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