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/domainset.h> 40 #include <sys/eventhandler.h> 41 #include <sys/gtaskqueue.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/systm.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 grouptask free_gtask; 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, 0, "HWPMC stats"); 279 280 281 /* Stats. */ 282 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, intr_ignored, CTLFLAG_RW, 283 &pmc_stats.pm_intr_ignored, "# of interrupts ignored"); 284 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, intr_processed, CTLFLAG_RW, 285 &pmc_stats.pm_intr_processed, "# of interrupts processed"); 286 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, intr_bufferfull, CTLFLAG_RW, 287 &pmc_stats.pm_intr_bufferfull, "# of interrupts where buffer was full"); 288 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, syscalls, CTLFLAG_RW, 289 &pmc_stats.pm_syscalls, "# of syscalls"); 290 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, syscall_errors, CTLFLAG_RW, 291 &pmc_stats.pm_syscall_errors, "# of syscall_errors"); 292 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, buffer_requests, CTLFLAG_RW, 293 &pmc_stats.pm_buffer_requests, "# of buffer requests"); 294 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, buffer_requests_failed, CTLFLAG_RW, 295 &pmc_stats.pm_buffer_requests_failed, "# of buffer requests which failed"); 296 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, log_sweeps, CTLFLAG_RW, 297 &pmc_stats.pm_log_sweeps, "# of ?"); 298 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, merges, CTLFLAG_RW, 299 &pmc_stats.pm_merges, "# of times kernel stack was found for user trace"); 300 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, overwrites, CTLFLAG_RW, 301 &pmc_stats.pm_overwrites, "# of times a sample was overwritten before being logged"); 302 303 static int pmc_callchaindepth = PMC_CALLCHAIN_DEPTH; 304 SYSCTL_INT(_kern_hwpmc, OID_AUTO, callchaindepth, CTLFLAG_RDTUN, 305 &pmc_callchaindepth, 0, "depth of call chain records"); 306 307 char pmc_cpuid[64]; 308 SYSCTL_STRING(_kern_hwpmc, OID_AUTO, cpuid, CTLFLAG_RD, 309 pmc_cpuid, 0, "cpu version string"); 310 #ifdef HWPMC_DEBUG 311 struct pmc_debugflags pmc_debugflags = PMC_DEBUG_DEFAULT_FLAGS; 312 char pmc_debugstr[PMC_DEBUG_STRSIZE]; 313 TUNABLE_STR(PMC_SYSCTL_NAME_PREFIX "debugflags", pmc_debugstr, 314 sizeof(pmc_debugstr)); 315 SYSCTL_PROC(_kern_hwpmc, OID_AUTO, debugflags, 316 CTLTYPE_STRING | CTLFLAG_RWTUN | CTLFLAG_NOFETCH, 317 0, 0, pmc_debugflags_sysctl_handler, "A", "debug flags"); 318 #endif 319 320 321 /* 322 * kern.hwpmc.hashrows -- determines the number of rows in the 323 * of the hash table used to look up threads 324 */ 325 326 static int pmc_hashsize = PMC_HASH_SIZE; 327 SYSCTL_INT(_kern_hwpmc, OID_AUTO, hashsize, CTLFLAG_RDTUN, 328 &pmc_hashsize, 0, "rows in hash tables"); 329 330 /* 331 * kern.hwpmc.nsamples --- number of PC samples/callchain stacks per CPU 332 */ 333 334 static int pmc_nsamples = PMC_NSAMPLES; 335 SYSCTL_INT(_kern_hwpmc, OID_AUTO, nsamples, CTLFLAG_RDTUN, 336 &pmc_nsamples, 0, "number of PC samples per CPU"); 337 338 static uint64_t pmc_sample_mask = PMC_NSAMPLES-1; 339 340 /* 341 * kern.hwpmc.mtxpoolsize -- number of mutexes in the mutex pool. 342 */ 343 344 static int pmc_mtxpool_size = PMC_MTXPOOL_SIZE; 345 SYSCTL_INT(_kern_hwpmc, OID_AUTO, mtxpoolsize, CTLFLAG_RDTUN, 346 &pmc_mtxpool_size, 0, "size of spin mutex pool"); 347 348 349 /* 350 * kern.hwpmc.threadfreelist_entries -- number of free entries 351 */ 352 353 SYSCTL_INT(_kern_hwpmc, OID_AUTO, threadfreelist_entries, CTLFLAG_RD, 354 &pmc_threadfreelist_entries, 0, "number of avalable thread entries"); 355 356 357 /* 358 * kern.hwpmc.threadfreelist_max -- maximum number of free entries 359 */ 360 361 static int pmc_threadfreelist_max = PMC_THREADLIST_MAX; 362 SYSCTL_INT(_kern_hwpmc, OID_AUTO, threadfreelist_max, CTLFLAG_RW, 363 &pmc_threadfreelist_max, 0, 364 "maximum number of available thread entries before freeing some"); 365 366 367 /* 368 * security.bsd.unprivileged_syspmcs -- allow non-root processes to 369 * allocate system-wide PMCs. 370 * 371 * Allowing unprivileged processes to allocate system PMCs is convenient 372 * if system-wide measurements need to be taken concurrently with other 373 * per-process measurements. This feature is turned off by default. 374 */ 375 376 static int pmc_unprivileged_syspmcs = 0; 377 SYSCTL_INT(_security_bsd, OID_AUTO, unprivileged_syspmcs, CTLFLAG_RWTUN, 378 &pmc_unprivileged_syspmcs, 0, 379 "allow unprivileged process to allocate system PMCs"); 380 381 /* 382 * Hash function. Discard the lower 2 bits of the pointer since 383 * these are always zero for our uses. The hash multiplier is 384 * round((2^LONG_BIT) * ((sqrt(5)-1)/2)). 385 */ 386 387 #if LONG_BIT == 64 388 #define _PMC_HM 11400714819323198486u 389 #elif LONG_BIT == 32 390 #define _PMC_HM 2654435769u 391 #else 392 #error Must know the size of 'long' to compile 393 #endif 394 395 #define PMC_HASH_PTR(P,M) ((((unsigned long) (P) >> 2) * _PMC_HM) & (M)) 396 397 /* 398 * Syscall structures 399 */ 400 401 /* The `sysent' for the new syscall */ 402 static struct sysent pmc_sysent = { 403 .sy_narg = 2, 404 .sy_call = pmc_syscall_handler, 405 }; 406 407 static struct syscall_module_data pmc_syscall_mod = { 408 .chainevh = load, 409 .chainarg = NULL, 410 .offset = &pmc_syscall_num, 411 .new_sysent = &pmc_sysent, 412 .old_sysent = { .sy_narg = 0, .sy_call = NULL }, 413 .flags = SY_THR_STATIC_KLD, 414 }; 415 416 static moduledata_t pmc_mod = { 417 .name = PMC_MODULE_NAME, 418 .evhand = syscall_module_handler, 419 .priv = &pmc_syscall_mod, 420 }; 421 422 #ifdef EARLY_AP_STARTUP 423 DECLARE_MODULE(pmc, pmc_mod, SI_SUB_SYSCALLS, SI_ORDER_ANY); 424 #else 425 DECLARE_MODULE(pmc, pmc_mod, SI_SUB_SMP, SI_ORDER_ANY); 426 #endif 427 MODULE_VERSION(pmc, PMC_VERSION); 428 429 #ifdef HWPMC_DEBUG 430 enum pmc_dbgparse_state { 431 PMCDS_WS, /* in whitespace */ 432 PMCDS_MAJOR, /* seen a major keyword */ 433 PMCDS_MINOR 434 }; 435 436 static int 437 pmc_debugflags_parse(char *newstr, char *fence) 438 { 439 char c, *p, *q; 440 struct pmc_debugflags *tmpflags; 441 int error, found, *newbits, tmp; 442 size_t kwlen; 443 444 tmpflags = malloc(sizeof(*tmpflags), M_PMC, M_WAITOK|M_ZERO); 445 446 p = newstr; 447 error = 0; 448 449 for (; p < fence && (c = *p); p++) { 450 451 /* skip white space */ 452 if (c == ' ' || c == '\t') 453 continue; 454 455 /* look for a keyword followed by "=" */ 456 for (q = p; p < fence && (c = *p) && c != '='; p++) 457 ; 458 if (c != '=') { 459 error = EINVAL; 460 goto done; 461 } 462 463 kwlen = p - q; 464 newbits = NULL; 465 466 /* lookup flag group name */ 467 #define DBG_SET_FLAG_MAJ(S,F) \ 468 if (kwlen == sizeof(S)-1 && strncmp(q, S, kwlen) == 0) \ 469 newbits = &tmpflags->pdb_ ## F; 470 471 DBG_SET_FLAG_MAJ("cpu", CPU); 472 DBG_SET_FLAG_MAJ("csw", CSW); 473 DBG_SET_FLAG_MAJ("logging", LOG); 474 DBG_SET_FLAG_MAJ("module", MOD); 475 DBG_SET_FLAG_MAJ("md", MDP); 476 DBG_SET_FLAG_MAJ("owner", OWN); 477 DBG_SET_FLAG_MAJ("pmc", PMC); 478 DBG_SET_FLAG_MAJ("process", PRC); 479 DBG_SET_FLAG_MAJ("sampling", SAM); 480 481 if (newbits == NULL) { 482 error = EINVAL; 483 goto done; 484 } 485 486 p++; /* skip the '=' */ 487 488 /* Now parse the individual flags */ 489 tmp = 0; 490 newflag: 491 for (q = p; p < fence && (c = *p); p++) 492 if (c == ' ' || c == '\t' || c == ',') 493 break; 494 495 /* p == fence or c == ws or c == "," or c == 0 */ 496 497 if ((kwlen = p - q) == 0) { 498 *newbits = tmp; 499 continue; 500 } 501 502 found = 0; 503 #define DBG_SET_FLAG_MIN(S,F) \ 504 if (kwlen == sizeof(S)-1 && strncmp(q, S, kwlen) == 0) \ 505 tmp |= found = (1 << PMC_DEBUG_MIN_ ## F) 506 507 /* a '*' denotes all possible flags in the group */ 508 if (kwlen == 1 && *q == '*') 509 tmp = found = ~0; 510 /* look for individual flag names */ 511 DBG_SET_FLAG_MIN("allocaterow", ALR); 512 DBG_SET_FLAG_MIN("allocate", ALL); 513 DBG_SET_FLAG_MIN("attach", ATT); 514 DBG_SET_FLAG_MIN("bind", BND); 515 DBG_SET_FLAG_MIN("config", CFG); 516 DBG_SET_FLAG_MIN("exec", EXC); 517 DBG_SET_FLAG_MIN("exit", EXT); 518 DBG_SET_FLAG_MIN("find", FND); 519 DBG_SET_FLAG_MIN("flush", FLS); 520 DBG_SET_FLAG_MIN("fork", FRK); 521 DBG_SET_FLAG_MIN("getbuf", GTB); 522 DBG_SET_FLAG_MIN("hook", PMH); 523 DBG_SET_FLAG_MIN("init", INI); 524 DBG_SET_FLAG_MIN("intr", INT); 525 DBG_SET_FLAG_MIN("linktarget", TLK); 526 DBG_SET_FLAG_MIN("mayberemove", OMR); 527 DBG_SET_FLAG_MIN("ops", OPS); 528 DBG_SET_FLAG_MIN("read", REA); 529 DBG_SET_FLAG_MIN("register", REG); 530 DBG_SET_FLAG_MIN("release", REL); 531 DBG_SET_FLAG_MIN("remove", ORM); 532 DBG_SET_FLAG_MIN("sample", SAM); 533 DBG_SET_FLAG_MIN("scheduleio", SIO); 534 DBG_SET_FLAG_MIN("select", SEL); 535 DBG_SET_FLAG_MIN("signal", SIG); 536 DBG_SET_FLAG_MIN("swi", SWI); 537 DBG_SET_FLAG_MIN("swo", SWO); 538 DBG_SET_FLAG_MIN("start", STA); 539 DBG_SET_FLAG_MIN("stop", STO); 540 DBG_SET_FLAG_MIN("syscall", PMS); 541 DBG_SET_FLAG_MIN("unlinktarget", TUL); 542 DBG_SET_FLAG_MIN("write", WRI); 543 if (found == 0) { 544 /* unrecognized flag name */ 545 error = EINVAL; 546 goto done; 547 } 548 549 if (c == 0 || c == ' ' || c == '\t') { /* end of flag group */ 550 *newbits = tmp; 551 continue; 552 } 553 554 p++; 555 goto newflag; 556 } 557 558 /* save the new flag set */ 559 bcopy(tmpflags, &pmc_debugflags, sizeof(pmc_debugflags)); 560 561 done: 562 free(tmpflags, M_PMC); 563 return error; 564 } 565 566 static int 567 pmc_debugflags_sysctl_handler(SYSCTL_HANDLER_ARGS) 568 { 569 char *fence, *newstr; 570 int error; 571 unsigned int n; 572 573 (void) arg1; (void) arg2; /* unused parameters */ 574 575 n = sizeof(pmc_debugstr); 576 newstr = malloc(n, M_PMC, M_WAITOK|M_ZERO); 577 (void) strlcpy(newstr, pmc_debugstr, n); 578 579 error = sysctl_handle_string(oidp, newstr, n, req); 580 581 /* if there is a new string, parse and copy it */ 582 if (error == 0 && req->newptr != NULL) { 583 fence = newstr + (n < req->newlen ? n : req->newlen + 1); 584 if ((error = pmc_debugflags_parse(newstr, fence)) == 0) 585 (void) strlcpy(pmc_debugstr, newstr, 586 sizeof(pmc_debugstr)); 587 } 588 589 free(newstr, M_PMC); 590 591 return error; 592 } 593 #endif 594 595 /* 596 * Map a row index to a classdep structure and return the adjusted row 597 * index for the PMC class index. 598 */ 599 static struct pmc_classdep * 600 pmc_ri_to_classdep(struct pmc_mdep *md, int ri, int *adjri) 601 { 602 struct pmc_classdep *pcd; 603 604 (void) md; 605 606 KASSERT(ri >= 0 && ri < md->pmd_npmc, 607 ("[pmc,%d] illegal row-index %d", __LINE__, ri)); 608 609 pcd = pmc_rowindex_to_classdep[ri]; 610 611 KASSERT(pcd != NULL, 612 ("[pmc,%d] ri %d null pcd", __LINE__, ri)); 613 614 *adjri = ri - pcd->pcd_ri; 615 616 KASSERT(*adjri >= 0 && *adjri < pcd->pcd_num, 617 ("[pmc,%d] adjusted row-index %d", __LINE__, *adjri)); 618 619 return (pcd); 620 } 621 622 /* 623 * Concurrency Control 624 * 625 * The driver manages the following data structures: 626 * 627 * - target process descriptors, one per target process 628 * - owner process descriptors (and attached lists), one per owner process 629 * - lookup hash tables for owner and target processes 630 * - PMC descriptors (and attached lists) 631 * - per-cpu hardware state 632 * - the 'hook' variable through which the kernel calls into 633 * this module 634 * - the machine hardware state (managed by the MD layer) 635 * 636 * These data structures are accessed from: 637 * 638 * - thread context-switch code 639 * - interrupt handlers (possibly on multiple cpus) 640 * - kernel threads on multiple cpus running on behalf of user 641 * processes doing system calls 642 * - this driver's private kernel threads 643 * 644 * = Locks and Locking strategy = 645 * 646 * The driver uses four locking strategies for its operation: 647 * 648 * - The global SX lock "pmc_sx" is used to protect internal 649 * data structures. 650 * 651 * Calls into the module by syscall() start with this lock being 652 * held in exclusive mode. Depending on the requested operation, 653 * the lock may be downgraded to 'shared' mode to allow more 654 * concurrent readers into the module. Calls into the module from 655 * other parts of the kernel acquire the lock in shared mode. 656 * 657 * This SX lock is held in exclusive mode for any operations that 658 * modify the linkages between the driver's internal data structures. 659 * 660 * The 'pmc_hook' function pointer is also protected by this lock. 661 * It is only examined with the sx lock held in exclusive mode. The 662 * kernel module is allowed to be unloaded only with the sx lock held 663 * in exclusive mode. In normal syscall handling, after acquiring the 664 * pmc_sx lock we first check that 'pmc_hook' is non-null before 665 * proceeding. This prevents races between the thread unloading the module 666 * and other threads seeking to use the module. 667 * 668 * - Lookups of target process structures and owner process structures 669 * cannot use the global "pmc_sx" SX lock because these lookups need 670 * to happen during context switches and in other critical sections 671 * where sleeping is not allowed. We protect these lookup tables 672 * with their own private spin-mutexes, "pmc_processhash_mtx" and 673 * "pmc_ownerhash_mtx". 674 * 675 * - Interrupt handlers work in a lock free manner. At interrupt 676 * time, handlers look at the PMC pointer (phw->phw_pmc) configured 677 * when the PMC was started. If this pointer is NULL, the interrupt 678 * is ignored after updating driver statistics. We ensure that this 679 * pointer is set (using an atomic operation if necessary) before the 680 * PMC hardware is started. Conversely, this pointer is unset atomically 681 * only after the PMC hardware is stopped. 682 * 683 * We ensure that everything needed for the operation of an 684 * interrupt handler is available without it needing to acquire any 685 * locks. We also ensure that a PMC's software state is destroyed only 686 * after the PMC is taken off hardware (on all CPUs). 687 * 688 * - Context-switch handling with process-private PMCs needs more 689 * care. 690 * 691 * A given process may be the target of multiple PMCs. For example, 692 * PMCATTACH and PMCDETACH may be requested by a process on one CPU 693 * while the target process is running on another. A PMC could also 694 * be getting released because its owner is exiting. We tackle 695 * these situations in the following manner: 696 * 697 * - each target process structure 'pmc_process' has an array 698 * of 'struct pmc *' pointers, one for each hardware PMC. 699 * 700 * - At context switch IN time, each "target" PMC in RUNNING state 701 * gets started on hardware and a pointer to each PMC is copied into 702 * the per-cpu phw array. The 'runcount' for the PMC is 703 * incremented. 704 * 705 * - At context switch OUT time, all process-virtual PMCs are stopped 706 * on hardware. The saved value is added to the PMCs value field 707 * only if the PMC is in a non-deleted state (the PMCs state could 708 * have changed during the current time slice). 709 * 710 * Note that since in-between a switch IN on a processor and a switch 711 * OUT, the PMC could have been released on another CPU. Therefore 712 * context switch OUT always looks at the hardware state to turn 713 * OFF PMCs and will update a PMC's saved value only if reachable 714 * from the target process record. 715 * 716 * - OP PMCRELEASE could be called on a PMC at any time (the PMC could 717 * be attached to many processes at the time of the call and could 718 * be active on multiple CPUs). 719 * 720 * We prevent further scheduling of the PMC by marking it as in 721 * state 'DELETED'. If the runcount of the PMC is non-zero then 722 * this PMC is currently running on a CPU somewhere. The thread 723 * doing the PMCRELEASE operation waits by repeatedly doing a 724 * pause() till the runcount comes to zero. 725 * 726 * The contents of a PMC descriptor (struct pmc) are protected using 727 * a spin-mutex. In order to save space, we use a mutex pool. 728 * 729 * In terms of lock types used by witness(4), we use: 730 * - Type "pmc-sx", used by the global SX lock. 731 * - Type "pmc-sleep", for sleep mutexes used by logger threads. 732 * - Type "pmc-per-proc", for protecting PMC owner descriptors. 733 * - Type "pmc-leaf", used for all other spin mutexes. 734 */ 735 736 /* 737 * save the cpu binding of the current kthread 738 */ 739 740 static void 741 pmc_save_cpu_binding(struct pmc_binding *pb) 742 { 743 PMCDBG0(CPU,BND,2, "save-cpu"); 744 thread_lock(curthread); 745 pb->pb_bound = sched_is_bound(curthread); 746 pb->pb_cpu = curthread->td_oncpu; 747 thread_unlock(curthread); 748 PMCDBG1(CPU,BND,2, "save-cpu cpu=%d", pb->pb_cpu); 749 } 750 751 /* 752 * restore the cpu binding of the current thread 753 */ 754 755 static void 756 pmc_restore_cpu_binding(struct pmc_binding *pb) 757 { 758 PMCDBG2(CPU,BND,2, "restore-cpu curcpu=%d restore=%d", 759 curthread->td_oncpu, pb->pb_cpu); 760 thread_lock(curthread); 761 if (pb->pb_bound) 762 sched_bind(curthread, pb->pb_cpu); 763 else 764 sched_unbind(curthread); 765 thread_unlock(curthread); 766 PMCDBG0(CPU,BND,2, "restore-cpu done"); 767 } 768 769 /* 770 * move execution over the specified cpu and bind it there. 771 */ 772 773 static void 774 pmc_select_cpu(int cpu) 775 { 776 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 777 ("[pmc,%d] bad cpu number %d", __LINE__, cpu)); 778 779 /* Never move to an inactive CPU. */ 780 KASSERT(pmc_cpu_is_active(cpu), ("[pmc,%d] selecting inactive " 781 "CPU %d", __LINE__, cpu)); 782 783 PMCDBG1(CPU,SEL,2, "select-cpu cpu=%d", cpu); 784 thread_lock(curthread); 785 sched_bind(curthread, cpu); 786 thread_unlock(curthread); 787 788 KASSERT(curthread->td_oncpu == cpu, 789 ("[pmc,%d] CPU not bound [cpu=%d, curr=%d]", __LINE__, 790 cpu, curthread->td_oncpu)); 791 792 PMCDBG1(CPU,SEL,2, "select-cpu cpu=%d ok", cpu); 793 } 794 795 /* 796 * Force a context switch. 797 * 798 * We do this by pause'ing for 1 tick -- invoking mi_switch() is not 799 * guaranteed to force a context switch. 800 */ 801 802 static void 803 pmc_force_context_switch(void) 804 { 805 806 pause("pmcctx", 1); 807 } 808 809 uint64_t 810 pmc_rdtsc(void) 811 { 812 #if defined(__i386__) || defined(__amd64__) 813 if (__predict_true(amd_feature & AMDID_RDTSCP)) 814 return rdtscp(); 815 else 816 return rdtsc(); 817 #else 818 return get_cyclecount(); 819 #endif 820 } 821 822 /* 823 * Get the file name for an executable. This is a simple wrapper 824 * around vn_fullpath(9). 825 */ 826 827 static void 828 pmc_getfilename(struct vnode *v, char **fullpath, char **freepath) 829 { 830 831 *fullpath = "unknown"; 832 *freepath = NULL; 833 vn_fullpath(curthread, v, fullpath, freepath); 834 } 835 836 /* 837 * remove an process owning PMCs 838 */ 839 840 void 841 pmc_remove_owner(struct pmc_owner *po) 842 { 843 struct pmc *pm, *tmp; 844 845 sx_assert(&pmc_sx, SX_XLOCKED); 846 847 PMCDBG1(OWN,ORM,1, "remove-owner po=%p", po); 848 849 /* Remove descriptor from the owner hash table */ 850 LIST_REMOVE(po, po_next); 851 852 /* release all owned PMC descriptors */ 853 LIST_FOREACH_SAFE(pm, &po->po_pmcs, pm_next, tmp) { 854 PMCDBG1(OWN,ORM,2, "pmc=%p", pm); 855 KASSERT(pm->pm_owner == po, 856 ("[pmc,%d] owner %p != po %p", __LINE__, pm->pm_owner, po)); 857 858 pmc_release_pmc_descriptor(pm); /* will unlink from the list */ 859 pmc_destroy_pmc_descriptor(pm); 860 } 861 862 KASSERT(po->po_sscount == 0, 863 ("[pmc,%d] SS count not zero", __LINE__)); 864 KASSERT(LIST_EMPTY(&po->po_pmcs), 865 ("[pmc,%d] PMC list not empty", __LINE__)); 866 867 /* de-configure the log file if present */ 868 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 869 pmclog_deconfigure_log(po); 870 } 871 872 /* 873 * remove an owner process record if all conditions are met. 874 */ 875 876 static void 877 pmc_maybe_remove_owner(struct pmc_owner *po) 878 { 879 880 PMCDBG1(OWN,OMR,1, "maybe-remove-owner po=%p", po); 881 882 /* 883 * Remove owner record if 884 * - this process does not own any PMCs 885 * - this process has not allocated a system-wide sampling buffer 886 */ 887 888 if (LIST_EMPTY(&po->po_pmcs) && 889 ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0)) { 890 pmc_remove_owner(po); 891 pmc_destroy_owner_descriptor(po); 892 } 893 } 894 895 /* 896 * Add an association between a target process and a PMC. 897 */ 898 899 static void 900 pmc_link_target_process(struct pmc *pm, struct pmc_process *pp) 901 { 902 int ri; 903 struct pmc_target *pt; 904 #ifdef INVARIANTS 905 struct pmc_thread *pt_td; 906 #endif 907 908 sx_assert(&pmc_sx, SX_XLOCKED); 909 910 KASSERT(pm != NULL && pp != NULL, 911 ("[pmc,%d] Null pm %p or pp %p", __LINE__, pm, pp)); 912 KASSERT(PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)), 913 ("[pmc,%d] Attaching a non-process-virtual pmc=%p to pid=%d", 914 __LINE__, pm, pp->pp_proc->p_pid)); 915 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= ((int) md->pmd_npmc - 1), 916 ("[pmc,%d] Illegal reference count %d for process record %p", 917 __LINE__, pp->pp_refcnt, (void *) pp)); 918 919 ri = PMC_TO_ROWINDEX(pm); 920 921 PMCDBG3(PRC,TLK,1, "link-target pmc=%p ri=%d pmc-process=%p", 922 pm, ri, pp); 923 924 #ifdef HWPMC_DEBUG 925 LIST_FOREACH(pt, &pm->pm_targets, pt_next) 926 if (pt->pt_process == pp) 927 KASSERT(0, ("[pmc,%d] pp %p already in pmc %p targets", 928 __LINE__, pp, pm)); 929 #endif 930 931 pt = malloc(sizeof(struct pmc_target), M_PMC, M_WAITOK|M_ZERO); 932 pt->pt_process = pp; 933 934 LIST_INSERT_HEAD(&pm->pm_targets, pt, pt_next); 935 936 atomic_store_rel_ptr((uintptr_t *)&pp->pp_pmcs[ri].pp_pmc, 937 (uintptr_t)pm); 938 939 if (pm->pm_owner->po_owner == pp->pp_proc) 940 pm->pm_flags |= PMC_F_ATTACHED_TO_OWNER; 941 942 /* 943 * Initialize the per-process values at this row index. 944 */ 945 pp->pp_pmcs[ri].pp_pmcval = PMC_TO_MODE(pm) == PMC_MODE_TS ? 946 pm->pm_sc.pm_reloadcount : 0; 947 948 pp->pp_refcnt++; 949 950 #ifdef INVARIANTS 951 /* Confirm that the per-thread values at this row index are cleared. */ 952 if (PMC_TO_MODE(pm) == PMC_MODE_TS) { 953 mtx_lock_spin(pp->pp_tdslock); 954 LIST_FOREACH(pt_td, &pp->pp_tds, pt_next) { 955 KASSERT(pt_td->pt_pmcs[ri].pt_pmcval == (pmc_value_t) 0, 956 ("[pmc,%d] pt_pmcval not cleared for pid=%d at " 957 "ri=%d", __LINE__, pp->pp_proc->p_pid, ri)); 958 } 959 mtx_unlock_spin(pp->pp_tdslock); 960 } 961 #endif 962 } 963 964 /* 965 * Removes the association between a target process and a PMC. 966 */ 967 968 static void 969 pmc_unlink_target_process(struct pmc *pm, struct pmc_process *pp) 970 { 971 int ri; 972 struct proc *p; 973 struct pmc_target *ptgt; 974 struct pmc_thread *pt; 975 976 sx_assert(&pmc_sx, SX_XLOCKED); 977 978 KASSERT(pm != NULL && pp != NULL, 979 ("[pmc,%d] Null pm %p or pp %p", __LINE__, pm, pp)); 980 981 KASSERT(pp->pp_refcnt >= 1 && pp->pp_refcnt <= (int) md->pmd_npmc, 982 ("[pmc,%d] Illegal ref count %d on process record %p", 983 __LINE__, pp->pp_refcnt, (void *) pp)); 984 985 ri = PMC_TO_ROWINDEX(pm); 986 987 PMCDBG3(PRC,TUL,1, "unlink-target pmc=%p ri=%d pmc-process=%p", 988 pm, ri, pp); 989 990 KASSERT(pp->pp_pmcs[ri].pp_pmc == pm, 991 ("[pmc,%d] PMC ri %d mismatch pmc %p pp->[ri] %p", __LINE__, 992 ri, pm, pp->pp_pmcs[ri].pp_pmc)); 993 994 pp->pp_pmcs[ri].pp_pmc = NULL; 995 pp->pp_pmcs[ri].pp_pmcval = (pmc_value_t) 0; 996 997 /* Clear the per-thread values at this row index. */ 998 if (PMC_TO_MODE(pm) == PMC_MODE_TS) { 999 mtx_lock_spin(pp->pp_tdslock); 1000 LIST_FOREACH(pt, &pp->pp_tds, pt_next) 1001 pt->pt_pmcs[ri].pt_pmcval = (pmc_value_t) 0; 1002 mtx_unlock_spin(pp->pp_tdslock); 1003 } 1004 1005 /* Remove owner-specific flags */ 1006 if (pm->pm_owner->po_owner == pp->pp_proc) { 1007 pp->pp_flags &= ~PMC_PP_ENABLE_MSR_ACCESS; 1008 pm->pm_flags &= ~PMC_F_ATTACHED_TO_OWNER; 1009 } 1010 1011 pp->pp_refcnt--; 1012 1013 /* Remove the target process from the PMC structure */ 1014 LIST_FOREACH(ptgt, &pm->pm_targets, pt_next) 1015 if (ptgt->pt_process == pp) 1016 break; 1017 1018 KASSERT(ptgt != NULL, ("[pmc,%d] process %p (pp: %p) not found " 1019 "in pmc %p", __LINE__, pp->pp_proc, pp, pm)); 1020 1021 LIST_REMOVE(ptgt, pt_next); 1022 free(ptgt, M_PMC); 1023 1024 /* if the PMC now lacks targets, send the owner a SIGIO */ 1025 if (LIST_EMPTY(&pm->pm_targets)) { 1026 p = pm->pm_owner->po_owner; 1027 PROC_LOCK(p); 1028 kern_psignal(p, SIGIO); 1029 PROC_UNLOCK(p); 1030 1031 PMCDBG2(PRC,SIG,2, "signalling proc=%p signal=%d", p, 1032 SIGIO); 1033 } 1034 } 1035 1036 /* 1037 * Check if PMC 'pm' may be attached to target process 't'. 1038 */ 1039 1040 static int 1041 pmc_can_attach(struct pmc *pm, struct proc *t) 1042 { 1043 struct proc *o; /* pmc owner */ 1044 struct ucred *oc, *tc; /* owner, target credentials */ 1045 int decline_attach, i; 1046 1047 /* 1048 * A PMC's owner can always attach that PMC to itself. 1049 */ 1050 1051 if ((o = pm->pm_owner->po_owner) == t) 1052 return 0; 1053 1054 PROC_LOCK(o); 1055 oc = o->p_ucred; 1056 crhold(oc); 1057 PROC_UNLOCK(o); 1058 1059 PROC_LOCK(t); 1060 tc = t->p_ucred; 1061 crhold(tc); 1062 PROC_UNLOCK(t); 1063 1064 /* 1065 * The effective uid of the PMC owner should match at least one 1066 * of the {effective,real,saved} uids of the target process. 1067 */ 1068 1069 decline_attach = oc->cr_uid != tc->cr_uid && 1070 oc->cr_uid != tc->cr_svuid && 1071 oc->cr_uid != tc->cr_ruid; 1072 1073 /* 1074 * Every one of the target's group ids, must be in the owner's 1075 * group list. 1076 */ 1077 for (i = 0; !decline_attach && i < tc->cr_ngroups; i++) 1078 decline_attach = !groupmember(tc->cr_groups[i], oc); 1079 1080 /* check the read and saved gids too */ 1081 if (decline_attach == 0) 1082 decline_attach = !groupmember(tc->cr_rgid, oc) || 1083 !groupmember(tc->cr_svgid, oc); 1084 1085 crfree(tc); 1086 crfree(oc); 1087 1088 return !decline_attach; 1089 } 1090 1091 /* 1092 * Attach a process to a PMC. 1093 */ 1094 1095 static int 1096 pmc_attach_one_process(struct proc *p, struct pmc *pm) 1097 { 1098 int ri, error; 1099 char *fullpath, *freepath; 1100 struct pmc_process *pp; 1101 1102 sx_assert(&pmc_sx, SX_XLOCKED); 1103 1104 PMCDBG5(PRC,ATT,2, "attach-one pm=%p ri=%d proc=%p (%d, %s)", pm, 1105 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 1106 1107 /* 1108 * Locate the process descriptor corresponding to process 'p', 1109 * allocating space as needed. 1110 * 1111 * Verify that rowindex 'pm_rowindex' is free in the process 1112 * descriptor. 1113 * 1114 * If not, allocate space for a descriptor and link the 1115 * process descriptor and PMC. 1116 */ 1117 ri = PMC_TO_ROWINDEX(pm); 1118 1119 /* mark process as using HWPMCs */ 1120 PROC_LOCK(p); 1121 p->p_flag |= P_HWPMC; 1122 PROC_UNLOCK(p); 1123 1124 if ((pp = pmc_find_process_descriptor(p, PMC_FLAG_ALLOCATE)) == NULL) { 1125 error = ENOMEM; 1126 goto fail; 1127 } 1128 1129 if (pp->pp_pmcs[ri].pp_pmc == pm) {/* already present at slot [ri] */ 1130 error = EEXIST; 1131 goto fail; 1132 } 1133 1134 if (pp->pp_pmcs[ri].pp_pmc != NULL) { 1135 error = EBUSY; 1136 goto fail; 1137 } 1138 1139 pmc_link_target_process(pm, pp); 1140 1141 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)) && 1142 (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) == 0) 1143 pm->pm_flags |= PMC_F_NEEDS_LOGFILE; 1144 1145 pm->pm_flags |= PMC_F_ATTACH_DONE; /* mark as attached */ 1146 1147 /* issue an attach event to a configured log file */ 1148 if (pm->pm_owner->po_flags & PMC_PO_OWNS_LOGFILE) { 1149 if (p->p_flag & P_KPROC) { 1150 fullpath = kernelname; 1151 freepath = NULL; 1152 } else { 1153 pmc_getfilename(p->p_textvp, &fullpath, &freepath); 1154 pmclog_process_pmcattach(pm, p->p_pid, fullpath); 1155 } 1156 free(freepath, M_TEMP); 1157 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 1158 pmc_log_process_mappings(pm->pm_owner, p); 1159 } 1160 1161 return (0); 1162 fail: 1163 PROC_LOCK(p); 1164 p->p_flag &= ~P_HWPMC; 1165 PROC_UNLOCK(p); 1166 return (error); 1167 } 1168 1169 /* 1170 * Attach a process and optionally its children 1171 */ 1172 1173 static int 1174 pmc_attach_process(struct proc *p, struct pmc *pm) 1175 { 1176 int error; 1177 struct proc *top; 1178 1179 sx_assert(&pmc_sx, SX_XLOCKED); 1180 1181 PMCDBG5(PRC,ATT,1, "attach pm=%p ri=%d proc=%p (%d, %s)", pm, 1182 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 1183 1184 1185 /* 1186 * If this PMC successfully allowed a GETMSR operation 1187 * in the past, disallow further ATTACHes. 1188 */ 1189 1190 if ((pm->pm_flags & PMC_PP_ENABLE_MSR_ACCESS) != 0) 1191 return EPERM; 1192 1193 if ((pm->pm_flags & PMC_F_DESCENDANTS) == 0) 1194 return pmc_attach_one_process(p, pm); 1195 1196 /* 1197 * Traverse all child processes, attaching them to 1198 * this PMC. 1199 */ 1200 1201 sx_slock(&proctree_lock); 1202 1203 top = p; 1204 1205 for (;;) { 1206 if ((error = pmc_attach_one_process(p, pm)) != 0) 1207 break; 1208 if (!LIST_EMPTY(&p->p_children)) 1209 p = LIST_FIRST(&p->p_children); 1210 else for (;;) { 1211 if (p == top) 1212 goto done; 1213 if (LIST_NEXT(p, p_sibling)) { 1214 p = LIST_NEXT(p, p_sibling); 1215 break; 1216 } 1217 p = p->p_pptr; 1218 } 1219 } 1220 1221 if (error) 1222 (void) pmc_detach_process(top, pm); 1223 1224 done: 1225 sx_sunlock(&proctree_lock); 1226 return error; 1227 } 1228 1229 /* 1230 * Detach a process from a PMC. If there are no other PMCs tracking 1231 * this process, remove the process structure from its hash table. If 1232 * 'flags' contains PMC_FLAG_REMOVE, then free the process structure. 1233 */ 1234 1235 static int 1236 pmc_detach_one_process(struct proc *p, struct pmc *pm, int flags) 1237 { 1238 int ri; 1239 struct pmc_process *pp; 1240 1241 sx_assert(&pmc_sx, SX_XLOCKED); 1242 1243 KASSERT(pm != NULL, 1244 ("[pmc,%d] null pm pointer", __LINE__)); 1245 1246 ri = PMC_TO_ROWINDEX(pm); 1247 1248 PMCDBG6(PRC,ATT,2, "detach-one pm=%p ri=%d proc=%p (%d, %s) flags=0x%x", 1249 pm, ri, p, p->p_pid, p->p_comm, flags); 1250 1251 if ((pp = pmc_find_process_descriptor(p, 0)) == NULL) 1252 return ESRCH; 1253 1254 if (pp->pp_pmcs[ri].pp_pmc != pm) 1255 return EINVAL; 1256 1257 pmc_unlink_target_process(pm, pp); 1258 1259 /* Issue a detach entry if a log file is configured */ 1260 if (pm->pm_owner->po_flags & PMC_PO_OWNS_LOGFILE) 1261 pmclog_process_pmcdetach(pm, p->p_pid); 1262 1263 /* 1264 * If there are no PMCs targeting this process, we remove its 1265 * descriptor from the target hash table and unset the P_HWPMC 1266 * flag in the struct proc. 1267 */ 1268 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= (int) md->pmd_npmc, 1269 ("[pmc,%d] Illegal refcnt %d for process struct %p", 1270 __LINE__, pp->pp_refcnt, pp)); 1271 1272 if (pp->pp_refcnt != 0) /* still a target of some PMC */ 1273 return 0; 1274 1275 pmc_remove_process_descriptor(pp); 1276 1277 if (flags & PMC_FLAG_REMOVE) 1278 pmc_destroy_process_descriptor(pp); 1279 1280 PROC_LOCK(p); 1281 p->p_flag &= ~P_HWPMC; 1282 PROC_UNLOCK(p); 1283 1284 return 0; 1285 } 1286 1287 /* 1288 * Detach a process and optionally its descendants from a PMC. 1289 */ 1290 1291 static int 1292 pmc_detach_process(struct proc *p, struct pmc *pm) 1293 { 1294 struct proc *top; 1295 1296 sx_assert(&pmc_sx, SX_XLOCKED); 1297 1298 PMCDBG5(PRC,ATT,1, "detach pm=%p ri=%d proc=%p (%d, %s)", pm, 1299 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 1300 1301 if ((pm->pm_flags & PMC_F_DESCENDANTS) == 0) 1302 return pmc_detach_one_process(p, pm, PMC_FLAG_REMOVE); 1303 1304 /* 1305 * Traverse all children, detaching them from this PMC. We 1306 * ignore errors since we could be detaching a PMC from a 1307 * partially attached proc tree. 1308 */ 1309 1310 sx_slock(&proctree_lock); 1311 1312 top = p; 1313 1314 for (;;) { 1315 (void) pmc_detach_one_process(p, pm, PMC_FLAG_REMOVE); 1316 1317 if (!LIST_EMPTY(&p->p_children)) 1318 p = LIST_FIRST(&p->p_children); 1319 else for (;;) { 1320 if (p == top) 1321 goto done; 1322 if (LIST_NEXT(p, p_sibling)) { 1323 p = LIST_NEXT(p, p_sibling); 1324 break; 1325 } 1326 p = p->p_pptr; 1327 } 1328 } 1329 1330 done: 1331 sx_sunlock(&proctree_lock); 1332 1333 if (LIST_EMPTY(&pm->pm_targets)) 1334 pm->pm_flags &= ~PMC_F_ATTACH_DONE; 1335 1336 return 0; 1337 } 1338 1339 1340 /* 1341 * Thread context switch IN 1342 */ 1343 1344 static void 1345 pmc_process_csw_in(struct thread *td) 1346 { 1347 int cpu; 1348 unsigned int adjri, ri; 1349 struct pmc *pm; 1350 struct proc *p; 1351 struct pmc_cpu *pc; 1352 struct pmc_hw *phw; 1353 pmc_value_t newvalue; 1354 struct pmc_process *pp; 1355 struct pmc_thread *pt; 1356 struct pmc_classdep *pcd; 1357 1358 p = td->td_proc; 1359 pt = NULL; 1360 if ((pp = pmc_find_process_descriptor(p, PMC_FLAG_NONE)) == NULL) 1361 return; 1362 1363 KASSERT(pp->pp_proc == td->td_proc, 1364 ("[pmc,%d] not my thread state", __LINE__)); 1365 1366 critical_enter(); /* no preemption from this point */ 1367 1368 cpu = PCPU_GET(cpuid); /* td->td_oncpu is invalid */ 1369 1370 PMCDBG5(CSW,SWI,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p, 1371 p->p_pid, p->p_comm, pp); 1372 1373 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 1374 ("[pmc,%d] weird CPU id %d", __LINE__, cpu)); 1375 1376 pc = pmc_pcpu[cpu]; 1377 1378 for (ri = 0; ri < md->pmd_npmc; ri++) { 1379 1380 if ((pm = pp->pp_pmcs[ri].pp_pmc) == NULL) 1381 continue; 1382 1383 KASSERT(PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)), 1384 ("[pmc,%d] Target PMC in non-virtual mode (%d)", 1385 __LINE__, PMC_TO_MODE(pm))); 1386 1387 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 1388 ("[pmc,%d] Row index mismatch pmc %d != ri %d", 1389 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 1390 1391 /* 1392 * Only PMCs that are marked as 'RUNNING' need 1393 * be placed on hardware. 1394 */ 1395 1396 if (pm->pm_state != PMC_STATE_RUNNING) 1397 continue; 1398 1399 KASSERT(counter_u64_fetch(pm->pm_runcount) >= 0, 1400 ("[pmc,%d] pm=%p runcount %ld", __LINE__, (void *) pm, 1401 (unsigned long)counter_u64_fetch(pm->pm_runcount))); 1402 1403 /* increment PMC runcount */ 1404 counter_u64_add(pm->pm_runcount, 1); 1405 1406 /* configure the HWPMC we are going to use. */ 1407 pcd = pmc_ri_to_classdep(md, ri, &adjri); 1408 pcd->pcd_config_pmc(cpu, adjri, pm); 1409 1410 phw = pc->pc_hwpmcs[ri]; 1411 1412 KASSERT(phw != NULL, 1413 ("[pmc,%d] null hw pointer", __LINE__)); 1414 1415 KASSERT(phw->phw_pmc == pm, 1416 ("[pmc,%d] hw->pmc %p != pmc %p", __LINE__, 1417 phw->phw_pmc, pm)); 1418 1419 /* 1420 * Write out saved value and start the PMC. 1421 * 1422 * Sampling PMCs use a per-thread value, while 1423 * counting mode PMCs use a per-pmc value that is 1424 * inherited across descendants. 1425 */ 1426 if (PMC_TO_MODE(pm) == PMC_MODE_TS) { 1427 if (pt == NULL) 1428 pt = pmc_find_thread_descriptor(pp, td, 1429 PMC_FLAG_NONE); 1430 1431 KASSERT(pt != NULL, 1432 ("[pmc,%d] No thread found for td=%p", __LINE__, 1433 td)); 1434 1435 mtx_pool_lock_spin(pmc_mtxpool, pm); 1436 1437 /* 1438 * If we have a thread descriptor, use the per-thread 1439 * counter in the descriptor. If not, we will use 1440 * a per-process counter. 1441 * 1442 * TODO: Remove the per-process "safety net" once 1443 * we have thoroughly tested that we don't hit the 1444 * above assert. 1445 */ 1446 if (pt != NULL) { 1447 if (pt->pt_pmcs[ri].pt_pmcval > 0) 1448 newvalue = pt->pt_pmcs[ri].pt_pmcval; 1449 else 1450 newvalue = pm->pm_sc.pm_reloadcount; 1451 } else { 1452 /* 1453 * Use the saved value calculated after the most 1454 * recent time a thread using the shared counter 1455 * switched out. Reset the saved count in case 1456 * another thread from this process switches in 1457 * before any threads switch out. 1458 */ 1459 1460 newvalue = pp->pp_pmcs[ri].pp_pmcval; 1461 pp->pp_pmcs[ri].pp_pmcval = 1462 pm->pm_sc.pm_reloadcount; 1463 } 1464 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1465 KASSERT(newvalue > 0 && newvalue <= 1466 pm->pm_sc.pm_reloadcount, 1467 ("[pmc,%d] pmcval outside of expected range cpu=%d " 1468 "ri=%d pmcval=%jx pm_reloadcount=%jx", __LINE__, 1469 cpu, ri, newvalue, pm->pm_sc.pm_reloadcount)); 1470 } else { 1471 KASSERT(PMC_TO_MODE(pm) == PMC_MODE_TC, 1472 ("[pmc,%d] illegal mode=%d", __LINE__, 1473 PMC_TO_MODE(pm))); 1474 mtx_pool_lock_spin(pmc_mtxpool, pm); 1475 newvalue = PMC_PCPU_SAVED(cpu, ri) = 1476 pm->pm_gv.pm_savedvalue; 1477 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1478 } 1479 1480 PMCDBG3(CSW,SWI,1,"cpu=%d ri=%d new=%jd", cpu, ri, newvalue); 1481 1482 pcd->pcd_write_pmc(cpu, adjri, newvalue); 1483 1484 /* If a sampling mode PMC, reset stalled state. */ 1485 if (PMC_TO_MODE(pm) == PMC_MODE_TS) 1486 pm->pm_pcpu_state[cpu].pps_stalled = 0; 1487 1488 /* Indicate that we desire this to run. */ 1489 pm->pm_pcpu_state[cpu].pps_cpustate = 1; 1490 1491 /* Start the PMC. */ 1492 pcd->pcd_start_pmc(cpu, adjri); 1493 } 1494 1495 /* 1496 * perform any other architecture/cpu dependent thread 1497 * switch-in actions. 1498 */ 1499 1500 (void) (*md->pmd_switch_in)(pc, pp); 1501 1502 critical_exit(); 1503 1504 } 1505 1506 /* 1507 * Thread context switch OUT. 1508 */ 1509 1510 static void 1511 pmc_process_csw_out(struct thread *td) 1512 { 1513 int cpu; 1514 int64_t tmp; 1515 struct pmc *pm; 1516 struct proc *p; 1517 enum pmc_mode mode; 1518 struct pmc_cpu *pc; 1519 pmc_value_t newvalue; 1520 unsigned int adjri, ri; 1521 struct pmc_process *pp; 1522 struct pmc_thread *pt = NULL; 1523 struct pmc_classdep *pcd; 1524 1525 1526 /* 1527 * Locate our process descriptor; this may be NULL if 1528 * this process is exiting and we have already removed 1529 * the process from the target process table. 1530 * 1531 * Note that due to kernel preemption, multiple 1532 * context switches may happen while the process is 1533 * exiting. 1534 * 1535 * Note also that if the target process cannot be 1536 * found we still need to deconfigure any PMCs that 1537 * are currently running on hardware. 1538 */ 1539 1540 p = td->td_proc; 1541 pp = pmc_find_process_descriptor(p, PMC_FLAG_NONE); 1542 1543 /* 1544 * save PMCs 1545 */ 1546 1547 critical_enter(); 1548 1549 cpu = PCPU_GET(cpuid); /* td->td_oncpu is invalid */ 1550 1551 PMCDBG5(CSW,SWO,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p, 1552 p->p_pid, p->p_comm, pp); 1553 1554 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 1555 ("[pmc,%d weird CPU id %d", __LINE__, cpu)); 1556 1557 pc = pmc_pcpu[cpu]; 1558 1559 /* 1560 * When a PMC gets unlinked from a target PMC, it will 1561 * be removed from the target's pp_pmc[] array. 1562 * 1563 * However, on a MP system, the target could have been 1564 * executing on another CPU at the time of the unlink. 1565 * So, at context switch OUT time, we need to look at 1566 * the hardware to determine if a PMC is scheduled on 1567 * it. 1568 */ 1569 1570 for (ri = 0; ri < md->pmd_npmc; ri++) { 1571 1572 pcd = pmc_ri_to_classdep(md, ri, &adjri); 1573 pm = NULL; 1574 (void) (*pcd->pcd_get_config)(cpu, adjri, &pm); 1575 1576 if (pm == NULL) /* nothing at this row index */ 1577 continue; 1578 1579 mode = PMC_TO_MODE(pm); 1580 if (!PMC_IS_VIRTUAL_MODE(mode)) 1581 continue; /* not a process virtual PMC */ 1582 1583 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 1584 ("[pmc,%d] ri mismatch pmc(%d) ri(%d)", 1585 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 1586 1587 /* 1588 * Change desired state, and then stop if not stalled. 1589 * This two-step dance should avoid race conditions where 1590 * an interrupt re-enables the PMC after this code has 1591 * already checked the pm_stalled flag. 1592 */ 1593 pm->pm_pcpu_state[cpu].pps_cpustate = 0; 1594 if (pm->pm_pcpu_state[cpu].pps_stalled == 0) 1595 pcd->pcd_stop_pmc(cpu, adjri); 1596 1597 KASSERT(counter_u64_fetch(pm->pm_runcount) > 0, 1598 ("[pmc,%d] pm=%p runcount %ld", __LINE__, (void *) pm, 1599 (unsigned long)counter_u64_fetch(pm->pm_runcount))); 1600 1601 /* reduce this PMC's runcount */ 1602 counter_u64_add(pm->pm_runcount, -1); 1603 1604 /* 1605 * If this PMC is associated with this process, 1606 * save the reading. 1607 */ 1608 1609 if (pm->pm_state != PMC_STATE_DELETED && pp != NULL && 1610 pp->pp_pmcs[ri].pp_pmc != NULL) { 1611 KASSERT(pm == pp->pp_pmcs[ri].pp_pmc, 1612 ("[pmc,%d] pm %p != pp_pmcs[%d] %p", __LINE__, 1613 pm, ri, pp->pp_pmcs[ri].pp_pmc)); 1614 1615 KASSERT(pp->pp_refcnt > 0, 1616 ("[pmc,%d] pp refcnt = %d", __LINE__, 1617 pp->pp_refcnt)); 1618 1619 pcd->pcd_read_pmc(cpu, adjri, &newvalue); 1620 1621 if (mode == PMC_MODE_TS) { 1622 PMCDBG3(CSW,SWO,1,"cpu=%d ri=%d val=%jd (samp)", 1623 cpu, ri, newvalue); 1624 1625 if (pt == NULL) 1626 pt = pmc_find_thread_descriptor(pp, td, 1627 PMC_FLAG_NONE); 1628 1629 KASSERT(pt != NULL, 1630 ("[pmc,%d] No thread found for td=%p", 1631 __LINE__, td)); 1632 1633 mtx_pool_lock_spin(pmc_mtxpool, pm); 1634 1635 /* 1636 * If we have a thread descriptor, save the 1637 * per-thread counter in the descriptor. If not, 1638 * we will update the per-process counter. 1639 * 1640 * TODO: Remove the per-process "safety net" 1641 * once we have thoroughly tested that we 1642 * don't hit the above assert. 1643 */ 1644 if (pt != NULL) 1645 pt->pt_pmcs[ri].pt_pmcval = newvalue; 1646 else { 1647 /* 1648 * For sampling process-virtual PMCs, 1649 * newvalue is the number of events to 1650 * be seen until the next sampling 1651 * interrupt. We can just add the events 1652 * left from this invocation to the 1653 * counter, then adjust in case we 1654 * overflow our range. 1655 * 1656 * (Recall that we reload the counter 1657 * every time we use it.) 1658 */ 1659 pp->pp_pmcs[ri].pp_pmcval += newvalue; 1660 if (pp->pp_pmcs[ri].pp_pmcval > 1661 pm->pm_sc.pm_reloadcount) 1662 pp->pp_pmcs[ri].pp_pmcval -= 1663 pm->pm_sc.pm_reloadcount; 1664 } 1665 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1666 } else { 1667 tmp = newvalue - PMC_PCPU_SAVED(cpu,ri); 1668 1669 PMCDBG3(CSW,SWO,1,"cpu=%d ri=%d tmp=%jd (count)", 1670 cpu, ri, tmp); 1671 1672 /* 1673 * For counting process-virtual PMCs, 1674 * we expect the count to be 1675 * increasing monotonically, modulo a 64 1676 * bit wraparound. 1677 */ 1678 KASSERT(tmp >= 0, 1679 ("[pmc,%d] negative increment cpu=%d " 1680 "ri=%d newvalue=%jx saved=%jx " 1681 "incr=%jx", __LINE__, cpu, ri, 1682 newvalue, PMC_PCPU_SAVED(cpu,ri), tmp)); 1683 1684 mtx_pool_lock_spin(pmc_mtxpool, pm); 1685 pm->pm_gv.pm_savedvalue += tmp; 1686 pp->pp_pmcs[ri].pp_pmcval += tmp; 1687 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1688 1689 if (pm->pm_flags & PMC_F_LOG_PROCCSW) 1690 pmclog_process_proccsw(pm, pp, tmp, td); 1691 } 1692 } 1693 1694 /* mark hardware as free */ 1695 pcd->pcd_config_pmc(cpu, adjri, NULL); 1696 } 1697 1698 /* 1699 * perform any other architecture/cpu dependent thread 1700 * switch out functions. 1701 */ 1702 1703 (void) (*md->pmd_switch_out)(pc, pp); 1704 1705 critical_exit(); 1706 } 1707 1708 /* 1709 * A new thread for a process. 1710 */ 1711 static void 1712 pmc_process_thread_add(struct thread *td) 1713 { 1714 struct pmc_process *pmc; 1715 1716 pmc = pmc_find_process_descriptor(td->td_proc, PMC_FLAG_NONE); 1717 if (pmc != NULL) 1718 pmc_find_thread_descriptor(pmc, td, PMC_FLAG_ALLOCATE); 1719 } 1720 1721 /* 1722 * A thread delete for a process. 1723 */ 1724 static void 1725 pmc_process_thread_delete(struct thread *td) 1726 { 1727 struct pmc_process *pmc; 1728 1729 pmc = pmc_find_process_descriptor(td->td_proc, PMC_FLAG_NONE); 1730 if (pmc != NULL) 1731 pmc_thread_descriptor_pool_free(pmc_find_thread_descriptor(pmc, 1732 td, PMC_FLAG_REMOVE)); 1733 } 1734 1735 /* 1736 * A userret() call for a thread. 1737 */ 1738 static void 1739 pmc_process_thread_userret(struct thread *td) 1740 { 1741 sched_pin(); 1742 pmc_capture_user_callchain(curcpu, PMC_UR, td->td_frame); 1743 sched_unpin(); 1744 } 1745 1746 /* 1747 * A mapping change for a process. 1748 */ 1749 1750 static void 1751 pmc_process_mmap(struct thread *td, struct pmckern_map_in *pkm) 1752 { 1753 int ri; 1754 pid_t pid; 1755 char *fullpath, *freepath; 1756 const struct pmc *pm; 1757 struct pmc_owner *po; 1758 const struct pmc_process *pp; 1759 1760 freepath = fullpath = NULL; 1761 MPASS(!in_epoch(global_epoch_preempt)); 1762 pmc_getfilename((struct vnode *) pkm->pm_file, &fullpath, &freepath); 1763 1764 pid = td->td_proc->p_pid; 1765 1766 PMC_EPOCH_ENTER(); 1767 /* Inform owners of all system-wide sampling PMCs. */ 1768 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1769 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1770 pmclog_process_map_in(po, pid, pkm->pm_address, fullpath); 1771 1772 if ((pp = pmc_find_process_descriptor(td->td_proc, 0)) == NULL) 1773 goto done; 1774 1775 /* 1776 * Inform sampling PMC owners tracking this process. 1777 */ 1778 for (ri = 0; ri < md->pmd_npmc; ri++) 1779 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL && 1780 PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 1781 pmclog_process_map_in(pm->pm_owner, 1782 pid, pkm->pm_address, fullpath); 1783 1784 done: 1785 if (freepath) 1786 free(freepath, M_TEMP); 1787 PMC_EPOCH_EXIT(); 1788 } 1789 1790 1791 /* 1792 * Log an munmap request. 1793 */ 1794 1795 static void 1796 pmc_process_munmap(struct thread *td, struct pmckern_map_out *pkm) 1797 { 1798 int ri; 1799 pid_t pid; 1800 struct pmc_owner *po; 1801 const struct pmc *pm; 1802 const struct pmc_process *pp; 1803 1804 pid = td->td_proc->p_pid; 1805 1806 PMC_EPOCH_ENTER(); 1807 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1808 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1809 pmclog_process_map_out(po, pid, pkm->pm_address, 1810 pkm->pm_address + pkm->pm_size); 1811 PMC_EPOCH_EXIT(); 1812 1813 if ((pp = pmc_find_process_descriptor(td->td_proc, 0)) == NULL) 1814 return; 1815 1816 for (ri = 0; ri < md->pmd_npmc; ri++) 1817 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL && 1818 PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 1819 pmclog_process_map_out(pm->pm_owner, pid, 1820 pkm->pm_address, pkm->pm_address + pkm->pm_size); 1821 } 1822 1823 /* 1824 * Log mapping information about the kernel. 1825 */ 1826 1827 static void 1828 pmc_log_kernel_mappings(struct pmc *pm) 1829 { 1830 struct pmc_owner *po; 1831 struct pmckern_map_in *km, *kmbase; 1832 1833 MPASS(in_epoch(global_epoch_preempt) || sx_xlocked(&pmc_sx)); 1834 KASSERT(PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)), 1835 ("[pmc,%d] non-sampling PMC (%p) desires mapping information", 1836 __LINE__, (void *) pm)); 1837 1838 po = pm->pm_owner; 1839 1840 if (po->po_flags & PMC_PO_INITIAL_MAPPINGS_DONE) 1841 return; 1842 if (PMC_TO_MODE(pm) == PMC_MODE_SS) 1843 pmc_process_allproc(pm); 1844 /* 1845 * Log the current set of kernel modules. 1846 */ 1847 kmbase = linker_hwpmc_list_objects(); 1848 for (km = kmbase; km->pm_file != NULL; km++) { 1849 PMCDBG2(LOG,REG,1,"%s %p", (char *) km->pm_file, 1850 (void *) km->pm_address); 1851 pmclog_process_map_in(po, (pid_t) -1, km->pm_address, 1852 km->pm_file); 1853 } 1854 free(kmbase, M_LINKER); 1855 1856 po->po_flags |= PMC_PO_INITIAL_MAPPINGS_DONE; 1857 } 1858 1859 /* 1860 * Log the mappings for a single process. 1861 */ 1862 1863 static void 1864 pmc_log_process_mappings(struct pmc_owner *po, struct proc *p) 1865 { 1866 vm_map_t map; 1867 struct vnode *vp; 1868 struct vmspace *vm; 1869 vm_map_entry_t entry; 1870 vm_offset_t last_end; 1871 u_int last_timestamp; 1872 struct vnode *last_vp; 1873 vm_offset_t start_addr; 1874 vm_object_t obj, lobj, tobj; 1875 char *fullpath, *freepath; 1876 1877 last_vp = NULL; 1878 last_end = (vm_offset_t) 0; 1879 fullpath = freepath = NULL; 1880 1881 if ((vm = vmspace_acquire_ref(p)) == NULL) 1882 return; 1883 1884 map = &vm->vm_map; 1885 vm_map_lock_read(map); 1886 1887 for (entry = map->header.next; entry != &map->header; entry = entry->next) { 1888 1889 if (entry == NULL) { 1890 PMCDBG2(LOG,OPS,2, "hwpmc: vm_map entry unexpectedly " 1891 "NULL! pid=%d vm_map=%p\n", p->p_pid, map); 1892 break; 1893 } 1894 1895 /* 1896 * We only care about executable map entries. 1897 */ 1898 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) || 1899 !(entry->protection & VM_PROT_EXECUTE) || 1900 (entry->object.vm_object == NULL)) { 1901 continue; 1902 } 1903 1904 obj = entry->object.vm_object; 1905 VM_OBJECT_RLOCK(obj); 1906 1907 /* 1908 * Walk the backing_object list to find the base 1909 * (non-shadowed) vm_object. 1910 */ 1911 for (lobj = tobj = obj; tobj != NULL; tobj = tobj->backing_object) { 1912 if (tobj != obj) 1913 VM_OBJECT_RLOCK(tobj); 1914 if (lobj != obj) 1915 VM_OBJECT_RUNLOCK(lobj); 1916 lobj = tobj; 1917 } 1918 1919 /* 1920 * At this point lobj is the base vm_object and it is locked. 1921 */ 1922 if (lobj == NULL) { 1923 PMCDBG3(LOG,OPS,2, "hwpmc: lobj unexpectedly NULL! pid=%d " 1924 "vm_map=%p vm_obj=%p\n", p->p_pid, map, obj); 1925 VM_OBJECT_RUNLOCK(obj); 1926 continue; 1927 } 1928 1929 vp = vm_object_vnode(lobj); 1930 if (vp == NULL) { 1931 if (lobj != obj) 1932 VM_OBJECT_RUNLOCK(lobj); 1933 VM_OBJECT_RUNLOCK(obj); 1934 continue; 1935 } 1936 1937 /* 1938 * Skip contiguous regions that point to the same 1939 * vnode, so we don't emit redundant MAP-IN 1940 * directives. 1941 */ 1942 if (entry->start == last_end && vp == last_vp) { 1943 last_end = entry->end; 1944 if (lobj != obj) 1945 VM_OBJECT_RUNLOCK(lobj); 1946 VM_OBJECT_RUNLOCK(obj); 1947 continue; 1948 } 1949 1950 /* 1951 * We don't want to keep the proc's vm_map or this 1952 * vm_object locked while we walk the pathname, since 1953 * vn_fullpath() can sleep. However, if we drop the 1954 * lock, it's possible for concurrent activity to 1955 * modify the vm_map list. To protect against this, 1956 * we save the vm_map timestamp before we release the 1957 * lock, and check it after we reacquire the lock 1958 * below. 1959 */ 1960 start_addr = entry->start; 1961 last_end = entry->end; 1962 last_timestamp = map->timestamp; 1963 vm_map_unlock_read(map); 1964 1965 vref(vp); 1966 if (lobj != obj) 1967 VM_OBJECT_RUNLOCK(lobj); 1968 1969 VM_OBJECT_RUNLOCK(obj); 1970 1971 freepath = NULL; 1972 pmc_getfilename(vp, &fullpath, &freepath); 1973 last_vp = vp; 1974 1975 vrele(vp); 1976 1977 vp = NULL; 1978 pmclog_process_map_in(po, p->p_pid, start_addr, fullpath); 1979 if (freepath) 1980 free(freepath, M_TEMP); 1981 1982 vm_map_lock_read(map); 1983 1984 /* 1985 * If our saved timestamp doesn't match, this means 1986 * that the vm_map was modified out from under us and 1987 * we can't trust our current "entry" pointer. Do a 1988 * new lookup for this entry. If there is no entry 1989 * for this address range, vm_map_lookup_entry() will 1990 * return the previous one, so we always want to go to 1991 * entry->next on the next loop iteration. 1992 * 1993 * There is an edge condition here that can occur if 1994 * there is no entry at or before this address. In 1995 * this situation, vm_map_lookup_entry returns 1996 * &map->header, which would cause our loop to abort 1997 * without processing the rest of the map. However, 1998 * in practice this will never happen for process 1999 * vm_map. This is because the executable's text 2000 * segment is the first mapping in the proc's address 2001 * space, and this mapping is never removed until the 2002 * process exits, so there will always be a non-header 2003 * entry at or before the requested address for 2004 * vm_map_lookup_entry to return. 2005 */ 2006 if (map->timestamp != last_timestamp) 2007 vm_map_lookup_entry(map, last_end - 1, &entry); 2008 } 2009 2010 vm_map_unlock_read(map); 2011 vmspace_free(vm); 2012 return; 2013 } 2014 2015 /* 2016 * Log mappings for all processes in the system. 2017 */ 2018 2019 static void 2020 pmc_log_all_process_mappings(struct pmc_owner *po) 2021 { 2022 struct proc *p, *top; 2023 2024 sx_assert(&pmc_sx, SX_XLOCKED); 2025 2026 if ((p = pfind(1)) == NULL) 2027 panic("[pmc,%d] Cannot find init", __LINE__); 2028 2029 PROC_UNLOCK(p); 2030 2031 sx_slock(&proctree_lock); 2032 2033 top = p; 2034 2035 for (;;) { 2036 pmc_log_process_mappings(po, p); 2037 if (!LIST_EMPTY(&p->p_children)) 2038 p = LIST_FIRST(&p->p_children); 2039 else for (;;) { 2040 if (p == top) 2041 goto done; 2042 if (LIST_NEXT(p, p_sibling)) { 2043 p = LIST_NEXT(p, p_sibling); 2044 break; 2045 } 2046 p = p->p_pptr; 2047 } 2048 } 2049 done: 2050 sx_sunlock(&proctree_lock); 2051 } 2052 2053 /* 2054 * The 'hook' invoked from the kernel proper 2055 */ 2056 2057 2058 #ifdef HWPMC_DEBUG 2059 const char *pmc_hooknames[] = { 2060 /* these strings correspond to PMC_FN_* in <sys/pmckern.h> */ 2061 "", 2062 "EXEC", 2063 "CSW-IN", 2064 "CSW-OUT", 2065 "SAMPLE", 2066 "UNUSED1", 2067 "UNUSED2", 2068 "MMAP", 2069 "MUNMAP", 2070 "CALLCHAIN-NMI", 2071 "CALLCHAIN-SOFT", 2072 "SOFTSAMPLING", 2073 "THR-CREATE", 2074 "THR-EXIT", 2075 "THR-USERRET", 2076 "THR-CREATE-LOG", 2077 "THR-EXIT-LOG", 2078 "PROC-CREATE-LOG" 2079 }; 2080 #endif 2081 2082 static int 2083 pmc_hook_handler(struct thread *td, int function, void *arg) 2084 { 2085 int cpu; 2086 2087 PMCDBG4(MOD,PMH,1, "hook td=%p func=%d \"%s\" arg=%p", td, function, 2088 pmc_hooknames[function], arg); 2089 2090 switch (function) 2091 { 2092 2093 /* 2094 * Process exec() 2095 */ 2096 2097 case PMC_FN_PROCESS_EXEC: 2098 { 2099 char *fullpath, *freepath; 2100 unsigned int ri; 2101 int is_using_hwpmcs; 2102 struct pmc *pm; 2103 struct proc *p; 2104 struct pmc_owner *po; 2105 struct pmc_process *pp; 2106 struct pmckern_procexec *pk; 2107 2108 sx_assert(&pmc_sx, SX_XLOCKED); 2109 2110 p = td->td_proc; 2111 pmc_getfilename(p->p_textvp, &fullpath, &freepath); 2112 2113 pk = (struct pmckern_procexec *) arg; 2114 2115 PMC_EPOCH_ENTER(); 2116 /* Inform owners of SS mode PMCs of the exec event. */ 2117 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 2118 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 2119 pmclog_process_procexec(po, PMC_ID_INVALID, 2120 p->p_pid, pk->pm_entryaddr, fullpath); 2121 PMC_EPOCH_EXIT(); 2122 2123 PROC_LOCK(p); 2124 is_using_hwpmcs = p->p_flag & P_HWPMC; 2125 PROC_UNLOCK(p); 2126 2127 if (!is_using_hwpmcs) { 2128 if (freepath) 2129 free(freepath, M_TEMP); 2130 break; 2131 } 2132 2133 /* 2134 * PMCs are not inherited across an exec(): remove any 2135 * PMCs that this process is the owner of. 2136 */ 2137 2138 if ((po = pmc_find_owner_descriptor(p)) != NULL) { 2139 pmc_remove_owner(po); 2140 pmc_destroy_owner_descriptor(po); 2141 } 2142 2143 /* 2144 * If the process being exec'ed is not the target of any 2145 * PMC, we are done. 2146 */ 2147 if ((pp = pmc_find_process_descriptor(p, 0)) == NULL) { 2148 if (freepath) 2149 free(freepath, M_TEMP); 2150 break; 2151 } 2152 2153 /* 2154 * Log the exec event to all monitoring owners. Skip 2155 * owners who have already received the event because 2156 * they had system sampling PMCs active. 2157 */ 2158 for (ri = 0; ri < md->pmd_npmc; ri++) 2159 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) { 2160 po = pm->pm_owner; 2161 if (po->po_sscount == 0 && 2162 po->po_flags & PMC_PO_OWNS_LOGFILE) 2163 pmclog_process_procexec(po, pm->pm_id, 2164 p->p_pid, pk->pm_entryaddr, 2165 fullpath); 2166 } 2167 2168 if (freepath) 2169 free(freepath, M_TEMP); 2170 2171 2172 PMCDBG4(PRC,EXC,1, "exec proc=%p (%d, %s) cred-changed=%d", 2173 p, p->p_pid, p->p_comm, pk->pm_credentialschanged); 2174 2175 if (pk->pm_credentialschanged == 0) /* no change */ 2176 break; 2177 2178 /* 2179 * If the newly exec()'ed process has a different credential 2180 * than before, allow it to be the target of a PMC only if 2181 * the PMC's owner has sufficient privilege. 2182 */ 2183 2184 for (ri = 0; ri < md->pmd_npmc; ri++) 2185 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) 2186 if (pmc_can_attach(pm, td->td_proc) != 0) 2187 pmc_detach_one_process(td->td_proc, 2188 pm, PMC_FLAG_NONE); 2189 2190 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= (int) md->pmd_npmc, 2191 ("[pmc,%d] Illegal ref count %d on pp %p", __LINE__, 2192 pp->pp_refcnt, pp)); 2193 2194 /* 2195 * If this process is no longer the target of any 2196 * PMCs, we can remove the process entry and free 2197 * up space. 2198 */ 2199 2200 if (pp->pp_refcnt == 0) { 2201 pmc_remove_process_descriptor(pp); 2202 pmc_destroy_process_descriptor(pp); 2203 break; 2204 } 2205 2206 } 2207 break; 2208 2209 case PMC_FN_CSW_IN: 2210 pmc_process_csw_in(td); 2211 break; 2212 2213 case PMC_FN_CSW_OUT: 2214 pmc_process_csw_out(td); 2215 break; 2216 2217 /* 2218 * Process accumulated PC samples. 2219 * 2220 * This function is expected to be called by hardclock() for 2221 * each CPU that has accumulated PC samples. 2222 * 2223 * This function is to be executed on the CPU whose samples 2224 * are being processed. 2225 */ 2226 case PMC_FN_DO_SAMPLES: 2227 2228 /* 2229 * Clear the cpu specific bit in the CPU mask before 2230 * do the rest of the processing. If the NMI handler 2231 * gets invoked after the "atomic_clear_int()" call 2232 * below but before "pmc_process_samples()" gets 2233 * around to processing the interrupt, then we will 2234 * come back here at the next hardclock() tick (and 2235 * may find nothing to do if "pmc_process_samples()" 2236 * had already processed the interrupt). We don't 2237 * lose the interrupt sample. 2238 */ 2239 DPCPU_SET(pmc_sampled, 0); 2240 cpu = PCPU_GET(cpuid); 2241 pmc_process_samples(cpu, PMC_HR); 2242 pmc_process_samples(cpu, PMC_SR); 2243 pmc_process_samples(cpu, PMC_UR); 2244 break; 2245 2246 case PMC_FN_MMAP: 2247 pmc_process_mmap(td, (struct pmckern_map_in *) arg); 2248 break; 2249 2250 case PMC_FN_MUNMAP: 2251 MPASS(in_epoch(global_epoch_preempt) || sx_xlocked(&pmc_sx)); 2252 pmc_process_munmap(td, (struct pmckern_map_out *) arg); 2253 break; 2254 2255 case PMC_FN_PROC_CREATE_LOG: 2256 pmc_process_proccreate((struct proc *)arg); 2257 break; 2258 2259 case PMC_FN_USER_CALLCHAIN: 2260 /* 2261 * Record a call chain. 2262 */ 2263 KASSERT(td == curthread, ("[pmc,%d] td != curthread", 2264 __LINE__)); 2265 2266 pmc_capture_user_callchain(PCPU_GET(cpuid), PMC_HR, 2267 (struct trapframe *) arg); 2268 2269 KASSERT(td->td_pinned == 1, 2270 ("[pmc,%d] invalid td_pinned value", __LINE__)); 2271 sched_unpin(); /* Can migrate safely now. */ 2272 2273 td->td_pflags &= ~TDP_CALLCHAIN; 2274 break; 2275 2276 case PMC_FN_USER_CALLCHAIN_SOFT: 2277 /* 2278 * Record a call chain. 2279 */ 2280 KASSERT(td == curthread, ("[pmc,%d] td != curthread", 2281 __LINE__)); 2282 2283 cpu = PCPU_GET(cpuid); 2284 pmc_capture_user_callchain(cpu, PMC_SR, 2285 (struct trapframe *) arg); 2286 2287 KASSERT(td->td_pinned == 1, 2288 ("[pmc,%d] invalid td_pinned value", __LINE__)); 2289 2290 sched_unpin(); /* Can migrate safely now. */ 2291 2292 td->td_pflags &= ~TDP_CALLCHAIN; 2293 break; 2294 2295 case PMC_FN_SOFT_SAMPLING: 2296 /* 2297 * Call soft PMC sampling intr. 2298 */ 2299 pmc_soft_intr((struct pmckern_soft *) arg); 2300 break; 2301 2302 case PMC_FN_THR_CREATE: 2303 pmc_process_thread_add(td); 2304 pmc_process_threadcreate(td); 2305 break; 2306 2307 case PMC_FN_THR_CREATE_LOG: 2308 pmc_process_threadcreate(td); 2309 break; 2310 2311 case PMC_FN_THR_EXIT: 2312 KASSERT(td == curthread, ("[pmc,%d] td != curthread", 2313 __LINE__)); 2314 pmc_process_thread_delete(td); 2315 pmc_process_threadexit(td); 2316 break; 2317 case PMC_FN_THR_EXIT_LOG: 2318 pmc_process_threadexit(td); 2319 break; 2320 case PMC_FN_THR_USERRET: 2321 KASSERT(td == curthread, ("[pmc,%d] td != curthread", 2322 __LINE__)); 2323 pmc_process_thread_userret(td); 2324 break; 2325 2326 default: 2327 #ifdef HWPMC_DEBUG 2328 KASSERT(0, ("[pmc,%d] unknown hook %d\n", __LINE__, function)); 2329 #endif 2330 break; 2331 2332 } 2333 2334 return 0; 2335 } 2336 2337 /* 2338 * allocate a 'struct pmc_owner' descriptor in the owner hash table. 2339 */ 2340 2341 static struct pmc_owner * 2342 pmc_allocate_owner_descriptor(struct proc *p) 2343 { 2344 uint32_t hindex; 2345 struct pmc_owner *po; 2346 struct pmc_ownerhash *poh; 2347 2348 hindex = PMC_HASH_PTR(p, pmc_ownerhashmask); 2349 poh = &pmc_ownerhash[hindex]; 2350 2351 /* allocate space for N pointers and one descriptor struct */ 2352 po = malloc(sizeof(struct pmc_owner), M_PMC, M_WAITOK|M_ZERO); 2353 po->po_owner = p; 2354 LIST_INSERT_HEAD(poh, po, po_next); /* insert into hash table */ 2355 2356 TAILQ_INIT(&po->po_logbuffers); 2357 mtx_init(&po->po_mtx, "pmc-owner-mtx", "pmc-per-proc", MTX_SPIN); 2358 2359 PMCDBG4(OWN,ALL,1, "allocate-owner proc=%p (%d, %s) pmc-owner=%p", 2360 p, p->p_pid, p->p_comm, po); 2361 2362 return po; 2363 } 2364 2365 static void 2366 pmc_destroy_owner_descriptor(struct pmc_owner *po) 2367 { 2368 2369 PMCDBG4(OWN,REL,1, "destroy-owner po=%p proc=%p (%d, %s)", 2370 po, po->po_owner, po->po_owner->p_pid, po->po_owner->p_comm); 2371 2372 mtx_destroy(&po->po_mtx); 2373 free(po, M_PMC); 2374 } 2375 2376 /* 2377 * Allocate a thread descriptor from the free pool. 2378 * 2379 * NOTE: This *can* return NULL. 2380 */ 2381 static struct pmc_thread * 2382 pmc_thread_descriptor_pool_alloc(void) 2383 { 2384 struct pmc_thread *pt; 2385 2386 mtx_lock_spin(&pmc_threadfreelist_mtx); 2387 if ((pt = LIST_FIRST(&pmc_threadfreelist)) != NULL) { 2388 LIST_REMOVE(pt, pt_next); 2389 pmc_threadfreelist_entries--; 2390 } 2391 mtx_unlock_spin(&pmc_threadfreelist_mtx); 2392 2393 return (pt); 2394 } 2395 2396 /* 2397 * Add a thread descriptor to the free pool. We use this instead of free() 2398 * to maintain a cache of free entries. Additionally, we can safely call 2399 * this function when we cannot call free(), such as in a critical section. 2400 * 2401 */ 2402 static void 2403 pmc_thread_descriptor_pool_free(struct pmc_thread *pt) 2404 { 2405 2406 if (pt == NULL) 2407 return; 2408 2409 memset(pt, 0, THREADENTRY_SIZE); 2410 mtx_lock_spin(&pmc_threadfreelist_mtx); 2411 LIST_INSERT_HEAD(&pmc_threadfreelist, pt, pt_next); 2412 pmc_threadfreelist_entries++; 2413 if (pmc_threadfreelist_entries > pmc_threadfreelist_max) 2414 GROUPTASK_ENQUEUE(&free_gtask); 2415 mtx_unlock_spin(&pmc_threadfreelist_mtx); 2416 } 2417 2418 /* 2419 * A callout to manage the free list. 2420 */ 2421 static void 2422 pmc_thread_descriptor_pool_free_task(void *arg __unused) 2423 { 2424 struct pmc_thread *pt; 2425 LIST_HEAD(, pmc_thread) tmplist; 2426 int delta; 2427 2428 LIST_INIT(&tmplist); 2429 /* Determine what changes, if any, we need to make. */ 2430 mtx_lock_spin(&pmc_threadfreelist_mtx); 2431 delta = pmc_threadfreelist_entries - pmc_threadfreelist_max; 2432 while (delta > 0 && 2433 (pt = LIST_FIRST(&pmc_threadfreelist)) != NULL) { 2434 delta--; 2435 LIST_REMOVE(pt, pt_next); 2436 LIST_INSERT_HEAD(&tmplist, pt, pt_next); 2437 } 2438 mtx_unlock_spin(&pmc_threadfreelist_mtx); 2439 2440 /* If there are entries to free, free them. */ 2441 while (!LIST_EMPTY(&tmplist)) { 2442 pt = LIST_FIRST(&tmplist); 2443 LIST_REMOVE(pt, pt_next); 2444 free(pt, M_PMC); 2445 } 2446 } 2447 2448 /* 2449 * Drain the thread free pool, freeing all allocations. 2450 */ 2451 static void 2452 pmc_thread_descriptor_pool_drain() 2453 { 2454 struct pmc_thread *pt, *next; 2455 2456 LIST_FOREACH_SAFE(pt, &pmc_threadfreelist, pt_next, next) { 2457 LIST_REMOVE(pt, pt_next); 2458 free(pt, M_PMC); 2459 } 2460 } 2461 2462 /* 2463 * find the descriptor corresponding to thread 'td', adding or removing it 2464 * as specified by 'mode'. 2465 * 2466 * Note that this supports additional mode flags in addition to those 2467 * supported by pmc_find_process_descriptor(): 2468 * PMC_FLAG_NOWAIT: Causes the function to not wait for mallocs. 2469 * This makes it safe to call while holding certain other locks. 2470 */ 2471 2472 static struct pmc_thread * 2473 pmc_find_thread_descriptor(struct pmc_process *pp, struct thread *td, 2474 uint32_t mode) 2475 { 2476 struct pmc_thread *pt = NULL, *ptnew = NULL; 2477 int wait_flag; 2478 2479 KASSERT(td != NULL, ("[pmc,%d] called to add NULL td", __LINE__)); 2480 2481 /* 2482 * Pre-allocate memory in the PMC_FLAG_ALLOCATE case prior to 2483 * acquiring the lock. 2484 */ 2485 if (mode & PMC_FLAG_ALLOCATE) { 2486 if ((ptnew = pmc_thread_descriptor_pool_alloc()) == NULL) { 2487 wait_flag = M_WAITOK; 2488 if ((mode & PMC_FLAG_NOWAIT) || in_epoch(global_epoch_preempt)) 2489 wait_flag = M_NOWAIT; 2490 2491 ptnew = malloc(THREADENTRY_SIZE, M_PMC, 2492 wait_flag|M_ZERO); 2493 } 2494 } 2495 2496 mtx_lock_spin(pp->pp_tdslock); 2497 2498 LIST_FOREACH(pt, &pp->pp_tds, pt_next) 2499 if (pt->pt_td == td) 2500 break; 2501 2502 if ((mode & PMC_FLAG_REMOVE) && pt != NULL) 2503 LIST_REMOVE(pt, pt_next); 2504 2505 if ((mode & PMC_FLAG_ALLOCATE) && pt == NULL && ptnew != NULL) { 2506 pt = ptnew; 2507 ptnew = NULL; 2508 pt->pt_td = td; 2509 LIST_INSERT_HEAD(&pp->pp_tds, pt, pt_next); 2510 } 2511 2512 mtx_unlock_spin(pp->pp_tdslock); 2513 2514 if (ptnew != NULL) { 2515 free(ptnew, M_PMC); 2516 } 2517 2518 return pt; 2519 } 2520 2521 /* 2522 * Try to add thread descriptors for each thread in a process. 2523 */ 2524 2525 static void 2526 pmc_add_thread_descriptors_from_proc(struct proc *p, struct pmc_process *pp) 2527 { 2528 struct thread *curtd; 2529 struct pmc_thread **tdlist; 2530 int i, tdcnt, tdlistsz; 2531 2532 KASSERT(!PROC_LOCKED(p), ("[pmc,%d] proc unexpectedly locked", 2533 __LINE__)); 2534 tdcnt = 32; 2535 restart: 2536 tdlistsz = roundup2(tdcnt, 32); 2537 2538 tdcnt = 0; 2539 tdlist = malloc(sizeof(struct pmc_thread*) * tdlistsz, M_TEMP, M_WAITOK); 2540 2541 PROC_LOCK(p); 2542 FOREACH_THREAD_IN_PROC(p, curtd) 2543 tdcnt++; 2544 if (tdcnt >= tdlistsz) { 2545 PROC_UNLOCK(p); 2546 free(tdlist, M_TEMP); 2547 goto restart; 2548 } 2549 /* 2550 * Try to add each thread to the list without sleeping. If unable, 2551 * add to a queue to retry after dropping the process lock. 2552 */ 2553 tdcnt = 0; 2554 FOREACH_THREAD_IN_PROC(p, curtd) { 2555 tdlist[tdcnt] = pmc_find_thread_descriptor(pp, curtd, 2556 PMC_FLAG_ALLOCATE|PMC_FLAG_NOWAIT); 2557 if (tdlist[tdcnt] == NULL) { 2558 PROC_UNLOCK(p); 2559 for (i = 0; i <= tdcnt; i++) 2560 pmc_thread_descriptor_pool_free(tdlist[i]); 2561 free(tdlist, M_TEMP); 2562 goto restart; 2563 } 2564 tdcnt++; 2565 } 2566 PROC_UNLOCK(p); 2567 free(tdlist, M_TEMP); 2568 } 2569 2570 /* 2571 * find the descriptor corresponding to process 'p', adding or removing it 2572 * as specified by 'mode'. 2573 */ 2574 2575 static struct pmc_process * 2576 pmc_find_process_descriptor(struct proc *p, uint32_t mode) 2577 { 2578 uint32_t hindex; 2579 struct pmc_process *pp, *ppnew; 2580 struct pmc_processhash *pph; 2581 2582 hindex = PMC_HASH_PTR(p, pmc_processhashmask); 2583 pph = &pmc_processhash[hindex]; 2584 2585 ppnew = NULL; 2586 2587 /* 2588 * Pre-allocate memory in the PMC_FLAG_ALLOCATE case since we 2589 * cannot call malloc(9) once we hold a spin lock. 2590 */ 2591 if (mode & PMC_FLAG_ALLOCATE) 2592 ppnew = malloc(sizeof(struct pmc_process) + md->pmd_npmc * 2593 sizeof(struct pmc_targetstate), M_PMC, M_WAITOK|M_ZERO); 2594 2595 mtx_lock_spin(&pmc_processhash_mtx); 2596 LIST_FOREACH(pp, pph, pp_next) 2597 if (pp->pp_proc == p) 2598 break; 2599 2600 if ((mode & PMC_FLAG_REMOVE) && pp != NULL) 2601 LIST_REMOVE(pp, pp_next); 2602 2603 if ((mode & PMC_FLAG_ALLOCATE) && pp == NULL && 2604 ppnew != NULL) { 2605 ppnew->pp_proc = p; 2606 LIST_INIT(&ppnew->pp_tds); 2607 ppnew->pp_tdslock = mtx_pool_find(pmc_mtxpool, ppnew); 2608 LIST_INSERT_HEAD(pph, ppnew, pp_next); 2609 mtx_unlock_spin(&pmc_processhash_mtx); 2610 pp = ppnew; 2611 ppnew = NULL; 2612 2613 /* Add thread descriptors for this process' current threads. */ 2614 pmc_add_thread_descriptors_from_proc(p, pp); 2615 } 2616 else 2617 mtx_unlock_spin(&pmc_processhash_mtx); 2618 2619 if (ppnew != NULL) 2620 free(ppnew, M_PMC); 2621 2622 return pp; 2623 } 2624 2625 /* 2626 * remove a process descriptor from the process hash table. 2627 */ 2628 2629 static void 2630 pmc_remove_process_descriptor(struct pmc_process *pp) 2631 { 2632 KASSERT(pp->pp_refcnt == 0, 2633 ("[pmc,%d] Removing process descriptor %p with count %d", 2634 __LINE__, pp, pp->pp_refcnt)); 2635 2636 mtx_lock_spin(&pmc_processhash_mtx); 2637 LIST_REMOVE(pp, pp_next); 2638 mtx_unlock_spin(&pmc_processhash_mtx); 2639 } 2640 2641 /* 2642 * destroy a process descriptor. 2643 */ 2644 2645 static void 2646 pmc_destroy_process_descriptor(struct pmc_process *pp) 2647 { 2648 struct pmc_thread *pmc_td; 2649 2650 while ((pmc_td = LIST_FIRST(&pp->pp_tds)) != NULL) { 2651 LIST_REMOVE(pmc_td, pt_next); 2652 pmc_thread_descriptor_pool_free(pmc_td); 2653 } 2654 free(pp, M_PMC); 2655 } 2656 2657 2658 /* 2659 * find an owner descriptor corresponding to proc 'p' 2660 */ 2661 2662 static struct pmc_owner * 2663 pmc_find_owner_descriptor(struct proc *p) 2664 { 2665 uint32_t hindex; 2666 struct pmc_owner *po; 2667 struct pmc_ownerhash *poh; 2668 2669 hindex = PMC_HASH_PTR(p, pmc_ownerhashmask); 2670 poh = &pmc_ownerhash[hindex]; 2671 2672 po = NULL; 2673 LIST_FOREACH(po, poh, po_next) 2674 if (po->po_owner == p) 2675 break; 2676 2677 PMCDBG5(OWN,FND,1, "find-owner proc=%p (%d, %s) hindex=0x%x -> " 2678 "pmc-owner=%p", p, p->p_pid, p->p_comm, hindex, po); 2679 2680 return po; 2681 } 2682 2683 /* 2684 * pmc_allocate_pmc_descriptor 2685 * 2686 * Allocate a pmc descriptor and initialize its 2687 * fields. 2688 */ 2689 2690 static struct pmc * 2691 pmc_allocate_pmc_descriptor(void) 2692 { 2693 struct pmc *pmc; 2694 2695 pmc = malloc(sizeof(struct pmc), M_PMC, M_WAITOK|M_ZERO); 2696 pmc->pm_runcount = counter_u64_alloc(M_WAITOK); 2697 pmc->pm_pcpu_state = malloc(sizeof(struct pmc_pcpu_state)*mp_ncpus, M_PMC, M_WAITOK|M_ZERO); 2698 PMCDBG1(PMC,ALL,1, "allocate-pmc -> pmc=%p", pmc); 2699 2700 return pmc; 2701 } 2702 2703 /* 2704 * Destroy a pmc descriptor. 2705 */ 2706 2707 static void 2708 pmc_destroy_pmc_descriptor(struct pmc *pm) 2709 { 2710 2711 KASSERT(pm->pm_state == PMC_STATE_DELETED || 2712 pm->pm_state == PMC_STATE_FREE, 2713 ("[pmc,%d] destroying non-deleted PMC", __LINE__)); 2714 KASSERT(LIST_EMPTY(&pm->pm_targets), 2715 ("[pmc,%d] destroying pmc with targets", __LINE__)); 2716 KASSERT(pm->pm_owner == NULL, 2717 ("[pmc,%d] destroying pmc attached to an owner", __LINE__)); 2718 KASSERT(counter_u64_fetch(pm->pm_runcount) == 0, 2719 ("[pmc,%d] pmc has non-zero run count %ld", __LINE__, 2720 (unsigned long)counter_u64_fetch(pm->pm_runcount))); 2721 2722 counter_u64_free(pm->pm_runcount); 2723 free(pm->pm_pcpu_state, M_PMC); 2724 free(pm, M_PMC); 2725 } 2726 2727 static void 2728 pmc_wait_for_pmc_idle(struct pmc *pm) 2729 { 2730 #ifdef INVARIANTS 2731 volatile int maxloop; 2732 2733 maxloop = 100 * pmc_cpu_max(); 2734 #endif 2735 /* 2736 * Loop (with a forced context switch) till the PMC's runcount 2737 * comes down to zero. 2738 */ 2739 pmclog_flush(pm->pm_owner, 1); 2740 while (counter_u64_fetch(pm->pm_runcount) > 0) { 2741 pmclog_flush(pm->pm_owner, 1); 2742 #ifdef INVARIANTS 2743 maxloop--; 2744 KASSERT(maxloop > 0, 2745 ("[pmc,%d] (ri%d, rc%ld) waiting too long for " 2746 "pmc to be free", __LINE__, 2747 PMC_TO_ROWINDEX(pm), (unsigned long)counter_u64_fetch(pm->pm_runcount))); 2748 #endif 2749 pmc_force_context_switch(); 2750 } 2751 } 2752 2753 /* 2754 * This function does the following things: 2755 * 2756 * - detaches the PMC from hardware 2757 * - unlinks all target threads that were attached to it 2758 * - removes the PMC from its owner's list 2759 * - destroys the PMC private mutex 2760 * 2761 * Once this function completes, the given pmc pointer can be freed by 2762 * calling pmc_destroy_pmc_descriptor(). 2763 */ 2764 2765 static void 2766 pmc_release_pmc_descriptor(struct pmc *pm) 2767 { 2768 enum pmc_mode mode; 2769 struct pmc_hw *phw; 2770 u_int adjri, ri, cpu; 2771 struct pmc_owner *po; 2772 struct pmc_binding pb; 2773 struct pmc_process *pp; 2774 struct pmc_classdep *pcd; 2775 struct pmc_target *ptgt, *tmp; 2776 2777 sx_assert(&pmc_sx, SX_XLOCKED); 2778 2779 KASSERT(pm, ("[pmc,%d] null pmc", __LINE__)); 2780 2781 ri = PMC_TO_ROWINDEX(pm); 2782 pcd = pmc_ri_to_classdep(md, ri, &adjri); 2783 mode = PMC_TO_MODE(pm); 2784 2785 PMCDBG3(PMC,REL,1, "release-pmc pmc=%p ri=%d mode=%d", pm, ri, 2786 mode); 2787 2788 /* 2789 * First, we take the PMC off hardware. 2790 */ 2791 cpu = 0; 2792 if (PMC_IS_SYSTEM_MODE(mode)) { 2793 2794 /* 2795 * A system mode PMC runs on a specific CPU. Switch 2796 * to this CPU and turn hardware off. 2797 */ 2798 pmc_save_cpu_binding(&pb); 2799 2800 cpu = PMC_TO_CPU(pm); 2801 2802 pmc_select_cpu(cpu); 2803 2804 /* switch off non-stalled CPUs */ 2805 pm->pm_pcpu_state[cpu].pps_cpustate = 0; 2806 if (pm->pm_state == PMC_STATE_RUNNING && 2807 pm->pm_pcpu_state[cpu].pps_stalled == 0) { 2808 2809 phw = pmc_pcpu[cpu]->pc_hwpmcs[ri]; 2810 2811 KASSERT(phw->phw_pmc == pm, 2812 ("[pmc, %d] pmc ptr ri(%d) hw(%p) pm(%p)", 2813 __LINE__, ri, phw->phw_pmc, pm)); 2814 PMCDBG2(PMC,REL,2, "stopping cpu=%d ri=%d", cpu, ri); 2815 2816 critical_enter(); 2817 pcd->pcd_stop_pmc(cpu, adjri); 2818 critical_exit(); 2819 } 2820 2821 PMCDBG2(PMC,REL,2, "decfg cpu=%d ri=%d", cpu, ri); 2822 2823 critical_enter(); 2824 pcd->pcd_config_pmc(cpu, adjri, NULL); 2825 critical_exit(); 2826 2827 /* adjust the global and process count of SS mode PMCs */ 2828 if (mode == PMC_MODE_SS && pm->pm_state == PMC_STATE_RUNNING) { 2829 po = pm->pm_owner; 2830 po->po_sscount--; 2831 if (po->po_sscount == 0) { 2832 atomic_subtract_rel_int(&pmc_ss_count, 1); 2833 CK_LIST_REMOVE(po, po_ssnext); 2834 epoch_wait_preempt(global_epoch_preempt); 2835 } 2836 } 2837 2838 pm->pm_state = PMC_STATE_DELETED; 2839 2840 pmc_restore_cpu_binding(&pb); 2841 2842 /* 2843 * We could have references to this PMC structure in 2844 * the per-cpu sample queues. Wait for the queue to 2845 * drain. 2846 */ 2847 pmc_wait_for_pmc_idle(pm); 2848 2849 } else if (PMC_IS_VIRTUAL_MODE(mode)) { 2850 2851 /* 2852 * A virtual PMC could be running on multiple CPUs at 2853 * a given instant. 2854 * 2855 * By marking its state as DELETED, we ensure that 2856 * this PMC is never further scheduled on hardware. 2857 * 2858 * Then we wait till all CPUs are done with this PMC. 2859 */ 2860 pm->pm_state = PMC_STATE_DELETED; 2861 2862 2863 /* Wait for the PMCs runcount to come to zero. */ 2864 pmc_wait_for_pmc_idle(pm); 2865 2866 /* 2867 * At this point the PMC is off all CPUs and cannot be 2868 * freshly scheduled onto a CPU. It is now safe to 2869 * unlink all targets from this PMC. If a 2870 * process-record's refcount falls to zero, we remove 2871 * it from the hash table. The module-wide SX lock 2872 * protects us from races. 2873 */ 2874 LIST_FOREACH_SAFE(ptgt, &pm->pm_targets, pt_next, tmp) { 2875 pp = ptgt->pt_process; 2876 pmc_unlink_target_process(pm, pp); /* frees 'ptgt' */ 2877 2878 PMCDBG1(PMC,REL,3, "pp->refcnt=%d", pp->pp_refcnt); 2879 2880 /* 2881 * If the target process record shows that no 2882 * PMCs are attached to it, reclaim its space. 2883 */ 2884 2885 if (pp->pp_refcnt == 0) { 2886 pmc_remove_process_descriptor(pp); 2887 pmc_destroy_process_descriptor(pp); 2888 } 2889 } 2890 2891 cpu = curthread->td_oncpu; /* setup cpu for pmd_release() */ 2892 2893 } 2894 2895 /* 2896 * Release any MD resources 2897 */ 2898 (void) pcd->pcd_release_pmc(cpu, adjri, pm); 2899 2900 /* 2901 * Update row disposition 2902 */ 2903 2904 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) 2905 PMC_UNMARK_ROW_STANDALONE(ri); 2906 else 2907 PMC_UNMARK_ROW_THREAD(ri); 2908 2909 /* unlink from the owner's list */ 2910 if (pm->pm_owner) { 2911 LIST_REMOVE(pm, pm_next); 2912 pm->pm_owner = NULL; 2913 } 2914 } 2915 2916 /* 2917 * Register an owner and a pmc. 2918 */ 2919 2920 static int 2921 pmc_register_owner(struct proc *p, struct pmc *pmc) 2922 { 2923 struct pmc_owner *po; 2924 2925 sx_assert(&pmc_sx, SX_XLOCKED); 2926 2927 if ((po = pmc_find_owner_descriptor(p)) == NULL) 2928 if ((po = pmc_allocate_owner_descriptor(p)) == NULL) 2929 return ENOMEM; 2930 2931 KASSERT(pmc->pm_owner == NULL, 2932 ("[pmc,%d] attempting to own an initialized PMC", __LINE__)); 2933 pmc->pm_owner = po; 2934 2935 LIST_INSERT_HEAD(&po->po_pmcs, pmc, pm_next); 2936 2937 PROC_LOCK(p); 2938 p->p_flag |= P_HWPMC; 2939 PROC_UNLOCK(p); 2940 2941 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 2942 pmclog_process_pmcallocate(pmc); 2943 2944 PMCDBG2(PMC,REG,1, "register-owner pmc-owner=%p pmc=%p", 2945 po, pmc); 2946 2947 return 0; 2948 } 2949 2950 /* 2951 * Return the current row disposition: 2952 * == 0 => FREE 2953 * > 0 => PROCESS MODE 2954 * < 0 => SYSTEM MODE 2955 */ 2956 2957 int 2958 pmc_getrowdisp(int ri) 2959 { 2960 return pmc_pmcdisp[ri]; 2961 } 2962 2963 /* 2964 * Check if a PMC at row index 'ri' can be allocated to the current 2965 * process. 2966 * 2967 * Allocation can fail if: 2968 * - the current process is already being profiled by a PMC at index 'ri', 2969 * attached to it via OP_PMCATTACH. 2970 * - the current process has already allocated a PMC at index 'ri' 2971 * via OP_ALLOCATE. 2972 */ 2973 2974 static int 2975 pmc_can_allocate_rowindex(struct proc *p, unsigned int ri, int cpu) 2976 { 2977 enum pmc_mode mode; 2978 struct pmc *pm; 2979 struct pmc_owner *po; 2980 struct pmc_process *pp; 2981 2982 PMCDBG5(PMC,ALR,1, "can-allocate-rowindex proc=%p (%d, %s) ri=%d " 2983 "cpu=%d", p, p->p_pid, p->p_comm, ri, cpu); 2984 2985 /* 2986 * We shouldn't have already allocated a process-mode PMC at 2987 * row index 'ri'. 2988 * 2989 * We shouldn't have allocated a system-wide PMC on the same 2990 * CPU and same RI. 2991 */ 2992 if ((po = pmc_find_owner_descriptor(p)) != NULL) 2993 LIST_FOREACH(pm, &po->po_pmcs, pm_next) { 2994 if (PMC_TO_ROWINDEX(pm) == ri) { 2995 mode = PMC_TO_MODE(pm); 2996 if (PMC_IS_VIRTUAL_MODE(mode)) 2997 return EEXIST; 2998 if (PMC_IS_SYSTEM_MODE(mode) && 2999 (int) PMC_TO_CPU(pm) == cpu) 3000 return EEXIST; 3001 } 3002 } 3003 3004 /* 3005 * We also shouldn't be the target of any PMC at this index 3006 * since otherwise a PMC_ATTACH to ourselves will fail. 3007 */ 3008 if ((pp = pmc_find_process_descriptor(p, 0)) != NULL) 3009 if (pp->pp_pmcs[ri].pp_pmc) 3010 return EEXIST; 3011 3012 PMCDBG4(PMC,ALR,2, "can-allocate-rowindex proc=%p (%d, %s) ri=%d ok", 3013 p, p->p_pid, p->p_comm, ri); 3014 3015 return 0; 3016 } 3017 3018 /* 3019 * Check if a given PMC at row index 'ri' can be currently used in 3020 * mode 'mode'. 3021 */ 3022 3023 static int 3024 pmc_can_allocate_row(int ri, enum pmc_mode mode) 3025 { 3026 enum pmc_disp disp; 3027 3028 sx_assert(&pmc_sx, SX_XLOCKED); 3029 3030 PMCDBG2(PMC,ALR,1, "can-allocate-row ri=%d mode=%d", ri, mode); 3031 3032 if (PMC_IS_SYSTEM_MODE(mode)) 3033 disp = PMC_DISP_STANDALONE; 3034 else 3035 disp = PMC_DISP_THREAD; 3036 3037 /* 3038 * check disposition for PMC row 'ri': 3039 * 3040 * Expected disposition Row-disposition Result 3041 * 3042 * STANDALONE STANDALONE or FREE proceed 3043 * STANDALONE THREAD fail 3044 * THREAD THREAD or FREE proceed 3045 * THREAD STANDALONE fail 3046 */ 3047 3048 if (!PMC_ROW_DISP_IS_FREE(ri) && 3049 !(disp == PMC_DISP_THREAD && PMC_ROW_DISP_IS_THREAD(ri)) && 3050 !(disp == PMC_DISP_STANDALONE && PMC_ROW_DISP_IS_STANDALONE(ri))) 3051 return EBUSY; 3052 3053 /* 3054 * All OK 3055 */ 3056 3057 PMCDBG2(PMC,ALR,2, "can-allocate-row ri=%d mode=%d ok", ri, mode); 3058 3059 return 0; 3060 3061 } 3062 3063 /* 3064 * Find a PMC descriptor with user handle 'pmcid' for thread 'td'. 3065 */ 3066 3067 static struct pmc * 3068 pmc_find_pmc_descriptor_in_process(struct pmc_owner *po, pmc_id_t pmcid) 3069 { 3070 struct pmc *pm; 3071 3072 KASSERT(PMC_ID_TO_ROWINDEX(pmcid) < md->pmd_npmc, 3073 ("[pmc,%d] Illegal pmc index %d (max %d)", __LINE__, 3074 PMC_ID_TO_ROWINDEX(pmcid), md->pmd_npmc)); 3075 3076 LIST_FOREACH(pm, &po->po_pmcs, pm_next) 3077 if (pm->pm_id == pmcid) 3078 return pm; 3079 3080 return NULL; 3081 } 3082 3083 static int 3084 pmc_find_pmc(pmc_id_t pmcid, struct pmc **pmc) 3085 { 3086 3087 struct pmc *pm, *opm; 3088 struct pmc_owner *po; 3089 struct pmc_process *pp; 3090 3091 PMCDBG1(PMC,FND,1, "find-pmc id=%d", pmcid); 3092 if (PMC_ID_TO_ROWINDEX(pmcid) >= md->pmd_npmc) 3093 return (EINVAL); 3094 3095 if ((po = pmc_find_owner_descriptor(curthread->td_proc)) == NULL) { 3096 /* 3097 * In case of PMC_F_DESCENDANTS child processes we will not find 3098 * the current process in the owners hash list. Find the owner 3099 * process first and from there lookup the po. 3100 */ 3101 if ((pp = pmc_find_process_descriptor(curthread->td_proc, 3102 PMC_FLAG_NONE)) == NULL) { 3103 return ESRCH; 3104 } else { 3105 opm = pp->pp_pmcs[PMC_ID_TO_ROWINDEX(pmcid)].pp_pmc; 3106 if (opm == NULL) 3107 return ESRCH; 3108 if ((opm->pm_flags & (PMC_F_ATTACHED_TO_OWNER| 3109 PMC_F_DESCENDANTS)) != (PMC_F_ATTACHED_TO_OWNER| 3110 PMC_F_DESCENDANTS)) 3111 return ESRCH; 3112 po = opm->pm_owner; 3113 } 3114 } 3115 3116 if ((pm = pmc_find_pmc_descriptor_in_process(po, pmcid)) == NULL) 3117 return EINVAL; 3118 3119 PMCDBG2(PMC,FND,2, "find-pmc id=%d -> pmc=%p", pmcid, pm); 3120 3121 *pmc = pm; 3122 return 0; 3123 } 3124 3125 /* 3126 * Start a PMC. 3127 */ 3128 3129 static int 3130 pmc_start(struct pmc *pm) 3131 { 3132 enum pmc_mode mode; 3133 struct pmc_owner *po; 3134 struct pmc_binding pb; 3135 struct pmc_classdep *pcd; 3136 int adjri, error, cpu, ri; 3137 3138 KASSERT(pm != NULL, 3139 ("[pmc,%d] null pm", __LINE__)); 3140 3141 mode = PMC_TO_MODE(pm); 3142 ri = PMC_TO_ROWINDEX(pm); 3143 pcd = pmc_ri_to_classdep(md, ri, &adjri); 3144 3145 error = 0; 3146 3147 PMCDBG3(PMC,OPS,1, "start pmc=%p mode=%d ri=%d", pm, mode, ri); 3148 3149 po = pm->pm_owner; 3150 3151 /* 3152 * Disallow PMCSTART if a logfile is required but has not been 3153 * configured yet. 3154 */ 3155 if ((pm->pm_flags & PMC_F_NEEDS_LOGFILE) && 3156 (po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) 3157 return (EDOOFUS); /* programming error */ 3158 3159 /* 3160 * If this is a sampling mode PMC, log mapping information for 3161 * the kernel modules that are currently loaded. 3162 */ 3163 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 3164 pmc_log_kernel_mappings(pm); 3165 3166 if (PMC_IS_VIRTUAL_MODE(mode)) { 3167 3168 /* 3169 * If a PMCATTACH has never been done on this PMC, 3170 * attach it to its owner process. 3171 */ 3172 3173 if (LIST_EMPTY(&pm->pm_targets)) 3174 error = (pm->pm_flags & PMC_F_ATTACH_DONE) ? ESRCH : 3175 pmc_attach_process(po->po_owner, pm); 3176 3177 /* 3178 * If the PMC is attached to its owner, then force a context 3179 * switch to ensure that the MD state gets set correctly. 3180 */ 3181 3182 if (error == 0) { 3183 pm->pm_state = PMC_STATE_RUNNING; 3184 if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) 3185 pmc_force_context_switch(); 3186 } 3187 3188 return (error); 3189 } 3190 3191 3192 /* 3193 * A system-wide PMC. 3194 * 3195 * Add the owner to the global list if this is a system-wide 3196 * sampling PMC. 3197 */ 3198 3199 if (mode == PMC_MODE_SS) { 3200 /* 3201 * Log mapping information for all existing processes in the 3202 * system. Subsequent mappings are logged as they happen; 3203 * see pmc_process_mmap(). 3204 */ 3205 if (po->po_logprocmaps == 0) { 3206 pmc_log_all_process_mappings(po); 3207 po->po_logprocmaps = 1; 3208 } 3209 po->po_sscount++; 3210 if (po->po_sscount == 1) { 3211 atomic_add_rel_int(&pmc_ss_count, 1); 3212 CK_LIST_INSERT_HEAD(&pmc_ss_owners, po, po_ssnext); 3213 PMCDBG1(PMC,OPS,1, "po=%p in global list", po); 3214 } 3215 } 3216 3217 /* 3218 * Move to the CPU associated with this 3219 * PMC, and start the hardware. 3220 */ 3221 3222 pmc_save_cpu_binding(&pb); 3223 3224 cpu = PMC_TO_CPU(pm); 3225 3226 if (!pmc_cpu_is_active(cpu)) 3227 return (ENXIO); 3228 3229 pmc_select_cpu(cpu); 3230 3231 /* 3232 * global PMCs are configured at allocation time 3233 * so write out the initial value and start the PMC. 3234 */ 3235 3236 pm->pm_state = PMC_STATE_RUNNING; 3237 3238 critical_enter(); 3239 if ((error = pcd->pcd_write_pmc(cpu, adjri, 3240 PMC_IS_SAMPLING_MODE(mode) ? 3241 pm->pm_sc.pm_reloadcount : 3242 pm->pm_sc.pm_initial)) == 0) { 3243 /* If a sampling mode PMC, reset stalled state. */ 3244 if (PMC_IS_SAMPLING_MODE(mode)) 3245 pm->pm_pcpu_state[cpu].pps_stalled = 0; 3246 3247 /* Indicate that we desire this to run. Start it. */ 3248 pm->pm_pcpu_state[cpu].pps_cpustate = 1; 3249 error = pcd->pcd_start_pmc(cpu, adjri); 3250 } 3251 critical_exit(); 3252 3253 pmc_restore_cpu_binding(&pb); 3254 3255 return (error); 3256 } 3257 3258 /* 3259 * Stop a PMC. 3260 */ 3261 3262 static int 3263 pmc_stop(struct pmc *pm) 3264 { 3265 struct pmc_owner *po; 3266 struct pmc_binding pb; 3267 struct pmc_classdep *pcd; 3268 int adjri, cpu, error, ri; 3269 3270 KASSERT(pm != NULL, ("[pmc,%d] null pmc", __LINE__)); 3271 3272 PMCDBG3(PMC,OPS,1, "stop pmc=%p mode=%d ri=%d", pm, 3273 PMC_TO_MODE(pm), PMC_TO_ROWINDEX(pm)); 3274 3275 pm->pm_state = PMC_STATE_STOPPED; 3276 3277 /* 3278 * If the PMC is a virtual mode one, changing the state to 3279 * non-RUNNING is enough to ensure that the PMC never gets 3280 * scheduled. 3281 * 3282 * If this PMC is current running on a CPU, then it will 3283 * handled correctly at the time its target process is context 3284 * switched out. 3285 */ 3286 3287 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) 3288 return 0; 3289 3290 /* 3291 * A system-mode PMC. Move to the CPU associated with 3292 * this PMC, and stop the hardware. We update the 3293 * 'initial count' so that a subsequent PMCSTART will 3294 * resume counting from the current hardware count. 3295 */ 3296 3297 pmc_save_cpu_binding(&pb); 3298 3299 cpu = PMC_TO_CPU(pm); 3300 3301 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 3302 ("[pmc,%d] illegal cpu=%d", __LINE__, cpu)); 3303 3304 if (!pmc_cpu_is_active(cpu)) 3305 return ENXIO; 3306 3307 pmc_select_cpu(cpu); 3308 3309 ri = PMC_TO_ROWINDEX(pm); 3310 pcd = pmc_ri_to_classdep(md, ri, &adjri); 3311 3312 pm->pm_pcpu_state[cpu].pps_cpustate = 0; 3313 critical_enter(); 3314 if ((error = pcd->pcd_stop_pmc(cpu, adjri)) == 0) 3315 error = pcd->pcd_read_pmc(cpu, adjri, &pm->pm_sc.pm_initial); 3316 critical_exit(); 3317 3318 pmc_restore_cpu_binding(&pb); 3319 3320 po = pm->pm_owner; 3321 3322 /* remove this owner from the global list of SS PMC owners */ 3323 if (PMC_TO_MODE(pm) == PMC_MODE_SS) { 3324 po->po_sscount--; 3325 if (po->po_sscount == 0) { 3326 atomic_subtract_rel_int(&pmc_ss_count, 1); 3327 CK_LIST_REMOVE(po, po_ssnext); 3328 epoch_wait_preempt(global_epoch_preempt); 3329 PMCDBG1(PMC,OPS,2,"po=%p removed from global list", po); 3330 } 3331 } 3332 3333 return (error); 3334 } 3335 3336 static struct pmc_classdep * 3337 pmc_class_to_classdep(enum pmc_class class) 3338 { 3339 int n; 3340 3341 for (n = 0; n < md->pmd_nclass; n++) 3342 if (md->pmd_classdep[n].pcd_class == class) 3343 return (&md->pmd_classdep[n]); 3344 return (NULL); 3345 } 3346 3347 #if defined(HWPMC_DEBUG) && defined(KTR) 3348 static const char *pmc_op_to_name[] = { 3349 #undef __PMC_OP 3350 #define __PMC_OP(N, D) #N , 3351 __PMC_OPS() 3352 NULL 3353 }; 3354 #endif 3355 3356 /* 3357 * The syscall interface 3358 */ 3359 3360 #define PMC_GET_SX_XLOCK(...) do { \ 3361 sx_xlock(&pmc_sx); \ 3362 if (pmc_hook == NULL) { \ 3363 sx_xunlock(&pmc_sx); \ 3364 return __VA_ARGS__; \ 3365 } \ 3366 } while (0) 3367 3368 #define PMC_DOWNGRADE_SX() do { \ 3369 sx_downgrade(&pmc_sx); \ 3370 is_sx_downgraded = 1; \ 3371 } while (0) 3372 3373 static int 3374 pmc_syscall_handler(struct thread *td, void *syscall_args) 3375 { 3376 int error, is_sx_downgraded, op; 3377 struct pmc_syscall_args *c; 3378 void *pmclog_proc_handle; 3379 void *arg; 3380 3381 c = (struct pmc_syscall_args *)syscall_args; 3382 op = c->pmop_code; 3383 arg = c->pmop_data; 3384 /* PMC isn't set up yet */ 3385 if (pmc_hook == NULL) 3386 return (EINVAL); 3387 if (op == PMC_OP_CONFIGURELOG) { 3388 /* 3389 * We cannot create the logging process inside 3390 * pmclog_configure_log() because there is a LOR 3391 * between pmc_sx and process structure locks. 3392 * Instead, pre-create the process and ignite the loop 3393 * if everything is fine, otherwise direct the process 3394 * to exit. 3395 */ 3396 error = pmclog_proc_create(td, &pmclog_proc_handle); 3397 if (error != 0) 3398 goto done_syscall; 3399 } 3400 3401 PMC_GET_SX_XLOCK(ENOSYS); 3402 is_sx_downgraded = 0; 3403 PMCDBG3(MOD,PMS,1, "syscall op=%d \"%s\" arg=%p", op, 3404 pmc_op_to_name[op], arg); 3405 3406 error = 0; 3407 counter_u64_add(pmc_stats.pm_syscalls, 1); 3408 3409 switch (op) { 3410 3411 3412 /* 3413 * Configure a log file. 3414 * 3415 * XXX This OP will be reworked. 3416 */ 3417 3418 case PMC_OP_CONFIGURELOG: 3419 { 3420 struct proc *p; 3421 struct pmc *pm; 3422 struct pmc_owner *po; 3423 struct pmc_op_configurelog cl; 3424 3425 if ((error = copyin(arg, &cl, sizeof(cl))) != 0) { 3426 pmclog_proc_ignite(pmclog_proc_handle, NULL); 3427 break; 3428 } 3429 3430 /* mark this process as owning a log file */ 3431 p = td->td_proc; 3432 if ((po = pmc_find_owner_descriptor(p)) == NULL) 3433 if ((po = pmc_allocate_owner_descriptor(p)) == NULL) { 3434 pmclog_proc_ignite(pmclog_proc_handle, NULL); 3435 error = ENOMEM; 3436 break; 3437 } 3438 3439 /* 3440 * If a valid fd was passed in, try to configure that, 3441 * otherwise if 'fd' was less than zero and there was 3442 * a log file configured, flush its buffers and 3443 * de-configure it. 3444 */ 3445 if (cl.pm_logfd >= 0) { 3446 error = pmclog_configure_log(md, po, cl.pm_logfd); 3447 pmclog_proc_ignite(pmclog_proc_handle, error == 0 ? 3448 po : NULL); 3449 } else if (po->po_flags & PMC_PO_OWNS_LOGFILE) { 3450 pmclog_proc_ignite(pmclog_proc_handle, NULL); 3451 error = pmclog_close(po); 3452 if (error == 0) { 3453 LIST_FOREACH(pm, &po->po_pmcs, pm_next) 3454 if (pm->pm_flags & PMC_F_NEEDS_LOGFILE && 3455 pm->pm_state == PMC_STATE_RUNNING) 3456 pmc_stop(pm); 3457 error = pmclog_deconfigure_log(po); 3458 } 3459 } else { 3460 pmclog_proc_ignite(pmclog_proc_handle, NULL); 3461 error = EINVAL; 3462 } 3463 } 3464 break; 3465 3466 /* 3467 * Flush a log file. 3468 */ 3469 3470 case PMC_OP_FLUSHLOG: 3471 { 3472 struct pmc_owner *po; 3473 3474 sx_assert(&pmc_sx, SX_XLOCKED); 3475 3476 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 3477 error = EINVAL; 3478 break; 3479 } 3480 3481 error = pmclog_flush(po, 0); 3482 } 3483 break; 3484 3485 /* 3486 * Close a log file. 3487 */ 3488 3489 case PMC_OP_CLOSELOG: 3490 { 3491 struct pmc_owner *po; 3492 3493 sx_assert(&pmc_sx, SX_XLOCKED); 3494 3495 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 3496 error = EINVAL; 3497 break; 3498 } 3499 3500 error = pmclog_close(po); 3501 } 3502 break; 3503 3504 /* 3505 * Retrieve hardware configuration. 3506 */ 3507 3508 case PMC_OP_GETCPUINFO: /* CPU information */ 3509 { 3510 struct pmc_op_getcpuinfo gci; 3511 struct pmc_classinfo *pci; 3512 struct pmc_classdep *pcd; 3513 int cl; 3514 3515 gci.pm_cputype = md->pmd_cputype; 3516 gci.pm_ncpu = pmc_cpu_max(); 3517 gci.pm_npmc = md->pmd_npmc; 3518 gci.pm_nclass = md->pmd_nclass; 3519 pci = gci.pm_classes; 3520 pcd = md->pmd_classdep; 3521 for (cl = 0; cl < md->pmd_nclass; cl++, pci++, pcd++) { 3522 pci->pm_caps = pcd->pcd_caps; 3523 pci->pm_class = pcd->pcd_class; 3524 pci->pm_width = pcd->pcd_width; 3525 pci->pm_num = pcd->pcd_num; 3526 } 3527 error = copyout(&gci, arg, sizeof(gci)); 3528 } 3529 break; 3530 3531 /* 3532 * Retrieve soft events list. 3533 */ 3534 case PMC_OP_GETDYNEVENTINFO: 3535 { 3536 enum pmc_class cl; 3537 enum pmc_event ev; 3538 struct pmc_op_getdyneventinfo *gei; 3539 struct pmc_dyn_event_descr dev; 3540 struct pmc_soft *ps; 3541 uint32_t nevent; 3542 3543 sx_assert(&pmc_sx, SX_LOCKED); 3544 3545 gei = (struct pmc_op_getdyneventinfo *) arg; 3546 3547 if ((error = copyin(&gei->pm_class, &cl, sizeof(cl))) != 0) 3548 break; 3549 3550 /* Only SOFT class is dynamic. */ 3551 if (cl != PMC_CLASS_SOFT) { 3552 error = EINVAL; 3553 break; 3554 } 3555 3556 nevent = 0; 3557 for (ev = PMC_EV_SOFT_FIRST; (int)ev <= PMC_EV_SOFT_LAST; ev++) { 3558 ps = pmc_soft_ev_acquire(ev); 3559 if (ps == NULL) 3560 continue; 3561 bcopy(&ps->ps_ev, &dev, sizeof(dev)); 3562 pmc_soft_ev_release(ps); 3563 3564 error = copyout(&dev, 3565 &gei->pm_events[nevent], 3566 sizeof(struct pmc_dyn_event_descr)); 3567 if (error != 0) 3568 break; 3569 nevent++; 3570 } 3571 if (error != 0) 3572 break; 3573 3574 error = copyout(&nevent, &gei->pm_nevent, 3575 sizeof(nevent)); 3576 } 3577 break; 3578 3579 /* 3580 * Get module statistics 3581 */ 3582 3583 case PMC_OP_GETDRIVERSTATS: 3584 { 3585 struct pmc_op_getdriverstats gms; 3586 #define CFETCH(a, b, field) a.field = counter_u64_fetch(b.field) 3587 CFETCH(gms, pmc_stats, pm_intr_ignored); 3588 CFETCH(gms, pmc_stats, pm_intr_processed); 3589 CFETCH(gms, pmc_stats, pm_intr_bufferfull); 3590 CFETCH(gms, pmc_stats, pm_syscalls); 3591 CFETCH(gms, pmc_stats, pm_syscall_errors); 3592 CFETCH(gms, pmc_stats, pm_buffer_requests); 3593 CFETCH(gms, pmc_stats, pm_buffer_requests_failed); 3594 CFETCH(gms, pmc_stats, pm_log_sweeps); 3595 #undef CFETCH 3596 error = copyout(&gms, arg, sizeof(gms)); 3597 } 3598 break; 3599 3600 3601 /* 3602 * Retrieve module version number 3603 */ 3604 3605 case PMC_OP_GETMODULEVERSION: 3606 { 3607 uint32_t cv, modv; 3608 3609 /* retrieve the client's idea of the ABI version */ 3610 if ((error = copyin(arg, &cv, sizeof(uint32_t))) != 0) 3611 break; 3612 /* don't service clients newer than our driver */ 3613 modv = PMC_VERSION; 3614 if ((cv & 0xFFFF0000) > (modv & 0xFFFF0000)) { 3615 error = EPROGMISMATCH; 3616 break; 3617 } 3618 error = copyout(&modv, arg, sizeof(int)); 3619 } 3620 break; 3621 3622 3623 /* 3624 * Retrieve the state of all the PMCs on a given 3625 * CPU. 3626 */ 3627 3628 case PMC_OP_GETPMCINFO: 3629 { 3630 int ari; 3631 struct pmc *pm; 3632 size_t pmcinfo_size; 3633 uint32_t cpu, n, npmc; 3634 struct pmc_owner *po; 3635 struct pmc_binding pb; 3636 struct pmc_classdep *pcd; 3637 struct pmc_info *p, *pmcinfo; 3638 struct pmc_op_getpmcinfo *gpi; 3639 3640 PMC_DOWNGRADE_SX(); 3641 3642 gpi = (struct pmc_op_getpmcinfo *) arg; 3643 3644 if ((error = copyin(&gpi->pm_cpu, &cpu, sizeof(cpu))) != 0) 3645 break; 3646 3647 if (cpu >= pmc_cpu_max()) { 3648 error = EINVAL; 3649 break; 3650 } 3651 3652 if (!pmc_cpu_is_active(cpu)) { 3653 error = ENXIO; 3654 break; 3655 } 3656 3657 /* switch to CPU 'cpu' */ 3658 pmc_save_cpu_binding(&pb); 3659 pmc_select_cpu(cpu); 3660 3661 npmc = md->pmd_npmc; 3662 3663 pmcinfo_size = npmc * sizeof(struct pmc_info); 3664 pmcinfo = malloc(pmcinfo_size, M_PMC, M_WAITOK); 3665 3666 p = pmcinfo; 3667 3668 for (n = 0; n < md->pmd_npmc; n++, p++) { 3669 3670 pcd = pmc_ri_to_classdep(md, n, &ari); 3671 3672 KASSERT(pcd != NULL, 3673 ("[pmc,%d] null pcd ri=%d", __LINE__, n)); 3674 3675 if ((error = pcd->pcd_describe(cpu, ari, p, &pm)) != 0) 3676 break; 3677 3678 if (PMC_ROW_DISP_IS_STANDALONE(n)) 3679 p->pm_rowdisp = PMC_DISP_STANDALONE; 3680 else if (PMC_ROW_DISP_IS_THREAD(n)) 3681 p->pm_rowdisp = PMC_DISP_THREAD; 3682 else 3683 p->pm_rowdisp = PMC_DISP_FREE; 3684 3685 p->pm_ownerpid = -1; 3686 3687 if (pm == NULL) /* no PMC associated */ 3688 continue; 3689 3690 po = pm->pm_owner; 3691 3692 KASSERT(po->po_owner != NULL, 3693 ("[pmc,%d] pmc_owner had a null proc pointer", 3694 __LINE__)); 3695 3696 p->pm_ownerpid = po->po_owner->p_pid; 3697 p->pm_mode = PMC_TO_MODE(pm); 3698 p->pm_event = pm->pm_event; 3699 p->pm_flags = pm->pm_flags; 3700 3701 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 3702 p->pm_reloadcount = 3703 pm->pm_sc.pm_reloadcount; 3704 } 3705 3706 pmc_restore_cpu_binding(&pb); 3707 3708 /* now copy out the PMC info collected */ 3709 if (error == 0) 3710 error = copyout(pmcinfo, &gpi->pm_pmcs, pmcinfo_size); 3711 3712 free(pmcinfo, M_PMC); 3713 } 3714 break; 3715 3716 3717 /* 3718 * Set the administrative state of a PMC. I.e. whether 3719 * the PMC is to be used or not. 3720 */ 3721 3722 case PMC_OP_PMCADMIN: 3723 { 3724 int cpu, ri; 3725 enum pmc_state request; 3726 struct pmc_cpu *pc; 3727 struct pmc_hw *phw; 3728 struct pmc_op_pmcadmin pma; 3729 struct pmc_binding pb; 3730 3731 sx_assert(&pmc_sx, SX_XLOCKED); 3732 3733 KASSERT(td == curthread, 3734 ("[pmc,%d] td != curthread", __LINE__)); 3735 3736 error = priv_check(td, PRIV_PMC_MANAGE); 3737 if (error) 3738 break; 3739 3740 if ((error = copyin(arg, &pma, sizeof(pma))) != 0) 3741 break; 3742 3743 cpu = pma.pm_cpu; 3744 3745 if (cpu < 0 || cpu >= (int) pmc_cpu_max()) { 3746 error = EINVAL; 3747 break; 3748 } 3749 3750 if (!pmc_cpu_is_active(cpu)) { 3751 error = ENXIO; 3752 break; 3753 } 3754 3755 request = pma.pm_state; 3756 3757 if (request != PMC_STATE_DISABLED && 3758 request != PMC_STATE_FREE) { 3759 error = EINVAL; 3760 break; 3761 } 3762 3763 ri = pma.pm_pmc; /* pmc id == row index */ 3764 if (ri < 0 || ri >= (int) md->pmd_npmc) { 3765 error = EINVAL; 3766 break; 3767 } 3768 3769 /* 3770 * We can't disable a PMC with a row-index allocated 3771 * for process virtual PMCs. 3772 */ 3773 3774 if (PMC_ROW_DISP_IS_THREAD(ri) && 3775 request == PMC_STATE_DISABLED) { 3776 error = EBUSY; 3777 break; 3778 } 3779 3780 /* 3781 * otherwise, this PMC on this CPU is either free or 3782 * in system-wide mode. 3783 */ 3784 3785 pmc_save_cpu_binding(&pb); 3786 pmc_select_cpu(cpu); 3787 3788 pc = pmc_pcpu[cpu]; 3789 phw = pc->pc_hwpmcs[ri]; 3790 3791 /* 3792 * XXX do we need some kind of 'forced' disable? 3793 */ 3794 3795 if (phw->phw_pmc == NULL) { 3796 if (request == PMC_STATE_DISABLED && 3797 (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED)) { 3798 phw->phw_state &= ~PMC_PHW_FLAG_IS_ENABLED; 3799 PMC_MARK_ROW_STANDALONE(ri); 3800 } else if (request == PMC_STATE_FREE && 3801 (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0) { 3802 phw->phw_state |= PMC_PHW_FLAG_IS_ENABLED; 3803 PMC_UNMARK_ROW_STANDALONE(ri); 3804 } 3805 /* other cases are a no-op */ 3806 } else 3807 error = EBUSY; 3808 3809 pmc_restore_cpu_binding(&pb); 3810 } 3811 break; 3812 3813 3814 /* 3815 * Allocate a PMC. 3816 */ 3817 3818 case PMC_OP_PMCALLOCATE: 3819 { 3820 int adjri, n; 3821 u_int cpu; 3822 uint32_t caps; 3823 struct pmc *pmc; 3824 enum pmc_mode mode; 3825 struct pmc_hw *phw; 3826 struct pmc_binding pb; 3827 struct pmc_classdep *pcd; 3828 struct pmc_op_pmcallocate pa; 3829 3830 if ((error = copyin(arg, &pa, sizeof(pa))) != 0) 3831 break; 3832 3833 caps = pa.pm_caps; 3834 mode = pa.pm_mode; 3835 cpu = pa.pm_cpu; 3836 3837 if ((mode != PMC_MODE_SS && mode != PMC_MODE_SC && 3838 mode != PMC_MODE_TS && mode != PMC_MODE_TC) || 3839 (cpu != (u_int) PMC_CPU_ANY && cpu >= pmc_cpu_max())) { 3840 error = EINVAL; 3841 break; 3842 } 3843 3844 /* 3845 * Virtual PMCs should only ask for a default CPU. 3846 * System mode PMCs need to specify a non-default CPU. 3847 */ 3848 3849 if ((PMC_IS_VIRTUAL_MODE(mode) && cpu != (u_int) PMC_CPU_ANY) || 3850 (PMC_IS_SYSTEM_MODE(mode) && cpu == (u_int) PMC_CPU_ANY)) { 3851 error = EINVAL; 3852 break; 3853 } 3854 3855 /* 3856 * Check that an inactive CPU is not being asked for. 3857 */ 3858 3859 if (PMC_IS_SYSTEM_MODE(mode) && !pmc_cpu_is_active(cpu)) { 3860 error = ENXIO; 3861 break; 3862 } 3863 3864 /* 3865 * Refuse an allocation for a system-wide PMC if this 3866 * process has been jailed, or if this process lacks 3867 * super-user credentials and the sysctl tunable 3868 * 'security.bsd.unprivileged_syspmcs' is zero. 3869 */ 3870 3871 if (PMC_IS_SYSTEM_MODE(mode)) { 3872 if (jailed(curthread->td_ucred)) { 3873 error = EPERM; 3874 break; 3875 } 3876 if (!pmc_unprivileged_syspmcs) { 3877 error = priv_check(curthread, 3878 PRIV_PMC_SYSTEM); 3879 if (error) 3880 break; 3881 } 3882 } 3883 3884 /* 3885 * Look for valid values for 'pm_flags' 3886 */ 3887 3888 if ((pa.pm_flags & ~(PMC_F_DESCENDANTS | PMC_F_LOG_PROCCSW | 3889 PMC_F_LOG_PROCEXIT | PMC_F_CALLCHAIN | 3890 PMC_F_USERCALLCHAIN)) != 0) { 3891 error = EINVAL; 3892 break; 3893 } 3894 3895 /* PMC_F_USERCALLCHAIN is only valid with PMC_F_CALLCHAIN */ 3896 if ((pa.pm_flags & (PMC_F_CALLCHAIN | PMC_F_USERCALLCHAIN)) == 3897 PMC_F_USERCALLCHAIN) { 3898 error = EINVAL; 3899 break; 3900 } 3901 3902 /* PMC_F_USERCALLCHAIN is only valid for sampling mode */ 3903 if (pa.pm_flags & PMC_F_USERCALLCHAIN && 3904 mode != PMC_MODE_TS && mode != PMC_MODE_SS) { 3905 error = EINVAL; 3906 break; 3907 } 3908 3909 /* process logging options are not allowed for system PMCs */ 3910 if (PMC_IS_SYSTEM_MODE(mode) && (pa.pm_flags & 3911 (PMC_F_LOG_PROCCSW | PMC_F_LOG_PROCEXIT))) { 3912 error = EINVAL; 3913 break; 3914 } 3915 3916 /* 3917 * All sampling mode PMCs need to be able to interrupt the 3918 * CPU. 3919 */ 3920 if (PMC_IS_SAMPLING_MODE(mode)) 3921 caps |= PMC_CAP_INTERRUPT; 3922 3923 /* A valid class specifier should have been passed in. */ 3924 pcd = pmc_class_to_classdep(pa.pm_class); 3925 if (pcd == NULL) { 3926 error = EINVAL; 3927 break; 3928 } 3929 3930 /* The requested PMC capabilities should be feasible. */ 3931 if ((pcd->pcd_caps & caps) != caps) { 3932 error = EOPNOTSUPP; 3933 break; 3934 } 3935 3936 PMCDBG4(PMC,ALL,2, "event=%d caps=0x%x mode=%d cpu=%d", 3937 pa.pm_ev, caps, mode, cpu); 3938 3939 pmc = pmc_allocate_pmc_descriptor(); 3940 pmc->pm_id = PMC_ID_MAKE_ID(cpu,pa.pm_mode,pa.pm_class, 3941 PMC_ID_INVALID); 3942 pmc->pm_event = pa.pm_ev; 3943 pmc->pm_state = PMC_STATE_FREE; 3944 pmc->pm_caps = caps; 3945 pmc->pm_flags = pa.pm_flags; 3946 3947 /* XXX set lower bound on sampling for process counters */ 3948 if (PMC_IS_SAMPLING_MODE(mode)) { 3949 /* 3950 * Don't permit requested sample rate to be less than 1000 3951 */ 3952 if (pa.pm_count < 1000) 3953 log(LOG_WARNING, 3954 "pmcallocate: passed sample rate %ju - setting to 1000\n", 3955 (uintmax_t)pa.pm_count); 3956 pmc->pm_sc.pm_reloadcount = MAX(1000, pa.pm_count); 3957 } else 3958 pmc->pm_sc.pm_initial = pa.pm_count; 3959 3960 /* switch thread to CPU 'cpu' */ 3961 pmc_save_cpu_binding(&pb); 3962 3963 #define PMC_IS_SHAREABLE_PMC(cpu, n) \ 3964 (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_state & \ 3965 PMC_PHW_FLAG_IS_SHAREABLE) 3966 #define PMC_IS_UNALLOCATED(cpu, n) \ 3967 (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_pmc == NULL) 3968 3969 if (PMC_IS_SYSTEM_MODE(mode)) { 3970 pmc_select_cpu(cpu); 3971 for (n = pcd->pcd_ri; n < (int) md->pmd_npmc; n++) { 3972 pcd = pmc_ri_to_classdep(md, n, &adjri); 3973 if (pmc_can_allocate_row(n, mode) == 0 && 3974 pmc_can_allocate_rowindex( 3975 curthread->td_proc, n, cpu) == 0 && 3976 (PMC_IS_UNALLOCATED(cpu, n) || 3977 PMC_IS_SHAREABLE_PMC(cpu, n)) && 3978 pcd->pcd_allocate_pmc(cpu, adjri, pmc, 3979 &pa) == 0) 3980 break; 3981 } 3982 } else { 3983 /* Process virtual mode */ 3984 for (n = pcd->pcd_ri; n < (int) md->pmd_npmc; n++) { 3985 pcd = pmc_ri_to_classdep(md, n, &adjri); 3986 if (pmc_can_allocate_row(n, mode) == 0 && 3987 pmc_can_allocate_rowindex( 3988 curthread->td_proc, n, 3989 PMC_CPU_ANY) == 0 && 3990 pcd->pcd_allocate_pmc(curthread->td_oncpu, 3991 adjri, pmc, &pa) == 0) 3992 break; 3993 } 3994 } 3995 3996 #undef PMC_IS_UNALLOCATED 3997 #undef PMC_IS_SHAREABLE_PMC 3998 3999 pmc_restore_cpu_binding(&pb); 4000 4001 if (n == (int) md->pmd_npmc) { 4002 pmc_destroy_pmc_descriptor(pmc); 4003 pmc = NULL; 4004 error = EINVAL; 4005 break; 4006 } 4007 4008 /* Fill in the correct value in the ID field */ 4009 pmc->pm_id = PMC_ID_MAKE_ID(cpu,mode,pa.pm_class,n); 4010 4011 PMCDBG5(PMC,ALL,2, "ev=%d class=%d mode=%d n=%d -> pmcid=%x", 4012 pmc->pm_event, pa.pm_class, mode, n, pmc->pm_id); 4013 4014 /* Process mode PMCs with logging enabled need log files */ 4015 if (pmc->pm_flags & (PMC_F_LOG_PROCEXIT | PMC_F_LOG_PROCCSW)) 4016 pmc->pm_flags |= PMC_F_NEEDS_LOGFILE; 4017 4018 /* All system mode sampling PMCs require a log file */ 4019 if (PMC_IS_SAMPLING_MODE(mode) && PMC_IS_SYSTEM_MODE(mode)) 4020 pmc->pm_flags |= PMC_F_NEEDS_LOGFILE; 4021 4022 /* 4023 * Configure global pmc's immediately 4024 */ 4025 4026 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pmc))) { 4027 4028 pmc_save_cpu_binding(&pb); 4029 pmc_select_cpu(cpu); 4030 4031 phw = pmc_pcpu[cpu]->pc_hwpmcs[n]; 4032 pcd = pmc_ri_to_classdep(md, n, &adjri); 4033 4034 if ((phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0 || 4035 (error = pcd->pcd_config_pmc(cpu, adjri, pmc)) != 0) { 4036 (void) pcd->pcd_release_pmc(cpu, adjri, pmc); 4037 pmc_destroy_pmc_descriptor(pmc); 4038 pmc = NULL; 4039 pmc_restore_cpu_binding(&pb); 4040 error = EPERM; 4041 break; 4042 } 4043 4044 pmc_restore_cpu_binding(&pb); 4045 } 4046 4047 pmc->pm_state = PMC_STATE_ALLOCATED; 4048 pmc->pm_class = pa.pm_class; 4049 4050 /* 4051 * mark row disposition 4052 */ 4053 4054 if (PMC_IS_SYSTEM_MODE(mode)) 4055 PMC_MARK_ROW_STANDALONE(n); 4056 else 4057 PMC_MARK_ROW_THREAD(n); 4058 4059 /* 4060 * Register this PMC with the current thread as its owner. 4061 */ 4062 4063 if ((error = 4064 pmc_register_owner(curthread->td_proc, pmc)) != 0) { 4065 pmc_release_pmc_descriptor(pmc); 4066 pmc_destroy_pmc_descriptor(pmc); 4067 pmc = NULL; 4068 break; 4069 } 4070 4071 4072 /* 4073 * Return the allocated index. 4074 */ 4075 4076 pa.pm_pmcid = pmc->pm_id; 4077 4078 error = copyout(&pa, arg, sizeof(pa)); 4079 } 4080 break; 4081 4082 4083 /* 4084 * Attach a PMC to a process. 4085 */ 4086 4087 case PMC_OP_PMCATTACH: 4088 { 4089 struct pmc *pm; 4090 struct proc *p; 4091 struct pmc_op_pmcattach a; 4092 4093 sx_assert(&pmc_sx, SX_XLOCKED); 4094 4095 if ((error = copyin(arg, &a, sizeof(a))) != 0) 4096 break; 4097 4098 if (a.pm_pid < 0) { 4099 error = EINVAL; 4100 break; 4101 } else if (a.pm_pid == 0) 4102 a.pm_pid = td->td_proc->p_pid; 4103 4104 if ((error = pmc_find_pmc(a.pm_pmc, &pm)) != 0) 4105 break; 4106 4107 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) { 4108 error = EINVAL; 4109 break; 4110 } 4111 4112 /* PMCs may be (re)attached only when allocated or stopped */ 4113 if (pm->pm_state == PMC_STATE_RUNNING) { 4114 error = EBUSY; 4115 break; 4116 } else if (pm->pm_state != PMC_STATE_ALLOCATED && 4117 pm->pm_state != PMC_STATE_STOPPED) { 4118 error = EINVAL; 4119 break; 4120 } 4121 4122 /* lookup pid */ 4123 if ((p = pfind(a.pm_pid)) == NULL) { 4124 error = ESRCH; 4125 break; 4126 } 4127 4128 /* 4129 * Ignore processes that are working on exiting. 4130 */ 4131 if (p->p_flag & P_WEXIT) { 4132 error = ESRCH; 4133 PROC_UNLOCK(p); /* pfind() returns a locked process */ 4134 break; 4135 } 4136 4137 /* 4138 * we are allowed to attach a PMC to a process if 4139 * we can debug it. 4140 */ 4141 error = p_candebug(curthread, p); 4142 4143 PROC_UNLOCK(p); 4144 4145 if (error == 0) 4146 error = pmc_attach_process(p, pm); 4147 } 4148 break; 4149 4150 4151 /* 4152 * Detach an attached PMC from a process. 4153 */ 4154 4155 case PMC_OP_PMCDETACH: 4156 { 4157 struct pmc *pm; 4158 struct proc *p; 4159 struct pmc_op_pmcattach a; 4160 4161 if ((error = copyin(arg, &a, sizeof(a))) != 0) 4162 break; 4163 4164 if (a.pm_pid < 0) { 4165 error = EINVAL; 4166 break; 4167 } else if (a.pm_pid == 0) 4168 a.pm_pid = td->td_proc->p_pid; 4169 4170 if ((error = pmc_find_pmc(a.pm_pmc, &pm)) != 0) 4171 break; 4172 4173 if ((p = pfind(a.pm_pid)) == NULL) { 4174 error = ESRCH; 4175 break; 4176 } 4177 4178 /* 4179 * Treat processes that are in the process of exiting 4180 * as if they were not present. 4181 */ 4182 4183 if (p->p_flag & P_WEXIT) 4184 error = ESRCH; 4185 4186 PROC_UNLOCK(p); /* pfind() returns a locked process */ 4187 4188 if (error == 0) 4189 error = pmc_detach_process(p, pm); 4190 } 4191 break; 4192 4193 4194 /* 4195 * Retrieve the MSR number associated with the counter 4196 * 'pmc_id'. This allows processes to directly use RDPMC 4197 * instructions to read their PMCs, without the overhead of a 4198 * system call. 4199 */ 4200 4201 case PMC_OP_PMCGETMSR: 4202 { 4203 int adjri, ri; 4204 struct pmc *pm; 4205 struct pmc_target *pt; 4206 struct pmc_op_getmsr gm; 4207 struct pmc_classdep *pcd; 4208 4209 PMC_DOWNGRADE_SX(); 4210 4211 if ((error = copyin(arg, &gm, sizeof(gm))) != 0) 4212 break; 4213 4214 if ((error = pmc_find_pmc(gm.pm_pmcid, &pm)) != 0) 4215 break; 4216 4217 /* 4218 * The allocated PMC has to be a process virtual PMC, 4219 * i.e., of type MODE_T[CS]. Global PMCs can only be 4220 * read using the PMCREAD operation since they may be 4221 * allocated on a different CPU than the one we could 4222 * be running on at the time of the RDPMC instruction. 4223 * 4224 * The GETMSR operation is not allowed for PMCs that 4225 * are inherited across processes. 4226 */ 4227 4228 if (!PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)) || 4229 (pm->pm_flags & PMC_F_DESCENDANTS)) { 4230 error = EINVAL; 4231 break; 4232 } 4233 4234 /* 4235 * It only makes sense to use a RDPMC (or its 4236 * equivalent instruction on non-x86 architectures) on 4237 * a process that has allocated and attached a PMC to 4238 * itself. Conversely the PMC is only allowed to have 4239 * one process attached to it -- its owner. 4240 */ 4241 4242 if ((pt = LIST_FIRST(&pm->pm_targets)) == NULL || 4243 LIST_NEXT(pt, pt_next) != NULL || 4244 pt->pt_process->pp_proc != pm->pm_owner->po_owner) { 4245 error = EINVAL; 4246 break; 4247 } 4248 4249 ri = PMC_TO_ROWINDEX(pm); 4250 pcd = pmc_ri_to_classdep(md, ri, &adjri); 4251 4252 /* PMC class has no 'GETMSR' support */ 4253 if (pcd->pcd_get_msr == NULL) { 4254 error = ENOSYS; 4255 break; 4256 } 4257 4258 if ((error = (*pcd->pcd_get_msr)(adjri, &gm.pm_msr)) < 0) 4259 break; 4260 4261 if ((error = copyout(&gm, arg, sizeof(gm))) < 0) 4262 break; 4263 4264 /* 4265 * Mark our process as using MSRs. Update machine 4266 * state using a forced context switch. 4267 */ 4268 4269 pt->pt_process->pp_flags |= PMC_PP_ENABLE_MSR_ACCESS; 4270 pmc_force_context_switch(); 4271 4272 } 4273 break; 4274 4275 /* 4276 * Release an allocated PMC 4277 */ 4278 4279 case PMC_OP_PMCRELEASE: 4280 { 4281 pmc_id_t pmcid; 4282 struct pmc *pm; 4283 struct pmc_owner *po; 4284 struct pmc_op_simple sp; 4285 4286 /* 4287 * Find PMC pointer for the named PMC. 4288 * 4289 * Use pmc_release_pmc_descriptor() to switch off the 4290 * PMC, remove all its target threads, and remove the 4291 * PMC from its owner's list. 4292 * 4293 * Remove the owner record if this is the last PMC 4294 * owned. 4295 * 4296 * Free up space. 4297 */ 4298 4299 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 4300 break; 4301 4302 pmcid = sp.pm_pmcid; 4303 4304 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 4305 break; 4306 4307 po = pm->pm_owner; 4308 pmc_release_pmc_descriptor(pm); 4309 pmc_maybe_remove_owner(po); 4310 pmc_destroy_pmc_descriptor(pm); 4311 } 4312 break; 4313 4314 4315 /* 4316 * Read and/or write a PMC. 4317 */ 4318 4319 case PMC_OP_PMCRW: 4320 { 4321 int adjri; 4322 struct pmc *pm; 4323 uint32_t cpu, ri; 4324 pmc_value_t oldvalue; 4325 struct pmc_binding pb; 4326 struct pmc_op_pmcrw prw; 4327 struct pmc_classdep *pcd; 4328 struct pmc_op_pmcrw *pprw; 4329 4330 PMC_DOWNGRADE_SX(); 4331 4332 if ((error = copyin(arg, &prw, sizeof(prw))) != 0) 4333 break; 4334 4335 ri = 0; 4336 PMCDBG2(PMC,OPS,1, "rw id=%d flags=0x%x", prw.pm_pmcid, 4337 prw.pm_flags); 4338 4339 /* must have at least one flag set */ 4340 if ((prw.pm_flags & (PMC_F_OLDVALUE|PMC_F_NEWVALUE)) == 0) { 4341 error = EINVAL; 4342 break; 4343 } 4344 4345 /* locate pmc descriptor */ 4346 if ((error = pmc_find_pmc(prw.pm_pmcid, &pm)) != 0) 4347 break; 4348 4349 /* Can't read a PMC that hasn't been started. */ 4350 if (pm->pm_state != PMC_STATE_ALLOCATED && 4351 pm->pm_state != PMC_STATE_STOPPED && 4352 pm->pm_state != PMC_STATE_RUNNING) { 4353 error = EINVAL; 4354 break; 4355 } 4356 4357 /* writing a new value is allowed only for 'STOPPED' pmcs */ 4358 if (pm->pm_state == PMC_STATE_RUNNING && 4359 (prw.pm_flags & PMC_F_NEWVALUE)) { 4360 error = EBUSY; 4361 break; 4362 } 4363 4364 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) { 4365 4366 /* 4367 * If this PMC is attached to its owner (i.e., 4368 * the process requesting this operation) and 4369 * is running, then attempt to get an 4370 * upto-date reading from hardware for a READ. 4371 * Writes are only allowed when the PMC is 4372 * stopped, so only update the saved value 4373 * field. 4374 * 4375 * If the PMC is not running, or is not 4376 * attached to its owner, read/write to the 4377 * savedvalue field. 4378 */ 4379 4380 ri = PMC_TO_ROWINDEX(pm); 4381 pcd = pmc_ri_to_classdep(md, ri, &adjri); 4382 4383 mtx_pool_lock_spin(pmc_mtxpool, pm); 4384 cpu = curthread->td_oncpu; 4385 4386 if (prw.pm_flags & PMC_F_OLDVALUE) { 4387 if ((pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) && 4388 (pm->pm_state == PMC_STATE_RUNNING)) 4389 error = (*pcd->pcd_read_pmc)(cpu, adjri, 4390 &oldvalue); 4391 else 4392 oldvalue = pm->pm_gv.pm_savedvalue; 4393 } 4394 if (prw.pm_flags & PMC_F_NEWVALUE) 4395 pm->pm_gv.pm_savedvalue = prw.pm_value; 4396 4397 mtx_pool_unlock_spin(pmc_mtxpool, pm); 4398 4399 } else { /* System mode PMCs */ 4400 cpu = PMC_TO_CPU(pm); 4401 ri = PMC_TO_ROWINDEX(pm); 4402 pcd = pmc_ri_to_classdep(md, ri, &adjri); 4403 4404 if (!pmc_cpu_is_active(cpu)) { 4405 error = ENXIO; 4406 break; 4407 } 4408 4409 /* move this thread to CPU 'cpu' */ 4410 pmc_save_cpu_binding(&pb); 4411 pmc_select_cpu(cpu); 4412 4413 critical_enter(); 4414 /* save old value */ 4415 if (prw.pm_flags & PMC_F_OLDVALUE) 4416 if ((error = (*pcd->pcd_read_pmc)(cpu, adjri, 4417 &oldvalue))) 4418 goto error; 4419 /* write out new value */ 4420 if (prw.pm_flags & PMC_F_NEWVALUE) 4421 error = (*pcd->pcd_write_pmc)(cpu, adjri, 4422 prw.pm_value); 4423 error: 4424 critical_exit(); 4425 pmc_restore_cpu_binding(&pb); 4426 if (error) 4427 break; 4428 } 4429 4430 pprw = (struct pmc_op_pmcrw *) arg; 4431 4432 #ifdef HWPMC_DEBUG 4433 if (prw.pm_flags & PMC_F_NEWVALUE) 4434 PMCDBG3(PMC,OPS,2, "rw id=%d new %jx -> old %jx", 4435 ri, prw.pm_value, oldvalue); 4436 else if (prw.pm_flags & PMC_F_OLDVALUE) 4437 PMCDBG2(PMC,OPS,2, "rw id=%d -> old %jx", ri, oldvalue); 4438 #endif 4439 4440 /* return old value if requested */ 4441 if (prw.pm_flags & PMC_F_OLDVALUE) 4442 if ((error = copyout(&oldvalue, &pprw->pm_value, 4443 sizeof(prw.pm_value)))) 4444 break; 4445 4446 } 4447 break; 4448 4449 4450 /* 4451 * Set the sampling rate for a sampling mode PMC and the 4452 * initial count for a counting mode PMC. 4453 */ 4454 4455 case PMC_OP_PMCSETCOUNT: 4456 { 4457 struct pmc *pm; 4458 struct pmc_op_pmcsetcount sc; 4459 4460 PMC_DOWNGRADE_SX(); 4461 4462 if ((error = copyin(arg, &sc, sizeof(sc))) != 0) 4463 break; 4464 4465 if ((error = pmc_find_pmc(sc.pm_pmcid, &pm)) != 0) 4466 break; 4467 4468 if (pm->pm_state == PMC_STATE_RUNNING) { 4469 error = EBUSY; 4470 break; 4471 } 4472 4473 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) { 4474 /* 4475 * Don't permit requested sample rate to be less than 1000 4476 */ 4477 if (sc.pm_count < 1000) 4478 log(LOG_WARNING, 4479 "pmcsetcount: passed sample rate %ju - setting to 1000\n", 4480 (uintmax_t)sc.pm_count); 4481 pm->pm_sc.pm_reloadcount = MAX(1000, sc.pm_count); 4482 } else 4483 pm->pm_sc.pm_initial = sc.pm_count; 4484 } 4485 break; 4486 4487 4488 /* 4489 * Start a PMC. 4490 */ 4491 4492 case PMC_OP_PMCSTART: 4493 { 4494 pmc_id_t pmcid; 4495 struct pmc *pm; 4496 struct pmc_op_simple sp; 4497 4498 sx_assert(&pmc_sx, SX_XLOCKED); 4499 4500 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 4501 break; 4502 4503 pmcid = sp.pm_pmcid; 4504 4505 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 4506 break; 4507 4508 KASSERT(pmcid == pm->pm_id, 4509 ("[pmc,%d] pmcid %x != id %x", __LINE__, 4510 pm->pm_id, pmcid)); 4511 4512 if (pm->pm_state == PMC_STATE_RUNNING) /* already running */ 4513 break; 4514 else if (pm->pm_state != PMC_STATE_STOPPED && 4515 pm->pm_state != PMC_STATE_ALLOCATED) { 4516 error = EINVAL; 4517 break; 4518 } 4519 4520 error = pmc_start(pm); 4521 } 4522 break; 4523 4524 4525 /* 4526 * Stop a PMC. 4527 */ 4528 4529 case PMC_OP_PMCSTOP: 4530 { 4531 pmc_id_t pmcid; 4532 struct pmc *pm; 4533 struct pmc_op_simple sp; 4534 4535 PMC_DOWNGRADE_SX(); 4536 4537 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 4538 break; 4539 4540 pmcid = sp.pm_pmcid; 4541 4542 /* 4543 * Mark the PMC as inactive and invoke the MD stop 4544 * routines if needed. 4545 */ 4546 4547 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 4548 break; 4549 4550 KASSERT(pmcid == pm->pm_id, 4551 ("[pmc,%d] pmc id %x != pmcid %x", __LINE__, 4552 pm->pm_id, pmcid)); 4553 4554 if (pm->pm_state == PMC_STATE_STOPPED) /* already stopped */ 4555 break; 4556 else if (pm->pm_state != PMC_STATE_RUNNING) { 4557 error = EINVAL; 4558 break; 4559 } 4560 4561 error = pmc_stop(pm); 4562 } 4563 break; 4564 4565 4566 /* 4567 * Write a user supplied value to the log file. 4568 */ 4569 4570 case PMC_OP_WRITELOG: 4571 { 4572 struct pmc_op_writelog wl; 4573 struct pmc_owner *po; 4574 4575 PMC_DOWNGRADE_SX(); 4576 4577 if ((error = copyin(arg, &wl, sizeof(wl))) != 0) 4578 break; 4579 4580 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 4581 error = EINVAL; 4582 break; 4583 } 4584 4585 if ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) { 4586 error = EINVAL; 4587 break; 4588 } 4589 4590 error = pmclog_process_userlog(po, &wl); 4591 } 4592 break; 4593 4594 4595 default: 4596 error = EINVAL; 4597 break; 4598 } 4599 4600 if (is_sx_downgraded) 4601 sx_sunlock(&pmc_sx); 4602 else 4603 sx_xunlock(&pmc_sx); 4604 done_syscall: 4605 if (error) 4606 counter_u64_add(pmc_stats.pm_syscall_errors, 1); 4607 4608 return (error); 4609 } 4610 4611 /* 4612 * Helper functions 4613 */ 4614 4615 4616 /* 4617 * Mark the thread as needing callchain capture and post an AST. The 4618 * actual callchain capture will be done in a context where it is safe 4619 * to take page faults. 4620 */ 4621 4622 static void 4623 pmc_post_callchain_callback(void) 4624 { 4625 struct thread *td; 4626 4627 td = curthread; 4628 4629 /* 4630 * If there is multiple PMCs for the same interrupt ignore new post 4631 */ 4632 if (td->td_pflags & TDP_CALLCHAIN) 4633 return; 4634 4635 /* 4636 * Mark this thread as needing callchain capture. 4637 * `td->td_pflags' will be safe to touch because this thread 4638 * was in user space when it was interrupted. 4639 */ 4640 td->td_pflags |= TDP_CALLCHAIN; 4641 4642 /* 4643 * Don't let this thread migrate between CPUs until callchain 4644 * capture completes. 4645 */ 4646 sched_pin(); 4647 4648 return; 4649 } 4650 4651 /* 4652 * Find a free slot in the per-cpu array of samples and capture the 4653 * current callchain there. If a sample was successfully added, a bit 4654 * is set in mask 'pmc_cpumask' denoting that the DO_SAMPLES hook 4655 * needs to be invoked from the clock handler. 4656 * 4657 * This function is meant to be called from an NMI handler. It cannot 4658 * use any of the locking primitives supplied by the OS. 4659 */ 4660 4661 static int 4662 pmc_add_sample(ring_type_t ring, struct pmc *pm, struct trapframe *tf) 4663 { 4664 int error, cpu, callchaindepth, inuserspace; 4665 struct thread *td; 4666 struct pmc_sample *ps; 4667 struct pmc_samplebuffer *psb; 4668 4669 error = 0; 4670 4671 /* 4672 * Allocate space for a sample buffer. 4673 */ 4674 cpu = curcpu; 4675 psb = pmc_pcpu[cpu]->pc_sb[ring]; 4676 inuserspace = TRAPF_USERMODE(tf); 4677 ps = PMC_PROD_SAMPLE(psb); 4678 if (psb->ps_considx != psb->ps_prodidx && 4679 ps->ps_nsamples) { /* in use, reader hasn't caught up */ 4680 pm->pm_pcpu_state[cpu].pps_stalled = 1; 4681 counter_u64_add(pmc_stats.pm_intr_bufferfull, 1); 4682 PMCDBG6(SAM,INT,1,"(spc) cpu=%d pm=%p tf=%p um=%d wr=%d rd=%d", 4683 cpu, pm, (void *) tf, inuserspace, 4684 (int) (psb->ps_prodidx & pmc_sample_mask), 4685 (int) (psb->ps_considx & pmc_sample_mask)); 4686 callchaindepth = 1; 4687 error = ENOMEM; 4688 goto done; 4689 } 4690 4691 /* Fill in entry. */ 4692 PMCDBG6(SAM,INT,1,"cpu=%d pm=%p tf=%p um=%d wr=%d rd=%d", cpu, pm, 4693 (void *) tf, inuserspace, 4694 (int) (psb->ps_prodidx & pmc_sample_mask), 4695 (int) (psb->ps_considx & pmc_sample_mask)); 4696 4697 td = curthread; 4698 ps->ps_pmc = pm; 4699 ps->ps_td = td; 4700 ps->ps_pid = td->td_proc->p_pid; 4701 ps->ps_tid = td->td_tid; 4702 ps->ps_tsc = pmc_rdtsc(); 4703 ps->ps_ticks = ticks; 4704 ps->ps_cpu = cpu; 4705 ps->ps_flags = inuserspace ? PMC_CC_F_USERSPACE : 0; 4706 4707 callchaindepth = (pm->pm_flags & PMC_F_CALLCHAIN) ? 4708 pmc_callchaindepth : 1; 4709 4710 MPASS(ps->ps_pc != NULL); 4711 if (callchaindepth == 1) 4712 ps->ps_pc[0] = PMC_TRAPFRAME_TO_PC(tf); 4713 else { 4714 /* 4715 * Kernel stack traversals can be done immediately, 4716 * while we defer to an AST for user space traversals. 4717 */ 4718 if (!inuserspace) { 4719 callchaindepth = 4720 pmc_save_kernel_callchain(ps->ps_pc, 4721 callchaindepth, tf); 4722 } else { 4723 pmc_post_callchain_callback(); 4724 callchaindepth = PMC_USER_CALLCHAIN_PENDING; 4725 } 4726 } 4727 4728 ps->ps_nsamples = callchaindepth; /* mark entry as in use */ 4729 if (ring == PMC_UR) { 4730 ps->ps_nsamples_actual = callchaindepth; /* mark entry as in use */ 4731 ps->ps_nsamples = PMC_USER_CALLCHAIN_PENDING; 4732 } else 4733 ps->ps_nsamples = callchaindepth; /* mark entry as in use */ 4734 4735 KASSERT(counter_u64_fetch(pm->pm_runcount) >= 0, 4736 ("[pmc,%d] pm=%p runcount %ld", __LINE__, (void *) pm, 4737 (unsigned long)counter_u64_fetch(pm->pm_runcount))); 4738 4739 counter_u64_add(pm->pm_runcount, 1); /* hold onto PMC */ 4740 /* increment write pointer */ 4741 psb->ps_prodidx++; 4742 done: 4743 /* mark CPU as needing processing */ 4744 if (callchaindepth != PMC_USER_CALLCHAIN_PENDING) 4745 DPCPU_SET(pmc_sampled, 1); 4746 4747 return (error); 4748 } 4749 4750 /* 4751 * Interrupt processing. 4752 * 4753 * This function is meant to be called from an NMI handler. It cannot 4754 * use any of the locking primitives supplied by the OS. 4755 */ 4756 4757 int 4758 pmc_process_interrupt(int ring, struct pmc *pm, struct trapframe *tf) 4759 { 4760 struct thread *td; 4761 4762 td = curthread; 4763 if ((pm->pm_flags & PMC_F_USERCALLCHAIN) && 4764 (td->td_proc->p_flag & P_KPROC) == 0 && 4765 !TRAPF_USERMODE(tf)) { 4766 atomic_add_int(&td->td_pmcpend, 1); 4767 return (pmc_add_sample(PMC_UR, pm, tf)); 4768 } 4769 return (pmc_add_sample(ring, pm, tf)); 4770 } 4771 4772 /* 4773 * Capture a user call chain. This function will be called from ast() 4774 * before control returns to userland and before the process gets 4775 * rescheduled. 4776 */ 4777 4778 static void 4779 pmc_capture_user_callchain(int cpu, int ring, struct trapframe *tf) 4780 { 4781 struct pmc *pm; 4782 struct thread *td; 4783 struct pmc_sample *ps; 4784 struct pmc_samplebuffer *psb; 4785 uint64_t considx, prodidx; 4786 int nsamples, nrecords, pass, iter; 4787 #ifdef INVARIANTS 4788 int ncallchains; 4789 int nfree; 4790 int start_ticks = ticks; 4791 #endif 4792 psb = pmc_pcpu[cpu]->pc_sb[ring]; 4793 td = curthread; 4794 4795 KASSERT(td->td_pflags & TDP_CALLCHAIN, 4796 ("[pmc,%d] Retrieving callchain for thread that doesn't want it", 4797 __LINE__)); 4798 4799 #ifdef INVARIANTS 4800 ncallchains = 0; 4801 nfree = 0; 4802 #endif 4803 nrecords = INT_MAX; 4804 pass = 0; 4805 restart: 4806 if (ring == PMC_UR) 4807 nrecords = atomic_readandclear_32(&td->td_pmcpend); 4808 4809 for (iter = 0, considx = psb->ps_considx, prodidx = psb->ps_prodidx; 4810 considx < prodidx && iter < pmc_nsamples; considx++, iter++) { 4811 ps = PMC_CONS_SAMPLE_OFF(psb, considx); 4812 4813 /* 4814 * Iterate through all deferred callchain requests. 4815 * Walk from the current read pointer to the current 4816 * write pointer. 4817 */ 4818 4819 #ifdef INVARIANTS 4820 if (ps->ps_nsamples == PMC_SAMPLE_FREE) { 4821 nfree++; 4822 continue; 4823 } 4824 4825 if ((ps->ps_pmc == NULL) || 4826 (ps->ps_pmc->pm_state != PMC_STATE_RUNNING)) 4827 nfree++; 4828 #endif 4829 if (ps->ps_td != td || 4830 ps->ps_nsamples == PMC_USER_CALLCHAIN_PENDING || 4831 ps->ps_pmc->pm_state != PMC_STATE_RUNNING) 4832 continue; 4833 4834 KASSERT(ps->ps_cpu == cpu, 4835 ("[pmc,%d] cpu mismatch ps_cpu=%d pcpu=%d", __LINE__, 4836 ps->ps_cpu, PCPU_GET(cpuid))); 4837 4838 pm = ps->ps_pmc; 4839 4840 KASSERT(pm->pm_flags & PMC_F_CALLCHAIN, 4841 ("[pmc,%d] Retrieving callchain for PMC that doesn't " 4842 "want it", __LINE__)); 4843 4844 KASSERT(counter_u64_fetch(pm->pm_runcount) > 0, 4845 ("[pmc,%d] runcount %ld", __LINE__, (unsigned long)counter_u64_fetch(pm->pm_runcount))); 4846 4847 if (ring == PMC_UR) { 4848 nsamples = ps->ps_nsamples_actual; 4849 counter_u64_add(pmc_stats.pm_merges, 1); 4850 } else 4851 nsamples = 0; 4852 4853 /* 4854 * Retrieve the callchain and mark the sample buffer 4855 * as 'processable' by the timer tick sweep code. 4856 */ 4857 4858 #ifdef INVARIANTS 4859 ncallchains++; 4860 #endif 4861 4862 if (__predict_true(nsamples < pmc_callchaindepth - 1)) 4863 nsamples += pmc_save_user_callchain(ps->ps_pc + nsamples, 4864 pmc_callchaindepth - nsamples - 1, tf); 4865 4866 /* 4867 * We have to prevent hardclock from potentially overwriting 4868 * this sample between when we read the value and when we set 4869 * it 4870 */ 4871 spinlock_enter(); 4872 /* 4873 * Verify that the sample hasn't been dropped in the meantime 4874 */ 4875 if (ps->ps_nsamples == PMC_USER_CALLCHAIN_PENDING) { 4876 ps->ps_nsamples = nsamples; 4877 /* 4878 * If we couldn't get a sample, simply drop the reference 4879 */ 4880 if (nsamples == 0) 4881 counter_u64_add(pm->pm_runcount, -1); 4882 } 4883 spinlock_exit(); 4884 if (nrecords-- == 1) 4885 break; 4886 } 4887 if (__predict_false(ring == PMC_UR && td->td_pmcpend)) { 4888 if (pass == 0) { 4889 pass = 1; 4890 goto restart; 4891 } 4892 /* only collect samples for this part once */ 4893 td->td_pmcpend = 0; 4894 } 4895 4896 #ifdef INVARIANTS 4897 if ((ticks - start_ticks) > hz) 4898 log(LOG_ERR, "%s took %d ticks\n", __func__, (ticks - start_ticks)); 4899 #endif 4900 4901 /* mark CPU as needing processing */ 4902 DPCPU_SET(pmc_sampled, 1); 4903 } 4904 4905 /* 4906 * Process saved PC samples. 4907 */ 4908 4909 static void 4910 pmc_process_samples(int cpu, ring_type_t ring) 4911 { 4912 struct pmc *pm; 4913 int adjri, n; 4914 struct thread *td; 4915 struct pmc_owner *po; 4916 struct pmc_sample *ps; 4917 struct pmc_classdep *pcd; 4918 struct pmc_samplebuffer *psb; 4919 uint64_t delta; 4920 4921 KASSERT(PCPU_GET(cpuid) == cpu, 4922 ("[pmc,%d] not on the correct CPU pcpu=%d cpu=%d", __LINE__, 4923 PCPU_GET(cpuid), cpu)); 4924 4925 psb = pmc_pcpu[cpu]->pc_sb[ring]; 4926 delta = psb->ps_prodidx - psb->ps_considx; 4927 MPASS(delta <= pmc_nsamples); 4928 MPASS(psb->ps_considx <= psb->ps_prodidx); 4929 for (n = 0; psb->ps_considx < psb->ps_prodidx; psb->ps_considx++, n++) { 4930 ps = PMC_CONS_SAMPLE(psb); 4931 4932 if (__predict_false(ps->ps_nsamples == PMC_SAMPLE_FREE)) 4933 continue; 4934 pm = ps->ps_pmc; 4935 /* skip non-running samples */ 4936 if (pm->pm_state != PMC_STATE_RUNNING) 4937 goto entrydone; 4938 4939 KASSERT(counter_u64_fetch(pm->pm_runcount) > 0, 4940 ("[pmc,%d] pm=%p runcount %ld", __LINE__, (void *) pm, 4941 (unsigned long)counter_u64_fetch(pm->pm_runcount))); 4942 4943 po = pm->pm_owner; 4944 4945 KASSERT(PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)), 4946 ("[pmc,%d] pmc=%p non-sampling mode=%d", __LINE__, 4947 pm, PMC_TO_MODE(pm))); 4948 4949 4950 /* If there is a pending AST wait for completion */ 4951 if (ps->ps_nsamples == PMC_USER_CALLCHAIN_PENDING) { 4952 /* if sample is more than 65 ms old, drop it */ 4953 if (ticks - ps->ps_ticks > (hz >> 4)) { 4954 /* 4955 * track how often we hit this as it will 4956 * preferentially lose user samples 4957 * for long running system calls 4958 */ 4959 counter_u64_add(pmc_stats.pm_overwrites, 1); 4960 goto entrydone; 4961 } 4962 /* Need a rescan at a later time. */ 4963 DPCPU_SET(pmc_sampled, 1); 4964 break; 4965 } 4966 4967 PMCDBG6(SAM,OPS,1,"cpu=%d pm=%p n=%d fl=%x wr=%d rd=%d", cpu, 4968 pm, ps->ps_nsamples, ps->ps_flags, 4969 (int) (psb->ps_prodidx & pmc_sample_mask), 4970 (int) (psb->ps_considx & pmc_sample_mask)); 4971 4972 /* 4973 * If this is a process-mode PMC that is attached to 4974 * its owner, and if the PC is in user mode, update 4975 * profiling statistics like timer-based profiling 4976 * would have done. 4977 * 4978 * Otherwise, this is either a sampling-mode PMC that 4979 * is attached to a different process than its owner, 4980 * or a system-wide sampling PMC. Dispatch a log 4981 * entry to the PMC's owner process. 4982 */ 4983 if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) { 4984 if (ps->ps_flags & PMC_CC_F_USERSPACE) { 4985 td = FIRST_THREAD_IN_PROC(po->po_owner); 4986 addupc_intr(td, ps->ps_pc[0], 1); 4987 } 4988 } else 4989 pmclog_process_callchain(pm, ps); 4990 4991 entrydone: 4992 ps->ps_nsamples = 0; /* mark entry as free */ 4993 KASSERT(counter_u64_fetch(pm->pm_runcount) > 0, 4994 ("[pmc,%d] pm=%p runcount %ld", __LINE__, (void *) pm, 4995 (unsigned long)counter_u64_fetch(pm->pm_runcount))); 4996 4997 counter_u64_add(pm->pm_runcount, -1); 4998 } 4999 5000 counter_u64_add(pmc_stats.pm_log_sweeps, 1); 5001 5002 /* Do not re-enable stalled PMCs if we failed to process any samples */ 5003 if (n == 0) 5004 return; 5005 5006 /* 5007 * Restart any stalled sampling PMCs on this CPU. 5008 * 5009 * If the NMI handler sets the pm_stalled field of a PMC after 5010 * the check below, we'll end up processing the stalled PMC at 5011 * the next hardclock tick. 5012 */ 5013 for (n = 0; n < md->pmd_npmc; n++) { 5014 pcd = pmc_ri_to_classdep(md, n, &adjri); 5015 KASSERT(pcd != NULL, 5016 ("[pmc,%d] null pcd ri=%d", __LINE__, n)); 5017 (void) (*pcd->pcd_get_config)(cpu,adjri,&pm); 5018 5019 if (pm == NULL || /* !cfg'ed */ 5020 pm->pm_state != PMC_STATE_RUNNING || /* !active */ 5021 !PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)) || /* !sampling */ 5022 !pm->pm_pcpu_state[cpu].pps_cpustate || /* !desired */ 5023 !pm->pm_pcpu_state[cpu].pps_stalled) /* !stalled */ 5024 continue; 5025 5026 pm->pm_pcpu_state[cpu].pps_stalled = 0; 5027 (*pcd->pcd_start_pmc)(cpu, adjri); 5028 } 5029 } 5030 5031 /* 5032 * Event handlers. 5033 */ 5034 5035 /* 5036 * Handle a process exit. 5037 * 5038 * Remove this process from all hash tables. If this process 5039 * owned any PMCs, turn off those PMCs and deallocate them, 5040 * removing any associations with target processes. 5041 * 5042 * This function will be called by the last 'thread' of a 5043 * process. 5044 * 5045 * XXX This eventhandler gets called early in the exit process. 5046 * Consider using a 'hook' invocation from thread_exit() or equivalent 5047 * spot. Another negative is that kse_exit doesn't seem to call 5048 * exit1() [??]. 5049 * 5050 */ 5051 5052 static void 5053 pmc_process_exit(void *arg __unused, struct proc *p) 5054 { 5055 struct pmc *pm; 5056 int adjri, cpu; 5057 unsigned int ri; 5058 int is_using_hwpmcs; 5059 struct pmc_owner *po; 5060 struct pmc_process *pp; 5061 struct pmc_classdep *pcd; 5062 pmc_value_t newvalue, tmp; 5063 5064 PROC_LOCK(p); 5065 is_using_hwpmcs = p->p_flag & P_HWPMC; 5066 PROC_UNLOCK(p); 5067 5068 /* 5069 * Log a sysexit event to all SS PMC owners. 5070 */ 5071 PMC_EPOCH_ENTER(); 5072 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 5073 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 5074 pmclog_process_sysexit(po, p->p_pid); 5075 PMC_EPOCH_EXIT(); 5076 5077 if (!is_using_hwpmcs) 5078 return; 5079 5080 PMC_GET_SX_XLOCK(); 5081 PMCDBG3(PRC,EXT,1,"process-exit proc=%p (%d, %s)", p, p->p_pid, 5082 p->p_comm); 5083 5084 /* 5085 * Since this code is invoked by the last thread in an exiting 5086 * process, we would have context switched IN at some prior 5087 * point. However, with PREEMPTION, kernel mode context 5088 * switches may happen any time, so we want to disable a 5089 * context switch OUT till we get any PMCs targeting this 5090 * process off the hardware. 5091 * 5092 * We also need to atomically remove this process' 5093 * entry from our target process hash table, using 5094 * PMC_FLAG_REMOVE. 5095 */ 5096 PMCDBG3(PRC,EXT,1, "process-exit proc=%p (%d, %s)", p, p->p_pid, 5097 p->p_comm); 5098 5099 critical_enter(); /* no preemption */ 5100 5101 cpu = curthread->td_oncpu; 5102 5103 if ((pp = pmc_find_process_descriptor(p, 5104 PMC_FLAG_REMOVE)) != NULL) { 5105 5106 PMCDBG2(PRC,EXT,2, 5107 "process-exit proc=%p pmc-process=%p", p, pp); 5108 5109 /* 5110 * The exiting process could the target of 5111 * some PMCs which will be running on 5112 * currently executing CPU. 5113 * 5114 * We need to turn these PMCs off like we 5115 * would do at context switch OUT time. 5116 */ 5117 for (ri = 0; ri < md->pmd_npmc; ri++) { 5118 5119 /* 5120 * Pick up the pmc pointer from hardware 5121 * state similar to the CSW_OUT code. 5122 */ 5123 pm = NULL; 5124 5125 pcd = pmc_ri_to_classdep(md, ri, &adjri); 5126 5127 (void) (*pcd->pcd_get_config)(cpu, adjri, &pm); 5128 5129 PMCDBG2(PRC,EXT,2, "ri=%d pm=%p", ri, pm); 5130 5131 if (pm == NULL || 5132 !PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) 5133 continue; 5134 5135 PMCDBG4(PRC,EXT,2, "ppmcs[%d]=%p pm=%p " 5136 "state=%d", ri, pp->pp_pmcs[ri].pp_pmc, 5137 pm, pm->pm_state); 5138 5139 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 5140 ("[pmc,%d] ri mismatch pmc(%d) ri(%d)", 5141 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 5142 5143 KASSERT(pm == pp->pp_pmcs[ri].pp_pmc, 5144 ("[pmc,%d] pm %p != pp_pmcs[%d] %p", 5145 __LINE__, pm, ri, pp->pp_pmcs[ri].pp_pmc)); 5146 5147 KASSERT(counter_u64_fetch(pm->pm_runcount) > 0, 5148 ("[pmc,%d] bad runcount ri %d rc %ld", 5149 __LINE__, ri, (unsigned long)counter_u64_fetch(pm->pm_runcount))); 5150 5151 /* 5152 * Change desired state, and then stop if not 5153 * stalled. This two-step dance should avoid 5154 * race conditions where an interrupt re-enables 5155 * the PMC after this code has already checked 5156 * the pm_stalled flag. 5157 */ 5158 if (pm->pm_pcpu_state[cpu].pps_cpustate) { 5159 pm->pm_pcpu_state[cpu].pps_cpustate = 0; 5160 if (!pm->pm_pcpu_state[cpu].pps_stalled) { 5161 (void) pcd->pcd_stop_pmc(cpu, adjri); 5162 5163 if (PMC_TO_MODE(pm) == PMC_MODE_TC) { 5164 pcd->pcd_read_pmc(cpu, adjri, 5165 &newvalue); 5166 tmp = newvalue - 5167 PMC_PCPU_SAVED(cpu,ri); 5168 5169 mtx_pool_lock_spin(pmc_mtxpool, 5170 pm); 5171 pm->pm_gv.pm_savedvalue += tmp; 5172 pp->pp_pmcs[ri].pp_pmcval += 5173 tmp; 5174 mtx_pool_unlock_spin( 5175 pmc_mtxpool, pm); 5176 } 5177 } 5178 } 5179 5180 KASSERT((int64_t) counter_u64_fetch(pm->pm_runcount) > 0, 5181 ("[pmc,%d] runcount is %d", __LINE__, ri)); 5182 5183 counter_u64_add(pm->pm_runcount, -1); 5184 5185 (void) pcd->pcd_config_pmc(cpu, adjri, NULL); 5186 } 5187 5188 /* 5189 * Inform the MD layer of this pseudo "context switch 5190 * out" 5191 */ 5192 (void) md->pmd_switch_out(pmc_pcpu[cpu], pp); 5193 5194 critical_exit(); /* ok to be pre-empted now */ 5195 5196 /* 5197 * Unlink this process from the PMCs that are 5198 * targeting it. This will send a signal to 5199 * all PMC owner's whose PMCs are orphaned. 5200 * 5201 * Log PMC value at exit time if requested. 5202 */ 5203 for (ri = 0; ri < md->pmd_npmc; ri++) 5204 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) { 5205 if (pm->pm_flags & PMC_F_NEEDS_LOGFILE && 5206 PMC_IS_COUNTING_MODE(PMC_TO_MODE(pm))) 5207 pmclog_process_procexit(pm, pp); 5208 pmc_unlink_target_process(pm, pp); 5209 } 5210 free(pp, M_PMC); 5211 5212 } else 5213 critical_exit(); /* pp == NULL */ 5214 5215 5216 /* 5217 * If the process owned PMCs, free them up and free up 5218 * memory. 5219 */ 5220 if ((po = pmc_find_owner_descriptor(p)) != NULL) { 5221 pmc_remove_owner(po); 5222 pmc_destroy_owner_descriptor(po); 5223 } 5224 5225 sx_xunlock(&pmc_sx); 5226 } 5227 5228 /* 5229 * Handle a process fork. 5230 * 5231 * If the parent process 'p1' is under HWPMC monitoring, then copy 5232 * over any attached PMCs that have 'do_descendants' semantics. 5233 */ 5234 5235 static void 5236 pmc_process_fork(void *arg __unused, struct proc *p1, struct proc *newproc, 5237 int flags) 5238 { 5239 int is_using_hwpmcs; 5240 unsigned int ri; 5241 uint32_t do_descendants; 5242 struct pmc *pm; 5243 struct pmc_owner *po; 5244 struct pmc_process *ppnew, *ppold; 5245 5246 (void) flags; /* unused parameter */ 5247 5248 PROC_LOCK(p1); 5249 is_using_hwpmcs = p1->p_flag & P_HWPMC; 5250 PROC_UNLOCK(p1); 5251 5252 /* 5253 * If there are system-wide sampling PMCs active, we need to 5254 * log all fork events to their owner's logs. 5255 */ 5256 PMC_EPOCH_ENTER(); 5257 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 5258 if (po->po_flags & PMC_PO_OWNS_LOGFILE) { 5259 pmclog_process_procfork(po, p1->p_pid, newproc->p_pid); 5260 pmclog_process_proccreate(po, newproc, 1); 5261 } 5262 PMC_EPOCH_EXIT(); 5263 5264 if (!is_using_hwpmcs) 5265 return; 5266 5267 PMC_GET_SX_XLOCK(); 5268 PMCDBG4(PMC,FRK,1, "process-fork proc=%p (%d, %s) -> %p", p1, 5269 p1->p_pid, p1->p_comm, newproc); 5270 5271 /* 5272 * If the parent process (curthread->td_proc) is a 5273 * target of any PMCs, look for PMCs that are to be 5274 * inherited, and link these into the new process 5275 * descriptor. 5276 */ 5277 if ((ppold = pmc_find_process_descriptor(curthread->td_proc, 5278 PMC_FLAG_NONE)) == NULL) 5279 goto done; /* nothing to do */ 5280 5281 do_descendants = 0; 5282 for (ri = 0; ri < md->pmd_npmc; ri++) 5283 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL) 5284 do_descendants |= pm->pm_flags & PMC_F_DESCENDANTS; 5285 if (do_descendants == 0) /* nothing to do */ 5286 goto done; 5287 5288 /* 5289 * Now mark the new process as being tracked by this driver. 5290 */ 5291 PROC_LOCK(newproc); 5292 newproc->p_flag |= P_HWPMC; 5293 PROC_UNLOCK(newproc); 5294 5295 /* allocate a descriptor for the new process */ 5296 if ((ppnew = pmc_find_process_descriptor(newproc, 5297 PMC_FLAG_ALLOCATE)) == NULL) 5298 goto done; 5299 5300 /* 5301 * Run through all PMCs that were targeting the old process 5302 * and which specified F_DESCENDANTS and attach them to the 5303 * new process. 5304 * 5305 * Log the fork event to all owners of PMCs attached to this 5306 * process, if not already logged. 5307 */ 5308 for (ri = 0; ri < md->pmd_npmc; ri++) 5309 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL && 5310 (pm->pm_flags & PMC_F_DESCENDANTS)) { 5311 pmc_link_target_process(pm, ppnew); 5312 po = pm->pm_owner; 5313 if (po->po_sscount == 0 && 5314 po->po_flags & PMC_PO_OWNS_LOGFILE) 5315 pmclog_process_procfork(po, p1->p_pid, 5316 newproc->p_pid); 5317 } 5318 5319 done: 5320 sx_xunlock(&pmc_sx); 5321 } 5322 5323 static void 5324 pmc_process_threadcreate(struct thread *td) 5325 { 5326 struct pmc_owner *po; 5327 5328 PMC_EPOCH_ENTER(); 5329 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 5330 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 5331 pmclog_process_threadcreate(po, td, 1); 5332 PMC_EPOCH_EXIT(); 5333 } 5334 5335 static void 5336 pmc_process_threadexit(struct thread *td) 5337 { 5338 struct pmc_owner *po; 5339 5340 PMC_EPOCH_ENTER(); 5341 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 5342 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 5343 pmclog_process_threadexit(po, td); 5344 PMC_EPOCH_EXIT(); 5345 } 5346 5347 static void 5348 pmc_process_proccreate(struct proc *p) 5349 { 5350 struct pmc_owner *po; 5351 5352 PMC_EPOCH_ENTER(); 5353 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 5354 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 5355 pmclog_process_proccreate(po, p, 1 /* sync */); 5356 PMC_EPOCH_EXIT(); 5357 } 5358 5359 static void 5360 pmc_process_allproc(struct pmc *pm) 5361 { 5362 struct pmc_owner *po; 5363 struct thread *td; 5364 struct proc *p; 5365 5366 po = pm->pm_owner; 5367 if ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) 5368 return; 5369 sx_slock(&allproc_lock); 5370 FOREACH_PROC_IN_SYSTEM(p) { 5371 pmclog_process_proccreate(po, p, 0 /* sync */); 5372 PROC_LOCK(p); 5373 FOREACH_THREAD_IN_PROC(p, td) 5374 pmclog_process_threadcreate(po, td, 0 /* sync */); 5375 PROC_UNLOCK(p); 5376 } 5377 sx_sunlock(&allproc_lock); 5378 pmclog_flush(po, 0); 5379 } 5380 5381 static void 5382 pmc_kld_load(void *arg __unused, linker_file_t lf) 5383 { 5384 struct pmc_owner *po; 5385 5386 /* 5387 * Notify owners of system sampling PMCs about KLD operations. 5388 */ 5389 PMC_EPOCH_ENTER(); 5390 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 5391 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 5392 pmclog_process_map_in(po, (pid_t) -1, 5393 (uintfptr_t) lf->address, lf->filename); 5394 PMC_EPOCH_EXIT(); 5395 5396 /* 5397 * TODO: Notify owners of (all) process-sampling PMCs too. 5398 */ 5399 } 5400 5401 static void 5402 pmc_kld_unload(void *arg __unused, const char *filename __unused, 5403 caddr_t address, size_t size) 5404 { 5405 struct pmc_owner *po; 5406 5407 PMC_EPOCH_ENTER(); 5408 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 5409 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 5410 pmclog_process_map_out(po, (pid_t) -1, 5411 (uintfptr_t) address, (uintfptr_t) address + size); 5412 PMC_EPOCH_EXIT(); 5413 5414 /* 5415 * TODO: Notify owners of process-sampling PMCs. 5416 */ 5417 } 5418 5419 /* 5420 * initialization 5421 */ 5422 static const char * 5423 pmc_name_of_pmcclass(enum pmc_class class) 5424 { 5425 5426 switch (class) { 5427 #undef __PMC_CLASS 5428 #define __PMC_CLASS(S,V,D) \ 5429 case PMC_CLASS_##S: \ 5430 return #S; 5431 __PMC_CLASSES(); 5432 default: 5433 return ("<unknown>"); 5434 } 5435 } 5436 5437 /* 5438 * Base class initializer: allocate structure and set default classes. 5439 */ 5440 struct pmc_mdep * 5441 pmc_mdep_alloc(int nclasses) 5442 { 5443 struct pmc_mdep *md; 5444 int n; 5445 5446 /* SOFT + md classes */ 5447 n = 1 + nclasses; 5448 md = malloc(sizeof(struct pmc_mdep) + n * 5449 sizeof(struct pmc_classdep), M_PMC, M_WAITOK|M_ZERO); 5450 md->pmd_nclass = n; 5451 5452 /* Add base class. */ 5453 pmc_soft_initialize(md); 5454 return md; 5455 } 5456 5457 void 5458 pmc_mdep_free(struct pmc_mdep *md) 5459 { 5460 pmc_soft_finalize(md); 5461 free(md, M_PMC); 5462 } 5463 5464 static int 5465 generic_switch_in(struct pmc_cpu *pc, struct pmc_process *pp) 5466 { 5467 (void) pc; (void) pp; 5468 5469 return (0); 5470 } 5471 5472 static int 5473 generic_switch_out(struct pmc_cpu *pc, struct pmc_process *pp) 5474 { 5475 (void) pc; (void) pp; 5476 5477 return (0); 5478 } 5479 5480 static struct pmc_mdep * 5481 pmc_generic_cpu_initialize(void) 5482 { 5483 struct pmc_mdep *md; 5484 5485 md = pmc_mdep_alloc(0); 5486 5487 md->pmd_cputype = PMC_CPU_GENERIC; 5488 5489 md->pmd_pcpu_init = NULL; 5490 md->pmd_pcpu_fini = NULL; 5491 md->pmd_switch_in = generic_switch_in; 5492 md->pmd_switch_out = generic_switch_out; 5493 5494 return (md); 5495 } 5496 5497 static void 5498 pmc_generic_cpu_finalize(struct pmc_mdep *md) 5499 { 5500 (void) md; 5501 } 5502 5503 5504 static int 5505 pmc_initialize(void) 5506 { 5507 int c, cpu, error, n, ri; 5508 unsigned int maxcpu, domain; 5509 struct pcpu *pc; 5510 struct pmc_binding pb; 5511 struct pmc_sample *ps; 5512 struct pmc_classdep *pcd; 5513 struct pmc_samplebuffer *sb; 5514 5515 md = NULL; 5516 error = 0; 5517 5518 pmc_stats.pm_intr_ignored = counter_u64_alloc(M_WAITOK); 5519 pmc_stats.pm_intr_processed = counter_u64_alloc(M_WAITOK); 5520 pmc_stats.pm_intr_bufferfull = counter_u64_alloc(M_WAITOK); 5521 pmc_stats.pm_syscalls = counter_u64_alloc(M_WAITOK); 5522 pmc_stats.pm_syscall_errors = counter_u64_alloc(M_WAITOK); 5523 pmc_stats.pm_buffer_requests = counter_u64_alloc(M_WAITOK); 5524 pmc_stats.pm_buffer_requests_failed = counter_u64_alloc(M_WAITOK); 5525 pmc_stats.pm_log_sweeps = counter_u64_alloc(M_WAITOK); 5526 pmc_stats.pm_merges = counter_u64_alloc(M_WAITOK); 5527 pmc_stats.pm_overwrites = counter_u64_alloc(M_WAITOK); 5528 5529 #ifdef HWPMC_DEBUG 5530 /* parse debug flags first */ 5531 if (TUNABLE_STR_FETCH(PMC_SYSCTL_NAME_PREFIX "debugflags", 5532 pmc_debugstr, sizeof(pmc_debugstr))) 5533 pmc_debugflags_parse(pmc_debugstr, 5534 pmc_debugstr+strlen(pmc_debugstr)); 5535 #endif 5536 5537 PMCDBG1(MOD,INI,0, "PMC Initialize (version %x)", PMC_VERSION); 5538 5539 /* check kernel version */ 5540 if (pmc_kernel_version != PMC_VERSION) { 5541 if (pmc_kernel_version == 0) 5542 printf("hwpmc: this kernel has not been compiled with " 5543 "'options HWPMC_HOOKS'.\n"); 5544 else 5545 printf("hwpmc: kernel version (0x%x) does not match " 5546 "module version (0x%x).\n", pmc_kernel_version, 5547 PMC_VERSION); 5548 return EPROGMISMATCH; 5549 } 5550 5551 /* 5552 * check sysctl parameters 5553 */ 5554 5555 if (pmc_hashsize <= 0) { 5556 (void) printf("hwpmc: tunable \"hashsize\"=%d must be " 5557 "greater than zero.\n", pmc_hashsize); 5558 pmc_hashsize = PMC_HASH_SIZE; 5559 } 5560 5561 if (pmc_nsamples <= 0 || pmc_nsamples > 65535) { 5562 (void) printf("hwpmc: tunable \"nsamples\"=%d out of " 5563 "range.\n", pmc_nsamples); 5564 pmc_nsamples = PMC_NSAMPLES; 5565 } 5566 pmc_sample_mask = pmc_nsamples-1; 5567 5568 if (pmc_callchaindepth <= 0 || 5569 pmc_callchaindepth > PMC_CALLCHAIN_DEPTH_MAX) { 5570 (void) printf("hwpmc: tunable \"callchaindepth\"=%d out of " 5571 "range - using %d.\n", pmc_callchaindepth, 5572 PMC_CALLCHAIN_DEPTH_MAX); 5573 pmc_callchaindepth = PMC_CALLCHAIN_DEPTH_MAX; 5574 } 5575 5576 md = pmc_md_initialize(); 5577 if (md == NULL) { 5578 /* Default to generic CPU. */ 5579 md = pmc_generic_cpu_initialize(); 5580 if (md == NULL) 5581 return (ENOSYS); 5582 } 5583 5584 KASSERT(md->pmd_nclass >= 1 && md->pmd_npmc >= 1, 5585 ("[pmc,%d] no classes or pmcs", __LINE__)); 5586 5587 /* Compute the map from row-indices to classdep pointers. */ 5588 pmc_rowindex_to_classdep = malloc(sizeof(struct pmc_classdep *) * 5589 md->pmd_npmc, M_PMC, M_WAITOK|M_ZERO); 5590 5591 for (n = 0; n < md->pmd_npmc; n++) 5592 pmc_rowindex_to_classdep[n] = NULL; 5593 for (ri = c = 0; c < md->pmd_nclass; c++) { 5594 pcd = &md->pmd_classdep[c]; 5595 for (n = 0; n < pcd->pcd_num; n++, ri++) 5596 pmc_rowindex_to_classdep[ri] = pcd; 5597 } 5598 5599 KASSERT(ri == md->pmd_npmc, 5600 ("[pmc,%d] npmc miscomputed: ri=%d, md->npmc=%d", __LINE__, 5601 ri, md->pmd_npmc)); 5602 5603 maxcpu = pmc_cpu_max(); 5604 5605 /* allocate space for the per-cpu array */ 5606 pmc_pcpu = malloc(maxcpu * sizeof(struct pmc_cpu *), M_PMC, 5607 M_WAITOK|M_ZERO); 5608 5609 /* per-cpu 'saved values' for managing process-mode PMCs */ 5610 pmc_pcpu_saved = malloc(sizeof(pmc_value_t) * maxcpu * md->pmd_npmc, 5611 M_PMC, M_WAITOK); 5612 5613 /* Perform CPU-dependent initialization. */ 5614 pmc_save_cpu_binding(&pb); 5615 error = 0; 5616 for (cpu = 0; error == 0 && cpu < maxcpu; cpu++) { 5617 if (!pmc_cpu_is_active(cpu)) 5618 continue; 5619 pmc_select_cpu(cpu); 5620 pmc_pcpu[cpu] = malloc(sizeof(struct pmc_cpu) + 5621 md->pmd_npmc * sizeof(struct pmc_hw *), M_PMC, 5622 M_WAITOK|M_ZERO); 5623 if (md->pmd_pcpu_init) 5624 error = md->pmd_pcpu_init(md, cpu); 5625 for (n = 0; error == 0 && n < md->pmd_nclass; n++) 5626 error = md->pmd_classdep[n].pcd_pcpu_init(md, cpu); 5627 } 5628 pmc_restore_cpu_binding(&pb); 5629 5630 if (error) 5631 return (error); 5632 5633 /* allocate space for the sample array */ 5634 for (cpu = 0; cpu < maxcpu; cpu++) { 5635 if (!pmc_cpu_is_active(cpu)) 5636 continue; 5637 pc = pcpu_find(cpu); 5638 domain = pc->pc_domain; 5639 sb = malloc_domainset(sizeof(struct pmc_samplebuffer) + 5640 pmc_nsamples * sizeof(struct pmc_sample), M_PMC, 5641 DOMAINSET_PREF(domain), M_WAITOK | M_ZERO); 5642 5643 KASSERT(pmc_pcpu[cpu] != NULL, 5644 ("[pmc,%d] cpu=%d Null per-cpu data", __LINE__, cpu)); 5645 5646 sb->ps_callchains = malloc_domainset(pmc_callchaindepth * 5647 pmc_nsamples * sizeof(uintptr_t), M_PMC, 5648 DOMAINSET_PREF(domain), M_WAITOK | M_ZERO); 5649 5650 for (n = 0, ps = sb->ps_samples; n < pmc_nsamples; n++, ps++) 5651 ps->ps_pc = sb->ps_callchains + 5652 (n * pmc_callchaindepth); 5653 5654 pmc_pcpu[cpu]->pc_sb[PMC_HR] = sb; 5655 5656 sb = malloc_domainset(sizeof(struct pmc_samplebuffer) + 5657 pmc_nsamples * sizeof(struct pmc_sample), M_PMC, 5658 DOMAINSET_PREF(domain), M_WAITOK | M_ZERO); 5659 5660 sb->ps_callchains = malloc_domainset(pmc_callchaindepth * 5661 pmc_nsamples * sizeof(uintptr_t), M_PMC, 5662 DOMAINSET_PREF(domain), M_WAITOK | M_ZERO); 5663 for (n = 0, ps = sb->ps_samples; n < pmc_nsamples; n++, ps++) 5664 ps->ps_pc = sb->ps_callchains + 5665 (n * pmc_callchaindepth); 5666 5667 pmc_pcpu[cpu]->pc_sb[PMC_SR] = sb; 5668 5669 sb = malloc_domainset(sizeof(struct pmc_samplebuffer) + 5670 pmc_nsamples * sizeof(struct pmc_sample), M_PMC, 5671 DOMAINSET_PREF(domain), M_WAITOK | M_ZERO); 5672 sb->ps_callchains = malloc_domainset(pmc_callchaindepth * 5673 pmc_nsamples * sizeof(uintptr_t), M_PMC, 5674 DOMAINSET_PREF(domain), M_WAITOK | M_ZERO); 5675 for (n = 0, ps = sb->ps_samples; n < pmc_nsamples; n++, ps++) 5676 ps->ps_pc = sb->ps_callchains + n * pmc_callchaindepth; 5677 5678 pmc_pcpu[cpu]->pc_sb[PMC_UR] = sb; 5679 } 5680 5681 /* allocate space for the row disposition array */ 5682 pmc_pmcdisp = malloc(sizeof(enum pmc_mode) * md->pmd_npmc, 5683 M_PMC, M_WAITOK|M_ZERO); 5684 5685 /* mark all PMCs as available */ 5686 for (n = 0; n < (int) md->pmd_npmc; n++) 5687 PMC_MARK_ROW_FREE(n); 5688 5689 /* allocate thread hash tables */ 5690 pmc_ownerhash = hashinit(pmc_hashsize, M_PMC, 5691 &pmc_ownerhashmask); 5692 5693 pmc_processhash = hashinit(pmc_hashsize, M_PMC, 5694 &pmc_processhashmask); 5695 mtx_init(&pmc_processhash_mtx, "pmc-process-hash", "pmc-leaf", 5696 MTX_SPIN); 5697 5698 CK_LIST_INIT(&pmc_ss_owners); 5699 pmc_ss_count = 0; 5700 5701 /* allocate a pool of spin mutexes */ 5702 pmc_mtxpool = mtx_pool_create("pmc-leaf", pmc_mtxpool_size, 5703 MTX_SPIN); 5704 5705 PMCDBG4(MOD,INI,1, "pmc_ownerhash=%p, mask=0x%lx " 5706 "targethash=%p mask=0x%lx", pmc_ownerhash, pmc_ownerhashmask, 5707 pmc_processhash, pmc_processhashmask); 5708 5709 /* Initialize a spin mutex for the thread free list. */ 5710 mtx_init(&pmc_threadfreelist_mtx, "pmc-threadfreelist", "pmc-leaf", 5711 MTX_SPIN); 5712 5713 /* 5714 * Initialize the callout to monitor the thread free list. 5715 * This callout will also handle the initial population of the list. 5716 */ 5717 taskqgroup_config_gtask_init(NULL, &free_gtask, pmc_thread_descriptor_pool_free_task, "thread descriptor pool free task"); 5718 5719 /* register process {exit,fork,exec} handlers */ 5720 pmc_exit_tag = EVENTHANDLER_REGISTER(process_exit, 5721 pmc_process_exit, NULL, EVENTHANDLER_PRI_ANY); 5722 pmc_fork_tag = EVENTHANDLER_REGISTER(process_fork, 5723 pmc_process_fork, NULL, EVENTHANDLER_PRI_ANY); 5724 5725 /* register kld event handlers */ 5726 pmc_kld_load_tag = EVENTHANDLER_REGISTER(kld_load, pmc_kld_load, 5727 NULL, EVENTHANDLER_PRI_ANY); 5728 pmc_kld_unload_tag = EVENTHANDLER_REGISTER(kld_unload, pmc_kld_unload, 5729 NULL, EVENTHANDLER_PRI_ANY); 5730 5731 /* initialize logging */ 5732 pmclog_initialize(); 5733 5734 /* set hook functions */ 5735 pmc_intr = md->pmd_intr; 5736 wmb(); 5737 pmc_hook = pmc_hook_handler; 5738 5739 if (error == 0) { 5740 printf(PMC_MODULE_NAME ":"); 5741 for (n = 0; n < (int) md->pmd_nclass; n++) { 5742 pcd = &md->pmd_classdep[n]; 5743 printf(" %s/%d/%d/0x%b", 5744 pmc_name_of_pmcclass(pcd->pcd_class), 5745 pcd->pcd_num, 5746 pcd->pcd_width, 5747 pcd->pcd_caps, 5748 "\20" 5749 "\1INT\2USR\3SYS\4EDG\5THR" 5750 "\6REA\7WRI\10INV\11QUA\12PRC" 5751 "\13TAG\14CSC"); 5752 } 5753 printf("\n"); 5754 } 5755 5756 return (error); 5757 } 5758 5759 /* prepare to be unloaded */ 5760 static void 5761 pmc_cleanup(void) 5762 { 5763 int c, cpu; 5764 unsigned int maxcpu; 5765 struct pmc_ownerhash *ph; 5766 struct pmc_owner *po, *tmp; 5767 struct pmc_binding pb; 5768 #ifdef HWPMC_DEBUG 5769 struct pmc_processhash *prh; 5770 #endif 5771 5772 PMCDBG0(MOD,INI,0, "cleanup"); 5773 5774 /* switch off sampling */ 5775 CPU_FOREACH(cpu) 5776 DPCPU_ID_SET(cpu, pmc_sampled, 0); 5777 pmc_intr = NULL; 5778 5779 sx_xlock(&pmc_sx); 5780 if (pmc_hook == NULL) { /* being unloaded already */ 5781 sx_xunlock(&pmc_sx); 5782 return; 5783 } 5784 5785 pmc_hook = NULL; /* prevent new threads from entering module */ 5786 5787 /* deregister event handlers */ 5788 EVENTHANDLER_DEREGISTER(process_fork, pmc_fork_tag); 5789 EVENTHANDLER_DEREGISTER(process_exit, pmc_exit_tag); 5790 EVENTHANDLER_DEREGISTER(kld_load, pmc_kld_load_tag); 5791 EVENTHANDLER_DEREGISTER(kld_unload, pmc_kld_unload_tag); 5792 5793 /* send SIGBUS to all owner threads, free up allocations */ 5794 if (pmc_ownerhash) 5795 for (ph = pmc_ownerhash; 5796 ph <= &pmc_ownerhash[pmc_ownerhashmask]; 5797 ph++) { 5798 LIST_FOREACH_SAFE(po, ph, po_next, tmp) { 5799 pmc_remove_owner(po); 5800 5801 /* send SIGBUS to owner processes */ 5802 PMCDBG3(MOD,INI,2, "cleanup signal proc=%p " 5803 "(%d, %s)", po->po_owner, 5804 po->po_owner->p_pid, 5805 po->po_owner->p_comm); 5806 5807 PROC_LOCK(po->po_owner); 5808 kern_psignal(po->po_owner, SIGBUS); 5809 PROC_UNLOCK(po->po_owner); 5810 5811 pmc_destroy_owner_descriptor(po); 5812 } 5813 } 5814 5815 /* reclaim allocated data structures */ 5816 mtx_destroy(&pmc_threadfreelist_mtx); 5817 pmc_thread_descriptor_pool_drain(); 5818 5819 if (pmc_mtxpool) 5820 mtx_pool_destroy(&pmc_mtxpool); 5821 5822 mtx_destroy(&pmc_processhash_mtx); 5823 taskqgroup_config_gtask_deinit(&free_gtask); 5824 if (pmc_processhash) { 5825 #ifdef HWPMC_DEBUG 5826 struct pmc_process *pp; 5827 5828 PMCDBG0(MOD,INI,3, "destroy process hash"); 5829 for (prh = pmc_processhash; 5830 prh <= &pmc_processhash[pmc_processhashmask]; 5831 prh++) 5832 LIST_FOREACH(pp, prh, pp_next) 5833 PMCDBG1(MOD,INI,3, "pid=%d", pp->pp_proc->p_pid); 5834 #endif 5835 5836 hashdestroy(pmc_processhash, M_PMC, pmc_processhashmask); 5837 pmc_processhash = NULL; 5838 } 5839 5840 if (pmc_ownerhash) { 5841 PMCDBG0(MOD,INI,3, "destroy owner hash"); 5842 hashdestroy(pmc_ownerhash, M_PMC, pmc_ownerhashmask); 5843 pmc_ownerhash = NULL; 5844 } 5845 5846 KASSERT(CK_LIST_EMPTY(&pmc_ss_owners), 5847 ("[pmc,%d] Global SS owner list not empty", __LINE__)); 5848 KASSERT(pmc_ss_count == 0, 5849 ("[pmc,%d] Global SS count not empty", __LINE__)); 5850 5851 /* do processor and pmc-class dependent cleanup */ 5852 maxcpu = pmc_cpu_max(); 5853 5854 PMCDBG0(MOD,INI,3, "md cleanup"); 5855 if (md) { 5856 pmc_save_cpu_binding(&pb); 5857 for (cpu = 0; cpu < maxcpu; cpu++) { 5858 PMCDBG2(MOD,INI,1,"pmc-cleanup cpu=%d pcs=%p", 5859 cpu, pmc_pcpu[cpu]); 5860 if (!pmc_cpu_is_active(cpu) || pmc_pcpu[cpu] == NULL) 5861 continue; 5862 pmc_select_cpu(cpu); 5863 for (c = 0; c < md->pmd_nclass; c++) 5864 md->pmd_classdep[c].pcd_pcpu_fini(md, cpu); 5865 if (md->pmd_pcpu_fini) 5866 md->pmd_pcpu_fini(md, cpu); 5867 } 5868 5869 if (md->pmd_cputype == PMC_CPU_GENERIC) 5870 pmc_generic_cpu_finalize(md); 5871 else 5872 pmc_md_finalize(md); 5873 5874 pmc_mdep_free(md); 5875 md = NULL; 5876 pmc_restore_cpu_binding(&pb); 5877 } 5878 5879 /* Free per-cpu descriptors. */ 5880 for (cpu = 0; cpu < maxcpu; cpu++) { 5881 if (!pmc_cpu_is_active(cpu)) 5882 continue; 5883 KASSERT(pmc_pcpu[cpu]->pc_sb[PMC_HR] != NULL, 5884 ("[pmc,%d] Null hw cpu sample buffer cpu=%d", __LINE__, 5885 cpu)); 5886 KASSERT(pmc_pcpu[cpu]->pc_sb[PMC_SR] != NULL, 5887 ("[pmc,%d] Null sw cpu sample buffer cpu=%d", __LINE__, 5888 cpu)); 5889 KASSERT(pmc_pcpu[cpu]->pc_sb[PMC_UR] != NULL, 5890 ("[pmc,%d] Null userret cpu sample buffer cpu=%d", __LINE__, 5891 cpu)); 5892 free_domain(pmc_pcpu[cpu]->pc_sb[PMC_HR]->ps_callchains, M_PMC); 5893 free_domain(pmc_pcpu[cpu]->pc_sb[PMC_HR], M_PMC); 5894 free_domain(pmc_pcpu[cpu]->pc_sb[PMC_SR]->ps_callchains, M_PMC); 5895 free_domain(pmc_pcpu[cpu]->pc_sb[PMC_SR], M_PMC); 5896 free_domain(pmc_pcpu[cpu]->pc_sb[PMC_UR]->ps_callchains, M_PMC); 5897 free_domain(pmc_pcpu[cpu]->pc_sb[PMC_UR], M_PMC); 5898 free_domain(pmc_pcpu[cpu], M_PMC); 5899 } 5900 5901 free(pmc_pcpu, M_PMC); 5902 pmc_pcpu = NULL; 5903 5904 free(pmc_pcpu_saved, M_PMC); 5905 pmc_pcpu_saved = NULL; 5906 5907 if (pmc_pmcdisp) { 5908 free(pmc_pmcdisp, M_PMC); 5909 pmc_pmcdisp = NULL; 5910 } 5911 5912 if (pmc_rowindex_to_classdep) { 5913 free(pmc_rowindex_to_classdep, M_PMC); 5914 pmc_rowindex_to_classdep = NULL; 5915 } 5916 5917 pmclog_shutdown(); 5918 counter_u64_free(pmc_stats.pm_intr_ignored); 5919 counter_u64_free(pmc_stats.pm_intr_processed); 5920 counter_u64_free(pmc_stats.pm_intr_bufferfull); 5921 counter_u64_free(pmc_stats.pm_syscalls); 5922 counter_u64_free(pmc_stats.pm_syscall_errors); 5923 counter_u64_free(pmc_stats.pm_buffer_requests); 5924 counter_u64_free(pmc_stats.pm_buffer_requests_failed); 5925 counter_u64_free(pmc_stats.pm_log_sweeps); 5926 counter_u64_free(pmc_stats.pm_merges); 5927 counter_u64_free(pmc_stats.pm_overwrites); 5928 sx_xunlock(&pmc_sx); /* we are done */ 5929 } 5930 5931 /* 5932 * The function called at load/unload. 5933 */ 5934 5935 static int 5936 load (struct module *module __unused, int cmd, void *arg __unused) 5937 { 5938 int error; 5939 5940 error = 0; 5941 5942 switch (cmd) { 5943 case MOD_LOAD : 5944 /* initialize the subsystem */ 5945 error = pmc_initialize(); 5946 if (error != 0) 5947 break; 5948 PMCDBG2(MOD,INI,1, "syscall=%d maxcpu=%d", 5949 pmc_syscall_num, pmc_cpu_max()); 5950 break; 5951 5952 5953 case MOD_UNLOAD : 5954 case MOD_SHUTDOWN: 5955 pmc_cleanup(); 5956 PMCDBG0(MOD,INI,1, "unloaded"); 5957 break; 5958 5959 default : 5960 error = EINVAL; /* XXX should panic(9) */ 5961 break; 5962 } 5963 5964 return error; 5965 } 5966