1 /*- 2 * Copyright (c) 2003-2008 Joseph Koshy 3 * Copyright (c) 2007 The FreeBSD Foundation 4 * All rights reserved. 5 * 6 * Portions of this software were developed by A. Joseph Koshy under 7 * sponsorship from the FreeBSD Foundation and Google, Inc. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 * 30 */ 31 32 #include <sys/cdefs.h> 33 __FBSDID("$FreeBSD$"); 34 35 #include <sys/param.h> 36 #include <sys/eventhandler.h> 37 #include <sys/jail.h> 38 #include <sys/kernel.h> 39 #include <sys/kthread.h> 40 #include <sys/limits.h> 41 #include <sys/lock.h> 42 #include <sys/malloc.h> 43 #include <sys/module.h> 44 #include <sys/mount.h> 45 #include <sys/mutex.h> 46 #include <sys/pmc.h> 47 #include <sys/pmckern.h> 48 #include <sys/pmclog.h> 49 #include <sys/priv.h> 50 #include <sys/proc.h> 51 #include <sys/queue.h> 52 #include <sys/resourcevar.h> 53 #include <sys/rwlock.h> 54 #include <sys/sched.h> 55 #include <sys/signalvar.h> 56 #include <sys/smp.h> 57 #include <sys/sx.h> 58 #include <sys/sysctl.h> 59 #include <sys/sysent.h> 60 #include <sys/systm.h> 61 #include <sys/vnode.h> 62 63 #include <sys/linker.h> /* needs to be after <sys/malloc.h> */ 64 65 #include <machine/atomic.h> 66 #include <machine/md_var.h> 67 68 #include <vm/vm.h> 69 #include <vm/vm_extern.h> 70 #include <vm/pmap.h> 71 #include <vm/vm_map.h> 72 #include <vm/vm_object.h> 73 74 #include "hwpmc_soft.h" 75 76 /* 77 * Types 78 */ 79 80 enum pmc_flags { 81 PMC_FLAG_NONE = 0x00, /* do nothing */ 82 PMC_FLAG_REMOVE = 0x01, /* atomically remove entry from hash */ 83 PMC_FLAG_ALLOCATE = 0x02, /* add entry to hash if not found */ 84 }; 85 86 /* 87 * The offset in sysent where the syscall is allocated. 88 */ 89 90 static int pmc_syscall_num = NO_SYSCALL; 91 struct pmc_cpu **pmc_pcpu; /* per-cpu state */ 92 pmc_value_t *pmc_pcpu_saved; /* saved PMC values: CSW handling */ 93 94 #define PMC_PCPU_SAVED(C,R) pmc_pcpu_saved[(R) + md->pmd_npmc*(C)] 95 96 struct mtx_pool *pmc_mtxpool; 97 static int *pmc_pmcdisp; /* PMC row dispositions */ 98 99 #define PMC_ROW_DISP_IS_FREE(R) (pmc_pmcdisp[(R)] == 0) 100 #define PMC_ROW_DISP_IS_THREAD(R) (pmc_pmcdisp[(R)] > 0) 101 #define PMC_ROW_DISP_IS_STANDALONE(R) (pmc_pmcdisp[(R)] < 0) 102 103 #define PMC_MARK_ROW_FREE(R) do { \ 104 pmc_pmcdisp[(R)] = 0; \ 105 } while (0) 106 107 #define PMC_MARK_ROW_STANDALONE(R) do { \ 108 KASSERT(pmc_pmcdisp[(R)] <= 0, ("[pmc,%d] row disposition error", \ 109 __LINE__)); \ 110 atomic_add_int(&pmc_pmcdisp[(R)], -1); \ 111 KASSERT(pmc_pmcdisp[(R)] >= (-pmc_cpu_max_active()), \ 112 ("[pmc,%d] row disposition error", __LINE__)); \ 113 } while (0) 114 115 #define PMC_UNMARK_ROW_STANDALONE(R) do { \ 116 atomic_add_int(&pmc_pmcdisp[(R)], 1); \ 117 KASSERT(pmc_pmcdisp[(R)] <= 0, ("[pmc,%d] row disposition error", \ 118 __LINE__)); \ 119 } while (0) 120 121 #define PMC_MARK_ROW_THREAD(R) do { \ 122 KASSERT(pmc_pmcdisp[(R)] >= 0, ("[pmc,%d] row disposition error", \ 123 __LINE__)); \ 124 atomic_add_int(&pmc_pmcdisp[(R)], 1); \ 125 } while (0) 126 127 #define PMC_UNMARK_ROW_THREAD(R) do { \ 128 atomic_add_int(&pmc_pmcdisp[(R)], -1); \ 129 KASSERT(pmc_pmcdisp[(R)] >= 0, ("[pmc,%d] row disposition error", \ 130 __LINE__)); \ 131 } while (0) 132 133 134 /* various event handlers */ 135 static eventhandler_tag pmc_exit_tag, pmc_fork_tag, pmc_kld_load_tag, 136 pmc_kld_unload_tag; 137 138 /* Module statistics */ 139 struct pmc_op_getdriverstats pmc_stats; 140 141 /* Machine/processor dependent operations */ 142 static struct pmc_mdep *md; 143 144 /* 145 * Hash tables mapping owner processes and target threads to PMCs. 146 */ 147 148 struct mtx pmc_processhash_mtx; /* spin mutex */ 149 static u_long pmc_processhashmask; 150 static LIST_HEAD(pmc_processhash, pmc_process) *pmc_processhash; 151 152 /* 153 * Hash table of PMC owner descriptors. This table is protected by 154 * the shared PMC "sx" lock. 155 */ 156 157 static u_long pmc_ownerhashmask; 158 static LIST_HEAD(pmc_ownerhash, pmc_owner) *pmc_ownerhash; 159 160 /* 161 * List of PMC owners with system-wide sampling PMCs. 162 */ 163 164 static LIST_HEAD(, pmc_owner) pmc_ss_owners; 165 166 167 /* 168 * A map of row indices to classdep structures. 169 */ 170 static struct pmc_classdep **pmc_rowindex_to_classdep; 171 172 /* 173 * Prototypes 174 */ 175 176 #ifdef HWPMC_DEBUG 177 static int pmc_debugflags_sysctl_handler(SYSCTL_HANDLER_ARGS); 178 static int pmc_debugflags_parse(char *newstr, char *fence); 179 #endif 180 181 static int load(struct module *module, int cmd, void *arg); 182 static int pmc_attach_process(struct proc *p, struct pmc *pm); 183 static struct pmc *pmc_allocate_pmc_descriptor(void); 184 static struct pmc_owner *pmc_allocate_owner_descriptor(struct proc *p); 185 static int pmc_attach_one_process(struct proc *p, struct pmc *pm); 186 static int pmc_can_allocate_rowindex(struct proc *p, unsigned int ri, 187 int cpu); 188 static int pmc_can_attach(struct pmc *pm, struct proc *p); 189 static void pmc_capture_user_callchain(int cpu, int soft, struct trapframe *tf); 190 static void pmc_cleanup(void); 191 static int pmc_detach_process(struct proc *p, struct pmc *pm); 192 static int pmc_detach_one_process(struct proc *p, struct pmc *pm, 193 int flags); 194 static void pmc_destroy_owner_descriptor(struct pmc_owner *po); 195 static void pmc_destroy_pmc_descriptor(struct pmc *pm); 196 static struct pmc_owner *pmc_find_owner_descriptor(struct proc *p); 197 static int pmc_find_pmc(pmc_id_t pmcid, struct pmc **pm); 198 static struct pmc *pmc_find_pmc_descriptor_in_process(struct pmc_owner *po, 199 pmc_id_t pmc); 200 static struct pmc_process *pmc_find_process_descriptor(struct proc *p, 201 uint32_t mode); 202 static void pmc_force_context_switch(void); 203 static void pmc_link_target_process(struct pmc *pm, 204 struct pmc_process *pp); 205 static void pmc_log_all_process_mappings(struct pmc_owner *po); 206 static void pmc_log_kernel_mappings(struct pmc *pm); 207 static void pmc_log_process_mappings(struct pmc_owner *po, struct proc *p); 208 static void pmc_maybe_remove_owner(struct pmc_owner *po); 209 static void pmc_process_csw_in(struct thread *td); 210 static void pmc_process_csw_out(struct thread *td); 211 static void pmc_process_exit(void *arg, struct proc *p); 212 static void pmc_process_fork(void *arg, struct proc *p1, 213 struct proc *p2, int n); 214 static void pmc_process_samples(int cpu, int soft); 215 static void pmc_release_pmc_descriptor(struct pmc *pmc); 216 static void pmc_remove_owner(struct pmc_owner *po); 217 static void pmc_remove_process_descriptor(struct pmc_process *pp); 218 static void pmc_restore_cpu_binding(struct pmc_binding *pb); 219 static void pmc_save_cpu_binding(struct pmc_binding *pb); 220 static void pmc_select_cpu(int cpu); 221 static int pmc_start(struct pmc *pm); 222 static int pmc_stop(struct pmc *pm); 223 static int pmc_syscall_handler(struct thread *td, void *syscall_args); 224 static void pmc_unlink_target_process(struct pmc *pmc, 225 struct pmc_process *pp); 226 static int generic_switch_in(struct pmc_cpu *pc, struct pmc_process *pp); 227 static int generic_switch_out(struct pmc_cpu *pc, struct pmc_process *pp); 228 static struct pmc_mdep *pmc_generic_cpu_initialize(void); 229 static void pmc_generic_cpu_finalize(struct pmc_mdep *md); 230 231 /* 232 * Kernel tunables and sysctl(8) interface. 233 */ 234 235 SYSCTL_DECL(_kern_hwpmc); 236 237 static int pmc_callchaindepth = PMC_CALLCHAIN_DEPTH; 238 SYSCTL_INT(_kern_hwpmc, OID_AUTO, callchaindepth, CTLFLAG_RDTUN, 239 &pmc_callchaindepth, 0, "depth of call chain records"); 240 241 #ifdef HWPMC_DEBUG 242 struct pmc_debugflags pmc_debugflags = PMC_DEBUG_DEFAULT_FLAGS; 243 char pmc_debugstr[PMC_DEBUG_STRSIZE]; 244 TUNABLE_STR(PMC_SYSCTL_NAME_PREFIX "debugflags", pmc_debugstr, 245 sizeof(pmc_debugstr)); 246 SYSCTL_PROC(_kern_hwpmc, OID_AUTO, debugflags, 247 CTLTYPE_STRING | CTLFLAG_RWTUN | CTLFLAG_NOFETCH, 248 0, 0, pmc_debugflags_sysctl_handler, "A", "debug flags"); 249 #endif 250 251 /* 252 * kern.hwpmc.hashrows -- determines the number of rows in the 253 * of the hash table used to look up threads 254 */ 255 256 static int pmc_hashsize = PMC_HASH_SIZE; 257 SYSCTL_INT(_kern_hwpmc, OID_AUTO, hashsize, CTLFLAG_RDTUN, 258 &pmc_hashsize, 0, "rows in hash tables"); 259 260 /* 261 * kern.hwpmc.nsamples --- number of PC samples/callchain stacks per CPU 262 */ 263 264 static int pmc_nsamples = PMC_NSAMPLES; 265 SYSCTL_INT(_kern_hwpmc, OID_AUTO, nsamples, CTLFLAG_RDTUN, 266 &pmc_nsamples, 0, "number of PC samples per CPU"); 267 268 269 /* 270 * kern.hwpmc.mtxpoolsize -- number of mutexes in the mutex pool. 271 */ 272 273 static int pmc_mtxpool_size = PMC_MTXPOOL_SIZE; 274 SYSCTL_INT(_kern_hwpmc, OID_AUTO, mtxpoolsize, CTLFLAG_RDTUN, 275 &pmc_mtxpool_size, 0, "size of spin mutex pool"); 276 277 278 /* 279 * security.bsd.unprivileged_syspmcs -- allow non-root processes to 280 * allocate system-wide PMCs. 281 * 282 * Allowing unprivileged processes to allocate system PMCs is convenient 283 * if system-wide measurements need to be taken concurrently with other 284 * per-process measurements. This feature is turned off by default. 285 */ 286 287 static int pmc_unprivileged_syspmcs = 0; 288 SYSCTL_INT(_security_bsd, OID_AUTO, unprivileged_syspmcs, CTLFLAG_RWTUN, 289 &pmc_unprivileged_syspmcs, 0, 290 "allow unprivileged process to allocate system PMCs"); 291 292 /* 293 * Hash function. Discard the lower 2 bits of the pointer since 294 * these are always zero for our uses. The hash multiplier is 295 * round((2^LONG_BIT) * ((sqrt(5)-1)/2)). 296 */ 297 298 #if LONG_BIT == 64 299 #define _PMC_HM 11400714819323198486u 300 #elif LONG_BIT == 32 301 #define _PMC_HM 2654435769u 302 #else 303 #error Must know the size of 'long' to compile 304 #endif 305 306 #define PMC_HASH_PTR(P,M) ((((unsigned long) (P) >> 2) * _PMC_HM) & (M)) 307 308 /* 309 * Syscall structures 310 */ 311 312 /* The `sysent' for the new syscall */ 313 static struct sysent pmc_sysent = { 314 2, /* sy_narg */ 315 pmc_syscall_handler /* sy_call */ 316 }; 317 318 static struct syscall_module_data pmc_syscall_mod = { 319 load, 320 NULL, 321 &pmc_syscall_num, 322 &pmc_sysent, 323 #if (__FreeBSD_version >= 1100000) 324 { 0, NULL }, 325 SY_THR_STATIC_KLD, 326 #else 327 { 0, NULL } 328 #endif 329 }; 330 331 static moduledata_t pmc_mod = { 332 PMC_MODULE_NAME, 333 syscall_module_handler, 334 &pmc_syscall_mod 335 }; 336 337 #ifdef EARLY_AP_STARTUP 338 DECLARE_MODULE(pmc, pmc_mod, SI_SUB_SYSCALLS, SI_ORDER_ANY); 339 #else 340 DECLARE_MODULE(pmc, pmc_mod, SI_SUB_SMP, SI_ORDER_ANY); 341 #endif 342 MODULE_VERSION(pmc, PMC_VERSION); 343 344 #ifdef HWPMC_DEBUG 345 enum pmc_dbgparse_state { 346 PMCDS_WS, /* in whitespace */ 347 PMCDS_MAJOR, /* seen a major keyword */ 348 PMCDS_MINOR 349 }; 350 351 static int 352 pmc_debugflags_parse(char *newstr, char *fence) 353 { 354 char c, *p, *q; 355 struct pmc_debugflags *tmpflags; 356 int error, found, *newbits, tmp; 357 size_t kwlen; 358 359 tmpflags = malloc(sizeof(*tmpflags), M_PMC, M_WAITOK|M_ZERO); 360 361 p = newstr; 362 error = 0; 363 364 for (; p < fence && (c = *p); p++) { 365 366 /* skip white space */ 367 if (c == ' ' || c == '\t') 368 continue; 369 370 /* look for a keyword followed by "=" */ 371 for (q = p; p < fence && (c = *p) && c != '='; p++) 372 ; 373 if (c != '=') { 374 error = EINVAL; 375 goto done; 376 } 377 378 kwlen = p - q; 379 newbits = NULL; 380 381 /* lookup flag group name */ 382 #define DBG_SET_FLAG_MAJ(S,F) \ 383 if (kwlen == sizeof(S)-1 && strncmp(q, S, kwlen) == 0) \ 384 newbits = &tmpflags->pdb_ ## F; 385 386 DBG_SET_FLAG_MAJ("cpu", CPU); 387 DBG_SET_FLAG_MAJ("csw", CSW); 388 DBG_SET_FLAG_MAJ("logging", LOG); 389 DBG_SET_FLAG_MAJ("module", MOD); 390 DBG_SET_FLAG_MAJ("md", MDP); 391 DBG_SET_FLAG_MAJ("owner", OWN); 392 DBG_SET_FLAG_MAJ("pmc", PMC); 393 DBG_SET_FLAG_MAJ("process", PRC); 394 DBG_SET_FLAG_MAJ("sampling", SAM); 395 396 if (newbits == NULL) { 397 error = EINVAL; 398 goto done; 399 } 400 401 p++; /* skip the '=' */ 402 403 /* Now parse the individual flags */ 404 tmp = 0; 405 newflag: 406 for (q = p; p < fence && (c = *p); p++) 407 if (c == ' ' || c == '\t' || c == ',') 408 break; 409 410 /* p == fence or c == ws or c == "," or c == 0 */ 411 412 if ((kwlen = p - q) == 0) { 413 *newbits = tmp; 414 continue; 415 } 416 417 found = 0; 418 #define DBG_SET_FLAG_MIN(S,F) \ 419 if (kwlen == sizeof(S)-1 && strncmp(q, S, kwlen) == 0) \ 420 tmp |= found = (1 << PMC_DEBUG_MIN_ ## F) 421 422 /* a '*' denotes all possible flags in the group */ 423 if (kwlen == 1 && *q == '*') 424 tmp = found = ~0; 425 /* look for individual flag names */ 426 DBG_SET_FLAG_MIN("allocaterow", ALR); 427 DBG_SET_FLAG_MIN("allocate", ALL); 428 DBG_SET_FLAG_MIN("attach", ATT); 429 DBG_SET_FLAG_MIN("bind", BND); 430 DBG_SET_FLAG_MIN("config", CFG); 431 DBG_SET_FLAG_MIN("exec", EXC); 432 DBG_SET_FLAG_MIN("exit", EXT); 433 DBG_SET_FLAG_MIN("find", FND); 434 DBG_SET_FLAG_MIN("flush", FLS); 435 DBG_SET_FLAG_MIN("fork", FRK); 436 DBG_SET_FLAG_MIN("getbuf", GTB); 437 DBG_SET_FLAG_MIN("hook", PMH); 438 DBG_SET_FLAG_MIN("init", INI); 439 DBG_SET_FLAG_MIN("intr", INT); 440 DBG_SET_FLAG_MIN("linktarget", TLK); 441 DBG_SET_FLAG_MIN("mayberemove", OMR); 442 DBG_SET_FLAG_MIN("ops", OPS); 443 DBG_SET_FLAG_MIN("read", REA); 444 DBG_SET_FLAG_MIN("register", REG); 445 DBG_SET_FLAG_MIN("release", REL); 446 DBG_SET_FLAG_MIN("remove", ORM); 447 DBG_SET_FLAG_MIN("sample", SAM); 448 DBG_SET_FLAG_MIN("scheduleio", SIO); 449 DBG_SET_FLAG_MIN("select", SEL); 450 DBG_SET_FLAG_MIN("signal", SIG); 451 DBG_SET_FLAG_MIN("swi", SWI); 452 DBG_SET_FLAG_MIN("swo", SWO); 453 DBG_SET_FLAG_MIN("start", STA); 454 DBG_SET_FLAG_MIN("stop", STO); 455 DBG_SET_FLAG_MIN("syscall", PMS); 456 DBG_SET_FLAG_MIN("unlinktarget", TUL); 457 DBG_SET_FLAG_MIN("write", WRI); 458 if (found == 0) { 459 /* unrecognized flag name */ 460 error = EINVAL; 461 goto done; 462 } 463 464 if (c == 0 || c == ' ' || c == '\t') { /* end of flag group */ 465 *newbits = tmp; 466 continue; 467 } 468 469 p++; 470 goto newflag; 471 } 472 473 /* save the new flag set */ 474 bcopy(tmpflags, &pmc_debugflags, sizeof(pmc_debugflags)); 475 476 done: 477 free(tmpflags, M_PMC); 478 return error; 479 } 480 481 static int 482 pmc_debugflags_sysctl_handler(SYSCTL_HANDLER_ARGS) 483 { 484 char *fence, *newstr; 485 int error; 486 unsigned int n; 487 488 (void) arg1; (void) arg2; /* unused parameters */ 489 490 n = sizeof(pmc_debugstr); 491 newstr = malloc(n, M_PMC, M_WAITOK|M_ZERO); 492 (void) strlcpy(newstr, pmc_debugstr, n); 493 494 error = sysctl_handle_string(oidp, newstr, n, req); 495 496 /* if there is a new string, parse and copy it */ 497 if (error == 0 && req->newptr != NULL) { 498 fence = newstr + (n < req->newlen ? n : req->newlen + 1); 499 if ((error = pmc_debugflags_parse(newstr, fence)) == 0) 500 (void) strlcpy(pmc_debugstr, newstr, 501 sizeof(pmc_debugstr)); 502 } 503 504 free(newstr, M_PMC); 505 506 return error; 507 } 508 #endif 509 510 /* 511 * Map a row index to a classdep structure and return the adjusted row 512 * index for the PMC class index. 513 */ 514 static struct pmc_classdep * 515 pmc_ri_to_classdep(struct pmc_mdep *md, int ri, int *adjri) 516 { 517 struct pmc_classdep *pcd; 518 519 (void) md; 520 521 KASSERT(ri >= 0 && ri < md->pmd_npmc, 522 ("[pmc,%d] illegal row-index %d", __LINE__, ri)); 523 524 pcd = pmc_rowindex_to_classdep[ri]; 525 526 KASSERT(pcd != NULL, 527 ("[pmc,%d] ri %d null pcd", __LINE__, ri)); 528 529 *adjri = ri - pcd->pcd_ri; 530 531 KASSERT(*adjri >= 0 && *adjri < pcd->pcd_num, 532 ("[pmc,%d] adjusted row-index %d", __LINE__, *adjri)); 533 534 return (pcd); 535 } 536 537 /* 538 * Concurrency Control 539 * 540 * The driver manages the following data structures: 541 * 542 * - target process descriptors, one per target process 543 * - owner process descriptors (and attached lists), one per owner process 544 * - lookup hash tables for owner and target processes 545 * - PMC descriptors (and attached lists) 546 * - per-cpu hardware state 547 * - the 'hook' variable through which the kernel calls into 548 * this module 549 * - the machine hardware state (managed by the MD layer) 550 * 551 * These data structures are accessed from: 552 * 553 * - thread context-switch code 554 * - interrupt handlers (possibly on multiple cpus) 555 * - kernel threads on multiple cpus running on behalf of user 556 * processes doing system calls 557 * - this driver's private kernel threads 558 * 559 * = Locks and Locking strategy = 560 * 561 * The driver uses four locking strategies for its operation: 562 * 563 * - The global SX lock "pmc_sx" is used to protect internal 564 * data structures. 565 * 566 * Calls into the module by syscall() start with this lock being 567 * held in exclusive mode. Depending on the requested operation, 568 * the lock may be downgraded to 'shared' mode to allow more 569 * concurrent readers into the module. Calls into the module from 570 * other parts of the kernel acquire the lock in shared mode. 571 * 572 * This SX lock is held in exclusive mode for any operations that 573 * modify the linkages between the driver's internal data structures. 574 * 575 * The 'pmc_hook' function pointer is also protected by this lock. 576 * It is only examined with the sx lock held in exclusive mode. The 577 * kernel module is allowed to be unloaded only with the sx lock held 578 * in exclusive mode. In normal syscall handling, after acquiring the 579 * pmc_sx lock we first check that 'pmc_hook' is non-null before 580 * proceeding. This prevents races between the thread unloading the module 581 * and other threads seeking to use the module. 582 * 583 * - Lookups of target process structures and owner process structures 584 * cannot use the global "pmc_sx" SX lock because these lookups need 585 * to happen during context switches and in other critical sections 586 * where sleeping is not allowed. We protect these lookup tables 587 * with their own private spin-mutexes, "pmc_processhash_mtx" and 588 * "pmc_ownerhash_mtx". 589 * 590 * - Interrupt handlers work in a lock free manner. At interrupt 591 * time, handlers look at the PMC pointer (phw->phw_pmc) configured 592 * when the PMC was started. If this pointer is NULL, the interrupt 593 * is ignored after updating driver statistics. We ensure that this 594 * pointer is set (using an atomic operation if necessary) before the 595 * PMC hardware is started. Conversely, this pointer is unset atomically 596 * only after the PMC hardware is stopped. 597 * 598 * We ensure that everything needed for the operation of an 599 * interrupt handler is available without it needing to acquire any 600 * locks. We also ensure that a PMC's software state is destroyed only 601 * after the PMC is taken off hardware (on all CPUs). 602 * 603 * - Context-switch handling with process-private PMCs needs more 604 * care. 605 * 606 * A given process may be the target of multiple PMCs. For example, 607 * PMCATTACH and PMCDETACH may be requested by a process on one CPU 608 * while the target process is running on another. A PMC could also 609 * be getting released because its owner is exiting. We tackle 610 * these situations in the following manner: 611 * 612 * - each target process structure 'pmc_process' has an array 613 * of 'struct pmc *' pointers, one for each hardware PMC. 614 * 615 * - At context switch IN time, each "target" PMC in RUNNING state 616 * gets started on hardware and a pointer to each PMC is copied into 617 * the per-cpu phw array. The 'runcount' for the PMC is 618 * incremented. 619 * 620 * - At context switch OUT time, all process-virtual PMCs are stopped 621 * on hardware. The saved value is added to the PMCs value field 622 * only if the PMC is in a non-deleted state (the PMCs state could 623 * have changed during the current time slice). 624 * 625 * Note that since in-between a switch IN on a processor and a switch 626 * OUT, the PMC could have been released on another CPU. Therefore 627 * context switch OUT always looks at the hardware state to turn 628 * OFF PMCs and will update a PMC's saved value only if reachable 629 * from the target process record. 630 * 631 * - OP PMCRELEASE could be called on a PMC at any time (the PMC could 632 * be attached to many processes at the time of the call and could 633 * be active on multiple CPUs). 634 * 635 * We prevent further scheduling of the PMC by marking it as in 636 * state 'DELETED'. If the runcount of the PMC is non-zero then 637 * this PMC is currently running on a CPU somewhere. The thread 638 * doing the PMCRELEASE operation waits by repeatedly doing a 639 * pause() till the runcount comes to zero. 640 * 641 * The contents of a PMC descriptor (struct pmc) are protected using 642 * a spin-mutex. In order to save space, we use a mutex pool. 643 * 644 * In terms of lock types used by witness(4), we use: 645 * - Type "pmc-sx", used by the global SX lock. 646 * - Type "pmc-sleep", for sleep mutexes used by logger threads. 647 * - Type "pmc-per-proc", for protecting PMC owner descriptors. 648 * - Type "pmc-leaf", used for all other spin mutexes. 649 */ 650 651 /* 652 * save the cpu binding of the current kthread 653 */ 654 655 static void 656 pmc_save_cpu_binding(struct pmc_binding *pb) 657 { 658 PMCDBG0(CPU,BND,2, "save-cpu"); 659 thread_lock(curthread); 660 pb->pb_bound = sched_is_bound(curthread); 661 pb->pb_cpu = curthread->td_oncpu; 662 thread_unlock(curthread); 663 PMCDBG1(CPU,BND,2, "save-cpu cpu=%d", pb->pb_cpu); 664 } 665 666 /* 667 * restore the cpu binding of the current thread 668 */ 669 670 static void 671 pmc_restore_cpu_binding(struct pmc_binding *pb) 672 { 673 PMCDBG2(CPU,BND,2, "restore-cpu curcpu=%d restore=%d", 674 curthread->td_oncpu, pb->pb_cpu); 675 thread_lock(curthread); 676 if (pb->pb_bound) 677 sched_bind(curthread, pb->pb_cpu); 678 else 679 sched_unbind(curthread); 680 thread_unlock(curthread); 681 PMCDBG0(CPU,BND,2, "restore-cpu done"); 682 } 683 684 /* 685 * move execution over the specified cpu and bind it there. 686 */ 687 688 static void 689 pmc_select_cpu(int cpu) 690 { 691 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 692 ("[pmc,%d] bad cpu number %d", __LINE__, cpu)); 693 694 /* Never move to an inactive CPU. */ 695 KASSERT(pmc_cpu_is_active(cpu), ("[pmc,%d] selecting inactive " 696 "CPU %d", __LINE__, cpu)); 697 698 PMCDBG1(CPU,SEL,2, "select-cpu cpu=%d", cpu); 699 thread_lock(curthread); 700 sched_bind(curthread, cpu); 701 thread_unlock(curthread); 702 703 KASSERT(curthread->td_oncpu == cpu, 704 ("[pmc,%d] CPU not bound [cpu=%d, curr=%d]", __LINE__, 705 cpu, curthread->td_oncpu)); 706 707 PMCDBG1(CPU,SEL,2, "select-cpu cpu=%d ok", cpu); 708 } 709 710 /* 711 * Force a context switch. 712 * 713 * We do this by pause'ing for 1 tick -- invoking mi_switch() is not 714 * guaranteed to force a context switch. 715 */ 716 717 static void 718 pmc_force_context_switch(void) 719 { 720 721 pause("pmcctx", 1); 722 } 723 724 /* 725 * Get the file name for an executable. This is a simple wrapper 726 * around vn_fullpath(9). 727 */ 728 729 static void 730 pmc_getfilename(struct vnode *v, char **fullpath, char **freepath) 731 { 732 733 *fullpath = "unknown"; 734 *freepath = NULL; 735 vn_fullpath(curthread, v, fullpath, freepath); 736 } 737 738 /* 739 * remove an process owning PMCs 740 */ 741 742 void 743 pmc_remove_owner(struct pmc_owner *po) 744 { 745 struct pmc *pm, *tmp; 746 747 sx_assert(&pmc_sx, SX_XLOCKED); 748 749 PMCDBG1(OWN,ORM,1, "remove-owner po=%p", po); 750 751 /* Remove descriptor from the owner hash table */ 752 LIST_REMOVE(po, po_next); 753 754 /* release all owned PMC descriptors */ 755 LIST_FOREACH_SAFE(pm, &po->po_pmcs, pm_next, tmp) { 756 PMCDBG1(OWN,ORM,2, "pmc=%p", pm); 757 KASSERT(pm->pm_owner == po, 758 ("[pmc,%d] owner %p != po %p", __LINE__, pm->pm_owner, po)); 759 760 pmc_release_pmc_descriptor(pm); /* will unlink from the list */ 761 pmc_destroy_pmc_descriptor(pm); 762 } 763 764 KASSERT(po->po_sscount == 0, 765 ("[pmc,%d] SS count not zero", __LINE__)); 766 KASSERT(LIST_EMPTY(&po->po_pmcs), 767 ("[pmc,%d] PMC list not empty", __LINE__)); 768 769 /* de-configure the log file if present */ 770 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 771 pmclog_deconfigure_log(po); 772 } 773 774 /* 775 * remove an owner process record if all conditions are met. 776 */ 777 778 static void 779 pmc_maybe_remove_owner(struct pmc_owner *po) 780 { 781 782 PMCDBG1(OWN,OMR,1, "maybe-remove-owner po=%p", po); 783 784 /* 785 * Remove owner record if 786 * - this process does not own any PMCs 787 * - this process has not allocated a system-wide sampling buffer 788 */ 789 790 if (LIST_EMPTY(&po->po_pmcs) && 791 ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0)) { 792 pmc_remove_owner(po); 793 pmc_destroy_owner_descriptor(po); 794 } 795 } 796 797 /* 798 * Add an association between a target process and a PMC. 799 */ 800 801 static void 802 pmc_link_target_process(struct pmc *pm, struct pmc_process *pp) 803 { 804 int ri; 805 struct pmc_target *pt; 806 807 sx_assert(&pmc_sx, SX_XLOCKED); 808 809 KASSERT(pm != NULL && pp != NULL, 810 ("[pmc,%d] Null pm %p or pp %p", __LINE__, pm, pp)); 811 KASSERT(PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)), 812 ("[pmc,%d] Attaching a non-process-virtual pmc=%p to pid=%d", 813 __LINE__, pm, pp->pp_proc->p_pid)); 814 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= ((int) md->pmd_npmc - 1), 815 ("[pmc,%d] Illegal reference count %d for process record %p", 816 __LINE__, pp->pp_refcnt, (void *) pp)); 817 818 ri = PMC_TO_ROWINDEX(pm); 819 820 PMCDBG3(PRC,TLK,1, "link-target pmc=%p ri=%d pmc-process=%p", 821 pm, ri, pp); 822 823 #ifdef HWPMC_DEBUG 824 LIST_FOREACH(pt, &pm->pm_targets, pt_next) 825 if (pt->pt_process == pp) 826 KASSERT(0, ("[pmc,%d] pp %p already in pmc %p targets", 827 __LINE__, pp, pm)); 828 #endif 829 830 pt = malloc(sizeof(struct pmc_target), M_PMC, M_WAITOK|M_ZERO); 831 pt->pt_process = pp; 832 833 LIST_INSERT_HEAD(&pm->pm_targets, pt, pt_next); 834 835 atomic_store_rel_ptr((uintptr_t *)&pp->pp_pmcs[ri].pp_pmc, 836 (uintptr_t)pm); 837 838 if (pm->pm_owner->po_owner == pp->pp_proc) 839 pm->pm_flags |= PMC_F_ATTACHED_TO_OWNER; 840 841 /* 842 * Initialize the per-process values at this row index. 843 */ 844 pp->pp_pmcs[ri].pp_pmcval = PMC_TO_MODE(pm) == PMC_MODE_TS ? 845 pm->pm_sc.pm_reloadcount : 0; 846 847 pp->pp_refcnt++; 848 849 } 850 851 /* 852 * Removes the association between a target process and a PMC. 853 */ 854 855 static void 856 pmc_unlink_target_process(struct pmc *pm, struct pmc_process *pp) 857 { 858 int ri; 859 struct proc *p; 860 struct pmc_target *ptgt; 861 862 sx_assert(&pmc_sx, SX_XLOCKED); 863 864 KASSERT(pm != NULL && pp != NULL, 865 ("[pmc,%d] Null pm %p or pp %p", __LINE__, pm, pp)); 866 867 KASSERT(pp->pp_refcnt >= 1 && pp->pp_refcnt <= (int) md->pmd_npmc, 868 ("[pmc,%d] Illegal ref count %d on process record %p", 869 __LINE__, pp->pp_refcnt, (void *) pp)); 870 871 ri = PMC_TO_ROWINDEX(pm); 872 873 PMCDBG3(PRC,TUL,1, "unlink-target pmc=%p ri=%d pmc-process=%p", 874 pm, ri, pp); 875 876 KASSERT(pp->pp_pmcs[ri].pp_pmc == pm, 877 ("[pmc,%d] PMC ri %d mismatch pmc %p pp->[ri] %p", __LINE__, 878 ri, pm, pp->pp_pmcs[ri].pp_pmc)); 879 880 pp->pp_pmcs[ri].pp_pmc = NULL; 881 pp->pp_pmcs[ri].pp_pmcval = (pmc_value_t) 0; 882 883 /* Remove owner-specific flags */ 884 if (pm->pm_owner->po_owner == pp->pp_proc) { 885 pp->pp_flags &= ~PMC_PP_ENABLE_MSR_ACCESS; 886 pm->pm_flags &= ~PMC_F_ATTACHED_TO_OWNER; 887 } 888 889 pp->pp_refcnt--; 890 891 /* Remove the target process from the PMC structure */ 892 LIST_FOREACH(ptgt, &pm->pm_targets, pt_next) 893 if (ptgt->pt_process == pp) 894 break; 895 896 KASSERT(ptgt != NULL, ("[pmc,%d] process %p (pp: %p) not found " 897 "in pmc %p", __LINE__, pp->pp_proc, pp, pm)); 898 899 LIST_REMOVE(ptgt, pt_next); 900 free(ptgt, M_PMC); 901 902 /* if the PMC now lacks targets, send the owner a SIGIO */ 903 if (LIST_EMPTY(&pm->pm_targets)) { 904 p = pm->pm_owner->po_owner; 905 PROC_LOCK(p); 906 kern_psignal(p, SIGIO); 907 PROC_UNLOCK(p); 908 909 PMCDBG2(PRC,SIG,2, "signalling proc=%p signal=%d", p, 910 SIGIO); 911 } 912 } 913 914 /* 915 * Check if PMC 'pm' may be attached to target process 't'. 916 */ 917 918 static int 919 pmc_can_attach(struct pmc *pm, struct proc *t) 920 { 921 struct proc *o; /* pmc owner */ 922 struct ucred *oc, *tc; /* owner, target credentials */ 923 int decline_attach, i; 924 925 /* 926 * A PMC's owner can always attach that PMC to itself. 927 */ 928 929 if ((o = pm->pm_owner->po_owner) == t) 930 return 0; 931 932 PROC_LOCK(o); 933 oc = o->p_ucred; 934 crhold(oc); 935 PROC_UNLOCK(o); 936 937 PROC_LOCK(t); 938 tc = t->p_ucred; 939 crhold(tc); 940 PROC_UNLOCK(t); 941 942 /* 943 * The effective uid of the PMC owner should match at least one 944 * of the {effective,real,saved} uids of the target process. 945 */ 946 947 decline_attach = oc->cr_uid != tc->cr_uid && 948 oc->cr_uid != tc->cr_svuid && 949 oc->cr_uid != tc->cr_ruid; 950 951 /* 952 * Every one of the target's group ids, must be in the owner's 953 * group list. 954 */ 955 for (i = 0; !decline_attach && i < tc->cr_ngroups; i++) 956 decline_attach = !groupmember(tc->cr_groups[i], oc); 957 958 /* check the read and saved gids too */ 959 if (decline_attach == 0) 960 decline_attach = !groupmember(tc->cr_rgid, oc) || 961 !groupmember(tc->cr_svgid, oc); 962 963 crfree(tc); 964 crfree(oc); 965 966 return !decline_attach; 967 } 968 969 /* 970 * Attach a process to a PMC. 971 */ 972 973 static int 974 pmc_attach_one_process(struct proc *p, struct pmc *pm) 975 { 976 int ri; 977 char *fullpath, *freepath; 978 struct pmc_process *pp; 979 980 sx_assert(&pmc_sx, SX_XLOCKED); 981 982 PMCDBG5(PRC,ATT,2, "attach-one pm=%p ri=%d proc=%p (%d, %s)", pm, 983 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 984 985 /* 986 * Locate the process descriptor corresponding to process 'p', 987 * allocating space as needed. 988 * 989 * Verify that rowindex 'pm_rowindex' is free in the process 990 * descriptor. 991 * 992 * If not, allocate space for a descriptor and link the 993 * process descriptor and PMC. 994 */ 995 ri = PMC_TO_ROWINDEX(pm); 996 997 if ((pp = pmc_find_process_descriptor(p, PMC_FLAG_ALLOCATE)) == NULL) 998 return ENOMEM; 999 1000 if (pp->pp_pmcs[ri].pp_pmc == pm) /* already present at slot [ri] */ 1001 return EEXIST; 1002 1003 if (pp->pp_pmcs[ri].pp_pmc != NULL) 1004 return EBUSY; 1005 1006 pmc_link_target_process(pm, pp); 1007 1008 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)) && 1009 (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) == 0) 1010 pm->pm_flags |= PMC_F_NEEDS_LOGFILE; 1011 1012 pm->pm_flags |= PMC_F_ATTACH_DONE; /* mark as attached */ 1013 1014 /* issue an attach event to a configured log file */ 1015 if (pm->pm_owner->po_flags & PMC_PO_OWNS_LOGFILE) { 1016 if (p->p_flag & P_KPROC) { 1017 fullpath = kernelname; 1018 freepath = NULL; 1019 } else { 1020 pmc_getfilename(p->p_textvp, &fullpath, &freepath); 1021 pmclog_process_pmcattach(pm, p->p_pid, fullpath); 1022 } 1023 free(freepath, M_TEMP); 1024 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 1025 pmc_log_process_mappings(pm->pm_owner, p); 1026 } 1027 /* mark process as using HWPMCs */ 1028 PROC_LOCK(p); 1029 p->p_flag |= P_HWPMC; 1030 PROC_UNLOCK(p); 1031 1032 return 0; 1033 } 1034 1035 /* 1036 * Attach a process and optionally its children 1037 */ 1038 1039 static int 1040 pmc_attach_process(struct proc *p, struct pmc *pm) 1041 { 1042 int error; 1043 struct proc *top; 1044 1045 sx_assert(&pmc_sx, SX_XLOCKED); 1046 1047 PMCDBG5(PRC,ATT,1, "attach pm=%p ri=%d proc=%p (%d, %s)", pm, 1048 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 1049 1050 1051 /* 1052 * If this PMC successfully allowed a GETMSR operation 1053 * in the past, disallow further ATTACHes. 1054 */ 1055 1056 if ((pm->pm_flags & PMC_PP_ENABLE_MSR_ACCESS) != 0) 1057 return EPERM; 1058 1059 if ((pm->pm_flags & PMC_F_DESCENDANTS) == 0) 1060 return pmc_attach_one_process(p, pm); 1061 1062 /* 1063 * Traverse all child processes, attaching them to 1064 * this PMC. 1065 */ 1066 1067 sx_slock(&proctree_lock); 1068 1069 top = p; 1070 1071 for (;;) { 1072 if ((error = pmc_attach_one_process(p, pm)) != 0) 1073 break; 1074 if (!LIST_EMPTY(&p->p_children)) 1075 p = LIST_FIRST(&p->p_children); 1076 else for (;;) { 1077 if (p == top) 1078 goto done; 1079 if (LIST_NEXT(p, p_sibling)) { 1080 p = LIST_NEXT(p, p_sibling); 1081 break; 1082 } 1083 p = p->p_pptr; 1084 } 1085 } 1086 1087 if (error) 1088 (void) pmc_detach_process(top, pm); 1089 1090 done: 1091 sx_sunlock(&proctree_lock); 1092 return error; 1093 } 1094 1095 /* 1096 * Detach a process from a PMC. If there are no other PMCs tracking 1097 * this process, remove the process structure from its hash table. If 1098 * 'flags' contains PMC_FLAG_REMOVE, then free the process structure. 1099 */ 1100 1101 static int 1102 pmc_detach_one_process(struct proc *p, struct pmc *pm, int flags) 1103 { 1104 int ri; 1105 struct pmc_process *pp; 1106 1107 sx_assert(&pmc_sx, SX_XLOCKED); 1108 1109 KASSERT(pm != NULL, 1110 ("[pmc,%d] null pm pointer", __LINE__)); 1111 1112 ri = PMC_TO_ROWINDEX(pm); 1113 1114 PMCDBG6(PRC,ATT,2, "detach-one pm=%p ri=%d proc=%p (%d, %s) flags=0x%x", 1115 pm, ri, p, p->p_pid, p->p_comm, flags); 1116 1117 if ((pp = pmc_find_process_descriptor(p, 0)) == NULL) 1118 return ESRCH; 1119 1120 if (pp->pp_pmcs[ri].pp_pmc != pm) 1121 return EINVAL; 1122 1123 pmc_unlink_target_process(pm, pp); 1124 1125 /* Issue a detach entry if a log file is configured */ 1126 if (pm->pm_owner->po_flags & PMC_PO_OWNS_LOGFILE) 1127 pmclog_process_pmcdetach(pm, p->p_pid); 1128 1129 /* 1130 * If there are no PMCs targeting this process, we remove its 1131 * descriptor from the target hash table and unset the P_HWPMC 1132 * flag in the struct proc. 1133 */ 1134 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= (int) md->pmd_npmc, 1135 ("[pmc,%d] Illegal refcnt %d for process struct %p", 1136 __LINE__, pp->pp_refcnt, pp)); 1137 1138 if (pp->pp_refcnt != 0) /* still a target of some PMC */ 1139 return 0; 1140 1141 pmc_remove_process_descriptor(pp); 1142 1143 if (flags & PMC_FLAG_REMOVE) 1144 free(pp, M_PMC); 1145 1146 PROC_LOCK(p); 1147 p->p_flag &= ~P_HWPMC; 1148 PROC_UNLOCK(p); 1149 1150 return 0; 1151 } 1152 1153 /* 1154 * Detach a process and optionally its descendants from a PMC. 1155 */ 1156 1157 static int 1158 pmc_detach_process(struct proc *p, struct pmc *pm) 1159 { 1160 struct proc *top; 1161 1162 sx_assert(&pmc_sx, SX_XLOCKED); 1163 1164 PMCDBG5(PRC,ATT,1, "detach pm=%p ri=%d proc=%p (%d, %s)", pm, 1165 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 1166 1167 if ((pm->pm_flags & PMC_F_DESCENDANTS) == 0) 1168 return pmc_detach_one_process(p, pm, PMC_FLAG_REMOVE); 1169 1170 /* 1171 * Traverse all children, detaching them from this PMC. We 1172 * ignore errors since we could be detaching a PMC from a 1173 * partially attached proc tree. 1174 */ 1175 1176 sx_slock(&proctree_lock); 1177 1178 top = p; 1179 1180 for (;;) { 1181 (void) pmc_detach_one_process(p, pm, PMC_FLAG_REMOVE); 1182 1183 if (!LIST_EMPTY(&p->p_children)) 1184 p = LIST_FIRST(&p->p_children); 1185 else for (;;) { 1186 if (p == top) 1187 goto done; 1188 if (LIST_NEXT(p, p_sibling)) { 1189 p = LIST_NEXT(p, p_sibling); 1190 break; 1191 } 1192 p = p->p_pptr; 1193 } 1194 } 1195 1196 done: 1197 sx_sunlock(&proctree_lock); 1198 1199 if (LIST_EMPTY(&pm->pm_targets)) 1200 pm->pm_flags &= ~PMC_F_ATTACH_DONE; 1201 1202 return 0; 1203 } 1204 1205 1206 /* 1207 * Thread context switch IN 1208 */ 1209 1210 static void 1211 pmc_process_csw_in(struct thread *td) 1212 { 1213 int cpu; 1214 unsigned int adjri, ri; 1215 struct pmc *pm; 1216 struct proc *p; 1217 struct pmc_cpu *pc; 1218 struct pmc_hw *phw; 1219 pmc_value_t newvalue; 1220 struct pmc_process *pp; 1221 struct pmc_classdep *pcd; 1222 1223 p = td->td_proc; 1224 1225 if ((pp = pmc_find_process_descriptor(p, PMC_FLAG_NONE)) == NULL) 1226 return; 1227 1228 KASSERT(pp->pp_proc == td->td_proc, 1229 ("[pmc,%d] not my thread state", __LINE__)); 1230 1231 critical_enter(); /* no preemption from this point */ 1232 1233 cpu = PCPU_GET(cpuid); /* td->td_oncpu is invalid */ 1234 1235 PMCDBG5(CSW,SWI,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p, 1236 p->p_pid, p->p_comm, pp); 1237 1238 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 1239 ("[pmc,%d] weird CPU id %d", __LINE__, cpu)); 1240 1241 pc = pmc_pcpu[cpu]; 1242 1243 for (ri = 0; ri < md->pmd_npmc; ri++) { 1244 1245 if ((pm = pp->pp_pmcs[ri].pp_pmc) == NULL) 1246 continue; 1247 1248 KASSERT(PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)), 1249 ("[pmc,%d] Target PMC in non-virtual mode (%d)", 1250 __LINE__, PMC_TO_MODE(pm))); 1251 1252 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 1253 ("[pmc,%d] Row index mismatch pmc %d != ri %d", 1254 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 1255 1256 /* 1257 * Only PMCs that are marked as 'RUNNING' need 1258 * be placed on hardware. 1259 */ 1260 1261 if (pm->pm_state != PMC_STATE_RUNNING) 1262 continue; 1263 1264 /* increment PMC runcount */ 1265 atomic_add_rel_int(&pm->pm_runcount, 1); 1266 1267 /* configure the HWPMC we are going to use. */ 1268 pcd = pmc_ri_to_classdep(md, ri, &adjri); 1269 pcd->pcd_config_pmc(cpu, adjri, pm); 1270 1271 phw = pc->pc_hwpmcs[ri]; 1272 1273 KASSERT(phw != NULL, 1274 ("[pmc,%d] null hw pointer", __LINE__)); 1275 1276 KASSERT(phw->phw_pmc == pm, 1277 ("[pmc,%d] hw->pmc %p != pmc %p", __LINE__, 1278 phw->phw_pmc, pm)); 1279 1280 /* 1281 * Write out saved value and start the PMC. 1282 * 1283 * Sampling PMCs use a per-process value, while 1284 * counting mode PMCs use a per-pmc value that is 1285 * inherited across descendants. 1286 */ 1287 if (PMC_TO_MODE(pm) == PMC_MODE_TS) { 1288 mtx_pool_lock_spin(pmc_mtxpool, pm); 1289 1290 /* 1291 * Use the saved value calculated after the most recent 1292 * thread switch out to start this counter. Reset 1293 * the saved count in case another thread from this 1294 * process switches in before any threads switch out. 1295 */ 1296 newvalue = PMC_PCPU_SAVED(cpu,ri) = 1297 pp->pp_pmcs[ri].pp_pmcval; 1298 pp->pp_pmcs[ri].pp_pmcval = pm->pm_sc.pm_reloadcount; 1299 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1300 } else { 1301 KASSERT(PMC_TO_MODE(pm) == PMC_MODE_TC, 1302 ("[pmc,%d] illegal mode=%d", __LINE__, 1303 PMC_TO_MODE(pm))); 1304 mtx_pool_lock_spin(pmc_mtxpool, pm); 1305 newvalue = PMC_PCPU_SAVED(cpu, ri) = 1306 pm->pm_gv.pm_savedvalue; 1307 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1308 } 1309 1310 PMCDBG3(CSW,SWI,1,"cpu=%d ri=%d new=%jd", cpu, ri, newvalue); 1311 1312 pcd->pcd_write_pmc(cpu, adjri, newvalue); 1313 1314 /* If a sampling mode PMC, reset stalled state. */ 1315 if (PMC_TO_MODE(pm) == PMC_MODE_TS) 1316 CPU_CLR_ATOMIC(cpu, &pm->pm_stalled); 1317 1318 /* Indicate that we desire this to run. */ 1319 CPU_SET_ATOMIC(cpu, &pm->pm_cpustate); 1320 1321 /* Start the PMC. */ 1322 pcd->pcd_start_pmc(cpu, adjri); 1323 } 1324 1325 /* 1326 * perform any other architecture/cpu dependent thread 1327 * switch-in actions. 1328 */ 1329 1330 (void) (*md->pmd_switch_in)(pc, pp); 1331 1332 critical_exit(); 1333 1334 } 1335 1336 /* 1337 * Thread context switch OUT. 1338 */ 1339 1340 static void 1341 pmc_process_csw_out(struct thread *td) 1342 { 1343 int cpu; 1344 int64_t tmp; 1345 struct pmc *pm; 1346 struct proc *p; 1347 enum pmc_mode mode; 1348 struct pmc_cpu *pc; 1349 pmc_value_t newvalue; 1350 unsigned int adjri, ri; 1351 struct pmc_process *pp; 1352 struct pmc_classdep *pcd; 1353 1354 1355 /* 1356 * Locate our process descriptor; this may be NULL if 1357 * this process is exiting and we have already removed 1358 * the process from the target process table. 1359 * 1360 * Note that due to kernel preemption, multiple 1361 * context switches may happen while the process is 1362 * exiting. 1363 * 1364 * Note also that if the target process cannot be 1365 * found we still need to deconfigure any PMCs that 1366 * are currently running on hardware. 1367 */ 1368 1369 p = td->td_proc; 1370 pp = pmc_find_process_descriptor(p, PMC_FLAG_NONE); 1371 1372 /* 1373 * save PMCs 1374 */ 1375 1376 critical_enter(); 1377 1378 cpu = PCPU_GET(cpuid); /* td->td_oncpu is invalid */ 1379 1380 PMCDBG5(CSW,SWO,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p, 1381 p->p_pid, p->p_comm, pp); 1382 1383 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 1384 ("[pmc,%d weird CPU id %d", __LINE__, cpu)); 1385 1386 pc = pmc_pcpu[cpu]; 1387 1388 /* 1389 * When a PMC gets unlinked from a target PMC, it will 1390 * be removed from the target's pp_pmc[] array. 1391 * 1392 * However, on a MP system, the target could have been 1393 * executing on another CPU at the time of the unlink. 1394 * So, at context switch OUT time, we need to look at 1395 * the hardware to determine if a PMC is scheduled on 1396 * it. 1397 */ 1398 1399 for (ri = 0; ri < md->pmd_npmc; ri++) { 1400 1401 pcd = pmc_ri_to_classdep(md, ri, &adjri); 1402 pm = NULL; 1403 (void) (*pcd->pcd_get_config)(cpu, adjri, &pm); 1404 1405 if (pm == NULL) /* nothing at this row index */ 1406 continue; 1407 1408 mode = PMC_TO_MODE(pm); 1409 if (!PMC_IS_VIRTUAL_MODE(mode)) 1410 continue; /* not a process virtual PMC */ 1411 1412 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 1413 ("[pmc,%d] ri mismatch pmc(%d) ri(%d)", 1414 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 1415 1416 /* 1417 * Change desired state, and then stop if not stalled. 1418 * This two-step dance should avoid race conditions where 1419 * an interrupt re-enables the PMC after this code has 1420 * already checked the pm_stalled flag. 1421 */ 1422 CPU_CLR_ATOMIC(cpu, &pm->pm_cpustate); 1423 if (!CPU_ISSET(cpu, &pm->pm_stalled)) 1424 pcd->pcd_stop_pmc(cpu, adjri); 1425 1426 /* reduce this PMC's runcount */ 1427 atomic_subtract_rel_int(&pm->pm_runcount, 1); 1428 1429 /* 1430 * If this PMC is associated with this process, 1431 * save the reading. 1432 */ 1433 1434 if (pp != NULL && pp->pp_pmcs[ri].pp_pmc != NULL) { 1435 1436 KASSERT(pm == pp->pp_pmcs[ri].pp_pmc, 1437 ("[pmc,%d] pm %p != pp_pmcs[%d] %p", __LINE__, 1438 pm, ri, pp->pp_pmcs[ri].pp_pmc)); 1439 1440 KASSERT(pp->pp_refcnt > 0, 1441 ("[pmc,%d] pp refcnt = %d", __LINE__, 1442 pp->pp_refcnt)); 1443 1444 pcd->pcd_read_pmc(cpu, adjri, &newvalue); 1445 1446 if (mode == PMC_MODE_TS) { 1447 PMCDBG3(CSW,SWO,1,"cpu=%d ri=%d tmp=%jd (samp)", 1448 cpu, ri, PMC_PCPU_SAVED(cpu,ri) - newvalue); 1449 1450 /* 1451 * For sampling process-virtual PMCs, 1452 * newvalue is the number of events to be seen 1453 * until the next sampling interrupt. 1454 * We can just add the events left from this 1455 * invocation to the counter, then adjust 1456 * in case we overflow our range. 1457 * 1458 * (Recall that we reload the counter every 1459 * time we use it.) 1460 */ 1461 mtx_pool_lock_spin(pmc_mtxpool, pm); 1462 1463 pp->pp_pmcs[ri].pp_pmcval += newvalue; 1464 if (pp->pp_pmcs[ri].pp_pmcval > 1465 pm->pm_sc.pm_reloadcount) 1466 pp->pp_pmcs[ri].pp_pmcval -= 1467 pm->pm_sc.pm_reloadcount; 1468 KASSERT(pp->pp_pmcs[ri].pp_pmcval > 0 && 1469 pp->pp_pmcs[ri].pp_pmcval <= 1470 pm->pm_sc.pm_reloadcount, 1471 ("[pmc,%d] pp_pmcval outside of expected " 1472 "range cpu=%d ri=%d pp_pmcval=%jx " 1473 "pm_reloadcount=%jx", __LINE__, cpu, ri, 1474 pp->pp_pmcs[ri].pp_pmcval, 1475 pm->pm_sc.pm_reloadcount)); 1476 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1477 1478 } else { 1479 tmp = newvalue - PMC_PCPU_SAVED(cpu,ri); 1480 1481 PMCDBG3(CSW,SWO,1,"cpu=%d ri=%d tmp=%jd (count)", 1482 cpu, ri, tmp); 1483 1484 /* 1485 * For counting process-virtual PMCs, 1486 * we expect the count to be 1487 * increasing monotonically, modulo a 64 1488 * bit wraparound. 1489 */ 1490 KASSERT(tmp >= 0, 1491 ("[pmc,%d] negative increment cpu=%d " 1492 "ri=%d newvalue=%jx saved=%jx " 1493 "incr=%jx", __LINE__, cpu, ri, 1494 newvalue, PMC_PCPU_SAVED(cpu,ri), tmp)); 1495 1496 mtx_pool_lock_spin(pmc_mtxpool, pm); 1497 pm->pm_gv.pm_savedvalue += tmp; 1498 pp->pp_pmcs[ri].pp_pmcval += tmp; 1499 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1500 1501 if (pm->pm_flags & PMC_F_LOG_PROCCSW) 1502 pmclog_process_proccsw(pm, pp, tmp); 1503 } 1504 } 1505 1506 /* mark hardware as free */ 1507 pcd->pcd_config_pmc(cpu, adjri, NULL); 1508 } 1509 1510 /* 1511 * perform any other architecture/cpu dependent thread 1512 * switch out functions. 1513 */ 1514 1515 (void) (*md->pmd_switch_out)(pc, pp); 1516 1517 critical_exit(); 1518 } 1519 1520 /* 1521 * A mapping change for a process. 1522 */ 1523 1524 static void 1525 pmc_process_mmap(struct thread *td, struct pmckern_map_in *pkm) 1526 { 1527 int ri; 1528 pid_t pid; 1529 char *fullpath, *freepath; 1530 const struct pmc *pm; 1531 struct pmc_owner *po; 1532 const struct pmc_process *pp; 1533 1534 freepath = fullpath = NULL; 1535 pmc_getfilename((struct vnode *) pkm->pm_file, &fullpath, &freepath); 1536 1537 pid = td->td_proc->p_pid; 1538 1539 /* Inform owners of all system-wide sampling PMCs. */ 1540 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1541 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1542 pmclog_process_map_in(po, pid, pkm->pm_address, fullpath); 1543 1544 if ((pp = pmc_find_process_descriptor(td->td_proc, 0)) == NULL) 1545 goto done; 1546 1547 /* 1548 * Inform sampling PMC owners tracking this process. 1549 */ 1550 for (ri = 0; ri < md->pmd_npmc; ri++) 1551 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL && 1552 PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 1553 pmclog_process_map_in(pm->pm_owner, 1554 pid, pkm->pm_address, fullpath); 1555 1556 done: 1557 if (freepath) 1558 free(freepath, M_TEMP); 1559 } 1560 1561 1562 /* 1563 * Log an munmap request. 1564 */ 1565 1566 static void 1567 pmc_process_munmap(struct thread *td, struct pmckern_map_out *pkm) 1568 { 1569 int ri; 1570 pid_t pid; 1571 struct pmc_owner *po; 1572 const struct pmc *pm; 1573 const struct pmc_process *pp; 1574 1575 pid = td->td_proc->p_pid; 1576 1577 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1578 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1579 pmclog_process_map_out(po, pid, pkm->pm_address, 1580 pkm->pm_address + pkm->pm_size); 1581 1582 if ((pp = pmc_find_process_descriptor(td->td_proc, 0)) == NULL) 1583 return; 1584 1585 for (ri = 0; ri < md->pmd_npmc; ri++) 1586 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL && 1587 PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 1588 pmclog_process_map_out(pm->pm_owner, pid, 1589 pkm->pm_address, pkm->pm_address + pkm->pm_size); 1590 } 1591 1592 /* 1593 * Log mapping information about the kernel. 1594 */ 1595 1596 static void 1597 pmc_log_kernel_mappings(struct pmc *pm) 1598 { 1599 struct pmc_owner *po; 1600 struct pmckern_map_in *km, *kmbase; 1601 1602 sx_assert(&pmc_sx, SX_LOCKED); 1603 KASSERT(PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)), 1604 ("[pmc,%d] non-sampling PMC (%p) desires mapping information", 1605 __LINE__, (void *) pm)); 1606 1607 po = pm->pm_owner; 1608 1609 if (po->po_flags & PMC_PO_INITIAL_MAPPINGS_DONE) 1610 return; 1611 1612 /* 1613 * Log the current set of kernel modules. 1614 */ 1615 kmbase = linker_hwpmc_list_objects(); 1616 for (km = kmbase; km->pm_file != NULL; km++) { 1617 PMCDBG2(LOG,REG,1,"%s %p", (char *) km->pm_file, 1618 (void *) km->pm_address); 1619 pmclog_process_map_in(po, (pid_t) -1, km->pm_address, 1620 km->pm_file); 1621 } 1622 free(kmbase, M_LINKER); 1623 1624 po->po_flags |= PMC_PO_INITIAL_MAPPINGS_DONE; 1625 } 1626 1627 /* 1628 * Log the mappings for a single process. 1629 */ 1630 1631 static void 1632 pmc_log_process_mappings(struct pmc_owner *po, struct proc *p) 1633 { 1634 vm_map_t map; 1635 struct vnode *vp; 1636 struct vmspace *vm; 1637 vm_map_entry_t entry; 1638 vm_offset_t last_end; 1639 u_int last_timestamp; 1640 struct vnode *last_vp; 1641 vm_offset_t start_addr; 1642 vm_object_t obj, lobj, tobj; 1643 char *fullpath, *freepath; 1644 1645 last_vp = NULL; 1646 last_end = (vm_offset_t) 0; 1647 fullpath = freepath = NULL; 1648 1649 if ((vm = vmspace_acquire_ref(p)) == NULL) 1650 return; 1651 1652 map = &vm->vm_map; 1653 vm_map_lock_read(map); 1654 1655 for (entry = map->header.next; entry != &map->header; entry = entry->next) { 1656 1657 if (entry == NULL) { 1658 PMCDBG2(LOG,OPS,2, "hwpmc: vm_map entry unexpectedly " 1659 "NULL! pid=%d vm_map=%p\n", p->p_pid, map); 1660 break; 1661 } 1662 1663 /* 1664 * We only care about executable map entries. 1665 */ 1666 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) || 1667 !(entry->protection & VM_PROT_EXECUTE) || 1668 (entry->object.vm_object == NULL)) { 1669 continue; 1670 } 1671 1672 obj = entry->object.vm_object; 1673 VM_OBJECT_RLOCK(obj); 1674 1675 /* 1676 * Walk the backing_object list to find the base 1677 * (non-shadowed) vm_object. 1678 */ 1679 for (lobj = tobj = obj; tobj != NULL; tobj = tobj->backing_object) { 1680 if (tobj != obj) 1681 VM_OBJECT_RLOCK(tobj); 1682 if (lobj != obj) 1683 VM_OBJECT_RUNLOCK(lobj); 1684 lobj = tobj; 1685 } 1686 1687 /* 1688 * At this point lobj is the base vm_object and it is locked. 1689 */ 1690 if (lobj == NULL) { 1691 PMCDBG3(LOG,OPS,2, "hwpmc: lobj unexpectedly NULL! pid=%d " 1692 "vm_map=%p vm_obj=%p\n", p->p_pid, map, obj); 1693 VM_OBJECT_RUNLOCK(obj); 1694 continue; 1695 } 1696 1697 vp = vm_object_vnode(lobj); 1698 if (vp == NULL) { 1699 if (lobj != obj) 1700 VM_OBJECT_RUNLOCK(lobj); 1701 VM_OBJECT_RUNLOCK(obj); 1702 continue; 1703 } 1704 1705 /* 1706 * Skip contiguous regions that point to the same 1707 * vnode, so we don't emit redundant MAP-IN 1708 * directives. 1709 */ 1710 if (entry->start == last_end && vp == last_vp) { 1711 last_end = entry->end; 1712 if (lobj != obj) 1713 VM_OBJECT_RUNLOCK(lobj); 1714 VM_OBJECT_RUNLOCK(obj); 1715 continue; 1716 } 1717 1718 /* 1719 * We don't want to keep the proc's vm_map or this 1720 * vm_object locked while we walk the pathname, since 1721 * vn_fullpath() can sleep. However, if we drop the 1722 * lock, it's possible for concurrent activity to 1723 * modify the vm_map list. To protect against this, 1724 * we save the vm_map timestamp before we release the 1725 * lock, and check it after we reacquire the lock 1726 * below. 1727 */ 1728 start_addr = entry->start; 1729 last_end = entry->end; 1730 last_timestamp = map->timestamp; 1731 vm_map_unlock_read(map); 1732 1733 vref(vp); 1734 if (lobj != obj) 1735 VM_OBJECT_RUNLOCK(lobj); 1736 1737 VM_OBJECT_RUNLOCK(obj); 1738 1739 freepath = NULL; 1740 pmc_getfilename(vp, &fullpath, &freepath); 1741 last_vp = vp; 1742 1743 vrele(vp); 1744 1745 vp = NULL; 1746 pmclog_process_map_in(po, p->p_pid, start_addr, fullpath); 1747 if (freepath) 1748 free(freepath, M_TEMP); 1749 1750 vm_map_lock_read(map); 1751 1752 /* 1753 * If our saved timestamp doesn't match, this means 1754 * that the vm_map was modified out from under us and 1755 * we can't trust our current "entry" pointer. Do a 1756 * new lookup for this entry. If there is no entry 1757 * for this address range, vm_map_lookup_entry() will 1758 * return the previous one, so we always want to go to 1759 * entry->next on the next loop iteration. 1760 * 1761 * There is an edge condition here that can occur if 1762 * there is no entry at or before this address. In 1763 * this situation, vm_map_lookup_entry returns 1764 * &map->header, which would cause our loop to abort 1765 * without processing the rest of the map. However, 1766 * in practice this will never happen for process 1767 * vm_map. This is because the executable's text 1768 * segment is the first mapping in the proc's address 1769 * space, and this mapping is never removed until the 1770 * process exits, so there will always be a non-header 1771 * entry at or before the requested address for 1772 * vm_map_lookup_entry to return. 1773 */ 1774 if (map->timestamp != last_timestamp) 1775 vm_map_lookup_entry(map, last_end - 1, &entry); 1776 } 1777 1778 vm_map_unlock_read(map); 1779 vmspace_free(vm); 1780 return; 1781 } 1782 1783 /* 1784 * Log mappings for all processes in the system. 1785 */ 1786 1787 static void 1788 pmc_log_all_process_mappings(struct pmc_owner *po) 1789 { 1790 struct proc *p, *top; 1791 1792 sx_assert(&pmc_sx, SX_XLOCKED); 1793 1794 if ((p = pfind(1)) == NULL) 1795 panic("[pmc,%d] Cannot find init", __LINE__); 1796 1797 PROC_UNLOCK(p); 1798 1799 sx_slock(&proctree_lock); 1800 1801 top = p; 1802 1803 for (;;) { 1804 pmc_log_process_mappings(po, p); 1805 if (!LIST_EMPTY(&p->p_children)) 1806 p = LIST_FIRST(&p->p_children); 1807 else for (;;) { 1808 if (p == top) 1809 goto done; 1810 if (LIST_NEXT(p, p_sibling)) { 1811 p = LIST_NEXT(p, p_sibling); 1812 break; 1813 } 1814 p = p->p_pptr; 1815 } 1816 } 1817 done: 1818 sx_sunlock(&proctree_lock); 1819 } 1820 1821 /* 1822 * The 'hook' invoked from the kernel proper 1823 */ 1824 1825 1826 #ifdef HWPMC_DEBUG 1827 const char *pmc_hooknames[] = { 1828 /* these strings correspond to PMC_FN_* in <sys/pmckern.h> */ 1829 "", 1830 "EXEC", 1831 "CSW-IN", 1832 "CSW-OUT", 1833 "SAMPLE", 1834 "UNUSED1", 1835 "UNUSED2", 1836 "MMAP", 1837 "MUNMAP", 1838 "CALLCHAIN-NMI", 1839 "CALLCHAIN-SOFT", 1840 "SOFTSAMPLING" 1841 }; 1842 #endif 1843 1844 static int 1845 pmc_hook_handler(struct thread *td, int function, void *arg) 1846 { 1847 1848 PMCDBG4(MOD,PMH,1, "hook td=%p func=%d \"%s\" arg=%p", td, function, 1849 pmc_hooknames[function], arg); 1850 1851 switch (function) 1852 { 1853 1854 /* 1855 * Process exec() 1856 */ 1857 1858 case PMC_FN_PROCESS_EXEC: 1859 { 1860 char *fullpath, *freepath; 1861 unsigned int ri; 1862 int is_using_hwpmcs; 1863 struct pmc *pm; 1864 struct proc *p; 1865 struct pmc_owner *po; 1866 struct pmc_process *pp; 1867 struct pmckern_procexec *pk; 1868 1869 sx_assert(&pmc_sx, SX_XLOCKED); 1870 1871 p = td->td_proc; 1872 pmc_getfilename(p->p_textvp, &fullpath, &freepath); 1873 1874 pk = (struct pmckern_procexec *) arg; 1875 1876 /* Inform owners of SS mode PMCs of the exec event. */ 1877 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1878 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1879 pmclog_process_procexec(po, PMC_ID_INVALID, 1880 p->p_pid, pk->pm_entryaddr, fullpath); 1881 1882 PROC_LOCK(p); 1883 is_using_hwpmcs = p->p_flag & P_HWPMC; 1884 PROC_UNLOCK(p); 1885 1886 if (!is_using_hwpmcs) { 1887 if (freepath) 1888 free(freepath, M_TEMP); 1889 break; 1890 } 1891 1892 /* 1893 * PMCs are not inherited across an exec(): remove any 1894 * PMCs that this process is the owner of. 1895 */ 1896 1897 if ((po = pmc_find_owner_descriptor(p)) != NULL) { 1898 pmc_remove_owner(po); 1899 pmc_destroy_owner_descriptor(po); 1900 } 1901 1902 /* 1903 * If the process being exec'ed is not the target of any 1904 * PMC, we are done. 1905 */ 1906 if ((pp = pmc_find_process_descriptor(p, 0)) == NULL) { 1907 if (freepath) 1908 free(freepath, M_TEMP); 1909 break; 1910 } 1911 1912 /* 1913 * Log the exec event to all monitoring owners. Skip 1914 * owners who have already received the event because 1915 * they had system sampling PMCs active. 1916 */ 1917 for (ri = 0; ri < md->pmd_npmc; ri++) 1918 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) { 1919 po = pm->pm_owner; 1920 if (po->po_sscount == 0 && 1921 po->po_flags & PMC_PO_OWNS_LOGFILE) 1922 pmclog_process_procexec(po, pm->pm_id, 1923 p->p_pid, pk->pm_entryaddr, 1924 fullpath); 1925 } 1926 1927 if (freepath) 1928 free(freepath, M_TEMP); 1929 1930 1931 PMCDBG4(PRC,EXC,1, "exec proc=%p (%d, %s) cred-changed=%d", 1932 p, p->p_pid, p->p_comm, pk->pm_credentialschanged); 1933 1934 if (pk->pm_credentialschanged == 0) /* no change */ 1935 break; 1936 1937 /* 1938 * If the newly exec()'ed process has a different credential 1939 * than before, allow it to be the target of a PMC only if 1940 * the PMC's owner has sufficient privilege. 1941 */ 1942 1943 for (ri = 0; ri < md->pmd_npmc; ri++) 1944 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) 1945 if (pmc_can_attach(pm, td->td_proc) != 0) 1946 pmc_detach_one_process(td->td_proc, 1947 pm, PMC_FLAG_NONE); 1948 1949 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= (int) md->pmd_npmc, 1950 ("[pmc,%d] Illegal ref count %d on pp %p", __LINE__, 1951 pp->pp_refcnt, pp)); 1952 1953 /* 1954 * If this process is no longer the target of any 1955 * PMCs, we can remove the process entry and free 1956 * up space. 1957 */ 1958 1959 if (pp->pp_refcnt == 0) { 1960 pmc_remove_process_descriptor(pp); 1961 free(pp, M_PMC); 1962 break; 1963 } 1964 1965 } 1966 break; 1967 1968 case PMC_FN_CSW_IN: 1969 pmc_process_csw_in(td); 1970 break; 1971 1972 case PMC_FN_CSW_OUT: 1973 pmc_process_csw_out(td); 1974 break; 1975 1976 /* 1977 * Process accumulated PC samples. 1978 * 1979 * This function is expected to be called by hardclock() for 1980 * each CPU that has accumulated PC samples. 1981 * 1982 * This function is to be executed on the CPU whose samples 1983 * are being processed. 1984 */ 1985 case PMC_FN_DO_SAMPLES: 1986 1987 /* 1988 * Clear the cpu specific bit in the CPU mask before 1989 * do the rest of the processing. If the NMI handler 1990 * gets invoked after the "atomic_clear_int()" call 1991 * below but before "pmc_process_samples()" gets 1992 * around to processing the interrupt, then we will 1993 * come back here at the next hardclock() tick (and 1994 * may find nothing to do if "pmc_process_samples()" 1995 * had already processed the interrupt). We don't 1996 * lose the interrupt sample. 1997 */ 1998 CPU_CLR_ATOMIC(PCPU_GET(cpuid), &pmc_cpumask); 1999 pmc_process_samples(PCPU_GET(cpuid), PMC_HR); 2000 pmc_process_samples(PCPU_GET(cpuid), PMC_SR); 2001 break; 2002 2003 case PMC_FN_MMAP: 2004 sx_assert(&pmc_sx, SX_LOCKED); 2005 pmc_process_mmap(td, (struct pmckern_map_in *) arg); 2006 break; 2007 2008 case PMC_FN_MUNMAP: 2009 sx_assert(&pmc_sx, SX_LOCKED); 2010 pmc_process_munmap(td, (struct pmckern_map_out *) arg); 2011 break; 2012 2013 case PMC_FN_USER_CALLCHAIN: 2014 /* 2015 * Record a call chain. 2016 */ 2017 KASSERT(td == curthread, ("[pmc,%d] td != curthread", 2018 __LINE__)); 2019 2020 pmc_capture_user_callchain(PCPU_GET(cpuid), PMC_HR, 2021 (struct trapframe *) arg); 2022 td->td_pflags &= ~TDP_CALLCHAIN; 2023 break; 2024 2025 case PMC_FN_USER_CALLCHAIN_SOFT: 2026 /* 2027 * Record a call chain. 2028 */ 2029 KASSERT(td == curthread, ("[pmc,%d] td != curthread", 2030 __LINE__)); 2031 pmc_capture_user_callchain(PCPU_GET(cpuid), PMC_SR, 2032 (struct trapframe *) arg); 2033 td->td_pflags &= ~TDP_CALLCHAIN; 2034 break; 2035 2036 case PMC_FN_SOFT_SAMPLING: 2037 /* 2038 * Call soft PMC sampling intr. 2039 */ 2040 pmc_soft_intr((struct pmckern_soft *) arg); 2041 break; 2042 2043 default: 2044 #ifdef HWPMC_DEBUG 2045 KASSERT(0, ("[pmc,%d] unknown hook %d\n", __LINE__, function)); 2046 #endif 2047 break; 2048 2049 } 2050 2051 return 0; 2052 } 2053 2054 /* 2055 * allocate a 'struct pmc_owner' descriptor in the owner hash table. 2056 */ 2057 2058 static struct pmc_owner * 2059 pmc_allocate_owner_descriptor(struct proc *p) 2060 { 2061 uint32_t hindex; 2062 struct pmc_owner *po; 2063 struct pmc_ownerhash *poh; 2064 2065 hindex = PMC_HASH_PTR(p, pmc_ownerhashmask); 2066 poh = &pmc_ownerhash[hindex]; 2067 2068 /* allocate space for N pointers and one descriptor struct */ 2069 po = malloc(sizeof(struct pmc_owner), M_PMC, M_WAITOK|M_ZERO); 2070 po->po_owner = p; 2071 LIST_INSERT_HEAD(poh, po, po_next); /* insert into hash table */ 2072 2073 TAILQ_INIT(&po->po_logbuffers); 2074 mtx_init(&po->po_mtx, "pmc-owner-mtx", "pmc-per-proc", MTX_SPIN); 2075 2076 PMCDBG4(OWN,ALL,1, "allocate-owner proc=%p (%d, %s) pmc-owner=%p", 2077 p, p->p_pid, p->p_comm, po); 2078 2079 return po; 2080 } 2081 2082 static void 2083 pmc_destroy_owner_descriptor(struct pmc_owner *po) 2084 { 2085 2086 PMCDBG4(OWN,REL,1, "destroy-owner po=%p proc=%p (%d, %s)", 2087 po, po->po_owner, po->po_owner->p_pid, po->po_owner->p_comm); 2088 2089 mtx_destroy(&po->po_mtx); 2090 free(po, M_PMC); 2091 } 2092 2093 /* 2094 * find the descriptor corresponding to process 'p', adding or removing it 2095 * as specified by 'mode'. 2096 */ 2097 2098 static struct pmc_process * 2099 pmc_find_process_descriptor(struct proc *p, uint32_t mode) 2100 { 2101 uint32_t hindex; 2102 struct pmc_process *pp, *ppnew; 2103 struct pmc_processhash *pph; 2104 2105 hindex = PMC_HASH_PTR(p, pmc_processhashmask); 2106 pph = &pmc_processhash[hindex]; 2107 2108 ppnew = NULL; 2109 2110 /* 2111 * Pre-allocate memory in the FIND_ALLOCATE case since we 2112 * cannot call malloc(9) once we hold a spin lock. 2113 */ 2114 if (mode & PMC_FLAG_ALLOCATE) 2115 ppnew = malloc(sizeof(struct pmc_process) + md->pmd_npmc * 2116 sizeof(struct pmc_targetstate), M_PMC, M_WAITOK|M_ZERO); 2117 2118 mtx_lock_spin(&pmc_processhash_mtx); 2119 LIST_FOREACH(pp, pph, pp_next) 2120 if (pp->pp_proc == p) 2121 break; 2122 2123 if ((mode & PMC_FLAG_REMOVE) && pp != NULL) 2124 LIST_REMOVE(pp, pp_next); 2125 2126 if ((mode & PMC_FLAG_ALLOCATE) && pp == NULL && 2127 ppnew != NULL) { 2128 ppnew->pp_proc = p; 2129 LIST_INSERT_HEAD(pph, ppnew, pp_next); 2130 pp = ppnew; 2131 ppnew = NULL; 2132 } 2133 mtx_unlock_spin(&pmc_processhash_mtx); 2134 2135 if (pp != NULL && ppnew != NULL) 2136 free(ppnew, M_PMC); 2137 2138 return pp; 2139 } 2140 2141 /* 2142 * remove a process descriptor from the process hash table. 2143 */ 2144 2145 static void 2146 pmc_remove_process_descriptor(struct pmc_process *pp) 2147 { 2148 KASSERT(pp->pp_refcnt == 0, 2149 ("[pmc,%d] Removing process descriptor %p with count %d", 2150 __LINE__, pp, pp->pp_refcnt)); 2151 2152 mtx_lock_spin(&pmc_processhash_mtx); 2153 LIST_REMOVE(pp, pp_next); 2154 mtx_unlock_spin(&pmc_processhash_mtx); 2155 } 2156 2157 2158 /* 2159 * find an owner descriptor corresponding to proc 'p' 2160 */ 2161 2162 static struct pmc_owner * 2163 pmc_find_owner_descriptor(struct proc *p) 2164 { 2165 uint32_t hindex; 2166 struct pmc_owner *po; 2167 struct pmc_ownerhash *poh; 2168 2169 hindex = PMC_HASH_PTR(p, pmc_ownerhashmask); 2170 poh = &pmc_ownerhash[hindex]; 2171 2172 po = NULL; 2173 LIST_FOREACH(po, poh, po_next) 2174 if (po->po_owner == p) 2175 break; 2176 2177 PMCDBG5(OWN,FND,1, "find-owner proc=%p (%d, %s) hindex=0x%x -> " 2178 "pmc-owner=%p", p, p->p_pid, p->p_comm, hindex, po); 2179 2180 return po; 2181 } 2182 2183 /* 2184 * pmc_allocate_pmc_descriptor 2185 * 2186 * Allocate a pmc descriptor and initialize its 2187 * fields. 2188 */ 2189 2190 static struct pmc * 2191 pmc_allocate_pmc_descriptor(void) 2192 { 2193 struct pmc *pmc; 2194 2195 pmc = malloc(sizeof(struct pmc), M_PMC, M_WAITOK|M_ZERO); 2196 2197 PMCDBG1(PMC,ALL,1, "allocate-pmc -> pmc=%p", pmc); 2198 2199 return pmc; 2200 } 2201 2202 /* 2203 * Destroy a pmc descriptor. 2204 */ 2205 2206 static void 2207 pmc_destroy_pmc_descriptor(struct pmc *pm) 2208 { 2209 2210 KASSERT(pm->pm_state == PMC_STATE_DELETED || 2211 pm->pm_state == PMC_STATE_FREE, 2212 ("[pmc,%d] destroying non-deleted PMC", __LINE__)); 2213 KASSERT(LIST_EMPTY(&pm->pm_targets), 2214 ("[pmc,%d] destroying pmc with targets", __LINE__)); 2215 KASSERT(pm->pm_owner == NULL, 2216 ("[pmc,%d] destroying pmc attached to an owner", __LINE__)); 2217 KASSERT(pm->pm_runcount == 0, 2218 ("[pmc,%d] pmc has non-zero run count %d", __LINE__, 2219 pm->pm_runcount)); 2220 2221 free(pm, M_PMC); 2222 } 2223 2224 static void 2225 pmc_wait_for_pmc_idle(struct pmc *pm) 2226 { 2227 #ifdef HWPMC_DEBUG 2228 volatile int maxloop; 2229 2230 maxloop = 100 * pmc_cpu_max(); 2231 #endif 2232 /* 2233 * Loop (with a forced context switch) till the PMC's runcount 2234 * comes down to zero. 2235 */ 2236 while (atomic_load_acq_32(&pm->pm_runcount) > 0) { 2237 #ifdef HWPMC_DEBUG 2238 maxloop--; 2239 KASSERT(maxloop > 0, 2240 ("[pmc,%d] (ri%d, rc%d) waiting too long for " 2241 "pmc to be free", __LINE__, 2242 PMC_TO_ROWINDEX(pm), pm->pm_runcount)); 2243 #endif 2244 pmc_force_context_switch(); 2245 } 2246 } 2247 2248 /* 2249 * This function does the following things: 2250 * 2251 * - detaches the PMC from hardware 2252 * - unlinks all target threads that were attached to it 2253 * - removes the PMC from its owner's list 2254 * - destroys the PMC private mutex 2255 * 2256 * Once this function completes, the given pmc pointer can be freed by 2257 * calling pmc_destroy_pmc_descriptor(). 2258 */ 2259 2260 static void 2261 pmc_release_pmc_descriptor(struct pmc *pm) 2262 { 2263 enum pmc_mode mode; 2264 struct pmc_hw *phw; 2265 u_int adjri, ri, cpu; 2266 struct pmc_owner *po; 2267 struct pmc_binding pb; 2268 struct pmc_process *pp; 2269 struct pmc_classdep *pcd; 2270 struct pmc_target *ptgt, *tmp; 2271 2272 sx_assert(&pmc_sx, SX_XLOCKED); 2273 2274 KASSERT(pm, ("[pmc,%d] null pmc", __LINE__)); 2275 2276 ri = PMC_TO_ROWINDEX(pm); 2277 pcd = pmc_ri_to_classdep(md, ri, &adjri); 2278 mode = PMC_TO_MODE(pm); 2279 2280 PMCDBG3(PMC,REL,1, "release-pmc pmc=%p ri=%d mode=%d", pm, ri, 2281 mode); 2282 2283 /* 2284 * First, we take the PMC off hardware. 2285 */ 2286 cpu = 0; 2287 if (PMC_IS_SYSTEM_MODE(mode)) { 2288 2289 /* 2290 * A system mode PMC runs on a specific CPU. Switch 2291 * to this CPU and turn hardware off. 2292 */ 2293 pmc_save_cpu_binding(&pb); 2294 2295 cpu = PMC_TO_CPU(pm); 2296 2297 pmc_select_cpu(cpu); 2298 2299 /* switch off non-stalled CPUs */ 2300 CPU_CLR_ATOMIC(cpu, &pm->pm_cpustate); 2301 if (pm->pm_state == PMC_STATE_RUNNING && 2302 !CPU_ISSET(cpu, &pm->pm_stalled)) { 2303 2304 phw = pmc_pcpu[cpu]->pc_hwpmcs[ri]; 2305 2306 KASSERT(phw->phw_pmc == pm, 2307 ("[pmc, %d] pmc ptr ri(%d) hw(%p) pm(%p)", 2308 __LINE__, ri, phw->phw_pmc, pm)); 2309 PMCDBG2(PMC,REL,2, "stopping cpu=%d ri=%d", cpu, ri); 2310 2311 critical_enter(); 2312 pcd->pcd_stop_pmc(cpu, adjri); 2313 critical_exit(); 2314 } 2315 2316 PMCDBG2(PMC,REL,2, "decfg cpu=%d ri=%d", cpu, ri); 2317 2318 critical_enter(); 2319 pcd->pcd_config_pmc(cpu, adjri, NULL); 2320 critical_exit(); 2321 2322 /* adjust the global and process count of SS mode PMCs */ 2323 if (mode == PMC_MODE_SS && pm->pm_state == PMC_STATE_RUNNING) { 2324 po = pm->pm_owner; 2325 po->po_sscount--; 2326 if (po->po_sscount == 0) { 2327 atomic_subtract_rel_int(&pmc_ss_count, 1); 2328 LIST_REMOVE(po, po_ssnext); 2329 } 2330 } 2331 2332 pm->pm_state = PMC_STATE_DELETED; 2333 2334 pmc_restore_cpu_binding(&pb); 2335 2336 /* 2337 * We could have references to this PMC structure in 2338 * the per-cpu sample queues. Wait for the queue to 2339 * drain. 2340 */ 2341 pmc_wait_for_pmc_idle(pm); 2342 2343 } else if (PMC_IS_VIRTUAL_MODE(mode)) { 2344 2345 /* 2346 * A virtual PMC could be running on multiple CPUs at 2347 * a given instant. 2348 * 2349 * By marking its state as DELETED, we ensure that 2350 * this PMC is never further scheduled on hardware. 2351 * 2352 * Then we wait till all CPUs are done with this PMC. 2353 */ 2354 pm->pm_state = PMC_STATE_DELETED; 2355 2356 2357 /* Wait for the PMCs runcount to come to zero. */ 2358 pmc_wait_for_pmc_idle(pm); 2359 2360 /* 2361 * At this point the PMC is off all CPUs and cannot be 2362 * freshly scheduled onto a CPU. It is now safe to 2363 * unlink all targets from this PMC. If a 2364 * process-record's refcount falls to zero, we remove 2365 * it from the hash table. The module-wide SX lock 2366 * protects us from races. 2367 */ 2368 LIST_FOREACH_SAFE(ptgt, &pm->pm_targets, pt_next, tmp) { 2369 pp = ptgt->pt_process; 2370 pmc_unlink_target_process(pm, pp); /* frees 'ptgt' */ 2371 2372 PMCDBG1(PMC,REL,3, "pp->refcnt=%d", pp->pp_refcnt); 2373 2374 /* 2375 * If the target process record shows that no 2376 * PMCs are attached to it, reclaim its space. 2377 */ 2378 2379 if (pp->pp_refcnt == 0) { 2380 pmc_remove_process_descriptor(pp); 2381 free(pp, M_PMC); 2382 } 2383 } 2384 2385 cpu = curthread->td_oncpu; /* setup cpu for pmd_release() */ 2386 2387 } 2388 2389 /* 2390 * Release any MD resources 2391 */ 2392 (void) pcd->pcd_release_pmc(cpu, adjri, pm); 2393 2394 /* 2395 * Update row disposition 2396 */ 2397 2398 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) 2399 PMC_UNMARK_ROW_STANDALONE(ri); 2400 else 2401 PMC_UNMARK_ROW_THREAD(ri); 2402 2403 /* unlink from the owner's list */ 2404 if (pm->pm_owner) { 2405 LIST_REMOVE(pm, pm_next); 2406 pm->pm_owner = NULL; 2407 } 2408 } 2409 2410 /* 2411 * Register an owner and a pmc. 2412 */ 2413 2414 static int 2415 pmc_register_owner(struct proc *p, struct pmc *pmc) 2416 { 2417 struct pmc_owner *po; 2418 2419 sx_assert(&pmc_sx, SX_XLOCKED); 2420 2421 if ((po = pmc_find_owner_descriptor(p)) == NULL) 2422 if ((po = pmc_allocate_owner_descriptor(p)) == NULL) 2423 return ENOMEM; 2424 2425 KASSERT(pmc->pm_owner == NULL, 2426 ("[pmc,%d] attempting to own an initialized PMC", __LINE__)); 2427 pmc->pm_owner = po; 2428 2429 LIST_INSERT_HEAD(&po->po_pmcs, pmc, pm_next); 2430 2431 PROC_LOCK(p); 2432 p->p_flag |= P_HWPMC; 2433 PROC_UNLOCK(p); 2434 2435 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 2436 pmclog_process_pmcallocate(pmc); 2437 2438 PMCDBG2(PMC,REG,1, "register-owner pmc-owner=%p pmc=%p", 2439 po, pmc); 2440 2441 return 0; 2442 } 2443 2444 /* 2445 * Return the current row disposition: 2446 * == 0 => FREE 2447 * > 0 => PROCESS MODE 2448 * < 0 => SYSTEM MODE 2449 */ 2450 2451 int 2452 pmc_getrowdisp(int ri) 2453 { 2454 return pmc_pmcdisp[ri]; 2455 } 2456 2457 /* 2458 * Check if a PMC at row index 'ri' can be allocated to the current 2459 * process. 2460 * 2461 * Allocation can fail if: 2462 * - the current process is already being profiled by a PMC at index 'ri', 2463 * attached to it via OP_PMCATTACH. 2464 * - the current process has already allocated a PMC at index 'ri' 2465 * via OP_ALLOCATE. 2466 */ 2467 2468 static int 2469 pmc_can_allocate_rowindex(struct proc *p, unsigned int ri, int cpu) 2470 { 2471 enum pmc_mode mode; 2472 struct pmc *pm; 2473 struct pmc_owner *po; 2474 struct pmc_process *pp; 2475 2476 PMCDBG5(PMC,ALR,1, "can-allocate-rowindex proc=%p (%d, %s) ri=%d " 2477 "cpu=%d", p, p->p_pid, p->p_comm, ri, cpu); 2478 2479 /* 2480 * We shouldn't have already allocated a process-mode PMC at 2481 * row index 'ri'. 2482 * 2483 * We shouldn't have allocated a system-wide PMC on the same 2484 * CPU and same RI. 2485 */ 2486 if ((po = pmc_find_owner_descriptor(p)) != NULL) 2487 LIST_FOREACH(pm, &po->po_pmcs, pm_next) { 2488 if (PMC_TO_ROWINDEX(pm) == ri) { 2489 mode = PMC_TO_MODE(pm); 2490 if (PMC_IS_VIRTUAL_MODE(mode)) 2491 return EEXIST; 2492 if (PMC_IS_SYSTEM_MODE(mode) && 2493 (int) PMC_TO_CPU(pm) == cpu) 2494 return EEXIST; 2495 } 2496 } 2497 2498 /* 2499 * We also shouldn't be the target of any PMC at this index 2500 * since otherwise a PMC_ATTACH to ourselves will fail. 2501 */ 2502 if ((pp = pmc_find_process_descriptor(p, 0)) != NULL) 2503 if (pp->pp_pmcs[ri].pp_pmc) 2504 return EEXIST; 2505 2506 PMCDBG4(PMC,ALR,2, "can-allocate-rowindex proc=%p (%d, %s) ri=%d ok", 2507 p, p->p_pid, p->p_comm, ri); 2508 2509 return 0; 2510 } 2511 2512 /* 2513 * Check if a given PMC at row index 'ri' can be currently used in 2514 * mode 'mode'. 2515 */ 2516 2517 static int 2518 pmc_can_allocate_row(int ri, enum pmc_mode mode) 2519 { 2520 enum pmc_disp disp; 2521 2522 sx_assert(&pmc_sx, SX_XLOCKED); 2523 2524 PMCDBG2(PMC,ALR,1, "can-allocate-row ri=%d mode=%d", ri, mode); 2525 2526 if (PMC_IS_SYSTEM_MODE(mode)) 2527 disp = PMC_DISP_STANDALONE; 2528 else 2529 disp = PMC_DISP_THREAD; 2530 2531 /* 2532 * check disposition for PMC row 'ri': 2533 * 2534 * Expected disposition Row-disposition Result 2535 * 2536 * STANDALONE STANDALONE or FREE proceed 2537 * STANDALONE THREAD fail 2538 * THREAD THREAD or FREE proceed 2539 * THREAD STANDALONE fail 2540 */ 2541 2542 if (!PMC_ROW_DISP_IS_FREE(ri) && 2543 !(disp == PMC_DISP_THREAD && PMC_ROW_DISP_IS_THREAD(ri)) && 2544 !(disp == PMC_DISP_STANDALONE && PMC_ROW_DISP_IS_STANDALONE(ri))) 2545 return EBUSY; 2546 2547 /* 2548 * All OK 2549 */ 2550 2551 PMCDBG2(PMC,ALR,2, "can-allocate-row ri=%d mode=%d ok", ri, mode); 2552 2553 return 0; 2554 2555 } 2556 2557 /* 2558 * Find a PMC descriptor with user handle 'pmcid' for thread 'td'. 2559 */ 2560 2561 static struct pmc * 2562 pmc_find_pmc_descriptor_in_process(struct pmc_owner *po, pmc_id_t pmcid) 2563 { 2564 struct pmc *pm; 2565 2566 KASSERT(PMC_ID_TO_ROWINDEX(pmcid) < md->pmd_npmc, 2567 ("[pmc,%d] Illegal pmc index %d (max %d)", __LINE__, 2568 PMC_ID_TO_ROWINDEX(pmcid), md->pmd_npmc)); 2569 2570 LIST_FOREACH(pm, &po->po_pmcs, pm_next) 2571 if (pm->pm_id == pmcid) 2572 return pm; 2573 2574 return NULL; 2575 } 2576 2577 static int 2578 pmc_find_pmc(pmc_id_t pmcid, struct pmc **pmc) 2579 { 2580 2581 struct pmc *pm, *opm; 2582 struct pmc_owner *po; 2583 struct pmc_process *pp; 2584 2585 KASSERT(PMC_ID_TO_ROWINDEX(pmcid) < md->pmd_npmc, 2586 ("[pmc,%d] Illegal pmc index %d (max %d)", __LINE__, 2587 PMC_ID_TO_ROWINDEX(pmcid), md->pmd_npmc)); 2588 PMCDBG1(PMC,FND,1, "find-pmc id=%d", pmcid); 2589 2590 if ((po = pmc_find_owner_descriptor(curthread->td_proc)) == NULL) { 2591 /* 2592 * In case of PMC_F_DESCENDANTS child processes we will not find 2593 * the current process in the owners hash list. Find the owner 2594 * process first and from there lookup the po. 2595 */ 2596 if ((pp = pmc_find_process_descriptor(curthread->td_proc, 2597 PMC_FLAG_NONE)) == NULL) { 2598 return ESRCH; 2599 } else { 2600 opm = pp->pp_pmcs[PMC_ID_TO_ROWINDEX(pmcid)].pp_pmc; 2601 if (opm == NULL) 2602 return ESRCH; 2603 if ((opm->pm_flags & (PMC_F_ATTACHED_TO_OWNER| 2604 PMC_F_DESCENDANTS)) != (PMC_F_ATTACHED_TO_OWNER| 2605 PMC_F_DESCENDANTS)) 2606 return ESRCH; 2607 po = opm->pm_owner; 2608 } 2609 } 2610 2611 if ((pm = pmc_find_pmc_descriptor_in_process(po, pmcid)) == NULL) 2612 return EINVAL; 2613 2614 PMCDBG2(PMC,FND,2, "find-pmc id=%d -> pmc=%p", pmcid, pm); 2615 2616 *pmc = pm; 2617 return 0; 2618 } 2619 2620 /* 2621 * Start a PMC. 2622 */ 2623 2624 static int 2625 pmc_start(struct pmc *pm) 2626 { 2627 enum pmc_mode mode; 2628 struct pmc_owner *po; 2629 struct pmc_binding pb; 2630 struct pmc_classdep *pcd; 2631 int adjri, error, cpu, ri; 2632 2633 KASSERT(pm != NULL, 2634 ("[pmc,%d] null pm", __LINE__)); 2635 2636 mode = PMC_TO_MODE(pm); 2637 ri = PMC_TO_ROWINDEX(pm); 2638 pcd = pmc_ri_to_classdep(md, ri, &adjri); 2639 2640 error = 0; 2641 2642 PMCDBG3(PMC,OPS,1, "start pmc=%p mode=%d ri=%d", pm, mode, ri); 2643 2644 po = pm->pm_owner; 2645 2646 /* 2647 * Disallow PMCSTART if a logfile is required but has not been 2648 * configured yet. 2649 */ 2650 if ((pm->pm_flags & PMC_F_NEEDS_LOGFILE) && 2651 (po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) 2652 return (EDOOFUS); /* programming error */ 2653 2654 /* 2655 * If this is a sampling mode PMC, log mapping information for 2656 * the kernel modules that are currently loaded. 2657 */ 2658 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 2659 pmc_log_kernel_mappings(pm); 2660 2661 if (PMC_IS_VIRTUAL_MODE(mode)) { 2662 2663 /* 2664 * If a PMCATTACH has never been done on this PMC, 2665 * attach it to its owner process. 2666 */ 2667 2668 if (LIST_EMPTY(&pm->pm_targets)) 2669 error = (pm->pm_flags & PMC_F_ATTACH_DONE) ? ESRCH : 2670 pmc_attach_process(po->po_owner, pm); 2671 2672 /* 2673 * If the PMC is attached to its owner, then force a context 2674 * switch to ensure that the MD state gets set correctly. 2675 */ 2676 2677 if (error == 0) { 2678 pm->pm_state = PMC_STATE_RUNNING; 2679 if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) 2680 pmc_force_context_switch(); 2681 } 2682 2683 return (error); 2684 } 2685 2686 2687 /* 2688 * A system-wide PMC. 2689 * 2690 * Add the owner to the global list if this is a system-wide 2691 * sampling PMC. 2692 */ 2693 2694 if (mode == PMC_MODE_SS) { 2695 if (po->po_sscount == 0) { 2696 LIST_INSERT_HEAD(&pmc_ss_owners, po, po_ssnext); 2697 atomic_add_rel_int(&pmc_ss_count, 1); 2698 PMCDBG1(PMC,OPS,1, "po=%p in global list", po); 2699 } 2700 po->po_sscount++; 2701 2702 /* 2703 * Log mapping information for all existing processes in the 2704 * system. Subsequent mappings are logged as they happen; 2705 * see pmc_process_mmap(). 2706 */ 2707 if (po->po_logprocmaps == 0) { 2708 pmc_log_all_process_mappings(po); 2709 po->po_logprocmaps = 1; 2710 } 2711 } 2712 2713 /* 2714 * Move to the CPU associated with this 2715 * PMC, and start the hardware. 2716 */ 2717 2718 pmc_save_cpu_binding(&pb); 2719 2720 cpu = PMC_TO_CPU(pm); 2721 2722 if (!pmc_cpu_is_active(cpu)) 2723 return (ENXIO); 2724 2725 pmc_select_cpu(cpu); 2726 2727 /* 2728 * global PMCs are configured at allocation time 2729 * so write out the initial value and start the PMC. 2730 */ 2731 2732 pm->pm_state = PMC_STATE_RUNNING; 2733 2734 critical_enter(); 2735 if ((error = pcd->pcd_write_pmc(cpu, adjri, 2736 PMC_IS_SAMPLING_MODE(mode) ? 2737 pm->pm_sc.pm_reloadcount : 2738 pm->pm_sc.pm_initial)) == 0) { 2739 /* If a sampling mode PMC, reset stalled state. */ 2740 if (PMC_IS_SAMPLING_MODE(mode)) 2741 CPU_CLR_ATOMIC(cpu, &pm->pm_stalled); 2742 2743 /* Indicate that we desire this to run. Start it. */ 2744 CPU_SET_ATOMIC(cpu, &pm->pm_cpustate); 2745 error = pcd->pcd_start_pmc(cpu, adjri); 2746 } 2747 critical_exit(); 2748 2749 pmc_restore_cpu_binding(&pb); 2750 2751 return (error); 2752 } 2753 2754 /* 2755 * Stop a PMC. 2756 */ 2757 2758 static int 2759 pmc_stop(struct pmc *pm) 2760 { 2761 struct pmc_owner *po; 2762 struct pmc_binding pb; 2763 struct pmc_classdep *pcd; 2764 int adjri, cpu, error, ri; 2765 2766 KASSERT(pm != NULL, ("[pmc,%d] null pmc", __LINE__)); 2767 2768 PMCDBG3(PMC,OPS,1, "stop pmc=%p mode=%d ri=%d", pm, 2769 PMC_TO_MODE(pm), PMC_TO_ROWINDEX(pm)); 2770 2771 pm->pm_state = PMC_STATE_STOPPED; 2772 2773 /* 2774 * If the PMC is a virtual mode one, changing the state to 2775 * non-RUNNING is enough to ensure that the PMC never gets 2776 * scheduled. 2777 * 2778 * If this PMC is current running on a CPU, then it will 2779 * handled correctly at the time its target process is context 2780 * switched out. 2781 */ 2782 2783 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) 2784 return 0; 2785 2786 /* 2787 * A system-mode PMC. Move to the CPU associated with 2788 * this PMC, and stop the hardware. We update the 2789 * 'initial count' so that a subsequent PMCSTART will 2790 * resume counting from the current hardware count. 2791 */ 2792 2793 pmc_save_cpu_binding(&pb); 2794 2795 cpu = PMC_TO_CPU(pm); 2796 2797 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 2798 ("[pmc,%d] illegal cpu=%d", __LINE__, cpu)); 2799 2800 if (!pmc_cpu_is_active(cpu)) 2801 return ENXIO; 2802 2803 pmc_select_cpu(cpu); 2804 2805 ri = PMC_TO_ROWINDEX(pm); 2806 pcd = pmc_ri_to_classdep(md, ri, &adjri); 2807 2808 CPU_CLR_ATOMIC(cpu, &pm->pm_cpustate); 2809 critical_enter(); 2810 if ((error = pcd->pcd_stop_pmc(cpu, adjri)) == 0) 2811 error = pcd->pcd_read_pmc(cpu, adjri, &pm->pm_sc.pm_initial); 2812 critical_exit(); 2813 2814 pmc_restore_cpu_binding(&pb); 2815 2816 po = pm->pm_owner; 2817 2818 /* remove this owner from the global list of SS PMC owners */ 2819 if (PMC_TO_MODE(pm) == PMC_MODE_SS) { 2820 po->po_sscount--; 2821 if (po->po_sscount == 0) { 2822 atomic_subtract_rel_int(&pmc_ss_count, 1); 2823 LIST_REMOVE(po, po_ssnext); 2824 PMCDBG1(PMC,OPS,2,"po=%p removed from global list", po); 2825 } 2826 } 2827 2828 return (error); 2829 } 2830 2831 2832 #ifdef HWPMC_DEBUG 2833 static const char *pmc_op_to_name[] = { 2834 #undef __PMC_OP 2835 #define __PMC_OP(N, D) #N , 2836 __PMC_OPS() 2837 NULL 2838 }; 2839 #endif 2840 2841 /* 2842 * The syscall interface 2843 */ 2844 2845 #define PMC_GET_SX_XLOCK(...) do { \ 2846 sx_xlock(&pmc_sx); \ 2847 if (pmc_hook == NULL) { \ 2848 sx_xunlock(&pmc_sx); \ 2849 return __VA_ARGS__; \ 2850 } \ 2851 } while (0) 2852 2853 #define PMC_DOWNGRADE_SX() do { \ 2854 sx_downgrade(&pmc_sx); \ 2855 is_sx_downgraded = 1; \ 2856 } while (0) 2857 2858 static int 2859 pmc_syscall_handler(struct thread *td, void *syscall_args) 2860 { 2861 int error, is_sx_downgraded, is_sx_locked, op; 2862 struct pmc_syscall_args *c; 2863 void *arg; 2864 2865 PMC_GET_SX_XLOCK(ENOSYS); 2866 2867 DROP_GIANT(); 2868 2869 is_sx_downgraded = 0; 2870 is_sx_locked = 1; 2871 2872 c = (struct pmc_syscall_args *) syscall_args; 2873 2874 op = c->pmop_code; 2875 arg = c->pmop_data; 2876 2877 PMCDBG3(MOD,PMS,1, "syscall op=%d \"%s\" arg=%p", op, 2878 pmc_op_to_name[op], arg); 2879 2880 error = 0; 2881 atomic_add_int(&pmc_stats.pm_syscalls, 1); 2882 2883 switch(op) 2884 { 2885 2886 2887 /* 2888 * Configure a log file. 2889 * 2890 * XXX This OP will be reworked. 2891 */ 2892 2893 case PMC_OP_CONFIGURELOG: 2894 { 2895 struct proc *p; 2896 struct pmc *pm; 2897 struct pmc_owner *po; 2898 struct pmc_op_configurelog cl; 2899 2900 sx_assert(&pmc_sx, SX_XLOCKED); 2901 2902 if ((error = copyin(arg, &cl, sizeof(cl))) != 0) 2903 break; 2904 2905 /* mark this process as owning a log file */ 2906 p = td->td_proc; 2907 if ((po = pmc_find_owner_descriptor(p)) == NULL) 2908 if ((po = pmc_allocate_owner_descriptor(p)) == NULL) { 2909 error = ENOMEM; 2910 break; 2911 } 2912 2913 /* 2914 * If a valid fd was passed in, try to configure that, 2915 * otherwise if 'fd' was less than zero and there was 2916 * a log file configured, flush its buffers and 2917 * de-configure it. 2918 */ 2919 if (cl.pm_logfd >= 0) { 2920 sx_xunlock(&pmc_sx); 2921 is_sx_locked = 0; 2922 error = pmclog_configure_log(md, po, cl.pm_logfd); 2923 } else if (po->po_flags & PMC_PO_OWNS_LOGFILE) { 2924 pmclog_process_closelog(po); 2925 error = pmclog_close(po); 2926 if (error == 0) { 2927 LIST_FOREACH(pm, &po->po_pmcs, pm_next) 2928 if (pm->pm_flags & PMC_F_NEEDS_LOGFILE && 2929 pm->pm_state == PMC_STATE_RUNNING) 2930 pmc_stop(pm); 2931 error = pmclog_deconfigure_log(po); 2932 } 2933 } else 2934 error = EINVAL; 2935 2936 if (error) 2937 break; 2938 } 2939 break; 2940 2941 /* 2942 * Flush a log file. 2943 */ 2944 2945 case PMC_OP_FLUSHLOG: 2946 { 2947 struct pmc_owner *po; 2948 2949 sx_assert(&pmc_sx, SX_XLOCKED); 2950 2951 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 2952 error = EINVAL; 2953 break; 2954 } 2955 2956 error = pmclog_flush(po); 2957 } 2958 break; 2959 2960 /* 2961 * Close a log file. 2962 */ 2963 2964 case PMC_OP_CLOSELOG: 2965 { 2966 struct pmc_owner *po; 2967 2968 sx_assert(&pmc_sx, SX_XLOCKED); 2969 2970 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 2971 error = EINVAL; 2972 break; 2973 } 2974 2975 error = pmclog_close(po); 2976 } 2977 break; 2978 2979 /* 2980 * Retrieve hardware configuration. 2981 */ 2982 2983 case PMC_OP_GETCPUINFO: /* CPU information */ 2984 { 2985 struct pmc_op_getcpuinfo gci; 2986 struct pmc_classinfo *pci; 2987 struct pmc_classdep *pcd; 2988 int cl; 2989 2990 gci.pm_cputype = md->pmd_cputype; 2991 gci.pm_ncpu = pmc_cpu_max(); 2992 gci.pm_npmc = md->pmd_npmc; 2993 gci.pm_nclass = md->pmd_nclass; 2994 pci = gci.pm_classes; 2995 pcd = md->pmd_classdep; 2996 for (cl = 0; cl < md->pmd_nclass; cl++, pci++, pcd++) { 2997 pci->pm_caps = pcd->pcd_caps; 2998 pci->pm_class = pcd->pcd_class; 2999 pci->pm_width = pcd->pcd_width; 3000 pci->pm_num = pcd->pcd_num; 3001 } 3002 error = copyout(&gci, arg, sizeof(gci)); 3003 } 3004 break; 3005 3006 /* 3007 * Retrieve soft events list. 3008 */ 3009 case PMC_OP_GETDYNEVENTINFO: 3010 { 3011 enum pmc_class cl; 3012 enum pmc_event ev; 3013 struct pmc_op_getdyneventinfo *gei; 3014 struct pmc_dyn_event_descr dev; 3015 struct pmc_soft *ps; 3016 uint32_t nevent; 3017 3018 sx_assert(&pmc_sx, SX_LOCKED); 3019 3020 gei = (struct pmc_op_getdyneventinfo *) arg; 3021 3022 if ((error = copyin(&gei->pm_class, &cl, sizeof(cl))) != 0) 3023 break; 3024 3025 /* Only SOFT class is dynamic. */ 3026 if (cl != PMC_CLASS_SOFT) { 3027 error = EINVAL; 3028 break; 3029 } 3030 3031 nevent = 0; 3032 for (ev = PMC_EV_SOFT_FIRST; (int)ev <= PMC_EV_SOFT_LAST; ev++) { 3033 ps = pmc_soft_ev_acquire(ev); 3034 if (ps == NULL) 3035 continue; 3036 bcopy(&ps->ps_ev, &dev, sizeof(dev)); 3037 pmc_soft_ev_release(ps); 3038 3039 error = copyout(&dev, 3040 &gei->pm_events[nevent], 3041 sizeof(struct pmc_dyn_event_descr)); 3042 if (error != 0) 3043 break; 3044 nevent++; 3045 } 3046 if (error != 0) 3047 break; 3048 3049 error = copyout(&nevent, &gei->pm_nevent, 3050 sizeof(nevent)); 3051 } 3052 break; 3053 3054 /* 3055 * Get module statistics 3056 */ 3057 3058 case PMC_OP_GETDRIVERSTATS: 3059 { 3060 struct pmc_op_getdriverstats gms; 3061 3062 bcopy(&pmc_stats, &gms, sizeof(gms)); 3063 error = copyout(&gms, arg, sizeof(gms)); 3064 } 3065 break; 3066 3067 3068 /* 3069 * Retrieve module version number 3070 */ 3071 3072 case PMC_OP_GETMODULEVERSION: 3073 { 3074 uint32_t cv, modv; 3075 3076 /* retrieve the client's idea of the ABI version */ 3077 if ((error = copyin(arg, &cv, sizeof(uint32_t))) != 0) 3078 break; 3079 /* don't service clients newer than our driver */ 3080 modv = PMC_VERSION; 3081 if ((cv & 0xFFFF0000) > (modv & 0xFFFF0000)) { 3082 error = EPROGMISMATCH; 3083 break; 3084 } 3085 error = copyout(&modv, arg, sizeof(int)); 3086 } 3087 break; 3088 3089 3090 /* 3091 * Retrieve the state of all the PMCs on a given 3092 * CPU. 3093 */ 3094 3095 case PMC_OP_GETPMCINFO: 3096 { 3097 int ari; 3098 struct pmc *pm; 3099 size_t pmcinfo_size; 3100 uint32_t cpu, n, npmc; 3101 struct pmc_owner *po; 3102 struct pmc_binding pb; 3103 struct pmc_classdep *pcd; 3104 struct pmc_info *p, *pmcinfo; 3105 struct pmc_op_getpmcinfo *gpi; 3106 3107 PMC_DOWNGRADE_SX(); 3108 3109 gpi = (struct pmc_op_getpmcinfo *) arg; 3110 3111 if ((error = copyin(&gpi->pm_cpu, &cpu, sizeof(cpu))) != 0) 3112 break; 3113 3114 if (cpu >= pmc_cpu_max()) { 3115 error = EINVAL; 3116 break; 3117 } 3118 3119 if (!pmc_cpu_is_active(cpu)) { 3120 error = ENXIO; 3121 break; 3122 } 3123 3124 /* switch to CPU 'cpu' */ 3125 pmc_save_cpu_binding(&pb); 3126 pmc_select_cpu(cpu); 3127 3128 npmc = md->pmd_npmc; 3129 3130 pmcinfo_size = npmc * sizeof(struct pmc_info); 3131 pmcinfo = malloc(pmcinfo_size, M_PMC, M_WAITOK); 3132 3133 p = pmcinfo; 3134 3135 for (n = 0; n < md->pmd_npmc; n++, p++) { 3136 3137 pcd = pmc_ri_to_classdep(md, n, &ari); 3138 3139 KASSERT(pcd != NULL, 3140 ("[pmc,%d] null pcd ri=%d", __LINE__, n)); 3141 3142 if ((error = pcd->pcd_describe(cpu, ari, p, &pm)) != 0) 3143 break; 3144 3145 if (PMC_ROW_DISP_IS_STANDALONE(n)) 3146 p->pm_rowdisp = PMC_DISP_STANDALONE; 3147 else if (PMC_ROW_DISP_IS_THREAD(n)) 3148 p->pm_rowdisp = PMC_DISP_THREAD; 3149 else 3150 p->pm_rowdisp = PMC_DISP_FREE; 3151 3152 p->pm_ownerpid = -1; 3153 3154 if (pm == NULL) /* no PMC associated */ 3155 continue; 3156 3157 po = pm->pm_owner; 3158 3159 KASSERT(po->po_owner != NULL, 3160 ("[pmc,%d] pmc_owner had a null proc pointer", 3161 __LINE__)); 3162 3163 p->pm_ownerpid = po->po_owner->p_pid; 3164 p->pm_mode = PMC_TO_MODE(pm); 3165 p->pm_event = pm->pm_event; 3166 p->pm_flags = pm->pm_flags; 3167 3168 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 3169 p->pm_reloadcount = 3170 pm->pm_sc.pm_reloadcount; 3171 } 3172 3173 pmc_restore_cpu_binding(&pb); 3174 3175 /* now copy out the PMC info collected */ 3176 if (error == 0) 3177 error = copyout(pmcinfo, &gpi->pm_pmcs, pmcinfo_size); 3178 3179 free(pmcinfo, M_PMC); 3180 } 3181 break; 3182 3183 3184 /* 3185 * Set the administrative state of a PMC. I.e. whether 3186 * the PMC is to be used or not. 3187 */ 3188 3189 case PMC_OP_PMCADMIN: 3190 { 3191 int cpu, ri; 3192 enum pmc_state request; 3193 struct pmc_cpu *pc; 3194 struct pmc_hw *phw; 3195 struct pmc_op_pmcadmin pma; 3196 struct pmc_binding pb; 3197 3198 sx_assert(&pmc_sx, SX_XLOCKED); 3199 3200 KASSERT(td == curthread, 3201 ("[pmc,%d] td != curthread", __LINE__)); 3202 3203 error = priv_check(td, PRIV_PMC_MANAGE); 3204 if (error) 3205 break; 3206 3207 if ((error = copyin(arg, &pma, sizeof(pma))) != 0) 3208 break; 3209 3210 cpu = pma.pm_cpu; 3211 3212 if (cpu < 0 || cpu >= (int) pmc_cpu_max()) { 3213 error = EINVAL; 3214 break; 3215 } 3216 3217 if (!pmc_cpu_is_active(cpu)) { 3218 error = ENXIO; 3219 break; 3220 } 3221 3222 request = pma.pm_state; 3223 3224 if (request != PMC_STATE_DISABLED && 3225 request != PMC_STATE_FREE) { 3226 error = EINVAL; 3227 break; 3228 } 3229 3230 ri = pma.pm_pmc; /* pmc id == row index */ 3231 if (ri < 0 || ri >= (int) md->pmd_npmc) { 3232 error = EINVAL; 3233 break; 3234 } 3235 3236 /* 3237 * We can't disable a PMC with a row-index allocated 3238 * for process virtual PMCs. 3239 */ 3240 3241 if (PMC_ROW_DISP_IS_THREAD(ri) && 3242 request == PMC_STATE_DISABLED) { 3243 error = EBUSY; 3244 break; 3245 } 3246 3247 /* 3248 * otherwise, this PMC on this CPU is either free or 3249 * in system-wide mode. 3250 */ 3251 3252 pmc_save_cpu_binding(&pb); 3253 pmc_select_cpu(cpu); 3254 3255 pc = pmc_pcpu[cpu]; 3256 phw = pc->pc_hwpmcs[ri]; 3257 3258 /* 3259 * XXX do we need some kind of 'forced' disable? 3260 */ 3261 3262 if (phw->phw_pmc == NULL) { 3263 if (request == PMC_STATE_DISABLED && 3264 (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED)) { 3265 phw->phw_state &= ~PMC_PHW_FLAG_IS_ENABLED; 3266 PMC_MARK_ROW_STANDALONE(ri); 3267 } else if (request == PMC_STATE_FREE && 3268 (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0) { 3269 phw->phw_state |= PMC_PHW_FLAG_IS_ENABLED; 3270 PMC_UNMARK_ROW_STANDALONE(ri); 3271 } 3272 /* other cases are a no-op */ 3273 } else 3274 error = EBUSY; 3275 3276 pmc_restore_cpu_binding(&pb); 3277 } 3278 break; 3279 3280 3281 /* 3282 * Allocate a PMC. 3283 */ 3284 3285 case PMC_OP_PMCALLOCATE: 3286 { 3287 int adjri, n; 3288 u_int cpu; 3289 uint32_t caps; 3290 struct pmc *pmc; 3291 enum pmc_mode mode; 3292 struct pmc_hw *phw; 3293 struct pmc_binding pb; 3294 struct pmc_classdep *pcd; 3295 struct pmc_op_pmcallocate pa; 3296 3297 if ((error = copyin(arg, &pa, sizeof(pa))) != 0) 3298 break; 3299 3300 caps = pa.pm_caps; 3301 mode = pa.pm_mode; 3302 cpu = pa.pm_cpu; 3303 3304 if ((mode != PMC_MODE_SS && mode != PMC_MODE_SC && 3305 mode != PMC_MODE_TS && mode != PMC_MODE_TC) || 3306 (cpu != (u_int) PMC_CPU_ANY && cpu >= pmc_cpu_max())) { 3307 error = EINVAL; 3308 break; 3309 } 3310 3311 /* 3312 * Virtual PMCs should only ask for a default CPU. 3313 * System mode PMCs need to specify a non-default CPU. 3314 */ 3315 3316 if ((PMC_IS_VIRTUAL_MODE(mode) && cpu != (u_int) PMC_CPU_ANY) || 3317 (PMC_IS_SYSTEM_MODE(mode) && cpu == (u_int) PMC_CPU_ANY)) { 3318 error = EINVAL; 3319 break; 3320 } 3321 3322 /* 3323 * Check that an inactive CPU is not being asked for. 3324 */ 3325 3326 if (PMC_IS_SYSTEM_MODE(mode) && !pmc_cpu_is_active(cpu)) { 3327 error = ENXIO; 3328 break; 3329 } 3330 3331 /* 3332 * Refuse an allocation for a system-wide PMC if this 3333 * process has been jailed, or if this process lacks 3334 * super-user credentials and the sysctl tunable 3335 * 'security.bsd.unprivileged_syspmcs' is zero. 3336 */ 3337 3338 if (PMC_IS_SYSTEM_MODE(mode)) { 3339 if (jailed(curthread->td_ucred)) { 3340 error = EPERM; 3341 break; 3342 } 3343 if (!pmc_unprivileged_syspmcs) { 3344 error = priv_check(curthread, 3345 PRIV_PMC_SYSTEM); 3346 if (error) 3347 break; 3348 } 3349 } 3350 3351 /* 3352 * Look for valid values for 'pm_flags' 3353 */ 3354 3355 if ((pa.pm_flags & ~(PMC_F_DESCENDANTS | PMC_F_LOG_PROCCSW | 3356 PMC_F_LOG_PROCEXIT | PMC_F_CALLCHAIN)) != 0) { 3357 error = EINVAL; 3358 break; 3359 } 3360 3361 /* process logging options are not allowed for system PMCs */ 3362 if (PMC_IS_SYSTEM_MODE(mode) && (pa.pm_flags & 3363 (PMC_F_LOG_PROCCSW | PMC_F_LOG_PROCEXIT))) { 3364 error = EINVAL; 3365 break; 3366 } 3367 3368 /* 3369 * All sampling mode PMCs need to be able to interrupt the 3370 * CPU. 3371 */ 3372 if (PMC_IS_SAMPLING_MODE(mode)) 3373 caps |= PMC_CAP_INTERRUPT; 3374 3375 /* A valid class specifier should have been passed in. */ 3376 for (n = 0; n < md->pmd_nclass; n++) 3377 if (md->pmd_classdep[n].pcd_class == pa.pm_class) 3378 break; 3379 if (n == md->pmd_nclass) { 3380 error = EINVAL; 3381 break; 3382 } 3383 3384 /* The requested PMC capabilities should be feasible. */ 3385 if ((md->pmd_classdep[n].pcd_caps & caps) != caps) { 3386 error = EOPNOTSUPP; 3387 break; 3388 } 3389 3390 PMCDBG4(PMC,ALL,2, "event=%d caps=0x%x mode=%d cpu=%d", 3391 pa.pm_ev, caps, mode, cpu); 3392 3393 pmc = pmc_allocate_pmc_descriptor(); 3394 pmc->pm_id = PMC_ID_MAKE_ID(cpu,pa.pm_mode,pa.pm_class, 3395 PMC_ID_INVALID); 3396 pmc->pm_event = pa.pm_ev; 3397 pmc->pm_state = PMC_STATE_FREE; 3398 pmc->pm_caps = caps; 3399 pmc->pm_flags = pa.pm_flags; 3400 3401 /* switch thread to CPU 'cpu' */ 3402 pmc_save_cpu_binding(&pb); 3403 3404 #define PMC_IS_SHAREABLE_PMC(cpu, n) \ 3405 (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_state & \ 3406 PMC_PHW_FLAG_IS_SHAREABLE) 3407 #define PMC_IS_UNALLOCATED(cpu, n) \ 3408 (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_pmc == NULL) 3409 3410 if (PMC_IS_SYSTEM_MODE(mode)) { 3411 pmc_select_cpu(cpu); 3412 for (n = 0; n < (int) md->pmd_npmc; n++) { 3413 pcd = pmc_ri_to_classdep(md, n, &adjri); 3414 if (pmc_can_allocate_row(n, mode) == 0 && 3415 pmc_can_allocate_rowindex( 3416 curthread->td_proc, n, cpu) == 0 && 3417 (PMC_IS_UNALLOCATED(cpu, n) || 3418 PMC_IS_SHAREABLE_PMC(cpu, n)) && 3419 pcd->pcd_allocate_pmc(cpu, adjri, pmc, 3420 &pa) == 0) 3421 break; 3422 } 3423 } else { 3424 /* Process virtual mode */ 3425 for (n = 0; n < (int) md->pmd_npmc; n++) { 3426 pcd = pmc_ri_to_classdep(md, n, &adjri); 3427 if (pmc_can_allocate_row(n, mode) == 0 && 3428 pmc_can_allocate_rowindex( 3429 curthread->td_proc, n, 3430 PMC_CPU_ANY) == 0 && 3431 pcd->pcd_allocate_pmc(curthread->td_oncpu, 3432 adjri, pmc, &pa) == 0) 3433 break; 3434 } 3435 } 3436 3437 #undef PMC_IS_UNALLOCATED 3438 #undef PMC_IS_SHAREABLE_PMC 3439 3440 pmc_restore_cpu_binding(&pb); 3441 3442 if (n == (int) md->pmd_npmc) { 3443 pmc_destroy_pmc_descriptor(pmc); 3444 pmc = NULL; 3445 error = EINVAL; 3446 break; 3447 } 3448 3449 /* Fill in the correct value in the ID field */ 3450 pmc->pm_id = PMC_ID_MAKE_ID(cpu,mode,pa.pm_class,n); 3451 3452 PMCDBG5(PMC,ALL,2, "ev=%d class=%d mode=%d n=%d -> pmcid=%x", 3453 pmc->pm_event, pa.pm_class, mode, n, pmc->pm_id); 3454 3455 /* Process mode PMCs with logging enabled need log files */ 3456 if (pmc->pm_flags & (PMC_F_LOG_PROCEXIT | PMC_F_LOG_PROCCSW)) 3457 pmc->pm_flags |= PMC_F_NEEDS_LOGFILE; 3458 3459 /* All system mode sampling PMCs require a log file */ 3460 if (PMC_IS_SAMPLING_MODE(mode) && PMC_IS_SYSTEM_MODE(mode)) 3461 pmc->pm_flags |= PMC_F_NEEDS_LOGFILE; 3462 3463 /* 3464 * Configure global pmc's immediately 3465 */ 3466 3467 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pmc))) { 3468 3469 pmc_save_cpu_binding(&pb); 3470 pmc_select_cpu(cpu); 3471 3472 phw = pmc_pcpu[cpu]->pc_hwpmcs[n]; 3473 pcd = pmc_ri_to_classdep(md, n, &adjri); 3474 3475 if ((phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0 || 3476 (error = pcd->pcd_config_pmc(cpu, adjri, pmc)) != 0) { 3477 (void) pcd->pcd_release_pmc(cpu, adjri, pmc); 3478 pmc_destroy_pmc_descriptor(pmc); 3479 pmc = NULL; 3480 pmc_restore_cpu_binding(&pb); 3481 error = EPERM; 3482 break; 3483 } 3484 3485 pmc_restore_cpu_binding(&pb); 3486 } 3487 3488 pmc->pm_state = PMC_STATE_ALLOCATED; 3489 3490 /* 3491 * mark row disposition 3492 */ 3493 3494 if (PMC_IS_SYSTEM_MODE(mode)) 3495 PMC_MARK_ROW_STANDALONE(n); 3496 else 3497 PMC_MARK_ROW_THREAD(n); 3498 3499 /* 3500 * Register this PMC with the current thread as its owner. 3501 */ 3502 3503 if ((error = 3504 pmc_register_owner(curthread->td_proc, pmc)) != 0) { 3505 pmc_release_pmc_descriptor(pmc); 3506 pmc_destroy_pmc_descriptor(pmc); 3507 pmc = NULL; 3508 break; 3509 } 3510 3511 /* 3512 * Return the allocated index. 3513 */ 3514 3515 pa.pm_pmcid = pmc->pm_id; 3516 3517 error = copyout(&pa, arg, sizeof(pa)); 3518 } 3519 break; 3520 3521 3522 /* 3523 * Attach a PMC to a process. 3524 */ 3525 3526 case PMC_OP_PMCATTACH: 3527 { 3528 struct pmc *pm; 3529 struct proc *p; 3530 struct pmc_op_pmcattach a; 3531 3532 sx_assert(&pmc_sx, SX_XLOCKED); 3533 3534 if ((error = copyin(arg, &a, sizeof(a))) != 0) 3535 break; 3536 3537 if (a.pm_pid < 0) { 3538 error = EINVAL; 3539 break; 3540 } else if (a.pm_pid == 0) 3541 a.pm_pid = td->td_proc->p_pid; 3542 3543 if ((error = pmc_find_pmc(a.pm_pmc, &pm)) != 0) 3544 break; 3545 3546 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) { 3547 error = EINVAL; 3548 break; 3549 } 3550 3551 /* PMCs may be (re)attached only when allocated or stopped */ 3552 if (pm->pm_state == PMC_STATE_RUNNING) { 3553 error = EBUSY; 3554 break; 3555 } else if (pm->pm_state != PMC_STATE_ALLOCATED && 3556 pm->pm_state != PMC_STATE_STOPPED) { 3557 error = EINVAL; 3558 break; 3559 } 3560 3561 /* lookup pid */ 3562 if ((p = pfind(a.pm_pid)) == NULL) { 3563 error = ESRCH; 3564 break; 3565 } 3566 3567 /* 3568 * Ignore processes that are working on exiting. 3569 */ 3570 if (p->p_flag & P_WEXIT) { 3571 error = ESRCH; 3572 PROC_UNLOCK(p); /* pfind() returns a locked process */ 3573 break; 3574 } 3575 3576 /* 3577 * we are allowed to attach a PMC to a process if 3578 * we can debug it. 3579 */ 3580 error = p_candebug(curthread, p); 3581 3582 PROC_UNLOCK(p); 3583 3584 if (error == 0) 3585 error = pmc_attach_process(p, pm); 3586 } 3587 break; 3588 3589 3590 /* 3591 * Detach an attached PMC from a process. 3592 */ 3593 3594 case PMC_OP_PMCDETACH: 3595 { 3596 struct pmc *pm; 3597 struct proc *p; 3598 struct pmc_op_pmcattach a; 3599 3600 if ((error = copyin(arg, &a, sizeof(a))) != 0) 3601 break; 3602 3603 if (a.pm_pid < 0) { 3604 error = EINVAL; 3605 break; 3606 } else if (a.pm_pid == 0) 3607 a.pm_pid = td->td_proc->p_pid; 3608 3609 if ((error = pmc_find_pmc(a.pm_pmc, &pm)) != 0) 3610 break; 3611 3612 if ((p = pfind(a.pm_pid)) == NULL) { 3613 error = ESRCH; 3614 break; 3615 } 3616 3617 /* 3618 * Treat processes that are in the process of exiting 3619 * as if they were not present. 3620 */ 3621 3622 if (p->p_flag & P_WEXIT) 3623 error = ESRCH; 3624 3625 PROC_UNLOCK(p); /* pfind() returns a locked process */ 3626 3627 if (error == 0) 3628 error = pmc_detach_process(p, pm); 3629 } 3630 break; 3631 3632 3633 /* 3634 * Retrieve the MSR number associated with the counter 3635 * 'pmc_id'. This allows processes to directly use RDPMC 3636 * instructions to read their PMCs, without the overhead of a 3637 * system call. 3638 */ 3639 3640 case PMC_OP_PMCGETMSR: 3641 { 3642 int adjri, ri; 3643 struct pmc *pm; 3644 struct pmc_target *pt; 3645 struct pmc_op_getmsr gm; 3646 struct pmc_classdep *pcd; 3647 3648 PMC_DOWNGRADE_SX(); 3649 3650 if ((error = copyin(arg, &gm, sizeof(gm))) != 0) 3651 break; 3652 3653 if ((error = pmc_find_pmc(gm.pm_pmcid, &pm)) != 0) 3654 break; 3655 3656 /* 3657 * The allocated PMC has to be a process virtual PMC, 3658 * i.e., of type MODE_T[CS]. Global PMCs can only be 3659 * read using the PMCREAD operation since they may be 3660 * allocated on a different CPU than the one we could 3661 * be running on at the time of the RDPMC instruction. 3662 * 3663 * The GETMSR operation is not allowed for PMCs that 3664 * are inherited across processes. 3665 */ 3666 3667 if (!PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)) || 3668 (pm->pm_flags & PMC_F_DESCENDANTS)) { 3669 error = EINVAL; 3670 break; 3671 } 3672 3673 /* 3674 * It only makes sense to use a RDPMC (or its 3675 * equivalent instruction on non-x86 architectures) on 3676 * a process that has allocated and attached a PMC to 3677 * itself. Conversely the PMC is only allowed to have 3678 * one process attached to it -- its owner. 3679 */ 3680 3681 if ((pt = LIST_FIRST(&pm->pm_targets)) == NULL || 3682 LIST_NEXT(pt, pt_next) != NULL || 3683 pt->pt_process->pp_proc != pm->pm_owner->po_owner) { 3684 error = EINVAL; 3685 break; 3686 } 3687 3688 ri = PMC_TO_ROWINDEX(pm); 3689 pcd = pmc_ri_to_classdep(md, ri, &adjri); 3690 3691 /* PMC class has no 'GETMSR' support */ 3692 if (pcd->pcd_get_msr == NULL) { 3693 error = ENOSYS; 3694 break; 3695 } 3696 3697 if ((error = (*pcd->pcd_get_msr)(adjri, &gm.pm_msr)) < 0) 3698 break; 3699 3700 if ((error = copyout(&gm, arg, sizeof(gm))) < 0) 3701 break; 3702 3703 /* 3704 * Mark our process as using MSRs. Update machine 3705 * state using a forced context switch. 3706 */ 3707 3708 pt->pt_process->pp_flags |= PMC_PP_ENABLE_MSR_ACCESS; 3709 pmc_force_context_switch(); 3710 3711 } 3712 break; 3713 3714 /* 3715 * Release an allocated PMC 3716 */ 3717 3718 case PMC_OP_PMCRELEASE: 3719 { 3720 pmc_id_t pmcid; 3721 struct pmc *pm; 3722 struct pmc_owner *po; 3723 struct pmc_op_simple sp; 3724 3725 /* 3726 * Find PMC pointer for the named PMC. 3727 * 3728 * Use pmc_release_pmc_descriptor() to switch off the 3729 * PMC, remove all its target threads, and remove the 3730 * PMC from its owner's list. 3731 * 3732 * Remove the owner record if this is the last PMC 3733 * owned. 3734 * 3735 * Free up space. 3736 */ 3737 3738 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 3739 break; 3740 3741 pmcid = sp.pm_pmcid; 3742 3743 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 3744 break; 3745 3746 po = pm->pm_owner; 3747 pmc_release_pmc_descriptor(pm); 3748 pmc_maybe_remove_owner(po); 3749 pmc_destroy_pmc_descriptor(pm); 3750 } 3751 break; 3752 3753 3754 /* 3755 * Read and/or write a PMC. 3756 */ 3757 3758 case PMC_OP_PMCRW: 3759 { 3760 int adjri; 3761 struct pmc *pm; 3762 uint32_t cpu, ri; 3763 pmc_value_t oldvalue; 3764 struct pmc_binding pb; 3765 struct pmc_op_pmcrw prw; 3766 struct pmc_classdep *pcd; 3767 struct pmc_op_pmcrw *pprw; 3768 3769 PMC_DOWNGRADE_SX(); 3770 3771 if ((error = copyin(arg, &prw, sizeof(prw))) != 0) 3772 break; 3773 3774 ri = 0; 3775 PMCDBG2(PMC,OPS,1, "rw id=%d flags=0x%x", prw.pm_pmcid, 3776 prw.pm_flags); 3777 3778 /* must have at least one flag set */ 3779 if ((prw.pm_flags & (PMC_F_OLDVALUE|PMC_F_NEWVALUE)) == 0) { 3780 error = EINVAL; 3781 break; 3782 } 3783 3784 /* locate pmc descriptor */ 3785 if ((error = pmc_find_pmc(prw.pm_pmcid, &pm)) != 0) 3786 break; 3787 3788 /* Can't read a PMC that hasn't been started. */ 3789 if (pm->pm_state != PMC_STATE_ALLOCATED && 3790 pm->pm_state != PMC_STATE_STOPPED && 3791 pm->pm_state != PMC_STATE_RUNNING) { 3792 error = EINVAL; 3793 break; 3794 } 3795 3796 /* writing a new value is allowed only for 'STOPPED' pmcs */ 3797 if (pm->pm_state == PMC_STATE_RUNNING && 3798 (prw.pm_flags & PMC_F_NEWVALUE)) { 3799 error = EBUSY; 3800 break; 3801 } 3802 3803 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) { 3804 3805 /* 3806 * If this PMC is attached to its owner (i.e., 3807 * the process requesting this operation) and 3808 * is running, then attempt to get an 3809 * upto-date reading from hardware for a READ. 3810 * Writes are only allowed when the PMC is 3811 * stopped, so only update the saved value 3812 * field. 3813 * 3814 * If the PMC is not running, or is not 3815 * attached to its owner, read/write to the 3816 * savedvalue field. 3817 */ 3818 3819 ri = PMC_TO_ROWINDEX(pm); 3820 pcd = pmc_ri_to_classdep(md, ri, &adjri); 3821 3822 mtx_pool_lock_spin(pmc_mtxpool, pm); 3823 cpu = curthread->td_oncpu; 3824 3825 if (prw.pm_flags & PMC_F_OLDVALUE) { 3826 if ((pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) && 3827 (pm->pm_state == PMC_STATE_RUNNING)) 3828 error = (*pcd->pcd_read_pmc)(cpu, adjri, 3829 &oldvalue); 3830 else 3831 oldvalue = pm->pm_gv.pm_savedvalue; 3832 } 3833 if (prw.pm_flags & PMC_F_NEWVALUE) 3834 pm->pm_gv.pm_savedvalue = prw.pm_value; 3835 3836 mtx_pool_unlock_spin(pmc_mtxpool, pm); 3837 3838 } else { /* System mode PMCs */ 3839 cpu = PMC_TO_CPU(pm); 3840 ri = PMC_TO_ROWINDEX(pm); 3841 pcd = pmc_ri_to_classdep(md, ri, &adjri); 3842 3843 if (!pmc_cpu_is_active(cpu)) { 3844 error = ENXIO; 3845 break; 3846 } 3847 3848 /* move this thread to CPU 'cpu' */ 3849 pmc_save_cpu_binding(&pb); 3850 pmc_select_cpu(cpu); 3851 3852 critical_enter(); 3853 /* save old value */ 3854 if (prw.pm_flags & PMC_F_OLDVALUE) 3855 if ((error = (*pcd->pcd_read_pmc)(cpu, adjri, 3856 &oldvalue))) 3857 goto error; 3858 /* write out new value */ 3859 if (prw.pm_flags & PMC_F_NEWVALUE) 3860 error = (*pcd->pcd_write_pmc)(cpu, adjri, 3861 prw.pm_value); 3862 error: 3863 critical_exit(); 3864 pmc_restore_cpu_binding(&pb); 3865 if (error) 3866 break; 3867 } 3868 3869 pprw = (struct pmc_op_pmcrw *) arg; 3870 3871 #ifdef HWPMC_DEBUG 3872 if (prw.pm_flags & PMC_F_NEWVALUE) 3873 PMCDBG3(PMC,OPS,2, "rw id=%d new %jx -> old %jx", 3874 ri, prw.pm_value, oldvalue); 3875 else if (prw.pm_flags & PMC_F_OLDVALUE) 3876 PMCDBG2(PMC,OPS,2, "rw id=%d -> old %jx", ri, oldvalue); 3877 #endif 3878 3879 /* return old value if requested */ 3880 if (prw.pm_flags & PMC_F_OLDVALUE) 3881 if ((error = copyout(&oldvalue, &pprw->pm_value, 3882 sizeof(prw.pm_value)))) 3883 break; 3884 3885 } 3886 break; 3887 3888 3889 /* 3890 * Set the sampling rate for a sampling mode PMC and the 3891 * initial count for a counting mode PMC. 3892 */ 3893 3894 case PMC_OP_PMCSETCOUNT: 3895 { 3896 struct pmc *pm; 3897 struct pmc_op_pmcsetcount sc; 3898 3899 PMC_DOWNGRADE_SX(); 3900 3901 if ((error = copyin(arg, &sc, sizeof(sc))) != 0) 3902 break; 3903 3904 if ((error = pmc_find_pmc(sc.pm_pmcid, &pm)) != 0) 3905 break; 3906 3907 if (pm->pm_state == PMC_STATE_RUNNING) { 3908 error = EBUSY; 3909 break; 3910 } 3911 3912 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 3913 pm->pm_sc.pm_reloadcount = sc.pm_count; 3914 else 3915 pm->pm_sc.pm_initial = sc.pm_count; 3916 } 3917 break; 3918 3919 3920 /* 3921 * Start a PMC. 3922 */ 3923 3924 case PMC_OP_PMCSTART: 3925 { 3926 pmc_id_t pmcid; 3927 struct pmc *pm; 3928 struct pmc_op_simple sp; 3929 3930 sx_assert(&pmc_sx, SX_XLOCKED); 3931 3932 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 3933 break; 3934 3935 pmcid = sp.pm_pmcid; 3936 3937 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 3938 break; 3939 3940 KASSERT(pmcid == pm->pm_id, 3941 ("[pmc,%d] pmcid %x != id %x", __LINE__, 3942 pm->pm_id, pmcid)); 3943 3944 if (pm->pm_state == PMC_STATE_RUNNING) /* already running */ 3945 break; 3946 else if (pm->pm_state != PMC_STATE_STOPPED && 3947 pm->pm_state != PMC_STATE_ALLOCATED) { 3948 error = EINVAL; 3949 break; 3950 } 3951 3952 error = pmc_start(pm); 3953 } 3954 break; 3955 3956 3957 /* 3958 * Stop a PMC. 3959 */ 3960 3961 case PMC_OP_PMCSTOP: 3962 { 3963 pmc_id_t pmcid; 3964 struct pmc *pm; 3965 struct pmc_op_simple sp; 3966 3967 PMC_DOWNGRADE_SX(); 3968 3969 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 3970 break; 3971 3972 pmcid = sp.pm_pmcid; 3973 3974 /* 3975 * Mark the PMC as inactive and invoke the MD stop 3976 * routines if needed. 3977 */ 3978 3979 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 3980 break; 3981 3982 KASSERT(pmcid == pm->pm_id, 3983 ("[pmc,%d] pmc id %x != pmcid %x", __LINE__, 3984 pm->pm_id, pmcid)); 3985 3986 if (pm->pm_state == PMC_STATE_STOPPED) /* already stopped */ 3987 break; 3988 else if (pm->pm_state != PMC_STATE_RUNNING) { 3989 error = EINVAL; 3990 break; 3991 } 3992 3993 error = pmc_stop(pm); 3994 } 3995 break; 3996 3997 3998 /* 3999 * Write a user supplied value to the log file. 4000 */ 4001 4002 case PMC_OP_WRITELOG: 4003 { 4004 struct pmc_op_writelog wl; 4005 struct pmc_owner *po; 4006 4007 PMC_DOWNGRADE_SX(); 4008 4009 if ((error = copyin(arg, &wl, sizeof(wl))) != 0) 4010 break; 4011 4012 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 4013 error = EINVAL; 4014 break; 4015 } 4016 4017 if ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) { 4018 error = EINVAL; 4019 break; 4020 } 4021 4022 error = pmclog_process_userlog(po, &wl); 4023 } 4024 break; 4025 4026 4027 default: 4028 error = EINVAL; 4029 break; 4030 } 4031 4032 if (is_sx_locked != 0) { 4033 if (is_sx_downgraded) 4034 sx_sunlock(&pmc_sx); 4035 else 4036 sx_xunlock(&pmc_sx); 4037 } 4038 4039 if (error) 4040 atomic_add_int(&pmc_stats.pm_syscall_errors, 1); 4041 4042 PICKUP_GIANT(); 4043 4044 return error; 4045 } 4046 4047 /* 4048 * Helper functions 4049 */ 4050 4051 4052 /* 4053 * Mark the thread as needing callchain capture and post an AST. The 4054 * actual callchain capture will be done in a context where it is safe 4055 * to take page faults. 4056 */ 4057 4058 static void 4059 pmc_post_callchain_callback(void) 4060 { 4061 struct thread *td; 4062 4063 td = curthread; 4064 4065 /* 4066 * If there is multiple PMCs for the same interrupt ignore new post 4067 */ 4068 if (td->td_pflags & TDP_CALLCHAIN) 4069 return; 4070 4071 /* 4072 * Mark this thread as needing callchain capture. 4073 * `td->td_pflags' will be safe to touch because this thread 4074 * was in user space when it was interrupted. 4075 */ 4076 td->td_pflags |= TDP_CALLCHAIN; 4077 4078 /* 4079 * Don't let this thread migrate between CPUs until callchain 4080 * capture completes. 4081 */ 4082 sched_pin(); 4083 4084 return; 4085 } 4086 4087 /* 4088 * Interrupt processing. 4089 * 4090 * Find a free slot in the per-cpu array of samples and capture the 4091 * current callchain there. If a sample was successfully added, a bit 4092 * is set in mask 'pmc_cpumask' denoting that the DO_SAMPLES hook 4093 * needs to be invoked from the clock handler. 4094 * 4095 * This function is meant to be called from an NMI handler. It cannot 4096 * use any of the locking primitives supplied by the OS. 4097 */ 4098 4099 int 4100 pmc_process_interrupt(int cpu, int ring, struct pmc *pm, struct trapframe *tf, 4101 int inuserspace) 4102 { 4103 int error, callchaindepth; 4104 struct thread *td; 4105 struct pmc_sample *ps; 4106 struct pmc_samplebuffer *psb; 4107 4108 error = 0; 4109 4110 /* 4111 * Allocate space for a sample buffer. 4112 */ 4113 psb = pmc_pcpu[cpu]->pc_sb[ring]; 4114 4115 ps = psb->ps_write; 4116 if (ps->ps_nsamples) { /* in use, reader hasn't caught up */ 4117 CPU_SET_ATOMIC(cpu, &pm->pm_stalled); 4118 atomic_add_int(&pmc_stats.pm_intr_bufferfull, 1); 4119 PMCDBG6(SAM,INT,1,"(spc) cpu=%d pm=%p tf=%p um=%d wr=%d rd=%d", 4120 cpu, pm, (void *) tf, inuserspace, 4121 (int) (psb->ps_write - psb->ps_samples), 4122 (int) (psb->ps_read - psb->ps_samples)); 4123 callchaindepth = 1; 4124 error = ENOMEM; 4125 goto done; 4126 } 4127 4128 4129 /* Fill in entry. */ 4130 PMCDBG6(SAM,INT,1,"cpu=%d pm=%p tf=%p um=%d wr=%d rd=%d", cpu, pm, 4131 (void *) tf, inuserspace, 4132 (int) (psb->ps_write - psb->ps_samples), 4133 (int) (psb->ps_read - psb->ps_samples)); 4134 4135 KASSERT(pm->pm_runcount >= 0, 4136 ("[pmc,%d] pm=%p runcount %d", __LINE__, (void *) pm, 4137 pm->pm_runcount)); 4138 4139 atomic_add_rel_int(&pm->pm_runcount, 1); /* hold onto PMC */ 4140 4141 ps->ps_pmc = pm; 4142 if ((td = curthread) && td->td_proc) 4143 ps->ps_pid = td->td_proc->p_pid; 4144 else 4145 ps->ps_pid = -1; 4146 ps->ps_cpu = cpu; 4147 ps->ps_td = td; 4148 ps->ps_flags = inuserspace ? PMC_CC_F_USERSPACE : 0; 4149 4150 callchaindepth = (pm->pm_flags & PMC_F_CALLCHAIN) ? 4151 pmc_callchaindepth : 1; 4152 4153 if (callchaindepth == 1) 4154 ps->ps_pc[0] = PMC_TRAPFRAME_TO_PC(tf); 4155 else { 4156 /* 4157 * Kernel stack traversals can be done immediately, 4158 * while we defer to an AST for user space traversals. 4159 */ 4160 if (!inuserspace) { 4161 callchaindepth = 4162 pmc_save_kernel_callchain(ps->ps_pc, 4163 callchaindepth, tf); 4164 } else { 4165 pmc_post_callchain_callback(); 4166 callchaindepth = PMC_SAMPLE_INUSE; 4167 } 4168 } 4169 4170 ps->ps_nsamples = callchaindepth; /* mark entry as in use */ 4171 4172 /* increment write pointer, modulo ring buffer size */ 4173 ps++; 4174 if (ps == psb->ps_fence) 4175 psb->ps_write = psb->ps_samples; 4176 else 4177 psb->ps_write = ps; 4178 4179 done: 4180 /* mark CPU as needing processing */ 4181 if (callchaindepth != PMC_SAMPLE_INUSE) 4182 CPU_SET_ATOMIC(cpu, &pmc_cpumask); 4183 4184 return (error); 4185 } 4186 4187 /* 4188 * Capture a user call chain. This function will be called from ast() 4189 * before control returns to userland and before the process gets 4190 * rescheduled. 4191 */ 4192 4193 static void 4194 pmc_capture_user_callchain(int cpu, int ring, struct trapframe *tf) 4195 { 4196 struct pmc *pm; 4197 struct thread *td; 4198 struct pmc_sample *ps, *ps_end; 4199 struct pmc_samplebuffer *psb; 4200 #ifdef INVARIANTS 4201 int ncallchains; 4202 #endif 4203 4204 psb = pmc_pcpu[cpu]->pc_sb[ring]; 4205 td = curthread; 4206 4207 KASSERT(td->td_pflags & TDP_CALLCHAIN, 4208 ("[pmc,%d] Retrieving callchain for thread that doesn't want it", 4209 __LINE__)); 4210 4211 #ifdef INVARIANTS 4212 ncallchains = 0; 4213 #endif 4214 4215 /* 4216 * Iterate through all deferred callchain requests. 4217 * Walk from the current read pointer to the current 4218 * write pointer. 4219 */ 4220 4221 ps = psb->ps_read; 4222 ps_end = psb->ps_write; 4223 do { 4224 if (ps->ps_nsamples != PMC_SAMPLE_INUSE) 4225 goto next; 4226 if (ps->ps_td != td) 4227 goto next; 4228 4229 KASSERT(ps->ps_cpu == cpu, 4230 ("[pmc,%d] cpu mismatch ps_cpu=%d pcpu=%d", __LINE__, 4231 ps->ps_cpu, PCPU_GET(cpuid))); 4232 4233 pm = ps->ps_pmc; 4234 4235 KASSERT(pm->pm_flags & PMC_F_CALLCHAIN, 4236 ("[pmc,%d] Retrieving callchain for PMC that doesn't " 4237 "want it", __LINE__)); 4238 4239 KASSERT(pm->pm_runcount > 0, 4240 ("[pmc,%d] runcount %d", __LINE__, pm->pm_runcount)); 4241 4242 /* 4243 * Retrieve the callchain and mark the sample buffer 4244 * as 'processable' by the timer tick sweep code. 4245 */ 4246 ps->ps_nsamples = pmc_save_user_callchain(ps->ps_pc, 4247 pmc_callchaindepth, tf); 4248 4249 #ifdef INVARIANTS 4250 ncallchains++; 4251 #endif 4252 4253 next: 4254 /* increment the pointer, modulo sample ring size */ 4255 if (++ps == psb->ps_fence) 4256 ps = psb->ps_samples; 4257 } while (ps != ps_end); 4258 4259 KASSERT(ncallchains > 0, 4260 ("[pmc,%d] cpu %d didn't find a sample to collect", __LINE__, 4261 cpu)); 4262 4263 KASSERT(td->td_pinned == 1, 4264 ("[pmc,%d] invalid td_pinned value", __LINE__)); 4265 sched_unpin(); /* Can migrate safely now. */ 4266 4267 /* mark CPU as needing processing */ 4268 CPU_SET_ATOMIC(cpu, &pmc_cpumask); 4269 4270 return; 4271 } 4272 4273 /* 4274 * Process saved PC samples. 4275 */ 4276 4277 static void 4278 pmc_process_samples(int cpu, int ring) 4279 { 4280 struct pmc *pm; 4281 int adjri, n; 4282 struct thread *td; 4283 struct pmc_owner *po; 4284 struct pmc_sample *ps; 4285 struct pmc_classdep *pcd; 4286 struct pmc_samplebuffer *psb; 4287 4288 KASSERT(PCPU_GET(cpuid) == cpu, 4289 ("[pmc,%d] not on the correct CPU pcpu=%d cpu=%d", __LINE__, 4290 PCPU_GET(cpuid), cpu)); 4291 4292 psb = pmc_pcpu[cpu]->pc_sb[ring]; 4293 4294 for (n = 0; n < pmc_nsamples; n++) { /* bound on #iterations */ 4295 4296 ps = psb->ps_read; 4297 if (ps->ps_nsamples == PMC_SAMPLE_FREE) 4298 break; 4299 4300 pm = ps->ps_pmc; 4301 4302 KASSERT(pm->pm_runcount > 0, 4303 ("[pmc,%d] pm=%p runcount %d", __LINE__, (void *) pm, 4304 pm->pm_runcount)); 4305 4306 po = pm->pm_owner; 4307 4308 KASSERT(PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)), 4309 ("[pmc,%d] pmc=%p non-sampling mode=%d", __LINE__, 4310 pm, PMC_TO_MODE(pm))); 4311 4312 /* Ignore PMCs that have been switched off */ 4313 if (pm->pm_state != PMC_STATE_RUNNING) 4314 goto entrydone; 4315 4316 /* If there is a pending AST wait for completion */ 4317 if (ps->ps_nsamples == PMC_SAMPLE_INUSE) { 4318 /* Need a rescan at a later time. */ 4319 CPU_SET_ATOMIC(cpu, &pmc_cpumask); 4320 break; 4321 } 4322 4323 PMCDBG6(SAM,OPS,1,"cpu=%d pm=%p n=%d fl=%x wr=%d rd=%d", cpu, 4324 pm, ps->ps_nsamples, ps->ps_flags, 4325 (int) (psb->ps_write - psb->ps_samples), 4326 (int) (psb->ps_read - psb->ps_samples)); 4327 4328 /* 4329 * If this is a process-mode PMC that is attached to 4330 * its owner, and if the PC is in user mode, update 4331 * profiling statistics like timer-based profiling 4332 * would have done. 4333 */ 4334 if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) { 4335 if (ps->ps_flags & PMC_CC_F_USERSPACE) { 4336 td = FIRST_THREAD_IN_PROC(po->po_owner); 4337 addupc_intr(td, ps->ps_pc[0], 1); 4338 } 4339 goto entrydone; 4340 } 4341 4342 /* 4343 * Otherwise, this is either a sampling mode PMC that 4344 * is attached to a different process than its owner, 4345 * or a system-wide sampling PMC. Dispatch a log 4346 * entry to the PMC's owner process. 4347 */ 4348 pmclog_process_callchain(pm, ps); 4349 4350 entrydone: 4351 ps->ps_nsamples = 0; /* mark entry as free */ 4352 atomic_subtract_rel_int(&pm->pm_runcount, 1); 4353 4354 /* increment read pointer, modulo sample size */ 4355 if (++ps == psb->ps_fence) 4356 psb->ps_read = psb->ps_samples; 4357 else 4358 psb->ps_read = ps; 4359 } 4360 4361 atomic_add_int(&pmc_stats.pm_log_sweeps, 1); 4362 4363 /* Do not re-enable stalled PMCs if we failed to process any samples */ 4364 if (n == 0) 4365 return; 4366 4367 /* 4368 * Restart any stalled sampling PMCs on this CPU. 4369 * 4370 * If the NMI handler sets the pm_stalled field of a PMC after 4371 * the check below, we'll end up processing the stalled PMC at 4372 * the next hardclock tick. 4373 */ 4374 for (n = 0; n < md->pmd_npmc; n++) { 4375 pcd = pmc_ri_to_classdep(md, n, &adjri); 4376 KASSERT(pcd != NULL, 4377 ("[pmc,%d] null pcd ri=%d", __LINE__, n)); 4378 (void) (*pcd->pcd_get_config)(cpu,adjri,&pm); 4379 4380 if (pm == NULL || /* !cfg'ed */ 4381 pm->pm_state != PMC_STATE_RUNNING || /* !active */ 4382 !PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)) || /* !sampling */ 4383 !CPU_ISSET(cpu, &pm->pm_cpustate) || /* !desired */ 4384 !CPU_ISSET(cpu, &pm->pm_stalled)) /* !stalled */ 4385 continue; 4386 4387 CPU_CLR_ATOMIC(cpu, &pm->pm_stalled); 4388 (*pcd->pcd_start_pmc)(cpu, adjri); 4389 } 4390 } 4391 4392 /* 4393 * Event handlers. 4394 */ 4395 4396 /* 4397 * Handle a process exit. 4398 * 4399 * Remove this process from all hash tables. If this process 4400 * owned any PMCs, turn off those PMCs and deallocate them, 4401 * removing any associations with target processes. 4402 * 4403 * This function will be called by the last 'thread' of a 4404 * process. 4405 * 4406 * XXX This eventhandler gets called early in the exit process. 4407 * Consider using a 'hook' invocation from thread_exit() or equivalent 4408 * spot. Another negative is that kse_exit doesn't seem to call 4409 * exit1() [??]. 4410 * 4411 */ 4412 4413 static void 4414 pmc_process_exit(void *arg __unused, struct proc *p) 4415 { 4416 struct pmc *pm; 4417 int adjri, cpu; 4418 unsigned int ri; 4419 int is_using_hwpmcs; 4420 struct pmc_owner *po; 4421 struct pmc_process *pp; 4422 struct pmc_classdep *pcd; 4423 pmc_value_t newvalue, tmp; 4424 4425 PROC_LOCK(p); 4426 is_using_hwpmcs = p->p_flag & P_HWPMC; 4427 PROC_UNLOCK(p); 4428 4429 /* 4430 * Log a sysexit event to all SS PMC owners. 4431 */ 4432 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 4433 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 4434 pmclog_process_sysexit(po, p->p_pid); 4435 4436 if (!is_using_hwpmcs) 4437 return; 4438 4439 PMC_GET_SX_XLOCK(); 4440 PMCDBG3(PRC,EXT,1,"process-exit proc=%p (%d, %s)", p, p->p_pid, 4441 p->p_comm); 4442 4443 /* 4444 * Since this code is invoked by the last thread in an exiting 4445 * process, we would have context switched IN at some prior 4446 * point. However, with PREEMPTION, kernel mode context 4447 * switches may happen any time, so we want to disable a 4448 * context switch OUT till we get any PMCs targeting this 4449 * process off the hardware. 4450 * 4451 * We also need to atomically remove this process' 4452 * entry from our target process hash table, using 4453 * PMC_FLAG_REMOVE. 4454 */ 4455 PMCDBG3(PRC,EXT,1, "process-exit proc=%p (%d, %s)", p, p->p_pid, 4456 p->p_comm); 4457 4458 critical_enter(); /* no preemption */ 4459 4460 cpu = curthread->td_oncpu; 4461 4462 if ((pp = pmc_find_process_descriptor(p, 4463 PMC_FLAG_REMOVE)) != NULL) { 4464 4465 PMCDBG2(PRC,EXT,2, 4466 "process-exit proc=%p pmc-process=%p", p, pp); 4467 4468 /* 4469 * The exiting process could the target of 4470 * some PMCs which will be running on 4471 * currently executing CPU. 4472 * 4473 * We need to turn these PMCs off like we 4474 * would do at context switch OUT time. 4475 */ 4476 for (ri = 0; ri < md->pmd_npmc; ri++) { 4477 4478 /* 4479 * Pick up the pmc pointer from hardware 4480 * state similar to the CSW_OUT code. 4481 */ 4482 pm = NULL; 4483 4484 pcd = pmc_ri_to_classdep(md, ri, &adjri); 4485 4486 (void) (*pcd->pcd_get_config)(cpu, adjri, &pm); 4487 4488 PMCDBG2(PRC,EXT,2, "ri=%d pm=%p", ri, pm); 4489 4490 if (pm == NULL || 4491 !PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) 4492 continue; 4493 4494 PMCDBG4(PRC,EXT,2, "ppmcs[%d]=%p pm=%p " 4495 "state=%d", ri, pp->pp_pmcs[ri].pp_pmc, 4496 pm, pm->pm_state); 4497 4498 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 4499 ("[pmc,%d] ri mismatch pmc(%d) ri(%d)", 4500 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 4501 4502 KASSERT(pm == pp->pp_pmcs[ri].pp_pmc, 4503 ("[pmc,%d] pm %p != pp_pmcs[%d] %p", 4504 __LINE__, pm, ri, pp->pp_pmcs[ri].pp_pmc)); 4505 4506 KASSERT(pm->pm_runcount > 0, 4507 ("[pmc,%d] bad runcount ri %d rc %d", 4508 __LINE__, ri, pm->pm_runcount)); 4509 4510 /* 4511 * Change desired state, and then stop if not 4512 * stalled. This two-step dance should avoid 4513 * race conditions where an interrupt re-enables 4514 * the PMC after this code has already checked 4515 * the pm_stalled flag. 4516 */ 4517 if (CPU_ISSET(cpu, &pm->pm_cpustate)) { 4518 CPU_CLR_ATOMIC(cpu, &pm->pm_cpustate); 4519 if (!CPU_ISSET(cpu, &pm->pm_stalled)) { 4520 (void) pcd->pcd_stop_pmc(cpu, adjri); 4521 pcd->pcd_read_pmc(cpu, adjri, 4522 &newvalue); 4523 tmp = newvalue - 4524 PMC_PCPU_SAVED(cpu,ri); 4525 4526 mtx_pool_lock_spin(pmc_mtxpool, pm); 4527 pm->pm_gv.pm_savedvalue += tmp; 4528 pp->pp_pmcs[ri].pp_pmcval += tmp; 4529 mtx_pool_unlock_spin(pmc_mtxpool, pm); 4530 } 4531 } 4532 4533 atomic_subtract_rel_int(&pm->pm_runcount,1); 4534 4535 KASSERT((int) pm->pm_runcount >= 0, 4536 ("[pmc,%d] runcount is %d", __LINE__, ri)); 4537 4538 (void) pcd->pcd_config_pmc(cpu, adjri, NULL); 4539 } 4540 4541 /* 4542 * Inform the MD layer of this pseudo "context switch 4543 * out" 4544 */ 4545 (void) md->pmd_switch_out(pmc_pcpu[cpu], pp); 4546 4547 critical_exit(); /* ok to be pre-empted now */ 4548 4549 /* 4550 * Unlink this process from the PMCs that are 4551 * targeting it. This will send a signal to 4552 * all PMC owner's whose PMCs are orphaned. 4553 * 4554 * Log PMC value at exit time if requested. 4555 */ 4556 for (ri = 0; ri < md->pmd_npmc; ri++) 4557 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) { 4558 if (pm->pm_flags & PMC_F_NEEDS_LOGFILE && 4559 PMC_IS_COUNTING_MODE(PMC_TO_MODE(pm))) 4560 pmclog_process_procexit(pm, pp); 4561 pmc_unlink_target_process(pm, pp); 4562 } 4563 free(pp, M_PMC); 4564 4565 } else 4566 critical_exit(); /* pp == NULL */ 4567 4568 4569 /* 4570 * If the process owned PMCs, free them up and free up 4571 * memory. 4572 */ 4573 if ((po = pmc_find_owner_descriptor(p)) != NULL) { 4574 pmc_remove_owner(po); 4575 pmc_destroy_owner_descriptor(po); 4576 } 4577 4578 sx_xunlock(&pmc_sx); 4579 } 4580 4581 /* 4582 * Handle a process fork. 4583 * 4584 * If the parent process 'p1' is under HWPMC monitoring, then copy 4585 * over any attached PMCs that have 'do_descendants' semantics. 4586 */ 4587 4588 static void 4589 pmc_process_fork(void *arg __unused, struct proc *p1, struct proc *newproc, 4590 int flags) 4591 { 4592 int is_using_hwpmcs; 4593 unsigned int ri; 4594 uint32_t do_descendants; 4595 struct pmc *pm; 4596 struct pmc_owner *po; 4597 struct pmc_process *ppnew, *ppold; 4598 4599 (void) flags; /* unused parameter */ 4600 4601 PROC_LOCK(p1); 4602 is_using_hwpmcs = p1->p_flag & P_HWPMC; 4603 PROC_UNLOCK(p1); 4604 4605 /* 4606 * If there are system-wide sampling PMCs active, we need to 4607 * log all fork events to their owner's logs. 4608 */ 4609 4610 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 4611 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 4612 pmclog_process_procfork(po, p1->p_pid, newproc->p_pid); 4613 4614 if (!is_using_hwpmcs) 4615 return; 4616 4617 PMC_GET_SX_XLOCK(); 4618 PMCDBG4(PMC,FRK,1, "process-fork proc=%p (%d, %s) -> %p", p1, 4619 p1->p_pid, p1->p_comm, newproc); 4620 4621 /* 4622 * If the parent process (curthread->td_proc) is a 4623 * target of any PMCs, look for PMCs that are to be 4624 * inherited, and link these into the new process 4625 * descriptor. 4626 */ 4627 if ((ppold = pmc_find_process_descriptor(curthread->td_proc, 4628 PMC_FLAG_NONE)) == NULL) 4629 goto done; /* nothing to do */ 4630 4631 do_descendants = 0; 4632 for (ri = 0; ri < md->pmd_npmc; ri++) 4633 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL) 4634 do_descendants |= pm->pm_flags & PMC_F_DESCENDANTS; 4635 if (do_descendants == 0) /* nothing to do */ 4636 goto done; 4637 4638 /* allocate a descriptor for the new process */ 4639 if ((ppnew = pmc_find_process_descriptor(newproc, 4640 PMC_FLAG_ALLOCATE)) == NULL) 4641 goto done; 4642 4643 /* 4644 * Run through all PMCs that were targeting the old process 4645 * and which specified F_DESCENDANTS and attach them to the 4646 * new process. 4647 * 4648 * Log the fork event to all owners of PMCs attached to this 4649 * process, if not already logged. 4650 */ 4651 for (ri = 0; ri < md->pmd_npmc; ri++) 4652 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL && 4653 (pm->pm_flags & PMC_F_DESCENDANTS)) { 4654 pmc_link_target_process(pm, ppnew); 4655 po = pm->pm_owner; 4656 if (po->po_sscount == 0 && 4657 po->po_flags & PMC_PO_OWNS_LOGFILE) 4658 pmclog_process_procfork(po, p1->p_pid, 4659 newproc->p_pid); 4660 } 4661 4662 /* 4663 * Now mark the new process as being tracked by this driver. 4664 */ 4665 PROC_LOCK(newproc); 4666 newproc->p_flag |= P_HWPMC; 4667 PROC_UNLOCK(newproc); 4668 4669 done: 4670 sx_xunlock(&pmc_sx); 4671 } 4672 4673 static void 4674 pmc_kld_load(void *arg __unused, linker_file_t lf) 4675 { 4676 struct pmc_owner *po; 4677 4678 sx_slock(&pmc_sx); 4679 4680 /* 4681 * Notify owners of system sampling PMCs about KLD operations. 4682 */ 4683 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 4684 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 4685 pmclog_process_map_in(po, (pid_t) -1, 4686 (uintfptr_t) lf->address, lf->filename); 4687 4688 /* 4689 * TODO: Notify owners of (all) process-sampling PMCs too. 4690 */ 4691 4692 sx_sunlock(&pmc_sx); 4693 } 4694 4695 static void 4696 pmc_kld_unload(void *arg __unused, const char *filename __unused, 4697 caddr_t address, size_t size) 4698 { 4699 struct pmc_owner *po; 4700 4701 sx_slock(&pmc_sx); 4702 4703 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 4704 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 4705 pmclog_process_map_out(po, (pid_t) -1, 4706 (uintfptr_t) address, (uintfptr_t) address + size); 4707 4708 /* 4709 * TODO: Notify owners of process-sampling PMCs. 4710 */ 4711 4712 sx_sunlock(&pmc_sx); 4713 } 4714 4715 /* 4716 * initialization 4717 */ 4718 static const char * 4719 pmc_name_of_pmcclass(enum pmc_class class) 4720 { 4721 4722 switch (class) { 4723 #undef __PMC_CLASS 4724 #define __PMC_CLASS(S,V,D) \ 4725 case PMC_CLASS_##S: \ 4726 return #S; 4727 __PMC_CLASSES(); 4728 default: 4729 return ("<unknown>"); 4730 } 4731 } 4732 4733 /* 4734 * Base class initializer: allocate structure and set default classes. 4735 */ 4736 struct pmc_mdep * 4737 pmc_mdep_alloc(int nclasses) 4738 { 4739 struct pmc_mdep *md; 4740 int n; 4741 4742 /* SOFT + md classes */ 4743 n = 1 + nclasses; 4744 md = malloc(sizeof(struct pmc_mdep) + n * 4745 sizeof(struct pmc_classdep), M_PMC, M_WAITOK|M_ZERO); 4746 md->pmd_nclass = n; 4747 4748 /* Add base class. */ 4749 pmc_soft_initialize(md); 4750 return md; 4751 } 4752 4753 void 4754 pmc_mdep_free(struct pmc_mdep *md) 4755 { 4756 pmc_soft_finalize(md); 4757 free(md, M_PMC); 4758 } 4759 4760 static int 4761 generic_switch_in(struct pmc_cpu *pc, struct pmc_process *pp) 4762 { 4763 (void) pc; (void) pp; 4764 4765 return (0); 4766 } 4767 4768 static int 4769 generic_switch_out(struct pmc_cpu *pc, struct pmc_process *pp) 4770 { 4771 (void) pc; (void) pp; 4772 4773 return (0); 4774 } 4775 4776 static struct pmc_mdep * 4777 pmc_generic_cpu_initialize(void) 4778 { 4779 struct pmc_mdep *md; 4780 4781 md = pmc_mdep_alloc(0); 4782 4783 md->pmd_cputype = PMC_CPU_GENERIC; 4784 4785 md->pmd_pcpu_init = NULL; 4786 md->pmd_pcpu_fini = NULL; 4787 md->pmd_switch_in = generic_switch_in; 4788 md->pmd_switch_out = generic_switch_out; 4789 4790 return (md); 4791 } 4792 4793 static void 4794 pmc_generic_cpu_finalize(struct pmc_mdep *md) 4795 { 4796 (void) md; 4797 } 4798 4799 4800 static int 4801 pmc_initialize(void) 4802 { 4803 int c, cpu, error, n, ri; 4804 unsigned int maxcpu; 4805 struct pmc_binding pb; 4806 struct pmc_sample *ps; 4807 struct pmc_classdep *pcd; 4808 struct pmc_samplebuffer *sb; 4809 4810 md = NULL; 4811 error = 0; 4812 4813 #ifdef HWPMC_DEBUG 4814 /* parse debug flags first */ 4815 if (TUNABLE_STR_FETCH(PMC_SYSCTL_NAME_PREFIX "debugflags", 4816 pmc_debugstr, sizeof(pmc_debugstr))) 4817 pmc_debugflags_parse(pmc_debugstr, 4818 pmc_debugstr+strlen(pmc_debugstr)); 4819 #endif 4820 4821 PMCDBG1(MOD,INI,0, "PMC Initialize (version %x)", PMC_VERSION); 4822 4823 /* check kernel version */ 4824 if (pmc_kernel_version != PMC_VERSION) { 4825 if (pmc_kernel_version == 0) 4826 printf("hwpmc: this kernel has not been compiled with " 4827 "'options HWPMC_HOOKS'.\n"); 4828 else 4829 printf("hwpmc: kernel version (0x%x) does not match " 4830 "module version (0x%x).\n", pmc_kernel_version, 4831 PMC_VERSION); 4832 return EPROGMISMATCH; 4833 } 4834 4835 /* 4836 * check sysctl parameters 4837 */ 4838 4839 if (pmc_hashsize <= 0) { 4840 (void) printf("hwpmc: tunable \"hashsize\"=%d must be " 4841 "greater than zero.\n", pmc_hashsize); 4842 pmc_hashsize = PMC_HASH_SIZE; 4843 } 4844 4845 if (pmc_nsamples <= 0 || pmc_nsamples > 65535) { 4846 (void) printf("hwpmc: tunable \"nsamples\"=%d out of " 4847 "range.\n", pmc_nsamples); 4848 pmc_nsamples = PMC_NSAMPLES; 4849 } 4850 4851 if (pmc_callchaindepth <= 0 || 4852 pmc_callchaindepth > PMC_CALLCHAIN_DEPTH_MAX) { 4853 (void) printf("hwpmc: tunable \"callchaindepth\"=%d out of " 4854 "range - using %d.\n", pmc_callchaindepth, 4855 PMC_CALLCHAIN_DEPTH_MAX); 4856 pmc_callchaindepth = PMC_CALLCHAIN_DEPTH_MAX; 4857 } 4858 4859 md = pmc_md_initialize(); 4860 if (md == NULL) { 4861 /* Default to generic CPU. */ 4862 md = pmc_generic_cpu_initialize(); 4863 if (md == NULL) 4864 return (ENOSYS); 4865 } 4866 4867 KASSERT(md->pmd_nclass >= 1 && md->pmd_npmc >= 1, 4868 ("[pmc,%d] no classes or pmcs", __LINE__)); 4869 4870 /* Compute the map from row-indices to classdep pointers. */ 4871 pmc_rowindex_to_classdep = malloc(sizeof(struct pmc_classdep *) * 4872 md->pmd_npmc, M_PMC, M_WAITOK|M_ZERO); 4873 4874 for (n = 0; n < md->pmd_npmc; n++) 4875 pmc_rowindex_to_classdep[n] = NULL; 4876 for (ri = c = 0; c < md->pmd_nclass; c++) { 4877 pcd = &md->pmd_classdep[c]; 4878 for (n = 0; n < pcd->pcd_num; n++, ri++) 4879 pmc_rowindex_to_classdep[ri] = pcd; 4880 } 4881 4882 KASSERT(ri == md->pmd_npmc, 4883 ("[pmc,%d] npmc miscomputed: ri=%d, md->npmc=%d", __LINE__, 4884 ri, md->pmd_npmc)); 4885 4886 maxcpu = pmc_cpu_max(); 4887 4888 /* allocate space for the per-cpu array */ 4889 pmc_pcpu = malloc(maxcpu * sizeof(struct pmc_cpu *), M_PMC, 4890 M_WAITOK|M_ZERO); 4891 4892 /* per-cpu 'saved values' for managing process-mode PMCs */ 4893 pmc_pcpu_saved = malloc(sizeof(pmc_value_t) * maxcpu * md->pmd_npmc, 4894 M_PMC, M_WAITOK); 4895 4896 /* Perform CPU-dependent initialization. */ 4897 pmc_save_cpu_binding(&pb); 4898 error = 0; 4899 for (cpu = 0; error == 0 && cpu < maxcpu; cpu++) { 4900 if (!pmc_cpu_is_active(cpu)) 4901 continue; 4902 pmc_select_cpu(cpu); 4903 pmc_pcpu[cpu] = malloc(sizeof(struct pmc_cpu) + 4904 md->pmd_npmc * sizeof(struct pmc_hw *), M_PMC, 4905 M_WAITOK|M_ZERO); 4906 if (md->pmd_pcpu_init) 4907 error = md->pmd_pcpu_init(md, cpu); 4908 for (n = 0; error == 0 && n < md->pmd_nclass; n++) 4909 error = md->pmd_classdep[n].pcd_pcpu_init(md, cpu); 4910 } 4911 pmc_restore_cpu_binding(&pb); 4912 4913 if (error) 4914 return (error); 4915 4916 /* allocate space for the sample array */ 4917 for (cpu = 0; cpu < maxcpu; cpu++) { 4918 if (!pmc_cpu_is_active(cpu)) 4919 continue; 4920 4921 sb = malloc(sizeof(struct pmc_samplebuffer) + 4922 pmc_nsamples * sizeof(struct pmc_sample), M_PMC, 4923 M_WAITOK|M_ZERO); 4924 sb->ps_read = sb->ps_write = sb->ps_samples; 4925 sb->ps_fence = sb->ps_samples + pmc_nsamples; 4926 4927 KASSERT(pmc_pcpu[cpu] != NULL, 4928 ("[pmc,%d] cpu=%d Null per-cpu data", __LINE__, cpu)); 4929 4930 sb->ps_callchains = malloc(pmc_callchaindepth * pmc_nsamples * 4931 sizeof(uintptr_t), M_PMC, M_WAITOK|M_ZERO); 4932 4933 for (n = 0, ps = sb->ps_samples; n < pmc_nsamples; n++, ps++) 4934 ps->ps_pc = sb->ps_callchains + 4935 (n * pmc_callchaindepth); 4936 4937 pmc_pcpu[cpu]->pc_sb[PMC_HR] = sb; 4938 4939 sb = malloc(sizeof(struct pmc_samplebuffer) + 4940 pmc_nsamples * sizeof(struct pmc_sample), M_PMC, 4941 M_WAITOK|M_ZERO); 4942 sb->ps_read = sb->ps_write = sb->ps_samples; 4943 sb->ps_fence = sb->ps_samples + pmc_nsamples; 4944 4945 KASSERT(pmc_pcpu[cpu] != NULL, 4946 ("[pmc,%d] cpu=%d Null per-cpu data", __LINE__, cpu)); 4947 4948 sb->ps_callchains = malloc(pmc_callchaindepth * pmc_nsamples * 4949 sizeof(uintptr_t), M_PMC, M_WAITOK|M_ZERO); 4950 4951 for (n = 0, ps = sb->ps_samples; n < pmc_nsamples; n++, ps++) 4952 ps->ps_pc = sb->ps_callchains + 4953 (n * pmc_callchaindepth); 4954 4955 pmc_pcpu[cpu]->pc_sb[PMC_SR] = sb; 4956 } 4957 4958 /* allocate space for the row disposition array */ 4959 pmc_pmcdisp = malloc(sizeof(enum pmc_mode) * md->pmd_npmc, 4960 M_PMC, M_WAITOK|M_ZERO); 4961 4962 /* mark all PMCs as available */ 4963 for (n = 0; n < (int) md->pmd_npmc; n++) 4964 PMC_MARK_ROW_FREE(n); 4965 4966 /* allocate thread hash tables */ 4967 pmc_ownerhash = hashinit(pmc_hashsize, M_PMC, 4968 &pmc_ownerhashmask); 4969 4970 pmc_processhash = hashinit(pmc_hashsize, M_PMC, 4971 &pmc_processhashmask); 4972 mtx_init(&pmc_processhash_mtx, "pmc-process-hash", "pmc-leaf", 4973 MTX_SPIN); 4974 4975 LIST_INIT(&pmc_ss_owners); 4976 pmc_ss_count = 0; 4977 4978 /* allocate a pool of spin mutexes */ 4979 pmc_mtxpool = mtx_pool_create("pmc-leaf", pmc_mtxpool_size, 4980 MTX_SPIN); 4981 4982 PMCDBG4(MOD,INI,1, "pmc_ownerhash=%p, mask=0x%lx " 4983 "targethash=%p mask=0x%lx", pmc_ownerhash, pmc_ownerhashmask, 4984 pmc_processhash, pmc_processhashmask); 4985 4986 /* register process {exit,fork,exec} handlers */ 4987 pmc_exit_tag = EVENTHANDLER_REGISTER(process_exit, 4988 pmc_process_exit, NULL, EVENTHANDLER_PRI_ANY); 4989 pmc_fork_tag = EVENTHANDLER_REGISTER(process_fork, 4990 pmc_process_fork, NULL, EVENTHANDLER_PRI_ANY); 4991 4992 /* register kld event handlers */ 4993 pmc_kld_load_tag = EVENTHANDLER_REGISTER(kld_load, pmc_kld_load, 4994 NULL, EVENTHANDLER_PRI_ANY); 4995 pmc_kld_unload_tag = EVENTHANDLER_REGISTER(kld_unload, pmc_kld_unload, 4996 NULL, EVENTHANDLER_PRI_ANY); 4997 4998 /* initialize logging */ 4999 pmclog_initialize(); 5000 5001 /* set hook functions */ 5002 pmc_intr = md->pmd_intr; 5003 pmc_hook = pmc_hook_handler; 5004 5005 if (error == 0) { 5006 printf(PMC_MODULE_NAME ":"); 5007 for (n = 0; n < (int) md->pmd_nclass; n++) { 5008 pcd = &md->pmd_classdep[n]; 5009 printf(" %s/%d/%d/0x%b", 5010 pmc_name_of_pmcclass(pcd->pcd_class), 5011 pcd->pcd_num, 5012 pcd->pcd_width, 5013 pcd->pcd_caps, 5014 "\20" 5015 "\1INT\2USR\3SYS\4EDG\5THR" 5016 "\6REA\7WRI\10INV\11QUA\12PRC" 5017 "\13TAG\14CSC"); 5018 } 5019 printf("\n"); 5020 } 5021 5022 return (error); 5023 } 5024 5025 /* prepare to be unloaded */ 5026 static void 5027 pmc_cleanup(void) 5028 { 5029 int c, cpu; 5030 unsigned int maxcpu; 5031 struct pmc_ownerhash *ph; 5032 struct pmc_owner *po, *tmp; 5033 struct pmc_binding pb; 5034 #ifdef HWPMC_DEBUG 5035 struct pmc_processhash *prh; 5036 #endif 5037 5038 PMCDBG0(MOD,INI,0, "cleanup"); 5039 5040 /* switch off sampling */ 5041 CPU_ZERO(&pmc_cpumask); 5042 pmc_intr = NULL; 5043 5044 sx_xlock(&pmc_sx); 5045 if (pmc_hook == NULL) { /* being unloaded already */ 5046 sx_xunlock(&pmc_sx); 5047 return; 5048 } 5049 5050 pmc_hook = NULL; /* prevent new threads from entering module */ 5051 5052 /* deregister event handlers */ 5053 EVENTHANDLER_DEREGISTER(process_fork, pmc_fork_tag); 5054 EVENTHANDLER_DEREGISTER(process_exit, pmc_exit_tag); 5055 EVENTHANDLER_DEREGISTER(kld_load, pmc_kld_load_tag); 5056 EVENTHANDLER_DEREGISTER(kld_unload, pmc_kld_unload_tag); 5057 5058 /* send SIGBUS to all owner threads, free up allocations */ 5059 if (pmc_ownerhash) 5060 for (ph = pmc_ownerhash; 5061 ph <= &pmc_ownerhash[pmc_ownerhashmask]; 5062 ph++) { 5063 LIST_FOREACH_SAFE(po, ph, po_next, tmp) { 5064 pmc_remove_owner(po); 5065 5066 /* send SIGBUS to owner processes */ 5067 PMCDBG3(MOD,INI,2, "cleanup signal proc=%p " 5068 "(%d, %s)", po->po_owner, 5069 po->po_owner->p_pid, 5070 po->po_owner->p_comm); 5071 5072 PROC_LOCK(po->po_owner); 5073 kern_psignal(po->po_owner, SIGBUS); 5074 PROC_UNLOCK(po->po_owner); 5075 5076 pmc_destroy_owner_descriptor(po); 5077 } 5078 } 5079 5080 /* reclaim allocated data structures */ 5081 if (pmc_mtxpool) 5082 mtx_pool_destroy(&pmc_mtxpool); 5083 5084 mtx_destroy(&pmc_processhash_mtx); 5085 if (pmc_processhash) { 5086 #ifdef HWPMC_DEBUG 5087 struct pmc_process *pp; 5088 5089 PMCDBG0(MOD,INI,3, "destroy process hash"); 5090 for (prh = pmc_processhash; 5091 prh <= &pmc_processhash[pmc_processhashmask]; 5092 prh++) 5093 LIST_FOREACH(pp, prh, pp_next) 5094 PMCDBG1(MOD,INI,3, "pid=%d", pp->pp_proc->p_pid); 5095 #endif 5096 5097 hashdestroy(pmc_processhash, M_PMC, pmc_processhashmask); 5098 pmc_processhash = NULL; 5099 } 5100 5101 if (pmc_ownerhash) { 5102 PMCDBG0(MOD,INI,3, "destroy owner hash"); 5103 hashdestroy(pmc_ownerhash, M_PMC, pmc_ownerhashmask); 5104 pmc_ownerhash = NULL; 5105 } 5106 5107 KASSERT(LIST_EMPTY(&pmc_ss_owners), 5108 ("[pmc,%d] Global SS owner list not empty", __LINE__)); 5109 KASSERT(pmc_ss_count == 0, 5110 ("[pmc,%d] Global SS count not empty", __LINE__)); 5111 5112 /* do processor and pmc-class dependent cleanup */ 5113 maxcpu = pmc_cpu_max(); 5114 5115 PMCDBG0(MOD,INI,3, "md cleanup"); 5116 if (md) { 5117 pmc_save_cpu_binding(&pb); 5118 for (cpu = 0; cpu < maxcpu; cpu++) { 5119 PMCDBG2(MOD,INI,1,"pmc-cleanup cpu=%d pcs=%p", 5120 cpu, pmc_pcpu[cpu]); 5121 if (!pmc_cpu_is_active(cpu) || pmc_pcpu[cpu] == NULL) 5122 continue; 5123 pmc_select_cpu(cpu); 5124 for (c = 0; c < md->pmd_nclass; c++) 5125 md->pmd_classdep[c].pcd_pcpu_fini(md, cpu); 5126 if (md->pmd_pcpu_fini) 5127 md->pmd_pcpu_fini(md, cpu); 5128 } 5129 5130 if (md->pmd_cputype == PMC_CPU_GENERIC) 5131 pmc_generic_cpu_finalize(md); 5132 else 5133 pmc_md_finalize(md); 5134 5135 pmc_mdep_free(md); 5136 md = NULL; 5137 pmc_restore_cpu_binding(&pb); 5138 } 5139 5140 /* Free per-cpu descriptors. */ 5141 for (cpu = 0; cpu < maxcpu; cpu++) { 5142 if (!pmc_cpu_is_active(cpu)) 5143 continue; 5144 KASSERT(pmc_pcpu[cpu]->pc_sb[PMC_HR] != NULL, 5145 ("[pmc,%d] Null hw cpu sample buffer cpu=%d", __LINE__, 5146 cpu)); 5147 KASSERT(pmc_pcpu[cpu]->pc_sb[PMC_SR] != NULL, 5148 ("[pmc,%d] Null sw cpu sample buffer cpu=%d", __LINE__, 5149 cpu)); 5150 free(pmc_pcpu[cpu]->pc_sb[PMC_HR]->ps_callchains, M_PMC); 5151 free(pmc_pcpu[cpu]->pc_sb[PMC_HR], M_PMC); 5152 free(pmc_pcpu[cpu]->pc_sb[PMC_SR]->ps_callchains, M_PMC); 5153 free(pmc_pcpu[cpu]->pc_sb[PMC_SR], M_PMC); 5154 free(pmc_pcpu[cpu], M_PMC); 5155 } 5156 5157 free(pmc_pcpu, M_PMC); 5158 pmc_pcpu = NULL; 5159 5160 free(pmc_pcpu_saved, M_PMC); 5161 pmc_pcpu_saved = NULL; 5162 5163 if (pmc_pmcdisp) { 5164 free(pmc_pmcdisp, M_PMC); 5165 pmc_pmcdisp = NULL; 5166 } 5167 5168 if (pmc_rowindex_to_classdep) { 5169 free(pmc_rowindex_to_classdep, M_PMC); 5170 pmc_rowindex_to_classdep = NULL; 5171 } 5172 5173 pmclog_shutdown(); 5174 5175 sx_xunlock(&pmc_sx); /* we are done */ 5176 } 5177 5178 /* 5179 * The function called at load/unload. 5180 */ 5181 5182 static int 5183 load (struct module *module __unused, int cmd, void *arg __unused) 5184 { 5185 int error; 5186 5187 error = 0; 5188 5189 switch (cmd) { 5190 case MOD_LOAD : 5191 /* initialize the subsystem */ 5192 error = pmc_initialize(); 5193 if (error != 0) 5194 break; 5195 PMCDBG2(MOD,INI,1, "syscall=%d maxcpu=%d", 5196 pmc_syscall_num, pmc_cpu_max()); 5197 break; 5198 5199 5200 case MOD_UNLOAD : 5201 case MOD_SHUTDOWN: 5202 pmc_cleanup(); 5203 PMCDBG0(MOD,INI,1, "unloaded"); 5204 break; 5205 5206 default : 5207 error = EINVAL; /* XXX should panic(9) */ 5208 break; 5209 } 5210 5211 return error; 5212 } 5213 5214 /* memory pool */ 5215 MALLOC_DEFINE(M_PMC, "pmc", "Memory space for the PMC module"); 5216