hwpmc_mod.c revision 294046
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 294046 2016-01-14 22:02:21Z jtl $"); 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 HWPMC_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 HWPMC_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 HWPMC_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 PMCDBG0(CPU,BND,2, "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 PMCDBG1(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 PMCDBG2(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 PMCDBG0(CPU,BND,2, "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 PMCDBG1(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 PMCDBG1(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 PMCDBG1(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 PMCDBG1(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 PMCDBG1(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 PMCDBG3(PRC,TLK,1, "link-target pmc=%p ri=%d pmc-process=%p", 822 pm, ri, pp); 823 824#ifdef HWPMC_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 PMCDBG3(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 PMCDBG2(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 PMCDBG5(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 PMCDBG5(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 PMCDBG6(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 PMCDBG5(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 PMCDBG5(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 1291 /* 1292 * Use the saved value calculated after the most recent 1293 * thread switch out to start this counter. Reset 1294 * the saved count in case another thread from this 1295 * process switches in before any threads switch out. 1296 */ 1297 newvalue = PMC_PCPU_SAVED(cpu,ri) = 1298 pp->pp_pmcs[ri].pp_pmcval; 1299 pp->pp_pmcs[ri].pp_pmcval = pm->pm_sc.pm_reloadcount; 1300 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1301 } else { 1302 KASSERT(PMC_TO_MODE(pm) == PMC_MODE_TC, 1303 ("[pmc,%d] illegal mode=%d", __LINE__, 1304 PMC_TO_MODE(pm))); 1305 mtx_pool_lock_spin(pmc_mtxpool, pm); 1306 newvalue = PMC_PCPU_SAVED(cpu, ri) = 1307 pm->pm_gv.pm_savedvalue; 1308 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1309 } 1310 1311 PMCDBG3(CSW,SWI,1,"cpu=%d ri=%d new=%jd", cpu, ri, newvalue); 1312 1313 pcd->pcd_write_pmc(cpu, adjri, newvalue); 1314 1315 /* If a sampling mode PMC, reset stalled state. */ 1316 if (PMC_TO_MODE(pm) == PMC_MODE_TS) 1317 CPU_CLR_ATOMIC(cpu, &pm->pm_stalled); 1318 1319 /* Indicate that we desire this to run. */ 1320 CPU_SET_ATOMIC(cpu, &pm->pm_cpustate); 1321 1322 /* Start the PMC. */ 1323 pcd->pcd_start_pmc(cpu, adjri); 1324 } 1325 1326 /* 1327 * perform any other architecture/cpu dependent thread 1328 * switch-in actions. 1329 */ 1330 1331 (void) (*md->pmd_switch_in)(pc, pp); 1332 1333 critical_exit(); 1334 1335} 1336 1337/* 1338 * Thread context switch OUT. 1339 */ 1340 1341static void 1342pmc_process_csw_out(struct thread *td) 1343{ 1344 int cpu; 1345 int64_t tmp; 1346 struct pmc *pm; 1347 struct proc *p; 1348 enum pmc_mode mode; 1349 struct pmc_cpu *pc; 1350 pmc_value_t newvalue; 1351 unsigned int adjri, ri; 1352 struct pmc_process *pp; 1353 struct pmc_classdep *pcd; 1354 1355 1356 /* 1357 * Locate our process descriptor; this may be NULL if 1358 * this process is exiting and we have already removed 1359 * the process from the target process table. 1360 * 1361 * Note that due to kernel preemption, multiple 1362 * context switches may happen while the process is 1363 * exiting. 1364 * 1365 * Note also that if the target process cannot be 1366 * found we still need to deconfigure any PMCs that 1367 * are currently running on hardware. 1368 */ 1369 1370 p = td->td_proc; 1371 pp = pmc_find_process_descriptor(p, PMC_FLAG_NONE); 1372 1373 /* 1374 * save PMCs 1375 */ 1376 1377 critical_enter(); 1378 1379 cpu = PCPU_GET(cpuid); /* td->td_oncpu is invalid */ 1380 1381 PMCDBG5(CSW,SWO,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p, 1382 p->p_pid, p->p_comm, pp); 1383 1384 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 1385 ("[pmc,%d wierd CPU id %d", __LINE__, cpu)); 1386 1387 pc = pmc_pcpu[cpu]; 1388 1389 /* 1390 * When a PMC gets unlinked from a target PMC, it will 1391 * be removed from the target's pp_pmc[] array. 1392 * 1393 * However, on a MP system, the target could have been 1394 * executing on another CPU at the time of the unlink. 1395 * So, at context switch OUT time, we need to look at 1396 * the hardware to determine if a PMC is scheduled on 1397 * it. 1398 */ 1399 1400 for (ri = 0; ri < md->pmd_npmc; ri++) { 1401 1402 pcd = pmc_ri_to_classdep(md, ri, &adjri); 1403 pm = NULL; 1404 (void) (*pcd->pcd_get_config)(cpu, adjri, &pm); 1405 1406 if (pm == NULL) /* nothing at this row index */ 1407 continue; 1408 1409 mode = PMC_TO_MODE(pm); 1410 if (!PMC_IS_VIRTUAL_MODE(mode)) 1411 continue; /* not a process virtual PMC */ 1412 1413 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 1414 ("[pmc,%d] ri mismatch pmc(%d) ri(%d)", 1415 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 1416 1417 /* 1418 * Change desired state, and then stop if not stalled. 1419 * This two-step dance should avoid race conditions where 1420 * an interrupt re-enables the PMC after this code has 1421 * already checked the pm_stalled flag. 1422 */ 1423 CPU_CLR_ATOMIC(cpu, &pm->pm_cpustate); 1424 if (!CPU_ISSET(cpu, &pm->pm_stalled)) 1425 pcd->pcd_stop_pmc(cpu, adjri); 1426 1427 /* reduce this PMC's runcount */ 1428 atomic_subtract_rel_int(&pm->pm_runcount, 1); 1429 1430 /* 1431 * If this PMC is associated with this process, 1432 * save the reading. 1433 */ 1434 1435 if (pp != NULL && pp->pp_pmcs[ri].pp_pmc != NULL) { 1436 1437 KASSERT(pm == pp->pp_pmcs[ri].pp_pmc, 1438 ("[pmc,%d] pm %p != pp_pmcs[%d] %p", __LINE__, 1439 pm, ri, pp->pp_pmcs[ri].pp_pmc)); 1440 1441 KASSERT(pp->pp_refcnt > 0, 1442 ("[pmc,%d] pp refcnt = %d", __LINE__, 1443 pp->pp_refcnt)); 1444 1445 pcd->pcd_read_pmc(cpu, adjri, &newvalue); 1446 1447 if (mode == PMC_MODE_TS) { 1448 PMCDBG3(CSW,SWO,1,"cpu=%d ri=%d tmp=%jd (samp)", 1449 cpu, ri, PMC_PCPU_SAVED(cpu,ri) - newvalue); 1450 1451 /* 1452 * For sampling process-virtual PMCs, 1453 * newvalue is the number of events to be seen 1454 * until the next sampling interrupt. 1455 * We can just add the events left from this 1456 * invocation to the counter, then adjust 1457 * in case we overflow our range. 1458 * 1459 * (Recall that we reload the counter every 1460 * time we use it.) 1461 */ 1462 mtx_pool_lock_spin(pmc_mtxpool, pm); 1463 1464 pp->pp_pmcs[ri].pp_pmcval += newvalue; 1465 if (pp->pp_pmcs[ri].pp_pmcval > 1466 pm->pm_sc.pm_reloadcount) 1467 pp->pp_pmcs[ri].pp_pmcval -= 1468 pm->pm_sc.pm_reloadcount; 1469 KASSERT(pp->pp_pmcs[ri].pp_pmcval > 0 && 1470 pp->pp_pmcs[ri].pp_pmcval <= 1471 pm->pm_sc.pm_reloadcount, 1472 ("[pmc,%d] pp_pmcval outside of expected " 1473 "range cpu=%d ri=%d pp_pmcval=%jx " 1474 "pm_reloadcount=%jx", __LINE__, cpu, ri, 1475 pp->pp_pmcs[ri].pp_pmcval, 1476 pm->pm_sc.pm_reloadcount)); 1477 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1478 1479 } else { 1480 tmp = newvalue - PMC_PCPU_SAVED(cpu,ri); 1481 1482 PMCDBG3(CSW,SWO,1,"cpu=%d ri=%d tmp=%jd (count)", 1483 cpu, ri, tmp); 1484 1485 /* 1486 * For counting process-virtual PMCs, 1487 * we expect the count to be 1488 * increasing monotonically, modulo a 64 1489 * bit wraparound. 1490 */ 1491 KASSERT((int64_t) tmp >= 0, 1492 ("[pmc,%d] negative increment cpu=%d " 1493 "ri=%d newvalue=%jx saved=%jx " 1494 "incr=%jx", __LINE__, cpu, ri, 1495 newvalue, PMC_PCPU_SAVED(cpu,ri), tmp)); 1496 1497 mtx_pool_lock_spin(pmc_mtxpool, pm); 1498 pm->pm_gv.pm_savedvalue += tmp; 1499 pp->pp_pmcs[ri].pp_pmcval += tmp; 1500 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1501 1502 if (pm->pm_flags & PMC_F_LOG_PROCCSW) 1503 pmclog_process_proccsw(pm, pp, tmp); 1504 } 1505 } 1506 1507 /* mark hardware as free */ 1508 pcd->pcd_config_pmc(cpu, adjri, NULL); 1509 } 1510 1511 /* 1512 * perform any other architecture/cpu dependent thread 1513 * switch out functions. 1514 */ 1515 1516 (void) (*md->pmd_switch_out)(pc, pp); 1517 1518 critical_exit(); 1519} 1520 1521/* 1522 * A mapping change for a process. 1523 */ 1524 1525static void 1526pmc_process_mmap(struct thread *td, struct pmckern_map_in *pkm) 1527{ 1528 int ri; 1529 pid_t pid; 1530 char *fullpath, *freepath; 1531 const struct pmc *pm; 1532 struct pmc_owner *po; 1533 const struct pmc_process *pp; 1534 1535 freepath = fullpath = NULL; 1536 pmc_getfilename((struct vnode *) pkm->pm_file, &fullpath, &freepath); 1537 1538 pid = td->td_proc->p_pid; 1539 1540 /* Inform owners of all system-wide sampling PMCs. */ 1541 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1542 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1543 pmclog_process_map_in(po, pid, pkm->pm_address, fullpath); 1544 1545 if ((pp = pmc_find_process_descriptor(td->td_proc, 0)) == NULL) 1546 goto done; 1547 1548 /* 1549 * Inform sampling PMC owners tracking this process. 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_in(pm->pm_owner, 1555 pid, pkm->pm_address, fullpath); 1556 1557 done: 1558 if (freepath) 1559 free(freepath, M_TEMP); 1560} 1561 1562 1563/* 1564 * Log an munmap request. 1565 */ 1566 1567static void 1568pmc_process_munmap(struct thread *td, struct pmckern_map_out *pkm) 1569{ 1570 int ri; 1571 pid_t pid; 1572 struct pmc_owner *po; 1573 const struct pmc *pm; 1574 const struct pmc_process *pp; 1575 1576 pid = td->td_proc->p_pid; 1577 1578 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1579 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1580 pmclog_process_map_out(po, pid, pkm->pm_address, 1581 pkm->pm_address + pkm->pm_size); 1582 1583 if ((pp = pmc_find_process_descriptor(td->td_proc, 0)) == NULL) 1584 return; 1585 1586 for (ri = 0; ri < md->pmd_npmc; ri++) 1587 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL && 1588 PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 1589 pmclog_process_map_out(pm->pm_owner, pid, 1590 pkm->pm_address, pkm->pm_address + pkm->pm_size); 1591} 1592 1593/* 1594 * Log mapping information about the kernel. 1595 */ 1596 1597static void 1598pmc_log_kernel_mappings(struct pmc *pm) 1599{ 1600 struct pmc_owner *po; 1601 struct pmckern_map_in *km, *kmbase; 1602 1603 sx_assert(&pmc_sx, SX_LOCKED); 1604 KASSERT(PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)), 1605 ("[pmc,%d] non-sampling PMC (%p) desires mapping information", 1606 __LINE__, (void *) pm)); 1607 1608 po = pm->pm_owner; 1609 1610 if (po->po_flags & PMC_PO_INITIAL_MAPPINGS_DONE) 1611 return; 1612 1613 /* 1614 * Log the current set of kernel modules. 1615 */ 1616 kmbase = linker_hwpmc_list_objects(); 1617 for (km = kmbase; km->pm_file != NULL; km++) { 1618 PMCDBG2(LOG,REG,1,"%s %p", (char *) km->pm_file, 1619 (void *) km->pm_address); 1620 pmclog_process_map_in(po, (pid_t) -1, km->pm_address, 1621 km->pm_file); 1622 } 1623 free(kmbase, M_LINKER); 1624 1625 po->po_flags |= PMC_PO_INITIAL_MAPPINGS_DONE; 1626} 1627 1628/* 1629 * Log the mappings for a single process. 1630 */ 1631 1632static void 1633pmc_log_process_mappings(struct pmc_owner *po, struct proc *p) 1634{ 1635 vm_map_t map; 1636 struct vnode *vp; 1637 struct vmspace *vm; 1638 vm_map_entry_t entry; 1639 vm_offset_t last_end; 1640 u_int last_timestamp; 1641 struct vnode *last_vp; 1642 vm_offset_t start_addr; 1643 vm_object_t obj, lobj, tobj; 1644 char *fullpath, *freepath; 1645 1646 last_vp = NULL; 1647 last_end = (vm_offset_t) 0; 1648 fullpath = freepath = NULL; 1649 1650 if ((vm = vmspace_acquire_ref(p)) == NULL) 1651 return; 1652 1653 map = &vm->vm_map; 1654 vm_map_lock_read(map); 1655 1656 for (entry = map->header.next; entry != &map->header; entry = entry->next) { 1657 1658 if (entry == NULL) { 1659 PMCDBG2(LOG,OPS,2, "hwpmc: vm_map entry unexpectedly " 1660 "NULL! pid=%d vm_map=%p\n", p->p_pid, map); 1661 break; 1662 } 1663 1664 /* 1665 * We only care about executable map entries. 1666 */ 1667 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) || 1668 !(entry->protection & VM_PROT_EXECUTE) || 1669 (entry->object.vm_object == NULL)) { 1670 continue; 1671 } 1672 1673 obj = entry->object.vm_object; 1674 VM_OBJECT_RLOCK(obj); 1675 1676 /* 1677 * Walk the backing_object list to find the base 1678 * (non-shadowed) vm_object. 1679 */ 1680 for (lobj = tobj = obj; tobj != NULL; tobj = tobj->backing_object) { 1681 if (tobj != obj) 1682 VM_OBJECT_RLOCK(tobj); 1683 if (lobj != obj) 1684 VM_OBJECT_RUNLOCK(lobj); 1685 lobj = tobj; 1686 } 1687 1688 /* 1689 * At this point lobj is the base vm_object and it is locked. 1690 */ 1691 if (lobj == NULL) { 1692 PMCDBG3(LOG,OPS,2, "hwpmc: lobj unexpectedly NULL! pid=%d " 1693 "vm_map=%p vm_obj=%p\n", p->p_pid, map, obj); 1694 VM_OBJECT_RUNLOCK(obj); 1695 continue; 1696 } 1697 1698 vp = vm_object_vnode(lobj); 1699 if (vp == NULL) { 1700 if (lobj != obj) 1701 VM_OBJECT_RUNLOCK(lobj); 1702 VM_OBJECT_RUNLOCK(obj); 1703 continue; 1704 } 1705 1706 /* 1707 * Skip contiguous regions that point to the same 1708 * vnode, so we don't emit redundant MAP-IN 1709 * directives. 1710 */ 1711 if (entry->start == last_end && vp == last_vp) { 1712 last_end = entry->end; 1713 if (lobj != obj) 1714 VM_OBJECT_RUNLOCK(lobj); 1715 VM_OBJECT_RUNLOCK(obj); 1716 continue; 1717 } 1718 1719 /* 1720 * We don't want to keep the proc's vm_map or this 1721 * vm_object locked while we walk the pathname, since 1722 * vn_fullpath() can sleep. However, if we drop the 1723 * lock, it's possible for concurrent activity to 1724 * modify the vm_map list. To protect against this, 1725 * we save the vm_map timestamp before we release the 1726 * lock, and check it after we reacquire the lock 1727 * below. 1728 */ 1729 start_addr = entry->start; 1730 last_end = entry->end; 1731 last_timestamp = map->timestamp; 1732 vm_map_unlock_read(map); 1733 1734 vref(vp); 1735 if (lobj != obj) 1736 VM_OBJECT_RUNLOCK(lobj); 1737 1738 VM_OBJECT_RUNLOCK(obj); 1739 1740 freepath = NULL; 1741 pmc_getfilename(vp, &fullpath, &freepath); 1742 last_vp = vp; 1743 1744 vrele(vp); 1745 1746 vp = NULL; 1747 pmclog_process_map_in(po, p->p_pid, start_addr, fullpath); 1748 if (freepath) 1749 free(freepath, M_TEMP); 1750 1751 vm_map_lock_read(map); 1752 1753 /* 1754 * If our saved timestamp doesn't match, this means 1755 * that the vm_map was modified out from under us and 1756 * we can't trust our current "entry" pointer. Do a 1757 * new lookup for this entry. If there is no entry 1758 * for this address range, vm_map_lookup_entry() will 1759 * return the previous one, so we always want to go to 1760 * entry->next on the next loop iteration. 1761 * 1762 * There is an edge condition here that can occur if 1763 * there is no entry at or before this address. In 1764 * this situation, vm_map_lookup_entry returns 1765 * &map->header, which would cause our loop to abort 1766 * without processing the rest of the map. However, 1767 * in practice this will never happen for process 1768 * vm_map. This is because the executable's text 1769 * segment is the first mapping in the proc's address 1770 * space, and this mapping is never removed until the 1771 * process exits, so there will always be a non-header 1772 * entry at or before the requested address for 1773 * vm_map_lookup_entry to return. 1774 */ 1775 if (map->timestamp != last_timestamp) 1776 vm_map_lookup_entry(map, last_end - 1, &entry); 1777 } 1778 1779 vm_map_unlock_read(map); 1780 vmspace_free(vm); 1781 return; 1782} 1783 1784/* 1785 * Log mappings for all processes in the system. 1786 */ 1787 1788static void 1789pmc_log_all_process_mappings(struct pmc_owner *po) 1790{ 1791 struct proc *p, *top; 1792 1793 sx_assert(&pmc_sx, SX_XLOCKED); 1794 1795 if ((p = pfind(1)) == NULL) 1796 panic("[pmc,%d] Cannot find init", __LINE__); 1797 1798 PROC_UNLOCK(p); 1799 1800 sx_slock(&proctree_lock); 1801 1802 top = p; 1803 1804 for (;;) { 1805 pmc_log_process_mappings(po, p); 1806 if (!LIST_EMPTY(&p->p_children)) 1807 p = LIST_FIRST(&p->p_children); 1808 else for (;;) { 1809 if (p == top) 1810 goto done; 1811 if (LIST_NEXT(p, p_sibling)) { 1812 p = LIST_NEXT(p, p_sibling); 1813 break; 1814 } 1815 p = p->p_pptr; 1816 } 1817 } 1818 done: 1819 sx_sunlock(&proctree_lock); 1820} 1821 1822/* 1823 * The 'hook' invoked from the kernel proper 1824 */ 1825 1826 1827#ifdef HWPMC_DEBUG 1828const char *pmc_hooknames[] = { 1829 /* these strings correspond to PMC_FN_* in <sys/pmckern.h> */ 1830 "", 1831 "EXEC", 1832 "CSW-IN", 1833 "CSW-OUT", 1834 "SAMPLE", 1835 "UNUSED1", 1836 "UNUSED2", 1837 "MMAP", 1838 "MUNMAP", 1839 "CALLCHAIN-NMI", 1840 "CALLCHAIN-SOFT", 1841 "SOFTSAMPLING" 1842}; 1843#endif 1844 1845static int 1846pmc_hook_handler(struct thread *td, int function, void *arg) 1847{ 1848 1849 PMCDBG4(MOD,PMH,1, "hook td=%p func=%d \"%s\" arg=%p", td, function, 1850 pmc_hooknames[function], arg); 1851 1852 switch (function) 1853 { 1854 1855 /* 1856 * Process exec() 1857 */ 1858 1859 case PMC_FN_PROCESS_EXEC: 1860 { 1861 char *fullpath, *freepath; 1862 unsigned int ri; 1863 int is_using_hwpmcs; 1864 struct pmc *pm; 1865 struct proc *p; 1866 struct pmc_owner *po; 1867 struct pmc_process *pp; 1868 struct pmckern_procexec *pk; 1869 1870 sx_assert(&pmc_sx, SX_XLOCKED); 1871 1872 p = td->td_proc; 1873 pmc_getfilename(p->p_textvp, &fullpath, &freepath); 1874 1875 pk = (struct pmckern_procexec *) arg; 1876 1877 /* Inform owners of SS mode PMCs of the exec event. */ 1878 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1879 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1880 pmclog_process_procexec(po, PMC_ID_INVALID, 1881 p->p_pid, pk->pm_entryaddr, fullpath); 1882 1883 PROC_LOCK(p); 1884 is_using_hwpmcs = p->p_flag & P_HWPMC; 1885 PROC_UNLOCK(p); 1886 1887 if (!is_using_hwpmcs) { 1888 if (freepath) 1889 free(freepath, M_TEMP); 1890 break; 1891 } 1892 1893 /* 1894 * PMCs are not inherited across an exec(): remove any 1895 * PMCs that this process is the owner of. 1896 */ 1897 1898 if ((po = pmc_find_owner_descriptor(p)) != NULL) { 1899 pmc_remove_owner(po); 1900 pmc_destroy_owner_descriptor(po); 1901 } 1902 1903 /* 1904 * If the process being exec'ed is not the target of any 1905 * PMC, we are done. 1906 */ 1907 if ((pp = pmc_find_process_descriptor(p, 0)) == NULL) { 1908 if (freepath) 1909 free(freepath, M_TEMP); 1910 break; 1911 } 1912 1913 /* 1914 * Log the exec event to all monitoring owners. Skip 1915 * owners who have already recieved the event because 1916 * they had system sampling PMCs active. 1917 */ 1918 for (ri = 0; ri < md->pmd_npmc; ri++) 1919 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) { 1920 po = pm->pm_owner; 1921 if (po->po_sscount == 0 && 1922 po->po_flags & PMC_PO_OWNS_LOGFILE) 1923 pmclog_process_procexec(po, pm->pm_id, 1924 p->p_pid, pk->pm_entryaddr, 1925 fullpath); 1926 } 1927 1928 if (freepath) 1929 free(freepath, M_TEMP); 1930 1931 1932 PMCDBG4(PRC,EXC,1, "exec proc=%p (%d, %s) cred-changed=%d", 1933 p, p->p_pid, p->p_comm, pk->pm_credentialschanged); 1934 1935 if (pk->pm_credentialschanged == 0) /* no change */ 1936 break; 1937 1938 /* 1939 * If the newly exec()'ed process has a different credential 1940 * than before, allow it to be the target of a PMC only if 1941 * the PMC's owner has sufficient priviledge. 1942 */ 1943 1944 for (ri = 0; ri < md->pmd_npmc; ri++) 1945 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) 1946 if (pmc_can_attach(pm, td->td_proc) != 0) 1947 pmc_detach_one_process(td->td_proc, 1948 pm, PMC_FLAG_NONE); 1949 1950 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= (int) md->pmd_npmc, 1951 ("[pmc,%d] Illegal ref count %d on pp %p", __LINE__, 1952 pp->pp_refcnt, pp)); 1953 1954 /* 1955 * If this process is no longer the target of any 1956 * PMCs, we can remove the process entry and free 1957 * up space. 1958 */ 1959 1960 if (pp->pp_refcnt == 0) { 1961 pmc_remove_process_descriptor(pp); 1962 free(pp, M_PMC); 1963 break; 1964 } 1965 1966 } 1967 break; 1968 1969 case PMC_FN_CSW_IN: 1970 pmc_process_csw_in(td); 1971 break; 1972 1973 case PMC_FN_CSW_OUT: 1974 pmc_process_csw_out(td); 1975 break; 1976 1977 /* 1978 * Process accumulated PC samples. 1979 * 1980 * This function is expected to be called by hardclock() for 1981 * each CPU that has accumulated PC samples. 1982 * 1983 * This function is to be executed on the CPU whose samples 1984 * are being processed. 1985 */ 1986 case PMC_FN_DO_SAMPLES: 1987 1988 /* 1989 * Clear the cpu specific bit in the CPU mask before 1990 * do the rest of the processing. If the NMI handler 1991 * gets invoked after the "atomic_clear_int()" call 1992 * below but before "pmc_process_samples()" gets 1993 * around to processing the interrupt, then we will 1994 * come back here at the next hardclock() tick (and 1995 * may find nothing to do if "pmc_process_samples()" 1996 * had already processed the interrupt). We don't 1997 * lose the interrupt sample. 1998 */ 1999 CPU_CLR_ATOMIC(PCPU_GET(cpuid), &pmc_cpumask); 2000 pmc_process_samples(PCPU_GET(cpuid), PMC_HR); 2001 pmc_process_samples(PCPU_GET(cpuid), PMC_SR); 2002 break; 2003 2004 case PMC_FN_MMAP: 2005 sx_assert(&pmc_sx, SX_LOCKED); 2006 pmc_process_mmap(td, (struct pmckern_map_in *) arg); 2007 break; 2008 2009 case PMC_FN_MUNMAP: 2010 sx_assert(&pmc_sx, SX_LOCKED); 2011 pmc_process_munmap(td, (struct pmckern_map_out *) arg); 2012 break; 2013 2014 case PMC_FN_USER_CALLCHAIN: 2015 /* 2016 * Record a call chain. 2017 */ 2018 KASSERT(td == curthread, ("[pmc,%d] td != curthread", 2019 __LINE__)); 2020 2021 pmc_capture_user_callchain(PCPU_GET(cpuid), PMC_HR, 2022 (struct trapframe *) arg); 2023 td->td_pflags &= ~TDP_CALLCHAIN; 2024 break; 2025 2026 case PMC_FN_USER_CALLCHAIN_SOFT: 2027 /* 2028 * Record a call chain. 2029 */ 2030 KASSERT(td == curthread, ("[pmc,%d] td != curthread", 2031 __LINE__)); 2032 pmc_capture_user_callchain(PCPU_GET(cpuid), PMC_SR, 2033 (struct trapframe *) arg); 2034 td->td_pflags &= ~TDP_CALLCHAIN; 2035 break; 2036 2037 case PMC_FN_SOFT_SAMPLING: 2038 /* 2039 * Call soft PMC sampling intr. 2040 */ 2041 pmc_soft_intr((struct pmckern_soft *) arg); 2042 break; 2043 2044 default: 2045#ifdef HWPMC_DEBUG 2046 KASSERT(0, ("[pmc,%d] unknown hook %d\n", __LINE__, function)); 2047#endif 2048 break; 2049 2050 } 2051 2052 return 0; 2053} 2054 2055/* 2056 * allocate a 'struct pmc_owner' descriptor in the owner hash table. 2057 */ 2058 2059static struct pmc_owner * 2060pmc_allocate_owner_descriptor(struct proc *p) 2061{ 2062 uint32_t hindex; 2063 struct pmc_owner *po; 2064 struct pmc_ownerhash *poh; 2065 2066 hindex = PMC_HASH_PTR(p, pmc_ownerhashmask); 2067 poh = &pmc_ownerhash[hindex]; 2068 2069 /* allocate space for N pointers and one descriptor struct */ 2070 po = malloc(sizeof(struct pmc_owner), M_PMC, M_WAITOK|M_ZERO); 2071 po->po_owner = p; 2072 LIST_INSERT_HEAD(poh, po, po_next); /* insert into hash table */ 2073 2074 TAILQ_INIT(&po->po_logbuffers); 2075 mtx_init(&po->po_mtx, "pmc-owner-mtx", "pmc-per-proc", MTX_SPIN); 2076 2077 PMCDBG4(OWN,ALL,1, "allocate-owner proc=%p (%d, %s) pmc-owner=%p", 2078 p, p->p_pid, p->p_comm, po); 2079 2080 return po; 2081} 2082 2083static void 2084pmc_destroy_owner_descriptor(struct pmc_owner *po) 2085{ 2086 2087 PMCDBG4(OWN,REL,1, "destroy-owner po=%p proc=%p (%d, %s)", 2088 po, po->po_owner, po->po_owner->p_pid, po->po_owner->p_comm); 2089 2090 mtx_destroy(&po->po_mtx); 2091 free(po, M_PMC); 2092} 2093 2094/* 2095 * find the descriptor corresponding to process 'p', adding or removing it 2096 * as specified by 'mode'. 2097 */ 2098 2099static struct pmc_process * 2100pmc_find_process_descriptor(struct proc *p, uint32_t mode) 2101{ 2102 uint32_t hindex; 2103 struct pmc_process *pp, *ppnew; 2104 struct pmc_processhash *pph; 2105 2106 hindex = PMC_HASH_PTR(p, pmc_processhashmask); 2107 pph = &pmc_processhash[hindex]; 2108 2109 ppnew = NULL; 2110 2111 /* 2112 * Pre-allocate memory in the FIND_ALLOCATE case since we 2113 * cannot call malloc(9) once we hold a spin lock. 2114 */ 2115 if (mode & PMC_FLAG_ALLOCATE) 2116 ppnew = malloc(sizeof(struct pmc_process) + md->pmd_npmc * 2117 sizeof(struct pmc_targetstate), M_PMC, M_WAITOK|M_ZERO); 2118 2119 mtx_lock_spin(&pmc_processhash_mtx); 2120 LIST_FOREACH(pp, pph, pp_next) 2121 if (pp->pp_proc == p) 2122 break; 2123 2124 if ((mode & PMC_FLAG_REMOVE) && pp != NULL) 2125 LIST_REMOVE(pp, pp_next); 2126 2127 if ((mode & PMC_FLAG_ALLOCATE) && pp == NULL && 2128 ppnew != NULL) { 2129 ppnew->pp_proc = p; 2130 LIST_INSERT_HEAD(pph, ppnew, pp_next); 2131 pp = ppnew; 2132 ppnew = NULL; 2133 } 2134 mtx_unlock_spin(&pmc_processhash_mtx); 2135 2136 if (pp != NULL && ppnew != NULL) 2137 free(ppnew, M_PMC); 2138 2139 return pp; 2140} 2141 2142/* 2143 * remove a process descriptor from the process hash table. 2144 */ 2145 2146static void 2147pmc_remove_process_descriptor(struct pmc_process *pp) 2148{ 2149 KASSERT(pp->pp_refcnt == 0, 2150 ("[pmc,%d] Removing process descriptor %p with count %d", 2151 __LINE__, pp, pp->pp_refcnt)); 2152 2153 mtx_lock_spin(&pmc_processhash_mtx); 2154 LIST_REMOVE(pp, pp_next); 2155 mtx_unlock_spin(&pmc_processhash_mtx); 2156} 2157 2158 2159/* 2160 * find an owner descriptor corresponding to proc 'p' 2161 */ 2162 2163static struct pmc_owner * 2164pmc_find_owner_descriptor(struct proc *p) 2165{ 2166 uint32_t hindex; 2167 struct pmc_owner *po; 2168 struct pmc_ownerhash *poh; 2169 2170 hindex = PMC_HASH_PTR(p, pmc_ownerhashmask); 2171 poh = &pmc_ownerhash[hindex]; 2172 2173 po = NULL; 2174 LIST_FOREACH(po, poh, po_next) 2175 if (po->po_owner == p) 2176 break; 2177 2178 PMCDBG5(OWN,FND,1, "find-owner proc=%p (%d, %s) hindex=0x%x -> " 2179 "pmc-owner=%p", p, p->p_pid, p->p_comm, hindex, po); 2180 2181 return po; 2182} 2183 2184/* 2185 * pmc_allocate_pmc_descriptor 2186 * 2187 * Allocate a pmc descriptor and initialize its 2188 * fields. 2189 */ 2190 2191static struct pmc * 2192pmc_allocate_pmc_descriptor(void) 2193{ 2194 struct pmc *pmc; 2195 2196 pmc = malloc(sizeof(struct pmc), M_PMC, M_WAITOK|M_ZERO); 2197 2198 PMCDBG1(PMC,ALL,1, "allocate-pmc -> pmc=%p", pmc); 2199 2200 return pmc; 2201} 2202 2203/* 2204 * Destroy a pmc descriptor. 2205 */ 2206 2207static void 2208pmc_destroy_pmc_descriptor(struct pmc *pm) 2209{ 2210 2211 KASSERT(pm->pm_state == PMC_STATE_DELETED || 2212 pm->pm_state == PMC_STATE_FREE, 2213 ("[pmc,%d] destroying non-deleted PMC", __LINE__)); 2214 KASSERT(LIST_EMPTY(&pm->pm_targets), 2215 ("[pmc,%d] destroying pmc with targets", __LINE__)); 2216 KASSERT(pm->pm_owner == NULL, 2217 ("[pmc,%d] destroying pmc attached to an owner", __LINE__)); 2218 KASSERT(pm->pm_runcount == 0, 2219 ("[pmc,%d] pmc has non-zero run count %d", __LINE__, 2220 pm->pm_runcount)); 2221 2222 free(pm, M_PMC); 2223} 2224 2225static void 2226pmc_wait_for_pmc_idle(struct pmc *pm) 2227{ 2228#ifdef HWPMC_DEBUG 2229 volatile int maxloop; 2230 2231 maxloop = 100 * pmc_cpu_max(); 2232#endif 2233 /* 2234 * Loop (with a forced context switch) till the PMC's runcount 2235 * comes down to zero. 2236 */ 2237 while (atomic_load_acq_32(&pm->pm_runcount) > 0) { 2238#ifdef HWPMC_DEBUG 2239 maxloop--; 2240 KASSERT(maxloop > 0, 2241 ("[pmc,%d] (ri%d, rc%d) waiting too long for " 2242 "pmc to be free", __LINE__, 2243 PMC_TO_ROWINDEX(pm), pm->pm_runcount)); 2244#endif 2245 pmc_force_context_switch(); 2246 } 2247} 2248 2249/* 2250 * This function does the following things: 2251 * 2252 * - detaches the PMC from hardware 2253 * - unlinks all target threads that were attached to it 2254 * - removes the PMC from its owner's list 2255 * - destroys the PMC private mutex 2256 * 2257 * Once this function completes, the given pmc pointer can be freed by 2258 * calling pmc_destroy_pmc_descriptor(). 2259 */ 2260 2261static void 2262pmc_release_pmc_descriptor(struct pmc *pm) 2263{ 2264 enum pmc_mode mode; 2265 struct pmc_hw *phw; 2266 u_int adjri, ri, cpu; 2267 struct pmc_owner *po; 2268 struct pmc_binding pb; 2269 struct pmc_process *pp; 2270 struct pmc_classdep *pcd; 2271 struct pmc_target *ptgt, *tmp; 2272 2273 sx_assert(&pmc_sx, SX_XLOCKED); 2274 2275 KASSERT(pm, ("[pmc,%d] null pmc", __LINE__)); 2276 2277 ri = PMC_TO_ROWINDEX(pm); 2278 pcd = pmc_ri_to_classdep(md, ri, &adjri); 2279 mode = PMC_TO_MODE(pm); 2280 2281 PMCDBG3(PMC,REL,1, "release-pmc pmc=%p ri=%d mode=%d", pm, ri, 2282 mode); 2283 2284 /* 2285 * First, we take the PMC off hardware. 2286 */ 2287 cpu = 0; 2288 if (PMC_IS_SYSTEM_MODE(mode)) { 2289 2290 /* 2291 * A system mode PMC runs on a specific CPU. Switch 2292 * to this CPU and turn hardware off. 2293 */ 2294 pmc_save_cpu_binding(&pb); 2295 2296 cpu = PMC_TO_CPU(pm); 2297 2298 pmc_select_cpu(cpu); 2299 2300 /* switch off non-stalled CPUs */ 2301 CPU_CLR_ATOMIC(cpu, &pm->pm_cpustate); 2302 if (pm->pm_state == PMC_STATE_RUNNING && 2303 !CPU_ISSET(cpu, &pm->pm_stalled)) { 2304 2305 phw = pmc_pcpu[cpu]->pc_hwpmcs[ri]; 2306 2307 KASSERT(phw->phw_pmc == pm, 2308 ("[pmc, %d] pmc ptr ri(%d) hw(%p) pm(%p)", 2309 __LINE__, ri, phw->phw_pmc, pm)); 2310 PMCDBG2(PMC,REL,2, "stopping cpu=%d ri=%d", cpu, ri); 2311 2312 critical_enter(); 2313 pcd->pcd_stop_pmc(cpu, adjri); 2314 critical_exit(); 2315 } 2316 2317 PMCDBG2(PMC,REL,2, "decfg cpu=%d ri=%d", cpu, ri); 2318 2319 critical_enter(); 2320 pcd->pcd_config_pmc(cpu, adjri, NULL); 2321 critical_exit(); 2322 2323 /* adjust the global and process count of SS mode PMCs */ 2324 if (mode == PMC_MODE_SS && pm->pm_state == PMC_STATE_RUNNING) { 2325 po = pm->pm_owner; 2326 po->po_sscount--; 2327 if (po->po_sscount == 0) { 2328 atomic_subtract_rel_int(&pmc_ss_count, 1); 2329 LIST_REMOVE(po, po_ssnext); 2330 } 2331 } 2332 2333 pm->pm_state = PMC_STATE_DELETED; 2334 2335 pmc_restore_cpu_binding(&pb); 2336 2337 /* 2338 * We could have references to this PMC structure in 2339 * the per-cpu sample queues. Wait for the queue to 2340 * drain. 2341 */ 2342 pmc_wait_for_pmc_idle(pm); 2343 2344 } else if (PMC_IS_VIRTUAL_MODE(mode)) { 2345 2346 /* 2347 * A virtual PMC could be running on multiple CPUs at 2348 * a given instant. 2349 * 2350 * By marking its state as DELETED, we ensure that 2351 * this PMC is never further scheduled on hardware. 2352 * 2353 * Then we wait till all CPUs are done with this PMC. 2354 */ 2355 pm->pm_state = PMC_STATE_DELETED; 2356 2357 2358 /* Wait for the PMCs runcount to come to zero. */ 2359 pmc_wait_for_pmc_idle(pm); 2360 2361 /* 2362 * At this point the PMC is off all CPUs and cannot be 2363 * freshly scheduled onto a CPU. It is now safe to 2364 * unlink all targets from this PMC. If a 2365 * process-record's refcount falls to zero, we remove 2366 * it from the hash table. The module-wide SX lock 2367 * protects us from races. 2368 */ 2369 LIST_FOREACH_SAFE(ptgt, &pm->pm_targets, pt_next, tmp) { 2370 pp = ptgt->pt_process; 2371 pmc_unlink_target_process(pm, pp); /* frees 'ptgt' */ 2372 2373 PMCDBG1(PMC,REL,3, "pp->refcnt=%d", pp->pp_refcnt); 2374 2375 /* 2376 * If the target process record shows that no 2377 * PMCs are attached to it, reclaim its space. 2378 */ 2379 2380 if (pp->pp_refcnt == 0) { 2381 pmc_remove_process_descriptor(pp); 2382 free(pp, M_PMC); 2383 } 2384 } 2385 2386 cpu = curthread->td_oncpu; /* setup cpu for pmd_release() */ 2387 2388 } 2389 2390 /* 2391 * Release any MD resources 2392 */ 2393 (void) pcd->pcd_release_pmc(cpu, adjri, pm); 2394 2395 /* 2396 * Update row disposition 2397 */ 2398 2399 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) 2400 PMC_UNMARK_ROW_STANDALONE(ri); 2401 else 2402 PMC_UNMARK_ROW_THREAD(ri); 2403 2404 /* unlink from the owner's list */ 2405 if (pm->pm_owner) { 2406 LIST_REMOVE(pm, pm_next); 2407 pm->pm_owner = NULL; 2408 } 2409} 2410 2411/* 2412 * Register an owner and a pmc. 2413 */ 2414 2415static int 2416pmc_register_owner(struct proc *p, struct pmc *pmc) 2417{ 2418 struct pmc_owner *po; 2419 2420 sx_assert(&pmc_sx, SX_XLOCKED); 2421 2422 if ((po = pmc_find_owner_descriptor(p)) == NULL) 2423 if ((po = pmc_allocate_owner_descriptor(p)) == NULL) 2424 return ENOMEM; 2425 2426 KASSERT(pmc->pm_owner == NULL, 2427 ("[pmc,%d] attempting to own an initialized PMC", __LINE__)); 2428 pmc->pm_owner = po; 2429 2430 LIST_INSERT_HEAD(&po->po_pmcs, pmc, pm_next); 2431 2432 PROC_LOCK(p); 2433 p->p_flag |= P_HWPMC; 2434 PROC_UNLOCK(p); 2435 2436 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 2437 pmclog_process_pmcallocate(pmc); 2438 2439 PMCDBG2(PMC,REG,1, "register-owner pmc-owner=%p pmc=%p", 2440 po, pmc); 2441 2442 return 0; 2443} 2444 2445/* 2446 * Return the current row disposition: 2447 * == 0 => FREE 2448 * > 0 => PROCESS MODE 2449 * < 0 => SYSTEM MODE 2450 */ 2451 2452int 2453pmc_getrowdisp(int ri) 2454{ 2455 return pmc_pmcdisp[ri]; 2456} 2457 2458/* 2459 * Check if a PMC at row index 'ri' can be allocated to the current 2460 * process. 2461 * 2462 * Allocation can fail if: 2463 * - the current process is already being profiled by a PMC at index 'ri', 2464 * attached to it via OP_PMCATTACH. 2465 * - the current process has already allocated a PMC at index 'ri' 2466 * via OP_ALLOCATE. 2467 */ 2468 2469static int 2470pmc_can_allocate_rowindex(struct proc *p, unsigned int ri, int cpu) 2471{ 2472 enum pmc_mode mode; 2473 struct pmc *pm; 2474 struct pmc_owner *po; 2475 struct pmc_process *pp; 2476 2477 PMCDBG5(PMC,ALR,1, "can-allocate-rowindex proc=%p (%d, %s) ri=%d " 2478 "cpu=%d", p, p->p_pid, p->p_comm, ri, cpu); 2479 2480 /* 2481 * We shouldn't have already allocated a process-mode PMC at 2482 * row index 'ri'. 2483 * 2484 * We shouldn't have allocated a system-wide PMC on the same 2485 * CPU and same RI. 2486 */ 2487 if ((po = pmc_find_owner_descriptor(p)) != NULL) 2488 LIST_FOREACH(pm, &po->po_pmcs, pm_next) { 2489 if (PMC_TO_ROWINDEX(pm) == ri) { 2490 mode = PMC_TO_MODE(pm); 2491 if (PMC_IS_VIRTUAL_MODE(mode)) 2492 return EEXIST; 2493 if (PMC_IS_SYSTEM_MODE(mode) && 2494 (int) PMC_TO_CPU(pm) == cpu) 2495 return EEXIST; 2496 } 2497 } 2498 2499 /* 2500 * We also shouldn't be the target of any PMC at this index 2501 * since otherwise a PMC_ATTACH to ourselves will fail. 2502 */ 2503 if ((pp = pmc_find_process_descriptor(p, 0)) != NULL) 2504 if (pp->pp_pmcs[ri].pp_pmc) 2505 return EEXIST; 2506 2507 PMCDBG4(PMC,ALR,2, "can-allocate-rowindex proc=%p (%d, %s) ri=%d ok", 2508 p, p->p_pid, p->p_comm, ri); 2509 2510 return 0; 2511} 2512 2513/* 2514 * Check if a given PMC at row index 'ri' can be currently used in 2515 * mode 'mode'. 2516 */ 2517 2518static int 2519pmc_can_allocate_row(int ri, enum pmc_mode mode) 2520{ 2521 enum pmc_disp disp; 2522 2523 sx_assert(&pmc_sx, SX_XLOCKED); 2524 2525 PMCDBG2(PMC,ALR,1, "can-allocate-row ri=%d mode=%d", ri, mode); 2526 2527 if (PMC_IS_SYSTEM_MODE(mode)) 2528 disp = PMC_DISP_STANDALONE; 2529 else 2530 disp = PMC_DISP_THREAD; 2531 2532 /* 2533 * check disposition for PMC row 'ri': 2534 * 2535 * Expected disposition Row-disposition Result 2536 * 2537 * STANDALONE STANDALONE or FREE proceed 2538 * STANDALONE THREAD fail 2539 * THREAD THREAD or FREE proceed 2540 * THREAD STANDALONE fail 2541 */ 2542 2543 if (!PMC_ROW_DISP_IS_FREE(ri) && 2544 !(disp == PMC_DISP_THREAD && PMC_ROW_DISP_IS_THREAD(ri)) && 2545 !(disp == PMC_DISP_STANDALONE && PMC_ROW_DISP_IS_STANDALONE(ri))) 2546 return EBUSY; 2547 2548 /* 2549 * All OK 2550 */ 2551 2552 PMCDBG2(PMC,ALR,2, "can-allocate-row ri=%d mode=%d ok", ri, mode); 2553 2554 return 0; 2555 2556} 2557 2558/* 2559 * Find a PMC descriptor with user handle 'pmcid' for thread 'td'. 2560 */ 2561 2562static struct pmc * 2563pmc_find_pmc_descriptor_in_process(struct pmc_owner *po, pmc_id_t pmcid) 2564{ 2565 struct pmc *pm; 2566 2567 KASSERT(PMC_ID_TO_ROWINDEX(pmcid) < md->pmd_npmc, 2568 ("[pmc,%d] Illegal pmc index %d (max %d)", __LINE__, 2569 PMC_ID_TO_ROWINDEX(pmcid), md->pmd_npmc)); 2570 2571 LIST_FOREACH(pm, &po->po_pmcs, pm_next) 2572 if (pm->pm_id == pmcid) 2573 return pm; 2574 2575 return NULL; 2576} 2577 2578static int 2579pmc_find_pmc(pmc_id_t pmcid, struct pmc **pmc) 2580{ 2581 2582 struct pmc *pm; 2583 struct pmc_owner *po; 2584 2585 PMCDBG1(PMC,FND,1, "find-pmc id=%d", pmcid); 2586 2587 if ((po = pmc_find_owner_descriptor(curthread->td_proc)) == NULL) 2588 return ESRCH; 2589 2590 if ((pm = pmc_find_pmc_descriptor_in_process(po, pmcid)) == NULL) 2591 return EINVAL; 2592 2593 PMCDBG2(PMC,FND,2, "find-pmc id=%d -> pmc=%p", pmcid, pm); 2594 2595 *pmc = pm; 2596 return 0; 2597} 2598 2599/* 2600 * Start a PMC. 2601 */ 2602 2603static int 2604pmc_start(struct pmc *pm) 2605{ 2606 enum pmc_mode mode; 2607 struct pmc_owner *po; 2608 struct pmc_binding pb; 2609 struct pmc_classdep *pcd; 2610 int adjri, error, cpu, ri; 2611 2612 KASSERT(pm != NULL, 2613 ("[pmc,%d] null pm", __LINE__)); 2614 2615 mode = PMC_TO_MODE(pm); 2616 ri = PMC_TO_ROWINDEX(pm); 2617 pcd = pmc_ri_to_classdep(md, ri, &adjri); 2618 2619 error = 0; 2620 2621 PMCDBG3(PMC,OPS,1, "start pmc=%p mode=%d ri=%d", pm, mode, ri); 2622 2623 po = pm->pm_owner; 2624 2625 /* 2626 * Disallow PMCSTART if a logfile is required but has not been 2627 * configured yet. 2628 */ 2629 if ((pm->pm_flags & PMC_F_NEEDS_LOGFILE) && 2630 (po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) 2631 return (EDOOFUS); /* programming error */ 2632 2633 /* 2634 * If this is a sampling mode PMC, log mapping information for 2635 * the kernel modules that are currently loaded. 2636 */ 2637 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 2638 pmc_log_kernel_mappings(pm); 2639 2640 if (PMC_IS_VIRTUAL_MODE(mode)) { 2641 2642 /* 2643 * If a PMCATTACH has never been done on this PMC, 2644 * attach it to its owner process. 2645 */ 2646 2647 if (LIST_EMPTY(&pm->pm_targets)) 2648 error = (pm->pm_flags & PMC_F_ATTACH_DONE) ? ESRCH : 2649 pmc_attach_process(po->po_owner, pm); 2650 2651 /* 2652 * If the PMC is attached to its owner, then force a context 2653 * switch to ensure that the MD state gets set correctly. 2654 */ 2655 2656 if (error == 0) { 2657 pm->pm_state = PMC_STATE_RUNNING; 2658 if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) 2659 pmc_force_context_switch(); 2660 } 2661 2662 return (error); 2663 } 2664 2665 2666 /* 2667 * A system-wide PMC. 2668 * 2669 * Add the owner to the global list if this is a system-wide 2670 * sampling PMC. 2671 */ 2672 2673 if (mode == PMC_MODE_SS) { 2674 if (po->po_sscount == 0) { 2675 LIST_INSERT_HEAD(&pmc_ss_owners, po, po_ssnext); 2676 atomic_add_rel_int(&pmc_ss_count, 1); 2677 PMCDBG1(PMC,OPS,1, "po=%p in global list", po); 2678 } 2679 po->po_sscount++; 2680 2681 /* 2682 * Log mapping information for all existing processes in the 2683 * system. Subsequent mappings are logged as they happen; 2684 * see pmc_process_mmap(). 2685 */ 2686 if (po->po_logprocmaps == 0) { 2687 pmc_log_all_process_mappings(po); 2688 po->po_logprocmaps = 1; 2689 } 2690 } 2691 2692 /* 2693 * Move to the CPU associated with this 2694 * PMC, and start the hardware. 2695 */ 2696 2697 pmc_save_cpu_binding(&pb); 2698 2699 cpu = PMC_TO_CPU(pm); 2700 2701 if (!pmc_cpu_is_active(cpu)) 2702 return (ENXIO); 2703 2704 pmc_select_cpu(cpu); 2705 2706 /* 2707 * global PMCs are configured at allocation time 2708 * so write out the initial value and start the PMC. 2709 */ 2710 2711 pm->pm_state = PMC_STATE_RUNNING; 2712 2713 critical_enter(); 2714 if ((error = pcd->pcd_write_pmc(cpu, adjri, 2715 PMC_IS_SAMPLING_MODE(mode) ? 2716 pm->pm_sc.pm_reloadcount : 2717 pm->pm_sc.pm_initial)) == 0) { 2718 /* If a sampling mode PMC, reset stalled state. */ 2719 if (PMC_IS_SAMPLING_MODE(mode)) 2720 CPU_CLR_ATOMIC(cpu, &pm->pm_stalled); 2721 2722 /* Indicate that we desire this to run. Start it. */ 2723 CPU_SET_ATOMIC(cpu, &pm->pm_cpustate); 2724 error = pcd->pcd_start_pmc(cpu, adjri); 2725 } 2726 critical_exit(); 2727 2728 pmc_restore_cpu_binding(&pb); 2729 2730 return (error); 2731} 2732 2733/* 2734 * Stop a PMC. 2735 */ 2736 2737static int 2738pmc_stop(struct pmc *pm) 2739{ 2740 struct pmc_owner *po; 2741 struct pmc_binding pb; 2742 struct pmc_classdep *pcd; 2743 int adjri, cpu, error, ri; 2744 2745 KASSERT(pm != NULL, ("[pmc,%d] null pmc", __LINE__)); 2746 2747 PMCDBG3(PMC,OPS,1, "stop pmc=%p mode=%d ri=%d", pm, 2748 PMC_TO_MODE(pm), PMC_TO_ROWINDEX(pm)); 2749 2750 pm->pm_state = PMC_STATE_STOPPED; 2751 2752 /* 2753 * If the PMC is a virtual mode one, changing the state to 2754 * non-RUNNING is enough to ensure that the PMC never gets 2755 * scheduled. 2756 * 2757 * If this PMC is current running on a CPU, then it will 2758 * handled correctly at the time its target process is context 2759 * switched out. 2760 */ 2761 2762 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) 2763 return 0; 2764 2765 /* 2766 * A system-mode PMC. Move to the CPU associated with 2767 * this PMC, and stop the hardware. We update the 2768 * 'initial count' so that a subsequent PMCSTART will 2769 * resume counting from the current hardware count. 2770 */ 2771 2772 pmc_save_cpu_binding(&pb); 2773 2774 cpu = PMC_TO_CPU(pm); 2775 2776 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 2777 ("[pmc,%d] illegal cpu=%d", __LINE__, cpu)); 2778 2779 if (!pmc_cpu_is_active(cpu)) 2780 return ENXIO; 2781 2782 pmc_select_cpu(cpu); 2783 2784 ri = PMC_TO_ROWINDEX(pm); 2785 pcd = pmc_ri_to_classdep(md, ri, &adjri); 2786 2787 CPU_CLR_ATOMIC(cpu, &pm->pm_cpustate); 2788 critical_enter(); 2789 if ((error = pcd->pcd_stop_pmc(cpu, adjri)) == 0) 2790 error = pcd->pcd_read_pmc(cpu, adjri, &pm->pm_sc.pm_initial); 2791 critical_exit(); 2792 2793 pmc_restore_cpu_binding(&pb); 2794 2795 po = pm->pm_owner; 2796 2797 /* remove this owner from the global list of SS PMC owners */ 2798 if (PMC_TO_MODE(pm) == PMC_MODE_SS) { 2799 po->po_sscount--; 2800 if (po->po_sscount == 0) { 2801 atomic_subtract_rel_int(&pmc_ss_count, 1); 2802 LIST_REMOVE(po, po_ssnext); 2803 PMCDBG1(PMC,OPS,2,"po=%p removed from global list", po); 2804 } 2805 } 2806 2807 return (error); 2808} 2809 2810 2811#ifdef HWPMC_DEBUG 2812static const char *pmc_op_to_name[] = { 2813#undef __PMC_OP 2814#define __PMC_OP(N, D) #N , 2815 __PMC_OPS() 2816 NULL 2817}; 2818#endif 2819 2820/* 2821 * The syscall interface 2822 */ 2823 2824#define PMC_GET_SX_XLOCK(...) do { \ 2825 sx_xlock(&pmc_sx); \ 2826 if (pmc_hook == NULL) { \ 2827 sx_xunlock(&pmc_sx); \ 2828 return __VA_ARGS__; \ 2829 } \ 2830} while (0) 2831 2832#define PMC_DOWNGRADE_SX() do { \ 2833 sx_downgrade(&pmc_sx); \ 2834 is_sx_downgraded = 1; \ 2835} while (0) 2836 2837static int 2838pmc_syscall_handler(struct thread *td, void *syscall_args) 2839{ 2840 int error, is_sx_downgraded, is_sx_locked, op; 2841 struct pmc_syscall_args *c; 2842 void *arg; 2843 2844 PMC_GET_SX_XLOCK(ENOSYS); 2845 2846 DROP_GIANT(); 2847 2848 is_sx_downgraded = 0; 2849 is_sx_locked = 1; 2850 2851 c = (struct pmc_syscall_args *) syscall_args; 2852 2853 op = c->pmop_code; 2854 arg = c->pmop_data; 2855 2856 PMCDBG3(MOD,PMS,1, "syscall op=%d \"%s\" arg=%p", op, 2857 pmc_op_to_name[op], arg); 2858 2859 error = 0; 2860 atomic_add_int(&pmc_stats.pm_syscalls, 1); 2861 2862 switch(op) 2863 { 2864 2865 2866 /* 2867 * Configure a log file. 2868 * 2869 * XXX This OP will be reworked. 2870 */ 2871 2872 case PMC_OP_CONFIGURELOG: 2873 { 2874 struct proc *p; 2875 struct pmc *pm; 2876 struct pmc_owner *po; 2877 struct pmc_op_configurelog cl; 2878 2879 sx_assert(&pmc_sx, SX_XLOCKED); 2880 2881 if ((error = copyin(arg, &cl, sizeof(cl))) != 0) 2882 break; 2883 2884 /* mark this process as owning a log file */ 2885 p = td->td_proc; 2886 if ((po = pmc_find_owner_descriptor(p)) == NULL) 2887 if ((po = pmc_allocate_owner_descriptor(p)) == NULL) { 2888 error = ENOMEM; 2889 break; 2890 } 2891 2892 /* 2893 * If a valid fd was passed in, try to configure that, 2894 * otherwise if 'fd' was less than zero and there was 2895 * a log file configured, flush its buffers and 2896 * de-configure it. 2897 */ 2898 if (cl.pm_logfd >= 0) { 2899 sx_xunlock(&pmc_sx); 2900 is_sx_locked = 0; 2901 error = pmclog_configure_log(md, po, cl.pm_logfd); 2902 } else if (po->po_flags & PMC_PO_OWNS_LOGFILE) { 2903 pmclog_process_closelog(po); 2904 error = pmclog_close(po); 2905 if (error == 0) { 2906 LIST_FOREACH(pm, &po->po_pmcs, pm_next) 2907 if (pm->pm_flags & PMC_F_NEEDS_LOGFILE && 2908 pm->pm_state == PMC_STATE_RUNNING) 2909 pmc_stop(pm); 2910 error = pmclog_deconfigure_log(po); 2911 } 2912 } else 2913 error = EINVAL; 2914 2915 if (error) 2916 break; 2917 } 2918 break; 2919 2920 /* 2921 * Flush a log file. 2922 */ 2923 2924 case PMC_OP_FLUSHLOG: 2925 { 2926 struct pmc_owner *po; 2927 2928 sx_assert(&pmc_sx, SX_XLOCKED); 2929 2930 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 2931 error = EINVAL; 2932 break; 2933 } 2934 2935 error = pmclog_flush(po); 2936 } 2937 break; 2938 2939 /* 2940 * Close a log file. 2941 */ 2942 2943 case PMC_OP_CLOSELOG: 2944 { 2945 struct pmc_owner *po; 2946 2947 sx_assert(&pmc_sx, SX_XLOCKED); 2948 2949 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 2950 error = EINVAL; 2951 break; 2952 } 2953 2954 error = pmclog_close(po); 2955 } 2956 break; 2957 2958 /* 2959 * Retrieve hardware configuration. 2960 */ 2961 2962 case PMC_OP_GETCPUINFO: /* CPU information */ 2963 { 2964 struct pmc_op_getcpuinfo gci; 2965 struct pmc_classinfo *pci; 2966 struct pmc_classdep *pcd; 2967 int cl; 2968 2969 gci.pm_cputype = md->pmd_cputype; 2970 gci.pm_ncpu = pmc_cpu_max(); 2971 gci.pm_npmc = md->pmd_npmc; 2972 gci.pm_nclass = md->pmd_nclass; 2973 pci = gci.pm_classes; 2974 pcd = md->pmd_classdep; 2975 for (cl = 0; cl < md->pmd_nclass; cl++, pci++, pcd++) { 2976 pci->pm_caps = pcd->pcd_caps; 2977 pci->pm_class = pcd->pcd_class; 2978 pci->pm_width = pcd->pcd_width; 2979 pci->pm_num = pcd->pcd_num; 2980 } 2981 error = copyout(&gci, arg, sizeof(gci)); 2982 } 2983 break; 2984 2985 /* 2986 * Retrieve soft events list. 2987 */ 2988 case PMC_OP_GETDYNEVENTINFO: 2989 { 2990 enum pmc_class cl; 2991 enum pmc_event ev; 2992 struct pmc_op_getdyneventinfo *gei; 2993 struct pmc_dyn_event_descr dev; 2994 struct pmc_soft *ps; 2995 uint32_t nevent; 2996 2997 sx_assert(&pmc_sx, SX_LOCKED); 2998 2999 gei = (struct pmc_op_getdyneventinfo *) arg; 3000 3001 if ((error = copyin(&gei->pm_class, &cl, sizeof(cl))) != 0) 3002 break; 3003 3004 /* Only SOFT class is dynamic. */ 3005 if (cl != PMC_CLASS_SOFT) { 3006 error = EINVAL; 3007 break; 3008 } 3009 3010 nevent = 0; 3011 for (ev = PMC_EV_SOFT_FIRST; (int)ev <= PMC_EV_SOFT_LAST; ev++) { 3012 ps = pmc_soft_ev_acquire(ev); 3013 if (ps == NULL) 3014 continue; 3015 bcopy(&ps->ps_ev, &dev, sizeof(dev)); 3016 pmc_soft_ev_release(ps); 3017 3018 error = copyout(&dev, 3019 &gei->pm_events[nevent], 3020 sizeof(struct pmc_dyn_event_descr)); 3021 if (error != 0) 3022 break; 3023 nevent++; 3024 } 3025 if (error != 0) 3026 break; 3027 3028 error = copyout(&nevent, &gei->pm_nevent, 3029 sizeof(nevent)); 3030 } 3031 break; 3032 3033 /* 3034 * Get module statistics 3035 */ 3036 3037 case PMC_OP_GETDRIVERSTATS: 3038 { 3039 struct pmc_op_getdriverstats gms; 3040 3041 bcopy(&pmc_stats, &gms, sizeof(gms)); 3042 error = copyout(&gms, arg, sizeof(gms)); 3043 } 3044 break; 3045 3046 3047 /* 3048 * Retrieve module version number 3049 */ 3050 3051 case PMC_OP_GETMODULEVERSION: 3052 { 3053 uint32_t cv, modv; 3054 3055 /* retrieve the client's idea of the ABI version */ 3056 if ((error = copyin(arg, &cv, sizeof(uint32_t))) != 0) 3057 break; 3058 /* don't service clients newer than our driver */ 3059 modv = PMC_VERSION; 3060 if ((cv & 0xFFFF0000) > (modv & 0xFFFF0000)) { 3061 error = EPROGMISMATCH; 3062 break; 3063 } 3064 error = copyout(&modv, arg, sizeof(int)); 3065 } 3066 break; 3067 3068 3069 /* 3070 * Retrieve the state of all the PMCs on a given 3071 * CPU. 3072 */ 3073 3074 case PMC_OP_GETPMCINFO: 3075 { 3076 int ari; 3077 struct pmc *pm; 3078 size_t pmcinfo_size; 3079 uint32_t cpu, n, npmc; 3080 struct pmc_owner *po; 3081 struct pmc_binding pb; 3082 struct pmc_classdep *pcd; 3083 struct pmc_info *p, *pmcinfo; 3084 struct pmc_op_getpmcinfo *gpi; 3085 3086 PMC_DOWNGRADE_SX(); 3087 3088 gpi = (struct pmc_op_getpmcinfo *) arg; 3089 3090 if ((error = copyin(&gpi->pm_cpu, &cpu, sizeof(cpu))) != 0) 3091 break; 3092 3093 if (cpu >= pmc_cpu_max()) { 3094 error = EINVAL; 3095 break; 3096 } 3097 3098 if (!pmc_cpu_is_active(cpu)) { 3099 error = ENXIO; 3100 break; 3101 } 3102 3103 /* switch to CPU 'cpu' */ 3104 pmc_save_cpu_binding(&pb); 3105 pmc_select_cpu(cpu); 3106 3107 npmc = md->pmd_npmc; 3108 3109 pmcinfo_size = npmc * sizeof(struct pmc_info); 3110 pmcinfo = malloc(pmcinfo_size, M_PMC, M_WAITOK); 3111 3112 p = pmcinfo; 3113 3114 for (n = 0; n < md->pmd_npmc; n++, p++) { 3115 3116 pcd = pmc_ri_to_classdep(md, n, &ari); 3117 3118 KASSERT(pcd != NULL, 3119 ("[pmc,%d] null pcd ri=%d", __LINE__, n)); 3120 3121 if ((error = pcd->pcd_describe(cpu, ari, p, &pm)) != 0) 3122 break; 3123 3124 if (PMC_ROW_DISP_IS_STANDALONE(n)) 3125 p->pm_rowdisp = PMC_DISP_STANDALONE; 3126 else if (PMC_ROW_DISP_IS_THREAD(n)) 3127 p->pm_rowdisp = PMC_DISP_THREAD; 3128 else 3129 p->pm_rowdisp = PMC_DISP_FREE; 3130 3131 p->pm_ownerpid = -1; 3132 3133 if (pm == NULL) /* no PMC associated */ 3134 continue; 3135 3136 po = pm->pm_owner; 3137 3138 KASSERT(po->po_owner != NULL, 3139 ("[pmc,%d] pmc_owner had a null proc pointer", 3140 __LINE__)); 3141 3142 p->pm_ownerpid = po->po_owner->p_pid; 3143 p->pm_mode = PMC_TO_MODE(pm); 3144 p->pm_event = pm->pm_event; 3145 p->pm_flags = pm->pm_flags; 3146 3147 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 3148 p->pm_reloadcount = 3149 pm->pm_sc.pm_reloadcount; 3150 } 3151 3152 pmc_restore_cpu_binding(&pb); 3153 3154 /* now copy out the PMC info collected */ 3155 if (error == 0) 3156 error = copyout(pmcinfo, &gpi->pm_pmcs, pmcinfo_size); 3157 3158 free(pmcinfo, M_PMC); 3159 } 3160 break; 3161 3162 3163 /* 3164 * Set the administrative state of a PMC. I.e. whether 3165 * the PMC is to be used or not. 3166 */ 3167 3168 case PMC_OP_PMCADMIN: 3169 { 3170 int cpu, ri; 3171 enum pmc_state request; 3172 struct pmc_cpu *pc; 3173 struct pmc_hw *phw; 3174 struct pmc_op_pmcadmin pma; 3175 struct pmc_binding pb; 3176 3177 sx_assert(&pmc_sx, SX_XLOCKED); 3178 3179 KASSERT(td == curthread, 3180 ("[pmc,%d] td != curthread", __LINE__)); 3181 3182 error = priv_check(td, PRIV_PMC_MANAGE); 3183 if (error) 3184 break; 3185 3186 if ((error = copyin(arg, &pma, sizeof(pma))) != 0) 3187 break; 3188 3189 cpu = pma.pm_cpu; 3190 3191 if (cpu < 0 || cpu >= (int) pmc_cpu_max()) { 3192 error = EINVAL; 3193 break; 3194 } 3195 3196 if (!pmc_cpu_is_active(cpu)) { 3197 error = ENXIO; 3198 break; 3199 } 3200 3201 request = pma.pm_state; 3202 3203 if (request != PMC_STATE_DISABLED && 3204 request != PMC_STATE_FREE) { 3205 error = EINVAL; 3206 break; 3207 } 3208 3209 ri = pma.pm_pmc; /* pmc id == row index */ 3210 if (ri < 0 || ri >= (int) md->pmd_npmc) { 3211 error = EINVAL; 3212 break; 3213 } 3214 3215 /* 3216 * We can't disable a PMC with a row-index allocated 3217 * for process virtual PMCs. 3218 */ 3219 3220 if (PMC_ROW_DISP_IS_THREAD(ri) && 3221 request == PMC_STATE_DISABLED) { 3222 error = EBUSY; 3223 break; 3224 } 3225 3226 /* 3227 * otherwise, this PMC on this CPU is either free or 3228 * in system-wide mode. 3229 */ 3230 3231 pmc_save_cpu_binding(&pb); 3232 pmc_select_cpu(cpu); 3233 3234 pc = pmc_pcpu[cpu]; 3235 phw = pc->pc_hwpmcs[ri]; 3236 3237 /* 3238 * XXX do we need some kind of 'forced' disable? 3239 */ 3240 3241 if (phw->phw_pmc == NULL) { 3242 if (request == PMC_STATE_DISABLED && 3243 (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED)) { 3244 phw->phw_state &= ~PMC_PHW_FLAG_IS_ENABLED; 3245 PMC_MARK_ROW_STANDALONE(ri); 3246 } else if (request == PMC_STATE_FREE && 3247 (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0) { 3248 phw->phw_state |= PMC_PHW_FLAG_IS_ENABLED; 3249 PMC_UNMARK_ROW_STANDALONE(ri); 3250 } 3251 /* other cases are a no-op */ 3252 } else 3253 error = EBUSY; 3254 3255 pmc_restore_cpu_binding(&pb); 3256 } 3257 break; 3258 3259 3260 /* 3261 * Allocate a PMC. 3262 */ 3263 3264 case PMC_OP_PMCALLOCATE: 3265 { 3266 int adjri, n; 3267 u_int cpu; 3268 uint32_t caps; 3269 struct pmc *pmc; 3270 enum pmc_mode mode; 3271 struct pmc_hw *phw; 3272 struct pmc_binding pb; 3273 struct pmc_classdep *pcd; 3274 struct pmc_op_pmcallocate pa; 3275 3276 if ((error = copyin(arg, &pa, sizeof(pa))) != 0) 3277 break; 3278 3279 caps = pa.pm_caps; 3280 mode = pa.pm_mode; 3281 cpu = pa.pm_cpu; 3282 3283 if ((mode != PMC_MODE_SS && mode != PMC_MODE_SC && 3284 mode != PMC_MODE_TS && mode != PMC_MODE_TC) || 3285 (cpu != (u_int) PMC_CPU_ANY && cpu >= pmc_cpu_max())) { 3286 error = EINVAL; 3287 break; 3288 } 3289 3290 /* 3291 * Virtual PMCs should only ask for a default CPU. 3292 * System mode PMCs need to specify a non-default CPU. 3293 */ 3294 3295 if ((PMC_IS_VIRTUAL_MODE(mode) && cpu != (u_int) PMC_CPU_ANY) || 3296 (PMC_IS_SYSTEM_MODE(mode) && cpu == (u_int) PMC_CPU_ANY)) { 3297 error = EINVAL; 3298 break; 3299 } 3300 3301 /* 3302 * Check that an inactive CPU is not being asked for. 3303 */ 3304 3305 if (PMC_IS_SYSTEM_MODE(mode) && !pmc_cpu_is_active(cpu)) { 3306 error = ENXIO; 3307 break; 3308 } 3309 3310 /* 3311 * Refuse an allocation for a system-wide PMC if this 3312 * process has been jailed, or if this process lacks 3313 * super-user credentials and the sysctl tunable 3314 * 'security.bsd.unprivileged_syspmcs' is zero. 3315 */ 3316 3317 if (PMC_IS_SYSTEM_MODE(mode)) { 3318 if (jailed(curthread->td_ucred)) { 3319 error = EPERM; 3320 break; 3321 } 3322 if (!pmc_unprivileged_syspmcs) { 3323 error = priv_check(curthread, 3324 PRIV_PMC_SYSTEM); 3325 if (error) 3326 break; 3327 } 3328 } 3329 3330 /* 3331 * Look for valid values for 'pm_flags' 3332 */ 3333 3334 if ((pa.pm_flags & ~(PMC_F_DESCENDANTS | PMC_F_LOG_PROCCSW | 3335 PMC_F_LOG_PROCEXIT | PMC_F_CALLCHAIN)) != 0) { 3336 error = EINVAL; 3337 break; 3338 } 3339 3340 /* process logging options are not allowed for system PMCs */ 3341 if (PMC_IS_SYSTEM_MODE(mode) && (pa.pm_flags & 3342 (PMC_F_LOG_PROCCSW | PMC_F_LOG_PROCEXIT))) { 3343 error = EINVAL; 3344 break; 3345 } 3346 3347 /* 3348 * All sampling mode PMCs need to be able to interrupt the 3349 * CPU. 3350 */ 3351 if (PMC_IS_SAMPLING_MODE(mode)) 3352 caps |= PMC_CAP_INTERRUPT; 3353 3354 /* A valid class specifier should have been passed in. */ 3355 for (n = 0; n < md->pmd_nclass; n++) 3356 if (md->pmd_classdep[n].pcd_class == pa.pm_class) 3357 break; 3358 if (n == md->pmd_nclass) { 3359 error = EINVAL; 3360 break; 3361 } 3362 3363 /* The requested PMC capabilities should be feasible. */ 3364 if ((md->pmd_classdep[n].pcd_caps & caps) != caps) { 3365 error = EOPNOTSUPP; 3366 break; 3367 } 3368 3369 PMCDBG4(PMC,ALL,2, "event=%d caps=0x%x mode=%d cpu=%d", 3370 pa.pm_ev, caps, mode, cpu); 3371 3372 pmc = pmc_allocate_pmc_descriptor(); 3373 pmc->pm_id = PMC_ID_MAKE_ID(cpu,pa.pm_mode,pa.pm_class, 3374 PMC_ID_INVALID); 3375 pmc->pm_event = pa.pm_ev; 3376 pmc->pm_state = PMC_STATE_FREE; 3377 pmc->pm_caps = caps; 3378 pmc->pm_flags = pa.pm_flags; 3379 3380 /* switch thread to CPU 'cpu' */ 3381 pmc_save_cpu_binding(&pb); 3382 3383#define PMC_IS_SHAREABLE_PMC(cpu, n) \ 3384 (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_state & \ 3385 PMC_PHW_FLAG_IS_SHAREABLE) 3386#define PMC_IS_UNALLOCATED(cpu, n) \ 3387 (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_pmc == NULL) 3388 3389 if (PMC_IS_SYSTEM_MODE(mode)) { 3390 pmc_select_cpu(cpu); 3391 for (n = 0; n < (int) md->pmd_npmc; n++) { 3392 pcd = pmc_ri_to_classdep(md, n, &adjri); 3393 if (pmc_can_allocate_row(n, mode) == 0 && 3394 pmc_can_allocate_rowindex( 3395 curthread->td_proc, n, cpu) == 0 && 3396 (PMC_IS_UNALLOCATED(cpu, n) || 3397 PMC_IS_SHAREABLE_PMC(cpu, n)) && 3398 pcd->pcd_allocate_pmc(cpu, adjri, pmc, 3399 &pa) == 0) 3400 break; 3401 } 3402 } else { 3403 /* Process virtual mode */ 3404 for (n = 0; n < (int) md->pmd_npmc; n++) { 3405 pcd = pmc_ri_to_classdep(md, n, &adjri); 3406 if (pmc_can_allocate_row(n, mode) == 0 && 3407 pmc_can_allocate_rowindex( 3408 curthread->td_proc, n, 3409 PMC_CPU_ANY) == 0 && 3410 pcd->pcd_allocate_pmc(curthread->td_oncpu, 3411 adjri, pmc, &pa) == 0) 3412 break; 3413 } 3414 } 3415 3416#undef PMC_IS_UNALLOCATED 3417#undef PMC_IS_SHAREABLE_PMC 3418 3419 pmc_restore_cpu_binding(&pb); 3420 3421 if (n == (int) md->pmd_npmc) { 3422 pmc_destroy_pmc_descriptor(pmc); 3423 pmc = NULL; 3424 error = EINVAL; 3425 break; 3426 } 3427 3428 /* Fill in the correct value in the ID field */ 3429 pmc->pm_id = PMC_ID_MAKE_ID(cpu,mode,pa.pm_class,n); 3430 3431 PMCDBG5(PMC,ALL,2, "ev=%d class=%d mode=%d n=%d -> pmcid=%x", 3432 pmc->pm_event, pa.pm_class, mode, n, pmc->pm_id); 3433 3434 /* Process mode PMCs with logging enabled need log files */ 3435 if (pmc->pm_flags & (PMC_F_LOG_PROCEXIT | PMC_F_LOG_PROCCSW)) 3436 pmc->pm_flags |= PMC_F_NEEDS_LOGFILE; 3437 3438 /* All system mode sampling PMCs require a log file */ 3439 if (PMC_IS_SAMPLING_MODE(mode) && PMC_IS_SYSTEM_MODE(mode)) 3440 pmc->pm_flags |= PMC_F_NEEDS_LOGFILE; 3441 3442 /* 3443 * Configure global pmc's immediately 3444 */ 3445 3446 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pmc))) { 3447 3448 pmc_save_cpu_binding(&pb); 3449 pmc_select_cpu(cpu); 3450 3451 phw = pmc_pcpu[cpu]->pc_hwpmcs[n]; 3452 pcd = pmc_ri_to_classdep(md, n, &adjri); 3453 3454 if ((phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0 || 3455 (error = pcd->pcd_config_pmc(cpu, adjri, pmc)) != 0) { 3456 (void) pcd->pcd_release_pmc(cpu, adjri, pmc); 3457 pmc_destroy_pmc_descriptor(pmc); 3458 pmc = NULL; 3459 pmc_restore_cpu_binding(&pb); 3460 error = EPERM; 3461 break; 3462 } 3463 3464 pmc_restore_cpu_binding(&pb); 3465 } 3466 3467 pmc->pm_state = PMC_STATE_ALLOCATED; 3468 3469 /* 3470 * mark row disposition 3471 */ 3472 3473 if (PMC_IS_SYSTEM_MODE(mode)) 3474 PMC_MARK_ROW_STANDALONE(n); 3475 else 3476 PMC_MARK_ROW_THREAD(n); 3477 3478 /* 3479 * Register this PMC with the current thread as its owner. 3480 */ 3481 3482 if ((error = 3483 pmc_register_owner(curthread->td_proc, pmc)) != 0) { 3484 pmc_release_pmc_descriptor(pmc); 3485 pmc_destroy_pmc_descriptor(pmc); 3486 pmc = NULL; 3487 break; 3488 } 3489 3490 /* 3491 * Return the allocated index. 3492 */ 3493 3494 pa.pm_pmcid = pmc->pm_id; 3495 3496 error = copyout(&pa, arg, sizeof(pa)); 3497 } 3498 break; 3499 3500 3501 /* 3502 * Attach a PMC to a process. 3503 */ 3504 3505 case PMC_OP_PMCATTACH: 3506 { 3507 struct pmc *pm; 3508 struct proc *p; 3509 struct pmc_op_pmcattach a; 3510 3511 sx_assert(&pmc_sx, SX_XLOCKED); 3512 3513 if ((error = copyin(arg, &a, sizeof(a))) != 0) 3514 break; 3515 3516 if (a.pm_pid < 0) { 3517 error = EINVAL; 3518 break; 3519 } else if (a.pm_pid == 0) 3520 a.pm_pid = td->td_proc->p_pid; 3521 3522 if ((error = pmc_find_pmc(a.pm_pmc, &pm)) != 0) 3523 break; 3524 3525 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) { 3526 error = EINVAL; 3527 break; 3528 } 3529 3530 /* PMCs may be (re)attached only when allocated or stopped */ 3531 if (pm->pm_state == PMC_STATE_RUNNING) { 3532 error = EBUSY; 3533 break; 3534 } else if (pm->pm_state != PMC_STATE_ALLOCATED && 3535 pm->pm_state != PMC_STATE_STOPPED) { 3536 error = EINVAL; 3537 break; 3538 } 3539 3540 /* lookup pid */ 3541 if ((p = pfind(a.pm_pid)) == NULL) { 3542 error = ESRCH; 3543 break; 3544 } 3545 3546 /* 3547 * Ignore processes that are working on exiting. 3548 */ 3549 if (p->p_flag & P_WEXIT) { 3550 error = ESRCH; 3551 PROC_UNLOCK(p); /* pfind() returns a locked process */ 3552 break; 3553 } 3554 3555 /* 3556 * we are allowed to attach a PMC to a process if 3557 * we can debug it. 3558 */ 3559 error = p_candebug(curthread, p); 3560 3561 PROC_UNLOCK(p); 3562 3563 if (error == 0) 3564 error = pmc_attach_process(p, pm); 3565 } 3566 break; 3567 3568 3569 /* 3570 * Detach an attached PMC from a process. 3571 */ 3572 3573 case PMC_OP_PMCDETACH: 3574 { 3575 struct pmc *pm; 3576 struct proc *p; 3577 struct pmc_op_pmcattach a; 3578 3579 if ((error = copyin(arg, &a, sizeof(a))) != 0) 3580 break; 3581 3582 if (a.pm_pid < 0) { 3583 error = EINVAL; 3584 break; 3585 } else if (a.pm_pid == 0) 3586 a.pm_pid = td->td_proc->p_pid; 3587 3588 if ((error = pmc_find_pmc(a.pm_pmc, &pm)) != 0) 3589 break; 3590 3591 if ((p = pfind(a.pm_pid)) == NULL) { 3592 error = ESRCH; 3593 break; 3594 } 3595 3596 /* 3597 * Treat processes that are in the process of exiting 3598 * as if they were not present. 3599 */ 3600 3601 if (p->p_flag & P_WEXIT) 3602 error = ESRCH; 3603 3604 PROC_UNLOCK(p); /* pfind() returns a locked process */ 3605 3606 if (error == 0) 3607 error = pmc_detach_process(p, pm); 3608 } 3609 break; 3610 3611 3612 /* 3613 * Retrieve the MSR number associated with the counter 3614 * 'pmc_id'. This allows processes to directly use RDPMC 3615 * instructions to read their PMCs, without the overhead of a 3616 * system call. 3617 */ 3618 3619 case PMC_OP_PMCGETMSR: 3620 { 3621 int adjri, ri; 3622 struct pmc *pm; 3623 struct pmc_target *pt; 3624 struct pmc_op_getmsr gm; 3625 struct pmc_classdep *pcd; 3626 3627 PMC_DOWNGRADE_SX(); 3628 3629 if ((error = copyin(arg, &gm, sizeof(gm))) != 0) 3630 break; 3631 3632 if ((error = pmc_find_pmc(gm.pm_pmcid, &pm)) != 0) 3633 break; 3634 3635 /* 3636 * The allocated PMC has to be a process virtual PMC, 3637 * i.e., of type MODE_T[CS]. Global PMCs can only be 3638 * read using the PMCREAD operation since they may be 3639 * allocated on a different CPU than the one we could 3640 * be running on at the time of the RDPMC instruction. 3641 * 3642 * The GETMSR operation is not allowed for PMCs that 3643 * are inherited across processes. 3644 */ 3645 3646 if (!PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)) || 3647 (pm->pm_flags & PMC_F_DESCENDANTS)) { 3648 error = EINVAL; 3649 break; 3650 } 3651 3652 /* 3653 * It only makes sense to use a RDPMC (or its 3654 * equivalent instruction on non-x86 architectures) on 3655 * a process that has allocated and attached a PMC to 3656 * itself. Conversely the PMC is only allowed to have 3657 * one process attached to it -- its owner. 3658 */ 3659 3660 if ((pt = LIST_FIRST(&pm->pm_targets)) == NULL || 3661 LIST_NEXT(pt, pt_next) != NULL || 3662 pt->pt_process->pp_proc != pm->pm_owner->po_owner) { 3663 error = EINVAL; 3664 break; 3665 } 3666 3667 ri = PMC_TO_ROWINDEX(pm); 3668 pcd = pmc_ri_to_classdep(md, ri, &adjri); 3669 3670 /* PMC class has no 'GETMSR' support */ 3671 if (pcd->pcd_get_msr == NULL) { 3672 error = ENOSYS; 3673 break; 3674 } 3675 3676 if ((error = (*pcd->pcd_get_msr)(adjri, &gm.pm_msr)) < 0) 3677 break; 3678 3679 if ((error = copyout(&gm, arg, sizeof(gm))) < 0) 3680 break; 3681 3682 /* 3683 * Mark our process as using MSRs. Update machine 3684 * state using a forced context switch. 3685 */ 3686 3687 pt->pt_process->pp_flags |= PMC_PP_ENABLE_MSR_ACCESS; 3688 pmc_force_context_switch(); 3689 3690 } 3691 break; 3692 3693 /* 3694 * Release an allocated PMC 3695 */ 3696 3697 case PMC_OP_PMCRELEASE: 3698 { 3699 pmc_id_t pmcid; 3700 struct pmc *pm; 3701 struct pmc_owner *po; 3702 struct pmc_op_simple sp; 3703 3704 /* 3705 * Find PMC pointer for the named PMC. 3706 * 3707 * Use pmc_release_pmc_descriptor() to switch off the 3708 * PMC, remove all its target threads, and remove the 3709 * PMC from its owner's list. 3710 * 3711 * Remove the owner record if this is the last PMC 3712 * owned. 3713 * 3714 * Free up space. 3715 */ 3716 3717 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 3718 break; 3719 3720 pmcid = sp.pm_pmcid; 3721 3722 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 3723 break; 3724 3725 po = pm->pm_owner; 3726 pmc_release_pmc_descriptor(pm); 3727 pmc_maybe_remove_owner(po); 3728 pmc_destroy_pmc_descriptor(pm); 3729 } 3730 break; 3731 3732 3733 /* 3734 * Read and/or write a PMC. 3735 */ 3736 3737 case PMC_OP_PMCRW: 3738 { 3739 int adjri; 3740 struct pmc *pm; 3741 uint32_t cpu, ri; 3742 pmc_value_t oldvalue; 3743 struct pmc_binding pb; 3744 struct pmc_op_pmcrw prw; 3745 struct pmc_classdep *pcd; 3746 struct pmc_op_pmcrw *pprw; 3747 3748 PMC_DOWNGRADE_SX(); 3749 3750 if ((error = copyin(arg, &prw, sizeof(prw))) != 0) 3751 break; 3752 3753 ri = 0; 3754 PMCDBG2(PMC,OPS,1, "rw id=%d flags=0x%x", prw.pm_pmcid, 3755 prw.pm_flags); 3756 3757 /* must have at least one flag set */ 3758 if ((prw.pm_flags & (PMC_F_OLDVALUE|PMC_F_NEWVALUE)) == 0) { 3759 error = EINVAL; 3760 break; 3761 } 3762 3763 /* locate pmc descriptor */ 3764 if ((error = pmc_find_pmc(prw.pm_pmcid, &pm)) != 0) 3765 break; 3766 3767 /* Can't read a PMC that hasn't been started. */ 3768 if (pm->pm_state != PMC_STATE_ALLOCATED && 3769 pm->pm_state != PMC_STATE_STOPPED && 3770 pm->pm_state != PMC_STATE_RUNNING) { 3771 error = EINVAL; 3772 break; 3773 } 3774 3775 /* writing a new value is allowed only for 'STOPPED' pmcs */ 3776 if (pm->pm_state == PMC_STATE_RUNNING && 3777 (prw.pm_flags & PMC_F_NEWVALUE)) { 3778 error = EBUSY; 3779 break; 3780 } 3781 3782 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) { 3783 3784 /* 3785 * If this PMC is attached to its owner (i.e., 3786 * the process requesting this operation) and 3787 * is running, then attempt to get an 3788 * upto-date reading from hardware for a READ. 3789 * Writes are only allowed when the PMC is 3790 * stopped, so only update the saved value 3791 * field. 3792 * 3793 * If the PMC is not running, or is not 3794 * attached to its owner, read/write to the 3795 * savedvalue field. 3796 */ 3797 3798 ri = PMC_TO_ROWINDEX(pm); 3799 pcd = pmc_ri_to_classdep(md, ri, &adjri); 3800 3801 mtx_pool_lock_spin(pmc_mtxpool, pm); 3802 cpu = curthread->td_oncpu; 3803 3804 if (prw.pm_flags & PMC_F_OLDVALUE) { 3805 if ((pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) && 3806 (pm->pm_state == PMC_STATE_RUNNING)) 3807 error = (*pcd->pcd_read_pmc)(cpu, adjri, 3808 &oldvalue); 3809 else 3810 oldvalue = pm->pm_gv.pm_savedvalue; 3811 } 3812 if (prw.pm_flags & PMC_F_NEWVALUE) 3813 pm->pm_gv.pm_savedvalue = prw.pm_value; 3814 3815 mtx_pool_unlock_spin(pmc_mtxpool, pm); 3816 3817 } else { /* System mode PMCs */ 3818 cpu = PMC_TO_CPU(pm); 3819 ri = PMC_TO_ROWINDEX(pm); 3820 pcd = pmc_ri_to_classdep(md, ri, &adjri); 3821 3822 if (!pmc_cpu_is_active(cpu)) { 3823 error = ENXIO; 3824 break; 3825 } 3826 3827 /* move this thread to CPU 'cpu' */ 3828 pmc_save_cpu_binding(&pb); 3829 pmc_select_cpu(cpu); 3830 3831 critical_enter(); 3832 /* save old value */ 3833 if (prw.pm_flags & PMC_F_OLDVALUE) 3834 if ((error = (*pcd->pcd_read_pmc)(cpu, adjri, 3835 &oldvalue))) 3836 goto error; 3837 /* write out new value */ 3838 if (prw.pm_flags & PMC_F_NEWVALUE) 3839 error = (*pcd->pcd_write_pmc)(cpu, adjri, 3840 prw.pm_value); 3841 error: 3842 critical_exit(); 3843 pmc_restore_cpu_binding(&pb); 3844 if (error) 3845 break; 3846 } 3847 3848 pprw = (struct pmc_op_pmcrw *) arg; 3849 3850#ifdef HWPMC_DEBUG 3851 if (prw.pm_flags & PMC_F_NEWVALUE) 3852 PMCDBG3(PMC,OPS,2, "rw id=%d new %jx -> old %jx", 3853 ri, prw.pm_value, oldvalue); 3854 else if (prw.pm_flags & PMC_F_OLDVALUE) 3855 PMCDBG2(PMC,OPS,2, "rw id=%d -> old %jx", ri, oldvalue); 3856#endif 3857 3858 /* return old value if requested */ 3859 if (prw.pm_flags & PMC_F_OLDVALUE) 3860 if ((error = copyout(&oldvalue, &pprw->pm_value, 3861 sizeof(prw.pm_value)))) 3862 break; 3863 3864 } 3865 break; 3866 3867 3868 /* 3869 * Set the sampling rate for a sampling mode PMC and the 3870 * initial count for a counting mode PMC. 3871 */ 3872 3873 case PMC_OP_PMCSETCOUNT: 3874 { 3875 struct pmc *pm; 3876 struct pmc_op_pmcsetcount sc; 3877 3878 PMC_DOWNGRADE_SX(); 3879 3880 if ((error = copyin(arg, &sc, sizeof(sc))) != 0) 3881 break; 3882 3883 if ((error = pmc_find_pmc(sc.pm_pmcid, &pm)) != 0) 3884 break; 3885 3886 if (pm->pm_state == PMC_STATE_RUNNING) { 3887 error = EBUSY; 3888 break; 3889 } 3890 3891 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 3892 pm->pm_sc.pm_reloadcount = sc.pm_count; 3893 else 3894 pm->pm_sc.pm_initial = sc.pm_count; 3895 } 3896 break; 3897 3898 3899 /* 3900 * Start a PMC. 3901 */ 3902 3903 case PMC_OP_PMCSTART: 3904 { 3905 pmc_id_t pmcid; 3906 struct pmc *pm; 3907 struct pmc_op_simple sp; 3908 3909 sx_assert(&pmc_sx, SX_XLOCKED); 3910 3911 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 3912 break; 3913 3914 pmcid = sp.pm_pmcid; 3915 3916 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 3917 break; 3918 3919 KASSERT(pmcid == pm->pm_id, 3920 ("[pmc,%d] pmcid %x != id %x", __LINE__, 3921 pm->pm_id, pmcid)); 3922 3923 if (pm->pm_state == PMC_STATE_RUNNING) /* already running */ 3924 break; 3925 else if (pm->pm_state != PMC_STATE_STOPPED && 3926 pm->pm_state != PMC_STATE_ALLOCATED) { 3927 error = EINVAL; 3928 break; 3929 } 3930 3931 error = pmc_start(pm); 3932 } 3933 break; 3934 3935 3936 /* 3937 * Stop a PMC. 3938 */ 3939 3940 case PMC_OP_PMCSTOP: 3941 { 3942 pmc_id_t pmcid; 3943 struct pmc *pm; 3944 struct pmc_op_simple sp; 3945 3946 PMC_DOWNGRADE_SX(); 3947 3948 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 3949 break; 3950 3951 pmcid = sp.pm_pmcid; 3952 3953 /* 3954 * Mark the PMC as inactive and invoke the MD stop 3955 * routines if needed. 3956 */ 3957 3958 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 3959 break; 3960 3961 KASSERT(pmcid == pm->pm_id, 3962 ("[pmc,%d] pmc id %x != pmcid %x", __LINE__, 3963 pm->pm_id, pmcid)); 3964 3965 if (pm->pm_state == PMC_STATE_STOPPED) /* already stopped */ 3966 break; 3967 else if (pm->pm_state != PMC_STATE_RUNNING) { 3968 error = EINVAL; 3969 break; 3970 } 3971 3972 error = pmc_stop(pm); 3973 } 3974 break; 3975 3976 3977 /* 3978 * Write a user supplied value to the log file. 3979 */ 3980 3981 case PMC_OP_WRITELOG: 3982 { 3983 struct pmc_op_writelog wl; 3984 struct pmc_owner *po; 3985 3986 PMC_DOWNGRADE_SX(); 3987 3988 if ((error = copyin(arg, &wl, sizeof(wl))) != 0) 3989 break; 3990 3991 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 3992 error = EINVAL; 3993 break; 3994 } 3995 3996 if ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) { 3997 error = EINVAL; 3998 break; 3999 } 4000 4001 error = pmclog_process_userlog(po, &wl); 4002 } 4003 break; 4004 4005 4006 default: 4007 error = EINVAL; 4008 break; 4009 } 4010 4011 if (is_sx_locked != 0) { 4012 if (is_sx_downgraded) 4013 sx_sunlock(&pmc_sx); 4014 else 4015 sx_xunlock(&pmc_sx); 4016 } 4017 4018 if (error) 4019 atomic_add_int(&pmc_stats.pm_syscall_errors, 1); 4020 4021 PICKUP_GIANT(); 4022 4023 return error; 4024} 4025 4026/* 4027 * Helper functions 4028 */ 4029 4030 4031/* 4032 * Mark the thread as needing callchain capture and post an AST. The 4033 * actual callchain capture will be done in a context where it is safe 4034 * to take page faults. 4035 */ 4036 4037static void 4038pmc_post_callchain_callback(void) 4039{ 4040 struct thread *td; 4041 4042 td = curthread; 4043 4044 /* 4045 * If there is multiple PMCs for the same interrupt ignore new post 4046 */ 4047 if (td->td_pflags & TDP_CALLCHAIN) 4048 return; 4049 4050 /* 4051 * Mark this thread as needing callchain capture. 4052 * `td->td_pflags' will be safe to touch because this thread 4053 * was in user space when it was interrupted. 4054 */ 4055 td->td_pflags |= TDP_CALLCHAIN; 4056 4057 /* 4058 * Don't let this thread migrate between CPUs until callchain 4059 * capture completes. 4060 */ 4061 sched_pin(); 4062 4063 return; 4064} 4065 4066/* 4067 * Interrupt processing. 4068 * 4069 * Find a free slot in the per-cpu array of samples and capture the 4070 * current callchain there. If a sample was successfully added, a bit 4071 * is set in mask 'pmc_cpumask' denoting that the DO_SAMPLES hook 4072 * needs to be invoked from the clock handler. 4073 * 4074 * This function is meant to be called from an NMI handler. It cannot 4075 * use any of the locking primitives supplied by the OS. 4076 */ 4077 4078int 4079pmc_process_interrupt(int cpu, int ring, struct pmc *pm, struct trapframe *tf, 4080 int inuserspace) 4081{ 4082 int error, callchaindepth; 4083 struct thread *td; 4084 struct pmc_sample *ps; 4085 struct pmc_samplebuffer *psb; 4086 4087 error = 0; 4088 4089 /* 4090 * Allocate space for a sample buffer. 4091 */ 4092 psb = pmc_pcpu[cpu]->pc_sb[ring]; 4093 4094 ps = psb->ps_write; 4095 if (ps->ps_nsamples) { /* in use, reader hasn't caught up */ 4096 CPU_SET_ATOMIC(cpu, &pm->pm_stalled); 4097 atomic_add_int(&pmc_stats.pm_intr_bufferfull, 1); 4098 PMCDBG6(SAM,INT,1,"(spc) cpu=%d pm=%p tf=%p um=%d wr=%d rd=%d", 4099 cpu, pm, (void *) tf, inuserspace, 4100 (int) (psb->ps_write - psb->ps_samples), 4101 (int) (psb->ps_read - psb->ps_samples)); 4102 callchaindepth = 1; 4103 error = ENOMEM; 4104 goto done; 4105 } 4106 4107 4108 /* Fill in entry. */ 4109 PMCDBG6(SAM,INT,1,"cpu=%d pm=%p tf=%p um=%d wr=%d rd=%d", cpu, pm, 4110 (void *) tf, inuserspace, 4111 (int) (psb->ps_write - psb->ps_samples), 4112 (int) (psb->ps_read - psb->ps_samples)); 4113 4114 KASSERT(pm->pm_runcount >= 0, 4115 ("[pmc,%d] pm=%p runcount %d", __LINE__, (void *) pm, 4116 pm->pm_runcount)); 4117 4118 atomic_add_rel_int(&pm->pm_runcount, 1); /* hold onto PMC */ 4119 4120 ps->ps_pmc = pm; 4121 if ((td = curthread) && td->td_proc) 4122 ps->ps_pid = td->td_proc->p_pid; 4123 else 4124 ps->ps_pid = -1; 4125 ps->ps_cpu = cpu; 4126 ps->ps_td = td; 4127 ps->ps_flags = inuserspace ? PMC_CC_F_USERSPACE : 0; 4128 4129 callchaindepth = (pm->pm_flags & PMC_F_CALLCHAIN) ? 4130 pmc_callchaindepth : 1; 4131 4132 if (callchaindepth == 1) 4133 ps->ps_pc[0] = PMC_TRAPFRAME_TO_PC(tf); 4134 else { 4135 /* 4136 * Kernel stack traversals can be done immediately, 4137 * while we defer to an AST for user space traversals. 4138 */ 4139 if (!inuserspace) { 4140 callchaindepth = 4141 pmc_save_kernel_callchain(ps->ps_pc, 4142 callchaindepth, tf); 4143 } else { 4144 pmc_post_callchain_callback(); 4145 callchaindepth = PMC_SAMPLE_INUSE; 4146 } 4147 } 4148 4149 ps->ps_nsamples = callchaindepth; /* mark entry as in use */ 4150 4151 /* increment write pointer, modulo ring buffer size */ 4152 ps++; 4153 if (ps == psb->ps_fence) 4154 psb->ps_write = psb->ps_samples; 4155 else 4156 psb->ps_write = ps; 4157 4158 done: 4159 /* mark CPU as needing processing */ 4160 if (callchaindepth != PMC_SAMPLE_INUSE) 4161 CPU_SET_ATOMIC(cpu, &pmc_cpumask); 4162 4163 return (error); 4164} 4165 4166/* 4167 * Capture a user call chain. This function will be called from ast() 4168 * before control returns to userland and before the process gets 4169 * rescheduled. 4170 */ 4171 4172static void 4173pmc_capture_user_callchain(int cpu, int ring, struct trapframe *tf) 4174{ 4175 struct pmc *pm; 4176 struct thread *td; 4177 struct pmc_sample *ps, *ps_end; 4178 struct pmc_samplebuffer *psb; 4179#ifdef INVARIANTS 4180 int ncallchains; 4181#endif 4182 4183 psb = pmc_pcpu[cpu]->pc_sb[ring]; 4184 td = curthread; 4185 4186 KASSERT(td->td_pflags & TDP_CALLCHAIN, 4187 ("[pmc,%d] Retrieving callchain for thread that doesn't want it", 4188 __LINE__)); 4189 4190#ifdef INVARIANTS 4191 ncallchains = 0; 4192#endif 4193 4194 /* 4195 * Iterate through all deferred callchain requests. 4196 * Walk from the current read pointer to the current 4197 * write pointer. 4198 */ 4199 4200 ps = psb->ps_read; 4201 ps_end = psb->ps_write; 4202 do { 4203 if (ps->ps_nsamples != PMC_SAMPLE_INUSE) 4204 goto next; 4205 if (ps->ps_td != td) 4206 goto next; 4207 4208 KASSERT(ps->ps_cpu == cpu, 4209 ("[pmc,%d] cpu mismatch ps_cpu=%d pcpu=%d", __LINE__, 4210 ps->ps_cpu, PCPU_GET(cpuid))); 4211 4212 pm = ps->ps_pmc; 4213 4214 KASSERT(pm->pm_flags & PMC_F_CALLCHAIN, 4215 ("[pmc,%d] Retrieving callchain for PMC that doesn't " 4216 "want it", __LINE__)); 4217 4218 KASSERT(pm->pm_runcount > 0, 4219 ("[pmc,%d] runcount %d", __LINE__, pm->pm_runcount)); 4220 4221 /* 4222 * Retrieve the callchain and mark the sample buffer 4223 * as 'processable' by the timer tick sweep code. 4224 */ 4225 ps->ps_nsamples = pmc_save_user_callchain(ps->ps_pc, 4226 pmc_callchaindepth, tf); 4227 4228#ifdef INVARIANTS 4229 ncallchains++; 4230#endif 4231 4232next: 4233 /* increment the pointer, modulo sample ring size */ 4234 if (++ps == psb->ps_fence) 4235 ps = psb->ps_samples; 4236 } while (ps != ps_end); 4237 4238 KASSERT(ncallchains > 0, 4239 ("[pmc,%d] cpu %d didn't find a sample to collect", __LINE__, 4240 cpu)); 4241 4242 KASSERT(td->td_pinned == 1, 4243 ("[pmc,%d] invalid td_pinned value", __LINE__)); 4244 sched_unpin(); /* Can migrate safely now. */ 4245 4246 /* mark CPU as needing processing */ 4247 CPU_SET_ATOMIC(cpu, &pmc_cpumask); 4248 4249 return; 4250} 4251 4252/* 4253 * Process saved PC samples. 4254 */ 4255 4256static void 4257pmc_process_samples(int cpu, int ring) 4258{ 4259 struct pmc *pm; 4260 int adjri, n; 4261 struct thread *td; 4262 struct pmc_owner *po; 4263 struct pmc_sample *ps; 4264 struct pmc_classdep *pcd; 4265 struct pmc_samplebuffer *psb; 4266 4267 KASSERT(PCPU_GET(cpuid) == cpu, 4268 ("[pmc,%d] not on the correct CPU pcpu=%d cpu=%d", __LINE__, 4269 PCPU_GET(cpuid), cpu)); 4270 4271 psb = pmc_pcpu[cpu]->pc_sb[ring]; 4272 4273 for (n = 0; n < pmc_nsamples; n++) { /* bound on #iterations */ 4274 4275 ps = psb->ps_read; 4276 if (ps->ps_nsamples == PMC_SAMPLE_FREE) 4277 break; 4278 4279 pm = ps->ps_pmc; 4280 4281 KASSERT(pm->pm_runcount > 0, 4282 ("[pmc,%d] pm=%p runcount %d", __LINE__, (void *) pm, 4283 pm->pm_runcount)); 4284 4285 po = pm->pm_owner; 4286 4287 KASSERT(PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)), 4288 ("[pmc,%d] pmc=%p non-sampling mode=%d", __LINE__, 4289 pm, PMC_TO_MODE(pm))); 4290 4291 /* Ignore PMCs that have been switched off */ 4292 if (pm->pm_state != PMC_STATE_RUNNING) 4293 goto entrydone; 4294 4295 /* If there is a pending AST wait for completion */ 4296 if (ps->ps_nsamples == PMC_SAMPLE_INUSE) { 4297 /* Need a rescan at a later time. */ 4298 CPU_SET_ATOMIC(cpu, &pmc_cpumask); 4299 break; 4300 } 4301 4302 PMCDBG6(SAM,OPS,1,"cpu=%d pm=%p n=%d fl=%x wr=%d rd=%d", cpu, 4303 pm, ps->ps_nsamples, ps->ps_flags, 4304 (int) (psb->ps_write - psb->ps_samples), 4305 (int) (psb->ps_read - psb->ps_samples)); 4306 4307 /* 4308 * If this is a process-mode PMC that is attached to 4309 * its owner, and if the PC is in user mode, update 4310 * profiling statistics like timer-based profiling 4311 * would have done. 4312 */ 4313 if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) { 4314 if (ps->ps_flags & PMC_CC_F_USERSPACE) { 4315 td = FIRST_THREAD_IN_PROC(po->po_owner); 4316 addupc_intr(td, ps->ps_pc[0], 1); 4317 } 4318 goto entrydone; 4319 } 4320 4321 /* 4322 * Otherwise, this is either a sampling mode PMC that 4323 * is attached to a different process than its owner, 4324 * or a system-wide sampling PMC. Dispatch a log 4325 * entry to the PMC's owner process. 4326 */ 4327 pmclog_process_callchain(pm, ps); 4328 4329 entrydone: 4330 ps->ps_nsamples = 0; /* mark entry as free */ 4331 atomic_subtract_rel_int(&pm->pm_runcount, 1); 4332 4333 /* increment read pointer, modulo sample size */ 4334 if (++ps == psb->ps_fence) 4335 psb->ps_read = psb->ps_samples; 4336 else 4337 psb->ps_read = ps; 4338 } 4339 4340 atomic_add_int(&pmc_stats.pm_log_sweeps, 1); 4341 4342 /* Do not re-enable stalled PMCs if we failed to process any samples */ 4343 if (n == 0) 4344 return; 4345 4346 /* 4347 * Restart any stalled sampling PMCs on this CPU. 4348 * 4349 * If the NMI handler sets the pm_stalled field of a PMC after 4350 * the check below, we'll end up processing the stalled PMC at 4351 * the next hardclock tick. 4352 */ 4353 for (n = 0; n < md->pmd_npmc; n++) { 4354 pcd = pmc_ri_to_classdep(md, n, &adjri); 4355 KASSERT(pcd != NULL, 4356 ("[pmc,%d] null pcd ri=%d", __LINE__, n)); 4357 (void) (*pcd->pcd_get_config)(cpu,adjri,&pm); 4358 4359 if (pm == NULL || /* !cfg'ed */ 4360 pm->pm_state != PMC_STATE_RUNNING || /* !active */ 4361 !PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)) || /* !sampling */ 4362 !CPU_ISSET(cpu, &pm->pm_cpustate) || /* !desired */ 4363 !CPU_ISSET(cpu, &pm->pm_stalled)) /* !stalled */ 4364 continue; 4365 4366 CPU_CLR_ATOMIC(cpu, &pm->pm_stalled); 4367 (*pcd->pcd_start_pmc)(cpu, adjri); 4368 } 4369} 4370 4371/* 4372 * Event handlers. 4373 */ 4374 4375/* 4376 * Handle a process exit. 4377 * 4378 * Remove this process from all hash tables. If this process 4379 * owned any PMCs, turn off those PMCs and deallocate them, 4380 * removing any associations with target processes. 4381 * 4382 * This function will be called by the last 'thread' of a 4383 * process. 4384 * 4385 * XXX This eventhandler gets called early in the exit process. 4386 * Consider using a 'hook' invocation from thread_exit() or equivalent 4387 * spot. Another negative is that kse_exit doesn't seem to call 4388 * exit1() [??]. 4389 * 4390 */ 4391 4392static void 4393pmc_process_exit(void *arg __unused, struct proc *p) 4394{ 4395 struct pmc *pm; 4396 int adjri, cpu; 4397 unsigned int ri; 4398 int is_using_hwpmcs; 4399 struct pmc_owner *po; 4400 struct pmc_process *pp; 4401 struct pmc_classdep *pcd; 4402 pmc_value_t newvalue, tmp; 4403 4404 PROC_LOCK(p); 4405 is_using_hwpmcs = p->p_flag & P_HWPMC; 4406 PROC_UNLOCK(p); 4407 4408 /* 4409 * Log a sysexit event to all SS PMC owners. 4410 */ 4411 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 4412 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 4413 pmclog_process_sysexit(po, p->p_pid); 4414 4415 if (!is_using_hwpmcs) 4416 return; 4417 4418 PMC_GET_SX_XLOCK(); 4419 PMCDBG3(PRC,EXT,1,"process-exit proc=%p (%d, %s)", p, p->p_pid, 4420 p->p_comm); 4421 4422 /* 4423 * Since this code is invoked by the last thread in an exiting 4424 * process, we would have context switched IN at some prior 4425 * point. However, with PREEMPTION, kernel mode context 4426 * switches may happen any time, so we want to disable a 4427 * context switch OUT till we get any PMCs targetting this 4428 * process off the hardware. 4429 * 4430 * We also need to atomically remove this process' 4431 * entry from our target process hash table, using 4432 * PMC_FLAG_REMOVE. 4433 */ 4434 PMCDBG3(PRC,EXT,1, "process-exit proc=%p (%d, %s)", p, p->p_pid, 4435 p->p_comm); 4436 4437 critical_enter(); /* no preemption */ 4438 4439 cpu = curthread->td_oncpu; 4440 4441 if ((pp = pmc_find_process_descriptor(p, 4442 PMC_FLAG_REMOVE)) != NULL) { 4443 4444 PMCDBG2(PRC,EXT,2, 4445 "process-exit proc=%p pmc-process=%p", p, pp); 4446 4447 /* 4448 * The exiting process could the target of 4449 * some PMCs which will be running on 4450 * currently executing CPU. 4451 * 4452 * We need to turn these PMCs off like we 4453 * would do at context switch OUT time. 4454 */ 4455 for (ri = 0; ri < md->pmd_npmc; ri++) { 4456 4457 /* 4458 * Pick up the pmc pointer from hardware 4459 * state similar to the CSW_OUT code. 4460 */ 4461 pm = NULL; 4462 4463 pcd = pmc_ri_to_classdep(md, ri, &adjri); 4464 4465 (void) (*pcd->pcd_get_config)(cpu, adjri, &pm); 4466 4467 PMCDBG2(PRC,EXT,2, "ri=%d pm=%p", ri, pm); 4468 4469 if (pm == NULL || 4470 !PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) 4471 continue; 4472 4473 PMCDBG4(PRC,EXT,2, "ppmcs[%d]=%p pm=%p " 4474 "state=%d", ri, pp->pp_pmcs[ri].pp_pmc, 4475 pm, pm->pm_state); 4476 4477 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 4478 ("[pmc,%d] ri mismatch pmc(%d) ri(%d)", 4479 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 4480 4481 KASSERT(pm == pp->pp_pmcs[ri].pp_pmc, 4482 ("[pmc,%d] pm %p != pp_pmcs[%d] %p", 4483 __LINE__, pm, ri, pp->pp_pmcs[ri].pp_pmc)); 4484 4485 KASSERT(pm->pm_runcount > 0, 4486 ("[pmc,%d] bad runcount ri %d rc %d", 4487 __LINE__, ri, pm->pm_runcount)); 4488 4489 /* 4490 * Change desired state, and then stop if not 4491 * stalled. This two-step dance should avoid 4492 * race conditions where an interrupt re-enables 4493 * the PMC after this code has already checked 4494 * the pm_stalled flag. 4495 */ 4496 if (CPU_ISSET(cpu, &pm->pm_cpustate)) { 4497 CPU_CLR_ATOMIC(cpu, &pm->pm_cpustate); 4498 if (!CPU_ISSET(cpu, &pm->pm_stalled)) { 4499 (void) pcd->pcd_stop_pmc(cpu, adjri); 4500 pcd->pcd_read_pmc(cpu, adjri, 4501 &newvalue); 4502 tmp = newvalue - 4503 PMC_PCPU_SAVED(cpu,ri); 4504 4505 mtx_pool_lock_spin(pmc_mtxpool, pm); 4506 pm->pm_gv.pm_savedvalue += tmp; 4507 pp->pp_pmcs[ri].pp_pmcval += tmp; 4508 mtx_pool_unlock_spin(pmc_mtxpool, pm); 4509 } 4510 } 4511 4512 atomic_subtract_rel_int(&pm->pm_runcount,1); 4513 4514 KASSERT((int) pm->pm_runcount >= 0, 4515 ("[pmc,%d] runcount is %d", __LINE__, ri)); 4516 4517 (void) pcd->pcd_config_pmc(cpu, adjri, NULL); 4518 } 4519 4520 /* 4521 * Inform the MD layer of this pseudo "context switch 4522 * out" 4523 */ 4524 (void) md->pmd_switch_out(pmc_pcpu[cpu], pp); 4525 4526 critical_exit(); /* ok to be pre-empted now */ 4527 4528 /* 4529 * Unlink this process from the PMCs that are 4530 * targetting it. This will send a signal to 4531 * all PMC owner's whose PMCs are orphaned. 4532 * 4533 * Log PMC value at exit time if requested. 4534 */ 4535 for (ri = 0; ri < md->pmd_npmc; ri++) 4536 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) { 4537 if (pm->pm_flags & PMC_F_NEEDS_LOGFILE && 4538 PMC_IS_COUNTING_MODE(PMC_TO_MODE(pm))) 4539 pmclog_process_procexit(pm, pp); 4540 pmc_unlink_target_process(pm, pp); 4541 } 4542 free(pp, M_PMC); 4543 4544 } else 4545 critical_exit(); /* pp == NULL */ 4546 4547 4548 /* 4549 * If the process owned PMCs, free them up and free up 4550 * memory. 4551 */ 4552 if ((po = pmc_find_owner_descriptor(p)) != NULL) { 4553 pmc_remove_owner(po); 4554 pmc_destroy_owner_descriptor(po); 4555 } 4556 4557 sx_xunlock(&pmc_sx); 4558} 4559 4560/* 4561 * Handle a process fork. 4562 * 4563 * If the parent process 'p1' is under HWPMC monitoring, then copy 4564 * over any attached PMCs that have 'do_descendants' semantics. 4565 */ 4566 4567static void 4568pmc_process_fork(void *arg __unused, struct proc *p1, struct proc *newproc, 4569 int flags) 4570{ 4571 int is_using_hwpmcs; 4572 unsigned int ri; 4573 uint32_t do_descendants; 4574 struct pmc *pm; 4575 struct pmc_owner *po; 4576 struct pmc_process *ppnew, *ppold; 4577 4578 (void) flags; /* unused parameter */ 4579 4580 PROC_LOCK(p1); 4581 is_using_hwpmcs = p1->p_flag & P_HWPMC; 4582 PROC_UNLOCK(p1); 4583 4584 /* 4585 * If there are system-wide sampling PMCs active, we need to 4586 * log all fork events to their owner's logs. 4587 */ 4588 4589 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 4590 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 4591 pmclog_process_procfork(po, p1->p_pid, newproc->p_pid); 4592 4593 if (!is_using_hwpmcs) 4594 return; 4595 4596 PMC_GET_SX_XLOCK(); 4597 PMCDBG4(PMC,FRK,1, "process-fork proc=%p (%d, %s) -> %p", p1, 4598 p1->p_pid, p1->p_comm, newproc); 4599 4600 /* 4601 * If the parent process (curthread->td_proc) is a 4602 * target of any PMCs, look for PMCs that are to be 4603 * inherited, and link these into the new process 4604 * descriptor. 4605 */ 4606 if ((ppold = pmc_find_process_descriptor(curthread->td_proc, 4607 PMC_FLAG_NONE)) == NULL) 4608 goto done; /* nothing to do */ 4609 4610 do_descendants = 0; 4611 for (ri = 0; ri < md->pmd_npmc; ri++) 4612 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL) 4613 do_descendants |= pm->pm_flags & PMC_F_DESCENDANTS; 4614 if (do_descendants == 0) /* nothing to do */ 4615 goto done; 4616 4617 /* allocate a descriptor for the new process */ 4618 if ((ppnew = pmc_find_process_descriptor(newproc, 4619 PMC_FLAG_ALLOCATE)) == NULL) 4620 goto done; 4621 4622 /* 4623 * Run through all PMCs that were targeting the old process 4624 * and which specified F_DESCENDANTS and attach them to the 4625 * new process. 4626 * 4627 * Log the fork event to all owners of PMCs attached to this 4628 * process, if not already logged. 4629 */ 4630 for (ri = 0; ri < md->pmd_npmc; ri++) 4631 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL && 4632 (pm->pm_flags & PMC_F_DESCENDANTS)) { 4633 pmc_link_target_process(pm, ppnew); 4634 po = pm->pm_owner; 4635 if (po->po_sscount == 0 && 4636 po->po_flags & PMC_PO_OWNS_LOGFILE) 4637 pmclog_process_procfork(po, p1->p_pid, 4638 newproc->p_pid); 4639 } 4640 4641 /* 4642 * Now mark the new process as being tracked by this driver. 4643 */ 4644 PROC_LOCK(newproc); 4645 newproc->p_flag |= P_HWPMC; 4646 PROC_UNLOCK(newproc); 4647 4648 done: 4649 sx_xunlock(&pmc_sx); 4650} 4651 4652static void 4653pmc_kld_load(void *arg __unused, linker_file_t lf) 4654{ 4655 struct pmc_owner *po; 4656 4657 sx_slock(&pmc_sx); 4658 4659 /* 4660 * Notify owners of system sampling PMCs about KLD operations. 4661 */ 4662 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 4663 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 4664 pmclog_process_map_in(po, (pid_t) -1, 4665 (uintfptr_t) lf->address, lf->filename); 4666 4667 /* 4668 * TODO: Notify owners of (all) process-sampling PMCs too. 4669 */ 4670 4671 sx_sunlock(&pmc_sx); 4672} 4673 4674static void 4675pmc_kld_unload(void *arg __unused, const char *filename __unused, 4676 caddr_t address, size_t size) 4677{ 4678 struct pmc_owner *po; 4679 4680 sx_slock(&pmc_sx); 4681 4682 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 4683 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 4684 pmclog_process_map_out(po, (pid_t) -1, 4685 (uintfptr_t) address, (uintfptr_t) address + size); 4686 4687 /* 4688 * TODO: Notify owners of process-sampling PMCs. 4689 */ 4690 4691 sx_sunlock(&pmc_sx); 4692} 4693 4694/* 4695 * initialization 4696 */ 4697 4698static const char *pmc_name_of_pmcclass[] = { 4699#undef __PMC_CLASS 4700#define __PMC_CLASS(N) #N , 4701 __PMC_CLASSES() 4702}; 4703 4704/* 4705 * Base class initializer: allocate structure and set default classes. 4706 */ 4707struct pmc_mdep * 4708pmc_mdep_alloc(int nclasses) 4709{ 4710 struct pmc_mdep *md; 4711 int n; 4712 4713 /* SOFT + md classes */ 4714 n = 1 + nclasses; 4715 md = malloc(sizeof(struct pmc_mdep) + n * 4716 sizeof(struct pmc_classdep), M_PMC, M_WAITOK|M_ZERO); 4717 md->pmd_nclass = n; 4718 4719 /* Add base class. */ 4720 pmc_soft_initialize(md); 4721 return md; 4722} 4723 4724void 4725pmc_mdep_free(struct pmc_mdep *md) 4726{ 4727 pmc_soft_finalize(md); 4728 free(md, M_PMC); 4729} 4730 4731static int 4732generic_switch_in(struct pmc_cpu *pc, struct pmc_process *pp) 4733{ 4734 (void) pc; (void) pp; 4735 4736 return (0); 4737} 4738 4739static int 4740generic_switch_out(struct pmc_cpu *pc, struct pmc_process *pp) 4741{ 4742 (void) pc; (void) pp; 4743 4744 return (0); 4745} 4746 4747static struct pmc_mdep * 4748pmc_generic_cpu_initialize(void) 4749{ 4750 struct pmc_mdep *md; 4751 4752 md = pmc_mdep_alloc(0); 4753 4754 md->pmd_cputype = PMC_CPU_GENERIC; 4755 4756 md->pmd_pcpu_init = NULL; 4757 md->pmd_pcpu_fini = NULL; 4758 md->pmd_switch_in = generic_switch_in; 4759 md->pmd_switch_out = generic_switch_out; 4760 4761 return (md); 4762} 4763 4764static void 4765pmc_generic_cpu_finalize(struct pmc_mdep *md) 4766{ 4767 (void) md; 4768} 4769 4770 4771static int 4772pmc_initialize(void) 4773{ 4774 int c, cpu, error, n, ri; 4775 unsigned int maxcpu; 4776 struct pmc_binding pb; 4777 struct pmc_sample *ps; 4778 struct pmc_classdep *pcd; 4779 struct pmc_samplebuffer *sb; 4780 4781 md = NULL; 4782 error = 0; 4783 4784#ifdef HWPMC_DEBUG 4785 /* parse debug flags first */ 4786 if (TUNABLE_STR_FETCH(PMC_SYSCTL_NAME_PREFIX "debugflags", 4787 pmc_debugstr, sizeof(pmc_debugstr))) 4788 pmc_debugflags_parse(pmc_debugstr, 4789 pmc_debugstr+strlen(pmc_debugstr)); 4790#endif 4791 4792 PMCDBG1(MOD,INI,0, "PMC Initialize (version %x)", PMC_VERSION); 4793 4794 /* check kernel version */ 4795 if (pmc_kernel_version != PMC_VERSION) { 4796 if (pmc_kernel_version == 0) 4797 printf("hwpmc: this kernel has not been compiled with " 4798 "'options HWPMC_HOOKS'.\n"); 4799 else 4800 printf("hwpmc: kernel version (0x%x) does not match " 4801 "module version (0x%x).\n", pmc_kernel_version, 4802 PMC_VERSION); 4803 return EPROGMISMATCH; 4804 } 4805 4806 /* 4807 * check sysctl parameters 4808 */ 4809 4810 if (pmc_hashsize <= 0) { 4811 (void) printf("hwpmc: tunable \"hashsize\"=%d must be " 4812 "greater than zero.\n", pmc_hashsize); 4813 pmc_hashsize = PMC_HASH_SIZE; 4814 } 4815 4816 if (pmc_nsamples <= 0 || pmc_nsamples > 65535) { 4817 (void) printf("hwpmc: tunable \"nsamples\"=%d out of " 4818 "range.\n", pmc_nsamples); 4819 pmc_nsamples = PMC_NSAMPLES; 4820 } 4821 4822 if (pmc_callchaindepth <= 0 || 4823 pmc_callchaindepth > PMC_CALLCHAIN_DEPTH_MAX) { 4824 (void) printf("hwpmc: tunable \"callchaindepth\"=%d out of " 4825 "range - using %d.\n", pmc_callchaindepth, 4826 PMC_CALLCHAIN_DEPTH_MAX); 4827 pmc_callchaindepth = PMC_CALLCHAIN_DEPTH_MAX; 4828 } 4829 4830 md = pmc_md_initialize(); 4831 if (md == NULL) { 4832 /* Default to generic CPU. */ 4833 md = pmc_generic_cpu_initialize(); 4834 if (md == NULL) 4835 return (ENOSYS); 4836 } 4837 4838 KASSERT(md->pmd_nclass >= 1 && md->pmd_npmc >= 1, 4839 ("[pmc,%d] no classes or pmcs", __LINE__)); 4840 4841 /* Compute the map from row-indices to classdep pointers. */ 4842 pmc_rowindex_to_classdep = malloc(sizeof(struct pmc_classdep *) * 4843 md->pmd_npmc, M_PMC, M_WAITOK|M_ZERO); 4844 4845 for (n = 0; n < md->pmd_npmc; n++) 4846 pmc_rowindex_to_classdep[n] = NULL; 4847 for (ri = c = 0; c < md->pmd_nclass; c++) { 4848 pcd = &md->pmd_classdep[c]; 4849 for (n = 0; n < pcd->pcd_num; n++, ri++) 4850 pmc_rowindex_to_classdep[ri] = pcd; 4851 } 4852 4853 KASSERT(ri == md->pmd_npmc, 4854 ("[pmc,%d] npmc miscomputed: ri=%d, md->npmc=%d", __LINE__, 4855 ri, md->pmd_npmc)); 4856 4857 maxcpu = pmc_cpu_max(); 4858 4859 /* allocate space for the per-cpu array */ 4860 pmc_pcpu = malloc(maxcpu * sizeof(struct pmc_cpu *), M_PMC, 4861 M_WAITOK|M_ZERO); 4862 4863 /* per-cpu 'saved values' for managing process-mode PMCs */ 4864 pmc_pcpu_saved = malloc(sizeof(pmc_value_t) * maxcpu * md->pmd_npmc, 4865 M_PMC, M_WAITOK); 4866 4867 /* Perform CPU-dependent initialization. */ 4868 pmc_save_cpu_binding(&pb); 4869 error = 0; 4870 for (cpu = 0; error == 0 && cpu < maxcpu; cpu++) { 4871 if (!pmc_cpu_is_active(cpu)) 4872 continue; 4873 pmc_select_cpu(cpu); 4874 pmc_pcpu[cpu] = malloc(sizeof(struct pmc_cpu) + 4875 md->pmd_npmc * sizeof(struct pmc_hw *), M_PMC, 4876 M_WAITOK|M_ZERO); 4877 if (md->pmd_pcpu_init) 4878 error = md->pmd_pcpu_init(md, cpu); 4879 for (n = 0; error == 0 && n < md->pmd_nclass; n++) 4880 error = md->pmd_classdep[n].pcd_pcpu_init(md, cpu); 4881 } 4882 pmc_restore_cpu_binding(&pb); 4883 4884 if (error) 4885 return (error); 4886 4887 /* allocate space for the sample array */ 4888 for (cpu = 0; cpu < maxcpu; cpu++) { 4889 if (!pmc_cpu_is_active(cpu)) 4890 continue; 4891 4892 sb = malloc(sizeof(struct pmc_samplebuffer) + 4893 pmc_nsamples * sizeof(struct pmc_sample), M_PMC, 4894 M_WAITOK|M_ZERO); 4895 sb->ps_read = sb->ps_write = sb->ps_samples; 4896 sb->ps_fence = sb->ps_samples + pmc_nsamples; 4897 4898 KASSERT(pmc_pcpu[cpu] != NULL, 4899 ("[pmc,%d] cpu=%d Null per-cpu data", __LINE__, cpu)); 4900 4901 sb->ps_callchains = malloc(pmc_callchaindepth * pmc_nsamples * 4902 sizeof(uintptr_t), M_PMC, M_WAITOK|M_ZERO); 4903 4904 for (n = 0, ps = sb->ps_samples; n < pmc_nsamples; n++, ps++) 4905 ps->ps_pc = sb->ps_callchains + 4906 (n * pmc_callchaindepth); 4907 4908 pmc_pcpu[cpu]->pc_sb[PMC_HR] = sb; 4909 4910 sb = malloc(sizeof(struct pmc_samplebuffer) + 4911 pmc_nsamples * sizeof(struct pmc_sample), M_PMC, 4912 M_WAITOK|M_ZERO); 4913 sb->ps_read = sb->ps_write = sb->ps_samples; 4914 sb->ps_fence = sb->ps_samples + pmc_nsamples; 4915 4916 KASSERT(pmc_pcpu[cpu] != NULL, 4917 ("[pmc,%d] cpu=%d Null per-cpu data", __LINE__, cpu)); 4918 4919 sb->ps_callchains = malloc(pmc_callchaindepth * pmc_nsamples * 4920 sizeof(uintptr_t), M_PMC, M_WAITOK|M_ZERO); 4921 4922 for (n = 0, ps = sb->ps_samples; n < pmc_nsamples; n++, ps++) 4923 ps->ps_pc = sb->ps_callchains + 4924 (n * pmc_callchaindepth); 4925 4926 pmc_pcpu[cpu]->pc_sb[PMC_SR] = sb; 4927 } 4928 4929 /* allocate space for the row disposition array */ 4930 pmc_pmcdisp = malloc(sizeof(enum pmc_mode) * md->pmd_npmc, 4931 M_PMC, M_WAITOK|M_ZERO); 4932 4933 /* mark all PMCs as available */ 4934 for (n = 0; n < (int) md->pmd_npmc; n++) 4935 PMC_MARK_ROW_FREE(n); 4936 4937 /* allocate thread hash tables */ 4938 pmc_ownerhash = hashinit(pmc_hashsize, M_PMC, 4939 &pmc_ownerhashmask); 4940 4941 pmc_processhash = hashinit(pmc_hashsize, M_PMC, 4942 &pmc_processhashmask); 4943 mtx_init(&pmc_processhash_mtx, "pmc-process-hash", "pmc-leaf", 4944 MTX_SPIN); 4945 4946 LIST_INIT(&pmc_ss_owners); 4947 pmc_ss_count = 0; 4948 4949 /* allocate a pool of spin mutexes */ 4950 pmc_mtxpool = mtx_pool_create("pmc-leaf", pmc_mtxpool_size, 4951 MTX_SPIN); 4952 4953 PMCDBG4(MOD,INI,1, "pmc_ownerhash=%p, mask=0x%lx " 4954 "targethash=%p mask=0x%lx", pmc_ownerhash, pmc_ownerhashmask, 4955 pmc_processhash, pmc_processhashmask); 4956 4957 /* register process {exit,fork,exec} handlers */ 4958 pmc_exit_tag = EVENTHANDLER_REGISTER(process_exit, 4959 pmc_process_exit, NULL, EVENTHANDLER_PRI_ANY); 4960 pmc_fork_tag = EVENTHANDLER_REGISTER(process_fork, 4961 pmc_process_fork, NULL, EVENTHANDLER_PRI_ANY); 4962 4963 /* register kld event handlers */ 4964 pmc_kld_load_tag = EVENTHANDLER_REGISTER(kld_load, pmc_kld_load, 4965 NULL, EVENTHANDLER_PRI_ANY); 4966 pmc_kld_unload_tag = EVENTHANDLER_REGISTER(kld_unload, pmc_kld_unload, 4967 NULL, EVENTHANDLER_PRI_ANY); 4968 4969 /* initialize logging */ 4970 pmclog_initialize(); 4971 4972 /* set hook functions */ 4973 pmc_intr = md->pmd_intr; 4974 pmc_hook = pmc_hook_handler; 4975 4976 if (error == 0) { 4977 printf(PMC_MODULE_NAME ":"); 4978 for (n = 0; n < (int) md->pmd_nclass; n++) { 4979 pcd = &md->pmd_classdep[n]; 4980 printf(" %s/%d/%d/0x%b", 4981 pmc_name_of_pmcclass[pcd->pcd_class], 4982 pcd->pcd_num, 4983 pcd->pcd_width, 4984 pcd->pcd_caps, 4985 "\20" 4986 "\1INT\2USR\3SYS\4EDG\5THR" 4987 "\6REA\7WRI\10INV\11QUA\12PRC" 4988 "\13TAG\14CSC"); 4989 } 4990 printf("\n"); 4991 } 4992 4993 return (error); 4994} 4995 4996/* prepare to be unloaded */ 4997static void 4998pmc_cleanup(void) 4999{ 5000 int c, cpu; 5001 unsigned int maxcpu; 5002 struct pmc_ownerhash *ph; 5003 struct pmc_owner *po, *tmp; 5004 struct pmc_binding pb; 5005#ifdef HWPMC_DEBUG 5006 struct pmc_processhash *prh; 5007#endif 5008 5009 PMCDBG0(MOD,INI,0, "cleanup"); 5010 5011 /* switch off sampling */ 5012 CPU_ZERO(&pmc_cpumask); 5013 pmc_intr = NULL; 5014 5015 sx_xlock(&pmc_sx); 5016 if (pmc_hook == NULL) { /* being unloaded already */ 5017 sx_xunlock(&pmc_sx); 5018 return; 5019 } 5020 5021 pmc_hook = NULL; /* prevent new threads from entering module */ 5022 5023 /* deregister event handlers */ 5024 EVENTHANDLER_DEREGISTER(process_fork, pmc_fork_tag); 5025 EVENTHANDLER_DEREGISTER(process_exit, pmc_exit_tag); 5026 EVENTHANDLER_DEREGISTER(kld_load, pmc_kld_load_tag); 5027 EVENTHANDLER_DEREGISTER(kld_unload, pmc_kld_unload_tag); 5028 5029 /* send SIGBUS to all owner threads, free up allocations */ 5030 if (pmc_ownerhash) 5031 for (ph = pmc_ownerhash; 5032 ph <= &pmc_ownerhash[pmc_ownerhashmask]; 5033 ph++) { 5034 LIST_FOREACH_SAFE(po, ph, po_next, tmp) { 5035 pmc_remove_owner(po); 5036 5037 /* send SIGBUS to owner processes */ 5038 PMCDBG3(MOD,INI,2, "cleanup signal proc=%p " 5039 "(%d, %s)", po->po_owner, 5040 po->po_owner->p_pid, 5041 po->po_owner->p_comm); 5042 5043 PROC_LOCK(po->po_owner); 5044 kern_psignal(po->po_owner, SIGBUS); 5045 PROC_UNLOCK(po->po_owner); 5046 5047 pmc_destroy_owner_descriptor(po); 5048 } 5049 } 5050 5051 /* reclaim allocated data structures */ 5052 if (pmc_mtxpool) 5053 mtx_pool_destroy(&pmc_mtxpool); 5054 5055 mtx_destroy(&pmc_processhash_mtx); 5056 if (pmc_processhash) { 5057#ifdef HWPMC_DEBUG 5058 struct pmc_process *pp; 5059 5060 PMCDBG0(MOD,INI,3, "destroy process hash"); 5061 for (prh = pmc_processhash; 5062 prh <= &pmc_processhash[pmc_processhashmask]; 5063 prh++) 5064 LIST_FOREACH(pp, prh, pp_next) 5065 PMCDBG1(MOD,INI,3, "pid=%d", pp->pp_proc->p_pid); 5066#endif 5067 5068 hashdestroy(pmc_processhash, M_PMC, pmc_processhashmask); 5069 pmc_processhash = NULL; 5070 } 5071 5072 if (pmc_ownerhash) { 5073 PMCDBG0(MOD,INI,3, "destroy owner hash"); 5074 hashdestroy(pmc_ownerhash, M_PMC, pmc_ownerhashmask); 5075 pmc_ownerhash = NULL; 5076 } 5077 5078 KASSERT(LIST_EMPTY(&pmc_ss_owners), 5079 ("[pmc,%d] Global SS owner list not empty", __LINE__)); 5080 KASSERT(pmc_ss_count == 0, 5081 ("[pmc,%d] Global SS count not empty", __LINE__)); 5082 5083 /* do processor and pmc-class dependent cleanup */ 5084 maxcpu = pmc_cpu_max(); 5085 5086 PMCDBG0(MOD,INI,3, "md cleanup"); 5087 if (md) { 5088 pmc_save_cpu_binding(&pb); 5089 for (cpu = 0; cpu < maxcpu; cpu++) { 5090 PMCDBG2(MOD,INI,1,"pmc-cleanup cpu=%d pcs=%p", 5091 cpu, pmc_pcpu[cpu]); 5092 if (!pmc_cpu_is_active(cpu) || pmc_pcpu[cpu] == NULL) 5093 continue; 5094 pmc_select_cpu(cpu); 5095 for (c = 0; c < md->pmd_nclass; c++) 5096 md->pmd_classdep[c].pcd_pcpu_fini(md, cpu); 5097 if (md->pmd_pcpu_fini) 5098 md->pmd_pcpu_fini(md, cpu); 5099 } 5100 5101 if (md->pmd_cputype == PMC_CPU_GENERIC) 5102 pmc_generic_cpu_finalize(md); 5103 else 5104 pmc_md_finalize(md); 5105 5106 pmc_mdep_free(md); 5107 md = NULL; 5108 pmc_restore_cpu_binding(&pb); 5109 } 5110 5111 /* Free per-cpu descriptors. */ 5112 for (cpu = 0; cpu < maxcpu; cpu++) { 5113 if (!pmc_cpu_is_active(cpu)) 5114 continue; 5115 KASSERT(pmc_pcpu[cpu]->pc_sb[PMC_HR] != NULL, 5116 ("[pmc,%d] Null hw cpu sample buffer cpu=%d", __LINE__, 5117 cpu)); 5118 KASSERT(pmc_pcpu[cpu]->pc_sb[PMC_SR] != NULL, 5119 ("[pmc,%d] Null sw cpu sample buffer cpu=%d", __LINE__, 5120 cpu)); 5121 free(pmc_pcpu[cpu]->pc_sb[PMC_HR]->ps_callchains, M_PMC); 5122 free(pmc_pcpu[cpu]->pc_sb[PMC_HR], M_PMC); 5123 free(pmc_pcpu[cpu]->pc_sb[PMC_SR]->ps_callchains, M_PMC); 5124 free(pmc_pcpu[cpu]->pc_sb[PMC_SR], M_PMC); 5125 free(pmc_pcpu[cpu], M_PMC); 5126 } 5127 5128 free(pmc_pcpu, M_PMC); 5129 pmc_pcpu = NULL; 5130 5131 free(pmc_pcpu_saved, M_PMC); 5132 pmc_pcpu_saved = NULL; 5133 5134 if (pmc_pmcdisp) { 5135 free(pmc_pmcdisp, M_PMC); 5136 pmc_pmcdisp = NULL; 5137 } 5138 5139 if (pmc_rowindex_to_classdep) { 5140 free(pmc_rowindex_to_classdep, M_PMC); 5141 pmc_rowindex_to_classdep = NULL; 5142 } 5143 5144 pmclog_shutdown(); 5145 5146 sx_xunlock(&pmc_sx); /* we are done */ 5147} 5148 5149/* 5150 * The function called at load/unload. 5151 */ 5152 5153static int 5154load (struct module *module __unused, int cmd, void *arg __unused) 5155{ 5156 int error; 5157 5158 error = 0; 5159 5160 switch (cmd) { 5161 case MOD_LOAD : 5162 /* initialize the subsystem */ 5163 error = pmc_initialize(); 5164 if (error != 0) 5165 break; 5166 PMCDBG2(MOD,INI,1, "syscall=%d maxcpu=%d", 5167 pmc_syscall_num, pmc_cpu_max()); 5168 break; 5169 5170 5171 case MOD_UNLOAD : 5172 case MOD_SHUTDOWN: 5173 pmc_cleanup(); 5174 PMCDBG0(MOD,INI,1, "unloaded"); 5175 break; 5176 5177 default : 5178 error = EINVAL; /* XXX should panic(9) */ 5179 break; 5180 } 5181 5182 return error; 5183} 5184 5185/* memory pool */ 5186MALLOC_DEFINE(M_PMC, "pmc", "Memory space for the PMC module"); 5187