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