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 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 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 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 PMCDBG(CPU,BND,2, "%s", "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 PMCDBG(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 PMCDBG(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 PMCDBG(CPU,BND,2, "%s", "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 PMCDBG(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 PMCDBG(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 PMCDBG(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 PMCDBG(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 PMCDBG(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 PMCDBG(PRC,TLK,1, "link-target pmc=%p ri=%d pmc-process=%p", 817 pm, ri, pp); 818 819 #ifdef 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 PMCDBG(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 PMCDBG(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 PMCDBG(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 PMCDBG(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 PMCDBG(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 PMCDBG(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 PMCDBG(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 PMCDBG(CSW,SWI,1,"cpu=%d ri=%d new=%jd", cpu, ri, newvalue); 1299 1300 pcd->pcd_write_pmc(cpu, adjri, newvalue); 1301 pcd->pcd_start_pmc(cpu, adjri); 1302 } 1303 1304 /* 1305 * perform any other architecture/cpu dependent thread 1306 * switch-in actions. 1307 */ 1308 1309 (void) (*md->pmd_switch_in)(pc, pp); 1310 1311 critical_exit(); 1312 1313 } 1314 1315 /* 1316 * Thread context switch OUT. 1317 */ 1318 1319 static void 1320 pmc_process_csw_out(struct thread *td) 1321 { 1322 int cpu; 1323 int64_t tmp; 1324 struct pmc *pm; 1325 struct proc *p; 1326 enum pmc_mode mode; 1327 struct pmc_cpu *pc; 1328 pmc_value_t newvalue; 1329 unsigned int adjri, ri; 1330 struct pmc_process *pp; 1331 struct pmc_classdep *pcd; 1332 1333 1334 /* 1335 * Locate our process descriptor; this may be NULL if 1336 * this process is exiting and we have already removed 1337 * the process from the target process table. 1338 * 1339 * Note that due to kernel preemption, multiple 1340 * context switches may happen while the process is 1341 * exiting. 1342 * 1343 * Note also that if the target process cannot be 1344 * found we still need to deconfigure any PMCs that 1345 * are currently running on hardware. 1346 */ 1347 1348 p = td->td_proc; 1349 pp = pmc_find_process_descriptor(p, PMC_FLAG_NONE); 1350 1351 /* 1352 * save PMCs 1353 */ 1354 1355 critical_enter(); 1356 1357 cpu = PCPU_GET(cpuid); /* td->td_oncpu is invalid */ 1358 1359 PMCDBG(CSW,SWO,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p, 1360 p->p_pid, p->p_comm, pp); 1361 1362 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 1363 ("[pmc,%d wierd CPU id %d", __LINE__, cpu)); 1364 1365 pc = pmc_pcpu[cpu]; 1366 1367 /* 1368 * When a PMC gets unlinked from a target PMC, it will 1369 * be removed from the target's pp_pmc[] array. 1370 * 1371 * However, on a MP system, the target could have been 1372 * executing on another CPU at the time of the unlink. 1373 * So, at context switch OUT time, we need to look at 1374 * the hardware to determine if a PMC is scheduled on 1375 * it. 1376 */ 1377 1378 for (ri = 0; ri < md->pmd_npmc; ri++) { 1379 1380 pcd = pmc_ri_to_classdep(md, ri, &adjri); 1381 pm = NULL; 1382 (void) (*pcd->pcd_get_config)(cpu, adjri, &pm); 1383 1384 if (pm == NULL) /* nothing at this row index */ 1385 continue; 1386 1387 mode = PMC_TO_MODE(pm); 1388 if (!PMC_IS_VIRTUAL_MODE(mode)) 1389 continue; /* not a process virtual PMC */ 1390 1391 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 1392 ("[pmc,%d] ri mismatch pmc(%d) ri(%d)", 1393 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 1394 1395 /* Stop hardware if not already stopped */ 1396 if (pm->pm_stalled == 0) 1397 pcd->pcd_stop_pmc(cpu, adjri); 1398 1399 /* reduce this PMC's runcount */ 1400 atomic_subtract_rel_int(&pm->pm_runcount, 1); 1401 1402 /* 1403 * If this PMC is associated with this process, 1404 * save the reading. 1405 */ 1406 1407 if (pp != NULL && pp->pp_pmcs[ri].pp_pmc != NULL) { 1408 1409 KASSERT(pm == pp->pp_pmcs[ri].pp_pmc, 1410 ("[pmc,%d] pm %p != pp_pmcs[%d] %p", __LINE__, 1411 pm, ri, pp->pp_pmcs[ri].pp_pmc)); 1412 1413 KASSERT(pp->pp_refcnt > 0, 1414 ("[pmc,%d] pp refcnt = %d", __LINE__, 1415 pp->pp_refcnt)); 1416 1417 pcd->pcd_read_pmc(cpu, adjri, &newvalue); 1418 1419 tmp = newvalue - PMC_PCPU_SAVED(cpu,ri); 1420 1421 PMCDBG(CSW,SWO,1,"cpu=%d ri=%d tmp=%jd", cpu, ri, 1422 tmp); 1423 1424 if (mode == PMC_MODE_TS) { 1425 1426 /* 1427 * For sampling process-virtual PMCs, 1428 * we expect the count to be 1429 * decreasing as the 'value' 1430 * programmed into the PMC is the 1431 * number of events to be seen till 1432 * the next sampling interrupt. 1433 */ 1434 if (tmp < 0) 1435 tmp += pm->pm_sc.pm_reloadcount; 1436 mtx_pool_lock_spin(pmc_mtxpool, pm); 1437 pp->pp_pmcs[ri].pp_pmcval -= tmp; 1438 if ((int64_t) pp->pp_pmcs[ri].pp_pmcval < 0) 1439 pp->pp_pmcs[ri].pp_pmcval += 1440 pm->pm_sc.pm_reloadcount; 1441 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1442 1443 } else { 1444 1445 /* 1446 * For counting process-virtual PMCs, 1447 * we expect the count to be 1448 * increasing monotonically, modulo a 64 1449 * bit wraparound. 1450 */ 1451 KASSERT((int64_t) tmp >= 0, 1452 ("[pmc,%d] negative increment cpu=%d " 1453 "ri=%d newvalue=%jx saved=%jx " 1454 "incr=%jx", __LINE__, cpu, ri, 1455 newvalue, PMC_PCPU_SAVED(cpu,ri), tmp)); 1456 1457 mtx_pool_lock_spin(pmc_mtxpool, pm); 1458 pm->pm_gv.pm_savedvalue += tmp; 1459 pp->pp_pmcs[ri].pp_pmcval += tmp; 1460 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1461 1462 if (pm->pm_flags & PMC_F_LOG_PROCCSW) 1463 pmclog_process_proccsw(pm, pp, tmp); 1464 } 1465 } 1466 1467 /* mark hardware as free */ 1468 pcd->pcd_config_pmc(cpu, adjri, NULL); 1469 } 1470 1471 /* 1472 * perform any other architecture/cpu dependent thread 1473 * switch out functions. 1474 */ 1475 1476 (void) (*md->pmd_switch_out)(pc, pp); 1477 1478 critical_exit(); 1479 } 1480 1481 /* 1482 * A mapping change for a process. 1483 */ 1484 1485 static void 1486 pmc_process_mmap(struct thread *td, struct pmckern_map_in *pkm) 1487 { 1488 int ri; 1489 pid_t pid; 1490 char *fullpath, *freepath; 1491 const struct pmc *pm; 1492 struct pmc_owner *po; 1493 const struct pmc_process *pp; 1494 1495 freepath = fullpath = NULL; 1496 pmc_getfilename((struct vnode *) pkm->pm_file, &fullpath, &freepath); 1497 1498 pid = td->td_proc->p_pid; 1499 1500 /* Inform owners of all system-wide sampling PMCs. */ 1501 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1502 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1503 pmclog_process_map_in(po, pid, pkm->pm_address, fullpath); 1504 1505 if ((pp = pmc_find_process_descriptor(td->td_proc, 0)) == NULL) 1506 goto done; 1507 1508 /* 1509 * Inform sampling PMC owners tracking this process. 1510 */ 1511 for (ri = 0; ri < md->pmd_npmc; ri++) 1512 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL && 1513 PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 1514 pmclog_process_map_in(pm->pm_owner, 1515 pid, pkm->pm_address, fullpath); 1516 1517 done: 1518 if (freepath) 1519 free(freepath, M_TEMP); 1520 } 1521 1522 1523 /* 1524 * Log an munmap request. 1525 */ 1526 1527 static void 1528 pmc_process_munmap(struct thread *td, struct pmckern_map_out *pkm) 1529 { 1530 int ri; 1531 pid_t pid; 1532 struct pmc_owner *po; 1533 const struct pmc *pm; 1534 const struct pmc_process *pp; 1535 1536 pid = td->td_proc->p_pid; 1537 1538 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1539 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1540 pmclog_process_map_out(po, pid, pkm->pm_address, 1541 pkm->pm_address + pkm->pm_size); 1542 1543 if ((pp = pmc_find_process_descriptor(td->td_proc, 0)) == NULL) 1544 return; 1545 1546 for (ri = 0; ri < md->pmd_npmc; ri++) 1547 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL && 1548 PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 1549 pmclog_process_map_out(pm->pm_owner, pid, 1550 pkm->pm_address, pkm->pm_address + pkm->pm_size); 1551 } 1552 1553 /* 1554 * Log mapping information about the kernel. 1555 */ 1556 1557 static void 1558 pmc_log_kernel_mappings(struct pmc *pm) 1559 { 1560 struct pmc_owner *po; 1561 struct pmckern_map_in *km, *kmbase; 1562 1563 sx_assert(&pmc_sx, SX_LOCKED); 1564 KASSERT(PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)), 1565 ("[pmc,%d] non-sampling PMC (%p) desires mapping information", 1566 __LINE__, (void *) pm)); 1567 1568 po = pm->pm_owner; 1569 1570 if (po->po_flags & PMC_PO_INITIAL_MAPPINGS_DONE) 1571 return; 1572 1573 /* 1574 * Log the current set of kernel modules. 1575 */ 1576 kmbase = linker_hwpmc_list_objects(); 1577 for (km = kmbase; km->pm_file != NULL; km++) { 1578 PMCDBG(LOG,REG,1,"%s %p", (char *) km->pm_file, 1579 (void *) km->pm_address); 1580 pmclog_process_map_in(po, (pid_t) -1, km->pm_address, 1581 km->pm_file); 1582 } 1583 free(kmbase, M_LINKER); 1584 1585 po->po_flags |= PMC_PO_INITIAL_MAPPINGS_DONE; 1586 } 1587 1588 /* 1589 * Log the mappings for a single process. 1590 */ 1591 1592 static void 1593 pmc_log_process_mappings(struct pmc_owner *po, struct proc *p) 1594 { 1595 vm_map_t map; 1596 struct vnode *vp; 1597 struct vmspace *vm; 1598 vm_map_entry_t entry; 1599 vm_offset_t last_end; 1600 u_int last_timestamp; 1601 struct vnode *last_vp; 1602 vm_offset_t start_addr; 1603 vm_object_t obj, lobj, tobj; 1604 char *fullpath, *freepath; 1605 1606 last_vp = NULL; 1607 last_end = (vm_offset_t) 0; 1608 fullpath = freepath = NULL; 1609 1610 if ((vm = vmspace_acquire_ref(p)) == NULL) 1611 return; 1612 1613 map = &vm->vm_map; 1614 vm_map_lock_read(map); 1615 1616 for (entry = map->header.next; entry != &map->header; entry = entry->next) { 1617 1618 if (entry == NULL) { 1619 PMCDBG(LOG,OPS,2, "hwpmc: vm_map entry unexpectedly " 1620 "NULL! pid=%d vm_map=%p\n", p->p_pid, map); 1621 break; 1622 } 1623 1624 /* 1625 * We only care about executable map entries. 1626 */ 1627 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) || 1628 !(entry->protection & VM_PROT_EXECUTE) || 1629 (entry->object.vm_object == NULL)) { 1630 continue; 1631 } 1632 1633 obj = entry->object.vm_object; 1634 VM_OBJECT_RLOCK(obj); 1635 1636 /* 1637 * Walk the backing_object list to find the base 1638 * (non-shadowed) vm_object. 1639 */ 1640 for (lobj = tobj = obj; tobj != NULL; tobj = tobj->backing_object) { 1641 if (tobj != obj) 1642 VM_OBJECT_RLOCK(tobj); 1643 if (lobj != obj) 1644 VM_OBJECT_RUNLOCK(lobj); 1645 lobj = tobj; 1646 } 1647 1648 /* 1649 * At this point lobj is the base vm_object and it is locked. 1650 */ 1651 if (lobj == NULL) { 1652 PMCDBG(LOG,OPS,2, "hwpmc: lobj unexpectedly NULL! pid=%d " 1653 "vm_map=%p vm_obj=%p\n", p->p_pid, map, obj); 1654 VM_OBJECT_RUNLOCK(obj); 1655 continue; 1656 } 1657 1658 if (lobj->type != OBJT_VNODE || lobj->handle == NULL) { 1659 if (lobj != obj) 1660 VM_OBJECT_RUNLOCK(lobj); 1661 VM_OBJECT_RUNLOCK(obj); 1662 continue; 1663 } 1664 1665 /* 1666 * Skip contiguous regions that point to the same 1667 * vnode, so we don't emit redundant MAP-IN 1668 * directives. 1669 */ 1670 if (entry->start == last_end && lobj->handle == last_vp) { 1671 last_end = entry->end; 1672 if (lobj != obj) 1673 VM_OBJECT_RUNLOCK(lobj); 1674 VM_OBJECT_RUNLOCK(obj); 1675 continue; 1676 } 1677 1678 /* 1679 * We don't want to keep the proc's vm_map or this 1680 * vm_object locked while we walk the pathname, since 1681 * vn_fullpath() can sleep. However, if we drop the 1682 * lock, it's possible for concurrent activity to 1683 * modify the vm_map list. To protect against this, 1684 * we save the vm_map timestamp before we release the 1685 * lock, and check it after we reacquire the lock 1686 * below. 1687 */ 1688 start_addr = entry->start; 1689 last_end = entry->end; 1690 last_timestamp = map->timestamp; 1691 vm_map_unlock_read(map); 1692 1693 vp = lobj->handle; 1694 vref(vp); 1695 if (lobj != obj) 1696 VM_OBJECT_RUNLOCK(lobj); 1697 1698 VM_OBJECT_RUNLOCK(obj); 1699 1700 freepath = NULL; 1701 pmc_getfilename(vp, &fullpath, &freepath); 1702 last_vp = vp; 1703 1704 vrele(vp); 1705 1706 vp = NULL; 1707 pmclog_process_map_in(po, p->p_pid, start_addr, fullpath); 1708 if (freepath) 1709 free(freepath, M_TEMP); 1710 1711 vm_map_lock_read(map); 1712 1713 /* 1714 * If our saved timestamp doesn't match, this means 1715 * that the vm_map was modified out from under us and 1716 * we can't trust our current "entry" pointer. Do a 1717 * new lookup for this entry. If there is no entry 1718 * for this address range, vm_map_lookup_entry() will 1719 * return the previous one, so we always want to go to 1720 * entry->next on the next loop iteration. 1721 * 1722 * There is an edge condition here that can occur if 1723 * there is no entry at or before this address. In 1724 * this situation, vm_map_lookup_entry returns 1725 * &map->header, which would cause our loop to abort 1726 * without processing the rest of the map. However, 1727 * in practice this will never happen for process 1728 * vm_map. This is because the executable's text 1729 * segment is the first mapping in the proc's address 1730 * space, and this mapping is never removed until the 1731 * process exits, so there will always be a non-header 1732 * entry at or before the requested address for 1733 * vm_map_lookup_entry to return. 1734 */ 1735 if (map->timestamp != last_timestamp) 1736 vm_map_lookup_entry(map, last_end - 1, &entry); 1737 } 1738 1739 vm_map_unlock_read(map); 1740 vmspace_free(vm); 1741 return; 1742 } 1743 1744 /* 1745 * Log mappings for all processes in the system. 1746 */ 1747 1748 static void 1749 pmc_log_all_process_mappings(struct pmc_owner *po) 1750 { 1751 struct proc *p, *top; 1752 1753 sx_assert(&pmc_sx, SX_XLOCKED); 1754 1755 if ((p = pfind(1)) == NULL) 1756 panic("[pmc,%d] Cannot find init", __LINE__); 1757 1758 PROC_UNLOCK(p); 1759 1760 sx_slock(&proctree_lock); 1761 1762 top = p; 1763 1764 for (;;) { 1765 pmc_log_process_mappings(po, p); 1766 if (!LIST_EMPTY(&p->p_children)) 1767 p = LIST_FIRST(&p->p_children); 1768 else for (;;) { 1769 if (p == top) 1770 goto done; 1771 if (LIST_NEXT(p, p_sibling)) { 1772 p = LIST_NEXT(p, p_sibling); 1773 break; 1774 } 1775 p = p->p_pptr; 1776 } 1777 } 1778 done: 1779 sx_sunlock(&proctree_lock); 1780 } 1781 1782 /* 1783 * The 'hook' invoked from the kernel proper 1784 */ 1785 1786 1787 #ifdef DEBUG 1788 const char *pmc_hooknames[] = { 1789 /* these strings correspond to PMC_FN_* in <sys/pmckern.h> */ 1790 "", 1791 "EXEC", 1792 "CSW-IN", 1793 "CSW-OUT", 1794 "SAMPLE", 1795 "UNUSED1", 1796 "UNUSED2", 1797 "MMAP", 1798 "MUNMAP", 1799 "CALLCHAIN-NMI", 1800 "CALLCHAIN-SOFT", 1801 "SOFTSAMPLING" 1802 }; 1803 #endif 1804 1805 static int 1806 pmc_hook_handler(struct thread *td, int function, void *arg) 1807 { 1808 1809 PMCDBG(MOD,PMH,1, "hook td=%p func=%d \"%s\" arg=%p", td, function, 1810 pmc_hooknames[function], arg); 1811 1812 switch (function) 1813 { 1814 1815 /* 1816 * Process exec() 1817 */ 1818 1819 case PMC_FN_PROCESS_EXEC: 1820 { 1821 char *fullpath, *freepath; 1822 unsigned int ri; 1823 int is_using_hwpmcs; 1824 struct pmc *pm; 1825 struct proc *p; 1826 struct pmc_owner *po; 1827 struct pmc_process *pp; 1828 struct pmckern_procexec *pk; 1829 1830 sx_assert(&pmc_sx, SX_XLOCKED); 1831 1832 p = td->td_proc; 1833 pmc_getfilename(p->p_textvp, &fullpath, &freepath); 1834 1835 pk = (struct pmckern_procexec *) arg; 1836 1837 /* Inform owners of SS mode PMCs of the exec event. */ 1838 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1839 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1840 pmclog_process_procexec(po, PMC_ID_INVALID, 1841 p->p_pid, pk->pm_entryaddr, fullpath); 1842 1843 PROC_LOCK(p); 1844 is_using_hwpmcs = p->p_flag & P_HWPMC; 1845 PROC_UNLOCK(p); 1846 1847 if (!is_using_hwpmcs) { 1848 if (freepath) 1849 free(freepath, M_TEMP); 1850 break; 1851 } 1852 1853 /* 1854 * PMCs are not inherited across an exec(): remove any 1855 * PMCs that this process is the owner of. 1856 */ 1857 1858 if ((po = pmc_find_owner_descriptor(p)) != NULL) { 1859 pmc_remove_owner(po); 1860 pmc_destroy_owner_descriptor(po); 1861 } 1862 1863 /* 1864 * If the process being exec'ed is not the target of any 1865 * PMC, we are done. 1866 */ 1867 if ((pp = pmc_find_process_descriptor(p, 0)) == NULL) { 1868 if (freepath) 1869 free(freepath, M_TEMP); 1870 break; 1871 } 1872 1873 /* 1874 * Log the exec event to all monitoring owners. Skip 1875 * owners who have already recieved the event because 1876 * they had system sampling PMCs active. 1877 */ 1878 for (ri = 0; ri < md->pmd_npmc; ri++) 1879 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) { 1880 po = pm->pm_owner; 1881 if (po->po_sscount == 0 && 1882 po->po_flags & PMC_PO_OWNS_LOGFILE) 1883 pmclog_process_procexec(po, pm->pm_id, 1884 p->p_pid, pk->pm_entryaddr, 1885 fullpath); 1886 } 1887 1888 if (freepath) 1889 free(freepath, M_TEMP); 1890 1891 1892 PMCDBG(PRC,EXC,1, "exec proc=%p (%d, %s) cred-changed=%d", 1893 p, p->p_pid, p->p_comm, pk->pm_credentialschanged); 1894 1895 if (pk->pm_credentialschanged == 0) /* no change */ 1896 break; 1897 1898 /* 1899 * If the newly exec()'ed process has a different credential 1900 * than before, allow it to be the target of a PMC only if 1901 * the PMC's owner has sufficient priviledge. 1902 */ 1903 1904 for (ri = 0; ri < md->pmd_npmc; ri++) 1905 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) 1906 if (pmc_can_attach(pm, td->td_proc) != 0) 1907 pmc_detach_one_process(td->td_proc, 1908 pm, PMC_FLAG_NONE); 1909 1910 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= (int) md->pmd_npmc, 1911 ("[pmc,%d] Illegal ref count %d on pp %p", __LINE__, 1912 pp->pp_refcnt, pp)); 1913 1914 /* 1915 * If this process is no longer the target of any 1916 * PMCs, we can remove the process entry and free 1917 * up space. 1918 */ 1919 1920 if (pp->pp_refcnt == 0) { 1921 pmc_remove_process_descriptor(pp); 1922 free(pp, M_PMC); 1923 break; 1924 } 1925 1926 } 1927 break; 1928 1929 case PMC_FN_CSW_IN: 1930 pmc_process_csw_in(td); 1931 break; 1932 1933 case PMC_FN_CSW_OUT: 1934 pmc_process_csw_out(td); 1935 break; 1936 1937 /* 1938 * Process accumulated PC samples. 1939 * 1940 * This function is expected to be called by hardclock() for 1941 * each CPU that has accumulated PC samples. 1942 * 1943 * This function is to be executed on the CPU whose samples 1944 * are being processed. 1945 */ 1946 case PMC_FN_DO_SAMPLES: 1947 1948 /* 1949 * Clear the cpu specific bit in the CPU mask before 1950 * do the rest of the processing. If the NMI handler 1951 * gets invoked after the "atomic_clear_int()" call 1952 * below but before "pmc_process_samples()" gets 1953 * around to processing the interrupt, then we will 1954 * come back here at the next hardclock() tick (and 1955 * may find nothing to do if "pmc_process_samples()" 1956 * had already processed the interrupt). We don't 1957 * lose the interrupt sample. 1958 */ 1959 CPU_CLR_ATOMIC(PCPU_GET(cpuid), &pmc_cpumask); 1960 pmc_process_samples(PCPU_GET(cpuid), PMC_HR); 1961 pmc_process_samples(PCPU_GET(cpuid), PMC_SR); 1962 break; 1963 1964 case PMC_FN_MMAP: 1965 sx_assert(&pmc_sx, SX_LOCKED); 1966 pmc_process_mmap(td, (struct pmckern_map_in *) arg); 1967 break; 1968 1969 case PMC_FN_MUNMAP: 1970 sx_assert(&pmc_sx, SX_LOCKED); 1971 pmc_process_munmap(td, (struct pmckern_map_out *) arg); 1972 break; 1973 1974 case PMC_FN_USER_CALLCHAIN: 1975 /* 1976 * Record a call chain. 1977 */ 1978 KASSERT(td == curthread, ("[pmc,%d] td != curthread", 1979 __LINE__)); 1980 1981 pmc_capture_user_callchain(PCPU_GET(cpuid), PMC_HR, 1982 (struct trapframe *) arg); 1983 td->td_pflags &= ~TDP_CALLCHAIN; 1984 break; 1985 1986 case PMC_FN_USER_CALLCHAIN_SOFT: 1987 /* 1988 * Record a call chain. 1989 */ 1990 KASSERT(td == curthread, ("[pmc,%d] td != curthread", 1991 __LINE__)); 1992 pmc_capture_user_callchain(PCPU_GET(cpuid), PMC_SR, 1993 (struct trapframe *) arg); 1994 td->td_pflags &= ~TDP_CALLCHAIN; 1995 break; 1996 1997 case PMC_FN_SOFT_SAMPLING: 1998 /* 1999 * Call soft PMC sampling intr. 2000 */ 2001 pmc_soft_intr((struct pmckern_soft *) arg); 2002 break; 2003 2004 default: 2005 #ifdef DEBUG 2006 KASSERT(0, ("[pmc,%d] unknown hook %d\n", __LINE__, function)); 2007 #endif 2008 break; 2009 2010 } 2011 2012 return 0; 2013 } 2014 2015 /* 2016 * allocate a 'struct pmc_owner' descriptor in the owner hash table. 2017 */ 2018 2019 static struct pmc_owner * 2020 pmc_allocate_owner_descriptor(struct proc *p) 2021 { 2022 uint32_t hindex; 2023 struct pmc_owner *po; 2024 struct pmc_ownerhash *poh; 2025 2026 hindex = PMC_HASH_PTR(p, pmc_ownerhashmask); 2027 poh = &pmc_ownerhash[hindex]; 2028 2029 /* allocate space for N pointers and one descriptor struct */ 2030 po = malloc(sizeof(struct pmc_owner), M_PMC, M_WAITOK|M_ZERO); 2031 po->po_owner = p; 2032 LIST_INSERT_HEAD(poh, po, po_next); /* insert into hash table */ 2033 2034 TAILQ_INIT(&po->po_logbuffers); 2035 mtx_init(&po->po_mtx, "pmc-owner-mtx", "pmc-per-proc", MTX_SPIN); 2036 2037 PMCDBG(OWN,ALL,1, "allocate-owner proc=%p (%d, %s) pmc-owner=%p", 2038 p, p->p_pid, p->p_comm, po); 2039 2040 return po; 2041 } 2042 2043 static void 2044 pmc_destroy_owner_descriptor(struct pmc_owner *po) 2045 { 2046 2047 PMCDBG(OWN,REL,1, "destroy-owner po=%p proc=%p (%d, %s)", 2048 po, po->po_owner, po->po_owner->p_pid, po->po_owner->p_comm); 2049 2050 mtx_destroy(&po->po_mtx); 2051 free(po, M_PMC); 2052 } 2053 2054 /* 2055 * find the descriptor corresponding to process 'p', adding or removing it 2056 * as specified by 'mode'. 2057 */ 2058 2059 static struct pmc_process * 2060 pmc_find_process_descriptor(struct proc *p, uint32_t mode) 2061 { 2062 uint32_t hindex; 2063 struct pmc_process *pp, *ppnew; 2064 struct pmc_processhash *pph; 2065 2066 hindex = PMC_HASH_PTR(p, pmc_processhashmask); 2067 pph = &pmc_processhash[hindex]; 2068 2069 ppnew = NULL; 2070 2071 /* 2072 * Pre-allocate memory in the FIND_ALLOCATE case since we 2073 * cannot call malloc(9) once we hold a spin lock. 2074 */ 2075 if (mode & PMC_FLAG_ALLOCATE) 2076 ppnew = malloc(sizeof(struct pmc_process) + md->pmd_npmc * 2077 sizeof(struct pmc_targetstate), M_PMC, M_WAITOK|M_ZERO); 2078 2079 mtx_lock_spin(&pmc_processhash_mtx); 2080 LIST_FOREACH(pp, pph, pp_next) 2081 if (pp->pp_proc == p) 2082 break; 2083 2084 if ((mode & PMC_FLAG_REMOVE) && pp != NULL) 2085 LIST_REMOVE(pp, pp_next); 2086 2087 if ((mode & PMC_FLAG_ALLOCATE) && pp == NULL && 2088 ppnew != NULL) { 2089 ppnew->pp_proc = p; 2090 LIST_INSERT_HEAD(pph, ppnew, pp_next); 2091 pp = ppnew; 2092 ppnew = NULL; 2093 } 2094 mtx_unlock_spin(&pmc_processhash_mtx); 2095 2096 if (pp != NULL && ppnew != NULL) 2097 free(ppnew, M_PMC); 2098 2099 return pp; 2100 } 2101 2102 /* 2103 * remove a process descriptor from the process hash table. 2104 */ 2105 2106 static void 2107 pmc_remove_process_descriptor(struct pmc_process *pp) 2108 { 2109 KASSERT(pp->pp_refcnt == 0, 2110 ("[pmc,%d] Removing process descriptor %p with count %d", 2111 __LINE__, pp, pp->pp_refcnt)); 2112 2113 mtx_lock_spin(&pmc_processhash_mtx); 2114 LIST_REMOVE(pp, pp_next); 2115 mtx_unlock_spin(&pmc_processhash_mtx); 2116 } 2117 2118 2119 /* 2120 * find an owner descriptor corresponding to proc 'p' 2121 */ 2122 2123 static struct pmc_owner * 2124 pmc_find_owner_descriptor(struct proc *p) 2125 { 2126 uint32_t hindex; 2127 struct pmc_owner *po; 2128 struct pmc_ownerhash *poh; 2129 2130 hindex = PMC_HASH_PTR(p, pmc_ownerhashmask); 2131 poh = &pmc_ownerhash[hindex]; 2132 2133 po = NULL; 2134 LIST_FOREACH(po, poh, po_next) 2135 if (po->po_owner == p) 2136 break; 2137 2138 PMCDBG(OWN,FND,1, "find-owner proc=%p (%d, %s) hindex=0x%x -> " 2139 "pmc-owner=%p", p, p->p_pid, p->p_comm, hindex, po); 2140 2141 return po; 2142 } 2143 2144 /* 2145 * pmc_allocate_pmc_descriptor 2146 * 2147 * Allocate a pmc descriptor and initialize its 2148 * fields. 2149 */ 2150 2151 static struct pmc * 2152 pmc_allocate_pmc_descriptor(void) 2153 { 2154 struct pmc *pmc; 2155 2156 pmc = malloc(sizeof(struct pmc), M_PMC, M_WAITOK|M_ZERO); 2157 2158 PMCDBG(PMC,ALL,1, "allocate-pmc -> pmc=%p", pmc); 2159 2160 return pmc; 2161 } 2162 2163 /* 2164 * Destroy a pmc descriptor. 2165 */ 2166 2167 static void 2168 pmc_destroy_pmc_descriptor(struct pmc *pm) 2169 { 2170 2171 KASSERT(pm->pm_state == PMC_STATE_DELETED || 2172 pm->pm_state == PMC_STATE_FREE, 2173 ("[pmc,%d] destroying non-deleted PMC", __LINE__)); 2174 KASSERT(LIST_EMPTY(&pm->pm_targets), 2175 ("[pmc,%d] destroying pmc with targets", __LINE__)); 2176 KASSERT(pm->pm_owner == NULL, 2177 ("[pmc,%d] destroying pmc attached to an owner", __LINE__)); 2178 KASSERT(pm->pm_runcount == 0, 2179 ("[pmc,%d] pmc has non-zero run count %d", __LINE__, 2180 pm->pm_runcount)); 2181 2182 free(pm, M_PMC); 2183 } 2184 2185 static void 2186 pmc_wait_for_pmc_idle(struct pmc *pm) 2187 { 2188 #ifdef DEBUG 2189 volatile int maxloop; 2190 2191 maxloop = 100 * pmc_cpu_max(); 2192 #endif 2193 /* 2194 * Loop (with a forced context switch) till the PMC's runcount 2195 * comes down to zero. 2196 */ 2197 while (atomic_load_acq_32(&pm->pm_runcount) > 0) { 2198 #ifdef DEBUG 2199 maxloop--; 2200 KASSERT(maxloop > 0, 2201 ("[pmc,%d] (ri%d, rc%d) waiting too long for " 2202 "pmc to be free", __LINE__, 2203 PMC_TO_ROWINDEX(pm), pm->pm_runcount)); 2204 #endif 2205 pmc_force_context_switch(); 2206 } 2207 } 2208 2209 /* 2210 * This function does the following things: 2211 * 2212 * - detaches the PMC from hardware 2213 * - unlinks all target threads that were attached to it 2214 * - removes the PMC from its owner's list 2215 * - destroys the PMC private mutex 2216 * 2217 * Once this function completes, the given pmc pointer can be freed by 2218 * calling pmc_destroy_pmc_descriptor(). 2219 */ 2220 2221 static void 2222 pmc_release_pmc_descriptor(struct pmc *pm) 2223 { 2224 enum pmc_mode mode; 2225 struct pmc_hw *phw; 2226 u_int adjri, ri, cpu; 2227 struct pmc_owner *po; 2228 struct pmc_binding pb; 2229 struct pmc_process *pp; 2230 struct pmc_classdep *pcd; 2231 struct pmc_target *ptgt, *tmp; 2232 2233 sx_assert(&pmc_sx, SX_XLOCKED); 2234 2235 KASSERT(pm, ("[pmc,%d] null pmc", __LINE__)); 2236 2237 ri = PMC_TO_ROWINDEX(pm); 2238 pcd = pmc_ri_to_classdep(md, ri, &adjri); 2239 mode = PMC_TO_MODE(pm); 2240 2241 PMCDBG(PMC,REL,1, "release-pmc pmc=%p ri=%d mode=%d", pm, ri, 2242 mode); 2243 2244 /* 2245 * First, we take the PMC off hardware. 2246 */ 2247 cpu = 0; 2248 if (PMC_IS_SYSTEM_MODE(mode)) { 2249 2250 /* 2251 * A system mode PMC runs on a specific CPU. Switch 2252 * to this CPU and turn hardware off. 2253 */ 2254 pmc_save_cpu_binding(&pb); 2255 2256 cpu = PMC_TO_CPU(pm); 2257 2258 pmc_select_cpu(cpu); 2259 2260 /* switch off non-stalled CPUs */ 2261 if (pm->pm_state == PMC_STATE_RUNNING && 2262 pm->pm_stalled == 0) { 2263 2264 phw = pmc_pcpu[cpu]->pc_hwpmcs[ri]; 2265 2266 KASSERT(phw->phw_pmc == pm, 2267 ("[pmc, %d] pmc ptr ri(%d) hw(%p) pm(%p)", 2268 __LINE__, ri, phw->phw_pmc, pm)); 2269 PMCDBG(PMC,REL,2, "stopping cpu=%d ri=%d", cpu, ri); 2270 2271 critical_enter(); 2272 pcd->pcd_stop_pmc(cpu, adjri); 2273 critical_exit(); 2274 } 2275 2276 PMCDBG(PMC,REL,2, "decfg cpu=%d ri=%d", cpu, ri); 2277 2278 critical_enter(); 2279 pcd->pcd_config_pmc(cpu, adjri, NULL); 2280 critical_exit(); 2281 2282 /* adjust the global and process count of SS mode PMCs */ 2283 if (mode == PMC_MODE_SS && pm->pm_state == PMC_STATE_RUNNING) { 2284 po = pm->pm_owner; 2285 po->po_sscount--; 2286 if (po->po_sscount == 0) { 2287 atomic_subtract_rel_int(&pmc_ss_count, 1); 2288 LIST_REMOVE(po, po_ssnext); 2289 } 2290 } 2291 2292 pm->pm_state = PMC_STATE_DELETED; 2293 2294 pmc_restore_cpu_binding(&pb); 2295 2296 /* 2297 * We could have references to this PMC structure in 2298 * the per-cpu sample queues. Wait for the queue to 2299 * drain. 2300 */ 2301 pmc_wait_for_pmc_idle(pm); 2302 2303 } else if (PMC_IS_VIRTUAL_MODE(mode)) { 2304 2305 /* 2306 * A virtual PMC could be running on multiple CPUs at 2307 * a given instant. 2308 * 2309 * By marking its state as DELETED, we ensure that 2310 * this PMC is never further scheduled on hardware. 2311 * 2312 * Then we wait till all CPUs are done with this PMC. 2313 */ 2314 pm->pm_state = PMC_STATE_DELETED; 2315 2316 2317 /* Wait for the PMCs runcount to come to zero. */ 2318 pmc_wait_for_pmc_idle(pm); 2319 2320 /* 2321 * At this point the PMC is off all CPUs and cannot be 2322 * freshly scheduled onto a CPU. It is now safe to 2323 * unlink all targets from this PMC. If a 2324 * process-record's refcount falls to zero, we remove 2325 * it from the hash table. The module-wide SX lock 2326 * protects us from races. 2327 */ 2328 LIST_FOREACH_SAFE(ptgt, &pm->pm_targets, pt_next, tmp) { 2329 pp = ptgt->pt_process; 2330 pmc_unlink_target_process(pm, pp); /* frees 'ptgt' */ 2331 2332 PMCDBG(PMC,REL,3, "pp->refcnt=%d", pp->pp_refcnt); 2333 2334 /* 2335 * If the target process record shows that no 2336 * PMCs are attached to it, reclaim its space. 2337 */ 2338 2339 if (pp->pp_refcnt == 0) { 2340 pmc_remove_process_descriptor(pp); 2341 free(pp, M_PMC); 2342 } 2343 } 2344 2345 cpu = curthread->td_oncpu; /* setup cpu for pmd_release() */ 2346 2347 } 2348 2349 /* 2350 * Release any MD resources 2351 */ 2352 (void) pcd->pcd_release_pmc(cpu, adjri, pm); 2353 2354 /* 2355 * Update row disposition 2356 */ 2357 2358 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) 2359 PMC_UNMARK_ROW_STANDALONE(ri); 2360 else 2361 PMC_UNMARK_ROW_THREAD(ri); 2362 2363 /* unlink from the owner's list */ 2364 if (pm->pm_owner) { 2365 LIST_REMOVE(pm, pm_next); 2366 pm->pm_owner = NULL; 2367 } 2368 } 2369 2370 /* 2371 * Register an owner and a pmc. 2372 */ 2373 2374 static int 2375 pmc_register_owner(struct proc *p, struct pmc *pmc) 2376 { 2377 struct pmc_owner *po; 2378 2379 sx_assert(&pmc_sx, SX_XLOCKED); 2380 2381 if ((po = pmc_find_owner_descriptor(p)) == NULL) 2382 if ((po = pmc_allocate_owner_descriptor(p)) == NULL) 2383 return ENOMEM; 2384 2385 KASSERT(pmc->pm_owner == NULL, 2386 ("[pmc,%d] attempting to own an initialized PMC", __LINE__)); 2387 pmc->pm_owner = po; 2388 2389 LIST_INSERT_HEAD(&po->po_pmcs, pmc, pm_next); 2390 2391 PROC_LOCK(p); 2392 p->p_flag |= P_HWPMC; 2393 PROC_UNLOCK(p); 2394 2395 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 2396 pmclog_process_pmcallocate(pmc); 2397 2398 PMCDBG(PMC,REG,1, "register-owner pmc-owner=%p pmc=%p", 2399 po, pmc); 2400 2401 return 0; 2402 } 2403 2404 /* 2405 * Return the current row disposition: 2406 * == 0 => FREE 2407 * > 0 => PROCESS MODE 2408 * < 0 => SYSTEM MODE 2409 */ 2410 2411 int 2412 pmc_getrowdisp(int ri) 2413 { 2414 return pmc_pmcdisp[ri]; 2415 } 2416 2417 /* 2418 * Check if a PMC at row index 'ri' can be allocated to the current 2419 * process. 2420 * 2421 * Allocation can fail if: 2422 * - the current process is already being profiled by a PMC at index 'ri', 2423 * attached to it via OP_PMCATTACH. 2424 * - the current process has already allocated a PMC at index 'ri' 2425 * via OP_ALLOCATE. 2426 */ 2427 2428 static int 2429 pmc_can_allocate_rowindex(struct proc *p, unsigned int ri, int cpu) 2430 { 2431 enum pmc_mode mode; 2432 struct pmc *pm; 2433 struct pmc_owner *po; 2434 struct pmc_process *pp; 2435 2436 PMCDBG(PMC,ALR,1, "can-allocate-rowindex proc=%p (%d, %s) ri=%d " 2437 "cpu=%d", p, p->p_pid, p->p_comm, ri, cpu); 2438 2439 /* 2440 * We shouldn't have already allocated a process-mode PMC at 2441 * row index 'ri'. 2442 * 2443 * We shouldn't have allocated a system-wide PMC on the same 2444 * CPU and same RI. 2445 */ 2446 if ((po = pmc_find_owner_descriptor(p)) != NULL) 2447 LIST_FOREACH(pm, &po->po_pmcs, pm_next) { 2448 if (PMC_TO_ROWINDEX(pm) == ri) { 2449 mode = PMC_TO_MODE(pm); 2450 if (PMC_IS_VIRTUAL_MODE(mode)) 2451 return EEXIST; 2452 if (PMC_IS_SYSTEM_MODE(mode) && 2453 (int) PMC_TO_CPU(pm) == cpu) 2454 return EEXIST; 2455 } 2456 } 2457 2458 /* 2459 * We also shouldn't be the target of any PMC at this index 2460 * since otherwise a PMC_ATTACH to ourselves will fail. 2461 */ 2462 if ((pp = pmc_find_process_descriptor(p, 0)) != NULL) 2463 if (pp->pp_pmcs[ri].pp_pmc) 2464 return EEXIST; 2465 2466 PMCDBG(PMC,ALR,2, "can-allocate-rowindex proc=%p (%d, %s) ri=%d ok", 2467 p, p->p_pid, p->p_comm, ri); 2468 2469 return 0; 2470 } 2471 2472 /* 2473 * Check if a given PMC at row index 'ri' can be currently used in 2474 * mode 'mode'. 2475 */ 2476 2477 static int 2478 pmc_can_allocate_row(int ri, enum pmc_mode mode) 2479 { 2480 enum pmc_disp disp; 2481 2482 sx_assert(&pmc_sx, SX_XLOCKED); 2483 2484 PMCDBG(PMC,ALR,1, "can-allocate-row ri=%d mode=%d", ri, mode); 2485 2486 if (PMC_IS_SYSTEM_MODE(mode)) 2487 disp = PMC_DISP_STANDALONE; 2488 else 2489 disp = PMC_DISP_THREAD; 2490 2491 /* 2492 * check disposition for PMC row 'ri': 2493 * 2494 * Expected disposition Row-disposition Result 2495 * 2496 * STANDALONE STANDALONE or FREE proceed 2497 * STANDALONE THREAD fail 2498 * THREAD THREAD or FREE proceed 2499 * THREAD STANDALONE fail 2500 */ 2501 2502 if (!PMC_ROW_DISP_IS_FREE(ri) && 2503 !(disp == PMC_DISP_THREAD && PMC_ROW_DISP_IS_THREAD(ri)) && 2504 !(disp == PMC_DISP_STANDALONE && PMC_ROW_DISP_IS_STANDALONE(ri))) 2505 return EBUSY; 2506 2507 /* 2508 * All OK 2509 */ 2510 2511 PMCDBG(PMC,ALR,2, "can-allocate-row ri=%d mode=%d ok", ri, mode); 2512 2513 return 0; 2514 2515 } 2516 2517 /* 2518 * Find a PMC descriptor with user handle 'pmcid' for thread 'td'. 2519 */ 2520 2521 static struct pmc * 2522 pmc_find_pmc_descriptor_in_process(struct pmc_owner *po, pmc_id_t pmcid) 2523 { 2524 struct pmc *pm; 2525 2526 KASSERT(PMC_ID_TO_ROWINDEX(pmcid) < md->pmd_npmc, 2527 ("[pmc,%d] Illegal pmc index %d (max %d)", __LINE__, 2528 PMC_ID_TO_ROWINDEX(pmcid), md->pmd_npmc)); 2529 2530 LIST_FOREACH(pm, &po->po_pmcs, pm_next) 2531 if (pm->pm_id == pmcid) 2532 return pm; 2533 2534 return NULL; 2535 } 2536 2537 static int 2538 pmc_find_pmc(pmc_id_t pmcid, struct pmc **pmc) 2539 { 2540 2541 struct pmc *pm; 2542 struct pmc_owner *po; 2543 2544 PMCDBG(PMC,FND,1, "find-pmc id=%d", pmcid); 2545 2546 if ((po = pmc_find_owner_descriptor(curthread->td_proc)) == NULL) 2547 return ESRCH; 2548 2549 if ((pm = pmc_find_pmc_descriptor_in_process(po, pmcid)) == NULL) 2550 return EINVAL; 2551 2552 PMCDBG(PMC,FND,2, "find-pmc id=%d -> pmc=%p", pmcid, pm); 2553 2554 *pmc = pm; 2555 return 0; 2556 } 2557 2558 /* 2559 * Start a PMC. 2560 */ 2561 2562 static int 2563 pmc_start(struct pmc *pm) 2564 { 2565 enum pmc_mode mode; 2566 struct pmc_owner *po; 2567 struct pmc_binding pb; 2568 struct pmc_classdep *pcd; 2569 int adjri, error, cpu, ri; 2570 2571 KASSERT(pm != NULL, 2572 ("[pmc,%d] null pm", __LINE__)); 2573 2574 mode = PMC_TO_MODE(pm); 2575 ri = PMC_TO_ROWINDEX(pm); 2576 pcd = pmc_ri_to_classdep(md, ri, &adjri); 2577 2578 error = 0; 2579 2580 PMCDBG(PMC,OPS,1, "start pmc=%p mode=%d ri=%d", pm, mode, ri); 2581 2582 po = pm->pm_owner; 2583 2584 /* 2585 * Disallow PMCSTART if a logfile is required but has not been 2586 * configured yet. 2587 */ 2588 if ((pm->pm_flags & PMC_F_NEEDS_LOGFILE) && 2589 (po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) 2590 return (EDOOFUS); /* programming error */ 2591 2592 /* 2593 * If this is a sampling mode PMC, log mapping information for 2594 * the kernel modules that are currently loaded. 2595 */ 2596 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 2597 pmc_log_kernel_mappings(pm); 2598 2599 if (PMC_IS_VIRTUAL_MODE(mode)) { 2600 2601 /* 2602 * If a PMCATTACH has never been done on this PMC, 2603 * attach it to its owner process. 2604 */ 2605 2606 if (LIST_EMPTY(&pm->pm_targets)) 2607 error = (pm->pm_flags & PMC_F_ATTACH_DONE) ? ESRCH : 2608 pmc_attach_process(po->po_owner, pm); 2609 2610 /* 2611 * If the PMC is attached to its owner, then force a context 2612 * switch to ensure that the MD state gets set correctly. 2613 */ 2614 2615 if (error == 0) { 2616 pm->pm_state = PMC_STATE_RUNNING; 2617 if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) 2618 pmc_force_context_switch(); 2619 } 2620 2621 return (error); 2622 } 2623 2624 2625 /* 2626 * A system-wide PMC. 2627 * 2628 * Add the owner to the global list if this is a system-wide 2629 * sampling PMC. 2630 */ 2631 2632 if (mode == PMC_MODE_SS) { 2633 if (po->po_sscount == 0) { 2634 LIST_INSERT_HEAD(&pmc_ss_owners, po, po_ssnext); 2635 atomic_add_rel_int(&pmc_ss_count, 1); 2636 PMCDBG(PMC,OPS,1, "po=%p in global list", po); 2637 } 2638 po->po_sscount++; 2639 2640 /* 2641 * Log mapping information for all existing processes in the 2642 * system. Subsequent mappings are logged as they happen; 2643 * see pmc_process_mmap(). 2644 */ 2645 if (po->po_logprocmaps == 0) { 2646 pmc_log_all_process_mappings(po); 2647 po->po_logprocmaps = 1; 2648 } 2649 } 2650 2651 /* 2652 * Move to the CPU associated with this 2653 * PMC, and start the hardware. 2654 */ 2655 2656 pmc_save_cpu_binding(&pb); 2657 2658 cpu = PMC_TO_CPU(pm); 2659 2660 if (!pmc_cpu_is_active(cpu)) 2661 return (ENXIO); 2662 2663 pmc_select_cpu(cpu); 2664 2665 /* 2666 * global PMCs are configured at allocation time 2667 * so write out the initial value and start the PMC. 2668 */ 2669 2670 pm->pm_state = PMC_STATE_RUNNING; 2671 2672 critical_enter(); 2673 if ((error = pcd->pcd_write_pmc(cpu, adjri, 2674 PMC_IS_SAMPLING_MODE(mode) ? 2675 pm->pm_sc.pm_reloadcount : 2676 pm->pm_sc.pm_initial)) == 0) 2677 error = pcd->pcd_start_pmc(cpu, adjri); 2678 critical_exit(); 2679 2680 pmc_restore_cpu_binding(&pb); 2681 2682 return (error); 2683 } 2684 2685 /* 2686 * Stop a PMC. 2687 */ 2688 2689 static int 2690 pmc_stop(struct pmc *pm) 2691 { 2692 struct pmc_owner *po; 2693 struct pmc_binding pb; 2694 struct pmc_classdep *pcd; 2695 int adjri, cpu, error, ri; 2696 2697 KASSERT(pm != NULL, ("[pmc,%d] null pmc", __LINE__)); 2698 2699 PMCDBG(PMC,OPS,1, "stop pmc=%p mode=%d ri=%d", pm, 2700 PMC_TO_MODE(pm), PMC_TO_ROWINDEX(pm)); 2701 2702 pm->pm_state = PMC_STATE_STOPPED; 2703 2704 /* 2705 * If the PMC is a virtual mode one, changing the state to 2706 * non-RUNNING is enough to ensure that the PMC never gets 2707 * scheduled. 2708 * 2709 * If this PMC is current running on a CPU, then it will 2710 * handled correctly at the time its target process is context 2711 * switched out. 2712 */ 2713 2714 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) 2715 return 0; 2716 2717 /* 2718 * A system-mode PMC. Move to the CPU associated with 2719 * this PMC, and stop the hardware. We update the 2720 * 'initial count' so that a subsequent PMCSTART will 2721 * resume counting from the current hardware count. 2722 */ 2723 2724 pmc_save_cpu_binding(&pb); 2725 2726 cpu = PMC_TO_CPU(pm); 2727 2728 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 2729 ("[pmc,%d] illegal cpu=%d", __LINE__, cpu)); 2730 2731 if (!pmc_cpu_is_active(cpu)) 2732 return ENXIO; 2733 2734 pmc_select_cpu(cpu); 2735 2736 ri = PMC_TO_ROWINDEX(pm); 2737 pcd = pmc_ri_to_classdep(md, ri, &adjri); 2738 2739 critical_enter(); 2740 if ((error = pcd->pcd_stop_pmc(cpu, adjri)) == 0) 2741 error = pcd->pcd_read_pmc(cpu, adjri, &pm->pm_sc.pm_initial); 2742 critical_exit(); 2743 2744 pmc_restore_cpu_binding(&pb); 2745 2746 po = pm->pm_owner; 2747 2748 /* remove this owner from the global list of SS PMC owners */ 2749 if (PMC_TO_MODE(pm) == PMC_MODE_SS) { 2750 po->po_sscount--; 2751 if (po->po_sscount == 0) { 2752 atomic_subtract_rel_int(&pmc_ss_count, 1); 2753 LIST_REMOVE(po, po_ssnext); 2754 PMCDBG(PMC,OPS,2,"po=%p removed from global list", po); 2755 } 2756 } 2757 2758 return (error); 2759 } 2760 2761 2762 #ifdef DEBUG 2763 static const char *pmc_op_to_name[] = { 2764 #undef __PMC_OP 2765 #define __PMC_OP(N, D) #N , 2766 __PMC_OPS() 2767 NULL 2768 }; 2769 #endif 2770 2771 /* 2772 * The syscall interface 2773 */ 2774 2775 #define PMC_GET_SX_XLOCK(...) do { \ 2776 sx_xlock(&pmc_sx); \ 2777 if (pmc_hook == NULL) { \ 2778 sx_xunlock(&pmc_sx); \ 2779 return __VA_ARGS__; \ 2780 } \ 2781 } while (0) 2782 2783 #define PMC_DOWNGRADE_SX() do { \ 2784 sx_downgrade(&pmc_sx); \ 2785 is_sx_downgraded = 1; \ 2786 } while (0) 2787 2788 static int 2789 pmc_syscall_handler(struct thread *td, void *syscall_args) 2790 { 2791 int error, is_sx_downgraded, is_sx_locked, op; 2792 struct pmc_syscall_args *c; 2793 void *arg; 2794 2795 PMC_GET_SX_XLOCK(ENOSYS); 2796 2797 DROP_GIANT(); 2798 2799 is_sx_downgraded = 0; 2800 is_sx_locked = 1; 2801 2802 c = (struct pmc_syscall_args *) syscall_args; 2803 2804 op = c->pmop_code; 2805 arg = c->pmop_data; 2806 2807 PMCDBG(MOD,PMS,1, "syscall op=%d \"%s\" arg=%p", op, 2808 pmc_op_to_name[op], arg); 2809 2810 error = 0; 2811 atomic_add_int(&pmc_stats.pm_syscalls, 1); 2812 2813 switch(op) 2814 { 2815 2816 2817 /* 2818 * Configure a log file. 2819 * 2820 * XXX This OP will be reworked. 2821 */ 2822 2823 case PMC_OP_CONFIGURELOG: 2824 { 2825 struct proc *p; 2826 struct pmc *pm; 2827 struct pmc_owner *po; 2828 struct pmc_op_configurelog cl; 2829 2830 sx_assert(&pmc_sx, SX_XLOCKED); 2831 2832 if ((error = copyin(arg, &cl, sizeof(cl))) != 0) 2833 break; 2834 2835 /* mark this process as owning a log file */ 2836 p = td->td_proc; 2837 if ((po = pmc_find_owner_descriptor(p)) == NULL) 2838 if ((po = pmc_allocate_owner_descriptor(p)) == NULL) { 2839 error = ENOMEM; 2840 break; 2841 } 2842 2843 /* 2844 * If a valid fd was passed in, try to configure that, 2845 * otherwise if 'fd' was less than zero and there was 2846 * a log file configured, flush its buffers and 2847 * de-configure it. 2848 */ 2849 if (cl.pm_logfd >= 0) { 2850 sx_xunlock(&pmc_sx); 2851 is_sx_locked = 0; 2852 error = pmclog_configure_log(md, po, cl.pm_logfd); 2853 } else if (po->po_flags & PMC_PO_OWNS_LOGFILE) { 2854 pmclog_process_closelog(po); 2855 error = pmclog_close(po); 2856 if (error == 0) { 2857 LIST_FOREACH(pm, &po->po_pmcs, pm_next) 2858 if (pm->pm_flags & PMC_F_NEEDS_LOGFILE && 2859 pm->pm_state == PMC_STATE_RUNNING) 2860 pmc_stop(pm); 2861 error = pmclog_deconfigure_log(po); 2862 } 2863 } else 2864 error = EINVAL; 2865 2866 if (error) 2867 break; 2868 } 2869 break; 2870 2871 /* 2872 * Flush a log file. 2873 */ 2874 2875 case PMC_OP_FLUSHLOG: 2876 { 2877 struct pmc_owner *po; 2878 2879 sx_assert(&pmc_sx, SX_XLOCKED); 2880 2881 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 2882 error = EINVAL; 2883 break; 2884 } 2885 2886 error = pmclog_flush(po); 2887 } 2888 break; 2889 2890 /* 2891 * Close a log file. 2892 */ 2893 2894 case PMC_OP_CLOSELOG: 2895 { 2896 struct pmc_owner *po; 2897 2898 sx_assert(&pmc_sx, SX_XLOCKED); 2899 2900 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 2901 error = EINVAL; 2902 break; 2903 } 2904 2905 error = pmclog_close(po); 2906 } 2907 break; 2908 2909 /* 2910 * Retrieve hardware configuration. 2911 */ 2912 2913 case PMC_OP_GETCPUINFO: /* CPU information */ 2914 { 2915 struct pmc_op_getcpuinfo gci; 2916 struct pmc_classinfo *pci; 2917 struct pmc_classdep *pcd; 2918 int cl; 2919 2920 gci.pm_cputype = md->pmd_cputype; 2921 gci.pm_ncpu = pmc_cpu_max(); 2922 gci.pm_npmc = md->pmd_npmc; 2923 gci.pm_nclass = md->pmd_nclass; 2924 pci = gci.pm_classes; 2925 pcd = md->pmd_classdep; 2926 for (cl = 0; cl < md->pmd_nclass; cl++, pci++, pcd++) { 2927 pci->pm_caps = pcd->pcd_caps; 2928 pci->pm_class = pcd->pcd_class; 2929 pci->pm_width = pcd->pcd_width; 2930 pci->pm_num = pcd->pcd_num; 2931 } 2932 error = copyout(&gci, arg, sizeof(gci)); 2933 } 2934 break; 2935 2936 /* 2937 * Retrieve soft events list. 2938 */ 2939 case PMC_OP_GETDYNEVENTINFO: 2940 { 2941 enum pmc_class cl; 2942 enum pmc_event ev; 2943 struct pmc_op_getdyneventinfo *gei; 2944 struct pmc_dyn_event_descr dev; 2945 struct pmc_soft *ps; 2946 uint32_t nevent; 2947 2948 sx_assert(&pmc_sx, SX_LOCKED); 2949 2950 gei = (struct pmc_op_getdyneventinfo *) arg; 2951 2952 if ((error = copyin(&gei->pm_class, &cl, sizeof(cl))) != 0) 2953 break; 2954 2955 /* Only SOFT class is dynamic. */ 2956 if (cl != PMC_CLASS_SOFT) { 2957 error = EINVAL; 2958 break; 2959 } 2960 2961 nevent = 0; 2962 for (ev = PMC_EV_SOFT_FIRST; (int)ev <= PMC_EV_SOFT_LAST; ev++) { 2963 ps = pmc_soft_ev_acquire(ev); 2964 if (ps == NULL) 2965 continue; 2966 bcopy(&ps->ps_ev, &dev, sizeof(dev)); 2967 pmc_soft_ev_release(ps); 2968 2969 error = copyout(&dev, 2970 &gei->pm_events[nevent], 2971 sizeof(struct pmc_dyn_event_descr)); 2972 if (error != 0) 2973 break; 2974 nevent++; 2975 } 2976 if (error != 0) 2977 break; 2978 2979 error = copyout(&nevent, &gei->pm_nevent, 2980 sizeof(nevent)); 2981 } 2982 break; 2983 2984 /* 2985 * Get module statistics 2986 */ 2987 2988 case PMC_OP_GETDRIVERSTATS: 2989 { 2990 struct pmc_op_getdriverstats gms; 2991 2992 bcopy(&pmc_stats, &gms, sizeof(gms)); 2993 error = copyout(&gms, arg, sizeof(gms)); 2994 } 2995 break; 2996 2997 2998 /* 2999 * Retrieve module version number 3000 */ 3001 3002 case PMC_OP_GETMODULEVERSION: 3003 { 3004 uint32_t cv, modv; 3005 3006 /* retrieve the client's idea of the ABI version */ 3007 if ((error = copyin(arg, &cv, sizeof(uint32_t))) != 0) 3008 break; 3009 /* don't service clients newer than our driver */ 3010 modv = PMC_VERSION; 3011 if ((cv & 0xFFFF0000) > (modv & 0xFFFF0000)) { 3012 error = EPROGMISMATCH; 3013 break; 3014 } 3015 error = copyout(&modv, arg, sizeof(int)); 3016 } 3017 break; 3018 3019 3020 /* 3021 * Retrieve the state of all the PMCs on a given 3022 * CPU. 3023 */ 3024 3025 case PMC_OP_GETPMCINFO: 3026 { 3027 int ari; 3028 struct pmc *pm; 3029 size_t pmcinfo_size; 3030 uint32_t cpu, n, npmc; 3031 struct pmc_owner *po; 3032 struct pmc_binding pb; 3033 struct pmc_classdep *pcd; 3034 struct pmc_info *p, *pmcinfo; 3035 struct pmc_op_getpmcinfo *gpi; 3036 3037 PMC_DOWNGRADE_SX(); 3038 3039 gpi = (struct pmc_op_getpmcinfo *) arg; 3040 3041 if ((error = copyin(&gpi->pm_cpu, &cpu, sizeof(cpu))) != 0) 3042 break; 3043 3044 if (cpu >= pmc_cpu_max()) { 3045 error = EINVAL; 3046 break; 3047 } 3048 3049 if (!pmc_cpu_is_active(cpu)) { 3050 error = ENXIO; 3051 break; 3052 } 3053 3054 /* switch to CPU 'cpu' */ 3055 pmc_save_cpu_binding(&pb); 3056 pmc_select_cpu(cpu); 3057 3058 npmc = md->pmd_npmc; 3059 3060 pmcinfo_size = npmc * sizeof(struct pmc_info); 3061 pmcinfo = malloc(pmcinfo_size, M_PMC, M_WAITOK); 3062 3063 p = pmcinfo; 3064 3065 for (n = 0; n < md->pmd_npmc; n++, p++) { 3066 3067 pcd = pmc_ri_to_classdep(md, n, &ari); 3068 3069 KASSERT(pcd != NULL, 3070 ("[pmc,%d] null pcd ri=%d", __LINE__, n)); 3071 3072 if ((error = pcd->pcd_describe(cpu, ari, p, &pm)) != 0) 3073 break; 3074 3075 if (PMC_ROW_DISP_IS_STANDALONE(n)) 3076 p->pm_rowdisp = PMC_DISP_STANDALONE; 3077 else if (PMC_ROW_DISP_IS_THREAD(n)) 3078 p->pm_rowdisp = PMC_DISP_THREAD; 3079 else 3080 p->pm_rowdisp = PMC_DISP_FREE; 3081 3082 p->pm_ownerpid = -1; 3083 3084 if (pm == NULL) /* no PMC associated */ 3085 continue; 3086 3087 po = pm->pm_owner; 3088 3089 KASSERT(po->po_owner != NULL, 3090 ("[pmc,%d] pmc_owner had a null proc pointer", 3091 __LINE__)); 3092 3093 p->pm_ownerpid = po->po_owner->p_pid; 3094 p->pm_mode = PMC_TO_MODE(pm); 3095 p->pm_event = pm->pm_event; 3096 p->pm_flags = pm->pm_flags; 3097 3098 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 3099 p->pm_reloadcount = 3100 pm->pm_sc.pm_reloadcount; 3101 } 3102 3103 pmc_restore_cpu_binding(&pb); 3104 3105 /* now copy out the PMC info collected */ 3106 if (error == 0) 3107 error = copyout(pmcinfo, &gpi->pm_pmcs, pmcinfo_size); 3108 3109 free(pmcinfo, M_PMC); 3110 } 3111 break; 3112 3113 3114 /* 3115 * Set the administrative state of a PMC. I.e. whether 3116 * the PMC is to be used or not. 3117 */ 3118 3119 case PMC_OP_PMCADMIN: 3120 { 3121 int cpu, ri; 3122 enum pmc_state request; 3123 struct pmc_cpu *pc; 3124 struct pmc_hw *phw; 3125 struct pmc_op_pmcadmin pma; 3126 struct pmc_binding pb; 3127 3128 sx_assert(&pmc_sx, SX_XLOCKED); 3129 3130 KASSERT(td == curthread, 3131 ("[pmc,%d] td != curthread", __LINE__)); 3132 3133 error = priv_check(td, PRIV_PMC_MANAGE); 3134 if (error) 3135 break; 3136 3137 if ((error = copyin(arg, &pma, sizeof(pma))) != 0) 3138 break; 3139 3140 cpu = pma.pm_cpu; 3141 3142 if (cpu < 0 || cpu >= (int) pmc_cpu_max()) { 3143 error = EINVAL; 3144 break; 3145 } 3146 3147 if (!pmc_cpu_is_active(cpu)) { 3148 error = ENXIO; 3149 break; 3150 } 3151 3152 request = pma.pm_state; 3153 3154 if (request != PMC_STATE_DISABLED && 3155 request != PMC_STATE_FREE) { 3156 error = EINVAL; 3157 break; 3158 } 3159 3160 ri = pma.pm_pmc; /* pmc id == row index */ 3161 if (ri < 0 || ri >= (int) md->pmd_npmc) { 3162 error = EINVAL; 3163 break; 3164 } 3165 3166 /* 3167 * We can't disable a PMC with a row-index allocated 3168 * for process virtual PMCs. 3169 */ 3170 3171 if (PMC_ROW_DISP_IS_THREAD(ri) && 3172 request == PMC_STATE_DISABLED) { 3173 error = EBUSY; 3174 break; 3175 } 3176 3177 /* 3178 * otherwise, this PMC on this CPU is either free or 3179 * in system-wide mode. 3180 */ 3181 3182 pmc_save_cpu_binding(&pb); 3183 pmc_select_cpu(cpu); 3184 3185 pc = pmc_pcpu[cpu]; 3186 phw = pc->pc_hwpmcs[ri]; 3187 3188 /* 3189 * XXX do we need some kind of 'forced' disable? 3190 */ 3191 3192 if (phw->phw_pmc == NULL) { 3193 if (request == PMC_STATE_DISABLED && 3194 (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED)) { 3195 phw->phw_state &= ~PMC_PHW_FLAG_IS_ENABLED; 3196 PMC_MARK_ROW_STANDALONE(ri); 3197 } else if (request == PMC_STATE_FREE && 3198 (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0) { 3199 phw->phw_state |= PMC_PHW_FLAG_IS_ENABLED; 3200 PMC_UNMARK_ROW_STANDALONE(ri); 3201 } 3202 /* other cases are a no-op */ 3203 } else 3204 error = EBUSY; 3205 3206 pmc_restore_cpu_binding(&pb); 3207 } 3208 break; 3209 3210 3211 /* 3212 * Allocate a PMC. 3213 */ 3214 3215 case PMC_OP_PMCALLOCATE: 3216 { 3217 int adjri, n; 3218 u_int cpu; 3219 uint32_t caps; 3220 struct pmc *pmc; 3221 enum pmc_mode mode; 3222 struct pmc_hw *phw; 3223 struct pmc_binding pb; 3224 struct pmc_classdep *pcd; 3225 struct pmc_op_pmcallocate pa; 3226 3227 if ((error = copyin(arg, &pa, sizeof(pa))) != 0) 3228 break; 3229 3230 caps = pa.pm_caps; 3231 mode = pa.pm_mode; 3232 cpu = pa.pm_cpu; 3233 3234 if ((mode != PMC_MODE_SS && mode != PMC_MODE_SC && 3235 mode != PMC_MODE_TS && mode != PMC_MODE_TC) || 3236 (cpu != (u_int) PMC_CPU_ANY && cpu >= pmc_cpu_max())) { 3237 error = EINVAL; 3238 break; 3239 } 3240 3241 /* 3242 * Virtual PMCs should only ask for a default CPU. 3243 * System mode PMCs need to specify a non-default CPU. 3244 */ 3245 3246 if ((PMC_IS_VIRTUAL_MODE(mode) && cpu != (u_int) PMC_CPU_ANY) || 3247 (PMC_IS_SYSTEM_MODE(mode) && cpu == (u_int) PMC_CPU_ANY)) { 3248 error = EINVAL; 3249 break; 3250 } 3251 3252 /* 3253 * Check that an inactive CPU is not being asked for. 3254 */ 3255 3256 if (PMC_IS_SYSTEM_MODE(mode) && !pmc_cpu_is_active(cpu)) { 3257 error = ENXIO; 3258 break; 3259 } 3260 3261 /* 3262 * Refuse an allocation for a system-wide PMC if this 3263 * process has been jailed, or if this process lacks 3264 * super-user credentials and the sysctl tunable 3265 * 'security.bsd.unprivileged_syspmcs' is zero. 3266 */ 3267 3268 if (PMC_IS_SYSTEM_MODE(mode)) { 3269 if (jailed(curthread->td_ucred)) { 3270 error = EPERM; 3271 break; 3272 } 3273 if (!pmc_unprivileged_syspmcs) { 3274 error = priv_check(curthread, 3275 PRIV_PMC_SYSTEM); 3276 if (error) 3277 break; 3278 } 3279 } 3280 3281 /* 3282 * Look for valid values for 'pm_flags' 3283 */ 3284 3285 if ((pa.pm_flags & ~(PMC_F_DESCENDANTS | PMC_F_LOG_PROCCSW | 3286 PMC_F_LOG_PROCEXIT | PMC_F_CALLCHAIN)) != 0) { 3287 error = EINVAL; 3288 break; 3289 } 3290 3291 /* process logging options are not allowed for system PMCs */ 3292 if (PMC_IS_SYSTEM_MODE(mode) && (pa.pm_flags & 3293 (PMC_F_LOG_PROCCSW | PMC_F_LOG_PROCEXIT))) { 3294 error = EINVAL; 3295 break; 3296 } 3297 3298 /* 3299 * All sampling mode PMCs need to be able to interrupt the 3300 * CPU. 3301 */ 3302 if (PMC_IS_SAMPLING_MODE(mode)) 3303 caps |= PMC_CAP_INTERRUPT; 3304 3305 /* A valid class specifier should have been passed in. */ 3306 for (n = 0; n < md->pmd_nclass; n++) 3307 if (md->pmd_classdep[n].pcd_class == pa.pm_class) 3308 break; 3309 if (n == md->pmd_nclass) { 3310 error = EINVAL; 3311 break; 3312 } 3313 3314 /* The requested PMC capabilities should be feasible. */ 3315 if ((md->pmd_classdep[n].pcd_caps & caps) != caps) { 3316 error = EOPNOTSUPP; 3317 break; 3318 } 3319 3320 PMCDBG(PMC,ALL,2, "event=%d caps=0x%x mode=%d cpu=%d", 3321 pa.pm_ev, caps, mode, cpu); 3322 3323 pmc = pmc_allocate_pmc_descriptor(); 3324 pmc->pm_id = PMC_ID_MAKE_ID(cpu,pa.pm_mode,pa.pm_class, 3325 PMC_ID_INVALID); 3326 pmc->pm_event = pa.pm_ev; 3327 pmc->pm_state = PMC_STATE_FREE; 3328 pmc->pm_caps = caps; 3329 pmc->pm_flags = pa.pm_flags; 3330 3331 /* switch thread to CPU 'cpu' */ 3332 pmc_save_cpu_binding(&pb); 3333 3334 #define PMC_IS_SHAREABLE_PMC(cpu, n) \ 3335 (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_state & \ 3336 PMC_PHW_FLAG_IS_SHAREABLE) 3337 #define PMC_IS_UNALLOCATED(cpu, n) \ 3338 (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_pmc == NULL) 3339 3340 if (PMC_IS_SYSTEM_MODE(mode)) { 3341 pmc_select_cpu(cpu); 3342 for (n = 0; n < (int) md->pmd_npmc; n++) { 3343 pcd = pmc_ri_to_classdep(md, n, &adjri); 3344 if (pmc_can_allocate_row(n, mode) == 0 && 3345 pmc_can_allocate_rowindex( 3346 curthread->td_proc, n, cpu) == 0 && 3347 (PMC_IS_UNALLOCATED(cpu, n) || 3348 PMC_IS_SHAREABLE_PMC(cpu, n)) && 3349 pcd->pcd_allocate_pmc(cpu, adjri, pmc, 3350 &pa) == 0) 3351 break; 3352 } 3353 } else { 3354 /* Process virtual mode */ 3355 for (n = 0; n < (int) md->pmd_npmc; n++) { 3356 pcd = pmc_ri_to_classdep(md, n, &adjri); 3357 if (pmc_can_allocate_row(n, mode) == 0 && 3358 pmc_can_allocate_rowindex( 3359 curthread->td_proc, n, 3360 PMC_CPU_ANY) == 0 && 3361 pcd->pcd_allocate_pmc(curthread->td_oncpu, 3362 adjri, pmc, &pa) == 0) 3363 break; 3364 } 3365 } 3366 3367 #undef PMC_IS_UNALLOCATED 3368 #undef PMC_IS_SHAREABLE_PMC 3369 3370 pmc_restore_cpu_binding(&pb); 3371 3372 if (n == (int) md->pmd_npmc) { 3373 pmc_destroy_pmc_descriptor(pmc); 3374 pmc = NULL; 3375 error = EINVAL; 3376 break; 3377 } 3378 3379 /* Fill in the correct value in the ID field */ 3380 pmc->pm_id = PMC_ID_MAKE_ID(cpu,mode,pa.pm_class,n); 3381 3382 PMCDBG(PMC,ALL,2, "ev=%d class=%d mode=%d n=%d -> pmcid=%x", 3383 pmc->pm_event, pa.pm_class, mode, n, pmc->pm_id); 3384 3385 /* Process mode PMCs with logging enabled need log files */ 3386 if (pmc->pm_flags & (PMC_F_LOG_PROCEXIT | PMC_F_LOG_PROCCSW)) 3387 pmc->pm_flags |= PMC_F_NEEDS_LOGFILE; 3388 3389 /* All system mode sampling PMCs require a log file */ 3390 if (PMC_IS_SAMPLING_MODE(mode) && PMC_IS_SYSTEM_MODE(mode)) 3391 pmc->pm_flags |= PMC_F_NEEDS_LOGFILE; 3392 3393 /* 3394 * Configure global pmc's immediately 3395 */ 3396 3397 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pmc))) { 3398 3399 pmc_save_cpu_binding(&pb); 3400 pmc_select_cpu(cpu); 3401 3402 phw = pmc_pcpu[cpu]->pc_hwpmcs[n]; 3403 pcd = pmc_ri_to_classdep(md, n, &adjri); 3404 3405 if ((phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0 || 3406 (error = pcd->pcd_config_pmc(cpu, adjri, pmc)) != 0) { 3407 (void) pcd->pcd_release_pmc(cpu, adjri, pmc); 3408 pmc_destroy_pmc_descriptor(pmc); 3409 pmc = NULL; 3410 pmc_restore_cpu_binding(&pb); 3411 error = EPERM; 3412 break; 3413 } 3414 3415 pmc_restore_cpu_binding(&pb); 3416 } 3417 3418 pmc->pm_state = PMC_STATE_ALLOCATED; 3419 3420 /* 3421 * mark row disposition 3422 */ 3423 3424 if (PMC_IS_SYSTEM_MODE(mode)) 3425 PMC_MARK_ROW_STANDALONE(n); 3426 else 3427 PMC_MARK_ROW_THREAD(n); 3428 3429 /* 3430 * Register this PMC with the current thread as its owner. 3431 */ 3432 3433 if ((error = 3434 pmc_register_owner(curthread->td_proc, pmc)) != 0) { 3435 pmc_release_pmc_descriptor(pmc); 3436 pmc_destroy_pmc_descriptor(pmc); 3437 pmc = NULL; 3438 break; 3439 } 3440 3441 /* 3442 * Return the allocated index. 3443 */ 3444 3445 pa.pm_pmcid = pmc->pm_id; 3446 3447 error = copyout(&pa, arg, sizeof(pa)); 3448 } 3449 break; 3450 3451 3452 /* 3453 * Attach a PMC to a process. 3454 */ 3455 3456 case PMC_OP_PMCATTACH: 3457 { 3458 struct pmc *pm; 3459 struct proc *p; 3460 struct pmc_op_pmcattach a; 3461 3462 sx_assert(&pmc_sx, SX_XLOCKED); 3463 3464 if ((error = copyin(arg, &a, sizeof(a))) != 0) 3465 break; 3466 3467 if (a.pm_pid < 0) { 3468 error = EINVAL; 3469 break; 3470 } else if (a.pm_pid == 0) 3471 a.pm_pid = td->td_proc->p_pid; 3472 3473 if ((error = pmc_find_pmc(a.pm_pmc, &pm)) != 0) 3474 break; 3475 3476 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) { 3477 error = EINVAL; 3478 break; 3479 } 3480 3481 /* PMCs may be (re)attached only when allocated or stopped */ 3482 if (pm->pm_state == PMC_STATE_RUNNING) { 3483 error = EBUSY; 3484 break; 3485 } else if (pm->pm_state != PMC_STATE_ALLOCATED && 3486 pm->pm_state != PMC_STATE_STOPPED) { 3487 error = EINVAL; 3488 break; 3489 } 3490 3491 /* lookup pid */ 3492 if ((p = pfind(a.pm_pid)) == NULL) { 3493 error = ESRCH; 3494 break; 3495 } 3496 3497 /* 3498 * Ignore processes that are working on exiting. 3499 */ 3500 if (p->p_flag & P_WEXIT) { 3501 error = ESRCH; 3502 PROC_UNLOCK(p); /* pfind() returns a locked process */ 3503 break; 3504 } 3505 3506 /* 3507 * we are allowed to attach a PMC to a process if 3508 * we can debug it. 3509 */ 3510 error = p_candebug(curthread, p); 3511 3512 PROC_UNLOCK(p); 3513 3514 if (error == 0) 3515 error = pmc_attach_process(p, pm); 3516 } 3517 break; 3518 3519 3520 /* 3521 * Detach an attached PMC from a process. 3522 */ 3523 3524 case PMC_OP_PMCDETACH: 3525 { 3526 struct pmc *pm; 3527 struct proc *p; 3528 struct pmc_op_pmcattach a; 3529 3530 if ((error = copyin(arg, &a, sizeof(a))) != 0) 3531 break; 3532 3533 if (a.pm_pid < 0) { 3534 error = EINVAL; 3535 break; 3536 } else if (a.pm_pid == 0) 3537 a.pm_pid = td->td_proc->p_pid; 3538 3539 if ((error = pmc_find_pmc(a.pm_pmc, &pm)) != 0) 3540 break; 3541 3542 if ((p = pfind(a.pm_pid)) == NULL) { 3543 error = ESRCH; 3544 break; 3545 } 3546 3547 /* 3548 * Treat processes that are in the process of exiting 3549 * as if they were not present. 3550 */ 3551 3552 if (p->p_flag & P_WEXIT) 3553 error = ESRCH; 3554 3555 PROC_UNLOCK(p); /* pfind() returns a locked process */ 3556 3557 if (error == 0) 3558 error = pmc_detach_process(p, pm); 3559 } 3560 break; 3561 3562 3563 /* 3564 * Retrieve the MSR number associated with the counter 3565 * 'pmc_id'. This allows processes to directly use RDPMC 3566 * instructions to read their PMCs, without the overhead of a 3567 * system call. 3568 */ 3569 3570 case PMC_OP_PMCGETMSR: 3571 { 3572 int adjri, ri; 3573 struct pmc *pm; 3574 struct pmc_target *pt; 3575 struct pmc_op_getmsr gm; 3576 struct pmc_classdep *pcd; 3577 3578 PMC_DOWNGRADE_SX(); 3579 3580 if ((error = copyin(arg, &gm, sizeof(gm))) != 0) 3581 break; 3582 3583 if ((error = pmc_find_pmc(gm.pm_pmcid, &pm)) != 0) 3584 break; 3585 3586 /* 3587 * The allocated PMC has to be a process virtual PMC, 3588 * i.e., of type MODE_T[CS]. Global PMCs can only be 3589 * read using the PMCREAD operation since they may be 3590 * allocated on a different CPU than the one we could 3591 * be running on at the time of the RDPMC instruction. 3592 * 3593 * The GETMSR operation is not allowed for PMCs that 3594 * are inherited across processes. 3595 */ 3596 3597 if (!PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)) || 3598 (pm->pm_flags & PMC_F_DESCENDANTS)) { 3599 error = EINVAL; 3600 break; 3601 } 3602 3603 /* 3604 * It only makes sense to use a RDPMC (or its 3605 * equivalent instruction on non-x86 architectures) on 3606 * a process that has allocated and attached a PMC to 3607 * itself. Conversely the PMC is only allowed to have 3608 * one process attached to it -- its owner. 3609 */ 3610 3611 if ((pt = LIST_FIRST(&pm->pm_targets)) == NULL || 3612 LIST_NEXT(pt, pt_next) != NULL || 3613 pt->pt_process->pp_proc != pm->pm_owner->po_owner) { 3614 error = EINVAL; 3615 break; 3616 } 3617 3618 ri = PMC_TO_ROWINDEX(pm); 3619 pcd = pmc_ri_to_classdep(md, ri, &adjri); 3620 3621 /* PMC class has no 'GETMSR' support */ 3622 if (pcd->pcd_get_msr == NULL) { 3623 error = ENOSYS; 3624 break; 3625 } 3626 3627 if ((error = (*pcd->pcd_get_msr)(adjri, &gm.pm_msr)) < 0) 3628 break; 3629 3630 if ((error = copyout(&gm, arg, sizeof(gm))) < 0) 3631 break; 3632 3633 /* 3634 * Mark our process as using MSRs. Update machine 3635 * state using a forced context switch. 3636 */ 3637 3638 pt->pt_process->pp_flags |= PMC_PP_ENABLE_MSR_ACCESS; 3639 pmc_force_context_switch(); 3640 3641 } 3642 break; 3643 3644 /* 3645 * Release an allocated PMC 3646 */ 3647 3648 case PMC_OP_PMCRELEASE: 3649 { 3650 pmc_id_t pmcid; 3651 struct pmc *pm; 3652 struct pmc_owner *po; 3653 struct pmc_op_simple sp; 3654 3655 /* 3656 * Find PMC pointer for the named PMC. 3657 * 3658 * Use pmc_release_pmc_descriptor() to switch off the 3659 * PMC, remove all its target threads, and remove the 3660 * PMC from its owner's list. 3661 * 3662 * Remove the owner record if this is the last PMC 3663 * owned. 3664 * 3665 * Free up space. 3666 */ 3667 3668 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 3669 break; 3670 3671 pmcid = sp.pm_pmcid; 3672 3673 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 3674 break; 3675 3676 po = pm->pm_owner; 3677 pmc_release_pmc_descriptor(pm); 3678 pmc_maybe_remove_owner(po); 3679 pmc_destroy_pmc_descriptor(pm); 3680 } 3681 break; 3682 3683 3684 /* 3685 * Read and/or write a PMC. 3686 */ 3687 3688 case PMC_OP_PMCRW: 3689 { 3690 int adjri; 3691 struct pmc *pm; 3692 uint32_t cpu, ri; 3693 pmc_value_t oldvalue; 3694 struct pmc_binding pb; 3695 struct pmc_op_pmcrw prw; 3696 struct pmc_classdep *pcd; 3697 struct pmc_op_pmcrw *pprw; 3698 3699 PMC_DOWNGRADE_SX(); 3700 3701 if ((error = copyin(arg, &prw, sizeof(prw))) != 0) 3702 break; 3703 3704 ri = 0; 3705 PMCDBG(PMC,OPS,1, "rw id=%d flags=0x%x", prw.pm_pmcid, 3706 prw.pm_flags); 3707 3708 /* must have at least one flag set */ 3709 if ((prw.pm_flags & (PMC_F_OLDVALUE|PMC_F_NEWVALUE)) == 0) { 3710 error = EINVAL; 3711 break; 3712 } 3713 3714 /* locate pmc descriptor */ 3715 if ((error = pmc_find_pmc(prw.pm_pmcid, &pm)) != 0) 3716 break; 3717 3718 /* Can't read a PMC that hasn't been started. */ 3719 if (pm->pm_state != PMC_STATE_ALLOCATED && 3720 pm->pm_state != PMC_STATE_STOPPED && 3721 pm->pm_state != PMC_STATE_RUNNING) { 3722 error = EINVAL; 3723 break; 3724 } 3725 3726 /* writing a new value is allowed only for 'STOPPED' pmcs */ 3727 if (pm->pm_state == PMC_STATE_RUNNING && 3728 (prw.pm_flags & PMC_F_NEWVALUE)) { 3729 error = EBUSY; 3730 break; 3731 } 3732 3733 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) { 3734 3735 /* 3736 * If this PMC is attached to its owner (i.e., 3737 * the process requesting this operation) and 3738 * is running, then attempt to get an 3739 * upto-date reading from hardware for a READ. 3740 * Writes are only allowed when the PMC is 3741 * stopped, so only update the saved value 3742 * field. 3743 * 3744 * If the PMC is not running, or is not 3745 * attached to its owner, read/write to the 3746 * savedvalue field. 3747 */ 3748 3749 ri = PMC_TO_ROWINDEX(pm); 3750 pcd = pmc_ri_to_classdep(md, ri, &adjri); 3751 3752 mtx_pool_lock_spin(pmc_mtxpool, pm); 3753 cpu = curthread->td_oncpu; 3754 3755 if (prw.pm_flags & PMC_F_OLDVALUE) { 3756 if ((pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) && 3757 (pm->pm_state == PMC_STATE_RUNNING)) 3758 error = (*pcd->pcd_read_pmc)(cpu, adjri, 3759 &oldvalue); 3760 else 3761 oldvalue = pm->pm_gv.pm_savedvalue; 3762 } 3763 if (prw.pm_flags & PMC_F_NEWVALUE) 3764 pm->pm_gv.pm_savedvalue = prw.pm_value; 3765 3766 mtx_pool_unlock_spin(pmc_mtxpool, pm); 3767 3768 } else { /* System mode PMCs */ 3769 cpu = PMC_TO_CPU(pm); 3770 ri = PMC_TO_ROWINDEX(pm); 3771 pcd = pmc_ri_to_classdep(md, ri, &adjri); 3772 3773 if (!pmc_cpu_is_active(cpu)) { 3774 error = ENXIO; 3775 break; 3776 } 3777 3778 /* move this thread to CPU 'cpu' */ 3779 pmc_save_cpu_binding(&pb); 3780 pmc_select_cpu(cpu); 3781 3782 critical_enter(); 3783 /* save old value */ 3784 if (prw.pm_flags & PMC_F_OLDVALUE) 3785 if ((error = (*pcd->pcd_read_pmc)(cpu, adjri, 3786 &oldvalue))) 3787 goto error; 3788 /* write out new value */ 3789 if (prw.pm_flags & PMC_F_NEWVALUE) 3790 error = (*pcd->pcd_write_pmc)(cpu, adjri, 3791 prw.pm_value); 3792 error: 3793 critical_exit(); 3794 pmc_restore_cpu_binding(&pb); 3795 if (error) 3796 break; 3797 } 3798 3799 pprw = (struct pmc_op_pmcrw *) arg; 3800 3801 #ifdef DEBUG 3802 if (prw.pm_flags & PMC_F_NEWVALUE) 3803 PMCDBG(PMC,OPS,2, "rw id=%d new %jx -> old %jx", 3804 ri, prw.pm_value, oldvalue); 3805 else if (prw.pm_flags & PMC_F_OLDVALUE) 3806 PMCDBG(PMC,OPS,2, "rw id=%d -> old %jx", ri, oldvalue); 3807 #endif 3808 3809 /* return old value if requested */ 3810 if (prw.pm_flags & PMC_F_OLDVALUE) 3811 if ((error = copyout(&oldvalue, &pprw->pm_value, 3812 sizeof(prw.pm_value)))) 3813 break; 3814 3815 } 3816 break; 3817 3818 3819 /* 3820 * Set the sampling rate for a sampling mode PMC and the 3821 * initial count for a counting mode PMC. 3822 */ 3823 3824 case PMC_OP_PMCSETCOUNT: 3825 { 3826 struct pmc *pm; 3827 struct pmc_op_pmcsetcount sc; 3828 3829 PMC_DOWNGRADE_SX(); 3830 3831 if ((error = copyin(arg, &sc, sizeof(sc))) != 0) 3832 break; 3833 3834 if ((error = pmc_find_pmc(sc.pm_pmcid, &pm)) != 0) 3835 break; 3836 3837 if (pm->pm_state == PMC_STATE_RUNNING) { 3838 error = EBUSY; 3839 break; 3840 } 3841 3842 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 3843 pm->pm_sc.pm_reloadcount = sc.pm_count; 3844 else 3845 pm->pm_sc.pm_initial = sc.pm_count; 3846 } 3847 break; 3848 3849 3850 /* 3851 * Start a PMC. 3852 */ 3853 3854 case PMC_OP_PMCSTART: 3855 { 3856 pmc_id_t pmcid; 3857 struct pmc *pm; 3858 struct pmc_op_simple sp; 3859 3860 sx_assert(&pmc_sx, SX_XLOCKED); 3861 3862 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 3863 break; 3864 3865 pmcid = sp.pm_pmcid; 3866 3867 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 3868 break; 3869 3870 KASSERT(pmcid == pm->pm_id, 3871 ("[pmc,%d] pmcid %x != id %x", __LINE__, 3872 pm->pm_id, pmcid)); 3873 3874 if (pm->pm_state == PMC_STATE_RUNNING) /* already running */ 3875 break; 3876 else if (pm->pm_state != PMC_STATE_STOPPED && 3877 pm->pm_state != PMC_STATE_ALLOCATED) { 3878 error = EINVAL; 3879 break; 3880 } 3881 3882 error = pmc_start(pm); 3883 } 3884 break; 3885 3886 3887 /* 3888 * Stop a PMC. 3889 */ 3890 3891 case PMC_OP_PMCSTOP: 3892 { 3893 pmc_id_t pmcid; 3894 struct pmc *pm; 3895 struct pmc_op_simple sp; 3896 3897 PMC_DOWNGRADE_SX(); 3898 3899 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 3900 break; 3901 3902 pmcid = sp.pm_pmcid; 3903 3904 /* 3905 * Mark the PMC as inactive and invoke the MD stop 3906 * routines if needed. 3907 */ 3908 3909 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 3910 break; 3911 3912 KASSERT(pmcid == pm->pm_id, 3913 ("[pmc,%d] pmc id %x != pmcid %x", __LINE__, 3914 pm->pm_id, pmcid)); 3915 3916 if (pm->pm_state == PMC_STATE_STOPPED) /* already stopped */ 3917 break; 3918 else if (pm->pm_state != PMC_STATE_RUNNING) { 3919 error = EINVAL; 3920 break; 3921 } 3922 3923 error = pmc_stop(pm); 3924 } 3925 break; 3926 3927 3928 /* 3929 * Write a user supplied value to the log file. 3930 */ 3931 3932 case PMC_OP_WRITELOG: 3933 { 3934 struct pmc_op_writelog wl; 3935 struct pmc_owner *po; 3936 3937 PMC_DOWNGRADE_SX(); 3938 3939 if ((error = copyin(arg, &wl, sizeof(wl))) != 0) 3940 break; 3941 3942 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 3943 error = EINVAL; 3944 break; 3945 } 3946 3947 if ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) { 3948 error = EINVAL; 3949 break; 3950 } 3951 3952 error = pmclog_process_userlog(po, &wl); 3953 } 3954 break; 3955 3956 3957 default: 3958 error = EINVAL; 3959 break; 3960 } 3961 3962 if (is_sx_locked != 0) { 3963 if (is_sx_downgraded) 3964 sx_sunlock(&pmc_sx); 3965 else 3966 sx_xunlock(&pmc_sx); 3967 } 3968 3969 if (error) 3970 atomic_add_int(&pmc_stats.pm_syscall_errors, 1); 3971 3972 PICKUP_GIANT(); 3973 3974 return error; 3975 } 3976 3977 /* 3978 * Helper functions 3979 */ 3980 3981 3982 /* 3983 * Mark the thread as needing callchain capture and post an AST. The 3984 * actual callchain capture will be done in a context where it is safe 3985 * to take page faults. 3986 */ 3987 3988 static void 3989 pmc_post_callchain_callback(void) 3990 { 3991 struct thread *td; 3992 3993 td = curthread; 3994 3995 /* 3996 * If there is multiple PMCs for the same interrupt ignore new post 3997 */ 3998 if (td->td_pflags & TDP_CALLCHAIN) 3999 return; 4000 4001 /* 4002 * Mark this thread as needing callchain capture. 4003 * `td->td_pflags' will be safe to touch because this thread 4004 * was in user space when it was interrupted. 4005 */ 4006 td->td_pflags |= TDP_CALLCHAIN; 4007 4008 /* 4009 * Don't let this thread migrate between CPUs until callchain 4010 * capture completes. 4011 */ 4012 sched_pin(); 4013 4014 return; 4015 } 4016 4017 /* 4018 * Interrupt processing. 4019 * 4020 * Find a free slot in the per-cpu array of samples and capture the 4021 * current callchain there. If a sample was successfully added, a bit 4022 * is set in mask 'pmc_cpumask' denoting that the DO_SAMPLES hook 4023 * needs to be invoked from the clock handler. 4024 * 4025 * This function is meant to be called from an NMI handler. It cannot 4026 * use any of the locking primitives supplied by the OS. 4027 */ 4028 4029 int 4030 pmc_process_interrupt(int cpu, int ring, struct pmc *pm, struct trapframe *tf, 4031 int inuserspace) 4032 { 4033 int error, callchaindepth; 4034 struct thread *td; 4035 struct pmc_sample *ps; 4036 struct pmc_samplebuffer *psb; 4037 4038 error = 0; 4039 4040 /* 4041 * Allocate space for a sample buffer. 4042 */ 4043 psb = pmc_pcpu[cpu]->pc_sb[ring]; 4044 4045 ps = psb->ps_write; 4046 if (ps->ps_nsamples) { /* in use, reader hasn't caught up */ 4047 pm->pm_stalled = 1; 4048 atomic_add_int(&pmc_stats.pm_intr_bufferfull, 1); 4049 PMCDBG(SAM,INT,1,"(spc) cpu=%d pm=%p tf=%p um=%d wr=%d rd=%d", 4050 cpu, pm, (void *) tf, inuserspace, 4051 (int) (psb->ps_write - psb->ps_samples), 4052 (int) (psb->ps_read - psb->ps_samples)); 4053 error = ENOMEM; 4054 goto done; 4055 } 4056 4057 4058 /* Fill in entry. */ 4059 PMCDBG(SAM,INT,1,"cpu=%d pm=%p tf=%p um=%d wr=%d rd=%d", cpu, pm, 4060 (void *) tf, inuserspace, 4061 (int) (psb->ps_write - psb->ps_samples), 4062 (int) (psb->ps_read - psb->ps_samples)); 4063 4064 KASSERT(pm->pm_runcount >= 0, 4065 ("[pmc,%d] pm=%p runcount %d", __LINE__, (void *) pm, 4066 pm->pm_runcount)); 4067 4068 atomic_add_rel_int(&pm->pm_runcount, 1); /* hold onto PMC */ 4069 4070 ps->ps_pmc = pm; 4071 if ((td = curthread) && td->td_proc) 4072 ps->ps_pid = td->td_proc->p_pid; 4073 else 4074 ps->ps_pid = -1; 4075 ps->ps_cpu = cpu; 4076 ps->ps_td = td; 4077 ps->ps_flags = inuserspace ? PMC_CC_F_USERSPACE : 0; 4078 4079 callchaindepth = (pm->pm_flags & PMC_F_CALLCHAIN) ? 4080 pmc_callchaindepth : 1; 4081 4082 if (callchaindepth == 1) 4083 ps->ps_pc[0] = PMC_TRAPFRAME_TO_PC(tf); 4084 else { 4085 /* 4086 * Kernel stack traversals can be done immediately, 4087 * while we defer to an AST for user space traversals. 4088 */ 4089 if (!inuserspace) { 4090 callchaindepth = 4091 pmc_save_kernel_callchain(ps->ps_pc, 4092 callchaindepth, tf); 4093 } else { 4094 pmc_post_callchain_callback(); 4095 callchaindepth = PMC_SAMPLE_INUSE; 4096 } 4097 } 4098 4099 ps->ps_nsamples = callchaindepth; /* mark entry as in use */ 4100 4101 /* increment write pointer, modulo ring buffer size */ 4102 ps++; 4103 if (ps == psb->ps_fence) 4104 psb->ps_write = psb->ps_samples; 4105 else 4106 psb->ps_write = ps; 4107 4108 done: 4109 /* mark CPU as needing processing */ 4110 CPU_SET_ATOMIC(cpu, &pmc_cpumask); 4111 4112 return (error); 4113 } 4114 4115 /* 4116 * Capture a user call chain. This function will be called from ast() 4117 * before control returns to userland and before the process gets 4118 * rescheduled. 4119 */ 4120 4121 static void 4122 pmc_capture_user_callchain(int cpu, int ring, struct trapframe *tf) 4123 { 4124 int i; 4125 struct pmc *pm; 4126 struct thread *td; 4127 struct pmc_sample *ps; 4128 struct pmc_samplebuffer *psb; 4129 #ifdef INVARIANTS 4130 int ncallchains; 4131 #endif 4132 4133 psb = pmc_pcpu[cpu]->pc_sb[ring]; 4134 td = curthread; 4135 4136 KASSERT(td->td_pflags & TDP_CALLCHAIN, 4137 ("[pmc,%d] Retrieving callchain for thread that doesn't want it", 4138 __LINE__)); 4139 4140 #ifdef INVARIANTS 4141 ncallchains = 0; 4142 #endif 4143 4144 /* 4145 * Iterate through all deferred callchain requests. 4146 */ 4147 4148 ps = psb->ps_samples; 4149 for (i = 0; i < pmc_nsamples; i++, ps++) { 4150 4151 if (ps->ps_nsamples != PMC_SAMPLE_INUSE) 4152 continue; 4153 if (ps->ps_td != td) 4154 continue; 4155 4156 KASSERT(ps->ps_cpu == cpu, 4157 ("[pmc,%d] cpu mismatch ps_cpu=%d pcpu=%d", __LINE__, 4158 ps->ps_cpu, PCPU_GET(cpuid))); 4159 4160 pm = ps->ps_pmc; 4161 4162 KASSERT(pm->pm_flags & PMC_F_CALLCHAIN, 4163 ("[pmc,%d] Retrieving callchain for PMC that doesn't " 4164 "want it", __LINE__)); 4165 4166 KASSERT(pm->pm_runcount > 0, 4167 ("[pmc,%d] runcount %d", __LINE__, pm->pm_runcount)); 4168 4169 /* 4170 * Retrieve the callchain and mark the sample buffer 4171 * as 'processable' by the timer tick sweep code. 4172 */ 4173 ps->ps_nsamples = pmc_save_user_callchain(ps->ps_pc, 4174 pmc_callchaindepth, tf); 4175 4176 #ifdef INVARIANTS 4177 ncallchains++; 4178 #endif 4179 } 4180 4181 KASSERT(ncallchains > 0, 4182 ("[pmc,%d] cpu %d didn't find a sample to collect", __LINE__, 4183 cpu)); 4184 4185 KASSERT(td->td_pinned == 1, 4186 ("[pmc,%d] invalid td_pinned value", __LINE__)); 4187 sched_unpin(); /* Can migrate safely now. */ 4188 4189 return; 4190 } 4191 4192 /* 4193 * Process saved PC samples. 4194 */ 4195 4196 static void 4197 pmc_process_samples(int cpu, int ring) 4198 { 4199 struct pmc *pm; 4200 int adjri, n; 4201 struct thread *td; 4202 struct pmc_owner *po; 4203 struct pmc_sample *ps; 4204 struct pmc_classdep *pcd; 4205 struct pmc_samplebuffer *psb; 4206 4207 KASSERT(PCPU_GET(cpuid) == cpu, 4208 ("[pmc,%d] not on the correct CPU pcpu=%d cpu=%d", __LINE__, 4209 PCPU_GET(cpuid), cpu)); 4210 4211 psb = pmc_pcpu[cpu]->pc_sb[ring]; 4212 4213 for (n = 0; n < pmc_nsamples; n++) { /* bound on #iterations */ 4214 4215 ps = psb->ps_read; 4216 if (ps->ps_nsamples == PMC_SAMPLE_FREE) 4217 break; 4218 4219 pm = ps->ps_pmc; 4220 4221 KASSERT(pm->pm_runcount > 0, 4222 ("[pmc,%d] pm=%p runcount %d", __LINE__, (void *) pm, 4223 pm->pm_runcount)); 4224 4225 po = pm->pm_owner; 4226 4227 KASSERT(PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)), 4228 ("[pmc,%d] pmc=%p non-sampling mode=%d", __LINE__, 4229 pm, PMC_TO_MODE(pm))); 4230 4231 /* Ignore PMCs that have been switched off */ 4232 if (pm->pm_state != PMC_STATE_RUNNING) 4233 goto entrydone; 4234 4235 /* If there is a pending AST wait for completion */ 4236 if (ps->ps_nsamples == PMC_SAMPLE_INUSE) { 4237 /* Need a rescan at a later time. */ 4238 CPU_SET_ATOMIC(cpu, &pmc_cpumask); 4239 break; 4240 } 4241 4242 PMCDBG(SAM,OPS,1,"cpu=%d pm=%p n=%d fl=%x wr=%d rd=%d", cpu, 4243 pm, ps->ps_nsamples, ps->ps_flags, 4244 (int) (psb->ps_write - psb->ps_samples), 4245 (int) (psb->ps_read - psb->ps_samples)); 4246 4247 /* 4248 * If this is a process-mode PMC that is attached to 4249 * its owner, and if the PC is in user mode, update 4250 * profiling statistics like timer-based profiling 4251 * would have done. 4252 */ 4253 if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) { 4254 if (ps->ps_flags & PMC_CC_F_USERSPACE) { 4255 td = FIRST_THREAD_IN_PROC(po->po_owner); 4256 addupc_intr(td, ps->ps_pc[0], 1); 4257 } 4258 goto entrydone; 4259 } 4260 4261 /* 4262 * Otherwise, this is either a sampling mode PMC that 4263 * is attached to a different process than its owner, 4264 * or a system-wide sampling PMC. Dispatch a log 4265 * entry to the PMC's owner process. 4266 */ 4267 pmclog_process_callchain(pm, ps); 4268 4269 entrydone: 4270 ps->ps_nsamples = 0; /* mark entry as free */ 4271 atomic_subtract_rel_int(&pm->pm_runcount, 1); 4272 4273 /* increment read pointer, modulo sample size */ 4274 if (++ps == psb->ps_fence) 4275 psb->ps_read = psb->ps_samples; 4276 else 4277 psb->ps_read = ps; 4278 } 4279 4280 atomic_add_int(&pmc_stats.pm_log_sweeps, 1); 4281 4282 /* Do not re-enable stalled PMCs if we failed to process any samples */ 4283 if (n == 0) 4284 return; 4285 4286 /* 4287 * Restart any stalled sampling PMCs on this CPU. 4288 * 4289 * If the NMI handler sets the pm_stalled field of a PMC after 4290 * the check below, we'll end up processing the stalled PMC at 4291 * the next hardclock tick. 4292 */ 4293 for (n = 0; n < md->pmd_npmc; n++) { 4294 pcd = pmc_ri_to_classdep(md, n, &adjri); 4295 KASSERT(pcd != NULL, 4296 ("[pmc,%d] null pcd ri=%d", __LINE__, n)); 4297 (void) (*pcd->pcd_get_config)(cpu,adjri,&pm); 4298 4299 if (pm == NULL || /* !cfg'ed */ 4300 pm->pm_state != PMC_STATE_RUNNING || /* !active */ 4301 !PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)) || /* !sampling */ 4302 pm->pm_stalled == 0) /* !stalled */ 4303 continue; 4304 4305 pm->pm_stalled = 0; 4306 (*pcd->pcd_start_pmc)(cpu, adjri); 4307 } 4308 } 4309 4310 /* 4311 * Event handlers. 4312 */ 4313 4314 /* 4315 * Handle a process exit. 4316 * 4317 * Remove this process from all hash tables. If this process 4318 * owned any PMCs, turn off those PMCs and deallocate them, 4319 * removing any associations with target processes. 4320 * 4321 * This function will be called by the last 'thread' of a 4322 * process. 4323 * 4324 * XXX This eventhandler gets called early in the exit process. 4325 * Consider using a 'hook' invocation from thread_exit() or equivalent 4326 * spot. Another negative is that kse_exit doesn't seem to call 4327 * exit1() [??]. 4328 * 4329 */ 4330 4331 static void 4332 pmc_process_exit(void *arg __unused, struct proc *p) 4333 { 4334 struct pmc *pm; 4335 int adjri, cpu; 4336 unsigned int ri; 4337 int is_using_hwpmcs; 4338 struct pmc_owner *po; 4339 struct pmc_process *pp; 4340 struct pmc_classdep *pcd; 4341 pmc_value_t newvalue, tmp; 4342 4343 PROC_LOCK(p); 4344 is_using_hwpmcs = p->p_flag & P_HWPMC; 4345 PROC_UNLOCK(p); 4346 4347 /* 4348 * Log a sysexit event to all SS PMC owners. 4349 */ 4350 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 4351 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 4352 pmclog_process_sysexit(po, p->p_pid); 4353 4354 if (!is_using_hwpmcs) 4355 return; 4356 4357 PMC_GET_SX_XLOCK(); 4358 PMCDBG(PRC,EXT,1,"process-exit proc=%p (%d, %s)", p, p->p_pid, 4359 p->p_comm); 4360 4361 /* 4362 * Since this code is invoked by the last thread in an exiting 4363 * process, we would have context switched IN at some prior 4364 * point. However, with PREEMPTION, kernel mode context 4365 * switches may happen any time, so we want to disable a 4366 * context switch OUT till we get any PMCs targetting this 4367 * process off the hardware. 4368 * 4369 * We also need to atomically remove this process' 4370 * entry from our target process hash table, using 4371 * PMC_FLAG_REMOVE. 4372 */ 4373 PMCDBG(PRC,EXT,1, "process-exit proc=%p (%d, %s)", p, p->p_pid, 4374 p->p_comm); 4375 4376 critical_enter(); /* no preemption */ 4377 4378 cpu = curthread->td_oncpu; 4379 4380 if ((pp = pmc_find_process_descriptor(p, 4381 PMC_FLAG_REMOVE)) != NULL) { 4382 4383 PMCDBG(PRC,EXT,2, 4384 "process-exit proc=%p pmc-process=%p", p, pp); 4385 4386 /* 4387 * The exiting process could the target of 4388 * some PMCs which will be running on 4389 * currently executing CPU. 4390 * 4391 * We need to turn these PMCs off like we 4392 * would do at context switch OUT time. 4393 */ 4394 for (ri = 0; ri < md->pmd_npmc; ri++) { 4395 4396 /* 4397 * Pick up the pmc pointer from hardware 4398 * state similar to the CSW_OUT code. 4399 */ 4400 pm = NULL; 4401 4402 pcd = pmc_ri_to_classdep(md, ri, &adjri); 4403 4404 (void) (*pcd->pcd_get_config)(cpu, adjri, &pm); 4405 4406 PMCDBG(PRC,EXT,2, "ri=%d pm=%p", ri, pm); 4407 4408 if (pm == NULL || 4409 !PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) 4410 continue; 4411 4412 PMCDBG(PRC,EXT,2, "ppmcs[%d]=%p pm=%p " 4413 "state=%d", ri, pp->pp_pmcs[ri].pp_pmc, 4414 pm, pm->pm_state); 4415 4416 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 4417 ("[pmc,%d] ri mismatch pmc(%d) ri(%d)", 4418 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 4419 4420 KASSERT(pm == pp->pp_pmcs[ri].pp_pmc, 4421 ("[pmc,%d] pm %p != pp_pmcs[%d] %p", 4422 __LINE__, pm, ri, pp->pp_pmcs[ri].pp_pmc)); 4423 4424 (void) pcd->pcd_stop_pmc(cpu, adjri); 4425 4426 KASSERT(pm->pm_runcount > 0, 4427 ("[pmc,%d] bad runcount ri %d rc %d", 4428 __LINE__, ri, pm->pm_runcount)); 4429 4430 /* Stop hardware only if it is actually running */ 4431 if (pm->pm_state == PMC_STATE_RUNNING && 4432 pm->pm_stalled == 0) { 4433 pcd->pcd_read_pmc(cpu, adjri, &newvalue); 4434 tmp = newvalue - 4435 PMC_PCPU_SAVED(cpu,ri); 4436 4437 mtx_pool_lock_spin(pmc_mtxpool, pm); 4438 pm->pm_gv.pm_savedvalue += tmp; 4439 pp->pp_pmcs[ri].pp_pmcval += tmp; 4440 mtx_pool_unlock_spin(pmc_mtxpool, pm); 4441 } 4442 4443 atomic_subtract_rel_int(&pm->pm_runcount,1); 4444 4445 KASSERT((int) pm->pm_runcount >= 0, 4446 ("[pmc,%d] runcount is %d", __LINE__, ri)); 4447 4448 (void) pcd->pcd_config_pmc(cpu, adjri, NULL); 4449 } 4450 4451 /* 4452 * Inform the MD layer of this pseudo "context switch 4453 * out" 4454 */ 4455 (void) md->pmd_switch_out(pmc_pcpu[cpu], pp); 4456 4457 critical_exit(); /* ok to be pre-empted now */ 4458 4459 /* 4460 * Unlink this process from the PMCs that are 4461 * targetting it. This will send a signal to 4462 * all PMC owner's whose PMCs are orphaned. 4463 * 4464 * Log PMC value at exit time if requested. 4465 */ 4466 for (ri = 0; ri < md->pmd_npmc; ri++) 4467 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) { 4468 if (pm->pm_flags & PMC_F_NEEDS_LOGFILE && 4469 PMC_IS_COUNTING_MODE(PMC_TO_MODE(pm))) 4470 pmclog_process_procexit(pm, pp); 4471 pmc_unlink_target_process(pm, pp); 4472 } 4473 free(pp, M_PMC); 4474 4475 } else 4476 critical_exit(); /* pp == NULL */ 4477 4478 4479 /* 4480 * If the process owned PMCs, free them up and free up 4481 * memory. 4482 */ 4483 if ((po = pmc_find_owner_descriptor(p)) != NULL) { 4484 pmc_remove_owner(po); 4485 pmc_destroy_owner_descriptor(po); 4486 } 4487 4488 sx_xunlock(&pmc_sx); 4489 } 4490 4491 /* 4492 * Handle a process fork. 4493 * 4494 * If the parent process 'p1' is under HWPMC monitoring, then copy 4495 * over any attached PMCs that have 'do_descendants' semantics. 4496 */ 4497 4498 static void 4499 pmc_process_fork(void *arg __unused, struct proc *p1, struct proc *newproc, 4500 int flags) 4501 { 4502 int is_using_hwpmcs; 4503 unsigned int ri; 4504 uint32_t do_descendants; 4505 struct pmc *pm; 4506 struct pmc_owner *po; 4507 struct pmc_process *ppnew, *ppold; 4508 4509 (void) flags; /* unused parameter */ 4510 4511 PROC_LOCK(p1); 4512 is_using_hwpmcs = p1->p_flag & P_HWPMC; 4513 PROC_UNLOCK(p1); 4514 4515 /* 4516 * If there are system-wide sampling PMCs active, we need to 4517 * log all fork events to their owner's logs. 4518 */ 4519 4520 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 4521 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 4522 pmclog_process_procfork(po, p1->p_pid, newproc->p_pid); 4523 4524 if (!is_using_hwpmcs) 4525 return; 4526 4527 PMC_GET_SX_XLOCK(); 4528 PMCDBG(PMC,FRK,1, "process-fork proc=%p (%d, %s) -> %p", p1, 4529 p1->p_pid, p1->p_comm, newproc); 4530 4531 /* 4532 * If the parent process (curthread->td_proc) is a 4533 * target of any PMCs, look for PMCs that are to be 4534 * inherited, and link these into the new process 4535 * descriptor. 4536 */ 4537 if ((ppold = pmc_find_process_descriptor(curthread->td_proc, 4538 PMC_FLAG_NONE)) == NULL) 4539 goto done; /* nothing to do */ 4540 4541 do_descendants = 0; 4542 for (ri = 0; ri < md->pmd_npmc; ri++) 4543 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL) 4544 do_descendants |= pm->pm_flags & PMC_F_DESCENDANTS; 4545 if (do_descendants == 0) /* nothing to do */ 4546 goto done; 4547 4548 /* allocate a descriptor for the new process */ 4549 if ((ppnew = pmc_find_process_descriptor(newproc, 4550 PMC_FLAG_ALLOCATE)) == NULL) 4551 goto done; 4552 4553 /* 4554 * Run through all PMCs that were targeting the old process 4555 * and which specified F_DESCENDANTS and attach them to the 4556 * new process. 4557 * 4558 * Log the fork event to all owners of PMCs attached to this 4559 * process, if not already logged. 4560 */ 4561 for (ri = 0; ri < md->pmd_npmc; ri++) 4562 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL && 4563 (pm->pm_flags & PMC_F_DESCENDANTS)) { 4564 pmc_link_target_process(pm, ppnew); 4565 po = pm->pm_owner; 4566 if (po->po_sscount == 0 && 4567 po->po_flags & PMC_PO_OWNS_LOGFILE) 4568 pmclog_process_procfork(po, p1->p_pid, 4569 newproc->p_pid); 4570 } 4571 4572 /* 4573 * Now mark the new process as being tracked by this driver. 4574 */ 4575 PROC_LOCK(newproc); 4576 newproc->p_flag |= P_HWPMC; 4577 PROC_UNLOCK(newproc); 4578 4579 done: 4580 sx_xunlock(&pmc_sx); 4581 } 4582 4583 static void 4584 pmc_kld_load(void *arg __unused, linker_file_t lf) 4585 { 4586 struct pmc_owner *po; 4587 4588 sx_slock(&pmc_sx); 4589 4590 /* 4591 * Notify owners of system sampling PMCs about KLD operations. 4592 */ 4593 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 4594 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 4595 pmclog_process_map_in(po, (pid_t) -1, 4596 (uintfptr_t) lf->address, lf->filename); 4597 4598 /* 4599 * TODO: Notify owners of (all) process-sampling PMCs too. 4600 */ 4601 4602 sx_sunlock(&pmc_sx); 4603 } 4604 4605 static void 4606 pmc_kld_unload(void *arg __unused, const char *filename __unused, 4607 caddr_t address, size_t size) 4608 { 4609 struct pmc_owner *po; 4610 4611 sx_slock(&pmc_sx); 4612 4613 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 4614 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 4615 pmclog_process_map_out(po, (pid_t) -1, 4616 (uintfptr_t) address, (uintfptr_t) address + size); 4617 4618 /* 4619 * TODO: Notify owners of process-sampling PMCs. 4620 */ 4621 4622 sx_sunlock(&pmc_sx); 4623 } 4624 4625 /* 4626 * initialization 4627 */ 4628 4629 static const char *pmc_name_of_pmcclass[] = { 4630 #undef __PMC_CLASS 4631 #define __PMC_CLASS(N) #N , 4632 __PMC_CLASSES() 4633 }; 4634 4635 /* 4636 * Base class initializer: allocate structure and set default classes. 4637 */ 4638 struct pmc_mdep * 4639 pmc_mdep_alloc(int nclasses) 4640 { 4641 struct pmc_mdep *md; 4642 int n; 4643 4644 /* SOFT + md classes */ 4645 n = 1 + nclasses; 4646 md = malloc(sizeof(struct pmc_mdep) + n * 4647 sizeof(struct pmc_classdep), M_PMC, M_WAITOK|M_ZERO); 4648 md->pmd_nclass = n; 4649 4650 /* Add base class. */ 4651 pmc_soft_initialize(md); 4652 return md; 4653 } 4654 4655 void 4656 pmc_mdep_free(struct pmc_mdep *md) 4657 { 4658 pmc_soft_finalize(md); 4659 free(md, M_PMC); 4660 } 4661 4662 static int 4663 generic_switch_in(struct pmc_cpu *pc, struct pmc_process *pp) 4664 { 4665 (void) pc; (void) pp; 4666 4667 return (0); 4668 } 4669 4670 static int 4671 generic_switch_out(struct pmc_cpu *pc, struct pmc_process *pp) 4672 { 4673 (void) pc; (void) pp; 4674 4675 return (0); 4676 } 4677 4678 static struct pmc_mdep * 4679 pmc_generic_cpu_initialize(void) 4680 { 4681 struct pmc_mdep *md; 4682 4683 md = pmc_mdep_alloc(0); 4684 4685 md->pmd_cputype = PMC_CPU_GENERIC; 4686 4687 md->pmd_pcpu_init = NULL; 4688 md->pmd_pcpu_fini = NULL; 4689 md->pmd_switch_in = generic_switch_in; 4690 md->pmd_switch_out = generic_switch_out; 4691 4692 return (md); 4693 } 4694 4695 static void 4696 pmc_generic_cpu_finalize(struct pmc_mdep *md) 4697 { 4698 (void) md; 4699 } 4700 4701 4702 static int 4703 pmc_initialize(void) 4704 { 4705 int c, cpu, error, n, ri; 4706 unsigned int maxcpu; 4707 struct pmc_binding pb; 4708 struct pmc_sample *ps; 4709 struct pmc_classdep *pcd; 4710 struct pmc_samplebuffer *sb; 4711 4712 md = NULL; 4713 error = 0; 4714 4715 #ifdef DEBUG 4716 /* parse debug flags first */ 4717 if (TUNABLE_STR_FETCH(PMC_SYSCTL_NAME_PREFIX "debugflags", 4718 pmc_debugstr, sizeof(pmc_debugstr))) 4719 pmc_debugflags_parse(pmc_debugstr, 4720 pmc_debugstr+strlen(pmc_debugstr)); 4721 #endif 4722 4723 PMCDBG(MOD,INI,0, "PMC Initialize (version %x)", PMC_VERSION); 4724 4725 /* check kernel version */ 4726 if (pmc_kernel_version != PMC_VERSION) { 4727 if (pmc_kernel_version == 0) 4728 printf("hwpmc: this kernel has not been compiled with " 4729 "'options HWPMC_HOOKS'.\n"); 4730 else 4731 printf("hwpmc: kernel version (0x%x) does not match " 4732 "module version (0x%x).\n", pmc_kernel_version, 4733 PMC_VERSION); 4734 return EPROGMISMATCH; 4735 } 4736 4737 /* 4738 * check sysctl parameters 4739 */ 4740 4741 if (pmc_hashsize <= 0) { 4742 (void) printf("hwpmc: tunable \"hashsize\"=%d must be " 4743 "greater than zero.\n", pmc_hashsize); 4744 pmc_hashsize = PMC_HASH_SIZE; 4745 } 4746 4747 if (pmc_nsamples <= 0 || pmc_nsamples > 65535) { 4748 (void) printf("hwpmc: tunable \"nsamples\"=%d out of " 4749 "range.\n", pmc_nsamples); 4750 pmc_nsamples = PMC_NSAMPLES; 4751 } 4752 4753 if (pmc_callchaindepth <= 0 || 4754 pmc_callchaindepth > PMC_CALLCHAIN_DEPTH_MAX) { 4755 (void) printf("hwpmc: tunable \"callchaindepth\"=%d out of " 4756 "range - using %d.\n", pmc_callchaindepth, 4757 PMC_CALLCHAIN_DEPTH_MAX); 4758 pmc_callchaindepth = PMC_CALLCHAIN_DEPTH_MAX; 4759 } 4760 4761 md = pmc_md_initialize(); 4762 if (md == NULL) { 4763 /* Default to generic CPU. */ 4764 md = pmc_generic_cpu_initialize(); 4765 if (md == NULL) 4766 return (ENOSYS); 4767 } 4768 4769 KASSERT(md->pmd_nclass >= 1 && md->pmd_npmc >= 1, 4770 ("[pmc,%d] no classes or pmcs", __LINE__)); 4771 4772 /* Compute the map from row-indices to classdep pointers. */ 4773 pmc_rowindex_to_classdep = malloc(sizeof(struct pmc_classdep *) * 4774 md->pmd_npmc, M_PMC, M_WAITOK|M_ZERO); 4775 4776 for (n = 0; n < md->pmd_npmc; n++) 4777 pmc_rowindex_to_classdep[n] = NULL; 4778 for (ri = c = 0; c < md->pmd_nclass; c++) { 4779 pcd = &md->pmd_classdep[c]; 4780 for (n = 0; n < pcd->pcd_num; n++, ri++) 4781 pmc_rowindex_to_classdep[ri] = pcd; 4782 } 4783 4784 KASSERT(ri == md->pmd_npmc, 4785 ("[pmc,%d] npmc miscomputed: ri=%d, md->npmc=%d", __LINE__, 4786 ri, md->pmd_npmc)); 4787 4788 maxcpu = pmc_cpu_max(); 4789 4790 /* allocate space for the per-cpu array */ 4791 pmc_pcpu = malloc(maxcpu * sizeof(struct pmc_cpu *), M_PMC, 4792 M_WAITOK|M_ZERO); 4793 4794 /* per-cpu 'saved values' for managing process-mode PMCs */ 4795 pmc_pcpu_saved = malloc(sizeof(pmc_value_t) * maxcpu * md->pmd_npmc, 4796 M_PMC, M_WAITOK); 4797 4798 /* Perform CPU-dependent initialization. */ 4799 pmc_save_cpu_binding(&pb); 4800 error = 0; 4801 for (cpu = 0; error == 0 && cpu < maxcpu; cpu++) { 4802 if (!pmc_cpu_is_active(cpu)) 4803 continue; 4804 pmc_select_cpu(cpu); 4805 pmc_pcpu[cpu] = malloc(sizeof(struct pmc_cpu) + 4806 md->pmd_npmc * sizeof(struct pmc_hw *), M_PMC, 4807 M_WAITOK|M_ZERO); 4808 if (md->pmd_pcpu_init) 4809 error = md->pmd_pcpu_init(md, cpu); 4810 for (n = 0; error == 0 && n < md->pmd_nclass; n++) 4811 error = md->pmd_classdep[n].pcd_pcpu_init(md, cpu); 4812 } 4813 pmc_restore_cpu_binding(&pb); 4814 4815 if (error) 4816 return (error); 4817 4818 /* allocate space for the sample array */ 4819 for (cpu = 0; cpu < maxcpu; cpu++) { 4820 if (!pmc_cpu_is_active(cpu)) 4821 continue; 4822 4823 sb = malloc(sizeof(struct pmc_samplebuffer) + 4824 pmc_nsamples * sizeof(struct pmc_sample), M_PMC, 4825 M_WAITOK|M_ZERO); 4826 sb->ps_read = sb->ps_write = sb->ps_samples; 4827 sb->ps_fence = sb->ps_samples + pmc_nsamples; 4828 4829 KASSERT(pmc_pcpu[cpu] != NULL, 4830 ("[pmc,%d] cpu=%d Null per-cpu data", __LINE__, cpu)); 4831 4832 sb->ps_callchains = malloc(pmc_callchaindepth * pmc_nsamples * 4833 sizeof(uintptr_t), M_PMC, M_WAITOK|M_ZERO); 4834 4835 for (n = 0, ps = sb->ps_samples; n < pmc_nsamples; n++, ps++) 4836 ps->ps_pc = sb->ps_callchains + 4837 (n * pmc_callchaindepth); 4838 4839 pmc_pcpu[cpu]->pc_sb[PMC_HR] = sb; 4840 4841 sb = malloc(sizeof(struct pmc_samplebuffer) + 4842 pmc_nsamples * sizeof(struct pmc_sample), M_PMC, 4843 M_WAITOK|M_ZERO); 4844 sb->ps_read = sb->ps_write = sb->ps_samples; 4845 sb->ps_fence = sb->ps_samples + pmc_nsamples; 4846 4847 KASSERT(pmc_pcpu[cpu] != NULL, 4848 ("[pmc,%d] cpu=%d Null per-cpu data", __LINE__, cpu)); 4849 4850 sb->ps_callchains = malloc(pmc_callchaindepth * pmc_nsamples * 4851 sizeof(uintptr_t), M_PMC, M_WAITOK|M_ZERO); 4852 4853 for (n = 0, ps = sb->ps_samples; n < pmc_nsamples; n++, ps++) 4854 ps->ps_pc = sb->ps_callchains + 4855 (n * pmc_callchaindepth); 4856 4857 pmc_pcpu[cpu]->pc_sb[PMC_SR] = sb; 4858 } 4859 4860 /* allocate space for the row disposition array */ 4861 pmc_pmcdisp = malloc(sizeof(enum pmc_mode) * md->pmd_npmc, 4862 M_PMC, M_WAITOK|M_ZERO); 4863 4864 /* mark all PMCs as available */ 4865 for (n = 0; n < (int) md->pmd_npmc; n++) 4866 PMC_MARK_ROW_FREE(n); 4867 4868 /* allocate thread hash tables */ 4869 pmc_ownerhash = hashinit(pmc_hashsize, M_PMC, 4870 &pmc_ownerhashmask); 4871 4872 pmc_processhash = hashinit(pmc_hashsize, M_PMC, 4873 &pmc_processhashmask); 4874 mtx_init(&pmc_processhash_mtx, "pmc-process-hash", "pmc-leaf", 4875 MTX_SPIN); 4876 4877 LIST_INIT(&pmc_ss_owners); 4878 pmc_ss_count = 0; 4879 4880 /* allocate a pool of spin mutexes */ 4881 pmc_mtxpool = mtx_pool_create("pmc-leaf", pmc_mtxpool_size, 4882 MTX_SPIN); 4883 4884 PMCDBG(MOD,INI,1, "pmc_ownerhash=%p, mask=0x%lx " 4885 "targethash=%p mask=0x%lx", pmc_ownerhash, pmc_ownerhashmask, 4886 pmc_processhash, pmc_processhashmask); 4887 4888 /* register process {exit,fork,exec} handlers */ 4889 pmc_exit_tag = EVENTHANDLER_REGISTER(process_exit, 4890 pmc_process_exit, NULL, EVENTHANDLER_PRI_ANY); 4891 pmc_fork_tag = EVENTHANDLER_REGISTER(process_fork, 4892 pmc_process_fork, NULL, EVENTHANDLER_PRI_ANY); 4893 4894 /* register kld event handlers */ 4895 pmc_kld_load_tag = EVENTHANDLER_REGISTER(kld_load, pmc_kld_load, 4896 NULL, EVENTHANDLER_PRI_ANY); 4897 pmc_kld_unload_tag = EVENTHANDLER_REGISTER(kld_unload, pmc_kld_unload, 4898 NULL, EVENTHANDLER_PRI_ANY); 4899 4900 /* initialize logging */ 4901 pmclog_initialize(); 4902 4903 /* set hook functions */ 4904 pmc_intr = md->pmd_intr; 4905 pmc_hook = pmc_hook_handler; 4906 4907 if (error == 0) { 4908 printf(PMC_MODULE_NAME ":"); 4909 for (n = 0; n < (int) md->pmd_nclass; n++) { 4910 pcd = &md->pmd_classdep[n]; 4911 printf(" %s/%d/%d/0x%b", 4912 pmc_name_of_pmcclass[pcd->pcd_class], 4913 pcd->pcd_num, 4914 pcd->pcd_width, 4915 pcd->pcd_caps, 4916 "\20" 4917 "\1INT\2USR\3SYS\4EDG\5THR" 4918 "\6REA\7WRI\10INV\11QUA\12PRC" 4919 "\13TAG\14CSC"); 4920 } 4921 printf("\n"); 4922 } 4923 4924 return (error); 4925 } 4926 4927 /* prepare to be unloaded */ 4928 static void 4929 pmc_cleanup(void) 4930 { 4931 int c, cpu; 4932 unsigned int maxcpu; 4933 struct pmc_ownerhash *ph; 4934 struct pmc_owner *po, *tmp; 4935 struct pmc_binding pb; 4936 #ifdef DEBUG 4937 struct pmc_processhash *prh; 4938 #endif 4939 4940 PMCDBG(MOD,INI,0, "%s", "cleanup"); 4941 4942 /* switch off sampling */ 4943 CPU_ZERO(&pmc_cpumask); 4944 pmc_intr = NULL; 4945 4946 sx_xlock(&pmc_sx); 4947 if (pmc_hook == NULL) { /* being unloaded already */ 4948 sx_xunlock(&pmc_sx); 4949 return; 4950 } 4951 4952 pmc_hook = NULL; /* prevent new threads from entering module */ 4953 4954 /* deregister event handlers */ 4955 EVENTHANDLER_DEREGISTER(process_fork, pmc_fork_tag); 4956 EVENTHANDLER_DEREGISTER(process_exit, pmc_exit_tag); 4957 EVENTHANDLER_DEREGISTER(kld_load, pmc_kld_load_tag); 4958 EVENTHANDLER_DEREGISTER(kld_unload, pmc_kld_unload_tag); 4959 4960 /* send SIGBUS to all owner threads, free up allocations */ 4961 if (pmc_ownerhash) 4962 for (ph = pmc_ownerhash; 4963 ph <= &pmc_ownerhash[pmc_ownerhashmask]; 4964 ph++) { 4965 LIST_FOREACH_SAFE(po, ph, po_next, tmp) { 4966 pmc_remove_owner(po); 4967 4968 /* send SIGBUS to owner processes */ 4969 PMCDBG(MOD,INI,2, "cleanup signal proc=%p " 4970 "(%d, %s)", po->po_owner, 4971 po->po_owner->p_pid, 4972 po->po_owner->p_comm); 4973 4974 PROC_LOCK(po->po_owner); 4975 kern_psignal(po->po_owner, SIGBUS); 4976 PROC_UNLOCK(po->po_owner); 4977 4978 pmc_destroy_owner_descriptor(po); 4979 } 4980 } 4981 4982 /* reclaim allocated data structures */ 4983 if (pmc_mtxpool) 4984 mtx_pool_destroy(&pmc_mtxpool); 4985 4986 mtx_destroy(&pmc_processhash_mtx); 4987 if (pmc_processhash) { 4988 #ifdef DEBUG 4989 struct pmc_process *pp; 4990 4991 PMCDBG(MOD,INI,3, "%s", "destroy process hash"); 4992 for (prh = pmc_processhash; 4993 prh <= &pmc_processhash[pmc_processhashmask]; 4994 prh++) 4995 LIST_FOREACH(pp, prh, pp_next) 4996 PMCDBG(MOD,INI,3, "pid=%d", pp->pp_proc->p_pid); 4997 #endif 4998 4999 hashdestroy(pmc_processhash, M_PMC, pmc_processhashmask); 5000 pmc_processhash = NULL; 5001 } 5002 5003 if (pmc_ownerhash) { 5004 PMCDBG(MOD,INI,3, "%s", "destroy owner hash"); 5005 hashdestroy(pmc_ownerhash, M_PMC, pmc_ownerhashmask); 5006 pmc_ownerhash = NULL; 5007 } 5008 5009 KASSERT(LIST_EMPTY(&pmc_ss_owners), 5010 ("[pmc,%d] Global SS owner list not empty", __LINE__)); 5011 KASSERT(pmc_ss_count == 0, 5012 ("[pmc,%d] Global SS count not empty", __LINE__)); 5013 5014 /* do processor and pmc-class dependent cleanup */ 5015 maxcpu = pmc_cpu_max(); 5016 5017 PMCDBG(MOD,INI,3, "%s", "md cleanup"); 5018 if (md) { 5019 pmc_save_cpu_binding(&pb); 5020 for (cpu = 0; cpu < maxcpu; cpu++) { 5021 PMCDBG(MOD,INI,1,"pmc-cleanup cpu=%d pcs=%p", 5022 cpu, pmc_pcpu[cpu]); 5023 if (!pmc_cpu_is_active(cpu) || pmc_pcpu[cpu] == NULL) 5024 continue; 5025 pmc_select_cpu(cpu); 5026 for (c = 0; c < md->pmd_nclass; c++) 5027 md->pmd_classdep[c].pcd_pcpu_fini(md, cpu); 5028 if (md->pmd_pcpu_fini) 5029 md->pmd_pcpu_fini(md, cpu); 5030 } 5031 5032 if (md->pmd_cputype == PMC_CPU_GENERIC) 5033 pmc_generic_cpu_finalize(md); 5034 else 5035 pmc_md_finalize(md); 5036 5037 pmc_mdep_free(md); 5038 md = NULL; 5039 pmc_restore_cpu_binding(&pb); 5040 } 5041 5042 /* Free per-cpu descriptors. */ 5043 for (cpu = 0; cpu < maxcpu; cpu++) { 5044 if (!pmc_cpu_is_active(cpu)) 5045 continue; 5046 KASSERT(pmc_pcpu[cpu]->pc_sb[PMC_HR] != NULL, 5047 ("[pmc,%d] Null hw cpu sample buffer cpu=%d", __LINE__, 5048 cpu)); 5049 KASSERT(pmc_pcpu[cpu]->pc_sb[PMC_SR] != NULL, 5050 ("[pmc,%d] Null sw cpu sample buffer cpu=%d", __LINE__, 5051 cpu)); 5052 free(pmc_pcpu[cpu]->pc_sb[PMC_HR]->ps_callchains, M_PMC); 5053 free(pmc_pcpu[cpu]->pc_sb[PMC_HR], M_PMC); 5054 free(pmc_pcpu[cpu]->pc_sb[PMC_SR]->ps_callchains, M_PMC); 5055 free(pmc_pcpu[cpu]->pc_sb[PMC_SR], M_PMC); 5056 free(pmc_pcpu[cpu], M_PMC); 5057 } 5058 5059 free(pmc_pcpu, M_PMC); 5060 pmc_pcpu = NULL; 5061 5062 free(pmc_pcpu_saved, M_PMC); 5063 pmc_pcpu_saved = NULL; 5064 5065 if (pmc_pmcdisp) { 5066 free(pmc_pmcdisp, M_PMC); 5067 pmc_pmcdisp = NULL; 5068 } 5069 5070 if (pmc_rowindex_to_classdep) { 5071 free(pmc_rowindex_to_classdep, M_PMC); 5072 pmc_rowindex_to_classdep = NULL; 5073 } 5074 5075 pmclog_shutdown(); 5076 5077 sx_xunlock(&pmc_sx); /* we are done */ 5078 } 5079 5080 /* 5081 * The function called at load/unload. 5082 */ 5083 5084 static int 5085 load (struct module *module __unused, int cmd, void *arg __unused) 5086 { 5087 int error; 5088 5089 error = 0; 5090 5091 switch (cmd) { 5092 case MOD_LOAD : 5093 /* initialize the subsystem */ 5094 error = pmc_initialize(); 5095 if (error != 0) 5096 break; 5097 PMCDBG(MOD,INI,1, "syscall=%d maxcpu=%d", 5098 pmc_syscall_num, pmc_cpu_max()); 5099 break; 5100 5101 5102 case MOD_UNLOAD : 5103 case MOD_SHUTDOWN: 5104 pmc_cleanup(); 5105 PMCDBG(MOD,INI,1, "%s", "unloaded"); 5106 break; 5107 5108 default : 5109 error = EINVAL; /* XXX should panic(9) */ 5110 break; 5111 } 5112 5113 return error; 5114 } 5115 5116 /* memory pool */ 5117 MALLOC_DEFINE(M_PMC, "pmc", "Memory space for the PMC module"); 5118