We cannot create the logging process inside 3393 * pmclog_configure_log() because there is a LOR 3394 * between pmc_sx and process structure locks. 3395 * Instead, pre-create the process and ignite the loop 3396 * if everything is fine, otherwise direct the process 3397 * to exit. 3398 */ 3399 error = pmclog_proc_create(td, &pmclog_proc_handle); 3400 if (error != 0) 3401 goto done_syscall; 3402 } 3403 3404 PMC_GET_SX_XLOCK(ENOSYS); 3405 is_sx_downgraded = 0; 3406 PMCDBG3(MOD,PMS,1, "syscall op=%d \"%s\" arg=%p", op, 3407 pmc_op_to_name[op], arg); 3408 3409 error = 0; 3410 counter_u64_add(pmc_stats.pm_syscalls, 1); 3411 3412 switch (op) { 3413 3414 3415 /* 3416 * Configure a log file. 3417 * 3418 * XXX This OP will be reworked. 3419 */ 3420 3421 case PMC_OP_CONFIGURELOG: 3422 { 3423 struct proc *p; 3424 struct pmc *pm; 3425 struct pmc_owner *po; 3426 struct pmc_op_configurelog cl; 3427 3428 if ((error = copyin(arg, &cl, sizeof(cl))) != 0) { 3429 pmclog_proc_ignite(pmclog_proc_handle, NULL); 3430 break; 3431 } 3432 3433 /* mark this process as owning a log file */ 3434 p = td->td_proc; 3435 if ((po = pmc_find_owner_descriptor(p)) == NULL) 3436 if ((po = pmc_allocate_owner_descriptor(p)) == NULL) { 3437 pmclog_proc_ignite(pmclog_proc_handle, NULL); 3438 error = ENOMEM; 3439 break; 3440 } 3441 3442 /* 3443 * If a valid fd was passed in, try to configure that, 3444 * otherwise if 'fd' was less than zero and there was 3445 * a log file configured, flush its buffers and 3446 * de-configure it. 3447 */ 3448 if (cl.pm_logfd >= 0) { 3449 error = pmclog_configure_log(md, po, cl.pm_logfd); 3450 pmclog_proc_ignite(pmclog_proc_handle, error == 0 ? 3451 po : NULL); 3452 } else if (po->po_flags & PMC_PO_OWNS_LOGFILE) { 3453 pmclog_proc_ignite(pmclog_proc_handle, NULL); 3454 error = pmclog_close(po); 3455 if (error == 0) { 3456 LIST_FOREACH(pm, &po->po_pmcs, pm_next) 3457 if (pm->pm_flags & PMC_F_NEEDS_LOGFILE && 3458 pm->pm_state == PMC_STATE_RUNNING) 3459 pmc_stop(pm); 3460 error = pmclog_deconfigure_log(po); 3461 } 3462 } else { 3463 pmclog_proc_ignite(pmclog_proc_handle, NULL); 3464 error = EINVAL; 3465 } 3466 } 3467 break; 3468 3469 /* 3470 * Flush a log file. 3471 */ 3472 3473 case PMC_OP_FLUSHLOG: 3474 { 3475 struct pmc_owner *po; 3476 3477 sx_assert(&pmc_sx, SX_XLOCKED); 3478 3479 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 3480 error = EINVAL; 3481 break; 3482 } 3483 3484 error = pmclog_flush(po, 0); 3485 } 3486 break; 3487 3488 /* 3489 * Close a log file. 3490 */ 3491 3492 case PMC_OP_CLOSELOG: 3493 { 3494 struct pmc_owner *po; 3495 3496 sx_assert(&pmc_sx, SX_XLOCKED); 3497 3498 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 3499 error = EINVAL; 3500 break; 3501 } 3502 3503 error = pmclog_close(po); 3504 } 3505 break; 3506 3507 /* 3508 * Retrieve hardware configuration. 3509 */ 3510 3511 case PMC_OP_GETCPUINFO: /* CPU information */ 3512 { 3513 struct pmc_op_getcpuinfo gci; 3514 struct pmc_classinfo *pci; 3515 struct pmc_classdep *pcd; 3516 int cl; 3517 3518 memset(&gci, 0, sizeof(gci)); 3519 gci.pm_cputype = md->pmd_cputype; 3520 gci.pm_ncpu = pmc_cpu_max(); 3521 gci.pm_npmc = md->pmd_npmc; 3522 gci.pm_nclass = md->pmd_nclass; 3523 pci = gci.pm_classes; 3524 pcd = md->pmd_classdep; 3525 for (cl = 0; cl < md->pmd_nclass; cl++, pci++, pcd++) { 3526 pci->pm_caps = pcd->pcd_caps; 3527 pci->pm_class = pcd->pcd_class; 3528 pci->pm_width = pcd->pcd_width; 3529 pci->pm_num = pcd->pcd_num; 3530 } 3531 error = copyout(&gci, arg, sizeof(gci)); 3532 } 3533 break; 3534 3535 /* 3536 * Retrieve soft events list. 3537 */ 3538 case PMC_OP_GETDYNEVENTINFO: 3539 { 3540 enum pmc_class cl; 3541 enum pmc_event ev; 3542 struct pmc_op_getdyneventinfo *gei; 3543 struct pmc_dyn_event_descr dev; 3544 struct pmc_soft *ps; 3545 uint32_t nevent; 3546 3547 sx_assert(&pmc_sx, SX_LOCKED); 3548 3549 gei = (struct pmc_op_getdyneventinfo *) arg; 3550 3551 if ((error = copyin(&gei->pm_class, &cl, sizeof(cl))) != 0) 3552 break; 3553 3554 /* Only SOFT class is dynamic. */ 3555 if (cl != PMC_CLASS_SOFT) { 3556 error = EINVAL; 3557 break; 3558 } 3559 3560 nevent = 0; 3561 for (ev = PMC_EV_SOFT_FIRST; (int)ev <= PMC_EV_SOFT_LAST; ev++) { 3562 ps = pmc_soft_ev_acquire(ev); 3563 if (ps == NULL) 3564 continue; 3565 bcopy(&ps->ps_ev, &dev, sizeof(dev)); 3566 pmc_soft_ev_release(ps); 3567 3568 error = copyout(&dev, 3569 &gei->pm_events[nevent], 3570 sizeof(struct pmc_dyn_event_descr)); 3571 if (error != 0) 3572 break; 3573 nevent++; 3574 } 3575 if (error != 0) 3576 break; 3577 3578 error = copyout(&nevent, &gei->pm_nevent, 3579 sizeof(nevent)); 3580 } 3581 break; 3582 3583 /* 3584 * Get module statistics 3585 */ 3586 3587 case PMC_OP_GETDRIVERSTATS: 3588 { 3589 struct pmc_op_getdriverstats gms; 3590 #define CFETCH(a, b, field) a.field = counter_u64_fetch(b.field) 3591 CFETCH(gms, pmc_stats, pm_intr_ignored); 3592 CFETCH(gms, pmc_stats, pm_intr_processed); 3593 CFETCH(gms, pmc_stats, pm_intr_bufferfull); 3594 CFETCH(gms, pmc_stats, pm_syscalls); 3595 CFETCH(gms, pmc_stats, pm_syscall_errors); 3596 CFETCH(gms, pmc_stats, pm_buffer_requests); 3597 CFETCH(gms, pmc_stats, pm_buffer_requests_failed); 3598 CFETCH(gms, pmc_stats, pm_log_sweeps); 3599 #undef CFETCH 3600 error = copyout(&gms, arg, sizeof(gms)); 3601 } 3602 break; 3603 3604 3605 /* 3606 * Retrieve module version number 3607 */ 3608 3609 case PMC_OP_GETMODULEVERSION: 3610 { 3611 uint32_t cv, modv; 3612 3613 /* retrieve the client's idea of the ABI version */ 3614 if ((error = copyin(arg, &cv, sizeof(uint32_t))) != 0) 3615 break; 3616 /* don't service clients newer than our driver */ 3617 modv = PMC_VERSION; 3618 if ((cv & 0xFFFF0000) > (modv & 0xFFFF0000)) { 3619 error = EPROGMISMATCH; 3620 break; 3621 } 3622 error = copyout(&modv, arg, sizeof(int)); 3623 } 3624 break; 3625 3626 3627 /* 3628 * Retrieve the state of all the PMCs on a given 3629 * CPU. 3630 */ 3631 3632 case PMC_OP_GETPMCINFO: 3633 { 3634 int ari; 3635 struct pmc *pm; 3636 size_t pmcinfo_size; 3637 uint32_t cpu, n, npmc; 3638 struct pmc_owner *po; 3639 struct pmc_binding pb; 3640 struct pmc_classdep *pcd; 3641 struct pmc_info *p, *pmcinfo; 3642 struct pmc_op_getpmcinfo *gpi; 3643 3644 PMC_DOWNGRADE_SX(); 3645 3646 gpi = (struct pmc_op_getpmcinfo *) arg; 3647 3648 if ((error = copyin(&gpi->pm_cpu, &cpu, sizeof(cpu))) != 0) 3649 break; 3650 3651 if (cpu >= pmc_cpu_max()) { 3652 error = EINVAL; 3653 break; 3654 } 3655 3656 if (!pmc_cpu_is_active(cpu)) { 3657 error = ENXIO; 3658 break; 3659 } 3660 3661 /* switch to CPU 'cpu' */ 3662 pmc_save_cpu_binding(&pb); 3663 pmc_select_cpu(cpu); 3664 3665 npmc = md->pmd_npmc; 3666 3667 pmcinfo_size = npmc * sizeof(struct pmc_info); 3668 pmcinfo = malloc(pmcinfo_size, M_PMC, M_WAITOK | M_ZERO); 3669 3670 p = pmcinfo; 3671 3672 for (n = 0; n < md->pmd_npmc; n++, p++) { 3673 3674 pcd = pmc_ri_to_classdep(md, n, &ari); 3675 3676 KASSERT(pcd != NULL, 3677 ("[pmc,%d] null pcd ri=%d", __LINE__, n)); 3678 3679 if ((error = pcd->pcd_describe(cpu, ari, p, &pm)) != 0) 3680 break; 3681 3682 if (PMC_ROW_DISP_IS_STANDALONE(n)) 3683 p->pm_rowdisp = PMC_DISP_STANDALONE; 3684 else if (PMC_ROW_DISP_IS_THREAD(n)) 3685 p->pm_rowdisp = PMC_DISP_THREAD; 3686 else 3687 p->pm_rowdisp = PMC_DISP_FREE; 3688 3689 p->pm_ownerpid = -1; 3690 3691 if (pm == NULL) /* no PMC associated */ 3692 continue; 3693 3694 po = pm->pm_owner; 3695 3696 KASSERT(po->po_owner != NULL, 3697 ("[pmc,%d] pmc_owner had a null proc pointer", 3698 __LINE__)); 3699 3700 p->pm_ownerpid = po->po_owner->p_pid; 3701 p->pm_mode = PMC_TO_MODE(pm); 3702 p->pm_event = pm->pm_event; 3703 p->pm_flags = pm->pm_flags; 3704 3705 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 3706 p->pm_reloadcount = 3707 pm->pm_sc.pm_reloadcount; 3708 } 3709 3710 pmc_restore_cpu_binding(&pb); 3711 3712 /* now copy out the PMC info collected */ 3713 if (error == 0) 3714 error = copyout(pmcinfo, &gpi->pm_pmcs, pmcinfo_size); 3715 3716 free(pmcinfo, M_PMC); 3717 } 3718 break; 3719 3720 3721 /* 3722 * Set the administrative state of a PMC. I.e. whether 3723 * the PMC is to be used or not. 3724 */ 3725 3726 case PMC_OP_PMCADMIN: 3727 { 3728 int cpu, ri; 3729 enum pmc_state request; 3730 struct pmc_cpu *pc; 3731 struct pmc_hw *phw; 3732 struct pmc_op_pmcadmin pma; 3733 struct pmc_binding pb; 3734 3735 sx_assert(&pmc_sx, SX_XLOCKED); 3736 3737 KASSERT(td == curthread, 3738 ("[pmc,%d] td != curthread", __LINE__)); 3739 3740 error = priv_check(td, PRIV_PMC_MANAGE); 3741 if (error) 3742 break; 3743 3744 if ((error = copyin(arg, &pma, sizeof(pma))) != 0) 3745 break; 3746 3747 cpu = pma.pm_cpu; 3748 3749 if (cpu < 0 || cpu >= (int) pmc_cpu_max()) { 3750 error = EINVAL; 3751 break; 3752 } 3753 3754 if (!pmc_cpu_is_active(cpu)) { 3755 error = ENXIO; 3756 break; 3757 } 3758 3759 request = pma.pm_state; 3760 3761 if (request != PMC_STATE_DISABLED && 3762 request != PMC_STATE_FREE) { 3763 error = EINVAL; 3764 break; 3765 } 3766 3767 ri = pma.pm_pmc; /* pmc id == row index */ 3768 if (ri < 0 || ri >= (int) md->pmd_npmc) { 3769 error = EINVAL; 3770 break; 3771 } 3772 3773 /* 3774 * We can't disable a PMC with a row-index allocated 3775 * for process virtual PMCs. 3776 */ 3777 3778 if (PMC_ROW_DISP_IS_THREAD(ri) && 3779 request == PMC_STATE_DISABLED) { 3780 error = EBUSY; 3781 break; 3782 } 3783 3784 /* 3785 * otherwise, this PMC on this CPU is either free or 3786 * in system-wide mode. 3787 */ 3788 3789 pmc_save_cpu_binding(&pb); 3790 pmc_select_cpu(cpu); 3791 3792 pc = pmc_pcpu[cpu]; 3793 phw = pc->pc_hwpmcs[ri]; 3794 3795 /* 3796 * XXX do we need some kind of 'forced' disable? 3797 */ 3798 3799 if (phw->phw_pmc == NULL) { 3800 if (request == PMC_STATE_DISABLED && 3801 (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED)) { 3802 phw->phw_state &= ~PMC_PHW_FLAG_IS_ENABLED; 3803 PMC_MARK_ROW_STANDALONE(ri); 3804 } else if (request == PMC_STATE_FREE && 3805 (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0) { 3806 phw->phw_state |= PMC_PHW_FLAG_IS_ENABLED; 3807 PMC_UNMARK_ROW_STANDALONE(ri); 3808 } 3809 /* other cases are a no-op */ 3810 } else 3811 error = EBUSY; 3812 3813 pmc_restore_cpu_binding(&pb); 3814 } 3815 break; 3816 3817 3818 /* 3819 * Allocate a PMC. 3820 */ 3821 3822 case PMC_OP_PMCALLOCATE: 3823 { 3824 int adjri, n; 3825 u_int cpu; 3826 uint32_t caps; 3827 struct pmc *pmc; 3828 enum pmc_mode mode; 3829 struct pmc_hw *phw; 3830 struct pmc_binding pb; 3831 struct pmc_classdep *pcd; 3832 struct pmc_op_pmcallocate pa; 3833 3834 if ((error = copyin(arg, &pa, sizeof(pa))) != 0) 3835 break; 3836 3837 caps = pa.pm_caps; 3838 mode = pa.pm_mode; 3839 cpu = pa.pm_cpu; 3840 3841 if ((mode != PMC_MODE_SS && mode != PMC_MODE_SC && 3842 mode != PMC_MODE_TS && mode != PMC_MODE_TC) || 3843 (cpu != (u_int) PMC_CPU_ANY && cpu >= pmc_cpu_max())) { 3844 error = EINVAL; 3845 break; 3846 } 3847 3848 /* 3849 * Virtual PMCs should only ask for a default CPU. 3850 * System mode PMCs need to specify a non-default CPU. 3851 */ 3852 3853 if ((PMC_IS_VIRTUAL_MODE(mode) && cpu != (u_int) PMC_CPU_ANY) || 3854 (PMC_IS_SYSTEM_MODE(mode) && cpu == (u_int) PMC_CPU_ANY)) { 3855 error = EINVAL; 3856 break; 3857 } 3858 3859 /* 3860 * Check that an inactive CPU is not being asked for. 3861 */ 3862 3863 if (PMC_IS_SYSTEM_MODE(mode) && !pmc_cpu_is_active(cpu)) { 3864 error = ENXIO; 3865 break; 3866 } 3867 3868 /* 3869 * Refuse an allocation for a system-wide PMC if this 3870 * process has been jailed, or if this process lacks 3871 * super-user credentials and the sysctl tunable 3872 * 'security.bsd.unprivileged_syspmcs' is zero. 3873 */ 3874 3875 if (PMC_IS_SYSTEM_MODE(mode)) { 3876 if (jailed(curthread->td_ucred)) { 3877 error = EPERM; 3878 break; 3879 } 3880 if (!pmc_unprivileged_syspmcs) { 3881 error = priv_check(curthread, 3882 PRIV_PMC_SYSTEM); 3883 if (error) 3884 break; 3885 } 3886 } 3887 3888 /* 3889 * Look for valid values for 'pm_flags' 3890 */ 3891 3892 if ((pa.pm_flags & ~(PMC_F_DESCENDANTS | PMC_F_LOG_PROCCSW | 3893 PMC_F_LOG_PROCEXIT | PMC_F_CALLCHAIN | 3894 PMC_F_USERCALLCHAIN)) != 0) { 3895 error = EINVAL; 3896 break; 3897 } 3898 3899 /* PMC_F_USERCALLCHAIN is only valid with PMC_F_CALLCHAIN */ 3900 if ((pa.pm_flags & (PMC_F_CALLCHAIN | PMC_F_USERCALLCHAIN)) == 3901 PMC_F_USERCALLCHAIN) { 3902 error = EINVAL; 3903 break; 3904 } 3905 3906 /* PMC_F_USERCALLCHAIN is only valid for sampling mode */ 3907 if (pa.pm_flags & PMC_F_USERCALLCHAIN && 3908 mode != PMC_MODE_TS && mode != PMC_MODE_SS) { 3909 error = EINVAL; 3910 break; 3911 } 3912 3913 /* process logging options are not allowed for system PMCs */ 3914 if (PMC_IS_SYSTEM_MODE(mode) && (pa.pm_flags & 3915 (PMC_F_LOG_PROCCSW | PMC_F_LOG_PROCEXIT))) { 3916 error = EINVAL; 3917 break; 3918 } 3919 3920 /* 3921 * All sampling mode PMCs need to be able to interrupt the 3922 * CPU. 3923 */ 3924 if (PMC_IS_SAMPLING_MODE(mode)) 3925 caps |= PMC_CAP_INTERRUPT; 3926 3927 /* A valid class specifier should have been passed in. */ 3928 pcd = pmc_class_to_classdep(pa.pm_class); 3929 if (pcd == NULL) { 3930 error = EINVAL; 3931 break; 3932 } 3933 3934 /* The requested PMC capabilities should be feasible. */ 3935 if ((pcd->pcd_caps & caps) != caps) { 3936 error = EOPNOTSUPP; 3937 break; 3938 } 3939 3940 PMCDBG4(PMC,ALL,2, "event=%d caps=0x%x mode=%d cpu=%d", 3941 pa.pm_ev, caps, mode, cpu); 3942 3943 pmc = pmc_allocate_pmc_descriptor(); 3944 pmc->pm_id = PMC_ID_MAKE_ID(cpu,pa.pm_mode,pa.pm_class, 3945 PMC_ID_INVALID); 3946 pmc->pm_event = pa.pm_ev; 3947 pmc->pm_state = PMC_STATE_FREE; 3948 pmc->pm_caps = caps; 3949 pmc->pm_flags = pa.pm_flags; 3950 3951 /* XXX set lower bound on sampling for process counters */ 3952 if (PMC_IS_SAMPLING_MODE(mode)) { 3953 /* 3954 * Don't permit requested sample rate to be less than 1000 3955 */ 3956 if (pa.pm_count < 1000) 3957 log(LOG_WARNING, 3958 "pmcallocate: passed sample rate %ju - setting to 1000\n", 3959 (uintmax_t)pa.pm_count); 3960 pmc->pm_sc.pm_reloadcount = MAX(1000, pa.pm_count); 3961 } else 3962 pmc->pm_sc.pm_initial = pa.pm_count; 3963 3964 /* switch thread to CPU 'cpu' */ 3965 pmc_save_cpu_binding(&pb); 3966 3967 #define PMC_IS_SHAREABLE_PMC(cpu, n) \ 3968 (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_state & \ 3969 PMC_PHW_FLAG_IS_SHAREABLE) 3970 #define PMC_IS_UNALLOCATED(cpu, n) \ 3971 (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_pmc == NULL) 3972 3973 if (PMC_IS_SYSTEM_MODE(mode)) { 3974 pmc_select_cpu(cpu); 3975 for (n = pcd->pcd_ri; n < (int) md->pmd_npmc; n++) { 3976 pcd = pmc_ri_to_classdep(md, n, &adjri); 3977 if (pmc_can_allocate_row(n, mode) == 0 && 3978 pmc_can_allocate_rowindex( 3979 curthread->td_proc, n, cpu) == 0 && 3980 (PMC_IS_UNALLOCATED(cpu, n) || 3981 PMC_IS_SHAREABLE_PMC(cpu, n)) && 3982 pcd->pcd_allocate_pmc(cpu, adjri, pmc, 3983 &pa) == 0) 3984 break; 3985 } 3986 } else { 3987 /* Process virtual mode */ 3988 for (n = pcd->pcd_ri; n < (int) md->pmd_npmc; n++) { 3989 pcd = pmc_ri_to_classdep(md, n, &adjri); 3990 if (pmc_can_allocate_row(n, mode) == 0 && 3991 pmc_can_allocate_rowindex( 3992 curthread->td_proc, n, 3993 PMC_CPU_ANY) == 0 && 3994 pcd->pcd_allocate_pmc(curthread->td_oncpu, 3995 adjri, pmc, &pa) == 0) 3996 break; 3997 } 3998 } 3999 4000 #undef PMC_IS_UNALLOCATED 4001 #undef PMC_IS_SHAREABLE_PMC 4002 4003 pmc_restore_cpu_binding(&pb); 4004 4005 if (n == (int) md->pmd_npmc) { 4006 pmc_destroy_pmc_descriptor(pmc); 4007 pmc = NULL; 4008 error = EINVAL; 4009 break; 4010 } 4011 4012 /* Fill in the correct value in the ID field */ 4013 pmc->pm_id = PMC_ID_MAKE_ID(cpu,mode,pa.pm_class,n); 4014 4015 PMCDBG5(PMC,ALL,2, "ev=%d class=%d mode=%d n=%d -> pmcid=%x", 4016 pmc->pm_event, pa.pm_class, mode, n, pmc->pm_id); 4017 4018 /* Process mode PMCs with logging enabled need log files */ 4019 if (pmc->pm_flags & (PMC_F_LOG_PROCEXIT | PMC_F_LOG_PROCCSW)) 4020 pmc->pm_flags |= PMC_F_NEEDS_LOGFILE; 4021 4022 /* All system mode sampling PMCs require a log file */ 4023 if (PMC_IS_SAMPLING_MODE(mode) && PMC_IS_SYSTEM_MODE(mode)) 4024 pmc->pm_flags |= PMC_F_NEEDS_LOGFILE; 4025 4026 /* 4027 * Configure global pmc's immediately 4028 */ 4029 4030 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pmc))) { 4031 4032 pmc_save_cpu_binding(&pb); 4033 pmc_select_cpu(cpu); 4034 4035 phw = pmc_pcpu[cpu]->pc_hwpmcs[n]; 4036 pcd = pmc_ri_to_classdep(md, n, &adjri); 4037 4038 if ((phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0 || 4039 (error = pcd->pcd_config_pmc(cpu, adjri, pmc)) != 0) { 4040 (void) pcd->pcd_release_pmc(cpu, adjri, pmc); 4041 pmc_destroy_pmc_descriptor(pmc); 4042 pmc = NULL; 4043 pmc_restore_cpu_binding(&pb); 4044 error = EPERM; 4045 break; 4046 } 4047 4048 pmc_restore_cpu_binding(&pb); 4049 } 4050 4051 pmc->pm_state = PMC_STATE_ALLOCATED; 4052 pmc->pm_class = pa.pm_class; 4053 4054 /* 4055 * mark row disposition 4056 */ 4057 4058 if (PMC_IS_SYSTEM_MODE(mode)) 4059 PMC_MARK_ROW_STANDALONE(n); 4060 else 4061 PMC_MARK_ROW_THREAD(n); 4062 4063 /* 4064 * Register this PMC with the current thread as its owner. 4065 */ 4066 4067 if ((error = 4068 pmc_register_owner(curthread->td_proc, pmc)) != 0) { 4069 pmc_release_pmc_descriptor(pmc); 4070 pmc_destroy_pmc_descriptor(pmc); 4071 pmc = NULL; 4072 break; 4073 } 4074 4075 4076 /* 4077 * Return the allocated index. 4078 */ 4079 4080 pa.pm_pmcid = pmc->pm_id; 4081 4082 error = copyout(&pa, arg, sizeof(pa)); 4083 } 4084 break; 4085 4086 4087 /* 4088 * Attach a PMC to a process. 4089 */ 4090 4091 case PMC_OP_PMCATTACH: 4092 { 4093 struct pmc *pm; 4094 struct proc *p; 4095 struct pmc_op_pmcattach a; 4096 4097 sx_assert(&pmc_sx, SX_XLOCKED); 4098 4099 if ((error = copyin(arg, &a, sizeof(a))) != 0) 4100 break; 4101 4102 if (a.pm_pid < 0) { 4103 error = EINVAL; 4104 break; 4105 } else if (a.pm_pid == 0) 4106 a.pm_pid = td->td_proc->p_pid; 4107 4108 if ((error = pmc_find_pmc(a.pm_pmc, &pm)) != 0) 4109 break; 4110 4111 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) { 4112 error = EINVAL; 4113 break; 4114 } 4115 4116 /* PMCs may be (re)attached only when allocated or stopped */ 4117 if (pm->pm_state == PMC_STATE_RUNNING) { 4118 error = EBUSY; 4119 break; 4120 } else if (pm->pm_state != PMC_STATE_ALLOCATED && 4121 pm->pm_state != PMC_STATE_STOPPED) { 4122 error = EINVAL; 4123 break; 4124 } 4125 4126 /* lookup pid */ 4127 if ((p = pfind(a.pm_pid)) == NULL) { 4128 error = ESRCH; 4129 break; 4130 } 4131 4132 /* 4133 * Ignore processes that are working on exiting. 4134 */ 4135 if (p->p_flag & P_WEXIT) { 4136 error = ESRCH; 4137 PROC_UNLOCK(p); /* pfind() returns a locked process */ 4138 break; 4139 } 4140 4141 /* 4142 * we are allowed to attach a PMC to a process if 4143 * we can debug it. 4144 */ 4145 error = p_candebug(curthread, p); 4146 4147 PROC_UNLOCK(p); 4148 4149 if (error == 0) 4150 error = pmc_attach_process(p, pm); 4151 } 4152 break; 4153 4154 4155 /* 4156 * Detach an attached PMC from a process. 4157 */ 4158 4159 case PMC_OP_PMCDETACH: 4160 { 4161 struct pmc *pm; 4162 struct proc *p; 4163 struct pmc_op_pmcattach a; 4164 4165 if ((error = copyin(arg, &a, sizeof(a))) != 0) 4166 break; 4167 4168 if (a.pm_pid < 0) { 4169 error = EINVAL; 4170 break; 4171 } else if (a.pm_pid == 0) 4172 a.pm_pid = td->td_proc->p_pid; 4173 4174 if ((error = pmc_find_pmc(a.pm_pmc, &pm)) != 0) 4175 break; 4176 4177 if ((p = pfind(a.pm_pid)) == NULL) { 4178 error = ESRCH; 4179 break; 4180 } 4181 4182 /* 4183 * Treat processes that are in the process of exiting 4184 * as if they were not present. 4185 */ 4186 4187 if (p->p_flag & P_WEXIT) 4188 error = ESRCH; 4189 4190 PROC_UNLOCK(p); /* pfind() returns a locked process */ 4191 4192 if (error == 0) 4193 error = pmc_detach_process(p, pm); 4194 } 4195 break; 4196 4197 4198 /* 4199 * Retrieve the MSR number associated with the counter 4200 * 'pmc_id'. This allows processes to directly use RDPMC 4201 * instructions to read their PMCs, without the overhead of a 4202 * system call. 4203 */ 4204 4205 case PMC_OP_PMCGETMSR: 4206 { 4207 int adjri, ri; 4208 struct pmc *pm; 4209 struct pmc_target *pt; 4210 struct pmc_op_getmsr gm; 4211 struct pmc_classdep *pcd; 4212 4213 PMC_DOWNGRADE_SX(); 4214 4215 if ((error = copyin(arg, &gm, sizeof(gm))) != 0) 4216 break; 4217 4218 if ((error = pmc_find_pmc(gm.pm_pmcid, &pm)) != 0) 4219 break; 4220 4221 /* 4222 * The allocated PMC has to be a process virtual PMC, 4223 * i.e., of type MODE_T[CS]. Global PMCs can only be 4224 * read using the PMCREAD operation since they may be 4225 * allocated on a different CPU than the one we could 4226 * be running on at the time of the RDPMC instruction. 4227 * 4228 * The GETMSR operation is not allowed for PMCs that 4229 * are inherited across processes. 4230 */ 4231 4232 if (!PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)) || 4233 (pm->pm_flags & PMC_F_DESCENDANTS)) { 4234 error = EINVAL; 4235 break; 4236 } 4237 4238 /* 4239 * It only makes sense to use a RDPMC (or its 4240 * equivalent instruction on non-x86 architectures) on 4241 * a process that has allocated and attached a PMC to 4242 * itself. Conversely the PMC is only allowed to have 4243 * one process attached to it -- its owner. 4244 */ 4245 4246 if ((pt = LIST_FIRST(&pm->pm_targets)) == NULL || 4247 LIST_NEXT(pt, pt_next) != NULL || 4248 pt->pt_process->pp_proc != pm->pm_owner->po_owner) { 4249 error = EINVAL; 4250 break; 4251 } 4252 4253 ri = PMC_TO_ROWINDEX(pm); 4254 pcd = pmc_ri_to_classdep(md, ri, &adjri); 4255 4256 /* PMC class has no 'GETMSR' support */ 4257 if (pcd->pcd_get_msr == NULL) { 4258 error = ENOSYS; 4259 break; 4260 } 4261 4262 if ((error = (*pcd->pcd_get_msr)(adjri, &gm.pm_msr)) < 0) 4263 break; 4264 4265 if ((error = copyout(&gm, arg, sizeof(gm))) < 0) 4266 break; 4267 4268 /* 4269 * Mark our process as using MSRs. Update machine 4270 * state using a forced context switch. 4271 */ 4272 4273 pt->pt_process->pp_flags |= PMC_PP_ENABLE_MSR_ACCESS; 4274 pmc_force_context_switch(); 4275 4276 } 4277 break; 4278 4279 /* 4280 * Release an allocated PMC 4281 */ 4282 4283 case PMC_OP_PMCRELEASE: 4284 { 4285 pmc_id_t pmcid; 4286 struct pmc *pm; 4287 struct pmc_owner *po; 4288 struct pmc_op_simple sp; 4289 4290 /* 4291 * Find PMC pointer for the named PMC. 4292 * 4293 * Use pmc_release_pmc_descriptor() to switch off the 4294 * PMC, remove all its target threads, and remove the 4295 * PMC from its owner's list. 4296 * 4297 * Remove the owner record if this is the last PMC 4298 * owned. 4299 * 4300 * Free up space. 4301 */ 4302 4303 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 4304 break; 4305 4306 pmcid = sp.pm_pmcid; 4307 4308 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 4309 break; 4310 4311 po = pm->pm_owner; 4312 pmc_release_pmc_descriptor(pm); 4313 pmc_maybe_remove_owner(po); 4314 pmc_destroy_pmc_descriptor(pm); 4315 } 4316 break; 4317 4318 4319 /* 4320 * Read and/or write a PMC. 4321 */ 4322 4323 case PMC_OP_PMCRW: 4324 { 4325 int adjri; 4326 struct pmc *pm; 4327 uint32_t cpu, ri; 4328 pmc_value_t oldvalue; 4329 struct pmc_binding pb; 4330 struct pmc_op_pmcrw prw; 4331 struct pmc_classdep *pcd; 4332 struct pmc_op_pmcrw *pprw; 4333 4334 PMC_DOWNGRADE_SX(); 4335 4336 if ((error = copyin(arg, &prw, sizeof(prw))) != 0) 4337 break; 4338 4339 ri = 0; 4340 PMCDBG2(PMC,OPS,1, "rw id=%d flags=0x%x", prw.pm_pmcid, 4341 prw.pm_flags); 4342 4343 /* must have at least one flag set */ 4344 if ((prw.pm_flags & (PMC_F_OLDVALUE|PMC_F_NEWVALUE)) == 0) { 4345 error = EINVAL; 4346 break; 4347 } 4348 4349 /* locate pmc descriptor */ 4350 if ((error = pmc_find_pmc(prw.pm_pmcid, &pm)) != 0) 4351 break; 4352 4353 /* Can't read a PMC that hasn't been started. */ 4354 if (pm->pm_state != PMC_STATE_ALLOCATED && 4355 pm->pm_state != PMC_STATE_STOPPED && 4356 pm->pm_state != PMC_STATE_RUNNING) { 4357 error = EINVAL; 4358 break; 4359 } 4360 4361 /* writing a new value is allowed only for 'STOPPED' pmcs */ 4362 if (pm->pm_state == PMC_STATE_RUNNING && 4363 (prw.pm_flags & PMC_F_NEWVALUE)) { 4364 error = EBUSY; 4365 break; 4366 } 4367 4368 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) { 4369 4370 /* 4371 * If this PMC is attached to its owner (i.e., 4372 * the process requesting this operation) and 4373 * is running, then attempt to get an 4374 * upto-date reading from hardware for a READ. 4375 * Writes are only allowed when the PMC is 4376 * stopped, so only update the saved value 4377 * field. 4378 * 4379 * If the PMC is not running, or is not 4380 * attached to its owner, read/write to the 4381 * savedvalue field. 4382 */ 4383 4384 ri = PMC_TO_ROWINDEX(pm); 4385 pcd = pmc_ri_to_classdep(md, ri, &adjri); 4386 4387 mtx_pool_lock_spin(pmc_mtxpool, pm); 4388 cpu = curthread->td_oncpu; 4389 4390 if (prw.pm_flags & PMC_F_OLDVALUE) { 4391 if ((pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) && 4392 (pm->pm_state == PMC_STATE_RUNNING)) 4393 error = (*pcd->pcd_read_pmc)(cpu, adjri, 4394 &oldvalue); 4395 else 4396 oldvalue = pm->pm_gv.pm_savedvalue; 4397 } 4398 if (prw.pm_flags & PMC_F_NEWVALUE) 4399 pm->pm_gv.pm_savedvalue = prw.pm_value; 4400 4401 mtx_pool_unlock_spin(pmc_mtxpool, pm); 4402 4403 } else { /* System mode PMCs */ 4404 cpu = PMC_TO_CPU(pm); 4405 ri = PMC_TO_ROWINDEX(pm); 4406 pcd = pmc_ri_to_classdep(md, ri, &adjri); 4407 4408 if (!pmc_cpu_is_active(cpu)) { 4409 error = ENXIO; 4410 break; 4411 } 4412 4413 /* move this thread to CPU 'cpu' */ 4414 pmc_save_cpu_binding(&pb); 4415 pmc_select_cpu(cpu); 4416 4417 critical_enter(); 4418 /* save old value */ 4419 if (prw.pm_flags & PMC_F_OLDVALUE) 4420 if ((error = (*pcd->pcd_read_pmc)(cpu, adjri, 4421 &oldvalue))) 4422 goto error; 4423 /* write out new value */ 4424 if (prw.pm_flags & PMC_F_NEWVALUE) 4425 error = (*pcd->pcd_write_pmc)(cpu, adjri, 4426 prw.pm_value); 4427 error: 4428 critical_exit(); 4429 pmc_restore_cpu_binding(&pb); 4430 if (error) 4431 break; 4432 } 4433 4434 pprw = (struct pmc_op_pmcrw *) arg; 4435 4436 #ifdef HWPMC_DEBUG 4437 if (prw.pm_flags & PMC_F_NEWVALUE) 4438 PMCDBG3(PMC,OPS,2, "rw id=%d new %jx -> old %jx", 4439 ri, prw.pm_value, oldvalue); 4440 else if (prw.pm_flags & PMC_F_OLDVALUE) 4441 PMCDBG2(PMC,OPS,2, "rw id=%d -> old %jx", ri, oldvalue); 4442 #endif 4443 4444 /* return old value if requested */ 4445 if (prw.pm_flags & PMC_F_OLDVALUE) 4446 if ((error = copyout(&oldvalue, &pprw->pm_value, 4447 sizeof(prw.pm_value)))) 4448 break; 4449 4450 } 4451 break; 4452 4453 4454 /* 4455 * Set the sampling rate for a sampling mode PMC and the 4456 * initial count for a counting mode PMC. 4457 */ 4458 4459 case PMC_OP_PMCSETCOUNT: 4460 { 4461 struct pmc *pm; 4462 struct pmc_op_pmcsetcount sc; 4463 4464 PMC_DOWNGRADE_SX(); 4465 4466 if ((error = copyin(arg, &sc, sizeof(sc))) != 0) 4467 break; 4468 4469 if ((error = pmc_find_pmc(sc.pm_pmcid, &pm)) != 0) 4470 break; 4471 4472 if (pm->pm_state == PMC_STATE_RUNNING) { 4473 error = EBUSY; 4474 break; 4475 } 4476 4477 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) { 4478 /* 4479 * Don't permit requested sample rate to be less than 1000 4480 */ 4481 if (sc.pm_count < 1000) 4482 log(LOG_WARNING, 4483 "pmcsetcount: passed sample rate %ju - setting to 1000\n", 4484 (uintmax_t)sc.pm_count); 4485 pm->pm_sc.pm_reloadcount = MAX(1000, sc.pm_count); 4486 } else 4487 pm->pm_sc.pm_initial = sc.pm_count; 4488 } 4489 break; 4490 4491 4492 /* 4493 * Start a PMC. 4494 */ 4495 4496 case PMC_OP_PMCSTART: 4497 { 4498 pmc_id_t pmcid; 4499 struct pmc *pm; 4500 struct pmc_op_simple sp; 4501 4502 sx_assert(&pmc_sx, SX_XLOCKED); 4503 4504 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 4505 break; 4506 4507 pmcid = sp.pm_pmcid; 4508 4509 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 4510 break; 4511 4512 KASSERT(pmcid == pm->pm_id, 4513 ("[pmc,%d] pmcid %x != id %x", __LINE__, 4514 pm->pm_id, pmcid)); 4515 4516 if (pm->pm_state == PMC_STATE_RUNNING) /* already running */ 4517 break; 4518 else if (pm->pm_state != PMC_STATE_STOPPED && 4519 pm->pm_state != PMC_STATE_ALLOCATED) { 4520 error = EINVAL; 4521 break; 4522 } 4523 4524 error = pmc_start(pm); 4525 } 4526 break; 4527 4528 4529 /* 4530 * Stop a PMC. 4531 */ 4532 4533 case PMC_OP_PMCSTOP: 4534 { 4535 pmc_id_t pmcid; 4536 struct pmc *pm; 4537 struct pmc_op_simple sp; 4538 4539 PMC_DOWNGRADE_SX(); 4540 4541 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 4542 break; 4543 4544 pmcid = sp.pm_pmcid; 4545 4546 /* 4547 * Mark the PMC as inactive and invoke the MD stop 4548 * routines if needed. 4549 */ 4550 4551 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 4552 break; 4553 4554 KASSERT(pmcid == pm->pm_id, 4555 ("[pmc,%d] pmc id %x != pmcid %x", __LINE__, 4556 pm->pm_id, pmcid)); 4557 4558 if (pm->pm_state == PMC_STATE_STOPPED) /* already stopped */ 4559 break; 4560 else if (pm->pm_state != PMC_STATE_RUNNING) { 4561 error = EINVAL; 4562 break; 4563 } 4564 4565 error = pmc_stop(pm); 4566 } 4567 break; 4568 4569 4570 /* 4571 * Write a user supplied value to the log file. 4572 */ 4573 4574 case PMC_OP_WRITELOG: 4575 { 4576 struct pmc_op_writelog wl; 4577 struct pmc_owner *po; 4578 4579 PMC_DOWNGRADE_SX(); 4580 4581 if ((error = copyin(arg, &wl, sizeof(wl))) != 0) 4582 break; 4583 4584 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 4585 error = EINVAL; 4586 break; 4587 } 4588 4589 if ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) { 4590 error = EINVAL; 4591 break; 4592 } 4593 4594 error = pmclog_process_userlog(po, &wl); 4595 } 4596 break; 4597 4598 4599 default: 4600 error = EINVAL; 4601 break; 4602 } 4603 4604 if (is_sx_downgraded) 4605 sx_sunlock(&pmc_sx); 4606 else 4607 sx_xunlock(&pmc_sx); 4608 done_syscall: 4609 if (error) 4610 counter_u64_add(pmc_stats.pm_syscall_errors, 1); 4611 4612 return (error); 4613 } 4614 4615 /* 4616 * Helper functions 4617 */ 4618 4619 4620 /* 4621 * Mark the thread as needing callchain capture and post an AST. The 4622 * actual callchain capture will be done in a context where it is safe 4623 * to take page faults. 4624 */ 4625 4626 static void 4627 pmc_post_callchain_callback(void) 4628 { 4629 struct thread *td; 4630 4631 td = curthread; 4632 4633 /* 4634 * If there is multiple PMCs for the same interrupt ignore new post 4635 */ 4636 if (td->td_pflags & TDP_CALLCHAIN) 4637 return; 4638 4639 /* 4640 * Mark this thread as needing callchain capture. 4641 * `td->td_pflags' will be safe to touch because this thread 4642 * was in user space when it was interrupted. 4643 */ 4644 td->td_pflags |= TDP_CALLCHAIN; 4645 4646 /* 4647 * Don't let this thread migrate between CPUs until callchain 4648 * capture completes. 4649 */ 4650 sched_pin(); 4651 4652 return; 4653 } 4654 4655 /* 4656 * Find a free slot in the per-cpu array of samples and capture the 4657 * current callchain there. If a sample was successfully added, a bit 4658 * is set in mask 'pmc_cpumask' denoting that the DO_SAMPLES hook 4659 * needs to be invoked from the clock handler. 4660 * 4661 * This function is meant to be called from an NMI handler. It cannot 4662 * use any of the locking primitives supplied by the OS. 4663 */ 4664 4665 static int 4666 pmc_add_sample(ring_type_t ring, struct pmc *pm, struct trapframe *tf) 4667 { 4668 int error, cpu, callchaindepth, inuserspace; 4669 struct thread *td; 4670 struct pmc_sample *ps; 4671 struct pmc_samplebuffer *psb; 4672 4673 error = 0; 4674 4675 /* 4676 * Allocate space for a sample buffer. 4677 */ 4678 cpu = curcpu; 4679 psb = pmc_pcpu[cpu]->pc_sb[ring]; 4680 inuserspace = TRAPF_USERMODE(tf); 4681 ps = PMC_PROD_SAMPLE(psb); 4682 if (psb->ps_considx != psb->ps_prodidx && 4683 ps->ps_nsamples) { /* in use, reader hasn't caught up */ 4684 pm->pm_pcpu_state[cpu].pps_stalled = 1; 4685 counter_u64_add(pmc_stats.pm_intr_bufferfull, 1); 4686 PMCDBG6(SAM,INT,1,"(spc) cpu=%d pm=%p tf=%p um=%d wr=%d rd=%d", 4687 cpu, pm, (void *) tf, inuserspace, 4688 (int) (psb->ps_prodidx & pmc_sample_mask), 4689 (int) (psb->ps_considx & pmc_sample_mask)); 4690 callchaindepth = 1; 4691 error = ENOMEM; 4692 goto done; 4693 } 4694 4695 /* Fill in entry. */ 4696 PMCDBG6(SAM,INT,1,"cpu=%d pm=%p tf=%p um=%d wr=%d rd=%d", cpu, pm, 4697 (void *) tf, inuserspace, 4698 (int) (psb->ps_prodidx & pmc_sample_mask), 4699 (int) (psb->ps_considx & pmc_sample_mask)); 4700 4701 td = curthread; 4702 ps->ps_pmc = pm; 4703 ps->ps_td = td; 4704 ps->ps_pid = td->td_proc->p_pid; 4705 ps->ps_tid = td->td_tid; 4706 ps->ps_tsc = pmc_rdtsc(); 4707 ps->ps_ticks = ticks; 4708 ps->ps_cpu = cpu; 4709 ps->ps_flags = inuserspace ? PMC_CC_F_USERSPACE : 0; 4710 4711 callchaindepth = (pm->pm_flags & PMC_F_CALLCHAIN) ? 4712 pmc_callchaindepth : 1; 4713 4714 MPASS(ps->ps_pc != NULL); 4715 if (callchaindepth == 1) 4716 ps->ps_pc[0] = PMC_TRAPFRAME_TO_PC(tf); 4717 else { 4718 /* 4719 * Kernel stack traversals can be done immediately, 4720 * while we defer to an AST for user space traversals. 4721 */ 4722 if (!inuserspace) { 4723 callchaindepth = 4724 pmc_save_kernel_callchain(ps->ps_pc, 4725 callchaindepth, tf); 4726 } else { 4727 pmc_post_callchain_callback(); 4728 callchaindepth = PMC_USER_CALLCHAIN_PENDING; 4729 } 4730 } 4731 4732 ps->ps_nsamples = callchaindepth; /* mark entry as in use */ 4733 if (ring == PMC_UR) { 4734 ps->ps_nsamples_actual = callchaindepth; /* mark entry as in use */ 4735 ps->ps_nsamples = PMC_USER_CALLCHAIN_PENDING; 4736 } else 4737 ps->ps_nsamples = callchaindepth; /* mark entry as in use */ 4738 4739 KASSERT(counter_u64_fetch(pm->pm_runcount) >= 0, 4740 ("[pmc,%d] pm=%p runcount %ld", __LINE__, (void *) pm, 4741 (unsigned long)counter_u64_fetch(pm->pm_runcount))); 4742 4743 counter_u64_add(pm->pm_runcount, 1); /* hold onto PMC */ 4744 /* increment write pointer */ 4745 psb->ps_prodidx++; 4746 done: 4747 /* mark CPU as needing processing */ 4748 if (callchaindepth != PMC_USER_CALLCHAIN_PENDING) 4749 DPCPU_SET(pmc_sampled, 1); 4750 4751 return (error); 4752 } 4753 4754 /* 4755 * Interrupt processing. 4756 * 4757 * This function is meant to be called from an NMI handler. It cannot 4758 * use any of the locking primitives supplied by the OS. 4759 */ 4760 4761 int 4762 pmc_process_interrupt(int ring, struct pmc *pm, struct trapframe *tf) 4763 { 4764 struct thread *td; 4765 4766 td = curthread; 4767 if ((pm->pm_flags & PMC_F_USERCALLCHAIN) && 4768 (td->td_proc->p_flag & P_KPROC) == 0 && 4769 !TRAPF_USERMODE(tf)) { 4770 atomic_add_int(&td->td_pmcpend, 1); 4771 return (pmc_add_sample(PMC_UR, pm, tf)); 4772 } 4773 return (pmc_add_sample(ring, pm, tf)); 4774 } 4775 4776 /* 4777 * Capture a user call chain. This function will be called from ast() 4778 * before control returns to userland and before the process gets 4779 * rescheduled. 4780 */ 4781 4782 static void 4783 pmc_capture_user_callchain(int cpu, int ring, struct trapframe *tf) 4784 { 4785 struct pmc *pm; 4786 struct thread *td; 4787 struct pmc_sample *ps; 4788 struct pmc_samplebuffer *psb; 4789 uint64_t considx, prodidx; 4790 int nsamples, nrecords, pass, iter; 4791 #ifdef INVARIANTS 4792 int ncallchains; 4793 int nfree; 4794 int start_ticks = ticks; 4795 #endif 4796 psb = pmc_pcpu[cpu]->pc_sb[ring]; 4797 td = curthread; 4798 4799 KASSERT(td->td_pflags & TDP_CALLCHAIN, 4800 ("[pmc,%d] Retrieving callchain for thread that doesn't want it", 4801 __LINE__)); 4802 4803 #ifdef INVARIANTS 4804 ncallchains = 0; 4805 nfree = 0; 4806 #endif 4807 nrecords = INT_MAX; 4808 pass = 0; 4809 restart: 4810 if (ring == PMC_UR) 4811 nrecords = atomic_readandclear_32(&td->td_pmcpend); 4812 4813 for (iter = 0, considx = psb->ps_considx, prodidx = psb->ps_prodidx; 4814 considx < prodidx && iter < pmc_nsamples; considx++, iter++) { 4815 ps = PMC_CONS_SAMPLE_OFF(psb, considx); 4816 4817 /* 4818 * Iterate through all deferred callchain requests. 4819 * Walk from the current read pointer to the current 4820 * write pointer. 4821 */ 4822 4823 #ifdef INVARIANTS 4824 if (ps->ps_nsamples == PMC_SAMPLE_FREE) { 4825 nfree++; 4826 continue; 4827 } 4828 4829 if ((ps->ps_pmc == NULL) || 4830 (ps->ps_pmc->pm_state != PMC_STATE_RUNNING)) 4831 nfree++; 4832 #endif 4833 if (ps->ps_td != td || 4834 ps->ps_nsamples != PMC_USER_CALLCHAIN_PENDING || 4835 ps->ps_pmc->pm_state != PMC_STATE_RUNNING) 4836 continue; 4837 4838 KASSERT(ps->ps_cpu == cpu, 4839 ("[pmc,%d] cpu mismatch ps_cpu=%d pcpu=%d", __LINE__, 4840 ps->ps_cpu, PCPU_GET(cpuid))); 4841 4842 pm = ps->ps_pmc; 4843 4844 KASSERT(pm->pm_flags & PMC_F_CALLCHAIN, 4845 ("[pmc,%d] Retrieving callchain for PMC that doesn't " 4846 "want it", __LINE__)); 4847 4848 KASSERT(counter_u64_fetch(pm->pm_runcount) > 0, 4849 ("[pmc,%d] runcount %ld", __LINE__, (unsigned long)counter_u64_fetch(pm->pm_runcount))); 4850 4851 if (ring == PMC_UR) { 4852 nsamples = ps->ps_nsamples_actual; 4853 counter_u64_add(pmc_stats.pm_merges, 1); 4854 } else 4855 nsamples = 0; 4856 4857 /* 4858 * Retrieve the callchain and mark the sample buffer 4859 * as 'processable' by the timer tick sweep code. 4860 */ 4861 4862 #ifdef INVARIANTS 4863 ncallchains++; 4864 #endif 4865 4866 if (__predict_true(nsamples < pmc_callchaindepth - 1)) 4867 nsamples += pmc_save_user_callchain(ps->ps_pc + nsamples, 4868 pmc_callchaindepth - nsamples - 1, tf); 4869 4870 /* 4871 * We have to prevent hardclock from potentially overwriting 4872 * this sample between when we read the value and when we set 4873 * it 4874 */ 4875 spinlock_enter(); 4876 /* 4877 * Verify that the sample hasn't been dropped in the meantime 4878 */ 4879 if (ps->ps_nsamples == PMC_USER_CALLCHAIN_PENDING) { 4880 ps->ps_nsamples = nsamples; 4881 /* 4882 * If we couldn't get a sample, simply drop the reference 4883 */ 4884 if (nsamples == 0) 4885 counter_u64_add(pm->pm_runcount, -1); 4886 } 4887 spinlock_exit(); 4888 if (nrecords-- == 1) 4889 break; 4890 } 4891 if (__predict_false(ring == PMC_UR && td->td_pmcpend)) { 4892 if (pass == 0) { 4893 pass = 1; 4894 goto restart; 4895 } 4896 /* only collect samples for this part once */ 4897 td->td_pmcpend = 0; 4898 } 4899 4900 #ifdef INVARIANTS 4901 if ((ticks - start_ticks) > hz) 4902 log(LOG_ERR, "%s took %d ticks\n", __func__, (ticks - start_ticks)); 4903 #endif 4904 4905 /* mark CPU as needing processing */ 4906 DPCPU_SET(pmc_sampled, 1); 4907 } 4908 4909 /* 4910 * Process saved PC samples. 4911 */ 4912 4913 static void 4914 pmc_process_samples(int cpu, ring_type_t ring) 4915 { 4916 struct pmc *pm; 4917 int adjri, n; 4918 struct thread *td; 4919 struct pmc_owner *po; 4920 struct pmc_sample *ps; 4921 struct pmc_classdep *pcd; 4922 struct pmc_samplebuffer *psb; 4923 uint64_t delta; 4924 4925 KASSERT(PCPU_GET(cpuid) == cpu, 4926 ("[pmc,%d] not on the correct CPU pcpu=%d cpu=%d", __LINE__, 4927 PCPU_GET(cpuid), cpu)); 4928 4929 psb = pmc_pcpu[cpu]->pc_sb[ring]; 4930 delta = psb->ps_prodidx - psb->ps_considx; 4931 MPASS(delta <= pmc_nsamples); 4932 MPASS(psb->ps_considx <= psb->ps_prodidx); 4933 for (n = 0; psb->ps_considx < psb->ps_prodidx; psb->ps_considx++, n++) { 4934 ps = PMC_CONS_SAMPLE(psb); 4935 4936 if (__predict_false(ps->ps_nsamples == PMC_SAMPLE_FREE)) 4937 continue; 4938 pm = ps->ps_pmc; 4939 /* skip non-running samples */ 4940 if (pm->pm_state != PMC_STATE_RUNNING) 4941 goto entrydone; 4942 4943 KASSERT(counter_u64_fetch(pm->pm_runcount) > 0, 4944 ("[pmc,%d] pm=%p runcount %ld", __LINE__, (void *) pm, 4945 (unsigned long)counter_u64_fetch(pm->pm_runcount))); 4946 4947 po = pm->pm_owner; 4948 4949 KASSERT(PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)), 4950 ("[pmc,%d] pmc=%p non-sampling mode=%d", __LINE__, 4951 pm, PMC_TO_MODE(pm))); 4952 4953 4954 /* If there is a pending AST wait for completion */ 4955 if (ps->ps_nsamples == PMC_USER_CALLCHAIN_PENDING) { 4956 /* if we've been waiting more than 1 tick to 4957 * collect a callchain for this record then 4958 * drop it and move on. 4959 */ 4960 if (ticks - ps->ps_ticks > 1) { 4961 /* 4962 * track how often we hit this as it will 4963 * preferentially lose user samples 4964 * for long running system calls 4965 */ 4966 counter_u64_add(pmc_stats.pm_overwrites, 1); 4967 goto entrydone; 4968 } 4969 /* Need a rescan at a later time. */ 4970 DPCPU_SET(pmc_sampled, 1); 4971 break; 4972 } 4973 4974 PMCDBG6(SAM,OPS,1,"cpu=%d pm=%p n=%d fl=%x wr=%d rd=%d", cpu, 4975 pm, ps->ps_nsamples, ps->ps_flags, 4976 (int) (psb->ps_prodidx & pmc_sample_mask), 4977 (int) (psb->ps_considx & pmc_sample_mask)); 4978 4979 /* 4980 * If this is a process-mode PMC that is attached to 4981 * its owner, and if the PC is in user mode, update 4982 * profiling statistics like timer-based profiling 4983 * would have done. 4984 * 4985 * Otherwise, this is either a sampling-mode PMC that 4986 * is attached to a different process than its owner, 4987 * or a system-wide sampling PMC. Dispatch a log 4988 * entry to the PMC's owner process. 4989 */ 4990 if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) { 4991 if (ps->ps_flags & PMC_CC_F_USERSPACE) { 4992 td = FIRST_THREAD_IN_PROC(po->po_owner); 4993 addupc_intr(td, ps->ps_pc[0], 1); 4994 } 4995 } else 4996 pmclog_process_callchain(pm, ps); 4997 4998 entrydone: 4999 ps->ps_nsamples = 0; /* mark entry as free */ 5000 KASSERT(counter_u64_fetch(pm->pm_runcount) > 0, 5001 ("[pmc,%d] pm=%p runcount %ld", __LINE__, (void *) pm, 5002 (unsigned long)counter_u64_fetch(pm->pm_runcount))); 5003 5004 counter_u64_add(pm->pm_runcount, -1); 5005 } 5006 5007 counter_u64_add(pmc_stats.pm_log_sweeps, 1); 5008 5009 /* Do not re-enable stalled PMCs if we failed to process any samples */ 5010 if (n == 0) 5011 return; 5012 5013 /* 5014 * Restart any stalled sampling PMCs on this CPU. 5015 * 5016 * If the NMI handler sets the pm_stalled field of a PMC after 5017 * the check below, we'll end up processing the stalled PMC at 5018 * the next hardclock tick. 5019 */ 5020 for (n = 0; n < md->pmd_npmc; n++) { 5021 pcd = pmc_ri_to_classdep(md, n, &adjri); 5022 KASSERT(pcd != NULL, 5023 ("[pmc,%d] null pcd ri=%d", __LINE__, n)); 5024 (void) (*pcd->pcd_get_config)(cpu,adjri,&pm); 5025 5026 if (pm == NULL || /* !cfg'ed */ 5027 pm->pm_state != PMC_STATE_RUNNING || /* !active */ 5028 !PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)) || /* !sampling */ 5029 !pm->pm_pcpu_state[cpu].pps_cpustate || /* !desired */ 5030 !pm->pm_pcpu_state[cpu].pps_stalled) /* !stalled */ 5031 continue; 5032 5033 pm->pm_pcpu_state[cpu].pps_stalled = 0; 5034 (*pcd->pcd_start_pmc)(cpu, adjri); 5035 } 5036 } 5037 5038 /* 5039 * Event handlers. 5040 */ 5041 5042 /* 5043 * Handle a process exit. 5044 * 5045 * Remove this process from all hash tables. If this process 5046 * owned any PMCs, turn off those PMCs and deallocate them, 5047 * removing any associations with target processes. 5048 * 5049 * This function will be called by the last 'thread' of a 5050 * process. 5051 * 5052 * XXX This eventhandler gets called early in the exit process. 5053 * Consider using a 'hook' invocation from thread_exit() or equivalent 5054 * spot. Another negative is that kse_exit doesn't seem to call 5055 * exit1() [??]. 5056 * 5057 */ 5058 5059 static void 5060 pmc_process_exit(void *arg __unused, struct proc *p) 5061 { 5062 struct pmc *pm; 5063 int adjri, cpu; 5064 unsigned int ri; 5065 int is_using_hwpmcs; 5066 struct pmc_owner *po; 5067 struct pmc_process *pp; 5068 struct pmc_classdep *pcd; 5069 pmc_value_t newvalue, tmp; 5070 5071 PROC_LOCK(p); 5072 is_using_hwpmcs = p->p_flag & P_HWPMC; 5073 PROC_UNLOCK(p); 5074 5075 /* 5076 * Log a sysexit event to all SS PMC owners. 5077 */ 5078 PMC_EPOCH_ENTER(); 5079 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 5080 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 5081 pmclog_process_sysexit(po, p->p_pid); 5082 PMC_EPOCH_EXIT(); 5083 5084 if (!is_using_hwpmcs) 5085 return; 5086 5087 PMC_GET_SX_XLOCK(); 5088 PMCDBG3(PRC,EXT,1,"process-exit proc=%p (%d, %s)", p, p->p_pid, 5089 p->p_comm); 5090 5091 /* 5092 * Since this code is invoked by the last thread in an exiting 5093 * process, we would have context switched IN at some prior 5094 * point. However, with PREEMPTION, kernel mode context 5095 * switches may happen any time, so we want to disable a 5096 * context switch OUT till we get any PMCs targeting this 5097 * process off the hardware. 5098 * 5099 * We also need to atomically remove this process' 5100 * entry from our target process hash table, using 5101 * PMC_FLAG_REMOVE. 5102 */ 5103 PMCDBG3(PRC,EXT,1, "process-exit proc=%p (%d, %s)", p, p->p_pid, 5104 p->p_comm); 5105 5106 critical_enter(); /* no preemption */ 5107 5108 cpu = curthread->td_oncpu; 5109 5110 if ((pp = pmc_find_process_descriptor(p, 5111 PMC_FLAG_REMOVE)) != NULL) { 5112 5113 PMCDBG2(PRC,EXT,2, 5114 "process-exit proc=%p pmc-process=%p", p, pp); 5115 5116 /* 5117 * The exiting process could the target of 5118 * some PMCs which will be running on 5119 * currently executing CPU. 5120 * 5121 * We need to turn these PMCs off like we 5122 * would do at context switch OUT time. 5123 */ 5124 for (ri = 0; ri < md->pmd_npmc; ri++) { 5125 5126 /* 5127 * Pick up the pmc pointer from hardware 5128 * state similar to the CSW_OUT code. 5129 */ 5130 pm = NULL; 5131 5132 pcd = pmc_ri_to_classdep(md, ri, &adjri); 5133 5134 (void) (*pcd->pcd_get_config)(cpu, adjri, &pm); 5135 5136 PMCDBG2(PRC,EXT,2, "ri=%d pm=%p", ri, pm); 5137 5138 if (pm == NULL || 5139 !PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) 5140 continue; 5141 5142 PMCDBG4(PRC,EXT,2, "ppmcs[%d]=%p pm=%p " 5143 "state=%d", ri, pp->pp_pmcs[ri].pp_pmc, 5144 pm, pm->pm_state); 5145 5146 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 5147 ("[pmc,%d] ri mismatch pmc(%d) ri(%d)", 5148 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 5149 5150 KASSERT(pm == pp->pp_pmcs[ri].pp_pmc, 5151 ("[pmc,%d] pm %p != pp_pmcs[%d] %p", 5152 __LINE__, pm, ri, pp->pp_pmcs[ri].pp_pmc)); 5153 5154 KASSERT(counter_u64_fetch(pm->pm_runcount) > 0, 5155 ("[pmc,%d] bad runcount ri %d rc %ld", 5156 __LINE__, ri, (unsigned long)counter_u64_fetch(pm->pm_runcount))); 5157 5158 /* 5159 * Change desired state, and then stop if not 5160 * stalled. This two-step dance should avoid 5161 * race conditions where an interrupt re-enables 5162 * the PMC after this code has already checked 5163 * the pm_stalled flag. 5164 */ 5165 if (pm->pm_pcpu_state[cpu].pps_cpustate) { 5166 pm->pm_pcpu_state[cpu].pps_cpustate = 0; 5167 if (!pm->pm_pcpu_state[cpu].pps_stalled) { 5168 (void) pcd->pcd_stop_pmc(cpu, adjri); 5169 5170 if (PMC_TO_MODE(pm) == PMC_MODE_TC) { 5171 pcd->pcd_read_pmc(cpu, adjri, 5172 &newvalue); 5173 tmp = newvalue - 5174 PMC_PCPU_SAVED(cpu,ri); 5175 5176 mtx_pool_lock_spin(pmc_mtxpool, 5177 pm); 5178 pm->pm_gv.pm_savedvalue += tmp; 5179 pp->pp_pmcs[ri].pp_pmcval += 5180 tmp; 5181 mtx_pool_unlock_spin( 5182 pmc_mtxpool, pm); 5183 } 5184 } 5185 } 5186 5187 KASSERT((int64_t) counter_u64_fetch(pm->pm_runcount) > 0, 5188 ("[pmc,%d] runcount is %d", __LINE__, ri)); 5189 5190 counter_u64_add(pm->pm_runcount, -1); 5191 5192 (void) pcd->pcd_config_pmc(cpu, adjri, NULL); 5193 } 5194 5195 /* 5196 * Inform the MD layer of this pseudo "context switch 5197 * out" 5198 */ 5199 (void) md->pmd_switch_out(pmc_pcpu[cpu], pp); 5200 5201 critical_exit(); /* ok to be pre-empted now */ 5202 5203 /* 5204 * Unlink this process from the PMCs that are 5205 * targeting it. This will send a signal to 5206 * all PMC owner's whose PMCs are orphaned. 5207 * 5208 * Log PMC value at exit time if requested. 5209 */ 5210 for (ri = 0; ri < md->pmd_npmc; ri++) 5211 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) { 5212 if (pm->pm_flags & PMC_F_NEEDS_LOGFILE && 5213 PMC_IS_COUNTING_MODE(PMC_TO_MODE(pm))) 5214 pmclog_process_procexit(pm, pp); 5215 pmc_unlink_target_process(pm, pp); 5216 } 5217 free(pp, M_PMC); 5218 5219 } else 5220 critical_exit(); /* pp == NULL */ 5221 5222 5223 /* 5224 * If the process owned PMCs, free them up and free up 5225 * memory. 5226 */ 5227 if ((po = pmc_find_owner_descriptor(p)) != NULL) { 5228 pmc_remove_owner(po); 5229 pmc_destroy_owner_descriptor(po); 5230 } 5231 5232 sx_xunlock(&pmc_sx); 5233 } 5234 5235 /* 5236 * Handle a process fork. 5237 * 5238 * If the parent process 'p1' is under HWPMC monitoring, then copy 5239 * over any attached PMCs that have 'do_descendants' semantics. 5240 */ 5241 5242 static void 5243 pmc_process_fork(void *arg __unused, struct proc *p1, struct proc *newproc, 5244 int flags) 5245 { 5246 int is_using_hwpmcs; 5247 unsigned int ri; 5248 uint32_t do_descendants; 5249 struct pmc *pm; 5250 struct pmc_owner *po; 5251 struct pmc_process *ppnew, *ppold; 5252 5253 (void) flags; /* unused parameter */ 5254 5255 PROC_LOCK(p1); 5256 is_using_hwpmcs = p1->p_flag & P_HWPMC; 5257 PROC_UNLOCK(p1); 5258 5259 /* 5260 * If there are system-wide sampling PMCs active, we need to 5261 * log all fork events to their owner's logs. 5262 */ 5263 PMC_EPOCH_ENTER(); 5264 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 5265 if (po->po_flags & PMC_PO_OWNS_LOGFILE) { 5266 pmclog_process_procfork(po, p1->p_pid, newproc->p_pid); 5267 pmclog_process_proccreate(po, newproc, 1); 5268 } 5269 PMC_EPOCH_EXIT(); 5270 5271 if (!is_using_hwpmcs) 5272 return; 5273 5274 PMC_GET_SX_XLOCK(); 5275 PMCDBG4(PMC,FRK,1, "process-fork proc=%p (%d, %s) -> %p", p1, 5276 p1->p_pid, p1->p_comm, newproc); 5277 5278 /* 5279 * If the parent process (curthread->td_proc) is a 5280 * target of any PMCs, look for PMCs that are to be 5281 * inherited, and link these into the new process 5282 * descriptor. 5283 */ 5284 if ((ppold = pmc_find_process_descriptor(curthread->td_proc, 5285 PMC_FLAG_NONE)) == NULL) 5286 goto done; /* nothing to do */ 5287 5288 do_descendants = 0; 5289 for (ri = 0; ri < md->pmd_npmc; ri++) 5290 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL) 5291 do_descendants |= pm->pm_flags & PMC_F_DESCENDANTS; 5292 if (do_descendants == 0) /* nothing to do */ 5293 goto done; 5294 5295 /* 5296 * Now mark the new process as being tracked by this driver. 5297 */ 5298 PROC_LOCK(newproc); 5299 newproc->p_flag |= P_HWPMC; 5300 PROC_UNLOCK(newproc); 5301 5302 /* allocate a descriptor for the new process */ 5303 if ((ppnew = pmc_find_process_descriptor(newproc, 5304 PMC_FLAG_ALLOCATE)) == NULL) 5305 goto done; 5306 5307 /* 5308 * Run through all PMCs that were targeting the old process 5309 * and which specified F_DESCENDANTS and attach them to the 5310 * new process. 5311 * 5312 * Log the fork event to all owners of PMCs attached to this 5313 * process, if not already logged. 5314 */ 5315 for (ri = 0; ri < md->pmd_npmc; ri++) 5316 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL && 5317 (pm->pm_flags & PMC_F_DESCENDANTS)) { 5318 pmc_link_target_process(pm, ppnew); 5319 po = pm->pm_owner; 5320 if (po->po_sscount == 0 && 5321 po->po_flags & PMC_PO_OWNS_LOGFILE) 5322 pmclog_process_procfork(po, p1->p_pid, 5323 newproc->p_pid); 5324 } 5325 5326 done: 5327 sx_xunlock(&pmc_sx); 5328 } 5329 5330 static void 5331 pmc_process_threadcreate(struct thread *td) 5332 { 5333 struct pmc_owner *po; 5334 5335 PMC_EPOCH_ENTER(); 5336 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 5337 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 5338 pmclog_process_threadcreate(po, td, 1); 5339 PMC_EPOCH_EXIT(); 5340 } 5341 5342 static void 5343 pmc_process_threadexit(struct thread *td) 5344 { 5345 struct pmc_owner *po; 5346 5347 PMC_EPOCH_ENTER(); 5348 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 5349 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 5350 pmclog_process_threadexit(po, td); 5351 PMC_EPOCH_EXIT(); 5352 } 5353 5354 static void 5355 pmc_process_proccreate(struct proc *p) 5356 { 5357 struct pmc_owner *po; 5358 5359 PMC_EPOCH_ENTER(); 5360 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 5361 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 5362 pmclog_process_proccreate(po, p, 1 /* sync */); 5363 PMC_EPOCH_EXIT(); 5364 } 5365 5366 static void 5367 pmc_process_allproc(struct pmc *pm) 5368 { 5369 struct pmc_owner *po; 5370 struct thread *td; 5371 struct proc *p; 5372 5373 po = pm->pm_owner; 5374 if ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) 5375 return; 5376 sx_slock(&allproc_lock); 5377 FOREACH_PROC_IN_SYSTEM(p) { 5378 pmclog_process_proccreate(po, p, 0 /* sync */); 5379 PROC_LOCK(p); 5380 FOREACH_THREAD_IN_PROC(p, td) 5381 pmclog_process_threadcreate(po, td, 0 /* sync */); 5382 PROC_UNLOCK(p); 5383 } 5384 sx_sunlock(&allproc_lock); 5385 pmclog_flush(po, 0); 5386 } 5387 5388 static void 5389 pmc_kld_load(void *arg __unused, linker_file_t lf) 5390 { 5391 struct pmc_owner *po; 5392 5393 /* 5394 * Notify owners of system sampling PMCs about KLD operations. 5395 */ 5396 PMC_EPOCH_ENTER(); 5397 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 5398 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 5399 pmclog_process_map_in(po, (pid_t) -1, 5400 (uintfptr_t) lf->address, lf->filename); 5401 PMC_EPOCH_EXIT(); 5402 5403 /* 5404 * TODO: Notify owners of (all) process-sampling PMCs too. 5405 */ 5406 } 5407 5408 static void 5409 pmc_kld_unload(void *arg __unused, const char *filename __unused, 5410 caddr_t address, size_t size) 5411 { 5412 struct pmc_owner *po; 5413 5414 PMC_EPOCH_ENTER(); 5415 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 5416 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 5417 pmclog_process_map_out(po, (pid_t) -1, 5418 (uintfptr_t) address, (uintfptr_t) address + size); 5419 PMC_EPOCH_EXIT(); 5420 5421 /* 5422 * TODO: Notify owners of process-sampling PMCs. 5423 */ 5424 } 5425 5426 /* 5427 * initialization 5428 */ 5429 static const char * 5430 pmc_name_of_pmcclass(enum pmc_class class) 5431 { 5432 5433 switch (class) { 5434 #undef __PMC_CLASS 5435 #define __PMC_CLASS(S,V,D) \ 5436 case PMC_CLASS_##S: \ 5437 return #S; 5438 __PMC_CLASSES(); 5439 default: 5440 return ("<unknown>"); 5441 } 5442 } 5443 5444 /* 5445 * Base class initializer: allocate structure and set default classes. 5446 */ 5447 struct pmc_mdep * 5448 pmc_mdep_alloc(int nclasses) 5449 { 5450 struct pmc_mdep *md; 5451 int n; 5452 5453 /* SOFT + md classes */ 5454 n = 1 + nclasses; 5455 md = malloc(sizeof(struct pmc_mdep) + n * 5456 sizeof(struct pmc_classdep), M_PMC, M_WAITOK|M_ZERO); 5457 md->pmd_nclass = n; 5458 5459 /* Add base class. */ 5460 pmc_soft_initialize(md); 5461 return md; 5462 } 5463 5464 void 5465 pmc_mdep_free(struct pmc_mdep *md) 5466 { 5467 pmc_soft_finalize(md); 5468 free(md, M_PMC); 5469 } 5470 5471 static int 5472 generic_switch_in(struct pmc_cpu *pc, struct pmc_process *pp) 5473 { 5474 (void) pc; (void) pp; 5475 5476 return (0); 5477 } 5478 5479 static int 5480 generic_switch_out(struct pmc_cpu *pc, struct pmc_process *pp) 5481 { 5482 (void) pc; (void) pp; 5483 5484 return (0); 5485 } 5486 5487 static struct pmc_mdep * 5488 pmc_generic_cpu_initialize(void) 5489 { 5490 struct pmc_mdep *md; 5491 5492 md = pmc_mdep_alloc(0); 5493 5494 md->pmd_cputype = PMC_CPU_GENERIC; 5495 5496 md->pmd_pcpu_init = NULL; 5497 md->pmd_pcpu_fini = NULL; 5498 md->pmd_switch_in = generic_switch_in; 5499 md->pmd_switch_out = generic_switch_out; 5500 5501 return (md); 5502 } 5503 5504 static void 5505 pmc_generic_cpu_finalize(struct pmc_mdep *md) 5506 { 5507 (void) md; 5508 } 5509 5510 5511 static int 5512 pmc_initialize(void) 5513 { 5514 int c, cpu, error, n, ri; 5515 unsigned int maxcpu, domain; 5516 struct pcpu *pc; 5517 struct pmc_binding pb; 5518 struct pmc_sample *ps; 5519 struct pmc_classdep *pcd; 5520 struct pmc_samplebuffer *sb; 5521 5522 md = NULL; 5523 error = 0; 5524 5525 pmc_stats.pm_intr_ignored = counter_u64_alloc(M_WAITOK); 5526 pmc_stats.pm_intr_processed = counter_u64_alloc(M_WAITOK); 5527 pmc_stats.pm_intr_bufferfull = counter_u64_alloc(M_WAITOK); 5528 pmc_stats.pm_syscalls = counter_u64_alloc(M_WAITOK); 5529 pmc_stats.pm_syscall_errors = counter_u64_alloc(M_WAITOK); 5530 pmc_stats.pm_buffer_requests = counter_u64_alloc(M_WAITOK); 5531 pmc_stats.pm_buffer_requests_failed = counter_u64_alloc(M_WAITOK); 5532 pmc_stats.pm_log_sweeps = counter_u64_alloc(M_WAITOK); 5533 pmc_stats.pm_merges = counter_u64_alloc(M_WAITOK); 5534 pmc_stats.pm_overwrites = counter_u64_alloc(M_WAITOK); 5535 5536 #ifdef HWPMC_DEBUG 5537 /* parse debug flags first */ 5538 if (TUNABLE_STR_FETCH(PMC_SYSCTL_NAME_PREFIX "debugflags", 5539 pmc_debugstr, sizeof(pmc_debugstr))) 5540 pmc_debugflags_parse(pmc_debugstr, 5541 pmc_debugstr+strlen(pmc_debugstr)); 5542 #endif 5543 5544 PMCDBG1(MOD,INI,0, "PMC Initialize (version %x)", PMC_VERSION); 5545 5546 /* check kernel version */ 5547 if (pmc_kernel_version != PMC_VERSION) { 5548 if (pmc_kernel_version == 0) 5549 printf("hwpmc: this kernel has not been compiled with " 5550 "'options HWPMC_HOOKS'.\n"); 5551 else 5552 printf("hwpmc: kernel version (0x%x) does not match " 5553 "module version (0x%x).\n", pmc_kernel_version, 5554 PMC_VERSION); 5555 return EPROGMISMATCH; 5556 } 5557 5558 /* 5559 * check sysctl parameters 5560 */ 5561 5562 if (pmc_hashsize <= 0) { 5563 (void) printf("hwpmc: tunable \"hashsize\"=%d must be " 5564 "greater than zero.\n", pmc_hashsize); 5565 pmc_hashsize = PMC_HASH_SIZE; 5566 } 5567 5568 if (pmc_nsamples <= 0 || pmc_nsamples > 65535) { 5569 (void) printf("hwpmc: tunable \"nsamples\"=%d out of " 5570 "range.\n", pmc_nsamples); 5571 pmc_nsamples = PMC_NSAMPLES; 5572 } 5573 pmc_sample_mask = pmc_nsamples-1; 5574 5575 if (pmc_callchaindepth <= 0 || 5576 pmc_callchaindepth > PMC_CALLCHAIN_DEPTH_MAX) { 5577 (void) printf("hwpmc: tunable \"callchaindepth\"=%d out of " 5578 "range - using %d.\n", pmc_callchaindepth, 5579 PMC_CALLCHAIN_DEPTH_MAX); 5580 pmc_callchaindepth = PMC_CALLCHAIN_DEPTH_MAX; 5581 } 5582 5583 md = pmc_md_initialize(); 5584 if (md == NULL) { 5585 /* Default to generic CPU. */ 5586 md = pmc_generic_cpu_initialize(); 5587 if (md == NULL) 5588 return (ENOSYS); 5589 } 5590 5591 KASSERT(md->pmd_nclass >= 1 && md->pmd_npmc >= 1, 5592 ("[pmc,%d] no classes or pmcs", __LINE__)); 5593 5594 /* Compute the map from row-indices to classdep pointers. */ 5595 pmc_rowindex_to_classdep = malloc(sizeof(struct pmc_classdep *) * 5596 md->pmd_npmc, M_PMC, M_WAITOK|M_ZERO); 5597 5598 for (n = 0; n < md->pmd_npmc; n++) 5599 pmc_rowindex_to_classdep[n] = NULL; 5600 for (ri = c = 0; c < md->pmd_nclass; c++) { 5601 pcd = &md->pmd_classdep[c]; 5602 for (n = 0; n < pcd->pcd_num; n++, ri++) 5603 pmc_rowindex_to_classdep[ri] = pcd; 5604 } 5605 5606 KASSERT(ri == md->pmd_npmc, 5607 ("[pmc,%d] npmc miscomputed: ri=%d, md->npmc=%d", __LINE__, 5608 ri, md->pmd_npmc)); 5609 5610 maxcpu = pmc_cpu_max(); 5611 5612 /* allocate space for the per-cpu array */ 5613 pmc_pcpu = malloc(maxcpu * sizeof(struct pmc_cpu *), M_PMC, 5614 M_WAITOK|M_ZERO); 5615 5616 /* per-cpu 'saved values' for managing process-mode PMCs */ 5617 pmc_pcpu_saved = malloc(sizeof(pmc_value_t) * maxcpu * md->pmd_npmc, 5618 M_PMC, M_WAITOK); 5619 5620 /* Perform CPU-dependent initialization. */ 5621 pmc_save_cpu_binding(&pb); 5622 error = 0; 5623 for (cpu = 0; error == 0 && cpu < maxcpu; cpu++) { 5624 if (!pmc_cpu_is_active(cpu)) 5625 continue; 5626 pmc_select_cpu(cpu); 5627 pmc_pcpu[cpu] = malloc(sizeof(struct pmc_cpu) + 5628 md->pmd_npmc * sizeof(struct pmc_hw *), M_PMC, 5629 M_WAITOK|M_ZERO); 5630 if (md->pmd_pcpu_init) 5631 error = md->pmd_pcpu_init(md, cpu); 5632 for (n = 0; error == 0 && n < md->pmd_nclass; n++) 5633 error = md->pmd_classdep[n].pcd_pcpu_init(md, cpu); 5634 } 5635 pmc_restore_cpu_binding(&pb); 5636 5637 if (error) 5638 return (error); 5639 5640 /* allocate space for the sample array */ 5641 for (cpu = 0; cpu < maxcpu; cpu++) { 5642 if (!pmc_cpu_is_active(cpu)) 5643 continue; 5644 pc = pcpu_find(cpu); 5645 domain = pc->pc_domain; 5646 sb = malloc_domainset(sizeof(struct pmc_samplebuffer) + 5647 pmc_nsamples * sizeof(struct pmc_sample), M_PMC, 5648 DOMAINSET_PREF(domain), M_WAITOK | M_ZERO); 5649 5650 KASSERT(pmc_pcpu[cpu] != NULL, 5651 ("[pmc,%d] cpu=%d Null per-cpu data", __LINE__, cpu)); 5652 5653 sb->ps_callchains = malloc_domainset(pmc_callchaindepth * 5654 pmc_nsamples * sizeof(uintptr_t), M_PMC, 5655 DOMAINSET_PREF(domain), M_WAITOK | M_ZERO); 5656 5657 for (n = 0, ps = sb->ps_samples; n < pmc_nsamples; n++, ps++) 5658 ps->ps_pc = sb->ps_callchains + 5659 (n * pmc_callchaindepth); 5660 5661 pmc_pcpu[cpu]->pc_sb[PMC_HR] = sb; 5662 5663 sb = malloc_domainset(sizeof(struct pmc_samplebuffer) + 5664 pmc_nsamples * sizeof(struct pmc_sample), M_PMC, 5665 DOMAINSET_PREF(domain), M_WAITOK | M_ZERO); 5666 5667 sb->ps_callchains = malloc_domainset(pmc_callchaindepth * 5668 pmc_nsamples * sizeof(uintptr_t), M_PMC, 5669 DOMAINSET_PREF(domain), M_WAITOK | M_ZERO); 5670 for (n = 0, ps = sb->ps_samples; n < pmc_nsamples; n++, ps++) 5671 ps->ps_pc = sb->ps_callchains + 5672 (n * pmc_callchaindepth); 5673 5674 pmc_pcpu[cpu]->pc_sb[PMC_SR] = sb; 5675 5676 sb = malloc_domainset(sizeof(struct pmc_samplebuffer) + 5677 pmc_nsamples * sizeof(struct pmc_sample), M_PMC, 5678 DOMAINSET_PREF(domain), M_WAITOK | M_ZERO); 5679 sb->ps_callchains = malloc_domainset(pmc_callchaindepth * 5680 pmc_nsamples * sizeof(uintptr_t), M_PMC, 5681 DOMAINSET_PREF(domain), M_WAITOK | M_ZERO); 5682 for (n = 0, ps = sb->ps_samples; n < pmc_nsamples; n++, ps++) 5683 ps->ps_pc = sb->ps_callchains + n * pmc_callchaindepth; 5684 5685 pmc_pcpu[cpu]->pc_sb[PMC_UR] = sb; 5686 } 5687 5688 /* allocate space for the row disposition array */ 5689 pmc_pmcdisp = malloc(sizeof(enum pmc_mode) * md->pmd_npmc, 5690 M_PMC, M_WAITOK|M_ZERO); 5691 5692 /* mark all PMCs as available */ 5693 for (n = 0; n < (int) md->pmd_npmc; n++) 5694 PMC_MARK_ROW_FREE(n); 5695 5696 /* allocate thread hash tables */ 5697 pmc_ownerhash = hashinit(pmc_hashsize, M_PMC, 5698 &pmc_ownerhashmask); 5699 5700 pmc_processhash = hashinit(pmc_hashsize, M_PMC, 5701 &pmc_processhashmask); 5702 mtx_init(&pmc_processhash_mtx, "pmc-process-hash", "pmc-leaf", 5703 MTX_SPIN); 5704 5705 CK_LIST_INIT(&pmc_ss_owners); 5706 pmc_ss_count = 0; 5707 5708 /* allocate a pool of spin mutexes */ 5709 pmc_mtxpool = mtx_pool_create("pmc-leaf", pmc_mtxpool_size, 5710 MTX_SPIN); 5711 5712 PMCDBG4(MOD,INI,1, "pmc_ownerhash=%p, mask=0x%lx " 5713 "targethash=%p mask=0x%lx", pmc_ownerhash, pmc_ownerhashmask, 5714 pmc_processhash, pmc_processhashmask); 5715 5716 /* Initialize a spin mutex for the thread free list. */ 5717 mtx_init(&pmc_threadfreelist_mtx, "pmc-threadfreelist", "pmc-leaf", 5718 MTX_SPIN); 5719 5720 /* Initialize the task to prune the thread free list. */ 5721 TASK_INIT(&free_task, 0, pmc_thread_descriptor_pool_free_task, NULL); 5722 5723 /* register process {exit,fork,exec} handlers */ 5724 pmc_exit_tag = EVENTHANDLER_REGISTER(process_exit, 5725 pmc_process_exit, NULL, EVENTHANDLER_PRI_ANY); 5726 pmc_fork_tag = EVENTHANDLER_REGISTER(process_fork, 5727 pmc_process_fork, NULL, EVENTHANDLER_PRI_ANY); 5728 5729 /* register kld event handlers */ 5730 pmc_kld_load_tag = EVENTHANDLER_REGISTER(kld_load, pmc_kld_load, 5731 NULL, EVENTHANDLER_PRI_ANY); 5732 pmc_kld_unload_tag = EVENTHANDLER_REGISTER(kld_unload, pmc_kld_unload, 5733 NULL, EVENTHANDLER_PRI_ANY); 5734 5735 /* initialize logging */ 5736 pmclog_initialize(); 5737 5738 /* set hook functions */ 5739 pmc_intr = md->pmd_intr; 5740 wmb(); 5741 pmc_hook = pmc_hook_handler; 5742 5743 if (error == 0) { 5744 printf(PMC_MODULE_NAME ":"); 5745 for (n = 0; n < (int) md->pmd_nclass; n++) { 5746 pcd = &md->pmd_classdep[n]; 5747 printf(" %s/%d/%d/0x%b", 5748 pmc_name_of_pmcclass(pcd->pcd_class), 5749 pcd->pcd_num, 5750 pcd->pcd_width, 5751 pcd->pcd_caps, 5752 "\20" 5753 "\1INT\2USR\3SYS\4EDG\5THR" 5754 "\6REA\7WRI\10INV\11QUA\12PRC" 5755 "\13TAG\14CSC"); 5756 } 5757 printf("\n"); 5758 } 5759 5760 return (error); 5761 } 5762 5763 /* prepare to be unloaded */ 5764 static void 5765 pmc_cleanup(void) 5766 { 5767 int c, cpu; 5768 unsigned int maxcpu; 5769 struct pmc_ownerhash *ph; 5770 struct pmc_owner *po, *tmp; 5771 struct pmc_binding pb; 5772 #ifdef HWPMC_DEBUG 5773 struct pmc_processhash *prh; 5774 #endif 5775 5776 PMCDBG0(MOD,INI,0, "cleanup"); 5777 5778 /* switch off sampling */ 5779 CPU_FOREACH(cpu) 5780 DPCPU_ID_SET(cpu, pmc_sampled, 0); 5781 pmc_intr = NULL; 5782 5783 sx_xlock(&pmc_sx); 5784 if (pmc_hook == NULL) { /* being unloaded already */ 5785 sx_xunlock(&pmc_sx); 5786 return; 5787 } 5788 5789 pmc_hook = NULL; /* prevent new threads from entering module */ 5790 5791 /* deregister event handlers */ 5792 EVENTHANDLER_DEREGISTER(process_fork, pmc_fork_tag); 5793 EVENTHANDLER_DEREGISTER(process_exit, pmc_exit_tag); 5794 EVENTHANDLER_DEREGISTER(kld_load, pmc_kld_load_tag); 5795 EVENTHANDLER_DEREGISTER(kld_unload, pmc_kld_unload_tag); 5796 5797 /* send SIGBUS to all owner threads, free up allocations */ 5798 if (pmc_ownerhash) 5799 for (ph = pmc_ownerhash; 5800 ph <= &pmc_ownerhash[pmc_ownerhashmask]; 5801 ph++) { 5802 LIST_FOREACH_SAFE(po, ph, po_next, tmp) { 5803 pmc_remove_owner(po); 5804 5805 /* send SIGBUS to owner processes */ 5806 PMCDBG3(MOD,INI,2, "cleanup signal proc=%p " 5807 "(%d, %s)", po->po_owner, 5808 po->po_owner->p_pid, 5809 po->po_owner->p_comm); 5810 5811 PROC_LOCK(po->po_owner); 5812 kern_psignal(po->po_owner, SIGBUS); 5813 PROC_UNLOCK(po->po_owner); 5814 5815 pmc_destroy_owner_descriptor(po); 5816 } 5817 } 5818 5819 /* reclaim allocated data structures */ 5820 taskqueue_drain(taskqueue_fast, &free_task); 5821 mtx_destroy(&pmc_threadfreelist_mtx); 5822 pmc_thread_descriptor_pool_drain(); 5823 5824 if (pmc_mtxpool) 5825 mtx_pool_destroy(&pmc_mtxpool); 5826 5827 mtx_destroy(&pmc_processhash_mtx); 5828 if (pmc_processhash) { 5829 #ifdef HWPMC_DEBUG 5830 struct pmc_process *pp; 5831 5832 PMCDBG0(MOD,INI,3, "destroy process hash"); 5833 for (prh = pmc_processhash; 5834 prh <= &pmc_processhash[pmc_processhashmask]; 5835 prh++) 5836 LIST_FOREACH(pp, prh, pp_next) 5837 PMCDBG1(MOD,INI,3, "pid=%d", pp->pp_proc->p_pid); 5838 #endif 5839 5840 hashdestroy(pmc_processhash, M_PMC, pmc_processhashmask); 5841 pmc_processhash = NULL; 5842 } 5843 5844 if (pmc_ownerhash) { 5845 PMCDBG0(MOD,INI,3, "destroy owner hash"); 5846 hashdestroy(pmc_ownerhash, M_PMC, pmc_ownerhashmask); 5847 pmc_ownerhash = NULL; 5848 } 5849 5850 KASSERT(CK_LIST_EMPTY(&pmc_ss_owners), 5851 ("[pmc,%d] Global SS owner list not empty", __LINE__)); 5852 KASSERT(pmc_ss_count == 0, 5853 ("[pmc,%d] Global SS count not empty", __LINE__)); 5854 5855 /* do processor and pmc-class dependent cleanup */ 5856 maxcpu = pmc_cpu_max(); 5857 5858 PMCDBG0(MOD,INI,3, "md cleanup"); 5859 if (md) { 5860 pmc_save_cpu_binding(&pb); 5861 for (cpu = 0; cpu < maxcpu; cpu++) { 5862 PMCDBG2(MOD,INI,1,"pmc-cleanup cpu=%d pcs=%p", 5863 cpu, pmc_pcpu[cpu]); 5864 if (!pmc_cpu_is_active(cpu) || pmc_pcpu[cpu] == NULL) 5865 continue; 5866 pmc_select_cpu(cpu); 5867 for (c = 0; c < md->pmd_nclass; c++) 5868 md->pmd_classdep[c].pcd_pcpu_fini(md, cpu); 5869 if (md->pmd_pcpu_fini) 5870 md->pmd_pcpu_fini(md, cpu); 5871 } 5872 5873 if (md->pmd_cputype == PMC_CPU_GENERIC) 5874 pmc_generic_cpu_finalize(md); 5875 else 5876 pmc_md_finalize(md); 5877 5878 pmc_mdep_free(md); 5879 md = NULL; 5880 pmc_restore_cpu_binding(&pb); 5881 } 5882 5883 /* Free per-cpu descriptors. */ 5884 for (cpu = 0; cpu < maxcpu; cpu++) { 5885 if (!pmc_cpu_is_active(cpu)) 5886 continue; 5887 KASSERT(pmc_pcpu[cpu]->pc_sb[PMC_HR] != NULL, 5888 ("[pmc,%d] Null hw cpu sample buffer cpu=%d", __LINE__, 5889 cpu)); 5890 KASSERT(pmc_pcpu[cpu]->pc_sb[PMC_SR] != NULL, 5891 ("[pmc,%d] Null sw cpu sample buffer cpu=%d", __LINE__, 5892 cpu)); 5893 KASSERT(pmc_pcpu[cpu]->pc_sb[PMC_UR] != NULL, 5894 ("[pmc,%d] Null userret cpu sample buffer cpu=%d", __LINE__, 5895 cpu)); 5896 free(pmc_pcpu[cpu]->pc_sb[PMC_HR]->ps_callchains, M_PMC); 5897 free(pmc_pcpu[cpu]->pc_sb[PMC_HR], M_PMC); 5898 free(pmc_pcpu[cpu]->pc_sb[PMC_SR]->ps_callchains, M_PMC); 5899 free(pmc_pcpu[cpu]->pc_sb[PMC_SR], M_PMC); 5900 free(pmc_pcpu[cpu]->pc_sb[PMC_UR]->ps_callchains, M_PMC); 5901 free(pmc_pcpu[cpu]->pc_sb[PMC_UR], M_PMC); 5902 free(pmc_pcpu[cpu], M_PMC); 5903 } 5904 5905 free(pmc_pcpu, M_PMC); 5906 pmc_pcpu = NULL; 5907 5908 free(pmc_pcpu_saved, M_PMC); 5909 pmc_pcpu_saved = NULL; 5910 5911 if (pmc_pmcdisp) { 5912 free(pmc_pmcdisp, M_PMC); 5913 pmc_pmcdisp = NULL; 5914 } 5915 5916 if (pmc_rowindex_to_classdep) { 5917 free(pmc_rowindex_to_classdep, M_PMC); 5918 pmc_rowindex_to_classdep = NULL; 5919 } 5920 5921 pmclog_shutdown(); 5922 counter_u64_free(pmc_stats.pm_intr_ignored); 5923 counter_u64_free(pmc_stats.pm_intr_processed); 5924 counter_u64_free(pmc_stats.pm_intr_bufferfull); 5925 counter_u64_free(pmc_stats.pm_syscalls); 5926 counter_u64_free(pmc_stats.pm_syscall_errors); 5927 counter_u64_free(pmc_stats.pm_buffer_requests); 5928 counter_u64_free(pmc_stats.pm_buffer_requests_failed); 5929 counter_u64_free(pmc_stats.pm_log_sweeps); 5930 counter_u64_free(pmc_stats.pm_merges); 5931 counter_u64_free(pmc_stats.pm_overwrites); 5932 sx_xunlock(&pmc_sx); /* we are done */ 5933 } 5934 5935 /* 5936 * The function called at load/unload. 5937 */ 5938 5939 static int 5940 load (struct module *module __unused, int cmd, void *arg __unused) 5941 { 5942 int error; 5943 5944 error = 0; 5945 5946 switch (cmd) { 5947 case MOD_LOAD : 5948 /* initialize the subsystem */ 5949 error = pmc_initialize(); 5950 if (error != 0) 5951 break; 5952 PMCDBG2(MOD,INI,1, "syscall=%d maxcpu=%d", 5953 pmc_syscall_num, pmc_cpu_max()); 5954 break; 5955 5956 5957 case MOD_UNLOAD : 5958 case MOD_SHUTDOWN: 5959 pmc_cleanup(); 5960 PMCDBG0(MOD,INI,1, "unloaded"); 5961 break; 5962 5963 default : 5964 error = EINVAL; /* XXX should panic(9) */ 5965 break; 5966 } 5967 5968 return error; 5969 } 5970