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/eventhandler.h> 40 #include <sys/gtaskqueue.h> 41 #include <sys/jail.h> 42 #include <sys/kernel.h> 43 #include <sys/kthread.h> 44 #include <sys/limits.h> 45 #include <sys/lock.h> 46 #include <sys/malloc.h> 47 #include <sys/module.h> 48 #include <sys/mount.h> 49 #include <sys/mutex.h> 50 #include <sys/pmc.h> 51 #include <sys/pmckern.h> 52 #include <sys/pmclog.h> 53 #include <sys/priv.h> 54 #include <sys/proc.h> 55 #include <sys/queue.h> 56 #include <sys/resourcevar.h> 57 #include <sys/rwlock.h> 58 #include <sys/sched.h> 59 #include <sys/signalvar.h> 60 #include <sys/smp.h> 61 #include <sys/sx.h> 62 #include <sys/sysctl.h> 63 #include <sys/sysent.h> 64 #include <sys/syslog.h> 65 #include <sys/systm.h> 66 #include <sys/vnode.h> 67 68 #include <sys/linker.h> /* needs to be after <sys/malloc.h> */ 69 70 #include <machine/atomic.h> 71 #include <machine/md_var.h> 72 73 #include <vm/vm.h> 74 #include <vm/vm_extern.h> 75 #include <vm/pmap.h> 76 #include <vm/vm_map.h> 77 #include <vm/vm_object.h> 78 79 #include "hwpmc_soft.h" 80 81 #ifdef NUMA 82 #define NDOMAINS vm_ndomains 83 #else 84 #define NDOMAINS 1 85 #define malloc_domain(size, type, domain, flags) malloc((size), (type), (flags)) 86 #define free_domain(addr, type) free(addr, type) 87 #endif 88 89 #define PMC_EPOCH_ENTER() struct epoch_tracker pmc_et; epoch_enter_preempt(global_epoch_preempt, &pmc_et) 90 #define PMC_EPOCH_EXIT() epoch_exit_preempt(global_epoch_preempt, &pmc_et) 91 92 /* 93 * Types 94 */ 95 96 enum pmc_flags { 97 PMC_FLAG_NONE = 0x00, /* do nothing */ 98 PMC_FLAG_REMOVE = 0x01, /* atomically remove entry from hash */ 99 PMC_FLAG_ALLOCATE = 0x02, /* add entry to hash if not found */ 100 PMC_FLAG_NOWAIT = 0x04, /* do not wait for mallocs */ 101 }; 102 103 /* 104 * The offset in sysent where the syscall is allocated. 105 */ 106 107 static int pmc_syscall_num = NO_SYSCALL; 108 struct pmc_cpu **pmc_pcpu; /* per-cpu state */ 109 pmc_value_t *pmc_pcpu_saved; /* saved PMC values: CSW handling */ 110 111 #define PMC_PCPU_SAVED(C,R) pmc_pcpu_saved[(R) + md->pmd_npmc*(C)] 112 113 struct mtx_pool *pmc_mtxpool; 114 static int *pmc_pmcdisp; /* PMC row dispositions */ 115 116 #define PMC_ROW_DISP_IS_FREE(R) (pmc_pmcdisp[(R)] == 0) 117 #define PMC_ROW_DISP_IS_THREAD(R) (pmc_pmcdisp[(R)] > 0) 118 #define PMC_ROW_DISP_IS_STANDALONE(R) (pmc_pmcdisp[(R)] < 0) 119 120 #define PMC_MARK_ROW_FREE(R) do { \ 121 pmc_pmcdisp[(R)] = 0; \ 122 } while (0) 123 124 #define PMC_MARK_ROW_STANDALONE(R) do { \ 125 KASSERT(pmc_pmcdisp[(R)] <= 0, ("[pmc,%d] row disposition error", \ 126 __LINE__)); \ 127 atomic_add_int(&pmc_pmcdisp[(R)], -1); \ 128 KASSERT(pmc_pmcdisp[(R)] >= (-pmc_cpu_max_active()), \ 129 ("[pmc,%d] row disposition error", __LINE__)); \ 130 } while (0) 131 132 #define PMC_UNMARK_ROW_STANDALONE(R) do { \ 133 atomic_add_int(&pmc_pmcdisp[(R)], 1); \ 134 KASSERT(pmc_pmcdisp[(R)] <= 0, ("[pmc,%d] row disposition error", \ 135 __LINE__)); \ 136 } while (0) 137 138 #define PMC_MARK_ROW_THREAD(R) do { \ 139 KASSERT(pmc_pmcdisp[(R)] >= 0, ("[pmc,%d] row disposition error", \ 140 __LINE__)); \ 141 atomic_add_int(&pmc_pmcdisp[(R)], 1); \ 142 } while (0) 143 144 #define PMC_UNMARK_ROW_THREAD(R) do { \ 145 atomic_add_int(&pmc_pmcdisp[(R)], -1); \ 146 KASSERT(pmc_pmcdisp[(R)] >= 0, ("[pmc,%d] row disposition error", \ 147 __LINE__)); \ 148 } while (0) 149 150 151 /* various event handlers */ 152 static eventhandler_tag pmc_exit_tag, pmc_fork_tag, pmc_kld_load_tag, 153 pmc_kld_unload_tag; 154 155 /* Module statistics */ 156 struct pmc_driverstats pmc_stats; 157 158 159 /* Machine/processor dependent operations */ 160 static struct pmc_mdep *md; 161 162 /* 163 * Hash tables mapping owner processes and target threads to PMCs. 164 */ 165 166 struct mtx pmc_processhash_mtx; /* spin mutex */ 167 static u_long pmc_processhashmask; 168 static LIST_HEAD(pmc_processhash, pmc_process) *pmc_processhash; 169 170 /* 171 * Hash table of PMC owner descriptors. This table is protected by 172 * the shared PMC "sx" lock. 173 */ 174 175 static u_long pmc_ownerhashmask; 176 static LIST_HEAD(pmc_ownerhash, pmc_owner) *pmc_ownerhash; 177 178 /* 179 * List of PMC owners with system-wide sampling PMCs. 180 */ 181 182 static CK_LIST_HEAD(, pmc_owner) pmc_ss_owners; 183 184 /* 185 * List of free thread entries. This is protected by the spin 186 * mutex. 187 */ 188 static struct mtx pmc_threadfreelist_mtx; /* spin mutex */ 189 static LIST_HEAD(, pmc_thread) pmc_threadfreelist; 190 static int pmc_threadfreelist_entries=0; 191 #define THREADENTRY_SIZE \ 192 (sizeof(struct pmc_thread) + (md->pmd_npmc * sizeof(struct pmc_threadpmcstate))) 193 194 /* 195 * Task to free thread descriptors 196 */ 197 static struct grouptask free_gtask; 198 199 /* 200 * A map of row indices to classdep structures. 201 */ 202 static struct pmc_classdep **pmc_rowindex_to_classdep; 203 204 /* 205 * Prototypes 206 */ 207 208 #ifdef HWPMC_DEBUG 209 static int pmc_debugflags_sysctl_handler(SYSCTL_HANDLER_ARGS); 210 static int pmc_debugflags_parse(char *newstr, char *fence); 211 #endif 212 213 static int load(struct module *module, int cmd, void *arg); 214 static int pmc_add_sample(int ring, struct pmc *pm, struct trapframe *tf); 215 static void pmc_add_thread_descriptors_from_proc(struct proc *p, 216 struct pmc_process *pp); 217 static int pmc_attach_process(struct proc *p, struct pmc *pm); 218 static struct pmc *pmc_allocate_pmc_descriptor(void); 219 static struct pmc_owner *pmc_allocate_owner_descriptor(struct proc *p); 220 static int pmc_attach_one_process(struct proc *p, struct pmc *pm); 221 static int pmc_can_allocate_rowindex(struct proc *p, unsigned int ri, 222 int cpu); 223 static int pmc_can_attach(struct pmc *pm, struct proc *p); 224 static void pmc_capture_user_callchain(int cpu, int soft, struct trapframe *tf); 225 static void pmc_cleanup(void); 226 static int pmc_detach_process(struct proc *p, struct pmc *pm); 227 static int pmc_detach_one_process(struct proc *p, struct pmc *pm, 228 int flags); 229 static void pmc_destroy_owner_descriptor(struct pmc_owner *po); 230 static void pmc_destroy_pmc_descriptor(struct pmc *pm); 231 static void pmc_destroy_process_descriptor(struct pmc_process *pp); 232 static struct pmc_owner *pmc_find_owner_descriptor(struct proc *p); 233 static int pmc_find_pmc(pmc_id_t pmcid, struct pmc **pm); 234 static struct pmc *pmc_find_pmc_descriptor_in_process(struct pmc_owner *po, 235 pmc_id_t pmc); 236 static struct pmc_process *pmc_find_process_descriptor(struct proc *p, 237 uint32_t mode); 238 static struct pmc_thread *pmc_find_thread_descriptor(struct pmc_process *pp, 239 struct thread *td, uint32_t mode); 240 static void pmc_force_context_switch(void); 241 static void pmc_link_target_process(struct pmc *pm, 242 struct pmc_process *pp); 243 static void pmc_log_all_process_mappings(struct pmc_owner *po); 244 static void pmc_log_kernel_mappings(struct pmc *pm); 245 static void pmc_log_process_mappings(struct pmc_owner *po, struct proc *p); 246 static void pmc_maybe_remove_owner(struct pmc_owner *po); 247 static void pmc_process_csw_in(struct thread *td); 248 static void pmc_process_csw_out(struct thread *td); 249 static void pmc_process_exit(void *arg, struct proc *p); 250 static void pmc_process_fork(void *arg, struct proc *p1, 251 struct proc *p2, int n); 252 static void pmc_process_samples(int cpu, int soft); 253 static void pmc_release_pmc_descriptor(struct pmc *pmc); 254 static void pmc_process_thread_add(struct thread *td); 255 static void pmc_process_thread_delete(struct thread *td); 256 static void pmc_process_thread_userret(struct thread *td); 257 static void pmc_remove_owner(struct pmc_owner *po); 258 static void pmc_remove_process_descriptor(struct pmc_process *pp); 259 static void pmc_restore_cpu_binding(struct pmc_binding *pb); 260 static void pmc_save_cpu_binding(struct pmc_binding *pb); 261 static void pmc_select_cpu(int cpu); 262 static int pmc_start(struct pmc *pm); 263 static int pmc_stop(struct pmc *pm); 264 static int pmc_syscall_handler(struct thread *td, void *syscall_args); 265 static struct pmc_thread *pmc_thread_descriptor_pool_alloc(void); 266 static void pmc_thread_descriptor_pool_drain(void); 267 static void pmc_thread_descriptor_pool_free(struct pmc_thread *pt); 268 static void pmc_unlink_target_process(struct pmc *pmc, 269 struct pmc_process *pp); 270 static int generic_switch_in(struct pmc_cpu *pc, struct pmc_process *pp); 271 static int generic_switch_out(struct pmc_cpu *pc, struct pmc_process *pp); 272 static struct pmc_mdep *pmc_generic_cpu_initialize(void); 273 static void pmc_generic_cpu_finalize(struct pmc_mdep *md); 274 static void pmc_post_callchain_callback(void); 275 static void pmc_process_threadcreate(struct thread *td); 276 static void pmc_process_threadexit(struct thread *td); 277 static void pmc_process_proccreate(struct proc *p); 278 static void pmc_process_allproc(struct pmc *pm); 279 280 /* 281 * Kernel tunables and sysctl(8) interface. 282 */ 283 284 SYSCTL_DECL(_kern_hwpmc); 285 SYSCTL_NODE(_kern_hwpmc, OID_AUTO, stats, CTLFLAG_RW, 0, "HWPMC stats"); 286 287 288 /* Stats. */ 289 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, intr_ignored, CTLFLAG_RW, 290 &pmc_stats.pm_intr_ignored, "# of interrupts ignored"); 291 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, intr_processed, CTLFLAG_RW, 292 &pmc_stats.pm_intr_processed, "# of interrupts processed"); 293 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, intr_bufferfull, CTLFLAG_RW, 294 &pmc_stats.pm_intr_bufferfull, "# of interrupts where buffer was full"); 295 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, syscalls, CTLFLAG_RW, 296 &pmc_stats.pm_syscalls, "# of syscalls"); 297 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, syscall_errors, CTLFLAG_RW, 298 &pmc_stats.pm_syscall_errors, "# of syscall_errors"); 299 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, buffer_requests, CTLFLAG_RW, 300 &pmc_stats.pm_buffer_requests, "# of buffer requests"); 301 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, buffer_requests_failed, CTLFLAG_RW, 302 &pmc_stats.pm_buffer_requests_failed, "# of buffer requests which failed"); 303 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, log_sweeps, CTLFLAG_RW, 304 &pmc_stats.pm_log_sweeps, "# of ?"); 305 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, merges, CTLFLAG_RW, 306 &pmc_stats.pm_merges, "# of times kernel stack was found for user trace"); 307 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, overwrites, CTLFLAG_RW, 308 &pmc_stats.pm_overwrites, "# of times a sample was overwritten before being logged"); 309 310 static int pmc_callchaindepth = PMC_CALLCHAIN_DEPTH; 311 SYSCTL_INT(_kern_hwpmc, OID_AUTO, callchaindepth, CTLFLAG_RDTUN, 312 &pmc_callchaindepth, 0, "depth of call chain records"); 313 314 char pmc_cpuid[64]; 315 SYSCTL_STRING(_kern_hwpmc, OID_AUTO, cpuid, CTLFLAG_RD, 316 pmc_cpuid, 0, "cpu version string"); 317 #ifdef HWPMC_DEBUG 318 struct pmc_debugflags pmc_debugflags = PMC_DEBUG_DEFAULT_FLAGS; 319 char pmc_debugstr[PMC_DEBUG_STRSIZE]; 320 TUNABLE_STR(PMC_SYSCTL_NAME_PREFIX "debugflags", pmc_debugstr, 321 sizeof(pmc_debugstr)); 322 SYSCTL_PROC(_kern_hwpmc, OID_AUTO, debugflags, 323 CTLTYPE_STRING | CTLFLAG_RWTUN | CTLFLAG_NOFETCH, 324 0, 0, pmc_debugflags_sysctl_handler, "A", "debug flags"); 325 #endif 326 327 328 /* 329 * kern.hwpmc.hashrows -- determines the number of rows in the 330 * of the hash table used to look up threads 331 */ 332 333 static int pmc_hashsize = PMC_HASH_SIZE; 334 SYSCTL_INT(_kern_hwpmc, OID_AUTO, hashsize, CTLFLAG_RDTUN, 335 &pmc_hashsize, 0, "rows in hash tables"); 336 337 /* 338 * kern.hwpmc.nsamples --- number of PC samples/callchain stacks per CPU 339 */ 340 341 static int pmc_nsamples = PMC_NSAMPLES; 342 SYSCTL_INT(_kern_hwpmc, OID_AUTO, nsamples, CTLFLAG_RDTUN, 343 &pmc_nsamples, 0, "number of PC samples per CPU"); 344 345 346 /* 347 * kern.hwpmc.mtxpoolsize -- number of mutexes in the mutex pool. 348 */ 349 350 static int pmc_mtxpool_size = PMC_MTXPOOL_SIZE; 351 SYSCTL_INT(_kern_hwpmc, OID_AUTO, mtxpoolsize, CTLFLAG_RDTUN, 352 &pmc_mtxpool_size, 0, "size of spin mutex pool"); 353 354 355 /* 356 * kern.hwpmc.threadfreelist_entries -- number of free entries 357 */ 358 359 SYSCTL_INT(_kern_hwpmc, OID_AUTO, threadfreelist_entries, CTLFLAG_RD, 360 &pmc_threadfreelist_entries, 0, "number of avalable thread entries"); 361 362 363 /* 364 * kern.hwpmc.threadfreelist_max -- maximum number of free entries 365 */ 366 367 static int pmc_threadfreelist_max = PMC_THREADLIST_MAX; 368 SYSCTL_INT(_kern_hwpmc, OID_AUTO, threadfreelist_max, CTLFLAG_RW, 369 &pmc_threadfreelist_max, 0, 370 "maximum number of available thread entries before freeing some"); 371 372 373 /* 374 * security.bsd.unprivileged_syspmcs -- allow non-root processes to 375 * allocate system-wide PMCs. 376 * 377 * Allowing unprivileged processes to allocate system PMCs is convenient 378 * if system-wide measurements need to be taken concurrently with other 379 * per-process measurements. This feature is turned off by default. 380 */ 381 382 static int pmc_unprivileged_syspmcs = 0; 383 SYSCTL_INT(_security_bsd, OID_AUTO, unprivileged_syspmcs, CTLFLAG_RWTUN, 384 &pmc_unprivileged_syspmcs, 0, 385 "allow unprivileged process to allocate system PMCs"); 386 387 /* 388 * Hash function. Discard the lower 2 bits of the pointer since 389 * these are always zero for our uses. The hash multiplier is 390 * round((2^LONG_BIT) * ((sqrt(5)-1)/2)). 391 */ 392 393 #if LONG_BIT == 64 394 #define _PMC_HM 11400714819323198486u 395 #elif LONG_BIT == 32 396 #define _PMC_HM 2654435769u 397 #else 398 #error Must know the size of 'long' to compile 399 #endif 400 401 #define PMC_HASH_PTR(P,M) ((((unsigned long) (P) >> 2) * _PMC_HM) & (M)) 402 403 /* 404 * Syscall structures 405 */ 406 407 /* The `sysent' for the new syscall */ 408 static struct sysent pmc_sysent = { 409 .sy_narg = 2, 410 .sy_call = pmc_syscall_handler, 411 }; 412 413 static struct syscall_module_data pmc_syscall_mod = { 414 .chainevh = load, 415 .chainarg = NULL, 416 .offset = &pmc_syscall_num, 417 .new_sysent = &pmc_sysent, 418 .old_sysent = { .sy_narg = 0, .sy_call = NULL }, 419 .flags = SY_THR_STATIC_KLD, 420 }; 421 422 static moduledata_t pmc_mod = { 423 .name = PMC_MODULE_NAME, 424 .evhand = syscall_module_handler, 425 .priv = &pmc_syscall_mod, 426 }; 427 428 #ifdef EARLY_AP_STARTUP 429 DECLARE_MODULE(pmc, pmc_mod, SI_SUB_SYSCALLS, SI_ORDER_ANY); 430 #else 431 DECLARE_MODULE(pmc, pmc_mod, SI_SUB_SMP, SI_ORDER_ANY); 432 #endif 433 MODULE_VERSION(pmc, PMC_VERSION); 434 435 #ifdef HWPMC_DEBUG 436 enum pmc_dbgparse_state { 437 PMCDS_WS, /* in whitespace */ 438 PMCDS_MAJOR, /* seen a major keyword */ 439 PMCDS_MINOR 440 }; 441 442 static int 443 pmc_debugflags_parse(char *newstr, char *fence) 444 { 445 char c, *p, *q; 446 struct pmc_debugflags *tmpflags; 447 int error, found, *newbits, tmp; 448 size_t kwlen; 449 450 tmpflags = malloc(sizeof(*tmpflags), M_PMC, M_WAITOK|M_ZERO); 451 452 p = newstr; 453 error = 0; 454 455 for (; p < fence && (c = *p); p++) { 456 457 /* skip white space */ 458 if (c == ' ' || c == '\t') 459 continue; 460 461 /* look for a keyword followed by "=" */ 462 for (q = p; p < fence && (c = *p) && c != '='; p++) 463 ; 464 if (c != '=') { 465 error = EINVAL; 466 goto done; 467 } 468 469 kwlen = p - q; 470 newbits = NULL; 471 472 /* lookup flag group name */ 473 #define DBG_SET_FLAG_MAJ(S,F) \ 474 if (kwlen == sizeof(S)-1 && strncmp(q, S, kwlen) == 0) \ 475 newbits = &tmpflags->pdb_ ## F; 476 477 DBG_SET_FLAG_MAJ("cpu", CPU); 478 DBG_SET_FLAG_MAJ("csw", CSW); 479 DBG_SET_FLAG_MAJ("logging", LOG); 480 DBG_SET_FLAG_MAJ("module", MOD); 481 DBG_SET_FLAG_MAJ("md", MDP); 482 DBG_SET_FLAG_MAJ("owner", OWN); 483 DBG_SET_FLAG_MAJ("pmc", PMC); 484 DBG_SET_FLAG_MAJ("process", PRC); 485 DBG_SET_FLAG_MAJ("sampling", SAM); 486 487 if (newbits == NULL) { 488 error = EINVAL; 489 goto done; 490 } 491 492 p++; /* skip the '=' */ 493 494 /* Now parse the individual flags */ 495 tmp = 0; 496 newflag: 497 for (q = p; p < fence && (c = *p); p++) 498 if (c == ' ' || c == '\t' || c == ',') 499 break; 500 501 /* p == fence or c == ws or c == "," or c == 0 */ 502 503 if ((kwlen = p - q) == 0) { 504 *newbits = tmp; 505 continue; 506 } 507 508 found = 0; 509 #define DBG_SET_FLAG_MIN(S,F) \ 510 if (kwlen == sizeof(S)-1 && strncmp(q, S, kwlen) == 0) \ 511 tmp |= found = (1 << PMC_DEBUG_MIN_ ## F) 512 513 /* a '*' denotes all possible flags in the group */ 514 if (kwlen == 1 && *q == '*') 515 tmp = found = ~0; 516 /* look for individual flag names */ 517 DBG_SET_FLAG_MIN("allocaterow", ALR); 518 DBG_SET_FLAG_MIN("allocate", ALL); 519 DBG_SET_FLAG_MIN("attach", ATT); 520 DBG_SET_FLAG_MIN("bind", BND); 521 DBG_SET_FLAG_MIN("config", CFG); 522 DBG_SET_FLAG_MIN("exec", EXC); 523 DBG_SET_FLAG_MIN("exit", EXT); 524 DBG_SET_FLAG_MIN("find", FND); 525 DBG_SET_FLAG_MIN("flush", FLS); 526 DBG_SET_FLAG_MIN("fork", FRK); 527 DBG_SET_FLAG_MIN("getbuf", GTB); 528 DBG_SET_FLAG_MIN("hook", PMH); 529 DBG_SET_FLAG_MIN("init", INI); 530 DBG_SET_FLAG_MIN("intr", INT); 531 DBG_SET_FLAG_MIN("linktarget", TLK); 532 DBG_SET_FLAG_MIN("mayberemove", OMR); 533 DBG_SET_FLAG_MIN("ops", OPS); 534 DBG_SET_FLAG_MIN("read", REA); 535 DBG_SET_FLAG_MIN("register", REG); 536 DBG_SET_FLAG_MIN("release", REL); 537 DBG_SET_FLAG_MIN("remove", ORM); 538 DBG_SET_FLAG_MIN("sample", SAM); 539 DBG_SET_FLAG_MIN("scheduleio", SIO); 540 DBG_SET_FLAG_MIN("select", SEL); 541 DBG_SET_FLAG_MIN("signal", SIG); 542 DBG_SET_FLAG_MIN("swi", SWI); 543 DBG_SET_FLAG_MIN("swo", SWO); 544 DBG_SET_FLAG_MIN("start", STA); 545 DBG_SET_FLAG_MIN("stop", STO); 546 DBG_SET_FLAG_MIN("syscall", PMS); 547 DBG_SET_FLAG_MIN("unlinktarget", TUL); 548 DBG_SET_FLAG_MIN("write", WRI); 549 if (found == 0) { 550 /* unrecognized flag name */ 551 error = EINVAL; 552 goto done; 553 } 554 555 if (c == 0 || c == ' ' || c == '\t') { /* end of flag group */ 556 *newbits = tmp; 557 continue; 558 } 559 560 p++; 561 goto newflag; 562 } 563 564 /* save the new flag set */ 565 bcopy(tmpflags, &pmc_debugflags, sizeof(pmc_debugflags)); 566 567 done: 568 free(tmpflags, M_PMC); 569 return error; 570 } 571 572 static int 573 pmc_debugflags_sysctl_handler(SYSCTL_HANDLER_ARGS) 574 { 575 char *fence, *newstr; 576 int error; 577 unsigned int n; 578 579 (void) arg1; (void) arg2; /* unused parameters */ 580 581 n = sizeof(pmc_debugstr); 582 newstr = malloc(n, M_PMC, M_WAITOK|M_ZERO); 583 (void) strlcpy(newstr, pmc_debugstr, n); 584 585 error = sysctl_handle_string(oidp, newstr, n, req); 586 587 /* if there is a new string, parse and copy it */ 588 if (error == 0 && req->newptr != NULL) { 589 fence = newstr + (n < req->newlen ? n : req->newlen + 1); 590 if ((error = pmc_debugflags_parse(newstr, fence)) == 0) 591 (void) strlcpy(pmc_debugstr, newstr, 592 sizeof(pmc_debugstr)); 593 } 594 595 free(newstr, M_PMC); 596 597 return error; 598 } 599 #endif 600 601 /* 602 * Map a row index to a classdep structure and return the adjusted row 603 * index for the PMC class index. 604 */ 605 static struct pmc_classdep * 606 pmc_ri_to_classdep(struct pmc_mdep *md, int ri, int *adjri) 607 { 608 struct pmc_classdep *pcd; 609 610 (void) md; 611 612 KASSERT(ri >= 0 && ri < md->pmd_npmc, 613 ("[pmc,%d] illegal row-index %d", __LINE__, ri)); 614 615 pcd = pmc_rowindex_to_classdep[ri]; 616 617 KASSERT(pcd != NULL, 618 ("[pmc,%d] ri %d null pcd", __LINE__, ri)); 619 620 *adjri = ri - pcd->pcd_ri; 621 622 KASSERT(*adjri >= 0 && *adjri < pcd->pcd_num, 623 ("[pmc,%d] adjusted row-index %d", __LINE__, *adjri)); 624 625 return (pcd); 626 } 627 628 /* 629 * Concurrency Control 630 * 631 * The driver manages the following data structures: 632 * 633 * - target process descriptors, one per target process 634 * - owner process descriptors (and attached lists), one per owner process 635 * - lookup hash tables for owner and target processes 636 * - PMC descriptors (and attached lists) 637 * - per-cpu hardware state 638 * - the 'hook' variable through which the kernel calls into 639 * this module 640 * - the machine hardware state (managed by the MD layer) 641 * 642 * These data structures are accessed from: 643 * 644 * - thread context-switch code 645 * - interrupt handlers (possibly on multiple cpus) 646 * - kernel threads on multiple cpus running on behalf of user 647 * processes doing system calls 648 * - this driver's private kernel threads 649 * 650 * = Locks and Locking strategy = 651 * 652 * The driver uses four locking strategies for its operation: 653 * 654 * - The global SX lock "pmc_sx" is used to protect internal 655 * data structures. 656 * 657 * Calls into the module by syscall() start with this lock being 658 * held in exclusive mode. Depending on the requested operation, 659 * the lock may be downgraded to 'shared' mode to allow more 660 * concurrent readers into the module. Calls into the module from 661 * other parts of the kernel acquire the lock in shared mode. 662 * 663 * This SX lock is held in exclusive mode for any operations that 664 * modify the linkages between the driver's internal data structures. 665 * 666 * The 'pmc_hook' function pointer is also protected by this lock. 667 * It is only examined with the sx lock held in exclusive mode. The 668 * kernel module is allowed to be unloaded only with the sx lock held 669 * in exclusive mode. In normal syscall handling, after acquiring the 670 * pmc_sx lock we first check that 'pmc_hook' is non-null before 671 * proceeding. This prevents races between the thread unloading the module 672 * and other threads seeking to use the module. 673 * 674 * - Lookups of target process structures and owner process structures 675 * cannot use the global "pmc_sx" SX lock because these lookups need 676 * to happen during context switches and in other critical sections 677 * where sleeping is not allowed. We protect these lookup tables 678 * with their own private spin-mutexes, "pmc_processhash_mtx" and 679 * "pmc_ownerhash_mtx". 680 * 681 * - Interrupt handlers work in a lock free manner. At interrupt 682 * time, handlers look at the PMC pointer (phw->phw_pmc) configured 683 * when the PMC was started. If this pointer is NULL, the interrupt 684 * is ignored after updating driver statistics. We ensure that this 685 * pointer is set (using an atomic operation if necessary) before the 686 * PMC hardware is started. Conversely, this pointer is unset atomically 687 * only after the PMC hardware is stopped. 688 * 689 * We ensure that everything needed for the operation of an 690 * interrupt handler is available without it needing to acquire any 691 * locks. We also ensure that a PMC's software state is destroyed only 692 * after the PMC is taken off hardware (on all CPUs). 693 * 694 * - Context-switch handling with process-private PMCs needs more 695 * care. 696 * 697 * A given process may be the target of multiple PMCs. For example, 698 * PMCATTACH and PMCDETACH may be requested by a process on one CPU 699 * while the target process is running on another. A PMC could also 700 * be getting released because its owner is exiting. We tackle 701 * these situations in the following manner: 702 * 703 * - each target process structure 'pmc_process' has an array 704 * of 'struct pmc *' pointers, one for each hardware PMC. 705 * 706 * - At context switch IN time, each "target" PMC in RUNNING state 707 * gets started on hardware and a pointer to each PMC is copied into 708 * the per-cpu phw array. The 'runcount' for the PMC is 709 * incremented. 710 * 711 * - At context switch OUT time, all process-virtual PMCs are stopped 712 * on hardware. The saved value is added to the PMCs value field 713 * only if the PMC is in a non-deleted state (the PMCs state could 714 * have changed during the current time slice). 715 * 716 * Note that since in-between a switch IN on a processor and a switch 717 * OUT, the PMC could have been released on another CPU. Therefore 718 * context switch OUT always looks at the hardware state to turn 719 * OFF PMCs and will update a PMC's saved value only if reachable 720 * from the target process record. 721 * 722 * - OP PMCRELEASE could be called on a PMC at any time (the PMC could 723 * be attached to many processes at the time of the call and could 724 * be active on multiple CPUs). 725 * 726 * We prevent further scheduling of the PMC by marking it as in 727 * state 'DELETED'. If the runcount of the PMC is non-zero then 728 * this PMC is currently running on a CPU somewhere. The thread 729 * doing the PMCRELEASE operation waits by repeatedly doing a 730 * pause() till the runcount comes to zero. 731 * 732 * The contents of a PMC descriptor (struct pmc) are protected using 733 * a spin-mutex. In order to save space, we use a mutex pool. 734 * 735 * In terms of lock types used by witness(4), we use: 736 * - Type "pmc-sx", used by the global SX lock. 737 * - Type "pmc-sleep", for sleep mutexes used by logger threads. 738 * - Type "pmc-per-proc", for protecting PMC owner descriptors. 739 * - Type "pmc-leaf", used for all other spin mutexes. 740 */ 741 742 /* 743 * save the cpu binding of the current kthread 744 */ 745 746 static void 747 pmc_save_cpu_binding(struct pmc_binding *pb) 748 { 749 PMCDBG0(CPU,BND,2, "save-cpu"); 750 thread_lock(curthread); 751 pb->pb_bound = sched_is_bound(curthread); 752 pb->pb_cpu = curthread->td_oncpu; 753 thread_unlock(curthread); 754 PMCDBG1(CPU,BND,2, "save-cpu cpu=%d", pb->pb_cpu); 755 } 756 757 /* 758 * restore the cpu binding of the current thread 759 */ 760 761 static void 762 pmc_restore_cpu_binding(struct pmc_binding *pb) 763 { 764 PMCDBG2(CPU,BND,2, "restore-cpu curcpu=%d restore=%d", 765 curthread->td_oncpu, pb->pb_cpu); 766 thread_lock(curthread); 767 if (pb->pb_bound) 768 sched_bind(curthread, pb->pb_cpu); 769 else 770 sched_unbind(curthread); 771 thread_unlock(curthread); 772 PMCDBG0(CPU,BND,2, "restore-cpu done"); 773 } 774 775 /* 776 * move execution over the specified cpu and bind it there. 777 */ 778 779 static void 780 pmc_select_cpu(int cpu) 781 { 782 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 783 ("[pmc,%d] bad cpu number %d", __LINE__, cpu)); 784 785 /* Never move to an inactive CPU. */ 786 KASSERT(pmc_cpu_is_active(cpu), ("[pmc,%d] selecting inactive " 787 "CPU %d", __LINE__, cpu)); 788 789 PMCDBG1(CPU,SEL,2, "select-cpu cpu=%d", cpu); 790 thread_lock(curthread); 791 sched_bind(curthread, cpu); 792 thread_unlock(curthread); 793 794 KASSERT(curthread->td_oncpu == cpu, 795 ("[pmc,%d] CPU not bound [cpu=%d, curr=%d]", __LINE__, 796 cpu, curthread->td_oncpu)); 797 798 PMCDBG1(CPU,SEL,2, "select-cpu cpu=%d ok", cpu); 799 } 800 801 /* 802 * Force a context switch. 803 * 804 * We do this by pause'ing for 1 tick -- invoking mi_switch() is not 805 * guaranteed to force a context switch. 806 */ 807 808 static void 809 pmc_force_context_switch(void) 810 { 811 812 pause("pmcctx", 1); 813 } 814 815 uint64_t 816 pmc_rdtsc(void) 817 { 818 #if defined(__i386__) || defined(__amd64__) 819 if (__predict_true(amd_feature & AMDID_RDTSCP)) 820 return rdtscp(); 821 else 822 return rdtsc(); 823 #else 824 return get_cyclecount(); 825 #endif 826 } 827 828 /* 829 * Get the file name for an executable. This is a simple wrapper 830 * around vn_fullpath(9). 831 */ 832 833 static void 834 pmc_getfilename(struct vnode *v, char **fullpath, char **freepath) 835 { 836 837 *fullpath = "unknown"; 838 *freepath = NULL; 839 vn_fullpath(curthread, v, fullpath, freepath); 840 } 841 842 /* 843 * remove an process owning PMCs 844 */ 845 846 void 847 pmc_remove_owner(struct pmc_owner *po) 848 { 849 struct pmc *pm, *tmp; 850 851 sx_assert(&pmc_sx, SX_XLOCKED); 852 853 PMCDBG1(OWN,ORM,1, "remove-owner po=%p", po); 854 855 /* Remove descriptor from the owner hash table */ 856 LIST_REMOVE(po, po_next); 857 858 /* release all owned PMC descriptors */ 859 LIST_FOREACH_SAFE(pm, &po->po_pmcs, pm_next, tmp) { 860 PMCDBG1(OWN,ORM,2, "pmc=%p", pm); 861 KASSERT(pm->pm_owner == po, 862 ("[pmc,%d] owner %p != po %p", __LINE__, pm->pm_owner, po)); 863 864 pmc_release_pmc_descriptor(pm); /* will unlink from the list */ 865 pmc_destroy_pmc_descriptor(pm); 866 } 867 868 KASSERT(po->po_sscount == 0, 869 ("[pmc,%d] SS count not zero", __LINE__)); 870 KASSERT(LIST_EMPTY(&po->po_pmcs), 871 ("[pmc,%d] PMC list not empty", __LINE__)); 872 873 /* de-configure the log file if present */ 874 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 875 pmclog_deconfigure_log(po); 876 } 877 878 /* 879 * remove an owner process record if all conditions are met. 880 */ 881 882 static void 883 pmc_maybe_remove_owner(struct pmc_owner *po) 884 { 885 886 PMCDBG1(OWN,OMR,1, "maybe-remove-owner po=%p", po); 887 888 /* 889 * Remove owner record if 890 * - this process does not own any PMCs 891 * - this process has not allocated a system-wide sampling buffer 892 */ 893 894 if (LIST_EMPTY(&po->po_pmcs) && 895 ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0)) { 896 pmc_remove_owner(po); 897 pmc_destroy_owner_descriptor(po); 898 } 899 } 900 901 /* 902 * Add an association between a target process and a PMC. 903 */ 904 905 static void 906 pmc_link_target_process(struct pmc *pm, struct pmc_process *pp) 907 { 908 int ri; 909 struct pmc_target *pt; 910 #ifdef INVARIANTS 911 struct pmc_thread *pt_td; 912 #endif 913 914 sx_assert(&pmc_sx, SX_XLOCKED); 915 916 KASSERT(pm != NULL && pp != NULL, 917 ("[pmc,%d] Null pm %p or pp %p", __LINE__, pm, pp)); 918 KASSERT(PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)), 919 ("[pmc,%d] Attaching a non-process-virtual pmc=%p to pid=%d", 920 __LINE__, pm, pp->pp_proc->p_pid)); 921 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= ((int) md->pmd_npmc - 1), 922 ("[pmc,%d] Illegal reference count %d for process record %p", 923 __LINE__, pp->pp_refcnt, (void *) pp)); 924 925 ri = PMC_TO_ROWINDEX(pm); 926 927 PMCDBG3(PRC,TLK,1, "link-target pmc=%p ri=%d pmc-process=%p", 928 pm, ri, pp); 929 930 #ifdef HWPMC_DEBUG 931 LIST_FOREACH(pt, &pm->pm_targets, pt_next) 932 if (pt->pt_process == pp) 933 KASSERT(0, ("[pmc,%d] pp %p already in pmc %p targets", 934 __LINE__, pp, pm)); 935 #endif 936 937 pt = malloc(sizeof(struct pmc_target), M_PMC, M_WAITOK|M_ZERO); 938 pt->pt_process = pp; 939 940 LIST_INSERT_HEAD(&pm->pm_targets, pt, pt_next); 941 942 atomic_store_rel_ptr((uintptr_t *)&pp->pp_pmcs[ri].pp_pmc, 943 (uintptr_t)pm); 944 945 if (pm->pm_owner->po_owner == pp->pp_proc) 946 pm->pm_flags |= PMC_F_ATTACHED_TO_OWNER; 947 948 /* 949 * Initialize the per-process values at this row index. 950 */ 951 pp->pp_pmcs[ri].pp_pmcval = PMC_TO_MODE(pm) == PMC_MODE_TS ? 952 pm->pm_sc.pm_reloadcount : 0; 953 954 pp->pp_refcnt++; 955 956 #ifdef INVARIANTS 957 /* Confirm that the per-thread values at this row index are cleared. */ 958 if (PMC_TO_MODE(pm) == PMC_MODE_TS) { 959 mtx_lock_spin(pp->pp_tdslock); 960 LIST_FOREACH(pt_td, &pp->pp_tds, pt_next) { 961 KASSERT(pt_td->pt_pmcs[ri].pt_pmcval == (pmc_value_t) 0, 962 ("[pmc,%d] pt_pmcval not cleared for pid=%d at " 963 "ri=%d", __LINE__, pp->pp_proc->p_pid, ri)); 964 } 965 mtx_unlock_spin(pp->pp_tdslock); 966 } 967 #endif 968 } 969 970 /* 971 * Removes the association between a target process and a PMC. 972 */ 973 974 static void 975 pmc_unlink_target_process(struct pmc *pm, struct pmc_process *pp) 976 { 977 int ri; 978 struct proc *p; 979 struct pmc_target *ptgt; 980 struct pmc_thread *pt; 981 982 sx_assert(&pmc_sx, SX_XLOCKED); 983 984 KASSERT(pm != NULL && pp != NULL, 985 ("[pmc,%d] Null pm %p or pp %p", __LINE__, pm, pp)); 986 987 KASSERT(pp->pp_refcnt >= 1 && pp->pp_refcnt <= (int) md->pmd_npmc, 988 ("[pmc,%d] Illegal ref count %d on process record %p", 989 __LINE__, pp->pp_refcnt, (void *) pp)); 990 991 ri = PMC_TO_ROWINDEX(pm); 992 993 PMCDBG3(PRC,TUL,1, "unlink-target pmc=%p ri=%d pmc-process=%p", 994 pm, ri, pp); 995 996 KASSERT(pp->pp_pmcs[ri].pp_pmc == pm, 997 ("[pmc,%d] PMC ri %d mismatch pmc %p pp->[ri] %p", __LINE__, 998 ri, pm, pp->pp_pmcs[ri].pp_pmc)); 999 1000 pp->pp_pmcs[ri].pp_pmc = NULL; 1001 pp->pp_pmcs[ri].pp_pmcval = (pmc_value_t) 0; 1002 1003 /* Clear the per-thread values at this row index. */ 1004 if (PMC_TO_MODE(pm) == PMC_MODE_TS) { 1005 mtx_lock_spin(pp->pp_tdslock); 1006 LIST_FOREACH(pt, &pp->pp_tds, pt_next) 1007 pt->pt_pmcs[ri].pt_pmcval = (pmc_value_t) 0; 1008 mtx_unlock_spin(pp->pp_tdslock); 1009 } 1010 1011 /* Remove owner-specific flags */ 1012 if (pm->pm_owner->po_owner == pp->pp_proc) { 1013 pp->pp_flags &= ~PMC_PP_ENABLE_MSR_ACCESS; 1014 pm->pm_flags &= ~PMC_F_ATTACHED_TO_OWNER; 1015 } 1016 1017 pp->pp_refcnt--; 1018 1019 /* Remove the target process from the PMC structure */ 1020 LIST_FOREACH(ptgt, &pm->pm_targets, pt_next) 1021 if (ptgt->pt_process == pp) 1022 break; 1023 1024 KASSERT(ptgt != NULL, ("[pmc,%d] process %p (pp: %p) not found " 1025 "in pmc %p", __LINE__, pp->pp_proc, pp, pm)); 1026 1027 LIST_REMOVE(ptgt, pt_next); 1028 free(ptgt, M_PMC); 1029 1030 /* if the PMC now lacks targets, send the owner a SIGIO */ 1031 if (LIST_EMPTY(&pm->pm_targets)) { 1032 p = pm->pm_owner->po_owner; 1033 PROC_LOCK(p); 1034 kern_psignal(p, SIGIO); 1035 PROC_UNLOCK(p); 1036 1037 PMCDBG2(PRC,SIG,2, "signalling proc=%p signal=%d", p, 1038 SIGIO); 1039 } 1040 } 1041 1042 /* 1043 * Check if PMC 'pm' may be attached to target process 't'. 1044 */ 1045 1046 static int 1047 pmc_can_attach(struct pmc *pm, struct proc *t) 1048 { 1049 struct proc *o; /* pmc owner */ 1050 struct ucred *oc, *tc; /* owner, target credentials */ 1051 int decline_attach, i; 1052 1053 /* 1054 * A PMC's owner can always attach that PMC to itself. 1055 */ 1056 1057 if ((o = pm->pm_owner->po_owner) == t) 1058 return 0; 1059 1060 PROC_LOCK(o); 1061 oc = o->p_ucred; 1062 crhold(oc); 1063 PROC_UNLOCK(o); 1064 1065 PROC_LOCK(t); 1066 tc = t->p_ucred; 1067 crhold(tc); 1068 PROC_UNLOCK(t); 1069 1070 /* 1071 * The effective uid of the PMC owner should match at least one 1072 * of the {effective,real,saved} uids of the target process. 1073 */ 1074 1075 decline_attach = oc->cr_uid != tc->cr_uid && 1076 oc->cr_uid != tc->cr_svuid && 1077 oc->cr_uid != tc->cr_ruid; 1078 1079 /* 1080 * Every one of the target's group ids, must be in the owner's 1081 * group list. 1082 */ 1083 for (i = 0; !decline_attach && i < tc->cr_ngroups; i++) 1084 decline_attach = !groupmember(tc->cr_groups[i], oc); 1085 1086 /* check the read and saved gids too */ 1087 if (decline_attach == 0) 1088 decline_attach = !groupmember(tc->cr_rgid, oc) || 1089 !groupmember(tc->cr_svgid, oc); 1090 1091 crfree(tc); 1092 crfree(oc); 1093 1094 return !decline_attach; 1095 } 1096 1097 /* 1098 * Attach a process to a PMC. 1099 */ 1100 1101 static int 1102 pmc_attach_one_process(struct proc *p, struct pmc *pm) 1103 { 1104 int ri, error; 1105 char *fullpath, *freepath; 1106 struct pmc_process *pp; 1107 1108 sx_assert(&pmc_sx, SX_XLOCKED); 1109 1110 PMCDBG5(PRC,ATT,2, "attach-one pm=%p ri=%d proc=%p (%d, %s)", pm, 1111 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 1112 1113 /* 1114 * Locate the process descriptor corresponding to process 'p', 1115 * allocating space as needed. 1116 * 1117 * Verify that rowindex 'pm_rowindex' is free in the process 1118 * descriptor. 1119 * 1120 * If not, allocate space for a descriptor and link the 1121 * process descriptor and PMC. 1122 */ 1123 ri = PMC_TO_ROWINDEX(pm); 1124 1125 /* mark process as using HWPMCs */ 1126 PROC_LOCK(p); 1127 p->p_flag |= P_HWPMC; 1128 PROC_UNLOCK(p); 1129 1130 if ((pp = pmc_find_process_descriptor(p, PMC_FLAG_ALLOCATE)) == NULL) { 1131 error = ENOMEM; 1132 goto fail; 1133 } 1134 1135 if (pp->pp_pmcs[ri].pp_pmc == pm) {/* already present at slot [ri] */ 1136 error = EEXIST; 1137 goto fail; 1138 } 1139 1140 if (pp->pp_pmcs[ri].pp_pmc != NULL) { 1141 error = EBUSY; 1142 goto fail; 1143 } 1144 1145 pmc_link_target_process(pm, pp); 1146 1147 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)) && 1148 (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) == 0) 1149 pm->pm_flags |= PMC_F_NEEDS_LOGFILE; 1150 1151 pm->pm_flags |= PMC_F_ATTACH_DONE; /* mark as attached */ 1152 1153 /* issue an attach event to a configured log file */ 1154 if (pm->pm_owner->po_flags & PMC_PO_OWNS_LOGFILE) { 1155 if (p->p_flag & P_KPROC) { 1156 fullpath = kernelname; 1157 freepath = NULL; 1158 } else { 1159 pmc_getfilename(p->p_textvp, &fullpath, &freepath); 1160 pmclog_process_pmcattach(pm, p->p_pid, fullpath); 1161 } 1162 free(freepath, M_TEMP); 1163 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 1164 pmc_log_process_mappings(pm->pm_owner, p); 1165 } 1166 1167 return (0); 1168 fail: 1169 PROC_LOCK(p); 1170 p->p_flag &= ~P_HWPMC; 1171 PROC_UNLOCK(p); 1172 return (error); 1173 } 1174 1175 /* 1176 * Attach a process and optionally its children 1177 */ 1178 1179 static int 1180 pmc_attach_process(struct proc *p, struct pmc *pm) 1181 { 1182 int error; 1183 struct proc *top; 1184 1185 sx_assert(&pmc_sx, SX_XLOCKED); 1186 1187 PMCDBG5(PRC,ATT,1, "attach pm=%p ri=%d proc=%p (%d, %s)", pm, 1188 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 1189 1190 1191 /* 1192 * If this PMC successfully allowed a GETMSR operation 1193 * in the past, disallow further ATTACHes. 1194 */ 1195 1196 if ((pm->pm_flags & PMC_PP_ENABLE_MSR_ACCESS) != 0) 1197 return EPERM; 1198 1199 if ((pm->pm_flags & PMC_F_DESCENDANTS) == 0) 1200 return pmc_attach_one_process(p, pm); 1201 1202 /* 1203 * Traverse all child processes, attaching them to 1204 * this PMC. 1205 */ 1206 1207 sx_slock(&proctree_lock); 1208 1209 top = p; 1210 1211 for (;;) { 1212 if ((error = pmc_attach_one_process(p, pm)) != 0) 1213 break; 1214 if (!LIST_EMPTY(&p->p_children)) 1215 p = LIST_FIRST(&p->p_children); 1216 else for (;;) { 1217 if (p == top) 1218 goto done; 1219 if (LIST_NEXT(p, p_sibling)) { 1220 p = LIST_NEXT(p, p_sibling); 1221 break; 1222 } 1223 p = p->p_pptr; 1224 } 1225 } 1226 1227 if (error) 1228 (void) pmc_detach_process(top, pm); 1229 1230 done: 1231 sx_sunlock(&proctree_lock); 1232 return error; 1233 } 1234 1235 /* 1236 * Detach a process from a PMC. If there are no other PMCs tracking 1237 * this process, remove the process structure from its hash table. If 1238 * 'flags' contains PMC_FLAG_REMOVE, then free the process structure. 1239 */ 1240 1241 static int 1242 pmc_detach_one_process(struct proc *p, struct pmc *pm, int flags) 1243 { 1244 int ri; 1245 struct pmc_process *pp; 1246 1247 sx_assert(&pmc_sx, SX_XLOCKED); 1248 1249 KASSERT(pm != NULL, 1250 ("[pmc,%d] null pm pointer", __LINE__)); 1251 1252 ri = PMC_TO_ROWINDEX(pm); 1253 1254 PMCDBG6(PRC,ATT,2, "detach-one pm=%p ri=%d proc=%p (%d, %s) flags=0x%x", 1255 pm, ri, p, p->p_pid, p->p_comm, flags); 1256 1257 if ((pp = pmc_find_process_descriptor(p, 0)) == NULL) 1258 return ESRCH; 1259 1260 if (pp->pp_pmcs[ri].pp_pmc != pm) 1261 return EINVAL; 1262 1263 pmc_unlink_target_process(pm, pp); 1264 1265 /* Issue a detach entry if a log file is configured */ 1266 if (pm->pm_owner->po_flags & PMC_PO_OWNS_LOGFILE) 1267 pmclog_process_pmcdetach(pm, p->p_pid); 1268 1269 /* 1270 * If there are no PMCs targeting this process, we remove its 1271 * descriptor from the target hash table and unset the P_HWPMC 1272 * flag in the struct proc. 1273 */ 1274 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= (int) md->pmd_npmc, 1275 ("[pmc,%d] Illegal refcnt %d for process struct %p", 1276 __LINE__, pp->pp_refcnt, pp)); 1277 1278 if (pp->pp_refcnt != 0) /* still a target of some PMC */ 1279 return 0; 1280 1281 pmc_remove_process_descriptor(pp); 1282 1283 if (flags & PMC_FLAG_REMOVE) 1284 pmc_destroy_process_descriptor(pp); 1285 1286 PROC_LOCK(p); 1287 p->p_flag &= ~P_HWPMC; 1288 PROC_UNLOCK(p); 1289 1290 return 0; 1291 } 1292 1293 /* 1294 * Detach a process and optionally its descendants from a PMC. 1295 */ 1296 1297 static int 1298 pmc_detach_process(struct proc *p, struct pmc *pm) 1299 { 1300 struct proc *top; 1301 1302 sx_assert(&pmc_sx, SX_XLOCKED); 1303 1304 PMCDBG5(PRC,ATT,1, "detach pm=%p ri=%d proc=%p (%d, %s)", pm, 1305 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 1306 1307 if ((pm->pm_flags & PMC_F_DESCENDANTS) == 0) 1308 return pmc_detach_one_process(p, pm, PMC_FLAG_REMOVE); 1309 1310 /* 1311 * Traverse all children, detaching them from this PMC. We 1312 * ignore errors since we could be detaching a PMC from a 1313 * partially attached proc tree. 1314 */ 1315 1316 sx_slock(&proctree_lock); 1317 1318 top = p; 1319 1320 for (;;) { 1321 (void) pmc_detach_one_process(p, pm, PMC_FLAG_REMOVE); 1322 1323 if (!LIST_EMPTY(&p->p_children)) 1324 p = LIST_FIRST(&p->p_children); 1325 else for (;;) { 1326 if (p == top) 1327 goto done; 1328 if (LIST_NEXT(p, p_sibling)) { 1329 p = LIST_NEXT(p, p_sibling); 1330 break; 1331 } 1332 p = p->p_pptr; 1333 } 1334 } 1335 1336 done: 1337 sx_sunlock(&proctree_lock); 1338 1339 if (LIST_EMPTY(&pm->pm_targets)) 1340 pm->pm_flags &= ~PMC_F_ATTACH_DONE; 1341 1342 return 0; 1343 } 1344 1345 1346 /* 1347 * Thread context switch IN 1348 */ 1349 1350 static void 1351 pmc_process_csw_in(struct thread *td) 1352 { 1353 int cpu; 1354 unsigned int adjri, ri; 1355 struct pmc *pm; 1356 struct proc *p; 1357 struct pmc_cpu *pc; 1358 struct pmc_hw *phw; 1359 pmc_value_t newvalue; 1360 struct pmc_process *pp; 1361 struct pmc_thread *pt; 1362 struct pmc_classdep *pcd; 1363 1364 p = td->td_proc; 1365 pt = NULL; 1366 if ((pp = pmc_find_process_descriptor(p, PMC_FLAG_NONE)) == NULL) 1367 return; 1368 1369 KASSERT(pp->pp_proc == td->td_proc, 1370 ("[pmc,%d] not my thread state", __LINE__)); 1371 1372 critical_enter(); /* no preemption from this point */ 1373 1374 cpu = PCPU_GET(cpuid); /* td->td_oncpu is invalid */ 1375 1376 PMCDBG5(CSW,SWI,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p, 1377 p->p_pid, p->p_comm, pp); 1378 1379 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 1380 ("[pmc,%d] weird CPU id %d", __LINE__, cpu)); 1381 1382 pc = pmc_pcpu[cpu]; 1383 1384 for (ri = 0; ri < md->pmd_npmc; ri++) { 1385 1386 if ((pm = pp->pp_pmcs[ri].pp_pmc) == NULL) 1387 continue; 1388 1389 KASSERT(PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)), 1390 ("[pmc,%d] Target PMC in non-virtual mode (%d)", 1391 __LINE__, PMC_TO_MODE(pm))); 1392 1393 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 1394 ("[pmc,%d] Row index mismatch pmc %d != ri %d", 1395 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 1396 1397 /* 1398 * Only PMCs that are marked as 'RUNNING' need 1399 * be placed on hardware. 1400 */ 1401 1402 if (pm->pm_state != PMC_STATE_RUNNING) 1403 continue; 1404 1405 /* increment PMC runcount */ 1406 counter_u64_add(pm->pm_runcount, 1); 1407 1408 /* configure the HWPMC we are going to use. */ 1409 pcd = pmc_ri_to_classdep(md, ri, &adjri); 1410 pcd->pcd_config_pmc(cpu, adjri, pm); 1411 1412 phw = pc->pc_hwpmcs[ri]; 1413 1414 KASSERT(phw != NULL, 1415 ("[pmc,%d] null hw pointer", __LINE__)); 1416 1417 KASSERT(phw->phw_pmc == pm, 1418 ("[pmc,%d] hw->pmc %p != pmc %p", __LINE__, 1419 phw->phw_pmc, pm)); 1420 1421 /* 1422 * Write out saved value and start the PMC. 1423 * 1424 * Sampling PMCs use a per-thread value, while 1425 * counting mode PMCs use a per-pmc value that is 1426 * inherited across descendants. 1427 */ 1428 if (PMC_TO_MODE(pm) == PMC_MODE_TS) { 1429 if (pt == NULL) 1430 pt = pmc_find_thread_descriptor(pp, td, 1431 PMC_FLAG_NONE); 1432 1433 KASSERT(pt != NULL, 1434 ("[pmc,%d] No thread found for td=%p", __LINE__, 1435 td)); 1436 1437 mtx_pool_lock_spin(pmc_mtxpool, pm); 1438 1439 /* 1440 * If we have a thread descriptor, use the per-thread 1441 * counter in the descriptor. If not, we will use 1442 * a per-process counter. 1443 * 1444 * TODO: Remove the per-process "safety net" once 1445 * we have thoroughly tested that we don't hit the 1446 * above assert. 1447 */ 1448 if (pt != NULL) { 1449 if (pt->pt_pmcs[ri].pt_pmcval > 0) 1450 newvalue = pt->pt_pmcs[ri].pt_pmcval; 1451 else 1452 newvalue = pm->pm_sc.pm_reloadcount; 1453 } else { 1454 /* 1455 * Use the saved value calculated after the most 1456 * recent time a thread using the shared counter 1457 * switched out. Reset the saved count in case 1458 * another thread from this process switches in 1459 * before any threads switch out. 1460 */ 1461 1462 newvalue = pp->pp_pmcs[ri].pp_pmcval; 1463 pp->pp_pmcs[ri].pp_pmcval = 1464 pm->pm_sc.pm_reloadcount; 1465 } 1466 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1467 KASSERT(newvalue > 0 && newvalue <= 1468 pm->pm_sc.pm_reloadcount, 1469 ("[pmc,%d] pmcval outside of expected range cpu=%d " 1470 "ri=%d pmcval=%jx pm_reloadcount=%jx", __LINE__, 1471 cpu, ri, newvalue, pm->pm_sc.pm_reloadcount)); 1472 } else { 1473 KASSERT(PMC_TO_MODE(pm) == PMC_MODE_TC, 1474 ("[pmc,%d] illegal mode=%d", __LINE__, 1475 PMC_TO_MODE(pm))); 1476 mtx_pool_lock_spin(pmc_mtxpool, pm); 1477 newvalue = PMC_PCPU_SAVED(cpu, ri) = 1478 pm->pm_gv.pm_savedvalue; 1479 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1480 } 1481 1482 PMCDBG3(CSW,SWI,1,"cpu=%d ri=%d new=%jd", cpu, ri, newvalue); 1483 1484 pcd->pcd_write_pmc(cpu, adjri, newvalue); 1485 1486 /* If a sampling mode PMC, reset stalled state. */ 1487 if (PMC_TO_MODE(pm) == PMC_MODE_TS) 1488 pm->pm_pcpu_state[cpu].pps_stalled = 0; 1489 1490 /* Indicate that we desire this to run. */ 1491 pm->pm_pcpu_state[cpu].pps_cpustate = 1; 1492 1493 /* Start the PMC. */ 1494 pcd->pcd_start_pmc(cpu, adjri); 1495 } 1496 1497 /* 1498 * perform any other architecture/cpu dependent thread 1499 * switch-in actions. 1500 */ 1501 1502 (void) (*md->pmd_switch_in)(pc, pp); 1503 1504 critical_exit(); 1505 1506 } 1507 1508 /* 1509 * Thread context switch OUT. 1510 */ 1511 1512 static void 1513 pmc_process_csw_out(struct thread *td) 1514 { 1515 int cpu; 1516 int64_t tmp; 1517 struct pmc *pm; 1518 struct proc *p; 1519 enum pmc_mode mode; 1520 struct pmc_cpu *pc; 1521 pmc_value_t newvalue; 1522 unsigned int adjri, ri; 1523 struct pmc_process *pp; 1524 struct pmc_thread *pt = NULL; 1525 struct pmc_classdep *pcd; 1526 1527 1528 /* 1529 * Locate our process descriptor; this may be NULL if 1530 * this process is exiting and we have already removed 1531 * the process from the target process table. 1532 * 1533 * Note that due to kernel preemption, multiple 1534 * context switches may happen while the process is 1535 * exiting. 1536 * 1537 * Note also that if the target process cannot be 1538 * found we still need to deconfigure any PMCs that 1539 * are currently running on hardware. 1540 */ 1541 1542 p = td->td_proc; 1543 pp = pmc_find_process_descriptor(p, PMC_FLAG_NONE); 1544 1545 /* 1546 * save PMCs 1547 */ 1548 1549 critical_enter(); 1550 1551 cpu = PCPU_GET(cpuid); /* td->td_oncpu is invalid */ 1552 1553 PMCDBG5(CSW,SWO,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p, 1554 p->p_pid, p->p_comm, pp); 1555 1556 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 1557 ("[pmc,%d weird CPU id %d", __LINE__, cpu)); 1558 1559 pc = pmc_pcpu[cpu]; 1560 1561 /* 1562 * When a PMC gets unlinked from a target PMC, it will 1563 * be removed from the target's pp_pmc[] array. 1564 * 1565 * However, on a MP system, the target could have been 1566 * executing on another CPU at the time of the unlink. 1567 * So, at context switch OUT time, we need to look at 1568 * the hardware to determine if a PMC is scheduled on 1569 * it. 1570 */ 1571 1572 for (ri = 0; ri < md->pmd_npmc; ri++) { 1573 1574 pcd = pmc_ri_to_classdep(md, ri, &adjri); 1575 pm = NULL; 1576 (void) (*pcd->pcd_get_config)(cpu, adjri, &pm); 1577 1578 if (pm == NULL) /* nothing at this row index */ 1579 continue; 1580 1581 mode = PMC_TO_MODE(pm); 1582 if (!PMC_IS_VIRTUAL_MODE(mode)) 1583 continue; /* not a process virtual PMC */ 1584 1585 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 1586 ("[pmc,%d] ri mismatch pmc(%d) ri(%d)", 1587 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 1588 1589 /* 1590 * Change desired state, and then stop if not stalled. 1591 * This two-step dance should avoid race conditions where 1592 * an interrupt re-enables the PMC after this code has 1593 * already checked the pm_stalled flag. 1594 */ 1595 pm->pm_pcpu_state[cpu].pps_cpustate = 0; 1596 if (pm->pm_pcpu_state[cpu].pps_stalled == 0) 1597 pcd->pcd_stop_pmc(cpu, adjri); 1598 1599 /* reduce this PMC's runcount */ 1600 counter_u64_add(pm->pm_runcount, -1); 1601 1602 /* 1603 * If this PMC is associated with this process, 1604 * save the reading. 1605 */ 1606 1607 if (pm->pm_state != PMC_STATE_DELETED && pp != NULL && 1608 pp->pp_pmcs[ri].pp_pmc != NULL) { 1609 KASSERT(pm == pp->pp_pmcs[ri].pp_pmc, 1610 ("[pmc,%d] pm %p != pp_pmcs[%d] %p", __LINE__, 1611 pm, ri, pp->pp_pmcs[ri].pp_pmc)); 1612 1613 KASSERT(pp->pp_refcnt > 0, 1614 ("[pmc,%d] pp refcnt = %d", __LINE__, 1615 pp->pp_refcnt)); 1616 1617 pcd->pcd_read_pmc(cpu, adjri, &newvalue); 1618 1619 if (mode == PMC_MODE_TS) { 1620 PMCDBG3(CSW,SWO,1,"cpu=%d ri=%d val=%jd (samp)", 1621 cpu, ri, newvalue); 1622 1623 if (pt == NULL) 1624 pt = pmc_find_thread_descriptor(pp, td, 1625 PMC_FLAG_NONE); 1626 1627 KASSERT(pt != NULL, 1628 ("[pmc,%d] No thread found for td=%p", 1629 __LINE__, td)); 1630 1631 mtx_pool_lock_spin(pmc_mtxpool, pm); 1632 1633 /* 1634 * If we have a thread descriptor, save the 1635 * per-thread counter in the descriptor. If not, 1636 * we will update the per-process counter. 1637 * 1638 * TODO: Remove the per-process "safety net" 1639 * once we have thoroughly tested that we 1640 * don't hit the above assert. 1641 */ 1642 if (pt != NULL) 1643 pt->pt_pmcs[ri].pt_pmcval = newvalue; 1644 else { 1645 /* 1646 * For sampling process-virtual PMCs, 1647 * newvalue is the number of events to 1648 * be seen until the next sampling 1649 * interrupt. We can just add the events 1650 * left from this invocation to the 1651 * counter, then adjust in case we 1652 * overflow our range. 1653 * 1654 * (Recall that we reload the counter 1655 * every time we use it.) 1656 */ 1657 pp->pp_pmcs[ri].pp_pmcval += newvalue; 1658 if (pp->pp_pmcs[ri].pp_pmcval > 1659 pm->pm_sc.pm_reloadcount) 1660 pp->pp_pmcs[ri].pp_pmcval -= 1661 pm->pm_sc.pm_reloadcount; 1662 } 1663 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1664 } else { 1665 tmp = newvalue - PMC_PCPU_SAVED(cpu,ri); 1666 1667 PMCDBG3(CSW,SWO,1,"cpu=%d ri=%d tmp=%jd (count)", 1668 cpu, ri, tmp); 1669 1670 /* 1671 * For counting process-virtual PMCs, 1672 * we expect the count to be 1673 * increasing monotonically, modulo a 64 1674 * bit wraparound. 1675 */ 1676 KASSERT(tmp >= 0, 1677 ("[pmc,%d] negative increment cpu=%d " 1678 "ri=%d newvalue=%jx saved=%jx " 1679 "incr=%jx", __LINE__, cpu, ri, 1680 newvalue, PMC_PCPU_SAVED(cpu,ri), tmp)); 1681 1682 mtx_pool_lock_spin(pmc_mtxpool, pm); 1683 pm->pm_gv.pm_savedvalue += tmp; 1684 pp->pp_pmcs[ri].pp_pmcval += tmp; 1685 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1686 1687 if (pm->pm_flags & PMC_F_LOG_PROCCSW) 1688 pmclog_process_proccsw(pm, pp, tmp, td); 1689 } 1690 } 1691 1692 /* mark hardware as free */ 1693 pcd->pcd_config_pmc(cpu, adjri, NULL); 1694 } 1695 1696 /* 1697 * perform any other architecture/cpu dependent thread 1698 * switch out functions. 1699 */ 1700 1701 (void) (*md->pmd_switch_out)(pc, pp); 1702 1703 critical_exit(); 1704 } 1705 1706 /* 1707 * A new thread for a process. 1708 */ 1709 static void 1710 pmc_process_thread_add(struct thread *td) 1711 { 1712 struct pmc_process *pmc; 1713 1714 pmc = pmc_find_process_descriptor(td->td_proc, PMC_FLAG_NONE); 1715 if (pmc != NULL) 1716 pmc_find_thread_descriptor(pmc, td, PMC_FLAG_ALLOCATE); 1717 } 1718 1719 /* 1720 * A thread delete for a process. 1721 */ 1722 static void 1723 pmc_process_thread_delete(struct thread *td) 1724 { 1725 struct pmc_process *pmc; 1726 1727 pmc = pmc_find_process_descriptor(td->td_proc, PMC_FLAG_NONE); 1728 if (pmc != NULL) 1729 pmc_thread_descriptor_pool_free(pmc_find_thread_descriptor(pmc, 1730 td, PMC_FLAG_REMOVE)); 1731 } 1732 1733 /* 1734 * A userret() call for a thread. 1735 */ 1736 static void 1737 pmc_process_thread_userret(struct thread *td) 1738 { 1739 sched_pin(); 1740 pmc_capture_user_callchain(curcpu, PMC_UR, td->td_frame); 1741 sched_unpin(); 1742 } 1743 1744 /* 1745 * A mapping change for a process. 1746 */ 1747 1748 static void 1749 pmc_process_mmap(struct thread *td, struct pmckern_map_in *pkm) 1750 { 1751 int ri; 1752 pid_t pid; 1753 char *fullpath, *freepath; 1754 const struct pmc *pm; 1755 struct pmc_owner *po; 1756 const struct pmc_process *pp; 1757 1758 freepath = fullpath = NULL; 1759 MPASS(!in_epoch(global_epoch_preempt)); 1760 pmc_getfilename((struct vnode *) pkm->pm_file, &fullpath, &freepath); 1761 1762 pid = td->td_proc->p_pid; 1763 1764 PMC_EPOCH_ENTER(); 1765 /* Inform owners of all system-wide sampling PMCs. */ 1766 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1767 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1768 pmclog_process_map_in(po, pid, pkm->pm_address, fullpath); 1769 1770 if ((pp = pmc_find_process_descriptor(td->td_proc, 0)) == NULL) 1771 goto done; 1772 1773 /* 1774 * Inform sampling PMC owners tracking this process. 1775 */ 1776 for (ri = 0; ri < md->pmd_npmc; ri++) 1777 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL && 1778 PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 1779 pmclog_process_map_in(pm->pm_owner, 1780 pid, pkm->pm_address, fullpath); 1781 1782 done: 1783 if (freepath) 1784 free(freepath, M_TEMP); 1785 PMC_EPOCH_EXIT(); 1786 } 1787 1788 1789 /* 1790 * Log an munmap request. 1791 */ 1792 1793 static void 1794 pmc_process_munmap(struct thread *td, struct pmckern_map_out *pkm) 1795 { 1796 int ri; 1797 pid_t pid; 1798 struct pmc_owner *po; 1799 const struct pmc *pm; 1800 const struct pmc_process *pp; 1801 1802 pid = td->td_proc->p_pid; 1803 1804 PMC_EPOCH_ENTER(); 1805 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1806 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1807 pmclog_process_map_out(po, pid, pkm->pm_address, 1808 pkm->pm_address + pkm->pm_size); 1809 PMC_EPOCH_EXIT(); 1810 1811 if ((pp = pmc_find_process_descriptor(td->td_proc, 0)) == NULL) 1812 return; 1813 1814 for (ri = 0; ri < md->pmd_npmc; ri++) 1815 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL && 1816 PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 1817 pmclog_process_map_out(pm->pm_owner, pid, 1818 pkm->pm_address, pkm->pm_address + pkm->pm_size); 1819 } 1820 1821 /* 1822 * Log mapping information about the kernel. 1823 */ 1824 1825 static void 1826 pmc_log_kernel_mappings(struct pmc *pm) 1827 { 1828 struct pmc_owner *po; 1829 struct pmckern_map_in *km, *kmbase; 1830 1831 MPASS(in_epoch(global_epoch_preempt) || sx_xlocked(&pmc_sx)); 1832 KASSERT(PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)), 1833 ("[pmc,%d] non-sampling PMC (%p) desires mapping information", 1834 __LINE__, (void *) pm)); 1835 1836 po = pm->pm_owner; 1837 1838 if (po->po_flags & PMC_PO_INITIAL_MAPPINGS_DONE) 1839 return; 1840 if (PMC_TO_MODE(pm) == PMC_MODE_SS) 1841 pmc_process_allproc(pm); 1842 /* 1843 * Log the current set of kernel modules. 1844 */ 1845 kmbase = linker_hwpmc_list_objects(); 1846 for (km = kmbase; km->pm_file != NULL; km++) { 1847 PMCDBG2(LOG,REG,1,"%s %p", (char *) km->pm_file, 1848 (void *) km->pm_address); 1849 pmclog_process_map_in(po, (pid_t) -1, km->pm_address, 1850 km->pm_file); 1851 } 1852 free(kmbase, M_LINKER); 1853 1854 po->po_flags |= PMC_PO_INITIAL_MAPPINGS_DONE; 1855 } 1856 1857 /* 1858 * Log the mappings for a single process. 1859 */ 1860 1861 static void 1862 pmc_log_process_mappings(struct pmc_owner *po, struct proc *p) 1863 { 1864 vm_map_t map; 1865 struct vnode *vp; 1866 struct vmspace *vm; 1867 vm_map_entry_t entry; 1868 vm_offset_t last_end; 1869 u_int last_timestamp; 1870 struct vnode *last_vp; 1871 vm_offset_t start_addr; 1872 vm_object_t obj, lobj, tobj; 1873 char *fullpath, *freepath; 1874 1875 last_vp = NULL; 1876 last_end = (vm_offset_t) 0; 1877 fullpath = freepath = NULL; 1878 1879 if ((vm = vmspace_acquire_ref(p)) == NULL) 1880 return; 1881 1882 map = &vm->vm_map; 1883 vm_map_lock_read(map); 1884 1885 for (entry = map->header.next; entry != &map->header; entry = entry->next) { 1886 1887 if (entry == NULL) { 1888 PMCDBG2(LOG,OPS,2, "hwpmc: vm_map entry unexpectedly " 1889 "NULL! pid=%d vm_map=%p\n", p->p_pid, map); 1890 break; 1891 } 1892 1893 /* 1894 * We only care about executable map entries. 1895 */ 1896 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) || 1897 !(entry->protection & VM_PROT_EXECUTE) || 1898 (entry->object.vm_object == NULL)) { 1899 continue; 1900 } 1901 1902 obj = entry->object.vm_object; 1903 VM_OBJECT_RLOCK(obj); 1904 1905 /* 1906 * Walk the backing_object list to find the base 1907 * (non-shadowed) vm_object. 1908 */ 1909 for (lobj = tobj = obj; tobj != NULL; tobj = tobj->backing_object) { 1910 if (tobj != obj) 1911 VM_OBJECT_RLOCK(tobj); 1912 if (lobj != obj) 1913 VM_OBJECT_RUNLOCK(lobj); 1914 lobj = tobj; 1915 } 1916 1917 /* 1918 * At this point lobj is the base vm_object and it is locked. 1919 */ 1920 if (lobj == NULL) { 1921 PMCDBG3(LOG,OPS,2, "hwpmc: lobj unexpectedly NULL! pid=%d " 1922 "vm_map=%p vm_obj=%p\n", p->p_pid, map, obj); 1923 VM_OBJECT_RUNLOCK(obj); 1924 continue; 1925 } 1926 1927 vp = vm_object_vnode(lobj); 1928 if (vp == NULL) { 1929 if (lobj != obj) 1930 VM_OBJECT_RUNLOCK(lobj); 1931 VM_OBJECT_RUNLOCK(obj); 1932 continue; 1933 } 1934 1935 /* 1936 * Skip contiguous regions that point to the same 1937 * vnode, so we don't emit redundant MAP-IN 1938 * directives. 1939 */ 1940 if (entry->start == last_end && vp == last_vp) { 1941 last_end = entry->end; 1942 if (lobj != obj) 1943 VM_OBJECT_RUNLOCK(lobj); 1944 VM_OBJECT_RUNLOCK(obj); 1945 continue; 1946 } 1947 1948 /* 1949 * We don't want to keep the proc's vm_map or this 1950 * vm_object locked while we walk the pathname, since 1951 * vn_fullpath() can sleep. However, if we drop the 1952 * lock, it's possible for concurrent activity to 1953 * modify the vm_map list. To protect against this, 1954 * we save the vm_map timestamp before we release the 1955 * lock, and check it after we reacquire the lock 1956 * below. 1957 */ 1958 start_addr = entry->start; 1959 last_end = entry->end; 1960 last_timestamp = map->timestamp; 1961 vm_map_unlock_read(map); 1962 1963 vref(vp); 1964 if (lobj != obj) 1965 VM_OBJECT_RUNLOCK(lobj); 1966 1967 VM_OBJECT_RUNLOCK(obj); 1968 1969 freepath = NULL; 1970 pmc_getfilename(vp, &fullpath, &freepath); 1971 last_vp = vp; 1972 1973 vrele(vp); 1974 1975 vp = NULL; 1976 pmclog_process_map_in(po, p->p_pid, start_addr, fullpath); 1977 if (freepath) 1978 free(freepath, M_TEMP); 1979 1980 vm_map_lock_read(map); 1981 1982 /* 1983 * If our saved timestamp doesn't match, this means 1984 * that the vm_map was modified out from under us and 1985 * we can't trust our current "entry" pointer. Do a 1986 * new lookup for this entry. If there is no entry 1987 * for this address range, vm_map_lookup_entry() will 1988 * return the previous one, so we always want to go to 1989 * entry->next on the next loop iteration. 1990 * 1991 * There is an edge condition here that can occur if 1992 * there is no entry at or before this address. In 1993 * this situation, vm_map_lookup_entry returns 1994 * &map->header, which would cause our loop to abort 1995 * without processing the rest of the map. However, 1996 * in practice this will never happen for process 1997 * vm_map. This is because the executable's text 1998 * segment is the first mapping in the proc's address 1999 * space, and this mapping is never removed until the 2000 * process exits, so there will always be a non-header 2001 * entry at or before the requested address for 2002 * vm_map_lookup_entry to return. 2003 */ 2004 if (map->timestamp != last_timestamp) 2005 vm_map_lookup_entry(map, last_end - 1, &entry); 2006 } 2007 2008 vm_map_unlock_read(map); 2009 vmspace_free(vm); 2010 return; 2011 } 2012 2013 /* 2014 * Log mappings for all processes in the system. 2015 */ 2016 2017 static void 2018 pmc_log_all_process_mappings(struct pmc_owner *po) 2019 { 2020 struct proc *p, *top; 2021 2022 sx_assert(&pmc_sx, SX_XLOCKED); 2023 2024 if ((p = pfind(1)) == NULL) 2025 panic("[pmc,%d] Cannot find init", __LINE__); 2026 2027 PROC_UNLOCK(p); 2028 2029 sx_slock(&proctree_lock); 2030 2031 top = p; 2032 2033 for (;;) { 2034 pmc_log_process_mappings(po, p); 2035 if (!LIST_EMPTY(&p->p_children)) 2036 p = LIST_FIRST(&p->p_children); 2037 else for (;;) { 2038 if (p == top) 2039 goto done; 2040 if (LIST_NEXT(p, p_sibling)) { 2041 p = LIST_NEXT(p, p_sibling); 2042 break; 2043 } 2044 p = p->p_pptr; 2045 } 2046 } 2047 done: 2048 sx_sunlock(&proctree_lock); 2049 } 2050 2051 /* 2052 * The 'hook' invoked from the kernel proper 2053 */ 2054 2055 2056 #ifdef HWPMC_DEBUG 2057 const char *pmc_hooknames[] = { 2058 /* these strings correspond to PMC_FN_* in <sys/pmckern.h> */ 2059 "", 2060 "EXEC", 2061 "CSW-IN", 2062 "CSW-OUT", 2063 "SAMPLE", 2064 "UNUSED1", 2065 "UNUSED2", 2066 "MMAP", 2067 "MUNMAP", 2068 "CALLCHAIN-NMI", 2069 "CALLCHAIN-SOFT", 2070 "SOFTSAMPLING", 2071 "THR-CREATE", 2072 "THR-EXIT", 2073 "THR-USERRET", 2074 "THR-CREATE-LOG", 2075 "THR-EXIT-LOG", 2076 "PROC-CREATE-LOG" 2077 }; 2078 #endif 2079 2080 static int 2081 pmc_hook_handler(struct thread *td, int function, void *arg) 2082 { 2083 int cpu; 2084 2085 PMCDBG4(MOD,PMH,1, "hook td=%p func=%d \"%s\" arg=%p", td, function, 2086 pmc_hooknames[function], arg); 2087 2088 switch (function) 2089 { 2090 2091 /* 2092 * Process exec() 2093 */ 2094 2095 case PMC_FN_PROCESS_EXEC: 2096 { 2097 char *fullpath, *freepath; 2098 unsigned int ri; 2099 int is_using_hwpmcs; 2100 struct pmc *pm; 2101 struct proc *p; 2102 struct pmc_owner *po; 2103 struct pmc_process *pp; 2104 struct pmckern_procexec *pk; 2105 2106 sx_assert(&pmc_sx, SX_XLOCKED); 2107 2108 p = td->td_proc; 2109 pmc_getfilename(p->p_textvp, &fullpath, &freepath); 2110 2111 pk = (struct pmckern_procexec *) arg; 2112 2113 PMC_EPOCH_ENTER(); 2114 /* Inform owners of SS mode PMCs of the exec event. */ 2115 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 2116 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 2117 pmclog_process_procexec(po, PMC_ID_INVALID, 2118 p->p_pid, pk->pm_entryaddr, fullpath); 2119 PMC_EPOCH_EXIT(); 2120 2121 PROC_LOCK(p); 2122 is_using_hwpmcs = p->p_flag & P_HWPMC; 2123 PROC_UNLOCK(p); 2124 2125 if (!is_using_hwpmcs) { 2126 if (freepath) 2127 free(freepath, M_TEMP); 2128 break; 2129 } 2130 2131 /* 2132 * PMCs are not inherited across an exec(): remove any 2133 * PMCs that this process is the owner of. 2134 */ 2135 2136 if ((po = pmc_find_owner_descriptor(p)) != NULL) { 2137 pmc_remove_owner(po); 2138 pmc_destroy_owner_descriptor(po); 2139 } 2140 2141 /* 2142 * If the process being exec'ed is not the target of any 2143 * PMC, we are done. 2144 */ 2145 if ((pp = pmc_find_process_descriptor(p, 0)) == NULL) { 2146 if (freepath) 2147 free(freepath, M_TEMP); 2148 break; 2149 } 2150 2151 /* 2152 * Log the exec event to all monitoring owners. Skip 2153 * owners who have already received the event because 2154 * they had system sampling PMCs active. 2155 */ 2156 for (ri = 0; ri < md->pmd_npmc; ri++) 2157 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) { 2158 po = pm->pm_owner; 2159 if (po->po_sscount == 0 && 2160 po->po_flags & PMC_PO_OWNS_LOGFILE) 2161 pmclog_process_procexec(po, pm->pm_id, 2162 p->p_pid, pk->pm_entryaddr, 2163 fullpath); 2164 } 2165 2166 if (freepath) 2167 free(freepath, M_TEMP); 2168 2169 2170 PMCDBG4(PRC,EXC,1, "exec proc=%p (%d, %s) cred-changed=%d", 2171 p, p->p_pid, p->p_comm, pk->pm_credentialschanged); 2172 2173 if (pk->pm_credentialschanged == 0) /* no change */ 2174 break; 2175 2176 /* 2177 * If the newly exec()'ed process has a different credential 2178 * than before, allow it to be the target of a PMC only if 2179 * the PMC's owner has sufficient privilege. 2180 */ 2181 2182 for (ri = 0; ri < md->pmd_npmc; ri++) 2183 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) 2184 if (pmc_can_attach(pm, td->td_proc) != 0) 2185 pmc_detach_one_process(td->td_proc, 2186 pm, PMC_FLAG_NONE); 2187 2188 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= (int) md->pmd_npmc, 2189 ("[pmc,%d] Illegal ref count %d on pp %p", __LINE__, 2190 pp->pp_refcnt, pp)); 2191 2192 /* 2193 * If this process is no longer the target of any 2194 * PMCs, we can remove the process entry and free 2195 * up space. 2196 */ 2197 2198 if (pp->pp_refcnt == 0) { 2199 pmc_remove_process_descriptor(pp); 2200 pmc_destroy_process_descriptor(pp); 2201 break; 2202 } 2203 2204 } 2205 break; 2206 2207 case PMC_FN_CSW_IN: 2208 pmc_process_csw_in(td); 2209 break; 2210 2211 case PMC_FN_CSW_OUT: 2212 pmc_process_csw_out(td); 2213 break; 2214 2215 /* 2216 * Process accumulated PC samples. 2217 * 2218 * This function is expected to be called by hardclock() for 2219 * each CPU that has accumulated PC samples. 2220 * 2221 * This function is to be executed on the CPU whose samples 2222 * are being processed. 2223 */ 2224 case PMC_FN_DO_SAMPLES: 2225 2226 /* 2227 * Clear the cpu specific bit in the CPU mask before 2228 * do the rest of the processing. If the NMI handler 2229 * gets invoked after the "atomic_clear_int()" call 2230 * below but before "pmc_process_samples()" gets 2231 * around to processing the interrupt, then we will 2232 * come back here at the next hardclock() tick (and 2233 * may find nothing to do if "pmc_process_samples()" 2234 * had already processed the interrupt). We don't 2235 * lose the interrupt sample. 2236 */ 2237 DPCPU_SET(pmc_sampled, 0); 2238 cpu = PCPU_GET(cpuid); 2239 pmc_process_samples(cpu, PMC_HR); 2240 pmc_process_samples(cpu, PMC_SR); 2241 pmc_process_samples(cpu, PMC_UR); 2242 break; 2243 2244 case PMC_FN_MMAP: 2245 pmc_process_mmap(td, (struct pmckern_map_in *) arg); 2246 break; 2247 2248 case PMC_FN_MUNMAP: 2249 MPASS(in_epoch(global_epoch_preempt) || sx_xlocked(&pmc_sx)); 2250 pmc_process_munmap(td, (struct pmckern_map_out *) arg); 2251 break; 2252 2253 case PMC_FN_PROC_CREATE_LOG: 2254 pmc_process_proccreate((struct proc *)arg); 2255 break; 2256 2257 case PMC_FN_USER_CALLCHAIN: 2258 /* 2259 * Record a call chain. 2260 */ 2261 KASSERT(td == curthread, ("[pmc,%d] td != curthread", 2262 __LINE__)); 2263 2264 pmc_capture_user_callchain(PCPU_GET(cpuid), PMC_HR, 2265 (struct trapframe *) arg); 2266 2267 KASSERT(td->td_pinned == 1, 2268 ("[pmc,%d] invalid td_pinned value", __LINE__)); 2269 sched_unpin(); /* Can migrate safely now. */ 2270 2271 td->td_pflags &= ~TDP_CALLCHAIN; 2272 break; 2273 2274 case PMC_FN_USER_CALLCHAIN_SOFT: 2275 /* 2276 * Record a call chain. 2277 */ 2278 KASSERT(td == curthread, ("[pmc,%d] td != curthread", 2279 __LINE__)); 2280 2281 cpu = PCPU_GET(cpuid); 2282 pmc_capture_user_callchain(cpu, PMC_SR, 2283 (struct trapframe *) arg); 2284 2285 KASSERT(td->td_pinned == 1, 2286 ("[pmc,%d] invalid td_pinned value", __LINE__)); 2287 2288 sched_unpin(); /* Can migrate safely now. */ 2289 2290 td->td_pflags &= ~TDP_CALLCHAIN; 2291 break; 2292 2293 case PMC_FN_SOFT_SAMPLING: 2294 /* 2295 * Call soft PMC sampling intr. 2296 */ 2297 pmc_soft_intr((struct pmckern_soft *) arg); 2298 break; 2299 2300 case PMC_FN_THR_CREATE: 2301 pmc_process_thread_add(td); 2302 pmc_process_threadcreate(td); 2303 break; 2304 2305 case PMC_FN_THR_CREATE_LOG: 2306 pmc_process_threadcreate(td); 2307 break; 2308 2309 case PMC_FN_THR_EXIT: 2310 KASSERT(td == curthread, ("[pmc,%d] td != curthread", 2311 __LINE__)); 2312 pmc_process_thread_delete(td); 2313 pmc_process_threadexit(td); 2314 break; 2315 case PMC_FN_THR_EXIT_LOG: 2316 pmc_process_threadexit(td); 2317 break; 2318 case PMC_FN_THR_USERRET: 2319 KASSERT(td == curthread, ("[pmc,%d] td != curthread", 2320 __LINE__)); 2321 pmc_process_thread_userret(td); 2322 break; 2323 2324 default: 2325 #ifdef HWPMC_DEBUG 2326 KASSERT(0, ("[pmc,%d] unknown hook %d\n", __LINE__, function)); 2327 #endif 2328 break; 2329 2330 } 2331 2332 return 0; 2333 } 2334 2335 /* 2336 * allocate a 'struct pmc_owner' descriptor in the owner hash table. 2337 */ 2338 2339 static struct pmc_owner * 2340 pmc_allocate_owner_descriptor(struct proc *p) 2341 { 2342 uint32_t hindex; 2343 struct pmc_owner *po; 2344 struct pmc_ownerhash *poh; 2345 2346 hindex = PMC_HASH_PTR(p, pmc_ownerhashmask); 2347 poh = &pmc_ownerhash[hindex]; 2348 2349 /* allocate space for N pointers and one descriptor struct */ 2350 po = malloc(sizeof(struct pmc_owner), M_PMC, M_WAITOK|M_ZERO); 2351 po->po_owner = p; 2352 LIST_INSERT_HEAD(poh, po, po_next); /* insert into hash table */ 2353 2354 TAILQ_INIT(&po->po_logbuffers); 2355 mtx_init(&po->po_mtx, "pmc-owner-mtx", "pmc-per-proc", MTX_SPIN); 2356 2357 PMCDBG4(OWN,ALL,1, "allocate-owner proc=%p (%d, %s) pmc-owner=%p", 2358 p, p->p_pid, p->p_comm, po); 2359 2360 return po; 2361 } 2362 2363 static void 2364 pmc_destroy_owner_descriptor(struct pmc_owner *po) 2365 { 2366 2367 PMCDBG4(OWN,REL,1, "destroy-owner po=%p proc=%p (%d, %s)", 2368 po, po->po_owner, po->po_owner->p_pid, po->po_owner->p_comm); 2369 2370 mtx_destroy(&po->po_mtx); 2371 free(po, M_PMC); 2372 } 2373 2374 /* 2375 * Allocate a thread descriptor from the free pool. 2376 * 2377 * NOTE: This *can* return NULL. 2378 */ 2379 static struct pmc_thread * 2380 pmc_thread_descriptor_pool_alloc(void) 2381 { 2382 struct pmc_thread *pt; 2383 2384 mtx_lock_spin(&pmc_threadfreelist_mtx); 2385 if ((pt = LIST_FIRST(&pmc_threadfreelist)) != NULL) { 2386 LIST_REMOVE(pt, pt_next); 2387 pmc_threadfreelist_entries--; 2388 } 2389 mtx_unlock_spin(&pmc_threadfreelist_mtx); 2390 2391 return (pt); 2392 } 2393 2394 /* 2395 * Add a thread descriptor to the free pool. We use this instead of free() 2396 * to maintain a cache of free entries. Additionally, we can safely call 2397 * this function when we cannot call free(), such as in a critical section. 2398 * 2399 */ 2400 static void 2401 pmc_thread_descriptor_pool_free(struct pmc_thread *pt) 2402 { 2403 2404 if (pt == NULL) 2405 return; 2406 2407 memset(pt, 0, THREADENTRY_SIZE); 2408 mtx_lock_spin(&pmc_threadfreelist_mtx); 2409 LIST_INSERT_HEAD(&pmc_threadfreelist, pt, pt_next); 2410 pmc_threadfreelist_entries++; 2411 if (pmc_threadfreelist_entries > pmc_threadfreelist_max) 2412 GROUPTASK_ENQUEUE(&free_gtask); 2413 mtx_unlock_spin(&pmc_threadfreelist_mtx); 2414 } 2415 2416 /* 2417 * A callout to manage the free list. 2418 */ 2419 static void 2420 pmc_thread_descriptor_pool_free_task(void *arg __unused) 2421 { 2422 struct pmc_thread *pt; 2423 LIST_HEAD(, pmc_thread) tmplist; 2424 int delta; 2425 2426 LIST_INIT(&tmplist); 2427 /* Determine what changes, if any, we need to make. */ 2428 mtx_lock_spin(&pmc_threadfreelist_mtx); 2429 delta = pmc_threadfreelist_entries - pmc_threadfreelist_max; 2430 while (delta > 0 && 2431 (pt = LIST_FIRST(&pmc_threadfreelist)) != NULL) { 2432 delta--; 2433 LIST_REMOVE(pt, pt_next); 2434 LIST_INSERT_HEAD(&tmplist, pt, pt_next); 2435 } 2436 mtx_unlock_spin(&pmc_threadfreelist_mtx); 2437 2438 /* If there are entries to free, free them. */ 2439 while (!LIST_EMPTY(&tmplist)) { 2440 pt = LIST_FIRST(&tmplist); 2441 LIST_REMOVE(pt, pt_next); 2442 free(pt, M_PMC); 2443 } 2444 } 2445 2446 /* 2447 * Drain the thread free pool, freeing all allocations. 2448 */ 2449 static void 2450 pmc_thread_descriptor_pool_drain() 2451 { 2452 struct pmc_thread *pt, *next; 2453 2454 LIST_FOREACH_SAFE(pt, &pmc_threadfreelist, pt_next, next) { 2455 LIST_REMOVE(pt, pt_next); 2456 free(pt, M_PMC); 2457 } 2458 } 2459 2460 /* 2461 * find the descriptor corresponding to thread 'td', adding or removing it 2462 * as specified by 'mode'. 2463 * 2464 * Note that this supports additional mode flags in addition to those 2465 * supported by pmc_find_process_descriptor(): 2466 * PMC_FLAG_NOWAIT: Causes the function to not wait for mallocs. 2467 * This makes it safe to call while holding certain other locks. 2468 */ 2469 2470 static struct pmc_thread * 2471 pmc_find_thread_descriptor(struct pmc_process *pp, struct thread *td, 2472 uint32_t mode) 2473 { 2474 struct pmc_thread *pt = NULL, *ptnew = NULL; 2475 int wait_flag; 2476 2477 KASSERT(td != NULL, ("[pmc,%d] called to add NULL td", __LINE__)); 2478 2479 /* 2480 * Pre-allocate memory in the PMC_FLAG_ALLOCATE case prior to 2481 * acquiring the lock. 2482 */ 2483 if (mode & PMC_FLAG_ALLOCATE) { 2484 if ((ptnew = pmc_thread_descriptor_pool_alloc()) == NULL) { 2485 wait_flag = M_WAITOK; 2486 if ((mode & PMC_FLAG_NOWAIT) || in_epoch(global_epoch_preempt)) 2487 wait_flag = M_NOWAIT; 2488 2489 ptnew = malloc(THREADENTRY_SIZE, M_PMC, 2490 wait_flag|M_ZERO); 2491 } 2492 } 2493 2494 mtx_lock_spin(pp->pp_tdslock); 2495 2496 LIST_FOREACH(pt, &pp->pp_tds, pt_next) 2497 if (pt->pt_td == td) 2498 break; 2499 2500 if ((mode & PMC_FLAG_REMOVE) && pt != NULL) 2501 LIST_REMOVE(pt, pt_next); 2502 2503 if ((mode & PMC_FLAG_ALLOCATE) && pt == NULL && ptnew != NULL) { 2504 pt = ptnew; 2505 ptnew = NULL; 2506 pt->pt_td = td; 2507 LIST_INSERT_HEAD(&pp->pp_tds, pt, pt_next); 2508 } 2509 2510 mtx_unlock_spin(pp->pp_tdslock); 2511 2512 if (ptnew != NULL) { 2513 free(ptnew, M_PMC); 2514 } 2515 2516 return pt; 2517 } 2518 2519 /* 2520 * Try to add thread descriptors for each thread in a process. 2521 */ 2522 2523 static void 2524 pmc_add_thread_descriptors_from_proc(struct proc *p, struct pmc_process *pp) 2525 { 2526 struct thread *curtd; 2527 struct pmc_thread **tdlist; 2528 int i, tdcnt, tdlistsz; 2529 2530 KASSERT(!PROC_LOCKED(p), ("[pmc,%d] proc unexpectedly locked", 2531 __LINE__)); 2532 tdcnt = 32; 2533 restart: 2534 tdlistsz = roundup2(tdcnt, 32); 2535 2536 tdcnt = 0; 2537 tdlist = malloc(sizeof(struct pmc_thread*) * tdlistsz, M_TEMP, M_WAITOK); 2538 2539 PROC_LOCK(p); 2540 FOREACH_THREAD_IN_PROC(p, curtd) 2541 tdcnt++; 2542 if (tdcnt >= tdlistsz) { 2543 PROC_UNLOCK(p); 2544 free(tdlist, M_TEMP); 2545 goto restart; 2546 } 2547 /* 2548 * Try to add each thread to the list without sleeping. If unable, 2549 * add to a queue to retry after dropping the process lock. 2550 */ 2551 tdcnt = 0; 2552 FOREACH_THREAD_IN_PROC(p, curtd) { 2553 tdlist[tdcnt] = pmc_find_thread_descriptor(pp, curtd, 2554 PMC_FLAG_ALLOCATE|PMC_FLAG_NOWAIT); 2555 if (tdlist[tdcnt] == NULL) { 2556 PROC_UNLOCK(p); 2557 for (i = 0; i <= tdcnt; i++) 2558 pmc_thread_descriptor_pool_free(tdlist[i]); 2559 free(tdlist, M_TEMP); 2560 goto restart; 2561 } 2562 tdcnt++; 2563 } 2564 PROC_UNLOCK(p); 2565 free(tdlist, M_TEMP); 2566 } 2567 2568 /* 2569 * find the descriptor corresponding to process 'p', adding or removing it 2570 * as specified by 'mode'. 2571 */ 2572 2573 static struct pmc_process * 2574 pmc_find_process_descriptor(struct proc *p, uint32_t mode) 2575 { 2576 uint32_t hindex; 2577 struct pmc_process *pp, *ppnew; 2578 struct pmc_processhash *pph; 2579 2580 hindex = PMC_HASH_PTR(p, pmc_processhashmask); 2581 pph = &pmc_processhash[hindex]; 2582 2583 ppnew = NULL; 2584 2585 /* 2586 * Pre-allocate memory in the PMC_FLAG_ALLOCATE case since we 2587 * cannot call malloc(9) once we hold a spin lock. 2588 */ 2589 if (mode & PMC_FLAG_ALLOCATE) 2590 ppnew = malloc(sizeof(struct pmc_process) + md->pmd_npmc * 2591 sizeof(struct pmc_targetstate), M_PMC, M_WAITOK|M_ZERO); 2592 2593 mtx_lock_spin(&pmc_processhash_mtx); 2594 LIST_FOREACH(pp, pph, pp_next) 2595 if (pp->pp_proc == p) 2596 break; 2597 2598 if ((mode & PMC_FLAG_REMOVE) && pp != NULL) 2599 LIST_REMOVE(pp, pp_next); 2600 2601 if ((mode & PMC_FLAG_ALLOCATE) && pp == NULL && 2602 ppnew != NULL) { 2603 ppnew->pp_proc = p; 2604 LIST_INIT(&ppnew->pp_tds); 2605 ppnew->pp_tdslock = mtx_pool_find(pmc_mtxpool, ppnew); 2606 LIST_INSERT_HEAD(pph, ppnew, pp_next); 2607 mtx_unlock_spin(&pmc_processhash_mtx); 2608 pp = ppnew; 2609 ppnew = NULL; 2610 2611 /* Add thread descriptors for this process' current threads. */ 2612 pmc_add_thread_descriptors_from_proc(p, pp); 2613 } 2614 else 2615 mtx_unlock_spin(&pmc_processhash_mtx); 2616 2617 if (ppnew != NULL) 2618 free(ppnew, M_PMC); 2619 2620 return pp; 2621 } 2622 2623 /* 2624 * remove a process descriptor from the process hash table. 2625 */ 2626 2627 static void 2628 pmc_remove_process_descriptor(struct pmc_process *pp) 2629 { 2630 KASSERT(pp->pp_refcnt == 0, 2631 ("[pmc,%d] Removing process descriptor %p with count %d", 2632 __LINE__, pp, pp->pp_refcnt)); 2633 2634 mtx_lock_spin(&pmc_processhash_mtx); 2635 LIST_REMOVE(pp, pp_next); 2636 mtx_unlock_spin(&pmc_processhash_mtx); 2637 } 2638 2639 /* 2640 * destroy a process descriptor. 2641 */ 2642 2643 static void 2644 pmc_destroy_process_descriptor(struct pmc_process *pp) 2645 { 2646 struct pmc_thread *pmc_td; 2647 2648 while ((pmc_td = LIST_FIRST(&pp->pp_tds)) != NULL) { 2649 LIST_REMOVE(pmc_td, pt_next); 2650 pmc_thread_descriptor_pool_free(pmc_td); 2651 } 2652 free(pp, M_PMC); 2653 } 2654 2655 2656 /* 2657 * find an owner descriptor corresponding to proc 'p' 2658 */ 2659 2660 static struct pmc_owner * 2661 pmc_find_owner_descriptor(struct proc *p) 2662 { 2663 uint32_t hindex; 2664 struct pmc_owner *po; 2665 struct pmc_ownerhash *poh; 2666 2667 hindex = PMC_HASH_PTR(p, pmc_ownerhashmask); 2668 poh = &pmc_ownerhash[hindex]; 2669 2670 po = NULL; 2671 LIST_FOREACH(po, poh, po_next) 2672 if (po->po_owner == p) 2673 break; 2674 2675 PMCDBG5(OWN,FND,1, "find-owner proc=%p (%d, %s) hindex=0x%x -> " 2676 "pmc-owner=%p", p, p->p_pid, p->p_comm, hindex, po); 2677 2678 return po; 2679 } 2680 2681 /* 2682 * pmc_allocate_pmc_descriptor 2683 * 2684 * Allocate a pmc descriptor and initialize its 2685 * fields. 2686 */ 2687 2688 static struct pmc * 2689 pmc_allocate_pmc_descriptor(void) 2690 { 2691 struct pmc *pmc; 2692 2693 pmc = malloc(sizeof(struct pmc), M_PMC, M_WAITOK|M_ZERO); 2694 pmc->pm_runcount = counter_u64_alloc(M_WAITOK); 2695 pmc->pm_pcpu_state = malloc(sizeof(struct pmc_pcpu_state)*mp_ncpus, M_PMC, M_WAITOK|M_ZERO); 2696 PMCDBG1(PMC,ALL,1, "allocate-pmc -> pmc=%p", pmc); 2697 2698 return pmc; 2699 } 2700 2701 /* 2702 * Destroy a pmc descriptor. 2703 */ 2704 2705 static void 2706 pmc_destroy_pmc_descriptor(struct pmc *pm) 2707 { 2708 2709 KASSERT(pm->pm_state == PMC_STATE_DELETED || 2710 pm->pm_state == PMC_STATE_FREE, 2711 ("[pmc,%d] destroying non-deleted PMC", __LINE__)); 2712 KASSERT(LIST_EMPTY(&pm->pm_targets), 2713 ("[pmc,%d] destroying pmc with targets", __LINE__)); 2714 KASSERT(pm->pm_owner == NULL, 2715 ("[pmc,%d] destroying pmc attached to an owner", __LINE__)); 2716 KASSERT(counter_u64_fetch(pm->pm_runcount) == 0, 2717 ("[pmc,%d] pmc has non-zero run count %ld", __LINE__, 2718 (unsigned long)counter_u64_fetch(pm->pm_runcount))); 2719 2720 counter_u64_free(pm->pm_runcount); 2721 free(pm->pm_pcpu_state, M_PMC); 2722 free(pm, M_PMC); 2723 } 2724 2725 static void 2726 pmc_wait_for_pmc_idle(struct pmc *pm) 2727 { 2728 #ifdef HWPMC_DEBUG 2729 volatile int maxloop; 2730 2731 maxloop = 100 * pmc_cpu_max(); 2732 #endif 2733 /* 2734 * Loop (with a forced context switch) till the PMC's runcount 2735 * comes down to zero. 2736 */ 2737 pmclog_flush(pm->pm_owner, 1); 2738 while (counter_u64_fetch(pm->pm_runcount) > 0) { 2739 pmclog_flush(pm->pm_owner, 1); 2740 #ifdef HWPMC_DEBUG 2741 maxloop--; 2742 KASSERT(maxloop > 0, 2743 ("[pmc,%d] (ri%d, rc%ld) waiting too long for " 2744 "pmc to be free", __LINE__, 2745 PMC_TO_ROWINDEX(pm), (unsigned long)counter_u64_fetch(pm->pm_runcount))); 2746 #endif 2747 pmc_force_context_switch(); 2748 } 2749 } 2750 2751 /* 2752 * This function does the following things: 2753 * 2754 * - detaches the PMC from hardware 2755 * - unlinks all target threads that were attached to it 2756 * - removes the PMC from its owner's list 2757 * - destroys the PMC private mutex 2758 * 2759 * Once this function completes, the given pmc pointer can be freed by 2760 * calling pmc_destroy_pmc_descriptor(). 2761 */ 2762 2763 static void 2764 pmc_release_pmc_descriptor(struct pmc *pm) 2765 { 2766 enum pmc_mode mode; 2767 struct pmc_hw *phw; 2768 u_int adjri, ri, cpu; 2769 struct pmc_owner *po; 2770 struct pmc_binding pb; 2771 struct pmc_process *pp; 2772 struct pmc_classdep *pcd; 2773 struct pmc_target *ptgt, *tmp; 2774 2775 sx_assert(&pmc_sx, SX_XLOCKED); 2776 2777 KASSERT(pm, ("[pmc,%d] null pmc", __LINE__)); 2778 2779 ri = PMC_TO_ROWINDEX(pm); 2780 pcd = pmc_ri_to_classdep(md, ri, &adjri); 2781 mode = PMC_TO_MODE(pm); 2782 2783 PMCDBG3(PMC,REL,1, "release-pmc pmc=%p ri=%d mode=%d", pm, ri, 2784 mode); 2785 2786 /* 2787 * First, we take the PMC off hardware. 2788 */ 2789 cpu = 0; 2790 if (PMC_IS_SYSTEM_MODE(mode)) { 2791 2792 /* 2793 * A system mode PMC runs on a specific CPU. Switch 2794 * to this CPU and turn hardware off. 2795 */ 2796 pmc_save_cpu_binding(&pb); 2797 2798 cpu = PMC_TO_CPU(pm); 2799 2800 pmc_select_cpu(cpu); 2801 2802 /* switch off non-stalled CPUs */ 2803 pm->pm_pcpu_state[cpu].pps_cpustate = 0; 2804 if (pm->pm_state == PMC_STATE_RUNNING && 2805 pm->pm_pcpu_state[cpu].pps_stalled == 0) { 2806 2807 phw = pmc_pcpu[cpu]->pc_hwpmcs[ri]; 2808 2809 KASSERT(phw->phw_pmc == pm, 2810 ("[pmc, %d] pmc ptr ri(%d) hw(%p) pm(%p)", 2811 __LINE__, ri, phw->phw_pmc, pm)); 2812 PMCDBG2(PMC,REL,2, "stopping cpu=%d ri=%d", cpu, ri); 2813 2814 critical_enter(); 2815 pcd->pcd_stop_pmc(cpu, adjri); 2816 critical_exit(); 2817 } 2818 2819 PMCDBG2(PMC,REL,2, "decfg cpu=%d ri=%d", cpu, ri); 2820 2821 critical_enter(); 2822 pcd->pcd_config_pmc(cpu, adjri, NULL); 2823 critical_exit(); 2824 2825 /* adjust the global and process count of SS mode PMCs */ 2826 if (mode == PMC_MODE_SS && pm->pm_state == PMC_STATE_RUNNING) { 2827 po = pm->pm_owner; 2828 po->po_sscount--; 2829 if (po->po_sscount == 0) { 2830 atomic_subtract_rel_int(&pmc_ss_count, 1); 2831 CK_LIST_REMOVE(po, po_ssnext); 2832 epoch_wait_preempt(global_epoch_preempt); 2833 } 2834 } 2835 2836 pm->pm_state = PMC_STATE_DELETED; 2837 2838 pmc_restore_cpu_binding(&pb); 2839 2840 /* 2841 * We could have references to this PMC structure in 2842 * the per-cpu sample queues. Wait for the queue to 2843 * drain. 2844 */ 2845 pmc_wait_for_pmc_idle(pm); 2846 2847 } else if (PMC_IS_VIRTUAL_MODE(mode)) { 2848 2849 /* 2850 * A virtual PMC could be running on multiple CPUs at 2851 * a given instant. 2852 * 2853 * By marking its state as DELETED, we ensure that 2854 * this PMC is never further scheduled on hardware. 2855 * 2856 * Then we wait till all CPUs are done with this PMC. 2857 */ 2858 pm->pm_state = PMC_STATE_DELETED; 2859 2860 2861 /* Wait for the PMCs runcount to come to zero. */ 2862 pmc_wait_for_pmc_idle(pm); 2863 2864 /* 2865 * At this point the PMC is off all CPUs and cannot be 2866 * freshly scheduled onto a CPU. It is now safe to 2867 * unlink all targets from this PMC. If a 2868 * process-record's refcount falls to zero, we remove 2869 * it from the hash table. The module-wide SX lock 2870 * protects us from races. 2871 */ 2872 LIST_FOREACH_SAFE(ptgt, &pm->pm_targets, pt_next, tmp) { 2873 pp = ptgt->pt_process; 2874 pmc_unlink_target_process(pm, pp); /* frees 'ptgt' */ 2875 2876 PMCDBG1(PMC,REL,3, "pp->refcnt=%d", pp->pp_refcnt); 2877 2878 /* 2879 * If the target process record shows that no 2880 * PMCs are attached to it, reclaim its space. 2881 */ 2882 2883 if (pp->pp_refcnt == 0) { 2884 pmc_remove_process_descriptor(pp); 2885 pmc_destroy_process_descriptor(pp); 2886 } 2887 } 2888 2889 cpu = curthread->td_oncpu; /* setup cpu for pmd_release() */ 2890 2891 } 2892 2893 /* 2894 * Release any MD resources 2895 */ 2896 (void) pcd->pcd_release_pmc(cpu, adjri, pm); 2897 2898 /* 2899 * Update row disposition 2900 */ 2901 2902 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) 2903 PMC_UNMARK_ROW_STANDALONE(ri); 2904 else 2905 PMC_UNMARK_ROW_THREAD(ri); 2906 2907 /* unlink from the owner's list */ 2908 if (pm->pm_owner) { 2909 LIST_REMOVE(pm, pm_next); 2910 pm->pm_owner = NULL; 2911 } 2912 } 2913 2914 /* 2915 * Register an owner and a pmc. 2916 */ 2917 2918 static int 2919 pmc_register_owner(struct proc *p, struct pmc *pmc) 2920 { 2921 struct pmc_owner *po; 2922 2923 sx_assert(&pmc_sx, SX_XLOCKED); 2924 2925 if ((po = pmc_find_owner_descriptor(p)) == NULL) 2926 if ((po = pmc_allocate_owner_descriptor(p)) == NULL) 2927 return ENOMEM; 2928 2929 KASSERT(pmc->pm_owner == NULL, 2930 ("[pmc,%d] attempting to own an initialized PMC", __LINE__)); 2931 pmc->pm_owner = po; 2932 2933 LIST_INSERT_HEAD(&po->po_pmcs, pmc, pm_next); 2934 2935 PROC_LOCK(p); 2936 p->p_flag |= P_HWPMC; 2937 PROC_UNLOCK(p); 2938 2939 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 2940 pmclog_process_pmcallocate(pmc); 2941 2942 PMCDBG2(PMC,REG,1, "register-owner pmc-owner=%p pmc=%p", 2943 po, pmc); 2944 2945 return 0; 2946 } 2947 2948 /* 2949 * Return the current row disposition: 2950 * == 0 => FREE 2951 * > 0 => PROCESS MODE 2952 * < 0 => SYSTEM MODE 2953 */ 2954 2955 int 2956 pmc_getrowdisp(int ri) 2957 { 2958 return pmc_pmcdisp[ri]; 2959 } 2960 2961 /* 2962 * Check if a PMC at row index 'ri' can be allocated to the current 2963 * process. 2964 * 2965 * Allocation can fail if: 2966 * - the current process is already being profiled by a PMC at index 'ri', 2967 * attached to it via OP_PMCATTACH. 2968 * - the current process has already allocated a PMC at index 'ri' 2969 * via OP_ALLOCATE. 2970 */ 2971 2972 static int 2973 pmc_can_allocate_rowindex(struct proc *p, unsigned int ri, int cpu) 2974 { 2975 enum pmc_mode mode; 2976 struct pmc *pm; 2977 struct pmc_owner *po; 2978 struct pmc_process *pp; 2979 2980 PMCDBG5(PMC,ALR,1, "can-allocate-rowindex proc=%p (%d, %s) ri=%d " 2981 "cpu=%d", p, p->p_pid, p->p_comm, ri, cpu); 2982 2983 /* 2984 * We shouldn't have already allocated a process-mode PMC at 2985 * row index 'ri'. 2986 * 2987 * We shouldn't have allocated a system-wide PMC on the same 2988 * CPU and same RI. 2989 */ 2990 if ((po = pmc_find_owner_descriptor(p)) != NULL) 2991 LIST_FOREACH(pm, &po->po_pmcs, pm_next) { 2992 if (PMC_TO_ROWINDEX(pm) == ri) { 2993 mode = PMC_TO_MODE(pm); 2994 if (PMC_IS_VIRTUAL_MODE(mode)) 2995 return EEXIST; 2996 if (PMC_IS_SYSTEM_MODE(mode) && 2997 (int) PMC_TO_CPU(pm) == cpu) 2998 return EEXIST; 2999 } 3000 } 3001 3002 /* 3003 * We also shouldn't be the target of any PMC at this index 3004 * since otherwise a PMC_ATTACH to ourselves will fail. 3005 */ 3006 if ((pp = pmc_find_process_descriptor(p, 0)) != NULL) 3007 if (pp->pp_pmcs[ri].pp_pmc) 3008 return EEXIST; 3009 3010 PMCDBG4(PMC,ALR,2, "can-allocate-rowindex proc=%p (%d, %s) ri=%d ok", 3011 p, p->p_pid, p->p_comm, ri); 3012 3013 return 0; 3014 } 3015 3016 /* 3017 * Check if a given PMC at row index 'ri' can be currently used in 3018 * mode 'mode'. 3019 */ 3020 3021 static int 3022 pmc_can_allocate_row(int ri, enum pmc_mode mode) 3023 { 3024 enum pmc_disp disp; 3025 3026 sx_assert(&pmc_sx, SX_XLOCKED); 3027 3028 PMCDBG2(PMC,ALR,1, "can-allocate-row ri=%d mode=%d", ri, mode); 3029 3030 if (PMC_IS_SYSTEM_MODE(mode)) 3031 disp = PMC_DISP_STANDALONE; 3032 else 3033 disp = PMC_DISP_THREAD; 3034 3035 /* 3036 * check disposition for PMC row 'ri': 3037 * 3038 * Expected disposition Row-disposition Result 3039 * 3040 * STANDALONE STANDALONE or FREE proceed 3041 * STANDALONE THREAD fail 3042 * THREAD THREAD or FREE proceed 3043 * THREAD STANDALONE fail 3044 */ 3045 3046 if (!PMC_ROW_DISP_IS_FREE(ri) && 3047 !(disp == PMC_DISP_THREAD && PMC_ROW_DISP_IS_THREAD(ri)) && 3048 !(disp == PMC_DISP_STANDALONE && PMC_ROW_DISP_IS_STANDALONE(ri))) 3049 return EBUSY; 3050 3051 /* 3052 * All OK 3053 */ 3054 3055 PMCDBG2(PMC,ALR,2, "can-allocate-row ri=%d mode=%d ok", ri, mode); 3056 3057 return 0; 3058 3059 } 3060 3061 /* 3062 * Find a PMC descriptor with user handle 'pmcid' for thread 'td'. 3063 */ 3064 3065 static struct pmc * 3066 pmc_find_pmc_descriptor_in_process(struct pmc_owner *po, pmc_id_t pmcid) 3067 { 3068 struct pmc *pm; 3069 3070 KASSERT(PMC_ID_TO_ROWINDEX(pmcid) < md->pmd_npmc, 3071 ("[pmc,%d] Illegal pmc index %d (max %d)", __LINE__, 3072 PMC_ID_TO_ROWINDEX(pmcid), md->pmd_npmc)); 3073 3074 LIST_FOREACH(pm, &po->po_pmcs, pm_next) 3075 if (pm->pm_id == pmcid) 3076 return pm; 3077 3078 return NULL; 3079 } 3080 3081 static int 3082 pmc_find_pmc(pmc_id_t pmcid, struct pmc **pmc) 3083 { 3084 3085 struct pmc *pm, *opm; 3086 struct pmc_owner *po; 3087 struct pmc_process *pp; 3088 3089 PMCDBG1(PMC,FND,1, "find-pmc id=%d", pmcid); 3090 if (PMC_ID_TO_ROWINDEX(pmcid) >= md->pmd_npmc) 3091 return (EINVAL); 3092 3093 if ((po = pmc_find_owner_descriptor(curthread->td_proc)) == NULL) { 3094 /* 3095 * In case of PMC_F_DESCENDANTS child processes we will not find 3096 * the current process in the owners hash list. Find the owner 3097 * process first and from there lookup the po. 3098 */ 3099 if ((pp = pmc_find_process_descriptor(curthread->td_proc, 3100 PMC_FLAG_NONE)) == NULL) { 3101 return ESRCH; 3102 } else { 3103 opm = pp->pp_pmcs[PMC_ID_TO_ROWINDEX(pmcid)].pp_pmc; 3104 if (opm == NULL) 3105 return ESRCH; 3106 if ((opm->pm_flags & (PMC_F_ATTACHED_TO_OWNER| 3107 PMC_F_DESCENDANTS)) != (PMC_F_ATTACHED_TO_OWNER| 3108 PMC_F_DESCENDANTS)) 3109 return ESRCH; 3110 po = opm->pm_owner; 3111 } 3112 } 3113 3114 if ((pm = pmc_find_pmc_descriptor_in_process(po, pmcid)) == NULL) 3115 return EINVAL; 3116 3117 PMCDBG2(PMC,FND,2, "find-pmc id=%d -> pmc=%p", pmcid, pm); 3118 3119 *pmc = pm; 3120 return 0; 3121 } 3122 3123 /* 3124 * Start a PMC. 3125 */ 3126 3127 static int 3128 pmc_start(struct pmc *pm) 3129 { 3130 enum pmc_mode mode; 3131 struct pmc_owner *po; 3132 struct pmc_binding pb; 3133 struct pmc_classdep *pcd; 3134 int adjri, error, cpu, ri; 3135 3136 KASSERT(pm != NULL, 3137 ("[pmc,%d] null pm", __LINE__)); 3138 3139 mode = PMC_TO_MODE(pm); 3140 ri = PMC_TO_ROWINDEX(pm); 3141 pcd = pmc_ri_to_classdep(md, ri, &adjri); 3142 3143 error = 0; 3144 3145 PMCDBG3(PMC,OPS,1, "start pmc=%p mode=%d ri=%d", pm, mode, ri); 3146 3147 po = pm->pm_owner; 3148 3149 /* 3150 * Disallow PMCSTART if a logfile is required but has not been 3151 * configured yet. 3152 */ 3153 if ((pm->pm_flags & PMC_F_NEEDS_LOGFILE) && 3154 (po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) 3155 return (EDOOFUS); /* programming error */ 3156 3157 /* 3158 * If this is a sampling mode PMC, log mapping information for 3159 * the kernel modules that are currently loaded. 3160 */ 3161 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 3162 pmc_log_kernel_mappings(pm); 3163 3164 if (PMC_IS_VIRTUAL_MODE(mode)) { 3165 3166 /* 3167 * If a PMCATTACH has never been done on this PMC, 3168 * attach it to its owner process. 3169 */ 3170 3171 if (LIST_EMPTY(&pm->pm_targets)) 3172 error = (pm->pm_flags & PMC_F_ATTACH_DONE) ? ESRCH : 3173 pmc_attach_process(po->po_owner, pm); 3174 3175 /* 3176 * If the PMC is attached to its owner, then force a context 3177 * switch to ensure that the MD state gets set correctly. 3178 */ 3179 3180 if (error == 0) { 3181 pm->pm_state = PMC_STATE_RUNNING; 3182 if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) 3183 pmc_force_context_switch(); 3184 } 3185 3186 return (error); 3187 } 3188 3189 3190 /* 3191 * A system-wide PMC. 3192 * 3193 * Add the owner to the global list if this is a system-wide 3194 * sampling PMC. 3195 */ 3196 3197 if (mode == PMC_MODE_SS) { 3198 /* 3199 * Log mapping information for all existing processes in the 3200 * system. Subsequent mappings are logged as they happen; 3201 * see pmc_process_mmap(). 3202 */ 3203 if (po->po_logprocmaps == 0) { 3204 pmc_log_all_process_mappings(po); 3205 po->po_logprocmaps = 1; 3206 } 3207 po->po_sscount++; 3208 if (po->po_sscount == 1) { 3209 atomic_add_rel_int(&pmc_ss_count, 1); 3210 CK_LIST_INSERT_HEAD(&pmc_ss_owners, po, po_ssnext); 3211 PMCDBG1(PMC,OPS,1, "po=%p in global list", po); 3212 } 3213 } 3214 3215 /* 3216 * Move to the CPU associated with this 3217 * PMC, and start the hardware. 3218 */ 3219 3220 pmc_save_cpu_binding(&pb); 3221 3222 cpu = PMC_TO_CPU(pm); 3223 3224 if (!pmc_cpu_is_active(cpu)) 3225 return (ENXIO); 3226 3227 pmc_select_cpu(cpu); 3228 3229 /* 3230 * global PMCs are configured at allocation time 3231 * so write out the initial value and start the PMC. 3232 */ 3233 3234 pm->pm_state = PMC_STATE_RUNNING; 3235 3236 critical_enter(); 3237 if ((error = pcd->pcd_write_pmc(cpu, adjri, 3238 PMC_IS_SAMPLING_MODE(mode) ? 3239 pm->pm_sc.pm_reloadcount : 3240 pm->pm_sc.pm_initial)) == 0) { 3241 /* If a sampling mode PMC, reset stalled state. */ 3242 if (PMC_IS_SAMPLING_MODE(mode)) 3243 pm->pm_pcpu_state[cpu].pps_stalled = 0; 3244 3245 /* Indicate that we desire this to run. Start it. */ 3246 pm->pm_pcpu_state[cpu].pps_cpustate = 1; 3247 error = pcd->pcd_start_pmc(cpu, adjri); 3248 } 3249 critical_exit(); 3250 3251 pmc_restore_cpu_binding(&pb); 3252 3253 return (error); 3254 } 3255 3256 /* 3257 * Stop a PMC. 3258 */ 3259 3260 static int 3261 pmc_stop(struct pmc *pm) 3262 { 3263 struct pmc_owner *po; 3264 struct pmc_binding pb; 3265 struct pmc_classdep *pcd; 3266 int adjri, cpu, error, ri; 3267 3268 KASSERT(pm != NULL, ("[pmc,%d] null pmc", __LINE__)); 3269 3270 PMCDBG3(PMC,OPS,1, "stop pmc=%p mode=%d ri=%d", pm, 3271 PMC_TO_MODE(pm), PMC_TO_ROWINDEX(pm)); 3272 3273 pm->pm_state = PMC_STATE_STOPPED; 3274 3275 /* 3276 * If the PMC is a virtual mode one, changing the state to 3277 * non-RUNNING is enough to ensure that the PMC never gets 3278 * scheduled. 3279 * 3280 * If this PMC is current running on a CPU, then it will 3281 * handled correctly at the time its target process is context 3282 * switched out. 3283 */ 3284 3285 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) 3286 return 0; 3287 3288 /* 3289 * A system-mode PMC. Move to the CPU associated with 3290 * this PMC, and stop the hardware. We update the 3291 * 'initial count' so that a subsequent PMCSTART will 3292 * resume counting from the current hardware count. 3293 */ 3294 3295 pmc_save_cpu_binding(&pb); 3296 3297 cpu = PMC_TO_CPU(pm); 3298 3299 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 3300 ("[pmc,%d] illegal cpu=%d", __LINE__, cpu)); 3301 3302 if (!pmc_cpu_is_active(cpu)) 3303 return ENXIO; 3304 3305 pmc_select_cpu(cpu); 3306 3307 ri = PMC_TO_ROWINDEX(pm); 3308 pcd = pmc_ri_to_classdep(md, ri, &adjri); 3309 3310 pm->pm_pcpu_state[cpu].pps_cpustate = 0; 3311 critical_enter(); 3312 if ((error = pcd->pcd_stop_pmc(cpu, adjri)) == 0) 3313 error = pcd->pcd_read_pmc(cpu, adjri, &pm->pm_sc.pm_initial); 3314 critical_exit(); 3315 3316 pmc_restore_cpu_binding(&pb); 3317 3318 po = pm->pm_owner; 3319 3320 /* remove this owner from the global list of SS PMC owners */ 3321 if (PMC_TO_MODE(pm) == PMC_MODE_SS) { 3322 po->po_sscount--; 3323 if (po->po_sscount == 0) { 3324 atomic_subtract_rel_int(&pmc_ss_count, 1); 3325 CK_LIST_REMOVE(po, po_ssnext); 3326 epoch_wait_preempt(global_epoch_preempt); 3327 PMCDBG1(PMC,OPS,2,"po=%p removed from global list", po); 3328 } 3329 } 3330 3331 return (error); 3332 } 3333 3334 static struct pmc_classdep * 3335 pmc_class_to_classdep(enum pmc_class class) 3336 { 3337 int n; 3338 3339 for (n = 0; n < md->pmd_nclass; n++) 3340 if (md->pmd_classdep[n].pcd_class == class) 3341 return (&md->pmd_classdep[n]); 3342 return (NULL); 3343 } 3344 3345 #if defined(HWPMC_DEBUG) && defined(KTR) 3346 static const char *pmc_op_to_name[] = { 3347 #undef __PMC_OP 3348 #define __PMC_OP(N, D) #N , 3349 __PMC_OPS() 3350 NULL 3351 }; 3352 #endif 3353 3354 /* 3355 * The syscall interface 3356 */ 3357 3358 #define PMC_GET_SX_XLOCK(...) do { \ 3359 sx_xlock(&pmc_sx); \ 3360 if (pmc_hook == NULL) { \ 3361 sx_xunlock(&pmc_sx); \ 3362 return __VA_ARGS__; \ 3363 } \ 3364 } while (0) 3365 3366 #define PMC_DOWNGRADE_SX() do { \ 3367 sx_downgrade(&pmc_sx); \ 3368 is_sx_downgraded = 1; \ 3369 } while (0) 3370 3371 static int 3372 pmc_syscall_handler(struct thread *td, void *syscall_args) 3373 { 3374 int error, is_sx_downgraded, op; 3375 struct pmc_syscall_args *c; 3376 void *pmclog_proc_handle; 3377 void *arg; 3378 3379 c = (struct pmc_syscall_args *)syscall_args; 3380 op = c->pmop_code; 3381 arg = c->pmop_data; 3382 /* PMC isn't set up yet */ 3383 if (pmc_hook == NULL) 3384 return (EINVAL); 3385 if (op == PMC_OP_CONFIGURELOG) { 3386 /* 3387 * We cannot create the logging process inside 3388 * pmclog_configure_log() because there is a LOR 3389 * between pmc_sx and process structure locks. 3390 * Instead, pre-create the process and ignite the loop 3391 * if everything is fine, otherwise direct the process 3392 * to exit. 3393 */ 3394 error = pmclog_proc_create(td, &pmclog_proc_handle); 3395 if (error != 0) 3396 goto done_syscall; 3397 } 3398 3399 PMC_GET_SX_XLOCK(ENOSYS); 3400 is_sx_downgraded = 0; 3401 PMCDBG3(MOD,PMS,1, "syscall op=%d \"%s\" arg=%p", op, 3402 pmc_op_to_name[op], arg); 3403 3404 error = 0; 3405 counter_u64_add(pmc_stats.pm_syscalls, 1); 3406 3407 switch (op) { 3408 3409 3410 /* 3411 * Configure a log file. 3412 * 3413 * XXX This OP will be reworked. 3414 */ 3415 3416 case PMC_OP_CONFIGURELOG: 3417 { 3418 struct proc *p; 3419 struct pmc *pm; 3420 struct pmc_owner *po; 3421 struct pmc_op_configurelog cl; 3422 3423 if ((error = copyin(arg, &cl, sizeof(cl))) != 0) { 3424 pmclog_proc_ignite(pmclog_proc_handle, NULL); 3425 break; 3426 } 3427 3428 /* mark this process as owning a log file */ 3429 p = td->td_proc; 3430 if ((po = pmc_find_owner_descriptor(p)) == NULL) 3431 if ((po = pmc_allocate_owner_descriptor(p)) == NULL) { 3432 pmclog_proc_ignite(pmclog_proc_handle, NULL); 3433 error = ENOMEM; 3434 break; 3435 } 3436 3437 /* 3438 * If a valid fd was passed in, try to configure that, 3439 * otherwise if 'fd' was less than zero and there was 3440 * a log file configured, flush its buffers and 3441 * de-configure it. 3442 */ 3443 if (cl.pm_logfd >= 0) { 3444 error = pmclog_configure_log(md, po, cl.pm_logfd); 3445 pmclog_proc_ignite(pmclog_proc_handle, error == 0 ? 3446 po : NULL); 3447 } else if (po->po_flags & PMC_PO_OWNS_LOGFILE) { 3448 pmclog_proc_ignite(pmclog_proc_handle, NULL); 3449 error = pmclog_close(po); 3450 if (error == 0) { 3451 LIST_FOREACH(pm, &po->po_pmcs, pm_next) 3452 if (pm->pm_flags & PMC_F_NEEDS_LOGFILE && 3453 pm->pm_state == PMC_STATE_RUNNING) 3454 pmc_stop(pm); 3455 error = pmclog_deconfigure_log(po); 3456 } 3457 } else { 3458 pmclog_proc_ignite(pmclog_proc_handle, NULL); 3459 error = EINVAL; 3460 } 3461 } 3462 break; 3463 3464 /* 3465 * Flush a log file. 3466 */ 3467 3468 case PMC_OP_FLUSHLOG: 3469 { 3470 struct pmc_owner *po; 3471 3472 sx_assert(&pmc_sx, SX_XLOCKED); 3473 3474 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 3475 error = EINVAL; 3476 break; 3477 } 3478 3479 error = pmclog_flush(po, 0); 3480 } 3481 break; 3482 3483 /* 3484 * Close a log file. 3485 */ 3486 3487 case PMC_OP_CLOSELOG: 3488 { 3489 struct pmc_owner *po; 3490 3491 sx_assert(&pmc_sx, SX_XLOCKED); 3492 3493 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 3494 error = EINVAL; 3495 break; 3496 } 3497 3498 error = pmclog_close(po); 3499 } 3500 break; 3501 3502 /* 3503 * Retrieve hardware configuration. 3504 */ 3505 3506 case PMC_OP_GETCPUINFO: /* CPU information */ 3507 { 3508 struct pmc_op_getcpuinfo gci; 3509 struct pmc_classinfo *pci; 3510 struct pmc_classdep *pcd; 3511 int cl; 3512 3513 gci.pm_cputype = md->pmd_cputype; 3514 gci.pm_ncpu = pmc_cpu_max(); 3515 gci.pm_npmc = md->pmd_npmc; 3516 gci.pm_nclass = md->pmd_nclass; 3517 pci = gci.pm_classes; 3518 pcd = md->pmd_classdep; 3519 for (cl = 0; cl < md->pmd_nclass; cl++, pci++, pcd++) { 3520 pci->pm_caps = pcd->pcd_caps; 3521 pci->pm_class = pcd->pcd_class; 3522 pci->pm_width = pcd->pcd_width; 3523 pci->pm_num = pcd->pcd_num; 3524 } 3525 error = copyout(&gci, arg, sizeof(gci)); 3526 } 3527 break; 3528 3529 /* 3530 * Retrieve soft events list. 3531 */ 3532 case PMC_OP_GETDYNEVENTINFO: 3533 { 3534 enum pmc_class cl; 3535 enum pmc_event ev; 3536 struct pmc_op_getdyneventinfo *gei; 3537 struct pmc_dyn_event_descr dev; 3538 struct pmc_soft *ps; 3539 uint32_t nevent; 3540 3541 sx_assert(&pmc_sx, SX_LOCKED); 3542 3543 gei = (struct pmc_op_getdyneventinfo *) arg; 3544 3545 if ((error = copyin(&gei->pm_class, &cl, sizeof(cl))) != 0) 3546 break; 3547 3548 /* Only SOFT class is dynamic. */ 3549 if (cl != PMC_CLASS_SOFT) { 3550 error = EINVAL; 3551 break; 3552 } 3553 3554 nevent = 0; 3555 for (ev = PMC_EV_SOFT_FIRST; (int)ev <= PMC_EV_SOFT_LAST; ev++) { 3556 ps = pmc_soft_ev_acquire(ev); 3557 if (ps == NULL) 3558 continue; 3559 bcopy(&ps->ps_ev, &dev, sizeof(dev)); 3560 pmc_soft_ev_release(ps); 3561 3562 error = copyout(&dev, 3563 &gei->pm_events[nevent], 3564 sizeof(struct pmc_dyn_event_descr)); 3565 if (error != 0) 3566 break; 3567 nevent++; 3568 } 3569 if (error != 0) 3570 break; 3571 3572 error = copyout(&nevent, &gei->pm_nevent, 3573 sizeof(nevent)); 3574 } 3575 break; 3576 3577 /* 3578 * Get module statistics 3579 */ 3580 3581 case PMC_OP_GETDRIVERSTATS: 3582 { 3583 struct pmc_op_getdriverstats gms; 3584 #define CFETCH(a, b, field) a.field = counter_u64_fetch(b.field) 3585 CFETCH(gms, pmc_stats, pm_intr_ignored); 3586 CFETCH(gms, pmc_stats, pm_intr_processed); 3587 CFETCH(gms, pmc_stats, pm_intr_bufferfull); 3588 CFETCH(gms, pmc_stats, pm_syscalls); 3589 CFETCH(gms, pmc_stats, pm_syscall_errors); 3590 CFETCH(gms, pmc_stats, pm_buffer_requests); 3591 CFETCH(gms, pmc_stats, pm_buffer_requests_failed); 3592 CFETCH(gms, pmc_stats, pm_log_sweeps); 3593 #undef CFETCH 3594 error = copyout(&gms, arg, sizeof(gms)); 3595 } 3596 break; 3597 3598 3599 /* 3600 * Retrieve module version number 3601 */ 3602 3603 case PMC_OP_GETMODULEVERSION: 3604 { 3605 uint32_t cv, modv; 3606 3607 /* retrieve the client's idea of the ABI version */ 3608 if ((error = copyin(arg, &cv, sizeof(uint32_t))) != 0) 3609 break; 3610 /* don't service clients newer than our driver */ 3611 modv = PMC_VERSION; 3612 if ((cv & 0xFFFF0000) > (modv & 0xFFFF0000)) { 3613 error = EPROGMISMATCH; 3614 break; 3615 } 3616 error = copyout(&modv, arg, sizeof(int)); 3617 } 3618 break; 3619 3620 3621 /* 3622 * Retrieve the state of all the PMCs on a given 3623 * CPU. 3624 */ 3625 3626 case PMC_OP_GETPMCINFO: 3627 { 3628 int ari; 3629 struct pmc *pm; 3630 size_t pmcinfo_size; 3631 uint32_t cpu, n, npmc; 3632 struct pmc_owner *po; 3633 struct pmc_binding pb; 3634 struct pmc_classdep *pcd; 3635 struct pmc_info *p, *pmcinfo; 3636 struct pmc_op_getpmcinfo *gpi; 3637 3638 PMC_DOWNGRADE_SX(); 3639 3640 gpi = (struct pmc_op_getpmcinfo *) arg; 3641 3642 if ((error = copyin(&gpi->pm_cpu, &cpu, sizeof(cpu))) != 0) 3643 break; 3644 3645 if (cpu >= pmc_cpu_max()) { 3646 error = EINVAL; 3647 break; 3648 } 3649 3650 if (!pmc_cpu_is_active(cpu)) { 3651 error = ENXIO; 3652 break; 3653 } 3654 3655 /* switch to CPU 'cpu' */ 3656 pmc_save_cpu_binding(&pb); 3657 pmc_select_cpu(cpu); 3658 3659 npmc = md->pmd_npmc; 3660 3661 pmcinfo_size = npmc * sizeof(struct pmc_info); 3662 pmcinfo = malloc(pmcinfo_size, M_PMC, M_WAITOK); 3663 3664 p = pmcinfo; 3665 3666 for (n = 0; n < md->pmd_npmc; n++, p++) { 3667 3668 pcd = pmc_ri_to_classdep(md, n, &ari); 3669 3670 KASSERT(pcd != NULL, 3671 ("[pmc,%d] null pcd ri=%d", __LINE__, n)); 3672 3673 if ((error = pcd->pcd_describe(cpu, ari, p, &pm)) != 0) 3674 break; 3675 3676 if (PMC_ROW_DISP_IS_STANDALONE(n)) 3677 p->pm_rowdisp = PMC_DISP_STANDALONE; 3678 else if (PMC_ROW_DISP_IS_THREAD(n)) 3679 p->pm_rowdisp = PMC_DISP_THREAD; 3680 else 3681 p->pm_rowdisp = PMC_DISP_FREE; 3682 3683 p->pm_ownerpid = -1; 3684 3685 if (pm == NULL) /* no PMC associated */ 3686 continue; 3687 3688 po = pm->pm_owner; 3689 3690 KASSERT(po->po_owner != NULL, 3691 ("[pmc,%d] pmc_owner had a null proc pointer", 3692 __LINE__)); 3693 3694 p->pm_ownerpid = po->po_owner->p_pid; 3695 p->pm_mode = PMC_TO_MODE(pm); 3696 p->pm_event = pm->pm_event; 3697 p->pm_flags = pm->pm_flags; 3698 3699 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 3700 p->pm_reloadcount = 3701 pm->pm_sc.pm_reloadcount; 3702 } 3703 3704 pmc_restore_cpu_binding(&pb); 3705 3706 /* now copy out the PMC info collected */ 3707 if (error == 0) 3708 error = copyout(pmcinfo, &gpi->pm_pmcs, pmcinfo_size); 3709 3710 free(pmcinfo, M_PMC); 3711 } 3712 break; 3713 3714 3715 /* 3716 * Set the administrative state of a PMC. I.e. whether 3717 * the PMC is to be used or not. 3718 */ 3719 3720 case PMC_OP_PMCADMIN: 3721 { 3722 int cpu, ri; 3723 enum pmc_state request; 3724 struct pmc_cpu *pc; 3725 struct pmc_hw *phw; 3726 struct pmc_op_pmcadmin pma; 3727 struct pmc_binding pb; 3728 3729 sx_assert(&pmc_sx, SX_XLOCKED); 3730 3731 KASSERT(td == curthread, 3732 ("[pmc,%d] td != curthread", __LINE__)); 3733 3734 error = priv_check(td, PRIV_PMC_MANAGE); 3735 if (error) 3736 break; 3737 3738 if ((error = copyin(arg, &pma, sizeof(pma))) != 0) 3739 break; 3740 3741 cpu = pma.pm_cpu; 3742 3743 if (cpu < 0 || cpu >= (int) pmc_cpu_max()) { 3744 error = EINVAL; 3745 break; 3746 } 3747 3748 if (!pmc_cpu_is_active(cpu)) { 3749 error = ENXIO; 3750 break; 3751 } 3752 3753 request = pma.pm_state; 3754 3755 if (request != PMC_STATE_DISABLED && 3756 request != PMC_STATE_FREE) { 3757 error = EINVAL; 3758 break; 3759 } 3760 3761 ri = pma.pm_pmc; /* pmc id == row index */ 3762 if (ri < 0 || ri >= (int) md->pmd_npmc) { 3763 error = EINVAL; 3764 break; 3765 } 3766 3767 /* 3768 * We can't disable a PMC with a row-index allocated 3769 * for process virtual PMCs. 3770 */ 3771 3772 if (PMC_ROW_DISP_IS_THREAD(ri) && 3773 request == PMC_STATE_DISABLED) { 3774 error = EBUSY; 3775 break; 3776 } 3777 3778 /* 3779 * otherwise, this PMC on this CPU is either free or 3780 * in system-wide mode. 3781 */ 3782 3783 pmc_save_cpu_binding(&pb); 3784 pmc_select_cpu(cpu); 3785 3786 pc = pmc_pcpu[cpu]; 3787 phw = pc->pc_hwpmcs[ri]; 3788 3789 /* 3790 * XXX do we need some kind of 'forced' disable? 3791 */ 3792 3793 if (phw->phw_pmc == NULL) { 3794 if (request == PMC_STATE_DISABLED && 3795 (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED)) { 3796 phw->phw_state &= ~PMC_PHW_FLAG_IS_ENABLED; 3797 PMC_MARK_ROW_STANDALONE(ri); 3798 } else if (request == PMC_STATE_FREE && 3799 (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0) { 3800 phw->phw_state |= PMC_PHW_FLAG_IS_ENABLED; 3801 PMC_UNMARK_ROW_STANDALONE(ri); 3802 } 3803 /* other cases are a no-op */ 3804 } else 3805 error = EBUSY; 3806 3807 pmc_restore_cpu_binding(&pb); 3808 } 3809 break; 3810 3811 3812 /* 3813 * Allocate a PMC. 3814 */ 3815 3816 case PMC_OP_PMCALLOCATE: 3817 { 3818 int adjri, n; 3819 u_int cpu; 3820 uint32_t caps; 3821 struct pmc *pmc; 3822 enum pmc_mode mode; 3823 struct pmc_hw *phw; 3824 struct pmc_binding pb; 3825 struct pmc_classdep *pcd; 3826 struct pmc_op_pmcallocate pa; 3827 3828 if ((error = copyin(arg, &pa, sizeof(pa))) != 0) 3829 break; 3830 3831 caps = pa.pm_caps; 3832 mode = pa.pm_mode; 3833 cpu = pa.pm_cpu; 3834 3835 if ((mode != PMC_MODE_SS && mode != PMC_MODE_SC && 3836 mode != PMC_MODE_TS && mode != PMC_MODE_TC) || 3837 (cpu != (u_int) PMC_CPU_ANY && cpu >= pmc_cpu_max())) { 3838 error = EINVAL; 3839 break; 3840 } 3841 3842 /* 3843 * Virtual PMCs should only ask for a default CPU. 3844 * System mode PMCs need to specify a non-default CPU. 3845 */ 3846 3847 if ((PMC_IS_VIRTUAL_MODE(mode) && cpu != (u_int) PMC_CPU_ANY) || 3848 (PMC_IS_SYSTEM_MODE(mode) && cpu == (u_int) PMC_CPU_ANY)) { 3849 error = EINVAL; 3850 break; 3851 } 3852 3853 /* 3854 * Check that an inactive CPU is not being asked for. 3855 */ 3856 3857 if (PMC_IS_SYSTEM_MODE(mode) && !pmc_cpu_is_active(cpu)) { 3858 error = ENXIO; 3859 break; 3860 } 3861 3862 /* 3863 * Refuse an allocation for a system-wide PMC if this 3864 * process has been jailed, or if this process lacks 3865 * super-user credentials and the sysctl tunable 3866 * 'security.bsd.unprivileged_syspmcs' is zero. 3867 */ 3868 3869 if (PMC_IS_SYSTEM_MODE(mode)) { 3870 if (jailed(curthread->td_ucred)) { 3871 error = EPERM; 3872 break; 3873 } 3874 if (!pmc_unprivileged_syspmcs) { 3875 error = priv_check(curthread, 3876 PRIV_PMC_SYSTEM); 3877 if (error) 3878 break; 3879 } 3880 } 3881 3882 /* 3883 * Look for valid values for 'pm_flags' 3884 */ 3885 3886 if ((pa.pm_flags & ~(PMC_F_DESCENDANTS | PMC_F_LOG_PROCCSW | 3887 PMC_F_LOG_PROCEXIT | PMC_F_CALLCHAIN | 3888 PMC_F_USERCALLCHAIN)) != 0) { 3889 error = EINVAL; 3890 break; 3891 } 3892 3893 /* PMC_F_USERCALLCHAIN is only valid with PMC_F_CALLCHAIN */ 3894 if ((pa.pm_flags & (PMC_F_CALLCHAIN | PMC_F_USERCALLCHAIN)) == 3895 PMC_F_USERCALLCHAIN) { 3896 error = EINVAL; 3897 break; 3898 } 3899 3900 /* PMC_F_USERCALLCHAIN is only valid for sampling mode */ 3901 if (pa.pm_flags & PMC_F_USERCALLCHAIN && 3902 mode != PMC_MODE_TS && mode != PMC_MODE_SS) { 3903 error = EINVAL; 3904 break; 3905 } 3906 3907 /* process logging options are not allowed for system PMCs */ 3908 if (PMC_IS_SYSTEM_MODE(mode) && (pa.pm_flags & 3909 (PMC_F_LOG_PROCCSW | PMC_F_LOG_PROCEXIT))) { 3910 error = EINVAL; 3911 break; 3912 } 3913 3914 /* 3915 * All sampling mode PMCs need to be able to interrupt the 3916 * CPU. 3917 */ 3918 if (PMC_IS_SAMPLING_MODE(mode)) 3919 caps |= PMC_CAP_INTERRUPT; 3920 3921 /* A valid class specifier should have been passed in. */ 3922 pcd = pmc_class_to_classdep(pa.pm_class); 3923 if (pcd == NULL) { 3924 error = EINVAL; 3925 break; 3926 } 3927 3928 /* The requested PMC capabilities should be feasible. */ 3929 if ((pcd->pcd_caps & caps) != caps) { 3930 error = EOPNOTSUPP; 3931 break; 3932 } 3933 3934 PMCDBG4(PMC,ALL,2, "event=%d caps=0x%x mode=%d cpu=%d", 3935 pa.pm_ev, caps, mode, cpu); 3936 3937 pmc = pmc_allocate_pmc_descriptor(); 3938 pmc->pm_id = PMC_ID_MAKE_ID(cpu,pa.pm_mode,pa.pm_class, 3939 PMC_ID_INVALID); 3940 pmc->pm_event = pa.pm_ev; 3941 pmc->pm_state = PMC_STATE_FREE; 3942 pmc->pm_caps = caps; 3943 pmc->pm_flags = pa.pm_flags; 3944 3945 /* XXX set lower bound on sampling for process counters */ 3946 if (PMC_IS_SAMPLING_MODE(mode)) { 3947 /* 3948 * Don't permit requested sample rate to be less than 1000 3949 */ 3950 if (pa.pm_count < 1000) 3951 log(LOG_WARNING, 3952 "pmcallocate: passed sample rate %ju - setting to 1000\n", 3953 (uintmax_t)pa.pm_count); 3954 pmc->pm_sc.pm_reloadcount = MAX(1000, pa.pm_count); 3955 } else 3956 pmc->pm_sc.pm_initial = pa.pm_count; 3957 3958 /* switch thread to CPU 'cpu' */ 3959 pmc_save_cpu_binding(&pb); 3960 3961 #define PMC_IS_SHAREABLE_PMC(cpu, n) \ 3962 (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_state & \ 3963 PMC_PHW_FLAG_IS_SHAREABLE) 3964 #define PMC_IS_UNALLOCATED(cpu, n) \ 3965 (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_pmc == NULL) 3966 3967 if (PMC_IS_SYSTEM_MODE(mode)) { 3968 pmc_select_cpu(cpu); 3969 for (n = pcd->pcd_ri; n < (int) md->pmd_npmc; n++) { 3970 pcd = pmc_ri_to_classdep(md, n, &adjri); 3971 if (pmc_can_allocate_row(n, mode) == 0 && 3972 pmc_can_allocate_rowindex( 3973 curthread->td_proc, n, cpu) == 0 && 3974 (PMC_IS_UNALLOCATED(cpu, n) || 3975 PMC_IS_SHAREABLE_PMC(cpu, n)) && 3976 pcd->pcd_allocate_pmc(cpu, adjri, pmc, 3977 &pa) == 0) 3978 break; 3979 } 3980 } else { 3981 /* Process virtual mode */ 3982 for (n = pcd->pcd_ri; n < (int) md->pmd_npmc; n++) { 3983 pcd = pmc_ri_to_classdep(md, n, &adjri); 3984 if (pmc_can_allocate_row(n, mode) == 0 && 3985 pmc_can_allocate_rowindex( 3986 curthread->td_proc, n, 3987 PMC_CPU_ANY) == 0 && 3988 pcd->pcd_allocate_pmc(curthread->td_oncpu, 3989 adjri, pmc, &pa) == 0) 3990 break; 3991 } 3992 } 3993 3994 #undef PMC_IS_UNALLOCATED 3995 #undef PMC_IS_SHAREABLE_PMC 3996 3997 pmc_restore_cpu_binding(&pb); 3998 3999 if (n == (int) md->pmd_npmc) { 4000 pmc_destroy_pmc_descriptor(pmc); 4001 pmc = NULL; 4002 error = EINVAL; 4003 break; 4004 } 4005 4006 /* Fill in the correct value in the ID field */ 4007 pmc->pm_id = PMC_ID_MAKE_ID(cpu,mode,pa.pm_class,n); 4008 4009 PMCDBG5(PMC,ALL,2, "ev=%d class=%d mode=%d n=%d -> pmcid=%x", 4010 pmc->pm_event, pa.pm_class, mode, n, pmc->pm_id); 4011 4012 /* Process mode PMCs with logging enabled need log files */ 4013 if (pmc->pm_flags & (PMC_F_LOG_PROCEXIT | PMC_F_LOG_PROCCSW)) 4014 pmc->pm_flags |= PMC_F_NEEDS_LOGFILE; 4015 4016 /* All system mode sampling PMCs require a log file */ 4017 if (PMC_IS_SAMPLING_MODE(mode) && PMC_IS_SYSTEM_MODE(mode)) 4018 pmc->pm_flags |= PMC_F_NEEDS_LOGFILE; 4019 4020 /* 4021 * Configure global pmc's immediately 4022 */ 4023 4024 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pmc))) { 4025 4026 pmc_save_cpu_binding(&pb); 4027 pmc_select_cpu(cpu); 4028 4029 phw = pmc_pcpu[cpu]->pc_hwpmcs[n]; 4030 pcd = pmc_ri_to_classdep(md, n, &adjri); 4031 4032 if ((phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0 || 4033 (error = pcd->pcd_config_pmc(cpu, adjri, pmc)) != 0) { 4034 (void) pcd->pcd_release_pmc(cpu, adjri, pmc); 4035 pmc_destroy_pmc_descriptor(pmc); 4036 pmc = NULL; 4037 pmc_restore_cpu_binding(&pb); 4038 error = EPERM; 4039 break; 4040 } 4041 4042 pmc_restore_cpu_binding(&pb); 4043 } 4044 4045 pmc->pm_state = PMC_STATE_ALLOCATED; 4046 pmc->pm_class = pa.pm_class; 4047 4048 /* 4049 * mark row disposition 4050 */ 4051 4052 if (PMC_IS_SYSTEM_MODE(mode)) 4053 PMC_MARK_ROW_STANDALONE(n); 4054 else 4055 PMC_MARK_ROW_THREAD(n); 4056 4057 /* 4058 * Register this PMC with the current thread as its owner. 4059 */ 4060 4061 if ((error = 4062 pmc_register_owner(curthread->td_proc, pmc)) != 0) { 4063 pmc_release_pmc_descriptor(pmc); 4064 pmc_destroy_pmc_descriptor(pmc); 4065 pmc = NULL; 4066 break; 4067 } 4068 4069 4070 /* 4071 * Return the allocated index. 4072 */ 4073 4074 pa.pm_pmcid = pmc->pm_id; 4075 4076 error = copyout(&pa, arg, sizeof(pa)); 4077 } 4078 break; 4079 4080 4081 /* 4082 * Attach a PMC to a process. 4083 */ 4084 4085 case PMC_OP_PMCATTACH: 4086 { 4087 struct pmc *pm; 4088 struct proc *p; 4089 struct pmc_op_pmcattach a; 4090 4091 sx_assert(&pmc_sx, SX_XLOCKED); 4092 4093 if ((error = copyin(arg, &a, sizeof(a))) != 0) 4094 break; 4095 4096 if (a.pm_pid < 0) { 4097 error = EINVAL; 4098 break; 4099 } else if (a.pm_pid == 0) 4100 a.pm_pid = td->td_proc->p_pid; 4101 4102 if ((error = pmc_find_pmc(a.pm_pmc, &pm)) != 0) 4103 break; 4104 4105 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) { 4106 error = EINVAL; 4107 break; 4108 } 4109 4110 /* PMCs may be (re)attached only when allocated or stopped */ 4111 if (pm->pm_state == PMC_STATE_RUNNING) { 4112 error = EBUSY; 4113 break; 4114 } else if (pm->pm_state != PMC_STATE_ALLOCATED && 4115 pm->pm_state != PMC_STATE_STOPPED) { 4116 error = EINVAL; 4117 break; 4118 } 4119 4120 /* lookup pid */ 4121 if ((p = pfind(a.pm_pid)) == NULL) { 4122 error = ESRCH; 4123 break; 4124 } 4125 4126 /* 4127 * Ignore processes that are working on exiting. 4128 */ 4129 if (p->p_flag & P_WEXIT) { 4130 error = ESRCH; 4131 PROC_UNLOCK(p); /* pfind() returns a locked process */ 4132 break; 4133 } 4134 4135 /* 4136 * we are allowed to attach a PMC to a process if 4137 * we can debug it. 4138 */ 4139 error = p_candebug(curthread, p); 4140 4141 PROC_UNLOCK(p); 4142 4143 if (error == 0) 4144 error = pmc_attach_process(p, pm); 4145 } 4146 break; 4147 4148 4149 /* 4150 * Detach an attached PMC from a process. 4151 */ 4152 4153 case PMC_OP_PMCDETACH: 4154 { 4155 struct pmc *pm; 4156 struct proc *p; 4157 struct pmc_op_pmcattach a; 4158 4159 if ((error = copyin(arg, &a, sizeof(a))) != 0) 4160 break; 4161 4162 if (a.pm_pid < 0) { 4163 error = EINVAL; 4164 break; 4165 } else if (a.pm_pid == 0) 4166 a.pm_pid = td->td_proc->p_pid; 4167 4168 if ((error = pmc_find_pmc(a.pm_pmc, &pm)) != 0) 4169 break; 4170 4171 if ((p = pfind(a.pm_pid)) == NULL) { 4172 error = ESRCH; 4173 break; 4174 } 4175 4176 /* 4177 * Treat processes that are in the process of exiting 4178 * as if they were not present. 4179 */ 4180 4181 if (p->p_flag & P_WEXIT) 4182 error = ESRCH; 4183 4184 PROC_UNLOCK(p); /* pfind() returns a locked process */ 4185 4186 if (error == 0) 4187 error = pmc_detach_process(p, pm); 4188 } 4189 break; 4190 4191 4192 /* 4193 * Retrieve the MSR number associated with the counter 4194 * 'pmc_id'. This allows processes to directly use RDPMC 4195 * instructions to read their PMCs, without the overhead of a 4196 * system call. 4197 */ 4198 4199 case PMC_OP_PMCGETMSR: 4200 { 4201 int adjri, ri; 4202 struct pmc *pm; 4203 struct pmc_target *pt; 4204 struct pmc_op_getmsr gm; 4205 struct pmc_classdep *pcd; 4206 4207 PMC_DOWNGRADE_SX(); 4208 4209 if ((error = copyin(arg, &gm, sizeof(gm))) != 0) 4210 break; 4211 4212 if ((error = pmc_find_pmc(gm.pm_pmcid, &pm)) != 0) 4213 break; 4214 4215 /* 4216 * The allocated PMC has to be a process virtual PMC, 4217 * i.e., of type MODE_T[CS]. Global PMCs can only be 4218 * read using the PMCREAD operation since they may be 4219 * allocated on a different CPU than the one we could 4220 * be running on at the time of the RDPMC instruction. 4221 * 4222 * The GETMSR operation is not allowed for PMCs that 4223 * are inherited across processes. 4224 */ 4225 4226 if (!PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)) || 4227 (pm->pm_flags & PMC_F_DESCENDANTS)) { 4228 error = EINVAL; 4229 break; 4230 } 4231 4232 /* 4233 * It only makes sense to use a RDPMC (or its 4234 * equivalent instruction on non-x86 architectures) on 4235 * a process that has allocated and attached a PMC to 4236 * itself. Conversely the PMC is only allowed to have 4237 * one process attached to it -- its owner. 4238 */ 4239 4240 if ((pt = LIST_FIRST(&pm->pm_targets)) == NULL || 4241 LIST_NEXT(pt, pt_next) != NULL || 4242 pt->pt_process->pp_proc != pm->pm_owner->po_owner) { 4243 error = EINVAL; 4244 break; 4245 } 4246 4247 ri = PMC_TO_ROWINDEX(pm); 4248 pcd = pmc_ri_to_classdep(md, ri, &adjri); 4249 4250 /* PMC class has no 'GETMSR' support */ 4251 if (pcd->pcd_get_msr == NULL) { 4252 error = ENOSYS; 4253 break; 4254 } 4255 4256 if ((error = (*pcd->pcd_get_msr)(adjri, &gm.pm_msr)) < 0) 4257 break; 4258 4259 if ((error = copyout(&gm, arg, sizeof(gm))) < 0) 4260 break; 4261 4262 /* 4263 * Mark our process as using MSRs. Update machine 4264 * state using a forced context switch. 4265 */ 4266 4267 pt->pt_process->pp_flags |= PMC_PP_ENABLE_MSR_ACCESS; 4268 pmc_force_context_switch(); 4269 4270 } 4271 break; 4272 4273 /* 4274 * Release an allocated PMC 4275 */ 4276 4277 case PMC_OP_PMCRELEASE: 4278 { 4279 pmc_id_t pmcid; 4280 struct pmc *pm; 4281 struct pmc_owner *po; 4282 struct pmc_op_simple sp; 4283 4284 /* 4285 * Find PMC pointer for the named PMC. 4286 * 4287 * Use pmc_release_pmc_descriptor() to switch off the 4288 * PMC, remove all its target threads, and remove the 4289 * PMC from its owner's list. 4290 * 4291 * Remove the owner record if this is the last PMC 4292 * owned. 4293 * 4294 * Free up space. 4295 */ 4296 4297 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 4298 break; 4299 4300 pmcid = sp.pm_pmcid; 4301 4302 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 4303 break; 4304 4305 po = pm->pm_owner; 4306 pmc_release_pmc_descriptor(pm); 4307 pmc_maybe_remove_owner(po); 4308 pmc_destroy_pmc_descriptor(pm); 4309 } 4310 break; 4311 4312 4313 /* 4314 * Read and/or write a PMC. 4315 */ 4316 4317 case PMC_OP_PMCRW: 4318 { 4319 int adjri; 4320 struct pmc *pm; 4321 uint32_t cpu, ri; 4322 pmc_value_t oldvalue; 4323 struct pmc_binding pb; 4324 struct pmc_op_pmcrw prw; 4325 struct pmc_classdep *pcd; 4326 struct pmc_op_pmcrw *pprw; 4327 4328 PMC_DOWNGRADE_SX(); 4329 4330 if ((error = copyin(arg, &prw, sizeof(prw))) != 0) 4331 break; 4332 4333 ri = 0; 4334 PMCDBG2(PMC,OPS,1, "rw id=%d flags=0x%x", prw.pm_pmcid, 4335 prw.pm_flags); 4336 4337 /* must have at least one flag set */ 4338 if ((prw.pm_flags & (PMC_F_OLDVALUE|PMC_F_NEWVALUE)) == 0) { 4339 error = EINVAL; 4340 break; 4341 } 4342 4343 /* locate pmc descriptor */ 4344 if ((error = pmc_find_pmc(prw.pm_pmcid, &pm)) != 0) 4345 break; 4346 4347 /* Can't read a PMC that hasn't been started. */ 4348 if (pm->pm_state != PMC_STATE_ALLOCATED && 4349 pm->pm_state != PMC_STATE_STOPPED && 4350 pm->pm_state != PMC_STATE_RUNNING) { 4351 error = EINVAL; 4352 break; 4353 } 4354 4355 /* writing a new value is allowed only for 'STOPPED' pmcs */ 4356 if (pm->pm_state == PMC_STATE_RUNNING && 4357 (prw.pm_flags & PMC_F_NEWVALUE)) { 4358 error = EBUSY; 4359 break; 4360 } 4361 4362 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) { 4363 4364 /* 4365 * If this PMC is attached to its owner (i.e., 4366 * the process requesting this operation) and 4367 * is running, then attempt to get an 4368 * upto-date reading from hardware for a READ. 4369 * Writes are only allowed when the PMC is 4370 * stopped, so only update the saved value 4371 * field. 4372 * 4373 * If the PMC is not running, or is not 4374 * attached to its owner, read/write to the 4375 * savedvalue field. 4376 */ 4377 4378 ri = PMC_TO_ROWINDEX(pm); 4379 pcd = pmc_ri_to_classdep(md, ri, &adjri); 4380 4381 mtx_pool_lock_spin(pmc_mtxpool, pm); 4382 cpu = curthread->td_oncpu; 4383 4384 if (prw.pm_flags & PMC_F_OLDVALUE) { 4385 if ((pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) && 4386 (pm->pm_state == PMC_STATE_RUNNING)) 4387 error = (*pcd->pcd_read_pmc)(cpu, adjri, 4388 &oldvalue); 4389 else 4390 oldvalue = pm->pm_gv.pm_savedvalue; 4391 } 4392 if (prw.pm_flags & PMC_F_NEWVALUE) 4393 pm->pm_gv.pm_savedvalue = prw.pm_value; 4394 4395 mtx_pool_unlock_spin(pmc_mtxpool, pm); 4396 4397 } else { /* System mode PMCs */ 4398 cpu = PMC_TO_CPU(pm); 4399 ri = PMC_TO_ROWINDEX(pm); 4400 pcd = pmc_ri_to_classdep(md, ri, &adjri); 4401 4402 if (!pmc_cpu_is_active(cpu)) { 4403 error = ENXIO; 4404 break; 4405 } 4406 4407 /* move this thread to CPU 'cpu' */ 4408 pmc_save_cpu_binding(&pb); 4409 pmc_select_cpu(cpu); 4410 4411 critical_enter(); 4412 /* save old value */ 4413 if (prw.pm_flags & PMC_F_OLDVALUE) 4414 if ((error = (*pcd->pcd_read_pmc)(cpu, adjri, 4415 &oldvalue))) 4416 goto error; 4417 /* write out new value */ 4418 if (prw.pm_flags & PMC_F_NEWVALUE) 4419 error = (*pcd->pcd_write_pmc)(cpu, adjri, 4420 prw.pm_value); 4421 error: 4422 critical_exit(); 4423 pmc_restore_cpu_binding(&pb); 4424 if (error) 4425 break; 4426 } 4427 4428 pprw = (struct pmc_op_pmcrw *) arg; 4429 4430 #ifdef HWPMC_DEBUG 4431 if (prw.pm_flags & PMC_F_NEWVALUE) 4432 PMCDBG3(PMC,OPS,2, "rw id=%d new %jx -> old %jx", 4433 ri, prw.pm_value, oldvalue); 4434 else if (prw.pm_flags & PMC_F_OLDVALUE) 4435 PMCDBG2(PMC,OPS,2, "rw id=%d -> old %jx", ri, oldvalue); 4436 #endif 4437 4438 /* return old value if requested */ 4439 if (prw.pm_flags & PMC_F_OLDVALUE) 4440 if ((error = copyout(&oldvalue, &pprw->pm_value, 4441 sizeof(prw.pm_value)))) 4442 break; 4443 4444 } 4445 break; 4446 4447 4448 /* 4449 * Set the sampling rate for a sampling mode PMC and the 4450 * initial count for a counting mode PMC. 4451 */ 4452 4453 case PMC_OP_PMCSETCOUNT: 4454 { 4455 struct pmc *pm; 4456 struct pmc_op_pmcsetcount sc; 4457 4458 PMC_DOWNGRADE_SX(); 4459 4460 if ((error = copyin(arg, &sc, sizeof(sc))) != 0) 4461 break; 4462 4463 if ((error = pmc_find_pmc(sc.pm_pmcid, &pm)) != 0) 4464 break; 4465 4466 if (pm->pm_state == PMC_STATE_RUNNING) { 4467 error = EBUSY; 4468 break; 4469 } 4470 4471 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) { 4472 /* 4473 * Don't permit requested sample rate to be less than 1000 4474 */ 4475 if (sc.pm_count < 1000) 4476 log(LOG_WARNING, 4477 "pmcsetcount: passed sample rate %ju - setting to 1000\n", 4478 (uintmax_t)sc.pm_count); 4479 pm->pm_sc.pm_reloadcount = MAX(1000, sc.pm_count); 4480 } else 4481 pm->pm_sc.pm_initial = sc.pm_count; 4482 } 4483 break; 4484 4485 4486 /* 4487 * Start a PMC. 4488 */ 4489 4490 case PMC_OP_PMCSTART: 4491 { 4492 pmc_id_t pmcid; 4493 struct pmc *pm; 4494 struct pmc_op_simple sp; 4495 4496 sx_assert(&pmc_sx, SX_XLOCKED); 4497 4498 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 4499 break; 4500 4501 pmcid = sp.pm_pmcid; 4502 4503 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 4504 break; 4505 4506 KASSERT(pmcid == pm->pm_id, 4507 ("[pmc,%d] pmcid %x != id %x", __LINE__, 4508 pm->pm_id, pmcid)); 4509 4510 if (pm->pm_state == PMC_STATE_RUNNING) /* already running */ 4511 break; 4512 else if (pm->pm_state != PMC_STATE_STOPPED && 4513 pm->pm_state != PMC_STATE_ALLOCATED) { 4514 error = EINVAL; 4515 break; 4516 } 4517 4518 error = pmc_start(pm); 4519 } 4520 break; 4521 4522 4523 /* 4524 * Stop a PMC. 4525 */ 4526 4527 case PMC_OP_PMCSTOP: 4528 { 4529 pmc_id_t pmcid; 4530 struct pmc *pm; 4531 struct pmc_op_simple sp; 4532 4533 PMC_DOWNGRADE_SX(); 4534 4535 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 4536 break; 4537 4538 pmcid = sp.pm_pmcid; 4539 4540 /* 4541 * Mark the PMC as inactive and invoke the MD stop 4542 * routines if needed. 4543 */ 4544 4545 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 4546 break; 4547 4548 KASSERT(pmcid == pm->pm_id, 4549 ("[pmc,%d] pmc id %x != pmcid %x", __LINE__, 4550 pm->pm_id, pmcid)); 4551 4552 if (pm->pm_state == PMC_STATE_STOPPED) /* already stopped */ 4553 break; 4554 else if (pm->pm_state != PMC_STATE_RUNNING) { 4555 error = EINVAL; 4556 break; 4557 } 4558 4559 error = pmc_stop(pm); 4560 } 4561 break; 4562 4563 4564 /* 4565 * Write a user supplied value to the log file. 4566 */ 4567 4568 case PMC_OP_WRITELOG: 4569 { 4570 struct pmc_op_writelog wl; 4571 struct pmc_owner *po; 4572 4573 PMC_DOWNGRADE_SX(); 4574 4575 if ((error = copyin(arg, &wl, sizeof(wl))) != 0) 4576 break; 4577 4578 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 4579 error = EINVAL; 4580 break; 4581 } 4582 4583 if ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) { 4584 error = EINVAL; 4585 break; 4586 } 4587 4588 error = pmclog_process_userlog(po, &wl); 4589 } 4590 break; 4591 4592 4593 default: 4594 error = EINVAL; 4595 break; 4596 } 4597 4598 if (is_sx_downgraded) 4599 sx_sunlock(&pmc_sx); 4600 else 4601 sx_xunlock(&pmc_sx); 4602 done_syscall: 4603 if (error) 4604 counter_u64_add(pmc_stats.pm_syscall_errors, 1); 4605 4606 return (error); 4607 } 4608 4609 /* 4610 * Helper functions 4611 */ 4612 4613 4614 /* 4615 * Mark the thread as needing callchain capture and post an AST. The 4616 * actual callchain capture will be done in a context where it is safe 4617 * to take page faults. 4618 */ 4619 4620 static void 4621 pmc_post_callchain_callback(void) 4622 { 4623 struct thread *td; 4624 4625 td = curthread; 4626 4627 /* 4628 * If there is multiple PMCs for the same interrupt ignore new post 4629 */ 4630 if (td->td_pflags & TDP_CALLCHAIN) 4631 return; 4632 4633 /* 4634 * Mark this thread as needing callchain capture. 4635 * `td->td_pflags' will be safe to touch because this thread 4636 * was in user space when it was interrupted. 4637 */ 4638 td->td_pflags |= TDP_CALLCHAIN; 4639 4640 /* 4641 * Don't let this thread migrate between CPUs until callchain 4642 * capture completes. 4643 */ 4644 sched_pin(); 4645 4646 return; 4647 } 4648 4649 /* 4650 * Find a free slot in the per-cpu array of samples and capture the 4651 * current callchain there. If a sample was successfully added, a bit 4652 * is set in mask 'pmc_cpumask' denoting that the DO_SAMPLES hook 4653 * needs to be invoked from the clock handler. 4654 * 4655 * This function is meant to be called from an NMI handler. It cannot 4656 * use any of the locking primitives supplied by the OS. 4657 */ 4658 4659 static int 4660 pmc_add_sample(int ring, struct pmc *pm, struct trapframe *tf) 4661 { 4662 int error, cpu, callchaindepth, inuserspace; 4663 struct thread *td; 4664 struct pmc_sample *ps; 4665 struct pmc_samplebuffer *psb; 4666 4667 error = 0; 4668 4669 /* 4670 * Allocate space for a sample buffer. 4671 */ 4672 cpu = curcpu; 4673 psb = pmc_pcpu[cpu]->pc_sb[ring]; 4674 inuserspace = TRAPF_USERMODE(tf); 4675 ps = psb->ps_write; 4676 if (ps->ps_nsamples == PMC_SAMPLE_INUSE) { 4677 counter_u64_add(ps->ps_pmc->pm_runcount, -1); 4678 counter_u64_add(pmc_stats.pm_overwrites, 1); 4679 ps->ps_nsamples = 0; 4680 } else if (ps->ps_nsamples) { /* in use, reader hasn't caught up */ 4681 pm->pm_pcpu_state[cpu].pps_stalled = 1; 4682 counter_u64_add(pmc_stats.pm_intr_bufferfull, 1); 4683 PMCDBG6(SAM,INT,1,"(spc) cpu=%d pm=%p tf=%p um=%d wr=%d rd=%d", 4684 cpu, pm, (void *) tf, inuserspace, 4685 (int) (psb->ps_write - psb->ps_samples), 4686 (int) (psb->ps_read - psb->ps_samples)); 4687 callchaindepth = 1; 4688 error = ENOMEM; 4689 goto done; 4690 } 4691 4692 /* Fill in entry. */ 4693 PMCDBG6(SAM,INT,1,"cpu=%d pm=%p tf=%p um=%d wr=%d rd=%d", cpu, pm, 4694 (void *) tf, inuserspace, 4695 (int) (psb->ps_write - psb->ps_samples), 4696 (int) (psb->ps_read - psb->ps_samples)); 4697 4698 KASSERT(counter_u64_fetch(pm->pm_runcount) >= 0, 4699 ("[pmc,%d] pm=%p runcount %ld", __LINE__, (void *) pm, 4700 (unsigned long)counter_u64_fetch(pm->pm_runcount))); 4701 4702 counter_u64_add(pm->pm_runcount, 1); /* hold onto PMC */ 4703 4704 td = curthread; 4705 ps->ps_pmc = pm; 4706 ps->ps_td = td; 4707 ps->ps_pid = td->td_proc->p_pid; 4708 ps->ps_tid = td->td_tid; 4709 ps->ps_tsc = pmc_rdtsc(); 4710 4711 ps->ps_cpu = cpu; 4712 ps->ps_flags = inuserspace ? PMC_CC_F_USERSPACE : 0; 4713 4714 callchaindepth = (pm->pm_flags & PMC_F_CALLCHAIN) ? 4715 pmc_callchaindepth : 1; 4716 4717 if (callchaindepth == 1) 4718 ps->ps_pc[0] = PMC_TRAPFRAME_TO_PC(tf); 4719 else { 4720 /* 4721 * Kernel stack traversals can be done immediately, 4722 * while we defer to an AST for user space traversals. 4723 */ 4724 if (!inuserspace) { 4725 callchaindepth = 4726 pmc_save_kernel_callchain(ps->ps_pc, 4727 callchaindepth, tf); 4728 } else { 4729 pmc_post_callchain_callback(); 4730 callchaindepth = PMC_SAMPLE_INUSE; 4731 } 4732 } 4733 4734 ps->ps_nsamples = callchaindepth; /* mark entry as in use */ 4735 if (ring == PMC_UR) { 4736 ps->ps_nsamples_actual = callchaindepth; /* mark entry as in use */ 4737 ps->ps_nsamples = PMC_SAMPLE_INUSE; 4738 } else 4739 ps->ps_nsamples = callchaindepth; /* mark entry as in use */ 4740 /* increment write pointer, modulo ring buffer size */ 4741 ps++; 4742 if (ps == psb->ps_fence) 4743 psb->ps_write = psb->ps_samples; 4744 else 4745 psb->ps_write = ps; 4746 4747 done: 4748 /* mark CPU as needing processing */ 4749 if (callchaindepth != PMC_SAMPLE_INUSE) 4750 DPCPU_SET(pmc_sampled, 1); 4751 4752 return (error); 4753 } 4754 4755 /* 4756 * Interrupt processing. 4757 * 4758 * This function is meant to be called from an NMI handler. It cannot 4759 * use any of the locking primitives supplied by the OS. 4760 */ 4761 4762 int 4763 pmc_process_interrupt(int ring, struct pmc *pm, struct trapframe *tf) 4764 { 4765 struct thread *td; 4766 4767 td = curthread; 4768 if ((pm->pm_flags & PMC_F_USERCALLCHAIN) && 4769 (td->td_proc->p_flag & P_KPROC) == 0 && 4770 !TRAPF_USERMODE(tf)) { 4771 atomic_add_int(&td->td_pmcpend, 1); 4772 return (pmc_add_sample(PMC_UR, pm, tf)); 4773 } 4774 return (pmc_add_sample(ring, pm, tf)); 4775 } 4776 4777 /* 4778 * Capture a user call chain. This function will be called from ast() 4779 * before control returns to userland and before the process gets 4780 * rescheduled. 4781 */ 4782 4783 static void 4784 pmc_capture_user_callchain(int cpu, int ring, struct trapframe *tf) 4785 { 4786 struct pmc *pm; 4787 struct thread *td; 4788 struct pmc_sample *ps, *ps_end; 4789 struct pmc_samplebuffer *psb; 4790 int nsamples, nrecords, pass; 4791 #ifdef INVARIANTS 4792 int ncallchains; 4793 int nfree; 4794 #endif 4795 4796 psb = pmc_pcpu[cpu]->pc_sb[ring]; 4797 td = curthread; 4798 4799 KASSERT(td->td_pflags & TDP_CALLCHAIN, 4800 ("[pmc,%d] Retrieving callchain for thread that doesn't want it", 4801 __LINE__)); 4802 4803 #ifdef INVARIANTS 4804 ncallchains = 0; 4805 nfree = 0; 4806 #endif 4807 nrecords = INT_MAX; 4808 pass = 0; 4809 restart: 4810 if (ring == PMC_UR) 4811 nrecords = atomic_readandclear_32(&td->td_pmcpend); 4812 4813 /* 4814 * Iterate through all deferred callchain requests. 4815 * Walk from the current read pointer to the current 4816 * write pointer. 4817 */ 4818 4819 ps = psb->ps_read; 4820 ps_end = psb->ps_write; 4821 do { 4822 #ifdef INVARIANTS 4823 if (ps->ps_nsamples == PMC_SAMPLE_FREE) { 4824 nfree++; 4825 goto next; 4826 } 4827 4828 if ((ps->ps_pmc == NULL) || 4829 (ps->ps_pmc->pm_state != PMC_STATE_RUNNING)) 4830 nfree++; 4831 #endif 4832 if (ps->ps_nsamples != PMC_SAMPLE_INUSE) 4833 goto next; 4834 if (ps->ps_td != td) 4835 goto next; 4836 4837 KASSERT(ps->ps_cpu == cpu, 4838 ("[pmc,%d] cpu mismatch ps_cpu=%d pcpu=%d", __LINE__, 4839 ps->ps_cpu, PCPU_GET(cpuid))); 4840 4841 pm = ps->ps_pmc; 4842 4843 KASSERT(pm->pm_flags & PMC_F_CALLCHAIN, 4844 ("[pmc,%d] Retrieving callchain for PMC that doesn't " 4845 "want it", __LINE__)); 4846 4847 KASSERT(counter_u64_fetch(pm->pm_runcount) > 0, 4848 ("[pmc,%d] runcount %ld", __LINE__, (unsigned long)counter_u64_fetch(pm->pm_runcount))); 4849 4850 if (ring == PMC_UR) { 4851 nsamples = ps->ps_nsamples_actual; 4852 counter_u64_add(pmc_stats.pm_merges, 1); 4853 } else 4854 nsamples = 0; 4855 4856 /* 4857 * Retrieve the callchain and mark the sample buffer 4858 * as 'processable' by the timer tick sweep code. 4859 */ 4860 4861 #ifdef INVARIANTS 4862 ncallchains++; 4863 #endif 4864 4865 if (__predict_true(nsamples < pmc_callchaindepth - 1)) 4866 nsamples += pmc_save_user_callchain(ps->ps_pc + nsamples, 4867 pmc_callchaindepth - nsamples - 1, tf); 4868 wmb(); 4869 ps->ps_nsamples = nsamples; 4870 if (nrecords-- == 1) 4871 break; 4872 next: 4873 /* increment the pointer, modulo sample ring size */ 4874 if (++ps == psb->ps_fence) 4875 ps = psb->ps_samples; 4876 } while (ps != ps_end); 4877 if (__predict_false(ring == PMC_UR && td->td_pmcpend)) { 4878 if (pass == 0) { 4879 pass = 1; 4880 goto restart; 4881 } 4882 /* only collect samples for this part once */ 4883 td->td_pmcpend = 0; 4884 } 4885 4886 #ifdef INVARIANTS 4887 if (ring == PMC_HR) 4888 KASSERT(ncallchains > 0 || nfree > 0, 4889 ("[pmc,%d] cpu %d didn't find a sample to collect", __LINE__, 4890 cpu)); 4891 #endif 4892 4893 /* mark CPU as needing processing */ 4894 DPCPU_SET(pmc_sampled, 1); 4895 } 4896 4897 4898 static void 4899 pmc_flush_ring(int cpu, int ring) 4900 { 4901 struct pmc *pm; 4902 struct pmc_sample *ps; 4903 struct pmc_samplebuffer *psb; 4904 int n; 4905 4906 psb = pmc_pcpu[cpu]->pc_sb[ring]; 4907 4908 for (n = 0; n < pmc_nsamples; n++) { /* bound on #iterations */ 4909 4910 ps = psb->ps_read; 4911 if (ps->ps_nsamples == PMC_SAMPLE_FREE) 4912 goto next; 4913 pm = ps->ps_pmc; 4914 counter_u64_add(pm->pm_runcount, -1); 4915 ps->ps_nsamples = PMC_SAMPLE_FREE; 4916 /* increment read pointer, modulo sample size */ 4917 next: 4918 if (++ps == psb->ps_fence) 4919 psb->ps_read = psb->ps_samples; 4920 else 4921 psb->ps_read = ps; 4922 } 4923 } 4924 4925 void 4926 pmc_flush_samples(int cpu) 4927 { 4928 int n; 4929 4930 for (n = 0; n < PMC_NUM_SR; n++) 4931 pmc_flush_ring(cpu, n); 4932 } 4933 4934 4935 /* 4936 * Process saved PC samples. 4937 */ 4938 4939 static void 4940 pmc_process_samples(int cpu, int ring) 4941 { 4942 struct pmc *pm; 4943 int adjri, n; 4944 struct thread *td; 4945 struct pmc_owner *po; 4946 struct pmc_sample *ps; 4947 struct pmc_classdep *pcd; 4948 struct pmc_samplebuffer *psb; 4949 4950 KASSERT(PCPU_GET(cpuid) == cpu, 4951 ("[pmc,%d] not on the correct CPU pcpu=%d cpu=%d", __LINE__, 4952 PCPU_GET(cpuid), cpu)); 4953 4954 psb = pmc_pcpu[cpu]->pc_sb[ring]; 4955 4956 for (n = 0; n < pmc_nsamples; n++) { /* bound on #iterations */ 4957 4958 ps = psb->ps_read; 4959 if (ps->ps_nsamples == PMC_SAMPLE_FREE) 4960 break; 4961 4962 pm = ps->ps_pmc; 4963 4964 KASSERT(counter_u64_fetch(pm->pm_runcount) > 0, 4965 ("[pmc,%d] pm=%p runcount %ld", __LINE__, (void *) pm, 4966 (unsigned long)counter_u64_fetch(pm->pm_runcount))); 4967 4968 po = pm->pm_owner; 4969 4970 KASSERT(PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)), 4971 ("[pmc,%d] pmc=%p non-sampling mode=%d", __LINE__, 4972 pm, PMC_TO_MODE(pm))); 4973 4974 /* Ignore PMCs that have been switched off */ 4975 if (pm->pm_state != PMC_STATE_RUNNING) 4976 goto entrydone; 4977 4978 /* If there is a pending AST wait for completion */ 4979 if (ps->ps_nsamples == PMC_SAMPLE_INUSE) { 4980 /* Need a rescan at a later time. */ 4981 DPCPU_SET(pmc_sampled, 1); 4982 break; 4983 } 4984 4985 PMCDBG6(SAM,OPS,1,"cpu=%d pm=%p n=%d fl=%x wr=%d rd=%d", cpu, 4986 pm, ps->ps_nsamples, ps->ps_flags, 4987 (int) (psb->ps_write - psb->ps_samples), 4988 (int) (psb->ps_read - psb->ps_samples)); 4989 4990 /* 4991 * If this is a process-mode PMC that is attached to 4992 * its owner, and if the PC is in user mode, update 4993 * profiling statistics like timer-based profiling 4994 * would have done. 4995 * 4996 * Otherwise, this is either a sampling-mode PMC that 4997 * is attached to a different process than its owner, 4998 * or a system-wide sampling PMC. Dispatch a log 4999 * entry to the PMC's owner process. 5000 */ 5001 if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) { 5002 if (ps->ps_flags & PMC_CC_F_USERSPACE) { 5003 td = FIRST_THREAD_IN_PROC(po->po_owner); 5004 addupc_intr(td, ps->ps_pc[0], 1); 5005 } 5006 } else 5007 pmclog_process_callchain(pm, ps); 5008 5009 entrydone: 5010 ps->ps_nsamples = 0; /* mark entry as free */ 5011 counter_u64_add(pm->pm_runcount, -1); 5012 5013 /* increment read pointer, modulo sample size */ 5014 if (++ps == psb->ps_fence) 5015 psb->ps_read = psb->ps_samples; 5016 else 5017 psb->ps_read = ps; 5018 } 5019 5020 counter_u64_add(pmc_stats.pm_log_sweeps, 1); 5021 5022 /* Do not re-enable stalled PMCs if we failed to process any samples */ 5023 if (n == 0) 5024 return; 5025 5026 /* 5027 * Restart any stalled sampling PMCs on this CPU. 5028 * 5029 * If the NMI handler sets the pm_stalled field of a PMC after 5030 * the check below, we'll end up processing the stalled PMC at 5031 * the next hardclock tick. 5032 */ 5033 for (n = 0; n < md->pmd_npmc; n++) { 5034 pcd = pmc_ri_to_classdep(md, n, &adjri); 5035 KASSERT(pcd != NULL, 5036 ("[pmc,%d] null pcd ri=%d", __LINE__, n)); 5037 (void) (*pcd->pcd_get_config)(cpu,adjri,&pm); 5038 5039 if (pm == NULL || /* !cfg'ed */ 5040 pm->pm_state != PMC_STATE_RUNNING || /* !active */ 5041 !PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)) || /* !sampling */ 5042 !pm->pm_pcpu_state[cpu].pps_cpustate || /* !desired */ 5043 !pm->pm_pcpu_state[cpu].pps_stalled) /* !stalled */ 5044 continue; 5045 5046 pm->pm_pcpu_state[cpu].pps_stalled = 0; 5047 (*pcd->pcd_start_pmc)(cpu, adjri); 5048 } 5049 } 5050 5051 /* 5052 * Event handlers. 5053 */ 5054 5055 /* 5056 * Handle a process exit. 5057 * 5058 * Remove this process from all hash tables. If this process 5059 * owned any PMCs, turn off those PMCs and deallocate them, 5060 * removing any associations with target processes. 5061 * 5062 * This function will be called by the last 'thread' of a 5063 * process. 5064 * 5065 * XXX This eventhandler gets called early in the exit process. 5066 * Consider using a 'hook' invocation from thread_exit() or equivalent 5067 * spot. Another negative is that kse_exit doesn't seem to call 5068 * exit1() [??]. 5069 * 5070 */ 5071 5072 static void 5073 pmc_process_exit(void *arg __unused, struct proc *p) 5074 { 5075 struct pmc *pm; 5076 int adjri, cpu; 5077 unsigned int ri; 5078 int is_using_hwpmcs; 5079 struct pmc_owner *po; 5080 struct pmc_process *pp; 5081 struct pmc_classdep *pcd; 5082 pmc_value_t newvalue, tmp; 5083 5084 PROC_LOCK(p); 5085 is_using_hwpmcs = p->p_flag & P_HWPMC; 5086 PROC_UNLOCK(p); 5087 5088 /* 5089 * Log a sysexit event to all SS PMC owners. 5090 */ 5091 PMC_EPOCH_ENTER(); 5092 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 5093 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 5094 pmclog_process_sysexit(po, p->p_pid); 5095 PMC_EPOCH_EXIT(); 5096 5097 if (!is_using_hwpmcs) 5098 return; 5099 5100 PMC_GET_SX_XLOCK(); 5101 PMCDBG3(PRC,EXT,1,"process-exit proc=%p (%d, %s)", p, p->p_pid, 5102 p->p_comm); 5103 5104 /* 5105 * Since this code is invoked by the last thread in an exiting 5106 * process, we would have context switched IN at some prior 5107 * point. However, with PREEMPTION, kernel mode context 5108 * switches may happen any time, so we want to disable a 5109 * context switch OUT till we get any PMCs targeting this 5110 * process off the hardware. 5111 * 5112 * We also need to atomically remove this process' 5113 * entry from our target process hash table, using 5114 * PMC_FLAG_REMOVE. 5115 */ 5116 PMCDBG3(PRC,EXT,1, "process-exit proc=%p (%d, %s)", p, p->p_pid, 5117 p->p_comm); 5118 5119 critical_enter(); /* no preemption */ 5120 5121 cpu = curthread->td_oncpu; 5122 5123 if ((pp = pmc_find_process_descriptor(p, 5124 PMC_FLAG_REMOVE)) != NULL) { 5125 5126 PMCDBG2(PRC,EXT,2, 5127 "process-exit proc=%p pmc-process=%p", p, pp); 5128 5129 /* 5130 * The exiting process could the target of 5131 * some PMCs which will be running on 5132 * currently executing CPU. 5133 * 5134 * We need to turn these PMCs off like we 5135 * would do at context switch OUT time. 5136 */ 5137 for (ri = 0; ri < md->pmd_npmc; ri++) { 5138 5139 /* 5140 * Pick up the pmc pointer from hardware 5141 * state similar to the CSW_OUT code. 5142 */ 5143 pm = NULL; 5144 5145 pcd = pmc_ri_to_classdep(md, ri, &adjri); 5146 5147 (void) (*pcd->pcd_get_config)(cpu, adjri, &pm); 5148 5149 PMCDBG2(PRC,EXT,2, "ri=%d pm=%p", ri, pm); 5150 5151 if (pm == NULL || 5152 !PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) 5153 continue; 5154 5155 PMCDBG4(PRC,EXT,2, "ppmcs[%d]=%p pm=%p " 5156 "state=%d", ri, pp->pp_pmcs[ri].pp_pmc, 5157 pm, pm->pm_state); 5158 5159 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 5160 ("[pmc,%d] ri mismatch pmc(%d) ri(%d)", 5161 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 5162 5163 KASSERT(pm == pp->pp_pmcs[ri].pp_pmc, 5164 ("[pmc,%d] pm %p != pp_pmcs[%d] %p", 5165 __LINE__, pm, ri, pp->pp_pmcs[ri].pp_pmc)); 5166 5167 KASSERT(counter_u64_fetch(pm->pm_runcount) > 0, 5168 ("[pmc,%d] bad runcount ri %d rc %ld", 5169 __LINE__, ri, (unsigned long)counter_u64_fetch(pm->pm_runcount))); 5170 5171 /* 5172 * Change desired state, and then stop if not 5173 * stalled. This two-step dance should avoid 5174 * race conditions where an interrupt re-enables 5175 * the PMC after this code has already checked 5176 * the pm_stalled flag. 5177 */ 5178 if (pm->pm_pcpu_state[cpu].pps_cpustate) { 5179 pm->pm_pcpu_state[cpu].pps_cpustate = 0; 5180 if (!pm->pm_pcpu_state[cpu].pps_stalled) { 5181 (void) pcd->pcd_stop_pmc(cpu, adjri); 5182 5183 if (PMC_TO_MODE(pm) == PMC_MODE_TC) { 5184 pcd->pcd_read_pmc(cpu, adjri, 5185 &newvalue); 5186 tmp = newvalue - 5187 PMC_PCPU_SAVED(cpu,ri); 5188 5189 mtx_pool_lock_spin(pmc_mtxpool, 5190 pm); 5191 pm->pm_gv.pm_savedvalue += tmp; 5192 pp->pp_pmcs[ri].pp_pmcval += 5193 tmp; 5194 mtx_pool_unlock_spin( 5195 pmc_mtxpool, pm); 5196 } 5197 } 5198 } 5199 5200 counter_u64_add(pm->pm_runcount, -1); 5201 5202 KASSERT((int) counter_u64_fetch(pm->pm_runcount) >= 0, 5203 ("[pmc,%d] runcount is %d", __LINE__, ri)); 5204 5205 (void) pcd->pcd_config_pmc(cpu, adjri, NULL); 5206 } 5207 5208 /* 5209 * Inform the MD layer of this pseudo "context switch 5210 * out" 5211 */ 5212 (void) md->pmd_switch_out(pmc_pcpu[cpu], pp); 5213 5214 critical_exit(); /* ok to be pre-empted now */ 5215 5216 /* 5217 * Unlink this process from the PMCs that are 5218 * targeting it. This will send a signal to 5219 * all PMC owner's whose PMCs are orphaned. 5220 * 5221 * Log PMC value at exit time if requested. 5222 */ 5223 for (ri = 0; ri < md->pmd_npmc; ri++) 5224 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) { 5225 if (pm->pm_flags & PMC_F_NEEDS_LOGFILE && 5226 PMC_IS_COUNTING_MODE(PMC_TO_MODE(pm))) 5227 pmclog_process_procexit(pm, pp); 5228 pmc_unlink_target_process(pm, pp); 5229 } 5230 free(pp, M_PMC); 5231 5232 } else 5233 critical_exit(); /* pp == NULL */ 5234 5235 5236 /* 5237 * If the process owned PMCs, free them up and free up 5238 * memory. 5239 */ 5240 if ((po = pmc_find_owner_descriptor(p)) != NULL) { 5241 pmc_remove_owner(po); 5242 pmc_destroy_owner_descriptor(po); 5243 } 5244 5245 sx_xunlock(&pmc_sx); 5246 } 5247 5248 /* 5249 * Handle a process fork. 5250 * 5251 * If the parent process 'p1' is under HWPMC monitoring, then copy 5252 * over any attached PMCs that have 'do_descendants' semantics. 5253 */ 5254 5255 static void 5256 pmc_process_fork(void *arg __unused, struct proc *p1, struct proc *newproc, 5257 int flags) 5258 { 5259 int is_using_hwpmcs; 5260 unsigned int ri; 5261 uint32_t do_descendants; 5262 struct pmc *pm; 5263 struct pmc_owner *po; 5264 struct pmc_process *ppnew, *ppold; 5265 5266 (void) flags; /* unused parameter */ 5267 5268 PROC_LOCK(p1); 5269 is_using_hwpmcs = p1->p_flag & P_HWPMC; 5270 PROC_UNLOCK(p1); 5271 5272 /* 5273 * If there are system-wide sampling PMCs active, we need to 5274 * log all fork events to their owner's logs. 5275 */ 5276 PMC_EPOCH_ENTER(); 5277 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 5278 if (po->po_flags & PMC_PO_OWNS_LOGFILE) { 5279 pmclog_process_procfork(po, p1->p_pid, newproc->p_pid); 5280 pmclog_process_proccreate(po, newproc, 1); 5281 } 5282 PMC_EPOCH_EXIT(); 5283 5284 if (!is_using_hwpmcs) 5285 return; 5286 5287 PMC_GET_SX_XLOCK(); 5288 PMCDBG4(PMC,FRK,1, "process-fork proc=%p (%d, %s) -> %p", p1, 5289 p1->p_pid, p1->p_comm, newproc); 5290 5291 /* 5292 * If the parent process (curthread->td_proc) is a 5293 * target of any PMCs, look for PMCs that are to be 5294 * inherited, and link these into the new process 5295 * descriptor. 5296 */ 5297 if ((ppold = pmc_find_process_descriptor(curthread->td_proc, 5298 PMC_FLAG_NONE)) == NULL) 5299 goto done; /* nothing to do */ 5300 5301 do_descendants = 0; 5302 for (ri = 0; ri < md->pmd_npmc; ri++) 5303 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL) 5304 do_descendants |= pm->pm_flags & PMC_F_DESCENDANTS; 5305 if (do_descendants == 0) /* nothing to do */ 5306 goto done; 5307 5308 /* 5309 * Now mark the new process as being tracked by this driver. 5310 */ 5311 PROC_LOCK(newproc); 5312 newproc->p_flag |= P_HWPMC; 5313 PROC_UNLOCK(newproc); 5314 5315 /* allocate a descriptor for the new process */ 5316 if ((ppnew = pmc_find_process_descriptor(newproc, 5317 PMC_FLAG_ALLOCATE)) == NULL) 5318 goto done; 5319 5320 /* 5321 * Run through all PMCs that were targeting the old process 5322 * and which specified F_DESCENDANTS and attach them to the 5323 * new process. 5324 * 5325 * Log the fork event to all owners of PMCs attached to this 5326 * process, if not already logged. 5327 */ 5328 for (ri = 0; ri < md->pmd_npmc; ri++) 5329 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL && 5330 (pm->pm_flags & PMC_F_DESCENDANTS)) { 5331 pmc_link_target_process(pm, ppnew); 5332 po = pm->pm_owner; 5333 if (po->po_sscount == 0 && 5334 po->po_flags & PMC_PO_OWNS_LOGFILE) 5335 pmclog_process_procfork(po, p1->p_pid, 5336 newproc->p_pid); 5337 } 5338 5339 done: 5340 sx_xunlock(&pmc_sx); 5341 } 5342 5343 static void 5344 pmc_process_threadcreate(struct thread *td) 5345 { 5346 struct pmc_owner *po; 5347 5348 PMC_EPOCH_ENTER(); 5349 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 5350 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 5351 pmclog_process_threadcreate(po, td, 1); 5352 PMC_EPOCH_EXIT(); 5353 } 5354 5355 static void 5356 pmc_process_threadexit(struct thread *td) 5357 { 5358 struct pmc_owner *po; 5359 5360 PMC_EPOCH_ENTER(); 5361 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 5362 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 5363 pmclog_process_threadexit(po, td); 5364 PMC_EPOCH_EXIT(); 5365 } 5366 5367 static void 5368 pmc_process_proccreate(struct proc *p) 5369 { 5370 struct pmc_owner *po; 5371 5372 PMC_EPOCH_ENTER(); 5373 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 5374 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 5375 pmclog_process_proccreate(po, p, 1 /* sync */); 5376 PMC_EPOCH_EXIT(); 5377 } 5378 5379 static void 5380 pmc_process_allproc(struct pmc *pm) 5381 { 5382 struct pmc_owner *po; 5383 struct thread *td; 5384 struct proc *p; 5385 5386 po = pm->pm_owner; 5387 if ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) 5388 return; 5389 sx_slock(&allproc_lock); 5390 FOREACH_PROC_IN_SYSTEM(p) { 5391 pmclog_process_proccreate(po, p, 0 /* sync */); 5392 PROC_LOCK(p); 5393 FOREACH_THREAD_IN_PROC(p, td) 5394 pmclog_process_threadcreate(po, td, 0 /* sync */); 5395 PROC_UNLOCK(p); 5396 } 5397 sx_sunlock(&allproc_lock); 5398 pmclog_flush(po, 0); 5399 } 5400 5401 static void 5402 pmc_kld_load(void *arg __unused, linker_file_t lf) 5403 { 5404 struct pmc_owner *po; 5405 5406 /* 5407 * Notify owners of system sampling PMCs about KLD operations. 5408 */ 5409 PMC_EPOCH_ENTER(); 5410 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 5411 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 5412 pmclog_process_map_in(po, (pid_t) -1, 5413 (uintfptr_t) lf->address, lf->filename); 5414 PMC_EPOCH_EXIT(); 5415 5416 /* 5417 * TODO: Notify owners of (all) process-sampling PMCs too. 5418 */ 5419 } 5420 5421 static void 5422 pmc_kld_unload(void *arg __unused, const char *filename __unused, 5423 caddr_t address, size_t size) 5424 { 5425 struct pmc_owner *po; 5426 5427 PMC_EPOCH_ENTER(); 5428 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 5429 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 5430 pmclog_process_map_out(po, (pid_t) -1, 5431 (uintfptr_t) address, (uintfptr_t) address + size); 5432 PMC_EPOCH_EXIT(); 5433 5434 /* 5435 * TODO: Notify owners of process-sampling PMCs. 5436 */ 5437 } 5438 5439 /* 5440 * initialization 5441 */ 5442 static const char * 5443 pmc_name_of_pmcclass(enum pmc_class class) 5444 { 5445 5446 switch (class) { 5447 #undef __PMC_CLASS 5448 #define __PMC_CLASS(S,V,D) \ 5449 case PMC_CLASS_##S: \ 5450 return #S; 5451 __PMC_CLASSES(); 5452 default: 5453 return ("<unknown>"); 5454 } 5455 } 5456 5457 /* 5458 * Base class initializer: allocate structure and set default classes. 5459 */ 5460 struct pmc_mdep * 5461 pmc_mdep_alloc(int nclasses) 5462 { 5463 struct pmc_mdep *md; 5464 int n; 5465 5466 /* SOFT + md classes */ 5467 n = 1 + nclasses; 5468 md = malloc(sizeof(struct pmc_mdep) + n * 5469 sizeof(struct pmc_classdep), M_PMC, M_WAITOK|M_ZERO); 5470 md->pmd_nclass = n; 5471 5472 /* Add base class. */ 5473 pmc_soft_initialize(md); 5474 return md; 5475 } 5476 5477 void 5478 pmc_mdep_free(struct pmc_mdep *md) 5479 { 5480 pmc_soft_finalize(md); 5481 free(md, M_PMC); 5482 } 5483 5484 static int 5485 generic_switch_in(struct pmc_cpu *pc, struct pmc_process *pp) 5486 { 5487 (void) pc; (void) pp; 5488 5489 return (0); 5490 } 5491 5492 static int 5493 generic_switch_out(struct pmc_cpu *pc, struct pmc_process *pp) 5494 { 5495 (void) pc; (void) pp; 5496 5497 return (0); 5498 } 5499 5500 static struct pmc_mdep * 5501 pmc_generic_cpu_initialize(void) 5502 { 5503 struct pmc_mdep *md; 5504 5505 md = pmc_mdep_alloc(0); 5506 5507 md->pmd_cputype = PMC_CPU_GENERIC; 5508 5509 md->pmd_pcpu_init = NULL; 5510 md->pmd_pcpu_fini = NULL; 5511 md->pmd_switch_in = generic_switch_in; 5512 md->pmd_switch_out = generic_switch_out; 5513 5514 return (md); 5515 } 5516 5517 static void 5518 pmc_generic_cpu_finalize(struct pmc_mdep *md) 5519 { 5520 (void) md; 5521 } 5522 5523 5524 static int 5525 pmc_initialize(void) 5526 { 5527 int c, cpu, error, n, ri; 5528 unsigned int maxcpu, domain; 5529 struct pcpu *pc; 5530 struct pmc_binding pb; 5531 struct pmc_sample *ps; 5532 struct pmc_classdep *pcd; 5533 struct pmc_samplebuffer *sb; 5534 5535 md = NULL; 5536 error = 0; 5537 5538 pmc_stats.pm_intr_ignored = counter_u64_alloc(M_WAITOK); 5539 pmc_stats.pm_intr_processed = counter_u64_alloc(M_WAITOK); 5540 pmc_stats.pm_intr_bufferfull = counter_u64_alloc(M_WAITOK); 5541 pmc_stats.pm_syscalls = counter_u64_alloc(M_WAITOK); 5542 pmc_stats.pm_syscall_errors = counter_u64_alloc(M_WAITOK); 5543 pmc_stats.pm_buffer_requests = counter_u64_alloc(M_WAITOK); 5544 pmc_stats.pm_buffer_requests_failed = counter_u64_alloc(M_WAITOK); 5545 pmc_stats.pm_log_sweeps = counter_u64_alloc(M_WAITOK); 5546 pmc_stats.pm_merges = counter_u64_alloc(M_WAITOK); 5547 pmc_stats.pm_overwrites = counter_u64_alloc(M_WAITOK); 5548 5549 #ifdef HWPMC_DEBUG 5550 /* parse debug flags first */ 5551 if (TUNABLE_STR_FETCH(PMC_SYSCTL_NAME_PREFIX "debugflags", 5552 pmc_debugstr, sizeof(pmc_debugstr))) 5553 pmc_debugflags_parse(pmc_debugstr, 5554 pmc_debugstr+strlen(pmc_debugstr)); 5555 #endif 5556 5557 PMCDBG1(MOD,INI,0, "PMC Initialize (version %x)", PMC_VERSION); 5558 5559 /* check kernel version */ 5560 if (pmc_kernel_version != PMC_VERSION) { 5561 if (pmc_kernel_version == 0) 5562 printf("hwpmc: this kernel has not been compiled with " 5563 "'options HWPMC_HOOKS'.\n"); 5564 else 5565 printf("hwpmc: kernel version (0x%x) does not match " 5566 "module version (0x%x).\n", pmc_kernel_version, 5567 PMC_VERSION); 5568 return EPROGMISMATCH; 5569 } 5570 5571 /* 5572 * check sysctl parameters 5573 */ 5574 5575 if (pmc_hashsize <= 0) { 5576 (void) printf("hwpmc: tunable \"hashsize\"=%d must be " 5577 "greater than zero.\n", pmc_hashsize); 5578 pmc_hashsize = PMC_HASH_SIZE; 5579 } 5580 5581 if (pmc_nsamples <= 0 || pmc_nsamples > 65535) { 5582 (void) printf("hwpmc: tunable \"nsamples\"=%d out of " 5583 "range.\n", pmc_nsamples); 5584 pmc_nsamples = PMC_NSAMPLES; 5585 } 5586 5587 if (pmc_callchaindepth <= 0 || 5588 pmc_callchaindepth > PMC_CALLCHAIN_DEPTH_MAX) { 5589 (void) printf("hwpmc: tunable \"callchaindepth\"=%d out of " 5590 "range - using %d.\n", pmc_callchaindepth, 5591 PMC_CALLCHAIN_DEPTH_MAX); 5592 pmc_callchaindepth = PMC_CALLCHAIN_DEPTH_MAX; 5593 } 5594 5595 md = pmc_md_initialize(); 5596 if (md == NULL) { 5597 /* Default to generic CPU. */ 5598 md = pmc_generic_cpu_initialize(); 5599 if (md == NULL) 5600 return (ENOSYS); 5601 } 5602 5603 KASSERT(md->pmd_nclass >= 1 && md->pmd_npmc >= 1, 5604 ("[pmc,%d] no classes or pmcs", __LINE__)); 5605 5606 /* Compute the map from row-indices to classdep pointers. */ 5607 pmc_rowindex_to_classdep = malloc(sizeof(struct pmc_classdep *) * 5608 md->pmd_npmc, M_PMC, M_WAITOK|M_ZERO); 5609 5610 for (n = 0; n < md->pmd_npmc; n++) 5611 pmc_rowindex_to_classdep[n] = NULL; 5612 for (ri = c = 0; c < md->pmd_nclass; c++) { 5613 pcd = &md->pmd_classdep[c]; 5614 for (n = 0; n < pcd->pcd_num; n++, ri++) 5615 pmc_rowindex_to_classdep[ri] = pcd; 5616 } 5617 5618 KASSERT(ri == md->pmd_npmc, 5619 ("[pmc,%d] npmc miscomputed: ri=%d, md->npmc=%d", __LINE__, 5620 ri, md->pmd_npmc)); 5621 5622 maxcpu = pmc_cpu_max(); 5623 5624 /* allocate space for the per-cpu array */ 5625 pmc_pcpu = malloc(maxcpu * sizeof(struct pmc_cpu *), M_PMC, 5626 M_WAITOK|M_ZERO); 5627 5628 /* per-cpu 'saved values' for managing process-mode PMCs */ 5629 pmc_pcpu_saved = malloc(sizeof(pmc_value_t) * maxcpu * md->pmd_npmc, 5630 M_PMC, M_WAITOK); 5631 5632 /* Perform CPU-dependent initialization. */ 5633 pmc_save_cpu_binding(&pb); 5634 error = 0; 5635 for (cpu = 0; error == 0 && cpu < maxcpu; cpu++) { 5636 if (!pmc_cpu_is_active(cpu)) 5637 continue; 5638 pmc_select_cpu(cpu); 5639 pmc_pcpu[cpu] = malloc(sizeof(struct pmc_cpu) + 5640 md->pmd_npmc * sizeof(struct pmc_hw *), M_PMC, 5641 M_WAITOK|M_ZERO); 5642 if (md->pmd_pcpu_init) 5643 error = md->pmd_pcpu_init(md, cpu); 5644 for (n = 0; error == 0 && n < md->pmd_nclass; n++) 5645 error = md->pmd_classdep[n].pcd_pcpu_init(md, cpu); 5646 } 5647 pmc_restore_cpu_binding(&pb); 5648 5649 if (error) 5650 return (error); 5651 5652 /* allocate space for the sample array */ 5653 for (cpu = 0; cpu < maxcpu; cpu++) { 5654 if (!pmc_cpu_is_active(cpu)) 5655 continue; 5656 pc = pcpu_find(cpu); 5657 domain = pc->pc_domain; 5658 sb = malloc_domain(sizeof(struct pmc_samplebuffer) + 5659 pmc_nsamples * sizeof(struct pmc_sample), M_PMC, domain, 5660 M_WAITOK|M_ZERO); 5661 sb->ps_read = sb->ps_write = sb->ps_samples; 5662 sb->ps_fence = sb->ps_samples + pmc_nsamples; 5663 5664 KASSERT(pmc_pcpu[cpu] != NULL, 5665 ("[pmc,%d] cpu=%d Null per-cpu data", __LINE__, cpu)); 5666 5667 sb->ps_callchains = malloc_domain(pmc_callchaindepth * pmc_nsamples * 5668 sizeof(uintptr_t), M_PMC, domain, M_WAITOK|M_ZERO); 5669 5670 for (n = 0, ps = sb->ps_samples; n < pmc_nsamples; n++, ps++) 5671 ps->ps_pc = sb->ps_callchains + 5672 (n * pmc_callchaindepth); 5673 5674 pmc_pcpu[cpu]->pc_sb[PMC_HR] = sb; 5675 5676 sb = malloc_domain(sizeof(struct pmc_samplebuffer) + 5677 pmc_nsamples * sizeof(struct pmc_sample), M_PMC, domain, 5678 M_WAITOK|M_ZERO); 5679 sb->ps_read = sb->ps_write = sb->ps_samples; 5680 sb->ps_fence = sb->ps_samples + pmc_nsamples; 5681 5682 KASSERT(pmc_pcpu[cpu] != NULL, 5683 ("[pmc,%d] cpu=%d Null per-cpu data", __LINE__, cpu)); 5684 5685 sb->ps_callchains = malloc_domain(pmc_callchaindepth * pmc_nsamples * 5686 sizeof(uintptr_t), M_PMC, domain, M_WAITOK|M_ZERO); 5687 5688 for (n = 0, ps = sb->ps_samples; n < pmc_nsamples; n++, ps++) 5689 ps->ps_pc = sb->ps_callchains + 5690 (n * pmc_callchaindepth); 5691 5692 pmc_pcpu[cpu]->pc_sb[PMC_SR] = sb; 5693 5694 sb = malloc_domain(sizeof(struct pmc_samplebuffer) + 5695 pmc_nsamples * sizeof(struct pmc_sample), M_PMC, domain, 5696 M_WAITOK|M_ZERO); 5697 sb->ps_read = sb->ps_write = sb->ps_samples; 5698 sb->ps_fence = sb->ps_samples + pmc_nsamples; 5699 5700 KASSERT(pmc_pcpu[cpu] != NULL, 5701 ("[pmc,%d] cpu=%d Null per-cpu data", __LINE__, cpu)); 5702 5703 sb->ps_callchains = malloc_domain(pmc_callchaindepth * pmc_nsamples * 5704 sizeof(uintptr_t), M_PMC, domain, M_WAITOK|M_ZERO); 5705 5706 for (n = 0, ps = sb->ps_samples; n < pmc_nsamples; n++, ps++) 5707 ps->ps_pc = sb->ps_callchains + 5708 (n * pmc_callchaindepth); 5709 5710 pmc_pcpu[cpu]->pc_sb[PMC_UR] = sb; 5711 } 5712 5713 /* allocate space for the row disposition array */ 5714 pmc_pmcdisp = malloc(sizeof(enum pmc_mode) * md->pmd_npmc, 5715 M_PMC, M_WAITOK|M_ZERO); 5716 5717 /* mark all PMCs as available */ 5718 for (n = 0; n < (int) md->pmd_npmc; n++) 5719 PMC_MARK_ROW_FREE(n); 5720 5721 /* allocate thread hash tables */ 5722 pmc_ownerhash = hashinit(pmc_hashsize, M_PMC, 5723 &pmc_ownerhashmask); 5724 5725 pmc_processhash = hashinit(pmc_hashsize, M_PMC, 5726 &pmc_processhashmask); 5727 mtx_init(&pmc_processhash_mtx, "pmc-process-hash", "pmc-leaf", 5728 MTX_SPIN); 5729 5730 CK_LIST_INIT(&pmc_ss_owners); 5731 pmc_ss_count = 0; 5732 5733 /* allocate a pool of spin mutexes */ 5734 pmc_mtxpool = mtx_pool_create("pmc-leaf", pmc_mtxpool_size, 5735 MTX_SPIN); 5736 5737 PMCDBG4(MOD,INI,1, "pmc_ownerhash=%p, mask=0x%lx " 5738 "targethash=%p mask=0x%lx", pmc_ownerhash, pmc_ownerhashmask, 5739 pmc_processhash, pmc_processhashmask); 5740 5741 /* Initialize a spin mutex for the thread free list. */ 5742 mtx_init(&pmc_threadfreelist_mtx, "pmc-threadfreelist", "pmc-leaf", 5743 MTX_SPIN); 5744 5745 /* 5746 * Initialize the callout to monitor the thread free list. 5747 * This callout will also handle the initial population of the list. 5748 */ 5749 taskqgroup_config_gtask_init(NULL, &free_gtask, pmc_thread_descriptor_pool_free_task, "thread descriptor pool free task"); 5750 5751 /* register process {exit,fork,exec} handlers */ 5752 pmc_exit_tag = EVENTHANDLER_REGISTER(process_exit, 5753 pmc_process_exit, NULL, EVENTHANDLER_PRI_ANY); 5754 pmc_fork_tag = EVENTHANDLER_REGISTER(process_fork, 5755 pmc_process_fork, NULL, EVENTHANDLER_PRI_ANY); 5756 5757 /* register kld event handlers */ 5758 pmc_kld_load_tag = EVENTHANDLER_REGISTER(kld_load, pmc_kld_load, 5759 NULL, EVENTHANDLER_PRI_ANY); 5760 pmc_kld_unload_tag = EVENTHANDLER_REGISTER(kld_unload, pmc_kld_unload, 5761 NULL, EVENTHANDLER_PRI_ANY); 5762 5763 /* initialize logging */ 5764 pmclog_initialize(); 5765 5766 /* set hook functions */ 5767 pmc_intr = md->pmd_intr; 5768 wmb(); 5769 pmc_hook = pmc_hook_handler; 5770 5771 if (error == 0) { 5772 printf(PMC_MODULE_NAME ":"); 5773 for (n = 0; n < (int) md->pmd_nclass; n++) { 5774 pcd = &md->pmd_classdep[n]; 5775 printf(" %s/%d/%d/0x%b", 5776 pmc_name_of_pmcclass(pcd->pcd_class), 5777 pcd->pcd_num, 5778 pcd->pcd_width, 5779 pcd->pcd_caps, 5780 "\20" 5781 "\1INT\2USR\3SYS\4EDG\5THR" 5782 "\6REA\7WRI\10INV\11QUA\12PRC" 5783 "\13TAG\14CSC"); 5784 } 5785 printf("\n"); 5786 } 5787 5788 return (error); 5789 } 5790 5791 /* prepare to be unloaded */ 5792 static void 5793 pmc_cleanup(void) 5794 { 5795 int c, cpu; 5796 unsigned int maxcpu; 5797 struct pmc_ownerhash *ph; 5798 struct pmc_owner *po, *tmp; 5799 struct pmc_binding pb; 5800 #ifdef HWPMC_DEBUG 5801 struct pmc_processhash *prh; 5802 #endif 5803 5804 PMCDBG0(MOD,INI,0, "cleanup"); 5805 5806 /* switch off sampling */ 5807 CPU_FOREACH(cpu) 5808 DPCPU_ID_SET(cpu, pmc_sampled, 0); 5809 pmc_intr = NULL; 5810 5811 sx_xlock(&pmc_sx); 5812 if (pmc_hook == NULL) { /* being unloaded already */ 5813 sx_xunlock(&pmc_sx); 5814 return; 5815 } 5816 5817 pmc_hook = NULL; /* prevent new threads from entering module */ 5818 5819 /* deregister event handlers */ 5820 EVENTHANDLER_DEREGISTER(process_fork, pmc_fork_tag); 5821 EVENTHANDLER_DEREGISTER(process_exit, pmc_exit_tag); 5822 EVENTHANDLER_DEREGISTER(kld_load, pmc_kld_load_tag); 5823 EVENTHANDLER_DEREGISTER(kld_unload, pmc_kld_unload_tag); 5824 5825 /* send SIGBUS to all owner threads, free up allocations */ 5826 if (pmc_ownerhash) 5827 for (ph = pmc_ownerhash; 5828 ph <= &pmc_ownerhash[pmc_ownerhashmask]; 5829 ph++) { 5830 LIST_FOREACH_SAFE(po, ph, po_next, tmp) { 5831 pmc_remove_owner(po); 5832 5833 /* send SIGBUS to owner processes */ 5834 PMCDBG3(MOD,INI,2, "cleanup signal proc=%p " 5835 "(%d, %s)", po->po_owner, 5836 po->po_owner->p_pid, 5837 po->po_owner->p_comm); 5838 5839 PROC_LOCK(po->po_owner); 5840 kern_psignal(po->po_owner, SIGBUS); 5841 PROC_UNLOCK(po->po_owner); 5842 5843 pmc_destroy_owner_descriptor(po); 5844 } 5845 } 5846 5847 /* reclaim allocated data structures */ 5848 mtx_destroy(&pmc_threadfreelist_mtx); 5849 pmc_thread_descriptor_pool_drain(); 5850 5851 if (pmc_mtxpool) 5852 mtx_pool_destroy(&pmc_mtxpool); 5853 5854 mtx_destroy(&pmc_processhash_mtx); 5855 taskqgroup_config_gtask_deinit(&free_gtask); 5856 if (pmc_processhash) { 5857 #ifdef HWPMC_DEBUG 5858 struct pmc_process *pp; 5859 5860 PMCDBG0(MOD,INI,3, "destroy process hash"); 5861 for (prh = pmc_processhash; 5862 prh <= &pmc_processhash[pmc_processhashmask]; 5863 prh++) 5864 LIST_FOREACH(pp, prh, pp_next) 5865 PMCDBG1(MOD,INI,3, "pid=%d", pp->pp_proc->p_pid); 5866 #endif 5867 5868 hashdestroy(pmc_processhash, M_PMC, pmc_processhashmask); 5869 pmc_processhash = NULL; 5870 } 5871 5872 if (pmc_ownerhash) { 5873 PMCDBG0(MOD,INI,3, "destroy owner hash"); 5874 hashdestroy(pmc_ownerhash, M_PMC, pmc_ownerhashmask); 5875 pmc_ownerhash = NULL; 5876 } 5877 5878 KASSERT(CK_LIST_EMPTY(&pmc_ss_owners), 5879 ("[pmc,%d] Global SS owner list not empty", __LINE__)); 5880 KASSERT(pmc_ss_count == 0, 5881 ("[pmc,%d] Global SS count not empty", __LINE__)); 5882 5883 /* do processor and pmc-class dependent cleanup */ 5884 maxcpu = pmc_cpu_max(); 5885 5886 PMCDBG0(MOD,INI,3, "md cleanup"); 5887 if (md) { 5888 pmc_save_cpu_binding(&pb); 5889 for (cpu = 0; cpu < maxcpu; cpu++) { 5890 PMCDBG2(MOD,INI,1,"pmc-cleanup cpu=%d pcs=%p", 5891 cpu, pmc_pcpu[cpu]); 5892 if (!pmc_cpu_is_active(cpu) || pmc_pcpu[cpu] == NULL) 5893 continue; 5894 pmc_select_cpu(cpu); 5895 for (c = 0; c < md->pmd_nclass; c++) 5896 md->pmd_classdep[c].pcd_pcpu_fini(md, cpu); 5897 if (md->pmd_pcpu_fini) 5898 md->pmd_pcpu_fini(md, cpu); 5899 } 5900 5901 if (md->pmd_cputype == PMC_CPU_GENERIC) 5902 pmc_generic_cpu_finalize(md); 5903 else 5904 pmc_md_finalize(md); 5905 5906 pmc_mdep_free(md); 5907 md = NULL; 5908 pmc_restore_cpu_binding(&pb); 5909 } 5910 5911 /* Free per-cpu descriptors. */ 5912 for (cpu = 0; cpu < maxcpu; cpu++) { 5913 if (!pmc_cpu_is_active(cpu)) 5914 continue; 5915 KASSERT(pmc_pcpu[cpu]->pc_sb[PMC_HR] != NULL, 5916 ("[pmc,%d] Null hw cpu sample buffer cpu=%d", __LINE__, 5917 cpu)); 5918 KASSERT(pmc_pcpu[cpu]->pc_sb[PMC_SR] != NULL, 5919 ("[pmc,%d] Null sw cpu sample buffer cpu=%d", __LINE__, 5920 cpu)); 5921 KASSERT(pmc_pcpu[cpu]->pc_sb[PMC_UR] != NULL, 5922 ("[pmc,%d] Null userret cpu sample buffer cpu=%d", __LINE__, 5923 cpu)); 5924 free_domain(pmc_pcpu[cpu]->pc_sb[PMC_HR]->ps_callchains, M_PMC); 5925 free_domain(pmc_pcpu[cpu]->pc_sb[PMC_HR], M_PMC); 5926 free_domain(pmc_pcpu[cpu]->pc_sb[PMC_SR]->ps_callchains, M_PMC); 5927 free_domain(pmc_pcpu[cpu]->pc_sb[PMC_SR], M_PMC); 5928 free_domain(pmc_pcpu[cpu]->pc_sb[PMC_UR]->ps_callchains, M_PMC); 5929 free_domain(pmc_pcpu[cpu]->pc_sb[PMC_UR], M_PMC); 5930 free_domain(pmc_pcpu[cpu], M_PMC); 5931 } 5932 5933 free(pmc_pcpu, M_PMC); 5934 pmc_pcpu = NULL; 5935 5936 free(pmc_pcpu_saved, M_PMC); 5937 pmc_pcpu_saved = NULL; 5938 5939 if (pmc_pmcdisp) { 5940 free(pmc_pmcdisp, M_PMC); 5941 pmc_pmcdisp = NULL; 5942 } 5943 5944 if (pmc_rowindex_to_classdep) { 5945 free(pmc_rowindex_to_classdep, M_PMC); 5946 pmc_rowindex_to_classdep = NULL; 5947 } 5948 5949 pmclog_shutdown(); 5950 counter_u64_free(pmc_stats.pm_intr_ignored); 5951 counter_u64_free(pmc_stats.pm_intr_processed); 5952 counter_u64_free(pmc_stats.pm_intr_bufferfull); 5953 counter_u64_free(pmc_stats.pm_syscalls); 5954 counter_u64_free(pmc_stats.pm_syscall_errors); 5955 counter_u64_free(pmc_stats.pm_buffer_requests); 5956 counter_u64_free(pmc_stats.pm_buffer_requests_failed); 5957 counter_u64_free(pmc_stats.pm_log_sweeps); 5958 counter_u64_free(pmc_stats.pm_merges); 5959 counter_u64_free(pmc_stats.pm_overwrites); 5960 sx_xunlock(&pmc_sx); /* we are done */ 5961 } 5962 5963 /* 5964 * The function called at load/unload. 5965 */ 5966 5967 static int 5968 load (struct module *module __unused, int cmd, void *arg __unused) 5969 { 5970 int error; 5971 5972 error = 0; 5973 5974 switch (cmd) { 5975 case MOD_LOAD : 5976 /* initialize the subsystem */ 5977 error = pmc_initialize(); 5978 if (error != 0) 5979 break; 5980 PMCDBG2(MOD,INI,1, "syscall=%d maxcpu=%d", 5981 pmc_syscall_num, pmc_cpu_max()); 5982 break; 5983 5984 5985 case MOD_UNLOAD : 5986 case MOD_SHUTDOWN: 5987 pmc_cleanup(); 5988 PMCDBG0(MOD,INI,1, "unloaded"); 5989 break; 5990 5991 default : 5992 error = EINVAL; /* XXX should panic(9) */ 5993 break; 5994 } 5995 5996 return error; 5997 } 5998