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