1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2003-2008 Joseph Koshy 5 * Copyright (c) 2007 The FreeBSD Foundation 6 * Copyright (c) 2018 Matthew Macy 7 * All rights reserved. 8 * 9 * Portions of this software were developed by A. Joseph Koshy under 10 * sponsorship from the FreeBSD Foundation and Google, Inc. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 */ 34 35 #include <sys/cdefs.h> 36 __FBSDID("$FreeBSD$"); 37 38 #include <sys/param.h> 39 #include <sys/systm.h> 40 #include <sys/domainset.h> 41 #include <sys/eventhandler.h> 42 #include <sys/jail.h> 43 #include <sys/kernel.h> 44 #include <sys/kthread.h> 45 #include <sys/limits.h> 46 #include <sys/lock.h> 47 #include <sys/malloc.h> 48 #include <sys/module.h> 49 #include <sys/mount.h> 50 #include <sys/mutex.h> 51 #include <sys/pmc.h> 52 #include <sys/pmckern.h> 53 #include <sys/pmclog.h> 54 #include <sys/priv.h> 55 #include <sys/proc.h> 56 #include <sys/queue.h> 57 #include <sys/resourcevar.h> 58 #include <sys/rwlock.h> 59 #include <sys/sched.h> 60 #include <sys/signalvar.h> 61 #include <sys/smp.h> 62 #include <sys/sx.h> 63 #include <sys/sysctl.h> 64 #include <sys/sysent.h> 65 #include <sys/syslog.h> 66 #include <sys/taskqueue.h> 67 #include <sys/vnode.h> 68 69 #include <sys/linker.h> /* needs to be after <sys/malloc.h> */ 70 71 #include <machine/atomic.h> 72 #include <machine/md_var.h> 73 74 #include <vm/vm.h> 75 #include <vm/vm_extern.h> 76 #include <vm/pmap.h> 77 #include <vm/vm_map.h> 78 #include <vm/vm_object.h> 79 80 #include "hwpmc_soft.h" 81 82 #define PMC_EPOCH_ENTER() struct epoch_tracker pmc_et; epoch_enter_preempt(global_epoch_preempt, &pmc_et) 83 #define PMC_EPOCH_EXIT() epoch_exit_preempt(global_epoch_preempt, &pmc_et) 84 85 /* 86 * Types 87 */ 88 89 enum pmc_flags { 90 PMC_FLAG_NONE = 0x00, /* do nothing */ 91 PMC_FLAG_REMOVE = 0x01, /* atomically remove entry from hash */ 92 PMC_FLAG_ALLOCATE = 0x02, /* add entry to hash if not found */ 93 PMC_FLAG_NOWAIT = 0x04, /* do not wait for mallocs */ 94 }; 95 96 /* 97 * The offset in sysent where the syscall is allocated. 98 */ 99 100 static int pmc_syscall_num = NO_SYSCALL; 101 struct pmc_cpu **pmc_pcpu; /* per-cpu state */ 102 pmc_value_t *pmc_pcpu_saved; /* saved PMC values: CSW handling */ 103 104 #define PMC_PCPU_SAVED(C,R) pmc_pcpu_saved[(R) + md->pmd_npmc*(C)] 105 106 struct mtx_pool *pmc_mtxpool; 107 static int *pmc_pmcdisp; /* PMC row dispositions */ 108 109 #define PMC_ROW_DISP_IS_FREE(R) (pmc_pmcdisp[(R)] == 0) 110 #define PMC_ROW_DISP_IS_THREAD(R) (pmc_pmcdisp[(R)] > 0) 111 #define PMC_ROW_DISP_IS_STANDALONE(R) (pmc_pmcdisp[(R)] < 0) 112 113 #define PMC_MARK_ROW_FREE(R) do { \ 114 pmc_pmcdisp[(R)] = 0; \ 115 } while (0) 116 117 #define PMC_MARK_ROW_STANDALONE(R) do { \ 118 KASSERT(pmc_pmcdisp[(R)] <= 0, ("[pmc,%d] row disposition error", \ 119 __LINE__)); \ 120 atomic_add_int(&pmc_pmcdisp[(R)], -1); \ 121 KASSERT(pmc_pmcdisp[(R)] >= (-pmc_cpu_max_active()), \ 122 ("[pmc,%d] row disposition error", __LINE__)); \ 123 } while (0) 124 125 #define PMC_UNMARK_ROW_STANDALONE(R) do { \ 126 atomic_add_int(&pmc_pmcdisp[(R)], 1); \ 127 KASSERT(pmc_pmcdisp[(R)] <= 0, ("[pmc,%d] row disposition error", \ 128 __LINE__)); \ 129 } while (0) 130 131 #define PMC_MARK_ROW_THREAD(R) do { \ 132 KASSERT(pmc_pmcdisp[(R)] >= 0, ("[pmc,%d] row disposition error", \ 133 __LINE__)); \ 134 atomic_add_int(&pmc_pmcdisp[(R)], 1); \ 135 } while (0) 136 137 #define PMC_UNMARK_ROW_THREAD(R) do { \ 138 atomic_add_int(&pmc_pmcdisp[(R)], -1); \ 139 KASSERT(pmc_pmcdisp[(R)] >= 0, ("[pmc,%d] row disposition error", \ 140 __LINE__)); \ 141 } while (0) 142 143 144 /* various event handlers */ 145 static eventhandler_tag pmc_exit_tag, pmc_fork_tag, pmc_kld_load_tag, 146 pmc_kld_unload_tag; 147 148 /* Module statistics */ 149 struct pmc_driverstats pmc_stats; 150 151 152 /* Machine/processor dependent operations */ 153 static struct pmc_mdep *md; 154 155 /* 156 * Hash tables mapping owner processes and target threads to PMCs. 157 */ 158 159 struct mtx pmc_processhash_mtx; /* spin mutex */ 160 static u_long pmc_processhashmask; 161 static LIST_HEAD(pmc_processhash, pmc_process) *pmc_processhash; 162 163 /* 164 * Hash table of PMC owner descriptors. This table is protected by 165 * the shared PMC "sx" lock. 166 */ 167 168 static u_long pmc_ownerhashmask; 169 static LIST_HEAD(pmc_ownerhash, pmc_owner) *pmc_ownerhash; 170 171 /* 172 * List of PMC owners with system-wide sampling PMCs. 173 */ 174 175 static CK_LIST_HEAD(, pmc_owner) pmc_ss_owners; 176 177 /* 178 * List of free thread entries. This is protected by the spin 179 * mutex. 180 */ 181 static struct mtx pmc_threadfreelist_mtx; /* spin mutex */ 182 static LIST_HEAD(, pmc_thread) pmc_threadfreelist; 183 static int pmc_threadfreelist_entries=0; 184 #define THREADENTRY_SIZE \ 185 (sizeof(struct pmc_thread) + (md->pmd_npmc * sizeof(struct pmc_threadpmcstate))) 186 187 /* 188 * Task to free thread descriptors 189 */ 190 static struct task free_task; 191 192 /* 193 * A map of row indices to classdep structures. 194 */ 195 static struct pmc_classdep **pmc_rowindex_to_classdep; 196 197 /* 198 * Prototypes 199 */ 200 201 #ifdef HWPMC_DEBUG 202 static int pmc_debugflags_sysctl_handler(SYSCTL_HANDLER_ARGS); 203 static int pmc_debugflags_parse(char *newstr, char *fence); 204 #endif 205 206 static int load(struct module *module, int cmd, void *arg); 207 static int pmc_add_sample(ring_type_t ring, struct pmc *pm, struct trapframe *tf); 208 static void pmc_add_thread_descriptors_from_proc(struct proc *p, 209 struct pmc_process *pp); 210 static int pmc_attach_process(struct proc *p, struct pmc *pm); 211 static struct pmc *pmc_allocate_pmc_descriptor(void); 212 static struct pmc_owner *pmc_allocate_owner_descriptor(struct proc *p); 213 static int pmc_attach_one_process(struct proc *p, struct pmc *pm); 214 static int pmc_can_allocate_rowindex(struct proc *p, unsigned int ri, 215 int cpu); 216 static int pmc_can_attach(struct pmc *pm, struct proc *p); 217 static void pmc_capture_user_callchain(int cpu, int soft, struct trapframe *tf); 218 static void pmc_cleanup(void); 219 static int pmc_detach_process(struct proc *p, struct pmc *pm); 220 static int pmc_detach_one_process(struct proc *p, struct pmc *pm, 221 int flags); 222 static void pmc_destroy_owner_descriptor(struct pmc_owner *po); 223 static void pmc_destroy_pmc_descriptor(struct pmc *pm); 224 static void pmc_destroy_process_descriptor(struct pmc_process *pp); 225 static struct pmc_owner *pmc_find_owner_descriptor(struct proc *p); 226 static int pmc_find_pmc(pmc_id_t pmcid, struct pmc **pm); 227 static struct pmc *pmc_find_pmc_descriptor_in_process(struct pmc_owner *po, 228 pmc_id_t pmc); 229 static struct pmc_process *pmc_find_process_descriptor(struct proc *p, 230 uint32_t mode); 231 static struct pmc_thread *pmc_find_thread_descriptor(struct pmc_process *pp, 232 struct thread *td, uint32_t mode); 233 static void pmc_force_context_switch(void); 234 static void pmc_link_target_process(struct pmc *pm, 235 struct pmc_process *pp); 236 static void pmc_log_all_process_mappings(struct pmc_owner *po); 237 static void pmc_log_kernel_mappings(struct pmc *pm); 238 static void pmc_log_process_mappings(struct pmc_owner *po, struct proc *p); 239 static void pmc_maybe_remove_owner(struct pmc_owner *po); 240 static void pmc_process_csw_in(struct thread *td); 241 static void pmc_process_csw_out(struct thread *td); 242 static void pmc_process_exit(void *arg, struct proc *p); 243 static void pmc_process_fork(void *arg, struct proc *p1, 244 struct proc *p2, int n); 245 static void pmc_process_samples(int cpu, ring_type_t soft); 246 static void pmc_release_pmc_descriptor(struct pmc *pmc); 247 static void pmc_process_thread_add(struct thread *td); 248 static void pmc_process_thread_delete(struct thread *td); 249 static void pmc_process_thread_userret(struct thread *td); 250 static void pmc_remove_owner(struct pmc_owner *po); 251 static void pmc_remove_process_descriptor(struct pmc_process *pp); 252 static int pmc_start(struct pmc *pm); 253 static int pmc_stop(struct pmc *pm); 254 static int pmc_syscall_handler(struct thread *td, void *syscall_args); 255 static struct pmc_thread *pmc_thread_descriptor_pool_alloc(void); 256 static void pmc_thread_descriptor_pool_drain(void); 257 static void pmc_thread_descriptor_pool_free(struct pmc_thread *pt); 258 static void pmc_unlink_target_process(struct pmc *pmc, 259 struct pmc_process *pp); 260 static int generic_switch_in(struct pmc_cpu *pc, struct pmc_process *pp); 261 static int generic_switch_out(struct pmc_cpu *pc, struct pmc_process *pp); 262 static struct pmc_mdep *pmc_generic_cpu_initialize(void); 263 static void pmc_generic_cpu_finalize(struct pmc_mdep *md); 264 static void pmc_post_callchain_callback(void); 265 static void pmc_process_threadcreate(struct thread *td); 266 static void pmc_process_threadexit(struct thread *td); 267 static void pmc_process_proccreate(struct proc *p); 268 static void pmc_process_allproc(struct pmc *pm); 269 270 /* 271 * Kernel tunables and sysctl(8) interface. 272 */ 273 274 SYSCTL_DECL(_kern_hwpmc); 275 SYSCTL_NODE(_kern_hwpmc, OID_AUTO, stats, CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 276 "HWPMC stats"); 277 278 279 /* Stats. */ 280 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, intr_ignored, CTLFLAG_RW, 281 &pmc_stats.pm_intr_ignored, "# of interrupts ignored"); 282 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, intr_processed, CTLFLAG_RW, 283 &pmc_stats.pm_intr_processed, "# of interrupts processed"); 284 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, intr_bufferfull, CTLFLAG_RW, 285 &pmc_stats.pm_intr_bufferfull, "# of interrupts where buffer was full"); 286 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, syscalls, CTLFLAG_RW, 287 &pmc_stats.pm_syscalls, "# of syscalls"); 288 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, syscall_errors, CTLFLAG_RW, 289 &pmc_stats.pm_syscall_errors, "# of syscall_errors"); 290 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, buffer_requests, CTLFLAG_RW, 291 &pmc_stats.pm_buffer_requests, "# of buffer requests"); 292 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, buffer_requests_failed, CTLFLAG_RW, 293 &pmc_stats.pm_buffer_requests_failed, "# of buffer requests which failed"); 294 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, log_sweeps, CTLFLAG_RW, 295 &pmc_stats.pm_log_sweeps, "# of times samples were processed"); 296 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, merges, CTLFLAG_RW, 297 &pmc_stats.pm_merges, "# of times kernel stack was found for user trace"); 298 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, overwrites, CTLFLAG_RW, 299 &pmc_stats.pm_overwrites, "# of times a sample was overwritten before being logged"); 300 301 static int pmc_callchaindepth = PMC_CALLCHAIN_DEPTH; 302 SYSCTL_INT(_kern_hwpmc, OID_AUTO, callchaindepth, CTLFLAG_RDTUN, 303 &pmc_callchaindepth, 0, "depth of call chain records"); 304 305 char pmc_cpuid[PMC_CPUID_LEN]; 306 SYSCTL_STRING(_kern_hwpmc, OID_AUTO, cpuid, CTLFLAG_RD, 307 pmc_cpuid, 0, "cpu version string"); 308 #ifdef HWPMC_DEBUG 309 struct pmc_debugflags pmc_debugflags = PMC_DEBUG_DEFAULT_FLAGS; 310 char pmc_debugstr[PMC_DEBUG_STRSIZE]; 311 TUNABLE_STR(PMC_SYSCTL_NAME_PREFIX "debugflags", pmc_debugstr, 312 sizeof(pmc_debugstr)); 313 SYSCTL_PROC(_kern_hwpmc, OID_AUTO, debugflags, 314 CTLTYPE_STRING | CTLFLAG_RWTUN | CTLFLAG_NOFETCH | CTLFLAG_MPSAFE, 315 0, 0, pmc_debugflags_sysctl_handler, "A", 316 "debug flags"); 317 #endif 318 319 320 /* 321 * kern.hwpmc.hashrows -- determines the number of rows in the 322 * of the hash table used to look up threads 323 */ 324 325 static int pmc_hashsize = PMC_HASH_SIZE; 326 SYSCTL_INT(_kern_hwpmc, OID_AUTO, hashsize, CTLFLAG_RDTUN, 327 &pmc_hashsize, 0, "rows in hash tables"); 328 329 /* 330 * kern.hwpmc.nsamples --- number of PC samples/callchain stacks per CPU 331 */ 332 333 static int pmc_nsamples = PMC_NSAMPLES; 334 SYSCTL_INT(_kern_hwpmc, OID_AUTO, nsamples, CTLFLAG_RDTUN, 335 &pmc_nsamples, 0, "number of PC samples per CPU"); 336 337 static uint64_t pmc_sample_mask = PMC_NSAMPLES-1; 338 339 /* 340 * kern.hwpmc.mtxpoolsize -- number of mutexes in the mutex pool. 341 */ 342 343 static int pmc_mtxpool_size = PMC_MTXPOOL_SIZE; 344 SYSCTL_INT(_kern_hwpmc, OID_AUTO, mtxpoolsize, CTLFLAG_RDTUN, 345 &pmc_mtxpool_size, 0, "size of spin mutex pool"); 346 347 348 /* 349 * kern.hwpmc.threadfreelist_entries -- number of free entries 350 */ 351 352 SYSCTL_INT(_kern_hwpmc, OID_AUTO, threadfreelist_entries, CTLFLAG_RD, 353 &pmc_threadfreelist_entries, 0, "number of available thread entries"); 354 355 356 /* 357 * kern.hwpmc.threadfreelist_max -- maximum number of free entries 358 */ 359 360 static int pmc_threadfreelist_max = PMC_THREADLIST_MAX; 361 SYSCTL_INT(_kern_hwpmc, OID_AUTO, threadfreelist_max, CTLFLAG_RW, 362 &pmc_threadfreelist_max, 0, 363 "maximum number of available thread entries before freeing some"); 364 365 366 /* 367 * kern.hwpmc.mincount -- minimum sample count 368 */ 369 static u_int pmc_mincount = 1000; 370 SYSCTL_INT(_kern_hwpmc, OID_AUTO, mincount, CTLFLAG_RWTUN, 371 &pmc_mincount, 0, 372 "minimum count for sampling counters"); 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 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 pb->pb_priority = curthread->td_priority; 755 thread_unlock(curthread); 756 PMCDBG1(CPU,BND,2, "save-cpu cpu=%d", pb->pb_cpu); 757 } 758 759 /* 760 * restore the cpu binding of the current thread 761 */ 762 763 void 764 pmc_restore_cpu_binding(struct pmc_binding *pb) 765 { 766 PMCDBG2(CPU,BND,2, "restore-cpu curcpu=%d restore=%d", 767 curthread->td_oncpu, pb->pb_cpu); 768 thread_lock(curthread); 769 sched_bind(curthread, pb->pb_cpu); 770 if (!pb->pb_bound) 771 sched_unbind(curthread); 772 sched_prio(curthread, pb->pb_priority); 773 thread_unlock(curthread); 774 PMCDBG0(CPU,BND,2, "restore-cpu done"); 775 } 776 777 /* 778 * move execution over the specified cpu and bind it there. 779 */ 780 781 void 782 pmc_select_cpu(int cpu) 783 { 784 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 785 ("[pmc,%d] bad cpu number %d", __LINE__, cpu)); 786 787 /* Never move to an inactive CPU. */ 788 KASSERT(pmc_cpu_is_active(cpu), ("[pmc,%d] selecting inactive " 789 "CPU %d", __LINE__, cpu)); 790 791 PMCDBG1(CPU,SEL,2, "select-cpu cpu=%d", cpu); 792 thread_lock(curthread); 793 sched_prio(curthread, PRI_MIN); 794 sched_bind(curthread, cpu); 795 thread_unlock(curthread); 796 797 KASSERT(curthread->td_oncpu == cpu, 798 ("[pmc,%d] CPU not bound [cpu=%d, curr=%d]", __LINE__, 799 cpu, curthread->td_oncpu)); 800 801 PMCDBG1(CPU,SEL,2, "select-cpu cpu=%d ok", cpu); 802 } 803 804 /* 805 * Force a context switch. 806 * 807 * We do this by pause'ing for 1 tick -- invoking mi_switch() is not 808 * guaranteed to force a context switch. 809 */ 810 811 static void 812 pmc_force_context_switch(void) 813 { 814 815 pause("pmcctx", 1); 816 } 817 818 uint64_t 819 pmc_rdtsc(void) 820 { 821 #if defined(__i386__) || defined(__amd64__) 822 if (__predict_true(amd_feature & AMDID_RDTSCP)) 823 return rdtscp(); 824 else 825 return rdtsc(); 826 #else 827 return get_cyclecount(); 828 #endif 829 } 830 831 /* 832 * Get the file name for an executable. This is a simple wrapper 833 * around vn_fullpath(9). 834 */ 835 836 static void 837 pmc_getfilename(struct vnode *v, char **fullpath, char **freepath) 838 { 839 840 *fullpath = "unknown"; 841 *freepath = NULL; 842 vn_fullpath(v, fullpath, freepath); 843 } 844 845 /* 846 * remove an process owning PMCs 847 */ 848 849 void 850 pmc_remove_owner(struct pmc_owner *po) 851 { 852 struct pmc *pm, *tmp; 853 854 sx_assert(&pmc_sx, SX_XLOCKED); 855 856 PMCDBG1(OWN,ORM,1, "remove-owner po=%p", po); 857 858 /* Remove descriptor from the owner hash table */ 859 LIST_REMOVE(po, po_next); 860 861 /* release all owned PMC descriptors */ 862 LIST_FOREACH_SAFE(pm, &po->po_pmcs, pm_next, tmp) { 863 PMCDBG1(OWN,ORM,2, "pmc=%p", pm); 864 KASSERT(pm->pm_owner == po, 865 ("[pmc,%d] owner %p != po %p", __LINE__, pm->pm_owner, po)); 866 867 pmc_release_pmc_descriptor(pm); /* will unlink from the list */ 868 pmc_destroy_pmc_descriptor(pm); 869 } 870 871 KASSERT(po->po_sscount == 0, 872 ("[pmc,%d] SS count not zero", __LINE__)); 873 KASSERT(LIST_EMPTY(&po->po_pmcs), 874 ("[pmc,%d] PMC list not empty", __LINE__)); 875 876 /* de-configure the log file if present */ 877 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 878 pmclog_deconfigure_log(po); 879 } 880 881 /* 882 * remove an owner process record if all conditions are met. 883 */ 884 885 static void 886 pmc_maybe_remove_owner(struct pmc_owner *po) 887 { 888 889 PMCDBG1(OWN,OMR,1, "maybe-remove-owner po=%p", po); 890 891 /* 892 * Remove owner record if 893 * - this process does not own any PMCs 894 * - this process has not allocated a system-wide sampling buffer 895 */ 896 897 if (LIST_EMPTY(&po->po_pmcs) && 898 ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0)) { 899 pmc_remove_owner(po); 900 pmc_destroy_owner_descriptor(po); 901 } 902 } 903 904 /* 905 * Add an association between a target process and a PMC. 906 */ 907 908 static void 909 pmc_link_target_process(struct pmc *pm, struct pmc_process *pp) 910 { 911 int ri; 912 struct pmc_target *pt; 913 #ifdef INVARIANTS 914 struct pmc_thread *pt_td; 915 #endif 916 917 sx_assert(&pmc_sx, SX_XLOCKED); 918 919 KASSERT(pm != NULL && pp != NULL, 920 ("[pmc,%d] Null pm %p or pp %p", __LINE__, pm, pp)); 921 KASSERT(PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)), 922 ("[pmc,%d] Attaching a non-process-virtual pmc=%p to pid=%d", 923 __LINE__, pm, pp->pp_proc->p_pid)); 924 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= ((int) md->pmd_npmc - 1), 925 ("[pmc,%d] Illegal reference count %d for process record %p", 926 __LINE__, pp->pp_refcnt, (void *) pp)); 927 928 ri = PMC_TO_ROWINDEX(pm); 929 930 PMCDBG3(PRC,TLK,1, "link-target pmc=%p ri=%d pmc-process=%p", 931 pm, ri, pp); 932 933 #ifdef HWPMC_DEBUG 934 LIST_FOREACH(pt, &pm->pm_targets, pt_next) 935 if (pt->pt_process == pp) 936 KASSERT(0, ("[pmc,%d] pp %p already in pmc %p targets", 937 __LINE__, pp, pm)); 938 #endif 939 940 pt = malloc(sizeof(struct pmc_target), M_PMC, M_WAITOK|M_ZERO); 941 pt->pt_process = pp; 942 943 LIST_INSERT_HEAD(&pm->pm_targets, pt, pt_next); 944 945 atomic_store_rel_ptr((uintptr_t *)&pp->pp_pmcs[ri].pp_pmc, 946 (uintptr_t)pm); 947 948 if (pm->pm_owner->po_owner == pp->pp_proc) 949 pm->pm_flags |= PMC_F_ATTACHED_TO_OWNER; 950 951 /* 952 * Initialize the per-process values at this row index. 953 */ 954 pp->pp_pmcs[ri].pp_pmcval = PMC_TO_MODE(pm) == PMC_MODE_TS ? 955 pm->pm_sc.pm_reloadcount : 0; 956 957 pp->pp_refcnt++; 958 959 #ifdef INVARIANTS 960 /* Confirm that the per-thread values at this row index are cleared. */ 961 if (PMC_TO_MODE(pm) == PMC_MODE_TS) { 962 mtx_lock_spin(pp->pp_tdslock); 963 LIST_FOREACH(pt_td, &pp->pp_tds, pt_next) { 964 KASSERT(pt_td->pt_pmcs[ri].pt_pmcval == (pmc_value_t) 0, 965 ("[pmc,%d] pt_pmcval not cleared for pid=%d at " 966 "ri=%d", __LINE__, pp->pp_proc->p_pid, ri)); 967 } 968 mtx_unlock_spin(pp->pp_tdslock); 969 } 970 #endif 971 } 972 973 /* 974 * Removes the association between a target process and a PMC. 975 */ 976 977 static void 978 pmc_unlink_target_process(struct pmc *pm, struct pmc_process *pp) 979 { 980 int ri; 981 struct proc *p; 982 struct pmc_target *ptgt; 983 struct pmc_thread *pt; 984 985 sx_assert(&pmc_sx, SX_XLOCKED); 986 987 KASSERT(pm != NULL && pp != NULL, 988 ("[pmc,%d] Null pm %p or pp %p", __LINE__, pm, pp)); 989 990 KASSERT(pp->pp_refcnt >= 1 && pp->pp_refcnt <= (int) md->pmd_npmc, 991 ("[pmc,%d] Illegal ref count %d on process record %p", 992 __LINE__, pp->pp_refcnt, (void *) pp)); 993 994 ri = PMC_TO_ROWINDEX(pm); 995 996 PMCDBG3(PRC,TUL,1, "unlink-target pmc=%p ri=%d pmc-process=%p", 997 pm, ri, pp); 998 999 KASSERT(pp->pp_pmcs[ri].pp_pmc == pm, 1000 ("[pmc,%d] PMC ri %d mismatch pmc %p pp->[ri] %p", __LINE__, 1001 ri, pm, pp->pp_pmcs[ri].pp_pmc)); 1002 1003 pp->pp_pmcs[ri].pp_pmc = NULL; 1004 pp->pp_pmcs[ri].pp_pmcval = (pmc_value_t) 0; 1005 1006 /* Clear the per-thread values at this row index. */ 1007 if (PMC_TO_MODE(pm) == PMC_MODE_TS) { 1008 mtx_lock_spin(pp->pp_tdslock); 1009 LIST_FOREACH(pt, &pp->pp_tds, pt_next) 1010 pt->pt_pmcs[ri].pt_pmcval = (pmc_value_t) 0; 1011 mtx_unlock_spin(pp->pp_tdslock); 1012 } 1013 1014 /* Remove owner-specific flags */ 1015 if (pm->pm_owner->po_owner == pp->pp_proc) { 1016 pp->pp_flags &= ~PMC_PP_ENABLE_MSR_ACCESS; 1017 pm->pm_flags &= ~PMC_F_ATTACHED_TO_OWNER; 1018 } 1019 1020 pp->pp_refcnt--; 1021 1022 /* Remove the target process from the PMC structure */ 1023 LIST_FOREACH(ptgt, &pm->pm_targets, pt_next) 1024 if (ptgt->pt_process == pp) 1025 break; 1026 1027 KASSERT(ptgt != NULL, ("[pmc,%d] process %p (pp: %p) not found " 1028 "in pmc %p", __LINE__, pp->pp_proc, pp, pm)); 1029 1030 LIST_REMOVE(ptgt, pt_next); 1031 free(ptgt, M_PMC); 1032 1033 /* if the PMC now lacks targets, send the owner a SIGIO */ 1034 if (LIST_EMPTY(&pm->pm_targets)) { 1035 p = pm->pm_owner->po_owner; 1036 PROC_LOCK(p); 1037 kern_psignal(p, SIGIO); 1038 PROC_UNLOCK(p); 1039 1040 PMCDBG2(PRC,SIG,2, "signalling proc=%p signal=%d", p, 1041 SIGIO); 1042 } 1043 } 1044 1045 /* 1046 * Check if PMC 'pm' may be attached to target process 't'. 1047 */ 1048 1049 static int 1050 pmc_can_attach(struct pmc *pm, struct proc *t) 1051 { 1052 struct proc *o; /* pmc owner */ 1053 struct ucred *oc, *tc; /* owner, target credentials */ 1054 int decline_attach, i; 1055 1056 /* 1057 * A PMC's owner can always attach that PMC to itself. 1058 */ 1059 1060 if ((o = pm->pm_owner->po_owner) == t) 1061 return 0; 1062 1063 PROC_LOCK(o); 1064 oc = o->p_ucred; 1065 crhold(oc); 1066 PROC_UNLOCK(o); 1067 1068 PROC_LOCK(t); 1069 tc = t->p_ucred; 1070 crhold(tc); 1071 PROC_UNLOCK(t); 1072 1073 /* 1074 * The effective uid of the PMC owner should match at least one 1075 * of the {effective,real,saved} uids of the target process. 1076 */ 1077 1078 decline_attach = oc->cr_uid != tc->cr_uid && 1079 oc->cr_uid != tc->cr_svuid && 1080 oc->cr_uid != tc->cr_ruid; 1081 1082 /* 1083 * Every one of the target's group ids, must be in the owner's 1084 * group list. 1085 */ 1086 for (i = 0; !decline_attach && i < tc->cr_ngroups; i++) 1087 decline_attach = !groupmember(tc->cr_groups[i], oc); 1088 1089 /* check the read and saved gids too */ 1090 if (decline_attach == 0) 1091 decline_attach = !groupmember(tc->cr_rgid, oc) || 1092 !groupmember(tc->cr_svgid, oc); 1093 1094 crfree(tc); 1095 crfree(oc); 1096 1097 return !decline_attach; 1098 } 1099 1100 /* 1101 * Attach a process to a PMC. 1102 */ 1103 1104 static int 1105 pmc_attach_one_process(struct proc *p, struct pmc *pm) 1106 { 1107 int ri, error; 1108 char *fullpath, *freepath; 1109 struct pmc_process *pp; 1110 1111 sx_assert(&pmc_sx, SX_XLOCKED); 1112 1113 PMCDBG5(PRC,ATT,2, "attach-one pm=%p ri=%d proc=%p (%d, %s)", pm, 1114 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 1115 1116 /* 1117 * Locate the process descriptor corresponding to process 'p', 1118 * allocating space as needed. 1119 * 1120 * Verify that rowindex 'pm_rowindex' is free in the process 1121 * descriptor. 1122 * 1123 * If not, allocate space for a descriptor and link the 1124 * process descriptor and PMC. 1125 */ 1126 ri = PMC_TO_ROWINDEX(pm); 1127 1128 /* mark process as using HWPMCs */ 1129 PROC_LOCK(p); 1130 p->p_flag |= P_HWPMC; 1131 PROC_UNLOCK(p); 1132 1133 if ((pp = pmc_find_process_descriptor(p, PMC_FLAG_ALLOCATE)) == NULL) { 1134 error = ENOMEM; 1135 goto fail; 1136 } 1137 1138 if (pp->pp_pmcs[ri].pp_pmc == pm) {/* already present at slot [ri] */ 1139 error = EEXIST; 1140 goto fail; 1141 } 1142 1143 if (pp->pp_pmcs[ri].pp_pmc != NULL) { 1144 error = EBUSY; 1145 goto fail; 1146 } 1147 1148 pmc_link_target_process(pm, pp); 1149 1150 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)) && 1151 (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) == 0) 1152 pm->pm_flags |= PMC_F_NEEDS_LOGFILE; 1153 1154 pm->pm_flags |= PMC_F_ATTACH_DONE; /* mark as attached */ 1155 1156 /* issue an attach event to a configured log file */ 1157 if (pm->pm_owner->po_flags & PMC_PO_OWNS_LOGFILE) { 1158 if (p->p_flag & P_KPROC) { 1159 fullpath = kernelname; 1160 freepath = NULL; 1161 } else { 1162 pmc_getfilename(p->p_textvp, &fullpath, &freepath); 1163 pmclog_process_pmcattach(pm, p->p_pid, fullpath); 1164 } 1165 free(freepath, M_TEMP); 1166 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 1167 pmc_log_process_mappings(pm->pm_owner, p); 1168 } 1169 1170 return (0); 1171 fail: 1172 PROC_LOCK(p); 1173 p->p_flag &= ~P_HWPMC; 1174 PROC_UNLOCK(p); 1175 return (error); 1176 } 1177 1178 /* 1179 * Attach a process and optionally its children 1180 */ 1181 1182 static int 1183 pmc_attach_process(struct proc *p, struct pmc *pm) 1184 { 1185 int error; 1186 struct proc *top; 1187 1188 sx_assert(&pmc_sx, SX_XLOCKED); 1189 1190 PMCDBG5(PRC,ATT,1, "attach pm=%p ri=%d proc=%p (%d, %s)", pm, 1191 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 1192 1193 1194 /* 1195 * If this PMC successfully allowed a GETMSR operation 1196 * in the past, disallow further ATTACHes. 1197 */ 1198 1199 if ((pm->pm_flags & PMC_PP_ENABLE_MSR_ACCESS) != 0) 1200 return EPERM; 1201 1202 if ((pm->pm_flags & PMC_F_DESCENDANTS) == 0) 1203 return pmc_attach_one_process(p, pm); 1204 1205 /* 1206 * Traverse all child processes, attaching them to 1207 * this PMC. 1208 */ 1209 1210 sx_slock(&proctree_lock); 1211 1212 top = p; 1213 1214 for (;;) { 1215 if ((error = pmc_attach_one_process(p, pm)) != 0) 1216 break; 1217 if (!LIST_EMPTY(&p->p_children)) 1218 p = LIST_FIRST(&p->p_children); 1219 else for (;;) { 1220 if (p == top) 1221 goto done; 1222 if (LIST_NEXT(p, p_sibling)) { 1223 p = LIST_NEXT(p, p_sibling); 1224 break; 1225 } 1226 p = p->p_pptr; 1227 } 1228 } 1229 1230 if (error) 1231 (void) pmc_detach_process(top, pm); 1232 1233 done: 1234 sx_sunlock(&proctree_lock); 1235 return error; 1236 } 1237 1238 /* 1239 * Detach a process from a PMC. If there are no other PMCs tracking 1240 * this process, remove the process structure from its hash table. If 1241 * 'flags' contains PMC_FLAG_REMOVE, then free the process structure. 1242 */ 1243 1244 static int 1245 pmc_detach_one_process(struct proc *p, struct pmc *pm, int flags) 1246 { 1247 int ri; 1248 struct pmc_process *pp; 1249 1250 sx_assert(&pmc_sx, SX_XLOCKED); 1251 1252 KASSERT(pm != NULL, 1253 ("[pmc,%d] null pm pointer", __LINE__)); 1254 1255 ri = PMC_TO_ROWINDEX(pm); 1256 1257 PMCDBG6(PRC,ATT,2, "detach-one pm=%p ri=%d proc=%p (%d, %s) flags=0x%x", 1258 pm, ri, p, p->p_pid, p->p_comm, flags); 1259 1260 if ((pp = pmc_find_process_descriptor(p, 0)) == NULL) 1261 return ESRCH; 1262 1263 if (pp->pp_pmcs[ri].pp_pmc != pm) 1264 return EINVAL; 1265 1266 pmc_unlink_target_process(pm, pp); 1267 1268 /* Issue a detach entry if a log file is configured */ 1269 if (pm->pm_owner->po_flags & PMC_PO_OWNS_LOGFILE) 1270 pmclog_process_pmcdetach(pm, p->p_pid); 1271 1272 /* 1273 * If there are no PMCs targeting this process, we remove its 1274 * descriptor from the target hash table and unset the P_HWPMC 1275 * flag in the struct proc. 1276 */ 1277 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= (int) md->pmd_npmc, 1278 ("[pmc,%d] Illegal refcnt %d for process struct %p", 1279 __LINE__, pp->pp_refcnt, pp)); 1280 1281 if (pp->pp_refcnt != 0) /* still a target of some PMC */ 1282 return 0; 1283 1284 pmc_remove_process_descriptor(pp); 1285 1286 if (flags & PMC_FLAG_REMOVE) 1287 pmc_destroy_process_descriptor(pp); 1288 1289 PROC_LOCK(p); 1290 p->p_flag &= ~P_HWPMC; 1291 PROC_UNLOCK(p); 1292 1293 return 0; 1294 } 1295 1296 /* 1297 * Detach a process and optionally its descendants from a PMC. 1298 */ 1299 1300 static int 1301 pmc_detach_process(struct proc *p, struct pmc *pm) 1302 { 1303 struct proc *top; 1304 1305 sx_assert(&pmc_sx, SX_XLOCKED); 1306 1307 PMCDBG5(PRC,ATT,1, "detach pm=%p ri=%d proc=%p (%d, %s)", pm, 1308 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 1309 1310 if ((pm->pm_flags & PMC_F_DESCENDANTS) == 0) 1311 return pmc_detach_one_process(p, pm, PMC_FLAG_REMOVE); 1312 1313 /* 1314 * Traverse all children, detaching them from this PMC. We 1315 * ignore errors since we could be detaching a PMC from a 1316 * partially attached proc tree. 1317 */ 1318 1319 sx_slock(&proctree_lock); 1320 1321 top = p; 1322 1323 for (;;) { 1324 (void) pmc_detach_one_process(p, pm, PMC_FLAG_REMOVE); 1325 1326 if (!LIST_EMPTY(&p->p_children)) 1327 p = LIST_FIRST(&p->p_children); 1328 else for (;;) { 1329 if (p == top) 1330 goto done; 1331 if (LIST_NEXT(p, p_sibling)) { 1332 p = LIST_NEXT(p, p_sibling); 1333 break; 1334 } 1335 p = p->p_pptr; 1336 } 1337 } 1338 1339 done: 1340 sx_sunlock(&proctree_lock); 1341 1342 if (LIST_EMPTY(&pm->pm_targets)) 1343 pm->pm_flags &= ~PMC_F_ATTACH_DONE; 1344 1345 return 0; 1346 } 1347 1348 1349 /* 1350 * Thread context switch IN 1351 */ 1352 1353 static void 1354 pmc_process_csw_in(struct thread *td) 1355 { 1356 int cpu; 1357 unsigned int adjri, ri; 1358 struct pmc *pm; 1359 struct proc *p; 1360 struct pmc_cpu *pc; 1361 struct pmc_hw *phw __diagused; 1362 pmc_value_t newvalue; 1363 struct pmc_process *pp; 1364 struct pmc_thread *pt; 1365 struct pmc_classdep *pcd; 1366 1367 p = td->td_proc; 1368 pt = NULL; 1369 if ((pp = pmc_find_process_descriptor(p, PMC_FLAG_NONE)) == NULL) 1370 return; 1371 1372 KASSERT(pp->pp_proc == td->td_proc, 1373 ("[pmc,%d] not my thread state", __LINE__)); 1374 1375 critical_enter(); /* no preemption from this point */ 1376 1377 cpu = PCPU_GET(cpuid); /* td->td_oncpu is invalid */ 1378 1379 PMCDBG5(CSW,SWI,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p, 1380 p->p_pid, p->p_comm, pp); 1381 1382 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 1383 ("[pmc,%d] weird CPU id %d", __LINE__, cpu)); 1384 1385 pc = pmc_pcpu[cpu]; 1386 1387 for (ri = 0; ri < md->pmd_npmc; ri++) { 1388 1389 if ((pm = pp->pp_pmcs[ri].pp_pmc) == NULL) 1390 continue; 1391 1392 KASSERT(PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)), 1393 ("[pmc,%d] Target PMC in non-virtual mode (%d)", 1394 __LINE__, PMC_TO_MODE(pm))); 1395 1396 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 1397 ("[pmc,%d] Row index mismatch pmc %d != ri %d", 1398 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 1399 1400 /* 1401 * Only PMCs that are marked as 'RUNNING' need 1402 * be placed on hardware. 1403 */ 1404 1405 if (pm->pm_state != PMC_STATE_RUNNING) 1406 continue; 1407 1408 KASSERT(counter_u64_fetch(pm->pm_runcount) >= 0, 1409 ("[pmc,%d] pm=%p runcount %ld", __LINE__, (void *) pm, 1410 (unsigned long)counter_u64_fetch(pm->pm_runcount))); 1411 1412 /* increment PMC runcount */ 1413 counter_u64_add(pm->pm_runcount, 1); 1414 1415 /* configure the HWPMC we are going to use. */ 1416 pcd = pmc_ri_to_classdep(md, ri, &adjri); 1417 pcd->pcd_config_pmc(cpu, adjri, pm); 1418 1419 phw = pc->pc_hwpmcs[ri]; 1420 1421 KASSERT(phw != NULL, 1422 ("[pmc,%d] null hw pointer", __LINE__)); 1423 1424 KASSERT(phw->phw_pmc == pm, 1425 ("[pmc,%d] hw->pmc %p != pmc %p", __LINE__, 1426 phw->phw_pmc, pm)); 1427 1428 /* 1429 * Write out saved value and start the PMC. 1430 * 1431 * Sampling PMCs use a per-thread value, while 1432 * counting mode PMCs use a per-pmc value that is 1433 * inherited across descendants. 1434 */ 1435 if (PMC_TO_MODE(pm) == PMC_MODE_TS) { 1436 if (pt == NULL) 1437 pt = pmc_find_thread_descriptor(pp, td, 1438 PMC_FLAG_NONE); 1439 1440 KASSERT(pt != NULL, 1441 ("[pmc,%d] No thread found for td=%p", __LINE__, 1442 td)); 1443 1444 mtx_pool_lock_spin(pmc_mtxpool, pm); 1445 1446 /* 1447 * If we have a thread descriptor, use the per-thread 1448 * counter in the descriptor. If not, we will use 1449 * a per-process counter. 1450 * 1451 * TODO: Remove the per-process "safety net" once 1452 * we have thoroughly tested that we don't hit the 1453 * above assert. 1454 */ 1455 if (pt != NULL) { 1456 if (pt->pt_pmcs[ri].pt_pmcval > 0) 1457 newvalue = pt->pt_pmcs[ri].pt_pmcval; 1458 else 1459 newvalue = pm->pm_sc.pm_reloadcount; 1460 } else { 1461 /* 1462 * Use the saved value calculated after the most 1463 * recent time a thread using the shared counter 1464 * switched out. Reset the saved count in case 1465 * another thread from this process switches in 1466 * before any threads switch out. 1467 */ 1468 1469 newvalue = pp->pp_pmcs[ri].pp_pmcval; 1470 pp->pp_pmcs[ri].pp_pmcval = 1471 pm->pm_sc.pm_reloadcount; 1472 } 1473 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1474 KASSERT(newvalue > 0 && newvalue <= 1475 pm->pm_sc.pm_reloadcount, 1476 ("[pmc,%d] pmcval outside of expected range cpu=%d " 1477 "ri=%d pmcval=%jx pm_reloadcount=%jx", __LINE__, 1478 cpu, ri, newvalue, pm->pm_sc.pm_reloadcount)); 1479 } else { 1480 KASSERT(PMC_TO_MODE(pm) == PMC_MODE_TC, 1481 ("[pmc,%d] illegal mode=%d", __LINE__, 1482 PMC_TO_MODE(pm))); 1483 mtx_pool_lock_spin(pmc_mtxpool, pm); 1484 newvalue = PMC_PCPU_SAVED(cpu, ri) = 1485 pm->pm_gv.pm_savedvalue; 1486 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1487 } 1488 1489 PMCDBG3(CSW,SWI,1,"cpu=%d ri=%d new=%jd", cpu, ri, newvalue); 1490 1491 pcd->pcd_write_pmc(cpu, adjri, newvalue); 1492 1493 /* If a sampling mode PMC, reset stalled state. */ 1494 if (PMC_TO_MODE(pm) == PMC_MODE_TS) 1495 pm->pm_pcpu_state[cpu].pps_stalled = 0; 1496 1497 /* Indicate that we desire this to run. */ 1498 pm->pm_pcpu_state[cpu].pps_cpustate = 1; 1499 1500 /* Start the PMC. */ 1501 pcd->pcd_start_pmc(cpu, adjri); 1502 } 1503 1504 /* 1505 * perform any other architecture/cpu dependent thread 1506 * switch-in actions. 1507 */ 1508 1509 (void) (*md->pmd_switch_in)(pc, pp); 1510 1511 critical_exit(); 1512 1513 } 1514 1515 /* 1516 * Thread context switch OUT. 1517 */ 1518 1519 static void 1520 pmc_process_csw_out(struct thread *td) 1521 { 1522 int cpu; 1523 int64_t tmp; 1524 struct pmc *pm; 1525 struct proc *p; 1526 enum pmc_mode mode; 1527 struct pmc_cpu *pc; 1528 pmc_value_t newvalue; 1529 unsigned int adjri, ri; 1530 struct pmc_process *pp; 1531 struct pmc_thread *pt = NULL; 1532 struct pmc_classdep *pcd; 1533 1534 1535 /* 1536 * Locate our process descriptor; this may be NULL if 1537 * this process is exiting and we have already removed 1538 * the process from the target process table. 1539 * 1540 * Note that due to kernel preemption, multiple 1541 * context switches may happen while the process is 1542 * exiting. 1543 * 1544 * Note also that if the target process cannot be 1545 * found we still need to deconfigure any PMCs that 1546 * are currently running on hardware. 1547 */ 1548 1549 p = td->td_proc; 1550 pp = pmc_find_process_descriptor(p, PMC_FLAG_NONE); 1551 1552 /* 1553 * save PMCs 1554 */ 1555 1556 critical_enter(); 1557 1558 cpu = PCPU_GET(cpuid); /* td->td_oncpu is invalid */ 1559 1560 PMCDBG5(CSW,SWO,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p, 1561 p->p_pid, p->p_comm, pp); 1562 1563 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 1564 ("[pmc,%d weird CPU id %d", __LINE__, cpu)); 1565 1566 pc = pmc_pcpu[cpu]; 1567 1568 /* 1569 * When a PMC gets unlinked from a target PMC, it will 1570 * be removed from the target's pp_pmc[] array. 1571 * 1572 * However, on a MP system, the target could have been 1573 * executing on another CPU at the time of the unlink. 1574 * So, at context switch OUT time, we need to look at 1575 * the hardware to determine if a PMC is scheduled on 1576 * it. 1577 */ 1578 1579 for (ri = 0; ri < md->pmd_npmc; ri++) { 1580 1581 pcd = pmc_ri_to_classdep(md, ri, &adjri); 1582 pm = NULL; 1583 (void) (*pcd->pcd_get_config)(cpu, adjri, &pm); 1584 1585 if (pm == NULL) /* nothing at this row index */ 1586 continue; 1587 1588 mode = PMC_TO_MODE(pm); 1589 if (!PMC_IS_VIRTUAL_MODE(mode)) 1590 continue; /* not a process virtual PMC */ 1591 1592 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 1593 ("[pmc,%d] ri mismatch pmc(%d) ri(%d)", 1594 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 1595 1596 /* 1597 * Change desired state, and then stop if not stalled. 1598 * This two-step dance should avoid race conditions where 1599 * an interrupt re-enables the PMC after this code has 1600 * already checked the pm_stalled flag. 1601 */ 1602 pm->pm_pcpu_state[cpu].pps_cpustate = 0; 1603 if (pm->pm_pcpu_state[cpu].pps_stalled == 0) 1604 pcd->pcd_stop_pmc(cpu, adjri); 1605 1606 KASSERT(counter_u64_fetch(pm->pm_runcount) > 0, 1607 ("[pmc,%d] pm=%p runcount %ld", __LINE__, (void *) pm, 1608 (unsigned long)counter_u64_fetch(pm->pm_runcount))); 1609 1610 /* reduce this PMC's runcount */ 1611 counter_u64_add(pm->pm_runcount, -1); 1612 1613 /* 1614 * If this PMC is associated with this process, 1615 * save the reading. 1616 */ 1617 1618 if (pm->pm_state != PMC_STATE_DELETED && pp != NULL && 1619 pp->pp_pmcs[ri].pp_pmc != NULL) { 1620 KASSERT(pm == pp->pp_pmcs[ri].pp_pmc, 1621 ("[pmc,%d] pm %p != pp_pmcs[%d] %p", __LINE__, 1622 pm, ri, pp->pp_pmcs[ri].pp_pmc)); 1623 1624 KASSERT(pp->pp_refcnt > 0, 1625 ("[pmc,%d] pp refcnt = %d", __LINE__, 1626 pp->pp_refcnt)); 1627 1628 pcd->pcd_read_pmc(cpu, adjri, &newvalue); 1629 1630 if (mode == PMC_MODE_TS) { 1631 PMCDBG3(CSW,SWO,1,"cpu=%d ri=%d val=%jd (samp)", 1632 cpu, ri, newvalue); 1633 1634 if (pt == NULL) 1635 pt = pmc_find_thread_descriptor(pp, td, 1636 PMC_FLAG_NONE); 1637 1638 KASSERT(pt != NULL, 1639 ("[pmc,%d] No thread found for td=%p", 1640 __LINE__, td)); 1641 1642 mtx_pool_lock_spin(pmc_mtxpool, pm); 1643 1644 /* 1645 * If we have a thread descriptor, save the 1646 * per-thread counter in the descriptor. If not, 1647 * we will update the per-process counter. 1648 * 1649 * TODO: Remove the per-process "safety net" 1650 * once we have thoroughly tested that we 1651 * don't hit the above assert. 1652 */ 1653 if (pt != NULL) 1654 pt->pt_pmcs[ri].pt_pmcval = newvalue; 1655 else { 1656 /* 1657 * For sampling process-virtual PMCs, 1658 * newvalue is the number of events to 1659 * be seen until the next sampling 1660 * interrupt. We can just add the events 1661 * left from this invocation to the 1662 * counter, then adjust in case we 1663 * overflow our range. 1664 * 1665 * (Recall that we reload the counter 1666 * every time we use it.) 1667 */ 1668 pp->pp_pmcs[ri].pp_pmcval += newvalue; 1669 if (pp->pp_pmcs[ri].pp_pmcval > 1670 pm->pm_sc.pm_reloadcount) 1671 pp->pp_pmcs[ri].pp_pmcval -= 1672 pm->pm_sc.pm_reloadcount; 1673 } 1674 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1675 } else { 1676 tmp = newvalue - PMC_PCPU_SAVED(cpu,ri); 1677 1678 PMCDBG3(CSW,SWO,1,"cpu=%d ri=%d tmp=%jd (count)", 1679 cpu, ri, tmp); 1680 1681 /* 1682 * For counting process-virtual PMCs, 1683 * we expect the count to be 1684 * increasing monotonically, modulo a 64 1685 * bit wraparound. 1686 */ 1687 KASSERT(tmp >= 0, 1688 ("[pmc,%d] negative increment cpu=%d " 1689 "ri=%d newvalue=%jx saved=%jx " 1690 "incr=%jx", __LINE__, cpu, ri, 1691 newvalue, PMC_PCPU_SAVED(cpu,ri), tmp)); 1692 1693 mtx_pool_lock_spin(pmc_mtxpool, pm); 1694 pm->pm_gv.pm_savedvalue += tmp; 1695 pp->pp_pmcs[ri].pp_pmcval += tmp; 1696 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1697 1698 if (pm->pm_flags & PMC_F_LOG_PROCCSW) 1699 pmclog_process_proccsw(pm, pp, tmp, td); 1700 } 1701 } 1702 1703 /* mark hardware as free */ 1704 pcd->pcd_config_pmc(cpu, adjri, NULL); 1705 } 1706 1707 /* 1708 * perform any other architecture/cpu dependent thread 1709 * switch out functions. 1710 */ 1711 1712 (void) (*md->pmd_switch_out)(pc, pp); 1713 1714 critical_exit(); 1715 } 1716 1717 /* 1718 * A new thread for a process. 1719 */ 1720 static void 1721 pmc_process_thread_add(struct thread *td) 1722 { 1723 struct pmc_process *pmc; 1724 1725 pmc = pmc_find_process_descriptor(td->td_proc, PMC_FLAG_NONE); 1726 if (pmc != NULL) 1727 pmc_find_thread_descriptor(pmc, td, PMC_FLAG_ALLOCATE); 1728 } 1729 1730 /* 1731 * A thread delete for a process. 1732 */ 1733 static void 1734 pmc_process_thread_delete(struct thread *td) 1735 { 1736 struct pmc_process *pmc; 1737 1738 pmc = pmc_find_process_descriptor(td->td_proc, PMC_FLAG_NONE); 1739 if (pmc != NULL) 1740 pmc_thread_descriptor_pool_free(pmc_find_thread_descriptor(pmc, 1741 td, PMC_FLAG_REMOVE)); 1742 } 1743 1744 /* 1745 * A userret() call for a thread. 1746 */ 1747 static void 1748 pmc_process_thread_userret(struct thread *td) 1749 { 1750 sched_pin(); 1751 pmc_capture_user_callchain(curcpu, PMC_UR, td->td_frame); 1752 sched_unpin(); 1753 } 1754 1755 /* 1756 * A mapping change for a process. 1757 */ 1758 1759 static void 1760 pmc_process_mmap(struct thread *td, struct pmckern_map_in *pkm) 1761 { 1762 int ri; 1763 pid_t pid; 1764 char *fullpath, *freepath; 1765 const struct pmc *pm; 1766 struct pmc_owner *po; 1767 const struct pmc_process *pp; 1768 1769 freepath = fullpath = NULL; 1770 MPASS(!in_epoch(global_epoch_preempt)); 1771 pmc_getfilename((struct vnode *) pkm->pm_file, &fullpath, &freepath); 1772 1773 pid = td->td_proc->p_pid; 1774 1775 PMC_EPOCH_ENTER(); 1776 /* Inform owners of all system-wide sampling PMCs. */ 1777 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1778 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1779 pmclog_process_map_in(po, pid, pkm->pm_address, fullpath); 1780 1781 if ((pp = pmc_find_process_descriptor(td->td_proc, 0)) == NULL) 1782 goto done; 1783 1784 /* 1785 * Inform sampling PMC owners tracking this process. 1786 */ 1787 for (ri = 0; ri < md->pmd_npmc; ri++) 1788 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL && 1789 PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 1790 pmclog_process_map_in(pm->pm_owner, 1791 pid, pkm->pm_address, fullpath); 1792 1793 done: 1794 if (freepath) 1795 free(freepath, M_TEMP); 1796 PMC_EPOCH_EXIT(); 1797 } 1798 1799 1800 /* 1801 * Log an munmap request. 1802 */ 1803 1804 static void 1805 pmc_process_munmap(struct thread *td, struct pmckern_map_out *pkm) 1806 { 1807 int ri; 1808 pid_t pid; 1809 struct pmc_owner *po; 1810 const struct pmc *pm; 1811 const struct pmc_process *pp; 1812 1813 pid = td->td_proc->p_pid; 1814 1815 PMC_EPOCH_ENTER(); 1816 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1817 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1818 pmclog_process_map_out(po, pid, pkm->pm_address, 1819 pkm->pm_address + pkm->pm_size); 1820 PMC_EPOCH_EXIT(); 1821 1822 if ((pp = pmc_find_process_descriptor(td->td_proc, 0)) == NULL) 1823 return; 1824 1825 for (ri = 0; ri < md->pmd_npmc; ri++) 1826 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL && 1827 PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 1828 pmclog_process_map_out(pm->pm_owner, pid, 1829 pkm->pm_address, pkm->pm_address + pkm->pm_size); 1830 } 1831 1832 /* 1833 * Log mapping information about the kernel. 1834 */ 1835 1836 static void 1837 pmc_log_kernel_mappings(struct pmc *pm) 1838 { 1839 struct pmc_owner *po; 1840 struct pmckern_map_in *km, *kmbase; 1841 1842 MPASS(in_epoch(global_epoch_preempt) || sx_xlocked(&pmc_sx)); 1843 KASSERT(PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)), 1844 ("[pmc,%d] non-sampling PMC (%p) desires mapping information", 1845 __LINE__, (void *) pm)); 1846 1847 po = pm->pm_owner; 1848 1849 if (po->po_flags & PMC_PO_INITIAL_MAPPINGS_DONE) 1850 return; 1851 if (PMC_TO_MODE(pm) == PMC_MODE_SS) 1852 pmc_process_allproc(pm); 1853 /* 1854 * Log the current set of kernel modules. 1855 */ 1856 kmbase = linker_hwpmc_list_objects(); 1857 for (km = kmbase; km->pm_file != NULL; km++) { 1858 PMCDBG2(LOG,REG,1,"%s %p", (char *) km->pm_file, 1859 (void *) km->pm_address); 1860 pmclog_process_map_in(po, (pid_t) -1, km->pm_address, 1861 km->pm_file); 1862 } 1863 free(kmbase, M_LINKER); 1864 1865 po->po_flags |= PMC_PO_INITIAL_MAPPINGS_DONE; 1866 } 1867 1868 /* 1869 * Log the mappings for a single process. 1870 */ 1871 1872 static void 1873 pmc_log_process_mappings(struct pmc_owner *po, struct proc *p) 1874 { 1875 vm_map_t map; 1876 struct vnode *vp; 1877 struct vmspace *vm; 1878 vm_map_entry_t entry; 1879 vm_offset_t last_end; 1880 u_int last_timestamp; 1881 struct vnode *last_vp; 1882 vm_offset_t start_addr; 1883 vm_object_t obj, lobj, tobj; 1884 char *fullpath, *freepath; 1885 1886 last_vp = NULL; 1887 last_end = (vm_offset_t) 0; 1888 fullpath = freepath = NULL; 1889 1890 if ((vm = vmspace_acquire_ref(p)) == NULL) 1891 return; 1892 1893 map = &vm->vm_map; 1894 vm_map_lock_read(map); 1895 1896 VM_MAP_ENTRY_FOREACH(entry, map) { 1897 1898 if (entry == NULL) { 1899 PMCDBG2(LOG,OPS,2, "hwpmc: vm_map entry unexpectedly " 1900 "NULL! pid=%d vm_map=%p\n", p->p_pid, map); 1901 break; 1902 } 1903 1904 /* 1905 * We only care about executable map entries. 1906 */ 1907 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) || 1908 !(entry->protection & VM_PROT_EXECUTE) || 1909 (entry->object.vm_object == NULL)) { 1910 continue; 1911 } 1912 1913 obj = entry->object.vm_object; 1914 VM_OBJECT_RLOCK(obj); 1915 1916 /* 1917 * Walk the backing_object list to find the base 1918 * (non-shadowed) vm_object. 1919 */ 1920 for (lobj = tobj = obj; tobj != NULL; tobj = tobj->backing_object) { 1921 if (tobj != obj) 1922 VM_OBJECT_RLOCK(tobj); 1923 if (lobj != obj) 1924 VM_OBJECT_RUNLOCK(lobj); 1925 lobj = tobj; 1926 } 1927 1928 /* 1929 * At this point lobj is the base vm_object and it is locked. 1930 */ 1931 if (lobj == NULL) { 1932 PMCDBG3(LOG,OPS,2, "hwpmc: lobj unexpectedly NULL! pid=%d " 1933 "vm_map=%p vm_obj=%p\n", p->p_pid, map, obj); 1934 VM_OBJECT_RUNLOCK(obj); 1935 continue; 1936 } 1937 1938 vp = vm_object_vnode(lobj); 1939 if (vp == NULL) { 1940 if (lobj != obj) 1941 VM_OBJECT_RUNLOCK(lobj); 1942 VM_OBJECT_RUNLOCK(obj); 1943 continue; 1944 } 1945 1946 /* 1947 * Skip contiguous regions that point to the same 1948 * vnode, so we don't emit redundant MAP-IN 1949 * directives. 1950 */ 1951 if (entry->start == last_end && vp == last_vp) { 1952 last_end = entry->end; 1953 if (lobj != obj) 1954 VM_OBJECT_RUNLOCK(lobj); 1955 VM_OBJECT_RUNLOCK(obj); 1956 continue; 1957 } 1958 1959 /* 1960 * We don't want to keep the proc's vm_map or this 1961 * vm_object locked while we walk the pathname, since 1962 * vn_fullpath() can sleep. However, if we drop the 1963 * lock, it's possible for concurrent activity to 1964 * modify the vm_map list. To protect against this, 1965 * we save the vm_map timestamp before we release the 1966 * lock, and check it after we reacquire the lock 1967 * below. 1968 */ 1969 start_addr = entry->start; 1970 last_end = entry->end; 1971 last_timestamp = map->timestamp; 1972 vm_map_unlock_read(map); 1973 1974 vref(vp); 1975 if (lobj != obj) 1976 VM_OBJECT_RUNLOCK(lobj); 1977 1978 VM_OBJECT_RUNLOCK(obj); 1979 1980 freepath = NULL; 1981 pmc_getfilename(vp, &fullpath, &freepath); 1982 last_vp = vp; 1983 1984 vrele(vp); 1985 1986 vp = NULL; 1987 pmclog_process_map_in(po, p->p_pid, start_addr, fullpath); 1988 if (freepath) 1989 free(freepath, M_TEMP); 1990 1991 vm_map_lock_read(map); 1992 1993 /* 1994 * If our saved timestamp doesn't match, this means 1995 * that the vm_map was modified out from under us and 1996 * we can't trust our current "entry" pointer. Do a 1997 * new lookup for this entry. If there is no entry 1998 * for this address range, vm_map_lookup_entry() will 1999 * return the previous one, so we always want to go to 2000 * the next entry on the next loop iteration. 2001 * 2002 * There is an edge condition here that can occur if 2003 * there is no entry at or before this address. In 2004 * this situation, vm_map_lookup_entry returns 2005 * &map->header, which would cause our loop to abort 2006 * without processing the rest of the map. However, 2007 * in practice this will never happen for process 2008 * vm_map. This is because the executable's text 2009 * segment is the first mapping in the proc's address 2010 * space, and this mapping is never removed until the 2011 * process exits, so there will always be a non-header 2012 * entry at or before the requested address for 2013 * vm_map_lookup_entry to return. 2014 */ 2015 if (map->timestamp != last_timestamp) 2016 vm_map_lookup_entry(map, last_end - 1, &entry); 2017 } 2018 2019 vm_map_unlock_read(map); 2020 vmspace_free(vm); 2021 return; 2022 } 2023 2024 /* 2025 * Log mappings for all processes in the system. 2026 */ 2027 2028 static void 2029 pmc_log_all_process_mappings(struct pmc_owner *po) 2030 { 2031 struct proc *p, *top; 2032 2033 sx_assert(&pmc_sx, SX_XLOCKED); 2034 2035 if ((p = pfind(1)) == NULL) 2036 panic("[pmc,%d] Cannot find init", __LINE__); 2037 2038 PROC_UNLOCK(p); 2039 2040 sx_slock(&proctree_lock); 2041 2042 top = p; 2043 2044 for (;;) { 2045 pmc_log_process_mappings(po, p); 2046 if (!LIST_EMPTY(&p->p_children)) 2047 p = LIST_FIRST(&p->p_children); 2048 else for (;;) { 2049 if (p == top) 2050 goto done; 2051 if (LIST_NEXT(p, p_sibling)) { 2052 p = LIST_NEXT(p, p_sibling); 2053 break; 2054 } 2055 p = p->p_pptr; 2056 } 2057 } 2058 done: 2059 sx_sunlock(&proctree_lock); 2060 } 2061 2062 /* 2063 * The 'hook' invoked from the kernel proper 2064 */ 2065 2066 2067 #ifdef HWPMC_DEBUG 2068 const char *pmc_hooknames[] = { 2069 /* these strings correspond to PMC_FN_* in <sys/pmckern.h> */ 2070 "", 2071 "EXEC", 2072 "CSW-IN", 2073 "CSW-OUT", 2074 "SAMPLE", 2075 "UNUSED1", 2076 "UNUSED2", 2077 "MMAP", 2078 "MUNMAP", 2079 "CALLCHAIN-NMI", 2080 "CALLCHAIN-SOFT", 2081 "SOFTSAMPLING", 2082 "THR-CREATE", 2083 "THR-EXIT", 2084 "THR-USERRET", 2085 "THR-CREATE-LOG", 2086 "THR-EXIT-LOG", 2087 "PROC-CREATE-LOG" 2088 }; 2089 #endif 2090 2091 static int 2092 pmc_hook_handler(struct thread *td, int function, void *arg) 2093 { 2094 int cpu; 2095 2096 PMCDBG4(MOD,PMH,1, "hook td=%p func=%d \"%s\" arg=%p", td, function, 2097 pmc_hooknames[function], arg); 2098 2099 switch (function) 2100 { 2101 2102 /* 2103 * Process exec() 2104 */ 2105 2106 case PMC_FN_PROCESS_EXEC: 2107 { 2108 char *fullpath, *freepath; 2109 unsigned int ri; 2110 int is_using_hwpmcs; 2111 struct pmc *pm; 2112 struct proc *p; 2113 struct pmc_owner *po; 2114 struct pmc_process *pp; 2115 struct pmckern_procexec *pk; 2116 2117 sx_assert(&pmc_sx, SX_XLOCKED); 2118 2119 p = td->td_proc; 2120 pmc_getfilename(p->p_textvp, &fullpath, &freepath); 2121 2122 pk = (struct pmckern_procexec *) arg; 2123 2124 PMC_EPOCH_ENTER(); 2125 /* Inform owners of SS mode PMCs of the exec event. */ 2126 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 2127 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 2128 pmclog_process_procexec(po, PMC_ID_INVALID, 2129 p->p_pid, pk->pm_entryaddr, fullpath); 2130 PMC_EPOCH_EXIT(); 2131 2132 PROC_LOCK(p); 2133 is_using_hwpmcs = p->p_flag & P_HWPMC; 2134 PROC_UNLOCK(p); 2135 2136 if (!is_using_hwpmcs) { 2137 if (freepath) 2138 free(freepath, M_TEMP); 2139 break; 2140 } 2141 2142 /* 2143 * PMCs are not inherited across an exec(): remove any 2144 * PMCs that this process is the owner of. 2145 */ 2146 2147 if ((po = pmc_find_owner_descriptor(p)) != NULL) { 2148 pmc_remove_owner(po); 2149 pmc_destroy_owner_descriptor(po); 2150 } 2151 2152 /* 2153 * If the process being exec'ed is not the target of any 2154 * PMC, we are done. 2155 */ 2156 if ((pp = pmc_find_process_descriptor(p, 0)) == NULL) { 2157 if (freepath) 2158 free(freepath, M_TEMP); 2159 break; 2160 } 2161 2162 /* 2163 * Log the exec event to all monitoring owners. Skip 2164 * owners who have already received the event because 2165 * they had system sampling PMCs active. 2166 */ 2167 for (ri = 0; ri < md->pmd_npmc; ri++) 2168 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) { 2169 po = pm->pm_owner; 2170 if (po->po_sscount == 0 && 2171 po->po_flags & PMC_PO_OWNS_LOGFILE) 2172 pmclog_process_procexec(po, pm->pm_id, 2173 p->p_pid, pk->pm_entryaddr, 2174 fullpath); 2175 } 2176 2177 if (freepath) 2178 free(freepath, M_TEMP); 2179 2180 2181 PMCDBG4(PRC,EXC,1, "exec proc=%p (%d, %s) cred-changed=%d", 2182 p, p->p_pid, p->p_comm, pk->pm_credentialschanged); 2183 2184 if (pk->pm_credentialschanged == 0) /* no change */ 2185 break; 2186 2187 /* 2188 * If the newly exec()'ed process has a different credential 2189 * than before, allow it to be the target of a PMC only if 2190 * the PMC's owner has sufficient privilege. 2191 */ 2192 2193 for (ri = 0; ri < md->pmd_npmc; ri++) 2194 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) 2195 if (pmc_can_attach(pm, td->td_proc) != 0) 2196 pmc_detach_one_process(td->td_proc, 2197 pm, PMC_FLAG_NONE); 2198 2199 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= (int) md->pmd_npmc, 2200 ("[pmc,%d] Illegal ref count %d on pp %p", __LINE__, 2201 pp->pp_refcnt, pp)); 2202 2203 /* 2204 * If this process is no longer the target of any 2205 * PMCs, we can remove the process entry and free 2206 * up space. 2207 */ 2208 2209 if (pp->pp_refcnt == 0) { 2210 pmc_remove_process_descriptor(pp); 2211 pmc_destroy_process_descriptor(pp); 2212 break; 2213 } 2214 2215 } 2216 break; 2217 2218 case PMC_FN_CSW_IN: 2219 pmc_process_csw_in(td); 2220 break; 2221 2222 case PMC_FN_CSW_OUT: 2223 pmc_process_csw_out(td); 2224 break; 2225 2226 /* 2227 * Process accumulated PC samples. 2228 * 2229 * This function is expected to be called by hardclock() for 2230 * each CPU that has accumulated PC samples. 2231 * 2232 * This function is to be executed on the CPU whose samples 2233 * are being processed. 2234 */ 2235 case PMC_FN_DO_SAMPLES: 2236 2237 /* 2238 * Clear the cpu specific bit in the CPU mask before 2239 * do the rest of the processing. If the NMI handler 2240 * gets invoked after the "atomic_clear_int()" call 2241 * below but before "pmc_process_samples()" gets 2242 * around to processing the interrupt, then we will 2243 * come back here at the next hardclock() tick (and 2244 * may find nothing to do if "pmc_process_samples()" 2245 * had already processed the interrupt). We don't 2246 * lose the interrupt sample. 2247 */ 2248 DPCPU_SET(pmc_sampled, 0); 2249 cpu = PCPU_GET(cpuid); 2250 pmc_process_samples(cpu, PMC_HR); 2251 pmc_process_samples(cpu, PMC_SR); 2252 pmc_process_samples(cpu, PMC_UR); 2253 break; 2254 2255 case PMC_FN_MMAP: 2256 pmc_process_mmap(td, (struct pmckern_map_in *) arg); 2257 break; 2258 2259 case PMC_FN_MUNMAP: 2260 MPASS(in_epoch(global_epoch_preempt) || sx_xlocked(&pmc_sx)); 2261 pmc_process_munmap(td, (struct pmckern_map_out *) arg); 2262 break; 2263 2264 case PMC_FN_PROC_CREATE_LOG: 2265 pmc_process_proccreate((struct proc *)arg); 2266 break; 2267 2268 case PMC_FN_USER_CALLCHAIN: 2269 /* 2270 * Record a call chain. 2271 */ 2272 KASSERT(td == curthread, ("[pmc,%d] td != curthread", 2273 __LINE__)); 2274 2275 pmc_capture_user_callchain(PCPU_GET(cpuid), PMC_HR, 2276 (struct trapframe *) arg); 2277 2278 KASSERT(td->td_pinned == 1, 2279 ("[pmc,%d] invalid td_pinned value", __LINE__)); 2280 sched_unpin(); /* Can migrate safely now. */ 2281 2282 td->td_pflags &= ~TDP_CALLCHAIN; 2283 break; 2284 2285 case PMC_FN_USER_CALLCHAIN_SOFT: 2286 /* 2287 * Record a call chain. 2288 */ 2289 KASSERT(td == curthread, ("[pmc,%d] td != curthread", 2290 __LINE__)); 2291 2292 cpu = PCPU_GET(cpuid); 2293 pmc_capture_user_callchain(cpu, PMC_SR, 2294 (struct trapframe *) arg); 2295 2296 KASSERT(td->td_pinned == 1, 2297 ("[pmc,%d] invalid td_pinned value", __LINE__)); 2298 2299 sched_unpin(); /* Can migrate safely now. */ 2300 2301 td->td_pflags &= ~TDP_CALLCHAIN; 2302 break; 2303 2304 case PMC_FN_SOFT_SAMPLING: 2305 /* 2306 * Call soft PMC sampling intr. 2307 */ 2308 pmc_soft_intr((struct pmckern_soft *) arg); 2309 break; 2310 2311 case PMC_FN_THR_CREATE: 2312 pmc_process_thread_add(td); 2313 pmc_process_threadcreate(td); 2314 break; 2315 2316 case PMC_FN_THR_CREATE_LOG: 2317 pmc_process_threadcreate(td); 2318 break; 2319 2320 case PMC_FN_THR_EXIT: 2321 KASSERT(td == curthread, ("[pmc,%d] td != curthread", 2322 __LINE__)); 2323 pmc_process_thread_delete(td); 2324 pmc_process_threadexit(td); 2325 break; 2326 case PMC_FN_THR_EXIT_LOG: 2327 pmc_process_threadexit(td); 2328 break; 2329 case PMC_FN_THR_USERRET: 2330 KASSERT(td == curthread, ("[pmc,%d] td != curthread", 2331 __LINE__)); 2332 pmc_process_thread_userret(td); 2333 break; 2334 2335 default: 2336 #ifdef HWPMC_DEBUG 2337 KASSERT(0, ("[pmc,%d] unknown hook %d\n", __LINE__, function)); 2338 #endif 2339 break; 2340 2341 } 2342 2343 return 0; 2344 } 2345 2346 /* 2347 * allocate a 'struct pmc_owner' descriptor in the owner hash table. 2348 */ 2349 2350 static struct pmc_owner * 2351 pmc_allocate_owner_descriptor(struct proc *p) 2352 { 2353 uint32_t hindex; 2354 struct pmc_owner *po; 2355 struct pmc_ownerhash *poh; 2356 2357 hindex = PMC_HASH_PTR(p, pmc_ownerhashmask); 2358 poh = &pmc_ownerhash[hindex]; 2359 2360 /* allocate space for N pointers and one descriptor struct */ 2361 po = malloc(sizeof(struct pmc_owner), M_PMC, M_WAITOK|M_ZERO); 2362 po->po_owner = p; 2363 LIST_INSERT_HEAD(poh, po, po_next); /* insert into hash table */ 2364 2365 TAILQ_INIT(&po->po_logbuffers); 2366 mtx_init(&po->po_mtx, "pmc-owner-mtx", "pmc-per-proc", MTX_SPIN); 2367 2368 PMCDBG4(OWN,ALL,1, "allocate-owner proc=%p (%d, %s) pmc-owner=%p", 2369 p, p->p_pid, p->p_comm, po); 2370 2371 return po; 2372 } 2373 2374 static void 2375 pmc_destroy_owner_descriptor(struct pmc_owner *po) 2376 { 2377 2378 PMCDBG4(OWN,REL,1, "destroy-owner po=%p proc=%p (%d, %s)", 2379 po, po->po_owner, po->po_owner->p_pid, po->po_owner->p_comm); 2380 2381 mtx_destroy(&po->po_mtx); 2382 free(po, M_PMC); 2383 } 2384 2385 /* 2386 * Allocate a thread descriptor from the free pool. 2387 * 2388 * NOTE: This *can* return NULL. 2389 */ 2390 static struct pmc_thread * 2391 pmc_thread_descriptor_pool_alloc(void) 2392 { 2393 struct pmc_thread *pt; 2394 2395 mtx_lock_spin(&pmc_threadfreelist_mtx); 2396 if ((pt = LIST_FIRST(&pmc_threadfreelist)) != NULL) { 2397 LIST_REMOVE(pt, pt_next); 2398 pmc_threadfreelist_entries--; 2399 } 2400 mtx_unlock_spin(&pmc_threadfreelist_mtx); 2401 2402 return (pt); 2403 } 2404 2405 /* 2406 * Add a thread descriptor to the free pool. We use this instead of free() 2407 * to maintain a cache of free entries. Additionally, we can safely call 2408 * this function when we cannot call free(), such as in a critical section. 2409 * 2410 */ 2411 static void 2412 pmc_thread_descriptor_pool_free(struct pmc_thread *pt) 2413 { 2414 2415 if (pt == NULL) 2416 return; 2417 2418 memset(pt, 0, THREADENTRY_SIZE); 2419 mtx_lock_spin(&pmc_threadfreelist_mtx); 2420 LIST_INSERT_HEAD(&pmc_threadfreelist, pt, pt_next); 2421 pmc_threadfreelist_entries++; 2422 if (pmc_threadfreelist_entries > pmc_threadfreelist_max) 2423 taskqueue_enqueue(taskqueue_fast, &free_task); 2424 mtx_unlock_spin(&pmc_threadfreelist_mtx); 2425 } 2426 2427 /* 2428 * An asynchronous task to manage the free list. 2429 */ 2430 static void 2431 pmc_thread_descriptor_pool_free_task(void *arg __unused, int pending __unused) 2432 { 2433 struct pmc_thread *pt; 2434 LIST_HEAD(, pmc_thread) tmplist; 2435 int delta; 2436 2437 LIST_INIT(&tmplist); 2438 2439 /* Determine what changes, if any, we need to make. */ 2440 mtx_lock_spin(&pmc_threadfreelist_mtx); 2441 delta = pmc_threadfreelist_entries - pmc_threadfreelist_max; 2442 while (delta > 0 && (pt = LIST_FIRST(&pmc_threadfreelist)) != NULL) { 2443 delta--; 2444 pmc_threadfreelist_entries--; 2445 LIST_REMOVE(pt, pt_next); 2446 LIST_INSERT_HEAD(&tmplist, pt, pt_next); 2447 } 2448 mtx_unlock_spin(&pmc_threadfreelist_mtx); 2449 2450 /* If there are entries to free, free them. */ 2451 while (!LIST_EMPTY(&tmplist)) { 2452 pt = LIST_FIRST(&tmplist); 2453 LIST_REMOVE(pt, pt_next); 2454 free(pt, M_PMC); 2455 } 2456 } 2457 2458 /* 2459 * Drain the thread free pool, freeing all allocations. 2460 */ 2461 static void 2462 pmc_thread_descriptor_pool_drain(void) 2463 { 2464 struct pmc_thread *pt, *next; 2465 2466 LIST_FOREACH_SAFE(pt, &pmc_threadfreelist, pt_next, next) { 2467 LIST_REMOVE(pt, pt_next); 2468 free(pt, M_PMC); 2469 } 2470 } 2471 2472 /* 2473 * find the descriptor corresponding to thread 'td', adding or removing it 2474 * as specified by 'mode'. 2475 * 2476 * Note that this supports additional mode flags in addition to those 2477 * supported by pmc_find_process_descriptor(): 2478 * PMC_FLAG_NOWAIT: Causes the function to not wait for mallocs. 2479 * This makes it safe to call while holding certain other locks. 2480 */ 2481 2482 static struct pmc_thread * 2483 pmc_find_thread_descriptor(struct pmc_process *pp, struct thread *td, 2484 uint32_t mode) 2485 { 2486 struct pmc_thread *pt = NULL, *ptnew = NULL; 2487 int wait_flag; 2488 2489 KASSERT(td != NULL, ("[pmc,%d] called to add NULL td", __LINE__)); 2490 2491 /* 2492 * Pre-allocate memory in the PMC_FLAG_ALLOCATE case prior to 2493 * acquiring the lock. 2494 */ 2495 if (mode & PMC_FLAG_ALLOCATE) { 2496 if ((ptnew = pmc_thread_descriptor_pool_alloc()) == NULL) { 2497 wait_flag = M_WAITOK; 2498 if ((mode & PMC_FLAG_NOWAIT) || in_epoch(global_epoch_preempt)) 2499 wait_flag = M_NOWAIT; 2500 2501 ptnew = malloc(THREADENTRY_SIZE, M_PMC, 2502 wait_flag|M_ZERO); 2503 } 2504 } 2505 2506 mtx_lock_spin(pp->pp_tdslock); 2507 2508 LIST_FOREACH(pt, &pp->pp_tds, pt_next) 2509 if (pt->pt_td == td) 2510 break; 2511 2512 if ((mode & PMC_FLAG_REMOVE) && pt != NULL) 2513 LIST_REMOVE(pt, pt_next); 2514 2515 if ((mode & PMC_FLAG_ALLOCATE) && pt == NULL && ptnew != NULL) { 2516 pt = ptnew; 2517 ptnew = NULL; 2518 pt->pt_td = td; 2519 LIST_INSERT_HEAD(&pp->pp_tds, pt, pt_next); 2520 } 2521 2522 mtx_unlock_spin(pp->pp_tdslock); 2523 2524 if (ptnew != NULL) { 2525 free(ptnew, M_PMC); 2526 } 2527 2528 return pt; 2529 } 2530 2531 /* 2532 * Try to add thread descriptors for each thread in a process. 2533 */ 2534 2535 static void 2536 pmc_add_thread_descriptors_from_proc(struct proc *p, struct pmc_process *pp) 2537 { 2538 struct thread *curtd; 2539 struct pmc_thread **tdlist; 2540 int i, tdcnt, tdlistsz; 2541 2542 KASSERT(!PROC_LOCKED(p), ("[pmc,%d] proc unexpectedly locked", 2543 __LINE__)); 2544 tdcnt = 32; 2545 restart: 2546 tdlistsz = roundup2(tdcnt, 32); 2547 2548 tdcnt = 0; 2549 tdlist = malloc(sizeof(struct pmc_thread*) * tdlistsz, M_TEMP, M_WAITOK); 2550 2551 PROC_LOCK(p); 2552 FOREACH_THREAD_IN_PROC(p, curtd) 2553 tdcnt++; 2554 if (tdcnt >= tdlistsz) { 2555 PROC_UNLOCK(p); 2556 free(tdlist, M_TEMP); 2557 goto restart; 2558 } 2559 /* 2560 * Try to add each thread to the list without sleeping. If unable, 2561 * add to a queue to retry after dropping the process lock. 2562 */ 2563 tdcnt = 0; 2564 FOREACH_THREAD_IN_PROC(p, curtd) { 2565 tdlist[tdcnt] = pmc_find_thread_descriptor(pp, curtd, 2566 PMC_FLAG_ALLOCATE|PMC_FLAG_NOWAIT); 2567 if (tdlist[tdcnt] == NULL) { 2568 PROC_UNLOCK(p); 2569 for (i = 0; i <= tdcnt; i++) 2570 pmc_thread_descriptor_pool_free(tdlist[i]); 2571 free(tdlist, M_TEMP); 2572 goto restart; 2573 } 2574 tdcnt++; 2575 } 2576 PROC_UNLOCK(p); 2577 free(tdlist, M_TEMP); 2578 } 2579 2580 /* 2581 * find the descriptor corresponding to process 'p', adding or removing it 2582 * as specified by 'mode'. 2583 */ 2584 2585 static struct pmc_process * 2586 pmc_find_process_descriptor(struct proc *p, uint32_t mode) 2587 { 2588 uint32_t hindex; 2589 struct pmc_process *pp, *ppnew; 2590 struct pmc_processhash *pph; 2591 2592 hindex = PMC_HASH_PTR(p, pmc_processhashmask); 2593 pph = &pmc_processhash[hindex]; 2594 2595 ppnew = NULL; 2596 2597 /* 2598 * Pre-allocate memory in the PMC_FLAG_ALLOCATE case since we 2599 * cannot call malloc(9) once we hold a spin lock. 2600 */ 2601 if (mode & PMC_FLAG_ALLOCATE) 2602 ppnew = malloc(sizeof(struct pmc_process) + md->pmd_npmc * 2603 sizeof(struct pmc_targetstate), M_PMC, M_WAITOK|M_ZERO); 2604 2605 mtx_lock_spin(&pmc_processhash_mtx); 2606 LIST_FOREACH(pp, pph, pp_next) 2607 if (pp->pp_proc == p) 2608 break; 2609 2610 if ((mode & PMC_FLAG_REMOVE) && pp != NULL) 2611 LIST_REMOVE(pp, pp_next); 2612 2613 if ((mode & PMC_FLAG_ALLOCATE) && pp == NULL && 2614 ppnew != NULL) { 2615 ppnew->pp_proc = p; 2616 LIST_INIT(&ppnew->pp_tds); 2617 ppnew->pp_tdslock = mtx_pool_find(pmc_mtxpool, ppnew); 2618 LIST_INSERT_HEAD(pph, ppnew, pp_next); 2619 mtx_unlock_spin(&pmc_processhash_mtx); 2620 pp = ppnew; 2621 ppnew = NULL; 2622 2623 /* Add thread descriptors for this process' current threads. */ 2624 pmc_add_thread_descriptors_from_proc(p, pp); 2625 } 2626 else 2627 mtx_unlock_spin(&pmc_processhash_mtx); 2628 2629 if (ppnew != NULL) 2630 free(ppnew, M_PMC); 2631 2632 return pp; 2633 } 2634 2635 /* 2636 * remove a process descriptor from the process hash table. 2637 */ 2638 2639 static void 2640 pmc_remove_process_descriptor(struct pmc_process *pp) 2641 { 2642 KASSERT(pp->pp_refcnt == 0, 2643 ("[pmc,%d] Removing process descriptor %p with count %d", 2644 __LINE__, pp, pp->pp_refcnt)); 2645 2646 mtx_lock_spin(&pmc_processhash_mtx); 2647 LIST_REMOVE(pp, pp_next); 2648 mtx_unlock_spin(&pmc_processhash_mtx); 2649 } 2650 2651 /* 2652 * destroy a process descriptor. 2653 */ 2654 2655 static void 2656 pmc_destroy_process_descriptor(struct pmc_process *pp) 2657 { 2658 struct pmc_thread *pmc_td; 2659 2660 while ((pmc_td = LIST_FIRST(&pp->pp_tds)) != NULL) { 2661 LIST_REMOVE(pmc_td, pt_next); 2662 pmc_thread_descriptor_pool_free(pmc_td); 2663 } 2664 free(pp, M_PMC); 2665 } 2666 2667 2668 /* 2669 * find an owner descriptor corresponding to proc 'p' 2670 */ 2671 2672 static struct pmc_owner * 2673 pmc_find_owner_descriptor(struct proc *p) 2674 { 2675 uint32_t hindex; 2676 struct pmc_owner *po; 2677 struct pmc_ownerhash *poh; 2678 2679 hindex = PMC_HASH_PTR(p, pmc_ownerhashmask); 2680 poh = &pmc_ownerhash[hindex]; 2681 2682 po = NULL; 2683 LIST_FOREACH(po, poh, po_next) 2684 if (po->po_owner == p) 2685 break; 2686 2687 PMCDBG5(OWN,FND,1, "find-owner proc=%p (%d, %s) hindex=0x%x -> " 2688 "pmc-owner=%p", p, p->p_pid, p->p_comm, hindex, po); 2689 2690 return po; 2691 } 2692 2693 /* 2694 * pmc_allocate_pmc_descriptor 2695 * 2696 * Allocate a pmc descriptor and initialize its 2697 * fields. 2698 */ 2699 2700 static struct pmc * 2701 pmc_allocate_pmc_descriptor(void) 2702 { 2703 struct pmc *pmc; 2704 2705 pmc = malloc(sizeof(struct pmc), M_PMC, M_WAITOK|M_ZERO); 2706 pmc->pm_runcount = counter_u64_alloc(M_WAITOK); 2707 pmc->pm_pcpu_state = malloc(sizeof(struct pmc_pcpu_state)*mp_ncpus, M_PMC, M_WAITOK|M_ZERO); 2708 PMCDBG1(PMC,ALL,1, "allocate-pmc -> pmc=%p", pmc); 2709 2710 return pmc; 2711 } 2712 2713 /* 2714 * Destroy a pmc descriptor. 2715 */ 2716 2717 static void 2718 pmc_destroy_pmc_descriptor(struct pmc *pm) 2719 { 2720 2721 KASSERT(pm->pm_state == PMC_STATE_DELETED || 2722 pm->pm_state == PMC_STATE_FREE, 2723 ("[pmc,%d] destroying non-deleted PMC", __LINE__)); 2724 KASSERT(LIST_EMPTY(&pm->pm_targets), 2725 ("[pmc,%d] destroying pmc with targets", __LINE__)); 2726 KASSERT(pm->pm_owner == NULL, 2727 ("[pmc,%d] destroying pmc attached to an owner", __LINE__)); 2728 KASSERT(counter_u64_fetch(pm->pm_runcount) == 0, 2729 ("[pmc,%d] pmc has non-zero run count %ld", __LINE__, 2730 (unsigned long)counter_u64_fetch(pm->pm_runcount))); 2731 2732 counter_u64_free(pm->pm_runcount); 2733 free(pm->pm_pcpu_state, M_PMC); 2734 free(pm, M_PMC); 2735 } 2736 2737 static void 2738 pmc_wait_for_pmc_idle(struct pmc *pm) 2739 { 2740 #ifdef INVARIANTS 2741 volatile int maxloop; 2742 2743 maxloop = 100 * pmc_cpu_max(); 2744 #endif 2745 /* 2746 * Loop (with a forced context switch) till the PMC's runcount 2747 * comes down to zero. 2748 */ 2749 pmclog_flush(pm->pm_owner, 1); 2750 while (counter_u64_fetch(pm->pm_runcount) > 0) { 2751 pmclog_flush(pm->pm_owner, 1); 2752 #ifdef INVARIANTS 2753 maxloop--; 2754 KASSERT(maxloop > 0, 2755 ("[pmc,%d] (ri%d, rc%ld) waiting too long for " 2756 "pmc to be free", __LINE__, 2757 PMC_TO_ROWINDEX(pm), (unsigned long)counter_u64_fetch(pm->pm_runcount))); 2758 #endif 2759 pmc_force_context_switch(); 2760 } 2761 } 2762 2763 /* 2764 * This function does the following things: 2765 * 2766 * - detaches the PMC from hardware 2767 * - unlinks all target threads that were attached to it 2768 * - removes the PMC from its owner's list 2769 * - destroys the PMC private mutex 2770 * 2771 * Once this function completes, the given pmc pointer can be freed by 2772 * calling pmc_destroy_pmc_descriptor(). 2773 */ 2774 2775 static void 2776 pmc_release_pmc_descriptor(struct pmc *pm) 2777 { 2778 enum pmc_mode mode; 2779 struct pmc_hw *phw __diagused; 2780 u_int adjri, ri, cpu; 2781 struct pmc_owner *po; 2782 struct pmc_binding pb; 2783 struct pmc_process *pp; 2784 struct pmc_classdep *pcd; 2785 struct pmc_target *ptgt, *tmp; 2786 2787 sx_assert(&pmc_sx, SX_XLOCKED); 2788 2789 KASSERT(pm, ("[pmc,%d] null pmc", __LINE__)); 2790 2791 ri = PMC_TO_ROWINDEX(pm); 2792 pcd = pmc_ri_to_classdep(md, ri, &adjri); 2793 mode = PMC_TO_MODE(pm); 2794 2795 PMCDBG3(PMC,REL,1, "release-pmc pmc=%p ri=%d mode=%d", pm, ri, 2796 mode); 2797 2798 /* 2799 * First, we take the PMC off hardware. 2800 */ 2801 cpu = 0; 2802 if (PMC_IS_SYSTEM_MODE(mode)) { 2803 2804 /* 2805 * A system mode PMC runs on a specific CPU. Switch 2806 * to this CPU and turn hardware off. 2807 */ 2808 pmc_save_cpu_binding(&pb); 2809 2810 cpu = PMC_TO_CPU(pm); 2811 2812 pmc_select_cpu(cpu); 2813 2814 /* switch off non-stalled CPUs */ 2815 pm->pm_pcpu_state[cpu].pps_cpustate = 0; 2816 if (pm->pm_state == PMC_STATE_RUNNING && 2817 pm->pm_pcpu_state[cpu].pps_stalled == 0) { 2818 2819 phw = pmc_pcpu[cpu]->pc_hwpmcs[ri]; 2820 2821 KASSERT(phw->phw_pmc == pm, 2822 ("[pmc, %d] pmc ptr ri(%d) hw(%p) pm(%p)", 2823 __LINE__, ri, phw->phw_pmc, pm)); 2824 PMCDBG2(PMC,REL,2, "stopping cpu=%d ri=%d", cpu, ri); 2825 2826 critical_enter(); 2827 pcd->pcd_stop_pmc(cpu, adjri); 2828 critical_exit(); 2829 } 2830 2831 PMCDBG2(PMC,REL,2, "decfg cpu=%d ri=%d", cpu, ri); 2832 2833 critical_enter(); 2834 pcd->pcd_config_pmc(cpu, adjri, NULL); 2835 critical_exit(); 2836 2837 /* adjust the global and process count of SS mode PMCs */ 2838 if (mode == PMC_MODE_SS && pm->pm_state == PMC_STATE_RUNNING) { 2839 po = pm->pm_owner; 2840 po->po_sscount--; 2841 if (po->po_sscount == 0) { 2842 atomic_subtract_rel_int(&pmc_ss_count, 1); 2843 CK_LIST_REMOVE(po, po_ssnext); 2844 epoch_wait_preempt(global_epoch_preempt); 2845 } 2846 } 2847 2848 pm->pm_state = PMC_STATE_DELETED; 2849 2850 pmc_restore_cpu_binding(&pb); 2851 2852 /* 2853 * We could have references to this PMC structure in 2854 * the per-cpu sample queues. Wait for the queue to 2855 * drain. 2856 */ 2857 pmc_wait_for_pmc_idle(pm); 2858 2859 } else if (PMC_IS_VIRTUAL_MODE(mode)) { 2860 2861 /* 2862 * A virtual PMC could be running on multiple CPUs at 2863 * a given instant. 2864 * 2865 * By marking its state as DELETED, we ensure that 2866 * this PMC is never further scheduled on hardware. 2867 * 2868 * Then we wait till all CPUs are done with this PMC. 2869 */ 2870 pm->pm_state = PMC_STATE_DELETED; 2871 2872 2873 /* Wait for the PMCs runcount to come to zero. */ 2874 pmc_wait_for_pmc_idle(pm); 2875 2876 /* 2877 * At this point the PMC is off all CPUs and cannot be 2878 * freshly scheduled onto a CPU. It is now safe to 2879 * unlink all targets from this PMC. If a 2880 * process-record's refcount falls to zero, we remove 2881 * it from the hash table. The module-wide SX lock 2882 * protects us from races. 2883 */ 2884 LIST_FOREACH_SAFE(ptgt, &pm->pm_targets, pt_next, tmp) { 2885 pp = ptgt->pt_process; 2886 pmc_unlink_target_process(pm, pp); /* frees 'ptgt' */ 2887 2888 PMCDBG1(PMC,REL,3, "pp->refcnt=%d", pp->pp_refcnt); 2889 2890 /* 2891 * If the target process record shows that no 2892 * PMCs are attached to it, reclaim its space. 2893 */ 2894 2895 if (pp->pp_refcnt == 0) { 2896 pmc_remove_process_descriptor(pp); 2897 pmc_destroy_process_descriptor(pp); 2898 } 2899 } 2900 2901 cpu = curthread->td_oncpu; /* setup cpu for pmd_release() */ 2902 2903 } 2904 2905 /* 2906 * Release any MD resources 2907 */ 2908 (void) pcd->pcd_release_pmc(cpu, adjri, pm); 2909 2910 /* 2911 * Update row disposition 2912 */ 2913 2914 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) 2915 PMC_UNMARK_ROW_STANDALONE(ri); 2916 else 2917 PMC_UNMARK_ROW_THREAD(ri); 2918 2919 /* unlink from the owner's list */ 2920 if (pm->pm_owner) { 2921 LIST_REMOVE(pm, pm_next); 2922 pm->pm_owner = NULL; 2923 } 2924 } 2925 2926 /* 2927 * Register an owner and a pmc. 2928 */ 2929 2930 static int 2931 pmc_register_owner(struct proc *p, struct pmc *pmc) 2932 { 2933 struct pmc_owner *po; 2934 2935 sx_assert(&pmc_sx, SX_XLOCKED); 2936 2937 if ((po = pmc_find_owner_descriptor(p)) == NULL) 2938 if ((po = pmc_allocate_owner_descriptor(p)) == NULL) 2939 return ENOMEM; 2940 2941 KASSERT(pmc->pm_owner == NULL, 2942 ("[pmc,%d] attempting to own an initialized PMC", __LINE__)); 2943 pmc->pm_owner = po; 2944 2945 LIST_INSERT_HEAD(&po->po_pmcs, pmc, pm_next); 2946 2947 PROC_LOCK(p); 2948 p->p_flag |= P_HWPMC; 2949 PROC_UNLOCK(p); 2950 2951 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 2952 pmclog_process_pmcallocate(pmc); 2953 2954 PMCDBG2(PMC,REG,1, "register-owner pmc-owner=%p pmc=%p", 2955 po, pmc); 2956 2957 return 0; 2958 } 2959 2960 /* 2961 * Return the current row disposition: 2962 * == 0 => FREE 2963 * > 0 => PROCESS MODE 2964 * < 0 => SYSTEM MODE 2965 */ 2966 2967 int 2968 pmc_getrowdisp(int ri) 2969 { 2970 return pmc_pmcdisp[ri]; 2971 } 2972 2973 /* 2974 * Check if a PMC at row index 'ri' can be allocated to the current 2975 * process. 2976 * 2977 * Allocation can fail if: 2978 * - the current process is already being profiled by a PMC at index 'ri', 2979 * attached to it via OP_PMCATTACH. 2980 * - the current process has already allocated a PMC at index 'ri' 2981 * via OP_ALLOCATE. 2982 */ 2983 2984 static int 2985 pmc_can_allocate_rowindex(struct proc *p, unsigned int ri, int cpu) 2986 { 2987 enum pmc_mode mode; 2988 struct pmc *pm; 2989 struct pmc_owner *po; 2990 struct pmc_process *pp; 2991 2992 PMCDBG5(PMC,ALR,1, "can-allocate-rowindex proc=%p (%d, %s) ri=%d " 2993 "cpu=%d", p, p->p_pid, p->p_comm, ri, cpu); 2994 2995 /* 2996 * We shouldn't have already allocated a process-mode PMC at 2997 * row index 'ri'. 2998 * 2999 * We shouldn't have allocated a system-wide PMC on the same 3000 * CPU and same RI. 3001 */ 3002 if ((po = pmc_find_owner_descriptor(p)) != NULL) 3003 LIST_FOREACH(pm, &po->po_pmcs, pm_next) { 3004 if (PMC_TO_ROWINDEX(pm) == ri) { 3005 mode = PMC_TO_MODE(pm); 3006 if (PMC_IS_VIRTUAL_MODE(mode)) 3007 return EEXIST; 3008 if (PMC_IS_SYSTEM_MODE(mode) && 3009 (int) PMC_TO_CPU(pm) == cpu) 3010 return EEXIST; 3011 } 3012 } 3013 3014 /* 3015 * We also shouldn't be the target of any PMC at this index 3016 * since otherwise a PMC_ATTACH to ourselves will fail. 3017 */ 3018 if ((pp = pmc_find_process_descriptor(p, 0)) != NULL) 3019 if (pp->pp_pmcs[ri].pp_pmc) 3020 return EEXIST; 3021 3022 PMCDBG4(PMC,ALR,2, "can-allocate-rowindex proc=%p (%d, %s) ri=%d ok", 3023 p, p->p_pid, p->p_comm, ri); 3024 3025 return 0; 3026 } 3027 3028 /* 3029 * Check if a given PMC at row index 'ri' can be currently used in 3030 * mode 'mode'. 3031 */ 3032 3033 static int 3034 pmc_can_allocate_row(int ri, enum pmc_mode mode) 3035 { 3036 enum pmc_disp disp; 3037 3038 sx_assert(&pmc_sx, SX_XLOCKED); 3039 3040 PMCDBG2(PMC,ALR,1, "can-allocate-row ri=%d mode=%d", ri, mode); 3041 3042 if (PMC_IS_SYSTEM_MODE(mode)) 3043 disp = PMC_DISP_STANDALONE; 3044 else 3045 disp = PMC_DISP_THREAD; 3046 3047 /* 3048 * check disposition for PMC row 'ri': 3049 * 3050 * Expected disposition Row-disposition Result 3051 * 3052 * STANDALONE STANDALONE or FREE proceed 3053 * STANDALONE THREAD fail 3054 * THREAD THREAD or FREE proceed 3055 * THREAD STANDALONE fail 3056 */ 3057 3058 if (!PMC_ROW_DISP_IS_FREE(ri) && 3059 !(disp == PMC_DISP_THREAD && PMC_ROW_DISP_IS_THREAD(ri)) && 3060 !(disp == PMC_DISP_STANDALONE && PMC_ROW_DISP_IS_STANDALONE(ri))) 3061 return EBUSY; 3062 3063 /* 3064 * All OK 3065 */ 3066 3067 PMCDBG2(PMC,ALR,2, "can-allocate-row ri=%d mode=%d ok", ri, mode); 3068 3069 return 0; 3070 3071 } 3072 3073 /* 3074 * Find a PMC descriptor with user handle 'pmcid' for thread 'td'. 3075 */ 3076 3077 static struct pmc * 3078 pmc_find_pmc_descriptor_in_process(struct pmc_owner *po, pmc_id_t pmcid) 3079 { 3080 struct pmc *pm; 3081 3082 KASSERT(PMC_ID_TO_ROWINDEX(pmcid) < md->pmd_npmc, 3083 ("[pmc,%d] Illegal pmc index %d (max %d)", __LINE__, 3084 PMC_ID_TO_ROWINDEX(pmcid), md->pmd_npmc)); 3085 3086 LIST_FOREACH(pm, &po->po_pmcs, pm_next) 3087 if (pm->pm_id == pmcid) 3088 return pm; 3089 3090 return NULL; 3091 } 3092 3093 static int 3094 pmc_find_pmc(pmc_id_t pmcid, struct pmc **pmc) 3095 { 3096 3097 struct pmc *pm, *opm; 3098 struct pmc_owner *po; 3099 struct pmc_process *pp; 3100 3101 PMCDBG1(PMC,FND,1, "find-pmc id=%d", pmcid); 3102 if (PMC_ID_TO_ROWINDEX(pmcid) >= md->pmd_npmc) 3103 return (EINVAL); 3104 3105 if ((po = pmc_find_owner_descriptor(curthread->td_proc)) == NULL) { 3106 /* 3107 * In case of PMC_F_DESCENDANTS child processes we will not find 3108 * the current process in the owners hash list. Find the owner 3109 * process first and from there lookup the po. 3110 */ 3111 if ((pp = pmc_find_process_descriptor(curthread->td_proc, 3112 PMC_FLAG_NONE)) == NULL) { 3113 return ESRCH; 3114 } else { 3115 opm = pp->pp_pmcs[PMC_ID_TO_ROWINDEX(pmcid)].pp_pmc; 3116 if (opm == NULL) 3117 return ESRCH; 3118 if ((opm->pm_flags & (PMC_F_ATTACHED_TO_OWNER| 3119 PMC_F_DESCENDANTS)) != (PMC_F_ATTACHED_TO_OWNER| 3120 PMC_F_DESCENDANTS)) 3121 return ESRCH; 3122 po = opm->pm_owner; 3123 } 3124 } 3125 3126 if ((pm = pmc_find_pmc_descriptor_in_process(po, pmcid)) == NULL) 3127 return EINVAL; 3128 3129 PMCDBG2(PMC,FND,2, "find-pmc id=%d -> pmc=%p", pmcid, pm); 3130 3131 *pmc = pm; 3132 return 0; 3133 } 3134 3135 /* 3136 * Start a PMC. 3137 */ 3138 3139 static int 3140 pmc_start(struct pmc *pm) 3141 { 3142 enum pmc_mode mode; 3143 struct pmc_owner *po; 3144 struct pmc_binding pb; 3145 struct pmc_classdep *pcd; 3146 int adjri, error, cpu, ri; 3147 3148 KASSERT(pm != NULL, 3149 ("[pmc,%d] null pm", __LINE__)); 3150 3151 mode = PMC_TO_MODE(pm); 3152 ri = PMC_TO_ROWINDEX(pm); 3153 pcd = pmc_ri_to_classdep(md, ri, &adjri); 3154 3155 error = 0; 3156 3157 PMCDBG3(PMC,OPS,1, "start pmc=%p mode=%d ri=%d", pm, mode, ri); 3158 3159 po = pm->pm_owner; 3160 3161 /* 3162 * Disallow PMCSTART if a logfile is required but has not been 3163 * configured yet. 3164 */ 3165 if ((pm->pm_flags & PMC_F_NEEDS_LOGFILE) && 3166 (po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) 3167 return (EDOOFUS); /* programming error */ 3168 3169 /* 3170 * If this is a sampling mode PMC, log mapping information for 3171 * the kernel modules that are currently loaded. 3172 */ 3173 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 3174 pmc_log_kernel_mappings(pm); 3175 3176 if (PMC_IS_VIRTUAL_MODE(mode)) { 3177 3178 /* 3179 * If a PMCATTACH has never been done on this PMC, 3180 * attach it to its owner process. 3181 */ 3182 3183 if (LIST_EMPTY(&pm->pm_targets)) 3184 error = (pm->pm_flags & PMC_F_ATTACH_DONE) ? ESRCH : 3185 pmc_attach_process(po->po_owner, pm); 3186 3187 /* 3188 * If the PMC is attached to its owner, then force a context 3189 * switch to ensure that the MD state gets set correctly. 3190 */ 3191 3192 if (error == 0) { 3193 pm->pm_state = PMC_STATE_RUNNING; 3194 if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) 3195 pmc_force_context_switch(); 3196 } 3197 3198 return (error); 3199 } 3200 3201 3202 /* 3203 * A system-wide PMC. 3204 * 3205 * Add the owner to the global list if this is a system-wide 3206 * sampling PMC. 3207 */ 3208 3209 if (mode == PMC_MODE_SS) { 3210 /* 3211 * Log mapping information for all existing processes in the 3212 * system. Subsequent mappings are logged as they happen; 3213 * see pmc_process_mmap(). 3214 */ 3215 if (po->po_logprocmaps == 0) { 3216 pmc_log_all_process_mappings(po); 3217 po->po_logprocmaps = 1; 3218 } 3219 po->po_sscount++; 3220 if (po->po_sscount == 1) { 3221 atomic_add_rel_int(&pmc_ss_count, 1); 3222 CK_LIST_INSERT_HEAD(&pmc_ss_owners, po, po_ssnext); 3223 PMCDBG1(PMC,OPS,1, "po=%p in global list", po); 3224 } 3225 } 3226 3227 /* 3228 * Move to the CPU associated with this 3229 * PMC, and start the hardware. 3230 */ 3231 3232 pmc_save_cpu_binding(&pb); 3233 3234 cpu = PMC_TO_CPU(pm); 3235 3236 if (!pmc_cpu_is_active(cpu)) 3237 return (ENXIO); 3238 3239 pmc_select_cpu(cpu); 3240 3241 /* 3242 * global PMCs are configured at allocation time 3243 * so write out the initial value and start the PMC. 3244 */ 3245 3246 pm->pm_state = PMC_STATE_RUNNING; 3247 3248 critical_enter(); 3249 if ((error = pcd->pcd_write_pmc(cpu, adjri, 3250 PMC_IS_SAMPLING_MODE(mode) ? 3251 pm->pm_sc.pm_reloadcount : 3252 pm->pm_sc.pm_initial)) == 0) { 3253 /* If a sampling mode PMC, reset stalled state. */ 3254 if (PMC_IS_SAMPLING_MODE(mode)) 3255 pm->pm_pcpu_state[cpu].pps_stalled = 0; 3256 3257 /* Indicate that we desire this to run. Start it. */ 3258 pm->pm_pcpu_state[cpu].pps_cpustate = 1; 3259 error = pcd->pcd_start_pmc(cpu, adjri); 3260 } 3261 critical_exit(); 3262 3263 pmc_restore_cpu_binding(&pb); 3264 3265 return (error); 3266 } 3267 3268 /* 3269 * Stop a PMC. 3270 */ 3271 3272 static int 3273 pmc_stop(struct pmc *pm) 3274 { 3275 struct pmc_owner *po; 3276 struct pmc_binding pb; 3277 struct pmc_classdep *pcd; 3278 int adjri, cpu, error, ri; 3279 3280 KASSERT(pm != NULL, ("[pmc,%d] null pmc", __LINE__)); 3281 3282 PMCDBG3(PMC,OPS,1, "stop pmc=%p mode=%d ri=%d", pm, 3283 PMC_TO_MODE(pm), PMC_TO_ROWINDEX(pm)); 3284 3285 pm->pm_state = PMC_STATE_STOPPED; 3286 3287 /* 3288 * If the PMC is a virtual mode one, changing the state to 3289 * non-RUNNING is enough to ensure that the PMC never gets 3290 * scheduled. 3291 * 3292 * If this PMC is current running on a CPU, then it will 3293 * handled correctly at the time its target process is context 3294 * switched out. 3295 */ 3296 3297 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) 3298 return 0; 3299 3300 /* 3301 * A system-mode PMC. Move to the CPU associated with 3302 * this PMC, and stop the hardware. We update the 3303 * 'initial count' so that a subsequent PMCSTART will 3304 * resume counting from the current hardware count. 3305 */ 3306 3307 pmc_save_cpu_binding(&pb); 3308 3309 cpu = PMC_TO_CPU(pm); 3310 3311 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 3312 ("[pmc,%d] illegal cpu=%d", __LINE__, cpu)); 3313 3314 if (!pmc_cpu_is_active(cpu)) 3315 return ENXIO; 3316 3317 pmc_select_cpu(cpu); 3318 3319 ri = PMC_TO_ROWINDEX(pm); 3320 pcd = pmc_ri_to_classdep(md, ri, &adjri); 3321 3322 pm->pm_pcpu_state[cpu].pps_cpustate = 0; 3323 critical_enter(); 3324 if ((error = pcd->pcd_stop_pmc(cpu, adjri)) == 0) 3325 error = pcd->pcd_read_pmc(cpu, adjri, &pm->pm_sc.pm_initial); 3326 critical_exit(); 3327 3328 pmc_restore_cpu_binding(&pb); 3329 3330 po = pm->pm_owner; 3331 3332 /* remove this owner from the global list of SS PMC owners */ 3333 if (PMC_TO_MODE(pm) == PMC_MODE_SS) { 3334 po->po_sscount--; 3335 if (po->po_sscount == 0) { 3336 atomic_subtract_rel_int(&pmc_ss_count, 1); 3337 CK_LIST_REMOVE(po, po_ssnext); 3338 epoch_wait_preempt(global_epoch_preempt); 3339 PMCDBG1(PMC,OPS,2,"po=%p removed from global list", po); 3340 } 3341 } 3342 3343 return (error); 3344 } 3345 3346 static struct pmc_classdep * 3347 pmc_class_to_classdep(enum pmc_class class) 3348 { 3349 int n; 3350 3351 for (n = 0; n < md->pmd_nclass; n++) 3352 if (md->pmd_classdep[n].pcd_class == class) 3353 return (&md->pmd_classdep[n]); 3354 return (NULL); 3355 } 3356 3357 #if defined(HWPMC_DEBUG) && defined(KTR) 3358 static const char *pmc_op_to_name[] = { 3359 #undef __PMC_OP 3360 #define __PMC_OP(N, D) #N , 3361 __PMC_OPS() 3362 NULL 3363 }; 3364 #endif 3365 3366 /* 3367 * The syscall interface 3368 */ 3369 3370 #define PMC_GET_SX_XLOCK(...) do { \ 3371 sx_xlock(&pmc_sx); \ 3372 if (pmc_hook == NULL) { \ 3373 sx_xunlock(&pmc_sx); \ 3374 return __VA_ARGS__; \ 3375 } \ 3376 } while (0) 3377 3378 #define PMC_DOWNGRADE_SX() do { \ 3379 sx_downgrade(&pmc_sx); \ 3380 is_sx_downgraded = 1; \ 3381 } while (0) 3382 3383 static int 3384 pmc_syscall_handler(struct thread *td, void *syscall_args) 3385 { 3386 int error, is_sx_downgraded, op; 3387 struct pmc_syscall_args *c; 3388 void *pmclog_proc_handle; 3389 void *arg; 3390 3391 c = (struct pmc_syscall_args *)syscall_args; 3392 op = c->pmop_code; 3393 arg = c->pmop_data; 3394 /* PMC isn't set up yet */ 3395 if (pmc_hook == NULL) 3396 return (EINVAL); 3397 if (op == PMC_OP_CONFIGURELOG) { 3398 /* 3399 * We cannot create the logging process inside 3400 * pmclog_configure_log() because there is a LOR 3401 * between pmc_sx and process structure locks. 3402 * Instead, pre-create the process and ignite the loop 3403 * if everything is fine, otherwise direct the process 3404 * to exit. 3405 */ 3406 error = pmclog_proc_create(td, &pmclog_proc_handle); 3407 if (error != 0) 3408 goto done_syscall; 3409 } 3410 3411 PMC_GET_SX_XLOCK(ENOSYS); 3412 is_sx_downgraded = 0; 3413 PMCDBG3(MOD,PMS,1, "syscall op=%d \"%s\" arg=%p", op, 3414 pmc_op_to_name[op], arg); 3415 3416 error = 0; 3417 counter_u64_add(pmc_stats.pm_syscalls, 1); 3418 3419 switch (op) { 3420 3421 3422 /* 3423 * Configure a log file. 3424 * 3425 * XXX This OP will be reworked. 3426 */ 3427 3428 case PMC_OP_CONFIGURELOG: 3429 { 3430 struct proc *p; 3431 struct pmc *pm; 3432 struct pmc_owner *po; 3433 struct pmc_op_configurelog cl; 3434 3435 if ((error = copyin(arg, &cl, sizeof(cl))) != 0) { 3436 pmclog_proc_ignite(pmclog_proc_handle, NULL); 3437 break; 3438 } 3439 3440 /* mark this process as owning a log file */ 3441 p = td->td_proc; 3442 if ((po = pmc_find_owner_descriptor(p)) == NULL) 3443 if ((po = pmc_allocate_owner_descriptor(p)) == NULL) { 3444 pmclog_proc_ignite(pmclog_proc_handle, NULL); 3445 error = ENOMEM; 3446 break; 3447 } 3448 3449 /* 3450 * If a valid fd was passed in, try to configure that, 3451 * otherwise if 'fd' was less than zero and there was 3452 * a log file configured, flush its buffers and 3453 * de-configure it. 3454 */ 3455 if (cl.pm_logfd >= 0) { 3456 error = pmclog_configure_log(md, po, cl.pm_logfd); 3457 pmclog_proc_ignite(pmclog_proc_handle, error == 0 ? 3458 po : NULL); 3459 } else if (po->po_flags & PMC_PO_OWNS_LOGFILE) { 3460 pmclog_proc_ignite(pmclog_proc_handle, NULL); 3461 error = pmclog_close(po); 3462 if (error == 0) { 3463 LIST_FOREACH(pm, &po->po_pmcs, pm_next) 3464 if (pm->pm_flags & PMC_F_NEEDS_LOGFILE && 3465 pm->pm_state == PMC_STATE_RUNNING) 3466 pmc_stop(pm); 3467 error = pmclog_deconfigure_log(po); 3468 } 3469 } else { 3470 pmclog_proc_ignite(pmclog_proc_handle, NULL); 3471 error = EINVAL; 3472 } 3473 } 3474 break; 3475 3476 /* 3477 * Flush a log file. 3478 */ 3479 3480 case PMC_OP_FLUSHLOG: 3481 { 3482 struct pmc_owner *po; 3483 3484 sx_assert(&pmc_sx, SX_XLOCKED); 3485 3486 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 3487 error = EINVAL; 3488 break; 3489 } 3490 3491 error = pmclog_flush(po, 0); 3492 } 3493 break; 3494 3495 /* 3496 * Close a log file. 3497 */ 3498 3499 case PMC_OP_CLOSELOG: 3500 { 3501 struct pmc_owner *po; 3502 3503 sx_assert(&pmc_sx, SX_XLOCKED); 3504 3505 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 3506 error = EINVAL; 3507 break; 3508 } 3509 3510 error = pmclog_close(po); 3511 } 3512 break; 3513 3514 /* 3515 * Retrieve hardware configuration. 3516 */ 3517 3518 case PMC_OP_GETCPUINFO: /* CPU information */ 3519 { 3520 struct pmc_op_getcpuinfo gci; 3521 struct pmc_classinfo *pci; 3522 struct pmc_classdep *pcd; 3523 int cl; 3524 3525 memset(&gci, 0, sizeof(gci)); 3526 gci.pm_cputype = md->pmd_cputype; 3527 gci.pm_ncpu = pmc_cpu_max(); 3528 gci.pm_npmc = md->pmd_npmc; 3529 gci.pm_nclass = md->pmd_nclass; 3530 pci = gci.pm_classes; 3531 pcd = md->pmd_classdep; 3532 for (cl = 0; cl < md->pmd_nclass; cl++, pci++, pcd++) { 3533 pci->pm_caps = pcd->pcd_caps; 3534 pci->pm_class = pcd->pcd_class; 3535 pci->pm_width = pcd->pcd_width; 3536 pci->pm_num = pcd->pcd_num; 3537 } 3538 error = copyout(&gci, arg, sizeof(gci)); 3539 } 3540 break; 3541 3542 /* 3543 * Retrieve soft events list. 3544 */ 3545 case PMC_OP_GETDYNEVENTINFO: 3546 { 3547 enum pmc_class cl; 3548 enum pmc_event ev; 3549 struct pmc_op_getdyneventinfo *gei; 3550 struct pmc_dyn_event_descr dev; 3551 struct pmc_soft *ps; 3552 uint32_t nevent; 3553 3554 sx_assert(&pmc_sx, SX_LOCKED); 3555 3556 gei = (struct pmc_op_getdyneventinfo *) arg; 3557 3558 if ((error = copyin(&gei->pm_class, &cl, sizeof(cl))) != 0) 3559 break; 3560 3561 /* Only SOFT class is dynamic. */ 3562 if (cl != PMC_CLASS_SOFT) { 3563 error = EINVAL; 3564 break; 3565 } 3566 3567 nevent = 0; 3568 for (ev = PMC_EV_SOFT_FIRST; (int)ev <= PMC_EV_SOFT_LAST; ev++) { 3569 ps = pmc_soft_ev_acquire(ev); 3570 if (ps == NULL) 3571 continue; 3572 bcopy(&ps->ps_ev, &dev, sizeof(dev)); 3573 pmc_soft_ev_release(ps); 3574 3575 error = copyout(&dev, 3576 &gei->pm_events[nevent], 3577 sizeof(struct pmc_dyn_event_descr)); 3578 if (error != 0) 3579 break; 3580 nevent++; 3581 } 3582 if (error != 0) 3583 break; 3584 3585 error = copyout(&nevent, &gei->pm_nevent, 3586 sizeof(nevent)); 3587 } 3588 break; 3589 3590 /* 3591 * Get module statistics 3592 */ 3593 3594 case PMC_OP_GETDRIVERSTATS: 3595 { 3596 struct pmc_op_getdriverstats gms; 3597 #define CFETCH(a, b, field) a.field = counter_u64_fetch(b.field) 3598 CFETCH(gms, pmc_stats, pm_intr_ignored); 3599 CFETCH(gms, pmc_stats, pm_intr_processed); 3600 CFETCH(gms, pmc_stats, pm_intr_bufferfull); 3601 CFETCH(gms, pmc_stats, pm_syscalls); 3602 CFETCH(gms, pmc_stats, pm_syscall_errors); 3603 CFETCH(gms, pmc_stats, pm_buffer_requests); 3604 CFETCH(gms, pmc_stats, pm_buffer_requests_failed); 3605 CFETCH(gms, pmc_stats, pm_log_sweeps); 3606 #undef CFETCH 3607 error = copyout(&gms, arg, sizeof(gms)); 3608 } 3609 break; 3610 3611 3612 /* 3613 * Retrieve module version number 3614 */ 3615 3616 case PMC_OP_GETMODULEVERSION: 3617 { 3618 uint32_t cv, modv; 3619 3620 /* retrieve the client's idea of the ABI version */ 3621 if ((error = copyin(arg, &cv, sizeof(uint32_t))) != 0) 3622 break; 3623 /* don't service clients newer than our driver */ 3624 modv = PMC_VERSION; 3625 if ((cv & 0xFFFF0000) > (modv & 0xFFFF0000)) { 3626 error = EPROGMISMATCH; 3627 break; 3628 } 3629 error = copyout(&modv, arg, sizeof(int)); 3630 } 3631 break; 3632 3633 3634 /* 3635 * Retrieve the state of all the PMCs on a given 3636 * CPU. 3637 */ 3638 3639 case PMC_OP_GETPMCINFO: 3640 { 3641 int ari; 3642 struct pmc *pm; 3643 size_t pmcinfo_size; 3644 uint32_t cpu, n, npmc; 3645 struct pmc_owner *po; 3646 struct pmc_binding pb; 3647 struct pmc_classdep *pcd; 3648 struct pmc_info *p, *pmcinfo; 3649 struct pmc_op_getpmcinfo *gpi; 3650 3651 PMC_DOWNGRADE_SX(); 3652 3653 gpi = (struct pmc_op_getpmcinfo *) arg; 3654 3655 if ((error = copyin(&gpi->pm_cpu, &cpu, sizeof(cpu))) != 0) 3656 break; 3657 3658 if (cpu >= pmc_cpu_max()) { 3659 error = EINVAL; 3660 break; 3661 } 3662 3663 if (!pmc_cpu_is_active(cpu)) { 3664 error = ENXIO; 3665 break; 3666 } 3667 3668 /* switch to CPU 'cpu' */ 3669 pmc_save_cpu_binding(&pb); 3670 pmc_select_cpu(cpu); 3671 3672 npmc = md->pmd_npmc; 3673 3674 pmcinfo_size = npmc * sizeof(struct pmc_info); 3675 pmcinfo = malloc(pmcinfo_size, M_PMC, M_WAITOK | M_ZERO); 3676 3677 p = pmcinfo; 3678 3679 for (n = 0; n < md->pmd_npmc; n++, p++) { 3680 3681 pcd = pmc_ri_to_classdep(md, n, &ari); 3682 3683 KASSERT(pcd != NULL, 3684 ("[pmc,%d] null pcd ri=%d", __LINE__, n)); 3685 3686 if ((error = pcd->pcd_describe(cpu, ari, p, &pm)) != 0) 3687 break; 3688 3689 if (PMC_ROW_DISP_IS_STANDALONE(n)) 3690 p->pm_rowdisp = PMC_DISP_STANDALONE; 3691 else if (PMC_ROW_DISP_IS_THREAD(n)) 3692 p->pm_rowdisp = PMC_DISP_THREAD; 3693 else 3694 p->pm_rowdisp = PMC_DISP_FREE; 3695 3696 p->pm_ownerpid = -1; 3697 3698 if (pm == NULL) /* no PMC associated */ 3699 continue; 3700 3701 po = pm->pm_owner; 3702 3703 KASSERT(po->po_owner != NULL, 3704 ("[pmc,%d] pmc_owner had a null proc pointer", 3705 __LINE__)); 3706 3707 p->pm_ownerpid = po->po_owner->p_pid; 3708 p->pm_mode = PMC_TO_MODE(pm); 3709 p->pm_event = pm->pm_event; 3710 p->pm_flags = pm->pm_flags; 3711 3712 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 3713 p->pm_reloadcount = 3714 pm->pm_sc.pm_reloadcount; 3715 } 3716 3717 pmc_restore_cpu_binding(&pb); 3718 3719 /* now copy out the PMC info collected */ 3720 if (error == 0) 3721 error = copyout(pmcinfo, &gpi->pm_pmcs, pmcinfo_size); 3722 3723 free(pmcinfo, M_PMC); 3724 } 3725 break; 3726 3727 3728 /* 3729 * Set the administrative state of a PMC. I.e. whether 3730 * the PMC is to be used or not. 3731 */ 3732 3733 case PMC_OP_PMCADMIN: 3734 { 3735 int cpu, ri; 3736 enum pmc_state request; 3737 struct pmc_cpu *pc; 3738 struct pmc_hw *phw; 3739 struct pmc_op_pmcadmin pma; 3740 struct pmc_binding pb; 3741 3742 sx_assert(&pmc_sx, SX_XLOCKED); 3743 3744 KASSERT(td == curthread, 3745 ("[pmc,%d] td != curthread", __LINE__)); 3746 3747 error = priv_check(td, PRIV_PMC_MANAGE); 3748 if (error) 3749 break; 3750 3751 if ((error = copyin(arg, &pma, sizeof(pma))) != 0) 3752 break; 3753 3754 cpu = pma.pm_cpu; 3755 3756 if (cpu < 0 || cpu >= (int) pmc_cpu_max()) { 3757 error = EINVAL; 3758 break; 3759 } 3760 3761 if (!pmc_cpu_is_active(cpu)) { 3762 error = ENXIO; 3763 break; 3764 } 3765 3766 request = pma.pm_state; 3767 3768 if (request != PMC_STATE_DISABLED && 3769 request != PMC_STATE_FREE) { 3770 error = EINVAL; 3771 break; 3772 } 3773 3774 ri = pma.pm_pmc; /* pmc id == row index */ 3775 if (ri < 0 || ri >= (int) md->pmd_npmc) { 3776 error = EINVAL; 3777 break; 3778 } 3779 3780 /* 3781 * We can't disable a PMC with a row-index allocated 3782 * for process virtual PMCs. 3783 */ 3784 3785 if (PMC_ROW_DISP_IS_THREAD(ri) && 3786 request == PMC_STATE_DISABLED) { 3787 error = EBUSY; 3788 break; 3789 } 3790 3791 /* 3792 * otherwise, this PMC on this CPU is either free or 3793 * in system-wide mode. 3794 */ 3795 3796 pmc_save_cpu_binding(&pb); 3797 pmc_select_cpu(cpu); 3798 3799 pc = pmc_pcpu[cpu]; 3800 phw = pc->pc_hwpmcs[ri]; 3801 3802 /* 3803 * XXX do we need some kind of 'forced' disable? 3804 */ 3805 3806 if (phw->phw_pmc == NULL) { 3807 if (request == PMC_STATE_DISABLED && 3808 (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED)) { 3809 phw->phw_state &= ~PMC_PHW_FLAG_IS_ENABLED; 3810 PMC_MARK_ROW_STANDALONE(ri); 3811 } else if (request == PMC_STATE_FREE && 3812 (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0) { 3813 phw->phw_state |= PMC_PHW_FLAG_IS_ENABLED; 3814 PMC_UNMARK_ROW_STANDALONE(ri); 3815 } 3816 /* other cases are a no-op */ 3817 } else 3818 error = EBUSY; 3819 3820 pmc_restore_cpu_binding(&pb); 3821 } 3822 break; 3823 3824 3825 /* 3826 * Allocate a PMC. 3827 */ 3828 3829 case PMC_OP_PMCALLOCATE: 3830 { 3831 int adjri, n; 3832 u_int cpu; 3833 uint32_t caps; 3834 struct pmc *pmc; 3835 enum pmc_mode mode; 3836 struct pmc_hw *phw; 3837 struct pmc_binding pb; 3838 struct pmc_classdep *pcd; 3839 struct pmc_op_pmcallocate pa; 3840 3841 if ((error = copyin(arg, &pa, sizeof(pa))) != 0) 3842 break; 3843 3844 caps = pa.pm_caps; 3845 mode = pa.pm_mode; 3846 cpu = pa.pm_cpu; 3847 3848 if ((mode != PMC_MODE_SS && mode != PMC_MODE_SC && 3849 mode != PMC_MODE_TS && mode != PMC_MODE_TC) || 3850 (cpu != (u_int) PMC_CPU_ANY && cpu >= pmc_cpu_max())) { 3851 error = EINVAL; 3852 break; 3853 } 3854 3855 /* 3856 * Virtual PMCs should only ask for a default CPU. 3857 * System mode PMCs need to specify a non-default CPU. 3858 */ 3859 3860 if ((PMC_IS_VIRTUAL_MODE(mode) && cpu != (u_int) PMC_CPU_ANY) || 3861 (PMC_IS_SYSTEM_MODE(mode) && cpu == (u_int) PMC_CPU_ANY)) { 3862 error = EINVAL; 3863 break; 3864 } 3865 3866 /* 3867 * Check that an inactive CPU is not being asked for. 3868 */ 3869 3870 if (PMC_IS_SYSTEM_MODE(mode) && !pmc_cpu_is_active(cpu)) { 3871 error = ENXIO; 3872 break; 3873 } 3874 3875 /* 3876 * Refuse an allocation for a system-wide PMC if this 3877 * process has been jailed, or if this process lacks 3878 * super-user credentials and the sysctl tunable 3879 * 'security.bsd.unprivileged_syspmcs' is zero. 3880 */ 3881 3882 if (PMC_IS_SYSTEM_MODE(mode)) { 3883 if (jailed(curthread->td_ucred)) { 3884 error = EPERM; 3885 break; 3886 } 3887 if (!pmc_unprivileged_syspmcs) { 3888 error = priv_check(curthread, 3889 PRIV_PMC_SYSTEM); 3890 if (error) 3891 break; 3892 } 3893 } 3894 3895 /* 3896 * Look for valid values for 'pm_flags' 3897 */ 3898 3899 if ((pa.pm_flags & ~(PMC_F_DESCENDANTS | PMC_F_LOG_PROCCSW | 3900 PMC_F_LOG_PROCEXIT | PMC_F_CALLCHAIN | 3901 PMC_F_USERCALLCHAIN)) != 0) { 3902 error = EINVAL; 3903 break; 3904 } 3905 3906 /* PMC_F_USERCALLCHAIN is only valid with PMC_F_CALLCHAIN */ 3907 if ((pa.pm_flags & (PMC_F_CALLCHAIN | PMC_F_USERCALLCHAIN)) == 3908 PMC_F_USERCALLCHAIN) { 3909 error = EINVAL; 3910 break; 3911 } 3912 3913 /* PMC_F_USERCALLCHAIN is only valid for sampling mode */ 3914 if (pa.pm_flags & PMC_F_USERCALLCHAIN && 3915 mode != PMC_MODE_TS && mode != PMC_MODE_SS) { 3916 error = EINVAL; 3917 break; 3918 } 3919 3920 /* process logging options are not allowed for system PMCs */ 3921 if (PMC_IS_SYSTEM_MODE(mode) && (pa.pm_flags & 3922 (PMC_F_LOG_PROCCSW | PMC_F_LOG_PROCEXIT))) { 3923 error = EINVAL; 3924 break; 3925 } 3926 3927 /* 3928 * All sampling mode PMCs need to be able to interrupt the 3929 * CPU. 3930 */ 3931 if (PMC_IS_SAMPLING_MODE(mode)) 3932 caps |= PMC_CAP_INTERRUPT; 3933 3934 /* A valid class specifier should have been passed in. */ 3935 pcd = pmc_class_to_classdep(pa.pm_class); 3936 if (pcd == NULL) { 3937 error = EINVAL; 3938 break; 3939 } 3940 3941 /* The requested PMC capabilities should be feasible. */ 3942 if ((pcd->pcd_caps & caps) != caps) { 3943 error = EOPNOTSUPP; 3944 break; 3945 } 3946 3947 PMCDBG4(PMC,ALL,2, "event=%d caps=0x%x mode=%d cpu=%d", 3948 pa.pm_ev, caps, mode, cpu); 3949 3950 pmc = pmc_allocate_pmc_descriptor(); 3951 pmc->pm_id = PMC_ID_MAKE_ID(cpu,pa.pm_mode,pa.pm_class, 3952 PMC_ID_INVALID); 3953 pmc->pm_event = pa.pm_ev; 3954 pmc->pm_state = PMC_STATE_FREE; 3955 pmc->pm_caps = caps; 3956 pmc->pm_flags = pa.pm_flags; 3957 3958 /* XXX set lower bound on sampling for process counters */ 3959 if (PMC_IS_SAMPLING_MODE(mode)) { 3960 /* 3961 * Don't permit requested sample rate to be 3962 * less than pmc_mincount. 3963 */ 3964 if (pa.pm_count < MAX(1, pmc_mincount)) 3965 log(LOG_WARNING, "pmcallocate: passed sample " 3966 "rate %ju - setting to %u\n", 3967 (uintmax_t)pa.pm_count, 3968 MAX(1, pmc_mincount)); 3969 pmc->pm_sc.pm_reloadcount = MAX(MAX(1, pmc_mincount), 3970 pa.pm_count); 3971 } else 3972 pmc->pm_sc.pm_initial = pa.pm_count; 3973 3974 /* switch thread to CPU 'cpu' */ 3975 pmc_save_cpu_binding(&pb); 3976 3977 #define PMC_IS_SHAREABLE_PMC(cpu, n) \ 3978 (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_state & \ 3979 PMC_PHW_FLAG_IS_SHAREABLE) 3980 #define PMC_IS_UNALLOCATED(cpu, n) \ 3981 (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_pmc == NULL) 3982 3983 if (PMC_IS_SYSTEM_MODE(mode)) { 3984 pmc_select_cpu(cpu); 3985 for (n = pcd->pcd_ri; n < (int) md->pmd_npmc; n++) { 3986 pcd = pmc_ri_to_classdep(md, n, &adjri); 3987 if (pmc_can_allocate_row(n, mode) == 0 && 3988 pmc_can_allocate_rowindex( 3989 curthread->td_proc, n, cpu) == 0 && 3990 (PMC_IS_UNALLOCATED(cpu, n) || 3991 PMC_IS_SHAREABLE_PMC(cpu, n)) && 3992 pcd->pcd_allocate_pmc(cpu, adjri, pmc, 3993 &pa) == 0) 3994 break; 3995 } 3996 } else { 3997 /* Process virtual mode */ 3998 for (n = pcd->pcd_ri; n < (int) md->pmd_npmc; n++) { 3999 pcd = pmc_ri_to_classdep(md, n, &adjri); 4000 if (pmc_can_allocate_row(n, mode) == 0 && 4001 pmc_can_allocate_rowindex( 4002 curthread->td_proc, n, 4003 PMC_CPU_ANY) == 0 && 4004 pcd->pcd_allocate_pmc(curthread->td_oncpu, 4005 adjri, pmc, &pa) == 0) 4006 break; 4007 } 4008 } 4009 4010 #undef PMC_IS_UNALLOCATED 4011 #undef PMC_IS_SHAREABLE_PMC 4012 4013 pmc_restore_cpu_binding(&pb); 4014 4015 if (n == (int) md->pmd_npmc) { 4016 pmc_destroy_pmc_descriptor(pmc); 4017 pmc = NULL; 4018 error = EINVAL; 4019 break; 4020 } 4021 4022 /* Fill in the correct value in the ID field */ 4023 pmc->pm_id = PMC_ID_MAKE_ID(cpu,mode,pa.pm_class,n); 4024 4025 PMCDBG5(PMC,ALL,2, "ev=%d class=%d mode=%d n=%d -> pmcid=%x", 4026 pmc->pm_event, pa.pm_class, mode, n, pmc->pm_id); 4027 4028 /* Process mode PMCs with logging enabled need log files */ 4029 if (pmc->pm_flags & (PMC_F_LOG_PROCEXIT | PMC_F_LOG_PROCCSW)) 4030 pmc->pm_flags |= PMC_F_NEEDS_LOGFILE; 4031 4032 /* All system mode sampling PMCs require a log file */ 4033 if (PMC_IS_SAMPLING_MODE(mode) && PMC_IS_SYSTEM_MODE(mode)) 4034 pmc->pm_flags |= PMC_F_NEEDS_LOGFILE; 4035 4036 /* 4037 * Configure global pmc's immediately 4038 */ 4039 4040 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pmc))) { 4041 4042 pmc_save_cpu_binding(&pb); 4043 pmc_select_cpu(cpu); 4044 4045 phw = pmc_pcpu[cpu]->pc_hwpmcs[n]; 4046 pcd = pmc_ri_to_classdep(md, n, &adjri); 4047 4048 if ((phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0 || 4049 (error = pcd->pcd_config_pmc(cpu, adjri, pmc)) != 0) { 4050 (void) pcd->pcd_release_pmc(cpu, adjri, pmc); 4051 pmc_destroy_pmc_descriptor(pmc); 4052 pmc = NULL; 4053 pmc_restore_cpu_binding(&pb); 4054 error = EPERM; 4055 break; 4056 } 4057 4058 pmc_restore_cpu_binding(&pb); 4059 } 4060 4061 pmc->pm_state = PMC_STATE_ALLOCATED; 4062 pmc->pm_class = pa.pm_class; 4063 4064 /* 4065 * mark row disposition 4066 */ 4067 4068 if (PMC_IS_SYSTEM_MODE(mode)) 4069 PMC_MARK_ROW_STANDALONE(n); 4070 else 4071 PMC_MARK_ROW_THREAD(n); 4072 4073 /* 4074 * Register this PMC with the current thread as its owner. 4075 */ 4076 4077 if ((error = 4078 pmc_register_owner(curthread->td_proc, pmc)) != 0) { 4079 pmc_release_pmc_descriptor(pmc); 4080 pmc_destroy_pmc_descriptor(pmc); 4081 pmc = NULL; 4082 break; 4083 } 4084 4085 4086 /* 4087 * Return the allocated index. 4088 */ 4089 4090 pa.pm_pmcid = pmc->pm_id; 4091 4092 error = copyout(&pa, arg, sizeof(pa)); 4093 } 4094 break; 4095 4096 4097 /* 4098 * Attach a PMC to a process. 4099 */ 4100 4101 case PMC_OP_PMCATTACH: 4102 { 4103 struct pmc *pm; 4104 struct proc *p; 4105 struct pmc_op_pmcattach a; 4106 4107 sx_assert(&pmc_sx, SX_XLOCKED); 4108 4109 if ((error = copyin(arg, &a, sizeof(a))) != 0) 4110 break; 4111 4112 if (a.pm_pid < 0) { 4113 error = EINVAL; 4114 break; 4115 } else if (a.pm_pid == 0) 4116 a.pm_pid = td->td_proc->p_pid; 4117 4118 if ((error = pmc_find_pmc(a.pm_pmc, &pm)) != 0) 4119 break; 4120 4121 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) { 4122 error = EINVAL; 4123 break; 4124 } 4125 4126 /* PMCs may be (re)attached only when allocated or stopped */ 4127 if (pm->pm_state == PMC_STATE_RUNNING) { 4128 error = EBUSY; 4129 break; 4130 } else if (pm->pm_state != PMC_STATE_ALLOCATED && 4131 pm->pm_state != PMC_STATE_STOPPED) { 4132 error = EINVAL; 4133 break; 4134 } 4135 4136 /* lookup pid */ 4137 if ((p = pfind(a.pm_pid)) == NULL) { 4138 error = ESRCH; 4139 break; 4140 } 4141 4142 /* 4143 * Ignore processes that are working on exiting. 4144 */ 4145 if (p->p_flag & P_WEXIT) { 4146 error = ESRCH; 4147 PROC_UNLOCK(p); /* pfind() returns a locked process */ 4148 break; 4149 } 4150 4151 /* 4152 * we are allowed to attach a PMC to a process if 4153 * we can debug it. 4154 */ 4155 error = p_candebug(curthread, p); 4156 4157 PROC_UNLOCK(p); 4158 4159 if (error == 0) 4160 error = pmc_attach_process(p, pm); 4161 } 4162 break; 4163 4164 4165 /* 4166 * Detach an attached PMC from a process. 4167 */ 4168 4169 case PMC_OP_PMCDETACH: 4170 { 4171 struct pmc *pm; 4172 struct proc *p; 4173 struct pmc_op_pmcattach a; 4174 4175 if ((error = copyin(arg, &a, sizeof(a))) != 0) 4176 break; 4177 4178 if (a.pm_pid < 0) { 4179 error = EINVAL; 4180 break; 4181 } else if (a.pm_pid == 0) 4182 a.pm_pid = td->td_proc->p_pid; 4183 4184 if ((error = pmc_find_pmc(a.pm_pmc, &pm)) != 0) 4185 break; 4186 4187 if ((p = pfind(a.pm_pid)) == NULL) { 4188 error = ESRCH; 4189 break; 4190 } 4191 4192 /* 4193 * Treat processes that are in the process of exiting 4194 * as if they were not present. 4195 */ 4196 4197 if (p->p_flag & P_WEXIT) 4198 error = ESRCH; 4199 4200 PROC_UNLOCK(p); /* pfind() returns a locked process */ 4201 4202 if (error == 0) 4203 error = pmc_detach_process(p, pm); 4204 } 4205 break; 4206 4207 4208 /* 4209 * Retrieve the MSR number associated with the counter 4210 * 'pmc_id'. This allows processes to directly use RDPMC 4211 * instructions to read their PMCs, without the overhead of a 4212 * system call. 4213 */ 4214 4215 case PMC_OP_PMCGETMSR: 4216 { 4217 int adjri, ri; 4218 struct pmc *pm; 4219 struct pmc_target *pt; 4220 struct pmc_op_getmsr gm; 4221 struct pmc_classdep *pcd; 4222 4223 PMC_DOWNGRADE_SX(); 4224 4225 if ((error = copyin(arg, &gm, sizeof(gm))) != 0) 4226 break; 4227 4228 if ((error = pmc_find_pmc(gm.pm_pmcid, &pm)) != 0) 4229 break; 4230 4231 /* 4232 * The allocated PMC has to be a process virtual PMC, 4233 * i.e., of type MODE_T[CS]. Global PMCs can only be 4234 * read using the PMCREAD operation since they may be 4235 * allocated on a different CPU than the one we could 4236 * be running on at the time of the RDPMC instruction. 4237 * 4238 * The GETMSR operation is not allowed for PMCs that 4239 * are inherited across processes. 4240 */ 4241 4242 if (!PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)) || 4243 (pm->pm_flags & PMC_F_DESCENDANTS)) { 4244 error = EINVAL; 4245 break; 4246 } 4247 4248 /* 4249 * It only makes sense to use a RDPMC (or its 4250 * equivalent instruction on non-x86 architectures) on 4251 * a process that has allocated and attached a PMC to 4252 * itself. Conversely the PMC is only allowed to have 4253 * one process attached to it -- its owner. 4254 */ 4255 4256 if ((pt = LIST_FIRST(&pm->pm_targets)) == NULL || 4257 LIST_NEXT(pt, pt_next) != NULL || 4258 pt->pt_process->pp_proc != pm->pm_owner->po_owner) { 4259 error = EINVAL; 4260 break; 4261 } 4262 4263 ri = PMC_TO_ROWINDEX(pm); 4264 pcd = pmc_ri_to_classdep(md, ri, &adjri); 4265 4266 /* PMC class has no 'GETMSR' support */ 4267 if (pcd->pcd_get_msr == NULL) { 4268 error = ENOSYS; 4269 break; 4270 } 4271 4272 if ((error = (*pcd->pcd_get_msr)(adjri, &gm.pm_msr)) < 0) 4273 break; 4274 4275 if ((error = copyout(&gm, arg, sizeof(gm))) < 0) 4276 break; 4277 4278 /* 4279 * Mark our process as using MSRs. Update machine 4280 * state using a forced context switch. 4281 */ 4282 4283 pt->pt_process->pp_flags |= PMC_PP_ENABLE_MSR_ACCESS; 4284 pmc_force_context_switch(); 4285 4286 } 4287 break; 4288 4289 /* 4290 * Release an allocated PMC 4291 */ 4292 4293 case PMC_OP_PMCRELEASE: 4294 { 4295 pmc_id_t pmcid; 4296 struct pmc *pm; 4297 struct pmc_owner *po; 4298 struct pmc_op_simple sp; 4299 4300 /* 4301 * Find PMC pointer for the named PMC. 4302 * 4303 * Use pmc_release_pmc_descriptor() to switch off the 4304 * PMC, remove all its target threads, and remove the 4305 * PMC from its owner's list. 4306 * 4307 * Remove the owner record if this is the last PMC 4308 * owned. 4309 * 4310 * Free up space. 4311 */ 4312 4313 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 4314 break; 4315 4316 pmcid = sp.pm_pmcid; 4317 4318 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 4319 break; 4320 4321 po = pm->pm_owner; 4322 pmc_release_pmc_descriptor(pm); 4323 pmc_maybe_remove_owner(po); 4324 pmc_destroy_pmc_descriptor(pm); 4325 } 4326 break; 4327 4328 4329 /* 4330 * Read and/or write a PMC. 4331 */ 4332 4333 case PMC_OP_PMCRW: 4334 { 4335 int adjri; 4336 struct pmc *pm; 4337 uint32_t cpu, ri; 4338 pmc_value_t oldvalue; 4339 struct pmc_binding pb; 4340 struct pmc_op_pmcrw prw; 4341 struct pmc_classdep *pcd; 4342 struct pmc_op_pmcrw *pprw; 4343 4344 PMC_DOWNGRADE_SX(); 4345 4346 if ((error = copyin(arg, &prw, sizeof(prw))) != 0) 4347 break; 4348 4349 PMCDBG2(PMC,OPS,1, "rw id=%d flags=0x%x", prw.pm_pmcid, 4350 prw.pm_flags); 4351 4352 /* must have at least one flag set */ 4353 if ((prw.pm_flags & (PMC_F_OLDVALUE|PMC_F_NEWVALUE)) == 0) { 4354 error = EINVAL; 4355 break; 4356 } 4357 4358 /* locate pmc descriptor */ 4359 if ((error = pmc_find_pmc(prw.pm_pmcid, &pm)) != 0) 4360 break; 4361 4362 /* Can't read a PMC that hasn't been started. */ 4363 if (pm->pm_state != PMC_STATE_ALLOCATED && 4364 pm->pm_state != PMC_STATE_STOPPED && 4365 pm->pm_state != PMC_STATE_RUNNING) { 4366 error = EINVAL; 4367 break; 4368 } 4369 4370 /* writing a new value is allowed only for 'STOPPED' pmcs */ 4371 if (pm->pm_state == PMC_STATE_RUNNING && 4372 (prw.pm_flags & PMC_F_NEWVALUE)) { 4373 error = EBUSY; 4374 break; 4375 } 4376 4377 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) { 4378 4379 /* 4380 * If this PMC is attached to its owner (i.e., 4381 * the process requesting this operation) and 4382 * is running, then attempt to get an 4383 * upto-date reading from hardware for a READ. 4384 * Writes are only allowed when the PMC is 4385 * stopped, so only update the saved value 4386 * field. 4387 * 4388 * If the PMC is not running, or is not 4389 * attached to its owner, read/write to the 4390 * savedvalue field. 4391 */ 4392 4393 ri = PMC_TO_ROWINDEX(pm); 4394 pcd = pmc_ri_to_classdep(md, ri, &adjri); 4395 4396 mtx_pool_lock_spin(pmc_mtxpool, pm); 4397 cpu = curthread->td_oncpu; 4398 4399 if (prw.pm_flags & PMC_F_OLDVALUE) { 4400 if ((pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) && 4401 (pm->pm_state == PMC_STATE_RUNNING)) 4402 error = (*pcd->pcd_read_pmc)(cpu, adjri, 4403 &oldvalue); 4404 else 4405 oldvalue = pm->pm_gv.pm_savedvalue; 4406 } 4407 if (prw.pm_flags & PMC_F_NEWVALUE) 4408 pm->pm_gv.pm_savedvalue = prw.pm_value; 4409 4410 mtx_pool_unlock_spin(pmc_mtxpool, pm); 4411 4412 } else { /* System mode PMCs */ 4413 cpu = PMC_TO_CPU(pm); 4414 ri = PMC_TO_ROWINDEX(pm); 4415 pcd = pmc_ri_to_classdep(md, ri, &adjri); 4416 4417 if (!pmc_cpu_is_active(cpu)) { 4418 error = ENXIO; 4419 break; 4420 } 4421 4422 /* move this thread to CPU 'cpu' */ 4423 pmc_save_cpu_binding(&pb); 4424 pmc_select_cpu(cpu); 4425 4426 critical_enter(); 4427 /* save old value */ 4428 if (prw.pm_flags & PMC_F_OLDVALUE) 4429 if ((error = (*pcd->pcd_read_pmc)(cpu, adjri, 4430 &oldvalue))) 4431 goto error; 4432 /* write out new value */ 4433 if (prw.pm_flags & PMC_F_NEWVALUE) 4434 error = (*pcd->pcd_write_pmc)(cpu, adjri, 4435 prw.pm_value); 4436 error: 4437 critical_exit(); 4438 pmc_restore_cpu_binding(&pb); 4439 if (error) 4440 break; 4441 } 4442 4443 pprw = (struct pmc_op_pmcrw *) arg; 4444 4445 #ifdef HWPMC_DEBUG 4446 if (prw.pm_flags & PMC_F_NEWVALUE) 4447 PMCDBG3(PMC,OPS,2, "rw id=%d new %jx -> old %jx", 4448 ri, prw.pm_value, oldvalue); 4449 else if (prw.pm_flags & PMC_F_OLDVALUE) 4450 PMCDBG2(PMC,OPS,2, "rw id=%d -> old %jx", ri, oldvalue); 4451 #endif 4452 4453 /* return old value if requested */ 4454 if (prw.pm_flags & PMC_F_OLDVALUE) 4455 if ((error = copyout(&oldvalue, &pprw->pm_value, 4456 sizeof(prw.pm_value)))) 4457 break; 4458 4459 } 4460 break; 4461 4462 4463 /* 4464 * Set the sampling rate for a sampling mode PMC and the 4465 * initial count for a counting mode PMC. 4466 */ 4467 4468 case PMC_OP_PMCSETCOUNT: 4469 { 4470 struct pmc *pm; 4471 struct pmc_op_pmcsetcount sc; 4472 4473 PMC_DOWNGRADE_SX(); 4474 4475 if ((error = copyin(arg, &sc, sizeof(sc))) != 0) 4476 break; 4477 4478 if ((error = pmc_find_pmc(sc.pm_pmcid, &pm)) != 0) 4479 break; 4480 4481 if (pm->pm_state == PMC_STATE_RUNNING) { 4482 error = EBUSY; 4483 break; 4484 } 4485 4486 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) { 4487 /* 4488 * Don't permit requested sample rate to be 4489 * less than pmc_mincount. 4490 */ 4491 if (sc.pm_count < MAX(1, pmc_mincount)) 4492 log(LOG_WARNING, "pmcsetcount: passed sample " 4493 "rate %ju - setting to %u\n", 4494 (uintmax_t)sc.pm_count, 4495 MAX(1, pmc_mincount)); 4496 pm->pm_sc.pm_reloadcount = MAX(MAX(1, pmc_mincount), 4497 sc.pm_count); 4498 } else 4499 pm->pm_sc.pm_initial = sc.pm_count; 4500 } 4501 break; 4502 4503 4504 /* 4505 * Start a PMC. 4506 */ 4507 4508 case PMC_OP_PMCSTART: 4509 { 4510 pmc_id_t pmcid; 4511 struct pmc *pm; 4512 struct pmc_op_simple sp; 4513 4514 sx_assert(&pmc_sx, SX_XLOCKED); 4515 4516 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 4517 break; 4518 4519 pmcid = sp.pm_pmcid; 4520 4521 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 4522 break; 4523 4524 KASSERT(pmcid == pm->pm_id, 4525 ("[pmc,%d] pmcid %x != id %x", __LINE__, 4526 pm->pm_id, pmcid)); 4527 4528 if (pm->pm_state == PMC_STATE_RUNNING) /* already running */ 4529 break; 4530 else if (pm->pm_state != PMC_STATE_STOPPED && 4531 pm->pm_state != PMC_STATE_ALLOCATED) { 4532 error = EINVAL; 4533 break; 4534 } 4535 4536 error = pmc_start(pm); 4537 } 4538 break; 4539 4540 4541 /* 4542 * Stop a PMC. 4543 */ 4544 4545 case PMC_OP_PMCSTOP: 4546 { 4547 pmc_id_t pmcid; 4548 struct pmc *pm; 4549 struct pmc_op_simple sp; 4550 4551 PMC_DOWNGRADE_SX(); 4552 4553 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 4554 break; 4555 4556 pmcid = sp.pm_pmcid; 4557 4558 /* 4559 * Mark the PMC as inactive and invoke the MD stop 4560 * routines if needed. 4561 */ 4562 4563 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 4564 break; 4565 4566 KASSERT(pmcid == pm->pm_id, 4567 ("[pmc,%d] pmc id %x != pmcid %x", __LINE__, 4568 pm->pm_id, pmcid)); 4569 4570 if (pm->pm_state == PMC_STATE_STOPPED) /* already stopped */ 4571 break; 4572 else if (pm->pm_state != PMC_STATE_RUNNING) { 4573 error = EINVAL; 4574 break; 4575 } 4576 4577 error = pmc_stop(pm); 4578 } 4579 break; 4580 4581 4582 /* 4583 * Write a user supplied value to the log file. 4584 */ 4585 4586 case PMC_OP_WRITELOG: 4587 { 4588 struct pmc_op_writelog wl; 4589 struct pmc_owner *po; 4590 4591 PMC_DOWNGRADE_SX(); 4592 4593 if ((error = copyin(arg, &wl, sizeof(wl))) != 0) 4594 break; 4595 4596 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 4597 error = EINVAL; 4598 break; 4599 } 4600 4601 if ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) { 4602 error = EINVAL; 4603 break; 4604 } 4605 4606 error = pmclog_process_userlog(po, &wl); 4607 } 4608 break; 4609 4610 4611 default: 4612 error = EINVAL; 4613 break; 4614 } 4615 4616 if (is_sx_downgraded) 4617 sx_sunlock(&pmc_sx); 4618 else 4619 sx_xunlock(&pmc_sx); 4620 done_syscall: 4621 if (error) 4622 counter_u64_add(pmc_stats.pm_syscall_errors, 1); 4623 4624 return (error); 4625 } 4626 4627 /* 4628 * Helper functions 4629 */ 4630 4631 4632 /* 4633 * Mark the thread as needing callchain capture and post an AST. The 4634 * actual callchain capture will be done in a context where it is safe 4635 * to take page faults. 4636 */ 4637 4638 static void 4639 pmc_post_callchain_callback(void) 4640 { 4641 struct thread *td; 4642 4643 td = curthread; 4644 4645 /* 4646 * If there is multiple PMCs for the same interrupt ignore new post 4647 */ 4648 if (td->td_pflags & TDP_CALLCHAIN) 4649 return; 4650 4651 /* 4652 * Mark this thread as needing callchain capture. 4653 * `td->td_pflags' will be safe to touch because this thread 4654 * was in user space when it was interrupted. 4655 */ 4656 td->td_pflags |= TDP_CALLCHAIN; 4657 4658 /* 4659 * Don't let this thread migrate between CPUs until callchain 4660 * capture completes. 4661 */ 4662 sched_pin(); 4663 4664 return; 4665 } 4666 4667 /* 4668 * Find a free slot in the per-cpu array of samples and capture the 4669 * current callchain there. If a sample was successfully added, a bit 4670 * is set in mask 'pmc_cpumask' denoting that the DO_SAMPLES hook 4671 * needs to be invoked from the clock handler. 4672 * 4673 * This function is meant to be called from an NMI handler. It cannot 4674 * use any of the locking primitives supplied by the OS. 4675 */ 4676 4677 static int 4678 pmc_add_sample(ring_type_t ring, struct pmc *pm, struct trapframe *tf) 4679 { 4680 int error, cpu, callchaindepth, inuserspace; 4681 struct thread *td; 4682 struct pmc_sample *ps; 4683 struct pmc_samplebuffer *psb; 4684 4685 error = 0; 4686 4687 /* 4688 * Allocate space for a sample buffer. 4689 */ 4690 cpu = curcpu; 4691 psb = pmc_pcpu[cpu]->pc_sb[ring]; 4692 inuserspace = TRAPF_USERMODE(tf); 4693 ps = PMC_PROD_SAMPLE(psb); 4694 if (psb->ps_considx != psb->ps_prodidx && 4695 ps->ps_nsamples) { /* in use, reader hasn't caught up */ 4696 pm->pm_pcpu_state[cpu].pps_stalled = 1; 4697 counter_u64_add(pmc_stats.pm_intr_bufferfull, 1); 4698 PMCDBG6(SAM,INT,1,"(spc) cpu=%d pm=%p tf=%p um=%d wr=%d rd=%d", 4699 cpu, pm, (void *) tf, inuserspace, 4700 (int) (psb->ps_prodidx & pmc_sample_mask), 4701 (int) (psb->ps_considx & pmc_sample_mask)); 4702 callchaindepth = 1; 4703 error = ENOMEM; 4704 goto done; 4705 } 4706 4707 /* Fill in entry. */ 4708 PMCDBG6(SAM,INT,1,"cpu=%d pm=%p tf=%p um=%d wr=%d rd=%d", cpu, pm, 4709 (void *) tf, inuserspace, 4710 (int) (psb->ps_prodidx & pmc_sample_mask), 4711 (int) (psb->ps_considx & pmc_sample_mask)); 4712 4713 td = curthread; 4714 ps->ps_pmc = pm; 4715 ps->ps_td = td; 4716 ps->ps_pid = td->td_proc->p_pid; 4717 ps->ps_tid = td->td_tid; 4718 ps->ps_tsc = pmc_rdtsc(); 4719 ps->ps_ticks = ticks; 4720 ps->ps_cpu = cpu; 4721 ps->ps_flags = inuserspace ? PMC_CC_F_USERSPACE : 0; 4722 4723 callchaindepth = (pm->pm_flags & PMC_F_CALLCHAIN) ? 4724 pmc_callchaindepth : 1; 4725 4726 MPASS(ps->ps_pc != NULL); 4727 if (callchaindepth == 1) 4728 ps->ps_pc[0] = PMC_TRAPFRAME_TO_PC(tf); 4729 else { 4730 /* 4731 * Kernel stack traversals can be done immediately, 4732 * while we defer to an AST for user space traversals. 4733 */ 4734 if (!inuserspace) { 4735 callchaindepth = 4736 pmc_save_kernel_callchain(ps->ps_pc, 4737 callchaindepth, tf); 4738 } else { 4739 pmc_post_callchain_callback(); 4740 callchaindepth = PMC_USER_CALLCHAIN_PENDING; 4741 } 4742 } 4743 4744 ps->ps_nsamples = callchaindepth; /* mark entry as in use */ 4745 if (ring == PMC_UR) { 4746 ps->ps_nsamples_actual = callchaindepth; /* mark entry as in use */ 4747 ps->ps_nsamples = PMC_USER_CALLCHAIN_PENDING; 4748 } else 4749 ps->ps_nsamples = callchaindepth; /* mark entry as in use */ 4750 4751 KASSERT(counter_u64_fetch(pm->pm_runcount) >= 0, 4752 ("[pmc,%d] pm=%p runcount %ld", __LINE__, (void *) pm, 4753 (unsigned long)counter_u64_fetch(pm->pm_runcount))); 4754 4755 counter_u64_add(pm->pm_runcount, 1); /* hold onto PMC */ 4756 /* increment write pointer */ 4757 psb->ps_prodidx++; 4758 done: 4759 /* mark CPU as needing processing */ 4760 if (callchaindepth != PMC_USER_CALLCHAIN_PENDING) 4761 DPCPU_SET(pmc_sampled, 1); 4762 4763 return (error); 4764 } 4765 4766 /* 4767 * Interrupt processing. 4768 * 4769 * This function is meant to be called from an NMI handler. It cannot 4770 * use any of the locking primitives supplied by the OS. 4771 */ 4772 4773 int 4774 pmc_process_interrupt(int ring, struct pmc *pm, struct trapframe *tf) 4775 { 4776 struct thread *td; 4777 4778 td = curthread; 4779 if ((pm->pm_flags & PMC_F_USERCALLCHAIN) && 4780 (td->td_proc->p_flag & P_KPROC) == 0 && 4781 !TRAPF_USERMODE(tf)) { 4782 atomic_add_int(&td->td_pmcpend, 1); 4783 return (pmc_add_sample(PMC_UR, pm, tf)); 4784 } 4785 return (pmc_add_sample(ring, pm, tf)); 4786 } 4787 4788 /* 4789 * Capture a user call chain. This function will be called from ast() 4790 * before control returns to userland and before the process gets 4791 * rescheduled. 4792 */ 4793 4794 static void 4795 pmc_capture_user_callchain(int cpu, int ring, struct trapframe *tf) 4796 { 4797 struct pmc *pm; 4798 struct thread *td; 4799 struct pmc_sample *ps; 4800 struct pmc_samplebuffer *psb; 4801 uint64_t considx, prodidx; 4802 int nsamples, nrecords, pass, iter; 4803 #ifdef INVARIANTS 4804 int start_ticks = ticks; 4805 #endif 4806 psb = pmc_pcpu[cpu]->pc_sb[ring]; 4807 td = curthread; 4808 4809 KASSERT(td->td_pflags & TDP_CALLCHAIN, 4810 ("[pmc,%d] Retrieving callchain for thread that doesn't want it", 4811 __LINE__)); 4812 4813 nrecords = INT_MAX; 4814 pass = 0; 4815 restart: 4816 if (ring == PMC_UR) 4817 nrecords = atomic_readandclear_32(&td->td_pmcpend); 4818 4819 for (iter = 0, considx = psb->ps_considx, prodidx = psb->ps_prodidx; 4820 considx < prodidx && iter < pmc_nsamples; considx++, iter++) { 4821 ps = PMC_CONS_SAMPLE_OFF(psb, considx); 4822 4823 /* 4824 * Iterate through all deferred callchain requests. 4825 * Walk from the current read pointer to the current 4826 * write pointer. 4827 */ 4828 4829 #ifdef INVARIANTS 4830 if (ps->ps_nsamples == PMC_SAMPLE_FREE) { 4831 continue; 4832 } 4833 #endif 4834 if (ps->ps_td != td || 4835 ps->ps_nsamples != PMC_USER_CALLCHAIN_PENDING || 4836 ps->ps_pmc->pm_state != PMC_STATE_RUNNING) 4837 continue; 4838 4839 KASSERT(ps->ps_cpu == cpu, 4840 ("[pmc,%d] cpu mismatch ps_cpu=%d pcpu=%d", __LINE__, 4841 ps->ps_cpu, PCPU_GET(cpuid))); 4842 4843 pm = ps->ps_pmc; 4844 4845 KASSERT(pm->pm_flags & PMC_F_CALLCHAIN, 4846 ("[pmc,%d] Retrieving callchain for PMC that doesn't " 4847 "want it", __LINE__)); 4848 4849 KASSERT(counter_u64_fetch(pm->pm_runcount) > 0, 4850 ("[pmc,%d] runcount %ld", __LINE__, (unsigned long)counter_u64_fetch(pm->pm_runcount))); 4851 4852 if (ring == PMC_UR) { 4853 nsamples = ps->ps_nsamples_actual; 4854 counter_u64_add(pmc_stats.pm_merges, 1); 4855 } else 4856 nsamples = 0; 4857 4858 /* 4859 * Retrieve the callchain and mark the sample buffer 4860 * as 'processable' by the timer tick sweep code. 4861 */ 4862 4863 if (__predict_true(nsamples < pmc_callchaindepth - 1)) 4864 nsamples += pmc_save_user_callchain(ps->ps_pc + nsamples, 4865 pmc_callchaindepth - nsamples - 1, tf); 4866 4867 /* 4868 * We have to prevent hardclock from potentially overwriting 4869 * this sample between when we read the value and when we set 4870 * it 4871 */ 4872 spinlock_enter(); 4873 /* 4874 * Verify that the sample hasn't been dropped in the meantime 4875 */ 4876 if (ps->ps_nsamples == PMC_USER_CALLCHAIN_PENDING) { 4877 ps->ps_nsamples = nsamples; 4878 /* 4879 * If we couldn't get a sample, simply drop the reference 4880 */ 4881 if (nsamples == 0) 4882 counter_u64_add(pm->pm_runcount, -1); 4883 } 4884 spinlock_exit(); 4885 if (nrecords-- == 1) 4886 break; 4887 } 4888 if (__predict_false(ring == PMC_UR && td->td_pmcpend)) { 4889 if (pass == 0) { 4890 pass = 1; 4891 goto restart; 4892 } 4893 /* only collect samples for this part once */ 4894 td->td_pmcpend = 0; 4895 } 4896 4897 #ifdef INVARIANTS 4898 if ((ticks - start_ticks) > hz) 4899 log(LOG_ERR, "%s took %d ticks\n", __func__, (ticks - start_ticks)); 4900 #endif 4901 4902 /* mark CPU as needing processing */ 4903 DPCPU_SET(pmc_sampled, 1); 4904 } 4905 4906 /* 4907 * Process saved PC samples. 4908 */ 4909 4910 static void 4911 pmc_process_samples(int cpu, ring_type_t ring) 4912 { 4913 struct pmc *pm; 4914 int adjri, n; 4915 struct thread *td; 4916 struct pmc_owner *po; 4917 struct pmc_sample *ps; 4918 struct pmc_classdep *pcd; 4919 struct pmc_samplebuffer *psb; 4920 uint64_t delta __diagused; 4921 4922 KASSERT(PCPU_GET(cpuid) == cpu, 4923 ("[pmc,%d] not on the correct CPU pcpu=%d cpu=%d", __LINE__, 4924 PCPU_GET(cpuid), cpu)); 4925 4926 psb = pmc_pcpu[cpu]->pc_sb[ring]; 4927 delta = psb->ps_prodidx - psb->ps_considx; 4928 MPASS(delta <= pmc_nsamples); 4929 MPASS(psb->ps_considx <= psb->ps_prodidx); 4930 for (n = 0; psb->ps_considx < psb->ps_prodidx; psb->ps_considx++, n++) { 4931 ps = PMC_CONS_SAMPLE(psb); 4932 4933 if (__predict_false(ps->ps_nsamples == PMC_SAMPLE_FREE)) 4934 continue; 4935 pm = ps->ps_pmc; 4936 /* skip non-running samples */ 4937 if (pm->pm_state != PMC_STATE_RUNNING) 4938 goto entrydone; 4939 4940 KASSERT(counter_u64_fetch(pm->pm_runcount) > 0, 4941 ("[pmc,%d] pm=%p runcount %ld", __LINE__, (void *) pm, 4942 (unsigned long)counter_u64_fetch(pm->pm_runcount))); 4943 4944 po = pm->pm_owner; 4945 4946 KASSERT(PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)), 4947 ("[pmc,%d] pmc=%p non-sampling mode=%d", __LINE__, 4948 pm, PMC_TO_MODE(pm))); 4949 4950 4951 /* If there is a pending AST wait for completion */ 4952 if (ps->ps_nsamples == PMC_USER_CALLCHAIN_PENDING) { 4953 /* if we've been waiting more than 1 tick to 4954 * collect a callchain for this record then 4955 * drop it and move on. 4956 */ 4957 if (ticks - ps->ps_ticks > 1) { 4958 /* 4959 * track how often we hit this as it will 4960 * preferentially lose user samples 4961 * for long running system calls 4962 */ 4963 counter_u64_add(pmc_stats.pm_overwrites, 1); 4964 goto entrydone; 4965 } 4966 /* Need a rescan at a later time. */ 4967 DPCPU_SET(pmc_sampled, 1); 4968 break; 4969 } 4970 4971 PMCDBG6(SAM,OPS,1,"cpu=%d pm=%p n=%d fl=%x wr=%d rd=%d", cpu, 4972 pm, ps->ps_nsamples, ps->ps_flags, 4973 (int) (psb->ps_prodidx & pmc_sample_mask), 4974 (int) (psb->ps_considx & pmc_sample_mask)); 4975 4976 /* 4977 * If this is a process-mode PMC that is attached to 4978 * its owner, and if the PC is in user mode, update 4979 * profiling statistics like timer-based profiling 4980 * would have done. 4981 * 4982 * Otherwise, this is either a sampling-mode PMC that 4983 * is attached to a different process than its owner, 4984 * or a system-wide sampling PMC. Dispatch a log 4985 * entry to the PMC's owner process. 4986 */ 4987 if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) { 4988 if (ps->ps_flags & PMC_CC_F_USERSPACE) { 4989 td = FIRST_THREAD_IN_PROC(po->po_owner); 4990 addupc_intr(td, ps->ps_pc[0], 1); 4991 } 4992 } else 4993 pmclog_process_callchain(pm, ps); 4994 4995 entrydone: 4996 ps->ps_nsamples = 0; /* mark entry as free */ 4997 KASSERT(counter_u64_fetch(pm->pm_runcount) > 0, 4998 ("[pmc,%d] pm=%p runcount %ld", __LINE__, (void *) pm, 4999 (unsigned long)counter_u64_fetch(pm->pm_runcount))); 5000 5001 counter_u64_add(pm->pm_runcount, -1); 5002 } 5003 5004 counter_u64_add(pmc_stats.pm_log_sweeps, 1); 5005 5006 /* Do not re-enable stalled PMCs if we failed to process any samples */ 5007 if (n == 0) 5008 return; 5009 5010 /* 5011 * Restart any stalled sampling PMCs on this CPU. 5012 * 5013 * If the NMI handler sets the pm_stalled field of a PMC after 5014 * the check below, we'll end up processing the stalled PMC at 5015 * the next hardclock tick. 5016 */ 5017 for (n = 0; n < md->pmd_npmc; n++) { 5018 pcd = pmc_ri_to_classdep(md, n, &adjri); 5019 KASSERT(pcd != NULL, 5020 ("[pmc,%d] null pcd ri=%d", __LINE__, n)); 5021 (void) (*pcd->pcd_get_config)(cpu,adjri,&pm); 5022 5023 if (pm == NULL || /* !cfg'ed */ 5024 pm->pm_state != PMC_STATE_RUNNING || /* !active */ 5025 !PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)) || /* !sampling */ 5026 !pm->pm_pcpu_state[cpu].pps_cpustate || /* !desired */ 5027 !pm->pm_pcpu_state[cpu].pps_stalled) /* !stalled */ 5028 continue; 5029 5030 pm->pm_pcpu_state[cpu].pps_stalled = 0; 5031 (*pcd->pcd_start_pmc)(cpu, adjri); 5032 } 5033 } 5034 5035 /* 5036 * Event handlers. 5037 */ 5038 5039 /* 5040 * Handle a process exit. 5041 * 5042 * Remove this process from all hash tables. If this process 5043 * owned any PMCs, turn off those PMCs and deallocate them, 5044 * removing any associations with target processes. 5045 * 5046 * This function will be called by the last 'thread' of a 5047 * process. 5048 * 5049 * XXX This eventhandler gets called early in the exit process. 5050 * Consider using a 'hook' invocation from thread_exit() or equivalent 5051 * spot. Another negative is that kse_exit doesn't seem to call 5052 * exit1() [??]. 5053 * 5054 */ 5055 5056 static void 5057 pmc_process_exit(void *arg __unused, struct proc *p) 5058 { 5059 struct pmc *pm; 5060 int adjri, cpu; 5061 unsigned int ri; 5062 int is_using_hwpmcs; 5063 struct pmc_owner *po; 5064 struct pmc_process *pp; 5065 struct pmc_classdep *pcd; 5066 pmc_value_t newvalue, tmp; 5067 5068 PROC_LOCK(p); 5069 is_using_hwpmcs = p->p_flag & P_HWPMC; 5070 PROC_UNLOCK(p); 5071 5072 /* 5073 * Log a sysexit event to all SS PMC owners. 5074 */ 5075 PMC_EPOCH_ENTER(); 5076 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 5077 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 5078 pmclog_process_sysexit(po, p->p_pid); 5079 PMC_EPOCH_EXIT(); 5080 5081 if (!is_using_hwpmcs) 5082 return; 5083 5084 PMC_GET_SX_XLOCK(); 5085 PMCDBG3(PRC,EXT,1,"process-exit proc=%p (%d, %s)", p, p->p_pid, 5086 p->p_comm); 5087 5088 /* 5089 * Since this code is invoked by the last thread in an exiting 5090 * process, we would have context switched IN at some prior 5091 * point. However, with PREEMPTION, kernel mode context 5092 * switches may happen any time, so we want to disable a 5093 * context switch OUT till we get any PMCs targeting this 5094 * process off the hardware. 5095 * 5096 * We also need to atomically remove this process' 5097 * entry from our target process hash table, using 5098 * PMC_FLAG_REMOVE. 5099 */ 5100 PMCDBG3(PRC,EXT,1, "process-exit proc=%p (%d, %s)", p, p->p_pid, 5101 p->p_comm); 5102 5103 critical_enter(); /* no preemption */ 5104 5105 cpu = curthread->td_oncpu; 5106 5107 if ((pp = pmc_find_process_descriptor(p, 5108 PMC_FLAG_REMOVE)) != NULL) { 5109 5110 PMCDBG2(PRC,EXT,2, 5111 "process-exit proc=%p pmc-process=%p", p, pp); 5112 5113 /* 5114 * The exiting process could the target of 5115 * some PMCs which will be running on 5116 * currently executing CPU. 5117 * 5118 * We need to turn these PMCs off like we 5119 * would do at context switch OUT time. 5120 */ 5121 for (ri = 0; ri < md->pmd_npmc; ri++) { 5122 5123 /* 5124 * Pick up the pmc pointer from hardware 5125 * state similar to the CSW_OUT code. 5126 */ 5127 pm = NULL; 5128 5129 pcd = pmc_ri_to_classdep(md, ri, &adjri); 5130 5131 (void) (*pcd->pcd_get_config)(cpu, adjri, &pm); 5132 5133 PMCDBG2(PRC,EXT,2, "ri=%d pm=%p", ri, pm); 5134 5135 if (pm == NULL || 5136 !PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) 5137 continue; 5138 5139 PMCDBG4(PRC,EXT,2, "ppmcs[%d]=%p pm=%p " 5140 "state=%d", ri, pp->pp_pmcs[ri].pp_pmc, 5141 pm, pm->pm_state); 5142 5143 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 5144 ("[pmc,%d] ri mismatch pmc(%d) ri(%d)", 5145 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 5146 5147 KASSERT(pm == pp->pp_pmcs[ri].pp_pmc, 5148 ("[pmc,%d] pm %p != pp_pmcs[%d] %p", 5149 __LINE__, pm, ri, pp->pp_pmcs[ri].pp_pmc)); 5150 5151 KASSERT(counter_u64_fetch(pm->pm_runcount) > 0, 5152 ("[pmc,%d] bad runcount ri %d rc %ld", 5153 __LINE__, ri, (unsigned long)counter_u64_fetch(pm->pm_runcount))); 5154 5155 /* 5156 * Change desired state, and then stop if not 5157 * stalled. This two-step dance should avoid 5158 * race conditions where an interrupt re-enables 5159 * the PMC after this code has already checked 5160 * the pm_stalled flag. 5161 */ 5162 if (pm->pm_pcpu_state[cpu].pps_cpustate) { 5163 pm->pm_pcpu_state[cpu].pps_cpustate = 0; 5164 if (!pm->pm_pcpu_state[cpu].pps_stalled) { 5165 (void) pcd->pcd_stop_pmc(cpu, adjri); 5166 5167 if (PMC_TO_MODE(pm) == PMC_MODE_TC) { 5168 pcd->pcd_read_pmc(cpu, adjri, 5169 &newvalue); 5170 tmp = newvalue - 5171 PMC_PCPU_SAVED(cpu,ri); 5172 5173 mtx_pool_lock_spin(pmc_mtxpool, 5174 pm); 5175 pm->pm_gv.pm_savedvalue += tmp; 5176 pp->pp_pmcs[ri].pp_pmcval += 5177 tmp; 5178 mtx_pool_unlock_spin( 5179 pmc_mtxpool, pm); 5180 } 5181 } 5182 } 5183 5184 KASSERT((int64_t) counter_u64_fetch(pm->pm_runcount) > 0, 5185 ("[pmc,%d] runcount is %d", __LINE__, ri)); 5186 5187 counter_u64_add(pm->pm_runcount, -1); 5188 5189 (void) pcd->pcd_config_pmc(cpu, adjri, NULL); 5190 } 5191 5192 /* 5193 * Inform the MD layer of this pseudo "context switch 5194 * out" 5195 */ 5196 (void) md->pmd_switch_out(pmc_pcpu[cpu], pp); 5197 5198 critical_exit(); /* ok to be pre-empted now */ 5199 5200 /* 5201 * Unlink this process from the PMCs that are 5202 * targeting it. This will send a signal to 5203 * all PMC owner's whose PMCs are orphaned. 5204 * 5205 * Log PMC value at exit time if requested. 5206 */ 5207 for (ri = 0; ri < md->pmd_npmc; ri++) 5208 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) { 5209 if (pm->pm_flags & PMC_F_NEEDS_LOGFILE && 5210 PMC_IS_COUNTING_MODE(PMC_TO_MODE(pm))) 5211 pmclog_process_procexit(pm, pp); 5212 pmc_unlink_target_process(pm, pp); 5213 } 5214 free(pp, M_PMC); 5215 5216 } else 5217 critical_exit(); /* pp == NULL */ 5218 5219 5220 /* 5221 * If the process owned PMCs, free them up and free up 5222 * memory. 5223 */ 5224 if ((po = pmc_find_owner_descriptor(p)) != NULL) { 5225 pmc_remove_owner(po); 5226 pmc_destroy_owner_descriptor(po); 5227 } 5228 5229 sx_xunlock(&pmc_sx); 5230 } 5231 5232 /* 5233 * Handle a process fork. 5234 * 5235 * If the parent process 'p1' is under HWPMC monitoring, then copy 5236 * over any attached PMCs that have 'do_descendants' semantics. 5237 */ 5238 5239 static void 5240 pmc_process_fork(void *arg __unused, struct proc *p1, struct proc *newproc, 5241 int flags) 5242 { 5243 int is_using_hwpmcs; 5244 unsigned int ri; 5245 uint32_t do_descendants; 5246 struct pmc *pm; 5247 struct pmc_owner *po; 5248 struct pmc_process *ppnew, *ppold; 5249 5250 (void) flags; /* unused parameter */ 5251 5252 PROC_LOCK(p1); 5253 is_using_hwpmcs = p1->p_flag & P_HWPMC; 5254 PROC_UNLOCK(p1); 5255 5256 /* 5257 * If there are system-wide sampling PMCs active, we need to 5258 * log all fork events to their owner's logs. 5259 */ 5260 PMC_EPOCH_ENTER(); 5261 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 5262 if (po->po_flags & PMC_PO_OWNS_LOGFILE) { 5263 pmclog_process_procfork(po, p1->p_pid, newproc->p_pid); 5264 pmclog_process_proccreate(po, newproc, 1); 5265 } 5266 PMC_EPOCH_EXIT(); 5267 5268 if (!is_using_hwpmcs) 5269 return; 5270 5271 PMC_GET_SX_XLOCK(); 5272 PMCDBG4(PMC,FRK,1, "process-fork proc=%p (%d, %s) -> %p", p1, 5273 p1->p_pid, p1->p_comm, newproc); 5274 5275 /* 5276 * If the parent process (curthread->td_proc) is a 5277 * target of any PMCs, look for PMCs that are to be 5278 * inherited, and link these into the new process 5279 * descriptor. 5280 */ 5281 if ((ppold = pmc_find_process_descriptor(curthread->td_proc, 5282 PMC_FLAG_NONE)) == NULL) 5283 goto done; /* nothing to do */ 5284 5285 do_descendants = 0; 5286 for (ri = 0; ri < md->pmd_npmc; ri++) 5287 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL) 5288 do_descendants |= pm->pm_flags & PMC_F_DESCENDANTS; 5289 if (do_descendants == 0) /* nothing to do */ 5290 goto done; 5291 5292 /* 5293 * Now mark the new process as being tracked by this driver. 5294 */ 5295 PROC_LOCK(newproc); 5296 newproc->p_flag |= P_HWPMC; 5297 PROC_UNLOCK(newproc); 5298 5299 /* allocate a descriptor for the new process */ 5300 if ((ppnew = pmc_find_process_descriptor(newproc, 5301 PMC_FLAG_ALLOCATE)) == NULL) 5302 goto done; 5303 5304 /* 5305 * Run through all PMCs that were targeting the old process 5306 * and which specified F_DESCENDANTS and attach them to the 5307 * new process. 5308 * 5309 * Log the fork event to all owners of PMCs attached to this 5310 * process, if not already logged. 5311 */ 5312 for (ri = 0; ri < md->pmd_npmc; ri++) 5313 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL && 5314 (pm->pm_flags & PMC_F_DESCENDANTS)) { 5315 pmc_link_target_process(pm, ppnew); 5316 po = pm->pm_owner; 5317 if (po->po_sscount == 0 && 5318 po->po_flags & PMC_PO_OWNS_LOGFILE) 5319 pmclog_process_procfork(po, p1->p_pid, 5320 newproc->p_pid); 5321 } 5322 5323 done: 5324 sx_xunlock(&pmc_sx); 5325 } 5326 5327 static void 5328 pmc_process_threadcreate(struct thread *td) 5329 { 5330 struct pmc_owner *po; 5331 5332 PMC_EPOCH_ENTER(); 5333 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 5334 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 5335 pmclog_process_threadcreate(po, td, 1); 5336 PMC_EPOCH_EXIT(); 5337 } 5338 5339 static void 5340 pmc_process_threadexit(struct thread *td) 5341 { 5342 struct pmc_owner *po; 5343 5344 PMC_EPOCH_ENTER(); 5345 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 5346 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 5347 pmclog_process_threadexit(po, td); 5348 PMC_EPOCH_EXIT(); 5349 } 5350 5351 static void 5352 pmc_process_proccreate(struct proc *p) 5353 { 5354 struct pmc_owner *po; 5355 5356 PMC_EPOCH_ENTER(); 5357 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 5358 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 5359 pmclog_process_proccreate(po, p, 1 /* sync */); 5360 PMC_EPOCH_EXIT(); 5361 } 5362 5363 static void 5364 pmc_process_allproc(struct pmc *pm) 5365 { 5366 struct pmc_owner *po; 5367 struct thread *td; 5368 struct proc *p; 5369 5370 po = pm->pm_owner; 5371 if ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) 5372 return; 5373 sx_slock(&allproc_lock); 5374 FOREACH_PROC_IN_SYSTEM(p) { 5375 pmclog_process_proccreate(po, p, 0 /* sync */); 5376 PROC_LOCK(p); 5377 FOREACH_THREAD_IN_PROC(p, td) 5378 pmclog_process_threadcreate(po, td, 0 /* sync */); 5379 PROC_UNLOCK(p); 5380 } 5381 sx_sunlock(&allproc_lock); 5382 pmclog_flush(po, 0); 5383 } 5384 5385 static void 5386 pmc_kld_load(void *arg __unused, linker_file_t lf) 5387 { 5388 struct pmc_owner *po; 5389 5390 /* 5391 * Notify owners of system sampling PMCs about KLD operations. 5392 */ 5393 PMC_EPOCH_ENTER(); 5394 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 5395 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 5396 pmclog_process_map_in(po, (pid_t) -1, 5397 (uintfptr_t) lf->address, lf->filename); 5398 PMC_EPOCH_EXIT(); 5399 5400 /* 5401 * TODO: Notify owners of (all) process-sampling PMCs too. 5402 */ 5403 } 5404 5405 static void 5406 pmc_kld_unload(void *arg __unused, const char *filename __unused, 5407 caddr_t address, size_t size) 5408 { 5409 struct pmc_owner *po; 5410 5411 PMC_EPOCH_ENTER(); 5412 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 5413 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 5414 pmclog_process_map_out(po, (pid_t) -1, 5415 (uintfptr_t) address, (uintfptr_t) address + size); 5416 PMC_EPOCH_EXIT(); 5417 5418 /* 5419 * TODO: Notify owners of process-sampling PMCs. 5420 */ 5421 } 5422 5423 /* 5424 * initialization 5425 */ 5426 static const char * 5427 pmc_name_of_pmcclass(enum pmc_class class) 5428 { 5429 5430 switch (class) { 5431 #undef __PMC_CLASS 5432 #define __PMC_CLASS(S,V,D) \ 5433 case PMC_CLASS_##S: \ 5434 return #S; 5435 __PMC_CLASSES(); 5436 default: 5437 return ("<unknown>"); 5438 } 5439 } 5440 5441 /* 5442 * Base class initializer: allocate structure and set default classes. 5443 */ 5444 struct pmc_mdep * 5445 pmc_mdep_alloc(int nclasses) 5446 { 5447 struct pmc_mdep *md; 5448 int n; 5449 5450 /* SOFT + md classes */ 5451 n = 1 + nclasses; 5452 md = malloc(sizeof(struct pmc_mdep) + n * 5453 sizeof(struct pmc_classdep), M_PMC, M_WAITOK|M_ZERO); 5454 md->pmd_nclass = n; 5455 5456 /* Add base class. */ 5457 pmc_soft_initialize(md); 5458 return md; 5459 } 5460 5461 void 5462 pmc_mdep_free(struct pmc_mdep *md) 5463 { 5464 pmc_soft_finalize(md); 5465 free(md, M_PMC); 5466 } 5467 5468 static int 5469 generic_switch_in(struct pmc_cpu *pc, struct pmc_process *pp) 5470 { 5471 (void) pc; (void) pp; 5472 5473 return (0); 5474 } 5475 5476 static int 5477 generic_switch_out(struct pmc_cpu *pc, struct pmc_process *pp) 5478 { 5479 (void) pc; (void) pp; 5480 5481 return (0); 5482 } 5483 5484 static struct pmc_mdep * 5485 pmc_generic_cpu_initialize(void) 5486 { 5487 struct pmc_mdep *md; 5488 5489 md = pmc_mdep_alloc(0); 5490 5491 md->pmd_cputype = PMC_CPU_GENERIC; 5492 5493 md->pmd_pcpu_init = NULL; 5494 md->pmd_pcpu_fini = NULL; 5495 md->pmd_switch_in = generic_switch_in; 5496 md->pmd_switch_out = generic_switch_out; 5497 5498 return (md); 5499 } 5500 5501 static void 5502 pmc_generic_cpu_finalize(struct pmc_mdep *md) 5503 { 5504 (void) md; 5505 } 5506 5507 5508 static int 5509 pmc_initialize(void) 5510 { 5511 int c, cpu, error, n, ri; 5512 unsigned int maxcpu, domain; 5513 struct pcpu *pc; 5514 struct pmc_binding pb; 5515 struct pmc_sample *ps; 5516 struct pmc_classdep *pcd; 5517 struct pmc_samplebuffer *sb; 5518 5519 md = NULL; 5520 error = 0; 5521 5522 pmc_stats.pm_intr_ignored = counter_u64_alloc(M_WAITOK); 5523 pmc_stats.pm_intr_processed = counter_u64_alloc(M_WAITOK); 5524 pmc_stats.pm_intr_bufferfull = counter_u64_alloc(M_WAITOK); 5525 pmc_stats.pm_syscalls = counter_u64_alloc(M_WAITOK); 5526 pmc_stats.pm_syscall_errors = counter_u64_alloc(M_WAITOK); 5527 pmc_stats.pm_buffer_requests = counter_u64_alloc(M_WAITOK); 5528 pmc_stats.pm_buffer_requests_failed = counter_u64_alloc(M_WAITOK); 5529 pmc_stats.pm_log_sweeps = counter_u64_alloc(M_WAITOK); 5530 pmc_stats.pm_merges = counter_u64_alloc(M_WAITOK); 5531 pmc_stats.pm_overwrites = counter_u64_alloc(M_WAITOK); 5532 5533 #ifdef HWPMC_DEBUG 5534 /* parse debug flags first */ 5535 if (TUNABLE_STR_FETCH(PMC_SYSCTL_NAME_PREFIX "debugflags", 5536 pmc_debugstr, sizeof(pmc_debugstr))) 5537 pmc_debugflags_parse(pmc_debugstr, 5538 pmc_debugstr+strlen(pmc_debugstr)); 5539 #endif 5540 5541 PMCDBG1(MOD,INI,0, "PMC Initialize (version %x)", PMC_VERSION); 5542 5543 /* check kernel version */ 5544 if (pmc_kernel_version != PMC_VERSION) { 5545 if (pmc_kernel_version == 0) 5546 printf("hwpmc: this kernel has not been compiled with " 5547 "'options HWPMC_HOOKS'.\n"); 5548 else 5549 printf("hwpmc: kernel version (0x%x) does not match " 5550 "module version (0x%x).\n", pmc_kernel_version, 5551 PMC_VERSION); 5552 return EPROGMISMATCH; 5553 } 5554 5555 /* 5556 * check sysctl parameters 5557 */ 5558 5559 if (pmc_hashsize <= 0) { 5560 (void) printf("hwpmc: tunable \"hashsize\"=%d must be " 5561 "greater than zero.\n", pmc_hashsize); 5562 pmc_hashsize = PMC_HASH_SIZE; 5563 } 5564 5565 if (pmc_nsamples <= 0 || pmc_nsamples > 65535) { 5566 (void) printf("hwpmc: tunable \"nsamples\"=%d out of " 5567 "range.\n", pmc_nsamples); 5568 pmc_nsamples = PMC_NSAMPLES; 5569 } 5570 pmc_sample_mask = pmc_nsamples-1; 5571 5572 if (pmc_callchaindepth <= 0 || 5573 pmc_callchaindepth > PMC_CALLCHAIN_DEPTH_MAX) { 5574 (void) printf("hwpmc: tunable \"callchaindepth\"=%d out of " 5575 "range - using %d.\n", pmc_callchaindepth, 5576 PMC_CALLCHAIN_DEPTH_MAX); 5577 pmc_callchaindepth = PMC_CALLCHAIN_DEPTH_MAX; 5578 } 5579 5580 md = pmc_md_initialize(); 5581 if (md == NULL) { 5582 /* Default to generic CPU. */ 5583 md = pmc_generic_cpu_initialize(); 5584 if (md == NULL) 5585 return (ENOSYS); 5586 } 5587 5588 /* 5589 * Refresh classes base ri. Optional classes may come in different 5590 * order. 5591 */ 5592 for (ri = c = 0; c < md->pmd_nclass; c++) { 5593 pcd = &md->pmd_classdep[c]; 5594 pcd->pcd_ri = ri; 5595 ri += pcd->pcd_num; 5596 } 5597 5598 KASSERT(md->pmd_nclass >= 1 && md->pmd_npmc >= 1, 5599 ("[pmc,%d] no classes or pmcs", __LINE__)); 5600 5601 /* Compute the map from row-indices to classdep pointers. */ 5602 pmc_rowindex_to_classdep = malloc(sizeof(struct pmc_classdep *) * 5603 md->pmd_npmc, M_PMC, M_WAITOK|M_ZERO); 5604 5605 for (n = 0; n < md->pmd_npmc; n++) 5606 pmc_rowindex_to_classdep[n] = NULL; 5607 for (ri = c = 0; c < md->pmd_nclass; c++) { 5608 pcd = &md->pmd_classdep[c]; 5609 for (n = 0; n < pcd->pcd_num; n++, ri++) 5610 pmc_rowindex_to_classdep[ri] = pcd; 5611 } 5612 5613 KASSERT(ri == md->pmd_npmc, 5614 ("[pmc,%d] npmc miscomputed: ri=%d, md->npmc=%d", __LINE__, 5615 ri, md->pmd_npmc)); 5616 5617 maxcpu = pmc_cpu_max(); 5618 5619 /* allocate space for the per-cpu array */ 5620 pmc_pcpu = malloc(maxcpu * sizeof(struct pmc_cpu *), M_PMC, 5621 M_WAITOK|M_ZERO); 5622 5623 /* per-cpu 'saved values' for managing process-mode PMCs */ 5624 pmc_pcpu_saved = malloc(sizeof(pmc_value_t) * maxcpu * md->pmd_npmc, 5625 M_PMC, M_WAITOK); 5626 5627 /* Perform CPU-dependent initialization. */ 5628 pmc_save_cpu_binding(&pb); 5629 error = 0; 5630 for (cpu = 0; error == 0 && cpu < maxcpu; cpu++) { 5631 if (!pmc_cpu_is_active(cpu)) 5632 continue; 5633 pmc_select_cpu(cpu); 5634 pmc_pcpu[cpu] = malloc(sizeof(struct pmc_cpu) + 5635 md->pmd_npmc * sizeof(struct pmc_hw *), M_PMC, 5636 M_WAITOK|M_ZERO); 5637 if (md->pmd_pcpu_init) 5638 error = md->pmd_pcpu_init(md, cpu); 5639 for (n = 0; error == 0 && n < md->pmd_nclass; n++) 5640 if (md->pmd_classdep[n].pcd_num > 0) 5641 error = md->pmd_classdep[n].pcd_pcpu_init(md, 5642 cpu); 5643 } 5644 pmc_restore_cpu_binding(&pb); 5645 5646 if (error) 5647 return (error); 5648 5649 /* allocate space for the sample array */ 5650 for (cpu = 0; cpu < maxcpu; cpu++) { 5651 if (!pmc_cpu_is_active(cpu)) 5652 continue; 5653 pc = pcpu_find(cpu); 5654 domain = pc->pc_domain; 5655 sb = malloc_domainset(sizeof(struct pmc_samplebuffer) + 5656 pmc_nsamples * sizeof(struct pmc_sample), M_PMC, 5657 DOMAINSET_PREF(domain), M_WAITOK | M_ZERO); 5658 5659 KASSERT(pmc_pcpu[cpu] != NULL, 5660 ("[pmc,%d] cpu=%d Null per-cpu data", __LINE__, cpu)); 5661 5662 sb->ps_callchains = malloc_domainset(pmc_callchaindepth * 5663 pmc_nsamples * sizeof(uintptr_t), M_PMC, 5664 DOMAINSET_PREF(domain), M_WAITOK | M_ZERO); 5665 5666 for (n = 0, ps = sb->ps_samples; n < pmc_nsamples; n++, ps++) 5667 ps->ps_pc = sb->ps_callchains + 5668 (n * pmc_callchaindepth); 5669 5670 pmc_pcpu[cpu]->pc_sb[PMC_HR] = sb; 5671 5672 sb = malloc_domainset(sizeof(struct pmc_samplebuffer) + 5673 pmc_nsamples * sizeof(struct pmc_sample), M_PMC, 5674 DOMAINSET_PREF(domain), M_WAITOK | M_ZERO); 5675 5676 sb->ps_callchains = malloc_domainset(pmc_callchaindepth * 5677 pmc_nsamples * sizeof(uintptr_t), M_PMC, 5678 DOMAINSET_PREF(domain), M_WAITOK | M_ZERO); 5679 for (n = 0, ps = sb->ps_samples; n < pmc_nsamples; n++, ps++) 5680 ps->ps_pc = sb->ps_callchains + 5681 (n * pmc_callchaindepth); 5682 5683 pmc_pcpu[cpu]->pc_sb[PMC_SR] = sb; 5684 5685 sb = malloc_domainset(sizeof(struct pmc_samplebuffer) + 5686 pmc_nsamples * sizeof(struct pmc_sample), M_PMC, 5687 DOMAINSET_PREF(domain), M_WAITOK | M_ZERO); 5688 sb->ps_callchains = malloc_domainset(pmc_callchaindepth * 5689 pmc_nsamples * sizeof(uintptr_t), M_PMC, 5690 DOMAINSET_PREF(domain), M_WAITOK | M_ZERO); 5691 for (n = 0, ps = sb->ps_samples; n < pmc_nsamples; n++, ps++) 5692 ps->ps_pc = sb->ps_callchains + n * pmc_callchaindepth; 5693 5694 pmc_pcpu[cpu]->pc_sb[PMC_UR] = sb; 5695 } 5696 5697 /* allocate space for the row disposition array */ 5698 pmc_pmcdisp = malloc(sizeof(enum pmc_mode) * md->pmd_npmc, 5699 M_PMC, M_WAITOK|M_ZERO); 5700 5701 /* mark all PMCs as available */ 5702 for (n = 0; n < (int) md->pmd_npmc; n++) 5703 PMC_MARK_ROW_FREE(n); 5704 5705 /* allocate thread hash tables */ 5706 pmc_ownerhash = hashinit(pmc_hashsize, M_PMC, 5707 &pmc_ownerhashmask); 5708 5709 pmc_processhash = hashinit(pmc_hashsize, M_PMC, 5710 &pmc_processhashmask); 5711 mtx_init(&pmc_processhash_mtx, "pmc-process-hash", "pmc-leaf", 5712 MTX_SPIN); 5713 5714 CK_LIST_INIT(&pmc_ss_owners); 5715 pmc_ss_count = 0; 5716 5717 /* allocate a pool of spin mutexes */ 5718 pmc_mtxpool = mtx_pool_create("pmc-leaf", pmc_mtxpool_size, 5719 MTX_SPIN); 5720 5721 PMCDBG4(MOD,INI,1, "pmc_ownerhash=%p, mask=0x%lx " 5722 "targethash=%p mask=0x%lx", pmc_ownerhash, pmc_ownerhashmask, 5723 pmc_processhash, pmc_processhashmask); 5724 5725 /* Initialize a spin mutex for the thread free list. */ 5726 mtx_init(&pmc_threadfreelist_mtx, "pmc-threadfreelist", "pmc-leaf", 5727 MTX_SPIN); 5728 5729 /* Initialize the task to prune the thread free list. */ 5730 TASK_INIT(&free_task, 0, pmc_thread_descriptor_pool_free_task, NULL); 5731 5732 /* register process {exit,fork,exec} handlers */ 5733 pmc_exit_tag = EVENTHANDLER_REGISTER(process_exit, 5734 pmc_process_exit, NULL, EVENTHANDLER_PRI_ANY); 5735 pmc_fork_tag = EVENTHANDLER_REGISTER(process_fork, 5736 pmc_process_fork, NULL, EVENTHANDLER_PRI_ANY); 5737 5738 /* register kld event handlers */ 5739 pmc_kld_load_tag = EVENTHANDLER_REGISTER(kld_load, pmc_kld_load, 5740 NULL, EVENTHANDLER_PRI_ANY); 5741 pmc_kld_unload_tag = EVENTHANDLER_REGISTER(kld_unload, pmc_kld_unload, 5742 NULL, EVENTHANDLER_PRI_ANY); 5743 5744 /* initialize logging */ 5745 pmclog_initialize(); 5746 5747 /* set hook functions */ 5748 pmc_intr = md->pmd_intr; 5749 wmb(); 5750 pmc_hook = pmc_hook_handler; 5751 5752 if (error == 0) { 5753 printf(PMC_MODULE_NAME ":"); 5754 for (n = 0; n < (int) md->pmd_nclass; n++) { 5755 if (md->pmd_classdep[n].pcd_num == 0) 5756 continue; 5757 pcd = &md->pmd_classdep[n]; 5758 printf(" %s/%d/%d/0x%b", 5759 pmc_name_of_pmcclass(pcd->pcd_class), 5760 pcd->pcd_num, 5761 pcd->pcd_width, 5762 pcd->pcd_caps, 5763 "\20" 5764 "\1INT\2USR\3SYS\4EDG\5THR" 5765 "\6REA\7WRI\10INV\11QUA\12PRC" 5766 "\13TAG\14CSC"); 5767 } 5768 printf("\n"); 5769 } 5770 5771 return (error); 5772 } 5773 5774 /* prepare to be unloaded */ 5775 static void 5776 pmc_cleanup(void) 5777 { 5778 int c, cpu; 5779 unsigned int maxcpu; 5780 struct pmc_ownerhash *ph; 5781 struct pmc_owner *po, *tmp; 5782 struct pmc_binding pb; 5783 #ifdef HWPMC_DEBUG 5784 struct pmc_processhash *prh; 5785 #endif 5786 5787 PMCDBG0(MOD,INI,0, "cleanup"); 5788 5789 /* switch off sampling */ 5790 CPU_FOREACH(cpu) 5791 DPCPU_ID_SET(cpu, pmc_sampled, 0); 5792 pmc_intr = NULL; 5793 5794 sx_xlock(&pmc_sx); 5795 if (pmc_hook == NULL) { /* being unloaded already */ 5796 sx_xunlock(&pmc_sx); 5797 return; 5798 } 5799 5800 pmc_hook = NULL; /* prevent new threads from entering module */ 5801 5802 /* deregister event handlers */ 5803 EVENTHANDLER_DEREGISTER(process_fork, pmc_fork_tag); 5804 EVENTHANDLER_DEREGISTER(process_exit, pmc_exit_tag); 5805 EVENTHANDLER_DEREGISTER(kld_load, pmc_kld_load_tag); 5806 EVENTHANDLER_DEREGISTER(kld_unload, pmc_kld_unload_tag); 5807 5808 /* send SIGBUS to all owner threads, free up allocations */ 5809 if (pmc_ownerhash) 5810 for (ph = pmc_ownerhash; 5811 ph <= &pmc_ownerhash[pmc_ownerhashmask]; 5812 ph++) { 5813 LIST_FOREACH_SAFE(po, ph, po_next, tmp) { 5814 pmc_remove_owner(po); 5815 5816 /* send SIGBUS to owner processes */ 5817 PMCDBG3(MOD,INI,2, "cleanup signal proc=%p " 5818 "(%d, %s)", po->po_owner, 5819 po->po_owner->p_pid, 5820 po->po_owner->p_comm); 5821 5822 PROC_LOCK(po->po_owner); 5823 kern_psignal(po->po_owner, SIGBUS); 5824 PROC_UNLOCK(po->po_owner); 5825 5826 pmc_destroy_owner_descriptor(po); 5827 } 5828 } 5829 5830 /* reclaim allocated data structures */ 5831 taskqueue_drain(taskqueue_fast, &free_task); 5832 mtx_destroy(&pmc_threadfreelist_mtx); 5833 pmc_thread_descriptor_pool_drain(); 5834 5835 if (pmc_mtxpool) 5836 mtx_pool_destroy(&pmc_mtxpool); 5837 5838 mtx_destroy(&pmc_processhash_mtx); 5839 if (pmc_processhash) { 5840 #ifdef HWPMC_DEBUG 5841 struct pmc_process *pp; 5842 5843 PMCDBG0(MOD,INI,3, "destroy process hash"); 5844 for (prh = pmc_processhash; 5845 prh <= &pmc_processhash[pmc_processhashmask]; 5846 prh++) 5847 LIST_FOREACH(pp, prh, pp_next) 5848 PMCDBG1(MOD,INI,3, "pid=%d", pp->pp_proc->p_pid); 5849 #endif 5850 5851 hashdestroy(pmc_processhash, M_PMC, pmc_processhashmask); 5852 pmc_processhash = NULL; 5853 } 5854 5855 if (pmc_ownerhash) { 5856 PMCDBG0(MOD,INI,3, "destroy owner hash"); 5857 hashdestroy(pmc_ownerhash, M_PMC, pmc_ownerhashmask); 5858 pmc_ownerhash = NULL; 5859 } 5860 5861 KASSERT(CK_LIST_EMPTY(&pmc_ss_owners), 5862 ("[pmc,%d] Global SS owner list not empty", __LINE__)); 5863 KASSERT(pmc_ss_count == 0, 5864 ("[pmc,%d] Global SS count not empty", __LINE__)); 5865 5866 /* do processor and pmc-class dependent cleanup */ 5867 maxcpu = pmc_cpu_max(); 5868 5869 PMCDBG0(MOD,INI,3, "md cleanup"); 5870 if (md) { 5871 pmc_save_cpu_binding(&pb); 5872 for (cpu = 0; cpu < maxcpu; cpu++) { 5873 PMCDBG2(MOD,INI,1,"pmc-cleanup cpu=%d pcs=%p", 5874 cpu, pmc_pcpu[cpu]); 5875 if (!pmc_cpu_is_active(cpu) || pmc_pcpu[cpu] == NULL) 5876 continue; 5877 pmc_select_cpu(cpu); 5878 for (c = 0; c < md->pmd_nclass; c++) 5879 if (md->pmd_classdep[c].pcd_num > 0) 5880 md->pmd_classdep[c].pcd_pcpu_fini(md, 5881 cpu); 5882 if (md->pmd_pcpu_fini) 5883 md->pmd_pcpu_fini(md, cpu); 5884 } 5885 5886 if (md->pmd_cputype == PMC_CPU_GENERIC) 5887 pmc_generic_cpu_finalize(md); 5888 else 5889 pmc_md_finalize(md); 5890 5891 pmc_mdep_free(md); 5892 md = NULL; 5893 pmc_restore_cpu_binding(&pb); 5894 } 5895 5896 /* Free per-cpu descriptors. */ 5897 for (cpu = 0; cpu < maxcpu; cpu++) { 5898 if (!pmc_cpu_is_active(cpu)) 5899 continue; 5900 KASSERT(pmc_pcpu[cpu]->pc_sb[PMC_HR] != NULL, 5901 ("[pmc,%d] Null hw cpu sample buffer cpu=%d", __LINE__, 5902 cpu)); 5903 KASSERT(pmc_pcpu[cpu]->pc_sb[PMC_SR] != NULL, 5904 ("[pmc,%d] Null sw cpu sample buffer cpu=%d", __LINE__, 5905 cpu)); 5906 KASSERT(pmc_pcpu[cpu]->pc_sb[PMC_UR] != NULL, 5907 ("[pmc,%d] Null userret cpu sample buffer cpu=%d", __LINE__, 5908 cpu)); 5909 free(pmc_pcpu[cpu]->pc_sb[PMC_HR]->ps_callchains, M_PMC); 5910 free(pmc_pcpu[cpu]->pc_sb[PMC_HR], M_PMC); 5911 free(pmc_pcpu[cpu]->pc_sb[PMC_SR]->ps_callchains, M_PMC); 5912 free(pmc_pcpu[cpu]->pc_sb[PMC_SR], M_PMC); 5913 free(pmc_pcpu[cpu]->pc_sb[PMC_UR]->ps_callchains, M_PMC); 5914 free(pmc_pcpu[cpu]->pc_sb[PMC_UR], M_PMC); 5915 free(pmc_pcpu[cpu], M_PMC); 5916 } 5917 5918 free(pmc_pcpu, M_PMC); 5919 pmc_pcpu = NULL; 5920 5921 free(pmc_pcpu_saved, M_PMC); 5922 pmc_pcpu_saved = NULL; 5923 5924 if (pmc_pmcdisp) { 5925 free(pmc_pmcdisp, M_PMC); 5926 pmc_pmcdisp = NULL; 5927 } 5928 5929 if (pmc_rowindex_to_classdep) { 5930 free(pmc_rowindex_to_classdep, M_PMC); 5931 pmc_rowindex_to_classdep = NULL; 5932 } 5933 5934 pmclog_shutdown(); 5935 counter_u64_free(pmc_stats.pm_intr_ignored); 5936 counter_u64_free(pmc_stats.pm_intr_processed); 5937 counter_u64_free(pmc_stats.pm_intr_bufferfull); 5938 counter_u64_free(pmc_stats.pm_syscalls); 5939 counter_u64_free(pmc_stats.pm_syscall_errors); 5940 counter_u64_free(pmc_stats.pm_buffer_requests); 5941 counter_u64_free(pmc_stats.pm_buffer_requests_failed); 5942 counter_u64_free(pmc_stats.pm_log_sweeps); 5943 counter_u64_free(pmc_stats.pm_merges); 5944 counter_u64_free(pmc_stats.pm_overwrites); 5945 sx_xunlock(&pmc_sx); /* we are done */ 5946 } 5947 5948 /* 5949 * The function called at load/unload. 5950 */ 5951 5952 static int 5953 load (struct module *module __unused, int cmd, void *arg __unused) 5954 { 5955 int error; 5956 5957 error = 0; 5958 5959 switch (cmd) { 5960 case MOD_LOAD : 5961 /* initialize the subsystem */ 5962 error = pmc_initialize(); 5963 if (error != 0) 5964 break; 5965 PMCDBG2(MOD,INI,1, "syscall=%d maxcpu=%d", 5966 pmc_syscall_num, pmc_cpu_max()); 5967 break; 5968 5969 5970 case MOD_UNLOAD : 5971 case MOD_SHUTDOWN: 5972 pmc_cleanup(); 5973 PMCDBG0(MOD,INI,1, "unloaded"); 5974 break; 5975 5976 default : 5977 error = EINVAL; /* XXX should panic(9) */ 5978 break; 5979 } 5980 5981 return error; 5982 } 5983