1 /*- 2 * Copyright (c) 2003-2008 Joseph Koshy 3 * Copyright (c) 2007 The FreeBSD Foundation 4 * All rights reserved. 5 * 6 * Portions of this software were developed by A. Joseph Koshy under 7 * sponsorship from the FreeBSD Foundation and Google, Inc. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 * 30 */ 31 32 #include <sys/cdefs.h> 33 __FBSDID("$FreeBSD$"); 34 35 #include <sys/param.h> 36 #include <sys/eventhandler.h> 37 #include <sys/jail.h> 38 #include <sys/kernel.h> 39 #include <sys/kthread.h> 40 #include <sys/limits.h> 41 #include <sys/lock.h> 42 #include <sys/malloc.h> 43 #include <sys/module.h> 44 #include <sys/mount.h> 45 #include <sys/mutex.h> 46 #include <sys/pmc.h> 47 #include <sys/pmckern.h> 48 #include <sys/pmclog.h> 49 #include <sys/priv.h> 50 #include <sys/proc.h> 51 #include <sys/queue.h> 52 #include <sys/resourcevar.h> 53 #include <sys/rwlock.h> 54 #include <sys/sched.h> 55 #include <sys/signalvar.h> 56 #include <sys/smp.h> 57 #include <sys/sx.h> 58 #include <sys/sysctl.h> 59 #include <sys/sysent.h> 60 #include <sys/systm.h> 61 #include <sys/vnode.h> 62 63 #include <sys/linker.h> /* needs to be after <sys/malloc.h> */ 64 65 #include <machine/atomic.h> 66 #include <machine/md_var.h> 67 68 #include <vm/vm.h> 69 #include <vm/vm_extern.h> 70 #include <vm/pmap.h> 71 #include <vm/vm_map.h> 72 #include <vm/vm_object.h> 73 74 #include "hwpmc_soft.h" 75 76 /* 77 * Types 78 */ 79 80 enum pmc_flags { 81 PMC_FLAG_NONE = 0x00, /* do nothing */ 82 PMC_FLAG_REMOVE = 0x01, /* atomically remove entry from hash */ 83 PMC_FLAG_ALLOCATE = 0x02, /* add entry to hash if not found */ 84 }; 85 86 /* 87 * The offset in sysent where the syscall is allocated. 88 */ 89 90 static int pmc_syscall_num = NO_SYSCALL; 91 struct pmc_cpu **pmc_pcpu; /* per-cpu state */ 92 pmc_value_t *pmc_pcpu_saved; /* saved PMC values: CSW handling */ 93 94 #define PMC_PCPU_SAVED(C,R) pmc_pcpu_saved[(R) + md->pmd_npmc*(C)] 95 96 struct mtx_pool *pmc_mtxpool; 97 static int *pmc_pmcdisp; /* PMC row dispositions */ 98 99 #define PMC_ROW_DISP_IS_FREE(R) (pmc_pmcdisp[(R)] == 0) 100 #define PMC_ROW_DISP_IS_THREAD(R) (pmc_pmcdisp[(R)] > 0) 101 #define PMC_ROW_DISP_IS_STANDALONE(R) (pmc_pmcdisp[(R)] < 0) 102 103 #define PMC_MARK_ROW_FREE(R) do { \ 104 pmc_pmcdisp[(R)] = 0; \ 105 } while (0) 106 107 #define PMC_MARK_ROW_STANDALONE(R) do { \ 108 KASSERT(pmc_pmcdisp[(R)] <= 0, ("[pmc,%d] row disposition error", \ 109 __LINE__)); \ 110 atomic_add_int(&pmc_pmcdisp[(R)], -1); \ 111 KASSERT(pmc_pmcdisp[(R)] >= (-pmc_cpu_max_active()), \ 112 ("[pmc,%d] row disposition error", __LINE__)); \ 113 } while (0) 114 115 #define PMC_UNMARK_ROW_STANDALONE(R) do { \ 116 atomic_add_int(&pmc_pmcdisp[(R)], 1); \ 117 KASSERT(pmc_pmcdisp[(R)] <= 0, ("[pmc,%d] row disposition error", \ 118 __LINE__)); \ 119 } while (0) 120 121 #define PMC_MARK_ROW_THREAD(R) do { \ 122 KASSERT(pmc_pmcdisp[(R)] >= 0, ("[pmc,%d] row disposition error", \ 123 __LINE__)); \ 124 atomic_add_int(&pmc_pmcdisp[(R)], 1); \ 125 } while (0) 126 127 #define PMC_UNMARK_ROW_THREAD(R) do { \ 128 atomic_add_int(&pmc_pmcdisp[(R)], -1); \ 129 KASSERT(pmc_pmcdisp[(R)] >= 0, ("[pmc,%d] row disposition error", \ 130 __LINE__)); \ 131 } while (0) 132 133 134 /* various event handlers */ 135 static eventhandler_tag pmc_exit_tag, pmc_fork_tag, pmc_kld_load_tag, 136 pmc_kld_unload_tag; 137 138 /* Module statistics */ 139 struct pmc_op_getdriverstats pmc_stats; 140 141 /* Machine/processor dependent operations */ 142 static struct pmc_mdep *md; 143 144 /* 145 * Hash tables mapping owner processes and target threads to PMCs. 146 */ 147 148 struct mtx pmc_processhash_mtx; /* spin mutex */ 149 static u_long pmc_processhashmask; 150 static LIST_HEAD(pmc_processhash, pmc_process) *pmc_processhash; 151 152 /* 153 * Hash table of PMC owner descriptors. This table is protected by 154 * the shared PMC "sx" lock. 155 */ 156 157 static u_long pmc_ownerhashmask; 158 static LIST_HEAD(pmc_ownerhash, pmc_owner) *pmc_ownerhash; 159 160 /* 161 * List of PMC owners with system-wide sampling PMCs. 162 */ 163 164 static LIST_HEAD(, pmc_owner) pmc_ss_owners; 165 166 167 /* 168 * A map of row indices to classdep structures. 169 */ 170 static struct pmc_classdep **pmc_rowindex_to_classdep; 171 172 /* 173 * Prototypes 174 */ 175 176 #ifdef HWPMC_DEBUG 177 static int pmc_debugflags_sysctl_handler(SYSCTL_HANDLER_ARGS); 178 static int pmc_debugflags_parse(char *newstr, char *fence); 179 #endif 180 181 static int load(struct module *module, int cmd, void *arg); 182 static int pmc_attach_process(struct proc *p, struct pmc *pm); 183 static struct pmc *pmc_allocate_pmc_descriptor(void); 184 static struct pmc_owner *pmc_allocate_owner_descriptor(struct proc *p); 185 static int pmc_attach_one_process(struct proc *p, struct pmc *pm); 186 static int pmc_can_allocate_rowindex(struct proc *p, unsigned int ri, 187 int cpu); 188 static int pmc_can_attach(struct pmc *pm, struct proc *p); 189 static void pmc_capture_user_callchain(int cpu, int soft, struct trapframe *tf); 190 static void pmc_cleanup(void); 191 static int pmc_detach_process(struct proc *p, struct pmc *pm); 192 static int pmc_detach_one_process(struct proc *p, struct pmc *pm, 193 int flags); 194 static void pmc_destroy_owner_descriptor(struct pmc_owner *po); 195 static void pmc_destroy_pmc_descriptor(struct pmc *pm); 196 static struct pmc_owner *pmc_find_owner_descriptor(struct proc *p); 197 static int pmc_find_pmc(pmc_id_t pmcid, struct pmc **pm); 198 static struct pmc *pmc_find_pmc_descriptor_in_process(struct pmc_owner *po, 199 pmc_id_t pmc); 200 static struct pmc_process *pmc_find_process_descriptor(struct proc *p, 201 uint32_t mode); 202 static void pmc_force_context_switch(void); 203 static void pmc_link_target_process(struct pmc *pm, 204 struct pmc_process *pp); 205 static void pmc_log_all_process_mappings(struct pmc_owner *po); 206 static void pmc_log_kernel_mappings(struct pmc *pm); 207 static void pmc_log_process_mappings(struct pmc_owner *po, struct proc *p); 208 static void pmc_maybe_remove_owner(struct pmc_owner *po); 209 static void pmc_process_csw_in(struct thread *td); 210 static void pmc_process_csw_out(struct thread *td); 211 static void pmc_process_exit(void *arg, struct proc *p); 212 static void pmc_process_fork(void *arg, struct proc *p1, 213 struct proc *p2, int n); 214 static void pmc_process_samples(int cpu, int soft); 215 static void pmc_release_pmc_descriptor(struct pmc *pmc); 216 static void pmc_remove_owner(struct pmc_owner *po); 217 static void pmc_remove_process_descriptor(struct pmc_process *pp); 218 static void pmc_restore_cpu_binding(struct pmc_binding *pb); 219 static void pmc_save_cpu_binding(struct pmc_binding *pb); 220 static void pmc_select_cpu(int cpu); 221 static int pmc_start(struct pmc *pm); 222 static int pmc_stop(struct pmc *pm); 223 static int pmc_syscall_handler(struct thread *td, void *syscall_args); 224 static void pmc_unlink_target_process(struct pmc *pmc, 225 struct pmc_process *pp); 226 static int generic_switch_in(struct pmc_cpu *pc, struct pmc_process *pp); 227 static int generic_switch_out(struct pmc_cpu *pc, struct pmc_process *pp); 228 static struct pmc_mdep *pmc_generic_cpu_initialize(void); 229 static void pmc_generic_cpu_finalize(struct pmc_mdep *md); 230 231 /* 232 * Kernel tunables and sysctl(8) interface. 233 */ 234 235 SYSCTL_DECL(_kern_hwpmc); 236 237 static int pmc_callchaindepth = PMC_CALLCHAIN_DEPTH; 238 SYSCTL_INT(_kern_hwpmc, OID_AUTO, callchaindepth, CTLFLAG_RDTUN, 239 &pmc_callchaindepth, 0, "depth of call chain records"); 240 241 #ifdef HWPMC_DEBUG 242 struct pmc_debugflags pmc_debugflags = PMC_DEBUG_DEFAULT_FLAGS; 243 char pmc_debugstr[PMC_DEBUG_STRSIZE]; 244 TUNABLE_STR(PMC_SYSCTL_NAME_PREFIX "debugflags", pmc_debugstr, 245 sizeof(pmc_debugstr)); 246 SYSCTL_PROC(_kern_hwpmc, OID_AUTO, debugflags, 247 CTLTYPE_STRING | CTLFLAG_RWTUN | CTLFLAG_NOFETCH, 248 0, 0, pmc_debugflags_sysctl_handler, "A", "debug flags"); 249 #endif 250 251 /* 252 * kern.hwpmc.hashrows -- determines the number of rows in the 253 * of the hash table used to look up threads 254 */ 255 256 static int pmc_hashsize = PMC_HASH_SIZE; 257 SYSCTL_INT(_kern_hwpmc, OID_AUTO, hashsize, CTLFLAG_RDTUN, 258 &pmc_hashsize, 0, "rows in hash tables"); 259 260 /* 261 * kern.hwpmc.nsamples --- number of PC samples/callchain stacks per CPU 262 */ 263 264 static int pmc_nsamples = PMC_NSAMPLES; 265 SYSCTL_INT(_kern_hwpmc, OID_AUTO, nsamples, CTLFLAG_RDTUN, 266 &pmc_nsamples, 0, "number of PC samples per CPU"); 267 268 269 /* 270 * kern.hwpmc.mtxpoolsize -- number of mutexes in the mutex pool. 271 */ 272 273 static int pmc_mtxpool_size = PMC_MTXPOOL_SIZE; 274 SYSCTL_INT(_kern_hwpmc, OID_AUTO, mtxpoolsize, CTLFLAG_RDTUN, 275 &pmc_mtxpool_size, 0, "size of spin mutex pool"); 276 277 278 /* 279 * security.bsd.unprivileged_syspmcs -- allow non-root processes to 280 * allocate system-wide PMCs. 281 * 282 * Allowing unprivileged processes to allocate system PMCs is convenient 283 * if system-wide measurements need to be taken concurrently with other 284 * per-process measurements. This feature is turned off by default. 285 */ 286 287 static int pmc_unprivileged_syspmcs = 0; 288 SYSCTL_INT(_security_bsd, OID_AUTO, unprivileged_syspmcs, CTLFLAG_RWTUN, 289 &pmc_unprivileged_syspmcs, 0, 290 "allow unprivileged process to allocate system PMCs"); 291 292 /* 293 * Hash function. Discard the lower 2 bits of the pointer since 294 * these are always zero for our uses. The hash multiplier is 295 * round((2^LONG_BIT) * ((sqrt(5)-1)/2)). 296 */ 297 298 #if LONG_BIT == 64 299 #define _PMC_HM 11400714819323198486u 300 #elif LONG_BIT == 32 301 #define _PMC_HM 2654435769u 302 #else 303 #error Must know the size of 'long' to compile 304 #endif 305 306 #define PMC_HASH_PTR(P,M) ((((unsigned long) (P) >> 2) * _PMC_HM) & (M)) 307 308 /* 309 * Syscall structures 310 */ 311 312 /* The `sysent' for the new syscall */ 313 static struct sysent pmc_sysent = { 314 2, /* sy_narg */ 315 pmc_syscall_handler /* sy_call */ 316 }; 317 318 static struct syscall_module_data pmc_syscall_mod = { 319 load, 320 NULL, 321 &pmc_syscall_num, 322 &pmc_sysent, 323 #if (__FreeBSD_version >= 1100000) 324 { 0, NULL }, 325 SY_THR_STATIC_KLD, 326 #else 327 { 0, NULL } 328 #endif 329 }; 330 331 static moduledata_t pmc_mod = { 332 PMC_MODULE_NAME, 333 syscall_module_handler, 334 &pmc_syscall_mod 335 }; 336 337 DECLARE_MODULE(pmc, pmc_mod, SI_SUB_SMP, SI_ORDER_ANY); 338 MODULE_VERSION(pmc, PMC_VERSION); 339 340 #ifdef HWPMC_DEBUG 341 enum pmc_dbgparse_state { 342 PMCDS_WS, /* in whitespace */ 343 PMCDS_MAJOR, /* seen a major keyword */ 344 PMCDS_MINOR 345 }; 346 347 static int 348 pmc_debugflags_parse(char *newstr, char *fence) 349 { 350 char c, *p, *q; 351 struct pmc_debugflags *tmpflags; 352 int error, found, *newbits, tmp; 353 size_t kwlen; 354 355 tmpflags = malloc(sizeof(*tmpflags), M_PMC, M_WAITOK|M_ZERO); 356 357 p = newstr; 358 error = 0; 359 360 for (; p < fence && (c = *p); p++) { 361 362 /* skip white space */ 363 if (c == ' ' || c == '\t') 364 continue; 365 366 /* look for a keyword followed by "=" */ 367 for (q = p; p < fence && (c = *p) && c != '='; p++) 368 ; 369 if (c != '=') { 370 error = EINVAL; 371 goto done; 372 } 373 374 kwlen = p - q; 375 newbits = NULL; 376 377 /* lookup flag group name */ 378 #define DBG_SET_FLAG_MAJ(S,F) \ 379 if (kwlen == sizeof(S)-1 && strncmp(q, S, kwlen) == 0) \ 380 newbits = &tmpflags->pdb_ ## F; 381 382 DBG_SET_FLAG_MAJ("cpu", CPU); 383 DBG_SET_FLAG_MAJ("csw", CSW); 384 DBG_SET_FLAG_MAJ("logging", LOG); 385 DBG_SET_FLAG_MAJ("module", MOD); 386 DBG_SET_FLAG_MAJ("md", MDP); 387 DBG_SET_FLAG_MAJ("owner", OWN); 388 DBG_SET_FLAG_MAJ("pmc", PMC); 389 DBG_SET_FLAG_MAJ("process", PRC); 390 DBG_SET_FLAG_MAJ("sampling", SAM); 391 392 if (newbits == NULL) { 393 error = EINVAL; 394 goto done; 395 } 396 397 p++; /* skip the '=' */ 398 399 /* Now parse the individual flags */ 400 tmp = 0; 401 newflag: 402 for (q = p; p < fence && (c = *p); p++) 403 if (c == ' ' || c == '\t' || c == ',') 404 break; 405 406 /* p == fence or c == ws or c == "," or c == 0 */ 407 408 if ((kwlen = p - q) == 0) { 409 *newbits = tmp; 410 continue; 411 } 412 413 found = 0; 414 #define DBG_SET_FLAG_MIN(S,F) \ 415 if (kwlen == sizeof(S)-1 && strncmp(q, S, kwlen) == 0) \ 416 tmp |= found = (1 << PMC_DEBUG_MIN_ ## F) 417 418 /* a '*' denotes all possible flags in the group */ 419 if (kwlen == 1 && *q == '*') 420 tmp = found = ~0; 421 /* look for individual flag names */ 422 DBG_SET_FLAG_MIN("allocaterow", ALR); 423 DBG_SET_FLAG_MIN("allocate", ALL); 424 DBG_SET_FLAG_MIN("attach", ATT); 425 DBG_SET_FLAG_MIN("bind", BND); 426 DBG_SET_FLAG_MIN("config", CFG); 427 DBG_SET_FLAG_MIN("exec", EXC); 428 DBG_SET_FLAG_MIN("exit", EXT); 429 DBG_SET_FLAG_MIN("find", FND); 430 DBG_SET_FLAG_MIN("flush", FLS); 431 DBG_SET_FLAG_MIN("fork", FRK); 432 DBG_SET_FLAG_MIN("getbuf", GTB); 433 DBG_SET_FLAG_MIN("hook", PMH); 434 DBG_SET_FLAG_MIN("init", INI); 435 DBG_SET_FLAG_MIN("intr", INT); 436 DBG_SET_FLAG_MIN("linktarget", TLK); 437 DBG_SET_FLAG_MIN("mayberemove", OMR); 438 DBG_SET_FLAG_MIN("ops", OPS); 439 DBG_SET_FLAG_MIN("read", REA); 440 DBG_SET_FLAG_MIN("register", REG); 441 DBG_SET_FLAG_MIN("release", REL); 442 DBG_SET_FLAG_MIN("remove", ORM); 443 DBG_SET_FLAG_MIN("sample", SAM); 444 DBG_SET_FLAG_MIN("scheduleio", SIO); 445 DBG_SET_FLAG_MIN("select", SEL); 446 DBG_SET_FLAG_MIN("signal", SIG); 447 DBG_SET_FLAG_MIN("swi", SWI); 448 DBG_SET_FLAG_MIN("swo", SWO); 449 DBG_SET_FLAG_MIN("start", STA); 450 DBG_SET_FLAG_MIN("stop", STO); 451 DBG_SET_FLAG_MIN("syscall", PMS); 452 DBG_SET_FLAG_MIN("unlinktarget", TUL); 453 DBG_SET_FLAG_MIN("write", WRI); 454 if (found == 0) { 455 /* unrecognized flag name */ 456 error = EINVAL; 457 goto done; 458 } 459 460 if (c == 0 || c == ' ' || c == '\t') { /* end of flag group */ 461 *newbits = tmp; 462 continue; 463 } 464 465 p++; 466 goto newflag; 467 } 468 469 /* save the new flag set */ 470 bcopy(tmpflags, &pmc_debugflags, sizeof(pmc_debugflags)); 471 472 done: 473 free(tmpflags, M_PMC); 474 return error; 475 } 476 477 static int 478 pmc_debugflags_sysctl_handler(SYSCTL_HANDLER_ARGS) 479 { 480 char *fence, *newstr; 481 int error; 482 unsigned int n; 483 484 (void) arg1; (void) arg2; /* unused parameters */ 485 486 n = sizeof(pmc_debugstr); 487 newstr = malloc(n, M_PMC, M_WAITOK|M_ZERO); 488 (void) strlcpy(newstr, pmc_debugstr, n); 489 490 error = sysctl_handle_string(oidp, newstr, n, req); 491 492 /* if there is a new string, parse and copy it */ 493 if (error == 0 && req->newptr != NULL) { 494 fence = newstr + (n < req->newlen ? n : req->newlen + 1); 495 if ((error = pmc_debugflags_parse(newstr, fence)) == 0) 496 (void) strlcpy(pmc_debugstr, newstr, 497 sizeof(pmc_debugstr)); 498 } 499 500 free(newstr, M_PMC); 501 502 return error; 503 } 504 #endif 505 506 /* 507 * Map a row index to a classdep structure and return the adjusted row 508 * index for the PMC class index. 509 */ 510 static struct pmc_classdep * 511 pmc_ri_to_classdep(struct pmc_mdep *md, int ri, int *adjri) 512 { 513 struct pmc_classdep *pcd; 514 515 (void) md; 516 517 KASSERT(ri >= 0 && ri < md->pmd_npmc, 518 ("[pmc,%d] illegal row-index %d", __LINE__, ri)); 519 520 pcd = pmc_rowindex_to_classdep[ri]; 521 522 KASSERT(pcd != NULL, 523 ("[pmc,%d] ri %d null pcd", __LINE__, ri)); 524 525 *adjri = ri - pcd->pcd_ri; 526 527 KASSERT(*adjri >= 0 && *adjri < pcd->pcd_num, 528 ("[pmc,%d] adjusted row-index %d", __LINE__, *adjri)); 529 530 return (pcd); 531 } 532 533 /* 534 * Concurrency Control 535 * 536 * The driver manages the following data structures: 537 * 538 * - target process descriptors, one per target process 539 * - owner process descriptors (and attached lists), one per owner process 540 * - lookup hash tables for owner and target processes 541 * - PMC descriptors (and attached lists) 542 * - per-cpu hardware state 543 * - the 'hook' variable through which the kernel calls into 544 * this module 545 * - the machine hardware state (managed by the MD layer) 546 * 547 * These data structures are accessed from: 548 * 549 * - thread context-switch code 550 * - interrupt handlers (possibly on multiple cpus) 551 * - kernel threads on multiple cpus running on behalf of user 552 * processes doing system calls 553 * - this driver's private kernel threads 554 * 555 * = Locks and Locking strategy = 556 * 557 * The driver uses four locking strategies for its operation: 558 * 559 * - The global SX lock "pmc_sx" is used to protect internal 560 * data structures. 561 * 562 * Calls into the module by syscall() start with this lock being 563 * held in exclusive mode. Depending on the requested operation, 564 * the lock may be downgraded to 'shared' mode to allow more 565 * concurrent readers into the module. Calls into the module from 566 * other parts of the kernel acquire the lock in shared mode. 567 * 568 * This SX lock is held in exclusive mode for any operations that 569 * modify the linkages between the driver's internal data structures. 570 * 571 * The 'pmc_hook' function pointer is also protected by this lock. 572 * It is only examined with the sx lock held in exclusive mode. The 573 * kernel module is allowed to be unloaded only with the sx lock held 574 * in exclusive mode. In normal syscall handling, after acquiring the 575 * pmc_sx lock we first check that 'pmc_hook' is non-null before 576 * proceeding. This prevents races between the thread unloading the module 577 * and other threads seeking to use the module. 578 * 579 * - Lookups of target process structures and owner process structures 580 * cannot use the global "pmc_sx" SX lock because these lookups need 581 * to happen during context switches and in other critical sections 582 * where sleeping is not allowed. We protect these lookup tables 583 * with their own private spin-mutexes, "pmc_processhash_mtx" and 584 * "pmc_ownerhash_mtx". 585 * 586 * - Interrupt handlers work in a lock free manner. At interrupt 587 * time, handlers look at the PMC pointer (phw->phw_pmc) configured 588 * when the PMC was started. If this pointer is NULL, the interrupt 589 * is ignored after updating driver statistics. We ensure that this 590 * pointer is set (using an atomic operation if necessary) before the 591 * PMC hardware is started. Conversely, this pointer is unset atomically 592 * only after the PMC hardware is stopped. 593 * 594 * We ensure that everything needed for the operation of an 595 * interrupt handler is available without it needing to acquire any 596 * locks. We also ensure that a PMC's software state is destroyed only 597 * after the PMC is taken off hardware (on all CPUs). 598 * 599 * - Context-switch handling with process-private PMCs needs more 600 * care. 601 * 602 * A given process may be the target of multiple PMCs. For example, 603 * PMCATTACH and PMCDETACH may be requested by a process on one CPU 604 * while the target process is running on another. A PMC could also 605 * be getting released because its owner is exiting. We tackle 606 * these situations in the following manner: 607 * 608 * - each target process structure 'pmc_process' has an array 609 * of 'struct pmc *' pointers, one for each hardware PMC. 610 * 611 * - At context switch IN time, each "target" PMC in RUNNING state 612 * gets started on hardware and a pointer to each PMC is copied into 613 * the per-cpu phw array. The 'runcount' for the PMC is 614 * incremented. 615 * 616 * - At context switch OUT time, all process-virtual PMCs are stopped 617 * on hardware. The saved value is added to the PMCs value field 618 * only if the PMC is in a non-deleted state (the PMCs state could 619 * have changed during the current time slice). 620 * 621 * Note that since in-between a switch IN on a processor and a switch 622 * OUT, the PMC could have been released on another CPU. Therefore 623 * context switch OUT always looks at the hardware state to turn 624 * OFF PMCs and will update a PMC's saved value only if reachable 625 * from the target process record. 626 * 627 * - OP PMCRELEASE could be called on a PMC at any time (the PMC could 628 * be attached to many processes at the time of the call and could 629 * be active on multiple CPUs). 630 * 631 * We prevent further scheduling of the PMC by marking it as in 632 * state 'DELETED'. If the runcount of the PMC is non-zero then 633 * this PMC is currently running on a CPU somewhere. The thread 634 * doing the PMCRELEASE operation waits by repeatedly doing a 635 * pause() till the runcount comes to zero. 636 * 637 * The contents of a PMC descriptor (struct pmc) are protected using 638 * a spin-mutex. In order to save space, we use a mutex pool. 639 * 640 * In terms of lock types used by witness(4), we use: 641 * - Type "pmc-sx", used by the global SX lock. 642 * - Type "pmc-sleep", for sleep mutexes used by logger threads. 643 * - Type "pmc-per-proc", for protecting PMC owner descriptors. 644 * - Type "pmc-leaf", used for all other spin mutexes. 645 */ 646 647 /* 648 * save the cpu binding of the current kthread 649 */ 650 651 static void 652 pmc_save_cpu_binding(struct pmc_binding *pb) 653 { 654 PMCDBG0(CPU,BND,2, "save-cpu"); 655 thread_lock(curthread); 656 pb->pb_bound = sched_is_bound(curthread); 657 pb->pb_cpu = curthread->td_oncpu; 658 thread_unlock(curthread); 659 PMCDBG1(CPU,BND,2, "save-cpu cpu=%d", pb->pb_cpu); 660 } 661 662 /* 663 * restore the cpu binding of the current thread 664 */ 665 666 static void 667 pmc_restore_cpu_binding(struct pmc_binding *pb) 668 { 669 PMCDBG2(CPU,BND,2, "restore-cpu curcpu=%d restore=%d", 670 curthread->td_oncpu, pb->pb_cpu); 671 thread_lock(curthread); 672 if (pb->pb_bound) 673 sched_bind(curthread, pb->pb_cpu); 674 else 675 sched_unbind(curthread); 676 thread_unlock(curthread); 677 PMCDBG0(CPU,BND,2, "restore-cpu done"); 678 } 679 680 /* 681 * move execution over the specified cpu and bind it there. 682 */ 683 684 static void 685 pmc_select_cpu(int cpu) 686 { 687 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 688 ("[pmc,%d] bad cpu number %d", __LINE__, cpu)); 689 690 /* Never move to an inactive CPU. */ 691 KASSERT(pmc_cpu_is_active(cpu), ("[pmc,%d] selecting inactive " 692 "CPU %d", __LINE__, cpu)); 693 694 PMCDBG1(CPU,SEL,2, "select-cpu cpu=%d", cpu); 695 thread_lock(curthread); 696 sched_bind(curthread, cpu); 697 thread_unlock(curthread); 698 699 KASSERT(curthread->td_oncpu == cpu, 700 ("[pmc,%d] CPU not bound [cpu=%d, curr=%d]", __LINE__, 701 cpu, curthread->td_oncpu)); 702 703 PMCDBG1(CPU,SEL,2, "select-cpu cpu=%d ok", cpu); 704 } 705 706 /* 707 * Force a context switch. 708 * 709 * We do this by pause'ing for 1 tick -- invoking mi_switch() is not 710 * guaranteed to force a context switch. 711 */ 712 713 static void 714 pmc_force_context_switch(void) 715 { 716 717 pause("pmcctx", 1); 718 } 719 720 /* 721 * Get the file name for an executable. This is a simple wrapper 722 * around vn_fullpath(9). 723 */ 724 725 static void 726 pmc_getfilename(struct vnode *v, char **fullpath, char **freepath) 727 { 728 729 *fullpath = "unknown"; 730 *freepath = NULL; 731 vn_fullpath(curthread, v, fullpath, freepath); 732 } 733 734 /* 735 * remove an process owning PMCs 736 */ 737 738 void 739 pmc_remove_owner(struct pmc_owner *po) 740 { 741 struct pmc *pm, *tmp; 742 743 sx_assert(&pmc_sx, SX_XLOCKED); 744 745 PMCDBG1(OWN,ORM,1, "remove-owner po=%p", po); 746 747 /* Remove descriptor from the owner hash table */ 748 LIST_REMOVE(po, po_next); 749 750 /* release all owned PMC descriptors */ 751 LIST_FOREACH_SAFE(pm, &po->po_pmcs, pm_next, tmp) { 752 PMCDBG1(OWN,ORM,2, "pmc=%p", pm); 753 KASSERT(pm->pm_owner == po, 754 ("[pmc,%d] owner %p != po %p", __LINE__, pm->pm_owner, po)); 755 756 pmc_release_pmc_descriptor(pm); /* will unlink from the list */ 757 pmc_destroy_pmc_descriptor(pm); 758 } 759 760 KASSERT(po->po_sscount == 0, 761 ("[pmc,%d] SS count not zero", __LINE__)); 762 KASSERT(LIST_EMPTY(&po->po_pmcs), 763 ("[pmc,%d] PMC list not empty", __LINE__)); 764 765 /* de-configure the log file if present */ 766 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 767 pmclog_deconfigure_log(po); 768 } 769 770 /* 771 * remove an owner process record if all conditions are met. 772 */ 773 774 static void 775 pmc_maybe_remove_owner(struct pmc_owner *po) 776 { 777 778 PMCDBG1(OWN,OMR,1, "maybe-remove-owner po=%p", po); 779 780 /* 781 * Remove owner record if 782 * - this process does not own any PMCs 783 * - this process has not allocated a system-wide sampling buffer 784 */ 785 786 if (LIST_EMPTY(&po->po_pmcs) && 787 ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0)) { 788 pmc_remove_owner(po); 789 pmc_destroy_owner_descriptor(po); 790 } 791 } 792 793 /* 794 * Add an association between a target process and a PMC. 795 */ 796 797 static void 798 pmc_link_target_process(struct pmc *pm, struct pmc_process *pp) 799 { 800 int ri; 801 struct pmc_target *pt; 802 803 sx_assert(&pmc_sx, SX_XLOCKED); 804 805 KASSERT(pm != NULL && pp != NULL, 806 ("[pmc,%d] Null pm %p or pp %p", __LINE__, pm, pp)); 807 KASSERT(PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)), 808 ("[pmc,%d] Attaching a non-process-virtual pmc=%p to pid=%d", 809 __LINE__, pm, pp->pp_proc->p_pid)); 810 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= ((int) md->pmd_npmc - 1), 811 ("[pmc,%d] Illegal reference count %d for process record %p", 812 __LINE__, pp->pp_refcnt, (void *) pp)); 813 814 ri = PMC_TO_ROWINDEX(pm); 815 816 PMCDBG3(PRC,TLK,1, "link-target pmc=%p ri=%d pmc-process=%p", 817 pm, ri, pp); 818 819 #ifdef HWPMC_DEBUG 820 LIST_FOREACH(pt, &pm->pm_targets, pt_next) 821 if (pt->pt_process == pp) 822 KASSERT(0, ("[pmc,%d] pp %p already in pmc %p targets", 823 __LINE__, pp, pm)); 824 #endif 825 826 pt = malloc(sizeof(struct pmc_target), M_PMC, M_WAITOK|M_ZERO); 827 pt->pt_process = pp; 828 829 LIST_INSERT_HEAD(&pm->pm_targets, pt, pt_next); 830 831 atomic_store_rel_ptr((uintptr_t *)&pp->pp_pmcs[ri].pp_pmc, 832 (uintptr_t)pm); 833 834 if (pm->pm_owner->po_owner == pp->pp_proc) 835 pm->pm_flags |= PMC_F_ATTACHED_TO_OWNER; 836 837 /* 838 * Initialize the per-process values at this row index. 839 */ 840 pp->pp_pmcs[ri].pp_pmcval = PMC_TO_MODE(pm) == PMC_MODE_TS ? 841 pm->pm_sc.pm_reloadcount : 0; 842 843 pp->pp_refcnt++; 844 845 } 846 847 /* 848 * Removes the association between a target process and a PMC. 849 */ 850 851 static void 852 pmc_unlink_target_process(struct pmc *pm, struct pmc_process *pp) 853 { 854 int ri; 855 struct proc *p; 856 struct pmc_target *ptgt; 857 858 sx_assert(&pmc_sx, SX_XLOCKED); 859 860 KASSERT(pm != NULL && pp != NULL, 861 ("[pmc,%d] Null pm %p or pp %p", __LINE__, pm, pp)); 862 863 KASSERT(pp->pp_refcnt >= 1 && pp->pp_refcnt <= (int) md->pmd_npmc, 864 ("[pmc,%d] Illegal ref count %d on process record %p", 865 __LINE__, pp->pp_refcnt, (void *) pp)); 866 867 ri = PMC_TO_ROWINDEX(pm); 868 869 PMCDBG3(PRC,TUL,1, "unlink-target pmc=%p ri=%d pmc-process=%p", 870 pm, ri, pp); 871 872 KASSERT(pp->pp_pmcs[ri].pp_pmc == pm, 873 ("[pmc,%d] PMC ri %d mismatch pmc %p pp->[ri] %p", __LINE__, 874 ri, pm, pp->pp_pmcs[ri].pp_pmc)); 875 876 pp->pp_pmcs[ri].pp_pmc = NULL; 877 pp->pp_pmcs[ri].pp_pmcval = (pmc_value_t) 0; 878 879 /* Remove owner-specific flags */ 880 if (pm->pm_owner->po_owner == pp->pp_proc) { 881 pp->pp_flags &= ~PMC_PP_ENABLE_MSR_ACCESS; 882 pm->pm_flags &= ~PMC_F_ATTACHED_TO_OWNER; 883 } 884 885 pp->pp_refcnt--; 886 887 /* Remove the target process from the PMC structure */ 888 LIST_FOREACH(ptgt, &pm->pm_targets, pt_next) 889 if (ptgt->pt_process == pp) 890 break; 891 892 KASSERT(ptgt != NULL, ("[pmc,%d] process %p (pp: %p) not found " 893 "in pmc %p", __LINE__, pp->pp_proc, pp, pm)); 894 895 LIST_REMOVE(ptgt, pt_next); 896 free(ptgt, M_PMC); 897 898 /* if the PMC now lacks targets, send the owner a SIGIO */ 899 if (LIST_EMPTY(&pm->pm_targets)) { 900 p = pm->pm_owner->po_owner; 901 PROC_LOCK(p); 902 kern_psignal(p, SIGIO); 903 PROC_UNLOCK(p); 904 905 PMCDBG2(PRC,SIG,2, "signalling proc=%p signal=%d", p, 906 SIGIO); 907 } 908 } 909 910 /* 911 * Check if PMC 'pm' may be attached to target process 't'. 912 */ 913 914 static int 915 pmc_can_attach(struct pmc *pm, struct proc *t) 916 { 917 struct proc *o; /* pmc owner */ 918 struct ucred *oc, *tc; /* owner, target credentials */ 919 int decline_attach, i; 920 921 /* 922 * A PMC's owner can always attach that PMC to itself. 923 */ 924 925 if ((o = pm->pm_owner->po_owner) == t) 926 return 0; 927 928 PROC_LOCK(o); 929 oc = o->p_ucred; 930 crhold(oc); 931 PROC_UNLOCK(o); 932 933 PROC_LOCK(t); 934 tc = t->p_ucred; 935 crhold(tc); 936 PROC_UNLOCK(t); 937 938 /* 939 * The effective uid of the PMC owner should match at least one 940 * of the {effective,real,saved} uids of the target process. 941 */ 942 943 decline_attach = oc->cr_uid != tc->cr_uid && 944 oc->cr_uid != tc->cr_svuid && 945 oc->cr_uid != tc->cr_ruid; 946 947 /* 948 * Every one of the target's group ids, must be in the owner's 949 * group list. 950 */ 951 for (i = 0; !decline_attach && i < tc->cr_ngroups; i++) 952 decline_attach = !groupmember(tc->cr_groups[i], oc); 953 954 /* check the read and saved gids too */ 955 if (decline_attach == 0) 956 decline_attach = !groupmember(tc->cr_rgid, oc) || 957 !groupmember(tc->cr_svgid, oc); 958 959 crfree(tc); 960 crfree(oc); 961 962 return !decline_attach; 963 } 964 965 /* 966 * Attach a process to a PMC. 967 */ 968 969 static int 970 pmc_attach_one_process(struct proc *p, struct pmc *pm) 971 { 972 int ri; 973 char *fullpath, *freepath; 974 struct pmc_process *pp; 975 976 sx_assert(&pmc_sx, SX_XLOCKED); 977 978 PMCDBG5(PRC,ATT,2, "attach-one pm=%p ri=%d proc=%p (%d, %s)", pm, 979 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 980 981 /* 982 * Locate the process descriptor corresponding to process 'p', 983 * allocating space as needed. 984 * 985 * Verify that rowindex 'pm_rowindex' is free in the process 986 * descriptor. 987 * 988 * If not, allocate space for a descriptor and link the 989 * process descriptor and PMC. 990 */ 991 ri = PMC_TO_ROWINDEX(pm); 992 993 if ((pp = pmc_find_process_descriptor(p, PMC_FLAG_ALLOCATE)) == NULL) 994 return ENOMEM; 995 996 if (pp->pp_pmcs[ri].pp_pmc == pm) /* already present at slot [ri] */ 997 return EEXIST; 998 999 if (pp->pp_pmcs[ri].pp_pmc != NULL) 1000 return EBUSY; 1001 1002 pmc_link_target_process(pm, pp); 1003 1004 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)) && 1005 (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) == 0) 1006 pm->pm_flags |= PMC_F_NEEDS_LOGFILE; 1007 1008 pm->pm_flags |= PMC_F_ATTACH_DONE; /* mark as attached */ 1009 1010 /* issue an attach event to a configured log file */ 1011 if (pm->pm_owner->po_flags & PMC_PO_OWNS_LOGFILE) { 1012 pmc_getfilename(p->p_textvp, &fullpath, &freepath); 1013 if (p->p_flag & P_KTHREAD) { 1014 fullpath = kernelname; 1015 freepath = NULL; 1016 } else 1017 pmclog_process_pmcattach(pm, p->p_pid, fullpath); 1018 if (freepath) 1019 free(freepath, M_TEMP); 1020 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 1021 pmc_log_process_mappings(pm->pm_owner, p); 1022 } 1023 /* mark process as using HWPMCs */ 1024 PROC_LOCK(p); 1025 p->p_flag |= P_HWPMC; 1026 PROC_UNLOCK(p); 1027 1028 return 0; 1029 } 1030 1031 /* 1032 * Attach a process and optionally its children 1033 */ 1034 1035 static int 1036 pmc_attach_process(struct proc *p, struct pmc *pm) 1037 { 1038 int error; 1039 struct proc *top; 1040 1041 sx_assert(&pmc_sx, SX_XLOCKED); 1042 1043 PMCDBG5(PRC,ATT,1, "attach pm=%p ri=%d proc=%p (%d, %s)", pm, 1044 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 1045 1046 1047 /* 1048 * If this PMC successfully allowed a GETMSR operation 1049 * in the past, disallow further ATTACHes. 1050 */ 1051 1052 if ((pm->pm_flags & PMC_PP_ENABLE_MSR_ACCESS) != 0) 1053 return EPERM; 1054 1055 if ((pm->pm_flags & PMC_F_DESCENDANTS) == 0) 1056 return pmc_attach_one_process(p, pm); 1057 1058 /* 1059 * Traverse all child processes, attaching them to 1060 * this PMC. 1061 */ 1062 1063 sx_slock(&proctree_lock); 1064 1065 top = p; 1066 1067 for (;;) { 1068 if ((error = pmc_attach_one_process(p, pm)) != 0) 1069 break; 1070 if (!LIST_EMPTY(&p->p_children)) 1071 p = LIST_FIRST(&p->p_children); 1072 else for (;;) { 1073 if (p == top) 1074 goto done; 1075 if (LIST_NEXT(p, p_sibling)) { 1076 p = LIST_NEXT(p, p_sibling); 1077 break; 1078 } 1079 p = p->p_pptr; 1080 } 1081 } 1082 1083 if (error) 1084 (void) pmc_detach_process(top, pm); 1085 1086 done: 1087 sx_sunlock(&proctree_lock); 1088 return error; 1089 } 1090 1091 /* 1092 * Detach a process from a PMC. If there are no other PMCs tracking 1093 * this process, remove the process structure from its hash table. If 1094 * 'flags' contains PMC_FLAG_REMOVE, then free the process structure. 1095 */ 1096 1097 static int 1098 pmc_detach_one_process(struct proc *p, struct pmc *pm, int flags) 1099 { 1100 int ri; 1101 struct pmc_process *pp; 1102 1103 sx_assert(&pmc_sx, SX_XLOCKED); 1104 1105 KASSERT(pm != NULL, 1106 ("[pmc,%d] null pm pointer", __LINE__)); 1107 1108 ri = PMC_TO_ROWINDEX(pm); 1109 1110 PMCDBG6(PRC,ATT,2, "detach-one pm=%p ri=%d proc=%p (%d, %s) flags=0x%x", 1111 pm, ri, p, p->p_pid, p->p_comm, flags); 1112 1113 if ((pp = pmc_find_process_descriptor(p, 0)) == NULL) 1114 return ESRCH; 1115 1116 if (pp->pp_pmcs[ri].pp_pmc != pm) 1117 return EINVAL; 1118 1119 pmc_unlink_target_process(pm, pp); 1120 1121 /* Issue a detach entry if a log file is configured */ 1122 if (pm->pm_owner->po_flags & PMC_PO_OWNS_LOGFILE) 1123 pmclog_process_pmcdetach(pm, p->p_pid); 1124 1125 /* 1126 * If there are no PMCs targetting this process, we remove its 1127 * descriptor from the target hash table and unset the P_HWPMC 1128 * flag in the struct proc. 1129 */ 1130 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= (int) md->pmd_npmc, 1131 ("[pmc,%d] Illegal refcnt %d for process struct %p", 1132 __LINE__, pp->pp_refcnt, pp)); 1133 1134 if (pp->pp_refcnt != 0) /* still a target of some PMC */ 1135 return 0; 1136 1137 pmc_remove_process_descriptor(pp); 1138 1139 if (flags & PMC_FLAG_REMOVE) 1140 free(pp, M_PMC); 1141 1142 PROC_LOCK(p); 1143 p->p_flag &= ~P_HWPMC; 1144 PROC_UNLOCK(p); 1145 1146 return 0; 1147 } 1148 1149 /* 1150 * Detach a process and optionally its descendants from a PMC. 1151 */ 1152 1153 static int 1154 pmc_detach_process(struct proc *p, struct pmc *pm) 1155 { 1156 struct proc *top; 1157 1158 sx_assert(&pmc_sx, SX_XLOCKED); 1159 1160 PMCDBG5(PRC,ATT,1, "detach pm=%p ri=%d proc=%p (%d, %s)", pm, 1161 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 1162 1163 if ((pm->pm_flags & PMC_F_DESCENDANTS) == 0) 1164 return pmc_detach_one_process(p, pm, PMC_FLAG_REMOVE); 1165 1166 /* 1167 * Traverse all children, detaching them from this PMC. We 1168 * ignore errors since we could be detaching a PMC from a 1169 * partially attached proc tree. 1170 */ 1171 1172 sx_slock(&proctree_lock); 1173 1174 top = p; 1175 1176 for (;;) { 1177 (void) pmc_detach_one_process(p, pm, PMC_FLAG_REMOVE); 1178 1179 if (!LIST_EMPTY(&p->p_children)) 1180 p = LIST_FIRST(&p->p_children); 1181 else for (;;) { 1182 if (p == top) 1183 goto done; 1184 if (LIST_NEXT(p, p_sibling)) { 1185 p = LIST_NEXT(p, p_sibling); 1186 break; 1187 } 1188 p = p->p_pptr; 1189 } 1190 } 1191 1192 done: 1193 sx_sunlock(&proctree_lock); 1194 1195 if (LIST_EMPTY(&pm->pm_targets)) 1196 pm->pm_flags &= ~PMC_F_ATTACH_DONE; 1197 1198 return 0; 1199 } 1200 1201 1202 /* 1203 * Thread context switch IN 1204 */ 1205 1206 static void 1207 pmc_process_csw_in(struct thread *td) 1208 { 1209 int cpu; 1210 unsigned int adjri, ri; 1211 struct pmc *pm; 1212 struct proc *p; 1213 struct pmc_cpu *pc; 1214 struct pmc_hw *phw; 1215 pmc_value_t newvalue; 1216 struct pmc_process *pp; 1217 struct pmc_classdep *pcd; 1218 1219 p = td->td_proc; 1220 1221 if ((pp = pmc_find_process_descriptor(p, PMC_FLAG_NONE)) == NULL) 1222 return; 1223 1224 KASSERT(pp->pp_proc == td->td_proc, 1225 ("[pmc,%d] not my thread state", __LINE__)); 1226 1227 critical_enter(); /* no preemption from this point */ 1228 1229 cpu = PCPU_GET(cpuid); /* td->td_oncpu is invalid */ 1230 1231 PMCDBG5(CSW,SWI,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p, 1232 p->p_pid, p->p_comm, pp); 1233 1234 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 1235 ("[pmc,%d] wierd CPU id %d", __LINE__, cpu)); 1236 1237 pc = pmc_pcpu[cpu]; 1238 1239 for (ri = 0; ri < md->pmd_npmc; ri++) { 1240 1241 if ((pm = pp->pp_pmcs[ri].pp_pmc) == NULL) 1242 continue; 1243 1244 KASSERT(PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)), 1245 ("[pmc,%d] Target PMC in non-virtual mode (%d)", 1246 __LINE__, PMC_TO_MODE(pm))); 1247 1248 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 1249 ("[pmc,%d] Row index mismatch pmc %d != ri %d", 1250 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 1251 1252 /* 1253 * Only PMCs that are marked as 'RUNNING' need 1254 * be placed on hardware. 1255 */ 1256 1257 if (pm->pm_state != PMC_STATE_RUNNING) 1258 continue; 1259 1260 /* increment PMC runcount */ 1261 atomic_add_rel_int(&pm->pm_runcount, 1); 1262 1263 /* configure the HWPMC we are going to use. */ 1264 pcd = pmc_ri_to_classdep(md, ri, &adjri); 1265 pcd->pcd_config_pmc(cpu, adjri, pm); 1266 1267 phw = pc->pc_hwpmcs[ri]; 1268 1269 KASSERT(phw != NULL, 1270 ("[pmc,%d] null hw pointer", __LINE__)); 1271 1272 KASSERT(phw->phw_pmc == pm, 1273 ("[pmc,%d] hw->pmc %p != pmc %p", __LINE__, 1274 phw->phw_pmc, pm)); 1275 1276 /* 1277 * Write out saved value and start the PMC. 1278 * 1279 * Sampling PMCs use a per-process value, while 1280 * counting mode PMCs use a per-pmc value that is 1281 * inherited across descendants. 1282 */ 1283 if (PMC_TO_MODE(pm) == PMC_MODE_TS) { 1284 mtx_pool_lock_spin(pmc_mtxpool, pm); 1285 newvalue = PMC_PCPU_SAVED(cpu,ri) = 1286 pp->pp_pmcs[ri].pp_pmcval; 1287 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1288 } else { 1289 KASSERT(PMC_TO_MODE(pm) == PMC_MODE_TC, 1290 ("[pmc,%d] illegal mode=%d", __LINE__, 1291 PMC_TO_MODE(pm))); 1292 mtx_pool_lock_spin(pmc_mtxpool, pm); 1293 newvalue = PMC_PCPU_SAVED(cpu, ri) = 1294 pm->pm_gv.pm_savedvalue; 1295 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1296 } 1297 1298 PMCDBG3(CSW,SWI,1,"cpu=%d ri=%d new=%jd", cpu, ri, newvalue); 1299 1300 pcd->pcd_write_pmc(cpu, adjri, newvalue); 1301 1302 /* If a sampling mode PMC, reset stalled state. */ 1303 if (PMC_TO_MODE(pm) == PMC_MODE_TS) 1304 CPU_CLR_ATOMIC(cpu, &pm->pm_stalled); 1305 1306 /* Indicate that we desire this to run. */ 1307 CPU_SET_ATOMIC(cpu, &pm->pm_cpustate); 1308 1309 /* Start the PMC. */ 1310 pcd->pcd_start_pmc(cpu, adjri); 1311 } 1312 1313 /* 1314 * perform any other architecture/cpu dependent thread 1315 * switch-in actions. 1316 */ 1317 1318 (void) (*md->pmd_switch_in)(pc, pp); 1319 1320 critical_exit(); 1321 1322 } 1323 1324 /* 1325 * Thread context switch OUT. 1326 */ 1327 1328 static void 1329 pmc_process_csw_out(struct thread *td) 1330 { 1331 int cpu; 1332 int64_t tmp; 1333 struct pmc *pm; 1334 struct proc *p; 1335 enum pmc_mode mode; 1336 struct pmc_cpu *pc; 1337 pmc_value_t newvalue; 1338 unsigned int adjri, ri; 1339 struct pmc_process *pp; 1340 struct pmc_classdep *pcd; 1341 1342 1343 /* 1344 * Locate our process descriptor; this may be NULL if 1345 * this process is exiting and we have already removed 1346 * the process from the target process table. 1347 * 1348 * Note that due to kernel preemption, multiple 1349 * context switches may happen while the process is 1350 * exiting. 1351 * 1352 * Note also that if the target process cannot be 1353 * found we still need to deconfigure any PMCs that 1354 * are currently running on hardware. 1355 */ 1356 1357 p = td->td_proc; 1358 pp = pmc_find_process_descriptor(p, PMC_FLAG_NONE); 1359 1360 /* 1361 * save PMCs 1362 */ 1363 1364 critical_enter(); 1365 1366 cpu = PCPU_GET(cpuid); /* td->td_oncpu is invalid */ 1367 1368 PMCDBG5(CSW,SWO,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p, 1369 p->p_pid, p->p_comm, pp); 1370 1371 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 1372 ("[pmc,%d wierd CPU id %d", __LINE__, cpu)); 1373 1374 pc = pmc_pcpu[cpu]; 1375 1376 /* 1377 * When a PMC gets unlinked from a target PMC, it will 1378 * be removed from the target's pp_pmc[] array. 1379 * 1380 * However, on a MP system, the target could have been 1381 * executing on another CPU at the time of the unlink. 1382 * So, at context switch OUT time, we need to look at 1383 * the hardware to determine if a PMC is scheduled on 1384 * it. 1385 */ 1386 1387 for (ri = 0; ri < md->pmd_npmc; ri++) { 1388 1389 pcd = pmc_ri_to_classdep(md, ri, &adjri); 1390 pm = NULL; 1391 (void) (*pcd->pcd_get_config)(cpu, adjri, &pm); 1392 1393 if (pm == NULL) /* nothing at this row index */ 1394 continue; 1395 1396 mode = PMC_TO_MODE(pm); 1397 if (!PMC_IS_VIRTUAL_MODE(mode)) 1398 continue; /* not a process virtual PMC */ 1399 1400 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 1401 ("[pmc,%d] ri mismatch pmc(%d) ri(%d)", 1402 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 1403 1404 /* 1405 * Change desired state, and then stop if not stalled. 1406 * This two-step dance should avoid race conditions where 1407 * an interrupt re-enables the PMC after this code has 1408 * already checked the pm_stalled flag. 1409 */ 1410 CPU_CLR_ATOMIC(cpu, &pm->pm_cpustate); 1411 if (!CPU_ISSET(cpu, &pm->pm_stalled)) 1412 pcd->pcd_stop_pmc(cpu, adjri); 1413 1414 /* reduce this PMC's runcount */ 1415 atomic_subtract_rel_int(&pm->pm_runcount, 1); 1416 1417 /* 1418 * If this PMC is associated with this process, 1419 * save the reading. 1420 */ 1421 1422 if (pp != NULL && pp->pp_pmcs[ri].pp_pmc != NULL) { 1423 1424 KASSERT(pm == pp->pp_pmcs[ri].pp_pmc, 1425 ("[pmc,%d] pm %p != pp_pmcs[%d] %p", __LINE__, 1426 pm, ri, pp->pp_pmcs[ri].pp_pmc)); 1427 1428 KASSERT(pp->pp_refcnt > 0, 1429 ("[pmc,%d] pp refcnt = %d", __LINE__, 1430 pp->pp_refcnt)); 1431 1432 pcd->pcd_read_pmc(cpu, adjri, &newvalue); 1433 1434 tmp = newvalue - PMC_PCPU_SAVED(cpu,ri); 1435 1436 PMCDBG3(CSW,SWO,1,"cpu=%d ri=%d tmp=%jd", cpu, ri, 1437 tmp); 1438 1439 if (mode == PMC_MODE_TS) { 1440 1441 /* 1442 * For sampling process-virtual PMCs, 1443 * we expect the count to be 1444 * decreasing as the 'value' 1445 * programmed into the PMC is the 1446 * number of events to be seen till 1447 * the next sampling interrupt. 1448 */ 1449 if (tmp < 0) 1450 tmp += pm->pm_sc.pm_reloadcount; 1451 mtx_pool_lock_spin(pmc_mtxpool, pm); 1452 pp->pp_pmcs[ri].pp_pmcval -= tmp; 1453 if ((int64_t) pp->pp_pmcs[ri].pp_pmcval <= 0) 1454 pp->pp_pmcs[ri].pp_pmcval += 1455 pm->pm_sc.pm_reloadcount; 1456 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1457 1458 } else { 1459 1460 /* 1461 * For counting process-virtual PMCs, 1462 * we expect the count to be 1463 * increasing monotonically, modulo a 64 1464 * bit wraparound. 1465 */ 1466 KASSERT((int64_t) tmp >= 0, 1467 ("[pmc,%d] negative increment cpu=%d " 1468 "ri=%d newvalue=%jx saved=%jx " 1469 "incr=%jx", __LINE__, cpu, ri, 1470 newvalue, PMC_PCPU_SAVED(cpu,ri), tmp)); 1471 1472 mtx_pool_lock_spin(pmc_mtxpool, pm); 1473 pm->pm_gv.pm_savedvalue += tmp; 1474 pp->pp_pmcs[ri].pp_pmcval += tmp; 1475 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1476 1477 if (pm->pm_flags & PMC_F_LOG_PROCCSW) 1478 pmclog_process_proccsw(pm, pp, tmp); 1479 } 1480 } 1481 1482 /* mark hardware as free */ 1483 pcd->pcd_config_pmc(cpu, adjri, NULL); 1484 } 1485 1486 /* 1487 * perform any other architecture/cpu dependent thread 1488 * switch out functions. 1489 */ 1490 1491 (void) (*md->pmd_switch_out)(pc, pp); 1492 1493 critical_exit(); 1494 } 1495 1496 /* 1497 * A mapping change for a process. 1498 */ 1499 1500 static void 1501 pmc_process_mmap(struct thread *td, struct pmckern_map_in *pkm) 1502 { 1503 int ri; 1504 pid_t pid; 1505 char *fullpath, *freepath; 1506 const struct pmc *pm; 1507 struct pmc_owner *po; 1508 const struct pmc_process *pp; 1509 1510 freepath = fullpath = NULL; 1511 pmc_getfilename((struct vnode *) pkm->pm_file, &fullpath, &freepath); 1512 1513 pid = td->td_proc->p_pid; 1514 1515 /* Inform owners of all system-wide sampling PMCs. */ 1516 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1517 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1518 pmclog_process_map_in(po, pid, pkm->pm_address, fullpath); 1519 1520 if ((pp = pmc_find_process_descriptor(td->td_proc, 0)) == NULL) 1521 goto done; 1522 1523 /* 1524 * Inform sampling PMC owners tracking this process. 1525 */ 1526 for (ri = 0; ri < md->pmd_npmc; ri++) 1527 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL && 1528 PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 1529 pmclog_process_map_in(pm->pm_owner, 1530 pid, pkm->pm_address, fullpath); 1531 1532 done: 1533 if (freepath) 1534 free(freepath, M_TEMP); 1535 } 1536 1537 1538 /* 1539 * Log an munmap request. 1540 */ 1541 1542 static void 1543 pmc_process_munmap(struct thread *td, struct pmckern_map_out *pkm) 1544 { 1545 int ri; 1546 pid_t pid; 1547 struct pmc_owner *po; 1548 const struct pmc *pm; 1549 const struct pmc_process *pp; 1550 1551 pid = td->td_proc->p_pid; 1552 1553 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1554 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1555 pmclog_process_map_out(po, pid, pkm->pm_address, 1556 pkm->pm_address + pkm->pm_size); 1557 1558 if ((pp = pmc_find_process_descriptor(td->td_proc, 0)) == NULL) 1559 return; 1560 1561 for (ri = 0; ri < md->pmd_npmc; ri++) 1562 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL && 1563 PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 1564 pmclog_process_map_out(pm->pm_owner, pid, 1565 pkm->pm_address, pkm->pm_address + pkm->pm_size); 1566 } 1567 1568 /* 1569 * Log mapping information about the kernel. 1570 */ 1571 1572 static void 1573 pmc_log_kernel_mappings(struct pmc *pm) 1574 { 1575 struct pmc_owner *po; 1576 struct pmckern_map_in *km, *kmbase; 1577 1578 sx_assert(&pmc_sx, SX_LOCKED); 1579 KASSERT(PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)), 1580 ("[pmc,%d] non-sampling PMC (%p) desires mapping information", 1581 __LINE__, (void *) pm)); 1582 1583 po = pm->pm_owner; 1584 1585 if (po->po_flags & PMC_PO_INITIAL_MAPPINGS_DONE) 1586 return; 1587 1588 /* 1589 * Log the current set of kernel modules. 1590 */ 1591 kmbase = linker_hwpmc_list_objects(); 1592 for (km = kmbase; km->pm_file != NULL; km++) { 1593 PMCDBG2(LOG,REG,1,"%s %p", (char *) km->pm_file, 1594 (void *) km->pm_address); 1595 pmclog_process_map_in(po, (pid_t) -1, km->pm_address, 1596 km->pm_file); 1597 } 1598 free(kmbase, M_LINKER); 1599 1600 po->po_flags |= PMC_PO_INITIAL_MAPPINGS_DONE; 1601 } 1602 1603 /* 1604 * Log the mappings for a single process. 1605 */ 1606 1607 static void 1608 pmc_log_process_mappings(struct pmc_owner *po, struct proc *p) 1609 { 1610 vm_map_t map; 1611 struct vnode *vp; 1612 struct vmspace *vm; 1613 vm_map_entry_t entry; 1614 vm_offset_t last_end; 1615 u_int last_timestamp; 1616 struct vnode *last_vp; 1617 vm_offset_t start_addr; 1618 vm_object_t obj, lobj, tobj; 1619 char *fullpath, *freepath; 1620 1621 last_vp = NULL; 1622 last_end = (vm_offset_t) 0; 1623 fullpath = freepath = NULL; 1624 1625 if ((vm = vmspace_acquire_ref(p)) == NULL) 1626 return; 1627 1628 map = &vm->vm_map; 1629 vm_map_lock_read(map); 1630 1631 for (entry = map->header.next; entry != &map->header; entry = entry->next) { 1632 1633 if (entry == NULL) { 1634 PMCDBG2(LOG,OPS,2, "hwpmc: vm_map entry unexpectedly " 1635 "NULL! pid=%d vm_map=%p\n", p->p_pid, map); 1636 break; 1637 } 1638 1639 /* 1640 * We only care about executable map entries. 1641 */ 1642 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) || 1643 !(entry->protection & VM_PROT_EXECUTE) || 1644 (entry->object.vm_object == NULL)) { 1645 continue; 1646 } 1647 1648 obj = entry->object.vm_object; 1649 VM_OBJECT_RLOCK(obj); 1650 1651 /* 1652 * Walk the backing_object list to find the base 1653 * (non-shadowed) vm_object. 1654 */ 1655 for (lobj = tobj = obj; tobj != NULL; tobj = tobj->backing_object) { 1656 if (tobj != obj) 1657 VM_OBJECT_RLOCK(tobj); 1658 if (lobj != obj) 1659 VM_OBJECT_RUNLOCK(lobj); 1660 lobj = tobj; 1661 } 1662 1663 /* 1664 * At this point lobj is the base vm_object and it is locked. 1665 */ 1666 if (lobj == NULL) { 1667 PMCDBG3(LOG,OPS,2, "hwpmc: lobj unexpectedly NULL! pid=%d " 1668 "vm_map=%p vm_obj=%p\n", p->p_pid, map, obj); 1669 VM_OBJECT_RUNLOCK(obj); 1670 continue; 1671 } 1672 1673 vp = vm_object_vnode(lobj); 1674 if (vp == NULL) { 1675 if (lobj != obj) 1676 VM_OBJECT_RUNLOCK(lobj); 1677 VM_OBJECT_RUNLOCK(obj); 1678 continue; 1679 } 1680 1681 /* 1682 * Skip contiguous regions that point to the same 1683 * vnode, so we don't emit redundant MAP-IN 1684 * directives. 1685 */ 1686 if (entry->start == last_end && vp == last_vp) { 1687 last_end = entry->end; 1688 if (lobj != obj) 1689 VM_OBJECT_RUNLOCK(lobj); 1690 VM_OBJECT_RUNLOCK(obj); 1691 continue; 1692 } 1693 1694 /* 1695 * We don't want to keep the proc's vm_map or this 1696 * vm_object locked while we walk the pathname, since 1697 * vn_fullpath() can sleep. However, if we drop the 1698 * lock, it's possible for concurrent activity to 1699 * modify the vm_map list. To protect against this, 1700 * we save the vm_map timestamp before we release the 1701 * lock, and check it after we reacquire the lock 1702 * below. 1703 */ 1704 start_addr = entry->start; 1705 last_end = entry->end; 1706 last_timestamp = map->timestamp; 1707 vm_map_unlock_read(map); 1708 1709 vref(vp); 1710 if (lobj != obj) 1711 VM_OBJECT_RUNLOCK(lobj); 1712 1713 VM_OBJECT_RUNLOCK(obj); 1714 1715 freepath = NULL; 1716 pmc_getfilename(vp, &fullpath, &freepath); 1717 last_vp = vp; 1718 1719 vrele(vp); 1720 1721 vp = NULL; 1722 pmclog_process_map_in(po, p->p_pid, start_addr, fullpath); 1723 if (freepath) 1724 free(freepath, M_TEMP); 1725 1726 vm_map_lock_read(map); 1727 1728 /* 1729 * If our saved timestamp doesn't match, this means 1730 * that the vm_map was modified out from under us and 1731 * we can't trust our current "entry" pointer. Do a 1732 * new lookup for this entry. If there is no entry 1733 * for this address range, vm_map_lookup_entry() will 1734 * return the previous one, so we always want to go to 1735 * entry->next on the next loop iteration. 1736 * 1737 * There is an edge condition here that can occur if 1738 * there is no entry at or before this address. In 1739 * this situation, vm_map_lookup_entry returns 1740 * &map->header, which would cause our loop to abort 1741 * without processing the rest of the map. However, 1742 * in practice this will never happen for process 1743 * vm_map. This is because the executable's text 1744 * segment is the first mapping in the proc's address 1745 * space, and this mapping is never removed until the 1746 * process exits, so there will always be a non-header 1747 * entry at or before the requested address for 1748 * vm_map_lookup_entry to return. 1749 */ 1750 if (map->timestamp != last_timestamp) 1751 vm_map_lookup_entry(map, last_end - 1, &entry); 1752 } 1753 1754 vm_map_unlock_read(map); 1755 vmspace_free(vm); 1756 return; 1757 } 1758 1759 /* 1760 * Log mappings for all processes in the system. 1761 */ 1762 1763 static void 1764 pmc_log_all_process_mappings(struct pmc_owner *po) 1765 { 1766 struct proc *p, *top; 1767 1768 sx_assert(&pmc_sx, SX_XLOCKED); 1769 1770 if ((p = pfind(1)) == NULL) 1771 panic("[pmc,%d] Cannot find init", __LINE__); 1772 1773 PROC_UNLOCK(p); 1774 1775 sx_slock(&proctree_lock); 1776 1777 top = p; 1778 1779 for (;;) { 1780 pmc_log_process_mappings(po, p); 1781 if (!LIST_EMPTY(&p->p_children)) 1782 p = LIST_FIRST(&p->p_children); 1783 else for (;;) { 1784 if (p == top) 1785 goto done; 1786 if (LIST_NEXT(p, p_sibling)) { 1787 p = LIST_NEXT(p, p_sibling); 1788 break; 1789 } 1790 p = p->p_pptr; 1791 } 1792 } 1793 done: 1794 sx_sunlock(&proctree_lock); 1795 } 1796 1797 /* 1798 * The 'hook' invoked from the kernel proper 1799 */ 1800 1801 1802 #ifdef HWPMC_DEBUG 1803 const char *pmc_hooknames[] = { 1804 /* these strings correspond to PMC_FN_* in <sys/pmckern.h> */ 1805 "", 1806 "EXEC", 1807 "CSW-IN", 1808 "CSW-OUT", 1809 "SAMPLE", 1810 "UNUSED1", 1811 "UNUSED2", 1812 "MMAP", 1813 "MUNMAP", 1814 "CALLCHAIN-NMI", 1815 "CALLCHAIN-SOFT", 1816 "SOFTSAMPLING" 1817 }; 1818 #endif 1819 1820 static int 1821 pmc_hook_handler(struct thread *td, int function, void *arg) 1822 { 1823 1824 PMCDBG4(MOD,PMH,1, "hook td=%p func=%d \"%s\" arg=%p", td, function, 1825 pmc_hooknames[function], arg); 1826 1827 switch (function) 1828 { 1829 1830 /* 1831 * Process exec() 1832 */ 1833 1834 case PMC_FN_PROCESS_EXEC: 1835 { 1836 char *fullpath, *freepath; 1837 unsigned int ri; 1838 int is_using_hwpmcs; 1839 struct pmc *pm; 1840 struct proc *p; 1841 struct pmc_owner *po; 1842 struct pmc_process *pp; 1843 struct pmckern_procexec *pk; 1844 1845 sx_assert(&pmc_sx, SX_XLOCKED); 1846 1847 p = td->td_proc; 1848 pmc_getfilename(p->p_textvp, &fullpath, &freepath); 1849 1850 pk = (struct pmckern_procexec *) arg; 1851 1852 /* Inform owners of SS mode PMCs of the exec event. */ 1853 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1854 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1855 pmclog_process_procexec(po, PMC_ID_INVALID, 1856 p->p_pid, pk->pm_entryaddr, fullpath); 1857 1858 PROC_LOCK(p); 1859 is_using_hwpmcs = p->p_flag & P_HWPMC; 1860 PROC_UNLOCK(p); 1861 1862 if (!is_using_hwpmcs) { 1863 if (freepath) 1864 free(freepath, M_TEMP); 1865 break; 1866 } 1867 1868 /* 1869 * PMCs are not inherited across an exec(): remove any 1870 * PMCs that this process is the owner of. 1871 */ 1872 1873 if ((po = pmc_find_owner_descriptor(p)) != NULL) { 1874 pmc_remove_owner(po); 1875 pmc_destroy_owner_descriptor(po); 1876 } 1877 1878 /* 1879 * If the process being exec'ed is not the target of any 1880 * PMC, we are done. 1881 */ 1882 if ((pp = pmc_find_process_descriptor(p, 0)) == NULL) { 1883 if (freepath) 1884 free(freepath, M_TEMP); 1885 break; 1886 } 1887 1888 /* 1889 * Log the exec event to all monitoring owners. Skip 1890 * owners who have already recieved the event because 1891 * they had system sampling PMCs active. 1892 */ 1893 for (ri = 0; ri < md->pmd_npmc; ri++) 1894 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) { 1895 po = pm->pm_owner; 1896 if (po->po_sscount == 0 && 1897 po->po_flags & PMC_PO_OWNS_LOGFILE) 1898 pmclog_process_procexec(po, pm->pm_id, 1899 p->p_pid, pk->pm_entryaddr, 1900 fullpath); 1901 } 1902 1903 if (freepath) 1904 free(freepath, M_TEMP); 1905 1906 1907 PMCDBG4(PRC,EXC,1, "exec proc=%p (%d, %s) cred-changed=%d", 1908 p, p->p_pid, p->p_comm, pk->pm_credentialschanged); 1909 1910 if (pk->pm_credentialschanged == 0) /* no change */ 1911 break; 1912 1913 /* 1914 * If the newly exec()'ed process has a different credential 1915 * than before, allow it to be the target of a PMC only if 1916 * the PMC's owner has sufficient priviledge. 1917 */ 1918 1919 for (ri = 0; ri < md->pmd_npmc; ri++) 1920 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) 1921 if (pmc_can_attach(pm, td->td_proc) != 0) 1922 pmc_detach_one_process(td->td_proc, 1923 pm, PMC_FLAG_NONE); 1924 1925 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= (int) md->pmd_npmc, 1926 ("[pmc,%d] Illegal ref count %d on pp %p", __LINE__, 1927 pp->pp_refcnt, pp)); 1928 1929 /* 1930 * If this process is no longer the target of any 1931 * PMCs, we can remove the process entry and free 1932 * up space. 1933 */ 1934 1935 if (pp->pp_refcnt == 0) { 1936 pmc_remove_process_descriptor(pp); 1937 free(pp, M_PMC); 1938 break; 1939 } 1940 1941 } 1942 break; 1943 1944 case PMC_FN_CSW_IN: 1945 pmc_process_csw_in(td); 1946 break; 1947 1948 case PMC_FN_CSW_OUT: 1949 pmc_process_csw_out(td); 1950 break; 1951 1952 /* 1953 * Process accumulated PC samples. 1954 * 1955 * This function is expected to be called by hardclock() for 1956 * each CPU that has accumulated PC samples. 1957 * 1958 * This function is to be executed on the CPU whose samples 1959 * are being processed. 1960 */ 1961 case PMC_FN_DO_SAMPLES: 1962 1963 /* 1964 * Clear the cpu specific bit in the CPU mask before 1965 * do the rest of the processing. If the NMI handler 1966 * gets invoked after the "atomic_clear_int()" call 1967 * below but before "pmc_process_samples()" gets 1968 * around to processing the interrupt, then we will 1969 * come back here at the next hardclock() tick (and 1970 * may find nothing to do if "pmc_process_samples()" 1971 * had already processed the interrupt). We don't 1972 * lose the interrupt sample. 1973 */ 1974 CPU_CLR_ATOMIC(PCPU_GET(cpuid), &pmc_cpumask); 1975 pmc_process_samples(PCPU_GET(cpuid), PMC_HR); 1976 pmc_process_samples(PCPU_GET(cpuid), PMC_SR); 1977 break; 1978 1979 case PMC_FN_MMAP: 1980 sx_assert(&pmc_sx, SX_LOCKED); 1981 pmc_process_mmap(td, (struct pmckern_map_in *) arg); 1982 break; 1983 1984 case PMC_FN_MUNMAP: 1985 sx_assert(&pmc_sx, SX_LOCKED); 1986 pmc_process_munmap(td, (struct pmckern_map_out *) arg); 1987 break; 1988 1989 case PMC_FN_USER_CALLCHAIN: 1990 /* 1991 * Record a call chain. 1992 */ 1993 KASSERT(td == curthread, ("[pmc,%d] td != curthread", 1994 __LINE__)); 1995 1996 pmc_capture_user_callchain(PCPU_GET(cpuid), PMC_HR, 1997 (struct trapframe *) arg); 1998 td->td_pflags &= ~TDP_CALLCHAIN; 1999 break; 2000 2001 case PMC_FN_USER_CALLCHAIN_SOFT: 2002 /* 2003 * Record a call chain. 2004 */ 2005 KASSERT(td == curthread, ("[pmc,%d] td != curthread", 2006 __LINE__)); 2007 pmc_capture_user_callchain(PCPU_GET(cpuid), PMC_SR, 2008 (struct trapframe *) arg); 2009 td->td_pflags &= ~TDP_CALLCHAIN; 2010 break; 2011 2012 case PMC_FN_SOFT_SAMPLING: 2013 /* 2014 * Call soft PMC sampling intr. 2015 */ 2016 pmc_soft_intr((struct pmckern_soft *) arg); 2017 break; 2018 2019 default: 2020 #ifdef HWPMC_DEBUG 2021 KASSERT(0, ("[pmc,%d] unknown hook %d\n", __LINE__, function)); 2022 #endif 2023 break; 2024 2025 } 2026 2027 return 0; 2028 } 2029 2030 /* 2031 * allocate a 'struct pmc_owner' descriptor in the owner hash table. 2032 */ 2033 2034 static struct pmc_owner * 2035 pmc_allocate_owner_descriptor(struct proc *p) 2036 { 2037 uint32_t hindex; 2038 struct pmc_owner *po; 2039 struct pmc_ownerhash *poh; 2040 2041 hindex = PMC_HASH_PTR(p, pmc_ownerhashmask); 2042 poh = &pmc_ownerhash[hindex]; 2043 2044 /* allocate space for N pointers and one descriptor struct */ 2045 po = malloc(sizeof(struct pmc_owner), M_PMC, M_WAITOK|M_ZERO); 2046 po->po_owner = p; 2047 LIST_INSERT_HEAD(poh, po, po_next); /* insert into hash table */ 2048 2049 TAILQ_INIT(&po->po_logbuffers); 2050 mtx_init(&po->po_mtx, "pmc-owner-mtx", "pmc-per-proc", MTX_SPIN); 2051 2052 PMCDBG4(OWN,ALL,1, "allocate-owner proc=%p (%d, %s) pmc-owner=%p", 2053 p, p->p_pid, p->p_comm, po); 2054 2055 return po; 2056 } 2057 2058 static void 2059 pmc_destroy_owner_descriptor(struct pmc_owner *po) 2060 { 2061 2062 PMCDBG4(OWN,REL,1, "destroy-owner po=%p proc=%p (%d, %s)", 2063 po, po->po_owner, po->po_owner->p_pid, po->po_owner->p_comm); 2064 2065 mtx_destroy(&po->po_mtx); 2066 free(po, M_PMC); 2067 } 2068 2069 /* 2070 * find the descriptor corresponding to process 'p', adding or removing it 2071 * as specified by 'mode'. 2072 */ 2073 2074 static struct pmc_process * 2075 pmc_find_process_descriptor(struct proc *p, uint32_t mode) 2076 { 2077 uint32_t hindex; 2078 struct pmc_process *pp, *ppnew; 2079 struct pmc_processhash *pph; 2080 2081 hindex = PMC_HASH_PTR(p, pmc_processhashmask); 2082 pph = &pmc_processhash[hindex]; 2083 2084 ppnew = NULL; 2085 2086 /* 2087 * Pre-allocate memory in the FIND_ALLOCATE case since we 2088 * cannot call malloc(9) once we hold a spin lock. 2089 */ 2090 if (mode & PMC_FLAG_ALLOCATE) 2091 ppnew = malloc(sizeof(struct pmc_process) + md->pmd_npmc * 2092 sizeof(struct pmc_targetstate), M_PMC, M_WAITOK|M_ZERO); 2093 2094 mtx_lock_spin(&pmc_processhash_mtx); 2095 LIST_FOREACH(pp, pph, pp_next) 2096 if (pp->pp_proc == p) 2097 break; 2098 2099 if ((mode & PMC_FLAG_REMOVE) && pp != NULL) 2100 LIST_REMOVE(pp, pp_next); 2101 2102 if ((mode & PMC_FLAG_ALLOCATE) && pp == NULL && 2103 ppnew != NULL) { 2104 ppnew->pp_proc = p; 2105 LIST_INSERT_HEAD(pph, ppnew, pp_next); 2106 pp = ppnew; 2107 ppnew = NULL; 2108 } 2109 mtx_unlock_spin(&pmc_processhash_mtx); 2110 2111 if (pp != NULL && ppnew != NULL) 2112 free(ppnew, M_PMC); 2113 2114 return pp; 2115 } 2116 2117 /* 2118 * remove a process descriptor from the process hash table. 2119 */ 2120 2121 static void 2122 pmc_remove_process_descriptor(struct pmc_process *pp) 2123 { 2124 KASSERT(pp->pp_refcnt == 0, 2125 ("[pmc,%d] Removing process descriptor %p with count %d", 2126 __LINE__, pp, pp->pp_refcnt)); 2127 2128 mtx_lock_spin(&pmc_processhash_mtx); 2129 LIST_REMOVE(pp, pp_next); 2130 mtx_unlock_spin(&pmc_processhash_mtx); 2131 } 2132 2133 2134 /* 2135 * find an owner descriptor corresponding to proc 'p' 2136 */ 2137 2138 static struct pmc_owner * 2139 pmc_find_owner_descriptor(struct proc *p) 2140 { 2141 uint32_t hindex; 2142 struct pmc_owner *po; 2143 struct pmc_ownerhash *poh; 2144 2145 hindex = PMC_HASH_PTR(p, pmc_ownerhashmask); 2146 poh = &pmc_ownerhash[hindex]; 2147 2148 po = NULL; 2149 LIST_FOREACH(po, poh, po_next) 2150 if (po->po_owner == p) 2151 break; 2152 2153 PMCDBG5(OWN,FND,1, "find-owner proc=%p (%d, %s) hindex=0x%x -> " 2154 "pmc-owner=%p", p, p->p_pid, p->p_comm, hindex, po); 2155 2156 return po; 2157 } 2158 2159 /* 2160 * pmc_allocate_pmc_descriptor 2161 * 2162 * Allocate a pmc descriptor and initialize its 2163 * fields. 2164 */ 2165 2166 static struct pmc * 2167 pmc_allocate_pmc_descriptor(void) 2168 { 2169 struct pmc *pmc; 2170 2171 pmc = malloc(sizeof(struct pmc), M_PMC, M_WAITOK|M_ZERO); 2172 2173 PMCDBG1(PMC,ALL,1, "allocate-pmc -> pmc=%p", pmc); 2174 2175 return pmc; 2176 } 2177 2178 /* 2179 * Destroy a pmc descriptor. 2180 */ 2181 2182 static void 2183 pmc_destroy_pmc_descriptor(struct pmc *pm) 2184 { 2185 2186 KASSERT(pm->pm_state == PMC_STATE_DELETED || 2187 pm->pm_state == PMC_STATE_FREE, 2188 ("[pmc,%d] destroying non-deleted PMC", __LINE__)); 2189 KASSERT(LIST_EMPTY(&pm->pm_targets), 2190 ("[pmc,%d] destroying pmc with targets", __LINE__)); 2191 KASSERT(pm->pm_owner == NULL, 2192 ("[pmc,%d] destroying pmc attached to an owner", __LINE__)); 2193 KASSERT(pm->pm_runcount == 0, 2194 ("[pmc,%d] pmc has non-zero run count %d", __LINE__, 2195 pm->pm_runcount)); 2196 2197 free(pm, M_PMC); 2198 } 2199 2200 static void 2201 pmc_wait_for_pmc_idle(struct pmc *pm) 2202 { 2203 #ifdef HWPMC_DEBUG 2204 volatile int maxloop; 2205 2206 maxloop = 100 * pmc_cpu_max(); 2207 #endif 2208 /* 2209 * Loop (with a forced context switch) till the PMC's runcount 2210 * comes down to zero. 2211 */ 2212 while (atomic_load_acq_32(&pm->pm_runcount) > 0) { 2213 #ifdef HWPMC_DEBUG 2214 maxloop--; 2215 KASSERT(maxloop > 0, 2216 ("[pmc,%d] (ri%d, rc%d) waiting too long for " 2217 "pmc to be free", __LINE__, 2218 PMC_TO_ROWINDEX(pm), pm->pm_runcount)); 2219 #endif 2220 pmc_force_context_switch(); 2221 } 2222 } 2223 2224 /* 2225 * This function does the following things: 2226 * 2227 * - detaches the PMC from hardware 2228 * - unlinks all target threads that were attached to it 2229 * - removes the PMC from its owner's list 2230 * - destroys the PMC private mutex 2231 * 2232 * Once this function completes, the given pmc pointer can be freed by 2233 * calling pmc_destroy_pmc_descriptor(). 2234 */ 2235 2236 static void 2237 pmc_release_pmc_descriptor(struct pmc *pm) 2238 { 2239 enum pmc_mode mode; 2240 struct pmc_hw *phw; 2241 u_int adjri, ri, cpu; 2242 struct pmc_owner *po; 2243 struct pmc_binding pb; 2244 struct pmc_process *pp; 2245 struct pmc_classdep *pcd; 2246 struct pmc_target *ptgt, *tmp; 2247 2248 sx_assert(&pmc_sx, SX_XLOCKED); 2249 2250 KASSERT(pm, ("[pmc,%d] null pmc", __LINE__)); 2251 2252 ri = PMC_TO_ROWINDEX(pm); 2253 pcd = pmc_ri_to_classdep(md, ri, &adjri); 2254 mode = PMC_TO_MODE(pm); 2255 2256 PMCDBG3(PMC,REL,1, "release-pmc pmc=%p ri=%d mode=%d", pm, ri, 2257 mode); 2258 2259 /* 2260 * First, we take the PMC off hardware. 2261 */ 2262 cpu = 0; 2263 if (PMC_IS_SYSTEM_MODE(mode)) { 2264 2265 /* 2266 * A system mode PMC runs on a specific CPU. Switch 2267 * to this CPU and turn hardware off. 2268 */ 2269 pmc_save_cpu_binding(&pb); 2270 2271 cpu = PMC_TO_CPU(pm); 2272 2273 pmc_select_cpu(cpu); 2274 2275 /* switch off non-stalled CPUs */ 2276 CPU_CLR_ATOMIC(cpu, &pm->pm_cpustate); 2277 if (pm->pm_state == PMC_STATE_RUNNING && 2278 !CPU_ISSET(cpu, &pm->pm_stalled)) { 2279 2280 phw = pmc_pcpu[cpu]->pc_hwpmcs[ri]; 2281 2282 KASSERT(phw->phw_pmc == pm, 2283 ("[pmc, %d] pmc ptr ri(%d) hw(%p) pm(%p)", 2284 __LINE__, ri, phw->phw_pmc, pm)); 2285 PMCDBG2(PMC,REL,2, "stopping cpu=%d ri=%d", cpu, ri); 2286 2287 critical_enter(); 2288 pcd->pcd_stop_pmc(cpu, adjri); 2289 critical_exit(); 2290 } 2291 2292 PMCDBG2(PMC,REL,2, "decfg cpu=%d ri=%d", cpu, ri); 2293 2294 critical_enter(); 2295 pcd->pcd_config_pmc(cpu, adjri, NULL); 2296 critical_exit(); 2297 2298 /* adjust the global and process count of SS mode PMCs */ 2299 if (mode == PMC_MODE_SS && pm->pm_state == PMC_STATE_RUNNING) { 2300 po = pm->pm_owner; 2301 po->po_sscount--; 2302 if (po->po_sscount == 0) { 2303 atomic_subtract_rel_int(&pmc_ss_count, 1); 2304 LIST_REMOVE(po, po_ssnext); 2305 } 2306 } 2307 2308 pm->pm_state = PMC_STATE_DELETED; 2309 2310 pmc_restore_cpu_binding(&pb); 2311 2312 /* 2313 * We could have references to this PMC structure in 2314 * the per-cpu sample queues. Wait for the queue to 2315 * drain. 2316 */ 2317 pmc_wait_for_pmc_idle(pm); 2318 2319 } else if (PMC_IS_VIRTUAL_MODE(mode)) { 2320 2321 /* 2322 * A virtual PMC could be running on multiple CPUs at 2323 * a given instant. 2324 * 2325 * By marking its state as DELETED, we ensure that 2326 * this PMC is never further scheduled on hardware. 2327 * 2328 * Then we wait till all CPUs are done with this PMC. 2329 */ 2330 pm->pm_state = PMC_STATE_DELETED; 2331 2332 2333 /* Wait for the PMCs runcount to come to zero. */ 2334 pmc_wait_for_pmc_idle(pm); 2335 2336 /* 2337 * At this point the PMC is off all CPUs and cannot be 2338 * freshly scheduled onto a CPU. It is now safe to 2339 * unlink all targets from this PMC. If a 2340 * process-record's refcount falls to zero, we remove 2341 * it from the hash table. The module-wide SX lock 2342 * protects us from races. 2343 */ 2344 LIST_FOREACH_SAFE(ptgt, &pm->pm_targets, pt_next, tmp) { 2345 pp = ptgt->pt_process; 2346 pmc_unlink_target_process(pm, pp); /* frees 'ptgt' */ 2347 2348 PMCDBG1(PMC,REL,3, "pp->refcnt=%d", pp->pp_refcnt); 2349 2350 /* 2351 * If the target process record shows that no 2352 * PMCs are attached to it, reclaim its space. 2353 */ 2354 2355 if (pp->pp_refcnt == 0) { 2356 pmc_remove_process_descriptor(pp); 2357 free(pp, M_PMC); 2358 } 2359 } 2360 2361 cpu = curthread->td_oncpu; /* setup cpu for pmd_release() */ 2362 2363 } 2364 2365 /* 2366 * Release any MD resources 2367 */ 2368 (void) pcd->pcd_release_pmc(cpu, adjri, pm); 2369 2370 /* 2371 * Update row disposition 2372 */ 2373 2374 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) 2375 PMC_UNMARK_ROW_STANDALONE(ri); 2376 else 2377 PMC_UNMARK_ROW_THREAD(ri); 2378 2379 /* unlink from the owner's list */ 2380 if (pm->pm_owner) { 2381 LIST_REMOVE(pm, pm_next); 2382 pm->pm_owner = NULL; 2383 } 2384 } 2385 2386 /* 2387 * Register an owner and a pmc. 2388 */ 2389 2390 static int 2391 pmc_register_owner(struct proc *p, struct pmc *pmc) 2392 { 2393 struct pmc_owner *po; 2394 2395 sx_assert(&pmc_sx, SX_XLOCKED); 2396 2397 if ((po = pmc_find_owner_descriptor(p)) == NULL) 2398 if ((po = pmc_allocate_owner_descriptor(p)) == NULL) 2399 return ENOMEM; 2400 2401 KASSERT(pmc->pm_owner == NULL, 2402 ("[pmc,%d] attempting to own an initialized PMC", __LINE__)); 2403 pmc->pm_owner = po; 2404 2405 LIST_INSERT_HEAD(&po->po_pmcs, pmc, pm_next); 2406 2407 PROC_LOCK(p); 2408 p->p_flag |= P_HWPMC; 2409 PROC_UNLOCK(p); 2410 2411 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 2412 pmclog_process_pmcallocate(pmc); 2413 2414 PMCDBG2(PMC,REG,1, "register-owner pmc-owner=%p pmc=%p", 2415 po, pmc); 2416 2417 return 0; 2418 } 2419 2420 /* 2421 * Return the current row disposition: 2422 * == 0 => FREE 2423 * > 0 => PROCESS MODE 2424 * < 0 => SYSTEM MODE 2425 */ 2426 2427 int 2428 pmc_getrowdisp(int ri) 2429 { 2430 return pmc_pmcdisp[ri]; 2431 } 2432 2433 /* 2434 * Check if a PMC at row index 'ri' can be allocated to the current 2435 * process. 2436 * 2437 * Allocation can fail if: 2438 * - the current process is already being profiled by a PMC at index 'ri', 2439 * attached to it via OP_PMCATTACH. 2440 * - the current process has already allocated a PMC at index 'ri' 2441 * via OP_ALLOCATE. 2442 */ 2443 2444 static int 2445 pmc_can_allocate_rowindex(struct proc *p, unsigned int ri, int cpu) 2446 { 2447 enum pmc_mode mode; 2448 struct pmc *pm; 2449 struct pmc_owner *po; 2450 struct pmc_process *pp; 2451 2452 PMCDBG5(PMC,ALR,1, "can-allocate-rowindex proc=%p (%d, %s) ri=%d " 2453 "cpu=%d", p, p->p_pid, p->p_comm, ri, cpu); 2454 2455 /* 2456 * We shouldn't have already allocated a process-mode PMC at 2457 * row index 'ri'. 2458 * 2459 * We shouldn't have allocated a system-wide PMC on the same 2460 * CPU and same RI. 2461 */ 2462 if ((po = pmc_find_owner_descriptor(p)) != NULL) 2463 LIST_FOREACH(pm, &po->po_pmcs, pm_next) { 2464 if (PMC_TO_ROWINDEX(pm) == ri) { 2465 mode = PMC_TO_MODE(pm); 2466 if (PMC_IS_VIRTUAL_MODE(mode)) 2467 return EEXIST; 2468 if (PMC_IS_SYSTEM_MODE(mode) && 2469 (int) PMC_TO_CPU(pm) == cpu) 2470 return EEXIST; 2471 } 2472 } 2473 2474 /* 2475 * We also shouldn't be the target of any PMC at this index 2476 * since otherwise a PMC_ATTACH to ourselves will fail. 2477 */ 2478 if ((pp = pmc_find_process_descriptor(p, 0)) != NULL) 2479 if (pp->pp_pmcs[ri].pp_pmc) 2480 return EEXIST; 2481 2482 PMCDBG4(PMC,ALR,2, "can-allocate-rowindex proc=%p (%d, %s) ri=%d ok", 2483 p, p->p_pid, p->p_comm, ri); 2484 2485 return 0; 2486 } 2487 2488 /* 2489 * Check if a given PMC at row index 'ri' can be currently used in 2490 * mode 'mode'. 2491 */ 2492 2493 static int 2494 pmc_can_allocate_row(int ri, enum pmc_mode mode) 2495 { 2496 enum pmc_disp disp; 2497 2498 sx_assert(&pmc_sx, SX_XLOCKED); 2499 2500 PMCDBG2(PMC,ALR,1, "can-allocate-row ri=%d mode=%d", ri, mode); 2501 2502 if (PMC_IS_SYSTEM_MODE(mode)) 2503 disp = PMC_DISP_STANDALONE; 2504 else 2505 disp = PMC_DISP_THREAD; 2506 2507 /* 2508 * check disposition for PMC row 'ri': 2509 * 2510 * Expected disposition Row-disposition Result 2511 * 2512 * STANDALONE STANDALONE or FREE proceed 2513 * STANDALONE THREAD fail 2514 * THREAD THREAD or FREE proceed 2515 * THREAD STANDALONE fail 2516 */ 2517 2518 if (!PMC_ROW_DISP_IS_FREE(ri) && 2519 !(disp == PMC_DISP_THREAD && PMC_ROW_DISP_IS_THREAD(ri)) && 2520 !(disp == PMC_DISP_STANDALONE && PMC_ROW_DISP_IS_STANDALONE(ri))) 2521 return EBUSY; 2522 2523 /* 2524 * All OK 2525 */ 2526 2527 PMCDBG2(PMC,ALR,2, "can-allocate-row ri=%d mode=%d ok", ri, mode); 2528 2529 return 0; 2530 2531 } 2532 2533 /* 2534 * Find a PMC descriptor with user handle 'pmcid' for thread 'td'. 2535 */ 2536 2537 static struct pmc * 2538 pmc_find_pmc_descriptor_in_process(struct pmc_owner *po, pmc_id_t pmcid) 2539 { 2540 struct pmc *pm; 2541 2542 KASSERT(PMC_ID_TO_ROWINDEX(pmcid) < md->pmd_npmc, 2543 ("[pmc,%d] Illegal pmc index %d (max %d)", __LINE__, 2544 PMC_ID_TO_ROWINDEX(pmcid), md->pmd_npmc)); 2545 2546 LIST_FOREACH(pm, &po->po_pmcs, pm_next) 2547 if (pm->pm_id == pmcid) 2548 return pm; 2549 2550 return NULL; 2551 } 2552 2553 static int 2554 pmc_find_pmc(pmc_id_t pmcid, struct pmc **pmc) 2555 { 2556 2557 struct pmc *pm, *opm; 2558 struct pmc_owner *po; 2559 struct pmc_process *pp; 2560 2561 KASSERT(PMC_ID_TO_ROWINDEX(pmcid) < md->pmd_npmc, 2562 ("[pmc,%d] Illegal pmc index %d (max %d)", __LINE__, 2563 PMC_ID_TO_ROWINDEX(pmcid), md->pmd_npmc)); 2564 PMCDBG1(PMC,FND,1, "find-pmc id=%d", pmcid); 2565 2566 if ((po = pmc_find_owner_descriptor(curthread->td_proc)) == NULL) { 2567 /* 2568 * In case of PMC_F_DESCENDANTS child processes we will not find 2569 * the current process in the owners hash list. Find the owner 2570 * process first and from there lookup the po. 2571 */ 2572 if ((pp = pmc_find_process_descriptor(curthread->td_proc, 2573 PMC_FLAG_NONE)) == NULL) { 2574 return ESRCH; 2575 } else { 2576 opm = pp->pp_pmcs[PMC_ID_TO_ROWINDEX(pmcid)].pp_pmc; 2577 if (opm == NULL) 2578 return ESRCH; 2579 if ((opm->pm_flags & (PMC_F_ATTACHED_TO_OWNER| 2580 PMC_F_DESCENDANTS)) != (PMC_F_ATTACHED_TO_OWNER| 2581 PMC_F_DESCENDANTS)) 2582 return ESRCH; 2583 po = opm->pm_owner; 2584 } 2585 } 2586 2587 if ((pm = pmc_find_pmc_descriptor_in_process(po, pmcid)) == NULL) 2588 return EINVAL; 2589 2590 PMCDBG2(PMC,FND,2, "find-pmc id=%d -> pmc=%p", pmcid, pm); 2591 2592 *pmc = pm; 2593 return 0; 2594 } 2595 2596 /* 2597 * Start a PMC. 2598 */ 2599 2600 static int 2601 pmc_start(struct pmc *pm) 2602 { 2603 enum pmc_mode mode; 2604 struct pmc_owner *po; 2605 struct pmc_binding pb; 2606 struct pmc_classdep *pcd; 2607 int adjri, error, cpu, ri; 2608 2609 KASSERT(pm != NULL, 2610 ("[pmc,%d] null pm", __LINE__)); 2611 2612 mode = PMC_TO_MODE(pm); 2613 ri = PMC_TO_ROWINDEX(pm); 2614 pcd = pmc_ri_to_classdep(md, ri, &adjri); 2615 2616 error = 0; 2617 2618 PMCDBG3(PMC,OPS,1, "start pmc=%p mode=%d ri=%d", pm, mode, ri); 2619 2620 po = pm->pm_owner; 2621 2622 /* 2623 * Disallow PMCSTART if a logfile is required but has not been 2624 * configured yet. 2625 */ 2626 if ((pm->pm_flags & PMC_F_NEEDS_LOGFILE) && 2627 (po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) 2628 return (EDOOFUS); /* programming error */ 2629 2630 /* 2631 * If this is a sampling mode PMC, log mapping information for 2632 * the kernel modules that are currently loaded. 2633 */ 2634 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 2635 pmc_log_kernel_mappings(pm); 2636 2637 if (PMC_IS_VIRTUAL_MODE(mode)) { 2638 2639 /* 2640 * If a PMCATTACH has never been done on this PMC, 2641 * attach it to its owner process. 2642 */ 2643 2644 if (LIST_EMPTY(&pm->pm_targets)) 2645 error = (pm->pm_flags & PMC_F_ATTACH_DONE) ? ESRCH : 2646 pmc_attach_process(po->po_owner, pm); 2647 2648 /* 2649 * If the PMC is attached to its owner, then force a context 2650 * switch to ensure that the MD state gets set correctly. 2651 */ 2652 2653 if (error == 0) { 2654 pm->pm_state = PMC_STATE_RUNNING; 2655 if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) 2656 pmc_force_context_switch(); 2657 } 2658 2659 return (error); 2660 } 2661 2662 2663 /* 2664 * A system-wide PMC. 2665 * 2666 * Add the owner to the global list if this is a system-wide 2667 * sampling PMC. 2668 */ 2669 2670 if (mode == PMC_MODE_SS) { 2671 if (po->po_sscount == 0) { 2672 LIST_INSERT_HEAD(&pmc_ss_owners, po, po_ssnext); 2673 atomic_add_rel_int(&pmc_ss_count, 1); 2674 PMCDBG1(PMC,OPS,1, "po=%p in global list", po); 2675 } 2676 po->po_sscount++; 2677 2678 /* 2679 * Log mapping information for all existing processes in the 2680 * system. Subsequent mappings are logged as they happen; 2681 * see pmc_process_mmap(). 2682 */ 2683 if (po->po_logprocmaps == 0) { 2684 pmc_log_all_process_mappings(po); 2685 po->po_logprocmaps = 1; 2686 } 2687 } 2688 2689 /* 2690 * Move to the CPU associated with this 2691 * PMC, and start the hardware. 2692 */ 2693 2694 pmc_save_cpu_binding(&pb); 2695 2696 cpu = PMC_TO_CPU(pm); 2697 2698 if (!pmc_cpu_is_active(cpu)) 2699 return (ENXIO); 2700 2701 pmc_select_cpu(cpu); 2702 2703 /* 2704 * global PMCs are configured at allocation time 2705 * so write out the initial value and start the PMC. 2706 */ 2707 2708 pm->pm_state = PMC_STATE_RUNNING; 2709 2710 critical_enter(); 2711 if ((error = pcd->pcd_write_pmc(cpu, adjri, 2712 PMC_IS_SAMPLING_MODE(mode) ? 2713 pm->pm_sc.pm_reloadcount : 2714 pm->pm_sc.pm_initial)) == 0) { 2715 /* If a sampling mode PMC, reset stalled state. */ 2716 if (PMC_IS_SAMPLING_MODE(mode)) 2717 CPU_CLR_ATOMIC(cpu, &pm->pm_stalled); 2718 2719 /* Indicate that we desire this to run. Start it. */ 2720 CPU_SET_ATOMIC(cpu, &pm->pm_cpustate); 2721 error = pcd->pcd_start_pmc(cpu, adjri); 2722 } 2723 critical_exit(); 2724 2725 pmc_restore_cpu_binding(&pb); 2726 2727 return (error); 2728 } 2729 2730 /* 2731 * Stop a PMC. 2732 */ 2733 2734 static int 2735 pmc_stop(struct pmc *pm) 2736 { 2737 struct pmc_owner *po; 2738 struct pmc_binding pb; 2739 struct pmc_classdep *pcd; 2740 int adjri, cpu, error, ri; 2741 2742 KASSERT(pm != NULL, ("[pmc,%d] null pmc", __LINE__)); 2743 2744 PMCDBG3(PMC,OPS,1, "stop pmc=%p mode=%d ri=%d", pm, 2745 PMC_TO_MODE(pm), PMC_TO_ROWINDEX(pm)); 2746 2747 pm->pm_state = PMC_STATE_STOPPED; 2748 2749 /* 2750 * If the PMC is a virtual mode one, changing the state to 2751 * non-RUNNING is enough to ensure that the PMC never gets 2752 * scheduled. 2753 * 2754 * If this PMC is current running on a CPU, then it will 2755 * handled correctly at the time its target process is context 2756 * switched out. 2757 */ 2758 2759 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) 2760 return 0; 2761 2762 /* 2763 * A system-mode PMC. Move to the CPU associated with 2764 * this PMC, and stop the hardware. We update the 2765 * 'initial count' so that a subsequent PMCSTART will 2766 * resume counting from the current hardware count. 2767 */ 2768 2769 pmc_save_cpu_binding(&pb); 2770 2771 cpu = PMC_TO_CPU(pm); 2772 2773 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 2774 ("[pmc,%d] illegal cpu=%d", __LINE__, cpu)); 2775 2776 if (!pmc_cpu_is_active(cpu)) 2777 return ENXIO; 2778 2779 pmc_select_cpu(cpu); 2780 2781 ri = PMC_TO_ROWINDEX(pm); 2782 pcd = pmc_ri_to_classdep(md, ri, &adjri); 2783 2784 CPU_CLR_ATOMIC(cpu, &pm->pm_cpustate); 2785 critical_enter(); 2786 if ((error = pcd->pcd_stop_pmc(cpu, adjri)) == 0) 2787 error = pcd->pcd_read_pmc(cpu, adjri, &pm->pm_sc.pm_initial); 2788 critical_exit(); 2789 2790 pmc_restore_cpu_binding(&pb); 2791 2792 po = pm->pm_owner; 2793 2794 /* remove this owner from the global list of SS PMC owners */ 2795 if (PMC_TO_MODE(pm) == PMC_MODE_SS) { 2796 po->po_sscount--; 2797 if (po->po_sscount == 0) { 2798 atomic_subtract_rel_int(&pmc_ss_count, 1); 2799 LIST_REMOVE(po, po_ssnext); 2800 PMCDBG1(PMC,OPS,2,"po=%p removed from global list", po); 2801 } 2802 } 2803 2804 return (error); 2805 } 2806 2807 2808 #ifdef HWPMC_DEBUG 2809 static const char *pmc_op_to_name[] = { 2810 #undef __PMC_OP 2811 #define __PMC_OP(N, D) #N , 2812 __PMC_OPS() 2813 NULL 2814 }; 2815 #endif 2816 2817 /* 2818 * The syscall interface 2819 */ 2820 2821 #define PMC_GET_SX_XLOCK(...) do { \ 2822 sx_xlock(&pmc_sx); \ 2823 if (pmc_hook == NULL) { \ 2824 sx_xunlock(&pmc_sx); \ 2825 return __VA_ARGS__; \ 2826 } \ 2827 } while (0) 2828 2829 #define PMC_DOWNGRADE_SX() do { \ 2830 sx_downgrade(&pmc_sx); \ 2831 is_sx_downgraded = 1; \ 2832 } while (0) 2833 2834 static int 2835 pmc_syscall_handler(struct thread *td, void *syscall_args) 2836 { 2837 int error, is_sx_downgraded, is_sx_locked, op; 2838 struct pmc_syscall_args *c; 2839 void *arg; 2840 2841 PMC_GET_SX_XLOCK(ENOSYS); 2842 2843 DROP_GIANT(); 2844 2845 is_sx_downgraded = 0; 2846 is_sx_locked = 1; 2847 2848 c = (struct pmc_syscall_args *) syscall_args; 2849 2850 op = c->pmop_code; 2851 arg = c->pmop_data; 2852 2853 PMCDBG3(MOD,PMS,1, "syscall op=%d \"%s\" arg=%p", op, 2854 pmc_op_to_name[op], arg); 2855 2856 error = 0; 2857 atomic_add_int(&pmc_stats.pm_syscalls, 1); 2858 2859 switch(op) 2860 { 2861 2862 2863 /* 2864 * Configure a log file. 2865 * 2866 * XXX This OP will be reworked. 2867 */ 2868 2869 case PMC_OP_CONFIGURELOG: 2870 { 2871 struct proc *p; 2872 struct pmc *pm; 2873 struct pmc_owner *po; 2874 struct pmc_op_configurelog cl; 2875 2876 sx_assert(&pmc_sx, SX_XLOCKED); 2877 2878 if ((error = copyin(arg, &cl, sizeof(cl))) != 0) 2879 break; 2880 2881 /* mark this process as owning a log file */ 2882 p = td->td_proc; 2883 if ((po = pmc_find_owner_descriptor(p)) == NULL) 2884 if ((po = pmc_allocate_owner_descriptor(p)) == NULL) { 2885 error = ENOMEM; 2886 break; 2887 } 2888 2889 /* 2890 * If a valid fd was passed in, try to configure that, 2891 * otherwise if 'fd' was less than zero and there was 2892 * a log file configured, flush its buffers and 2893 * de-configure it. 2894 */ 2895 if (cl.pm_logfd >= 0) { 2896 sx_xunlock(&pmc_sx); 2897 is_sx_locked = 0; 2898 error = pmclog_configure_log(md, po, cl.pm_logfd); 2899 } else if (po->po_flags & PMC_PO_OWNS_LOGFILE) { 2900 pmclog_process_closelog(po); 2901 error = pmclog_close(po); 2902 if (error == 0) { 2903 LIST_FOREACH(pm, &po->po_pmcs, pm_next) 2904 if (pm->pm_flags & PMC_F_NEEDS_LOGFILE && 2905 pm->pm_state == PMC_STATE_RUNNING) 2906 pmc_stop(pm); 2907 error = pmclog_deconfigure_log(po); 2908 } 2909 } else 2910 error = EINVAL; 2911 2912 if (error) 2913 break; 2914 } 2915 break; 2916 2917 /* 2918 * Flush a log file. 2919 */ 2920 2921 case PMC_OP_FLUSHLOG: 2922 { 2923 struct pmc_owner *po; 2924 2925 sx_assert(&pmc_sx, SX_XLOCKED); 2926 2927 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 2928 error = EINVAL; 2929 break; 2930 } 2931 2932 error = pmclog_flush(po); 2933 } 2934 break; 2935 2936 /* 2937 * Close a log file. 2938 */ 2939 2940 case PMC_OP_CLOSELOG: 2941 { 2942 struct pmc_owner *po; 2943 2944 sx_assert(&pmc_sx, SX_XLOCKED); 2945 2946 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 2947 error = EINVAL; 2948 break; 2949 } 2950 2951 error = pmclog_close(po); 2952 } 2953 break; 2954 2955 /* 2956 * Retrieve hardware configuration. 2957 */ 2958 2959 case PMC_OP_GETCPUINFO: /* CPU information */ 2960 { 2961 struct pmc_op_getcpuinfo gci; 2962 struct pmc_classinfo *pci; 2963 struct pmc_classdep *pcd; 2964 int cl; 2965 2966 gci.pm_cputype = md->pmd_cputype; 2967 gci.pm_ncpu = pmc_cpu_max(); 2968 gci.pm_npmc = md->pmd_npmc; 2969 gci.pm_nclass = md->pmd_nclass; 2970 pci = gci.pm_classes; 2971 pcd = md->pmd_classdep; 2972 for (cl = 0; cl < md->pmd_nclass; cl++, pci++, pcd++) { 2973 pci->pm_caps = pcd->pcd_caps; 2974 pci->pm_class = pcd->pcd_class; 2975 pci->pm_width = pcd->pcd_width; 2976 pci->pm_num = pcd->pcd_num; 2977 } 2978 error = copyout(&gci, arg, sizeof(gci)); 2979 } 2980 break; 2981 2982 /* 2983 * Retrieve soft events list. 2984 */ 2985 case PMC_OP_GETDYNEVENTINFO: 2986 { 2987 enum pmc_class cl; 2988 enum pmc_event ev; 2989 struct pmc_op_getdyneventinfo *gei; 2990 struct pmc_dyn_event_descr dev; 2991 struct pmc_soft *ps; 2992 uint32_t nevent; 2993 2994 sx_assert(&pmc_sx, SX_LOCKED); 2995 2996 gei = (struct pmc_op_getdyneventinfo *) arg; 2997 2998 if ((error = copyin(&gei->pm_class, &cl, sizeof(cl))) != 0) 2999 break; 3000 3001 /* Only SOFT class is dynamic. */ 3002 if (cl != PMC_CLASS_SOFT) { 3003 error = EINVAL; 3004 break; 3005 } 3006 3007 nevent = 0; 3008 for (ev = PMC_EV_SOFT_FIRST; (int)ev <= PMC_EV_SOFT_LAST; ev++) { 3009 ps = pmc_soft_ev_acquire(ev); 3010 if (ps == NULL) 3011 continue; 3012 bcopy(&ps->ps_ev, &dev, sizeof(dev)); 3013 pmc_soft_ev_release(ps); 3014 3015 error = copyout(&dev, 3016 &gei->pm_events[nevent], 3017 sizeof(struct pmc_dyn_event_descr)); 3018 if (error != 0) 3019 break; 3020 nevent++; 3021 } 3022 if (error != 0) 3023 break; 3024 3025 error = copyout(&nevent, &gei->pm_nevent, 3026 sizeof(nevent)); 3027 } 3028 break; 3029 3030 /* 3031 * Get module statistics 3032 */ 3033 3034 case PMC_OP_GETDRIVERSTATS: 3035 { 3036 struct pmc_op_getdriverstats gms; 3037 3038 bcopy(&pmc_stats, &gms, sizeof(gms)); 3039 error = copyout(&gms, arg, sizeof(gms)); 3040 } 3041 break; 3042 3043 3044 /* 3045 * Retrieve module version number 3046 */ 3047 3048 case PMC_OP_GETMODULEVERSION: 3049 { 3050 uint32_t cv, modv; 3051 3052 /* retrieve the client's idea of the ABI version */ 3053 if ((error = copyin(arg, &cv, sizeof(uint32_t))) != 0) 3054 break; 3055 /* don't service clients newer than our driver */ 3056 modv = PMC_VERSION; 3057 if ((cv & 0xFFFF0000) > (modv & 0xFFFF0000)) { 3058 error = EPROGMISMATCH; 3059 break; 3060 } 3061 error = copyout(&modv, arg, sizeof(int)); 3062 } 3063 break; 3064 3065 3066 /* 3067 * Retrieve the state of all the PMCs on a given 3068 * CPU. 3069 */ 3070 3071 case PMC_OP_GETPMCINFO: 3072 { 3073 int ari; 3074 struct pmc *pm; 3075 size_t pmcinfo_size; 3076 uint32_t cpu, n, npmc; 3077 struct pmc_owner *po; 3078 struct pmc_binding pb; 3079 struct pmc_classdep *pcd; 3080 struct pmc_info *p, *pmcinfo; 3081 struct pmc_op_getpmcinfo *gpi; 3082 3083 PMC_DOWNGRADE_SX(); 3084 3085 gpi = (struct pmc_op_getpmcinfo *) arg; 3086 3087 if ((error = copyin(&gpi->pm_cpu, &cpu, sizeof(cpu))) != 0) 3088 break; 3089 3090 if (cpu >= pmc_cpu_max()) { 3091 error = EINVAL; 3092 break; 3093 } 3094 3095 if (!pmc_cpu_is_active(cpu)) { 3096 error = ENXIO; 3097 break; 3098 } 3099 3100 /* switch to CPU 'cpu' */ 3101 pmc_save_cpu_binding(&pb); 3102 pmc_select_cpu(cpu); 3103 3104 npmc = md->pmd_npmc; 3105 3106 pmcinfo_size = npmc * sizeof(struct pmc_info); 3107 pmcinfo = malloc(pmcinfo_size, M_PMC, M_WAITOK); 3108 3109 p = pmcinfo; 3110 3111 for (n = 0; n < md->pmd_npmc; n++, p++) { 3112 3113 pcd = pmc_ri_to_classdep(md, n, &ari); 3114 3115 KASSERT(pcd != NULL, 3116 ("[pmc,%d] null pcd ri=%d", __LINE__, n)); 3117 3118 if ((error = pcd->pcd_describe(cpu, ari, p, &pm)) != 0) 3119 break; 3120 3121 if (PMC_ROW_DISP_IS_STANDALONE(n)) 3122 p->pm_rowdisp = PMC_DISP_STANDALONE; 3123 else if (PMC_ROW_DISP_IS_THREAD(n)) 3124 p->pm_rowdisp = PMC_DISP_THREAD; 3125 else 3126 p->pm_rowdisp = PMC_DISP_FREE; 3127 3128 p->pm_ownerpid = -1; 3129 3130 if (pm == NULL) /* no PMC associated */ 3131 continue; 3132 3133 po = pm->pm_owner; 3134 3135 KASSERT(po->po_owner != NULL, 3136 ("[pmc,%d] pmc_owner had a null proc pointer", 3137 __LINE__)); 3138 3139 p->pm_ownerpid = po->po_owner->p_pid; 3140 p->pm_mode = PMC_TO_MODE(pm); 3141 p->pm_event = pm->pm_event; 3142 p->pm_flags = pm->pm_flags; 3143 3144 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 3145 p->pm_reloadcount = 3146 pm->pm_sc.pm_reloadcount; 3147 } 3148 3149 pmc_restore_cpu_binding(&pb); 3150 3151 /* now copy out the PMC info collected */ 3152 if (error == 0) 3153 error = copyout(pmcinfo, &gpi->pm_pmcs, pmcinfo_size); 3154 3155 free(pmcinfo, M_PMC); 3156 } 3157 break; 3158 3159 3160 /* 3161 * Set the administrative state of a PMC. I.e. whether 3162 * the PMC is to be used or not. 3163 */ 3164 3165 case PMC_OP_PMCADMIN: 3166 { 3167 int cpu, ri; 3168 enum pmc_state request; 3169 struct pmc_cpu *pc; 3170 struct pmc_hw *phw; 3171 struct pmc_op_pmcadmin pma; 3172 struct pmc_binding pb; 3173 3174 sx_assert(&pmc_sx, SX_XLOCKED); 3175 3176 KASSERT(td == curthread, 3177 ("[pmc,%d] td != curthread", __LINE__)); 3178 3179 error = priv_check(td, PRIV_PMC_MANAGE); 3180 if (error) 3181 break; 3182 3183 if ((error = copyin(arg, &pma, sizeof(pma))) != 0) 3184 break; 3185 3186 cpu = pma.pm_cpu; 3187 3188 if (cpu < 0 || cpu >= (int) pmc_cpu_max()) { 3189 error = EINVAL; 3190 break; 3191 } 3192 3193 if (!pmc_cpu_is_active(cpu)) { 3194 error = ENXIO; 3195 break; 3196 } 3197 3198 request = pma.pm_state; 3199 3200 if (request != PMC_STATE_DISABLED && 3201 request != PMC_STATE_FREE) { 3202 error = EINVAL; 3203 break; 3204 } 3205 3206 ri = pma.pm_pmc; /* pmc id == row index */ 3207 if (ri < 0 || ri >= (int) md->pmd_npmc) { 3208 error = EINVAL; 3209 break; 3210 } 3211 3212 /* 3213 * We can't disable a PMC with a row-index allocated 3214 * for process virtual PMCs. 3215 */ 3216 3217 if (PMC_ROW_DISP_IS_THREAD(ri) && 3218 request == PMC_STATE_DISABLED) { 3219 error = EBUSY; 3220 break; 3221 } 3222 3223 /* 3224 * otherwise, this PMC on this CPU is either free or 3225 * in system-wide mode. 3226 */ 3227 3228 pmc_save_cpu_binding(&pb); 3229 pmc_select_cpu(cpu); 3230 3231 pc = pmc_pcpu[cpu]; 3232 phw = pc->pc_hwpmcs[ri]; 3233 3234 /* 3235 * XXX do we need some kind of 'forced' disable? 3236 */ 3237 3238 if (phw->phw_pmc == NULL) { 3239 if (request == PMC_STATE_DISABLED && 3240 (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED)) { 3241 phw->phw_state &= ~PMC_PHW_FLAG_IS_ENABLED; 3242 PMC_MARK_ROW_STANDALONE(ri); 3243 } else if (request == PMC_STATE_FREE && 3244 (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0) { 3245 phw->phw_state |= PMC_PHW_FLAG_IS_ENABLED; 3246 PMC_UNMARK_ROW_STANDALONE(ri); 3247 } 3248 /* other cases are a no-op */ 3249 } else 3250 error = EBUSY; 3251 3252 pmc_restore_cpu_binding(&pb); 3253 } 3254 break; 3255 3256 3257 /* 3258 * Allocate a PMC. 3259 */ 3260 3261 case PMC_OP_PMCALLOCATE: 3262 { 3263 int adjri, n; 3264 u_int cpu; 3265 uint32_t caps; 3266 struct pmc *pmc; 3267 enum pmc_mode mode; 3268 struct pmc_hw *phw; 3269 struct pmc_binding pb; 3270 struct pmc_classdep *pcd; 3271 struct pmc_op_pmcallocate pa; 3272 3273 if ((error = copyin(arg, &pa, sizeof(pa))) != 0) 3274 break; 3275 3276 caps = pa.pm_caps; 3277 mode = pa.pm_mode; 3278 cpu = pa.pm_cpu; 3279 3280 if ((mode != PMC_MODE_SS && mode != PMC_MODE_SC && 3281 mode != PMC_MODE_TS && mode != PMC_MODE_TC) || 3282 (cpu != (u_int) PMC_CPU_ANY && cpu >= pmc_cpu_max())) { 3283 error = EINVAL; 3284 break; 3285 } 3286 3287 /* 3288 * Virtual PMCs should only ask for a default CPU. 3289 * System mode PMCs need to specify a non-default CPU. 3290 */ 3291 3292 if ((PMC_IS_VIRTUAL_MODE(mode) && cpu != (u_int) PMC_CPU_ANY) || 3293 (PMC_IS_SYSTEM_MODE(mode) && cpu == (u_int) PMC_CPU_ANY)) { 3294 error = EINVAL; 3295 break; 3296 } 3297 3298 /* 3299 * Check that an inactive CPU is not being asked for. 3300 */ 3301 3302 if (PMC_IS_SYSTEM_MODE(mode) && !pmc_cpu_is_active(cpu)) { 3303 error = ENXIO; 3304 break; 3305 } 3306 3307 /* 3308 * Refuse an allocation for a system-wide PMC if this 3309 * process has been jailed, or if this process lacks 3310 * super-user credentials and the sysctl tunable 3311 * 'security.bsd.unprivileged_syspmcs' is zero. 3312 */ 3313 3314 if (PMC_IS_SYSTEM_MODE(mode)) { 3315 if (jailed(curthread->td_ucred)) { 3316 error = EPERM; 3317 break; 3318 } 3319 if (!pmc_unprivileged_syspmcs) { 3320 error = priv_check(curthread, 3321 PRIV_PMC_SYSTEM); 3322 if (error) 3323 break; 3324 } 3325 } 3326 3327 /* 3328 * Look for valid values for 'pm_flags' 3329 */ 3330 3331 if ((pa.pm_flags & ~(PMC_F_DESCENDANTS | PMC_F_LOG_PROCCSW | 3332 PMC_F_LOG_PROCEXIT | PMC_F_CALLCHAIN)) != 0) { 3333 error = EINVAL; 3334 break; 3335 } 3336 3337 /* process logging options are not allowed for system PMCs */ 3338 if (PMC_IS_SYSTEM_MODE(mode) && (pa.pm_flags & 3339 (PMC_F_LOG_PROCCSW | PMC_F_LOG_PROCEXIT))) { 3340 error = EINVAL; 3341 break; 3342 } 3343 3344 /* 3345 * All sampling mode PMCs need to be able to interrupt the 3346 * CPU. 3347 */ 3348 if (PMC_IS_SAMPLING_MODE(mode)) 3349 caps |= PMC_CAP_INTERRUPT; 3350 3351 /* A valid class specifier should have been passed in. */ 3352 for (n = 0; n < md->pmd_nclass; n++) 3353 if (md->pmd_classdep[n].pcd_class == pa.pm_class) 3354 break; 3355 if (n == md->pmd_nclass) { 3356 error = EINVAL; 3357 break; 3358 } 3359 3360 /* The requested PMC capabilities should be feasible. */ 3361 if ((md->pmd_classdep[n].pcd_caps & caps) != caps) { 3362 error = EOPNOTSUPP; 3363 break; 3364 } 3365 3366 PMCDBG4(PMC,ALL,2, "event=%d caps=0x%x mode=%d cpu=%d", 3367 pa.pm_ev, caps, mode, cpu); 3368 3369 pmc = pmc_allocate_pmc_descriptor(); 3370 pmc->pm_id = PMC_ID_MAKE_ID(cpu,pa.pm_mode,pa.pm_class, 3371 PMC_ID_INVALID); 3372 pmc->pm_event = pa.pm_ev; 3373 pmc->pm_state = PMC_STATE_FREE; 3374 pmc->pm_caps = caps; 3375 pmc->pm_flags = pa.pm_flags; 3376 3377 /* switch thread to CPU 'cpu' */ 3378 pmc_save_cpu_binding(&pb); 3379 3380 #define PMC_IS_SHAREABLE_PMC(cpu, n) \ 3381 (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_state & \ 3382 PMC_PHW_FLAG_IS_SHAREABLE) 3383 #define PMC_IS_UNALLOCATED(cpu, n) \ 3384 (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_pmc == NULL) 3385 3386 if (PMC_IS_SYSTEM_MODE(mode)) { 3387 pmc_select_cpu(cpu); 3388 for (n = 0; n < (int) md->pmd_npmc; n++) { 3389 pcd = pmc_ri_to_classdep(md, n, &adjri); 3390 if (pmc_can_allocate_row(n, mode) == 0 && 3391 pmc_can_allocate_rowindex( 3392 curthread->td_proc, n, cpu) == 0 && 3393 (PMC_IS_UNALLOCATED(cpu, n) || 3394 PMC_IS_SHAREABLE_PMC(cpu, n)) && 3395 pcd->pcd_allocate_pmc(cpu, adjri, pmc, 3396 &pa) == 0) 3397 break; 3398 } 3399 } else { 3400 /* Process virtual mode */ 3401 for (n = 0; n < (int) md->pmd_npmc; n++) { 3402 pcd = pmc_ri_to_classdep(md, n, &adjri); 3403 if (pmc_can_allocate_row(n, mode) == 0 && 3404 pmc_can_allocate_rowindex( 3405 curthread->td_proc, n, 3406 PMC_CPU_ANY) == 0 && 3407 pcd->pcd_allocate_pmc(curthread->td_oncpu, 3408 adjri, pmc, &pa) == 0) 3409 break; 3410 } 3411 } 3412 3413 #undef PMC_IS_UNALLOCATED 3414 #undef PMC_IS_SHAREABLE_PMC 3415 3416 pmc_restore_cpu_binding(&pb); 3417 3418 if (n == (int) md->pmd_npmc) { 3419 pmc_destroy_pmc_descriptor(pmc); 3420 pmc = NULL; 3421 error = EINVAL; 3422 break; 3423 } 3424 3425 /* Fill in the correct value in the ID field */ 3426 pmc->pm_id = PMC_ID_MAKE_ID(cpu,mode,pa.pm_class,n); 3427 3428 PMCDBG5(PMC,ALL,2, "ev=%d class=%d mode=%d n=%d -> pmcid=%x", 3429 pmc->pm_event, pa.pm_class, mode, n, pmc->pm_id); 3430 3431 /* Process mode PMCs with logging enabled need log files */ 3432 if (pmc->pm_flags & (PMC_F_LOG_PROCEXIT | PMC_F_LOG_PROCCSW)) 3433 pmc->pm_flags |= PMC_F_NEEDS_LOGFILE; 3434 3435 /* All system mode sampling PMCs require a log file */ 3436 if (PMC_IS_SAMPLING_MODE(mode) && PMC_IS_SYSTEM_MODE(mode)) 3437 pmc->pm_flags |= PMC_F_NEEDS_LOGFILE; 3438 3439 /* 3440 * Configure global pmc's immediately 3441 */ 3442 3443 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pmc))) { 3444 3445 pmc_save_cpu_binding(&pb); 3446 pmc_select_cpu(cpu); 3447 3448 phw = pmc_pcpu[cpu]->pc_hwpmcs[n]; 3449 pcd = pmc_ri_to_classdep(md, n, &adjri); 3450 3451 if ((phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0 || 3452 (error = pcd->pcd_config_pmc(cpu, adjri, pmc)) != 0) { 3453 (void) pcd->pcd_release_pmc(cpu, adjri, pmc); 3454 pmc_destroy_pmc_descriptor(pmc); 3455 pmc = NULL; 3456 pmc_restore_cpu_binding(&pb); 3457 error = EPERM; 3458 break; 3459 } 3460 3461 pmc_restore_cpu_binding(&pb); 3462 } 3463 3464 pmc->pm_state = PMC_STATE_ALLOCATED; 3465 3466 /* 3467 * mark row disposition 3468 */ 3469 3470 if (PMC_IS_SYSTEM_MODE(mode)) 3471 PMC_MARK_ROW_STANDALONE(n); 3472 else 3473 PMC_MARK_ROW_THREAD(n); 3474 3475 /* 3476 * Register this PMC with the current thread as its owner. 3477 */ 3478 3479 if ((error = 3480 pmc_register_owner(curthread->td_proc, pmc)) != 0) { 3481 pmc_release_pmc_descriptor(pmc); 3482 pmc_destroy_pmc_descriptor(pmc); 3483 pmc = NULL; 3484 break; 3485 } 3486 3487 /* 3488 * Return the allocated index. 3489 */ 3490 3491 pa.pm_pmcid = pmc->pm_id; 3492 3493 error = copyout(&pa, arg, sizeof(pa)); 3494 } 3495 break; 3496 3497 3498 /* 3499 * Attach a PMC to a process. 3500 */ 3501 3502 case PMC_OP_PMCATTACH: 3503 { 3504 struct pmc *pm; 3505 struct proc *p; 3506 struct pmc_op_pmcattach a; 3507 3508 sx_assert(&pmc_sx, SX_XLOCKED); 3509 3510 if ((error = copyin(arg, &a, sizeof(a))) != 0) 3511 break; 3512 3513 if (a.pm_pid < 0) { 3514 error = EINVAL; 3515 break; 3516 } else if (a.pm_pid == 0) 3517 a.pm_pid = td->td_proc->p_pid; 3518 3519 if ((error = pmc_find_pmc(a.pm_pmc, &pm)) != 0) 3520 break; 3521 3522 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) { 3523 error = EINVAL; 3524 break; 3525 } 3526 3527 /* PMCs may be (re)attached only when allocated or stopped */ 3528 if (pm->pm_state == PMC_STATE_RUNNING) { 3529 error = EBUSY; 3530 break; 3531 } else if (pm->pm_state != PMC_STATE_ALLOCATED && 3532 pm->pm_state != PMC_STATE_STOPPED) { 3533 error = EINVAL; 3534 break; 3535 } 3536 3537 /* lookup pid */ 3538 if ((p = pfind(a.pm_pid)) == NULL) { 3539 error = ESRCH; 3540 break; 3541 } 3542 3543 /* 3544 * Ignore processes that are working on exiting. 3545 */ 3546 if (p->p_flag & P_WEXIT) { 3547 error = ESRCH; 3548 PROC_UNLOCK(p); /* pfind() returns a locked process */ 3549 break; 3550 } 3551 3552 /* 3553 * we are allowed to attach a PMC to a process if 3554 * we can debug it. 3555 */ 3556 error = p_candebug(curthread, p); 3557 3558 PROC_UNLOCK(p); 3559 3560 if (error == 0) 3561 error = pmc_attach_process(p, pm); 3562 } 3563 break; 3564 3565 3566 /* 3567 * Detach an attached PMC from a process. 3568 */ 3569 3570 case PMC_OP_PMCDETACH: 3571 { 3572 struct pmc *pm; 3573 struct proc *p; 3574 struct pmc_op_pmcattach a; 3575 3576 if ((error = copyin(arg, &a, sizeof(a))) != 0) 3577 break; 3578 3579 if (a.pm_pid < 0) { 3580 error = EINVAL; 3581 break; 3582 } else if (a.pm_pid == 0) 3583 a.pm_pid = td->td_proc->p_pid; 3584 3585 if ((error = pmc_find_pmc(a.pm_pmc, &pm)) != 0) 3586 break; 3587 3588 if ((p = pfind(a.pm_pid)) == NULL) { 3589 error = ESRCH; 3590 break; 3591 } 3592 3593 /* 3594 * Treat processes that are in the process of exiting 3595 * as if they were not present. 3596 */ 3597 3598 if (p->p_flag & P_WEXIT) 3599 error = ESRCH; 3600 3601 PROC_UNLOCK(p); /* pfind() returns a locked process */ 3602 3603 if (error == 0) 3604 error = pmc_detach_process(p, pm); 3605 } 3606 break; 3607 3608 3609 /* 3610 * Retrieve the MSR number associated with the counter 3611 * 'pmc_id'. This allows processes to directly use RDPMC 3612 * instructions to read their PMCs, without the overhead of a 3613 * system call. 3614 */ 3615 3616 case PMC_OP_PMCGETMSR: 3617 { 3618 int adjri, ri; 3619 struct pmc *pm; 3620 struct pmc_target *pt; 3621 struct pmc_op_getmsr gm; 3622 struct pmc_classdep *pcd; 3623 3624 PMC_DOWNGRADE_SX(); 3625 3626 if ((error = copyin(arg, &gm, sizeof(gm))) != 0) 3627 break; 3628 3629 if ((error = pmc_find_pmc(gm.pm_pmcid, &pm)) != 0) 3630 break; 3631 3632 /* 3633 * The allocated PMC has to be a process virtual PMC, 3634 * i.e., of type MODE_T[CS]. Global PMCs can only be 3635 * read using the PMCREAD operation since they may be 3636 * allocated on a different CPU than the one we could 3637 * be running on at the time of the RDPMC instruction. 3638 * 3639 * The GETMSR operation is not allowed for PMCs that 3640 * are inherited across processes. 3641 */ 3642 3643 if (!PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)) || 3644 (pm->pm_flags & PMC_F_DESCENDANTS)) { 3645 error = EINVAL; 3646 break; 3647 } 3648 3649 /* 3650 * It only makes sense to use a RDPMC (or its 3651 * equivalent instruction on non-x86 architectures) on 3652 * a process that has allocated and attached a PMC to 3653 * itself. Conversely the PMC is only allowed to have 3654 * one process attached to it -- its owner. 3655 */ 3656 3657 if ((pt = LIST_FIRST(&pm->pm_targets)) == NULL || 3658 LIST_NEXT(pt, pt_next) != NULL || 3659 pt->pt_process->pp_proc != pm->pm_owner->po_owner) { 3660 error = EINVAL; 3661 break; 3662 } 3663 3664 ri = PMC_TO_ROWINDEX(pm); 3665 pcd = pmc_ri_to_classdep(md, ri, &adjri); 3666 3667 /* PMC class has no 'GETMSR' support */ 3668 if (pcd->pcd_get_msr == NULL) { 3669 error = ENOSYS; 3670 break; 3671 } 3672 3673 if ((error = (*pcd->pcd_get_msr)(adjri, &gm.pm_msr)) < 0) 3674 break; 3675 3676 if ((error = copyout(&gm, arg, sizeof(gm))) < 0) 3677 break; 3678 3679 /* 3680 * Mark our process as using MSRs. Update machine 3681 * state using a forced context switch. 3682 */ 3683 3684 pt->pt_process->pp_flags |= PMC_PP_ENABLE_MSR_ACCESS; 3685 pmc_force_context_switch(); 3686 3687 } 3688 break; 3689 3690 /* 3691 * Release an allocated PMC 3692 */ 3693 3694 case PMC_OP_PMCRELEASE: 3695 { 3696 pmc_id_t pmcid; 3697 struct pmc *pm; 3698 struct pmc_owner *po; 3699 struct pmc_op_simple sp; 3700 3701 /* 3702 * Find PMC pointer for the named PMC. 3703 * 3704 * Use pmc_release_pmc_descriptor() to switch off the 3705 * PMC, remove all its target threads, and remove the 3706 * PMC from its owner's list. 3707 * 3708 * Remove the owner record if this is the last PMC 3709 * owned. 3710 * 3711 * Free up space. 3712 */ 3713 3714 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 3715 break; 3716 3717 pmcid = sp.pm_pmcid; 3718 3719 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 3720 break; 3721 3722 po = pm->pm_owner; 3723 pmc_release_pmc_descriptor(pm); 3724 pmc_maybe_remove_owner(po); 3725 pmc_destroy_pmc_descriptor(pm); 3726 } 3727 break; 3728 3729 3730 /* 3731 * Read and/or write a PMC. 3732 */ 3733 3734 case PMC_OP_PMCRW: 3735 { 3736 int adjri; 3737 struct pmc *pm; 3738 uint32_t cpu, ri; 3739 pmc_value_t oldvalue; 3740 struct pmc_binding pb; 3741 struct pmc_op_pmcrw prw; 3742 struct pmc_classdep *pcd; 3743 struct pmc_op_pmcrw *pprw; 3744 3745 PMC_DOWNGRADE_SX(); 3746 3747 if ((error = copyin(arg, &prw, sizeof(prw))) != 0) 3748 break; 3749 3750 ri = 0; 3751 PMCDBG2(PMC,OPS,1, "rw id=%d flags=0x%x", prw.pm_pmcid, 3752 prw.pm_flags); 3753 3754 /* must have at least one flag set */ 3755 if ((prw.pm_flags & (PMC_F_OLDVALUE|PMC_F_NEWVALUE)) == 0) { 3756 error = EINVAL; 3757 break; 3758 } 3759 3760 /* locate pmc descriptor */ 3761 if ((error = pmc_find_pmc(prw.pm_pmcid, &pm)) != 0) 3762 break; 3763 3764 /* Can't read a PMC that hasn't been started. */ 3765 if (pm->pm_state != PMC_STATE_ALLOCATED && 3766 pm->pm_state != PMC_STATE_STOPPED && 3767 pm->pm_state != PMC_STATE_RUNNING) { 3768 error = EINVAL; 3769 break; 3770 } 3771 3772 /* writing a new value is allowed only for 'STOPPED' pmcs */ 3773 if (pm->pm_state == PMC_STATE_RUNNING && 3774 (prw.pm_flags & PMC_F_NEWVALUE)) { 3775 error = EBUSY; 3776 break; 3777 } 3778 3779 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) { 3780 3781 /* 3782 * If this PMC is attached to its owner (i.e., 3783 * the process requesting this operation) and 3784 * is running, then attempt to get an 3785 * upto-date reading from hardware for a READ. 3786 * Writes are only allowed when the PMC is 3787 * stopped, so only update the saved value 3788 * field. 3789 * 3790 * If the PMC is not running, or is not 3791 * attached to its owner, read/write to the 3792 * savedvalue field. 3793 */ 3794 3795 ri = PMC_TO_ROWINDEX(pm); 3796 pcd = pmc_ri_to_classdep(md, ri, &adjri); 3797 3798 mtx_pool_lock_spin(pmc_mtxpool, pm); 3799 cpu = curthread->td_oncpu; 3800 3801 if (prw.pm_flags & PMC_F_OLDVALUE) { 3802 if ((pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) && 3803 (pm->pm_state == PMC_STATE_RUNNING)) 3804 error = (*pcd->pcd_read_pmc)(cpu, adjri, 3805 &oldvalue); 3806 else 3807 oldvalue = pm->pm_gv.pm_savedvalue; 3808 } 3809 if (prw.pm_flags & PMC_F_NEWVALUE) 3810 pm->pm_gv.pm_savedvalue = prw.pm_value; 3811 3812 mtx_pool_unlock_spin(pmc_mtxpool, pm); 3813 3814 } else { /* System mode PMCs */ 3815 cpu = PMC_TO_CPU(pm); 3816 ri = PMC_TO_ROWINDEX(pm); 3817 pcd = pmc_ri_to_classdep(md, ri, &adjri); 3818 3819 if (!pmc_cpu_is_active(cpu)) { 3820 error = ENXIO; 3821 break; 3822 } 3823 3824 /* move this thread to CPU 'cpu' */ 3825 pmc_save_cpu_binding(&pb); 3826 pmc_select_cpu(cpu); 3827 3828 critical_enter(); 3829 /* save old value */ 3830 if (prw.pm_flags & PMC_F_OLDVALUE) 3831 if ((error = (*pcd->pcd_read_pmc)(cpu, adjri, 3832 &oldvalue))) 3833 goto error; 3834 /* write out new value */ 3835 if (prw.pm_flags & PMC_F_NEWVALUE) 3836 error = (*pcd->pcd_write_pmc)(cpu, adjri, 3837 prw.pm_value); 3838 error: 3839 critical_exit(); 3840 pmc_restore_cpu_binding(&pb); 3841 if (error) 3842 break; 3843 } 3844 3845 pprw = (struct pmc_op_pmcrw *) arg; 3846 3847 #ifdef HWPMC_DEBUG 3848 if (prw.pm_flags & PMC_F_NEWVALUE) 3849 PMCDBG3(PMC,OPS,2, "rw id=%d new %jx -> old %jx", 3850 ri, prw.pm_value, oldvalue); 3851 else if (prw.pm_flags & PMC_F_OLDVALUE) 3852 PMCDBG2(PMC,OPS,2, "rw id=%d -> old %jx", ri, oldvalue); 3853 #endif 3854 3855 /* return old value if requested */ 3856 if (prw.pm_flags & PMC_F_OLDVALUE) 3857 if ((error = copyout(&oldvalue, &pprw->pm_value, 3858 sizeof(prw.pm_value)))) 3859 break; 3860 3861 } 3862 break; 3863 3864 3865 /* 3866 * Set the sampling rate for a sampling mode PMC and the 3867 * initial count for a counting mode PMC. 3868 */ 3869 3870 case PMC_OP_PMCSETCOUNT: 3871 { 3872 struct pmc *pm; 3873 struct pmc_op_pmcsetcount sc; 3874 3875 PMC_DOWNGRADE_SX(); 3876 3877 if ((error = copyin(arg, &sc, sizeof(sc))) != 0) 3878 break; 3879 3880 if ((error = pmc_find_pmc(sc.pm_pmcid, &pm)) != 0) 3881 break; 3882 3883 if (pm->pm_state == PMC_STATE_RUNNING) { 3884 error = EBUSY; 3885 break; 3886 } 3887 3888 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 3889 pm->pm_sc.pm_reloadcount = sc.pm_count; 3890 else 3891 pm->pm_sc.pm_initial = sc.pm_count; 3892 } 3893 break; 3894 3895 3896 /* 3897 * Start a PMC. 3898 */ 3899 3900 case PMC_OP_PMCSTART: 3901 { 3902 pmc_id_t pmcid; 3903 struct pmc *pm; 3904 struct pmc_op_simple sp; 3905 3906 sx_assert(&pmc_sx, SX_XLOCKED); 3907 3908 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 3909 break; 3910 3911 pmcid = sp.pm_pmcid; 3912 3913 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 3914 break; 3915 3916 KASSERT(pmcid == pm->pm_id, 3917 ("[pmc,%d] pmcid %x != id %x", __LINE__, 3918 pm->pm_id, pmcid)); 3919 3920 if (pm->pm_state == PMC_STATE_RUNNING) /* already running */ 3921 break; 3922 else if (pm->pm_state != PMC_STATE_STOPPED && 3923 pm->pm_state != PMC_STATE_ALLOCATED) { 3924 error = EINVAL; 3925 break; 3926 } 3927 3928 error = pmc_start(pm); 3929 } 3930 break; 3931 3932 3933 /* 3934 * Stop a PMC. 3935 */ 3936 3937 case PMC_OP_PMCSTOP: 3938 { 3939 pmc_id_t pmcid; 3940 struct pmc *pm; 3941 struct pmc_op_simple sp; 3942 3943 PMC_DOWNGRADE_SX(); 3944 3945 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 3946 break; 3947 3948 pmcid = sp.pm_pmcid; 3949 3950 /* 3951 * Mark the PMC as inactive and invoke the MD stop 3952 * routines if needed. 3953 */ 3954 3955 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 3956 break; 3957 3958 KASSERT(pmcid == pm->pm_id, 3959 ("[pmc,%d] pmc id %x != pmcid %x", __LINE__, 3960 pm->pm_id, pmcid)); 3961 3962 if (pm->pm_state == PMC_STATE_STOPPED) /* already stopped */ 3963 break; 3964 else if (pm->pm_state != PMC_STATE_RUNNING) { 3965 error = EINVAL; 3966 break; 3967 } 3968 3969 error = pmc_stop(pm); 3970 } 3971 break; 3972 3973 3974 /* 3975 * Write a user supplied value to the log file. 3976 */ 3977 3978 case PMC_OP_WRITELOG: 3979 { 3980 struct pmc_op_writelog wl; 3981 struct pmc_owner *po; 3982 3983 PMC_DOWNGRADE_SX(); 3984 3985 if ((error = copyin(arg, &wl, sizeof(wl))) != 0) 3986 break; 3987 3988 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 3989 error = EINVAL; 3990 break; 3991 } 3992 3993 if ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) { 3994 error = EINVAL; 3995 break; 3996 } 3997 3998 error = pmclog_process_userlog(po, &wl); 3999 } 4000 break; 4001 4002 4003 default: 4004 error = EINVAL; 4005 break; 4006 } 4007 4008 if (is_sx_locked != 0) { 4009 if (is_sx_downgraded) 4010 sx_sunlock(&pmc_sx); 4011 else 4012 sx_xunlock(&pmc_sx); 4013 } 4014 4015 if (error) 4016 atomic_add_int(&pmc_stats.pm_syscall_errors, 1); 4017 4018 PICKUP_GIANT(); 4019 4020 return error; 4021 } 4022 4023 /* 4024 * Helper functions 4025 */ 4026 4027 4028 /* 4029 * Mark the thread as needing callchain capture and post an AST. The 4030 * actual callchain capture will be done in a context where it is safe 4031 * to take page faults. 4032 */ 4033 4034 static void 4035 pmc_post_callchain_callback(void) 4036 { 4037 struct thread *td; 4038 4039 td = curthread; 4040 4041 /* 4042 * If there is multiple PMCs for the same interrupt ignore new post 4043 */ 4044 if (td->td_pflags & TDP_CALLCHAIN) 4045 return; 4046 4047 /* 4048 * Mark this thread as needing callchain capture. 4049 * `td->td_pflags' will be safe to touch because this thread 4050 * was in user space when it was interrupted. 4051 */ 4052 td->td_pflags |= TDP_CALLCHAIN; 4053 4054 /* 4055 * Don't let this thread migrate between CPUs until callchain 4056 * capture completes. 4057 */ 4058 sched_pin(); 4059 4060 return; 4061 } 4062 4063 /* 4064 * Interrupt processing. 4065 * 4066 * Find a free slot in the per-cpu array of samples and capture the 4067 * current callchain there. If a sample was successfully added, a bit 4068 * is set in mask 'pmc_cpumask' denoting that the DO_SAMPLES hook 4069 * needs to be invoked from the clock handler. 4070 * 4071 * This function is meant to be called from an NMI handler. It cannot 4072 * use any of the locking primitives supplied by the OS. 4073 */ 4074 4075 int 4076 pmc_process_interrupt(int cpu, int ring, struct pmc *pm, struct trapframe *tf, 4077 int inuserspace) 4078 { 4079 int error, callchaindepth; 4080 struct thread *td; 4081 struct pmc_sample *ps; 4082 struct pmc_samplebuffer *psb; 4083 4084 error = 0; 4085 4086 /* 4087 * Allocate space for a sample buffer. 4088 */ 4089 psb = pmc_pcpu[cpu]->pc_sb[ring]; 4090 4091 ps = psb->ps_write; 4092 if (ps->ps_nsamples) { /* in use, reader hasn't caught up */ 4093 CPU_SET_ATOMIC(cpu, &pm->pm_stalled); 4094 atomic_add_int(&pmc_stats.pm_intr_bufferfull, 1); 4095 PMCDBG6(SAM,INT,1,"(spc) cpu=%d pm=%p tf=%p um=%d wr=%d rd=%d", 4096 cpu, pm, (void *) tf, inuserspace, 4097 (int) (psb->ps_write - psb->ps_samples), 4098 (int) (psb->ps_read - psb->ps_samples)); 4099 callchaindepth = 1; 4100 error = ENOMEM; 4101 goto done; 4102 } 4103 4104 4105 /* Fill in entry. */ 4106 PMCDBG6(SAM,INT,1,"cpu=%d pm=%p tf=%p um=%d wr=%d rd=%d", cpu, pm, 4107 (void *) tf, inuserspace, 4108 (int) (psb->ps_write - psb->ps_samples), 4109 (int) (psb->ps_read - psb->ps_samples)); 4110 4111 KASSERT(pm->pm_runcount >= 0, 4112 ("[pmc,%d] pm=%p runcount %d", __LINE__, (void *) pm, 4113 pm->pm_runcount)); 4114 4115 atomic_add_rel_int(&pm->pm_runcount, 1); /* hold onto PMC */ 4116 4117 ps->ps_pmc = pm; 4118 if ((td = curthread) && td->td_proc) 4119 ps->ps_pid = td->td_proc->p_pid; 4120 else 4121 ps->ps_pid = -1; 4122 ps->ps_cpu = cpu; 4123 ps->ps_td = td; 4124 ps->ps_flags = inuserspace ? PMC_CC_F_USERSPACE : 0; 4125 4126 callchaindepth = (pm->pm_flags & PMC_F_CALLCHAIN) ? 4127 pmc_callchaindepth : 1; 4128 4129 if (callchaindepth == 1) 4130 ps->ps_pc[0] = PMC_TRAPFRAME_TO_PC(tf); 4131 else { 4132 /* 4133 * Kernel stack traversals can be done immediately, 4134 * while we defer to an AST for user space traversals. 4135 */ 4136 if (!inuserspace) { 4137 callchaindepth = 4138 pmc_save_kernel_callchain(ps->ps_pc, 4139 callchaindepth, tf); 4140 } else { 4141 pmc_post_callchain_callback(); 4142 callchaindepth = PMC_SAMPLE_INUSE; 4143 } 4144 } 4145 4146 ps->ps_nsamples = callchaindepth; /* mark entry as in use */ 4147 4148 /* increment write pointer, modulo ring buffer size */ 4149 ps++; 4150 if (ps == psb->ps_fence) 4151 psb->ps_write = psb->ps_samples; 4152 else 4153 psb->ps_write = ps; 4154 4155 done: 4156 /* mark CPU as needing processing */ 4157 if (callchaindepth != PMC_SAMPLE_INUSE) 4158 CPU_SET_ATOMIC(cpu, &pmc_cpumask); 4159 4160 return (error); 4161 } 4162 4163 /* 4164 * Capture a user call chain. This function will be called from ast() 4165 * before control returns to userland and before the process gets 4166 * rescheduled. 4167 */ 4168 4169 static void 4170 pmc_capture_user_callchain(int cpu, int ring, struct trapframe *tf) 4171 { 4172 struct pmc *pm; 4173 struct thread *td; 4174 struct pmc_sample *ps, *ps_end; 4175 struct pmc_samplebuffer *psb; 4176 #ifdef INVARIANTS 4177 int ncallchains; 4178 #endif 4179 4180 psb = pmc_pcpu[cpu]->pc_sb[ring]; 4181 td = curthread; 4182 4183 KASSERT(td->td_pflags & TDP_CALLCHAIN, 4184 ("[pmc,%d] Retrieving callchain for thread that doesn't want it", 4185 __LINE__)); 4186 4187 #ifdef INVARIANTS 4188 ncallchains = 0; 4189 #endif 4190 4191 /* 4192 * Iterate through all deferred callchain requests. 4193 * Walk from the current read pointer to the current 4194 * write pointer. 4195 */ 4196 4197 ps = psb->ps_read; 4198 ps_end = psb->ps_write; 4199 do { 4200 if (ps->ps_nsamples != PMC_SAMPLE_INUSE) 4201 goto next; 4202 if (ps->ps_td != td) 4203 goto next; 4204 4205 KASSERT(ps->ps_cpu == cpu, 4206 ("[pmc,%d] cpu mismatch ps_cpu=%d pcpu=%d", __LINE__, 4207 ps->ps_cpu, PCPU_GET(cpuid))); 4208 4209 pm = ps->ps_pmc; 4210 4211 KASSERT(pm->pm_flags & PMC_F_CALLCHAIN, 4212 ("[pmc,%d] Retrieving callchain for PMC that doesn't " 4213 "want it", __LINE__)); 4214 4215 KASSERT(pm->pm_runcount > 0, 4216 ("[pmc,%d] runcount %d", __LINE__, pm->pm_runcount)); 4217 4218 /* 4219 * Retrieve the callchain and mark the sample buffer 4220 * as 'processable' by the timer tick sweep code. 4221 */ 4222 ps->ps_nsamples = pmc_save_user_callchain(ps->ps_pc, 4223 pmc_callchaindepth, tf); 4224 4225 #ifdef INVARIANTS 4226 ncallchains++; 4227 #endif 4228 4229 next: 4230 /* increment the pointer, modulo sample ring size */ 4231 if (++ps == psb->ps_fence) 4232 ps = psb->ps_samples; 4233 } while (ps != ps_end); 4234 4235 KASSERT(ncallchains > 0, 4236 ("[pmc,%d] cpu %d didn't find a sample to collect", __LINE__, 4237 cpu)); 4238 4239 KASSERT(td->td_pinned == 1, 4240 ("[pmc,%d] invalid td_pinned value", __LINE__)); 4241 sched_unpin(); /* Can migrate safely now. */ 4242 4243 /* mark CPU as needing processing */ 4244 CPU_SET_ATOMIC(cpu, &pmc_cpumask); 4245 4246 return; 4247 } 4248 4249 /* 4250 * Process saved PC samples. 4251 */ 4252 4253 static void 4254 pmc_process_samples(int cpu, int ring) 4255 { 4256 struct pmc *pm; 4257 int adjri, n; 4258 struct thread *td; 4259 struct pmc_owner *po; 4260 struct pmc_sample *ps; 4261 struct pmc_classdep *pcd; 4262 struct pmc_samplebuffer *psb; 4263 4264 KASSERT(PCPU_GET(cpuid) == cpu, 4265 ("[pmc,%d] not on the correct CPU pcpu=%d cpu=%d", __LINE__, 4266 PCPU_GET(cpuid), cpu)); 4267 4268 psb = pmc_pcpu[cpu]->pc_sb[ring]; 4269 4270 for (n = 0; n < pmc_nsamples; n++) { /* bound on #iterations */ 4271 4272 ps = psb->ps_read; 4273 if (ps->ps_nsamples == PMC_SAMPLE_FREE) 4274 break; 4275 4276 pm = ps->ps_pmc; 4277 4278 KASSERT(pm->pm_runcount > 0, 4279 ("[pmc,%d] pm=%p runcount %d", __LINE__, (void *) pm, 4280 pm->pm_runcount)); 4281 4282 po = pm->pm_owner; 4283 4284 KASSERT(PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)), 4285 ("[pmc,%d] pmc=%p non-sampling mode=%d", __LINE__, 4286 pm, PMC_TO_MODE(pm))); 4287 4288 /* Ignore PMCs that have been switched off */ 4289 if (pm->pm_state != PMC_STATE_RUNNING) 4290 goto entrydone; 4291 4292 /* If there is a pending AST wait for completion */ 4293 if (ps->ps_nsamples == PMC_SAMPLE_INUSE) { 4294 /* Need a rescan at a later time. */ 4295 CPU_SET_ATOMIC(cpu, &pmc_cpumask); 4296 break; 4297 } 4298 4299 PMCDBG6(SAM,OPS,1,"cpu=%d pm=%p n=%d fl=%x wr=%d rd=%d", cpu, 4300 pm, ps->ps_nsamples, ps->ps_flags, 4301 (int) (psb->ps_write - psb->ps_samples), 4302 (int) (psb->ps_read - psb->ps_samples)); 4303 4304 /* 4305 * If this is a process-mode PMC that is attached to 4306 * its owner, and if the PC is in user mode, update 4307 * profiling statistics like timer-based profiling 4308 * would have done. 4309 */ 4310 if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) { 4311 if (ps->ps_flags & PMC_CC_F_USERSPACE) { 4312 td = FIRST_THREAD_IN_PROC(po->po_owner); 4313 addupc_intr(td, ps->ps_pc[0], 1); 4314 } 4315 goto entrydone; 4316 } 4317 4318 /* 4319 * Otherwise, this is either a sampling mode PMC that 4320 * is attached to a different process than its owner, 4321 * or a system-wide sampling PMC. Dispatch a log 4322 * entry to the PMC's owner process. 4323 */ 4324 pmclog_process_callchain(pm, ps); 4325 4326 entrydone: 4327 ps->ps_nsamples = 0; /* mark entry as free */ 4328 atomic_subtract_rel_int(&pm->pm_runcount, 1); 4329 4330 /* increment read pointer, modulo sample size */ 4331 if (++ps == psb->ps_fence) 4332 psb->ps_read = psb->ps_samples; 4333 else 4334 psb->ps_read = ps; 4335 } 4336 4337 atomic_add_int(&pmc_stats.pm_log_sweeps, 1); 4338 4339 /* Do not re-enable stalled PMCs if we failed to process any samples */ 4340 if (n == 0) 4341 return; 4342 4343 /* 4344 * Restart any stalled sampling PMCs on this CPU. 4345 * 4346 * If the NMI handler sets the pm_stalled field of a PMC after 4347 * the check below, we'll end up processing the stalled PMC at 4348 * the next hardclock tick. 4349 */ 4350 for (n = 0; n < md->pmd_npmc; n++) { 4351 pcd = pmc_ri_to_classdep(md, n, &adjri); 4352 KASSERT(pcd != NULL, 4353 ("[pmc,%d] null pcd ri=%d", __LINE__, n)); 4354 (void) (*pcd->pcd_get_config)(cpu,adjri,&pm); 4355 4356 if (pm == NULL || /* !cfg'ed */ 4357 pm->pm_state != PMC_STATE_RUNNING || /* !active */ 4358 !PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)) || /* !sampling */ 4359 !CPU_ISSET(cpu, &pm->pm_cpustate) || /* !desired */ 4360 !CPU_ISSET(cpu, &pm->pm_stalled)) /* !stalled */ 4361 continue; 4362 4363 CPU_CLR_ATOMIC(cpu, &pm->pm_stalled); 4364 (*pcd->pcd_start_pmc)(cpu, adjri); 4365 } 4366 } 4367 4368 /* 4369 * Event handlers. 4370 */ 4371 4372 /* 4373 * Handle a process exit. 4374 * 4375 * Remove this process from all hash tables. If this process 4376 * owned any PMCs, turn off those PMCs and deallocate them, 4377 * removing any associations with target processes. 4378 * 4379 * This function will be called by the last 'thread' of a 4380 * process. 4381 * 4382 * XXX This eventhandler gets called early in the exit process. 4383 * Consider using a 'hook' invocation from thread_exit() or equivalent 4384 * spot. Another negative is that kse_exit doesn't seem to call 4385 * exit1() [??]. 4386 * 4387 */ 4388 4389 static void 4390 pmc_process_exit(void *arg __unused, struct proc *p) 4391 { 4392 struct pmc *pm; 4393 int adjri, cpu; 4394 unsigned int ri; 4395 int is_using_hwpmcs; 4396 struct pmc_owner *po; 4397 struct pmc_process *pp; 4398 struct pmc_classdep *pcd; 4399 pmc_value_t newvalue, tmp; 4400 4401 PROC_LOCK(p); 4402 is_using_hwpmcs = p->p_flag & P_HWPMC; 4403 PROC_UNLOCK(p); 4404 4405 /* 4406 * Log a sysexit event to all SS PMC owners. 4407 */ 4408 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 4409 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 4410 pmclog_process_sysexit(po, p->p_pid); 4411 4412 if (!is_using_hwpmcs) 4413 return; 4414 4415 PMC_GET_SX_XLOCK(); 4416 PMCDBG3(PRC,EXT,1,"process-exit proc=%p (%d, %s)", p, p->p_pid, 4417 p->p_comm); 4418 4419 /* 4420 * Since this code is invoked by the last thread in an exiting 4421 * process, we would have context switched IN at some prior 4422 * point. However, with PREEMPTION, kernel mode context 4423 * switches may happen any time, so we want to disable a 4424 * context switch OUT till we get any PMCs targetting this 4425 * process off the hardware. 4426 * 4427 * We also need to atomically remove this process' 4428 * entry from our target process hash table, using 4429 * PMC_FLAG_REMOVE. 4430 */ 4431 PMCDBG3(PRC,EXT,1, "process-exit proc=%p (%d, %s)", p, p->p_pid, 4432 p->p_comm); 4433 4434 critical_enter(); /* no preemption */ 4435 4436 cpu = curthread->td_oncpu; 4437 4438 if ((pp = pmc_find_process_descriptor(p, 4439 PMC_FLAG_REMOVE)) != NULL) { 4440 4441 PMCDBG2(PRC,EXT,2, 4442 "process-exit proc=%p pmc-process=%p", p, pp); 4443 4444 /* 4445 * The exiting process could the target of 4446 * some PMCs which will be running on 4447 * currently executing CPU. 4448 * 4449 * We need to turn these PMCs off like we 4450 * would do at context switch OUT time. 4451 */ 4452 for (ri = 0; ri < md->pmd_npmc; ri++) { 4453 4454 /* 4455 * Pick up the pmc pointer from hardware 4456 * state similar to the CSW_OUT code. 4457 */ 4458 pm = NULL; 4459 4460 pcd = pmc_ri_to_classdep(md, ri, &adjri); 4461 4462 (void) (*pcd->pcd_get_config)(cpu, adjri, &pm); 4463 4464 PMCDBG2(PRC,EXT,2, "ri=%d pm=%p", ri, pm); 4465 4466 if (pm == NULL || 4467 !PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) 4468 continue; 4469 4470 PMCDBG4(PRC,EXT,2, "ppmcs[%d]=%p pm=%p " 4471 "state=%d", ri, pp->pp_pmcs[ri].pp_pmc, 4472 pm, pm->pm_state); 4473 4474 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 4475 ("[pmc,%d] ri mismatch pmc(%d) ri(%d)", 4476 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 4477 4478 KASSERT(pm == pp->pp_pmcs[ri].pp_pmc, 4479 ("[pmc,%d] pm %p != pp_pmcs[%d] %p", 4480 __LINE__, pm, ri, pp->pp_pmcs[ri].pp_pmc)); 4481 4482 KASSERT(pm->pm_runcount > 0, 4483 ("[pmc,%d] bad runcount ri %d rc %d", 4484 __LINE__, ri, pm->pm_runcount)); 4485 4486 /* 4487 * Change desired state, and then stop if not 4488 * stalled. This two-step dance should avoid 4489 * race conditions where an interrupt re-enables 4490 * the PMC after this code has already checked 4491 * the pm_stalled flag. 4492 */ 4493 if (CPU_ISSET(cpu, &pm->pm_cpustate)) { 4494 CPU_CLR_ATOMIC(cpu, &pm->pm_cpustate); 4495 if (!CPU_ISSET(cpu, &pm->pm_stalled)) { 4496 (void) pcd->pcd_stop_pmc(cpu, adjri); 4497 pcd->pcd_read_pmc(cpu, adjri, 4498 &newvalue); 4499 tmp = newvalue - 4500 PMC_PCPU_SAVED(cpu,ri); 4501 4502 mtx_pool_lock_spin(pmc_mtxpool, pm); 4503 pm->pm_gv.pm_savedvalue += tmp; 4504 pp->pp_pmcs[ri].pp_pmcval += tmp; 4505 mtx_pool_unlock_spin(pmc_mtxpool, pm); 4506 } 4507 } 4508 4509 atomic_subtract_rel_int(&pm->pm_runcount,1); 4510 4511 KASSERT((int) pm->pm_runcount >= 0, 4512 ("[pmc,%d] runcount is %d", __LINE__, ri)); 4513 4514 (void) pcd->pcd_config_pmc(cpu, adjri, NULL); 4515 } 4516 4517 /* 4518 * Inform the MD layer of this pseudo "context switch 4519 * out" 4520 */ 4521 (void) md->pmd_switch_out(pmc_pcpu[cpu], pp); 4522 4523 critical_exit(); /* ok to be pre-empted now */ 4524 4525 /* 4526 * Unlink this process from the PMCs that are 4527 * targetting it. This will send a signal to 4528 * all PMC owner's whose PMCs are orphaned. 4529 * 4530 * Log PMC value at exit time if requested. 4531 */ 4532 for (ri = 0; ri < md->pmd_npmc; ri++) 4533 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) { 4534 if (pm->pm_flags & PMC_F_NEEDS_LOGFILE && 4535 PMC_IS_COUNTING_MODE(PMC_TO_MODE(pm))) 4536 pmclog_process_procexit(pm, pp); 4537 pmc_unlink_target_process(pm, pp); 4538 } 4539 free(pp, M_PMC); 4540 4541 } else 4542 critical_exit(); /* pp == NULL */ 4543 4544 4545 /* 4546 * If the process owned PMCs, free them up and free up 4547 * memory. 4548 */ 4549 if ((po = pmc_find_owner_descriptor(p)) != NULL) { 4550 pmc_remove_owner(po); 4551 pmc_destroy_owner_descriptor(po); 4552 } 4553 4554 sx_xunlock(&pmc_sx); 4555 } 4556 4557 /* 4558 * Handle a process fork. 4559 * 4560 * If the parent process 'p1' is under HWPMC monitoring, then copy 4561 * over any attached PMCs that have 'do_descendants' semantics. 4562 */ 4563 4564 static void 4565 pmc_process_fork(void *arg __unused, struct proc *p1, struct proc *newproc, 4566 int flags) 4567 { 4568 int is_using_hwpmcs; 4569 unsigned int ri; 4570 uint32_t do_descendants; 4571 struct pmc *pm; 4572 struct pmc_owner *po; 4573 struct pmc_process *ppnew, *ppold; 4574 4575 (void) flags; /* unused parameter */ 4576 4577 PROC_LOCK(p1); 4578 is_using_hwpmcs = p1->p_flag & P_HWPMC; 4579 PROC_UNLOCK(p1); 4580 4581 /* 4582 * If there are system-wide sampling PMCs active, we need to 4583 * log all fork events to their owner's logs. 4584 */ 4585 4586 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 4587 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 4588 pmclog_process_procfork(po, p1->p_pid, newproc->p_pid); 4589 4590 if (!is_using_hwpmcs) 4591 return; 4592 4593 PMC_GET_SX_XLOCK(); 4594 PMCDBG4(PMC,FRK,1, "process-fork proc=%p (%d, %s) -> %p", p1, 4595 p1->p_pid, p1->p_comm, newproc); 4596 4597 /* 4598 * If the parent process (curthread->td_proc) is a 4599 * target of any PMCs, look for PMCs that are to be 4600 * inherited, and link these into the new process 4601 * descriptor. 4602 */ 4603 if ((ppold = pmc_find_process_descriptor(curthread->td_proc, 4604 PMC_FLAG_NONE)) == NULL) 4605 goto done; /* nothing to do */ 4606 4607 do_descendants = 0; 4608 for (ri = 0; ri < md->pmd_npmc; ri++) 4609 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL) 4610 do_descendants |= pm->pm_flags & PMC_F_DESCENDANTS; 4611 if (do_descendants == 0) /* nothing to do */ 4612 goto done; 4613 4614 /* allocate a descriptor for the new process */ 4615 if ((ppnew = pmc_find_process_descriptor(newproc, 4616 PMC_FLAG_ALLOCATE)) == NULL) 4617 goto done; 4618 4619 /* 4620 * Run through all PMCs that were targeting the old process 4621 * and which specified F_DESCENDANTS and attach them to the 4622 * new process. 4623 * 4624 * Log the fork event to all owners of PMCs attached to this 4625 * process, if not already logged. 4626 */ 4627 for (ri = 0; ri < md->pmd_npmc; ri++) 4628 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL && 4629 (pm->pm_flags & PMC_F_DESCENDANTS)) { 4630 pmc_link_target_process(pm, ppnew); 4631 po = pm->pm_owner; 4632 if (po->po_sscount == 0 && 4633 po->po_flags & PMC_PO_OWNS_LOGFILE) 4634 pmclog_process_procfork(po, p1->p_pid, 4635 newproc->p_pid); 4636 } 4637 4638 /* 4639 * Now mark the new process as being tracked by this driver. 4640 */ 4641 PROC_LOCK(newproc); 4642 newproc->p_flag |= P_HWPMC; 4643 PROC_UNLOCK(newproc); 4644 4645 done: 4646 sx_xunlock(&pmc_sx); 4647 } 4648 4649 static void 4650 pmc_kld_load(void *arg __unused, linker_file_t lf) 4651 { 4652 struct pmc_owner *po; 4653 4654 sx_slock(&pmc_sx); 4655 4656 /* 4657 * Notify owners of system sampling PMCs about KLD operations. 4658 */ 4659 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 4660 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 4661 pmclog_process_map_in(po, (pid_t) -1, 4662 (uintfptr_t) lf->address, lf->filename); 4663 4664 /* 4665 * TODO: Notify owners of (all) process-sampling PMCs too. 4666 */ 4667 4668 sx_sunlock(&pmc_sx); 4669 } 4670 4671 static void 4672 pmc_kld_unload(void *arg __unused, const char *filename __unused, 4673 caddr_t address, size_t size) 4674 { 4675 struct pmc_owner *po; 4676 4677 sx_slock(&pmc_sx); 4678 4679 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 4680 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 4681 pmclog_process_map_out(po, (pid_t) -1, 4682 (uintfptr_t) address, (uintfptr_t) address + size); 4683 4684 /* 4685 * TODO: Notify owners of process-sampling PMCs. 4686 */ 4687 4688 sx_sunlock(&pmc_sx); 4689 } 4690 4691 /* 4692 * initialization 4693 */ 4694 static const char * 4695 pmc_name_of_pmcclass(enum pmc_class class) 4696 { 4697 4698 switch (class) { 4699 #undef __PMC_CLASS 4700 #define __PMC_CLASS(S,V,D) \ 4701 case PMC_CLASS_##S: \ 4702 return #S; 4703 __PMC_CLASSES(); 4704 default: 4705 return ("<unknown>"); 4706 } 4707 } 4708 4709 /* 4710 * Base class initializer: allocate structure and set default classes. 4711 */ 4712 struct pmc_mdep * 4713 pmc_mdep_alloc(int nclasses) 4714 { 4715 struct pmc_mdep *md; 4716 int n; 4717 4718 /* SOFT + md classes */ 4719 n = 1 + nclasses; 4720 md = malloc(sizeof(struct pmc_mdep) + n * 4721 sizeof(struct pmc_classdep), M_PMC, M_WAITOK|M_ZERO); 4722 md->pmd_nclass = n; 4723 4724 /* Add base class. */ 4725 pmc_soft_initialize(md); 4726 return md; 4727 } 4728 4729 void 4730 pmc_mdep_free(struct pmc_mdep *md) 4731 { 4732 pmc_soft_finalize(md); 4733 free(md, M_PMC); 4734 } 4735 4736 static int 4737 generic_switch_in(struct pmc_cpu *pc, struct pmc_process *pp) 4738 { 4739 (void) pc; (void) pp; 4740 4741 return (0); 4742 } 4743 4744 static int 4745 generic_switch_out(struct pmc_cpu *pc, struct pmc_process *pp) 4746 { 4747 (void) pc; (void) pp; 4748 4749 return (0); 4750 } 4751 4752 static struct pmc_mdep * 4753 pmc_generic_cpu_initialize(void) 4754 { 4755 struct pmc_mdep *md; 4756 4757 md = pmc_mdep_alloc(0); 4758 4759 md->pmd_cputype = PMC_CPU_GENERIC; 4760 4761 md->pmd_pcpu_init = NULL; 4762 md->pmd_pcpu_fini = NULL; 4763 md->pmd_switch_in = generic_switch_in; 4764 md->pmd_switch_out = generic_switch_out; 4765 4766 return (md); 4767 } 4768 4769 static void 4770 pmc_generic_cpu_finalize(struct pmc_mdep *md) 4771 { 4772 (void) md; 4773 } 4774 4775 4776 static int 4777 pmc_initialize(void) 4778 { 4779 int c, cpu, error, n, ri; 4780 unsigned int maxcpu; 4781 struct pmc_binding pb; 4782 struct pmc_sample *ps; 4783 struct pmc_classdep *pcd; 4784 struct pmc_samplebuffer *sb; 4785 4786 md = NULL; 4787 error = 0; 4788 4789 #ifdef HWPMC_DEBUG 4790 /* parse debug flags first */ 4791 if (TUNABLE_STR_FETCH(PMC_SYSCTL_NAME_PREFIX "debugflags", 4792 pmc_debugstr, sizeof(pmc_debugstr))) 4793 pmc_debugflags_parse(pmc_debugstr, 4794 pmc_debugstr+strlen(pmc_debugstr)); 4795 #endif 4796 4797 PMCDBG1(MOD,INI,0, "PMC Initialize (version %x)", PMC_VERSION); 4798 4799 /* check kernel version */ 4800 if (pmc_kernel_version != PMC_VERSION) { 4801 if (pmc_kernel_version == 0) 4802 printf("hwpmc: this kernel has not been compiled with " 4803 "'options HWPMC_HOOKS'.\n"); 4804 else 4805 printf("hwpmc: kernel version (0x%x) does not match " 4806 "module version (0x%x).\n", pmc_kernel_version, 4807 PMC_VERSION); 4808 return EPROGMISMATCH; 4809 } 4810 4811 /* 4812 * check sysctl parameters 4813 */ 4814 4815 if (pmc_hashsize <= 0) { 4816 (void) printf("hwpmc: tunable \"hashsize\"=%d must be " 4817 "greater than zero.\n", pmc_hashsize); 4818 pmc_hashsize = PMC_HASH_SIZE; 4819 } 4820 4821 if (pmc_nsamples <= 0 || pmc_nsamples > 65535) { 4822 (void) printf("hwpmc: tunable \"nsamples\"=%d out of " 4823 "range.\n", pmc_nsamples); 4824 pmc_nsamples = PMC_NSAMPLES; 4825 } 4826 4827 if (pmc_callchaindepth <= 0 || 4828 pmc_callchaindepth > PMC_CALLCHAIN_DEPTH_MAX) { 4829 (void) printf("hwpmc: tunable \"callchaindepth\"=%d out of " 4830 "range - using %d.\n", pmc_callchaindepth, 4831 PMC_CALLCHAIN_DEPTH_MAX); 4832 pmc_callchaindepth = PMC_CALLCHAIN_DEPTH_MAX; 4833 } 4834 4835 md = pmc_md_initialize(); 4836 if (md == NULL) { 4837 /* Default to generic CPU. */ 4838 md = pmc_generic_cpu_initialize(); 4839 if (md == NULL) 4840 return (ENOSYS); 4841 } 4842 4843 KASSERT(md->pmd_nclass >= 1 && md->pmd_npmc >= 1, 4844 ("[pmc,%d] no classes or pmcs", __LINE__)); 4845 4846 /* Compute the map from row-indices to classdep pointers. */ 4847 pmc_rowindex_to_classdep = malloc(sizeof(struct pmc_classdep *) * 4848 md->pmd_npmc, M_PMC, M_WAITOK|M_ZERO); 4849 4850 for (n = 0; n < md->pmd_npmc; n++) 4851 pmc_rowindex_to_classdep[n] = NULL; 4852 for (ri = c = 0; c < md->pmd_nclass; c++) { 4853 pcd = &md->pmd_classdep[c]; 4854 for (n = 0; n < pcd->pcd_num; n++, ri++) 4855 pmc_rowindex_to_classdep[ri] = pcd; 4856 } 4857 4858 KASSERT(ri == md->pmd_npmc, 4859 ("[pmc,%d] npmc miscomputed: ri=%d, md->npmc=%d", __LINE__, 4860 ri, md->pmd_npmc)); 4861 4862 maxcpu = pmc_cpu_max(); 4863 4864 /* allocate space for the per-cpu array */ 4865 pmc_pcpu = malloc(maxcpu * sizeof(struct pmc_cpu *), M_PMC, 4866 M_WAITOK|M_ZERO); 4867 4868 /* per-cpu 'saved values' for managing process-mode PMCs */ 4869 pmc_pcpu_saved = malloc(sizeof(pmc_value_t) * maxcpu * md->pmd_npmc, 4870 M_PMC, M_WAITOK); 4871 4872 /* Perform CPU-dependent initialization. */ 4873 pmc_save_cpu_binding(&pb); 4874 error = 0; 4875 for (cpu = 0; error == 0 && cpu < maxcpu; cpu++) { 4876 if (!pmc_cpu_is_active(cpu)) 4877 continue; 4878 pmc_select_cpu(cpu); 4879 pmc_pcpu[cpu] = malloc(sizeof(struct pmc_cpu) + 4880 md->pmd_npmc * sizeof(struct pmc_hw *), M_PMC, 4881 M_WAITOK|M_ZERO); 4882 if (md->pmd_pcpu_init) 4883 error = md->pmd_pcpu_init(md, cpu); 4884 for (n = 0; error == 0 && n < md->pmd_nclass; n++) 4885 error = md->pmd_classdep[n].pcd_pcpu_init(md, cpu); 4886 } 4887 pmc_restore_cpu_binding(&pb); 4888 4889 if (error) 4890 return (error); 4891 4892 /* allocate space for the sample array */ 4893 for (cpu = 0; cpu < maxcpu; cpu++) { 4894 if (!pmc_cpu_is_active(cpu)) 4895 continue; 4896 4897 sb = malloc(sizeof(struct pmc_samplebuffer) + 4898 pmc_nsamples * sizeof(struct pmc_sample), M_PMC, 4899 M_WAITOK|M_ZERO); 4900 sb->ps_read = sb->ps_write = sb->ps_samples; 4901 sb->ps_fence = sb->ps_samples + pmc_nsamples; 4902 4903 KASSERT(pmc_pcpu[cpu] != NULL, 4904 ("[pmc,%d] cpu=%d Null per-cpu data", __LINE__, cpu)); 4905 4906 sb->ps_callchains = malloc(pmc_callchaindepth * pmc_nsamples * 4907 sizeof(uintptr_t), M_PMC, M_WAITOK|M_ZERO); 4908 4909 for (n = 0, ps = sb->ps_samples; n < pmc_nsamples; n++, ps++) 4910 ps->ps_pc = sb->ps_callchains + 4911 (n * pmc_callchaindepth); 4912 4913 pmc_pcpu[cpu]->pc_sb[PMC_HR] = sb; 4914 4915 sb = malloc(sizeof(struct pmc_samplebuffer) + 4916 pmc_nsamples * sizeof(struct pmc_sample), M_PMC, 4917 M_WAITOK|M_ZERO); 4918 sb->ps_read = sb->ps_write = sb->ps_samples; 4919 sb->ps_fence = sb->ps_samples + pmc_nsamples; 4920 4921 KASSERT(pmc_pcpu[cpu] != NULL, 4922 ("[pmc,%d] cpu=%d Null per-cpu data", __LINE__, cpu)); 4923 4924 sb->ps_callchains = malloc(pmc_callchaindepth * pmc_nsamples * 4925 sizeof(uintptr_t), M_PMC, M_WAITOK|M_ZERO); 4926 4927 for (n = 0, ps = sb->ps_samples; n < pmc_nsamples; n++, ps++) 4928 ps->ps_pc = sb->ps_callchains + 4929 (n * pmc_callchaindepth); 4930 4931 pmc_pcpu[cpu]->pc_sb[PMC_SR] = sb; 4932 } 4933 4934 /* allocate space for the row disposition array */ 4935 pmc_pmcdisp = malloc(sizeof(enum pmc_mode) * md->pmd_npmc, 4936 M_PMC, M_WAITOK|M_ZERO); 4937 4938 /* mark all PMCs as available */ 4939 for (n = 0; n < (int) md->pmd_npmc; n++) 4940 PMC_MARK_ROW_FREE(n); 4941 4942 /* allocate thread hash tables */ 4943 pmc_ownerhash = hashinit(pmc_hashsize, M_PMC, 4944 &pmc_ownerhashmask); 4945 4946 pmc_processhash = hashinit(pmc_hashsize, M_PMC, 4947 &pmc_processhashmask); 4948 mtx_init(&pmc_processhash_mtx, "pmc-process-hash", "pmc-leaf", 4949 MTX_SPIN); 4950 4951 LIST_INIT(&pmc_ss_owners); 4952 pmc_ss_count = 0; 4953 4954 /* allocate a pool of spin mutexes */ 4955 pmc_mtxpool = mtx_pool_create("pmc-leaf", pmc_mtxpool_size, 4956 MTX_SPIN); 4957 4958 PMCDBG4(MOD,INI,1, "pmc_ownerhash=%p, mask=0x%lx " 4959 "targethash=%p mask=0x%lx", pmc_ownerhash, pmc_ownerhashmask, 4960 pmc_processhash, pmc_processhashmask); 4961 4962 /* register process {exit,fork,exec} handlers */ 4963 pmc_exit_tag = EVENTHANDLER_REGISTER(process_exit, 4964 pmc_process_exit, NULL, EVENTHANDLER_PRI_ANY); 4965 pmc_fork_tag = EVENTHANDLER_REGISTER(process_fork, 4966 pmc_process_fork, NULL, EVENTHANDLER_PRI_ANY); 4967 4968 /* register kld event handlers */ 4969 pmc_kld_load_tag = EVENTHANDLER_REGISTER(kld_load, pmc_kld_load, 4970 NULL, EVENTHANDLER_PRI_ANY); 4971 pmc_kld_unload_tag = EVENTHANDLER_REGISTER(kld_unload, pmc_kld_unload, 4972 NULL, EVENTHANDLER_PRI_ANY); 4973 4974 /* initialize logging */ 4975 pmclog_initialize(); 4976 4977 /* set hook functions */ 4978 pmc_intr = md->pmd_intr; 4979 pmc_hook = pmc_hook_handler; 4980 4981 if (error == 0) { 4982 printf(PMC_MODULE_NAME ":"); 4983 for (n = 0; n < (int) md->pmd_nclass; n++) { 4984 pcd = &md->pmd_classdep[n]; 4985 printf(" %s/%d/%d/0x%b", 4986 pmc_name_of_pmcclass(pcd->pcd_class), 4987 pcd->pcd_num, 4988 pcd->pcd_width, 4989 pcd->pcd_caps, 4990 "\20" 4991 "\1INT\2USR\3SYS\4EDG\5THR" 4992 "\6REA\7WRI\10INV\11QUA\12PRC" 4993 "\13TAG\14CSC"); 4994 } 4995 printf("\n"); 4996 } 4997 4998 return (error); 4999 } 5000 5001 /* prepare to be unloaded */ 5002 static void 5003 pmc_cleanup(void) 5004 { 5005 int c, cpu; 5006 unsigned int maxcpu; 5007 struct pmc_ownerhash *ph; 5008 struct pmc_owner *po, *tmp; 5009 struct pmc_binding pb; 5010 #ifdef HWPMC_DEBUG 5011 struct pmc_processhash *prh; 5012 #endif 5013 5014 PMCDBG0(MOD,INI,0, "cleanup"); 5015 5016 /* switch off sampling */ 5017 CPU_ZERO(&pmc_cpumask); 5018 pmc_intr = NULL; 5019 5020 sx_xlock(&pmc_sx); 5021 if (pmc_hook == NULL) { /* being unloaded already */ 5022 sx_xunlock(&pmc_sx); 5023 return; 5024 } 5025 5026 pmc_hook = NULL; /* prevent new threads from entering module */ 5027 5028 /* deregister event handlers */ 5029 EVENTHANDLER_DEREGISTER(process_fork, pmc_fork_tag); 5030 EVENTHANDLER_DEREGISTER(process_exit, pmc_exit_tag); 5031 EVENTHANDLER_DEREGISTER(kld_load, pmc_kld_load_tag); 5032 EVENTHANDLER_DEREGISTER(kld_unload, pmc_kld_unload_tag); 5033 5034 /* send SIGBUS to all owner threads, free up allocations */ 5035 if (pmc_ownerhash) 5036 for (ph = pmc_ownerhash; 5037 ph <= &pmc_ownerhash[pmc_ownerhashmask]; 5038 ph++) { 5039 LIST_FOREACH_SAFE(po, ph, po_next, tmp) { 5040 pmc_remove_owner(po); 5041 5042 /* send SIGBUS to owner processes */ 5043 PMCDBG3(MOD,INI,2, "cleanup signal proc=%p " 5044 "(%d, %s)", po->po_owner, 5045 po->po_owner->p_pid, 5046 po->po_owner->p_comm); 5047 5048 PROC_LOCK(po->po_owner); 5049 kern_psignal(po->po_owner, SIGBUS); 5050 PROC_UNLOCK(po->po_owner); 5051 5052 pmc_destroy_owner_descriptor(po); 5053 } 5054 } 5055 5056 /* reclaim allocated data structures */ 5057 if (pmc_mtxpool) 5058 mtx_pool_destroy(&pmc_mtxpool); 5059 5060 mtx_destroy(&pmc_processhash_mtx); 5061 if (pmc_processhash) { 5062 #ifdef HWPMC_DEBUG 5063 struct pmc_process *pp; 5064 5065 PMCDBG0(MOD,INI,3, "destroy process hash"); 5066 for (prh = pmc_processhash; 5067 prh <= &pmc_processhash[pmc_processhashmask]; 5068 prh++) 5069 LIST_FOREACH(pp, prh, pp_next) 5070 PMCDBG1(MOD,INI,3, "pid=%d", pp->pp_proc->p_pid); 5071 #endif 5072 5073 hashdestroy(pmc_processhash, M_PMC, pmc_processhashmask); 5074 pmc_processhash = NULL; 5075 } 5076 5077 if (pmc_ownerhash) { 5078 PMCDBG0(MOD,INI,3, "destroy owner hash"); 5079 hashdestroy(pmc_ownerhash, M_PMC, pmc_ownerhashmask); 5080 pmc_ownerhash = NULL; 5081 } 5082 5083 KASSERT(LIST_EMPTY(&pmc_ss_owners), 5084 ("[pmc,%d] Global SS owner list not empty", __LINE__)); 5085 KASSERT(pmc_ss_count == 0, 5086 ("[pmc,%d] Global SS count not empty", __LINE__)); 5087 5088 /* do processor and pmc-class dependent cleanup */ 5089 maxcpu = pmc_cpu_max(); 5090 5091 PMCDBG0(MOD,INI,3, "md cleanup"); 5092 if (md) { 5093 pmc_save_cpu_binding(&pb); 5094 for (cpu = 0; cpu < maxcpu; cpu++) { 5095 PMCDBG2(MOD,INI,1,"pmc-cleanup cpu=%d pcs=%p", 5096 cpu, pmc_pcpu[cpu]); 5097 if (!pmc_cpu_is_active(cpu) || pmc_pcpu[cpu] == NULL) 5098 continue; 5099 pmc_select_cpu(cpu); 5100 for (c = 0; c < md->pmd_nclass; c++) 5101 md->pmd_classdep[c].pcd_pcpu_fini(md, cpu); 5102 if (md->pmd_pcpu_fini) 5103 md->pmd_pcpu_fini(md, cpu); 5104 } 5105 5106 if (md->pmd_cputype == PMC_CPU_GENERIC) 5107 pmc_generic_cpu_finalize(md); 5108 else 5109 pmc_md_finalize(md); 5110 5111 pmc_mdep_free(md); 5112 md = NULL; 5113 pmc_restore_cpu_binding(&pb); 5114 } 5115 5116 /* Free per-cpu descriptors. */ 5117 for (cpu = 0; cpu < maxcpu; cpu++) { 5118 if (!pmc_cpu_is_active(cpu)) 5119 continue; 5120 KASSERT(pmc_pcpu[cpu]->pc_sb[PMC_HR] != NULL, 5121 ("[pmc,%d] Null hw cpu sample buffer cpu=%d", __LINE__, 5122 cpu)); 5123 KASSERT(pmc_pcpu[cpu]->pc_sb[PMC_SR] != NULL, 5124 ("[pmc,%d] Null sw cpu sample buffer cpu=%d", __LINE__, 5125 cpu)); 5126 free(pmc_pcpu[cpu]->pc_sb[PMC_HR]->ps_callchains, M_PMC); 5127 free(pmc_pcpu[cpu]->pc_sb[PMC_HR], M_PMC); 5128 free(pmc_pcpu[cpu]->pc_sb[PMC_SR]->ps_callchains, M_PMC); 5129 free(pmc_pcpu[cpu]->pc_sb[PMC_SR], M_PMC); 5130 free(pmc_pcpu[cpu], M_PMC); 5131 } 5132 5133 free(pmc_pcpu, M_PMC); 5134 pmc_pcpu = NULL; 5135 5136 free(pmc_pcpu_saved, M_PMC); 5137 pmc_pcpu_saved = NULL; 5138 5139 if (pmc_pmcdisp) { 5140 free(pmc_pmcdisp, M_PMC); 5141 pmc_pmcdisp = NULL; 5142 } 5143 5144 if (pmc_rowindex_to_classdep) { 5145 free(pmc_rowindex_to_classdep, M_PMC); 5146 pmc_rowindex_to_classdep = NULL; 5147 } 5148 5149 pmclog_shutdown(); 5150 5151 sx_xunlock(&pmc_sx); /* we are done */ 5152 } 5153 5154 /* 5155 * The function called at load/unload. 5156 */ 5157 5158 static int 5159 load (struct module *module __unused, int cmd, void *arg __unused) 5160 { 5161 int error; 5162 5163 error = 0; 5164 5165 switch (cmd) { 5166 case MOD_LOAD : 5167 /* initialize the subsystem */ 5168 error = pmc_initialize(); 5169 if (error != 0) 5170 break; 5171 PMCDBG2(MOD,INI,1, "syscall=%d maxcpu=%d", 5172 pmc_syscall_num, pmc_cpu_max()); 5173 break; 5174 5175 5176 case MOD_UNLOAD : 5177 case MOD_SHUTDOWN: 5178 pmc_cleanup(); 5179 PMCDBG0(MOD,INI,1, "unloaded"); 5180 break; 5181 5182 default : 5183 error = EINVAL; /* XXX should panic(9) */ 5184 break; 5185 } 5186 5187 return error; 5188 } 5189 5190 /* memory pool */ 5191 MALLOC_DEFINE(M_PMC, "pmc", "Memory space for the PMC module"); 5192