1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 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 #include <sys/param.h> 35 #include <sys/systm.h> 36 #include <sys/domainset.h> 37 #include <sys/eventhandler.h> 38 #include <sys/jail.h> 39 #include <sys/kernel.h> 40 #include <sys/kthread.h> 41 #include <sys/limits.h> 42 #include <sys/lock.h> 43 #include <sys/malloc.h> 44 #include <sys/module.h> 45 #include <sys/mount.h> 46 #include <sys/mutex.h> 47 #include <sys/pmc.h> 48 #include <sys/pmckern.h> 49 #include <sys/pmclog.h> 50 #include <sys/priv.h> 51 #include <sys/proc.h> 52 #include <sys/queue.h> 53 #include <sys/resourcevar.h> 54 #include <sys/rwlock.h> 55 #include <sys/sched.h> 56 #include <sys/signalvar.h> 57 #include <sys/smp.h> 58 #include <sys/sx.h> 59 #include <sys/sysctl.h> 60 #include <sys/sysent.h> 61 #include <sys/syslog.h> 62 #include <sys/taskqueue.h> 63 #include <sys/vnode.h> 64 65 #include <sys/linker.h> /* needs to be after <sys/malloc.h> */ 66 67 #include <machine/atomic.h> 68 #include <machine/md_var.h> 69 70 #include <vm/vm.h> 71 #include <vm/vm_extern.h> 72 #include <vm/pmap.h> 73 #include <vm/vm_map.h> 74 #include <vm/vm_object.h> 75 76 #include "hwpmc_soft.h" 77 78 #define PMC_EPOCH_ENTER() \ 79 struct epoch_tracker pmc_et; \ 80 epoch_enter_preempt(global_epoch_preempt, &pmc_et) 81 82 #define PMC_EPOCH_EXIT() \ 83 epoch_exit_preempt(global_epoch_preempt, &pmc_et) 84 85 /* 86 * Types 87 */ 88 89 enum pmc_flags { 90 PMC_FLAG_NONE = 0x00, /* do nothing */ 91 PMC_FLAG_REMOVE = 0x01, /* atomically remove entry from hash */ 92 PMC_FLAG_ALLOCATE = 0x02, /* add entry to hash if not found */ 93 PMC_FLAG_NOWAIT = 0x04, /* do not wait for mallocs */ 94 }; 95 96 /* 97 * The offset in sysent where the syscall is allocated. 98 */ 99 static int pmc_syscall_num = NO_SYSCALL; 100 101 struct pmc_cpu **pmc_pcpu; /* per-cpu state */ 102 pmc_value_t *pmc_pcpu_saved; /* saved PMC values: CSW handling */ 103 104 #define PMC_PCPU_SAVED(C, R) pmc_pcpu_saved[(R) + md->pmd_npmc * (C)] 105 106 struct mtx_pool *pmc_mtxpool; 107 static int *pmc_pmcdisp; /* PMC row dispositions */ 108 109 #define PMC_ROW_DISP_IS_FREE(R) (pmc_pmcdisp[(R)] == 0) 110 #define PMC_ROW_DISP_IS_THREAD(R) (pmc_pmcdisp[(R)] > 0) 111 #define PMC_ROW_DISP_IS_STANDALONE(R) (pmc_pmcdisp[(R)] < 0) 112 113 #define PMC_MARK_ROW_FREE(R) do { \ 114 pmc_pmcdisp[(R)] = 0; \ 115 } while (0) 116 117 #define PMC_MARK_ROW_STANDALONE(R) do { \ 118 KASSERT(pmc_pmcdisp[(R)] <= 0, ("[pmc,%d] row disposition error", \ 119 __LINE__)); \ 120 atomic_add_int(&pmc_pmcdisp[(R)], -1); \ 121 KASSERT(pmc_pmcdisp[(R)] >= (-pmc_cpu_max_active()), \ 122 ("[pmc,%d] row disposition error", __LINE__)); \ 123 } while (0) 124 125 #define PMC_UNMARK_ROW_STANDALONE(R) do { \ 126 atomic_add_int(&pmc_pmcdisp[(R)], 1); \ 127 KASSERT(pmc_pmcdisp[(R)] <= 0, ("[pmc,%d] row disposition error", \ 128 __LINE__)); \ 129 } while (0) 130 131 #define PMC_MARK_ROW_THREAD(R) do { \ 132 KASSERT(pmc_pmcdisp[(R)] >= 0, ("[pmc,%d] row disposition error", \ 133 __LINE__)); \ 134 atomic_add_int(&pmc_pmcdisp[(R)], 1); \ 135 } while (0) 136 137 #define PMC_UNMARK_ROW_THREAD(R) do { \ 138 atomic_add_int(&pmc_pmcdisp[(R)], -1); \ 139 KASSERT(pmc_pmcdisp[(R)] >= 0, ("[pmc,%d] row disposition error", \ 140 __LINE__)); \ 141 } while (0) 142 143 /* various event handlers */ 144 static eventhandler_tag pmc_exit_tag, pmc_fork_tag, pmc_kld_load_tag, 145 pmc_kld_unload_tag; 146 147 /* Module statistics */ 148 struct pmc_driverstats pmc_stats; 149 150 /* Machine/processor dependent operations */ 151 static struct pmc_mdep *md; 152 153 /* 154 * Hash tables mapping owner processes and target threads to PMCs. 155 */ 156 struct mtx pmc_processhash_mtx; /* spin mutex */ 157 static u_long pmc_processhashmask; 158 static LIST_HEAD(pmc_processhash, pmc_process) *pmc_processhash; 159 160 /* 161 * Hash table of PMC owner descriptors. This table is protected by 162 * the shared PMC "sx" lock. 163 */ 164 static u_long pmc_ownerhashmask; 165 static LIST_HEAD(pmc_ownerhash, pmc_owner) *pmc_ownerhash; 166 167 /* 168 * List of PMC owners with system-wide sampling PMCs. 169 */ 170 static CK_LIST_HEAD(, pmc_owner) pmc_ss_owners; 171 172 /* 173 * List of free thread entries. This is protected by the spin 174 * mutex. 175 */ 176 static struct mtx pmc_threadfreelist_mtx; /* spin mutex */ 177 static LIST_HEAD(, pmc_thread) pmc_threadfreelist; 178 static int pmc_threadfreelist_entries = 0; 179 #define THREADENTRY_SIZE (sizeof(struct pmc_thread) + \ 180 (md->pmd_npmc * sizeof(struct pmc_threadpmcstate))) 181 182 /* 183 * Task to free thread descriptors 184 */ 185 static struct task free_task; 186 187 /* 188 * A map of row indices to classdep structures. 189 */ 190 static struct pmc_classdep **pmc_rowindex_to_classdep; 191 192 /* 193 * Prototypes 194 */ 195 196 #ifdef HWPMC_DEBUG 197 static int pmc_debugflags_sysctl_handler(SYSCTL_HANDLER_ARGS); 198 static int pmc_debugflags_parse(char *newstr, char *fence); 199 #endif 200 201 static bool pmc_is_multipart(struct pmc_sample *ps); 202 static void pmc_multipart_add(struct pmc_sample *ps, int type, 203 int length); 204 static void pmc_multipart_copydata(struct pmc_sample *ps, 205 struct pmc_multipart *mp); 206 207 static int load(struct module *module, int cmd, void *arg); 208 static int pmc_add_sample(ring_type_t ring, struct pmc *pm, 209 struct trapframe *tf, struct pmc_multipart *mp); 210 static void pmc_add_thread_descriptors_from_proc(struct proc *p, 211 struct pmc_process *pp); 212 static int pmc_attach_process(struct proc *p, struct pmc *pm); 213 static struct pmc *pmc_allocate_pmc_descriptor(void); 214 static struct pmc_owner *pmc_allocate_owner_descriptor(struct proc *p); 215 static int pmc_attach_one_process(struct proc *p, struct pmc *pm); 216 static bool pmc_can_allocate_row(int ri, enum pmc_mode mode); 217 static bool pmc_can_allocate_rowindex(struct proc *p, unsigned int ri, 218 int cpu); 219 static bool pmc_can_attach(struct pmc *pm, struct proc *p); 220 static void pmc_capture_user_callchain(int cpu, int soft, 221 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_post_callchain_callback(void); 245 static void pmc_process_allproc(struct pmc *pm); 246 static void pmc_process_csw_in(struct thread *td); 247 static void pmc_process_csw_out(struct thread *td); 248 static void pmc_process_exec(struct thread *td, 249 struct pmckern_procexec *pk); 250 static void pmc_process_exit(void *arg, struct proc *p); 251 static void pmc_process_fork(void *arg, struct proc *p1, 252 struct proc *p2, int n); 253 static void pmc_process_proccreate(struct proc *p); 254 static void pmc_process_samples(int cpu, ring_type_t soft); 255 static void pmc_process_threadcreate(struct thread *td); 256 static void pmc_process_threadexit(struct thread *td); 257 static void pmc_process_thread_add(struct thread *td); 258 static void pmc_process_thread_delete(struct thread *td); 259 static void pmc_process_thread_userret(struct thread *td); 260 static void pmc_release_pmc_descriptor(struct pmc *pmc); 261 static void pmc_remove_owner(struct pmc_owner *po); 262 static void pmc_remove_process_descriptor(struct pmc_process *pp); 263 static int pmc_start(struct pmc *pm); 264 static int pmc_stop(struct pmc *pm); 265 static int pmc_syscall_handler(struct thread *td, void *syscall_args); 266 static struct pmc_thread *pmc_thread_descriptor_pool_alloc(void); 267 static void pmc_thread_descriptor_pool_drain(void); 268 static void pmc_thread_descriptor_pool_free(struct pmc_thread *pt); 269 static void pmc_unlink_target_process(struct pmc *pmc, 270 struct pmc_process *pp); 271 272 static int generic_switch_in(struct pmc_cpu *pc, struct pmc_process *pp); 273 static int generic_switch_out(struct pmc_cpu *pc, struct pmc_process *pp); 274 static struct pmc_mdep *pmc_generic_cpu_initialize(void); 275 static void pmc_generic_cpu_finalize(struct pmc_mdep *md); 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 | CTLFLAG_MPSAFE, 0, 283 "HWPMC stats"); 284 285 /* Stats. */ 286 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, intr_ignored, CTLFLAG_RW, 287 &pmc_stats.pm_intr_ignored, 288 "# of interrupts ignored"); 289 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, intr_processed, CTLFLAG_RW, 290 &pmc_stats.pm_intr_processed, 291 "# of interrupts processed"); 292 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, intr_bufferfull, CTLFLAG_RW, 293 &pmc_stats.pm_intr_bufferfull, 294 "# of interrupts where buffer was full"); 295 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, syscalls, CTLFLAG_RW, 296 &pmc_stats.pm_syscalls, 297 "# of syscalls"); 298 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, syscall_errors, CTLFLAG_RW, 299 &pmc_stats.pm_syscall_errors, 300 "# of syscall_errors"); 301 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, buffer_requests, CTLFLAG_RW, 302 &pmc_stats.pm_buffer_requests, 303 "# of buffer requests"); 304 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, buffer_requests_failed, 305 CTLFLAG_RW, &pmc_stats.pm_buffer_requests_failed, 306 "# of buffer requests which failed"); 307 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, log_sweeps, CTLFLAG_RW, 308 &pmc_stats.pm_log_sweeps, 309 "# of times samples were processed"); 310 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, merges, CTLFLAG_RW, 311 &pmc_stats.pm_merges, 312 "# of times kernel stack was found for user trace"); 313 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, overwrites, CTLFLAG_RW, 314 &pmc_stats.pm_overwrites, 315 "# of times a sample was overwritten before being logged"); 316 317 static int pmc_callchaindepth = PMC_CALLCHAIN_DEPTH; 318 SYSCTL_INT(_kern_hwpmc, OID_AUTO, callchaindepth, CTLFLAG_RDTUN, 319 &pmc_callchaindepth, 0, 320 "depth of call chain records"); 321 322 char pmc_cpuid[PMC_CPUID_LEN]; 323 SYSCTL_STRING(_kern_hwpmc, OID_AUTO, cpuid, CTLFLAG_RD, 324 pmc_cpuid, 0, 325 "cpu version string"); 326 327 #ifdef HWPMC_DEBUG 328 struct pmc_debugflags pmc_debugflags = PMC_DEBUG_DEFAULT_FLAGS; 329 char pmc_debugstr[PMC_DEBUG_STRSIZE]; 330 TUNABLE_STR(PMC_SYSCTL_NAME_PREFIX "debugflags", pmc_debugstr, 331 sizeof(pmc_debugstr)); 332 SYSCTL_PROC(_kern_hwpmc, OID_AUTO, debugflags, 333 CTLTYPE_STRING | CTLFLAG_RWTUN | CTLFLAG_NOFETCH | CTLFLAG_MPSAFE, 334 0, 0, pmc_debugflags_sysctl_handler, "A", 335 "debug flags"); 336 #endif 337 338 /* 339 * kern.hwpmc.hashsize -- determines the number of rows in the 340 * of the hash table used to look up threads 341 */ 342 static int pmc_hashsize = PMC_HASH_SIZE; 343 SYSCTL_INT(_kern_hwpmc, OID_AUTO, hashsize, CTLFLAG_RDTUN, 344 &pmc_hashsize, 0, 345 "rows in hash tables"); 346 347 /* 348 * kern.hwpmc.nsamples --- number of PC samples/callchain stacks per CPU 349 */ 350 static int pmc_nsamples = PMC_NSAMPLES; 351 SYSCTL_INT(_kern_hwpmc, OID_AUTO, nsamples, CTLFLAG_RDTUN, 352 &pmc_nsamples, 0, 353 "number of PC samples per CPU"); 354 355 static uint64_t pmc_sample_mask = PMC_NSAMPLES - 1; 356 357 /* 358 * kern.hwpmc.mtxpoolsize -- number of mutexes in the mutex pool. 359 */ 360 static int pmc_mtxpool_size = PMC_MTXPOOL_SIZE; 361 SYSCTL_INT(_kern_hwpmc, OID_AUTO, mtxpoolsize, CTLFLAG_RDTUN, 362 &pmc_mtxpool_size, 0, 363 "size of spin mutex pool"); 364 365 /* 366 * kern.hwpmc.threadfreelist_entries -- number of free entries 367 */ 368 SYSCTL_INT(_kern_hwpmc, OID_AUTO, threadfreelist_entries, CTLFLAG_RD, 369 &pmc_threadfreelist_entries, 0, 370 "number of available thread entries"); 371 372 /* 373 * kern.hwpmc.threadfreelist_max -- maximum number of free entries 374 */ 375 static int pmc_threadfreelist_max = PMC_THREADLIST_MAX; 376 SYSCTL_INT(_kern_hwpmc, OID_AUTO, threadfreelist_max, CTLFLAG_RW, 377 &pmc_threadfreelist_max, 0, 378 "maximum number of available thread entries before freeing some"); 379 380 /* 381 * kern.hwpmc.mincount -- minimum sample count 382 */ 383 static u_int pmc_mincount = 1000; 384 SYSCTL_INT(_kern_hwpmc, OID_AUTO, mincount, CTLFLAG_RWTUN, 385 &pmc_mincount, 0, 386 "minimum count for sampling counters"); 387 388 /* 389 * security.bsd.unprivileged_syspmcs -- allow non-root processes to 390 * allocate system-wide PMCs. 391 * 392 * Allowing unprivileged processes to allocate system PMCs is convenient 393 * if system-wide measurements need to be taken concurrently with other 394 * per-process measurements. This feature is turned off by default. 395 */ 396 static int pmc_unprivileged_syspmcs = 0; 397 SYSCTL_INT(_security_bsd, OID_AUTO, unprivileged_syspmcs, CTLFLAG_RWTUN, 398 &pmc_unprivileged_syspmcs, 0, 399 "allow unprivileged process to allocate system PMCs"); 400 401 /* 402 * Hash function. Discard the lower 2 bits of the pointer since 403 * these are always zero for our uses. The hash multiplier is 404 * round((2^LONG_BIT) * ((sqrt(5)-1)/2)). 405 */ 406 #if LONG_BIT == 64 407 #define _PMC_HM 11400714819323198486u 408 #elif LONG_BIT == 32 409 #define _PMC_HM 2654435769u 410 #else 411 #error Must know the size of 'long' to compile 412 #endif 413 414 #define PMC_HASH_PTR(P,M) ((((unsigned long) (P) >> 2) * _PMC_HM) & (M)) 415 416 /* 417 * Syscall structures 418 */ 419 420 /* The `sysent' for the new syscall */ 421 static struct sysent pmc_sysent = { 422 .sy_narg = 2, 423 .sy_call = pmc_syscall_handler, 424 }; 425 426 static struct syscall_module_data pmc_syscall_mod = { 427 .chainevh = load, 428 .chainarg = NULL, 429 .offset = &pmc_syscall_num, 430 .new_sysent = &pmc_sysent, 431 .old_sysent = { .sy_narg = 0, .sy_call = NULL }, 432 .flags = SY_THR_STATIC_KLD, 433 }; 434 435 static moduledata_t pmc_mod = { 436 .name = PMC_MODULE_NAME, 437 .evhand = syscall_module_handler, 438 .priv = &pmc_syscall_mod, 439 }; 440 441 #ifdef EARLY_AP_STARTUP 442 DECLARE_MODULE(pmc, pmc_mod, SI_SUB_SYSCALLS, SI_ORDER_ANY); 443 #else 444 DECLARE_MODULE(pmc, pmc_mod, SI_SUB_SMP, SI_ORDER_ANY); 445 #endif 446 MODULE_VERSION(pmc, PMC_VERSION); 447 448 #ifdef HWPMC_DEBUG 449 enum pmc_dbgparse_state { 450 PMCDS_WS, /* in whitespace */ 451 PMCDS_MAJOR, /* seen a major keyword */ 452 PMCDS_MINOR 453 }; 454 455 static int 456 pmc_debugflags_parse(char *newstr, char *fence) 457 { 458 struct pmc_debugflags *tmpflags; 459 size_t kwlen; 460 char c, *p, *q; 461 int error, *newbits, tmp; 462 int found; 463 464 tmpflags = malloc(sizeof(*tmpflags), M_PMC, M_WAITOK | M_ZERO); 465 466 error = 0; 467 for (p = newstr; p < fence && (c = *p); p++) { 468 /* skip white space */ 469 if (c == ' ' || c == '\t') 470 continue; 471 472 /* look for a keyword followed by "=" */ 473 for (q = p; p < fence && (c = *p) && c != '='; p++) 474 ; 475 if (c != '=') { 476 error = EINVAL; 477 goto done; 478 } 479 480 kwlen = p - q; 481 newbits = NULL; 482 483 /* lookup flag group name */ 484 #define DBG_SET_FLAG_MAJ(S,F) \ 485 if (kwlen == sizeof(S)-1 && strncmp(q, S, kwlen) == 0) \ 486 newbits = &tmpflags->pdb_ ## F; 487 488 DBG_SET_FLAG_MAJ("cpu", CPU); 489 DBG_SET_FLAG_MAJ("csw", CSW); 490 DBG_SET_FLAG_MAJ("logging", LOG); 491 DBG_SET_FLAG_MAJ("module", MOD); 492 DBG_SET_FLAG_MAJ("md", MDP); 493 DBG_SET_FLAG_MAJ("owner", OWN); 494 DBG_SET_FLAG_MAJ("pmc", PMC); 495 DBG_SET_FLAG_MAJ("process", PRC); 496 DBG_SET_FLAG_MAJ("sampling", SAM); 497 #undef DBG_SET_FLAG_MAJ 498 499 if (newbits == NULL) { 500 error = EINVAL; 501 goto done; 502 } 503 504 p++; /* skip the '=' */ 505 506 /* Now parse the individual flags */ 507 tmp = 0; 508 newflag: 509 for (q = p; p < fence && (c = *p); p++) 510 if (c == ' ' || c == '\t' || c == ',') 511 break; 512 513 /* p == fence or c == ws or c == "," or c == 0 */ 514 515 if ((kwlen = p - q) == 0) { 516 *newbits = tmp; 517 continue; 518 } 519 520 found = 0; 521 #define DBG_SET_FLAG_MIN(S,F) \ 522 if (kwlen == sizeof(S)-1 && strncmp(q, S, kwlen) == 0) \ 523 tmp |= found = (1 << PMC_DEBUG_MIN_ ## F) 524 525 /* a '*' denotes all possible flags in the group */ 526 if (kwlen == 1 && *q == '*') 527 tmp = found = ~0; 528 /* look for individual flag names */ 529 DBG_SET_FLAG_MIN("allocaterow", ALR); 530 DBG_SET_FLAG_MIN("allocate", ALL); 531 DBG_SET_FLAG_MIN("attach", ATT); 532 DBG_SET_FLAG_MIN("bind", BND); 533 DBG_SET_FLAG_MIN("config", CFG); 534 DBG_SET_FLAG_MIN("exec", EXC); 535 DBG_SET_FLAG_MIN("exit", EXT); 536 DBG_SET_FLAG_MIN("find", FND); 537 DBG_SET_FLAG_MIN("flush", FLS); 538 DBG_SET_FLAG_MIN("fork", FRK); 539 DBG_SET_FLAG_MIN("getbuf", GTB); 540 DBG_SET_FLAG_MIN("hook", PMH); 541 DBG_SET_FLAG_MIN("init", INI); 542 DBG_SET_FLAG_MIN("intr", INT); 543 DBG_SET_FLAG_MIN("linktarget", TLK); 544 DBG_SET_FLAG_MIN("mayberemove", OMR); 545 DBG_SET_FLAG_MIN("ops", OPS); 546 DBG_SET_FLAG_MIN("read", REA); 547 DBG_SET_FLAG_MIN("register", REG); 548 DBG_SET_FLAG_MIN("release", REL); 549 DBG_SET_FLAG_MIN("remove", ORM); 550 DBG_SET_FLAG_MIN("sample", SAM); 551 DBG_SET_FLAG_MIN("scheduleio", SIO); 552 DBG_SET_FLAG_MIN("select", SEL); 553 DBG_SET_FLAG_MIN("signal", SIG); 554 DBG_SET_FLAG_MIN("swi", SWI); 555 DBG_SET_FLAG_MIN("swo", SWO); 556 DBG_SET_FLAG_MIN("start", STA); 557 DBG_SET_FLAG_MIN("stop", STO); 558 DBG_SET_FLAG_MIN("syscall", PMS); 559 DBG_SET_FLAG_MIN("unlinktarget", TUL); 560 DBG_SET_FLAG_MIN("write", WRI); 561 #undef DBG_SET_FLAG_MIN 562 if (found == 0) { 563 /* unrecognized flag name */ 564 error = EINVAL; 565 goto done; 566 } 567 568 if (c == 0 || c == ' ' || c == '\t') { /* end of flag group */ 569 *newbits = tmp; 570 continue; 571 } 572 573 p++; 574 goto newflag; 575 } 576 577 /* save the new flag set */ 578 bcopy(tmpflags, &pmc_debugflags, sizeof(pmc_debugflags)); 579 done: 580 free(tmpflags, M_PMC); 581 return (error); 582 } 583 584 static int 585 pmc_debugflags_sysctl_handler(SYSCTL_HANDLER_ARGS) 586 { 587 char *fence, *newstr; 588 int error; 589 u_int n; 590 591 n = sizeof(pmc_debugstr); 592 newstr = malloc(n, M_PMC, M_WAITOK | M_ZERO); 593 strlcpy(newstr, pmc_debugstr, n); 594 595 error = sysctl_handle_string(oidp, newstr, n, req); 596 597 /* if there is a new string, parse and copy it */ 598 if (error == 0 && req->newptr != NULL) { 599 fence = newstr + (n < req->newlen ? n : req->newlen + 1); 600 error = pmc_debugflags_parse(newstr, fence); 601 if (error == 0) 602 strlcpy(pmc_debugstr, newstr, sizeof(pmc_debugstr)); 603 } 604 free(newstr, M_PMC); 605 606 return (error); 607 } 608 #endif 609 610 /* 611 * Map a row index to a classdep structure and return the adjusted row 612 * index for the PMC class index. 613 */ 614 static struct pmc_classdep * 615 pmc_ri_to_classdep(struct pmc_mdep *md __unused, int ri, int *adjri) 616 { 617 struct pmc_classdep *pcd; 618 619 KASSERT(ri >= 0 && ri < md->pmd_npmc, 620 ("[pmc,%d] illegal row-index %d", __LINE__, ri)); 621 622 pcd = pmc_rowindex_to_classdep[ri]; 623 KASSERT(pcd != NULL, 624 ("[pmc,%d] ri %d null pcd", __LINE__, ri)); 625 626 *adjri = ri - pcd->pcd_ri; 627 KASSERT(*adjri >= 0 && *adjri < pcd->pcd_num, 628 ("[pmc,%d] adjusted row-index %d", __LINE__, *adjri)); 629 630 return (pcd); 631 } 632 633 /* 634 * Concurrency Control 635 * 636 * The driver manages the following data structures: 637 * 638 * - target process descriptors, one per target process 639 * - owner process descriptors (and attached lists), one per owner process 640 * - lookup hash tables for owner and target processes 641 * - PMC descriptors (and attached lists) 642 * - per-cpu hardware state 643 * - the 'hook' variable through which the kernel calls into 644 * this module 645 * - the machine hardware state (managed by the MD layer) 646 * 647 * These data structures are accessed from: 648 * 649 * - thread context-switch code 650 * - interrupt handlers (possibly on multiple cpus) 651 * - kernel threads on multiple cpus running on behalf of user 652 * processes doing system calls 653 * - this driver's private kernel threads 654 * 655 * = Locks and Locking strategy = 656 * 657 * The driver uses four locking strategies for its operation: 658 * 659 * - The global SX lock "pmc_sx" is used to protect internal 660 * data structures. 661 * 662 * Calls into the module by syscall() start with this lock being 663 * held in exclusive mode. Depending on the requested operation, 664 * the lock may be downgraded to 'shared' mode to allow more 665 * concurrent readers into the module. Calls into the module from 666 * other parts of the kernel acquire the lock in shared mode. 667 * 668 * This SX lock is held in exclusive mode for any operations that 669 * modify the linkages between the driver's internal data structures. 670 * 671 * The 'pmc_hook' function pointer is also protected by this lock. 672 * It is only examined with the sx lock held in exclusive mode. The 673 * kernel module is allowed to be unloaded only with the sx lock held 674 * in exclusive mode. In normal syscall handling, after acquiring the 675 * pmc_sx lock we first check that 'pmc_hook' is non-null before 676 * proceeding. This prevents races between the thread unloading the module 677 * and other threads seeking to use the module. 678 * 679 * - Lookups of target process structures and owner process structures 680 * cannot use the global "pmc_sx" SX lock because these lookups need 681 * to happen during context switches and in other critical sections 682 * where sleeping is not allowed. We protect these lookup tables 683 * with their own private spin-mutexes, "pmc_processhash_mtx" and 684 * "pmc_ownerhash_mtx". 685 * 686 * - Interrupt handlers work in a lock free manner. At interrupt 687 * time, handlers look at the PMC pointer (phw->phw_pmc) configured 688 * when the PMC was started. If this pointer is NULL, the interrupt 689 * is ignored after updating driver statistics. We ensure that this 690 * pointer is set (using an atomic operation if necessary) before the 691 * PMC hardware is started. Conversely, this pointer is unset atomically 692 * only after the PMC hardware is stopped. 693 * 694 * We ensure that everything needed for the operation of an 695 * interrupt handler is available without it needing to acquire any 696 * locks. We also ensure that a PMC's software state is destroyed only 697 * after the PMC is taken off hardware (on all CPUs). 698 * 699 * - Context-switch handling with process-private PMCs needs more 700 * care. 701 * 702 * A given process may be the target of multiple PMCs. For example, 703 * PMCATTACH and PMCDETACH may be requested by a process on one CPU 704 * while the target process is running on another. A PMC could also 705 * be getting released because its owner is exiting. We tackle 706 * these situations in the following manner: 707 * 708 * - each target process structure 'pmc_process' has an array 709 * of 'struct pmc *' pointers, one for each hardware PMC. 710 * 711 * - At context switch IN time, each "target" PMC in RUNNING state 712 * gets started on hardware and a pointer to each PMC is copied into 713 * the per-cpu phw array. The 'runcount' for the PMC is 714 * incremented. 715 * 716 * - At context switch OUT time, all process-virtual PMCs are stopped 717 * on hardware. The saved value is added to the PMCs value field 718 * only if the PMC is in a non-deleted state (the PMCs state could 719 * have changed during the current time slice). 720 * 721 * Note that since in-between a switch IN on a processor and a switch 722 * OUT, the PMC could have been released on another CPU. Therefore 723 * context switch OUT always looks at the hardware state to turn 724 * OFF PMCs and will update a PMC's saved value only if reachable 725 * from the target process record. 726 * 727 * - OP PMCRELEASE could be called on a PMC at any time (the PMC could 728 * be attached to many processes at the time of the call and could 729 * be active on multiple CPUs). 730 * 731 * We prevent further scheduling of the PMC by marking it as in 732 * state 'DELETED'. If the runcount of the PMC is non-zero then 733 * this PMC is currently running on a CPU somewhere. The thread 734 * doing the PMCRELEASE operation waits by repeatedly doing a 735 * pause() till the runcount comes to zero. 736 * 737 * The contents of a PMC descriptor (struct pmc) are protected using 738 * a spin-mutex. In order to save space, we use a mutex pool. 739 * 740 * In terms of lock types used by witness(4), we use: 741 * - Type "pmc-sx", used by the global SX lock. 742 * - Type "pmc-sleep", for sleep mutexes used by logger threads. 743 * - Type "pmc-per-proc", for protecting PMC owner descriptors. 744 * - Type "pmc-leaf", used for all other spin mutexes. 745 */ 746 747 /* 748 * Save the CPU binding of the current kthread. 749 */ 750 void 751 pmc_save_cpu_binding(struct pmc_binding *pb) 752 { 753 PMCDBG0(CPU,BND,2, "save-cpu"); 754 thread_lock(curthread); 755 pb->pb_bound = sched_is_bound(curthread); 756 pb->pb_cpu = curthread->td_oncpu; 757 pb->pb_priority = curthread->td_priority; 758 thread_unlock(curthread); 759 PMCDBG1(CPU,BND,2, "save-cpu cpu=%d", pb->pb_cpu); 760 } 761 762 /* 763 * Restore the CPU binding of the current thread. 764 */ 765 void 766 pmc_restore_cpu_binding(struct pmc_binding *pb) 767 { 768 PMCDBG2(CPU,BND,2, "restore-cpu curcpu=%d restore=%d", 769 curthread->td_oncpu, pb->pb_cpu); 770 thread_lock(curthread); 771 sched_bind(curthread, pb->pb_cpu); 772 if (!pb->pb_bound) 773 sched_unbind(curthread); 774 sched_prio(curthread, pb->pb_priority); 775 thread_unlock(curthread); 776 PMCDBG0(CPU,BND,2, "restore-cpu done"); 777 } 778 779 /* 780 * Move execution over to the specified CPU and bind it there. 781 */ 782 void 783 pmc_select_cpu(int cpu) 784 { 785 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 786 ("[pmc,%d] bad cpu number %d", __LINE__, cpu)); 787 788 /* Never move to an inactive CPU. */ 789 KASSERT(pmc_cpu_is_active(cpu), ("[pmc,%d] selecting inactive " 790 "CPU %d", __LINE__, cpu)); 791 792 PMCDBG1(CPU,SEL,2, "select-cpu cpu=%d", cpu); 793 thread_lock(curthread); 794 sched_prio(curthread, PRI_MIN); 795 sched_bind(curthread, cpu); 796 thread_unlock(curthread); 797 798 KASSERT(curthread->td_oncpu == cpu, 799 ("[pmc,%d] CPU not bound [cpu=%d, curr=%d]", __LINE__, 800 cpu, curthread->td_oncpu)); 801 802 PMCDBG1(CPU,SEL,2, "select-cpu cpu=%d ok", cpu); 803 } 804 805 /* 806 * Force a context switch. 807 * 808 * We do this by pause'ing for 1 tick -- invoking mi_switch() is not 809 * guaranteed to force a context switch. 810 */ 811 static void 812 pmc_force_context_switch(void) 813 { 814 815 pause("pmcctx", 1); 816 } 817 818 uint64_t 819 pmc_rdtsc(void) 820 { 821 #if defined(__i386__) || defined(__amd64__) 822 if (__predict_true(amd_feature & AMDID_RDTSCP)) 823 return (rdtscp()); 824 else 825 return (rdtsc()); 826 #else 827 return (get_cyclecount()); 828 #endif 829 } 830 831 /* 832 * Get the file name for an executable. This is a simple wrapper 833 * around vn_fullpath(9). 834 */ 835 static void 836 pmc_getfilename(struct vnode *v, char **fullpath, char **freepath) 837 { 838 839 *fullpath = "unknown"; 840 *freepath = NULL; 841 vn_fullpath(v, fullpath, freepath); 842 } 843 844 /* 845 * Remove a process owning PMCs. 846 */ 847 void 848 pmc_remove_owner(struct pmc_owner *po) 849 { 850 struct pmc *pm, *tmp; 851 852 sx_assert(&pmc_sx, SX_XLOCKED); 853 854 PMCDBG1(OWN,ORM,1, "remove-owner po=%p", po); 855 856 /* Remove descriptor from the owner hash table */ 857 LIST_REMOVE(po, po_next); 858 859 /* release all owned PMC descriptors */ 860 LIST_FOREACH_SAFE(pm, &po->po_pmcs, pm_next, tmp) { 861 PMCDBG1(OWN,ORM,2, "pmc=%p", pm); 862 KASSERT(pm->pm_owner == po, 863 ("[pmc,%d] owner %p != po %p", __LINE__, pm->pm_owner, po)); 864 865 pmc_release_pmc_descriptor(pm); /* will unlink from the list */ 866 pmc_destroy_pmc_descriptor(pm); 867 } 868 869 KASSERT(po->po_sscount == 0, 870 ("[pmc,%d] SS count not zero", __LINE__)); 871 KASSERT(LIST_EMPTY(&po->po_pmcs), 872 ("[pmc,%d] PMC list not empty", __LINE__)); 873 874 /* de-configure the log file if present */ 875 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 876 pmclog_deconfigure_log(po); 877 } 878 879 /* 880 * Remove an owner process record if all conditions are met. 881 */ 882 static void 883 pmc_maybe_remove_owner(struct pmc_owner *po) 884 { 885 886 PMCDBG1(OWN,OMR,1, "maybe-remove-owner po=%p", po); 887 888 /* 889 * Remove owner record if 890 * - this process does not own any PMCs 891 * - this process has not allocated a system-wide sampling buffer 892 */ 893 if (LIST_EMPTY(&po->po_pmcs) && 894 ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0)) { 895 pmc_remove_owner(po); 896 pmc_destroy_owner_descriptor(po); 897 } 898 } 899 900 /* 901 * Add an association between a target process and a PMC. 902 */ 903 static void 904 pmc_link_target_process(struct pmc *pm, struct pmc_process *pp) 905 { 906 struct pmc_target *pt; 907 struct pmc_thread *pt_td __diagused; 908 int ri; 909 910 sx_assert(&pmc_sx, SX_XLOCKED); 911 KASSERT(pm != NULL && pp != NULL, 912 ("[pmc,%d] Null pm %p or pp %p", __LINE__, pm, pp)); 913 KASSERT(PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)), 914 ("[pmc,%d] Attaching a non-process-virtual pmc=%p to pid=%d", 915 __LINE__, pm, pp->pp_proc->p_pid)); 916 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= ((int) md->pmd_npmc - 1), 917 ("[pmc,%d] Illegal reference count %d for process record %p", 918 __LINE__, pp->pp_refcnt, (void *) pp)); 919 920 ri = PMC_TO_ROWINDEX(pm); 921 922 PMCDBG3(PRC,TLK,1, "link-target pmc=%p ri=%d pmc-process=%p", 923 pm, ri, pp); 924 925 #ifdef HWPMC_DEBUG 926 LIST_FOREACH(pt, &pm->pm_targets, pt_next) { 927 if (pt->pt_process == pp) 928 KASSERT(0, ("[pmc,%d] pp %p already in pmc %p targets", 929 __LINE__, pp, pm)); 930 } 931 #endif 932 pt = malloc(sizeof(struct pmc_target), M_PMC, M_WAITOK | M_ZERO); 933 pt->pt_process = pp; 934 935 LIST_INSERT_HEAD(&pm->pm_targets, pt, pt_next); 936 937 atomic_store_rel_ptr((uintptr_t *)&pp->pp_pmcs[ri].pp_pmc, 938 (uintptr_t)pm); 939 940 if (pm->pm_owner->po_owner == pp->pp_proc) 941 pm->pm_flags |= PMC_F_ATTACHED_TO_OWNER; 942 943 /* 944 * Initialize the per-process values at this row index. 945 */ 946 pp->pp_pmcs[ri].pp_pmcval = PMC_TO_MODE(pm) == PMC_MODE_TS ? 947 pm->pm_sc.pm_reloadcount : 0; 948 pp->pp_refcnt++; 949 950 #ifdef INVARIANTS 951 /* Confirm that the per-thread values at this row index are cleared. */ 952 if (PMC_TO_MODE(pm) == PMC_MODE_TS) { 953 mtx_lock_spin(pp->pp_tdslock); 954 LIST_FOREACH(pt_td, &pp->pp_tds, pt_next) { 955 KASSERT(pt_td->pt_pmcs[ri].pt_pmcval == (pmc_value_t) 0, 956 ("[pmc,%d] pt_pmcval not cleared for pid=%d at " 957 "ri=%d", __LINE__, pp->pp_proc->p_pid, ri)); 958 } 959 mtx_unlock_spin(pp->pp_tdslock); 960 } 961 #endif 962 } 963 964 /* 965 * Removes the association between a target process and a PMC. 966 */ 967 static void 968 pmc_unlink_target_process(struct pmc *pm, struct pmc_process *pp) 969 { 970 int ri; 971 struct proc *p; 972 struct pmc_target *ptgt; 973 struct pmc_thread *pt; 974 975 sx_assert(&pmc_sx, SX_XLOCKED); 976 977 KASSERT(pm != NULL && pp != NULL, 978 ("[pmc,%d] Null pm %p or pp %p", __LINE__, pm, pp)); 979 980 KASSERT(pp->pp_refcnt >= 1 && pp->pp_refcnt <= (int) md->pmd_npmc, 981 ("[pmc,%d] Illegal ref count %d on process record %p", 982 __LINE__, pp->pp_refcnt, (void *) pp)); 983 984 ri = PMC_TO_ROWINDEX(pm); 985 986 PMCDBG3(PRC,TUL,1, "unlink-target pmc=%p ri=%d pmc-process=%p", 987 pm, ri, pp); 988 989 KASSERT(pp->pp_pmcs[ri].pp_pmc == pm, 990 ("[pmc,%d] PMC ri %d mismatch pmc %p pp->[ri] %p", __LINE__, 991 ri, pm, pp->pp_pmcs[ri].pp_pmc)); 992 993 pp->pp_pmcs[ri].pp_pmc = NULL; 994 pp->pp_pmcs[ri].pp_pmcval = (pmc_value_t)0; 995 996 /* Clear the per-thread values at this row index. */ 997 if (PMC_TO_MODE(pm) == PMC_MODE_TS) { 998 mtx_lock_spin(pp->pp_tdslock); 999 LIST_FOREACH(pt, &pp->pp_tds, pt_next) 1000 pt->pt_pmcs[ri].pt_pmcval = (pmc_value_t)0; 1001 mtx_unlock_spin(pp->pp_tdslock); 1002 } 1003 1004 /* Remove owner-specific flags */ 1005 if (pm->pm_owner->po_owner == pp->pp_proc) { 1006 pp->pp_flags &= ~PMC_PP_ENABLE_MSR_ACCESS; 1007 pm->pm_flags &= ~PMC_F_ATTACHED_TO_OWNER; 1008 } 1009 1010 pp->pp_refcnt--; 1011 1012 /* Remove the target process from the PMC structure */ 1013 LIST_FOREACH(ptgt, &pm->pm_targets, pt_next) 1014 if (ptgt->pt_process == pp) 1015 break; 1016 1017 KASSERT(ptgt != NULL, ("[pmc,%d] process %p (pp: %p) not found " 1018 "in pmc %p", __LINE__, pp->pp_proc, pp, pm)); 1019 1020 LIST_REMOVE(ptgt, pt_next); 1021 free(ptgt, M_PMC); 1022 1023 /* if the PMC now lacks targets, send the owner a SIGIO */ 1024 if (LIST_EMPTY(&pm->pm_targets)) { 1025 p = pm->pm_owner->po_owner; 1026 PROC_LOCK(p); 1027 kern_psignal(p, SIGIO); 1028 PROC_UNLOCK(p); 1029 1030 PMCDBG2(PRC,SIG,2, "signalling proc=%p signal=%d", p, SIGIO); 1031 } 1032 } 1033 1034 /* 1035 * Check if PMC 'pm' may be attached to target process 't'. 1036 */ 1037 1038 static bool 1039 pmc_can_attach(struct pmc *pm, struct proc *t) 1040 { 1041 struct proc *o; /* pmc owner */ 1042 struct ucred *oc, *tc; /* owner, target credentials */ 1043 bool decline_attach; 1044 1045 /* 1046 * A PMC's owner can always attach that PMC to itself. 1047 */ 1048 1049 if ((o = pm->pm_owner->po_owner) == t) 1050 return (true); 1051 1052 PROC_LOCK(o); 1053 oc = o->p_ucred; 1054 crhold(oc); 1055 PROC_UNLOCK(o); 1056 1057 PROC_LOCK(t); 1058 tc = t->p_ucred; 1059 crhold(tc); 1060 PROC_UNLOCK(t); 1061 1062 /* 1063 * The effective uid of the PMC owner should match at least one 1064 * of the {effective,real,saved} uids of the target process. 1065 */ 1066 1067 decline_attach = oc->cr_uid != tc->cr_uid && 1068 oc->cr_uid != tc->cr_svuid && 1069 oc->cr_uid != tc->cr_ruid; 1070 1071 /* 1072 * Every one of the target's group ids, must be in the owner's 1073 * group list. 1074 */ 1075 for (int i = 0; !decline_attach && i < tc->cr_ngroups; i++) 1076 decline_attach = !groupmember(tc->cr_groups[i], oc); 1077 if (!decline_attach) 1078 decline_attach = !groupmember(tc->cr_gid, oc) || 1079 !groupmember(tc->cr_rgid, oc) || 1080 !groupmember(tc->cr_svgid, oc); 1081 1082 crfree(tc); 1083 crfree(oc); 1084 1085 return (!decline_attach); 1086 } 1087 1088 /* 1089 * Attach a process to a PMC. 1090 */ 1091 static int 1092 pmc_attach_one_process(struct proc *p, struct pmc *pm) 1093 { 1094 int ri, error; 1095 char *fullpath, *freepath; 1096 struct pmc_process *pp; 1097 1098 sx_assert(&pmc_sx, SX_XLOCKED); 1099 1100 PMCDBG5(PRC,ATT,2, "attach-one pm=%p ri=%d proc=%p (%d, %s)", pm, 1101 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 1102 1103 /* 1104 * Locate the process descriptor corresponding to process 'p', 1105 * allocating space as needed. 1106 * 1107 * Verify that rowindex 'pm_rowindex' is free in the process 1108 * descriptor. 1109 * 1110 * If not, allocate space for a descriptor and link the 1111 * process descriptor and PMC. 1112 */ 1113 ri = PMC_TO_ROWINDEX(pm); 1114 1115 /* mark process as using HWPMCs */ 1116 PROC_LOCK(p); 1117 p->p_flag |= P_HWPMC; 1118 PROC_UNLOCK(p); 1119 1120 if ((pp = pmc_find_process_descriptor(p, PMC_FLAG_ALLOCATE)) == NULL) { 1121 error = ENOMEM; 1122 goto fail; 1123 } 1124 1125 if (pp->pp_pmcs[ri].pp_pmc == pm) {/* already present at slot [ri] */ 1126 error = EEXIST; 1127 goto fail; 1128 } 1129 1130 if (pp->pp_pmcs[ri].pp_pmc != NULL) { 1131 error = EBUSY; 1132 goto fail; 1133 } 1134 1135 pmc_link_target_process(pm, pp); 1136 1137 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)) && 1138 (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) == 0) 1139 pm->pm_flags |= PMC_F_NEEDS_LOGFILE; 1140 1141 pm->pm_flags |= PMC_F_ATTACH_DONE; /* mark as attached */ 1142 1143 /* issue an attach event to a configured log file */ 1144 if (pm->pm_owner->po_flags & PMC_PO_OWNS_LOGFILE) { 1145 if (p->p_flag & P_KPROC) { 1146 fullpath = kernelname; 1147 freepath = NULL; 1148 } else { 1149 pmc_getfilename(p->p_textvp, &fullpath, &freepath); 1150 pmclog_process_pmcattach(pm, p->p_pid, fullpath); 1151 } 1152 free(freepath, M_TEMP); 1153 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 1154 pmc_log_process_mappings(pm->pm_owner, p); 1155 } 1156 1157 return (0); 1158 fail: 1159 PROC_LOCK(p); 1160 p->p_flag &= ~P_HWPMC; 1161 PROC_UNLOCK(p); 1162 return (error); 1163 } 1164 1165 /* 1166 * Attach a process and optionally its children 1167 */ 1168 static int 1169 pmc_attach_process(struct proc *p, struct pmc *pm) 1170 { 1171 int error; 1172 struct proc *top; 1173 1174 sx_assert(&pmc_sx, SX_XLOCKED); 1175 1176 PMCDBG5(PRC,ATT,1, "attach pm=%p ri=%d proc=%p (%d, %s)", pm, 1177 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 1178 1179 /* 1180 * If this PMC successfully allowed a GETMSR operation 1181 * in the past, disallow further ATTACHes. 1182 */ 1183 if ((pm->pm_flags & PMC_PP_ENABLE_MSR_ACCESS) != 0) 1184 return (EPERM); 1185 1186 if ((pm->pm_flags & PMC_F_DESCENDANTS) == 0) 1187 return (pmc_attach_one_process(p, pm)); 1188 1189 /* 1190 * Traverse all child processes, attaching them to 1191 * this PMC. 1192 */ 1193 sx_slock(&proctree_lock); 1194 1195 top = p; 1196 for (;;) { 1197 if ((error = pmc_attach_one_process(p, pm)) != 0) 1198 break; 1199 if (!LIST_EMPTY(&p->p_children)) 1200 p = LIST_FIRST(&p->p_children); 1201 else for (;;) { 1202 if (p == top) 1203 goto done; 1204 if (LIST_NEXT(p, p_sibling)) { 1205 p = LIST_NEXT(p, p_sibling); 1206 break; 1207 } 1208 p = p->p_pptr; 1209 } 1210 } 1211 1212 if (error != 0) 1213 (void)pmc_detach_process(top, pm); 1214 1215 done: 1216 sx_sunlock(&proctree_lock); 1217 return (error); 1218 } 1219 1220 /* 1221 * Detach a process from a PMC. If there are no other PMCs tracking 1222 * this process, remove the process structure from its hash table. If 1223 * 'flags' contains PMC_FLAG_REMOVE, then free the process structure. 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 static int 1281 pmc_detach_process(struct proc *p, struct pmc *pm) 1282 { 1283 struct proc *top; 1284 1285 sx_assert(&pmc_sx, SX_XLOCKED); 1286 1287 PMCDBG5(PRC,ATT,1, "detach pm=%p ri=%d proc=%p (%d, %s)", pm, 1288 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 1289 1290 if ((pm->pm_flags & PMC_F_DESCENDANTS) == 0) 1291 return (pmc_detach_one_process(p, pm, PMC_FLAG_REMOVE)); 1292 1293 /* 1294 * Traverse all children, detaching them from this PMC. We 1295 * ignore errors since we could be detaching a PMC from a 1296 * partially attached proc tree. 1297 */ 1298 sx_slock(&proctree_lock); 1299 1300 top = p; 1301 for (;;) { 1302 (void)pmc_detach_one_process(p, pm, PMC_FLAG_REMOVE); 1303 1304 if (!LIST_EMPTY(&p->p_children)) { 1305 p = LIST_FIRST(&p->p_children); 1306 } else { 1307 for (;;) { 1308 if (p == top) 1309 goto done; 1310 if (LIST_NEXT(p, p_sibling)) { 1311 p = LIST_NEXT(p, p_sibling); 1312 break; 1313 } 1314 p = p->p_pptr; 1315 } 1316 } 1317 } 1318 done: 1319 sx_sunlock(&proctree_lock); 1320 if (LIST_EMPTY(&pm->pm_targets)) 1321 pm->pm_flags &= ~PMC_F_ATTACH_DONE; 1322 1323 return (0); 1324 } 1325 1326 /* 1327 * Handle events after an exec() for a process: 1328 * - Inform log owners of the new exec() event 1329 * - Release any PMCs owned by the process before the exec() 1330 * - Detach PMCs from the target if required 1331 */ 1332 static void 1333 pmc_process_exec(struct thread *td, struct pmckern_procexec *pk) 1334 { 1335 struct pmc *pm; 1336 struct pmc_owner *po; 1337 struct pmc_process *pp; 1338 struct proc *p; 1339 char *fullpath, *freepath; 1340 u_int ri; 1341 bool is_using_hwpmcs; 1342 1343 sx_assert(&pmc_sx, SX_XLOCKED); 1344 1345 p = td->td_proc; 1346 pmc_getfilename(p->p_textvp, &fullpath, &freepath); 1347 1348 PMC_EPOCH_ENTER(); 1349 /* Inform owners of SS mode PMCs of the exec event. */ 1350 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) { 1351 if ((po->po_flags & PMC_PO_OWNS_LOGFILE) != 0) { 1352 pmclog_process_procexec(po, PMC_ID_INVALID, p->p_pid, 1353 pk->pm_baseaddr, pk->pm_dynaddr, fullpath); 1354 } 1355 } 1356 PMC_EPOCH_EXIT(); 1357 1358 PROC_LOCK(p); 1359 is_using_hwpmcs = (p->p_flag & P_HWPMC) != 0; 1360 PROC_UNLOCK(p); 1361 1362 if (!is_using_hwpmcs) { 1363 if (freepath != NULL) 1364 free(freepath, M_TEMP); 1365 return; 1366 } 1367 1368 /* 1369 * PMCs are not inherited across an exec(): remove any PMCs that this 1370 * process is the owner of. 1371 */ 1372 if ((po = pmc_find_owner_descriptor(p)) != NULL) { 1373 pmc_remove_owner(po); 1374 pmc_destroy_owner_descriptor(po); 1375 } 1376 1377 /* 1378 * If the process being exec'ed is not the target of any PMC, we are 1379 * done. 1380 */ 1381 if ((pp = pmc_find_process_descriptor(p, 0)) == NULL) { 1382 if (freepath != NULL) 1383 free(freepath, M_TEMP); 1384 return; 1385 } 1386 1387 /* 1388 * Log the exec event to all monitoring owners. Skip owners who have 1389 * already received the event because they had system sampling PMCs 1390 * active. 1391 */ 1392 for (ri = 0; ri < md->pmd_npmc; ri++) { 1393 if ((pm = pp->pp_pmcs[ri].pp_pmc) == NULL) 1394 continue; 1395 1396 po = pm->pm_owner; 1397 if (po->po_sscount == 0 && 1398 (po->po_flags & PMC_PO_OWNS_LOGFILE) != 0) { 1399 pmclog_process_procexec(po, pm->pm_id, p->p_pid, 1400 pk->pm_baseaddr, pk->pm_dynaddr, fullpath); 1401 } 1402 } 1403 1404 if (freepath != NULL) 1405 free(freepath, M_TEMP); 1406 1407 PMCDBG4(PRC,EXC,1, "exec proc=%p (%d, %s) cred-changed=%d", 1408 p, p->p_pid, p->p_comm, pk->pm_credentialschanged); 1409 1410 if (pk->pm_credentialschanged == 0) /* no change */ 1411 return; 1412 1413 /* 1414 * If the newly exec()'ed process has a different credential 1415 * than before, allow it to be the target of a PMC only if 1416 * the PMC's owner has sufficient privilege. 1417 */ 1418 for (ri = 0; ri < md->pmd_npmc; ri++) { 1419 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) { 1420 if (pmc_can_attach(pm, td->td_proc)) { 1421 pmc_detach_one_process(td->td_proc, pm, 1422 PMC_FLAG_NONE); 1423 } 1424 } 1425 } 1426 1427 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= md->pmd_npmc, 1428 ("[pmc,%d] Illegal ref count %u on pp %p", __LINE__, 1429 pp->pp_refcnt, pp)); 1430 1431 /* 1432 * If this process is no longer the target of any 1433 * PMCs, we can remove the process entry and free 1434 * up space. 1435 */ 1436 if (pp->pp_refcnt == 0) { 1437 pmc_remove_process_descriptor(pp); 1438 pmc_destroy_process_descriptor(pp); 1439 } 1440 } 1441 1442 /* 1443 * Thread context switch IN. 1444 */ 1445 static void 1446 pmc_process_csw_in(struct thread *td) 1447 { 1448 struct pmc *pm; 1449 struct pmc_classdep *pcd; 1450 struct pmc_cpu *pc; 1451 struct pmc_hw *phw __diagused; 1452 struct pmc_process *pp; 1453 struct pmc_thread *pt; 1454 struct proc *p; 1455 pmc_value_t newvalue; 1456 int cpu; 1457 u_int adjri, ri; 1458 1459 p = td->td_proc; 1460 pt = NULL; 1461 if ((pp = pmc_find_process_descriptor(p, PMC_FLAG_NONE)) == NULL) 1462 return; 1463 1464 KASSERT(pp->pp_proc == td->td_proc, 1465 ("[pmc,%d] not my thread state", __LINE__)); 1466 1467 critical_enter(); /* no preemption from this point */ 1468 1469 cpu = PCPU_GET(cpuid); /* td->td_oncpu is invalid */ 1470 1471 PMCDBG5(CSW,SWI,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p, 1472 p->p_pid, p->p_comm, pp); 1473 1474 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 1475 ("[pmc,%d] weird CPU id %d", __LINE__, cpu)); 1476 1477 pc = pmc_pcpu[cpu]; 1478 for (ri = 0; ri < md->pmd_npmc; ri++) { 1479 if ((pm = pp->pp_pmcs[ri].pp_pmc) == NULL) 1480 continue; 1481 1482 KASSERT(PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)), 1483 ("[pmc,%d] Target PMC in non-virtual mode (%d)", 1484 __LINE__, PMC_TO_MODE(pm))); 1485 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 1486 ("[pmc,%d] Row index mismatch pmc %d != ri %d", 1487 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 1488 1489 /* 1490 * Only PMCs that are marked as 'RUNNING' need 1491 * be placed on hardware. 1492 */ 1493 if (pm->pm_state != PMC_STATE_RUNNING) 1494 continue; 1495 1496 KASSERT(counter_u64_fetch(pm->pm_runcount) >= 0, 1497 ("[pmc,%d] pm=%p runcount %ju", __LINE__, pm, 1498 (uintmax_t)counter_u64_fetch(pm->pm_runcount))); 1499 1500 /* increment PMC runcount */ 1501 counter_u64_add(pm->pm_runcount, 1); 1502 1503 /* configure the HWPMC we are going to use. */ 1504 pcd = pmc_ri_to_classdep(md, ri, &adjri); 1505 (void)pcd->pcd_config_pmc(cpu, adjri, pm); 1506 1507 phw = pc->pc_hwpmcs[ri]; 1508 1509 KASSERT(phw != NULL, 1510 ("[pmc,%d] null hw pointer", __LINE__)); 1511 1512 KASSERT(phw->phw_pmc == pm, 1513 ("[pmc,%d] hw->pmc %p != pmc %p", __LINE__, 1514 phw->phw_pmc, pm)); 1515 1516 /* 1517 * Write out saved value and start the PMC. 1518 * 1519 * Sampling PMCs use a per-thread value, while 1520 * counting mode PMCs use a per-pmc value that is 1521 * inherited across descendants. 1522 */ 1523 if (PMC_TO_MODE(pm) == PMC_MODE_TS) { 1524 if (pt == NULL) 1525 pt = pmc_find_thread_descriptor(pp, td, 1526 PMC_FLAG_NONE); 1527 1528 KASSERT(pt != NULL, 1529 ("[pmc,%d] No thread found for td=%p", __LINE__, 1530 td)); 1531 1532 mtx_pool_lock_spin(pmc_mtxpool, pm); 1533 1534 /* 1535 * If we have a thread descriptor, use the per-thread 1536 * counter in the descriptor. If not, we will use 1537 * a per-process counter. 1538 * 1539 * TODO: Remove the per-process "safety net" once 1540 * we have thoroughly tested that we don't hit the 1541 * above assert. 1542 */ 1543 if (pt != NULL) { 1544 if (pt->pt_pmcs[ri].pt_pmcval > 0) 1545 newvalue = pt->pt_pmcs[ri].pt_pmcval; 1546 else 1547 newvalue = pm->pm_sc.pm_reloadcount; 1548 } else { 1549 /* 1550 * Use the saved value calculated after the most 1551 * recent time a thread using the shared counter 1552 * switched out. Reset the saved count in case 1553 * another thread from this process switches in 1554 * before any threads switch out. 1555 */ 1556 newvalue = pp->pp_pmcs[ri].pp_pmcval; 1557 pp->pp_pmcs[ri].pp_pmcval = 1558 pm->pm_sc.pm_reloadcount; 1559 } 1560 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1561 KASSERT(newvalue > 0 && newvalue <= 1562 pm->pm_sc.pm_reloadcount, 1563 ("[pmc,%d] pmcval outside of expected range cpu=%d " 1564 "ri=%d pmcval=%jx pm_reloadcount=%jx", __LINE__, 1565 cpu, ri, newvalue, pm->pm_sc.pm_reloadcount)); 1566 } else { 1567 KASSERT(PMC_TO_MODE(pm) == PMC_MODE_TC, 1568 ("[pmc,%d] illegal mode=%d", __LINE__, 1569 PMC_TO_MODE(pm))); 1570 mtx_pool_lock_spin(pmc_mtxpool, pm); 1571 newvalue = PMC_PCPU_SAVED(cpu, ri) = 1572 pm->pm_gv.pm_savedvalue; 1573 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1574 } 1575 1576 PMCDBG3(CSW,SWI,1,"cpu=%d ri=%d new=%jd", cpu, ri, newvalue); 1577 1578 (void)pcd->pcd_write_pmc(cpu, adjri, pm, newvalue); 1579 1580 /* If a sampling mode PMC, reset stalled state. */ 1581 if (PMC_TO_MODE(pm) == PMC_MODE_TS) 1582 pm->pm_pcpu_state[cpu].pps_stalled = 0; 1583 1584 /* Indicate that we desire this to run. */ 1585 pm->pm_pcpu_state[cpu].pps_cpustate = 1; 1586 1587 /* Start the PMC. */ 1588 (void)pcd->pcd_start_pmc(cpu, adjri, pm); 1589 } 1590 1591 /* 1592 * Perform any other architecture/cpu dependent thread 1593 * switch-in actions. 1594 */ 1595 (void)(*md->pmd_switch_in)(pc, pp); 1596 1597 critical_exit(); 1598 } 1599 1600 /* 1601 * Thread context switch OUT. 1602 */ 1603 static void 1604 pmc_process_csw_out(struct thread *td) 1605 { 1606 struct pmc *pm; 1607 struct pmc_classdep *pcd; 1608 struct pmc_cpu *pc; 1609 struct pmc_process *pp; 1610 struct pmc_thread *pt = NULL; 1611 struct proc *p; 1612 pmc_value_t newvalue; 1613 int64_t tmp; 1614 enum pmc_mode mode; 1615 int cpu; 1616 u_int adjri, ri; 1617 1618 /* 1619 * Locate our process descriptor; this may be NULL if 1620 * this process is exiting and we have already removed 1621 * the process from the target process table. 1622 * 1623 * Note that due to kernel preemption, multiple 1624 * context switches may happen while the process is 1625 * exiting. 1626 * 1627 * Note also that if the target process cannot be 1628 * found we still need to deconfigure any PMCs that 1629 * are currently running on hardware. 1630 */ 1631 p = td->td_proc; 1632 pp = pmc_find_process_descriptor(p, PMC_FLAG_NONE); 1633 1634 critical_enter(); 1635 1636 cpu = PCPU_GET(cpuid); /* td->td_oncpu is invalid */ 1637 1638 PMCDBG5(CSW,SWO,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p, 1639 p->p_pid, p->p_comm, pp); 1640 1641 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 1642 ("[pmc,%d weird CPU id %d", __LINE__, cpu)); 1643 1644 pc = pmc_pcpu[cpu]; 1645 1646 /* 1647 * When a PMC gets unlinked from a target PMC, it will 1648 * be removed from the target's pp_pmc[] array. 1649 * 1650 * However, on a MP system, the target could have been 1651 * executing on another CPU at the time of the unlink. 1652 * So, at context switch OUT time, we need to look at 1653 * the hardware to determine if a PMC is scheduled on 1654 * it. 1655 */ 1656 for (ri = 0; ri < md->pmd_npmc; ri++) { 1657 pcd = pmc_ri_to_classdep(md, ri, &adjri); 1658 pm = NULL; 1659 (void)(*pcd->pcd_get_config)(cpu, adjri, &pm); 1660 1661 if (pm == NULL) /* nothing at this row index */ 1662 continue; 1663 1664 mode = PMC_TO_MODE(pm); 1665 if (!PMC_IS_VIRTUAL_MODE(mode)) 1666 continue; /* not a process virtual PMC */ 1667 1668 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 1669 ("[pmc,%d] ri mismatch pmc(%d) ri(%d)", 1670 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 1671 1672 /* 1673 * Change desired state, and then stop if not stalled. 1674 * This two-step dance should avoid race conditions where 1675 * an interrupt re-enables the PMC after this code has 1676 * already checked the pm_stalled flag. 1677 */ 1678 pm->pm_pcpu_state[cpu].pps_cpustate = 0; 1679 if (pm->pm_pcpu_state[cpu].pps_stalled == 0) 1680 (void)pcd->pcd_stop_pmc(cpu, adjri, pm); 1681 1682 KASSERT(counter_u64_fetch(pm->pm_runcount) > 0, 1683 ("[pmc,%d] pm=%p runcount %ju", __LINE__, pm, 1684 (uintmax_t)counter_u64_fetch(pm->pm_runcount))); 1685 1686 /* reduce this PMC's runcount */ 1687 counter_u64_add(pm->pm_runcount, -1); 1688 1689 /* 1690 * If this PMC is associated with this process, 1691 * save the reading. 1692 */ 1693 if (pm->pm_state != PMC_STATE_DELETED && pp != NULL && 1694 pp->pp_pmcs[ri].pp_pmc != NULL) { 1695 KASSERT(pm == pp->pp_pmcs[ri].pp_pmc, 1696 ("[pmc,%d] pm %p != pp_pmcs[%d] %p", __LINE__, 1697 pm, ri, pp->pp_pmcs[ri].pp_pmc)); 1698 KASSERT(pp->pp_refcnt > 0, 1699 ("[pmc,%d] pp refcnt = %d", __LINE__, 1700 pp->pp_refcnt)); 1701 1702 (void)pcd->pcd_read_pmc(cpu, adjri, pm, &newvalue); 1703 1704 if (mode == PMC_MODE_TS) { 1705 PMCDBG3(CSW,SWO,1,"cpu=%d ri=%d val=%jd (samp)", 1706 cpu, ri, newvalue); 1707 1708 if (pt == NULL) 1709 pt = pmc_find_thread_descriptor(pp, td, 1710 PMC_FLAG_NONE); 1711 1712 KASSERT(pt != NULL, 1713 ("[pmc,%d] No thread found for td=%p", 1714 __LINE__, td)); 1715 1716 mtx_pool_lock_spin(pmc_mtxpool, pm); 1717 1718 /* 1719 * If we have a thread descriptor, save the 1720 * per-thread counter in the descriptor. If not, 1721 * we will update the per-process counter. 1722 * 1723 * TODO: Remove the per-process "safety net" 1724 * once we have thoroughly tested that we 1725 * don't hit the above assert. 1726 */ 1727 if (pt != NULL) { 1728 pt->pt_pmcs[ri].pt_pmcval = newvalue; 1729 } else { 1730 /* 1731 * For sampling process-virtual PMCs, 1732 * newvalue is the number of events to 1733 * be seen until the next sampling 1734 * interrupt. We can just add the events 1735 * left from this invocation to the 1736 * counter, then adjust in case we 1737 * overflow our range. 1738 * 1739 * (Recall that we reload the counter 1740 * every time we use it.) 1741 */ 1742 pp->pp_pmcs[ri].pp_pmcval += newvalue; 1743 if (pp->pp_pmcs[ri].pp_pmcval > 1744 pm->pm_sc.pm_reloadcount) { 1745 pp->pp_pmcs[ri].pp_pmcval -= 1746 pm->pm_sc.pm_reloadcount; 1747 } 1748 } 1749 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1750 } else { 1751 tmp = newvalue - PMC_PCPU_SAVED(cpu, ri); 1752 1753 PMCDBG3(CSW,SWO,1,"cpu=%d ri=%d tmp=%jd (count)", 1754 cpu, ri, tmp); 1755 1756 /* 1757 * For counting process-virtual PMCs, 1758 * we expect the count to be 1759 * increasing monotonically, modulo a 64 1760 * bit wraparound. 1761 */ 1762 KASSERT(tmp >= 0, 1763 ("[pmc,%d] negative increment cpu=%d " 1764 "ri=%d newvalue=%jx saved=%jx " 1765 "incr=%jx", __LINE__, cpu, ri, 1766 newvalue, PMC_PCPU_SAVED(cpu, ri), tmp)); 1767 1768 mtx_pool_lock_spin(pmc_mtxpool, pm); 1769 pm->pm_gv.pm_savedvalue += tmp; 1770 pp->pp_pmcs[ri].pp_pmcval += tmp; 1771 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1772 1773 if (pm->pm_flags & PMC_F_LOG_PROCCSW) 1774 pmclog_process_proccsw(pm, pp, tmp, td); 1775 } 1776 } 1777 1778 /* Mark hardware as free. */ 1779 (void)pcd->pcd_config_pmc(cpu, adjri, NULL); 1780 } 1781 1782 /* 1783 * Perform any other architecture/cpu dependent thread 1784 * switch out functions. 1785 */ 1786 (void)(*md->pmd_switch_out)(pc, pp); 1787 1788 critical_exit(); 1789 } 1790 1791 /* 1792 * A new thread for a process. 1793 */ 1794 static void 1795 pmc_process_thread_add(struct thread *td) 1796 { 1797 struct pmc_process *pmc; 1798 1799 pmc = pmc_find_process_descriptor(td->td_proc, PMC_FLAG_NONE); 1800 if (pmc != NULL) 1801 pmc_find_thread_descriptor(pmc, td, PMC_FLAG_ALLOCATE); 1802 } 1803 1804 /* 1805 * A thread delete for a process. 1806 */ 1807 static void 1808 pmc_process_thread_delete(struct thread *td) 1809 { 1810 struct pmc_process *pmc; 1811 1812 pmc = pmc_find_process_descriptor(td->td_proc, PMC_FLAG_NONE); 1813 if (pmc != NULL) 1814 pmc_thread_descriptor_pool_free(pmc_find_thread_descriptor(pmc, 1815 td, PMC_FLAG_REMOVE)); 1816 } 1817 1818 /* 1819 * A userret() call for a thread. 1820 */ 1821 static void 1822 pmc_process_thread_userret(struct thread *td) 1823 { 1824 sched_pin(); 1825 pmc_capture_user_callchain(curcpu, PMC_UR, td->td_frame); 1826 sched_unpin(); 1827 } 1828 1829 /* 1830 * A mapping change for a process. 1831 */ 1832 static void 1833 pmc_process_mmap(struct thread *td, struct pmckern_map_in *pkm) 1834 { 1835 const struct pmc *pm; 1836 const struct pmc_process *pp; 1837 struct pmc_owner *po; 1838 char *fullpath, *freepath; 1839 pid_t pid; 1840 int ri; 1841 1842 MPASS(!in_epoch(global_epoch_preempt)); 1843 1844 freepath = fullpath = NULL; 1845 pmc_getfilename((struct vnode *)pkm->pm_file, &fullpath, &freepath); 1846 1847 pid = td->td_proc->p_pid; 1848 1849 PMC_EPOCH_ENTER(); 1850 /* Inform owners of all system-wide sampling PMCs. */ 1851 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) { 1852 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1853 pmclog_process_map_in(po, pid, pkm->pm_address, 1854 fullpath); 1855 } 1856 1857 if ((pp = pmc_find_process_descriptor(td->td_proc, 0)) == NULL) 1858 goto done; 1859 1860 /* 1861 * Inform sampling PMC owners tracking this process. 1862 */ 1863 for (ri = 0; ri < md->pmd_npmc; ri++) { 1864 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL && 1865 PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) { 1866 pmclog_process_map_in(pm->pm_owner, 1867 pid, pkm->pm_address, fullpath); 1868 } 1869 } 1870 1871 done: 1872 if (freepath != NULL) 1873 free(freepath, M_TEMP); 1874 PMC_EPOCH_EXIT(); 1875 } 1876 1877 /* 1878 * Log an munmap request. 1879 */ 1880 static void 1881 pmc_process_munmap(struct thread *td, struct pmckern_map_out *pkm) 1882 { 1883 const struct pmc *pm; 1884 const struct pmc_process *pp; 1885 struct pmc_owner *po; 1886 pid_t pid; 1887 int ri; 1888 1889 pid = td->td_proc->p_pid; 1890 1891 PMC_EPOCH_ENTER(); 1892 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) { 1893 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1894 pmclog_process_map_out(po, pid, pkm->pm_address, 1895 pkm->pm_address + pkm->pm_size); 1896 } 1897 PMC_EPOCH_EXIT(); 1898 1899 if ((pp = pmc_find_process_descriptor(td->td_proc, 0)) == NULL) 1900 return; 1901 1902 for (ri = 0; ri < md->pmd_npmc; ri++) { 1903 pm = pp->pp_pmcs[ri].pp_pmc; 1904 if (pm != NULL && PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) { 1905 pmclog_process_map_out(pm->pm_owner, pid, 1906 pkm->pm_address, pkm->pm_address + pkm->pm_size); 1907 } 1908 } 1909 } 1910 1911 /* 1912 * Log mapping information about the kernel. 1913 */ 1914 static void 1915 pmc_log_kernel_mappings(struct pmc *pm) 1916 { 1917 struct pmc_owner *po; 1918 struct pmckern_map_in *km, *kmbase; 1919 1920 MPASS(in_epoch(global_epoch_preempt) || sx_xlocked(&pmc_sx)); 1921 KASSERT(PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)), 1922 ("[pmc,%d] non-sampling PMC (%p) desires mapping information", 1923 __LINE__, (void *) pm)); 1924 1925 po = pm->pm_owner; 1926 if ((po->po_flags & PMC_PO_INITIAL_MAPPINGS_DONE) != 0) 1927 return; 1928 1929 if (PMC_TO_MODE(pm) == PMC_MODE_SS) 1930 pmc_process_allproc(pm); 1931 1932 /* 1933 * Log the current set of kernel modules. 1934 */ 1935 kmbase = linker_hwpmc_list_objects(); 1936 for (km = kmbase; km->pm_file != NULL; km++) { 1937 PMCDBG2(LOG,REG,1,"%s %p", (char *)km->pm_file, 1938 (void *)km->pm_address); 1939 pmclog_process_map_in(po, (pid_t)-1, km->pm_address, 1940 km->pm_file); 1941 } 1942 free(kmbase, M_LINKER); 1943 1944 po->po_flags |= PMC_PO_INITIAL_MAPPINGS_DONE; 1945 } 1946 1947 /* 1948 * Log the mappings for a single process. 1949 */ 1950 static void 1951 pmc_log_process_mappings(struct pmc_owner *po, struct proc *p) 1952 { 1953 vm_map_t map; 1954 vm_map_entry_t entry; 1955 vm_object_t obj, lobj, tobj; 1956 vm_offset_t last_end; 1957 vm_offset_t start_addr; 1958 struct vnode *vp, *last_vp; 1959 struct vmspace *vm; 1960 char *fullpath, *freepath; 1961 u_int last_timestamp; 1962 1963 last_vp = NULL; 1964 last_end = (vm_offset_t)0; 1965 fullpath = freepath = NULL; 1966 1967 if ((vm = vmspace_acquire_ref(p)) == NULL) 1968 return; 1969 1970 map = &vm->vm_map; 1971 vm_map_lock_read(map); 1972 VM_MAP_ENTRY_FOREACH(entry, map) { 1973 if (entry == NULL) { 1974 PMCDBG2(LOG,OPS,2, "hwpmc: vm_map entry unexpectedly " 1975 "NULL! pid=%d vm_map=%p\n", p->p_pid, map); 1976 break; 1977 } 1978 1979 /* 1980 * We only care about executable map entries. 1981 */ 1982 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0 || 1983 (entry->protection & VM_PROT_EXECUTE) == 0 || 1984 entry->object.vm_object == NULL) { 1985 continue; 1986 } 1987 1988 obj = entry->object.vm_object; 1989 VM_OBJECT_RLOCK(obj); 1990 1991 /* 1992 * Walk the backing_object list to find the base (non-shadowed) 1993 * vm_object. 1994 */ 1995 for (lobj = tobj = obj; tobj != NULL; 1996 tobj = tobj->backing_object) { 1997 if (tobj != obj) 1998 VM_OBJECT_RLOCK(tobj); 1999 if (lobj != obj) 2000 VM_OBJECT_RUNLOCK(lobj); 2001 lobj = tobj; 2002 } 2003 2004 /* 2005 * At this point lobj is the base vm_object and it is locked. 2006 */ 2007 if (lobj == NULL) { 2008 PMCDBG3(LOG,OPS,2, 2009 "hwpmc: lobj unexpectedly NULL! pid=%d " 2010 "vm_map=%p vm_obj=%p\n", p->p_pid, map, obj); 2011 VM_OBJECT_RUNLOCK(obj); 2012 continue; 2013 } 2014 2015 vp = vm_object_vnode(lobj); 2016 if (vp == NULL) { 2017 if (lobj != obj) 2018 VM_OBJECT_RUNLOCK(lobj); 2019 VM_OBJECT_RUNLOCK(obj); 2020 continue; 2021 } 2022 2023 /* 2024 * Skip contiguous regions that point to the same vnode, so we 2025 * don't emit redundant MAP-IN directives. 2026 */ 2027 if (entry->start == last_end && vp == last_vp) { 2028 last_end = entry->end; 2029 if (lobj != obj) 2030 VM_OBJECT_RUNLOCK(lobj); 2031 VM_OBJECT_RUNLOCK(obj); 2032 continue; 2033 } 2034 2035 /* 2036 * We don't want to keep the proc's vm_map or this vm_object 2037 * locked while we walk the pathname, since vn_fullpath() can 2038 * sleep. However, if we drop the lock, it's possible for 2039 * concurrent activity to modify the vm_map list. To protect 2040 * against this, we save the vm_map timestamp before we release 2041 * the lock, and check it after we reacquire the lock below. 2042 */ 2043 start_addr = entry->start; 2044 last_end = entry->end; 2045 last_timestamp = map->timestamp; 2046 vm_map_unlock_read(map); 2047 2048 vref(vp); 2049 if (lobj != obj) 2050 VM_OBJECT_RUNLOCK(lobj); 2051 VM_OBJECT_RUNLOCK(obj); 2052 2053 freepath = NULL; 2054 pmc_getfilename(vp, &fullpath, &freepath); 2055 last_vp = vp; 2056 2057 vrele(vp); 2058 2059 vp = NULL; 2060 pmclog_process_map_in(po, p->p_pid, start_addr, fullpath); 2061 if (freepath != NULL) 2062 free(freepath, M_TEMP); 2063 2064 vm_map_lock_read(map); 2065 2066 /* 2067 * If our saved timestamp doesn't match, this means 2068 * that the vm_map was modified out from under us and 2069 * we can't trust our current "entry" pointer. Do a 2070 * new lookup for this entry. If there is no entry 2071 * for this address range, vm_map_lookup_entry() will 2072 * return the previous one, so we always want to go to 2073 * the next entry on the next loop iteration. 2074 * 2075 * There is an edge condition here that can occur if 2076 * there is no entry at or before this address. In 2077 * this situation, vm_map_lookup_entry returns 2078 * &map->header, which would cause our loop to abort 2079 * without processing the rest of the map. However, 2080 * in practice this will never happen for process 2081 * vm_map. This is because the executable's text 2082 * segment is the first mapping in the proc's address 2083 * space, and this mapping is never removed until the 2084 * process exits, so there will always be a non-header 2085 * entry at or before the requested address for 2086 * vm_map_lookup_entry to return. 2087 */ 2088 if (map->timestamp != last_timestamp) 2089 vm_map_lookup_entry(map, last_end - 1, &entry); 2090 } 2091 2092 vm_map_unlock_read(map); 2093 vmspace_free(vm); 2094 return; 2095 } 2096 2097 /* 2098 * Log mappings for all processes in the system. 2099 */ 2100 static void 2101 pmc_log_all_process_mappings(struct pmc_owner *po) 2102 { 2103 struct proc *p, *top; 2104 2105 sx_assert(&pmc_sx, SX_XLOCKED); 2106 2107 if ((p = pfind(1)) == NULL) 2108 panic("[pmc,%d] Cannot find init", __LINE__); 2109 2110 PROC_UNLOCK(p); 2111 2112 sx_slock(&proctree_lock); 2113 2114 top = p; 2115 for (;;) { 2116 pmc_log_process_mappings(po, p); 2117 if (!LIST_EMPTY(&p->p_children)) 2118 p = LIST_FIRST(&p->p_children); 2119 else for (;;) { 2120 if (p == top) 2121 goto done; 2122 if (LIST_NEXT(p, p_sibling)) { 2123 p = LIST_NEXT(p, p_sibling); 2124 break; 2125 } 2126 p = p->p_pptr; 2127 } 2128 } 2129 done: 2130 sx_sunlock(&proctree_lock); 2131 } 2132 2133 #ifdef HWPMC_DEBUG 2134 const char *pmc_hooknames[] = { 2135 /* these strings correspond to PMC_FN_* in <sys/pmckern.h> */ 2136 "", 2137 "EXEC", 2138 "CSW-IN", 2139 "CSW-OUT", 2140 "SAMPLE", 2141 "UNUSED1", 2142 "UNUSED2", 2143 "MMAP", 2144 "MUNMAP", 2145 "CALLCHAIN-NMI", 2146 "CALLCHAIN-SOFT", 2147 "SOFTSAMPLING", 2148 "THR-CREATE", 2149 "THR-EXIT", 2150 "THR-USERRET", 2151 "THR-CREATE-LOG", 2152 "THR-EXIT-LOG", 2153 "PROC-CREATE-LOG" 2154 }; 2155 #endif 2156 2157 /* 2158 * The 'hook' invoked from the kernel proper 2159 */ 2160 static int 2161 pmc_hook_handler(struct thread *td, int function, void *arg) 2162 { 2163 int cpu; 2164 2165 PMCDBG4(MOD,PMH,1, "hook td=%p func=%d \"%s\" arg=%p", td, function, 2166 pmc_hooknames[function], arg); 2167 2168 switch (function) { 2169 case PMC_FN_PROCESS_EXEC: 2170 pmc_process_exec(td, (struct pmckern_procexec *)arg); 2171 break; 2172 2173 case PMC_FN_CSW_IN: 2174 pmc_process_csw_in(td); 2175 break; 2176 2177 case PMC_FN_CSW_OUT: 2178 pmc_process_csw_out(td); 2179 break; 2180 2181 /* 2182 * Process accumulated PC samples. 2183 * 2184 * This function is expected to be called by hardclock() for 2185 * each CPU that has accumulated PC samples. 2186 * 2187 * This function is to be executed on the CPU whose samples 2188 * are being processed. 2189 */ 2190 case PMC_FN_DO_SAMPLES: 2191 /* 2192 * Clear the cpu specific bit in the CPU mask before 2193 * do the rest of the processing. If the NMI handler 2194 * gets invoked after the "atomic_clear_int()" call 2195 * below but before "pmc_process_samples()" gets 2196 * around to processing the interrupt, then we will 2197 * come back here at the next hardclock() tick (and 2198 * may find nothing to do if "pmc_process_samples()" 2199 * had already processed the interrupt). We don't 2200 * lose the interrupt sample. 2201 */ 2202 DPCPU_SET(pmc_sampled, 0); 2203 cpu = PCPU_GET(cpuid); 2204 pmc_process_samples(cpu, PMC_HR); 2205 pmc_process_samples(cpu, PMC_SR); 2206 pmc_process_samples(cpu, PMC_UR); 2207 break; 2208 2209 case PMC_FN_MMAP: 2210 pmc_process_mmap(td, (struct pmckern_map_in *)arg); 2211 break; 2212 2213 case PMC_FN_MUNMAP: 2214 MPASS(in_epoch(global_epoch_preempt) || sx_xlocked(&pmc_sx)); 2215 pmc_process_munmap(td, (struct pmckern_map_out *)arg); 2216 break; 2217 2218 case PMC_FN_PROC_CREATE_LOG: 2219 pmc_process_proccreate((struct proc *)arg); 2220 break; 2221 2222 case PMC_FN_USER_CALLCHAIN: 2223 /* 2224 * Record a call chain. 2225 */ 2226 KASSERT(td == curthread, ("[pmc,%d] td != curthread", 2227 __LINE__)); 2228 2229 pmc_capture_user_callchain(PCPU_GET(cpuid), PMC_HR, 2230 (struct trapframe *)arg); 2231 2232 KASSERT(td->td_pinned == 1, 2233 ("[pmc,%d] invalid td_pinned value", __LINE__)); 2234 sched_unpin(); /* Can migrate safely now. */ 2235 2236 td->td_pflags &= ~TDP_CALLCHAIN; 2237 break; 2238 2239 case PMC_FN_USER_CALLCHAIN_SOFT: 2240 /* 2241 * Record a call chain. 2242 */ 2243 KASSERT(td == curthread, ("[pmc,%d] td != curthread", 2244 __LINE__)); 2245 2246 cpu = PCPU_GET(cpuid); 2247 pmc_capture_user_callchain(cpu, PMC_SR, 2248 (struct trapframe *) arg); 2249 2250 KASSERT(td->td_pinned == 1, 2251 ("[pmc,%d] invalid td_pinned value", __LINE__)); 2252 2253 sched_unpin(); /* Can migrate safely now. */ 2254 2255 td->td_pflags &= ~TDP_CALLCHAIN; 2256 break; 2257 2258 case PMC_FN_SOFT_SAMPLING: 2259 /* 2260 * Call soft PMC sampling intr. 2261 */ 2262 pmc_soft_intr((struct pmckern_soft *)arg); 2263 break; 2264 2265 case PMC_FN_THR_CREATE: 2266 pmc_process_thread_add(td); 2267 pmc_process_threadcreate(td); 2268 break; 2269 2270 case PMC_FN_THR_CREATE_LOG: 2271 pmc_process_threadcreate(td); 2272 break; 2273 2274 case PMC_FN_THR_EXIT: 2275 KASSERT(td == curthread, ("[pmc,%d] td != curthread", 2276 __LINE__)); 2277 pmc_process_thread_delete(td); 2278 pmc_process_threadexit(td); 2279 break; 2280 case PMC_FN_THR_EXIT_LOG: 2281 pmc_process_threadexit(td); 2282 break; 2283 case PMC_FN_THR_USERRET: 2284 KASSERT(td == curthread, ("[pmc,%d] td != curthread", 2285 __LINE__)); 2286 pmc_process_thread_userret(td); 2287 break; 2288 default: 2289 #ifdef HWPMC_DEBUG 2290 KASSERT(0, ("[pmc,%d] unknown hook %d\n", __LINE__, function)); 2291 #endif 2292 break; 2293 } 2294 2295 return (0); 2296 } 2297 2298 /* 2299 * Allocate a 'struct pmc_owner' descriptor in the owner hash table. 2300 */ 2301 static struct pmc_owner * 2302 pmc_allocate_owner_descriptor(struct proc *p) 2303 { 2304 struct pmc_owner *po; 2305 struct pmc_ownerhash *poh; 2306 uint32_t hindex; 2307 2308 hindex = PMC_HASH_PTR(p, pmc_ownerhashmask); 2309 poh = &pmc_ownerhash[hindex]; 2310 2311 /* Allocate space for N pointers and one descriptor struct. */ 2312 po = malloc(sizeof(struct pmc_owner), M_PMC, M_WAITOK | M_ZERO); 2313 po->po_owner = p; 2314 LIST_INSERT_HEAD(poh, po, po_next); /* insert into hash table */ 2315 2316 TAILQ_INIT(&po->po_logbuffers); 2317 mtx_init(&po->po_mtx, "pmc-owner-mtx", "pmc-per-proc", MTX_SPIN); 2318 2319 PMCDBG4(OWN,ALL,1, "allocate-owner proc=%p (%d, %s) pmc-owner=%p", 2320 p, p->p_pid, p->p_comm, po); 2321 2322 return (po); 2323 } 2324 2325 static void 2326 pmc_destroy_owner_descriptor(struct pmc_owner *po) 2327 { 2328 2329 PMCDBG4(OWN,REL,1, "destroy-owner po=%p proc=%p (%d, %s)", 2330 po, po->po_owner, po->po_owner->p_pid, po->po_owner->p_comm); 2331 2332 mtx_destroy(&po->po_mtx); 2333 free(po, M_PMC); 2334 } 2335 2336 /* 2337 * Allocate a thread descriptor from the free pool. 2338 * 2339 * NOTE: This *can* return NULL. 2340 */ 2341 static struct pmc_thread * 2342 pmc_thread_descriptor_pool_alloc(void) 2343 { 2344 struct pmc_thread *pt; 2345 2346 mtx_lock_spin(&pmc_threadfreelist_mtx); 2347 if ((pt = LIST_FIRST(&pmc_threadfreelist)) != NULL) { 2348 LIST_REMOVE(pt, pt_next); 2349 pmc_threadfreelist_entries--; 2350 } 2351 mtx_unlock_spin(&pmc_threadfreelist_mtx); 2352 2353 return (pt); 2354 } 2355 2356 /* 2357 * Add a thread descriptor to the free pool. We use this instead of free() 2358 * to maintain a cache of free entries. Additionally, we can safely call 2359 * this function when we cannot call free(), such as in a critical section. 2360 */ 2361 static void 2362 pmc_thread_descriptor_pool_free(struct pmc_thread *pt) 2363 { 2364 2365 if (pt == NULL) 2366 return; 2367 2368 memset(pt, 0, THREADENTRY_SIZE); 2369 mtx_lock_spin(&pmc_threadfreelist_mtx); 2370 LIST_INSERT_HEAD(&pmc_threadfreelist, pt, pt_next); 2371 pmc_threadfreelist_entries++; 2372 if (pmc_threadfreelist_entries > pmc_threadfreelist_max) 2373 taskqueue_enqueue(taskqueue_fast, &free_task); 2374 mtx_unlock_spin(&pmc_threadfreelist_mtx); 2375 } 2376 2377 /* 2378 * An asynchronous task to manage the free list. 2379 */ 2380 static void 2381 pmc_thread_descriptor_pool_free_task(void *arg __unused, int pending __unused) 2382 { 2383 struct pmc_thread *pt; 2384 LIST_HEAD(, pmc_thread) tmplist; 2385 int delta; 2386 2387 LIST_INIT(&tmplist); 2388 2389 /* Determine what changes, if any, we need to make. */ 2390 mtx_lock_spin(&pmc_threadfreelist_mtx); 2391 delta = pmc_threadfreelist_entries - pmc_threadfreelist_max; 2392 while (delta > 0 && (pt = LIST_FIRST(&pmc_threadfreelist)) != NULL) { 2393 delta--; 2394 pmc_threadfreelist_entries--; 2395 LIST_REMOVE(pt, pt_next); 2396 LIST_INSERT_HEAD(&tmplist, pt, pt_next); 2397 } 2398 mtx_unlock_spin(&pmc_threadfreelist_mtx); 2399 2400 /* If there are entries to free, free them. */ 2401 while (!LIST_EMPTY(&tmplist)) { 2402 pt = LIST_FIRST(&tmplist); 2403 LIST_REMOVE(pt, pt_next); 2404 free(pt, M_PMC); 2405 } 2406 } 2407 2408 /* 2409 * Drain the thread free pool, freeing all allocations. 2410 */ 2411 static void 2412 pmc_thread_descriptor_pool_drain(void) 2413 { 2414 struct pmc_thread *pt, *next; 2415 2416 LIST_FOREACH_SAFE(pt, &pmc_threadfreelist, pt_next, next) { 2417 LIST_REMOVE(pt, pt_next); 2418 free(pt, M_PMC); 2419 } 2420 } 2421 2422 /* 2423 * find the descriptor corresponding to thread 'td', adding or removing it 2424 * as specified by 'mode'. 2425 * 2426 * Note that this supports additional mode flags in addition to those 2427 * supported by pmc_find_process_descriptor(): 2428 * PMC_FLAG_NOWAIT: Causes the function to not wait for mallocs. 2429 * This makes it safe to call while holding certain other locks. 2430 */ 2431 static struct pmc_thread * 2432 pmc_find_thread_descriptor(struct pmc_process *pp, struct thread *td, 2433 uint32_t mode) 2434 { 2435 struct pmc_thread *pt = NULL, *ptnew = NULL; 2436 int wait_flag; 2437 2438 KASSERT(td != NULL, ("[pmc,%d] called to add NULL td", __LINE__)); 2439 2440 /* 2441 * Pre-allocate memory in the PMC_FLAG_ALLOCATE case prior to 2442 * acquiring the lock. 2443 */ 2444 if ((mode & PMC_FLAG_ALLOCATE) != 0) { 2445 if ((ptnew = pmc_thread_descriptor_pool_alloc()) == NULL) { 2446 wait_flag = M_WAITOK; 2447 if ((mode & PMC_FLAG_NOWAIT) != 0 || 2448 in_epoch(global_epoch_preempt)) 2449 wait_flag = M_NOWAIT; 2450 2451 ptnew = malloc(THREADENTRY_SIZE, M_PMC, 2452 wait_flag | M_ZERO); 2453 } 2454 } 2455 2456 mtx_lock_spin(pp->pp_tdslock); 2457 LIST_FOREACH(pt, &pp->pp_tds, pt_next) { 2458 if (pt->pt_td == td) 2459 break; 2460 } 2461 2462 if ((mode & PMC_FLAG_REMOVE) != 0 && pt != NULL) 2463 LIST_REMOVE(pt, pt_next); 2464 2465 if ((mode & PMC_FLAG_ALLOCATE) != 0 && pt == NULL && ptnew != NULL) { 2466 pt = ptnew; 2467 ptnew = NULL; 2468 pt->pt_td = td; 2469 LIST_INSERT_HEAD(&pp->pp_tds, pt, pt_next); 2470 } 2471 2472 mtx_unlock_spin(pp->pp_tdslock); 2473 2474 if (ptnew != NULL) { 2475 free(ptnew, M_PMC); 2476 } 2477 2478 return (pt); 2479 } 2480 2481 /* 2482 * Try to add thread descriptors for each thread in a process. 2483 */ 2484 static void 2485 pmc_add_thread_descriptors_from_proc(struct proc *p, struct pmc_process *pp) 2486 { 2487 struct pmc_thread **tdlist; 2488 struct thread *curtd; 2489 int i, tdcnt, tdlistsz; 2490 2491 KASSERT(!PROC_LOCKED(p), ("[pmc,%d] proc unexpectedly locked", 2492 __LINE__)); 2493 tdcnt = 32; 2494 restart: 2495 tdlistsz = roundup2(tdcnt, 32); 2496 2497 tdcnt = 0; 2498 tdlist = malloc(sizeof(struct pmc_thread *) * tdlistsz, M_TEMP, 2499 M_WAITOK); 2500 2501 PROC_LOCK(p); 2502 FOREACH_THREAD_IN_PROC(p, curtd) 2503 tdcnt++; 2504 if (tdcnt >= tdlistsz) { 2505 PROC_UNLOCK(p); 2506 free(tdlist, M_TEMP); 2507 goto restart; 2508 } 2509 2510 /* 2511 * Try to add each thread to the list without sleeping. If unable, 2512 * add to a queue to retry after dropping the process lock. 2513 */ 2514 tdcnt = 0; 2515 FOREACH_THREAD_IN_PROC(p, curtd) { 2516 tdlist[tdcnt] = pmc_find_thread_descriptor(pp, curtd, 2517 PMC_FLAG_ALLOCATE | PMC_FLAG_NOWAIT); 2518 if (tdlist[tdcnt] == NULL) { 2519 PROC_UNLOCK(p); 2520 for (i = 0; i <= tdcnt; i++) 2521 pmc_thread_descriptor_pool_free(tdlist[i]); 2522 free(tdlist, M_TEMP); 2523 goto restart; 2524 } 2525 tdcnt++; 2526 } 2527 PROC_UNLOCK(p); 2528 free(tdlist, M_TEMP); 2529 } 2530 2531 /* 2532 * Find the descriptor corresponding to process 'p', adding or removing it 2533 * as specified by 'mode'. 2534 */ 2535 static struct pmc_process * 2536 pmc_find_process_descriptor(struct proc *p, uint32_t mode) 2537 { 2538 struct pmc_process *pp, *ppnew; 2539 struct pmc_processhash *pph; 2540 uint32_t hindex; 2541 2542 hindex = PMC_HASH_PTR(p, pmc_processhashmask); 2543 pph = &pmc_processhash[hindex]; 2544 2545 ppnew = NULL; 2546 2547 /* 2548 * Pre-allocate memory in the PMC_FLAG_ALLOCATE case since we 2549 * cannot call malloc(9) once we hold a spin lock. 2550 */ 2551 if ((mode & PMC_FLAG_ALLOCATE) != 0) 2552 ppnew = malloc(sizeof(struct pmc_process) + md->pmd_npmc * 2553 sizeof(struct pmc_targetstate), M_PMC, M_WAITOK | M_ZERO); 2554 2555 mtx_lock_spin(&pmc_processhash_mtx); 2556 LIST_FOREACH(pp, pph, pp_next) { 2557 if (pp->pp_proc == p) 2558 break; 2559 } 2560 2561 if ((mode & PMC_FLAG_REMOVE) != 0 && pp != NULL) 2562 LIST_REMOVE(pp, pp_next); 2563 2564 if ((mode & PMC_FLAG_ALLOCATE) != 0 && pp == NULL && ppnew != NULL) { 2565 ppnew->pp_proc = p; 2566 LIST_INIT(&ppnew->pp_tds); 2567 ppnew->pp_tdslock = mtx_pool_find(pmc_mtxpool, ppnew); 2568 LIST_INSERT_HEAD(pph, ppnew, pp_next); 2569 mtx_unlock_spin(&pmc_processhash_mtx); 2570 pp = ppnew; 2571 ppnew = NULL; 2572 2573 /* Add thread descriptors for this process' current threads. */ 2574 pmc_add_thread_descriptors_from_proc(p, pp); 2575 } else 2576 mtx_unlock_spin(&pmc_processhash_mtx); 2577 2578 if (ppnew != NULL) 2579 free(ppnew, M_PMC); 2580 return (pp); 2581 } 2582 2583 /* 2584 * Remove a process descriptor from the process hash table. 2585 */ 2586 static void 2587 pmc_remove_process_descriptor(struct pmc_process *pp) 2588 { 2589 KASSERT(pp->pp_refcnt == 0, 2590 ("[pmc,%d] Removing process descriptor %p with count %d", 2591 __LINE__, pp, pp->pp_refcnt)); 2592 2593 mtx_lock_spin(&pmc_processhash_mtx); 2594 LIST_REMOVE(pp, pp_next); 2595 mtx_unlock_spin(&pmc_processhash_mtx); 2596 } 2597 2598 /* 2599 * Destroy a process descriptor. 2600 */ 2601 static void 2602 pmc_destroy_process_descriptor(struct pmc_process *pp) 2603 { 2604 struct pmc_thread *pmc_td; 2605 2606 while ((pmc_td = LIST_FIRST(&pp->pp_tds)) != NULL) { 2607 LIST_REMOVE(pmc_td, pt_next); 2608 pmc_thread_descriptor_pool_free(pmc_td); 2609 } 2610 free(pp, M_PMC); 2611 } 2612 2613 /* 2614 * Find an owner descriptor corresponding to proc 'p'. 2615 */ 2616 static struct pmc_owner * 2617 pmc_find_owner_descriptor(struct proc *p) 2618 { 2619 struct pmc_owner *po; 2620 struct pmc_ownerhash *poh; 2621 uint32_t hindex; 2622 2623 hindex = PMC_HASH_PTR(p, pmc_ownerhashmask); 2624 poh = &pmc_ownerhash[hindex]; 2625 2626 po = NULL; 2627 LIST_FOREACH(po, poh, po_next) { 2628 if (po->po_owner == p) 2629 break; 2630 } 2631 2632 PMCDBG5(OWN,FND,1, "find-owner proc=%p (%d, %s) hindex=0x%x -> " 2633 "pmc-owner=%p", p, p->p_pid, p->p_comm, hindex, po); 2634 2635 return (po); 2636 } 2637 2638 /* 2639 * Allocate a pmc descriptor and initialize its fields. 2640 */ 2641 static struct pmc * 2642 pmc_allocate_pmc_descriptor(void) 2643 { 2644 struct pmc *pmc; 2645 2646 pmc = malloc(sizeof(struct pmc), M_PMC, M_WAITOK | M_ZERO); 2647 pmc->pm_runcount = counter_u64_alloc(M_WAITOK); 2648 pmc->pm_pcpu_state = malloc(sizeof(struct pmc_pcpu_state) * mp_ncpus, 2649 M_PMC, M_WAITOK | M_ZERO); 2650 PMCDBG1(PMC,ALL,1, "allocate-pmc -> pmc=%p", pmc); 2651 2652 return (pmc); 2653 } 2654 2655 /* 2656 * Destroy a pmc descriptor. 2657 */ 2658 static void 2659 pmc_destroy_pmc_descriptor(struct pmc *pm) 2660 { 2661 2662 KASSERT(pm->pm_state == PMC_STATE_DELETED || 2663 pm->pm_state == PMC_STATE_FREE, 2664 ("[pmc,%d] destroying non-deleted PMC", __LINE__)); 2665 KASSERT(LIST_EMPTY(&pm->pm_targets), 2666 ("[pmc,%d] destroying pmc with targets", __LINE__)); 2667 KASSERT(pm->pm_owner == NULL, 2668 ("[pmc,%d] destroying pmc attached to an owner", __LINE__)); 2669 KASSERT(counter_u64_fetch(pm->pm_runcount) == 0, 2670 ("[pmc,%d] pmc has non-zero run count %ju", __LINE__, 2671 (uintmax_t)counter_u64_fetch(pm->pm_runcount))); 2672 2673 counter_u64_free(pm->pm_runcount); 2674 free(pm->pm_pcpu_state, M_PMC); 2675 free(pm, M_PMC); 2676 } 2677 2678 static void 2679 pmc_wait_for_pmc_idle(struct pmc *pm) 2680 { 2681 #ifdef INVARIANTS 2682 volatile int maxloop; 2683 2684 maxloop = 100 * pmc_cpu_max(); 2685 #endif 2686 /* 2687 * Loop (with a forced context switch) till the PMC's runcount 2688 * comes down to zero. 2689 */ 2690 pmclog_flush(pm->pm_owner, 1); 2691 while (counter_u64_fetch(pm->pm_runcount) > 0) { 2692 pmclog_flush(pm->pm_owner, 1); 2693 #ifdef INVARIANTS 2694 maxloop--; 2695 KASSERT(maxloop > 0, 2696 ("[pmc,%d] (ri%d, rc%ju) waiting too long for " 2697 "pmc to be free", __LINE__, PMC_TO_ROWINDEX(pm), 2698 (uintmax_t)counter_u64_fetch(pm->pm_runcount))); 2699 #endif 2700 pmc_force_context_switch(); 2701 } 2702 } 2703 2704 /* 2705 * This function does the following things: 2706 * 2707 * - detaches the PMC from hardware 2708 * - unlinks all target threads that were attached to it 2709 * - removes the PMC from its owner's list 2710 * - destroys the PMC private mutex 2711 * 2712 * Once this function completes, the given pmc pointer can be freed by 2713 * calling pmc_destroy_pmc_descriptor(). 2714 */ 2715 static void 2716 pmc_release_pmc_descriptor(struct pmc *pm) 2717 { 2718 struct pmc_binding pb; 2719 struct pmc_classdep *pcd; 2720 struct pmc_hw *phw __diagused; 2721 struct pmc_owner *po; 2722 struct pmc_process *pp; 2723 struct pmc_target *ptgt, *tmp; 2724 enum pmc_mode mode; 2725 u_int adjri, ri, cpu; 2726 2727 sx_assert(&pmc_sx, SX_XLOCKED); 2728 KASSERT(pm, ("[pmc,%d] null pmc", __LINE__)); 2729 2730 ri = PMC_TO_ROWINDEX(pm); 2731 pcd = pmc_ri_to_classdep(md, ri, &adjri); 2732 mode = PMC_TO_MODE(pm); 2733 2734 PMCDBG3(PMC,REL,1, "release-pmc pmc=%p ri=%d mode=%d", pm, ri, 2735 mode); 2736 2737 /* 2738 * First, we take the PMC off hardware. 2739 */ 2740 cpu = 0; 2741 if (PMC_IS_SYSTEM_MODE(mode)) { 2742 /* 2743 * A system mode PMC runs on a specific CPU. Switch 2744 * to this CPU and turn hardware off. 2745 */ 2746 pmc_save_cpu_binding(&pb); 2747 cpu = PMC_TO_CPU(pm); 2748 pmc_select_cpu(cpu); 2749 2750 /* switch off non-stalled CPUs */ 2751 pm->pm_pcpu_state[cpu].pps_cpustate = 0; 2752 if (pm->pm_state == PMC_STATE_RUNNING && 2753 pm->pm_pcpu_state[cpu].pps_stalled == 0) { 2754 2755 phw = pmc_pcpu[cpu]->pc_hwpmcs[ri]; 2756 2757 KASSERT(phw->phw_pmc == pm, 2758 ("[pmc, %d] pmc ptr ri(%d) hw(%p) pm(%p)", 2759 __LINE__, ri, phw->phw_pmc, pm)); 2760 PMCDBG2(PMC,REL,2, "stopping cpu=%d ri=%d", cpu, ri); 2761 2762 critical_enter(); 2763 (void)pcd->pcd_stop_pmc(cpu, adjri, pm); 2764 critical_exit(); 2765 } 2766 2767 PMCDBG2(PMC,REL,2, "decfg cpu=%d ri=%d", cpu, ri); 2768 2769 critical_enter(); 2770 (void)pcd->pcd_config_pmc(cpu, adjri, NULL); 2771 critical_exit(); 2772 2773 /* adjust the global and process count of SS mode PMCs */ 2774 if (mode == PMC_MODE_SS && pm->pm_state == PMC_STATE_RUNNING) { 2775 po = pm->pm_owner; 2776 po->po_sscount--; 2777 if (po->po_sscount == 0) { 2778 atomic_subtract_rel_int(&pmc_ss_count, 1); 2779 CK_LIST_REMOVE(po, po_ssnext); 2780 epoch_wait_preempt(global_epoch_preempt); 2781 } 2782 } 2783 pm->pm_state = PMC_STATE_DELETED; 2784 2785 pmc_restore_cpu_binding(&pb); 2786 2787 /* 2788 * We could have references to this PMC structure in the 2789 * per-cpu sample queues. Wait for the queue to drain. 2790 */ 2791 pmc_wait_for_pmc_idle(pm); 2792 2793 } else if (PMC_IS_VIRTUAL_MODE(mode)) { 2794 /* 2795 * A virtual PMC could be running on multiple CPUs at a given 2796 * instant. 2797 * 2798 * By marking its state as DELETED, we ensure that this PMC is 2799 * never further scheduled on hardware. 2800 * 2801 * Then we wait till all CPUs are done with this PMC. 2802 */ 2803 pm->pm_state = PMC_STATE_DELETED; 2804 2805 /* Wait for the PMCs runcount to come to zero. */ 2806 pmc_wait_for_pmc_idle(pm); 2807 2808 /* 2809 * At this point the PMC is off all CPUs and cannot be freshly 2810 * scheduled onto a CPU. It is now safe to unlink all targets 2811 * from this PMC. If a process-record's refcount falls to zero, 2812 * we remove it from the hash table. The module-wide SX lock 2813 * protects us from races. 2814 */ 2815 LIST_FOREACH_SAFE(ptgt, &pm->pm_targets, pt_next, tmp) { 2816 pp = ptgt->pt_process; 2817 pmc_unlink_target_process(pm, pp); /* frees 'ptgt' */ 2818 2819 PMCDBG1(PMC,REL,3, "pp->refcnt=%d", pp->pp_refcnt); 2820 2821 /* 2822 * If the target process record shows that no PMCs are 2823 * attached to it, reclaim its space. 2824 */ 2825 if (pp->pp_refcnt == 0) { 2826 pmc_remove_process_descriptor(pp); 2827 pmc_destroy_process_descriptor(pp); 2828 } 2829 } 2830 2831 cpu = curthread->td_oncpu; /* setup cpu for pmd_release() */ 2832 } 2833 2834 /* 2835 * Release any MD resources. 2836 */ 2837 (void)pcd->pcd_release_pmc(cpu, adjri, pm); 2838 2839 /* 2840 * Update row disposition. 2841 */ 2842 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) 2843 PMC_UNMARK_ROW_STANDALONE(ri); 2844 else 2845 PMC_UNMARK_ROW_THREAD(ri); 2846 2847 /* Unlink from the owner's list. */ 2848 if (pm->pm_owner != NULL) { 2849 LIST_REMOVE(pm, pm_next); 2850 pm->pm_owner = NULL; 2851 } 2852 } 2853 2854 /* 2855 * Register an owner and a pmc. 2856 */ 2857 static int 2858 pmc_register_owner(struct proc *p, struct pmc *pmc) 2859 { 2860 struct pmc_owner *po; 2861 2862 sx_assert(&pmc_sx, SX_XLOCKED); 2863 2864 if ((po = pmc_find_owner_descriptor(p)) == NULL) { 2865 if ((po = pmc_allocate_owner_descriptor(p)) == NULL) 2866 return (ENOMEM); 2867 } 2868 2869 KASSERT(pmc->pm_owner == NULL, 2870 ("[pmc,%d] attempting to own an initialized PMC", __LINE__)); 2871 pmc->pm_owner = po; 2872 2873 LIST_INSERT_HEAD(&po->po_pmcs, pmc, pm_next); 2874 2875 PROC_LOCK(p); 2876 p->p_flag |= P_HWPMC; 2877 PROC_UNLOCK(p); 2878 2879 if ((po->po_flags & PMC_PO_OWNS_LOGFILE) != 0) 2880 pmclog_process_pmcallocate(pmc); 2881 2882 PMCDBG2(PMC,REG,1, "register-owner pmc-owner=%p pmc=%p", 2883 po, pmc); 2884 2885 return (0); 2886 } 2887 2888 /* 2889 * Return the current row disposition: 2890 * == 0 => FREE 2891 * > 0 => PROCESS MODE 2892 * < 0 => SYSTEM MODE 2893 */ 2894 int 2895 pmc_getrowdisp(int ri) 2896 { 2897 return (pmc_pmcdisp[ri]); 2898 } 2899 2900 /* 2901 * Check if a PMC at row index 'ri' can be allocated to the current 2902 * process. 2903 * 2904 * Allocation can fail if: 2905 * - the current process is already being profiled by a PMC at index 'ri', 2906 * attached to it via OP_PMCATTACH. 2907 * - the current process has already allocated a PMC at index 'ri' 2908 * via OP_ALLOCATE. 2909 */ 2910 static bool 2911 pmc_can_allocate_rowindex(struct proc *p, unsigned int ri, int cpu) 2912 { 2913 struct pmc *pm; 2914 struct pmc_owner *po; 2915 struct pmc_process *pp; 2916 enum pmc_mode mode; 2917 2918 PMCDBG5(PMC,ALR,1, "can-allocate-rowindex proc=%p (%d, %s) ri=%d " 2919 "cpu=%d", p, p->p_pid, p->p_comm, ri, cpu); 2920 2921 /* 2922 * We shouldn't have already allocated a process-mode PMC at 2923 * row index 'ri'. 2924 * 2925 * We shouldn't have allocated a system-wide PMC on the same 2926 * CPU and same RI. 2927 */ 2928 if ((po = pmc_find_owner_descriptor(p)) != NULL) { 2929 LIST_FOREACH(pm, &po->po_pmcs, pm_next) { 2930 if (PMC_TO_ROWINDEX(pm) == ri) { 2931 mode = PMC_TO_MODE(pm); 2932 if (PMC_IS_VIRTUAL_MODE(mode)) 2933 return (false); 2934 if (PMC_IS_SYSTEM_MODE(mode) && 2935 PMC_TO_CPU(pm) == cpu) 2936 return (false); 2937 } 2938 } 2939 } 2940 2941 /* 2942 * We also shouldn't be the target of any PMC at this index 2943 * since otherwise a PMC_ATTACH to ourselves will fail. 2944 */ 2945 if ((pp = pmc_find_process_descriptor(p, 0)) != NULL) 2946 if (pp->pp_pmcs[ri].pp_pmc != NULL) 2947 return (false); 2948 2949 PMCDBG4(PMC,ALR,2, "can-allocate-rowindex proc=%p (%d, %s) ri=%d ok", 2950 p, p->p_pid, p->p_comm, ri); 2951 return (true); 2952 } 2953 2954 /* 2955 * Check if a given PMC at row index 'ri' can be currently used in 2956 * mode 'mode'. 2957 */ 2958 static bool 2959 pmc_can_allocate_row(int ri, enum pmc_mode mode) 2960 { 2961 enum pmc_disp disp; 2962 2963 sx_assert(&pmc_sx, SX_XLOCKED); 2964 2965 PMCDBG2(PMC,ALR,1, "can-allocate-row ri=%d mode=%d", ri, mode); 2966 2967 if (PMC_IS_SYSTEM_MODE(mode)) 2968 disp = PMC_DISP_STANDALONE; 2969 else 2970 disp = PMC_DISP_THREAD; 2971 2972 /* 2973 * check disposition for PMC row 'ri': 2974 * 2975 * Expected disposition Row-disposition Result 2976 * 2977 * STANDALONE STANDALONE or FREE proceed 2978 * STANDALONE THREAD fail 2979 * THREAD THREAD or FREE proceed 2980 * THREAD STANDALONE fail 2981 */ 2982 if (!PMC_ROW_DISP_IS_FREE(ri) && 2983 !(disp == PMC_DISP_THREAD && PMC_ROW_DISP_IS_THREAD(ri)) && 2984 !(disp == PMC_DISP_STANDALONE && PMC_ROW_DISP_IS_STANDALONE(ri))) 2985 return (false); 2986 2987 /* 2988 * All OK 2989 */ 2990 PMCDBG2(PMC,ALR,2, "can-allocate-row ri=%d mode=%d ok", ri, mode); 2991 return (true); 2992 } 2993 2994 /* 2995 * Find a PMC descriptor with user handle 'pmcid' for thread 'td'. 2996 */ 2997 static struct pmc * 2998 pmc_find_pmc_descriptor_in_process(struct pmc_owner *po, pmc_id_t pmcid) 2999 { 3000 struct pmc *pm; 3001 3002 KASSERT(PMC_ID_TO_ROWINDEX(pmcid) < md->pmd_npmc, 3003 ("[pmc,%d] Illegal pmc index %d (max %d)", __LINE__, 3004 PMC_ID_TO_ROWINDEX(pmcid), md->pmd_npmc)); 3005 3006 LIST_FOREACH(pm, &po->po_pmcs, pm_next) { 3007 if (pm->pm_id == pmcid) 3008 return (pm); 3009 } 3010 3011 return (NULL); 3012 } 3013 3014 static int 3015 pmc_find_pmc(pmc_id_t pmcid, struct pmc **pmc) 3016 { 3017 struct pmc *pm, *opm; 3018 struct pmc_owner *po; 3019 struct pmc_process *pp; 3020 3021 PMCDBG1(PMC,FND,1, "find-pmc id=%d", pmcid); 3022 if (PMC_ID_TO_ROWINDEX(pmcid) >= md->pmd_npmc) 3023 return (EINVAL); 3024 3025 if ((po = pmc_find_owner_descriptor(curthread->td_proc)) == NULL) { 3026 /* 3027 * In case of PMC_F_DESCENDANTS child processes we will not find 3028 * the current process in the owners hash list. Find the owner 3029 * process first and from there lookup the po. 3030 */ 3031 pp = pmc_find_process_descriptor(curthread->td_proc, 3032 PMC_FLAG_NONE); 3033 if (pp == NULL) 3034 return (ESRCH); 3035 opm = pp->pp_pmcs[PMC_ID_TO_ROWINDEX(pmcid)].pp_pmc; 3036 if (opm == NULL) 3037 return (ESRCH); 3038 if ((opm->pm_flags & 3039 (PMC_F_ATTACHED_TO_OWNER | PMC_F_DESCENDANTS)) != 3040 (PMC_F_ATTACHED_TO_OWNER | PMC_F_DESCENDANTS)) 3041 return (ESRCH); 3042 3043 po = opm->pm_owner; 3044 } 3045 3046 if ((pm = pmc_find_pmc_descriptor_in_process(po, pmcid)) == NULL) 3047 return (EINVAL); 3048 3049 PMCDBG2(PMC,FND,2, "find-pmc id=%d -> pmc=%p", pmcid, pm); 3050 3051 *pmc = pm; 3052 return (0); 3053 } 3054 3055 /* 3056 * Start a PMC. 3057 */ 3058 static int 3059 pmc_start(struct pmc *pm) 3060 { 3061 struct pmc_binding pb; 3062 struct pmc_classdep *pcd; 3063 struct pmc_owner *po; 3064 pmc_value_t v; 3065 enum pmc_mode mode; 3066 int adjri, error, cpu, ri; 3067 3068 KASSERT(pm != NULL, 3069 ("[pmc,%d] null pm", __LINE__)); 3070 3071 mode = PMC_TO_MODE(pm); 3072 ri = PMC_TO_ROWINDEX(pm); 3073 pcd = pmc_ri_to_classdep(md, ri, &adjri); 3074 3075 error = 0; 3076 po = pm->pm_owner; 3077 3078 PMCDBG3(PMC,OPS,1, "start pmc=%p mode=%d ri=%d", pm, mode, ri); 3079 3080 po = pm->pm_owner; 3081 3082 /* 3083 * Disallow PMCSTART if a logfile is required but has not been 3084 * configured yet. 3085 */ 3086 if ((pm->pm_flags & PMC_F_NEEDS_LOGFILE) != 0 && 3087 (po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) 3088 return (EDOOFUS); /* programming error */ 3089 3090 /* 3091 * If this is a sampling mode PMC, log mapping information for 3092 * the kernel modules that are currently loaded. 3093 */ 3094 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 3095 pmc_log_kernel_mappings(pm); 3096 3097 if (PMC_IS_VIRTUAL_MODE(mode)) { 3098 /* 3099 * If a PMCATTACH has never been done on this PMC, 3100 * attach it to its owner process. 3101 */ 3102 if (LIST_EMPTY(&pm->pm_targets)) { 3103 error = (pm->pm_flags & PMC_F_ATTACH_DONE) != 0 ? 3104 ESRCH : pmc_attach_process(po->po_owner, pm); 3105 } 3106 3107 /* 3108 * If the PMC is attached to its owner, then force a context 3109 * switch to ensure that the MD state gets set correctly. 3110 */ 3111 if (error == 0) { 3112 pm->pm_state = PMC_STATE_RUNNING; 3113 if ((pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) != 0) 3114 pmc_force_context_switch(); 3115 } 3116 3117 return (error); 3118 } 3119 3120 /* 3121 * A system-wide PMC. 3122 * 3123 * Add the owner to the global list if this is a system-wide 3124 * sampling PMC. 3125 */ 3126 if (mode == PMC_MODE_SS) { 3127 /* 3128 * Log mapping information for all existing processes in the 3129 * system. Subsequent mappings are logged as they happen; 3130 * see pmc_process_mmap(). 3131 */ 3132 if (po->po_logprocmaps == 0) { 3133 pmc_log_all_process_mappings(po); 3134 po->po_logprocmaps = 1; 3135 } 3136 po->po_sscount++; 3137 if (po->po_sscount == 1) { 3138 atomic_add_rel_int(&pmc_ss_count, 1); 3139 CK_LIST_INSERT_HEAD(&pmc_ss_owners, po, po_ssnext); 3140 PMCDBG1(PMC,OPS,1, "po=%p in global list", po); 3141 } 3142 } 3143 3144 /* 3145 * Move to the CPU associated with this 3146 * PMC, and start the hardware. 3147 */ 3148 pmc_save_cpu_binding(&pb); 3149 cpu = PMC_TO_CPU(pm); 3150 if (!pmc_cpu_is_active(cpu)) 3151 return (ENXIO); 3152 pmc_select_cpu(cpu); 3153 3154 /* 3155 * global PMCs are configured at allocation time 3156 * so write out the initial value and start the PMC. 3157 */ 3158 pm->pm_state = PMC_STATE_RUNNING; 3159 3160 critical_enter(); 3161 v = PMC_IS_SAMPLING_MODE(mode) ? pm->pm_sc.pm_reloadcount : 3162 pm->pm_sc.pm_initial; 3163 if ((error = pcd->pcd_write_pmc(cpu, adjri, pm, v)) == 0) { 3164 /* If a sampling mode PMC, reset stalled state. */ 3165 if (PMC_IS_SAMPLING_MODE(mode)) 3166 pm->pm_pcpu_state[cpu].pps_stalled = 0; 3167 3168 /* Indicate that we desire this to run. Start it. */ 3169 pm->pm_pcpu_state[cpu].pps_cpustate = 1; 3170 error = pcd->pcd_start_pmc(cpu, adjri, pm); 3171 } 3172 critical_exit(); 3173 3174 pmc_restore_cpu_binding(&pb); 3175 return (error); 3176 } 3177 3178 /* 3179 * Stop a PMC. 3180 */ 3181 static int 3182 pmc_stop(struct pmc *pm) 3183 { 3184 struct pmc_binding pb; 3185 struct pmc_classdep *pcd; 3186 struct pmc_owner *po; 3187 int adjri, cpu, error, ri; 3188 3189 KASSERT(pm != NULL, ("[pmc,%d] null pmc", __LINE__)); 3190 3191 PMCDBG3(PMC,OPS,1, "stop pmc=%p mode=%d ri=%d", pm, PMC_TO_MODE(pm), 3192 PMC_TO_ROWINDEX(pm)); 3193 3194 pm->pm_state = PMC_STATE_STOPPED; 3195 3196 /* 3197 * If the PMC is a virtual mode one, changing the state to non-RUNNING 3198 * is enough to ensure that the PMC never gets scheduled. 3199 * 3200 * If this PMC is current running on a CPU, then it will handled 3201 * correctly at the time its target process is context switched out. 3202 */ 3203 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) 3204 return (0); 3205 3206 /* 3207 * A system-mode PMC. Move to the CPU associated with this PMC, and 3208 * stop the hardware. We update the 'initial count' so that a 3209 * subsequent PMCSTART will resume counting from the current hardware 3210 * count. 3211 */ 3212 pmc_save_cpu_binding(&pb); 3213 3214 cpu = PMC_TO_CPU(pm); 3215 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 3216 ("[pmc,%d] illegal cpu=%d", __LINE__, cpu)); 3217 if (!pmc_cpu_is_active(cpu)) 3218 return (ENXIO); 3219 3220 pmc_select_cpu(cpu); 3221 3222 ri = PMC_TO_ROWINDEX(pm); 3223 pcd = pmc_ri_to_classdep(md, ri, &adjri); 3224 3225 pm->pm_pcpu_state[cpu].pps_cpustate = 0; 3226 critical_enter(); 3227 if ((error = pcd->pcd_stop_pmc(cpu, adjri, pm)) == 0) { 3228 error = pcd->pcd_read_pmc(cpu, adjri, pm, 3229 &pm->pm_sc.pm_initial); 3230 } 3231 critical_exit(); 3232 3233 pmc_restore_cpu_binding(&pb); 3234 3235 /* Remove this owner from the global list of SS PMC owners. */ 3236 po = pm->pm_owner; 3237 if (PMC_TO_MODE(pm) == PMC_MODE_SS) { 3238 po->po_sscount--; 3239 if (po->po_sscount == 0) { 3240 atomic_subtract_rel_int(&pmc_ss_count, 1); 3241 CK_LIST_REMOVE(po, po_ssnext); 3242 epoch_wait_preempt(global_epoch_preempt); 3243 PMCDBG1(PMC,OPS,2,"po=%p removed from global list", po); 3244 } 3245 } 3246 3247 return (error); 3248 } 3249 3250 static struct pmc_classdep * 3251 pmc_class_to_classdep(enum pmc_class class) 3252 { 3253 int n; 3254 3255 for (n = 0; n < md->pmd_nclass; n++) { 3256 if (md->pmd_classdep[n].pcd_class == class) 3257 return (&md->pmd_classdep[n]); 3258 } 3259 return (NULL); 3260 } 3261 3262 #if defined(HWPMC_DEBUG) && defined(KTR) 3263 static const char *pmc_op_to_name[] = { 3264 #undef __PMC_OP 3265 #define __PMC_OP(N, D) #N , 3266 __PMC_OPS() 3267 NULL 3268 }; 3269 #endif 3270 3271 /* 3272 * The syscall interface 3273 */ 3274 3275 #define PMC_GET_SX_XLOCK(...) do { \ 3276 sx_xlock(&pmc_sx); \ 3277 if (pmc_hook == NULL) { \ 3278 sx_xunlock(&pmc_sx); \ 3279 return __VA_ARGS__; \ 3280 } \ 3281 } while (0) 3282 3283 #define PMC_DOWNGRADE_SX() do { \ 3284 sx_downgrade(&pmc_sx); \ 3285 is_sx_downgraded = true; \ 3286 } while (0) 3287 3288 /* 3289 * Main body of PMC_OP_PMCALLOCATE. 3290 */ 3291 static int 3292 pmc_do_op_pmcallocate(struct thread *td, struct pmc_op_pmcallocate *pa) 3293 { 3294 struct proc *p; 3295 struct pmc *pmc; 3296 struct pmc_binding pb; 3297 struct pmc_classdep *pcd; 3298 struct pmc_hw *phw; 3299 enum pmc_mode mode; 3300 enum pmc_class class; 3301 uint32_t caps, flags; 3302 u_int cpu; 3303 int adjri, n; 3304 int error; 3305 3306 class = pa->pm_class; 3307 caps = pa->pm_caps; 3308 flags = pa->pm_flags; 3309 mode = pa->pm_mode; 3310 cpu = pa->pm_cpu; 3311 3312 p = td->td_proc; 3313 3314 /* Requested mode must exist. */ 3315 if ((mode != PMC_MODE_SS && mode != PMC_MODE_SC && 3316 mode != PMC_MODE_TS && mode != PMC_MODE_TC)) 3317 return (EINVAL); 3318 3319 /* Requested CPU must be valid. */ 3320 if (cpu != PMC_CPU_ANY && cpu >= pmc_cpu_max()) 3321 return (EINVAL); 3322 3323 /* 3324 * Virtual PMCs should only ask for a default CPU. 3325 * System mode PMCs need to specify a non-default CPU. 3326 */ 3327 if ((PMC_IS_VIRTUAL_MODE(mode) && cpu != PMC_CPU_ANY) || 3328 (PMC_IS_SYSTEM_MODE(mode) && cpu == PMC_CPU_ANY)) 3329 return (EINVAL); 3330 3331 /* 3332 * Check that an inactive CPU is not being asked for. 3333 */ 3334 if (PMC_IS_SYSTEM_MODE(mode) && !pmc_cpu_is_active(cpu)) 3335 return (ENXIO); 3336 3337 /* 3338 * Refuse an allocation for a system-wide PMC if this process has been 3339 * jailed, or if this process lacks super-user credentials and the 3340 * sysctl tunable 'security.bsd.unprivileged_syspmcs' is zero. 3341 */ 3342 if (PMC_IS_SYSTEM_MODE(mode)) { 3343 if (jailed(td->td_ucred)) 3344 return (EPERM); 3345 if (!pmc_unprivileged_syspmcs) { 3346 error = priv_check(td, PRIV_PMC_SYSTEM); 3347 if (error != 0) 3348 return (error); 3349 } 3350 } 3351 3352 /* 3353 * Look for valid values for 'pm_flags'. 3354 */ 3355 if ((flags & ~(PMC_F_DESCENDANTS | PMC_F_LOG_PROCCSW | 3356 PMC_F_LOG_PROCEXIT | PMC_F_CALLCHAIN | PMC_F_USERCALLCHAIN | 3357 PMC_F_EV_PMU)) != 0) 3358 return (EINVAL); 3359 3360 /* PMC_F_USERCALLCHAIN is only valid with PMC_F_CALLCHAIN. */ 3361 if ((flags & (PMC_F_CALLCHAIN | PMC_F_USERCALLCHAIN)) == 3362 PMC_F_USERCALLCHAIN) 3363 return (EINVAL); 3364 3365 /* PMC_F_USERCALLCHAIN is only valid for sampling mode. */ 3366 if ((flags & PMC_F_USERCALLCHAIN) != 0 && mode != PMC_MODE_TS && 3367 mode != PMC_MODE_SS) 3368 return (EINVAL); 3369 3370 /* Process logging options are not allowed for system PMCs. */ 3371 if (PMC_IS_SYSTEM_MODE(mode) && 3372 (flags & (PMC_F_LOG_PROCCSW | PMC_F_LOG_PROCEXIT)) != 0) 3373 return (EINVAL); 3374 3375 /* 3376 * All sampling mode PMCs need to be able to interrupt the CPU. 3377 */ 3378 if (PMC_IS_SAMPLING_MODE(mode)) 3379 caps |= PMC_CAP_INTERRUPT; 3380 3381 /* A valid class specifier should have been passed in. */ 3382 pcd = pmc_class_to_classdep(class); 3383 if (pcd == NULL) 3384 return (EINVAL); 3385 3386 /* The requested PMC capabilities should be feasible. */ 3387 if ((pcd->pcd_caps & caps) != caps) 3388 return (EOPNOTSUPP); 3389 3390 PMCDBG4(PMC,ALL,2, "event=%d caps=0x%x mode=%d cpu=%d", pa->pm_ev, 3391 caps, mode, cpu); 3392 3393 pmc = pmc_allocate_pmc_descriptor(); 3394 pmc->pm_id = PMC_ID_MAKE_ID(cpu, pa->pm_mode, class, PMC_ID_INVALID); 3395 pmc->pm_event = pa->pm_ev; 3396 pmc->pm_state = PMC_STATE_FREE; 3397 pmc->pm_caps = caps; 3398 pmc->pm_flags = flags; 3399 3400 /* XXX set lower bound on sampling for process counters */ 3401 if (PMC_IS_SAMPLING_MODE(mode)) { 3402 /* 3403 * Don't permit requested sample rate to be less than 3404 * pmc_mincount. 3405 */ 3406 if (pa->pm_count < MAX(1, pmc_mincount)) 3407 log(LOG_WARNING, "pmcallocate: passed sample " 3408 "rate %ju - setting to %u\n", 3409 (uintmax_t)pa->pm_count, 3410 MAX(1, pmc_mincount)); 3411 pmc->pm_sc.pm_reloadcount = MAX(MAX(1, pmc_mincount), 3412 pa->pm_count); 3413 } else 3414 pmc->pm_sc.pm_initial = pa->pm_count; 3415 3416 /* switch thread to CPU 'cpu' */ 3417 pmc_save_cpu_binding(&pb); 3418 3419 #define PMC_IS_SHAREABLE_PMC(cpu, n) \ 3420 (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_state & \ 3421 PMC_PHW_FLAG_IS_SHAREABLE) 3422 #define PMC_IS_UNALLOCATED(cpu, n) \ 3423 (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_pmc == NULL) 3424 3425 if (PMC_IS_SYSTEM_MODE(mode)) { 3426 pmc_select_cpu(cpu); 3427 for (n = pcd->pcd_ri; n < md->pmd_npmc; n++) { 3428 pcd = pmc_ri_to_classdep(md, n, &adjri); 3429 3430 if (!pmc_can_allocate_row(n, mode) || 3431 !pmc_can_allocate_rowindex(p, n, cpu)) 3432 continue; 3433 if (!PMC_IS_UNALLOCATED(cpu, n) && 3434 !PMC_IS_SHAREABLE_PMC(cpu, n)) 3435 continue; 3436 3437 if (pcd->pcd_allocate_pmc(cpu, adjri, pmc, pa) == 0) { 3438 /* Success. */ 3439 break; 3440 } 3441 } 3442 } else { 3443 /* Process virtual mode */ 3444 for (n = pcd->pcd_ri; n < md->pmd_npmc; n++) { 3445 pcd = pmc_ri_to_classdep(md, n, &adjri); 3446 3447 if (!pmc_can_allocate_row(n, mode) || 3448 !pmc_can_allocate_rowindex(p, n, PMC_CPU_ANY)) 3449 continue; 3450 3451 if (pcd->pcd_allocate_pmc(td->td_oncpu, adjri, pmc, 3452 pa) == 0) { 3453 /* Success. */ 3454 break; 3455 } 3456 } 3457 } 3458 3459 #undef PMC_IS_UNALLOCATED 3460 #undef PMC_IS_SHAREABLE_PMC 3461 3462 pmc_restore_cpu_binding(&pb); 3463 3464 if (n == md->pmd_npmc) { 3465 pmc_destroy_pmc_descriptor(pmc); 3466 return (EINVAL); 3467 } 3468 3469 /* Fill in the correct value in the ID field. */ 3470 pmc->pm_id = PMC_ID_MAKE_ID(cpu, mode, class, n); 3471 3472 PMCDBG5(PMC,ALL,2, "ev=%d class=%d mode=%d n=%d -> pmcid=%x", 3473 pmc->pm_event, class, mode, n, pmc->pm_id); 3474 3475 /* Process mode PMCs with logging enabled need log files. */ 3476 if ((pmc->pm_flags & (PMC_F_LOG_PROCEXIT | PMC_F_LOG_PROCCSW)) != 0) 3477 pmc->pm_flags |= PMC_F_NEEDS_LOGFILE; 3478 3479 /* All system mode sampling PMCs require a log file. */ 3480 if (PMC_IS_SAMPLING_MODE(mode) && PMC_IS_SYSTEM_MODE(mode)) 3481 pmc->pm_flags |= PMC_F_NEEDS_LOGFILE; 3482 3483 /* 3484 * Configure global pmc's immediately. 3485 */ 3486 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pmc))) { 3487 pmc_save_cpu_binding(&pb); 3488 pmc_select_cpu(cpu); 3489 3490 phw = pmc_pcpu[cpu]->pc_hwpmcs[n]; 3491 pcd = pmc_ri_to_classdep(md, n, &adjri); 3492 3493 if ((phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0 || 3494 (error = pcd->pcd_config_pmc(cpu, adjri, pmc)) != 0) { 3495 (void)pcd->pcd_release_pmc(cpu, adjri, pmc); 3496 pmc_destroy_pmc_descriptor(pmc); 3497 pmc_restore_cpu_binding(&pb); 3498 return (EPERM); 3499 } 3500 3501 pmc_restore_cpu_binding(&pb); 3502 } 3503 3504 pmc->pm_state = PMC_STATE_ALLOCATED; 3505 pmc->pm_class = class; 3506 3507 /* 3508 * Mark row disposition. 3509 */ 3510 if (PMC_IS_SYSTEM_MODE(mode)) 3511 PMC_MARK_ROW_STANDALONE(n); 3512 else 3513 PMC_MARK_ROW_THREAD(n); 3514 3515 /* 3516 * Register this PMC with the current thread as its owner. 3517 */ 3518 error = pmc_register_owner(p, pmc); 3519 if (error != 0) { 3520 pmc_release_pmc_descriptor(pmc); 3521 pmc_destroy_pmc_descriptor(pmc); 3522 return (error); 3523 } 3524 3525 /* 3526 * Return the allocated index. 3527 */ 3528 pa->pm_pmcid = pmc->pm_id; 3529 return (0); 3530 } 3531 3532 /* 3533 * Main body of PMC_OP_PMCATTACH. 3534 */ 3535 static int 3536 pmc_do_op_pmcattach(struct thread *td, struct pmc_op_pmcattach a) 3537 { 3538 struct pmc *pm; 3539 struct proc *p; 3540 int error; 3541 3542 sx_assert(&pmc_sx, SX_XLOCKED); 3543 3544 if (a.pm_pid < 0) { 3545 return (EINVAL); 3546 } else if (a.pm_pid == 0) { 3547 a.pm_pid = td->td_proc->p_pid; 3548 } 3549 3550 error = pmc_find_pmc(a.pm_pmc, &pm); 3551 if (error != 0) 3552 return (error); 3553 3554 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) 3555 return (EINVAL); 3556 3557 /* PMCs may be (re)attached only when allocated or stopped */ 3558 if (pm->pm_state == PMC_STATE_RUNNING) { 3559 return (EBUSY); 3560 } else if (pm->pm_state != PMC_STATE_ALLOCATED && 3561 pm->pm_state != PMC_STATE_STOPPED) { 3562 return (EINVAL); 3563 } 3564 3565 /* lookup pid */ 3566 if ((p = pfind(a.pm_pid)) == NULL) 3567 return (ESRCH); 3568 3569 /* 3570 * Ignore processes that are working on exiting. 3571 */ 3572 if ((p->p_flag & P_WEXIT) != 0) { 3573 PROC_UNLOCK(p); /* pfind() returns a locked process */ 3574 return (ESRCH); 3575 } 3576 3577 /* 3578 * We are allowed to attach a PMC to a process if we can debug it. 3579 */ 3580 error = p_candebug(curthread, p); 3581 3582 PROC_UNLOCK(p); 3583 3584 if (error == 0) 3585 error = pmc_attach_process(p, pm); 3586 3587 return (error); 3588 } 3589 3590 /* 3591 * Main body of PMC_OP_PMCDETACH. 3592 */ 3593 static int 3594 pmc_do_op_pmcdetach(struct thread *td, struct pmc_op_pmcattach a) 3595 { 3596 struct pmc *pm; 3597 struct proc *p; 3598 int error; 3599 3600 if (a.pm_pid < 0) { 3601 return (EINVAL); 3602 } else if (a.pm_pid == 0) 3603 a.pm_pid = td->td_proc->p_pid; 3604 3605 error = pmc_find_pmc(a.pm_pmc, &pm); 3606 if (error != 0) 3607 return (error); 3608 3609 if ((p = pfind(a.pm_pid)) == NULL) 3610 return (ESRCH); 3611 3612 /* 3613 * Treat processes that are in the process of exiting as if they were 3614 * not present. 3615 */ 3616 if ((p->p_flag & P_WEXIT) != 0) { 3617 PROC_UNLOCK(p); 3618 return (ESRCH); 3619 } 3620 3621 PROC_UNLOCK(p); /* pfind() returns a locked process */ 3622 3623 if (error == 0) 3624 error = pmc_detach_process(p, pm); 3625 3626 return (error); 3627 } 3628 3629 /* 3630 * Main body of PMC_OP_PMCRELEASE. 3631 */ 3632 static int 3633 pmc_do_op_pmcrelease(pmc_id_t pmcid) 3634 { 3635 struct pmc_owner *po; 3636 struct pmc *pm; 3637 int error; 3638 3639 /* 3640 * Find PMC pointer for the named PMC. 3641 * 3642 * Use pmc_release_pmc_descriptor() to switch off the 3643 * PMC, remove all its target threads, and remove the 3644 * PMC from its owner's list. 3645 * 3646 * Remove the owner record if this is the last PMC 3647 * owned. 3648 * 3649 * Free up space. 3650 */ 3651 error = pmc_find_pmc(pmcid, &pm); 3652 if (error != 0) 3653 return (error); 3654 3655 po = pm->pm_owner; 3656 pmc_release_pmc_descriptor(pm); 3657 pmc_maybe_remove_owner(po); 3658 pmc_destroy_pmc_descriptor(pm); 3659 3660 return (error); 3661 } 3662 3663 /* 3664 * Main body of PMC_OP_PMCRW. 3665 */ 3666 static int 3667 pmc_do_op_pmcrw(const struct pmc_op_pmcrw *prw, pmc_value_t *valp) 3668 { 3669 struct pmc_binding pb; 3670 struct pmc_classdep *pcd; 3671 struct pmc *pm; 3672 u_int cpu, ri, adjri; 3673 int error; 3674 3675 PMCDBG2(PMC,OPS,1, "rw id=%d flags=0x%x", prw->pm_pmcid, prw->pm_flags); 3676 3677 /* Must have at least one flag set. */ 3678 if ((prw->pm_flags & (PMC_F_OLDVALUE | PMC_F_NEWVALUE)) == 0) 3679 return (EINVAL); 3680 3681 /* Locate PMC descriptor. */ 3682 error = pmc_find_pmc(prw->pm_pmcid, &pm); 3683 if (error != 0) 3684 return (error); 3685 3686 /* Can't read a PMC that hasn't been started. */ 3687 if (pm->pm_state != PMC_STATE_ALLOCATED && 3688 pm->pm_state != PMC_STATE_STOPPED && 3689 pm->pm_state != PMC_STATE_RUNNING) 3690 return (EINVAL); 3691 3692 /* Writing a new value is allowed only for 'STOPPED' PMCs. */ 3693 if (pm->pm_state == PMC_STATE_RUNNING && 3694 (prw->pm_flags & PMC_F_NEWVALUE) != 0) 3695 return (EBUSY); 3696 3697 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) { 3698 /* 3699 * If this PMC is attached to its owner (i.e., the process 3700 * requesting this operation) and is running, then attempt to 3701 * get an upto-date reading from hardware for a READ. Writes 3702 * are only allowed when the PMC is stopped, so only update the 3703 * saved value field. 3704 * 3705 * If the PMC is not running, or is not attached to its owner, 3706 * read/write to the savedvalue field. 3707 */ 3708 3709 ri = PMC_TO_ROWINDEX(pm); 3710 pcd = pmc_ri_to_classdep(md, ri, &adjri); 3711 3712 mtx_pool_lock_spin(pmc_mtxpool, pm); 3713 cpu = curthread->td_oncpu; 3714 3715 if ((prw->pm_flags & PMC_F_OLDVALUE) != 0) { 3716 if ((pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) && 3717 (pm->pm_state == PMC_STATE_RUNNING)) { 3718 error = (*pcd->pcd_read_pmc)(cpu, adjri, pm, 3719 valp); 3720 } else { 3721 *valp = pm->pm_gv.pm_savedvalue; 3722 } 3723 } 3724 3725 if ((prw->pm_flags & PMC_F_NEWVALUE) != 0) 3726 pm->pm_gv.pm_savedvalue = prw->pm_value; 3727 3728 mtx_pool_unlock_spin(pmc_mtxpool, pm); 3729 } else { /* System mode PMCs */ 3730 cpu = PMC_TO_CPU(pm); 3731 ri = PMC_TO_ROWINDEX(pm); 3732 pcd = pmc_ri_to_classdep(md, ri, &adjri); 3733 3734 if (!pmc_cpu_is_active(cpu)) 3735 return (ENXIO); 3736 3737 /* Move this thread to CPU 'cpu'. */ 3738 pmc_save_cpu_binding(&pb); 3739 pmc_select_cpu(cpu); 3740 critical_enter(); 3741 3742 /* Save old value. */ 3743 if ((prw->pm_flags & PMC_F_OLDVALUE) != 0) 3744 error = (*pcd->pcd_read_pmc)(cpu, adjri, pm, valp); 3745 3746 /* Write out new value. */ 3747 if (error == 0 && (prw->pm_flags & PMC_F_NEWVALUE) != 0) 3748 error = (*pcd->pcd_write_pmc)(cpu, adjri, pm, 3749 prw->pm_value); 3750 3751 critical_exit(); 3752 pmc_restore_cpu_binding(&pb); 3753 if (error != 0) 3754 return (error); 3755 } 3756 3757 #ifdef HWPMC_DEBUG 3758 if ((prw->pm_flags & PMC_F_NEWVALUE) != 0) 3759 PMCDBG3(PMC,OPS,2, "rw id=%d new %jx -> old %jx", 3760 ri, prw->pm_value, *valp); 3761 else 3762 PMCDBG2(PMC,OPS,2, "rw id=%d -> old %jx", ri, *valp); 3763 #endif 3764 return (error); 3765 } 3766 3767 static int 3768 pmc_syscall_handler(struct thread *td, void *syscall_args) 3769 { 3770 struct pmc_syscall_args *c; 3771 void *pmclog_proc_handle; 3772 void *arg; 3773 int error, op; 3774 bool is_sx_downgraded; 3775 3776 c = (struct pmc_syscall_args *)syscall_args; 3777 op = c->pmop_code; 3778 arg = c->pmop_data; 3779 3780 /* PMC isn't set up yet */ 3781 if (pmc_hook == NULL) 3782 return (EINVAL); 3783 3784 if (op == PMC_OP_CONFIGURELOG) { 3785 /* 3786 * We cannot create the logging process inside 3787 * pmclog_configure_log() because there is a LOR 3788 * between pmc_sx and process structure locks. 3789 * Instead, pre-create the process and ignite the loop 3790 * if everything is fine, otherwise direct the process 3791 * to exit. 3792 */ 3793 error = pmclog_proc_create(td, &pmclog_proc_handle); 3794 if (error != 0) 3795 goto done_syscall; 3796 } 3797 3798 PMC_GET_SX_XLOCK(ENOSYS); 3799 is_sx_downgraded = false; 3800 PMCDBG3(MOD,PMS,1, "syscall op=%d \"%s\" arg=%p", op, 3801 pmc_op_to_name[op], arg); 3802 3803 error = 0; 3804 counter_u64_add(pmc_stats.pm_syscalls, 1); 3805 3806 switch (op) { 3807 3808 3809 /* 3810 * Configure a log file. 3811 * 3812 * XXX This OP will be reworked. 3813 */ 3814 3815 case PMC_OP_CONFIGURELOG: 3816 { 3817 struct proc *p; 3818 struct pmc *pm; 3819 struct pmc_owner *po; 3820 struct pmc_op_configurelog cl; 3821 3822 if ((error = copyin(arg, &cl, sizeof(cl))) != 0) { 3823 pmclog_proc_ignite(pmclog_proc_handle, NULL); 3824 break; 3825 } 3826 3827 /* No flags currently implemented */ 3828 if (cl.pm_flags != 0) { 3829 pmclog_proc_ignite(pmclog_proc_handle, NULL); 3830 error = EINVAL; 3831 break; 3832 } 3833 3834 /* mark this process as owning a log file */ 3835 p = td->td_proc; 3836 if ((po = pmc_find_owner_descriptor(p)) == NULL) 3837 if ((po = pmc_allocate_owner_descriptor(p)) == NULL) { 3838 pmclog_proc_ignite(pmclog_proc_handle, NULL); 3839 error = ENOMEM; 3840 break; 3841 } 3842 3843 /* 3844 * If a valid fd was passed in, try to configure that, 3845 * otherwise if 'fd' was less than zero and there was 3846 * a log file configured, flush its buffers and 3847 * de-configure it. 3848 */ 3849 if (cl.pm_logfd >= 0) { 3850 error = pmclog_configure_log(md, po, cl.pm_logfd); 3851 pmclog_proc_ignite(pmclog_proc_handle, error == 0 ? 3852 po : NULL); 3853 } else if (po->po_flags & PMC_PO_OWNS_LOGFILE) { 3854 pmclog_proc_ignite(pmclog_proc_handle, NULL); 3855 error = pmclog_close(po); 3856 if (error == 0) { 3857 LIST_FOREACH(pm, &po->po_pmcs, pm_next) 3858 if (pm->pm_flags & PMC_F_NEEDS_LOGFILE && 3859 pm->pm_state == PMC_STATE_RUNNING) 3860 pmc_stop(pm); 3861 error = pmclog_deconfigure_log(po); 3862 } 3863 } else { 3864 pmclog_proc_ignite(pmclog_proc_handle, NULL); 3865 error = EINVAL; 3866 } 3867 } 3868 break; 3869 3870 /* 3871 * Flush a log file. 3872 */ 3873 3874 case PMC_OP_FLUSHLOG: 3875 { 3876 struct pmc_owner *po; 3877 3878 sx_assert(&pmc_sx, SX_XLOCKED); 3879 3880 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 3881 error = EINVAL; 3882 break; 3883 } 3884 3885 error = pmclog_flush(po, 0); 3886 } 3887 break; 3888 3889 /* 3890 * Close a log file. 3891 */ 3892 3893 case PMC_OP_CLOSELOG: 3894 { 3895 struct pmc_owner *po; 3896 3897 sx_assert(&pmc_sx, SX_XLOCKED); 3898 3899 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 3900 error = EINVAL; 3901 break; 3902 } 3903 3904 error = pmclog_close(po); 3905 } 3906 break; 3907 3908 /* 3909 * Retrieve hardware configuration. 3910 */ 3911 3912 case PMC_OP_GETCPUINFO: /* CPU information */ 3913 { 3914 struct pmc_op_getcpuinfo gci; 3915 struct pmc_classinfo *pci; 3916 struct pmc_classdep *pcd; 3917 int cl; 3918 3919 memset(&gci, 0, sizeof(gci)); 3920 gci.pm_cputype = md->pmd_cputype; 3921 gci.pm_ncpu = pmc_cpu_max(); 3922 gci.pm_npmc = md->pmd_npmc; 3923 gci.pm_nclass = md->pmd_nclass; 3924 pci = gci.pm_classes; 3925 pcd = md->pmd_classdep; 3926 for (cl = 0; cl < md->pmd_nclass; cl++, pci++, pcd++) { 3927 pci->pm_caps = pcd->pcd_caps; 3928 pci->pm_class = pcd->pcd_class; 3929 pci->pm_width = pcd->pcd_width; 3930 pci->pm_num = pcd->pcd_num; 3931 } 3932 error = copyout(&gci, arg, sizeof(gci)); 3933 } 3934 break; 3935 3936 /* 3937 * Retrieve soft events list. 3938 */ 3939 case PMC_OP_GETDYNEVENTINFO: 3940 { 3941 enum pmc_class cl; 3942 enum pmc_event ev; 3943 struct pmc_op_getdyneventinfo *gei; 3944 struct pmc_dyn_event_descr dev; 3945 struct pmc_soft *ps; 3946 uint32_t nevent; 3947 3948 sx_assert(&pmc_sx, SX_LOCKED); 3949 3950 gei = (struct pmc_op_getdyneventinfo *) arg; 3951 3952 if ((error = copyin(&gei->pm_class, &cl, sizeof(cl))) != 0) 3953 break; 3954 3955 /* Only SOFT class is dynamic. */ 3956 if (cl != PMC_CLASS_SOFT) { 3957 error = EINVAL; 3958 break; 3959 } 3960 3961 nevent = 0; 3962 for (ev = PMC_EV_SOFT_FIRST; (int)ev <= PMC_EV_SOFT_LAST; ev++) { 3963 ps = pmc_soft_ev_acquire(ev); 3964 if (ps == NULL) 3965 continue; 3966 bcopy(&ps->ps_ev, &dev, sizeof(dev)); 3967 pmc_soft_ev_release(ps); 3968 3969 error = copyout(&dev, 3970 &gei->pm_events[nevent], 3971 sizeof(struct pmc_dyn_event_descr)); 3972 if (error != 0) 3973 break; 3974 nevent++; 3975 } 3976 if (error != 0) 3977 break; 3978 3979 error = copyout(&nevent, &gei->pm_nevent, 3980 sizeof(nevent)); 3981 } 3982 break; 3983 3984 /* 3985 * Get module statistics 3986 */ 3987 3988 case PMC_OP_GETDRIVERSTATS: 3989 { 3990 struct pmc_op_getdriverstats gms; 3991 #define CFETCH(a, b, field) a.field = counter_u64_fetch(b.field) 3992 CFETCH(gms, pmc_stats, pm_intr_ignored); 3993 CFETCH(gms, pmc_stats, pm_intr_processed); 3994 CFETCH(gms, pmc_stats, pm_intr_bufferfull); 3995 CFETCH(gms, pmc_stats, pm_syscalls); 3996 CFETCH(gms, pmc_stats, pm_syscall_errors); 3997 CFETCH(gms, pmc_stats, pm_buffer_requests); 3998 CFETCH(gms, pmc_stats, pm_buffer_requests_failed); 3999 CFETCH(gms, pmc_stats, pm_log_sweeps); 4000 #undef CFETCH 4001 error = copyout(&gms, arg, sizeof(gms)); 4002 } 4003 break; 4004 4005 4006 /* 4007 * Retrieve module version number 4008 */ 4009 4010 case PMC_OP_GETMODULEVERSION: 4011 { 4012 uint32_t cv, modv; 4013 4014 /* retrieve the client's idea of the ABI version */ 4015 if ((error = copyin(arg, &cv, sizeof(uint32_t))) != 0) 4016 break; 4017 /* don't service clients newer than our driver */ 4018 modv = PMC_VERSION; 4019 if ((cv & 0xFFFF0000) > (modv & 0xFFFF0000)) { 4020 error = EPROGMISMATCH; 4021 break; 4022 } 4023 error = copyout(&modv, arg, sizeof(int)); 4024 } 4025 break; 4026 4027 4028 /* 4029 * Retrieve the state of all the PMCs on a given 4030 * CPU. 4031 */ 4032 4033 case PMC_OP_GETPMCINFO: 4034 { 4035 int ari; 4036 struct pmc *pm; 4037 size_t pmcinfo_size; 4038 uint32_t cpu, n, npmc; 4039 struct pmc_owner *po; 4040 struct pmc_binding pb; 4041 struct pmc_classdep *pcd; 4042 struct pmc_info *p, *pmcinfo; 4043 struct pmc_op_getpmcinfo *gpi; 4044 4045 PMC_DOWNGRADE_SX(); 4046 4047 gpi = (struct pmc_op_getpmcinfo *) arg; 4048 4049 if ((error = copyin(&gpi->pm_cpu, &cpu, sizeof(cpu))) != 0) 4050 break; 4051 4052 if (cpu >= pmc_cpu_max()) { 4053 error = EINVAL; 4054 break; 4055 } 4056 4057 if (!pmc_cpu_is_active(cpu)) { 4058 error = ENXIO; 4059 break; 4060 } 4061 4062 /* switch to CPU 'cpu' */ 4063 pmc_save_cpu_binding(&pb); 4064 pmc_select_cpu(cpu); 4065 4066 npmc = md->pmd_npmc; 4067 4068 pmcinfo_size = npmc * sizeof(struct pmc_info); 4069 pmcinfo = malloc(pmcinfo_size, M_PMC, M_WAITOK | M_ZERO); 4070 4071 p = pmcinfo; 4072 4073 for (n = 0; n < md->pmd_npmc; n++, p++) { 4074 4075 pcd = pmc_ri_to_classdep(md, n, &ari); 4076 4077 KASSERT(pcd != NULL, 4078 ("[pmc,%d] null pcd ri=%d", __LINE__, n)); 4079 4080 if ((error = pcd->pcd_describe(cpu, ari, p, &pm)) != 0) 4081 break; 4082 4083 if (PMC_ROW_DISP_IS_STANDALONE(n)) 4084 p->pm_rowdisp = PMC_DISP_STANDALONE; 4085 else if (PMC_ROW_DISP_IS_THREAD(n)) 4086 p->pm_rowdisp = PMC_DISP_THREAD; 4087 else 4088 p->pm_rowdisp = PMC_DISP_FREE; 4089 4090 p->pm_ownerpid = -1; 4091 4092 if (pm == NULL) /* no PMC associated */ 4093 continue; 4094 4095 po = pm->pm_owner; 4096 4097 KASSERT(po->po_owner != NULL, 4098 ("[pmc,%d] pmc_owner had a null proc pointer", 4099 __LINE__)); 4100 4101 p->pm_ownerpid = po->po_owner->p_pid; 4102 p->pm_mode = PMC_TO_MODE(pm); 4103 p->pm_event = pm->pm_event; 4104 p->pm_flags = pm->pm_flags; 4105 4106 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 4107 p->pm_reloadcount = 4108 pm->pm_sc.pm_reloadcount; 4109 } 4110 4111 pmc_restore_cpu_binding(&pb); 4112 4113 /* now copy out the PMC info collected */ 4114 if (error == 0) 4115 error = copyout(pmcinfo, &gpi->pm_pmcs, pmcinfo_size); 4116 4117 free(pmcinfo, M_PMC); 4118 } 4119 break; 4120 4121 4122 /* 4123 * Set the administrative state of a PMC. I.e. whether 4124 * the PMC is to be used or not. 4125 */ 4126 4127 case PMC_OP_PMCADMIN: 4128 { 4129 int cpu, ri; 4130 enum pmc_state request; 4131 struct pmc_cpu *pc; 4132 struct pmc_hw *phw; 4133 struct pmc_op_pmcadmin pma; 4134 struct pmc_binding pb; 4135 4136 sx_assert(&pmc_sx, SX_XLOCKED); 4137 4138 KASSERT(td == curthread, 4139 ("[pmc,%d] td != curthread", __LINE__)); 4140 4141 error = priv_check(td, PRIV_PMC_MANAGE); 4142 if (error) 4143 break; 4144 4145 if ((error = copyin(arg, &pma, sizeof(pma))) != 0) 4146 break; 4147 4148 cpu = pma.pm_cpu; 4149 4150 if (cpu < 0 || cpu >= (int) pmc_cpu_max()) { 4151 error = EINVAL; 4152 break; 4153 } 4154 4155 if (!pmc_cpu_is_active(cpu)) { 4156 error = ENXIO; 4157 break; 4158 } 4159 4160 request = pma.pm_state; 4161 4162 if (request != PMC_STATE_DISABLED && 4163 request != PMC_STATE_FREE) { 4164 error = EINVAL; 4165 break; 4166 } 4167 4168 ri = pma.pm_pmc; /* pmc id == row index */ 4169 if (ri < 0 || ri >= (int) md->pmd_npmc) { 4170 error = EINVAL; 4171 break; 4172 } 4173 4174 /* 4175 * We can't disable a PMC with a row-index allocated 4176 * for process virtual PMCs. 4177 */ 4178 4179 if (PMC_ROW_DISP_IS_THREAD(ri) && 4180 request == PMC_STATE_DISABLED) { 4181 error = EBUSY; 4182 break; 4183 } 4184 4185 /* 4186 * otherwise, this PMC on this CPU is either free or 4187 * in system-wide mode. 4188 */ 4189 4190 pmc_save_cpu_binding(&pb); 4191 pmc_select_cpu(cpu); 4192 4193 pc = pmc_pcpu[cpu]; 4194 phw = pc->pc_hwpmcs[ri]; 4195 4196 /* 4197 * XXX do we need some kind of 'forced' disable? 4198 */ 4199 4200 if (phw->phw_pmc == NULL) { 4201 if (request == PMC_STATE_DISABLED && 4202 (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED)) { 4203 phw->phw_state &= ~PMC_PHW_FLAG_IS_ENABLED; 4204 PMC_MARK_ROW_STANDALONE(ri); 4205 } else if (request == PMC_STATE_FREE && 4206 (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0) { 4207 phw->phw_state |= PMC_PHW_FLAG_IS_ENABLED; 4208 PMC_UNMARK_ROW_STANDALONE(ri); 4209 } 4210 /* other cases are a no-op */ 4211 } else 4212 error = EBUSY; 4213 4214 pmc_restore_cpu_binding(&pb); 4215 } 4216 break; 4217 4218 4219 /* 4220 * Allocate a PMC. 4221 */ 4222 case PMC_OP_PMCALLOCATE: 4223 { 4224 struct pmc_op_pmcallocate pa; 4225 4226 error = copyin(arg, &pa, sizeof(pa)); 4227 if (error != 0) 4228 break; 4229 4230 error = pmc_do_op_pmcallocate(td, &pa); 4231 if (error != 0) 4232 break; 4233 4234 error = copyout(&pa, arg, sizeof(pa)); 4235 } 4236 break; 4237 4238 /* 4239 * Attach a PMC to a process. 4240 */ 4241 case PMC_OP_PMCATTACH: 4242 { 4243 struct pmc_op_pmcattach a; 4244 4245 error = copyin(arg, &a, sizeof(a)); 4246 if (error != 0) 4247 break; 4248 4249 error = pmc_do_op_pmcattach(td, a); 4250 } 4251 break; 4252 4253 /* 4254 * Detach an attached PMC from a process. 4255 */ 4256 case PMC_OP_PMCDETACH: 4257 { 4258 struct pmc_op_pmcattach a; 4259 4260 error = copyin(arg, &a, sizeof(a)); 4261 if (error != 0) 4262 break; 4263 4264 error = pmc_do_op_pmcdetach(td, a); 4265 } 4266 break; 4267 4268 4269 /* 4270 * Retrieve the MSR number associated with the counter 4271 * 'pmc_id'. This allows processes to directly use RDPMC 4272 * instructions to read their PMCs, without the overhead of a 4273 * system call. 4274 */ 4275 4276 case PMC_OP_PMCGETMSR: 4277 { 4278 int adjri, ri; 4279 struct pmc *pm; 4280 struct pmc_target *pt; 4281 struct pmc_op_getmsr gm; 4282 struct pmc_classdep *pcd; 4283 4284 PMC_DOWNGRADE_SX(); 4285 4286 if ((error = copyin(arg, &gm, sizeof(gm))) != 0) 4287 break; 4288 4289 if ((error = pmc_find_pmc(gm.pm_pmcid, &pm)) != 0) 4290 break; 4291 4292 /* 4293 * The allocated PMC has to be a process virtual PMC, 4294 * i.e., of type MODE_T[CS]. Global PMCs can only be 4295 * read using the PMCREAD operation since they may be 4296 * allocated on a different CPU than the one we could 4297 * be running on at the time of the RDPMC instruction. 4298 * 4299 * The GETMSR operation is not allowed for PMCs that 4300 * are inherited across processes. 4301 */ 4302 4303 if (!PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)) || 4304 (pm->pm_flags & PMC_F_DESCENDANTS)) { 4305 error = EINVAL; 4306 break; 4307 } 4308 4309 /* 4310 * It only makes sense to use a RDPMC (or its 4311 * equivalent instruction on non-x86 architectures) on 4312 * a process that has allocated and attached a PMC to 4313 * itself. Conversely the PMC is only allowed to have 4314 * one process attached to it -- its owner. 4315 */ 4316 4317 if ((pt = LIST_FIRST(&pm->pm_targets)) == NULL || 4318 LIST_NEXT(pt, pt_next) != NULL || 4319 pt->pt_process->pp_proc != pm->pm_owner->po_owner) { 4320 error = EINVAL; 4321 break; 4322 } 4323 4324 ri = PMC_TO_ROWINDEX(pm); 4325 pcd = pmc_ri_to_classdep(md, ri, &adjri); 4326 4327 /* PMC class has no 'GETMSR' support */ 4328 if (pcd->pcd_get_msr == NULL) { 4329 error = ENOSYS; 4330 break; 4331 } 4332 4333 if ((error = (*pcd->pcd_get_msr)(adjri, &gm.pm_msr)) < 0) 4334 break; 4335 4336 if ((error = copyout(&gm, arg, sizeof(gm))) < 0) 4337 break; 4338 4339 /* 4340 * Mark our process as using MSRs. Update machine 4341 * state using a forced context switch. 4342 */ 4343 4344 pt->pt_process->pp_flags |= PMC_PP_ENABLE_MSR_ACCESS; 4345 pmc_force_context_switch(); 4346 4347 } 4348 break; 4349 4350 /* 4351 * Release an allocated PMC. 4352 */ 4353 case PMC_OP_PMCRELEASE: 4354 { 4355 struct pmc_op_simple sp; 4356 4357 error = copyin(arg, &sp, sizeof(sp)); 4358 if (error != 0) 4359 break; 4360 4361 error = pmc_do_op_pmcrelease(sp.pm_pmcid); 4362 } 4363 break; 4364 4365 /* 4366 * Read and/or write a PMC. 4367 */ 4368 case PMC_OP_PMCRW: 4369 { 4370 struct pmc_op_pmcrw prw; 4371 struct pmc_op_pmcrw *pprw; 4372 pmc_value_t oldvalue; 4373 4374 PMC_DOWNGRADE_SX(); 4375 4376 error = copyin(arg, &prw, sizeof(prw)); 4377 if (error != 0) 4378 break; 4379 4380 error = pmc_do_op_pmcrw(&prw, &oldvalue); 4381 if (error != 0) 4382 break; 4383 4384 /* Return old value if requested. */ 4385 if ((prw.pm_flags & PMC_F_OLDVALUE) != 0) { 4386 pprw = arg; 4387 error = copyout(&oldvalue, &pprw->pm_value, 4388 sizeof(prw.pm_value)); 4389 } 4390 } 4391 break; 4392 4393 4394 /* 4395 * Set the sampling rate for a sampling mode PMC and the 4396 * initial count for a counting mode PMC. 4397 */ 4398 4399 case PMC_OP_PMCSETCOUNT: 4400 { 4401 struct pmc *pm; 4402 struct pmc_op_pmcsetcount sc; 4403 4404 PMC_DOWNGRADE_SX(); 4405 4406 if ((error = copyin(arg, &sc, sizeof(sc))) != 0) 4407 break; 4408 4409 if ((error = pmc_find_pmc(sc.pm_pmcid, &pm)) != 0) 4410 break; 4411 4412 if (pm->pm_state == PMC_STATE_RUNNING) { 4413 error = EBUSY; 4414 break; 4415 } 4416 4417 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) { 4418 /* 4419 * Don't permit requested sample rate to be 4420 * less than pmc_mincount. 4421 */ 4422 if (sc.pm_count < MAX(1, pmc_mincount)) 4423 log(LOG_WARNING, "pmcsetcount: passed sample " 4424 "rate %ju - setting to %u\n", 4425 (uintmax_t)sc.pm_count, 4426 MAX(1, pmc_mincount)); 4427 pm->pm_sc.pm_reloadcount = MAX(MAX(1, pmc_mincount), 4428 sc.pm_count); 4429 } else 4430 pm->pm_sc.pm_initial = sc.pm_count; 4431 } 4432 break; 4433 4434 4435 /* 4436 * Start a PMC. 4437 */ 4438 4439 case PMC_OP_PMCSTART: 4440 { 4441 pmc_id_t pmcid; 4442 struct pmc *pm; 4443 struct pmc_op_simple sp; 4444 4445 sx_assert(&pmc_sx, SX_XLOCKED); 4446 4447 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 4448 break; 4449 4450 pmcid = sp.pm_pmcid; 4451 4452 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 4453 break; 4454 4455 KASSERT(pmcid == pm->pm_id, 4456 ("[pmc,%d] pmcid %x != id %x", __LINE__, 4457 pm->pm_id, pmcid)); 4458 4459 if (pm->pm_state == PMC_STATE_RUNNING) /* already running */ 4460 break; 4461 else if (pm->pm_state != PMC_STATE_STOPPED && 4462 pm->pm_state != PMC_STATE_ALLOCATED) { 4463 error = EINVAL; 4464 break; 4465 } 4466 4467 error = pmc_start(pm); 4468 } 4469 break; 4470 4471 4472 /* 4473 * Stop a PMC. 4474 */ 4475 4476 case PMC_OP_PMCSTOP: 4477 { 4478 pmc_id_t pmcid; 4479 struct pmc *pm; 4480 struct pmc_op_simple sp; 4481 4482 PMC_DOWNGRADE_SX(); 4483 4484 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 4485 break; 4486 4487 pmcid = sp.pm_pmcid; 4488 4489 /* 4490 * Mark the PMC as inactive and invoke the MD stop 4491 * routines if needed. 4492 */ 4493 4494 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 4495 break; 4496 4497 KASSERT(pmcid == pm->pm_id, 4498 ("[pmc,%d] pmc id %x != pmcid %x", __LINE__, 4499 pm->pm_id, pmcid)); 4500 4501 if (pm->pm_state == PMC_STATE_STOPPED) /* already stopped */ 4502 break; 4503 else if (pm->pm_state != PMC_STATE_RUNNING) { 4504 error = EINVAL; 4505 break; 4506 } 4507 4508 error = pmc_stop(pm); 4509 } 4510 break; 4511 4512 4513 /* 4514 * Write a user supplied value to the log file. 4515 */ 4516 4517 case PMC_OP_WRITELOG: 4518 { 4519 struct pmc_op_writelog wl; 4520 struct pmc_owner *po; 4521 4522 PMC_DOWNGRADE_SX(); 4523 4524 if ((error = copyin(arg, &wl, sizeof(wl))) != 0) 4525 break; 4526 4527 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 4528 error = EINVAL; 4529 break; 4530 } 4531 4532 if ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) { 4533 error = EINVAL; 4534 break; 4535 } 4536 4537 error = pmclog_process_userlog(po, &wl); 4538 } 4539 break; 4540 4541 4542 default: 4543 error = EINVAL; 4544 break; 4545 } 4546 4547 if (is_sx_downgraded) 4548 sx_sunlock(&pmc_sx); 4549 else 4550 sx_xunlock(&pmc_sx); 4551 done_syscall: 4552 if (error) 4553 counter_u64_add(pmc_stats.pm_syscall_errors, 1); 4554 4555 return (error); 4556 } 4557 4558 /* 4559 * Helper functions 4560 */ 4561 4562 /* 4563 * Mark the thread as needing callchain capture and post an AST. The 4564 * actual callchain capture will be done in a context where it is safe 4565 * to take page faults. 4566 */ 4567 static void 4568 pmc_post_callchain_callback(void) 4569 { 4570 struct thread *td; 4571 4572 td = curthread; 4573 4574 /* 4575 * If there is multiple PMCs for the same interrupt ignore new post 4576 */ 4577 if ((td->td_pflags & TDP_CALLCHAIN) != 0) 4578 return; 4579 4580 /* 4581 * Mark this thread as needing callchain capture. 4582 * `td->td_pflags' will be safe to touch because this thread 4583 * was in user space when it was interrupted. 4584 */ 4585 td->td_pflags |= TDP_CALLCHAIN; 4586 4587 /* 4588 * Don't let this thread migrate between CPUs until callchain 4589 * capture completes. 4590 */ 4591 sched_pin(); 4592 4593 return; 4594 } 4595 4596 static bool 4597 pmc_is_multipart(struct pmc_sample *ps) 4598 { 4599 return ((ps->ps_flags & PMC_CC_F_MULTIPART) != 0); 4600 } 4601 4602 static void 4603 pmc_multipart_add(struct pmc_sample *ps, int type, int length) 4604 { 4605 int i; 4606 uint8_t *hdr; 4607 4608 MPASS(ps->ps_pc != NULL); 4609 MPASS(ps->ps_nsamples_actual != 0); 4610 4611 hdr = (uint8_t *)ps->ps_pc; 4612 4613 for (i = 0; i < PMC_MULTIPART_HEADER_ENTRIES; i++) { 4614 if (hdr[2 * i] == PMC_CC_MULTIPART_NONE) { 4615 hdr[2 * i] = type; 4616 hdr[2 * i + 1] = length; 4617 ps->ps_nsamples_actual += length; 4618 return; 4619 } 4620 } 4621 4622 KASSERT(false, ("Too many parts in the multipart header!")); 4623 } 4624 4625 static void 4626 pmc_multipart_copydata(struct pmc_sample *ps, struct pmc_multipart *mp) 4627 { 4628 int i, scale; 4629 uint64_t *ps_pc; 4630 4631 MPASS(ps->ps_pc != NULL); 4632 MPASS(ps->ps_nsamples_actual != 0); 4633 4634 ps_pc = (uint64_t *)ps->ps_pc; 4635 4636 for (i = 0; i < mp->pl_length; i++) 4637 ps_pc[i + 1] = mp->pl_mpdata[i]; 4638 4639 scale = sizeof(uint64_t) / sizeof(uintptr_t); 4640 pmc_multipart_add(ps, mp->pl_type, scale * mp->pl_length); 4641 } 4642 4643 /* 4644 * Find a free slot in the per-cpu array of samples and capture the 4645 * current callchain there. If a sample was successfully added, a bit 4646 * is set in mask 'pmc_cpumask' denoting that the DO_SAMPLES hook 4647 * needs to be invoked from the clock handler. 4648 * 4649 * This function is meant to be called from an NMI handler. It cannot 4650 * use any of the locking primitives supplied by the OS. 4651 */ 4652 static int 4653 pmc_add_sample(ring_type_t ring, struct pmc *pm, struct trapframe *tf, 4654 struct pmc_multipart *mp) 4655 { 4656 struct pmc_sample *ps; 4657 struct pmc_samplebuffer *psb; 4658 struct thread *td; 4659 int error, cpu, callchaindepth; 4660 bool inuserspace; 4661 4662 error = 0; 4663 4664 /* 4665 * Allocate space for a sample buffer. 4666 */ 4667 cpu = curcpu; 4668 psb = pmc_pcpu[cpu]->pc_sb[ring]; 4669 inuserspace = TRAPF_USERMODE(tf); 4670 ps = PMC_PROD_SAMPLE(psb); 4671 if (psb->ps_considx != psb->ps_prodidx && 4672 ps->ps_nsamples) { /* in use, reader hasn't caught up */ 4673 pm->pm_pcpu_state[cpu].pps_stalled = 1; 4674 counter_u64_add(pmc_stats.pm_intr_bufferfull, 1); 4675 PMCDBG6(SAM,INT,1,"(spc) cpu=%d pm=%p tf=%p um=%d wr=%d rd=%d", 4676 cpu, pm, tf, inuserspace, 4677 (int)(psb->ps_prodidx & pmc_sample_mask), 4678 (int)(psb->ps_considx & pmc_sample_mask)); 4679 callchaindepth = 1; 4680 error = ENOMEM; 4681 goto done; 4682 } 4683 4684 /* Fill in entry. */ 4685 PMCDBG6(SAM,INT,1,"cpu=%d pm=%p tf=%p um=%d wr=%d rd=%d", cpu, pm, tf, 4686 inuserspace, (int)(psb->ps_prodidx & pmc_sample_mask), 4687 (int)(psb->ps_considx & pmc_sample_mask)); 4688 4689 td = curthread; 4690 ps->ps_pmc = pm; 4691 ps->ps_td = td; 4692 ps->ps_pid = td->td_proc->p_pid; 4693 ps->ps_tid = td->td_tid; 4694 ps->ps_tsc = pmc_rdtsc(); 4695 ps->ps_ticks = ticks; 4696 ps->ps_cpu = cpu; 4697 ps->ps_flags = inuserspace ? PMC_CC_F_USERSPACE : 0; 4698 ps->ps_nsamples_actual = 0; 4699 4700 callchaindepth = (pm->pm_flags & PMC_F_CALLCHAIN) ? 4701 pmc_callchaindepth : 1; 4702 4703 MPASS(ps->ps_pc != NULL); 4704 4705 if (mp != NULL) { 4706 /* Set multipart flag, clear header and copy data */ 4707 ps->ps_flags |= PMC_CC_F_MULTIPART; 4708 ps->ps_pc[0] = 0; 4709 ps->ps_nsamples_actual = 1; 4710 pmc_multipart_copydata(ps, mp); 4711 } 4712 4713 if (callchaindepth == 1) { 4714 ps->ps_pc[ps->ps_nsamples_actual] = PMC_TRAPFRAME_TO_PC(tf); 4715 } else { 4716 /* 4717 * Kernel stack traversals can be done immediately, while we 4718 * defer to an AST for user space traversals. 4719 */ 4720 if (!inuserspace) { 4721 callchaindepth = pmc_save_kernel_callchain( 4722 ps->ps_pc + ps->ps_nsamples_actual, 4723 callchaindepth - ps->ps_nsamples_actual, tf); 4724 callchaindepth += ps->ps_nsamples_actual; 4725 } else { 4726 pmc_post_callchain_callback(); 4727 callchaindepth = PMC_USER_CALLCHAIN_PENDING; 4728 } 4729 } 4730 4731 ps->ps_nsamples = callchaindepth; /* mark entry as in-use */ 4732 if (ring == PMC_UR) { 4733 ps->ps_nsamples_actual = ps->ps_nsamples; 4734 ps->ps_nsamples = PMC_USER_CALLCHAIN_PENDING; 4735 } 4736 4737 KASSERT(counter_u64_fetch(pm->pm_runcount) >= 0, 4738 ("[pmc,%d] pm=%p runcount %ju", __LINE__, pm, 4739 (uintmax_t)counter_u64_fetch(pm->pm_runcount))); 4740 4741 counter_u64_add(pm->pm_runcount, 1); /* hold onto PMC */ 4742 /* increment write pointer */ 4743 psb->ps_prodidx++; 4744 done: 4745 /* mark CPU as needing processing */ 4746 if (callchaindepth != PMC_USER_CALLCHAIN_PENDING) 4747 DPCPU_SET(pmc_sampled, 1); 4748 4749 return (error); 4750 } 4751 4752 /* 4753 * Interrupt processing. 4754 * 4755 * This function may be called from an NMI handler. It cannot use any of the 4756 * locking primitives supplied by the OS. 4757 */ 4758 int 4759 pmc_process_interrupt_mp(int ring, struct pmc *pm, struct trapframe *tf, 4760 struct pmc_multipart *mp) 4761 { 4762 struct thread *td; 4763 4764 td = curthread; 4765 if ((pm->pm_flags & PMC_F_USERCALLCHAIN) && 4766 (td->td_proc->p_flag & P_KPROC) == 0 && !TRAPF_USERMODE(tf)) { 4767 atomic_add_int(&td->td_pmcpend, 1); 4768 return (pmc_add_sample(PMC_UR, pm, tf, mp)); 4769 } 4770 return (pmc_add_sample(ring, pm, tf, mp)); 4771 } 4772 4773 int 4774 pmc_process_interrupt(int ring, struct pmc *pm, struct trapframe *tf) 4775 { 4776 return (pmc_process_interrupt_mp(ring, pm, tf, NULL)); 4777 } 4778 4779 /* 4780 * Capture a user call chain. This function will be called from ast() 4781 * before control returns to userland and before the process gets 4782 * rescheduled. 4783 */ 4784 static void 4785 pmc_capture_user_callchain(int cpu, int ring, struct trapframe *tf) 4786 { 4787 struct pmc *pm; 4788 struct pmc_sample *ps; 4789 struct pmc_samplebuffer *psb; 4790 struct thread *td; 4791 uint64_t considx, prodidx; 4792 int nsamples, nrecords, pass, iter; 4793 int start_ticks __diagused; 4794 4795 psb = pmc_pcpu[cpu]->pc_sb[ring]; 4796 td = curthread; 4797 nrecords = INT_MAX; 4798 pass = 0; 4799 start_ticks = ticks; 4800 4801 KASSERT(td->td_pflags & TDP_CALLCHAIN, 4802 ("[pmc,%d] Retrieving callchain for thread that doesn't want it", 4803 __LINE__)); 4804 restart: 4805 if (ring == PMC_UR) 4806 nrecords = atomic_readandclear_32(&td->td_pmcpend); 4807 4808 for (iter = 0, considx = psb->ps_considx, prodidx = psb->ps_prodidx; 4809 considx < prodidx && iter < pmc_nsamples; considx++, iter++) { 4810 ps = PMC_CONS_SAMPLE_OFF(psb, considx); 4811 4812 /* 4813 * Iterate through all deferred callchain requests. Walk from 4814 * the current read pointer to the current write pointer. 4815 */ 4816 #ifdef INVARIANTS 4817 if (ps->ps_nsamples == PMC_SAMPLE_FREE) { 4818 continue; 4819 } 4820 #endif 4821 if (ps->ps_td != td || 4822 ps->ps_nsamples != PMC_USER_CALLCHAIN_PENDING || 4823 ps->ps_pmc->pm_state != PMC_STATE_RUNNING) 4824 continue; 4825 4826 KASSERT(ps->ps_cpu == cpu, 4827 ("[pmc,%d] cpu mismatch ps_cpu=%d pcpu=%d", __LINE__, 4828 ps->ps_cpu, PCPU_GET(cpuid))); 4829 4830 pm = ps->ps_pmc; 4831 KASSERT(pm->pm_flags & PMC_F_CALLCHAIN, 4832 ("[pmc,%d] Retrieving callchain for PMC that doesn't " 4833 "want it", __LINE__)); 4834 KASSERT(counter_u64_fetch(pm->pm_runcount) > 0, 4835 ("[pmc,%d] runcount %ju", __LINE__, 4836 (uintmax_t)counter_u64_fetch(pm->pm_runcount))); 4837 4838 if (ring == PMC_UR) { 4839 counter_u64_add(pmc_stats.pm_merges, 1); 4840 } 4841 nsamples = ps->ps_nsamples_actual; 4842 4843 /* 4844 * Retrieve the callchain and mark the sample buffer 4845 * as 'processable' by the timer tick sweep code. 4846 */ 4847 if (__predict_true(nsamples < pmc_callchaindepth - 1)) 4848 nsamples += pmc_save_user_callchain(ps->ps_pc + nsamples, 4849 pmc_callchaindepth - nsamples - 1, tf); 4850 4851 /* 4852 * We have to prevent hardclock from potentially overwriting 4853 * this sample between when we read the value and when we set 4854 * it. 4855 */ 4856 spinlock_enter(); 4857 4858 /* 4859 * Verify that the sample hasn't been dropped in the meantime. 4860 */ 4861 if (ps->ps_nsamples == PMC_USER_CALLCHAIN_PENDING) { 4862 ps->ps_nsamples = nsamples; 4863 /* 4864 * If we couldn't get a sample, simply drop the 4865 * reference. 4866 */ 4867 if (nsamples == 0) 4868 counter_u64_add(pm->pm_runcount, -1); 4869 } 4870 spinlock_exit(); 4871 if (nrecords-- == 1) 4872 break; 4873 } 4874 if (__predict_false(ring == PMC_UR && td->td_pmcpend)) { 4875 if (pass == 0) { 4876 pass = 1; 4877 goto restart; 4878 } 4879 /* only collect samples for this part once */ 4880 td->td_pmcpend = 0; 4881 } 4882 4883 #ifdef INVARIANTS 4884 if ((ticks - start_ticks) > hz) 4885 log(LOG_ERR, "%s took %d ticks\n", __func__, (ticks - start_ticks)); 4886 #endif 4887 /* mark CPU as needing processing */ 4888 DPCPU_SET(pmc_sampled, 1); 4889 } 4890 4891 /* 4892 * Process saved PC samples. 4893 */ 4894 static void 4895 pmc_process_samples(int cpu, ring_type_t ring) 4896 { 4897 struct pmc *pm; 4898 struct thread *td; 4899 struct pmc_owner *po; 4900 struct pmc_sample *ps; 4901 struct pmc_classdep *pcd; 4902 struct pmc_samplebuffer *psb; 4903 uint64_t delta __diagused; 4904 int adjri, n; 4905 4906 KASSERT(PCPU_GET(cpuid) == cpu, 4907 ("[pmc,%d] not on the correct CPU pcpu=%d cpu=%d", __LINE__, 4908 PCPU_GET(cpuid), cpu)); 4909 4910 psb = pmc_pcpu[cpu]->pc_sb[ring]; 4911 delta = psb->ps_prodidx - psb->ps_considx; 4912 MPASS(delta <= pmc_nsamples); 4913 MPASS(psb->ps_considx <= psb->ps_prodidx); 4914 for (n = 0; psb->ps_considx < psb->ps_prodidx; psb->ps_considx++, n++) { 4915 ps = PMC_CONS_SAMPLE(psb); 4916 4917 if (__predict_false(ps->ps_nsamples == PMC_SAMPLE_FREE)) 4918 continue; 4919 4920 /* skip non-running samples */ 4921 pm = ps->ps_pmc; 4922 if (pm->pm_state != PMC_STATE_RUNNING) 4923 goto entrydone; 4924 4925 KASSERT(counter_u64_fetch(pm->pm_runcount) > 0, 4926 ("[pmc,%d] pm=%p runcount %ju", __LINE__, pm, 4927 (uintmax_t)counter_u64_fetch(pm->pm_runcount))); 4928 KASSERT(PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)), 4929 ("[pmc,%d] pmc=%p non-sampling mode=%d", __LINE__, 4930 pm, PMC_TO_MODE(pm))); 4931 4932 po = pm->pm_owner; 4933 4934 /* If there is a pending AST wait for completion */ 4935 if (ps->ps_nsamples == PMC_USER_CALLCHAIN_PENDING) { 4936 /* 4937 * If we've been waiting more than 1 tick to 4938 * collect a callchain for this record then 4939 * drop it and move on. 4940 */ 4941 if (ticks - ps->ps_ticks > 1) { 4942 /* 4943 * Track how often we hit this as it will 4944 * preferentially lose user samples 4945 * for long running system calls. 4946 */ 4947 counter_u64_add(pmc_stats.pm_overwrites, 1); 4948 goto entrydone; 4949 } 4950 /* Need a rescan at a later time. */ 4951 DPCPU_SET(pmc_sampled, 1); 4952 break; 4953 } 4954 4955 PMCDBG6(SAM,OPS,1,"cpu=%d pm=%p n=%d fl=%x wr=%d rd=%d", cpu, 4956 pm, ps->ps_nsamples, ps->ps_flags, 4957 (int)(psb->ps_prodidx & pmc_sample_mask), 4958 (int)(psb->ps_considx & pmc_sample_mask)); 4959 4960 /* 4961 * If this is a process-mode PMC that is attached to 4962 * its owner, and if the PC is in user mode, update 4963 * profiling statistics like timer-based profiling 4964 * would have done. 4965 * 4966 * Otherwise, this is either a sampling-mode PMC that 4967 * is attached to a different process than its owner, 4968 * or a system-wide sampling PMC. Dispatch a log 4969 * entry to the PMC's owner process. 4970 */ 4971 if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) { 4972 if (ps->ps_flags & PMC_CC_F_USERSPACE) { 4973 td = FIRST_THREAD_IN_PROC(po->po_owner); 4974 addupc_intr(td, ps->ps_pc[0], 1); 4975 } 4976 } else 4977 pmclog_process_callchain(pm, ps); 4978 4979 entrydone: 4980 ps->ps_nsamples = 0; /* mark entry as free */ 4981 KASSERT(counter_u64_fetch(pm->pm_runcount) > 0, 4982 ("[pmc,%d] pm=%p runcount %ju", __LINE__, pm, 4983 (uintmax_t)counter_u64_fetch(pm->pm_runcount))); 4984 4985 counter_u64_add(pm->pm_runcount, -1); 4986 } 4987 4988 counter_u64_add(pmc_stats.pm_log_sweeps, 1); 4989 4990 /* Do not re-enable stalled PMCs if we failed to process any samples */ 4991 if (n == 0) 4992 return; 4993 4994 /* 4995 * Restart any stalled sampling PMCs on this CPU. 4996 * 4997 * If the NMI handler sets the pm_stalled field of a PMC after 4998 * the check below, we'll end up processing the stalled PMC at 4999 * the next hardclock tick. 5000 */ 5001 for (n = 0; n < md->pmd_npmc; n++) { 5002 pcd = pmc_ri_to_classdep(md, n, &adjri); 5003 KASSERT(pcd != NULL, 5004 ("[pmc,%d] null pcd ri=%d", __LINE__, n)); 5005 (void)(*pcd->pcd_get_config)(cpu, adjri, &pm); 5006 5007 if (pm == NULL || /* !cfg'ed */ 5008 pm->pm_state != PMC_STATE_RUNNING || /* !active */ 5009 !PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)) || /* !sampling */ 5010 !pm->pm_pcpu_state[cpu].pps_cpustate || /* !desired */ 5011 !pm->pm_pcpu_state[cpu].pps_stalled) /* !stalled */ 5012 continue; 5013 5014 pm->pm_pcpu_state[cpu].pps_stalled = 0; 5015 (void)(*pcd->pcd_start_pmc)(cpu, adjri, pm); 5016 } 5017 } 5018 5019 /* 5020 * Event handlers. 5021 */ 5022 5023 /* 5024 * Handle a process exit. 5025 * 5026 * Remove this process from all hash tables. If this process 5027 * owned any PMCs, turn off those PMCs and deallocate them, 5028 * removing any associations with target processes. 5029 * 5030 * This function will be called by the last 'thread' of a 5031 * process. 5032 * 5033 * XXX This eventhandler gets called early in the exit process. 5034 * Consider using a 'hook' invocation from thread_exit() or equivalent 5035 * spot. Another negative is that kse_exit doesn't seem to call 5036 * exit1() [??]. 5037 */ 5038 static void 5039 pmc_process_exit(void *arg __unused, struct proc *p) 5040 { 5041 struct pmc *pm; 5042 struct pmc_owner *po; 5043 struct pmc_process *pp; 5044 struct pmc_classdep *pcd; 5045 pmc_value_t newvalue, tmp; 5046 int ri, adjri, cpu; 5047 bool is_using_hwpmcs; 5048 5049 PROC_LOCK(p); 5050 is_using_hwpmcs = (p->p_flag & P_HWPMC) != 0; 5051 PROC_UNLOCK(p); 5052 5053 /* 5054 * Log a sysexit event to all SS PMC owners. 5055 */ 5056 PMC_EPOCH_ENTER(); 5057 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) { 5058 if ((po->po_flags & PMC_PO_OWNS_LOGFILE) != 0) 5059 pmclog_process_sysexit(po, p->p_pid); 5060 } 5061 PMC_EPOCH_EXIT(); 5062 5063 PMC_GET_SX_XLOCK(); 5064 PMCDBG3(PRC,EXT,1,"process-exit proc=%p (%d, %s)", p, p->p_pid, 5065 p->p_comm); 5066 5067 if (!is_using_hwpmcs) 5068 goto out; 5069 5070 /* 5071 * Since this code is invoked by the last thread in an exiting process, 5072 * we would have context switched IN at some prior point. However, with 5073 * PREEMPTION, kernel mode context switches may happen any time, so we 5074 * want to disable a context switch OUT till we get any PMCs targeting 5075 * this process off the hardware. 5076 * 5077 * We also need to atomically remove this process' entry from our 5078 * target process hash table, using PMC_FLAG_REMOVE. 5079 */ 5080 PMCDBG3(PRC,EXT,1, "process-exit proc=%p (%d, %s)", p, p->p_pid, 5081 p->p_comm); 5082 5083 critical_enter(); /* no preemption */ 5084 5085 cpu = curthread->td_oncpu; 5086 5087 pp = pmc_find_process_descriptor(p, PMC_FLAG_REMOVE); 5088 if (pp == NULL) { 5089 critical_exit(); 5090 goto out; 5091 } 5092 5093 PMCDBG2(PRC,EXT,2, "process-exit proc=%p pmc-process=%p", p, pp); 5094 5095 /* 5096 * The exiting process could be the target of some PMCs which will be 5097 * running on currently executing CPU. 5098 * 5099 * We need to turn these PMCs off like we would do at context switch 5100 * OUT time. 5101 */ 5102 for (ri = 0; ri < md->pmd_npmc; ri++) { 5103 /* 5104 * Pick up the pmc pointer from hardware state similar to the 5105 * CSW_OUT code. 5106 */ 5107 pm = NULL; 5108 pcd = pmc_ri_to_classdep(md, ri, &adjri); 5109 5110 (void)(*pcd->pcd_get_config)(cpu, adjri, &pm); 5111 5112 PMCDBG2(PRC,EXT,2, "ri=%d pm=%p", ri, pm); 5113 5114 if (pm == NULL || !PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) 5115 continue; 5116 5117 PMCDBG4(PRC,EXT,2, "ppmcs[%d]=%p pm=%p state=%d", ri, 5118 pp->pp_pmcs[ri].pp_pmc, pm, pm->pm_state); 5119 5120 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 5121 ("[pmc,%d] ri mismatch pmc(%d) ri(%d)", __LINE__, 5122 PMC_TO_ROWINDEX(pm), ri)); 5123 KASSERT(pm == pp->pp_pmcs[ri].pp_pmc, 5124 ("[pmc,%d] pm %p != pp_pmcs[%d] %p", __LINE__, pm, ri, 5125 pp->pp_pmcs[ri].pp_pmc)); 5126 KASSERT(counter_u64_fetch(pm->pm_runcount) > 0, 5127 ("[pmc,%d] bad runcount ri %d rc %ju", __LINE__, ri, 5128 (uintmax_t)counter_u64_fetch(pm->pm_runcount))); 5129 5130 /* 5131 * Change desired state, and then stop if not stalled. This 5132 * two-step dance should avoid race conditions where an 5133 * interrupt re-enables the PMC after this code has already 5134 * checked the pm_stalled flag. 5135 */ 5136 if (pm->pm_pcpu_state[cpu].pps_cpustate) { 5137 pm->pm_pcpu_state[cpu].pps_cpustate = 0; 5138 if (!pm->pm_pcpu_state[cpu].pps_stalled) { 5139 (void)pcd->pcd_stop_pmc(cpu, adjri, pm); 5140 5141 if (PMC_TO_MODE(pm) == PMC_MODE_TC) { 5142 pcd->pcd_read_pmc(cpu, adjri, pm, 5143 &newvalue); 5144 tmp = newvalue - PMC_PCPU_SAVED(cpu, ri); 5145 5146 mtx_pool_lock_spin(pmc_mtxpool, pm); 5147 pm->pm_gv.pm_savedvalue += tmp; 5148 pp->pp_pmcs[ri].pp_pmcval += tmp; 5149 mtx_pool_unlock_spin(pmc_mtxpool, pm); 5150 } 5151 } 5152 } 5153 5154 KASSERT(counter_u64_fetch(pm->pm_runcount) > 0, 5155 ("[pmc,%d] runcount is %d", __LINE__, ri)); 5156 5157 counter_u64_add(pm->pm_runcount, -1); 5158 (void)pcd->pcd_config_pmc(cpu, adjri, NULL); 5159 } 5160 5161 /* 5162 * Inform the MD layer of this pseudo "context switch out". 5163 */ 5164 (void)md->pmd_switch_out(pmc_pcpu[cpu], pp); 5165 5166 critical_exit(); /* ok to be pre-empted now */ 5167 5168 /* 5169 * Unlink this process from the PMCs that are targeting it. This will 5170 * send a signal to all PMC owner's whose PMCs are orphaned. 5171 * 5172 * Log PMC value at exit time if requested. 5173 */ 5174 for (ri = 0; ri < md->pmd_npmc; ri++) { 5175 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) { 5176 if ((pm->pm_flags & PMC_F_NEEDS_LOGFILE) != 0 && 5177 PMC_IS_COUNTING_MODE(PMC_TO_MODE(pm))) { 5178 pmclog_process_procexit(pm, pp); 5179 } 5180 pmc_unlink_target_process(pm, pp); 5181 } 5182 } 5183 free(pp, M_PMC); 5184 5185 out: 5186 /* 5187 * If the process owned PMCs, free them up and free up memory. 5188 */ 5189 if ((po = pmc_find_owner_descriptor(p)) != NULL) { 5190 if ((po->po_flags & PMC_PO_OWNS_LOGFILE) != 0) 5191 pmclog_close(po); 5192 pmc_remove_owner(po); 5193 pmc_destroy_owner_descriptor(po); 5194 } 5195 5196 sx_xunlock(&pmc_sx); 5197 } 5198 5199 /* 5200 * Handle a process fork. 5201 * 5202 * If the parent process 'p1' is under HWPMC monitoring, then copy 5203 * over any attached PMCs that have 'do_descendants' semantics. 5204 */ 5205 static void 5206 pmc_process_fork(void *arg __unused, struct proc *p1, struct proc *newproc, 5207 int flags __unused) 5208 { 5209 struct pmc *pm; 5210 struct pmc_owner *po; 5211 struct pmc_process *ppnew, *ppold; 5212 unsigned int ri; 5213 bool is_using_hwpmcs, do_descendants; 5214 5215 PROC_LOCK(p1); 5216 is_using_hwpmcs = (p1->p_flag & P_HWPMC) != 0; 5217 PROC_UNLOCK(p1); 5218 5219 /* 5220 * If there are system-wide sampling PMCs active, we need to 5221 * log all fork events to their owner's logs. 5222 */ 5223 PMC_EPOCH_ENTER(); 5224 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) { 5225 if (po->po_flags & PMC_PO_OWNS_LOGFILE) { 5226 pmclog_process_procfork(po, p1->p_pid, newproc->p_pid); 5227 pmclog_process_proccreate(po, newproc, 1); 5228 } 5229 } 5230 PMC_EPOCH_EXIT(); 5231 5232 if (!is_using_hwpmcs) 5233 return; 5234 5235 PMC_GET_SX_XLOCK(); 5236 PMCDBG4(PMC,FRK,1, "process-fork proc=%p (%d, %s) -> %p", p1, 5237 p1->p_pid, p1->p_comm, newproc); 5238 5239 /* 5240 * If the parent process (curthread->td_proc) is a 5241 * target of any PMCs, look for PMCs that are to be 5242 * inherited, and link these into the new process 5243 * descriptor. 5244 */ 5245 ppold = pmc_find_process_descriptor(curthread->td_proc, PMC_FLAG_NONE); 5246 if (ppold == NULL) 5247 goto done; /* nothing to do */ 5248 5249 do_descendants = false; 5250 for (ri = 0; ri < md->pmd_npmc; ri++) { 5251 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL && 5252 (pm->pm_flags & PMC_F_DESCENDANTS) != 0) { 5253 do_descendants = true; 5254 break; 5255 } 5256 } 5257 if (!do_descendants) /* nothing to do */ 5258 goto done; 5259 5260 /* 5261 * Now mark the new process as being tracked by this driver. 5262 */ 5263 PROC_LOCK(newproc); 5264 newproc->p_flag |= P_HWPMC; 5265 PROC_UNLOCK(newproc); 5266 5267 /* Allocate a descriptor for the new process. */ 5268 ppnew = pmc_find_process_descriptor(newproc, PMC_FLAG_ALLOCATE); 5269 if (ppnew == NULL) 5270 goto done; 5271 5272 /* 5273 * Run through all PMCs that were targeting the old process 5274 * and which specified F_DESCENDANTS and attach them to the 5275 * new process. 5276 * 5277 * Log the fork event to all owners of PMCs attached to this 5278 * process, if not already logged. 5279 */ 5280 for (ri = 0; ri < md->pmd_npmc; ri++) { 5281 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL && 5282 (pm->pm_flags & PMC_F_DESCENDANTS) != 0) { 5283 pmc_link_target_process(pm, ppnew); 5284 po = pm->pm_owner; 5285 if (po->po_sscount == 0 && 5286 (po->po_flags & PMC_PO_OWNS_LOGFILE) != 0) { 5287 pmclog_process_procfork(po, p1->p_pid, 5288 newproc->p_pid); 5289 } 5290 } 5291 } 5292 5293 done: 5294 sx_xunlock(&pmc_sx); 5295 } 5296 5297 static void 5298 pmc_process_threadcreate(struct thread *td) 5299 { 5300 struct pmc_owner *po; 5301 5302 PMC_EPOCH_ENTER(); 5303 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) { 5304 if ((po->po_flags & PMC_PO_OWNS_LOGFILE) != 0) 5305 pmclog_process_threadcreate(po, td, 1); 5306 } 5307 PMC_EPOCH_EXIT(); 5308 } 5309 5310 static void 5311 pmc_process_threadexit(struct thread *td) 5312 { 5313 struct pmc_owner *po; 5314 5315 PMC_EPOCH_ENTER(); 5316 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) { 5317 if ((po->po_flags & PMC_PO_OWNS_LOGFILE) != 0) 5318 pmclog_process_threadexit(po, td); 5319 } 5320 PMC_EPOCH_EXIT(); 5321 } 5322 5323 static void 5324 pmc_process_proccreate(struct proc *p) 5325 { 5326 struct pmc_owner *po; 5327 5328 PMC_EPOCH_ENTER(); 5329 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) { 5330 if ((po->po_flags & PMC_PO_OWNS_LOGFILE) != 0) 5331 pmclog_process_proccreate(po, p, 1 /* sync */); 5332 } 5333 PMC_EPOCH_EXIT(); 5334 } 5335 5336 static void 5337 pmc_process_allproc(struct pmc *pm) 5338 { 5339 struct pmc_owner *po; 5340 struct thread *td; 5341 struct proc *p; 5342 5343 po = pm->pm_owner; 5344 if ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) 5345 return; 5346 5347 sx_slock(&allproc_lock); 5348 FOREACH_PROC_IN_SYSTEM(p) { 5349 pmclog_process_proccreate(po, p, 0 /* sync */); 5350 PROC_LOCK(p); 5351 FOREACH_THREAD_IN_PROC(p, td) 5352 pmclog_process_threadcreate(po, td, 0 /* sync */); 5353 PROC_UNLOCK(p); 5354 } 5355 sx_sunlock(&allproc_lock); 5356 pmclog_flush(po, 0); 5357 } 5358 5359 static void 5360 pmc_kld_load(void *arg __unused, linker_file_t lf) 5361 { 5362 struct pmc_owner *po; 5363 5364 /* 5365 * Notify owners of system sampling PMCs about KLD operations. 5366 */ 5367 PMC_EPOCH_ENTER(); 5368 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) { 5369 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 5370 pmclog_process_map_in(po, (pid_t) -1, 5371 (uintfptr_t) lf->address, lf->pathname); 5372 } 5373 PMC_EPOCH_EXIT(); 5374 5375 /* 5376 * TODO: Notify owners of (all) process-sampling PMCs too. 5377 */ 5378 } 5379 5380 static void 5381 pmc_kld_unload(void *arg __unused, const char *filename __unused, 5382 caddr_t address, size_t size) 5383 { 5384 struct pmc_owner *po; 5385 5386 PMC_EPOCH_ENTER(); 5387 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) { 5388 if ((po->po_flags & PMC_PO_OWNS_LOGFILE) != 0) { 5389 pmclog_process_map_out(po, (pid_t)-1, 5390 (uintfptr_t)address, (uintfptr_t)address + size); 5391 } 5392 } 5393 PMC_EPOCH_EXIT(); 5394 5395 /* 5396 * TODO: Notify owners of process-sampling PMCs. 5397 */ 5398 } 5399 5400 /* 5401 * initialization 5402 */ 5403 static const char * 5404 pmc_name_of_pmcclass(enum pmc_class class) 5405 { 5406 5407 switch (class) { 5408 #undef __PMC_CLASS 5409 #define __PMC_CLASS(S,V,D) \ 5410 case PMC_CLASS_##S: \ 5411 return #S; 5412 __PMC_CLASSES(); 5413 default: 5414 return ("<unknown>"); 5415 } 5416 } 5417 5418 /* 5419 * Base class initializer: allocate structure and set default classes. 5420 */ 5421 struct pmc_mdep * 5422 pmc_mdep_alloc(int nclasses) 5423 { 5424 struct pmc_mdep *md; 5425 int n; 5426 5427 /* SOFT + md classes */ 5428 n = 1 + nclasses; 5429 md = malloc(sizeof(struct pmc_mdep) + n * sizeof(struct pmc_classdep), 5430 M_PMC, M_WAITOK | M_ZERO); 5431 md->pmd_nclass = n; 5432 5433 /* Default methods */ 5434 md->pmd_switch_in = generic_switch_in; 5435 md->pmd_switch_out = generic_switch_out; 5436 5437 /* Add base class. */ 5438 pmc_soft_initialize(md); 5439 return (md); 5440 } 5441 5442 void 5443 pmc_mdep_free(struct pmc_mdep *md) 5444 { 5445 pmc_soft_finalize(md); 5446 free(md, M_PMC); 5447 } 5448 5449 static int 5450 generic_switch_in(struct pmc_cpu *pc __unused, struct pmc_process *pp __unused) 5451 { 5452 5453 return (0); 5454 } 5455 5456 static int 5457 generic_switch_out(struct pmc_cpu *pc __unused, struct pmc_process *pp __unused) 5458 { 5459 5460 return (0); 5461 } 5462 5463 static struct pmc_mdep * 5464 pmc_generic_cpu_initialize(void) 5465 { 5466 struct pmc_mdep *md; 5467 5468 md = pmc_mdep_alloc(0); 5469 5470 md->pmd_cputype = PMC_CPU_GENERIC; 5471 5472 return (md); 5473 } 5474 5475 static void 5476 pmc_generic_cpu_finalize(struct pmc_mdep *md __unused) 5477 { 5478 5479 } 5480 5481 static int 5482 pmc_initialize(void) 5483 { 5484 struct pcpu *pc; 5485 struct pmc_binding pb; 5486 struct pmc_classdep *pcd; 5487 struct pmc_sample *ps; 5488 struct pmc_samplebuffer *sb; 5489 int c, cpu, error, n, ri; 5490 u_int maxcpu, domain; 5491 5492 md = NULL; 5493 error = 0; 5494 5495 pmc_stats.pm_intr_ignored = counter_u64_alloc(M_WAITOK); 5496 pmc_stats.pm_intr_processed = counter_u64_alloc(M_WAITOK); 5497 pmc_stats.pm_intr_bufferfull = counter_u64_alloc(M_WAITOK); 5498 pmc_stats.pm_syscalls = counter_u64_alloc(M_WAITOK); 5499 pmc_stats.pm_syscall_errors = counter_u64_alloc(M_WAITOK); 5500 pmc_stats.pm_buffer_requests = counter_u64_alloc(M_WAITOK); 5501 pmc_stats.pm_buffer_requests_failed = counter_u64_alloc(M_WAITOK); 5502 pmc_stats.pm_log_sweeps = counter_u64_alloc(M_WAITOK); 5503 pmc_stats.pm_merges = counter_u64_alloc(M_WAITOK); 5504 pmc_stats.pm_overwrites = counter_u64_alloc(M_WAITOK); 5505 5506 #ifdef HWPMC_DEBUG 5507 /* parse debug flags first */ 5508 if (TUNABLE_STR_FETCH(PMC_SYSCTL_NAME_PREFIX "debugflags", 5509 pmc_debugstr, sizeof(pmc_debugstr))) { 5510 pmc_debugflags_parse(pmc_debugstr, pmc_debugstr + 5511 strlen(pmc_debugstr)); 5512 } 5513 #endif 5514 5515 PMCDBG1(MOD,INI,0, "PMC Initialize (version %x)", PMC_VERSION); 5516 5517 /* check kernel version */ 5518 if (pmc_kernel_version != PMC_VERSION) { 5519 if (pmc_kernel_version == 0) 5520 printf("hwpmc: this kernel has not been compiled with " 5521 "'options HWPMC_HOOKS'.\n"); 5522 else 5523 printf("hwpmc: kernel version (0x%x) does not match " 5524 "module version (0x%x).\n", pmc_kernel_version, 5525 PMC_VERSION); 5526 return (EPROGMISMATCH); 5527 } 5528 5529 /* 5530 * check sysctl parameters 5531 */ 5532 if (pmc_hashsize <= 0) { 5533 printf("hwpmc: tunable \"hashsize\"=%d must be " 5534 "greater than zero.\n", pmc_hashsize); 5535 pmc_hashsize = PMC_HASH_SIZE; 5536 } 5537 5538 if (pmc_nsamples <= 0 || pmc_nsamples > 65535) { 5539 printf("hwpmc: tunable \"nsamples\"=%d out of " 5540 "range.\n", pmc_nsamples); 5541 pmc_nsamples = PMC_NSAMPLES; 5542 } 5543 pmc_sample_mask = pmc_nsamples - 1; 5544 5545 if (pmc_callchaindepth <= 0 || 5546 pmc_callchaindepth > PMC_CALLCHAIN_DEPTH_MAX) { 5547 printf("hwpmc: tunable \"callchaindepth\"=%d out of " 5548 "range - using %d.\n", pmc_callchaindepth, 5549 PMC_CALLCHAIN_DEPTH_MAX); 5550 pmc_callchaindepth = PMC_CALLCHAIN_DEPTH_MAX; 5551 } 5552 5553 md = pmc_md_initialize(); 5554 if (md == NULL) { 5555 /* Default to generic CPU. */ 5556 md = pmc_generic_cpu_initialize(); 5557 if (md == NULL) 5558 return (ENOSYS); 5559 } 5560 5561 /* 5562 * Refresh classes base ri. Optional classes may come in different 5563 * order. 5564 */ 5565 for (ri = c = 0; c < md->pmd_nclass; c++) { 5566 pcd = &md->pmd_classdep[c]; 5567 pcd->pcd_ri = ri; 5568 ri += pcd->pcd_num; 5569 } 5570 5571 KASSERT(md->pmd_nclass >= 1 && md->pmd_npmc >= 1, 5572 ("[pmc,%d] no classes or pmcs", __LINE__)); 5573 5574 /* Compute the map from row-indices to classdep pointers. */ 5575 pmc_rowindex_to_classdep = malloc(sizeof(struct pmc_classdep *) * 5576 md->pmd_npmc, M_PMC, M_WAITOK | M_ZERO); 5577 5578 for (n = 0; n < md->pmd_npmc; n++) 5579 pmc_rowindex_to_classdep[n] = NULL; 5580 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 for (n = 0; error == 0 && n < md->pmd_nclass; n++) 5612 if (md->pmd_classdep[n].pcd_num > 0) 5613 error = md->pmd_classdep[n].pcd_pcpu_init(md, 5614 cpu); 5615 } 5616 pmc_restore_cpu_binding(&pb); 5617 5618 if (error != 0) 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_domainset(sizeof(struct pmc_samplebuffer) + 5628 pmc_nsamples * sizeof(struct pmc_sample), M_PMC, 5629 DOMAINSET_PREF(domain), M_WAITOK | M_ZERO); 5630 5631 KASSERT(pmc_pcpu[cpu] != NULL, 5632 ("[pmc,%d] cpu=%d Null per-cpu data", __LINE__, cpu)); 5633 5634 sb->ps_callchains = malloc_domainset(pmc_callchaindepth * 5635 pmc_nsamples * sizeof(uintptr_t), M_PMC, 5636 DOMAINSET_PREF(domain), M_WAITOK | M_ZERO); 5637 5638 for (n = 0, ps = sb->ps_samples; n < pmc_nsamples; n++, ps++) 5639 ps->ps_pc = sb->ps_callchains + 5640 (n * pmc_callchaindepth); 5641 5642 pmc_pcpu[cpu]->pc_sb[PMC_HR] = sb; 5643 5644 sb = malloc_domainset(sizeof(struct pmc_samplebuffer) + 5645 pmc_nsamples * sizeof(struct pmc_sample), M_PMC, 5646 DOMAINSET_PREF(domain), M_WAITOK | M_ZERO); 5647 5648 sb->ps_callchains = malloc_domainset(pmc_callchaindepth * 5649 pmc_nsamples * sizeof(uintptr_t), M_PMC, 5650 DOMAINSET_PREF(domain), M_WAITOK | M_ZERO); 5651 for (n = 0, ps = sb->ps_samples; n < pmc_nsamples; n++, ps++) 5652 ps->ps_pc = sb->ps_callchains + 5653 (n * pmc_callchaindepth); 5654 5655 pmc_pcpu[cpu]->pc_sb[PMC_SR] = sb; 5656 5657 sb = malloc_domainset(sizeof(struct pmc_samplebuffer) + 5658 pmc_nsamples * sizeof(struct pmc_sample), M_PMC, 5659 DOMAINSET_PREF(domain), M_WAITOK | M_ZERO); 5660 sb->ps_callchains = malloc_domainset(pmc_callchaindepth * 5661 pmc_nsamples * sizeof(uintptr_t), M_PMC, 5662 DOMAINSET_PREF(domain), M_WAITOK | M_ZERO); 5663 for (n = 0, ps = sb->ps_samples; n < pmc_nsamples; n++, ps++) 5664 ps->ps_pc = sb->ps_callchains + n * pmc_callchaindepth; 5665 5666 pmc_pcpu[cpu]->pc_sb[PMC_UR] = sb; 5667 } 5668 5669 /* allocate space for the row disposition array */ 5670 pmc_pmcdisp = malloc(sizeof(enum pmc_mode) * md->pmd_npmc, 5671 M_PMC, M_WAITOK | M_ZERO); 5672 5673 /* mark all PMCs as available */ 5674 for (n = 0; n < md->pmd_npmc; n++) 5675 PMC_MARK_ROW_FREE(n); 5676 5677 /* allocate thread hash tables */ 5678 pmc_ownerhash = hashinit(pmc_hashsize, M_PMC, 5679 &pmc_ownerhashmask); 5680 5681 pmc_processhash = hashinit(pmc_hashsize, M_PMC, 5682 &pmc_processhashmask); 5683 mtx_init(&pmc_processhash_mtx, "pmc-process-hash", "pmc-leaf", 5684 MTX_SPIN); 5685 5686 CK_LIST_INIT(&pmc_ss_owners); 5687 pmc_ss_count = 0; 5688 5689 /* allocate a pool of spin mutexes */ 5690 pmc_mtxpool = mtx_pool_create("pmc-leaf", pmc_mtxpool_size, 5691 MTX_SPIN); 5692 5693 PMCDBG4(MOD,INI,1, "pmc_ownerhash=%p, mask=0x%lx " 5694 "targethash=%p mask=0x%lx", pmc_ownerhash, pmc_ownerhashmask, 5695 pmc_processhash, pmc_processhashmask); 5696 5697 /* Initialize a spin mutex for the thread free list. */ 5698 mtx_init(&pmc_threadfreelist_mtx, "pmc-threadfreelist", "pmc-leaf", 5699 MTX_SPIN); 5700 5701 /* Initialize the task to prune the thread free list. */ 5702 TASK_INIT(&free_task, 0, pmc_thread_descriptor_pool_free_task, NULL); 5703 5704 /* register process {exit,fork,exec} handlers */ 5705 pmc_exit_tag = EVENTHANDLER_REGISTER(process_exit, 5706 pmc_process_exit, NULL, EVENTHANDLER_PRI_ANY); 5707 pmc_fork_tag = EVENTHANDLER_REGISTER(process_fork, 5708 pmc_process_fork, NULL, EVENTHANDLER_PRI_ANY); 5709 5710 /* register kld event handlers */ 5711 pmc_kld_load_tag = EVENTHANDLER_REGISTER(kld_load, pmc_kld_load, 5712 NULL, EVENTHANDLER_PRI_ANY); 5713 pmc_kld_unload_tag = EVENTHANDLER_REGISTER(kld_unload, pmc_kld_unload, 5714 NULL, EVENTHANDLER_PRI_ANY); 5715 5716 /* initialize logging */ 5717 pmclog_initialize(); 5718 5719 /* set hook functions */ 5720 pmc_intr = md->pmd_intr; 5721 wmb(); 5722 pmc_hook = pmc_hook_handler; 5723 5724 if (error == 0) { 5725 printf(PMC_MODULE_NAME ":"); 5726 for (n = 0; n < md->pmd_nclass; n++) { 5727 if (md->pmd_classdep[n].pcd_num == 0) 5728 continue; 5729 pcd = &md->pmd_classdep[n]; 5730 printf(" %s/%d/%d/0x%b", 5731 pmc_name_of_pmcclass(pcd->pcd_class), 5732 pcd->pcd_num, 5733 pcd->pcd_width, 5734 pcd->pcd_caps, 5735 "\20" 5736 "\1INT\2USR\3SYS\4EDG\5THR" 5737 "\6REA\7WRI\10INV\11QUA\12PRC" 5738 "\13TAG\14CSC"); 5739 } 5740 printf("\n"); 5741 } 5742 5743 return (error); 5744 } 5745 5746 /* prepare to be unloaded */ 5747 static void 5748 pmc_cleanup(void) 5749 { 5750 struct pmc_binding pb; 5751 struct pmc_owner *po, *tmp; 5752 struct pmc_ownerhash *ph; 5753 struct pmc_processhash *prh __pmcdbg_used; 5754 u_int maxcpu; 5755 int cpu, c; 5756 5757 PMCDBG0(MOD,INI,0, "cleanup"); 5758 5759 /* switch off sampling */ 5760 CPU_FOREACH(cpu) 5761 DPCPU_ID_SET(cpu, pmc_sampled, 0); 5762 pmc_intr = NULL; 5763 5764 sx_xlock(&pmc_sx); 5765 if (pmc_hook == NULL) { /* being unloaded already */ 5766 sx_xunlock(&pmc_sx); 5767 return; 5768 } 5769 5770 pmc_hook = NULL; /* prevent new threads from entering module */ 5771 5772 /* deregister event handlers */ 5773 EVENTHANDLER_DEREGISTER(process_fork, pmc_fork_tag); 5774 EVENTHANDLER_DEREGISTER(process_exit, pmc_exit_tag); 5775 EVENTHANDLER_DEREGISTER(kld_load, pmc_kld_load_tag); 5776 EVENTHANDLER_DEREGISTER(kld_unload, pmc_kld_unload_tag); 5777 5778 /* send SIGBUS to all owner threads, free up allocations */ 5779 if (pmc_ownerhash != NULL) { 5780 for (ph = pmc_ownerhash; 5781 ph <= &pmc_ownerhash[pmc_ownerhashmask]; 5782 ph++) { 5783 LIST_FOREACH_SAFE(po, ph, po_next, tmp) { 5784 pmc_remove_owner(po); 5785 5786 PMCDBG3(MOD,INI,2, 5787 "cleanup signal proc=%p (%d, %s)", 5788 po->po_owner, po->po_owner->p_pid, 5789 po->po_owner->p_comm); 5790 5791 PROC_LOCK(po->po_owner); 5792 kern_psignal(po->po_owner, SIGBUS); 5793 PROC_UNLOCK(po->po_owner); 5794 5795 pmc_destroy_owner_descriptor(po); 5796 } 5797 } 5798 } 5799 5800 /* reclaim allocated data structures */ 5801 taskqueue_drain(taskqueue_fast, &free_task); 5802 mtx_destroy(&pmc_threadfreelist_mtx); 5803 pmc_thread_descriptor_pool_drain(); 5804 5805 if (pmc_mtxpool != NULL) 5806 mtx_pool_destroy(&pmc_mtxpool); 5807 5808 mtx_destroy(&pmc_processhash_mtx); 5809 if (pmc_processhash != NULL) { 5810 #ifdef HWPMC_DEBUG 5811 struct pmc_process *pp; 5812 5813 PMCDBG0(MOD,INI,3, "destroy process hash"); 5814 for (prh = pmc_processhash; 5815 prh <= &pmc_processhash[pmc_processhashmask]; 5816 prh++) 5817 LIST_FOREACH(pp, prh, pp_next) 5818 PMCDBG1(MOD,INI,3, "pid=%d", pp->pp_proc->p_pid); 5819 #endif 5820 5821 hashdestroy(pmc_processhash, M_PMC, pmc_processhashmask); 5822 pmc_processhash = NULL; 5823 } 5824 5825 if (pmc_ownerhash != NULL) { 5826 PMCDBG0(MOD,INI,3, "destroy owner hash"); 5827 hashdestroy(pmc_ownerhash, M_PMC, pmc_ownerhashmask); 5828 pmc_ownerhash = NULL; 5829 } 5830 5831 KASSERT(CK_LIST_EMPTY(&pmc_ss_owners), 5832 ("[pmc,%d] Global SS owner list not empty", __LINE__)); 5833 KASSERT(pmc_ss_count == 0, 5834 ("[pmc,%d] Global SS count not empty", __LINE__)); 5835 5836 /* do processor and pmc-class dependent cleanup */ 5837 maxcpu = pmc_cpu_max(); 5838 5839 PMCDBG0(MOD,INI,3, "md cleanup"); 5840 if (md) { 5841 pmc_save_cpu_binding(&pb); 5842 for (cpu = 0; cpu < maxcpu; cpu++) { 5843 PMCDBG2(MOD,INI,1,"pmc-cleanup cpu=%d pcs=%p", 5844 cpu, pmc_pcpu[cpu]); 5845 if (!pmc_cpu_is_active(cpu) || pmc_pcpu[cpu] == NULL) 5846 continue; 5847 5848 pmc_select_cpu(cpu); 5849 for (c = 0; c < md->pmd_nclass; c++) { 5850 if (md->pmd_classdep[c].pcd_num > 0) { 5851 md->pmd_classdep[c].pcd_pcpu_fini(md, 5852 cpu); 5853 } 5854 } 5855 } 5856 5857 if (md->pmd_cputype == PMC_CPU_GENERIC) 5858 pmc_generic_cpu_finalize(md); 5859 else 5860 pmc_md_finalize(md); 5861 5862 pmc_mdep_free(md); 5863 md = NULL; 5864 pmc_restore_cpu_binding(&pb); 5865 } 5866 5867 /* Free per-cpu descriptors. */ 5868 for (cpu = 0; cpu < maxcpu; cpu++) { 5869 if (!pmc_cpu_is_active(cpu)) 5870 continue; 5871 KASSERT(pmc_pcpu[cpu]->pc_sb[PMC_HR] != NULL, 5872 ("[pmc,%d] Null hw cpu sample buffer cpu=%d", __LINE__, 5873 cpu)); 5874 KASSERT(pmc_pcpu[cpu]->pc_sb[PMC_SR] != NULL, 5875 ("[pmc,%d] Null sw cpu sample buffer cpu=%d", __LINE__, 5876 cpu)); 5877 KASSERT(pmc_pcpu[cpu]->pc_sb[PMC_UR] != NULL, 5878 ("[pmc,%d] Null userret cpu sample buffer cpu=%d", __LINE__, 5879 cpu)); 5880 free(pmc_pcpu[cpu]->pc_sb[PMC_HR]->ps_callchains, M_PMC); 5881 free(pmc_pcpu[cpu]->pc_sb[PMC_HR], M_PMC); 5882 free(pmc_pcpu[cpu]->pc_sb[PMC_SR]->ps_callchains, M_PMC); 5883 free(pmc_pcpu[cpu]->pc_sb[PMC_SR], M_PMC); 5884 free(pmc_pcpu[cpu]->pc_sb[PMC_UR]->ps_callchains, M_PMC); 5885 free(pmc_pcpu[cpu]->pc_sb[PMC_UR], M_PMC); 5886 free(pmc_pcpu[cpu], M_PMC); 5887 } 5888 5889 free(pmc_pcpu, M_PMC); 5890 pmc_pcpu = NULL; 5891 5892 free(pmc_pcpu_saved, M_PMC); 5893 pmc_pcpu_saved = NULL; 5894 5895 if (pmc_pmcdisp != NULL) { 5896 free(pmc_pmcdisp, M_PMC); 5897 pmc_pmcdisp = NULL; 5898 } 5899 5900 if (pmc_rowindex_to_classdep != NULL) { 5901 free(pmc_rowindex_to_classdep, M_PMC); 5902 pmc_rowindex_to_classdep = NULL; 5903 } 5904 5905 pmclog_shutdown(); 5906 counter_u64_free(pmc_stats.pm_intr_ignored); 5907 counter_u64_free(pmc_stats.pm_intr_processed); 5908 counter_u64_free(pmc_stats.pm_intr_bufferfull); 5909 counter_u64_free(pmc_stats.pm_syscalls); 5910 counter_u64_free(pmc_stats.pm_syscall_errors); 5911 counter_u64_free(pmc_stats.pm_buffer_requests); 5912 counter_u64_free(pmc_stats.pm_buffer_requests_failed); 5913 counter_u64_free(pmc_stats.pm_log_sweeps); 5914 counter_u64_free(pmc_stats.pm_merges); 5915 counter_u64_free(pmc_stats.pm_overwrites); 5916 sx_xunlock(&pmc_sx); /* we are done */ 5917 } 5918 5919 /* 5920 * The function called at load/unload. 5921 */ 5922 static int 5923 load(struct module *module __unused, int cmd, void *arg __unused) 5924 { 5925 int error; 5926 5927 error = 0; 5928 5929 switch (cmd) { 5930 case MOD_LOAD: 5931 /* initialize the subsystem */ 5932 error = pmc_initialize(); 5933 if (error != 0) 5934 break; 5935 PMCDBG2(MOD,INI,1, "syscall=%d maxcpu=%d", pmc_syscall_num, 5936 pmc_cpu_max()); 5937 break; 5938 case MOD_UNLOAD: 5939 case MOD_SHUTDOWN: 5940 pmc_cleanup(); 5941 PMCDBG0(MOD,INI,1, "unloaded"); 5942 break; 5943 default: 5944 error = EINVAL; 5945 break; 5946 } 5947 5948 return (error); 5949 } 5950