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 #define EXTERR_CATEGORY EXTERR_CAT_HWPMC_MOD 66 #include <sys/exterrvar.h> 67 68 #include <sys/linker.h> /* needs to be after <sys/malloc.h> */ 69 70 #include <machine/atomic.h> 71 #include <machine/md_var.h> 72 73 #include <vm/vm.h> 74 #include <vm/vm_extern.h> 75 #include <vm/pmap.h> 76 #include <vm/vm_map.h> 77 #include <vm/vm_object.h> 78 79 #include "hwpmc_soft.h" 80 81 #define PMC_EPOCH_ENTER() \ 82 struct epoch_tracker pmc_et; \ 83 epoch_enter_preempt(global_epoch_preempt, &pmc_et) 84 85 #define PMC_EPOCH_EXIT() \ 86 epoch_exit_preempt(global_epoch_preempt, &pmc_et) 87 88 /* 89 * Types 90 */ 91 92 enum pmc_flags { 93 PMC_FLAG_NONE = 0x00, /* do nothing */ 94 PMC_FLAG_REMOVE = 0x01, /* atomically remove entry from hash */ 95 PMC_FLAG_ALLOCATE = 0x02, /* add entry to hash if not found */ 96 PMC_FLAG_NOWAIT = 0x04, /* do not wait for mallocs */ 97 }; 98 99 /* 100 * The offset in sysent where the syscall is allocated. 101 */ 102 static int pmc_syscall_num = NO_SYSCALL; 103 104 struct pmc_cpu **pmc_pcpu; /* per-cpu state */ 105 pmc_value_t *pmc_pcpu_saved; /* saved PMC values: CSW handling */ 106 107 #define PMC_PCPU_SAVED(C, R) pmc_pcpu_saved[(R) + md->pmd_npmc * (C)] 108 109 struct mtx_pool *pmc_mtxpool; 110 static int *pmc_pmcdisp; /* PMC row dispositions */ 111 112 #define PMC_ROW_DISP_IS_FREE(R) (pmc_pmcdisp[(R)] == 0) 113 #define PMC_ROW_DISP_IS_THREAD(R) (pmc_pmcdisp[(R)] > 0) 114 #define PMC_ROW_DISP_IS_STANDALONE(R) (pmc_pmcdisp[(R)] < 0) 115 116 #define PMC_MARK_ROW_FREE(R) do { \ 117 pmc_pmcdisp[(R)] = 0; \ 118 } while (0) 119 120 #define PMC_MARK_ROW_STANDALONE(R) do { \ 121 KASSERT(pmc_pmcdisp[(R)] <= 0, ("[pmc,%d] row disposition error", \ 122 __LINE__)); \ 123 atomic_add_int(&pmc_pmcdisp[(R)], -1); \ 124 KASSERT(pmc_pmcdisp[(R)] >= (-pmc_cpu_max_active()), \ 125 ("[pmc,%d] row disposition error", __LINE__)); \ 126 } while (0) 127 128 #define PMC_UNMARK_ROW_STANDALONE(R) do { \ 129 atomic_add_int(&pmc_pmcdisp[(R)], 1); \ 130 KASSERT(pmc_pmcdisp[(R)] <= 0, ("[pmc,%d] row disposition error", \ 131 __LINE__)); \ 132 } while (0) 133 134 #define PMC_MARK_ROW_THREAD(R) do { \ 135 KASSERT(pmc_pmcdisp[(R)] >= 0, ("[pmc,%d] row disposition error", \ 136 __LINE__)); \ 137 atomic_add_int(&pmc_pmcdisp[(R)], 1); \ 138 } while (0) 139 140 #define PMC_UNMARK_ROW_THREAD(R) do { \ 141 atomic_add_int(&pmc_pmcdisp[(R)], -1); \ 142 KASSERT(pmc_pmcdisp[(R)] >= 0, ("[pmc,%d] row disposition error", \ 143 __LINE__)); \ 144 } while (0) 145 146 /* various event handlers */ 147 static eventhandler_tag pmc_exit_tag, pmc_fork_tag, pmc_kld_load_tag, 148 pmc_kld_unload_tag; 149 150 /* Module statistics */ 151 struct pmc_driverstats pmc_stats; 152 153 /* Machine/processor dependent operations */ 154 static struct pmc_mdep *md; 155 156 /* 157 * Hash tables mapping owner processes and target threads to PMCs. 158 */ 159 struct mtx pmc_processhash_mtx; /* spin mutex */ 160 static u_long pmc_processhashmask; 161 static LIST_HEAD(pmc_processhash, pmc_process) *pmc_processhash; 162 163 /* 164 * Hash table of PMC owner descriptors. This table is protected by 165 * the shared PMC "sx" lock. 166 */ 167 static u_long pmc_ownerhashmask; 168 static LIST_HEAD(pmc_ownerhash, pmc_owner) *pmc_ownerhash; 169 170 /* 171 * List of PMC owners with system-wide sampling PMCs. 172 */ 173 static CK_LIST_HEAD(, pmc_owner) pmc_ss_owners; 174 175 /* 176 * List of free thread entries. This is protected by the spin 177 * mutex. 178 */ 179 static struct mtx pmc_threadfreelist_mtx; /* spin mutex */ 180 static LIST_HEAD(, pmc_thread) pmc_threadfreelist; 181 static int pmc_threadfreelist_entries = 0; 182 #define THREADENTRY_SIZE (sizeof(struct pmc_thread) + \ 183 (md->pmd_npmc * sizeof(struct pmc_threadpmcstate))) 184 185 /* 186 * Task to free thread descriptors 187 */ 188 static struct task free_task; 189 190 /* 191 * A map of row indices to classdep structures. 192 */ 193 static struct pmc_classdep **pmc_rowindex_to_classdep; 194 195 /* 196 * Prototypes 197 */ 198 199 #ifdef HWPMC_DEBUG 200 static int pmc_debugflags_sysctl_handler(SYSCTL_HANDLER_ARGS); 201 static int pmc_debugflags_parse(char *newstr, char *fence); 202 #endif 203 204 static void pmc_multipart_add(struct pmc_sample *ps, int type, 205 int length); 206 static void pmc_multipart_copydata(struct pmc_sample *ps, 207 struct pmc_multipart *mp); 208 209 static int load(struct module *module, int cmd, void *arg); 210 static int pmc_add_sample(ring_type_t ring, struct pmc *pm, 211 struct trapframe *tf, struct pmc_multipart *mp); 212 static void pmc_add_thread_descriptors_from_proc(struct proc *p, 213 struct pmc_process *pp); 214 static int pmc_attach_process(struct proc *p, struct pmc *pm); 215 static struct pmc *pmc_allocate_pmc_descriptor(void); 216 static struct pmc_owner *pmc_allocate_owner_descriptor(struct proc *p); 217 static int pmc_attach_one_process(struct proc *p, struct pmc *pm); 218 static bool pmc_can_allocate_row(int ri, enum pmc_mode mode); 219 static bool pmc_can_allocate_rowindex(struct proc *p, unsigned int ri, 220 int cpu); 221 static bool pmc_can_attach(struct pmc *pm, struct proc *p); 222 static void pmc_capture_user_callchain(int cpu, int soft, 223 struct trapframe *tf); 224 static void pmc_cleanup(void); 225 static int pmc_detach_process(struct proc *p, struct pmc *pm); 226 static int pmc_detach_one_process(struct proc *p, struct pmc *pm, 227 int flags); 228 static void pmc_destroy_owner_descriptor(struct pmc_owner *po); 229 static void pmc_destroy_pmc_descriptor(struct pmc *pm); 230 static void pmc_destroy_process_descriptor(struct pmc_process *pp); 231 static void pmc_reclaim_pmc_from_cpu(struct pmc *pm, 232 struct pmc_process *pp, int cpu); 233 static struct pmc_owner *pmc_find_owner_descriptor(struct proc *p); 234 static int pmc_find_pmc(pmc_id_t pmcid, struct pmc **pm); 235 static struct pmc *pmc_find_pmc_descriptor_in_process(struct pmc_owner *po, 236 pmc_id_t pmc); 237 static struct pmc_process *pmc_find_process_descriptor(struct proc *p, 238 uint32_t mode); 239 static struct pmc_thread *pmc_find_thread_descriptor(struct pmc_process *pp, 240 struct thread *td, uint32_t mode); 241 static void pmc_force_context_switch(void); 242 static void pmc_link_target_process(struct pmc *pm, 243 struct pmc_process *pp); 244 static void pmc_log_all_process_mappings(struct pmc_owner *po); 245 static void pmc_log_kernel_mappings(struct pmc *pm); 246 static void pmc_log_process_mappings(struct pmc_owner *po, struct proc *p); 247 static void pmc_maybe_remove_owner(struct pmc_owner *po); 248 static void pmc_post_callchain_callback(void); 249 static void pmc_process_allproc(struct pmc *pm); 250 static void pmc_process_csw_in(struct thread *td); 251 static void pmc_process_csw_out(struct thread *td); 252 static void pmc_process_exec(struct thread *td, 253 struct pmckern_procexec *pk); 254 static void pmc_process_exit(void *arg, struct proc *p); 255 static void pmc_process_fork(void *arg, struct proc *p1, 256 struct proc *p2, int n); 257 static void pmc_process_proccreate(struct proc *p); 258 static void pmc_process_samples(int cpu, ring_type_t soft); 259 static void pmc_process_threadcreate(struct thread *td); 260 static void pmc_process_threadexit(struct thread *td); 261 static void pmc_process_thread_add(struct thread *td); 262 static void pmc_process_thread_delete(struct thread *td); 263 static void pmc_process_thread_userret(struct thread *td); 264 static void pmc_release_pmc_descriptor(struct pmc *pmc); 265 static void pmc_remove_owner(struct pmc_owner *po); 266 static void pmc_remove_process_descriptor(struct pmc_process *pp); 267 static int pmc_start(struct pmc *pm); 268 static int pmc_stop(struct pmc *pm); 269 static int pmc_syscall_handler(struct thread *td, void *syscall_args); 270 static struct pmc_thread *pmc_thread_descriptor_pool_alloc(void); 271 static void pmc_thread_descriptor_pool_drain(void); 272 static void pmc_thread_descriptor_pool_free(struct pmc_thread *pt); 273 static void pmc_unlink_target_process(struct pmc *pmc, 274 struct pmc_process *pp); 275 276 static int generic_switch_in(struct pmc_cpu *pc, struct pmc_process *pp); 277 static int generic_switch_out(struct pmc_cpu *pc, struct pmc_process *pp); 278 static struct pmc_mdep *pmc_generic_cpu_initialize(void); 279 static void pmc_generic_cpu_finalize(struct pmc_mdep *md); 280 281 /* 282 * Kernel tunables and sysctl(8) interface. 283 */ 284 285 SYSCTL_DECL(_kern_hwpmc); 286 SYSCTL_NODE(_kern_hwpmc, OID_AUTO, stats, CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 287 "HWPMC stats"); 288 289 /* Stats. */ 290 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, intr_ignored, CTLFLAG_RW, 291 &pmc_stats.pm_intr_ignored, 292 "# of interrupts ignored"); 293 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, intr_processed, CTLFLAG_RW, 294 &pmc_stats.pm_intr_processed, 295 "# of interrupts processed"); 296 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, intr_bufferfull, CTLFLAG_RW, 297 &pmc_stats.pm_intr_bufferfull, 298 "# of interrupts where buffer was full"); 299 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, syscalls, CTLFLAG_RW, 300 &pmc_stats.pm_syscalls, 301 "# of syscalls"); 302 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, syscall_errors, CTLFLAG_RW, 303 &pmc_stats.pm_syscall_errors, 304 "# of syscall_errors"); 305 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, buffer_requests, CTLFLAG_RW, 306 &pmc_stats.pm_buffer_requests, 307 "# of buffer requests"); 308 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, buffer_requests_failed, 309 CTLFLAG_RW, &pmc_stats.pm_buffer_requests_failed, 310 "# of buffer requests which failed"); 311 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, log_sweeps, CTLFLAG_RW, 312 &pmc_stats.pm_log_sweeps, 313 "# of times samples were processed"); 314 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, merges, CTLFLAG_RW, 315 &pmc_stats.pm_merges, 316 "# of times kernel stack was found for user trace"); 317 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, overwrites, CTLFLAG_RW, 318 &pmc_stats.pm_overwrites, 319 "# of times a sample was overwritten before being logged"); 320 321 static int pmc_callchaindepth = PMC_CALLCHAIN_DEPTH; 322 SYSCTL_INT(_kern_hwpmc, OID_AUTO, callchaindepth, CTLFLAG_RDTUN, 323 &pmc_callchaindepth, 0, 324 "depth of call chain records"); 325 326 char pmc_cpuid[PMC_CPUID_LEN]; 327 SYSCTL_STRING(_kern_hwpmc, OID_AUTO, cpuid, CTLFLAG_RD, 328 pmc_cpuid, 0, 329 "cpu version string"); 330 331 #ifdef HWPMC_DEBUG 332 struct pmc_debugflags pmc_debugflags = PMC_DEBUG_DEFAULT_FLAGS; 333 char pmc_debugstr[PMC_DEBUG_STRSIZE]; 334 TUNABLE_STR(PMC_SYSCTL_NAME_PREFIX "debugflags", pmc_debugstr, 335 sizeof(pmc_debugstr)); 336 SYSCTL_PROC(_kern_hwpmc, OID_AUTO, debugflags, 337 CTLTYPE_STRING | CTLFLAG_RWTUN | CTLFLAG_NOFETCH | CTLFLAG_MPSAFE, 338 0, 0, pmc_debugflags_sysctl_handler, "A", 339 "debug flags"); 340 #endif 341 342 /* 343 * kern.hwpmc.hashsize -- determines the number of rows in the 344 * of the hash table used to look up threads 345 */ 346 static int pmc_hashsize = PMC_HASH_SIZE; 347 SYSCTL_INT(_kern_hwpmc, OID_AUTO, hashsize, CTLFLAG_RDTUN, 348 &pmc_hashsize, 0, 349 "rows in hash tables"); 350 351 /* 352 * kern.hwpmc.nsamples --- number of PC samples/callchain stacks per CPU 353 */ 354 static int pmc_nsamples = PMC_NSAMPLES; 355 SYSCTL_INT(_kern_hwpmc, OID_AUTO, nsamples, CTLFLAG_RDTUN, 356 &pmc_nsamples, 0, 357 "number of PC samples per CPU"); 358 359 static uint64_t pmc_sample_mask = PMC_NSAMPLES - 1; 360 361 /* 362 * kern.hwpmc.mtxpoolsize -- number of mutexes in the mutex pool. 363 */ 364 static int pmc_mtxpool_size = PMC_MTXPOOL_SIZE; 365 SYSCTL_INT(_kern_hwpmc, OID_AUTO, mtxpoolsize, CTLFLAG_RDTUN, 366 &pmc_mtxpool_size, 0, 367 "size of spin mutex pool"); 368 369 /* 370 * kern.hwpmc.threadfreelist_entries -- number of free entries 371 */ 372 SYSCTL_INT(_kern_hwpmc, OID_AUTO, threadfreelist_entries, CTLFLAG_RD, 373 &pmc_threadfreelist_entries, 0, 374 "number of available thread entries"); 375 376 /* 377 * kern.hwpmc.threadfreelist_max -- maximum number of free entries 378 */ 379 static int pmc_threadfreelist_max = PMC_THREADLIST_MAX; 380 SYSCTL_INT(_kern_hwpmc, OID_AUTO, threadfreelist_max, CTLFLAG_RW, 381 &pmc_threadfreelist_max, 0, 382 "maximum number of available thread entries before freeing some"); 383 384 /* 385 * kern.hwpmc.mincount -- minimum sample count 386 */ 387 static u_int pmc_mincount = 1000; 388 SYSCTL_INT(_kern_hwpmc, OID_AUTO, mincount, CTLFLAG_RWTUN, 389 &pmc_mincount, 0, 390 "minimum count for sampling counters"); 391 392 /* 393 * security.bsd.unprivileged_syspmcs -- allow non-root processes to 394 * allocate system-wide PMCs. 395 * 396 * Allowing unprivileged processes to allocate system PMCs is convenient 397 * if system-wide measurements need to be taken concurrently with other 398 * per-process measurements. This feature is turned off by default. 399 */ 400 static int pmc_unprivileged_syspmcs = 0; 401 SYSCTL_INT(_security_bsd, OID_AUTO, unprivileged_syspmcs, CTLFLAG_RWTUN, 402 &pmc_unprivileged_syspmcs, 0, 403 "allow unprivileged process to allocate system PMCs"); 404 405 /* 406 * Hash function. Discard the lower 2 bits of the pointer since 407 * these are always zero for our uses. The hash multiplier is 408 * round((2^LONG_BIT) * ((sqrt(5)-1)/2)). 409 */ 410 #if LONG_BIT == 64 411 #define _PMC_HM 11400714819323198486u 412 #elif LONG_BIT == 32 413 #define _PMC_HM 2654435769u 414 #else 415 #error Must know the size of 'long' to compile 416 #endif 417 418 #define PMC_HASH_PTR(P,M) ((((unsigned long) (P) >> 2) * _PMC_HM) & (M)) 419 420 /* 421 * Syscall structures 422 */ 423 424 /* The `sysent' for the new syscall */ 425 static struct sysent pmc_sysent = { 426 .sy_narg = 2, 427 .sy_call = pmc_syscall_handler, 428 }; 429 430 static struct syscall_module_data pmc_syscall_mod = { 431 .chainevh = load, 432 .chainarg = NULL, 433 .offset = &pmc_syscall_num, 434 .new_sysent = &pmc_sysent, 435 .old_sysent = { .sy_narg = 0, .sy_call = NULL }, 436 .flags = SY_THR_STATIC_KLD, 437 }; 438 439 static moduledata_t pmc_mod = { 440 .name = PMC_MODULE_NAME, 441 .evhand = syscall_module_handler, 442 .priv = &pmc_syscall_mod, 443 }; 444 445 #ifdef EARLY_AP_STARTUP 446 DECLARE_MODULE(pmc, pmc_mod, SI_SUB_SYSCALLS, SI_ORDER_ANY); 447 #else 448 DECLARE_MODULE(pmc, pmc_mod, SI_SUB_SMP, SI_ORDER_ANY); 449 #endif 450 MODULE_VERSION(pmc, PMC_VERSION); 451 452 #ifdef HWPMC_DEBUG 453 enum pmc_dbgparse_state { 454 PMCDS_WS, /* in whitespace */ 455 PMCDS_MAJOR, /* seen a major keyword */ 456 PMCDS_MINOR 457 }; 458 459 static int 460 pmc_debugflags_parse(char *newstr, char *fence) 461 { 462 struct pmc_debugflags *tmpflags; 463 size_t kwlen; 464 char c, *p, *q; 465 int error, *newbits, tmp; 466 int found; 467 468 tmpflags = malloc(sizeof(*tmpflags), M_PMC, M_WAITOK | M_ZERO); 469 470 error = 0; 471 for (p = newstr; p < fence && (c = *p); p++) { 472 /* skip white space */ 473 if (c == ' ' || c == '\t') 474 continue; 475 476 /* look for a keyword followed by "=" */ 477 for (q = p; p < fence && (c = *p) && c != '='; p++) 478 ; 479 if (c != '=') { 480 error = EINVAL; 481 goto done; 482 } 483 484 kwlen = p - q; 485 newbits = NULL; 486 487 /* lookup flag group name */ 488 #define DBG_SET_FLAG_MAJ(S,F) \ 489 if (kwlen == sizeof(S)-1 && strncmp(q, S, kwlen) == 0) \ 490 newbits = &tmpflags->pdb_ ## F; 491 492 DBG_SET_FLAG_MAJ("cpu", CPU); 493 DBG_SET_FLAG_MAJ("csw", CSW); 494 DBG_SET_FLAG_MAJ("logging", LOG); 495 DBG_SET_FLAG_MAJ("module", MOD); 496 DBG_SET_FLAG_MAJ("md", MDP); 497 DBG_SET_FLAG_MAJ("owner", OWN); 498 DBG_SET_FLAG_MAJ("pmc", PMC); 499 DBG_SET_FLAG_MAJ("process", PRC); 500 DBG_SET_FLAG_MAJ("sampling", SAM); 501 #undef DBG_SET_FLAG_MAJ 502 503 if (newbits == NULL) { 504 error = EINVAL; 505 goto done; 506 } 507 508 p++; /* skip the '=' */ 509 510 /* Now parse the individual flags */ 511 tmp = 0; 512 newflag: 513 for (q = p; p < fence && (c = *p); p++) 514 if (c == ' ' || c == '\t' || c == ',') 515 break; 516 517 /* p == fence or c == ws or c == "," or c == 0 */ 518 519 if ((kwlen = p - q) == 0) { 520 *newbits = tmp; 521 continue; 522 } 523 524 found = 0; 525 #define DBG_SET_FLAG_MIN(S,F) \ 526 if (kwlen == sizeof(S)-1 && strncmp(q, S, kwlen) == 0) \ 527 tmp |= found = (1 << PMC_DEBUG_MIN_ ## F) 528 529 /* a '*' denotes all possible flags in the group */ 530 if (kwlen == 1 && *q == '*') 531 tmp = found = ~0; 532 /* look for individual flag names */ 533 DBG_SET_FLAG_MIN("allocaterow", ALR); 534 DBG_SET_FLAG_MIN("allocate", ALL); 535 DBG_SET_FLAG_MIN("attach", ATT); 536 DBG_SET_FLAG_MIN("bind", BND); 537 DBG_SET_FLAG_MIN("config", CFG); 538 DBG_SET_FLAG_MIN("exec", EXC); 539 DBG_SET_FLAG_MIN("exit", EXT); 540 DBG_SET_FLAG_MIN("find", FND); 541 DBG_SET_FLAG_MIN("flush", FLS); 542 DBG_SET_FLAG_MIN("fork", FRK); 543 DBG_SET_FLAG_MIN("getbuf", GTB); 544 DBG_SET_FLAG_MIN("hook", PMH); 545 DBG_SET_FLAG_MIN("init", INI); 546 DBG_SET_FLAG_MIN("intr", INT); 547 DBG_SET_FLAG_MIN("linktarget", TLK); 548 DBG_SET_FLAG_MIN("mayberemove", OMR); 549 DBG_SET_FLAG_MIN("ops", OPS); 550 DBG_SET_FLAG_MIN("read", REA); 551 DBG_SET_FLAG_MIN("register", REG); 552 DBG_SET_FLAG_MIN("release", REL); 553 DBG_SET_FLAG_MIN("remove", ORM); 554 DBG_SET_FLAG_MIN("sample", SAM); 555 DBG_SET_FLAG_MIN("scheduleio", SIO); 556 DBG_SET_FLAG_MIN("select", SEL); 557 DBG_SET_FLAG_MIN("signal", SIG); 558 DBG_SET_FLAG_MIN("swi", SWI); 559 DBG_SET_FLAG_MIN("swo", SWO); 560 DBG_SET_FLAG_MIN("start", STA); 561 DBG_SET_FLAG_MIN("stop", STO); 562 DBG_SET_FLAG_MIN("syscall", PMS); 563 DBG_SET_FLAG_MIN("unlinktarget", TUL); 564 DBG_SET_FLAG_MIN("write", WRI); 565 #undef DBG_SET_FLAG_MIN 566 if (found == 0) { 567 /* unrecognized flag name */ 568 error = EINVAL; 569 goto done; 570 } 571 572 if (c == 0 || c == ' ' || c == '\t') { /* end of flag group */ 573 *newbits = tmp; 574 continue; 575 } 576 577 p++; 578 goto newflag; 579 } 580 581 /* save the new flag set */ 582 bcopy(tmpflags, &pmc_debugflags, sizeof(pmc_debugflags)); 583 done: 584 free(tmpflags, M_PMC); 585 return (error); 586 } 587 588 static int 589 pmc_debugflags_sysctl_handler(SYSCTL_HANDLER_ARGS) 590 { 591 char *fence, *newstr; 592 int error; 593 u_int n; 594 595 n = sizeof(pmc_debugstr); 596 newstr = malloc(n, M_PMC, M_WAITOK | M_ZERO); 597 strlcpy(newstr, pmc_debugstr, n); 598 599 error = sysctl_handle_string(oidp, newstr, n, req); 600 601 /* if there is a new string, parse and copy it */ 602 if (error == 0 && req->newptr != NULL) { 603 fence = newstr + (n < req->newlen ? n : req->newlen + 1); 604 error = pmc_debugflags_parse(newstr, fence); 605 if (error == 0) 606 strlcpy(pmc_debugstr, newstr, sizeof(pmc_debugstr)); 607 } 608 free(newstr, M_PMC); 609 610 return (error); 611 } 612 #endif 613 614 /* 615 * Map a row index to a classdep structure and return the adjusted row 616 * index for the PMC class index. 617 */ 618 static struct pmc_classdep * 619 pmc_ri_to_classdep(struct pmc_mdep *md __unused, int ri, int *adjri) 620 { 621 struct pmc_classdep *pcd; 622 623 KASSERT(ri >= 0 && ri < md->pmd_npmc, 624 ("[pmc,%d] illegal row-index %d", __LINE__, ri)); 625 626 pcd = pmc_rowindex_to_classdep[ri]; 627 KASSERT(pcd != NULL, 628 ("[pmc,%d] ri %d null pcd", __LINE__, ri)); 629 630 *adjri = ri - pcd->pcd_ri; 631 KASSERT(*adjri >= 0 && *adjri < pcd->pcd_num, 632 ("[pmc,%d] adjusted row-index %d", __LINE__, *adjri)); 633 634 return (pcd); 635 } 636 637 /* 638 * Concurrency Control 639 * 640 * The driver manages the following data structures: 641 * 642 * - target process descriptors, one per target process 643 * - owner process descriptors (and attached lists), one per owner process 644 * - lookup hash tables for owner and target processes 645 * - PMC descriptors (and attached lists) 646 * - per-cpu hardware state 647 * - the 'hook' variable through which the kernel calls into 648 * this module 649 * - the machine hardware state (managed by the MD layer) 650 * 651 * These data structures are accessed from: 652 * 653 * - thread context-switch code 654 * - interrupt handlers (possibly on multiple cpus) 655 * - kernel threads on multiple cpus running on behalf of user 656 * processes doing system calls 657 * - this driver's private kernel threads 658 * 659 * = Locks and Locking strategy = 660 * 661 * The driver uses four locking strategies for its operation: 662 * 663 * - The global SX lock "pmc_sx" is used to protect internal 664 * data structures. 665 * 666 * Calls into the module by syscall() start with this lock being 667 * held in exclusive mode. Depending on the requested operation, 668 * the lock may be downgraded to 'shared' mode to allow more 669 * concurrent readers into the module. Calls into the module from 670 * other parts of the kernel acquire the lock in shared mode. 671 * 672 * This SX lock is held in exclusive mode for any operations that 673 * modify the linkages between the driver's internal data structures. 674 * 675 * The 'pmc_hook' function pointer is also protected by this lock. 676 * It is only examined with the sx lock held in exclusive mode. The 677 * kernel module is allowed to be unloaded only with the sx lock held 678 * in exclusive mode. In normal syscall handling, after acquiring the 679 * pmc_sx lock we first check that 'pmc_hook' is non-null before 680 * proceeding. This prevents races between the thread unloading the module 681 * and other threads seeking to use the module. 682 * 683 * - Lookups of target process structures and owner process structures 684 * cannot use the global "pmc_sx" SX lock because these lookups need 685 * to happen during context switches and in other critical sections 686 * where sleeping is not allowed. We protect these lookup tables 687 * with their own private spin-mutexes, "pmc_processhash_mtx" and 688 * "pmc_ownerhash_mtx". 689 * 690 * - Interrupt handlers work in a lock free manner. At interrupt 691 * time, handlers look at the PMC pointer (phw->phw_pmc) configured 692 * when the PMC was started. If this pointer is NULL, the interrupt 693 * is ignored after updating driver statistics. We ensure that this 694 * pointer is set (using an atomic operation if necessary) before the 695 * PMC hardware is started. Conversely, this pointer is unset atomically 696 * only after the PMC hardware is stopped. 697 * 698 * We ensure that everything needed for the operation of an 699 * interrupt handler is available without it needing to acquire any 700 * locks. We also ensure that a PMC's software state is destroyed only 701 * after the PMC is taken off hardware (on all CPUs). 702 * 703 * - Context-switch handling with process-private PMCs needs more 704 * care. 705 * 706 * A given process may be the target of multiple PMCs. For example, 707 * PMCATTACH and PMCDETACH may be requested by a process on one CPU 708 * while the target process is running on another. A PMC could also 709 * be getting released because its owner is exiting. We tackle 710 * these situations in the following manner: 711 * 712 * - each target process structure 'pmc_process' has an array 713 * of 'struct pmc *' pointers, one for each hardware PMC. 714 * 715 * - At context switch IN time, each "target" PMC in RUNNING state 716 * gets started on hardware and a pointer to each PMC is copied into 717 * the per-cpu phw array. The 'runcount' for the PMC is 718 * incremented. 719 * 720 * - At context switch OUT time, all process-virtual PMCs are stopped 721 * on hardware. The saved value is added to the PMCs value field 722 * only if the PMC is in a non-deleted state (the PMCs state could 723 * have changed during the current time slice). 724 * 725 * Note that since in-between a switch IN on a processor and a switch 726 * OUT, the PMC could have been released on another CPU. Therefore 727 * context switch OUT always looks at the hardware state to turn 728 * OFF PMCs and will update a PMC's saved value only if reachable 729 * from the target process record. 730 * 731 * - OP PMCRELEASE could be called on a PMC at any time (the PMC could 732 * be attached to many processes at the time of the call and could 733 * be active on multiple CPUs). 734 * 735 * We prevent further scheduling of the PMC by marking it as in 736 * state 'DELETED'. If the runcount of the PMC is non-zero then 737 * this PMC is currently running on a CPU somewhere. The thread 738 * doing the PMCRELEASE operation waits by repeatedly doing a 739 * pause() till the runcount comes to zero. 740 * 741 * The contents of a PMC descriptor (struct pmc) are protected using 742 * a spin-mutex. In order to save space, we use a mutex pool. 743 * 744 * In terms of lock types used by witness(4), we use: 745 * - Type "pmc-sx", used by the global SX lock. 746 * - Type "pmc-sleep", for sleep mutexes used by logger threads. 747 * - Type "pmc-per-proc", for protecting PMC owner descriptors. 748 * - Type "pmc-leaf", used for all other spin mutexes. 749 */ 750 751 /* 752 * Save the CPU binding of the current kthread. 753 */ 754 void 755 pmc_save_cpu_binding(struct pmc_binding *pb) 756 { 757 PMCDBG0(CPU,BND,2, "save-cpu"); 758 thread_lock(curthread); 759 pb->pb_bound = sched_is_bound(curthread); 760 pb->pb_cpu = curthread->td_oncpu; 761 pb->pb_priority = curthread->td_priority; 762 thread_unlock(curthread); 763 PMCDBG1(CPU,BND,2, "save-cpu cpu=%d", pb->pb_cpu); 764 } 765 766 /* 767 * Restore the CPU binding of the current thread. 768 */ 769 void 770 pmc_restore_cpu_binding(struct pmc_binding *pb) 771 { 772 PMCDBG2(CPU,BND,2, "restore-cpu curcpu=%d restore=%d", 773 curthread->td_oncpu, pb->pb_cpu); 774 thread_lock(curthread); 775 sched_bind(curthread, pb->pb_cpu); 776 if (!pb->pb_bound) 777 sched_unbind(curthread); 778 sched_prio(curthread, pb->pb_priority); 779 thread_unlock(curthread); 780 PMCDBG0(CPU,BND,2, "restore-cpu done"); 781 } 782 783 /* 784 * Move execution over to the specified CPU and bind it there. 785 */ 786 void 787 pmc_select_cpu(int cpu) 788 { 789 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 790 ("[pmc,%d] bad cpu number %d", __LINE__, cpu)); 791 792 /* Never move to an inactive CPU. */ 793 KASSERT(pmc_cpu_is_active(cpu), ("[pmc,%d] selecting inactive " 794 "CPU %d", __LINE__, cpu)); 795 796 PMCDBG1(CPU,SEL,2, "select-cpu cpu=%d", cpu); 797 thread_lock(curthread); 798 sched_prio(curthread, PRI_MIN); 799 sched_bind(curthread, cpu); 800 thread_unlock(curthread); 801 802 KASSERT(curthread->td_oncpu == cpu, 803 ("[pmc,%d] CPU not bound [cpu=%d, curr=%d]", __LINE__, 804 cpu, curthread->td_oncpu)); 805 806 PMCDBG1(CPU,SEL,2, "select-cpu cpu=%d ok", cpu); 807 } 808 809 /* 810 * Force a context switch. 811 * 812 * We do this by pause'ing for 1 tick -- invoking mi_switch() is not 813 * guaranteed to force a context switch. 814 */ 815 static void 816 pmc_force_context_switch(void) 817 { 818 819 pause("pmcctx", 1); 820 } 821 822 uint64_t 823 pmc_rdtsc(void) 824 { 825 #if defined(__i386__) 826 /* Unfortunately get_cyclecount on i386 uses cpu_ticks. */ 827 return (rdtsc()); 828 #else 829 return (get_cyclecount()); 830 #endif 831 } 832 833 /* 834 * Get the file name for an executable. This is a simple wrapper 835 * around vn_fullpath(9). 836 */ 837 static void 838 pmc_getfilename(struct vnode *v, char **fullpath, char **freepath) 839 { 840 841 *fullpath = "unknown"; 842 *freepath = NULL; 843 vn_fullpath(v, fullpath, freepath); 844 } 845 846 /* 847 * Remove a process owning PMCs. 848 */ 849 void 850 pmc_remove_owner(struct pmc_owner *po) 851 { 852 struct pmc *pm, *tmp; 853 854 sx_assert(&pmc_sx, SX_XLOCKED); 855 856 PMCDBG1(OWN,ORM,1, "remove-owner po=%p", po); 857 858 /* Remove descriptor from the owner hash table */ 859 LIST_REMOVE(po, po_next); 860 861 /* release all owned PMC descriptors */ 862 LIST_FOREACH_SAFE(pm, &po->po_pmcs, pm_next, tmp) { 863 PMCDBG1(OWN,ORM,2, "pmc=%p", pm); 864 KASSERT(pm->pm_owner == po, 865 ("[pmc,%d] owner %p != po %p", __LINE__, pm->pm_owner, po)); 866 867 pmc_release_pmc_descriptor(pm); /* will unlink from the list */ 868 pmc_destroy_pmc_descriptor(pm); 869 } 870 871 KASSERT(po->po_sscount == 0, 872 ("[pmc,%d] SS count not zero", __LINE__)); 873 KASSERT(LIST_EMPTY(&po->po_pmcs), 874 ("[pmc,%d] PMC list not empty", __LINE__)); 875 876 /* de-configure the log file if present */ 877 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 878 pmclog_deconfigure_log(po); 879 } 880 881 /* 882 * Remove an owner process record if all conditions are met. 883 */ 884 static void 885 pmc_maybe_remove_owner(struct pmc_owner *po) 886 { 887 888 PMCDBG1(OWN,OMR,1, "maybe-remove-owner po=%p", po); 889 890 /* 891 * Remove owner record if 892 * - this process does not own any PMCs 893 * - this process has not allocated a system-wide sampling buffer 894 */ 895 if (LIST_EMPTY(&po->po_pmcs) && 896 ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0)) { 897 pmc_remove_owner(po); 898 pmc_destroy_owner_descriptor(po); 899 } 900 } 901 902 /* 903 * Add an association between a target process and a PMC. 904 */ 905 static void 906 pmc_link_target_process(struct pmc *pm, struct pmc_process *pp) 907 { 908 struct pmc_target *pt; 909 struct pmc_thread *pt_td __diagused; 910 int ri; 911 912 sx_assert(&pmc_sx, SX_XLOCKED); 913 KASSERT(pm != NULL && pp != NULL, 914 ("[pmc,%d] Null pm %p or pp %p", __LINE__, pm, pp)); 915 KASSERT(PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)), 916 ("[pmc,%d] Attaching a non-process-virtual pmc=%p to pid=%d", 917 __LINE__, pm, pp->pp_proc->p_pid)); 918 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= ((int) md->pmd_npmc - 1), 919 ("[pmc,%d] Illegal reference count %d for process record %p", 920 __LINE__, pp->pp_refcnt, (void *) pp)); 921 922 ri = PMC_TO_ROWINDEX(pm); 923 924 PMCDBG3(PRC,TLK,1, "link-target pmc=%p ri=%d pmc-process=%p", 925 pm, ri, pp); 926 927 #ifdef HWPMC_DEBUG 928 LIST_FOREACH(pt, &pm->pm_targets, pt_next) { 929 if (pt->pt_process == pp) 930 KASSERT(0, ("[pmc,%d] pp %p already in pmc %p targets", 931 __LINE__, pp, pm)); 932 } 933 #endif 934 pt = malloc(sizeof(struct pmc_target), M_PMC, M_WAITOK | M_ZERO); 935 pt->pt_process = pp; 936 937 LIST_INSERT_HEAD(&pm->pm_targets, pt, pt_next); 938 939 atomic_store_rel_ptr((uintptr_t *)&pp->pp_pmcs[ri].pp_pmc, 940 (uintptr_t)pm); 941 942 if (pm->pm_owner->po_owner == pp->pp_proc) 943 pm->pm_flags |= PMC_F_ATTACHED_TO_OWNER; 944 945 /* 946 * Initialize the per-process values at this row index. 947 */ 948 pp->pp_pmcs[ri].pp_pmcval = PMC_TO_MODE(pm) == PMC_MODE_TS ? 949 pm->pm_sc.pm_reloadcount : 0; 950 pp->pp_refcnt++; 951 952 #ifdef INVARIANTS 953 /* Confirm that the per-thread values at this row index are cleared. */ 954 if (PMC_TO_MODE(pm) == PMC_MODE_TS) { 955 mtx_lock_spin(pp->pp_tdslock); 956 LIST_FOREACH(pt_td, &pp->pp_tds, pt_next) { 957 KASSERT(pt_td->pt_pmcs[ri].pt_pmcval == (pmc_value_t) 0, 958 ("[pmc,%d] pt_pmcval not cleared for pid=%d at " 959 "ri=%d", __LINE__, pp->pp_proc->p_pid, ri)); 960 } 961 mtx_unlock_spin(pp->pp_tdslock); 962 } 963 #endif 964 } 965 966 /* 967 * Removes the association between a target process and a PMC. 968 */ 969 static void 970 pmc_unlink_target_process(struct pmc *pm, struct pmc_process *pp) 971 { 972 int ri; 973 struct proc *p; 974 struct pmc_target *ptgt; 975 struct pmc_thread *pt; 976 977 sx_assert(&pmc_sx, SX_XLOCKED); 978 979 KASSERT(pm != NULL && pp != NULL, 980 ("[pmc,%d] Null pm %p or pp %p", __LINE__, pm, pp)); 981 982 KASSERT(pp->pp_refcnt >= 1 && pp->pp_refcnt <= (int) md->pmd_npmc, 983 ("[pmc,%d] Illegal ref count %d on process record %p", 984 __LINE__, pp->pp_refcnt, (void *) pp)); 985 986 ri = PMC_TO_ROWINDEX(pm); 987 988 PMCDBG3(PRC,TUL,1, "unlink-target pmc=%p ri=%d pmc-process=%p", 989 pm, ri, pp); 990 991 KASSERT(pp->pp_pmcs[ri].pp_pmc == pm, 992 ("[pmc,%d] PMC ri %d mismatch pmc %p pp->[ri] %p", __LINE__, 993 ri, pm, pp->pp_pmcs[ri].pp_pmc)); 994 995 pp->pp_pmcs[ri].pp_pmc = NULL; 996 pp->pp_pmcs[ri].pp_pmcval = (pmc_value_t)0; 997 998 /* Clear the per-thread values at this row index. */ 999 if (PMC_TO_MODE(pm) == PMC_MODE_TS) { 1000 mtx_lock_spin(pp->pp_tdslock); 1001 LIST_FOREACH(pt, &pp->pp_tds, pt_next) 1002 pt->pt_pmcs[ri].pt_pmcval = (pmc_value_t)0; 1003 mtx_unlock_spin(pp->pp_tdslock); 1004 } 1005 1006 /* Remove owner-specific flags */ 1007 if (pm->pm_owner->po_owner == pp->pp_proc) { 1008 pp->pp_flags &= ~PMC_PP_ENABLE_MSR_ACCESS; 1009 pm->pm_flags &= ~PMC_F_ATTACHED_TO_OWNER; 1010 } 1011 1012 pp->pp_refcnt--; 1013 1014 /* Remove the target process from the PMC structure */ 1015 LIST_FOREACH(ptgt, &pm->pm_targets, pt_next) 1016 if (ptgt->pt_process == pp) 1017 break; 1018 1019 KASSERT(ptgt != NULL, ("[pmc,%d] process %p (pp: %p) not found " 1020 "in pmc %p", __LINE__, pp->pp_proc, pp, pm)); 1021 1022 LIST_REMOVE(ptgt, pt_next); 1023 free(ptgt, M_PMC); 1024 1025 /* if the PMC now lacks targets, send the owner a SIGIO */ 1026 if (LIST_EMPTY(&pm->pm_targets)) { 1027 p = pm->pm_owner->po_owner; 1028 PROC_LOCK(p); 1029 kern_psignal(p, SIGIO); 1030 PROC_UNLOCK(p); 1031 1032 PMCDBG2(PRC,SIG,2, "signalling proc=%p signal=%d", p, SIGIO); 1033 } 1034 } 1035 1036 /* 1037 * Check if PMC 'pm' may be attached to target process 't'. 1038 */ 1039 1040 static bool 1041 pmc_can_attach(struct pmc *pm, struct proc *t) 1042 { 1043 struct proc *o; /* pmc owner */ 1044 struct ucred *oc, *tc; /* owner, target credentials */ 1045 bool decline_attach; 1046 1047 /* 1048 * A PMC's owner can always attach that PMC to itself. 1049 */ 1050 1051 if ((o = pm->pm_owner->po_owner) == t) 1052 return (true); 1053 1054 PROC_LOCK(o); 1055 oc = o->p_ucred; 1056 crhold(oc); 1057 PROC_UNLOCK(o); 1058 1059 PROC_LOCK(t); 1060 tc = t->p_ucred; 1061 crhold(tc); 1062 PROC_UNLOCK(t); 1063 1064 /* 1065 * The effective uid of the PMC owner should match at least one 1066 * of the {effective,real,saved} uids of the target process. 1067 */ 1068 1069 decline_attach = oc->cr_uid != tc->cr_uid && 1070 oc->cr_uid != tc->cr_svuid && 1071 oc->cr_uid != tc->cr_ruid; 1072 1073 /* 1074 * Every one of the target's group ids, must be in the owner's 1075 * group list. 1076 */ 1077 for (int i = 0; !decline_attach && i < tc->cr_ngroups; i++) 1078 decline_attach = !groupmember(tc->cr_groups[i], oc); 1079 if (!decline_attach) 1080 decline_attach = !groupmember(tc->cr_gid, oc) || 1081 !groupmember(tc->cr_rgid, oc) || 1082 !groupmember(tc->cr_svgid, oc); 1083 1084 crfree(tc); 1085 crfree(oc); 1086 1087 return (!decline_attach); 1088 } 1089 1090 /* 1091 * Attach a process to a PMC. 1092 */ 1093 static int 1094 pmc_attach_one_process(struct proc *p, struct pmc *pm) 1095 { 1096 int ri, error; 1097 char *fullpath, *freepath; 1098 struct pmc_process *pp; 1099 1100 sx_assert(&pmc_sx, SX_XLOCKED); 1101 1102 PMCDBG5(PRC,ATT,2, "attach-one pm=%p ri=%d proc=%p (%d, %s)", pm, 1103 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 1104 1105 /* 1106 * Locate the process descriptor corresponding to process 'p', 1107 * allocating space as needed. 1108 * 1109 * Verify that rowindex 'pm_rowindex' is free in the process 1110 * descriptor. 1111 * 1112 * If not, allocate space for a descriptor and link the 1113 * process descriptor and PMC. 1114 */ 1115 ri = PMC_TO_ROWINDEX(pm); 1116 1117 /* mark process as using HWPMCs */ 1118 PROC_LOCK(p); 1119 p->p_flag |= P_HWPMC; 1120 PROC_UNLOCK(p); 1121 1122 if ((pp = pmc_find_process_descriptor(p, PMC_FLAG_ALLOCATE)) == NULL) { 1123 error = ENOMEM; 1124 goto fail; 1125 } 1126 1127 if (pp->pp_pmcs[ri].pp_pmc == pm) {/* already present at slot [ri] */ 1128 error = EEXIST; 1129 goto fail; 1130 } 1131 1132 if (pp->pp_pmcs[ri].pp_pmc != NULL) { 1133 error = EBUSY; 1134 goto fail; 1135 } 1136 1137 pmc_link_target_process(pm, pp); 1138 1139 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)) && 1140 (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) == 0) 1141 pm->pm_flags |= PMC_F_NEEDS_LOGFILE; 1142 1143 pm->pm_flags |= PMC_F_ATTACH_DONE; /* mark as attached */ 1144 1145 /* issue an attach event to a configured log file */ 1146 if (pm->pm_owner->po_flags & PMC_PO_OWNS_LOGFILE) { 1147 if (p->p_flag & P_KPROC) { 1148 fullpath = kernelname; 1149 freepath = NULL; 1150 } else { 1151 pmc_getfilename(p->p_textvp, &fullpath, &freepath); 1152 pmclog_process_pmcattach(pm, p->p_pid, fullpath); 1153 } 1154 free(freepath, M_TEMP); 1155 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 1156 pmc_log_process_mappings(pm->pm_owner, p); 1157 } 1158 1159 return (0); 1160 fail: 1161 PROC_LOCK(p); 1162 p->p_flag &= ~P_HWPMC; 1163 PROC_UNLOCK(p); 1164 return (error); 1165 } 1166 1167 /* 1168 * Attach a process and optionally its children 1169 */ 1170 static int 1171 pmc_attach_process(struct proc *p, struct pmc *pm) 1172 { 1173 int error; 1174 struct proc *top; 1175 1176 sx_assert(&pmc_sx, SX_XLOCKED); 1177 1178 PMCDBG5(PRC,ATT,1, "attach pm=%p ri=%d proc=%p (%d, %s)", pm, 1179 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 1180 1181 /* 1182 * If this PMC successfully allowed a GETMSR operation 1183 * in the past, disallow further ATTACHes. 1184 */ 1185 if ((pm->pm_flags & PMC_PP_ENABLE_MSR_ACCESS) != 0) 1186 return (EPERM); 1187 1188 if ((pm->pm_flags & PMC_F_DESCENDANTS) == 0) 1189 return (pmc_attach_one_process(p, pm)); 1190 1191 /* 1192 * Traverse all child processes, attaching them to 1193 * this PMC. 1194 */ 1195 sx_slock(&proctree_lock); 1196 1197 top = p; 1198 for (;;) { 1199 if ((error = pmc_attach_one_process(p, pm)) != 0) 1200 break; 1201 if (!LIST_EMPTY(&p->p_children)) 1202 p = LIST_FIRST(&p->p_children); 1203 else for (;;) { 1204 if (p == top) 1205 goto done; 1206 if (LIST_NEXT(p, p_sibling)) { 1207 p = LIST_NEXT(p, p_sibling); 1208 break; 1209 } 1210 p = p->p_pptr; 1211 } 1212 } 1213 1214 if (error != 0) 1215 (void)pmc_detach_process(top, pm); 1216 1217 done: 1218 sx_sunlock(&proctree_lock); 1219 return (error); 1220 } 1221 1222 /* 1223 * Detach a process from a PMC. If there are no other PMCs tracking 1224 * this process, remove the process structure from its hash table. If 1225 * 'flags' contains PMC_FLAG_REMOVE, then free the process structure. 1226 */ 1227 static int 1228 pmc_detach_one_process(struct proc *p, struct pmc *pm, int flags) 1229 { 1230 int ri; 1231 struct pmc_process *pp; 1232 1233 sx_assert(&pmc_sx, SX_XLOCKED); 1234 1235 KASSERT(pm != NULL, 1236 ("[pmc,%d] null pm pointer", __LINE__)); 1237 1238 ri = PMC_TO_ROWINDEX(pm); 1239 1240 PMCDBG6(PRC,ATT,2, "detach-one pm=%p ri=%d proc=%p (%d, %s) flags=0x%x", 1241 pm, ri, p, p->p_pid, p->p_comm, flags); 1242 1243 if ((pp = pmc_find_process_descriptor(p, 0)) == NULL) 1244 return (ESRCH); 1245 1246 if (pp->pp_pmcs[ri].pp_pmc != pm) 1247 return (EINVAL); 1248 1249 /* 1250 * If this is a process-virtual PMC that is still loaded on the 1251 * hardware of the CPU we are running on (the common case when a 1252 * process detaches a PMC from itself), take it off and drop its 1253 * runcount reference now. The reference is otherwise only 1254 * dropped by the switch-out reclaim, which the scheduler stops 1255 * calling once P_HWPMC is cleared below - leaking it and later 1256 * wedging pmc_wait_for_pmc_idle() at release time. 1257 */ 1258 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) { 1259 critical_enter(); 1260 pmc_reclaim_pmc_from_cpu(pm, pp, curthread->td_oncpu); 1261 critical_exit(); 1262 } 1263 1264 pmc_unlink_target_process(pm, pp); 1265 1266 /* Issue a detach entry if a log file is configured */ 1267 if (pm->pm_owner->po_flags & PMC_PO_OWNS_LOGFILE) 1268 pmclog_process_pmcdetach(pm, p->p_pid); 1269 1270 /* 1271 * If there are no PMCs targeting this process, we remove its 1272 * descriptor from the target hash table and unset the P_HWPMC 1273 * flag in the struct proc. 1274 */ 1275 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= (int) md->pmd_npmc, 1276 ("[pmc,%d] Illegal refcnt %d for process struct %p", 1277 __LINE__, pp->pp_refcnt, pp)); 1278 1279 if (pp->pp_refcnt != 0) /* still a target of some PMC */ 1280 return (0); 1281 1282 /* 1283 * This detach removed the process' last PMC and we are about to 1284 * clear P_HWPMC. If the detached PMC was its last target and is 1285 * still loaded on other CPUs (e.g. sibling threads of a 1286 * multi-threaded target, or a target running on another CPU), 1287 * drain those references first: the target is already unlinked so 1288 * it cannot reload the PMC, and P_HWPMC is still set so those 1289 * CPUs' switch-out reclaim still runs. Bounded by the target 1290 * threads being scheduled out. 1291 */ 1292 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)) && 1293 LIST_EMPTY(&pm->pm_targets)) { 1294 while (counter_u64_fetch(pm->pm_runcount) > 0) 1295 pmc_force_context_switch(); 1296 } 1297 1298 pmc_remove_process_descriptor(pp); 1299 1300 if (flags & PMC_FLAG_REMOVE) 1301 pmc_destroy_process_descriptor(pp); 1302 1303 PROC_LOCK(p); 1304 p->p_flag &= ~P_HWPMC; 1305 PROC_UNLOCK(p); 1306 1307 return (0); 1308 } 1309 1310 /* 1311 * Detach a process and optionally its descendants from a PMC. 1312 */ 1313 static int 1314 pmc_detach_process(struct proc *p, struct pmc *pm) 1315 { 1316 struct proc *top; 1317 1318 sx_assert(&pmc_sx, SX_XLOCKED); 1319 1320 PMCDBG5(PRC,ATT,1, "detach pm=%p ri=%d proc=%p (%d, %s)", pm, 1321 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 1322 1323 if ((pm->pm_flags & PMC_F_DESCENDANTS) == 0) 1324 return (pmc_detach_one_process(p, pm, PMC_FLAG_REMOVE)); 1325 1326 /* 1327 * Traverse all children, detaching them from this PMC. We 1328 * ignore errors since we could be detaching a PMC from a 1329 * partially attached proc tree. 1330 */ 1331 sx_slock(&proctree_lock); 1332 1333 top = p; 1334 for (;;) { 1335 (void)pmc_detach_one_process(p, pm, PMC_FLAG_REMOVE); 1336 1337 if (!LIST_EMPTY(&p->p_children)) { 1338 p = LIST_FIRST(&p->p_children); 1339 } else { 1340 for (;;) { 1341 if (p == top) 1342 goto done; 1343 if (LIST_NEXT(p, p_sibling)) { 1344 p = LIST_NEXT(p, p_sibling); 1345 break; 1346 } 1347 p = p->p_pptr; 1348 } 1349 } 1350 } 1351 done: 1352 sx_sunlock(&proctree_lock); 1353 if (LIST_EMPTY(&pm->pm_targets)) 1354 pm->pm_flags &= ~PMC_F_ATTACH_DONE; 1355 1356 return (0); 1357 } 1358 1359 /* 1360 * Handle events after an exec() for a process: 1361 * - Inform log owners of the new exec() event 1362 * - Release any PMCs owned by the process before the exec() 1363 * - Detach PMCs from the target if required 1364 */ 1365 static void 1366 pmc_process_exec(struct thread *td, struct pmckern_procexec *pk) 1367 { 1368 struct pmc *pm; 1369 struct pmc_owner *po; 1370 struct pmc_process *pp; 1371 struct proc *p; 1372 char *fullpath, *freepath; 1373 u_int ri; 1374 bool is_using_hwpmcs; 1375 1376 sx_assert(&pmc_sx, SX_XLOCKED); 1377 1378 p = td->td_proc; 1379 pmc_getfilename(p->p_textvp, &fullpath, &freepath); 1380 1381 PMC_EPOCH_ENTER(); 1382 /* Inform owners of SS mode PMCs of the exec event. */ 1383 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) { 1384 if ((po->po_flags & PMC_PO_OWNS_LOGFILE) != 0) { 1385 pmclog_process_procexec(po, PMC_ID_INVALID, p->p_pid, 1386 pk->pm_baseaddr, pk->pm_dynaddr, fullpath); 1387 } 1388 } 1389 PMC_EPOCH_EXIT(); 1390 1391 PROC_LOCK(p); 1392 is_using_hwpmcs = (p->p_flag & P_HWPMC) != 0; 1393 PROC_UNLOCK(p); 1394 1395 if (!is_using_hwpmcs) { 1396 if (freepath != NULL) 1397 free(freepath, M_TEMP); 1398 return; 1399 } 1400 1401 /* 1402 * PMCs are not inherited across an exec(): remove any PMCs that this 1403 * process is the owner of. 1404 */ 1405 if ((po = pmc_find_owner_descriptor(p)) != NULL) { 1406 pmc_remove_owner(po); 1407 pmc_destroy_owner_descriptor(po); 1408 } 1409 1410 /* 1411 * If the process being exec'ed is not the target of any PMC, we are 1412 * done. 1413 */ 1414 if ((pp = pmc_find_process_descriptor(p, 0)) == NULL) { 1415 if (freepath != NULL) 1416 free(freepath, M_TEMP); 1417 return; 1418 } 1419 1420 /* 1421 * Log the exec event to all monitoring owners. Skip owners who have 1422 * already received the event because they had system sampling PMCs 1423 * active. 1424 */ 1425 for (ri = 0; ri < md->pmd_npmc; ri++) { 1426 if ((pm = pp->pp_pmcs[ri].pp_pmc) == NULL) 1427 continue; 1428 1429 po = pm->pm_owner; 1430 if (po->po_sscount == 0 && 1431 (po->po_flags & PMC_PO_OWNS_LOGFILE) != 0) { 1432 pmclog_process_procexec(po, pm->pm_id, p->p_pid, 1433 pk->pm_baseaddr, pk->pm_dynaddr, fullpath); 1434 } 1435 } 1436 1437 if (freepath != NULL) 1438 free(freepath, M_TEMP); 1439 1440 PMCDBG4(PRC,EXC,1, "exec proc=%p (%d, %s) cred-changed=%d", 1441 p, p->p_pid, p->p_comm, pk->pm_credentialschanged); 1442 1443 if (pk->pm_credentialschanged == 0) /* no change */ 1444 return; 1445 1446 /* 1447 * If the newly exec()'ed process has a different credential 1448 * than before, allow it to be the target of a PMC only if 1449 * the PMC's owner has sufficient privilege. 1450 */ 1451 for (ri = 0; ri < md->pmd_npmc; ri++) { 1452 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) { 1453 if (pmc_can_attach(pm, td->td_proc)) { 1454 pmc_detach_one_process(td->td_proc, pm, 1455 PMC_FLAG_NONE); 1456 } 1457 } 1458 } 1459 1460 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= md->pmd_npmc, 1461 ("[pmc,%d] Illegal ref count %u on pp %p", __LINE__, 1462 pp->pp_refcnt, pp)); 1463 1464 /* 1465 * If this process is no longer the target of any 1466 * PMCs, we can remove the process entry and free 1467 * up space. 1468 */ 1469 if (pp->pp_refcnt == 0) { 1470 pmc_remove_process_descriptor(pp); 1471 pmc_destroy_process_descriptor(pp); 1472 } 1473 } 1474 1475 /* 1476 * Thread context switch IN. 1477 */ 1478 static void 1479 pmc_process_csw_in(struct thread *td) 1480 { 1481 struct pmc *pm; 1482 struct pmc_classdep *pcd; 1483 struct pmc_cpu *pc; 1484 struct pmc_hw *phw __diagused; 1485 struct pmc_process *pp; 1486 struct pmc_thread *pt; 1487 struct proc *p; 1488 pmc_value_t newvalue; 1489 int cpu; 1490 u_int adjri, ri; 1491 1492 p = td->td_proc; 1493 pt = NULL; 1494 if ((pp = pmc_find_process_descriptor(p, PMC_FLAG_NONE)) == NULL) 1495 return; 1496 1497 KASSERT(pp->pp_proc == td->td_proc, 1498 ("[pmc,%d] not my thread state", __LINE__)); 1499 1500 critical_enter(); /* no preemption from this point */ 1501 1502 cpu = PCPU_GET(cpuid); /* td->td_oncpu is invalid */ 1503 1504 PMCDBG5(CSW,SWI,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p, 1505 p->p_pid, p->p_comm, pp); 1506 1507 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 1508 ("[pmc,%d] weird CPU id %d", __LINE__, cpu)); 1509 1510 pc = pmc_pcpu[cpu]; 1511 for (ri = 0; ri < md->pmd_npmc; ri++) { 1512 if ((pm = pp->pp_pmcs[ri].pp_pmc) == NULL) 1513 continue; 1514 1515 KASSERT(PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)), 1516 ("[pmc,%d] Target PMC in non-virtual mode (%d)", 1517 __LINE__, PMC_TO_MODE(pm))); 1518 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 1519 ("[pmc,%d] Row index mismatch pmc %d != ri %d", 1520 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 1521 1522 /* 1523 * Only PMCs that are marked as 'RUNNING' need 1524 * be placed on hardware. 1525 */ 1526 if (pm->pm_state != PMC_STATE_RUNNING) 1527 continue; 1528 1529 KASSERT(counter_u64_fetch(pm->pm_runcount) >= 0, 1530 ("[pmc,%d] pm=%p runcount %ju", __LINE__, pm, 1531 (uintmax_t)counter_u64_fetch(pm->pm_runcount))); 1532 1533 /* increment PMC runcount */ 1534 counter_u64_add(pm->pm_runcount, 1); 1535 1536 /* configure the HWPMC we are going to use. */ 1537 pcd = pmc_ri_to_classdep(md, ri, &adjri); 1538 (void)pcd->pcd_config_pmc(cpu, adjri, pm); 1539 1540 phw = pc->pc_hwpmcs[ri]; 1541 1542 KASSERT(phw != NULL, 1543 ("[pmc,%d] null hw pointer", __LINE__)); 1544 1545 KASSERT(phw->phw_pmc == pm, 1546 ("[pmc,%d] hw->pmc %p != pmc %p", __LINE__, 1547 phw->phw_pmc, pm)); 1548 1549 /* 1550 * Write out saved value and start the PMC. 1551 * 1552 * Sampling PMCs use a per-thread value, while 1553 * counting mode PMCs use a per-pmc value that is 1554 * inherited across descendants. 1555 */ 1556 if (PMC_TO_MODE(pm) == PMC_MODE_TS) { 1557 if (pt == NULL) 1558 pt = pmc_find_thread_descriptor(pp, td, 1559 PMC_FLAG_NONE); 1560 1561 KASSERT(pt != NULL, 1562 ("[pmc,%d] No thread found for td=%p", __LINE__, 1563 td)); 1564 1565 mtx_pool_lock_spin(pmc_mtxpool, pm); 1566 1567 /* 1568 * If we have a thread descriptor, use the per-thread 1569 * counter in the descriptor. If not, we will use 1570 * a per-process counter. 1571 * 1572 * TODO: Remove the per-process "safety net" once 1573 * we have thoroughly tested that we don't hit the 1574 * above assert. 1575 */ 1576 if (pt != NULL) { 1577 if (pt->pt_pmcs[ri].pt_pmcval > 0) 1578 newvalue = pt->pt_pmcs[ri].pt_pmcval; 1579 else 1580 newvalue = pm->pm_sc.pm_reloadcount; 1581 } else { 1582 /* 1583 * Use the saved value calculated after the most 1584 * recent time a thread using the shared counter 1585 * switched out. Reset the saved count in case 1586 * another thread from this process switches in 1587 * before any threads switch out. 1588 */ 1589 newvalue = pp->pp_pmcs[ri].pp_pmcval; 1590 pp->pp_pmcs[ri].pp_pmcval = 1591 pm->pm_sc.pm_reloadcount; 1592 } 1593 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1594 KASSERT(newvalue > 0 && newvalue <= 1595 pm->pm_sc.pm_reloadcount, 1596 ("[pmc,%d] pmcval outside of expected range cpu=%d " 1597 "ri=%d pmcval=%jx pm_reloadcount=%jx", __LINE__, 1598 cpu, ri, newvalue, pm->pm_sc.pm_reloadcount)); 1599 } else { 1600 KASSERT(PMC_TO_MODE(pm) == PMC_MODE_TC, 1601 ("[pmc,%d] illegal mode=%d", __LINE__, 1602 PMC_TO_MODE(pm))); 1603 mtx_pool_lock_spin(pmc_mtxpool, pm); 1604 newvalue = PMC_PCPU_SAVED(cpu, ri) = 1605 pm->pm_gv.pm_savedvalue; 1606 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1607 } 1608 1609 PMCDBG3(CSW,SWI,1,"cpu=%d ri=%d new=%jd", cpu, ri, newvalue); 1610 1611 (void)pcd->pcd_write_pmc(cpu, adjri, pm, newvalue); 1612 1613 /* If a sampling mode PMC, reset stalled state. */ 1614 if (PMC_TO_MODE(pm) == PMC_MODE_TS) 1615 pm->pm_pcpu_state[cpu].pps_stalled = 0; 1616 1617 /* Indicate that we desire this to run. */ 1618 pm->pm_pcpu_state[cpu].pps_cpustate = 1; 1619 1620 /* Start the PMC. */ 1621 (void)pcd->pcd_start_pmc(cpu, adjri, pm); 1622 } 1623 1624 /* 1625 * Perform any other architecture/cpu dependent thread 1626 * switch-in actions. 1627 */ 1628 (void)(*md->pmd_switch_in)(pc, pp); 1629 1630 critical_exit(); 1631 } 1632 1633 /* 1634 * Compute the change in a counter's value since it was last written. 1635 * The hardware counter is only pcd_width bits wide and wraps around, 1636 * while the value seeded into it may occupy the full 64-bit range, so 1637 * take the difference modulo the counter width. 1638 */ 1639 static pmc_value_t 1640 pmc_delta(const struct pmc_classdep *pcd, pmc_value_t newvalue, 1641 pmc_value_t oldvalue) 1642 { 1643 pmc_value_t delta; 1644 1645 delta = newvalue - oldvalue; 1646 if (pcd->pcd_width < 64) 1647 delta &= ((pmc_value_t)1 << pcd->pcd_width) - 1; 1648 return (delta); 1649 } 1650 1651 /* 1652 * Take a process-virtual PMC off the hardware of 'cpu' if it is 1653 * currently loaded there for process 'pp', accumulating its final 1654 * count and dropping its runcount reference. This is the same reclaim 1655 * that context switch out and process exit perform, factored out so it 1656 * can also run when a target is detached while the PMC may still be 1657 * live: the runcount reference is decremented by the switch-out reclaim 1658 * only, which the scheduler gates on P_HWPMC, so a detach that clears 1659 * P_HWPMC without draining would leak the reference and later wedge 1660 * pmc_wait_for_pmc_idle(). Must be called in a critical section. 1661 */ 1662 static void 1663 pmc_reclaim_pmc_from_cpu(struct pmc *pm, struct pmc_process *pp, int cpu) 1664 { 1665 struct pmc_classdep *pcd; 1666 struct pmc *phw_pm; 1667 pmc_value_t newvalue, tmp; 1668 u_int adjri, ri; 1669 1670 ri = PMC_TO_ROWINDEX(pm); 1671 pcd = pmc_ri_to_classdep(md, ri, &adjri); 1672 1673 /* Only reclaim if this PMC is actually loaded on this CPU. */ 1674 phw_pm = NULL; 1675 (void)(*pcd->pcd_get_config)(cpu, adjri, &phw_pm); 1676 if (phw_pm != pm) 1677 return; 1678 1679 KASSERT(counter_u64_fetch(pm->pm_runcount) > 0, 1680 ("[pmc,%d] pm=%p runcount %ju", __LINE__, pm, 1681 (uintmax_t)counter_u64_fetch(pm->pm_runcount))); 1682 1683 if (pm->pm_pcpu_state[cpu].pps_cpustate) { 1684 pm->pm_pcpu_state[cpu].pps_cpustate = 0; 1685 if (pm->pm_pcpu_state[cpu].pps_stalled == 0) { 1686 (void)pcd->pcd_stop_pmc(cpu, adjri, pm); 1687 1688 if (PMC_TO_MODE(pm) == PMC_MODE_TC) { 1689 (void)pcd->pcd_read_pmc(cpu, adjri, pm, 1690 &newvalue); 1691 tmp = pmc_delta(pcd, newvalue, 1692 PMC_PCPU_SAVED(cpu, ri)); 1693 1694 mtx_pool_lock_spin(pmc_mtxpool, pm); 1695 pm->pm_gv.pm_savedvalue += tmp; 1696 pp->pp_pmcs[ri].pp_pmcval += tmp; 1697 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1698 } 1699 } 1700 } 1701 1702 counter_u64_add(pm->pm_runcount, -1); 1703 (void)pcd->pcd_config_pmc(cpu, adjri, NULL); 1704 } 1705 1706 /* 1707 * Thread context switch OUT. 1708 */ 1709 static void 1710 pmc_process_csw_out(struct thread *td) 1711 { 1712 struct pmc *pm; 1713 struct pmc_classdep *pcd; 1714 struct pmc_cpu *pc; 1715 struct pmc_process *pp; 1716 struct pmc_thread *pt = NULL; 1717 struct proc *p; 1718 pmc_value_t newvalue, tmp; 1719 enum pmc_mode mode; 1720 int cpu; 1721 u_int adjri, ri; 1722 1723 /* 1724 * Locate our process descriptor; this may be NULL if 1725 * this process is exiting and we have already removed 1726 * the process from the target process table. 1727 * 1728 * Note that due to kernel preemption, multiple 1729 * context switches may happen while the process is 1730 * exiting. 1731 * 1732 * Note also that if the target process cannot be 1733 * found we still need to deconfigure any PMCs that 1734 * are currently running on hardware. 1735 */ 1736 p = td->td_proc; 1737 pp = pmc_find_process_descriptor(p, PMC_FLAG_NONE); 1738 1739 critical_enter(); 1740 1741 cpu = PCPU_GET(cpuid); /* td->td_oncpu is invalid */ 1742 1743 PMCDBG5(CSW,SWO,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p, 1744 p->p_pid, p->p_comm, pp); 1745 1746 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 1747 ("[pmc,%d weird CPU id %d", __LINE__, cpu)); 1748 1749 pc = pmc_pcpu[cpu]; 1750 1751 /* 1752 * When a PMC gets unlinked from a target PMC, it will 1753 * be removed from the target's pp_pmc[] array. 1754 * 1755 * However, on a MP system, the target could have been 1756 * executing on another CPU at the time of the unlink. 1757 * So, at context switch OUT time, we need to look at 1758 * the hardware to determine if a PMC is scheduled on 1759 * it. 1760 */ 1761 for (ri = 0; ri < md->pmd_npmc; ri++) { 1762 pcd = pmc_ri_to_classdep(md, ri, &adjri); 1763 pm = NULL; 1764 (void)(*pcd->pcd_get_config)(cpu, adjri, &pm); 1765 1766 if (pm == NULL) /* nothing at this row index */ 1767 continue; 1768 1769 mode = PMC_TO_MODE(pm); 1770 if (!PMC_IS_VIRTUAL_MODE(mode)) 1771 continue; /* not a process virtual PMC */ 1772 1773 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 1774 ("[pmc,%d] ri mismatch pmc(%d) ri(%d)", 1775 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 1776 1777 /* 1778 * Change desired state, and then stop if not stalled. 1779 * This two-step dance should avoid race conditions where 1780 * an interrupt re-enables the PMC after this code has 1781 * already checked the pm_stalled flag. 1782 */ 1783 pm->pm_pcpu_state[cpu].pps_cpustate = 0; 1784 if (pm->pm_pcpu_state[cpu].pps_stalled == 0) 1785 (void)pcd->pcd_stop_pmc(cpu, adjri, pm); 1786 1787 KASSERT(counter_u64_fetch(pm->pm_runcount) > 0, 1788 ("[pmc,%d] pm=%p runcount %ju", __LINE__, pm, 1789 (uintmax_t)counter_u64_fetch(pm->pm_runcount))); 1790 1791 /* reduce this PMC's runcount */ 1792 counter_u64_add(pm->pm_runcount, -1); 1793 1794 /* 1795 * If this PMC is associated with this process, 1796 * save the reading. 1797 */ 1798 if (pm->pm_state != PMC_STATE_DELETED && pp != NULL && 1799 pp->pp_pmcs[ri].pp_pmc != NULL) { 1800 KASSERT(pm == pp->pp_pmcs[ri].pp_pmc, 1801 ("[pmc,%d] pm %p != pp_pmcs[%d] %p", __LINE__, 1802 pm, ri, pp->pp_pmcs[ri].pp_pmc)); 1803 KASSERT(pp->pp_refcnt > 0, 1804 ("[pmc,%d] pp refcnt = %d", __LINE__, 1805 pp->pp_refcnt)); 1806 1807 (void)pcd->pcd_read_pmc(cpu, adjri, pm, &newvalue); 1808 1809 if (mode == PMC_MODE_TS) { 1810 PMCDBG3(CSW,SWO,1,"cpu=%d ri=%d val=%jd (samp)", 1811 cpu, ri, newvalue); 1812 1813 if (pt == NULL) 1814 pt = pmc_find_thread_descriptor(pp, td, 1815 PMC_FLAG_NONE); 1816 1817 KASSERT(pt != NULL, 1818 ("[pmc,%d] No thread found for td=%p", 1819 __LINE__, td)); 1820 1821 mtx_pool_lock_spin(pmc_mtxpool, pm); 1822 1823 /* 1824 * If we have a thread descriptor, save the 1825 * per-thread counter in the descriptor. If not, 1826 * we will update the per-process counter. 1827 * 1828 * TODO: Remove the per-process "safety net" 1829 * once we have thoroughly tested that we 1830 * don't hit the above assert. 1831 */ 1832 if (pt != NULL) { 1833 pt->pt_pmcs[ri].pt_pmcval = newvalue; 1834 } else { 1835 /* 1836 * For sampling process-virtual PMCs, 1837 * newvalue is the number of events to 1838 * be seen until the next sampling 1839 * interrupt. We can just add the events 1840 * left from this invocation to the 1841 * counter, then adjust in case we 1842 * overflow our range. 1843 * 1844 * (Recall that we reload the counter 1845 * every time we use it.) 1846 */ 1847 pp->pp_pmcs[ri].pp_pmcval += newvalue; 1848 if (pp->pp_pmcs[ri].pp_pmcval > 1849 pm->pm_sc.pm_reloadcount) { 1850 pp->pp_pmcs[ri].pp_pmcval -= 1851 pm->pm_sc.pm_reloadcount; 1852 } 1853 } 1854 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1855 } else { 1856 /* 1857 * For counting process-virtual PMCs, the 1858 * hardware counter's value increases 1859 * monotonically modulo the counter width; 1860 * pmc_delta() recovers the increment even 1861 * when the counter wrapped during the run. 1862 */ 1863 tmp = pmc_delta(pcd, newvalue, 1864 PMC_PCPU_SAVED(cpu, ri)); 1865 1866 PMCDBG3(CSW,SWO,1,"cpu=%d ri=%d tmp=%jd (count)", 1867 cpu, ri, tmp); 1868 1869 mtx_pool_lock_spin(pmc_mtxpool, pm); 1870 pm->pm_gv.pm_savedvalue += tmp; 1871 pp->pp_pmcs[ri].pp_pmcval += tmp; 1872 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1873 1874 if (pm->pm_flags & PMC_F_LOG_PROCCSW) 1875 pmclog_process_proccsw(pm, pp, tmp, td); 1876 } 1877 } 1878 1879 /* Mark hardware as free. */ 1880 (void)pcd->pcd_config_pmc(cpu, adjri, NULL); 1881 } 1882 1883 /* 1884 * Perform any other architecture/cpu dependent thread 1885 * switch out functions. 1886 */ 1887 (void)(*md->pmd_switch_out)(pc, pp); 1888 1889 critical_exit(); 1890 } 1891 1892 /* 1893 * A new thread for a process. 1894 */ 1895 static void 1896 pmc_process_thread_add(struct thread *td) 1897 { 1898 struct pmc_process *pmc; 1899 1900 pmc = pmc_find_process_descriptor(td->td_proc, PMC_FLAG_NONE); 1901 if (pmc != NULL) 1902 pmc_find_thread_descriptor(pmc, td, PMC_FLAG_ALLOCATE); 1903 } 1904 1905 /* 1906 * A thread delete for a process. 1907 */ 1908 static void 1909 pmc_process_thread_delete(struct thread *td) 1910 { 1911 struct pmc_process *pmc; 1912 1913 pmc = pmc_find_process_descriptor(td->td_proc, PMC_FLAG_NONE); 1914 if (pmc != NULL) 1915 pmc_thread_descriptor_pool_free(pmc_find_thread_descriptor(pmc, 1916 td, PMC_FLAG_REMOVE)); 1917 } 1918 1919 /* 1920 * A userret() call for a thread. 1921 */ 1922 static void 1923 pmc_process_thread_userret(struct thread *td) 1924 { 1925 sched_pin(); 1926 pmc_capture_user_callchain(curcpu, PMC_UR, td->td_frame); 1927 sched_unpin(); 1928 } 1929 1930 /* 1931 * A mapping change for a process. 1932 */ 1933 static void 1934 pmc_process_mmap(struct thread *td, struct pmckern_map_in *pkm) 1935 { 1936 const struct pmc *pm; 1937 const struct pmc_process *pp; 1938 struct pmc_owner *po; 1939 char *fullpath, *freepath; 1940 pid_t pid; 1941 int ri; 1942 1943 MPASS(!in_epoch(global_epoch_preempt)); 1944 1945 freepath = fullpath = NULL; 1946 pmc_getfilename((struct vnode *)pkm->pm_file, &fullpath, &freepath); 1947 1948 pid = td->td_proc->p_pid; 1949 1950 PMC_EPOCH_ENTER(); 1951 /* Inform owners of all system-wide sampling PMCs. */ 1952 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) { 1953 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1954 pmclog_process_map_in(po, pid, pkm->pm_address, 1955 fullpath); 1956 } 1957 1958 if ((pp = pmc_find_process_descriptor(td->td_proc, 0)) == NULL) 1959 goto done; 1960 1961 /* 1962 * Inform sampling PMC owners tracking this process. 1963 */ 1964 for (ri = 0; ri < md->pmd_npmc; ri++) { 1965 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL && 1966 PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) { 1967 pmclog_process_map_in(pm->pm_owner, 1968 pid, pkm->pm_address, fullpath); 1969 } 1970 } 1971 1972 done: 1973 if (freepath != NULL) 1974 free(freepath, M_TEMP); 1975 PMC_EPOCH_EXIT(); 1976 } 1977 1978 /* 1979 * Log an munmap request. 1980 */ 1981 static void 1982 pmc_process_munmap(struct thread *td, struct pmckern_map_out *pkm) 1983 { 1984 const struct pmc *pm; 1985 const struct pmc_process *pp; 1986 struct pmc_owner *po; 1987 pid_t pid; 1988 int ri; 1989 1990 pid = td->td_proc->p_pid; 1991 1992 PMC_EPOCH_ENTER(); 1993 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) { 1994 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1995 pmclog_process_map_out(po, pid, pkm->pm_address, 1996 pkm->pm_address + pkm->pm_size); 1997 } 1998 PMC_EPOCH_EXIT(); 1999 2000 if ((pp = pmc_find_process_descriptor(td->td_proc, 0)) == NULL) 2001 return; 2002 2003 for (ri = 0; ri < md->pmd_npmc; ri++) { 2004 pm = pp->pp_pmcs[ri].pp_pmc; 2005 if (pm != NULL && PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) { 2006 pmclog_process_map_out(pm->pm_owner, pid, 2007 pkm->pm_address, pkm->pm_address + pkm->pm_size); 2008 } 2009 } 2010 } 2011 2012 /* 2013 * Log mapping information about the kernel. 2014 */ 2015 static void 2016 pmc_log_kernel_mappings(struct pmc *pm) 2017 { 2018 struct pmc_owner *po; 2019 struct pmckern_map_in *km, *kmbase; 2020 2021 MPASS(in_epoch(global_epoch_preempt) || sx_xlocked(&pmc_sx)); 2022 KASSERT(PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)), 2023 ("[pmc,%d] non-sampling PMC (%p) desires mapping information", 2024 __LINE__, (void *) pm)); 2025 2026 po = pm->pm_owner; 2027 if ((po->po_flags & PMC_PO_INITIAL_MAPPINGS_DONE) != 0) 2028 return; 2029 2030 if (PMC_TO_MODE(pm) == PMC_MODE_SS) 2031 pmc_process_allproc(pm); 2032 2033 /* 2034 * Log the current set of kernel modules. 2035 */ 2036 kmbase = linker_hwpmc_list_objects(); 2037 for (km = kmbase; km->pm_file != NULL; km++) { 2038 PMCDBG2(LOG,REG,1,"%s %p", (char *)km->pm_file, 2039 (void *)km->pm_address); 2040 pmclog_process_map_in(po, (pid_t)-1, km->pm_address, 2041 km->pm_file); 2042 } 2043 free(kmbase, M_LINKER); 2044 2045 po->po_flags |= PMC_PO_INITIAL_MAPPINGS_DONE; 2046 } 2047 2048 /* 2049 * Log the mappings for a single process. 2050 */ 2051 static void 2052 pmc_log_process_mappings(struct pmc_owner *po, struct proc *p) 2053 { 2054 vm_map_t map; 2055 vm_map_entry_t entry; 2056 vm_object_t obj, lobj, tobj; 2057 vm_offset_t last_end; 2058 vm_offset_t start_addr; 2059 struct vnode *vp, *last_vp; 2060 struct vmspace *vm; 2061 char *fullpath, *freepath; 2062 u_int last_timestamp; 2063 2064 last_vp = NULL; 2065 last_end = (vm_offset_t)0; 2066 fullpath = freepath = NULL; 2067 2068 if ((vm = vmspace_acquire_ref(p)) == NULL) 2069 return; 2070 2071 map = &vm->vm_map; 2072 vm_map_lock_read(map); 2073 VM_MAP_ENTRY_FOREACH(entry, map) { 2074 if (entry == NULL) { 2075 PMCDBG2(LOG,OPS,2, "hwpmc: vm_map entry unexpectedly " 2076 "NULL! pid=%d vm_map=%p\n", p->p_pid, map); 2077 break; 2078 } 2079 2080 /* 2081 * We only care about executable map entries. 2082 */ 2083 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0 || 2084 (entry->protection & VM_PROT_EXECUTE) == 0 || 2085 entry->object.vm_object == NULL) { 2086 continue; 2087 } 2088 2089 obj = entry->object.vm_object; 2090 VM_OBJECT_RLOCK(obj); 2091 2092 /* 2093 * Walk the backing_object list to find the base (non-shadowed) 2094 * vm_object. 2095 */ 2096 for (lobj = tobj = obj; tobj != NULL; 2097 tobj = tobj->backing_object) { 2098 if (tobj != obj) 2099 VM_OBJECT_RLOCK(tobj); 2100 if (lobj != obj) 2101 VM_OBJECT_RUNLOCK(lobj); 2102 lobj = tobj; 2103 } 2104 2105 /* 2106 * At this point lobj is the base vm_object and it is locked. 2107 */ 2108 if (lobj == NULL) { 2109 PMCDBG3(LOG,OPS,2, 2110 "hwpmc: lobj unexpectedly NULL! pid=%d " 2111 "vm_map=%p vm_obj=%p\n", p->p_pid, map, obj); 2112 VM_OBJECT_RUNLOCK(obj); 2113 continue; 2114 } 2115 2116 vp = vm_object_vnode(lobj); 2117 if (vp == NULL) { 2118 if (lobj != obj) 2119 VM_OBJECT_RUNLOCK(lobj); 2120 VM_OBJECT_RUNLOCK(obj); 2121 continue; 2122 } 2123 2124 /* 2125 * Skip contiguous regions that point to the same vnode, so we 2126 * don't emit redundant MAP-IN directives. 2127 */ 2128 if (entry->start == last_end && vp == last_vp) { 2129 last_end = entry->end; 2130 if (lobj != obj) 2131 VM_OBJECT_RUNLOCK(lobj); 2132 VM_OBJECT_RUNLOCK(obj); 2133 continue; 2134 } 2135 2136 /* 2137 * We don't want to keep the proc's vm_map or this vm_object 2138 * locked while we walk the pathname, since vn_fullpath() can 2139 * sleep. However, if we drop the lock, it's possible for 2140 * concurrent activity to modify the vm_map list. To protect 2141 * against this, we save the vm_map timestamp before we release 2142 * the lock, and check it after we reacquire the lock below. 2143 */ 2144 start_addr = entry->start; 2145 last_end = entry->end; 2146 last_timestamp = map->timestamp; 2147 vm_map_unlock_read(map); 2148 2149 vref(vp); 2150 if (lobj != obj) 2151 VM_OBJECT_RUNLOCK(lobj); 2152 VM_OBJECT_RUNLOCK(obj); 2153 2154 freepath = NULL; 2155 pmc_getfilename(vp, &fullpath, &freepath); 2156 last_vp = vp; 2157 2158 vrele(vp); 2159 2160 vp = NULL; 2161 pmclog_process_map_in(po, p->p_pid, start_addr, fullpath); 2162 if (freepath != NULL) 2163 free(freepath, M_TEMP); 2164 2165 vm_map_lock_read(map); 2166 2167 /* 2168 * If our saved timestamp doesn't match, this means 2169 * that the vm_map was modified out from under us and 2170 * we can't trust our current "entry" pointer. Do a 2171 * new lookup for this entry. If there is no entry 2172 * for this address range, vm_map_lookup_entry() will 2173 * return the previous one, so we always want to go to 2174 * the next entry on the next loop iteration. 2175 * 2176 * There is an edge condition here that can occur if 2177 * there is no entry at or before this address. In 2178 * this situation, vm_map_lookup_entry returns 2179 * &map->header, which would cause our loop to abort 2180 * without processing the rest of the map. However, 2181 * in practice this will never happen for process 2182 * vm_map. This is because the executable's text 2183 * segment is the first mapping in the proc's address 2184 * space, and this mapping is never removed until the 2185 * process exits, so there will always be a non-header 2186 * entry at or before the requested address for 2187 * vm_map_lookup_entry to return. 2188 */ 2189 if (map->timestamp != last_timestamp) 2190 vm_map_lookup_entry(map, last_end - 1, &entry); 2191 } 2192 2193 vm_map_unlock_read(map); 2194 vmspace_free(vm); 2195 return; 2196 } 2197 2198 /* 2199 * Log mappings for all processes in the system. 2200 */ 2201 static void 2202 pmc_log_all_process_mappings(struct pmc_owner *po) 2203 { 2204 struct proc *p, *top; 2205 2206 sx_assert(&pmc_sx, SX_XLOCKED); 2207 2208 if ((p = pfind(1)) == NULL) 2209 panic("[pmc,%d] Cannot find init", __LINE__); 2210 2211 PROC_UNLOCK(p); 2212 2213 sx_slock(&proctree_lock); 2214 2215 top = p; 2216 for (;;) { 2217 pmc_log_process_mappings(po, p); 2218 if (!LIST_EMPTY(&p->p_children)) 2219 p = LIST_FIRST(&p->p_children); 2220 else for (;;) { 2221 if (p == top) 2222 goto done; 2223 if (LIST_NEXT(p, p_sibling)) { 2224 p = LIST_NEXT(p, p_sibling); 2225 break; 2226 } 2227 p = p->p_pptr; 2228 } 2229 } 2230 done: 2231 sx_sunlock(&proctree_lock); 2232 } 2233 2234 #ifdef HWPMC_DEBUG 2235 const char *pmc_hooknames[] = { 2236 /* these strings correspond to PMC_FN_* in <sys/pmckern.h> */ 2237 "", 2238 "EXEC", 2239 "CSW-IN", 2240 "CSW-OUT", 2241 "SAMPLE", 2242 "UNUSED1", 2243 "UNUSED2", 2244 "MMAP", 2245 "MUNMAP", 2246 "CALLCHAIN-NMI", 2247 "CALLCHAIN-SOFT", 2248 "SOFTSAMPLING", 2249 "THR-CREATE", 2250 "THR-EXIT", 2251 "THR-USERRET", 2252 "THR-CREATE-LOG", 2253 "THR-EXIT-LOG", 2254 "PROC-CREATE-LOG" 2255 }; 2256 #endif 2257 2258 /* 2259 * The 'hook' invoked from the kernel proper 2260 */ 2261 static int 2262 pmc_hook_handler(struct thread *td, int function, void *arg) 2263 { 2264 int cpu; 2265 2266 PMCDBG4(MOD,PMH,1, "hook td=%p func=%d \"%s\" arg=%p", td, function, 2267 pmc_hooknames[function], arg); 2268 2269 switch (function) { 2270 case PMC_FN_PROCESS_EXEC: 2271 pmc_process_exec(td, (struct pmckern_procexec *)arg); 2272 break; 2273 2274 case PMC_FN_CSW_IN: 2275 pmc_process_csw_in(td); 2276 break; 2277 2278 case PMC_FN_CSW_OUT: 2279 pmc_process_csw_out(td); 2280 break; 2281 2282 /* 2283 * Process accumulated PC samples. 2284 * 2285 * This function is expected to be called by hardclock() for 2286 * each CPU that has accumulated PC samples. 2287 * 2288 * This function is to be executed on the CPU whose samples 2289 * are being processed. 2290 */ 2291 case PMC_FN_DO_SAMPLES: 2292 /* 2293 * Clear the cpu specific bit in the CPU mask before 2294 * do the rest of the processing. If the NMI handler 2295 * gets invoked after the "atomic_clear_int()" call 2296 * below but before "pmc_process_samples()" gets 2297 * around to processing the interrupt, then we will 2298 * come back here at the next hardclock() tick (and 2299 * may find nothing to do if "pmc_process_samples()" 2300 * had already processed the interrupt). We don't 2301 * lose the interrupt sample. 2302 */ 2303 DPCPU_SET(pmc_sampled, 0); 2304 cpu = PCPU_GET(cpuid); 2305 pmc_process_samples(cpu, PMC_HR); 2306 pmc_process_samples(cpu, PMC_SR); 2307 pmc_process_samples(cpu, PMC_UR); 2308 break; 2309 2310 case PMC_FN_MMAP: 2311 pmc_process_mmap(td, (struct pmckern_map_in *)arg); 2312 break; 2313 2314 case PMC_FN_MUNMAP: 2315 MPASS(in_epoch(global_epoch_preempt) || sx_xlocked(&pmc_sx)); 2316 pmc_process_munmap(td, (struct pmckern_map_out *)arg); 2317 break; 2318 2319 case PMC_FN_PROC_CREATE_LOG: 2320 pmc_process_proccreate((struct proc *)arg); 2321 break; 2322 2323 case PMC_FN_USER_CALLCHAIN: 2324 /* 2325 * Record a call chain. 2326 */ 2327 KASSERT(td == curthread, ("[pmc,%d] td != curthread", 2328 __LINE__)); 2329 2330 pmc_capture_user_callchain(PCPU_GET(cpuid), PMC_HR, 2331 (struct trapframe *)arg); 2332 2333 KASSERT(td->td_pinned == 1, 2334 ("[pmc,%d] invalid td_pinned value", __LINE__)); 2335 sched_unpin(); /* Can migrate safely now. */ 2336 2337 td->td_pflags &= ~TDP_CALLCHAIN; 2338 break; 2339 2340 case PMC_FN_USER_CALLCHAIN_SOFT: 2341 /* 2342 * Record a call chain. 2343 */ 2344 KASSERT(td == curthread, ("[pmc,%d] td != curthread", 2345 __LINE__)); 2346 2347 cpu = PCPU_GET(cpuid); 2348 pmc_capture_user_callchain(cpu, PMC_SR, 2349 (struct trapframe *) arg); 2350 2351 KASSERT(td->td_pinned == 1, 2352 ("[pmc,%d] invalid td_pinned value", __LINE__)); 2353 2354 sched_unpin(); /* Can migrate safely now. */ 2355 2356 td->td_pflags &= ~TDP_CALLCHAIN; 2357 break; 2358 2359 case PMC_FN_SOFT_SAMPLING: 2360 /* 2361 * Call soft PMC sampling intr. 2362 */ 2363 pmc_soft_intr((struct pmckern_soft *)arg); 2364 break; 2365 2366 case PMC_FN_THR_CREATE: 2367 pmc_process_thread_add(td); 2368 pmc_process_threadcreate(td); 2369 break; 2370 2371 case PMC_FN_THR_CREATE_LOG: 2372 pmc_process_threadcreate(td); 2373 break; 2374 2375 case PMC_FN_THR_EXIT: 2376 KASSERT(td == curthread, ("[pmc,%d] td != curthread", 2377 __LINE__)); 2378 pmc_process_thread_delete(td); 2379 pmc_process_threadexit(td); 2380 break; 2381 case PMC_FN_THR_EXIT_LOG: 2382 pmc_process_threadexit(td); 2383 break; 2384 case PMC_FN_THR_USERRET: 2385 KASSERT(td == curthread, ("[pmc,%d] td != curthread", 2386 __LINE__)); 2387 pmc_process_thread_userret(td); 2388 break; 2389 default: 2390 #ifdef HWPMC_DEBUG 2391 KASSERT(0, ("[pmc,%d] unknown hook %d\n", __LINE__, function)); 2392 #endif 2393 break; 2394 } 2395 2396 return (0); 2397 } 2398 2399 /* 2400 * Allocate a 'struct pmc_owner' descriptor in the owner hash table. 2401 */ 2402 static struct pmc_owner * 2403 pmc_allocate_owner_descriptor(struct proc *p) 2404 { 2405 struct pmc_owner *po; 2406 struct pmc_ownerhash *poh; 2407 uint32_t hindex; 2408 2409 hindex = PMC_HASH_PTR(p, pmc_ownerhashmask); 2410 poh = &pmc_ownerhash[hindex]; 2411 2412 /* Allocate space for N pointers and one descriptor struct. */ 2413 po = malloc(sizeof(struct pmc_owner), M_PMC, M_WAITOK | M_ZERO); 2414 po->po_owner = p; 2415 LIST_INSERT_HEAD(poh, po, po_next); /* insert into hash table */ 2416 2417 TAILQ_INIT(&po->po_logbuffers); 2418 mtx_init(&po->po_mtx, "pmc-owner-mtx", "pmc-per-proc", MTX_SPIN); 2419 2420 PMCDBG4(OWN,ALL,1, "allocate-owner proc=%p (%d, %s) pmc-owner=%p", 2421 p, p->p_pid, p->p_comm, po); 2422 2423 return (po); 2424 } 2425 2426 static void 2427 pmc_destroy_owner_descriptor(struct pmc_owner *po) 2428 { 2429 2430 PMCDBG4(OWN,REL,1, "destroy-owner po=%p proc=%p (%d, %s)", 2431 po, po->po_owner, po->po_owner->p_pid, po->po_owner->p_comm); 2432 2433 mtx_destroy(&po->po_mtx); 2434 free(po, M_PMC); 2435 } 2436 2437 /* 2438 * Allocate a thread descriptor from the free pool. 2439 * 2440 * NOTE: This *can* return NULL. 2441 */ 2442 static struct pmc_thread * 2443 pmc_thread_descriptor_pool_alloc(void) 2444 { 2445 struct pmc_thread *pt; 2446 2447 mtx_lock_spin(&pmc_threadfreelist_mtx); 2448 if ((pt = LIST_FIRST(&pmc_threadfreelist)) != NULL) { 2449 LIST_REMOVE(pt, pt_next); 2450 pmc_threadfreelist_entries--; 2451 } 2452 mtx_unlock_spin(&pmc_threadfreelist_mtx); 2453 2454 return (pt); 2455 } 2456 2457 /* 2458 * Add a thread descriptor to the free pool. We use this instead of free() 2459 * to maintain a cache of free entries. Additionally, we can safely call 2460 * this function when we cannot call free(), such as in a critical section. 2461 */ 2462 static void 2463 pmc_thread_descriptor_pool_free(struct pmc_thread *pt) 2464 { 2465 2466 if (pt == NULL) 2467 return; 2468 2469 memset(pt, 0, THREADENTRY_SIZE); 2470 mtx_lock_spin(&pmc_threadfreelist_mtx); 2471 LIST_INSERT_HEAD(&pmc_threadfreelist, pt, pt_next); 2472 pmc_threadfreelist_entries++; 2473 if (pmc_threadfreelist_entries > pmc_threadfreelist_max) 2474 taskqueue_enqueue(taskqueue_fast, &free_task); 2475 mtx_unlock_spin(&pmc_threadfreelist_mtx); 2476 } 2477 2478 /* 2479 * An asynchronous task to manage the free list. 2480 */ 2481 static void 2482 pmc_thread_descriptor_pool_free_task(void *arg __unused, int pending __unused) 2483 { 2484 struct pmc_thread *pt; 2485 LIST_HEAD(, pmc_thread) tmplist; 2486 int delta; 2487 2488 LIST_INIT(&tmplist); 2489 2490 /* Determine what changes, if any, we need to make. */ 2491 mtx_lock_spin(&pmc_threadfreelist_mtx); 2492 delta = pmc_threadfreelist_entries - pmc_threadfreelist_max; 2493 while (delta > 0 && (pt = LIST_FIRST(&pmc_threadfreelist)) != NULL) { 2494 delta--; 2495 pmc_threadfreelist_entries--; 2496 LIST_REMOVE(pt, pt_next); 2497 LIST_INSERT_HEAD(&tmplist, pt, pt_next); 2498 } 2499 mtx_unlock_spin(&pmc_threadfreelist_mtx); 2500 2501 /* If there are entries to free, free them. */ 2502 while (!LIST_EMPTY(&tmplist)) { 2503 pt = LIST_FIRST(&tmplist); 2504 LIST_REMOVE(pt, pt_next); 2505 free(pt, M_PMC); 2506 } 2507 } 2508 2509 /* 2510 * Drain the thread free pool, freeing all allocations. 2511 */ 2512 static void 2513 pmc_thread_descriptor_pool_drain(void) 2514 { 2515 struct pmc_thread *pt, *next; 2516 2517 LIST_FOREACH_SAFE(pt, &pmc_threadfreelist, pt_next, next) { 2518 LIST_REMOVE(pt, pt_next); 2519 free(pt, M_PMC); 2520 } 2521 } 2522 2523 /* 2524 * find the descriptor corresponding to thread 'td', adding or removing it 2525 * as specified by 'mode'. 2526 * 2527 * Note that this supports additional mode flags in addition to those 2528 * supported by pmc_find_process_descriptor(): 2529 * PMC_FLAG_NOWAIT: Causes the function to not wait for mallocs. 2530 * This makes it safe to call while holding certain other locks. 2531 */ 2532 static struct pmc_thread * 2533 pmc_find_thread_descriptor(struct pmc_process *pp, struct thread *td, 2534 uint32_t mode) 2535 { 2536 struct pmc_thread *pt = NULL, *ptnew = NULL; 2537 int wait_flag; 2538 2539 KASSERT(td != NULL, ("[pmc,%d] called to add NULL td", __LINE__)); 2540 2541 /* 2542 * Pre-allocate memory in the PMC_FLAG_ALLOCATE case prior to 2543 * acquiring the lock. 2544 */ 2545 if ((mode & PMC_FLAG_ALLOCATE) != 0) { 2546 if ((ptnew = pmc_thread_descriptor_pool_alloc()) == NULL) { 2547 wait_flag = M_WAITOK; 2548 if ((mode & PMC_FLAG_NOWAIT) != 0 || 2549 in_epoch(global_epoch_preempt)) 2550 wait_flag = M_NOWAIT; 2551 2552 ptnew = malloc(THREADENTRY_SIZE, M_PMC, 2553 wait_flag | M_ZERO); 2554 } 2555 } 2556 2557 mtx_lock_spin(pp->pp_tdslock); 2558 LIST_FOREACH(pt, &pp->pp_tds, pt_next) { 2559 if (pt->pt_td == td) 2560 break; 2561 } 2562 2563 if ((mode & PMC_FLAG_REMOVE) != 0 && pt != NULL) 2564 LIST_REMOVE(pt, pt_next); 2565 2566 if ((mode & PMC_FLAG_ALLOCATE) != 0 && pt == NULL && ptnew != NULL) { 2567 pt = ptnew; 2568 ptnew = NULL; 2569 pt->pt_td = td; 2570 LIST_INSERT_HEAD(&pp->pp_tds, pt, pt_next); 2571 } 2572 2573 mtx_unlock_spin(pp->pp_tdslock); 2574 2575 if (ptnew != NULL) { 2576 free(ptnew, M_PMC); 2577 } 2578 2579 return (pt); 2580 } 2581 2582 /* 2583 * Try to add thread descriptors for each thread in a process. 2584 */ 2585 static void 2586 pmc_add_thread_descriptors_from_proc(struct proc *p, struct pmc_process *pp) 2587 { 2588 struct pmc_thread **tdlist; 2589 struct thread *curtd; 2590 int i, tdcnt, tdlistsz; 2591 2592 KASSERT(!PROC_LOCKED(p), ("[pmc,%d] proc unexpectedly locked", 2593 __LINE__)); 2594 tdcnt = 32; 2595 restart: 2596 tdlistsz = roundup2(tdcnt, 32); 2597 2598 tdcnt = 0; 2599 tdlist = malloc(sizeof(struct pmc_thread *) * tdlistsz, M_TEMP, 2600 M_WAITOK); 2601 2602 PROC_LOCK(p); 2603 FOREACH_THREAD_IN_PROC(p, curtd) 2604 tdcnt++; 2605 if (tdcnt >= tdlistsz) { 2606 PROC_UNLOCK(p); 2607 free(tdlist, M_TEMP); 2608 goto restart; 2609 } 2610 2611 /* 2612 * Try to add each thread to the list without sleeping. If unable, 2613 * add to a queue to retry after dropping the process lock. 2614 */ 2615 tdcnt = 0; 2616 FOREACH_THREAD_IN_PROC(p, curtd) { 2617 tdlist[tdcnt] = pmc_find_thread_descriptor(pp, curtd, 2618 PMC_FLAG_ALLOCATE | PMC_FLAG_NOWAIT); 2619 if (tdlist[tdcnt] == NULL) { 2620 PROC_UNLOCK(p); 2621 for (i = 0; i <= tdcnt; i++) 2622 pmc_thread_descriptor_pool_free(tdlist[i]); 2623 free(tdlist, M_TEMP); 2624 goto restart; 2625 } 2626 tdcnt++; 2627 } 2628 PROC_UNLOCK(p); 2629 free(tdlist, M_TEMP); 2630 } 2631 2632 /* 2633 * Find the descriptor corresponding to process 'p', adding or removing it 2634 * as specified by 'mode'. 2635 */ 2636 static struct pmc_process * 2637 pmc_find_process_descriptor(struct proc *p, uint32_t mode) 2638 { 2639 struct pmc_process *pp, *ppnew; 2640 struct pmc_processhash *pph; 2641 uint32_t hindex; 2642 2643 hindex = PMC_HASH_PTR(p, pmc_processhashmask); 2644 pph = &pmc_processhash[hindex]; 2645 2646 ppnew = NULL; 2647 2648 /* 2649 * Pre-allocate memory in the PMC_FLAG_ALLOCATE case since we 2650 * cannot call malloc(9) once we hold a spin lock. 2651 */ 2652 if ((mode & PMC_FLAG_ALLOCATE) != 0) 2653 ppnew = malloc(sizeof(struct pmc_process) + md->pmd_npmc * 2654 sizeof(struct pmc_targetstate), M_PMC, M_WAITOK | M_ZERO); 2655 2656 mtx_lock_spin(&pmc_processhash_mtx); 2657 LIST_FOREACH(pp, pph, pp_next) { 2658 if (pp->pp_proc == p) 2659 break; 2660 } 2661 2662 if ((mode & PMC_FLAG_REMOVE) != 0 && pp != NULL) 2663 LIST_REMOVE(pp, pp_next); 2664 2665 if ((mode & PMC_FLAG_ALLOCATE) != 0 && pp == NULL && ppnew != NULL) { 2666 ppnew->pp_proc = p; 2667 LIST_INIT(&ppnew->pp_tds); 2668 ppnew->pp_tdslock = mtx_pool_find(pmc_mtxpool, ppnew); 2669 LIST_INSERT_HEAD(pph, ppnew, pp_next); 2670 mtx_unlock_spin(&pmc_processhash_mtx); 2671 pp = ppnew; 2672 ppnew = NULL; 2673 2674 /* Add thread descriptors for this process' current threads. */ 2675 pmc_add_thread_descriptors_from_proc(p, pp); 2676 } else 2677 mtx_unlock_spin(&pmc_processhash_mtx); 2678 2679 if (ppnew != NULL) 2680 free(ppnew, M_PMC); 2681 return (pp); 2682 } 2683 2684 /* 2685 * Remove a process descriptor from the process hash table. 2686 */ 2687 static void 2688 pmc_remove_process_descriptor(struct pmc_process *pp) 2689 { 2690 KASSERT(pp->pp_refcnt == 0, 2691 ("[pmc,%d] Removing process descriptor %p with count %d", 2692 __LINE__, pp, pp->pp_refcnt)); 2693 2694 mtx_lock_spin(&pmc_processhash_mtx); 2695 LIST_REMOVE(pp, pp_next); 2696 mtx_unlock_spin(&pmc_processhash_mtx); 2697 } 2698 2699 /* 2700 * Destroy a process descriptor. 2701 */ 2702 static void 2703 pmc_destroy_process_descriptor(struct pmc_process *pp) 2704 { 2705 struct pmc_thread *pmc_td; 2706 2707 while ((pmc_td = LIST_FIRST(&pp->pp_tds)) != NULL) { 2708 LIST_REMOVE(pmc_td, pt_next); 2709 pmc_thread_descriptor_pool_free(pmc_td); 2710 } 2711 free(pp, M_PMC); 2712 } 2713 2714 /* 2715 * Find an owner descriptor corresponding to proc 'p'. 2716 */ 2717 static struct pmc_owner * 2718 pmc_find_owner_descriptor(struct proc *p) 2719 { 2720 struct pmc_owner *po; 2721 struct pmc_ownerhash *poh; 2722 uint32_t hindex; 2723 2724 hindex = PMC_HASH_PTR(p, pmc_ownerhashmask); 2725 poh = &pmc_ownerhash[hindex]; 2726 2727 po = NULL; 2728 LIST_FOREACH(po, poh, po_next) { 2729 if (po->po_owner == p) 2730 break; 2731 } 2732 2733 PMCDBG5(OWN,FND,1, "find-owner proc=%p (%d, %s) hindex=0x%x -> " 2734 "pmc-owner=%p", p, p->p_pid, p->p_comm, hindex, po); 2735 2736 return (po); 2737 } 2738 2739 /* 2740 * Allocate a pmc descriptor and initialize its fields. 2741 */ 2742 static struct pmc * 2743 pmc_allocate_pmc_descriptor(void) 2744 { 2745 struct pmc *pmc; 2746 2747 pmc = malloc(sizeof(struct pmc), M_PMC, M_WAITOK | M_ZERO); 2748 pmc->pm_runcount = counter_u64_alloc(M_WAITOK); 2749 pmc->pm_pcpu_state = malloc(sizeof(struct pmc_pcpu_state) * mp_ncpus, 2750 M_PMC, M_WAITOK | M_ZERO); 2751 PMCDBG1(PMC,ALL,1, "allocate-pmc -> pmc=%p", pmc); 2752 2753 return (pmc); 2754 } 2755 2756 /* 2757 * Destroy a pmc descriptor. 2758 */ 2759 static void 2760 pmc_destroy_pmc_descriptor(struct pmc *pm) 2761 { 2762 2763 KASSERT(pm->pm_state == PMC_STATE_DELETED || 2764 pm->pm_state == PMC_STATE_FREE, 2765 ("[pmc,%d] destroying non-deleted PMC", __LINE__)); 2766 KASSERT(LIST_EMPTY(&pm->pm_targets), 2767 ("[pmc,%d] destroying pmc with targets", __LINE__)); 2768 KASSERT(pm->pm_owner == NULL, 2769 ("[pmc,%d] destroying pmc attached to an owner", __LINE__)); 2770 KASSERT(counter_u64_fetch(pm->pm_runcount) == 0, 2771 ("[pmc,%d] pmc has non-zero run count %ju", __LINE__, 2772 (uintmax_t)counter_u64_fetch(pm->pm_runcount))); 2773 2774 counter_u64_free(pm->pm_runcount); 2775 free(pm->pm_pcpu_state, M_PMC); 2776 free(pm, M_PMC); 2777 } 2778 2779 static void 2780 pmc_wait_for_pmc_idle(struct pmc *pm) 2781 { 2782 #ifdef INVARIANTS 2783 volatile int maxloop; 2784 2785 maxloop = 100 * pmc_cpu_max(); 2786 #endif 2787 /* 2788 * Loop (with a forced context switch) till the PMC's runcount 2789 * comes down to zero. 2790 */ 2791 pmclog_flush(pm->pm_owner, 1); 2792 while (counter_u64_fetch(pm->pm_runcount) > 0) { 2793 pmclog_flush(pm->pm_owner, 1); 2794 #ifdef INVARIANTS 2795 maxloop--; 2796 KASSERT(maxloop > 0, 2797 ("[pmc,%d] (ri%d, rc%ju) waiting too long for " 2798 "pmc to be free", __LINE__, PMC_TO_ROWINDEX(pm), 2799 (uintmax_t)counter_u64_fetch(pm->pm_runcount))); 2800 #endif 2801 pmc_force_context_switch(); 2802 } 2803 } 2804 2805 /* 2806 * This function does the following things: 2807 * 2808 * - detaches the PMC from hardware 2809 * - unlinks all target threads that were attached to it 2810 * - removes the PMC from its owner's list 2811 * - destroys the PMC private mutex 2812 * 2813 * Once this function completes, the given pmc pointer can be freed by 2814 * calling pmc_destroy_pmc_descriptor(). 2815 */ 2816 static void 2817 pmc_release_pmc_descriptor(struct pmc *pm) 2818 { 2819 struct pmc_binding pb; 2820 struct pmc_classdep *pcd; 2821 struct pmc_hw *phw __diagused; 2822 struct pmc_owner *po; 2823 struct pmc_process *pp; 2824 struct pmc_target *ptgt, *tmp; 2825 enum pmc_mode mode; 2826 u_int adjri, ri, cpu; 2827 2828 sx_assert(&pmc_sx, SX_XLOCKED); 2829 KASSERT(pm, ("[pmc,%d] null pmc", __LINE__)); 2830 2831 ri = PMC_TO_ROWINDEX(pm); 2832 pcd = pmc_ri_to_classdep(md, ri, &adjri); 2833 mode = PMC_TO_MODE(pm); 2834 2835 PMCDBG3(PMC,REL,1, "release-pmc pmc=%p ri=%d mode=%d", pm, ri, 2836 mode); 2837 2838 /* 2839 * First, we take the PMC off hardware. 2840 */ 2841 cpu = 0; 2842 if (PMC_IS_SYSTEM_MODE(mode)) { 2843 /* 2844 * A system mode PMC runs on a specific CPU. Switch 2845 * to this CPU and turn hardware off. 2846 */ 2847 pmc_save_cpu_binding(&pb); 2848 cpu = PMC_TO_CPU(pm); 2849 pmc_select_cpu(cpu); 2850 2851 /* switch off non-stalled CPUs */ 2852 pm->pm_pcpu_state[cpu].pps_cpustate = 0; 2853 if (pm->pm_state == PMC_STATE_RUNNING && 2854 pm->pm_pcpu_state[cpu].pps_stalled == 0) { 2855 2856 phw = pmc_pcpu[cpu]->pc_hwpmcs[ri]; 2857 2858 KASSERT(phw->phw_pmc == pm, 2859 ("[pmc, %d] pmc ptr ri(%d) hw(%p) pm(%p)", 2860 __LINE__, ri, phw->phw_pmc, pm)); 2861 PMCDBG2(PMC,REL,2, "stopping cpu=%d ri=%d", cpu, ri); 2862 2863 critical_enter(); 2864 (void)pcd->pcd_stop_pmc(cpu, adjri, pm); 2865 critical_exit(); 2866 } 2867 2868 PMCDBG2(PMC,REL,2, "decfg cpu=%d ri=%d", cpu, ri); 2869 2870 critical_enter(); 2871 (void)pcd->pcd_config_pmc(cpu, adjri, NULL); 2872 critical_exit(); 2873 2874 /* adjust the global and process count of SS mode PMCs */ 2875 if (mode == PMC_MODE_SS && pm->pm_state == PMC_STATE_RUNNING) { 2876 po = pm->pm_owner; 2877 po->po_sscount--; 2878 if (po->po_sscount == 0) { 2879 atomic_subtract_rel_int(&pmc_ss_count, 1); 2880 CK_LIST_REMOVE(po, po_ssnext); 2881 epoch_wait_preempt(global_epoch_preempt); 2882 } 2883 } 2884 pm->pm_state = PMC_STATE_DELETED; 2885 2886 pmc_restore_cpu_binding(&pb); 2887 2888 /* 2889 * We could have references to this PMC structure in the 2890 * per-cpu sample queues. Wait for the queue to drain. 2891 */ 2892 pmc_wait_for_pmc_idle(pm); 2893 2894 } else if (PMC_IS_VIRTUAL_MODE(mode)) { 2895 /* 2896 * A virtual PMC could be running on multiple CPUs at a given 2897 * instant. 2898 * 2899 * By marking its state as DELETED, we ensure that this PMC is 2900 * never further scheduled on hardware. 2901 * 2902 * Then we wait till all CPUs are done with this PMC. 2903 */ 2904 pm->pm_state = PMC_STATE_DELETED; 2905 2906 /* Wait for the PMCs runcount to come to zero. */ 2907 pmc_wait_for_pmc_idle(pm); 2908 2909 /* 2910 * At this point the PMC is off all CPUs and cannot be freshly 2911 * scheduled onto a CPU. It is now safe to unlink all targets 2912 * from this PMC. If a process-record's refcount falls to zero, 2913 * we remove it from the hash table. The module-wide SX lock 2914 * protects us from races. 2915 */ 2916 LIST_FOREACH_SAFE(ptgt, &pm->pm_targets, pt_next, tmp) { 2917 pp = ptgt->pt_process; 2918 pmc_unlink_target_process(pm, pp); /* frees 'ptgt' */ 2919 2920 PMCDBG1(PMC,REL,3, "pp->refcnt=%d", pp->pp_refcnt); 2921 2922 /* 2923 * If the target process record shows that no PMCs are 2924 * attached to it, reclaim its space. 2925 */ 2926 if (pp->pp_refcnt == 0) { 2927 pmc_remove_process_descriptor(pp); 2928 pmc_destroy_process_descriptor(pp); 2929 } 2930 } 2931 2932 cpu = curthread->td_oncpu; /* setup cpu for pmd_release() */ 2933 } 2934 2935 /* 2936 * Release any MD resources. 2937 */ 2938 (void)pcd->pcd_release_pmc(cpu, adjri, pm); 2939 2940 /* 2941 * Update row disposition. 2942 */ 2943 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) 2944 PMC_UNMARK_ROW_STANDALONE(ri); 2945 else 2946 PMC_UNMARK_ROW_THREAD(ri); 2947 2948 /* Unlink from the owner's list. */ 2949 if (pm->pm_owner != NULL) { 2950 LIST_REMOVE(pm, pm_next); 2951 pm->pm_owner = NULL; 2952 } 2953 } 2954 2955 /* 2956 * Register an owner and a pmc. 2957 */ 2958 static int 2959 pmc_register_owner(struct proc *p, struct pmc *pmc) 2960 { 2961 struct pmc_owner *po; 2962 2963 sx_assert(&pmc_sx, SX_XLOCKED); 2964 2965 if ((po = pmc_find_owner_descriptor(p)) == NULL) { 2966 if ((po = pmc_allocate_owner_descriptor(p)) == NULL) 2967 return (ENOMEM); 2968 } 2969 2970 KASSERT(pmc->pm_owner == NULL, 2971 ("[pmc,%d] attempting to own an initialized PMC", __LINE__)); 2972 pmc->pm_owner = po; 2973 2974 LIST_INSERT_HEAD(&po->po_pmcs, pmc, pm_next); 2975 2976 PROC_LOCK(p); 2977 p->p_flag |= P_HWPMC; 2978 PROC_UNLOCK(p); 2979 2980 if ((po->po_flags & PMC_PO_OWNS_LOGFILE) != 0) 2981 pmclog_process_pmcallocate(pmc); 2982 2983 PMCDBG2(PMC,REG,1, "register-owner pmc-owner=%p pmc=%p", 2984 po, pmc); 2985 2986 return (0); 2987 } 2988 2989 /* 2990 * Return the current row disposition: 2991 * == 0 => FREE 2992 * > 0 => PROCESS MODE 2993 * < 0 => SYSTEM MODE 2994 */ 2995 int 2996 pmc_getrowdisp(int ri) 2997 { 2998 return (pmc_pmcdisp[ri]); 2999 } 3000 3001 /* 3002 * Check if a PMC at row index 'ri' can be allocated to the current 3003 * process. 3004 * 3005 * Allocation can fail if: 3006 * - the current process is already being profiled by a PMC at index 'ri', 3007 * attached to it via OP_PMCATTACH. 3008 * - the current process has already allocated a PMC at index 'ri' 3009 * via OP_ALLOCATE. 3010 */ 3011 static bool 3012 pmc_can_allocate_rowindex(struct proc *p, unsigned int ri, int cpu) 3013 { 3014 struct pmc *pm; 3015 struct pmc_owner *po; 3016 struct pmc_process *pp; 3017 enum pmc_mode mode; 3018 3019 PMCDBG5(PMC,ALR,1, "can-allocate-rowindex proc=%p (%d, %s) ri=%d " 3020 "cpu=%d", p, p->p_pid, p->p_comm, ri, cpu); 3021 3022 /* 3023 * We shouldn't have already allocated a process-mode PMC at 3024 * row index 'ri'. 3025 * 3026 * We shouldn't have allocated a system-wide PMC on the same 3027 * CPU and same RI. 3028 */ 3029 if ((po = pmc_find_owner_descriptor(p)) != NULL) { 3030 LIST_FOREACH(pm, &po->po_pmcs, pm_next) { 3031 if (PMC_TO_ROWINDEX(pm) == ri) { 3032 mode = PMC_TO_MODE(pm); 3033 if (PMC_IS_VIRTUAL_MODE(mode)) 3034 return (false); 3035 if (PMC_IS_SYSTEM_MODE(mode) && 3036 PMC_TO_CPU(pm) == cpu) 3037 return (false); 3038 } 3039 } 3040 } 3041 3042 /* 3043 * We also shouldn't be the target of any PMC at this index 3044 * since otherwise a PMC_ATTACH to ourselves will fail. 3045 */ 3046 if ((pp = pmc_find_process_descriptor(p, 0)) != NULL) 3047 if (pp->pp_pmcs[ri].pp_pmc != NULL) 3048 return (false); 3049 3050 PMCDBG4(PMC,ALR,2, "can-allocate-rowindex proc=%p (%d, %s) ri=%d ok", 3051 p, p->p_pid, p->p_comm, ri); 3052 return (true); 3053 } 3054 3055 /* 3056 * Check if a given PMC at row index 'ri' can be currently used in 3057 * mode 'mode'. 3058 */ 3059 static bool 3060 pmc_can_allocate_row(int ri, enum pmc_mode mode) 3061 { 3062 enum pmc_disp disp; 3063 3064 sx_assert(&pmc_sx, SX_XLOCKED); 3065 3066 PMCDBG2(PMC,ALR,1, "can-allocate-row ri=%d mode=%d", ri, mode); 3067 3068 if (PMC_IS_SYSTEM_MODE(mode)) 3069 disp = PMC_DISP_STANDALONE; 3070 else 3071 disp = PMC_DISP_THREAD; 3072 3073 /* 3074 * check disposition for PMC row 'ri': 3075 * 3076 * Expected disposition Row-disposition Result 3077 * 3078 * STANDALONE STANDALONE or FREE proceed 3079 * STANDALONE THREAD fail 3080 * THREAD THREAD or FREE proceed 3081 * THREAD STANDALONE fail 3082 */ 3083 if (!PMC_ROW_DISP_IS_FREE(ri) && 3084 !(disp == PMC_DISP_THREAD && PMC_ROW_DISP_IS_THREAD(ri)) && 3085 !(disp == PMC_DISP_STANDALONE && PMC_ROW_DISP_IS_STANDALONE(ri))) 3086 return (false); 3087 3088 /* 3089 * All OK 3090 */ 3091 PMCDBG2(PMC,ALR,2, "can-allocate-row ri=%d mode=%d ok", ri, mode); 3092 return (true); 3093 } 3094 3095 /* 3096 * Find a PMC descriptor with user handle 'pmcid' for thread 'td'. 3097 */ 3098 static struct pmc * 3099 pmc_find_pmc_descriptor_in_process(struct pmc_owner *po, pmc_id_t pmcid) 3100 { 3101 struct pmc *pm; 3102 3103 KASSERT(PMC_ID_TO_ROWINDEX(pmcid) < md->pmd_npmc, 3104 ("[pmc,%d] Illegal pmc index %d (max %d)", __LINE__, 3105 PMC_ID_TO_ROWINDEX(pmcid), md->pmd_npmc)); 3106 3107 LIST_FOREACH(pm, &po->po_pmcs, pm_next) { 3108 if (pm->pm_id == pmcid) 3109 return (pm); 3110 } 3111 3112 return (NULL); 3113 } 3114 3115 static int 3116 pmc_find_pmc(pmc_id_t pmcid, struct pmc **pmc) 3117 { 3118 struct pmc *pm, *opm; 3119 struct pmc_owner *po; 3120 struct pmc_process *pp; 3121 3122 PMCDBG1(PMC,FND,1, "find-pmc id=%d", pmcid); 3123 if (PMC_ID_TO_ROWINDEX(pmcid) >= md->pmd_npmc) 3124 return (EINVAL); 3125 3126 if ((po = pmc_find_owner_descriptor(curthread->td_proc)) == NULL) { 3127 /* 3128 * In case of PMC_F_DESCENDANTS child processes we will not find 3129 * the current process in the owners hash list. Find the owner 3130 * process first and from there lookup the po. 3131 */ 3132 pp = pmc_find_process_descriptor(curthread->td_proc, 3133 PMC_FLAG_NONE); 3134 if (pp == NULL) 3135 return (ESRCH); 3136 opm = pp->pp_pmcs[PMC_ID_TO_ROWINDEX(pmcid)].pp_pmc; 3137 if (opm == NULL) 3138 return (ESRCH); 3139 if ((opm->pm_flags & 3140 (PMC_F_ATTACHED_TO_OWNER | PMC_F_DESCENDANTS)) != 3141 (PMC_F_ATTACHED_TO_OWNER | PMC_F_DESCENDANTS)) 3142 return (ESRCH); 3143 3144 po = opm->pm_owner; 3145 } 3146 3147 if ((pm = pmc_find_pmc_descriptor_in_process(po, pmcid)) == NULL) 3148 return (EINVAL); 3149 3150 PMCDBG2(PMC,FND,2, "find-pmc id=%d -> pmc=%p", pmcid, pm); 3151 3152 *pmc = pm; 3153 return (0); 3154 } 3155 3156 /* 3157 * Start a PMC. 3158 */ 3159 static int 3160 pmc_start(struct pmc *pm) 3161 { 3162 struct pmc_binding pb; 3163 struct pmc_classdep *pcd; 3164 struct pmc_owner *po; 3165 pmc_value_t v; 3166 enum pmc_mode mode; 3167 int adjri, error, cpu, ri; 3168 3169 KASSERT(pm != NULL, 3170 ("[pmc,%d] null pm", __LINE__)); 3171 3172 mode = PMC_TO_MODE(pm); 3173 ri = PMC_TO_ROWINDEX(pm); 3174 pcd = pmc_ri_to_classdep(md, ri, &adjri); 3175 3176 error = 0; 3177 po = pm->pm_owner; 3178 3179 PMCDBG3(PMC,OPS,1, "start pmc=%p mode=%d ri=%d", pm, mode, ri); 3180 3181 po = pm->pm_owner; 3182 3183 /* 3184 * Disallow PMCSTART if a logfile is required but has not been 3185 * configured yet. 3186 */ 3187 if ((pm->pm_flags & PMC_F_NEEDS_LOGFILE) != 0 && 3188 (po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) 3189 return (EDOOFUS); /* programming error */ 3190 3191 /* 3192 * If this is a sampling mode PMC, log mapping information for 3193 * the kernel modules that are currently loaded. 3194 */ 3195 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 3196 pmc_log_kernel_mappings(pm); 3197 3198 if (PMC_IS_VIRTUAL_MODE(mode)) { 3199 /* 3200 * If a PMCATTACH has never been done on this PMC, 3201 * attach it to its owner process. 3202 */ 3203 if (LIST_EMPTY(&pm->pm_targets)) { 3204 error = (pm->pm_flags & PMC_F_ATTACH_DONE) != 0 ? 3205 ESRCH : pmc_attach_process(po->po_owner, pm); 3206 } 3207 3208 /* 3209 * If the PMC is attached to its owner, then force a context 3210 * switch to ensure that the MD state gets set correctly. 3211 */ 3212 if (error == 0) { 3213 pm->pm_state = PMC_STATE_RUNNING; 3214 if ((pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) != 0) 3215 pmc_force_context_switch(); 3216 } 3217 3218 return (error); 3219 } 3220 3221 /* 3222 * A system-wide PMC. 3223 * 3224 * Add the owner to the global list if this is a system-wide 3225 * sampling PMC. 3226 */ 3227 if (mode == PMC_MODE_SS) { 3228 /* 3229 * Log mapping information for all existing processes in the 3230 * system. Subsequent mappings are logged as they happen; 3231 * see pmc_process_mmap(). 3232 */ 3233 if (po->po_logprocmaps == 0) { 3234 pmc_log_all_process_mappings(po); 3235 po->po_logprocmaps = 1; 3236 } 3237 po->po_sscount++; 3238 if (po->po_sscount == 1) { 3239 atomic_add_rel_int(&pmc_ss_count, 1); 3240 CK_LIST_INSERT_HEAD(&pmc_ss_owners, po, po_ssnext); 3241 PMCDBG1(PMC,OPS,1, "po=%p in global list", po); 3242 } 3243 } 3244 3245 /* 3246 * Move to the CPU associated with this 3247 * PMC, and start the hardware. 3248 */ 3249 pmc_save_cpu_binding(&pb); 3250 cpu = PMC_TO_CPU(pm); 3251 if (!pmc_cpu_is_active(cpu)) { 3252 return (EXTERROR(ENXIO, "PMC CPU %ju is not active for start", 3253 (uintmax_t)cpu)); 3254 } 3255 pmc_select_cpu(cpu); 3256 3257 /* 3258 * global PMCs are configured at allocation time 3259 * so write out the initial value and start the PMC. 3260 */ 3261 pm->pm_state = PMC_STATE_RUNNING; 3262 3263 critical_enter(); 3264 v = PMC_IS_SAMPLING_MODE(mode) ? pm->pm_sc.pm_reloadcount : 3265 pm->pm_sc.pm_initial; 3266 if ((error = pcd->pcd_write_pmc(cpu, adjri, pm, v)) == 0) { 3267 /* If a sampling mode PMC, reset stalled state. */ 3268 if (PMC_IS_SAMPLING_MODE(mode)) 3269 pm->pm_pcpu_state[cpu].pps_stalled = 0; 3270 3271 /* Indicate that we desire this to run. Start it. */ 3272 pm->pm_pcpu_state[cpu].pps_cpustate = 1; 3273 error = pcd->pcd_start_pmc(cpu, adjri, pm); 3274 } 3275 critical_exit(); 3276 3277 pmc_restore_cpu_binding(&pb); 3278 return (error); 3279 } 3280 3281 /* 3282 * Stop a PMC. 3283 */ 3284 static int 3285 pmc_stop(struct pmc *pm) 3286 { 3287 struct pmc_binding pb; 3288 struct pmc_classdep *pcd; 3289 struct pmc_owner *po; 3290 int adjri, cpu, error, ri; 3291 3292 KASSERT(pm != NULL, ("[pmc,%d] null pmc", __LINE__)); 3293 3294 PMCDBG3(PMC,OPS,1, "stop pmc=%p mode=%d ri=%d", pm, PMC_TO_MODE(pm), 3295 PMC_TO_ROWINDEX(pm)); 3296 3297 pm->pm_state = PMC_STATE_STOPPED; 3298 3299 /* 3300 * If the PMC is a virtual mode one, changing the state to non-RUNNING 3301 * is enough to ensure that the PMC never gets scheduled. 3302 * 3303 * If this PMC is current running on a CPU, then it will handled 3304 * correctly at the time its target process is context switched out. 3305 */ 3306 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) 3307 return (0); 3308 3309 /* 3310 * A system-mode PMC. Move to the CPU associated with this PMC, and 3311 * stop the hardware. We update the 'initial count' so that a 3312 * subsequent PMCSTART will resume counting from the current hardware 3313 * count. 3314 */ 3315 pmc_save_cpu_binding(&pb); 3316 3317 cpu = PMC_TO_CPU(pm); 3318 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 3319 ("[pmc,%d] illegal cpu=%d", __LINE__, cpu)); 3320 if (!pmc_cpu_is_active(cpu)) { 3321 return (EXTERROR(ENXIO, "PMC CPU %ju is not active for stop", 3322 (uintmax_t)cpu)); 3323 } 3324 pmc_select_cpu(cpu); 3325 3326 ri = PMC_TO_ROWINDEX(pm); 3327 pcd = pmc_ri_to_classdep(md, ri, &adjri); 3328 3329 pm->pm_pcpu_state[cpu].pps_cpustate = 0; 3330 critical_enter(); 3331 if ((error = pcd->pcd_stop_pmc(cpu, adjri, pm)) == 0) { 3332 error = pcd->pcd_read_pmc(cpu, adjri, pm, 3333 &pm->pm_sc.pm_initial); 3334 } 3335 critical_exit(); 3336 3337 pmc_restore_cpu_binding(&pb); 3338 3339 /* Remove this owner from the global list of SS PMC owners. */ 3340 po = pm->pm_owner; 3341 if (PMC_TO_MODE(pm) == PMC_MODE_SS) { 3342 po->po_sscount--; 3343 if (po->po_sscount == 0) { 3344 atomic_subtract_rel_int(&pmc_ss_count, 1); 3345 CK_LIST_REMOVE(po, po_ssnext); 3346 epoch_wait_preempt(global_epoch_preempt); 3347 PMCDBG1(PMC,OPS,2,"po=%p removed from global list", po); 3348 } 3349 } 3350 3351 return (error); 3352 } 3353 3354 static struct pmc_classdep * 3355 pmc_class_to_classdep(enum pmc_class class) 3356 { 3357 int n; 3358 3359 for (n = 0; n < md->pmd_nclass; n++) { 3360 if (md->pmd_classdep[n].pcd_class == class) 3361 return (&md->pmd_classdep[n]); 3362 } 3363 return (NULL); 3364 } 3365 3366 #if defined(HWPMC_DEBUG) && defined(KTR) 3367 static const char *pmc_op_to_name[] = { 3368 #undef __PMC_OP 3369 #define __PMC_OP(N, D) #N , 3370 __PMC_OPS() 3371 NULL 3372 }; 3373 #endif 3374 3375 /* 3376 * The syscall interface 3377 */ 3378 3379 #define PMC_GET_SX_XLOCK(...) do { \ 3380 sx_xlock(&pmc_sx); \ 3381 if (pmc_hook == NULL) { \ 3382 sx_xunlock(&pmc_sx); \ 3383 return __VA_ARGS__; \ 3384 } \ 3385 } while (0) 3386 3387 #define PMC_DOWNGRADE_SX() do { \ 3388 sx_downgrade(&pmc_sx); \ 3389 is_sx_downgraded = true; \ 3390 } while (0) 3391 3392 /* 3393 * Main body of PMC_OP_PMCALLOCATE. 3394 */ 3395 static int 3396 pmc_do_op_pmcallocate(struct thread *td, struct pmc_op_pmcallocate *pa) 3397 { 3398 struct proc *p; 3399 struct pmc *pmc; 3400 struct pmc_binding pb; 3401 struct pmc_classdep *pcd; 3402 struct pmc_hw *phw; 3403 enum pmc_mode mode; 3404 enum pmc_class class; 3405 uint32_t caps, flags; 3406 u_int cpu; 3407 int adjri, n; 3408 int error; 3409 3410 class = pa->pm_class; 3411 caps = pa->pm_caps; 3412 flags = pa->pm_flags; 3413 mode = pa->pm_mode; 3414 cpu = pa->pm_cpu; 3415 3416 p = td->td_proc; 3417 /* Requested mode must exist. */ 3418 if ((mode != PMC_MODE_SS && mode != PMC_MODE_SC && 3419 mode != PMC_MODE_TS && mode != PMC_MODE_TC)) 3420 return (EXTERROR(EINVAL, "Invalid PMC mode %ju", 3421 (uintmax_t)mode)); 3422 3423 /* Requested CPU must be valid. */ 3424 if (cpu != PMC_CPU_ANY && cpu >= pmc_cpu_max()) 3425 return (EXTERROR(EINVAL, "Invalid PMC CPU %ju", 3426 (uintmax_t)cpu)); 3427 3428 /* 3429 * Virtual PMCs should only ask for a default CPU. 3430 * System mode PMCs need to specify a non-default CPU. 3431 */ 3432 if ((PMC_IS_VIRTUAL_MODE(mode) && cpu != PMC_CPU_ANY) || 3433 (PMC_IS_SYSTEM_MODE(mode) && cpu == PMC_CPU_ANY)) { 3434 if (PMC_IS_VIRTUAL_MODE(mode)) { 3435 return (EXTERROR(EINVAL, 3436 "PMC mode %ju requires the default CPU", 3437 (uintmax_t)mode)); 3438 } 3439 return (EXTERROR(EINVAL, 3440 "PMC mode %ju requires an explicit CPU", 3441 (uintmax_t)mode)); 3442 } 3443 3444 /* 3445 * Check that an inactive CPU is not being asked for. 3446 */ 3447 if (PMC_IS_SYSTEM_MODE(mode) && !pmc_cpu_is_active(cpu)) 3448 return (EXTERROR(ENXIO, "PMC CPU %ju is not active", 3449 (uintmax_t)cpu)); 3450 3451 /* 3452 * Refuse an allocation for a system-wide PMC if this process has been 3453 * jailed, or if this process lacks super-user credentials and the 3454 * sysctl tunable 'security.bsd.unprivileged_syspmcs' is zero. 3455 */ 3456 if (PMC_IS_SYSTEM_MODE(mode)) { 3457 if (jailed(td->td_ucred)) 3458 return (EPERM); 3459 if (!pmc_unprivileged_syspmcs) { 3460 error = priv_check(td, PRIV_PMC_SYSTEM); 3461 if (error != 0) 3462 return (error); 3463 } 3464 } 3465 3466 /* 3467 * Look for valid values for 'pm_flags'. 3468 */ 3469 if ((flags & ~(PMC_F_DESCENDANTS | PMC_F_LOG_PROCCSW | 3470 PMC_F_LOG_PROCEXIT | PMC_F_CALLCHAIN | PMC_F_USERCALLCHAIN | 3471 PMC_F_EV_PMU)) != 0) 3472 return (EXTERROR(EINVAL, "Invalid PMC flags %#jx", 3473 (uintmax_t)flags)); 3474 3475 /* PMC_F_USERCALLCHAIN is only valid with PMC_F_CALLCHAIN. */ 3476 if ((flags & (PMC_F_CALLCHAIN | PMC_F_USERCALLCHAIN)) == 3477 PMC_F_USERCALLCHAIN) 3478 return (EXTERROR(EINVAL, 3479 "PMC_F_USERCALLCHAIN requires PMC_F_CALLCHAIN")); 3480 3481 /* PMC_F_USERCALLCHAIN is only valid for sampling mode. */ 3482 if ((flags & PMC_F_USERCALLCHAIN) != 0 && mode != PMC_MODE_TS && 3483 mode != PMC_MODE_SS) 3484 return (EXTERROR(EINVAL, 3485 "PMC_F_USERCALLCHAIN requires sampling mode")); 3486 3487 /* Process logging options are not allowed for system PMCs. */ 3488 if (PMC_IS_SYSTEM_MODE(mode) && 3489 (flags & (PMC_F_LOG_PROCCSW | PMC_F_LOG_PROCEXIT)) != 0) 3490 return (EXTERROR(EINVAL, 3491 "Process logging flags are not valid for system PMCs")); 3492 3493 /* 3494 * All sampling mode PMCs need to be able to interrupt the CPU. 3495 */ 3496 if (PMC_IS_SAMPLING_MODE(mode)) 3497 caps |= PMC_CAP_INTERRUPT; 3498 3499 /* A valid class specifier should have been passed in. */ 3500 pcd = pmc_class_to_classdep(class); 3501 if (pcd == NULL) 3502 return (EXTERROR(EINVAL, "Invalid PMC class %ju", 3503 (uintmax_t)class)); 3504 3505 /* The requested PMC capabilities should be feasible. */ 3506 if ((pcd->pcd_caps & caps) != caps) 3507 return (EXTERROR(EOPNOTSUPP, 3508 "Requested PMC capabilities %#jx are not supported", 3509 (uintmax_t)caps)); 3510 3511 PMCDBG4(PMC,ALL,2, "event=%d caps=0x%x mode=%d cpu=%d", pa->pm_ev, 3512 caps, mode, cpu); 3513 3514 pmc = pmc_allocate_pmc_descriptor(); 3515 pmc->pm_id = PMC_ID_MAKE_ID(cpu, pa->pm_mode, class, PMC_ID_INVALID); 3516 pmc->pm_event = pa->pm_ev; 3517 pmc->pm_state = PMC_STATE_FREE; 3518 pmc->pm_caps = caps; 3519 pmc->pm_flags = flags; 3520 3521 /* XXX set lower bound on sampling for process counters */ 3522 if (PMC_IS_SAMPLING_MODE(mode)) { 3523 /* 3524 * Don't permit requested sample rate to be less than 3525 * pmc_mincount. 3526 */ 3527 if (pa->pm_count < MAX(1, pmc_mincount)) 3528 log(LOG_WARNING, "pmcallocate: passed sample " 3529 "rate %ju - setting to %u\n", 3530 (uintmax_t)pa->pm_count, 3531 MAX(1, pmc_mincount)); 3532 pmc->pm_sc.pm_reloadcount = MAX(MAX(1, pmc_mincount), 3533 pa->pm_count); 3534 } else 3535 pmc->pm_sc.pm_initial = pa->pm_count; 3536 3537 /* switch thread to CPU 'cpu' */ 3538 pmc_save_cpu_binding(&pb); 3539 3540 #define PMC_IS_SHAREABLE_PMC(cpu, n) \ 3541 (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_state & \ 3542 PMC_PHW_FLAG_IS_SHAREABLE) 3543 #define PMC_IS_UNALLOCATED(cpu, n) \ 3544 (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_pmc == NULL) 3545 3546 if (PMC_IS_SYSTEM_MODE(mode)) { 3547 pmc_select_cpu(cpu); 3548 for (n = pcd->pcd_ri; n < md->pmd_npmc; n++) { 3549 pcd = pmc_ri_to_classdep(md, n, &adjri); 3550 3551 if (!pmc_can_allocate_row(n, mode) || 3552 !pmc_can_allocate_rowindex(p, n, cpu)) 3553 continue; 3554 if (!PMC_IS_UNALLOCATED(cpu, n) && 3555 !PMC_IS_SHAREABLE_PMC(cpu, n)) 3556 continue; 3557 3558 if (pcd->pcd_allocate_pmc(cpu, adjri, pmc, pa) == 0) { 3559 /* Success. */ 3560 break; 3561 } 3562 } 3563 } else { 3564 /* Process virtual mode */ 3565 for (n = pcd->pcd_ri; n < md->pmd_npmc; n++) { 3566 pcd = pmc_ri_to_classdep(md, n, &adjri); 3567 3568 if (!pmc_can_allocate_row(n, mode) || 3569 !pmc_can_allocate_rowindex(p, n, PMC_CPU_ANY)) 3570 continue; 3571 3572 if (pcd->pcd_allocate_pmc(td->td_oncpu, adjri, pmc, 3573 pa) == 0) { 3574 /* Success. */ 3575 break; 3576 } 3577 } 3578 } 3579 3580 #undef PMC_IS_UNALLOCATED 3581 #undef PMC_IS_SHAREABLE_PMC 3582 3583 pmc_restore_cpu_binding(&pb); 3584 3585 if (n == md->pmd_npmc) { 3586 pmc_destroy_pmc_descriptor(pmc); 3587 /* Preserve a more specific error from the class allocator. */ 3588 if ((td->td_pflags2 & TDP2_EXTERR) != 0) 3589 return (EINVAL); 3590 return (EXTERROR(EINVAL, 3591 "No PMC row accepted the allocation request")); 3592 } 3593 3594 /* Fill in the correct value in the ID field. */ 3595 pmc->pm_id = PMC_ID_MAKE_ID(cpu, mode, class, n); 3596 3597 PMCDBG5(PMC,ALL,2, "ev=%d class=%d mode=%d n=%d -> pmcid=%x", 3598 pmc->pm_event, class, mode, n, pmc->pm_id); 3599 3600 /* Process mode PMCs with logging enabled need log files. */ 3601 if ((pmc->pm_flags & (PMC_F_LOG_PROCEXIT | PMC_F_LOG_PROCCSW)) != 0) 3602 pmc->pm_flags |= PMC_F_NEEDS_LOGFILE; 3603 3604 /* All system mode sampling PMCs require a log file. */ 3605 if (PMC_IS_SAMPLING_MODE(mode) && PMC_IS_SYSTEM_MODE(mode)) 3606 pmc->pm_flags |= PMC_F_NEEDS_LOGFILE; 3607 3608 /* 3609 * Configure global pmc's immediately. 3610 */ 3611 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pmc))) { 3612 pmc_save_cpu_binding(&pb); 3613 pmc_select_cpu(cpu); 3614 3615 phw = pmc_pcpu[cpu]->pc_hwpmcs[n]; 3616 pcd = pmc_ri_to_classdep(md, n, &adjri); 3617 3618 if ((phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0) { 3619 (void)pcd->pcd_release_pmc(cpu, adjri, pmc); 3620 pmc_destroy_pmc_descriptor(pmc); 3621 pmc_restore_cpu_binding(&pb); 3622 return (EXTERROR(EPERM, 3623 "PMC row %ju on CPU %ju is not enabled", 3624 (uintmax_t)n, (uintmax_t)cpu)); 3625 } 3626 if ((error = pcd->pcd_config_pmc(cpu, adjri, pmc)) != 0) { 3627 (void)pcd->pcd_release_pmc(cpu, adjri, pmc); 3628 pmc_destroy_pmc_descriptor(pmc); 3629 pmc_restore_cpu_binding(&pb); 3630 return (EXTERROR(EPERM, 3631 "PMC configuration failed for row %ju on CPU %ju", 3632 (uintmax_t)n, (uintmax_t)cpu)); 3633 } 3634 3635 pmc_restore_cpu_binding(&pb); 3636 } 3637 3638 pmc->pm_state = PMC_STATE_ALLOCATED; 3639 pmc->pm_class = class; 3640 3641 /* 3642 * Mark row disposition. 3643 */ 3644 if (PMC_IS_SYSTEM_MODE(mode)) 3645 PMC_MARK_ROW_STANDALONE(n); 3646 else 3647 PMC_MARK_ROW_THREAD(n); 3648 3649 /* 3650 * Register this PMC with the current thread as its owner. 3651 */ 3652 error = pmc_register_owner(p, pmc); 3653 if (error != 0) { 3654 pmc_release_pmc_descriptor(pmc); 3655 pmc_destroy_pmc_descriptor(pmc); 3656 return (EXTERROR(error, "Failed to register PMC owner")); 3657 } 3658 3659 /* 3660 * Return the allocated index. 3661 */ 3662 pa->pm_pmcid = pmc->pm_id; 3663 return (0); 3664 } 3665 3666 /* 3667 * Main body of PMC_OP_PMCATTACH. 3668 */ 3669 static int 3670 pmc_do_op_pmcattach(struct thread *td, struct pmc_op_pmcattach a) 3671 { 3672 struct pmc *pm; 3673 struct proc *p; 3674 int error; 3675 3676 sx_assert(&pmc_sx, SX_XLOCKED); 3677 3678 if (a.pm_pid < 0) { 3679 return (EXTERROR(EINVAL, "Invalid PMC attach pid %jd", 3680 (intmax_t)a.pm_pid)); 3681 } else if (a.pm_pid == 0) { 3682 a.pm_pid = td->td_proc->p_pid; 3683 } 3684 3685 error = pmc_find_pmc(a.pm_pmc, &pm); 3686 if (error != 0) 3687 return (error); 3688 3689 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) 3690 return (EXTERROR(EINVAL, 3691 "Cannot attach a system-mode PMC to a process")); 3692 3693 /* PMCs may be (re)attached only when allocated or stopped */ 3694 if (pm->pm_state == PMC_STATE_RUNNING) { 3695 return (EXTERROR(EBUSY, 3696 "PMC must be stopped before attach")); 3697 } else if (pm->pm_state != PMC_STATE_ALLOCATED && 3698 pm->pm_state != PMC_STATE_STOPPED) { 3699 return (EXTERROR(EINVAL, 3700 "PMC state %ju does not allow attach", 3701 (uintmax_t)pm->pm_state)); 3702 } 3703 3704 /* lookup pid */ 3705 if ((p = pfind(a.pm_pid)) == NULL) 3706 return (ESRCH); 3707 3708 /* 3709 * Ignore processes that are working on exiting. 3710 */ 3711 if ((p->p_flag & P_WEXIT) != 0) { 3712 PROC_UNLOCK(p); /* pfind() returns a locked process */ 3713 return (ESRCH); 3714 } 3715 3716 /* 3717 * We are allowed to attach a PMC to a process if we can debug it. 3718 */ 3719 error = p_candebug(curthread, p); 3720 3721 PROC_UNLOCK(p); 3722 3723 if (error == 0) 3724 error = pmc_attach_process(p, pm); 3725 3726 return (error); 3727 } 3728 3729 /* 3730 * Main body of PMC_OP_PMCDETACH. 3731 */ 3732 static int 3733 pmc_do_op_pmcdetach(struct thread *td, struct pmc_op_pmcattach a) 3734 { 3735 struct pmc *pm; 3736 struct proc *p; 3737 int error; 3738 3739 if (a.pm_pid < 0) { 3740 return (EXTERROR(EINVAL, "Invalid PMC detach pid %jd", 3741 (intmax_t)a.pm_pid)); 3742 } else if (a.pm_pid == 0) 3743 a.pm_pid = td->td_proc->p_pid; 3744 3745 error = pmc_find_pmc(a.pm_pmc, &pm); 3746 if (error != 0) 3747 return (error); 3748 3749 if ((p = pfind(a.pm_pid)) == NULL) 3750 return (ESRCH); 3751 3752 /* 3753 * Treat processes that are in the process of exiting as if they were 3754 * not present. 3755 */ 3756 if ((p->p_flag & P_WEXIT) != 0) { 3757 PROC_UNLOCK(p); 3758 return (ESRCH); 3759 } 3760 3761 PROC_UNLOCK(p); /* pfind() returns a locked process */ 3762 3763 if (error == 0) 3764 error = pmc_detach_process(p, pm); 3765 3766 return (error); 3767 } 3768 3769 /* 3770 * Main body of PMC_OP_PMCRELEASE. 3771 */ 3772 static int 3773 pmc_do_op_pmcrelease(pmc_id_t pmcid) 3774 { 3775 struct pmc_owner *po; 3776 struct pmc *pm; 3777 int error; 3778 3779 /* 3780 * Find PMC pointer for the named PMC. 3781 * 3782 * Use pmc_release_pmc_descriptor() to switch off the 3783 * PMC, remove all its target threads, and remove the 3784 * PMC from its owner's list. 3785 * 3786 * Remove the owner record if this is the last PMC 3787 * owned. 3788 * 3789 * Free up space. 3790 */ 3791 error = pmc_find_pmc(pmcid, &pm); 3792 if (error != 0) 3793 return (error); 3794 3795 po = pm->pm_owner; 3796 pmc_release_pmc_descriptor(pm); 3797 pmc_maybe_remove_owner(po); 3798 pmc_destroy_pmc_descriptor(pm); 3799 3800 return (error); 3801 } 3802 3803 /* 3804 * Main body of PMC_OP_PMCRW. 3805 */ 3806 static int 3807 pmc_do_op_pmcrw(const struct pmc_op_pmcrw *prw, pmc_value_t *valp) 3808 { 3809 struct pmc_binding pb; 3810 struct pmc_classdep *pcd; 3811 struct pmc *pm; 3812 u_int cpu, ri, adjri; 3813 int error; 3814 3815 PMCDBG2(PMC,OPS,1, "rw id=%d flags=0x%x", prw->pm_pmcid, prw->pm_flags); 3816 3817 /* Must have at least one flag set. */ 3818 if ((prw->pm_flags & (PMC_F_OLDVALUE | PMC_F_NEWVALUE)) == 0) 3819 return (EXTERROR(EINVAL, 3820 "PMCRW requires PMC_F_OLDVALUE and/or PMC_F_NEWVALUE")); 3821 3822 /* Locate PMC descriptor. */ 3823 error = pmc_find_pmc(prw->pm_pmcid, &pm); 3824 if (error != 0) 3825 return (error); 3826 3827 /* Can't read a PMC that hasn't been started. */ 3828 if (pm->pm_state != PMC_STATE_ALLOCATED && 3829 pm->pm_state != PMC_STATE_STOPPED && 3830 pm->pm_state != PMC_STATE_RUNNING) 3831 return (EXTERROR(EINVAL, 3832 "PMC state %ju does not allow read/write", 3833 (uintmax_t)pm->pm_state)); 3834 3835 /* Writing a new value is allowed only for 'STOPPED' PMCs. */ 3836 if (pm->pm_state == PMC_STATE_RUNNING && 3837 (prw->pm_flags & PMC_F_NEWVALUE) != 0) 3838 return (EXTERROR(EBUSY, 3839 "Cannot write a PMC while it is running")); 3840 3841 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) { 3842 /* 3843 * If this PMC is attached to its owner (i.e., the process 3844 * requesting this operation) and is running, then attempt to 3845 * get an upto-date reading from hardware for a READ. Writes 3846 * are only allowed when the PMC is stopped, so only update the 3847 * saved value field. 3848 * 3849 * If the PMC is not running, or is not attached to its owner, 3850 * read/write to the savedvalue field. 3851 */ 3852 3853 ri = PMC_TO_ROWINDEX(pm); 3854 pcd = pmc_ri_to_classdep(md, ri, &adjri); 3855 3856 mtx_pool_lock_spin(pmc_mtxpool, pm); 3857 cpu = curthread->td_oncpu; 3858 3859 if ((prw->pm_flags & PMC_F_OLDVALUE) != 0) { 3860 if ((pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) && 3861 (pm->pm_state == PMC_STATE_RUNNING)) { 3862 error = (*pcd->pcd_read_pmc)(cpu, adjri, pm, 3863 valp); 3864 } else { 3865 *valp = pm->pm_gv.pm_savedvalue; 3866 } 3867 } 3868 3869 if ((prw->pm_flags & PMC_F_NEWVALUE) != 0) 3870 pm->pm_gv.pm_savedvalue = prw->pm_value; 3871 3872 mtx_pool_unlock_spin(pmc_mtxpool, pm); 3873 } else { /* System mode PMCs */ 3874 cpu = PMC_TO_CPU(pm); 3875 ri = PMC_TO_ROWINDEX(pm); 3876 pcd = pmc_ri_to_classdep(md, ri, &adjri); 3877 3878 if (!pmc_cpu_is_active(cpu)) 3879 return (EXTERROR(ENXIO, 3880 "PMC CPU %ju is not active for read/write", 3881 (uintmax_t)cpu)); 3882 3883 /* Move this thread to CPU 'cpu'. */ 3884 pmc_save_cpu_binding(&pb); 3885 pmc_select_cpu(cpu); 3886 critical_enter(); 3887 3888 /* Save old value. */ 3889 if ((prw->pm_flags & PMC_F_OLDVALUE) != 0) 3890 error = (*pcd->pcd_read_pmc)(cpu, adjri, pm, valp); 3891 3892 /* Write out new value. */ 3893 if (error == 0 && (prw->pm_flags & PMC_F_NEWVALUE) != 0) 3894 error = (*pcd->pcd_write_pmc)(cpu, adjri, pm, 3895 prw->pm_value); 3896 3897 critical_exit(); 3898 pmc_restore_cpu_binding(&pb); 3899 if (error != 0) 3900 return (error); 3901 } 3902 3903 #ifdef HWPMC_DEBUG 3904 if ((prw->pm_flags & PMC_F_NEWVALUE) != 0) 3905 PMCDBG3(PMC,OPS,2, "rw id=%d new %jx -> old %jx", 3906 ri, prw->pm_value, *valp); 3907 else 3908 PMCDBG2(PMC,OPS,2, "rw id=%d -> old %jx", ri, *valp); 3909 #endif 3910 return (error); 3911 } 3912 3913 static int 3914 pmc_syscall_handler(struct thread *td, void *syscall_args) 3915 { 3916 struct pmc_syscall_args *c; 3917 void *pmclog_proc_handle; 3918 void *arg; 3919 int error, op; 3920 bool is_sx_downgraded; 3921 3922 c = (struct pmc_syscall_args *)syscall_args; 3923 op = c->pmop_code; 3924 arg = c->pmop_data; 3925 3926 /* PMC isn't set up yet */ 3927 if (pmc_hook == NULL) 3928 return (EINVAL); 3929 3930 if (op == PMC_OP_CONFIGURELOG) { 3931 /* 3932 * We cannot create the logging process inside 3933 * pmclog_configure_log() because there is a LOR 3934 * between pmc_sx and process structure locks. 3935 * Instead, pre-create the process and ignite the loop 3936 * if everything is fine, otherwise direct the process 3937 * to exit. 3938 */ 3939 error = pmclog_proc_create(td, &pmclog_proc_handle); 3940 if (error != 0) 3941 goto done_syscall; 3942 } 3943 3944 PMC_GET_SX_XLOCK(ENOSYS); 3945 is_sx_downgraded = false; 3946 PMCDBG3(MOD,PMS,1, "syscall op=%d \"%s\" arg=%p", op, 3947 pmc_op_to_name[op], arg); 3948 3949 error = 0; 3950 counter_u64_add(pmc_stats.pm_syscalls, 1); 3951 3952 switch (op) { 3953 3954 3955 /* 3956 * Configure a log file. 3957 * 3958 * XXX This OP will be reworked. 3959 */ 3960 3961 case PMC_OP_CONFIGURELOG: 3962 { 3963 struct proc *p; 3964 struct pmc *pm; 3965 struct pmc_owner *po; 3966 struct pmc_op_configurelog cl; 3967 3968 if ((error = copyin(arg, &cl, sizeof(cl))) != 0) { 3969 pmclog_proc_ignite(pmclog_proc_handle, NULL); 3970 break; 3971 } 3972 3973 /* No flags currently implemented */ 3974 if (cl.pm_flags != 0) { 3975 pmclog_proc_ignite(pmclog_proc_handle, NULL); 3976 error = EINVAL; 3977 break; 3978 } 3979 3980 /* mark this process as owning a log file */ 3981 p = td->td_proc; 3982 if ((po = pmc_find_owner_descriptor(p)) == NULL) 3983 if ((po = pmc_allocate_owner_descriptor(p)) == NULL) { 3984 pmclog_proc_ignite(pmclog_proc_handle, NULL); 3985 error = ENOMEM; 3986 break; 3987 } 3988 3989 /* 3990 * If a valid fd was passed in, try to configure that, 3991 * otherwise if 'fd' was less than zero and there was 3992 * a log file configured, flush its buffers and 3993 * de-configure it. 3994 */ 3995 if (cl.pm_logfd >= 0) { 3996 error = pmclog_configure_log(md, po, cl.pm_logfd); 3997 pmclog_proc_ignite(pmclog_proc_handle, error == 0 ? 3998 po : NULL); 3999 } else if (po->po_flags & PMC_PO_OWNS_LOGFILE) { 4000 pmclog_proc_ignite(pmclog_proc_handle, NULL); 4001 error = pmclog_close(po); 4002 if (error == 0) { 4003 LIST_FOREACH(pm, &po->po_pmcs, pm_next) 4004 if (pm->pm_flags & PMC_F_NEEDS_LOGFILE && 4005 pm->pm_state == PMC_STATE_RUNNING) 4006 pmc_stop(pm); 4007 error = pmclog_deconfigure_log(po); 4008 } 4009 } else { 4010 pmclog_proc_ignite(pmclog_proc_handle, NULL); 4011 error = EINVAL; 4012 } 4013 } 4014 break; 4015 4016 /* 4017 * Flush a log file. 4018 */ 4019 4020 case PMC_OP_FLUSHLOG: 4021 { 4022 struct pmc_owner *po; 4023 4024 sx_assert(&pmc_sx, SX_XLOCKED); 4025 4026 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 4027 error = EINVAL; 4028 break; 4029 } 4030 4031 error = pmclog_flush(po, 0); 4032 } 4033 break; 4034 4035 /* 4036 * Close a log file. 4037 */ 4038 4039 case PMC_OP_CLOSELOG: 4040 { 4041 struct pmc_owner *po; 4042 4043 sx_assert(&pmc_sx, SX_XLOCKED); 4044 4045 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 4046 error = EINVAL; 4047 break; 4048 } 4049 4050 error = pmclog_close(po); 4051 } 4052 break; 4053 4054 /* 4055 * Retrieve hardware configuration. 4056 */ 4057 4058 case PMC_OP_GETCPUINFO: /* CPU information */ 4059 { 4060 struct pmc_op_getcpuinfo gci; 4061 struct pmc_classinfo *pci; 4062 struct pmc_classdep *pcd; 4063 int cl; 4064 4065 memset(&gci, 0, sizeof(gci)); 4066 gci.pm_cputype = md->pmd_cputype; 4067 gci.pm_ncpu = pmc_cpu_max(); 4068 gci.pm_npmc = md->pmd_npmc; 4069 gci.pm_nclass = md->pmd_nclass; 4070 pci = gci.pm_classes; 4071 pcd = md->pmd_classdep; 4072 for (cl = 0; cl < md->pmd_nclass; cl++, pci++, pcd++) { 4073 pci->pm_caps = pcd->pcd_caps; 4074 pci->pm_class = pcd->pcd_class; 4075 pci->pm_width = pcd->pcd_width; 4076 pci->pm_num = pcd->pcd_num; 4077 } 4078 error = copyout(&gci, arg, sizeof(gci)); 4079 } 4080 break; 4081 4082 /* 4083 * Retrieve soft events list. 4084 */ 4085 case PMC_OP_GETDYNEVENTINFO: 4086 { 4087 enum pmc_class cl; 4088 enum pmc_event ev; 4089 struct pmc_op_getdyneventinfo *gei; 4090 struct pmc_dyn_event_descr dev; 4091 struct pmc_soft *ps; 4092 uint32_t nevent; 4093 4094 sx_assert(&pmc_sx, SX_LOCKED); 4095 4096 gei = (struct pmc_op_getdyneventinfo *) arg; 4097 4098 if ((error = copyin(&gei->pm_class, &cl, sizeof(cl))) != 0) 4099 break; 4100 4101 /* Only SOFT class is dynamic. */ 4102 if (cl != PMC_CLASS_SOFT) { 4103 error = EINVAL; 4104 break; 4105 } 4106 4107 nevent = 0; 4108 for (ev = PMC_EV_SOFT_FIRST; (int)ev <= PMC_EV_SOFT_LAST; ev++) { 4109 ps = pmc_soft_ev_acquire(ev); 4110 if (ps == NULL) 4111 continue; 4112 bcopy(&ps->ps_ev, &dev, sizeof(dev)); 4113 pmc_soft_ev_release(ps); 4114 4115 error = copyout(&dev, 4116 &gei->pm_events[nevent], 4117 sizeof(struct pmc_dyn_event_descr)); 4118 if (error != 0) 4119 break; 4120 nevent++; 4121 } 4122 if (error != 0) 4123 break; 4124 4125 error = copyout(&nevent, &gei->pm_nevent, 4126 sizeof(nevent)); 4127 } 4128 break; 4129 4130 /* 4131 * Get module statistics 4132 */ 4133 4134 case PMC_OP_GETDRIVERSTATS: 4135 { 4136 struct pmc_op_getdriverstats gms; 4137 #define CFETCH(a, b, field) a.field = counter_u64_fetch(b.field) 4138 CFETCH(gms, pmc_stats, pm_intr_ignored); 4139 CFETCH(gms, pmc_stats, pm_intr_processed); 4140 CFETCH(gms, pmc_stats, pm_intr_bufferfull); 4141 CFETCH(gms, pmc_stats, pm_syscalls); 4142 CFETCH(gms, pmc_stats, pm_syscall_errors); 4143 CFETCH(gms, pmc_stats, pm_buffer_requests); 4144 CFETCH(gms, pmc_stats, pm_buffer_requests_failed); 4145 CFETCH(gms, pmc_stats, pm_log_sweeps); 4146 #undef CFETCH 4147 error = copyout(&gms, arg, sizeof(gms)); 4148 } 4149 break; 4150 4151 4152 /* 4153 * Retrieve module version number 4154 */ 4155 4156 case PMC_OP_GETMODULEVERSION: 4157 { 4158 uint32_t cv, modv; 4159 4160 /* retrieve the client's idea of the ABI version */ 4161 if ((error = copyin(arg, &cv, sizeof(uint32_t))) != 0) 4162 break; 4163 /* don't service clients newer than our driver */ 4164 modv = PMC_VERSION; 4165 if ((cv & 0xFFFF0000) > (modv & 0xFFFF0000)) { 4166 error = EPROGMISMATCH; 4167 break; 4168 } 4169 error = copyout(&modv, arg, sizeof(int)); 4170 } 4171 break; 4172 4173 4174 /* 4175 * Retrieve the state of all the PMCs on a given 4176 * CPU. 4177 */ 4178 4179 case PMC_OP_GETPMCINFO: 4180 { 4181 int ari; 4182 struct pmc *pm; 4183 size_t pmcinfo_size; 4184 uint32_t cpu, n, npmc; 4185 struct pmc_owner *po; 4186 struct pmc_binding pb; 4187 struct pmc_classdep *pcd; 4188 struct pmc_info *p, *pmcinfo; 4189 struct pmc_op_getpmcinfo *gpi; 4190 4191 PMC_DOWNGRADE_SX(); 4192 4193 gpi = (struct pmc_op_getpmcinfo *) arg; 4194 4195 if ((error = copyin(&gpi->pm_cpu, &cpu, sizeof(cpu))) != 0) 4196 break; 4197 4198 if (cpu >= pmc_cpu_max()) { 4199 error = EINVAL; 4200 break; 4201 } 4202 4203 if (!pmc_cpu_is_active(cpu)) { 4204 error = ENXIO; 4205 break; 4206 } 4207 4208 /* switch to CPU 'cpu' */ 4209 pmc_save_cpu_binding(&pb); 4210 pmc_select_cpu(cpu); 4211 4212 npmc = md->pmd_npmc; 4213 4214 pmcinfo_size = npmc * sizeof(struct pmc_info); 4215 pmcinfo = malloc(pmcinfo_size, M_PMC, M_WAITOK | M_ZERO); 4216 4217 p = pmcinfo; 4218 4219 for (n = 0; n < md->pmd_npmc; n++, p++) { 4220 4221 pcd = pmc_ri_to_classdep(md, n, &ari); 4222 4223 KASSERT(pcd != NULL, 4224 ("[pmc,%d] null pcd ri=%d", __LINE__, n)); 4225 4226 if ((error = pcd->pcd_describe(cpu, ari, p, &pm)) != 0) 4227 break; 4228 4229 if (PMC_ROW_DISP_IS_STANDALONE(n)) 4230 p->pm_rowdisp = PMC_DISP_STANDALONE; 4231 else if (PMC_ROW_DISP_IS_THREAD(n)) 4232 p->pm_rowdisp = PMC_DISP_THREAD; 4233 else 4234 p->pm_rowdisp = PMC_DISP_FREE; 4235 4236 p->pm_ownerpid = -1; 4237 4238 if (pm == NULL) /* no PMC associated */ 4239 continue; 4240 4241 po = pm->pm_owner; 4242 4243 KASSERT(po->po_owner != NULL, 4244 ("[pmc,%d] pmc_owner had a null proc pointer", 4245 __LINE__)); 4246 4247 p->pm_ownerpid = po->po_owner->p_pid; 4248 p->pm_mode = PMC_TO_MODE(pm); 4249 p->pm_event = pm->pm_event; 4250 p->pm_flags = pm->pm_flags; 4251 4252 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 4253 p->pm_reloadcount = 4254 pm->pm_sc.pm_reloadcount; 4255 } 4256 4257 pmc_restore_cpu_binding(&pb); 4258 4259 /* now copy out the PMC info collected */ 4260 if (error == 0) 4261 error = copyout(pmcinfo, &gpi->pm_pmcs, pmcinfo_size); 4262 4263 free(pmcinfo, M_PMC); 4264 } 4265 break; 4266 4267 4268 /* 4269 * Set the administrative state of a PMC. I.e. whether 4270 * the PMC is to be used or not. 4271 */ 4272 4273 case PMC_OP_PMCADMIN: 4274 { 4275 int cpu, ri; 4276 enum pmc_state request; 4277 struct pmc_cpu *pc; 4278 struct pmc_hw *phw; 4279 struct pmc_op_pmcadmin pma; 4280 struct pmc_binding pb; 4281 4282 sx_assert(&pmc_sx, SX_XLOCKED); 4283 4284 KASSERT(td == curthread, 4285 ("[pmc,%d] td != curthread", __LINE__)); 4286 4287 error = priv_check(td, PRIV_PMC_MANAGE); 4288 if (error) 4289 break; 4290 4291 if ((error = copyin(arg, &pma, sizeof(pma))) != 0) 4292 break; 4293 4294 cpu = pma.pm_cpu; 4295 4296 if (cpu < 0 || cpu >= (int) pmc_cpu_max()) { 4297 error = EINVAL; 4298 break; 4299 } 4300 4301 if (!pmc_cpu_is_active(cpu)) { 4302 error = ENXIO; 4303 break; 4304 } 4305 4306 request = pma.pm_state; 4307 4308 if (request != PMC_STATE_DISABLED && 4309 request != PMC_STATE_FREE) { 4310 error = EINVAL; 4311 break; 4312 } 4313 4314 ri = pma.pm_pmc; /* pmc id == row index */ 4315 if (ri < 0 || ri >= (int) md->pmd_npmc) { 4316 error = EINVAL; 4317 break; 4318 } 4319 4320 /* 4321 * We can't disable a PMC with a row-index allocated 4322 * for process virtual PMCs. 4323 */ 4324 4325 if (PMC_ROW_DISP_IS_THREAD(ri) && 4326 request == PMC_STATE_DISABLED) { 4327 error = EBUSY; 4328 break; 4329 } 4330 4331 /* 4332 * otherwise, this PMC on this CPU is either free or 4333 * in system-wide mode. 4334 */ 4335 4336 pmc_save_cpu_binding(&pb); 4337 pmc_select_cpu(cpu); 4338 4339 pc = pmc_pcpu[cpu]; 4340 phw = pc->pc_hwpmcs[ri]; 4341 4342 /* 4343 * XXX do we need some kind of 'forced' disable? 4344 */ 4345 4346 if (phw->phw_pmc == NULL) { 4347 if (request == PMC_STATE_DISABLED && 4348 (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED)) { 4349 phw->phw_state &= ~PMC_PHW_FLAG_IS_ENABLED; 4350 PMC_MARK_ROW_STANDALONE(ri); 4351 } else if (request == PMC_STATE_FREE && 4352 (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0) { 4353 phw->phw_state |= PMC_PHW_FLAG_IS_ENABLED; 4354 PMC_UNMARK_ROW_STANDALONE(ri); 4355 } 4356 /* other cases are a no-op */ 4357 } else 4358 error = EBUSY; 4359 4360 pmc_restore_cpu_binding(&pb); 4361 } 4362 break; 4363 4364 4365 /* 4366 * Allocate a PMC. 4367 */ 4368 case PMC_OP_PMCALLOCATE: 4369 { 4370 struct pmc_op_pmcallocate pa; 4371 4372 error = copyin(arg, &pa, sizeof(pa)); 4373 if (error != 0) 4374 break; 4375 4376 error = pmc_do_op_pmcallocate(td, &pa); 4377 if (error != 0) 4378 break; 4379 4380 error = copyout(&pa, arg, sizeof(pa)); 4381 } 4382 break; 4383 4384 /* 4385 * Attach a PMC to a process. 4386 */ 4387 case PMC_OP_PMCATTACH: 4388 { 4389 struct pmc_op_pmcattach a; 4390 4391 error = copyin(arg, &a, sizeof(a)); 4392 if (error != 0) 4393 break; 4394 4395 error = pmc_do_op_pmcattach(td, a); 4396 } 4397 break; 4398 4399 /* 4400 * Detach an attached PMC from a process. 4401 */ 4402 case PMC_OP_PMCDETACH: 4403 { 4404 struct pmc_op_pmcattach a; 4405 4406 error = copyin(arg, &a, sizeof(a)); 4407 if (error != 0) 4408 break; 4409 4410 error = pmc_do_op_pmcdetach(td, a); 4411 } 4412 break; 4413 4414 4415 /* 4416 * Retrieve the MSR number associated with the counter 4417 * 'pmc_id'. This allows processes to directly use RDPMC 4418 * instructions to read their PMCs, without the overhead of a 4419 * system call. 4420 */ 4421 4422 case PMC_OP_PMCGETMSR: 4423 { 4424 int adjri, ri; 4425 struct pmc *pm; 4426 struct pmc_target *pt; 4427 struct pmc_op_getmsr gm; 4428 struct pmc_classdep *pcd; 4429 4430 PMC_DOWNGRADE_SX(); 4431 4432 if ((error = copyin(arg, &gm, sizeof(gm))) != 0) 4433 break; 4434 4435 if ((error = pmc_find_pmc(gm.pm_pmcid, &pm)) != 0) 4436 break; 4437 4438 /* 4439 * The allocated PMC has to be a process virtual PMC, 4440 * i.e., of type MODE_T[CS]. Global PMCs can only be 4441 * read using the PMCREAD operation since they may be 4442 * allocated on a different CPU than the one we could 4443 * be running on at the time of the RDPMC instruction. 4444 * 4445 * The GETMSR operation is not allowed for PMCs that 4446 * are inherited across processes. 4447 */ 4448 4449 if (!PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)) || 4450 (pm->pm_flags & PMC_F_DESCENDANTS)) { 4451 error = EINVAL; 4452 break; 4453 } 4454 4455 /* 4456 * It only makes sense to use a RDPMC (or its 4457 * equivalent instruction on non-x86 architectures) on 4458 * a process that has allocated and attached a PMC to 4459 * itself. Conversely the PMC is only allowed to have 4460 * one process attached to it -- its owner. 4461 */ 4462 4463 if ((pt = LIST_FIRST(&pm->pm_targets)) == NULL || 4464 LIST_NEXT(pt, pt_next) != NULL || 4465 pt->pt_process->pp_proc != pm->pm_owner->po_owner) { 4466 error = EINVAL; 4467 break; 4468 } 4469 4470 ri = PMC_TO_ROWINDEX(pm); 4471 pcd = pmc_ri_to_classdep(md, ri, &adjri); 4472 4473 /* PMC class has no 'GETMSR' support */ 4474 if (pcd->pcd_get_msr == NULL) { 4475 error = ENOSYS; 4476 break; 4477 } 4478 4479 if ((error = (*pcd->pcd_get_msr)(adjri, &gm.pm_msr)) < 0) 4480 break; 4481 4482 if ((error = copyout(&gm, arg, sizeof(gm))) < 0) 4483 break; 4484 4485 /* 4486 * Mark our process as using MSRs. Update machine 4487 * state using a forced context switch. 4488 */ 4489 4490 pt->pt_process->pp_flags |= PMC_PP_ENABLE_MSR_ACCESS; 4491 pmc_force_context_switch(); 4492 4493 } 4494 break; 4495 4496 /* 4497 * Release an allocated PMC. 4498 */ 4499 case PMC_OP_PMCRELEASE: 4500 { 4501 struct pmc_op_simple sp; 4502 4503 error = copyin(arg, &sp, sizeof(sp)); 4504 if (error != 0) 4505 break; 4506 4507 error = pmc_do_op_pmcrelease(sp.pm_pmcid); 4508 } 4509 break; 4510 4511 /* 4512 * Read and/or write a PMC. 4513 */ 4514 case PMC_OP_PMCRW: 4515 { 4516 struct pmc_op_pmcrw prw; 4517 struct pmc_op_pmcrw *pprw; 4518 pmc_value_t oldvalue; 4519 4520 PMC_DOWNGRADE_SX(); 4521 4522 error = copyin(arg, &prw, sizeof(prw)); 4523 if (error != 0) 4524 break; 4525 4526 error = pmc_do_op_pmcrw(&prw, &oldvalue); 4527 if (error != 0) 4528 break; 4529 4530 /* Return old value if requested. */ 4531 if ((prw.pm_flags & PMC_F_OLDVALUE) != 0) { 4532 pprw = arg; 4533 error = copyout(&oldvalue, &pprw->pm_value, 4534 sizeof(prw.pm_value)); 4535 } 4536 } 4537 break; 4538 4539 4540 /* 4541 * Set the sampling rate for a sampling mode PMC and the 4542 * initial count for a counting mode PMC. 4543 */ 4544 4545 case PMC_OP_PMCSETCOUNT: 4546 { 4547 struct pmc *pm; 4548 struct pmc_op_pmcsetcount sc; 4549 4550 PMC_DOWNGRADE_SX(); 4551 4552 if ((error = copyin(arg, &sc, sizeof(sc))) != 0) 4553 break; 4554 4555 if ((error = pmc_find_pmc(sc.pm_pmcid, &pm)) != 0) 4556 break; 4557 4558 if (pm->pm_state == PMC_STATE_RUNNING) { 4559 error = EBUSY; 4560 break; 4561 } 4562 4563 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) { 4564 /* 4565 * Don't permit requested sample rate to be 4566 * less than pmc_mincount. 4567 */ 4568 if (sc.pm_count < MAX(1, pmc_mincount)) 4569 log(LOG_WARNING, "pmcsetcount: passed sample " 4570 "rate %ju - setting to %u\n", 4571 (uintmax_t)sc.pm_count, 4572 MAX(1, pmc_mincount)); 4573 pm->pm_sc.pm_reloadcount = MAX(MAX(1, pmc_mincount), 4574 sc.pm_count); 4575 } else 4576 pm->pm_sc.pm_initial = sc.pm_count; 4577 } 4578 break; 4579 4580 4581 /* 4582 * Start a PMC. 4583 */ 4584 4585 case PMC_OP_PMCSTART: 4586 { 4587 pmc_id_t pmcid; 4588 struct pmc *pm; 4589 struct pmc_op_simple sp; 4590 4591 sx_assert(&pmc_sx, SX_XLOCKED); 4592 4593 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 4594 break; 4595 4596 pmcid = sp.pm_pmcid; 4597 4598 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 4599 break; 4600 4601 KASSERT(pmcid == pm->pm_id, 4602 ("[pmc,%d] pmcid %x != id %x", __LINE__, 4603 pm->pm_id, pmcid)); 4604 4605 if (pm->pm_state == PMC_STATE_RUNNING) /* already running */ 4606 break; 4607 else if (pm->pm_state != PMC_STATE_STOPPED && 4608 pm->pm_state != PMC_STATE_ALLOCATED) { 4609 error = EINVAL; 4610 break; 4611 } 4612 4613 error = pmc_start(pm); 4614 } 4615 break; 4616 4617 4618 /* 4619 * Stop a PMC. 4620 */ 4621 4622 case PMC_OP_PMCSTOP: 4623 { 4624 pmc_id_t pmcid; 4625 struct pmc *pm; 4626 struct pmc_op_simple sp; 4627 4628 PMC_DOWNGRADE_SX(); 4629 4630 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 4631 break; 4632 4633 pmcid = sp.pm_pmcid; 4634 4635 /* 4636 * Mark the PMC as inactive and invoke the MD stop 4637 * routines if needed. 4638 */ 4639 4640 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 4641 break; 4642 4643 KASSERT(pmcid == pm->pm_id, 4644 ("[pmc,%d] pmc id %x != pmcid %x", __LINE__, 4645 pm->pm_id, pmcid)); 4646 4647 if (pm->pm_state == PMC_STATE_STOPPED) /* already stopped */ 4648 break; 4649 else if (pm->pm_state != PMC_STATE_RUNNING) { 4650 error = EINVAL; 4651 break; 4652 } 4653 4654 error = pmc_stop(pm); 4655 } 4656 break; 4657 4658 4659 /* 4660 * Write a user supplied value to the log file. 4661 */ 4662 4663 case PMC_OP_WRITELOG: 4664 { 4665 struct pmc_op_writelog wl; 4666 struct pmc_owner *po; 4667 4668 PMC_DOWNGRADE_SX(); 4669 4670 if ((error = copyin(arg, &wl, sizeof(wl))) != 0) 4671 break; 4672 4673 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 4674 error = EINVAL; 4675 break; 4676 } 4677 4678 if ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) { 4679 error = EINVAL; 4680 break; 4681 } 4682 4683 error = pmclog_process_userlog(po, &wl); 4684 } 4685 break; 4686 4687 /* 4688 * Get the PMC capabilities 4689 */ 4690 4691 case PMC_OP_GETCAPS: 4692 { 4693 struct pmc_op_caps c; 4694 struct pmc *pm; 4695 struct pmc_classdep *pcd; 4696 pmc_id_t pmcid; 4697 int adjri, ri; 4698 4699 PMC_DOWNGRADE_SX(); 4700 4701 if ((error = copyin(arg, &c, sizeof(c))) != 0) 4702 break; 4703 4704 pmcid = c.pm_pmcid; 4705 4706 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 4707 break; 4708 4709 KASSERT(pmcid == pm->pm_id, 4710 ("[pmc,%d] pmc id %x != pmcid %x", __LINE__, 4711 pm->pm_id, pmcid)); 4712 4713 ri = PMC_TO_ROWINDEX(pm); 4714 pcd = pmc_ri_to_classdep(md, ri, &adjri); 4715 4716 /* 4717 * If PMC class has no GETCAPS return the class capabilities 4718 * otherwise get the per counter capabilities. 4719 */ 4720 if (pcd->pcd_get_caps == NULL) { 4721 c.pm_caps = pcd->pcd_caps; 4722 } else { 4723 error = (*pcd->pcd_get_caps)(adjri, &c.pm_caps); 4724 if (error < 0) 4725 break; 4726 } 4727 4728 if ((error = copyout(&c, arg, sizeof(c))) < 0) 4729 break; 4730 } 4731 break; 4732 4733 default: 4734 error = EINVAL; 4735 break; 4736 } 4737 4738 if (is_sx_downgraded) 4739 sx_sunlock(&pmc_sx); 4740 else 4741 sx_xunlock(&pmc_sx); 4742 done_syscall: 4743 if (error) 4744 counter_u64_add(pmc_stats.pm_syscall_errors, 1); 4745 4746 return (error); 4747 } 4748 4749 /* 4750 * Helper functions 4751 */ 4752 4753 /* 4754 * Mark the thread as needing callchain capture and post an AST. The 4755 * actual callchain capture will be done in a context where it is safe 4756 * to take page faults. 4757 */ 4758 static void 4759 pmc_post_callchain_callback(void) 4760 { 4761 struct thread *td; 4762 4763 td = curthread; 4764 4765 /* 4766 * If there is multiple PMCs for the same interrupt ignore new post 4767 */ 4768 if ((td->td_pflags & TDP_CALLCHAIN) != 0) 4769 return; 4770 4771 /* 4772 * Mark this thread as needing callchain capture. 4773 * `td->td_pflags' will be safe to touch because this thread 4774 * was in user space when it was interrupted. 4775 */ 4776 td->td_pflags |= TDP_CALLCHAIN; 4777 4778 /* 4779 * Don't let this thread migrate between CPUs until callchain 4780 * capture completes. 4781 */ 4782 sched_pin(); 4783 4784 return; 4785 } 4786 4787 static void 4788 pmc_multipart_add(struct pmc_sample *ps, int type, int length) 4789 { 4790 int i; 4791 uint8_t *hdr; 4792 4793 MPASS(ps->ps_pc != NULL); 4794 MPASS(ps->ps_nsamples_actual != 0); 4795 4796 hdr = (uint8_t *)ps->ps_pc; 4797 4798 for (i = 0; i < PMC_MULTIPART_HEADER_ENTRIES; i++) { 4799 if (hdr[2 * i] == PMC_CC_MULTIPART_NONE) { 4800 hdr[2 * i] = type; 4801 hdr[2 * i + 1] = length; 4802 ps->ps_nsamples_actual += length; 4803 return; 4804 } 4805 } 4806 4807 KASSERT(false, ("Too many parts in the multipart header!")); 4808 } 4809 4810 static void 4811 pmc_multipart_copydata(struct pmc_sample *ps, struct pmc_multipart *mp) 4812 { 4813 int i, scale; 4814 uint64_t *ps_pc; 4815 4816 MPASS(ps->ps_pc != NULL); 4817 MPASS(ps->ps_nsamples_actual != 0); 4818 4819 ps_pc = (uint64_t *)ps->ps_pc; 4820 4821 for (i = 0; i < mp->pl_length; i++) 4822 ps_pc[i + 1] = mp->pl_mpdata[i]; 4823 4824 scale = sizeof(uint64_t) / sizeof(uintptr_t); 4825 pmc_multipart_add(ps, mp->pl_type, scale * mp->pl_length); 4826 } 4827 4828 /* 4829 * Find a free slot in the per-cpu array of samples and capture the 4830 * current callchain there. If a sample was successfully added, a bit 4831 * is set in mask 'pmc_cpumask' denoting that the DO_SAMPLES hook 4832 * needs to be invoked from the clock handler. 4833 * 4834 * This function is meant to be called from an NMI handler. It cannot 4835 * use any of the locking primitives supplied by the OS. 4836 */ 4837 static int 4838 pmc_add_sample(ring_type_t ring, struct pmc *pm, struct trapframe *tf, 4839 struct pmc_multipart *mp) 4840 { 4841 struct pmc_sample *ps; 4842 struct pmc_samplebuffer *psb; 4843 struct thread *td; 4844 int error, cpu, callchaindepth; 4845 bool inuserspace; 4846 4847 error = 0; 4848 4849 /* 4850 * Allocate space for a sample buffer. 4851 */ 4852 cpu = curcpu; 4853 psb = pmc_pcpu[cpu]->pc_sb[ring]; 4854 inuserspace = TRAPF_USERMODE(tf); 4855 ps = PMC_PROD_SAMPLE(psb); 4856 if (psb->ps_considx != psb->ps_prodidx && 4857 ps->ps_nsamples) { /* in use, reader hasn't caught up */ 4858 pm->pm_pcpu_state[cpu].pps_stalled = 1; 4859 counter_u64_add(pmc_stats.pm_intr_bufferfull, 1); 4860 PMCDBG6(SAM,INT,1,"(spc) cpu=%d pm=%p tf=%p um=%d wr=%d rd=%d", 4861 cpu, pm, tf, inuserspace, 4862 (int)(psb->ps_prodidx & pmc_sample_mask), 4863 (int)(psb->ps_considx & pmc_sample_mask)); 4864 callchaindepth = 1; 4865 error = ENOMEM; 4866 goto done; 4867 } 4868 4869 /* Fill in entry. */ 4870 PMCDBG6(SAM,INT,1,"cpu=%d pm=%p tf=%p um=%d wr=%d rd=%d", cpu, pm, tf, 4871 inuserspace, (int)(psb->ps_prodidx & pmc_sample_mask), 4872 (int)(psb->ps_considx & pmc_sample_mask)); 4873 4874 td = curthread; 4875 ps->ps_pmc = pm; 4876 ps->ps_td = td; 4877 ps->ps_pid = td->td_proc->p_pid; 4878 ps->ps_tid = td->td_tid; 4879 ps->ps_tsc = pmc_rdtsc(); 4880 ps->ps_ticks = ticks; 4881 ps->ps_cpu = cpu; 4882 ps->ps_flags = inuserspace ? PMC_CC_F_USERSPACE : 0; 4883 ps->ps_nsamples_actual = 0; 4884 4885 callchaindepth = (pm->pm_flags & PMC_F_CALLCHAIN) ? 4886 pmc_callchaindepth : 1; 4887 4888 MPASS(ps->ps_pc != NULL); 4889 4890 if (mp != NULL) { 4891 /* Set multipart flag, clear header and copy data */ 4892 ps->ps_flags |= PMC_CC_F_MULTIPART; 4893 ps->ps_pc[0] = 0; 4894 ps->ps_nsamples_actual = 1; 4895 pmc_multipart_copydata(ps, mp); 4896 } 4897 4898 if (callchaindepth == 1) { 4899 ps->ps_pc[ps->ps_nsamples_actual] = PMC_TRAPFRAME_TO_PC(tf); 4900 } else { 4901 /* 4902 * Kernel stack traversals can be done immediately, while we 4903 * defer to an AST for user space traversals. 4904 */ 4905 if (!inuserspace) { 4906 callchaindepth = pmc_save_kernel_callchain( 4907 ps->ps_pc + ps->ps_nsamples_actual, 4908 callchaindepth - ps->ps_nsamples_actual, tf); 4909 callchaindepth += ps->ps_nsamples_actual; 4910 } else { 4911 pmc_post_callchain_callback(); 4912 callchaindepth = PMC_USER_CALLCHAIN_PENDING; 4913 } 4914 } 4915 4916 ps->ps_nsamples = callchaindepth; /* mark entry as in-use */ 4917 if (ring == PMC_UR) { 4918 ps->ps_nsamples_actual = ps->ps_nsamples; 4919 ps->ps_nsamples = PMC_USER_CALLCHAIN_PENDING; 4920 } 4921 4922 KASSERT(counter_u64_fetch(pm->pm_runcount) >= 0, 4923 ("[pmc,%d] pm=%p runcount %ju", __LINE__, pm, 4924 (uintmax_t)counter_u64_fetch(pm->pm_runcount))); 4925 4926 counter_u64_add(pm->pm_runcount, 1); /* hold onto PMC */ 4927 /* increment write pointer */ 4928 psb->ps_prodidx++; 4929 done: 4930 /* mark CPU as needing processing */ 4931 if (callchaindepth != PMC_USER_CALLCHAIN_PENDING) 4932 DPCPU_SET(pmc_sampled, 1); 4933 4934 return (error); 4935 } 4936 4937 /* 4938 * Interrupt processing. 4939 * 4940 * This function may be called from an NMI handler. It cannot use any of the 4941 * locking primitives supplied by the OS. 4942 */ 4943 int 4944 pmc_process_interrupt_mp(int ring, struct pmc *pm, struct trapframe *tf, 4945 struct pmc_multipart *mp) 4946 { 4947 struct thread *td; 4948 4949 td = curthread; 4950 if ((pm->pm_flags & PMC_F_USERCALLCHAIN) && 4951 (td->td_proc->p_flag & P_KPROC) == 0 && !TRAPF_USERMODE(tf)) { 4952 atomic_add_int(&td->td_pmcpend, 1); 4953 return (pmc_add_sample(PMC_UR, pm, tf, mp)); 4954 } 4955 return (pmc_add_sample(ring, pm, tf, mp)); 4956 } 4957 4958 int 4959 pmc_process_interrupt(int ring, struct pmc *pm, struct trapframe *tf) 4960 { 4961 return (pmc_process_interrupt_mp(ring, pm, tf, NULL)); 4962 } 4963 4964 /* 4965 * Capture a user call chain. This function will be called from ast() 4966 * before control returns to userland and before the process gets 4967 * rescheduled. 4968 */ 4969 static void 4970 pmc_capture_user_callchain(int cpu, int ring, struct trapframe *tf) 4971 { 4972 struct pmc *pm; 4973 struct pmc_sample *ps; 4974 struct pmc_samplebuffer *psb; 4975 struct thread *td; 4976 uint64_t considx, prodidx; 4977 int nsamples, nrecords, pass, iter; 4978 int start_ticks __diagused; 4979 4980 psb = pmc_pcpu[cpu]->pc_sb[ring]; 4981 td = curthread; 4982 nrecords = INT_MAX; 4983 pass = 0; 4984 start_ticks = ticks; 4985 4986 KASSERT(td->td_pflags & TDP_CALLCHAIN, 4987 ("[pmc,%d] Retrieving callchain for thread that doesn't want it", 4988 __LINE__)); 4989 restart: 4990 if (ring == PMC_UR) 4991 nrecords = atomic_readandclear_32(&td->td_pmcpend); 4992 4993 for (iter = 0, considx = psb->ps_considx, prodidx = psb->ps_prodidx; 4994 considx < prodidx && iter < pmc_nsamples; considx++, iter++) { 4995 ps = PMC_CONS_SAMPLE_OFF(psb, considx); 4996 4997 /* 4998 * Iterate through all deferred callchain requests. Walk from 4999 * the current read pointer to the current write pointer. 5000 */ 5001 #ifdef INVARIANTS 5002 if (ps->ps_nsamples == PMC_SAMPLE_FREE) { 5003 continue; 5004 } 5005 #endif 5006 if (ps->ps_td != td || 5007 ps->ps_nsamples != PMC_USER_CALLCHAIN_PENDING || 5008 ps->ps_pmc->pm_state != PMC_STATE_RUNNING) 5009 continue; 5010 5011 KASSERT(ps->ps_cpu == cpu, 5012 ("[pmc,%d] cpu mismatch ps_cpu=%d pcpu=%d", __LINE__, 5013 ps->ps_cpu, PCPU_GET(cpuid))); 5014 5015 pm = ps->ps_pmc; 5016 KASSERT(pm->pm_flags & PMC_F_CALLCHAIN, 5017 ("[pmc,%d] Retrieving callchain for PMC that doesn't " 5018 "want it", __LINE__)); 5019 KASSERT(counter_u64_fetch(pm->pm_runcount) > 0, 5020 ("[pmc,%d] runcount %ju", __LINE__, 5021 (uintmax_t)counter_u64_fetch(pm->pm_runcount))); 5022 5023 if (ring == PMC_UR) { 5024 counter_u64_add(pmc_stats.pm_merges, 1); 5025 } 5026 nsamples = ps->ps_nsamples_actual; 5027 5028 /* 5029 * Retrieve the callchain and mark the sample buffer 5030 * as 'processable' by the timer tick sweep code. 5031 */ 5032 if (__predict_true(nsamples < pmc_callchaindepth - 1)) 5033 nsamples += pmc_save_user_callchain(ps->ps_pc + nsamples, 5034 pmc_callchaindepth - nsamples - 1, tf); 5035 5036 /* 5037 * We have to prevent hardclock from potentially overwriting 5038 * this sample between when we read the value and when we set 5039 * it. 5040 */ 5041 spinlock_enter(); 5042 5043 /* 5044 * Verify that the sample hasn't been dropped in the meantime. 5045 */ 5046 if (ps->ps_nsamples == PMC_USER_CALLCHAIN_PENDING) { 5047 ps->ps_nsamples = nsamples; 5048 /* 5049 * If we couldn't get a sample, simply drop the 5050 * reference. 5051 */ 5052 if (nsamples == 0) 5053 counter_u64_add(pm->pm_runcount, -1); 5054 } 5055 spinlock_exit(); 5056 if (nrecords-- == 1) 5057 break; 5058 } 5059 if (__predict_false(ring == PMC_UR && td->td_pmcpend)) { 5060 if (pass == 0) { 5061 pass = 1; 5062 goto restart; 5063 } 5064 /* only collect samples for this part once */ 5065 td->td_pmcpend = 0; 5066 } 5067 5068 #ifdef INVARIANTS 5069 if ((ticks - start_ticks) > hz) 5070 log(LOG_ERR, "%s took %d ticks\n", __func__, (ticks - start_ticks)); 5071 #endif 5072 /* mark CPU as needing processing */ 5073 DPCPU_SET(pmc_sampled, 1); 5074 } 5075 5076 /* 5077 * Process saved PC samples. 5078 */ 5079 static void 5080 pmc_process_samples(int cpu, ring_type_t ring) 5081 { 5082 struct pmc *pm; 5083 struct thread *td; 5084 struct pmc_owner *po; 5085 struct pmc_sample *ps; 5086 struct pmc_classdep *pcd; 5087 struct pmc_samplebuffer *psb; 5088 uint64_t delta __diagused; 5089 int adjri, n; 5090 5091 KASSERT(PCPU_GET(cpuid) == cpu, 5092 ("[pmc,%d] not on the correct CPU pcpu=%d cpu=%d", __LINE__, 5093 PCPU_GET(cpuid), cpu)); 5094 5095 psb = pmc_pcpu[cpu]->pc_sb[ring]; 5096 delta = psb->ps_prodidx - psb->ps_considx; 5097 MPASS(delta <= pmc_nsamples); 5098 MPASS(psb->ps_considx <= psb->ps_prodidx); 5099 for (n = 0; psb->ps_considx < psb->ps_prodidx; psb->ps_considx++, n++) { 5100 ps = PMC_CONS_SAMPLE(psb); 5101 5102 if (__predict_false(ps->ps_nsamples == PMC_SAMPLE_FREE)) 5103 continue; 5104 5105 /* skip non-running samples */ 5106 pm = ps->ps_pmc; 5107 if (pm->pm_state != PMC_STATE_RUNNING) 5108 goto entrydone; 5109 5110 KASSERT(counter_u64_fetch(pm->pm_runcount) > 0, 5111 ("[pmc,%d] pm=%p runcount %ju", __LINE__, pm, 5112 (uintmax_t)counter_u64_fetch(pm->pm_runcount))); 5113 KASSERT(PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)), 5114 ("[pmc,%d] pmc=%p non-sampling mode=%d", __LINE__, 5115 pm, PMC_TO_MODE(pm))); 5116 5117 po = pm->pm_owner; 5118 5119 /* If there is a pending AST wait for completion */ 5120 if (ps->ps_nsamples == PMC_USER_CALLCHAIN_PENDING) { 5121 /* 5122 * If we've been waiting more than 1 tick to 5123 * collect a callchain for this record then 5124 * drop it and move on. 5125 */ 5126 if (ticks - ps->ps_ticks > 1) { 5127 /* 5128 * Track how often we hit this as it will 5129 * preferentially lose user samples 5130 * for long running system calls. 5131 */ 5132 counter_u64_add(pmc_stats.pm_overwrites, 1); 5133 goto entrydone; 5134 } 5135 /* Need a rescan at a later time. */ 5136 DPCPU_SET(pmc_sampled, 1); 5137 break; 5138 } 5139 5140 PMCDBG6(SAM,OPS,1,"cpu=%d pm=%p n=%d fl=%x wr=%d rd=%d", cpu, 5141 pm, ps->ps_nsamples, ps->ps_flags, 5142 (int)(psb->ps_prodidx & pmc_sample_mask), 5143 (int)(psb->ps_considx & pmc_sample_mask)); 5144 5145 /* 5146 * If this is a process-mode PMC that is attached to 5147 * its owner, and if the PC is in user mode, update 5148 * profiling statistics like timer-based profiling 5149 * would have done. 5150 * 5151 * Otherwise, this is either a sampling-mode PMC that 5152 * is attached to a different process than its owner, 5153 * or a system-wide sampling PMC. Dispatch a log 5154 * entry to the PMC's owner process. 5155 */ 5156 if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) { 5157 if (ps->ps_flags & PMC_CC_F_USERSPACE) { 5158 td = FIRST_THREAD_IN_PROC(po->po_owner); 5159 addupc_intr(td, ps->ps_pc[0], 1); 5160 } 5161 } else 5162 pmclog_process_callchain(pm, ps); 5163 5164 entrydone: 5165 ps->ps_nsamples = 0; /* mark entry as free */ 5166 KASSERT(counter_u64_fetch(pm->pm_runcount) > 0, 5167 ("[pmc,%d] pm=%p runcount %ju", __LINE__, pm, 5168 (uintmax_t)counter_u64_fetch(pm->pm_runcount))); 5169 5170 counter_u64_add(pm->pm_runcount, -1); 5171 } 5172 5173 counter_u64_add(pmc_stats.pm_log_sweeps, 1); 5174 5175 /* Do not re-enable stalled PMCs if we failed to process any samples */ 5176 if (n == 0) 5177 return; 5178 5179 /* 5180 * Restart any stalled sampling PMCs on this CPU. 5181 * 5182 * If the NMI handler sets the pm_stalled field of a PMC after 5183 * the check below, we'll end up processing the stalled PMC at 5184 * the next hardclock tick. 5185 */ 5186 for (n = 0; n < md->pmd_npmc; n++) { 5187 pcd = pmc_ri_to_classdep(md, n, &adjri); 5188 KASSERT(pcd != NULL, 5189 ("[pmc,%d] null pcd ri=%d", __LINE__, n)); 5190 (void)(*pcd->pcd_get_config)(cpu, adjri, &pm); 5191 5192 if (pm == NULL || /* !cfg'ed */ 5193 pm->pm_state != PMC_STATE_RUNNING || /* !active */ 5194 !PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)) || /* !sampling */ 5195 !pm->pm_pcpu_state[cpu].pps_cpustate || /* !desired */ 5196 !pm->pm_pcpu_state[cpu].pps_stalled) /* !stalled */ 5197 continue; 5198 5199 pm->pm_pcpu_state[cpu].pps_stalled = 0; 5200 (void)(*pcd->pcd_start_pmc)(cpu, adjri, pm); 5201 } 5202 } 5203 5204 /* 5205 * Event handlers. 5206 */ 5207 5208 /* 5209 * Handle a process exit. 5210 * 5211 * Remove this process from all hash tables. If this process 5212 * owned any PMCs, turn off those PMCs and deallocate them, 5213 * removing any associations with target processes. 5214 * 5215 * This function will be called by the last 'thread' of a 5216 * process. 5217 * 5218 * XXX This eventhandler gets called early in the exit process. 5219 * Consider using a 'hook' invocation from thread_exit() or equivalent 5220 * spot. Another negative is that kse_exit doesn't seem to call 5221 * exit1() [??]. 5222 */ 5223 static void 5224 pmc_process_exit(void *arg __unused, struct proc *p) 5225 { 5226 struct pmc *pm; 5227 struct pmc_owner *po; 5228 struct pmc_process *pp; 5229 struct pmc_classdep *pcd; 5230 pmc_value_t newvalue, tmp; 5231 int ri, adjri, cpu; 5232 bool is_using_hwpmcs; 5233 5234 PROC_LOCK(p); 5235 is_using_hwpmcs = (p->p_flag & P_HWPMC) != 0; 5236 PROC_UNLOCK(p); 5237 5238 /* 5239 * Log a sysexit event to all SS PMC owners. 5240 */ 5241 PMC_EPOCH_ENTER(); 5242 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) { 5243 if ((po->po_flags & PMC_PO_OWNS_LOGFILE) != 0) 5244 pmclog_process_sysexit(po, p->p_pid); 5245 } 5246 PMC_EPOCH_EXIT(); 5247 5248 PMC_GET_SX_XLOCK(); 5249 PMCDBG3(PRC,EXT,1,"process-exit proc=%p (%d, %s)", p, p->p_pid, 5250 p->p_comm); 5251 5252 if (!is_using_hwpmcs) 5253 goto out; 5254 5255 /* 5256 * Since this code is invoked by the last thread in an exiting process, 5257 * we would have context switched IN at some prior point. However, with 5258 * PREEMPTION, kernel mode context switches may happen any time, so we 5259 * want to disable a context switch OUT till we get any PMCs targeting 5260 * this process off the hardware. 5261 * 5262 * We also need to atomically remove this process' entry from our 5263 * target process hash table, using PMC_FLAG_REMOVE. 5264 */ 5265 PMCDBG3(PRC,EXT,1, "process-exit proc=%p (%d, %s)", p, p->p_pid, 5266 p->p_comm); 5267 5268 critical_enter(); /* no preemption */ 5269 5270 cpu = curthread->td_oncpu; 5271 5272 pp = pmc_find_process_descriptor(p, PMC_FLAG_REMOVE); 5273 if (pp == NULL) { 5274 critical_exit(); 5275 goto out; 5276 } 5277 5278 PMCDBG2(PRC,EXT,2, "process-exit proc=%p pmc-process=%p", p, pp); 5279 5280 /* 5281 * The exiting process could be the target of some PMCs which will be 5282 * running on currently executing CPU. 5283 * 5284 * We need to turn these PMCs off like we would do at context switch 5285 * OUT time. 5286 */ 5287 for (ri = 0; ri < md->pmd_npmc; ri++) { 5288 /* 5289 * Pick up the pmc pointer from hardware state similar to the 5290 * CSW_OUT code. 5291 */ 5292 pm = NULL; 5293 pcd = pmc_ri_to_classdep(md, ri, &adjri); 5294 5295 (void)(*pcd->pcd_get_config)(cpu, adjri, &pm); 5296 5297 PMCDBG2(PRC,EXT,2, "ri=%d pm=%p", ri, pm); 5298 5299 if (pm == NULL || !PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) 5300 continue; 5301 5302 PMCDBG4(PRC,EXT,2, "ppmcs[%d]=%p pm=%p state=%d", ri, 5303 pp->pp_pmcs[ri].pp_pmc, pm, pm->pm_state); 5304 5305 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 5306 ("[pmc,%d] ri mismatch pmc(%d) ri(%d)", __LINE__, 5307 PMC_TO_ROWINDEX(pm), ri)); 5308 KASSERT(pm == pp->pp_pmcs[ri].pp_pmc, 5309 ("[pmc,%d] pm %p != pp_pmcs[%d] %p", __LINE__, pm, ri, 5310 pp->pp_pmcs[ri].pp_pmc)); 5311 KASSERT(counter_u64_fetch(pm->pm_runcount) > 0, 5312 ("[pmc,%d] bad runcount ri %d rc %ju", __LINE__, ri, 5313 (uintmax_t)counter_u64_fetch(pm->pm_runcount))); 5314 5315 /* 5316 * Change desired state, and then stop if not stalled. This 5317 * two-step dance should avoid race conditions where an 5318 * interrupt re-enables the PMC after this code has already 5319 * checked the pm_stalled flag. 5320 */ 5321 if (pm->pm_pcpu_state[cpu].pps_cpustate) { 5322 pm->pm_pcpu_state[cpu].pps_cpustate = 0; 5323 if (!pm->pm_pcpu_state[cpu].pps_stalled) { 5324 (void)pcd->pcd_stop_pmc(cpu, adjri, pm); 5325 5326 if (PMC_TO_MODE(pm) == PMC_MODE_TC) { 5327 pcd->pcd_read_pmc(cpu, adjri, pm, 5328 &newvalue); 5329 tmp = pmc_delta(pcd, newvalue, 5330 PMC_PCPU_SAVED(cpu, ri)); 5331 5332 mtx_pool_lock_spin(pmc_mtxpool, pm); 5333 pm->pm_gv.pm_savedvalue += tmp; 5334 pp->pp_pmcs[ri].pp_pmcval += tmp; 5335 mtx_pool_unlock_spin(pmc_mtxpool, pm); 5336 } 5337 } 5338 } 5339 5340 KASSERT(counter_u64_fetch(pm->pm_runcount) > 0, 5341 ("[pmc,%d] runcount is %d", __LINE__, ri)); 5342 5343 counter_u64_add(pm->pm_runcount, -1); 5344 (void)pcd->pcd_config_pmc(cpu, adjri, NULL); 5345 } 5346 5347 /* 5348 * Inform the MD layer of this pseudo "context switch out". 5349 */ 5350 (void)md->pmd_switch_out(pmc_pcpu[cpu], pp); 5351 5352 critical_exit(); /* ok to be pre-empted now */ 5353 5354 /* 5355 * Unlink this process from the PMCs that are targeting it. This will 5356 * send a signal to all PMC owner's whose PMCs are orphaned. 5357 * 5358 * Log PMC value at exit time if requested. 5359 */ 5360 for (ri = 0; ri < md->pmd_npmc; ri++) { 5361 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) { 5362 if ((pm->pm_flags & PMC_F_NEEDS_LOGFILE) != 0 && 5363 PMC_IS_COUNTING_MODE(PMC_TO_MODE(pm))) { 5364 pmclog_process_procexit(pm, pp); 5365 } 5366 pmc_unlink_target_process(pm, pp); 5367 } 5368 } 5369 free(pp, M_PMC); 5370 5371 out: 5372 /* 5373 * If the process owned PMCs, free them up and free up memory. 5374 */ 5375 if ((po = pmc_find_owner_descriptor(p)) != NULL) { 5376 if ((po->po_flags & PMC_PO_OWNS_LOGFILE) != 0) 5377 pmclog_close(po); 5378 pmc_remove_owner(po); 5379 pmc_destroy_owner_descriptor(po); 5380 } 5381 5382 sx_xunlock(&pmc_sx); 5383 } 5384 5385 /* 5386 * Handle a process fork. 5387 * 5388 * If the parent process 'p1' is under HWPMC monitoring, then copy 5389 * over any attached PMCs that have 'do_descendants' semantics. 5390 */ 5391 static void 5392 pmc_process_fork(void *arg __unused, struct proc *p1, struct proc *newproc, 5393 int flags __unused) 5394 { 5395 struct pmc *pm; 5396 struct pmc_owner *po; 5397 struct pmc_process *ppnew, *ppold; 5398 unsigned int ri; 5399 bool is_using_hwpmcs, do_descendants; 5400 5401 PROC_LOCK(p1); 5402 is_using_hwpmcs = (p1->p_flag & P_HWPMC) != 0; 5403 PROC_UNLOCK(p1); 5404 5405 /* 5406 * If there are system-wide sampling PMCs active, we need to 5407 * log all fork events to their owner's logs. 5408 */ 5409 PMC_EPOCH_ENTER(); 5410 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) { 5411 if (po->po_flags & PMC_PO_OWNS_LOGFILE) { 5412 pmclog_process_procfork(po, p1->p_pid, newproc->p_pid); 5413 pmclog_process_proccreate(po, newproc, 1); 5414 } 5415 } 5416 PMC_EPOCH_EXIT(); 5417 5418 if (!is_using_hwpmcs) 5419 return; 5420 5421 PMC_GET_SX_XLOCK(); 5422 PMCDBG4(PMC,FRK,1, "process-fork proc=%p (%d, %s) -> %p", p1, 5423 p1->p_pid, p1->p_comm, newproc); 5424 5425 /* 5426 * If the parent process (curthread->td_proc) is a 5427 * target of any PMCs, look for PMCs that are to be 5428 * inherited, and link these into the new process 5429 * descriptor. 5430 */ 5431 ppold = pmc_find_process_descriptor(curthread->td_proc, PMC_FLAG_NONE); 5432 if (ppold == NULL) 5433 goto done; /* nothing to do */ 5434 5435 do_descendants = false; 5436 for (ri = 0; ri < md->pmd_npmc; ri++) { 5437 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL && 5438 (pm->pm_flags & PMC_F_DESCENDANTS) != 0) { 5439 do_descendants = true; 5440 break; 5441 } 5442 } 5443 if (!do_descendants) /* nothing to do */ 5444 goto done; 5445 5446 /* 5447 * Now mark the new process as being tracked by this driver. 5448 */ 5449 PROC_LOCK(newproc); 5450 newproc->p_flag |= P_HWPMC; 5451 PROC_UNLOCK(newproc); 5452 5453 /* Allocate a descriptor for the new process. */ 5454 ppnew = pmc_find_process_descriptor(newproc, PMC_FLAG_ALLOCATE); 5455 if (ppnew == NULL) 5456 goto done; 5457 5458 /* 5459 * Run through all PMCs that were targeting the old process 5460 * and which specified F_DESCENDANTS and attach them to the 5461 * new process. 5462 * 5463 * Log the fork event to all owners of PMCs attached to this 5464 * process, if not already logged. 5465 */ 5466 for (ri = 0; ri < md->pmd_npmc; ri++) { 5467 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL && 5468 (pm->pm_flags & PMC_F_DESCENDANTS) != 0) { 5469 pmc_link_target_process(pm, ppnew); 5470 po = pm->pm_owner; 5471 if (po->po_sscount == 0 && 5472 (po->po_flags & PMC_PO_OWNS_LOGFILE) != 0) { 5473 pmclog_process_procfork(po, p1->p_pid, 5474 newproc->p_pid); 5475 } 5476 } 5477 } 5478 5479 done: 5480 sx_xunlock(&pmc_sx); 5481 } 5482 5483 static void 5484 pmc_process_threadcreate(struct thread *td) 5485 { 5486 struct pmc_owner *po; 5487 5488 PMC_EPOCH_ENTER(); 5489 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) { 5490 if ((po->po_flags & PMC_PO_OWNS_LOGFILE) != 0) 5491 pmclog_process_threadcreate(po, td, 1); 5492 } 5493 PMC_EPOCH_EXIT(); 5494 } 5495 5496 static void 5497 pmc_process_threadexit(struct thread *td) 5498 { 5499 struct pmc_owner *po; 5500 5501 PMC_EPOCH_ENTER(); 5502 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) { 5503 if ((po->po_flags & PMC_PO_OWNS_LOGFILE) != 0) 5504 pmclog_process_threadexit(po, td); 5505 } 5506 PMC_EPOCH_EXIT(); 5507 } 5508 5509 static void 5510 pmc_process_proccreate(struct proc *p) 5511 { 5512 struct pmc_owner *po; 5513 5514 PMC_EPOCH_ENTER(); 5515 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) { 5516 if ((po->po_flags & PMC_PO_OWNS_LOGFILE) != 0) 5517 pmclog_process_proccreate(po, p, 1 /* sync */); 5518 } 5519 PMC_EPOCH_EXIT(); 5520 } 5521 5522 static void 5523 pmc_process_allproc(struct pmc *pm) 5524 { 5525 struct pmc_owner *po; 5526 struct thread *td; 5527 struct proc *p; 5528 5529 po = pm->pm_owner; 5530 if ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) 5531 return; 5532 5533 sx_slock(&allproc_lock); 5534 FOREACH_PROC_IN_SYSTEM(p) { 5535 pmclog_process_proccreate(po, p, 0 /* sync */); 5536 PROC_LOCK(p); 5537 FOREACH_THREAD_IN_PROC(p, td) 5538 pmclog_process_threadcreate(po, td, 0 /* sync */); 5539 PROC_UNLOCK(p); 5540 } 5541 sx_sunlock(&allproc_lock); 5542 pmclog_flush(po, 0); 5543 } 5544 5545 static void 5546 pmc_kld_load(void *arg __unused, linker_file_t lf) 5547 { 5548 struct pmc_owner *po; 5549 5550 /* 5551 * Notify owners of system sampling PMCs about KLD operations. 5552 */ 5553 PMC_EPOCH_ENTER(); 5554 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) { 5555 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 5556 pmclog_process_map_in(po, (pid_t) -1, 5557 (uintfptr_t) lf->address, lf->pathname); 5558 } 5559 PMC_EPOCH_EXIT(); 5560 5561 /* 5562 * TODO: Notify owners of (all) process-sampling PMCs too. 5563 */ 5564 } 5565 5566 static void 5567 pmc_kld_unload(void *arg __unused, const char *filename __unused, 5568 caddr_t address, size_t size) 5569 { 5570 struct pmc_owner *po; 5571 5572 PMC_EPOCH_ENTER(); 5573 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) { 5574 if ((po->po_flags & PMC_PO_OWNS_LOGFILE) != 0) { 5575 pmclog_process_map_out(po, (pid_t)-1, 5576 (uintfptr_t)address, (uintfptr_t)address + size); 5577 } 5578 } 5579 PMC_EPOCH_EXIT(); 5580 5581 /* 5582 * TODO: Notify owners of process-sampling PMCs. 5583 */ 5584 } 5585 5586 /* 5587 * initialization 5588 */ 5589 static const char * 5590 pmc_name_of_pmcclass(enum pmc_class class) 5591 { 5592 5593 switch (class) { 5594 #undef __PMC_CLASS 5595 #define __PMC_CLASS(S,V,D) \ 5596 case PMC_CLASS_##S: \ 5597 return #S; 5598 __PMC_CLASSES(); 5599 default: 5600 return ("<unknown>"); 5601 } 5602 } 5603 5604 /* 5605 * Base class initializer: allocate structure and set default classes. 5606 */ 5607 struct pmc_mdep * 5608 pmc_mdep_alloc(int nclasses) 5609 { 5610 struct pmc_mdep *md; 5611 int n; 5612 5613 /* SOFT + md classes */ 5614 n = 1 + nclasses; 5615 md = malloc(sizeof(struct pmc_mdep) + n * sizeof(struct pmc_classdep), 5616 M_PMC, M_WAITOK | M_ZERO); 5617 md->pmd_nclass = n; 5618 5619 /* Default methods */ 5620 md->pmd_switch_in = generic_switch_in; 5621 md->pmd_switch_out = generic_switch_out; 5622 5623 /* Add base class. */ 5624 pmc_soft_initialize(md); 5625 return (md); 5626 } 5627 5628 void 5629 pmc_mdep_free(struct pmc_mdep *md) 5630 { 5631 pmc_soft_finalize(md); 5632 free(md, M_PMC); 5633 } 5634 5635 static int 5636 generic_switch_in(struct pmc_cpu *pc __unused, struct pmc_process *pp __unused) 5637 { 5638 5639 return (0); 5640 } 5641 5642 static int 5643 generic_switch_out(struct pmc_cpu *pc __unused, struct pmc_process *pp __unused) 5644 { 5645 5646 return (0); 5647 } 5648 5649 static struct pmc_mdep * 5650 pmc_generic_cpu_initialize(void) 5651 { 5652 struct pmc_mdep *md; 5653 5654 md = pmc_mdep_alloc(0); 5655 5656 md->pmd_cputype = PMC_CPU_GENERIC; 5657 5658 return (md); 5659 } 5660 5661 static void 5662 pmc_generic_cpu_finalize(struct pmc_mdep *md __unused) 5663 { 5664 5665 } 5666 5667 static int 5668 pmc_initialize(void) 5669 { 5670 struct pcpu *pc; 5671 struct pmc_binding pb; 5672 struct pmc_classdep *pcd; 5673 struct pmc_sample *ps; 5674 struct pmc_samplebuffer *sb; 5675 int c, cpu, error, n, ri; 5676 u_int maxcpu, domain; 5677 5678 md = NULL; 5679 error = 0; 5680 5681 pmc_stats.pm_intr_ignored = counter_u64_alloc(M_WAITOK); 5682 pmc_stats.pm_intr_processed = counter_u64_alloc(M_WAITOK); 5683 pmc_stats.pm_intr_bufferfull = counter_u64_alloc(M_WAITOK); 5684 pmc_stats.pm_syscalls = counter_u64_alloc(M_WAITOK); 5685 pmc_stats.pm_syscall_errors = counter_u64_alloc(M_WAITOK); 5686 pmc_stats.pm_buffer_requests = counter_u64_alloc(M_WAITOK); 5687 pmc_stats.pm_buffer_requests_failed = counter_u64_alloc(M_WAITOK); 5688 pmc_stats.pm_log_sweeps = counter_u64_alloc(M_WAITOK); 5689 pmc_stats.pm_merges = counter_u64_alloc(M_WAITOK); 5690 pmc_stats.pm_overwrites = counter_u64_alloc(M_WAITOK); 5691 5692 #ifdef HWPMC_DEBUG 5693 /* parse debug flags first */ 5694 if (TUNABLE_STR_FETCH(PMC_SYSCTL_NAME_PREFIX "debugflags", 5695 pmc_debugstr, sizeof(pmc_debugstr))) { 5696 pmc_debugflags_parse(pmc_debugstr, pmc_debugstr + 5697 strlen(pmc_debugstr)); 5698 } 5699 #endif 5700 5701 PMCDBG1(MOD,INI,0, "PMC Initialize (version %x)", PMC_VERSION); 5702 5703 /* check kernel version */ 5704 if (pmc_kernel_version != PMC_VERSION) { 5705 if (pmc_kernel_version == 0) 5706 printf("hwpmc: this kernel has not been compiled with " 5707 "'options HWPMC_HOOKS'.\n"); 5708 else 5709 printf("hwpmc: kernel version (0x%x) does not match " 5710 "module version (0x%x).\n", pmc_kernel_version, 5711 PMC_VERSION); 5712 return (EPROGMISMATCH); 5713 } 5714 5715 /* 5716 * check sysctl parameters 5717 */ 5718 if (pmc_hashsize <= 0) { 5719 printf("hwpmc: tunable \"hashsize\"=%d must be " 5720 "greater than zero.\n", pmc_hashsize); 5721 pmc_hashsize = PMC_HASH_SIZE; 5722 } 5723 5724 if (pmc_nsamples <= 0 || pmc_nsamples > 65535) { 5725 printf("hwpmc: tunable \"nsamples\"=%d out of " 5726 "range.\n", pmc_nsamples); 5727 pmc_nsamples = PMC_NSAMPLES; 5728 } 5729 pmc_sample_mask = pmc_nsamples - 1; 5730 5731 if (pmc_callchaindepth <= 0 || 5732 pmc_callchaindepth > PMC_CALLCHAIN_DEPTH_MAX) { 5733 printf("hwpmc: tunable \"callchaindepth\"=%d out of " 5734 "range - using %d.\n", pmc_callchaindepth, 5735 PMC_CALLCHAIN_DEPTH_MAX); 5736 pmc_callchaindepth = PMC_CALLCHAIN_DEPTH_MAX; 5737 } 5738 5739 md = pmc_md_initialize(); 5740 if (md == NULL) { 5741 /* Default to generic CPU. */ 5742 md = pmc_generic_cpu_initialize(); 5743 if (md == NULL) 5744 return (ENOSYS); 5745 } 5746 5747 /* 5748 * Refresh classes base ri. Optional classes may come in different 5749 * order. 5750 */ 5751 for (ri = c = 0; c < md->pmd_nclass; c++) { 5752 pcd = &md->pmd_classdep[c]; 5753 pcd->pcd_ri = ri; 5754 ri += pcd->pcd_num; 5755 } 5756 5757 KASSERT(md->pmd_nclass >= 1 && md->pmd_npmc >= 1, 5758 ("[pmc,%d] no classes or pmcs", __LINE__)); 5759 5760 /* Compute the map from row-indices to classdep pointers. */ 5761 pmc_rowindex_to_classdep = malloc(sizeof(struct pmc_classdep *) * 5762 md->pmd_npmc, M_PMC, M_WAITOK | M_ZERO); 5763 5764 for (n = 0; n < md->pmd_npmc; n++) 5765 pmc_rowindex_to_classdep[n] = NULL; 5766 5767 for (ri = c = 0; c < md->pmd_nclass; c++) { 5768 pcd = &md->pmd_classdep[c]; 5769 for (n = 0; n < pcd->pcd_num; n++, ri++) 5770 pmc_rowindex_to_classdep[ri] = pcd; 5771 } 5772 5773 KASSERT(ri == md->pmd_npmc, 5774 ("[pmc,%d] npmc miscomputed: ri=%d, md->npmc=%d", __LINE__, 5775 ri, md->pmd_npmc)); 5776 5777 maxcpu = pmc_cpu_max(); 5778 5779 /* allocate space for the per-cpu array */ 5780 pmc_pcpu = malloc(maxcpu * sizeof(struct pmc_cpu *), M_PMC, 5781 M_WAITOK | M_ZERO); 5782 5783 /* per-cpu 'saved values' for managing process-mode PMCs */ 5784 pmc_pcpu_saved = malloc(sizeof(pmc_value_t) * maxcpu * md->pmd_npmc, 5785 M_PMC, M_WAITOK); 5786 5787 /* Perform CPU-dependent initialization. */ 5788 pmc_save_cpu_binding(&pb); 5789 error = 0; 5790 for (cpu = 0; error == 0 && cpu < maxcpu; cpu++) { 5791 if (!pmc_cpu_is_active(cpu)) 5792 continue; 5793 pmc_select_cpu(cpu); 5794 pmc_pcpu[cpu] = malloc(sizeof(struct pmc_cpu) + 5795 md->pmd_npmc * sizeof(struct pmc_hw *), M_PMC, 5796 M_WAITOK | M_ZERO); 5797 for (n = 0; error == 0 && n < md->pmd_nclass; n++) 5798 if (md->pmd_classdep[n].pcd_num > 0) 5799 error = md->pmd_classdep[n].pcd_pcpu_init(md, 5800 cpu); 5801 } 5802 pmc_restore_cpu_binding(&pb); 5803 5804 if (error != 0) 5805 return (error); 5806 5807 /* allocate space for the sample array */ 5808 for (cpu = 0; cpu < maxcpu; cpu++) { 5809 if (!pmc_cpu_is_active(cpu)) 5810 continue; 5811 pc = pcpu_find(cpu); 5812 domain = pc->pc_domain; 5813 sb = malloc_domainset(sizeof(struct pmc_samplebuffer) + 5814 pmc_nsamples * sizeof(struct pmc_sample), M_PMC, 5815 DOMAINSET_PREF(domain), M_WAITOK | M_ZERO); 5816 5817 KASSERT(pmc_pcpu[cpu] != NULL, 5818 ("[pmc,%d] cpu=%d Null per-cpu data", __LINE__, cpu)); 5819 5820 sb->ps_callchains = malloc_domainset(pmc_callchaindepth * 5821 pmc_nsamples * sizeof(uintptr_t), M_PMC, 5822 DOMAINSET_PREF(domain), M_WAITOK | M_ZERO); 5823 5824 for (n = 0, ps = sb->ps_samples; n < pmc_nsamples; n++, ps++) 5825 ps->ps_pc = sb->ps_callchains + 5826 (n * pmc_callchaindepth); 5827 5828 pmc_pcpu[cpu]->pc_sb[PMC_HR] = sb; 5829 5830 sb = malloc_domainset(sizeof(struct pmc_samplebuffer) + 5831 pmc_nsamples * sizeof(struct pmc_sample), M_PMC, 5832 DOMAINSET_PREF(domain), M_WAITOK | M_ZERO); 5833 5834 sb->ps_callchains = malloc_domainset(pmc_callchaindepth * 5835 pmc_nsamples * sizeof(uintptr_t), M_PMC, 5836 DOMAINSET_PREF(domain), M_WAITOK | M_ZERO); 5837 for (n = 0, ps = sb->ps_samples; n < pmc_nsamples; n++, ps++) 5838 ps->ps_pc = sb->ps_callchains + 5839 (n * pmc_callchaindepth); 5840 5841 pmc_pcpu[cpu]->pc_sb[PMC_SR] = sb; 5842 5843 sb = malloc_domainset(sizeof(struct pmc_samplebuffer) + 5844 pmc_nsamples * sizeof(struct pmc_sample), M_PMC, 5845 DOMAINSET_PREF(domain), M_WAITOK | M_ZERO); 5846 sb->ps_callchains = malloc_domainset(pmc_callchaindepth * 5847 pmc_nsamples * sizeof(uintptr_t), M_PMC, 5848 DOMAINSET_PREF(domain), M_WAITOK | M_ZERO); 5849 for (n = 0, ps = sb->ps_samples; n < pmc_nsamples; n++, ps++) 5850 ps->ps_pc = sb->ps_callchains + n * pmc_callchaindepth; 5851 5852 pmc_pcpu[cpu]->pc_sb[PMC_UR] = sb; 5853 } 5854 5855 /* allocate space for the row disposition array */ 5856 pmc_pmcdisp = malloc(sizeof(enum pmc_mode) * md->pmd_npmc, 5857 M_PMC, M_WAITOK | M_ZERO); 5858 5859 /* mark all PMCs as available */ 5860 for (n = 0; n < md->pmd_npmc; n++) 5861 PMC_MARK_ROW_FREE(n); 5862 5863 /* allocate thread hash tables */ 5864 pmc_ownerhash = hashinit(pmc_hashsize, M_PMC, 5865 &pmc_ownerhashmask); 5866 5867 pmc_processhash = hashinit(pmc_hashsize, M_PMC, 5868 &pmc_processhashmask); 5869 mtx_init(&pmc_processhash_mtx, "pmc-process-hash", "pmc-leaf", 5870 MTX_SPIN); 5871 5872 CK_LIST_INIT(&pmc_ss_owners); 5873 pmc_ss_count = 0; 5874 5875 /* allocate a pool of spin mutexes */ 5876 pmc_mtxpool = mtx_pool_create("pmc-leaf", pmc_mtxpool_size, 5877 MTX_SPIN); 5878 5879 PMCDBG4(MOD,INI,1, "pmc_ownerhash=%p, mask=0x%lx " 5880 "targethash=%p mask=0x%lx", pmc_ownerhash, pmc_ownerhashmask, 5881 pmc_processhash, pmc_processhashmask); 5882 5883 /* Initialize a spin mutex for the thread free list. */ 5884 mtx_init(&pmc_threadfreelist_mtx, "pmc-threadfreelist", "pmc-leaf", 5885 MTX_SPIN); 5886 5887 /* Initialize the task to prune the thread free list. */ 5888 TASK_INIT(&free_task, 0, pmc_thread_descriptor_pool_free_task, NULL); 5889 5890 /* register process {exit,fork,exec} handlers */ 5891 pmc_exit_tag = EVENTHANDLER_REGISTER(process_exit, 5892 pmc_process_exit, NULL, EVENTHANDLER_PRI_ANY); 5893 pmc_fork_tag = EVENTHANDLER_REGISTER(process_fork, 5894 pmc_process_fork, NULL, EVENTHANDLER_PRI_ANY); 5895 5896 /* register kld event handlers */ 5897 pmc_kld_load_tag = EVENTHANDLER_REGISTER(kld_load, pmc_kld_load, 5898 NULL, EVENTHANDLER_PRI_ANY); 5899 pmc_kld_unload_tag = EVENTHANDLER_REGISTER(kld_unload, pmc_kld_unload, 5900 NULL, EVENTHANDLER_PRI_ANY); 5901 5902 /* initialize logging */ 5903 pmclog_initialize(); 5904 5905 /* set hook functions */ 5906 pmc_intr = md->pmd_intr; 5907 wmb(); 5908 pmc_hook = pmc_hook_handler; 5909 5910 if (error == 0) { 5911 printf(PMC_MODULE_NAME ":"); 5912 for (n = 0; n < md->pmd_nclass; n++) { 5913 if (md->pmd_classdep[n].pcd_num == 0) 5914 continue; 5915 pcd = &md->pmd_classdep[n]; 5916 printf(" %s/%d/%d/0x%b", 5917 pmc_name_of_pmcclass(pcd->pcd_class), 5918 pcd->pcd_num, 5919 pcd->pcd_width, 5920 pcd->pcd_caps, 5921 "\20" 5922 "\1INT\2USR\3SYS\4EDG\5THR" 5923 "\6REA\7WRI\10INV\11QUA\12PRC" 5924 "\13TAG\14CSC"); 5925 } 5926 printf("\n"); 5927 } 5928 5929 return (error); 5930 } 5931 5932 /* prepare to be unloaded */ 5933 static void 5934 pmc_cleanup(void) 5935 { 5936 struct pmc_binding pb; 5937 struct pmc_owner *po, *tmp; 5938 struct pmc_ownerhash *ph; 5939 struct pmc_processhash *prh __pmcdbg_used; 5940 u_int maxcpu; 5941 int cpu, c; 5942 5943 PMCDBG0(MOD,INI,0, "cleanup"); 5944 5945 /* switch off sampling */ 5946 CPU_FOREACH(cpu) 5947 DPCPU_ID_SET(cpu, pmc_sampled, 0); 5948 pmc_intr = NULL; 5949 5950 sx_xlock(&pmc_sx); 5951 if (pmc_hook == NULL) { /* being unloaded already */ 5952 sx_xunlock(&pmc_sx); 5953 return; 5954 } 5955 5956 pmc_hook = NULL; /* prevent new threads from entering module */ 5957 5958 /* deregister event handlers */ 5959 EVENTHANDLER_DEREGISTER(process_fork, pmc_fork_tag); 5960 EVENTHANDLER_DEREGISTER(process_exit, pmc_exit_tag); 5961 EVENTHANDLER_DEREGISTER(kld_load, pmc_kld_load_tag); 5962 EVENTHANDLER_DEREGISTER(kld_unload, pmc_kld_unload_tag); 5963 5964 /* send SIGBUS to all owner threads, free up allocations */ 5965 if (pmc_ownerhash != NULL) { 5966 for (ph = pmc_ownerhash; 5967 ph <= &pmc_ownerhash[pmc_ownerhashmask]; 5968 ph++) { 5969 LIST_FOREACH_SAFE(po, ph, po_next, tmp) { 5970 pmc_remove_owner(po); 5971 5972 PMCDBG3(MOD,INI,2, 5973 "cleanup signal proc=%p (%d, %s)", 5974 po->po_owner, po->po_owner->p_pid, 5975 po->po_owner->p_comm); 5976 5977 PROC_LOCK(po->po_owner); 5978 kern_psignal(po->po_owner, SIGBUS); 5979 PROC_UNLOCK(po->po_owner); 5980 5981 pmc_destroy_owner_descriptor(po); 5982 } 5983 } 5984 } 5985 5986 /* reclaim allocated data structures */ 5987 taskqueue_drain(taskqueue_fast, &free_task); 5988 mtx_destroy(&pmc_threadfreelist_mtx); 5989 pmc_thread_descriptor_pool_drain(); 5990 5991 if (pmc_mtxpool != NULL) 5992 mtx_pool_destroy(&pmc_mtxpool); 5993 5994 mtx_destroy(&pmc_processhash_mtx); 5995 if (pmc_processhash != NULL) { 5996 #ifdef HWPMC_DEBUG 5997 struct pmc_process *pp; 5998 5999 PMCDBG0(MOD,INI,3, "destroy process hash"); 6000 for (prh = pmc_processhash; 6001 prh <= &pmc_processhash[pmc_processhashmask]; 6002 prh++) 6003 LIST_FOREACH(pp, prh, pp_next) 6004 PMCDBG1(MOD,INI,3, "pid=%d", pp->pp_proc->p_pid); 6005 #endif 6006 6007 hashdestroy(pmc_processhash, M_PMC, pmc_processhashmask); 6008 pmc_processhash = NULL; 6009 } 6010 6011 if (pmc_ownerhash != NULL) { 6012 PMCDBG0(MOD,INI,3, "destroy owner hash"); 6013 hashdestroy(pmc_ownerhash, M_PMC, pmc_ownerhashmask); 6014 pmc_ownerhash = NULL; 6015 } 6016 6017 KASSERT(CK_LIST_EMPTY(&pmc_ss_owners), 6018 ("[pmc,%d] Global SS owner list not empty", __LINE__)); 6019 KASSERT(pmc_ss_count == 0, 6020 ("[pmc,%d] Global SS count not empty", __LINE__)); 6021 6022 /* do processor and pmc-class dependent cleanup */ 6023 maxcpu = pmc_cpu_max(); 6024 6025 PMCDBG0(MOD,INI,3, "md cleanup"); 6026 if (md) { 6027 pmc_save_cpu_binding(&pb); 6028 for (cpu = 0; cpu < maxcpu; cpu++) { 6029 PMCDBG2(MOD,INI,1,"pmc-cleanup cpu=%d pcs=%p", 6030 cpu, pmc_pcpu[cpu]); 6031 if (!pmc_cpu_is_active(cpu) || pmc_pcpu[cpu] == NULL) 6032 continue; 6033 6034 pmc_select_cpu(cpu); 6035 for (c = 0; c < md->pmd_nclass; c++) { 6036 if (md->pmd_classdep[c].pcd_num > 0) { 6037 md->pmd_classdep[c].pcd_pcpu_fini(md, 6038 cpu); 6039 } 6040 } 6041 } 6042 6043 if (md->pmd_cputype == PMC_CPU_GENERIC) 6044 pmc_generic_cpu_finalize(md); 6045 else 6046 pmc_md_finalize(md); 6047 6048 pmc_mdep_free(md); 6049 md = NULL; 6050 pmc_restore_cpu_binding(&pb); 6051 } 6052 6053 /* Free per-cpu descriptors. */ 6054 for (cpu = 0; cpu < maxcpu; cpu++) { 6055 if (!pmc_cpu_is_active(cpu)) 6056 continue; 6057 KASSERT(pmc_pcpu[cpu]->pc_sb[PMC_HR] != NULL, 6058 ("[pmc,%d] Null hw cpu sample buffer cpu=%d", __LINE__, 6059 cpu)); 6060 KASSERT(pmc_pcpu[cpu]->pc_sb[PMC_SR] != NULL, 6061 ("[pmc,%d] Null sw cpu sample buffer cpu=%d", __LINE__, 6062 cpu)); 6063 KASSERT(pmc_pcpu[cpu]->pc_sb[PMC_UR] != NULL, 6064 ("[pmc,%d] Null userret cpu sample buffer cpu=%d", __LINE__, 6065 cpu)); 6066 free(pmc_pcpu[cpu]->pc_sb[PMC_HR]->ps_callchains, M_PMC); 6067 free(pmc_pcpu[cpu]->pc_sb[PMC_HR], M_PMC); 6068 free(pmc_pcpu[cpu]->pc_sb[PMC_SR]->ps_callchains, M_PMC); 6069 free(pmc_pcpu[cpu]->pc_sb[PMC_SR], M_PMC); 6070 free(pmc_pcpu[cpu]->pc_sb[PMC_UR]->ps_callchains, M_PMC); 6071 free(pmc_pcpu[cpu]->pc_sb[PMC_UR], M_PMC); 6072 free(pmc_pcpu[cpu], M_PMC); 6073 } 6074 6075 free(pmc_pcpu, M_PMC); 6076 pmc_pcpu = NULL; 6077 6078 free(pmc_pcpu_saved, M_PMC); 6079 pmc_pcpu_saved = NULL; 6080 6081 if (pmc_pmcdisp != NULL) { 6082 free(pmc_pmcdisp, M_PMC); 6083 pmc_pmcdisp = NULL; 6084 } 6085 6086 if (pmc_rowindex_to_classdep != NULL) { 6087 free(pmc_rowindex_to_classdep, M_PMC); 6088 pmc_rowindex_to_classdep = NULL; 6089 } 6090 6091 pmclog_shutdown(); 6092 counter_u64_free(pmc_stats.pm_intr_ignored); 6093 counter_u64_free(pmc_stats.pm_intr_processed); 6094 counter_u64_free(pmc_stats.pm_intr_bufferfull); 6095 counter_u64_free(pmc_stats.pm_syscalls); 6096 counter_u64_free(pmc_stats.pm_syscall_errors); 6097 counter_u64_free(pmc_stats.pm_buffer_requests); 6098 counter_u64_free(pmc_stats.pm_buffer_requests_failed); 6099 counter_u64_free(pmc_stats.pm_log_sweeps); 6100 counter_u64_free(pmc_stats.pm_merges); 6101 counter_u64_free(pmc_stats.pm_overwrites); 6102 sx_xunlock(&pmc_sx); /* we are done */ 6103 } 6104 6105 /* 6106 * The function called at load/unload. 6107 */ 6108 static int 6109 load(struct module *module __unused, int cmd, void *arg __unused) 6110 { 6111 int error; 6112 6113 error = 0; 6114 6115 switch (cmd) { 6116 case MOD_LOAD: 6117 /* initialize the subsystem */ 6118 error = pmc_initialize(); 6119 if (error != 0) 6120 break; 6121 PMCDBG2(MOD,INI,1, "syscall=%d maxcpu=%d", pmc_syscall_num, 6122 pmc_cpu_max()); 6123 break; 6124 case MOD_UNLOAD: 6125 case MOD_SHUTDOWN: 6126 pmc_cleanup(); 6127 PMCDBG0(MOD,INI,1, "unloaded"); 6128 break; 6129 default: 6130 error = EINVAL; 6131 break; 6132 } 6133 6134 return (error); 6135 } 6136