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