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 35 #include <sys/cdefs.h> 36 __FBSDID("$FreeBSD$"); 37 38 #include <sys/param.h> 39 #include <sys/systm.h> 40 #include <sys/domainset.h> 41 #include <sys/eventhandler.h> 42 #include <sys/jail.h> 43 #include <sys/kernel.h> 44 #include <sys/kthread.h> 45 #include <sys/limits.h> 46 #include <sys/lock.h> 47 #include <sys/malloc.h> 48 #include <sys/module.h> 49 #include <sys/mount.h> 50 #include <sys/mutex.h> 51 #include <sys/pmc.h> 52 #include <sys/pmckern.h> 53 #include <sys/pmclog.h> 54 #include <sys/priv.h> 55 #include <sys/proc.h> 56 #include <sys/queue.h> 57 #include <sys/resourcevar.h> 58 #include <sys/rwlock.h> 59 #include <sys/sched.h> 60 #include <sys/signalvar.h> 61 #include <sys/smp.h> 62 #include <sys/sx.h> 63 #include <sys/sysctl.h> 64 #include <sys/sysent.h> 65 #include <sys/syslog.h> 66 #include <sys/taskqueue.h> 67 #include <sys/vnode.h> 68 69 #include <sys/linker.h> /* needs to be after <sys/malloc.h> */ 70 71 #include <machine/atomic.h> 72 #include <machine/md_var.h> 73 74 #include <vm/vm.h> 75 #include <vm/vm_extern.h> 76 #include <vm/pmap.h> 77 #include <vm/vm_map.h> 78 #include <vm/vm_object.h> 79 80 #include "hwpmc_soft.h" 81 82 #define PMC_EPOCH_ENTER() struct epoch_tracker pmc_et; epoch_enter_preempt(global_epoch_preempt, &pmc_et) 83 #define PMC_EPOCH_EXIT() epoch_exit_preempt(global_epoch_preempt, &pmc_et) 84 85 /* 86 * Types 87 */ 88 89 enum pmc_flags { 90 PMC_FLAG_NONE = 0x00, /* do nothing */ 91 PMC_FLAG_REMOVE = 0x01, /* atomically remove entry from hash */ 92 PMC_FLAG_ALLOCATE = 0x02, /* add entry to hash if not found */ 93 PMC_FLAG_NOWAIT = 0x04, /* do not wait for mallocs */ 94 }; 95 96 /* 97 * The offset in sysent where the syscall is allocated. 98 */ 99 100 static int pmc_syscall_num = NO_SYSCALL; 101 struct pmc_cpu **pmc_pcpu; /* per-cpu state */ 102 pmc_value_t *pmc_pcpu_saved; /* saved PMC values: CSW handling */ 103 104 #define PMC_PCPU_SAVED(C,R) pmc_pcpu_saved[(R) + md->pmd_npmc*(C)] 105 106 struct mtx_pool *pmc_mtxpool; 107 static int *pmc_pmcdisp; /* PMC row dispositions */ 108 109 #define PMC_ROW_DISP_IS_FREE(R) (pmc_pmcdisp[(R)] == 0) 110 #define PMC_ROW_DISP_IS_THREAD(R) (pmc_pmcdisp[(R)] > 0) 111 #define PMC_ROW_DISP_IS_STANDALONE(R) (pmc_pmcdisp[(R)] < 0) 112 113 #define PMC_MARK_ROW_FREE(R) do { \ 114 pmc_pmcdisp[(R)] = 0; \ 115 } while (0) 116 117 #define PMC_MARK_ROW_STANDALONE(R) do { \ 118 KASSERT(pmc_pmcdisp[(R)] <= 0, ("[pmc,%d] row disposition error", \ 119 __LINE__)); \ 120 atomic_add_int(&pmc_pmcdisp[(R)], -1); \ 121 KASSERT(pmc_pmcdisp[(R)] >= (-pmc_cpu_max_active()), \ 122 ("[pmc,%d] row disposition error", __LINE__)); \ 123 } while (0) 124 125 #define PMC_UNMARK_ROW_STANDALONE(R) do { \ 126 atomic_add_int(&pmc_pmcdisp[(R)], 1); \ 127 KASSERT(pmc_pmcdisp[(R)] <= 0, ("[pmc,%d] row disposition error", \ 128 __LINE__)); \ 129 } while (0) 130 131 #define PMC_MARK_ROW_THREAD(R) do { \ 132 KASSERT(pmc_pmcdisp[(R)] >= 0, ("[pmc,%d] row disposition error", \ 133 __LINE__)); \ 134 atomic_add_int(&pmc_pmcdisp[(R)], 1); \ 135 } while (0) 136 137 #define PMC_UNMARK_ROW_THREAD(R) do { \ 138 atomic_add_int(&pmc_pmcdisp[(R)], -1); \ 139 KASSERT(pmc_pmcdisp[(R)] >= 0, ("[pmc,%d] row disposition error", \ 140 __LINE__)); \ 141 } while (0) 142 143 144 /* various event handlers */ 145 static eventhandler_tag pmc_exit_tag, pmc_fork_tag, pmc_kld_load_tag, 146 pmc_kld_unload_tag; 147 148 /* Module statistics */ 149 struct pmc_driverstats pmc_stats; 150 151 152 /* Machine/processor dependent operations */ 153 static struct pmc_mdep *md; 154 155 /* 156 * Hash tables mapping owner processes and target threads to PMCs. 157 */ 158 159 struct mtx pmc_processhash_mtx; /* spin mutex */ 160 static u_long pmc_processhashmask; 161 static LIST_HEAD(pmc_processhash, pmc_process) *pmc_processhash; 162 163 /* 164 * Hash table of PMC owner descriptors. This table is protected by 165 * the shared PMC "sx" lock. 166 */ 167 168 static u_long pmc_ownerhashmask; 169 static LIST_HEAD(pmc_ownerhash, pmc_owner) *pmc_ownerhash; 170 171 /* 172 * List of PMC owners with system-wide sampling PMCs. 173 */ 174 175 static CK_LIST_HEAD(, pmc_owner) pmc_ss_owners; 176 177 /* 178 * List of free thread entries. This is protected by the spin 179 * mutex. 180 */ 181 static struct mtx pmc_threadfreelist_mtx; /* spin mutex */ 182 static LIST_HEAD(, pmc_thread) pmc_threadfreelist; 183 static int pmc_threadfreelist_entries=0; 184 #define THREADENTRY_SIZE \ 185 (sizeof(struct pmc_thread) + (md->pmd_npmc * sizeof(struct pmc_threadpmcstate))) 186 187 /* 188 * Task to free thread descriptors 189 */ 190 static struct task free_task; 191 192 /* 193 * A map of row indices to classdep structures. 194 */ 195 static struct pmc_classdep **pmc_rowindex_to_classdep; 196 197 /* 198 * Prototypes 199 */ 200 201 #ifdef HWPMC_DEBUG 202 static int pmc_debugflags_sysctl_handler(SYSCTL_HANDLER_ARGS); 203 static int pmc_debugflags_parse(char *newstr, char *fence); 204 #endif 205 206 static int load(struct module *module, int cmd, void *arg); 207 static int pmc_add_sample(ring_type_t ring, struct pmc *pm, struct trapframe *tf); 208 static void pmc_add_thread_descriptors_from_proc(struct proc *p, 209 struct pmc_process *pp); 210 static int pmc_attach_process(struct proc *p, struct pmc *pm); 211 static struct pmc *pmc_allocate_pmc_descriptor(void); 212 static struct pmc_owner *pmc_allocate_owner_descriptor(struct proc *p); 213 static int pmc_attach_one_process(struct proc *p, struct pmc *pm); 214 static int pmc_can_allocate_rowindex(struct proc *p, unsigned int ri, 215 int cpu); 216 static int pmc_can_attach(struct pmc *pm, struct proc *p); 217 static void pmc_capture_user_callchain(int cpu, int soft, struct trapframe *tf); 218 static void pmc_cleanup(void); 219 static int pmc_detach_process(struct proc *p, struct pmc *pm); 220 static int pmc_detach_one_process(struct proc *p, struct pmc *pm, 221 int flags); 222 static void pmc_destroy_owner_descriptor(struct pmc_owner *po); 223 static void pmc_destroy_pmc_descriptor(struct pmc *pm); 224 static void pmc_destroy_process_descriptor(struct pmc_process *pp); 225 static struct pmc_owner *pmc_find_owner_descriptor(struct proc *p); 226 static int pmc_find_pmc(pmc_id_t pmcid, struct pmc **pm); 227 static struct pmc *pmc_find_pmc_descriptor_in_process(struct pmc_owner *po, 228 pmc_id_t pmc); 229 static struct pmc_process *pmc_find_process_descriptor(struct proc *p, 230 uint32_t mode); 231 static struct pmc_thread *pmc_find_thread_descriptor(struct pmc_process *pp, 232 struct thread *td, uint32_t mode); 233 static void pmc_force_context_switch(void); 234 static void pmc_link_target_process(struct pmc *pm, 235 struct pmc_process *pp); 236 static void pmc_log_all_process_mappings(struct pmc_owner *po); 237 static void pmc_log_kernel_mappings(struct pmc *pm); 238 static void pmc_log_process_mappings(struct pmc_owner *po, struct proc *p); 239 static void pmc_maybe_remove_owner(struct pmc_owner *po); 240 static void pmc_process_csw_in(struct thread *td); 241 static void pmc_process_csw_out(struct thread *td); 242 static void pmc_process_exit(void *arg, struct proc *p); 243 static void pmc_process_fork(void *arg, struct proc *p1, 244 struct proc *p2, int n); 245 static void pmc_process_samples(int cpu, ring_type_t soft); 246 static void pmc_release_pmc_descriptor(struct pmc *pmc); 247 static void pmc_process_thread_add(struct thread *td); 248 static void pmc_process_thread_delete(struct thread *td); 249 static void pmc_process_thread_userret(struct thread *td); 250 static void pmc_remove_owner(struct pmc_owner *po); 251 static void pmc_remove_process_descriptor(struct pmc_process *pp); 252 static int pmc_start(struct pmc *pm); 253 static int pmc_stop(struct pmc *pm); 254 static int pmc_syscall_handler(struct thread *td, void *syscall_args); 255 static struct pmc_thread *pmc_thread_descriptor_pool_alloc(void); 256 static void pmc_thread_descriptor_pool_drain(void); 257 static void pmc_thread_descriptor_pool_free(struct pmc_thread *pt); 258 static void pmc_unlink_target_process(struct pmc *pmc, 259 struct pmc_process *pp); 260 static int generic_switch_in(struct pmc_cpu *pc, struct pmc_process *pp); 261 static int generic_switch_out(struct pmc_cpu *pc, struct pmc_process *pp); 262 static struct pmc_mdep *pmc_generic_cpu_initialize(void); 263 static void pmc_generic_cpu_finalize(struct pmc_mdep *md); 264 static void pmc_post_callchain_callback(void); 265 static void pmc_process_threadcreate(struct thread *td); 266 static void pmc_process_threadexit(struct thread *td); 267 static void pmc_process_proccreate(struct proc *p); 268 static void pmc_process_allproc(struct pmc *pm); 269 270 /* 271 * Kernel tunables and sysctl(8) interface. 272 */ 273 274 SYSCTL_DECL(_kern_hwpmc); 275 SYSCTL_NODE(_kern_hwpmc, OID_AUTO, stats, CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 276 "HWPMC stats"); 277 278 279 /* Stats. */ 280 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, intr_ignored, CTLFLAG_RW, 281 &pmc_stats.pm_intr_ignored, "# of interrupts ignored"); 282 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, intr_processed, CTLFLAG_RW, 283 &pmc_stats.pm_intr_processed, "# of interrupts processed"); 284 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, intr_bufferfull, CTLFLAG_RW, 285 &pmc_stats.pm_intr_bufferfull, "# of interrupts where buffer was full"); 286 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, syscalls, CTLFLAG_RW, 287 &pmc_stats.pm_syscalls, "# of syscalls"); 288 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, syscall_errors, CTLFLAG_RW, 289 &pmc_stats.pm_syscall_errors, "# of syscall_errors"); 290 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, buffer_requests, CTLFLAG_RW, 291 &pmc_stats.pm_buffer_requests, "# of buffer requests"); 292 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, buffer_requests_failed, CTLFLAG_RW, 293 &pmc_stats.pm_buffer_requests_failed, "# of buffer requests which failed"); 294 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, log_sweeps, CTLFLAG_RW, 295 &pmc_stats.pm_log_sweeps, "# of times samples were processed"); 296 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, merges, CTLFLAG_RW, 297 &pmc_stats.pm_merges, "# of times kernel stack was found for user trace"); 298 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, overwrites, CTLFLAG_RW, 299 &pmc_stats.pm_overwrites, "# of times a sample was overwritten before being logged"); 300 301 static int pmc_callchaindepth = PMC_CALLCHAIN_DEPTH; 302 SYSCTL_INT(_kern_hwpmc, OID_AUTO, callchaindepth, CTLFLAG_RDTUN, 303 &pmc_callchaindepth, 0, "depth of call chain records"); 304 305 char pmc_cpuid[PMC_CPUID_LEN]; 306 SYSCTL_STRING(_kern_hwpmc, OID_AUTO, cpuid, CTLFLAG_RD, 307 pmc_cpuid, 0, "cpu version string"); 308 #ifdef HWPMC_DEBUG 309 struct pmc_debugflags pmc_debugflags = PMC_DEBUG_DEFAULT_FLAGS; 310 char pmc_debugstr[PMC_DEBUG_STRSIZE]; 311 TUNABLE_STR(PMC_SYSCTL_NAME_PREFIX "debugflags", pmc_debugstr, 312 sizeof(pmc_debugstr)); 313 SYSCTL_PROC(_kern_hwpmc, OID_AUTO, debugflags, 314 CTLTYPE_STRING | CTLFLAG_RWTUN | CTLFLAG_NOFETCH | CTLFLAG_MPSAFE, 315 0, 0, pmc_debugflags_sysctl_handler, "A", 316 "debug flags"); 317 #endif 318 319 320 /* 321 * kern.hwpmc.hashrows -- determines the number of rows in the 322 * of the hash table used to look up threads 323 */ 324 325 static int pmc_hashsize = PMC_HASH_SIZE; 326 SYSCTL_INT(_kern_hwpmc, OID_AUTO, hashsize, CTLFLAG_RDTUN, 327 &pmc_hashsize, 0, "rows in hash tables"); 328 329 /* 330 * kern.hwpmc.nsamples --- number of PC samples/callchain stacks per CPU 331 */ 332 333 static int pmc_nsamples = PMC_NSAMPLES; 334 SYSCTL_INT(_kern_hwpmc, OID_AUTO, nsamples, CTLFLAG_RDTUN, 335 &pmc_nsamples, 0, "number of PC samples per CPU"); 336 337 static uint64_t pmc_sample_mask = PMC_NSAMPLES-1; 338 339 /* 340 * kern.hwpmc.mtxpoolsize -- number of mutexes in the mutex pool. 341 */ 342 343 static int pmc_mtxpool_size = PMC_MTXPOOL_SIZE; 344 SYSCTL_INT(_kern_hwpmc, OID_AUTO, mtxpoolsize, CTLFLAG_RDTUN, 345 &pmc_mtxpool_size, 0, "size of spin mutex pool"); 346 347 348 /* 349 * kern.hwpmc.threadfreelist_entries -- number of free entries 350 */ 351 352 SYSCTL_INT(_kern_hwpmc, OID_AUTO, threadfreelist_entries, CTLFLAG_RD, 353 &pmc_threadfreelist_entries, 0, "number of available thread entries"); 354 355 356 /* 357 * kern.hwpmc.threadfreelist_max -- maximum number of free entries 358 */ 359 360 static int pmc_threadfreelist_max = PMC_THREADLIST_MAX; 361 SYSCTL_INT(_kern_hwpmc, OID_AUTO, threadfreelist_max, CTLFLAG_RW, 362 &pmc_threadfreelist_max, 0, 363 "maximum number of available thread entries before freeing some"); 364 365 366 /* 367 * kern.hwpmc.mincount -- minimum sample count 368 */ 369 static u_int pmc_mincount = 1000; 370 SYSCTL_INT(_kern_hwpmc, OID_AUTO, mincount, CTLFLAG_RWTUN, 371 &pmc_mincount, 0, 372 "minimum count for sampling counters"); 373 374 /* 375 * security.bsd.unprivileged_syspmcs -- allow non-root processes to 376 * allocate system-wide PMCs. 377 * 378 * Allowing unprivileged processes to allocate system PMCs is convenient 379 * if system-wide measurements need to be taken concurrently with other 380 * per-process measurements. This feature is turned off by default. 381 */ 382 383 static int pmc_unprivileged_syspmcs = 0; 384 SYSCTL_INT(_security_bsd, OID_AUTO, unprivileged_syspmcs, CTLFLAG_RWTUN, 385 &pmc_unprivileged_syspmcs, 0, 386 "allow unprivileged process to allocate system PMCs"); 387 388 /* 389 * Hash function. Discard the lower 2 bits of the pointer since 390 * these are always zero for our uses. The hash multiplier is 391 * round((2^LONG_BIT) * ((sqrt(5)-1)/2)). 392 */ 393 394 #if LONG_BIT == 64 395 #define _PMC_HM 11400714819323198486u 396 #elif LONG_BIT == 32 397 #define _PMC_HM 2654435769u 398 #else 399 #error Must know the size of 'long' to compile 400 #endif 401 402 #define PMC_HASH_PTR(P,M) ((((unsigned long) (P) >> 2) * _PMC_HM) & (M)) 403 404 /* 405 * Syscall structures 406 */ 407 408 /* The `sysent' for the new syscall */ 409 static struct sysent pmc_sysent = { 410 .sy_narg = 2, 411 .sy_call = pmc_syscall_handler, 412 }; 413 414 static struct syscall_module_data pmc_syscall_mod = { 415 .chainevh = load, 416 .chainarg = NULL, 417 .offset = &pmc_syscall_num, 418 .new_sysent = &pmc_sysent, 419 .old_sysent = { .sy_narg = 0, .sy_call = NULL }, 420 .flags = SY_THR_STATIC_KLD, 421 }; 422 423 static moduledata_t pmc_mod = { 424 .name = PMC_MODULE_NAME, 425 .evhand = syscall_module_handler, 426 .priv = &pmc_syscall_mod, 427 }; 428 429 #ifdef EARLY_AP_STARTUP 430 DECLARE_MODULE(pmc, pmc_mod, SI_SUB_SYSCALLS, SI_ORDER_ANY); 431 #else 432 DECLARE_MODULE(pmc, pmc_mod, SI_SUB_SMP, SI_ORDER_ANY); 433 #endif 434 MODULE_VERSION(pmc, PMC_VERSION); 435 436 #ifdef HWPMC_DEBUG 437 enum pmc_dbgparse_state { 438 PMCDS_WS, /* in whitespace */ 439 PMCDS_MAJOR, /* seen a major keyword */ 440 PMCDS_MINOR 441 }; 442 443 static int 444 pmc_debugflags_parse(char *newstr, char *fence) 445 { 446 char c, *p, *q; 447 struct pmc_debugflags *tmpflags; 448 int error, found, *newbits, tmp; 449 size_t kwlen; 450 451 tmpflags = malloc(sizeof(*tmpflags), M_PMC, M_WAITOK|M_ZERO); 452 453 p = newstr; 454 error = 0; 455 456 for (; p < fence && (c = *p); p++) { 457 458 /* skip white space */ 459 if (c == ' ' || c == '\t') 460 continue; 461 462 /* look for a keyword followed by "=" */ 463 for (q = p; p < fence && (c = *p) && c != '='; p++) 464 ; 465 if (c != '=') { 466 error = EINVAL; 467 goto done; 468 } 469 470 kwlen = p - q; 471 newbits = NULL; 472 473 /* lookup flag group name */ 474 #define DBG_SET_FLAG_MAJ(S,F) \ 475 if (kwlen == sizeof(S)-1 && strncmp(q, S, kwlen) == 0) \ 476 newbits = &tmpflags->pdb_ ## F; 477 478 DBG_SET_FLAG_MAJ("cpu", CPU); 479 DBG_SET_FLAG_MAJ("csw", CSW); 480 DBG_SET_FLAG_MAJ("logging", LOG); 481 DBG_SET_FLAG_MAJ("module", MOD); 482 DBG_SET_FLAG_MAJ("md", MDP); 483 DBG_SET_FLAG_MAJ("owner", OWN); 484 DBG_SET_FLAG_MAJ("pmc", PMC); 485 DBG_SET_FLAG_MAJ("process", PRC); 486 DBG_SET_FLAG_MAJ("sampling", SAM); 487 488 if (newbits == NULL) { 489 error = EINVAL; 490 goto done; 491 } 492 493 p++; /* skip the '=' */ 494 495 /* Now parse the individual flags */ 496 tmp = 0; 497 newflag: 498 for (q = p; p < fence && (c = *p); p++) 499 if (c == ' ' || c == '\t' || c == ',') 500 break; 501 502 /* p == fence or c == ws or c == "," or c == 0 */ 503 504 if ((kwlen = p - q) == 0) { 505 *newbits = tmp; 506 continue; 507 } 508 509 found = 0; 510 #define DBG_SET_FLAG_MIN(S,F) \ 511 if (kwlen == sizeof(S)-1 && strncmp(q, S, kwlen) == 0) \ 512 tmp |= found = (1 << PMC_DEBUG_MIN_ ## F) 513 514 /* a '*' denotes all possible flags in the group */ 515 if (kwlen == 1 && *q == '*') 516 tmp = found = ~0; 517 /* look for individual flag names */ 518 DBG_SET_FLAG_MIN("allocaterow", ALR); 519 DBG_SET_FLAG_MIN("allocate", ALL); 520 DBG_SET_FLAG_MIN("attach", ATT); 521 DBG_SET_FLAG_MIN("bind", BND); 522 DBG_SET_FLAG_MIN("config", CFG); 523 DBG_SET_FLAG_MIN("exec", EXC); 524 DBG_SET_FLAG_MIN("exit", EXT); 525 DBG_SET_FLAG_MIN("find", FND); 526 DBG_SET_FLAG_MIN("flush", FLS); 527 DBG_SET_FLAG_MIN("fork", FRK); 528 DBG_SET_FLAG_MIN("getbuf", GTB); 529 DBG_SET_FLAG_MIN("hook", PMH); 530 DBG_SET_FLAG_MIN("init", INI); 531 DBG_SET_FLAG_MIN("intr", INT); 532 DBG_SET_FLAG_MIN("linktarget", TLK); 533 DBG_SET_FLAG_MIN("mayberemove", OMR); 534 DBG_SET_FLAG_MIN("ops", OPS); 535 DBG_SET_FLAG_MIN("read", REA); 536 DBG_SET_FLAG_MIN("register", REG); 537 DBG_SET_FLAG_MIN("release", REL); 538 DBG_SET_FLAG_MIN("remove", ORM); 539 DBG_SET_FLAG_MIN("sample", SAM); 540 DBG_SET_FLAG_MIN("scheduleio", SIO); 541 DBG_SET_FLAG_MIN("select", SEL); 542 DBG_SET_FLAG_MIN("signal", SIG); 543 DBG_SET_FLAG_MIN("swi", SWI); 544 DBG_SET_FLAG_MIN("swo", SWO); 545 DBG_SET_FLAG_MIN("start", STA); 546 DBG_SET_FLAG_MIN("stop", STO); 547 DBG_SET_FLAG_MIN("syscall", PMS); 548 DBG_SET_FLAG_MIN("unlinktarget", TUL); 549 DBG_SET_FLAG_MIN("write", WRI); 550 if (found == 0) { 551 /* unrecognized flag name */ 552 error = EINVAL; 553 goto done; 554 } 555 556 if (c == 0 || c == ' ' || c == '\t') { /* end of flag group */ 557 *newbits = tmp; 558 continue; 559 } 560 561 p++; 562 goto newflag; 563 } 564 565 /* save the new flag set */ 566 bcopy(tmpflags, &pmc_debugflags, sizeof(pmc_debugflags)); 567 568 done: 569 free(tmpflags, M_PMC); 570 return error; 571 } 572 573 static int 574 pmc_debugflags_sysctl_handler(SYSCTL_HANDLER_ARGS) 575 { 576 char *fence, *newstr; 577 int error; 578 unsigned int n; 579 580 (void) arg1; (void) arg2; /* unused parameters */ 581 582 n = sizeof(pmc_debugstr); 583 newstr = malloc(n, M_PMC, M_WAITOK|M_ZERO); 584 (void) strlcpy(newstr, pmc_debugstr, n); 585 586 error = sysctl_handle_string(oidp, newstr, n, req); 587 588 /* if there is a new string, parse and copy it */ 589 if (error == 0 && req->newptr != NULL) { 590 fence = newstr + (n < req->newlen ? n : req->newlen + 1); 591 if ((error = pmc_debugflags_parse(newstr, fence)) == 0) 592 (void) strlcpy(pmc_debugstr, newstr, 593 sizeof(pmc_debugstr)); 594 } 595 596 free(newstr, M_PMC); 597 598 return error; 599 } 600 #endif 601 602 /* 603 * Map a row index to a classdep structure and return the adjusted row 604 * index for the PMC class index. 605 */ 606 static struct pmc_classdep * 607 pmc_ri_to_classdep(struct pmc_mdep *md, int ri, int *adjri) 608 { 609 struct pmc_classdep *pcd; 610 611 (void) md; 612 613 KASSERT(ri >= 0 && ri < md->pmd_npmc, 614 ("[pmc,%d] illegal row-index %d", __LINE__, ri)); 615 616 pcd = pmc_rowindex_to_classdep[ri]; 617 618 KASSERT(pcd != NULL, 619 ("[pmc,%d] ri %d null pcd", __LINE__, ri)); 620 621 *adjri = ri - pcd->pcd_ri; 622 623 KASSERT(*adjri >= 0 && *adjri < pcd->pcd_num, 624 ("[pmc,%d] adjusted row-index %d", __LINE__, *adjri)); 625 626 return (pcd); 627 } 628 629 /* 630 * Concurrency Control 631 * 632 * The driver manages the following data structures: 633 * 634 * - target process descriptors, one per target process 635 * - owner process descriptors (and attached lists), one per owner process 636 * - lookup hash tables for owner and target processes 637 * - PMC descriptors (and attached lists) 638 * - per-cpu hardware state 639 * - the 'hook' variable through which the kernel calls into 640 * this module 641 * - the machine hardware state (managed by the MD layer) 642 * 643 * These data structures are accessed from: 644 * 645 * - thread context-switch code 646 * - interrupt handlers (possibly on multiple cpus) 647 * - kernel threads on multiple cpus running on behalf of user 648 * processes doing system calls 649 * - this driver's private kernel threads 650 * 651 * = Locks and Locking strategy = 652 * 653 * The driver uses four locking strategies for its operation: 654 * 655 * - The global SX lock "pmc_sx" is used to protect internal 656 * data structures. 657 * 658 * Calls into the module by syscall() start with this lock being 659 * held in exclusive mode. Depending on the requested operation, 660 * the lock may be downgraded to 'shared' mode to allow more 661 * concurrent readers into the module. Calls into the module from 662 * other parts of the kernel acquire the lock in shared mode. 663 * 664 * This SX lock is held in exclusive mode for any operations that 665 * modify the linkages between the driver's internal data structures. 666 * 667 * The 'pmc_hook' function pointer is also protected by this lock. 668 * It is only examined with the sx lock held in exclusive mode. The 669 * kernel module is allowed to be unloaded only with the sx lock held 670 * in exclusive mode. In normal syscall handling, after acquiring the 671 * pmc_sx lock we first check that 'pmc_hook' is non-null before 672 * proceeding. This prevents races between the thread unloading the module 673 * and other threads seeking to use the module. 674 * 675 * - Lookups of target process structures and owner process structures 676 * cannot use the global "pmc_sx" SX lock because these lookups need 677 * to happen during context switches and in other critical sections 678 * where sleeping is not allowed. We protect these lookup tables 679 * with their own private spin-mutexes, "pmc_processhash_mtx" and 680 * "pmc_ownerhash_mtx". 681 * 682 * - Interrupt handlers work in a lock free manner. At interrupt 683 * time, handlers look at the PMC pointer (phw->phw_pmc) configured 684 * when the PMC was started. If this pointer is NULL, the interrupt 685 * is ignored after updating driver statistics. We ensure that this 686 * pointer is set (using an atomic operation if necessary) before the 687 * PMC hardware is started. Conversely, this pointer is unset atomically 688 * only after the PMC hardware is stopped. 689 * 690 * We ensure that everything needed for the operation of an 691 * interrupt handler is available without it needing to acquire any 692 * locks. We also ensure that a PMC's software state is destroyed only 693 * after the PMC is taken off hardware (on all CPUs). 694 * 695 * - Context-switch handling with process-private PMCs needs more 696 * care. 697 * 698 * A given process may be the target of multiple PMCs. For example, 699 * PMCATTACH and PMCDETACH may be requested by a process on one CPU 700 * while the target process is running on another. A PMC could also 701 * be getting released because its owner is exiting. We tackle 702 * these situations in the following manner: 703 * 704 * - each target process structure 'pmc_process' has an array 705 * of 'struct pmc *' pointers, one for each hardware PMC. 706 * 707 * - At context switch IN time, each "target" PMC in RUNNING state 708 * gets started on hardware and a pointer to each PMC is copied into 709 * the per-cpu phw array. The 'runcount' for the PMC is 710 * incremented. 711 * 712 * - At context switch OUT time, all process-virtual PMCs are stopped 713 * on hardware. The saved value is added to the PMCs value field 714 * only if the PMC is in a non-deleted state (the PMCs state could 715 * have changed during the current time slice). 716 * 717 * Note that since in-between a switch IN on a processor and a switch 718 * OUT, the PMC could have been released on another CPU. Therefore 719 * context switch OUT always looks at the hardware state to turn 720 * OFF PMCs and will update a PMC's saved value only if reachable 721 * from the target process record. 722 * 723 * - OP PMCRELEASE could be called on a PMC at any time (the PMC could 724 * be attached to many processes at the time of the call and could 725 * be active on multiple CPUs). 726 * 727 * We prevent further scheduling of the PMC by marking it as in 728 * state 'DELETED'. If the runcount of the PMC is non-zero then 729 * this PMC is currently running on a CPU somewhere. The thread 730 * doing the PMCRELEASE operation waits by repeatedly doing a 731 * pause() till the runcount comes to zero. 732 * 733 * The contents of a PMC descriptor (struct pmc) are protected using 734 * a spin-mutex. In order to save space, we use a mutex pool. 735 * 736 * In terms of lock types used by witness(4), we use: 737 * - Type "pmc-sx", used by the global SX lock. 738 * - Type "pmc-sleep", for sleep mutexes used by logger threads. 739 * - Type "pmc-per-proc", for protecting PMC owner descriptors. 740 * - Type "pmc-leaf", used for all other spin mutexes. 741 */ 742 743 /* 744 * save the cpu binding of the current kthread 745 */ 746 747 void 748 pmc_save_cpu_binding(struct pmc_binding *pb) 749 { 750 PMCDBG0(CPU,BND,2, "save-cpu"); 751 thread_lock(curthread); 752 pb->pb_bound = sched_is_bound(curthread); 753 pb->pb_cpu = curthread->td_oncpu; 754 pb->pb_priority = curthread->td_priority; 755 thread_unlock(curthread); 756 PMCDBG1(CPU,BND,2, "save-cpu cpu=%d", pb->pb_cpu); 757 } 758 759 /* 760 * restore the cpu binding of the current thread 761 */ 762 763 void 764 pmc_restore_cpu_binding(struct pmc_binding *pb) 765 { 766 PMCDBG2(CPU,BND,2, "restore-cpu curcpu=%d restore=%d", 767 curthread->td_oncpu, pb->pb_cpu); 768 thread_lock(curthread); 769 sched_bind(curthread, pb->pb_cpu); 770 if (!pb->pb_bound) 771 sched_unbind(curthread); 772 sched_prio(curthread, pb->pb_priority); 773 thread_unlock(curthread); 774 PMCDBG0(CPU,BND,2, "restore-cpu done"); 775 } 776 777 /* 778 * move execution over the specified cpu and bind it there. 779 */ 780 781 void 782 pmc_select_cpu(int cpu) 783 { 784 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 785 ("[pmc,%d] bad cpu number %d", __LINE__, cpu)); 786 787 /* Never move to an inactive CPU. */ 788 KASSERT(pmc_cpu_is_active(cpu), ("[pmc,%d] selecting inactive " 789 "CPU %d", __LINE__, cpu)); 790 791 PMCDBG1(CPU,SEL,2, "select-cpu cpu=%d", cpu); 792 thread_lock(curthread); 793 sched_prio(curthread, PRI_MIN); 794 sched_bind(curthread, cpu); 795 thread_unlock(curthread); 796 797 KASSERT(curthread->td_oncpu == cpu, 798 ("[pmc,%d] CPU not bound [cpu=%d, curr=%d]", __LINE__, 799 cpu, curthread->td_oncpu)); 800 801 PMCDBG1(CPU,SEL,2, "select-cpu cpu=%d ok", cpu); 802 } 803 804 /* 805 * Force a context switch. 806 * 807 * We do this by pause'ing for 1 tick -- invoking mi_switch() is not 808 * guaranteed to force a context switch. 809 */ 810 811 static void 812 pmc_force_context_switch(void) 813 { 814 815 pause("pmcctx", 1); 816 } 817 818 uint64_t 819 pmc_rdtsc(void) 820 { 821 #if defined(__i386__) || defined(__amd64__) 822 if (__predict_true(amd_feature & AMDID_RDTSCP)) 823 return rdtscp(); 824 else 825 return rdtsc(); 826 #else 827 return get_cyclecount(); 828 #endif 829 } 830 831 /* 832 * Get the file name for an executable. This is a simple wrapper 833 * around vn_fullpath(9). 834 */ 835 836 static void 837 pmc_getfilename(struct vnode *v, char **fullpath, char **freepath) 838 { 839 840 *fullpath = "unknown"; 841 *freepath = NULL; 842 vn_fullpath(v, fullpath, freepath); 843 } 844 845 /* 846 * remove an process owning PMCs 847 */ 848 849 void 850 pmc_remove_owner(struct pmc_owner *po) 851 { 852 struct pmc *pm, *tmp; 853 854 sx_assert(&pmc_sx, SX_XLOCKED); 855 856 PMCDBG1(OWN,ORM,1, "remove-owner po=%p", po); 857 858 /* Remove descriptor from the owner hash table */ 859 LIST_REMOVE(po, po_next); 860 861 /* release all owned PMC descriptors */ 862 LIST_FOREACH_SAFE(pm, &po->po_pmcs, pm_next, tmp) { 863 PMCDBG1(OWN,ORM,2, "pmc=%p", pm); 864 KASSERT(pm->pm_owner == po, 865 ("[pmc,%d] owner %p != po %p", __LINE__, pm->pm_owner, po)); 866 867 pmc_release_pmc_descriptor(pm); /* will unlink from the list */ 868 pmc_destroy_pmc_descriptor(pm); 869 } 870 871 KASSERT(po->po_sscount == 0, 872 ("[pmc,%d] SS count not zero", __LINE__)); 873 KASSERT(LIST_EMPTY(&po->po_pmcs), 874 ("[pmc,%d] PMC list not empty", __LINE__)); 875 876 /* de-configure the log file if present */ 877 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 878 pmclog_deconfigure_log(po); 879 } 880 881 /* 882 * remove an owner process record if all conditions are met. 883 */ 884 885 static void 886 pmc_maybe_remove_owner(struct pmc_owner *po) 887 { 888 889 PMCDBG1(OWN,OMR,1, "maybe-remove-owner po=%p", po); 890 891 /* 892 * Remove owner record if 893 * - this process does not own any PMCs 894 * - this process has not allocated a system-wide sampling buffer 895 */ 896 897 if (LIST_EMPTY(&po->po_pmcs) && 898 ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0)) { 899 pmc_remove_owner(po); 900 pmc_destroy_owner_descriptor(po); 901 } 902 } 903 904 /* 905 * Add an association between a target process and a PMC. 906 */ 907 908 static void 909 pmc_link_target_process(struct pmc *pm, struct pmc_process *pp) 910 { 911 int ri; 912 struct pmc_target *pt; 913 #ifdef INVARIANTS 914 struct pmc_thread *pt_td; 915 #endif 916 917 sx_assert(&pmc_sx, SX_XLOCKED); 918 919 KASSERT(pm != NULL && pp != NULL, 920 ("[pmc,%d] Null pm %p or pp %p", __LINE__, pm, pp)); 921 KASSERT(PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)), 922 ("[pmc,%d] Attaching a non-process-virtual pmc=%p to pid=%d", 923 __LINE__, pm, pp->pp_proc->p_pid)); 924 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= ((int) md->pmd_npmc - 1), 925 ("[pmc,%d] Illegal reference count %d for process record %p", 926 __LINE__, pp->pp_refcnt, (void *) pp)); 927 928 ri = PMC_TO_ROWINDEX(pm); 929 930 PMCDBG3(PRC,TLK,1, "link-target pmc=%p ri=%d pmc-process=%p", 931 pm, ri, pp); 932 933 #ifdef HWPMC_DEBUG 934 LIST_FOREACH(pt, &pm->pm_targets, pt_next) 935 if (pt->pt_process == pp) 936 KASSERT(0, ("[pmc,%d] pp %p already in pmc %p targets", 937 __LINE__, pp, pm)); 938 #endif 939 940 pt = malloc(sizeof(struct pmc_target), M_PMC, M_WAITOK|M_ZERO); 941 pt->pt_process = pp; 942 943 LIST_INSERT_HEAD(&pm->pm_targets, pt, pt_next); 944 945 atomic_store_rel_ptr((uintptr_t *)&pp->pp_pmcs[ri].pp_pmc, 946 (uintptr_t)pm); 947 948 if (pm->pm_owner->po_owner == pp->pp_proc) 949 pm->pm_flags |= PMC_F_ATTACHED_TO_OWNER; 950 951 /* 952 * Initialize the per-process values at this row index. 953 */ 954 pp->pp_pmcs[ri].pp_pmcval = PMC_TO_MODE(pm) == PMC_MODE_TS ? 955 pm->pm_sc.pm_reloadcount : 0; 956 957 pp->pp_refcnt++; 958 959 #ifdef INVARIANTS 960 /* Confirm that the per-thread values at this row index are cleared. */ 961 if (PMC_TO_MODE(pm) == PMC_MODE_TS) { 962 mtx_lock_spin(pp->pp_tdslock); 963 LIST_FOREACH(pt_td, &pp->pp_tds, pt_next) { 964 KASSERT(pt_td->pt_pmcs[ri].pt_pmcval == (pmc_value_t) 0, 965 ("[pmc,%d] pt_pmcval not cleared for pid=%d at " 966 "ri=%d", __LINE__, pp->pp_proc->p_pid, ri)); 967 } 968 mtx_unlock_spin(pp->pp_tdslock); 969 } 970 #endif 971 } 972 973 /* 974 * Removes the association between a target process and a PMC. 975 */ 976 977 static void 978 pmc_unlink_target_process(struct pmc *pm, struct pmc_process *pp) 979 { 980 int ri; 981 struct proc *p; 982 struct pmc_target *ptgt; 983 struct pmc_thread *pt; 984 985 sx_assert(&pmc_sx, SX_XLOCKED); 986 987 KASSERT(pm != NULL && pp != NULL, 988 ("[pmc,%d] Null pm %p or pp %p", __LINE__, pm, pp)); 989 990 KASSERT(pp->pp_refcnt >= 1 && pp->pp_refcnt <= (int) md->pmd_npmc, 991 ("[pmc,%d] Illegal ref count %d on process record %p", 992 __LINE__, pp->pp_refcnt, (void *) pp)); 993 994 ri = PMC_TO_ROWINDEX(pm); 995 996 PMCDBG3(PRC,TUL,1, "unlink-target pmc=%p ri=%d pmc-process=%p", 997 pm, ri, pp); 998 999 KASSERT(pp->pp_pmcs[ri].pp_pmc == pm, 1000 ("[pmc,%d] PMC ri %d mismatch pmc %p pp->[ri] %p", __LINE__, 1001 ri, pm, pp->pp_pmcs[ri].pp_pmc)); 1002 1003 pp->pp_pmcs[ri].pp_pmc = NULL; 1004 pp->pp_pmcs[ri].pp_pmcval = (pmc_value_t) 0; 1005 1006 /* Clear the per-thread values at this row index. */ 1007 if (PMC_TO_MODE(pm) == PMC_MODE_TS) { 1008 mtx_lock_spin(pp->pp_tdslock); 1009 LIST_FOREACH(pt, &pp->pp_tds, pt_next) 1010 pt->pt_pmcs[ri].pt_pmcval = (pmc_value_t) 0; 1011 mtx_unlock_spin(pp->pp_tdslock); 1012 } 1013 1014 /* Remove owner-specific flags */ 1015 if (pm->pm_owner->po_owner == pp->pp_proc) { 1016 pp->pp_flags &= ~PMC_PP_ENABLE_MSR_ACCESS; 1017 pm->pm_flags &= ~PMC_F_ATTACHED_TO_OWNER; 1018 } 1019 1020 pp->pp_refcnt--; 1021 1022 /* Remove the target process from the PMC structure */ 1023 LIST_FOREACH(ptgt, &pm->pm_targets, pt_next) 1024 if (ptgt->pt_process == pp) 1025 break; 1026 1027 KASSERT(ptgt != NULL, ("[pmc,%d] process %p (pp: %p) not found " 1028 "in pmc %p", __LINE__, pp->pp_proc, pp, pm)); 1029 1030 LIST_REMOVE(ptgt, pt_next); 1031 free(ptgt, M_PMC); 1032 1033 /* if the PMC now lacks targets, send the owner a SIGIO */ 1034 if (LIST_EMPTY(&pm->pm_targets)) { 1035 p = pm->pm_owner->po_owner; 1036 PROC_LOCK(p); 1037 kern_psignal(p, SIGIO); 1038 PROC_UNLOCK(p); 1039 1040 PMCDBG2(PRC,SIG,2, "signalling proc=%p signal=%d", p, 1041 SIGIO); 1042 } 1043 } 1044 1045 /* 1046 * Check if PMC 'pm' may be attached to target process 't'. 1047 */ 1048 1049 static int 1050 pmc_can_attach(struct pmc *pm, struct proc *t) 1051 { 1052 struct proc *o; /* pmc owner */ 1053 struct ucred *oc, *tc; /* owner, target credentials */ 1054 int decline_attach, i; 1055 1056 /* 1057 * A PMC's owner can always attach that PMC to itself. 1058 */ 1059 1060 if ((o = pm->pm_owner->po_owner) == t) 1061 return 0; 1062 1063 PROC_LOCK(o); 1064 oc = o->p_ucred; 1065 crhold(oc); 1066 PROC_UNLOCK(o); 1067 1068 PROC_LOCK(t); 1069 tc = t->p_ucred; 1070 crhold(tc); 1071 PROC_UNLOCK(t); 1072 1073 /* 1074 * The effective uid of the PMC owner should match at least one 1075 * of the {effective,real,saved} uids of the target process. 1076 */ 1077 1078 decline_attach = oc->cr_uid != tc->cr_uid && 1079 oc->cr_uid != tc->cr_svuid && 1080 oc->cr_uid != tc->cr_ruid; 1081 1082 /* 1083 * Every one of the target's group ids, must be in the owner's 1084 * group list. 1085 */ 1086 for (i = 0; !decline_attach && i < tc->cr_ngroups; i++) 1087 decline_attach = !groupmember(tc->cr_groups[i], oc); 1088 1089 /* check the read and saved gids too */ 1090 if (decline_attach == 0) 1091 decline_attach = !groupmember(tc->cr_rgid, oc) || 1092 !groupmember(tc->cr_svgid, oc); 1093 1094 crfree(tc); 1095 crfree(oc); 1096 1097 return !decline_attach; 1098 } 1099 1100 /* 1101 * Attach a process to a PMC. 1102 */ 1103 1104 static int 1105 pmc_attach_one_process(struct proc *p, struct pmc *pm) 1106 { 1107 int ri, error; 1108 char *fullpath, *freepath; 1109 struct pmc_process *pp; 1110 1111 sx_assert(&pmc_sx, SX_XLOCKED); 1112 1113 PMCDBG5(PRC,ATT,2, "attach-one pm=%p ri=%d proc=%p (%d, %s)", pm, 1114 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 1115 1116 /* 1117 * Locate the process descriptor corresponding to process 'p', 1118 * allocating space as needed. 1119 * 1120 * Verify that rowindex 'pm_rowindex' is free in the process 1121 * descriptor. 1122 * 1123 * If not, allocate space for a descriptor and link the 1124 * process descriptor and PMC. 1125 */ 1126 ri = PMC_TO_ROWINDEX(pm); 1127 1128 /* mark process as using HWPMCs */ 1129 PROC_LOCK(p); 1130 p->p_flag |= P_HWPMC; 1131 PROC_UNLOCK(p); 1132 1133 if ((pp = pmc_find_process_descriptor(p, PMC_FLAG_ALLOCATE)) == NULL) { 1134 error = ENOMEM; 1135 goto fail; 1136 } 1137 1138 if (pp->pp_pmcs[ri].pp_pmc == pm) {/* already present at slot [ri] */ 1139 error = EEXIST; 1140 goto fail; 1141 } 1142 1143 if (pp->pp_pmcs[ri].pp_pmc != NULL) { 1144 error = EBUSY; 1145 goto fail; 1146 } 1147 1148 pmc_link_target_process(pm, pp); 1149 1150 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)) && 1151 (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) == 0) 1152 pm->pm_flags |= PMC_F_NEEDS_LOGFILE; 1153 1154 pm->pm_flags |= PMC_F_ATTACH_DONE; /* mark as attached */ 1155 1156 /* issue an attach event to a configured log file */ 1157 if (pm->pm_owner->po_flags & PMC_PO_OWNS_LOGFILE) { 1158 if (p->p_flag & P_KPROC) { 1159 fullpath = kernelname; 1160 freepath = NULL; 1161 } else { 1162 pmc_getfilename(p->p_textvp, &fullpath, &freepath); 1163 pmclog_process_pmcattach(pm, p->p_pid, fullpath); 1164 } 1165 free(freepath, M_TEMP); 1166 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 1167 pmc_log_process_mappings(pm->pm_owner, p); 1168 } 1169 1170 return (0); 1171 fail: 1172 PROC_LOCK(p); 1173 p->p_flag &= ~P_HWPMC; 1174 PROC_UNLOCK(p); 1175 return (error); 1176 } 1177 1178 /* 1179 * Attach a process and optionally its children 1180 */ 1181 1182 static int 1183 pmc_attach_process(struct proc *p, struct pmc *pm) 1184 { 1185 int error; 1186 struct proc *top; 1187 1188 sx_assert(&pmc_sx, SX_XLOCKED); 1189 1190 PMCDBG5(PRC,ATT,1, "attach pm=%p ri=%d proc=%p (%d, %s)", pm, 1191 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 1192 1193 1194 /* 1195 * If this PMC successfully allowed a GETMSR operation 1196 * in the past, disallow further ATTACHes. 1197 */ 1198 1199 if ((pm->pm_flags & PMC_PP_ENABLE_MSR_ACCESS) != 0) 1200 return EPERM; 1201 1202 if ((pm->pm_flags & PMC_F_DESCENDANTS) == 0) 1203 return pmc_attach_one_process(p, pm); 1204 1205 /* 1206 * Traverse all child processes, attaching them to 1207 * this PMC. 1208 */ 1209 1210 sx_slock(&proctree_lock); 1211 1212 top = p; 1213 1214 for (;;) { 1215 if ((error = pmc_attach_one_process(p, pm)) != 0) 1216 break; 1217 if (!LIST_EMPTY(&p->p_children)) 1218 p = LIST_FIRST(&p->p_children); 1219 else for (;;) { 1220 if (p == top) 1221 goto done; 1222 if (LIST_NEXT(p, p_sibling)) { 1223 p = LIST_NEXT(p, p_sibling); 1224 break; 1225 } 1226 p = p->p_pptr; 1227 } 1228 } 1229 1230 if (error) 1231 (void) pmc_detach_process(top, pm); 1232 1233 done: 1234 sx_sunlock(&proctree_lock); 1235 return error; 1236 } 1237 1238 /* 1239 * Detach a process from a PMC. If there are no other PMCs tracking 1240 * this process, remove the process structure from its hash table. If 1241 * 'flags' contains PMC_FLAG_REMOVE, then free the process structure. 1242 */ 1243 1244 static int 1245 pmc_detach_one_process(struct proc *p, struct pmc *pm, int flags) 1246 { 1247 int ri; 1248 struct pmc_process *pp; 1249 1250 sx_assert(&pmc_sx, SX_XLOCKED); 1251 1252 KASSERT(pm != NULL, 1253 ("[pmc,%d] null pm pointer", __LINE__)); 1254 1255 ri = PMC_TO_ROWINDEX(pm); 1256 1257 PMCDBG6(PRC,ATT,2, "detach-one pm=%p ri=%d proc=%p (%d, %s) flags=0x%x", 1258 pm, ri, p, p->p_pid, p->p_comm, flags); 1259 1260 if ((pp = pmc_find_process_descriptor(p, 0)) == NULL) 1261 return ESRCH; 1262 1263 if (pp->pp_pmcs[ri].pp_pmc != pm) 1264 return EINVAL; 1265 1266 pmc_unlink_target_process(pm, pp); 1267 1268 /* Issue a detach entry if a log file is configured */ 1269 if (pm->pm_owner->po_flags & PMC_PO_OWNS_LOGFILE) 1270 pmclog_process_pmcdetach(pm, p->p_pid); 1271 1272 /* 1273 * If there are no PMCs targeting this process, we remove its 1274 * descriptor from the target hash table and unset the P_HWPMC 1275 * flag in the struct proc. 1276 */ 1277 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= (int) md->pmd_npmc, 1278 ("[pmc,%d] Illegal refcnt %d for process struct %p", 1279 __LINE__, pp->pp_refcnt, pp)); 1280 1281 if (pp->pp_refcnt != 0) /* still a target of some PMC */ 1282 return 0; 1283 1284 pmc_remove_process_descriptor(pp); 1285 1286 if (flags & PMC_FLAG_REMOVE) 1287 pmc_destroy_process_descriptor(pp); 1288 1289 PROC_LOCK(p); 1290 p->p_flag &= ~P_HWPMC; 1291 PROC_UNLOCK(p); 1292 1293 return 0; 1294 } 1295 1296 /* 1297 * Detach a process and optionally its descendants from a PMC. 1298 */ 1299 1300 static int 1301 pmc_detach_process(struct proc *p, struct pmc *pm) 1302 { 1303 struct proc *top; 1304 1305 sx_assert(&pmc_sx, SX_XLOCKED); 1306 1307 PMCDBG5(PRC,ATT,1, "detach pm=%p ri=%d proc=%p (%d, %s)", pm, 1308 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 1309 1310 if ((pm->pm_flags & PMC_F_DESCENDANTS) == 0) 1311 return pmc_detach_one_process(p, pm, PMC_FLAG_REMOVE); 1312 1313 /* 1314 * Traverse all children, detaching them from this PMC. We 1315 * ignore errors since we could be detaching a PMC from a 1316 * partially attached proc tree. 1317 */ 1318 1319 sx_slock(&proctree_lock); 1320 1321 top = p; 1322 1323 for (;;) { 1324 (void) pmc_detach_one_process(p, pm, PMC_FLAG_REMOVE); 1325 1326 if (!LIST_EMPTY(&p->p_children)) 1327 p = LIST_FIRST(&p->p_children); 1328 else for (;;) { 1329 if (p == top) 1330 goto done; 1331 if (LIST_NEXT(p, p_sibling)) { 1332 p = LIST_NEXT(p, p_sibling); 1333 break; 1334 } 1335 p = p->p_pptr; 1336 } 1337 } 1338 1339 done: 1340 sx_sunlock(&proctree_lock); 1341 1342 if (LIST_EMPTY(&pm->pm_targets)) 1343 pm->pm_flags &= ~PMC_F_ATTACH_DONE; 1344 1345 return 0; 1346 } 1347 1348 1349 /* 1350 * Thread context switch IN 1351 */ 1352 1353 static void 1354 pmc_process_csw_in(struct thread *td) 1355 { 1356 int cpu; 1357 unsigned int adjri, ri; 1358 struct pmc *pm; 1359 struct proc *p; 1360 struct pmc_cpu *pc; 1361 struct pmc_hw *phw __diagused; 1362 pmc_value_t newvalue; 1363 struct pmc_process *pp; 1364 struct pmc_thread *pt; 1365 struct pmc_classdep *pcd; 1366 1367 p = td->td_proc; 1368 pt = NULL; 1369 if ((pp = pmc_find_process_descriptor(p, PMC_FLAG_NONE)) == NULL) 1370 return; 1371 1372 KASSERT(pp->pp_proc == td->td_proc, 1373 ("[pmc,%d] not my thread state", __LINE__)); 1374 1375 critical_enter(); /* no preemption from this point */ 1376 1377 cpu = PCPU_GET(cpuid); /* td->td_oncpu is invalid */ 1378 1379 PMCDBG5(CSW,SWI,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p, 1380 p->p_pid, p->p_comm, pp); 1381 1382 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 1383 ("[pmc,%d] weird CPU id %d", __LINE__, cpu)); 1384 1385 pc = pmc_pcpu[cpu]; 1386 1387 for (ri = 0; ri < md->pmd_npmc; ri++) { 1388 1389 if ((pm = pp->pp_pmcs[ri].pp_pmc) == NULL) 1390 continue; 1391 1392 KASSERT(PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)), 1393 ("[pmc,%d] Target PMC in non-virtual mode (%d)", 1394 __LINE__, PMC_TO_MODE(pm))); 1395 1396 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 1397 ("[pmc,%d] Row index mismatch pmc %d != ri %d", 1398 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 1399 1400 /* 1401 * Only PMCs that are marked as 'RUNNING' need 1402 * be placed on hardware. 1403 */ 1404 1405 if (pm->pm_state != PMC_STATE_RUNNING) 1406 continue; 1407 1408 KASSERT(counter_u64_fetch(pm->pm_runcount) >= 0, 1409 ("[pmc,%d] pm=%p runcount %ld", __LINE__, (void *) pm, 1410 (unsigned long)counter_u64_fetch(pm->pm_runcount))); 1411 1412 /* increment PMC runcount */ 1413 counter_u64_add(pm->pm_runcount, 1); 1414 1415 /* configure the HWPMC we are going to use. */ 1416 pcd = pmc_ri_to_classdep(md, ri, &adjri); 1417 pcd->pcd_config_pmc(cpu, adjri, pm); 1418 1419 phw = pc->pc_hwpmcs[ri]; 1420 1421 KASSERT(phw != NULL, 1422 ("[pmc,%d] null hw pointer", __LINE__)); 1423 1424 KASSERT(phw->phw_pmc == pm, 1425 ("[pmc,%d] hw->pmc %p != pmc %p", __LINE__, 1426 phw->phw_pmc, pm)); 1427 1428 /* 1429 * Write out saved value and start the PMC. 1430 * 1431 * Sampling PMCs use a per-thread value, while 1432 * counting mode PMCs use a per-pmc value that is 1433 * inherited across descendants. 1434 */ 1435 if (PMC_TO_MODE(pm) == PMC_MODE_TS) { 1436 if (pt == NULL) 1437 pt = pmc_find_thread_descriptor(pp, td, 1438 PMC_FLAG_NONE); 1439 1440 KASSERT(pt != NULL, 1441 ("[pmc,%d] No thread found for td=%p", __LINE__, 1442 td)); 1443 1444 mtx_pool_lock_spin(pmc_mtxpool, pm); 1445 1446 /* 1447 * If we have a thread descriptor, use the per-thread 1448 * counter in the descriptor. If not, we will use 1449 * a per-process counter. 1450 * 1451 * TODO: Remove the per-process "safety net" once 1452 * we have thoroughly tested that we don't hit the 1453 * above assert. 1454 */ 1455 if (pt != NULL) { 1456 if (pt->pt_pmcs[ri].pt_pmcval > 0) 1457 newvalue = pt->pt_pmcs[ri].pt_pmcval; 1458 else 1459 newvalue = pm->pm_sc.pm_reloadcount; 1460 } else { 1461 /* 1462 * Use the saved value calculated after the most 1463 * recent time a thread using the shared counter 1464 * switched out. Reset the saved count in case 1465 * another thread from this process switches in 1466 * before any threads switch out. 1467 */ 1468 1469 newvalue = pp->pp_pmcs[ri].pp_pmcval; 1470 pp->pp_pmcs[ri].pp_pmcval = 1471 pm->pm_sc.pm_reloadcount; 1472 } 1473 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1474 KASSERT(newvalue > 0 && newvalue <= 1475 pm->pm_sc.pm_reloadcount, 1476 ("[pmc,%d] pmcval outside of expected range cpu=%d " 1477 "ri=%d pmcval=%jx pm_reloadcount=%jx", __LINE__, 1478 cpu, ri, newvalue, pm->pm_sc.pm_reloadcount)); 1479 } else { 1480 KASSERT(PMC_TO_MODE(pm) == PMC_MODE_TC, 1481 ("[pmc,%d] illegal mode=%d", __LINE__, 1482 PMC_TO_MODE(pm))); 1483 mtx_pool_lock_spin(pmc_mtxpool, pm); 1484 newvalue = PMC_PCPU_SAVED(cpu, ri) = 1485 pm->pm_gv.pm_savedvalue; 1486 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1487 } 1488 1489 PMCDBG3(CSW,SWI,1,"cpu=%d ri=%d new=%jd", cpu, ri, newvalue); 1490 1491 pcd->pcd_write_pmc(cpu, adjri, pm, newvalue); 1492 1493 /* If a sampling mode PMC, reset stalled state. */ 1494 if (PMC_TO_MODE(pm) == PMC_MODE_TS) 1495 pm->pm_pcpu_state[cpu].pps_stalled = 0; 1496 1497 /* Indicate that we desire this to run. */ 1498 pm->pm_pcpu_state[cpu].pps_cpustate = 1; 1499 1500 /* Start the PMC. */ 1501 pcd->pcd_start_pmc(cpu, adjri, pm); 1502 } 1503 1504 /* 1505 * perform any other architecture/cpu dependent thread 1506 * switch-in actions. 1507 */ 1508 1509 (void) (*md->pmd_switch_in)(pc, pp); 1510 1511 critical_exit(); 1512 1513 } 1514 1515 /* 1516 * Thread context switch OUT. 1517 */ 1518 1519 static void 1520 pmc_process_csw_out(struct thread *td) 1521 { 1522 int cpu; 1523 int64_t tmp; 1524 struct pmc *pm; 1525 struct proc *p; 1526 enum pmc_mode mode; 1527 struct pmc_cpu *pc; 1528 pmc_value_t newvalue; 1529 unsigned int adjri, ri; 1530 struct pmc_process *pp; 1531 struct pmc_thread *pt = NULL; 1532 struct pmc_classdep *pcd; 1533 1534 1535 /* 1536 * Locate our process descriptor; this may be NULL if 1537 * this process is exiting and we have already removed 1538 * the process from the target process table. 1539 * 1540 * Note that due to kernel preemption, multiple 1541 * context switches may happen while the process is 1542 * exiting. 1543 * 1544 * Note also that if the target process cannot be 1545 * found we still need to deconfigure any PMCs that 1546 * are currently running on hardware. 1547 */ 1548 1549 p = td->td_proc; 1550 pp = pmc_find_process_descriptor(p, PMC_FLAG_NONE); 1551 1552 /* 1553 * save PMCs 1554 */ 1555 1556 critical_enter(); 1557 1558 cpu = PCPU_GET(cpuid); /* td->td_oncpu is invalid */ 1559 1560 PMCDBG5(CSW,SWO,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p, 1561 p->p_pid, p->p_comm, pp); 1562 1563 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 1564 ("[pmc,%d weird CPU id %d", __LINE__, cpu)); 1565 1566 pc = pmc_pcpu[cpu]; 1567 1568 /* 1569 * When a PMC gets unlinked from a target PMC, it will 1570 * be removed from the target's pp_pmc[] array. 1571 * 1572 * However, on a MP system, the target could have been 1573 * executing on another CPU at the time of the unlink. 1574 * So, at context switch OUT time, we need to look at 1575 * the hardware to determine if a PMC is scheduled on 1576 * it. 1577 */ 1578 1579 for (ri = 0; ri < md->pmd_npmc; ri++) { 1580 1581 pcd = pmc_ri_to_classdep(md, ri, &adjri); 1582 pm = NULL; 1583 (void) (*pcd->pcd_get_config)(cpu, adjri, &pm); 1584 1585 if (pm == NULL) /* nothing at this row index */ 1586 continue; 1587 1588 mode = PMC_TO_MODE(pm); 1589 if (!PMC_IS_VIRTUAL_MODE(mode)) 1590 continue; /* not a process virtual PMC */ 1591 1592 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 1593 ("[pmc,%d] ri mismatch pmc(%d) ri(%d)", 1594 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 1595 1596 /* 1597 * Change desired state, and then stop if not stalled. 1598 * This two-step dance should avoid race conditions where 1599 * an interrupt re-enables the PMC after this code has 1600 * already checked the pm_stalled flag. 1601 */ 1602 pm->pm_pcpu_state[cpu].pps_cpustate = 0; 1603 if (pm->pm_pcpu_state[cpu].pps_stalled == 0) 1604 pcd->pcd_stop_pmc(cpu, adjri, pm); 1605 1606 KASSERT(counter_u64_fetch(pm->pm_runcount) > 0, 1607 ("[pmc,%d] pm=%p runcount %ld", __LINE__, (void *) pm, 1608 (unsigned long)counter_u64_fetch(pm->pm_runcount))); 1609 1610 /* reduce this PMC's runcount */ 1611 counter_u64_add(pm->pm_runcount, -1); 1612 1613 /* 1614 * If this PMC is associated with this process, 1615 * save the reading. 1616 */ 1617 1618 if (pm->pm_state != PMC_STATE_DELETED && pp != NULL && 1619 pp->pp_pmcs[ri].pp_pmc != NULL) { 1620 KASSERT(pm == pp->pp_pmcs[ri].pp_pmc, 1621 ("[pmc,%d] pm %p != pp_pmcs[%d] %p", __LINE__, 1622 pm, ri, pp->pp_pmcs[ri].pp_pmc)); 1623 1624 KASSERT(pp->pp_refcnt > 0, 1625 ("[pmc,%d] pp refcnt = %d", __LINE__, 1626 pp->pp_refcnt)); 1627 1628 pcd->pcd_read_pmc(cpu, adjri, pm, &newvalue); 1629 1630 if (mode == PMC_MODE_TS) { 1631 PMCDBG3(CSW,SWO,1,"cpu=%d ri=%d val=%jd (samp)", 1632 cpu, ri, newvalue); 1633 1634 if (pt == NULL) 1635 pt = pmc_find_thread_descriptor(pp, td, 1636 PMC_FLAG_NONE); 1637 1638 KASSERT(pt != NULL, 1639 ("[pmc,%d] No thread found for td=%p", 1640 __LINE__, td)); 1641 1642 mtx_pool_lock_spin(pmc_mtxpool, pm); 1643 1644 /* 1645 * If we have a thread descriptor, save the 1646 * per-thread counter in the descriptor. If not, 1647 * we will update the per-process counter. 1648 * 1649 * TODO: Remove the per-process "safety net" 1650 * once we have thoroughly tested that we 1651 * don't hit the above assert. 1652 */ 1653 if (pt != NULL) 1654 pt->pt_pmcs[ri].pt_pmcval = newvalue; 1655 else { 1656 /* 1657 * For sampling process-virtual PMCs, 1658 * newvalue is the number of events to 1659 * be seen until the next sampling 1660 * interrupt. We can just add the events 1661 * left from this invocation to the 1662 * counter, then adjust in case we 1663 * overflow our range. 1664 * 1665 * (Recall that we reload the counter 1666 * every time we use it.) 1667 */ 1668 pp->pp_pmcs[ri].pp_pmcval += newvalue; 1669 if (pp->pp_pmcs[ri].pp_pmcval > 1670 pm->pm_sc.pm_reloadcount) 1671 pp->pp_pmcs[ri].pp_pmcval -= 1672 pm->pm_sc.pm_reloadcount; 1673 } 1674 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1675 } else { 1676 tmp = newvalue - PMC_PCPU_SAVED(cpu,ri); 1677 1678 PMCDBG3(CSW,SWO,1,"cpu=%d ri=%d tmp=%jd (count)", 1679 cpu, ri, tmp); 1680 1681 /* 1682 * For counting process-virtual PMCs, 1683 * we expect the count to be 1684 * increasing monotonically, modulo a 64 1685 * bit wraparound. 1686 */ 1687 KASSERT(tmp >= 0, 1688 ("[pmc,%d] negative increment cpu=%d " 1689 "ri=%d newvalue=%jx saved=%jx " 1690 "incr=%jx", __LINE__, cpu, ri, 1691 newvalue, PMC_PCPU_SAVED(cpu,ri), tmp)); 1692 1693 mtx_pool_lock_spin(pmc_mtxpool, pm); 1694 pm->pm_gv.pm_savedvalue += tmp; 1695 pp->pp_pmcs[ri].pp_pmcval += tmp; 1696 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1697 1698 if (pm->pm_flags & PMC_F_LOG_PROCCSW) 1699 pmclog_process_proccsw(pm, pp, tmp, td); 1700 } 1701 } 1702 1703 /* mark hardware as free */ 1704 pcd->pcd_config_pmc(cpu, adjri, NULL); 1705 } 1706 1707 /* 1708 * perform any other architecture/cpu dependent thread 1709 * switch out functions. 1710 */ 1711 1712 (void) (*md->pmd_switch_out)(pc, pp); 1713 1714 critical_exit(); 1715 } 1716 1717 /* 1718 * A new thread for a process. 1719 */ 1720 static void 1721 pmc_process_thread_add(struct thread *td) 1722 { 1723 struct pmc_process *pmc; 1724 1725 pmc = pmc_find_process_descriptor(td->td_proc, PMC_FLAG_NONE); 1726 if (pmc != NULL) 1727 pmc_find_thread_descriptor(pmc, td, PMC_FLAG_ALLOCATE); 1728 } 1729 1730 /* 1731 * A thread delete for a process. 1732 */ 1733 static void 1734 pmc_process_thread_delete(struct thread *td) 1735 { 1736 struct pmc_process *pmc; 1737 1738 pmc = pmc_find_process_descriptor(td->td_proc, PMC_FLAG_NONE); 1739 if (pmc != NULL) 1740 pmc_thread_descriptor_pool_free(pmc_find_thread_descriptor(pmc, 1741 td, PMC_FLAG_REMOVE)); 1742 } 1743 1744 /* 1745 * A userret() call for a thread. 1746 */ 1747 static void 1748 pmc_process_thread_userret(struct thread *td) 1749 { 1750 sched_pin(); 1751 pmc_capture_user_callchain(curcpu, PMC_UR, td->td_frame); 1752 sched_unpin(); 1753 } 1754 1755 /* 1756 * A mapping change for a process. 1757 */ 1758 1759 static void 1760 pmc_process_mmap(struct thread *td, struct pmckern_map_in *pkm) 1761 { 1762 int ri; 1763 pid_t pid; 1764 char *fullpath, *freepath; 1765 const struct pmc *pm; 1766 struct pmc_owner *po; 1767 const struct pmc_process *pp; 1768 1769 freepath = fullpath = NULL; 1770 MPASS(!in_epoch(global_epoch_preempt)); 1771 pmc_getfilename((struct vnode *) pkm->pm_file, &fullpath, &freepath); 1772 1773 pid = td->td_proc->p_pid; 1774 1775 PMC_EPOCH_ENTER(); 1776 /* Inform owners of all system-wide sampling PMCs. */ 1777 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1778 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1779 pmclog_process_map_in(po, pid, pkm->pm_address, fullpath); 1780 1781 if ((pp = pmc_find_process_descriptor(td->td_proc, 0)) == NULL) 1782 goto done; 1783 1784 /* 1785 * Inform sampling PMC owners tracking this process. 1786 */ 1787 for (ri = 0; ri < md->pmd_npmc; ri++) 1788 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL && 1789 PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 1790 pmclog_process_map_in(pm->pm_owner, 1791 pid, pkm->pm_address, fullpath); 1792 1793 done: 1794 if (freepath) 1795 free(freepath, M_TEMP); 1796 PMC_EPOCH_EXIT(); 1797 } 1798 1799 1800 /* 1801 * Log an munmap request. 1802 */ 1803 1804 static void 1805 pmc_process_munmap(struct thread *td, struct pmckern_map_out *pkm) 1806 { 1807 int ri; 1808 pid_t pid; 1809 struct pmc_owner *po; 1810 const struct pmc *pm; 1811 const struct pmc_process *pp; 1812 1813 pid = td->td_proc->p_pid; 1814 1815 PMC_EPOCH_ENTER(); 1816 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1817 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1818 pmclog_process_map_out(po, pid, pkm->pm_address, 1819 pkm->pm_address + pkm->pm_size); 1820 PMC_EPOCH_EXIT(); 1821 1822 if ((pp = pmc_find_process_descriptor(td->td_proc, 0)) == NULL) 1823 return; 1824 1825 for (ri = 0; ri < md->pmd_npmc; ri++) 1826 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL && 1827 PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 1828 pmclog_process_map_out(pm->pm_owner, pid, 1829 pkm->pm_address, pkm->pm_address + pkm->pm_size); 1830 } 1831 1832 /* 1833 * Log mapping information about the kernel. 1834 */ 1835 1836 static void 1837 pmc_log_kernel_mappings(struct pmc *pm) 1838 { 1839 struct pmc_owner *po; 1840 struct pmckern_map_in *km, *kmbase; 1841 1842 MPASS(in_epoch(global_epoch_preempt) || sx_xlocked(&pmc_sx)); 1843 KASSERT(PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)), 1844 ("[pmc,%d] non-sampling PMC (%p) desires mapping information", 1845 __LINE__, (void *) pm)); 1846 1847 po = pm->pm_owner; 1848 1849 if (po->po_flags & PMC_PO_INITIAL_MAPPINGS_DONE) 1850 return; 1851 if (PMC_TO_MODE(pm) == PMC_MODE_SS) 1852 pmc_process_allproc(pm); 1853 /* 1854 * Log the current set of kernel modules. 1855 */ 1856 kmbase = linker_hwpmc_list_objects(); 1857 for (km = kmbase; km->pm_file != NULL; km++) { 1858 PMCDBG2(LOG,REG,1,"%s %p", (char *) km->pm_file, 1859 (void *) km->pm_address); 1860 pmclog_process_map_in(po, (pid_t) -1, km->pm_address, 1861 km->pm_file); 1862 } 1863 free(kmbase, M_LINKER); 1864 1865 po->po_flags |= PMC_PO_INITIAL_MAPPINGS_DONE; 1866 } 1867 1868 /* 1869 * Log the mappings for a single process. 1870 */ 1871 1872 static void 1873 pmc_log_process_mappings(struct pmc_owner *po, struct proc *p) 1874 { 1875 vm_map_t map; 1876 struct vnode *vp; 1877 struct vmspace *vm; 1878 vm_map_entry_t entry; 1879 vm_offset_t last_end; 1880 u_int last_timestamp; 1881 struct vnode *last_vp; 1882 vm_offset_t start_addr; 1883 vm_object_t obj, lobj, tobj; 1884 char *fullpath, *freepath; 1885 1886 last_vp = NULL; 1887 last_end = (vm_offset_t) 0; 1888 fullpath = freepath = NULL; 1889 1890 if ((vm = vmspace_acquire_ref(p)) == NULL) 1891 return; 1892 1893 map = &vm->vm_map; 1894 vm_map_lock_read(map); 1895 1896 VM_MAP_ENTRY_FOREACH(entry, map) { 1897 1898 if (entry == NULL) { 1899 PMCDBG2(LOG,OPS,2, "hwpmc: vm_map entry unexpectedly " 1900 "NULL! pid=%d vm_map=%p\n", p->p_pid, map); 1901 break; 1902 } 1903 1904 /* 1905 * We only care about executable map entries. 1906 */ 1907 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) || 1908 !(entry->protection & VM_PROT_EXECUTE) || 1909 (entry->object.vm_object == NULL)) { 1910 continue; 1911 } 1912 1913 obj = entry->object.vm_object; 1914 VM_OBJECT_RLOCK(obj); 1915 1916 /* 1917 * Walk the backing_object list to find the base 1918 * (non-shadowed) vm_object. 1919 */ 1920 for (lobj = tobj = obj; tobj != NULL; tobj = tobj->backing_object) { 1921 if (tobj != obj) 1922 VM_OBJECT_RLOCK(tobj); 1923 if (lobj != obj) 1924 VM_OBJECT_RUNLOCK(lobj); 1925 lobj = tobj; 1926 } 1927 1928 /* 1929 * At this point lobj is the base vm_object and it is locked. 1930 */ 1931 if (lobj == NULL) { 1932 PMCDBG3(LOG,OPS,2, "hwpmc: lobj unexpectedly NULL! pid=%d " 1933 "vm_map=%p vm_obj=%p\n", p->p_pid, map, obj); 1934 VM_OBJECT_RUNLOCK(obj); 1935 continue; 1936 } 1937 1938 vp = vm_object_vnode(lobj); 1939 if (vp == NULL) { 1940 if (lobj != obj) 1941 VM_OBJECT_RUNLOCK(lobj); 1942 VM_OBJECT_RUNLOCK(obj); 1943 continue; 1944 } 1945 1946 /* 1947 * Skip contiguous regions that point to the same 1948 * vnode, so we don't emit redundant MAP-IN 1949 * directives. 1950 */ 1951 if (entry->start == last_end && vp == last_vp) { 1952 last_end = entry->end; 1953 if (lobj != obj) 1954 VM_OBJECT_RUNLOCK(lobj); 1955 VM_OBJECT_RUNLOCK(obj); 1956 continue; 1957 } 1958 1959 /* 1960 * We don't want to keep the proc's vm_map or this 1961 * vm_object locked while we walk the pathname, since 1962 * vn_fullpath() can sleep. However, if we drop the 1963 * lock, it's possible for concurrent activity to 1964 * modify the vm_map list. To protect against this, 1965 * we save the vm_map timestamp before we release the 1966 * lock, and check it after we reacquire the lock 1967 * below. 1968 */ 1969 start_addr = entry->start; 1970 last_end = entry->end; 1971 last_timestamp = map->timestamp; 1972 vm_map_unlock_read(map); 1973 1974 vref(vp); 1975 if (lobj != obj) 1976 VM_OBJECT_RUNLOCK(lobj); 1977 1978 VM_OBJECT_RUNLOCK(obj); 1979 1980 freepath = NULL; 1981 pmc_getfilename(vp, &fullpath, &freepath); 1982 last_vp = vp; 1983 1984 vrele(vp); 1985 1986 vp = NULL; 1987 pmclog_process_map_in(po, p->p_pid, start_addr, fullpath); 1988 if (freepath) 1989 free(freepath, M_TEMP); 1990 1991 vm_map_lock_read(map); 1992 1993 /* 1994 * If our saved timestamp doesn't match, this means 1995 * that the vm_map was modified out from under us and 1996 * we can't trust our current "entry" pointer. Do a 1997 * new lookup for this entry. If there is no entry 1998 * for this address range, vm_map_lookup_entry() will 1999 * return the previous one, so we always want to go to 2000 * the next entry on the next loop iteration. 2001 * 2002 * There is an edge condition here that can occur if 2003 * there is no entry at or before this address. In 2004 * this situation, vm_map_lookup_entry returns 2005 * &map->header, which would cause our loop to abort 2006 * without processing the rest of the map. However, 2007 * in practice this will never happen for process 2008 * vm_map. This is because the executable's text 2009 * segment is the first mapping in the proc's address 2010 * space, and this mapping is never removed until the 2011 * process exits, so there will always be a non-header 2012 * entry at or before the requested address for 2013 * vm_map_lookup_entry to return. 2014 */ 2015 if (map->timestamp != last_timestamp) 2016 vm_map_lookup_entry(map, last_end - 1, &entry); 2017 } 2018 2019 vm_map_unlock_read(map); 2020 vmspace_free(vm); 2021 return; 2022 } 2023 2024 /* 2025 * Log mappings for all processes in the system. 2026 */ 2027 2028 static void 2029 pmc_log_all_process_mappings(struct pmc_owner *po) 2030 { 2031 struct proc *p, *top; 2032 2033 sx_assert(&pmc_sx, SX_XLOCKED); 2034 2035 if ((p = pfind(1)) == NULL) 2036 panic("[pmc,%d] Cannot find init", __LINE__); 2037 2038 PROC_UNLOCK(p); 2039 2040 sx_slock(&proctree_lock); 2041 2042 top = p; 2043 2044 for (;;) { 2045 pmc_log_process_mappings(po, p); 2046 if (!LIST_EMPTY(&p->p_children)) 2047 p = LIST_FIRST(&p->p_children); 2048 else for (;;) { 2049 if (p == top) 2050 goto done; 2051 if (LIST_NEXT(p, p_sibling)) { 2052 p = LIST_NEXT(p, p_sibling); 2053 break; 2054 } 2055 p = p->p_pptr; 2056 } 2057 } 2058 done: 2059 sx_sunlock(&proctree_lock); 2060 } 2061 2062 /* 2063 * The 'hook' invoked from the kernel proper 2064 */ 2065 2066 2067 #ifdef HWPMC_DEBUG 2068 const char *pmc_hooknames[] = { 2069 /* these strings correspond to PMC_FN_* in <sys/pmckern.h> */ 2070 "", 2071 "EXEC", 2072 "CSW-IN", 2073 "CSW-OUT", 2074 "SAMPLE", 2075 "UNUSED1", 2076 "UNUSED2", 2077 "MMAP", 2078 "MUNMAP", 2079 "CALLCHAIN-NMI", 2080 "CALLCHAIN-SOFT", 2081 "SOFTSAMPLING", 2082 "THR-CREATE", 2083 "THR-EXIT", 2084 "THR-USERRET", 2085 "THR-CREATE-LOG", 2086 "THR-EXIT-LOG", 2087 "PROC-CREATE-LOG" 2088 }; 2089 #endif 2090 2091 static int 2092 pmc_hook_handler(struct thread *td, int function, void *arg) 2093 { 2094 int cpu; 2095 2096 PMCDBG4(MOD,PMH,1, "hook td=%p func=%d \"%s\" arg=%p", td, function, 2097 pmc_hooknames[function], arg); 2098 2099 switch (function) 2100 { 2101 2102 /* 2103 * Process exec() 2104 */ 2105 2106 case PMC_FN_PROCESS_EXEC: 2107 { 2108 char *fullpath, *freepath; 2109 unsigned int ri; 2110 int is_using_hwpmcs; 2111 struct pmc *pm; 2112 struct proc *p; 2113 struct pmc_owner *po; 2114 struct pmc_process *pp; 2115 struct pmckern_procexec *pk; 2116 2117 sx_assert(&pmc_sx, SX_XLOCKED); 2118 2119 p = td->td_proc; 2120 pmc_getfilename(p->p_textvp, &fullpath, &freepath); 2121 2122 pk = (struct pmckern_procexec *) arg; 2123 2124 PMC_EPOCH_ENTER(); 2125 /* Inform owners of SS mode PMCs of the exec event. */ 2126 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 2127 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 2128 pmclog_process_procexec(po, PMC_ID_INVALID, 2129 p->p_pid, pk->pm_baseaddr, pk->pm_dynaddr, 2130 fullpath); 2131 PMC_EPOCH_EXIT(); 2132 2133 PROC_LOCK(p); 2134 is_using_hwpmcs = p->p_flag & P_HWPMC; 2135 PROC_UNLOCK(p); 2136 2137 if (!is_using_hwpmcs) { 2138 if (freepath) 2139 free(freepath, M_TEMP); 2140 break; 2141 } 2142 2143 /* 2144 * PMCs are not inherited across an exec(): remove any 2145 * PMCs that this process is the owner of. 2146 */ 2147 2148 if ((po = pmc_find_owner_descriptor(p)) != NULL) { 2149 pmc_remove_owner(po); 2150 pmc_destroy_owner_descriptor(po); 2151 } 2152 2153 /* 2154 * If the process being exec'ed is not the target of any 2155 * PMC, we are done. 2156 */ 2157 if ((pp = pmc_find_process_descriptor(p, 0)) == NULL) { 2158 if (freepath) 2159 free(freepath, M_TEMP); 2160 break; 2161 } 2162 2163 /* 2164 * Log the exec event to all monitoring owners. Skip 2165 * owners who have already received the event because 2166 * they had system sampling PMCs active. 2167 */ 2168 for (ri = 0; ri < md->pmd_npmc; ri++) 2169 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) { 2170 po = pm->pm_owner; 2171 if (po->po_sscount == 0 && 2172 po->po_flags & PMC_PO_OWNS_LOGFILE) 2173 pmclog_process_procexec(po, pm->pm_id, 2174 p->p_pid, pk->pm_baseaddr, 2175 pk->pm_dynaddr, fullpath); 2176 } 2177 2178 if (freepath) 2179 free(freepath, M_TEMP); 2180 2181 2182 PMCDBG4(PRC,EXC,1, "exec proc=%p (%d, %s) cred-changed=%d", 2183 p, p->p_pid, p->p_comm, pk->pm_credentialschanged); 2184 2185 if (pk->pm_credentialschanged == 0) /* no change */ 2186 break; 2187 2188 /* 2189 * If the newly exec()'ed process has a different credential 2190 * than before, allow it to be the target of a PMC only if 2191 * the PMC's owner has sufficient privilege. 2192 */ 2193 2194 for (ri = 0; ri < md->pmd_npmc; ri++) 2195 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) 2196 if (pmc_can_attach(pm, td->td_proc) != 0) 2197 pmc_detach_one_process(td->td_proc, 2198 pm, PMC_FLAG_NONE); 2199 2200 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= (int) md->pmd_npmc, 2201 ("[pmc,%d] Illegal ref count %d on pp %p", __LINE__, 2202 pp->pp_refcnt, pp)); 2203 2204 /* 2205 * If this process is no longer the target of any 2206 * PMCs, we can remove the process entry and free 2207 * up space. 2208 */ 2209 2210 if (pp->pp_refcnt == 0) { 2211 pmc_remove_process_descriptor(pp); 2212 pmc_destroy_process_descriptor(pp); 2213 break; 2214 } 2215 2216 } 2217 break; 2218 2219 case PMC_FN_CSW_IN: 2220 pmc_process_csw_in(td); 2221 break; 2222 2223 case PMC_FN_CSW_OUT: 2224 pmc_process_csw_out(td); 2225 break; 2226 2227 /* 2228 * Process accumulated PC samples. 2229 * 2230 * This function is expected to be called by hardclock() for 2231 * each CPU that has accumulated PC samples. 2232 * 2233 * This function is to be executed on the CPU whose samples 2234 * are being processed. 2235 */ 2236 case PMC_FN_DO_SAMPLES: 2237 2238 /* 2239 * Clear the cpu specific bit in the CPU mask before 2240 * do the rest of the processing. If the NMI handler 2241 * gets invoked after the "atomic_clear_int()" call 2242 * below but before "pmc_process_samples()" gets 2243 * around to processing the interrupt, then we will 2244 * come back here at the next hardclock() tick (and 2245 * may find nothing to do if "pmc_process_samples()" 2246 * had already processed the interrupt). We don't 2247 * lose the interrupt sample. 2248 */ 2249 DPCPU_SET(pmc_sampled, 0); 2250 cpu = PCPU_GET(cpuid); 2251 pmc_process_samples(cpu, PMC_HR); 2252 pmc_process_samples(cpu, PMC_SR); 2253 pmc_process_samples(cpu, PMC_UR); 2254 break; 2255 2256 case PMC_FN_MMAP: 2257 pmc_process_mmap(td, (struct pmckern_map_in *) arg); 2258 break; 2259 2260 case PMC_FN_MUNMAP: 2261 MPASS(in_epoch(global_epoch_preempt) || sx_xlocked(&pmc_sx)); 2262 pmc_process_munmap(td, (struct pmckern_map_out *) arg); 2263 break; 2264 2265 case PMC_FN_PROC_CREATE_LOG: 2266 pmc_process_proccreate((struct proc *)arg); 2267 break; 2268 2269 case PMC_FN_USER_CALLCHAIN: 2270 /* 2271 * Record a call chain. 2272 */ 2273 KASSERT(td == curthread, ("[pmc,%d] td != curthread", 2274 __LINE__)); 2275 2276 pmc_capture_user_callchain(PCPU_GET(cpuid), PMC_HR, 2277 (struct trapframe *) arg); 2278 2279 KASSERT(td->td_pinned == 1, 2280 ("[pmc,%d] invalid td_pinned value", __LINE__)); 2281 sched_unpin(); /* Can migrate safely now. */ 2282 2283 td->td_pflags &= ~TDP_CALLCHAIN; 2284 break; 2285 2286 case PMC_FN_USER_CALLCHAIN_SOFT: 2287 /* 2288 * Record a call chain. 2289 */ 2290 KASSERT(td == curthread, ("[pmc,%d] td != curthread", 2291 __LINE__)); 2292 2293 cpu = PCPU_GET(cpuid); 2294 pmc_capture_user_callchain(cpu, PMC_SR, 2295 (struct trapframe *) arg); 2296 2297 KASSERT(td->td_pinned == 1, 2298 ("[pmc,%d] invalid td_pinned value", __LINE__)); 2299 2300 sched_unpin(); /* Can migrate safely now. */ 2301 2302 td->td_pflags &= ~TDP_CALLCHAIN; 2303 break; 2304 2305 case PMC_FN_SOFT_SAMPLING: 2306 /* 2307 * Call soft PMC sampling intr. 2308 */ 2309 pmc_soft_intr((struct pmckern_soft *) arg); 2310 break; 2311 2312 case PMC_FN_THR_CREATE: 2313 pmc_process_thread_add(td); 2314 pmc_process_threadcreate(td); 2315 break; 2316 2317 case PMC_FN_THR_CREATE_LOG: 2318 pmc_process_threadcreate(td); 2319 break; 2320 2321 case PMC_FN_THR_EXIT: 2322 KASSERT(td == curthread, ("[pmc,%d] td != curthread", 2323 __LINE__)); 2324 pmc_process_thread_delete(td); 2325 pmc_process_threadexit(td); 2326 break; 2327 case PMC_FN_THR_EXIT_LOG: 2328 pmc_process_threadexit(td); 2329 break; 2330 case PMC_FN_THR_USERRET: 2331 KASSERT(td == curthread, ("[pmc,%d] td != curthread", 2332 __LINE__)); 2333 pmc_process_thread_userret(td); 2334 break; 2335 2336 default: 2337 #ifdef HWPMC_DEBUG 2338 KASSERT(0, ("[pmc,%d] unknown hook %d\n", __LINE__, function)); 2339 #endif 2340 break; 2341 2342 } 2343 2344 return 0; 2345 } 2346 2347 /* 2348 * allocate a 'struct pmc_owner' descriptor in the owner hash table. 2349 */ 2350 2351 static struct pmc_owner * 2352 pmc_allocate_owner_descriptor(struct proc *p) 2353 { 2354 uint32_t hindex; 2355 struct pmc_owner *po; 2356 struct pmc_ownerhash *poh; 2357 2358 hindex = PMC_HASH_PTR(p, pmc_ownerhashmask); 2359 poh = &pmc_ownerhash[hindex]; 2360 2361 /* allocate space for N pointers and one descriptor struct */ 2362 po = malloc(sizeof(struct pmc_owner), M_PMC, M_WAITOK|M_ZERO); 2363 po->po_owner = p; 2364 LIST_INSERT_HEAD(poh, po, po_next); /* insert into hash table */ 2365 2366 TAILQ_INIT(&po->po_logbuffers); 2367 mtx_init(&po->po_mtx, "pmc-owner-mtx", "pmc-per-proc", MTX_SPIN); 2368 2369 PMCDBG4(OWN,ALL,1, "allocate-owner proc=%p (%d, %s) pmc-owner=%p", 2370 p, p->p_pid, p->p_comm, po); 2371 2372 return po; 2373 } 2374 2375 static void 2376 pmc_destroy_owner_descriptor(struct pmc_owner *po) 2377 { 2378 2379 PMCDBG4(OWN,REL,1, "destroy-owner po=%p proc=%p (%d, %s)", 2380 po, po->po_owner, po->po_owner->p_pid, po->po_owner->p_comm); 2381 2382 mtx_destroy(&po->po_mtx); 2383 free(po, M_PMC); 2384 } 2385 2386 /* 2387 * Allocate a thread descriptor from the free pool. 2388 * 2389 * NOTE: This *can* return NULL. 2390 */ 2391 static struct pmc_thread * 2392 pmc_thread_descriptor_pool_alloc(void) 2393 { 2394 struct pmc_thread *pt; 2395 2396 mtx_lock_spin(&pmc_threadfreelist_mtx); 2397 if ((pt = LIST_FIRST(&pmc_threadfreelist)) != NULL) { 2398 LIST_REMOVE(pt, pt_next); 2399 pmc_threadfreelist_entries--; 2400 } 2401 mtx_unlock_spin(&pmc_threadfreelist_mtx); 2402 2403 return (pt); 2404 } 2405 2406 /* 2407 * Add a thread descriptor to the free pool. We use this instead of free() 2408 * to maintain a cache of free entries. Additionally, we can safely call 2409 * this function when we cannot call free(), such as in a critical section. 2410 * 2411 */ 2412 static void 2413 pmc_thread_descriptor_pool_free(struct pmc_thread *pt) 2414 { 2415 2416 if (pt == NULL) 2417 return; 2418 2419 memset(pt, 0, THREADENTRY_SIZE); 2420 mtx_lock_spin(&pmc_threadfreelist_mtx); 2421 LIST_INSERT_HEAD(&pmc_threadfreelist, pt, pt_next); 2422 pmc_threadfreelist_entries++; 2423 if (pmc_threadfreelist_entries > pmc_threadfreelist_max) 2424 taskqueue_enqueue(taskqueue_fast, &free_task); 2425 mtx_unlock_spin(&pmc_threadfreelist_mtx); 2426 } 2427 2428 /* 2429 * An asynchronous task to manage the free list. 2430 */ 2431 static void 2432 pmc_thread_descriptor_pool_free_task(void *arg __unused, int pending __unused) 2433 { 2434 struct pmc_thread *pt; 2435 LIST_HEAD(, pmc_thread) tmplist; 2436 int delta; 2437 2438 LIST_INIT(&tmplist); 2439 2440 /* Determine what changes, if any, we need to make. */ 2441 mtx_lock_spin(&pmc_threadfreelist_mtx); 2442 delta = pmc_threadfreelist_entries - pmc_threadfreelist_max; 2443 while (delta > 0 && (pt = LIST_FIRST(&pmc_threadfreelist)) != NULL) { 2444 delta--; 2445 pmc_threadfreelist_entries--; 2446 LIST_REMOVE(pt, pt_next); 2447 LIST_INSERT_HEAD(&tmplist, pt, pt_next); 2448 } 2449 mtx_unlock_spin(&pmc_threadfreelist_mtx); 2450 2451 /* If there are entries to free, free them. */ 2452 while (!LIST_EMPTY(&tmplist)) { 2453 pt = LIST_FIRST(&tmplist); 2454 LIST_REMOVE(pt, pt_next); 2455 free(pt, M_PMC); 2456 } 2457 } 2458 2459 /* 2460 * Drain the thread free pool, freeing all allocations. 2461 */ 2462 static void 2463 pmc_thread_descriptor_pool_drain(void) 2464 { 2465 struct pmc_thread *pt, *next; 2466 2467 LIST_FOREACH_SAFE(pt, &pmc_threadfreelist, pt_next, next) { 2468 LIST_REMOVE(pt, pt_next); 2469 free(pt, M_PMC); 2470 } 2471 } 2472 2473 /* 2474 * find the descriptor corresponding to thread 'td', adding or removing it 2475 * as specified by 'mode'. 2476 * 2477 * Note that this supports additional mode flags in addition to those 2478 * supported by pmc_find_process_descriptor(): 2479 * PMC_FLAG_NOWAIT: Causes the function to not wait for mallocs. 2480 * This makes it safe to call while holding certain other locks. 2481 */ 2482 2483 static struct pmc_thread * 2484 pmc_find_thread_descriptor(struct pmc_process *pp, struct thread *td, 2485 uint32_t mode) 2486 { 2487 struct pmc_thread *pt = NULL, *ptnew = NULL; 2488 int wait_flag; 2489 2490 KASSERT(td != NULL, ("[pmc,%d] called to add NULL td", __LINE__)); 2491 2492 /* 2493 * Pre-allocate memory in the PMC_FLAG_ALLOCATE case prior to 2494 * acquiring the lock. 2495 */ 2496 if (mode & PMC_FLAG_ALLOCATE) { 2497 if ((ptnew = pmc_thread_descriptor_pool_alloc()) == NULL) { 2498 wait_flag = M_WAITOK; 2499 if ((mode & PMC_FLAG_NOWAIT) || in_epoch(global_epoch_preempt)) 2500 wait_flag = M_NOWAIT; 2501 2502 ptnew = malloc(THREADENTRY_SIZE, M_PMC, 2503 wait_flag|M_ZERO); 2504 } 2505 } 2506 2507 mtx_lock_spin(pp->pp_tdslock); 2508 2509 LIST_FOREACH(pt, &pp->pp_tds, pt_next) 2510 if (pt->pt_td == td) 2511 break; 2512 2513 if ((mode & PMC_FLAG_REMOVE) && pt != NULL) 2514 LIST_REMOVE(pt, pt_next); 2515 2516 if ((mode & PMC_FLAG_ALLOCATE) && pt == NULL && ptnew != NULL) { 2517 pt = ptnew; 2518 ptnew = NULL; 2519 pt->pt_td = td; 2520 LIST_INSERT_HEAD(&pp->pp_tds, pt, pt_next); 2521 } 2522 2523 mtx_unlock_spin(pp->pp_tdslock); 2524 2525 if (ptnew != NULL) { 2526 free(ptnew, M_PMC); 2527 } 2528 2529 return pt; 2530 } 2531 2532 /* 2533 * Try to add thread descriptors for each thread in a process. 2534 */ 2535 2536 static void 2537 pmc_add_thread_descriptors_from_proc(struct proc *p, struct pmc_process *pp) 2538 { 2539 struct thread *curtd; 2540 struct pmc_thread **tdlist; 2541 int i, tdcnt, tdlistsz; 2542 2543 KASSERT(!PROC_LOCKED(p), ("[pmc,%d] proc unexpectedly locked", 2544 __LINE__)); 2545 tdcnt = 32; 2546 restart: 2547 tdlistsz = roundup2(tdcnt, 32); 2548 2549 tdcnt = 0; 2550 tdlist = malloc(sizeof(struct pmc_thread*) * tdlistsz, M_TEMP, M_WAITOK); 2551 2552 PROC_LOCK(p); 2553 FOREACH_THREAD_IN_PROC(p, curtd) 2554 tdcnt++; 2555 if (tdcnt >= tdlistsz) { 2556 PROC_UNLOCK(p); 2557 free(tdlist, M_TEMP); 2558 goto restart; 2559 } 2560 /* 2561 * Try to add each thread to the list without sleeping. If unable, 2562 * add to a queue to retry after dropping the process lock. 2563 */ 2564 tdcnt = 0; 2565 FOREACH_THREAD_IN_PROC(p, curtd) { 2566 tdlist[tdcnt] = pmc_find_thread_descriptor(pp, curtd, 2567 PMC_FLAG_ALLOCATE|PMC_FLAG_NOWAIT); 2568 if (tdlist[tdcnt] == NULL) { 2569 PROC_UNLOCK(p); 2570 for (i = 0; i <= tdcnt; i++) 2571 pmc_thread_descriptor_pool_free(tdlist[i]); 2572 free(tdlist, M_TEMP); 2573 goto restart; 2574 } 2575 tdcnt++; 2576 } 2577 PROC_UNLOCK(p); 2578 free(tdlist, M_TEMP); 2579 } 2580 2581 /* 2582 * find the descriptor corresponding to process 'p', adding or removing it 2583 * as specified by 'mode'. 2584 */ 2585 2586 static struct pmc_process * 2587 pmc_find_process_descriptor(struct proc *p, uint32_t mode) 2588 { 2589 uint32_t hindex; 2590 struct pmc_process *pp, *ppnew; 2591 struct pmc_processhash *pph; 2592 2593 hindex = PMC_HASH_PTR(p, pmc_processhashmask); 2594 pph = &pmc_processhash[hindex]; 2595 2596 ppnew = NULL; 2597 2598 /* 2599 * Pre-allocate memory in the PMC_FLAG_ALLOCATE case since we 2600 * cannot call malloc(9) once we hold a spin lock. 2601 */ 2602 if (mode & PMC_FLAG_ALLOCATE) 2603 ppnew = malloc(sizeof(struct pmc_process) + md->pmd_npmc * 2604 sizeof(struct pmc_targetstate), M_PMC, M_WAITOK|M_ZERO); 2605 2606 mtx_lock_spin(&pmc_processhash_mtx); 2607 LIST_FOREACH(pp, pph, pp_next) 2608 if (pp->pp_proc == p) 2609 break; 2610 2611 if ((mode & PMC_FLAG_REMOVE) && pp != NULL) 2612 LIST_REMOVE(pp, pp_next); 2613 2614 if ((mode & PMC_FLAG_ALLOCATE) && pp == NULL && 2615 ppnew != NULL) { 2616 ppnew->pp_proc = p; 2617 LIST_INIT(&ppnew->pp_tds); 2618 ppnew->pp_tdslock = mtx_pool_find(pmc_mtxpool, ppnew); 2619 LIST_INSERT_HEAD(pph, ppnew, pp_next); 2620 mtx_unlock_spin(&pmc_processhash_mtx); 2621 pp = ppnew; 2622 ppnew = NULL; 2623 2624 /* Add thread descriptors for this process' current threads. */ 2625 pmc_add_thread_descriptors_from_proc(p, pp); 2626 } 2627 else 2628 mtx_unlock_spin(&pmc_processhash_mtx); 2629 2630 if (ppnew != NULL) 2631 free(ppnew, M_PMC); 2632 2633 return pp; 2634 } 2635 2636 /* 2637 * remove a process descriptor from the process hash table. 2638 */ 2639 2640 static void 2641 pmc_remove_process_descriptor(struct pmc_process *pp) 2642 { 2643 KASSERT(pp->pp_refcnt == 0, 2644 ("[pmc,%d] Removing process descriptor %p with count %d", 2645 __LINE__, pp, pp->pp_refcnt)); 2646 2647 mtx_lock_spin(&pmc_processhash_mtx); 2648 LIST_REMOVE(pp, pp_next); 2649 mtx_unlock_spin(&pmc_processhash_mtx); 2650 } 2651 2652 /* 2653 * destroy a process descriptor. 2654 */ 2655 2656 static void 2657 pmc_destroy_process_descriptor(struct pmc_process *pp) 2658 { 2659 struct pmc_thread *pmc_td; 2660 2661 while ((pmc_td = LIST_FIRST(&pp->pp_tds)) != NULL) { 2662 LIST_REMOVE(pmc_td, pt_next); 2663 pmc_thread_descriptor_pool_free(pmc_td); 2664 } 2665 free(pp, M_PMC); 2666 } 2667 2668 2669 /* 2670 * find an owner descriptor corresponding to proc 'p' 2671 */ 2672 2673 static struct pmc_owner * 2674 pmc_find_owner_descriptor(struct proc *p) 2675 { 2676 uint32_t hindex; 2677 struct pmc_owner *po; 2678 struct pmc_ownerhash *poh; 2679 2680 hindex = PMC_HASH_PTR(p, pmc_ownerhashmask); 2681 poh = &pmc_ownerhash[hindex]; 2682 2683 po = NULL; 2684 LIST_FOREACH(po, poh, po_next) 2685 if (po->po_owner == p) 2686 break; 2687 2688 PMCDBG5(OWN,FND,1, "find-owner proc=%p (%d, %s) hindex=0x%x -> " 2689 "pmc-owner=%p", p, p->p_pid, p->p_comm, hindex, po); 2690 2691 return po; 2692 } 2693 2694 /* 2695 * pmc_allocate_pmc_descriptor 2696 * 2697 * Allocate a pmc descriptor and initialize its 2698 * fields. 2699 */ 2700 2701 static struct pmc * 2702 pmc_allocate_pmc_descriptor(void) 2703 { 2704 struct pmc *pmc; 2705 2706 pmc = malloc(sizeof(struct pmc), M_PMC, M_WAITOK|M_ZERO); 2707 pmc->pm_runcount = counter_u64_alloc(M_WAITOK); 2708 pmc->pm_pcpu_state = malloc(sizeof(struct pmc_pcpu_state)*mp_ncpus, M_PMC, M_WAITOK|M_ZERO); 2709 PMCDBG1(PMC,ALL,1, "allocate-pmc -> pmc=%p", pmc); 2710 2711 return pmc; 2712 } 2713 2714 /* 2715 * Destroy a pmc descriptor. 2716 */ 2717 2718 static void 2719 pmc_destroy_pmc_descriptor(struct pmc *pm) 2720 { 2721 2722 KASSERT(pm->pm_state == PMC_STATE_DELETED || 2723 pm->pm_state == PMC_STATE_FREE, 2724 ("[pmc,%d] destroying non-deleted PMC", __LINE__)); 2725 KASSERT(LIST_EMPTY(&pm->pm_targets), 2726 ("[pmc,%d] destroying pmc with targets", __LINE__)); 2727 KASSERT(pm->pm_owner == NULL, 2728 ("[pmc,%d] destroying pmc attached to an owner", __LINE__)); 2729 KASSERT(counter_u64_fetch(pm->pm_runcount) == 0, 2730 ("[pmc,%d] pmc has non-zero run count %ld", __LINE__, 2731 (unsigned long)counter_u64_fetch(pm->pm_runcount))); 2732 2733 counter_u64_free(pm->pm_runcount); 2734 free(pm->pm_pcpu_state, M_PMC); 2735 free(pm, M_PMC); 2736 } 2737 2738 static void 2739 pmc_wait_for_pmc_idle(struct pmc *pm) 2740 { 2741 #ifdef INVARIANTS 2742 volatile int maxloop; 2743 2744 maxloop = 100 * pmc_cpu_max(); 2745 #endif 2746 /* 2747 * Loop (with a forced context switch) till the PMC's runcount 2748 * comes down to zero. 2749 */ 2750 pmclog_flush(pm->pm_owner, 1); 2751 while (counter_u64_fetch(pm->pm_runcount) > 0) { 2752 pmclog_flush(pm->pm_owner, 1); 2753 #ifdef INVARIANTS 2754 maxloop--; 2755 KASSERT(maxloop > 0, 2756 ("[pmc,%d] (ri%d, rc%ld) waiting too long for " 2757 "pmc to be free", __LINE__, 2758 PMC_TO_ROWINDEX(pm), (unsigned long)counter_u64_fetch(pm->pm_runcount))); 2759 #endif 2760 pmc_force_context_switch(); 2761 } 2762 } 2763 2764 /* 2765 * This function does the following things: 2766 * 2767 * - detaches the PMC from hardware 2768 * - unlinks all target threads that were attached to it 2769 * - removes the PMC from its owner's list 2770 * - destroys the PMC private mutex 2771 * 2772 * Once this function completes, the given pmc pointer can be freed by 2773 * calling pmc_destroy_pmc_descriptor(). 2774 */ 2775 2776 static void 2777 pmc_release_pmc_descriptor(struct pmc *pm) 2778 { 2779 enum pmc_mode mode; 2780 struct pmc_hw *phw __diagused; 2781 u_int adjri, ri, cpu; 2782 struct pmc_owner *po; 2783 struct pmc_binding pb; 2784 struct pmc_process *pp; 2785 struct pmc_classdep *pcd; 2786 struct pmc_target *ptgt, *tmp; 2787 2788 sx_assert(&pmc_sx, SX_XLOCKED); 2789 2790 KASSERT(pm, ("[pmc,%d] null pmc", __LINE__)); 2791 2792 ri = PMC_TO_ROWINDEX(pm); 2793 pcd = pmc_ri_to_classdep(md, ri, &adjri); 2794 mode = PMC_TO_MODE(pm); 2795 2796 PMCDBG3(PMC,REL,1, "release-pmc pmc=%p ri=%d mode=%d", pm, ri, 2797 mode); 2798 2799 /* 2800 * First, we take the PMC off hardware. 2801 */ 2802 cpu = 0; 2803 if (PMC_IS_SYSTEM_MODE(mode)) { 2804 2805 /* 2806 * A system mode PMC runs on a specific CPU. Switch 2807 * to this CPU and turn hardware off. 2808 */ 2809 pmc_save_cpu_binding(&pb); 2810 2811 cpu = PMC_TO_CPU(pm); 2812 2813 pmc_select_cpu(cpu); 2814 2815 /* switch off non-stalled CPUs */ 2816 pm->pm_pcpu_state[cpu].pps_cpustate = 0; 2817 if (pm->pm_state == PMC_STATE_RUNNING && 2818 pm->pm_pcpu_state[cpu].pps_stalled == 0) { 2819 2820 phw = pmc_pcpu[cpu]->pc_hwpmcs[ri]; 2821 2822 KASSERT(phw->phw_pmc == pm, 2823 ("[pmc, %d] pmc ptr ri(%d) hw(%p) pm(%p)", 2824 __LINE__, ri, phw->phw_pmc, pm)); 2825 PMCDBG2(PMC,REL,2, "stopping cpu=%d ri=%d", cpu, ri); 2826 2827 critical_enter(); 2828 pcd->pcd_stop_pmc(cpu, adjri, pm); 2829 critical_exit(); 2830 } 2831 2832 PMCDBG2(PMC,REL,2, "decfg cpu=%d ri=%d", cpu, ri); 2833 2834 critical_enter(); 2835 pcd->pcd_config_pmc(cpu, adjri, NULL); 2836 critical_exit(); 2837 2838 /* adjust the global and process count of SS mode PMCs */ 2839 if (mode == PMC_MODE_SS && pm->pm_state == PMC_STATE_RUNNING) { 2840 po = pm->pm_owner; 2841 po->po_sscount--; 2842 if (po->po_sscount == 0) { 2843 atomic_subtract_rel_int(&pmc_ss_count, 1); 2844 CK_LIST_REMOVE(po, po_ssnext); 2845 epoch_wait_preempt(global_epoch_preempt); 2846 } 2847 } 2848 2849 pm->pm_state = PMC_STATE_DELETED; 2850 2851 pmc_restore_cpu_binding(&pb); 2852 2853 /* 2854 * We could have references to this PMC structure in 2855 * the per-cpu sample queues. Wait for the queue to 2856 * drain. 2857 */ 2858 pmc_wait_for_pmc_idle(pm); 2859 2860 } else if (PMC_IS_VIRTUAL_MODE(mode)) { 2861 2862 /* 2863 * A virtual PMC could be running on multiple CPUs at 2864 * a given instant. 2865 * 2866 * By marking its state as DELETED, we ensure that 2867 * this PMC is never further scheduled on hardware. 2868 * 2869 * Then we wait till all CPUs are done with this PMC. 2870 */ 2871 pm->pm_state = PMC_STATE_DELETED; 2872 2873 2874 /* Wait for the PMCs runcount to come to zero. */ 2875 pmc_wait_for_pmc_idle(pm); 2876 2877 /* 2878 * At this point the PMC is off all CPUs and cannot be 2879 * freshly scheduled onto a CPU. It is now safe to 2880 * unlink all targets from this PMC. If a 2881 * process-record's refcount falls to zero, we remove 2882 * it from the hash table. The module-wide SX lock 2883 * protects us from races. 2884 */ 2885 LIST_FOREACH_SAFE(ptgt, &pm->pm_targets, pt_next, tmp) { 2886 pp = ptgt->pt_process; 2887 pmc_unlink_target_process(pm, pp); /* frees 'ptgt' */ 2888 2889 PMCDBG1(PMC,REL,3, "pp->refcnt=%d", pp->pp_refcnt); 2890 2891 /* 2892 * If the target process record shows that no 2893 * PMCs are attached to it, reclaim its space. 2894 */ 2895 2896 if (pp->pp_refcnt == 0) { 2897 pmc_remove_process_descriptor(pp); 2898 pmc_destroy_process_descriptor(pp); 2899 } 2900 } 2901 2902 cpu = curthread->td_oncpu; /* setup cpu for pmd_release() */ 2903 2904 } 2905 2906 /* 2907 * Release any MD resources 2908 */ 2909 (void) pcd->pcd_release_pmc(cpu, adjri, pm); 2910 2911 /* 2912 * Update row disposition 2913 */ 2914 2915 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) 2916 PMC_UNMARK_ROW_STANDALONE(ri); 2917 else 2918 PMC_UNMARK_ROW_THREAD(ri); 2919 2920 /* unlink from the owner's list */ 2921 if (pm->pm_owner) { 2922 LIST_REMOVE(pm, pm_next); 2923 pm->pm_owner = NULL; 2924 } 2925 } 2926 2927 /* 2928 * Register an owner and a pmc. 2929 */ 2930 2931 static int 2932 pmc_register_owner(struct proc *p, struct pmc *pmc) 2933 { 2934 struct pmc_owner *po; 2935 2936 sx_assert(&pmc_sx, SX_XLOCKED); 2937 2938 if ((po = pmc_find_owner_descriptor(p)) == NULL) 2939 if ((po = pmc_allocate_owner_descriptor(p)) == NULL) 2940 return ENOMEM; 2941 2942 KASSERT(pmc->pm_owner == NULL, 2943 ("[pmc,%d] attempting to own an initialized PMC", __LINE__)); 2944 pmc->pm_owner = po; 2945 2946 LIST_INSERT_HEAD(&po->po_pmcs, pmc, pm_next); 2947 2948 PROC_LOCK(p); 2949 p->p_flag |= P_HWPMC; 2950 PROC_UNLOCK(p); 2951 2952 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 2953 pmclog_process_pmcallocate(pmc); 2954 2955 PMCDBG2(PMC,REG,1, "register-owner pmc-owner=%p pmc=%p", 2956 po, pmc); 2957 2958 return 0; 2959 } 2960 2961 /* 2962 * Return the current row disposition: 2963 * == 0 => FREE 2964 * > 0 => PROCESS MODE 2965 * < 0 => SYSTEM MODE 2966 */ 2967 2968 int 2969 pmc_getrowdisp(int ri) 2970 { 2971 return pmc_pmcdisp[ri]; 2972 } 2973 2974 /* 2975 * Check if a PMC at row index 'ri' can be allocated to the current 2976 * process. 2977 * 2978 * Allocation can fail if: 2979 * - the current process is already being profiled by a PMC at index 'ri', 2980 * attached to it via OP_PMCATTACH. 2981 * - the current process has already allocated a PMC at index 'ri' 2982 * via OP_ALLOCATE. 2983 */ 2984 2985 static int 2986 pmc_can_allocate_rowindex(struct proc *p, unsigned int ri, int cpu) 2987 { 2988 enum pmc_mode mode; 2989 struct pmc *pm; 2990 struct pmc_owner *po; 2991 struct pmc_process *pp; 2992 2993 PMCDBG5(PMC,ALR,1, "can-allocate-rowindex proc=%p (%d, %s) ri=%d " 2994 "cpu=%d", p, p->p_pid, p->p_comm, ri, cpu); 2995 2996 /* 2997 * We shouldn't have already allocated a process-mode PMC at 2998 * row index 'ri'. 2999 * 3000 * We shouldn't have allocated a system-wide PMC on the same 3001 * CPU and same RI. 3002 */ 3003 if ((po = pmc_find_owner_descriptor(p)) != NULL) 3004 LIST_FOREACH(pm, &po->po_pmcs, pm_next) { 3005 if (PMC_TO_ROWINDEX(pm) == ri) { 3006 mode = PMC_TO_MODE(pm); 3007 if (PMC_IS_VIRTUAL_MODE(mode)) 3008 return EEXIST; 3009 if (PMC_IS_SYSTEM_MODE(mode) && 3010 (int) PMC_TO_CPU(pm) == cpu) 3011 return EEXIST; 3012 } 3013 } 3014 3015 /* 3016 * We also shouldn't be the target of any PMC at this index 3017 * since otherwise a PMC_ATTACH to ourselves will fail. 3018 */ 3019 if ((pp = pmc_find_process_descriptor(p, 0)) != NULL) 3020 if (pp->pp_pmcs[ri].pp_pmc) 3021 return EEXIST; 3022 3023 PMCDBG4(PMC,ALR,2, "can-allocate-rowindex proc=%p (%d, %s) ri=%d ok", 3024 p, p->p_pid, p->p_comm, ri); 3025 3026 return 0; 3027 } 3028 3029 /* 3030 * Check if a given PMC at row index 'ri' can be currently used in 3031 * mode 'mode'. 3032 */ 3033 3034 static int 3035 pmc_can_allocate_row(int ri, enum pmc_mode mode) 3036 { 3037 enum pmc_disp disp; 3038 3039 sx_assert(&pmc_sx, SX_XLOCKED); 3040 3041 PMCDBG2(PMC,ALR,1, "can-allocate-row ri=%d mode=%d", ri, mode); 3042 3043 if (PMC_IS_SYSTEM_MODE(mode)) 3044 disp = PMC_DISP_STANDALONE; 3045 else 3046 disp = PMC_DISP_THREAD; 3047 3048 /* 3049 * check disposition for PMC row 'ri': 3050 * 3051 * Expected disposition Row-disposition Result 3052 * 3053 * STANDALONE STANDALONE or FREE proceed 3054 * STANDALONE THREAD fail 3055 * THREAD THREAD or FREE proceed 3056 * THREAD STANDALONE fail 3057 */ 3058 3059 if (!PMC_ROW_DISP_IS_FREE(ri) && 3060 !(disp == PMC_DISP_THREAD && PMC_ROW_DISP_IS_THREAD(ri)) && 3061 !(disp == PMC_DISP_STANDALONE && PMC_ROW_DISP_IS_STANDALONE(ri))) 3062 return EBUSY; 3063 3064 /* 3065 * All OK 3066 */ 3067 3068 PMCDBG2(PMC,ALR,2, "can-allocate-row ri=%d mode=%d ok", ri, mode); 3069 3070 return 0; 3071 3072 } 3073 3074 /* 3075 * Find a PMC descriptor with user handle 'pmcid' for thread 'td'. 3076 */ 3077 3078 static struct pmc * 3079 pmc_find_pmc_descriptor_in_process(struct pmc_owner *po, pmc_id_t pmcid) 3080 { 3081 struct pmc *pm; 3082 3083 KASSERT(PMC_ID_TO_ROWINDEX(pmcid) < md->pmd_npmc, 3084 ("[pmc,%d] Illegal pmc index %d (max %d)", __LINE__, 3085 PMC_ID_TO_ROWINDEX(pmcid), md->pmd_npmc)); 3086 3087 LIST_FOREACH(pm, &po->po_pmcs, pm_next) 3088 if (pm->pm_id == pmcid) 3089 return pm; 3090 3091 return NULL; 3092 } 3093 3094 static int 3095 pmc_find_pmc(pmc_id_t pmcid, struct pmc **pmc) 3096 { 3097 3098 struct pmc *pm, *opm; 3099 struct pmc_owner *po; 3100 struct pmc_process *pp; 3101 3102 PMCDBG1(PMC,FND,1, "find-pmc id=%d", pmcid); 3103 if (PMC_ID_TO_ROWINDEX(pmcid) >= md->pmd_npmc) 3104 return (EINVAL); 3105 3106 if ((po = pmc_find_owner_descriptor(curthread->td_proc)) == NULL) { 3107 /* 3108 * In case of PMC_F_DESCENDANTS child processes we will not find 3109 * the current process in the owners hash list. Find the owner 3110 * process first and from there lookup the po. 3111 */ 3112 if ((pp = pmc_find_process_descriptor(curthread->td_proc, 3113 PMC_FLAG_NONE)) == NULL) { 3114 return ESRCH; 3115 } else { 3116 opm = pp->pp_pmcs[PMC_ID_TO_ROWINDEX(pmcid)].pp_pmc; 3117 if (opm == NULL) 3118 return ESRCH; 3119 if ((opm->pm_flags & (PMC_F_ATTACHED_TO_OWNER| 3120 PMC_F_DESCENDANTS)) != (PMC_F_ATTACHED_TO_OWNER| 3121 PMC_F_DESCENDANTS)) 3122 return ESRCH; 3123 po = opm->pm_owner; 3124 } 3125 } 3126 3127 if ((pm = pmc_find_pmc_descriptor_in_process(po, pmcid)) == NULL) 3128 return EINVAL; 3129 3130 PMCDBG2(PMC,FND,2, "find-pmc id=%d -> pmc=%p", pmcid, pm); 3131 3132 *pmc = pm; 3133 return 0; 3134 } 3135 3136 /* 3137 * Start a PMC. 3138 */ 3139 3140 static int 3141 pmc_start(struct pmc *pm) 3142 { 3143 enum pmc_mode mode; 3144 struct pmc_owner *po; 3145 struct pmc_binding pb; 3146 struct pmc_classdep *pcd; 3147 int adjri, error, cpu, ri; 3148 3149 KASSERT(pm != NULL, 3150 ("[pmc,%d] null pm", __LINE__)); 3151 3152 mode = PMC_TO_MODE(pm); 3153 ri = PMC_TO_ROWINDEX(pm); 3154 pcd = pmc_ri_to_classdep(md, ri, &adjri); 3155 3156 error = 0; 3157 3158 PMCDBG3(PMC,OPS,1, "start pmc=%p mode=%d ri=%d", pm, mode, ri); 3159 3160 po = pm->pm_owner; 3161 3162 /* 3163 * Disallow PMCSTART if a logfile is required but has not been 3164 * configured yet. 3165 */ 3166 if ((pm->pm_flags & PMC_F_NEEDS_LOGFILE) && 3167 (po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) 3168 return (EDOOFUS); /* programming error */ 3169 3170 /* 3171 * If this is a sampling mode PMC, log mapping information for 3172 * the kernel modules that are currently loaded. 3173 */ 3174 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 3175 pmc_log_kernel_mappings(pm); 3176 3177 if (PMC_IS_VIRTUAL_MODE(mode)) { 3178 3179 /* 3180 * If a PMCATTACH has never been done on this PMC, 3181 * attach it to its owner process. 3182 */ 3183 3184 if (LIST_EMPTY(&pm->pm_targets)) 3185 error = (pm->pm_flags & PMC_F_ATTACH_DONE) ? ESRCH : 3186 pmc_attach_process(po->po_owner, pm); 3187 3188 /* 3189 * If the PMC is attached to its owner, then force a context 3190 * switch to ensure that the MD state gets set correctly. 3191 */ 3192 3193 if (error == 0) { 3194 pm->pm_state = PMC_STATE_RUNNING; 3195 if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) 3196 pmc_force_context_switch(); 3197 } 3198 3199 return (error); 3200 } 3201 3202 3203 /* 3204 * A system-wide PMC. 3205 * 3206 * Add the owner to the global list if this is a system-wide 3207 * sampling PMC. 3208 */ 3209 3210 if (mode == PMC_MODE_SS) { 3211 /* 3212 * Log mapping information for all existing processes in the 3213 * system. Subsequent mappings are logged as they happen; 3214 * see pmc_process_mmap(). 3215 */ 3216 if (po->po_logprocmaps == 0) { 3217 pmc_log_all_process_mappings(po); 3218 po->po_logprocmaps = 1; 3219 } 3220 po->po_sscount++; 3221 if (po->po_sscount == 1) { 3222 atomic_add_rel_int(&pmc_ss_count, 1); 3223 CK_LIST_INSERT_HEAD(&pmc_ss_owners, po, po_ssnext); 3224 PMCDBG1(PMC,OPS,1, "po=%p in global list", po); 3225 } 3226 } 3227 3228 /* 3229 * Move to the CPU associated with this 3230 * PMC, and start the hardware. 3231 */ 3232 3233 pmc_save_cpu_binding(&pb); 3234 3235 cpu = PMC_TO_CPU(pm); 3236 3237 if (!pmc_cpu_is_active(cpu)) 3238 return (ENXIO); 3239 3240 pmc_select_cpu(cpu); 3241 3242 /* 3243 * global PMCs are configured at allocation time 3244 * so write out the initial value and start the PMC. 3245 */ 3246 3247 pm->pm_state = PMC_STATE_RUNNING; 3248 3249 critical_enter(); 3250 if ((error = pcd->pcd_write_pmc(cpu, adjri, pm, 3251 PMC_IS_SAMPLING_MODE(mode) ? 3252 pm->pm_sc.pm_reloadcount : 3253 pm->pm_sc.pm_initial)) == 0) { 3254 /* If a sampling mode PMC, reset stalled state. */ 3255 if (PMC_IS_SAMPLING_MODE(mode)) 3256 pm->pm_pcpu_state[cpu].pps_stalled = 0; 3257 3258 /* Indicate that we desire this to run. Start it. */ 3259 pm->pm_pcpu_state[cpu].pps_cpustate = 1; 3260 error = pcd->pcd_start_pmc(cpu, adjri, pm); 3261 } 3262 critical_exit(); 3263 3264 pmc_restore_cpu_binding(&pb); 3265 3266 return (error); 3267 } 3268 3269 /* 3270 * Stop a PMC. 3271 */ 3272 3273 static int 3274 pmc_stop(struct pmc *pm) 3275 { 3276 struct pmc_owner *po; 3277 struct pmc_binding pb; 3278 struct pmc_classdep *pcd; 3279 int adjri, cpu, error, ri; 3280 3281 KASSERT(pm != NULL, ("[pmc,%d] null pmc", __LINE__)); 3282 3283 PMCDBG3(PMC,OPS,1, "stop pmc=%p mode=%d ri=%d", pm, 3284 PMC_TO_MODE(pm), PMC_TO_ROWINDEX(pm)); 3285 3286 pm->pm_state = PMC_STATE_STOPPED; 3287 3288 /* 3289 * If the PMC is a virtual mode one, changing the state to 3290 * non-RUNNING is enough to ensure that the PMC never gets 3291 * scheduled. 3292 * 3293 * If this PMC is current running on a CPU, then it will 3294 * handled correctly at the time its target process is context 3295 * switched out. 3296 */ 3297 3298 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) 3299 return 0; 3300 3301 /* 3302 * A system-mode PMC. Move to the CPU associated with 3303 * this PMC, and stop the hardware. We update the 3304 * 'initial count' so that a subsequent PMCSTART will 3305 * resume counting from the current hardware count. 3306 */ 3307 3308 pmc_save_cpu_binding(&pb); 3309 3310 cpu = PMC_TO_CPU(pm); 3311 3312 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 3313 ("[pmc,%d] illegal cpu=%d", __LINE__, cpu)); 3314 3315 if (!pmc_cpu_is_active(cpu)) 3316 return ENXIO; 3317 3318 pmc_select_cpu(cpu); 3319 3320 ri = PMC_TO_ROWINDEX(pm); 3321 pcd = pmc_ri_to_classdep(md, ri, &adjri); 3322 3323 pm->pm_pcpu_state[cpu].pps_cpustate = 0; 3324 critical_enter(); 3325 if ((error = pcd->pcd_stop_pmc(cpu, adjri, pm)) == 0) 3326 error = pcd->pcd_read_pmc(cpu, adjri, pm, 3327 &pm->pm_sc.pm_initial); 3328 critical_exit(); 3329 3330 pmc_restore_cpu_binding(&pb); 3331 3332 po = pm->pm_owner; 3333 3334 /* remove this owner from the global list of SS PMC owners */ 3335 if (PMC_TO_MODE(pm) == PMC_MODE_SS) { 3336 po->po_sscount--; 3337 if (po->po_sscount == 0) { 3338 atomic_subtract_rel_int(&pmc_ss_count, 1); 3339 CK_LIST_REMOVE(po, po_ssnext); 3340 epoch_wait_preempt(global_epoch_preempt); 3341 PMCDBG1(PMC,OPS,2,"po=%p removed from global list", po); 3342 } 3343 } 3344 3345 return (error); 3346 } 3347 3348 static struct pmc_classdep * 3349 pmc_class_to_classdep(enum pmc_class class) 3350 { 3351 int n; 3352 3353 for (n = 0; n < md->pmd_nclass; n++) 3354 if (md->pmd_classdep[n].pcd_class == class) 3355 return (&md->pmd_classdep[n]); 3356 return (NULL); 3357 } 3358 3359 #if defined(HWPMC_DEBUG) && defined(KTR) 3360 static const char *pmc_op_to_name[] = { 3361 #undef __PMC_OP 3362 #define __PMC_OP(N, D) #N , 3363 __PMC_OPS() 3364 NULL 3365 }; 3366 #endif 3367 3368 /* 3369 * The syscall interface 3370 */ 3371 3372 #define PMC_GET_SX_XLOCK(...) do { \ 3373 sx_xlock(&pmc_sx); \ 3374 if (pmc_hook == NULL) { \ 3375 sx_xunlock(&pmc_sx); \ 3376 return __VA_ARGS__; \ 3377 } \ 3378 } while (0) 3379 3380 #define PMC_DOWNGRADE_SX() do { \ 3381 sx_downgrade(&pmc_sx); \ 3382 is_sx_downgraded = 1; \ 3383 } while (0) 3384 3385 static int 3386 pmc_syscall_handler(struct thread *td, void *syscall_args) 3387 { 3388 int error, is_sx_downgraded, op; 3389 struct pmc_syscall_args *c; 3390 void *pmclog_proc_handle; 3391 void *arg; 3392 3393 c = (struct pmc_syscall_args *)syscall_args; 3394 op = c->pmop_code; 3395 arg = c->pmop_data; 3396 /* PMC isn't set up yet */ 3397 if (pmc_hook == NULL) 3398 return (EINVAL); 3399 if (op == PMC_OP_CONFIGURELOG) { 3400 /* 3401 * We cannot create the logging process inside 3402 * pmclog_configure_log() because there is a LOR 3403 * between pmc_sx and process structure locks. 3404 * Instead, pre-create the process and ignite the loop 3405 * if everything is fine, otherwise direct the process 3406 * to exit. 3407 */ 3408 error = pmclog_proc_create(td, &pmclog_proc_handle); 3409 if (error != 0) 3410 goto done_syscall; 3411 } 3412 3413 PMC_GET_SX_XLOCK(ENOSYS); 3414 is_sx_downgraded = 0; 3415 PMCDBG3(MOD,PMS,1, "syscall op=%d \"%s\" arg=%p", op, 3416 pmc_op_to_name[op], arg); 3417 3418 error = 0; 3419 counter_u64_add(pmc_stats.pm_syscalls, 1); 3420 3421 switch (op) { 3422 3423 3424 /* 3425 * Configure a log file. 3426 * 3427 * XXX This OP will be reworked. 3428 */ 3429 3430 case PMC_OP_CONFIGURELOG: 3431 { 3432 struct proc *p; 3433 struct pmc *pm; 3434 struct pmc_owner *po; 3435 struct pmc_op_configurelog cl; 3436 3437 if ((error = copyin(arg, &cl, sizeof(cl))) != 0) { 3438 pmclog_proc_ignite(pmclog_proc_handle, NULL); 3439 break; 3440 } 3441 3442 /* No flags currently implemented */ 3443 if (cl.pm_flags != 0) { 3444 error = EINVAL; 3445 break; 3446 } 3447 3448 /* mark this process as owning a log file */ 3449 p = td->td_proc; 3450 if ((po = pmc_find_owner_descriptor(p)) == NULL) 3451 if ((po = pmc_allocate_owner_descriptor(p)) == NULL) { 3452 pmclog_proc_ignite(pmclog_proc_handle, NULL); 3453 error = ENOMEM; 3454 break; 3455 } 3456 3457 /* 3458 * If a valid fd was passed in, try to configure that, 3459 * otherwise if 'fd' was less than zero and there was 3460 * a log file configured, flush its buffers and 3461 * de-configure it. 3462 */ 3463 if (cl.pm_logfd >= 0) { 3464 error = pmclog_configure_log(md, po, cl.pm_logfd); 3465 pmclog_proc_ignite(pmclog_proc_handle, error == 0 ? 3466 po : NULL); 3467 } else if (po->po_flags & PMC_PO_OWNS_LOGFILE) { 3468 pmclog_proc_ignite(pmclog_proc_handle, NULL); 3469 error = pmclog_close(po); 3470 if (error == 0) { 3471 LIST_FOREACH(pm, &po->po_pmcs, pm_next) 3472 if (pm->pm_flags & PMC_F_NEEDS_LOGFILE && 3473 pm->pm_state == PMC_STATE_RUNNING) 3474 pmc_stop(pm); 3475 error = pmclog_deconfigure_log(po); 3476 } 3477 } else { 3478 pmclog_proc_ignite(pmclog_proc_handle, NULL); 3479 error = EINVAL; 3480 } 3481 } 3482 break; 3483 3484 /* 3485 * Flush a log file. 3486 */ 3487 3488 case PMC_OP_FLUSHLOG: 3489 { 3490 struct pmc_owner *po; 3491 3492 sx_assert(&pmc_sx, SX_XLOCKED); 3493 3494 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 3495 error = EINVAL; 3496 break; 3497 } 3498 3499 error = pmclog_flush(po, 0); 3500 } 3501 break; 3502 3503 /* 3504 * Close a log file. 3505 */ 3506 3507 case PMC_OP_CLOSELOG: 3508 { 3509 struct pmc_owner *po; 3510 3511 sx_assert(&pmc_sx, SX_XLOCKED); 3512 3513 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 3514 error = EINVAL; 3515 break; 3516 } 3517 3518 error = pmclog_close(po); 3519 } 3520 break; 3521 3522 /* 3523 * Retrieve hardware configuration. 3524 */ 3525 3526 case PMC_OP_GETCPUINFO: /* CPU information */ 3527 { 3528 struct pmc_op_getcpuinfo gci; 3529 struct pmc_classinfo *pci; 3530 struct pmc_classdep *pcd; 3531 int cl; 3532 3533 memset(&gci, 0, sizeof(gci)); 3534 gci.pm_cputype = md->pmd_cputype; 3535 gci.pm_ncpu = pmc_cpu_max(); 3536 gci.pm_npmc = md->pmd_npmc; 3537 gci.pm_nclass = md->pmd_nclass; 3538 pci = gci.pm_classes; 3539 pcd = md->pmd_classdep; 3540 for (cl = 0; cl < md->pmd_nclass; cl++, pci++, pcd++) { 3541 pci->pm_caps = pcd->pcd_caps; 3542 pci->pm_class = pcd->pcd_class; 3543 pci->pm_width = pcd->pcd_width; 3544 pci->pm_num = pcd->pcd_num; 3545 } 3546 error = copyout(&gci, arg, sizeof(gci)); 3547 } 3548 break; 3549 3550 /* 3551 * Retrieve soft events list. 3552 */ 3553 case PMC_OP_GETDYNEVENTINFO: 3554 { 3555 enum pmc_class cl; 3556 enum pmc_event ev; 3557 struct pmc_op_getdyneventinfo *gei; 3558 struct pmc_dyn_event_descr dev; 3559 struct pmc_soft *ps; 3560 uint32_t nevent; 3561 3562 sx_assert(&pmc_sx, SX_LOCKED); 3563 3564 gei = (struct pmc_op_getdyneventinfo *) arg; 3565 3566 if ((error = copyin(&gei->pm_class, &cl, sizeof(cl))) != 0) 3567 break; 3568 3569 /* Only SOFT class is dynamic. */ 3570 if (cl != PMC_CLASS_SOFT) { 3571 error = EINVAL; 3572 break; 3573 } 3574 3575 nevent = 0; 3576 for (ev = PMC_EV_SOFT_FIRST; (int)ev <= PMC_EV_SOFT_LAST; ev++) { 3577 ps = pmc_soft_ev_acquire(ev); 3578 if (ps == NULL) 3579 continue; 3580 bcopy(&ps->ps_ev, &dev, sizeof(dev)); 3581 pmc_soft_ev_release(ps); 3582 3583 error = copyout(&dev, 3584 &gei->pm_events[nevent], 3585 sizeof(struct pmc_dyn_event_descr)); 3586 if (error != 0) 3587 break; 3588 nevent++; 3589 } 3590 if (error != 0) 3591 break; 3592 3593 error = copyout(&nevent, &gei->pm_nevent, 3594 sizeof(nevent)); 3595 } 3596 break; 3597 3598 /* 3599 * Get module statistics 3600 */ 3601 3602 case PMC_OP_GETDRIVERSTATS: 3603 { 3604 struct pmc_op_getdriverstats gms; 3605 #define CFETCH(a, b, field) a.field = counter_u64_fetch(b.field) 3606 CFETCH(gms, pmc_stats, pm_intr_ignored); 3607 CFETCH(gms, pmc_stats, pm_intr_processed); 3608 CFETCH(gms, pmc_stats, pm_intr_bufferfull); 3609 CFETCH(gms, pmc_stats, pm_syscalls); 3610 CFETCH(gms, pmc_stats, pm_syscall_errors); 3611 CFETCH(gms, pmc_stats, pm_buffer_requests); 3612 CFETCH(gms, pmc_stats, pm_buffer_requests_failed); 3613 CFETCH(gms, pmc_stats, pm_log_sweeps); 3614 #undef CFETCH 3615 error = copyout(&gms, arg, sizeof(gms)); 3616 } 3617 break; 3618 3619 3620 /* 3621 * Retrieve module version number 3622 */ 3623 3624 case PMC_OP_GETMODULEVERSION: 3625 { 3626 uint32_t cv, modv; 3627 3628 /* retrieve the client's idea of the ABI version */ 3629 if ((error = copyin(arg, &cv, sizeof(uint32_t))) != 0) 3630 break; 3631 /* don't service clients newer than our driver */ 3632 modv = PMC_VERSION; 3633 if ((cv & 0xFFFF0000) > (modv & 0xFFFF0000)) { 3634 error = EPROGMISMATCH; 3635 break; 3636 } 3637 error = copyout(&modv, arg, sizeof(int)); 3638 } 3639 break; 3640 3641 3642 /* 3643 * Retrieve the state of all the PMCs on a given 3644 * CPU. 3645 */ 3646 3647 case PMC_OP_GETPMCINFO: 3648 { 3649 int ari; 3650 struct pmc *pm; 3651 size_t pmcinfo_size; 3652 uint32_t cpu, n, npmc; 3653 struct pmc_owner *po; 3654 struct pmc_binding pb; 3655 struct pmc_classdep *pcd; 3656 struct pmc_info *p, *pmcinfo; 3657 struct pmc_op_getpmcinfo *gpi; 3658 3659 PMC_DOWNGRADE_SX(); 3660 3661 gpi = (struct pmc_op_getpmcinfo *) arg; 3662 3663 if ((error = copyin(&gpi->pm_cpu, &cpu, sizeof(cpu))) != 0) 3664 break; 3665 3666 if (cpu >= pmc_cpu_max()) { 3667 error = EINVAL; 3668 break; 3669 } 3670 3671 if (!pmc_cpu_is_active(cpu)) { 3672 error = ENXIO; 3673 break; 3674 } 3675 3676 /* switch to CPU 'cpu' */ 3677 pmc_save_cpu_binding(&pb); 3678 pmc_select_cpu(cpu); 3679 3680 npmc = md->pmd_npmc; 3681 3682 pmcinfo_size = npmc * sizeof(struct pmc_info); 3683 pmcinfo = malloc(pmcinfo_size, M_PMC, M_WAITOK | M_ZERO); 3684 3685 p = pmcinfo; 3686 3687 for (n = 0; n < md->pmd_npmc; n++, p++) { 3688 3689 pcd = pmc_ri_to_classdep(md, n, &ari); 3690 3691 KASSERT(pcd != NULL, 3692 ("[pmc,%d] null pcd ri=%d", __LINE__, n)); 3693 3694 if ((error = pcd->pcd_describe(cpu, ari, p, &pm)) != 0) 3695 break; 3696 3697 if (PMC_ROW_DISP_IS_STANDALONE(n)) 3698 p->pm_rowdisp = PMC_DISP_STANDALONE; 3699 else if (PMC_ROW_DISP_IS_THREAD(n)) 3700 p->pm_rowdisp = PMC_DISP_THREAD; 3701 else 3702 p->pm_rowdisp = PMC_DISP_FREE; 3703 3704 p->pm_ownerpid = -1; 3705 3706 if (pm == NULL) /* no PMC associated */ 3707 continue; 3708 3709 po = pm->pm_owner; 3710 3711 KASSERT(po->po_owner != NULL, 3712 ("[pmc,%d] pmc_owner had a null proc pointer", 3713 __LINE__)); 3714 3715 p->pm_ownerpid = po->po_owner->p_pid; 3716 p->pm_mode = PMC_TO_MODE(pm); 3717 p->pm_event = pm->pm_event; 3718 p->pm_flags = pm->pm_flags; 3719 3720 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 3721 p->pm_reloadcount = 3722 pm->pm_sc.pm_reloadcount; 3723 } 3724 3725 pmc_restore_cpu_binding(&pb); 3726 3727 /* now copy out the PMC info collected */ 3728 if (error == 0) 3729 error = copyout(pmcinfo, &gpi->pm_pmcs, pmcinfo_size); 3730 3731 free(pmcinfo, M_PMC); 3732 } 3733 break; 3734 3735 3736 /* 3737 * Set the administrative state of a PMC. I.e. whether 3738 * the PMC is to be used or not. 3739 */ 3740 3741 case PMC_OP_PMCADMIN: 3742 { 3743 int cpu, ri; 3744 enum pmc_state request; 3745 struct pmc_cpu *pc; 3746 struct pmc_hw *phw; 3747 struct pmc_op_pmcadmin pma; 3748 struct pmc_binding pb; 3749 3750 sx_assert(&pmc_sx, SX_XLOCKED); 3751 3752 KASSERT(td == curthread, 3753 ("[pmc,%d] td != curthread", __LINE__)); 3754 3755 error = priv_check(td, PRIV_PMC_MANAGE); 3756 if (error) 3757 break; 3758 3759 if ((error = copyin(arg, &pma, sizeof(pma))) != 0) 3760 break; 3761 3762 cpu = pma.pm_cpu; 3763 3764 if (cpu < 0 || cpu >= (int) pmc_cpu_max()) { 3765 error = EINVAL; 3766 break; 3767 } 3768 3769 if (!pmc_cpu_is_active(cpu)) { 3770 error = ENXIO; 3771 break; 3772 } 3773 3774 request = pma.pm_state; 3775 3776 if (request != PMC_STATE_DISABLED && 3777 request != PMC_STATE_FREE) { 3778 error = EINVAL; 3779 break; 3780 } 3781 3782 ri = pma.pm_pmc; /* pmc id == row index */ 3783 if (ri < 0 || ri >= (int) md->pmd_npmc) { 3784 error = EINVAL; 3785 break; 3786 } 3787 3788 /* 3789 * We can't disable a PMC with a row-index allocated 3790 * for process virtual PMCs. 3791 */ 3792 3793 if (PMC_ROW_DISP_IS_THREAD(ri) && 3794 request == PMC_STATE_DISABLED) { 3795 error = EBUSY; 3796 break; 3797 } 3798 3799 /* 3800 * otherwise, this PMC on this CPU is either free or 3801 * in system-wide mode. 3802 */ 3803 3804 pmc_save_cpu_binding(&pb); 3805 pmc_select_cpu(cpu); 3806 3807 pc = pmc_pcpu[cpu]; 3808 phw = pc->pc_hwpmcs[ri]; 3809 3810 /* 3811 * XXX do we need some kind of 'forced' disable? 3812 */ 3813 3814 if (phw->phw_pmc == NULL) { 3815 if (request == PMC_STATE_DISABLED && 3816 (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED)) { 3817 phw->phw_state &= ~PMC_PHW_FLAG_IS_ENABLED; 3818 PMC_MARK_ROW_STANDALONE(ri); 3819 } else if (request == PMC_STATE_FREE && 3820 (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0) { 3821 phw->phw_state |= PMC_PHW_FLAG_IS_ENABLED; 3822 PMC_UNMARK_ROW_STANDALONE(ri); 3823 } 3824 /* other cases are a no-op */ 3825 } else 3826 error = EBUSY; 3827 3828 pmc_restore_cpu_binding(&pb); 3829 } 3830 break; 3831 3832 3833 /* 3834 * Allocate a PMC. 3835 */ 3836 3837 case PMC_OP_PMCALLOCATE: 3838 { 3839 int adjri, n; 3840 u_int cpu; 3841 uint32_t caps; 3842 struct pmc *pmc; 3843 enum pmc_mode mode; 3844 struct pmc_hw *phw; 3845 struct pmc_binding pb; 3846 struct pmc_classdep *pcd; 3847 struct pmc_op_pmcallocate pa; 3848 3849 if ((error = copyin(arg, &pa, sizeof(pa))) != 0) 3850 break; 3851 3852 caps = pa.pm_caps; 3853 mode = pa.pm_mode; 3854 cpu = pa.pm_cpu; 3855 3856 if ((mode != PMC_MODE_SS && mode != PMC_MODE_SC && 3857 mode != PMC_MODE_TS && mode != PMC_MODE_TC) || 3858 (cpu != (u_int) PMC_CPU_ANY && cpu >= pmc_cpu_max())) { 3859 error = EINVAL; 3860 break; 3861 } 3862 3863 /* 3864 * Virtual PMCs should only ask for a default CPU. 3865 * System mode PMCs need to specify a non-default CPU. 3866 */ 3867 3868 if ((PMC_IS_VIRTUAL_MODE(mode) && cpu != (u_int) PMC_CPU_ANY) || 3869 (PMC_IS_SYSTEM_MODE(mode) && cpu == (u_int) PMC_CPU_ANY)) { 3870 error = EINVAL; 3871 break; 3872 } 3873 3874 /* 3875 * Check that an inactive CPU is not being asked for. 3876 */ 3877 3878 if (PMC_IS_SYSTEM_MODE(mode) && !pmc_cpu_is_active(cpu)) { 3879 error = ENXIO; 3880 break; 3881 } 3882 3883 /* 3884 * Refuse an allocation for a system-wide PMC if this 3885 * process has been jailed, or if this process lacks 3886 * super-user credentials and the sysctl tunable 3887 * 'security.bsd.unprivileged_syspmcs' is zero. 3888 */ 3889 3890 if (PMC_IS_SYSTEM_MODE(mode)) { 3891 if (jailed(curthread->td_ucred)) { 3892 error = EPERM; 3893 break; 3894 } 3895 if (!pmc_unprivileged_syspmcs) { 3896 error = priv_check(curthread, 3897 PRIV_PMC_SYSTEM); 3898 if (error) 3899 break; 3900 } 3901 } 3902 3903 /* 3904 * Look for valid values for 'pm_flags' 3905 */ 3906 3907 if ((pa.pm_flags & ~(PMC_F_DESCENDANTS | PMC_F_LOG_PROCCSW | 3908 PMC_F_LOG_PROCEXIT | PMC_F_CALLCHAIN | 3909 PMC_F_USERCALLCHAIN)) != 0) { 3910 error = EINVAL; 3911 break; 3912 } 3913 3914 /* PMC_F_USERCALLCHAIN is only valid with PMC_F_CALLCHAIN */ 3915 if ((pa.pm_flags & (PMC_F_CALLCHAIN | PMC_F_USERCALLCHAIN)) == 3916 PMC_F_USERCALLCHAIN) { 3917 error = EINVAL; 3918 break; 3919 } 3920 3921 /* PMC_F_USERCALLCHAIN is only valid for sampling mode */ 3922 if (pa.pm_flags & PMC_F_USERCALLCHAIN && 3923 mode != PMC_MODE_TS && mode != PMC_MODE_SS) { 3924 error = EINVAL; 3925 break; 3926 } 3927 3928 /* process logging options are not allowed for system PMCs */ 3929 if (PMC_IS_SYSTEM_MODE(mode) && (pa.pm_flags & 3930 (PMC_F_LOG_PROCCSW | PMC_F_LOG_PROCEXIT))) { 3931 error = EINVAL; 3932 break; 3933 } 3934 3935 /* 3936 * All sampling mode PMCs need to be able to interrupt the 3937 * CPU. 3938 */ 3939 if (PMC_IS_SAMPLING_MODE(mode)) 3940 caps |= PMC_CAP_INTERRUPT; 3941 3942 /* A valid class specifier should have been passed in. */ 3943 pcd = pmc_class_to_classdep(pa.pm_class); 3944 if (pcd == NULL) { 3945 error = EINVAL; 3946 break; 3947 } 3948 3949 /* The requested PMC capabilities should be feasible. */ 3950 if ((pcd->pcd_caps & caps) != caps) { 3951 error = EOPNOTSUPP; 3952 break; 3953 } 3954 3955 PMCDBG4(PMC,ALL,2, "event=%d caps=0x%x mode=%d cpu=%d", 3956 pa.pm_ev, caps, mode, cpu); 3957 3958 pmc = pmc_allocate_pmc_descriptor(); 3959 pmc->pm_id = PMC_ID_MAKE_ID(cpu,pa.pm_mode,pa.pm_class, 3960 PMC_ID_INVALID); 3961 pmc->pm_event = pa.pm_ev; 3962 pmc->pm_state = PMC_STATE_FREE; 3963 pmc->pm_caps = caps; 3964 pmc->pm_flags = pa.pm_flags; 3965 3966 /* XXX set lower bound on sampling for process counters */ 3967 if (PMC_IS_SAMPLING_MODE(mode)) { 3968 /* 3969 * Don't permit requested sample rate to be 3970 * less than pmc_mincount. 3971 */ 3972 if (pa.pm_count < MAX(1, pmc_mincount)) 3973 log(LOG_WARNING, "pmcallocate: passed sample " 3974 "rate %ju - setting to %u\n", 3975 (uintmax_t)pa.pm_count, 3976 MAX(1, pmc_mincount)); 3977 pmc->pm_sc.pm_reloadcount = MAX(MAX(1, pmc_mincount), 3978 pa.pm_count); 3979 } else 3980 pmc->pm_sc.pm_initial = pa.pm_count; 3981 3982 /* switch thread to CPU 'cpu' */ 3983 pmc_save_cpu_binding(&pb); 3984 3985 #define PMC_IS_SHAREABLE_PMC(cpu, n) \ 3986 (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_state & \ 3987 PMC_PHW_FLAG_IS_SHAREABLE) 3988 #define PMC_IS_UNALLOCATED(cpu, n) \ 3989 (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_pmc == NULL) 3990 3991 if (PMC_IS_SYSTEM_MODE(mode)) { 3992 pmc_select_cpu(cpu); 3993 for (n = pcd->pcd_ri; n < (int) md->pmd_npmc; n++) { 3994 pcd = pmc_ri_to_classdep(md, n, &adjri); 3995 if (pmc_can_allocate_row(n, mode) == 0 && 3996 pmc_can_allocate_rowindex( 3997 curthread->td_proc, n, cpu) == 0 && 3998 (PMC_IS_UNALLOCATED(cpu, n) || 3999 PMC_IS_SHAREABLE_PMC(cpu, n)) && 4000 pcd->pcd_allocate_pmc(cpu, adjri, pmc, 4001 &pa) == 0) 4002 break; 4003 } 4004 } else { 4005 /* Process virtual mode */ 4006 for (n = pcd->pcd_ri; n < (int) md->pmd_npmc; n++) { 4007 pcd = pmc_ri_to_classdep(md, n, &adjri); 4008 if (pmc_can_allocate_row(n, mode) == 0 && 4009 pmc_can_allocate_rowindex( 4010 curthread->td_proc, n, 4011 PMC_CPU_ANY) == 0 && 4012 pcd->pcd_allocate_pmc(curthread->td_oncpu, 4013 adjri, pmc, &pa) == 0) 4014 break; 4015 } 4016 } 4017 4018 #undef PMC_IS_UNALLOCATED 4019 #undef PMC_IS_SHAREABLE_PMC 4020 4021 pmc_restore_cpu_binding(&pb); 4022 4023 if (n == (int) md->pmd_npmc) { 4024 pmc_destroy_pmc_descriptor(pmc); 4025 pmc = NULL; 4026 error = EINVAL; 4027 break; 4028 } 4029 4030 /* Fill in the correct value in the ID field */ 4031 pmc->pm_id = PMC_ID_MAKE_ID(cpu,mode,pa.pm_class,n); 4032 4033 PMCDBG5(PMC,ALL,2, "ev=%d class=%d mode=%d n=%d -> pmcid=%x", 4034 pmc->pm_event, pa.pm_class, mode, n, pmc->pm_id); 4035 4036 /* Process mode PMCs with logging enabled need log files */ 4037 if (pmc->pm_flags & (PMC_F_LOG_PROCEXIT | PMC_F_LOG_PROCCSW)) 4038 pmc->pm_flags |= PMC_F_NEEDS_LOGFILE; 4039 4040 /* All system mode sampling PMCs require a log file */ 4041 if (PMC_IS_SAMPLING_MODE(mode) && PMC_IS_SYSTEM_MODE(mode)) 4042 pmc->pm_flags |= PMC_F_NEEDS_LOGFILE; 4043 4044 /* 4045 * Configure global pmc's immediately 4046 */ 4047 4048 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pmc))) { 4049 4050 pmc_save_cpu_binding(&pb); 4051 pmc_select_cpu(cpu); 4052 4053 phw = pmc_pcpu[cpu]->pc_hwpmcs[n]; 4054 pcd = pmc_ri_to_classdep(md, n, &adjri); 4055 4056 if ((phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0 || 4057 (error = pcd->pcd_config_pmc(cpu, adjri, pmc)) != 0) { 4058 (void) pcd->pcd_release_pmc(cpu, adjri, pmc); 4059 pmc_destroy_pmc_descriptor(pmc); 4060 pmc = NULL; 4061 pmc_restore_cpu_binding(&pb); 4062 error = EPERM; 4063 break; 4064 } 4065 4066 pmc_restore_cpu_binding(&pb); 4067 } 4068 4069 pmc->pm_state = PMC_STATE_ALLOCATED; 4070 pmc->pm_class = pa.pm_class; 4071 4072 /* 4073 * mark row disposition 4074 */ 4075 4076 if (PMC_IS_SYSTEM_MODE(mode)) 4077 PMC_MARK_ROW_STANDALONE(n); 4078 else 4079 PMC_MARK_ROW_THREAD(n); 4080 4081 /* 4082 * Register this PMC with the current thread as its owner. 4083 */ 4084 4085 if ((error = 4086 pmc_register_owner(curthread->td_proc, pmc)) != 0) { 4087 pmc_release_pmc_descriptor(pmc); 4088 pmc_destroy_pmc_descriptor(pmc); 4089 pmc = NULL; 4090 break; 4091 } 4092 4093 4094 /* 4095 * Return the allocated index. 4096 */ 4097 4098 pa.pm_pmcid = pmc->pm_id; 4099 4100 error = copyout(&pa, arg, sizeof(pa)); 4101 } 4102 break; 4103 4104 4105 /* 4106 * Attach a PMC to a process. 4107 */ 4108 4109 case PMC_OP_PMCATTACH: 4110 { 4111 struct pmc *pm; 4112 struct proc *p; 4113 struct pmc_op_pmcattach a; 4114 4115 sx_assert(&pmc_sx, SX_XLOCKED); 4116 4117 if ((error = copyin(arg, &a, sizeof(a))) != 0) 4118 break; 4119 4120 if (a.pm_pid < 0) { 4121 error = EINVAL; 4122 break; 4123 } else if (a.pm_pid == 0) 4124 a.pm_pid = td->td_proc->p_pid; 4125 4126 if ((error = pmc_find_pmc(a.pm_pmc, &pm)) != 0) 4127 break; 4128 4129 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) { 4130 error = EINVAL; 4131 break; 4132 } 4133 4134 /* PMCs may be (re)attached only when allocated or stopped */ 4135 if (pm->pm_state == PMC_STATE_RUNNING) { 4136 error = EBUSY; 4137 break; 4138 } else if (pm->pm_state != PMC_STATE_ALLOCATED && 4139 pm->pm_state != PMC_STATE_STOPPED) { 4140 error = EINVAL; 4141 break; 4142 } 4143 4144 /* lookup pid */ 4145 if ((p = pfind(a.pm_pid)) == NULL) { 4146 error = ESRCH; 4147 break; 4148 } 4149 4150 /* 4151 * Ignore processes that are working on exiting. 4152 */ 4153 if (p->p_flag & P_WEXIT) { 4154 error = ESRCH; 4155 PROC_UNLOCK(p); /* pfind() returns a locked process */ 4156 break; 4157 } 4158 4159 /* 4160 * we are allowed to attach a PMC to a process if 4161 * we can debug it. 4162 */ 4163 error = p_candebug(curthread, p); 4164 4165 PROC_UNLOCK(p); 4166 4167 if (error == 0) 4168 error = pmc_attach_process(p, pm); 4169 } 4170 break; 4171 4172 4173 /* 4174 * Detach an attached PMC from a process. 4175 */ 4176 4177 case PMC_OP_PMCDETACH: 4178 { 4179 struct pmc *pm; 4180 struct proc *p; 4181 struct pmc_op_pmcattach a; 4182 4183 if ((error = copyin(arg, &a, sizeof(a))) != 0) 4184 break; 4185 4186 if (a.pm_pid < 0) { 4187 error = EINVAL; 4188 break; 4189 } else if (a.pm_pid == 0) 4190 a.pm_pid = td->td_proc->p_pid; 4191 4192 if ((error = pmc_find_pmc(a.pm_pmc, &pm)) != 0) 4193 break; 4194 4195 if ((p = pfind(a.pm_pid)) == NULL) { 4196 error = ESRCH; 4197 break; 4198 } 4199 4200 /* 4201 * Treat processes that are in the process of exiting 4202 * as if they were not present. 4203 */ 4204 4205 if (p->p_flag & P_WEXIT) 4206 error = ESRCH; 4207 4208 PROC_UNLOCK(p); /* pfind() returns a locked process */ 4209 4210 if (error == 0) 4211 error = pmc_detach_process(p, pm); 4212 } 4213 break; 4214 4215 4216 /* 4217 * Retrieve the MSR number associated with the counter 4218 * 'pmc_id'. This allows processes to directly use RDPMC 4219 * instructions to read their PMCs, without the overhead of a 4220 * system call. 4221 */ 4222 4223 case PMC_OP_PMCGETMSR: 4224 { 4225 int adjri, ri; 4226 struct pmc *pm; 4227 struct pmc_target *pt; 4228 struct pmc_op_getmsr gm; 4229 struct pmc_classdep *pcd; 4230 4231 PMC_DOWNGRADE_SX(); 4232 4233 if ((error = copyin(arg, &gm, sizeof(gm))) != 0) 4234 break; 4235 4236 if ((error = pmc_find_pmc(gm.pm_pmcid, &pm)) != 0) 4237 break; 4238 4239 /* 4240 * The allocated PMC has to be a process virtual PMC, 4241 * i.e., of type MODE_T[CS]. Global PMCs can only be 4242 * read using the PMCREAD operation since they may be 4243 * allocated on a different CPU than the one we could 4244 * be running on at the time of the RDPMC instruction. 4245 * 4246 * The GETMSR operation is not allowed for PMCs that 4247 * are inherited across processes. 4248 */ 4249 4250 if (!PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)) || 4251 (pm->pm_flags & PMC_F_DESCENDANTS)) { 4252 error = EINVAL; 4253 break; 4254 } 4255 4256 /* 4257 * It only makes sense to use a RDPMC (or its 4258 * equivalent instruction on non-x86 architectures) on 4259 * a process that has allocated and attached a PMC to 4260 * itself. Conversely the PMC is only allowed to have 4261 * one process attached to it -- its owner. 4262 */ 4263 4264 if ((pt = LIST_FIRST(&pm->pm_targets)) == NULL || 4265 LIST_NEXT(pt, pt_next) != NULL || 4266 pt->pt_process->pp_proc != pm->pm_owner->po_owner) { 4267 error = EINVAL; 4268 break; 4269 } 4270 4271 ri = PMC_TO_ROWINDEX(pm); 4272 pcd = pmc_ri_to_classdep(md, ri, &adjri); 4273 4274 /* PMC class has no 'GETMSR' support */ 4275 if (pcd->pcd_get_msr == NULL) { 4276 error = ENOSYS; 4277 break; 4278 } 4279 4280 if ((error = (*pcd->pcd_get_msr)(adjri, &gm.pm_msr)) < 0) 4281 break; 4282 4283 if ((error = copyout(&gm, arg, sizeof(gm))) < 0) 4284 break; 4285 4286 /* 4287 * Mark our process as using MSRs. Update machine 4288 * state using a forced context switch. 4289 */ 4290 4291 pt->pt_process->pp_flags |= PMC_PP_ENABLE_MSR_ACCESS; 4292 pmc_force_context_switch(); 4293 4294 } 4295 break; 4296 4297 /* 4298 * Release an allocated PMC 4299 */ 4300 4301 case PMC_OP_PMCRELEASE: 4302 { 4303 pmc_id_t pmcid; 4304 struct pmc *pm; 4305 struct pmc_owner *po; 4306 struct pmc_op_simple sp; 4307 4308 /* 4309 * Find PMC pointer for the named PMC. 4310 * 4311 * Use pmc_release_pmc_descriptor() to switch off the 4312 * PMC, remove all its target threads, and remove the 4313 * PMC from its owner's list. 4314 * 4315 * Remove the owner record if this is the last PMC 4316 * owned. 4317 * 4318 * Free up space. 4319 */ 4320 4321 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 4322 break; 4323 4324 pmcid = sp.pm_pmcid; 4325 4326 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 4327 break; 4328 4329 po = pm->pm_owner; 4330 pmc_release_pmc_descriptor(pm); 4331 pmc_maybe_remove_owner(po); 4332 pmc_destroy_pmc_descriptor(pm); 4333 } 4334 break; 4335 4336 4337 /* 4338 * Read and/or write a PMC. 4339 */ 4340 4341 case PMC_OP_PMCRW: 4342 { 4343 int adjri; 4344 struct pmc *pm; 4345 uint32_t cpu, ri; 4346 pmc_value_t oldvalue; 4347 struct pmc_binding pb; 4348 struct pmc_op_pmcrw prw; 4349 struct pmc_classdep *pcd; 4350 struct pmc_op_pmcrw *pprw; 4351 4352 PMC_DOWNGRADE_SX(); 4353 4354 if ((error = copyin(arg, &prw, sizeof(prw))) != 0) 4355 break; 4356 4357 PMCDBG2(PMC,OPS,1, "rw id=%d flags=0x%x", prw.pm_pmcid, 4358 prw.pm_flags); 4359 4360 /* must have at least one flag set */ 4361 if ((prw.pm_flags & (PMC_F_OLDVALUE|PMC_F_NEWVALUE)) == 0) { 4362 error = EINVAL; 4363 break; 4364 } 4365 4366 /* locate pmc descriptor */ 4367 if ((error = pmc_find_pmc(prw.pm_pmcid, &pm)) != 0) 4368 break; 4369 4370 /* Can't read a PMC that hasn't been started. */ 4371 if (pm->pm_state != PMC_STATE_ALLOCATED && 4372 pm->pm_state != PMC_STATE_STOPPED && 4373 pm->pm_state != PMC_STATE_RUNNING) { 4374 error = EINVAL; 4375 break; 4376 } 4377 4378 /* writing a new value is allowed only for 'STOPPED' pmcs */ 4379 if (pm->pm_state == PMC_STATE_RUNNING && 4380 (prw.pm_flags & PMC_F_NEWVALUE)) { 4381 error = EBUSY; 4382 break; 4383 } 4384 4385 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) { 4386 4387 /* 4388 * If this PMC is attached to its owner (i.e., 4389 * the process requesting this operation) and 4390 * is running, then attempt to get an 4391 * upto-date reading from hardware for a READ. 4392 * Writes are only allowed when the PMC is 4393 * stopped, so only update the saved value 4394 * field. 4395 * 4396 * If the PMC is not running, or is not 4397 * attached to its owner, read/write to the 4398 * savedvalue field. 4399 */ 4400 4401 ri = PMC_TO_ROWINDEX(pm); 4402 pcd = pmc_ri_to_classdep(md, ri, &adjri); 4403 4404 mtx_pool_lock_spin(pmc_mtxpool, pm); 4405 cpu = curthread->td_oncpu; 4406 4407 if (prw.pm_flags & PMC_F_OLDVALUE) { 4408 if ((pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) && 4409 (pm->pm_state == PMC_STATE_RUNNING)) 4410 error = (*pcd->pcd_read_pmc)(cpu, adjri, 4411 pm, &oldvalue); 4412 else 4413 oldvalue = pm->pm_gv.pm_savedvalue; 4414 } 4415 if (prw.pm_flags & PMC_F_NEWVALUE) 4416 pm->pm_gv.pm_savedvalue = prw.pm_value; 4417 4418 mtx_pool_unlock_spin(pmc_mtxpool, pm); 4419 4420 } else { /* System mode PMCs */ 4421 cpu = PMC_TO_CPU(pm); 4422 ri = PMC_TO_ROWINDEX(pm); 4423 pcd = pmc_ri_to_classdep(md, ri, &adjri); 4424 4425 if (!pmc_cpu_is_active(cpu)) { 4426 error = ENXIO; 4427 break; 4428 } 4429 4430 /* move this thread to CPU 'cpu' */ 4431 pmc_save_cpu_binding(&pb); 4432 pmc_select_cpu(cpu); 4433 4434 critical_enter(); 4435 /* save old value */ 4436 if (prw.pm_flags & PMC_F_OLDVALUE) { 4437 if ((error = (*pcd->pcd_read_pmc)(cpu, adjri, 4438 pm, &oldvalue))) 4439 goto error; 4440 } 4441 /* write out new value */ 4442 if (prw.pm_flags & PMC_F_NEWVALUE) 4443 error = (*pcd->pcd_write_pmc)(cpu, adjri, pm, 4444 prw.pm_value); 4445 error: 4446 critical_exit(); 4447 pmc_restore_cpu_binding(&pb); 4448 if (error) 4449 break; 4450 } 4451 4452 pprw = (struct pmc_op_pmcrw *) arg; 4453 4454 #ifdef HWPMC_DEBUG 4455 if (prw.pm_flags & PMC_F_NEWVALUE) 4456 PMCDBG3(PMC,OPS,2, "rw id=%d new %jx -> old %jx", 4457 ri, prw.pm_value, oldvalue); 4458 else if (prw.pm_flags & PMC_F_OLDVALUE) 4459 PMCDBG2(PMC,OPS,2, "rw id=%d -> old %jx", ri, oldvalue); 4460 #endif 4461 4462 /* return old value if requested */ 4463 if (prw.pm_flags & PMC_F_OLDVALUE) 4464 if ((error = copyout(&oldvalue, &pprw->pm_value, 4465 sizeof(prw.pm_value)))) 4466 break; 4467 4468 } 4469 break; 4470 4471 4472 /* 4473 * Set the sampling rate for a sampling mode PMC and the 4474 * initial count for a counting mode PMC. 4475 */ 4476 4477 case PMC_OP_PMCSETCOUNT: 4478 { 4479 struct pmc *pm; 4480 struct pmc_op_pmcsetcount sc; 4481 4482 PMC_DOWNGRADE_SX(); 4483 4484 if ((error = copyin(arg, &sc, sizeof(sc))) != 0) 4485 break; 4486 4487 if ((error = pmc_find_pmc(sc.pm_pmcid, &pm)) != 0) 4488 break; 4489 4490 if (pm->pm_state == PMC_STATE_RUNNING) { 4491 error = EBUSY; 4492 break; 4493 } 4494 4495 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) { 4496 /* 4497 * Don't permit requested sample rate to be 4498 * less than pmc_mincount. 4499 */ 4500 if (sc.pm_count < MAX(1, pmc_mincount)) 4501 log(LOG_WARNING, "pmcsetcount: passed sample " 4502 "rate %ju - setting to %u\n", 4503 (uintmax_t)sc.pm_count, 4504 MAX(1, pmc_mincount)); 4505 pm->pm_sc.pm_reloadcount = MAX(MAX(1, pmc_mincount), 4506 sc.pm_count); 4507 } else 4508 pm->pm_sc.pm_initial = sc.pm_count; 4509 } 4510 break; 4511 4512 4513 /* 4514 * Start a PMC. 4515 */ 4516 4517 case PMC_OP_PMCSTART: 4518 { 4519 pmc_id_t pmcid; 4520 struct pmc *pm; 4521 struct pmc_op_simple sp; 4522 4523 sx_assert(&pmc_sx, SX_XLOCKED); 4524 4525 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 4526 break; 4527 4528 pmcid = sp.pm_pmcid; 4529 4530 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 4531 break; 4532 4533 KASSERT(pmcid == pm->pm_id, 4534 ("[pmc,%d] pmcid %x != id %x", __LINE__, 4535 pm->pm_id, pmcid)); 4536 4537 if (pm->pm_state == PMC_STATE_RUNNING) /* already running */ 4538 break; 4539 else if (pm->pm_state != PMC_STATE_STOPPED && 4540 pm->pm_state != PMC_STATE_ALLOCATED) { 4541 error = EINVAL; 4542 break; 4543 } 4544 4545 error = pmc_start(pm); 4546 } 4547 break; 4548 4549 4550 /* 4551 * Stop a PMC. 4552 */ 4553 4554 case PMC_OP_PMCSTOP: 4555 { 4556 pmc_id_t pmcid; 4557 struct pmc *pm; 4558 struct pmc_op_simple sp; 4559 4560 PMC_DOWNGRADE_SX(); 4561 4562 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 4563 break; 4564 4565 pmcid = sp.pm_pmcid; 4566 4567 /* 4568 * Mark the PMC as inactive and invoke the MD stop 4569 * routines if needed. 4570 */ 4571 4572 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 4573 break; 4574 4575 KASSERT(pmcid == pm->pm_id, 4576 ("[pmc,%d] pmc id %x != pmcid %x", __LINE__, 4577 pm->pm_id, pmcid)); 4578 4579 if (pm->pm_state == PMC_STATE_STOPPED) /* already stopped */ 4580 break; 4581 else if (pm->pm_state != PMC_STATE_RUNNING) { 4582 error = EINVAL; 4583 break; 4584 } 4585 4586 error = pmc_stop(pm); 4587 } 4588 break; 4589 4590 4591 /* 4592 * Write a user supplied value to the log file. 4593 */ 4594 4595 case PMC_OP_WRITELOG: 4596 { 4597 struct pmc_op_writelog wl; 4598 struct pmc_owner *po; 4599 4600 PMC_DOWNGRADE_SX(); 4601 4602 if ((error = copyin(arg, &wl, sizeof(wl))) != 0) 4603 break; 4604 4605 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 4606 error = EINVAL; 4607 break; 4608 } 4609 4610 if ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) { 4611 error = EINVAL; 4612 break; 4613 } 4614 4615 error = pmclog_process_userlog(po, &wl); 4616 } 4617 break; 4618 4619 4620 default: 4621 error = EINVAL; 4622 break; 4623 } 4624 4625 if (is_sx_downgraded) 4626 sx_sunlock(&pmc_sx); 4627 else 4628 sx_xunlock(&pmc_sx); 4629 done_syscall: 4630 if (error) 4631 counter_u64_add(pmc_stats.pm_syscall_errors, 1); 4632 4633 return (error); 4634 } 4635 4636 /* 4637 * Helper functions 4638 */ 4639 4640 4641 /* 4642 * Mark the thread as needing callchain capture and post an AST. The 4643 * actual callchain capture will be done in a context where it is safe 4644 * to take page faults. 4645 */ 4646 4647 static void 4648 pmc_post_callchain_callback(void) 4649 { 4650 struct thread *td; 4651 4652 td = curthread; 4653 4654 /* 4655 * If there is multiple PMCs for the same interrupt ignore new post 4656 */ 4657 if (td->td_pflags & TDP_CALLCHAIN) 4658 return; 4659 4660 /* 4661 * Mark this thread as needing callchain capture. 4662 * `td->td_pflags' will be safe to touch because this thread 4663 * was in user space when it was interrupted. 4664 */ 4665 td->td_pflags |= TDP_CALLCHAIN; 4666 4667 /* 4668 * Don't let this thread migrate between CPUs until callchain 4669 * capture completes. 4670 */ 4671 sched_pin(); 4672 4673 return; 4674 } 4675 4676 /* 4677 * Find a free slot in the per-cpu array of samples and capture the 4678 * current callchain there. If a sample was successfully added, a bit 4679 * is set in mask 'pmc_cpumask' denoting that the DO_SAMPLES hook 4680 * needs to be invoked from the clock handler. 4681 * 4682 * This function is meant to be called from an NMI handler. It cannot 4683 * use any of the locking primitives supplied by the OS. 4684 */ 4685 4686 static int 4687 pmc_add_sample(ring_type_t ring, struct pmc *pm, struct trapframe *tf) 4688 { 4689 int error, cpu, callchaindepth, inuserspace; 4690 struct thread *td; 4691 struct pmc_sample *ps; 4692 struct pmc_samplebuffer *psb; 4693 4694 error = 0; 4695 4696 /* 4697 * Allocate space for a sample buffer. 4698 */ 4699 cpu = curcpu; 4700 psb = pmc_pcpu[cpu]->pc_sb[ring]; 4701 inuserspace = TRAPF_USERMODE(tf); 4702 ps = PMC_PROD_SAMPLE(psb); 4703 if (psb->ps_considx != psb->ps_prodidx && 4704 ps->ps_nsamples) { /* in use, reader hasn't caught up */ 4705 pm->pm_pcpu_state[cpu].pps_stalled = 1; 4706 counter_u64_add(pmc_stats.pm_intr_bufferfull, 1); 4707 PMCDBG6(SAM,INT,1,"(spc) cpu=%d pm=%p tf=%p um=%d wr=%d rd=%d", 4708 cpu, pm, (void *) tf, inuserspace, 4709 (int) (psb->ps_prodidx & pmc_sample_mask), 4710 (int) (psb->ps_considx & pmc_sample_mask)); 4711 callchaindepth = 1; 4712 error = ENOMEM; 4713 goto done; 4714 } 4715 4716 /* Fill in entry. */ 4717 PMCDBG6(SAM,INT,1,"cpu=%d pm=%p tf=%p um=%d wr=%d rd=%d", cpu, pm, 4718 (void *) tf, inuserspace, 4719 (int) (psb->ps_prodidx & pmc_sample_mask), 4720 (int) (psb->ps_considx & pmc_sample_mask)); 4721 4722 td = curthread; 4723 ps->ps_pmc = pm; 4724 ps->ps_td = td; 4725 ps->ps_pid = td->td_proc->p_pid; 4726 ps->ps_tid = td->td_tid; 4727 ps->ps_tsc = pmc_rdtsc(); 4728 ps->ps_ticks = ticks; 4729 ps->ps_cpu = cpu; 4730 ps->ps_flags = inuserspace ? PMC_CC_F_USERSPACE : 0; 4731 4732 callchaindepth = (pm->pm_flags & PMC_F_CALLCHAIN) ? 4733 pmc_callchaindepth : 1; 4734 4735 MPASS(ps->ps_pc != NULL); 4736 if (callchaindepth == 1) 4737 ps->ps_pc[0] = PMC_TRAPFRAME_TO_PC(tf); 4738 else { 4739 /* 4740 * Kernel stack traversals can be done immediately, 4741 * while we defer to an AST for user space traversals. 4742 */ 4743 if (!inuserspace) { 4744 callchaindepth = 4745 pmc_save_kernel_callchain(ps->ps_pc, 4746 callchaindepth, tf); 4747 } else { 4748 pmc_post_callchain_callback(); 4749 callchaindepth = PMC_USER_CALLCHAIN_PENDING; 4750 } 4751 } 4752 4753 ps->ps_nsamples = callchaindepth; /* mark entry as in use */ 4754 if (ring == PMC_UR) { 4755 ps->ps_nsamples_actual = callchaindepth; /* mark entry as in use */ 4756 ps->ps_nsamples = PMC_USER_CALLCHAIN_PENDING; 4757 } else 4758 ps->ps_nsamples = callchaindepth; /* mark entry as in use */ 4759 4760 KASSERT(counter_u64_fetch(pm->pm_runcount) >= 0, 4761 ("[pmc,%d] pm=%p runcount %ld", __LINE__, (void *) pm, 4762 (unsigned long)counter_u64_fetch(pm->pm_runcount))); 4763 4764 counter_u64_add(pm->pm_runcount, 1); /* hold onto PMC */ 4765 /* increment write pointer */ 4766 psb->ps_prodidx++; 4767 done: 4768 /* mark CPU as needing processing */ 4769 if (callchaindepth != PMC_USER_CALLCHAIN_PENDING) 4770 DPCPU_SET(pmc_sampled, 1); 4771 4772 return (error); 4773 } 4774 4775 /* 4776 * Interrupt processing. 4777 * 4778 * This function is meant to be called from an NMI handler. It cannot 4779 * use any of the locking primitives supplied by the OS. 4780 */ 4781 4782 int 4783 pmc_process_interrupt(int ring, struct pmc *pm, struct trapframe *tf) 4784 { 4785 struct thread *td; 4786 4787 td = curthread; 4788 if ((pm->pm_flags & PMC_F_USERCALLCHAIN) && 4789 (td->td_proc->p_flag & P_KPROC) == 0 && 4790 !TRAPF_USERMODE(tf)) { 4791 atomic_add_int(&td->td_pmcpend, 1); 4792 return (pmc_add_sample(PMC_UR, pm, tf)); 4793 } 4794 return (pmc_add_sample(ring, pm, tf)); 4795 } 4796 4797 /* 4798 * Capture a user call chain. This function will be called from ast() 4799 * before control returns to userland and before the process gets 4800 * rescheduled. 4801 */ 4802 4803 static void 4804 pmc_capture_user_callchain(int cpu, int ring, struct trapframe *tf) 4805 { 4806 struct pmc *pm; 4807 struct thread *td; 4808 struct pmc_sample *ps; 4809 struct pmc_samplebuffer *psb; 4810 uint64_t considx, prodidx; 4811 int nsamples, nrecords, pass, iter; 4812 #ifdef INVARIANTS 4813 int start_ticks = ticks; 4814 #endif 4815 psb = pmc_pcpu[cpu]->pc_sb[ring]; 4816 td = curthread; 4817 4818 KASSERT(td->td_pflags & TDP_CALLCHAIN, 4819 ("[pmc,%d] Retrieving callchain for thread that doesn't want it", 4820 __LINE__)); 4821 4822 nrecords = INT_MAX; 4823 pass = 0; 4824 restart: 4825 if (ring == PMC_UR) 4826 nrecords = atomic_readandclear_32(&td->td_pmcpend); 4827 4828 for (iter = 0, considx = psb->ps_considx, prodidx = psb->ps_prodidx; 4829 considx < prodidx && iter < pmc_nsamples; considx++, iter++) { 4830 ps = PMC_CONS_SAMPLE_OFF(psb, considx); 4831 4832 /* 4833 * Iterate through all deferred callchain requests. 4834 * Walk from the current read pointer to the current 4835 * write pointer. 4836 */ 4837 4838 #ifdef INVARIANTS 4839 if (ps->ps_nsamples == PMC_SAMPLE_FREE) { 4840 continue; 4841 } 4842 #endif 4843 if (ps->ps_td != td || 4844 ps->ps_nsamples != PMC_USER_CALLCHAIN_PENDING || 4845 ps->ps_pmc->pm_state != PMC_STATE_RUNNING) 4846 continue; 4847 4848 KASSERT(ps->ps_cpu == cpu, 4849 ("[pmc,%d] cpu mismatch ps_cpu=%d pcpu=%d", __LINE__, 4850 ps->ps_cpu, PCPU_GET(cpuid))); 4851 4852 pm = ps->ps_pmc; 4853 4854 KASSERT(pm->pm_flags & PMC_F_CALLCHAIN, 4855 ("[pmc,%d] Retrieving callchain for PMC that doesn't " 4856 "want it", __LINE__)); 4857 4858 KASSERT(counter_u64_fetch(pm->pm_runcount) > 0, 4859 ("[pmc,%d] runcount %ld", __LINE__, (unsigned long)counter_u64_fetch(pm->pm_runcount))); 4860 4861 if (ring == PMC_UR) { 4862 nsamples = ps->ps_nsamples_actual; 4863 counter_u64_add(pmc_stats.pm_merges, 1); 4864 } else 4865 nsamples = 0; 4866 4867 /* 4868 * Retrieve the callchain and mark the sample buffer 4869 * as 'processable' by the timer tick sweep code. 4870 */ 4871 4872 if (__predict_true(nsamples < pmc_callchaindepth - 1)) 4873 nsamples += pmc_save_user_callchain(ps->ps_pc + nsamples, 4874 pmc_callchaindepth - nsamples - 1, tf); 4875 4876 /* 4877 * We have to prevent hardclock from potentially overwriting 4878 * this sample between when we read the value and when we set 4879 * it 4880 */ 4881 spinlock_enter(); 4882 /* 4883 * Verify that the sample hasn't been dropped in the meantime 4884 */ 4885 if (ps->ps_nsamples == PMC_USER_CALLCHAIN_PENDING) { 4886 ps->ps_nsamples = nsamples; 4887 /* 4888 * If we couldn't get a sample, simply drop the reference 4889 */ 4890 if (nsamples == 0) 4891 counter_u64_add(pm->pm_runcount, -1); 4892 } 4893 spinlock_exit(); 4894 if (nrecords-- == 1) 4895 break; 4896 } 4897 if (__predict_false(ring == PMC_UR && td->td_pmcpend)) { 4898 if (pass == 0) { 4899 pass = 1; 4900 goto restart; 4901 } 4902 /* only collect samples for this part once */ 4903 td->td_pmcpend = 0; 4904 } 4905 4906 #ifdef INVARIANTS 4907 if ((ticks - start_ticks) > hz) 4908 log(LOG_ERR, "%s took %d ticks\n", __func__, (ticks - start_ticks)); 4909 #endif 4910 4911 /* mark CPU as needing processing */ 4912 DPCPU_SET(pmc_sampled, 1); 4913 } 4914 4915 /* 4916 * Process saved PC samples. 4917 */ 4918 4919 static void 4920 pmc_process_samples(int cpu, ring_type_t ring) 4921 { 4922 struct pmc *pm; 4923 int adjri, n; 4924 struct thread *td; 4925 struct pmc_owner *po; 4926 struct pmc_sample *ps; 4927 struct pmc_classdep *pcd; 4928 struct pmc_samplebuffer *psb; 4929 uint64_t delta __diagused; 4930 4931 KASSERT(PCPU_GET(cpuid) == cpu, 4932 ("[pmc,%d] not on the correct CPU pcpu=%d cpu=%d", __LINE__, 4933 PCPU_GET(cpuid), cpu)); 4934 4935 psb = pmc_pcpu[cpu]->pc_sb[ring]; 4936 delta = psb->ps_prodidx - psb->ps_considx; 4937 MPASS(delta <= pmc_nsamples); 4938 MPASS(psb->ps_considx <= psb->ps_prodidx); 4939 for (n = 0; psb->ps_considx < psb->ps_prodidx; psb->ps_considx++, n++) { 4940 ps = PMC_CONS_SAMPLE(psb); 4941 4942 if (__predict_false(ps->ps_nsamples == PMC_SAMPLE_FREE)) 4943 continue; 4944 pm = ps->ps_pmc; 4945 /* skip non-running samples */ 4946 if (pm->pm_state != PMC_STATE_RUNNING) 4947 goto entrydone; 4948 4949 KASSERT(counter_u64_fetch(pm->pm_runcount) > 0, 4950 ("[pmc,%d] pm=%p runcount %ld", __LINE__, (void *) pm, 4951 (unsigned long)counter_u64_fetch(pm->pm_runcount))); 4952 4953 po = pm->pm_owner; 4954 4955 KASSERT(PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)), 4956 ("[pmc,%d] pmc=%p non-sampling mode=%d", __LINE__, 4957 pm, PMC_TO_MODE(pm))); 4958 4959 4960 /* If there is a pending AST wait for completion */ 4961 if (ps->ps_nsamples == PMC_USER_CALLCHAIN_PENDING) { 4962 /* if we've been waiting more than 1 tick to 4963 * collect a callchain for this record then 4964 * drop it and move on. 4965 */ 4966 if (ticks - ps->ps_ticks > 1) { 4967 /* 4968 * track how often we hit this as it will 4969 * preferentially lose user samples 4970 * for long running system calls 4971 */ 4972 counter_u64_add(pmc_stats.pm_overwrites, 1); 4973 goto entrydone; 4974 } 4975 /* Need a rescan at a later time. */ 4976 DPCPU_SET(pmc_sampled, 1); 4977 break; 4978 } 4979 4980 PMCDBG6(SAM,OPS,1,"cpu=%d pm=%p n=%d fl=%x wr=%d rd=%d", cpu, 4981 pm, ps->ps_nsamples, ps->ps_flags, 4982 (int) (psb->ps_prodidx & pmc_sample_mask), 4983 (int) (psb->ps_considx & pmc_sample_mask)); 4984 4985 /* 4986 * If this is a process-mode PMC that is attached to 4987 * its owner, and if the PC is in user mode, update 4988 * profiling statistics like timer-based profiling 4989 * would have done. 4990 * 4991 * Otherwise, this is either a sampling-mode PMC that 4992 * is attached to a different process than its owner, 4993 * or a system-wide sampling PMC. Dispatch a log 4994 * entry to the PMC's owner process. 4995 */ 4996 if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) { 4997 if (ps->ps_flags & PMC_CC_F_USERSPACE) { 4998 td = FIRST_THREAD_IN_PROC(po->po_owner); 4999 addupc_intr(td, ps->ps_pc[0], 1); 5000 } 5001 } else 5002 pmclog_process_callchain(pm, ps); 5003 5004 entrydone: 5005 ps->ps_nsamples = 0; /* mark entry as free */ 5006 KASSERT(counter_u64_fetch(pm->pm_runcount) > 0, 5007 ("[pmc,%d] pm=%p runcount %ld", __LINE__, (void *) pm, 5008 (unsigned long)counter_u64_fetch(pm->pm_runcount))); 5009 5010 counter_u64_add(pm->pm_runcount, -1); 5011 } 5012 5013 counter_u64_add(pmc_stats.pm_log_sweeps, 1); 5014 5015 /* Do not re-enable stalled PMCs if we failed to process any samples */ 5016 if (n == 0) 5017 return; 5018 5019 /* 5020 * Restart any stalled sampling PMCs on this CPU. 5021 * 5022 * If the NMI handler sets the pm_stalled field of a PMC after 5023 * the check below, we'll end up processing the stalled PMC at 5024 * the next hardclock tick. 5025 */ 5026 for (n = 0; n < md->pmd_npmc; n++) { 5027 pcd = pmc_ri_to_classdep(md, n, &adjri); 5028 KASSERT(pcd != NULL, 5029 ("[pmc,%d] null pcd ri=%d", __LINE__, n)); 5030 (void) (*pcd->pcd_get_config)(cpu,adjri,&pm); 5031 5032 if (pm == NULL || /* !cfg'ed */ 5033 pm->pm_state != PMC_STATE_RUNNING || /* !active */ 5034 !PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)) || /* !sampling */ 5035 !pm->pm_pcpu_state[cpu].pps_cpustate || /* !desired */ 5036 !pm->pm_pcpu_state[cpu].pps_stalled) /* !stalled */ 5037 continue; 5038 5039 pm->pm_pcpu_state[cpu].pps_stalled = 0; 5040 (*pcd->pcd_start_pmc)(cpu, adjri, pm); 5041 } 5042 } 5043 5044 /* 5045 * Event handlers. 5046 */ 5047 5048 /* 5049 * Handle a process exit. 5050 * 5051 * Remove this process from all hash tables. If this process 5052 * owned any PMCs, turn off those PMCs and deallocate them, 5053 * removing any associations with target processes. 5054 * 5055 * This function will be called by the last 'thread' of a 5056 * process. 5057 * 5058 * XXX This eventhandler gets called early in the exit process. 5059 * Consider using a 'hook' invocation from thread_exit() or equivalent 5060 * spot. Another negative is that kse_exit doesn't seem to call 5061 * exit1() [??]. 5062 * 5063 */ 5064 5065 static void 5066 pmc_process_exit(void *arg __unused, struct proc *p) 5067 { 5068 struct pmc *pm; 5069 int adjri, cpu; 5070 unsigned int ri; 5071 int is_using_hwpmcs; 5072 struct pmc_owner *po; 5073 struct pmc_process *pp; 5074 struct pmc_classdep *pcd; 5075 pmc_value_t newvalue, tmp; 5076 5077 PROC_LOCK(p); 5078 is_using_hwpmcs = p->p_flag & P_HWPMC; 5079 PROC_UNLOCK(p); 5080 5081 /* 5082 * Log a sysexit event to all SS PMC owners. 5083 */ 5084 PMC_EPOCH_ENTER(); 5085 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 5086 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 5087 pmclog_process_sysexit(po, p->p_pid); 5088 PMC_EPOCH_EXIT(); 5089 5090 if (!is_using_hwpmcs) 5091 return; 5092 5093 PMC_GET_SX_XLOCK(); 5094 PMCDBG3(PRC,EXT,1,"process-exit proc=%p (%d, %s)", p, p->p_pid, 5095 p->p_comm); 5096 5097 /* 5098 * Since this code is invoked by the last thread in an exiting 5099 * process, we would have context switched IN at some prior 5100 * point. However, with PREEMPTION, kernel mode context 5101 * switches may happen any time, so we want to disable a 5102 * context switch OUT till we get any PMCs targeting this 5103 * process off the hardware. 5104 * 5105 * We also need to atomically remove this process' 5106 * entry from our target process hash table, using 5107 * PMC_FLAG_REMOVE. 5108 */ 5109 PMCDBG3(PRC,EXT,1, "process-exit proc=%p (%d, %s)", p, p->p_pid, 5110 p->p_comm); 5111 5112 critical_enter(); /* no preemption */ 5113 5114 cpu = curthread->td_oncpu; 5115 5116 if ((pp = pmc_find_process_descriptor(p, 5117 PMC_FLAG_REMOVE)) != NULL) { 5118 5119 PMCDBG2(PRC,EXT,2, 5120 "process-exit proc=%p pmc-process=%p", p, pp); 5121 5122 /* 5123 * The exiting process could the target of 5124 * some PMCs which will be running on 5125 * currently executing CPU. 5126 * 5127 * We need to turn these PMCs off like we 5128 * would do at context switch OUT time. 5129 */ 5130 for (ri = 0; ri < md->pmd_npmc; ri++) { 5131 5132 /* 5133 * Pick up the pmc pointer from hardware 5134 * state similar to the CSW_OUT code. 5135 */ 5136 pm = NULL; 5137 5138 pcd = pmc_ri_to_classdep(md, ri, &adjri); 5139 5140 (void) (*pcd->pcd_get_config)(cpu, adjri, &pm); 5141 5142 PMCDBG2(PRC,EXT,2, "ri=%d pm=%p", ri, pm); 5143 5144 if (pm == NULL || 5145 !PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) 5146 continue; 5147 5148 PMCDBG4(PRC,EXT,2, "ppmcs[%d]=%p pm=%p " 5149 "state=%d", ri, pp->pp_pmcs[ri].pp_pmc, 5150 pm, pm->pm_state); 5151 5152 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 5153 ("[pmc,%d] ri mismatch pmc(%d) ri(%d)", 5154 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 5155 5156 KASSERT(pm == pp->pp_pmcs[ri].pp_pmc, 5157 ("[pmc,%d] pm %p != pp_pmcs[%d] %p", 5158 __LINE__, pm, ri, pp->pp_pmcs[ri].pp_pmc)); 5159 5160 KASSERT(counter_u64_fetch(pm->pm_runcount) > 0, 5161 ("[pmc,%d] bad runcount ri %d rc %ld", 5162 __LINE__, ri, (unsigned long)counter_u64_fetch(pm->pm_runcount))); 5163 5164 /* 5165 * Change desired state, and then stop if not 5166 * stalled. This two-step dance should avoid 5167 * race conditions where an interrupt re-enables 5168 * the PMC after this code has already checked 5169 * the pm_stalled flag. 5170 */ 5171 if (pm->pm_pcpu_state[cpu].pps_cpustate) { 5172 pm->pm_pcpu_state[cpu].pps_cpustate = 0; 5173 if (!pm->pm_pcpu_state[cpu].pps_stalled) { 5174 (void) pcd->pcd_stop_pmc(cpu, adjri, pm); 5175 5176 if (PMC_TO_MODE(pm) == PMC_MODE_TC) { 5177 pcd->pcd_read_pmc(cpu, adjri, 5178 pm, &newvalue); 5179 tmp = newvalue - 5180 PMC_PCPU_SAVED(cpu,ri); 5181 5182 mtx_pool_lock_spin(pmc_mtxpool, 5183 pm); 5184 pm->pm_gv.pm_savedvalue += tmp; 5185 pp->pp_pmcs[ri].pp_pmcval += 5186 tmp; 5187 mtx_pool_unlock_spin( 5188 pmc_mtxpool, pm); 5189 } 5190 } 5191 } 5192 5193 KASSERT((int64_t) counter_u64_fetch(pm->pm_runcount) > 0, 5194 ("[pmc,%d] runcount is %d", __LINE__, ri)); 5195 5196 counter_u64_add(pm->pm_runcount, -1); 5197 5198 (void) pcd->pcd_config_pmc(cpu, adjri, NULL); 5199 } 5200 5201 /* 5202 * Inform the MD layer of this pseudo "context switch 5203 * out" 5204 */ 5205 (void) md->pmd_switch_out(pmc_pcpu[cpu], pp); 5206 5207 critical_exit(); /* ok to be pre-empted now */ 5208 5209 /* 5210 * Unlink this process from the PMCs that are 5211 * targeting it. This will send a signal to 5212 * all PMC owner's whose PMCs are orphaned. 5213 * 5214 * Log PMC value at exit time if requested. 5215 */ 5216 for (ri = 0; ri < md->pmd_npmc; ri++) 5217 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) { 5218 if (pm->pm_flags & PMC_F_NEEDS_LOGFILE && 5219 PMC_IS_COUNTING_MODE(PMC_TO_MODE(pm))) 5220 pmclog_process_procexit(pm, pp); 5221 pmc_unlink_target_process(pm, pp); 5222 } 5223 free(pp, M_PMC); 5224 5225 } else 5226 critical_exit(); /* pp == NULL */ 5227 5228 5229 /* 5230 * If the process owned PMCs, free them up and free up 5231 * memory. 5232 */ 5233 if ((po = pmc_find_owner_descriptor(p)) != NULL) { 5234 pmc_remove_owner(po); 5235 pmc_destroy_owner_descriptor(po); 5236 } 5237 5238 sx_xunlock(&pmc_sx); 5239 } 5240 5241 /* 5242 * Handle a process fork. 5243 * 5244 * If the parent process 'p1' is under HWPMC monitoring, then copy 5245 * over any attached PMCs that have 'do_descendants' semantics. 5246 */ 5247 5248 static void 5249 pmc_process_fork(void *arg __unused, struct proc *p1, struct proc *newproc, 5250 int flags) 5251 { 5252 int is_using_hwpmcs; 5253 unsigned int ri; 5254 uint32_t do_descendants; 5255 struct pmc *pm; 5256 struct pmc_owner *po; 5257 struct pmc_process *ppnew, *ppold; 5258 5259 (void) flags; /* unused parameter */ 5260 5261 PROC_LOCK(p1); 5262 is_using_hwpmcs = p1->p_flag & P_HWPMC; 5263 PROC_UNLOCK(p1); 5264 5265 /* 5266 * If there are system-wide sampling PMCs active, we need to 5267 * log all fork events to their owner's logs. 5268 */ 5269 PMC_EPOCH_ENTER(); 5270 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 5271 if (po->po_flags & PMC_PO_OWNS_LOGFILE) { 5272 pmclog_process_procfork(po, p1->p_pid, newproc->p_pid); 5273 pmclog_process_proccreate(po, newproc, 1); 5274 } 5275 PMC_EPOCH_EXIT(); 5276 5277 if (!is_using_hwpmcs) 5278 return; 5279 5280 PMC_GET_SX_XLOCK(); 5281 PMCDBG4(PMC,FRK,1, "process-fork proc=%p (%d, %s) -> %p", p1, 5282 p1->p_pid, p1->p_comm, newproc); 5283 5284 /* 5285 * If the parent process (curthread->td_proc) is a 5286 * target of any PMCs, look for PMCs that are to be 5287 * inherited, and link these into the new process 5288 * descriptor. 5289 */ 5290 if ((ppold = pmc_find_process_descriptor(curthread->td_proc, 5291 PMC_FLAG_NONE)) == NULL) 5292 goto done; /* nothing to do */ 5293 5294 do_descendants = 0; 5295 for (ri = 0; ri < md->pmd_npmc; ri++) 5296 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL) 5297 do_descendants |= pm->pm_flags & PMC_F_DESCENDANTS; 5298 if (do_descendants == 0) /* nothing to do */ 5299 goto done; 5300 5301 /* 5302 * Now mark the new process as being tracked by this driver. 5303 */ 5304 PROC_LOCK(newproc); 5305 newproc->p_flag |= P_HWPMC; 5306 PROC_UNLOCK(newproc); 5307 5308 /* allocate a descriptor for the new process */ 5309 if ((ppnew = pmc_find_process_descriptor(newproc, 5310 PMC_FLAG_ALLOCATE)) == NULL) 5311 goto done; 5312 5313 /* 5314 * Run through all PMCs that were targeting the old process 5315 * and which specified F_DESCENDANTS and attach them to the 5316 * new process. 5317 * 5318 * Log the fork event to all owners of PMCs attached to this 5319 * process, if not already logged. 5320 */ 5321 for (ri = 0; ri < md->pmd_npmc; ri++) 5322 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL && 5323 (pm->pm_flags & PMC_F_DESCENDANTS)) { 5324 pmc_link_target_process(pm, ppnew); 5325 po = pm->pm_owner; 5326 if (po->po_sscount == 0 && 5327 po->po_flags & PMC_PO_OWNS_LOGFILE) 5328 pmclog_process_procfork(po, p1->p_pid, 5329 newproc->p_pid); 5330 } 5331 5332 done: 5333 sx_xunlock(&pmc_sx); 5334 } 5335 5336 static void 5337 pmc_process_threadcreate(struct thread *td) 5338 { 5339 struct pmc_owner *po; 5340 5341 PMC_EPOCH_ENTER(); 5342 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 5343 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 5344 pmclog_process_threadcreate(po, td, 1); 5345 PMC_EPOCH_EXIT(); 5346 } 5347 5348 static void 5349 pmc_process_threadexit(struct thread *td) 5350 { 5351 struct pmc_owner *po; 5352 5353 PMC_EPOCH_ENTER(); 5354 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 5355 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 5356 pmclog_process_threadexit(po, td); 5357 PMC_EPOCH_EXIT(); 5358 } 5359 5360 static void 5361 pmc_process_proccreate(struct proc *p) 5362 { 5363 struct pmc_owner *po; 5364 5365 PMC_EPOCH_ENTER(); 5366 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 5367 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 5368 pmclog_process_proccreate(po, p, 1 /* sync */); 5369 PMC_EPOCH_EXIT(); 5370 } 5371 5372 static void 5373 pmc_process_allproc(struct pmc *pm) 5374 { 5375 struct pmc_owner *po; 5376 struct thread *td; 5377 struct proc *p; 5378 5379 po = pm->pm_owner; 5380 if ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) 5381 return; 5382 sx_slock(&allproc_lock); 5383 FOREACH_PROC_IN_SYSTEM(p) { 5384 pmclog_process_proccreate(po, p, 0 /* sync */); 5385 PROC_LOCK(p); 5386 FOREACH_THREAD_IN_PROC(p, td) 5387 pmclog_process_threadcreate(po, td, 0 /* sync */); 5388 PROC_UNLOCK(p); 5389 } 5390 sx_sunlock(&allproc_lock); 5391 pmclog_flush(po, 0); 5392 } 5393 5394 static void 5395 pmc_kld_load(void *arg __unused, linker_file_t lf) 5396 { 5397 struct pmc_owner *po; 5398 5399 /* 5400 * Notify owners of system sampling PMCs about KLD operations. 5401 */ 5402 PMC_EPOCH_ENTER(); 5403 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 5404 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 5405 pmclog_process_map_in(po, (pid_t) -1, 5406 (uintfptr_t) lf->address, lf->pathname); 5407 PMC_EPOCH_EXIT(); 5408 5409 /* 5410 * TODO: Notify owners of (all) process-sampling PMCs too. 5411 */ 5412 } 5413 5414 static void 5415 pmc_kld_unload(void *arg __unused, const char *filename __unused, 5416 caddr_t address, size_t size) 5417 { 5418 struct pmc_owner *po; 5419 5420 PMC_EPOCH_ENTER(); 5421 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 5422 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 5423 pmclog_process_map_out(po, (pid_t) -1, 5424 (uintfptr_t) address, (uintfptr_t) address + size); 5425 PMC_EPOCH_EXIT(); 5426 5427 /* 5428 * TODO: Notify owners of process-sampling PMCs. 5429 */ 5430 } 5431 5432 /* 5433 * initialization 5434 */ 5435 static const char * 5436 pmc_name_of_pmcclass(enum pmc_class class) 5437 { 5438 5439 switch (class) { 5440 #undef __PMC_CLASS 5441 #define __PMC_CLASS(S,V,D) \ 5442 case PMC_CLASS_##S: \ 5443 return #S; 5444 __PMC_CLASSES(); 5445 default: 5446 return ("<unknown>"); 5447 } 5448 } 5449 5450 /* 5451 * Base class initializer: allocate structure and set default classes. 5452 */ 5453 struct pmc_mdep * 5454 pmc_mdep_alloc(int nclasses) 5455 { 5456 struct pmc_mdep *md; 5457 int n; 5458 5459 /* SOFT + md classes */ 5460 n = 1 + nclasses; 5461 md = malloc(sizeof(struct pmc_mdep) + n * 5462 sizeof(struct pmc_classdep), M_PMC, M_WAITOK|M_ZERO); 5463 md->pmd_nclass = n; 5464 5465 /* Default methods */ 5466 md->pmd_switch_in = generic_switch_in; 5467 md->pmd_switch_out = generic_switch_out; 5468 5469 /* Add base class. */ 5470 pmc_soft_initialize(md); 5471 return md; 5472 } 5473 5474 void 5475 pmc_mdep_free(struct pmc_mdep *md) 5476 { 5477 pmc_soft_finalize(md); 5478 free(md, M_PMC); 5479 } 5480 5481 static int 5482 generic_switch_in(struct pmc_cpu *pc, struct pmc_process *pp) 5483 { 5484 (void) pc; (void) pp; 5485 5486 return (0); 5487 } 5488 5489 static int 5490 generic_switch_out(struct pmc_cpu *pc, struct pmc_process *pp) 5491 { 5492 (void) pc; (void) pp; 5493 5494 return (0); 5495 } 5496 5497 static struct pmc_mdep * 5498 pmc_generic_cpu_initialize(void) 5499 { 5500 struct pmc_mdep *md; 5501 5502 md = pmc_mdep_alloc(0); 5503 5504 md->pmd_cputype = PMC_CPU_GENERIC; 5505 5506 return (md); 5507 } 5508 5509 static void 5510 pmc_generic_cpu_finalize(struct pmc_mdep *md) 5511 { 5512 (void) md; 5513 } 5514 5515 5516 static int 5517 pmc_initialize(void) 5518 { 5519 int c, cpu, error, n, ri; 5520 unsigned int maxcpu, domain; 5521 struct pcpu *pc; 5522 struct pmc_binding pb; 5523 struct pmc_sample *ps; 5524 struct pmc_classdep *pcd; 5525 struct pmc_samplebuffer *sb; 5526 5527 md = NULL; 5528 error = 0; 5529 5530 pmc_stats.pm_intr_ignored = counter_u64_alloc(M_WAITOK); 5531 pmc_stats.pm_intr_processed = counter_u64_alloc(M_WAITOK); 5532 pmc_stats.pm_intr_bufferfull = counter_u64_alloc(M_WAITOK); 5533 pmc_stats.pm_syscalls = counter_u64_alloc(M_WAITOK); 5534 pmc_stats.pm_syscall_errors = counter_u64_alloc(M_WAITOK); 5535 pmc_stats.pm_buffer_requests = counter_u64_alloc(M_WAITOK); 5536 pmc_stats.pm_buffer_requests_failed = counter_u64_alloc(M_WAITOK); 5537 pmc_stats.pm_log_sweeps = counter_u64_alloc(M_WAITOK); 5538 pmc_stats.pm_merges = counter_u64_alloc(M_WAITOK); 5539 pmc_stats.pm_overwrites = counter_u64_alloc(M_WAITOK); 5540 5541 #ifdef HWPMC_DEBUG 5542 /* parse debug flags first */ 5543 if (TUNABLE_STR_FETCH(PMC_SYSCTL_NAME_PREFIX "debugflags", 5544 pmc_debugstr, sizeof(pmc_debugstr))) 5545 pmc_debugflags_parse(pmc_debugstr, 5546 pmc_debugstr+strlen(pmc_debugstr)); 5547 #endif 5548 5549 PMCDBG1(MOD,INI,0, "PMC Initialize (version %x)", PMC_VERSION); 5550 5551 /* check kernel version */ 5552 if (pmc_kernel_version != PMC_VERSION) { 5553 if (pmc_kernel_version == 0) 5554 printf("hwpmc: this kernel has not been compiled with " 5555 "'options HWPMC_HOOKS'.\n"); 5556 else 5557 printf("hwpmc: kernel version (0x%x) does not match " 5558 "module version (0x%x).\n", pmc_kernel_version, 5559 PMC_VERSION); 5560 return EPROGMISMATCH; 5561 } 5562 5563 /* 5564 * check sysctl parameters 5565 */ 5566 5567 if (pmc_hashsize <= 0) { 5568 (void) printf("hwpmc: tunable \"hashsize\"=%d must be " 5569 "greater than zero.\n", pmc_hashsize); 5570 pmc_hashsize = PMC_HASH_SIZE; 5571 } 5572 5573 if (pmc_nsamples <= 0 || pmc_nsamples > 65535) { 5574 (void) printf("hwpmc: tunable \"nsamples\"=%d out of " 5575 "range.\n", pmc_nsamples); 5576 pmc_nsamples = PMC_NSAMPLES; 5577 } 5578 pmc_sample_mask = pmc_nsamples-1; 5579 5580 if (pmc_callchaindepth <= 0 || 5581 pmc_callchaindepth > PMC_CALLCHAIN_DEPTH_MAX) { 5582 (void) printf("hwpmc: tunable \"callchaindepth\"=%d out of " 5583 "range - using %d.\n", pmc_callchaindepth, 5584 PMC_CALLCHAIN_DEPTH_MAX); 5585 pmc_callchaindepth = PMC_CALLCHAIN_DEPTH_MAX; 5586 } 5587 5588 md = pmc_md_initialize(); 5589 if (md == NULL) { 5590 /* Default to generic CPU. */ 5591 md = pmc_generic_cpu_initialize(); 5592 if (md == NULL) 5593 return (ENOSYS); 5594 } 5595 5596 /* 5597 * Refresh classes base ri. Optional classes may come in different 5598 * order. 5599 */ 5600 for (ri = c = 0; c < md->pmd_nclass; c++) { 5601 pcd = &md->pmd_classdep[c]; 5602 pcd->pcd_ri = ri; 5603 ri += pcd->pcd_num; 5604 } 5605 5606 KASSERT(md->pmd_nclass >= 1 && md->pmd_npmc >= 1, 5607 ("[pmc,%d] no classes or pmcs", __LINE__)); 5608 5609 /* Compute the map from row-indices to classdep pointers. */ 5610 pmc_rowindex_to_classdep = malloc(sizeof(struct pmc_classdep *) * 5611 md->pmd_npmc, M_PMC, M_WAITOK|M_ZERO); 5612 5613 for (n = 0; n < md->pmd_npmc; n++) 5614 pmc_rowindex_to_classdep[n] = NULL; 5615 for (ri = c = 0; c < md->pmd_nclass; c++) { 5616 pcd = &md->pmd_classdep[c]; 5617 for (n = 0; n < pcd->pcd_num; n++, ri++) 5618 pmc_rowindex_to_classdep[ri] = pcd; 5619 } 5620 5621 KASSERT(ri == md->pmd_npmc, 5622 ("[pmc,%d] npmc miscomputed: ri=%d, md->npmc=%d", __LINE__, 5623 ri, md->pmd_npmc)); 5624 5625 maxcpu = pmc_cpu_max(); 5626 5627 /* allocate space for the per-cpu array */ 5628 pmc_pcpu = malloc(maxcpu * sizeof(struct pmc_cpu *), M_PMC, 5629 M_WAITOK|M_ZERO); 5630 5631 /* per-cpu 'saved values' for managing process-mode PMCs */ 5632 pmc_pcpu_saved = malloc(sizeof(pmc_value_t) * maxcpu * md->pmd_npmc, 5633 M_PMC, M_WAITOK); 5634 5635 /* Perform CPU-dependent initialization. */ 5636 pmc_save_cpu_binding(&pb); 5637 error = 0; 5638 for (cpu = 0; error == 0 && cpu < maxcpu; cpu++) { 5639 if (!pmc_cpu_is_active(cpu)) 5640 continue; 5641 pmc_select_cpu(cpu); 5642 pmc_pcpu[cpu] = malloc(sizeof(struct pmc_cpu) + 5643 md->pmd_npmc * sizeof(struct pmc_hw *), M_PMC, 5644 M_WAITOK|M_ZERO); 5645 for (n = 0; error == 0 && n < md->pmd_nclass; n++) 5646 if (md->pmd_classdep[n].pcd_num > 0) 5647 error = md->pmd_classdep[n].pcd_pcpu_init(md, 5648 cpu); 5649 } 5650 pmc_restore_cpu_binding(&pb); 5651 5652 if (error) 5653 return (error); 5654 5655 /* allocate space for the sample array */ 5656 for (cpu = 0; cpu < maxcpu; cpu++) { 5657 if (!pmc_cpu_is_active(cpu)) 5658 continue; 5659 pc = pcpu_find(cpu); 5660 domain = pc->pc_domain; 5661 sb = malloc_domainset(sizeof(struct pmc_samplebuffer) + 5662 pmc_nsamples * sizeof(struct pmc_sample), M_PMC, 5663 DOMAINSET_PREF(domain), M_WAITOK | M_ZERO); 5664 5665 KASSERT(pmc_pcpu[cpu] != NULL, 5666 ("[pmc,%d] cpu=%d Null per-cpu data", __LINE__, cpu)); 5667 5668 sb->ps_callchains = malloc_domainset(pmc_callchaindepth * 5669 pmc_nsamples * sizeof(uintptr_t), M_PMC, 5670 DOMAINSET_PREF(domain), M_WAITOK | M_ZERO); 5671 5672 for (n = 0, ps = sb->ps_samples; n < pmc_nsamples; n++, ps++) 5673 ps->ps_pc = sb->ps_callchains + 5674 (n * pmc_callchaindepth); 5675 5676 pmc_pcpu[cpu]->pc_sb[PMC_HR] = sb; 5677 5678 sb = malloc_domainset(sizeof(struct pmc_samplebuffer) + 5679 pmc_nsamples * sizeof(struct pmc_sample), M_PMC, 5680 DOMAINSET_PREF(domain), M_WAITOK | M_ZERO); 5681 5682 sb->ps_callchains = malloc_domainset(pmc_callchaindepth * 5683 pmc_nsamples * sizeof(uintptr_t), M_PMC, 5684 DOMAINSET_PREF(domain), M_WAITOK | M_ZERO); 5685 for (n = 0, ps = sb->ps_samples; n < pmc_nsamples; n++, ps++) 5686 ps->ps_pc = sb->ps_callchains + 5687 (n * pmc_callchaindepth); 5688 5689 pmc_pcpu[cpu]->pc_sb[PMC_SR] = sb; 5690 5691 sb = malloc_domainset(sizeof(struct pmc_samplebuffer) + 5692 pmc_nsamples * sizeof(struct pmc_sample), M_PMC, 5693 DOMAINSET_PREF(domain), M_WAITOK | M_ZERO); 5694 sb->ps_callchains = malloc_domainset(pmc_callchaindepth * 5695 pmc_nsamples * sizeof(uintptr_t), M_PMC, 5696 DOMAINSET_PREF(domain), M_WAITOK | M_ZERO); 5697 for (n = 0, ps = sb->ps_samples; n < pmc_nsamples; n++, ps++) 5698 ps->ps_pc = sb->ps_callchains + n * pmc_callchaindepth; 5699 5700 pmc_pcpu[cpu]->pc_sb[PMC_UR] = sb; 5701 } 5702 5703 /* allocate space for the row disposition array */ 5704 pmc_pmcdisp = malloc(sizeof(enum pmc_mode) * md->pmd_npmc, 5705 M_PMC, M_WAITOK|M_ZERO); 5706 5707 /* mark all PMCs as available */ 5708 for (n = 0; n < (int) md->pmd_npmc; n++) 5709 PMC_MARK_ROW_FREE(n); 5710 5711 /* allocate thread hash tables */ 5712 pmc_ownerhash = hashinit(pmc_hashsize, M_PMC, 5713 &pmc_ownerhashmask); 5714 5715 pmc_processhash = hashinit(pmc_hashsize, M_PMC, 5716 &pmc_processhashmask); 5717 mtx_init(&pmc_processhash_mtx, "pmc-process-hash", "pmc-leaf", 5718 MTX_SPIN); 5719 5720 CK_LIST_INIT(&pmc_ss_owners); 5721 pmc_ss_count = 0; 5722 5723 /* allocate a pool of spin mutexes */ 5724 pmc_mtxpool = mtx_pool_create("pmc-leaf", pmc_mtxpool_size, 5725 MTX_SPIN); 5726 5727 PMCDBG4(MOD,INI,1, "pmc_ownerhash=%p, mask=0x%lx " 5728 "targethash=%p mask=0x%lx", pmc_ownerhash, pmc_ownerhashmask, 5729 pmc_processhash, pmc_processhashmask); 5730 5731 /* Initialize a spin mutex for the thread free list. */ 5732 mtx_init(&pmc_threadfreelist_mtx, "pmc-threadfreelist", "pmc-leaf", 5733 MTX_SPIN); 5734 5735 /* Initialize the task to prune the thread free list. */ 5736 TASK_INIT(&free_task, 0, pmc_thread_descriptor_pool_free_task, NULL); 5737 5738 /* register process {exit,fork,exec} handlers */ 5739 pmc_exit_tag = EVENTHANDLER_REGISTER(process_exit, 5740 pmc_process_exit, NULL, EVENTHANDLER_PRI_ANY); 5741 pmc_fork_tag = EVENTHANDLER_REGISTER(process_fork, 5742 pmc_process_fork, NULL, EVENTHANDLER_PRI_ANY); 5743 5744 /* register kld event handlers */ 5745 pmc_kld_load_tag = EVENTHANDLER_REGISTER(kld_load, pmc_kld_load, 5746 NULL, EVENTHANDLER_PRI_ANY); 5747 pmc_kld_unload_tag = EVENTHANDLER_REGISTER(kld_unload, pmc_kld_unload, 5748 NULL, EVENTHANDLER_PRI_ANY); 5749 5750 /* initialize logging */ 5751 pmclog_initialize(); 5752 5753 /* set hook functions */ 5754 pmc_intr = md->pmd_intr; 5755 wmb(); 5756 pmc_hook = pmc_hook_handler; 5757 5758 if (error == 0) { 5759 printf(PMC_MODULE_NAME ":"); 5760 for (n = 0; n < (int) md->pmd_nclass; n++) { 5761 if (md->pmd_classdep[n].pcd_num == 0) 5762 continue; 5763 pcd = &md->pmd_classdep[n]; 5764 printf(" %s/%d/%d/0x%b", 5765 pmc_name_of_pmcclass(pcd->pcd_class), 5766 pcd->pcd_num, 5767 pcd->pcd_width, 5768 pcd->pcd_caps, 5769 "\20" 5770 "\1INT\2USR\3SYS\4EDG\5THR" 5771 "\6REA\7WRI\10INV\11QUA\12PRC" 5772 "\13TAG\14CSC"); 5773 } 5774 printf("\n"); 5775 } 5776 5777 return (error); 5778 } 5779 5780 /* prepare to be unloaded */ 5781 static void 5782 pmc_cleanup(void) 5783 { 5784 int c, cpu; 5785 unsigned int maxcpu; 5786 struct pmc_ownerhash *ph; 5787 struct pmc_owner *po, *tmp; 5788 struct pmc_binding pb; 5789 #ifdef HWPMC_DEBUG 5790 struct pmc_processhash *prh; 5791 #endif 5792 5793 PMCDBG0(MOD,INI,0, "cleanup"); 5794 5795 /* switch off sampling */ 5796 CPU_FOREACH(cpu) 5797 DPCPU_ID_SET(cpu, pmc_sampled, 0); 5798 pmc_intr = NULL; 5799 5800 sx_xlock(&pmc_sx); 5801 if (pmc_hook == NULL) { /* being unloaded already */ 5802 sx_xunlock(&pmc_sx); 5803 return; 5804 } 5805 5806 pmc_hook = NULL; /* prevent new threads from entering module */ 5807 5808 /* deregister event handlers */ 5809 EVENTHANDLER_DEREGISTER(process_fork, pmc_fork_tag); 5810 EVENTHANDLER_DEREGISTER(process_exit, pmc_exit_tag); 5811 EVENTHANDLER_DEREGISTER(kld_load, pmc_kld_load_tag); 5812 EVENTHANDLER_DEREGISTER(kld_unload, pmc_kld_unload_tag); 5813 5814 /* send SIGBUS to all owner threads, free up allocations */ 5815 if (pmc_ownerhash) 5816 for (ph = pmc_ownerhash; 5817 ph <= &pmc_ownerhash[pmc_ownerhashmask]; 5818 ph++) { 5819 LIST_FOREACH_SAFE(po, ph, po_next, tmp) { 5820 pmc_remove_owner(po); 5821 5822 /* send SIGBUS to owner processes */ 5823 PMCDBG3(MOD,INI,2, "cleanup signal proc=%p " 5824 "(%d, %s)", po->po_owner, 5825 po->po_owner->p_pid, 5826 po->po_owner->p_comm); 5827 5828 PROC_LOCK(po->po_owner); 5829 kern_psignal(po->po_owner, SIGBUS); 5830 PROC_UNLOCK(po->po_owner); 5831 5832 pmc_destroy_owner_descriptor(po); 5833 } 5834 } 5835 5836 /* reclaim allocated data structures */ 5837 taskqueue_drain(taskqueue_fast, &free_task); 5838 mtx_destroy(&pmc_threadfreelist_mtx); 5839 pmc_thread_descriptor_pool_drain(); 5840 5841 if (pmc_mtxpool) 5842 mtx_pool_destroy(&pmc_mtxpool); 5843 5844 mtx_destroy(&pmc_processhash_mtx); 5845 if (pmc_processhash) { 5846 #ifdef HWPMC_DEBUG 5847 struct pmc_process *pp; 5848 5849 PMCDBG0(MOD,INI,3, "destroy process hash"); 5850 for (prh = pmc_processhash; 5851 prh <= &pmc_processhash[pmc_processhashmask]; 5852 prh++) 5853 LIST_FOREACH(pp, prh, pp_next) 5854 PMCDBG1(MOD,INI,3, "pid=%d", pp->pp_proc->p_pid); 5855 #endif 5856 5857 hashdestroy(pmc_processhash, M_PMC, pmc_processhashmask); 5858 pmc_processhash = NULL; 5859 } 5860 5861 if (pmc_ownerhash) { 5862 PMCDBG0(MOD,INI,3, "destroy owner hash"); 5863 hashdestroy(pmc_ownerhash, M_PMC, pmc_ownerhashmask); 5864 pmc_ownerhash = NULL; 5865 } 5866 5867 KASSERT(CK_LIST_EMPTY(&pmc_ss_owners), 5868 ("[pmc,%d] Global SS owner list not empty", __LINE__)); 5869 KASSERT(pmc_ss_count == 0, 5870 ("[pmc,%d] Global SS count not empty", __LINE__)); 5871 5872 /* do processor and pmc-class dependent cleanup */ 5873 maxcpu = pmc_cpu_max(); 5874 5875 PMCDBG0(MOD,INI,3, "md cleanup"); 5876 if (md) { 5877 pmc_save_cpu_binding(&pb); 5878 for (cpu = 0; cpu < maxcpu; cpu++) { 5879 PMCDBG2(MOD,INI,1,"pmc-cleanup cpu=%d pcs=%p", 5880 cpu, pmc_pcpu[cpu]); 5881 if (!pmc_cpu_is_active(cpu) || pmc_pcpu[cpu] == NULL) 5882 continue; 5883 pmc_select_cpu(cpu); 5884 for (c = 0; c < md->pmd_nclass; c++) 5885 if (md->pmd_classdep[c].pcd_num > 0) 5886 md->pmd_classdep[c].pcd_pcpu_fini(md, 5887 cpu); 5888 } 5889 5890 if (md->pmd_cputype == PMC_CPU_GENERIC) 5891 pmc_generic_cpu_finalize(md); 5892 else 5893 pmc_md_finalize(md); 5894 5895 pmc_mdep_free(md); 5896 md = NULL; 5897 pmc_restore_cpu_binding(&pb); 5898 } 5899 5900 /* Free per-cpu descriptors. */ 5901 for (cpu = 0; cpu < maxcpu; cpu++) { 5902 if (!pmc_cpu_is_active(cpu)) 5903 continue; 5904 KASSERT(pmc_pcpu[cpu]->pc_sb[PMC_HR] != NULL, 5905 ("[pmc,%d] Null hw cpu sample buffer cpu=%d", __LINE__, 5906 cpu)); 5907 KASSERT(pmc_pcpu[cpu]->pc_sb[PMC_SR] != NULL, 5908 ("[pmc,%d] Null sw cpu sample buffer cpu=%d", __LINE__, 5909 cpu)); 5910 KASSERT(pmc_pcpu[cpu]->pc_sb[PMC_UR] != NULL, 5911 ("[pmc,%d] Null userret cpu sample buffer cpu=%d", __LINE__, 5912 cpu)); 5913 free(pmc_pcpu[cpu]->pc_sb[PMC_HR]->ps_callchains, M_PMC); 5914 free(pmc_pcpu[cpu]->pc_sb[PMC_HR], M_PMC); 5915 free(pmc_pcpu[cpu]->pc_sb[PMC_SR]->ps_callchains, M_PMC); 5916 free(pmc_pcpu[cpu]->pc_sb[PMC_SR], M_PMC); 5917 free(pmc_pcpu[cpu]->pc_sb[PMC_UR]->ps_callchains, M_PMC); 5918 free(pmc_pcpu[cpu]->pc_sb[PMC_UR], M_PMC); 5919 free(pmc_pcpu[cpu], M_PMC); 5920 } 5921 5922 free(pmc_pcpu, M_PMC); 5923 pmc_pcpu = NULL; 5924 5925 free(pmc_pcpu_saved, M_PMC); 5926 pmc_pcpu_saved = NULL; 5927 5928 if (pmc_pmcdisp) { 5929 free(pmc_pmcdisp, M_PMC); 5930 pmc_pmcdisp = NULL; 5931 } 5932 5933 if (pmc_rowindex_to_classdep) { 5934 free(pmc_rowindex_to_classdep, M_PMC); 5935 pmc_rowindex_to_classdep = NULL; 5936 } 5937 5938 pmclog_shutdown(); 5939 counter_u64_free(pmc_stats.pm_intr_ignored); 5940 counter_u64_free(pmc_stats.pm_intr_processed); 5941 counter_u64_free(pmc_stats.pm_intr_bufferfull); 5942 counter_u64_free(pmc_stats.pm_syscalls); 5943 counter_u64_free(pmc_stats.pm_syscall_errors); 5944 counter_u64_free(pmc_stats.pm_buffer_requests); 5945 counter_u64_free(pmc_stats.pm_buffer_requests_failed); 5946 counter_u64_free(pmc_stats.pm_log_sweeps); 5947 counter_u64_free(pmc_stats.pm_merges); 5948 counter_u64_free(pmc_stats.pm_overwrites); 5949 sx_xunlock(&pmc_sx); /* we are done */ 5950 } 5951 5952 /* 5953 * The function called at load/unload. 5954 */ 5955 5956 static int 5957 load (struct module *module __unused, int cmd, void *arg __unused) 5958 { 5959 int error; 5960 5961 error = 0; 5962 5963 switch (cmd) { 5964 case MOD_LOAD : 5965 /* initialize the subsystem */ 5966 error = pmc_initialize(); 5967 if (error != 0) 5968 break; 5969 PMCDBG2(MOD,INI,1, "syscall=%d maxcpu=%d", 5970 pmc_syscall_num, pmc_cpu_max()); 5971 break; 5972 5973 5974 case MOD_UNLOAD : 5975 case MOD_SHUTDOWN: 5976 pmc_cleanup(); 5977 PMCDBG0(MOD,INI,1, "unloaded"); 5978 break; 5979 5980 default : 5981 error = EINVAL; /* XXX should panic(9) */ 5982 break; 5983 } 5984 5985 return error; 5986 } 5987