1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2003-2008 Joseph Koshy 5 * Copyright (c) 2007 The FreeBSD Foundation 6 * Copyright (c) 2018 Matthew Macy 7 * All rights reserved. 8 * 9 * Portions of this software were developed by A. Joseph Koshy under 10 * sponsorship from the FreeBSD Foundation and Google, Inc. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 */ 34 35 #include <sys/cdefs.h> 36 __FBSDID("$FreeBSD$"); 37 38 #include <sys/param.h> 39 #include <sys/eventhandler.h> 40 #include <sys/gtaskqueue.h> 41 #include <sys/jail.h> 42 #include <sys/kernel.h> 43 #include <sys/kthread.h> 44 #include <sys/limits.h> 45 #include <sys/lock.h> 46 #include <sys/malloc.h> 47 #include <sys/module.h> 48 #include <sys/mount.h> 49 #include <sys/mutex.h> 50 #include <sys/pmc.h> 51 #include <sys/pmckern.h> 52 #include <sys/pmclog.h> 53 #include <sys/priv.h> 54 #include <sys/proc.h> 55 #include <sys/queue.h> 56 #include <sys/resourcevar.h> 57 #include <sys/rwlock.h> 58 #include <sys/sched.h> 59 #include <sys/signalvar.h> 60 #include <sys/smp.h> 61 #include <sys/sx.h> 62 #include <sys/sysctl.h> 63 #include <sys/sysent.h> 64 #include <sys/systm.h> 65 #include <sys/vnode.h> 66 67 #include <sys/linker.h> /* needs to be after <sys/malloc.h> */ 68 69 #include <machine/atomic.h> 70 #include <machine/md_var.h> 71 72 #include <vm/vm.h> 73 #include <vm/vm_extern.h> 74 #include <vm/pmap.h> 75 #include <vm/vm_map.h> 76 #include <vm/vm_object.h> 77 78 #include "hwpmc_soft.h" 79 80 #ifdef NUMA 81 #define NDOMAINS vm_ndomains 82 #else 83 #define NDOMAINS 1 84 #define malloc_domain(size, type, domain, flags) malloc((size), (type), (flags)) 85 #define free_domain(addr, type) free(addr, type) 86 #endif 87 88 /* 89 * Types 90 */ 91 92 enum pmc_flags { 93 PMC_FLAG_NONE = 0x00, /* do nothing */ 94 PMC_FLAG_REMOVE = 0x01, /* atomically remove entry from hash */ 95 PMC_FLAG_ALLOCATE = 0x02, /* add entry to hash if not found */ 96 PMC_FLAG_NOWAIT = 0x04, /* do not wait for mallocs */ 97 }; 98 99 /* 100 * The offset in sysent where the syscall is allocated. 101 */ 102 103 static int pmc_syscall_num = NO_SYSCALL; 104 struct pmc_cpu **pmc_pcpu; /* per-cpu state */ 105 pmc_value_t *pmc_pcpu_saved; /* saved PMC values: CSW handling */ 106 107 #define PMC_PCPU_SAVED(C,R) pmc_pcpu_saved[(R) + md->pmd_npmc*(C)] 108 109 struct mtx_pool *pmc_mtxpool; 110 static int *pmc_pmcdisp; /* PMC row dispositions */ 111 112 #define PMC_ROW_DISP_IS_FREE(R) (pmc_pmcdisp[(R)] == 0) 113 #define PMC_ROW_DISP_IS_THREAD(R) (pmc_pmcdisp[(R)] > 0) 114 #define PMC_ROW_DISP_IS_STANDALONE(R) (pmc_pmcdisp[(R)] < 0) 115 116 #define PMC_MARK_ROW_FREE(R) do { \ 117 pmc_pmcdisp[(R)] = 0; \ 118 } while (0) 119 120 #define PMC_MARK_ROW_STANDALONE(R) do { \ 121 KASSERT(pmc_pmcdisp[(R)] <= 0, ("[pmc,%d] row disposition error", \ 122 __LINE__)); \ 123 atomic_add_int(&pmc_pmcdisp[(R)], -1); \ 124 KASSERT(pmc_pmcdisp[(R)] >= (-pmc_cpu_max_active()), \ 125 ("[pmc,%d] row disposition error", __LINE__)); \ 126 } while (0) 127 128 #define PMC_UNMARK_ROW_STANDALONE(R) do { \ 129 atomic_add_int(&pmc_pmcdisp[(R)], 1); \ 130 KASSERT(pmc_pmcdisp[(R)] <= 0, ("[pmc,%d] row disposition error", \ 131 __LINE__)); \ 132 } while (0) 133 134 #define PMC_MARK_ROW_THREAD(R) do { \ 135 KASSERT(pmc_pmcdisp[(R)] >= 0, ("[pmc,%d] row disposition error", \ 136 __LINE__)); \ 137 atomic_add_int(&pmc_pmcdisp[(R)], 1); \ 138 } while (0) 139 140 #define PMC_UNMARK_ROW_THREAD(R) do { \ 141 atomic_add_int(&pmc_pmcdisp[(R)], -1); \ 142 KASSERT(pmc_pmcdisp[(R)] >= 0, ("[pmc,%d] row disposition error", \ 143 __LINE__)); \ 144 } while (0) 145 146 147 /* various event handlers */ 148 static eventhandler_tag pmc_exit_tag, pmc_fork_tag, pmc_kld_load_tag, 149 pmc_kld_unload_tag; 150 151 /* Module statistics */ 152 struct pmc_driverstats pmc_stats; 153 154 155 /* Machine/processor dependent operations */ 156 static struct pmc_mdep *md; 157 158 /* 159 * Hash tables mapping owner processes and target threads to PMCs. 160 */ 161 162 struct mtx pmc_processhash_mtx; /* spin mutex */ 163 static u_long pmc_processhashmask; 164 static LIST_HEAD(pmc_processhash, pmc_process) *pmc_processhash; 165 166 /* 167 * Hash table of PMC owner descriptors. This table is protected by 168 * the shared PMC "sx" lock. 169 */ 170 171 static u_long pmc_ownerhashmask; 172 static LIST_HEAD(pmc_ownerhash, pmc_owner) *pmc_ownerhash; 173 174 /* 175 * List of PMC owners with system-wide sampling PMCs. 176 */ 177 178 static CK_LIST_HEAD(, pmc_owner) pmc_ss_owners; 179 180 /* 181 * List of free thread entries. This is protected by the spin 182 * mutex. 183 */ 184 static struct mtx pmc_threadfreelist_mtx; /* spin mutex */ 185 static LIST_HEAD(, pmc_thread) pmc_threadfreelist; 186 static int pmc_threadfreelist_entries=0; 187 #define THREADENTRY_SIZE \ 188 (sizeof(struct pmc_thread) + (md->pmd_npmc * sizeof(struct pmc_threadpmcstate))) 189 190 /* 191 * Task to free thread descriptors 192 */ 193 static struct grouptask free_gtask; 194 195 /* 196 * A map of row indices to classdep structures. 197 */ 198 static struct pmc_classdep **pmc_rowindex_to_classdep; 199 200 /* 201 * Prototypes 202 */ 203 204 #ifdef HWPMC_DEBUG 205 static int pmc_debugflags_sysctl_handler(SYSCTL_HANDLER_ARGS); 206 static int pmc_debugflags_parse(char *newstr, char *fence); 207 #endif 208 209 static int load(struct module *module, int cmd, void *arg); 210 static void pmc_add_thread_descriptors_from_proc(struct proc *p, 211 struct pmc_process *pp); 212 static int pmc_attach_process(struct proc *p, struct pmc *pm); 213 static struct pmc *pmc_allocate_pmc_descriptor(void); 214 static struct pmc_owner *pmc_allocate_owner_descriptor(struct proc *p); 215 static int pmc_attach_one_process(struct proc *p, struct pmc *pm); 216 static int pmc_can_allocate_rowindex(struct proc *p, unsigned int ri, 217 int cpu); 218 static int pmc_can_attach(struct pmc *pm, struct proc *p); 219 static void pmc_capture_user_callchain(int cpu, int soft, struct trapframe *tf); 220 static void pmc_cleanup(void); 221 static int pmc_detach_process(struct proc *p, struct pmc *pm); 222 static int pmc_detach_one_process(struct proc *p, struct pmc *pm, 223 int flags); 224 static void pmc_destroy_owner_descriptor(struct pmc_owner *po); 225 static void pmc_destroy_pmc_descriptor(struct pmc *pm); 226 static void pmc_destroy_process_descriptor(struct pmc_process *pp); 227 static struct pmc_owner *pmc_find_owner_descriptor(struct proc *p); 228 static int pmc_find_pmc(pmc_id_t pmcid, struct pmc **pm); 229 static struct pmc *pmc_find_pmc_descriptor_in_process(struct pmc_owner *po, 230 pmc_id_t pmc); 231 static struct pmc_process *pmc_find_process_descriptor(struct proc *p, 232 uint32_t mode); 233 static struct pmc_thread *pmc_find_thread_descriptor(struct pmc_process *pp, 234 struct thread *td, uint32_t mode); 235 static void pmc_force_context_switch(void); 236 static void pmc_link_target_process(struct pmc *pm, 237 struct pmc_process *pp); 238 static void pmc_log_all_process_mappings(struct pmc_owner *po); 239 static void pmc_log_kernel_mappings(struct pmc *pm); 240 static void pmc_log_process_mappings(struct pmc_owner *po, struct proc *p); 241 static void pmc_maybe_remove_owner(struct pmc_owner *po); 242 static void pmc_process_csw_in(struct thread *td); 243 static void pmc_process_csw_out(struct thread *td); 244 static void pmc_process_exit(void *arg, struct proc *p); 245 static void pmc_process_fork(void *arg, struct proc *p1, 246 struct proc *p2, int n); 247 static void pmc_process_samples(int cpu, int soft); 248 static void pmc_release_pmc_descriptor(struct pmc *pmc); 249 static void pmc_process_thread_add(struct thread *td); 250 static void pmc_process_thread_delete(struct thread *td); 251 static void pmc_remove_owner(struct pmc_owner *po); 252 static void pmc_remove_process_descriptor(struct pmc_process *pp); 253 static void pmc_restore_cpu_binding(struct pmc_binding *pb); 254 static void pmc_save_cpu_binding(struct pmc_binding *pb); 255 static void pmc_select_cpu(int cpu); 256 static int pmc_start(struct pmc *pm); 257 static int pmc_stop(struct pmc *pm); 258 static int pmc_syscall_handler(struct thread *td, void *syscall_args); 259 static struct pmc_thread *pmc_thread_descriptor_pool_alloc(void); 260 static void pmc_thread_descriptor_pool_drain(void); 261 static void pmc_thread_descriptor_pool_free(struct pmc_thread *pt); 262 static void pmc_unlink_target_process(struct pmc *pmc, 263 struct pmc_process *pp); 264 static int generic_switch_in(struct pmc_cpu *pc, struct pmc_process *pp); 265 static int generic_switch_out(struct pmc_cpu *pc, struct pmc_process *pp); 266 static struct pmc_mdep *pmc_generic_cpu_initialize(void); 267 static void pmc_generic_cpu_finalize(struct pmc_mdep *md); 268 269 /* 270 * Kernel tunables and sysctl(8) interface. 271 */ 272 273 SYSCTL_DECL(_kern_hwpmc); 274 SYSCTL_NODE(_kern_hwpmc, OID_AUTO, stats, CTLFLAG_RW, 0, "HWPMC stats"); 275 276 277 /* Stats. */ 278 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, intr_ignored, CTLFLAG_RW, 279 &pmc_stats.pm_intr_ignored, "# of interrupts ignored"); 280 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, intr_processed, CTLFLAG_RW, 281 &pmc_stats.pm_intr_processed, "# of interrupts processed"); 282 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, intr_bufferfull, CTLFLAG_RW, 283 &pmc_stats.pm_intr_bufferfull, "# of interrupts where buffer was full"); 284 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, syscalls, CTLFLAG_RW, 285 &pmc_stats.pm_syscalls, "# of syscalls"); 286 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, syscall_errors, CTLFLAG_RW, 287 &pmc_stats.pm_syscall_errors, "# of syscall_errors"); 288 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, buffer_requests, CTLFLAG_RW, 289 &pmc_stats.pm_buffer_requests, "# of buffer requests"); 290 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, buffer_requests_failed, CTLFLAG_RW, 291 &pmc_stats.pm_buffer_requests_failed, "# of buffer requests which failed"); 292 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, log_sweeps, CTLFLAG_RW, 293 &pmc_stats.pm_log_sweeps, "# of ?"); 294 295 static int pmc_callchaindepth = PMC_CALLCHAIN_DEPTH; 296 SYSCTL_INT(_kern_hwpmc, OID_AUTO, callchaindepth, CTLFLAG_RDTUN, 297 &pmc_callchaindepth, 0, "depth of call chain records"); 298 299 char pmc_cpuid[64]; 300 SYSCTL_STRING(_kern_hwpmc, OID_AUTO, cpuid, CTLFLAG_RD, 301 pmc_cpuid, 0, "cpu version string"); 302 #ifdef HWPMC_DEBUG 303 struct pmc_debugflags pmc_debugflags = PMC_DEBUG_DEFAULT_FLAGS; 304 char pmc_debugstr[PMC_DEBUG_STRSIZE]; 305 TUNABLE_STR(PMC_SYSCTL_NAME_PREFIX "debugflags", pmc_debugstr, 306 sizeof(pmc_debugstr)); 307 SYSCTL_PROC(_kern_hwpmc, OID_AUTO, debugflags, 308 CTLTYPE_STRING | CTLFLAG_RWTUN | CTLFLAG_NOFETCH, 309 0, 0, pmc_debugflags_sysctl_handler, "A", "debug flags"); 310 #endif 311 312 313 /* 314 * kern.hwpmc.hashrows -- determines the number of rows in the 315 * of the hash table used to look up threads 316 */ 317 318 static int pmc_hashsize = PMC_HASH_SIZE; 319 SYSCTL_INT(_kern_hwpmc, OID_AUTO, hashsize, CTLFLAG_RDTUN, 320 &pmc_hashsize, 0, "rows in hash tables"); 321 322 /* 323 * kern.hwpmc.nsamples --- number of PC samples/callchain stacks per CPU 324 */ 325 326 static int pmc_nsamples = PMC_NSAMPLES; 327 SYSCTL_INT(_kern_hwpmc, OID_AUTO, nsamples, CTLFLAG_RDTUN, 328 &pmc_nsamples, 0, "number of PC samples per CPU"); 329 330 331 /* 332 * kern.hwpmc.mtxpoolsize -- number of mutexes in the mutex pool. 333 */ 334 335 static int pmc_mtxpool_size = PMC_MTXPOOL_SIZE; 336 SYSCTL_INT(_kern_hwpmc, OID_AUTO, mtxpoolsize, CTLFLAG_RDTUN, 337 &pmc_mtxpool_size, 0, "size of spin mutex pool"); 338 339 340 /* 341 * kern.hwpmc.threadfreelist_entries -- number of free entries 342 */ 343 344 SYSCTL_INT(_kern_hwpmc, OID_AUTO, threadfreelist_entries, CTLFLAG_RD, 345 &pmc_threadfreelist_entries, 0, "number of avalable thread entries"); 346 347 348 /* 349 * kern.hwpmc.threadfreelist_max -- maximum number of free entries 350 */ 351 352 static int pmc_threadfreelist_max = PMC_THREADLIST_MAX; 353 SYSCTL_INT(_kern_hwpmc, OID_AUTO, threadfreelist_max, CTLFLAG_RW, 354 &pmc_threadfreelist_max, 0, 355 "maximum number of available thread entries before freeing some"); 356 357 358 /* 359 * security.bsd.unprivileged_syspmcs -- allow non-root processes to 360 * allocate system-wide PMCs. 361 * 362 * Allowing unprivileged processes to allocate system PMCs is convenient 363 * if system-wide measurements need to be taken concurrently with other 364 * per-process measurements. This feature is turned off by default. 365 */ 366 367 static int pmc_unprivileged_syspmcs = 0; 368 SYSCTL_INT(_security_bsd, OID_AUTO, unprivileged_syspmcs, CTLFLAG_RWTUN, 369 &pmc_unprivileged_syspmcs, 0, 370 "allow unprivileged process to allocate system PMCs"); 371 372 /* 373 * Hash function. Discard the lower 2 bits of the pointer since 374 * these are always zero for our uses. The hash multiplier is 375 * round((2^LONG_BIT) * ((sqrt(5)-1)/2)). 376 */ 377 378 #if LONG_BIT == 64 379 #define _PMC_HM 11400714819323198486u 380 #elif LONG_BIT == 32 381 #define _PMC_HM 2654435769u 382 #else 383 #error Must know the size of 'long' to compile 384 #endif 385 386 #define PMC_HASH_PTR(P,M) ((((unsigned long) (P) >> 2) * _PMC_HM) & (M)) 387 388 /* 389 * Syscall structures 390 */ 391 392 /* The `sysent' for the new syscall */ 393 static struct sysent pmc_sysent = { 394 .sy_narg = 2, 395 .sy_call = pmc_syscall_handler, 396 }; 397 398 static struct syscall_module_data pmc_syscall_mod = { 399 .chainevh = load, 400 .chainarg = NULL, 401 .offset = &pmc_syscall_num, 402 .new_sysent = &pmc_sysent, 403 .old_sysent = { .sy_narg = 0, .sy_call = NULL }, 404 .flags = SY_THR_STATIC_KLD, 405 }; 406 407 static moduledata_t pmc_mod = { 408 .name = PMC_MODULE_NAME, 409 .evhand = syscall_module_handler, 410 .priv = &pmc_syscall_mod, 411 }; 412 413 #ifdef EARLY_AP_STARTUP 414 DECLARE_MODULE(pmc, pmc_mod, SI_SUB_SYSCALLS, SI_ORDER_ANY); 415 #else 416 DECLARE_MODULE(pmc, pmc_mod, SI_SUB_SMP, SI_ORDER_ANY); 417 #endif 418 MODULE_VERSION(pmc, PMC_VERSION); 419 420 #ifdef HWPMC_DEBUG 421 enum pmc_dbgparse_state { 422 PMCDS_WS, /* in whitespace */ 423 PMCDS_MAJOR, /* seen a major keyword */ 424 PMCDS_MINOR 425 }; 426 427 static int 428 pmc_debugflags_parse(char *newstr, char *fence) 429 { 430 char c, *p, *q; 431 struct pmc_debugflags *tmpflags; 432 int error, found, *newbits, tmp; 433 size_t kwlen; 434 435 tmpflags = malloc(sizeof(*tmpflags), M_PMC, M_WAITOK|M_ZERO); 436 437 p = newstr; 438 error = 0; 439 440 for (; p < fence && (c = *p); p++) { 441 442 /* skip white space */ 443 if (c == ' ' || c == '\t') 444 continue; 445 446 /* look for a keyword followed by "=" */ 447 for (q = p; p < fence && (c = *p) && c != '='; p++) 448 ; 449 if (c != '=') { 450 error = EINVAL; 451 goto done; 452 } 453 454 kwlen = p - q; 455 newbits = NULL; 456 457 /* lookup flag group name */ 458 #define DBG_SET_FLAG_MAJ(S,F) \ 459 if (kwlen == sizeof(S)-1 && strncmp(q, S, kwlen) == 0) \ 460 newbits = &tmpflags->pdb_ ## F; 461 462 DBG_SET_FLAG_MAJ("cpu", CPU); 463 DBG_SET_FLAG_MAJ("csw", CSW); 464 DBG_SET_FLAG_MAJ("logging", LOG); 465 DBG_SET_FLAG_MAJ("module", MOD); 466 DBG_SET_FLAG_MAJ("md", MDP); 467 DBG_SET_FLAG_MAJ("owner", OWN); 468 DBG_SET_FLAG_MAJ("pmc", PMC); 469 DBG_SET_FLAG_MAJ("process", PRC); 470 DBG_SET_FLAG_MAJ("sampling", SAM); 471 472 if (newbits == NULL) { 473 error = EINVAL; 474 goto done; 475 } 476 477 p++; /* skip the '=' */ 478 479 /* Now parse the individual flags */ 480 tmp = 0; 481 newflag: 482 for (q = p; p < fence && (c = *p); p++) 483 if (c == ' ' || c == '\t' || c == ',') 484 break; 485 486 /* p == fence or c == ws or c == "," or c == 0 */ 487 488 if ((kwlen = p - q) == 0) { 489 *newbits = tmp; 490 continue; 491 } 492 493 found = 0; 494 #define DBG_SET_FLAG_MIN(S,F) \ 495 if (kwlen == sizeof(S)-1 && strncmp(q, S, kwlen) == 0) \ 496 tmp |= found = (1 << PMC_DEBUG_MIN_ ## F) 497 498 /* a '*' denotes all possible flags in the group */ 499 if (kwlen == 1 && *q == '*') 500 tmp = found = ~0; 501 /* look for individual flag names */ 502 DBG_SET_FLAG_MIN("allocaterow", ALR); 503 DBG_SET_FLAG_MIN("allocate", ALL); 504 DBG_SET_FLAG_MIN("attach", ATT); 505 DBG_SET_FLAG_MIN("bind", BND); 506 DBG_SET_FLAG_MIN("config", CFG); 507 DBG_SET_FLAG_MIN("exec", EXC); 508 DBG_SET_FLAG_MIN("exit", EXT); 509 DBG_SET_FLAG_MIN("find", FND); 510 DBG_SET_FLAG_MIN("flush", FLS); 511 DBG_SET_FLAG_MIN("fork", FRK); 512 DBG_SET_FLAG_MIN("getbuf", GTB); 513 DBG_SET_FLAG_MIN("hook", PMH); 514 DBG_SET_FLAG_MIN("init", INI); 515 DBG_SET_FLAG_MIN("intr", INT); 516 DBG_SET_FLAG_MIN("linktarget", TLK); 517 DBG_SET_FLAG_MIN("mayberemove", OMR); 518 DBG_SET_FLAG_MIN("ops", OPS); 519 DBG_SET_FLAG_MIN("read", REA); 520 DBG_SET_FLAG_MIN("register", REG); 521 DBG_SET_FLAG_MIN("release", REL); 522 DBG_SET_FLAG_MIN("remove", ORM); 523 DBG_SET_FLAG_MIN("sample", SAM); 524 DBG_SET_FLAG_MIN("scheduleio", SIO); 525 DBG_SET_FLAG_MIN("select", SEL); 526 DBG_SET_FLAG_MIN("signal", SIG); 527 DBG_SET_FLAG_MIN("swi", SWI); 528 DBG_SET_FLAG_MIN("swo", SWO); 529 DBG_SET_FLAG_MIN("start", STA); 530 DBG_SET_FLAG_MIN("stop", STO); 531 DBG_SET_FLAG_MIN("syscall", PMS); 532 DBG_SET_FLAG_MIN("unlinktarget", TUL); 533 DBG_SET_FLAG_MIN("write", WRI); 534 if (found == 0) { 535 /* unrecognized flag name */ 536 error = EINVAL; 537 goto done; 538 } 539 540 if (c == 0 || c == ' ' || c == '\t') { /* end of flag group */ 541 *newbits = tmp; 542 continue; 543 } 544 545 p++; 546 goto newflag; 547 } 548 549 /* save the new flag set */ 550 bcopy(tmpflags, &pmc_debugflags, sizeof(pmc_debugflags)); 551 552 done: 553 free(tmpflags, M_PMC); 554 return error; 555 } 556 557 static int 558 pmc_debugflags_sysctl_handler(SYSCTL_HANDLER_ARGS) 559 { 560 char *fence, *newstr; 561 int error; 562 unsigned int n; 563 564 (void) arg1; (void) arg2; /* unused parameters */ 565 566 n = sizeof(pmc_debugstr); 567 newstr = malloc(n, M_PMC, M_WAITOK|M_ZERO); 568 (void) strlcpy(newstr, pmc_debugstr, n); 569 570 error = sysctl_handle_string(oidp, newstr, n, req); 571 572 /* if there is a new string, parse and copy it */ 573 if (error == 0 && req->newptr != NULL) { 574 fence = newstr + (n < req->newlen ? n : req->newlen + 1); 575 if ((error = pmc_debugflags_parse(newstr, fence)) == 0) 576 (void) strlcpy(pmc_debugstr, newstr, 577 sizeof(pmc_debugstr)); 578 } 579 580 free(newstr, M_PMC); 581 582 return error; 583 } 584 #endif 585 586 /* 587 * Map a row index to a classdep structure and return the adjusted row 588 * index for the PMC class index. 589 */ 590 static struct pmc_classdep * 591 pmc_ri_to_classdep(struct pmc_mdep *md, int ri, int *adjri) 592 { 593 struct pmc_classdep *pcd; 594 595 (void) md; 596 597 KASSERT(ri >= 0 && ri < md->pmd_npmc, 598 ("[pmc,%d] illegal row-index %d", __LINE__, ri)); 599 600 pcd = pmc_rowindex_to_classdep[ri]; 601 602 KASSERT(pcd != NULL, 603 ("[pmc,%d] ri %d null pcd", __LINE__, ri)); 604 605 *adjri = ri - pcd->pcd_ri; 606 607 KASSERT(*adjri >= 0 && *adjri < pcd->pcd_num, 608 ("[pmc,%d] adjusted row-index %d", __LINE__, *adjri)); 609 610 return (pcd); 611 } 612 613 /* 614 * Concurrency Control 615 * 616 * The driver manages the following data structures: 617 * 618 * - target process descriptors, one per target process 619 * - owner process descriptors (and attached lists), one per owner process 620 * - lookup hash tables for owner and target processes 621 * - PMC descriptors (and attached lists) 622 * - per-cpu hardware state 623 * - the 'hook' variable through which the kernel calls into 624 * this module 625 * - the machine hardware state (managed by the MD layer) 626 * 627 * These data structures are accessed from: 628 * 629 * - thread context-switch code 630 * - interrupt handlers (possibly on multiple cpus) 631 * - kernel threads on multiple cpus running on behalf of user 632 * processes doing system calls 633 * - this driver's private kernel threads 634 * 635 * = Locks and Locking strategy = 636 * 637 * The driver uses four locking strategies for its operation: 638 * 639 * - The global SX lock "pmc_sx" is used to protect internal 640 * data structures. 641 * 642 * Calls into the module by syscall() start with this lock being 643 * held in exclusive mode. Depending on the requested operation, 644 * the lock may be downgraded to 'shared' mode to allow more 645 * concurrent readers into the module. Calls into the module from 646 * other parts of the kernel acquire the lock in shared mode. 647 * 648 * This SX lock is held in exclusive mode for any operations that 649 * modify the linkages between the driver's internal data structures. 650 * 651 * The 'pmc_hook' function pointer is also protected by this lock. 652 * It is only examined with the sx lock held in exclusive mode. The 653 * kernel module is allowed to be unloaded only with the sx lock held 654 * in exclusive mode. In normal syscall handling, after acquiring the 655 * pmc_sx lock we first check that 'pmc_hook' is non-null before 656 * proceeding. This prevents races between the thread unloading the module 657 * and other threads seeking to use the module. 658 * 659 * - Lookups of target process structures and owner process structures 660 * cannot use the global "pmc_sx" SX lock because these lookups need 661 * to happen during context switches and in other critical sections 662 * where sleeping is not allowed. We protect these lookup tables 663 * with their own private spin-mutexes, "pmc_processhash_mtx" and 664 * "pmc_ownerhash_mtx". 665 * 666 * - Interrupt handlers work in a lock free manner. At interrupt 667 * time, handlers look at the PMC pointer (phw->phw_pmc) configured 668 * when the PMC was started. If this pointer is NULL, the interrupt 669 * is ignored after updating driver statistics. We ensure that this 670 * pointer is set (using an atomic operation if necessary) before the 671 * PMC hardware is started. Conversely, this pointer is unset atomically 672 * only after the PMC hardware is stopped. 673 * 674 * We ensure that everything needed for the operation of an 675 * interrupt handler is available without it needing to acquire any 676 * locks. We also ensure that a PMC's software state is destroyed only 677 * after the PMC is taken off hardware (on all CPUs). 678 * 679 * - Context-switch handling with process-private PMCs needs more 680 * care. 681 * 682 * A given process may be the target of multiple PMCs. For example, 683 * PMCATTACH and PMCDETACH may be requested by a process on one CPU 684 * while the target process is running on another. A PMC could also 685 * be getting released because its owner is exiting. We tackle 686 * these situations in the following manner: 687 * 688 * - each target process structure 'pmc_process' has an array 689 * of 'struct pmc *' pointers, one for each hardware PMC. 690 * 691 * - At context switch IN time, each "target" PMC in RUNNING state 692 * gets started on hardware and a pointer to each PMC is copied into 693 * the per-cpu phw array. The 'runcount' for the PMC is 694 * incremented. 695 * 696 * - At context switch OUT time, all process-virtual PMCs are stopped 697 * on hardware. The saved value is added to the PMCs value field 698 * only if the PMC is in a non-deleted state (the PMCs state could 699 * have changed during the current time slice). 700 * 701 * Note that since in-between a switch IN on a processor and a switch 702 * OUT, the PMC could have been released on another CPU. Therefore 703 * context switch OUT always looks at the hardware state to turn 704 * OFF PMCs and will update a PMC's saved value only if reachable 705 * from the target process record. 706 * 707 * - OP PMCRELEASE could be called on a PMC at any time (the PMC could 708 * be attached to many processes at the time of the call and could 709 * be active on multiple CPUs). 710 * 711 * We prevent further scheduling of the PMC by marking it as in 712 * state 'DELETED'. If the runcount of the PMC is non-zero then 713 * this PMC is currently running on a CPU somewhere. The thread 714 * doing the PMCRELEASE operation waits by repeatedly doing a 715 * pause() till the runcount comes to zero. 716 * 717 * The contents of a PMC descriptor (struct pmc) are protected using 718 * a spin-mutex. In order to save space, we use a mutex pool. 719 * 720 * In terms of lock types used by witness(4), we use: 721 * - Type "pmc-sx", used by the global SX lock. 722 * - Type "pmc-sleep", for sleep mutexes used by logger threads. 723 * - Type "pmc-per-proc", for protecting PMC owner descriptors. 724 * - Type "pmc-leaf", used for all other spin mutexes. 725 */ 726 727 /* 728 * save the cpu binding of the current kthread 729 */ 730 731 static void 732 pmc_save_cpu_binding(struct pmc_binding *pb) 733 { 734 PMCDBG0(CPU,BND,2, "save-cpu"); 735 thread_lock(curthread); 736 pb->pb_bound = sched_is_bound(curthread); 737 pb->pb_cpu = curthread->td_oncpu; 738 thread_unlock(curthread); 739 PMCDBG1(CPU,BND,2, "save-cpu cpu=%d", pb->pb_cpu); 740 } 741 742 /* 743 * restore the cpu binding of the current thread 744 */ 745 746 static void 747 pmc_restore_cpu_binding(struct pmc_binding *pb) 748 { 749 PMCDBG2(CPU,BND,2, "restore-cpu curcpu=%d restore=%d", 750 curthread->td_oncpu, pb->pb_cpu); 751 thread_lock(curthread); 752 if (pb->pb_bound) 753 sched_bind(curthread, pb->pb_cpu); 754 else 755 sched_unbind(curthread); 756 thread_unlock(curthread); 757 PMCDBG0(CPU,BND,2, "restore-cpu done"); 758 } 759 760 /* 761 * move execution over the specified cpu and bind it there. 762 */ 763 764 static void 765 pmc_select_cpu(int cpu) 766 { 767 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 768 ("[pmc,%d] bad cpu number %d", __LINE__, cpu)); 769 770 /* Never move to an inactive CPU. */ 771 KASSERT(pmc_cpu_is_active(cpu), ("[pmc,%d] selecting inactive " 772 "CPU %d", __LINE__, cpu)); 773 774 PMCDBG1(CPU,SEL,2, "select-cpu cpu=%d", cpu); 775 thread_lock(curthread); 776 sched_bind(curthread, cpu); 777 thread_unlock(curthread); 778 779 KASSERT(curthread->td_oncpu == cpu, 780 ("[pmc,%d] CPU not bound [cpu=%d, curr=%d]", __LINE__, 781 cpu, curthread->td_oncpu)); 782 783 PMCDBG1(CPU,SEL,2, "select-cpu cpu=%d ok", cpu); 784 } 785 786 /* 787 * Force a context switch. 788 * 789 * We do this by pause'ing for 1 tick -- invoking mi_switch() is not 790 * guaranteed to force a context switch. 791 */ 792 793 static void 794 pmc_force_context_switch(void) 795 { 796 797 pause("pmcctx", 1); 798 } 799 800 /* 801 * Get the file name for an executable. This is a simple wrapper 802 * around vn_fullpath(9). 803 */ 804 805 static void 806 pmc_getfilename(struct vnode *v, char **fullpath, char **freepath) 807 { 808 809 *fullpath = "unknown"; 810 *freepath = NULL; 811 vn_fullpath(curthread, v, fullpath, freepath); 812 } 813 814 /* 815 * remove an process owning PMCs 816 */ 817 818 void 819 pmc_remove_owner(struct pmc_owner *po) 820 { 821 struct pmc *pm, *tmp; 822 823 sx_assert(&pmc_sx, SX_XLOCKED); 824 825 PMCDBG1(OWN,ORM,1, "remove-owner po=%p", po); 826 827 /* Remove descriptor from the owner hash table */ 828 LIST_REMOVE(po, po_next); 829 830 /* release all owned PMC descriptors */ 831 LIST_FOREACH_SAFE(pm, &po->po_pmcs, pm_next, tmp) { 832 PMCDBG1(OWN,ORM,2, "pmc=%p", pm); 833 KASSERT(pm->pm_owner == po, 834 ("[pmc,%d] owner %p != po %p", __LINE__, pm->pm_owner, po)); 835 836 pmc_release_pmc_descriptor(pm); /* will unlink from the list */ 837 pmc_destroy_pmc_descriptor(pm); 838 } 839 840 KASSERT(po->po_sscount == 0, 841 ("[pmc,%d] SS count not zero", __LINE__)); 842 KASSERT(LIST_EMPTY(&po->po_pmcs), 843 ("[pmc,%d] PMC list not empty", __LINE__)); 844 845 /* de-configure the log file if present */ 846 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 847 pmclog_deconfigure_log(po); 848 } 849 850 /* 851 * remove an owner process record if all conditions are met. 852 */ 853 854 static void 855 pmc_maybe_remove_owner(struct pmc_owner *po) 856 { 857 858 PMCDBG1(OWN,OMR,1, "maybe-remove-owner po=%p", po); 859 860 /* 861 * Remove owner record if 862 * - this process does not own any PMCs 863 * - this process has not allocated a system-wide sampling buffer 864 */ 865 866 if (LIST_EMPTY(&po->po_pmcs) && 867 ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0)) { 868 pmc_remove_owner(po); 869 pmc_destroy_owner_descriptor(po); 870 } 871 } 872 873 /* 874 * Add an association between a target process and a PMC. 875 */ 876 877 static void 878 pmc_link_target_process(struct pmc *pm, struct pmc_process *pp) 879 { 880 int ri; 881 struct pmc_target *pt; 882 #ifdef INVARIANTS 883 struct pmc_thread *pt_td; 884 #endif 885 886 sx_assert(&pmc_sx, SX_XLOCKED); 887 888 KASSERT(pm != NULL && pp != NULL, 889 ("[pmc,%d] Null pm %p or pp %p", __LINE__, pm, pp)); 890 KASSERT(PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)), 891 ("[pmc,%d] Attaching a non-process-virtual pmc=%p to pid=%d", 892 __LINE__, pm, pp->pp_proc->p_pid)); 893 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= ((int) md->pmd_npmc - 1), 894 ("[pmc,%d] Illegal reference count %d for process record %p", 895 __LINE__, pp->pp_refcnt, (void *) pp)); 896 897 ri = PMC_TO_ROWINDEX(pm); 898 899 PMCDBG3(PRC,TLK,1, "link-target pmc=%p ri=%d pmc-process=%p", 900 pm, ri, pp); 901 902 #ifdef HWPMC_DEBUG 903 LIST_FOREACH(pt, &pm->pm_targets, pt_next) 904 if (pt->pt_process == pp) 905 KASSERT(0, ("[pmc,%d] pp %p already in pmc %p targets", 906 __LINE__, pp, pm)); 907 #endif 908 909 pt = malloc(sizeof(struct pmc_target), M_PMC, M_WAITOK|M_ZERO); 910 pt->pt_process = pp; 911 912 LIST_INSERT_HEAD(&pm->pm_targets, pt, pt_next); 913 914 atomic_store_rel_ptr((uintptr_t *)&pp->pp_pmcs[ri].pp_pmc, 915 (uintptr_t)pm); 916 917 if (pm->pm_owner->po_owner == pp->pp_proc) 918 pm->pm_flags |= PMC_F_ATTACHED_TO_OWNER; 919 920 /* 921 * Initialize the per-process values at this row index. 922 */ 923 pp->pp_pmcs[ri].pp_pmcval = PMC_TO_MODE(pm) == PMC_MODE_TS ? 924 pm->pm_sc.pm_reloadcount : 0; 925 926 pp->pp_refcnt++; 927 928 #ifdef INVARIANTS 929 /* Confirm that the per-thread values at this row index are cleared. */ 930 if (PMC_TO_MODE(pm) == PMC_MODE_TS) { 931 mtx_lock_spin(pp->pp_tdslock); 932 LIST_FOREACH(pt_td, &pp->pp_tds, pt_next) { 933 KASSERT(pt_td->pt_pmcs[ri].pt_pmcval == (pmc_value_t) 0, 934 ("[pmc,%d] pt_pmcval not cleared for pid=%d at " 935 "ri=%d", __LINE__, pp->pp_proc->p_pid, ri)); 936 } 937 mtx_unlock_spin(pp->pp_tdslock); 938 } 939 #endif 940 } 941 942 /* 943 * Removes the association between a target process and a PMC. 944 */ 945 946 static void 947 pmc_unlink_target_process(struct pmc *pm, struct pmc_process *pp) 948 { 949 int ri; 950 struct proc *p; 951 struct pmc_target *ptgt; 952 struct pmc_thread *pt; 953 954 sx_assert(&pmc_sx, SX_XLOCKED); 955 956 KASSERT(pm != NULL && pp != NULL, 957 ("[pmc,%d] Null pm %p or pp %p", __LINE__, pm, pp)); 958 959 KASSERT(pp->pp_refcnt >= 1 && pp->pp_refcnt <= (int) md->pmd_npmc, 960 ("[pmc,%d] Illegal ref count %d on process record %p", 961 __LINE__, pp->pp_refcnt, (void *) pp)); 962 963 ri = PMC_TO_ROWINDEX(pm); 964 965 PMCDBG3(PRC,TUL,1, "unlink-target pmc=%p ri=%d pmc-process=%p", 966 pm, ri, pp); 967 968 KASSERT(pp->pp_pmcs[ri].pp_pmc == pm, 969 ("[pmc,%d] PMC ri %d mismatch pmc %p pp->[ri] %p", __LINE__, 970 ri, pm, pp->pp_pmcs[ri].pp_pmc)); 971 972 pp->pp_pmcs[ri].pp_pmc = NULL; 973 pp->pp_pmcs[ri].pp_pmcval = (pmc_value_t) 0; 974 975 /* Clear the per-thread values at this row index. */ 976 if (PMC_TO_MODE(pm) == PMC_MODE_TS) { 977 mtx_lock_spin(pp->pp_tdslock); 978 LIST_FOREACH(pt, &pp->pp_tds, pt_next) 979 pt->pt_pmcs[ri].pt_pmcval = (pmc_value_t) 0; 980 mtx_unlock_spin(pp->pp_tdslock); 981 } 982 983 /* Remove owner-specific flags */ 984 if (pm->pm_owner->po_owner == pp->pp_proc) { 985 pp->pp_flags &= ~PMC_PP_ENABLE_MSR_ACCESS; 986 pm->pm_flags &= ~PMC_F_ATTACHED_TO_OWNER; 987 } 988 989 pp->pp_refcnt--; 990 991 /* Remove the target process from the PMC structure */ 992 LIST_FOREACH(ptgt, &pm->pm_targets, pt_next) 993 if (ptgt->pt_process == pp) 994 break; 995 996 KASSERT(ptgt != NULL, ("[pmc,%d] process %p (pp: %p) not found " 997 "in pmc %p", __LINE__, pp->pp_proc, pp, pm)); 998 999 LIST_REMOVE(ptgt, pt_next); 1000 free(ptgt, M_PMC); 1001 1002 /* if the PMC now lacks targets, send the owner a SIGIO */ 1003 if (LIST_EMPTY(&pm->pm_targets)) { 1004 p = pm->pm_owner->po_owner; 1005 PROC_LOCK(p); 1006 kern_psignal(p, SIGIO); 1007 PROC_UNLOCK(p); 1008 1009 PMCDBG2(PRC,SIG,2, "signalling proc=%p signal=%d", p, 1010 SIGIO); 1011 } 1012 } 1013 1014 /* 1015 * Check if PMC 'pm' may be attached to target process 't'. 1016 */ 1017 1018 static int 1019 pmc_can_attach(struct pmc *pm, struct proc *t) 1020 { 1021 struct proc *o; /* pmc owner */ 1022 struct ucred *oc, *tc; /* owner, target credentials */ 1023 int decline_attach, i; 1024 1025 /* 1026 * A PMC's owner can always attach that PMC to itself. 1027 */ 1028 1029 if ((o = pm->pm_owner->po_owner) == t) 1030 return 0; 1031 1032 PROC_LOCK(o); 1033 oc = o->p_ucred; 1034 crhold(oc); 1035 PROC_UNLOCK(o); 1036 1037 PROC_LOCK(t); 1038 tc = t->p_ucred; 1039 crhold(tc); 1040 PROC_UNLOCK(t); 1041 1042 /* 1043 * The effective uid of the PMC owner should match at least one 1044 * of the {effective,real,saved} uids of the target process. 1045 */ 1046 1047 decline_attach = oc->cr_uid != tc->cr_uid && 1048 oc->cr_uid != tc->cr_svuid && 1049 oc->cr_uid != tc->cr_ruid; 1050 1051 /* 1052 * Every one of the target's group ids, must be in the owner's 1053 * group list. 1054 */ 1055 for (i = 0; !decline_attach && i < tc->cr_ngroups; i++) 1056 decline_attach = !groupmember(tc->cr_groups[i], oc); 1057 1058 /* check the read and saved gids too */ 1059 if (decline_attach == 0) 1060 decline_attach = !groupmember(tc->cr_rgid, oc) || 1061 !groupmember(tc->cr_svgid, oc); 1062 1063 crfree(tc); 1064 crfree(oc); 1065 1066 return !decline_attach; 1067 } 1068 1069 /* 1070 * Attach a process to a PMC. 1071 */ 1072 1073 static int 1074 pmc_attach_one_process(struct proc *p, struct pmc *pm) 1075 { 1076 int ri, error; 1077 char *fullpath, *freepath; 1078 struct pmc_process *pp; 1079 1080 sx_assert(&pmc_sx, SX_XLOCKED); 1081 1082 PMCDBG5(PRC,ATT,2, "attach-one pm=%p ri=%d proc=%p (%d, %s)", pm, 1083 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 1084 1085 /* 1086 * Locate the process descriptor corresponding to process 'p', 1087 * allocating space as needed. 1088 * 1089 * Verify that rowindex 'pm_rowindex' is free in the process 1090 * descriptor. 1091 * 1092 * If not, allocate space for a descriptor and link the 1093 * process descriptor and PMC. 1094 */ 1095 ri = PMC_TO_ROWINDEX(pm); 1096 1097 /* mark process as using HWPMCs */ 1098 PROC_LOCK(p); 1099 p->p_flag |= P_HWPMC; 1100 PROC_UNLOCK(p); 1101 1102 if ((pp = pmc_find_process_descriptor(p, PMC_FLAG_ALLOCATE)) == NULL) { 1103 error = ENOMEM; 1104 goto fail; 1105 } 1106 1107 if (pp->pp_pmcs[ri].pp_pmc == pm) {/* already present at slot [ri] */ 1108 error = EEXIST; 1109 goto fail; 1110 } 1111 1112 if (pp->pp_pmcs[ri].pp_pmc != NULL) { 1113 error = EBUSY; 1114 goto fail; 1115 } 1116 1117 pmc_link_target_process(pm, pp); 1118 1119 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)) && 1120 (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) == 0) 1121 pm->pm_flags |= PMC_F_NEEDS_LOGFILE; 1122 1123 pm->pm_flags |= PMC_F_ATTACH_DONE; /* mark as attached */ 1124 1125 /* issue an attach event to a configured log file */ 1126 if (pm->pm_owner->po_flags & PMC_PO_OWNS_LOGFILE) { 1127 if (p->p_flag & P_KPROC) { 1128 fullpath = kernelname; 1129 freepath = NULL; 1130 } else { 1131 pmc_getfilename(p->p_textvp, &fullpath, &freepath); 1132 pmclog_process_pmcattach(pm, p->p_pid, fullpath); 1133 } 1134 free(freepath, M_TEMP); 1135 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 1136 pmc_log_process_mappings(pm->pm_owner, p); 1137 } 1138 1139 return (0); 1140 fail: 1141 PROC_LOCK(p); 1142 p->p_flag &= ~P_HWPMC; 1143 PROC_UNLOCK(p); 1144 return (error); 1145 } 1146 1147 /* 1148 * Attach a process and optionally its children 1149 */ 1150 1151 static int 1152 pmc_attach_process(struct proc *p, struct pmc *pm) 1153 { 1154 int error; 1155 struct proc *top; 1156 1157 sx_assert(&pmc_sx, SX_XLOCKED); 1158 1159 PMCDBG5(PRC,ATT,1, "attach pm=%p ri=%d proc=%p (%d, %s)", pm, 1160 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 1161 1162 1163 /* 1164 * If this PMC successfully allowed a GETMSR operation 1165 * in the past, disallow further ATTACHes. 1166 */ 1167 1168 if ((pm->pm_flags & PMC_PP_ENABLE_MSR_ACCESS) != 0) 1169 return EPERM; 1170 1171 if ((pm->pm_flags & PMC_F_DESCENDANTS) == 0) 1172 return pmc_attach_one_process(p, pm); 1173 1174 /* 1175 * Traverse all child processes, attaching them to 1176 * this PMC. 1177 */ 1178 1179 sx_slock(&proctree_lock); 1180 1181 top = p; 1182 1183 for (;;) { 1184 if ((error = pmc_attach_one_process(p, pm)) != 0) 1185 break; 1186 if (!LIST_EMPTY(&p->p_children)) 1187 p = LIST_FIRST(&p->p_children); 1188 else for (;;) { 1189 if (p == top) 1190 goto done; 1191 if (LIST_NEXT(p, p_sibling)) { 1192 p = LIST_NEXT(p, p_sibling); 1193 break; 1194 } 1195 p = p->p_pptr; 1196 } 1197 } 1198 1199 if (error) 1200 (void) pmc_detach_process(top, pm); 1201 1202 done: 1203 sx_sunlock(&proctree_lock); 1204 return error; 1205 } 1206 1207 /* 1208 * Detach a process from a PMC. If there are no other PMCs tracking 1209 * this process, remove the process structure from its hash table. If 1210 * 'flags' contains PMC_FLAG_REMOVE, then free the process structure. 1211 */ 1212 1213 static int 1214 pmc_detach_one_process(struct proc *p, struct pmc *pm, int flags) 1215 { 1216 int ri; 1217 struct pmc_process *pp; 1218 1219 sx_assert(&pmc_sx, SX_XLOCKED); 1220 1221 KASSERT(pm != NULL, 1222 ("[pmc,%d] null pm pointer", __LINE__)); 1223 1224 ri = PMC_TO_ROWINDEX(pm); 1225 1226 PMCDBG6(PRC,ATT,2, "detach-one pm=%p ri=%d proc=%p (%d, %s) flags=0x%x", 1227 pm, ri, p, p->p_pid, p->p_comm, flags); 1228 1229 if ((pp = pmc_find_process_descriptor(p, 0)) == NULL) 1230 return ESRCH; 1231 1232 if (pp->pp_pmcs[ri].pp_pmc != pm) 1233 return EINVAL; 1234 1235 pmc_unlink_target_process(pm, pp); 1236 1237 /* Issue a detach entry if a log file is configured */ 1238 if (pm->pm_owner->po_flags & PMC_PO_OWNS_LOGFILE) 1239 pmclog_process_pmcdetach(pm, p->p_pid); 1240 1241 /* 1242 * If there are no PMCs targeting this process, we remove its 1243 * descriptor from the target hash table and unset the P_HWPMC 1244 * flag in the struct proc. 1245 */ 1246 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= (int) md->pmd_npmc, 1247 ("[pmc,%d] Illegal refcnt %d for process struct %p", 1248 __LINE__, pp->pp_refcnt, pp)); 1249 1250 if (pp->pp_refcnt != 0) /* still a target of some PMC */ 1251 return 0; 1252 1253 pmc_remove_process_descriptor(pp); 1254 1255 if (flags & PMC_FLAG_REMOVE) 1256 pmc_destroy_process_descriptor(pp); 1257 1258 PROC_LOCK(p); 1259 p->p_flag &= ~P_HWPMC; 1260 PROC_UNLOCK(p); 1261 1262 return 0; 1263 } 1264 1265 /* 1266 * Detach a process and optionally its descendants from a PMC. 1267 */ 1268 1269 static int 1270 pmc_detach_process(struct proc *p, struct pmc *pm) 1271 { 1272 struct proc *top; 1273 1274 sx_assert(&pmc_sx, SX_XLOCKED); 1275 1276 PMCDBG5(PRC,ATT,1, "detach pm=%p ri=%d proc=%p (%d, %s)", pm, 1277 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 1278 1279 if ((pm->pm_flags & PMC_F_DESCENDANTS) == 0) 1280 return pmc_detach_one_process(p, pm, PMC_FLAG_REMOVE); 1281 1282 /* 1283 * Traverse all children, detaching them from this PMC. We 1284 * ignore errors since we could be detaching a PMC from a 1285 * partially attached proc tree. 1286 */ 1287 1288 sx_slock(&proctree_lock); 1289 1290 top = p; 1291 1292 for (;;) { 1293 (void) pmc_detach_one_process(p, pm, PMC_FLAG_REMOVE); 1294 1295 if (!LIST_EMPTY(&p->p_children)) 1296 p = LIST_FIRST(&p->p_children); 1297 else for (;;) { 1298 if (p == top) 1299 goto done; 1300 if (LIST_NEXT(p, p_sibling)) { 1301 p = LIST_NEXT(p, p_sibling); 1302 break; 1303 } 1304 p = p->p_pptr; 1305 } 1306 } 1307 1308 done: 1309 sx_sunlock(&proctree_lock); 1310 1311 if (LIST_EMPTY(&pm->pm_targets)) 1312 pm->pm_flags &= ~PMC_F_ATTACH_DONE; 1313 1314 return 0; 1315 } 1316 1317 1318 /* 1319 * Thread context switch IN 1320 */ 1321 1322 static void 1323 pmc_process_csw_in(struct thread *td) 1324 { 1325 int cpu; 1326 unsigned int adjri, ri; 1327 struct pmc *pm; 1328 struct proc *p; 1329 struct pmc_cpu *pc; 1330 struct pmc_hw *phw; 1331 pmc_value_t newvalue; 1332 struct pmc_process *pp; 1333 struct pmc_thread *pt; 1334 struct pmc_classdep *pcd; 1335 1336 p = td->td_proc; 1337 pt = NULL; 1338 if ((pp = pmc_find_process_descriptor(p, PMC_FLAG_NONE)) == NULL) 1339 return; 1340 1341 KASSERT(pp->pp_proc == td->td_proc, 1342 ("[pmc,%d] not my thread state", __LINE__)); 1343 1344 critical_enter(); /* no preemption from this point */ 1345 1346 cpu = PCPU_GET(cpuid); /* td->td_oncpu is invalid */ 1347 1348 PMCDBG5(CSW,SWI,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p, 1349 p->p_pid, p->p_comm, pp); 1350 1351 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 1352 ("[pmc,%d] weird CPU id %d", __LINE__, cpu)); 1353 1354 pc = pmc_pcpu[cpu]; 1355 1356 for (ri = 0; ri < md->pmd_npmc; ri++) { 1357 1358 if ((pm = pp->pp_pmcs[ri].pp_pmc) == NULL) 1359 continue; 1360 1361 KASSERT(PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)), 1362 ("[pmc,%d] Target PMC in non-virtual mode (%d)", 1363 __LINE__, PMC_TO_MODE(pm))); 1364 1365 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 1366 ("[pmc,%d] Row index mismatch pmc %d != ri %d", 1367 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 1368 1369 /* 1370 * Only PMCs that are marked as 'RUNNING' need 1371 * be placed on hardware. 1372 */ 1373 1374 if (pm->pm_state != PMC_STATE_RUNNING) 1375 continue; 1376 1377 /* increment PMC runcount */ 1378 counter_u64_add(pm->pm_runcount, 1); 1379 1380 /* configure the HWPMC we are going to use. */ 1381 pcd = pmc_ri_to_classdep(md, ri, &adjri); 1382 pcd->pcd_config_pmc(cpu, adjri, pm); 1383 1384 phw = pc->pc_hwpmcs[ri]; 1385 1386 KASSERT(phw != NULL, 1387 ("[pmc,%d] null hw pointer", __LINE__)); 1388 1389 KASSERT(phw->phw_pmc == pm, 1390 ("[pmc,%d] hw->pmc %p != pmc %p", __LINE__, 1391 phw->phw_pmc, pm)); 1392 1393 /* 1394 * Write out saved value and start the PMC. 1395 * 1396 * Sampling PMCs use a per-thread value, while 1397 * counting mode PMCs use a per-pmc value that is 1398 * inherited across descendants. 1399 */ 1400 if (PMC_TO_MODE(pm) == PMC_MODE_TS) { 1401 if (pt == NULL) 1402 pt = pmc_find_thread_descriptor(pp, td, 1403 PMC_FLAG_NONE); 1404 1405 KASSERT(pt != NULL, 1406 ("[pmc,%d] No thread found for td=%p", __LINE__, 1407 td)); 1408 1409 mtx_pool_lock_spin(pmc_mtxpool, pm); 1410 1411 /* 1412 * If we have a thread descriptor, use the per-thread 1413 * counter in the descriptor. If not, we will use 1414 * a per-process counter. 1415 * 1416 * TODO: Remove the per-process "safety net" once 1417 * we have thoroughly tested that we don't hit the 1418 * above assert. 1419 */ 1420 if (pt != NULL) { 1421 if (pt->pt_pmcs[ri].pt_pmcval > 0) 1422 newvalue = pt->pt_pmcs[ri].pt_pmcval; 1423 else 1424 newvalue = pm->pm_sc.pm_reloadcount; 1425 } else { 1426 /* 1427 * Use the saved value calculated after the most 1428 * recent time a thread using the shared counter 1429 * switched out. Reset the saved count in case 1430 * another thread from this process switches in 1431 * before any threads switch out. 1432 */ 1433 1434 newvalue = pp->pp_pmcs[ri].pp_pmcval; 1435 pp->pp_pmcs[ri].pp_pmcval = 1436 pm->pm_sc.pm_reloadcount; 1437 } 1438 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1439 KASSERT(newvalue > 0 && newvalue <= 1440 pm->pm_sc.pm_reloadcount, 1441 ("[pmc,%d] pmcval outside of expected range cpu=%d " 1442 "ri=%d pmcval=%jx pm_reloadcount=%jx", __LINE__, 1443 cpu, ri, newvalue, pm->pm_sc.pm_reloadcount)); 1444 } else { 1445 KASSERT(PMC_TO_MODE(pm) == PMC_MODE_TC, 1446 ("[pmc,%d] illegal mode=%d", __LINE__, 1447 PMC_TO_MODE(pm))); 1448 mtx_pool_lock_spin(pmc_mtxpool, pm); 1449 newvalue = PMC_PCPU_SAVED(cpu, ri) = 1450 pm->pm_gv.pm_savedvalue; 1451 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1452 } 1453 1454 PMCDBG3(CSW,SWI,1,"cpu=%d ri=%d new=%jd", cpu, ri, newvalue); 1455 1456 pcd->pcd_write_pmc(cpu, adjri, newvalue); 1457 1458 /* If a sampling mode PMC, reset stalled state. */ 1459 if (PMC_TO_MODE(pm) == PMC_MODE_TS) 1460 pm->pm_pcpu_state[cpu].pps_stalled = 0; 1461 1462 /* Indicate that we desire this to run. */ 1463 pm->pm_pcpu_state[cpu].pps_cpustate = 1; 1464 1465 /* Start the PMC. */ 1466 pcd->pcd_start_pmc(cpu, adjri); 1467 } 1468 1469 /* 1470 * perform any other architecture/cpu dependent thread 1471 * switch-in actions. 1472 */ 1473 1474 (void) (*md->pmd_switch_in)(pc, pp); 1475 1476 critical_exit(); 1477 1478 } 1479 1480 /* 1481 * Thread context switch OUT. 1482 */ 1483 1484 static void 1485 pmc_process_csw_out(struct thread *td) 1486 { 1487 int cpu; 1488 int64_t tmp; 1489 struct pmc *pm; 1490 struct proc *p; 1491 enum pmc_mode mode; 1492 struct pmc_cpu *pc; 1493 pmc_value_t newvalue; 1494 unsigned int adjri, ri; 1495 struct pmc_process *pp; 1496 struct pmc_thread *pt = NULL; 1497 struct pmc_classdep *pcd; 1498 1499 1500 /* 1501 * Locate our process descriptor; this may be NULL if 1502 * this process is exiting and we have already removed 1503 * the process from the target process table. 1504 * 1505 * Note that due to kernel preemption, multiple 1506 * context switches may happen while the process is 1507 * exiting. 1508 * 1509 * Note also that if the target process cannot be 1510 * found we still need to deconfigure any PMCs that 1511 * are currently running on hardware. 1512 */ 1513 1514 p = td->td_proc; 1515 pp = pmc_find_process_descriptor(p, PMC_FLAG_NONE); 1516 1517 /* 1518 * save PMCs 1519 */ 1520 1521 critical_enter(); 1522 1523 cpu = PCPU_GET(cpuid); /* td->td_oncpu is invalid */ 1524 1525 PMCDBG5(CSW,SWO,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p, 1526 p->p_pid, p->p_comm, pp); 1527 1528 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 1529 ("[pmc,%d weird CPU id %d", __LINE__, cpu)); 1530 1531 pc = pmc_pcpu[cpu]; 1532 1533 /* 1534 * When a PMC gets unlinked from a target PMC, it will 1535 * be removed from the target's pp_pmc[] array. 1536 * 1537 * However, on a MP system, the target could have been 1538 * executing on another CPU at the time of the unlink. 1539 * So, at context switch OUT time, we need to look at 1540 * the hardware to determine if a PMC is scheduled on 1541 * it. 1542 */ 1543 1544 for (ri = 0; ri < md->pmd_npmc; ri++) { 1545 1546 pcd = pmc_ri_to_classdep(md, ri, &adjri); 1547 pm = NULL; 1548 (void) (*pcd->pcd_get_config)(cpu, adjri, &pm); 1549 1550 if (pm == NULL) /* nothing at this row index */ 1551 continue; 1552 1553 mode = PMC_TO_MODE(pm); 1554 if (!PMC_IS_VIRTUAL_MODE(mode)) 1555 continue; /* not a process virtual PMC */ 1556 1557 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 1558 ("[pmc,%d] ri mismatch pmc(%d) ri(%d)", 1559 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 1560 1561 /* 1562 * Change desired state, and then stop if not stalled. 1563 * This two-step dance should avoid race conditions where 1564 * an interrupt re-enables the PMC after this code has 1565 * already checked the pm_stalled flag. 1566 */ 1567 pm->pm_pcpu_state[cpu].pps_cpustate = 0; 1568 if (pm->pm_pcpu_state[cpu].pps_stalled == 0) 1569 pcd->pcd_stop_pmc(cpu, adjri); 1570 1571 /* reduce this PMC's runcount */ 1572 counter_u64_add(pm->pm_runcount, -1); 1573 1574 /* 1575 * If this PMC is associated with this process, 1576 * save the reading. 1577 */ 1578 1579 if (pm->pm_state != PMC_STATE_DELETED && pp != NULL && 1580 pp->pp_pmcs[ri].pp_pmc != NULL) { 1581 KASSERT(pm == pp->pp_pmcs[ri].pp_pmc, 1582 ("[pmc,%d] pm %p != pp_pmcs[%d] %p", __LINE__, 1583 pm, ri, pp->pp_pmcs[ri].pp_pmc)); 1584 1585 KASSERT(pp->pp_refcnt > 0, 1586 ("[pmc,%d] pp refcnt = %d", __LINE__, 1587 pp->pp_refcnt)); 1588 1589 pcd->pcd_read_pmc(cpu, adjri, &newvalue); 1590 1591 if (mode == PMC_MODE_TS) { 1592 PMCDBG3(CSW,SWO,1,"cpu=%d ri=%d val=%jd (samp)", 1593 cpu, ri, newvalue); 1594 1595 if (pt == NULL) 1596 pt = pmc_find_thread_descriptor(pp, td, 1597 PMC_FLAG_NONE); 1598 1599 KASSERT(pt != NULL, 1600 ("[pmc,%d] No thread found for td=%p", 1601 __LINE__, td)); 1602 1603 mtx_pool_lock_spin(pmc_mtxpool, pm); 1604 1605 /* 1606 * If we have a thread descriptor, save the 1607 * per-thread counter in the descriptor. If not, 1608 * we will update the per-process counter. 1609 * 1610 * TODO: Remove the per-process "safety net" 1611 * once we have thoroughly tested that we 1612 * don't hit the above assert. 1613 */ 1614 if (pt != NULL) 1615 pt->pt_pmcs[ri].pt_pmcval = newvalue; 1616 else { 1617 /* 1618 * For sampling process-virtual PMCs, 1619 * newvalue is the number of events to 1620 * be seen until the next sampling 1621 * interrupt. We can just add the events 1622 * left from this invocation to the 1623 * counter, then adjust in case we 1624 * overflow our range. 1625 * 1626 * (Recall that we reload the counter 1627 * every time we use it.) 1628 */ 1629 pp->pp_pmcs[ri].pp_pmcval += newvalue; 1630 if (pp->pp_pmcs[ri].pp_pmcval > 1631 pm->pm_sc.pm_reloadcount) 1632 pp->pp_pmcs[ri].pp_pmcval -= 1633 pm->pm_sc.pm_reloadcount; 1634 } 1635 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1636 } else { 1637 tmp = newvalue - PMC_PCPU_SAVED(cpu,ri); 1638 1639 PMCDBG3(CSW,SWO,1,"cpu=%d ri=%d tmp=%jd (count)", 1640 cpu, ri, tmp); 1641 1642 /* 1643 * For counting process-virtual PMCs, 1644 * we expect the count to be 1645 * increasing monotonically, modulo a 64 1646 * bit wraparound. 1647 */ 1648 KASSERT(tmp >= 0, 1649 ("[pmc,%d] negative increment cpu=%d " 1650 "ri=%d newvalue=%jx saved=%jx " 1651 "incr=%jx", __LINE__, cpu, ri, 1652 newvalue, PMC_PCPU_SAVED(cpu,ri), tmp)); 1653 1654 mtx_pool_lock_spin(pmc_mtxpool, pm); 1655 pm->pm_gv.pm_savedvalue += tmp; 1656 pp->pp_pmcs[ri].pp_pmcval += tmp; 1657 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1658 1659 if (pm->pm_flags & PMC_F_LOG_PROCCSW) 1660 pmclog_process_proccsw(pm, pp, tmp, td); 1661 } 1662 } 1663 1664 /* mark hardware as free */ 1665 pcd->pcd_config_pmc(cpu, adjri, NULL); 1666 } 1667 1668 /* 1669 * perform any other architecture/cpu dependent thread 1670 * switch out functions. 1671 */ 1672 1673 (void) (*md->pmd_switch_out)(pc, pp); 1674 1675 critical_exit(); 1676 } 1677 1678 /* 1679 * A new thread for a process. 1680 */ 1681 static void 1682 pmc_process_thread_add(struct thread *td) 1683 { 1684 struct pmc_process *pmc; 1685 1686 pmc = pmc_find_process_descriptor(td->td_proc, PMC_FLAG_NONE); 1687 if (pmc != NULL) 1688 pmc_find_thread_descriptor(pmc, td, PMC_FLAG_ALLOCATE); 1689 } 1690 1691 /* 1692 * A thread delete for a process. 1693 */ 1694 static void 1695 pmc_process_thread_delete(struct thread *td) 1696 { 1697 struct pmc_process *pmc; 1698 1699 pmc = pmc_find_process_descriptor(td->td_proc, PMC_FLAG_NONE); 1700 if (pmc != NULL) 1701 pmc_thread_descriptor_pool_free(pmc_find_thread_descriptor(pmc, 1702 td, PMC_FLAG_REMOVE)); 1703 } 1704 1705 /* 1706 * A mapping change for a process. 1707 */ 1708 1709 static void 1710 pmc_process_mmap(struct thread *td, struct pmckern_map_in *pkm) 1711 { 1712 int ri; 1713 pid_t pid; 1714 char *fullpath, *freepath; 1715 const struct pmc *pm; 1716 struct pmc_owner *po; 1717 const struct pmc_process *pp; 1718 1719 freepath = fullpath = NULL; 1720 MPASS(!in_epoch()); 1721 pmc_getfilename((struct vnode *) pkm->pm_file, &fullpath, &freepath); 1722 1723 pid = td->td_proc->p_pid; 1724 1725 epoch_enter_preempt(global_epoch_preempt); 1726 /* Inform owners of all system-wide sampling PMCs. */ 1727 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1728 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1729 pmclog_process_map_in(po, pid, pkm->pm_address, fullpath); 1730 1731 if ((pp = pmc_find_process_descriptor(td->td_proc, 0)) == NULL) 1732 goto done; 1733 1734 /* 1735 * Inform sampling PMC owners tracking this process. 1736 */ 1737 for (ri = 0; ri < md->pmd_npmc; ri++) 1738 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL && 1739 PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 1740 pmclog_process_map_in(pm->pm_owner, 1741 pid, pkm->pm_address, fullpath); 1742 1743 done: 1744 if (freepath) 1745 free(freepath, M_TEMP); 1746 epoch_exit_preempt(global_epoch_preempt); 1747 } 1748 1749 1750 /* 1751 * Log an munmap request. 1752 */ 1753 1754 static void 1755 pmc_process_munmap(struct thread *td, struct pmckern_map_out *pkm) 1756 { 1757 int ri; 1758 pid_t pid; 1759 struct pmc_owner *po; 1760 const struct pmc *pm; 1761 const struct pmc_process *pp; 1762 1763 pid = td->td_proc->p_pid; 1764 1765 epoch_enter_preempt(global_epoch_preempt); 1766 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1767 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1768 pmclog_process_map_out(po, pid, pkm->pm_address, 1769 pkm->pm_address + pkm->pm_size); 1770 epoch_exit_preempt(global_epoch_preempt); 1771 1772 if ((pp = pmc_find_process_descriptor(td->td_proc, 0)) == NULL) 1773 return; 1774 1775 for (ri = 0; ri < md->pmd_npmc; ri++) 1776 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL && 1777 PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 1778 pmclog_process_map_out(pm->pm_owner, pid, 1779 pkm->pm_address, pkm->pm_address + pkm->pm_size); 1780 } 1781 1782 /* 1783 * Log mapping information about the kernel. 1784 */ 1785 1786 static void 1787 pmc_log_kernel_mappings(struct pmc *pm) 1788 { 1789 struct pmc_owner *po; 1790 struct pmckern_map_in *km, *kmbase; 1791 1792 MPASS(in_epoch() || sx_xlocked(&pmc_sx)); 1793 KASSERT(PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)), 1794 ("[pmc,%d] non-sampling PMC (%p) desires mapping information", 1795 __LINE__, (void *) pm)); 1796 1797 po = pm->pm_owner; 1798 1799 if (po->po_flags & PMC_PO_INITIAL_MAPPINGS_DONE) 1800 return; 1801 1802 /* 1803 * Log the current set of kernel modules. 1804 */ 1805 kmbase = linker_hwpmc_list_objects(); 1806 for (km = kmbase; km->pm_file != NULL; km++) { 1807 PMCDBG2(LOG,REG,1,"%s %p", (char *) km->pm_file, 1808 (void *) km->pm_address); 1809 pmclog_process_map_in(po, (pid_t) -1, km->pm_address, 1810 km->pm_file); 1811 } 1812 free(kmbase, M_LINKER); 1813 1814 po->po_flags |= PMC_PO_INITIAL_MAPPINGS_DONE; 1815 } 1816 1817 /* 1818 * Log the mappings for a single process. 1819 */ 1820 1821 static void 1822 pmc_log_process_mappings(struct pmc_owner *po, struct proc *p) 1823 { 1824 vm_map_t map; 1825 struct vnode *vp; 1826 struct vmspace *vm; 1827 vm_map_entry_t entry; 1828 vm_offset_t last_end; 1829 u_int last_timestamp; 1830 struct vnode *last_vp; 1831 vm_offset_t start_addr; 1832 vm_object_t obj, lobj, tobj; 1833 char *fullpath, *freepath; 1834 1835 last_vp = NULL; 1836 last_end = (vm_offset_t) 0; 1837 fullpath = freepath = NULL; 1838 1839 if ((vm = vmspace_acquire_ref(p)) == NULL) 1840 return; 1841 1842 map = &vm->vm_map; 1843 vm_map_lock_read(map); 1844 1845 for (entry = map->header.next; entry != &map->header; entry = entry->next) { 1846 1847 if (entry == NULL) { 1848 PMCDBG2(LOG,OPS,2, "hwpmc: vm_map entry unexpectedly " 1849 "NULL! pid=%d vm_map=%p\n", p->p_pid, map); 1850 break; 1851 } 1852 1853 /* 1854 * We only care about executable map entries. 1855 */ 1856 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) || 1857 !(entry->protection & VM_PROT_EXECUTE) || 1858 (entry->object.vm_object == NULL)) { 1859 continue; 1860 } 1861 1862 obj = entry->object.vm_object; 1863 VM_OBJECT_RLOCK(obj); 1864 1865 /* 1866 * Walk the backing_object list to find the base 1867 * (non-shadowed) vm_object. 1868 */ 1869 for (lobj = tobj = obj; tobj != NULL; tobj = tobj->backing_object) { 1870 if (tobj != obj) 1871 VM_OBJECT_RLOCK(tobj); 1872 if (lobj != obj) 1873 VM_OBJECT_RUNLOCK(lobj); 1874 lobj = tobj; 1875 } 1876 1877 /* 1878 * At this point lobj is the base vm_object and it is locked. 1879 */ 1880 if (lobj == NULL) { 1881 PMCDBG3(LOG,OPS,2, "hwpmc: lobj unexpectedly NULL! pid=%d " 1882 "vm_map=%p vm_obj=%p\n", p->p_pid, map, obj); 1883 VM_OBJECT_RUNLOCK(obj); 1884 continue; 1885 } 1886 1887 vp = vm_object_vnode(lobj); 1888 if (vp == NULL) { 1889 if (lobj != obj) 1890 VM_OBJECT_RUNLOCK(lobj); 1891 VM_OBJECT_RUNLOCK(obj); 1892 continue; 1893 } 1894 1895 /* 1896 * Skip contiguous regions that point to the same 1897 * vnode, so we don't emit redundant MAP-IN 1898 * directives. 1899 */ 1900 if (entry->start == last_end && vp == last_vp) { 1901 last_end = entry->end; 1902 if (lobj != obj) 1903 VM_OBJECT_RUNLOCK(lobj); 1904 VM_OBJECT_RUNLOCK(obj); 1905 continue; 1906 } 1907 1908 /* 1909 * We don't want to keep the proc's vm_map or this 1910 * vm_object locked while we walk the pathname, since 1911 * vn_fullpath() can sleep. However, if we drop the 1912 * lock, it's possible for concurrent activity to 1913 * modify the vm_map list. To protect against this, 1914 * we save the vm_map timestamp before we release the 1915 * lock, and check it after we reacquire the lock 1916 * below. 1917 */ 1918 start_addr = entry->start; 1919 last_end = entry->end; 1920 last_timestamp = map->timestamp; 1921 vm_map_unlock_read(map); 1922 1923 vref(vp); 1924 if (lobj != obj) 1925 VM_OBJECT_RUNLOCK(lobj); 1926 1927 VM_OBJECT_RUNLOCK(obj); 1928 1929 freepath = NULL; 1930 pmc_getfilename(vp, &fullpath, &freepath); 1931 last_vp = vp; 1932 1933 vrele(vp); 1934 1935 vp = NULL; 1936 pmclog_process_map_in(po, p->p_pid, start_addr, fullpath); 1937 if (freepath) 1938 free(freepath, M_TEMP); 1939 1940 vm_map_lock_read(map); 1941 1942 /* 1943 * If our saved timestamp doesn't match, this means 1944 * that the vm_map was modified out from under us and 1945 * we can't trust our current "entry" pointer. Do a 1946 * new lookup for this entry. If there is no entry 1947 * for this address range, vm_map_lookup_entry() will 1948 * return the previous one, so we always want to go to 1949 * entry->next on the next loop iteration. 1950 * 1951 * There is an edge condition here that can occur if 1952 * there is no entry at or before this address. In 1953 * this situation, vm_map_lookup_entry returns 1954 * &map->header, which would cause our loop to abort 1955 * without processing the rest of the map. However, 1956 * in practice this will never happen for process 1957 * vm_map. This is because the executable's text 1958 * segment is the first mapping in the proc's address 1959 * space, and this mapping is never removed until the 1960 * process exits, so there will always be a non-header 1961 * entry at or before the requested address for 1962 * vm_map_lookup_entry to return. 1963 */ 1964 if (map->timestamp != last_timestamp) 1965 vm_map_lookup_entry(map, last_end - 1, &entry); 1966 } 1967 1968 vm_map_unlock_read(map); 1969 vmspace_free(vm); 1970 return; 1971 } 1972 1973 /* 1974 * Log mappings for all processes in the system. 1975 */ 1976 1977 static void 1978 pmc_log_all_process_mappings(struct pmc_owner *po) 1979 { 1980 struct proc *p, *top; 1981 1982 sx_assert(&pmc_sx, SX_XLOCKED); 1983 1984 if ((p = pfind(1)) == NULL) 1985 panic("[pmc,%d] Cannot find init", __LINE__); 1986 1987 PROC_UNLOCK(p); 1988 1989 sx_slock(&proctree_lock); 1990 1991 top = p; 1992 1993 for (;;) { 1994 pmc_log_process_mappings(po, p); 1995 if (!LIST_EMPTY(&p->p_children)) 1996 p = LIST_FIRST(&p->p_children); 1997 else for (;;) { 1998 if (p == top) 1999 goto done; 2000 if (LIST_NEXT(p, p_sibling)) { 2001 p = LIST_NEXT(p, p_sibling); 2002 break; 2003 } 2004 p = p->p_pptr; 2005 } 2006 } 2007 done: 2008 sx_sunlock(&proctree_lock); 2009 } 2010 2011 /* 2012 * The 'hook' invoked from the kernel proper 2013 */ 2014 2015 2016 #ifdef HWPMC_DEBUG 2017 const char *pmc_hooknames[] = { 2018 /* these strings correspond to PMC_FN_* in <sys/pmckern.h> */ 2019 "", 2020 "EXEC", 2021 "CSW-IN", 2022 "CSW-OUT", 2023 "SAMPLE", 2024 "UNUSED1", 2025 "UNUSED2", 2026 "MMAP", 2027 "MUNMAP", 2028 "CALLCHAIN-NMI", 2029 "CALLCHAIN-SOFT", 2030 "SOFTSAMPLING", 2031 "THR-CREATE", 2032 "THR-EXIT", 2033 }; 2034 #endif 2035 2036 static int 2037 pmc_hook_handler(struct thread *td, int function, void *arg) 2038 { 2039 int cpu; 2040 2041 PMCDBG4(MOD,PMH,1, "hook td=%p func=%d \"%s\" arg=%p", td, function, 2042 pmc_hooknames[function], arg); 2043 2044 switch (function) 2045 { 2046 2047 /* 2048 * Process exec() 2049 */ 2050 2051 case PMC_FN_PROCESS_EXEC: 2052 { 2053 char *fullpath, *freepath; 2054 unsigned int ri; 2055 int is_using_hwpmcs; 2056 struct pmc *pm; 2057 struct proc *p; 2058 struct pmc_owner *po; 2059 struct pmc_process *pp; 2060 struct pmckern_procexec *pk; 2061 2062 sx_assert(&pmc_sx, SX_XLOCKED); 2063 2064 p = td->td_proc; 2065 pmc_getfilename(p->p_textvp, &fullpath, &freepath); 2066 2067 pk = (struct pmckern_procexec *) arg; 2068 2069 epoch_enter_preempt(global_epoch_preempt); 2070 /* Inform owners of SS mode PMCs of the exec event. */ 2071 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 2072 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 2073 pmclog_process_procexec(po, PMC_ID_INVALID, 2074 p->p_pid, pk->pm_entryaddr, fullpath); 2075 epoch_exit_preempt(global_epoch_preempt); 2076 2077 PROC_LOCK(p); 2078 is_using_hwpmcs = p->p_flag & P_HWPMC; 2079 PROC_UNLOCK(p); 2080 2081 if (!is_using_hwpmcs) { 2082 if (freepath) 2083 free(freepath, M_TEMP); 2084 break; 2085 } 2086 2087 /* 2088 * PMCs are not inherited across an exec(): remove any 2089 * PMCs that this process is the owner of. 2090 */ 2091 2092 if ((po = pmc_find_owner_descriptor(p)) != NULL) { 2093 pmc_remove_owner(po); 2094 pmc_destroy_owner_descriptor(po); 2095 } 2096 2097 /* 2098 * If the process being exec'ed is not the target of any 2099 * PMC, we are done. 2100 */ 2101 if ((pp = pmc_find_process_descriptor(p, 0)) == NULL) { 2102 if (freepath) 2103 free(freepath, M_TEMP); 2104 break; 2105 } 2106 2107 /* 2108 * Log the exec event to all monitoring owners. Skip 2109 * owners who have already received the event because 2110 * they had system sampling PMCs active. 2111 */ 2112 for (ri = 0; ri < md->pmd_npmc; ri++) 2113 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) { 2114 po = pm->pm_owner; 2115 if (po->po_sscount == 0 && 2116 po->po_flags & PMC_PO_OWNS_LOGFILE) 2117 pmclog_process_procexec(po, pm->pm_id, 2118 p->p_pid, pk->pm_entryaddr, 2119 fullpath); 2120 } 2121 2122 if (freepath) 2123 free(freepath, M_TEMP); 2124 2125 2126 PMCDBG4(PRC,EXC,1, "exec proc=%p (%d, %s) cred-changed=%d", 2127 p, p->p_pid, p->p_comm, pk->pm_credentialschanged); 2128 2129 if (pk->pm_credentialschanged == 0) /* no change */ 2130 break; 2131 2132 /* 2133 * If the newly exec()'ed process has a different credential 2134 * than before, allow it to be the target of a PMC only if 2135 * the PMC's owner has sufficient privilege. 2136 */ 2137 2138 for (ri = 0; ri < md->pmd_npmc; ri++) 2139 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) 2140 if (pmc_can_attach(pm, td->td_proc) != 0) 2141 pmc_detach_one_process(td->td_proc, 2142 pm, PMC_FLAG_NONE); 2143 2144 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= (int) md->pmd_npmc, 2145 ("[pmc,%d] Illegal ref count %d on pp %p", __LINE__, 2146 pp->pp_refcnt, pp)); 2147 2148 /* 2149 * If this process is no longer the target of any 2150 * PMCs, we can remove the process entry and free 2151 * up space. 2152 */ 2153 2154 if (pp->pp_refcnt == 0) { 2155 pmc_remove_process_descriptor(pp); 2156 pmc_destroy_process_descriptor(pp); 2157 break; 2158 } 2159 2160 } 2161 break; 2162 2163 case PMC_FN_CSW_IN: 2164 pmc_process_csw_in(td); 2165 break; 2166 2167 case PMC_FN_CSW_OUT: 2168 pmc_process_csw_out(td); 2169 break; 2170 2171 /* 2172 * Process accumulated PC samples. 2173 * 2174 * This function is expected to be called by hardclock() for 2175 * each CPU that has accumulated PC samples. 2176 * 2177 * This function is to be executed on the CPU whose samples 2178 * are being processed. 2179 */ 2180 case PMC_FN_DO_SAMPLES: 2181 2182 /* 2183 * Clear the cpu specific bit in the CPU mask before 2184 * do the rest of the processing. If the NMI handler 2185 * gets invoked after the "atomic_clear_int()" call 2186 * below but before "pmc_process_samples()" gets 2187 * around to processing the interrupt, then we will 2188 * come back here at the next hardclock() tick (and 2189 * may find nothing to do if "pmc_process_samples()" 2190 * had already processed the interrupt). We don't 2191 * lose the interrupt sample. 2192 */ 2193 DPCPU_SET(pmc_sampled, 0); 2194 cpu = PCPU_GET(cpuid); 2195 pmc_process_samples(cpu, PMC_HR); 2196 pmc_process_samples(cpu, PMC_SR); 2197 break; 2198 2199 case PMC_FN_MMAP: 2200 MPASS(in_epoch() || sx_xlocked(&pmc_sx)); 2201 pmc_process_mmap(td, (struct pmckern_map_in *) arg); 2202 break; 2203 2204 case PMC_FN_MUNMAP: 2205 MPASS(in_epoch() || sx_xlocked(&pmc_sx)); 2206 pmc_process_munmap(td, (struct pmckern_map_out *) arg); 2207 break; 2208 2209 case PMC_FN_USER_CALLCHAIN: 2210 /* 2211 * Record a call chain. 2212 */ 2213 KASSERT(td == curthread, ("[pmc,%d] td != curthread", 2214 __LINE__)); 2215 2216 pmc_capture_user_callchain(PCPU_GET(cpuid), PMC_HR, 2217 (struct trapframe *) arg); 2218 td->td_pflags &= ~TDP_CALLCHAIN; 2219 break; 2220 2221 case PMC_FN_USER_CALLCHAIN_SOFT: 2222 /* 2223 * Record a call chain. 2224 */ 2225 KASSERT(td == curthread, ("[pmc,%d] td != curthread", 2226 __LINE__)); 2227 pmc_capture_user_callchain(PCPU_GET(cpuid), PMC_SR, 2228 (struct trapframe *) arg); 2229 td->td_pflags &= ~TDP_CALLCHAIN; 2230 break; 2231 2232 case PMC_FN_SOFT_SAMPLING: 2233 /* 2234 * Call soft PMC sampling intr. 2235 */ 2236 pmc_soft_intr((struct pmckern_soft *) arg); 2237 break; 2238 2239 case PMC_FN_THR_CREATE: 2240 pmc_process_thread_add(td); 2241 break; 2242 2243 case PMC_FN_THR_EXIT: 2244 KASSERT(td == curthread, ("[pmc,%d] td != curthread", 2245 __LINE__)); 2246 pmc_process_thread_delete(td); 2247 break; 2248 2249 default: 2250 #ifdef HWPMC_DEBUG 2251 KASSERT(0, ("[pmc,%d] unknown hook %d\n", __LINE__, function)); 2252 #endif 2253 break; 2254 2255 } 2256 2257 return 0; 2258 } 2259 2260 /* 2261 * allocate a 'struct pmc_owner' descriptor in the owner hash table. 2262 */ 2263 2264 static struct pmc_owner * 2265 pmc_allocate_owner_descriptor(struct proc *p) 2266 { 2267 uint32_t hindex; 2268 struct pmc_owner *po; 2269 struct pmc_ownerhash *poh; 2270 2271 hindex = PMC_HASH_PTR(p, pmc_ownerhashmask); 2272 poh = &pmc_ownerhash[hindex]; 2273 2274 /* allocate space for N pointers and one descriptor struct */ 2275 po = malloc(sizeof(struct pmc_owner), M_PMC, M_WAITOK|M_ZERO); 2276 po->po_owner = p; 2277 LIST_INSERT_HEAD(poh, po, po_next); /* insert into hash table */ 2278 2279 TAILQ_INIT(&po->po_logbuffers); 2280 mtx_init(&po->po_mtx, "pmc-owner-mtx", "pmc-per-proc", MTX_SPIN); 2281 2282 PMCDBG4(OWN,ALL,1, "allocate-owner proc=%p (%d, %s) pmc-owner=%p", 2283 p, p->p_pid, p->p_comm, po); 2284 2285 return po; 2286 } 2287 2288 static void 2289 pmc_destroy_owner_descriptor(struct pmc_owner *po) 2290 { 2291 2292 PMCDBG4(OWN,REL,1, "destroy-owner po=%p proc=%p (%d, %s)", 2293 po, po->po_owner, po->po_owner->p_pid, po->po_owner->p_comm); 2294 2295 mtx_destroy(&po->po_mtx); 2296 free(po, M_PMC); 2297 } 2298 2299 /* 2300 * Allocate a thread descriptor from the free pool. 2301 * 2302 * NOTE: This *can* return NULL. 2303 */ 2304 static struct pmc_thread * 2305 pmc_thread_descriptor_pool_alloc(void) 2306 { 2307 struct pmc_thread *pt; 2308 2309 mtx_lock_spin(&pmc_threadfreelist_mtx); 2310 if ((pt = LIST_FIRST(&pmc_threadfreelist)) != NULL) { 2311 LIST_REMOVE(pt, pt_next); 2312 pmc_threadfreelist_entries--; 2313 } 2314 mtx_unlock_spin(&pmc_threadfreelist_mtx); 2315 2316 return (pt); 2317 } 2318 2319 /* 2320 * Add a thread descriptor to the free pool. We use this instead of free() 2321 * to maintain a cache of free entries. Additionally, we can safely call 2322 * this function when we cannot call free(), such as in a critical section. 2323 * 2324 */ 2325 static void 2326 pmc_thread_descriptor_pool_free(struct pmc_thread *pt) 2327 { 2328 2329 if (pt == NULL) 2330 return; 2331 2332 memset(pt, 0, THREADENTRY_SIZE); 2333 mtx_lock_spin(&pmc_threadfreelist_mtx); 2334 LIST_INSERT_HEAD(&pmc_threadfreelist, pt, pt_next); 2335 pmc_threadfreelist_entries++; 2336 if (pmc_threadfreelist_entries > pmc_threadfreelist_max) 2337 GROUPTASK_ENQUEUE(&free_gtask); 2338 mtx_unlock_spin(&pmc_threadfreelist_mtx); 2339 } 2340 2341 /* 2342 * A callout to manage the free list. 2343 */ 2344 static void 2345 pmc_thread_descriptor_pool_free_task(void *arg __unused) 2346 { 2347 struct pmc_thread *pt; 2348 LIST_HEAD(, pmc_thread) tmplist; 2349 int delta; 2350 2351 LIST_INIT(&tmplist); 2352 /* Determine what changes, if any, we need to make. */ 2353 mtx_lock_spin(&pmc_threadfreelist_mtx); 2354 delta = pmc_threadfreelist_entries - pmc_threadfreelist_max; 2355 while (delta > 0 && 2356 (pt = LIST_FIRST(&pmc_threadfreelist)) != NULL) { 2357 delta--; 2358 LIST_REMOVE(pt, pt_next); 2359 LIST_INSERT_HEAD(&tmplist, pt, pt_next); 2360 } 2361 mtx_unlock_spin(&pmc_threadfreelist_mtx); 2362 2363 /* If there are entries to free, free them. */ 2364 while (!LIST_EMPTY(&tmplist)) { 2365 pt = LIST_FIRST(&tmplist); 2366 LIST_REMOVE(pt, pt_next); 2367 free(pt, M_PMC); 2368 } 2369 } 2370 2371 /* 2372 * Drain the thread free pool, freeing all allocations. 2373 */ 2374 static void 2375 pmc_thread_descriptor_pool_drain() 2376 { 2377 struct pmc_thread *pt, *next; 2378 2379 LIST_FOREACH_SAFE(pt, &pmc_threadfreelist, pt_next, next) { 2380 LIST_REMOVE(pt, pt_next); 2381 free(pt, M_PMC); 2382 } 2383 } 2384 2385 /* 2386 * find the descriptor corresponding to thread 'td', adding or removing it 2387 * as specified by 'mode'. 2388 * 2389 * Note that this supports additional mode flags in addition to those 2390 * supported by pmc_find_process_descriptor(): 2391 * PMC_FLAG_NOWAIT: Causes the function to not wait for mallocs. 2392 * This makes it safe to call while holding certain other locks. 2393 */ 2394 2395 static struct pmc_thread * 2396 pmc_find_thread_descriptor(struct pmc_process *pp, struct thread *td, 2397 uint32_t mode) 2398 { 2399 struct pmc_thread *pt = NULL, *ptnew = NULL; 2400 int wait_flag; 2401 2402 KASSERT(td != NULL, ("[pmc,%d] called to add NULL td", __LINE__)); 2403 2404 /* 2405 * Pre-allocate memory in the PMC_FLAG_ALLOCATE case prior to 2406 * acquiring the lock. 2407 */ 2408 if (mode & PMC_FLAG_ALLOCATE) { 2409 if ((ptnew = pmc_thread_descriptor_pool_alloc()) == NULL) { 2410 wait_flag = M_WAITOK; 2411 if ((mode & PMC_FLAG_NOWAIT) || in_epoch()) 2412 wait_flag = M_NOWAIT; 2413 2414 ptnew = malloc(THREADENTRY_SIZE, M_PMC, 2415 wait_flag|M_ZERO); 2416 } 2417 } 2418 2419 mtx_lock_spin(pp->pp_tdslock); 2420 2421 LIST_FOREACH(pt, &pp->pp_tds, pt_next) 2422 if (pt->pt_td == td) 2423 break; 2424 2425 if ((mode & PMC_FLAG_REMOVE) && pt != NULL) 2426 LIST_REMOVE(pt, pt_next); 2427 2428 if ((mode & PMC_FLAG_ALLOCATE) && pt == NULL && ptnew != NULL) { 2429 pt = ptnew; 2430 ptnew = NULL; 2431 pt->pt_td = td; 2432 LIST_INSERT_HEAD(&pp->pp_tds, pt, pt_next); 2433 } 2434 2435 mtx_unlock_spin(pp->pp_tdslock); 2436 2437 if (ptnew != NULL) { 2438 free(ptnew, M_PMC); 2439 } 2440 2441 return pt; 2442 } 2443 2444 /* 2445 * Try to add thread descriptors for each thread in a process. 2446 */ 2447 2448 static void 2449 pmc_add_thread_descriptors_from_proc(struct proc *p, struct pmc_process *pp) 2450 { 2451 struct thread *curtd; 2452 struct pmc_thread **tdlist; 2453 int i, tdcnt, tdlistsz; 2454 2455 KASSERT(!PROC_LOCKED(p), ("[pmc,%d] proc unexpectedly locked", 2456 __LINE__)); 2457 tdcnt = 32; 2458 restart: 2459 tdlistsz = roundup2(tdcnt, 32); 2460 2461 tdcnt = 0; 2462 tdlist = malloc(sizeof(struct pmc_thread*) * tdlistsz, M_TEMP, M_WAITOK); 2463 2464 PROC_LOCK(p); 2465 FOREACH_THREAD_IN_PROC(p, curtd) 2466 tdcnt++; 2467 if (tdcnt >= tdlistsz) { 2468 PROC_UNLOCK(p); 2469 free(tdlist, M_TEMP); 2470 goto restart; 2471 } 2472 /* 2473 * Try to add each thread to the list without sleeping. If unable, 2474 * add to a queue to retry after dropping the process lock. 2475 */ 2476 tdcnt = 0; 2477 FOREACH_THREAD_IN_PROC(p, curtd) { 2478 tdlist[tdcnt] = pmc_find_thread_descriptor(pp, curtd, 2479 PMC_FLAG_ALLOCATE|PMC_FLAG_NOWAIT); 2480 if (tdlist[tdcnt] == NULL) { 2481 PROC_UNLOCK(p); 2482 for (i = 0; i <= tdcnt; i++) 2483 pmc_thread_descriptor_pool_free(tdlist[i]); 2484 free(tdlist, M_TEMP); 2485 goto restart; 2486 } 2487 tdcnt++; 2488 } 2489 PROC_UNLOCK(p); 2490 free(tdlist, M_TEMP); 2491 } 2492 2493 /* 2494 * find the descriptor corresponding to process 'p', adding or removing it 2495 * as specified by 'mode'. 2496 */ 2497 2498 static struct pmc_process * 2499 pmc_find_process_descriptor(struct proc *p, uint32_t mode) 2500 { 2501 uint32_t hindex; 2502 struct pmc_process *pp, *ppnew; 2503 struct pmc_processhash *pph; 2504 2505 hindex = PMC_HASH_PTR(p, pmc_processhashmask); 2506 pph = &pmc_processhash[hindex]; 2507 2508 ppnew = NULL; 2509 2510 /* 2511 * Pre-allocate memory in the PMC_FLAG_ALLOCATE case since we 2512 * cannot call malloc(9) once we hold a spin lock. 2513 */ 2514 if (mode & PMC_FLAG_ALLOCATE) 2515 ppnew = malloc(sizeof(struct pmc_process) + md->pmd_npmc * 2516 sizeof(struct pmc_targetstate), M_PMC, M_WAITOK|M_ZERO); 2517 2518 mtx_lock_spin(&pmc_processhash_mtx); 2519 LIST_FOREACH(pp, pph, pp_next) 2520 if (pp->pp_proc == p) 2521 break; 2522 2523 if ((mode & PMC_FLAG_REMOVE) && pp != NULL) 2524 LIST_REMOVE(pp, pp_next); 2525 2526 if ((mode & PMC_FLAG_ALLOCATE) && pp == NULL && 2527 ppnew != NULL) { 2528 ppnew->pp_proc = p; 2529 LIST_INIT(&ppnew->pp_tds); 2530 ppnew->pp_tdslock = mtx_pool_find(pmc_mtxpool, ppnew); 2531 LIST_INSERT_HEAD(pph, ppnew, pp_next); 2532 mtx_unlock_spin(&pmc_processhash_mtx); 2533 pp = ppnew; 2534 ppnew = NULL; 2535 2536 /* Add thread descriptors for this process' current threads. */ 2537 pmc_add_thread_descriptors_from_proc(p, pp); 2538 } 2539 else 2540 mtx_unlock_spin(&pmc_processhash_mtx); 2541 2542 if (ppnew != NULL) 2543 free(ppnew, M_PMC); 2544 2545 return pp; 2546 } 2547 2548 /* 2549 * remove a process descriptor from the process hash table. 2550 */ 2551 2552 static void 2553 pmc_remove_process_descriptor(struct pmc_process *pp) 2554 { 2555 KASSERT(pp->pp_refcnt == 0, 2556 ("[pmc,%d] Removing process descriptor %p with count %d", 2557 __LINE__, pp, pp->pp_refcnt)); 2558 2559 mtx_lock_spin(&pmc_processhash_mtx); 2560 LIST_REMOVE(pp, pp_next); 2561 mtx_unlock_spin(&pmc_processhash_mtx); 2562 } 2563 2564 /* 2565 * destroy a process descriptor. 2566 */ 2567 2568 static void 2569 pmc_destroy_process_descriptor(struct pmc_process *pp) 2570 { 2571 struct pmc_thread *pmc_td; 2572 2573 while ((pmc_td = LIST_FIRST(&pp->pp_tds)) != NULL) { 2574 LIST_REMOVE(pmc_td, pt_next); 2575 pmc_thread_descriptor_pool_free(pmc_td); 2576 } 2577 free(pp, M_PMC); 2578 } 2579 2580 2581 /* 2582 * find an owner descriptor corresponding to proc 'p' 2583 */ 2584 2585 static struct pmc_owner * 2586 pmc_find_owner_descriptor(struct proc *p) 2587 { 2588 uint32_t hindex; 2589 struct pmc_owner *po; 2590 struct pmc_ownerhash *poh; 2591 2592 hindex = PMC_HASH_PTR(p, pmc_ownerhashmask); 2593 poh = &pmc_ownerhash[hindex]; 2594 2595 po = NULL; 2596 LIST_FOREACH(po, poh, po_next) 2597 if (po->po_owner == p) 2598 break; 2599 2600 PMCDBG5(OWN,FND,1, "find-owner proc=%p (%d, %s) hindex=0x%x -> " 2601 "pmc-owner=%p", p, p->p_pid, p->p_comm, hindex, po); 2602 2603 return po; 2604 } 2605 2606 /* 2607 * pmc_allocate_pmc_descriptor 2608 * 2609 * Allocate a pmc descriptor and initialize its 2610 * fields. 2611 */ 2612 2613 static struct pmc * 2614 pmc_allocate_pmc_descriptor(void) 2615 { 2616 struct pmc *pmc; 2617 2618 pmc = malloc(sizeof(struct pmc), M_PMC, M_WAITOK|M_ZERO); 2619 pmc->pm_runcount = counter_u64_alloc(M_WAITOK); 2620 pmc->pm_pcpu_state = malloc(sizeof(struct pmc_pcpu_state)*mp_ncpus, M_PMC, M_WAITOK|M_ZERO); 2621 PMCDBG1(PMC,ALL,1, "allocate-pmc -> pmc=%p", pmc); 2622 2623 return pmc; 2624 } 2625 2626 /* 2627 * Destroy a pmc descriptor. 2628 */ 2629 2630 static void 2631 pmc_destroy_pmc_descriptor(struct pmc *pm) 2632 { 2633 2634 KASSERT(pm->pm_state == PMC_STATE_DELETED || 2635 pm->pm_state == PMC_STATE_FREE, 2636 ("[pmc,%d] destroying non-deleted PMC", __LINE__)); 2637 KASSERT(LIST_EMPTY(&pm->pm_targets), 2638 ("[pmc,%d] destroying pmc with targets", __LINE__)); 2639 KASSERT(pm->pm_owner == NULL, 2640 ("[pmc,%d] destroying pmc attached to an owner", __LINE__)); 2641 KASSERT(counter_u64_fetch(pm->pm_runcount) == 0, 2642 ("[pmc,%d] pmc has non-zero run count %ld", __LINE__, 2643 (unsigned long)counter_u64_fetch(pm->pm_runcount))); 2644 2645 counter_u64_free(pm->pm_runcount); 2646 free(pm->pm_pcpu_state, M_PMC); 2647 free(pm, M_PMC); 2648 } 2649 2650 static void 2651 pmc_wait_for_pmc_idle(struct pmc *pm) 2652 { 2653 #ifdef HWPMC_DEBUG 2654 volatile int maxloop; 2655 2656 maxloop = 100 * pmc_cpu_max(); 2657 #endif 2658 /* 2659 * Loop (with a forced context switch) till the PMC's runcount 2660 * comes down to zero. 2661 */ 2662 while (counter_u64_fetch(pm->pm_runcount) > 0) { 2663 #ifdef HWPMC_DEBUG 2664 maxloop--; 2665 KASSERT(maxloop > 0, 2666 ("[pmc,%d] (ri%d, rc%ld) waiting too long for " 2667 "pmc to be free", __LINE__, 2668 PMC_TO_ROWINDEX(pm), (unsigned long)counter_u64_fetch(pm->pm_runcount))); 2669 #endif 2670 pmc_force_context_switch(); 2671 } 2672 } 2673 2674 /* 2675 * This function does the following things: 2676 * 2677 * - detaches the PMC from hardware 2678 * - unlinks all target threads that were attached to it 2679 * - removes the PMC from its owner's list 2680 * - destroys the PMC private mutex 2681 * 2682 * Once this function completes, the given pmc pointer can be freed by 2683 * calling pmc_destroy_pmc_descriptor(). 2684 */ 2685 2686 static void 2687 pmc_release_pmc_descriptor(struct pmc *pm) 2688 { 2689 enum pmc_mode mode; 2690 struct pmc_hw *phw; 2691 u_int adjri, ri, cpu; 2692 struct pmc_owner *po; 2693 struct pmc_binding pb; 2694 struct pmc_process *pp; 2695 struct pmc_classdep *pcd; 2696 struct pmc_target *ptgt, *tmp; 2697 2698 sx_assert(&pmc_sx, SX_XLOCKED); 2699 2700 KASSERT(pm, ("[pmc,%d] null pmc", __LINE__)); 2701 2702 ri = PMC_TO_ROWINDEX(pm); 2703 pcd = pmc_ri_to_classdep(md, ri, &adjri); 2704 mode = PMC_TO_MODE(pm); 2705 2706 PMCDBG3(PMC,REL,1, "release-pmc pmc=%p ri=%d mode=%d", pm, ri, 2707 mode); 2708 2709 /* 2710 * First, we take the PMC off hardware. 2711 */ 2712 cpu = 0; 2713 if (PMC_IS_SYSTEM_MODE(mode)) { 2714 2715 /* 2716 * A system mode PMC runs on a specific CPU. Switch 2717 * to this CPU and turn hardware off. 2718 */ 2719 pmc_save_cpu_binding(&pb); 2720 2721 cpu = PMC_TO_CPU(pm); 2722 2723 pmc_select_cpu(cpu); 2724 2725 /* switch off non-stalled CPUs */ 2726 pm->pm_pcpu_state[cpu].pps_cpustate = 0; 2727 if (pm->pm_state == PMC_STATE_RUNNING && 2728 pm->pm_pcpu_state[cpu].pps_stalled == 0) { 2729 2730 phw = pmc_pcpu[cpu]->pc_hwpmcs[ri]; 2731 2732 KASSERT(phw->phw_pmc == pm, 2733 ("[pmc, %d] pmc ptr ri(%d) hw(%p) pm(%p)", 2734 __LINE__, ri, phw->phw_pmc, pm)); 2735 PMCDBG2(PMC,REL,2, "stopping cpu=%d ri=%d", cpu, ri); 2736 2737 critical_enter(); 2738 pcd->pcd_stop_pmc(cpu, adjri); 2739 critical_exit(); 2740 } 2741 2742 PMCDBG2(PMC,REL,2, "decfg cpu=%d ri=%d", cpu, ri); 2743 2744 critical_enter(); 2745 pcd->pcd_config_pmc(cpu, adjri, NULL); 2746 critical_exit(); 2747 2748 /* adjust the global and process count of SS mode PMCs */ 2749 if (mode == PMC_MODE_SS && pm->pm_state == PMC_STATE_RUNNING) { 2750 po = pm->pm_owner; 2751 po->po_sscount--; 2752 if (po->po_sscount == 0) { 2753 atomic_subtract_rel_int(&pmc_ss_count, 1); 2754 CK_LIST_REMOVE(po, po_ssnext); 2755 epoch_wait_preempt(global_epoch_preempt); 2756 } 2757 } 2758 2759 pm->pm_state = PMC_STATE_DELETED; 2760 2761 pmc_restore_cpu_binding(&pb); 2762 2763 /* 2764 * We could have references to this PMC structure in 2765 * the per-cpu sample queues. Wait for the queue to 2766 * drain. 2767 */ 2768 pmc_wait_for_pmc_idle(pm); 2769 2770 } else if (PMC_IS_VIRTUAL_MODE(mode)) { 2771 2772 /* 2773 * A virtual PMC could be running on multiple CPUs at 2774 * a given instant. 2775 * 2776 * By marking its state as DELETED, we ensure that 2777 * this PMC is never further scheduled on hardware. 2778 * 2779 * Then we wait till all CPUs are done with this PMC. 2780 */ 2781 pm->pm_state = PMC_STATE_DELETED; 2782 2783 2784 /* Wait for the PMCs runcount to come to zero. */ 2785 pmc_wait_for_pmc_idle(pm); 2786 2787 /* 2788 * At this point the PMC is off all CPUs and cannot be 2789 * freshly scheduled onto a CPU. It is now safe to 2790 * unlink all targets from this PMC. If a 2791 * process-record's refcount falls to zero, we remove 2792 * it from the hash table. The module-wide SX lock 2793 * protects us from races. 2794 */ 2795 LIST_FOREACH_SAFE(ptgt, &pm->pm_targets, pt_next, tmp) { 2796 pp = ptgt->pt_process; 2797 pmc_unlink_target_process(pm, pp); /* frees 'ptgt' */ 2798 2799 PMCDBG1(PMC,REL,3, "pp->refcnt=%d", pp->pp_refcnt); 2800 2801 /* 2802 * If the target process record shows that no 2803 * PMCs are attached to it, reclaim its space. 2804 */ 2805 2806 if (pp->pp_refcnt == 0) { 2807 pmc_remove_process_descriptor(pp); 2808 pmc_destroy_process_descriptor(pp); 2809 } 2810 } 2811 2812 cpu = curthread->td_oncpu; /* setup cpu for pmd_release() */ 2813 2814 } 2815 2816 /* 2817 * Release any MD resources 2818 */ 2819 (void) pcd->pcd_release_pmc(cpu, adjri, pm); 2820 2821 /* 2822 * Update row disposition 2823 */ 2824 2825 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) 2826 PMC_UNMARK_ROW_STANDALONE(ri); 2827 else 2828 PMC_UNMARK_ROW_THREAD(ri); 2829 2830 /* unlink from the owner's list */ 2831 if (pm->pm_owner) { 2832 LIST_REMOVE(pm, pm_next); 2833 pm->pm_owner = NULL; 2834 } 2835 } 2836 2837 /* 2838 * Register an owner and a pmc. 2839 */ 2840 2841 static int 2842 pmc_register_owner(struct proc *p, struct pmc *pmc) 2843 { 2844 struct pmc_owner *po; 2845 2846 sx_assert(&pmc_sx, SX_XLOCKED); 2847 2848 if ((po = pmc_find_owner_descriptor(p)) == NULL) 2849 if ((po = pmc_allocate_owner_descriptor(p)) == NULL) 2850 return ENOMEM; 2851 2852 KASSERT(pmc->pm_owner == NULL, 2853 ("[pmc,%d] attempting to own an initialized PMC", __LINE__)); 2854 pmc->pm_owner = po; 2855 2856 LIST_INSERT_HEAD(&po->po_pmcs, pmc, pm_next); 2857 2858 PROC_LOCK(p); 2859 p->p_flag |= P_HWPMC; 2860 PROC_UNLOCK(p); 2861 2862 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 2863 pmclog_process_pmcallocate(pmc); 2864 2865 PMCDBG2(PMC,REG,1, "register-owner pmc-owner=%p pmc=%p", 2866 po, pmc); 2867 2868 return 0; 2869 } 2870 2871 /* 2872 * Return the current row disposition: 2873 * == 0 => FREE 2874 * > 0 => PROCESS MODE 2875 * < 0 => SYSTEM MODE 2876 */ 2877 2878 int 2879 pmc_getrowdisp(int ri) 2880 { 2881 return pmc_pmcdisp[ri]; 2882 } 2883 2884 /* 2885 * Check if a PMC at row index 'ri' can be allocated to the current 2886 * process. 2887 * 2888 * Allocation can fail if: 2889 * - the current process is already being profiled by a PMC at index 'ri', 2890 * attached to it via OP_PMCATTACH. 2891 * - the current process has already allocated a PMC at index 'ri' 2892 * via OP_ALLOCATE. 2893 */ 2894 2895 static int 2896 pmc_can_allocate_rowindex(struct proc *p, unsigned int ri, int cpu) 2897 { 2898 enum pmc_mode mode; 2899 struct pmc *pm; 2900 struct pmc_owner *po; 2901 struct pmc_process *pp; 2902 2903 PMCDBG5(PMC,ALR,1, "can-allocate-rowindex proc=%p (%d, %s) ri=%d " 2904 "cpu=%d", p, p->p_pid, p->p_comm, ri, cpu); 2905 2906 /* 2907 * We shouldn't have already allocated a process-mode PMC at 2908 * row index 'ri'. 2909 * 2910 * We shouldn't have allocated a system-wide PMC on the same 2911 * CPU and same RI. 2912 */ 2913 if ((po = pmc_find_owner_descriptor(p)) != NULL) 2914 LIST_FOREACH(pm, &po->po_pmcs, pm_next) { 2915 if (PMC_TO_ROWINDEX(pm) == ri) { 2916 mode = PMC_TO_MODE(pm); 2917 if (PMC_IS_VIRTUAL_MODE(mode)) 2918 return EEXIST; 2919 if (PMC_IS_SYSTEM_MODE(mode) && 2920 (int) PMC_TO_CPU(pm) == cpu) 2921 return EEXIST; 2922 } 2923 } 2924 2925 /* 2926 * We also shouldn't be the target of any PMC at this index 2927 * since otherwise a PMC_ATTACH to ourselves will fail. 2928 */ 2929 if ((pp = pmc_find_process_descriptor(p, 0)) != NULL) 2930 if (pp->pp_pmcs[ri].pp_pmc) 2931 return EEXIST; 2932 2933 PMCDBG4(PMC,ALR,2, "can-allocate-rowindex proc=%p (%d, %s) ri=%d ok", 2934 p, p->p_pid, p->p_comm, ri); 2935 2936 return 0; 2937 } 2938 2939 /* 2940 * Check if a given PMC at row index 'ri' can be currently used in 2941 * mode 'mode'. 2942 */ 2943 2944 static int 2945 pmc_can_allocate_row(int ri, enum pmc_mode mode) 2946 { 2947 enum pmc_disp disp; 2948 2949 sx_assert(&pmc_sx, SX_XLOCKED); 2950 2951 PMCDBG2(PMC,ALR,1, "can-allocate-row ri=%d mode=%d", ri, mode); 2952 2953 if (PMC_IS_SYSTEM_MODE(mode)) 2954 disp = PMC_DISP_STANDALONE; 2955 else 2956 disp = PMC_DISP_THREAD; 2957 2958 /* 2959 * check disposition for PMC row 'ri': 2960 * 2961 * Expected disposition Row-disposition Result 2962 * 2963 * STANDALONE STANDALONE or FREE proceed 2964 * STANDALONE THREAD fail 2965 * THREAD THREAD or FREE proceed 2966 * THREAD STANDALONE fail 2967 */ 2968 2969 if (!PMC_ROW_DISP_IS_FREE(ri) && 2970 !(disp == PMC_DISP_THREAD && PMC_ROW_DISP_IS_THREAD(ri)) && 2971 !(disp == PMC_DISP_STANDALONE && PMC_ROW_DISP_IS_STANDALONE(ri))) 2972 return EBUSY; 2973 2974 /* 2975 * All OK 2976 */ 2977 2978 PMCDBG2(PMC,ALR,2, "can-allocate-row ri=%d mode=%d ok", ri, mode); 2979 2980 return 0; 2981 2982 } 2983 2984 /* 2985 * Find a PMC descriptor with user handle 'pmcid' for thread 'td'. 2986 */ 2987 2988 static struct pmc * 2989 pmc_find_pmc_descriptor_in_process(struct pmc_owner *po, pmc_id_t pmcid) 2990 { 2991 struct pmc *pm; 2992 2993 KASSERT(PMC_ID_TO_ROWINDEX(pmcid) < md->pmd_npmc, 2994 ("[pmc,%d] Illegal pmc index %d (max %d)", __LINE__, 2995 PMC_ID_TO_ROWINDEX(pmcid), md->pmd_npmc)); 2996 2997 LIST_FOREACH(pm, &po->po_pmcs, pm_next) 2998 if (pm->pm_id == pmcid) 2999 return pm; 3000 3001 return NULL; 3002 } 3003 3004 static int 3005 pmc_find_pmc(pmc_id_t pmcid, struct pmc **pmc) 3006 { 3007 3008 struct pmc *pm, *opm; 3009 struct pmc_owner *po; 3010 struct pmc_process *pp; 3011 3012 PMCDBG1(PMC,FND,1, "find-pmc id=%d", pmcid); 3013 if (PMC_ID_TO_ROWINDEX(pmcid) >= md->pmd_npmc) 3014 return (EINVAL); 3015 3016 if ((po = pmc_find_owner_descriptor(curthread->td_proc)) == NULL) { 3017 /* 3018 * In case of PMC_F_DESCENDANTS child processes we will not find 3019 * the current process in the owners hash list. Find the owner 3020 * process first and from there lookup the po. 3021 */ 3022 if ((pp = pmc_find_process_descriptor(curthread->td_proc, 3023 PMC_FLAG_NONE)) == NULL) { 3024 return ESRCH; 3025 } else { 3026 opm = pp->pp_pmcs[PMC_ID_TO_ROWINDEX(pmcid)].pp_pmc; 3027 if (opm == NULL) 3028 return ESRCH; 3029 if ((opm->pm_flags & (PMC_F_ATTACHED_TO_OWNER| 3030 PMC_F_DESCENDANTS)) != (PMC_F_ATTACHED_TO_OWNER| 3031 PMC_F_DESCENDANTS)) 3032 return ESRCH; 3033 po = opm->pm_owner; 3034 } 3035 } 3036 3037 if ((pm = pmc_find_pmc_descriptor_in_process(po, pmcid)) == NULL) 3038 return EINVAL; 3039 3040 PMCDBG2(PMC,FND,2, "find-pmc id=%d -> pmc=%p", pmcid, pm); 3041 3042 *pmc = pm; 3043 return 0; 3044 } 3045 3046 /* 3047 * Start a PMC. 3048 */ 3049 3050 static int 3051 pmc_start(struct pmc *pm) 3052 { 3053 enum pmc_mode mode; 3054 struct pmc_owner *po; 3055 struct pmc_binding pb; 3056 struct pmc_classdep *pcd; 3057 int adjri, error, cpu, ri; 3058 3059 KASSERT(pm != NULL, 3060 ("[pmc,%d] null pm", __LINE__)); 3061 3062 mode = PMC_TO_MODE(pm); 3063 ri = PMC_TO_ROWINDEX(pm); 3064 pcd = pmc_ri_to_classdep(md, ri, &adjri); 3065 3066 error = 0; 3067 3068 PMCDBG3(PMC,OPS,1, "start pmc=%p mode=%d ri=%d", pm, mode, ri); 3069 3070 po = pm->pm_owner; 3071 3072 /* 3073 * Disallow PMCSTART if a logfile is required but has not been 3074 * configured yet. 3075 */ 3076 if ((pm->pm_flags & PMC_F_NEEDS_LOGFILE) && 3077 (po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) 3078 return (EDOOFUS); /* programming error */ 3079 3080 /* 3081 * If this is a sampling mode PMC, log mapping information for 3082 * the kernel modules that are currently loaded. 3083 */ 3084 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 3085 pmc_log_kernel_mappings(pm); 3086 3087 if (PMC_IS_VIRTUAL_MODE(mode)) { 3088 3089 /* 3090 * If a PMCATTACH has never been done on this PMC, 3091 * attach it to its owner process. 3092 */ 3093 3094 if (LIST_EMPTY(&pm->pm_targets)) 3095 error = (pm->pm_flags & PMC_F_ATTACH_DONE) ? ESRCH : 3096 pmc_attach_process(po->po_owner, pm); 3097 3098 /* 3099 * If the PMC is attached to its owner, then force a context 3100 * switch to ensure that the MD state gets set correctly. 3101 */ 3102 3103 if (error == 0) { 3104 pm->pm_state = PMC_STATE_RUNNING; 3105 if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) 3106 pmc_force_context_switch(); 3107 } 3108 3109 return (error); 3110 } 3111 3112 3113 /* 3114 * A system-wide PMC. 3115 * 3116 * Add the owner to the global list if this is a system-wide 3117 * sampling PMC. 3118 */ 3119 3120 if (mode == PMC_MODE_SS) { 3121 /* 3122 * Log mapping information for all existing processes in the 3123 * system. Subsequent mappings are logged as they happen; 3124 * see pmc_process_mmap(). 3125 */ 3126 if (po->po_logprocmaps == 0) { 3127 pmc_log_all_process_mappings(po); 3128 po->po_logprocmaps = 1; 3129 } 3130 po->po_sscount++; 3131 if (po->po_sscount == 1) { 3132 atomic_add_rel_int(&pmc_ss_count, 1); 3133 CK_LIST_INSERT_HEAD(&pmc_ss_owners, po, po_ssnext); 3134 PMCDBG1(PMC,OPS,1, "po=%p in global list", po); 3135 } 3136 } 3137 3138 /* 3139 * Move to the CPU associated with this 3140 * PMC, and start the hardware. 3141 */ 3142 3143 pmc_save_cpu_binding(&pb); 3144 3145 cpu = PMC_TO_CPU(pm); 3146 3147 if (!pmc_cpu_is_active(cpu)) 3148 return (ENXIO); 3149 3150 pmc_select_cpu(cpu); 3151 3152 /* 3153 * global PMCs are configured at allocation time 3154 * so write out the initial value and start the PMC. 3155 */ 3156 3157 pm->pm_state = PMC_STATE_RUNNING; 3158 3159 critical_enter(); 3160 if ((error = pcd->pcd_write_pmc(cpu, adjri, 3161 PMC_IS_SAMPLING_MODE(mode) ? 3162 pm->pm_sc.pm_reloadcount : 3163 pm->pm_sc.pm_initial)) == 0) { 3164 /* If a sampling mode PMC, reset stalled state. */ 3165 if (PMC_IS_SAMPLING_MODE(mode)) 3166 pm->pm_pcpu_state[cpu].pps_stalled = 0; 3167 3168 /* Indicate that we desire this to run. Start it. */ 3169 pm->pm_pcpu_state[cpu].pps_cpustate = 1; 3170 error = pcd->pcd_start_pmc(cpu, adjri); 3171 } 3172 critical_exit(); 3173 3174 pmc_restore_cpu_binding(&pb); 3175 3176 return (error); 3177 } 3178 3179 /* 3180 * Stop a PMC. 3181 */ 3182 3183 static int 3184 pmc_stop(struct pmc *pm) 3185 { 3186 struct pmc_owner *po; 3187 struct pmc_binding pb; 3188 struct pmc_classdep *pcd; 3189 int adjri, cpu, error, ri; 3190 3191 KASSERT(pm != NULL, ("[pmc,%d] null pmc", __LINE__)); 3192 3193 PMCDBG3(PMC,OPS,1, "stop pmc=%p mode=%d ri=%d", pm, 3194 PMC_TO_MODE(pm), PMC_TO_ROWINDEX(pm)); 3195 3196 pm->pm_state = PMC_STATE_STOPPED; 3197 3198 /* 3199 * If the PMC is a virtual mode one, changing the state to 3200 * non-RUNNING is enough to ensure that the PMC never gets 3201 * scheduled. 3202 * 3203 * If this PMC is current running on a CPU, then it will 3204 * handled correctly at the time its target process is context 3205 * switched out. 3206 */ 3207 3208 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) 3209 return 0; 3210 3211 /* 3212 * A system-mode PMC. Move to the CPU associated with 3213 * this PMC, and stop the hardware. We update the 3214 * 'initial count' so that a subsequent PMCSTART will 3215 * resume counting from the current hardware count. 3216 */ 3217 3218 pmc_save_cpu_binding(&pb); 3219 3220 cpu = PMC_TO_CPU(pm); 3221 3222 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 3223 ("[pmc,%d] illegal cpu=%d", __LINE__, cpu)); 3224 3225 if (!pmc_cpu_is_active(cpu)) 3226 return ENXIO; 3227 3228 pmc_select_cpu(cpu); 3229 3230 ri = PMC_TO_ROWINDEX(pm); 3231 pcd = pmc_ri_to_classdep(md, ri, &adjri); 3232 3233 pm->pm_pcpu_state[cpu].pps_cpustate = 0; 3234 critical_enter(); 3235 if ((error = pcd->pcd_stop_pmc(cpu, adjri)) == 0) 3236 error = pcd->pcd_read_pmc(cpu, adjri, &pm->pm_sc.pm_initial); 3237 critical_exit(); 3238 3239 pmc_restore_cpu_binding(&pb); 3240 3241 po = pm->pm_owner; 3242 3243 /* remove this owner from the global list of SS PMC owners */ 3244 if (PMC_TO_MODE(pm) == PMC_MODE_SS) { 3245 po->po_sscount--; 3246 if (po->po_sscount == 0) { 3247 atomic_subtract_rel_int(&pmc_ss_count, 1); 3248 CK_LIST_REMOVE(po, po_ssnext); 3249 epoch_wait_preempt(global_epoch_preempt); 3250 PMCDBG1(PMC,OPS,2,"po=%p removed from global list", po); 3251 } 3252 } 3253 3254 return (error); 3255 } 3256 3257 static struct pmc_classdep * 3258 pmc_class_to_classdep(enum pmc_class class) 3259 { 3260 int n; 3261 3262 for (n = 0; n < md->pmd_nclass; n++) 3263 if (md->pmd_classdep[n].pcd_class == class) 3264 return (&md->pmd_classdep[n]); 3265 return (NULL); 3266 } 3267 3268 #ifdef HWPMC_DEBUG 3269 static const char *pmc_op_to_name[] = { 3270 #undef __PMC_OP 3271 #define __PMC_OP(N, D) #N , 3272 __PMC_OPS() 3273 NULL 3274 }; 3275 #endif 3276 3277 /* 3278 * The syscall interface 3279 */ 3280 3281 #define PMC_GET_SX_XLOCK(...) do { \ 3282 sx_xlock(&pmc_sx); \ 3283 if (pmc_hook == NULL) { \ 3284 sx_xunlock(&pmc_sx); \ 3285 return __VA_ARGS__; \ 3286 } \ 3287 } while (0) 3288 3289 #define PMC_DOWNGRADE_SX() do { \ 3290 sx_downgrade(&pmc_sx); \ 3291 is_sx_downgraded = 1; \ 3292 } while (0) 3293 3294 static int 3295 pmc_syscall_handler(struct thread *td, void *syscall_args) 3296 { 3297 int error, is_sx_downgraded, op; 3298 struct pmc_syscall_args *c; 3299 void *pmclog_proc_handle; 3300 void *arg; 3301 3302 c = (struct pmc_syscall_args *)syscall_args; 3303 op = c->pmop_code; 3304 arg = c->pmop_data; 3305 /* PMC isn't set up yet */ 3306 if (pmc_hook == NULL) 3307 return (EINVAL); 3308 if (op == PMC_OP_CONFIGURELOG) { 3309 /* 3310 * We cannot create the logging process inside 3311 * pmclog_configure_log() because there is a LOR 3312 * between pmc_sx and process structure locks. 3313 * Instead, pre-create the process and ignite the loop 3314 * if everything is fine, otherwise direct the process 3315 * to exit. 3316 */ 3317 error = pmclog_proc_create(td, &pmclog_proc_handle); 3318 if (error != 0) 3319 goto done_syscall; 3320 } 3321 3322 PMC_GET_SX_XLOCK(ENOSYS); 3323 is_sx_downgraded = 0; 3324 PMCDBG3(MOD,PMS,1, "syscall op=%d \"%s\" arg=%p", op, 3325 pmc_op_to_name[op], arg); 3326 3327 error = 0; 3328 counter_u64_add(pmc_stats.pm_syscalls, 1); 3329 3330 switch (op) { 3331 3332 3333 /* 3334 * Configure a log file. 3335 * 3336 * XXX This OP will be reworked. 3337 */ 3338 3339 case PMC_OP_CONFIGURELOG: 3340 { 3341 struct proc *p; 3342 struct pmc *pm; 3343 struct pmc_owner *po; 3344 struct pmc_op_configurelog cl; 3345 3346 if ((error = copyin(arg, &cl, sizeof(cl))) != 0) { 3347 pmclog_proc_ignite(pmclog_proc_handle, NULL); 3348 break; 3349 } 3350 3351 /* mark this process as owning a log file */ 3352 p = td->td_proc; 3353 if ((po = pmc_find_owner_descriptor(p)) == NULL) 3354 if ((po = pmc_allocate_owner_descriptor(p)) == NULL) { 3355 pmclog_proc_ignite(pmclog_proc_handle, NULL); 3356 error = ENOMEM; 3357 break; 3358 } 3359 3360 /* 3361 * If a valid fd was passed in, try to configure that, 3362 * otherwise if 'fd' was less than zero and there was 3363 * a log file configured, flush its buffers and 3364 * de-configure it. 3365 */ 3366 if (cl.pm_logfd >= 0) { 3367 error = pmclog_configure_log(md, po, cl.pm_logfd); 3368 pmclog_proc_ignite(pmclog_proc_handle, error == 0 ? 3369 po : NULL); 3370 } else if (po->po_flags & PMC_PO_OWNS_LOGFILE) { 3371 pmclog_proc_ignite(pmclog_proc_handle, NULL); 3372 error = pmclog_close(po); 3373 if (error == 0) { 3374 LIST_FOREACH(pm, &po->po_pmcs, pm_next) 3375 if (pm->pm_flags & PMC_F_NEEDS_LOGFILE && 3376 pm->pm_state == PMC_STATE_RUNNING) 3377 pmc_stop(pm); 3378 error = pmclog_deconfigure_log(po); 3379 } 3380 } else { 3381 pmclog_proc_ignite(pmclog_proc_handle, NULL); 3382 error = EINVAL; 3383 } 3384 } 3385 break; 3386 3387 /* 3388 * Flush a log file. 3389 */ 3390 3391 case PMC_OP_FLUSHLOG: 3392 { 3393 struct pmc_owner *po; 3394 3395 sx_assert(&pmc_sx, SX_XLOCKED); 3396 3397 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 3398 error = EINVAL; 3399 break; 3400 } 3401 3402 error = pmclog_flush(po); 3403 } 3404 break; 3405 3406 /* 3407 * Close a log file. 3408 */ 3409 3410 case PMC_OP_CLOSELOG: 3411 { 3412 struct pmc_owner *po; 3413 3414 sx_assert(&pmc_sx, SX_XLOCKED); 3415 3416 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 3417 error = EINVAL; 3418 break; 3419 } 3420 3421 error = pmclog_close(po); 3422 } 3423 break; 3424 3425 /* 3426 * Retrieve hardware configuration. 3427 */ 3428 3429 case PMC_OP_GETCPUINFO: /* CPU information */ 3430 { 3431 struct pmc_op_getcpuinfo gci; 3432 struct pmc_classinfo *pci; 3433 struct pmc_classdep *pcd; 3434 int cl; 3435 3436 gci.pm_cputype = md->pmd_cputype; 3437 gci.pm_ncpu = pmc_cpu_max(); 3438 gci.pm_npmc = md->pmd_npmc; 3439 gci.pm_nclass = md->pmd_nclass; 3440 pci = gci.pm_classes; 3441 pcd = md->pmd_classdep; 3442 for (cl = 0; cl < md->pmd_nclass; cl++, pci++, pcd++) { 3443 pci->pm_caps = pcd->pcd_caps; 3444 pci->pm_class = pcd->pcd_class; 3445 pci->pm_width = pcd->pcd_width; 3446 pci->pm_num = pcd->pcd_num; 3447 } 3448 error = copyout(&gci, arg, sizeof(gci)); 3449 } 3450 break; 3451 3452 /* 3453 * Retrieve soft events list. 3454 */ 3455 case PMC_OP_GETDYNEVENTINFO: 3456 { 3457 enum pmc_class cl; 3458 enum pmc_event ev; 3459 struct pmc_op_getdyneventinfo *gei; 3460 struct pmc_dyn_event_descr dev; 3461 struct pmc_soft *ps; 3462 uint32_t nevent; 3463 3464 sx_assert(&pmc_sx, SX_LOCKED); 3465 3466 gei = (struct pmc_op_getdyneventinfo *) arg; 3467 3468 if ((error = copyin(&gei->pm_class, &cl, sizeof(cl))) != 0) 3469 break; 3470 3471 /* Only SOFT class is dynamic. */ 3472 if (cl != PMC_CLASS_SOFT) { 3473 error = EINVAL; 3474 break; 3475 } 3476 3477 nevent = 0; 3478 for (ev = PMC_EV_SOFT_FIRST; (int)ev <= PMC_EV_SOFT_LAST; ev++) { 3479 ps = pmc_soft_ev_acquire(ev); 3480 if (ps == NULL) 3481 continue; 3482 bcopy(&ps->ps_ev, &dev, sizeof(dev)); 3483 pmc_soft_ev_release(ps); 3484 3485 error = copyout(&dev, 3486 &gei->pm_events[nevent], 3487 sizeof(struct pmc_dyn_event_descr)); 3488 if (error != 0) 3489 break; 3490 nevent++; 3491 } 3492 if (error != 0) 3493 break; 3494 3495 error = copyout(&nevent, &gei->pm_nevent, 3496 sizeof(nevent)); 3497 } 3498 break; 3499 3500 /* 3501 * Get module statistics 3502 */ 3503 3504 case PMC_OP_GETDRIVERSTATS: 3505 { 3506 struct pmc_op_getdriverstats gms; 3507 #define CFETCH(a, b, field) a.field = counter_u64_fetch(b.field) 3508 CFETCH(gms, pmc_stats, pm_intr_ignored); 3509 CFETCH(gms, pmc_stats, pm_intr_processed); 3510 CFETCH(gms, pmc_stats, pm_intr_bufferfull); 3511 CFETCH(gms, pmc_stats, pm_syscalls); 3512 CFETCH(gms, pmc_stats, pm_syscall_errors); 3513 CFETCH(gms, pmc_stats, pm_buffer_requests); 3514 CFETCH(gms, pmc_stats, pm_buffer_requests_failed); 3515 CFETCH(gms, pmc_stats, pm_log_sweeps); 3516 #undef CFETCH 3517 error = copyout(&gms, arg, sizeof(gms)); 3518 } 3519 break; 3520 3521 3522 /* 3523 * Retrieve module version number 3524 */ 3525 3526 case PMC_OP_GETMODULEVERSION: 3527 { 3528 uint32_t cv, modv; 3529 3530 /* retrieve the client's idea of the ABI version */ 3531 if ((error = copyin(arg, &cv, sizeof(uint32_t))) != 0) 3532 break; 3533 /* don't service clients newer than our driver */ 3534 modv = PMC_VERSION; 3535 if ((cv & 0xFFFF0000) > (modv & 0xFFFF0000)) { 3536 error = EPROGMISMATCH; 3537 break; 3538 } 3539 error = copyout(&modv, arg, sizeof(int)); 3540 } 3541 break; 3542 3543 3544 /* 3545 * Retrieve the state of all the PMCs on a given 3546 * CPU. 3547 */ 3548 3549 case PMC_OP_GETPMCINFO: 3550 { 3551 int ari; 3552 struct pmc *pm; 3553 size_t pmcinfo_size; 3554 uint32_t cpu, n, npmc; 3555 struct pmc_owner *po; 3556 struct pmc_binding pb; 3557 struct pmc_classdep *pcd; 3558 struct pmc_info *p, *pmcinfo; 3559 struct pmc_op_getpmcinfo *gpi; 3560 3561 PMC_DOWNGRADE_SX(); 3562 3563 gpi = (struct pmc_op_getpmcinfo *) arg; 3564 3565 if ((error = copyin(&gpi->pm_cpu, &cpu, sizeof(cpu))) != 0) 3566 break; 3567 3568 if (cpu >= pmc_cpu_max()) { 3569 error = EINVAL; 3570 break; 3571 } 3572 3573 if (!pmc_cpu_is_active(cpu)) { 3574 error = ENXIO; 3575 break; 3576 } 3577 3578 /* switch to CPU 'cpu' */ 3579 pmc_save_cpu_binding(&pb); 3580 pmc_select_cpu(cpu); 3581 3582 npmc = md->pmd_npmc; 3583 3584 pmcinfo_size = npmc * sizeof(struct pmc_info); 3585 pmcinfo = malloc(pmcinfo_size, M_PMC, M_WAITOK); 3586 3587 p = pmcinfo; 3588 3589 for (n = 0; n < md->pmd_npmc; n++, p++) { 3590 3591 pcd = pmc_ri_to_classdep(md, n, &ari); 3592 3593 KASSERT(pcd != NULL, 3594 ("[pmc,%d] null pcd ri=%d", __LINE__, n)); 3595 3596 if ((error = pcd->pcd_describe(cpu, ari, p, &pm)) != 0) 3597 break; 3598 3599 if (PMC_ROW_DISP_IS_STANDALONE(n)) 3600 p->pm_rowdisp = PMC_DISP_STANDALONE; 3601 else if (PMC_ROW_DISP_IS_THREAD(n)) 3602 p->pm_rowdisp = PMC_DISP_THREAD; 3603 else 3604 p->pm_rowdisp = PMC_DISP_FREE; 3605 3606 p->pm_ownerpid = -1; 3607 3608 if (pm == NULL) /* no PMC associated */ 3609 continue; 3610 3611 po = pm->pm_owner; 3612 3613 KASSERT(po->po_owner != NULL, 3614 ("[pmc,%d] pmc_owner had a null proc pointer", 3615 __LINE__)); 3616 3617 p->pm_ownerpid = po->po_owner->p_pid; 3618 p->pm_mode = PMC_TO_MODE(pm); 3619 p->pm_event = pm->pm_event; 3620 p->pm_flags = pm->pm_flags; 3621 3622 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 3623 p->pm_reloadcount = 3624 pm->pm_sc.pm_reloadcount; 3625 } 3626 3627 pmc_restore_cpu_binding(&pb); 3628 3629 /* now copy out the PMC info collected */ 3630 if (error == 0) 3631 error = copyout(pmcinfo, &gpi->pm_pmcs, pmcinfo_size); 3632 3633 free(pmcinfo, M_PMC); 3634 } 3635 break; 3636 3637 3638 /* 3639 * Set the administrative state of a PMC. I.e. whether 3640 * the PMC is to be used or not. 3641 */ 3642 3643 case PMC_OP_PMCADMIN: 3644 { 3645 int cpu, ri; 3646 enum pmc_state request; 3647 struct pmc_cpu *pc; 3648 struct pmc_hw *phw; 3649 struct pmc_op_pmcadmin pma; 3650 struct pmc_binding pb; 3651 3652 sx_assert(&pmc_sx, SX_XLOCKED); 3653 3654 KASSERT(td == curthread, 3655 ("[pmc,%d] td != curthread", __LINE__)); 3656 3657 error = priv_check(td, PRIV_PMC_MANAGE); 3658 if (error) 3659 break; 3660 3661 if ((error = copyin(arg, &pma, sizeof(pma))) != 0) 3662 break; 3663 3664 cpu = pma.pm_cpu; 3665 3666 if (cpu < 0 || cpu >= (int) pmc_cpu_max()) { 3667 error = EINVAL; 3668 break; 3669 } 3670 3671 if (!pmc_cpu_is_active(cpu)) { 3672 error = ENXIO; 3673 break; 3674 } 3675 3676 request = pma.pm_state; 3677 3678 if (request != PMC_STATE_DISABLED && 3679 request != PMC_STATE_FREE) { 3680 error = EINVAL; 3681 break; 3682 } 3683 3684 ri = pma.pm_pmc; /* pmc id == row index */ 3685 if (ri < 0 || ri >= (int) md->pmd_npmc) { 3686 error = EINVAL; 3687 break; 3688 } 3689 3690 /* 3691 * We can't disable a PMC with a row-index allocated 3692 * for process virtual PMCs. 3693 */ 3694 3695 if (PMC_ROW_DISP_IS_THREAD(ri) && 3696 request == PMC_STATE_DISABLED) { 3697 error = EBUSY; 3698 break; 3699 } 3700 3701 /* 3702 * otherwise, this PMC on this CPU is either free or 3703 * in system-wide mode. 3704 */ 3705 3706 pmc_save_cpu_binding(&pb); 3707 pmc_select_cpu(cpu); 3708 3709 pc = pmc_pcpu[cpu]; 3710 phw = pc->pc_hwpmcs[ri]; 3711 3712 /* 3713 * XXX do we need some kind of 'forced' disable? 3714 */ 3715 3716 if (phw->phw_pmc == NULL) { 3717 if (request == PMC_STATE_DISABLED && 3718 (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED)) { 3719 phw->phw_state &= ~PMC_PHW_FLAG_IS_ENABLED; 3720 PMC_MARK_ROW_STANDALONE(ri); 3721 } else if (request == PMC_STATE_FREE && 3722 (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0) { 3723 phw->phw_state |= PMC_PHW_FLAG_IS_ENABLED; 3724 PMC_UNMARK_ROW_STANDALONE(ri); 3725 } 3726 /* other cases are a no-op */ 3727 } else 3728 error = EBUSY; 3729 3730 pmc_restore_cpu_binding(&pb); 3731 } 3732 break; 3733 3734 3735 /* 3736 * Allocate a PMC. 3737 */ 3738 3739 case PMC_OP_PMCALLOCATE: 3740 { 3741 int adjri, n; 3742 u_int cpu; 3743 uint32_t caps; 3744 struct pmc *pmc; 3745 enum pmc_mode mode; 3746 struct pmc_hw *phw; 3747 struct pmc_binding pb; 3748 struct pmc_classdep *pcd; 3749 struct pmc_op_pmcallocate pa; 3750 3751 if ((error = copyin(arg, &pa, sizeof(pa))) != 0) 3752 break; 3753 3754 caps = pa.pm_caps; 3755 mode = pa.pm_mode; 3756 cpu = pa.pm_cpu; 3757 3758 if ((mode != PMC_MODE_SS && mode != PMC_MODE_SC && 3759 mode != PMC_MODE_TS && mode != PMC_MODE_TC) || 3760 (cpu != (u_int) PMC_CPU_ANY && cpu >= pmc_cpu_max())) { 3761 error = EINVAL; 3762 break; 3763 } 3764 3765 /* 3766 * Virtual PMCs should only ask for a default CPU. 3767 * System mode PMCs need to specify a non-default CPU. 3768 */ 3769 3770 if ((PMC_IS_VIRTUAL_MODE(mode) && cpu != (u_int) PMC_CPU_ANY) || 3771 (PMC_IS_SYSTEM_MODE(mode) && cpu == (u_int) PMC_CPU_ANY)) { 3772 error = EINVAL; 3773 break; 3774 } 3775 3776 /* 3777 * Check that an inactive CPU is not being asked for. 3778 */ 3779 3780 if (PMC_IS_SYSTEM_MODE(mode) && !pmc_cpu_is_active(cpu)) { 3781 error = ENXIO; 3782 break; 3783 } 3784 3785 /* 3786 * Refuse an allocation for a system-wide PMC if this 3787 * process has been jailed, or if this process lacks 3788 * super-user credentials and the sysctl tunable 3789 * 'security.bsd.unprivileged_syspmcs' is zero. 3790 */ 3791 3792 if (PMC_IS_SYSTEM_MODE(mode)) { 3793 if (jailed(curthread->td_ucred)) { 3794 error = EPERM; 3795 break; 3796 } 3797 if (!pmc_unprivileged_syspmcs) { 3798 error = priv_check(curthread, 3799 PRIV_PMC_SYSTEM); 3800 if (error) 3801 break; 3802 } 3803 } 3804 3805 /* 3806 * Look for valid values for 'pm_flags' 3807 */ 3808 3809 if ((pa.pm_flags & ~(PMC_F_DESCENDANTS | PMC_F_LOG_PROCCSW | 3810 PMC_F_LOG_PROCEXIT | PMC_F_CALLCHAIN)) != 0) { 3811 error = EINVAL; 3812 break; 3813 } 3814 3815 /* process logging options are not allowed for system PMCs */ 3816 if (PMC_IS_SYSTEM_MODE(mode) && (pa.pm_flags & 3817 (PMC_F_LOG_PROCCSW | PMC_F_LOG_PROCEXIT))) { 3818 error = EINVAL; 3819 break; 3820 } 3821 3822 /* 3823 * All sampling mode PMCs need to be able to interrupt the 3824 * CPU. 3825 */ 3826 if (PMC_IS_SAMPLING_MODE(mode)) 3827 caps |= PMC_CAP_INTERRUPT; 3828 3829 /* A valid class specifier should have been passed in. */ 3830 pcd = pmc_class_to_classdep(pa.pm_class); 3831 if (pcd == NULL) { 3832 error = EINVAL; 3833 break; 3834 } 3835 3836 /* The requested PMC capabilities should be feasible. */ 3837 if ((pcd->pcd_caps & caps) != caps) { 3838 error = EOPNOTSUPP; 3839 break; 3840 } 3841 3842 PMCDBG4(PMC,ALL,2, "event=%d caps=0x%x mode=%d cpu=%d", 3843 pa.pm_ev, caps, mode, cpu); 3844 3845 pmc = pmc_allocate_pmc_descriptor(); 3846 pmc->pm_id = PMC_ID_MAKE_ID(cpu,pa.pm_mode,pa.pm_class, 3847 PMC_ID_INVALID); 3848 pmc->pm_event = pa.pm_ev; 3849 pmc->pm_state = PMC_STATE_FREE; 3850 pmc->pm_caps = caps; 3851 pmc->pm_flags = pa.pm_flags; 3852 3853 /* switch thread to CPU 'cpu' */ 3854 pmc_save_cpu_binding(&pb); 3855 3856 #define PMC_IS_SHAREABLE_PMC(cpu, n) \ 3857 (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_state & \ 3858 PMC_PHW_FLAG_IS_SHAREABLE) 3859 #define PMC_IS_UNALLOCATED(cpu, n) \ 3860 (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_pmc == NULL) 3861 3862 if (PMC_IS_SYSTEM_MODE(mode)) { 3863 pmc_select_cpu(cpu); 3864 for (n = pcd->pcd_ri; n < (int) md->pmd_npmc; n++) { 3865 pcd = pmc_ri_to_classdep(md, n, &adjri); 3866 if (pmc_can_allocate_row(n, mode) == 0 && 3867 pmc_can_allocate_rowindex( 3868 curthread->td_proc, n, cpu) == 0 && 3869 (PMC_IS_UNALLOCATED(cpu, n) || 3870 PMC_IS_SHAREABLE_PMC(cpu, n)) && 3871 pcd->pcd_allocate_pmc(cpu, adjri, pmc, 3872 &pa) == 0) 3873 break; 3874 } 3875 } else { 3876 /* Process virtual mode */ 3877 for (n = pcd->pcd_ri; n < (int) md->pmd_npmc; n++) { 3878 pcd = pmc_ri_to_classdep(md, n, &adjri); 3879 if (pmc_can_allocate_row(n, mode) == 0 && 3880 pmc_can_allocate_rowindex( 3881 curthread->td_proc, n, 3882 PMC_CPU_ANY) == 0 && 3883 pcd->pcd_allocate_pmc(curthread->td_oncpu, 3884 adjri, pmc, &pa) == 0) 3885 break; 3886 } 3887 } 3888 3889 #undef PMC_IS_UNALLOCATED 3890 #undef PMC_IS_SHAREABLE_PMC 3891 3892 pmc_restore_cpu_binding(&pb); 3893 3894 if (n == (int) md->pmd_npmc) { 3895 pmc_destroy_pmc_descriptor(pmc); 3896 pmc = NULL; 3897 error = EINVAL; 3898 break; 3899 } 3900 3901 /* Fill in the correct value in the ID field */ 3902 pmc->pm_id = PMC_ID_MAKE_ID(cpu,mode,pa.pm_class,n); 3903 3904 PMCDBG5(PMC,ALL,2, "ev=%d class=%d mode=%d n=%d -> pmcid=%x", 3905 pmc->pm_event, pa.pm_class, mode, n, pmc->pm_id); 3906 3907 /* Process mode PMCs with logging enabled need log files */ 3908 if (pmc->pm_flags & (PMC_F_LOG_PROCEXIT | PMC_F_LOG_PROCCSW)) 3909 pmc->pm_flags |= PMC_F_NEEDS_LOGFILE; 3910 3911 /* All system mode sampling PMCs require a log file */ 3912 if (PMC_IS_SAMPLING_MODE(mode) && PMC_IS_SYSTEM_MODE(mode)) 3913 pmc->pm_flags |= PMC_F_NEEDS_LOGFILE; 3914 3915 /* 3916 * Configure global pmc's immediately 3917 */ 3918 3919 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pmc))) { 3920 3921 pmc_save_cpu_binding(&pb); 3922 pmc_select_cpu(cpu); 3923 3924 phw = pmc_pcpu[cpu]->pc_hwpmcs[n]; 3925 pcd = pmc_ri_to_classdep(md, n, &adjri); 3926 3927 if ((phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0 || 3928 (error = pcd->pcd_config_pmc(cpu, adjri, pmc)) != 0) { 3929 (void) pcd->pcd_release_pmc(cpu, adjri, pmc); 3930 pmc_destroy_pmc_descriptor(pmc); 3931 pmc = NULL; 3932 pmc_restore_cpu_binding(&pb); 3933 error = EPERM; 3934 break; 3935 } 3936 3937 pmc_restore_cpu_binding(&pb); 3938 } 3939 3940 pmc->pm_state = PMC_STATE_ALLOCATED; 3941 pmc->pm_class = pa.pm_class; 3942 3943 /* 3944 * mark row disposition 3945 */ 3946 3947 if (PMC_IS_SYSTEM_MODE(mode)) 3948 PMC_MARK_ROW_STANDALONE(n); 3949 else 3950 PMC_MARK_ROW_THREAD(n); 3951 3952 /* 3953 * Register this PMC with the current thread as its owner. 3954 */ 3955 3956 if ((error = 3957 pmc_register_owner(curthread->td_proc, pmc)) != 0) { 3958 pmc_release_pmc_descriptor(pmc); 3959 pmc_destroy_pmc_descriptor(pmc); 3960 pmc = NULL; 3961 break; 3962 } 3963 3964 /* 3965 * Return the allocated index. 3966 */ 3967 3968 pa.pm_pmcid = pmc->pm_id; 3969 3970 error = copyout(&pa, arg, sizeof(pa)); 3971 } 3972 break; 3973 3974 3975 /* 3976 * Attach a PMC to a process. 3977 */ 3978 3979 case PMC_OP_PMCATTACH: 3980 { 3981 struct pmc *pm; 3982 struct proc *p; 3983 struct pmc_op_pmcattach a; 3984 3985 sx_assert(&pmc_sx, SX_XLOCKED); 3986 3987 if ((error = copyin(arg, &a, sizeof(a))) != 0) 3988 break; 3989 3990 if (a.pm_pid < 0) { 3991 error = EINVAL; 3992 break; 3993 } else if (a.pm_pid == 0) 3994 a.pm_pid = td->td_proc->p_pid; 3995 3996 if ((error = pmc_find_pmc(a.pm_pmc, &pm)) != 0) 3997 break; 3998 3999 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) { 4000 error = EINVAL; 4001 break; 4002 } 4003 4004 /* PMCs may be (re)attached only when allocated or stopped */ 4005 if (pm->pm_state == PMC_STATE_RUNNING) { 4006 error = EBUSY; 4007 break; 4008 } else if (pm->pm_state != PMC_STATE_ALLOCATED && 4009 pm->pm_state != PMC_STATE_STOPPED) { 4010 error = EINVAL; 4011 break; 4012 } 4013 4014 /* lookup pid */ 4015 if ((p = pfind(a.pm_pid)) == NULL) { 4016 error = ESRCH; 4017 break; 4018 } 4019 4020 /* 4021 * Ignore processes that are working on exiting. 4022 */ 4023 if (p->p_flag & P_WEXIT) { 4024 error = ESRCH; 4025 PROC_UNLOCK(p); /* pfind() returns a locked process */ 4026 break; 4027 } 4028 4029 /* 4030 * we are allowed to attach a PMC to a process if 4031 * we can debug it. 4032 */ 4033 error = p_candebug(curthread, p); 4034 4035 PROC_UNLOCK(p); 4036 4037 if (error == 0) 4038 error = pmc_attach_process(p, pm); 4039 } 4040 break; 4041 4042 4043 /* 4044 * Detach an attached PMC from a process. 4045 */ 4046 4047 case PMC_OP_PMCDETACH: 4048 { 4049 struct pmc *pm; 4050 struct proc *p; 4051 struct pmc_op_pmcattach a; 4052 4053 if ((error = copyin(arg, &a, sizeof(a))) != 0) 4054 break; 4055 4056 if (a.pm_pid < 0) { 4057 error = EINVAL; 4058 break; 4059 } else if (a.pm_pid == 0) 4060 a.pm_pid = td->td_proc->p_pid; 4061 4062 if ((error = pmc_find_pmc(a.pm_pmc, &pm)) != 0) 4063 break; 4064 4065 if ((p = pfind(a.pm_pid)) == NULL) { 4066 error = ESRCH; 4067 break; 4068 } 4069 4070 /* 4071 * Treat processes that are in the process of exiting 4072 * as if they were not present. 4073 */ 4074 4075 if (p->p_flag & P_WEXIT) 4076 error = ESRCH; 4077 4078 PROC_UNLOCK(p); /* pfind() returns a locked process */ 4079 4080 if (error == 0) 4081 error = pmc_detach_process(p, pm); 4082 } 4083 break; 4084 4085 4086 /* 4087 * Retrieve the MSR number associated with the counter 4088 * 'pmc_id'. This allows processes to directly use RDPMC 4089 * instructions to read their PMCs, without the overhead of a 4090 * system call. 4091 */ 4092 4093 case PMC_OP_PMCGETMSR: 4094 { 4095 int adjri, ri; 4096 struct pmc *pm; 4097 struct pmc_target *pt; 4098 struct pmc_op_getmsr gm; 4099 struct pmc_classdep *pcd; 4100 4101 PMC_DOWNGRADE_SX(); 4102 4103 if ((error = copyin(arg, &gm, sizeof(gm))) != 0) 4104 break; 4105 4106 if ((error = pmc_find_pmc(gm.pm_pmcid, &pm)) != 0) 4107 break; 4108 4109 /* 4110 * The allocated PMC has to be a process virtual PMC, 4111 * i.e., of type MODE_T[CS]. Global PMCs can only be 4112 * read using the PMCREAD operation since they may be 4113 * allocated on a different CPU than the one we could 4114 * be running on at the time of the RDPMC instruction. 4115 * 4116 * The GETMSR operation is not allowed for PMCs that 4117 * are inherited across processes. 4118 */ 4119 4120 if (!PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)) || 4121 (pm->pm_flags & PMC_F_DESCENDANTS)) { 4122 error = EINVAL; 4123 break; 4124 } 4125 4126 /* 4127 * It only makes sense to use a RDPMC (or its 4128 * equivalent instruction on non-x86 architectures) on 4129 * a process that has allocated and attached a PMC to 4130 * itself. Conversely the PMC is only allowed to have 4131 * one process attached to it -- its owner. 4132 */ 4133 4134 if ((pt = LIST_FIRST(&pm->pm_targets)) == NULL || 4135 LIST_NEXT(pt, pt_next) != NULL || 4136 pt->pt_process->pp_proc != pm->pm_owner->po_owner) { 4137 error = EINVAL; 4138 break; 4139 } 4140 4141 ri = PMC_TO_ROWINDEX(pm); 4142 pcd = pmc_ri_to_classdep(md, ri, &adjri); 4143 4144 /* PMC class has no 'GETMSR' support */ 4145 if (pcd->pcd_get_msr == NULL) { 4146 error = ENOSYS; 4147 break; 4148 } 4149 4150 if ((error = (*pcd->pcd_get_msr)(adjri, &gm.pm_msr)) < 0) 4151 break; 4152 4153 if ((error = copyout(&gm, arg, sizeof(gm))) < 0) 4154 break; 4155 4156 /* 4157 * Mark our process as using MSRs. Update machine 4158 * state using a forced context switch. 4159 */ 4160 4161 pt->pt_process->pp_flags |= PMC_PP_ENABLE_MSR_ACCESS; 4162 pmc_force_context_switch(); 4163 4164 } 4165 break; 4166 4167 /* 4168 * Release an allocated PMC 4169 */ 4170 4171 case PMC_OP_PMCRELEASE: 4172 { 4173 pmc_id_t pmcid; 4174 struct pmc *pm; 4175 struct pmc_owner *po; 4176 struct pmc_op_simple sp; 4177 4178 /* 4179 * Find PMC pointer for the named PMC. 4180 * 4181 * Use pmc_release_pmc_descriptor() to switch off the 4182 * PMC, remove all its target threads, and remove the 4183 * PMC from its owner's list. 4184 * 4185 * Remove the owner record if this is the last PMC 4186 * owned. 4187 * 4188 * Free up space. 4189 */ 4190 4191 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 4192 break; 4193 4194 pmcid = sp.pm_pmcid; 4195 4196 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 4197 break; 4198 4199 po = pm->pm_owner; 4200 pmc_release_pmc_descriptor(pm); 4201 pmc_maybe_remove_owner(po); 4202 pmc_destroy_pmc_descriptor(pm); 4203 } 4204 break; 4205 4206 4207 /* 4208 * Read and/or write a PMC. 4209 */ 4210 4211 case PMC_OP_PMCRW: 4212 { 4213 int adjri; 4214 struct pmc *pm; 4215 uint32_t cpu, ri; 4216 pmc_value_t oldvalue; 4217 struct pmc_binding pb; 4218 struct pmc_op_pmcrw prw; 4219 struct pmc_classdep *pcd; 4220 struct pmc_op_pmcrw *pprw; 4221 4222 PMC_DOWNGRADE_SX(); 4223 4224 if ((error = copyin(arg, &prw, sizeof(prw))) != 0) 4225 break; 4226 4227 ri = 0; 4228 PMCDBG2(PMC,OPS,1, "rw id=%d flags=0x%x", prw.pm_pmcid, 4229 prw.pm_flags); 4230 4231 /* must have at least one flag set */ 4232 if ((prw.pm_flags & (PMC_F_OLDVALUE|PMC_F_NEWVALUE)) == 0) { 4233 error = EINVAL; 4234 break; 4235 } 4236 4237 /* locate pmc descriptor */ 4238 if ((error = pmc_find_pmc(prw.pm_pmcid, &pm)) != 0) 4239 break; 4240 4241 /* Can't read a PMC that hasn't been started. */ 4242 if (pm->pm_state != PMC_STATE_ALLOCATED && 4243 pm->pm_state != PMC_STATE_STOPPED && 4244 pm->pm_state != PMC_STATE_RUNNING) { 4245 error = EINVAL; 4246 break; 4247 } 4248 4249 /* writing a new value is allowed only for 'STOPPED' pmcs */ 4250 if (pm->pm_state == PMC_STATE_RUNNING && 4251 (prw.pm_flags & PMC_F_NEWVALUE)) { 4252 error = EBUSY; 4253 break; 4254 } 4255 4256 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) { 4257 4258 /* 4259 * If this PMC is attached to its owner (i.e., 4260 * the process requesting this operation) and 4261 * is running, then attempt to get an 4262 * upto-date reading from hardware for a READ. 4263 * Writes are only allowed when the PMC is 4264 * stopped, so only update the saved value 4265 * field. 4266 * 4267 * If the PMC is not running, or is not 4268 * attached to its owner, read/write to the 4269 * savedvalue field. 4270 */ 4271 4272 ri = PMC_TO_ROWINDEX(pm); 4273 pcd = pmc_ri_to_classdep(md, ri, &adjri); 4274 4275 mtx_pool_lock_spin(pmc_mtxpool, pm); 4276 cpu = curthread->td_oncpu; 4277 4278 if (prw.pm_flags & PMC_F_OLDVALUE) { 4279 if ((pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) && 4280 (pm->pm_state == PMC_STATE_RUNNING)) 4281 error = (*pcd->pcd_read_pmc)(cpu, adjri, 4282 &oldvalue); 4283 else 4284 oldvalue = pm->pm_gv.pm_savedvalue; 4285 } 4286 if (prw.pm_flags & PMC_F_NEWVALUE) 4287 pm->pm_gv.pm_savedvalue = prw.pm_value; 4288 4289 mtx_pool_unlock_spin(pmc_mtxpool, pm); 4290 4291 } else { /* System mode PMCs */ 4292 cpu = PMC_TO_CPU(pm); 4293 ri = PMC_TO_ROWINDEX(pm); 4294 pcd = pmc_ri_to_classdep(md, ri, &adjri); 4295 4296 if (!pmc_cpu_is_active(cpu)) { 4297 error = ENXIO; 4298 break; 4299 } 4300 4301 /* move this thread to CPU 'cpu' */ 4302 pmc_save_cpu_binding(&pb); 4303 pmc_select_cpu(cpu); 4304 4305 critical_enter(); 4306 /* save old value */ 4307 if (prw.pm_flags & PMC_F_OLDVALUE) 4308 if ((error = (*pcd->pcd_read_pmc)(cpu, adjri, 4309 &oldvalue))) 4310 goto error; 4311 /* write out new value */ 4312 if (prw.pm_flags & PMC_F_NEWVALUE) 4313 error = (*pcd->pcd_write_pmc)(cpu, adjri, 4314 prw.pm_value); 4315 error: 4316 critical_exit(); 4317 pmc_restore_cpu_binding(&pb); 4318 if (error) 4319 break; 4320 } 4321 4322 pprw = (struct pmc_op_pmcrw *) arg; 4323 4324 #ifdef HWPMC_DEBUG 4325 if (prw.pm_flags & PMC_F_NEWVALUE) 4326 PMCDBG3(PMC,OPS,2, "rw id=%d new %jx -> old %jx", 4327 ri, prw.pm_value, oldvalue); 4328 else if (prw.pm_flags & PMC_F_OLDVALUE) 4329 PMCDBG2(PMC,OPS,2, "rw id=%d -> old %jx", ri, oldvalue); 4330 #endif 4331 4332 /* return old value if requested */ 4333 if (prw.pm_flags & PMC_F_OLDVALUE) 4334 if ((error = copyout(&oldvalue, &pprw->pm_value, 4335 sizeof(prw.pm_value)))) 4336 break; 4337 4338 } 4339 break; 4340 4341 4342 /* 4343 * Set the sampling rate for a sampling mode PMC and the 4344 * initial count for a counting mode PMC. 4345 */ 4346 4347 case PMC_OP_PMCSETCOUNT: 4348 { 4349 struct pmc *pm; 4350 struct pmc_op_pmcsetcount sc; 4351 4352 PMC_DOWNGRADE_SX(); 4353 4354 if ((error = copyin(arg, &sc, sizeof(sc))) != 0) 4355 break; 4356 4357 if ((error = pmc_find_pmc(sc.pm_pmcid, &pm)) != 0) 4358 break; 4359 4360 if (pm->pm_state == PMC_STATE_RUNNING) { 4361 error = EBUSY; 4362 break; 4363 } 4364 4365 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 4366 pm->pm_sc.pm_reloadcount = sc.pm_count; 4367 else 4368 pm->pm_sc.pm_initial = sc.pm_count; 4369 } 4370 break; 4371 4372 4373 /* 4374 * Start a PMC. 4375 */ 4376 4377 case PMC_OP_PMCSTART: 4378 { 4379 pmc_id_t pmcid; 4380 struct pmc *pm; 4381 struct pmc_op_simple sp; 4382 4383 sx_assert(&pmc_sx, SX_XLOCKED); 4384 4385 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 4386 break; 4387 4388 pmcid = sp.pm_pmcid; 4389 4390 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 4391 break; 4392 4393 KASSERT(pmcid == pm->pm_id, 4394 ("[pmc,%d] pmcid %x != id %x", __LINE__, 4395 pm->pm_id, pmcid)); 4396 4397 if (pm->pm_state == PMC_STATE_RUNNING) /* already running */ 4398 break; 4399 else if (pm->pm_state != PMC_STATE_STOPPED && 4400 pm->pm_state != PMC_STATE_ALLOCATED) { 4401 error = EINVAL; 4402 break; 4403 } 4404 4405 error = pmc_start(pm); 4406 } 4407 break; 4408 4409 4410 /* 4411 * Stop a PMC. 4412 */ 4413 4414 case PMC_OP_PMCSTOP: 4415 { 4416 pmc_id_t pmcid; 4417 struct pmc *pm; 4418 struct pmc_op_simple sp; 4419 4420 PMC_DOWNGRADE_SX(); 4421 4422 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 4423 break; 4424 4425 pmcid = sp.pm_pmcid; 4426 4427 /* 4428 * Mark the PMC as inactive and invoke the MD stop 4429 * routines if needed. 4430 */ 4431 4432 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 4433 break; 4434 4435 KASSERT(pmcid == pm->pm_id, 4436 ("[pmc,%d] pmc id %x != pmcid %x", __LINE__, 4437 pm->pm_id, pmcid)); 4438 4439 if (pm->pm_state == PMC_STATE_STOPPED) /* already stopped */ 4440 break; 4441 else if (pm->pm_state != PMC_STATE_RUNNING) { 4442 error = EINVAL; 4443 break; 4444 } 4445 4446 error = pmc_stop(pm); 4447 } 4448 break; 4449 4450 4451 /* 4452 * Write a user supplied value to the log file. 4453 */ 4454 4455 case PMC_OP_WRITELOG: 4456 { 4457 struct pmc_op_writelog wl; 4458 struct pmc_owner *po; 4459 4460 PMC_DOWNGRADE_SX(); 4461 4462 if ((error = copyin(arg, &wl, sizeof(wl))) != 0) 4463 break; 4464 4465 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 4466 error = EINVAL; 4467 break; 4468 } 4469 4470 if ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) { 4471 error = EINVAL; 4472 break; 4473 } 4474 4475 error = pmclog_process_userlog(po, &wl); 4476 } 4477 break; 4478 4479 4480 default: 4481 error = EINVAL; 4482 break; 4483 } 4484 4485 if (is_sx_downgraded) 4486 sx_sunlock(&pmc_sx); 4487 else 4488 sx_xunlock(&pmc_sx); 4489 done_syscall: 4490 if (error) 4491 counter_u64_add(pmc_stats.pm_syscall_errors, 1); 4492 4493 return (error); 4494 } 4495 4496 /* 4497 * Helper functions 4498 */ 4499 4500 4501 /* 4502 * Mark the thread as needing callchain capture and post an AST. The 4503 * actual callchain capture will be done in a context where it is safe 4504 * to take page faults. 4505 */ 4506 4507 static void 4508 pmc_post_callchain_callback(void) 4509 { 4510 struct thread *td; 4511 4512 td = curthread; 4513 4514 /* 4515 * If there is multiple PMCs for the same interrupt ignore new post 4516 */ 4517 if (td->td_pflags & TDP_CALLCHAIN) 4518 return; 4519 4520 /* 4521 * Mark this thread as needing callchain capture. 4522 * `td->td_pflags' will be safe to touch because this thread 4523 * was in user space when it was interrupted. 4524 */ 4525 td->td_pflags |= TDP_CALLCHAIN; 4526 4527 /* 4528 * Don't let this thread migrate between CPUs until callchain 4529 * capture completes. 4530 */ 4531 sched_pin(); 4532 4533 return; 4534 } 4535 4536 /* 4537 * Interrupt processing. 4538 * 4539 * Find a free slot in the per-cpu array of samples and capture the 4540 * current callchain there. If a sample was successfully added, a bit 4541 * is set in mask 'pmc_cpumask' denoting that the DO_SAMPLES hook 4542 * needs to be invoked from the clock handler. 4543 * 4544 * This function is meant to be called from an NMI handler. It cannot 4545 * use any of the locking primitives supplied by the OS. 4546 */ 4547 4548 int 4549 pmc_process_interrupt(int cpu, int ring, struct pmc *pm, struct trapframe *tf, 4550 int inuserspace) 4551 { 4552 int error, callchaindepth; 4553 struct thread *td; 4554 struct pmc_sample *ps; 4555 struct pmc_samplebuffer *psb; 4556 4557 error = 0; 4558 4559 /* 4560 * Allocate space for a sample buffer. 4561 */ 4562 psb = pmc_pcpu[cpu]->pc_sb[ring]; 4563 4564 ps = psb->ps_write; 4565 if (ps->ps_nsamples) { /* in use, reader hasn't caught up */ 4566 pm->pm_pcpu_state[cpu].pps_stalled = 1; 4567 counter_u64_add(pmc_stats.pm_intr_bufferfull, 1); 4568 PMCDBG6(SAM,INT,1,"(spc) cpu=%d pm=%p tf=%p um=%d wr=%d rd=%d", 4569 cpu, pm, (void *) tf, inuserspace, 4570 (int) (psb->ps_write - psb->ps_samples), 4571 (int) (psb->ps_read - psb->ps_samples)); 4572 callchaindepth = 1; 4573 error = ENOMEM; 4574 goto done; 4575 } 4576 4577 4578 /* Fill in entry. */ 4579 PMCDBG6(SAM,INT,1,"cpu=%d pm=%p tf=%p um=%d wr=%d rd=%d", cpu, pm, 4580 (void *) tf, inuserspace, 4581 (int) (psb->ps_write - psb->ps_samples), 4582 (int) (psb->ps_read - psb->ps_samples)); 4583 4584 KASSERT(counter_u64_fetch(pm->pm_runcount) >= 0, 4585 ("[pmc,%d] pm=%p runcount %ld", __LINE__, (void *) pm, 4586 (unsigned long)counter_u64_fetch(pm->pm_runcount))); 4587 4588 counter_u64_add(pm->pm_runcount, 1); /* hold onto PMC */ 4589 4590 ps->ps_pmc = pm; 4591 ps->ps_pid = -1; 4592 ps->ps_tid = -1; 4593 if ((td = curthread) != NULL) { 4594 ps->ps_tid = td->td_tid; 4595 if (td->td_proc) 4596 ps->ps_pid = td->td_proc->p_pid; 4597 } 4598 ps->ps_cpu = cpu; 4599 ps->ps_td = td; 4600 ps->ps_flags = inuserspace ? PMC_CC_F_USERSPACE : 0; 4601 4602 callchaindepth = (pm->pm_flags & PMC_F_CALLCHAIN) ? 4603 pmc_callchaindepth : 1; 4604 4605 if (callchaindepth == 1) 4606 ps->ps_pc[0] = PMC_TRAPFRAME_TO_PC(tf); 4607 else { 4608 /* 4609 * Kernel stack traversals can be done immediately, 4610 * while we defer to an AST for user space traversals. 4611 */ 4612 if (!inuserspace) { 4613 callchaindepth = 4614 pmc_save_kernel_callchain(ps->ps_pc, 4615 callchaindepth, tf); 4616 } else { 4617 pmc_post_callchain_callback(); 4618 callchaindepth = PMC_SAMPLE_INUSE; 4619 } 4620 } 4621 4622 ps->ps_nsamples = callchaindepth; /* mark entry as in use */ 4623 4624 /* increment write pointer, modulo ring buffer size */ 4625 ps++; 4626 if (ps == psb->ps_fence) 4627 psb->ps_write = psb->ps_samples; 4628 else 4629 psb->ps_write = ps; 4630 4631 done: 4632 /* mark CPU as needing processing */ 4633 if (callchaindepth != PMC_SAMPLE_INUSE) 4634 DPCPU_SET(pmc_sampled, 1); 4635 4636 return (error); 4637 } 4638 4639 /* 4640 * Capture a user call chain. This function will be called from ast() 4641 * before control returns to userland and before the process gets 4642 * rescheduled. 4643 */ 4644 4645 static void 4646 pmc_capture_user_callchain(int cpu, int ring, struct trapframe *tf) 4647 { 4648 struct pmc *pm; 4649 struct thread *td; 4650 struct pmc_sample *ps, *ps_end; 4651 struct pmc_samplebuffer *psb; 4652 #ifdef INVARIANTS 4653 int ncallchains; 4654 int nfree; 4655 #endif 4656 4657 psb = pmc_pcpu[cpu]->pc_sb[ring]; 4658 td = curthread; 4659 4660 KASSERT(td->td_pflags & TDP_CALLCHAIN, 4661 ("[pmc,%d] Retrieving callchain for thread that doesn't want it", 4662 __LINE__)); 4663 4664 #ifdef INVARIANTS 4665 ncallchains = 0; 4666 nfree = 0; 4667 #endif 4668 4669 /* 4670 * Iterate through all deferred callchain requests. 4671 * Walk from the current read pointer to the current 4672 * write pointer. 4673 */ 4674 4675 ps = psb->ps_read; 4676 ps_end = psb->ps_write; 4677 do { 4678 #ifdef INVARIANTS 4679 if ((ps->ps_pmc == NULL) || 4680 (ps->ps_pmc->pm_state != PMC_STATE_RUNNING)) 4681 nfree++; 4682 #endif 4683 if (ps->ps_nsamples != PMC_SAMPLE_INUSE) 4684 goto next; 4685 if (ps->ps_td != td) 4686 goto next; 4687 4688 KASSERT(ps->ps_cpu == cpu, 4689 ("[pmc,%d] cpu mismatch ps_cpu=%d pcpu=%d", __LINE__, 4690 ps->ps_cpu, PCPU_GET(cpuid))); 4691 4692 pm = ps->ps_pmc; 4693 4694 KASSERT(pm->pm_flags & PMC_F_CALLCHAIN, 4695 ("[pmc,%d] Retrieving callchain for PMC that doesn't " 4696 "want it", __LINE__)); 4697 4698 KASSERT(counter_u64_fetch(pm->pm_runcount) > 0, 4699 ("[pmc,%d] runcount %ld", __LINE__, (unsigned long)counter_u64_fetch(pm->pm_runcount))); 4700 4701 /* 4702 * Retrieve the callchain and mark the sample buffer 4703 * as 'processable' by the timer tick sweep code. 4704 */ 4705 ps->ps_nsamples = pmc_save_user_callchain(ps->ps_pc, 4706 pmc_callchaindepth, tf); 4707 4708 #ifdef INVARIANTS 4709 ncallchains++; 4710 #endif 4711 4712 next: 4713 /* increment the pointer, modulo sample ring size */ 4714 if (++ps == psb->ps_fence) 4715 ps = psb->ps_samples; 4716 } while (ps != ps_end); 4717 4718 #ifdef INVARIANTS 4719 KASSERT(ncallchains > 0 || nfree > 0, 4720 ("[pmc,%d] cpu %d didn't find a sample to collect", __LINE__, 4721 cpu)); 4722 #endif 4723 4724 KASSERT(td->td_pinned == 1, 4725 ("[pmc,%d] invalid td_pinned value", __LINE__)); 4726 sched_unpin(); /* Can migrate safely now. */ 4727 4728 /* mark CPU as needing processing */ 4729 DPCPU_SET(pmc_sampled, 1); 4730 } 4731 4732 /* 4733 * Process saved PC samples. 4734 */ 4735 4736 static void 4737 pmc_process_samples(int cpu, int ring) 4738 { 4739 struct pmc *pm; 4740 int adjri, n; 4741 struct thread *td; 4742 struct pmc_owner *po; 4743 struct pmc_sample *ps; 4744 struct pmc_classdep *pcd; 4745 struct pmc_samplebuffer *psb; 4746 4747 KASSERT(PCPU_GET(cpuid) == cpu, 4748 ("[pmc,%d] not on the correct CPU pcpu=%d cpu=%d", __LINE__, 4749 PCPU_GET(cpuid), cpu)); 4750 4751 psb = pmc_pcpu[cpu]->pc_sb[ring]; 4752 4753 for (n = 0; n < pmc_nsamples; n++) { /* bound on #iterations */ 4754 4755 ps = psb->ps_read; 4756 if (ps->ps_nsamples == PMC_SAMPLE_FREE) 4757 break; 4758 4759 pm = ps->ps_pmc; 4760 4761 KASSERT(counter_u64_fetch(pm->pm_runcount) > 0, 4762 ("[pmc,%d] pm=%p runcount %ld", __LINE__, (void *) pm, 4763 (unsigned long)counter_u64_fetch(pm->pm_runcount))); 4764 4765 po = pm->pm_owner; 4766 4767 KASSERT(PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)), 4768 ("[pmc,%d] pmc=%p non-sampling mode=%d", __LINE__, 4769 pm, PMC_TO_MODE(pm))); 4770 4771 /* Ignore PMCs that have been switched off */ 4772 if (pm->pm_state != PMC_STATE_RUNNING) 4773 goto entrydone; 4774 4775 /* If there is a pending AST wait for completion */ 4776 if (ps->ps_nsamples == PMC_SAMPLE_INUSE) { 4777 /* Need a rescan at a later time. */ 4778 DPCPU_SET(pmc_sampled, 1); 4779 break; 4780 } 4781 4782 PMCDBG6(SAM,OPS,1,"cpu=%d pm=%p n=%d fl=%x wr=%d rd=%d", cpu, 4783 pm, ps->ps_nsamples, ps->ps_flags, 4784 (int) (psb->ps_write - psb->ps_samples), 4785 (int) (psb->ps_read - psb->ps_samples)); 4786 4787 /* 4788 * If this is a process-mode PMC that is attached to 4789 * its owner, and if the PC is in user mode, update 4790 * profiling statistics like timer-based profiling 4791 * would have done. 4792 */ 4793 if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) { 4794 if (ps->ps_flags & PMC_CC_F_USERSPACE) { 4795 td = FIRST_THREAD_IN_PROC(po->po_owner); 4796 addupc_intr(td, ps->ps_pc[0], 1); 4797 } 4798 goto entrydone; 4799 } 4800 4801 /* 4802 * Otherwise, this is either a sampling mode PMC that 4803 * is attached to a different process than its owner, 4804 * or a system-wide sampling PMC. Dispatch a log 4805 * entry to the PMC's owner process. 4806 */ 4807 pmclog_process_callchain(pm, ps); 4808 4809 entrydone: 4810 ps->ps_nsamples = 0; /* mark entry as free */ 4811 counter_u64_add(pm->pm_runcount, -1); 4812 4813 /* increment read pointer, modulo sample size */ 4814 if (++ps == psb->ps_fence) 4815 psb->ps_read = psb->ps_samples; 4816 else 4817 psb->ps_read = ps; 4818 } 4819 4820 counter_u64_add(pmc_stats.pm_log_sweeps, 1); 4821 4822 /* Do not re-enable stalled PMCs if we failed to process any samples */ 4823 if (n == 0) 4824 return; 4825 4826 /* 4827 * Restart any stalled sampling PMCs on this CPU. 4828 * 4829 * If the NMI handler sets the pm_stalled field of a PMC after 4830 * the check below, we'll end up processing the stalled PMC at 4831 * the next hardclock tick. 4832 */ 4833 for (n = 0; n < md->pmd_npmc; n++) { 4834 pcd = pmc_ri_to_classdep(md, n, &adjri); 4835 KASSERT(pcd != NULL, 4836 ("[pmc,%d] null pcd ri=%d", __LINE__, n)); 4837 (void) (*pcd->pcd_get_config)(cpu,adjri,&pm); 4838 4839 if (pm == NULL || /* !cfg'ed */ 4840 pm->pm_state != PMC_STATE_RUNNING || /* !active */ 4841 !PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)) || /* !sampling */ 4842 !pm->pm_pcpu_state[cpu].pps_cpustate || /* !desired */ 4843 !pm->pm_pcpu_state[cpu].pps_stalled) /* !stalled */ 4844 continue; 4845 4846 pm->pm_pcpu_state[cpu].pps_stalled = 0; 4847 (*pcd->pcd_start_pmc)(cpu, adjri); 4848 } 4849 } 4850 4851 /* 4852 * Event handlers. 4853 */ 4854 4855 /* 4856 * Handle a process exit. 4857 * 4858 * Remove this process from all hash tables. If this process 4859 * owned any PMCs, turn off those PMCs and deallocate them, 4860 * removing any associations with target processes. 4861 * 4862 * This function will be called by the last 'thread' of a 4863 * process. 4864 * 4865 * XXX This eventhandler gets called early in the exit process. 4866 * Consider using a 'hook' invocation from thread_exit() or equivalent 4867 * spot. Another negative is that kse_exit doesn't seem to call 4868 * exit1() [??]. 4869 * 4870 */ 4871 4872 static void 4873 pmc_process_exit(void *arg __unused, struct proc *p) 4874 { 4875 struct pmc *pm; 4876 int adjri, cpu; 4877 unsigned int ri; 4878 int is_using_hwpmcs; 4879 struct pmc_owner *po; 4880 struct pmc_process *pp; 4881 struct pmc_classdep *pcd; 4882 pmc_value_t newvalue, tmp; 4883 4884 PROC_LOCK(p); 4885 is_using_hwpmcs = p->p_flag & P_HWPMC; 4886 PROC_UNLOCK(p); 4887 4888 /* 4889 * Log a sysexit event to all SS PMC owners. 4890 */ 4891 epoch_enter_preempt(global_epoch_preempt); 4892 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 4893 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 4894 pmclog_process_sysexit(po, p->p_pid); 4895 epoch_exit_preempt(global_epoch_preempt); 4896 4897 if (!is_using_hwpmcs) 4898 return; 4899 4900 PMC_GET_SX_XLOCK(); 4901 PMCDBG3(PRC,EXT,1,"process-exit proc=%p (%d, %s)", p, p->p_pid, 4902 p->p_comm); 4903 4904 /* 4905 * Since this code is invoked by the last thread in an exiting 4906 * process, we would have context switched IN at some prior 4907 * point. However, with PREEMPTION, kernel mode context 4908 * switches may happen any time, so we want to disable a 4909 * context switch OUT till we get any PMCs targeting this 4910 * process off the hardware. 4911 * 4912 * We also need to atomically remove this process' 4913 * entry from our target process hash table, using 4914 * PMC_FLAG_REMOVE. 4915 */ 4916 PMCDBG3(PRC,EXT,1, "process-exit proc=%p (%d, %s)", p, p->p_pid, 4917 p->p_comm); 4918 4919 critical_enter(); /* no preemption */ 4920 4921 cpu = curthread->td_oncpu; 4922 4923 if ((pp = pmc_find_process_descriptor(p, 4924 PMC_FLAG_REMOVE)) != NULL) { 4925 4926 PMCDBG2(PRC,EXT,2, 4927 "process-exit proc=%p pmc-process=%p", p, pp); 4928 4929 /* 4930 * The exiting process could the target of 4931 * some PMCs which will be running on 4932 * currently executing CPU. 4933 * 4934 * We need to turn these PMCs off like we 4935 * would do at context switch OUT time. 4936 */ 4937 for (ri = 0; ri < md->pmd_npmc; ri++) { 4938 4939 /* 4940 * Pick up the pmc pointer from hardware 4941 * state similar to the CSW_OUT code. 4942 */ 4943 pm = NULL; 4944 4945 pcd = pmc_ri_to_classdep(md, ri, &adjri); 4946 4947 (void) (*pcd->pcd_get_config)(cpu, adjri, &pm); 4948 4949 PMCDBG2(PRC,EXT,2, "ri=%d pm=%p", ri, pm); 4950 4951 if (pm == NULL || 4952 !PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) 4953 continue; 4954 4955 PMCDBG4(PRC,EXT,2, "ppmcs[%d]=%p pm=%p " 4956 "state=%d", ri, pp->pp_pmcs[ri].pp_pmc, 4957 pm, pm->pm_state); 4958 4959 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 4960 ("[pmc,%d] ri mismatch pmc(%d) ri(%d)", 4961 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 4962 4963 KASSERT(pm == pp->pp_pmcs[ri].pp_pmc, 4964 ("[pmc,%d] pm %p != pp_pmcs[%d] %p", 4965 __LINE__, pm, ri, pp->pp_pmcs[ri].pp_pmc)); 4966 4967 KASSERT(counter_u64_fetch(pm->pm_runcount) > 0, 4968 ("[pmc,%d] bad runcount ri %d rc %ld", 4969 __LINE__, ri, (unsigned long)counter_u64_fetch(pm->pm_runcount))); 4970 4971 /* 4972 * Change desired state, and then stop if not 4973 * stalled. This two-step dance should avoid 4974 * race conditions where an interrupt re-enables 4975 * the PMC after this code has already checked 4976 * the pm_stalled flag. 4977 */ 4978 if (pm->pm_pcpu_state[cpu].pps_cpustate) { 4979 pm->pm_pcpu_state[cpu].pps_cpustate = 0; 4980 if (!pm->pm_pcpu_state[cpu].pps_stalled) { 4981 (void) pcd->pcd_stop_pmc(cpu, adjri); 4982 4983 if (PMC_TO_MODE(pm) == PMC_MODE_TC) { 4984 pcd->pcd_read_pmc(cpu, adjri, 4985 &newvalue); 4986 tmp = newvalue - 4987 PMC_PCPU_SAVED(cpu,ri); 4988 4989 mtx_pool_lock_spin(pmc_mtxpool, 4990 pm); 4991 pm->pm_gv.pm_savedvalue += tmp; 4992 pp->pp_pmcs[ri].pp_pmcval += 4993 tmp; 4994 mtx_pool_unlock_spin( 4995 pmc_mtxpool, pm); 4996 } 4997 } 4998 } 4999 5000 counter_u64_add(pm->pm_runcount, -1); 5001 5002 KASSERT((int) counter_u64_fetch(pm->pm_runcount) >= 0, 5003 ("[pmc,%d] runcount is %d", __LINE__, ri)); 5004 5005 (void) pcd->pcd_config_pmc(cpu, adjri, NULL); 5006 } 5007 5008 /* 5009 * Inform the MD layer of this pseudo "context switch 5010 * out" 5011 */ 5012 (void) md->pmd_switch_out(pmc_pcpu[cpu], pp); 5013 5014 critical_exit(); /* ok to be pre-empted now */ 5015 5016 /* 5017 * Unlink this process from the PMCs that are 5018 * targeting it. This will send a signal to 5019 * all PMC owner's whose PMCs are orphaned. 5020 * 5021 * Log PMC value at exit time if requested. 5022 */ 5023 for (ri = 0; ri < md->pmd_npmc; ri++) 5024 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) { 5025 if (pm->pm_flags & PMC_F_NEEDS_LOGFILE && 5026 PMC_IS_COUNTING_MODE(PMC_TO_MODE(pm))) 5027 pmclog_process_procexit(pm, pp); 5028 pmc_unlink_target_process(pm, pp); 5029 } 5030 free(pp, M_PMC); 5031 5032 } else 5033 critical_exit(); /* pp == NULL */ 5034 5035 5036 /* 5037 * If the process owned PMCs, free them up and free up 5038 * memory. 5039 */ 5040 if ((po = pmc_find_owner_descriptor(p)) != NULL) { 5041 pmc_remove_owner(po); 5042 pmc_destroy_owner_descriptor(po); 5043 } 5044 5045 sx_xunlock(&pmc_sx); 5046 } 5047 5048 /* 5049 * Handle a process fork. 5050 * 5051 * If the parent process 'p1' is under HWPMC monitoring, then copy 5052 * over any attached PMCs that have 'do_descendants' semantics. 5053 */ 5054 5055 static void 5056 pmc_process_fork(void *arg __unused, struct proc *p1, struct proc *newproc, 5057 int flags) 5058 { 5059 int is_using_hwpmcs; 5060 unsigned int ri; 5061 uint32_t do_descendants; 5062 struct pmc *pm; 5063 struct pmc_owner *po; 5064 struct pmc_process *ppnew, *ppold; 5065 5066 (void) flags; /* unused parameter */ 5067 5068 PROC_LOCK(p1); 5069 is_using_hwpmcs = p1->p_flag & P_HWPMC; 5070 PROC_UNLOCK(p1); 5071 5072 /* 5073 * If there are system-wide sampling PMCs active, we need to 5074 * log all fork events to their owner's logs. 5075 */ 5076 epoch_enter_preempt(global_epoch_preempt); 5077 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 5078 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 5079 pmclog_process_procfork(po, p1->p_pid, newproc->p_pid); 5080 epoch_exit_preempt(global_epoch_preempt); 5081 5082 if (!is_using_hwpmcs) 5083 return; 5084 5085 PMC_GET_SX_XLOCK(); 5086 PMCDBG4(PMC,FRK,1, "process-fork proc=%p (%d, %s) -> %p", p1, 5087 p1->p_pid, p1->p_comm, newproc); 5088 5089 /* 5090 * If the parent process (curthread->td_proc) is a 5091 * target of any PMCs, look for PMCs that are to be 5092 * inherited, and link these into the new process 5093 * descriptor. 5094 */ 5095 if ((ppold = pmc_find_process_descriptor(curthread->td_proc, 5096 PMC_FLAG_NONE)) == NULL) 5097 goto done; /* nothing to do */ 5098 5099 do_descendants = 0; 5100 for (ri = 0; ri < md->pmd_npmc; ri++) 5101 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL) 5102 do_descendants |= pm->pm_flags & PMC_F_DESCENDANTS; 5103 if (do_descendants == 0) /* nothing to do */ 5104 goto done; 5105 5106 /* 5107 * Now mark the new process as being tracked by this driver. 5108 */ 5109 PROC_LOCK(newproc); 5110 newproc->p_flag |= P_HWPMC; 5111 PROC_UNLOCK(newproc); 5112 5113 /* allocate a descriptor for the new process */ 5114 if ((ppnew = pmc_find_process_descriptor(newproc, 5115 PMC_FLAG_ALLOCATE)) == NULL) 5116 goto done; 5117 5118 /* 5119 * Run through all PMCs that were targeting the old process 5120 * and which specified F_DESCENDANTS and attach them to the 5121 * new process. 5122 * 5123 * Log the fork event to all owners of PMCs attached to this 5124 * process, if not already logged. 5125 */ 5126 for (ri = 0; ri < md->pmd_npmc; ri++) 5127 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL && 5128 (pm->pm_flags & PMC_F_DESCENDANTS)) { 5129 pmc_link_target_process(pm, ppnew); 5130 po = pm->pm_owner; 5131 if (po->po_sscount == 0 && 5132 po->po_flags & PMC_PO_OWNS_LOGFILE) 5133 pmclog_process_procfork(po, p1->p_pid, 5134 newproc->p_pid); 5135 } 5136 5137 done: 5138 sx_xunlock(&pmc_sx); 5139 } 5140 5141 static void 5142 pmc_kld_load(void *arg __unused, linker_file_t lf) 5143 { 5144 struct pmc_owner *po; 5145 5146 /* 5147 * Notify owners of system sampling PMCs about KLD operations. 5148 */ 5149 epoch_enter_preempt(global_epoch_preempt); 5150 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 5151 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 5152 pmclog_process_map_in(po, (pid_t) -1, 5153 (uintfptr_t) lf->address, lf->filename); 5154 epoch_exit_preempt(global_epoch_preempt); 5155 5156 /* 5157 * TODO: Notify owners of (all) process-sampling PMCs too. 5158 */ 5159 } 5160 5161 static void 5162 pmc_kld_unload(void *arg __unused, const char *filename __unused, 5163 caddr_t address, size_t size) 5164 { 5165 struct pmc_owner *po; 5166 5167 epoch_enter_preempt(global_epoch_preempt); 5168 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 5169 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 5170 pmclog_process_map_out(po, (pid_t) -1, 5171 (uintfptr_t) address, (uintfptr_t) address + size); 5172 epoch_exit_preempt(global_epoch_preempt); 5173 5174 /* 5175 * TODO: Notify owners of process-sampling PMCs. 5176 */ 5177 } 5178 5179 /* 5180 * initialization 5181 */ 5182 static const char * 5183 pmc_name_of_pmcclass(enum pmc_class class) 5184 { 5185 5186 switch (class) { 5187 #undef __PMC_CLASS 5188 #define __PMC_CLASS(S,V,D) \ 5189 case PMC_CLASS_##S: \ 5190 return #S; 5191 __PMC_CLASSES(); 5192 default: 5193 return ("<unknown>"); 5194 } 5195 } 5196 5197 /* 5198 * Base class initializer: allocate structure and set default classes. 5199 */ 5200 struct pmc_mdep * 5201 pmc_mdep_alloc(int nclasses) 5202 { 5203 struct pmc_mdep *md; 5204 int n; 5205 5206 /* SOFT + md classes */ 5207 n = 1 + nclasses; 5208 md = malloc(sizeof(struct pmc_mdep) + n * 5209 sizeof(struct pmc_classdep), M_PMC, M_WAITOK|M_ZERO); 5210 md->pmd_nclass = n; 5211 5212 /* Add base class. */ 5213 pmc_soft_initialize(md); 5214 return md; 5215 } 5216 5217 void 5218 pmc_mdep_free(struct pmc_mdep *md) 5219 { 5220 pmc_soft_finalize(md); 5221 free(md, M_PMC); 5222 } 5223 5224 static int 5225 generic_switch_in(struct pmc_cpu *pc, struct pmc_process *pp) 5226 { 5227 (void) pc; (void) pp; 5228 5229 return (0); 5230 } 5231 5232 static int 5233 generic_switch_out(struct pmc_cpu *pc, struct pmc_process *pp) 5234 { 5235 (void) pc; (void) pp; 5236 5237 return (0); 5238 } 5239 5240 static struct pmc_mdep * 5241 pmc_generic_cpu_initialize(void) 5242 { 5243 struct pmc_mdep *md; 5244 5245 md = pmc_mdep_alloc(0); 5246 5247 md->pmd_cputype = PMC_CPU_GENERIC; 5248 5249 md->pmd_pcpu_init = NULL; 5250 md->pmd_pcpu_fini = NULL; 5251 md->pmd_switch_in = generic_switch_in; 5252 md->pmd_switch_out = generic_switch_out; 5253 5254 return (md); 5255 } 5256 5257 static void 5258 pmc_generic_cpu_finalize(struct pmc_mdep *md) 5259 { 5260 (void) md; 5261 } 5262 5263 5264 static int 5265 pmc_initialize(void) 5266 { 5267 int c, cpu, error, n, ri; 5268 unsigned int maxcpu, domain; 5269 struct pcpu *pc; 5270 struct pmc_binding pb; 5271 struct pmc_sample *ps; 5272 struct pmc_classdep *pcd; 5273 struct pmc_samplebuffer *sb; 5274 5275 md = NULL; 5276 error = 0; 5277 5278 pmc_stats.pm_intr_ignored = counter_u64_alloc(M_WAITOK); 5279 pmc_stats.pm_intr_processed = counter_u64_alloc(M_WAITOK); 5280 pmc_stats.pm_intr_bufferfull = counter_u64_alloc(M_WAITOK); 5281 pmc_stats.pm_syscalls = counter_u64_alloc(M_WAITOK); 5282 pmc_stats.pm_syscall_errors = counter_u64_alloc(M_WAITOK); 5283 pmc_stats.pm_buffer_requests = counter_u64_alloc(M_WAITOK); 5284 pmc_stats.pm_buffer_requests_failed = counter_u64_alloc(M_WAITOK); 5285 pmc_stats.pm_log_sweeps = counter_u64_alloc(M_WAITOK); 5286 5287 #ifdef HWPMC_DEBUG 5288 /* parse debug flags first */ 5289 if (TUNABLE_STR_FETCH(PMC_SYSCTL_NAME_PREFIX "debugflags", 5290 pmc_debugstr, sizeof(pmc_debugstr))) 5291 pmc_debugflags_parse(pmc_debugstr, 5292 pmc_debugstr+strlen(pmc_debugstr)); 5293 #endif 5294 5295 PMCDBG1(MOD,INI,0, "PMC Initialize (version %x)", PMC_VERSION); 5296 5297 /* check kernel version */ 5298 if (pmc_kernel_version != PMC_VERSION) { 5299 if (pmc_kernel_version == 0) 5300 printf("hwpmc: this kernel has not been compiled with " 5301 "'options HWPMC_HOOKS'.\n"); 5302 else 5303 printf("hwpmc: kernel version (0x%x) does not match " 5304 "module version (0x%x).\n", pmc_kernel_version, 5305 PMC_VERSION); 5306 return EPROGMISMATCH; 5307 } 5308 5309 /* 5310 * check sysctl parameters 5311 */ 5312 5313 if (pmc_hashsize <= 0) { 5314 (void) printf("hwpmc: tunable \"hashsize\"=%d must be " 5315 "greater than zero.\n", pmc_hashsize); 5316 pmc_hashsize = PMC_HASH_SIZE; 5317 } 5318 5319 if (pmc_nsamples <= 0 || pmc_nsamples > 65535) { 5320 (void) printf("hwpmc: tunable \"nsamples\"=%d out of " 5321 "range.\n", pmc_nsamples); 5322 pmc_nsamples = PMC_NSAMPLES; 5323 } 5324 5325 if (pmc_callchaindepth <= 0 || 5326 pmc_callchaindepth > PMC_CALLCHAIN_DEPTH_MAX) { 5327 (void) printf("hwpmc: tunable \"callchaindepth\"=%d out of " 5328 "range - using %d.\n", pmc_callchaindepth, 5329 PMC_CALLCHAIN_DEPTH_MAX); 5330 pmc_callchaindepth = PMC_CALLCHAIN_DEPTH_MAX; 5331 } 5332 5333 md = pmc_md_initialize(); 5334 if (md == NULL) { 5335 /* Default to generic CPU. */ 5336 md = pmc_generic_cpu_initialize(); 5337 if (md == NULL) 5338 return (ENOSYS); 5339 } 5340 5341 KASSERT(md->pmd_nclass >= 1 && md->pmd_npmc >= 1, 5342 ("[pmc,%d] no classes or pmcs", __LINE__)); 5343 5344 /* Compute the map from row-indices to classdep pointers. */ 5345 pmc_rowindex_to_classdep = malloc(sizeof(struct pmc_classdep *) * 5346 md->pmd_npmc, M_PMC, M_WAITOK|M_ZERO); 5347 5348 for (n = 0; n < md->pmd_npmc; n++) 5349 pmc_rowindex_to_classdep[n] = NULL; 5350 for (ri = c = 0; c < md->pmd_nclass; c++) { 5351 pcd = &md->pmd_classdep[c]; 5352 for (n = 0; n < pcd->pcd_num; n++, ri++) 5353 pmc_rowindex_to_classdep[ri] = pcd; 5354 } 5355 5356 KASSERT(ri == md->pmd_npmc, 5357 ("[pmc,%d] npmc miscomputed: ri=%d, md->npmc=%d", __LINE__, 5358 ri, md->pmd_npmc)); 5359 5360 maxcpu = pmc_cpu_max(); 5361 5362 /* allocate space for the per-cpu array */ 5363 pmc_pcpu = malloc(maxcpu * sizeof(struct pmc_cpu *), M_PMC, 5364 M_WAITOK|M_ZERO); 5365 5366 /* per-cpu 'saved values' for managing process-mode PMCs */ 5367 pmc_pcpu_saved = malloc(sizeof(pmc_value_t) * maxcpu * md->pmd_npmc, 5368 M_PMC, M_WAITOK); 5369 5370 /* Perform CPU-dependent initialization. */ 5371 pmc_save_cpu_binding(&pb); 5372 error = 0; 5373 for (cpu = 0; error == 0 && cpu < maxcpu; cpu++) { 5374 if (!pmc_cpu_is_active(cpu)) 5375 continue; 5376 pmc_select_cpu(cpu); 5377 pmc_pcpu[cpu] = malloc(sizeof(struct pmc_cpu) + 5378 md->pmd_npmc * sizeof(struct pmc_hw *), M_PMC, 5379 M_WAITOK|M_ZERO); 5380 if (md->pmd_pcpu_init) 5381 error = md->pmd_pcpu_init(md, cpu); 5382 for (n = 0; error == 0 && n < md->pmd_nclass; n++) 5383 error = md->pmd_classdep[n].pcd_pcpu_init(md, cpu); 5384 } 5385 pmc_restore_cpu_binding(&pb); 5386 5387 if (error) 5388 return (error); 5389 5390 /* allocate space for the sample array */ 5391 for (cpu = 0; cpu < maxcpu; cpu++) { 5392 if (!pmc_cpu_is_active(cpu)) 5393 continue; 5394 pc = pcpu_find(cpu); 5395 domain = pc->pc_domain; 5396 sb = malloc_domain(sizeof(struct pmc_samplebuffer) + 5397 pmc_nsamples * sizeof(struct pmc_sample), M_PMC, domain, 5398 M_WAITOK|M_ZERO); 5399 sb->ps_read = sb->ps_write = sb->ps_samples; 5400 sb->ps_fence = sb->ps_samples + pmc_nsamples; 5401 5402 KASSERT(pmc_pcpu[cpu] != NULL, 5403 ("[pmc,%d] cpu=%d Null per-cpu data", __LINE__, cpu)); 5404 5405 sb->ps_callchains = malloc_domain(pmc_callchaindepth * pmc_nsamples * 5406 sizeof(uintptr_t), M_PMC, domain, M_WAITOK|M_ZERO); 5407 5408 for (n = 0, ps = sb->ps_samples; n < pmc_nsamples; n++, ps++) 5409 ps->ps_pc = sb->ps_callchains + 5410 (n * pmc_callchaindepth); 5411 5412 pmc_pcpu[cpu]->pc_sb[PMC_HR] = sb; 5413 5414 sb = malloc_domain(sizeof(struct pmc_samplebuffer) + 5415 pmc_nsamples * sizeof(struct pmc_sample), M_PMC, domain, 5416 M_WAITOK|M_ZERO); 5417 sb->ps_read = sb->ps_write = sb->ps_samples; 5418 sb->ps_fence = sb->ps_samples + pmc_nsamples; 5419 5420 KASSERT(pmc_pcpu[cpu] != NULL, 5421 ("[pmc,%d] cpu=%d Null per-cpu data", __LINE__, cpu)); 5422 5423 sb->ps_callchains = malloc_domain(pmc_callchaindepth * pmc_nsamples * 5424 sizeof(uintptr_t), M_PMC, domain, M_WAITOK|M_ZERO); 5425 5426 for (n = 0, ps = sb->ps_samples; n < pmc_nsamples; n++, ps++) 5427 ps->ps_pc = sb->ps_callchains + 5428 (n * pmc_callchaindepth); 5429 5430 pmc_pcpu[cpu]->pc_sb[PMC_SR] = sb; 5431 } 5432 5433 /* allocate space for the row disposition array */ 5434 pmc_pmcdisp = malloc(sizeof(enum pmc_mode) * md->pmd_npmc, 5435 M_PMC, M_WAITOK|M_ZERO); 5436 5437 /* mark all PMCs as available */ 5438 for (n = 0; n < (int) md->pmd_npmc; n++) 5439 PMC_MARK_ROW_FREE(n); 5440 5441 /* allocate thread hash tables */ 5442 pmc_ownerhash = hashinit(pmc_hashsize, M_PMC, 5443 &pmc_ownerhashmask); 5444 5445 pmc_processhash = hashinit(pmc_hashsize, M_PMC, 5446 &pmc_processhashmask); 5447 mtx_init(&pmc_processhash_mtx, "pmc-process-hash", "pmc-leaf", 5448 MTX_SPIN); 5449 5450 CK_LIST_INIT(&pmc_ss_owners); 5451 pmc_ss_count = 0; 5452 5453 /* allocate a pool of spin mutexes */ 5454 pmc_mtxpool = mtx_pool_create("pmc-leaf", pmc_mtxpool_size, 5455 MTX_SPIN); 5456 5457 PMCDBG4(MOD,INI,1, "pmc_ownerhash=%p, mask=0x%lx " 5458 "targethash=%p mask=0x%lx", pmc_ownerhash, pmc_ownerhashmask, 5459 pmc_processhash, pmc_processhashmask); 5460 5461 /* Initialize a spin mutex for the thread free list. */ 5462 mtx_init(&pmc_threadfreelist_mtx, "pmc-threadfreelist", "pmc-leaf", 5463 MTX_SPIN); 5464 5465 /* 5466 * Initialize the callout to monitor the thread free list. 5467 * This callout will also handle the initial population of the list. 5468 */ 5469 taskqgroup_config_gtask_init(NULL, &free_gtask, pmc_thread_descriptor_pool_free_task, "thread descriptor pool free task"); 5470 5471 /* register process {exit,fork,exec} handlers */ 5472 pmc_exit_tag = EVENTHANDLER_REGISTER(process_exit, 5473 pmc_process_exit, NULL, EVENTHANDLER_PRI_ANY); 5474 pmc_fork_tag = EVENTHANDLER_REGISTER(process_fork, 5475 pmc_process_fork, NULL, EVENTHANDLER_PRI_ANY); 5476 5477 /* register kld event handlers */ 5478 pmc_kld_load_tag = EVENTHANDLER_REGISTER(kld_load, pmc_kld_load, 5479 NULL, EVENTHANDLER_PRI_ANY); 5480 pmc_kld_unload_tag = EVENTHANDLER_REGISTER(kld_unload, pmc_kld_unload, 5481 NULL, EVENTHANDLER_PRI_ANY); 5482 5483 /* initialize logging */ 5484 pmclog_initialize(); 5485 5486 /* set hook functions */ 5487 pmc_intr = md->pmd_intr; 5488 wmb(); 5489 pmc_hook = pmc_hook_handler; 5490 5491 if (error == 0) { 5492 printf(PMC_MODULE_NAME ":"); 5493 for (n = 0; n < (int) md->pmd_nclass; n++) { 5494 pcd = &md->pmd_classdep[n]; 5495 printf(" %s/%d/%d/0x%b", 5496 pmc_name_of_pmcclass(pcd->pcd_class), 5497 pcd->pcd_num, 5498 pcd->pcd_width, 5499 pcd->pcd_caps, 5500 "\20" 5501 "\1INT\2USR\3SYS\4EDG\5THR" 5502 "\6REA\7WRI\10INV\11QUA\12PRC" 5503 "\13TAG\14CSC"); 5504 } 5505 printf("\n"); 5506 } 5507 5508 return (error); 5509 } 5510 5511 /* prepare to be unloaded */ 5512 static void 5513 pmc_cleanup(void) 5514 { 5515 int c, cpu; 5516 unsigned int maxcpu; 5517 struct pmc_ownerhash *ph; 5518 struct pmc_owner *po, *tmp; 5519 struct pmc_binding pb; 5520 #ifdef HWPMC_DEBUG 5521 struct pmc_processhash *prh; 5522 #endif 5523 5524 PMCDBG0(MOD,INI,0, "cleanup"); 5525 5526 /* switch off sampling */ 5527 CPU_FOREACH(cpu) 5528 DPCPU_ID_SET(cpu, pmc_sampled, 0); 5529 pmc_intr = NULL; 5530 5531 sx_xlock(&pmc_sx); 5532 if (pmc_hook == NULL) { /* being unloaded already */ 5533 sx_xunlock(&pmc_sx); 5534 return; 5535 } 5536 5537 pmc_hook = NULL; /* prevent new threads from entering module */ 5538 5539 /* deregister event handlers */ 5540 EVENTHANDLER_DEREGISTER(process_fork, pmc_fork_tag); 5541 EVENTHANDLER_DEREGISTER(process_exit, pmc_exit_tag); 5542 EVENTHANDLER_DEREGISTER(kld_load, pmc_kld_load_tag); 5543 EVENTHANDLER_DEREGISTER(kld_unload, pmc_kld_unload_tag); 5544 5545 /* send SIGBUS to all owner threads, free up allocations */ 5546 if (pmc_ownerhash) 5547 for (ph = pmc_ownerhash; 5548 ph <= &pmc_ownerhash[pmc_ownerhashmask]; 5549 ph++) { 5550 LIST_FOREACH_SAFE(po, ph, po_next, tmp) { 5551 pmc_remove_owner(po); 5552 5553 /* send SIGBUS to owner processes */ 5554 PMCDBG3(MOD,INI,2, "cleanup signal proc=%p " 5555 "(%d, %s)", po->po_owner, 5556 po->po_owner->p_pid, 5557 po->po_owner->p_comm); 5558 5559 PROC_LOCK(po->po_owner); 5560 kern_psignal(po->po_owner, SIGBUS); 5561 PROC_UNLOCK(po->po_owner); 5562 5563 pmc_destroy_owner_descriptor(po); 5564 } 5565 } 5566 5567 /* reclaim allocated data structures */ 5568 mtx_destroy(&pmc_threadfreelist_mtx); 5569 pmc_thread_descriptor_pool_drain(); 5570 5571 if (pmc_mtxpool) 5572 mtx_pool_destroy(&pmc_mtxpool); 5573 5574 mtx_destroy(&pmc_processhash_mtx); 5575 taskqgroup_config_gtask_deinit(&free_gtask); 5576 if (pmc_processhash) { 5577 #ifdef HWPMC_DEBUG 5578 struct pmc_process *pp; 5579 5580 PMCDBG0(MOD,INI,3, "destroy process hash"); 5581 for (prh = pmc_processhash; 5582 prh <= &pmc_processhash[pmc_processhashmask]; 5583 prh++) 5584 LIST_FOREACH(pp, prh, pp_next) 5585 PMCDBG1(MOD,INI,3, "pid=%d", pp->pp_proc->p_pid); 5586 #endif 5587 5588 hashdestroy(pmc_processhash, M_PMC, pmc_processhashmask); 5589 pmc_processhash = NULL; 5590 } 5591 5592 if (pmc_ownerhash) { 5593 PMCDBG0(MOD,INI,3, "destroy owner hash"); 5594 hashdestroy(pmc_ownerhash, M_PMC, pmc_ownerhashmask); 5595 pmc_ownerhash = NULL; 5596 } 5597 5598 KASSERT(CK_LIST_EMPTY(&pmc_ss_owners), 5599 ("[pmc,%d] Global SS owner list not empty", __LINE__)); 5600 KASSERT(pmc_ss_count == 0, 5601 ("[pmc,%d] Global SS count not empty", __LINE__)); 5602 5603 /* do processor and pmc-class dependent cleanup */ 5604 maxcpu = pmc_cpu_max(); 5605 5606 PMCDBG0(MOD,INI,3, "md cleanup"); 5607 if (md) { 5608 pmc_save_cpu_binding(&pb); 5609 for (cpu = 0; cpu < maxcpu; cpu++) { 5610 PMCDBG2(MOD,INI,1,"pmc-cleanup cpu=%d pcs=%p", 5611 cpu, pmc_pcpu[cpu]); 5612 if (!pmc_cpu_is_active(cpu) || pmc_pcpu[cpu] == NULL) 5613 continue; 5614 pmc_select_cpu(cpu); 5615 for (c = 0; c < md->pmd_nclass; c++) 5616 md->pmd_classdep[c].pcd_pcpu_fini(md, cpu); 5617 if (md->pmd_pcpu_fini) 5618 md->pmd_pcpu_fini(md, cpu); 5619 } 5620 5621 if (md->pmd_cputype == PMC_CPU_GENERIC) 5622 pmc_generic_cpu_finalize(md); 5623 else 5624 pmc_md_finalize(md); 5625 5626 pmc_mdep_free(md); 5627 md = NULL; 5628 pmc_restore_cpu_binding(&pb); 5629 } 5630 5631 /* Free per-cpu descriptors. */ 5632 for (cpu = 0; cpu < maxcpu; cpu++) { 5633 if (!pmc_cpu_is_active(cpu)) 5634 continue; 5635 KASSERT(pmc_pcpu[cpu]->pc_sb[PMC_HR] != NULL, 5636 ("[pmc,%d] Null hw cpu sample buffer cpu=%d", __LINE__, 5637 cpu)); 5638 KASSERT(pmc_pcpu[cpu]->pc_sb[PMC_SR] != NULL, 5639 ("[pmc,%d] Null sw cpu sample buffer cpu=%d", __LINE__, 5640 cpu)); 5641 free_domain(pmc_pcpu[cpu]->pc_sb[PMC_HR]->ps_callchains, M_PMC); 5642 free_domain(pmc_pcpu[cpu]->pc_sb[PMC_HR], M_PMC); 5643 free_domain(pmc_pcpu[cpu]->pc_sb[PMC_SR]->ps_callchains, M_PMC); 5644 free_domain(pmc_pcpu[cpu]->pc_sb[PMC_SR], M_PMC); 5645 free_domain(pmc_pcpu[cpu], M_PMC); 5646 } 5647 5648 free(pmc_pcpu, M_PMC); 5649 pmc_pcpu = NULL; 5650 5651 free(pmc_pcpu_saved, M_PMC); 5652 pmc_pcpu_saved = NULL; 5653 5654 if (pmc_pmcdisp) { 5655 free(pmc_pmcdisp, M_PMC); 5656 pmc_pmcdisp = NULL; 5657 } 5658 5659 if (pmc_rowindex_to_classdep) { 5660 free(pmc_rowindex_to_classdep, M_PMC); 5661 pmc_rowindex_to_classdep = NULL; 5662 } 5663 5664 pmclog_shutdown(); 5665 counter_u64_free(pmc_stats.pm_intr_ignored); 5666 counter_u64_free(pmc_stats.pm_intr_processed); 5667 counter_u64_free(pmc_stats.pm_intr_bufferfull); 5668 counter_u64_free(pmc_stats.pm_syscalls); 5669 counter_u64_free(pmc_stats.pm_syscall_errors); 5670 counter_u64_free(pmc_stats.pm_buffer_requests); 5671 counter_u64_free(pmc_stats.pm_buffer_requests_failed); 5672 counter_u64_free(pmc_stats.pm_log_sweeps); 5673 sx_xunlock(&pmc_sx); /* we are done */ 5674 } 5675 5676 /* 5677 * The function called at load/unload. 5678 */ 5679 5680 static int 5681 load (struct module *module __unused, int cmd, void *arg __unused) 5682 { 5683 int error; 5684 5685 error = 0; 5686 5687 switch (cmd) { 5688 case MOD_LOAD : 5689 /* initialize the subsystem */ 5690 error = pmc_initialize(); 5691 if (error != 0) 5692 break; 5693 PMCDBG2(MOD,INI,1, "syscall=%d maxcpu=%d", 5694 pmc_syscall_num, pmc_cpu_max()); 5695 break; 5696 5697 5698 case MOD_UNLOAD : 5699 case MOD_SHUTDOWN: 5700 pmc_cleanup(); 5701 PMCDBG0(MOD,INI,1, "unloaded"); 5702 break; 5703 5704 default : 5705 error = EINVAL; /* XXX should panic(9) */ 5706 break; 5707 } 5708 5709 return error; 5710 } 5711