hwpmc_mod.c revision 185363
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: head/sys/dev/hwpmc/hwpmc_mod.c 185363 2008-11-27 09:00:47Z jkoshy $"); 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/mutex.h> 45#include <sys/pmc.h> 46#include <sys/pmckern.h> 47#include <sys/pmclog.h> 48#include <sys/priv.h> 49#include <sys/proc.h> 50#include <sys/queue.h> 51#include <sys/resourcevar.h> 52#include <sys/sched.h> 53#include <sys/signalvar.h> 54#include <sys/smp.h> 55#include <sys/sx.h> 56#include <sys/sysctl.h> 57#include <sys/sysent.h> 58#include <sys/systm.h> 59#include <sys/vnode.h> 60 61#include <sys/linker.h> /* needs to be after <sys/malloc.h> */ 62 63#include <machine/atomic.h> 64#include <machine/md_var.h> 65 66/* 67 * Types 68 */ 69 70enum pmc_flags { 71 PMC_FLAG_NONE = 0x00, /* do nothing */ 72 PMC_FLAG_REMOVE = 0x01, /* atomically remove entry from hash */ 73 PMC_FLAG_ALLOCATE = 0x02, /* add entry to hash if not found */ 74}; 75 76/* 77 * The offset in sysent where the syscall is allocated. 78 */ 79 80static int pmc_syscall_num = NO_SYSCALL; 81struct pmc_cpu **pmc_pcpu; /* per-cpu state */ 82pmc_value_t *pmc_pcpu_saved; /* saved PMC values: CSW handling */ 83 84#define PMC_PCPU_SAVED(C,R) pmc_pcpu_saved[(R) + md->pmd_npmc*(C)] 85 86struct mtx_pool *pmc_mtxpool; 87static int *pmc_pmcdisp; /* PMC row dispositions */ 88 89#define PMC_ROW_DISP_IS_FREE(R) (pmc_pmcdisp[(R)] == 0) 90#define PMC_ROW_DISP_IS_THREAD(R) (pmc_pmcdisp[(R)] > 0) 91#define PMC_ROW_DISP_IS_STANDALONE(R) (pmc_pmcdisp[(R)] < 0) 92 93#define PMC_MARK_ROW_FREE(R) do { \ 94 pmc_pmcdisp[(R)] = 0; \ 95} while (0) 96 97#define PMC_MARK_ROW_STANDALONE(R) do { \ 98 KASSERT(pmc_pmcdisp[(R)] <= 0, ("[pmc,%d] row disposition error", \ 99 __LINE__)); \ 100 atomic_add_int(&pmc_pmcdisp[(R)], -1); \ 101 KASSERT(pmc_pmcdisp[(R)] >= (-pmc_cpu_max_active()), \ 102 ("[pmc,%d] row disposition error", __LINE__)); \ 103} while (0) 104 105#define PMC_UNMARK_ROW_STANDALONE(R) do { \ 106 atomic_add_int(&pmc_pmcdisp[(R)], 1); \ 107 KASSERT(pmc_pmcdisp[(R)] <= 0, ("[pmc,%d] row disposition error", \ 108 __LINE__)); \ 109} while (0) 110 111#define PMC_MARK_ROW_THREAD(R) do { \ 112 KASSERT(pmc_pmcdisp[(R)] >= 0, ("[pmc,%d] row disposition error", \ 113 __LINE__)); \ 114 atomic_add_int(&pmc_pmcdisp[(R)], 1); \ 115} while (0) 116 117#define PMC_UNMARK_ROW_THREAD(R) do { \ 118 atomic_add_int(&pmc_pmcdisp[(R)], -1); \ 119 KASSERT(pmc_pmcdisp[(R)] >= 0, ("[pmc,%d] row disposition error", \ 120 __LINE__)); \ 121} while (0) 122 123 124/* various event handlers */ 125static eventhandler_tag pmc_exit_tag, pmc_fork_tag; 126 127/* Module statistics */ 128struct pmc_op_getdriverstats pmc_stats; 129 130/* Machine/processor dependent operations */ 131static struct pmc_mdep *md; 132 133/* 134 * Hash tables mapping owner processes and target threads to PMCs. 135 */ 136 137struct mtx pmc_processhash_mtx; /* spin mutex */ 138static u_long pmc_processhashmask; 139static LIST_HEAD(pmc_processhash, pmc_process) *pmc_processhash; 140 141/* 142 * Hash table of PMC owner descriptors. This table is protected by 143 * the shared PMC "sx" lock. 144 */ 145 146static u_long pmc_ownerhashmask; 147static LIST_HEAD(pmc_ownerhash, pmc_owner) *pmc_ownerhash; 148 149/* 150 * List of PMC owners with system-wide sampling PMCs. 151 */ 152 153static LIST_HEAD(, pmc_owner) pmc_ss_owners; 154 155 156/* 157 * A map of row indices to classdep structures. 158 */ 159static struct pmc_classdep **pmc_rowindex_to_classdep; 160 161/* 162 * Prototypes 163 */ 164 165#ifdef DEBUG 166static int pmc_debugflags_sysctl_handler(SYSCTL_HANDLER_ARGS); 167static int pmc_debugflags_parse(char *newstr, char *fence); 168#endif 169 170static int load(struct module *module, int cmd, void *arg); 171static int pmc_attach_process(struct proc *p, struct pmc *pm); 172static struct pmc *pmc_allocate_pmc_descriptor(void); 173static struct pmc_owner *pmc_allocate_owner_descriptor(struct proc *p); 174static int pmc_attach_one_process(struct proc *p, struct pmc *pm); 175static int pmc_can_allocate_rowindex(struct proc *p, unsigned int ri, 176 int cpu); 177static int pmc_can_attach(struct pmc *pm, struct proc *p); 178static void pmc_capture_user_callchain(int cpu, struct trapframe *tf); 179static void pmc_cleanup(void); 180static int pmc_detach_process(struct proc *p, struct pmc *pm); 181static int pmc_detach_one_process(struct proc *p, struct pmc *pm, 182 int flags); 183static void pmc_destroy_owner_descriptor(struct pmc_owner *po); 184static struct pmc_owner *pmc_find_owner_descriptor(struct proc *p); 185static int pmc_find_pmc(pmc_id_t pmcid, struct pmc **pm); 186static struct pmc *pmc_find_pmc_descriptor_in_process(struct pmc_owner *po, 187 pmc_id_t pmc); 188static struct pmc_process *pmc_find_process_descriptor(struct proc *p, 189 uint32_t mode); 190static void pmc_force_context_switch(void); 191static void pmc_link_target_process(struct pmc *pm, 192 struct pmc_process *pp); 193static void pmc_log_all_process_mappings(struct pmc_owner *po); 194static void pmc_log_kernel_mappings(struct pmc *pm); 195static void pmc_log_process_mappings(struct pmc_owner *po, struct proc *p); 196static void pmc_maybe_remove_owner(struct pmc_owner *po); 197static void pmc_process_csw_in(struct thread *td); 198static void pmc_process_csw_out(struct thread *td); 199static void pmc_process_exit(void *arg, struct proc *p); 200static void pmc_process_fork(void *arg, struct proc *p1, 201 struct proc *p2, int n); 202static void pmc_process_samples(int cpu); 203static void pmc_release_pmc_descriptor(struct pmc *pmc); 204static void pmc_remove_owner(struct pmc_owner *po); 205static void pmc_remove_process_descriptor(struct pmc_process *pp); 206static void pmc_restore_cpu_binding(struct pmc_binding *pb); 207static void pmc_save_cpu_binding(struct pmc_binding *pb); 208static void pmc_select_cpu(int cpu); 209static int pmc_start(struct pmc *pm); 210static int pmc_stop(struct pmc *pm); 211static int pmc_syscall_handler(struct thread *td, void *syscall_args); 212static void pmc_unlink_target_process(struct pmc *pmc, 213 struct pmc_process *pp); 214 215/* 216 * Kernel tunables and sysctl(8) interface. 217 */ 218 219SYSCTL_NODE(_kern, OID_AUTO, hwpmc, CTLFLAG_RW, 0, "HWPMC parameters"); 220 221static int pmc_callchaindepth = PMC_CALLCHAIN_DEPTH; 222TUNABLE_INT(PMC_SYSCTL_NAME_PREFIX "callchaindepth", &pmc_callchaindepth); 223SYSCTL_INT(_kern_hwpmc, OID_AUTO, callchaindepth, CTLFLAG_TUN|CTLFLAG_RD, 224 &pmc_callchaindepth, 0, "depth of call chain records"); 225 226#ifdef DEBUG 227struct pmc_debugflags pmc_debugflags = PMC_DEBUG_DEFAULT_FLAGS; 228char pmc_debugstr[PMC_DEBUG_STRSIZE]; 229TUNABLE_STR(PMC_SYSCTL_NAME_PREFIX "debugflags", pmc_debugstr, 230 sizeof(pmc_debugstr)); 231SYSCTL_PROC(_kern_hwpmc, OID_AUTO, debugflags, 232 CTLTYPE_STRING|CTLFLAG_RW|CTLFLAG_TUN, 233 0, 0, pmc_debugflags_sysctl_handler, "A", "debug flags"); 234#endif 235 236/* 237 * kern.hwpmc.hashrows -- determines the number of rows in the 238 * of the hash table used to look up threads 239 */ 240 241static int pmc_hashsize = PMC_HASH_SIZE; 242TUNABLE_INT(PMC_SYSCTL_NAME_PREFIX "hashsize", &pmc_hashsize); 243SYSCTL_INT(_kern_hwpmc, OID_AUTO, hashsize, CTLFLAG_TUN|CTLFLAG_RD, 244 &pmc_hashsize, 0, "rows in hash tables"); 245 246/* 247 * kern.hwpmc.nsamples --- number of PC samples/callchain stacks per CPU 248 */ 249 250static int pmc_nsamples = PMC_NSAMPLES; 251TUNABLE_INT(PMC_SYSCTL_NAME_PREFIX "nsamples", &pmc_nsamples); 252SYSCTL_INT(_kern_hwpmc, OID_AUTO, nsamples, CTLFLAG_TUN|CTLFLAG_RD, 253 &pmc_nsamples, 0, "number of PC samples per CPU"); 254 255 256/* 257 * kern.hwpmc.mtxpoolsize -- number of mutexes in the mutex pool. 258 */ 259 260static int pmc_mtxpool_size = PMC_MTXPOOL_SIZE; 261TUNABLE_INT(PMC_SYSCTL_NAME_PREFIX "mtxpoolsize", &pmc_mtxpool_size); 262SYSCTL_INT(_kern_hwpmc, OID_AUTO, mtxpoolsize, CTLFLAG_TUN|CTLFLAG_RD, 263 &pmc_mtxpool_size, 0, "size of spin mutex pool"); 264 265 266/* 267 * security.bsd.unprivileged_syspmcs -- allow non-root processes to 268 * allocate system-wide PMCs. 269 * 270 * Allowing unprivileged processes to allocate system PMCs is convenient 271 * if system-wide measurements need to be taken concurrently with other 272 * per-process measurements. This feature is turned off by default. 273 */ 274 275static int pmc_unprivileged_syspmcs = 0; 276TUNABLE_INT("security.bsd.unprivileged_syspmcs", &pmc_unprivileged_syspmcs); 277SYSCTL_INT(_security_bsd, OID_AUTO, unprivileged_syspmcs, CTLFLAG_RW, 278 &pmc_unprivileged_syspmcs, 0, 279 "allow unprivileged process to allocate system PMCs"); 280 281/* 282 * Hash function. Discard the lower 2 bits of the pointer since 283 * these are always zero for our uses. The hash multiplier is 284 * round((2^LONG_BIT) * ((sqrt(5)-1)/2)). 285 */ 286 287#if LONG_BIT == 64 288#define _PMC_HM 11400714819323198486u 289#elif LONG_BIT == 32 290#define _PMC_HM 2654435769u 291#else 292#error Must know the size of 'long' to compile 293#endif 294 295#define PMC_HASH_PTR(P,M) ((((unsigned long) (P) >> 2) * _PMC_HM) & (M)) 296 297/* 298 * Syscall structures 299 */ 300 301/* The `sysent' for the new syscall */ 302static struct sysent pmc_sysent = { 303 2, /* sy_narg */ 304 pmc_syscall_handler /* sy_call */ 305}; 306 307static struct syscall_module_data pmc_syscall_mod = { 308 load, 309 NULL, 310 &pmc_syscall_num, 311 &pmc_sysent, 312 { 0, NULL } 313}; 314 315static moduledata_t pmc_mod = { 316 PMC_MODULE_NAME, 317 syscall_module_handler, 318 &pmc_syscall_mod 319}; 320 321DECLARE_MODULE(pmc, pmc_mod, SI_SUB_SMP, SI_ORDER_ANY); 322MODULE_VERSION(pmc, PMC_VERSION); 323 324#ifdef DEBUG 325enum pmc_dbgparse_state { 326 PMCDS_WS, /* in whitespace */ 327 PMCDS_MAJOR, /* seen a major keyword */ 328 PMCDS_MINOR 329}; 330 331static int 332pmc_debugflags_parse(char *newstr, char *fence) 333{ 334 char c, *p, *q; 335 struct pmc_debugflags *tmpflags; 336 int error, found, *newbits, tmp; 337 size_t kwlen; 338 339 tmpflags = malloc(sizeof(*tmpflags), M_PMC, M_WAITOK|M_ZERO); 340 341 p = newstr; 342 error = 0; 343 344 for (; p < fence && (c = *p); p++) { 345 346 /* skip white space */ 347 if (c == ' ' || c == '\t') 348 continue; 349 350 /* look for a keyword followed by "=" */ 351 for (q = p; p < fence && (c = *p) && c != '='; p++) 352 ; 353 if (c != '=') { 354 error = EINVAL; 355 goto done; 356 } 357 358 kwlen = p - q; 359 newbits = NULL; 360 361 /* lookup flag group name */ 362#define DBG_SET_FLAG_MAJ(S,F) \ 363 if (kwlen == sizeof(S)-1 && strncmp(q, S, kwlen) == 0) \ 364 newbits = &tmpflags->pdb_ ## F; 365 366 DBG_SET_FLAG_MAJ("cpu", CPU); 367 DBG_SET_FLAG_MAJ("csw", CSW); 368 DBG_SET_FLAG_MAJ("logging", LOG); 369 DBG_SET_FLAG_MAJ("module", MOD); 370 DBG_SET_FLAG_MAJ("md", MDP); 371 DBG_SET_FLAG_MAJ("owner", OWN); 372 DBG_SET_FLAG_MAJ("pmc", PMC); 373 DBG_SET_FLAG_MAJ("process", PRC); 374 DBG_SET_FLAG_MAJ("sampling", SAM); 375 376 if (newbits == NULL) { 377 error = EINVAL; 378 goto done; 379 } 380 381 p++; /* skip the '=' */ 382 383 /* Now parse the individual flags */ 384 tmp = 0; 385 newflag: 386 for (q = p; p < fence && (c = *p); p++) 387 if (c == ' ' || c == '\t' || c == ',') 388 break; 389 390 /* p == fence or c == ws or c == "," or c == 0 */ 391 392 if ((kwlen = p - q) == 0) { 393 *newbits = tmp; 394 continue; 395 } 396 397 found = 0; 398#define DBG_SET_FLAG_MIN(S,F) \ 399 if (kwlen == sizeof(S)-1 && strncmp(q, S, kwlen) == 0) \ 400 tmp |= found = (1 << PMC_DEBUG_MIN_ ## F) 401 402 /* a '*' denotes all possible flags in the group */ 403 if (kwlen == 1 && *q == '*') 404 tmp = found = ~0; 405 /* look for individual flag names */ 406 DBG_SET_FLAG_MIN("allocaterow", ALR); 407 DBG_SET_FLAG_MIN("allocate", ALL); 408 DBG_SET_FLAG_MIN("attach", ATT); 409 DBG_SET_FLAG_MIN("bind", BND); 410 DBG_SET_FLAG_MIN("config", CFG); 411 DBG_SET_FLAG_MIN("exec", EXC); 412 DBG_SET_FLAG_MIN("exit", EXT); 413 DBG_SET_FLAG_MIN("find", FND); 414 DBG_SET_FLAG_MIN("flush", FLS); 415 DBG_SET_FLAG_MIN("fork", FRK); 416 DBG_SET_FLAG_MIN("getbuf", GTB); 417 DBG_SET_FLAG_MIN("hook", PMH); 418 DBG_SET_FLAG_MIN("init", INI); 419 DBG_SET_FLAG_MIN("intr", INT); 420 DBG_SET_FLAG_MIN("linktarget", TLK); 421 DBG_SET_FLAG_MIN("mayberemove", OMR); 422 DBG_SET_FLAG_MIN("ops", OPS); 423 DBG_SET_FLAG_MIN("read", REA); 424 DBG_SET_FLAG_MIN("register", REG); 425 DBG_SET_FLAG_MIN("release", REL); 426 DBG_SET_FLAG_MIN("remove", ORM); 427 DBG_SET_FLAG_MIN("sample", SAM); 428 DBG_SET_FLAG_MIN("scheduleio", SIO); 429 DBG_SET_FLAG_MIN("select", SEL); 430 DBG_SET_FLAG_MIN("signal", SIG); 431 DBG_SET_FLAG_MIN("swi", SWI); 432 DBG_SET_FLAG_MIN("swo", SWO); 433 DBG_SET_FLAG_MIN("start", STA); 434 DBG_SET_FLAG_MIN("stop", STO); 435 DBG_SET_FLAG_MIN("syscall", PMS); 436 DBG_SET_FLAG_MIN("unlinktarget", TUL); 437 DBG_SET_FLAG_MIN("write", WRI); 438 if (found == 0) { 439 /* unrecognized flag name */ 440 error = EINVAL; 441 goto done; 442 } 443 444 if (c == 0 || c == ' ' || c == '\t') { /* end of flag group */ 445 *newbits = tmp; 446 continue; 447 } 448 449 p++; 450 goto newflag; 451 } 452 453 /* save the new flag set */ 454 bcopy(tmpflags, &pmc_debugflags, sizeof(pmc_debugflags)); 455 456 done: 457 free(tmpflags, M_PMC); 458 return error; 459} 460 461static int 462pmc_debugflags_sysctl_handler(SYSCTL_HANDLER_ARGS) 463{ 464 char *fence, *newstr; 465 int error; 466 unsigned int n; 467 468 (void) arg1; (void) arg2; /* unused parameters */ 469 470 n = sizeof(pmc_debugstr); 471 newstr = malloc(n, M_PMC, M_WAITOK|M_ZERO); 472 (void) strlcpy(newstr, pmc_debugstr, n); 473 474 error = sysctl_handle_string(oidp, newstr, n, req); 475 476 /* if there is a new string, parse and copy it */ 477 if (error == 0 && req->newptr != NULL) { 478 fence = newstr + (n < req->newlen ? n : req->newlen + 1); 479 if ((error = pmc_debugflags_parse(newstr, fence)) == 0) 480 (void) strlcpy(pmc_debugstr, newstr, 481 sizeof(pmc_debugstr)); 482 } 483 484 free(newstr, M_PMC); 485 486 return error; 487} 488#endif 489 490/* 491 * Map a row index to a classdep structure and return the adjusted row 492 * index for the PMC class index. 493 */ 494static struct pmc_classdep * 495pmc_ri_to_classdep(struct pmc_mdep *md, int ri, int *adjri) 496{ 497 struct pmc_classdep *pcd; 498 499 (void) md; 500 501 KASSERT(ri >= 0 && ri < md->pmd_npmc, 502 ("[pmc,%d] illegal row-index %d", __LINE__, ri)); 503 504 pcd = pmc_rowindex_to_classdep[ri]; 505 506 KASSERT(pcd != NULL, 507 ("[amd,%d] ri %d null pcd", __LINE__, ri)); 508 509 *adjri = ri - pcd->pcd_ri; 510 511 KASSERT(*adjri >= 0 && *adjri < pcd->pcd_num, 512 ("[pmc,%d] adjusted row-index %d", __LINE__, *adjri)); 513 514 return (pcd); 515} 516 517/* 518 * Concurrency Control 519 * 520 * The driver manages the following data structures: 521 * 522 * - target process descriptors, one per target process 523 * - owner process descriptors (and attached lists), one per owner process 524 * - lookup hash tables for owner and target processes 525 * - PMC descriptors (and attached lists) 526 * - per-cpu hardware state 527 * - the 'hook' variable through which the kernel calls into 528 * this module 529 * - the machine hardware state (managed by the MD layer) 530 * 531 * These data structures are accessed from: 532 * 533 * - thread context-switch code 534 * - interrupt handlers (possibly on multiple cpus) 535 * - kernel threads on multiple cpus running on behalf of user 536 * processes doing system calls 537 * - this driver's private kernel threads 538 * 539 * = Locks and Locking strategy = 540 * 541 * The driver uses four locking strategies for its operation: 542 * 543 * - The global SX lock "pmc_sx" is used to protect internal 544 * data structures. 545 * 546 * Calls into the module by syscall() start with this lock being 547 * held in exclusive mode. Depending on the requested operation, 548 * the lock may be downgraded to 'shared' mode to allow more 549 * concurrent readers into the module. Calls into the module from 550 * other parts of the kernel acquire the lock in shared mode. 551 * 552 * This SX lock is held in exclusive mode for any operations that 553 * modify the linkages between the driver's internal data structures. 554 * 555 * The 'pmc_hook' function pointer is also protected by this lock. 556 * It is only examined with the sx lock held in exclusive mode. The 557 * kernel module is allowed to be unloaded only with the sx lock held 558 * in exclusive mode. In normal syscall handling, after acquiring the 559 * pmc_sx lock we first check that 'pmc_hook' is non-null before 560 * proceeding. This prevents races between the thread unloading the module 561 * and other threads seeking to use the module. 562 * 563 * - Lookups of target process structures and owner process structures 564 * cannot use the global "pmc_sx" SX lock because these lookups need 565 * to happen during context switches and in other critical sections 566 * where sleeping is not allowed. We protect these lookup tables 567 * with their own private spin-mutexes, "pmc_processhash_mtx" and 568 * "pmc_ownerhash_mtx". 569 * 570 * - Interrupt handlers work in a lock free manner. At interrupt 571 * time, handlers look at the PMC pointer (phw->phw_pmc) configured 572 * when the PMC was started. If this pointer is NULL, the interrupt 573 * is ignored after updating driver statistics. We ensure that this 574 * pointer is set (using an atomic operation if necessary) before the 575 * PMC hardware is started. Conversely, this pointer is unset atomically 576 * only after the PMC hardware is stopped. 577 * 578 * We ensure that everything needed for the operation of an 579 * interrupt handler is available without it needing to acquire any 580 * locks. We also ensure that a PMC's software state is destroyed only 581 * after the PMC is taken off hardware (on all CPUs). 582 * 583 * - Context-switch handling with process-private PMCs needs more 584 * care. 585 * 586 * A given process may be the target of multiple PMCs. For example, 587 * PMCATTACH and PMCDETACH may be requested by a process on one CPU 588 * while the target process is running on another. A PMC could also 589 * be getting released because its owner is exiting. We tackle 590 * these situations in the following manner: 591 * 592 * - each target process structure 'pmc_process' has an array 593 * of 'struct pmc *' pointers, one for each hardware PMC. 594 * 595 * - At context switch IN time, each "target" PMC in RUNNING state 596 * gets started on hardware and a pointer to each PMC is copied into 597 * the per-cpu phw array. The 'runcount' for the PMC is 598 * incremented. 599 * 600 * - At context switch OUT time, all process-virtual PMCs are stopped 601 * on hardware. The saved value is added to the PMCs value field 602 * only if the PMC is in a non-deleted state (the PMCs state could 603 * have changed during the current time slice). 604 * 605 * Note that since in-between a switch IN on a processor and a switch 606 * OUT, the PMC could have been released on another CPU. Therefore 607 * context switch OUT always looks at the hardware state to turn 608 * OFF PMCs and will update a PMC's saved value only if reachable 609 * from the target process record. 610 * 611 * - OP PMCRELEASE could be called on a PMC at any time (the PMC could 612 * be attached to many processes at the time of the call and could 613 * be active on multiple CPUs). 614 * 615 * We prevent further scheduling of the PMC by marking it as in 616 * state 'DELETED'. If the runcount of the PMC is non-zero then 617 * this PMC is currently running on a CPU somewhere. The thread 618 * doing the PMCRELEASE operation waits by repeatedly doing a 619 * pause() till the runcount comes to zero. 620 * 621 * The contents of a PMC descriptor (struct pmc) are protected using 622 * a spin-mutex. In order to save space, we use a mutex pool. 623 * 624 * In terms of lock types used by witness(4), we use: 625 * - Type "pmc-sx", used by the global SX lock. 626 * - Type "pmc-sleep", for sleep mutexes used by logger threads. 627 * - Type "pmc-per-proc", for protecting PMC owner descriptors. 628 * - Type "pmc-leaf", used for all other spin mutexes. 629 */ 630 631/* 632 * save the cpu binding of the current kthread 633 */ 634 635static void 636pmc_save_cpu_binding(struct pmc_binding *pb) 637{ 638 PMCDBG(CPU,BND,2, "%s", "save-cpu"); 639 thread_lock(curthread); 640 pb->pb_bound = sched_is_bound(curthread); 641 pb->pb_cpu = curthread->td_oncpu; 642 thread_unlock(curthread); 643 PMCDBG(CPU,BND,2, "save-cpu cpu=%d", pb->pb_cpu); 644} 645 646/* 647 * restore the cpu binding of the current thread 648 */ 649 650static void 651pmc_restore_cpu_binding(struct pmc_binding *pb) 652{ 653 PMCDBG(CPU,BND,2, "restore-cpu curcpu=%d restore=%d", 654 curthread->td_oncpu, pb->pb_cpu); 655 thread_lock(curthread); 656 if (pb->pb_bound) 657 sched_bind(curthread, pb->pb_cpu); 658 else 659 sched_unbind(curthread); 660 thread_unlock(curthread); 661 PMCDBG(CPU,BND,2, "%s", "restore-cpu done"); 662} 663 664/* 665 * move execution over the specified cpu and bind it there. 666 */ 667 668static void 669pmc_select_cpu(int cpu) 670{ 671 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 672 ("[pmc,%d] bad cpu number %d", __LINE__, cpu)); 673 674 /* Never move to an inactive CPU. */ 675 KASSERT(pmc_cpu_is_active(cpu), ("[pmc,%d] selecting inactive " 676 "CPU %d", __LINE__, cpu)); 677 678 PMCDBG(CPU,SEL,2, "select-cpu cpu=%d", cpu); 679 thread_lock(curthread); 680 sched_bind(curthread, cpu); 681 thread_unlock(curthread); 682 683 KASSERT(curthread->td_oncpu == cpu, 684 ("[pmc,%d] CPU not bound [cpu=%d, curr=%d]", __LINE__, 685 cpu, curthread->td_oncpu)); 686 687 PMCDBG(CPU,SEL,2, "select-cpu cpu=%d ok", cpu); 688} 689 690/* 691 * Force a context switch. 692 * 693 * We do this by pause'ing for 1 tick -- invoking mi_switch() is not 694 * guaranteed to force a context switch. 695 */ 696 697static void 698pmc_force_context_switch(void) 699{ 700 701 pause("pmcctx", 1); 702} 703 704/* 705 * Get the file name for an executable. This is a simple wrapper 706 * around vn_fullpath(9). 707 */ 708 709static void 710pmc_getfilename(struct vnode *v, char **fullpath, char **freepath) 711{ 712 713 *fullpath = "unknown"; 714 *freepath = NULL; 715 vn_fullpath(curthread, v, fullpath, freepath); 716} 717 718/* 719 * remove an process owning PMCs 720 */ 721 722void 723pmc_remove_owner(struct pmc_owner *po) 724{ 725 struct pmc *pm, *tmp; 726 727 sx_assert(&pmc_sx, SX_XLOCKED); 728 729 PMCDBG(OWN,ORM,1, "remove-owner po=%p", po); 730 731 /* Remove descriptor from the owner hash table */ 732 LIST_REMOVE(po, po_next); 733 734 /* release all owned PMC descriptors */ 735 LIST_FOREACH_SAFE(pm, &po->po_pmcs, pm_next, tmp) { 736 PMCDBG(OWN,ORM,2, "pmc=%p", pm); 737 KASSERT(pm->pm_owner == po, 738 ("[pmc,%d] owner %p != po %p", __LINE__, pm->pm_owner, po)); 739 740 pmc_release_pmc_descriptor(pm); /* will unlink from the list */ 741 } 742 743 KASSERT(po->po_sscount == 0, 744 ("[pmc,%d] SS count not zero", __LINE__)); 745 KASSERT(LIST_EMPTY(&po->po_pmcs), 746 ("[pmc,%d] PMC list not empty", __LINE__)); 747 748 /* de-configure the log file if present */ 749 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 750 pmclog_deconfigure_log(po); 751} 752 753/* 754 * remove an owner process record if all conditions are met. 755 */ 756 757static void 758pmc_maybe_remove_owner(struct pmc_owner *po) 759{ 760 761 PMCDBG(OWN,OMR,1, "maybe-remove-owner po=%p", po); 762 763 /* 764 * Remove owner record if 765 * - this process does not own any PMCs 766 * - this process has not allocated a system-wide sampling buffer 767 */ 768 769 if (LIST_EMPTY(&po->po_pmcs) && 770 ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0)) { 771 pmc_remove_owner(po); 772 pmc_destroy_owner_descriptor(po); 773 } 774} 775 776/* 777 * Add an association between a target process and a PMC. 778 */ 779 780static void 781pmc_link_target_process(struct pmc *pm, struct pmc_process *pp) 782{ 783 int ri; 784 struct pmc_target *pt; 785 786 sx_assert(&pmc_sx, SX_XLOCKED); 787 788 KASSERT(pm != NULL && pp != NULL, 789 ("[pmc,%d] Null pm %p or pp %p", __LINE__, pm, pp)); 790 KASSERT(PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)), 791 ("[pmc,%d] Attaching a non-process-virtual pmc=%p to pid=%d", 792 __LINE__, pm, pp->pp_proc->p_pid)); 793 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt < ((int) md->pmd_npmc - 1), 794 ("[pmc,%d] Illegal reference count %d for process record %p", 795 __LINE__, pp->pp_refcnt, (void *) pp)); 796 797 ri = PMC_TO_ROWINDEX(pm); 798 799 PMCDBG(PRC,TLK,1, "link-target pmc=%p ri=%d pmc-process=%p", 800 pm, ri, pp); 801 802#ifdef DEBUG 803 LIST_FOREACH(pt, &pm->pm_targets, pt_next) 804 if (pt->pt_process == pp) 805 KASSERT(0, ("[pmc,%d] pp %p already in pmc %p targets", 806 __LINE__, pp, pm)); 807#endif 808 809 pt = malloc(sizeof(struct pmc_target), M_PMC, M_WAITOK|M_ZERO); 810 pt->pt_process = pp; 811 812 LIST_INSERT_HEAD(&pm->pm_targets, pt, pt_next); 813 814 atomic_store_rel_ptr((uintptr_t *)&pp->pp_pmcs[ri].pp_pmc, 815 (uintptr_t)pm); 816 817 if (pm->pm_owner->po_owner == pp->pp_proc) 818 pm->pm_flags |= PMC_F_ATTACHED_TO_OWNER; 819 820 /* 821 * Initialize the per-process values at this row index. 822 */ 823 pp->pp_pmcs[ri].pp_pmcval = PMC_TO_MODE(pm) == PMC_MODE_TS ? 824 pm->pm_sc.pm_reloadcount : 0; 825 826 pp->pp_refcnt++; 827 828} 829 830/* 831 * Removes the association between a target process and a PMC. 832 */ 833 834static void 835pmc_unlink_target_process(struct pmc *pm, struct pmc_process *pp) 836{ 837 int ri; 838 struct proc *p; 839 struct pmc_target *ptgt; 840 841 sx_assert(&pmc_sx, SX_XLOCKED); 842 843 KASSERT(pm != NULL && pp != NULL, 844 ("[pmc,%d] Null pm %p or pp %p", __LINE__, pm, pp)); 845 846 KASSERT(pp->pp_refcnt >= 1 && pp->pp_refcnt < (int) md->pmd_npmc, 847 ("[pmc,%d] Illegal ref count %d on process record %p", 848 __LINE__, pp->pp_refcnt, (void *) pp)); 849 850 ri = PMC_TO_ROWINDEX(pm); 851 852 PMCDBG(PRC,TUL,1, "unlink-target pmc=%p ri=%d pmc-process=%p", 853 pm, ri, pp); 854 855 KASSERT(pp->pp_pmcs[ri].pp_pmc == pm, 856 ("[pmc,%d] PMC ri %d mismatch pmc %p pp->[ri] %p", __LINE__, 857 ri, pm, pp->pp_pmcs[ri].pp_pmc)); 858 859 pp->pp_pmcs[ri].pp_pmc = NULL; 860 pp->pp_pmcs[ri].pp_pmcval = (pmc_value_t) 0; 861 862 /* Remove owner-specific flags */ 863 if (pm->pm_owner->po_owner == pp->pp_proc) { 864 pp->pp_flags &= ~PMC_PP_ENABLE_MSR_ACCESS; 865 pm->pm_flags &= ~PMC_F_ATTACHED_TO_OWNER; 866 } 867 868 pp->pp_refcnt--; 869 870 /* Remove the target process from the PMC structure */ 871 LIST_FOREACH(ptgt, &pm->pm_targets, pt_next) 872 if (ptgt->pt_process == pp) 873 break; 874 875 KASSERT(ptgt != NULL, ("[pmc,%d] process %p (pp: %p) not found " 876 "in pmc %p", __LINE__, pp->pp_proc, pp, pm)); 877 878 LIST_REMOVE(ptgt, pt_next); 879 free(ptgt, M_PMC); 880 881 /* if the PMC now lacks targets, send the owner a SIGIO */ 882 if (LIST_EMPTY(&pm->pm_targets)) { 883 p = pm->pm_owner->po_owner; 884 PROC_LOCK(p); 885 psignal(p, SIGIO); 886 PROC_UNLOCK(p); 887 888 PMCDBG(PRC,SIG,2, "signalling proc=%p signal=%d", p, 889 SIGIO); 890 } 891} 892 893/* 894 * Check if PMC 'pm' may be attached to target process 't'. 895 */ 896 897static int 898pmc_can_attach(struct pmc *pm, struct proc *t) 899{ 900 struct proc *o; /* pmc owner */ 901 struct ucred *oc, *tc; /* owner, target credentials */ 902 int decline_attach, i; 903 904 /* 905 * A PMC's owner can always attach that PMC to itself. 906 */ 907 908 if ((o = pm->pm_owner->po_owner) == t) 909 return 0; 910 911 PROC_LOCK(o); 912 oc = o->p_ucred; 913 crhold(oc); 914 PROC_UNLOCK(o); 915 916 PROC_LOCK(t); 917 tc = t->p_ucred; 918 crhold(tc); 919 PROC_UNLOCK(t); 920 921 /* 922 * The effective uid of the PMC owner should match at least one 923 * of the {effective,real,saved} uids of the target process. 924 */ 925 926 decline_attach = oc->cr_uid != tc->cr_uid && 927 oc->cr_uid != tc->cr_svuid && 928 oc->cr_uid != tc->cr_ruid; 929 930 /* 931 * Every one of the target's group ids, must be in the owner's 932 * group list. 933 */ 934 for (i = 0; !decline_attach && i < tc->cr_ngroups; i++) 935 decline_attach = !groupmember(tc->cr_groups[i], oc); 936 937 /* check the read and saved gids too */ 938 if (decline_attach == 0) 939 decline_attach = !groupmember(tc->cr_rgid, oc) || 940 !groupmember(tc->cr_svgid, oc); 941 942 crfree(tc); 943 crfree(oc); 944 945 return !decline_attach; 946} 947 948/* 949 * Attach a process to a PMC. 950 */ 951 952static int 953pmc_attach_one_process(struct proc *p, struct pmc *pm) 954{ 955 int ri; 956 char *fullpath, *freepath; 957 struct pmc_process *pp; 958 959 sx_assert(&pmc_sx, SX_XLOCKED); 960 961 PMCDBG(PRC,ATT,2, "attach-one pm=%p ri=%d proc=%p (%d, %s)", pm, 962 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 963 964 /* 965 * Locate the process descriptor corresponding to process 'p', 966 * allocating space as needed. 967 * 968 * Verify that rowindex 'pm_rowindex' is free in the process 969 * descriptor. 970 * 971 * If not, allocate space for a descriptor and link the 972 * process descriptor and PMC. 973 */ 974 ri = PMC_TO_ROWINDEX(pm); 975 976 if ((pp = pmc_find_process_descriptor(p, PMC_FLAG_ALLOCATE)) == NULL) 977 return ENOMEM; 978 979 if (pp->pp_pmcs[ri].pp_pmc == pm) /* already present at slot [ri] */ 980 return EEXIST; 981 982 if (pp->pp_pmcs[ri].pp_pmc != NULL) 983 return EBUSY; 984 985 pmc_link_target_process(pm, pp); 986 987 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)) && 988 (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) == 0) 989 pm->pm_flags |= PMC_F_NEEDS_LOGFILE; 990 991 pm->pm_flags |= PMC_F_ATTACH_DONE; /* mark as attached */ 992 993 /* issue an attach event to a configured log file */ 994 if (pm->pm_owner->po_flags & PMC_PO_OWNS_LOGFILE) { 995 pmc_getfilename(p->p_textvp, &fullpath, &freepath); 996 if (p->p_flag & P_KTHREAD) { 997 fullpath = kernelname; 998 freepath = NULL; 999 } else 1000 pmclog_process_pmcattach(pm, p->p_pid, fullpath); 1001 if (freepath) 1002 free(freepath, M_TEMP); 1003 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 1004 pmc_log_process_mappings(pm->pm_owner, p); 1005 } 1006 /* mark process as using HWPMCs */ 1007 PROC_LOCK(p); 1008 p->p_flag |= P_HWPMC; 1009 PROC_UNLOCK(p); 1010 1011 return 0; 1012} 1013 1014/* 1015 * Attach a process and optionally its children 1016 */ 1017 1018static int 1019pmc_attach_process(struct proc *p, struct pmc *pm) 1020{ 1021 int error; 1022 struct proc *top; 1023 1024 sx_assert(&pmc_sx, SX_XLOCKED); 1025 1026 PMCDBG(PRC,ATT,1, "attach pm=%p ri=%d proc=%p (%d, %s)", pm, 1027 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 1028 1029 1030 /* 1031 * If this PMC successfully allowed a GETMSR operation 1032 * in the past, disallow further ATTACHes. 1033 */ 1034 1035 if ((pm->pm_flags & PMC_PP_ENABLE_MSR_ACCESS) != 0) 1036 return EPERM; 1037 1038 if ((pm->pm_flags & PMC_F_DESCENDANTS) == 0) 1039 return pmc_attach_one_process(p, pm); 1040 1041 /* 1042 * Traverse all child processes, attaching them to 1043 * this PMC. 1044 */ 1045 1046 sx_slock(&proctree_lock); 1047 1048 top = p; 1049 1050 for (;;) { 1051 if ((error = pmc_attach_one_process(p, pm)) != 0) 1052 break; 1053 if (!LIST_EMPTY(&p->p_children)) 1054 p = LIST_FIRST(&p->p_children); 1055 else for (;;) { 1056 if (p == top) 1057 goto done; 1058 if (LIST_NEXT(p, p_sibling)) { 1059 p = LIST_NEXT(p, p_sibling); 1060 break; 1061 } 1062 p = p->p_pptr; 1063 } 1064 } 1065 1066 if (error) 1067 (void) pmc_detach_process(top, pm); 1068 1069 done: 1070 sx_sunlock(&proctree_lock); 1071 return error; 1072} 1073 1074/* 1075 * Detach a process from a PMC. If there are no other PMCs tracking 1076 * this process, remove the process structure from its hash table. If 1077 * 'flags' contains PMC_FLAG_REMOVE, then free the process structure. 1078 */ 1079 1080static int 1081pmc_detach_one_process(struct proc *p, struct pmc *pm, int flags) 1082{ 1083 int ri; 1084 struct pmc_process *pp; 1085 1086 sx_assert(&pmc_sx, SX_XLOCKED); 1087 1088 KASSERT(pm != NULL, 1089 ("[pmc,%d] null pm pointer", __LINE__)); 1090 1091 ri = PMC_TO_ROWINDEX(pm); 1092 1093 PMCDBG(PRC,ATT,2, "detach-one pm=%p ri=%d proc=%p (%d, %s) flags=0x%x", 1094 pm, ri, p, p->p_pid, p->p_comm, flags); 1095 1096 if ((pp = pmc_find_process_descriptor(p, 0)) == NULL) 1097 return ESRCH; 1098 1099 if (pp->pp_pmcs[ri].pp_pmc != pm) 1100 return EINVAL; 1101 1102 pmc_unlink_target_process(pm, pp); 1103 1104 /* Issue a detach entry if a log file is configured */ 1105 if (pm->pm_owner->po_flags & PMC_PO_OWNS_LOGFILE) 1106 pmclog_process_pmcdetach(pm, p->p_pid); 1107 1108 /* 1109 * If there are no PMCs targetting this process, we remove its 1110 * descriptor from the target hash table and unset the P_HWPMC 1111 * flag in the struct proc. 1112 */ 1113 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt < (int) md->pmd_npmc, 1114 ("[pmc,%d] Illegal refcnt %d for process struct %p", 1115 __LINE__, pp->pp_refcnt, pp)); 1116 1117 if (pp->pp_refcnt != 0) /* still a target of some PMC */ 1118 return 0; 1119 1120 pmc_remove_process_descriptor(pp); 1121 1122 if (flags & PMC_FLAG_REMOVE) 1123 free(pp, M_PMC); 1124 1125 PROC_LOCK(p); 1126 p->p_flag &= ~P_HWPMC; 1127 PROC_UNLOCK(p); 1128 1129 return 0; 1130} 1131 1132/* 1133 * Detach a process and optionally its descendants from a PMC. 1134 */ 1135 1136static int 1137pmc_detach_process(struct proc *p, struct pmc *pm) 1138{ 1139 struct proc *top; 1140 1141 sx_assert(&pmc_sx, SX_XLOCKED); 1142 1143 PMCDBG(PRC,ATT,1, "detach pm=%p ri=%d proc=%p (%d, %s)", pm, 1144 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 1145 1146 if ((pm->pm_flags & PMC_F_DESCENDANTS) == 0) 1147 return pmc_detach_one_process(p, pm, PMC_FLAG_REMOVE); 1148 1149 /* 1150 * Traverse all children, detaching them from this PMC. We 1151 * ignore errors since we could be detaching a PMC from a 1152 * partially attached proc tree. 1153 */ 1154 1155 sx_slock(&proctree_lock); 1156 1157 top = p; 1158 1159 for (;;) { 1160 (void) pmc_detach_one_process(p, pm, PMC_FLAG_REMOVE); 1161 1162 if (!LIST_EMPTY(&p->p_children)) 1163 p = LIST_FIRST(&p->p_children); 1164 else for (;;) { 1165 if (p == top) 1166 goto done; 1167 if (LIST_NEXT(p, p_sibling)) { 1168 p = LIST_NEXT(p, p_sibling); 1169 break; 1170 } 1171 p = p->p_pptr; 1172 } 1173 } 1174 1175 done: 1176 sx_sunlock(&proctree_lock); 1177 1178 if (LIST_EMPTY(&pm->pm_targets)) 1179 pm->pm_flags &= ~PMC_F_ATTACH_DONE; 1180 1181 return 0; 1182} 1183 1184 1185/* 1186 * Thread context switch IN 1187 */ 1188 1189static void 1190pmc_process_csw_in(struct thread *td) 1191{ 1192 int cpu; 1193 unsigned int adjri, ri; 1194 struct pmc *pm; 1195 struct proc *p; 1196 struct pmc_cpu *pc; 1197 struct pmc_hw *phw; 1198 pmc_value_t newvalue; 1199 struct pmc_process *pp; 1200 struct pmc_classdep *pcd; 1201 1202 p = td->td_proc; 1203 1204 if ((pp = pmc_find_process_descriptor(p, PMC_FLAG_NONE)) == NULL) 1205 return; 1206 1207 KASSERT(pp->pp_proc == td->td_proc, 1208 ("[pmc,%d] not my thread state", __LINE__)); 1209 1210 critical_enter(); /* no preemption from this point */ 1211 1212 cpu = PCPU_GET(cpuid); /* td->td_oncpu is invalid */ 1213 1214 PMCDBG(CSW,SWI,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p, 1215 p->p_pid, p->p_comm, pp); 1216 1217 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 1218 ("[pmc,%d] wierd CPU id %d", __LINE__, cpu)); 1219 1220 pc = pmc_pcpu[cpu]; 1221 1222 for (ri = 0; ri < md->pmd_npmc; ri++) { 1223 1224 if ((pm = pp->pp_pmcs[ri].pp_pmc) == NULL) 1225 continue; 1226 1227 KASSERT(PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)), 1228 ("[pmc,%d] Target PMC in non-virtual mode (%d)", 1229 __LINE__, PMC_TO_MODE(pm))); 1230 1231 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 1232 ("[pmc,%d] Row index mismatch pmc %d != ri %d", 1233 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 1234 1235 /* 1236 * Only PMCs that are marked as 'RUNNING' need 1237 * be placed on hardware. 1238 */ 1239 1240 if (pm->pm_state != PMC_STATE_RUNNING) 1241 continue; 1242 1243 /* increment PMC runcount */ 1244 atomic_add_rel_32(&pm->pm_runcount, 1); 1245 1246 /* configure the HWPMC we are going to use. */ 1247 pcd = pmc_ri_to_classdep(md, ri, &adjri); 1248 pcd->pcd_config_pmc(cpu, adjri, pm); 1249 1250 phw = pc->pc_hwpmcs[ri]; 1251 1252 KASSERT(phw != NULL, 1253 ("[pmc,%d] null hw pointer", __LINE__)); 1254 1255 KASSERT(phw->phw_pmc == pm, 1256 ("[pmc,%d] hw->pmc %p != pmc %p", __LINE__, 1257 phw->phw_pmc, pm)); 1258 1259 /* 1260 * Write out saved value and start the PMC. 1261 * 1262 * Sampling PMCs use a per-process value, while 1263 * counting mode PMCs use a per-pmc value that is 1264 * inherited across descendants. 1265 */ 1266 if (PMC_TO_MODE(pm) == PMC_MODE_TS) { 1267 mtx_pool_lock_spin(pmc_mtxpool, pm); 1268 newvalue = PMC_PCPU_SAVED(cpu,ri) = 1269 pp->pp_pmcs[ri].pp_pmcval; 1270 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1271 } else { 1272 KASSERT(PMC_TO_MODE(pm) == PMC_MODE_TC, 1273 ("[pmc,%d] illegal mode=%d", __LINE__, 1274 PMC_TO_MODE(pm))); 1275 mtx_pool_lock_spin(pmc_mtxpool, pm); 1276 newvalue = PMC_PCPU_SAVED(cpu, ri) = 1277 pm->pm_gv.pm_savedvalue; 1278 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1279 } 1280 1281 PMCDBG(CSW,SWI,1,"cpu=%d ri=%d new=%jd", cpu, ri, newvalue); 1282 1283 pcd->pcd_write_pmc(cpu, adjri, newvalue); 1284 pcd->pcd_start_pmc(cpu, adjri); 1285 } 1286 1287 /* 1288 * perform any other architecture/cpu dependent thread 1289 * switch-in actions. 1290 */ 1291 1292 (void) (*md->pmd_switch_in)(pc, pp); 1293 1294 critical_exit(); 1295 1296} 1297 1298/* 1299 * Thread context switch OUT. 1300 */ 1301 1302static void 1303pmc_process_csw_out(struct thread *td) 1304{ 1305 int cpu; 1306 int64_t tmp; 1307 struct pmc *pm; 1308 struct proc *p; 1309 enum pmc_mode mode; 1310 struct pmc_cpu *pc; 1311 pmc_value_t newvalue; 1312 unsigned int adjri, ri; 1313 struct pmc_process *pp; 1314 struct pmc_classdep *pcd; 1315 1316 1317 /* 1318 * Locate our process descriptor; this may be NULL if 1319 * this process is exiting and we have already removed 1320 * the process from the target process table. 1321 * 1322 * Note that due to kernel preemption, multiple 1323 * context switches may happen while the process is 1324 * exiting. 1325 * 1326 * Note also that if the target process cannot be 1327 * found we still need to deconfigure any PMCs that 1328 * are currently running on hardware. 1329 */ 1330 1331 p = td->td_proc; 1332 pp = pmc_find_process_descriptor(p, PMC_FLAG_NONE); 1333 1334 /* 1335 * save PMCs 1336 */ 1337 1338 critical_enter(); 1339 1340 cpu = PCPU_GET(cpuid); /* td->td_oncpu is invalid */ 1341 1342 PMCDBG(CSW,SWO,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p, 1343 p->p_pid, p->p_comm, pp); 1344 1345 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 1346 ("[pmc,%d wierd CPU id %d", __LINE__, cpu)); 1347 1348 pc = pmc_pcpu[cpu]; 1349 1350 /* 1351 * When a PMC gets unlinked from a target PMC, it will 1352 * be removed from the target's pp_pmc[] array. 1353 * 1354 * However, on a MP system, the target could have been 1355 * executing on another CPU at the time of the unlink. 1356 * So, at context switch OUT time, we need to look at 1357 * the hardware to determine if a PMC is scheduled on 1358 * it. 1359 */ 1360 1361 for (ri = 0; ri < md->pmd_npmc; ri++) { 1362 1363 pcd = pmc_ri_to_classdep(md, ri, &adjri); 1364 pm = NULL; 1365 (void) (*pcd->pcd_get_config)(cpu, adjri, &pm); 1366 1367 if (pm == NULL) /* nothing at this row index */ 1368 continue; 1369 1370 mode = PMC_TO_MODE(pm); 1371 if (!PMC_IS_VIRTUAL_MODE(mode)) 1372 continue; /* not a process virtual PMC */ 1373 1374 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 1375 ("[pmc,%d] ri mismatch pmc(%d) ri(%d)", 1376 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 1377 1378 /* Stop hardware if not already stopped */ 1379 if (pm->pm_stalled == 0) 1380 pcd->pcd_stop_pmc(cpu, adjri); 1381 1382 /* reduce this PMC's runcount */ 1383 atomic_subtract_rel_32(&pm->pm_runcount, 1); 1384 1385 /* 1386 * If this PMC is associated with this process, 1387 * save the reading. 1388 */ 1389 1390 if (pp != NULL && pp->pp_pmcs[ri].pp_pmc != NULL) { 1391 1392 KASSERT(pm == pp->pp_pmcs[ri].pp_pmc, 1393 ("[pmc,%d] pm %p != pp_pmcs[%d] %p", __LINE__, 1394 pm, ri, pp->pp_pmcs[ri].pp_pmc)); 1395 1396 KASSERT(pp->pp_refcnt > 0, 1397 ("[pmc,%d] pp refcnt = %d", __LINE__, 1398 pp->pp_refcnt)); 1399 1400 pcd->pcd_read_pmc(cpu, adjri, &newvalue); 1401 1402 tmp = newvalue - PMC_PCPU_SAVED(cpu,ri); 1403 1404 PMCDBG(CSW,SWI,1,"cpu=%d ri=%d tmp=%jd", cpu, ri, 1405 tmp); 1406 1407 if (mode == PMC_MODE_TS) { 1408 1409 /* 1410 * For sampling process-virtual PMCs, 1411 * we expect the count to be 1412 * decreasing as the 'value' 1413 * programmed into the PMC is the 1414 * number of events to be seen till 1415 * the next sampling interrupt. 1416 */ 1417 if (tmp < 0) 1418 tmp += pm->pm_sc.pm_reloadcount; 1419 mtx_pool_lock_spin(pmc_mtxpool, pm); 1420 pp->pp_pmcs[ri].pp_pmcval -= tmp; 1421 if ((int64_t) pp->pp_pmcs[ri].pp_pmcval < 0) 1422 pp->pp_pmcs[ri].pp_pmcval += 1423 pm->pm_sc.pm_reloadcount; 1424 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1425 1426 } else { 1427 1428 /* 1429 * For counting process-virtual PMCs, 1430 * we expect the count to be 1431 * increasing monotonically, modulo a 64 1432 * bit wraparound. 1433 */ 1434 KASSERT((int64_t) tmp >= 0, 1435 ("[pmc,%d] negative increment cpu=%d " 1436 "ri=%d newvalue=%jx saved=%jx " 1437 "incr=%jx", __LINE__, cpu, ri, 1438 newvalue, PMC_PCPU_SAVED(cpu,ri), tmp)); 1439 1440 mtx_pool_lock_spin(pmc_mtxpool, pm); 1441 pm->pm_gv.pm_savedvalue += tmp; 1442 pp->pp_pmcs[ri].pp_pmcval += tmp; 1443 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1444 1445 if (pm->pm_flags & PMC_F_LOG_PROCCSW) 1446 pmclog_process_proccsw(pm, pp, tmp); 1447 } 1448 } 1449 1450 /* mark hardware as free */ 1451 pcd->pcd_config_pmc(cpu, adjri, NULL); 1452 } 1453 1454 /* 1455 * perform any other architecture/cpu dependent thread 1456 * switch out functions. 1457 */ 1458 1459 (void) (*md->pmd_switch_out)(pc, pp); 1460 1461 critical_exit(); 1462} 1463 1464/* 1465 * Log a KLD operation. 1466 */ 1467 1468static void 1469pmc_process_kld_load(struct pmckern_map_in *pkm) 1470{ 1471 struct pmc_owner *po; 1472 1473 sx_assert(&pmc_sx, SX_LOCKED); 1474 1475 /* 1476 * Notify owners of system sampling PMCs about KLD operations. 1477 */ 1478 1479 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1480 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1481 pmclog_process_map_in(po, (pid_t) -1, pkm->pm_address, 1482 (char *) pkm->pm_file); 1483 1484 /* 1485 * TODO: Notify owners of (all) process-sampling PMCs too. 1486 */ 1487 1488 return; 1489} 1490 1491static void 1492pmc_process_kld_unload(struct pmckern_map_out *pkm) 1493{ 1494 struct pmc_owner *po; 1495 1496 sx_assert(&pmc_sx, SX_LOCKED); 1497 1498 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1499 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1500 pmclog_process_map_out(po, (pid_t) -1, 1501 pkm->pm_address, pkm->pm_address + pkm->pm_size); 1502 1503 /* 1504 * TODO: Notify owners of process-sampling PMCs. 1505 */ 1506} 1507 1508/* 1509 * A mapping change for a process. 1510 */ 1511 1512static void 1513pmc_process_mmap(struct thread *td, struct pmckern_map_in *pkm) 1514{ 1515 int ri; 1516 pid_t pid; 1517 char *fullpath, *freepath; 1518 const struct pmc *pm; 1519 struct pmc_owner *po; 1520 const struct pmc_process *pp; 1521 1522 freepath = fullpath = NULL; 1523 pmc_getfilename((struct vnode *) pkm->pm_file, &fullpath, &freepath); 1524 1525 pid = td->td_proc->p_pid; 1526 1527 /* Inform owners of all system-wide sampling PMCs. */ 1528 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1529 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1530 pmclog_process_map_in(po, pid, pkm->pm_address, fullpath); 1531 1532 if ((pp = pmc_find_process_descriptor(td->td_proc, 0)) == NULL) 1533 goto done; 1534 1535 /* 1536 * Inform sampling PMC owners tracking this process. 1537 */ 1538 for (ri = 0; ri < md->pmd_npmc; ri++) 1539 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL && 1540 PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 1541 pmclog_process_map_in(pm->pm_owner, 1542 pid, pkm->pm_address, fullpath); 1543 1544 done: 1545 if (freepath) 1546 free(freepath, M_TEMP); 1547} 1548 1549 1550/* 1551 * Log an munmap request. 1552 */ 1553 1554static void 1555pmc_process_munmap(struct thread *td, struct pmckern_map_out *pkm) 1556{ 1557 int ri; 1558 pid_t pid; 1559 struct pmc_owner *po; 1560 const struct pmc *pm; 1561 const struct pmc_process *pp; 1562 1563 pid = td->td_proc->p_pid; 1564 1565 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1566 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1567 pmclog_process_map_out(po, pid, pkm->pm_address, 1568 pkm->pm_address + pkm->pm_size); 1569 1570 if ((pp = pmc_find_process_descriptor(td->td_proc, 0)) == NULL) 1571 return; 1572 1573 for (ri = 0; ri < md->pmd_npmc; ri++) 1574 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL && 1575 PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 1576 pmclog_process_map_out(pm->pm_owner, pid, 1577 pkm->pm_address, pkm->pm_address + pkm->pm_size); 1578} 1579 1580/* 1581 * Log mapping information about the kernel. 1582 */ 1583 1584static void 1585pmc_log_kernel_mappings(struct pmc *pm) 1586{ 1587 struct pmc_owner *po; 1588 struct pmckern_map_in *km, *kmbase; 1589 1590 sx_assert(&pmc_sx, SX_LOCKED); 1591 KASSERT(PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)), 1592 ("[pmc,%d] non-sampling PMC (%p) desires mapping information", 1593 __LINE__, (void *) pm)); 1594 1595 po = pm->pm_owner; 1596 1597 if (po->po_flags & PMC_PO_INITIAL_MAPPINGS_DONE) 1598 return; 1599 1600 /* 1601 * Log the current set of kernel modules. 1602 */ 1603 kmbase = linker_hwpmc_list_objects(); 1604 for (km = kmbase; km->pm_file != NULL; km++) { 1605 PMCDBG(LOG,REG,1,"%s %p", (char *) km->pm_file, 1606 (void *) km->pm_address); 1607 pmclog_process_map_in(po, (pid_t) -1, km->pm_address, 1608 km->pm_file); 1609 } 1610 free(kmbase, M_LINKER); 1611 1612 po->po_flags |= PMC_PO_INITIAL_MAPPINGS_DONE; 1613} 1614 1615/* 1616 * Log the mappings for a single process. 1617 */ 1618 1619static void 1620pmc_log_process_mappings(struct pmc_owner *po, struct proc *p) 1621{ 1622} 1623 1624/* 1625 * Log mappings for all processes in the system. 1626 */ 1627 1628static void 1629pmc_log_all_process_mappings(struct pmc_owner *po) 1630{ 1631 struct proc *p, *top; 1632 1633 sx_assert(&pmc_sx, SX_XLOCKED); 1634 1635 if ((p = pfind(1)) == NULL) 1636 panic("[pmc,%d] Cannot find init", __LINE__); 1637 1638 PROC_UNLOCK(p); 1639 1640 sx_slock(&proctree_lock); 1641 1642 top = p; 1643 1644 for (;;) { 1645 pmc_log_process_mappings(po, p); 1646 if (!LIST_EMPTY(&p->p_children)) 1647 p = LIST_FIRST(&p->p_children); 1648 else for (;;) { 1649 if (p == top) 1650 goto done; 1651 if (LIST_NEXT(p, p_sibling)) { 1652 p = LIST_NEXT(p, p_sibling); 1653 break; 1654 } 1655 p = p->p_pptr; 1656 } 1657 } 1658 done: 1659 sx_sunlock(&proctree_lock); 1660} 1661 1662/* 1663 * The 'hook' invoked from the kernel proper 1664 */ 1665 1666 1667#ifdef DEBUG 1668const char *pmc_hooknames[] = { 1669 /* these strings correspond to PMC_FN_* in <sys/pmckern.h> */ 1670 "", 1671 "EXEC", 1672 "CSW-IN", 1673 "CSW-OUT", 1674 "SAMPLE", 1675 "KLDLOAD", 1676 "KLDUNLOAD", 1677 "MMAP", 1678 "MUNMAP", 1679 "CALLCHAIN" 1680}; 1681#endif 1682 1683static int 1684pmc_hook_handler(struct thread *td, int function, void *arg) 1685{ 1686 1687 PMCDBG(MOD,PMH,1, "hook td=%p func=%d \"%s\" arg=%p", td, function, 1688 pmc_hooknames[function], arg); 1689 1690 switch (function) 1691 { 1692 1693 /* 1694 * Process exec() 1695 */ 1696 1697 case PMC_FN_PROCESS_EXEC: 1698 { 1699 char *fullpath, *freepath; 1700 unsigned int ri; 1701 int is_using_hwpmcs; 1702 struct pmc *pm; 1703 struct proc *p; 1704 struct pmc_owner *po; 1705 struct pmc_process *pp; 1706 struct pmckern_procexec *pk; 1707 1708 sx_assert(&pmc_sx, SX_XLOCKED); 1709 1710 p = td->td_proc; 1711 pmc_getfilename(p->p_textvp, &fullpath, &freepath); 1712 1713 pk = (struct pmckern_procexec *) arg; 1714 1715 /* Inform owners of SS mode PMCs of the exec event. */ 1716 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1717 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1718 pmclog_process_procexec(po, PMC_ID_INVALID, 1719 p->p_pid, pk->pm_entryaddr, fullpath); 1720 1721 PROC_LOCK(p); 1722 is_using_hwpmcs = p->p_flag & P_HWPMC; 1723 PROC_UNLOCK(p); 1724 1725 if (!is_using_hwpmcs) { 1726 if (freepath) 1727 free(freepath, M_TEMP); 1728 break; 1729 } 1730 1731 /* 1732 * PMCs are not inherited across an exec(): remove any 1733 * PMCs that this process is the owner of. 1734 */ 1735 1736 if ((po = pmc_find_owner_descriptor(p)) != NULL) { 1737 pmc_remove_owner(po); 1738 pmc_destroy_owner_descriptor(po); 1739 } 1740 1741 /* 1742 * If the process being exec'ed is not the target of any 1743 * PMC, we are done. 1744 */ 1745 if ((pp = pmc_find_process_descriptor(p, 0)) == NULL) { 1746 if (freepath) 1747 free(freepath, M_TEMP); 1748 break; 1749 } 1750 1751 /* 1752 * Log the exec event to all monitoring owners. Skip 1753 * owners who have already recieved the event because 1754 * they had system sampling PMCs active. 1755 */ 1756 for (ri = 0; ri < md->pmd_npmc; ri++) 1757 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) { 1758 po = pm->pm_owner; 1759 if (po->po_sscount == 0 && 1760 po->po_flags & PMC_PO_OWNS_LOGFILE) 1761 pmclog_process_procexec(po, pm->pm_id, 1762 p->p_pid, pk->pm_entryaddr, 1763 fullpath); 1764 } 1765 1766 if (freepath) 1767 free(freepath, M_TEMP); 1768 1769 1770 PMCDBG(PRC,EXC,1, "exec proc=%p (%d, %s) cred-changed=%d", 1771 p, p->p_pid, p->p_comm, pk->pm_credentialschanged); 1772 1773 if (pk->pm_credentialschanged == 0) /* no change */ 1774 break; 1775 1776 /* 1777 * If the newly exec()'ed process has a different credential 1778 * than before, allow it to be the target of a PMC only if 1779 * the PMC's owner has sufficient priviledge. 1780 */ 1781 1782 for (ri = 0; ri < md->pmd_npmc; ri++) 1783 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) 1784 if (pmc_can_attach(pm, td->td_proc) != 0) 1785 pmc_detach_one_process(td->td_proc, 1786 pm, PMC_FLAG_NONE); 1787 1788 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt < (int) md->pmd_npmc, 1789 ("[pmc,%d] Illegal ref count %d on pp %p", __LINE__, 1790 pp->pp_refcnt, pp)); 1791 1792 /* 1793 * If this process is no longer the target of any 1794 * PMCs, we can remove the process entry and free 1795 * up space. 1796 */ 1797 1798 if (pp->pp_refcnt == 0) { 1799 pmc_remove_process_descriptor(pp); 1800 free(pp, M_PMC); 1801 break; 1802 } 1803 1804 } 1805 break; 1806 1807 case PMC_FN_CSW_IN: 1808 pmc_process_csw_in(td); 1809 break; 1810 1811 case PMC_FN_CSW_OUT: 1812 pmc_process_csw_out(td); 1813 break; 1814 1815 /* 1816 * Process accumulated PC samples. 1817 * 1818 * This function is expected to be called by hardclock() for 1819 * each CPU that has accumulated PC samples. 1820 * 1821 * This function is to be executed on the CPU whose samples 1822 * are being processed. 1823 */ 1824 case PMC_FN_DO_SAMPLES: 1825 1826 /* 1827 * Clear the cpu specific bit in the CPU mask before 1828 * do the rest of the processing. If the NMI handler 1829 * gets invoked after the "atomic_clear_int()" call 1830 * below but before "pmc_process_samples()" gets 1831 * around to processing the interrupt, then we will 1832 * come back here at the next hardclock() tick (and 1833 * may find nothing to do if "pmc_process_samples()" 1834 * had already processed the interrupt). We don't 1835 * lose the interrupt sample. 1836 */ 1837 atomic_clear_int(&pmc_cpumask, (1 << PCPU_GET(cpuid))); 1838 pmc_process_samples(PCPU_GET(cpuid)); 1839 break; 1840 1841 1842 case PMC_FN_KLD_LOAD: 1843 sx_assert(&pmc_sx, SX_LOCKED); 1844 pmc_process_kld_load((struct pmckern_map_in *) arg); 1845 break; 1846 1847 case PMC_FN_KLD_UNLOAD: 1848 sx_assert(&pmc_sx, SX_LOCKED); 1849 pmc_process_kld_unload((struct pmckern_map_out *) arg); 1850 break; 1851 1852 case PMC_FN_MMAP: 1853 sx_assert(&pmc_sx, SX_LOCKED); 1854 pmc_process_mmap(td, (struct pmckern_map_in *) arg); 1855 break; 1856 1857 case PMC_FN_MUNMAP: 1858 sx_assert(&pmc_sx, SX_LOCKED); 1859 pmc_process_munmap(td, (struct pmckern_map_out *) arg); 1860 break; 1861 1862 case PMC_FN_USER_CALLCHAIN: 1863 /* 1864 * Record a call chain. 1865 */ 1866 pmc_capture_user_callchain(PCPU_GET(cpuid), 1867 (struct trapframe *) arg); 1868 break; 1869 1870 default: 1871#ifdef DEBUG 1872 KASSERT(0, ("[pmc,%d] unknown hook %d\n", __LINE__, function)); 1873#endif 1874 break; 1875 1876 } 1877 1878 return 0; 1879} 1880 1881/* 1882 * allocate a 'struct pmc_owner' descriptor in the owner hash table. 1883 */ 1884 1885static struct pmc_owner * 1886pmc_allocate_owner_descriptor(struct proc *p) 1887{ 1888 uint32_t hindex; 1889 struct pmc_owner *po; 1890 struct pmc_ownerhash *poh; 1891 1892 hindex = PMC_HASH_PTR(p, pmc_ownerhashmask); 1893 poh = &pmc_ownerhash[hindex]; 1894 1895 /* allocate space for N pointers and one descriptor struct */ 1896 po = malloc(sizeof(struct pmc_owner), M_PMC, M_WAITOK|M_ZERO); 1897 po->po_sscount = po->po_error = po->po_flags = 0; 1898 po->po_file = NULL; 1899 po->po_owner = p; 1900 po->po_kthread = NULL; 1901 LIST_INIT(&po->po_pmcs); 1902 LIST_INSERT_HEAD(poh, po, po_next); /* insert into hash table */ 1903 1904 TAILQ_INIT(&po->po_logbuffers); 1905 mtx_init(&po->po_mtx, "pmc-owner-mtx", "pmc-per-proc", MTX_SPIN); 1906 1907 PMCDBG(OWN,ALL,1, "allocate-owner proc=%p (%d, %s) pmc-owner=%p", 1908 p, p->p_pid, p->p_comm, po); 1909 1910 return po; 1911} 1912 1913static void 1914pmc_destroy_owner_descriptor(struct pmc_owner *po) 1915{ 1916 1917 PMCDBG(OWN,REL,1, "destroy-owner po=%p proc=%p (%d, %s)", 1918 po, po->po_owner, po->po_owner->p_pid, po->po_owner->p_comm); 1919 1920 mtx_destroy(&po->po_mtx); 1921 free(po, M_PMC); 1922} 1923 1924/* 1925 * find the descriptor corresponding to process 'p', adding or removing it 1926 * as specified by 'mode'. 1927 */ 1928 1929static struct pmc_process * 1930pmc_find_process_descriptor(struct proc *p, uint32_t mode) 1931{ 1932 uint32_t hindex; 1933 struct pmc_process *pp, *ppnew; 1934 struct pmc_processhash *pph; 1935 1936 hindex = PMC_HASH_PTR(p, pmc_processhashmask); 1937 pph = &pmc_processhash[hindex]; 1938 1939 ppnew = NULL; 1940 1941 /* 1942 * Pre-allocate memory in the FIND_ALLOCATE case since we 1943 * cannot call malloc(9) once we hold a spin lock. 1944 */ 1945 if (mode & PMC_FLAG_ALLOCATE) 1946 ppnew = malloc(sizeof(struct pmc_process) + md->pmd_npmc * 1947 sizeof(struct pmc_targetstate), M_PMC, M_WAITOK|M_ZERO); 1948 1949 mtx_lock_spin(&pmc_processhash_mtx); 1950 LIST_FOREACH(pp, pph, pp_next) 1951 if (pp->pp_proc == p) 1952 break; 1953 1954 if ((mode & PMC_FLAG_REMOVE) && pp != NULL) 1955 LIST_REMOVE(pp, pp_next); 1956 1957 if ((mode & PMC_FLAG_ALLOCATE) && pp == NULL && 1958 ppnew != NULL) { 1959 ppnew->pp_proc = p; 1960 LIST_INSERT_HEAD(pph, ppnew, pp_next); 1961 pp = ppnew; 1962 ppnew = NULL; 1963 } 1964 mtx_unlock_spin(&pmc_processhash_mtx); 1965 1966 if (pp != NULL && ppnew != NULL) 1967 free(ppnew, M_PMC); 1968 1969 return pp; 1970} 1971 1972/* 1973 * remove a process descriptor from the process hash table. 1974 */ 1975 1976static void 1977pmc_remove_process_descriptor(struct pmc_process *pp) 1978{ 1979 KASSERT(pp->pp_refcnt == 0, 1980 ("[pmc,%d] Removing process descriptor %p with count %d", 1981 __LINE__, pp, pp->pp_refcnt)); 1982 1983 mtx_lock_spin(&pmc_processhash_mtx); 1984 LIST_REMOVE(pp, pp_next); 1985 mtx_unlock_spin(&pmc_processhash_mtx); 1986} 1987 1988 1989/* 1990 * find an owner descriptor corresponding to proc 'p' 1991 */ 1992 1993static struct pmc_owner * 1994pmc_find_owner_descriptor(struct proc *p) 1995{ 1996 uint32_t hindex; 1997 struct pmc_owner *po; 1998 struct pmc_ownerhash *poh; 1999 2000 hindex = PMC_HASH_PTR(p, pmc_ownerhashmask); 2001 poh = &pmc_ownerhash[hindex]; 2002 2003 po = NULL; 2004 LIST_FOREACH(po, poh, po_next) 2005 if (po->po_owner == p) 2006 break; 2007 2008 PMCDBG(OWN,FND,1, "find-owner proc=%p (%d, %s) hindex=0x%x -> " 2009 "pmc-owner=%p", p, p->p_pid, p->p_comm, hindex, po); 2010 2011 return po; 2012} 2013 2014/* 2015 * pmc_allocate_pmc_descriptor 2016 * 2017 * Allocate a pmc descriptor and initialize its 2018 * fields. 2019 */ 2020 2021static struct pmc * 2022pmc_allocate_pmc_descriptor(void) 2023{ 2024 struct pmc *pmc; 2025 2026 pmc = malloc(sizeof(struct pmc), M_PMC, M_WAITOK|M_ZERO); 2027 2028 if (pmc != NULL) { 2029 pmc->pm_owner = NULL; 2030 LIST_INIT(&pmc->pm_targets); 2031 } 2032 2033 PMCDBG(PMC,ALL,1, "allocate-pmc -> pmc=%p", pmc); 2034 2035 return pmc; 2036} 2037 2038/* 2039 * Destroy a pmc descriptor. 2040 */ 2041 2042static void 2043pmc_destroy_pmc_descriptor(struct pmc *pm) 2044{ 2045 (void) pm; 2046 2047#ifdef DEBUG 2048 KASSERT(pm->pm_state == PMC_STATE_DELETED || 2049 pm->pm_state == PMC_STATE_FREE, 2050 ("[pmc,%d] destroying non-deleted PMC", __LINE__)); 2051 KASSERT(LIST_EMPTY(&pm->pm_targets), 2052 ("[pmc,%d] destroying pmc with targets", __LINE__)); 2053 KASSERT(pm->pm_owner == NULL, 2054 ("[pmc,%d] destroying pmc attached to an owner", __LINE__)); 2055 KASSERT(pm->pm_runcount == 0, 2056 ("[pmc,%d] pmc has non-zero run count %d", __LINE__, 2057 pm->pm_runcount)); 2058#endif 2059} 2060 2061static void 2062pmc_wait_for_pmc_idle(struct pmc *pm) 2063{ 2064#ifdef DEBUG 2065 volatile int maxloop; 2066 2067 maxloop = 100 * pmc_cpu_max(); 2068#endif 2069 2070 /* 2071 * Loop (with a forced context switch) till the PMC's runcount 2072 * comes down to zero. 2073 */ 2074 while (atomic_load_acq_32(&pm->pm_runcount) > 0) { 2075#ifdef DEBUG 2076 maxloop--; 2077 KASSERT(maxloop > 0, 2078 ("[pmc,%d] (ri%d, rc%d) waiting too long for " 2079 "pmc to be free", __LINE__, 2080 PMC_TO_ROWINDEX(pm), pm->pm_runcount)); 2081#endif 2082 pmc_force_context_switch(); 2083 } 2084} 2085 2086/* 2087 * This function does the following things: 2088 * 2089 * - detaches the PMC from hardware 2090 * - unlinks all target threads that were attached to it 2091 * - removes the PMC from its owner's list 2092 * - destroy's the PMC private mutex 2093 * 2094 * Once this function completes, the given pmc pointer can be safely 2095 * FREE'd by the caller. 2096 */ 2097 2098static void 2099pmc_release_pmc_descriptor(struct pmc *pm) 2100{ 2101 enum pmc_mode mode; 2102 struct pmc_hw *phw; 2103 u_int adjri, ri, cpu; 2104 struct pmc_owner *po; 2105 struct pmc_binding pb; 2106 struct pmc_process *pp; 2107 struct pmc_classdep *pcd; 2108 struct pmc_target *ptgt, *tmp; 2109 2110 sx_assert(&pmc_sx, SX_XLOCKED); 2111 2112 KASSERT(pm, ("[pmc,%d] null pmc", __LINE__)); 2113 2114 ri = PMC_TO_ROWINDEX(pm); 2115 pcd = pmc_ri_to_classdep(md, ri, &adjri); 2116 mode = PMC_TO_MODE(pm); 2117 2118 PMCDBG(PMC,REL,1, "release-pmc pmc=%p ri=%d mode=%d", pm, ri, 2119 mode); 2120 2121 /* 2122 * First, we take the PMC off hardware. 2123 */ 2124 cpu = 0; 2125 if (PMC_IS_SYSTEM_MODE(mode)) { 2126 2127 /* 2128 * A system mode PMC runs on a specific CPU. Switch 2129 * to this CPU and turn hardware off. 2130 */ 2131 pmc_save_cpu_binding(&pb); 2132 2133 cpu = PMC_TO_CPU(pm); 2134 2135 pmc_select_cpu(cpu); 2136 2137 /* switch off non-stalled CPUs */ 2138 if (pm->pm_state == PMC_STATE_RUNNING && 2139 pm->pm_stalled == 0) { 2140 2141 phw = pmc_pcpu[cpu]->pc_hwpmcs[ri]; 2142 2143 KASSERT(phw->phw_pmc == pm, 2144 ("[pmc, %d] pmc ptr ri(%d) hw(%p) pm(%p)", 2145 __LINE__, ri, phw->phw_pmc, pm)); 2146 PMCDBG(PMC,REL,2, "stopping cpu=%d ri=%d", cpu, ri); 2147 2148 critical_enter(); 2149 pcd->pcd_stop_pmc(cpu, adjri); 2150 critical_exit(); 2151 } 2152 2153 PMCDBG(PMC,REL,2, "decfg cpu=%d ri=%d", cpu, ri); 2154 2155 critical_enter(); 2156 pcd->pcd_config_pmc(cpu, adjri, NULL); 2157 critical_exit(); 2158 2159 /* adjust the global and process count of SS mode PMCs */ 2160 if (mode == PMC_MODE_SS && pm->pm_state == PMC_STATE_RUNNING) { 2161 po = pm->pm_owner; 2162 po->po_sscount--; 2163 if (po->po_sscount == 0) { 2164 atomic_subtract_rel_int(&pmc_ss_count, 1); 2165 LIST_REMOVE(po, po_ssnext); 2166 } 2167 } 2168 2169 pm->pm_state = PMC_STATE_DELETED; 2170 2171 pmc_restore_cpu_binding(&pb); 2172 2173 /* 2174 * We could have references to this PMC structure in 2175 * the per-cpu sample queues. Wait for the queue to 2176 * drain. 2177 */ 2178 pmc_wait_for_pmc_idle(pm); 2179 2180 } else if (PMC_IS_VIRTUAL_MODE(mode)) { 2181 2182 /* 2183 * A virtual PMC could be running on multiple CPUs at 2184 * a given instant. 2185 * 2186 * By marking its state as DELETED, we ensure that 2187 * this PMC is never further scheduled on hardware. 2188 * 2189 * Then we wait till all CPUs are done with this PMC. 2190 */ 2191 pm->pm_state = PMC_STATE_DELETED; 2192 2193 2194 /* Wait for the PMCs runcount to come to zero. */ 2195 pmc_wait_for_pmc_idle(pm); 2196 2197 /* 2198 * At this point the PMC is off all CPUs and cannot be 2199 * freshly scheduled onto a CPU. It is now safe to 2200 * unlink all targets from this PMC. If a 2201 * process-record's refcount falls to zero, we remove 2202 * it from the hash table. The module-wide SX lock 2203 * protects us from races. 2204 */ 2205 LIST_FOREACH_SAFE(ptgt, &pm->pm_targets, pt_next, tmp) { 2206 pp = ptgt->pt_process; 2207 pmc_unlink_target_process(pm, pp); /* frees 'ptgt' */ 2208 2209 PMCDBG(PMC,REL,3, "pp->refcnt=%d", pp->pp_refcnt); 2210 2211 /* 2212 * If the target process record shows that no 2213 * PMCs are attached to it, reclaim its space. 2214 */ 2215 2216 if (pp->pp_refcnt == 0) { 2217 pmc_remove_process_descriptor(pp); 2218 free(pp, M_PMC); 2219 } 2220 } 2221 2222 cpu = curthread->td_oncpu; /* setup cpu for pmd_release() */ 2223 2224 } 2225 2226 /* 2227 * Release any MD resources 2228 */ 2229 (void) pcd->pcd_release_pmc(cpu, adjri, pm); 2230 2231 /* 2232 * Update row disposition 2233 */ 2234 2235 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) 2236 PMC_UNMARK_ROW_STANDALONE(ri); 2237 else 2238 PMC_UNMARK_ROW_THREAD(ri); 2239 2240 /* unlink from the owner's list */ 2241 if (pm->pm_owner) { 2242 LIST_REMOVE(pm, pm_next); 2243 pm->pm_owner = NULL; 2244 } 2245 2246 pmc_destroy_pmc_descriptor(pm); 2247} 2248 2249/* 2250 * Register an owner and a pmc. 2251 */ 2252 2253static int 2254pmc_register_owner(struct proc *p, struct pmc *pmc) 2255{ 2256 struct pmc_owner *po; 2257 2258 sx_assert(&pmc_sx, SX_XLOCKED); 2259 2260 if ((po = pmc_find_owner_descriptor(p)) == NULL) 2261 if ((po = pmc_allocate_owner_descriptor(p)) == NULL) 2262 return ENOMEM; 2263 2264 KASSERT(pmc->pm_owner == NULL, 2265 ("[pmc,%d] attempting to own an initialized PMC", __LINE__)); 2266 pmc->pm_owner = po; 2267 2268 LIST_INSERT_HEAD(&po->po_pmcs, pmc, pm_next); 2269 2270 PROC_LOCK(p); 2271 p->p_flag |= P_HWPMC; 2272 PROC_UNLOCK(p); 2273 2274 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 2275 pmclog_process_pmcallocate(pmc); 2276 2277 PMCDBG(PMC,REG,1, "register-owner pmc-owner=%p pmc=%p", 2278 po, pmc); 2279 2280 return 0; 2281} 2282 2283/* 2284 * Return the current row disposition: 2285 * == 0 => FREE 2286 * > 0 => PROCESS MODE 2287 * < 0 => SYSTEM MODE 2288 */ 2289 2290int 2291pmc_getrowdisp(int ri) 2292{ 2293 return pmc_pmcdisp[ri]; 2294} 2295 2296/* 2297 * Check if a PMC at row index 'ri' can be allocated to the current 2298 * process. 2299 * 2300 * Allocation can fail if: 2301 * - the current process is already being profiled by a PMC at index 'ri', 2302 * attached to it via OP_PMCATTACH. 2303 * - the current process has already allocated a PMC at index 'ri' 2304 * via OP_ALLOCATE. 2305 */ 2306 2307static int 2308pmc_can_allocate_rowindex(struct proc *p, unsigned int ri, int cpu) 2309{ 2310 enum pmc_mode mode; 2311 struct pmc *pm; 2312 struct pmc_owner *po; 2313 struct pmc_process *pp; 2314 2315 PMCDBG(PMC,ALR,1, "can-allocate-rowindex proc=%p (%d, %s) ri=%d " 2316 "cpu=%d", p, p->p_pid, p->p_comm, ri, cpu); 2317 2318 /* 2319 * We shouldn't have already allocated a process-mode PMC at 2320 * row index 'ri'. 2321 * 2322 * We shouldn't have allocated a system-wide PMC on the same 2323 * CPU and same RI. 2324 */ 2325 if ((po = pmc_find_owner_descriptor(p)) != NULL) 2326 LIST_FOREACH(pm, &po->po_pmcs, pm_next) { 2327 if (PMC_TO_ROWINDEX(pm) == ri) { 2328 mode = PMC_TO_MODE(pm); 2329 if (PMC_IS_VIRTUAL_MODE(mode)) 2330 return EEXIST; 2331 if (PMC_IS_SYSTEM_MODE(mode) && 2332 (int) PMC_TO_CPU(pm) == cpu) 2333 return EEXIST; 2334 } 2335 } 2336 2337 /* 2338 * We also shouldn't be the target of any PMC at this index 2339 * since otherwise a PMC_ATTACH to ourselves will fail. 2340 */ 2341 if ((pp = pmc_find_process_descriptor(p, 0)) != NULL) 2342 if (pp->pp_pmcs[ri].pp_pmc) 2343 return EEXIST; 2344 2345 PMCDBG(PMC,ALR,2, "can-allocate-rowindex proc=%p (%d, %s) ri=%d ok", 2346 p, p->p_pid, p->p_comm, ri); 2347 2348 return 0; 2349} 2350 2351/* 2352 * Check if a given PMC at row index 'ri' can be currently used in 2353 * mode 'mode'. 2354 */ 2355 2356static int 2357pmc_can_allocate_row(int ri, enum pmc_mode mode) 2358{ 2359 enum pmc_disp disp; 2360 2361 sx_assert(&pmc_sx, SX_XLOCKED); 2362 2363 PMCDBG(PMC,ALR,1, "can-allocate-row ri=%d mode=%d", ri, mode); 2364 2365 if (PMC_IS_SYSTEM_MODE(mode)) 2366 disp = PMC_DISP_STANDALONE; 2367 else 2368 disp = PMC_DISP_THREAD; 2369 2370 /* 2371 * check disposition for PMC row 'ri': 2372 * 2373 * Expected disposition Row-disposition Result 2374 * 2375 * STANDALONE STANDALONE or FREE proceed 2376 * STANDALONE THREAD fail 2377 * THREAD THREAD or FREE proceed 2378 * THREAD STANDALONE fail 2379 */ 2380 2381 if (!PMC_ROW_DISP_IS_FREE(ri) && 2382 !(disp == PMC_DISP_THREAD && PMC_ROW_DISP_IS_THREAD(ri)) && 2383 !(disp == PMC_DISP_STANDALONE && PMC_ROW_DISP_IS_STANDALONE(ri))) 2384 return EBUSY; 2385 2386 /* 2387 * All OK 2388 */ 2389 2390 PMCDBG(PMC,ALR,2, "can-allocate-row ri=%d mode=%d ok", ri, mode); 2391 2392 return 0; 2393 2394} 2395 2396/* 2397 * Find a PMC descriptor with user handle 'pmcid' for thread 'td'. 2398 */ 2399 2400static struct pmc * 2401pmc_find_pmc_descriptor_in_process(struct pmc_owner *po, pmc_id_t pmcid) 2402{ 2403 struct pmc *pm; 2404 2405 KASSERT(PMC_ID_TO_ROWINDEX(pmcid) < md->pmd_npmc, 2406 ("[pmc,%d] Illegal pmc index %d (max %d)", __LINE__, 2407 PMC_ID_TO_ROWINDEX(pmcid), md->pmd_npmc)); 2408 2409 LIST_FOREACH(pm, &po->po_pmcs, pm_next) 2410 if (pm->pm_id == pmcid) 2411 return pm; 2412 2413 return NULL; 2414} 2415 2416static int 2417pmc_find_pmc(pmc_id_t pmcid, struct pmc **pmc) 2418{ 2419 2420 struct pmc *pm; 2421 struct pmc_owner *po; 2422 2423 PMCDBG(PMC,FND,1, "find-pmc id=%d", pmcid); 2424 2425 if ((po = pmc_find_owner_descriptor(curthread->td_proc)) == NULL) 2426 return ESRCH; 2427 2428 if ((pm = pmc_find_pmc_descriptor_in_process(po, pmcid)) == NULL) 2429 return EINVAL; 2430 2431 PMCDBG(PMC,FND,2, "find-pmc id=%d -> pmc=%p", pmcid, pm); 2432 2433 *pmc = pm; 2434 return 0; 2435} 2436 2437/* 2438 * Start a PMC. 2439 */ 2440 2441static int 2442pmc_start(struct pmc *pm) 2443{ 2444 enum pmc_mode mode; 2445 struct pmc_owner *po; 2446 struct pmc_binding pb; 2447 struct pmc_classdep *pcd; 2448 int adjri, error, cpu, ri; 2449 2450 KASSERT(pm != NULL, 2451 ("[pmc,%d] null pm", __LINE__)); 2452 2453 mode = PMC_TO_MODE(pm); 2454 ri = PMC_TO_ROWINDEX(pm); 2455 pcd = pmc_ri_to_classdep(md, ri, &adjri); 2456 2457 error = 0; 2458 2459 PMCDBG(PMC,OPS,1, "start pmc=%p mode=%d ri=%d", pm, mode, ri); 2460 2461 po = pm->pm_owner; 2462 2463 /* 2464 * Disallow PMCSTART if a logfile is required but has not been 2465 * configured yet. 2466 */ 2467 if ((pm->pm_flags & PMC_F_NEEDS_LOGFILE) && 2468 (po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) 2469 return (EDOOFUS); /* programming error */ 2470 2471 /* 2472 * If this is a sampling mode PMC, log mapping information for 2473 * the kernel modules that are currently loaded. 2474 */ 2475 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 2476 pmc_log_kernel_mappings(pm); 2477 2478 if (PMC_IS_VIRTUAL_MODE(mode)) { 2479 2480 /* 2481 * If a PMCATTACH has never been done on this PMC, 2482 * attach it to its owner process. 2483 */ 2484 2485 if (LIST_EMPTY(&pm->pm_targets)) 2486 error = (pm->pm_flags & PMC_F_ATTACH_DONE) ? ESRCH : 2487 pmc_attach_process(po->po_owner, pm); 2488 2489 /* 2490 * If the PMC is attached to its owner, then force a context 2491 * switch to ensure that the MD state gets set correctly. 2492 */ 2493 2494 if (error == 0) { 2495 pm->pm_state = PMC_STATE_RUNNING; 2496 if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) 2497 pmc_force_context_switch(); 2498 } 2499 2500 return (error); 2501 } 2502 2503 2504 /* 2505 * A system-wide PMC. 2506 * 2507 * Add the owner to the global list if this is a system-wide 2508 * sampling PMC. 2509 */ 2510 2511 if (mode == PMC_MODE_SS) { 2512 if (po->po_sscount == 0) { 2513 LIST_INSERT_HEAD(&pmc_ss_owners, po, po_ssnext); 2514 atomic_add_rel_int(&pmc_ss_count, 1); 2515 PMCDBG(PMC,OPS,1, "po=%p in global list", po); 2516 } 2517 po->po_sscount++; 2518 } 2519 2520 /* Log mapping information for all processes in the system. */ 2521 pmc_log_all_process_mappings(po); 2522 2523 /* 2524 * Move to the CPU associated with this 2525 * PMC, and start the hardware. 2526 */ 2527 2528 pmc_save_cpu_binding(&pb); 2529 2530 cpu = PMC_TO_CPU(pm); 2531 2532 if (!pmc_cpu_is_active(cpu)) 2533 return (ENXIO); 2534 2535 pmc_select_cpu(cpu); 2536 2537 /* 2538 * global PMCs are configured at allocation time 2539 * so write out the initial value and start the PMC. 2540 */ 2541 2542 pm->pm_state = PMC_STATE_RUNNING; 2543 2544 critical_enter(); 2545 if ((error = pcd->pcd_write_pmc(cpu, adjri, 2546 PMC_IS_SAMPLING_MODE(mode) ? 2547 pm->pm_sc.pm_reloadcount : 2548 pm->pm_sc.pm_initial)) == 0) 2549 error = pcd->pcd_start_pmc(cpu, adjri); 2550 critical_exit(); 2551 2552 pmc_restore_cpu_binding(&pb); 2553 2554 return (error); 2555} 2556 2557/* 2558 * Stop a PMC. 2559 */ 2560 2561static int 2562pmc_stop(struct pmc *pm) 2563{ 2564 struct pmc_owner *po; 2565 struct pmc_binding pb; 2566 struct pmc_classdep *pcd; 2567 int adjri, cpu, error, ri; 2568 2569 KASSERT(pm != NULL, ("[pmc,%d] null pmc", __LINE__)); 2570 2571 PMCDBG(PMC,OPS,1, "stop pmc=%p mode=%d ri=%d", pm, 2572 PMC_TO_MODE(pm), PMC_TO_ROWINDEX(pm)); 2573 2574 pm->pm_state = PMC_STATE_STOPPED; 2575 2576 /* 2577 * If the PMC is a virtual mode one, changing the state to 2578 * non-RUNNING is enough to ensure that the PMC never gets 2579 * scheduled. 2580 * 2581 * If this PMC is current running on a CPU, then it will 2582 * handled correctly at the time its target process is context 2583 * switched out. 2584 */ 2585 2586 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) 2587 return 0; 2588 2589 /* 2590 * A system-mode PMC. Move to the CPU associated with 2591 * this PMC, and stop the hardware. We update the 2592 * 'initial count' so that a subsequent PMCSTART will 2593 * resume counting from the current hardware count. 2594 */ 2595 2596 pmc_save_cpu_binding(&pb); 2597 2598 cpu = PMC_TO_CPU(pm); 2599 2600 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 2601 ("[pmc,%d] illegal cpu=%d", __LINE__, cpu)); 2602 2603 if (!pmc_cpu_is_active(cpu)) 2604 return ENXIO; 2605 2606 pmc_select_cpu(cpu); 2607 2608 ri = PMC_TO_ROWINDEX(pm); 2609 pcd = pmc_ri_to_classdep(md, ri, &adjri); 2610 2611 critical_enter(); 2612 if ((error = pcd->pcd_stop_pmc(cpu, adjri)) == 0) 2613 error = pcd->pcd_read_pmc(cpu, adjri, &pm->pm_sc.pm_initial); 2614 critical_exit(); 2615 2616 pmc_restore_cpu_binding(&pb); 2617 2618 po = pm->pm_owner; 2619 2620 /* remove this owner from the global list of SS PMC owners */ 2621 if (PMC_TO_MODE(pm) == PMC_MODE_SS) { 2622 po->po_sscount--; 2623 if (po->po_sscount == 0) { 2624 atomic_subtract_rel_int(&pmc_ss_count, 1); 2625 LIST_REMOVE(po, po_ssnext); 2626 PMCDBG(PMC,OPS,2,"po=%p removed from global list", po); 2627 } 2628 } 2629 2630 return (error); 2631} 2632 2633 2634#ifdef DEBUG 2635static const char *pmc_op_to_name[] = { 2636#undef __PMC_OP 2637#define __PMC_OP(N, D) #N , 2638 __PMC_OPS() 2639 NULL 2640}; 2641#endif 2642 2643/* 2644 * The syscall interface 2645 */ 2646 2647#define PMC_GET_SX_XLOCK(...) do { \ 2648 sx_xlock(&pmc_sx); \ 2649 if (pmc_hook == NULL) { \ 2650 sx_xunlock(&pmc_sx); \ 2651 return __VA_ARGS__; \ 2652 } \ 2653} while (0) 2654 2655#define PMC_DOWNGRADE_SX() do { \ 2656 sx_downgrade(&pmc_sx); \ 2657 is_sx_downgraded = 1; \ 2658} while (0) 2659 2660static int 2661pmc_syscall_handler(struct thread *td, void *syscall_args) 2662{ 2663 int error, is_sx_downgraded, op; 2664 struct pmc_syscall_args *c; 2665 void *arg; 2666 2667 PMC_GET_SX_XLOCK(ENOSYS); 2668 2669 DROP_GIANT(); 2670 2671 is_sx_downgraded = 0; 2672 2673 c = (struct pmc_syscall_args *) syscall_args; 2674 2675 op = c->pmop_code; 2676 arg = c->pmop_data; 2677 2678 PMCDBG(MOD,PMS,1, "syscall op=%d \"%s\" arg=%p", op, 2679 pmc_op_to_name[op], arg); 2680 2681 error = 0; 2682 atomic_add_int(&pmc_stats.pm_syscalls, 1); 2683 2684 switch(op) 2685 { 2686 2687 2688 /* 2689 * Configure a log file. 2690 * 2691 * XXX This OP will be reworked. 2692 */ 2693 2694 case PMC_OP_CONFIGURELOG: 2695 { 2696 struct proc *p; 2697 struct pmc *pm; 2698 struct pmc_owner *po; 2699 struct pmc_op_configurelog cl; 2700 2701 sx_assert(&pmc_sx, SX_XLOCKED); 2702 2703 if ((error = copyin(arg, &cl, sizeof(cl))) != 0) 2704 break; 2705 2706 /* mark this process as owning a log file */ 2707 p = td->td_proc; 2708 if ((po = pmc_find_owner_descriptor(p)) == NULL) 2709 if ((po = pmc_allocate_owner_descriptor(p)) == NULL) { 2710 error = ENOMEM; 2711 break; 2712 } 2713 2714 /* 2715 * If a valid fd was passed in, try to configure that, 2716 * otherwise if 'fd' was less than zero and there was 2717 * a log file configured, flush its buffers and 2718 * de-configure it. 2719 */ 2720 if (cl.pm_logfd >= 0) 2721 error = pmclog_configure_log(md, po, cl.pm_logfd); 2722 else if (po->po_flags & PMC_PO_OWNS_LOGFILE) { 2723 pmclog_process_closelog(po); 2724 error = pmclog_flush(po); 2725 if (error == 0) { 2726 LIST_FOREACH(pm, &po->po_pmcs, pm_next) 2727 if (pm->pm_flags & PMC_F_NEEDS_LOGFILE && 2728 pm->pm_state == PMC_STATE_RUNNING) 2729 pmc_stop(pm); 2730 error = pmclog_deconfigure_log(po); 2731 } 2732 } else 2733 error = EINVAL; 2734 2735 if (error) 2736 break; 2737 } 2738 break; 2739 2740 2741 /* 2742 * Flush a log file. 2743 */ 2744 2745 case PMC_OP_FLUSHLOG: 2746 { 2747 struct pmc_owner *po; 2748 2749 sx_assert(&pmc_sx, SX_XLOCKED); 2750 2751 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 2752 error = EINVAL; 2753 break; 2754 } 2755 2756 error = pmclog_flush(po); 2757 } 2758 break; 2759 2760 /* 2761 * Retrieve hardware configuration. 2762 */ 2763 2764 case PMC_OP_GETCPUINFO: /* CPU information */ 2765 { 2766 struct pmc_op_getcpuinfo gci; 2767 struct pmc_classinfo *pci; 2768 struct pmc_classdep *pcd; 2769 int cl; 2770 2771 gci.pm_cputype = md->pmd_cputype; 2772 gci.pm_ncpu = pmc_cpu_max(); 2773 gci.pm_npmc = md->pmd_npmc; 2774 gci.pm_nclass = md->pmd_nclass; 2775 pci = gci.pm_classes; 2776 pcd = md->pmd_classdep; 2777 for (cl = 0; cl < md->pmd_nclass; cl++, pci++, pcd++) { 2778 pci->pm_caps = pcd->pcd_caps; 2779 pci->pm_class = pcd->pcd_class; 2780 pci->pm_width = pcd->pcd_width; 2781 pci->pm_num = pcd->pcd_num; 2782 } 2783 error = copyout(&gci, arg, sizeof(gci)); 2784 } 2785 break; 2786 2787 2788 /* 2789 * Get module statistics 2790 */ 2791 2792 case PMC_OP_GETDRIVERSTATS: 2793 { 2794 struct pmc_op_getdriverstats gms; 2795 2796 bcopy(&pmc_stats, &gms, sizeof(gms)); 2797 error = copyout(&gms, arg, sizeof(gms)); 2798 } 2799 break; 2800 2801 2802 /* 2803 * Retrieve module version number 2804 */ 2805 2806 case PMC_OP_GETMODULEVERSION: 2807 { 2808 uint32_t cv, modv; 2809 2810 /* retrieve the client's idea of the ABI version */ 2811 if ((error = copyin(arg, &cv, sizeof(uint32_t))) != 0) 2812 break; 2813 /* don't service clients newer than our driver */ 2814 modv = PMC_VERSION; 2815 if ((cv & 0xFFFF0000) > (modv & 0xFFFF0000)) { 2816 error = EPROGMISMATCH; 2817 break; 2818 } 2819 error = copyout(&modv, arg, sizeof(int)); 2820 } 2821 break; 2822 2823 2824 /* 2825 * Retrieve the state of all the PMCs on a given 2826 * CPU. 2827 */ 2828 2829 case PMC_OP_GETPMCINFO: 2830 { 2831 int ari; 2832 struct pmc *pm; 2833 size_t pmcinfo_size; 2834 uint32_t cpu, n, npmc; 2835 struct pmc_owner *po; 2836 struct pmc_binding pb; 2837 struct pmc_classdep *pcd; 2838 struct pmc_info *p, *pmcinfo; 2839 struct pmc_op_getpmcinfo *gpi; 2840 2841 PMC_DOWNGRADE_SX(); 2842 2843 gpi = (struct pmc_op_getpmcinfo *) arg; 2844 2845 if ((error = copyin(&gpi->pm_cpu, &cpu, sizeof(cpu))) != 0) 2846 break; 2847 2848 if (cpu >= pmc_cpu_max()) { 2849 error = EINVAL; 2850 break; 2851 } 2852 2853 if (!pmc_cpu_is_active(cpu)) { 2854 error = ENXIO; 2855 break; 2856 } 2857 2858 /* switch to CPU 'cpu' */ 2859 pmc_save_cpu_binding(&pb); 2860 pmc_select_cpu(cpu); 2861 2862 npmc = md->pmd_npmc; 2863 2864 pmcinfo_size = npmc * sizeof(struct pmc_info); 2865 pmcinfo = malloc(pmcinfo_size, M_PMC, M_WAITOK); 2866 2867 p = pmcinfo; 2868 2869 for (n = 0; n < md->pmd_npmc; n++, p++) { 2870 2871 pcd = pmc_ri_to_classdep(md, n, &ari); 2872 2873 KASSERT(pcd != NULL, 2874 ("[pmc,%d] null pcd ri=%d", __LINE__, n)); 2875 2876 if ((error = pcd->pcd_describe(cpu, ari, p, &pm)) != 0) 2877 break; 2878 2879 if (PMC_ROW_DISP_IS_STANDALONE(n)) 2880 p->pm_rowdisp = PMC_DISP_STANDALONE; 2881 else if (PMC_ROW_DISP_IS_THREAD(n)) 2882 p->pm_rowdisp = PMC_DISP_THREAD; 2883 else 2884 p->pm_rowdisp = PMC_DISP_FREE; 2885 2886 p->pm_ownerpid = -1; 2887 2888 if (pm == NULL) /* no PMC associated */ 2889 continue; 2890 2891 po = pm->pm_owner; 2892 2893 KASSERT(po->po_owner != NULL, 2894 ("[pmc,%d] pmc_owner had a null proc pointer", 2895 __LINE__)); 2896 2897 p->pm_ownerpid = po->po_owner->p_pid; 2898 p->pm_mode = PMC_TO_MODE(pm); 2899 p->pm_event = pm->pm_event; 2900 p->pm_flags = pm->pm_flags; 2901 2902 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 2903 p->pm_reloadcount = 2904 pm->pm_sc.pm_reloadcount; 2905 } 2906 2907 pmc_restore_cpu_binding(&pb); 2908 2909 /* now copy out the PMC info collected */ 2910 if (error == 0) 2911 error = copyout(pmcinfo, &gpi->pm_pmcs, pmcinfo_size); 2912 2913 free(pmcinfo, M_PMC); 2914 } 2915 break; 2916 2917 2918 /* 2919 * Set the administrative state of a PMC. I.e. whether 2920 * the PMC is to be used or not. 2921 */ 2922 2923 case PMC_OP_PMCADMIN: 2924 { 2925 int cpu, ri; 2926 enum pmc_state request; 2927 struct pmc_cpu *pc; 2928 struct pmc_hw *phw; 2929 struct pmc_op_pmcadmin pma; 2930 struct pmc_binding pb; 2931 2932 sx_assert(&pmc_sx, SX_XLOCKED); 2933 2934 KASSERT(td == curthread, 2935 ("[pmc,%d] td != curthread", __LINE__)); 2936 2937 error = priv_check(td, PRIV_PMC_MANAGE); 2938 if (error) 2939 break; 2940 2941 if ((error = copyin(arg, &pma, sizeof(pma))) != 0) 2942 break; 2943 2944 cpu = pma.pm_cpu; 2945 2946 if (cpu < 0 || cpu >= (int) pmc_cpu_max()) { 2947 error = EINVAL; 2948 break; 2949 } 2950 2951 if (!pmc_cpu_is_active(cpu)) { 2952 error = ENXIO; 2953 break; 2954 } 2955 2956 request = pma.pm_state; 2957 2958 if (request != PMC_STATE_DISABLED && 2959 request != PMC_STATE_FREE) { 2960 error = EINVAL; 2961 break; 2962 } 2963 2964 ri = pma.pm_pmc; /* pmc id == row index */ 2965 if (ri < 0 || ri >= (int) md->pmd_npmc) { 2966 error = EINVAL; 2967 break; 2968 } 2969 2970 /* 2971 * We can't disable a PMC with a row-index allocated 2972 * for process virtual PMCs. 2973 */ 2974 2975 if (PMC_ROW_DISP_IS_THREAD(ri) && 2976 request == PMC_STATE_DISABLED) { 2977 error = EBUSY; 2978 break; 2979 } 2980 2981 /* 2982 * otherwise, this PMC on this CPU is either free or 2983 * in system-wide mode. 2984 */ 2985 2986 pmc_save_cpu_binding(&pb); 2987 pmc_select_cpu(cpu); 2988 2989 pc = pmc_pcpu[cpu]; 2990 phw = pc->pc_hwpmcs[ri]; 2991 2992 /* 2993 * XXX do we need some kind of 'forced' disable? 2994 */ 2995 2996 if (phw->phw_pmc == NULL) { 2997 if (request == PMC_STATE_DISABLED && 2998 (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED)) { 2999 phw->phw_state &= ~PMC_PHW_FLAG_IS_ENABLED; 3000 PMC_MARK_ROW_STANDALONE(ri); 3001 } else if (request == PMC_STATE_FREE && 3002 (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0) { 3003 phw->phw_state |= PMC_PHW_FLAG_IS_ENABLED; 3004 PMC_UNMARK_ROW_STANDALONE(ri); 3005 } 3006 /* other cases are a no-op */ 3007 } else 3008 error = EBUSY; 3009 3010 pmc_restore_cpu_binding(&pb); 3011 } 3012 break; 3013 3014 3015 /* 3016 * Allocate a PMC. 3017 */ 3018 3019 case PMC_OP_PMCALLOCATE: 3020 { 3021 int adjri, n; 3022 u_int cpu; 3023 uint32_t caps; 3024 struct pmc *pmc; 3025 enum pmc_mode mode; 3026 struct pmc_hw *phw; 3027 struct pmc_binding pb; 3028 struct pmc_classdep *pcd; 3029 struct pmc_op_pmcallocate pa; 3030 3031 if ((error = copyin(arg, &pa, sizeof(pa))) != 0) 3032 break; 3033 3034 caps = pa.pm_caps; 3035 mode = pa.pm_mode; 3036 cpu = pa.pm_cpu; 3037 3038 if ((mode != PMC_MODE_SS && mode != PMC_MODE_SC && 3039 mode != PMC_MODE_TS && mode != PMC_MODE_TC) || 3040 (cpu != (u_int) PMC_CPU_ANY && cpu >= pmc_cpu_max())) { 3041 error = EINVAL; 3042 break; 3043 } 3044 3045 /* 3046 * Virtual PMCs should only ask for a default CPU. 3047 * System mode PMCs need to specify a non-default CPU. 3048 */ 3049 3050 if ((PMC_IS_VIRTUAL_MODE(mode) && cpu != (u_int) PMC_CPU_ANY) || 3051 (PMC_IS_SYSTEM_MODE(mode) && cpu == (u_int) PMC_CPU_ANY)) { 3052 error = EINVAL; 3053 break; 3054 } 3055 3056 /* 3057 * Check that an inactive CPU is not being asked for. 3058 */ 3059 3060 if (PMC_IS_SYSTEM_MODE(mode) && !pmc_cpu_is_active(cpu)) { 3061 error = ENXIO; 3062 break; 3063 } 3064 3065 /* 3066 * Refuse an allocation for a system-wide PMC if this 3067 * process has been jailed, or if this process lacks 3068 * super-user credentials and the sysctl tunable 3069 * 'security.bsd.unprivileged_syspmcs' is zero. 3070 */ 3071 3072 if (PMC_IS_SYSTEM_MODE(mode)) { 3073 if (jailed(curthread->td_ucred)) { 3074 error = EPERM; 3075 break; 3076 } 3077 if (!pmc_unprivileged_syspmcs) { 3078 error = priv_check(curthread, 3079 PRIV_PMC_SYSTEM); 3080 if (error) 3081 break; 3082 } 3083 } 3084 3085 if (error) 3086 break; 3087 3088 /* 3089 * Look for valid values for 'pm_flags' 3090 */ 3091 3092 if ((pa.pm_flags & ~(PMC_F_DESCENDANTS | PMC_F_LOG_PROCCSW | 3093 PMC_F_LOG_PROCEXIT | PMC_F_CALLCHAIN)) != 0) { 3094 error = EINVAL; 3095 break; 3096 } 3097 3098 /* process logging options are not allowed for system PMCs */ 3099 if (PMC_IS_SYSTEM_MODE(mode) && (pa.pm_flags & 3100 (PMC_F_LOG_PROCCSW | PMC_F_LOG_PROCEXIT))) { 3101 error = EINVAL; 3102 break; 3103 } 3104 3105 /* 3106 * All sampling mode PMCs need to be able to interrupt the 3107 * CPU. 3108 */ 3109 if (PMC_IS_SAMPLING_MODE(mode)) 3110 caps |= PMC_CAP_INTERRUPT; 3111 3112 /* A valid class specifier should have been passed in. */ 3113 for (n = 0; n < md->pmd_nclass; n++) 3114 if (md->pmd_classdep[n].pcd_class == pa.pm_class) 3115 break; 3116 if (n == md->pmd_nclass) { 3117 error = EINVAL; 3118 break; 3119 } 3120 3121 /* The requested PMC capabilities should be feasible. */ 3122 if ((md->pmd_classdep[n].pcd_caps & caps) != caps) { 3123 error = EOPNOTSUPP; 3124 break; 3125 } 3126 3127 PMCDBG(PMC,ALL,2, "event=%d caps=0x%x mode=%d cpu=%d", 3128 pa.pm_ev, caps, mode, cpu); 3129 3130 pmc = pmc_allocate_pmc_descriptor(); 3131 pmc->pm_id = PMC_ID_MAKE_ID(cpu,pa.pm_mode,pa.pm_class, 3132 PMC_ID_INVALID); 3133 pmc->pm_event = pa.pm_ev; 3134 pmc->pm_state = PMC_STATE_FREE; 3135 pmc->pm_caps = caps; 3136 pmc->pm_flags = pa.pm_flags; 3137 3138 /* switch thread to CPU 'cpu' */ 3139 pmc_save_cpu_binding(&pb); 3140 3141#define PMC_IS_SHAREABLE_PMC(cpu, n) \ 3142 (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_state & \ 3143 PMC_PHW_FLAG_IS_SHAREABLE) 3144#define PMC_IS_UNALLOCATED(cpu, n) \ 3145 (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_pmc == NULL) 3146 3147 if (PMC_IS_SYSTEM_MODE(mode)) { 3148 pmc_select_cpu(cpu); 3149 for (n = 0; n < (int) md->pmd_npmc; n++) { 3150 pcd = pmc_ri_to_classdep(md, n, &adjri); 3151 if (pmc_can_allocate_row(n, mode) == 0 && 3152 pmc_can_allocate_rowindex( 3153 curthread->td_proc, n, cpu) == 0 && 3154 (PMC_IS_UNALLOCATED(cpu, n) || 3155 PMC_IS_SHAREABLE_PMC(cpu, n)) && 3156 pcd->pcd_allocate_pmc(cpu, adjri, pmc, 3157 &pa) == 0) 3158 break; 3159 } 3160 } else { 3161 /* Process virtual mode */ 3162 for (n = 0; n < (int) md->pmd_npmc; n++) { 3163 pcd = pmc_ri_to_classdep(md, n, &adjri); 3164 if (pmc_can_allocate_row(n, mode) == 0 && 3165 pmc_can_allocate_rowindex( 3166 curthread->td_proc, n, 3167 PMC_CPU_ANY) == 0 && 3168 pcd->pcd_allocate_pmc(curthread->td_oncpu, 3169 adjri, pmc, &pa) == 0) 3170 break; 3171 } 3172 } 3173 3174#undef PMC_IS_UNALLOCATED 3175#undef PMC_IS_SHAREABLE_PMC 3176 3177 pmc_restore_cpu_binding(&pb); 3178 3179 if (n == (int) md->pmd_npmc) { 3180 pmc_destroy_pmc_descriptor(pmc); 3181 free(pmc, M_PMC); 3182 pmc = NULL; 3183 error = EINVAL; 3184 break; 3185 } 3186 3187 /* Fill in the correct value in the ID field */ 3188 pmc->pm_id = PMC_ID_MAKE_ID(cpu,mode,pa.pm_class,n); 3189 3190 PMCDBG(PMC,ALL,2, "ev=%d class=%d mode=%d n=%d -> pmcid=%x", 3191 pmc->pm_event, pa.pm_class, mode, n, pmc->pm_id); 3192 3193 /* Process mode PMCs with logging enabled need log files */ 3194 if (pmc->pm_flags & (PMC_F_LOG_PROCEXIT | PMC_F_LOG_PROCCSW)) 3195 pmc->pm_flags |= PMC_F_NEEDS_LOGFILE; 3196 3197 /* All system mode sampling PMCs require a log file */ 3198 if (PMC_IS_SAMPLING_MODE(mode) && PMC_IS_SYSTEM_MODE(mode)) 3199 pmc->pm_flags |= PMC_F_NEEDS_LOGFILE; 3200 3201 /* 3202 * Configure global pmc's immediately 3203 */ 3204 3205 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pmc))) { 3206 3207 pmc_save_cpu_binding(&pb); 3208 pmc_select_cpu(cpu); 3209 3210 phw = pmc_pcpu[cpu]->pc_hwpmcs[n]; 3211 pcd = pmc_ri_to_classdep(md, n, &adjri); 3212 3213 if ((phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0 || 3214 (error = pcd->pcd_config_pmc(cpu, adjri, pmc)) != 0) { 3215 (void) pcd->pcd_release_pmc(cpu, adjri, pmc); 3216 pmc_destroy_pmc_descriptor(pmc); 3217 free(pmc, M_PMC); 3218 pmc = NULL; 3219 pmc_restore_cpu_binding(&pb); 3220 error = EPERM; 3221 break; 3222 } 3223 3224 pmc_restore_cpu_binding(&pb); 3225 } 3226 3227 pmc->pm_state = PMC_STATE_ALLOCATED; 3228 3229 /* 3230 * mark row disposition 3231 */ 3232 3233 if (PMC_IS_SYSTEM_MODE(mode)) 3234 PMC_MARK_ROW_STANDALONE(n); 3235 else 3236 PMC_MARK_ROW_THREAD(n); 3237 3238 /* 3239 * Register this PMC with the current thread as its owner. 3240 */ 3241 3242 if ((error = 3243 pmc_register_owner(curthread->td_proc, pmc)) != 0) { 3244 pmc_release_pmc_descriptor(pmc); 3245 free(pmc, M_PMC); 3246 pmc = NULL; 3247 break; 3248 } 3249 3250 /* 3251 * Return the allocated index. 3252 */ 3253 3254 pa.pm_pmcid = pmc->pm_id; 3255 3256 error = copyout(&pa, arg, sizeof(pa)); 3257 } 3258 break; 3259 3260 3261 /* 3262 * Attach a PMC to a process. 3263 */ 3264 3265 case PMC_OP_PMCATTACH: 3266 { 3267 struct pmc *pm; 3268 struct proc *p; 3269 struct pmc_op_pmcattach a; 3270 3271 sx_assert(&pmc_sx, SX_XLOCKED); 3272 3273 if ((error = copyin(arg, &a, sizeof(a))) != 0) 3274 break; 3275 3276 if (a.pm_pid < 0) { 3277 error = EINVAL; 3278 break; 3279 } else if (a.pm_pid == 0) 3280 a.pm_pid = td->td_proc->p_pid; 3281 3282 if ((error = pmc_find_pmc(a.pm_pmc, &pm)) != 0) 3283 break; 3284 3285 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) { 3286 error = EINVAL; 3287 break; 3288 } 3289 3290 /* PMCs may be (re)attached only when allocated or stopped */ 3291 if (pm->pm_state == PMC_STATE_RUNNING) { 3292 error = EBUSY; 3293 break; 3294 } else if (pm->pm_state != PMC_STATE_ALLOCATED && 3295 pm->pm_state != PMC_STATE_STOPPED) { 3296 error = EINVAL; 3297 break; 3298 } 3299 3300 /* lookup pid */ 3301 if ((p = pfind(a.pm_pid)) == NULL) { 3302 error = ESRCH; 3303 break; 3304 } 3305 3306 /* 3307 * Ignore processes that are working on exiting. 3308 */ 3309 if (p->p_flag & P_WEXIT) { 3310 error = ESRCH; 3311 PROC_UNLOCK(p); /* pfind() returns a locked process */ 3312 break; 3313 } 3314 3315 /* 3316 * we are allowed to attach a PMC to a process if 3317 * we can debug it. 3318 */ 3319 error = p_candebug(curthread, p); 3320 3321 PROC_UNLOCK(p); 3322 3323 if (error == 0) 3324 error = pmc_attach_process(p, pm); 3325 } 3326 break; 3327 3328 3329 /* 3330 * Detach an attached PMC from a process. 3331 */ 3332 3333 case PMC_OP_PMCDETACH: 3334 { 3335 struct pmc *pm; 3336 struct proc *p; 3337 struct pmc_op_pmcattach a; 3338 3339 if ((error = copyin(arg, &a, sizeof(a))) != 0) 3340 break; 3341 3342 if (a.pm_pid < 0) { 3343 error = EINVAL; 3344 break; 3345 } else if (a.pm_pid == 0) 3346 a.pm_pid = td->td_proc->p_pid; 3347 3348 if ((error = pmc_find_pmc(a.pm_pmc, &pm)) != 0) 3349 break; 3350 3351 if ((p = pfind(a.pm_pid)) == NULL) { 3352 error = ESRCH; 3353 break; 3354 } 3355 3356 /* 3357 * Treat processes that are in the process of exiting 3358 * as if they were not present. 3359 */ 3360 3361 if (p->p_flag & P_WEXIT) 3362 error = ESRCH; 3363 3364 PROC_UNLOCK(p); /* pfind() returns a locked process */ 3365 3366 if (error == 0) 3367 error = pmc_detach_process(p, pm); 3368 } 3369 break; 3370 3371 3372 /* 3373 * Retrieve the MSR number associated with the counter 3374 * 'pmc_id'. This allows processes to directly use RDPMC 3375 * instructions to read their PMCs, without the overhead of a 3376 * system call. 3377 */ 3378 3379 case PMC_OP_PMCGETMSR: 3380 { 3381 int adjri, ri; 3382 struct pmc *pm; 3383 struct pmc_target *pt; 3384 struct pmc_op_getmsr gm; 3385 struct pmc_classdep *pcd; 3386 3387 PMC_DOWNGRADE_SX(); 3388 3389 if ((error = copyin(arg, &gm, sizeof(gm))) != 0) 3390 break; 3391 3392 if ((error = pmc_find_pmc(gm.pm_pmcid, &pm)) != 0) 3393 break; 3394 3395 /* 3396 * The allocated PMC has to be a process virtual PMC, 3397 * i.e., of type MODE_T[CS]. Global PMCs can only be 3398 * read using the PMCREAD operation since they may be 3399 * allocated on a different CPU than the one we could 3400 * be running on at the time of the RDPMC instruction. 3401 * 3402 * The GETMSR operation is not allowed for PMCs that 3403 * are inherited across processes. 3404 */ 3405 3406 if (!PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)) || 3407 (pm->pm_flags & PMC_F_DESCENDANTS)) { 3408 error = EINVAL; 3409 break; 3410 } 3411 3412 /* 3413 * It only makes sense to use a RDPMC (or its 3414 * equivalent instruction on non-x86 architectures) on 3415 * a process that has allocated and attached a PMC to 3416 * itself. Conversely the PMC is only allowed to have 3417 * one process attached to it -- its owner. 3418 */ 3419 3420 if ((pt = LIST_FIRST(&pm->pm_targets)) == NULL || 3421 LIST_NEXT(pt, pt_next) != NULL || 3422 pt->pt_process->pp_proc != pm->pm_owner->po_owner) { 3423 error = EINVAL; 3424 break; 3425 } 3426 3427 ri = PMC_TO_ROWINDEX(pm); 3428 pcd = pmc_ri_to_classdep(md, ri, &adjri); 3429 3430 /* PMC class has no 'GETMSR' support */ 3431 if (pcd->pcd_get_msr == NULL) { 3432 error = ENOSYS; 3433 break; 3434 } 3435 3436 if ((error = (*pcd->pcd_get_msr)(adjri, &gm.pm_msr)) < 0) 3437 break; 3438 3439 if ((error = copyout(&gm, arg, sizeof(gm))) < 0) 3440 break; 3441 3442 /* 3443 * Mark our process as using MSRs. Update machine 3444 * state using a forced context switch. 3445 */ 3446 3447 pt->pt_process->pp_flags |= PMC_PP_ENABLE_MSR_ACCESS; 3448 pmc_force_context_switch(); 3449 3450 } 3451 break; 3452 3453 /* 3454 * Release an allocated PMC 3455 */ 3456 3457 case PMC_OP_PMCRELEASE: 3458 { 3459 pmc_id_t pmcid; 3460 struct pmc *pm; 3461 struct pmc_owner *po; 3462 struct pmc_op_simple sp; 3463 3464 /* 3465 * Find PMC pointer for the named PMC. 3466 * 3467 * Use pmc_release_pmc_descriptor() to switch off the 3468 * PMC, remove all its target threads, and remove the 3469 * PMC from its owner's list. 3470 * 3471 * Remove the owner record if this is the last PMC 3472 * owned. 3473 * 3474 * Free up space. 3475 */ 3476 3477 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 3478 break; 3479 3480 pmcid = sp.pm_pmcid; 3481 3482 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 3483 break; 3484 3485 po = pm->pm_owner; 3486 pmc_release_pmc_descriptor(pm); 3487 pmc_maybe_remove_owner(po); 3488 3489 free(pm, M_PMC); 3490 } 3491 break; 3492 3493 3494 /* 3495 * Read and/or write a PMC. 3496 */ 3497 3498 case PMC_OP_PMCRW: 3499 { 3500 int adjri; 3501 struct pmc *pm; 3502 uint32_t cpu, ri; 3503 pmc_value_t oldvalue; 3504 struct pmc_binding pb; 3505 struct pmc_op_pmcrw prw; 3506 struct pmc_classdep *pcd; 3507 struct pmc_op_pmcrw *pprw; 3508 3509 PMC_DOWNGRADE_SX(); 3510 3511 if ((error = copyin(arg, &prw, sizeof(prw))) != 0) 3512 break; 3513 3514 ri = 0; 3515 PMCDBG(PMC,OPS,1, "rw id=%d flags=0x%x", prw.pm_pmcid, 3516 prw.pm_flags); 3517 3518 /* must have at least one flag set */ 3519 if ((prw.pm_flags & (PMC_F_OLDVALUE|PMC_F_NEWVALUE)) == 0) { 3520 error = EINVAL; 3521 break; 3522 } 3523 3524 /* locate pmc descriptor */ 3525 if ((error = pmc_find_pmc(prw.pm_pmcid, &pm)) != 0) 3526 break; 3527 3528 /* Can't read a PMC that hasn't been started. */ 3529 if (pm->pm_state != PMC_STATE_ALLOCATED && 3530 pm->pm_state != PMC_STATE_STOPPED && 3531 pm->pm_state != PMC_STATE_RUNNING) { 3532 error = EINVAL; 3533 break; 3534 } 3535 3536 /* writing a new value is allowed only for 'STOPPED' pmcs */ 3537 if (pm->pm_state == PMC_STATE_RUNNING && 3538 (prw.pm_flags & PMC_F_NEWVALUE)) { 3539 error = EBUSY; 3540 break; 3541 } 3542 3543 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) { 3544 3545 /* 3546 * If this PMC is attached to its owner (i.e., 3547 * the process requesting this operation) and 3548 * is running, then attempt to get an 3549 * upto-date reading from hardware for a READ. 3550 * Writes are only allowed when the PMC is 3551 * stopped, so only update the saved value 3552 * field. 3553 * 3554 * If the PMC is not running, or is not 3555 * attached to its owner, read/write to the 3556 * savedvalue field. 3557 */ 3558 3559 ri = PMC_TO_ROWINDEX(pm); 3560 pcd = pmc_ri_to_classdep(md, ri, &adjri); 3561 3562 mtx_pool_lock_spin(pmc_mtxpool, pm); 3563 cpu = curthread->td_oncpu; 3564 3565 if (prw.pm_flags & PMC_F_OLDVALUE) { 3566 if ((pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) && 3567 (pm->pm_state == PMC_STATE_RUNNING)) 3568 error = (*pcd->pcd_read_pmc)(cpu, adjri, 3569 &oldvalue); 3570 else 3571 oldvalue = pm->pm_gv.pm_savedvalue; 3572 } 3573 if (prw.pm_flags & PMC_F_NEWVALUE) 3574 pm->pm_gv.pm_savedvalue = prw.pm_value; 3575 3576 mtx_pool_unlock_spin(pmc_mtxpool, pm); 3577 3578 } else { /* System mode PMCs */ 3579 cpu = PMC_TO_CPU(pm); 3580 ri = PMC_TO_ROWINDEX(pm); 3581 pcd = pmc_ri_to_classdep(md, ri, &adjri); 3582 3583 if (!pmc_cpu_is_active(cpu)) { 3584 error = ENXIO; 3585 break; 3586 } 3587 3588 /* move this thread to CPU 'cpu' */ 3589 pmc_save_cpu_binding(&pb); 3590 pmc_select_cpu(cpu); 3591 3592 critical_enter(); 3593 /* save old value */ 3594 if (prw.pm_flags & PMC_F_OLDVALUE) 3595 if ((error = (*pcd->pcd_read_pmc)(cpu, adjri, 3596 &oldvalue))) 3597 goto error; 3598 /* write out new value */ 3599 if (prw.pm_flags & PMC_F_NEWVALUE) 3600 error = (*pcd->pcd_write_pmc)(cpu, adjri, 3601 prw.pm_value); 3602 error: 3603 critical_exit(); 3604 pmc_restore_cpu_binding(&pb); 3605 if (error) 3606 break; 3607 } 3608 3609 pprw = (struct pmc_op_pmcrw *) arg; 3610 3611#ifdef DEBUG 3612 if (prw.pm_flags & PMC_F_NEWVALUE) 3613 PMCDBG(PMC,OPS,2, "rw id=%d new %jx -> old %jx", 3614 ri, prw.pm_value, oldvalue); 3615 else if (prw.pm_flags & PMC_F_OLDVALUE) 3616 PMCDBG(PMC,OPS,2, "rw id=%d -> old %jx", ri, oldvalue); 3617#endif 3618 3619 /* return old value if requested */ 3620 if (prw.pm_flags & PMC_F_OLDVALUE) 3621 if ((error = copyout(&oldvalue, &pprw->pm_value, 3622 sizeof(prw.pm_value)))) 3623 break; 3624 3625 } 3626 break; 3627 3628 3629 /* 3630 * Set the sampling rate for a sampling mode PMC and the 3631 * initial count for a counting mode PMC. 3632 */ 3633 3634 case PMC_OP_PMCSETCOUNT: 3635 { 3636 struct pmc *pm; 3637 struct pmc_op_pmcsetcount sc; 3638 3639 PMC_DOWNGRADE_SX(); 3640 3641 if ((error = copyin(arg, &sc, sizeof(sc))) != 0) 3642 break; 3643 3644 if ((error = pmc_find_pmc(sc.pm_pmcid, &pm)) != 0) 3645 break; 3646 3647 if (pm->pm_state == PMC_STATE_RUNNING) { 3648 error = EBUSY; 3649 break; 3650 } 3651 3652 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 3653 pm->pm_sc.pm_reloadcount = sc.pm_count; 3654 else 3655 pm->pm_sc.pm_initial = sc.pm_count; 3656 } 3657 break; 3658 3659 3660 /* 3661 * Start a PMC. 3662 */ 3663 3664 case PMC_OP_PMCSTART: 3665 { 3666 pmc_id_t pmcid; 3667 struct pmc *pm; 3668 struct pmc_op_simple sp; 3669 3670 sx_assert(&pmc_sx, SX_XLOCKED); 3671 3672 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 3673 break; 3674 3675 pmcid = sp.pm_pmcid; 3676 3677 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 3678 break; 3679 3680 KASSERT(pmcid == pm->pm_id, 3681 ("[pmc,%d] pmcid %x != id %x", __LINE__, 3682 pm->pm_id, pmcid)); 3683 3684 if (pm->pm_state == PMC_STATE_RUNNING) /* already running */ 3685 break; 3686 else if (pm->pm_state != PMC_STATE_STOPPED && 3687 pm->pm_state != PMC_STATE_ALLOCATED) { 3688 error = EINVAL; 3689 break; 3690 } 3691 3692 error = pmc_start(pm); 3693 } 3694 break; 3695 3696 3697 /* 3698 * Stop a PMC. 3699 */ 3700 3701 case PMC_OP_PMCSTOP: 3702 { 3703 pmc_id_t pmcid; 3704 struct pmc *pm; 3705 struct pmc_op_simple sp; 3706 3707 PMC_DOWNGRADE_SX(); 3708 3709 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 3710 break; 3711 3712 pmcid = sp.pm_pmcid; 3713 3714 /* 3715 * Mark the PMC as inactive and invoke the MD stop 3716 * routines if needed. 3717 */ 3718 3719 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 3720 break; 3721 3722 KASSERT(pmcid == pm->pm_id, 3723 ("[pmc,%d] pmc id %x != pmcid %x", __LINE__, 3724 pm->pm_id, pmcid)); 3725 3726 if (pm->pm_state == PMC_STATE_STOPPED) /* already stopped */ 3727 break; 3728 else if (pm->pm_state != PMC_STATE_RUNNING) { 3729 error = EINVAL; 3730 break; 3731 } 3732 3733 error = pmc_stop(pm); 3734 } 3735 break; 3736 3737 3738 /* 3739 * Write a user supplied value to the log file. 3740 */ 3741 3742 case PMC_OP_WRITELOG: 3743 { 3744 struct pmc_op_writelog wl; 3745 struct pmc_owner *po; 3746 3747 PMC_DOWNGRADE_SX(); 3748 3749 if ((error = copyin(arg, &wl, sizeof(wl))) != 0) 3750 break; 3751 3752 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 3753 error = EINVAL; 3754 break; 3755 } 3756 3757 if ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) { 3758 error = EINVAL; 3759 break; 3760 } 3761 3762 error = pmclog_process_userlog(po, &wl); 3763 } 3764 break; 3765 3766 3767 default: 3768 error = EINVAL; 3769 break; 3770 } 3771 3772 if (is_sx_downgraded) 3773 sx_sunlock(&pmc_sx); 3774 else 3775 sx_xunlock(&pmc_sx); 3776 3777 if (error) 3778 atomic_add_int(&pmc_stats.pm_syscall_errors, 1); 3779 3780 PICKUP_GIANT(); 3781 3782 return error; 3783} 3784 3785/* 3786 * Helper functions 3787 */ 3788 3789 3790/* 3791 * Mark the thread as needing callchain capture and post an AST. The 3792 * actual callchain capture will be done in a context where it is safe 3793 * to take page faults. 3794 */ 3795 3796static void 3797pmc_post_callchain_ast(void) 3798{ 3799 struct thread *td; 3800 3801 td = curthread; 3802 3803 /* 3804 * Mark this thread as needing processing in ast(). 3805 * td->td_pflags will be safe to touch as the process was in 3806 * user space when it was interrupted. 3807 */ 3808 td->td_pflags |= TDP_CALLCHAIN; 3809 3810 /* 3811 * Again, since we've entered this function directly from 3812 * userland, `td' is guaranteed to be not locked by this CPU, 3813 * so its safe to try acquire the thread lock even though we 3814 * are executing in an NMI context. We need to acquire this 3815 * lock before touching `td_flags' because other CPUs may be 3816 * in the process of touching this field. 3817 */ 3818 thread_lock(td); 3819 td->td_flags |= TDF_ASTPENDING; 3820 thread_unlock(td); 3821 3822 return; 3823} 3824 3825/* 3826 * Interrupt processing. 3827 * 3828 * Find a free slot in the per-cpu array of samples and capture the 3829 * current callchain there. If a sample was successfully added, a bit 3830 * is set in mask 'pmc_cpumask' denoting that the DO_SAMPLES hook 3831 * needs to be invoked from the clock handler. 3832 * 3833 * This function is meant to be called from an NMI handler. It cannot 3834 * use any of the locking primitives supplied by the OS. 3835 */ 3836 3837int 3838pmc_process_interrupt(int cpu, struct pmc *pm, struct trapframe *tf, 3839 int inuserspace) 3840{ 3841 int error, callchaindepth; 3842 struct thread *td; 3843 struct pmc_sample *ps; 3844 struct pmc_samplebuffer *psb; 3845 3846 error = 0; 3847 3848 /* 3849 * Allocate space for a sample buffer. 3850 */ 3851 psb = pmc_pcpu[cpu]->pc_sb; 3852 3853 ps = psb->ps_write; 3854 if (ps->ps_nsamples) { /* in use, reader hasn't caught up */ 3855 pm->pm_stalled = 1; 3856 atomic_add_int(&pmc_stats.pm_intr_bufferfull, 1); 3857 PMCDBG(SAM,INT,1,"(spc) cpu=%d pm=%p tf=%p um=%d wr=%d rd=%d", 3858 cpu, pm, (void *) tf, inuserspace, 3859 (int) (psb->ps_write - psb->ps_samples), 3860 (int) (psb->ps_read - psb->ps_samples)); 3861 error = ENOMEM; 3862 goto done; 3863 } 3864 3865 3866 /* Fill in entry. */ 3867 PMCDBG(SAM,INT,1,"cpu=%d pm=%p tf=%p um=%d wr=%d rd=%d", cpu, pm, 3868 (void *) tf, inuserspace, 3869 (int) (psb->ps_write - psb->ps_samples), 3870 (int) (psb->ps_read - psb->ps_samples)); 3871 3872 atomic_add_rel_32(&pm->pm_runcount, 1); /* hold onto PMC */ 3873 ps->ps_pmc = pm; 3874 if ((td = curthread) && td->td_proc) 3875 ps->ps_pid = td->td_proc->p_pid; 3876 else 3877 ps->ps_pid = -1; 3878 ps->ps_cpu = cpu; 3879 ps->ps_flags = inuserspace ? PMC_CC_F_USERSPACE : 0; 3880 3881 callchaindepth = (pm->pm_flags & PMC_F_CALLCHAIN) ? 3882 pmc_callchaindepth : 1; 3883 3884 if (callchaindepth == 1) 3885 ps->ps_pc[0] = PMC_TRAPFRAME_TO_PC(tf); 3886 else { 3887 /* 3888 * Kernel stack traversals can be done immediately, 3889 * while we defer to an AST for user space traversals. 3890 */ 3891 if (!inuserspace) 3892 callchaindepth = 3893 pmc_save_kernel_callchain(ps->ps_pc, 3894 callchaindepth, tf); 3895 else { 3896 pmc_post_callchain_ast(); 3897 callchaindepth = PMC_SAMPLE_INUSE; 3898 } 3899 } 3900 3901 ps->ps_nsamples = callchaindepth; /* mark entry as in use */ 3902 3903 /* increment write pointer, modulo ring buffer size */ 3904 ps++; 3905 if (ps == psb->ps_fence) 3906 psb->ps_write = psb->ps_samples; 3907 else 3908 psb->ps_write = ps; 3909 3910 done: 3911 /* mark CPU as needing processing */ 3912 atomic_set_rel_int(&pmc_cpumask, (1 << cpu)); 3913 3914 return (error); 3915} 3916 3917/* 3918 * Capture a user call chain. This function will be called from ast() 3919 * before control returns to userland and before the process gets 3920 * rescheduled. 3921 */ 3922 3923static void 3924pmc_capture_user_callchain(int cpu, struct trapframe *tf) 3925{ 3926 int i; 3927 struct pmc *pm; 3928 struct pmc_sample *ps; 3929 struct pmc_samplebuffer *psb; 3930 3931 psb = pmc_pcpu[cpu]->pc_sb; 3932 3933 /* 3934 * Iterate through all deferred callchain requests. 3935 */ 3936 3937 for (i = 0; i < pmc_nsamples; i++) { 3938 3939 ps = &psb->ps_samples[i]; 3940 if (ps->ps_nsamples != PMC_SAMPLE_INUSE) 3941 continue; 3942 3943 pm = ps->ps_pmc; 3944 3945 KASSERT(pm->pm_flags & PMC_F_CALLCHAIN, 3946 ("[pmc,%d] Retrieving callchain for PMC that doesn't " 3947 "want it", __LINE__)); 3948 3949 /* 3950 * Retrieve the callchain and mark the sample buffer 3951 * as 'processable' by the timer tick sweep code. 3952 */ 3953 ps->ps_nsamples = pmc_save_user_callchain(ps->ps_pc, 3954 pmc_callchaindepth, tf); 3955 } 3956 3957 return; 3958} 3959 3960 3961/* 3962 * Process saved PC samples. 3963 */ 3964 3965static void 3966pmc_process_samples(int cpu) 3967{ 3968 struct pmc *pm; 3969 int adjri, n; 3970 struct thread *td; 3971 struct pmc_owner *po; 3972 struct pmc_sample *ps; 3973 struct pmc_classdep *pcd; 3974 struct pmc_samplebuffer *psb; 3975 3976 KASSERT(PCPU_GET(cpuid) == cpu, 3977 ("[pmc,%d] not on the correct CPU pcpu=%d cpu=%d", __LINE__, 3978 PCPU_GET(cpuid), cpu)); 3979 3980 psb = pmc_pcpu[cpu]->pc_sb; 3981 3982 for (n = 0; n < pmc_nsamples; n++) { /* bound on #iterations */ 3983 3984 ps = psb->ps_read; 3985 if (ps->ps_nsamples == PMC_SAMPLE_FREE) 3986 break; 3987 if (ps->ps_nsamples == PMC_SAMPLE_INUSE) { 3988 /* Need a rescan at a later time. */ 3989 atomic_set_rel_int(&pmc_cpumask, (1 << cpu)); 3990 break; 3991 } 3992 3993 pm = ps->ps_pmc; 3994 po = pm->pm_owner; 3995 3996 KASSERT(PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)), 3997 ("[pmc,%d] pmc=%p non-sampling mode=%d", __LINE__, 3998 pm, PMC_TO_MODE(pm))); 3999 4000 /* Ignore PMCs that have been switched off */ 4001 if (pm->pm_state != PMC_STATE_RUNNING) 4002 goto entrydone; 4003 4004 PMCDBG(SAM,OPS,1,"cpu=%d pm=%p n=%d fl=%x wr=%d rd=%d", cpu, 4005 pm, ps->ps_nsamples, ps->ps_flags, 4006 (int) (psb->ps_write - psb->ps_samples), 4007 (int) (psb->ps_read - psb->ps_samples)); 4008 4009 /* 4010 * If this is a process-mode PMC that is attached to 4011 * its owner, and if the PC is in user mode, update 4012 * profiling statistics like timer-based profiling 4013 * would have done. 4014 */ 4015 if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) { 4016 if (ps->ps_flags & PMC_CC_F_USERSPACE) { 4017 td = FIRST_THREAD_IN_PROC(po->po_owner); 4018 addupc_intr(td, ps->ps_pc[0], 1); 4019 } 4020 goto entrydone; 4021 } 4022 4023 /* 4024 * Otherwise, this is either a sampling mode PMC that 4025 * is attached to a different process than its owner, 4026 * or a system-wide sampling PMC. Dispatch a log 4027 * entry to the PMC's owner process. 4028 */ 4029 4030 pmclog_process_callchain(pm, ps); 4031 4032 entrydone: 4033 ps->ps_nsamples = 0; /* mark entry as free */ 4034 atomic_subtract_rel_32(&pm->pm_runcount, 1); 4035 4036 /* increment read pointer, modulo sample size */ 4037 if (++ps == psb->ps_fence) 4038 psb->ps_read = psb->ps_samples; 4039 else 4040 psb->ps_read = ps; 4041 } 4042 4043 atomic_add_int(&pmc_stats.pm_log_sweeps, 1); 4044 4045 /* Do not re-enable stalled PMCs if we failed to process any samples */ 4046 if (n == 0) 4047 return; 4048 4049 /* 4050 * Restart any stalled sampling PMCs on this CPU. 4051 * 4052 * If the NMI handler sets the pm_stalled field of a PMC after 4053 * the check below, we'll end up processing the stalled PMC at 4054 * the next hardclock tick. 4055 */ 4056 for (n = 0; n < md->pmd_npmc; n++) { 4057 pcd = pmc_ri_to_classdep(md, n, &adjri); 4058 KASSERT(pcd != NULL, 4059 ("[pmc,%d] null pcd ri=%d", __LINE__, n)); 4060 (void) (*pcd->pcd_get_config)(cpu,adjri,&pm); 4061 4062 if (pm == NULL || /* !cfg'ed */ 4063 pm->pm_state != PMC_STATE_RUNNING || /* !active */ 4064 !PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)) || /* !sampling */ 4065 pm->pm_stalled == 0) /* !stalled */ 4066 continue; 4067 4068 pm->pm_stalled = 0; 4069 (*pcd->pcd_start_pmc)(cpu, adjri); 4070 } 4071} 4072 4073/* 4074 * Event handlers. 4075 */ 4076 4077/* 4078 * Handle a process exit. 4079 * 4080 * Remove this process from all hash tables. If this process 4081 * owned any PMCs, turn off those PMCs and deallocate them, 4082 * removing any associations with target processes. 4083 * 4084 * This function will be called by the last 'thread' of a 4085 * process. 4086 * 4087 * XXX This eventhandler gets called early in the exit process. 4088 * Consider using a 'hook' invocation from thread_exit() or equivalent 4089 * spot. Another negative is that kse_exit doesn't seem to call 4090 * exit1() [??]. 4091 * 4092 */ 4093 4094static void 4095pmc_process_exit(void *arg __unused, struct proc *p) 4096{ 4097 struct pmc *pm; 4098 int adjri, cpu; 4099 unsigned int ri; 4100 int is_using_hwpmcs; 4101 struct pmc_owner *po; 4102 struct pmc_process *pp; 4103 struct pmc_classdep *pcd; 4104 pmc_value_t newvalue, tmp; 4105 4106 PROC_LOCK(p); 4107 is_using_hwpmcs = p->p_flag & P_HWPMC; 4108 PROC_UNLOCK(p); 4109 4110 /* 4111 * Log a sysexit event to all SS PMC owners. 4112 */ 4113 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 4114 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 4115 pmclog_process_sysexit(po, p->p_pid); 4116 4117 if (!is_using_hwpmcs) 4118 return; 4119 4120 PMC_GET_SX_XLOCK(); 4121 PMCDBG(PRC,EXT,1,"process-exit proc=%p (%d, %s)", p, p->p_pid, 4122 p->p_comm); 4123 4124 /* 4125 * Since this code is invoked by the last thread in an exiting 4126 * process, we would have context switched IN at some prior 4127 * point. However, with PREEMPTION, kernel mode context 4128 * switches may happen any time, so we want to disable a 4129 * context switch OUT till we get any PMCs targetting this 4130 * process off the hardware. 4131 * 4132 * We also need to atomically remove this process' 4133 * entry from our target process hash table, using 4134 * PMC_FLAG_REMOVE. 4135 */ 4136 PMCDBG(PRC,EXT,1, "process-exit proc=%p (%d, %s)", p, p->p_pid, 4137 p->p_comm); 4138 4139 critical_enter(); /* no preemption */ 4140 4141 cpu = curthread->td_oncpu; 4142 4143 if ((pp = pmc_find_process_descriptor(p, 4144 PMC_FLAG_REMOVE)) != NULL) { 4145 4146 PMCDBG(PRC,EXT,2, 4147 "process-exit proc=%p pmc-process=%p", p, pp); 4148 4149 /* 4150 * The exiting process could the target of 4151 * some PMCs which will be running on 4152 * currently executing CPU. 4153 * 4154 * We need to turn these PMCs off like we 4155 * would do at context switch OUT time. 4156 */ 4157 for (ri = 0; ri < md->pmd_npmc; ri++) { 4158 4159 /* 4160 * Pick up the pmc pointer from hardware 4161 * state similar to the CSW_OUT code. 4162 */ 4163 pm = NULL; 4164 4165 pcd = pmc_ri_to_classdep(md, ri, &adjri); 4166 4167 (void) (*pcd->pcd_get_config)(cpu, adjri, &pm); 4168 4169 PMCDBG(PRC,EXT,2, "ri=%d pm=%p", ri, pm); 4170 4171 if (pm == NULL || 4172 !PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) 4173 continue; 4174 4175 PMCDBG(PRC,EXT,2, "ppmcs[%d]=%p pm=%p " 4176 "state=%d", ri, pp->pp_pmcs[ri].pp_pmc, 4177 pm, pm->pm_state); 4178 4179 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 4180 ("[pmc,%d] ri mismatch pmc(%d) ri(%d)", 4181 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 4182 4183 KASSERT(pm == pp->pp_pmcs[ri].pp_pmc, 4184 ("[pmc,%d] pm %p != pp_pmcs[%d] %p", 4185 __LINE__, pm, ri, pp->pp_pmcs[ri].pp_pmc)); 4186 4187 (void) pcd->pcd_stop_pmc(cpu, adjri); 4188 4189 KASSERT(pm->pm_runcount > 0, 4190 ("[pmc,%d] bad runcount ri %d rc %d", 4191 __LINE__, ri, pm->pm_runcount)); 4192 4193 /* Stop hardware only if it is actually running */ 4194 if (pm->pm_state == PMC_STATE_RUNNING && 4195 pm->pm_stalled == 0) { 4196 pcd->pcd_read_pmc(cpu, adjri, &newvalue); 4197 tmp = newvalue - 4198 PMC_PCPU_SAVED(cpu,ri); 4199 4200 mtx_pool_lock_spin(pmc_mtxpool, pm); 4201 pm->pm_gv.pm_savedvalue += tmp; 4202 pp->pp_pmcs[ri].pp_pmcval += tmp; 4203 mtx_pool_unlock_spin(pmc_mtxpool, pm); 4204 } 4205 4206 atomic_subtract_rel_32(&pm->pm_runcount,1); 4207 4208 KASSERT((int) pm->pm_runcount >= 0, 4209 ("[pmc,%d] runcount is %d", __LINE__, ri)); 4210 4211 (void) pcd->pcd_config_pmc(cpu, adjri, NULL); 4212 } 4213 4214 /* 4215 * Inform the MD layer of this pseudo "context switch 4216 * out" 4217 */ 4218 (void) md->pmd_switch_out(pmc_pcpu[cpu], pp); 4219 4220 critical_exit(); /* ok to be pre-empted now */ 4221 4222 /* 4223 * Unlink this process from the PMCs that are 4224 * targetting it. This will send a signal to 4225 * all PMC owner's whose PMCs are orphaned. 4226 * 4227 * Log PMC value at exit time if requested. 4228 */ 4229 for (ri = 0; ri < md->pmd_npmc; ri++) 4230 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) { 4231 if (pm->pm_flags & PMC_F_NEEDS_LOGFILE && 4232 PMC_IS_COUNTING_MODE(PMC_TO_MODE(pm))) 4233 pmclog_process_procexit(pm, pp); 4234 pmc_unlink_target_process(pm, pp); 4235 } 4236 free(pp, M_PMC); 4237 4238 } else 4239 critical_exit(); /* pp == NULL */ 4240 4241 4242 /* 4243 * If the process owned PMCs, free them up and free up 4244 * memory. 4245 */ 4246 if ((po = pmc_find_owner_descriptor(p)) != NULL) { 4247 pmc_remove_owner(po); 4248 pmc_destroy_owner_descriptor(po); 4249 } 4250 4251 sx_xunlock(&pmc_sx); 4252} 4253 4254/* 4255 * Handle a process fork. 4256 * 4257 * If the parent process 'p1' is under HWPMC monitoring, then copy 4258 * over any attached PMCs that have 'do_descendants' semantics. 4259 */ 4260 4261static void 4262pmc_process_fork(void *arg __unused, struct proc *p1, struct proc *newproc, 4263 int flags) 4264{ 4265 int is_using_hwpmcs; 4266 unsigned int ri; 4267 uint32_t do_descendants; 4268 struct pmc *pm; 4269 struct pmc_owner *po; 4270 struct pmc_process *ppnew, *ppold; 4271 4272 (void) flags; /* unused parameter */ 4273 4274 PROC_LOCK(p1); 4275 is_using_hwpmcs = p1->p_flag & P_HWPMC; 4276 PROC_UNLOCK(p1); 4277 4278 /* 4279 * If there are system-wide sampling PMCs active, we need to 4280 * log all fork events to their owner's logs. 4281 */ 4282 4283 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 4284 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 4285 pmclog_process_procfork(po, p1->p_pid, newproc->p_pid); 4286 4287 if (!is_using_hwpmcs) 4288 return; 4289 4290 PMC_GET_SX_XLOCK(); 4291 PMCDBG(PMC,FRK,1, "process-fork proc=%p (%d, %s) -> %p", p1, 4292 p1->p_pid, p1->p_comm, newproc); 4293 4294 /* 4295 * If the parent process (curthread->td_proc) is a 4296 * target of any PMCs, look for PMCs that are to be 4297 * inherited, and link these into the new process 4298 * descriptor. 4299 */ 4300 if ((ppold = pmc_find_process_descriptor(curthread->td_proc, 4301 PMC_FLAG_NONE)) == NULL) 4302 goto done; /* nothing to do */ 4303 4304 do_descendants = 0; 4305 for (ri = 0; ri < md->pmd_npmc; ri++) 4306 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL) 4307 do_descendants |= pm->pm_flags & PMC_F_DESCENDANTS; 4308 if (do_descendants == 0) /* nothing to do */ 4309 goto done; 4310 4311 /* allocate a descriptor for the new process */ 4312 if ((ppnew = pmc_find_process_descriptor(newproc, 4313 PMC_FLAG_ALLOCATE)) == NULL) 4314 goto done; 4315 4316 /* 4317 * Run through all PMCs that were targeting the old process 4318 * and which specified F_DESCENDANTS and attach them to the 4319 * new process. 4320 * 4321 * Log the fork event to all owners of PMCs attached to this 4322 * process, if not already logged. 4323 */ 4324 for (ri = 0; ri < md->pmd_npmc; ri++) 4325 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL && 4326 (pm->pm_flags & PMC_F_DESCENDANTS)) { 4327 pmc_link_target_process(pm, ppnew); 4328 po = pm->pm_owner; 4329 if (po->po_sscount == 0 && 4330 po->po_flags & PMC_PO_OWNS_LOGFILE) 4331 pmclog_process_procfork(po, p1->p_pid, 4332 newproc->p_pid); 4333 } 4334 4335 /* 4336 * Now mark the new process as being tracked by this driver. 4337 */ 4338 PROC_LOCK(newproc); 4339 newproc->p_flag |= P_HWPMC; 4340 PROC_UNLOCK(newproc); 4341 4342 done: 4343 sx_xunlock(&pmc_sx); 4344} 4345 4346 4347/* 4348 * initialization 4349 */ 4350 4351static const char *pmc_name_of_pmcclass[] = { 4352#undef __PMC_CLASS 4353#define __PMC_CLASS(N) #N , 4354 __PMC_CLASSES() 4355}; 4356 4357static int 4358pmc_initialize(void) 4359{ 4360 int c, cpu, error, n, ri; 4361 unsigned int maxcpu; 4362 struct pmc_binding pb; 4363 struct pmc_sample *ps; 4364 struct pmc_classdep *pcd; 4365 struct pmc_samplebuffer *sb; 4366 4367 md = NULL; 4368 error = 0; 4369 4370#ifdef DEBUG 4371 /* parse debug flags first */ 4372 if (TUNABLE_STR_FETCH(PMC_SYSCTL_NAME_PREFIX "debugflags", 4373 pmc_debugstr, sizeof(pmc_debugstr))) 4374 pmc_debugflags_parse(pmc_debugstr, 4375 pmc_debugstr+strlen(pmc_debugstr)); 4376#endif 4377 4378 PMCDBG(MOD,INI,0, "PMC Initialize (version %x)", PMC_VERSION); 4379 4380 /* check kernel version */ 4381 if (pmc_kernel_version != PMC_VERSION) { 4382 if (pmc_kernel_version == 0) 4383 printf("hwpmc: this kernel has not been compiled with " 4384 "'options HWPMC_HOOKS'.\n"); 4385 else 4386 printf("hwpmc: kernel version (0x%x) does not match " 4387 "module version (0x%x).\n", pmc_kernel_version, 4388 PMC_VERSION); 4389 return EPROGMISMATCH; 4390 } 4391 4392 /* 4393 * check sysctl parameters 4394 */ 4395 4396 if (pmc_hashsize <= 0) { 4397 (void) printf("hwpmc: tunable \"hashsize\"=%d must be " 4398 "greater than zero.\n", pmc_hashsize); 4399 pmc_hashsize = PMC_HASH_SIZE; 4400 } 4401 4402 if (pmc_nsamples <= 0 || pmc_nsamples > 65535) { 4403 (void) printf("hwpmc: tunable \"nsamples\"=%d out of " 4404 "range.\n", pmc_nsamples); 4405 pmc_nsamples = PMC_NSAMPLES; 4406 } 4407 4408 if (pmc_callchaindepth <= 0 || 4409 pmc_callchaindepth > PMC_CALLCHAIN_DEPTH_MAX) { 4410 (void) printf("hwpmc: tunable \"callchaindepth\"=%d out of " 4411 "range.\n", pmc_callchaindepth); 4412 pmc_callchaindepth = PMC_CALLCHAIN_DEPTH; 4413 } 4414 4415 md = pmc_md_initialize(); 4416 4417 if (md == NULL) 4418 return (ENOSYS); 4419 4420 KASSERT(md->pmd_nclass >= 1 && md->pmd_npmc >= 1, 4421 ("[pmc,%d] no classes or pmcs", __LINE__)); 4422 4423 /* Compute the map from row-indices to classdep pointers. */ 4424 pmc_rowindex_to_classdep = malloc(sizeof(struct pmc_classdep *) * 4425 md->pmd_npmc, M_PMC, M_WAITOK|M_ZERO); 4426 4427 for (n = 0; n < md->pmd_npmc; n++) 4428 pmc_rowindex_to_classdep[n] = NULL; 4429 for (ri = c = 0; c < md->pmd_nclass; c++) { 4430 pcd = &md->pmd_classdep[c]; 4431 for (n = 0; n < pcd->pcd_num; n++, ri++) 4432 pmc_rowindex_to_classdep[ri] = pcd; 4433 } 4434 4435 KASSERT(ri == md->pmd_npmc, 4436 ("[pmc,%d] npmc miscomputed: ri=%d, md->npmc=%d", __LINE__, 4437 ri, md->pmd_npmc)); 4438 4439 maxcpu = pmc_cpu_max(); 4440 4441 /* allocate space for the per-cpu array */ 4442 pmc_pcpu = malloc(maxcpu * sizeof(struct pmc_cpu *), M_PMC, 4443 M_WAITOK|M_ZERO); 4444 4445 /* per-cpu 'saved values' for managing process-mode PMCs */ 4446 pmc_pcpu_saved = malloc(sizeof(pmc_value_t) * maxcpu * md->pmd_npmc, 4447 M_PMC, M_WAITOK); 4448 4449 /* Perform CPU-dependent initialization. */ 4450 pmc_save_cpu_binding(&pb); 4451 error = 0; 4452 for (cpu = 0; error == 0 && cpu < maxcpu; cpu++) { 4453 if (!pmc_cpu_is_active(cpu)) 4454 continue; 4455 pmc_select_cpu(cpu); 4456 pmc_pcpu[cpu] = malloc(sizeof(struct pmc_cpu) + 4457 md->pmd_npmc * sizeof(struct pmc_hw *), M_PMC, 4458 M_WAITOK|M_ZERO); 4459 if (md->pmd_pcpu_init) 4460 error = md->pmd_pcpu_init(md, cpu); 4461 for (n = 0; error == 0 && n < md->pmd_nclass; n++) 4462 error = md->pmd_classdep[n].pcd_pcpu_init(md, cpu); 4463 } 4464 pmc_restore_cpu_binding(&pb); 4465 4466 if (error) 4467 return (error); 4468 4469 /* allocate space for the sample array */ 4470 for (cpu = 0; cpu < maxcpu; cpu++) { 4471 if (!pmc_cpu_is_active(cpu)) 4472 continue; 4473 4474 sb = malloc(sizeof(struct pmc_samplebuffer) + 4475 pmc_nsamples * sizeof(struct pmc_sample), M_PMC, 4476 M_WAITOK|M_ZERO); 4477 sb->ps_read = sb->ps_write = sb->ps_samples; 4478 sb->ps_fence = sb->ps_samples + pmc_nsamples; 4479 4480 KASSERT(pmc_pcpu[cpu] != NULL, 4481 ("[pmc,%d] cpu=%d Null per-cpu data", __LINE__, cpu)); 4482 4483 sb->ps_callchains = malloc(pmc_callchaindepth * pmc_nsamples * 4484 sizeof(uintptr_t), M_PMC, M_WAITOK|M_ZERO); 4485 4486 for (n = 0, ps = sb->ps_samples; n < pmc_nsamples; n++, ps++) 4487 ps->ps_pc = sb->ps_callchains + 4488 (n * pmc_callchaindepth); 4489 4490 pmc_pcpu[cpu]->pc_sb = sb; 4491 } 4492 4493 /* allocate space for the row disposition array */ 4494 pmc_pmcdisp = malloc(sizeof(enum pmc_mode) * md->pmd_npmc, 4495 M_PMC, M_WAITOK|M_ZERO); 4496 4497 KASSERT(pmc_pmcdisp != NULL, 4498 ("[pmc,%d] pmcdisp allocation returned NULL", __LINE__)); 4499 4500 /* mark all PMCs as available */ 4501 for (n = 0; n < (int) md->pmd_npmc; n++) 4502 PMC_MARK_ROW_FREE(n); 4503 4504 /* allocate thread hash tables */ 4505 pmc_ownerhash = hashinit(pmc_hashsize, M_PMC, 4506 &pmc_ownerhashmask); 4507 4508 pmc_processhash = hashinit(pmc_hashsize, M_PMC, 4509 &pmc_processhashmask); 4510 mtx_init(&pmc_processhash_mtx, "pmc-process-hash", "pmc-leaf", 4511 MTX_SPIN); 4512 4513 LIST_INIT(&pmc_ss_owners); 4514 pmc_ss_count = 0; 4515 4516 /* allocate a pool of spin mutexes */ 4517 pmc_mtxpool = mtx_pool_create("pmc-leaf", pmc_mtxpool_size, 4518 MTX_SPIN); 4519 4520 PMCDBG(MOD,INI,1, "pmc_ownerhash=%p, mask=0x%lx " 4521 "targethash=%p mask=0x%lx", pmc_ownerhash, pmc_ownerhashmask, 4522 pmc_processhash, pmc_processhashmask); 4523 4524 /* register process {exit,fork,exec} handlers */ 4525 pmc_exit_tag = EVENTHANDLER_REGISTER(process_exit, 4526 pmc_process_exit, NULL, EVENTHANDLER_PRI_ANY); 4527 pmc_fork_tag = EVENTHANDLER_REGISTER(process_fork, 4528 pmc_process_fork, NULL, EVENTHANDLER_PRI_ANY); 4529 4530 /* initialize logging */ 4531 pmclog_initialize(); 4532 4533 /* set hook functions */ 4534 pmc_intr = md->pmd_intr; 4535 pmc_hook = pmc_hook_handler; 4536 4537 if (error == 0) { 4538 printf(PMC_MODULE_NAME ":"); 4539 for (n = 0; n < (int) md->pmd_nclass; n++) { 4540 pcd = &md->pmd_classdep[n]; 4541 printf(" %s/%d/%d/0x%b", 4542 pmc_name_of_pmcclass[pcd->pcd_class], 4543 pcd->pcd_num, 4544 pcd->pcd_width, 4545 pcd->pcd_caps, 4546 "\20" 4547 "\1INT\2USR\3SYS\4EDG\5THR" 4548 "\6REA\7WRI\10INV\11QUA\12PRC" 4549 "\13TAG\14CSC"); 4550 } 4551 printf("\n"); 4552 } 4553 4554 return (error); 4555} 4556 4557/* prepare to be unloaded */ 4558static void 4559pmc_cleanup(void) 4560{ 4561 int c, cpu; 4562 unsigned int maxcpu; 4563 struct pmc_ownerhash *ph; 4564 struct pmc_owner *po, *tmp; 4565 struct pmc_binding pb; 4566#ifdef DEBUG 4567 struct pmc_processhash *prh; 4568#endif 4569 4570 PMCDBG(MOD,INI,0, "%s", "cleanup"); 4571 4572 /* switch off sampling */ 4573 atomic_store_rel_int(&pmc_cpumask, 0); 4574 pmc_intr = NULL; 4575 4576 sx_xlock(&pmc_sx); 4577 if (pmc_hook == NULL) { /* being unloaded already */ 4578 sx_xunlock(&pmc_sx); 4579 return; 4580 } 4581 4582 pmc_hook = NULL; /* prevent new threads from entering module */ 4583 4584 /* deregister event handlers */ 4585 EVENTHANDLER_DEREGISTER(process_fork, pmc_fork_tag); 4586 EVENTHANDLER_DEREGISTER(process_exit, pmc_exit_tag); 4587 4588 /* send SIGBUS to all owner threads, free up allocations */ 4589 if (pmc_ownerhash) 4590 for (ph = pmc_ownerhash; 4591 ph <= &pmc_ownerhash[pmc_ownerhashmask]; 4592 ph++) { 4593 LIST_FOREACH_SAFE(po, ph, po_next, tmp) { 4594 pmc_remove_owner(po); 4595 4596 /* send SIGBUS to owner processes */ 4597 PMCDBG(MOD,INI,2, "cleanup signal proc=%p " 4598 "(%d, %s)", po->po_owner, 4599 po->po_owner->p_pid, 4600 po->po_owner->p_comm); 4601 4602 PROC_LOCK(po->po_owner); 4603 psignal(po->po_owner, SIGBUS); 4604 PROC_UNLOCK(po->po_owner); 4605 4606 pmc_destroy_owner_descriptor(po); 4607 } 4608 } 4609 4610 /* reclaim allocated data structures */ 4611 if (pmc_mtxpool) 4612 mtx_pool_destroy(&pmc_mtxpool); 4613 4614 mtx_destroy(&pmc_processhash_mtx); 4615 if (pmc_processhash) { 4616#ifdef DEBUG 4617 struct pmc_process *pp; 4618 4619 PMCDBG(MOD,INI,3, "%s", "destroy process hash"); 4620 for (prh = pmc_processhash; 4621 prh <= &pmc_processhash[pmc_processhashmask]; 4622 prh++) 4623 LIST_FOREACH(pp, prh, pp_next) 4624 PMCDBG(MOD,INI,3, "pid=%d", pp->pp_proc->p_pid); 4625#endif 4626 4627 hashdestroy(pmc_processhash, M_PMC, pmc_processhashmask); 4628 pmc_processhash = NULL; 4629 } 4630 4631 if (pmc_ownerhash) { 4632 PMCDBG(MOD,INI,3, "%s", "destroy owner hash"); 4633 hashdestroy(pmc_ownerhash, M_PMC, pmc_ownerhashmask); 4634 pmc_ownerhash = NULL; 4635 } 4636 4637 KASSERT(LIST_EMPTY(&pmc_ss_owners), 4638 ("[pmc,%d] Global SS owner list not empty", __LINE__)); 4639 KASSERT(pmc_ss_count == 0, 4640 ("[pmc,%d] Global SS count not empty", __LINE__)); 4641 4642 /* do processor and pmc-class dependent cleanup */ 4643 maxcpu = pmc_cpu_max(); 4644 4645 PMCDBG(MOD,INI,3, "%s", "md cleanup"); 4646 if (md) { 4647 pmc_save_cpu_binding(&pb); 4648 for (cpu = 0; cpu < maxcpu; cpu++) { 4649 PMCDBG(MOD,INI,1,"pmc-cleanup cpu=%d pcs=%p", 4650 cpu, pmc_pcpu[cpu]); 4651 if (!pmc_cpu_is_active(cpu) || pmc_pcpu[cpu] == NULL) 4652 continue; 4653 pmc_select_cpu(cpu); 4654 for (c = 0; c < md->pmd_nclass; c++) 4655 md->pmd_classdep[c].pcd_pcpu_fini(md, cpu); 4656 if (md->pmd_pcpu_fini) 4657 md->pmd_pcpu_fini(md, cpu); 4658 } 4659 4660 pmc_md_finalize(md); 4661 4662 free(md, M_PMC); 4663 md = NULL; 4664 pmc_restore_cpu_binding(&pb); 4665 } 4666 4667 /* Free per-cpu descriptors. */ 4668 for (cpu = 0; cpu < maxcpu; cpu++) { 4669 if (!pmc_cpu_is_active(cpu)) 4670 continue; 4671 KASSERT(pmc_pcpu[cpu]->pc_sb != NULL, 4672 ("[pmc,%d] Null cpu sample buffer cpu=%d", __LINE__, 4673 cpu)); 4674 free(pmc_pcpu[cpu]->pc_sb->ps_callchains, M_PMC); 4675 free(pmc_pcpu[cpu]->pc_sb, M_PMC); 4676 free(pmc_pcpu[cpu], M_PMC); 4677 } 4678 4679 free(pmc_pcpu, M_PMC); 4680 pmc_pcpu = NULL; 4681 4682 free(pmc_pcpu_saved, M_PMC); 4683 pmc_pcpu_saved = NULL; 4684 4685 if (pmc_pmcdisp) { 4686 free(pmc_pmcdisp, M_PMC); 4687 pmc_pmcdisp = NULL; 4688 } 4689 4690 if (pmc_rowindex_to_classdep) { 4691 free(pmc_rowindex_to_classdep, M_PMC); 4692 pmc_rowindex_to_classdep = NULL; 4693 } 4694 4695 pmclog_shutdown(); 4696 4697 sx_xunlock(&pmc_sx); /* we are done */ 4698} 4699 4700/* 4701 * The function called at load/unload. 4702 */ 4703 4704static int 4705load (struct module *module __unused, int cmd, void *arg __unused) 4706{ 4707 int error; 4708 4709 error = 0; 4710 4711 switch (cmd) { 4712 case MOD_LOAD : 4713 /* initialize the subsystem */ 4714 error = pmc_initialize(); 4715 if (error != 0) 4716 break; 4717 PMCDBG(MOD,INI,1, "syscall=%d maxcpu=%d", 4718 pmc_syscall_num, pmc_cpu_max()); 4719 break; 4720 4721 4722 case MOD_UNLOAD : 4723 case MOD_SHUTDOWN: 4724 pmc_cleanup(); 4725 PMCDBG(MOD,INI,1, "%s", "unloaded"); 4726 break; 4727 4728 default : 4729 error = EINVAL; /* XXX should panic(9) */ 4730 break; 4731 } 4732 4733 return error; 4734} 4735 4736/* memory pool */ 4737MALLOC_DEFINE(M_PMC, "pmc", "Memory space for the PMC module"); 4738