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