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 .sy_narg = 2, 315 .sy_call = pmc_syscall_handler, 316 }; 317 318 static struct syscall_module_data pmc_syscall_mod = { 319 .chainevh = load, 320 .chainarg = NULL, 321 .offset = &pmc_syscall_num, 322 .new_sysent = &pmc_sysent, 323 .old_sysent = { .sy_narg = 0, .sy_call = NULL }, 324 .flags = SY_THR_STATIC_KLD, 325 }; 326 327 static moduledata_t pmc_mod = { 328 .name = PMC_MODULE_NAME, 329 .evhand = syscall_module_handler, 330 .priv = &pmc_syscall_mod, 331 }; 332 333 #ifdef EARLY_AP_STARTUP 334 DECLARE_MODULE(pmc, pmc_mod, SI_SUB_SYSCALLS, SI_ORDER_ANY); 335 #else 336 DECLARE_MODULE(pmc, pmc_mod, SI_SUB_SMP, SI_ORDER_ANY); 337 #endif 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 if (p->p_flag & P_KPROC) { 1013 fullpath = kernelname; 1014 freepath = NULL; 1015 } else { 1016 pmc_getfilename(p->p_textvp, &fullpath, &freepath); 1017 pmclog_process_pmcattach(pm, p->p_pid, fullpath); 1018 } 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 targeting 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] weird 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 1286 /* 1287 * Use the saved value calculated after the most recent 1288 * thread switch out to start this counter. Reset 1289 * the saved count in case another thread from this 1290 * process switches in before any threads switch out. 1291 */ 1292 newvalue = PMC_PCPU_SAVED(cpu,ri) = 1293 pp->pp_pmcs[ri].pp_pmcval; 1294 pp->pp_pmcs[ri].pp_pmcval = pm->pm_sc.pm_reloadcount; 1295 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1296 } else { 1297 KASSERT(PMC_TO_MODE(pm) == PMC_MODE_TC, 1298 ("[pmc,%d] illegal mode=%d", __LINE__, 1299 PMC_TO_MODE(pm))); 1300 mtx_pool_lock_spin(pmc_mtxpool, pm); 1301 newvalue = PMC_PCPU_SAVED(cpu, ri) = 1302 pm->pm_gv.pm_savedvalue; 1303 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1304 } 1305 1306 PMCDBG3(CSW,SWI,1,"cpu=%d ri=%d new=%jd", cpu, ri, newvalue); 1307 1308 pcd->pcd_write_pmc(cpu, adjri, newvalue); 1309 1310 /* If a sampling mode PMC, reset stalled state. */ 1311 if (PMC_TO_MODE(pm) == PMC_MODE_TS) 1312 CPU_CLR_ATOMIC(cpu, &pm->pm_stalled); 1313 1314 /* Indicate that we desire this to run. */ 1315 CPU_SET_ATOMIC(cpu, &pm->pm_cpustate); 1316 1317 /* Start the PMC. */ 1318 pcd->pcd_start_pmc(cpu, adjri); 1319 } 1320 1321 /* 1322 * perform any other architecture/cpu dependent thread 1323 * switch-in actions. 1324 */ 1325 1326 (void) (*md->pmd_switch_in)(pc, pp); 1327 1328 critical_exit(); 1329 1330 } 1331 1332 /* 1333 * Thread context switch OUT. 1334 */ 1335 1336 static void 1337 pmc_process_csw_out(struct thread *td) 1338 { 1339 int cpu; 1340 int64_t tmp; 1341 struct pmc *pm; 1342 struct proc *p; 1343 enum pmc_mode mode; 1344 struct pmc_cpu *pc; 1345 pmc_value_t newvalue; 1346 unsigned int adjri, ri; 1347 struct pmc_process *pp; 1348 struct pmc_classdep *pcd; 1349 1350 1351 /* 1352 * Locate our process descriptor; this may be NULL if 1353 * this process is exiting and we have already removed 1354 * the process from the target process table. 1355 * 1356 * Note that due to kernel preemption, multiple 1357 * context switches may happen while the process is 1358 * exiting. 1359 * 1360 * Note also that if the target process cannot be 1361 * found we still need to deconfigure any PMCs that 1362 * are currently running on hardware. 1363 */ 1364 1365 p = td->td_proc; 1366 pp = pmc_find_process_descriptor(p, PMC_FLAG_NONE); 1367 1368 /* 1369 * save PMCs 1370 */ 1371 1372 critical_enter(); 1373 1374 cpu = PCPU_GET(cpuid); /* td->td_oncpu is invalid */ 1375 1376 PMCDBG5(CSW,SWO,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p, 1377 p->p_pid, p->p_comm, pp); 1378 1379 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 1380 ("[pmc,%d weird CPU id %d", __LINE__, cpu)); 1381 1382 pc = pmc_pcpu[cpu]; 1383 1384 /* 1385 * When a PMC gets unlinked from a target PMC, it will 1386 * be removed from the target's pp_pmc[] array. 1387 * 1388 * However, on a MP system, the target could have been 1389 * executing on another CPU at the time of the unlink. 1390 * So, at context switch OUT time, we need to look at 1391 * the hardware to determine if a PMC is scheduled on 1392 * it. 1393 */ 1394 1395 for (ri = 0; ri < md->pmd_npmc; ri++) { 1396 1397 pcd = pmc_ri_to_classdep(md, ri, &adjri); 1398 pm = NULL; 1399 (void) (*pcd->pcd_get_config)(cpu, adjri, &pm); 1400 1401 if (pm == NULL) /* nothing at this row index */ 1402 continue; 1403 1404 mode = PMC_TO_MODE(pm); 1405 if (!PMC_IS_VIRTUAL_MODE(mode)) 1406 continue; /* not a process virtual PMC */ 1407 1408 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 1409 ("[pmc,%d] ri mismatch pmc(%d) ri(%d)", 1410 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 1411 1412 /* 1413 * Change desired state, and then stop if not stalled. 1414 * This two-step dance should avoid race conditions where 1415 * an interrupt re-enables the PMC after this code has 1416 * already checked the pm_stalled flag. 1417 */ 1418 CPU_CLR_ATOMIC(cpu, &pm->pm_cpustate); 1419 if (!CPU_ISSET(cpu, &pm->pm_stalled)) 1420 pcd->pcd_stop_pmc(cpu, adjri); 1421 1422 /* reduce this PMC's runcount */ 1423 atomic_subtract_rel_int(&pm->pm_runcount, 1); 1424 1425 /* 1426 * If this PMC is associated with this process, 1427 * save the reading. 1428 */ 1429 1430 if (pm->pm_state != PMC_STATE_DELETED && pp != NULL && 1431 pp->pp_pmcs[ri].pp_pmc != NULL) { 1432 KASSERT(pm == pp->pp_pmcs[ri].pp_pmc, 1433 ("[pmc,%d] pm %p != pp_pmcs[%d] %p", __LINE__, 1434 pm, ri, pp->pp_pmcs[ri].pp_pmc)); 1435 1436 KASSERT(pp->pp_refcnt > 0, 1437 ("[pmc,%d] pp refcnt = %d", __LINE__, 1438 pp->pp_refcnt)); 1439 1440 pcd->pcd_read_pmc(cpu, adjri, &newvalue); 1441 1442 if (mode == PMC_MODE_TS) { 1443 PMCDBG3(CSW,SWO,1,"cpu=%d ri=%d tmp=%jd (samp)", 1444 cpu, ri, PMC_PCPU_SAVED(cpu,ri) - newvalue); 1445 1446 /* 1447 * For sampling process-virtual PMCs, 1448 * newvalue is the number of events to be seen 1449 * until the next sampling interrupt. 1450 * We can just add the events left from this 1451 * invocation to the counter, then adjust 1452 * in case we overflow our range. 1453 * 1454 * (Recall that we reload the counter every 1455 * time we use it.) 1456 */ 1457 mtx_pool_lock_spin(pmc_mtxpool, pm); 1458 1459 pp->pp_pmcs[ri].pp_pmcval += newvalue; 1460 if (pp->pp_pmcs[ri].pp_pmcval > 1461 pm->pm_sc.pm_reloadcount) 1462 pp->pp_pmcs[ri].pp_pmcval -= 1463 pm->pm_sc.pm_reloadcount; 1464 KASSERT(pp->pp_pmcs[ri].pp_pmcval > 0 && 1465 pp->pp_pmcs[ri].pp_pmcval <= 1466 pm->pm_sc.pm_reloadcount, 1467 ("[pmc,%d] pp_pmcval outside of expected " 1468 "range cpu=%d ri=%d pp_pmcval=%jx " 1469 "pm_reloadcount=%jx", __LINE__, cpu, ri, 1470 pp->pp_pmcs[ri].pp_pmcval, 1471 pm->pm_sc.pm_reloadcount)); 1472 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1473 1474 } else { 1475 tmp = newvalue - PMC_PCPU_SAVED(cpu,ri); 1476 1477 PMCDBG3(CSW,SWO,1,"cpu=%d ri=%d tmp=%jd (count)", 1478 cpu, ri, tmp); 1479 1480 /* 1481 * For counting process-virtual PMCs, 1482 * we expect the count to be 1483 * increasing monotonically, modulo a 64 1484 * bit wraparound. 1485 */ 1486 KASSERT(tmp >= 0, 1487 ("[pmc,%d] negative increment cpu=%d " 1488 "ri=%d newvalue=%jx saved=%jx " 1489 "incr=%jx", __LINE__, cpu, ri, 1490 newvalue, PMC_PCPU_SAVED(cpu,ri), tmp)); 1491 1492 mtx_pool_lock_spin(pmc_mtxpool, pm); 1493 pm->pm_gv.pm_savedvalue += tmp; 1494 pp->pp_pmcs[ri].pp_pmcval += tmp; 1495 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1496 1497 if (pm->pm_flags & PMC_F_LOG_PROCCSW) 1498 pmclog_process_proccsw(pm, pp, tmp); 1499 } 1500 } 1501 1502 /* mark hardware as free */ 1503 pcd->pcd_config_pmc(cpu, adjri, NULL); 1504 } 1505 1506 /* 1507 * perform any other architecture/cpu dependent thread 1508 * switch out functions. 1509 */ 1510 1511 (void) (*md->pmd_switch_out)(pc, pp); 1512 1513 critical_exit(); 1514 } 1515 1516 /* 1517 * A mapping change for a process. 1518 */ 1519 1520 static void 1521 pmc_process_mmap(struct thread *td, struct pmckern_map_in *pkm) 1522 { 1523 int ri; 1524 pid_t pid; 1525 char *fullpath, *freepath; 1526 const struct pmc *pm; 1527 struct pmc_owner *po; 1528 const struct pmc_process *pp; 1529 1530 freepath = fullpath = NULL; 1531 pmc_getfilename((struct vnode *) pkm->pm_file, &fullpath, &freepath); 1532 1533 pid = td->td_proc->p_pid; 1534 1535 /* Inform owners of all system-wide sampling PMCs. */ 1536 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1537 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1538 pmclog_process_map_in(po, pid, pkm->pm_address, fullpath); 1539 1540 if ((pp = pmc_find_process_descriptor(td->td_proc, 0)) == NULL) 1541 goto done; 1542 1543 /* 1544 * Inform sampling PMC owners tracking this process. 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_in(pm->pm_owner, 1550 pid, pkm->pm_address, fullpath); 1551 1552 done: 1553 if (freepath) 1554 free(freepath, M_TEMP); 1555 } 1556 1557 1558 /* 1559 * Log an munmap request. 1560 */ 1561 1562 static void 1563 pmc_process_munmap(struct thread *td, struct pmckern_map_out *pkm) 1564 { 1565 int ri; 1566 pid_t pid; 1567 struct pmc_owner *po; 1568 const struct pmc *pm; 1569 const struct pmc_process *pp; 1570 1571 pid = td->td_proc->p_pid; 1572 1573 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1574 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1575 pmclog_process_map_out(po, pid, pkm->pm_address, 1576 pkm->pm_address + pkm->pm_size); 1577 1578 if ((pp = pmc_find_process_descriptor(td->td_proc, 0)) == NULL) 1579 return; 1580 1581 for (ri = 0; ri < md->pmd_npmc; ri++) 1582 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL && 1583 PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 1584 pmclog_process_map_out(pm->pm_owner, pid, 1585 pkm->pm_address, pkm->pm_address + pkm->pm_size); 1586 } 1587 1588 /* 1589 * Log mapping information about the kernel. 1590 */ 1591 1592 static void 1593 pmc_log_kernel_mappings(struct pmc *pm) 1594 { 1595 struct pmc_owner *po; 1596 struct pmckern_map_in *km, *kmbase; 1597 1598 sx_assert(&pmc_sx, SX_LOCKED); 1599 KASSERT(PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)), 1600 ("[pmc,%d] non-sampling PMC (%p) desires mapping information", 1601 __LINE__, (void *) pm)); 1602 1603 po = pm->pm_owner; 1604 1605 if (po->po_flags & PMC_PO_INITIAL_MAPPINGS_DONE) 1606 return; 1607 1608 /* 1609 * Log the current set of kernel modules. 1610 */ 1611 kmbase = linker_hwpmc_list_objects(); 1612 for (km = kmbase; km->pm_file != NULL; km++) { 1613 PMCDBG2(LOG,REG,1,"%s %p", (char *) km->pm_file, 1614 (void *) km->pm_address); 1615 pmclog_process_map_in(po, (pid_t) -1, km->pm_address, 1616 km->pm_file); 1617 } 1618 free(kmbase, M_LINKER); 1619 1620 po->po_flags |= PMC_PO_INITIAL_MAPPINGS_DONE; 1621 } 1622 1623 /* 1624 * Log the mappings for a single process. 1625 */ 1626 1627 static void 1628 pmc_log_process_mappings(struct pmc_owner *po, struct proc *p) 1629 { 1630 vm_map_t map; 1631 struct vnode *vp; 1632 struct vmspace *vm; 1633 vm_map_entry_t entry; 1634 vm_offset_t last_end; 1635 u_int last_timestamp; 1636 struct vnode *last_vp; 1637 vm_offset_t start_addr; 1638 vm_object_t obj, lobj, tobj; 1639 char *fullpath, *freepath; 1640 1641 last_vp = NULL; 1642 last_end = (vm_offset_t) 0; 1643 fullpath = freepath = NULL; 1644 1645 if ((vm = vmspace_acquire_ref(p)) == NULL) 1646 return; 1647 1648 map = &vm->vm_map; 1649 vm_map_lock_read(map); 1650 1651 for (entry = map->header.next; entry != &map->header; entry = entry->next) { 1652 1653 if (entry == NULL) { 1654 PMCDBG2(LOG,OPS,2, "hwpmc: vm_map entry unexpectedly " 1655 "NULL! pid=%d vm_map=%p\n", p->p_pid, map); 1656 break; 1657 } 1658 1659 /* 1660 * We only care about executable map entries. 1661 */ 1662 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) || 1663 !(entry->protection & VM_PROT_EXECUTE) || 1664 (entry->object.vm_object == NULL)) { 1665 continue; 1666 } 1667 1668 obj = entry->object.vm_object; 1669 VM_OBJECT_RLOCK(obj); 1670 1671 /* 1672 * Walk the backing_object list to find the base 1673 * (non-shadowed) vm_object. 1674 */ 1675 for (lobj = tobj = obj; tobj != NULL; tobj = tobj->backing_object) { 1676 if (tobj != obj) 1677 VM_OBJECT_RLOCK(tobj); 1678 if (lobj != obj) 1679 VM_OBJECT_RUNLOCK(lobj); 1680 lobj = tobj; 1681 } 1682 1683 /* 1684 * At this point lobj is the base vm_object and it is locked. 1685 */ 1686 if (lobj == NULL) { 1687 PMCDBG3(LOG,OPS,2, "hwpmc: lobj unexpectedly NULL! pid=%d " 1688 "vm_map=%p vm_obj=%p\n", p->p_pid, map, obj); 1689 VM_OBJECT_RUNLOCK(obj); 1690 continue; 1691 } 1692 1693 vp = vm_object_vnode(lobj); 1694 if (vp == NULL) { 1695 if (lobj != obj) 1696 VM_OBJECT_RUNLOCK(lobj); 1697 VM_OBJECT_RUNLOCK(obj); 1698 continue; 1699 } 1700 1701 /* 1702 * Skip contiguous regions that point to the same 1703 * vnode, so we don't emit redundant MAP-IN 1704 * directives. 1705 */ 1706 if (entry->start == last_end && vp == last_vp) { 1707 last_end = entry->end; 1708 if (lobj != obj) 1709 VM_OBJECT_RUNLOCK(lobj); 1710 VM_OBJECT_RUNLOCK(obj); 1711 continue; 1712 } 1713 1714 /* 1715 * We don't want to keep the proc's vm_map or this 1716 * vm_object locked while we walk the pathname, since 1717 * vn_fullpath() can sleep. However, if we drop the 1718 * lock, it's possible for concurrent activity to 1719 * modify the vm_map list. To protect against this, 1720 * we save the vm_map timestamp before we release the 1721 * lock, and check it after we reacquire the lock 1722 * below. 1723 */ 1724 start_addr = entry->start; 1725 last_end = entry->end; 1726 last_timestamp = map->timestamp; 1727 vm_map_unlock_read(map); 1728 1729 vref(vp); 1730 if (lobj != obj) 1731 VM_OBJECT_RUNLOCK(lobj); 1732 1733 VM_OBJECT_RUNLOCK(obj); 1734 1735 freepath = NULL; 1736 pmc_getfilename(vp, &fullpath, &freepath); 1737 last_vp = vp; 1738 1739 vrele(vp); 1740 1741 vp = NULL; 1742 pmclog_process_map_in(po, p->p_pid, start_addr, fullpath); 1743 if (freepath) 1744 free(freepath, M_TEMP); 1745 1746 vm_map_lock_read(map); 1747 1748 /* 1749 * If our saved timestamp doesn't match, this means 1750 * that the vm_map was modified out from under us and 1751 * we can't trust our current "entry" pointer. Do a 1752 * new lookup for this entry. If there is no entry 1753 * for this address range, vm_map_lookup_entry() will 1754 * return the previous one, so we always want to go to 1755 * entry->next on the next loop iteration. 1756 * 1757 * There is an edge condition here that can occur if 1758 * there is no entry at or before this address. In 1759 * this situation, vm_map_lookup_entry returns 1760 * &map->header, which would cause our loop to abort 1761 * without processing the rest of the map. However, 1762 * in practice this will never happen for process 1763 * vm_map. This is because the executable's text 1764 * segment is the first mapping in the proc's address 1765 * space, and this mapping is never removed until the 1766 * process exits, so there will always be a non-header 1767 * entry at or before the requested address for 1768 * vm_map_lookup_entry to return. 1769 */ 1770 if (map->timestamp != last_timestamp) 1771 vm_map_lookup_entry(map, last_end - 1, &entry); 1772 } 1773 1774 vm_map_unlock_read(map); 1775 vmspace_free(vm); 1776 return; 1777 } 1778 1779 /* 1780 * Log mappings for all processes in the system. 1781 */ 1782 1783 static void 1784 pmc_log_all_process_mappings(struct pmc_owner *po) 1785 { 1786 struct proc *p, *top; 1787 1788 sx_assert(&pmc_sx, SX_XLOCKED); 1789 1790 if ((p = pfind(1)) == NULL) 1791 panic("[pmc,%d] Cannot find init", __LINE__); 1792 1793 PROC_UNLOCK(p); 1794 1795 sx_slock(&proctree_lock); 1796 1797 top = p; 1798 1799 for (;;) { 1800 pmc_log_process_mappings(po, p); 1801 if (!LIST_EMPTY(&p->p_children)) 1802 p = LIST_FIRST(&p->p_children); 1803 else for (;;) { 1804 if (p == top) 1805 goto done; 1806 if (LIST_NEXT(p, p_sibling)) { 1807 p = LIST_NEXT(p, p_sibling); 1808 break; 1809 } 1810 p = p->p_pptr; 1811 } 1812 } 1813 done: 1814 sx_sunlock(&proctree_lock); 1815 } 1816 1817 /* 1818 * The 'hook' invoked from the kernel proper 1819 */ 1820 1821 1822 #ifdef HWPMC_DEBUG 1823 const char *pmc_hooknames[] = { 1824 /* these strings correspond to PMC_FN_* in <sys/pmckern.h> */ 1825 "", 1826 "EXEC", 1827 "CSW-IN", 1828 "CSW-OUT", 1829 "SAMPLE", 1830 "UNUSED1", 1831 "UNUSED2", 1832 "MMAP", 1833 "MUNMAP", 1834 "CALLCHAIN-NMI", 1835 "CALLCHAIN-SOFT", 1836 "SOFTSAMPLING" 1837 }; 1838 #endif 1839 1840 static int 1841 pmc_hook_handler(struct thread *td, int function, void *arg) 1842 { 1843 1844 PMCDBG4(MOD,PMH,1, "hook td=%p func=%d \"%s\" arg=%p", td, function, 1845 pmc_hooknames[function], arg); 1846 1847 switch (function) 1848 { 1849 1850 /* 1851 * Process exec() 1852 */ 1853 1854 case PMC_FN_PROCESS_EXEC: 1855 { 1856 char *fullpath, *freepath; 1857 unsigned int ri; 1858 int is_using_hwpmcs; 1859 struct pmc *pm; 1860 struct proc *p; 1861 struct pmc_owner *po; 1862 struct pmc_process *pp; 1863 struct pmckern_procexec *pk; 1864 1865 sx_assert(&pmc_sx, SX_XLOCKED); 1866 1867 p = td->td_proc; 1868 pmc_getfilename(p->p_textvp, &fullpath, &freepath); 1869 1870 pk = (struct pmckern_procexec *) arg; 1871 1872 /* Inform owners of SS mode PMCs of the exec event. */ 1873 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1874 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1875 pmclog_process_procexec(po, PMC_ID_INVALID, 1876 p->p_pid, pk->pm_entryaddr, fullpath); 1877 1878 PROC_LOCK(p); 1879 is_using_hwpmcs = p->p_flag & P_HWPMC; 1880 PROC_UNLOCK(p); 1881 1882 if (!is_using_hwpmcs) { 1883 if (freepath) 1884 free(freepath, M_TEMP); 1885 break; 1886 } 1887 1888 /* 1889 * PMCs are not inherited across an exec(): remove any 1890 * PMCs that this process is the owner of. 1891 */ 1892 1893 if ((po = pmc_find_owner_descriptor(p)) != NULL) { 1894 pmc_remove_owner(po); 1895 pmc_destroy_owner_descriptor(po); 1896 } 1897 1898 /* 1899 * If the process being exec'ed is not the target of any 1900 * PMC, we are done. 1901 */ 1902 if ((pp = pmc_find_process_descriptor(p, 0)) == NULL) { 1903 if (freepath) 1904 free(freepath, M_TEMP); 1905 break; 1906 } 1907 1908 /* 1909 * Log the exec event to all monitoring owners. Skip 1910 * owners who have already received the event because 1911 * they had system sampling PMCs active. 1912 */ 1913 for (ri = 0; ri < md->pmd_npmc; ri++) 1914 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) { 1915 po = pm->pm_owner; 1916 if (po->po_sscount == 0 && 1917 po->po_flags & PMC_PO_OWNS_LOGFILE) 1918 pmclog_process_procexec(po, pm->pm_id, 1919 p->p_pid, pk->pm_entryaddr, 1920 fullpath); 1921 } 1922 1923 if (freepath) 1924 free(freepath, M_TEMP); 1925 1926 1927 PMCDBG4(PRC,EXC,1, "exec proc=%p (%d, %s) cred-changed=%d", 1928 p, p->p_pid, p->p_comm, pk->pm_credentialschanged); 1929 1930 if (pk->pm_credentialschanged == 0) /* no change */ 1931 break; 1932 1933 /* 1934 * If the newly exec()'ed process has a different credential 1935 * than before, allow it to be the target of a PMC only if 1936 * the PMC's owner has sufficient privilege. 1937 */ 1938 1939 for (ri = 0; ri < md->pmd_npmc; ri++) 1940 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) 1941 if (pmc_can_attach(pm, td->td_proc) != 0) 1942 pmc_detach_one_process(td->td_proc, 1943 pm, PMC_FLAG_NONE); 1944 1945 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= (int) md->pmd_npmc, 1946 ("[pmc,%d] Illegal ref count %d on pp %p", __LINE__, 1947 pp->pp_refcnt, pp)); 1948 1949 /* 1950 * If this process is no longer the target of any 1951 * PMCs, we can remove the process entry and free 1952 * up space. 1953 */ 1954 1955 if (pp->pp_refcnt == 0) { 1956 pmc_remove_process_descriptor(pp); 1957 free(pp, M_PMC); 1958 break; 1959 } 1960 1961 } 1962 break; 1963 1964 case PMC_FN_CSW_IN: 1965 pmc_process_csw_in(td); 1966 break; 1967 1968 case PMC_FN_CSW_OUT: 1969 pmc_process_csw_out(td); 1970 break; 1971 1972 /* 1973 * Process accumulated PC samples. 1974 * 1975 * This function is expected to be called by hardclock() for 1976 * each CPU that has accumulated PC samples. 1977 * 1978 * This function is to be executed on the CPU whose samples 1979 * are being processed. 1980 */ 1981 case PMC_FN_DO_SAMPLES: 1982 1983 /* 1984 * Clear the cpu specific bit in the CPU mask before 1985 * do the rest of the processing. If the NMI handler 1986 * gets invoked after the "atomic_clear_int()" call 1987 * below but before "pmc_process_samples()" gets 1988 * around to processing the interrupt, then we will 1989 * come back here at the next hardclock() tick (and 1990 * may find nothing to do if "pmc_process_samples()" 1991 * had already processed the interrupt). We don't 1992 * lose the interrupt sample. 1993 */ 1994 CPU_CLR_ATOMIC(PCPU_GET(cpuid), &pmc_cpumask); 1995 pmc_process_samples(PCPU_GET(cpuid), PMC_HR); 1996 pmc_process_samples(PCPU_GET(cpuid), PMC_SR); 1997 break; 1998 1999 case PMC_FN_MMAP: 2000 sx_assert(&pmc_sx, SX_LOCKED); 2001 pmc_process_mmap(td, (struct pmckern_map_in *) arg); 2002 break; 2003 2004 case PMC_FN_MUNMAP: 2005 sx_assert(&pmc_sx, SX_LOCKED); 2006 pmc_process_munmap(td, (struct pmckern_map_out *) arg); 2007 break; 2008 2009 case PMC_FN_USER_CALLCHAIN: 2010 /* 2011 * Record a call chain. 2012 */ 2013 KASSERT(td == curthread, ("[pmc,%d] td != curthread", 2014 __LINE__)); 2015 2016 pmc_capture_user_callchain(PCPU_GET(cpuid), PMC_HR, 2017 (struct trapframe *) arg); 2018 td->td_pflags &= ~TDP_CALLCHAIN; 2019 break; 2020 2021 case PMC_FN_USER_CALLCHAIN_SOFT: 2022 /* 2023 * Record a call chain. 2024 */ 2025 KASSERT(td == curthread, ("[pmc,%d] td != curthread", 2026 __LINE__)); 2027 pmc_capture_user_callchain(PCPU_GET(cpuid), PMC_SR, 2028 (struct trapframe *) arg); 2029 td->td_pflags &= ~TDP_CALLCHAIN; 2030 break; 2031 2032 case PMC_FN_SOFT_SAMPLING: 2033 /* 2034 * Call soft PMC sampling intr. 2035 */ 2036 pmc_soft_intr((struct pmckern_soft *) arg); 2037 break; 2038 2039 default: 2040 #ifdef HWPMC_DEBUG 2041 KASSERT(0, ("[pmc,%d] unknown hook %d\n", __LINE__, function)); 2042 #endif 2043 break; 2044 2045 } 2046 2047 return 0; 2048 } 2049 2050 /* 2051 * allocate a 'struct pmc_owner' descriptor in the owner hash table. 2052 */ 2053 2054 static struct pmc_owner * 2055 pmc_allocate_owner_descriptor(struct proc *p) 2056 { 2057 uint32_t hindex; 2058 struct pmc_owner *po; 2059 struct pmc_ownerhash *poh; 2060 2061 hindex = PMC_HASH_PTR(p, pmc_ownerhashmask); 2062 poh = &pmc_ownerhash[hindex]; 2063 2064 /* allocate space for N pointers and one descriptor struct */ 2065 po = malloc(sizeof(struct pmc_owner), M_PMC, M_WAITOK|M_ZERO); 2066 po->po_owner = p; 2067 LIST_INSERT_HEAD(poh, po, po_next); /* insert into hash table */ 2068 2069 TAILQ_INIT(&po->po_logbuffers); 2070 mtx_init(&po->po_mtx, "pmc-owner-mtx", "pmc-per-proc", MTX_SPIN); 2071 2072 PMCDBG4(OWN,ALL,1, "allocate-owner proc=%p (%d, %s) pmc-owner=%p", 2073 p, p->p_pid, p->p_comm, po); 2074 2075 return po; 2076 } 2077 2078 static void 2079 pmc_destroy_owner_descriptor(struct pmc_owner *po) 2080 { 2081 2082 PMCDBG4(OWN,REL,1, "destroy-owner po=%p proc=%p (%d, %s)", 2083 po, po->po_owner, po->po_owner->p_pid, po->po_owner->p_comm); 2084 2085 mtx_destroy(&po->po_mtx); 2086 free(po, M_PMC); 2087 } 2088 2089 /* 2090 * find the descriptor corresponding to process 'p', adding or removing it 2091 * as specified by 'mode'. 2092 */ 2093 2094 static struct pmc_process * 2095 pmc_find_process_descriptor(struct proc *p, uint32_t mode) 2096 { 2097 uint32_t hindex; 2098 struct pmc_process *pp, *ppnew; 2099 struct pmc_processhash *pph; 2100 2101 hindex = PMC_HASH_PTR(p, pmc_processhashmask); 2102 pph = &pmc_processhash[hindex]; 2103 2104 ppnew = NULL; 2105 2106 /* 2107 * Pre-allocate memory in the FIND_ALLOCATE case since we 2108 * cannot call malloc(9) once we hold a spin lock. 2109 */ 2110 if (mode & PMC_FLAG_ALLOCATE) 2111 ppnew = malloc(sizeof(struct pmc_process) + md->pmd_npmc * 2112 sizeof(struct pmc_targetstate), M_PMC, M_WAITOK|M_ZERO); 2113 2114 mtx_lock_spin(&pmc_processhash_mtx); 2115 LIST_FOREACH(pp, pph, pp_next) 2116 if (pp->pp_proc == p) 2117 break; 2118 2119 if ((mode & PMC_FLAG_REMOVE) && pp != NULL) 2120 LIST_REMOVE(pp, pp_next); 2121 2122 if ((mode & PMC_FLAG_ALLOCATE) && pp == NULL && 2123 ppnew != NULL) { 2124 ppnew->pp_proc = p; 2125 LIST_INSERT_HEAD(pph, ppnew, pp_next); 2126 pp = ppnew; 2127 ppnew = NULL; 2128 } 2129 mtx_unlock_spin(&pmc_processhash_mtx); 2130 2131 if (pp != NULL && ppnew != NULL) 2132 free(ppnew, M_PMC); 2133 2134 return pp; 2135 } 2136 2137 /* 2138 * remove a process descriptor from the process hash table. 2139 */ 2140 2141 static void 2142 pmc_remove_process_descriptor(struct pmc_process *pp) 2143 { 2144 KASSERT(pp->pp_refcnt == 0, 2145 ("[pmc,%d] Removing process descriptor %p with count %d", 2146 __LINE__, pp, pp->pp_refcnt)); 2147 2148 mtx_lock_spin(&pmc_processhash_mtx); 2149 LIST_REMOVE(pp, pp_next); 2150 mtx_unlock_spin(&pmc_processhash_mtx); 2151 } 2152 2153 2154 /* 2155 * find an owner descriptor corresponding to proc 'p' 2156 */ 2157 2158 static struct pmc_owner * 2159 pmc_find_owner_descriptor(struct proc *p) 2160 { 2161 uint32_t hindex; 2162 struct pmc_owner *po; 2163 struct pmc_ownerhash *poh; 2164 2165 hindex = PMC_HASH_PTR(p, pmc_ownerhashmask); 2166 poh = &pmc_ownerhash[hindex]; 2167 2168 po = NULL; 2169 LIST_FOREACH(po, poh, po_next) 2170 if (po->po_owner == p) 2171 break; 2172 2173 PMCDBG5(OWN,FND,1, "find-owner proc=%p (%d, %s) hindex=0x%x -> " 2174 "pmc-owner=%p", p, p->p_pid, p->p_comm, hindex, po); 2175 2176 return po; 2177 } 2178 2179 /* 2180 * pmc_allocate_pmc_descriptor 2181 * 2182 * Allocate a pmc descriptor and initialize its 2183 * fields. 2184 */ 2185 2186 static struct pmc * 2187 pmc_allocate_pmc_descriptor(void) 2188 { 2189 struct pmc *pmc; 2190 2191 pmc = malloc(sizeof(struct pmc), M_PMC, M_WAITOK|M_ZERO); 2192 2193 PMCDBG1(PMC,ALL,1, "allocate-pmc -> pmc=%p", pmc); 2194 2195 return pmc; 2196 } 2197 2198 /* 2199 * Destroy a pmc descriptor. 2200 */ 2201 2202 static void 2203 pmc_destroy_pmc_descriptor(struct pmc *pm) 2204 { 2205 2206 KASSERT(pm->pm_state == PMC_STATE_DELETED || 2207 pm->pm_state == PMC_STATE_FREE, 2208 ("[pmc,%d] destroying non-deleted PMC", __LINE__)); 2209 KASSERT(LIST_EMPTY(&pm->pm_targets), 2210 ("[pmc,%d] destroying pmc with targets", __LINE__)); 2211 KASSERT(pm->pm_owner == NULL, 2212 ("[pmc,%d] destroying pmc attached to an owner", __LINE__)); 2213 KASSERT(pm->pm_runcount == 0, 2214 ("[pmc,%d] pmc has non-zero run count %d", __LINE__, 2215 pm->pm_runcount)); 2216 2217 free(pm, M_PMC); 2218 } 2219 2220 static void 2221 pmc_wait_for_pmc_idle(struct pmc *pm) 2222 { 2223 #ifdef HWPMC_DEBUG 2224 volatile int maxloop; 2225 2226 maxloop = 100 * pmc_cpu_max(); 2227 #endif 2228 /* 2229 * Loop (with a forced context switch) till the PMC's runcount 2230 * comes down to zero. 2231 */ 2232 while (atomic_load_acq_32(&pm->pm_runcount) > 0) { 2233 #ifdef HWPMC_DEBUG 2234 maxloop--; 2235 KASSERT(maxloop > 0, 2236 ("[pmc,%d] (ri%d, rc%d) waiting too long for " 2237 "pmc to be free", __LINE__, 2238 PMC_TO_ROWINDEX(pm), pm->pm_runcount)); 2239 #endif 2240 pmc_force_context_switch(); 2241 } 2242 } 2243 2244 /* 2245 * This function does the following things: 2246 * 2247 * - detaches the PMC from hardware 2248 * - unlinks all target threads that were attached to it 2249 * - removes the PMC from its owner's list 2250 * - destroys the PMC private mutex 2251 * 2252 * Once this function completes, the given pmc pointer can be freed by 2253 * calling pmc_destroy_pmc_descriptor(). 2254 */ 2255 2256 static void 2257 pmc_release_pmc_descriptor(struct pmc *pm) 2258 { 2259 enum pmc_mode mode; 2260 struct pmc_hw *phw; 2261 u_int adjri, ri, cpu; 2262 struct pmc_owner *po; 2263 struct pmc_binding pb; 2264 struct pmc_process *pp; 2265 struct pmc_classdep *pcd; 2266 struct pmc_target *ptgt, *tmp; 2267 2268 sx_assert(&pmc_sx, SX_XLOCKED); 2269 2270 KASSERT(pm, ("[pmc,%d] null pmc", __LINE__)); 2271 2272 ri = PMC_TO_ROWINDEX(pm); 2273 pcd = pmc_ri_to_classdep(md, ri, &adjri); 2274 mode = PMC_TO_MODE(pm); 2275 2276 PMCDBG3(PMC,REL,1, "release-pmc pmc=%p ri=%d mode=%d", pm, ri, 2277 mode); 2278 2279 /* 2280 * First, we take the PMC off hardware. 2281 */ 2282 cpu = 0; 2283 if (PMC_IS_SYSTEM_MODE(mode)) { 2284 2285 /* 2286 * A system mode PMC runs on a specific CPU. Switch 2287 * to this CPU and turn hardware off. 2288 */ 2289 pmc_save_cpu_binding(&pb); 2290 2291 cpu = PMC_TO_CPU(pm); 2292 2293 pmc_select_cpu(cpu); 2294 2295 /* switch off non-stalled CPUs */ 2296 CPU_CLR_ATOMIC(cpu, &pm->pm_cpustate); 2297 if (pm->pm_state == PMC_STATE_RUNNING && 2298 !CPU_ISSET(cpu, &pm->pm_stalled)) { 2299 2300 phw = pmc_pcpu[cpu]->pc_hwpmcs[ri]; 2301 2302 KASSERT(phw->phw_pmc == pm, 2303 ("[pmc, %d] pmc ptr ri(%d) hw(%p) pm(%p)", 2304 __LINE__, ri, phw->phw_pmc, pm)); 2305 PMCDBG2(PMC,REL,2, "stopping cpu=%d ri=%d", cpu, ri); 2306 2307 critical_enter(); 2308 pcd->pcd_stop_pmc(cpu, adjri); 2309 critical_exit(); 2310 } 2311 2312 PMCDBG2(PMC,REL,2, "decfg cpu=%d ri=%d", cpu, ri); 2313 2314 critical_enter(); 2315 pcd->pcd_config_pmc(cpu, adjri, NULL); 2316 critical_exit(); 2317 2318 /* adjust the global and process count of SS mode PMCs */ 2319 if (mode == PMC_MODE_SS && pm->pm_state == PMC_STATE_RUNNING) { 2320 po = pm->pm_owner; 2321 po->po_sscount--; 2322 if (po->po_sscount == 0) { 2323 atomic_subtract_rel_int(&pmc_ss_count, 1); 2324 LIST_REMOVE(po, po_ssnext); 2325 } 2326 } 2327 2328 pm->pm_state = PMC_STATE_DELETED; 2329 2330 pmc_restore_cpu_binding(&pb); 2331 2332 /* 2333 * We could have references to this PMC structure in 2334 * the per-cpu sample queues. Wait for the queue to 2335 * drain. 2336 */ 2337 pmc_wait_for_pmc_idle(pm); 2338 2339 } else if (PMC_IS_VIRTUAL_MODE(mode)) { 2340 2341 /* 2342 * A virtual PMC could be running on multiple CPUs at 2343 * a given instant. 2344 * 2345 * By marking its state as DELETED, we ensure that 2346 * this PMC is never further scheduled on hardware. 2347 * 2348 * Then we wait till all CPUs are done with this PMC. 2349 */ 2350 pm->pm_state = PMC_STATE_DELETED; 2351 2352 2353 /* Wait for the PMCs runcount to come to zero. */ 2354 pmc_wait_for_pmc_idle(pm); 2355 2356 /* 2357 * At this point the PMC is off all CPUs and cannot be 2358 * freshly scheduled onto a CPU. It is now safe to 2359 * unlink all targets from this PMC. If a 2360 * process-record's refcount falls to zero, we remove 2361 * it from the hash table. The module-wide SX lock 2362 * protects us from races. 2363 */ 2364 LIST_FOREACH_SAFE(ptgt, &pm->pm_targets, pt_next, tmp) { 2365 pp = ptgt->pt_process; 2366 pmc_unlink_target_process(pm, pp); /* frees 'ptgt' */ 2367 2368 PMCDBG1(PMC,REL,3, "pp->refcnt=%d", pp->pp_refcnt); 2369 2370 /* 2371 * If the target process record shows that no 2372 * PMCs are attached to it, reclaim its space. 2373 */ 2374 2375 if (pp->pp_refcnt == 0) { 2376 pmc_remove_process_descriptor(pp); 2377 free(pp, M_PMC); 2378 } 2379 } 2380 2381 cpu = curthread->td_oncpu; /* setup cpu for pmd_release() */ 2382 2383 } 2384 2385 /* 2386 * Release any MD resources 2387 */ 2388 (void) pcd->pcd_release_pmc(cpu, adjri, pm); 2389 2390 /* 2391 * Update row disposition 2392 */ 2393 2394 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) 2395 PMC_UNMARK_ROW_STANDALONE(ri); 2396 else 2397 PMC_UNMARK_ROW_THREAD(ri); 2398 2399 /* unlink from the owner's list */ 2400 if (pm->pm_owner) { 2401 LIST_REMOVE(pm, pm_next); 2402 pm->pm_owner = NULL; 2403 } 2404 } 2405 2406 /* 2407 * Register an owner and a pmc. 2408 */ 2409 2410 static int 2411 pmc_register_owner(struct proc *p, struct pmc *pmc) 2412 { 2413 struct pmc_owner *po; 2414 2415 sx_assert(&pmc_sx, SX_XLOCKED); 2416 2417 if ((po = pmc_find_owner_descriptor(p)) == NULL) 2418 if ((po = pmc_allocate_owner_descriptor(p)) == NULL) 2419 return ENOMEM; 2420 2421 KASSERT(pmc->pm_owner == NULL, 2422 ("[pmc,%d] attempting to own an initialized PMC", __LINE__)); 2423 pmc->pm_owner = po; 2424 2425 LIST_INSERT_HEAD(&po->po_pmcs, pmc, pm_next); 2426 2427 PROC_LOCK(p); 2428 p->p_flag |= P_HWPMC; 2429 PROC_UNLOCK(p); 2430 2431 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 2432 pmclog_process_pmcallocate(pmc); 2433 2434 PMCDBG2(PMC,REG,1, "register-owner pmc-owner=%p pmc=%p", 2435 po, pmc); 2436 2437 return 0; 2438 } 2439 2440 /* 2441 * Return the current row disposition: 2442 * == 0 => FREE 2443 * > 0 => PROCESS MODE 2444 * < 0 => SYSTEM MODE 2445 */ 2446 2447 int 2448 pmc_getrowdisp(int ri) 2449 { 2450 return pmc_pmcdisp[ri]; 2451 } 2452 2453 /* 2454 * Check if a PMC at row index 'ri' can be allocated to the current 2455 * process. 2456 * 2457 * Allocation can fail if: 2458 * - the current process is already being profiled by a PMC at index 'ri', 2459 * attached to it via OP_PMCATTACH. 2460 * - the current process has already allocated a PMC at index 'ri' 2461 * via OP_ALLOCATE. 2462 */ 2463 2464 static int 2465 pmc_can_allocate_rowindex(struct proc *p, unsigned int ri, int cpu) 2466 { 2467 enum pmc_mode mode; 2468 struct pmc *pm; 2469 struct pmc_owner *po; 2470 struct pmc_process *pp; 2471 2472 PMCDBG5(PMC,ALR,1, "can-allocate-rowindex proc=%p (%d, %s) ri=%d " 2473 "cpu=%d", p, p->p_pid, p->p_comm, ri, cpu); 2474 2475 /* 2476 * We shouldn't have already allocated a process-mode PMC at 2477 * row index 'ri'. 2478 * 2479 * We shouldn't have allocated a system-wide PMC on the same 2480 * CPU and same RI. 2481 */ 2482 if ((po = pmc_find_owner_descriptor(p)) != NULL) 2483 LIST_FOREACH(pm, &po->po_pmcs, pm_next) { 2484 if (PMC_TO_ROWINDEX(pm) == ri) { 2485 mode = PMC_TO_MODE(pm); 2486 if (PMC_IS_VIRTUAL_MODE(mode)) 2487 return EEXIST; 2488 if (PMC_IS_SYSTEM_MODE(mode) && 2489 (int) PMC_TO_CPU(pm) == cpu) 2490 return EEXIST; 2491 } 2492 } 2493 2494 /* 2495 * We also shouldn't be the target of any PMC at this index 2496 * since otherwise a PMC_ATTACH to ourselves will fail. 2497 */ 2498 if ((pp = pmc_find_process_descriptor(p, 0)) != NULL) 2499 if (pp->pp_pmcs[ri].pp_pmc) 2500 return EEXIST; 2501 2502 PMCDBG4(PMC,ALR,2, "can-allocate-rowindex proc=%p (%d, %s) ri=%d ok", 2503 p, p->p_pid, p->p_comm, ri); 2504 2505 return 0; 2506 } 2507 2508 /* 2509 * Check if a given PMC at row index 'ri' can be currently used in 2510 * mode 'mode'. 2511 */ 2512 2513 static int 2514 pmc_can_allocate_row(int ri, enum pmc_mode mode) 2515 { 2516 enum pmc_disp disp; 2517 2518 sx_assert(&pmc_sx, SX_XLOCKED); 2519 2520 PMCDBG2(PMC,ALR,1, "can-allocate-row ri=%d mode=%d", ri, mode); 2521 2522 if (PMC_IS_SYSTEM_MODE(mode)) 2523 disp = PMC_DISP_STANDALONE; 2524 else 2525 disp = PMC_DISP_THREAD; 2526 2527 /* 2528 * check disposition for PMC row 'ri': 2529 * 2530 * Expected disposition Row-disposition Result 2531 * 2532 * STANDALONE STANDALONE or FREE proceed 2533 * STANDALONE THREAD fail 2534 * THREAD THREAD or FREE proceed 2535 * THREAD STANDALONE fail 2536 */ 2537 2538 if (!PMC_ROW_DISP_IS_FREE(ri) && 2539 !(disp == PMC_DISP_THREAD && PMC_ROW_DISP_IS_THREAD(ri)) && 2540 !(disp == PMC_DISP_STANDALONE && PMC_ROW_DISP_IS_STANDALONE(ri))) 2541 return EBUSY; 2542 2543 /* 2544 * All OK 2545 */ 2546 2547 PMCDBG2(PMC,ALR,2, "can-allocate-row ri=%d mode=%d ok", ri, mode); 2548 2549 return 0; 2550 2551 } 2552 2553 /* 2554 * Find a PMC descriptor with user handle 'pmcid' for thread 'td'. 2555 */ 2556 2557 static struct pmc * 2558 pmc_find_pmc_descriptor_in_process(struct pmc_owner *po, pmc_id_t pmcid) 2559 { 2560 struct pmc *pm; 2561 2562 KASSERT(PMC_ID_TO_ROWINDEX(pmcid) < md->pmd_npmc, 2563 ("[pmc,%d] Illegal pmc index %d (max %d)", __LINE__, 2564 PMC_ID_TO_ROWINDEX(pmcid), md->pmd_npmc)); 2565 2566 LIST_FOREACH(pm, &po->po_pmcs, pm_next) 2567 if (pm->pm_id == pmcid) 2568 return pm; 2569 2570 return NULL; 2571 } 2572 2573 static int 2574 pmc_find_pmc(pmc_id_t pmcid, struct pmc **pmc) 2575 { 2576 2577 struct pmc *pm, *opm; 2578 struct pmc_owner *po; 2579 struct pmc_process *pp; 2580 2581 PMCDBG1(PMC,FND,1, "find-pmc id=%d", pmcid); 2582 if (PMC_ID_TO_ROWINDEX(pmcid) >= md->pmd_npmc) 2583 return (EINVAL); 2584 2585 if ((po = pmc_find_owner_descriptor(curthread->td_proc)) == NULL) { 2586 /* 2587 * In case of PMC_F_DESCENDANTS child processes we will not find 2588 * the current process in the owners hash list. Find the owner 2589 * process first and from there lookup the po. 2590 */ 2591 if ((pp = pmc_find_process_descriptor(curthread->td_proc, 2592 PMC_FLAG_NONE)) == NULL) { 2593 return ESRCH; 2594 } else { 2595 opm = pp->pp_pmcs[PMC_ID_TO_ROWINDEX(pmcid)].pp_pmc; 2596 if (opm == NULL) 2597 return ESRCH; 2598 if ((opm->pm_flags & (PMC_F_ATTACHED_TO_OWNER| 2599 PMC_F_DESCENDANTS)) != (PMC_F_ATTACHED_TO_OWNER| 2600 PMC_F_DESCENDANTS)) 2601 return ESRCH; 2602 po = opm->pm_owner; 2603 } 2604 } 2605 2606 if ((pm = pmc_find_pmc_descriptor_in_process(po, pmcid)) == NULL) 2607 return EINVAL; 2608 2609 PMCDBG2(PMC,FND,2, "find-pmc id=%d -> pmc=%p", pmcid, pm); 2610 2611 *pmc = pm; 2612 return 0; 2613 } 2614 2615 /* 2616 * Start a PMC. 2617 */ 2618 2619 static int 2620 pmc_start(struct pmc *pm) 2621 { 2622 enum pmc_mode mode; 2623 struct pmc_owner *po; 2624 struct pmc_binding pb; 2625 struct pmc_classdep *pcd; 2626 int adjri, error, cpu, ri; 2627 2628 KASSERT(pm != NULL, 2629 ("[pmc,%d] null pm", __LINE__)); 2630 2631 mode = PMC_TO_MODE(pm); 2632 ri = PMC_TO_ROWINDEX(pm); 2633 pcd = pmc_ri_to_classdep(md, ri, &adjri); 2634 2635 error = 0; 2636 2637 PMCDBG3(PMC,OPS,1, "start pmc=%p mode=%d ri=%d", pm, mode, ri); 2638 2639 po = pm->pm_owner; 2640 2641 /* 2642 * Disallow PMCSTART if a logfile is required but has not been 2643 * configured yet. 2644 */ 2645 if ((pm->pm_flags & PMC_F_NEEDS_LOGFILE) && 2646 (po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) 2647 return (EDOOFUS); /* programming error */ 2648 2649 /* 2650 * If this is a sampling mode PMC, log mapping information for 2651 * the kernel modules that are currently loaded. 2652 */ 2653 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 2654 pmc_log_kernel_mappings(pm); 2655 2656 if (PMC_IS_VIRTUAL_MODE(mode)) { 2657 2658 /* 2659 * If a PMCATTACH has never been done on this PMC, 2660 * attach it to its owner process. 2661 */ 2662 2663 if (LIST_EMPTY(&pm->pm_targets)) 2664 error = (pm->pm_flags & PMC_F_ATTACH_DONE) ? ESRCH : 2665 pmc_attach_process(po->po_owner, pm); 2666 2667 /* 2668 * If the PMC is attached to its owner, then force a context 2669 * switch to ensure that the MD state gets set correctly. 2670 */ 2671 2672 if (error == 0) { 2673 pm->pm_state = PMC_STATE_RUNNING; 2674 if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) 2675 pmc_force_context_switch(); 2676 } 2677 2678 return (error); 2679 } 2680 2681 2682 /* 2683 * A system-wide PMC. 2684 * 2685 * Add the owner to the global list if this is a system-wide 2686 * sampling PMC. 2687 */ 2688 2689 if (mode == PMC_MODE_SS) { 2690 if (po->po_sscount == 0) { 2691 LIST_INSERT_HEAD(&pmc_ss_owners, po, po_ssnext); 2692 atomic_add_rel_int(&pmc_ss_count, 1); 2693 PMCDBG1(PMC,OPS,1, "po=%p in global list", po); 2694 } 2695 po->po_sscount++; 2696 2697 /* 2698 * Log mapping information for all existing processes in the 2699 * system. Subsequent mappings are logged as they happen; 2700 * see pmc_process_mmap(). 2701 */ 2702 if (po->po_logprocmaps == 0) { 2703 pmc_log_all_process_mappings(po); 2704 po->po_logprocmaps = 1; 2705 } 2706 } 2707 2708 /* 2709 * Move to the CPU associated with this 2710 * PMC, and start the hardware. 2711 */ 2712 2713 pmc_save_cpu_binding(&pb); 2714 2715 cpu = PMC_TO_CPU(pm); 2716 2717 if (!pmc_cpu_is_active(cpu)) 2718 return (ENXIO); 2719 2720 pmc_select_cpu(cpu); 2721 2722 /* 2723 * global PMCs are configured at allocation time 2724 * so write out the initial value and start the PMC. 2725 */ 2726 2727 pm->pm_state = PMC_STATE_RUNNING; 2728 2729 critical_enter(); 2730 if ((error = pcd->pcd_write_pmc(cpu, adjri, 2731 PMC_IS_SAMPLING_MODE(mode) ? 2732 pm->pm_sc.pm_reloadcount : 2733 pm->pm_sc.pm_initial)) == 0) { 2734 /* If a sampling mode PMC, reset stalled state. */ 2735 if (PMC_IS_SAMPLING_MODE(mode)) 2736 CPU_CLR_ATOMIC(cpu, &pm->pm_stalled); 2737 2738 /* Indicate that we desire this to run. Start it. */ 2739 CPU_SET_ATOMIC(cpu, &pm->pm_cpustate); 2740 error = pcd->pcd_start_pmc(cpu, adjri); 2741 } 2742 critical_exit(); 2743 2744 pmc_restore_cpu_binding(&pb); 2745 2746 return (error); 2747 } 2748 2749 /* 2750 * Stop a PMC. 2751 */ 2752 2753 static int 2754 pmc_stop(struct pmc *pm) 2755 { 2756 struct pmc_owner *po; 2757 struct pmc_binding pb; 2758 struct pmc_classdep *pcd; 2759 int adjri, cpu, error, ri; 2760 2761 KASSERT(pm != NULL, ("[pmc,%d] null pmc", __LINE__)); 2762 2763 PMCDBG3(PMC,OPS,1, "stop pmc=%p mode=%d ri=%d", pm, 2764 PMC_TO_MODE(pm), PMC_TO_ROWINDEX(pm)); 2765 2766 pm->pm_state = PMC_STATE_STOPPED; 2767 2768 /* 2769 * If the PMC is a virtual mode one, changing the state to 2770 * non-RUNNING is enough to ensure that the PMC never gets 2771 * scheduled. 2772 * 2773 * If this PMC is current running on a CPU, then it will 2774 * handled correctly at the time its target process is context 2775 * switched out. 2776 */ 2777 2778 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) 2779 return 0; 2780 2781 /* 2782 * A system-mode PMC. Move to the CPU associated with 2783 * this PMC, and stop the hardware. We update the 2784 * 'initial count' so that a subsequent PMCSTART will 2785 * resume counting from the current hardware count. 2786 */ 2787 2788 pmc_save_cpu_binding(&pb); 2789 2790 cpu = PMC_TO_CPU(pm); 2791 2792 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 2793 ("[pmc,%d] illegal cpu=%d", __LINE__, cpu)); 2794 2795 if (!pmc_cpu_is_active(cpu)) 2796 return ENXIO; 2797 2798 pmc_select_cpu(cpu); 2799 2800 ri = PMC_TO_ROWINDEX(pm); 2801 pcd = pmc_ri_to_classdep(md, ri, &adjri); 2802 2803 CPU_CLR_ATOMIC(cpu, &pm->pm_cpustate); 2804 critical_enter(); 2805 if ((error = pcd->pcd_stop_pmc(cpu, adjri)) == 0) 2806 error = pcd->pcd_read_pmc(cpu, adjri, &pm->pm_sc.pm_initial); 2807 critical_exit(); 2808 2809 pmc_restore_cpu_binding(&pb); 2810 2811 po = pm->pm_owner; 2812 2813 /* remove this owner from the global list of SS PMC owners */ 2814 if (PMC_TO_MODE(pm) == PMC_MODE_SS) { 2815 po->po_sscount--; 2816 if (po->po_sscount == 0) { 2817 atomic_subtract_rel_int(&pmc_ss_count, 1); 2818 LIST_REMOVE(po, po_ssnext); 2819 PMCDBG1(PMC,OPS,2,"po=%p removed from global list", po); 2820 } 2821 } 2822 2823 return (error); 2824 } 2825 2826 2827 #ifdef HWPMC_DEBUG 2828 static const char *pmc_op_to_name[] = { 2829 #undef __PMC_OP 2830 #define __PMC_OP(N, D) #N , 2831 __PMC_OPS() 2832 NULL 2833 }; 2834 #endif 2835 2836 /* 2837 * The syscall interface 2838 */ 2839 2840 #define PMC_GET_SX_XLOCK(...) do { \ 2841 sx_xlock(&pmc_sx); \ 2842 if (pmc_hook == NULL) { \ 2843 sx_xunlock(&pmc_sx); \ 2844 return __VA_ARGS__; \ 2845 } \ 2846 } while (0) 2847 2848 #define PMC_DOWNGRADE_SX() do { \ 2849 sx_downgrade(&pmc_sx); \ 2850 is_sx_downgraded = 1; \ 2851 } while (0) 2852 2853 static int 2854 pmc_syscall_handler(struct thread *td, void *syscall_args) 2855 { 2856 int error, is_sx_downgraded, op; 2857 struct pmc_syscall_args *c; 2858 void *pmclog_proc_handle; 2859 void *arg; 2860 2861 c = (struct pmc_syscall_args *)syscall_args; 2862 op = c->pmop_code; 2863 arg = c->pmop_data; 2864 if (op == PMC_OP_CONFIGURELOG) { 2865 /* 2866 * We cannot create the logging process inside 2867 * pmclog_configure_log() because there is a LOR 2868 * between pmc_sx and process structure locks. 2869 * Instead, pre-create the process and ignite the loop 2870 * if everything is fine, otherwise direct the process 2871 * to exit. 2872 */ 2873 error = pmclog_proc_create(td, &pmclog_proc_handle); 2874 if (error != 0) 2875 goto done_syscall; 2876 } 2877 2878 PMC_GET_SX_XLOCK(ENOSYS); 2879 is_sx_downgraded = 0; 2880 2881 PMCDBG3(MOD,PMS,1, "syscall op=%d \"%s\" arg=%p", op, 2882 pmc_op_to_name[op], arg); 2883 2884 error = 0; 2885 atomic_add_int(&pmc_stats.pm_syscalls, 1); 2886 2887 switch (op) { 2888 2889 2890 /* 2891 * Configure a log file. 2892 * 2893 * XXX This OP will be reworked. 2894 */ 2895 2896 case PMC_OP_CONFIGURELOG: 2897 { 2898 struct proc *p; 2899 struct pmc *pm; 2900 struct pmc_owner *po; 2901 struct pmc_op_configurelog cl; 2902 2903 if ((error = copyin(arg, &cl, sizeof(cl))) != 0) { 2904 pmclog_proc_ignite(pmclog_proc_handle, NULL); 2905 break; 2906 } 2907 2908 /* mark this process as owning a log file */ 2909 p = td->td_proc; 2910 if ((po = pmc_find_owner_descriptor(p)) == NULL) 2911 if ((po = pmc_allocate_owner_descriptor(p)) == NULL) { 2912 pmclog_proc_ignite(pmclog_proc_handle, NULL); 2913 error = ENOMEM; 2914 break; 2915 } 2916 2917 /* 2918 * If a valid fd was passed in, try to configure that, 2919 * otherwise if 'fd' was less than zero and there was 2920 * a log file configured, flush its buffers and 2921 * de-configure it. 2922 */ 2923 if (cl.pm_logfd >= 0) { 2924 error = pmclog_configure_log(md, po, cl.pm_logfd); 2925 pmclog_proc_ignite(pmclog_proc_handle, error == 0 ? 2926 po : NULL); 2927 } else if (po->po_flags & PMC_PO_OWNS_LOGFILE) { 2928 pmclog_proc_ignite(pmclog_proc_handle, NULL); 2929 pmclog_process_closelog(po); 2930 error = pmclog_close(po); 2931 if (error == 0) { 2932 LIST_FOREACH(pm, &po->po_pmcs, pm_next) 2933 if (pm->pm_flags & PMC_F_NEEDS_LOGFILE && 2934 pm->pm_state == PMC_STATE_RUNNING) 2935 pmc_stop(pm); 2936 error = pmclog_deconfigure_log(po); 2937 } 2938 } else { 2939 pmclog_proc_ignite(pmclog_proc_handle, NULL); 2940 error = EINVAL; 2941 } 2942 } 2943 break; 2944 2945 /* 2946 * Flush a log file. 2947 */ 2948 2949 case PMC_OP_FLUSHLOG: 2950 { 2951 struct pmc_owner *po; 2952 2953 sx_assert(&pmc_sx, SX_XLOCKED); 2954 2955 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 2956 error = EINVAL; 2957 break; 2958 } 2959 2960 error = pmclog_flush(po); 2961 } 2962 break; 2963 2964 /* 2965 * Close a log file. 2966 */ 2967 2968 case PMC_OP_CLOSELOG: 2969 { 2970 struct pmc_owner *po; 2971 2972 sx_assert(&pmc_sx, SX_XLOCKED); 2973 2974 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 2975 error = EINVAL; 2976 break; 2977 } 2978 2979 error = pmclog_close(po); 2980 } 2981 break; 2982 2983 /* 2984 * Retrieve hardware configuration. 2985 */ 2986 2987 case PMC_OP_GETCPUINFO: /* CPU information */ 2988 { 2989 struct pmc_op_getcpuinfo gci; 2990 struct pmc_classinfo *pci; 2991 struct pmc_classdep *pcd; 2992 int cl; 2993 2994 gci.pm_cputype = md->pmd_cputype; 2995 gci.pm_ncpu = pmc_cpu_max(); 2996 gci.pm_npmc = md->pmd_npmc; 2997 gci.pm_nclass = md->pmd_nclass; 2998 pci = gci.pm_classes; 2999 pcd = md->pmd_classdep; 3000 for (cl = 0; cl < md->pmd_nclass; cl++, pci++, pcd++) { 3001 pci->pm_caps = pcd->pcd_caps; 3002 pci->pm_class = pcd->pcd_class; 3003 pci->pm_width = pcd->pcd_width; 3004 pci->pm_num = pcd->pcd_num; 3005 } 3006 error = copyout(&gci, arg, sizeof(gci)); 3007 } 3008 break; 3009 3010 /* 3011 * Retrieve soft events list. 3012 */ 3013 case PMC_OP_GETDYNEVENTINFO: 3014 { 3015 enum pmc_class cl; 3016 enum pmc_event ev; 3017 struct pmc_op_getdyneventinfo *gei; 3018 struct pmc_dyn_event_descr dev; 3019 struct pmc_soft *ps; 3020 uint32_t nevent; 3021 3022 sx_assert(&pmc_sx, SX_LOCKED); 3023 3024 gei = (struct pmc_op_getdyneventinfo *) arg; 3025 3026 if ((error = copyin(&gei->pm_class, &cl, sizeof(cl))) != 0) 3027 break; 3028 3029 /* Only SOFT class is dynamic. */ 3030 if (cl != PMC_CLASS_SOFT) { 3031 error = EINVAL; 3032 break; 3033 } 3034 3035 nevent = 0; 3036 for (ev = PMC_EV_SOFT_FIRST; (int)ev <= PMC_EV_SOFT_LAST; ev++) { 3037 ps = pmc_soft_ev_acquire(ev); 3038 if (ps == NULL) 3039 continue; 3040 bcopy(&ps->ps_ev, &dev, sizeof(dev)); 3041 pmc_soft_ev_release(ps); 3042 3043 error = copyout(&dev, 3044 &gei->pm_events[nevent], 3045 sizeof(struct pmc_dyn_event_descr)); 3046 if (error != 0) 3047 break; 3048 nevent++; 3049 } 3050 if (error != 0) 3051 break; 3052 3053 error = copyout(&nevent, &gei->pm_nevent, 3054 sizeof(nevent)); 3055 } 3056 break; 3057 3058 /* 3059 * Get module statistics 3060 */ 3061 3062 case PMC_OP_GETDRIVERSTATS: 3063 { 3064 struct pmc_op_getdriverstats gms; 3065 3066 bcopy(&pmc_stats, &gms, sizeof(gms)); 3067 error = copyout(&gms, arg, sizeof(gms)); 3068 } 3069 break; 3070 3071 3072 /* 3073 * Retrieve module version number 3074 */ 3075 3076 case PMC_OP_GETMODULEVERSION: 3077 { 3078 uint32_t cv, modv; 3079 3080 /* retrieve the client's idea of the ABI version */ 3081 if ((error = copyin(arg, &cv, sizeof(uint32_t))) != 0) 3082 break; 3083 /* don't service clients newer than our driver */ 3084 modv = PMC_VERSION; 3085 if ((cv & 0xFFFF0000) > (modv & 0xFFFF0000)) { 3086 error = EPROGMISMATCH; 3087 break; 3088 } 3089 error = copyout(&modv, arg, sizeof(int)); 3090 } 3091 break; 3092 3093 3094 /* 3095 * Retrieve the state of all the PMCs on a given 3096 * CPU. 3097 */ 3098 3099 case PMC_OP_GETPMCINFO: 3100 { 3101 int ari; 3102 struct pmc *pm; 3103 size_t pmcinfo_size; 3104 uint32_t cpu, n, npmc; 3105 struct pmc_owner *po; 3106 struct pmc_binding pb; 3107 struct pmc_classdep *pcd; 3108 struct pmc_info *p, *pmcinfo; 3109 struct pmc_op_getpmcinfo *gpi; 3110 3111 PMC_DOWNGRADE_SX(); 3112 3113 gpi = (struct pmc_op_getpmcinfo *) arg; 3114 3115 if ((error = copyin(&gpi->pm_cpu, &cpu, sizeof(cpu))) != 0) 3116 break; 3117 3118 if (cpu >= pmc_cpu_max()) { 3119 error = EINVAL; 3120 break; 3121 } 3122 3123 if (!pmc_cpu_is_active(cpu)) { 3124 error = ENXIO; 3125 break; 3126 } 3127 3128 /* switch to CPU 'cpu' */ 3129 pmc_save_cpu_binding(&pb); 3130 pmc_select_cpu(cpu); 3131 3132 npmc = md->pmd_npmc; 3133 3134 pmcinfo_size = npmc * sizeof(struct pmc_info); 3135 pmcinfo = malloc(pmcinfo_size, M_PMC, M_WAITOK); 3136 3137 p = pmcinfo; 3138 3139 for (n = 0; n < md->pmd_npmc; n++, p++) { 3140 3141 pcd = pmc_ri_to_classdep(md, n, &ari); 3142 3143 KASSERT(pcd != NULL, 3144 ("[pmc,%d] null pcd ri=%d", __LINE__, n)); 3145 3146 if ((error = pcd->pcd_describe(cpu, ari, p, &pm)) != 0) 3147 break; 3148 3149 if (PMC_ROW_DISP_IS_STANDALONE(n)) 3150 p->pm_rowdisp = PMC_DISP_STANDALONE; 3151 else if (PMC_ROW_DISP_IS_THREAD(n)) 3152 p->pm_rowdisp = PMC_DISP_THREAD; 3153 else 3154 p->pm_rowdisp = PMC_DISP_FREE; 3155 3156 p->pm_ownerpid = -1; 3157 3158 if (pm == NULL) /* no PMC associated */ 3159 continue; 3160 3161 po = pm->pm_owner; 3162 3163 KASSERT(po->po_owner != NULL, 3164 ("[pmc,%d] pmc_owner had a null proc pointer", 3165 __LINE__)); 3166 3167 p->pm_ownerpid = po->po_owner->p_pid; 3168 p->pm_mode = PMC_TO_MODE(pm); 3169 p->pm_event = pm->pm_event; 3170 p->pm_flags = pm->pm_flags; 3171 3172 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 3173 p->pm_reloadcount = 3174 pm->pm_sc.pm_reloadcount; 3175 } 3176 3177 pmc_restore_cpu_binding(&pb); 3178 3179 /* now copy out the PMC info collected */ 3180 if (error == 0) 3181 error = copyout(pmcinfo, &gpi->pm_pmcs, pmcinfo_size); 3182 3183 free(pmcinfo, M_PMC); 3184 } 3185 break; 3186 3187 3188 /* 3189 * Set the administrative state of a PMC. I.e. whether 3190 * the PMC is to be used or not. 3191 */ 3192 3193 case PMC_OP_PMCADMIN: 3194 { 3195 int cpu, ri; 3196 enum pmc_state request; 3197 struct pmc_cpu *pc; 3198 struct pmc_hw *phw; 3199 struct pmc_op_pmcadmin pma; 3200 struct pmc_binding pb; 3201 3202 sx_assert(&pmc_sx, SX_XLOCKED); 3203 3204 KASSERT(td == curthread, 3205 ("[pmc,%d] td != curthread", __LINE__)); 3206 3207 error = priv_check(td, PRIV_PMC_MANAGE); 3208 if (error) 3209 break; 3210 3211 if ((error = copyin(arg, &pma, sizeof(pma))) != 0) 3212 break; 3213 3214 cpu = pma.pm_cpu; 3215 3216 if (cpu < 0 || cpu >= (int) pmc_cpu_max()) { 3217 error = EINVAL; 3218 break; 3219 } 3220 3221 if (!pmc_cpu_is_active(cpu)) { 3222 error = ENXIO; 3223 break; 3224 } 3225 3226 request = pma.pm_state; 3227 3228 if (request != PMC_STATE_DISABLED && 3229 request != PMC_STATE_FREE) { 3230 error = EINVAL; 3231 break; 3232 } 3233 3234 ri = pma.pm_pmc; /* pmc id == row index */ 3235 if (ri < 0 || ri >= (int) md->pmd_npmc) { 3236 error = EINVAL; 3237 break; 3238 } 3239 3240 /* 3241 * We can't disable a PMC with a row-index allocated 3242 * for process virtual PMCs. 3243 */ 3244 3245 if (PMC_ROW_DISP_IS_THREAD(ri) && 3246 request == PMC_STATE_DISABLED) { 3247 error = EBUSY; 3248 break; 3249 } 3250 3251 /* 3252 * otherwise, this PMC on this CPU is either free or 3253 * in system-wide mode. 3254 */ 3255 3256 pmc_save_cpu_binding(&pb); 3257 pmc_select_cpu(cpu); 3258 3259 pc = pmc_pcpu[cpu]; 3260 phw = pc->pc_hwpmcs[ri]; 3261 3262 /* 3263 * XXX do we need some kind of 'forced' disable? 3264 */ 3265 3266 if (phw->phw_pmc == NULL) { 3267 if (request == PMC_STATE_DISABLED && 3268 (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED)) { 3269 phw->phw_state &= ~PMC_PHW_FLAG_IS_ENABLED; 3270 PMC_MARK_ROW_STANDALONE(ri); 3271 } else if (request == PMC_STATE_FREE && 3272 (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0) { 3273 phw->phw_state |= PMC_PHW_FLAG_IS_ENABLED; 3274 PMC_UNMARK_ROW_STANDALONE(ri); 3275 } 3276 /* other cases are a no-op */ 3277 } else 3278 error = EBUSY; 3279 3280 pmc_restore_cpu_binding(&pb); 3281 } 3282 break; 3283 3284 3285 /* 3286 * Allocate a PMC. 3287 */ 3288 3289 case PMC_OP_PMCALLOCATE: 3290 { 3291 int adjri, n; 3292 u_int cpu; 3293 uint32_t caps; 3294 struct pmc *pmc; 3295 enum pmc_mode mode; 3296 struct pmc_hw *phw; 3297 struct pmc_binding pb; 3298 struct pmc_classdep *pcd; 3299 struct pmc_op_pmcallocate pa; 3300 3301 if ((error = copyin(arg, &pa, sizeof(pa))) != 0) 3302 break; 3303 3304 caps = pa.pm_caps; 3305 mode = pa.pm_mode; 3306 cpu = pa.pm_cpu; 3307 3308 if ((mode != PMC_MODE_SS && mode != PMC_MODE_SC && 3309 mode != PMC_MODE_TS && mode != PMC_MODE_TC) || 3310 (cpu != (u_int) PMC_CPU_ANY && cpu >= pmc_cpu_max())) { 3311 error = EINVAL; 3312 break; 3313 } 3314 3315 /* 3316 * Virtual PMCs should only ask for a default CPU. 3317 * System mode PMCs need to specify a non-default CPU. 3318 */ 3319 3320 if ((PMC_IS_VIRTUAL_MODE(mode) && cpu != (u_int) PMC_CPU_ANY) || 3321 (PMC_IS_SYSTEM_MODE(mode) && cpu == (u_int) PMC_CPU_ANY)) { 3322 error = EINVAL; 3323 break; 3324 } 3325 3326 /* 3327 * Check that an inactive CPU is not being asked for. 3328 */ 3329 3330 if (PMC_IS_SYSTEM_MODE(mode) && !pmc_cpu_is_active(cpu)) { 3331 error = ENXIO; 3332 break; 3333 } 3334 3335 /* 3336 * Refuse an allocation for a system-wide PMC if this 3337 * process has been jailed, or if this process lacks 3338 * super-user credentials and the sysctl tunable 3339 * 'security.bsd.unprivileged_syspmcs' is zero. 3340 */ 3341 3342 if (PMC_IS_SYSTEM_MODE(mode)) { 3343 if (jailed(curthread->td_ucred)) { 3344 error = EPERM; 3345 break; 3346 } 3347 if (!pmc_unprivileged_syspmcs) { 3348 error = priv_check(curthread, 3349 PRIV_PMC_SYSTEM); 3350 if (error) 3351 break; 3352 } 3353 } 3354 3355 /* 3356 * Look for valid values for 'pm_flags' 3357 */ 3358 3359 if ((pa.pm_flags & ~(PMC_F_DESCENDANTS | PMC_F_LOG_PROCCSW | 3360 PMC_F_LOG_PROCEXIT | PMC_F_CALLCHAIN)) != 0) { 3361 error = EINVAL; 3362 break; 3363 } 3364 3365 /* process logging options are not allowed for system PMCs */ 3366 if (PMC_IS_SYSTEM_MODE(mode) && (pa.pm_flags & 3367 (PMC_F_LOG_PROCCSW | PMC_F_LOG_PROCEXIT))) { 3368 error = EINVAL; 3369 break; 3370 } 3371 3372 /* 3373 * All sampling mode PMCs need to be able to interrupt the 3374 * CPU. 3375 */ 3376 if (PMC_IS_SAMPLING_MODE(mode)) 3377 caps |= PMC_CAP_INTERRUPT; 3378 3379 /* A valid class specifier should have been passed in. */ 3380 for (n = 0; n < md->pmd_nclass; n++) 3381 if (md->pmd_classdep[n].pcd_class == pa.pm_class) 3382 break; 3383 if (n == md->pmd_nclass) { 3384 error = EINVAL; 3385 break; 3386 } 3387 3388 /* The requested PMC capabilities should be feasible. */ 3389 if ((md->pmd_classdep[n].pcd_caps & caps) != caps) { 3390 error = EOPNOTSUPP; 3391 break; 3392 } 3393 3394 PMCDBG4(PMC,ALL,2, "event=%d caps=0x%x mode=%d cpu=%d", 3395 pa.pm_ev, caps, mode, cpu); 3396 3397 pmc = pmc_allocate_pmc_descriptor(); 3398 pmc->pm_id = PMC_ID_MAKE_ID(cpu,pa.pm_mode,pa.pm_class, 3399 PMC_ID_INVALID); 3400 pmc->pm_event = pa.pm_ev; 3401 pmc->pm_state = PMC_STATE_FREE; 3402 pmc->pm_caps = caps; 3403 pmc->pm_flags = pa.pm_flags; 3404 3405 /* switch thread to CPU 'cpu' */ 3406 pmc_save_cpu_binding(&pb); 3407 3408 #define PMC_IS_SHAREABLE_PMC(cpu, n) \ 3409 (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_state & \ 3410 PMC_PHW_FLAG_IS_SHAREABLE) 3411 #define PMC_IS_UNALLOCATED(cpu, n) \ 3412 (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_pmc == NULL) 3413 3414 if (PMC_IS_SYSTEM_MODE(mode)) { 3415 pmc_select_cpu(cpu); 3416 for (n = 0; n < (int) md->pmd_npmc; n++) { 3417 pcd = pmc_ri_to_classdep(md, n, &adjri); 3418 if (pmc_can_allocate_row(n, mode) == 0 && 3419 pmc_can_allocate_rowindex( 3420 curthread->td_proc, n, cpu) == 0 && 3421 (PMC_IS_UNALLOCATED(cpu, n) || 3422 PMC_IS_SHAREABLE_PMC(cpu, n)) && 3423 pcd->pcd_allocate_pmc(cpu, adjri, pmc, 3424 &pa) == 0) 3425 break; 3426 } 3427 } else { 3428 /* Process virtual mode */ 3429 for (n = 0; n < (int) md->pmd_npmc; n++) { 3430 pcd = pmc_ri_to_classdep(md, n, &adjri); 3431 if (pmc_can_allocate_row(n, mode) == 0 && 3432 pmc_can_allocate_rowindex( 3433 curthread->td_proc, n, 3434 PMC_CPU_ANY) == 0 && 3435 pcd->pcd_allocate_pmc(curthread->td_oncpu, 3436 adjri, pmc, &pa) == 0) 3437 break; 3438 } 3439 } 3440 3441 #undef PMC_IS_UNALLOCATED 3442 #undef PMC_IS_SHAREABLE_PMC 3443 3444 pmc_restore_cpu_binding(&pb); 3445 3446 if (n == (int) md->pmd_npmc) { 3447 pmc_destroy_pmc_descriptor(pmc); 3448 pmc = NULL; 3449 error = EINVAL; 3450 break; 3451 } 3452 3453 /* Fill in the correct value in the ID field */ 3454 pmc->pm_id = PMC_ID_MAKE_ID(cpu,mode,pa.pm_class,n); 3455 3456 PMCDBG5(PMC,ALL,2, "ev=%d class=%d mode=%d n=%d -> pmcid=%x", 3457 pmc->pm_event, pa.pm_class, mode, n, pmc->pm_id); 3458 3459 /* Process mode PMCs with logging enabled need log files */ 3460 if (pmc->pm_flags & (PMC_F_LOG_PROCEXIT | PMC_F_LOG_PROCCSW)) 3461 pmc->pm_flags |= PMC_F_NEEDS_LOGFILE; 3462 3463 /* All system mode sampling PMCs require a log file */ 3464 if (PMC_IS_SAMPLING_MODE(mode) && PMC_IS_SYSTEM_MODE(mode)) 3465 pmc->pm_flags |= PMC_F_NEEDS_LOGFILE; 3466 3467 /* 3468 * Configure global pmc's immediately 3469 */ 3470 3471 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pmc))) { 3472 3473 pmc_save_cpu_binding(&pb); 3474 pmc_select_cpu(cpu); 3475 3476 phw = pmc_pcpu[cpu]->pc_hwpmcs[n]; 3477 pcd = pmc_ri_to_classdep(md, n, &adjri); 3478 3479 if ((phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0 || 3480 (error = pcd->pcd_config_pmc(cpu, adjri, pmc)) != 0) { 3481 (void) pcd->pcd_release_pmc(cpu, adjri, pmc); 3482 pmc_destroy_pmc_descriptor(pmc); 3483 pmc = NULL; 3484 pmc_restore_cpu_binding(&pb); 3485 error = EPERM; 3486 break; 3487 } 3488 3489 pmc_restore_cpu_binding(&pb); 3490 } 3491 3492 pmc->pm_state = PMC_STATE_ALLOCATED; 3493 3494 /* 3495 * mark row disposition 3496 */ 3497 3498 if (PMC_IS_SYSTEM_MODE(mode)) 3499 PMC_MARK_ROW_STANDALONE(n); 3500 else 3501 PMC_MARK_ROW_THREAD(n); 3502 3503 /* 3504 * Register this PMC with the current thread as its owner. 3505 */ 3506 3507 if ((error = 3508 pmc_register_owner(curthread->td_proc, pmc)) != 0) { 3509 pmc_release_pmc_descriptor(pmc); 3510 pmc_destroy_pmc_descriptor(pmc); 3511 pmc = NULL; 3512 break; 3513 } 3514 3515 /* 3516 * Return the allocated index. 3517 */ 3518 3519 pa.pm_pmcid = pmc->pm_id; 3520 3521 error = copyout(&pa, arg, sizeof(pa)); 3522 } 3523 break; 3524 3525 3526 /* 3527 * Attach a PMC to a process. 3528 */ 3529 3530 case PMC_OP_PMCATTACH: 3531 { 3532 struct pmc *pm; 3533 struct proc *p; 3534 struct pmc_op_pmcattach a; 3535 3536 sx_assert(&pmc_sx, SX_XLOCKED); 3537 3538 if ((error = copyin(arg, &a, sizeof(a))) != 0) 3539 break; 3540 3541 if (a.pm_pid < 0) { 3542 error = EINVAL; 3543 break; 3544 } else if (a.pm_pid == 0) 3545 a.pm_pid = td->td_proc->p_pid; 3546 3547 if ((error = pmc_find_pmc(a.pm_pmc, &pm)) != 0) 3548 break; 3549 3550 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) { 3551 error = EINVAL; 3552 break; 3553 } 3554 3555 /* PMCs may be (re)attached only when allocated or stopped */ 3556 if (pm->pm_state == PMC_STATE_RUNNING) { 3557 error = EBUSY; 3558 break; 3559 } else if (pm->pm_state != PMC_STATE_ALLOCATED && 3560 pm->pm_state != PMC_STATE_STOPPED) { 3561 error = EINVAL; 3562 break; 3563 } 3564 3565 /* lookup pid */ 3566 if ((p = pfind(a.pm_pid)) == NULL) { 3567 error = ESRCH; 3568 break; 3569 } 3570 3571 /* 3572 * Ignore processes that are working on exiting. 3573 */ 3574 if (p->p_flag & P_WEXIT) { 3575 error = ESRCH; 3576 PROC_UNLOCK(p); /* pfind() returns a locked process */ 3577 break; 3578 } 3579 3580 /* 3581 * we are allowed to attach a PMC to a process if 3582 * we can debug it. 3583 */ 3584 error = p_candebug(curthread, p); 3585 3586 PROC_UNLOCK(p); 3587 3588 if (error == 0) 3589 error = pmc_attach_process(p, pm); 3590 } 3591 break; 3592 3593 3594 /* 3595 * Detach an attached PMC from a process. 3596 */ 3597 3598 case PMC_OP_PMCDETACH: 3599 { 3600 struct pmc *pm; 3601 struct proc *p; 3602 struct pmc_op_pmcattach a; 3603 3604 if ((error = copyin(arg, &a, sizeof(a))) != 0) 3605 break; 3606 3607 if (a.pm_pid < 0) { 3608 error = EINVAL; 3609 break; 3610 } else if (a.pm_pid == 0) 3611 a.pm_pid = td->td_proc->p_pid; 3612 3613 if ((error = pmc_find_pmc(a.pm_pmc, &pm)) != 0) 3614 break; 3615 3616 if ((p = pfind(a.pm_pid)) == NULL) { 3617 error = ESRCH; 3618 break; 3619 } 3620 3621 /* 3622 * Treat processes that are in the process of exiting 3623 * as if they were not present. 3624 */ 3625 3626 if (p->p_flag & P_WEXIT) 3627 error = ESRCH; 3628 3629 PROC_UNLOCK(p); /* pfind() returns a locked process */ 3630 3631 if (error == 0) 3632 error = pmc_detach_process(p, pm); 3633 } 3634 break; 3635 3636 3637 /* 3638 * Retrieve the MSR number associated with the counter 3639 * 'pmc_id'. This allows processes to directly use RDPMC 3640 * instructions to read their PMCs, without the overhead of a 3641 * system call. 3642 */ 3643 3644 case PMC_OP_PMCGETMSR: 3645 { 3646 int adjri, ri; 3647 struct pmc *pm; 3648 struct pmc_target *pt; 3649 struct pmc_op_getmsr gm; 3650 struct pmc_classdep *pcd; 3651 3652 PMC_DOWNGRADE_SX(); 3653 3654 if ((error = copyin(arg, &gm, sizeof(gm))) != 0) 3655 break; 3656 3657 if ((error = pmc_find_pmc(gm.pm_pmcid, &pm)) != 0) 3658 break; 3659 3660 /* 3661 * The allocated PMC has to be a process virtual PMC, 3662 * i.e., of type MODE_T[CS]. Global PMCs can only be 3663 * read using the PMCREAD operation since they may be 3664 * allocated on a different CPU than the one we could 3665 * be running on at the time of the RDPMC instruction. 3666 * 3667 * The GETMSR operation is not allowed for PMCs that 3668 * are inherited across processes. 3669 */ 3670 3671 if (!PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)) || 3672 (pm->pm_flags & PMC_F_DESCENDANTS)) { 3673 error = EINVAL; 3674 break; 3675 } 3676 3677 /* 3678 * It only makes sense to use a RDPMC (or its 3679 * equivalent instruction on non-x86 architectures) on 3680 * a process that has allocated and attached a PMC to 3681 * itself. Conversely the PMC is only allowed to have 3682 * one process attached to it -- its owner. 3683 */ 3684 3685 if ((pt = LIST_FIRST(&pm->pm_targets)) == NULL || 3686 LIST_NEXT(pt, pt_next) != NULL || 3687 pt->pt_process->pp_proc != pm->pm_owner->po_owner) { 3688 error = EINVAL; 3689 break; 3690 } 3691 3692 ri = PMC_TO_ROWINDEX(pm); 3693 pcd = pmc_ri_to_classdep(md, ri, &adjri); 3694 3695 /* PMC class has no 'GETMSR' support */ 3696 if (pcd->pcd_get_msr == NULL) { 3697 error = ENOSYS; 3698 break; 3699 } 3700 3701 if ((error = (*pcd->pcd_get_msr)(adjri, &gm.pm_msr)) < 0) 3702 break; 3703 3704 if ((error = copyout(&gm, arg, sizeof(gm))) < 0) 3705 break; 3706 3707 /* 3708 * Mark our process as using MSRs. Update machine 3709 * state using a forced context switch. 3710 */ 3711 3712 pt->pt_process->pp_flags |= PMC_PP_ENABLE_MSR_ACCESS; 3713 pmc_force_context_switch(); 3714 3715 } 3716 break; 3717 3718 /* 3719 * Release an allocated PMC 3720 */ 3721 3722 case PMC_OP_PMCRELEASE: 3723 { 3724 pmc_id_t pmcid; 3725 struct pmc *pm; 3726 struct pmc_owner *po; 3727 struct pmc_op_simple sp; 3728 3729 /* 3730 * Find PMC pointer for the named PMC. 3731 * 3732 * Use pmc_release_pmc_descriptor() to switch off the 3733 * PMC, remove all its target threads, and remove the 3734 * PMC from its owner's list. 3735 * 3736 * Remove the owner record if this is the last PMC 3737 * owned. 3738 * 3739 * Free up space. 3740 */ 3741 3742 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 3743 break; 3744 3745 pmcid = sp.pm_pmcid; 3746 3747 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 3748 break; 3749 3750 po = pm->pm_owner; 3751 pmc_release_pmc_descriptor(pm); 3752 pmc_maybe_remove_owner(po); 3753 pmc_destroy_pmc_descriptor(pm); 3754 } 3755 break; 3756 3757 3758 /* 3759 * Read and/or write a PMC. 3760 */ 3761 3762 case PMC_OP_PMCRW: 3763 { 3764 int adjri; 3765 struct pmc *pm; 3766 uint32_t cpu, ri; 3767 pmc_value_t oldvalue; 3768 struct pmc_binding pb; 3769 struct pmc_op_pmcrw prw; 3770 struct pmc_classdep *pcd; 3771 struct pmc_op_pmcrw *pprw; 3772 3773 PMC_DOWNGRADE_SX(); 3774 3775 if ((error = copyin(arg, &prw, sizeof(prw))) != 0) 3776 break; 3777 3778 ri = 0; 3779 PMCDBG2(PMC,OPS,1, "rw id=%d flags=0x%x", prw.pm_pmcid, 3780 prw.pm_flags); 3781 3782 /* must have at least one flag set */ 3783 if ((prw.pm_flags & (PMC_F_OLDVALUE|PMC_F_NEWVALUE)) == 0) { 3784 error = EINVAL; 3785 break; 3786 } 3787 3788 /* locate pmc descriptor */ 3789 if ((error = pmc_find_pmc(prw.pm_pmcid, &pm)) != 0) 3790 break; 3791 3792 /* Can't read a PMC that hasn't been started. */ 3793 if (pm->pm_state != PMC_STATE_ALLOCATED && 3794 pm->pm_state != PMC_STATE_STOPPED && 3795 pm->pm_state != PMC_STATE_RUNNING) { 3796 error = EINVAL; 3797 break; 3798 } 3799 3800 /* writing a new value is allowed only for 'STOPPED' pmcs */ 3801 if (pm->pm_state == PMC_STATE_RUNNING && 3802 (prw.pm_flags & PMC_F_NEWVALUE)) { 3803 error = EBUSY; 3804 break; 3805 } 3806 3807 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) { 3808 3809 /* 3810 * If this PMC is attached to its owner (i.e., 3811 * the process requesting this operation) and 3812 * is running, then attempt to get an 3813 * upto-date reading from hardware for a READ. 3814 * Writes are only allowed when the PMC is 3815 * stopped, so only update the saved value 3816 * field. 3817 * 3818 * If the PMC is not running, or is not 3819 * attached to its owner, read/write to the 3820 * savedvalue field. 3821 */ 3822 3823 ri = PMC_TO_ROWINDEX(pm); 3824 pcd = pmc_ri_to_classdep(md, ri, &adjri); 3825 3826 mtx_pool_lock_spin(pmc_mtxpool, pm); 3827 cpu = curthread->td_oncpu; 3828 3829 if (prw.pm_flags & PMC_F_OLDVALUE) { 3830 if ((pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) && 3831 (pm->pm_state == PMC_STATE_RUNNING)) 3832 error = (*pcd->pcd_read_pmc)(cpu, adjri, 3833 &oldvalue); 3834 else 3835 oldvalue = pm->pm_gv.pm_savedvalue; 3836 } 3837 if (prw.pm_flags & PMC_F_NEWVALUE) 3838 pm->pm_gv.pm_savedvalue = prw.pm_value; 3839 3840 mtx_pool_unlock_spin(pmc_mtxpool, pm); 3841 3842 } else { /* System mode PMCs */ 3843 cpu = PMC_TO_CPU(pm); 3844 ri = PMC_TO_ROWINDEX(pm); 3845 pcd = pmc_ri_to_classdep(md, ri, &adjri); 3846 3847 if (!pmc_cpu_is_active(cpu)) { 3848 error = ENXIO; 3849 break; 3850 } 3851 3852 /* move this thread to CPU 'cpu' */ 3853 pmc_save_cpu_binding(&pb); 3854 pmc_select_cpu(cpu); 3855 3856 critical_enter(); 3857 /* save old value */ 3858 if (prw.pm_flags & PMC_F_OLDVALUE) 3859 if ((error = (*pcd->pcd_read_pmc)(cpu, adjri, 3860 &oldvalue))) 3861 goto error; 3862 /* write out new value */ 3863 if (prw.pm_flags & PMC_F_NEWVALUE) 3864 error = (*pcd->pcd_write_pmc)(cpu, adjri, 3865 prw.pm_value); 3866 error: 3867 critical_exit(); 3868 pmc_restore_cpu_binding(&pb); 3869 if (error) 3870 break; 3871 } 3872 3873 pprw = (struct pmc_op_pmcrw *) arg; 3874 3875 #ifdef HWPMC_DEBUG 3876 if (prw.pm_flags & PMC_F_NEWVALUE) 3877 PMCDBG3(PMC,OPS,2, "rw id=%d new %jx -> old %jx", 3878 ri, prw.pm_value, oldvalue); 3879 else if (prw.pm_flags & PMC_F_OLDVALUE) 3880 PMCDBG2(PMC,OPS,2, "rw id=%d -> old %jx", ri, oldvalue); 3881 #endif 3882 3883 /* return old value if requested */ 3884 if (prw.pm_flags & PMC_F_OLDVALUE) 3885 if ((error = copyout(&oldvalue, &pprw->pm_value, 3886 sizeof(prw.pm_value)))) 3887 break; 3888 3889 } 3890 break; 3891 3892 3893 /* 3894 * Set the sampling rate for a sampling mode PMC and the 3895 * initial count for a counting mode PMC. 3896 */ 3897 3898 case PMC_OP_PMCSETCOUNT: 3899 { 3900 struct pmc *pm; 3901 struct pmc_op_pmcsetcount sc; 3902 3903 PMC_DOWNGRADE_SX(); 3904 3905 if ((error = copyin(arg, &sc, sizeof(sc))) != 0) 3906 break; 3907 3908 if ((error = pmc_find_pmc(sc.pm_pmcid, &pm)) != 0) 3909 break; 3910 3911 if (pm->pm_state == PMC_STATE_RUNNING) { 3912 error = EBUSY; 3913 break; 3914 } 3915 3916 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 3917 pm->pm_sc.pm_reloadcount = sc.pm_count; 3918 else 3919 pm->pm_sc.pm_initial = sc.pm_count; 3920 } 3921 break; 3922 3923 3924 /* 3925 * Start a PMC. 3926 */ 3927 3928 case PMC_OP_PMCSTART: 3929 { 3930 pmc_id_t pmcid; 3931 struct pmc *pm; 3932 struct pmc_op_simple sp; 3933 3934 sx_assert(&pmc_sx, SX_XLOCKED); 3935 3936 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 3937 break; 3938 3939 pmcid = sp.pm_pmcid; 3940 3941 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 3942 break; 3943 3944 KASSERT(pmcid == pm->pm_id, 3945 ("[pmc,%d] pmcid %x != id %x", __LINE__, 3946 pm->pm_id, pmcid)); 3947 3948 if (pm->pm_state == PMC_STATE_RUNNING) /* already running */ 3949 break; 3950 else if (pm->pm_state != PMC_STATE_STOPPED && 3951 pm->pm_state != PMC_STATE_ALLOCATED) { 3952 error = EINVAL; 3953 break; 3954 } 3955 3956 error = pmc_start(pm); 3957 } 3958 break; 3959 3960 3961 /* 3962 * Stop a PMC. 3963 */ 3964 3965 case PMC_OP_PMCSTOP: 3966 { 3967 pmc_id_t pmcid; 3968 struct pmc *pm; 3969 struct pmc_op_simple sp; 3970 3971 PMC_DOWNGRADE_SX(); 3972 3973 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 3974 break; 3975 3976 pmcid = sp.pm_pmcid; 3977 3978 /* 3979 * Mark the PMC as inactive and invoke the MD stop 3980 * routines if needed. 3981 */ 3982 3983 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 3984 break; 3985 3986 KASSERT(pmcid == pm->pm_id, 3987 ("[pmc,%d] pmc id %x != pmcid %x", __LINE__, 3988 pm->pm_id, pmcid)); 3989 3990 if (pm->pm_state == PMC_STATE_STOPPED) /* already stopped */ 3991 break; 3992 else if (pm->pm_state != PMC_STATE_RUNNING) { 3993 error = EINVAL; 3994 break; 3995 } 3996 3997 error = pmc_stop(pm); 3998 } 3999 break; 4000 4001 4002 /* 4003 * Write a user supplied value to the log file. 4004 */ 4005 4006 case PMC_OP_WRITELOG: 4007 { 4008 struct pmc_op_writelog wl; 4009 struct pmc_owner *po; 4010 4011 PMC_DOWNGRADE_SX(); 4012 4013 if ((error = copyin(arg, &wl, sizeof(wl))) != 0) 4014 break; 4015 4016 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 4017 error = EINVAL; 4018 break; 4019 } 4020 4021 if ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) { 4022 error = EINVAL; 4023 break; 4024 } 4025 4026 error = pmclog_process_userlog(po, &wl); 4027 } 4028 break; 4029 4030 4031 default: 4032 error = EINVAL; 4033 break; 4034 } 4035 4036 if (is_sx_downgraded) 4037 sx_sunlock(&pmc_sx); 4038 else 4039 sx_xunlock(&pmc_sx); 4040 done_syscall: 4041 if (error) 4042 atomic_add_int(&pmc_stats.pm_syscall_errors, 1); 4043 4044 return (error); 4045 } 4046 4047 /* 4048 * Helper functions 4049 */ 4050 4051 4052 /* 4053 * Mark the thread as needing callchain capture and post an AST. The 4054 * actual callchain capture will be done in a context where it is safe 4055 * to take page faults. 4056 */ 4057 4058 static void 4059 pmc_post_callchain_callback(void) 4060 { 4061 struct thread *td; 4062 4063 td = curthread; 4064 4065 /* 4066 * If there is multiple PMCs for the same interrupt ignore new post 4067 */ 4068 if (td->td_pflags & TDP_CALLCHAIN) 4069 return; 4070 4071 /* 4072 * Mark this thread as needing callchain capture. 4073 * `td->td_pflags' will be safe to touch because this thread 4074 * was in user space when it was interrupted. 4075 */ 4076 td->td_pflags |= TDP_CALLCHAIN; 4077 4078 /* 4079 * Don't let this thread migrate between CPUs until callchain 4080 * capture completes. 4081 */ 4082 sched_pin(); 4083 4084 return; 4085 } 4086 4087 /* 4088 * Interrupt processing. 4089 * 4090 * Find a free slot in the per-cpu array of samples and capture the 4091 * current callchain there. If a sample was successfully added, a bit 4092 * is set in mask 'pmc_cpumask' denoting that the DO_SAMPLES hook 4093 * needs to be invoked from the clock handler. 4094 * 4095 * This function is meant to be called from an NMI handler. It cannot 4096 * use any of the locking primitives supplied by the OS. 4097 */ 4098 4099 int 4100 pmc_process_interrupt(int cpu, int ring, struct pmc *pm, struct trapframe *tf, 4101 int inuserspace) 4102 { 4103 int error, callchaindepth; 4104 struct thread *td; 4105 struct pmc_sample *ps; 4106 struct pmc_samplebuffer *psb; 4107 4108 error = 0; 4109 4110 /* 4111 * Allocate space for a sample buffer. 4112 */ 4113 psb = pmc_pcpu[cpu]->pc_sb[ring]; 4114 4115 ps = psb->ps_write; 4116 if (ps->ps_nsamples) { /* in use, reader hasn't caught up */ 4117 CPU_SET_ATOMIC(cpu, &pm->pm_stalled); 4118 atomic_add_int(&pmc_stats.pm_intr_bufferfull, 1); 4119 PMCDBG6(SAM,INT,1,"(spc) cpu=%d pm=%p tf=%p um=%d wr=%d rd=%d", 4120 cpu, pm, (void *) tf, inuserspace, 4121 (int) (psb->ps_write - psb->ps_samples), 4122 (int) (psb->ps_read - psb->ps_samples)); 4123 callchaindepth = 1; 4124 error = ENOMEM; 4125 goto done; 4126 } 4127 4128 4129 /* Fill in entry. */ 4130 PMCDBG6(SAM,INT,1,"cpu=%d pm=%p tf=%p um=%d wr=%d rd=%d", cpu, pm, 4131 (void *) tf, inuserspace, 4132 (int) (psb->ps_write - psb->ps_samples), 4133 (int) (psb->ps_read - psb->ps_samples)); 4134 4135 KASSERT(pm->pm_runcount >= 0, 4136 ("[pmc,%d] pm=%p runcount %d", __LINE__, (void *) pm, 4137 pm->pm_runcount)); 4138 4139 atomic_add_rel_int(&pm->pm_runcount, 1); /* hold onto PMC */ 4140 4141 ps->ps_pmc = pm; 4142 if ((td = curthread) && td->td_proc) 4143 ps->ps_pid = td->td_proc->p_pid; 4144 else 4145 ps->ps_pid = -1; 4146 ps->ps_cpu = cpu; 4147 ps->ps_td = td; 4148 ps->ps_flags = inuserspace ? PMC_CC_F_USERSPACE : 0; 4149 4150 callchaindepth = (pm->pm_flags & PMC_F_CALLCHAIN) ? 4151 pmc_callchaindepth : 1; 4152 4153 if (callchaindepth == 1) 4154 ps->ps_pc[0] = PMC_TRAPFRAME_TO_PC(tf); 4155 else { 4156 /* 4157 * Kernel stack traversals can be done immediately, 4158 * while we defer to an AST for user space traversals. 4159 */ 4160 if (!inuserspace) { 4161 callchaindepth = 4162 pmc_save_kernel_callchain(ps->ps_pc, 4163 callchaindepth, tf); 4164 } else { 4165 pmc_post_callchain_callback(); 4166 callchaindepth = PMC_SAMPLE_INUSE; 4167 } 4168 } 4169 4170 ps->ps_nsamples = callchaindepth; /* mark entry as in use */ 4171 4172 /* increment write pointer, modulo ring buffer size */ 4173 ps++; 4174 if (ps == psb->ps_fence) 4175 psb->ps_write = psb->ps_samples; 4176 else 4177 psb->ps_write = ps; 4178 4179 done: 4180 /* mark CPU as needing processing */ 4181 if (callchaindepth != PMC_SAMPLE_INUSE) 4182 CPU_SET_ATOMIC(cpu, &pmc_cpumask); 4183 4184 return (error); 4185 } 4186 4187 /* 4188 * Capture a user call chain. This function will be called from ast() 4189 * before control returns to userland and before the process gets 4190 * rescheduled. 4191 */ 4192 4193 static void 4194 pmc_capture_user_callchain(int cpu, int ring, struct trapframe *tf) 4195 { 4196 struct pmc *pm; 4197 struct thread *td; 4198 struct pmc_sample *ps, *ps_end; 4199 struct pmc_samplebuffer *psb; 4200 #ifdef INVARIANTS 4201 int ncallchains; 4202 int nfree; 4203 #endif 4204 4205 psb = pmc_pcpu[cpu]->pc_sb[ring]; 4206 td = curthread; 4207 4208 KASSERT(td->td_pflags & TDP_CALLCHAIN, 4209 ("[pmc,%d] Retrieving callchain for thread that doesn't want it", 4210 __LINE__)); 4211 4212 #ifdef INVARIANTS 4213 ncallchains = 0; 4214 nfree = 0; 4215 #endif 4216 4217 /* 4218 * Iterate through all deferred callchain requests. 4219 * Walk from the current read pointer to the current 4220 * write pointer. 4221 */ 4222 4223 ps = psb->ps_read; 4224 ps_end = psb->ps_write; 4225 do { 4226 #ifdef INVARIANTS 4227 if ((ps->ps_pmc == NULL) || 4228 (ps->ps_pmc->pm_state != PMC_STATE_RUNNING)) 4229 nfree++; 4230 #endif 4231 if (ps->ps_nsamples != PMC_SAMPLE_INUSE) 4232 goto next; 4233 if (ps->ps_td != td) 4234 goto next; 4235 4236 KASSERT(ps->ps_cpu == cpu, 4237 ("[pmc,%d] cpu mismatch ps_cpu=%d pcpu=%d", __LINE__, 4238 ps->ps_cpu, PCPU_GET(cpuid))); 4239 4240 pm = ps->ps_pmc; 4241 4242 KASSERT(pm->pm_flags & PMC_F_CALLCHAIN, 4243 ("[pmc,%d] Retrieving callchain for PMC that doesn't " 4244 "want it", __LINE__)); 4245 4246 KASSERT(pm->pm_runcount > 0, 4247 ("[pmc,%d] runcount %d", __LINE__, pm->pm_runcount)); 4248 4249 /* 4250 * Retrieve the callchain and mark the sample buffer 4251 * as 'processable' by the timer tick sweep code. 4252 */ 4253 ps->ps_nsamples = pmc_save_user_callchain(ps->ps_pc, 4254 pmc_callchaindepth, tf); 4255 4256 #ifdef INVARIANTS 4257 ncallchains++; 4258 #endif 4259 4260 next: 4261 /* increment the pointer, modulo sample ring size */ 4262 if (++ps == psb->ps_fence) 4263 ps = psb->ps_samples; 4264 } while (ps != ps_end); 4265 4266 #ifdef INVARIANTS 4267 KASSERT(ncallchains > 0 || nfree > 0, 4268 ("[pmc,%d] cpu %d didn't find a sample to collect", __LINE__, 4269 cpu)); 4270 #endif 4271 4272 KASSERT(td->td_pinned == 1, 4273 ("[pmc,%d] invalid td_pinned value", __LINE__)); 4274 sched_unpin(); /* Can migrate safely now. */ 4275 4276 /* mark CPU as needing processing */ 4277 CPU_SET_ATOMIC(cpu, &pmc_cpumask); 4278 4279 return; 4280 } 4281 4282 /* 4283 * Process saved PC samples. 4284 */ 4285 4286 static void 4287 pmc_process_samples(int cpu, int ring) 4288 { 4289 struct pmc *pm; 4290 int adjri, n; 4291 struct thread *td; 4292 struct pmc_owner *po; 4293 struct pmc_sample *ps; 4294 struct pmc_classdep *pcd; 4295 struct pmc_samplebuffer *psb; 4296 4297 KASSERT(PCPU_GET(cpuid) == cpu, 4298 ("[pmc,%d] not on the correct CPU pcpu=%d cpu=%d", __LINE__, 4299 PCPU_GET(cpuid), cpu)); 4300 4301 psb = pmc_pcpu[cpu]->pc_sb[ring]; 4302 4303 for (n = 0; n < pmc_nsamples; n++) { /* bound on #iterations */ 4304 4305 ps = psb->ps_read; 4306 if (ps->ps_nsamples == PMC_SAMPLE_FREE) 4307 break; 4308 4309 pm = ps->ps_pmc; 4310 4311 KASSERT(pm->pm_runcount > 0, 4312 ("[pmc,%d] pm=%p runcount %d", __LINE__, (void *) pm, 4313 pm->pm_runcount)); 4314 4315 po = pm->pm_owner; 4316 4317 KASSERT(PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)), 4318 ("[pmc,%d] pmc=%p non-sampling mode=%d", __LINE__, 4319 pm, PMC_TO_MODE(pm))); 4320 4321 /* Ignore PMCs that have been switched off */ 4322 if (pm->pm_state != PMC_STATE_RUNNING) 4323 goto entrydone; 4324 4325 /* If there is a pending AST wait for completion */ 4326 if (ps->ps_nsamples == PMC_SAMPLE_INUSE) { 4327 /* Need a rescan at a later time. */ 4328 CPU_SET_ATOMIC(cpu, &pmc_cpumask); 4329 break; 4330 } 4331 4332 PMCDBG6(SAM,OPS,1,"cpu=%d pm=%p n=%d fl=%x wr=%d rd=%d", cpu, 4333 pm, ps->ps_nsamples, ps->ps_flags, 4334 (int) (psb->ps_write - psb->ps_samples), 4335 (int) (psb->ps_read - psb->ps_samples)); 4336 4337 /* 4338 * If this is a process-mode PMC that is attached to 4339 * its owner, and if the PC is in user mode, update 4340 * profiling statistics like timer-based profiling 4341 * would have done. 4342 */ 4343 if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) { 4344 if (ps->ps_flags & PMC_CC_F_USERSPACE) { 4345 td = FIRST_THREAD_IN_PROC(po->po_owner); 4346 addupc_intr(td, ps->ps_pc[0], 1); 4347 } 4348 goto entrydone; 4349 } 4350 4351 /* 4352 * Otherwise, this is either a sampling mode PMC that 4353 * is attached to a different process than its owner, 4354 * or a system-wide sampling PMC. Dispatch a log 4355 * entry to the PMC's owner process. 4356 */ 4357 pmclog_process_callchain(pm, ps); 4358 4359 entrydone: 4360 ps->ps_nsamples = 0; /* mark entry as free */ 4361 atomic_subtract_rel_int(&pm->pm_runcount, 1); 4362 4363 /* increment read pointer, modulo sample size */ 4364 if (++ps == psb->ps_fence) 4365 psb->ps_read = psb->ps_samples; 4366 else 4367 psb->ps_read = ps; 4368 } 4369 4370 atomic_add_int(&pmc_stats.pm_log_sweeps, 1); 4371 4372 /* Do not re-enable stalled PMCs if we failed to process any samples */ 4373 if (n == 0) 4374 return; 4375 4376 /* 4377 * Restart any stalled sampling PMCs on this CPU. 4378 * 4379 * If the NMI handler sets the pm_stalled field of a PMC after 4380 * the check below, we'll end up processing the stalled PMC at 4381 * the next hardclock tick. 4382 */ 4383 for (n = 0; n < md->pmd_npmc; n++) { 4384 pcd = pmc_ri_to_classdep(md, n, &adjri); 4385 KASSERT(pcd != NULL, 4386 ("[pmc,%d] null pcd ri=%d", __LINE__, n)); 4387 (void) (*pcd->pcd_get_config)(cpu,adjri,&pm); 4388 4389 if (pm == NULL || /* !cfg'ed */ 4390 pm->pm_state != PMC_STATE_RUNNING || /* !active */ 4391 !PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)) || /* !sampling */ 4392 !CPU_ISSET(cpu, &pm->pm_cpustate) || /* !desired */ 4393 !CPU_ISSET(cpu, &pm->pm_stalled)) /* !stalled */ 4394 continue; 4395 4396 CPU_CLR_ATOMIC(cpu, &pm->pm_stalled); 4397 (*pcd->pcd_start_pmc)(cpu, adjri); 4398 } 4399 } 4400 4401 /* 4402 * Event handlers. 4403 */ 4404 4405 /* 4406 * Handle a process exit. 4407 * 4408 * Remove this process from all hash tables. If this process 4409 * owned any PMCs, turn off those PMCs and deallocate them, 4410 * removing any associations with target processes. 4411 * 4412 * This function will be called by the last 'thread' of a 4413 * process. 4414 * 4415 * XXX This eventhandler gets called early in the exit process. 4416 * Consider using a 'hook' invocation from thread_exit() or equivalent 4417 * spot. Another negative is that kse_exit doesn't seem to call 4418 * exit1() [??]. 4419 * 4420 */ 4421 4422 static void 4423 pmc_process_exit(void *arg __unused, struct proc *p) 4424 { 4425 struct pmc *pm; 4426 int adjri, cpu; 4427 unsigned int ri; 4428 int is_using_hwpmcs; 4429 struct pmc_owner *po; 4430 struct pmc_process *pp; 4431 struct pmc_classdep *pcd; 4432 pmc_value_t newvalue, tmp; 4433 4434 PROC_LOCK(p); 4435 is_using_hwpmcs = p->p_flag & P_HWPMC; 4436 PROC_UNLOCK(p); 4437 4438 /* 4439 * Log a sysexit event to all SS PMC owners. 4440 */ 4441 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 4442 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 4443 pmclog_process_sysexit(po, p->p_pid); 4444 4445 if (!is_using_hwpmcs) 4446 return; 4447 4448 PMC_GET_SX_XLOCK(); 4449 PMCDBG3(PRC,EXT,1,"process-exit proc=%p (%d, %s)", p, p->p_pid, 4450 p->p_comm); 4451 4452 /* 4453 * Since this code is invoked by the last thread in an exiting 4454 * process, we would have context switched IN at some prior 4455 * point. However, with PREEMPTION, kernel mode context 4456 * switches may happen any time, so we want to disable a 4457 * context switch OUT till we get any PMCs targeting this 4458 * process off the hardware. 4459 * 4460 * We also need to atomically remove this process' 4461 * entry from our target process hash table, using 4462 * PMC_FLAG_REMOVE. 4463 */ 4464 PMCDBG3(PRC,EXT,1, "process-exit proc=%p (%d, %s)", p, p->p_pid, 4465 p->p_comm); 4466 4467 critical_enter(); /* no preemption */ 4468 4469 cpu = curthread->td_oncpu; 4470 4471 if ((pp = pmc_find_process_descriptor(p, 4472 PMC_FLAG_REMOVE)) != NULL) { 4473 4474 PMCDBG2(PRC,EXT,2, 4475 "process-exit proc=%p pmc-process=%p", p, pp); 4476 4477 /* 4478 * The exiting process could the target of 4479 * some PMCs which will be running on 4480 * currently executing CPU. 4481 * 4482 * We need to turn these PMCs off like we 4483 * would do at context switch OUT time. 4484 */ 4485 for (ri = 0; ri < md->pmd_npmc; ri++) { 4486 4487 /* 4488 * Pick up the pmc pointer from hardware 4489 * state similar to the CSW_OUT code. 4490 */ 4491 pm = NULL; 4492 4493 pcd = pmc_ri_to_classdep(md, ri, &adjri); 4494 4495 (void) (*pcd->pcd_get_config)(cpu, adjri, &pm); 4496 4497 PMCDBG2(PRC,EXT,2, "ri=%d pm=%p", ri, pm); 4498 4499 if (pm == NULL || 4500 !PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) 4501 continue; 4502 4503 PMCDBG4(PRC,EXT,2, "ppmcs[%d]=%p pm=%p " 4504 "state=%d", ri, pp->pp_pmcs[ri].pp_pmc, 4505 pm, pm->pm_state); 4506 4507 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 4508 ("[pmc,%d] ri mismatch pmc(%d) ri(%d)", 4509 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 4510 4511 KASSERT(pm == pp->pp_pmcs[ri].pp_pmc, 4512 ("[pmc,%d] pm %p != pp_pmcs[%d] %p", 4513 __LINE__, pm, ri, pp->pp_pmcs[ri].pp_pmc)); 4514 4515 KASSERT(pm->pm_runcount > 0, 4516 ("[pmc,%d] bad runcount ri %d rc %d", 4517 __LINE__, ri, pm->pm_runcount)); 4518 4519 /* 4520 * Change desired state, and then stop if not 4521 * stalled. This two-step dance should avoid 4522 * race conditions where an interrupt re-enables 4523 * the PMC after this code has already checked 4524 * the pm_stalled flag. 4525 */ 4526 if (CPU_ISSET(cpu, &pm->pm_cpustate)) { 4527 CPU_CLR_ATOMIC(cpu, &pm->pm_cpustate); 4528 if (!CPU_ISSET(cpu, &pm->pm_stalled)) { 4529 (void) pcd->pcd_stop_pmc(cpu, adjri); 4530 pcd->pcd_read_pmc(cpu, adjri, 4531 &newvalue); 4532 tmp = newvalue - 4533 PMC_PCPU_SAVED(cpu,ri); 4534 4535 mtx_pool_lock_spin(pmc_mtxpool, pm); 4536 pm->pm_gv.pm_savedvalue += tmp; 4537 pp->pp_pmcs[ri].pp_pmcval += tmp; 4538 mtx_pool_unlock_spin(pmc_mtxpool, pm); 4539 } 4540 } 4541 4542 atomic_subtract_rel_int(&pm->pm_runcount,1); 4543 4544 KASSERT((int) pm->pm_runcount >= 0, 4545 ("[pmc,%d] runcount is %d", __LINE__, ri)); 4546 4547 (void) pcd->pcd_config_pmc(cpu, adjri, NULL); 4548 } 4549 4550 /* 4551 * Inform the MD layer of this pseudo "context switch 4552 * out" 4553 */ 4554 (void) md->pmd_switch_out(pmc_pcpu[cpu], pp); 4555 4556 critical_exit(); /* ok to be pre-empted now */ 4557 4558 /* 4559 * Unlink this process from the PMCs that are 4560 * targeting it. This will send a signal to 4561 * all PMC owner's whose PMCs are orphaned. 4562 * 4563 * Log PMC value at exit time if requested. 4564 */ 4565 for (ri = 0; ri < md->pmd_npmc; ri++) 4566 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) { 4567 if (pm->pm_flags & PMC_F_NEEDS_LOGFILE && 4568 PMC_IS_COUNTING_MODE(PMC_TO_MODE(pm))) 4569 pmclog_process_procexit(pm, pp); 4570 pmc_unlink_target_process(pm, pp); 4571 } 4572 free(pp, M_PMC); 4573 4574 } else 4575 critical_exit(); /* pp == NULL */ 4576 4577 4578 /* 4579 * If the process owned PMCs, free them up and free up 4580 * memory. 4581 */ 4582 if ((po = pmc_find_owner_descriptor(p)) != NULL) { 4583 pmc_remove_owner(po); 4584 pmc_destroy_owner_descriptor(po); 4585 } 4586 4587 sx_xunlock(&pmc_sx); 4588 } 4589 4590 /* 4591 * Handle a process fork. 4592 * 4593 * If the parent process 'p1' is under HWPMC monitoring, then copy 4594 * over any attached PMCs that have 'do_descendants' semantics. 4595 */ 4596 4597 static void 4598 pmc_process_fork(void *arg __unused, struct proc *p1, struct proc *newproc, 4599 int flags) 4600 { 4601 int is_using_hwpmcs; 4602 unsigned int ri; 4603 uint32_t do_descendants; 4604 struct pmc *pm; 4605 struct pmc_owner *po; 4606 struct pmc_process *ppnew, *ppold; 4607 4608 (void) flags; /* unused parameter */ 4609 4610 PROC_LOCK(p1); 4611 is_using_hwpmcs = p1->p_flag & P_HWPMC; 4612 PROC_UNLOCK(p1); 4613 4614 /* 4615 * If there are system-wide sampling PMCs active, we need to 4616 * log all fork events to their owner's logs. 4617 */ 4618 4619 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 4620 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 4621 pmclog_process_procfork(po, p1->p_pid, newproc->p_pid); 4622 4623 if (!is_using_hwpmcs) 4624 return; 4625 4626 PMC_GET_SX_XLOCK(); 4627 PMCDBG4(PMC,FRK,1, "process-fork proc=%p (%d, %s) -> %p", p1, 4628 p1->p_pid, p1->p_comm, newproc); 4629 4630 /* 4631 * If the parent process (curthread->td_proc) is a 4632 * target of any PMCs, look for PMCs that are to be 4633 * inherited, and link these into the new process 4634 * descriptor. 4635 */ 4636 if ((ppold = pmc_find_process_descriptor(curthread->td_proc, 4637 PMC_FLAG_NONE)) == NULL) 4638 goto done; /* nothing to do */ 4639 4640 do_descendants = 0; 4641 for (ri = 0; ri < md->pmd_npmc; ri++) 4642 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL) 4643 do_descendants |= pm->pm_flags & PMC_F_DESCENDANTS; 4644 if (do_descendants == 0) /* nothing to do */ 4645 goto done; 4646 4647 /* allocate a descriptor for the new process */ 4648 if ((ppnew = pmc_find_process_descriptor(newproc, 4649 PMC_FLAG_ALLOCATE)) == NULL) 4650 goto done; 4651 4652 /* 4653 * Run through all PMCs that were targeting the old process 4654 * and which specified F_DESCENDANTS and attach them to the 4655 * new process. 4656 * 4657 * Log the fork event to all owners of PMCs attached to this 4658 * process, if not already logged. 4659 */ 4660 for (ri = 0; ri < md->pmd_npmc; ri++) 4661 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL && 4662 (pm->pm_flags & PMC_F_DESCENDANTS)) { 4663 pmc_link_target_process(pm, ppnew); 4664 po = pm->pm_owner; 4665 if (po->po_sscount == 0 && 4666 po->po_flags & PMC_PO_OWNS_LOGFILE) 4667 pmclog_process_procfork(po, p1->p_pid, 4668 newproc->p_pid); 4669 } 4670 4671 /* 4672 * Now mark the new process as being tracked by this driver. 4673 */ 4674 PROC_LOCK(newproc); 4675 newproc->p_flag |= P_HWPMC; 4676 PROC_UNLOCK(newproc); 4677 4678 done: 4679 sx_xunlock(&pmc_sx); 4680 } 4681 4682 static void 4683 pmc_kld_load(void *arg __unused, linker_file_t lf) 4684 { 4685 struct pmc_owner *po; 4686 4687 sx_slock(&pmc_sx); 4688 4689 /* 4690 * Notify owners of system sampling PMCs about KLD operations. 4691 */ 4692 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 4693 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 4694 pmclog_process_map_in(po, (pid_t) -1, 4695 (uintfptr_t) lf->address, lf->filename); 4696 4697 /* 4698 * TODO: Notify owners of (all) process-sampling PMCs too. 4699 */ 4700 4701 sx_sunlock(&pmc_sx); 4702 } 4703 4704 static void 4705 pmc_kld_unload(void *arg __unused, const char *filename __unused, 4706 caddr_t address, size_t size) 4707 { 4708 struct pmc_owner *po; 4709 4710 sx_slock(&pmc_sx); 4711 4712 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 4713 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 4714 pmclog_process_map_out(po, (pid_t) -1, 4715 (uintfptr_t) address, (uintfptr_t) address + size); 4716 4717 /* 4718 * TODO: Notify owners of process-sampling PMCs. 4719 */ 4720 4721 sx_sunlock(&pmc_sx); 4722 } 4723 4724 /* 4725 * initialization 4726 */ 4727 static const char * 4728 pmc_name_of_pmcclass(enum pmc_class class) 4729 { 4730 4731 switch (class) { 4732 #undef __PMC_CLASS 4733 #define __PMC_CLASS(S,V,D) \ 4734 case PMC_CLASS_##S: \ 4735 return #S; 4736 __PMC_CLASSES(); 4737 default: 4738 return ("<unknown>"); 4739 } 4740 } 4741 4742 /* 4743 * Base class initializer: allocate structure and set default classes. 4744 */ 4745 struct pmc_mdep * 4746 pmc_mdep_alloc(int nclasses) 4747 { 4748 struct pmc_mdep *md; 4749 int n; 4750 4751 /* SOFT + md classes */ 4752 n = 1 + nclasses; 4753 md = malloc(sizeof(struct pmc_mdep) + n * 4754 sizeof(struct pmc_classdep), M_PMC, M_WAITOK|M_ZERO); 4755 md->pmd_nclass = n; 4756 4757 /* Add base class. */ 4758 pmc_soft_initialize(md); 4759 return md; 4760 } 4761 4762 void 4763 pmc_mdep_free(struct pmc_mdep *md) 4764 { 4765 pmc_soft_finalize(md); 4766 free(md, M_PMC); 4767 } 4768 4769 static int 4770 generic_switch_in(struct pmc_cpu *pc, struct pmc_process *pp) 4771 { 4772 (void) pc; (void) pp; 4773 4774 return (0); 4775 } 4776 4777 static int 4778 generic_switch_out(struct pmc_cpu *pc, struct pmc_process *pp) 4779 { 4780 (void) pc; (void) pp; 4781 4782 return (0); 4783 } 4784 4785 static struct pmc_mdep * 4786 pmc_generic_cpu_initialize(void) 4787 { 4788 struct pmc_mdep *md; 4789 4790 md = pmc_mdep_alloc(0); 4791 4792 md->pmd_cputype = PMC_CPU_GENERIC; 4793 4794 md->pmd_pcpu_init = NULL; 4795 md->pmd_pcpu_fini = NULL; 4796 md->pmd_switch_in = generic_switch_in; 4797 md->pmd_switch_out = generic_switch_out; 4798 4799 return (md); 4800 } 4801 4802 static void 4803 pmc_generic_cpu_finalize(struct pmc_mdep *md) 4804 { 4805 (void) md; 4806 } 4807 4808 4809 static int 4810 pmc_initialize(void) 4811 { 4812 int c, cpu, error, n, ri; 4813 unsigned int maxcpu; 4814 struct pmc_binding pb; 4815 struct pmc_sample *ps; 4816 struct pmc_classdep *pcd; 4817 struct pmc_samplebuffer *sb; 4818 4819 md = NULL; 4820 error = 0; 4821 4822 #ifdef HWPMC_DEBUG 4823 /* parse debug flags first */ 4824 if (TUNABLE_STR_FETCH(PMC_SYSCTL_NAME_PREFIX "debugflags", 4825 pmc_debugstr, sizeof(pmc_debugstr))) 4826 pmc_debugflags_parse(pmc_debugstr, 4827 pmc_debugstr+strlen(pmc_debugstr)); 4828 #endif 4829 4830 PMCDBG1(MOD,INI,0, "PMC Initialize (version %x)", PMC_VERSION); 4831 4832 /* check kernel version */ 4833 if (pmc_kernel_version != PMC_VERSION) { 4834 if (pmc_kernel_version == 0) 4835 printf("hwpmc: this kernel has not been compiled with " 4836 "'options HWPMC_HOOKS'.\n"); 4837 else 4838 printf("hwpmc: kernel version (0x%x) does not match " 4839 "module version (0x%x).\n", pmc_kernel_version, 4840 PMC_VERSION); 4841 return EPROGMISMATCH; 4842 } 4843 4844 /* 4845 * check sysctl parameters 4846 */ 4847 4848 if (pmc_hashsize <= 0) { 4849 (void) printf("hwpmc: tunable \"hashsize\"=%d must be " 4850 "greater than zero.\n", pmc_hashsize); 4851 pmc_hashsize = PMC_HASH_SIZE; 4852 } 4853 4854 if (pmc_nsamples <= 0 || pmc_nsamples > 65535) { 4855 (void) printf("hwpmc: tunable \"nsamples\"=%d out of " 4856 "range.\n", pmc_nsamples); 4857 pmc_nsamples = PMC_NSAMPLES; 4858 } 4859 4860 if (pmc_callchaindepth <= 0 || 4861 pmc_callchaindepth > PMC_CALLCHAIN_DEPTH_MAX) { 4862 (void) printf("hwpmc: tunable \"callchaindepth\"=%d out of " 4863 "range - using %d.\n", pmc_callchaindepth, 4864 PMC_CALLCHAIN_DEPTH_MAX); 4865 pmc_callchaindepth = PMC_CALLCHAIN_DEPTH_MAX; 4866 } 4867 4868 md = pmc_md_initialize(); 4869 if (md == NULL) { 4870 /* Default to generic CPU. */ 4871 md = pmc_generic_cpu_initialize(); 4872 if (md == NULL) 4873 return (ENOSYS); 4874 } 4875 4876 KASSERT(md->pmd_nclass >= 1 && md->pmd_npmc >= 1, 4877 ("[pmc,%d] no classes or pmcs", __LINE__)); 4878 4879 /* Compute the map from row-indices to classdep pointers. */ 4880 pmc_rowindex_to_classdep = malloc(sizeof(struct pmc_classdep *) * 4881 md->pmd_npmc, M_PMC, M_WAITOK|M_ZERO); 4882 4883 for (n = 0; n < md->pmd_npmc; n++) 4884 pmc_rowindex_to_classdep[n] = NULL; 4885 for (ri = c = 0; c < md->pmd_nclass; c++) { 4886 pcd = &md->pmd_classdep[c]; 4887 for (n = 0; n < pcd->pcd_num; n++, ri++) 4888 pmc_rowindex_to_classdep[ri] = pcd; 4889 } 4890 4891 KASSERT(ri == md->pmd_npmc, 4892 ("[pmc,%d] npmc miscomputed: ri=%d, md->npmc=%d", __LINE__, 4893 ri, md->pmd_npmc)); 4894 4895 maxcpu = pmc_cpu_max(); 4896 4897 /* allocate space for the per-cpu array */ 4898 pmc_pcpu = malloc(maxcpu * sizeof(struct pmc_cpu *), M_PMC, 4899 M_WAITOK|M_ZERO); 4900 4901 /* per-cpu 'saved values' for managing process-mode PMCs */ 4902 pmc_pcpu_saved = malloc(sizeof(pmc_value_t) * maxcpu * md->pmd_npmc, 4903 M_PMC, M_WAITOK); 4904 4905 /* Perform CPU-dependent initialization. */ 4906 pmc_save_cpu_binding(&pb); 4907 error = 0; 4908 for (cpu = 0; error == 0 && cpu < maxcpu; cpu++) { 4909 if (!pmc_cpu_is_active(cpu)) 4910 continue; 4911 pmc_select_cpu(cpu); 4912 pmc_pcpu[cpu] = malloc(sizeof(struct pmc_cpu) + 4913 md->pmd_npmc * sizeof(struct pmc_hw *), M_PMC, 4914 M_WAITOK|M_ZERO); 4915 if (md->pmd_pcpu_init) 4916 error = md->pmd_pcpu_init(md, cpu); 4917 for (n = 0; error == 0 && n < md->pmd_nclass; n++) 4918 error = md->pmd_classdep[n].pcd_pcpu_init(md, cpu); 4919 } 4920 pmc_restore_cpu_binding(&pb); 4921 4922 if (error) 4923 return (error); 4924 4925 /* allocate space for the sample array */ 4926 for (cpu = 0; cpu < maxcpu; cpu++) { 4927 if (!pmc_cpu_is_active(cpu)) 4928 continue; 4929 4930 sb = malloc(sizeof(struct pmc_samplebuffer) + 4931 pmc_nsamples * sizeof(struct pmc_sample), M_PMC, 4932 M_WAITOK|M_ZERO); 4933 sb->ps_read = sb->ps_write = sb->ps_samples; 4934 sb->ps_fence = sb->ps_samples + pmc_nsamples; 4935 4936 KASSERT(pmc_pcpu[cpu] != NULL, 4937 ("[pmc,%d] cpu=%d Null per-cpu data", __LINE__, cpu)); 4938 4939 sb->ps_callchains = malloc(pmc_callchaindepth * pmc_nsamples * 4940 sizeof(uintptr_t), M_PMC, M_WAITOK|M_ZERO); 4941 4942 for (n = 0, ps = sb->ps_samples; n < pmc_nsamples; n++, ps++) 4943 ps->ps_pc = sb->ps_callchains + 4944 (n * pmc_callchaindepth); 4945 4946 pmc_pcpu[cpu]->pc_sb[PMC_HR] = sb; 4947 4948 sb = malloc(sizeof(struct pmc_samplebuffer) + 4949 pmc_nsamples * sizeof(struct pmc_sample), M_PMC, 4950 M_WAITOK|M_ZERO); 4951 sb->ps_read = sb->ps_write = sb->ps_samples; 4952 sb->ps_fence = sb->ps_samples + pmc_nsamples; 4953 4954 KASSERT(pmc_pcpu[cpu] != NULL, 4955 ("[pmc,%d] cpu=%d Null per-cpu data", __LINE__, cpu)); 4956 4957 sb->ps_callchains = malloc(pmc_callchaindepth * pmc_nsamples * 4958 sizeof(uintptr_t), M_PMC, M_WAITOK|M_ZERO); 4959 4960 for (n = 0, ps = sb->ps_samples; n < pmc_nsamples; n++, ps++) 4961 ps->ps_pc = sb->ps_callchains + 4962 (n * pmc_callchaindepth); 4963 4964 pmc_pcpu[cpu]->pc_sb[PMC_SR] = sb; 4965 } 4966 4967 /* allocate space for the row disposition array */ 4968 pmc_pmcdisp = malloc(sizeof(enum pmc_mode) * md->pmd_npmc, 4969 M_PMC, M_WAITOK|M_ZERO); 4970 4971 /* mark all PMCs as available */ 4972 for (n = 0; n < (int) md->pmd_npmc; n++) 4973 PMC_MARK_ROW_FREE(n); 4974 4975 /* allocate thread hash tables */ 4976 pmc_ownerhash = hashinit(pmc_hashsize, M_PMC, 4977 &pmc_ownerhashmask); 4978 4979 pmc_processhash = hashinit(pmc_hashsize, M_PMC, 4980 &pmc_processhashmask); 4981 mtx_init(&pmc_processhash_mtx, "pmc-process-hash", "pmc-leaf", 4982 MTX_SPIN); 4983 4984 LIST_INIT(&pmc_ss_owners); 4985 pmc_ss_count = 0; 4986 4987 /* allocate a pool of spin mutexes */ 4988 pmc_mtxpool = mtx_pool_create("pmc-leaf", pmc_mtxpool_size, 4989 MTX_SPIN); 4990 4991 PMCDBG4(MOD,INI,1, "pmc_ownerhash=%p, mask=0x%lx " 4992 "targethash=%p mask=0x%lx", pmc_ownerhash, pmc_ownerhashmask, 4993 pmc_processhash, pmc_processhashmask); 4994 4995 /* register process {exit,fork,exec} handlers */ 4996 pmc_exit_tag = EVENTHANDLER_REGISTER(process_exit, 4997 pmc_process_exit, NULL, EVENTHANDLER_PRI_ANY); 4998 pmc_fork_tag = EVENTHANDLER_REGISTER(process_fork, 4999 pmc_process_fork, NULL, EVENTHANDLER_PRI_ANY); 5000 5001 /* register kld event handlers */ 5002 pmc_kld_load_tag = EVENTHANDLER_REGISTER(kld_load, pmc_kld_load, 5003 NULL, EVENTHANDLER_PRI_ANY); 5004 pmc_kld_unload_tag = EVENTHANDLER_REGISTER(kld_unload, pmc_kld_unload, 5005 NULL, EVENTHANDLER_PRI_ANY); 5006 5007 /* initialize logging */ 5008 pmclog_initialize(); 5009 5010 /* set hook functions */ 5011 pmc_intr = md->pmd_intr; 5012 pmc_hook = pmc_hook_handler; 5013 5014 if (error == 0) { 5015 printf(PMC_MODULE_NAME ":"); 5016 for (n = 0; n < (int) md->pmd_nclass; n++) { 5017 pcd = &md->pmd_classdep[n]; 5018 printf(" %s/%d/%d/0x%b", 5019 pmc_name_of_pmcclass(pcd->pcd_class), 5020 pcd->pcd_num, 5021 pcd->pcd_width, 5022 pcd->pcd_caps, 5023 "\20" 5024 "\1INT\2USR\3SYS\4EDG\5THR" 5025 "\6REA\7WRI\10INV\11QUA\12PRC" 5026 "\13TAG\14CSC"); 5027 } 5028 printf("\n"); 5029 } 5030 5031 return (error); 5032 } 5033 5034 /* prepare to be unloaded */ 5035 static void 5036 pmc_cleanup(void) 5037 { 5038 int c, cpu; 5039 unsigned int maxcpu; 5040 struct pmc_ownerhash *ph; 5041 struct pmc_owner *po, *tmp; 5042 struct pmc_binding pb; 5043 #ifdef HWPMC_DEBUG 5044 struct pmc_processhash *prh; 5045 #endif 5046 5047 PMCDBG0(MOD,INI,0, "cleanup"); 5048 5049 /* switch off sampling */ 5050 CPU_ZERO(&pmc_cpumask); 5051 pmc_intr = NULL; 5052 5053 sx_xlock(&pmc_sx); 5054 if (pmc_hook == NULL) { /* being unloaded already */ 5055 sx_xunlock(&pmc_sx); 5056 return; 5057 } 5058 5059 pmc_hook = NULL; /* prevent new threads from entering module */ 5060 5061 /* deregister event handlers */ 5062 EVENTHANDLER_DEREGISTER(process_fork, pmc_fork_tag); 5063 EVENTHANDLER_DEREGISTER(process_exit, pmc_exit_tag); 5064 EVENTHANDLER_DEREGISTER(kld_load, pmc_kld_load_tag); 5065 EVENTHANDLER_DEREGISTER(kld_unload, pmc_kld_unload_tag); 5066 5067 /* send SIGBUS to all owner threads, free up allocations */ 5068 if (pmc_ownerhash) 5069 for (ph = pmc_ownerhash; 5070 ph <= &pmc_ownerhash[pmc_ownerhashmask]; 5071 ph++) { 5072 LIST_FOREACH_SAFE(po, ph, po_next, tmp) { 5073 pmc_remove_owner(po); 5074 5075 /* send SIGBUS to owner processes */ 5076 PMCDBG3(MOD,INI,2, "cleanup signal proc=%p " 5077 "(%d, %s)", po->po_owner, 5078 po->po_owner->p_pid, 5079 po->po_owner->p_comm); 5080 5081 PROC_LOCK(po->po_owner); 5082 kern_psignal(po->po_owner, SIGBUS); 5083 PROC_UNLOCK(po->po_owner); 5084 5085 pmc_destroy_owner_descriptor(po); 5086 } 5087 } 5088 5089 /* reclaim allocated data structures */ 5090 if (pmc_mtxpool) 5091 mtx_pool_destroy(&pmc_mtxpool); 5092 5093 mtx_destroy(&pmc_processhash_mtx); 5094 if (pmc_processhash) { 5095 #ifdef HWPMC_DEBUG 5096 struct pmc_process *pp; 5097 5098 PMCDBG0(MOD,INI,3, "destroy process hash"); 5099 for (prh = pmc_processhash; 5100 prh <= &pmc_processhash[pmc_processhashmask]; 5101 prh++) 5102 LIST_FOREACH(pp, prh, pp_next) 5103 PMCDBG1(MOD,INI,3, "pid=%d", pp->pp_proc->p_pid); 5104 #endif 5105 5106 hashdestroy(pmc_processhash, M_PMC, pmc_processhashmask); 5107 pmc_processhash = NULL; 5108 } 5109 5110 if (pmc_ownerhash) { 5111 PMCDBG0(MOD,INI,3, "destroy owner hash"); 5112 hashdestroy(pmc_ownerhash, M_PMC, pmc_ownerhashmask); 5113 pmc_ownerhash = NULL; 5114 } 5115 5116 KASSERT(LIST_EMPTY(&pmc_ss_owners), 5117 ("[pmc,%d] Global SS owner list not empty", __LINE__)); 5118 KASSERT(pmc_ss_count == 0, 5119 ("[pmc,%d] Global SS count not empty", __LINE__)); 5120 5121 /* do processor and pmc-class dependent cleanup */ 5122 maxcpu = pmc_cpu_max(); 5123 5124 PMCDBG0(MOD,INI,3, "md cleanup"); 5125 if (md) { 5126 pmc_save_cpu_binding(&pb); 5127 for (cpu = 0; cpu < maxcpu; cpu++) { 5128 PMCDBG2(MOD,INI,1,"pmc-cleanup cpu=%d pcs=%p", 5129 cpu, pmc_pcpu[cpu]); 5130 if (!pmc_cpu_is_active(cpu) || pmc_pcpu[cpu] == NULL) 5131 continue; 5132 pmc_select_cpu(cpu); 5133 for (c = 0; c < md->pmd_nclass; c++) 5134 md->pmd_classdep[c].pcd_pcpu_fini(md, cpu); 5135 if (md->pmd_pcpu_fini) 5136 md->pmd_pcpu_fini(md, cpu); 5137 } 5138 5139 if (md->pmd_cputype == PMC_CPU_GENERIC) 5140 pmc_generic_cpu_finalize(md); 5141 else 5142 pmc_md_finalize(md); 5143 5144 pmc_mdep_free(md); 5145 md = NULL; 5146 pmc_restore_cpu_binding(&pb); 5147 } 5148 5149 /* Free per-cpu descriptors. */ 5150 for (cpu = 0; cpu < maxcpu; cpu++) { 5151 if (!pmc_cpu_is_active(cpu)) 5152 continue; 5153 KASSERT(pmc_pcpu[cpu]->pc_sb[PMC_HR] != NULL, 5154 ("[pmc,%d] Null hw cpu sample buffer cpu=%d", __LINE__, 5155 cpu)); 5156 KASSERT(pmc_pcpu[cpu]->pc_sb[PMC_SR] != NULL, 5157 ("[pmc,%d] Null sw cpu sample buffer cpu=%d", __LINE__, 5158 cpu)); 5159 free(pmc_pcpu[cpu]->pc_sb[PMC_HR]->ps_callchains, M_PMC); 5160 free(pmc_pcpu[cpu]->pc_sb[PMC_HR], M_PMC); 5161 free(pmc_pcpu[cpu]->pc_sb[PMC_SR]->ps_callchains, M_PMC); 5162 free(pmc_pcpu[cpu]->pc_sb[PMC_SR], M_PMC); 5163 free(pmc_pcpu[cpu], M_PMC); 5164 } 5165 5166 free(pmc_pcpu, M_PMC); 5167 pmc_pcpu = NULL; 5168 5169 free(pmc_pcpu_saved, M_PMC); 5170 pmc_pcpu_saved = NULL; 5171 5172 if (pmc_pmcdisp) { 5173 free(pmc_pmcdisp, M_PMC); 5174 pmc_pmcdisp = NULL; 5175 } 5176 5177 if (pmc_rowindex_to_classdep) { 5178 free(pmc_rowindex_to_classdep, M_PMC); 5179 pmc_rowindex_to_classdep = NULL; 5180 } 5181 5182 pmclog_shutdown(); 5183 5184 sx_xunlock(&pmc_sx); /* we are done */ 5185 } 5186 5187 /* 5188 * The function called at load/unload. 5189 */ 5190 5191 static int 5192 load (struct module *module __unused, int cmd, void *arg __unused) 5193 { 5194 int error; 5195 5196 error = 0; 5197 5198 switch (cmd) { 5199 case MOD_LOAD : 5200 /* initialize the subsystem */ 5201 error = pmc_initialize(); 5202 if (error != 0) 5203 break; 5204 PMCDBG2(MOD,INI,1, "syscall=%d maxcpu=%d", 5205 pmc_syscall_num, pmc_cpu_max()); 5206 break; 5207 5208 5209 case MOD_UNLOAD : 5210 case MOD_SHUTDOWN: 5211 pmc_cleanup(); 5212 PMCDBG0(MOD,INI,1, "unloaded"); 5213 break; 5214 5215 default : 5216 error = EINVAL; /* XXX should panic(9) */ 5217 break; 5218 } 5219 5220 return error; 5221 } 5222 5223 /* memory pool */ 5224 MALLOC_DEFINE(M_PMC, "pmc", "Memory space for the PMC module"); 5225