hwpmc_mod.c revision 280455
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: stable/10/sys/dev/hwpmc/hwpmc_mod.c 280455 2015-03-24 20:00:11Z rrs $"); 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 void pmc_destroy_pmc_descriptor(struct pmc *pm); 196static struct pmc_owner *pmc_find_owner_descriptor(struct proc *p); 197static int pmc_find_pmc(pmc_id_t pmcid, struct pmc **pm); 198static struct pmc *pmc_find_pmc_descriptor_in_process(struct pmc_owner *po, 199 pmc_id_t pmc); 200static struct pmc_process *pmc_find_process_descriptor(struct proc *p, 201 uint32_t mode); 202static void pmc_force_context_switch(void); 203static void pmc_link_target_process(struct pmc *pm, 204 struct pmc_process *pp); 205static void pmc_log_all_process_mappings(struct pmc_owner *po); 206static void pmc_log_kernel_mappings(struct pmc *pm); 207static void pmc_log_process_mappings(struct pmc_owner *po, struct proc *p); 208static void pmc_maybe_remove_owner(struct pmc_owner *po); 209static void pmc_process_csw_in(struct thread *td); 210static void pmc_process_csw_out(struct thread *td); 211static void pmc_process_exit(void *arg, struct proc *p); 212static void pmc_process_fork(void *arg, struct proc *p1, 213 struct proc *p2, int n); 214static void pmc_process_samples(int cpu, int soft); 215static void pmc_release_pmc_descriptor(struct pmc *pmc); 216static void pmc_remove_owner(struct pmc_owner *po); 217static void pmc_remove_process_descriptor(struct pmc_process *pp); 218static void pmc_restore_cpu_binding(struct pmc_binding *pb); 219static void pmc_save_cpu_binding(struct pmc_binding *pb); 220static void pmc_select_cpu(int cpu); 221static int pmc_start(struct pmc *pm); 222static int pmc_stop(struct pmc *pm); 223static int pmc_syscall_handler(struct thread *td, void *syscall_args); 224static void pmc_unlink_target_process(struct pmc *pmc, 225 struct pmc_process *pp); 226static int generic_switch_in(struct pmc_cpu *pc, struct pmc_process *pp); 227static int generic_switch_out(struct pmc_cpu *pc, struct pmc_process *pp); 228static struct pmc_mdep *pmc_generic_cpu_initialize(void); 229static void pmc_generic_cpu_finalize(struct pmc_mdep *md); 230 231/* 232 * Kernel tunables and sysctl(8) interface. 233 */ 234 235SYSCTL_DECL(_kern_hwpmc); 236 237static int pmc_callchaindepth = PMC_CALLCHAIN_DEPTH; 238TUNABLE_INT(PMC_SYSCTL_NAME_PREFIX "callchaindepth", &pmc_callchaindepth); 239SYSCTL_INT(_kern_hwpmc, OID_AUTO, callchaindepth, CTLFLAG_TUN|CTLFLAG_RD, 240 &pmc_callchaindepth, 0, "depth of call chain records"); 241 242#ifdef DEBUG 243struct pmc_debugflags pmc_debugflags = PMC_DEBUG_DEFAULT_FLAGS; 244char pmc_debugstr[PMC_DEBUG_STRSIZE]; 245TUNABLE_STR(PMC_SYSCTL_NAME_PREFIX "debugflags", pmc_debugstr, 246 sizeof(pmc_debugstr)); 247SYSCTL_PROC(_kern_hwpmc, OID_AUTO, debugflags, 248 CTLTYPE_STRING|CTLFLAG_RW|CTLFLAG_TUN, 249 0, 0, pmc_debugflags_sysctl_handler, "A", "debug flags"); 250#endif 251 252/* 253 * kern.hwpmc.hashrows -- determines the number of rows in the 254 * of the hash table used to look up threads 255 */ 256 257static int pmc_hashsize = PMC_HASH_SIZE; 258TUNABLE_INT(PMC_SYSCTL_NAME_PREFIX "hashsize", &pmc_hashsize); 259SYSCTL_INT(_kern_hwpmc, OID_AUTO, hashsize, CTLFLAG_TUN|CTLFLAG_RD, 260 &pmc_hashsize, 0, "rows in hash tables"); 261 262/* 263 * kern.hwpmc.nsamples --- number of PC samples/callchain stacks per CPU 264 */ 265 266static int pmc_nsamples = PMC_NSAMPLES; 267TUNABLE_INT(PMC_SYSCTL_NAME_PREFIX "nsamples", &pmc_nsamples); 268SYSCTL_INT(_kern_hwpmc, OID_AUTO, nsamples, CTLFLAG_TUN|CTLFLAG_RD, 269 &pmc_nsamples, 0, "number of PC samples per CPU"); 270 271 272/* 273 * kern.hwpmc.mtxpoolsize -- number of mutexes in the mutex pool. 274 */ 275 276static int pmc_mtxpool_size = PMC_MTXPOOL_SIZE; 277TUNABLE_INT(PMC_SYSCTL_NAME_PREFIX "mtxpoolsize", &pmc_mtxpool_size); 278SYSCTL_INT(_kern_hwpmc, OID_AUTO, mtxpoolsize, CTLFLAG_TUN|CTLFLAG_RD, 279 &pmc_mtxpool_size, 0, "size of spin mutex pool"); 280 281 282/* 283 * security.bsd.unprivileged_syspmcs -- allow non-root processes to 284 * allocate system-wide PMCs. 285 * 286 * Allowing unprivileged processes to allocate system PMCs is convenient 287 * if system-wide measurements need to be taken concurrently with other 288 * per-process measurements. This feature is turned off by default. 289 */ 290 291static int pmc_unprivileged_syspmcs = 0; 292TUNABLE_INT("security.bsd.unprivileged_syspmcs", &pmc_unprivileged_syspmcs); 293SYSCTL_INT(_security_bsd, OID_AUTO, unprivileged_syspmcs, CTLFLAG_RW, 294 &pmc_unprivileged_syspmcs, 0, 295 "allow unprivileged process to allocate system PMCs"); 296 297/* 298 * Hash function. Discard the lower 2 bits of the pointer since 299 * these are always zero for our uses. The hash multiplier is 300 * round((2^LONG_BIT) * ((sqrt(5)-1)/2)). 301 */ 302 303#if LONG_BIT == 64 304#define _PMC_HM 11400714819323198486u 305#elif LONG_BIT == 32 306#define _PMC_HM 2654435769u 307#else 308#error Must know the size of 'long' to compile 309#endif 310 311#define PMC_HASH_PTR(P,M) ((((unsigned long) (P) >> 2) * _PMC_HM) & (M)) 312 313/* 314 * Syscall structures 315 */ 316 317/* The `sysent' for the new syscall */ 318static struct sysent pmc_sysent = { 319 2, /* sy_narg */ 320 pmc_syscall_handler /* sy_call */ 321}; 322 323static struct syscall_module_data pmc_syscall_mod = { 324 load, 325 NULL, 326 &pmc_syscall_num, 327 &pmc_sysent, 328#if (__FreeBSD_version >= 1100000) 329 { 0, NULL }, 330 SY_THR_STATIC_KLD, 331#else 332 { 0, NULL } 333#endif 334}; 335 336static moduledata_t pmc_mod = { 337 PMC_MODULE_NAME, 338 syscall_module_handler, 339 &pmc_syscall_mod 340}; 341 342DECLARE_MODULE(pmc, pmc_mod, SI_SUB_SMP, SI_ORDER_ANY); 343MODULE_VERSION(pmc, PMC_VERSION); 344 345#ifdef DEBUG 346enum pmc_dbgparse_state { 347 PMCDS_WS, /* in whitespace */ 348 PMCDS_MAJOR, /* seen a major keyword */ 349 PMCDS_MINOR 350}; 351 352static int 353pmc_debugflags_parse(char *newstr, char *fence) 354{ 355 char c, *p, *q; 356 struct pmc_debugflags *tmpflags; 357 int error, found, *newbits, tmp; 358 size_t kwlen; 359 360 tmpflags = malloc(sizeof(*tmpflags), M_PMC, M_WAITOK|M_ZERO); 361 362 p = newstr; 363 error = 0; 364 365 for (; p < fence && (c = *p); p++) { 366 367 /* skip white space */ 368 if (c == ' ' || c == '\t') 369 continue; 370 371 /* look for a keyword followed by "=" */ 372 for (q = p; p < fence && (c = *p) && c != '='; p++) 373 ; 374 if (c != '=') { 375 error = EINVAL; 376 goto done; 377 } 378 379 kwlen = p - q; 380 newbits = NULL; 381 382 /* lookup flag group name */ 383#define DBG_SET_FLAG_MAJ(S,F) \ 384 if (kwlen == sizeof(S)-1 && strncmp(q, S, kwlen) == 0) \ 385 newbits = &tmpflags->pdb_ ## F; 386 387 DBG_SET_FLAG_MAJ("cpu", CPU); 388 DBG_SET_FLAG_MAJ("csw", CSW); 389 DBG_SET_FLAG_MAJ("logging", LOG); 390 DBG_SET_FLAG_MAJ("module", MOD); 391 DBG_SET_FLAG_MAJ("md", MDP); 392 DBG_SET_FLAG_MAJ("owner", OWN); 393 DBG_SET_FLAG_MAJ("pmc", PMC); 394 DBG_SET_FLAG_MAJ("process", PRC); 395 DBG_SET_FLAG_MAJ("sampling", SAM); 396 397 if (newbits == NULL) { 398 error = EINVAL; 399 goto done; 400 } 401 402 p++; /* skip the '=' */ 403 404 /* Now parse the individual flags */ 405 tmp = 0; 406 newflag: 407 for (q = p; p < fence && (c = *p); p++) 408 if (c == ' ' || c == '\t' || c == ',') 409 break; 410 411 /* p == fence or c == ws or c == "," or c == 0 */ 412 413 if ((kwlen = p - q) == 0) { 414 *newbits = tmp; 415 continue; 416 } 417 418 found = 0; 419#define DBG_SET_FLAG_MIN(S,F) \ 420 if (kwlen == sizeof(S)-1 && strncmp(q, S, kwlen) == 0) \ 421 tmp |= found = (1 << PMC_DEBUG_MIN_ ## F) 422 423 /* a '*' denotes all possible flags in the group */ 424 if (kwlen == 1 && *q == '*') 425 tmp = found = ~0; 426 /* look for individual flag names */ 427 DBG_SET_FLAG_MIN("allocaterow", ALR); 428 DBG_SET_FLAG_MIN("allocate", ALL); 429 DBG_SET_FLAG_MIN("attach", ATT); 430 DBG_SET_FLAG_MIN("bind", BND); 431 DBG_SET_FLAG_MIN("config", CFG); 432 DBG_SET_FLAG_MIN("exec", EXC); 433 DBG_SET_FLAG_MIN("exit", EXT); 434 DBG_SET_FLAG_MIN("find", FND); 435 DBG_SET_FLAG_MIN("flush", FLS); 436 DBG_SET_FLAG_MIN("fork", FRK); 437 DBG_SET_FLAG_MIN("getbuf", GTB); 438 DBG_SET_FLAG_MIN("hook", PMH); 439 DBG_SET_FLAG_MIN("init", INI); 440 DBG_SET_FLAG_MIN("intr", INT); 441 DBG_SET_FLAG_MIN("linktarget", TLK); 442 DBG_SET_FLAG_MIN("mayberemove", OMR); 443 DBG_SET_FLAG_MIN("ops", OPS); 444 DBG_SET_FLAG_MIN("read", REA); 445 DBG_SET_FLAG_MIN("register", REG); 446 DBG_SET_FLAG_MIN("release", REL); 447 DBG_SET_FLAG_MIN("remove", ORM); 448 DBG_SET_FLAG_MIN("sample", SAM); 449 DBG_SET_FLAG_MIN("scheduleio", SIO); 450 DBG_SET_FLAG_MIN("select", SEL); 451 DBG_SET_FLAG_MIN("signal", SIG); 452 DBG_SET_FLAG_MIN("swi", SWI); 453 DBG_SET_FLAG_MIN("swo", SWO); 454 DBG_SET_FLAG_MIN("start", STA); 455 DBG_SET_FLAG_MIN("stop", STO); 456 DBG_SET_FLAG_MIN("syscall", PMS); 457 DBG_SET_FLAG_MIN("unlinktarget", TUL); 458 DBG_SET_FLAG_MIN("write", WRI); 459 if (found == 0) { 460 /* unrecognized flag name */ 461 error = EINVAL; 462 goto done; 463 } 464 465 if (c == 0 || c == ' ' || c == '\t') { /* end of flag group */ 466 *newbits = tmp; 467 continue; 468 } 469 470 p++; 471 goto newflag; 472 } 473 474 /* save the new flag set */ 475 bcopy(tmpflags, &pmc_debugflags, sizeof(pmc_debugflags)); 476 477 done: 478 free(tmpflags, M_PMC); 479 return error; 480} 481 482static int 483pmc_debugflags_sysctl_handler(SYSCTL_HANDLER_ARGS) 484{ 485 char *fence, *newstr; 486 int error; 487 unsigned int n; 488 489 (void) arg1; (void) arg2; /* unused parameters */ 490 491 n = sizeof(pmc_debugstr); 492 newstr = malloc(n, M_PMC, M_WAITOK|M_ZERO); 493 (void) strlcpy(newstr, pmc_debugstr, n); 494 495 error = sysctl_handle_string(oidp, newstr, n, req); 496 497 /* if there is a new string, parse and copy it */ 498 if (error == 0 && req->newptr != NULL) { 499 fence = newstr + (n < req->newlen ? n : req->newlen + 1); 500 if ((error = pmc_debugflags_parse(newstr, fence)) == 0) 501 (void) strlcpy(pmc_debugstr, newstr, 502 sizeof(pmc_debugstr)); 503 } 504 505 free(newstr, M_PMC); 506 507 return error; 508} 509#endif 510 511/* 512 * Map a row index to a classdep structure and return the adjusted row 513 * index for the PMC class index. 514 */ 515static struct pmc_classdep * 516pmc_ri_to_classdep(struct pmc_mdep *md, int ri, int *adjri) 517{ 518 struct pmc_classdep *pcd; 519 520 (void) md; 521 522 KASSERT(ri >= 0 && ri < md->pmd_npmc, 523 ("[pmc,%d] illegal row-index %d", __LINE__, ri)); 524 525 pcd = pmc_rowindex_to_classdep[ri]; 526 527 KASSERT(pcd != NULL, 528 ("[pmc,%d] ri %d null pcd", __LINE__, ri)); 529 530 *adjri = ri - pcd->pcd_ri; 531 532 KASSERT(*adjri >= 0 && *adjri < pcd->pcd_num, 533 ("[pmc,%d] adjusted row-index %d", __LINE__, *adjri)); 534 535 return (pcd); 536} 537 538/* 539 * Concurrency Control 540 * 541 * The driver manages the following data structures: 542 * 543 * - target process descriptors, one per target process 544 * - owner process descriptors (and attached lists), one per owner process 545 * - lookup hash tables for owner and target processes 546 * - PMC descriptors (and attached lists) 547 * - per-cpu hardware state 548 * - the 'hook' variable through which the kernel calls into 549 * this module 550 * - the machine hardware state (managed by the MD layer) 551 * 552 * These data structures are accessed from: 553 * 554 * - thread context-switch code 555 * - interrupt handlers (possibly on multiple cpus) 556 * - kernel threads on multiple cpus running on behalf of user 557 * processes doing system calls 558 * - this driver's private kernel threads 559 * 560 * = Locks and Locking strategy = 561 * 562 * The driver uses four locking strategies for its operation: 563 * 564 * - The global SX lock "pmc_sx" is used to protect internal 565 * data structures. 566 * 567 * Calls into the module by syscall() start with this lock being 568 * held in exclusive mode. Depending on the requested operation, 569 * the lock may be downgraded to 'shared' mode to allow more 570 * concurrent readers into the module. Calls into the module from 571 * other parts of the kernel acquire the lock in shared mode. 572 * 573 * This SX lock is held in exclusive mode for any operations that 574 * modify the linkages between the driver's internal data structures. 575 * 576 * The 'pmc_hook' function pointer is also protected by this lock. 577 * It is only examined with the sx lock held in exclusive mode. The 578 * kernel module is allowed to be unloaded only with the sx lock held 579 * in exclusive mode. In normal syscall handling, after acquiring the 580 * pmc_sx lock we first check that 'pmc_hook' is non-null before 581 * proceeding. This prevents races between the thread unloading the module 582 * and other threads seeking to use the module. 583 * 584 * - Lookups of target process structures and owner process structures 585 * cannot use the global "pmc_sx" SX lock because these lookups need 586 * to happen during context switches and in other critical sections 587 * where sleeping is not allowed. We protect these lookup tables 588 * with their own private spin-mutexes, "pmc_processhash_mtx" and 589 * "pmc_ownerhash_mtx". 590 * 591 * - Interrupt handlers work in a lock free manner. At interrupt 592 * time, handlers look at the PMC pointer (phw->phw_pmc) configured 593 * when the PMC was started. If this pointer is NULL, the interrupt 594 * is ignored after updating driver statistics. We ensure that this 595 * pointer is set (using an atomic operation if necessary) before the 596 * PMC hardware is started. Conversely, this pointer is unset atomically 597 * only after the PMC hardware is stopped. 598 * 599 * We ensure that everything needed for the operation of an 600 * interrupt handler is available without it needing to acquire any 601 * locks. We also ensure that a PMC's software state is destroyed only 602 * after the PMC is taken off hardware (on all CPUs). 603 * 604 * - Context-switch handling with process-private PMCs needs more 605 * care. 606 * 607 * A given process may be the target of multiple PMCs. For example, 608 * PMCATTACH and PMCDETACH may be requested by a process on one CPU 609 * while the target process is running on another. A PMC could also 610 * be getting released because its owner is exiting. We tackle 611 * these situations in the following manner: 612 * 613 * - each target process structure 'pmc_process' has an array 614 * of 'struct pmc *' pointers, one for each hardware PMC. 615 * 616 * - At context switch IN time, each "target" PMC in RUNNING state 617 * gets started on hardware and a pointer to each PMC is copied into 618 * the per-cpu phw array. The 'runcount' for the PMC is 619 * incremented. 620 * 621 * - At context switch OUT time, all process-virtual PMCs are stopped 622 * on hardware. The saved value is added to the PMCs value field 623 * only if the PMC is in a non-deleted state (the PMCs state could 624 * have changed during the current time slice). 625 * 626 * Note that since in-between a switch IN on a processor and a switch 627 * OUT, the PMC could have been released on another CPU. Therefore 628 * context switch OUT always looks at the hardware state to turn 629 * OFF PMCs and will update a PMC's saved value only if reachable 630 * from the target process record. 631 * 632 * - OP PMCRELEASE could be called on a PMC at any time (the PMC could 633 * be attached to many processes at the time of the call and could 634 * be active on multiple CPUs). 635 * 636 * We prevent further scheduling of the PMC by marking it as in 637 * state 'DELETED'. If the runcount of the PMC is non-zero then 638 * this PMC is currently running on a CPU somewhere. The thread 639 * doing the PMCRELEASE operation waits by repeatedly doing a 640 * pause() till the runcount comes to zero. 641 * 642 * The contents of a PMC descriptor (struct pmc) are protected using 643 * a spin-mutex. In order to save space, we use a mutex pool. 644 * 645 * In terms of lock types used by witness(4), we use: 646 * - Type "pmc-sx", used by the global SX lock. 647 * - Type "pmc-sleep", for sleep mutexes used by logger threads. 648 * - Type "pmc-per-proc", for protecting PMC owner descriptors. 649 * - Type "pmc-leaf", used for all other spin mutexes. 650 */ 651 652/* 653 * save the cpu binding of the current kthread 654 */ 655 656static void 657pmc_save_cpu_binding(struct pmc_binding *pb) 658{ 659 PMCDBG(CPU,BND,2, "%s", "save-cpu"); 660 thread_lock(curthread); 661 pb->pb_bound = sched_is_bound(curthread); 662 pb->pb_cpu = curthread->td_oncpu; 663 thread_unlock(curthread); 664 PMCDBG(CPU,BND,2, "save-cpu cpu=%d", pb->pb_cpu); 665} 666 667/* 668 * restore the cpu binding of the current thread 669 */ 670 671static void 672pmc_restore_cpu_binding(struct pmc_binding *pb) 673{ 674 PMCDBG(CPU,BND,2, "restore-cpu curcpu=%d restore=%d", 675 curthread->td_oncpu, pb->pb_cpu); 676 thread_lock(curthread); 677 if (pb->pb_bound) 678 sched_bind(curthread, pb->pb_cpu); 679 else 680 sched_unbind(curthread); 681 thread_unlock(curthread); 682 PMCDBG(CPU,BND,2, "%s", "restore-cpu done"); 683} 684 685/* 686 * move execution over the specified cpu and bind it there. 687 */ 688 689static void 690pmc_select_cpu(int cpu) 691{ 692 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 693 ("[pmc,%d] bad cpu number %d", __LINE__, cpu)); 694 695 /* Never move to an inactive CPU. */ 696 KASSERT(pmc_cpu_is_active(cpu), ("[pmc,%d] selecting inactive " 697 "CPU %d", __LINE__, cpu)); 698 699 PMCDBG(CPU,SEL,2, "select-cpu cpu=%d", cpu); 700 thread_lock(curthread); 701 sched_bind(curthread, cpu); 702 thread_unlock(curthread); 703 704 KASSERT(curthread->td_oncpu == cpu, 705 ("[pmc,%d] CPU not bound [cpu=%d, curr=%d]", __LINE__, 706 cpu, curthread->td_oncpu)); 707 708 PMCDBG(CPU,SEL,2, "select-cpu cpu=%d ok", cpu); 709} 710 711/* 712 * Force a context switch. 713 * 714 * We do this by pause'ing for 1 tick -- invoking mi_switch() is not 715 * guaranteed to force a context switch. 716 */ 717 718static void 719pmc_force_context_switch(void) 720{ 721 722 pause("pmcctx", 1); 723} 724 725/* 726 * Get the file name for an executable. This is a simple wrapper 727 * around vn_fullpath(9). 728 */ 729 730static void 731pmc_getfilename(struct vnode *v, char **fullpath, char **freepath) 732{ 733 734 *fullpath = "unknown"; 735 *freepath = NULL; 736 vn_fullpath(curthread, v, fullpath, freepath); 737} 738 739/* 740 * remove an process owning PMCs 741 */ 742 743void 744pmc_remove_owner(struct pmc_owner *po) 745{ 746 struct pmc *pm, *tmp; 747 748 sx_assert(&pmc_sx, SX_XLOCKED); 749 750 PMCDBG(OWN,ORM,1, "remove-owner po=%p", po); 751 752 /* Remove descriptor from the owner hash table */ 753 LIST_REMOVE(po, po_next); 754 755 /* release all owned PMC descriptors */ 756 LIST_FOREACH_SAFE(pm, &po->po_pmcs, pm_next, tmp) { 757 PMCDBG(OWN,ORM,2, "pmc=%p", pm); 758 KASSERT(pm->pm_owner == po, 759 ("[pmc,%d] owner %p != po %p", __LINE__, pm->pm_owner, po)); 760 761 pmc_release_pmc_descriptor(pm); /* will unlink from the list */ 762 pmc_destroy_pmc_descriptor(pm); 763 } 764 765 KASSERT(po->po_sscount == 0, 766 ("[pmc,%d] SS count not zero", __LINE__)); 767 KASSERT(LIST_EMPTY(&po->po_pmcs), 768 ("[pmc,%d] PMC list not empty", __LINE__)); 769 770 /* de-configure the log file if present */ 771 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 772 pmclog_deconfigure_log(po); 773} 774 775/* 776 * remove an owner process record if all conditions are met. 777 */ 778 779static void 780pmc_maybe_remove_owner(struct pmc_owner *po) 781{ 782 783 PMCDBG(OWN,OMR,1, "maybe-remove-owner po=%p", po); 784 785 /* 786 * Remove owner record if 787 * - this process does not own any PMCs 788 * - this process has not allocated a system-wide sampling buffer 789 */ 790 791 if (LIST_EMPTY(&po->po_pmcs) && 792 ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0)) { 793 pmc_remove_owner(po); 794 pmc_destroy_owner_descriptor(po); 795 } 796} 797 798/* 799 * Add an association between a target process and a PMC. 800 */ 801 802static void 803pmc_link_target_process(struct pmc *pm, struct pmc_process *pp) 804{ 805 int ri; 806 struct pmc_target *pt; 807 808 sx_assert(&pmc_sx, SX_XLOCKED); 809 810 KASSERT(pm != NULL && pp != NULL, 811 ("[pmc,%d] Null pm %p or pp %p", __LINE__, pm, pp)); 812 KASSERT(PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)), 813 ("[pmc,%d] Attaching a non-process-virtual pmc=%p to pid=%d", 814 __LINE__, pm, pp->pp_proc->p_pid)); 815 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= ((int) md->pmd_npmc - 1), 816 ("[pmc,%d] Illegal reference count %d for process record %p", 817 __LINE__, pp->pp_refcnt, (void *) pp)); 818 819 ri = PMC_TO_ROWINDEX(pm); 820 821 PMCDBG(PRC,TLK,1, "link-target pmc=%p ri=%d pmc-process=%p", 822 pm, ri, pp); 823 824#ifdef DEBUG 825 LIST_FOREACH(pt, &pm->pm_targets, pt_next) 826 if (pt->pt_process == pp) 827 KASSERT(0, ("[pmc,%d] pp %p already in pmc %p targets", 828 __LINE__, pp, pm)); 829#endif 830 831 pt = malloc(sizeof(struct pmc_target), M_PMC, M_WAITOK|M_ZERO); 832 pt->pt_process = pp; 833 834 LIST_INSERT_HEAD(&pm->pm_targets, pt, pt_next); 835 836 atomic_store_rel_ptr((uintptr_t *)&pp->pp_pmcs[ri].pp_pmc, 837 (uintptr_t)pm); 838 839 if (pm->pm_owner->po_owner == pp->pp_proc) 840 pm->pm_flags |= PMC_F_ATTACHED_TO_OWNER; 841 842 /* 843 * Initialize the per-process values at this row index. 844 */ 845 pp->pp_pmcs[ri].pp_pmcval = PMC_TO_MODE(pm) == PMC_MODE_TS ? 846 pm->pm_sc.pm_reloadcount : 0; 847 848 pp->pp_refcnt++; 849 850} 851 852/* 853 * Removes the association between a target process and a PMC. 854 */ 855 856static void 857pmc_unlink_target_process(struct pmc *pm, struct pmc_process *pp) 858{ 859 int ri; 860 struct proc *p; 861 struct pmc_target *ptgt; 862 863 sx_assert(&pmc_sx, SX_XLOCKED); 864 865 KASSERT(pm != NULL && pp != NULL, 866 ("[pmc,%d] Null pm %p or pp %p", __LINE__, pm, pp)); 867 868 KASSERT(pp->pp_refcnt >= 1 && pp->pp_refcnt <= (int) md->pmd_npmc, 869 ("[pmc,%d] Illegal ref count %d on process record %p", 870 __LINE__, pp->pp_refcnt, (void *) pp)); 871 872 ri = PMC_TO_ROWINDEX(pm); 873 874 PMCDBG(PRC,TUL,1, "unlink-target pmc=%p ri=%d pmc-process=%p", 875 pm, ri, pp); 876 877 KASSERT(pp->pp_pmcs[ri].pp_pmc == pm, 878 ("[pmc,%d] PMC ri %d mismatch pmc %p pp->[ri] %p", __LINE__, 879 ri, pm, pp->pp_pmcs[ri].pp_pmc)); 880 881 pp->pp_pmcs[ri].pp_pmc = NULL; 882 pp->pp_pmcs[ri].pp_pmcval = (pmc_value_t) 0; 883 884 /* Remove owner-specific flags */ 885 if (pm->pm_owner->po_owner == pp->pp_proc) { 886 pp->pp_flags &= ~PMC_PP_ENABLE_MSR_ACCESS; 887 pm->pm_flags &= ~PMC_F_ATTACHED_TO_OWNER; 888 } 889 890 pp->pp_refcnt--; 891 892 /* Remove the target process from the PMC structure */ 893 LIST_FOREACH(ptgt, &pm->pm_targets, pt_next) 894 if (ptgt->pt_process == pp) 895 break; 896 897 KASSERT(ptgt != NULL, ("[pmc,%d] process %p (pp: %p) not found " 898 "in pmc %p", __LINE__, pp->pp_proc, pp, pm)); 899 900 LIST_REMOVE(ptgt, pt_next); 901 free(ptgt, M_PMC); 902 903 /* if the PMC now lacks targets, send the owner a SIGIO */ 904 if (LIST_EMPTY(&pm->pm_targets)) { 905 p = pm->pm_owner->po_owner; 906 PROC_LOCK(p); 907 kern_psignal(p, SIGIO); 908 PROC_UNLOCK(p); 909 910 PMCDBG(PRC,SIG,2, "signalling proc=%p signal=%d", p, 911 SIGIO); 912 } 913} 914 915/* 916 * Check if PMC 'pm' may be attached to target process 't'. 917 */ 918 919static int 920pmc_can_attach(struct pmc *pm, struct proc *t) 921{ 922 struct proc *o; /* pmc owner */ 923 struct ucred *oc, *tc; /* owner, target credentials */ 924 int decline_attach, i; 925 926 /* 927 * A PMC's owner can always attach that PMC to itself. 928 */ 929 930 if ((o = pm->pm_owner->po_owner) == t) 931 return 0; 932 933 PROC_LOCK(o); 934 oc = o->p_ucred; 935 crhold(oc); 936 PROC_UNLOCK(o); 937 938 PROC_LOCK(t); 939 tc = t->p_ucred; 940 crhold(tc); 941 PROC_UNLOCK(t); 942 943 /* 944 * The effective uid of the PMC owner should match at least one 945 * of the {effective,real,saved} uids of the target process. 946 */ 947 948 decline_attach = oc->cr_uid != tc->cr_uid && 949 oc->cr_uid != tc->cr_svuid && 950 oc->cr_uid != tc->cr_ruid; 951 952 /* 953 * Every one of the target's group ids, must be in the owner's 954 * group list. 955 */ 956 for (i = 0; !decline_attach && i < tc->cr_ngroups; i++) 957 decline_attach = !groupmember(tc->cr_groups[i], oc); 958 959 /* check the read and saved gids too */ 960 if (decline_attach == 0) 961 decline_attach = !groupmember(tc->cr_rgid, oc) || 962 !groupmember(tc->cr_svgid, oc); 963 964 crfree(tc); 965 crfree(oc); 966 967 return !decline_attach; 968} 969 970/* 971 * Attach a process to a PMC. 972 */ 973 974static int 975pmc_attach_one_process(struct proc *p, struct pmc *pm) 976{ 977 int ri; 978 char *fullpath, *freepath; 979 struct pmc_process *pp; 980 981 sx_assert(&pmc_sx, SX_XLOCKED); 982 983 PMCDBG(PRC,ATT,2, "attach-one pm=%p ri=%d proc=%p (%d, %s)", pm, 984 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 985 986 /* 987 * Locate the process descriptor corresponding to process 'p', 988 * allocating space as needed. 989 * 990 * Verify that rowindex 'pm_rowindex' is free in the process 991 * descriptor. 992 * 993 * If not, allocate space for a descriptor and link the 994 * process descriptor and PMC. 995 */ 996 ri = PMC_TO_ROWINDEX(pm); 997 998 if ((pp = pmc_find_process_descriptor(p, PMC_FLAG_ALLOCATE)) == NULL) 999 return ENOMEM; 1000 1001 if (pp->pp_pmcs[ri].pp_pmc == pm) /* already present at slot [ri] */ 1002 return EEXIST; 1003 1004 if (pp->pp_pmcs[ri].pp_pmc != NULL) 1005 return EBUSY; 1006 1007 pmc_link_target_process(pm, pp); 1008 1009 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)) && 1010 (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) == 0) 1011 pm->pm_flags |= PMC_F_NEEDS_LOGFILE; 1012 1013 pm->pm_flags |= PMC_F_ATTACH_DONE; /* mark as attached */ 1014 1015 /* issue an attach event to a configured log file */ 1016 if (pm->pm_owner->po_flags & PMC_PO_OWNS_LOGFILE) { 1017 pmc_getfilename(p->p_textvp, &fullpath, &freepath); 1018 if (p->p_flag & P_KTHREAD) { 1019 fullpath = kernelname; 1020 freepath = NULL; 1021 } else 1022 pmclog_process_pmcattach(pm, p->p_pid, fullpath); 1023 if (freepath) 1024 free(freepath, M_TEMP); 1025 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 1026 pmc_log_process_mappings(pm->pm_owner, p); 1027 } 1028 /* mark process as using HWPMCs */ 1029 PROC_LOCK(p); 1030 p->p_flag |= P_HWPMC; 1031 PROC_UNLOCK(p); 1032 1033 return 0; 1034} 1035 1036/* 1037 * Attach a process and optionally its children 1038 */ 1039 1040static int 1041pmc_attach_process(struct proc *p, struct pmc *pm) 1042{ 1043 int error; 1044 struct proc *top; 1045 1046 sx_assert(&pmc_sx, SX_XLOCKED); 1047 1048 PMCDBG(PRC,ATT,1, "attach pm=%p ri=%d proc=%p (%d, %s)", pm, 1049 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 1050 1051 1052 /* 1053 * If this PMC successfully allowed a GETMSR operation 1054 * in the past, disallow further ATTACHes. 1055 */ 1056 1057 if ((pm->pm_flags & PMC_PP_ENABLE_MSR_ACCESS) != 0) 1058 return EPERM; 1059 1060 if ((pm->pm_flags & PMC_F_DESCENDANTS) == 0) 1061 return pmc_attach_one_process(p, pm); 1062 1063 /* 1064 * Traverse all child processes, attaching them to 1065 * this PMC. 1066 */ 1067 1068 sx_slock(&proctree_lock); 1069 1070 top = p; 1071 1072 for (;;) { 1073 if ((error = pmc_attach_one_process(p, pm)) != 0) 1074 break; 1075 if (!LIST_EMPTY(&p->p_children)) 1076 p = LIST_FIRST(&p->p_children); 1077 else for (;;) { 1078 if (p == top) 1079 goto done; 1080 if (LIST_NEXT(p, p_sibling)) { 1081 p = LIST_NEXT(p, p_sibling); 1082 break; 1083 } 1084 p = p->p_pptr; 1085 } 1086 } 1087 1088 if (error) 1089 (void) pmc_detach_process(top, pm); 1090 1091 done: 1092 sx_sunlock(&proctree_lock); 1093 return error; 1094} 1095 1096/* 1097 * Detach a process from a PMC. If there are no other PMCs tracking 1098 * this process, remove the process structure from its hash table. If 1099 * 'flags' contains PMC_FLAG_REMOVE, then free the process structure. 1100 */ 1101 1102static int 1103pmc_detach_one_process(struct proc *p, struct pmc *pm, int flags) 1104{ 1105 int ri; 1106 struct pmc_process *pp; 1107 1108 sx_assert(&pmc_sx, SX_XLOCKED); 1109 1110 KASSERT(pm != NULL, 1111 ("[pmc,%d] null pm pointer", __LINE__)); 1112 1113 ri = PMC_TO_ROWINDEX(pm); 1114 1115 PMCDBG(PRC,ATT,2, "detach-one pm=%p ri=%d proc=%p (%d, %s) flags=0x%x", 1116 pm, ri, p, p->p_pid, p->p_comm, flags); 1117 1118 if ((pp = pmc_find_process_descriptor(p, 0)) == NULL) 1119 return ESRCH; 1120 1121 if (pp->pp_pmcs[ri].pp_pmc != pm) 1122 return EINVAL; 1123 1124 pmc_unlink_target_process(pm, pp); 1125 1126 /* Issue a detach entry if a log file is configured */ 1127 if (pm->pm_owner->po_flags & PMC_PO_OWNS_LOGFILE) 1128 pmclog_process_pmcdetach(pm, p->p_pid); 1129 1130 /* 1131 * If there are no PMCs targetting this process, we remove its 1132 * descriptor from the target hash table and unset the P_HWPMC 1133 * flag in the struct proc. 1134 */ 1135 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= (int) md->pmd_npmc, 1136 ("[pmc,%d] Illegal refcnt %d for process struct %p", 1137 __LINE__, pp->pp_refcnt, pp)); 1138 1139 if (pp->pp_refcnt != 0) /* still a target of some PMC */ 1140 return 0; 1141 1142 pmc_remove_process_descriptor(pp); 1143 1144 if (flags & PMC_FLAG_REMOVE) 1145 free(pp, M_PMC); 1146 1147 PROC_LOCK(p); 1148 p->p_flag &= ~P_HWPMC; 1149 PROC_UNLOCK(p); 1150 1151 return 0; 1152} 1153 1154/* 1155 * Detach a process and optionally its descendants from a PMC. 1156 */ 1157 1158static int 1159pmc_detach_process(struct proc *p, struct pmc *pm) 1160{ 1161 struct proc *top; 1162 1163 sx_assert(&pmc_sx, SX_XLOCKED); 1164 1165 PMCDBG(PRC,ATT,1, "detach pm=%p ri=%d proc=%p (%d, %s)", pm, 1166 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 1167 1168 if ((pm->pm_flags & PMC_F_DESCENDANTS) == 0) 1169 return pmc_detach_one_process(p, pm, PMC_FLAG_REMOVE); 1170 1171 /* 1172 * Traverse all children, detaching them from this PMC. We 1173 * ignore errors since we could be detaching a PMC from a 1174 * partially attached proc tree. 1175 */ 1176 1177 sx_slock(&proctree_lock); 1178 1179 top = p; 1180 1181 for (;;) { 1182 (void) pmc_detach_one_process(p, pm, PMC_FLAG_REMOVE); 1183 1184 if (!LIST_EMPTY(&p->p_children)) 1185 p = LIST_FIRST(&p->p_children); 1186 else for (;;) { 1187 if (p == top) 1188 goto done; 1189 if (LIST_NEXT(p, p_sibling)) { 1190 p = LIST_NEXT(p, p_sibling); 1191 break; 1192 } 1193 p = p->p_pptr; 1194 } 1195 } 1196 1197 done: 1198 sx_sunlock(&proctree_lock); 1199 1200 if (LIST_EMPTY(&pm->pm_targets)) 1201 pm->pm_flags &= ~PMC_F_ATTACH_DONE; 1202 1203 return 0; 1204} 1205 1206 1207/* 1208 * Thread context switch IN 1209 */ 1210 1211static void 1212pmc_process_csw_in(struct thread *td) 1213{ 1214 int cpu; 1215 unsigned int adjri, ri; 1216 struct pmc *pm; 1217 struct proc *p; 1218 struct pmc_cpu *pc; 1219 struct pmc_hw *phw; 1220 pmc_value_t newvalue; 1221 struct pmc_process *pp; 1222 struct pmc_classdep *pcd; 1223 1224 p = td->td_proc; 1225 1226 if ((pp = pmc_find_process_descriptor(p, PMC_FLAG_NONE)) == NULL) 1227 return; 1228 1229 KASSERT(pp->pp_proc == td->td_proc, 1230 ("[pmc,%d] not my thread state", __LINE__)); 1231 1232 critical_enter(); /* no preemption from this point */ 1233 1234 cpu = PCPU_GET(cpuid); /* td->td_oncpu is invalid */ 1235 1236 PMCDBG(CSW,SWI,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p, 1237 p->p_pid, p->p_comm, pp); 1238 1239 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 1240 ("[pmc,%d] wierd CPU id %d", __LINE__, cpu)); 1241 1242 pc = pmc_pcpu[cpu]; 1243 1244 for (ri = 0; ri < md->pmd_npmc; ri++) { 1245 1246 if ((pm = pp->pp_pmcs[ri].pp_pmc) == NULL) 1247 continue; 1248 1249 KASSERT(PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)), 1250 ("[pmc,%d] Target PMC in non-virtual mode (%d)", 1251 __LINE__, PMC_TO_MODE(pm))); 1252 1253 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 1254 ("[pmc,%d] Row index mismatch pmc %d != ri %d", 1255 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 1256 1257 /* 1258 * Only PMCs that are marked as 'RUNNING' need 1259 * be placed on hardware. 1260 */ 1261 1262 if (pm->pm_state != PMC_STATE_RUNNING) 1263 continue; 1264 1265 /* increment PMC runcount */ 1266 atomic_add_rel_int(&pm->pm_runcount, 1); 1267 1268 /* configure the HWPMC we are going to use. */ 1269 pcd = pmc_ri_to_classdep(md, ri, &adjri); 1270 pcd->pcd_config_pmc(cpu, adjri, pm); 1271 1272 phw = pc->pc_hwpmcs[ri]; 1273 1274 KASSERT(phw != NULL, 1275 ("[pmc,%d] null hw pointer", __LINE__)); 1276 1277 KASSERT(phw->phw_pmc == pm, 1278 ("[pmc,%d] hw->pmc %p != pmc %p", __LINE__, 1279 phw->phw_pmc, pm)); 1280 1281 /* 1282 * Write out saved value and start the PMC. 1283 * 1284 * Sampling PMCs use a per-process value, while 1285 * counting mode PMCs use a per-pmc value that is 1286 * inherited across descendants. 1287 */ 1288 if (PMC_TO_MODE(pm) == PMC_MODE_TS) { 1289 mtx_pool_lock_spin(pmc_mtxpool, pm); 1290 newvalue = PMC_PCPU_SAVED(cpu,ri) = 1291 pp->pp_pmcs[ri].pp_pmcval; 1292 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1293 } else { 1294 KASSERT(PMC_TO_MODE(pm) == PMC_MODE_TC, 1295 ("[pmc,%d] illegal mode=%d", __LINE__, 1296 PMC_TO_MODE(pm))); 1297 mtx_pool_lock_spin(pmc_mtxpool, pm); 1298 newvalue = PMC_PCPU_SAVED(cpu, ri) = 1299 pm->pm_gv.pm_savedvalue; 1300 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1301 } 1302 1303 PMCDBG(CSW,SWI,1,"cpu=%d ri=%d new=%jd", cpu, ri, newvalue); 1304 1305 pcd->pcd_write_pmc(cpu, adjri, newvalue); 1306 pcd->pcd_start_pmc(cpu, adjri); 1307 } 1308 1309 /* 1310 * perform any other architecture/cpu dependent thread 1311 * switch-in actions. 1312 */ 1313 1314 (void) (*md->pmd_switch_in)(pc, pp); 1315 1316 critical_exit(); 1317 1318} 1319 1320/* 1321 * Thread context switch OUT. 1322 */ 1323 1324static void 1325pmc_process_csw_out(struct thread *td) 1326{ 1327 int cpu; 1328 int64_t tmp; 1329 struct pmc *pm; 1330 struct proc *p; 1331 enum pmc_mode mode; 1332 struct pmc_cpu *pc; 1333 pmc_value_t newvalue; 1334 unsigned int adjri, ri; 1335 struct pmc_process *pp; 1336 struct pmc_classdep *pcd; 1337 1338 1339 /* 1340 * Locate our process descriptor; this may be NULL if 1341 * this process is exiting and we have already removed 1342 * the process from the target process table. 1343 * 1344 * Note that due to kernel preemption, multiple 1345 * context switches may happen while the process is 1346 * exiting. 1347 * 1348 * Note also that if the target process cannot be 1349 * found we still need to deconfigure any PMCs that 1350 * are currently running on hardware. 1351 */ 1352 1353 p = td->td_proc; 1354 pp = pmc_find_process_descriptor(p, PMC_FLAG_NONE); 1355 1356 /* 1357 * save PMCs 1358 */ 1359 1360 critical_enter(); 1361 1362 cpu = PCPU_GET(cpuid); /* td->td_oncpu is invalid */ 1363 1364 PMCDBG(CSW,SWO,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p, 1365 p->p_pid, p->p_comm, pp); 1366 1367 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 1368 ("[pmc,%d wierd CPU id %d", __LINE__, cpu)); 1369 1370 pc = pmc_pcpu[cpu]; 1371 1372 /* 1373 * When a PMC gets unlinked from a target PMC, it will 1374 * be removed from the target's pp_pmc[] array. 1375 * 1376 * However, on a MP system, the target could have been 1377 * executing on another CPU at the time of the unlink. 1378 * So, at context switch OUT time, we need to look at 1379 * the hardware to determine if a PMC is scheduled on 1380 * it. 1381 */ 1382 1383 for (ri = 0; ri < md->pmd_npmc; ri++) { 1384 1385 pcd = pmc_ri_to_classdep(md, ri, &adjri); 1386 pm = NULL; 1387 (void) (*pcd->pcd_get_config)(cpu, adjri, &pm); 1388 1389 if (pm == NULL) /* nothing at this row index */ 1390 continue; 1391 1392 mode = PMC_TO_MODE(pm); 1393 if (!PMC_IS_VIRTUAL_MODE(mode)) 1394 continue; /* not a process virtual PMC */ 1395 1396 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 1397 ("[pmc,%d] ri mismatch pmc(%d) ri(%d)", 1398 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 1399 1400 /* Stop hardware if not already stopped */ 1401 if (pm->pm_stalled == 0) 1402 pcd->pcd_stop_pmc(cpu, adjri); 1403 1404 /* reduce this PMC's runcount */ 1405 atomic_subtract_rel_int(&pm->pm_runcount, 1); 1406 1407 /* 1408 * If this PMC is associated with this process, 1409 * save the reading. 1410 */ 1411 1412 if (pp != NULL && pp->pp_pmcs[ri].pp_pmc != NULL) { 1413 1414 KASSERT(pm == pp->pp_pmcs[ri].pp_pmc, 1415 ("[pmc,%d] pm %p != pp_pmcs[%d] %p", __LINE__, 1416 pm, ri, pp->pp_pmcs[ri].pp_pmc)); 1417 1418 KASSERT(pp->pp_refcnt > 0, 1419 ("[pmc,%d] pp refcnt = %d", __LINE__, 1420 pp->pp_refcnt)); 1421 1422 pcd->pcd_read_pmc(cpu, adjri, &newvalue); 1423 1424 tmp = newvalue - PMC_PCPU_SAVED(cpu,ri); 1425 1426 PMCDBG(CSW,SWO,1,"cpu=%d ri=%d tmp=%jd", cpu, ri, 1427 tmp); 1428 1429 if (mode == PMC_MODE_TS) { 1430 1431 /* 1432 * For sampling process-virtual PMCs, 1433 * we expect the count to be 1434 * decreasing as the 'value' 1435 * programmed into the PMC is the 1436 * number of events to be seen till 1437 * the next sampling interrupt. 1438 */ 1439 if (tmp < 0) 1440 tmp += pm->pm_sc.pm_reloadcount; 1441 mtx_pool_lock_spin(pmc_mtxpool, pm); 1442 pp->pp_pmcs[ri].pp_pmcval -= tmp; 1443 if ((int64_t) pp->pp_pmcs[ri].pp_pmcval < 0) 1444 pp->pp_pmcs[ri].pp_pmcval += 1445 pm->pm_sc.pm_reloadcount; 1446 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1447 1448 } else { 1449 1450 /* 1451 * For counting process-virtual PMCs, 1452 * we expect the count to be 1453 * increasing monotonically, modulo a 64 1454 * bit wraparound. 1455 */ 1456 KASSERT((int64_t) tmp >= 0, 1457 ("[pmc,%d] negative increment cpu=%d " 1458 "ri=%d newvalue=%jx saved=%jx " 1459 "incr=%jx", __LINE__, cpu, ri, 1460 newvalue, PMC_PCPU_SAVED(cpu,ri), tmp)); 1461 1462 mtx_pool_lock_spin(pmc_mtxpool, pm); 1463 pm->pm_gv.pm_savedvalue += tmp; 1464 pp->pp_pmcs[ri].pp_pmcval += tmp; 1465 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1466 1467 if (pm->pm_flags & PMC_F_LOG_PROCCSW) 1468 pmclog_process_proccsw(pm, pp, tmp); 1469 } 1470 } 1471 1472 /* mark hardware as free */ 1473 pcd->pcd_config_pmc(cpu, adjri, NULL); 1474 } 1475 1476 /* 1477 * perform any other architecture/cpu dependent thread 1478 * switch out functions. 1479 */ 1480 1481 (void) (*md->pmd_switch_out)(pc, pp); 1482 1483 critical_exit(); 1484} 1485 1486/* 1487 * A mapping change for a process. 1488 */ 1489 1490static void 1491pmc_process_mmap(struct thread *td, struct pmckern_map_in *pkm) 1492{ 1493 int ri; 1494 pid_t pid; 1495 char *fullpath, *freepath; 1496 const struct pmc *pm; 1497 struct pmc_owner *po; 1498 const struct pmc_process *pp; 1499 1500 freepath = fullpath = NULL; 1501 pmc_getfilename((struct vnode *) pkm->pm_file, &fullpath, &freepath); 1502 1503 pid = td->td_proc->p_pid; 1504 1505 /* Inform owners of all system-wide sampling PMCs. */ 1506 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1507 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1508 pmclog_process_map_in(po, pid, pkm->pm_address, fullpath); 1509 1510 if ((pp = pmc_find_process_descriptor(td->td_proc, 0)) == NULL) 1511 goto done; 1512 1513 /* 1514 * Inform sampling PMC owners tracking this process. 1515 */ 1516 for (ri = 0; ri < md->pmd_npmc; ri++) 1517 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL && 1518 PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 1519 pmclog_process_map_in(pm->pm_owner, 1520 pid, pkm->pm_address, fullpath); 1521 1522 done: 1523 if (freepath) 1524 free(freepath, M_TEMP); 1525} 1526 1527 1528/* 1529 * Log an munmap request. 1530 */ 1531 1532static void 1533pmc_process_munmap(struct thread *td, struct pmckern_map_out *pkm) 1534{ 1535 int ri; 1536 pid_t pid; 1537 struct pmc_owner *po; 1538 const struct pmc *pm; 1539 const struct pmc_process *pp; 1540 1541 pid = td->td_proc->p_pid; 1542 1543 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1544 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1545 pmclog_process_map_out(po, pid, pkm->pm_address, 1546 pkm->pm_address + pkm->pm_size); 1547 1548 if ((pp = pmc_find_process_descriptor(td->td_proc, 0)) == NULL) 1549 return; 1550 1551 for (ri = 0; ri < md->pmd_npmc; ri++) 1552 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL && 1553 PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 1554 pmclog_process_map_out(pm->pm_owner, pid, 1555 pkm->pm_address, pkm->pm_address + pkm->pm_size); 1556} 1557 1558/* 1559 * Log mapping information about the kernel. 1560 */ 1561 1562static void 1563pmc_log_kernel_mappings(struct pmc *pm) 1564{ 1565 struct pmc_owner *po; 1566 struct pmckern_map_in *km, *kmbase; 1567 1568 sx_assert(&pmc_sx, SX_LOCKED); 1569 KASSERT(PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)), 1570 ("[pmc,%d] non-sampling PMC (%p) desires mapping information", 1571 __LINE__, (void *) pm)); 1572 1573 po = pm->pm_owner; 1574 1575 if (po->po_flags & PMC_PO_INITIAL_MAPPINGS_DONE) 1576 return; 1577 1578 /* 1579 * Log the current set of kernel modules. 1580 */ 1581 kmbase = linker_hwpmc_list_objects(); 1582 for (km = kmbase; km->pm_file != NULL; km++) { 1583 PMCDBG(LOG,REG,1,"%s %p", (char *) km->pm_file, 1584 (void *) km->pm_address); 1585 pmclog_process_map_in(po, (pid_t) -1, km->pm_address, 1586 km->pm_file); 1587 } 1588 free(kmbase, M_LINKER); 1589 1590 po->po_flags |= PMC_PO_INITIAL_MAPPINGS_DONE; 1591} 1592 1593/* 1594 * Log the mappings for a single process. 1595 */ 1596 1597static void 1598pmc_log_process_mappings(struct pmc_owner *po, struct proc *p) 1599{ 1600 vm_map_t map; 1601 struct vnode *vp; 1602 struct vmspace *vm; 1603 vm_map_entry_t entry; 1604 vm_offset_t last_end; 1605 u_int last_timestamp; 1606 struct vnode *last_vp; 1607 vm_offset_t start_addr; 1608 vm_object_t obj, lobj, tobj; 1609 char *fullpath, *freepath; 1610 1611 last_vp = NULL; 1612 last_end = (vm_offset_t) 0; 1613 fullpath = freepath = NULL; 1614 1615 if ((vm = vmspace_acquire_ref(p)) == NULL) 1616 return; 1617 1618 map = &vm->vm_map; 1619 vm_map_lock_read(map); 1620 1621 for (entry = map->header.next; entry != &map->header; entry = entry->next) { 1622 1623 if (entry == NULL) { 1624 PMCDBG(LOG,OPS,2, "hwpmc: vm_map entry unexpectedly " 1625 "NULL! pid=%d vm_map=%p\n", p->p_pid, map); 1626 break; 1627 } 1628 1629 /* 1630 * We only care about executable map entries. 1631 */ 1632 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) || 1633 !(entry->protection & VM_PROT_EXECUTE) || 1634 (entry->object.vm_object == NULL)) { 1635 continue; 1636 } 1637 1638 obj = entry->object.vm_object; 1639 VM_OBJECT_RLOCK(obj); 1640 1641 /* 1642 * Walk the backing_object list to find the base 1643 * (non-shadowed) vm_object. 1644 */ 1645 for (lobj = tobj = obj; tobj != NULL; tobj = tobj->backing_object) { 1646 if (tobj != obj) 1647 VM_OBJECT_RLOCK(tobj); 1648 if (lobj != obj) 1649 VM_OBJECT_RUNLOCK(lobj); 1650 lobj = tobj; 1651 } 1652 1653 /* 1654 * At this point lobj is the base vm_object and it is locked. 1655 */ 1656 if (lobj == NULL) { 1657 PMCDBG(LOG,OPS,2, "hwpmc: lobj unexpectedly NULL! pid=%d " 1658 "vm_map=%p vm_obj=%p\n", p->p_pid, map, obj); 1659 VM_OBJECT_RUNLOCK(obj); 1660 continue; 1661 } 1662 1663 if (lobj->type != OBJT_VNODE || lobj->handle == NULL) { 1664 if (lobj != obj) 1665 VM_OBJECT_RUNLOCK(lobj); 1666 VM_OBJECT_RUNLOCK(obj); 1667 continue; 1668 } 1669 1670 /* 1671 * Skip contiguous regions that point to the same 1672 * vnode, so we don't emit redundant MAP-IN 1673 * directives. 1674 */ 1675 if (entry->start == last_end && lobj->handle == last_vp) { 1676 last_end = entry->end; 1677 if (lobj != obj) 1678 VM_OBJECT_RUNLOCK(lobj); 1679 VM_OBJECT_RUNLOCK(obj); 1680 continue; 1681 } 1682 1683 /* 1684 * We don't want to keep the proc's vm_map or this 1685 * vm_object locked while we walk the pathname, since 1686 * vn_fullpath() can sleep. However, if we drop the 1687 * lock, it's possible for concurrent activity to 1688 * modify the vm_map list. To protect against this, 1689 * we save the vm_map timestamp before we release the 1690 * lock, and check it after we reacquire the lock 1691 * below. 1692 */ 1693 start_addr = entry->start; 1694 last_end = entry->end; 1695 last_timestamp = map->timestamp; 1696 vm_map_unlock_read(map); 1697 1698 vp = lobj->handle; 1699 vref(vp); 1700 if (lobj != obj) 1701 VM_OBJECT_RUNLOCK(lobj); 1702 1703 VM_OBJECT_RUNLOCK(obj); 1704 1705 freepath = NULL; 1706 pmc_getfilename(vp, &fullpath, &freepath); 1707 last_vp = vp; 1708 1709 vrele(vp); 1710 1711 vp = NULL; 1712 pmclog_process_map_in(po, p->p_pid, start_addr, fullpath); 1713 if (freepath) 1714 free(freepath, M_TEMP); 1715 1716 vm_map_lock_read(map); 1717 1718 /* 1719 * If our saved timestamp doesn't match, this means 1720 * that the vm_map was modified out from under us and 1721 * we can't trust our current "entry" pointer. Do a 1722 * new lookup for this entry. If there is no entry 1723 * for this address range, vm_map_lookup_entry() will 1724 * return the previous one, so we always want to go to 1725 * entry->next on the next loop iteration. 1726 * 1727 * There is an edge condition here that can occur if 1728 * there is no entry at or before this address. In 1729 * this situation, vm_map_lookup_entry returns 1730 * &map->header, which would cause our loop to abort 1731 * without processing the rest of the map. However, 1732 * in practice this will never happen for process 1733 * vm_map. This is because the executable's text 1734 * segment is the first mapping in the proc's address 1735 * space, and this mapping is never removed until the 1736 * process exits, so there will always be a non-header 1737 * entry at or before the requested address for 1738 * vm_map_lookup_entry to return. 1739 */ 1740 if (map->timestamp != last_timestamp) 1741 vm_map_lookup_entry(map, last_end - 1, &entry); 1742 } 1743 1744 vm_map_unlock_read(map); 1745 vmspace_free(vm); 1746 return; 1747} 1748 1749/* 1750 * Log mappings for all processes in the system. 1751 */ 1752 1753static void 1754pmc_log_all_process_mappings(struct pmc_owner *po) 1755{ 1756 struct proc *p, *top; 1757 1758 sx_assert(&pmc_sx, SX_XLOCKED); 1759 1760 if ((p = pfind(1)) == NULL) 1761 panic("[pmc,%d] Cannot find init", __LINE__); 1762 1763 PROC_UNLOCK(p); 1764 1765 sx_slock(&proctree_lock); 1766 1767 top = p; 1768 1769 for (;;) { 1770 pmc_log_process_mappings(po, p); 1771 if (!LIST_EMPTY(&p->p_children)) 1772 p = LIST_FIRST(&p->p_children); 1773 else for (;;) { 1774 if (p == top) 1775 goto done; 1776 if (LIST_NEXT(p, p_sibling)) { 1777 p = LIST_NEXT(p, p_sibling); 1778 break; 1779 } 1780 p = p->p_pptr; 1781 } 1782 } 1783 done: 1784 sx_sunlock(&proctree_lock); 1785} 1786 1787/* 1788 * The 'hook' invoked from the kernel proper 1789 */ 1790 1791 1792#ifdef DEBUG 1793const char *pmc_hooknames[] = { 1794 /* these strings correspond to PMC_FN_* in <sys/pmckern.h> */ 1795 "", 1796 "EXEC", 1797 "CSW-IN", 1798 "CSW-OUT", 1799 "SAMPLE", 1800 "UNUSED1", 1801 "UNUSED2", 1802 "MMAP", 1803 "MUNMAP", 1804 "CALLCHAIN-NMI", 1805 "CALLCHAIN-SOFT", 1806 "SOFTSAMPLING" 1807}; 1808#endif 1809 1810static int 1811pmc_hook_handler(struct thread *td, int function, void *arg) 1812{ 1813 1814 PMCDBG(MOD,PMH,1, "hook td=%p func=%d \"%s\" arg=%p", td, function, 1815 pmc_hooknames[function], arg); 1816 1817 switch (function) 1818 { 1819 1820 /* 1821 * Process exec() 1822 */ 1823 1824 case PMC_FN_PROCESS_EXEC: 1825 { 1826 char *fullpath, *freepath; 1827 unsigned int ri; 1828 int is_using_hwpmcs; 1829 struct pmc *pm; 1830 struct proc *p; 1831 struct pmc_owner *po; 1832 struct pmc_process *pp; 1833 struct pmckern_procexec *pk; 1834 1835 sx_assert(&pmc_sx, SX_XLOCKED); 1836 1837 p = td->td_proc; 1838 pmc_getfilename(p->p_textvp, &fullpath, &freepath); 1839 1840 pk = (struct pmckern_procexec *) arg; 1841 1842 /* Inform owners of SS mode PMCs of the exec event. */ 1843 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1844 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1845 pmclog_process_procexec(po, PMC_ID_INVALID, 1846 p->p_pid, pk->pm_entryaddr, fullpath); 1847 1848 PROC_LOCK(p); 1849 is_using_hwpmcs = p->p_flag & P_HWPMC; 1850 PROC_UNLOCK(p); 1851 1852 if (!is_using_hwpmcs) { 1853 if (freepath) 1854 free(freepath, M_TEMP); 1855 break; 1856 } 1857 1858 /* 1859 * PMCs are not inherited across an exec(): remove any 1860 * PMCs that this process is the owner of. 1861 */ 1862 1863 if ((po = pmc_find_owner_descriptor(p)) != NULL) { 1864 pmc_remove_owner(po); 1865 pmc_destroy_owner_descriptor(po); 1866 } 1867 1868 /* 1869 * If the process being exec'ed is not the target of any 1870 * PMC, we are done. 1871 */ 1872 if ((pp = pmc_find_process_descriptor(p, 0)) == NULL) { 1873 if (freepath) 1874 free(freepath, M_TEMP); 1875 break; 1876 } 1877 1878 /* 1879 * Log the exec event to all monitoring owners. Skip 1880 * owners who have already recieved the event because 1881 * they had system sampling PMCs active. 1882 */ 1883 for (ri = 0; ri < md->pmd_npmc; ri++) 1884 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) { 1885 po = pm->pm_owner; 1886 if (po->po_sscount == 0 && 1887 po->po_flags & PMC_PO_OWNS_LOGFILE) 1888 pmclog_process_procexec(po, pm->pm_id, 1889 p->p_pid, pk->pm_entryaddr, 1890 fullpath); 1891 } 1892 1893 if (freepath) 1894 free(freepath, M_TEMP); 1895 1896 1897 PMCDBG(PRC,EXC,1, "exec proc=%p (%d, %s) cred-changed=%d", 1898 p, p->p_pid, p->p_comm, pk->pm_credentialschanged); 1899 1900 if (pk->pm_credentialschanged == 0) /* no change */ 1901 break; 1902 1903 /* 1904 * If the newly exec()'ed process has a different credential 1905 * than before, allow it to be the target of a PMC only if 1906 * the PMC's owner has sufficient priviledge. 1907 */ 1908 1909 for (ri = 0; ri < md->pmd_npmc; ri++) 1910 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) 1911 if (pmc_can_attach(pm, td->td_proc) != 0) 1912 pmc_detach_one_process(td->td_proc, 1913 pm, PMC_FLAG_NONE); 1914 1915 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= (int) md->pmd_npmc, 1916 ("[pmc,%d] Illegal ref count %d on pp %p", __LINE__, 1917 pp->pp_refcnt, pp)); 1918 1919 /* 1920 * If this process is no longer the target of any 1921 * PMCs, we can remove the process entry and free 1922 * up space. 1923 */ 1924 1925 if (pp->pp_refcnt == 0) { 1926 pmc_remove_process_descriptor(pp); 1927 free(pp, M_PMC); 1928 break; 1929 } 1930 1931 } 1932 break; 1933 1934 case PMC_FN_CSW_IN: 1935 pmc_process_csw_in(td); 1936 break; 1937 1938 case PMC_FN_CSW_OUT: 1939 pmc_process_csw_out(td); 1940 break; 1941 1942 /* 1943 * Process accumulated PC samples. 1944 * 1945 * This function is expected to be called by hardclock() for 1946 * each CPU that has accumulated PC samples. 1947 * 1948 * This function is to be executed on the CPU whose samples 1949 * are being processed. 1950 */ 1951 case PMC_FN_DO_SAMPLES: 1952 1953 /* 1954 * Clear the cpu specific bit in the CPU mask before 1955 * do the rest of the processing. If the NMI handler 1956 * gets invoked after the "atomic_clear_int()" call 1957 * below but before "pmc_process_samples()" gets 1958 * around to processing the interrupt, then we will 1959 * come back here at the next hardclock() tick (and 1960 * may find nothing to do if "pmc_process_samples()" 1961 * had already processed the interrupt). We don't 1962 * lose the interrupt sample. 1963 */ 1964 CPU_CLR_ATOMIC(PCPU_GET(cpuid), &pmc_cpumask); 1965 pmc_process_samples(PCPU_GET(cpuid), PMC_HR); 1966 pmc_process_samples(PCPU_GET(cpuid), PMC_SR); 1967 break; 1968 1969 case PMC_FN_MMAP: 1970 sx_assert(&pmc_sx, SX_LOCKED); 1971 pmc_process_mmap(td, (struct pmckern_map_in *) arg); 1972 break; 1973 1974 case PMC_FN_MUNMAP: 1975 sx_assert(&pmc_sx, SX_LOCKED); 1976 pmc_process_munmap(td, (struct pmckern_map_out *) arg); 1977 break; 1978 1979 case PMC_FN_USER_CALLCHAIN: 1980 /* 1981 * Record a call chain. 1982 */ 1983 KASSERT(td == curthread, ("[pmc,%d] td != curthread", 1984 __LINE__)); 1985 1986 pmc_capture_user_callchain(PCPU_GET(cpuid), PMC_HR, 1987 (struct trapframe *) arg); 1988 td->td_pflags &= ~TDP_CALLCHAIN; 1989 break; 1990 1991 case PMC_FN_USER_CALLCHAIN_SOFT: 1992 /* 1993 * Record a call chain. 1994 */ 1995 KASSERT(td == curthread, ("[pmc,%d] td != curthread", 1996 __LINE__)); 1997 pmc_capture_user_callchain(PCPU_GET(cpuid), PMC_SR, 1998 (struct trapframe *) arg); 1999 td->td_pflags &= ~TDP_CALLCHAIN; 2000 break; 2001 2002 case PMC_FN_SOFT_SAMPLING: 2003 /* 2004 * Call soft PMC sampling intr. 2005 */ 2006 pmc_soft_intr((struct pmckern_soft *) arg); 2007 break; 2008 2009 default: 2010#ifdef DEBUG 2011 KASSERT(0, ("[pmc,%d] unknown hook %d\n", __LINE__, function)); 2012#endif 2013 break; 2014 2015 } 2016 2017 return 0; 2018} 2019 2020/* 2021 * allocate a 'struct pmc_owner' descriptor in the owner hash table. 2022 */ 2023 2024static struct pmc_owner * 2025pmc_allocate_owner_descriptor(struct proc *p) 2026{ 2027 uint32_t hindex; 2028 struct pmc_owner *po; 2029 struct pmc_ownerhash *poh; 2030 2031 hindex = PMC_HASH_PTR(p, pmc_ownerhashmask); 2032 poh = &pmc_ownerhash[hindex]; 2033 2034 /* allocate space for N pointers and one descriptor struct */ 2035 po = malloc(sizeof(struct pmc_owner), M_PMC, M_WAITOK|M_ZERO); 2036 po->po_owner = p; 2037 LIST_INSERT_HEAD(poh, po, po_next); /* insert into hash table */ 2038 2039 TAILQ_INIT(&po->po_logbuffers); 2040 mtx_init(&po->po_mtx, "pmc-owner-mtx", "pmc-per-proc", MTX_SPIN); 2041 2042 PMCDBG(OWN,ALL,1, "allocate-owner proc=%p (%d, %s) pmc-owner=%p", 2043 p, p->p_pid, p->p_comm, po); 2044 2045 return po; 2046} 2047 2048static void 2049pmc_destroy_owner_descriptor(struct pmc_owner *po) 2050{ 2051 2052 PMCDBG(OWN,REL,1, "destroy-owner po=%p proc=%p (%d, %s)", 2053 po, po->po_owner, po->po_owner->p_pid, po->po_owner->p_comm); 2054 2055 mtx_destroy(&po->po_mtx); 2056 free(po, M_PMC); 2057} 2058 2059/* 2060 * find the descriptor corresponding to process 'p', adding or removing it 2061 * as specified by 'mode'. 2062 */ 2063 2064static struct pmc_process * 2065pmc_find_process_descriptor(struct proc *p, uint32_t mode) 2066{ 2067 uint32_t hindex; 2068 struct pmc_process *pp, *ppnew; 2069 struct pmc_processhash *pph; 2070 2071 hindex = PMC_HASH_PTR(p, pmc_processhashmask); 2072 pph = &pmc_processhash[hindex]; 2073 2074 ppnew = NULL; 2075 2076 /* 2077 * Pre-allocate memory in the FIND_ALLOCATE case since we 2078 * cannot call malloc(9) once we hold a spin lock. 2079 */ 2080 if (mode & PMC_FLAG_ALLOCATE) 2081 ppnew = malloc(sizeof(struct pmc_process) + md->pmd_npmc * 2082 sizeof(struct pmc_targetstate), M_PMC, M_WAITOK|M_ZERO); 2083 2084 mtx_lock_spin(&pmc_processhash_mtx); 2085 LIST_FOREACH(pp, pph, pp_next) 2086 if (pp->pp_proc == p) 2087 break; 2088 2089 if ((mode & PMC_FLAG_REMOVE) && pp != NULL) 2090 LIST_REMOVE(pp, pp_next); 2091 2092 if ((mode & PMC_FLAG_ALLOCATE) && pp == NULL && 2093 ppnew != NULL) { 2094 ppnew->pp_proc = p; 2095 LIST_INSERT_HEAD(pph, ppnew, pp_next); 2096 pp = ppnew; 2097 ppnew = NULL; 2098 } 2099 mtx_unlock_spin(&pmc_processhash_mtx); 2100 2101 if (pp != NULL && ppnew != NULL) 2102 free(ppnew, M_PMC); 2103 2104 return pp; 2105} 2106 2107/* 2108 * remove a process descriptor from the process hash table. 2109 */ 2110 2111static void 2112pmc_remove_process_descriptor(struct pmc_process *pp) 2113{ 2114 KASSERT(pp->pp_refcnt == 0, 2115 ("[pmc,%d] Removing process descriptor %p with count %d", 2116 __LINE__, pp, pp->pp_refcnt)); 2117 2118 mtx_lock_spin(&pmc_processhash_mtx); 2119 LIST_REMOVE(pp, pp_next); 2120 mtx_unlock_spin(&pmc_processhash_mtx); 2121} 2122 2123 2124/* 2125 * find an owner descriptor corresponding to proc 'p' 2126 */ 2127 2128static struct pmc_owner * 2129pmc_find_owner_descriptor(struct proc *p) 2130{ 2131 uint32_t hindex; 2132 struct pmc_owner *po; 2133 struct pmc_ownerhash *poh; 2134 2135 hindex = PMC_HASH_PTR(p, pmc_ownerhashmask); 2136 poh = &pmc_ownerhash[hindex]; 2137 2138 po = NULL; 2139 LIST_FOREACH(po, poh, po_next) 2140 if (po->po_owner == p) 2141 break; 2142 2143 PMCDBG(OWN,FND,1, "find-owner proc=%p (%d, %s) hindex=0x%x -> " 2144 "pmc-owner=%p", p, p->p_pid, p->p_comm, hindex, po); 2145 2146 return po; 2147} 2148 2149/* 2150 * pmc_allocate_pmc_descriptor 2151 * 2152 * Allocate a pmc descriptor and initialize its 2153 * fields. 2154 */ 2155 2156static struct pmc * 2157pmc_allocate_pmc_descriptor(void) 2158{ 2159 struct pmc *pmc; 2160 2161 pmc = malloc(sizeof(struct pmc), M_PMC, M_WAITOK|M_ZERO); 2162 2163 PMCDBG(PMC,ALL,1, "allocate-pmc -> pmc=%p", pmc); 2164 2165 return pmc; 2166} 2167 2168/* 2169 * Destroy a pmc descriptor. 2170 */ 2171 2172static void 2173pmc_destroy_pmc_descriptor(struct pmc *pm) 2174{ 2175 2176 KASSERT(pm->pm_state == PMC_STATE_DELETED || 2177 pm->pm_state == PMC_STATE_FREE, 2178 ("[pmc,%d] destroying non-deleted PMC", __LINE__)); 2179 KASSERT(LIST_EMPTY(&pm->pm_targets), 2180 ("[pmc,%d] destroying pmc with targets", __LINE__)); 2181 KASSERT(pm->pm_owner == NULL, 2182 ("[pmc,%d] destroying pmc attached to an owner", __LINE__)); 2183 KASSERT(pm->pm_runcount == 0, 2184 ("[pmc,%d] pmc has non-zero run count %d", __LINE__, 2185 pm->pm_runcount)); 2186 2187 free(pm, M_PMC); 2188} 2189 2190static void 2191pmc_wait_for_pmc_idle(struct pmc *pm) 2192{ 2193#ifdef DEBUG 2194 volatile int maxloop; 2195 2196 maxloop = 100 * pmc_cpu_max(); 2197#endif 2198 /* 2199 * Loop (with a forced context switch) till the PMC's runcount 2200 * comes down to zero. 2201 */ 2202 while (atomic_load_acq_32(&pm->pm_runcount) > 0) { 2203#ifdef DEBUG 2204 maxloop--; 2205 KASSERT(maxloop > 0, 2206 ("[pmc,%d] (ri%d, rc%d) waiting too long for " 2207 "pmc to be free", __LINE__, 2208 PMC_TO_ROWINDEX(pm), pm->pm_runcount)); 2209#endif 2210 pmc_force_context_switch(); 2211 } 2212} 2213 2214/* 2215 * This function does the following things: 2216 * 2217 * - detaches the PMC from hardware 2218 * - unlinks all target threads that were attached to it 2219 * - removes the PMC from its owner's list 2220 * - destroys the PMC private mutex 2221 * 2222 * Once this function completes, the given pmc pointer can be freed by 2223 * calling pmc_destroy_pmc_descriptor(). 2224 */ 2225 2226static void 2227pmc_release_pmc_descriptor(struct pmc *pm) 2228{ 2229 enum pmc_mode mode; 2230 struct pmc_hw *phw; 2231 u_int adjri, ri, cpu; 2232 struct pmc_owner *po; 2233 struct pmc_binding pb; 2234 struct pmc_process *pp; 2235 struct pmc_classdep *pcd; 2236 struct pmc_target *ptgt, *tmp; 2237 2238 sx_assert(&pmc_sx, SX_XLOCKED); 2239 2240 KASSERT(pm, ("[pmc,%d] null pmc", __LINE__)); 2241 2242 ri = PMC_TO_ROWINDEX(pm); 2243 pcd = pmc_ri_to_classdep(md, ri, &adjri); 2244 mode = PMC_TO_MODE(pm); 2245 2246 PMCDBG(PMC,REL,1, "release-pmc pmc=%p ri=%d mode=%d", pm, ri, 2247 mode); 2248 2249 /* 2250 * First, we take the PMC off hardware. 2251 */ 2252 cpu = 0; 2253 if (PMC_IS_SYSTEM_MODE(mode)) { 2254 2255 /* 2256 * A system mode PMC runs on a specific CPU. Switch 2257 * to this CPU and turn hardware off. 2258 */ 2259 pmc_save_cpu_binding(&pb); 2260 2261 cpu = PMC_TO_CPU(pm); 2262 2263 pmc_select_cpu(cpu); 2264 2265 /* switch off non-stalled CPUs */ 2266 if (pm->pm_state == PMC_STATE_RUNNING && 2267 pm->pm_stalled == 0) { 2268 2269 phw = pmc_pcpu[cpu]->pc_hwpmcs[ri]; 2270 2271 KASSERT(phw->phw_pmc == pm, 2272 ("[pmc, %d] pmc ptr ri(%d) hw(%p) pm(%p)", 2273 __LINE__, ri, phw->phw_pmc, pm)); 2274 PMCDBG(PMC,REL,2, "stopping cpu=%d ri=%d", cpu, ri); 2275 2276 critical_enter(); 2277 pcd->pcd_stop_pmc(cpu, adjri); 2278 critical_exit(); 2279 } 2280 2281 PMCDBG(PMC,REL,2, "decfg cpu=%d ri=%d", cpu, ri); 2282 2283 critical_enter(); 2284 pcd->pcd_config_pmc(cpu, adjri, NULL); 2285 critical_exit(); 2286 2287 /* adjust the global and process count of SS mode PMCs */ 2288 if (mode == PMC_MODE_SS && pm->pm_state == PMC_STATE_RUNNING) { 2289 po = pm->pm_owner; 2290 po->po_sscount--; 2291 if (po->po_sscount == 0) { 2292 atomic_subtract_rel_int(&pmc_ss_count, 1); 2293 LIST_REMOVE(po, po_ssnext); 2294 } 2295 } 2296 2297 pm->pm_state = PMC_STATE_DELETED; 2298 2299 pmc_restore_cpu_binding(&pb); 2300 2301 /* 2302 * We could have references to this PMC structure in 2303 * the per-cpu sample queues. Wait for the queue to 2304 * drain. 2305 */ 2306 pmc_wait_for_pmc_idle(pm); 2307 2308 } else if (PMC_IS_VIRTUAL_MODE(mode)) { 2309 2310 /* 2311 * A virtual PMC could be running on multiple CPUs at 2312 * a given instant. 2313 * 2314 * By marking its state as DELETED, we ensure that 2315 * this PMC is never further scheduled on hardware. 2316 * 2317 * Then we wait till all CPUs are done with this PMC. 2318 */ 2319 pm->pm_state = PMC_STATE_DELETED; 2320 2321 2322 /* Wait for the PMCs runcount to come to zero. */ 2323 pmc_wait_for_pmc_idle(pm); 2324 2325 /* 2326 * At this point the PMC is off all CPUs and cannot be 2327 * freshly scheduled onto a CPU. It is now safe to 2328 * unlink all targets from this PMC. If a 2329 * process-record's refcount falls to zero, we remove 2330 * it from the hash table. The module-wide SX lock 2331 * protects us from races. 2332 */ 2333 LIST_FOREACH_SAFE(ptgt, &pm->pm_targets, pt_next, tmp) { 2334 pp = ptgt->pt_process; 2335 pmc_unlink_target_process(pm, pp); /* frees 'ptgt' */ 2336 2337 PMCDBG(PMC,REL,3, "pp->refcnt=%d", pp->pp_refcnt); 2338 2339 /* 2340 * If the target process record shows that no 2341 * PMCs are attached to it, reclaim its space. 2342 */ 2343 2344 if (pp->pp_refcnt == 0) { 2345 pmc_remove_process_descriptor(pp); 2346 free(pp, M_PMC); 2347 } 2348 } 2349 2350 cpu = curthread->td_oncpu; /* setup cpu for pmd_release() */ 2351 2352 } 2353 2354 /* 2355 * Release any MD resources 2356 */ 2357 (void) pcd->pcd_release_pmc(cpu, adjri, pm); 2358 2359 /* 2360 * Update row disposition 2361 */ 2362 2363 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) 2364 PMC_UNMARK_ROW_STANDALONE(ri); 2365 else 2366 PMC_UNMARK_ROW_THREAD(ri); 2367 2368 /* unlink from the owner's list */ 2369 if (pm->pm_owner) { 2370 LIST_REMOVE(pm, pm_next); 2371 pm->pm_owner = NULL; 2372 } 2373} 2374 2375/* 2376 * Register an owner and a pmc. 2377 */ 2378 2379static int 2380pmc_register_owner(struct proc *p, struct pmc *pmc) 2381{ 2382 struct pmc_owner *po; 2383 2384 sx_assert(&pmc_sx, SX_XLOCKED); 2385 2386 if ((po = pmc_find_owner_descriptor(p)) == NULL) 2387 if ((po = pmc_allocate_owner_descriptor(p)) == NULL) 2388 return ENOMEM; 2389 2390 KASSERT(pmc->pm_owner == NULL, 2391 ("[pmc,%d] attempting to own an initialized PMC", __LINE__)); 2392 pmc->pm_owner = po; 2393 2394 LIST_INSERT_HEAD(&po->po_pmcs, pmc, pm_next); 2395 2396 PROC_LOCK(p); 2397 p->p_flag |= P_HWPMC; 2398 PROC_UNLOCK(p); 2399 2400 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 2401 pmclog_process_pmcallocate(pmc); 2402 2403 PMCDBG(PMC,REG,1, "register-owner pmc-owner=%p pmc=%p", 2404 po, pmc); 2405 2406 return 0; 2407} 2408 2409/* 2410 * Return the current row disposition: 2411 * == 0 => FREE 2412 * > 0 => PROCESS MODE 2413 * < 0 => SYSTEM MODE 2414 */ 2415 2416int 2417pmc_getrowdisp(int ri) 2418{ 2419 return pmc_pmcdisp[ri]; 2420} 2421 2422/* 2423 * Check if a PMC at row index 'ri' can be allocated to the current 2424 * process. 2425 * 2426 * Allocation can fail if: 2427 * - the current process is already being profiled by a PMC at index 'ri', 2428 * attached to it via OP_PMCATTACH. 2429 * - the current process has already allocated a PMC at index 'ri' 2430 * via OP_ALLOCATE. 2431 */ 2432 2433static int 2434pmc_can_allocate_rowindex(struct proc *p, unsigned int ri, int cpu) 2435{ 2436 enum pmc_mode mode; 2437 struct pmc *pm; 2438 struct pmc_owner *po; 2439 struct pmc_process *pp; 2440 2441 PMCDBG(PMC,ALR,1, "can-allocate-rowindex proc=%p (%d, %s) ri=%d " 2442 "cpu=%d", p, p->p_pid, p->p_comm, ri, cpu); 2443 2444 /* 2445 * We shouldn't have already allocated a process-mode PMC at 2446 * row index 'ri'. 2447 * 2448 * We shouldn't have allocated a system-wide PMC on the same 2449 * CPU and same RI. 2450 */ 2451 if ((po = pmc_find_owner_descriptor(p)) != NULL) 2452 LIST_FOREACH(pm, &po->po_pmcs, pm_next) { 2453 if (PMC_TO_ROWINDEX(pm) == ri) { 2454 mode = PMC_TO_MODE(pm); 2455 if (PMC_IS_VIRTUAL_MODE(mode)) 2456 return EEXIST; 2457 if (PMC_IS_SYSTEM_MODE(mode) && 2458 (int) PMC_TO_CPU(pm) == cpu) 2459 return EEXIST; 2460 } 2461 } 2462 2463 /* 2464 * We also shouldn't be the target of any PMC at this index 2465 * since otherwise a PMC_ATTACH to ourselves will fail. 2466 */ 2467 if ((pp = pmc_find_process_descriptor(p, 0)) != NULL) 2468 if (pp->pp_pmcs[ri].pp_pmc) 2469 return EEXIST; 2470 2471 PMCDBG(PMC,ALR,2, "can-allocate-rowindex proc=%p (%d, %s) ri=%d ok", 2472 p, p->p_pid, p->p_comm, ri); 2473 2474 return 0; 2475} 2476 2477/* 2478 * Check if a given PMC at row index 'ri' can be currently used in 2479 * mode 'mode'. 2480 */ 2481 2482static int 2483pmc_can_allocate_row(int ri, enum pmc_mode mode) 2484{ 2485 enum pmc_disp disp; 2486 2487 sx_assert(&pmc_sx, SX_XLOCKED); 2488 2489 PMCDBG(PMC,ALR,1, "can-allocate-row ri=%d mode=%d", ri, mode); 2490 2491 if (PMC_IS_SYSTEM_MODE(mode)) 2492 disp = PMC_DISP_STANDALONE; 2493 else 2494 disp = PMC_DISP_THREAD; 2495 2496 /* 2497 * check disposition for PMC row 'ri': 2498 * 2499 * Expected disposition Row-disposition Result 2500 * 2501 * STANDALONE STANDALONE or FREE proceed 2502 * STANDALONE THREAD fail 2503 * THREAD THREAD or FREE proceed 2504 * THREAD STANDALONE fail 2505 */ 2506 2507 if (!PMC_ROW_DISP_IS_FREE(ri) && 2508 !(disp == PMC_DISP_THREAD && PMC_ROW_DISP_IS_THREAD(ri)) && 2509 !(disp == PMC_DISP_STANDALONE && PMC_ROW_DISP_IS_STANDALONE(ri))) 2510 return EBUSY; 2511 2512 /* 2513 * All OK 2514 */ 2515 2516 PMCDBG(PMC,ALR,2, "can-allocate-row ri=%d mode=%d ok", ri, mode); 2517 2518 return 0; 2519 2520} 2521 2522/* 2523 * Find a PMC descriptor with user handle 'pmcid' for thread 'td'. 2524 */ 2525 2526static struct pmc * 2527pmc_find_pmc_descriptor_in_process(struct pmc_owner *po, pmc_id_t pmcid) 2528{ 2529 struct pmc *pm; 2530 2531 KASSERT(PMC_ID_TO_ROWINDEX(pmcid) < md->pmd_npmc, 2532 ("[pmc,%d] Illegal pmc index %d (max %d)", __LINE__, 2533 PMC_ID_TO_ROWINDEX(pmcid), md->pmd_npmc)); 2534 2535 LIST_FOREACH(pm, &po->po_pmcs, pm_next) 2536 if (pm->pm_id == pmcid) 2537 return pm; 2538 2539 return NULL; 2540} 2541 2542static int 2543pmc_find_pmc(pmc_id_t pmcid, struct pmc **pmc) 2544{ 2545 2546 struct pmc *pm; 2547 struct pmc_owner *po; 2548 2549 PMCDBG(PMC,FND,1, "find-pmc id=%d", pmcid); 2550 2551 if ((po = pmc_find_owner_descriptor(curthread->td_proc)) == NULL) 2552 return ESRCH; 2553 2554 if ((pm = pmc_find_pmc_descriptor_in_process(po, pmcid)) == NULL) 2555 return EINVAL; 2556 2557 PMCDBG(PMC,FND,2, "find-pmc id=%d -> pmc=%p", pmcid, pm); 2558 2559 *pmc = pm; 2560 return 0; 2561} 2562 2563/* 2564 * Start a PMC. 2565 */ 2566 2567static int 2568pmc_start(struct pmc *pm) 2569{ 2570 enum pmc_mode mode; 2571 struct pmc_owner *po; 2572 struct pmc_binding pb; 2573 struct pmc_classdep *pcd; 2574 int adjri, error, cpu, ri; 2575 2576 KASSERT(pm != NULL, 2577 ("[pmc,%d] null pm", __LINE__)); 2578 2579 mode = PMC_TO_MODE(pm); 2580 ri = PMC_TO_ROWINDEX(pm); 2581 pcd = pmc_ri_to_classdep(md, ri, &adjri); 2582 2583 error = 0; 2584 2585 PMCDBG(PMC,OPS,1, "start pmc=%p mode=%d ri=%d", pm, mode, ri); 2586 2587 po = pm->pm_owner; 2588 2589 /* 2590 * Disallow PMCSTART if a logfile is required but has not been 2591 * configured yet. 2592 */ 2593 if ((pm->pm_flags & PMC_F_NEEDS_LOGFILE) && 2594 (po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) 2595 return (EDOOFUS); /* programming error */ 2596 2597 /* 2598 * If this is a sampling mode PMC, log mapping information for 2599 * the kernel modules that are currently loaded. 2600 */ 2601 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 2602 pmc_log_kernel_mappings(pm); 2603 2604 if (PMC_IS_VIRTUAL_MODE(mode)) { 2605 2606 /* 2607 * If a PMCATTACH has never been done on this PMC, 2608 * attach it to its owner process. 2609 */ 2610 2611 if (LIST_EMPTY(&pm->pm_targets)) 2612 error = (pm->pm_flags & PMC_F_ATTACH_DONE) ? ESRCH : 2613 pmc_attach_process(po->po_owner, pm); 2614 2615 /* 2616 * If the PMC is attached to its owner, then force a context 2617 * switch to ensure that the MD state gets set correctly. 2618 */ 2619 2620 if (error == 0) { 2621 pm->pm_state = PMC_STATE_RUNNING; 2622 if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) 2623 pmc_force_context_switch(); 2624 } 2625 2626 return (error); 2627 } 2628 2629 2630 /* 2631 * A system-wide PMC. 2632 * 2633 * Add the owner to the global list if this is a system-wide 2634 * sampling PMC. 2635 */ 2636 2637 if (mode == PMC_MODE_SS) { 2638 if (po->po_sscount == 0) { 2639 LIST_INSERT_HEAD(&pmc_ss_owners, po, po_ssnext); 2640 atomic_add_rel_int(&pmc_ss_count, 1); 2641 PMCDBG(PMC,OPS,1, "po=%p in global list", po); 2642 } 2643 po->po_sscount++; 2644 2645 /* 2646 * Log mapping information for all existing processes in the 2647 * system. Subsequent mappings are logged as they happen; 2648 * see pmc_process_mmap(). 2649 */ 2650 if (po->po_logprocmaps == 0) { 2651 pmc_log_all_process_mappings(po); 2652 po->po_logprocmaps = 1; 2653 } 2654 } 2655 2656 /* 2657 * Move to the CPU associated with this 2658 * PMC, and start the hardware. 2659 */ 2660 2661 pmc_save_cpu_binding(&pb); 2662 2663 cpu = PMC_TO_CPU(pm); 2664 2665 if (!pmc_cpu_is_active(cpu)) 2666 return (ENXIO); 2667 2668 pmc_select_cpu(cpu); 2669 2670 /* 2671 * global PMCs are configured at allocation time 2672 * so write out the initial value and start the PMC. 2673 */ 2674 2675 pm->pm_state = PMC_STATE_RUNNING; 2676 2677 critical_enter(); 2678 if ((error = pcd->pcd_write_pmc(cpu, adjri, 2679 PMC_IS_SAMPLING_MODE(mode) ? 2680 pm->pm_sc.pm_reloadcount : 2681 pm->pm_sc.pm_initial)) == 0) 2682 error = pcd->pcd_start_pmc(cpu, adjri); 2683 critical_exit(); 2684 2685 pmc_restore_cpu_binding(&pb); 2686 2687 return (error); 2688} 2689 2690/* 2691 * Stop a PMC. 2692 */ 2693 2694static int 2695pmc_stop(struct pmc *pm) 2696{ 2697 struct pmc_owner *po; 2698 struct pmc_binding pb; 2699 struct pmc_classdep *pcd; 2700 int adjri, cpu, error, ri; 2701 2702 KASSERT(pm != NULL, ("[pmc,%d] null pmc", __LINE__)); 2703 2704 PMCDBG(PMC,OPS,1, "stop pmc=%p mode=%d ri=%d", pm, 2705 PMC_TO_MODE(pm), PMC_TO_ROWINDEX(pm)); 2706 2707 pm->pm_state = PMC_STATE_STOPPED; 2708 2709 /* 2710 * If the PMC is a virtual mode one, changing the state to 2711 * non-RUNNING is enough to ensure that the PMC never gets 2712 * scheduled. 2713 * 2714 * If this PMC is current running on a CPU, then it will 2715 * handled correctly at the time its target process is context 2716 * switched out. 2717 */ 2718 2719 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) 2720 return 0; 2721 2722 /* 2723 * A system-mode PMC. Move to the CPU associated with 2724 * this PMC, and stop the hardware. We update the 2725 * 'initial count' so that a subsequent PMCSTART will 2726 * resume counting from the current hardware count. 2727 */ 2728 2729 pmc_save_cpu_binding(&pb); 2730 2731 cpu = PMC_TO_CPU(pm); 2732 2733 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 2734 ("[pmc,%d] illegal cpu=%d", __LINE__, cpu)); 2735 2736 if (!pmc_cpu_is_active(cpu)) 2737 return ENXIO; 2738 2739 pmc_select_cpu(cpu); 2740 2741 ri = PMC_TO_ROWINDEX(pm); 2742 pcd = pmc_ri_to_classdep(md, ri, &adjri); 2743 2744 critical_enter(); 2745 if ((error = pcd->pcd_stop_pmc(cpu, adjri)) == 0) 2746 error = pcd->pcd_read_pmc(cpu, adjri, &pm->pm_sc.pm_initial); 2747 critical_exit(); 2748 2749 pmc_restore_cpu_binding(&pb); 2750 2751 po = pm->pm_owner; 2752 2753 /* remove this owner from the global list of SS PMC owners */ 2754 if (PMC_TO_MODE(pm) == PMC_MODE_SS) { 2755 po->po_sscount--; 2756 if (po->po_sscount == 0) { 2757 atomic_subtract_rel_int(&pmc_ss_count, 1); 2758 LIST_REMOVE(po, po_ssnext); 2759 PMCDBG(PMC,OPS,2,"po=%p removed from global list", po); 2760 } 2761 } 2762 2763 return (error); 2764} 2765 2766 2767#ifdef DEBUG 2768static const char *pmc_op_to_name[] = { 2769#undef __PMC_OP 2770#define __PMC_OP(N, D) #N , 2771 __PMC_OPS() 2772 NULL 2773}; 2774#endif 2775 2776/* 2777 * The syscall interface 2778 */ 2779 2780#define PMC_GET_SX_XLOCK(...) do { \ 2781 sx_xlock(&pmc_sx); \ 2782 if (pmc_hook == NULL) { \ 2783 sx_xunlock(&pmc_sx); \ 2784 return __VA_ARGS__; \ 2785 } \ 2786} while (0) 2787 2788#define PMC_DOWNGRADE_SX() do { \ 2789 sx_downgrade(&pmc_sx); \ 2790 is_sx_downgraded = 1; \ 2791} while (0) 2792 2793static int 2794pmc_syscall_handler(struct thread *td, void *syscall_args) 2795{ 2796 int error, is_sx_downgraded, is_sx_locked, op; 2797 struct pmc_syscall_args *c; 2798 void *arg; 2799 2800 PMC_GET_SX_XLOCK(ENOSYS); 2801 2802 DROP_GIANT(); 2803 2804 is_sx_downgraded = 0; 2805 is_sx_locked = 1; 2806 2807 c = (struct pmc_syscall_args *) syscall_args; 2808 2809 op = c->pmop_code; 2810 arg = c->pmop_data; 2811 2812 PMCDBG(MOD,PMS,1, "syscall op=%d \"%s\" arg=%p", op, 2813 pmc_op_to_name[op], arg); 2814 2815 error = 0; 2816 atomic_add_int(&pmc_stats.pm_syscalls, 1); 2817 2818 switch(op) 2819 { 2820 2821 2822 /* 2823 * Configure a log file. 2824 * 2825 * XXX This OP will be reworked. 2826 */ 2827 2828 case PMC_OP_CONFIGURELOG: 2829 { 2830 struct proc *p; 2831 struct pmc *pm; 2832 struct pmc_owner *po; 2833 struct pmc_op_configurelog cl; 2834 2835 sx_assert(&pmc_sx, SX_XLOCKED); 2836 2837 if ((error = copyin(arg, &cl, sizeof(cl))) != 0) 2838 break; 2839 2840 /* mark this process as owning a log file */ 2841 p = td->td_proc; 2842 if ((po = pmc_find_owner_descriptor(p)) == NULL) 2843 if ((po = pmc_allocate_owner_descriptor(p)) == NULL) { 2844 error = ENOMEM; 2845 break; 2846 } 2847 2848 /* 2849 * If a valid fd was passed in, try to configure that, 2850 * otherwise if 'fd' was less than zero and there was 2851 * a log file configured, flush its buffers and 2852 * de-configure it. 2853 */ 2854 if (cl.pm_logfd >= 0) { 2855 sx_xunlock(&pmc_sx); 2856 is_sx_locked = 0; 2857 error = pmclog_configure_log(md, po, cl.pm_logfd); 2858 } else if (po->po_flags & PMC_PO_OWNS_LOGFILE) { 2859 pmclog_process_closelog(po); 2860 error = pmclog_close(po); 2861 if (error == 0) { 2862 LIST_FOREACH(pm, &po->po_pmcs, pm_next) 2863 if (pm->pm_flags & PMC_F_NEEDS_LOGFILE && 2864 pm->pm_state == PMC_STATE_RUNNING) 2865 pmc_stop(pm); 2866 error = pmclog_deconfigure_log(po); 2867 } 2868 } else 2869 error = EINVAL; 2870 2871 if (error) 2872 break; 2873 } 2874 break; 2875 2876 /* 2877 * Flush a log file. 2878 */ 2879 2880 case PMC_OP_FLUSHLOG: 2881 { 2882 struct pmc_owner *po; 2883 2884 sx_assert(&pmc_sx, SX_XLOCKED); 2885 2886 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 2887 error = EINVAL; 2888 break; 2889 } 2890 2891 error = pmclog_flush(po); 2892 } 2893 break; 2894 2895 /* 2896 * Close a log file. 2897 */ 2898 2899 case PMC_OP_CLOSELOG: 2900 { 2901 struct pmc_owner *po; 2902 2903 sx_assert(&pmc_sx, SX_XLOCKED); 2904 2905 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 2906 error = EINVAL; 2907 break; 2908 } 2909 2910 error = pmclog_close(po); 2911 } 2912 break; 2913 2914 /* 2915 * Retrieve hardware configuration. 2916 */ 2917 2918 case PMC_OP_GETCPUINFO: /* CPU information */ 2919 { 2920 struct pmc_op_getcpuinfo gci; 2921 struct pmc_classinfo *pci; 2922 struct pmc_classdep *pcd; 2923 int cl; 2924 2925 gci.pm_cputype = md->pmd_cputype; 2926 gci.pm_ncpu = pmc_cpu_max(); 2927 gci.pm_npmc = md->pmd_npmc; 2928 gci.pm_nclass = md->pmd_nclass; 2929 pci = gci.pm_classes; 2930 pcd = md->pmd_classdep; 2931 for (cl = 0; cl < md->pmd_nclass; cl++, pci++, pcd++) { 2932 pci->pm_caps = pcd->pcd_caps; 2933 pci->pm_class = pcd->pcd_class; 2934 pci->pm_width = pcd->pcd_width; 2935 pci->pm_num = pcd->pcd_num; 2936 } 2937 error = copyout(&gci, arg, sizeof(gci)); 2938 } 2939 break; 2940 2941 /* 2942 * Retrieve soft events list. 2943 */ 2944 case PMC_OP_GETDYNEVENTINFO: 2945 { 2946 enum pmc_class cl; 2947 enum pmc_event ev; 2948 struct pmc_op_getdyneventinfo *gei; 2949 struct pmc_dyn_event_descr dev; 2950 struct pmc_soft *ps; 2951 uint32_t nevent; 2952 2953 sx_assert(&pmc_sx, SX_LOCKED); 2954 2955 gei = (struct pmc_op_getdyneventinfo *) arg; 2956 2957 if ((error = copyin(&gei->pm_class, &cl, sizeof(cl))) != 0) 2958 break; 2959 2960 /* Only SOFT class is dynamic. */ 2961 if (cl != PMC_CLASS_SOFT) { 2962 error = EINVAL; 2963 break; 2964 } 2965 2966 nevent = 0; 2967 for (ev = PMC_EV_SOFT_FIRST; (int)ev <= PMC_EV_SOFT_LAST; ev++) { 2968 ps = pmc_soft_ev_acquire(ev); 2969 if (ps == NULL) 2970 continue; 2971 bcopy(&ps->ps_ev, &dev, sizeof(dev)); 2972 pmc_soft_ev_release(ps); 2973 2974 error = copyout(&dev, 2975 &gei->pm_events[nevent], 2976 sizeof(struct pmc_dyn_event_descr)); 2977 if (error != 0) 2978 break; 2979 nevent++; 2980 } 2981 if (error != 0) 2982 break; 2983 2984 error = copyout(&nevent, &gei->pm_nevent, 2985 sizeof(nevent)); 2986 } 2987 break; 2988 2989 /* 2990 * Get module statistics 2991 */ 2992 2993 case PMC_OP_GETDRIVERSTATS: 2994 { 2995 struct pmc_op_getdriverstats gms; 2996 2997 bcopy(&pmc_stats, &gms, sizeof(gms)); 2998 error = copyout(&gms, arg, sizeof(gms)); 2999 } 3000 break; 3001 3002 3003 /* 3004 * Retrieve module version number 3005 */ 3006 3007 case PMC_OP_GETMODULEVERSION: 3008 { 3009 uint32_t cv, modv; 3010 3011 /* retrieve the client's idea of the ABI version */ 3012 if ((error = copyin(arg, &cv, sizeof(uint32_t))) != 0) 3013 break; 3014 /* don't service clients newer than our driver */ 3015 modv = PMC_VERSION; 3016 if ((cv & 0xFFFF0000) > (modv & 0xFFFF0000)) { 3017 error = EPROGMISMATCH; 3018 break; 3019 } 3020 error = copyout(&modv, arg, sizeof(int)); 3021 } 3022 break; 3023 3024 3025 /* 3026 * Retrieve the state of all the PMCs on a given 3027 * CPU. 3028 */ 3029 3030 case PMC_OP_GETPMCINFO: 3031 { 3032 int ari; 3033 struct pmc *pm; 3034 size_t pmcinfo_size; 3035 uint32_t cpu, n, npmc; 3036 struct pmc_owner *po; 3037 struct pmc_binding pb; 3038 struct pmc_classdep *pcd; 3039 struct pmc_info *p, *pmcinfo; 3040 struct pmc_op_getpmcinfo *gpi; 3041 3042 PMC_DOWNGRADE_SX(); 3043 3044 gpi = (struct pmc_op_getpmcinfo *) arg; 3045 3046 if ((error = copyin(&gpi->pm_cpu, &cpu, sizeof(cpu))) != 0) 3047 break; 3048 3049 if (cpu >= pmc_cpu_max()) { 3050 error = EINVAL; 3051 break; 3052 } 3053 3054 if (!pmc_cpu_is_active(cpu)) { 3055 error = ENXIO; 3056 break; 3057 } 3058 3059 /* switch to CPU 'cpu' */ 3060 pmc_save_cpu_binding(&pb); 3061 pmc_select_cpu(cpu); 3062 3063 npmc = md->pmd_npmc; 3064 3065 pmcinfo_size = npmc * sizeof(struct pmc_info); 3066 pmcinfo = malloc(pmcinfo_size, M_PMC, M_WAITOK); 3067 3068 p = pmcinfo; 3069 3070 for (n = 0; n < md->pmd_npmc; n++, p++) { 3071 3072 pcd = pmc_ri_to_classdep(md, n, &ari); 3073 3074 KASSERT(pcd != NULL, 3075 ("[pmc,%d] null pcd ri=%d", __LINE__, n)); 3076 3077 if ((error = pcd->pcd_describe(cpu, ari, p, &pm)) != 0) 3078 break; 3079 3080 if (PMC_ROW_DISP_IS_STANDALONE(n)) 3081 p->pm_rowdisp = PMC_DISP_STANDALONE; 3082 else if (PMC_ROW_DISP_IS_THREAD(n)) 3083 p->pm_rowdisp = PMC_DISP_THREAD; 3084 else 3085 p->pm_rowdisp = PMC_DISP_FREE; 3086 3087 p->pm_ownerpid = -1; 3088 3089 if (pm == NULL) /* no PMC associated */ 3090 continue; 3091 3092 po = pm->pm_owner; 3093 3094 KASSERT(po->po_owner != NULL, 3095 ("[pmc,%d] pmc_owner had a null proc pointer", 3096 __LINE__)); 3097 3098 p->pm_ownerpid = po->po_owner->p_pid; 3099 p->pm_mode = PMC_TO_MODE(pm); 3100 p->pm_event = pm->pm_event; 3101 p->pm_flags = pm->pm_flags; 3102 3103 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 3104 p->pm_reloadcount = 3105 pm->pm_sc.pm_reloadcount; 3106 } 3107 3108 pmc_restore_cpu_binding(&pb); 3109 3110 /* now copy out the PMC info collected */ 3111 if (error == 0) 3112 error = copyout(pmcinfo, &gpi->pm_pmcs, pmcinfo_size); 3113 3114 free(pmcinfo, M_PMC); 3115 } 3116 break; 3117 3118 3119 /* 3120 * Set the administrative state of a PMC. I.e. whether 3121 * the PMC is to be used or not. 3122 */ 3123 3124 case PMC_OP_PMCADMIN: 3125 { 3126 int cpu, ri; 3127 enum pmc_state request; 3128 struct pmc_cpu *pc; 3129 struct pmc_hw *phw; 3130 struct pmc_op_pmcadmin pma; 3131 struct pmc_binding pb; 3132 3133 sx_assert(&pmc_sx, SX_XLOCKED); 3134 3135 KASSERT(td == curthread, 3136 ("[pmc,%d] td != curthread", __LINE__)); 3137 3138 error = priv_check(td, PRIV_PMC_MANAGE); 3139 if (error) 3140 break; 3141 3142 if ((error = copyin(arg, &pma, sizeof(pma))) != 0) 3143 break; 3144 3145 cpu = pma.pm_cpu; 3146 3147 if (cpu < 0 || cpu >= (int) pmc_cpu_max()) { 3148 error = EINVAL; 3149 break; 3150 } 3151 3152 if (!pmc_cpu_is_active(cpu)) { 3153 error = ENXIO; 3154 break; 3155 } 3156 3157 request = pma.pm_state; 3158 3159 if (request != PMC_STATE_DISABLED && 3160 request != PMC_STATE_FREE) { 3161 error = EINVAL; 3162 break; 3163 } 3164 3165 ri = pma.pm_pmc; /* pmc id == row index */ 3166 if (ri < 0 || ri >= (int) md->pmd_npmc) { 3167 error = EINVAL; 3168 break; 3169 } 3170 3171 /* 3172 * We can't disable a PMC with a row-index allocated 3173 * for process virtual PMCs. 3174 */ 3175 3176 if (PMC_ROW_DISP_IS_THREAD(ri) && 3177 request == PMC_STATE_DISABLED) { 3178 error = EBUSY; 3179 break; 3180 } 3181 3182 /* 3183 * otherwise, this PMC on this CPU is either free or 3184 * in system-wide mode. 3185 */ 3186 3187 pmc_save_cpu_binding(&pb); 3188 pmc_select_cpu(cpu); 3189 3190 pc = pmc_pcpu[cpu]; 3191 phw = pc->pc_hwpmcs[ri]; 3192 3193 /* 3194 * XXX do we need some kind of 'forced' disable? 3195 */ 3196 3197 if (phw->phw_pmc == NULL) { 3198 if (request == PMC_STATE_DISABLED && 3199 (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED)) { 3200 phw->phw_state &= ~PMC_PHW_FLAG_IS_ENABLED; 3201 PMC_MARK_ROW_STANDALONE(ri); 3202 } else if (request == PMC_STATE_FREE && 3203 (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0) { 3204 phw->phw_state |= PMC_PHW_FLAG_IS_ENABLED; 3205 PMC_UNMARK_ROW_STANDALONE(ri); 3206 } 3207 /* other cases are a no-op */ 3208 } else 3209 error = EBUSY; 3210 3211 pmc_restore_cpu_binding(&pb); 3212 } 3213 break; 3214 3215 3216 /* 3217 * Allocate a PMC. 3218 */ 3219 3220 case PMC_OP_PMCALLOCATE: 3221 { 3222 int adjri, n; 3223 u_int cpu; 3224 uint32_t caps; 3225 struct pmc *pmc; 3226 enum pmc_mode mode; 3227 struct pmc_hw *phw; 3228 struct pmc_binding pb; 3229 struct pmc_classdep *pcd; 3230 struct pmc_op_pmcallocate pa; 3231 3232 if ((error = copyin(arg, &pa, sizeof(pa))) != 0) 3233 break; 3234 3235 caps = pa.pm_caps; 3236 mode = pa.pm_mode; 3237 cpu = pa.pm_cpu; 3238 3239 if ((mode != PMC_MODE_SS && mode != PMC_MODE_SC && 3240 mode != PMC_MODE_TS && mode != PMC_MODE_TC) || 3241 (cpu != (u_int) PMC_CPU_ANY && cpu >= pmc_cpu_max())) { 3242 error = EINVAL; 3243 break; 3244 } 3245 3246 /* 3247 * Virtual PMCs should only ask for a default CPU. 3248 * System mode PMCs need to specify a non-default CPU. 3249 */ 3250 3251 if ((PMC_IS_VIRTUAL_MODE(mode) && cpu != (u_int) PMC_CPU_ANY) || 3252 (PMC_IS_SYSTEM_MODE(mode) && cpu == (u_int) PMC_CPU_ANY)) { 3253 error = EINVAL; 3254 break; 3255 } 3256 3257 /* 3258 * Check that an inactive CPU is not being asked for. 3259 */ 3260 3261 if (PMC_IS_SYSTEM_MODE(mode) && !pmc_cpu_is_active(cpu)) { 3262 error = ENXIO; 3263 break; 3264 } 3265 3266 /* 3267 * Refuse an allocation for a system-wide PMC if this 3268 * process has been jailed, or if this process lacks 3269 * super-user credentials and the sysctl tunable 3270 * 'security.bsd.unprivileged_syspmcs' is zero. 3271 */ 3272 3273 if (PMC_IS_SYSTEM_MODE(mode)) { 3274 if (jailed(curthread->td_ucred)) { 3275 error = EPERM; 3276 break; 3277 } 3278 if (!pmc_unprivileged_syspmcs) { 3279 error = priv_check(curthread, 3280 PRIV_PMC_SYSTEM); 3281 if (error) 3282 break; 3283 } 3284 } 3285 3286 /* 3287 * Look for valid values for 'pm_flags' 3288 */ 3289 3290 if ((pa.pm_flags & ~(PMC_F_DESCENDANTS | PMC_F_LOG_PROCCSW | 3291 PMC_F_LOG_PROCEXIT | PMC_F_CALLCHAIN)) != 0) { 3292 error = EINVAL; 3293 break; 3294 } 3295 3296 /* process logging options are not allowed for system PMCs */ 3297 if (PMC_IS_SYSTEM_MODE(mode) && (pa.pm_flags & 3298 (PMC_F_LOG_PROCCSW | PMC_F_LOG_PROCEXIT))) { 3299 error = EINVAL; 3300 break; 3301 } 3302 3303 /* 3304 * All sampling mode PMCs need to be able to interrupt the 3305 * CPU. 3306 */ 3307 if (PMC_IS_SAMPLING_MODE(mode)) 3308 caps |= PMC_CAP_INTERRUPT; 3309 3310 /* A valid class specifier should have been passed in. */ 3311 for (n = 0; n < md->pmd_nclass; n++) 3312 if (md->pmd_classdep[n].pcd_class == pa.pm_class) 3313 break; 3314 if (n == md->pmd_nclass) { 3315 error = EINVAL; 3316 break; 3317 } 3318 3319 /* The requested PMC capabilities should be feasible. */ 3320 if ((md->pmd_classdep[n].pcd_caps & caps) != caps) { 3321 error = EOPNOTSUPP; 3322 break; 3323 } 3324 3325 PMCDBG(PMC,ALL,2, "event=%d caps=0x%x mode=%d cpu=%d", 3326 pa.pm_ev, caps, mode, cpu); 3327 3328 pmc = pmc_allocate_pmc_descriptor(); 3329 pmc->pm_id = PMC_ID_MAKE_ID(cpu,pa.pm_mode,pa.pm_class, 3330 PMC_ID_INVALID); 3331 pmc->pm_event = pa.pm_ev; 3332 pmc->pm_state = PMC_STATE_FREE; 3333 pmc->pm_caps = caps; 3334 pmc->pm_flags = pa.pm_flags; 3335 3336 /* switch thread to CPU 'cpu' */ 3337 pmc_save_cpu_binding(&pb); 3338 3339#define PMC_IS_SHAREABLE_PMC(cpu, n) \ 3340 (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_state & \ 3341 PMC_PHW_FLAG_IS_SHAREABLE) 3342#define PMC_IS_UNALLOCATED(cpu, n) \ 3343 (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_pmc == NULL) 3344 3345 if (PMC_IS_SYSTEM_MODE(mode)) { 3346 pmc_select_cpu(cpu); 3347 for (n = 0; n < (int) md->pmd_npmc; n++) { 3348 pcd = pmc_ri_to_classdep(md, n, &adjri); 3349 if (pmc_can_allocate_row(n, mode) == 0 && 3350 pmc_can_allocate_rowindex( 3351 curthread->td_proc, n, cpu) == 0 && 3352 (PMC_IS_UNALLOCATED(cpu, n) || 3353 PMC_IS_SHAREABLE_PMC(cpu, n)) && 3354 pcd->pcd_allocate_pmc(cpu, adjri, pmc, 3355 &pa) == 0) 3356 break; 3357 } 3358 } else { 3359 /* Process virtual mode */ 3360 for (n = 0; n < (int) md->pmd_npmc; n++) { 3361 pcd = pmc_ri_to_classdep(md, n, &adjri); 3362 if (pmc_can_allocate_row(n, mode) == 0 && 3363 pmc_can_allocate_rowindex( 3364 curthread->td_proc, n, 3365 PMC_CPU_ANY) == 0 && 3366 pcd->pcd_allocate_pmc(curthread->td_oncpu, 3367 adjri, pmc, &pa) == 0) 3368 break; 3369 } 3370 } 3371 3372#undef PMC_IS_UNALLOCATED 3373#undef PMC_IS_SHAREABLE_PMC 3374 3375 pmc_restore_cpu_binding(&pb); 3376 3377 if (n == (int) md->pmd_npmc) { 3378 pmc_destroy_pmc_descriptor(pmc); 3379 pmc = NULL; 3380 error = EINVAL; 3381 break; 3382 } 3383 3384 /* Fill in the correct value in the ID field */ 3385 pmc->pm_id = PMC_ID_MAKE_ID(cpu,mode,pa.pm_class,n); 3386 3387 PMCDBG(PMC,ALL,2, "ev=%d class=%d mode=%d n=%d -> pmcid=%x", 3388 pmc->pm_event, pa.pm_class, mode, n, pmc->pm_id); 3389 3390 /* Process mode PMCs with logging enabled need log files */ 3391 if (pmc->pm_flags & (PMC_F_LOG_PROCEXIT | PMC_F_LOG_PROCCSW)) 3392 pmc->pm_flags |= PMC_F_NEEDS_LOGFILE; 3393 3394 /* All system mode sampling PMCs require a log file */ 3395 if (PMC_IS_SAMPLING_MODE(mode) && PMC_IS_SYSTEM_MODE(mode)) 3396 pmc->pm_flags |= PMC_F_NEEDS_LOGFILE; 3397 3398 /* 3399 * Configure global pmc's immediately 3400 */ 3401 3402 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pmc))) { 3403 3404 pmc_save_cpu_binding(&pb); 3405 pmc_select_cpu(cpu); 3406 3407 phw = pmc_pcpu[cpu]->pc_hwpmcs[n]; 3408 pcd = pmc_ri_to_classdep(md, n, &adjri); 3409 3410 if ((phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0 || 3411 (error = pcd->pcd_config_pmc(cpu, adjri, pmc)) != 0) { 3412 (void) pcd->pcd_release_pmc(cpu, adjri, pmc); 3413 pmc_destroy_pmc_descriptor(pmc); 3414 pmc = NULL; 3415 pmc_restore_cpu_binding(&pb); 3416 error = EPERM; 3417 break; 3418 } 3419 3420 pmc_restore_cpu_binding(&pb); 3421 } 3422 3423 pmc->pm_state = PMC_STATE_ALLOCATED; 3424 3425 /* 3426 * mark row disposition 3427 */ 3428 3429 if (PMC_IS_SYSTEM_MODE(mode)) 3430 PMC_MARK_ROW_STANDALONE(n); 3431 else 3432 PMC_MARK_ROW_THREAD(n); 3433 3434 /* 3435 * Register this PMC with the current thread as its owner. 3436 */ 3437 3438 if ((error = 3439 pmc_register_owner(curthread->td_proc, pmc)) != 0) { 3440 pmc_release_pmc_descriptor(pmc); 3441 pmc_destroy_pmc_descriptor(pmc); 3442 pmc = NULL; 3443 break; 3444 } 3445 3446 /* 3447 * Return the allocated index. 3448 */ 3449 3450 pa.pm_pmcid = pmc->pm_id; 3451 3452 error = copyout(&pa, arg, sizeof(pa)); 3453 } 3454 break; 3455 3456 3457 /* 3458 * Attach a PMC to a process. 3459 */ 3460 3461 case PMC_OP_PMCATTACH: 3462 { 3463 struct pmc *pm; 3464 struct proc *p; 3465 struct pmc_op_pmcattach a; 3466 3467 sx_assert(&pmc_sx, SX_XLOCKED); 3468 3469 if ((error = copyin(arg, &a, sizeof(a))) != 0) 3470 break; 3471 3472 if (a.pm_pid < 0) { 3473 error = EINVAL; 3474 break; 3475 } else if (a.pm_pid == 0) 3476 a.pm_pid = td->td_proc->p_pid; 3477 3478 if ((error = pmc_find_pmc(a.pm_pmc, &pm)) != 0) 3479 break; 3480 3481 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) { 3482 error = EINVAL; 3483 break; 3484 } 3485 3486 /* PMCs may be (re)attached only when allocated or stopped */ 3487 if (pm->pm_state == PMC_STATE_RUNNING) { 3488 error = EBUSY; 3489 break; 3490 } else if (pm->pm_state != PMC_STATE_ALLOCATED && 3491 pm->pm_state != PMC_STATE_STOPPED) { 3492 error = EINVAL; 3493 break; 3494 } 3495 3496 /* lookup pid */ 3497 if ((p = pfind(a.pm_pid)) == NULL) { 3498 error = ESRCH; 3499 break; 3500 } 3501 3502 /* 3503 * Ignore processes that are working on exiting. 3504 */ 3505 if (p->p_flag & P_WEXIT) { 3506 error = ESRCH; 3507 PROC_UNLOCK(p); /* pfind() returns a locked process */ 3508 break; 3509 } 3510 3511 /* 3512 * we are allowed to attach a PMC to a process if 3513 * we can debug it. 3514 */ 3515 error = p_candebug(curthread, p); 3516 3517 PROC_UNLOCK(p); 3518 3519 if (error == 0) 3520 error = pmc_attach_process(p, pm); 3521 } 3522 break; 3523 3524 3525 /* 3526 * Detach an attached PMC from a process. 3527 */ 3528 3529 case PMC_OP_PMCDETACH: 3530 { 3531 struct pmc *pm; 3532 struct proc *p; 3533 struct pmc_op_pmcattach a; 3534 3535 if ((error = copyin(arg, &a, sizeof(a))) != 0) 3536 break; 3537 3538 if (a.pm_pid < 0) { 3539 error = EINVAL; 3540 break; 3541 } else if (a.pm_pid == 0) 3542 a.pm_pid = td->td_proc->p_pid; 3543 3544 if ((error = pmc_find_pmc(a.pm_pmc, &pm)) != 0) 3545 break; 3546 3547 if ((p = pfind(a.pm_pid)) == NULL) { 3548 error = ESRCH; 3549 break; 3550 } 3551 3552 /* 3553 * Treat processes that are in the process of exiting 3554 * as if they were not present. 3555 */ 3556 3557 if (p->p_flag & P_WEXIT) 3558 error = ESRCH; 3559 3560 PROC_UNLOCK(p); /* pfind() returns a locked process */ 3561 3562 if (error == 0) 3563 error = pmc_detach_process(p, pm); 3564 } 3565 break; 3566 3567 3568 /* 3569 * Retrieve the MSR number associated with the counter 3570 * 'pmc_id'. This allows processes to directly use RDPMC 3571 * instructions to read their PMCs, without the overhead of a 3572 * system call. 3573 */ 3574 3575 case PMC_OP_PMCGETMSR: 3576 { 3577 int adjri, ri; 3578 struct pmc *pm; 3579 struct pmc_target *pt; 3580 struct pmc_op_getmsr gm; 3581 struct pmc_classdep *pcd; 3582 3583 PMC_DOWNGRADE_SX(); 3584 3585 if ((error = copyin(arg, &gm, sizeof(gm))) != 0) 3586 break; 3587 3588 if ((error = pmc_find_pmc(gm.pm_pmcid, &pm)) != 0) 3589 break; 3590 3591 /* 3592 * The allocated PMC has to be a process virtual PMC, 3593 * i.e., of type MODE_T[CS]. Global PMCs can only be 3594 * read using the PMCREAD operation since they may be 3595 * allocated on a different CPU than the one we could 3596 * be running on at the time of the RDPMC instruction. 3597 * 3598 * The GETMSR operation is not allowed for PMCs that 3599 * are inherited across processes. 3600 */ 3601 3602 if (!PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)) || 3603 (pm->pm_flags & PMC_F_DESCENDANTS)) { 3604 error = EINVAL; 3605 break; 3606 } 3607 3608 /* 3609 * It only makes sense to use a RDPMC (or its 3610 * equivalent instruction on non-x86 architectures) on 3611 * a process that has allocated and attached a PMC to 3612 * itself. Conversely the PMC is only allowed to have 3613 * one process attached to it -- its owner. 3614 */ 3615 3616 if ((pt = LIST_FIRST(&pm->pm_targets)) == NULL || 3617 LIST_NEXT(pt, pt_next) != NULL || 3618 pt->pt_process->pp_proc != pm->pm_owner->po_owner) { 3619 error = EINVAL; 3620 break; 3621 } 3622 3623 ri = PMC_TO_ROWINDEX(pm); 3624 pcd = pmc_ri_to_classdep(md, ri, &adjri); 3625 3626 /* PMC class has no 'GETMSR' support */ 3627 if (pcd->pcd_get_msr == NULL) { 3628 error = ENOSYS; 3629 break; 3630 } 3631 3632 if ((error = (*pcd->pcd_get_msr)(adjri, &gm.pm_msr)) < 0) 3633 break; 3634 3635 if ((error = copyout(&gm, arg, sizeof(gm))) < 0) 3636 break; 3637 3638 /* 3639 * Mark our process as using MSRs. Update machine 3640 * state using a forced context switch. 3641 */ 3642 3643 pt->pt_process->pp_flags |= PMC_PP_ENABLE_MSR_ACCESS; 3644 pmc_force_context_switch(); 3645 3646 } 3647 break; 3648 3649 /* 3650 * Release an allocated PMC 3651 */ 3652 3653 case PMC_OP_PMCRELEASE: 3654 { 3655 pmc_id_t pmcid; 3656 struct pmc *pm; 3657 struct pmc_owner *po; 3658 struct pmc_op_simple sp; 3659 3660 /* 3661 * Find PMC pointer for the named PMC. 3662 * 3663 * Use pmc_release_pmc_descriptor() to switch off the 3664 * PMC, remove all its target threads, and remove the 3665 * PMC from its owner's list. 3666 * 3667 * Remove the owner record if this is the last PMC 3668 * owned. 3669 * 3670 * Free up space. 3671 */ 3672 3673 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 3674 break; 3675 3676 pmcid = sp.pm_pmcid; 3677 3678 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 3679 break; 3680 3681 po = pm->pm_owner; 3682 pmc_release_pmc_descriptor(pm); 3683 pmc_maybe_remove_owner(po); 3684 pmc_destroy_pmc_descriptor(pm); 3685 } 3686 break; 3687 3688 3689 /* 3690 * Read and/or write a PMC. 3691 */ 3692 3693 case PMC_OP_PMCRW: 3694 { 3695 int adjri; 3696 struct pmc *pm; 3697 uint32_t cpu, ri; 3698 pmc_value_t oldvalue; 3699 struct pmc_binding pb; 3700 struct pmc_op_pmcrw prw; 3701 struct pmc_classdep *pcd; 3702 struct pmc_op_pmcrw *pprw; 3703 3704 PMC_DOWNGRADE_SX(); 3705 3706 if ((error = copyin(arg, &prw, sizeof(prw))) != 0) 3707 break; 3708 3709 ri = 0; 3710 PMCDBG(PMC,OPS,1, "rw id=%d flags=0x%x", prw.pm_pmcid, 3711 prw.pm_flags); 3712 3713 /* must have at least one flag set */ 3714 if ((prw.pm_flags & (PMC_F_OLDVALUE|PMC_F_NEWVALUE)) == 0) { 3715 error = EINVAL; 3716 break; 3717 } 3718 3719 /* locate pmc descriptor */ 3720 if ((error = pmc_find_pmc(prw.pm_pmcid, &pm)) != 0) 3721 break; 3722 3723 /* Can't read a PMC that hasn't been started. */ 3724 if (pm->pm_state != PMC_STATE_ALLOCATED && 3725 pm->pm_state != PMC_STATE_STOPPED && 3726 pm->pm_state != PMC_STATE_RUNNING) { 3727 error = EINVAL; 3728 break; 3729 } 3730 3731 /* writing a new value is allowed only for 'STOPPED' pmcs */ 3732 if (pm->pm_state == PMC_STATE_RUNNING && 3733 (prw.pm_flags & PMC_F_NEWVALUE)) { 3734 error = EBUSY; 3735 break; 3736 } 3737 3738 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) { 3739 3740 /* 3741 * If this PMC is attached to its owner (i.e., 3742 * the process requesting this operation) and 3743 * is running, then attempt to get an 3744 * upto-date reading from hardware for a READ. 3745 * Writes are only allowed when the PMC is 3746 * stopped, so only update the saved value 3747 * field. 3748 * 3749 * If the PMC is not running, or is not 3750 * attached to its owner, read/write to the 3751 * savedvalue field. 3752 */ 3753 3754 ri = PMC_TO_ROWINDEX(pm); 3755 pcd = pmc_ri_to_classdep(md, ri, &adjri); 3756 3757 mtx_pool_lock_spin(pmc_mtxpool, pm); 3758 cpu = curthread->td_oncpu; 3759 3760 if (prw.pm_flags & PMC_F_OLDVALUE) { 3761 if ((pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) && 3762 (pm->pm_state == PMC_STATE_RUNNING)) 3763 error = (*pcd->pcd_read_pmc)(cpu, adjri, 3764 &oldvalue); 3765 else 3766 oldvalue = pm->pm_gv.pm_savedvalue; 3767 } 3768 if (prw.pm_flags & PMC_F_NEWVALUE) 3769 pm->pm_gv.pm_savedvalue = prw.pm_value; 3770 3771 mtx_pool_unlock_spin(pmc_mtxpool, pm); 3772 3773 } else { /* System mode PMCs */ 3774 cpu = PMC_TO_CPU(pm); 3775 ri = PMC_TO_ROWINDEX(pm); 3776 pcd = pmc_ri_to_classdep(md, ri, &adjri); 3777 3778 if (!pmc_cpu_is_active(cpu)) { 3779 error = ENXIO; 3780 break; 3781 } 3782 3783 /* move this thread to CPU 'cpu' */ 3784 pmc_save_cpu_binding(&pb); 3785 pmc_select_cpu(cpu); 3786 3787 critical_enter(); 3788 /* save old value */ 3789 if (prw.pm_flags & PMC_F_OLDVALUE) 3790 if ((error = (*pcd->pcd_read_pmc)(cpu, adjri, 3791 &oldvalue))) 3792 goto error; 3793 /* write out new value */ 3794 if (prw.pm_flags & PMC_F_NEWVALUE) 3795 error = (*pcd->pcd_write_pmc)(cpu, adjri, 3796 prw.pm_value); 3797 error: 3798 critical_exit(); 3799 pmc_restore_cpu_binding(&pb); 3800 if (error) 3801 break; 3802 } 3803 3804 pprw = (struct pmc_op_pmcrw *) arg; 3805 3806#ifdef DEBUG 3807 if (prw.pm_flags & PMC_F_NEWVALUE) 3808 PMCDBG(PMC,OPS,2, "rw id=%d new %jx -> old %jx", 3809 ri, prw.pm_value, oldvalue); 3810 else if (prw.pm_flags & PMC_F_OLDVALUE) 3811 PMCDBG(PMC,OPS,2, "rw id=%d -> old %jx", ri, oldvalue); 3812#endif 3813 3814 /* return old value if requested */ 3815 if (prw.pm_flags & PMC_F_OLDVALUE) 3816 if ((error = copyout(&oldvalue, &pprw->pm_value, 3817 sizeof(prw.pm_value)))) 3818 break; 3819 3820 } 3821 break; 3822 3823 3824 /* 3825 * Set the sampling rate for a sampling mode PMC and the 3826 * initial count for a counting mode PMC. 3827 */ 3828 3829 case PMC_OP_PMCSETCOUNT: 3830 { 3831 struct pmc *pm; 3832 struct pmc_op_pmcsetcount sc; 3833 3834 PMC_DOWNGRADE_SX(); 3835 3836 if ((error = copyin(arg, &sc, sizeof(sc))) != 0) 3837 break; 3838 3839 if ((error = pmc_find_pmc(sc.pm_pmcid, &pm)) != 0) 3840 break; 3841 3842 if (pm->pm_state == PMC_STATE_RUNNING) { 3843 error = EBUSY; 3844 break; 3845 } 3846 3847 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 3848 pm->pm_sc.pm_reloadcount = sc.pm_count; 3849 else 3850 pm->pm_sc.pm_initial = sc.pm_count; 3851 } 3852 break; 3853 3854 3855 /* 3856 * Start a PMC. 3857 */ 3858 3859 case PMC_OP_PMCSTART: 3860 { 3861 pmc_id_t pmcid; 3862 struct pmc *pm; 3863 struct pmc_op_simple sp; 3864 3865 sx_assert(&pmc_sx, SX_XLOCKED); 3866 3867 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 3868 break; 3869 3870 pmcid = sp.pm_pmcid; 3871 3872 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 3873 break; 3874 3875 KASSERT(pmcid == pm->pm_id, 3876 ("[pmc,%d] pmcid %x != id %x", __LINE__, 3877 pm->pm_id, pmcid)); 3878 3879 if (pm->pm_state == PMC_STATE_RUNNING) /* already running */ 3880 break; 3881 else if (pm->pm_state != PMC_STATE_STOPPED && 3882 pm->pm_state != PMC_STATE_ALLOCATED) { 3883 error = EINVAL; 3884 break; 3885 } 3886 3887 error = pmc_start(pm); 3888 } 3889 break; 3890 3891 3892 /* 3893 * Stop a PMC. 3894 */ 3895 3896 case PMC_OP_PMCSTOP: 3897 { 3898 pmc_id_t pmcid; 3899 struct pmc *pm; 3900 struct pmc_op_simple sp; 3901 3902 PMC_DOWNGRADE_SX(); 3903 3904 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 3905 break; 3906 3907 pmcid = sp.pm_pmcid; 3908 3909 /* 3910 * Mark the PMC as inactive and invoke the MD stop 3911 * routines if needed. 3912 */ 3913 3914 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 3915 break; 3916 3917 KASSERT(pmcid == pm->pm_id, 3918 ("[pmc,%d] pmc id %x != pmcid %x", __LINE__, 3919 pm->pm_id, pmcid)); 3920 3921 if (pm->pm_state == PMC_STATE_STOPPED) /* already stopped */ 3922 break; 3923 else if (pm->pm_state != PMC_STATE_RUNNING) { 3924 error = EINVAL; 3925 break; 3926 } 3927 3928 error = pmc_stop(pm); 3929 } 3930 break; 3931 3932 3933 /* 3934 * Write a user supplied value to the log file. 3935 */ 3936 3937 case PMC_OP_WRITELOG: 3938 { 3939 struct pmc_op_writelog wl; 3940 struct pmc_owner *po; 3941 3942 PMC_DOWNGRADE_SX(); 3943 3944 if ((error = copyin(arg, &wl, sizeof(wl))) != 0) 3945 break; 3946 3947 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 3948 error = EINVAL; 3949 break; 3950 } 3951 3952 if ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) { 3953 error = EINVAL; 3954 break; 3955 } 3956 3957 error = pmclog_process_userlog(po, &wl); 3958 } 3959 break; 3960 3961 3962 default: 3963 error = EINVAL; 3964 break; 3965 } 3966 3967 if (is_sx_locked != 0) { 3968 if (is_sx_downgraded) 3969 sx_sunlock(&pmc_sx); 3970 else 3971 sx_xunlock(&pmc_sx); 3972 } 3973 3974 if (error) 3975 atomic_add_int(&pmc_stats.pm_syscall_errors, 1); 3976 3977 PICKUP_GIANT(); 3978 3979 return error; 3980} 3981 3982/* 3983 * Helper functions 3984 */ 3985 3986 3987/* 3988 * Mark the thread as needing callchain capture and post an AST. The 3989 * actual callchain capture will be done in a context where it is safe 3990 * to take page faults. 3991 */ 3992 3993static void 3994pmc_post_callchain_callback(void) 3995{ 3996 struct thread *td; 3997 3998 td = curthread; 3999 4000 /* 4001 * If there is multiple PMCs for the same interrupt ignore new post 4002 */ 4003 if (td->td_pflags & TDP_CALLCHAIN) 4004 return; 4005 4006 /* 4007 * Mark this thread as needing callchain capture. 4008 * `td->td_pflags' will be safe to touch because this thread 4009 * was in user space when it was interrupted. 4010 */ 4011 td->td_pflags |= TDP_CALLCHAIN; 4012 4013 /* 4014 * Don't let this thread migrate between CPUs until callchain 4015 * capture completes. 4016 */ 4017 sched_pin(); 4018 4019 return; 4020} 4021 4022/* 4023 * Interrupt processing. 4024 * 4025 * Find a free slot in the per-cpu array of samples and capture the 4026 * current callchain there. If a sample was successfully added, a bit 4027 * is set in mask 'pmc_cpumask' denoting that the DO_SAMPLES hook 4028 * needs to be invoked from the clock handler. 4029 * 4030 * This function is meant to be called from an NMI handler. It cannot 4031 * use any of the locking primitives supplied by the OS. 4032 */ 4033 4034int 4035pmc_process_interrupt(int cpu, int ring, struct pmc *pm, struct trapframe *tf, 4036 int inuserspace) 4037{ 4038 int error, callchaindepth; 4039 struct thread *td; 4040 struct pmc_sample *ps; 4041 struct pmc_samplebuffer *psb; 4042 4043 error = 0; 4044 4045 /* 4046 * Allocate space for a sample buffer. 4047 */ 4048 psb = pmc_pcpu[cpu]->pc_sb[ring]; 4049 4050 ps = psb->ps_write; 4051 if (ps->ps_nsamples) { /* in use, reader hasn't caught up */ 4052 pm->pm_stalled = 1; 4053 atomic_add_int(&pmc_stats.pm_intr_bufferfull, 1); 4054 PMCDBG(SAM,INT,1,"(spc) cpu=%d pm=%p tf=%p um=%d wr=%d rd=%d", 4055 cpu, pm, (void *) tf, inuserspace, 4056 (int) (psb->ps_write - psb->ps_samples), 4057 (int) (psb->ps_read - psb->ps_samples)); 4058 error = ENOMEM; 4059 goto done; 4060 } 4061 4062 4063 /* Fill in entry. */ 4064 PMCDBG(SAM,INT,1,"cpu=%d pm=%p tf=%p um=%d wr=%d rd=%d", cpu, pm, 4065 (void *) tf, inuserspace, 4066 (int) (psb->ps_write - psb->ps_samples), 4067 (int) (psb->ps_read - psb->ps_samples)); 4068 4069 KASSERT(pm->pm_runcount >= 0, 4070 ("[pmc,%d] pm=%p runcount %d", __LINE__, (void *) pm, 4071 pm->pm_runcount)); 4072 4073 atomic_add_rel_int(&pm->pm_runcount, 1); /* hold onto PMC */ 4074 4075 ps->ps_pmc = pm; 4076 if ((td = curthread) && td->td_proc) 4077 ps->ps_pid = td->td_proc->p_pid; 4078 else 4079 ps->ps_pid = -1; 4080 ps->ps_cpu = cpu; 4081 ps->ps_td = td; 4082 ps->ps_flags = inuserspace ? PMC_CC_F_USERSPACE : 0; 4083 4084 callchaindepth = (pm->pm_flags & PMC_F_CALLCHAIN) ? 4085 pmc_callchaindepth : 1; 4086 4087 if (callchaindepth == 1) 4088 ps->ps_pc[0] = PMC_TRAPFRAME_TO_PC(tf); 4089 else { 4090 /* 4091 * Kernel stack traversals can be done immediately, 4092 * while we defer to an AST for user space traversals. 4093 */ 4094 if (!inuserspace) { 4095 callchaindepth = 4096 pmc_save_kernel_callchain(ps->ps_pc, 4097 callchaindepth, tf); 4098 } else { 4099 pmc_post_callchain_callback(); 4100 callchaindepth = PMC_SAMPLE_INUSE; 4101 } 4102 } 4103 4104 ps->ps_nsamples = callchaindepth; /* mark entry as in use */ 4105 4106 /* increment write pointer, modulo ring buffer size */ 4107 ps++; 4108 if (ps == psb->ps_fence) 4109 psb->ps_write = psb->ps_samples; 4110 else 4111 psb->ps_write = ps; 4112 4113 done: 4114 /* mark CPU as needing processing */ 4115 CPU_SET_ATOMIC(cpu, &pmc_cpumask); 4116 4117 return (error); 4118} 4119 4120/* 4121 * Capture a user call chain. This function will be called from ast() 4122 * before control returns to userland and before the process gets 4123 * rescheduled. 4124 */ 4125 4126static void 4127pmc_capture_user_callchain(int cpu, int ring, struct trapframe *tf) 4128{ 4129 int i; 4130 struct pmc *pm; 4131 struct thread *td; 4132 struct pmc_sample *ps; 4133 struct pmc_samplebuffer *psb; 4134#ifdef INVARIANTS 4135 int ncallchains; 4136#endif 4137 4138 psb = pmc_pcpu[cpu]->pc_sb[ring]; 4139 td = curthread; 4140 4141 KASSERT(td->td_pflags & TDP_CALLCHAIN, 4142 ("[pmc,%d] Retrieving callchain for thread that doesn't want it", 4143 __LINE__)); 4144 4145#ifdef INVARIANTS 4146 ncallchains = 0; 4147#endif 4148 4149 /* 4150 * Iterate through all deferred callchain requests. 4151 */ 4152 4153 ps = psb->ps_samples; 4154 for (i = 0; i < pmc_nsamples; i++, ps++) { 4155 4156 if (ps->ps_nsamples != PMC_SAMPLE_INUSE) 4157 continue; 4158 if (ps->ps_td != td) 4159 continue; 4160 4161 KASSERT(ps->ps_cpu == cpu, 4162 ("[pmc,%d] cpu mismatch ps_cpu=%d pcpu=%d", __LINE__, 4163 ps->ps_cpu, PCPU_GET(cpuid))); 4164 4165 pm = ps->ps_pmc; 4166 4167 KASSERT(pm->pm_flags & PMC_F_CALLCHAIN, 4168 ("[pmc,%d] Retrieving callchain for PMC that doesn't " 4169 "want it", __LINE__)); 4170 4171 KASSERT(pm->pm_runcount > 0, 4172 ("[pmc,%d] runcount %d", __LINE__, pm->pm_runcount)); 4173 4174 /* 4175 * Retrieve the callchain and mark the sample buffer 4176 * as 'processable' by the timer tick sweep code. 4177 */ 4178 ps->ps_nsamples = pmc_save_user_callchain(ps->ps_pc, 4179 pmc_callchaindepth, tf); 4180 4181#ifdef INVARIANTS 4182 ncallchains++; 4183#endif 4184 } 4185 4186 KASSERT(ncallchains > 0, 4187 ("[pmc,%d] cpu %d didn't find a sample to collect", __LINE__, 4188 cpu)); 4189 4190 KASSERT(td->td_pinned == 1, 4191 ("[pmc,%d] invalid td_pinned value", __LINE__)); 4192 sched_unpin(); /* Can migrate safely now. */ 4193 4194 return; 4195} 4196 4197/* 4198 * Process saved PC samples. 4199 */ 4200 4201static void 4202pmc_process_samples(int cpu, int ring) 4203{ 4204 struct pmc *pm; 4205 int adjri, n; 4206 struct thread *td; 4207 struct pmc_owner *po; 4208 struct pmc_sample *ps; 4209 struct pmc_classdep *pcd; 4210 struct pmc_samplebuffer *psb; 4211 4212 KASSERT(PCPU_GET(cpuid) == cpu, 4213 ("[pmc,%d] not on the correct CPU pcpu=%d cpu=%d", __LINE__, 4214 PCPU_GET(cpuid), cpu)); 4215 4216 psb = pmc_pcpu[cpu]->pc_sb[ring]; 4217 4218 for (n = 0; n < pmc_nsamples; n++) { /* bound on #iterations */ 4219 4220 ps = psb->ps_read; 4221 if (ps->ps_nsamples == PMC_SAMPLE_FREE) 4222 break; 4223 4224 pm = ps->ps_pmc; 4225 4226 KASSERT(pm->pm_runcount > 0, 4227 ("[pmc,%d] pm=%p runcount %d", __LINE__, (void *) pm, 4228 pm->pm_runcount)); 4229 4230 po = pm->pm_owner; 4231 4232 KASSERT(PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)), 4233 ("[pmc,%d] pmc=%p non-sampling mode=%d", __LINE__, 4234 pm, PMC_TO_MODE(pm))); 4235 4236 /* Ignore PMCs that have been switched off */ 4237 if (pm->pm_state != PMC_STATE_RUNNING) 4238 goto entrydone; 4239 4240 /* If there is a pending AST wait for completion */ 4241 if (ps->ps_nsamples == PMC_SAMPLE_INUSE) { 4242 /* Need a rescan at a later time. */ 4243 CPU_SET_ATOMIC(cpu, &pmc_cpumask); 4244 break; 4245 } 4246 4247 PMCDBG(SAM,OPS,1,"cpu=%d pm=%p n=%d fl=%x wr=%d rd=%d", cpu, 4248 pm, ps->ps_nsamples, ps->ps_flags, 4249 (int) (psb->ps_write - psb->ps_samples), 4250 (int) (psb->ps_read - psb->ps_samples)); 4251 4252 /* 4253 * If this is a process-mode PMC that is attached to 4254 * its owner, and if the PC is in user mode, update 4255 * profiling statistics like timer-based profiling 4256 * would have done. 4257 */ 4258 if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) { 4259 if (ps->ps_flags & PMC_CC_F_USERSPACE) { 4260 td = FIRST_THREAD_IN_PROC(po->po_owner); 4261 addupc_intr(td, ps->ps_pc[0], 1); 4262 } 4263 goto entrydone; 4264 } 4265 4266 /* 4267 * Otherwise, this is either a sampling mode PMC that 4268 * is attached to a different process than its owner, 4269 * or a system-wide sampling PMC. Dispatch a log 4270 * entry to the PMC's owner process. 4271 */ 4272 pmclog_process_callchain(pm, ps); 4273 4274 entrydone: 4275 ps->ps_nsamples = 0; /* mark entry as free */ 4276 atomic_subtract_rel_int(&pm->pm_runcount, 1); 4277 4278 /* increment read pointer, modulo sample size */ 4279 if (++ps == psb->ps_fence) 4280 psb->ps_read = psb->ps_samples; 4281 else 4282 psb->ps_read = ps; 4283 } 4284 4285 atomic_add_int(&pmc_stats.pm_log_sweeps, 1); 4286 4287 /* Do not re-enable stalled PMCs if we failed to process any samples */ 4288 if (n == 0) 4289 return; 4290 4291 /* 4292 * Restart any stalled sampling PMCs on this CPU. 4293 * 4294 * If the NMI handler sets the pm_stalled field of a PMC after 4295 * the check below, we'll end up processing the stalled PMC at 4296 * the next hardclock tick. 4297 */ 4298 for (n = 0; n < md->pmd_npmc; n++) { 4299 pcd = pmc_ri_to_classdep(md, n, &adjri); 4300 KASSERT(pcd != NULL, 4301 ("[pmc,%d] null pcd ri=%d", __LINE__, n)); 4302 (void) (*pcd->pcd_get_config)(cpu,adjri,&pm); 4303 4304 if (pm == NULL || /* !cfg'ed */ 4305 pm->pm_state != PMC_STATE_RUNNING || /* !active */ 4306 !PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)) || /* !sampling */ 4307 pm->pm_stalled == 0) /* !stalled */ 4308 continue; 4309 4310 pm->pm_stalled = 0; 4311 (*pcd->pcd_start_pmc)(cpu, adjri); 4312 } 4313} 4314 4315/* 4316 * Event handlers. 4317 */ 4318 4319/* 4320 * Handle a process exit. 4321 * 4322 * Remove this process from all hash tables. If this process 4323 * owned any PMCs, turn off those PMCs and deallocate them, 4324 * removing any associations with target processes. 4325 * 4326 * This function will be called by the last 'thread' of a 4327 * process. 4328 * 4329 * XXX This eventhandler gets called early in the exit process. 4330 * Consider using a 'hook' invocation from thread_exit() or equivalent 4331 * spot. Another negative is that kse_exit doesn't seem to call 4332 * exit1() [??]. 4333 * 4334 */ 4335 4336static void 4337pmc_process_exit(void *arg __unused, struct proc *p) 4338{ 4339 struct pmc *pm; 4340 int adjri, cpu; 4341 unsigned int ri; 4342 int is_using_hwpmcs; 4343 struct pmc_owner *po; 4344 struct pmc_process *pp; 4345 struct pmc_classdep *pcd; 4346 pmc_value_t newvalue, tmp; 4347 4348 PROC_LOCK(p); 4349 is_using_hwpmcs = p->p_flag & P_HWPMC; 4350 PROC_UNLOCK(p); 4351 4352 /* 4353 * Log a sysexit event to all SS PMC owners. 4354 */ 4355 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 4356 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 4357 pmclog_process_sysexit(po, p->p_pid); 4358 4359 if (!is_using_hwpmcs) 4360 return; 4361 4362 PMC_GET_SX_XLOCK(); 4363 PMCDBG(PRC,EXT,1,"process-exit proc=%p (%d, %s)", p, p->p_pid, 4364 p->p_comm); 4365 4366 /* 4367 * Since this code is invoked by the last thread in an exiting 4368 * process, we would have context switched IN at some prior 4369 * point. However, with PREEMPTION, kernel mode context 4370 * switches may happen any time, so we want to disable a 4371 * context switch OUT till we get any PMCs targetting this 4372 * process off the hardware. 4373 * 4374 * We also need to atomically remove this process' 4375 * entry from our target process hash table, using 4376 * PMC_FLAG_REMOVE. 4377 */ 4378 PMCDBG(PRC,EXT,1, "process-exit proc=%p (%d, %s)", p, p->p_pid, 4379 p->p_comm); 4380 4381 critical_enter(); /* no preemption */ 4382 4383 cpu = curthread->td_oncpu; 4384 4385 if ((pp = pmc_find_process_descriptor(p, 4386 PMC_FLAG_REMOVE)) != NULL) { 4387 4388 PMCDBG(PRC,EXT,2, 4389 "process-exit proc=%p pmc-process=%p", p, pp); 4390 4391 /* 4392 * The exiting process could the target of 4393 * some PMCs which will be running on 4394 * currently executing CPU. 4395 * 4396 * We need to turn these PMCs off like we 4397 * would do at context switch OUT time. 4398 */ 4399 for (ri = 0; ri < md->pmd_npmc; ri++) { 4400 4401 /* 4402 * Pick up the pmc pointer from hardware 4403 * state similar to the CSW_OUT code. 4404 */ 4405 pm = NULL; 4406 4407 pcd = pmc_ri_to_classdep(md, ri, &adjri); 4408 4409 (void) (*pcd->pcd_get_config)(cpu, adjri, &pm); 4410 4411 PMCDBG(PRC,EXT,2, "ri=%d pm=%p", ri, pm); 4412 4413 if (pm == NULL || 4414 !PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) 4415 continue; 4416 4417 PMCDBG(PRC,EXT,2, "ppmcs[%d]=%p pm=%p " 4418 "state=%d", ri, pp->pp_pmcs[ri].pp_pmc, 4419 pm, pm->pm_state); 4420 4421 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 4422 ("[pmc,%d] ri mismatch pmc(%d) ri(%d)", 4423 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 4424 4425 KASSERT(pm == pp->pp_pmcs[ri].pp_pmc, 4426 ("[pmc,%d] pm %p != pp_pmcs[%d] %p", 4427 __LINE__, pm, ri, pp->pp_pmcs[ri].pp_pmc)); 4428 4429 (void) pcd->pcd_stop_pmc(cpu, adjri); 4430 4431 KASSERT(pm->pm_runcount > 0, 4432 ("[pmc,%d] bad runcount ri %d rc %d", 4433 __LINE__, ri, pm->pm_runcount)); 4434 4435 /* Stop hardware only if it is actually running */ 4436 if (pm->pm_state == PMC_STATE_RUNNING && 4437 pm->pm_stalled == 0) { 4438 pcd->pcd_read_pmc(cpu, adjri, &newvalue); 4439 tmp = newvalue - 4440 PMC_PCPU_SAVED(cpu,ri); 4441 4442 mtx_pool_lock_spin(pmc_mtxpool, pm); 4443 pm->pm_gv.pm_savedvalue += tmp; 4444 pp->pp_pmcs[ri].pp_pmcval += tmp; 4445 mtx_pool_unlock_spin(pmc_mtxpool, pm); 4446 } 4447 4448 atomic_subtract_rel_int(&pm->pm_runcount,1); 4449 4450 KASSERT((int) pm->pm_runcount >= 0, 4451 ("[pmc,%d] runcount is %d", __LINE__, ri)); 4452 4453 (void) pcd->pcd_config_pmc(cpu, adjri, NULL); 4454 } 4455 4456 /* 4457 * Inform the MD layer of this pseudo "context switch 4458 * out" 4459 */ 4460 (void) md->pmd_switch_out(pmc_pcpu[cpu], pp); 4461 4462 critical_exit(); /* ok to be pre-empted now */ 4463 4464 /* 4465 * Unlink this process from the PMCs that are 4466 * targetting it. This will send a signal to 4467 * all PMC owner's whose PMCs are orphaned. 4468 * 4469 * Log PMC value at exit time if requested. 4470 */ 4471 for (ri = 0; ri < md->pmd_npmc; ri++) 4472 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) { 4473 if (pm->pm_flags & PMC_F_NEEDS_LOGFILE && 4474 PMC_IS_COUNTING_MODE(PMC_TO_MODE(pm))) 4475 pmclog_process_procexit(pm, pp); 4476 pmc_unlink_target_process(pm, pp); 4477 } 4478 free(pp, M_PMC); 4479 4480 } else 4481 critical_exit(); /* pp == NULL */ 4482 4483 4484 /* 4485 * If the process owned PMCs, free them up and free up 4486 * memory. 4487 */ 4488 if ((po = pmc_find_owner_descriptor(p)) != NULL) { 4489 pmc_remove_owner(po); 4490 pmc_destroy_owner_descriptor(po); 4491 } 4492 4493 sx_xunlock(&pmc_sx); 4494} 4495 4496/* 4497 * Handle a process fork. 4498 * 4499 * If the parent process 'p1' is under HWPMC monitoring, then copy 4500 * over any attached PMCs that have 'do_descendants' semantics. 4501 */ 4502 4503static void 4504pmc_process_fork(void *arg __unused, struct proc *p1, struct proc *newproc, 4505 int flags) 4506{ 4507 int is_using_hwpmcs; 4508 unsigned int ri; 4509 uint32_t do_descendants; 4510 struct pmc *pm; 4511 struct pmc_owner *po; 4512 struct pmc_process *ppnew, *ppold; 4513 4514 (void) flags; /* unused parameter */ 4515 4516 PROC_LOCK(p1); 4517 is_using_hwpmcs = p1->p_flag & P_HWPMC; 4518 PROC_UNLOCK(p1); 4519 4520 /* 4521 * If there are system-wide sampling PMCs active, we need to 4522 * log all fork events to their owner's logs. 4523 */ 4524 4525 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 4526 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 4527 pmclog_process_procfork(po, p1->p_pid, newproc->p_pid); 4528 4529 if (!is_using_hwpmcs) 4530 return; 4531 4532 PMC_GET_SX_XLOCK(); 4533 PMCDBG(PMC,FRK,1, "process-fork proc=%p (%d, %s) -> %p", p1, 4534 p1->p_pid, p1->p_comm, newproc); 4535 4536 /* 4537 * If the parent process (curthread->td_proc) is a 4538 * target of any PMCs, look for PMCs that are to be 4539 * inherited, and link these into the new process 4540 * descriptor. 4541 */ 4542 if ((ppold = pmc_find_process_descriptor(curthread->td_proc, 4543 PMC_FLAG_NONE)) == NULL) 4544 goto done; /* nothing to do */ 4545 4546 do_descendants = 0; 4547 for (ri = 0; ri < md->pmd_npmc; ri++) 4548 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL) 4549 do_descendants |= pm->pm_flags & PMC_F_DESCENDANTS; 4550 if (do_descendants == 0) /* nothing to do */ 4551 goto done; 4552 4553 /* allocate a descriptor for the new process */ 4554 if ((ppnew = pmc_find_process_descriptor(newproc, 4555 PMC_FLAG_ALLOCATE)) == NULL) 4556 goto done; 4557 4558 /* 4559 * Run through all PMCs that were targeting the old process 4560 * and which specified F_DESCENDANTS and attach them to the 4561 * new process. 4562 * 4563 * Log the fork event to all owners of PMCs attached to this 4564 * process, if not already logged. 4565 */ 4566 for (ri = 0; ri < md->pmd_npmc; ri++) 4567 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL && 4568 (pm->pm_flags & PMC_F_DESCENDANTS)) { 4569 pmc_link_target_process(pm, ppnew); 4570 po = pm->pm_owner; 4571 if (po->po_sscount == 0 && 4572 po->po_flags & PMC_PO_OWNS_LOGFILE) 4573 pmclog_process_procfork(po, p1->p_pid, 4574 newproc->p_pid); 4575 } 4576 4577 /* 4578 * Now mark the new process as being tracked by this driver. 4579 */ 4580 PROC_LOCK(newproc); 4581 newproc->p_flag |= P_HWPMC; 4582 PROC_UNLOCK(newproc); 4583 4584 done: 4585 sx_xunlock(&pmc_sx); 4586} 4587 4588static void 4589pmc_kld_load(void *arg __unused, linker_file_t lf) 4590{ 4591 struct pmc_owner *po; 4592 4593 sx_slock(&pmc_sx); 4594 4595 /* 4596 * Notify owners of system sampling PMCs about KLD operations. 4597 */ 4598 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 4599 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 4600 pmclog_process_map_in(po, (pid_t) -1, 4601 (uintfptr_t) lf->address, lf->filename); 4602 4603 /* 4604 * TODO: Notify owners of (all) process-sampling PMCs too. 4605 */ 4606 4607 sx_sunlock(&pmc_sx); 4608} 4609 4610static void 4611pmc_kld_unload(void *arg __unused, const char *filename __unused, 4612 caddr_t address, size_t size) 4613{ 4614 struct pmc_owner *po; 4615 4616 sx_slock(&pmc_sx); 4617 4618 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 4619 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 4620 pmclog_process_map_out(po, (pid_t) -1, 4621 (uintfptr_t) address, (uintfptr_t) address + size); 4622 4623 /* 4624 * TODO: Notify owners of process-sampling PMCs. 4625 */ 4626 4627 sx_sunlock(&pmc_sx); 4628} 4629 4630/* 4631 * initialization 4632 */ 4633 4634static const char *pmc_name_of_pmcclass[] = { 4635#undef __PMC_CLASS 4636#define __PMC_CLASS(N) #N , 4637 __PMC_CLASSES() 4638}; 4639 4640/* 4641 * Base class initializer: allocate structure and set default classes. 4642 */ 4643struct pmc_mdep * 4644pmc_mdep_alloc(int nclasses) 4645{ 4646 struct pmc_mdep *md; 4647 int n; 4648 4649 /* SOFT + md classes */ 4650 n = 1 + nclasses; 4651 md = malloc(sizeof(struct pmc_mdep) + n * 4652 sizeof(struct pmc_classdep), M_PMC, M_WAITOK|M_ZERO); 4653 md->pmd_nclass = n; 4654 4655 /* Add base class. */ 4656 pmc_soft_initialize(md); 4657 return md; 4658} 4659 4660void 4661pmc_mdep_free(struct pmc_mdep *md) 4662{ 4663 pmc_soft_finalize(md); 4664 free(md, M_PMC); 4665} 4666 4667static int 4668generic_switch_in(struct pmc_cpu *pc, struct pmc_process *pp) 4669{ 4670 (void) pc; (void) pp; 4671 4672 return (0); 4673} 4674 4675static int 4676generic_switch_out(struct pmc_cpu *pc, struct pmc_process *pp) 4677{ 4678 (void) pc; (void) pp; 4679 4680 return (0); 4681} 4682 4683static struct pmc_mdep * 4684pmc_generic_cpu_initialize(void) 4685{ 4686 struct pmc_mdep *md; 4687 4688 md = pmc_mdep_alloc(0); 4689 4690 md->pmd_cputype = PMC_CPU_GENERIC; 4691 4692 md->pmd_pcpu_init = NULL; 4693 md->pmd_pcpu_fini = NULL; 4694 md->pmd_switch_in = generic_switch_in; 4695 md->pmd_switch_out = generic_switch_out; 4696 4697 return (md); 4698} 4699 4700static void 4701pmc_generic_cpu_finalize(struct pmc_mdep *md) 4702{ 4703 (void) md; 4704} 4705 4706 4707static int 4708pmc_initialize(void) 4709{ 4710 int c, cpu, error, n, ri; 4711 unsigned int maxcpu; 4712 struct pmc_binding pb; 4713 struct pmc_sample *ps; 4714 struct pmc_classdep *pcd; 4715 struct pmc_samplebuffer *sb; 4716 4717 md = NULL; 4718 error = 0; 4719 4720#ifdef DEBUG 4721 /* parse debug flags first */ 4722 if (TUNABLE_STR_FETCH(PMC_SYSCTL_NAME_PREFIX "debugflags", 4723 pmc_debugstr, sizeof(pmc_debugstr))) 4724 pmc_debugflags_parse(pmc_debugstr, 4725 pmc_debugstr+strlen(pmc_debugstr)); 4726#endif 4727 4728 PMCDBG(MOD,INI,0, "PMC Initialize (version %x)", PMC_VERSION); 4729 4730 /* check kernel version */ 4731 if (pmc_kernel_version != PMC_VERSION) { 4732 if (pmc_kernel_version == 0) 4733 printf("hwpmc: this kernel has not been compiled with " 4734 "'options HWPMC_HOOKS'.\n"); 4735 else 4736 printf("hwpmc: kernel version (0x%x) does not match " 4737 "module version (0x%x).\n", pmc_kernel_version, 4738 PMC_VERSION); 4739 return EPROGMISMATCH; 4740 } 4741 4742 /* 4743 * check sysctl parameters 4744 */ 4745 4746 if (pmc_hashsize <= 0) { 4747 (void) printf("hwpmc: tunable \"hashsize\"=%d must be " 4748 "greater than zero.\n", pmc_hashsize); 4749 pmc_hashsize = PMC_HASH_SIZE; 4750 } 4751 4752 if (pmc_nsamples <= 0 || pmc_nsamples > 65535) { 4753 (void) printf("hwpmc: tunable \"nsamples\"=%d out of " 4754 "range.\n", pmc_nsamples); 4755 pmc_nsamples = PMC_NSAMPLES; 4756 } 4757 4758 if (pmc_callchaindepth <= 0 || 4759 pmc_callchaindepth > PMC_CALLCHAIN_DEPTH_MAX) { 4760 (void) printf("hwpmc: tunable \"callchaindepth\"=%d out of " 4761 "range - using %d.\n", pmc_callchaindepth, 4762 PMC_CALLCHAIN_DEPTH_MAX); 4763 pmc_callchaindepth = PMC_CALLCHAIN_DEPTH_MAX; 4764 } 4765 4766 md = pmc_md_initialize(); 4767 if (md == NULL) { 4768 /* Default to generic CPU. */ 4769 md = pmc_generic_cpu_initialize(); 4770 if (md == NULL) 4771 return (ENOSYS); 4772 } 4773 4774 KASSERT(md->pmd_nclass >= 1 && md->pmd_npmc >= 1, 4775 ("[pmc,%d] no classes or pmcs", __LINE__)); 4776 4777 /* Compute the map from row-indices to classdep pointers. */ 4778 pmc_rowindex_to_classdep = malloc(sizeof(struct pmc_classdep *) * 4779 md->pmd_npmc, M_PMC, M_WAITOK|M_ZERO); 4780 4781 for (n = 0; n < md->pmd_npmc; n++) 4782 pmc_rowindex_to_classdep[n] = NULL; 4783 for (ri = c = 0; c < md->pmd_nclass; c++) { 4784 pcd = &md->pmd_classdep[c]; 4785 for (n = 0; n < pcd->pcd_num; n++, ri++) 4786 pmc_rowindex_to_classdep[ri] = pcd; 4787 } 4788 4789 KASSERT(ri == md->pmd_npmc, 4790 ("[pmc,%d] npmc miscomputed: ri=%d, md->npmc=%d", __LINE__, 4791 ri, md->pmd_npmc)); 4792 4793 maxcpu = pmc_cpu_max(); 4794 4795 /* allocate space for the per-cpu array */ 4796 pmc_pcpu = malloc(maxcpu * sizeof(struct pmc_cpu *), M_PMC, 4797 M_WAITOK|M_ZERO); 4798 4799 /* per-cpu 'saved values' for managing process-mode PMCs */ 4800 pmc_pcpu_saved = malloc(sizeof(pmc_value_t) * maxcpu * md->pmd_npmc, 4801 M_PMC, M_WAITOK); 4802 4803 /* Perform CPU-dependent initialization. */ 4804 pmc_save_cpu_binding(&pb); 4805 error = 0; 4806 for (cpu = 0; error == 0 && cpu < maxcpu; cpu++) { 4807 if (!pmc_cpu_is_active(cpu)) 4808 continue; 4809 pmc_select_cpu(cpu); 4810 pmc_pcpu[cpu] = malloc(sizeof(struct pmc_cpu) + 4811 md->pmd_npmc * sizeof(struct pmc_hw *), M_PMC, 4812 M_WAITOK|M_ZERO); 4813 if (md->pmd_pcpu_init) 4814 error = md->pmd_pcpu_init(md, cpu); 4815 for (n = 0; error == 0 && n < md->pmd_nclass; n++) 4816 error = md->pmd_classdep[n].pcd_pcpu_init(md, cpu); 4817 } 4818 pmc_restore_cpu_binding(&pb); 4819 4820 if (error) 4821 return (error); 4822 4823 /* allocate space for the sample array */ 4824 for (cpu = 0; cpu < maxcpu; cpu++) { 4825 if (!pmc_cpu_is_active(cpu)) 4826 continue; 4827 4828 sb = malloc(sizeof(struct pmc_samplebuffer) + 4829 pmc_nsamples * sizeof(struct pmc_sample), M_PMC, 4830 M_WAITOK|M_ZERO); 4831 sb->ps_read = sb->ps_write = sb->ps_samples; 4832 sb->ps_fence = sb->ps_samples + pmc_nsamples; 4833 4834 KASSERT(pmc_pcpu[cpu] != NULL, 4835 ("[pmc,%d] cpu=%d Null per-cpu data", __LINE__, cpu)); 4836 4837 sb->ps_callchains = malloc(pmc_callchaindepth * pmc_nsamples * 4838 sizeof(uintptr_t), M_PMC, M_WAITOK|M_ZERO); 4839 4840 for (n = 0, ps = sb->ps_samples; n < pmc_nsamples; n++, ps++) 4841 ps->ps_pc = sb->ps_callchains + 4842 (n * pmc_callchaindepth); 4843 4844 pmc_pcpu[cpu]->pc_sb[PMC_HR] = sb; 4845 4846 sb = malloc(sizeof(struct pmc_samplebuffer) + 4847 pmc_nsamples * sizeof(struct pmc_sample), M_PMC, 4848 M_WAITOK|M_ZERO); 4849 sb->ps_read = sb->ps_write = sb->ps_samples; 4850 sb->ps_fence = sb->ps_samples + pmc_nsamples; 4851 4852 KASSERT(pmc_pcpu[cpu] != NULL, 4853 ("[pmc,%d] cpu=%d Null per-cpu data", __LINE__, cpu)); 4854 4855 sb->ps_callchains = malloc(pmc_callchaindepth * pmc_nsamples * 4856 sizeof(uintptr_t), M_PMC, M_WAITOK|M_ZERO); 4857 4858 for (n = 0, ps = sb->ps_samples; n < pmc_nsamples; n++, ps++) 4859 ps->ps_pc = sb->ps_callchains + 4860 (n * pmc_callchaindepth); 4861 4862 pmc_pcpu[cpu]->pc_sb[PMC_SR] = sb; 4863 } 4864 4865 /* allocate space for the row disposition array */ 4866 pmc_pmcdisp = malloc(sizeof(enum pmc_mode) * md->pmd_npmc, 4867 M_PMC, M_WAITOK|M_ZERO); 4868 4869 /* mark all PMCs as available */ 4870 for (n = 0; n < (int) md->pmd_npmc; n++) 4871 PMC_MARK_ROW_FREE(n); 4872 4873 /* allocate thread hash tables */ 4874 pmc_ownerhash = hashinit(pmc_hashsize, M_PMC, 4875 &pmc_ownerhashmask); 4876 4877 pmc_processhash = hashinit(pmc_hashsize, M_PMC, 4878 &pmc_processhashmask); 4879 mtx_init(&pmc_processhash_mtx, "pmc-process-hash", "pmc-leaf", 4880 MTX_SPIN); 4881 4882 LIST_INIT(&pmc_ss_owners); 4883 pmc_ss_count = 0; 4884 4885 /* allocate a pool of spin mutexes */ 4886 pmc_mtxpool = mtx_pool_create("pmc-leaf", pmc_mtxpool_size, 4887 MTX_SPIN); 4888 4889 PMCDBG(MOD,INI,1, "pmc_ownerhash=%p, mask=0x%lx " 4890 "targethash=%p mask=0x%lx", pmc_ownerhash, pmc_ownerhashmask, 4891 pmc_processhash, pmc_processhashmask); 4892 4893 /* register process {exit,fork,exec} handlers */ 4894 pmc_exit_tag = EVENTHANDLER_REGISTER(process_exit, 4895 pmc_process_exit, NULL, EVENTHANDLER_PRI_ANY); 4896 pmc_fork_tag = EVENTHANDLER_REGISTER(process_fork, 4897 pmc_process_fork, NULL, EVENTHANDLER_PRI_ANY); 4898 4899 /* register kld event handlers */ 4900 pmc_kld_load_tag = EVENTHANDLER_REGISTER(kld_load, pmc_kld_load, 4901 NULL, EVENTHANDLER_PRI_ANY); 4902 pmc_kld_unload_tag = EVENTHANDLER_REGISTER(kld_unload, pmc_kld_unload, 4903 NULL, EVENTHANDLER_PRI_ANY); 4904 4905 /* initialize logging */ 4906 pmclog_initialize(); 4907 4908 /* set hook functions */ 4909 pmc_intr = md->pmd_intr; 4910 pmc_hook = pmc_hook_handler; 4911 4912 if (error == 0) { 4913 printf(PMC_MODULE_NAME ":"); 4914 for (n = 0; n < (int) md->pmd_nclass; n++) { 4915 pcd = &md->pmd_classdep[n]; 4916 printf(" %s/%d/%d/0x%b", 4917 pmc_name_of_pmcclass[pcd->pcd_class], 4918 pcd->pcd_num, 4919 pcd->pcd_width, 4920 pcd->pcd_caps, 4921 "\20" 4922 "\1INT\2USR\3SYS\4EDG\5THR" 4923 "\6REA\7WRI\10INV\11QUA\12PRC" 4924 "\13TAG\14CSC"); 4925 } 4926 printf("\n"); 4927 } 4928 4929 return (error); 4930} 4931 4932/* prepare to be unloaded */ 4933static void 4934pmc_cleanup(void) 4935{ 4936 int c, cpu; 4937 unsigned int maxcpu; 4938 struct pmc_ownerhash *ph; 4939 struct pmc_owner *po, *tmp; 4940 struct pmc_binding pb; 4941#ifdef DEBUG 4942 struct pmc_processhash *prh; 4943#endif 4944 4945 PMCDBG(MOD,INI,0, "%s", "cleanup"); 4946 4947 /* switch off sampling */ 4948 CPU_ZERO(&pmc_cpumask); 4949 pmc_intr = NULL; 4950 4951 sx_xlock(&pmc_sx); 4952 if (pmc_hook == NULL) { /* being unloaded already */ 4953 sx_xunlock(&pmc_sx); 4954 return; 4955 } 4956 4957 pmc_hook = NULL; /* prevent new threads from entering module */ 4958 4959 /* deregister event handlers */ 4960 EVENTHANDLER_DEREGISTER(process_fork, pmc_fork_tag); 4961 EVENTHANDLER_DEREGISTER(process_exit, pmc_exit_tag); 4962 EVENTHANDLER_DEREGISTER(kld_load, pmc_kld_load_tag); 4963 EVENTHANDLER_DEREGISTER(kld_unload, pmc_kld_unload_tag); 4964 4965 /* send SIGBUS to all owner threads, free up allocations */ 4966 if (pmc_ownerhash) 4967 for (ph = pmc_ownerhash; 4968 ph <= &pmc_ownerhash[pmc_ownerhashmask]; 4969 ph++) { 4970 LIST_FOREACH_SAFE(po, ph, po_next, tmp) { 4971 pmc_remove_owner(po); 4972 4973 /* send SIGBUS to owner processes */ 4974 PMCDBG(MOD,INI,2, "cleanup signal proc=%p " 4975 "(%d, %s)", po->po_owner, 4976 po->po_owner->p_pid, 4977 po->po_owner->p_comm); 4978 4979 PROC_LOCK(po->po_owner); 4980 kern_psignal(po->po_owner, SIGBUS); 4981 PROC_UNLOCK(po->po_owner); 4982 4983 pmc_destroy_owner_descriptor(po); 4984 } 4985 } 4986 4987 /* reclaim allocated data structures */ 4988 if (pmc_mtxpool) 4989 mtx_pool_destroy(&pmc_mtxpool); 4990 4991 mtx_destroy(&pmc_processhash_mtx); 4992 if (pmc_processhash) { 4993#ifdef DEBUG 4994 struct pmc_process *pp; 4995 4996 PMCDBG(MOD,INI,3, "%s", "destroy process hash"); 4997 for (prh = pmc_processhash; 4998 prh <= &pmc_processhash[pmc_processhashmask]; 4999 prh++) 5000 LIST_FOREACH(pp, prh, pp_next) 5001 PMCDBG(MOD,INI,3, "pid=%d", pp->pp_proc->p_pid); 5002#endif 5003 5004 hashdestroy(pmc_processhash, M_PMC, pmc_processhashmask); 5005 pmc_processhash = NULL; 5006 } 5007 5008 if (pmc_ownerhash) { 5009 PMCDBG(MOD,INI,3, "%s", "destroy owner hash"); 5010 hashdestroy(pmc_ownerhash, M_PMC, pmc_ownerhashmask); 5011 pmc_ownerhash = NULL; 5012 } 5013 5014 KASSERT(LIST_EMPTY(&pmc_ss_owners), 5015 ("[pmc,%d] Global SS owner list not empty", __LINE__)); 5016 KASSERT(pmc_ss_count == 0, 5017 ("[pmc,%d] Global SS count not empty", __LINE__)); 5018 5019 /* do processor and pmc-class dependent cleanup */ 5020 maxcpu = pmc_cpu_max(); 5021 5022 PMCDBG(MOD,INI,3, "%s", "md cleanup"); 5023 if (md) { 5024 pmc_save_cpu_binding(&pb); 5025 for (cpu = 0; cpu < maxcpu; cpu++) { 5026 PMCDBG(MOD,INI,1,"pmc-cleanup cpu=%d pcs=%p", 5027 cpu, pmc_pcpu[cpu]); 5028 if (!pmc_cpu_is_active(cpu) || pmc_pcpu[cpu] == NULL) 5029 continue; 5030 pmc_select_cpu(cpu); 5031 for (c = 0; c < md->pmd_nclass; c++) 5032 md->pmd_classdep[c].pcd_pcpu_fini(md, cpu); 5033 if (md->pmd_pcpu_fini) 5034 md->pmd_pcpu_fini(md, cpu); 5035 } 5036 5037 if (md->pmd_cputype == PMC_CPU_GENERIC) 5038 pmc_generic_cpu_finalize(md); 5039 else 5040 pmc_md_finalize(md); 5041 5042 pmc_mdep_free(md); 5043 md = NULL; 5044 pmc_restore_cpu_binding(&pb); 5045 } 5046 5047 /* Free per-cpu descriptors. */ 5048 for (cpu = 0; cpu < maxcpu; cpu++) { 5049 if (!pmc_cpu_is_active(cpu)) 5050 continue; 5051 KASSERT(pmc_pcpu[cpu]->pc_sb[PMC_HR] != NULL, 5052 ("[pmc,%d] Null hw cpu sample buffer cpu=%d", __LINE__, 5053 cpu)); 5054 KASSERT(pmc_pcpu[cpu]->pc_sb[PMC_SR] != NULL, 5055 ("[pmc,%d] Null sw cpu sample buffer cpu=%d", __LINE__, 5056 cpu)); 5057 free(pmc_pcpu[cpu]->pc_sb[PMC_HR]->ps_callchains, M_PMC); 5058 free(pmc_pcpu[cpu]->pc_sb[PMC_HR], M_PMC); 5059 free(pmc_pcpu[cpu]->pc_sb[PMC_SR]->ps_callchains, M_PMC); 5060 free(pmc_pcpu[cpu]->pc_sb[PMC_SR], M_PMC); 5061 free(pmc_pcpu[cpu], M_PMC); 5062 } 5063 5064 free(pmc_pcpu, M_PMC); 5065 pmc_pcpu = NULL; 5066 5067 free(pmc_pcpu_saved, M_PMC); 5068 pmc_pcpu_saved = NULL; 5069 5070 if (pmc_pmcdisp) { 5071 free(pmc_pmcdisp, M_PMC); 5072 pmc_pmcdisp = NULL; 5073 } 5074 5075 if (pmc_rowindex_to_classdep) { 5076 free(pmc_rowindex_to_classdep, M_PMC); 5077 pmc_rowindex_to_classdep = NULL; 5078 } 5079 5080 pmclog_shutdown(); 5081 5082 sx_xunlock(&pmc_sx); /* we are done */ 5083} 5084 5085/* 5086 * The function called at load/unload. 5087 */ 5088 5089static int 5090load (struct module *module __unused, int cmd, void *arg __unused) 5091{ 5092 int error; 5093 5094 error = 0; 5095 5096 switch (cmd) { 5097 case MOD_LOAD : 5098 /* initialize the subsystem */ 5099 error = pmc_initialize(); 5100 if (error != 0) 5101 break; 5102 PMCDBG(MOD,INI,1, "syscall=%d maxcpu=%d", 5103 pmc_syscall_num, pmc_cpu_max()); 5104 break; 5105 5106 5107 case MOD_UNLOAD : 5108 case MOD_SHUTDOWN: 5109 pmc_cleanup(); 5110 PMCDBG(MOD,INI,1, "%s", "unloaded"); 5111 break; 5112 5113 default : 5114 error = EINVAL; /* XXX should panic(9) */ 5115 break; 5116 } 5117 5118 return error; 5119} 5120 5121/* memory pool */ 5122MALLOC_DEFINE(M_PMC, "pmc", "Memory space for the PMC module"); 5123