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_WLOCK(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_WLOCK(tobj); 1684 if (lobj != obj) 1685 VM_OBJECT_WUNLOCK(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_WUNLOCK(obj); 1696 continue; 1697 } 1698 1699 if (lobj->type != OBJT_VNODE || lobj->handle == NULL) { 1700 if (lobj != obj) 1701 VM_OBJECT_WUNLOCK(lobj); 1702 VM_OBJECT_WUNLOCK(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_WUNLOCK(lobj); 1715 VM_OBJECT_WUNLOCK(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_WUNLOCK(lobj); 1738 1739 VM_OBJECT_WUNLOCK(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 2214 if (pmc != NULL) { 2215 pmc->pm_owner = NULL; 2216 LIST_INIT(&pmc->pm_targets); 2217 } 2218 2219 PMCDBG(PMC,ALL,1, "allocate-pmc -> pmc=%p", pmc); 2220 2221 return pmc; 2222 } 2223 2224 /* 2225 * Destroy a pmc descriptor. 2226 */ 2227 2228 static void 2229 pmc_destroy_pmc_descriptor(struct pmc *pm) 2230 { 2231 (void) pm; 2232 2233 #ifdef DEBUG 2234 KASSERT(pm->pm_state == PMC_STATE_DELETED || 2235 pm->pm_state == PMC_STATE_FREE, 2236 ("[pmc,%d] destroying non-deleted PMC", __LINE__)); 2237 KASSERT(LIST_EMPTY(&pm->pm_targets), 2238 ("[pmc,%d] destroying pmc with targets", __LINE__)); 2239 KASSERT(pm->pm_owner == NULL, 2240 ("[pmc,%d] destroying pmc attached to an owner", __LINE__)); 2241 KASSERT(pm->pm_runcount == 0, 2242 ("[pmc,%d] pmc has non-zero run count %d", __LINE__, 2243 pm->pm_runcount)); 2244 #endif 2245 } 2246 2247 static void 2248 pmc_wait_for_pmc_idle(struct pmc *pm) 2249 { 2250 #ifdef DEBUG 2251 volatile int maxloop; 2252 2253 maxloop = 100 * pmc_cpu_max(); 2254 #endif 2255 /* 2256 * Loop (with a forced context switch) till the PMC's runcount 2257 * comes down to zero. 2258 */ 2259 while (atomic_load_acq_32(&pm->pm_runcount) > 0) { 2260 #ifdef DEBUG 2261 maxloop--; 2262 KASSERT(maxloop > 0, 2263 ("[pmc,%d] (ri%d, rc%d) waiting too long for " 2264 "pmc to be free", __LINE__, 2265 PMC_TO_ROWINDEX(pm), pm->pm_runcount)); 2266 #endif 2267 pmc_force_context_switch(); 2268 } 2269 } 2270 2271 /* 2272 * This function does the following things: 2273 * 2274 * - detaches the PMC from hardware 2275 * - unlinks all target threads that were attached to it 2276 * - removes the PMC from its owner's list 2277 * - destroy's the PMC private mutex 2278 * 2279 * Once this function completes, the given pmc pointer can be safely 2280 * FREE'd by the caller. 2281 */ 2282 2283 static void 2284 pmc_release_pmc_descriptor(struct pmc *pm) 2285 { 2286 enum pmc_mode mode; 2287 struct pmc_hw *phw; 2288 u_int adjri, ri, cpu; 2289 struct pmc_owner *po; 2290 struct pmc_binding pb; 2291 struct pmc_process *pp; 2292 struct pmc_classdep *pcd; 2293 struct pmc_target *ptgt, *tmp; 2294 2295 sx_assert(&pmc_sx, SX_XLOCKED); 2296 2297 KASSERT(pm, ("[pmc,%d] null pmc", __LINE__)); 2298 2299 ri = PMC_TO_ROWINDEX(pm); 2300 pcd = pmc_ri_to_classdep(md, ri, &adjri); 2301 mode = PMC_TO_MODE(pm); 2302 2303 PMCDBG(PMC,REL,1, "release-pmc pmc=%p ri=%d mode=%d", pm, ri, 2304 mode); 2305 2306 /* 2307 * First, we take the PMC off hardware. 2308 */ 2309 cpu = 0; 2310 if (PMC_IS_SYSTEM_MODE(mode)) { 2311 2312 /* 2313 * A system mode PMC runs on a specific CPU. Switch 2314 * to this CPU and turn hardware off. 2315 */ 2316 pmc_save_cpu_binding(&pb); 2317 2318 cpu = PMC_TO_CPU(pm); 2319 2320 pmc_select_cpu(cpu); 2321 2322 /* switch off non-stalled CPUs */ 2323 if (pm->pm_state == PMC_STATE_RUNNING && 2324 pm->pm_stalled == 0) { 2325 2326 phw = pmc_pcpu[cpu]->pc_hwpmcs[ri]; 2327 2328 KASSERT(phw->phw_pmc == pm, 2329 ("[pmc, %d] pmc ptr ri(%d) hw(%p) pm(%p)", 2330 __LINE__, ri, phw->phw_pmc, pm)); 2331 PMCDBG(PMC,REL,2, "stopping cpu=%d ri=%d", cpu, ri); 2332 2333 critical_enter(); 2334 pcd->pcd_stop_pmc(cpu, adjri); 2335 critical_exit(); 2336 } 2337 2338 PMCDBG(PMC,REL,2, "decfg cpu=%d ri=%d", cpu, ri); 2339 2340 critical_enter(); 2341 pcd->pcd_config_pmc(cpu, adjri, NULL); 2342 critical_exit(); 2343 2344 /* adjust the global and process count of SS mode PMCs */ 2345 if (mode == PMC_MODE_SS && pm->pm_state == PMC_STATE_RUNNING) { 2346 po = pm->pm_owner; 2347 po->po_sscount--; 2348 if (po->po_sscount == 0) { 2349 atomic_subtract_rel_int(&pmc_ss_count, 1); 2350 LIST_REMOVE(po, po_ssnext); 2351 } 2352 } 2353 2354 pm->pm_state = PMC_STATE_DELETED; 2355 2356 pmc_restore_cpu_binding(&pb); 2357 2358 /* 2359 * We could have references to this PMC structure in 2360 * the per-cpu sample queues. Wait for the queue to 2361 * drain. 2362 */ 2363 pmc_wait_for_pmc_idle(pm); 2364 2365 } else if (PMC_IS_VIRTUAL_MODE(mode)) { 2366 2367 /* 2368 * A virtual PMC could be running on multiple CPUs at 2369 * a given instant. 2370 * 2371 * By marking its state as DELETED, we ensure that 2372 * this PMC is never further scheduled on hardware. 2373 * 2374 * Then we wait till all CPUs are done with this PMC. 2375 */ 2376 pm->pm_state = PMC_STATE_DELETED; 2377 2378 2379 /* Wait for the PMCs runcount to come to zero. */ 2380 pmc_wait_for_pmc_idle(pm); 2381 2382 /* 2383 * At this point the PMC is off all CPUs and cannot be 2384 * freshly scheduled onto a CPU. It is now safe to 2385 * unlink all targets from this PMC. If a 2386 * process-record's refcount falls to zero, we remove 2387 * it from the hash table. The module-wide SX lock 2388 * protects us from races. 2389 */ 2390 LIST_FOREACH_SAFE(ptgt, &pm->pm_targets, pt_next, tmp) { 2391 pp = ptgt->pt_process; 2392 pmc_unlink_target_process(pm, pp); /* frees 'ptgt' */ 2393 2394 PMCDBG(PMC,REL,3, "pp->refcnt=%d", pp->pp_refcnt); 2395 2396 /* 2397 * If the target process record shows that no 2398 * PMCs are attached to it, reclaim its space. 2399 */ 2400 2401 if (pp->pp_refcnt == 0) { 2402 pmc_remove_process_descriptor(pp); 2403 free(pp, M_PMC); 2404 } 2405 } 2406 2407 cpu = curthread->td_oncpu; /* setup cpu for pmd_release() */ 2408 2409 } 2410 2411 /* 2412 * Release any MD resources 2413 */ 2414 (void) pcd->pcd_release_pmc(cpu, adjri, pm); 2415 2416 /* 2417 * Update row disposition 2418 */ 2419 2420 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) 2421 PMC_UNMARK_ROW_STANDALONE(ri); 2422 else 2423 PMC_UNMARK_ROW_THREAD(ri); 2424 2425 /* unlink from the owner's list */ 2426 if (pm->pm_owner) { 2427 LIST_REMOVE(pm, pm_next); 2428 pm->pm_owner = NULL; 2429 } 2430 2431 pmc_destroy_pmc_descriptor(pm); 2432 } 2433 2434 /* 2435 * Register an owner and a pmc. 2436 */ 2437 2438 static int 2439 pmc_register_owner(struct proc *p, struct pmc *pmc) 2440 { 2441 struct pmc_owner *po; 2442 2443 sx_assert(&pmc_sx, SX_XLOCKED); 2444 2445 if ((po = pmc_find_owner_descriptor(p)) == NULL) 2446 if ((po = pmc_allocate_owner_descriptor(p)) == NULL) 2447 return ENOMEM; 2448 2449 KASSERT(pmc->pm_owner == NULL, 2450 ("[pmc,%d] attempting to own an initialized PMC", __LINE__)); 2451 pmc->pm_owner = po; 2452 2453 LIST_INSERT_HEAD(&po->po_pmcs, pmc, pm_next); 2454 2455 PROC_LOCK(p); 2456 p->p_flag |= P_HWPMC; 2457 PROC_UNLOCK(p); 2458 2459 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 2460 pmclog_process_pmcallocate(pmc); 2461 2462 PMCDBG(PMC,REG,1, "register-owner pmc-owner=%p pmc=%p", 2463 po, pmc); 2464 2465 return 0; 2466 } 2467 2468 /* 2469 * Return the current row disposition: 2470 * == 0 => FREE 2471 * > 0 => PROCESS MODE 2472 * < 0 => SYSTEM MODE 2473 */ 2474 2475 int 2476 pmc_getrowdisp(int ri) 2477 { 2478 return pmc_pmcdisp[ri]; 2479 } 2480 2481 /* 2482 * Check if a PMC at row index 'ri' can be allocated to the current 2483 * process. 2484 * 2485 * Allocation can fail if: 2486 * - the current process is already being profiled by a PMC at index 'ri', 2487 * attached to it via OP_PMCATTACH. 2488 * - the current process has already allocated a PMC at index 'ri' 2489 * via OP_ALLOCATE. 2490 */ 2491 2492 static int 2493 pmc_can_allocate_rowindex(struct proc *p, unsigned int ri, int cpu) 2494 { 2495 enum pmc_mode mode; 2496 struct pmc *pm; 2497 struct pmc_owner *po; 2498 struct pmc_process *pp; 2499 2500 PMCDBG(PMC,ALR,1, "can-allocate-rowindex proc=%p (%d, %s) ri=%d " 2501 "cpu=%d", p, p->p_pid, p->p_comm, ri, cpu); 2502 2503 /* 2504 * We shouldn't have already allocated a process-mode PMC at 2505 * row index 'ri'. 2506 * 2507 * We shouldn't have allocated a system-wide PMC on the same 2508 * CPU and same RI. 2509 */ 2510 if ((po = pmc_find_owner_descriptor(p)) != NULL) 2511 LIST_FOREACH(pm, &po->po_pmcs, pm_next) { 2512 if (PMC_TO_ROWINDEX(pm) == ri) { 2513 mode = PMC_TO_MODE(pm); 2514 if (PMC_IS_VIRTUAL_MODE(mode)) 2515 return EEXIST; 2516 if (PMC_IS_SYSTEM_MODE(mode) && 2517 (int) PMC_TO_CPU(pm) == cpu) 2518 return EEXIST; 2519 } 2520 } 2521 2522 /* 2523 * We also shouldn't be the target of any PMC at this index 2524 * since otherwise a PMC_ATTACH to ourselves will fail. 2525 */ 2526 if ((pp = pmc_find_process_descriptor(p, 0)) != NULL) 2527 if (pp->pp_pmcs[ri].pp_pmc) 2528 return EEXIST; 2529 2530 PMCDBG(PMC,ALR,2, "can-allocate-rowindex proc=%p (%d, %s) ri=%d ok", 2531 p, p->p_pid, p->p_comm, ri); 2532 2533 return 0; 2534 } 2535 2536 /* 2537 * Check if a given PMC at row index 'ri' can be currently used in 2538 * mode 'mode'. 2539 */ 2540 2541 static int 2542 pmc_can_allocate_row(int ri, enum pmc_mode mode) 2543 { 2544 enum pmc_disp disp; 2545 2546 sx_assert(&pmc_sx, SX_XLOCKED); 2547 2548 PMCDBG(PMC,ALR,1, "can-allocate-row ri=%d mode=%d", ri, mode); 2549 2550 if (PMC_IS_SYSTEM_MODE(mode)) 2551 disp = PMC_DISP_STANDALONE; 2552 else 2553 disp = PMC_DISP_THREAD; 2554 2555 /* 2556 * check disposition for PMC row 'ri': 2557 * 2558 * Expected disposition Row-disposition Result 2559 * 2560 * STANDALONE STANDALONE or FREE proceed 2561 * STANDALONE THREAD fail 2562 * THREAD THREAD or FREE proceed 2563 * THREAD STANDALONE fail 2564 */ 2565 2566 if (!PMC_ROW_DISP_IS_FREE(ri) && 2567 !(disp == PMC_DISP_THREAD && PMC_ROW_DISP_IS_THREAD(ri)) && 2568 !(disp == PMC_DISP_STANDALONE && PMC_ROW_DISP_IS_STANDALONE(ri))) 2569 return EBUSY; 2570 2571 /* 2572 * All OK 2573 */ 2574 2575 PMCDBG(PMC,ALR,2, "can-allocate-row ri=%d mode=%d ok", ri, mode); 2576 2577 return 0; 2578 2579 } 2580 2581 /* 2582 * Find a PMC descriptor with user handle 'pmcid' for thread 'td'. 2583 */ 2584 2585 static struct pmc * 2586 pmc_find_pmc_descriptor_in_process(struct pmc_owner *po, pmc_id_t pmcid) 2587 { 2588 struct pmc *pm; 2589 2590 KASSERT(PMC_ID_TO_ROWINDEX(pmcid) < md->pmd_npmc, 2591 ("[pmc,%d] Illegal pmc index %d (max %d)", __LINE__, 2592 PMC_ID_TO_ROWINDEX(pmcid), md->pmd_npmc)); 2593 2594 LIST_FOREACH(pm, &po->po_pmcs, pm_next) 2595 if (pm->pm_id == pmcid) 2596 return pm; 2597 2598 return NULL; 2599 } 2600 2601 static int 2602 pmc_find_pmc(pmc_id_t pmcid, struct pmc **pmc) 2603 { 2604 2605 struct pmc *pm; 2606 struct pmc_owner *po; 2607 2608 PMCDBG(PMC,FND,1, "find-pmc id=%d", pmcid); 2609 2610 if ((po = pmc_find_owner_descriptor(curthread->td_proc)) == NULL) 2611 return ESRCH; 2612 2613 if ((pm = pmc_find_pmc_descriptor_in_process(po, pmcid)) == NULL) 2614 return EINVAL; 2615 2616 PMCDBG(PMC,FND,2, "find-pmc id=%d -> pmc=%p", pmcid, pm); 2617 2618 *pmc = pm; 2619 return 0; 2620 } 2621 2622 /* 2623 * Start a PMC. 2624 */ 2625 2626 static int 2627 pmc_start(struct pmc *pm) 2628 { 2629 enum pmc_mode mode; 2630 struct pmc_owner *po; 2631 struct pmc_binding pb; 2632 struct pmc_classdep *pcd; 2633 int adjri, error, cpu, ri; 2634 2635 KASSERT(pm != NULL, 2636 ("[pmc,%d] null pm", __LINE__)); 2637 2638 mode = PMC_TO_MODE(pm); 2639 ri = PMC_TO_ROWINDEX(pm); 2640 pcd = pmc_ri_to_classdep(md, ri, &adjri); 2641 2642 error = 0; 2643 2644 PMCDBG(PMC,OPS,1, "start pmc=%p mode=%d ri=%d", pm, mode, ri); 2645 2646 po = pm->pm_owner; 2647 2648 /* 2649 * Disallow PMCSTART if a logfile is required but has not been 2650 * configured yet. 2651 */ 2652 if ((pm->pm_flags & PMC_F_NEEDS_LOGFILE) && 2653 (po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) 2654 return (EDOOFUS); /* programming error */ 2655 2656 /* 2657 * If this is a sampling mode PMC, log mapping information for 2658 * the kernel modules that are currently loaded. 2659 */ 2660 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 2661 pmc_log_kernel_mappings(pm); 2662 2663 if (PMC_IS_VIRTUAL_MODE(mode)) { 2664 2665 /* 2666 * If a PMCATTACH has never been done on this PMC, 2667 * attach it to its owner process. 2668 */ 2669 2670 if (LIST_EMPTY(&pm->pm_targets)) 2671 error = (pm->pm_flags & PMC_F_ATTACH_DONE) ? ESRCH : 2672 pmc_attach_process(po->po_owner, pm); 2673 2674 /* 2675 * If the PMC is attached to its owner, then force a context 2676 * switch to ensure that the MD state gets set correctly. 2677 */ 2678 2679 if (error == 0) { 2680 pm->pm_state = PMC_STATE_RUNNING; 2681 if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) 2682 pmc_force_context_switch(); 2683 } 2684 2685 return (error); 2686 } 2687 2688 2689 /* 2690 * A system-wide PMC. 2691 * 2692 * Add the owner to the global list if this is a system-wide 2693 * sampling PMC. 2694 */ 2695 2696 if (mode == PMC_MODE_SS) { 2697 if (po->po_sscount == 0) { 2698 LIST_INSERT_HEAD(&pmc_ss_owners, po, po_ssnext); 2699 atomic_add_rel_int(&pmc_ss_count, 1); 2700 PMCDBG(PMC,OPS,1, "po=%p in global list", po); 2701 } 2702 po->po_sscount++; 2703 2704 /* 2705 * Log mapping information for all existing processes in the 2706 * system. Subsequent mappings are logged as they happen; 2707 * see pmc_process_mmap(). 2708 */ 2709 if (po->po_logprocmaps == 0) { 2710 pmc_log_all_process_mappings(po); 2711 po->po_logprocmaps = 1; 2712 } 2713 } 2714 2715 /* 2716 * Move to the CPU associated with this 2717 * PMC, and start the hardware. 2718 */ 2719 2720 pmc_save_cpu_binding(&pb); 2721 2722 cpu = PMC_TO_CPU(pm); 2723 2724 if (!pmc_cpu_is_active(cpu)) 2725 return (ENXIO); 2726 2727 pmc_select_cpu(cpu); 2728 2729 /* 2730 * global PMCs are configured at allocation time 2731 * so write out the initial value and start the PMC. 2732 */ 2733 2734 pm->pm_state = PMC_STATE_RUNNING; 2735 2736 critical_enter(); 2737 if ((error = pcd->pcd_write_pmc(cpu, adjri, 2738 PMC_IS_SAMPLING_MODE(mode) ? 2739 pm->pm_sc.pm_reloadcount : 2740 pm->pm_sc.pm_initial)) == 0) 2741 error = pcd->pcd_start_pmc(cpu, adjri); 2742 critical_exit(); 2743 2744 pmc_restore_cpu_binding(&pb); 2745 2746 return (error); 2747 } 2748 2749 /* 2750 * Stop a PMC. 2751 */ 2752 2753 static int 2754 pmc_stop(struct pmc *pm) 2755 { 2756 struct pmc_owner *po; 2757 struct pmc_binding pb; 2758 struct pmc_classdep *pcd; 2759 int adjri, cpu, error, ri; 2760 2761 KASSERT(pm != NULL, ("[pmc,%d] null pmc", __LINE__)); 2762 2763 PMCDBG(PMC,OPS,1, "stop pmc=%p mode=%d ri=%d", pm, 2764 PMC_TO_MODE(pm), PMC_TO_ROWINDEX(pm)); 2765 2766 pm->pm_state = PMC_STATE_STOPPED; 2767 2768 /* 2769 * If the PMC is a virtual mode one, changing the state to 2770 * non-RUNNING is enough to ensure that the PMC never gets 2771 * scheduled. 2772 * 2773 * If this PMC is current running on a CPU, then it will 2774 * handled correctly at the time its target process is context 2775 * switched out. 2776 */ 2777 2778 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) 2779 return 0; 2780 2781 /* 2782 * A system-mode PMC. Move to the CPU associated with 2783 * this PMC, and stop the hardware. We update the 2784 * 'initial count' so that a subsequent PMCSTART will 2785 * resume counting from the current hardware count. 2786 */ 2787 2788 pmc_save_cpu_binding(&pb); 2789 2790 cpu = PMC_TO_CPU(pm); 2791 2792 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 2793 ("[pmc,%d] illegal cpu=%d", __LINE__, cpu)); 2794 2795 if (!pmc_cpu_is_active(cpu)) 2796 return ENXIO; 2797 2798 pmc_select_cpu(cpu); 2799 2800 ri = PMC_TO_ROWINDEX(pm); 2801 pcd = pmc_ri_to_classdep(md, ri, &adjri); 2802 2803 critical_enter(); 2804 if ((error = pcd->pcd_stop_pmc(cpu, adjri)) == 0) 2805 error = pcd->pcd_read_pmc(cpu, adjri, &pm->pm_sc.pm_initial); 2806 critical_exit(); 2807 2808 pmc_restore_cpu_binding(&pb); 2809 2810 po = pm->pm_owner; 2811 2812 /* remove this owner from the global list of SS PMC owners */ 2813 if (PMC_TO_MODE(pm) == PMC_MODE_SS) { 2814 po->po_sscount--; 2815 if (po->po_sscount == 0) { 2816 atomic_subtract_rel_int(&pmc_ss_count, 1); 2817 LIST_REMOVE(po, po_ssnext); 2818 PMCDBG(PMC,OPS,2,"po=%p removed from global list", po); 2819 } 2820 } 2821 2822 return (error); 2823 } 2824 2825 2826 #ifdef DEBUG 2827 static const char *pmc_op_to_name[] = { 2828 #undef __PMC_OP 2829 #define __PMC_OP(N, D) #N , 2830 __PMC_OPS() 2831 NULL 2832 }; 2833 #endif 2834 2835 /* 2836 * The syscall interface 2837 */ 2838 2839 #define PMC_GET_SX_XLOCK(...) do { \ 2840 sx_xlock(&pmc_sx); \ 2841 if (pmc_hook == NULL) { \ 2842 sx_xunlock(&pmc_sx); \ 2843 return __VA_ARGS__; \ 2844 } \ 2845 } while (0) 2846 2847 #define PMC_DOWNGRADE_SX() do { \ 2848 sx_downgrade(&pmc_sx); \ 2849 is_sx_downgraded = 1; \ 2850 } while (0) 2851 2852 static int 2853 pmc_syscall_handler(struct thread *td, void *syscall_args) 2854 { 2855 int error, is_sx_downgraded, is_sx_locked, op; 2856 struct pmc_syscall_args *c; 2857 void *arg; 2858 2859 PMC_GET_SX_XLOCK(ENOSYS); 2860 2861 DROP_GIANT(); 2862 2863 is_sx_downgraded = 0; 2864 is_sx_locked = 1; 2865 2866 c = (struct pmc_syscall_args *) syscall_args; 2867 2868 op = c->pmop_code; 2869 arg = c->pmop_data; 2870 2871 PMCDBG(MOD,PMS,1, "syscall op=%d \"%s\" arg=%p", op, 2872 pmc_op_to_name[op], arg); 2873 2874 error = 0; 2875 atomic_add_int(&pmc_stats.pm_syscalls, 1); 2876 2877 switch(op) 2878 { 2879 2880 2881 /* 2882 * Configure a log file. 2883 * 2884 * XXX This OP will be reworked. 2885 */ 2886 2887 case PMC_OP_CONFIGURELOG: 2888 { 2889 struct proc *p; 2890 struct pmc *pm; 2891 struct pmc_owner *po; 2892 struct pmc_op_configurelog cl; 2893 2894 sx_assert(&pmc_sx, SX_XLOCKED); 2895 2896 if ((error = copyin(arg, &cl, sizeof(cl))) != 0) 2897 break; 2898 2899 /* mark this process as owning a log file */ 2900 p = td->td_proc; 2901 if ((po = pmc_find_owner_descriptor(p)) == NULL) 2902 if ((po = pmc_allocate_owner_descriptor(p)) == NULL) { 2903 error = ENOMEM; 2904 break; 2905 } 2906 2907 /* 2908 * If a valid fd was passed in, try to configure that, 2909 * otherwise if 'fd' was less than zero and there was 2910 * a log file configured, flush its buffers and 2911 * de-configure it. 2912 */ 2913 if (cl.pm_logfd >= 0) { 2914 sx_xunlock(&pmc_sx); 2915 is_sx_locked = 0; 2916 error = pmclog_configure_log(md, po, cl.pm_logfd); 2917 } else if (po->po_flags & PMC_PO_OWNS_LOGFILE) { 2918 pmclog_process_closelog(po); 2919 error = pmclog_close(po); 2920 if (error == 0) { 2921 LIST_FOREACH(pm, &po->po_pmcs, pm_next) 2922 if (pm->pm_flags & PMC_F_NEEDS_LOGFILE && 2923 pm->pm_state == PMC_STATE_RUNNING) 2924 pmc_stop(pm); 2925 error = pmclog_deconfigure_log(po); 2926 } 2927 } else 2928 error = EINVAL; 2929 2930 if (error) 2931 break; 2932 } 2933 break; 2934 2935 /* 2936 * Flush a log file. 2937 */ 2938 2939 case PMC_OP_FLUSHLOG: 2940 { 2941 struct pmc_owner *po; 2942 2943 sx_assert(&pmc_sx, SX_XLOCKED); 2944 2945 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 2946 error = EINVAL; 2947 break; 2948 } 2949 2950 error = pmclog_flush(po); 2951 } 2952 break; 2953 2954 /* 2955 * Close a log file. 2956 */ 2957 2958 case PMC_OP_CLOSELOG: 2959 { 2960 struct pmc_owner *po; 2961 2962 sx_assert(&pmc_sx, SX_XLOCKED); 2963 2964 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 2965 error = EINVAL; 2966 break; 2967 } 2968 2969 error = pmclog_close(po); 2970 } 2971 break; 2972 2973 /* 2974 * Retrieve hardware configuration. 2975 */ 2976 2977 case PMC_OP_GETCPUINFO: /* CPU information */ 2978 { 2979 struct pmc_op_getcpuinfo gci; 2980 struct pmc_classinfo *pci; 2981 struct pmc_classdep *pcd; 2982 int cl; 2983 2984 gci.pm_cputype = md->pmd_cputype; 2985 gci.pm_ncpu = pmc_cpu_max(); 2986 gci.pm_npmc = md->pmd_npmc; 2987 gci.pm_nclass = md->pmd_nclass; 2988 pci = gci.pm_classes; 2989 pcd = md->pmd_classdep; 2990 for (cl = 0; cl < md->pmd_nclass; cl++, pci++, pcd++) { 2991 pci->pm_caps = pcd->pcd_caps; 2992 pci->pm_class = pcd->pcd_class; 2993 pci->pm_width = pcd->pcd_width; 2994 pci->pm_num = pcd->pcd_num; 2995 } 2996 error = copyout(&gci, arg, sizeof(gci)); 2997 } 2998 break; 2999 3000 /* 3001 * Retrieve soft events list. 3002 */ 3003 case PMC_OP_GETDYNEVENTINFO: 3004 { 3005 enum pmc_class cl; 3006 enum pmc_event ev; 3007 struct pmc_op_getdyneventinfo *gei; 3008 struct pmc_dyn_event_descr dev; 3009 struct pmc_soft *ps; 3010 uint32_t nevent; 3011 3012 sx_assert(&pmc_sx, SX_LOCKED); 3013 3014 gei = (struct pmc_op_getdyneventinfo *) arg; 3015 3016 if ((error = copyin(&gei->pm_class, &cl, sizeof(cl))) != 0) 3017 break; 3018 3019 /* Only SOFT class is dynamic. */ 3020 if (cl != PMC_CLASS_SOFT) { 3021 error = EINVAL; 3022 break; 3023 } 3024 3025 nevent = 0; 3026 for (ev = PMC_EV_SOFT_FIRST; (int)ev <= PMC_EV_SOFT_LAST; ev++) { 3027 ps = pmc_soft_ev_acquire(ev); 3028 if (ps == NULL) 3029 continue; 3030 bcopy(&ps->ps_ev, &dev, sizeof(dev)); 3031 pmc_soft_ev_release(ps); 3032 3033 error = copyout(&dev, 3034 &gei->pm_events[nevent], 3035 sizeof(struct pmc_dyn_event_descr)); 3036 if (error != 0) 3037 break; 3038 nevent++; 3039 } 3040 if (error != 0) 3041 break; 3042 3043 error = copyout(&nevent, &gei->pm_nevent, 3044 sizeof(nevent)); 3045 } 3046 break; 3047 3048 /* 3049 * Get module statistics 3050 */ 3051 3052 case PMC_OP_GETDRIVERSTATS: 3053 { 3054 struct pmc_op_getdriverstats gms; 3055 3056 bcopy(&pmc_stats, &gms, sizeof(gms)); 3057 error = copyout(&gms, arg, sizeof(gms)); 3058 } 3059 break; 3060 3061 3062 /* 3063 * Retrieve module version number 3064 */ 3065 3066 case PMC_OP_GETMODULEVERSION: 3067 { 3068 uint32_t cv, modv; 3069 3070 /* retrieve the client's idea of the ABI version */ 3071 if ((error = copyin(arg, &cv, sizeof(uint32_t))) != 0) 3072 break; 3073 /* don't service clients newer than our driver */ 3074 modv = PMC_VERSION; 3075 if ((cv & 0xFFFF0000) > (modv & 0xFFFF0000)) { 3076 error = EPROGMISMATCH; 3077 break; 3078 } 3079 error = copyout(&modv, arg, sizeof(int)); 3080 } 3081 break; 3082 3083 3084 /* 3085 * Retrieve the state of all the PMCs on a given 3086 * CPU. 3087 */ 3088 3089 case PMC_OP_GETPMCINFO: 3090 { 3091 int ari; 3092 struct pmc *pm; 3093 size_t pmcinfo_size; 3094 uint32_t cpu, n, npmc; 3095 struct pmc_owner *po; 3096 struct pmc_binding pb; 3097 struct pmc_classdep *pcd; 3098 struct pmc_info *p, *pmcinfo; 3099 struct pmc_op_getpmcinfo *gpi; 3100 3101 PMC_DOWNGRADE_SX(); 3102 3103 gpi = (struct pmc_op_getpmcinfo *) arg; 3104 3105 if ((error = copyin(&gpi->pm_cpu, &cpu, sizeof(cpu))) != 0) 3106 break; 3107 3108 if (cpu >= pmc_cpu_max()) { 3109 error = EINVAL; 3110 break; 3111 } 3112 3113 if (!pmc_cpu_is_active(cpu)) { 3114 error = ENXIO; 3115 break; 3116 } 3117 3118 /* switch to CPU 'cpu' */ 3119 pmc_save_cpu_binding(&pb); 3120 pmc_select_cpu(cpu); 3121 3122 npmc = md->pmd_npmc; 3123 3124 pmcinfo_size = npmc * sizeof(struct pmc_info); 3125 pmcinfo = malloc(pmcinfo_size, M_PMC, M_WAITOK); 3126 3127 p = pmcinfo; 3128 3129 for (n = 0; n < md->pmd_npmc; n++, p++) { 3130 3131 pcd = pmc_ri_to_classdep(md, n, &ari); 3132 3133 KASSERT(pcd != NULL, 3134 ("[pmc,%d] null pcd ri=%d", __LINE__, n)); 3135 3136 if ((error = pcd->pcd_describe(cpu, ari, p, &pm)) != 0) 3137 break; 3138 3139 if (PMC_ROW_DISP_IS_STANDALONE(n)) 3140 p->pm_rowdisp = PMC_DISP_STANDALONE; 3141 else if (PMC_ROW_DISP_IS_THREAD(n)) 3142 p->pm_rowdisp = PMC_DISP_THREAD; 3143 else 3144 p->pm_rowdisp = PMC_DISP_FREE; 3145 3146 p->pm_ownerpid = -1; 3147 3148 if (pm == NULL) /* no PMC associated */ 3149 continue; 3150 3151 po = pm->pm_owner; 3152 3153 KASSERT(po->po_owner != NULL, 3154 ("[pmc,%d] pmc_owner had a null proc pointer", 3155 __LINE__)); 3156 3157 p->pm_ownerpid = po->po_owner->p_pid; 3158 p->pm_mode = PMC_TO_MODE(pm); 3159 p->pm_event = pm->pm_event; 3160 p->pm_flags = pm->pm_flags; 3161 3162 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 3163 p->pm_reloadcount = 3164 pm->pm_sc.pm_reloadcount; 3165 } 3166 3167 pmc_restore_cpu_binding(&pb); 3168 3169 /* now copy out the PMC info collected */ 3170 if (error == 0) 3171 error = copyout(pmcinfo, &gpi->pm_pmcs, pmcinfo_size); 3172 3173 free(pmcinfo, M_PMC); 3174 } 3175 break; 3176 3177 3178 /* 3179 * Set the administrative state of a PMC. I.e. whether 3180 * the PMC is to be used or not. 3181 */ 3182 3183 case PMC_OP_PMCADMIN: 3184 { 3185 int cpu, ri; 3186 enum pmc_state request; 3187 struct pmc_cpu *pc; 3188 struct pmc_hw *phw; 3189 struct pmc_op_pmcadmin pma; 3190 struct pmc_binding pb; 3191 3192 sx_assert(&pmc_sx, SX_XLOCKED); 3193 3194 KASSERT(td == curthread, 3195 ("[pmc,%d] td != curthread", __LINE__)); 3196 3197 error = priv_check(td, PRIV_PMC_MANAGE); 3198 if (error) 3199 break; 3200 3201 if ((error = copyin(arg, &pma, sizeof(pma))) != 0) 3202 break; 3203 3204 cpu = pma.pm_cpu; 3205 3206 if (cpu < 0 || cpu >= (int) pmc_cpu_max()) { 3207 error = EINVAL; 3208 break; 3209 } 3210 3211 if (!pmc_cpu_is_active(cpu)) { 3212 error = ENXIO; 3213 break; 3214 } 3215 3216 request = pma.pm_state; 3217 3218 if (request != PMC_STATE_DISABLED && 3219 request != PMC_STATE_FREE) { 3220 error = EINVAL; 3221 break; 3222 } 3223 3224 ri = pma.pm_pmc; /* pmc id == row index */ 3225 if (ri < 0 || ri >= (int) md->pmd_npmc) { 3226 error = EINVAL; 3227 break; 3228 } 3229 3230 /* 3231 * We can't disable a PMC with a row-index allocated 3232 * for process virtual PMCs. 3233 */ 3234 3235 if (PMC_ROW_DISP_IS_THREAD(ri) && 3236 request == PMC_STATE_DISABLED) { 3237 error = EBUSY; 3238 break; 3239 } 3240 3241 /* 3242 * otherwise, this PMC on this CPU is either free or 3243 * in system-wide mode. 3244 */ 3245 3246 pmc_save_cpu_binding(&pb); 3247 pmc_select_cpu(cpu); 3248 3249 pc = pmc_pcpu[cpu]; 3250 phw = pc->pc_hwpmcs[ri]; 3251 3252 /* 3253 * XXX do we need some kind of 'forced' disable? 3254 */ 3255 3256 if (phw->phw_pmc == NULL) { 3257 if (request == PMC_STATE_DISABLED && 3258 (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED)) { 3259 phw->phw_state &= ~PMC_PHW_FLAG_IS_ENABLED; 3260 PMC_MARK_ROW_STANDALONE(ri); 3261 } else if (request == PMC_STATE_FREE && 3262 (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0) { 3263 phw->phw_state |= PMC_PHW_FLAG_IS_ENABLED; 3264 PMC_UNMARK_ROW_STANDALONE(ri); 3265 } 3266 /* other cases are a no-op */ 3267 } else 3268 error = EBUSY; 3269 3270 pmc_restore_cpu_binding(&pb); 3271 } 3272 break; 3273 3274 3275 /* 3276 * Allocate a PMC. 3277 */ 3278 3279 case PMC_OP_PMCALLOCATE: 3280 { 3281 int adjri, n; 3282 u_int cpu; 3283 uint32_t caps; 3284 struct pmc *pmc; 3285 enum pmc_mode mode; 3286 struct pmc_hw *phw; 3287 struct pmc_binding pb; 3288 struct pmc_classdep *pcd; 3289 struct pmc_op_pmcallocate pa; 3290 3291 if ((error = copyin(arg, &pa, sizeof(pa))) != 0) 3292 break; 3293 3294 caps = pa.pm_caps; 3295 mode = pa.pm_mode; 3296 cpu = pa.pm_cpu; 3297 3298 if ((mode != PMC_MODE_SS && mode != PMC_MODE_SC && 3299 mode != PMC_MODE_TS && mode != PMC_MODE_TC) || 3300 (cpu != (u_int) PMC_CPU_ANY && cpu >= pmc_cpu_max())) { 3301 error = EINVAL; 3302 break; 3303 } 3304 3305 /* 3306 * Virtual PMCs should only ask for a default CPU. 3307 * System mode PMCs need to specify a non-default CPU. 3308 */ 3309 3310 if ((PMC_IS_VIRTUAL_MODE(mode) && cpu != (u_int) PMC_CPU_ANY) || 3311 (PMC_IS_SYSTEM_MODE(mode) && cpu == (u_int) PMC_CPU_ANY)) { 3312 error = EINVAL; 3313 break; 3314 } 3315 3316 /* 3317 * Check that an inactive CPU is not being asked for. 3318 */ 3319 3320 if (PMC_IS_SYSTEM_MODE(mode) && !pmc_cpu_is_active(cpu)) { 3321 error = ENXIO; 3322 break; 3323 } 3324 3325 /* 3326 * Refuse an allocation for a system-wide PMC if this 3327 * process has been jailed, or if this process lacks 3328 * super-user credentials and the sysctl tunable 3329 * 'security.bsd.unprivileged_syspmcs' is zero. 3330 */ 3331 3332 if (PMC_IS_SYSTEM_MODE(mode)) { 3333 if (jailed(curthread->td_ucred)) { 3334 error = EPERM; 3335 break; 3336 } 3337 if (!pmc_unprivileged_syspmcs) { 3338 error = priv_check(curthread, 3339 PRIV_PMC_SYSTEM); 3340 if (error) 3341 break; 3342 } 3343 } 3344 3345 /* 3346 * Look for valid values for 'pm_flags' 3347 */ 3348 3349 if ((pa.pm_flags & ~(PMC_F_DESCENDANTS | PMC_F_LOG_PROCCSW | 3350 PMC_F_LOG_PROCEXIT | PMC_F_CALLCHAIN)) != 0) { 3351 error = EINVAL; 3352 break; 3353 } 3354 3355 /* process logging options are not allowed for system PMCs */ 3356 if (PMC_IS_SYSTEM_MODE(mode) && (pa.pm_flags & 3357 (PMC_F_LOG_PROCCSW | PMC_F_LOG_PROCEXIT))) { 3358 error = EINVAL; 3359 break; 3360 } 3361 3362 /* 3363 * All sampling mode PMCs need to be able to interrupt the 3364 * CPU. 3365 */ 3366 if (PMC_IS_SAMPLING_MODE(mode)) 3367 caps |= PMC_CAP_INTERRUPT; 3368 3369 /* A valid class specifier should have been passed in. */ 3370 for (n = 0; n < md->pmd_nclass; n++) 3371 if (md->pmd_classdep[n].pcd_class == pa.pm_class) 3372 break; 3373 if (n == md->pmd_nclass) { 3374 error = EINVAL; 3375 break; 3376 } 3377 3378 /* The requested PMC capabilities should be feasible. */ 3379 if ((md->pmd_classdep[n].pcd_caps & caps) != caps) { 3380 error = EOPNOTSUPP; 3381 break; 3382 } 3383 3384 PMCDBG(PMC,ALL,2, "event=%d caps=0x%x mode=%d cpu=%d", 3385 pa.pm_ev, caps, mode, cpu); 3386 3387 pmc = pmc_allocate_pmc_descriptor(); 3388 pmc->pm_id = PMC_ID_MAKE_ID(cpu,pa.pm_mode,pa.pm_class, 3389 PMC_ID_INVALID); 3390 pmc->pm_event = pa.pm_ev; 3391 pmc->pm_state = PMC_STATE_FREE; 3392 pmc->pm_caps = caps; 3393 pmc->pm_flags = pa.pm_flags; 3394 3395 /* switch thread to CPU 'cpu' */ 3396 pmc_save_cpu_binding(&pb); 3397 3398 #define PMC_IS_SHAREABLE_PMC(cpu, n) \ 3399 (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_state & \ 3400 PMC_PHW_FLAG_IS_SHAREABLE) 3401 #define PMC_IS_UNALLOCATED(cpu, n) \ 3402 (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_pmc == NULL) 3403 3404 if (PMC_IS_SYSTEM_MODE(mode)) { 3405 pmc_select_cpu(cpu); 3406 for (n = 0; n < (int) md->pmd_npmc; n++) { 3407 pcd = pmc_ri_to_classdep(md, n, &adjri); 3408 if (pmc_can_allocate_row(n, mode) == 0 && 3409 pmc_can_allocate_rowindex( 3410 curthread->td_proc, n, cpu) == 0 && 3411 (PMC_IS_UNALLOCATED(cpu, n) || 3412 PMC_IS_SHAREABLE_PMC(cpu, n)) && 3413 pcd->pcd_allocate_pmc(cpu, adjri, pmc, 3414 &pa) == 0) 3415 break; 3416 } 3417 } else { 3418 /* Process virtual mode */ 3419 for (n = 0; n < (int) md->pmd_npmc; n++) { 3420 pcd = pmc_ri_to_classdep(md, n, &adjri); 3421 if (pmc_can_allocate_row(n, mode) == 0 && 3422 pmc_can_allocate_rowindex( 3423 curthread->td_proc, n, 3424 PMC_CPU_ANY) == 0 && 3425 pcd->pcd_allocate_pmc(curthread->td_oncpu, 3426 adjri, pmc, &pa) == 0) 3427 break; 3428 } 3429 } 3430 3431 #undef PMC_IS_UNALLOCATED 3432 #undef PMC_IS_SHAREABLE_PMC 3433 3434 pmc_restore_cpu_binding(&pb); 3435 3436 if (n == (int) md->pmd_npmc) { 3437 pmc_destroy_pmc_descriptor(pmc); 3438 free(pmc, M_PMC); 3439 pmc = NULL; 3440 error = EINVAL; 3441 break; 3442 } 3443 3444 /* Fill in the correct value in the ID field */ 3445 pmc->pm_id = PMC_ID_MAKE_ID(cpu,mode,pa.pm_class,n); 3446 3447 PMCDBG(PMC,ALL,2, "ev=%d class=%d mode=%d n=%d -> pmcid=%x", 3448 pmc->pm_event, pa.pm_class, mode, n, pmc->pm_id); 3449 3450 /* Process mode PMCs with logging enabled need log files */ 3451 if (pmc->pm_flags & (PMC_F_LOG_PROCEXIT | PMC_F_LOG_PROCCSW)) 3452 pmc->pm_flags |= PMC_F_NEEDS_LOGFILE; 3453 3454 /* All system mode sampling PMCs require a log file */ 3455 if (PMC_IS_SAMPLING_MODE(mode) && PMC_IS_SYSTEM_MODE(mode)) 3456 pmc->pm_flags |= PMC_F_NEEDS_LOGFILE; 3457 3458 /* 3459 * Configure global pmc's immediately 3460 */ 3461 3462 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pmc))) { 3463 3464 pmc_save_cpu_binding(&pb); 3465 pmc_select_cpu(cpu); 3466 3467 phw = pmc_pcpu[cpu]->pc_hwpmcs[n]; 3468 pcd = pmc_ri_to_classdep(md, n, &adjri); 3469 3470 if ((phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0 || 3471 (error = pcd->pcd_config_pmc(cpu, adjri, pmc)) != 0) { 3472 (void) pcd->pcd_release_pmc(cpu, adjri, pmc); 3473 pmc_destroy_pmc_descriptor(pmc); 3474 free(pmc, M_PMC); 3475 pmc = NULL; 3476 pmc_restore_cpu_binding(&pb); 3477 error = EPERM; 3478 break; 3479 } 3480 3481 pmc_restore_cpu_binding(&pb); 3482 } 3483 3484 pmc->pm_state = PMC_STATE_ALLOCATED; 3485 3486 /* 3487 * mark row disposition 3488 */ 3489 3490 if (PMC_IS_SYSTEM_MODE(mode)) 3491 PMC_MARK_ROW_STANDALONE(n); 3492 else 3493 PMC_MARK_ROW_THREAD(n); 3494 3495 /* 3496 * Register this PMC with the current thread as its owner. 3497 */ 3498 3499 if ((error = 3500 pmc_register_owner(curthread->td_proc, pmc)) != 0) { 3501 pmc_release_pmc_descriptor(pmc); 3502 free(pmc, M_PMC); 3503 pmc = NULL; 3504 break; 3505 } 3506 3507 /* 3508 * Return the allocated index. 3509 */ 3510 3511 pa.pm_pmcid = pmc->pm_id; 3512 3513 error = copyout(&pa, arg, sizeof(pa)); 3514 } 3515 break; 3516 3517 3518 /* 3519 * Attach a PMC to a process. 3520 */ 3521 3522 case PMC_OP_PMCATTACH: 3523 { 3524 struct pmc *pm; 3525 struct proc *p; 3526 struct pmc_op_pmcattach a; 3527 3528 sx_assert(&pmc_sx, SX_XLOCKED); 3529 3530 if ((error = copyin(arg, &a, sizeof(a))) != 0) 3531 break; 3532 3533 if (a.pm_pid < 0) { 3534 error = EINVAL; 3535 break; 3536 } else if (a.pm_pid == 0) 3537 a.pm_pid = td->td_proc->p_pid; 3538 3539 if ((error = pmc_find_pmc(a.pm_pmc, &pm)) != 0) 3540 break; 3541 3542 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) { 3543 error = EINVAL; 3544 break; 3545 } 3546 3547 /* PMCs may be (re)attached only when allocated or stopped */ 3548 if (pm->pm_state == PMC_STATE_RUNNING) { 3549 error = EBUSY; 3550 break; 3551 } else if (pm->pm_state != PMC_STATE_ALLOCATED && 3552 pm->pm_state != PMC_STATE_STOPPED) { 3553 error = EINVAL; 3554 break; 3555 } 3556 3557 /* lookup pid */ 3558 if ((p = pfind(a.pm_pid)) == NULL) { 3559 error = ESRCH; 3560 break; 3561 } 3562 3563 /* 3564 * Ignore processes that are working on exiting. 3565 */ 3566 if (p->p_flag & P_WEXIT) { 3567 error = ESRCH; 3568 PROC_UNLOCK(p); /* pfind() returns a locked process */ 3569 break; 3570 } 3571 3572 /* 3573 * we are allowed to attach a PMC to a process if 3574 * we can debug it. 3575 */ 3576 error = p_candebug(curthread, p); 3577 3578 PROC_UNLOCK(p); 3579 3580 if (error == 0) 3581 error = pmc_attach_process(p, pm); 3582 } 3583 break; 3584 3585 3586 /* 3587 * Detach an attached PMC from a process. 3588 */ 3589 3590 case PMC_OP_PMCDETACH: 3591 { 3592 struct pmc *pm; 3593 struct proc *p; 3594 struct pmc_op_pmcattach a; 3595 3596 if ((error = copyin(arg, &a, sizeof(a))) != 0) 3597 break; 3598 3599 if (a.pm_pid < 0) { 3600 error = EINVAL; 3601 break; 3602 } else if (a.pm_pid == 0) 3603 a.pm_pid = td->td_proc->p_pid; 3604 3605 if ((error = pmc_find_pmc(a.pm_pmc, &pm)) != 0) 3606 break; 3607 3608 if ((p = pfind(a.pm_pid)) == NULL) { 3609 error = ESRCH; 3610 break; 3611 } 3612 3613 /* 3614 * Treat processes that are in the process of exiting 3615 * as if they were not present. 3616 */ 3617 3618 if (p->p_flag & P_WEXIT) 3619 error = ESRCH; 3620 3621 PROC_UNLOCK(p); /* pfind() returns a locked process */ 3622 3623 if (error == 0) 3624 error = pmc_detach_process(p, pm); 3625 } 3626 break; 3627 3628 3629 /* 3630 * Retrieve the MSR number associated with the counter 3631 * 'pmc_id'. This allows processes to directly use RDPMC 3632 * instructions to read their PMCs, without the overhead of a 3633 * system call. 3634 */ 3635 3636 case PMC_OP_PMCGETMSR: 3637 { 3638 int adjri, ri; 3639 struct pmc *pm; 3640 struct pmc_target *pt; 3641 struct pmc_op_getmsr gm; 3642 struct pmc_classdep *pcd; 3643 3644 PMC_DOWNGRADE_SX(); 3645 3646 if ((error = copyin(arg, &gm, sizeof(gm))) != 0) 3647 break; 3648 3649 if ((error = pmc_find_pmc(gm.pm_pmcid, &pm)) != 0) 3650 break; 3651 3652 /* 3653 * The allocated PMC has to be a process virtual PMC, 3654 * i.e., of type MODE_T[CS]. Global PMCs can only be 3655 * read using the PMCREAD operation since they may be 3656 * allocated on a different CPU than the one we could 3657 * be running on at the time of the RDPMC instruction. 3658 * 3659 * The GETMSR operation is not allowed for PMCs that 3660 * are inherited across processes. 3661 */ 3662 3663 if (!PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)) || 3664 (pm->pm_flags & PMC_F_DESCENDANTS)) { 3665 error = EINVAL; 3666 break; 3667 } 3668 3669 /* 3670 * It only makes sense to use a RDPMC (or its 3671 * equivalent instruction on non-x86 architectures) on 3672 * a process that has allocated and attached a PMC to 3673 * itself. Conversely the PMC is only allowed to have 3674 * one process attached to it -- its owner. 3675 */ 3676 3677 if ((pt = LIST_FIRST(&pm->pm_targets)) == NULL || 3678 LIST_NEXT(pt, pt_next) != NULL || 3679 pt->pt_process->pp_proc != pm->pm_owner->po_owner) { 3680 error = EINVAL; 3681 break; 3682 } 3683 3684 ri = PMC_TO_ROWINDEX(pm); 3685 pcd = pmc_ri_to_classdep(md, ri, &adjri); 3686 3687 /* PMC class has no 'GETMSR' support */ 3688 if (pcd->pcd_get_msr == NULL) { 3689 error = ENOSYS; 3690 break; 3691 } 3692 3693 if ((error = (*pcd->pcd_get_msr)(adjri, &gm.pm_msr)) < 0) 3694 break; 3695 3696 if ((error = copyout(&gm, arg, sizeof(gm))) < 0) 3697 break; 3698 3699 /* 3700 * Mark our process as using MSRs. Update machine 3701 * state using a forced context switch. 3702 */ 3703 3704 pt->pt_process->pp_flags |= PMC_PP_ENABLE_MSR_ACCESS; 3705 pmc_force_context_switch(); 3706 3707 } 3708 break; 3709 3710 /* 3711 * Release an allocated PMC 3712 */ 3713 3714 case PMC_OP_PMCRELEASE: 3715 { 3716 pmc_id_t pmcid; 3717 struct pmc *pm; 3718 struct pmc_owner *po; 3719 struct pmc_op_simple sp; 3720 3721 /* 3722 * Find PMC pointer for the named PMC. 3723 * 3724 * Use pmc_release_pmc_descriptor() to switch off the 3725 * PMC, remove all its target threads, and remove the 3726 * PMC from its owner's list. 3727 * 3728 * Remove the owner record if this is the last PMC 3729 * owned. 3730 * 3731 * Free up space. 3732 */ 3733 3734 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 3735 break; 3736 3737 pmcid = sp.pm_pmcid; 3738 3739 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 3740 break; 3741 3742 po = pm->pm_owner; 3743 pmc_release_pmc_descriptor(pm); 3744 pmc_maybe_remove_owner(po); 3745 3746 free(pm, M_PMC); 3747 } 3748 break; 3749 3750 3751 /* 3752 * Read and/or write a PMC. 3753 */ 3754 3755 case PMC_OP_PMCRW: 3756 { 3757 int adjri; 3758 struct pmc *pm; 3759 uint32_t cpu, ri; 3760 pmc_value_t oldvalue; 3761 struct pmc_binding pb; 3762 struct pmc_op_pmcrw prw; 3763 struct pmc_classdep *pcd; 3764 struct pmc_op_pmcrw *pprw; 3765 3766 PMC_DOWNGRADE_SX(); 3767 3768 if ((error = copyin(arg, &prw, sizeof(prw))) != 0) 3769 break; 3770 3771 ri = 0; 3772 PMCDBG(PMC,OPS,1, "rw id=%d flags=0x%x", prw.pm_pmcid, 3773 prw.pm_flags); 3774 3775 /* must have at least one flag set */ 3776 if ((prw.pm_flags & (PMC_F_OLDVALUE|PMC_F_NEWVALUE)) == 0) { 3777 error = EINVAL; 3778 break; 3779 } 3780 3781 /* locate pmc descriptor */ 3782 if ((error = pmc_find_pmc(prw.pm_pmcid, &pm)) != 0) 3783 break; 3784 3785 /* Can't read a PMC that hasn't been started. */ 3786 if (pm->pm_state != PMC_STATE_ALLOCATED && 3787 pm->pm_state != PMC_STATE_STOPPED && 3788 pm->pm_state != PMC_STATE_RUNNING) { 3789 error = EINVAL; 3790 break; 3791 } 3792 3793 /* writing a new value is allowed only for 'STOPPED' pmcs */ 3794 if (pm->pm_state == PMC_STATE_RUNNING && 3795 (prw.pm_flags & PMC_F_NEWVALUE)) { 3796 error = EBUSY; 3797 break; 3798 } 3799 3800 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) { 3801 3802 /* 3803 * If this PMC is attached to its owner (i.e., 3804 * the process requesting this operation) and 3805 * is running, then attempt to get an 3806 * upto-date reading from hardware for a READ. 3807 * Writes are only allowed when the PMC is 3808 * stopped, so only update the saved value 3809 * field. 3810 * 3811 * If the PMC is not running, or is not 3812 * attached to its owner, read/write to the 3813 * savedvalue field. 3814 */ 3815 3816 ri = PMC_TO_ROWINDEX(pm); 3817 pcd = pmc_ri_to_classdep(md, ri, &adjri); 3818 3819 mtx_pool_lock_spin(pmc_mtxpool, pm); 3820 cpu = curthread->td_oncpu; 3821 3822 if (prw.pm_flags & PMC_F_OLDVALUE) { 3823 if ((pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) && 3824 (pm->pm_state == PMC_STATE_RUNNING)) 3825 error = (*pcd->pcd_read_pmc)(cpu, adjri, 3826 &oldvalue); 3827 else 3828 oldvalue = pm->pm_gv.pm_savedvalue; 3829 } 3830 if (prw.pm_flags & PMC_F_NEWVALUE) 3831 pm->pm_gv.pm_savedvalue = prw.pm_value; 3832 3833 mtx_pool_unlock_spin(pmc_mtxpool, pm); 3834 3835 } else { /* System mode PMCs */ 3836 cpu = PMC_TO_CPU(pm); 3837 ri = PMC_TO_ROWINDEX(pm); 3838 pcd = pmc_ri_to_classdep(md, ri, &adjri); 3839 3840 if (!pmc_cpu_is_active(cpu)) { 3841 error = ENXIO; 3842 break; 3843 } 3844 3845 /* move this thread to CPU 'cpu' */ 3846 pmc_save_cpu_binding(&pb); 3847 pmc_select_cpu(cpu); 3848 3849 critical_enter(); 3850 /* save old value */ 3851 if (prw.pm_flags & PMC_F_OLDVALUE) 3852 if ((error = (*pcd->pcd_read_pmc)(cpu, adjri, 3853 &oldvalue))) 3854 goto error; 3855 /* write out new value */ 3856 if (prw.pm_flags & PMC_F_NEWVALUE) 3857 error = (*pcd->pcd_write_pmc)(cpu, adjri, 3858 prw.pm_value); 3859 error: 3860 critical_exit(); 3861 pmc_restore_cpu_binding(&pb); 3862 if (error) 3863 break; 3864 } 3865 3866 pprw = (struct pmc_op_pmcrw *) arg; 3867 3868 #ifdef DEBUG 3869 if (prw.pm_flags & PMC_F_NEWVALUE) 3870 PMCDBG(PMC,OPS,2, "rw id=%d new %jx -> old %jx", 3871 ri, prw.pm_value, oldvalue); 3872 else if (prw.pm_flags & PMC_F_OLDVALUE) 3873 PMCDBG(PMC,OPS,2, "rw id=%d -> old %jx", ri, oldvalue); 3874 #endif 3875 3876 /* return old value if requested */ 3877 if (prw.pm_flags & PMC_F_OLDVALUE) 3878 if ((error = copyout(&oldvalue, &pprw->pm_value, 3879 sizeof(prw.pm_value)))) 3880 break; 3881 3882 } 3883 break; 3884 3885 3886 /* 3887 * Set the sampling rate for a sampling mode PMC and the 3888 * initial count for a counting mode PMC. 3889 */ 3890 3891 case PMC_OP_PMCSETCOUNT: 3892 { 3893 struct pmc *pm; 3894 struct pmc_op_pmcsetcount sc; 3895 3896 PMC_DOWNGRADE_SX(); 3897 3898 if ((error = copyin(arg, &sc, sizeof(sc))) != 0) 3899 break; 3900 3901 if ((error = pmc_find_pmc(sc.pm_pmcid, &pm)) != 0) 3902 break; 3903 3904 if (pm->pm_state == PMC_STATE_RUNNING) { 3905 error = EBUSY; 3906 break; 3907 } 3908 3909 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 3910 pm->pm_sc.pm_reloadcount = sc.pm_count; 3911 else 3912 pm->pm_sc.pm_initial = sc.pm_count; 3913 } 3914 break; 3915 3916 3917 /* 3918 * Start a PMC. 3919 */ 3920 3921 case PMC_OP_PMCSTART: 3922 { 3923 pmc_id_t pmcid; 3924 struct pmc *pm; 3925 struct pmc_op_simple sp; 3926 3927 sx_assert(&pmc_sx, SX_XLOCKED); 3928 3929 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 3930 break; 3931 3932 pmcid = sp.pm_pmcid; 3933 3934 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 3935 break; 3936 3937 KASSERT(pmcid == pm->pm_id, 3938 ("[pmc,%d] pmcid %x != id %x", __LINE__, 3939 pm->pm_id, pmcid)); 3940 3941 if (pm->pm_state == PMC_STATE_RUNNING) /* already running */ 3942 break; 3943 else if (pm->pm_state != PMC_STATE_STOPPED && 3944 pm->pm_state != PMC_STATE_ALLOCATED) { 3945 error = EINVAL; 3946 break; 3947 } 3948 3949 error = pmc_start(pm); 3950 } 3951 break; 3952 3953 3954 /* 3955 * Stop a PMC. 3956 */ 3957 3958 case PMC_OP_PMCSTOP: 3959 { 3960 pmc_id_t pmcid; 3961 struct pmc *pm; 3962 struct pmc_op_simple sp; 3963 3964 PMC_DOWNGRADE_SX(); 3965 3966 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 3967 break; 3968 3969 pmcid = sp.pm_pmcid; 3970 3971 /* 3972 * Mark the PMC as inactive and invoke the MD stop 3973 * routines if needed. 3974 */ 3975 3976 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 3977 break; 3978 3979 KASSERT(pmcid == pm->pm_id, 3980 ("[pmc,%d] pmc id %x != pmcid %x", __LINE__, 3981 pm->pm_id, pmcid)); 3982 3983 if (pm->pm_state == PMC_STATE_STOPPED) /* already stopped */ 3984 break; 3985 else if (pm->pm_state != PMC_STATE_RUNNING) { 3986 error = EINVAL; 3987 break; 3988 } 3989 3990 error = pmc_stop(pm); 3991 } 3992 break; 3993 3994 3995 /* 3996 * Write a user supplied value to the log file. 3997 */ 3998 3999 case PMC_OP_WRITELOG: 4000 { 4001 struct pmc_op_writelog wl; 4002 struct pmc_owner *po; 4003 4004 PMC_DOWNGRADE_SX(); 4005 4006 if ((error = copyin(arg, &wl, sizeof(wl))) != 0) 4007 break; 4008 4009 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 4010 error = EINVAL; 4011 break; 4012 } 4013 4014 if ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) { 4015 error = EINVAL; 4016 break; 4017 } 4018 4019 error = pmclog_process_userlog(po, &wl); 4020 } 4021 break; 4022 4023 4024 default: 4025 error = EINVAL; 4026 break; 4027 } 4028 4029 if (is_sx_locked != 0) { 4030 if (is_sx_downgraded) 4031 sx_sunlock(&pmc_sx); 4032 else 4033 sx_xunlock(&pmc_sx); 4034 } 4035 4036 if (error) 4037 atomic_add_int(&pmc_stats.pm_syscall_errors, 1); 4038 4039 PICKUP_GIANT(); 4040 4041 return error; 4042 } 4043 4044 /* 4045 * Helper functions 4046 */ 4047 4048 4049 /* 4050 * Mark the thread as needing callchain capture and post an AST. The 4051 * actual callchain capture will be done in a context where it is safe 4052 * to take page faults. 4053 */ 4054 4055 static void 4056 pmc_post_callchain_callback(void) 4057 { 4058 struct thread *td; 4059 4060 td = curthread; 4061 4062 /* 4063 * If there is multiple PMCs for the same interrupt ignore new post 4064 */ 4065 if (td->td_pflags & TDP_CALLCHAIN) 4066 return; 4067 4068 /* 4069 * Mark this thread as needing callchain capture. 4070 * `td->td_pflags' will be safe to touch because this thread 4071 * was in user space when it was interrupted. 4072 */ 4073 td->td_pflags |= TDP_CALLCHAIN; 4074 4075 /* 4076 * Don't let this thread migrate between CPUs until callchain 4077 * capture completes. 4078 */ 4079 sched_pin(); 4080 4081 return; 4082 } 4083 4084 /* 4085 * Interrupt processing. 4086 * 4087 * Find a free slot in the per-cpu array of samples and capture the 4088 * current callchain there. If a sample was successfully added, a bit 4089 * is set in mask 'pmc_cpumask' denoting that the DO_SAMPLES hook 4090 * needs to be invoked from the clock handler. 4091 * 4092 * This function is meant to be called from an NMI handler. It cannot 4093 * use any of the locking primitives supplied by the OS. 4094 */ 4095 4096 int 4097 pmc_process_interrupt(int cpu, int ring, struct pmc *pm, struct trapframe *tf, 4098 int inuserspace) 4099 { 4100 int error, callchaindepth; 4101 struct thread *td; 4102 struct pmc_sample *ps; 4103 struct pmc_samplebuffer *psb; 4104 4105 error = 0; 4106 4107 /* 4108 * Allocate space for a sample buffer. 4109 */ 4110 psb = pmc_pcpu[cpu]->pc_sb[ring]; 4111 4112 ps = psb->ps_write; 4113 if (ps->ps_nsamples) { /* in use, reader hasn't caught up */ 4114 pm->pm_stalled = 1; 4115 atomic_add_int(&pmc_stats.pm_intr_bufferfull, 1); 4116 PMCDBG(SAM,INT,1,"(spc) cpu=%d pm=%p tf=%p um=%d wr=%d rd=%d", 4117 cpu, pm, (void *) tf, inuserspace, 4118 (int) (psb->ps_write - psb->ps_samples), 4119 (int) (psb->ps_read - psb->ps_samples)); 4120 error = ENOMEM; 4121 goto done; 4122 } 4123 4124 4125 /* Fill in entry. */ 4126 PMCDBG(SAM,INT,1,"cpu=%d pm=%p tf=%p um=%d wr=%d rd=%d", cpu, pm, 4127 (void *) tf, inuserspace, 4128 (int) (psb->ps_write - psb->ps_samples), 4129 (int) (psb->ps_read - psb->ps_samples)); 4130 4131 KASSERT(pm->pm_runcount >= 0, 4132 ("[pmc,%d] pm=%p runcount %d", __LINE__, (void *) pm, 4133 pm->pm_runcount)); 4134 4135 atomic_add_rel_int(&pm->pm_runcount, 1); /* hold onto PMC */ 4136 4137 ps->ps_pmc = pm; 4138 if ((td = curthread) && td->td_proc) 4139 ps->ps_pid = td->td_proc->p_pid; 4140 else 4141 ps->ps_pid = -1; 4142 ps->ps_cpu = cpu; 4143 ps->ps_td = td; 4144 ps->ps_flags = inuserspace ? PMC_CC_F_USERSPACE : 0; 4145 4146 callchaindepth = (pm->pm_flags & PMC_F_CALLCHAIN) ? 4147 pmc_callchaindepth : 1; 4148 4149 if (callchaindepth == 1) 4150 ps->ps_pc[0] = PMC_TRAPFRAME_TO_PC(tf); 4151 else { 4152 /* 4153 * Kernel stack traversals can be done immediately, 4154 * while we defer to an AST for user space traversals. 4155 */ 4156 if (!inuserspace) { 4157 callchaindepth = 4158 pmc_save_kernel_callchain(ps->ps_pc, 4159 callchaindepth, tf); 4160 } else { 4161 pmc_post_callchain_callback(); 4162 callchaindepth = PMC_SAMPLE_INUSE; 4163 } 4164 } 4165 4166 ps->ps_nsamples = callchaindepth; /* mark entry as in use */ 4167 4168 /* increment write pointer, modulo ring buffer size */ 4169 ps++; 4170 if (ps == psb->ps_fence) 4171 psb->ps_write = psb->ps_samples; 4172 else 4173 psb->ps_write = ps; 4174 4175 done: 4176 /* mark CPU as needing processing */ 4177 CPU_SET_ATOMIC(cpu, &pmc_cpumask); 4178 4179 return (error); 4180 } 4181 4182 /* 4183 * Capture a user call chain. This function will be called from ast() 4184 * before control returns to userland and before the process gets 4185 * rescheduled. 4186 */ 4187 4188 static void 4189 pmc_capture_user_callchain(int cpu, int ring, struct trapframe *tf) 4190 { 4191 int i; 4192 struct pmc *pm; 4193 struct thread *td; 4194 struct pmc_sample *ps; 4195 struct pmc_samplebuffer *psb; 4196 #ifdef INVARIANTS 4197 int ncallchains; 4198 #endif 4199 4200 psb = pmc_pcpu[cpu]->pc_sb[ring]; 4201 td = curthread; 4202 4203 KASSERT(td->td_pflags & TDP_CALLCHAIN, 4204 ("[pmc,%d] Retrieving callchain for thread that doesn't want it", 4205 __LINE__)); 4206 4207 #ifdef INVARIANTS 4208 ncallchains = 0; 4209 #endif 4210 4211 /* 4212 * Iterate through all deferred callchain requests. 4213 */ 4214 4215 ps = psb->ps_samples; 4216 for (i = 0; i < pmc_nsamples; i++, ps++) { 4217 4218 if (ps->ps_nsamples != PMC_SAMPLE_INUSE) 4219 continue; 4220 if (ps->ps_td != td) 4221 continue; 4222 4223 KASSERT(ps->ps_cpu == cpu, 4224 ("[pmc,%d] cpu mismatch ps_cpu=%d pcpu=%d", __LINE__, 4225 ps->ps_cpu, PCPU_GET(cpuid))); 4226 4227 pm = ps->ps_pmc; 4228 4229 KASSERT(pm->pm_flags & PMC_F_CALLCHAIN, 4230 ("[pmc,%d] Retrieving callchain for PMC that doesn't " 4231 "want it", __LINE__)); 4232 4233 KASSERT(pm->pm_runcount > 0, 4234 ("[pmc,%d] runcount %d", __LINE__, pm->pm_runcount)); 4235 4236 /* 4237 * Retrieve the callchain and mark the sample buffer 4238 * as 'processable' by the timer tick sweep code. 4239 */ 4240 ps->ps_nsamples = pmc_save_user_callchain(ps->ps_pc, 4241 pmc_callchaindepth, tf); 4242 4243 #ifdef INVARIANTS 4244 ncallchains++; 4245 #endif 4246 } 4247 4248 KASSERT(ncallchains > 0, 4249 ("[pmc,%d] cpu %d didn't find a sample to collect", __LINE__, 4250 cpu)); 4251 4252 KASSERT(td->td_pinned == 1, 4253 ("[pmc,%d] invalid td_pinned value", __LINE__)); 4254 sched_unpin(); /* Can migrate safely now. */ 4255 4256 return; 4257 } 4258 4259 /* 4260 * Process saved PC samples. 4261 */ 4262 4263 static void 4264 pmc_process_samples(int cpu, int ring) 4265 { 4266 struct pmc *pm; 4267 int adjri, n; 4268 struct thread *td; 4269 struct pmc_owner *po; 4270 struct pmc_sample *ps; 4271 struct pmc_classdep *pcd; 4272 struct pmc_samplebuffer *psb; 4273 4274 KASSERT(PCPU_GET(cpuid) == cpu, 4275 ("[pmc,%d] not on the correct CPU pcpu=%d cpu=%d", __LINE__, 4276 PCPU_GET(cpuid), cpu)); 4277 4278 psb = pmc_pcpu[cpu]->pc_sb[ring]; 4279 4280 for (n = 0; n < pmc_nsamples; n++) { /* bound on #iterations */ 4281 4282 ps = psb->ps_read; 4283 if (ps->ps_nsamples == PMC_SAMPLE_FREE) 4284 break; 4285 4286 pm = ps->ps_pmc; 4287 4288 KASSERT(pm->pm_runcount > 0, 4289 ("[pmc,%d] pm=%p runcount %d", __LINE__, (void *) pm, 4290 pm->pm_runcount)); 4291 4292 po = pm->pm_owner; 4293 4294 KASSERT(PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)), 4295 ("[pmc,%d] pmc=%p non-sampling mode=%d", __LINE__, 4296 pm, PMC_TO_MODE(pm))); 4297 4298 /* Ignore PMCs that have been switched off */ 4299 if (pm->pm_state != PMC_STATE_RUNNING) 4300 goto entrydone; 4301 4302 /* If there is a pending AST wait for completion */ 4303 if (ps->ps_nsamples == PMC_SAMPLE_INUSE) { 4304 /* Need a rescan at a later time. */ 4305 CPU_SET_ATOMIC(cpu, &pmc_cpumask); 4306 break; 4307 } 4308 4309 PMCDBG(SAM,OPS,1,"cpu=%d pm=%p n=%d fl=%x wr=%d rd=%d", cpu, 4310 pm, ps->ps_nsamples, ps->ps_flags, 4311 (int) (psb->ps_write - psb->ps_samples), 4312 (int) (psb->ps_read - psb->ps_samples)); 4313 4314 /* 4315 * If this is a process-mode PMC that is attached to 4316 * its owner, and if the PC is in user mode, update 4317 * profiling statistics like timer-based profiling 4318 * would have done. 4319 */ 4320 if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) { 4321 if (ps->ps_flags & PMC_CC_F_USERSPACE) { 4322 td = FIRST_THREAD_IN_PROC(po->po_owner); 4323 addupc_intr(td, ps->ps_pc[0], 1); 4324 } 4325 goto entrydone; 4326 } 4327 4328 /* 4329 * Otherwise, this is either a sampling mode PMC that 4330 * is attached to a different process than its owner, 4331 * or a system-wide sampling PMC. Dispatch a log 4332 * entry to the PMC's owner process. 4333 */ 4334 pmclog_process_callchain(pm, ps); 4335 4336 entrydone: 4337 ps->ps_nsamples = 0; /* mark entry as free */ 4338 atomic_subtract_rel_int(&pm->pm_runcount, 1); 4339 4340 /* increment read pointer, modulo sample size */ 4341 if (++ps == psb->ps_fence) 4342 psb->ps_read = psb->ps_samples; 4343 else 4344 psb->ps_read = ps; 4345 } 4346 4347 atomic_add_int(&pmc_stats.pm_log_sweeps, 1); 4348 4349 /* Do not re-enable stalled PMCs if we failed to process any samples */ 4350 if (n == 0) 4351 return; 4352 4353 /* 4354 * Restart any stalled sampling PMCs on this CPU. 4355 * 4356 * If the NMI handler sets the pm_stalled field of a PMC after 4357 * the check below, we'll end up processing the stalled PMC at 4358 * the next hardclock tick. 4359 */ 4360 for (n = 0; n < md->pmd_npmc; n++) { 4361 pcd = pmc_ri_to_classdep(md, n, &adjri); 4362 KASSERT(pcd != NULL, 4363 ("[pmc,%d] null pcd ri=%d", __LINE__, n)); 4364 (void) (*pcd->pcd_get_config)(cpu,adjri,&pm); 4365 4366 if (pm == NULL || /* !cfg'ed */ 4367 pm->pm_state != PMC_STATE_RUNNING || /* !active */ 4368 !PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)) || /* !sampling */ 4369 pm->pm_stalled == 0) /* !stalled */ 4370 continue; 4371 4372 pm->pm_stalled = 0; 4373 (*pcd->pcd_start_pmc)(cpu, adjri); 4374 } 4375 } 4376 4377 /* 4378 * Event handlers. 4379 */ 4380 4381 /* 4382 * Handle a process exit. 4383 * 4384 * Remove this process from all hash tables. If this process 4385 * owned any PMCs, turn off those PMCs and deallocate them, 4386 * removing any associations with target processes. 4387 * 4388 * This function will be called by the last 'thread' of a 4389 * process. 4390 * 4391 * XXX This eventhandler gets called early in the exit process. 4392 * Consider using a 'hook' invocation from thread_exit() or equivalent 4393 * spot. Another negative is that kse_exit doesn't seem to call 4394 * exit1() [??]. 4395 * 4396 */ 4397 4398 static void 4399 pmc_process_exit(void *arg __unused, struct proc *p) 4400 { 4401 struct pmc *pm; 4402 int adjri, cpu; 4403 unsigned int ri; 4404 int is_using_hwpmcs; 4405 struct pmc_owner *po; 4406 struct pmc_process *pp; 4407 struct pmc_classdep *pcd; 4408 pmc_value_t newvalue, tmp; 4409 4410 PROC_LOCK(p); 4411 is_using_hwpmcs = p->p_flag & P_HWPMC; 4412 PROC_UNLOCK(p); 4413 4414 /* 4415 * Log a sysexit event to all SS PMC owners. 4416 */ 4417 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 4418 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 4419 pmclog_process_sysexit(po, p->p_pid); 4420 4421 if (!is_using_hwpmcs) 4422 return; 4423 4424 PMC_GET_SX_XLOCK(); 4425 PMCDBG(PRC,EXT,1,"process-exit proc=%p (%d, %s)", p, p->p_pid, 4426 p->p_comm); 4427 4428 /* 4429 * Since this code is invoked by the last thread in an exiting 4430 * process, we would have context switched IN at some prior 4431 * point. However, with PREEMPTION, kernel mode context 4432 * switches may happen any time, so we want to disable a 4433 * context switch OUT till we get any PMCs targetting this 4434 * process off the hardware. 4435 * 4436 * We also need to atomically remove this process' 4437 * entry from our target process hash table, using 4438 * PMC_FLAG_REMOVE. 4439 */ 4440 PMCDBG(PRC,EXT,1, "process-exit proc=%p (%d, %s)", p, p->p_pid, 4441 p->p_comm); 4442 4443 critical_enter(); /* no preemption */ 4444 4445 cpu = curthread->td_oncpu; 4446 4447 if ((pp = pmc_find_process_descriptor(p, 4448 PMC_FLAG_REMOVE)) != NULL) { 4449 4450 PMCDBG(PRC,EXT,2, 4451 "process-exit proc=%p pmc-process=%p", p, pp); 4452 4453 /* 4454 * The exiting process could the target of 4455 * some PMCs which will be running on 4456 * currently executing CPU. 4457 * 4458 * We need to turn these PMCs off like we 4459 * would do at context switch OUT time. 4460 */ 4461 for (ri = 0; ri < md->pmd_npmc; ri++) { 4462 4463 /* 4464 * Pick up the pmc pointer from hardware 4465 * state similar to the CSW_OUT code. 4466 */ 4467 pm = NULL; 4468 4469 pcd = pmc_ri_to_classdep(md, ri, &adjri); 4470 4471 (void) (*pcd->pcd_get_config)(cpu, adjri, &pm); 4472 4473 PMCDBG(PRC,EXT,2, "ri=%d pm=%p", ri, pm); 4474 4475 if (pm == NULL || 4476 !PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) 4477 continue; 4478 4479 PMCDBG(PRC,EXT,2, "ppmcs[%d]=%p pm=%p " 4480 "state=%d", ri, pp->pp_pmcs[ri].pp_pmc, 4481 pm, pm->pm_state); 4482 4483 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 4484 ("[pmc,%d] ri mismatch pmc(%d) ri(%d)", 4485 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 4486 4487 KASSERT(pm == pp->pp_pmcs[ri].pp_pmc, 4488 ("[pmc,%d] pm %p != pp_pmcs[%d] %p", 4489 __LINE__, pm, ri, pp->pp_pmcs[ri].pp_pmc)); 4490 4491 (void) pcd->pcd_stop_pmc(cpu, adjri); 4492 4493 KASSERT(pm->pm_runcount > 0, 4494 ("[pmc,%d] bad runcount ri %d rc %d", 4495 __LINE__, ri, pm->pm_runcount)); 4496 4497 /* Stop hardware only if it is actually running */ 4498 if (pm->pm_state == PMC_STATE_RUNNING && 4499 pm->pm_stalled == 0) { 4500 pcd->pcd_read_pmc(cpu, adjri, &newvalue); 4501 tmp = newvalue - 4502 PMC_PCPU_SAVED(cpu,ri); 4503 4504 mtx_pool_lock_spin(pmc_mtxpool, pm); 4505 pm->pm_gv.pm_savedvalue += tmp; 4506 pp->pp_pmcs[ri].pp_pmcval += tmp; 4507 mtx_pool_unlock_spin(pmc_mtxpool, pm); 4508 } 4509 4510 atomic_subtract_rel_int(&pm->pm_runcount,1); 4511 4512 KASSERT((int) pm->pm_runcount >= 0, 4513 ("[pmc,%d] runcount is %d", __LINE__, ri)); 4514 4515 (void) pcd->pcd_config_pmc(cpu, adjri, NULL); 4516 } 4517 4518 /* 4519 * Inform the MD layer of this pseudo "context switch 4520 * out" 4521 */ 4522 (void) md->pmd_switch_out(pmc_pcpu[cpu], pp); 4523 4524 critical_exit(); /* ok to be pre-empted now */ 4525 4526 /* 4527 * Unlink this process from the PMCs that are 4528 * targetting it. This will send a signal to 4529 * all PMC owner's whose PMCs are orphaned. 4530 * 4531 * Log PMC value at exit time if requested. 4532 */ 4533 for (ri = 0; ri < md->pmd_npmc; ri++) 4534 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) { 4535 if (pm->pm_flags & PMC_F_NEEDS_LOGFILE && 4536 PMC_IS_COUNTING_MODE(PMC_TO_MODE(pm))) 4537 pmclog_process_procexit(pm, pp); 4538 pmc_unlink_target_process(pm, pp); 4539 } 4540 free(pp, M_PMC); 4541 4542 } else 4543 critical_exit(); /* pp == NULL */ 4544 4545 4546 /* 4547 * If the process owned PMCs, free them up and free up 4548 * memory. 4549 */ 4550 if ((po = pmc_find_owner_descriptor(p)) != NULL) { 4551 pmc_remove_owner(po); 4552 pmc_destroy_owner_descriptor(po); 4553 } 4554 4555 sx_xunlock(&pmc_sx); 4556 } 4557 4558 /* 4559 * Handle a process fork. 4560 * 4561 * If the parent process 'p1' is under HWPMC monitoring, then copy 4562 * over any attached PMCs that have 'do_descendants' semantics. 4563 */ 4564 4565 static void 4566 pmc_process_fork(void *arg __unused, struct proc *p1, struct proc *newproc, 4567 int flags) 4568 { 4569 int is_using_hwpmcs; 4570 unsigned int ri; 4571 uint32_t do_descendants; 4572 struct pmc *pm; 4573 struct pmc_owner *po; 4574 struct pmc_process *ppnew, *ppold; 4575 4576 (void) flags; /* unused parameter */ 4577 4578 PROC_LOCK(p1); 4579 is_using_hwpmcs = p1->p_flag & P_HWPMC; 4580 PROC_UNLOCK(p1); 4581 4582 /* 4583 * If there are system-wide sampling PMCs active, we need to 4584 * log all fork events to their owner's logs. 4585 */ 4586 4587 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 4588 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 4589 pmclog_process_procfork(po, p1->p_pid, newproc->p_pid); 4590 4591 if (!is_using_hwpmcs) 4592 return; 4593 4594 PMC_GET_SX_XLOCK(); 4595 PMCDBG(PMC,FRK,1, "process-fork proc=%p (%d, %s) -> %p", p1, 4596 p1->p_pid, p1->p_comm, newproc); 4597 4598 /* 4599 * If the parent process (curthread->td_proc) is a 4600 * target of any PMCs, look for PMCs that are to be 4601 * inherited, and link these into the new process 4602 * descriptor. 4603 */ 4604 if ((ppold = pmc_find_process_descriptor(curthread->td_proc, 4605 PMC_FLAG_NONE)) == NULL) 4606 goto done; /* nothing to do */ 4607 4608 do_descendants = 0; 4609 for (ri = 0; ri < md->pmd_npmc; ri++) 4610 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL) 4611 do_descendants |= pm->pm_flags & PMC_F_DESCENDANTS; 4612 if (do_descendants == 0) /* nothing to do */ 4613 goto done; 4614 4615 /* allocate a descriptor for the new process */ 4616 if ((ppnew = pmc_find_process_descriptor(newproc, 4617 PMC_FLAG_ALLOCATE)) == NULL) 4618 goto done; 4619 4620 /* 4621 * Run through all PMCs that were targeting the old process 4622 * and which specified F_DESCENDANTS and attach them to the 4623 * new process. 4624 * 4625 * Log the fork event to all owners of PMCs attached to this 4626 * process, if not already logged. 4627 */ 4628 for (ri = 0; ri < md->pmd_npmc; ri++) 4629 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL && 4630 (pm->pm_flags & PMC_F_DESCENDANTS)) { 4631 pmc_link_target_process(pm, ppnew); 4632 po = pm->pm_owner; 4633 if (po->po_sscount == 0 && 4634 po->po_flags & PMC_PO_OWNS_LOGFILE) 4635 pmclog_process_procfork(po, p1->p_pid, 4636 newproc->p_pid); 4637 } 4638 4639 /* 4640 * Now mark the new process as being tracked by this driver. 4641 */ 4642 PROC_LOCK(newproc); 4643 newproc->p_flag |= P_HWPMC; 4644 PROC_UNLOCK(newproc); 4645 4646 done: 4647 sx_xunlock(&pmc_sx); 4648 } 4649 4650 4651 /* 4652 * initialization 4653 */ 4654 4655 static const char *pmc_name_of_pmcclass[] = { 4656 #undef __PMC_CLASS 4657 #define __PMC_CLASS(N) #N , 4658 __PMC_CLASSES() 4659 }; 4660 4661 /* 4662 * Base class initializer: allocate structure and set default classes. 4663 */ 4664 struct pmc_mdep * 4665 pmc_mdep_alloc(int nclasses) 4666 { 4667 struct pmc_mdep *md; 4668 int n; 4669 4670 /* SOFT + md classes */ 4671 n = 1 + nclasses; 4672 md = malloc(sizeof(struct pmc_mdep) + n * 4673 sizeof(struct pmc_classdep), M_PMC, M_WAITOK|M_ZERO); 4674 if (md != NULL) { 4675 md->pmd_nclass = n; 4676 4677 /* Add base class. */ 4678 pmc_soft_initialize(md); 4679 } 4680 4681 return md; 4682 } 4683 4684 void 4685 pmc_mdep_free(struct pmc_mdep *md) 4686 { 4687 pmc_soft_finalize(md); 4688 free(md, M_PMC); 4689 } 4690 4691 static int 4692 generic_switch_in(struct pmc_cpu *pc, struct pmc_process *pp) 4693 { 4694 (void) pc; (void) pp; 4695 4696 return (0); 4697 } 4698 4699 static int 4700 generic_switch_out(struct pmc_cpu *pc, struct pmc_process *pp) 4701 { 4702 (void) pc; (void) pp; 4703 4704 return (0); 4705 } 4706 4707 static struct pmc_mdep * 4708 pmc_generic_cpu_initialize(void) 4709 { 4710 struct pmc_mdep *md; 4711 4712 md = pmc_mdep_alloc(0); 4713 4714 md->pmd_cputype = PMC_CPU_GENERIC; 4715 4716 md->pmd_pcpu_init = NULL; 4717 md->pmd_pcpu_fini = NULL; 4718 md->pmd_switch_in = generic_switch_in; 4719 md->pmd_switch_out = generic_switch_out; 4720 4721 return (md); 4722 } 4723 4724 static void 4725 pmc_generic_cpu_finalize(struct pmc_mdep *md) 4726 { 4727 (void) md; 4728 } 4729 4730 4731 static int 4732 pmc_initialize(void) 4733 { 4734 int c, cpu, error, n, ri; 4735 unsigned int maxcpu; 4736 struct pmc_binding pb; 4737 struct pmc_sample *ps; 4738 struct pmc_classdep *pcd; 4739 struct pmc_samplebuffer *sb; 4740 4741 md = NULL; 4742 error = 0; 4743 4744 #ifdef DEBUG 4745 /* parse debug flags first */ 4746 if (TUNABLE_STR_FETCH(PMC_SYSCTL_NAME_PREFIX "debugflags", 4747 pmc_debugstr, sizeof(pmc_debugstr))) 4748 pmc_debugflags_parse(pmc_debugstr, 4749 pmc_debugstr+strlen(pmc_debugstr)); 4750 #endif 4751 4752 PMCDBG(MOD,INI,0, "PMC Initialize (version %x)", PMC_VERSION); 4753 4754 /* check kernel version */ 4755 if (pmc_kernel_version != PMC_VERSION) { 4756 if (pmc_kernel_version == 0) 4757 printf("hwpmc: this kernel has not been compiled with " 4758 "'options HWPMC_HOOKS'.\n"); 4759 else 4760 printf("hwpmc: kernel version (0x%x) does not match " 4761 "module version (0x%x).\n", pmc_kernel_version, 4762 PMC_VERSION); 4763 return EPROGMISMATCH; 4764 } 4765 4766 /* 4767 * check sysctl parameters 4768 */ 4769 4770 if (pmc_hashsize <= 0) { 4771 (void) printf("hwpmc: tunable \"hashsize\"=%d must be " 4772 "greater than zero.\n", pmc_hashsize); 4773 pmc_hashsize = PMC_HASH_SIZE; 4774 } 4775 4776 if (pmc_nsamples <= 0 || pmc_nsamples > 65535) { 4777 (void) printf("hwpmc: tunable \"nsamples\"=%d out of " 4778 "range.\n", pmc_nsamples); 4779 pmc_nsamples = PMC_NSAMPLES; 4780 } 4781 4782 if (pmc_callchaindepth <= 0 || 4783 pmc_callchaindepth > PMC_CALLCHAIN_DEPTH_MAX) { 4784 (void) printf("hwpmc: tunable \"callchaindepth\"=%d out of " 4785 "range.\n", pmc_callchaindepth); 4786 pmc_callchaindepth = PMC_CALLCHAIN_DEPTH; 4787 } 4788 4789 md = pmc_md_initialize(); 4790 if (md == NULL) { 4791 /* Default to generic CPU. */ 4792 md = pmc_generic_cpu_initialize(); 4793 if (md == NULL) 4794 return (ENOSYS); 4795 } 4796 4797 KASSERT(md->pmd_nclass >= 1 && md->pmd_npmc >= 1, 4798 ("[pmc,%d] no classes or pmcs", __LINE__)); 4799 4800 /* Compute the map from row-indices to classdep pointers. */ 4801 pmc_rowindex_to_classdep = malloc(sizeof(struct pmc_classdep *) * 4802 md->pmd_npmc, M_PMC, M_WAITOK|M_ZERO); 4803 4804 for (n = 0; n < md->pmd_npmc; n++) 4805 pmc_rowindex_to_classdep[n] = NULL; 4806 for (ri = c = 0; c < md->pmd_nclass; c++) { 4807 pcd = &md->pmd_classdep[c]; 4808 for (n = 0; n < pcd->pcd_num; n++, ri++) 4809 pmc_rowindex_to_classdep[ri] = pcd; 4810 } 4811 4812 KASSERT(ri == md->pmd_npmc, 4813 ("[pmc,%d] npmc miscomputed: ri=%d, md->npmc=%d", __LINE__, 4814 ri, md->pmd_npmc)); 4815 4816 maxcpu = pmc_cpu_max(); 4817 4818 /* allocate space for the per-cpu array */ 4819 pmc_pcpu = malloc(maxcpu * sizeof(struct pmc_cpu *), M_PMC, 4820 M_WAITOK|M_ZERO); 4821 4822 /* per-cpu 'saved values' for managing process-mode PMCs */ 4823 pmc_pcpu_saved = malloc(sizeof(pmc_value_t) * maxcpu * md->pmd_npmc, 4824 M_PMC, M_WAITOK); 4825 4826 /* Perform CPU-dependent initialization. */ 4827 pmc_save_cpu_binding(&pb); 4828 error = 0; 4829 for (cpu = 0; error == 0 && cpu < maxcpu; cpu++) { 4830 if (!pmc_cpu_is_active(cpu)) 4831 continue; 4832 pmc_select_cpu(cpu); 4833 pmc_pcpu[cpu] = malloc(sizeof(struct pmc_cpu) + 4834 md->pmd_npmc * sizeof(struct pmc_hw *), M_PMC, 4835 M_WAITOK|M_ZERO); 4836 if (md->pmd_pcpu_init) 4837 error = md->pmd_pcpu_init(md, cpu); 4838 for (n = 0; error == 0 && n < md->pmd_nclass; n++) 4839 error = md->pmd_classdep[n].pcd_pcpu_init(md, cpu); 4840 } 4841 pmc_restore_cpu_binding(&pb); 4842 4843 if (error) 4844 return (error); 4845 4846 /* allocate space for the sample array */ 4847 for (cpu = 0; cpu < maxcpu; cpu++) { 4848 if (!pmc_cpu_is_active(cpu)) 4849 continue; 4850 4851 sb = malloc(sizeof(struct pmc_samplebuffer) + 4852 pmc_nsamples * sizeof(struct pmc_sample), M_PMC, 4853 M_WAITOK|M_ZERO); 4854 sb->ps_read = sb->ps_write = sb->ps_samples; 4855 sb->ps_fence = sb->ps_samples + pmc_nsamples; 4856 4857 KASSERT(pmc_pcpu[cpu] != NULL, 4858 ("[pmc,%d] cpu=%d Null per-cpu data", __LINE__, cpu)); 4859 4860 sb->ps_callchains = malloc(pmc_callchaindepth * pmc_nsamples * 4861 sizeof(uintptr_t), M_PMC, M_WAITOK|M_ZERO); 4862 4863 for (n = 0, ps = sb->ps_samples; n < pmc_nsamples; n++, ps++) 4864 ps->ps_pc = sb->ps_callchains + 4865 (n * pmc_callchaindepth); 4866 4867 pmc_pcpu[cpu]->pc_sb[PMC_HR] = sb; 4868 4869 sb = malloc(sizeof(struct pmc_samplebuffer) + 4870 pmc_nsamples * sizeof(struct pmc_sample), M_PMC, 4871 M_WAITOK|M_ZERO); 4872 sb->ps_read = sb->ps_write = sb->ps_samples; 4873 sb->ps_fence = sb->ps_samples + pmc_nsamples; 4874 4875 KASSERT(pmc_pcpu[cpu] != NULL, 4876 ("[pmc,%d] cpu=%d Null per-cpu data", __LINE__, cpu)); 4877 4878 sb->ps_callchains = malloc(pmc_callchaindepth * pmc_nsamples * 4879 sizeof(uintptr_t), M_PMC, M_WAITOK|M_ZERO); 4880 4881 for (n = 0, ps = sb->ps_samples; n < pmc_nsamples; n++, ps++) 4882 ps->ps_pc = sb->ps_callchains + 4883 (n * pmc_callchaindepth); 4884 4885 pmc_pcpu[cpu]->pc_sb[PMC_SR] = sb; 4886 } 4887 4888 /* allocate space for the row disposition array */ 4889 pmc_pmcdisp = malloc(sizeof(enum pmc_mode) * md->pmd_npmc, 4890 M_PMC, M_WAITOK|M_ZERO); 4891 4892 KASSERT(pmc_pmcdisp != NULL, 4893 ("[pmc,%d] pmcdisp allocation returned NULL", __LINE__)); 4894 4895 /* mark all PMCs as available */ 4896 for (n = 0; n < (int) md->pmd_npmc; n++) 4897 PMC_MARK_ROW_FREE(n); 4898 4899 /* allocate thread hash tables */ 4900 pmc_ownerhash = hashinit(pmc_hashsize, M_PMC, 4901 &pmc_ownerhashmask); 4902 4903 pmc_processhash = hashinit(pmc_hashsize, M_PMC, 4904 &pmc_processhashmask); 4905 mtx_init(&pmc_processhash_mtx, "pmc-process-hash", "pmc-leaf", 4906 MTX_SPIN); 4907 4908 LIST_INIT(&pmc_ss_owners); 4909 pmc_ss_count = 0; 4910 4911 /* allocate a pool of spin mutexes */ 4912 pmc_mtxpool = mtx_pool_create("pmc-leaf", pmc_mtxpool_size, 4913 MTX_SPIN); 4914 4915 PMCDBG(MOD,INI,1, "pmc_ownerhash=%p, mask=0x%lx " 4916 "targethash=%p mask=0x%lx", pmc_ownerhash, pmc_ownerhashmask, 4917 pmc_processhash, pmc_processhashmask); 4918 4919 /* register process {exit,fork,exec} handlers */ 4920 pmc_exit_tag = EVENTHANDLER_REGISTER(process_exit, 4921 pmc_process_exit, NULL, EVENTHANDLER_PRI_ANY); 4922 pmc_fork_tag = EVENTHANDLER_REGISTER(process_fork, 4923 pmc_process_fork, NULL, EVENTHANDLER_PRI_ANY); 4924 4925 /* initialize logging */ 4926 pmclog_initialize(); 4927 4928 /* set hook functions */ 4929 pmc_intr = md->pmd_intr; 4930 pmc_hook = pmc_hook_handler; 4931 4932 if (error == 0) { 4933 printf(PMC_MODULE_NAME ":"); 4934 for (n = 0; n < (int) md->pmd_nclass; n++) { 4935 pcd = &md->pmd_classdep[n]; 4936 printf(" %s/%d/%d/0x%b", 4937 pmc_name_of_pmcclass[pcd->pcd_class], 4938 pcd->pcd_num, 4939 pcd->pcd_width, 4940 pcd->pcd_caps, 4941 "\20" 4942 "\1INT\2USR\3SYS\4EDG\5THR" 4943 "\6REA\7WRI\10INV\11QUA\12PRC" 4944 "\13TAG\14CSC"); 4945 } 4946 printf("\n"); 4947 } 4948 4949 return (error); 4950 } 4951 4952 /* prepare to be unloaded */ 4953 static void 4954 pmc_cleanup(void) 4955 { 4956 int c, cpu; 4957 unsigned int maxcpu; 4958 struct pmc_ownerhash *ph; 4959 struct pmc_owner *po, *tmp; 4960 struct pmc_binding pb; 4961 #ifdef DEBUG 4962 struct pmc_processhash *prh; 4963 #endif 4964 4965 PMCDBG(MOD,INI,0, "%s", "cleanup"); 4966 4967 /* switch off sampling */ 4968 CPU_ZERO(&pmc_cpumask); 4969 pmc_intr = NULL; 4970 4971 sx_xlock(&pmc_sx); 4972 if (pmc_hook == NULL) { /* being unloaded already */ 4973 sx_xunlock(&pmc_sx); 4974 return; 4975 } 4976 4977 pmc_hook = NULL; /* prevent new threads from entering module */ 4978 4979 /* deregister event handlers */ 4980 EVENTHANDLER_DEREGISTER(process_fork, pmc_fork_tag); 4981 EVENTHANDLER_DEREGISTER(process_exit, pmc_exit_tag); 4982 4983 /* send SIGBUS to all owner threads, free up allocations */ 4984 if (pmc_ownerhash) 4985 for (ph = pmc_ownerhash; 4986 ph <= &pmc_ownerhash[pmc_ownerhashmask]; 4987 ph++) { 4988 LIST_FOREACH_SAFE(po, ph, po_next, tmp) { 4989 pmc_remove_owner(po); 4990 4991 /* send SIGBUS to owner processes */ 4992 PMCDBG(MOD,INI,2, "cleanup signal proc=%p " 4993 "(%d, %s)", po->po_owner, 4994 po->po_owner->p_pid, 4995 po->po_owner->p_comm); 4996 4997 PROC_LOCK(po->po_owner); 4998 kern_psignal(po->po_owner, SIGBUS); 4999 PROC_UNLOCK(po->po_owner); 5000 5001 pmc_destroy_owner_descriptor(po); 5002 } 5003 } 5004 5005 /* reclaim allocated data structures */ 5006 if (pmc_mtxpool) 5007 mtx_pool_destroy(&pmc_mtxpool); 5008 5009 mtx_destroy(&pmc_processhash_mtx); 5010 if (pmc_processhash) { 5011 #ifdef DEBUG 5012 struct pmc_process *pp; 5013 5014 PMCDBG(MOD,INI,3, "%s", "destroy process hash"); 5015 for (prh = pmc_processhash; 5016 prh <= &pmc_processhash[pmc_processhashmask]; 5017 prh++) 5018 LIST_FOREACH(pp, prh, pp_next) 5019 PMCDBG(MOD,INI,3, "pid=%d", pp->pp_proc->p_pid); 5020 #endif 5021 5022 hashdestroy(pmc_processhash, M_PMC, pmc_processhashmask); 5023 pmc_processhash = NULL; 5024 } 5025 5026 if (pmc_ownerhash) { 5027 PMCDBG(MOD,INI,3, "%s", "destroy owner hash"); 5028 hashdestroy(pmc_ownerhash, M_PMC, pmc_ownerhashmask); 5029 pmc_ownerhash = NULL; 5030 } 5031 5032 KASSERT(LIST_EMPTY(&pmc_ss_owners), 5033 ("[pmc,%d] Global SS owner list not empty", __LINE__)); 5034 KASSERT(pmc_ss_count == 0, 5035 ("[pmc,%d] Global SS count not empty", __LINE__)); 5036 5037 /* do processor and pmc-class dependent cleanup */ 5038 maxcpu = pmc_cpu_max(); 5039 5040 PMCDBG(MOD,INI,3, "%s", "md cleanup"); 5041 if (md) { 5042 pmc_save_cpu_binding(&pb); 5043 for (cpu = 0; cpu < maxcpu; cpu++) { 5044 PMCDBG(MOD,INI,1,"pmc-cleanup cpu=%d pcs=%p", 5045 cpu, pmc_pcpu[cpu]); 5046 if (!pmc_cpu_is_active(cpu) || pmc_pcpu[cpu] == NULL) 5047 continue; 5048 pmc_select_cpu(cpu); 5049 for (c = 0; c < md->pmd_nclass; c++) 5050 md->pmd_classdep[c].pcd_pcpu_fini(md, cpu); 5051 if (md->pmd_pcpu_fini) 5052 md->pmd_pcpu_fini(md, cpu); 5053 } 5054 5055 if (md->pmd_cputype == PMC_CPU_GENERIC) 5056 pmc_generic_cpu_finalize(md); 5057 else 5058 pmc_md_finalize(md); 5059 5060 pmc_mdep_free(md); 5061 md = NULL; 5062 pmc_restore_cpu_binding(&pb); 5063 } 5064 5065 /* Free per-cpu descriptors. */ 5066 for (cpu = 0; cpu < maxcpu; cpu++) { 5067 if (!pmc_cpu_is_active(cpu)) 5068 continue; 5069 KASSERT(pmc_pcpu[cpu]->pc_sb[PMC_HR] != NULL, 5070 ("[pmc,%d] Null hw cpu sample buffer cpu=%d", __LINE__, 5071 cpu)); 5072 KASSERT(pmc_pcpu[cpu]->pc_sb[PMC_SR] != NULL, 5073 ("[pmc,%d] Null sw cpu sample buffer cpu=%d", __LINE__, 5074 cpu)); 5075 free(pmc_pcpu[cpu]->pc_sb[PMC_HR]->ps_callchains, M_PMC); 5076 free(pmc_pcpu[cpu]->pc_sb[PMC_HR], M_PMC); 5077 free(pmc_pcpu[cpu]->pc_sb[PMC_SR]->ps_callchains, M_PMC); 5078 free(pmc_pcpu[cpu]->pc_sb[PMC_SR], M_PMC); 5079 free(pmc_pcpu[cpu], M_PMC); 5080 } 5081 5082 free(pmc_pcpu, M_PMC); 5083 pmc_pcpu = NULL; 5084 5085 free(pmc_pcpu_saved, M_PMC); 5086 pmc_pcpu_saved = NULL; 5087 5088 if (pmc_pmcdisp) { 5089 free(pmc_pmcdisp, M_PMC); 5090 pmc_pmcdisp = NULL; 5091 } 5092 5093 if (pmc_rowindex_to_classdep) { 5094 free(pmc_rowindex_to_classdep, M_PMC); 5095 pmc_rowindex_to_classdep = NULL; 5096 } 5097 5098 pmclog_shutdown(); 5099 5100 sx_xunlock(&pmc_sx); /* we are done */ 5101 } 5102 5103 /* 5104 * The function called at load/unload. 5105 */ 5106 5107 static int 5108 load (struct module *module __unused, int cmd, void *arg __unused) 5109 { 5110 int error; 5111 5112 error = 0; 5113 5114 switch (cmd) { 5115 case MOD_LOAD : 5116 /* initialize the subsystem */ 5117 error = pmc_initialize(); 5118 if (error != 0) 5119 break; 5120 PMCDBG(MOD,INI,1, "syscall=%d maxcpu=%d", 5121 pmc_syscall_num, pmc_cpu_max()); 5122 break; 5123 5124 5125 case MOD_UNLOAD : 5126 case MOD_SHUTDOWN: 5127 pmc_cleanup(); 5128 PMCDBG(MOD,INI,1, "%s", "unloaded"); 5129 break; 5130 5131 default : 5132 error = EINVAL; /* XXX should panic(9) */ 5133 break; 5134 } 5135 5136 return error; 5137 } 5138 5139 /* memory pool */ 5140 MALLOC_DEFINE(M_PMC, "pmc", "Memory space for the PMC module"); 5141