1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2003-2008 Joseph Koshy 5 * Copyright (c) 2007 The FreeBSD Foundation 6 * All rights reserved. 7 * 8 * Portions of this software were developed by A. Joseph Koshy under 9 * sponsorship from the FreeBSD Foundation and Google, Inc. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 */ 33 34 #include <sys/cdefs.h> 35 __FBSDID("$FreeBSD$"); 36 37 #include <sys/param.h> 38 #include <sys/eventhandler.h> 39 #include <sys/jail.h> 40 #include <sys/kernel.h> 41 #include <sys/kthread.h> 42 #include <sys/limits.h> 43 #include <sys/lock.h> 44 #include <sys/malloc.h> 45 #include <sys/module.h> 46 #include <sys/mount.h> 47 #include <sys/mutex.h> 48 #include <sys/pmc.h> 49 #include <sys/pmckern.h> 50 #include <sys/pmclog.h> 51 #include <sys/priv.h> 52 #include <sys/proc.h> 53 #include <sys/queue.h> 54 #include <sys/resourcevar.h> 55 #include <sys/rwlock.h> 56 #include <sys/sched.h> 57 #include <sys/signalvar.h> 58 #include <sys/smp.h> 59 #include <sys/sx.h> 60 #include <sys/sysctl.h> 61 #include <sys/sysent.h> 62 #include <sys/systm.h> 63 #include <sys/vnode.h> 64 65 #include <sys/linker.h> /* needs to be after <sys/malloc.h> */ 66 67 #include <machine/atomic.h> 68 #include <machine/md_var.h> 69 70 #include <vm/vm.h> 71 #include <vm/vm_extern.h> 72 #include <vm/pmap.h> 73 #include <vm/vm_map.h> 74 #include <vm/vm_object.h> 75 76 #include "hwpmc_soft.h" 77 78 /* 79 * Types 80 */ 81 82 enum pmc_flags { 83 PMC_FLAG_NONE = 0x00, /* do nothing */ 84 PMC_FLAG_REMOVE = 0x01, /* atomically remove entry from hash */ 85 PMC_FLAG_ALLOCATE = 0x02, /* add entry to hash if not found */ 86 }; 87 88 /* 89 * The offset in sysent where the syscall is allocated. 90 */ 91 92 static int pmc_syscall_num = NO_SYSCALL; 93 struct pmc_cpu **pmc_pcpu; /* per-cpu state */ 94 pmc_value_t *pmc_pcpu_saved; /* saved PMC values: CSW handling */ 95 96 #define PMC_PCPU_SAVED(C,R) pmc_pcpu_saved[(R) + md->pmd_npmc*(C)] 97 98 struct mtx_pool *pmc_mtxpool; 99 static int *pmc_pmcdisp; /* PMC row dispositions */ 100 101 #define PMC_ROW_DISP_IS_FREE(R) (pmc_pmcdisp[(R)] == 0) 102 #define PMC_ROW_DISP_IS_THREAD(R) (pmc_pmcdisp[(R)] > 0) 103 #define PMC_ROW_DISP_IS_STANDALONE(R) (pmc_pmcdisp[(R)] < 0) 104 105 #define PMC_MARK_ROW_FREE(R) do { \ 106 pmc_pmcdisp[(R)] = 0; \ 107 } while (0) 108 109 #define PMC_MARK_ROW_STANDALONE(R) do { \ 110 KASSERT(pmc_pmcdisp[(R)] <= 0, ("[pmc,%d] row disposition error", \ 111 __LINE__)); \ 112 atomic_add_int(&pmc_pmcdisp[(R)], -1); \ 113 KASSERT(pmc_pmcdisp[(R)] >= (-pmc_cpu_max_active()), \ 114 ("[pmc,%d] row disposition error", __LINE__)); \ 115 } while (0) 116 117 #define PMC_UNMARK_ROW_STANDALONE(R) do { \ 118 atomic_add_int(&pmc_pmcdisp[(R)], 1); \ 119 KASSERT(pmc_pmcdisp[(R)] <= 0, ("[pmc,%d] row disposition error", \ 120 __LINE__)); \ 121 } while (0) 122 123 #define PMC_MARK_ROW_THREAD(R) do { \ 124 KASSERT(pmc_pmcdisp[(R)] >= 0, ("[pmc,%d] row disposition error", \ 125 __LINE__)); \ 126 atomic_add_int(&pmc_pmcdisp[(R)], 1); \ 127 } while (0) 128 129 #define PMC_UNMARK_ROW_THREAD(R) do { \ 130 atomic_add_int(&pmc_pmcdisp[(R)], -1); \ 131 KASSERT(pmc_pmcdisp[(R)] >= 0, ("[pmc,%d] row disposition error", \ 132 __LINE__)); \ 133 } while (0) 134 135 136 /* various event handlers */ 137 static eventhandler_tag pmc_exit_tag, pmc_fork_tag, pmc_kld_load_tag, 138 pmc_kld_unload_tag; 139 140 /* Module statistics */ 141 struct pmc_op_getdriverstats pmc_stats; 142 143 /* Machine/processor dependent operations */ 144 static struct pmc_mdep *md; 145 146 /* 147 * Hash tables mapping owner processes and target threads to PMCs. 148 */ 149 150 struct mtx pmc_processhash_mtx; /* spin mutex */ 151 static u_long pmc_processhashmask; 152 static LIST_HEAD(pmc_processhash, pmc_process) *pmc_processhash; 153 154 /* 155 * Hash table of PMC owner descriptors. This table is protected by 156 * the shared PMC "sx" lock. 157 */ 158 159 static u_long pmc_ownerhashmask; 160 static LIST_HEAD(pmc_ownerhash, pmc_owner) *pmc_ownerhash; 161 162 /* 163 * List of PMC owners with system-wide sampling PMCs. 164 */ 165 166 static LIST_HEAD(, pmc_owner) pmc_ss_owners; 167 168 169 /* 170 * A map of row indices to classdep structures. 171 */ 172 static struct pmc_classdep **pmc_rowindex_to_classdep; 173 174 /* 175 * Prototypes 176 */ 177 178 #ifdef HWPMC_DEBUG 179 static int pmc_debugflags_sysctl_handler(SYSCTL_HANDLER_ARGS); 180 static int pmc_debugflags_parse(char *newstr, char *fence); 181 #endif 182 183 static int load(struct module *module, int cmd, void *arg); 184 static int pmc_attach_process(struct proc *p, struct pmc *pm); 185 static struct pmc *pmc_allocate_pmc_descriptor(void); 186 static struct pmc_owner *pmc_allocate_owner_descriptor(struct proc *p); 187 static int pmc_attach_one_process(struct proc *p, struct pmc *pm); 188 static int pmc_can_allocate_rowindex(struct proc *p, unsigned int ri, 189 int cpu); 190 static int pmc_can_attach(struct pmc *pm, struct proc *p); 191 static void pmc_capture_user_callchain(int cpu, int soft, struct trapframe *tf); 192 static void pmc_cleanup(void); 193 static int pmc_detach_process(struct proc *p, struct pmc *pm); 194 static int pmc_detach_one_process(struct proc *p, struct pmc *pm, 195 int flags); 196 static void pmc_destroy_owner_descriptor(struct pmc_owner *po); 197 static void pmc_destroy_pmc_descriptor(struct pmc *pm); 198 static struct pmc_owner *pmc_find_owner_descriptor(struct proc *p); 199 static int pmc_find_pmc(pmc_id_t pmcid, struct pmc **pm); 200 static struct pmc *pmc_find_pmc_descriptor_in_process(struct pmc_owner *po, 201 pmc_id_t pmc); 202 static struct pmc_process *pmc_find_process_descriptor(struct proc *p, 203 uint32_t mode); 204 static void pmc_force_context_switch(void); 205 static void pmc_link_target_process(struct pmc *pm, 206 struct pmc_process *pp); 207 static void pmc_log_all_process_mappings(struct pmc_owner *po); 208 static void pmc_log_kernel_mappings(struct pmc *pm); 209 static void pmc_log_process_mappings(struct pmc_owner *po, struct proc *p); 210 static void pmc_maybe_remove_owner(struct pmc_owner *po); 211 static void pmc_process_csw_in(struct thread *td); 212 static void pmc_process_csw_out(struct thread *td); 213 static void pmc_process_exit(void *arg, struct proc *p); 214 static void pmc_process_fork(void *arg, struct proc *p1, 215 struct proc *p2, int n); 216 static void pmc_process_samples(int cpu, int soft); 217 static void pmc_release_pmc_descriptor(struct pmc *pmc); 218 static void pmc_remove_owner(struct pmc_owner *po); 219 static void pmc_remove_process_descriptor(struct pmc_process *pp); 220 static void pmc_restore_cpu_binding(struct pmc_binding *pb); 221 static void pmc_save_cpu_binding(struct pmc_binding *pb); 222 static void pmc_select_cpu(int cpu); 223 static int pmc_start(struct pmc *pm); 224 static int pmc_stop(struct pmc *pm); 225 static int pmc_syscall_handler(struct thread *td, void *syscall_args); 226 static void pmc_unlink_target_process(struct pmc *pmc, 227 struct pmc_process *pp); 228 static int generic_switch_in(struct pmc_cpu *pc, struct pmc_process *pp); 229 static int generic_switch_out(struct pmc_cpu *pc, struct pmc_process *pp); 230 static struct pmc_mdep *pmc_generic_cpu_initialize(void); 231 static void pmc_generic_cpu_finalize(struct pmc_mdep *md); 232 233 /* 234 * Kernel tunables and sysctl(8) interface. 235 */ 236 237 SYSCTL_DECL(_kern_hwpmc); 238 239 static int pmc_callchaindepth = PMC_CALLCHAIN_DEPTH; 240 SYSCTL_INT(_kern_hwpmc, OID_AUTO, callchaindepth, CTLFLAG_RDTUN, 241 &pmc_callchaindepth, 0, "depth of call chain records"); 242 243 #ifdef HWPMC_DEBUG 244 struct pmc_debugflags pmc_debugflags = PMC_DEBUG_DEFAULT_FLAGS; 245 char pmc_debugstr[PMC_DEBUG_STRSIZE]; 246 TUNABLE_STR(PMC_SYSCTL_NAME_PREFIX "debugflags", pmc_debugstr, 247 sizeof(pmc_debugstr)); 248 SYSCTL_PROC(_kern_hwpmc, OID_AUTO, debugflags, 249 CTLTYPE_STRING | CTLFLAG_RWTUN | CTLFLAG_NOFETCH, 250 0, 0, pmc_debugflags_sysctl_handler, "A", "debug flags"); 251 #endif 252 253 /* 254 * kern.hwpmc.hashrows -- determines the number of rows in the 255 * of the hash table used to look up threads 256 */ 257 258 static int pmc_hashsize = PMC_HASH_SIZE; 259 SYSCTL_INT(_kern_hwpmc, OID_AUTO, hashsize, CTLFLAG_RDTUN, 260 &pmc_hashsize, 0, "rows in hash tables"); 261 262 /* 263 * kern.hwpmc.nsamples --- number of PC samples/callchain stacks per CPU 264 */ 265 266 static int pmc_nsamples = PMC_NSAMPLES; 267 SYSCTL_INT(_kern_hwpmc, OID_AUTO, nsamples, CTLFLAG_RDTUN, 268 &pmc_nsamples, 0, "number of PC samples per CPU"); 269 270 271 /* 272 * kern.hwpmc.mtxpoolsize -- number of mutexes in the mutex pool. 273 */ 274 275 static int pmc_mtxpool_size = PMC_MTXPOOL_SIZE; 276 SYSCTL_INT(_kern_hwpmc, OID_AUTO, mtxpoolsize, CTLFLAG_RDTUN, 277 &pmc_mtxpool_size, 0, "size of spin mutex pool"); 278 279 280 /* 281 * security.bsd.unprivileged_syspmcs -- allow non-root processes to 282 * allocate system-wide PMCs. 283 * 284 * Allowing unprivileged processes to allocate system PMCs is convenient 285 * if system-wide measurements need to be taken concurrently with other 286 * per-process measurements. This feature is turned off by default. 287 */ 288 289 static int pmc_unprivileged_syspmcs = 0; 290 SYSCTL_INT(_security_bsd, OID_AUTO, unprivileged_syspmcs, CTLFLAG_RWTUN, 291 &pmc_unprivileged_syspmcs, 0, 292 "allow unprivileged process to allocate system PMCs"); 293 294 /* 295 * Hash function. Discard the lower 2 bits of the pointer since 296 * these are always zero for our uses. The hash multiplier is 297 * round((2^LONG_BIT) * ((sqrt(5)-1)/2)). 298 */ 299 300 #if LONG_BIT == 64 301 #define _PMC_HM 11400714819323198486u 302 #elif LONG_BIT == 32 303 #define _PMC_HM 2654435769u 304 #else 305 #error Must know the size of 'long' to compile 306 #endif 307 308 #define PMC_HASH_PTR(P,M) ((((unsigned long) (P) >> 2) * _PMC_HM) & (M)) 309 310 /* 311 * Syscall structures 312 */ 313 314 /* The `sysent' for the new syscall */ 315 static struct sysent pmc_sysent = { 316 .sy_narg = 2, 317 .sy_call = pmc_syscall_handler, 318 }; 319 320 static struct syscall_module_data pmc_syscall_mod = { 321 .chainevh = load, 322 .chainarg = NULL, 323 .offset = &pmc_syscall_num, 324 .new_sysent = &pmc_sysent, 325 .old_sysent = { .sy_narg = 0, .sy_call = NULL }, 326 .flags = SY_THR_STATIC_KLD, 327 }; 328 329 static moduledata_t pmc_mod = { 330 .name = PMC_MODULE_NAME, 331 .evhand = syscall_module_handler, 332 .priv = &pmc_syscall_mod, 333 }; 334 335 #ifdef EARLY_AP_STARTUP 336 DECLARE_MODULE(pmc, pmc_mod, SI_SUB_SYSCALLS, SI_ORDER_ANY); 337 #else 338 DECLARE_MODULE(pmc, pmc_mod, SI_SUB_SMP, SI_ORDER_ANY); 339 #endif 340 MODULE_VERSION(pmc, PMC_VERSION); 341 342 #ifdef HWPMC_DEBUG 343 enum pmc_dbgparse_state { 344 PMCDS_WS, /* in whitespace */ 345 PMCDS_MAJOR, /* seen a major keyword */ 346 PMCDS_MINOR 347 }; 348 349 static int 350 pmc_debugflags_parse(char *newstr, char *fence) 351 { 352 char c, *p, *q; 353 struct pmc_debugflags *tmpflags; 354 int error, found, *newbits, tmp; 355 size_t kwlen; 356 357 tmpflags = malloc(sizeof(*tmpflags), M_PMC, M_WAITOK|M_ZERO); 358 359 p = newstr; 360 error = 0; 361 362 for (; p < fence && (c = *p); p++) { 363 364 /* skip white space */ 365 if (c == ' ' || c == '\t') 366 continue; 367 368 /* look for a keyword followed by "=" */ 369 for (q = p; p < fence && (c = *p) && c != '='; p++) 370 ; 371 if (c != '=') { 372 error = EINVAL; 373 goto done; 374 } 375 376 kwlen = p - q; 377 newbits = NULL; 378 379 /* lookup flag group name */ 380 #define DBG_SET_FLAG_MAJ(S,F) \ 381 if (kwlen == sizeof(S)-1 && strncmp(q, S, kwlen) == 0) \ 382 newbits = &tmpflags->pdb_ ## F; 383 384 DBG_SET_FLAG_MAJ("cpu", CPU); 385 DBG_SET_FLAG_MAJ("csw", CSW); 386 DBG_SET_FLAG_MAJ("logging", LOG); 387 DBG_SET_FLAG_MAJ("module", MOD); 388 DBG_SET_FLAG_MAJ("md", MDP); 389 DBG_SET_FLAG_MAJ("owner", OWN); 390 DBG_SET_FLAG_MAJ("pmc", PMC); 391 DBG_SET_FLAG_MAJ("process", PRC); 392 DBG_SET_FLAG_MAJ("sampling", SAM); 393 394 if (newbits == NULL) { 395 error = EINVAL; 396 goto done; 397 } 398 399 p++; /* skip the '=' */ 400 401 /* Now parse the individual flags */ 402 tmp = 0; 403 newflag: 404 for (q = p; p < fence && (c = *p); p++) 405 if (c == ' ' || c == '\t' || c == ',') 406 break; 407 408 /* p == fence or c == ws or c == "," or c == 0 */ 409 410 if ((kwlen = p - q) == 0) { 411 *newbits = tmp; 412 continue; 413 } 414 415 found = 0; 416 #define DBG_SET_FLAG_MIN(S,F) \ 417 if (kwlen == sizeof(S)-1 && strncmp(q, S, kwlen) == 0) \ 418 tmp |= found = (1 << PMC_DEBUG_MIN_ ## F) 419 420 /* a '*' denotes all possible flags in the group */ 421 if (kwlen == 1 && *q == '*') 422 tmp = found = ~0; 423 /* look for individual flag names */ 424 DBG_SET_FLAG_MIN("allocaterow", ALR); 425 DBG_SET_FLAG_MIN("allocate", ALL); 426 DBG_SET_FLAG_MIN("attach", ATT); 427 DBG_SET_FLAG_MIN("bind", BND); 428 DBG_SET_FLAG_MIN("config", CFG); 429 DBG_SET_FLAG_MIN("exec", EXC); 430 DBG_SET_FLAG_MIN("exit", EXT); 431 DBG_SET_FLAG_MIN("find", FND); 432 DBG_SET_FLAG_MIN("flush", FLS); 433 DBG_SET_FLAG_MIN("fork", FRK); 434 DBG_SET_FLAG_MIN("getbuf", GTB); 435 DBG_SET_FLAG_MIN("hook", PMH); 436 DBG_SET_FLAG_MIN("init", INI); 437 DBG_SET_FLAG_MIN("intr", INT); 438 DBG_SET_FLAG_MIN("linktarget", TLK); 439 DBG_SET_FLAG_MIN("mayberemove", OMR); 440 DBG_SET_FLAG_MIN("ops", OPS); 441 DBG_SET_FLAG_MIN("read", REA); 442 DBG_SET_FLAG_MIN("register", REG); 443 DBG_SET_FLAG_MIN("release", REL); 444 DBG_SET_FLAG_MIN("remove", ORM); 445 DBG_SET_FLAG_MIN("sample", SAM); 446 DBG_SET_FLAG_MIN("scheduleio", SIO); 447 DBG_SET_FLAG_MIN("select", SEL); 448 DBG_SET_FLAG_MIN("signal", SIG); 449 DBG_SET_FLAG_MIN("swi", SWI); 450 DBG_SET_FLAG_MIN("swo", SWO); 451 DBG_SET_FLAG_MIN("start", STA); 452 DBG_SET_FLAG_MIN("stop", STO); 453 DBG_SET_FLAG_MIN("syscall", PMS); 454 DBG_SET_FLAG_MIN("unlinktarget", TUL); 455 DBG_SET_FLAG_MIN("write", WRI); 456 if (found == 0) { 457 /* unrecognized flag name */ 458 error = EINVAL; 459 goto done; 460 } 461 462 if (c == 0 || c == ' ' || c == '\t') { /* end of flag group */ 463 *newbits = tmp; 464 continue; 465 } 466 467 p++; 468 goto newflag; 469 } 470 471 /* save the new flag set */ 472 bcopy(tmpflags, &pmc_debugflags, sizeof(pmc_debugflags)); 473 474 done: 475 free(tmpflags, M_PMC); 476 return error; 477 } 478 479 static int 480 pmc_debugflags_sysctl_handler(SYSCTL_HANDLER_ARGS) 481 { 482 char *fence, *newstr; 483 int error; 484 unsigned int n; 485 486 (void) arg1; (void) arg2; /* unused parameters */ 487 488 n = sizeof(pmc_debugstr); 489 newstr = malloc(n, M_PMC, M_WAITOK|M_ZERO); 490 (void) strlcpy(newstr, pmc_debugstr, n); 491 492 error = sysctl_handle_string(oidp, newstr, n, req); 493 494 /* if there is a new string, parse and copy it */ 495 if (error == 0 && req->newptr != NULL) { 496 fence = newstr + (n < req->newlen ? n : req->newlen + 1); 497 if ((error = pmc_debugflags_parse(newstr, fence)) == 0) 498 (void) strlcpy(pmc_debugstr, newstr, 499 sizeof(pmc_debugstr)); 500 } 501 502 free(newstr, M_PMC); 503 504 return error; 505 } 506 #endif 507 508 /* 509 * Map a row index to a classdep structure and return the adjusted row 510 * index for the PMC class index. 511 */ 512 static struct pmc_classdep * 513 pmc_ri_to_classdep(struct pmc_mdep *md, int ri, int *adjri) 514 { 515 struct pmc_classdep *pcd; 516 517 (void) md; 518 519 KASSERT(ri >= 0 && ri < md->pmd_npmc, 520 ("[pmc,%d] illegal row-index %d", __LINE__, ri)); 521 522 pcd = pmc_rowindex_to_classdep[ri]; 523 524 KASSERT(pcd != NULL, 525 ("[pmc,%d] ri %d null pcd", __LINE__, ri)); 526 527 *adjri = ri - pcd->pcd_ri; 528 529 KASSERT(*adjri >= 0 && *adjri < pcd->pcd_num, 530 ("[pmc,%d] adjusted row-index %d", __LINE__, *adjri)); 531 532 return (pcd); 533 } 534 535 /* 536 * Concurrency Control 537 * 538 * The driver manages the following data structures: 539 * 540 * - target process descriptors, one per target process 541 * - owner process descriptors (and attached lists), one per owner process 542 * - lookup hash tables for owner and target processes 543 * - PMC descriptors (and attached lists) 544 * - per-cpu hardware state 545 * - the 'hook' variable through which the kernel calls into 546 * this module 547 * - the machine hardware state (managed by the MD layer) 548 * 549 * These data structures are accessed from: 550 * 551 * - thread context-switch code 552 * - interrupt handlers (possibly on multiple cpus) 553 * - kernel threads on multiple cpus running on behalf of user 554 * processes doing system calls 555 * - this driver's private kernel threads 556 * 557 * = Locks and Locking strategy = 558 * 559 * The driver uses four locking strategies for its operation: 560 * 561 * - The global SX lock "pmc_sx" is used to protect internal 562 * data structures. 563 * 564 * Calls into the module by syscall() start with this lock being 565 * held in exclusive mode. Depending on the requested operation, 566 * the lock may be downgraded to 'shared' mode to allow more 567 * concurrent readers into the module. Calls into the module from 568 * other parts of the kernel acquire the lock in shared mode. 569 * 570 * This SX lock is held in exclusive mode for any operations that 571 * modify the linkages between the driver's internal data structures. 572 * 573 * The 'pmc_hook' function pointer is also protected by this lock. 574 * It is only examined with the sx lock held in exclusive mode. The 575 * kernel module is allowed to be unloaded only with the sx lock held 576 * in exclusive mode. In normal syscall handling, after acquiring the 577 * pmc_sx lock we first check that 'pmc_hook' is non-null before 578 * proceeding. This prevents races between the thread unloading the module 579 * and other threads seeking to use the module. 580 * 581 * - Lookups of target process structures and owner process structures 582 * cannot use the global "pmc_sx" SX lock because these lookups need 583 * to happen during context switches and in other critical sections 584 * where sleeping is not allowed. We protect these lookup tables 585 * with their own private spin-mutexes, "pmc_processhash_mtx" and 586 * "pmc_ownerhash_mtx". 587 * 588 * - Interrupt handlers work in a lock free manner. At interrupt 589 * time, handlers look at the PMC pointer (phw->phw_pmc) configured 590 * when the PMC was started. If this pointer is NULL, the interrupt 591 * is ignored after updating driver statistics. We ensure that this 592 * pointer is set (using an atomic operation if necessary) before the 593 * PMC hardware is started. Conversely, this pointer is unset atomically 594 * only after the PMC hardware is stopped. 595 * 596 * We ensure that everything needed for the operation of an 597 * interrupt handler is available without it needing to acquire any 598 * locks. We also ensure that a PMC's software state is destroyed only 599 * after the PMC is taken off hardware (on all CPUs). 600 * 601 * - Context-switch handling with process-private PMCs needs more 602 * care. 603 * 604 * A given process may be the target of multiple PMCs. For example, 605 * PMCATTACH and PMCDETACH may be requested by a process on one CPU 606 * while the target process is running on another. A PMC could also 607 * be getting released because its owner is exiting. We tackle 608 * these situations in the following manner: 609 * 610 * - each target process structure 'pmc_process' has an array 611 * of 'struct pmc *' pointers, one for each hardware PMC. 612 * 613 * - At context switch IN time, each "target" PMC in RUNNING state 614 * gets started on hardware and a pointer to each PMC is copied into 615 * the per-cpu phw array. The 'runcount' for the PMC is 616 * incremented. 617 * 618 * - At context switch OUT time, all process-virtual PMCs are stopped 619 * on hardware. The saved value is added to the PMCs value field 620 * only if the PMC is in a non-deleted state (the PMCs state could 621 * have changed during the current time slice). 622 * 623 * Note that since in-between a switch IN on a processor and a switch 624 * OUT, the PMC could have been released on another CPU. Therefore 625 * context switch OUT always looks at the hardware state to turn 626 * OFF PMCs and will update a PMC's saved value only if reachable 627 * from the target process record. 628 * 629 * - OP PMCRELEASE could be called on a PMC at any time (the PMC could 630 * be attached to many processes at the time of the call and could 631 * be active on multiple CPUs). 632 * 633 * We prevent further scheduling of the PMC by marking it as in 634 * state 'DELETED'. If the runcount of the PMC is non-zero then 635 * this PMC is currently running on a CPU somewhere. The thread 636 * doing the PMCRELEASE operation waits by repeatedly doing a 637 * pause() till the runcount comes to zero. 638 * 639 * The contents of a PMC descriptor (struct pmc) are protected using 640 * a spin-mutex. In order to save space, we use a mutex pool. 641 * 642 * In terms of lock types used by witness(4), we use: 643 * - Type "pmc-sx", used by the global SX lock. 644 * - Type "pmc-sleep", for sleep mutexes used by logger threads. 645 * - Type "pmc-per-proc", for protecting PMC owner descriptors. 646 * - Type "pmc-leaf", used for all other spin mutexes. 647 */ 648 649 /* 650 * save the cpu binding of the current kthread 651 */ 652 653 static void 654 pmc_save_cpu_binding(struct pmc_binding *pb) 655 { 656 PMCDBG0(CPU,BND,2, "save-cpu"); 657 thread_lock(curthread); 658 pb->pb_bound = sched_is_bound(curthread); 659 pb->pb_cpu = curthread->td_oncpu; 660 thread_unlock(curthread); 661 PMCDBG1(CPU,BND,2, "save-cpu cpu=%d", pb->pb_cpu); 662 } 663 664 /* 665 * restore the cpu binding of the current thread 666 */ 667 668 static void 669 pmc_restore_cpu_binding(struct pmc_binding *pb) 670 { 671 PMCDBG2(CPU,BND,2, "restore-cpu curcpu=%d restore=%d", 672 curthread->td_oncpu, pb->pb_cpu); 673 thread_lock(curthread); 674 if (pb->pb_bound) 675 sched_bind(curthread, pb->pb_cpu); 676 else 677 sched_unbind(curthread); 678 thread_unlock(curthread); 679 PMCDBG0(CPU,BND,2, "restore-cpu done"); 680 } 681 682 /* 683 * move execution over the specified cpu and bind it there. 684 */ 685 686 static void 687 pmc_select_cpu(int cpu) 688 { 689 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 690 ("[pmc,%d] bad cpu number %d", __LINE__, cpu)); 691 692 /* Never move to an inactive CPU. */ 693 KASSERT(pmc_cpu_is_active(cpu), ("[pmc,%d] selecting inactive " 694 "CPU %d", __LINE__, cpu)); 695 696 PMCDBG1(CPU,SEL,2, "select-cpu cpu=%d", cpu); 697 thread_lock(curthread); 698 sched_bind(curthread, cpu); 699 thread_unlock(curthread); 700 701 KASSERT(curthread->td_oncpu == cpu, 702 ("[pmc,%d] CPU not bound [cpu=%d, curr=%d]", __LINE__, 703 cpu, curthread->td_oncpu)); 704 705 PMCDBG1(CPU,SEL,2, "select-cpu cpu=%d ok", cpu); 706 } 707 708 /* 709 * Force a context switch. 710 * 711 * We do this by pause'ing for 1 tick -- invoking mi_switch() is not 712 * guaranteed to force a context switch. 713 */ 714 715 static void 716 pmc_force_context_switch(void) 717 { 718 719 pause("pmcctx", 1); 720 } 721 722 /* 723 * Get the file name for an executable. This is a simple wrapper 724 * around vn_fullpath(9). 725 */ 726 727 static void 728 pmc_getfilename(struct vnode *v, char **fullpath, char **freepath) 729 { 730 731 *fullpath = "unknown"; 732 *freepath = NULL; 733 vn_fullpath(curthread, v, fullpath, freepath); 734 } 735 736 /* 737 * remove an process owning PMCs 738 */ 739 740 void 741 pmc_remove_owner(struct pmc_owner *po) 742 { 743 struct pmc *pm, *tmp; 744 745 sx_assert(&pmc_sx, SX_XLOCKED); 746 747 PMCDBG1(OWN,ORM,1, "remove-owner po=%p", po); 748 749 /* Remove descriptor from the owner hash table */ 750 LIST_REMOVE(po, po_next); 751 752 /* release all owned PMC descriptors */ 753 LIST_FOREACH_SAFE(pm, &po->po_pmcs, pm_next, tmp) { 754 PMCDBG1(OWN,ORM,2, "pmc=%p", pm); 755 KASSERT(pm->pm_owner == po, 756 ("[pmc,%d] owner %p != po %p", __LINE__, pm->pm_owner, po)); 757 758 pmc_release_pmc_descriptor(pm); /* will unlink from the list */ 759 pmc_destroy_pmc_descriptor(pm); 760 } 761 762 KASSERT(po->po_sscount == 0, 763 ("[pmc,%d] SS count not zero", __LINE__)); 764 KASSERT(LIST_EMPTY(&po->po_pmcs), 765 ("[pmc,%d] PMC list not empty", __LINE__)); 766 767 /* de-configure the log file if present */ 768 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 769 pmclog_deconfigure_log(po); 770 } 771 772 /* 773 * remove an owner process record if all conditions are met. 774 */ 775 776 static void 777 pmc_maybe_remove_owner(struct pmc_owner *po) 778 { 779 780 PMCDBG1(OWN,OMR,1, "maybe-remove-owner po=%p", po); 781 782 /* 783 * Remove owner record if 784 * - this process does not own any PMCs 785 * - this process has not allocated a system-wide sampling buffer 786 */ 787 788 if (LIST_EMPTY(&po->po_pmcs) && 789 ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0)) { 790 pmc_remove_owner(po); 791 pmc_destroy_owner_descriptor(po); 792 } 793 } 794 795 /* 796 * Add an association between a target process and a PMC. 797 */ 798 799 static void 800 pmc_link_target_process(struct pmc *pm, struct pmc_process *pp) 801 { 802 int ri; 803 struct pmc_target *pt; 804 805 sx_assert(&pmc_sx, SX_XLOCKED); 806 807 KASSERT(pm != NULL && pp != NULL, 808 ("[pmc,%d] Null pm %p or pp %p", __LINE__, pm, pp)); 809 KASSERT(PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)), 810 ("[pmc,%d] Attaching a non-process-virtual pmc=%p to pid=%d", 811 __LINE__, pm, pp->pp_proc->p_pid)); 812 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= ((int) md->pmd_npmc - 1), 813 ("[pmc,%d] Illegal reference count %d for process record %p", 814 __LINE__, pp->pp_refcnt, (void *) pp)); 815 816 ri = PMC_TO_ROWINDEX(pm); 817 818 PMCDBG3(PRC,TLK,1, "link-target pmc=%p ri=%d pmc-process=%p", 819 pm, ri, pp); 820 821 #ifdef HWPMC_DEBUG 822 LIST_FOREACH(pt, &pm->pm_targets, pt_next) 823 if (pt->pt_process == pp) 824 KASSERT(0, ("[pmc,%d] pp %p already in pmc %p targets", 825 __LINE__, pp, pm)); 826 #endif 827 828 pt = malloc(sizeof(struct pmc_target), M_PMC, M_WAITOK|M_ZERO); 829 pt->pt_process = pp; 830 831 LIST_INSERT_HEAD(&pm->pm_targets, pt, pt_next); 832 833 atomic_store_rel_ptr((uintptr_t *)&pp->pp_pmcs[ri].pp_pmc, 834 (uintptr_t)pm); 835 836 if (pm->pm_owner->po_owner == pp->pp_proc) 837 pm->pm_flags |= PMC_F_ATTACHED_TO_OWNER; 838 839 /* 840 * Initialize the per-process values at this row index. 841 */ 842 pp->pp_pmcs[ri].pp_pmcval = PMC_TO_MODE(pm) == PMC_MODE_TS ? 843 pm->pm_sc.pm_reloadcount : 0; 844 845 pp->pp_refcnt++; 846 847 } 848 849 /* 850 * Removes the association between a target process and a PMC. 851 */ 852 853 static void 854 pmc_unlink_target_process(struct pmc *pm, struct pmc_process *pp) 855 { 856 int ri; 857 struct proc *p; 858 struct pmc_target *ptgt; 859 860 sx_assert(&pmc_sx, SX_XLOCKED); 861 862 KASSERT(pm != NULL && pp != NULL, 863 ("[pmc,%d] Null pm %p or pp %p", __LINE__, pm, pp)); 864 865 KASSERT(pp->pp_refcnt >= 1 && pp->pp_refcnt <= (int) md->pmd_npmc, 866 ("[pmc,%d] Illegal ref count %d on process record %p", 867 __LINE__, pp->pp_refcnt, (void *) pp)); 868 869 ri = PMC_TO_ROWINDEX(pm); 870 871 PMCDBG3(PRC,TUL,1, "unlink-target pmc=%p ri=%d pmc-process=%p", 872 pm, ri, pp); 873 874 KASSERT(pp->pp_pmcs[ri].pp_pmc == pm, 875 ("[pmc,%d] PMC ri %d mismatch pmc %p pp->[ri] %p", __LINE__, 876 ri, pm, pp->pp_pmcs[ri].pp_pmc)); 877 878 pp->pp_pmcs[ri].pp_pmc = NULL; 879 pp->pp_pmcs[ri].pp_pmcval = (pmc_value_t) 0; 880 881 /* Remove owner-specific flags */ 882 if (pm->pm_owner->po_owner == pp->pp_proc) { 883 pp->pp_flags &= ~PMC_PP_ENABLE_MSR_ACCESS; 884 pm->pm_flags &= ~PMC_F_ATTACHED_TO_OWNER; 885 } 886 887 pp->pp_refcnt--; 888 889 /* Remove the target process from the PMC structure */ 890 LIST_FOREACH(ptgt, &pm->pm_targets, pt_next) 891 if (ptgt->pt_process == pp) 892 break; 893 894 KASSERT(ptgt != NULL, ("[pmc,%d] process %p (pp: %p) not found " 895 "in pmc %p", __LINE__, pp->pp_proc, pp, pm)); 896 897 LIST_REMOVE(ptgt, pt_next); 898 free(ptgt, M_PMC); 899 900 /* if the PMC now lacks targets, send the owner a SIGIO */ 901 if (LIST_EMPTY(&pm->pm_targets)) { 902 p = pm->pm_owner->po_owner; 903 PROC_LOCK(p); 904 kern_psignal(p, SIGIO); 905 PROC_UNLOCK(p); 906 907 PMCDBG2(PRC,SIG,2, "signalling proc=%p signal=%d", p, 908 SIGIO); 909 } 910 } 911 912 /* 913 * Check if PMC 'pm' may be attached to target process 't'. 914 */ 915 916 static int 917 pmc_can_attach(struct pmc *pm, struct proc *t) 918 { 919 struct proc *o; /* pmc owner */ 920 struct ucred *oc, *tc; /* owner, target credentials */ 921 int decline_attach, i; 922 923 /* 924 * A PMC's owner can always attach that PMC to itself. 925 */ 926 927 if ((o = pm->pm_owner->po_owner) == t) 928 return 0; 929 930 PROC_LOCK(o); 931 oc = o->p_ucred; 932 crhold(oc); 933 PROC_UNLOCK(o); 934 935 PROC_LOCK(t); 936 tc = t->p_ucred; 937 crhold(tc); 938 PROC_UNLOCK(t); 939 940 /* 941 * The effective uid of the PMC owner should match at least one 942 * of the {effective,real,saved} uids of the target process. 943 */ 944 945 decline_attach = oc->cr_uid != tc->cr_uid && 946 oc->cr_uid != tc->cr_svuid && 947 oc->cr_uid != tc->cr_ruid; 948 949 /* 950 * Every one of the target's group ids, must be in the owner's 951 * group list. 952 */ 953 for (i = 0; !decline_attach && i < tc->cr_ngroups; i++) 954 decline_attach = !groupmember(tc->cr_groups[i], oc); 955 956 /* check the read and saved gids too */ 957 if (decline_attach == 0) 958 decline_attach = !groupmember(tc->cr_rgid, oc) || 959 !groupmember(tc->cr_svgid, oc); 960 961 crfree(tc); 962 crfree(oc); 963 964 return !decline_attach; 965 } 966 967 /* 968 * Attach a process to a PMC. 969 */ 970 971 static int 972 pmc_attach_one_process(struct proc *p, struct pmc *pm) 973 { 974 int ri; 975 char *fullpath, *freepath; 976 struct pmc_process *pp; 977 978 sx_assert(&pmc_sx, SX_XLOCKED); 979 980 PMCDBG5(PRC,ATT,2, "attach-one pm=%p ri=%d proc=%p (%d, %s)", pm, 981 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 982 983 /* 984 * Locate the process descriptor corresponding to process 'p', 985 * allocating space as needed. 986 * 987 * Verify that rowindex 'pm_rowindex' is free in the process 988 * descriptor. 989 * 990 * If not, allocate space for a descriptor and link the 991 * process descriptor and PMC. 992 */ 993 ri = PMC_TO_ROWINDEX(pm); 994 995 if ((pp = pmc_find_process_descriptor(p, PMC_FLAG_ALLOCATE)) == NULL) 996 return ENOMEM; 997 998 if (pp->pp_pmcs[ri].pp_pmc == pm) /* already present at slot [ri] */ 999 return EEXIST; 1000 1001 if (pp->pp_pmcs[ri].pp_pmc != NULL) 1002 return EBUSY; 1003 1004 pmc_link_target_process(pm, pp); 1005 1006 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)) && 1007 (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) == 0) 1008 pm->pm_flags |= PMC_F_NEEDS_LOGFILE; 1009 1010 pm->pm_flags |= PMC_F_ATTACH_DONE; /* mark as attached */ 1011 1012 /* issue an attach event to a configured log file */ 1013 if (pm->pm_owner->po_flags & PMC_PO_OWNS_LOGFILE) { 1014 if (p->p_flag & P_KPROC) { 1015 fullpath = kernelname; 1016 freepath = NULL; 1017 } else { 1018 pmc_getfilename(p->p_textvp, &fullpath, &freepath); 1019 pmclog_process_pmcattach(pm, p->p_pid, fullpath); 1020 } 1021 free(freepath, M_TEMP); 1022 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 1023 pmc_log_process_mappings(pm->pm_owner, p); 1024 } 1025 /* mark process as using HWPMCs */ 1026 PROC_LOCK(p); 1027 p->p_flag |= P_HWPMC; 1028 PROC_UNLOCK(p); 1029 1030 return 0; 1031 } 1032 1033 /* 1034 * Attach a process and optionally its children 1035 */ 1036 1037 static int 1038 pmc_attach_process(struct proc *p, struct pmc *pm) 1039 { 1040 int error; 1041 struct proc *top; 1042 1043 sx_assert(&pmc_sx, SX_XLOCKED); 1044 1045 PMCDBG5(PRC,ATT,1, "attach pm=%p ri=%d proc=%p (%d, %s)", pm, 1046 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 1047 1048 1049 /* 1050 * If this PMC successfully allowed a GETMSR operation 1051 * in the past, disallow further ATTACHes. 1052 */ 1053 1054 if ((pm->pm_flags & PMC_PP_ENABLE_MSR_ACCESS) != 0) 1055 return EPERM; 1056 1057 if ((pm->pm_flags & PMC_F_DESCENDANTS) == 0) 1058 return pmc_attach_one_process(p, pm); 1059 1060 /* 1061 * Traverse all child processes, attaching them to 1062 * this PMC. 1063 */ 1064 1065 sx_slock(&proctree_lock); 1066 1067 top = p; 1068 1069 for (;;) { 1070 if ((error = pmc_attach_one_process(p, pm)) != 0) 1071 break; 1072 if (!LIST_EMPTY(&p->p_children)) 1073 p = LIST_FIRST(&p->p_children); 1074 else for (;;) { 1075 if (p == top) 1076 goto done; 1077 if (LIST_NEXT(p, p_sibling)) { 1078 p = LIST_NEXT(p, p_sibling); 1079 break; 1080 } 1081 p = p->p_pptr; 1082 } 1083 } 1084 1085 if (error) 1086 (void) pmc_detach_process(top, pm); 1087 1088 done: 1089 sx_sunlock(&proctree_lock); 1090 return error; 1091 } 1092 1093 /* 1094 * Detach a process from a PMC. If there are no other PMCs tracking 1095 * this process, remove the process structure from its hash table. If 1096 * 'flags' contains PMC_FLAG_REMOVE, then free the process structure. 1097 */ 1098 1099 static int 1100 pmc_detach_one_process(struct proc *p, struct pmc *pm, int flags) 1101 { 1102 int ri; 1103 struct pmc_process *pp; 1104 1105 sx_assert(&pmc_sx, SX_XLOCKED); 1106 1107 KASSERT(pm != NULL, 1108 ("[pmc,%d] null pm pointer", __LINE__)); 1109 1110 ri = PMC_TO_ROWINDEX(pm); 1111 1112 PMCDBG6(PRC,ATT,2, "detach-one pm=%p ri=%d proc=%p (%d, %s) flags=0x%x", 1113 pm, ri, p, p->p_pid, p->p_comm, flags); 1114 1115 if ((pp = pmc_find_process_descriptor(p, 0)) == NULL) 1116 return ESRCH; 1117 1118 if (pp->pp_pmcs[ri].pp_pmc != pm) 1119 return EINVAL; 1120 1121 pmc_unlink_target_process(pm, pp); 1122 1123 /* Issue a detach entry if a log file is configured */ 1124 if (pm->pm_owner->po_flags & PMC_PO_OWNS_LOGFILE) 1125 pmclog_process_pmcdetach(pm, p->p_pid); 1126 1127 /* 1128 * If there are no PMCs targeting this process, we remove its 1129 * descriptor from the target hash table and unset the P_HWPMC 1130 * flag in the struct proc. 1131 */ 1132 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= (int) md->pmd_npmc, 1133 ("[pmc,%d] Illegal refcnt %d for process struct %p", 1134 __LINE__, pp->pp_refcnt, pp)); 1135 1136 if (pp->pp_refcnt != 0) /* still a target of some PMC */ 1137 return 0; 1138 1139 pmc_remove_process_descriptor(pp); 1140 1141 if (flags & PMC_FLAG_REMOVE) 1142 free(pp, M_PMC); 1143 1144 PROC_LOCK(p); 1145 p->p_flag &= ~P_HWPMC; 1146 PROC_UNLOCK(p); 1147 1148 return 0; 1149 } 1150 1151 /* 1152 * Detach a process and optionally its descendants from a PMC. 1153 */ 1154 1155 static int 1156 pmc_detach_process(struct proc *p, struct pmc *pm) 1157 { 1158 struct proc *top; 1159 1160 sx_assert(&pmc_sx, SX_XLOCKED); 1161 1162 PMCDBG5(PRC,ATT,1, "detach pm=%p ri=%d proc=%p (%d, %s)", pm, 1163 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 1164 1165 if ((pm->pm_flags & PMC_F_DESCENDANTS) == 0) 1166 return pmc_detach_one_process(p, pm, PMC_FLAG_REMOVE); 1167 1168 /* 1169 * Traverse all children, detaching them from this PMC. We 1170 * ignore errors since we could be detaching a PMC from a 1171 * partially attached proc tree. 1172 */ 1173 1174 sx_slock(&proctree_lock); 1175 1176 top = p; 1177 1178 for (;;) { 1179 (void) pmc_detach_one_process(p, pm, PMC_FLAG_REMOVE); 1180 1181 if (!LIST_EMPTY(&p->p_children)) 1182 p = LIST_FIRST(&p->p_children); 1183 else for (;;) { 1184 if (p == top) 1185 goto done; 1186 if (LIST_NEXT(p, p_sibling)) { 1187 p = LIST_NEXT(p, p_sibling); 1188 break; 1189 } 1190 p = p->p_pptr; 1191 } 1192 } 1193 1194 done: 1195 sx_sunlock(&proctree_lock); 1196 1197 if (LIST_EMPTY(&pm->pm_targets)) 1198 pm->pm_flags &= ~PMC_F_ATTACH_DONE; 1199 1200 return 0; 1201 } 1202 1203 1204 /* 1205 * Thread context switch IN 1206 */ 1207 1208 static void 1209 pmc_process_csw_in(struct thread *td) 1210 { 1211 int cpu; 1212 unsigned int adjri, ri; 1213 struct pmc *pm; 1214 struct proc *p; 1215 struct pmc_cpu *pc; 1216 struct pmc_hw *phw; 1217 pmc_value_t newvalue; 1218 struct pmc_process *pp; 1219 struct pmc_classdep *pcd; 1220 1221 p = td->td_proc; 1222 1223 if ((pp = pmc_find_process_descriptor(p, PMC_FLAG_NONE)) == NULL) 1224 return; 1225 1226 KASSERT(pp->pp_proc == td->td_proc, 1227 ("[pmc,%d] not my thread state", __LINE__)); 1228 1229 critical_enter(); /* no preemption from this point */ 1230 1231 cpu = PCPU_GET(cpuid); /* td->td_oncpu is invalid */ 1232 1233 PMCDBG5(CSW,SWI,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p, 1234 p->p_pid, p->p_comm, pp); 1235 1236 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 1237 ("[pmc,%d] weird CPU id %d", __LINE__, cpu)); 1238 1239 pc = pmc_pcpu[cpu]; 1240 1241 for (ri = 0; ri < md->pmd_npmc; ri++) { 1242 1243 if ((pm = pp->pp_pmcs[ri].pp_pmc) == NULL) 1244 continue; 1245 1246 KASSERT(PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)), 1247 ("[pmc,%d] Target PMC in non-virtual mode (%d)", 1248 __LINE__, PMC_TO_MODE(pm))); 1249 1250 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 1251 ("[pmc,%d] Row index mismatch pmc %d != ri %d", 1252 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 1253 1254 /* 1255 * Only PMCs that are marked as 'RUNNING' need 1256 * be placed on hardware. 1257 */ 1258 1259 if (pm->pm_state != PMC_STATE_RUNNING) 1260 continue; 1261 1262 /* increment PMC runcount */ 1263 atomic_add_rel_int(&pm->pm_runcount, 1); 1264 1265 /* configure the HWPMC we are going to use. */ 1266 pcd = pmc_ri_to_classdep(md, ri, &adjri); 1267 pcd->pcd_config_pmc(cpu, adjri, pm); 1268 1269 phw = pc->pc_hwpmcs[ri]; 1270 1271 KASSERT(phw != NULL, 1272 ("[pmc,%d] null hw pointer", __LINE__)); 1273 1274 KASSERT(phw->phw_pmc == pm, 1275 ("[pmc,%d] hw->pmc %p != pmc %p", __LINE__, 1276 phw->phw_pmc, pm)); 1277 1278 /* 1279 * Write out saved value and start the PMC. 1280 * 1281 * Sampling PMCs use a per-process value, while 1282 * counting mode PMCs use a per-pmc value that is 1283 * inherited across descendants. 1284 */ 1285 if (PMC_TO_MODE(pm) == PMC_MODE_TS) { 1286 mtx_pool_lock_spin(pmc_mtxpool, pm); 1287 1288 /* 1289 * Use the saved value calculated after the most recent 1290 * thread switch out to start this counter. Reset 1291 * the saved count in case another thread from this 1292 * process switches in before any threads switch out. 1293 */ 1294 newvalue = PMC_PCPU_SAVED(cpu,ri) = 1295 pp->pp_pmcs[ri].pp_pmcval; 1296 pp->pp_pmcs[ri].pp_pmcval = pm->pm_sc.pm_reloadcount; 1297 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1298 } else { 1299 KASSERT(PMC_TO_MODE(pm) == PMC_MODE_TC, 1300 ("[pmc,%d] illegal mode=%d", __LINE__, 1301 PMC_TO_MODE(pm))); 1302 mtx_pool_lock_spin(pmc_mtxpool, pm); 1303 newvalue = PMC_PCPU_SAVED(cpu, ri) = 1304 pm->pm_gv.pm_savedvalue; 1305 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1306 } 1307 1308 PMCDBG3(CSW,SWI,1,"cpu=%d ri=%d new=%jd", cpu, ri, newvalue); 1309 1310 pcd->pcd_write_pmc(cpu, adjri, newvalue); 1311 1312 /* If a sampling mode PMC, reset stalled state. */ 1313 if (PMC_TO_MODE(pm) == PMC_MODE_TS) 1314 CPU_CLR_ATOMIC(cpu, &pm->pm_stalled); 1315 1316 /* Indicate that we desire this to run. */ 1317 CPU_SET_ATOMIC(cpu, &pm->pm_cpustate); 1318 1319 /* Start the PMC. */ 1320 pcd->pcd_start_pmc(cpu, adjri); 1321 } 1322 1323 /* 1324 * perform any other architecture/cpu dependent thread 1325 * switch-in actions. 1326 */ 1327 1328 (void) (*md->pmd_switch_in)(pc, pp); 1329 1330 critical_exit(); 1331 1332 } 1333 1334 /* 1335 * Thread context switch OUT. 1336 */ 1337 1338 static void 1339 pmc_process_csw_out(struct thread *td) 1340 { 1341 int cpu; 1342 int64_t tmp; 1343 struct pmc *pm; 1344 struct proc *p; 1345 enum pmc_mode mode; 1346 struct pmc_cpu *pc; 1347 pmc_value_t newvalue; 1348 unsigned int adjri, ri; 1349 struct pmc_process *pp; 1350 struct pmc_classdep *pcd; 1351 1352 1353 /* 1354 * Locate our process descriptor; this may be NULL if 1355 * this process is exiting and we have already removed 1356 * the process from the target process table. 1357 * 1358 * Note that due to kernel preemption, multiple 1359 * context switches may happen while the process is 1360 * exiting. 1361 * 1362 * Note also that if the target process cannot be 1363 * found we still need to deconfigure any PMCs that 1364 * are currently running on hardware. 1365 */ 1366 1367 p = td->td_proc; 1368 pp = pmc_find_process_descriptor(p, PMC_FLAG_NONE); 1369 1370 /* 1371 * save PMCs 1372 */ 1373 1374 critical_enter(); 1375 1376 cpu = PCPU_GET(cpuid); /* td->td_oncpu is invalid */ 1377 1378 PMCDBG5(CSW,SWO,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p, 1379 p->p_pid, p->p_comm, pp); 1380 1381 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 1382 ("[pmc,%d weird CPU id %d", __LINE__, cpu)); 1383 1384 pc = pmc_pcpu[cpu]; 1385 1386 /* 1387 * When a PMC gets unlinked from a target PMC, it will 1388 * be removed from the target's pp_pmc[] array. 1389 * 1390 * However, on a MP system, the target could have been 1391 * executing on another CPU at the time of the unlink. 1392 * So, at context switch OUT time, we need to look at 1393 * the hardware to determine if a PMC is scheduled on 1394 * it. 1395 */ 1396 1397 for (ri = 0; ri < md->pmd_npmc; ri++) { 1398 1399 pcd = pmc_ri_to_classdep(md, ri, &adjri); 1400 pm = NULL; 1401 (void) (*pcd->pcd_get_config)(cpu, adjri, &pm); 1402 1403 if (pm == NULL) /* nothing at this row index */ 1404 continue; 1405 1406 mode = PMC_TO_MODE(pm); 1407 if (!PMC_IS_VIRTUAL_MODE(mode)) 1408 continue; /* not a process virtual PMC */ 1409 1410 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 1411 ("[pmc,%d] ri mismatch pmc(%d) ri(%d)", 1412 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 1413 1414 /* 1415 * Change desired state, and then stop if not stalled. 1416 * This two-step dance should avoid race conditions where 1417 * an interrupt re-enables the PMC after this code has 1418 * already checked the pm_stalled flag. 1419 */ 1420 CPU_CLR_ATOMIC(cpu, &pm->pm_cpustate); 1421 if (!CPU_ISSET(cpu, &pm->pm_stalled)) 1422 pcd->pcd_stop_pmc(cpu, adjri); 1423 1424 /* reduce this PMC's runcount */ 1425 atomic_subtract_rel_int(&pm->pm_runcount, 1); 1426 1427 /* 1428 * If this PMC is associated with this process, 1429 * save the reading. 1430 */ 1431 1432 if (pm->pm_state != PMC_STATE_DELETED && pp != NULL && 1433 pp->pp_pmcs[ri].pp_pmc != NULL) { 1434 KASSERT(pm == pp->pp_pmcs[ri].pp_pmc, 1435 ("[pmc,%d] pm %p != pp_pmcs[%d] %p", __LINE__, 1436 pm, ri, pp->pp_pmcs[ri].pp_pmc)); 1437 1438 KASSERT(pp->pp_refcnt > 0, 1439 ("[pmc,%d] pp refcnt = %d", __LINE__, 1440 pp->pp_refcnt)); 1441 1442 pcd->pcd_read_pmc(cpu, adjri, &newvalue); 1443 1444 if (mode == PMC_MODE_TS) { 1445 PMCDBG3(CSW,SWO,1,"cpu=%d ri=%d tmp=%jd (samp)", 1446 cpu, ri, PMC_PCPU_SAVED(cpu,ri) - newvalue); 1447 1448 /* 1449 * For sampling process-virtual PMCs, 1450 * newvalue is the number of events to be seen 1451 * until the next sampling interrupt. 1452 * We can just add the events left from this 1453 * invocation to the counter, then adjust 1454 * in case we overflow our range. 1455 * 1456 * (Recall that we reload the counter every 1457 * time we use it.) 1458 */ 1459 mtx_pool_lock_spin(pmc_mtxpool, pm); 1460 1461 pp->pp_pmcs[ri].pp_pmcval += newvalue; 1462 if (pp->pp_pmcs[ri].pp_pmcval > 1463 pm->pm_sc.pm_reloadcount) 1464 pp->pp_pmcs[ri].pp_pmcval -= 1465 pm->pm_sc.pm_reloadcount; 1466 KASSERT(pp->pp_pmcs[ri].pp_pmcval > 0 && 1467 pp->pp_pmcs[ri].pp_pmcval <= 1468 pm->pm_sc.pm_reloadcount, 1469 ("[pmc,%d] pp_pmcval outside of expected " 1470 "range cpu=%d ri=%d pp_pmcval=%jx " 1471 "pm_reloadcount=%jx", __LINE__, cpu, ri, 1472 pp->pp_pmcs[ri].pp_pmcval, 1473 pm->pm_sc.pm_reloadcount)); 1474 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1475 1476 } else { 1477 tmp = newvalue - PMC_PCPU_SAVED(cpu,ri); 1478 1479 PMCDBG3(CSW,SWO,1,"cpu=%d ri=%d tmp=%jd (count)", 1480 cpu, ri, tmp); 1481 1482 /* 1483 * For counting process-virtual PMCs, 1484 * we expect the count to be 1485 * increasing monotonically, modulo a 64 1486 * bit wraparound. 1487 */ 1488 KASSERT(tmp >= 0, 1489 ("[pmc,%d] negative increment cpu=%d " 1490 "ri=%d newvalue=%jx saved=%jx " 1491 "incr=%jx", __LINE__, cpu, ri, 1492 newvalue, PMC_PCPU_SAVED(cpu,ri), tmp)); 1493 1494 mtx_pool_lock_spin(pmc_mtxpool, pm); 1495 pm->pm_gv.pm_savedvalue += tmp; 1496 pp->pp_pmcs[ri].pp_pmcval += tmp; 1497 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1498 1499 if (pm->pm_flags & PMC_F_LOG_PROCCSW) 1500 pmclog_process_proccsw(pm, pp, tmp); 1501 } 1502 } 1503 1504 /* mark hardware as free */ 1505 pcd->pcd_config_pmc(cpu, adjri, NULL); 1506 } 1507 1508 /* 1509 * perform any other architecture/cpu dependent thread 1510 * switch out functions. 1511 */ 1512 1513 (void) (*md->pmd_switch_out)(pc, pp); 1514 1515 critical_exit(); 1516 } 1517 1518 /* 1519 * A mapping change for a process. 1520 */ 1521 1522 static void 1523 pmc_process_mmap(struct thread *td, struct pmckern_map_in *pkm) 1524 { 1525 int ri; 1526 pid_t pid; 1527 char *fullpath, *freepath; 1528 const struct pmc *pm; 1529 struct pmc_owner *po; 1530 const struct pmc_process *pp; 1531 1532 freepath = fullpath = NULL; 1533 pmc_getfilename((struct vnode *) pkm->pm_file, &fullpath, &freepath); 1534 1535 pid = td->td_proc->p_pid; 1536 1537 /* Inform owners of all system-wide sampling PMCs. */ 1538 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1539 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1540 pmclog_process_map_in(po, pid, pkm->pm_address, fullpath); 1541 1542 if ((pp = pmc_find_process_descriptor(td->td_proc, 0)) == NULL) 1543 goto done; 1544 1545 /* 1546 * Inform sampling PMC owners tracking this process. 1547 */ 1548 for (ri = 0; ri < md->pmd_npmc; ri++) 1549 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL && 1550 PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 1551 pmclog_process_map_in(pm->pm_owner, 1552 pid, pkm->pm_address, fullpath); 1553 1554 done: 1555 if (freepath) 1556 free(freepath, M_TEMP); 1557 } 1558 1559 1560 /* 1561 * Log an munmap request. 1562 */ 1563 1564 static void 1565 pmc_process_munmap(struct thread *td, struct pmckern_map_out *pkm) 1566 { 1567 int ri; 1568 pid_t pid; 1569 struct pmc_owner *po; 1570 const struct pmc *pm; 1571 const struct pmc_process *pp; 1572 1573 pid = td->td_proc->p_pid; 1574 1575 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1576 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1577 pmclog_process_map_out(po, pid, pkm->pm_address, 1578 pkm->pm_address + pkm->pm_size); 1579 1580 if ((pp = pmc_find_process_descriptor(td->td_proc, 0)) == NULL) 1581 return; 1582 1583 for (ri = 0; ri < md->pmd_npmc; ri++) 1584 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL && 1585 PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 1586 pmclog_process_map_out(pm->pm_owner, pid, 1587 pkm->pm_address, pkm->pm_address + pkm->pm_size); 1588 } 1589 1590 /* 1591 * Log mapping information about the kernel. 1592 */ 1593 1594 static void 1595 pmc_log_kernel_mappings(struct pmc *pm) 1596 { 1597 struct pmc_owner *po; 1598 struct pmckern_map_in *km, *kmbase; 1599 1600 sx_assert(&pmc_sx, SX_LOCKED); 1601 KASSERT(PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)), 1602 ("[pmc,%d] non-sampling PMC (%p) desires mapping information", 1603 __LINE__, (void *) pm)); 1604 1605 po = pm->pm_owner; 1606 1607 if (po->po_flags & PMC_PO_INITIAL_MAPPINGS_DONE) 1608 return; 1609 1610 /* 1611 * Log the current set of kernel modules. 1612 */ 1613 kmbase = linker_hwpmc_list_objects(); 1614 for (km = kmbase; km->pm_file != NULL; km++) { 1615 PMCDBG2(LOG,REG,1,"%s %p", (char *) km->pm_file, 1616 (void *) km->pm_address); 1617 pmclog_process_map_in(po, (pid_t) -1, km->pm_address, 1618 km->pm_file); 1619 } 1620 free(kmbase, M_LINKER); 1621 1622 po->po_flags |= PMC_PO_INITIAL_MAPPINGS_DONE; 1623 } 1624 1625 /* 1626 * Log the mappings for a single process. 1627 */ 1628 1629 static void 1630 pmc_log_process_mappings(struct pmc_owner *po, struct proc *p) 1631 { 1632 vm_map_t map; 1633 struct vnode *vp; 1634 struct vmspace *vm; 1635 vm_map_entry_t entry; 1636 vm_offset_t last_end; 1637 u_int last_timestamp; 1638 struct vnode *last_vp; 1639 vm_offset_t start_addr; 1640 vm_object_t obj, lobj, tobj; 1641 char *fullpath, *freepath; 1642 1643 last_vp = NULL; 1644 last_end = (vm_offset_t) 0; 1645 fullpath = freepath = NULL; 1646 1647 if ((vm = vmspace_acquire_ref(p)) == NULL) 1648 return; 1649 1650 map = &vm->vm_map; 1651 vm_map_lock_read(map); 1652 1653 for (entry = map->header.next; entry != &map->header; entry = entry->next) { 1654 1655 if (entry == NULL) { 1656 PMCDBG2(LOG,OPS,2, "hwpmc: vm_map entry unexpectedly " 1657 "NULL! pid=%d vm_map=%p\n", p->p_pid, map); 1658 break; 1659 } 1660 1661 /* 1662 * We only care about executable map entries. 1663 */ 1664 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) || 1665 !(entry->protection & VM_PROT_EXECUTE) || 1666 (entry->object.vm_object == NULL)) { 1667 continue; 1668 } 1669 1670 obj = entry->object.vm_object; 1671 VM_OBJECT_RLOCK(obj); 1672 1673 /* 1674 * Walk the backing_object list to find the base 1675 * (non-shadowed) vm_object. 1676 */ 1677 for (lobj = tobj = obj; tobj != NULL; tobj = tobj->backing_object) { 1678 if (tobj != obj) 1679 VM_OBJECT_RLOCK(tobj); 1680 if (lobj != obj) 1681 VM_OBJECT_RUNLOCK(lobj); 1682 lobj = tobj; 1683 } 1684 1685 /* 1686 * At this point lobj is the base vm_object and it is locked. 1687 */ 1688 if (lobj == NULL) { 1689 PMCDBG3(LOG,OPS,2, "hwpmc: lobj unexpectedly NULL! pid=%d " 1690 "vm_map=%p vm_obj=%p\n", p->p_pid, map, obj); 1691 VM_OBJECT_RUNLOCK(obj); 1692 continue; 1693 } 1694 1695 vp = vm_object_vnode(lobj); 1696 if (vp == NULL) { 1697 if (lobj != obj) 1698 VM_OBJECT_RUNLOCK(lobj); 1699 VM_OBJECT_RUNLOCK(obj); 1700 continue; 1701 } 1702 1703 /* 1704 * Skip contiguous regions that point to the same 1705 * vnode, so we don't emit redundant MAP-IN 1706 * directives. 1707 */ 1708 if (entry->start == last_end && vp == last_vp) { 1709 last_end = entry->end; 1710 if (lobj != obj) 1711 VM_OBJECT_RUNLOCK(lobj); 1712 VM_OBJECT_RUNLOCK(obj); 1713 continue; 1714 } 1715 1716 /* 1717 * We don't want to keep the proc's vm_map or this 1718 * vm_object locked while we walk the pathname, since 1719 * vn_fullpath() can sleep. However, if we drop the 1720 * lock, it's possible for concurrent activity to 1721 * modify the vm_map list. To protect against this, 1722 * we save the vm_map timestamp before we release the 1723 * lock, and check it after we reacquire the lock 1724 * below. 1725 */ 1726 start_addr = entry->start; 1727 last_end = entry->end; 1728 last_timestamp = map->timestamp; 1729 vm_map_unlock_read(map); 1730 1731 vref(vp); 1732 if (lobj != obj) 1733 VM_OBJECT_RUNLOCK(lobj); 1734 1735 VM_OBJECT_RUNLOCK(obj); 1736 1737 freepath = NULL; 1738 pmc_getfilename(vp, &fullpath, &freepath); 1739 last_vp = vp; 1740 1741 vrele(vp); 1742 1743 vp = NULL; 1744 pmclog_process_map_in(po, p->p_pid, start_addr, fullpath); 1745 if (freepath) 1746 free(freepath, M_TEMP); 1747 1748 vm_map_lock_read(map); 1749 1750 /* 1751 * If our saved timestamp doesn't match, this means 1752 * that the vm_map was modified out from under us and 1753 * we can't trust our current "entry" pointer. Do a 1754 * new lookup for this entry. If there is no entry 1755 * for this address range, vm_map_lookup_entry() will 1756 * return the previous one, so we always want to go to 1757 * entry->next on the next loop iteration. 1758 * 1759 * There is an edge condition here that can occur if 1760 * there is no entry at or before this address. In 1761 * this situation, vm_map_lookup_entry returns 1762 * &map->header, which would cause our loop to abort 1763 * without processing the rest of the map. However, 1764 * in practice this will never happen for process 1765 * vm_map. This is because the executable's text 1766 * segment is the first mapping in the proc's address 1767 * space, and this mapping is never removed until the 1768 * process exits, so there will always be a non-header 1769 * entry at or before the requested address for 1770 * vm_map_lookup_entry to return. 1771 */ 1772 if (map->timestamp != last_timestamp) 1773 vm_map_lookup_entry(map, last_end - 1, &entry); 1774 } 1775 1776 vm_map_unlock_read(map); 1777 vmspace_free(vm); 1778 return; 1779 } 1780 1781 /* 1782 * Log mappings for all processes in the system. 1783 */ 1784 1785 static void 1786 pmc_log_all_process_mappings(struct pmc_owner *po) 1787 { 1788 struct proc *p, *top; 1789 1790 sx_assert(&pmc_sx, SX_XLOCKED); 1791 1792 if ((p = pfind(1)) == NULL) 1793 panic("[pmc,%d] Cannot find init", __LINE__); 1794 1795 PROC_UNLOCK(p); 1796 1797 sx_slock(&proctree_lock); 1798 1799 top = p; 1800 1801 for (;;) { 1802 pmc_log_process_mappings(po, p); 1803 if (!LIST_EMPTY(&p->p_children)) 1804 p = LIST_FIRST(&p->p_children); 1805 else for (;;) { 1806 if (p == top) 1807 goto done; 1808 if (LIST_NEXT(p, p_sibling)) { 1809 p = LIST_NEXT(p, p_sibling); 1810 break; 1811 } 1812 p = p->p_pptr; 1813 } 1814 } 1815 done: 1816 sx_sunlock(&proctree_lock); 1817 } 1818 1819 /* 1820 * The 'hook' invoked from the kernel proper 1821 */ 1822 1823 1824 #ifdef HWPMC_DEBUG 1825 const char *pmc_hooknames[] = { 1826 /* these strings correspond to PMC_FN_* in <sys/pmckern.h> */ 1827 "", 1828 "EXEC", 1829 "CSW-IN", 1830 "CSW-OUT", 1831 "SAMPLE", 1832 "UNUSED1", 1833 "UNUSED2", 1834 "MMAP", 1835 "MUNMAP", 1836 "CALLCHAIN-NMI", 1837 "CALLCHAIN-SOFT", 1838 "SOFTSAMPLING" 1839 }; 1840 #endif 1841 1842 static int 1843 pmc_hook_handler(struct thread *td, int function, void *arg) 1844 { 1845 1846 PMCDBG4(MOD,PMH,1, "hook td=%p func=%d \"%s\" arg=%p", td, function, 1847 pmc_hooknames[function], arg); 1848 1849 switch (function) 1850 { 1851 1852 /* 1853 * Process exec() 1854 */ 1855 1856 case PMC_FN_PROCESS_EXEC: 1857 { 1858 char *fullpath, *freepath; 1859 unsigned int ri; 1860 int is_using_hwpmcs; 1861 struct pmc *pm; 1862 struct proc *p; 1863 struct pmc_owner *po; 1864 struct pmc_process *pp; 1865 struct pmckern_procexec *pk; 1866 1867 sx_assert(&pmc_sx, SX_XLOCKED); 1868 1869 p = td->td_proc; 1870 pmc_getfilename(p->p_textvp, &fullpath, &freepath); 1871 1872 pk = (struct pmckern_procexec *) arg; 1873 1874 /* Inform owners of SS mode PMCs of the exec event. */ 1875 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1876 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1877 pmclog_process_procexec(po, PMC_ID_INVALID, 1878 p->p_pid, pk->pm_entryaddr, fullpath); 1879 1880 PROC_LOCK(p); 1881 is_using_hwpmcs = p->p_flag & P_HWPMC; 1882 PROC_UNLOCK(p); 1883 1884 if (!is_using_hwpmcs) { 1885 if (freepath) 1886 free(freepath, M_TEMP); 1887 break; 1888 } 1889 1890 /* 1891 * PMCs are not inherited across an exec(): remove any 1892 * PMCs that this process is the owner of. 1893 */ 1894 1895 if ((po = pmc_find_owner_descriptor(p)) != NULL) { 1896 pmc_remove_owner(po); 1897 pmc_destroy_owner_descriptor(po); 1898 } 1899 1900 /* 1901 * If the process being exec'ed is not the target of any 1902 * PMC, we are done. 1903 */ 1904 if ((pp = pmc_find_process_descriptor(p, 0)) == NULL) { 1905 if (freepath) 1906 free(freepath, M_TEMP); 1907 break; 1908 } 1909 1910 /* 1911 * Log the exec event to all monitoring owners. Skip 1912 * owners who have already received the event because 1913 * they had system sampling PMCs active. 1914 */ 1915 for (ri = 0; ri < md->pmd_npmc; ri++) 1916 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) { 1917 po = pm->pm_owner; 1918 if (po->po_sscount == 0 && 1919 po->po_flags & PMC_PO_OWNS_LOGFILE) 1920 pmclog_process_procexec(po, pm->pm_id, 1921 p->p_pid, pk->pm_entryaddr, 1922 fullpath); 1923 } 1924 1925 if (freepath) 1926 free(freepath, M_TEMP); 1927 1928 1929 PMCDBG4(PRC,EXC,1, "exec proc=%p (%d, %s) cred-changed=%d", 1930 p, p->p_pid, p->p_comm, pk->pm_credentialschanged); 1931 1932 if (pk->pm_credentialschanged == 0) /* no change */ 1933 break; 1934 1935 /* 1936 * If the newly exec()'ed process has a different credential 1937 * than before, allow it to be the target of a PMC only if 1938 * the PMC's owner has sufficient privilege. 1939 */ 1940 1941 for (ri = 0; ri < md->pmd_npmc; ri++) 1942 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) 1943 if (pmc_can_attach(pm, td->td_proc) != 0) 1944 pmc_detach_one_process(td->td_proc, 1945 pm, PMC_FLAG_NONE); 1946 1947 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= (int) md->pmd_npmc, 1948 ("[pmc,%d] Illegal ref count %d on pp %p", __LINE__, 1949 pp->pp_refcnt, pp)); 1950 1951 /* 1952 * If this process is no longer the target of any 1953 * PMCs, we can remove the process entry and free 1954 * up space. 1955 */ 1956 1957 if (pp->pp_refcnt == 0) { 1958 pmc_remove_process_descriptor(pp); 1959 free(pp, M_PMC); 1960 break; 1961 } 1962 1963 } 1964 break; 1965 1966 case PMC_FN_CSW_IN: 1967 pmc_process_csw_in(td); 1968 break; 1969 1970 case PMC_FN_CSW_OUT: 1971 pmc_process_csw_out(td); 1972 break; 1973 1974 /* 1975 * Process accumulated PC samples. 1976 * 1977 * This function is expected to be called by hardclock() for 1978 * each CPU that has accumulated PC samples. 1979 * 1980 * This function is to be executed on the CPU whose samples 1981 * are being processed. 1982 */ 1983 case PMC_FN_DO_SAMPLES: 1984 1985 /* 1986 * Clear the cpu specific bit in the CPU mask before 1987 * do the rest of the processing. If the NMI handler 1988 * gets invoked after the "atomic_clear_int()" call 1989 * below but before "pmc_process_samples()" gets 1990 * around to processing the interrupt, then we will 1991 * come back here at the next hardclock() tick (and 1992 * may find nothing to do if "pmc_process_samples()" 1993 * had already processed the interrupt). We don't 1994 * lose the interrupt sample. 1995 */ 1996 CPU_CLR_ATOMIC(PCPU_GET(cpuid), &pmc_cpumask); 1997 pmc_process_samples(PCPU_GET(cpuid), PMC_HR); 1998 pmc_process_samples(PCPU_GET(cpuid), PMC_SR); 1999 break; 2000 2001 case PMC_FN_MMAP: 2002 sx_assert(&pmc_sx, SX_LOCKED); 2003 pmc_process_mmap(td, (struct pmckern_map_in *) arg); 2004 break; 2005 2006 case PMC_FN_MUNMAP: 2007 sx_assert(&pmc_sx, SX_LOCKED); 2008 pmc_process_munmap(td, (struct pmckern_map_out *) arg); 2009 break; 2010 2011 case PMC_FN_USER_CALLCHAIN: 2012 /* 2013 * Record a call chain. 2014 */ 2015 KASSERT(td == curthread, ("[pmc,%d] td != curthread", 2016 __LINE__)); 2017 2018 pmc_capture_user_callchain(PCPU_GET(cpuid), PMC_HR, 2019 (struct trapframe *) arg); 2020 td->td_pflags &= ~TDP_CALLCHAIN; 2021 break; 2022 2023 case PMC_FN_USER_CALLCHAIN_SOFT: 2024 /* 2025 * Record a call chain. 2026 */ 2027 KASSERT(td == curthread, ("[pmc,%d] td != curthread", 2028 __LINE__)); 2029 pmc_capture_user_callchain(PCPU_GET(cpuid), PMC_SR, 2030 (struct trapframe *) arg); 2031 td->td_pflags &= ~TDP_CALLCHAIN; 2032 break; 2033 2034 case PMC_FN_SOFT_SAMPLING: 2035 /* 2036 * Call soft PMC sampling intr. 2037 */ 2038 pmc_soft_intr((struct pmckern_soft *) arg); 2039 break; 2040 2041 default: 2042 #ifdef HWPMC_DEBUG 2043 KASSERT(0, ("[pmc,%d] unknown hook %d\n", __LINE__, function)); 2044 #endif 2045 break; 2046 2047 } 2048 2049 return 0; 2050 } 2051 2052 /* 2053 * allocate a 'struct pmc_owner' descriptor in the owner hash table. 2054 */ 2055 2056 static struct pmc_owner * 2057 pmc_allocate_owner_descriptor(struct proc *p) 2058 { 2059 uint32_t hindex; 2060 struct pmc_owner *po; 2061 struct pmc_ownerhash *poh; 2062 2063 hindex = PMC_HASH_PTR(p, pmc_ownerhashmask); 2064 poh = &pmc_ownerhash[hindex]; 2065 2066 /* allocate space for N pointers and one descriptor struct */ 2067 po = malloc(sizeof(struct pmc_owner), M_PMC, M_WAITOK|M_ZERO); 2068 po->po_owner = p; 2069 LIST_INSERT_HEAD(poh, po, po_next); /* insert into hash table */ 2070 2071 TAILQ_INIT(&po->po_logbuffers); 2072 mtx_init(&po->po_mtx, "pmc-owner-mtx", "pmc-per-proc", MTX_SPIN); 2073 2074 PMCDBG4(OWN,ALL,1, "allocate-owner proc=%p (%d, %s) pmc-owner=%p", 2075 p, p->p_pid, p->p_comm, po); 2076 2077 return po; 2078 } 2079 2080 static void 2081 pmc_destroy_owner_descriptor(struct pmc_owner *po) 2082 { 2083 2084 PMCDBG4(OWN,REL,1, "destroy-owner po=%p proc=%p (%d, %s)", 2085 po, po->po_owner, po->po_owner->p_pid, po->po_owner->p_comm); 2086 2087 mtx_destroy(&po->po_mtx); 2088 free(po, M_PMC); 2089 } 2090 2091 /* 2092 * find the descriptor corresponding to process 'p', adding or removing it 2093 * as specified by 'mode'. 2094 */ 2095 2096 static struct pmc_process * 2097 pmc_find_process_descriptor(struct proc *p, uint32_t mode) 2098 { 2099 uint32_t hindex; 2100 struct pmc_process *pp, *ppnew; 2101 struct pmc_processhash *pph; 2102 2103 hindex = PMC_HASH_PTR(p, pmc_processhashmask); 2104 pph = &pmc_processhash[hindex]; 2105 2106 ppnew = NULL; 2107 2108 /* 2109 * Pre-allocate memory in the FIND_ALLOCATE case since we 2110 * cannot call malloc(9) once we hold a spin lock. 2111 */ 2112 if (mode & PMC_FLAG_ALLOCATE) 2113 ppnew = malloc(sizeof(struct pmc_process) + md->pmd_npmc * 2114 sizeof(struct pmc_targetstate), M_PMC, M_WAITOK|M_ZERO); 2115 2116 mtx_lock_spin(&pmc_processhash_mtx); 2117 LIST_FOREACH(pp, pph, pp_next) 2118 if (pp->pp_proc == p) 2119 break; 2120 2121 if ((mode & PMC_FLAG_REMOVE) && pp != NULL) 2122 LIST_REMOVE(pp, pp_next); 2123 2124 if ((mode & PMC_FLAG_ALLOCATE) && pp == NULL && 2125 ppnew != NULL) { 2126 ppnew->pp_proc = p; 2127 LIST_INSERT_HEAD(pph, ppnew, pp_next); 2128 pp = ppnew; 2129 ppnew = NULL; 2130 } 2131 mtx_unlock_spin(&pmc_processhash_mtx); 2132 2133 if (pp != NULL && ppnew != NULL) 2134 free(ppnew, M_PMC); 2135 2136 return pp; 2137 } 2138 2139 /* 2140 * remove a process descriptor from the process hash table. 2141 */ 2142 2143 static void 2144 pmc_remove_process_descriptor(struct pmc_process *pp) 2145 { 2146 KASSERT(pp->pp_refcnt == 0, 2147 ("[pmc,%d] Removing process descriptor %p with count %d", 2148 __LINE__, pp, pp->pp_refcnt)); 2149 2150 mtx_lock_spin(&pmc_processhash_mtx); 2151 LIST_REMOVE(pp, pp_next); 2152 mtx_unlock_spin(&pmc_processhash_mtx); 2153 } 2154 2155 2156 /* 2157 * find an owner descriptor corresponding to proc 'p' 2158 */ 2159 2160 static struct pmc_owner * 2161 pmc_find_owner_descriptor(struct proc *p) 2162 { 2163 uint32_t hindex; 2164 struct pmc_owner *po; 2165 struct pmc_ownerhash *poh; 2166 2167 hindex = PMC_HASH_PTR(p, pmc_ownerhashmask); 2168 poh = &pmc_ownerhash[hindex]; 2169 2170 po = NULL; 2171 LIST_FOREACH(po, poh, po_next) 2172 if (po->po_owner == p) 2173 break; 2174 2175 PMCDBG5(OWN,FND,1, "find-owner proc=%p (%d, %s) hindex=0x%x -> " 2176 "pmc-owner=%p", p, p->p_pid, p->p_comm, hindex, po); 2177 2178 return po; 2179 } 2180 2181 /* 2182 * pmc_allocate_pmc_descriptor 2183 * 2184 * Allocate a pmc descriptor and initialize its 2185 * fields. 2186 */ 2187 2188 static struct pmc * 2189 pmc_allocate_pmc_descriptor(void) 2190 { 2191 struct pmc *pmc; 2192 2193 pmc = malloc(sizeof(struct pmc), M_PMC, M_WAITOK|M_ZERO); 2194 2195 PMCDBG1(PMC,ALL,1, "allocate-pmc -> pmc=%p", pmc); 2196 2197 return pmc; 2198 } 2199 2200 /* 2201 * Destroy a pmc descriptor. 2202 */ 2203 2204 static void 2205 pmc_destroy_pmc_descriptor(struct pmc *pm) 2206 { 2207 2208 KASSERT(pm->pm_state == PMC_STATE_DELETED || 2209 pm->pm_state == PMC_STATE_FREE, 2210 ("[pmc,%d] destroying non-deleted PMC", __LINE__)); 2211 KASSERT(LIST_EMPTY(&pm->pm_targets), 2212 ("[pmc,%d] destroying pmc with targets", __LINE__)); 2213 KASSERT(pm->pm_owner == NULL, 2214 ("[pmc,%d] destroying pmc attached to an owner", __LINE__)); 2215 KASSERT(pm->pm_runcount == 0, 2216 ("[pmc,%d] pmc has non-zero run count %d", __LINE__, 2217 pm->pm_runcount)); 2218 2219 free(pm, M_PMC); 2220 } 2221 2222 static void 2223 pmc_wait_for_pmc_idle(struct pmc *pm) 2224 { 2225 #ifdef HWPMC_DEBUG 2226 volatile int maxloop; 2227 2228 maxloop = 100 * pmc_cpu_max(); 2229 #endif 2230 /* 2231 * Loop (with a forced context switch) till the PMC's runcount 2232 * comes down to zero. 2233 */ 2234 while (atomic_load_acq_32(&pm->pm_runcount) > 0) { 2235 #ifdef HWPMC_DEBUG 2236 maxloop--; 2237 KASSERT(maxloop > 0, 2238 ("[pmc,%d] (ri%d, rc%d) waiting too long for " 2239 "pmc to be free", __LINE__, 2240 PMC_TO_ROWINDEX(pm), pm->pm_runcount)); 2241 #endif 2242 pmc_force_context_switch(); 2243 } 2244 } 2245 2246 /* 2247 * This function does the following things: 2248 * 2249 * - detaches the PMC from hardware 2250 * - unlinks all target threads that were attached to it 2251 * - removes the PMC from its owner's list 2252 * - destroys the PMC private mutex 2253 * 2254 * Once this function completes, the given pmc pointer can be freed by 2255 * calling pmc_destroy_pmc_descriptor(). 2256 */ 2257 2258 static void 2259 pmc_release_pmc_descriptor(struct pmc *pm) 2260 { 2261 enum pmc_mode mode; 2262 struct pmc_hw *phw; 2263 u_int adjri, ri, cpu; 2264 struct pmc_owner *po; 2265 struct pmc_binding pb; 2266 struct pmc_process *pp; 2267 struct pmc_classdep *pcd; 2268 struct pmc_target *ptgt, *tmp; 2269 2270 sx_assert(&pmc_sx, SX_XLOCKED); 2271 2272 KASSERT(pm, ("[pmc,%d] null pmc", __LINE__)); 2273 2274 ri = PMC_TO_ROWINDEX(pm); 2275 pcd = pmc_ri_to_classdep(md, ri, &adjri); 2276 mode = PMC_TO_MODE(pm); 2277 2278 PMCDBG3(PMC,REL,1, "release-pmc pmc=%p ri=%d mode=%d", pm, ri, 2279 mode); 2280 2281 /* 2282 * First, we take the PMC off hardware. 2283 */ 2284 cpu = 0; 2285 if (PMC_IS_SYSTEM_MODE(mode)) { 2286 2287 /* 2288 * A system mode PMC runs on a specific CPU. Switch 2289 * to this CPU and turn hardware off. 2290 */ 2291 pmc_save_cpu_binding(&pb); 2292 2293 cpu = PMC_TO_CPU(pm); 2294 2295 pmc_select_cpu(cpu); 2296 2297 /* switch off non-stalled CPUs */ 2298 CPU_CLR_ATOMIC(cpu, &pm->pm_cpustate); 2299 if (pm->pm_state == PMC_STATE_RUNNING && 2300 !CPU_ISSET(cpu, &pm->pm_stalled)) { 2301 2302 phw = pmc_pcpu[cpu]->pc_hwpmcs[ri]; 2303 2304 KASSERT(phw->phw_pmc == pm, 2305 ("[pmc, %d] pmc ptr ri(%d) hw(%p) pm(%p)", 2306 __LINE__, ri, phw->phw_pmc, pm)); 2307 PMCDBG2(PMC,REL,2, "stopping cpu=%d ri=%d", cpu, ri); 2308 2309 critical_enter(); 2310 pcd->pcd_stop_pmc(cpu, adjri); 2311 critical_exit(); 2312 } 2313 2314 PMCDBG2(PMC,REL,2, "decfg cpu=%d ri=%d", cpu, ri); 2315 2316 critical_enter(); 2317 pcd->pcd_config_pmc(cpu, adjri, NULL); 2318 critical_exit(); 2319 2320 /* adjust the global and process count of SS mode PMCs */ 2321 if (mode == PMC_MODE_SS && pm->pm_state == PMC_STATE_RUNNING) { 2322 po = pm->pm_owner; 2323 po->po_sscount--; 2324 if (po->po_sscount == 0) { 2325 atomic_subtract_rel_int(&pmc_ss_count, 1); 2326 LIST_REMOVE(po, po_ssnext); 2327 } 2328 } 2329 2330 pm->pm_state = PMC_STATE_DELETED; 2331 2332 pmc_restore_cpu_binding(&pb); 2333 2334 /* 2335 * We could have references to this PMC structure in 2336 * the per-cpu sample queues. Wait for the queue to 2337 * drain. 2338 */ 2339 pmc_wait_for_pmc_idle(pm); 2340 2341 } else if (PMC_IS_VIRTUAL_MODE(mode)) { 2342 2343 /* 2344 * A virtual PMC could be running on multiple CPUs at 2345 * a given instant. 2346 * 2347 * By marking its state as DELETED, we ensure that 2348 * this PMC is never further scheduled on hardware. 2349 * 2350 * Then we wait till all CPUs are done with this PMC. 2351 */ 2352 pm->pm_state = PMC_STATE_DELETED; 2353 2354 2355 /* Wait for the PMCs runcount to come to zero. */ 2356 pmc_wait_for_pmc_idle(pm); 2357 2358 /* 2359 * At this point the PMC is off all CPUs and cannot be 2360 * freshly scheduled onto a CPU. It is now safe to 2361 * unlink all targets from this PMC. If a 2362 * process-record's refcount falls to zero, we remove 2363 * it from the hash table. The module-wide SX lock 2364 * protects us from races. 2365 */ 2366 LIST_FOREACH_SAFE(ptgt, &pm->pm_targets, pt_next, tmp) { 2367 pp = ptgt->pt_process; 2368 pmc_unlink_target_process(pm, pp); /* frees 'ptgt' */ 2369 2370 PMCDBG1(PMC,REL,3, "pp->refcnt=%d", pp->pp_refcnt); 2371 2372 /* 2373 * If the target process record shows that no 2374 * PMCs are attached to it, reclaim its space. 2375 */ 2376 2377 if (pp->pp_refcnt == 0) { 2378 pmc_remove_process_descriptor(pp); 2379 free(pp, M_PMC); 2380 } 2381 } 2382 2383 cpu = curthread->td_oncpu; /* setup cpu for pmd_release() */ 2384 2385 } 2386 2387 /* 2388 * Release any MD resources 2389 */ 2390 (void) pcd->pcd_release_pmc(cpu, adjri, pm); 2391 2392 /* 2393 * Update row disposition 2394 */ 2395 2396 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) 2397 PMC_UNMARK_ROW_STANDALONE(ri); 2398 else 2399 PMC_UNMARK_ROW_THREAD(ri); 2400 2401 /* unlink from the owner's list */ 2402 if (pm->pm_owner) { 2403 LIST_REMOVE(pm, pm_next); 2404 pm->pm_owner = NULL; 2405 } 2406 } 2407 2408 /* 2409 * Register an owner and a pmc. 2410 */ 2411 2412 static int 2413 pmc_register_owner(struct proc *p, struct pmc *pmc) 2414 { 2415 struct pmc_owner *po; 2416 2417 sx_assert(&pmc_sx, SX_XLOCKED); 2418 2419 if ((po = pmc_find_owner_descriptor(p)) == NULL) 2420 if ((po = pmc_allocate_owner_descriptor(p)) == NULL) 2421 return ENOMEM; 2422 2423 KASSERT(pmc->pm_owner == NULL, 2424 ("[pmc,%d] attempting to own an initialized PMC", __LINE__)); 2425 pmc->pm_owner = po; 2426 2427 LIST_INSERT_HEAD(&po->po_pmcs, pmc, pm_next); 2428 2429 PROC_LOCK(p); 2430 p->p_flag |= P_HWPMC; 2431 PROC_UNLOCK(p); 2432 2433 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 2434 pmclog_process_pmcallocate(pmc); 2435 2436 PMCDBG2(PMC,REG,1, "register-owner pmc-owner=%p pmc=%p", 2437 po, pmc); 2438 2439 return 0; 2440 } 2441 2442 /* 2443 * Return the current row disposition: 2444 * == 0 => FREE 2445 * > 0 => PROCESS MODE 2446 * < 0 => SYSTEM MODE 2447 */ 2448 2449 int 2450 pmc_getrowdisp(int ri) 2451 { 2452 return pmc_pmcdisp[ri]; 2453 } 2454 2455 /* 2456 * Check if a PMC at row index 'ri' can be allocated to the current 2457 * process. 2458 * 2459 * Allocation can fail if: 2460 * - the current process is already being profiled by a PMC at index 'ri', 2461 * attached to it via OP_PMCATTACH. 2462 * - the current process has already allocated a PMC at index 'ri' 2463 * via OP_ALLOCATE. 2464 */ 2465 2466 static int 2467 pmc_can_allocate_rowindex(struct proc *p, unsigned int ri, int cpu) 2468 { 2469 enum pmc_mode mode; 2470 struct pmc *pm; 2471 struct pmc_owner *po; 2472 struct pmc_process *pp; 2473 2474 PMCDBG5(PMC,ALR,1, "can-allocate-rowindex proc=%p (%d, %s) ri=%d " 2475 "cpu=%d", p, p->p_pid, p->p_comm, ri, cpu); 2476 2477 /* 2478 * We shouldn't have already allocated a process-mode PMC at 2479 * row index 'ri'. 2480 * 2481 * We shouldn't have allocated a system-wide PMC on the same 2482 * CPU and same RI. 2483 */ 2484 if ((po = pmc_find_owner_descriptor(p)) != NULL) 2485 LIST_FOREACH(pm, &po->po_pmcs, pm_next) { 2486 if (PMC_TO_ROWINDEX(pm) == ri) { 2487 mode = PMC_TO_MODE(pm); 2488 if (PMC_IS_VIRTUAL_MODE(mode)) 2489 return EEXIST; 2490 if (PMC_IS_SYSTEM_MODE(mode) && 2491 (int) PMC_TO_CPU(pm) == cpu) 2492 return EEXIST; 2493 } 2494 } 2495 2496 /* 2497 * We also shouldn't be the target of any PMC at this index 2498 * since otherwise a PMC_ATTACH to ourselves will fail. 2499 */ 2500 if ((pp = pmc_find_process_descriptor(p, 0)) != NULL) 2501 if (pp->pp_pmcs[ri].pp_pmc) 2502 return EEXIST; 2503 2504 PMCDBG4(PMC,ALR,2, "can-allocate-rowindex proc=%p (%d, %s) ri=%d ok", 2505 p, p->p_pid, p->p_comm, ri); 2506 2507 return 0; 2508 } 2509 2510 /* 2511 * Check if a given PMC at row index 'ri' can be currently used in 2512 * mode 'mode'. 2513 */ 2514 2515 static int 2516 pmc_can_allocate_row(int ri, enum pmc_mode mode) 2517 { 2518 enum pmc_disp disp; 2519 2520 sx_assert(&pmc_sx, SX_XLOCKED); 2521 2522 PMCDBG2(PMC,ALR,1, "can-allocate-row ri=%d mode=%d", ri, mode); 2523 2524 if (PMC_IS_SYSTEM_MODE(mode)) 2525 disp = PMC_DISP_STANDALONE; 2526 else 2527 disp = PMC_DISP_THREAD; 2528 2529 /* 2530 * check disposition for PMC row 'ri': 2531 * 2532 * Expected disposition Row-disposition Result 2533 * 2534 * STANDALONE STANDALONE or FREE proceed 2535 * STANDALONE THREAD fail 2536 * THREAD THREAD or FREE proceed 2537 * THREAD STANDALONE fail 2538 */ 2539 2540 if (!PMC_ROW_DISP_IS_FREE(ri) && 2541 !(disp == PMC_DISP_THREAD && PMC_ROW_DISP_IS_THREAD(ri)) && 2542 !(disp == PMC_DISP_STANDALONE && PMC_ROW_DISP_IS_STANDALONE(ri))) 2543 return EBUSY; 2544 2545 /* 2546 * All OK 2547 */ 2548 2549 PMCDBG2(PMC,ALR,2, "can-allocate-row ri=%d mode=%d ok", ri, mode); 2550 2551 return 0; 2552 2553 } 2554 2555 /* 2556 * Find a PMC descriptor with user handle 'pmcid' for thread 'td'. 2557 */ 2558 2559 static struct pmc * 2560 pmc_find_pmc_descriptor_in_process(struct pmc_owner *po, pmc_id_t pmcid) 2561 { 2562 struct pmc *pm; 2563 2564 KASSERT(PMC_ID_TO_ROWINDEX(pmcid) < md->pmd_npmc, 2565 ("[pmc,%d] Illegal pmc index %d (max %d)", __LINE__, 2566 PMC_ID_TO_ROWINDEX(pmcid), md->pmd_npmc)); 2567 2568 LIST_FOREACH(pm, &po->po_pmcs, pm_next) 2569 if (pm->pm_id == pmcid) 2570 return pm; 2571 2572 return NULL; 2573 } 2574 2575 static int 2576 pmc_find_pmc(pmc_id_t pmcid, struct pmc **pmc) 2577 { 2578 2579 struct pmc *pm, *opm; 2580 struct pmc_owner *po; 2581 struct pmc_process *pp; 2582 2583 PMCDBG1(PMC,FND,1, "find-pmc id=%d", pmcid); 2584 if (PMC_ID_TO_ROWINDEX(pmcid) >= md->pmd_npmc) 2585 return (EINVAL); 2586 2587 if ((po = pmc_find_owner_descriptor(curthread->td_proc)) == NULL) { 2588 /* 2589 * In case of PMC_F_DESCENDANTS child processes we will not find 2590 * the current process in the owners hash list. Find the owner 2591 * process first and from there lookup the po. 2592 */ 2593 if ((pp = pmc_find_process_descriptor(curthread->td_proc, 2594 PMC_FLAG_NONE)) == NULL) { 2595 return ESRCH; 2596 } else { 2597 opm = pp->pp_pmcs[PMC_ID_TO_ROWINDEX(pmcid)].pp_pmc; 2598 if (opm == NULL) 2599 return ESRCH; 2600 if ((opm->pm_flags & (PMC_F_ATTACHED_TO_OWNER| 2601 PMC_F_DESCENDANTS)) != (PMC_F_ATTACHED_TO_OWNER| 2602 PMC_F_DESCENDANTS)) 2603 return ESRCH; 2604 po = opm->pm_owner; 2605 } 2606 } 2607 2608 if ((pm = pmc_find_pmc_descriptor_in_process(po, pmcid)) == NULL) 2609 return EINVAL; 2610 2611 PMCDBG2(PMC,FND,2, "find-pmc id=%d -> pmc=%p", pmcid, pm); 2612 2613 *pmc = pm; 2614 return 0; 2615 } 2616 2617 /* 2618 * Start a PMC. 2619 */ 2620 2621 static int 2622 pmc_start(struct pmc *pm) 2623 { 2624 enum pmc_mode mode; 2625 struct pmc_owner *po; 2626 struct pmc_binding pb; 2627 struct pmc_classdep *pcd; 2628 int adjri, error, cpu, ri; 2629 2630 KASSERT(pm != NULL, 2631 ("[pmc,%d] null pm", __LINE__)); 2632 2633 mode = PMC_TO_MODE(pm); 2634 ri = PMC_TO_ROWINDEX(pm); 2635 pcd = pmc_ri_to_classdep(md, ri, &adjri); 2636 2637 error = 0; 2638 2639 PMCDBG3(PMC,OPS,1, "start pmc=%p mode=%d ri=%d", pm, mode, ri); 2640 2641 po = pm->pm_owner; 2642 2643 /* 2644 * Disallow PMCSTART if a logfile is required but has not been 2645 * configured yet. 2646 */ 2647 if ((pm->pm_flags & PMC_F_NEEDS_LOGFILE) && 2648 (po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) 2649 return (EDOOFUS); /* programming error */ 2650 2651 /* 2652 * If this is a sampling mode PMC, log mapping information for 2653 * the kernel modules that are currently loaded. 2654 */ 2655 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 2656 pmc_log_kernel_mappings(pm); 2657 2658 if (PMC_IS_VIRTUAL_MODE(mode)) { 2659 2660 /* 2661 * If a PMCATTACH has never been done on this PMC, 2662 * attach it to its owner process. 2663 */ 2664 2665 if (LIST_EMPTY(&pm->pm_targets)) 2666 error = (pm->pm_flags & PMC_F_ATTACH_DONE) ? ESRCH : 2667 pmc_attach_process(po->po_owner, pm); 2668 2669 /* 2670 * If the PMC is attached to its owner, then force a context 2671 * switch to ensure that the MD state gets set correctly. 2672 */ 2673 2674 if (error == 0) { 2675 pm->pm_state = PMC_STATE_RUNNING; 2676 if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) 2677 pmc_force_context_switch(); 2678 } 2679 2680 return (error); 2681 } 2682 2683 2684 /* 2685 * A system-wide PMC. 2686 * 2687 * Add the owner to the global list if this is a system-wide 2688 * sampling PMC. 2689 */ 2690 2691 if (mode == PMC_MODE_SS) { 2692 if (po->po_sscount == 0) { 2693 LIST_INSERT_HEAD(&pmc_ss_owners, po, po_ssnext); 2694 atomic_add_rel_int(&pmc_ss_count, 1); 2695 PMCDBG1(PMC,OPS,1, "po=%p in global list", po); 2696 } 2697 po->po_sscount++; 2698 2699 /* 2700 * Log mapping information for all existing processes in the 2701 * system. Subsequent mappings are logged as they happen; 2702 * see pmc_process_mmap(). 2703 */ 2704 if (po->po_logprocmaps == 0) { 2705 pmc_log_all_process_mappings(po); 2706 po->po_logprocmaps = 1; 2707 } 2708 } 2709 2710 /* 2711 * Move to the CPU associated with this 2712 * PMC, and start the hardware. 2713 */ 2714 2715 pmc_save_cpu_binding(&pb); 2716 2717 cpu = PMC_TO_CPU(pm); 2718 2719 if (!pmc_cpu_is_active(cpu)) 2720 return (ENXIO); 2721 2722 pmc_select_cpu(cpu); 2723 2724 /* 2725 * global PMCs are configured at allocation time 2726 * so write out the initial value and start the PMC. 2727 */ 2728 2729 pm->pm_state = PMC_STATE_RUNNING; 2730 2731 critical_enter(); 2732 if ((error = pcd->pcd_write_pmc(cpu, adjri, 2733 PMC_IS_SAMPLING_MODE(mode) ? 2734 pm->pm_sc.pm_reloadcount : 2735 pm->pm_sc.pm_initial)) == 0) { 2736 /* If a sampling mode PMC, reset stalled state. */ 2737 if (PMC_IS_SAMPLING_MODE(mode)) 2738 CPU_CLR_ATOMIC(cpu, &pm->pm_stalled); 2739 2740 /* Indicate that we desire this to run. Start it. */ 2741 CPU_SET_ATOMIC(cpu, &pm->pm_cpustate); 2742 error = pcd->pcd_start_pmc(cpu, adjri); 2743 } 2744 critical_exit(); 2745 2746 pmc_restore_cpu_binding(&pb); 2747 2748 return (error); 2749 } 2750 2751 /* 2752 * Stop a PMC. 2753 */ 2754 2755 static int 2756 pmc_stop(struct pmc *pm) 2757 { 2758 struct pmc_owner *po; 2759 struct pmc_binding pb; 2760 struct pmc_classdep *pcd; 2761 int adjri, cpu, error, ri; 2762 2763 KASSERT(pm != NULL, ("[pmc,%d] null pmc", __LINE__)); 2764 2765 PMCDBG3(PMC,OPS,1, "stop pmc=%p mode=%d ri=%d", pm, 2766 PMC_TO_MODE(pm), PMC_TO_ROWINDEX(pm)); 2767 2768 pm->pm_state = PMC_STATE_STOPPED; 2769 2770 /* 2771 * If the PMC is a virtual mode one, changing the state to 2772 * non-RUNNING is enough to ensure that the PMC never gets 2773 * scheduled. 2774 * 2775 * If this PMC is current running on a CPU, then it will 2776 * handled correctly at the time its target process is context 2777 * switched out. 2778 */ 2779 2780 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) 2781 return 0; 2782 2783 /* 2784 * A system-mode PMC. Move to the CPU associated with 2785 * this PMC, and stop the hardware. We update the 2786 * 'initial count' so that a subsequent PMCSTART will 2787 * resume counting from the current hardware count. 2788 */ 2789 2790 pmc_save_cpu_binding(&pb); 2791 2792 cpu = PMC_TO_CPU(pm); 2793 2794 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 2795 ("[pmc,%d] illegal cpu=%d", __LINE__, cpu)); 2796 2797 if (!pmc_cpu_is_active(cpu)) 2798 return ENXIO; 2799 2800 pmc_select_cpu(cpu); 2801 2802 ri = PMC_TO_ROWINDEX(pm); 2803 pcd = pmc_ri_to_classdep(md, ri, &adjri); 2804 2805 CPU_CLR_ATOMIC(cpu, &pm->pm_cpustate); 2806 critical_enter(); 2807 if ((error = pcd->pcd_stop_pmc(cpu, adjri)) == 0) 2808 error = pcd->pcd_read_pmc(cpu, adjri, &pm->pm_sc.pm_initial); 2809 critical_exit(); 2810 2811 pmc_restore_cpu_binding(&pb); 2812 2813 po = pm->pm_owner; 2814 2815 /* remove this owner from the global list of SS PMC owners */ 2816 if (PMC_TO_MODE(pm) == PMC_MODE_SS) { 2817 po->po_sscount--; 2818 if (po->po_sscount == 0) { 2819 atomic_subtract_rel_int(&pmc_ss_count, 1); 2820 LIST_REMOVE(po, po_ssnext); 2821 PMCDBG1(PMC,OPS,2,"po=%p removed from global list", po); 2822 } 2823 } 2824 2825 return (error); 2826 } 2827 2828 2829 #ifdef HWPMC_DEBUG 2830 static const char *pmc_op_to_name[] = { 2831 #undef __PMC_OP 2832 #define __PMC_OP(N, D) #N , 2833 __PMC_OPS() 2834 NULL 2835 }; 2836 #endif 2837 2838 /* 2839 * The syscall interface 2840 */ 2841 2842 #define PMC_GET_SX_XLOCK(...) do { \ 2843 sx_xlock(&pmc_sx); \ 2844 if (pmc_hook == NULL) { \ 2845 sx_xunlock(&pmc_sx); \ 2846 return __VA_ARGS__; \ 2847 } \ 2848 } while (0) 2849 2850 #define PMC_DOWNGRADE_SX() do { \ 2851 sx_downgrade(&pmc_sx); \ 2852 is_sx_downgraded = 1; \ 2853 } while (0) 2854 2855 static int 2856 pmc_syscall_handler(struct thread *td, void *syscall_args) 2857 { 2858 int error, is_sx_downgraded, op; 2859 struct pmc_syscall_args *c; 2860 void *pmclog_proc_handle; 2861 void *arg; 2862 2863 c = (struct pmc_syscall_args *)syscall_args; 2864 op = c->pmop_code; 2865 arg = c->pmop_data; 2866 if (op == PMC_OP_CONFIGURELOG) { 2867 /* 2868 * We cannot create the logging process inside 2869 * pmclog_configure_log() because there is a LOR 2870 * between pmc_sx and process structure locks. 2871 * Instead, pre-create the process and ignite the loop 2872 * if everything is fine, otherwise direct the process 2873 * to exit. 2874 */ 2875 error = pmclog_proc_create(td, &pmclog_proc_handle); 2876 if (error != 0) 2877 goto done_syscall; 2878 } 2879 2880 PMC_GET_SX_XLOCK(ENOSYS); 2881 is_sx_downgraded = 0; 2882 2883 PMCDBG3(MOD,PMS,1, "syscall op=%d \"%s\" arg=%p", op, 2884 pmc_op_to_name[op], arg); 2885 2886 error = 0; 2887 atomic_add_int(&pmc_stats.pm_syscalls, 1); 2888 2889 switch (op) { 2890 2891 2892 /* 2893 * Configure a log file. 2894 * 2895 * XXX This OP will be reworked. 2896 */ 2897 2898 case PMC_OP_CONFIGURELOG: 2899 { 2900 struct proc *p; 2901 struct pmc *pm; 2902 struct pmc_owner *po; 2903 struct pmc_op_configurelog cl; 2904 2905 if ((error = copyin(arg, &cl, sizeof(cl))) != 0) { 2906 pmclog_proc_ignite(pmclog_proc_handle, NULL); 2907 break; 2908 } 2909 2910 /* mark this process as owning a log file */ 2911 p = td->td_proc; 2912 if ((po = pmc_find_owner_descriptor(p)) == NULL) 2913 if ((po = pmc_allocate_owner_descriptor(p)) == NULL) { 2914 pmclog_proc_ignite(pmclog_proc_handle, NULL); 2915 error = ENOMEM; 2916 break; 2917 } 2918 2919 /* 2920 * If a valid fd was passed in, try to configure that, 2921 * otherwise if 'fd' was less than zero and there was 2922 * a log file configured, flush its buffers and 2923 * de-configure it. 2924 */ 2925 if (cl.pm_logfd >= 0) { 2926 error = pmclog_configure_log(md, po, cl.pm_logfd); 2927 pmclog_proc_ignite(pmclog_proc_handle, error == 0 ? 2928 po : NULL); 2929 } else if (po->po_flags & PMC_PO_OWNS_LOGFILE) { 2930 pmclog_proc_ignite(pmclog_proc_handle, NULL); 2931 pmclog_process_closelog(po); 2932 error = pmclog_close(po); 2933 if (error == 0) { 2934 LIST_FOREACH(pm, &po->po_pmcs, pm_next) 2935 if (pm->pm_flags & PMC_F_NEEDS_LOGFILE && 2936 pm->pm_state == PMC_STATE_RUNNING) 2937 pmc_stop(pm); 2938 error = pmclog_deconfigure_log(po); 2939 } 2940 } else { 2941 pmclog_proc_ignite(pmclog_proc_handle, NULL); 2942 error = EINVAL; 2943 } 2944 } 2945 break; 2946 2947 /* 2948 * Flush a log file. 2949 */ 2950 2951 case PMC_OP_FLUSHLOG: 2952 { 2953 struct pmc_owner *po; 2954 2955 sx_assert(&pmc_sx, SX_XLOCKED); 2956 2957 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 2958 error = EINVAL; 2959 break; 2960 } 2961 2962 error = pmclog_flush(po); 2963 } 2964 break; 2965 2966 /* 2967 * Close a log file. 2968 */ 2969 2970 case PMC_OP_CLOSELOG: 2971 { 2972 struct pmc_owner *po; 2973 2974 sx_assert(&pmc_sx, SX_XLOCKED); 2975 2976 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 2977 error = EINVAL; 2978 break; 2979 } 2980 2981 error = pmclog_close(po); 2982 } 2983 break; 2984 2985 /* 2986 * Retrieve hardware configuration. 2987 */ 2988 2989 case PMC_OP_GETCPUINFO: /* CPU information */ 2990 { 2991 struct pmc_op_getcpuinfo gci; 2992 struct pmc_classinfo *pci; 2993 struct pmc_classdep *pcd; 2994 int cl; 2995 2996 gci.pm_cputype = md->pmd_cputype; 2997 gci.pm_ncpu = pmc_cpu_max(); 2998 gci.pm_npmc = md->pmd_npmc; 2999 gci.pm_nclass = md->pmd_nclass; 3000 pci = gci.pm_classes; 3001 pcd = md->pmd_classdep; 3002 for (cl = 0; cl < md->pmd_nclass; cl++, pci++, pcd++) { 3003 pci->pm_caps = pcd->pcd_caps; 3004 pci->pm_class = pcd->pcd_class; 3005 pci->pm_width = pcd->pcd_width; 3006 pci->pm_num = pcd->pcd_num; 3007 } 3008 error = copyout(&gci, arg, sizeof(gci)); 3009 } 3010 break; 3011 3012 /* 3013 * Retrieve soft events list. 3014 */ 3015 case PMC_OP_GETDYNEVENTINFO: 3016 { 3017 enum pmc_class cl; 3018 enum pmc_event ev; 3019 struct pmc_op_getdyneventinfo *gei; 3020 struct pmc_dyn_event_descr dev; 3021 struct pmc_soft *ps; 3022 uint32_t nevent; 3023 3024 sx_assert(&pmc_sx, SX_LOCKED); 3025 3026 gei = (struct pmc_op_getdyneventinfo *) arg; 3027 3028 if ((error = copyin(&gei->pm_class, &cl, sizeof(cl))) != 0) 3029 break; 3030 3031 /* Only SOFT class is dynamic. */ 3032 if (cl != PMC_CLASS_SOFT) { 3033 error = EINVAL; 3034 break; 3035 } 3036 3037 nevent = 0; 3038 for (ev = PMC_EV_SOFT_FIRST; (int)ev <= PMC_EV_SOFT_LAST; ev++) { 3039 ps = pmc_soft_ev_acquire(ev); 3040 if (ps == NULL) 3041 continue; 3042 bcopy(&ps->ps_ev, &dev, sizeof(dev)); 3043 pmc_soft_ev_release(ps); 3044 3045 error = copyout(&dev, 3046 &gei->pm_events[nevent], 3047 sizeof(struct pmc_dyn_event_descr)); 3048 if (error != 0) 3049 break; 3050 nevent++; 3051 } 3052 if (error != 0) 3053 break; 3054 3055 error = copyout(&nevent, &gei->pm_nevent, 3056 sizeof(nevent)); 3057 } 3058 break; 3059 3060 /* 3061 * Get module statistics 3062 */ 3063 3064 case PMC_OP_GETDRIVERSTATS: 3065 { 3066 struct pmc_op_getdriverstats gms; 3067 3068 bcopy(&pmc_stats, &gms, sizeof(gms)); 3069 error = copyout(&gms, arg, sizeof(gms)); 3070 } 3071 break; 3072 3073 3074 /* 3075 * Retrieve module version number 3076 */ 3077 3078 case PMC_OP_GETMODULEVERSION: 3079 { 3080 uint32_t cv, modv; 3081 3082 /* retrieve the client's idea of the ABI version */ 3083 if ((error = copyin(arg, &cv, sizeof(uint32_t))) != 0) 3084 break; 3085 /* don't service clients newer than our driver */ 3086 modv = PMC_VERSION; 3087 if ((cv & 0xFFFF0000) > (modv & 0xFFFF0000)) { 3088 error = EPROGMISMATCH; 3089 break; 3090 } 3091 error = copyout(&modv, arg, sizeof(int)); 3092 } 3093 break; 3094 3095 3096 /* 3097 * Retrieve the state of all the PMCs on a given 3098 * CPU. 3099 */ 3100 3101 case PMC_OP_GETPMCINFO: 3102 { 3103 int ari; 3104 struct pmc *pm; 3105 size_t pmcinfo_size; 3106 uint32_t cpu, n, npmc; 3107 struct pmc_owner *po; 3108 struct pmc_binding pb; 3109 struct pmc_classdep *pcd; 3110 struct pmc_info *p, *pmcinfo; 3111 struct pmc_op_getpmcinfo *gpi; 3112 3113 PMC_DOWNGRADE_SX(); 3114 3115 gpi = (struct pmc_op_getpmcinfo *) arg; 3116 3117 if ((error = copyin(&gpi->pm_cpu, &cpu, sizeof(cpu))) != 0) 3118 break; 3119 3120 if (cpu >= pmc_cpu_max()) { 3121 error = EINVAL; 3122 break; 3123 } 3124 3125 if (!pmc_cpu_is_active(cpu)) { 3126 error = ENXIO; 3127 break; 3128 } 3129 3130 /* switch to CPU 'cpu' */ 3131 pmc_save_cpu_binding(&pb); 3132 pmc_select_cpu(cpu); 3133 3134 npmc = md->pmd_npmc; 3135 3136 pmcinfo_size = npmc * sizeof(struct pmc_info); 3137 pmcinfo = malloc(pmcinfo_size, M_PMC, M_WAITOK); 3138 3139 p = pmcinfo; 3140 3141 for (n = 0; n < md->pmd_npmc; n++, p++) { 3142 3143 pcd = pmc_ri_to_classdep(md, n, &ari); 3144 3145 KASSERT(pcd != NULL, 3146 ("[pmc,%d] null pcd ri=%d", __LINE__, n)); 3147 3148 if ((error = pcd->pcd_describe(cpu, ari, p, &pm)) != 0) 3149 break; 3150 3151 if (PMC_ROW_DISP_IS_STANDALONE(n)) 3152 p->pm_rowdisp = PMC_DISP_STANDALONE; 3153 else if (PMC_ROW_DISP_IS_THREAD(n)) 3154 p->pm_rowdisp = PMC_DISP_THREAD; 3155 else 3156 p->pm_rowdisp = PMC_DISP_FREE; 3157 3158 p->pm_ownerpid = -1; 3159 3160 if (pm == NULL) /* no PMC associated */ 3161 continue; 3162 3163 po = pm->pm_owner; 3164 3165 KASSERT(po->po_owner != NULL, 3166 ("[pmc,%d] pmc_owner had a null proc pointer", 3167 __LINE__)); 3168 3169 p->pm_ownerpid = po->po_owner->p_pid; 3170 p->pm_mode = PMC_TO_MODE(pm); 3171 p->pm_event = pm->pm_event; 3172 p->pm_flags = pm->pm_flags; 3173 3174 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 3175 p->pm_reloadcount = 3176 pm->pm_sc.pm_reloadcount; 3177 } 3178 3179 pmc_restore_cpu_binding(&pb); 3180 3181 /* now copy out the PMC info collected */ 3182 if (error == 0) 3183 error = copyout(pmcinfo, &gpi->pm_pmcs, pmcinfo_size); 3184 3185 free(pmcinfo, M_PMC); 3186 } 3187 break; 3188 3189 3190 /* 3191 * Set the administrative state of a PMC. I.e. whether 3192 * the PMC is to be used or not. 3193 */ 3194 3195 case PMC_OP_PMCADMIN: 3196 { 3197 int cpu, ri; 3198 enum pmc_state request; 3199 struct pmc_cpu *pc; 3200 struct pmc_hw *phw; 3201 struct pmc_op_pmcadmin pma; 3202 struct pmc_binding pb; 3203 3204 sx_assert(&pmc_sx, SX_XLOCKED); 3205 3206 KASSERT(td == curthread, 3207 ("[pmc,%d] td != curthread", __LINE__)); 3208 3209 error = priv_check(td, PRIV_PMC_MANAGE); 3210 if (error) 3211 break; 3212 3213 if ((error = copyin(arg, &pma, sizeof(pma))) != 0) 3214 break; 3215 3216 cpu = pma.pm_cpu; 3217 3218 if (cpu < 0 || cpu >= (int) pmc_cpu_max()) { 3219 error = EINVAL; 3220 break; 3221 } 3222 3223 if (!pmc_cpu_is_active(cpu)) { 3224 error = ENXIO; 3225 break; 3226 } 3227 3228 request = pma.pm_state; 3229 3230 if (request != PMC_STATE_DISABLED && 3231 request != PMC_STATE_FREE) { 3232 error = EINVAL; 3233 break; 3234 } 3235 3236 ri = pma.pm_pmc; /* pmc id == row index */ 3237 if (ri < 0 || ri >= (int) md->pmd_npmc) { 3238 error = EINVAL; 3239 break; 3240 } 3241 3242 /* 3243 * We can't disable a PMC with a row-index allocated 3244 * for process virtual PMCs. 3245 */ 3246 3247 if (PMC_ROW_DISP_IS_THREAD(ri) && 3248 request == PMC_STATE_DISABLED) { 3249 error = EBUSY; 3250 break; 3251 } 3252 3253 /* 3254 * otherwise, this PMC on this CPU is either free or 3255 * in system-wide mode. 3256 */ 3257 3258 pmc_save_cpu_binding(&pb); 3259 pmc_select_cpu(cpu); 3260 3261 pc = pmc_pcpu[cpu]; 3262 phw = pc->pc_hwpmcs[ri]; 3263 3264 /* 3265 * XXX do we need some kind of 'forced' disable? 3266 */ 3267 3268 if (phw->phw_pmc == NULL) { 3269 if (request == PMC_STATE_DISABLED && 3270 (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED)) { 3271 phw->phw_state &= ~PMC_PHW_FLAG_IS_ENABLED; 3272 PMC_MARK_ROW_STANDALONE(ri); 3273 } else if (request == PMC_STATE_FREE && 3274 (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0) { 3275 phw->phw_state |= PMC_PHW_FLAG_IS_ENABLED; 3276 PMC_UNMARK_ROW_STANDALONE(ri); 3277 } 3278 /* other cases are a no-op */ 3279 } else 3280 error = EBUSY; 3281 3282 pmc_restore_cpu_binding(&pb); 3283 } 3284 break; 3285 3286 3287 /* 3288 * Allocate a PMC. 3289 */ 3290 3291 case PMC_OP_PMCALLOCATE: 3292 { 3293 int adjri, n; 3294 u_int cpu; 3295 uint32_t caps; 3296 struct pmc *pmc; 3297 enum pmc_mode mode; 3298 struct pmc_hw *phw; 3299 struct pmc_binding pb; 3300 struct pmc_classdep *pcd; 3301 struct pmc_op_pmcallocate pa; 3302 3303 if ((error = copyin(arg, &pa, sizeof(pa))) != 0) 3304 break; 3305 3306 caps = pa.pm_caps; 3307 mode = pa.pm_mode; 3308 cpu = pa.pm_cpu; 3309 3310 if ((mode != PMC_MODE_SS && mode != PMC_MODE_SC && 3311 mode != PMC_MODE_TS && mode != PMC_MODE_TC) || 3312 (cpu != (u_int) PMC_CPU_ANY && cpu >= pmc_cpu_max())) { 3313 error = EINVAL; 3314 break; 3315 } 3316 3317 /* 3318 * Virtual PMCs should only ask for a default CPU. 3319 * System mode PMCs need to specify a non-default CPU. 3320 */ 3321 3322 if ((PMC_IS_VIRTUAL_MODE(mode) && cpu != (u_int) PMC_CPU_ANY) || 3323 (PMC_IS_SYSTEM_MODE(mode) && cpu == (u_int) PMC_CPU_ANY)) { 3324 error = EINVAL; 3325 break; 3326 } 3327 3328 /* 3329 * Check that an inactive CPU is not being asked for. 3330 */ 3331 3332 if (PMC_IS_SYSTEM_MODE(mode) && !pmc_cpu_is_active(cpu)) { 3333 error = ENXIO; 3334 break; 3335 } 3336 3337 /* 3338 * Refuse an allocation for a system-wide PMC if this 3339 * process has been jailed, or if this process lacks 3340 * super-user credentials and the sysctl tunable 3341 * 'security.bsd.unprivileged_syspmcs' is zero. 3342 */ 3343 3344 if (PMC_IS_SYSTEM_MODE(mode)) { 3345 if (jailed(curthread->td_ucred)) { 3346 error = EPERM; 3347 break; 3348 } 3349 if (!pmc_unprivileged_syspmcs) { 3350 error = priv_check(curthread, 3351 PRIV_PMC_SYSTEM); 3352 if (error) 3353 break; 3354 } 3355 } 3356 3357 /* 3358 * Look for valid values for 'pm_flags' 3359 */ 3360 3361 if ((pa.pm_flags & ~(PMC_F_DESCENDANTS | PMC_F_LOG_PROCCSW | 3362 PMC_F_LOG_PROCEXIT | PMC_F_CALLCHAIN)) != 0) { 3363 error = EINVAL; 3364 break; 3365 } 3366 3367 /* process logging options are not allowed for system PMCs */ 3368 if (PMC_IS_SYSTEM_MODE(mode) && (pa.pm_flags & 3369 (PMC_F_LOG_PROCCSW | PMC_F_LOG_PROCEXIT))) { 3370 error = EINVAL; 3371 break; 3372 } 3373 3374 /* 3375 * All sampling mode PMCs need to be able to interrupt the 3376 * CPU. 3377 */ 3378 if (PMC_IS_SAMPLING_MODE(mode)) 3379 caps |= PMC_CAP_INTERRUPT; 3380 3381 /* A valid class specifier should have been passed in. */ 3382 for (n = 0; n < md->pmd_nclass; n++) 3383 if (md->pmd_classdep[n].pcd_class == pa.pm_class) 3384 break; 3385 if (n == md->pmd_nclass) { 3386 error = EINVAL; 3387 break; 3388 } 3389 3390 /* The requested PMC capabilities should be feasible. */ 3391 if ((md->pmd_classdep[n].pcd_caps & caps) != caps) { 3392 error = EOPNOTSUPP; 3393 break; 3394 } 3395 3396 PMCDBG4(PMC,ALL,2, "event=%d caps=0x%x mode=%d cpu=%d", 3397 pa.pm_ev, caps, mode, cpu); 3398 3399 pmc = pmc_allocate_pmc_descriptor(); 3400 pmc->pm_id = PMC_ID_MAKE_ID(cpu,pa.pm_mode,pa.pm_class, 3401 PMC_ID_INVALID); 3402 pmc->pm_event = pa.pm_ev; 3403 pmc->pm_state = PMC_STATE_FREE; 3404 pmc->pm_caps = caps; 3405 pmc->pm_flags = pa.pm_flags; 3406 3407 /* switch thread to CPU 'cpu' */ 3408 pmc_save_cpu_binding(&pb); 3409 3410 #define PMC_IS_SHAREABLE_PMC(cpu, n) \ 3411 (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_state & \ 3412 PMC_PHW_FLAG_IS_SHAREABLE) 3413 #define PMC_IS_UNALLOCATED(cpu, n) \ 3414 (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_pmc == NULL) 3415 3416 if (PMC_IS_SYSTEM_MODE(mode)) { 3417 pmc_select_cpu(cpu); 3418 for (n = 0; n < (int) md->pmd_npmc; n++) { 3419 pcd = pmc_ri_to_classdep(md, n, &adjri); 3420 if (pmc_can_allocate_row(n, mode) == 0 && 3421 pmc_can_allocate_rowindex( 3422 curthread->td_proc, n, cpu) == 0 && 3423 (PMC_IS_UNALLOCATED(cpu, n) || 3424 PMC_IS_SHAREABLE_PMC(cpu, n)) && 3425 pcd->pcd_allocate_pmc(cpu, adjri, pmc, 3426 &pa) == 0) 3427 break; 3428 } 3429 } else { 3430 /* Process virtual mode */ 3431 for (n = 0; n < (int) md->pmd_npmc; n++) { 3432 pcd = pmc_ri_to_classdep(md, n, &adjri); 3433 if (pmc_can_allocate_row(n, mode) == 0 && 3434 pmc_can_allocate_rowindex( 3435 curthread->td_proc, n, 3436 PMC_CPU_ANY) == 0 && 3437 pcd->pcd_allocate_pmc(curthread->td_oncpu, 3438 adjri, pmc, &pa) == 0) 3439 break; 3440 } 3441 } 3442 3443 #undef PMC_IS_UNALLOCATED 3444 #undef PMC_IS_SHAREABLE_PMC 3445 3446 pmc_restore_cpu_binding(&pb); 3447 3448 if (n == (int) md->pmd_npmc) { 3449 pmc_destroy_pmc_descriptor(pmc); 3450 pmc = NULL; 3451 error = EINVAL; 3452 break; 3453 } 3454 3455 /* Fill in the correct value in the ID field */ 3456 pmc->pm_id = PMC_ID_MAKE_ID(cpu,mode,pa.pm_class,n); 3457 3458 PMCDBG5(PMC,ALL,2, "ev=%d class=%d mode=%d n=%d -> pmcid=%x", 3459 pmc->pm_event, pa.pm_class, mode, n, pmc->pm_id); 3460 3461 /* Process mode PMCs with logging enabled need log files */ 3462 if (pmc->pm_flags & (PMC_F_LOG_PROCEXIT | PMC_F_LOG_PROCCSW)) 3463 pmc->pm_flags |= PMC_F_NEEDS_LOGFILE; 3464 3465 /* All system mode sampling PMCs require a log file */ 3466 if (PMC_IS_SAMPLING_MODE(mode) && PMC_IS_SYSTEM_MODE(mode)) 3467 pmc->pm_flags |= PMC_F_NEEDS_LOGFILE; 3468 3469 /* 3470 * Configure global pmc's immediately 3471 */ 3472 3473 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pmc))) { 3474 3475 pmc_save_cpu_binding(&pb); 3476 pmc_select_cpu(cpu); 3477 3478 phw = pmc_pcpu[cpu]->pc_hwpmcs[n]; 3479 pcd = pmc_ri_to_classdep(md, n, &adjri); 3480 3481 if ((phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0 || 3482 (error = pcd->pcd_config_pmc(cpu, adjri, pmc)) != 0) { 3483 (void) pcd->pcd_release_pmc(cpu, adjri, pmc); 3484 pmc_destroy_pmc_descriptor(pmc); 3485 pmc = NULL; 3486 pmc_restore_cpu_binding(&pb); 3487 error = EPERM; 3488 break; 3489 } 3490 3491 pmc_restore_cpu_binding(&pb); 3492 } 3493 3494 pmc->pm_state = PMC_STATE_ALLOCATED; 3495 3496 /* 3497 * mark row disposition 3498 */ 3499 3500 if (PMC_IS_SYSTEM_MODE(mode)) 3501 PMC_MARK_ROW_STANDALONE(n); 3502 else 3503 PMC_MARK_ROW_THREAD(n); 3504 3505 /* 3506 * Register this PMC with the current thread as its owner. 3507 */ 3508 3509 if ((error = 3510 pmc_register_owner(curthread->td_proc, pmc)) != 0) { 3511 pmc_release_pmc_descriptor(pmc); 3512 pmc_destroy_pmc_descriptor(pmc); 3513 pmc = NULL; 3514 break; 3515 } 3516 3517 /* 3518 * Return the allocated index. 3519 */ 3520 3521 pa.pm_pmcid = pmc->pm_id; 3522 3523 error = copyout(&pa, arg, sizeof(pa)); 3524 } 3525 break; 3526 3527 3528 /* 3529 * Attach a PMC to a process. 3530 */ 3531 3532 case PMC_OP_PMCATTACH: 3533 { 3534 struct pmc *pm; 3535 struct proc *p; 3536 struct pmc_op_pmcattach a; 3537 3538 sx_assert(&pmc_sx, SX_XLOCKED); 3539 3540 if ((error = copyin(arg, &a, sizeof(a))) != 0) 3541 break; 3542 3543 if (a.pm_pid < 0) { 3544 error = EINVAL; 3545 break; 3546 } else if (a.pm_pid == 0) 3547 a.pm_pid = td->td_proc->p_pid; 3548 3549 if ((error = pmc_find_pmc(a.pm_pmc, &pm)) != 0) 3550 break; 3551 3552 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) { 3553 error = EINVAL; 3554 break; 3555 } 3556 3557 /* PMCs may be (re)attached only when allocated or stopped */ 3558 if (pm->pm_state == PMC_STATE_RUNNING) { 3559 error = EBUSY; 3560 break; 3561 } else if (pm->pm_state != PMC_STATE_ALLOCATED && 3562 pm->pm_state != PMC_STATE_STOPPED) { 3563 error = EINVAL; 3564 break; 3565 } 3566 3567 /* lookup pid */ 3568 if ((p = pfind(a.pm_pid)) == NULL) { 3569 error = ESRCH; 3570 break; 3571 } 3572 3573 /* 3574 * Ignore processes that are working on exiting. 3575 */ 3576 if (p->p_flag & P_WEXIT) { 3577 error = ESRCH; 3578 PROC_UNLOCK(p); /* pfind() returns a locked process */ 3579 break; 3580 } 3581 3582 /* 3583 * we are allowed to attach a PMC to a process if 3584 * we can debug it. 3585 */ 3586 error = p_candebug(curthread, p); 3587 3588 PROC_UNLOCK(p); 3589 3590 if (error == 0) 3591 error = pmc_attach_process(p, pm); 3592 } 3593 break; 3594 3595 3596 /* 3597 * Detach an attached PMC from a process. 3598 */ 3599 3600 case PMC_OP_PMCDETACH: 3601 { 3602 struct pmc *pm; 3603 struct proc *p; 3604 struct pmc_op_pmcattach a; 3605 3606 if ((error = copyin(arg, &a, sizeof(a))) != 0) 3607 break; 3608 3609 if (a.pm_pid < 0) { 3610 error = EINVAL; 3611 break; 3612 } else if (a.pm_pid == 0) 3613 a.pm_pid = td->td_proc->p_pid; 3614 3615 if ((error = pmc_find_pmc(a.pm_pmc, &pm)) != 0) 3616 break; 3617 3618 if ((p = pfind(a.pm_pid)) == NULL) { 3619 error = ESRCH; 3620 break; 3621 } 3622 3623 /* 3624 * Treat processes that are in the process of exiting 3625 * as if they were not present. 3626 */ 3627 3628 if (p->p_flag & P_WEXIT) 3629 error = ESRCH; 3630 3631 PROC_UNLOCK(p); /* pfind() returns a locked process */ 3632 3633 if (error == 0) 3634 error = pmc_detach_process(p, pm); 3635 } 3636 break; 3637 3638 3639 /* 3640 * Retrieve the MSR number associated with the counter 3641 * 'pmc_id'. This allows processes to directly use RDPMC 3642 * instructions to read their PMCs, without the overhead of a 3643 * system call. 3644 */ 3645 3646 case PMC_OP_PMCGETMSR: 3647 { 3648 int adjri, ri; 3649 struct pmc *pm; 3650 struct pmc_target *pt; 3651 struct pmc_op_getmsr gm; 3652 struct pmc_classdep *pcd; 3653 3654 PMC_DOWNGRADE_SX(); 3655 3656 if ((error = copyin(arg, &gm, sizeof(gm))) != 0) 3657 break; 3658 3659 if ((error = pmc_find_pmc(gm.pm_pmcid, &pm)) != 0) 3660 break; 3661 3662 /* 3663 * The allocated PMC has to be a process virtual PMC, 3664 * i.e., of type MODE_T[CS]. Global PMCs can only be 3665 * read using the PMCREAD operation since they may be 3666 * allocated on a different CPU than the one we could 3667 * be running on at the time of the RDPMC instruction. 3668 * 3669 * The GETMSR operation is not allowed for PMCs that 3670 * are inherited across processes. 3671 */ 3672 3673 if (!PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)) || 3674 (pm->pm_flags & PMC_F_DESCENDANTS)) { 3675 error = EINVAL; 3676 break; 3677 } 3678 3679 /* 3680 * It only makes sense to use a RDPMC (or its 3681 * equivalent instruction on non-x86 architectures) on 3682 * a process that has allocated and attached a PMC to 3683 * itself. Conversely the PMC is only allowed to have 3684 * one process attached to it -- its owner. 3685 */ 3686 3687 if ((pt = LIST_FIRST(&pm->pm_targets)) == NULL || 3688 LIST_NEXT(pt, pt_next) != NULL || 3689 pt->pt_process->pp_proc != pm->pm_owner->po_owner) { 3690 error = EINVAL; 3691 break; 3692 } 3693 3694 ri = PMC_TO_ROWINDEX(pm); 3695 pcd = pmc_ri_to_classdep(md, ri, &adjri); 3696 3697 /* PMC class has no 'GETMSR' support */ 3698 if (pcd->pcd_get_msr == NULL) { 3699 error = ENOSYS; 3700 break; 3701 } 3702 3703 if ((error = (*pcd->pcd_get_msr)(adjri, &gm.pm_msr)) < 0) 3704 break; 3705 3706 if ((error = copyout(&gm, arg, sizeof(gm))) < 0) 3707 break; 3708 3709 /* 3710 * Mark our process as using MSRs. Update machine 3711 * state using a forced context switch. 3712 */ 3713 3714 pt->pt_process->pp_flags |= PMC_PP_ENABLE_MSR_ACCESS; 3715 pmc_force_context_switch(); 3716 3717 } 3718 break; 3719 3720 /* 3721 * Release an allocated PMC 3722 */ 3723 3724 case PMC_OP_PMCRELEASE: 3725 { 3726 pmc_id_t pmcid; 3727 struct pmc *pm; 3728 struct pmc_owner *po; 3729 struct pmc_op_simple sp; 3730 3731 /* 3732 * Find PMC pointer for the named PMC. 3733 * 3734 * Use pmc_release_pmc_descriptor() to switch off the 3735 * PMC, remove all its target threads, and remove the 3736 * PMC from its owner's list. 3737 * 3738 * Remove the owner record if this is the last PMC 3739 * owned. 3740 * 3741 * Free up space. 3742 */ 3743 3744 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 3745 break; 3746 3747 pmcid = sp.pm_pmcid; 3748 3749 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 3750 break; 3751 3752 po = pm->pm_owner; 3753 pmc_release_pmc_descriptor(pm); 3754 pmc_maybe_remove_owner(po); 3755 pmc_destroy_pmc_descriptor(pm); 3756 } 3757 break; 3758 3759 3760 /* 3761 * Read and/or write a PMC. 3762 */ 3763 3764 case PMC_OP_PMCRW: 3765 { 3766 int adjri; 3767 struct pmc *pm; 3768 uint32_t cpu, ri; 3769 pmc_value_t oldvalue; 3770 struct pmc_binding pb; 3771 struct pmc_op_pmcrw prw; 3772 struct pmc_classdep *pcd; 3773 struct pmc_op_pmcrw *pprw; 3774 3775 PMC_DOWNGRADE_SX(); 3776 3777 if ((error = copyin(arg, &prw, sizeof(prw))) != 0) 3778 break; 3779 3780 ri = 0; 3781 PMCDBG2(PMC,OPS,1, "rw id=%d flags=0x%x", prw.pm_pmcid, 3782 prw.pm_flags); 3783 3784 /* must have at least one flag set */ 3785 if ((prw.pm_flags & (PMC_F_OLDVALUE|PMC_F_NEWVALUE)) == 0) { 3786 error = EINVAL; 3787 break; 3788 } 3789 3790 /* locate pmc descriptor */ 3791 if ((error = pmc_find_pmc(prw.pm_pmcid, &pm)) != 0) 3792 break; 3793 3794 /* Can't read a PMC that hasn't been started. */ 3795 if (pm->pm_state != PMC_STATE_ALLOCATED && 3796 pm->pm_state != PMC_STATE_STOPPED && 3797 pm->pm_state != PMC_STATE_RUNNING) { 3798 error = EINVAL; 3799 break; 3800 } 3801 3802 /* writing a new value is allowed only for 'STOPPED' pmcs */ 3803 if (pm->pm_state == PMC_STATE_RUNNING && 3804 (prw.pm_flags & PMC_F_NEWVALUE)) { 3805 error = EBUSY; 3806 break; 3807 } 3808 3809 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) { 3810 3811 /* 3812 * If this PMC is attached to its owner (i.e., 3813 * the process requesting this operation) and 3814 * is running, then attempt to get an 3815 * upto-date reading from hardware for a READ. 3816 * Writes are only allowed when the PMC is 3817 * stopped, so only update the saved value 3818 * field. 3819 * 3820 * If the PMC is not running, or is not 3821 * attached to its owner, read/write to the 3822 * savedvalue field. 3823 */ 3824 3825 ri = PMC_TO_ROWINDEX(pm); 3826 pcd = pmc_ri_to_classdep(md, ri, &adjri); 3827 3828 mtx_pool_lock_spin(pmc_mtxpool, pm); 3829 cpu = curthread->td_oncpu; 3830 3831 if (prw.pm_flags & PMC_F_OLDVALUE) { 3832 if ((pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) && 3833 (pm->pm_state == PMC_STATE_RUNNING)) 3834 error = (*pcd->pcd_read_pmc)(cpu, adjri, 3835 &oldvalue); 3836 else 3837 oldvalue = pm->pm_gv.pm_savedvalue; 3838 } 3839 if (prw.pm_flags & PMC_F_NEWVALUE) 3840 pm->pm_gv.pm_savedvalue = prw.pm_value; 3841 3842 mtx_pool_unlock_spin(pmc_mtxpool, pm); 3843 3844 } else { /* System mode PMCs */ 3845 cpu = PMC_TO_CPU(pm); 3846 ri = PMC_TO_ROWINDEX(pm); 3847 pcd = pmc_ri_to_classdep(md, ri, &adjri); 3848 3849 if (!pmc_cpu_is_active(cpu)) { 3850 error = ENXIO; 3851 break; 3852 } 3853 3854 /* move this thread to CPU 'cpu' */ 3855 pmc_save_cpu_binding(&pb); 3856 pmc_select_cpu(cpu); 3857 3858 critical_enter(); 3859 /* save old value */ 3860 if (prw.pm_flags & PMC_F_OLDVALUE) 3861 if ((error = (*pcd->pcd_read_pmc)(cpu, adjri, 3862 &oldvalue))) 3863 goto error; 3864 /* write out new value */ 3865 if (prw.pm_flags & PMC_F_NEWVALUE) 3866 error = (*pcd->pcd_write_pmc)(cpu, adjri, 3867 prw.pm_value); 3868 error: 3869 critical_exit(); 3870 pmc_restore_cpu_binding(&pb); 3871 if (error) 3872 break; 3873 } 3874 3875 pprw = (struct pmc_op_pmcrw *) arg; 3876 3877 #ifdef HWPMC_DEBUG 3878 if (prw.pm_flags & PMC_F_NEWVALUE) 3879 PMCDBG3(PMC,OPS,2, "rw id=%d new %jx -> old %jx", 3880 ri, prw.pm_value, oldvalue); 3881 else if (prw.pm_flags & PMC_F_OLDVALUE) 3882 PMCDBG2(PMC,OPS,2, "rw id=%d -> old %jx", ri, oldvalue); 3883 #endif 3884 3885 /* return old value if requested */ 3886 if (prw.pm_flags & PMC_F_OLDVALUE) 3887 if ((error = copyout(&oldvalue, &pprw->pm_value, 3888 sizeof(prw.pm_value)))) 3889 break; 3890 3891 } 3892 break; 3893 3894 3895 /* 3896 * Set the sampling rate for a sampling mode PMC and the 3897 * initial count for a counting mode PMC. 3898 */ 3899 3900 case PMC_OP_PMCSETCOUNT: 3901 { 3902 struct pmc *pm; 3903 struct pmc_op_pmcsetcount sc; 3904 3905 PMC_DOWNGRADE_SX(); 3906 3907 if ((error = copyin(arg, &sc, sizeof(sc))) != 0) 3908 break; 3909 3910 if ((error = pmc_find_pmc(sc.pm_pmcid, &pm)) != 0) 3911 break; 3912 3913 if (pm->pm_state == PMC_STATE_RUNNING) { 3914 error = EBUSY; 3915 break; 3916 } 3917 3918 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 3919 pm->pm_sc.pm_reloadcount = sc.pm_count; 3920 else 3921 pm->pm_sc.pm_initial = sc.pm_count; 3922 } 3923 break; 3924 3925 3926 /* 3927 * Start a PMC. 3928 */ 3929 3930 case PMC_OP_PMCSTART: 3931 { 3932 pmc_id_t pmcid; 3933 struct pmc *pm; 3934 struct pmc_op_simple sp; 3935 3936 sx_assert(&pmc_sx, SX_XLOCKED); 3937 3938 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 3939 break; 3940 3941 pmcid = sp.pm_pmcid; 3942 3943 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 3944 break; 3945 3946 KASSERT(pmcid == pm->pm_id, 3947 ("[pmc,%d] pmcid %x != id %x", __LINE__, 3948 pm->pm_id, pmcid)); 3949 3950 if (pm->pm_state == PMC_STATE_RUNNING) /* already running */ 3951 break; 3952 else if (pm->pm_state != PMC_STATE_STOPPED && 3953 pm->pm_state != PMC_STATE_ALLOCATED) { 3954 error = EINVAL; 3955 break; 3956 } 3957 3958 error = pmc_start(pm); 3959 } 3960 break; 3961 3962 3963 /* 3964 * Stop a PMC. 3965 */ 3966 3967 case PMC_OP_PMCSTOP: 3968 { 3969 pmc_id_t pmcid; 3970 struct pmc *pm; 3971 struct pmc_op_simple sp; 3972 3973 PMC_DOWNGRADE_SX(); 3974 3975 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 3976 break; 3977 3978 pmcid = sp.pm_pmcid; 3979 3980 /* 3981 * Mark the PMC as inactive and invoke the MD stop 3982 * routines if needed. 3983 */ 3984 3985 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 3986 break; 3987 3988 KASSERT(pmcid == pm->pm_id, 3989 ("[pmc,%d] pmc id %x != pmcid %x", __LINE__, 3990 pm->pm_id, pmcid)); 3991 3992 if (pm->pm_state == PMC_STATE_STOPPED) /* already stopped */ 3993 break; 3994 else if (pm->pm_state != PMC_STATE_RUNNING) { 3995 error = EINVAL; 3996 break; 3997 } 3998 3999 error = pmc_stop(pm); 4000 } 4001 break; 4002 4003 4004 /* 4005 * Write a user supplied value to the log file. 4006 */ 4007 4008 case PMC_OP_WRITELOG: 4009 { 4010 struct pmc_op_writelog wl; 4011 struct pmc_owner *po; 4012 4013 PMC_DOWNGRADE_SX(); 4014 4015 if ((error = copyin(arg, &wl, sizeof(wl))) != 0) 4016 break; 4017 4018 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 4019 error = EINVAL; 4020 break; 4021 } 4022 4023 if ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) { 4024 error = EINVAL; 4025 break; 4026 } 4027 4028 error = pmclog_process_userlog(po, &wl); 4029 } 4030 break; 4031 4032 4033 default: 4034 error = EINVAL; 4035 break; 4036 } 4037 4038 if (is_sx_downgraded) 4039 sx_sunlock(&pmc_sx); 4040 else 4041 sx_xunlock(&pmc_sx); 4042 done_syscall: 4043 if (error) 4044 atomic_add_int(&pmc_stats.pm_syscall_errors, 1); 4045 4046 return (error); 4047 } 4048 4049 /* 4050 * Helper functions 4051 */ 4052 4053 4054 /* 4055 * Mark the thread as needing callchain capture and post an AST. The 4056 * actual callchain capture will be done in a context where it is safe 4057 * to take page faults. 4058 */ 4059 4060 static void 4061 pmc_post_callchain_callback(void) 4062 { 4063 struct thread *td; 4064 4065 td = curthread; 4066 4067 /* 4068 * If there is multiple PMCs for the same interrupt ignore new post 4069 */ 4070 if (td->td_pflags & TDP_CALLCHAIN) 4071 return; 4072 4073 /* 4074 * Mark this thread as needing callchain capture. 4075 * `td->td_pflags' will be safe to touch because this thread 4076 * was in user space when it was interrupted. 4077 */ 4078 td->td_pflags |= TDP_CALLCHAIN; 4079 4080 /* 4081 * Don't let this thread migrate between CPUs until callchain 4082 * capture completes. 4083 */ 4084 sched_pin(); 4085 4086 return; 4087 } 4088 4089 /* 4090 * Interrupt processing. 4091 * 4092 * Find a free slot in the per-cpu array of samples and capture the 4093 * current callchain there. If a sample was successfully added, a bit 4094 * is set in mask 'pmc_cpumask' denoting that the DO_SAMPLES hook 4095 * needs to be invoked from the clock handler. 4096 * 4097 * This function is meant to be called from an NMI handler. It cannot 4098 * use any of the locking primitives supplied by the OS. 4099 */ 4100 4101 int 4102 pmc_process_interrupt(int cpu, int ring, struct pmc *pm, struct trapframe *tf, 4103 int inuserspace) 4104 { 4105 int error, callchaindepth; 4106 struct thread *td; 4107 struct pmc_sample *ps; 4108 struct pmc_samplebuffer *psb; 4109 4110 error = 0; 4111 4112 /* 4113 * Allocate space for a sample buffer. 4114 */ 4115 psb = pmc_pcpu[cpu]->pc_sb[ring]; 4116 4117 ps = psb->ps_write; 4118 if (ps->ps_nsamples) { /* in use, reader hasn't caught up */ 4119 CPU_SET_ATOMIC(cpu, &pm->pm_stalled); 4120 atomic_add_int(&pmc_stats.pm_intr_bufferfull, 1); 4121 PMCDBG6(SAM,INT,1,"(spc) cpu=%d pm=%p tf=%p um=%d wr=%d rd=%d", 4122 cpu, pm, (void *) tf, inuserspace, 4123 (int) (psb->ps_write - psb->ps_samples), 4124 (int) (psb->ps_read - psb->ps_samples)); 4125 callchaindepth = 1; 4126 error = ENOMEM; 4127 goto done; 4128 } 4129 4130 4131 /* Fill in entry. */ 4132 PMCDBG6(SAM,INT,1,"cpu=%d pm=%p tf=%p um=%d wr=%d rd=%d", cpu, pm, 4133 (void *) tf, inuserspace, 4134 (int) (psb->ps_write - psb->ps_samples), 4135 (int) (psb->ps_read - psb->ps_samples)); 4136 4137 KASSERT(pm->pm_runcount >= 0, 4138 ("[pmc,%d] pm=%p runcount %d", __LINE__, (void *) pm, 4139 pm->pm_runcount)); 4140 4141 atomic_add_rel_int(&pm->pm_runcount, 1); /* hold onto PMC */ 4142 4143 ps->ps_pmc = pm; 4144 if ((td = curthread) && td->td_proc) 4145 ps->ps_pid = td->td_proc->p_pid; 4146 else 4147 ps->ps_pid = -1; 4148 ps->ps_cpu = cpu; 4149 ps->ps_td = td; 4150 ps->ps_flags = inuserspace ? PMC_CC_F_USERSPACE : 0; 4151 4152 callchaindepth = (pm->pm_flags & PMC_F_CALLCHAIN) ? 4153 pmc_callchaindepth : 1; 4154 4155 if (callchaindepth == 1) 4156 ps->ps_pc[0] = PMC_TRAPFRAME_TO_PC(tf); 4157 else { 4158 /* 4159 * Kernel stack traversals can be done immediately, 4160 * while we defer to an AST for user space traversals. 4161 */ 4162 if (!inuserspace) { 4163 callchaindepth = 4164 pmc_save_kernel_callchain(ps->ps_pc, 4165 callchaindepth, tf); 4166 } else { 4167 pmc_post_callchain_callback(); 4168 callchaindepth = PMC_SAMPLE_INUSE; 4169 } 4170 } 4171 4172 ps->ps_nsamples = callchaindepth; /* mark entry as in use */ 4173 4174 /* increment write pointer, modulo ring buffer size */ 4175 ps++; 4176 if (ps == psb->ps_fence) 4177 psb->ps_write = psb->ps_samples; 4178 else 4179 psb->ps_write = ps; 4180 4181 done: 4182 /* mark CPU as needing processing */ 4183 if (callchaindepth != PMC_SAMPLE_INUSE) 4184 CPU_SET_ATOMIC(cpu, &pmc_cpumask); 4185 4186 return (error); 4187 } 4188 4189 /* 4190 * Capture a user call chain. This function will be called from ast() 4191 * before control returns to userland and before the process gets 4192 * rescheduled. 4193 */ 4194 4195 static void 4196 pmc_capture_user_callchain(int cpu, int ring, struct trapframe *tf) 4197 { 4198 struct pmc *pm; 4199 struct thread *td; 4200 struct pmc_sample *ps, *ps_end; 4201 struct pmc_samplebuffer *psb; 4202 #ifdef INVARIANTS 4203 int ncallchains; 4204 int nfree; 4205 #endif 4206 4207 psb = pmc_pcpu[cpu]->pc_sb[ring]; 4208 td = curthread; 4209 4210 KASSERT(td->td_pflags & TDP_CALLCHAIN, 4211 ("[pmc,%d] Retrieving callchain for thread that doesn't want it", 4212 __LINE__)); 4213 4214 #ifdef INVARIANTS 4215 ncallchains = 0; 4216 nfree = 0; 4217 #endif 4218 4219 /* 4220 * Iterate through all deferred callchain requests. 4221 * Walk from the current read pointer to the current 4222 * write pointer. 4223 */ 4224 4225 ps = psb->ps_read; 4226 ps_end = psb->ps_write; 4227 do { 4228 #ifdef INVARIANTS 4229 if ((ps->ps_pmc == NULL) || 4230 (ps->ps_pmc->pm_state != PMC_STATE_RUNNING)) 4231 nfree++; 4232 #endif 4233 if (ps->ps_nsamples != PMC_SAMPLE_INUSE) 4234 goto next; 4235 if (ps->ps_td != td) 4236 goto next; 4237 4238 KASSERT(ps->ps_cpu == cpu, 4239 ("[pmc,%d] cpu mismatch ps_cpu=%d pcpu=%d", __LINE__, 4240 ps->ps_cpu, PCPU_GET(cpuid))); 4241 4242 pm = ps->ps_pmc; 4243 4244 KASSERT(pm->pm_flags & PMC_F_CALLCHAIN, 4245 ("[pmc,%d] Retrieving callchain for PMC that doesn't " 4246 "want it", __LINE__)); 4247 4248 KASSERT(pm->pm_runcount > 0, 4249 ("[pmc,%d] runcount %d", __LINE__, pm->pm_runcount)); 4250 4251 /* 4252 * Retrieve the callchain and mark the sample buffer 4253 * as 'processable' by the timer tick sweep code. 4254 */ 4255 ps->ps_nsamples = pmc_save_user_callchain(ps->ps_pc, 4256 pmc_callchaindepth, tf); 4257 4258 #ifdef INVARIANTS 4259 ncallchains++; 4260 #endif 4261 4262 next: 4263 /* increment the pointer, modulo sample ring size */ 4264 if (++ps == psb->ps_fence) 4265 ps = psb->ps_samples; 4266 } while (ps != ps_end); 4267 4268 #ifdef INVARIANTS 4269 KASSERT(ncallchains > 0 || nfree > 0, 4270 ("[pmc,%d] cpu %d didn't find a sample to collect", __LINE__, 4271 cpu)); 4272 #endif 4273 4274 KASSERT(td->td_pinned == 1, 4275 ("[pmc,%d] invalid td_pinned value", __LINE__)); 4276 sched_unpin(); /* Can migrate safely now. */ 4277 4278 /* mark CPU as needing processing */ 4279 CPU_SET_ATOMIC(cpu, &pmc_cpumask); 4280 4281 return; 4282 } 4283 4284 /* 4285 * Process saved PC samples. 4286 */ 4287 4288 static void 4289 pmc_process_samples(int cpu, int ring) 4290 { 4291 struct pmc *pm; 4292 int adjri, n; 4293 struct thread *td; 4294 struct pmc_owner *po; 4295 struct pmc_sample *ps; 4296 struct pmc_classdep *pcd; 4297 struct pmc_samplebuffer *psb; 4298 4299 KASSERT(PCPU_GET(cpuid) == cpu, 4300 ("[pmc,%d] not on the correct CPU pcpu=%d cpu=%d", __LINE__, 4301 PCPU_GET(cpuid), cpu)); 4302 4303 psb = pmc_pcpu[cpu]->pc_sb[ring]; 4304 4305 for (n = 0; n < pmc_nsamples; n++) { /* bound on #iterations */ 4306 4307 ps = psb->ps_read; 4308 if (ps->ps_nsamples == PMC_SAMPLE_FREE) 4309 break; 4310 4311 pm = ps->ps_pmc; 4312 4313 KASSERT(pm->pm_runcount > 0, 4314 ("[pmc,%d] pm=%p runcount %d", __LINE__, (void *) pm, 4315 pm->pm_runcount)); 4316 4317 po = pm->pm_owner; 4318 4319 KASSERT(PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)), 4320 ("[pmc,%d] pmc=%p non-sampling mode=%d", __LINE__, 4321 pm, PMC_TO_MODE(pm))); 4322 4323 /* Ignore PMCs that have been switched off */ 4324 if (pm->pm_state != PMC_STATE_RUNNING) 4325 goto entrydone; 4326 4327 /* If there is a pending AST wait for completion */ 4328 if (ps->ps_nsamples == PMC_SAMPLE_INUSE) { 4329 /* Need a rescan at a later time. */ 4330 CPU_SET_ATOMIC(cpu, &pmc_cpumask); 4331 break; 4332 } 4333 4334 PMCDBG6(SAM,OPS,1,"cpu=%d pm=%p n=%d fl=%x wr=%d rd=%d", cpu, 4335 pm, ps->ps_nsamples, ps->ps_flags, 4336 (int) (psb->ps_write - psb->ps_samples), 4337 (int) (psb->ps_read - psb->ps_samples)); 4338 4339 /* 4340 * If this is a process-mode PMC that is attached to 4341 * its owner, and if the PC is in user mode, update 4342 * profiling statistics like timer-based profiling 4343 * would have done. 4344 */ 4345 if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) { 4346 if (ps->ps_flags & PMC_CC_F_USERSPACE) { 4347 td = FIRST_THREAD_IN_PROC(po->po_owner); 4348 addupc_intr(td, ps->ps_pc[0], 1); 4349 } 4350 goto entrydone; 4351 } 4352 4353 /* 4354 * Otherwise, this is either a sampling mode PMC that 4355 * is attached to a different process than its owner, 4356 * or a system-wide sampling PMC. Dispatch a log 4357 * entry to the PMC's owner process. 4358 */ 4359 pmclog_process_callchain(pm, ps); 4360 4361 entrydone: 4362 ps->ps_nsamples = 0; /* mark entry as free */ 4363 atomic_subtract_rel_int(&pm->pm_runcount, 1); 4364 4365 /* increment read pointer, modulo sample size */ 4366 if (++ps == psb->ps_fence) 4367 psb->ps_read = psb->ps_samples; 4368 else 4369 psb->ps_read = ps; 4370 } 4371 4372 atomic_add_int(&pmc_stats.pm_log_sweeps, 1); 4373 4374 /* Do not re-enable stalled PMCs if we failed to process any samples */ 4375 if (n == 0) 4376 return; 4377 4378 /* 4379 * Restart any stalled sampling PMCs on this CPU. 4380 * 4381 * If the NMI handler sets the pm_stalled field of a PMC after 4382 * the check below, we'll end up processing the stalled PMC at 4383 * the next hardclock tick. 4384 */ 4385 for (n = 0; n < md->pmd_npmc; n++) { 4386 pcd = pmc_ri_to_classdep(md, n, &adjri); 4387 KASSERT(pcd != NULL, 4388 ("[pmc,%d] null pcd ri=%d", __LINE__, n)); 4389 (void) (*pcd->pcd_get_config)(cpu,adjri,&pm); 4390 4391 if (pm == NULL || /* !cfg'ed */ 4392 pm->pm_state != PMC_STATE_RUNNING || /* !active */ 4393 !PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)) || /* !sampling */ 4394 !CPU_ISSET(cpu, &pm->pm_cpustate) || /* !desired */ 4395 !CPU_ISSET(cpu, &pm->pm_stalled)) /* !stalled */ 4396 continue; 4397 4398 CPU_CLR_ATOMIC(cpu, &pm->pm_stalled); 4399 (*pcd->pcd_start_pmc)(cpu, adjri); 4400 } 4401 } 4402 4403 /* 4404 * Event handlers. 4405 */ 4406 4407 /* 4408 * Handle a process exit. 4409 * 4410 * Remove this process from all hash tables. If this process 4411 * owned any PMCs, turn off those PMCs and deallocate them, 4412 * removing any associations with target processes. 4413 * 4414 * This function will be called by the last 'thread' of a 4415 * process. 4416 * 4417 * XXX This eventhandler gets called early in the exit process. 4418 * Consider using a 'hook' invocation from thread_exit() or equivalent 4419 * spot. Another negative is that kse_exit doesn't seem to call 4420 * exit1() [??]. 4421 * 4422 */ 4423 4424 static void 4425 pmc_process_exit(void *arg __unused, struct proc *p) 4426 { 4427 struct pmc *pm; 4428 int adjri, cpu; 4429 unsigned int ri; 4430 int is_using_hwpmcs; 4431 struct pmc_owner *po; 4432 struct pmc_process *pp; 4433 struct pmc_classdep *pcd; 4434 pmc_value_t newvalue, tmp; 4435 4436 PROC_LOCK(p); 4437 is_using_hwpmcs = p->p_flag & P_HWPMC; 4438 PROC_UNLOCK(p); 4439 4440 /* 4441 * Log a sysexit event to all SS PMC owners. 4442 */ 4443 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 4444 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 4445 pmclog_process_sysexit(po, p->p_pid); 4446 4447 if (!is_using_hwpmcs) 4448 return; 4449 4450 PMC_GET_SX_XLOCK(); 4451 PMCDBG3(PRC,EXT,1,"process-exit proc=%p (%d, %s)", p, p->p_pid, 4452 p->p_comm); 4453 4454 /* 4455 * Since this code is invoked by the last thread in an exiting 4456 * process, we would have context switched IN at some prior 4457 * point. However, with PREEMPTION, kernel mode context 4458 * switches may happen any time, so we want to disable a 4459 * context switch OUT till we get any PMCs targeting this 4460 * process off the hardware. 4461 * 4462 * We also need to atomically remove this process' 4463 * entry from our target process hash table, using 4464 * PMC_FLAG_REMOVE. 4465 */ 4466 PMCDBG3(PRC,EXT,1, "process-exit proc=%p (%d, %s)", p, p->p_pid, 4467 p->p_comm); 4468 4469 critical_enter(); /* no preemption */ 4470 4471 cpu = curthread->td_oncpu; 4472 4473 if ((pp = pmc_find_process_descriptor(p, 4474 PMC_FLAG_REMOVE)) != NULL) { 4475 4476 PMCDBG2(PRC,EXT,2, 4477 "process-exit proc=%p pmc-process=%p", p, pp); 4478 4479 /* 4480 * The exiting process could the target of 4481 * some PMCs which will be running on 4482 * currently executing CPU. 4483 * 4484 * We need to turn these PMCs off like we 4485 * would do at context switch OUT time. 4486 */ 4487 for (ri = 0; ri < md->pmd_npmc; ri++) { 4488 4489 /* 4490 * Pick up the pmc pointer from hardware 4491 * state similar to the CSW_OUT code. 4492 */ 4493 pm = NULL; 4494 4495 pcd = pmc_ri_to_classdep(md, ri, &adjri); 4496 4497 (void) (*pcd->pcd_get_config)(cpu, adjri, &pm); 4498 4499 PMCDBG2(PRC,EXT,2, "ri=%d pm=%p", ri, pm); 4500 4501 if (pm == NULL || 4502 !PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) 4503 continue; 4504 4505 PMCDBG4(PRC,EXT,2, "ppmcs[%d]=%p pm=%p " 4506 "state=%d", ri, pp->pp_pmcs[ri].pp_pmc, 4507 pm, pm->pm_state); 4508 4509 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 4510 ("[pmc,%d] ri mismatch pmc(%d) ri(%d)", 4511 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 4512 4513 KASSERT(pm == pp->pp_pmcs[ri].pp_pmc, 4514 ("[pmc,%d] pm %p != pp_pmcs[%d] %p", 4515 __LINE__, pm, ri, pp->pp_pmcs[ri].pp_pmc)); 4516 4517 KASSERT(pm->pm_runcount > 0, 4518 ("[pmc,%d] bad runcount ri %d rc %d", 4519 __LINE__, ri, pm->pm_runcount)); 4520 4521 /* 4522 * Change desired state, and then stop if not 4523 * stalled. This two-step dance should avoid 4524 * race conditions where an interrupt re-enables 4525 * the PMC after this code has already checked 4526 * the pm_stalled flag. 4527 */ 4528 if (CPU_ISSET(cpu, &pm->pm_cpustate)) { 4529 CPU_CLR_ATOMIC(cpu, &pm->pm_cpustate); 4530 if (!CPU_ISSET(cpu, &pm->pm_stalled)) { 4531 (void) pcd->pcd_stop_pmc(cpu, adjri); 4532 pcd->pcd_read_pmc(cpu, adjri, 4533 &newvalue); 4534 tmp = newvalue - 4535 PMC_PCPU_SAVED(cpu,ri); 4536 4537 mtx_pool_lock_spin(pmc_mtxpool, pm); 4538 pm->pm_gv.pm_savedvalue += tmp; 4539 pp->pp_pmcs[ri].pp_pmcval += tmp; 4540 mtx_pool_unlock_spin(pmc_mtxpool, pm); 4541 } 4542 } 4543 4544 atomic_subtract_rel_int(&pm->pm_runcount,1); 4545 4546 KASSERT((int) pm->pm_runcount >= 0, 4547 ("[pmc,%d] runcount is %d", __LINE__, ri)); 4548 4549 (void) pcd->pcd_config_pmc(cpu, adjri, NULL); 4550 } 4551 4552 /* 4553 * Inform the MD layer of this pseudo "context switch 4554 * out" 4555 */ 4556 (void) md->pmd_switch_out(pmc_pcpu[cpu], pp); 4557 4558 critical_exit(); /* ok to be pre-empted now */ 4559 4560 /* 4561 * Unlink this process from the PMCs that are 4562 * targeting it. This will send a signal to 4563 * all PMC owner's whose PMCs are orphaned. 4564 * 4565 * Log PMC value at exit time if requested. 4566 */ 4567 for (ri = 0; ri < md->pmd_npmc; ri++) 4568 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) { 4569 if (pm->pm_flags & PMC_F_NEEDS_LOGFILE && 4570 PMC_IS_COUNTING_MODE(PMC_TO_MODE(pm))) 4571 pmclog_process_procexit(pm, pp); 4572 pmc_unlink_target_process(pm, pp); 4573 } 4574 free(pp, M_PMC); 4575 4576 } else 4577 critical_exit(); /* pp == NULL */ 4578 4579 4580 /* 4581 * If the process owned PMCs, free them up and free up 4582 * memory. 4583 */ 4584 if ((po = pmc_find_owner_descriptor(p)) != NULL) { 4585 pmc_remove_owner(po); 4586 pmc_destroy_owner_descriptor(po); 4587 } 4588 4589 sx_xunlock(&pmc_sx); 4590 } 4591 4592 /* 4593 * Handle a process fork. 4594 * 4595 * If the parent process 'p1' is under HWPMC monitoring, then copy 4596 * over any attached PMCs that have 'do_descendants' semantics. 4597 */ 4598 4599 static void 4600 pmc_process_fork(void *arg __unused, struct proc *p1, struct proc *newproc, 4601 int flags) 4602 { 4603 int is_using_hwpmcs; 4604 unsigned int ri; 4605 uint32_t do_descendants; 4606 struct pmc *pm; 4607 struct pmc_owner *po; 4608 struct pmc_process *ppnew, *ppold; 4609 4610 (void) flags; /* unused parameter */ 4611 4612 PROC_LOCK(p1); 4613 is_using_hwpmcs = p1->p_flag & P_HWPMC; 4614 PROC_UNLOCK(p1); 4615 4616 /* 4617 * If there are system-wide sampling PMCs active, we need to 4618 * log all fork events to their owner's logs. 4619 */ 4620 4621 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 4622 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 4623 pmclog_process_procfork(po, p1->p_pid, newproc->p_pid); 4624 4625 if (!is_using_hwpmcs) 4626 return; 4627 4628 PMC_GET_SX_XLOCK(); 4629 PMCDBG4(PMC,FRK,1, "process-fork proc=%p (%d, %s) -> %p", p1, 4630 p1->p_pid, p1->p_comm, newproc); 4631 4632 /* 4633 * If the parent process (curthread->td_proc) is a 4634 * target of any PMCs, look for PMCs that are to be 4635 * inherited, and link these into the new process 4636 * descriptor. 4637 */ 4638 if ((ppold = pmc_find_process_descriptor(curthread->td_proc, 4639 PMC_FLAG_NONE)) == NULL) 4640 goto done; /* nothing to do */ 4641 4642 do_descendants = 0; 4643 for (ri = 0; ri < md->pmd_npmc; ri++) 4644 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL) 4645 do_descendants |= pm->pm_flags & PMC_F_DESCENDANTS; 4646 if (do_descendants == 0) /* nothing to do */ 4647 goto done; 4648 4649 /* allocate a descriptor for the new process */ 4650 if ((ppnew = pmc_find_process_descriptor(newproc, 4651 PMC_FLAG_ALLOCATE)) == NULL) 4652 goto done; 4653 4654 /* 4655 * Run through all PMCs that were targeting the old process 4656 * and which specified F_DESCENDANTS and attach them to the 4657 * new process. 4658 * 4659 * Log the fork event to all owners of PMCs attached to this 4660 * process, if not already logged. 4661 */ 4662 for (ri = 0; ri < md->pmd_npmc; ri++) 4663 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL && 4664 (pm->pm_flags & PMC_F_DESCENDANTS)) { 4665 pmc_link_target_process(pm, ppnew); 4666 po = pm->pm_owner; 4667 if (po->po_sscount == 0 && 4668 po->po_flags & PMC_PO_OWNS_LOGFILE) 4669 pmclog_process_procfork(po, p1->p_pid, 4670 newproc->p_pid); 4671 } 4672 4673 /* 4674 * Now mark the new process as being tracked by this driver. 4675 */ 4676 PROC_LOCK(newproc); 4677 newproc->p_flag |= P_HWPMC; 4678 PROC_UNLOCK(newproc); 4679 4680 done: 4681 sx_xunlock(&pmc_sx); 4682 } 4683 4684 static void 4685 pmc_kld_load(void *arg __unused, linker_file_t lf) 4686 { 4687 struct pmc_owner *po; 4688 4689 sx_slock(&pmc_sx); 4690 4691 /* 4692 * Notify owners of system sampling PMCs about KLD operations. 4693 */ 4694 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 4695 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 4696 pmclog_process_map_in(po, (pid_t) -1, 4697 (uintfptr_t) lf->address, lf->filename); 4698 4699 /* 4700 * TODO: Notify owners of (all) process-sampling PMCs too. 4701 */ 4702 4703 sx_sunlock(&pmc_sx); 4704 } 4705 4706 static void 4707 pmc_kld_unload(void *arg __unused, const char *filename __unused, 4708 caddr_t address, size_t size) 4709 { 4710 struct pmc_owner *po; 4711 4712 sx_slock(&pmc_sx); 4713 4714 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 4715 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 4716 pmclog_process_map_out(po, (pid_t) -1, 4717 (uintfptr_t) address, (uintfptr_t) address + size); 4718 4719 /* 4720 * TODO: Notify owners of process-sampling PMCs. 4721 */ 4722 4723 sx_sunlock(&pmc_sx); 4724 } 4725 4726 /* 4727 * initialization 4728 */ 4729 static const char * 4730 pmc_name_of_pmcclass(enum pmc_class class) 4731 { 4732 4733 switch (class) { 4734 #undef __PMC_CLASS 4735 #define __PMC_CLASS(S,V,D) \ 4736 case PMC_CLASS_##S: \ 4737 return #S; 4738 __PMC_CLASSES(); 4739 default: 4740 return ("<unknown>"); 4741 } 4742 } 4743 4744 /* 4745 * Base class initializer: allocate structure and set default classes. 4746 */ 4747 struct pmc_mdep * 4748 pmc_mdep_alloc(int nclasses) 4749 { 4750 struct pmc_mdep *md; 4751 int n; 4752 4753 /* SOFT + md classes */ 4754 n = 1 + nclasses; 4755 md = malloc(sizeof(struct pmc_mdep) + n * 4756 sizeof(struct pmc_classdep), M_PMC, M_WAITOK|M_ZERO); 4757 md->pmd_nclass = n; 4758 4759 /* Add base class. */ 4760 pmc_soft_initialize(md); 4761 return md; 4762 } 4763 4764 void 4765 pmc_mdep_free(struct pmc_mdep *md) 4766 { 4767 pmc_soft_finalize(md); 4768 free(md, M_PMC); 4769 } 4770 4771 static int 4772 generic_switch_in(struct pmc_cpu *pc, struct pmc_process *pp) 4773 { 4774 (void) pc; (void) pp; 4775 4776 return (0); 4777 } 4778 4779 static int 4780 generic_switch_out(struct pmc_cpu *pc, struct pmc_process *pp) 4781 { 4782 (void) pc; (void) pp; 4783 4784 return (0); 4785 } 4786 4787 static struct pmc_mdep * 4788 pmc_generic_cpu_initialize(void) 4789 { 4790 struct pmc_mdep *md; 4791 4792 md = pmc_mdep_alloc(0); 4793 4794 md->pmd_cputype = PMC_CPU_GENERIC; 4795 4796 md->pmd_pcpu_init = NULL; 4797 md->pmd_pcpu_fini = NULL; 4798 md->pmd_switch_in = generic_switch_in; 4799 md->pmd_switch_out = generic_switch_out; 4800 4801 return (md); 4802 } 4803 4804 static void 4805 pmc_generic_cpu_finalize(struct pmc_mdep *md) 4806 { 4807 (void) md; 4808 } 4809 4810 4811 static int 4812 pmc_initialize(void) 4813 { 4814 int c, cpu, error, n, ri; 4815 unsigned int maxcpu; 4816 struct pmc_binding pb; 4817 struct pmc_sample *ps; 4818 struct pmc_classdep *pcd; 4819 struct pmc_samplebuffer *sb; 4820 4821 md = NULL; 4822 error = 0; 4823 4824 #ifdef HWPMC_DEBUG 4825 /* parse debug flags first */ 4826 if (TUNABLE_STR_FETCH(PMC_SYSCTL_NAME_PREFIX "debugflags", 4827 pmc_debugstr, sizeof(pmc_debugstr))) 4828 pmc_debugflags_parse(pmc_debugstr, 4829 pmc_debugstr+strlen(pmc_debugstr)); 4830 #endif 4831 4832 PMCDBG1(MOD,INI,0, "PMC Initialize (version %x)", PMC_VERSION); 4833 4834 /* check kernel version */ 4835 if (pmc_kernel_version != PMC_VERSION) { 4836 if (pmc_kernel_version == 0) 4837 printf("hwpmc: this kernel has not been compiled with " 4838 "'options HWPMC_HOOKS'.\n"); 4839 else 4840 printf("hwpmc: kernel version (0x%x) does not match " 4841 "module version (0x%x).\n", pmc_kernel_version, 4842 PMC_VERSION); 4843 return EPROGMISMATCH; 4844 } 4845 4846 /* 4847 * check sysctl parameters 4848 */ 4849 4850 if (pmc_hashsize <= 0) { 4851 (void) printf("hwpmc: tunable \"hashsize\"=%d must be " 4852 "greater than zero.\n", pmc_hashsize); 4853 pmc_hashsize = PMC_HASH_SIZE; 4854 } 4855 4856 if (pmc_nsamples <= 0 || pmc_nsamples > 65535) { 4857 (void) printf("hwpmc: tunable \"nsamples\"=%d out of " 4858 "range.\n", pmc_nsamples); 4859 pmc_nsamples = PMC_NSAMPLES; 4860 } 4861 4862 if (pmc_callchaindepth <= 0 || 4863 pmc_callchaindepth > PMC_CALLCHAIN_DEPTH_MAX) { 4864 (void) printf("hwpmc: tunable \"callchaindepth\"=%d out of " 4865 "range - using %d.\n", pmc_callchaindepth, 4866 PMC_CALLCHAIN_DEPTH_MAX); 4867 pmc_callchaindepth = PMC_CALLCHAIN_DEPTH_MAX; 4868 } 4869 4870 md = pmc_md_initialize(); 4871 if (md == NULL) { 4872 /* Default to generic CPU. */ 4873 md = pmc_generic_cpu_initialize(); 4874 if (md == NULL) 4875 return (ENOSYS); 4876 } 4877 4878 KASSERT(md->pmd_nclass >= 1 && md->pmd_npmc >= 1, 4879 ("[pmc,%d] no classes or pmcs", __LINE__)); 4880 4881 /* Compute the map from row-indices to classdep pointers. */ 4882 pmc_rowindex_to_classdep = malloc(sizeof(struct pmc_classdep *) * 4883 md->pmd_npmc, M_PMC, M_WAITOK|M_ZERO); 4884 4885 for (n = 0; n < md->pmd_npmc; n++) 4886 pmc_rowindex_to_classdep[n] = NULL; 4887 for (ri = c = 0; c < md->pmd_nclass; c++) { 4888 pcd = &md->pmd_classdep[c]; 4889 for (n = 0; n < pcd->pcd_num; n++, ri++) 4890 pmc_rowindex_to_classdep[ri] = pcd; 4891 } 4892 4893 KASSERT(ri == md->pmd_npmc, 4894 ("[pmc,%d] npmc miscomputed: ri=%d, md->npmc=%d", __LINE__, 4895 ri, md->pmd_npmc)); 4896 4897 maxcpu = pmc_cpu_max(); 4898 4899 /* allocate space for the per-cpu array */ 4900 pmc_pcpu = malloc(maxcpu * sizeof(struct pmc_cpu *), M_PMC, 4901 M_WAITOK|M_ZERO); 4902 4903 /* per-cpu 'saved values' for managing process-mode PMCs */ 4904 pmc_pcpu_saved = malloc(sizeof(pmc_value_t) * maxcpu * md->pmd_npmc, 4905 M_PMC, M_WAITOK); 4906 4907 /* Perform CPU-dependent initialization. */ 4908 pmc_save_cpu_binding(&pb); 4909 error = 0; 4910 for (cpu = 0; error == 0 && cpu < maxcpu; cpu++) { 4911 if (!pmc_cpu_is_active(cpu)) 4912 continue; 4913 pmc_select_cpu(cpu); 4914 pmc_pcpu[cpu] = malloc(sizeof(struct pmc_cpu) + 4915 md->pmd_npmc * sizeof(struct pmc_hw *), M_PMC, 4916 M_WAITOK|M_ZERO); 4917 if (md->pmd_pcpu_init) 4918 error = md->pmd_pcpu_init(md, cpu); 4919 for (n = 0; error == 0 && n < md->pmd_nclass; n++) 4920 error = md->pmd_classdep[n].pcd_pcpu_init(md, cpu); 4921 } 4922 pmc_restore_cpu_binding(&pb); 4923 4924 if (error) 4925 return (error); 4926 4927 /* allocate space for the sample array */ 4928 for (cpu = 0; cpu < maxcpu; cpu++) { 4929 if (!pmc_cpu_is_active(cpu)) 4930 continue; 4931 4932 sb = malloc(sizeof(struct pmc_samplebuffer) + 4933 pmc_nsamples * sizeof(struct pmc_sample), M_PMC, 4934 M_WAITOK|M_ZERO); 4935 sb->ps_read = sb->ps_write = sb->ps_samples; 4936 sb->ps_fence = sb->ps_samples + pmc_nsamples; 4937 4938 KASSERT(pmc_pcpu[cpu] != NULL, 4939 ("[pmc,%d] cpu=%d Null per-cpu data", __LINE__, cpu)); 4940 4941 sb->ps_callchains = malloc(pmc_callchaindepth * pmc_nsamples * 4942 sizeof(uintptr_t), M_PMC, M_WAITOK|M_ZERO); 4943 4944 for (n = 0, ps = sb->ps_samples; n < pmc_nsamples; n++, ps++) 4945 ps->ps_pc = sb->ps_callchains + 4946 (n * pmc_callchaindepth); 4947 4948 pmc_pcpu[cpu]->pc_sb[PMC_HR] = sb; 4949 4950 sb = malloc(sizeof(struct pmc_samplebuffer) + 4951 pmc_nsamples * sizeof(struct pmc_sample), M_PMC, 4952 M_WAITOK|M_ZERO); 4953 sb->ps_read = sb->ps_write = sb->ps_samples; 4954 sb->ps_fence = sb->ps_samples + pmc_nsamples; 4955 4956 KASSERT(pmc_pcpu[cpu] != NULL, 4957 ("[pmc,%d] cpu=%d Null per-cpu data", __LINE__, cpu)); 4958 4959 sb->ps_callchains = malloc(pmc_callchaindepth * pmc_nsamples * 4960 sizeof(uintptr_t), M_PMC, M_WAITOK|M_ZERO); 4961 4962 for (n = 0, ps = sb->ps_samples; n < pmc_nsamples; n++, ps++) 4963 ps->ps_pc = sb->ps_callchains + 4964 (n * pmc_callchaindepth); 4965 4966 pmc_pcpu[cpu]->pc_sb[PMC_SR] = sb; 4967 } 4968 4969 /* allocate space for the row disposition array */ 4970 pmc_pmcdisp = malloc(sizeof(enum pmc_mode) * md->pmd_npmc, 4971 M_PMC, M_WAITOK|M_ZERO); 4972 4973 /* mark all PMCs as available */ 4974 for (n = 0; n < (int) md->pmd_npmc; n++) 4975 PMC_MARK_ROW_FREE(n); 4976 4977 /* allocate thread hash tables */ 4978 pmc_ownerhash = hashinit(pmc_hashsize, M_PMC, 4979 &pmc_ownerhashmask); 4980 4981 pmc_processhash = hashinit(pmc_hashsize, M_PMC, 4982 &pmc_processhashmask); 4983 mtx_init(&pmc_processhash_mtx, "pmc-process-hash", "pmc-leaf", 4984 MTX_SPIN); 4985 4986 LIST_INIT(&pmc_ss_owners); 4987 pmc_ss_count = 0; 4988 4989 /* allocate a pool of spin mutexes */ 4990 pmc_mtxpool = mtx_pool_create("pmc-leaf", pmc_mtxpool_size, 4991 MTX_SPIN); 4992 4993 PMCDBG4(MOD,INI,1, "pmc_ownerhash=%p, mask=0x%lx " 4994 "targethash=%p mask=0x%lx", pmc_ownerhash, pmc_ownerhashmask, 4995 pmc_processhash, pmc_processhashmask); 4996 4997 /* register process {exit,fork,exec} handlers */ 4998 pmc_exit_tag = EVENTHANDLER_REGISTER(process_exit, 4999 pmc_process_exit, NULL, EVENTHANDLER_PRI_ANY); 5000 pmc_fork_tag = EVENTHANDLER_REGISTER(process_fork, 5001 pmc_process_fork, NULL, EVENTHANDLER_PRI_ANY); 5002 5003 /* register kld event handlers */ 5004 pmc_kld_load_tag = EVENTHANDLER_REGISTER(kld_load, pmc_kld_load, 5005 NULL, EVENTHANDLER_PRI_ANY); 5006 pmc_kld_unload_tag = EVENTHANDLER_REGISTER(kld_unload, pmc_kld_unload, 5007 NULL, EVENTHANDLER_PRI_ANY); 5008 5009 /* initialize logging */ 5010 pmclog_initialize(); 5011 5012 /* set hook functions */ 5013 pmc_intr = md->pmd_intr; 5014 pmc_hook = pmc_hook_handler; 5015 5016 if (error == 0) { 5017 printf(PMC_MODULE_NAME ":"); 5018 for (n = 0; n < (int) md->pmd_nclass; n++) { 5019 pcd = &md->pmd_classdep[n]; 5020 printf(" %s/%d/%d/0x%b", 5021 pmc_name_of_pmcclass(pcd->pcd_class), 5022 pcd->pcd_num, 5023 pcd->pcd_width, 5024 pcd->pcd_caps, 5025 "\20" 5026 "\1INT\2USR\3SYS\4EDG\5THR" 5027 "\6REA\7WRI\10INV\11QUA\12PRC" 5028 "\13TAG\14CSC"); 5029 } 5030 printf("\n"); 5031 } 5032 5033 return (error); 5034 } 5035 5036 /* prepare to be unloaded */ 5037 static void 5038 pmc_cleanup(void) 5039 { 5040 int c, cpu; 5041 unsigned int maxcpu; 5042 struct pmc_ownerhash *ph; 5043 struct pmc_owner *po, *tmp; 5044 struct pmc_binding pb; 5045 #ifdef HWPMC_DEBUG 5046 struct pmc_processhash *prh; 5047 #endif 5048 5049 PMCDBG0(MOD,INI,0, "cleanup"); 5050 5051 /* switch off sampling */ 5052 CPU_ZERO(&pmc_cpumask); 5053 pmc_intr = NULL; 5054 5055 sx_xlock(&pmc_sx); 5056 if (pmc_hook == NULL) { /* being unloaded already */ 5057 sx_xunlock(&pmc_sx); 5058 return; 5059 } 5060 5061 pmc_hook = NULL; /* prevent new threads from entering module */ 5062 5063 /* deregister event handlers */ 5064 EVENTHANDLER_DEREGISTER(process_fork, pmc_fork_tag); 5065 EVENTHANDLER_DEREGISTER(process_exit, pmc_exit_tag); 5066 EVENTHANDLER_DEREGISTER(kld_load, pmc_kld_load_tag); 5067 EVENTHANDLER_DEREGISTER(kld_unload, pmc_kld_unload_tag); 5068 5069 /* send SIGBUS to all owner threads, free up allocations */ 5070 if (pmc_ownerhash) 5071 for (ph = pmc_ownerhash; 5072 ph <= &pmc_ownerhash[pmc_ownerhashmask]; 5073 ph++) { 5074 LIST_FOREACH_SAFE(po, ph, po_next, tmp) { 5075 pmc_remove_owner(po); 5076 5077 /* send SIGBUS to owner processes */ 5078 PMCDBG3(MOD,INI,2, "cleanup signal proc=%p " 5079 "(%d, %s)", po->po_owner, 5080 po->po_owner->p_pid, 5081 po->po_owner->p_comm); 5082 5083 PROC_LOCK(po->po_owner); 5084 kern_psignal(po->po_owner, SIGBUS); 5085 PROC_UNLOCK(po->po_owner); 5086 5087 pmc_destroy_owner_descriptor(po); 5088 } 5089 } 5090 5091 /* reclaim allocated data structures */ 5092 if (pmc_mtxpool) 5093 mtx_pool_destroy(&pmc_mtxpool); 5094 5095 mtx_destroy(&pmc_processhash_mtx); 5096 if (pmc_processhash) { 5097 #ifdef HWPMC_DEBUG 5098 struct pmc_process *pp; 5099 5100 PMCDBG0(MOD,INI,3, "destroy process hash"); 5101 for (prh = pmc_processhash; 5102 prh <= &pmc_processhash[pmc_processhashmask]; 5103 prh++) 5104 LIST_FOREACH(pp, prh, pp_next) 5105 PMCDBG1(MOD,INI,3, "pid=%d", pp->pp_proc->p_pid); 5106 #endif 5107 5108 hashdestroy(pmc_processhash, M_PMC, pmc_processhashmask); 5109 pmc_processhash = NULL; 5110 } 5111 5112 if (pmc_ownerhash) { 5113 PMCDBG0(MOD,INI,3, "destroy owner hash"); 5114 hashdestroy(pmc_ownerhash, M_PMC, pmc_ownerhashmask); 5115 pmc_ownerhash = NULL; 5116 } 5117 5118 KASSERT(LIST_EMPTY(&pmc_ss_owners), 5119 ("[pmc,%d] Global SS owner list not empty", __LINE__)); 5120 KASSERT(pmc_ss_count == 0, 5121 ("[pmc,%d] Global SS count not empty", __LINE__)); 5122 5123 /* do processor and pmc-class dependent cleanup */ 5124 maxcpu = pmc_cpu_max(); 5125 5126 PMCDBG0(MOD,INI,3, "md cleanup"); 5127 if (md) { 5128 pmc_save_cpu_binding(&pb); 5129 for (cpu = 0; cpu < maxcpu; cpu++) { 5130 PMCDBG2(MOD,INI,1,"pmc-cleanup cpu=%d pcs=%p", 5131 cpu, pmc_pcpu[cpu]); 5132 if (!pmc_cpu_is_active(cpu) || pmc_pcpu[cpu] == NULL) 5133 continue; 5134 pmc_select_cpu(cpu); 5135 for (c = 0; c < md->pmd_nclass; c++) 5136 md->pmd_classdep[c].pcd_pcpu_fini(md, cpu); 5137 if (md->pmd_pcpu_fini) 5138 md->pmd_pcpu_fini(md, cpu); 5139 } 5140 5141 if (md->pmd_cputype == PMC_CPU_GENERIC) 5142 pmc_generic_cpu_finalize(md); 5143 else 5144 pmc_md_finalize(md); 5145 5146 pmc_mdep_free(md); 5147 md = NULL; 5148 pmc_restore_cpu_binding(&pb); 5149 } 5150 5151 /* Free per-cpu descriptors. */ 5152 for (cpu = 0; cpu < maxcpu; cpu++) { 5153 if (!pmc_cpu_is_active(cpu)) 5154 continue; 5155 KASSERT(pmc_pcpu[cpu]->pc_sb[PMC_HR] != NULL, 5156 ("[pmc,%d] Null hw cpu sample buffer cpu=%d", __LINE__, 5157 cpu)); 5158 KASSERT(pmc_pcpu[cpu]->pc_sb[PMC_SR] != NULL, 5159 ("[pmc,%d] Null sw cpu sample buffer cpu=%d", __LINE__, 5160 cpu)); 5161 free(pmc_pcpu[cpu]->pc_sb[PMC_HR]->ps_callchains, M_PMC); 5162 free(pmc_pcpu[cpu]->pc_sb[PMC_HR], M_PMC); 5163 free(pmc_pcpu[cpu]->pc_sb[PMC_SR]->ps_callchains, M_PMC); 5164 free(pmc_pcpu[cpu]->pc_sb[PMC_SR], M_PMC); 5165 free(pmc_pcpu[cpu], M_PMC); 5166 } 5167 5168 free(pmc_pcpu, M_PMC); 5169 pmc_pcpu = NULL; 5170 5171 free(pmc_pcpu_saved, M_PMC); 5172 pmc_pcpu_saved = NULL; 5173 5174 if (pmc_pmcdisp) { 5175 free(pmc_pmcdisp, M_PMC); 5176 pmc_pmcdisp = NULL; 5177 } 5178 5179 if (pmc_rowindex_to_classdep) { 5180 free(pmc_rowindex_to_classdep, M_PMC); 5181 pmc_rowindex_to_classdep = NULL; 5182 } 5183 5184 pmclog_shutdown(); 5185 5186 sx_xunlock(&pmc_sx); /* we are done */ 5187 } 5188 5189 /* 5190 * The function called at load/unload. 5191 */ 5192 5193 static int 5194 load (struct module *module __unused, int cmd, void *arg __unused) 5195 { 5196 int error; 5197 5198 error = 0; 5199 5200 switch (cmd) { 5201 case MOD_LOAD : 5202 /* initialize the subsystem */ 5203 error = pmc_initialize(); 5204 if (error != 0) 5205 break; 5206 PMCDBG2(MOD,INI,1, "syscall=%d maxcpu=%d", 5207 pmc_syscall_num, pmc_cpu_max()); 5208 break; 5209 5210 5211 case MOD_UNLOAD : 5212 case MOD_SHUTDOWN: 5213 pmc_cleanup(); 5214 PMCDBG0(MOD,INI,1, "unloaded"); 5215 break; 5216 5217 default : 5218 error = EINVAL; /* XXX should panic(9) */ 5219 break; 5220 } 5221 5222 return error; 5223 } 5224 5225 /* memory pool */ 5226 MALLOC_DEFINE(M_PMC, "pmc", "Memory space for the PMC module"); 5227