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/sched.h> 54 #include <sys/signalvar.h> 55 #include <sys/smp.h> 56 #include <sys/sx.h> 57 #include <sys/sysctl.h> 58 #include <sys/sysent.h> 59 #include <sys/systm.h> 60 #include <sys/vnode.h> 61 62 #include <sys/linker.h> /* needs to be after <sys/malloc.h> */ 63 64 #include <machine/atomic.h> 65 #include <machine/md_var.h> 66 67 #include <vm/vm.h> 68 #include <vm/vm_extern.h> 69 #include <vm/pmap.h> 70 #include <vm/vm_map.h> 71 #include <vm/vm_object.h> 72 73 /* 74 * Types 75 */ 76 77 enum pmc_flags { 78 PMC_FLAG_NONE = 0x00, /* do nothing */ 79 PMC_FLAG_REMOVE = 0x01, /* atomically remove entry from hash */ 80 PMC_FLAG_ALLOCATE = 0x02, /* add entry to hash if not found */ 81 }; 82 83 /* 84 * The offset in sysent where the syscall is allocated. 85 */ 86 87 static int pmc_syscall_num = NO_SYSCALL; 88 struct pmc_cpu **pmc_pcpu; /* per-cpu state */ 89 pmc_value_t *pmc_pcpu_saved; /* saved PMC values: CSW handling */ 90 91 #define PMC_PCPU_SAVED(C,R) pmc_pcpu_saved[(R) + md->pmd_npmc*(C)] 92 93 struct mtx_pool *pmc_mtxpool; 94 static int *pmc_pmcdisp; /* PMC row dispositions */ 95 96 #define PMC_ROW_DISP_IS_FREE(R) (pmc_pmcdisp[(R)] == 0) 97 #define PMC_ROW_DISP_IS_THREAD(R) (pmc_pmcdisp[(R)] > 0) 98 #define PMC_ROW_DISP_IS_STANDALONE(R) (pmc_pmcdisp[(R)] < 0) 99 100 #define PMC_MARK_ROW_FREE(R) do { \ 101 pmc_pmcdisp[(R)] = 0; \ 102 } while (0) 103 104 #define PMC_MARK_ROW_STANDALONE(R) do { \ 105 KASSERT(pmc_pmcdisp[(R)] <= 0, ("[pmc,%d] row disposition error", \ 106 __LINE__)); \ 107 atomic_add_int(&pmc_pmcdisp[(R)], -1); \ 108 KASSERT(pmc_pmcdisp[(R)] >= (-pmc_cpu_max_active()), \ 109 ("[pmc,%d] row disposition error", __LINE__)); \ 110 } while (0) 111 112 #define PMC_UNMARK_ROW_STANDALONE(R) do { \ 113 atomic_add_int(&pmc_pmcdisp[(R)], 1); \ 114 KASSERT(pmc_pmcdisp[(R)] <= 0, ("[pmc,%d] row disposition error", \ 115 __LINE__)); \ 116 } while (0) 117 118 #define PMC_MARK_ROW_THREAD(R) do { \ 119 KASSERT(pmc_pmcdisp[(R)] >= 0, ("[pmc,%d] row disposition error", \ 120 __LINE__)); \ 121 atomic_add_int(&pmc_pmcdisp[(R)], 1); \ 122 } while (0) 123 124 #define PMC_UNMARK_ROW_THREAD(R) do { \ 125 atomic_add_int(&pmc_pmcdisp[(R)], -1); \ 126 KASSERT(pmc_pmcdisp[(R)] >= 0, ("[pmc,%d] row disposition error", \ 127 __LINE__)); \ 128 } while (0) 129 130 131 /* various event handlers */ 132 static eventhandler_tag pmc_exit_tag, pmc_fork_tag; 133 134 /* Module statistics */ 135 struct pmc_op_getdriverstats pmc_stats; 136 137 /* Machine/processor dependent operations */ 138 static struct pmc_mdep *md; 139 140 /* 141 * Hash tables mapping owner processes and target threads to PMCs. 142 */ 143 144 struct mtx pmc_processhash_mtx; /* spin mutex */ 145 static u_long pmc_processhashmask; 146 static LIST_HEAD(pmc_processhash, pmc_process) *pmc_processhash; 147 148 /* 149 * Hash table of PMC owner descriptors. This table is protected by 150 * the shared PMC "sx" lock. 151 */ 152 153 static u_long pmc_ownerhashmask; 154 static LIST_HEAD(pmc_ownerhash, pmc_owner) *pmc_ownerhash; 155 156 /* 157 * List of PMC owners with system-wide sampling PMCs. 158 */ 159 160 static LIST_HEAD(, pmc_owner) pmc_ss_owners; 161 162 163 /* 164 * A map of row indices to classdep structures. 165 */ 166 static struct pmc_classdep **pmc_rowindex_to_classdep; 167 168 /* 169 * Prototypes 170 */ 171 172 #ifdef DEBUG 173 static int pmc_debugflags_sysctl_handler(SYSCTL_HANDLER_ARGS); 174 static int pmc_debugflags_parse(char *newstr, char *fence); 175 #endif 176 177 static int load(struct module *module, int cmd, void *arg); 178 static int pmc_attach_process(struct proc *p, struct pmc *pm); 179 static struct pmc *pmc_allocate_pmc_descriptor(void); 180 static struct pmc_owner *pmc_allocate_owner_descriptor(struct proc *p); 181 static int pmc_attach_one_process(struct proc *p, struct pmc *pm); 182 static int pmc_can_allocate_rowindex(struct proc *p, unsigned int ri, 183 int cpu); 184 static int pmc_can_attach(struct pmc *pm, struct proc *p); 185 static void pmc_capture_user_callchain(int cpu, struct trapframe *tf); 186 static void pmc_cleanup(void); 187 static int pmc_detach_process(struct proc *p, struct pmc *pm); 188 static int pmc_detach_one_process(struct proc *p, struct pmc *pm, 189 int flags); 190 static void pmc_destroy_owner_descriptor(struct pmc_owner *po); 191 static struct pmc_owner *pmc_find_owner_descriptor(struct proc *p); 192 static int pmc_find_pmc(pmc_id_t pmcid, struct pmc **pm); 193 static struct pmc *pmc_find_pmc_descriptor_in_process(struct pmc_owner *po, 194 pmc_id_t pmc); 195 static struct pmc_process *pmc_find_process_descriptor(struct proc *p, 196 uint32_t mode); 197 static void pmc_force_context_switch(void); 198 static void pmc_link_target_process(struct pmc *pm, 199 struct pmc_process *pp); 200 static void pmc_log_all_process_mappings(struct pmc_owner *po); 201 static void pmc_log_kernel_mappings(struct pmc *pm); 202 static void pmc_log_process_mappings(struct pmc_owner *po, struct proc *p); 203 static void pmc_maybe_remove_owner(struct pmc_owner *po); 204 static void pmc_process_csw_in(struct thread *td); 205 static void pmc_process_csw_out(struct thread *td); 206 static void pmc_process_exit(void *arg, struct proc *p); 207 static void pmc_process_fork(void *arg, struct proc *p1, 208 struct proc *p2, int n); 209 static void pmc_process_samples(int cpu); 210 static void pmc_release_pmc_descriptor(struct pmc *pmc); 211 static void pmc_remove_owner(struct pmc_owner *po); 212 static void pmc_remove_process_descriptor(struct pmc_process *pp); 213 static void pmc_restore_cpu_binding(struct pmc_binding *pb); 214 static void pmc_save_cpu_binding(struct pmc_binding *pb); 215 static void pmc_select_cpu(int cpu); 216 static int pmc_start(struct pmc *pm); 217 static int pmc_stop(struct pmc *pm); 218 static int pmc_syscall_handler(struct thread *td, void *syscall_args); 219 static void pmc_unlink_target_process(struct pmc *pmc, 220 struct pmc_process *pp); 221 222 /* 223 * Kernel tunables and sysctl(8) interface. 224 */ 225 226 SYSCTL_NODE(_kern, OID_AUTO, hwpmc, CTLFLAG_RW, 0, "HWPMC parameters"); 227 228 static int pmc_callchaindepth = PMC_CALLCHAIN_DEPTH; 229 TUNABLE_INT(PMC_SYSCTL_NAME_PREFIX "callchaindepth", &pmc_callchaindepth); 230 SYSCTL_INT(_kern_hwpmc, OID_AUTO, callchaindepth, CTLFLAG_TUN|CTLFLAG_RD, 231 &pmc_callchaindepth, 0, "depth of call chain records"); 232 233 #ifdef DEBUG 234 struct pmc_debugflags pmc_debugflags = PMC_DEBUG_DEFAULT_FLAGS; 235 char pmc_debugstr[PMC_DEBUG_STRSIZE]; 236 TUNABLE_STR(PMC_SYSCTL_NAME_PREFIX "debugflags", pmc_debugstr, 237 sizeof(pmc_debugstr)); 238 SYSCTL_PROC(_kern_hwpmc, OID_AUTO, debugflags, 239 CTLTYPE_STRING|CTLFLAG_RW|CTLFLAG_TUN, 240 0, 0, pmc_debugflags_sysctl_handler, "A", "debug flags"); 241 #endif 242 243 /* 244 * kern.hwpmc.hashrows -- determines the number of rows in the 245 * of the hash table used to look up threads 246 */ 247 248 static int pmc_hashsize = PMC_HASH_SIZE; 249 TUNABLE_INT(PMC_SYSCTL_NAME_PREFIX "hashsize", &pmc_hashsize); 250 SYSCTL_INT(_kern_hwpmc, OID_AUTO, hashsize, CTLFLAG_TUN|CTLFLAG_RD, 251 &pmc_hashsize, 0, "rows in hash tables"); 252 253 /* 254 * kern.hwpmc.nsamples --- number of PC samples/callchain stacks per CPU 255 */ 256 257 static int pmc_nsamples = PMC_NSAMPLES; 258 TUNABLE_INT(PMC_SYSCTL_NAME_PREFIX "nsamples", &pmc_nsamples); 259 SYSCTL_INT(_kern_hwpmc, OID_AUTO, nsamples, CTLFLAG_TUN|CTLFLAG_RD, 260 &pmc_nsamples, 0, "number of PC samples per CPU"); 261 262 263 /* 264 * kern.hwpmc.mtxpoolsize -- number of mutexes in the mutex pool. 265 */ 266 267 static int pmc_mtxpool_size = PMC_MTXPOOL_SIZE; 268 TUNABLE_INT(PMC_SYSCTL_NAME_PREFIX "mtxpoolsize", &pmc_mtxpool_size); 269 SYSCTL_INT(_kern_hwpmc, OID_AUTO, mtxpoolsize, CTLFLAG_TUN|CTLFLAG_RD, 270 &pmc_mtxpool_size, 0, "size of spin mutex pool"); 271 272 273 /* 274 * security.bsd.unprivileged_syspmcs -- allow non-root processes to 275 * allocate system-wide PMCs. 276 * 277 * Allowing unprivileged processes to allocate system PMCs is convenient 278 * if system-wide measurements need to be taken concurrently with other 279 * per-process measurements. This feature is turned off by default. 280 */ 281 282 static int pmc_unprivileged_syspmcs = 0; 283 TUNABLE_INT("security.bsd.unprivileged_syspmcs", &pmc_unprivileged_syspmcs); 284 SYSCTL_INT(_security_bsd, OID_AUTO, unprivileged_syspmcs, CTLFLAG_RW, 285 &pmc_unprivileged_syspmcs, 0, 286 "allow unprivileged process to allocate system PMCs"); 287 288 /* 289 * Hash function. Discard the lower 2 bits of the pointer since 290 * these are always zero for our uses. The hash multiplier is 291 * round((2^LONG_BIT) * ((sqrt(5)-1)/2)). 292 */ 293 294 #if LONG_BIT == 64 295 #define _PMC_HM 11400714819323198486u 296 #elif LONG_BIT == 32 297 #define _PMC_HM 2654435769u 298 #else 299 #error Must know the size of 'long' to compile 300 #endif 301 302 #define PMC_HASH_PTR(P,M) ((((unsigned long) (P) >> 2) * _PMC_HM) & (M)) 303 304 /* 305 * Syscall structures 306 */ 307 308 /* The `sysent' for the new syscall */ 309 static struct sysent pmc_sysent = { 310 2, /* sy_narg */ 311 pmc_syscall_handler /* sy_call */ 312 }; 313 314 static struct syscall_module_data pmc_syscall_mod = { 315 load, 316 NULL, 317 &pmc_syscall_num, 318 &pmc_sysent, 319 { 0, NULL } 320 }; 321 322 static moduledata_t pmc_mod = { 323 PMC_MODULE_NAME, 324 syscall_module_handler, 325 &pmc_syscall_mod 326 }; 327 328 DECLARE_MODULE(pmc, pmc_mod, SI_SUB_SMP, SI_ORDER_ANY); 329 MODULE_VERSION(pmc, PMC_VERSION); 330 331 #ifdef DEBUG 332 enum pmc_dbgparse_state { 333 PMCDS_WS, /* in whitespace */ 334 PMCDS_MAJOR, /* seen a major keyword */ 335 PMCDS_MINOR 336 }; 337 338 static int 339 pmc_debugflags_parse(char *newstr, char *fence) 340 { 341 char c, *p, *q; 342 struct pmc_debugflags *tmpflags; 343 int error, found, *newbits, tmp; 344 size_t kwlen; 345 346 tmpflags = malloc(sizeof(*tmpflags), M_PMC, M_WAITOK|M_ZERO); 347 348 p = newstr; 349 error = 0; 350 351 for (; p < fence && (c = *p); p++) { 352 353 /* skip white space */ 354 if (c == ' ' || c == '\t') 355 continue; 356 357 /* look for a keyword followed by "=" */ 358 for (q = p; p < fence && (c = *p) && c != '='; p++) 359 ; 360 if (c != '=') { 361 error = EINVAL; 362 goto done; 363 } 364 365 kwlen = p - q; 366 newbits = NULL; 367 368 /* lookup flag group name */ 369 #define DBG_SET_FLAG_MAJ(S,F) \ 370 if (kwlen == sizeof(S)-1 && strncmp(q, S, kwlen) == 0) \ 371 newbits = &tmpflags->pdb_ ## F; 372 373 DBG_SET_FLAG_MAJ("cpu", CPU); 374 DBG_SET_FLAG_MAJ("csw", CSW); 375 DBG_SET_FLAG_MAJ("logging", LOG); 376 DBG_SET_FLAG_MAJ("module", MOD); 377 DBG_SET_FLAG_MAJ("md", MDP); 378 DBG_SET_FLAG_MAJ("owner", OWN); 379 DBG_SET_FLAG_MAJ("pmc", PMC); 380 DBG_SET_FLAG_MAJ("process", PRC); 381 DBG_SET_FLAG_MAJ("sampling", SAM); 382 383 if (newbits == NULL) { 384 error = EINVAL; 385 goto done; 386 } 387 388 p++; /* skip the '=' */ 389 390 /* Now parse the individual flags */ 391 tmp = 0; 392 newflag: 393 for (q = p; p < fence && (c = *p); p++) 394 if (c == ' ' || c == '\t' || c == ',') 395 break; 396 397 /* p == fence or c == ws or c == "," or c == 0 */ 398 399 if ((kwlen = p - q) == 0) { 400 *newbits = tmp; 401 continue; 402 } 403 404 found = 0; 405 #define DBG_SET_FLAG_MIN(S,F) \ 406 if (kwlen == sizeof(S)-1 && strncmp(q, S, kwlen) == 0) \ 407 tmp |= found = (1 << PMC_DEBUG_MIN_ ## F) 408 409 /* a '*' denotes all possible flags in the group */ 410 if (kwlen == 1 && *q == '*') 411 tmp = found = ~0; 412 /* look for individual flag names */ 413 DBG_SET_FLAG_MIN("allocaterow", ALR); 414 DBG_SET_FLAG_MIN("allocate", ALL); 415 DBG_SET_FLAG_MIN("attach", ATT); 416 DBG_SET_FLAG_MIN("bind", BND); 417 DBG_SET_FLAG_MIN("config", CFG); 418 DBG_SET_FLAG_MIN("exec", EXC); 419 DBG_SET_FLAG_MIN("exit", EXT); 420 DBG_SET_FLAG_MIN("find", FND); 421 DBG_SET_FLAG_MIN("flush", FLS); 422 DBG_SET_FLAG_MIN("fork", FRK); 423 DBG_SET_FLAG_MIN("getbuf", GTB); 424 DBG_SET_FLAG_MIN("hook", PMH); 425 DBG_SET_FLAG_MIN("init", INI); 426 DBG_SET_FLAG_MIN("intr", INT); 427 DBG_SET_FLAG_MIN("linktarget", TLK); 428 DBG_SET_FLAG_MIN("mayberemove", OMR); 429 DBG_SET_FLAG_MIN("ops", OPS); 430 DBG_SET_FLAG_MIN("read", REA); 431 DBG_SET_FLAG_MIN("register", REG); 432 DBG_SET_FLAG_MIN("release", REL); 433 DBG_SET_FLAG_MIN("remove", ORM); 434 DBG_SET_FLAG_MIN("sample", SAM); 435 DBG_SET_FLAG_MIN("scheduleio", SIO); 436 DBG_SET_FLAG_MIN("select", SEL); 437 DBG_SET_FLAG_MIN("signal", SIG); 438 DBG_SET_FLAG_MIN("swi", SWI); 439 DBG_SET_FLAG_MIN("swo", SWO); 440 DBG_SET_FLAG_MIN("start", STA); 441 DBG_SET_FLAG_MIN("stop", STO); 442 DBG_SET_FLAG_MIN("syscall", PMS); 443 DBG_SET_FLAG_MIN("unlinktarget", TUL); 444 DBG_SET_FLAG_MIN("write", WRI); 445 if (found == 0) { 446 /* unrecognized flag name */ 447 error = EINVAL; 448 goto done; 449 } 450 451 if (c == 0 || c == ' ' || c == '\t') { /* end of flag group */ 452 *newbits = tmp; 453 continue; 454 } 455 456 p++; 457 goto newflag; 458 } 459 460 /* save the new flag set */ 461 bcopy(tmpflags, &pmc_debugflags, sizeof(pmc_debugflags)); 462 463 done: 464 free(tmpflags, M_PMC); 465 return error; 466 } 467 468 static int 469 pmc_debugflags_sysctl_handler(SYSCTL_HANDLER_ARGS) 470 { 471 char *fence, *newstr; 472 int error; 473 unsigned int n; 474 475 (void) arg1; (void) arg2; /* unused parameters */ 476 477 n = sizeof(pmc_debugstr); 478 newstr = malloc(n, M_PMC, M_WAITOK|M_ZERO); 479 (void) strlcpy(newstr, pmc_debugstr, n); 480 481 error = sysctl_handle_string(oidp, newstr, n, req); 482 483 /* if there is a new string, parse and copy it */ 484 if (error == 0 && req->newptr != NULL) { 485 fence = newstr + (n < req->newlen ? n : req->newlen + 1); 486 if ((error = pmc_debugflags_parse(newstr, fence)) == 0) 487 (void) strlcpy(pmc_debugstr, newstr, 488 sizeof(pmc_debugstr)); 489 } 490 491 free(newstr, M_PMC); 492 493 return error; 494 } 495 #endif 496 497 /* 498 * Map a row index to a classdep structure and return the adjusted row 499 * index for the PMC class index. 500 */ 501 static struct pmc_classdep * 502 pmc_ri_to_classdep(struct pmc_mdep *md, int ri, int *adjri) 503 { 504 struct pmc_classdep *pcd; 505 506 (void) md; 507 508 KASSERT(ri >= 0 && ri < md->pmd_npmc, 509 ("[pmc,%d] illegal row-index %d", __LINE__, ri)); 510 511 pcd = pmc_rowindex_to_classdep[ri]; 512 513 KASSERT(pcd != NULL, 514 ("[pmc,%d] ri %d null pcd", __LINE__, ri)); 515 516 *adjri = ri - pcd->pcd_ri; 517 518 KASSERT(*adjri >= 0 && *adjri < pcd->pcd_num, 519 ("[pmc,%d] adjusted row-index %d", __LINE__, *adjri)); 520 521 return (pcd); 522 } 523 524 /* 525 * Concurrency Control 526 * 527 * The driver manages the following data structures: 528 * 529 * - target process descriptors, one per target process 530 * - owner process descriptors (and attached lists), one per owner process 531 * - lookup hash tables for owner and target processes 532 * - PMC descriptors (and attached lists) 533 * - per-cpu hardware state 534 * - the 'hook' variable through which the kernel calls into 535 * this module 536 * - the machine hardware state (managed by the MD layer) 537 * 538 * These data structures are accessed from: 539 * 540 * - thread context-switch code 541 * - interrupt handlers (possibly on multiple cpus) 542 * - kernel threads on multiple cpus running on behalf of user 543 * processes doing system calls 544 * - this driver's private kernel threads 545 * 546 * = Locks and Locking strategy = 547 * 548 * The driver uses four locking strategies for its operation: 549 * 550 * - The global SX lock "pmc_sx" is used to protect internal 551 * data structures. 552 * 553 * Calls into the module by syscall() start with this lock being 554 * held in exclusive mode. Depending on the requested operation, 555 * the lock may be downgraded to 'shared' mode to allow more 556 * concurrent readers into the module. Calls into the module from 557 * other parts of the kernel acquire the lock in shared mode. 558 * 559 * This SX lock is held in exclusive mode for any operations that 560 * modify the linkages between the driver's internal data structures. 561 * 562 * The 'pmc_hook' function pointer is also protected by this lock. 563 * It is only examined with the sx lock held in exclusive mode. The 564 * kernel module is allowed to be unloaded only with the sx lock held 565 * in exclusive mode. In normal syscall handling, after acquiring the 566 * pmc_sx lock we first check that 'pmc_hook' is non-null before 567 * proceeding. This prevents races between the thread unloading the module 568 * and other threads seeking to use the module. 569 * 570 * - Lookups of target process structures and owner process structures 571 * cannot use the global "pmc_sx" SX lock because these lookups need 572 * to happen during context switches and in other critical sections 573 * where sleeping is not allowed. We protect these lookup tables 574 * with their own private spin-mutexes, "pmc_processhash_mtx" and 575 * "pmc_ownerhash_mtx". 576 * 577 * - Interrupt handlers work in a lock free manner. At interrupt 578 * time, handlers look at the PMC pointer (phw->phw_pmc) configured 579 * when the PMC was started. If this pointer is NULL, the interrupt 580 * is ignored after updating driver statistics. We ensure that this 581 * pointer is set (using an atomic operation if necessary) before the 582 * PMC hardware is started. Conversely, this pointer is unset atomically 583 * only after the PMC hardware is stopped. 584 * 585 * We ensure that everything needed for the operation of an 586 * interrupt handler is available without it needing to acquire any 587 * locks. We also ensure that a PMC's software state is destroyed only 588 * after the PMC is taken off hardware (on all CPUs). 589 * 590 * - Context-switch handling with process-private PMCs needs more 591 * care. 592 * 593 * A given process may be the target of multiple PMCs. For example, 594 * PMCATTACH and PMCDETACH may be requested by a process on one CPU 595 * while the target process is running on another. A PMC could also 596 * be getting released because its owner is exiting. We tackle 597 * these situations in the following manner: 598 * 599 * - each target process structure 'pmc_process' has an array 600 * of 'struct pmc *' pointers, one for each hardware PMC. 601 * 602 * - At context switch IN time, each "target" PMC in RUNNING state 603 * gets started on hardware and a pointer to each PMC is copied into 604 * the per-cpu phw array. The 'runcount' for the PMC is 605 * incremented. 606 * 607 * - At context switch OUT time, all process-virtual PMCs are stopped 608 * on hardware. The saved value is added to the PMCs value field 609 * only if the PMC is in a non-deleted state (the PMCs state could 610 * have changed during the current time slice). 611 * 612 * Note that since in-between a switch IN on a processor and a switch 613 * OUT, the PMC could have been released on another CPU. Therefore 614 * context switch OUT always looks at the hardware state to turn 615 * OFF PMCs and will update a PMC's saved value only if reachable 616 * from the target process record. 617 * 618 * - OP PMCRELEASE could be called on a PMC at any time (the PMC could 619 * be attached to many processes at the time of the call and could 620 * be active on multiple CPUs). 621 * 622 * We prevent further scheduling of the PMC by marking it as in 623 * state 'DELETED'. If the runcount of the PMC is non-zero then 624 * this PMC is currently running on a CPU somewhere. The thread 625 * doing the PMCRELEASE operation waits by repeatedly doing a 626 * pause() till the runcount comes to zero. 627 * 628 * The contents of a PMC descriptor (struct pmc) are protected using 629 * a spin-mutex. In order to save space, we use a mutex pool. 630 * 631 * In terms of lock types used by witness(4), we use: 632 * - Type "pmc-sx", used by the global SX lock. 633 * - Type "pmc-sleep", for sleep mutexes used by logger threads. 634 * - Type "pmc-per-proc", for protecting PMC owner descriptors. 635 * - Type "pmc-leaf", used for all other spin mutexes. 636 */ 637 638 /* 639 * save the cpu binding of the current kthread 640 */ 641 642 static void 643 pmc_save_cpu_binding(struct pmc_binding *pb) 644 { 645 PMCDBG(CPU,BND,2, "%s", "save-cpu"); 646 thread_lock(curthread); 647 pb->pb_bound = sched_is_bound(curthread); 648 pb->pb_cpu = curthread->td_oncpu; 649 thread_unlock(curthread); 650 PMCDBG(CPU,BND,2, "save-cpu cpu=%d", pb->pb_cpu); 651 } 652 653 /* 654 * restore the cpu binding of the current thread 655 */ 656 657 static void 658 pmc_restore_cpu_binding(struct pmc_binding *pb) 659 { 660 PMCDBG(CPU,BND,2, "restore-cpu curcpu=%d restore=%d", 661 curthread->td_oncpu, pb->pb_cpu); 662 thread_lock(curthread); 663 if (pb->pb_bound) 664 sched_bind(curthread, pb->pb_cpu); 665 else 666 sched_unbind(curthread); 667 thread_unlock(curthread); 668 PMCDBG(CPU,BND,2, "%s", "restore-cpu done"); 669 } 670 671 /* 672 * move execution over the specified cpu and bind it there. 673 */ 674 675 static void 676 pmc_select_cpu(int cpu) 677 { 678 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 679 ("[pmc,%d] bad cpu number %d", __LINE__, cpu)); 680 681 /* Never move to an inactive CPU. */ 682 KASSERT(pmc_cpu_is_active(cpu), ("[pmc,%d] selecting inactive " 683 "CPU %d", __LINE__, cpu)); 684 685 PMCDBG(CPU,SEL,2, "select-cpu cpu=%d", cpu); 686 thread_lock(curthread); 687 sched_bind(curthread, cpu); 688 thread_unlock(curthread); 689 690 KASSERT(curthread->td_oncpu == cpu, 691 ("[pmc,%d] CPU not bound [cpu=%d, curr=%d]", __LINE__, 692 cpu, curthread->td_oncpu)); 693 694 PMCDBG(CPU,SEL,2, "select-cpu cpu=%d ok", cpu); 695 } 696 697 /* 698 * Force a context switch. 699 * 700 * We do this by pause'ing for 1 tick -- invoking mi_switch() is not 701 * guaranteed to force a context switch. 702 */ 703 704 static void 705 pmc_force_context_switch(void) 706 { 707 708 pause("pmcctx", 1); 709 } 710 711 /* 712 * Get the file name for an executable. This is a simple wrapper 713 * around vn_fullpath(9). 714 */ 715 716 static void 717 pmc_getfilename(struct vnode *v, char **fullpath, char **freepath) 718 { 719 720 *fullpath = "unknown"; 721 *freepath = NULL; 722 vn_fullpath(curthread, v, fullpath, freepath); 723 } 724 725 /* 726 * remove an process owning PMCs 727 */ 728 729 void 730 pmc_remove_owner(struct pmc_owner *po) 731 { 732 struct pmc *pm, *tmp; 733 734 sx_assert(&pmc_sx, SX_XLOCKED); 735 736 PMCDBG(OWN,ORM,1, "remove-owner po=%p", po); 737 738 /* Remove descriptor from the owner hash table */ 739 LIST_REMOVE(po, po_next); 740 741 /* release all owned PMC descriptors */ 742 LIST_FOREACH_SAFE(pm, &po->po_pmcs, pm_next, tmp) { 743 PMCDBG(OWN,ORM,2, "pmc=%p", pm); 744 KASSERT(pm->pm_owner == po, 745 ("[pmc,%d] owner %p != po %p", __LINE__, pm->pm_owner, po)); 746 747 pmc_release_pmc_descriptor(pm); /* will unlink from the list */ 748 } 749 750 KASSERT(po->po_sscount == 0, 751 ("[pmc,%d] SS count not zero", __LINE__)); 752 KASSERT(LIST_EMPTY(&po->po_pmcs), 753 ("[pmc,%d] PMC list not empty", __LINE__)); 754 755 /* de-configure the log file if present */ 756 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 757 pmclog_deconfigure_log(po); 758 } 759 760 /* 761 * remove an owner process record if all conditions are met. 762 */ 763 764 static void 765 pmc_maybe_remove_owner(struct pmc_owner *po) 766 { 767 768 PMCDBG(OWN,OMR,1, "maybe-remove-owner po=%p", po); 769 770 /* 771 * Remove owner record if 772 * - this process does not own any PMCs 773 * - this process has not allocated a system-wide sampling buffer 774 */ 775 776 if (LIST_EMPTY(&po->po_pmcs) && 777 ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0)) { 778 pmc_remove_owner(po); 779 pmc_destroy_owner_descriptor(po); 780 } 781 } 782 783 /* 784 * Add an association between a target process and a PMC. 785 */ 786 787 static void 788 pmc_link_target_process(struct pmc *pm, struct pmc_process *pp) 789 { 790 int ri; 791 struct pmc_target *pt; 792 793 sx_assert(&pmc_sx, SX_XLOCKED); 794 795 KASSERT(pm != NULL && pp != NULL, 796 ("[pmc,%d] Null pm %p or pp %p", __LINE__, pm, pp)); 797 KASSERT(PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)), 798 ("[pmc,%d] Attaching a non-process-virtual pmc=%p to pid=%d", 799 __LINE__, pm, pp->pp_proc->p_pid)); 800 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= ((int) md->pmd_npmc - 1), 801 ("[pmc,%d] Illegal reference count %d for process record %p", 802 __LINE__, pp->pp_refcnt, (void *) pp)); 803 804 ri = PMC_TO_ROWINDEX(pm); 805 806 PMCDBG(PRC,TLK,1, "link-target pmc=%p ri=%d pmc-process=%p", 807 pm, ri, pp); 808 809 #ifdef DEBUG 810 LIST_FOREACH(pt, &pm->pm_targets, pt_next) 811 if (pt->pt_process == pp) 812 KASSERT(0, ("[pmc,%d] pp %p already in pmc %p targets", 813 __LINE__, pp, pm)); 814 #endif 815 816 pt = malloc(sizeof(struct pmc_target), M_PMC, M_WAITOK|M_ZERO); 817 pt->pt_process = pp; 818 819 LIST_INSERT_HEAD(&pm->pm_targets, pt, pt_next); 820 821 atomic_store_rel_ptr((uintptr_t *)&pp->pp_pmcs[ri].pp_pmc, 822 (uintptr_t)pm); 823 824 if (pm->pm_owner->po_owner == pp->pp_proc) 825 pm->pm_flags |= PMC_F_ATTACHED_TO_OWNER; 826 827 /* 828 * Initialize the per-process values at this row index. 829 */ 830 pp->pp_pmcs[ri].pp_pmcval = PMC_TO_MODE(pm) == PMC_MODE_TS ? 831 pm->pm_sc.pm_reloadcount : 0; 832 833 pp->pp_refcnt++; 834 835 } 836 837 /* 838 * Removes the association between a target process and a PMC. 839 */ 840 841 static void 842 pmc_unlink_target_process(struct pmc *pm, struct pmc_process *pp) 843 { 844 int ri; 845 struct proc *p; 846 struct pmc_target *ptgt; 847 848 sx_assert(&pmc_sx, SX_XLOCKED); 849 850 KASSERT(pm != NULL && pp != NULL, 851 ("[pmc,%d] Null pm %p or pp %p", __LINE__, pm, pp)); 852 853 KASSERT(pp->pp_refcnt >= 1 && pp->pp_refcnt <= (int) md->pmd_npmc, 854 ("[pmc,%d] Illegal ref count %d on process record %p", 855 __LINE__, pp->pp_refcnt, (void *) pp)); 856 857 ri = PMC_TO_ROWINDEX(pm); 858 859 PMCDBG(PRC,TUL,1, "unlink-target pmc=%p ri=%d pmc-process=%p", 860 pm, ri, pp); 861 862 KASSERT(pp->pp_pmcs[ri].pp_pmc == pm, 863 ("[pmc,%d] PMC ri %d mismatch pmc %p pp->[ri] %p", __LINE__, 864 ri, pm, pp->pp_pmcs[ri].pp_pmc)); 865 866 pp->pp_pmcs[ri].pp_pmc = NULL; 867 pp->pp_pmcs[ri].pp_pmcval = (pmc_value_t) 0; 868 869 /* Remove owner-specific flags */ 870 if (pm->pm_owner->po_owner == pp->pp_proc) { 871 pp->pp_flags &= ~PMC_PP_ENABLE_MSR_ACCESS; 872 pm->pm_flags &= ~PMC_F_ATTACHED_TO_OWNER; 873 } 874 875 pp->pp_refcnt--; 876 877 /* Remove the target process from the PMC structure */ 878 LIST_FOREACH(ptgt, &pm->pm_targets, pt_next) 879 if (ptgt->pt_process == pp) 880 break; 881 882 KASSERT(ptgt != NULL, ("[pmc,%d] process %p (pp: %p) not found " 883 "in pmc %p", __LINE__, pp->pp_proc, pp, pm)); 884 885 LIST_REMOVE(ptgt, pt_next); 886 free(ptgt, M_PMC); 887 888 /* if the PMC now lacks targets, send the owner a SIGIO */ 889 if (LIST_EMPTY(&pm->pm_targets)) { 890 p = pm->pm_owner->po_owner; 891 PROC_LOCK(p); 892 psignal(p, SIGIO); 893 PROC_UNLOCK(p); 894 895 PMCDBG(PRC,SIG,2, "signalling proc=%p signal=%d", p, 896 SIGIO); 897 } 898 } 899 900 /* 901 * Check if PMC 'pm' may be attached to target process 't'. 902 */ 903 904 static int 905 pmc_can_attach(struct pmc *pm, struct proc *t) 906 { 907 struct proc *o; /* pmc owner */ 908 struct ucred *oc, *tc; /* owner, target credentials */ 909 int decline_attach, i; 910 911 /* 912 * A PMC's owner can always attach that PMC to itself. 913 */ 914 915 if ((o = pm->pm_owner->po_owner) == t) 916 return 0; 917 918 PROC_LOCK(o); 919 oc = o->p_ucred; 920 crhold(oc); 921 PROC_UNLOCK(o); 922 923 PROC_LOCK(t); 924 tc = t->p_ucred; 925 crhold(tc); 926 PROC_UNLOCK(t); 927 928 /* 929 * The effective uid of the PMC owner should match at least one 930 * of the {effective,real,saved} uids of the target process. 931 */ 932 933 decline_attach = oc->cr_uid != tc->cr_uid && 934 oc->cr_uid != tc->cr_svuid && 935 oc->cr_uid != tc->cr_ruid; 936 937 /* 938 * Every one of the target's group ids, must be in the owner's 939 * group list. 940 */ 941 for (i = 0; !decline_attach && i < tc->cr_ngroups; i++) 942 decline_attach = !groupmember(tc->cr_groups[i], oc); 943 944 /* check the read and saved gids too */ 945 if (decline_attach == 0) 946 decline_attach = !groupmember(tc->cr_rgid, oc) || 947 !groupmember(tc->cr_svgid, oc); 948 949 crfree(tc); 950 crfree(oc); 951 952 return !decline_attach; 953 } 954 955 /* 956 * Attach a process to a PMC. 957 */ 958 959 static int 960 pmc_attach_one_process(struct proc *p, struct pmc *pm) 961 { 962 int ri; 963 char *fullpath, *freepath; 964 struct pmc_process *pp; 965 966 sx_assert(&pmc_sx, SX_XLOCKED); 967 968 PMCDBG(PRC,ATT,2, "attach-one pm=%p ri=%d proc=%p (%d, %s)", pm, 969 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 970 971 /* 972 * Locate the process descriptor corresponding to process 'p', 973 * allocating space as needed. 974 * 975 * Verify that rowindex 'pm_rowindex' is free in the process 976 * descriptor. 977 * 978 * If not, allocate space for a descriptor and link the 979 * process descriptor and PMC. 980 */ 981 ri = PMC_TO_ROWINDEX(pm); 982 983 if ((pp = pmc_find_process_descriptor(p, PMC_FLAG_ALLOCATE)) == NULL) 984 return ENOMEM; 985 986 if (pp->pp_pmcs[ri].pp_pmc == pm) /* already present at slot [ri] */ 987 return EEXIST; 988 989 if (pp->pp_pmcs[ri].pp_pmc != NULL) 990 return EBUSY; 991 992 pmc_link_target_process(pm, pp); 993 994 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)) && 995 (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) == 0) 996 pm->pm_flags |= PMC_F_NEEDS_LOGFILE; 997 998 pm->pm_flags |= PMC_F_ATTACH_DONE; /* mark as attached */ 999 1000 /* issue an attach event to a configured log file */ 1001 if (pm->pm_owner->po_flags & PMC_PO_OWNS_LOGFILE) { 1002 pmc_getfilename(p->p_textvp, &fullpath, &freepath); 1003 if (p->p_flag & P_KTHREAD) { 1004 fullpath = kernelname; 1005 freepath = NULL; 1006 } else 1007 pmclog_process_pmcattach(pm, p->p_pid, fullpath); 1008 if (freepath) 1009 free(freepath, M_TEMP); 1010 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 1011 pmc_log_process_mappings(pm->pm_owner, p); 1012 } 1013 /* mark process as using HWPMCs */ 1014 PROC_LOCK(p); 1015 p->p_flag |= P_HWPMC; 1016 PROC_UNLOCK(p); 1017 1018 return 0; 1019 } 1020 1021 /* 1022 * Attach a process and optionally its children 1023 */ 1024 1025 static int 1026 pmc_attach_process(struct proc *p, struct pmc *pm) 1027 { 1028 int error; 1029 struct proc *top; 1030 1031 sx_assert(&pmc_sx, SX_XLOCKED); 1032 1033 PMCDBG(PRC,ATT,1, "attach pm=%p ri=%d proc=%p (%d, %s)", pm, 1034 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 1035 1036 1037 /* 1038 * If this PMC successfully allowed a GETMSR operation 1039 * in the past, disallow further ATTACHes. 1040 */ 1041 1042 if ((pm->pm_flags & PMC_PP_ENABLE_MSR_ACCESS) != 0) 1043 return EPERM; 1044 1045 if ((pm->pm_flags & PMC_F_DESCENDANTS) == 0) 1046 return pmc_attach_one_process(p, pm); 1047 1048 /* 1049 * Traverse all child processes, attaching them to 1050 * this PMC. 1051 */ 1052 1053 sx_slock(&proctree_lock); 1054 1055 top = p; 1056 1057 for (;;) { 1058 if ((error = pmc_attach_one_process(p, pm)) != 0) 1059 break; 1060 if (!LIST_EMPTY(&p->p_children)) 1061 p = LIST_FIRST(&p->p_children); 1062 else for (;;) { 1063 if (p == top) 1064 goto done; 1065 if (LIST_NEXT(p, p_sibling)) { 1066 p = LIST_NEXT(p, p_sibling); 1067 break; 1068 } 1069 p = p->p_pptr; 1070 } 1071 } 1072 1073 if (error) 1074 (void) pmc_detach_process(top, pm); 1075 1076 done: 1077 sx_sunlock(&proctree_lock); 1078 return error; 1079 } 1080 1081 /* 1082 * Detach a process from a PMC. If there are no other PMCs tracking 1083 * this process, remove the process structure from its hash table. If 1084 * 'flags' contains PMC_FLAG_REMOVE, then free the process structure. 1085 */ 1086 1087 static int 1088 pmc_detach_one_process(struct proc *p, struct pmc *pm, int flags) 1089 { 1090 int ri; 1091 struct pmc_process *pp; 1092 1093 sx_assert(&pmc_sx, SX_XLOCKED); 1094 1095 KASSERT(pm != NULL, 1096 ("[pmc,%d] null pm pointer", __LINE__)); 1097 1098 ri = PMC_TO_ROWINDEX(pm); 1099 1100 PMCDBG(PRC,ATT,2, "detach-one pm=%p ri=%d proc=%p (%d, %s) flags=0x%x", 1101 pm, ri, p, p->p_pid, p->p_comm, flags); 1102 1103 if ((pp = pmc_find_process_descriptor(p, 0)) == NULL) 1104 return ESRCH; 1105 1106 if (pp->pp_pmcs[ri].pp_pmc != pm) 1107 return EINVAL; 1108 1109 pmc_unlink_target_process(pm, pp); 1110 1111 /* Issue a detach entry if a log file is configured */ 1112 if (pm->pm_owner->po_flags & PMC_PO_OWNS_LOGFILE) 1113 pmclog_process_pmcdetach(pm, p->p_pid); 1114 1115 /* 1116 * If there are no PMCs targetting this process, we remove its 1117 * descriptor from the target hash table and unset the P_HWPMC 1118 * flag in the struct proc. 1119 */ 1120 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= (int) md->pmd_npmc, 1121 ("[pmc,%d] Illegal refcnt %d for process struct %p", 1122 __LINE__, pp->pp_refcnt, pp)); 1123 1124 if (pp->pp_refcnt != 0) /* still a target of some PMC */ 1125 return 0; 1126 1127 pmc_remove_process_descriptor(pp); 1128 1129 if (flags & PMC_FLAG_REMOVE) 1130 free(pp, M_PMC); 1131 1132 PROC_LOCK(p); 1133 p->p_flag &= ~P_HWPMC; 1134 PROC_UNLOCK(p); 1135 1136 return 0; 1137 } 1138 1139 /* 1140 * Detach a process and optionally its descendants from a PMC. 1141 */ 1142 1143 static int 1144 pmc_detach_process(struct proc *p, struct pmc *pm) 1145 { 1146 struct proc *top; 1147 1148 sx_assert(&pmc_sx, SX_XLOCKED); 1149 1150 PMCDBG(PRC,ATT,1, "detach pm=%p ri=%d proc=%p (%d, %s)", pm, 1151 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 1152 1153 if ((pm->pm_flags & PMC_F_DESCENDANTS) == 0) 1154 return pmc_detach_one_process(p, pm, PMC_FLAG_REMOVE); 1155 1156 /* 1157 * Traverse all children, detaching them from this PMC. We 1158 * ignore errors since we could be detaching a PMC from a 1159 * partially attached proc tree. 1160 */ 1161 1162 sx_slock(&proctree_lock); 1163 1164 top = p; 1165 1166 for (;;) { 1167 (void) pmc_detach_one_process(p, pm, PMC_FLAG_REMOVE); 1168 1169 if (!LIST_EMPTY(&p->p_children)) 1170 p = LIST_FIRST(&p->p_children); 1171 else for (;;) { 1172 if (p == top) 1173 goto done; 1174 if (LIST_NEXT(p, p_sibling)) { 1175 p = LIST_NEXT(p, p_sibling); 1176 break; 1177 } 1178 p = p->p_pptr; 1179 } 1180 } 1181 1182 done: 1183 sx_sunlock(&proctree_lock); 1184 1185 if (LIST_EMPTY(&pm->pm_targets)) 1186 pm->pm_flags &= ~PMC_F_ATTACH_DONE; 1187 1188 return 0; 1189 } 1190 1191 1192 /* 1193 * Thread context switch IN 1194 */ 1195 1196 static void 1197 pmc_process_csw_in(struct thread *td) 1198 { 1199 int cpu; 1200 unsigned int adjri, ri; 1201 struct pmc *pm; 1202 struct proc *p; 1203 struct pmc_cpu *pc; 1204 struct pmc_hw *phw; 1205 pmc_value_t newvalue; 1206 struct pmc_process *pp; 1207 struct pmc_classdep *pcd; 1208 1209 p = td->td_proc; 1210 1211 if ((pp = pmc_find_process_descriptor(p, PMC_FLAG_NONE)) == NULL) 1212 return; 1213 1214 KASSERT(pp->pp_proc == td->td_proc, 1215 ("[pmc,%d] not my thread state", __LINE__)); 1216 1217 critical_enter(); /* no preemption from this point */ 1218 1219 cpu = PCPU_GET(cpuid); /* td->td_oncpu is invalid */ 1220 1221 PMCDBG(CSW,SWI,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p, 1222 p->p_pid, p->p_comm, pp); 1223 1224 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 1225 ("[pmc,%d] wierd CPU id %d", __LINE__, cpu)); 1226 1227 pc = pmc_pcpu[cpu]; 1228 1229 for (ri = 0; ri < md->pmd_npmc; ri++) { 1230 1231 if ((pm = pp->pp_pmcs[ri].pp_pmc) == NULL) 1232 continue; 1233 1234 KASSERT(PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)), 1235 ("[pmc,%d] Target PMC in non-virtual mode (%d)", 1236 __LINE__, PMC_TO_MODE(pm))); 1237 1238 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 1239 ("[pmc,%d] Row index mismatch pmc %d != ri %d", 1240 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 1241 1242 /* 1243 * Only PMCs that are marked as 'RUNNING' need 1244 * be placed on hardware. 1245 */ 1246 1247 if (pm->pm_state != PMC_STATE_RUNNING) 1248 continue; 1249 1250 /* increment PMC runcount */ 1251 atomic_add_rel_32(&pm->pm_runcount, 1); 1252 1253 /* configure the HWPMC we are going to use. */ 1254 pcd = pmc_ri_to_classdep(md, ri, &adjri); 1255 pcd->pcd_config_pmc(cpu, adjri, pm); 1256 1257 phw = pc->pc_hwpmcs[ri]; 1258 1259 KASSERT(phw != NULL, 1260 ("[pmc,%d] null hw pointer", __LINE__)); 1261 1262 KASSERT(phw->phw_pmc == pm, 1263 ("[pmc,%d] hw->pmc %p != pmc %p", __LINE__, 1264 phw->phw_pmc, pm)); 1265 1266 /* 1267 * Write out saved value and start the PMC. 1268 * 1269 * Sampling PMCs use a per-process value, while 1270 * counting mode PMCs use a per-pmc value that is 1271 * inherited across descendants. 1272 */ 1273 if (PMC_TO_MODE(pm) == PMC_MODE_TS) { 1274 mtx_pool_lock_spin(pmc_mtxpool, pm); 1275 newvalue = PMC_PCPU_SAVED(cpu,ri) = 1276 pp->pp_pmcs[ri].pp_pmcval; 1277 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1278 } else { 1279 KASSERT(PMC_TO_MODE(pm) == PMC_MODE_TC, 1280 ("[pmc,%d] illegal mode=%d", __LINE__, 1281 PMC_TO_MODE(pm))); 1282 mtx_pool_lock_spin(pmc_mtxpool, pm); 1283 newvalue = PMC_PCPU_SAVED(cpu, ri) = 1284 pm->pm_gv.pm_savedvalue; 1285 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1286 } 1287 1288 PMCDBG(CSW,SWI,1,"cpu=%d ri=%d new=%jd", cpu, ri, newvalue); 1289 1290 pcd->pcd_write_pmc(cpu, adjri, newvalue); 1291 pcd->pcd_start_pmc(cpu, adjri); 1292 } 1293 1294 /* 1295 * perform any other architecture/cpu dependent thread 1296 * switch-in actions. 1297 */ 1298 1299 (void) (*md->pmd_switch_in)(pc, pp); 1300 1301 critical_exit(); 1302 1303 } 1304 1305 /* 1306 * Thread context switch OUT. 1307 */ 1308 1309 static void 1310 pmc_process_csw_out(struct thread *td) 1311 { 1312 int cpu; 1313 int64_t tmp; 1314 struct pmc *pm; 1315 struct proc *p; 1316 enum pmc_mode mode; 1317 struct pmc_cpu *pc; 1318 pmc_value_t newvalue; 1319 unsigned int adjri, ri; 1320 struct pmc_process *pp; 1321 struct pmc_classdep *pcd; 1322 1323 1324 /* 1325 * Locate our process descriptor; this may be NULL if 1326 * this process is exiting and we have already removed 1327 * the process from the target process table. 1328 * 1329 * Note that due to kernel preemption, multiple 1330 * context switches may happen while the process is 1331 * exiting. 1332 * 1333 * Note also that if the target process cannot be 1334 * found we still need to deconfigure any PMCs that 1335 * are currently running on hardware. 1336 */ 1337 1338 p = td->td_proc; 1339 pp = pmc_find_process_descriptor(p, PMC_FLAG_NONE); 1340 1341 /* 1342 * save PMCs 1343 */ 1344 1345 critical_enter(); 1346 1347 cpu = PCPU_GET(cpuid); /* td->td_oncpu is invalid */ 1348 1349 PMCDBG(CSW,SWO,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p, 1350 p->p_pid, p->p_comm, pp); 1351 1352 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 1353 ("[pmc,%d wierd CPU id %d", __LINE__, cpu)); 1354 1355 pc = pmc_pcpu[cpu]; 1356 1357 /* 1358 * When a PMC gets unlinked from a target PMC, it will 1359 * be removed from the target's pp_pmc[] array. 1360 * 1361 * However, on a MP system, the target could have been 1362 * executing on another CPU at the time of the unlink. 1363 * So, at context switch OUT time, we need to look at 1364 * the hardware to determine if a PMC is scheduled on 1365 * it. 1366 */ 1367 1368 for (ri = 0; ri < md->pmd_npmc; ri++) { 1369 1370 pcd = pmc_ri_to_classdep(md, ri, &adjri); 1371 pm = NULL; 1372 (void) (*pcd->pcd_get_config)(cpu, adjri, &pm); 1373 1374 if (pm == NULL) /* nothing at this row index */ 1375 continue; 1376 1377 mode = PMC_TO_MODE(pm); 1378 if (!PMC_IS_VIRTUAL_MODE(mode)) 1379 continue; /* not a process virtual PMC */ 1380 1381 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 1382 ("[pmc,%d] ri mismatch pmc(%d) ri(%d)", 1383 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 1384 1385 /* Stop hardware if not already stopped */ 1386 if (pm->pm_stalled == 0) 1387 pcd->pcd_stop_pmc(cpu, adjri); 1388 1389 /* reduce this PMC's runcount */ 1390 atomic_subtract_rel_32(&pm->pm_runcount, 1); 1391 1392 /* 1393 * If this PMC is associated with this process, 1394 * save the reading. 1395 */ 1396 1397 if (pp != NULL && pp->pp_pmcs[ri].pp_pmc != NULL) { 1398 1399 KASSERT(pm == pp->pp_pmcs[ri].pp_pmc, 1400 ("[pmc,%d] pm %p != pp_pmcs[%d] %p", __LINE__, 1401 pm, ri, pp->pp_pmcs[ri].pp_pmc)); 1402 1403 KASSERT(pp->pp_refcnt > 0, 1404 ("[pmc,%d] pp refcnt = %d", __LINE__, 1405 pp->pp_refcnt)); 1406 1407 pcd->pcd_read_pmc(cpu, adjri, &newvalue); 1408 1409 tmp = newvalue - PMC_PCPU_SAVED(cpu,ri); 1410 1411 PMCDBG(CSW,SWO,1,"cpu=%d ri=%d tmp=%jd", cpu, ri, 1412 tmp); 1413 1414 if (mode == PMC_MODE_TS) { 1415 1416 /* 1417 * For sampling process-virtual PMCs, 1418 * we expect the count to be 1419 * decreasing as the 'value' 1420 * programmed into the PMC is the 1421 * number of events to be seen till 1422 * the next sampling interrupt. 1423 */ 1424 if (tmp < 0) 1425 tmp += pm->pm_sc.pm_reloadcount; 1426 mtx_pool_lock_spin(pmc_mtxpool, pm); 1427 pp->pp_pmcs[ri].pp_pmcval -= tmp; 1428 if ((int64_t) pp->pp_pmcs[ri].pp_pmcval < 0) 1429 pp->pp_pmcs[ri].pp_pmcval += 1430 pm->pm_sc.pm_reloadcount; 1431 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1432 1433 } else { 1434 1435 /* 1436 * For counting process-virtual PMCs, 1437 * we expect the count to be 1438 * increasing monotonically, modulo a 64 1439 * bit wraparound. 1440 */ 1441 KASSERT((int64_t) tmp >= 0, 1442 ("[pmc,%d] negative increment cpu=%d " 1443 "ri=%d newvalue=%jx saved=%jx " 1444 "incr=%jx", __LINE__, cpu, ri, 1445 newvalue, PMC_PCPU_SAVED(cpu,ri), tmp)); 1446 1447 mtx_pool_lock_spin(pmc_mtxpool, pm); 1448 pm->pm_gv.pm_savedvalue += tmp; 1449 pp->pp_pmcs[ri].pp_pmcval += tmp; 1450 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1451 1452 if (pm->pm_flags & PMC_F_LOG_PROCCSW) 1453 pmclog_process_proccsw(pm, pp, tmp); 1454 } 1455 } 1456 1457 /* mark hardware as free */ 1458 pcd->pcd_config_pmc(cpu, adjri, NULL); 1459 } 1460 1461 /* 1462 * perform any other architecture/cpu dependent thread 1463 * switch out functions. 1464 */ 1465 1466 (void) (*md->pmd_switch_out)(pc, pp); 1467 1468 critical_exit(); 1469 } 1470 1471 /* 1472 * Log a KLD operation. 1473 */ 1474 1475 static void 1476 pmc_process_kld_load(struct pmckern_map_in *pkm) 1477 { 1478 struct pmc_owner *po; 1479 1480 sx_assert(&pmc_sx, SX_LOCKED); 1481 1482 /* 1483 * Notify owners of system sampling PMCs about KLD operations. 1484 */ 1485 1486 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1487 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1488 pmclog_process_map_in(po, (pid_t) -1, pkm->pm_address, 1489 (char *) pkm->pm_file); 1490 1491 /* 1492 * TODO: Notify owners of (all) process-sampling PMCs too. 1493 */ 1494 1495 return; 1496 } 1497 1498 static void 1499 pmc_process_kld_unload(struct pmckern_map_out *pkm) 1500 { 1501 struct pmc_owner *po; 1502 1503 sx_assert(&pmc_sx, SX_LOCKED); 1504 1505 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1506 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1507 pmclog_process_map_out(po, (pid_t) -1, 1508 pkm->pm_address, pkm->pm_address + pkm->pm_size); 1509 1510 /* 1511 * TODO: Notify owners of process-sampling PMCs. 1512 */ 1513 } 1514 1515 /* 1516 * A mapping change for a process. 1517 */ 1518 1519 static void 1520 pmc_process_mmap(struct thread *td, struct pmckern_map_in *pkm) 1521 { 1522 int ri; 1523 pid_t pid; 1524 char *fullpath, *freepath; 1525 const struct pmc *pm; 1526 struct pmc_owner *po; 1527 const struct pmc_process *pp; 1528 1529 freepath = fullpath = NULL; 1530 pmc_getfilename((struct vnode *) pkm->pm_file, &fullpath, &freepath); 1531 1532 pid = td->td_proc->p_pid; 1533 1534 /* Inform owners of all system-wide sampling PMCs. */ 1535 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1536 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1537 pmclog_process_map_in(po, pid, pkm->pm_address, fullpath); 1538 1539 if ((pp = pmc_find_process_descriptor(td->td_proc, 0)) == NULL) 1540 goto done; 1541 1542 /* 1543 * Inform sampling PMC owners tracking this process. 1544 */ 1545 for (ri = 0; ri < md->pmd_npmc; ri++) 1546 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL && 1547 PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 1548 pmclog_process_map_in(pm->pm_owner, 1549 pid, pkm->pm_address, fullpath); 1550 1551 done: 1552 if (freepath) 1553 free(freepath, M_TEMP); 1554 } 1555 1556 1557 /* 1558 * Log an munmap request. 1559 */ 1560 1561 static void 1562 pmc_process_munmap(struct thread *td, struct pmckern_map_out *pkm) 1563 { 1564 int ri; 1565 pid_t pid; 1566 struct pmc_owner *po; 1567 const struct pmc *pm; 1568 const struct pmc_process *pp; 1569 1570 pid = td->td_proc->p_pid; 1571 1572 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1573 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1574 pmclog_process_map_out(po, pid, pkm->pm_address, 1575 pkm->pm_address + pkm->pm_size); 1576 1577 if ((pp = pmc_find_process_descriptor(td->td_proc, 0)) == NULL) 1578 return; 1579 1580 for (ri = 0; ri < md->pmd_npmc; ri++) 1581 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL && 1582 PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 1583 pmclog_process_map_out(pm->pm_owner, pid, 1584 pkm->pm_address, pkm->pm_address + pkm->pm_size); 1585 } 1586 1587 /* 1588 * Log mapping information about the kernel. 1589 */ 1590 1591 static void 1592 pmc_log_kernel_mappings(struct pmc *pm) 1593 { 1594 struct pmc_owner *po; 1595 struct pmckern_map_in *km, *kmbase; 1596 1597 sx_assert(&pmc_sx, SX_LOCKED); 1598 KASSERT(PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)), 1599 ("[pmc,%d] non-sampling PMC (%p) desires mapping information", 1600 __LINE__, (void *) pm)); 1601 1602 po = pm->pm_owner; 1603 1604 if (po->po_flags & PMC_PO_INITIAL_MAPPINGS_DONE) 1605 return; 1606 1607 /* 1608 * Log the current set of kernel modules. 1609 */ 1610 kmbase = linker_hwpmc_list_objects(); 1611 for (km = kmbase; km->pm_file != NULL; km++) { 1612 PMCDBG(LOG,REG,1,"%s %p", (char *) km->pm_file, 1613 (void *) km->pm_address); 1614 pmclog_process_map_in(po, (pid_t) -1, km->pm_address, 1615 km->pm_file); 1616 } 1617 free(kmbase, M_LINKER); 1618 1619 po->po_flags |= PMC_PO_INITIAL_MAPPINGS_DONE; 1620 } 1621 1622 /* 1623 * Log the mappings for a single process. 1624 */ 1625 1626 static void 1627 pmc_log_process_mappings(struct pmc_owner *po, struct proc *p) 1628 { 1629 int locked; 1630 vm_map_t map; 1631 struct vnode *vp; 1632 struct vmspace *vm; 1633 vm_map_entry_t entry; 1634 vm_offset_t last_end; 1635 u_int last_timestamp; 1636 struct vnode *last_vp; 1637 vm_offset_t start_addr; 1638 vm_object_t obj, lobj, tobj; 1639 char *fullpath, *freepath; 1640 1641 last_vp = NULL; 1642 last_end = (vm_offset_t) 0; 1643 fullpath = freepath = NULL; 1644 1645 if ((vm = vmspace_acquire_ref(p)) == NULL) 1646 return; 1647 1648 map = &vm->vm_map; 1649 vm_map_lock_read(map); 1650 1651 for (entry = map->header.next; entry != &map->header; entry = entry->next) { 1652 1653 if (entry == NULL) { 1654 PMCDBG(LOG,OPS,2, "hwpmc: vm_map entry unexpectedly " 1655 "NULL! pid=%d vm_map=%p\n", p->p_pid, map); 1656 break; 1657 } 1658 1659 /* 1660 * We only care about executable map entries. 1661 */ 1662 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) || 1663 !(entry->protection & VM_PROT_EXECUTE) || 1664 (entry->object.vm_object == NULL)) { 1665 continue; 1666 } 1667 1668 obj = entry->object.vm_object; 1669 VM_OBJECT_LOCK(obj); 1670 1671 /* 1672 * Walk the backing_object list to find the base 1673 * (non-shadowed) vm_object. 1674 */ 1675 for (lobj = tobj = obj; tobj != NULL; tobj = tobj->backing_object) { 1676 if (tobj != obj) 1677 VM_OBJECT_LOCK(tobj); 1678 if (lobj != obj) 1679 VM_OBJECT_UNLOCK(lobj); 1680 lobj = tobj; 1681 } 1682 1683 /* 1684 * At this point lobj is the base vm_object and it is locked. 1685 */ 1686 if (lobj == NULL) { 1687 PMCDBG(LOG,OPS,2, "hwpmc: lobj unexpectedly NULL! pid=%d " 1688 "vm_map=%p vm_obj=%p\n", p->p_pid, map, obj); 1689 VM_OBJECT_UNLOCK(obj); 1690 continue; 1691 } 1692 1693 if (lobj->type != OBJT_VNODE || lobj->handle == NULL) { 1694 if (lobj != obj) 1695 VM_OBJECT_UNLOCK(lobj); 1696 VM_OBJECT_UNLOCK(obj); 1697 continue; 1698 } 1699 1700 /* 1701 * Skip contiguous regions that point to the same 1702 * vnode, so we don't emit redundant MAP-IN 1703 * directives. 1704 */ 1705 if (entry->start == last_end && lobj->handle == last_vp) { 1706 last_end = entry->end; 1707 if (lobj != obj) 1708 VM_OBJECT_UNLOCK(lobj); 1709 VM_OBJECT_UNLOCK(obj); 1710 continue; 1711 } 1712 1713 /* 1714 * We don't want to keep the proc's vm_map or this 1715 * vm_object locked while we walk the pathname, since 1716 * vn_fullpath() can sleep. However, if we drop the 1717 * lock, it's possible for concurrent activity to 1718 * modify the vm_map list. To protect against this, 1719 * we save the vm_map timestamp before we release the 1720 * lock, and check it after we reacquire the lock 1721 * below. 1722 */ 1723 start_addr = entry->start; 1724 last_end = entry->end; 1725 last_timestamp = map->timestamp; 1726 vm_map_unlock_read(map); 1727 1728 vp = lobj->handle; 1729 vref(vp); 1730 if (lobj != obj) 1731 VM_OBJECT_UNLOCK(lobj); 1732 1733 VM_OBJECT_UNLOCK(obj); 1734 1735 freepath = NULL; 1736 pmc_getfilename(vp, &fullpath, &freepath); 1737 last_vp = vp; 1738 1739 locked = VFS_LOCK_GIANT(vp->v_mount); 1740 vrele(vp); 1741 VFS_UNLOCK_GIANT(locked); 1742 1743 vp = NULL; 1744 pmclog_process_map_in(po, p->p_pid, start_addr, fullpath); 1745 if (freepath) 1746 free(freepath, M_TEMP); 1747 1748 vm_map_lock_read(map); 1749 1750 /* 1751 * If our saved timestamp doesn't match, this means 1752 * that the vm_map was modified out from under us and 1753 * we can't trust our current "entry" pointer. Do a 1754 * new lookup for this entry. If there is no entry 1755 * for this address range, vm_map_lookup_entry() will 1756 * return the previous one, so we always want to go to 1757 * entry->next on the next loop iteration. 1758 * 1759 * There is an edge condition here that can occur if 1760 * there is no entry at or before this address. In 1761 * this situation, vm_map_lookup_entry returns 1762 * &map->header, which would cause our loop to abort 1763 * without processing the rest of the map. However, 1764 * in practice this will never happen for process 1765 * vm_map. This is because the executable's text 1766 * segment is the first mapping in the proc's address 1767 * space, and this mapping is never removed until the 1768 * process exits, so there will always be a non-header 1769 * entry at or before the requested address for 1770 * vm_map_lookup_entry to return. 1771 */ 1772 if (map->timestamp != last_timestamp) 1773 vm_map_lookup_entry(map, last_end - 1, &entry); 1774 } 1775 1776 vm_map_unlock_read(map); 1777 vmspace_free(vm); 1778 return; 1779 } 1780 1781 /* 1782 * Log mappings for all processes in the system. 1783 */ 1784 1785 static void 1786 pmc_log_all_process_mappings(struct pmc_owner *po) 1787 { 1788 struct proc *p, *top; 1789 1790 sx_assert(&pmc_sx, SX_XLOCKED); 1791 1792 if ((p = pfind(1)) == NULL) 1793 panic("[pmc,%d] Cannot find init", __LINE__); 1794 1795 PROC_UNLOCK(p); 1796 1797 sx_slock(&proctree_lock); 1798 1799 top = p; 1800 1801 for (;;) { 1802 pmc_log_process_mappings(po, p); 1803 if (!LIST_EMPTY(&p->p_children)) 1804 p = LIST_FIRST(&p->p_children); 1805 else for (;;) { 1806 if (p == top) 1807 goto done; 1808 if (LIST_NEXT(p, p_sibling)) { 1809 p = LIST_NEXT(p, p_sibling); 1810 break; 1811 } 1812 p = p->p_pptr; 1813 } 1814 } 1815 done: 1816 sx_sunlock(&proctree_lock); 1817 } 1818 1819 /* 1820 * The 'hook' invoked from the kernel proper 1821 */ 1822 1823 1824 #ifdef DEBUG 1825 const char *pmc_hooknames[] = { 1826 /* these strings correspond to PMC_FN_* in <sys/pmckern.h> */ 1827 "", 1828 "EXEC", 1829 "CSW-IN", 1830 "CSW-OUT", 1831 "SAMPLE", 1832 "KLDLOAD", 1833 "KLDUNLOAD", 1834 "MMAP", 1835 "MUNMAP", 1836 "CALLCHAIN" 1837 }; 1838 #endif 1839 1840 static int 1841 pmc_hook_handler(struct thread *td, int function, void *arg) 1842 { 1843 1844 PMCDBG(MOD,PMH,1, "hook td=%p func=%d \"%s\" arg=%p", td, function, 1845 pmc_hooknames[function], arg); 1846 1847 switch (function) 1848 { 1849 1850 /* 1851 * Process exec() 1852 */ 1853 1854 case PMC_FN_PROCESS_EXEC: 1855 { 1856 char *fullpath, *freepath; 1857 unsigned int ri; 1858 int is_using_hwpmcs; 1859 struct pmc *pm; 1860 struct proc *p; 1861 struct pmc_owner *po; 1862 struct pmc_process *pp; 1863 struct pmckern_procexec *pk; 1864 1865 sx_assert(&pmc_sx, SX_XLOCKED); 1866 1867 p = td->td_proc; 1868 pmc_getfilename(p->p_textvp, &fullpath, &freepath); 1869 1870 pk = (struct pmckern_procexec *) arg; 1871 1872 /* Inform owners of SS mode PMCs of the exec event. */ 1873 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1874 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1875 pmclog_process_procexec(po, PMC_ID_INVALID, 1876 p->p_pid, pk->pm_entryaddr, fullpath); 1877 1878 PROC_LOCK(p); 1879 is_using_hwpmcs = p->p_flag & P_HWPMC; 1880 PROC_UNLOCK(p); 1881 1882 if (!is_using_hwpmcs) { 1883 if (freepath) 1884 free(freepath, M_TEMP); 1885 break; 1886 } 1887 1888 /* 1889 * PMCs are not inherited across an exec(): remove any 1890 * PMCs that this process is the owner of. 1891 */ 1892 1893 if ((po = pmc_find_owner_descriptor(p)) != NULL) { 1894 pmc_remove_owner(po); 1895 pmc_destroy_owner_descriptor(po); 1896 } 1897 1898 /* 1899 * If the process being exec'ed is not the target of any 1900 * PMC, we are done. 1901 */ 1902 if ((pp = pmc_find_process_descriptor(p, 0)) == NULL) { 1903 if (freepath) 1904 free(freepath, M_TEMP); 1905 break; 1906 } 1907 1908 /* 1909 * Log the exec event to all monitoring owners. Skip 1910 * owners who have already recieved the event because 1911 * they had system sampling PMCs active. 1912 */ 1913 for (ri = 0; ri < md->pmd_npmc; ri++) 1914 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) { 1915 po = pm->pm_owner; 1916 if (po->po_sscount == 0 && 1917 po->po_flags & PMC_PO_OWNS_LOGFILE) 1918 pmclog_process_procexec(po, pm->pm_id, 1919 p->p_pid, pk->pm_entryaddr, 1920 fullpath); 1921 } 1922 1923 if (freepath) 1924 free(freepath, M_TEMP); 1925 1926 1927 PMCDBG(PRC,EXC,1, "exec proc=%p (%d, %s) cred-changed=%d", 1928 p, p->p_pid, p->p_comm, pk->pm_credentialschanged); 1929 1930 if (pk->pm_credentialschanged == 0) /* no change */ 1931 break; 1932 1933 /* 1934 * If the newly exec()'ed process has a different credential 1935 * than before, allow it to be the target of a PMC only if 1936 * the PMC's owner has sufficient priviledge. 1937 */ 1938 1939 for (ri = 0; ri < md->pmd_npmc; ri++) 1940 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) 1941 if (pmc_can_attach(pm, td->td_proc) != 0) 1942 pmc_detach_one_process(td->td_proc, 1943 pm, PMC_FLAG_NONE); 1944 1945 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= (int) md->pmd_npmc, 1946 ("[pmc,%d] Illegal ref count %d on pp %p", __LINE__, 1947 pp->pp_refcnt, pp)); 1948 1949 /* 1950 * If this process is no longer the target of any 1951 * PMCs, we can remove the process entry and free 1952 * up space. 1953 */ 1954 1955 if (pp->pp_refcnt == 0) { 1956 pmc_remove_process_descriptor(pp); 1957 free(pp, M_PMC); 1958 break; 1959 } 1960 1961 } 1962 break; 1963 1964 case PMC_FN_CSW_IN: 1965 pmc_process_csw_in(td); 1966 break; 1967 1968 case PMC_FN_CSW_OUT: 1969 pmc_process_csw_out(td); 1970 break; 1971 1972 /* 1973 * Process accumulated PC samples. 1974 * 1975 * This function is expected to be called by hardclock() for 1976 * each CPU that has accumulated PC samples. 1977 * 1978 * This function is to be executed on the CPU whose samples 1979 * are being processed. 1980 */ 1981 case PMC_FN_DO_SAMPLES: 1982 1983 /* 1984 * Clear the cpu specific bit in the CPU mask before 1985 * do the rest of the processing. If the NMI handler 1986 * gets invoked after the "atomic_clear_int()" call 1987 * below but before "pmc_process_samples()" gets 1988 * around to processing the interrupt, then we will 1989 * come back here at the next hardclock() tick (and 1990 * may find nothing to do if "pmc_process_samples()" 1991 * had already processed the interrupt). We don't 1992 * lose the interrupt sample. 1993 */ 1994 atomic_clear_int(&pmc_cpumask, (1 << PCPU_GET(cpuid))); 1995 pmc_process_samples(PCPU_GET(cpuid)); 1996 break; 1997 1998 1999 case PMC_FN_KLD_LOAD: 2000 sx_assert(&pmc_sx, SX_LOCKED); 2001 pmc_process_kld_load((struct pmckern_map_in *) arg); 2002 break; 2003 2004 case PMC_FN_KLD_UNLOAD: 2005 sx_assert(&pmc_sx, SX_LOCKED); 2006 pmc_process_kld_unload((struct pmckern_map_out *) arg); 2007 break; 2008 2009 case PMC_FN_MMAP: 2010 sx_assert(&pmc_sx, SX_LOCKED); 2011 pmc_process_mmap(td, (struct pmckern_map_in *) arg); 2012 break; 2013 2014 case PMC_FN_MUNMAP: 2015 sx_assert(&pmc_sx, SX_LOCKED); 2016 pmc_process_munmap(td, (struct pmckern_map_out *) arg); 2017 break; 2018 2019 case PMC_FN_USER_CALLCHAIN: 2020 /* 2021 * Record a call chain. 2022 */ 2023 KASSERT(td == curthread, ("[pmc,%d] td != curthread", 2024 __LINE__)); 2025 pmc_capture_user_callchain(PCPU_GET(cpuid), 2026 (struct trapframe *) arg); 2027 td->td_pflags &= ~TDP_CALLCHAIN; 2028 break; 2029 2030 default: 2031 #ifdef DEBUG 2032 KASSERT(0, ("[pmc,%d] unknown hook %d\n", __LINE__, function)); 2033 #endif 2034 break; 2035 2036 } 2037 2038 return 0; 2039 } 2040 2041 /* 2042 * allocate a 'struct pmc_owner' descriptor in the owner hash table. 2043 */ 2044 2045 static struct pmc_owner * 2046 pmc_allocate_owner_descriptor(struct proc *p) 2047 { 2048 uint32_t hindex; 2049 struct pmc_owner *po; 2050 struct pmc_ownerhash *poh; 2051 2052 hindex = PMC_HASH_PTR(p, pmc_ownerhashmask); 2053 poh = &pmc_ownerhash[hindex]; 2054 2055 /* allocate space for N pointers and one descriptor struct */ 2056 po = malloc(sizeof(struct pmc_owner), M_PMC, M_WAITOK|M_ZERO); 2057 po->po_sscount = po->po_error = po->po_flags = po->po_logprocmaps = 0; 2058 po->po_file = NULL; 2059 po->po_owner = p; 2060 po->po_kthread = NULL; 2061 LIST_INIT(&po->po_pmcs); 2062 LIST_INSERT_HEAD(poh, po, po_next); /* insert into hash table */ 2063 2064 TAILQ_INIT(&po->po_logbuffers); 2065 mtx_init(&po->po_mtx, "pmc-owner-mtx", "pmc-per-proc", MTX_SPIN); 2066 2067 PMCDBG(OWN,ALL,1, "allocate-owner proc=%p (%d, %s) pmc-owner=%p", 2068 p, p->p_pid, p->p_comm, po); 2069 2070 return po; 2071 } 2072 2073 static void 2074 pmc_destroy_owner_descriptor(struct pmc_owner *po) 2075 { 2076 2077 PMCDBG(OWN,REL,1, "destroy-owner po=%p proc=%p (%d, %s)", 2078 po, po->po_owner, po->po_owner->p_pid, po->po_owner->p_comm); 2079 2080 mtx_destroy(&po->po_mtx); 2081 free(po, M_PMC); 2082 } 2083 2084 /* 2085 * find the descriptor corresponding to process 'p', adding or removing it 2086 * as specified by 'mode'. 2087 */ 2088 2089 static struct pmc_process * 2090 pmc_find_process_descriptor(struct proc *p, uint32_t mode) 2091 { 2092 uint32_t hindex; 2093 struct pmc_process *pp, *ppnew; 2094 struct pmc_processhash *pph; 2095 2096 hindex = PMC_HASH_PTR(p, pmc_processhashmask); 2097 pph = &pmc_processhash[hindex]; 2098 2099 ppnew = NULL; 2100 2101 /* 2102 * Pre-allocate memory in the FIND_ALLOCATE case since we 2103 * cannot call malloc(9) once we hold a spin lock. 2104 */ 2105 if (mode & PMC_FLAG_ALLOCATE) 2106 ppnew = malloc(sizeof(struct pmc_process) + md->pmd_npmc * 2107 sizeof(struct pmc_targetstate), M_PMC, M_WAITOK|M_ZERO); 2108 2109 mtx_lock_spin(&pmc_processhash_mtx); 2110 LIST_FOREACH(pp, pph, pp_next) 2111 if (pp->pp_proc == p) 2112 break; 2113 2114 if ((mode & PMC_FLAG_REMOVE) && pp != NULL) 2115 LIST_REMOVE(pp, pp_next); 2116 2117 if ((mode & PMC_FLAG_ALLOCATE) && pp == NULL && 2118 ppnew != NULL) { 2119 ppnew->pp_proc = p; 2120 LIST_INSERT_HEAD(pph, ppnew, pp_next); 2121 pp = ppnew; 2122 ppnew = NULL; 2123 } 2124 mtx_unlock_spin(&pmc_processhash_mtx); 2125 2126 if (pp != NULL && ppnew != NULL) 2127 free(ppnew, M_PMC); 2128 2129 return pp; 2130 } 2131 2132 /* 2133 * remove a process descriptor from the process hash table. 2134 */ 2135 2136 static void 2137 pmc_remove_process_descriptor(struct pmc_process *pp) 2138 { 2139 KASSERT(pp->pp_refcnt == 0, 2140 ("[pmc,%d] Removing process descriptor %p with count %d", 2141 __LINE__, pp, pp->pp_refcnt)); 2142 2143 mtx_lock_spin(&pmc_processhash_mtx); 2144 LIST_REMOVE(pp, pp_next); 2145 mtx_unlock_spin(&pmc_processhash_mtx); 2146 } 2147 2148 2149 /* 2150 * find an owner descriptor corresponding to proc 'p' 2151 */ 2152 2153 static struct pmc_owner * 2154 pmc_find_owner_descriptor(struct proc *p) 2155 { 2156 uint32_t hindex; 2157 struct pmc_owner *po; 2158 struct pmc_ownerhash *poh; 2159 2160 hindex = PMC_HASH_PTR(p, pmc_ownerhashmask); 2161 poh = &pmc_ownerhash[hindex]; 2162 2163 po = NULL; 2164 LIST_FOREACH(po, poh, po_next) 2165 if (po->po_owner == p) 2166 break; 2167 2168 PMCDBG(OWN,FND,1, "find-owner proc=%p (%d, %s) hindex=0x%x -> " 2169 "pmc-owner=%p", p, p->p_pid, p->p_comm, hindex, po); 2170 2171 return po; 2172 } 2173 2174 /* 2175 * pmc_allocate_pmc_descriptor 2176 * 2177 * Allocate a pmc descriptor and initialize its 2178 * fields. 2179 */ 2180 2181 static struct pmc * 2182 pmc_allocate_pmc_descriptor(void) 2183 { 2184 struct pmc *pmc; 2185 2186 pmc = malloc(sizeof(struct pmc), M_PMC, M_WAITOK|M_ZERO); 2187 2188 if (pmc != NULL) { 2189 pmc->pm_owner = NULL; 2190 LIST_INIT(&pmc->pm_targets); 2191 } 2192 2193 PMCDBG(PMC,ALL,1, "allocate-pmc -> pmc=%p", pmc); 2194 2195 return pmc; 2196 } 2197 2198 /* 2199 * Destroy a pmc descriptor. 2200 */ 2201 2202 static void 2203 pmc_destroy_pmc_descriptor(struct pmc *pm) 2204 { 2205 (void) pm; 2206 2207 #ifdef DEBUG 2208 KASSERT(pm->pm_state == PMC_STATE_DELETED || 2209 pm->pm_state == PMC_STATE_FREE, 2210 ("[pmc,%d] destroying non-deleted PMC", __LINE__)); 2211 KASSERT(LIST_EMPTY(&pm->pm_targets), 2212 ("[pmc,%d] destroying pmc with targets", __LINE__)); 2213 KASSERT(pm->pm_owner == NULL, 2214 ("[pmc,%d] destroying pmc attached to an owner", __LINE__)); 2215 KASSERT(pm->pm_runcount == 0, 2216 ("[pmc,%d] pmc has non-zero run count %d", __LINE__, 2217 pm->pm_runcount)); 2218 #endif 2219 } 2220 2221 static void 2222 pmc_wait_for_pmc_idle(struct pmc *pm) 2223 { 2224 #ifdef DEBUG 2225 volatile int maxloop; 2226 2227 maxloop = 100 * pmc_cpu_max(); 2228 #endif 2229 2230 /* 2231 * Loop (with a forced context switch) till the PMC's runcount 2232 * comes down to zero. 2233 */ 2234 while (atomic_load_acq_32(&pm->pm_runcount) > 0) { 2235 #ifdef DEBUG 2236 maxloop--; 2237 KASSERT(maxloop > 0, 2238 ("[pmc,%d] (ri%d, rc%d) waiting too long for " 2239 "pmc to be free", __LINE__, 2240 PMC_TO_ROWINDEX(pm), pm->pm_runcount)); 2241 #endif 2242 pmc_force_context_switch(); 2243 } 2244 } 2245 2246 /* 2247 * This function does the following things: 2248 * 2249 * - detaches the PMC from hardware 2250 * - unlinks all target threads that were attached to it 2251 * - removes the PMC from its owner's list 2252 * - destroy's the PMC private mutex 2253 * 2254 * Once this function completes, the given pmc pointer can be safely 2255 * FREE'd by the caller. 2256 */ 2257 2258 static void 2259 pmc_release_pmc_descriptor(struct pmc *pm) 2260 { 2261 enum pmc_mode mode; 2262 struct pmc_hw *phw; 2263 u_int adjri, ri, cpu; 2264 struct pmc_owner *po; 2265 struct pmc_binding pb; 2266 struct pmc_process *pp; 2267 struct pmc_classdep *pcd; 2268 struct pmc_target *ptgt, *tmp; 2269 2270 sx_assert(&pmc_sx, SX_XLOCKED); 2271 2272 KASSERT(pm, ("[pmc,%d] null pmc", __LINE__)); 2273 2274 ri = PMC_TO_ROWINDEX(pm); 2275 pcd = pmc_ri_to_classdep(md, ri, &adjri); 2276 mode = PMC_TO_MODE(pm); 2277 2278 PMCDBG(PMC,REL,1, "release-pmc pmc=%p ri=%d mode=%d", pm, ri, 2279 mode); 2280 2281 /* 2282 * First, we take the PMC off hardware. 2283 */ 2284 cpu = 0; 2285 if (PMC_IS_SYSTEM_MODE(mode)) { 2286 2287 /* 2288 * A system mode PMC runs on a specific CPU. Switch 2289 * to this CPU and turn hardware off. 2290 */ 2291 pmc_save_cpu_binding(&pb); 2292 2293 cpu = PMC_TO_CPU(pm); 2294 2295 pmc_select_cpu(cpu); 2296 2297 /* switch off non-stalled CPUs */ 2298 if (pm->pm_state == PMC_STATE_RUNNING && 2299 pm->pm_stalled == 0) { 2300 2301 phw = pmc_pcpu[cpu]->pc_hwpmcs[ri]; 2302 2303 KASSERT(phw->phw_pmc == pm, 2304 ("[pmc, %d] pmc ptr ri(%d) hw(%p) pm(%p)", 2305 __LINE__, ri, phw->phw_pmc, pm)); 2306 PMCDBG(PMC,REL,2, "stopping cpu=%d ri=%d", cpu, ri); 2307 2308 critical_enter(); 2309 pcd->pcd_stop_pmc(cpu, adjri); 2310 critical_exit(); 2311 } 2312 2313 PMCDBG(PMC,REL,2, "decfg cpu=%d ri=%d", cpu, ri); 2314 2315 critical_enter(); 2316 pcd->pcd_config_pmc(cpu, adjri, NULL); 2317 critical_exit(); 2318 2319 /* adjust the global and process count of SS mode PMCs */ 2320 if (mode == PMC_MODE_SS && pm->pm_state == PMC_STATE_RUNNING) { 2321 po = pm->pm_owner; 2322 po->po_sscount--; 2323 if (po->po_sscount == 0) { 2324 atomic_subtract_rel_int(&pmc_ss_count, 1); 2325 LIST_REMOVE(po, po_ssnext); 2326 } 2327 } 2328 2329 pm->pm_state = PMC_STATE_DELETED; 2330 2331 pmc_restore_cpu_binding(&pb); 2332 2333 /* 2334 * We could have references to this PMC structure in 2335 * the per-cpu sample queues. Wait for the queue to 2336 * drain. 2337 */ 2338 pmc_wait_for_pmc_idle(pm); 2339 2340 } else if (PMC_IS_VIRTUAL_MODE(mode)) { 2341 2342 /* 2343 * A virtual PMC could be running on multiple CPUs at 2344 * a given instant. 2345 * 2346 * By marking its state as DELETED, we ensure that 2347 * this PMC is never further scheduled on hardware. 2348 * 2349 * Then we wait till all CPUs are done with this PMC. 2350 */ 2351 pm->pm_state = PMC_STATE_DELETED; 2352 2353 2354 /* Wait for the PMCs runcount to come to zero. */ 2355 pmc_wait_for_pmc_idle(pm); 2356 2357 /* 2358 * At this point the PMC is off all CPUs and cannot be 2359 * freshly scheduled onto a CPU. It is now safe to 2360 * unlink all targets from this PMC. If a 2361 * process-record's refcount falls to zero, we remove 2362 * it from the hash table. The module-wide SX lock 2363 * protects us from races. 2364 */ 2365 LIST_FOREACH_SAFE(ptgt, &pm->pm_targets, pt_next, tmp) { 2366 pp = ptgt->pt_process; 2367 pmc_unlink_target_process(pm, pp); /* frees 'ptgt' */ 2368 2369 PMCDBG(PMC,REL,3, "pp->refcnt=%d", pp->pp_refcnt); 2370 2371 /* 2372 * If the target process record shows that no 2373 * PMCs are attached to it, reclaim its space. 2374 */ 2375 2376 if (pp->pp_refcnt == 0) { 2377 pmc_remove_process_descriptor(pp); 2378 free(pp, M_PMC); 2379 } 2380 } 2381 2382 cpu = curthread->td_oncpu; /* setup cpu for pmd_release() */ 2383 2384 } 2385 2386 /* 2387 * Release any MD resources 2388 */ 2389 (void) pcd->pcd_release_pmc(cpu, adjri, pm); 2390 2391 /* 2392 * Update row disposition 2393 */ 2394 2395 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) 2396 PMC_UNMARK_ROW_STANDALONE(ri); 2397 else 2398 PMC_UNMARK_ROW_THREAD(ri); 2399 2400 /* unlink from the owner's list */ 2401 if (pm->pm_owner) { 2402 LIST_REMOVE(pm, pm_next); 2403 pm->pm_owner = NULL; 2404 } 2405 2406 pmc_destroy_pmc_descriptor(pm); 2407 } 2408 2409 /* 2410 * Register an owner and a pmc. 2411 */ 2412 2413 static int 2414 pmc_register_owner(struct proc *p, struct pmc *pmc) 2415 { 2416 struct pmc_owner *po; 2417 2418 sx_assert(&pmc_sx, SX_XLOCKED); 2419 2420 if ((po = pmc_find_owner_descriptor(p)) == NULL) 2421 if ((po = pmc_allocate_owner_descriptor(p)) == NULL) 2422 return ENOMEM; 2423 2424 KASSERT(pmc->pm_owner == NULL, 2425 ("[pmc,%d] attempting to own an initialized PMC", __LINE__)); 2426 pmc->pm_owner = po; 2427 2428 LIST_INSERT_HEAD(&po->po_pmcs, pmc, pm_next); 2429 2430 PROC_LOCK(p); 2431 p->p_flag |= P_HWPMC; 2432 PROC_UNLOCK(p); 2433 2434 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 2435 pmclog_process_pmcallocate(pmc); 2436 2437 PMCDBG(PMC,REG,1, "register-owner pmc-owner=%p pmc=%p", 2438 po, pmc); 2439 2440 return 0; 2441 } 2442 2443 /* 2444 * Return the current row disposition: 2445 * == 0 => FREE 2446 * > 0 => PROCESS MODE 2447 * < 0 => SYSTEM MODE 2448 */ 2449 2450 int 2451 pmc_getrowdisp(int ri) 2452 { 2453 return pmc_pmcdisp[ri]; 2454 } 2455 2456 /* 2457 * Check if a PMC at row index 'ri' can be allocated to the current 2458 * process. 2459 * 2460 * Allocation can fail if: 2461 * - the current process is already being profiled by a PMC at index 'ri', 2462 * attached to it via OP_PMCATTACH. 2463 * - the current process has already allocated a PMC at index 'ri' 2464 * via OP_ALLOCATE. 2465 */ 2466 2467 static int 2468 pmc_can_allocate_rowindex(struct proc *p, unsigned int ri, int cpu) 2469 { 2470 enum pmc_mode mode; 2471 struct pmc *pm; 2472 struct pmc_owner *po; 2473 struct pmc_process *pp; 2474 2475 PMCDBG(PMC,ALR,1, "can-allocate-rowindex proc=%p (%d, %s) ri=%d " 2476 "cpu=%d", p, p->p_pid, p->p_comm, ri, cpu); 2477 2478 /* 2479 * We shouldn't have already allocated a process-mode PMC at 2480 * row index 'ri'. 2481 * 2482 * We shouldn't have allocated a system-wide PMC on the same 2483 * CPU and same RI. 2484 */ 2485 if ((po = pmc_find_owner_descriptor(p)) != NULL) 2486 LIST_FOREACH(pm, &po->po_pmcs, pm_next) { 2487 if (PMC_TO_ROWINDEX(pm) == ri) { 2488 mode = PMC_TO_MODE(pm); 2489 if (PMC_IS_VIRTUAL_MODE(mode)) 2490 return EEXIST; 2491 if (PMC_IS_SYSTEM_MODE(mode) && 2492 (int) PMC_TO_CPU(pm) == cpu) 2493 return EEXIST; 2494 } 2495 } 2496 2497 /* 2498 * We also shouldn't be the target of any PMC at this index 2499 * since otherwise a PMC_ATTACH to ourselves will fail. 2500 */ 2501 if ((pp = pmc_find_process_descriptor(p, 0)) != NULL) 2502 if (pp->pp_pmcs[ri].pp_pmc) 2503 return EEXIST; 2504 2505 PMCDBG(PMC,ALR,2, "can-allocate-rowindex proc=%p (%d, %s) ri=%d ok", 2506 p, p->p_pid, p->p_comm, ri); 2507 2508 return 0; 2509 } 2510 2511 /* 2512 * Check if a given PMC at row index 'ri' can be currently used in 2513 * mode 'mode'. 2514 */ 2515 2516 static int 2517 pmc_can_allocate_row(int ri, enum pmc_mode mode) 2518 { 2519 enum pmc_disp disp; 2520 2521 sx_assert(&pmc_sx, SX_XLOCKED); 2522 2523 PMCDBG(PMC,ALR,1, "can-allocate-row ri=%d mode=%d", ri, mode); 2524 2525 if (PMC_IS_SYSTEM_MODE(mode)) 2526 disp = PMC_DISP_STANDALONE; 2527 else 2528 disp = PMC_DISP_THREAD; 2529 2530 /* 2531 * check disposition for PMC row 'ri': 2532 * 2533 * Expected disposition Row-disposition Result 2534 * 2535 * STANDALONE STANDALONE or FREE proceed 2536 * STANDALONE THREAD fail 2537 * THREAD THREAD or FREE proceed 2538 * THREAD STANDALONE fail 2539 */ 2540 2541 if (!PMC_ROW_DISP_IS_FREE(ri) && 2542 !(disp == PMC_DISP_THREAD && PMC_ROW_DISP_IS_THREAD(ri)) && 2543 !(disp == PMC_DISP_STANDALONE && PMC_ROW_DISP_IS_STANDALONE(ri))) 2544 return EBUSY; 2545 2546 /* 2547 * All OK 2548 */ 2549 2550 PMCDBG(PMC,ALR,2, "can-allocate-row ri=%d mode=%d ok", ri, mode); 2551 2552 return 0; 2553 2554 } 2555 2556 /* 2557 * Find a PMC descriptor with user handle 'pmcid' for thread 'td'. 2558 */ 2559 2560 static struct pmc * 2561 pmc_find_pmc_descriptor_in_process(struct pmc_owner *po, pmc_id_t pmcid) 2562 { 2563 struct pmc *pm; 2564 2565 KASSERT(PMC_ID_TO_ROWINDEX(pmcid) < md->pmd_npmc, 2566 ("[pmc,%d] Illegal pmc index %d (max %d)", __LINE__, 2567 PMC_ID_TO_ROWINDEX(pmcid), md->pmd_npmc)); 2568 2569 LIST_FOREACH(pm, &po->po_pmcs, pm_next) 2570 if (pm->pm_id == pmcid) 2571 return pm; 2572 2573 return NULL; 2574 } 2575 2576 static int 2577 pmc_find_pmc(pmc_id_t pmcid, struct pmc **pmc) 2578 { 2579 2580 struct pmc *pm; 2581 struct pmc_owner *po; 2582 2583 PMCDBG(PMC,FND,1, "find-pmc id=%d", pmcid); 2584 2585 if ((po = pmc_find_owner_descriptor(curthread->td_proc)) == NULL) 2586 return ESRCH; 2587 2588 if ((pm = pmc_find_pmc_descriptor_in_process(po, pmcid)) == NULL) 2589 return EINVAL; 2590 2591 PMCDBG(PMC,FND,2, "find-pmc id=%d -> pmc=%p", pmcid, pm); 2592 2593 *pmc = pm; 2594 return 0; 2595 } 2596 2597 /* 2598 * Start a PMC. 2599 */ 2600 2601 static int 2602 pmc_start(struct pmc *pm) 2603 { 2604 enum pmc_mode mode; 2605 struct pmc_owner *po; 2606 struct pmc_binding pb; 2607 struct pmc_classdep *pcd; 2608 int adjri, error, cpu, ri; 2609 2610 KASSERT(pm != NULL, 2611 ("[pmc,%d] null pm", __LINE__)); 2612 2613 mode = PMC_TO_MODE(pm); 2614 ri = PMC_TO_ROWINDEX(pm); 2615 pcd = pmc_ri_to_classdep(md, ri, &adjri); 2616 2617 error = 0; 2618 2619 PMCDBG(PMC,OPS,1, "start pmc=%p mode=%d ri=%d", pm, mode, ri); 2620 2621 po = pm->pm_owner; 2622 2623 /* 2624 * Disallow PMCSTART if a logfile is required but has not been 2625 * configured yet. 2626 */ 2627 if ((pm->pm_flags & PMC_F_NEEDS_LOGFILE) && 2628 (po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) 2629 return (EDOOFUS); /* programming error */ 2630 2631 /* 2632 * If this is a sampling mode PMC, log mapping information for 2633 * the kernel modules that are currently loaded. 2634 */ 2635 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 2636 pmc_log_kernel_mappings(pm); 2637 2638 if (PMC_IS_VIRTUAL_MODE(mode)) { 2639 2640 /* 2641 * If a PMCATTACH has never been done on this PMC, 2642 * attach it to its owner process. 2643 */ 2644 2645 if (LIST_EMPTY(&pm->pm_targets)) 2646 error = (pm->pm_flags & PMC_F_ATTACH_DONE) ? ESRCH : 2647 pmc_attach_process(po->po_owner, pm); 2648 2649 /* 2650 * If the PMC is attached to its owner, then force a context 2651 * switch to ensure that the MD state gets set correctly. 2652 */ 2653 2654 if (error == 0) { 2655 pm->pm_state = PMC_STATE_RUNNING; 2656 if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) 2657 pmc_force_context_switch(); 2658 } 2659 2660 return (error); 2661 } 2662 2663 2664 /* 2665 * A system-wide PMC. 2666 * 2667 * Add the owner to the global list if this is a system-wide 2668 * sampling PMC. 2669 */ 2670 2671 if (mode == PMC_MODE_SS) { 2672 if (po->po_sscount == 0) { 2673 LIST_INSERT_HEAD(&pmc_ss_owners, po, po_ssnext); 2674 atomic_add_rel_int(&pmc_ss_count, 1); 2675 PMCDBG(PMC,OPS,1, "po=%p in global list", po); 2676 } 2677 po->po_sscount++; 2678 } 2679 2680 /* 2681 * Log mapping information for all existing processes in the 2682 * system. Subsequent mappings are logged as they happen; 2683 * see pmc_process_mmap(). 2684 */ 2685 if (po->po_logprocmaps == 0) { 2686 pmc_log_all_process_mappings(po); 2687 po->po_logprocmaps = 1; 2688 } 2689 2690 /* 2691 * Move to the CPU associated with this 2692 * PMC, and start the hardware. 2693 */ 2694 2695 pmc_save_cpu_binding(&pb); 2696 2697 cpu = PMC_TO_CPU(pm); 2698 2699 if (!pmc_cpu_is_active(cpu)) 2700 return (ENXIO); 2701 2702 pmc_select_cpu(cpu); 2703 2704 /* 2705 * global PMCs are configured at allocation time 2706 * so write out the initial value and start the PMC. 2707 */ 2708 2709 pm->pm_state = PMC_STATE_RUNNING; 2710 2711 critical_enter(); 2712 if ((error = pcd->pcd_write_pmc(cpu, adjri, 2713 PMC_IS_SAMPLING_MODE(mode) ? 2714 pm->pm_sc.pm_reloadcount : 2715 pm->pm_sc.pm_initial)) == 0) 2716 error = pcd->pcd_start_pmc(cpu, adjri); 2717 critical_exit(); 2718 2719 pmc_restore_cpu_binding(&pb); 2720 2721 return (error); 2722 } 2723 2724 /* 2725 * Stop a PMC. 2726 */ 2727 2728 static int 2729 pmc_stop(struct pmc *pm) 2730 { 2731 struct pmc_owner *po; 2732 struct pmc_binding pb; 2733 struct pmc_classdep *pcd; 2734 int adjri, cpu, error, ri; 2735 2736 KASSERT(pm != NULL, ("[pmc,%d] null pmc", __LINE__)); 2737 2738 PMCDBG(PMC,OPS,1, "stop pmc=%p mode=%d ri=%d", pm, 2739 PMC_TO_MODE(pm), PMC_TO_ROWINDEX(pm)); 2740 2741 pm->pm_state = PMC_STATE_STOPPED; 2742 2743 /* 2744 * If the PMC is a virtual mode one, changing the state to 2745 * non-RUNNING is enough to ensure that the PMC never gets 2746 * scheduled. 2747 * 2748 * If this PMC is current running on a CPU, then it will 2749 * handled correctly at the time its target process is context 2750 * switched out. 2751 */ 2752 2753 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) 2754 return 0; 2755 2756 /* 2757 * A system-mode PMC. Move to the CPU associated with 2758 * this PMC, and stop the hardware. We update the 2759 * 'initial count' so that a subsequent PMCSTART will 2760 * resume counting from the current hardware count. 2761 */ 2762 2763 pmc_save_cpu_binding(&pb); 2764 2765 cpu = PMC_TO_CPU(pm); 2766 2767 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 2768 ("[pmc,%d] illegal cpu=%d", __LINE__, cpu)); 2769 2770 if (!pmc_cpu_is_active(cpu)) 2771 return ENXIO; 2772 2773 pmc_select_cpu(cpu); 2774 2775 ri = PMC_TO_ROWINDEX(pm); 2776 pcd = pmc_ri_to_classdep(md, ri, &adjri); 2777 2778 critical_enter(); 2779 if ((error = pcd->pcd_stop_pmc(cpu, adjri)) == 0) 2780 error = pcd->pcd_read_pmc(cpu, adjri, &pm->pm_sc.pm_initial); 2781 critical_exit(); 2782 2783 pmc_restore_cpu_binding(&pb); 2784 2785 po = pm->pm_owner; 2786 2787 /* remove this owner from the global list of SS PMC owners */ 2788 if (PMC_TO_MODE(pm) == PMC_MODE_SS) { 2789 po->po_sscount--; 2790 if (po->po_sscount == 0) { 2791 atomic_subtract_rel_int(&pmc_ss_count, 1); 2792 LIST_REMOVE(po, po_ssnext); 2793 PMCDBG(PMC,OPS,2,"po=%p removed from global list", po); 2794 } 2795 } 2796 2797 return (error); 2798 } 2799 2800 2801 #ifdef DEBUG 2802 static const char *pmc_op_to_name[] = { 2803 #undef __PMC_OP 2804 #define __PMC_OP(N, D) #N , 2805 __PMC_OPS() 2806 NULL 2807 }; 2808 #endif 2809 2810 /* 2811 * The syscall interface 2812 */ 2813 2814 #define PMC_GET_SX_XLOCK(...) do { \ 2815 sx_xlock(&pmc_sx); \ 2816 if (pmc_hook == NULL) { \ 2817 sx_xunlock(&pmc_sx); \ 2818 return __VA_ARGS__; \ 2819 } \ 2820 } while (0) 2821 2822 #define PMC_DOWNGRADE_SX() do { \ 2823 sx_downgrade(&pmc_sx); \ 2824 is_sx_downgraded = 1; \ 2825 } while (0) 2826 2827 static int 2828 pmc_syscall_handler(struct thread *td, void *syscall_args) 2829 { 2830 int error, is_sx_downgraded, is_sx_locked, op; 2831 struct pmc_syscall_args *c; 2832 void *arg; 2833 2834 PMC_GET_SX_XLOCK(ENOSYS); 2835 2836 DROP_GIANT(); 2837 2838 is_sx_downgraded = 0; 2839 is_sx_locked = 1; 2840 2841 c = (struct pmc_syscall_args *) syscall_args; 2842 2843 op = c->pmop_code; 2844 arg = c->pmop_data; 2845 2846 PMCDBG(MOD,PMS,1, "syscall op=%d \"%s\" arg=%p", op, 2847 pmc_op_to_name[op], arg); 2848 2849 error = 0; 2850 atomic_add_int(&pmc_stats.pm_syscalls, 1); 2851 2852 switch(op) 2853 { 2854 2855 2856 /* 2857 * Configure a log file. 2858 * 2859 * XXX This OP will be reworked. 2860 */ 2861 2862 case PMC_OP_CONFIGURELOG: 2863 { 2864 struct proc *p; 2865 struct pmc *pm; 2866 struct pmc_owner *po; 2867 struct pmc_op_configurelog cl; 2868 2869 sx_assert(&pmc_sx, SX_XLOCKED); 2870 2871 if ((error = copyin(arg, &cl, sizeof(cl))) != 0) 2872 break; 2873 2874 /* mark this process as owning a log file */ 2875 p = td->td_proc; 2876 if ((po = pmc_find_owner_descriptor(p)) == NULL) 2877 if ((po = pmc_allocate_owner_descriptor(p)) == NULL) { 2878 error = ENOMEM; 2879 break; 2880 } 2881 2882 /* 2883 * If a valid fd was passed in, try to configure that, 2884 * otherwise if 'fd' was less than zero and there was 2885 * a log file configured, flush its buffers and 2886 * de-configure it. 2887 */ 2888 if (cl.pm_logfd >= 0) { 2889 sx_xunlock(&pmc_sx); 2890 is_sx_locked = 0; 2891 error = pmclog_configure_log(md, po, cl.pm_logfd); 2892 } else if (po->po_flags & PMC_PO_OWNS_LOGFILE) { 2893 pmclog_process_closelog(po); 2894 error = pmclog_flush(po); 2895 if (error == 0) { 2896 LIST_FOREACH(pm, &po->po_pmcs, pm_next) 2897 if (pm->pm_flags & PMC_F_NEEDS_LOGFILE && 2898 pm->pm_state == PMC_STATE_RUNNING) 2899 pmc_stop(pm); 2900 error = pmclog_deconfigure_log(po); 2901 } 2902 } else 2903 error = EINVAL; 2904 2905 if (error) 2906 break; 2907 } 2908 break; 2909 2910 2911 /* 2912 * Flush a log file. 2913 */ 2914 2915 case PMC_OP_FLUSHLOG: 2916 { 2917 struct pmc_owner *po; 2918 2919 sx_assert(&pmc_sx, SX_XLOCKED); 2920 2921 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 2922 error = EINVAL; 2923 break; 2924 } 2925 2926 error = pmclog_flush(po); 2927 } 2928 break; 2929 2930 /* 2931 * Retrieve hardware configuration. 2932 */ 2933 2934 case PMC_OP_GETCPUINFO: /* CPU information */ 2935 { 2936 struct pmc_op_getcpuinfo gci; 2937 struct pmc_classinfo *pci; 2938 struct pmc_classdep *pcd; 2939 int cl; 2940 2941 gci.pm_cputype = md->pmd_cputype; 2942 gci.pm_ncpu = pmc_cpu_max(); 2943 gci.pm_npmc = md->pmd_npmc; 2944 gci.pm_nclass = md->pmd_nclass; 2945 pci = gci.pm_classes; 2946 pcd = md->pmd_classdep; 2947 for (cl = 0; cl < md->pmd_nclass; cl++, pci++, pcd++) { 2948 pci->pm_caps = pcd->pcd_caps; 2949 pci->pm_class = pcd->pcd_class; 2950 pci->pm_width = pcd->pcd_width; 2951 pci->pm_num = pcd->pcd_num; 2952 } 2953 error = copyout(&gci, arg, sizeof(gci)); 2954 } 2955 break; 2956 2957 2958 /* 2959 * Get module statistics 2960 */ 2961 2962 case PMC_OP_GETDRIVERSTATS: 2963 { 2964 struct pmc_op_getdriverstats gms; 2965 2966 bcopy(&pmc_stats, &gms, sizeof(gms)); 2967 error = copyout(&gms, arg, sizeof(gms)); 2968 } 2969 break; 2970 2971 2972 /* 2973 * Retrieve module version number 2974 */ 2975 2976 case PMC_OP_GETMODULEVERSION: 2977 { 2978 uint32_t cv, modv; 2979 2980 /* retrieve the client's idea of the ABI version */ 2981 if ((error = copyin(arg, &cv, sizeof(uint32_t))) != 0) 2982 break; 2983 /* don't service clients newer than our driver */ 2984 modv = PMC_VERSION; 2985 if ((cv & 0xFFFF0000) > (modv & 0xFFFF0000)) { 2986 error = EPROGMISMATCH; 2987 break; 2988 } 2989 error = copyout(&modv, arg, sizeof(int)); 2990 } 2991 break; 2992 2993 2994 /* 2995 * Retrieve the state of all the PMCs on a given 2996 * CPU. 2997 */ 2998 2999 case PMC_OP_GETPMCINFO: 3000 { 3001 int ari; 3002 struct pmc *pm; 3003 size_t pmcinfo_size; 3004 uint32_t cpu, n, npmc; 3005 struct pmc_owner *po; 3006 struct pmc_binding pb; 3007 struct pmc_classdep *pcd; 3008 struct pmc_info *p, *pmcinfo; 3009 struct pmc_op_getpmcinfo *gpi; 3010 3011 PMC_DOWNGRADE_SX(); 3012 3013 gpi = (struct pmc_op_getpmcinfo *) arg; 3014 3015 if ((error = copyin(&gpi->pm_cpu, &cpu, sizeof(cpu))) != 0) 3016 break; 3017 3018 if (cpu >= pmc_cpu_max()) { 3019 error = EINVAL; 3020 break; 3021 } 3022 3023 if (!pmc_cpu_is_active(cpu)) { 3024 error = ENXIO; 3025 break; 3026 } 3027 3028 /* switch to CPU 'cpu' */ 3029 pmc_save_cpu_binding(&pb); 3030 pmc_select_cpu(cpu); 3031 3032 npmc = md->pmd_npmc; 3033 3034 pmcinfo_size = npmc * sizeof(struct pmc_info); 3035 pmcinfo = malloc(pmcinfo_size, M_PMC, M_WAITOK); 3036 3037 p = pmcinfo; 3038 3039 for (n = 0; n < md->pmd_npmc; n++, p++) { 3040 3041 pcd = pmc_ri_to_classdep(md, n, &ari); 3042 3043 KASSERT(pcd != NULL, 3044 ("[pmc,%d] null pcd ri=%d", __LINE__, n)); 3045 3046 if ((error = pcd->pcd_describe(cpu, ari, p, &pm)) != 0) 3047 break; 3048 3049 if (PMC_ROW_DISP_IS_STANDALONE(n)) 3050 p->pm_rowdisp = PMC_DISP_STANDALONE; 3051 else if (PMC_ROW_DISP_IS_THREAD(n)) 3052 p->pm_rowdisp = PMC_DISP_THREAD; 3053 else 3054 p->pm_rowdisp = PMC_DISP_FREE; 3055 3056 p->pm_ownerpid = -1; 3057 3058 if (pm == NULL) /* no PMC associated */ 3059 continue; 3060 3061 po = pm->pm_owner; 3062 3063 KASSERT(po->po_owner != NULL, 3064 ("[pmc,%d] pmc_owner had a null proc pointer", 3065 __LINE__)); 3066 3067 p->pm_ownerpid = po->po_owner->p_pid; 3068 p->pm_mode = PMC_TO_MODE(pm); 3069 p->pm_event = pm->pm_event; 3070 p->pm_flags = pm->pm_flags; 3071 3072 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 3073 p->pm_reloadcount = 3074 pm->pm_sc.pm_reloadcount; 3075 } 3076 3077 pmc_restore_cpu_binding(&pb); 3078 3079 /* now copy out the PMC info collected */ 3080 if (error == 0) 3081 error = copyout(pmcinfo, &gpi->pm_pmcs, pmcinfo_size); 3082 3083 free(pmcinfo, M_PMC); 3084 } 3085 break; 3086 3087 3088 /* 3089 * Set the administrative state of a PMC. I.e. whether 3090 * the PMC is to be used or not. 3091 */ 3092 3093 case PMC_OP_PMCADMIN: 3094 { 3095 int cpu, ri; 3096 enum pmc_state request; 3097 struct pmc_cpu *pc; 3098 struct pmc_hw *phw; 3099 struct pmc_op_pmcadmin pma; 3100 struct pmc_binding pb; 3101 3102 sx_assert(&pmc_sx, SX_XLOCKED); 3103 3104 KASSERT(td == curthread, 3105 ("[pmc,%d] td != curthread", __LINE__)); 3106 3107 error = priv_check(td, PRIV_PMC_MANAGE); 3108 if (error) 3109 break; 3110 3111 if ((error = copyin(arg, &pma, sizeof(pma))) != 0) 3112 break; 3113 3114 cpu = pma.pm_cpu; 3115 3116 if (cpu < 0 || cpu >= (int) pmc_cpu_max()) { 3117 error = EINVAL; 3118 break; 3119 } 3120 3121 if (!pmc_cpu_is_active(cpu)) { 3122 error = ENXIO; 3123 break; 3124 } 3125 3126 request = pma.pm_state; 3127 3128 if (request != PMC_STATE_DISABLED && 3129 request != PMC_STATE_FREE) { 3130 error = EINVAL; 3131 break; 3132 } 3133 3134 ri = pma.pm_pmc; /* pmc id == row index */ 3135 if (ri < 0 || ri >= (int) md->pmd_npmc) { 3136 error = EINVAL; 3137 break; 3138 } 3139 3140 /* 3141 * We can't disable a PMC with a row-index allocated 3142 * for process virtual PMCs. 3143 */ 3144 3145 if (PMC_ROW_DISP_IS_THREAD(ri) && 3146 request == PMC_STATE_DISABLED) { 3147 error = EBUSY; 3148 break; 3149 } 3150 3151 /* 3152 * otherwise, this PMC on this CPU is either free or 3153 * in system-wide mode. 3154 */ 3155 3156 pmc_save_cpu_binding(&pb); 3157 pmc_select_cpu(cpu); 3158 3159 pc = pmc_pcpu[cpu]; 3160 phw = pc->pc_hwpmcs[ri]; 3161 3162 /* 3163 * XXX do we need some kind of 'forced' disable? 3164 */ 3165 3166 if (phw->phw_pmc == NULL) { 3167 if (request == PMC_STATE_DISABLED && 3168 (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED)) { 3169 phw->phw_state &= ~PMC_PHW_FLAG_IS_ENABLED; 3170 PMC_MARK_ROW_STANDALONE(ri); 3171 } else if (request == PMC_STATE_FREE && 3172 (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0) { 3173 phw->phw_state |= PMC_PHW_FLAG_IS_ENABLED; 3174 PMC_UNMARK_ROW_STANDALONE(ri); 3175 } 3176 /* other cases are a no-op */ 3177 } else 3178 error = EBUSY; 3179 3180 pmc_restore_cpu_binding(&pb); 3181 } 3182 break; 3183 3184 3185 /* 3186 * Allocate a PMC. 3187 */ 3188 3189 case PMC_OP_PMCALLOCATE: 3190 { 3191 int adjri, n; 3192 u_int cpu; 3193 uint32_t caps; 3194 struct pmc *pmc; 3195 enum pmc_mode mode; 3196 struct pmc_hw *phw; 3197 struct pmc_binding pb; 3198 struct pmc_classdep *pcd; 3199 struct pmc_op_pmcallocate pa; 3200 3201 if ((error = copyin(arg, &pa, sizeof(pa))) != 0) 3202 break; 3203 3204 caps = pa.pm_caps; 3205 mode = pa.pm_mode; 3206 cpu = pa.pm_cpu; 3207 3208 if ((mode != PMC_MODE_SS && mode != PMC_MODE_SC && 3209 mode != PMC_MODE_TS && mode != PMC_MODE_TC) || 3210 (cpu != (u_int) PMC_CPU_ANY && cpu >= pmc_cpu_max())) { 3211 error = EINVAL; 3212 break; 3213 } 3214 3215 /* 3216 * Virtual PMCs should only ask for a default CPU. 3217 * System mode PMCs need to specify a non-default CPU. 3218 */ 3219 3220 if ((PMC_IS_VIRTUAL_MODE(mode) && cpu != (u_int) PMC_CPU_ANY) || 3221 (PMC_IS_SYSTEM_MODE(mode) && cpu == (u_int) PMC_CPU_ANY)) { 3222 error = EINVAL; 3223 break; 3224 } 3225 3226 /* 3227 * Check that an inactive CPU is not being asked for. 3228 */ 3229 3230 if (PMC_IS_SYSTEM_MODE(mode) && !pmc_cpu_is_active(cpu)) { 3231 error = ENXIO; 3232 break; 3233 } 3234 3235 /* 3236 * Refuse an allocation for a system-wide PMC if this 3237 * process has been jailed, or if this process lacks 3238 * super-user credentials and the sysctl tunable 3239 * 'security.bsd.unprivileged_syspmcs' is zero. 3240 */ 3241 3242 if (PMC_IS_SYSTEM_MODE(mode)) { 3243 if (jailed(curthread->td_ucred)) { 3244 error = EPERM; 3245 break; 3246 } 3247 if (!pmc_unprivileged_syspmcs) { 3248 error = priv_check(curthread, 3249 PRIV_PMC_SYSTEM); 3250 if (error) 3251 break; 3252 } 3253 } 3254 3255 if (error) 3256 break; 3257 3258 /* 3259 * Look for valid values for 'pm_flags' 3260 */ 3261 3262 if ((pa.pm_flags & ~(PMC_F_DESCENDANTS | PMC_F_LOG_PROCCSW | 3263 PMC_F_LOG_PROCEXIT | PMC_F_CALLCHAIN)) != 0) { 3264 error = EINVAL; 3265 break; 3266 } 3267 3268 /* process logging options are not allowed for system PMCs */ 3269 if (PMC_IS_SYSTEM_MODE(mode) && (pa.pm_flags & 3270 (PMC_F_LOG_PROCCSW | PMC_F_LOG_PROCEXIT))) { 3271 error = EINVAL; 3272 break; 3273 } 3274 3275 /* 3276 * All sampling mode PMCs need to be able to interrupt the 3277 * CPU. 3278 */ 3279 if (PMC_IS_SAMPLING_MODE(mode)) 3280 caps |= PMC_CAP_INTERRUPT; 3281 3282 /* A valid class specifier should have been passed in. */ 3283 for (n = 0; n < md->pmd_nclass; n++) 3284 if (md->pmd_classdep[n].pcd_class == pa.pm_class) 3285 break; 3286 if (n == md->pmd_nclass) { 3287 error = EINVAL; 3288 break; 3289 } 3290 3291 /* The requested PMC capabilities should be feasible. */ 3292 if ((md->pmd_classdep[n].pcd_caps & caps) != caps) { 3293 error = EOPNOTSUPP; 3294 break; 3295 } 3296 3297 PMCDBG(PMC,ALL,2, "event=%d caps=0x%x mode=%d cpu=%d", 3298 pa.pm_ev, caps, mode, cpu); 3299 3300 pmc = pmc_allocate_pmc_descriptor(); 3301 pmc->pm_id = PMC_ID_MAKE_ID(cpu,pa.pm_mode,pa.pm_class, 3302 PMC_ID_INVALID); 3303 pmc->pm_event = pa.pm_ev; 3304 pmc->pm_state = PMC_STATE_FREE; 3305 pmc->pm_caps = caps; 3306 pmc->pm_flags = pa.pm_flags; 3307 3308 /* switch thread to CPU 'cpu' */ 3309 pmc_save_cpu_binding(&pb); 3310 3311 #define PMC_IS_SHAREABLE_PMC(cpu, n) \ 3312 (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_state & \ 3313 PMC_PHW_FLAG_IS_SHAREABLE) 3314 #define PMC_IS_UNALLOCATED(cpu, n) \ 3315 (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_pmc == NULL) 3316 3317 if (PMC_IS_SYSTEM_MODE(mode)) { 3318 pmc_select_cpu(cpu); 3319 for (n = 0; n < (int) md->pmd_npmc; n++) { 3320 pcd = pmc_ri_to_classdep(md, n, &adjri); 3321 if (pmc_can_allocate_row(n, mode) == 0 && 3322 pmc_can_allocate_rowindex( 3323 curthread->td_proc, n, cpu) == 0 && 3324 (PMC_IS_UNALLOCATED(cpu, n) || 3325 PMC_IS_SHAREABLE_PMC(cpu, n)) && 3326 pcd->pcd_allocate_pmc(cpu, adjri, pmc, 3327 &pa) == 0) 3328 break; 3329 } 3330 } else { 3331 /* Process virtual mode */ 3332 for (n = 0; n < (int) md->pmd_npmc; n++) { 3333 pcd = pmc_ri_to_classdep(md, n, &adjri); 3334 if (pmc_can_allocate_row(n, mode) == 0 && 3335 pmc_can_allocate_rowindex( 3336 curthread->td_proc, n, 3337 PMC_CPU_ANY) == 0 && 3338 pcd->pcd_allocate_pmc(curthread->td_oncpu, 3339 adjri, pmc, &pa) == 0) 3340 break; 3341 } 3342 } 3343 3344 #undef PMC_IS_UNALLOCATED 3345 #undef PMC_IS_SHAREABLE_PMC 3346 3347 pmc_restore_cpu_binding(&pb); 3348 3349 if (n == (int) md->pmd_npmc) { 3350 pmc_destroy_pmc_descriptor(pmc); 3351 free(pmc, M_PMC); 3352 pmc = NULL; 3353 error = EINVAL; 3354 break; 3355 } 3356 3357 /* Fill in the correct value in the ID field */ 3358 pmc->pm_id = PMC_ID_MAKE_ID(cpu,mode,pa.pm_class,n); 3359 3360 PMCDBG(PMC,ALL,2, "ev=%d class=%d mode=%d n=%d -> pmcid=%x", 3361 pmc->pm_event, pa.pm_class, mode, n, pmc->pm_id); 3362 3363 /* Process mode PMCs with logging enabled need log files */ 3364 if (pmc->pm_flags & (PMC_F_LOG_PROCEXIT | PMC_F_LOG_PROCCSW)) 3365 pmc->pm_flags |= PMC_F_NEEDS_LOGFILE; 3366 3367 /* All system mode sampling PMCs require a log file */ 3368 if (PMC_IS_SAMPLING_MODE(mode) && PMC_IS_SYSTEM_MODE(mode)) 3369 pmc->pm_flags |= PMC_F_NEEDS_LOGFILE; 3370 3371 /* 3372 * Configure global pmc's immediately 3373 */ 3374 3375 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pmc))) { 3376 3377 pmc_save_cpu_binding(&pb); 3378 pmc_select_cpu(cpu); 3379 3380 phw = pmc_pcpu[cpu]->pc_hwpmcs[n]; 3381 pcd = pmc_ri_to_classdep(md, n, &adjri); 3382 3383 if ((phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0 || 3384 (error = pcd->pcd_config_pmc(cpu, adjri, pmc)) != 0) { 3385 (void) pcd->pcd_release_pmc(cpu, adjri, pmc); 3386 pmc_destroy_pmc_descriptor(pmc); 3387 free(pmc, M_PMC); 3388 pmc = NULL; 3389 pmc_restore_cpu_binding(&pb); 3390 error = EPERM; 3391 break; 3392 } 3393 3394 pmc_restore_cpu_binding(&pb); 3395 } 3396 3397 pmc->pm_state = PMC_STATE_ALLOCATED; 3398 3399 /* 3400 * mark row disposition 3401 */ 3402 3403 if (PMC_IS_SYSTEM_MODE(mode)) 3404 PMC_MARK_ROW_STANDALONE(n); 3405 else 3406 PMC_MARK_ROW_THREAD(n); 3407 3408 /* 3409 * Register this PMC with the current thread as its owner. 3410 */ 3411 3412 if ((error = 3413 pmc_register_owner(curthread->td_proc, pmc)) != 0) { 3414 pmc_release_pmc_descriptor(pmc); 3415 free(pmc, M_PMC); 3416 pmc = NULL; 3417 break; 3418 } 3419 3420 /* 3421 * Return the allocated index. 3422 */ 3423 3424 pa.pm_pmcid = pmc->pm_id; 3425 3426 error = copyout(&pa, arg, sizeof(pa)); 3427 } 3428 break; 3429 3430 3431 /* 3432 * Attach a PMC to a process. 3433 */ 3434 3435 case PMC_OP_PMCATTACH: 3436 { 3437 struct pmc *pm; 3438 struct proc *p; 3439 struct pmc_op_pmcattach a; 3440 3441 sx_assert(&pmc_sx, SX_XLOCKED); 3442 3443 if ((error = copyin(arg, &a, sizeof(a))) != 0) 3444 break; 3445 3446 if (a.pm_pid < 0) { 3447 error = EINVAL; 3448 break; 3449 } else if (a.pm_pid == 0) 3450 a.pm_pid = td->td_proc->p_pid; 3451 3452 if ((error = pmc_find_pmc(a.pm_pmc, &pm)) != 0) 3453 break; 3454 3455 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) { 3456 error = EINVAL; 3457 break; 3458 } 3459 3460 /* PMCs may be (re)attached only when allocated or stopped */ 3461 if (pm->pm_state == PMC_STATE_RUNNING) { 3462 error = EBUSY; 3463 break; 3464 } else if (pm->pm_state != PMC_STATE_ALLOCATED && 3465 pm->pm_state != PMC_STATE_STOPPED) { 3466 error = EINVAL; 3467 break; 3468 } 3469 3470 /* lookup pid */ 3471 if ((p = pfind(a.pm_pid)) == NULL) { 3472 error = ESRCH; 3473 break; 3474 } 3475 3476 /* 3477 * Ignore processes that are working on exiting. 3478 */ 3479 if (p->p_flag & P_WEXIT) { 3480 error = ESRCH; 3481 PROC_UNLOCK(p); /* pfind() returns a locked process */ 3482 break; 3483 } 3484 3485 /* 3486 * we are allowed to attach a PMC to a process if 3487 * we can debug it. 3488 */ 3489 error = p_candebug(curthread, p); 3490 3491 PROC_UNLOCK(p); 3492 3493 if (error == 0) 3494 error = pmc_attach_process(p, pm); 3495 } 3496 break; 3497 3498 3499 /* 3500 * Detach an attached PMC from a process. 3501 */ 3502 3503 case PMC_OP_PMCDETACH: 3504 { 3505 struct pmc *pm; 3506 struct proc *p; 3507 struct pmc_op_pmcattach a; 3508 3509 if ((error = copyin(arg, &a, sizeof(a))) != 0) 3510 break; 3511 3512 if (a.pm_pid < 0) { 3513 error = EINVAL; 3514 break; 3515 } else if (a.pm_pid == 0) 3516 a.pm_pid = td->td_proc->p_pid; 3517 3518 if ((error = pmc_find_pmc(a.pm_pmc, &pm)) != 0) 3519 break; 3520 3521 if ((p = pfind(a.pm_pid)) == NULL) { 3522 error = ESRCH; 3523 break; 3524 } 3525 3526 /* 3527 * Treat processes that are in the process of exiting 3528 * as if they were not present. 3529 */ 3530 3531 if (p->p_flag & P_WEXIT) 3532 error = ESRCH; 3533 3534 PROC_UNLOCK(p); /* pfind() returns a locked process */ 3535 3536 if (error == 0) 3537 error = pmc_detach_process(p, pm); 3538 } 3539 break; 3540 3541 3542 /* 3543 * Retrieve the MSR number associated with the counter 3544 * 'pmc_id'. This allows processes to directly use RDPMC 3545 * instructions to read their PMCs, without the overhead of a 3546 * system call. 3547 */ 3548 3549 case PMC_OP_PMCGETMSR: 3550 { 3551 int adjri, ri; 3552 struct pmc *pm; 3553 struct pmc_target *pt; 3554 struct pmc_op_getmsr gm; 3555 struct pmc_classdep *pcd; 3556 3557 PMC_DOWNGRADE_SX(); 3558 3559 if ((error = copyin(arg, &gm, sizeof(gm))) != 0) 3560 break; 3561 3562 if ((error = pmc_find_pmc(gm.pm_pmcid, &pm)) != 0) 3563 break; 3564 3565 /* 3566 * The allocated PMC has to be a process virtual PMC, 3567 * i.e., of type MODE_T[CS]. Global PMCs can only be 3568 * read using the PMCREAD operation since they may be 3569 * allocated on a different CPU than the one we could 3570 * be running on at the time of the RDPMC instruction. 3571 * 3572 * The GETMSR operation is not allowed for PMCs that 3573 * are inherited across processes. 3574 */ 3575 3576 if (!PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)) || 3577 (pm->pm_flags & PMC_F_DESCENDANTS)) { 3578 error = EINVAL; 3579 break; 3580 } 3581 3582 /* 3583 * It only makes sense to use a RDPMC (or its 3584 * equivalent instruction on non-x86 architectures) on 3585 * a process that has allocated and attached a PMC to 3586 * itself. Conversely the PMC is only allowed to have 3587 * one process attached to it -- its owner. 3588 */ 3589 3590 if ((pt = LIST_FIRST(&pm->pm_targets)) == NULL || 3591 LIST_NEXT(pt, pt_next) != NULL || 3592 pt->pt_process->pp_proc != pm->pm_owner->po_owner) { 3593 error = EINVAL; 3594 break; 3595 } 3596 3597 ri = PMC_TO_ROWINDEX(pm); 3598 pcd = pmc_ri_to_classdep(md, ri, &adjri); 3599 3600 /* PMC class has no 'GETMSR' support */ 3601 if (pcd->pcd_get_msr == NULL) { 3602 error = ENOSYS; 3603 break; 3604 } 3605 3606 if ((error = (*pcd->pcd_get_msr)(adjri, &gm.pm_msr)) < 0) 3607 break; 3608 3609 if ((error = copyout(&gm, arg, sizeof(gm))) < 0) 3610 break; 3611 3612 /* 3613 * Mark our process as using MSRs. Update machine 3614 * state using a forced context switch. 3615 */ 3616 3617 pt->pt_process->pp_flags |= PMC_PP_ENABLE_MSR_ACCESS; 3618 pmc_force_context_switch(); 3619 3620 } 3621 break; 3622 3623 /* 3624 * Release an allocated PMC 3625 */ 3626 3627 case PMC_OP_PMCRELEASE: 3628 { 3629 pmc_id_t pmcid; 3630 struct pmc *pm; 3631 struct pmc_owner *po; 3632 struct pmc_op_simple sp; 3633 3634 /* 3635 * Find PMC pointer for the named PMC. 3636 * 3637 * Use pmc_release_pmc_descriptor() to switch off the 3638 * PMC, remove all its target threads, and remove the 3639 * PMC from its owner's list. 3640 * 3641 * Remove the owner record if this is the last PMC 3642 * owned. 3643 * 3644 * Free up space. 3645 */ 3646 3647 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 3648 break; 3649 3650 pmcid = sp.pm_pmcid; 3651 3652 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 3653 break; 3654 3655 po = pm->pm_owner; 3656 pmc_release_pmc_descriptor(pm); 3657 pmc_maybe_remove_owner(po); 3658 3659 free(pm, M_PMC); 3660 } 3661 break; 3662 3663 3664 /* 3665 * Read and/or write a PMC. 3666 */ 3667 3668 case PMC_OP_PMCRW: 3669 { 3670 int adjri; 3671 struct pmc *pm; 3672 uint32_t cpu, ri; 3673 pmc_value_t oldvalue; 3674 struct pmc_binding pb; 3675 struct pmc_op_pmcrw prw; 3676 struct pmc_classdep *pcd; 3677 struct pmc_op_pmcrw *pprw; 3678 3679 PMC_DOWNGRADE_SX(); 3680 3681 if ((error = copyin(arg, &prw, sizeof(prw))) != 0) 3682 break; 3683 3684 ri = 0; 3685 PMCDBG(PMC,OPS,1, "rw id=%d flags=0x%x", prw.pm_pmcid, 3686 prw.pm_flags); 3687 3688 /* must have at least one flag set */ 3689 if ((prw.pm_flags & (PMC_F_OLDVALUE|PMC_F_NEWVALUE)) == 0) { 3690 error = EINVAL; 3691 break; 3692 } 3693 3694 /* locate pmc descriptor */ 3695 if ((error = pmc_find_pmc(prw.pm_pmcid, &pm)) != 0) 3696 break; 3697 3698 /* Can't read a PMC that hasn't been started. */ 3699 if (pm->pm_state != PMC_STATE_ALLOCATED && 3700 pm->pm_state != PMC_STATE_STOPPED && 3701 pm->pm_state != PMC_STATE_RUNNING) { 3702 error = EINVAL; 3703 break; 3704 } 3705 3706 /* writing a new value is allowed only for 'STOPPED' pmcs */ 3707 if (pm->pm_state == PMC_STATE_RUNNING && 3708 (prw.pm_flags & PMC_F_NEWVALUE)) { 3709 error = EBUSY; 3710 break; 3711 } 3712 3713 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) { 3714 3715 /* 3716 * If this PMC is attached to its owner (i.e., 3717 * the process requesting this operation) and 3718 * is running, then attempt to get an 3719 * upto-date reading from hardware for a READ. 3720 * Writes are only allowed when the PMC is 3721 * stopped, so only update the saved value 3722 * field. 3723 * 3724 * If the PMC is not running, or is not 3725 * attached to its owner, read/write to the 3726 * savedvalue field. 3727 */ 3728 3729 ri = PMC_TO_ROWINDEX(pm); 3730 pcd = pmc_ri_to_classdep(md, ri, &adjri); 3731 3732 mtx_pool_lock_spin(pmc_mtxpool, pm); 3733 cpu = curthread->td_oncpu; 3734 3735 if (prw.pm_flags & PMC_F_OLDVALUE) { 3736 if ((pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) && 3737 (pm->pm_state == PMC_STATE_RUNNING)) 3738 error = (*pcd->pcd_read_pmc)(cpu, adjri, 3739 &oldvalue); 3740 else 3741 oldvalue = pm->pm_gv.pm_savedvalue; 3742 } 3743 if (prw.pm_flags & PMC_F_NEWVALUE) 3744 pm->pm_gv.pm_savedvalue = prw.pm_value; 3745 3746 mtx_pool_unlock_spin(pmc_mtxpool, pm); 3747 3748 } else { /* System mode PMCs */ 3749 cpu = PMC_TO_CPU(pm); 3750 ri = PMC_TO_ROWINDEX(pm); 3751 pcd = pmc_ri_to_classdep(md, ri, &adjri); 3752 3753 if (!pmc_cpu_is_active(cpu)) { 3754 error = ENXIO; 3755 break; 3756 } 3757 3758 /* move this thread to CPU 'cpu' */ 3759 pmc_save_cpu_binding(&pb); 3760 pmc_select_cpu(cpu); 3761 3762 critical_enter(); 3763 /* save old value */ 3764 if (prw.pm_flags & PMC_F_OLDVALUE) 3765 if ((error = (*pcd->pcd_read_pmc)(cpu, adjri, 3766 &oldvalue))) 3767 goto error; 3768 /* write out new value */ 3769 if (prw.pm_flags & PMC_F_NEWVALUE) 3770 error = (*pcd->pcd_write_pmc)(cpu, adjri, 3771 prw.pm_value); 3772 error: 3773 critical_exit(); 3774 pmc_restore_cpu_binding(&pb); 3775 if (error) 3776 break; 3777 } 3778 3779 pprw = (struct pmc_op_pmcrw *) arg; 3780 3781 #ifdef DEBUG 3782 if (prw.pm_flags & PMC_F_NEWVALUE) 3783 PMCDBG(PMC,OPS,2, "rw id=%d new %jx -> old %jx", 3784 ri, prw.pm_value, oldvalue); 3785 else if (prw.pm_flags & PMC_F_OLDVALUE) 3786 PMCDBG(PMC,OPS,2, "rw id=%d -> old %jx", ri, oldvalue); 3787 #endif 3788 3789 /* return old value if requested */ 3790 if (prw.pm_flags & PMC_F_OLDVALUE) 3791 if ((error = copyout(&oldvalue, &pprw->pm_value, 3792 sizeof(prw.pm_value)))) 3793 break; 3794 3795 } 3796 break; 3797 3798 3799 /* 3800 * Set the sampling rate for a sampling mode PMC and the 3801 * initial count for a counting mode PMC. 3802 */ 3803 3804 case PMC_OP_PMCSETCOUNT: 3805 { 3806 struct pmc *pm; 3807 struct pmc_op_pmcsetcount sc; 3808 3809 PMC_DOWNGRADE_SX(); 3810 3811 if ((error = copyin(arg, &sc, sizeof(sc))) != 0) 3812 break; 3813 3814 if ((error = pmc_find_pmc(sc.pm_pmcid, &pm)) != 0) 3815 break; 3816 3817 if (pm->pm_state == PMC_STATE_RUNNING) { 3818 error = EBUSY; 3819 break; 3820 } 3821 3822 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 3823 pm->pm_sc.pm_reloadcount = sc.pm_count; 3824 else 3825 pm->pm_sc.pm_initial = sc.pm_count; 3826 } 3827 break; 3828 3829 3830 /* 3831 * Start a PMC. 3832 */ 3833 3834 case PMC_OP_PMCSTART: 3835 { 3836 pmc_id_t pmcid; 3837 struct pmc *pm; 3838 struct pmc_op_simple sp; 3839 3840 sx_assert(&pmc_sx, SX_XLOCKED); 3841 3842 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 3843 break; 3844 3845 pmcid = sp.pm_pmcid; 3846 3847 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 3848 break; 3849 3850 KASSERT(pmcid == pm->pm_id, 3851 ("[pmc,%d] pmcid %x != id %x", __LINE__, 3852 pm->pm_id, pmcid)); 3853 3854 if (pm->pm_state == PMC_STATE_RUNNING) /* already running */ 3855 break; 3856 else if (pm->pm_state != PMC_STATE_STOPPED && 3857 pm->pm_state != PMC_STATE_ALLOCATED) { 3858 error = EINVAL; 3859 break; 3860 } 3861 3862 error = pmc_start(pm); 3863 } 3864 break; 3865 3866 3867 /* 3868 * Stop a PMC. 3869 */ 3870 3871 case PMC_OP_PMCSTOP: 3872 { 3873 pmc_id_t pmcid; 3874 struct pmc *pm; 3875 struct pmc_op_simple sp; 3876 3877 PMC_DOWNGRADE_SX(); 3878 3879 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 3880 break; 3881 3882 pmcid = sp.pm_pmcid; 3883 3884 /* 3885 * Mark the PMC as inactive and invoke the MD stop 3886 * routines if needed. 3887 */ 3888 3889 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 3890 break; 3891 3892 KASSERT(pmcid == pm->pm_id, 3893 ("[pmc,%d] pmc id %x != pmcid %x", __LINE__, 3894 pm->pm_id, pmcid)); 3895 3896 if (pm->pm_state == PMC_STATE_STOPPED) /* already stopped */ 3897 break; 3898 else if (pm->pm_state != PMC_STATE_RUNNING) { 3899 error = EINVAL; 3900 break; 3901 } 3902 3903 error = pmc_stop(pm); 3904 } 3905 break; 3906 3907 3908 /* 3909 * Write a user supplied value to the log file. 3910 */ 3911 3912 case PMC_OP_WRITELOG: 3913 { 3914 struct pmc_op_writelog wl; 3915 struct pmc_owner *po; 3916 3917 PMC_DOWNGRADE_SX(); 3918 3919 if ((error = copyin(arg, &wl, sizeof(wl))) != 0) 3920 break; 3921 3922 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 3923 error = EINVAL; 3924 break; 3925 } 3926 3927 if ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) { 3928 error = EINVAL; 3929 break; 3930 } 3931 3932 error = pmclog_process_userlog(po, &wl); 3933 } 3934 break; 3935 3936 3937 default: 3938 error = EINVAL; 3939 break; 3940 } 3941 3942 if (is_sx_locked != 0) { 3943 if (is_sx_downgraded) 3944 sx_sunlock(&pmc_sx); 3945 else 3946 sx_xunlock(&pmc_sx); 3947 } 3948 3949 if (error) 3950 atomic_add_int(&pmc_stats.pm_syscall_errors, 1); 3951 3952 PICKUP_GIANT(); 3953 3954 return error; 3955 } 3956 3957 /* 3958 * Helper functions 3959 */ 3960 3961 3962 /* 3963 * Mark the thread as needing callchain capture and post an AST. The 3964 * actual callchain capture will be done in a context where it is safe 3965 * to take page faults. 3966 */ 3967 3968 static void 3969 pmc_post_callchain_callback(void) 3970 { 3971 struct thread *td; 3972 3973 td = curthread; 3974 3975 KASSERT((td->td_pflags & TDP_CALLCHAIN) == 0, 3976 ("[pmc,%d] thread %p already marked for callchain capture", 3977 __LINE__, (void *) td)); 3978 3979 /* 3980 * Mark this thread as needing callchain capture. 3981 * `td->td_pflags' will be safe to touch because this thread 3982 * was in user space when it was interrupted. 3983 */ 3984 td->td_pflags |= TDP_CALLCHAIN; 3985 3986 /* 3987 * Don't let this thread migrate between CPUs until callchain 3988 * capture completes. 3989 */ 3990 sched_pin(); 3991 3992 return; 3993 } 3994 3995 /* 3996 * Interrupt processing. 3997 * 3998 * Find a free slot in the per-cpu array of samples and capture the 3999 * current callchain there. If a sample was successfully added, a bit 4000 * is set in mask 'pmc_cpumask' denoting that the DO_SAMPLES hook 4001 * needs to be invoked from the clock handler. 4002 * 4003 * This function is meant to be called from an NMI handler. It cannot 4004 * use any of the locking primitives supplied by the OS. 4005 */ 4006 4007 int 4008 pmc_process_interrupt(int cpu, struct pmc *pm, struct trapframe *tf, 4009 int inuserspace) 4010 { 4011 int error, callchaindepth; 4012 struct thread *td; 4013 struct pmc_sample *ps; 4014 struct pmc_samplebuffer *psb; 4015 4016 error = 0; 4017 4018 /* 4019 * Allocate space for a sample buffer. 4020 */ 4021 psb = pmc_pcpu[cpu]->pc_sb; 4022 4023 ps = psb->ps_write; 4024 if (ps->ps_nsamples) { /* in use, reader hasn't caught up */ 4025 pm->pm_stalled = 1; 4026 atomic_add_int(&pmc_stats.pm_intr_bufferfull, 1); 4027 PMCDBG(SAM,INT,1,"(spc) cpu=%d pm=%p tf=%p um=%d wr=%d rd=%d", 4028 cpu, pm, (void *) tf, inuserspace, 4029 (int) (psb->ps_write - psb->ps_samples), 4030 (int) (psb->ps_read - psb->ps_samples)); 4031 error = ENOMEM; 4032 goto done; 4033 } 4034 4035 4036 /* Fill in entry. */ 4037 PMCDBG(SAM,INT,1,"cpu=%d pm=%p tf=%p um=%d wr=%d rd=%d", cpu, pm, 4038 (void *) tf, inuserspace, 4039 (int) (psb->ps_write - psb->ps_samples), 4040 (int) (psb->ps_read - psb->ps_samples)); 4041 4042 KASSERT(pm->pm_runcount >= 0, 4043 ("[pmc,%d] pm=%p runcount %d", __LINE__, (void *) pm, 4044 pm->pm_runcount)); 4045 4046 atomic_add_rel_32(&pm->pm_runcount, 1); /* hold onto PMC */ 4047 ps->ps_pmc = pm; 4048 if ((td = curthread) && td->td_proc) 4049 ps->ps_pid = td->td_proc->p_pid; 4050 else 4051 ps->ps_pid = -1; 4052 ps->ps_cpu = cpu; 4053 ps->ps_td = td; 4054 ps->ps_flags = inuserspace ? PMC_CC_F_USERSPACE : 0; 4055 4056 callchaindepth = (pm->pm_flags & PMC_F_CALLCHAIN) ? 4057 pmc_callchaindepth : 1; 4058 4059 if (callchaindepth == 1) 4060 ps->ps_pc[0] = PMC_TRAPFRAME_TO_PC(tf); 4061 else { 4062 /* 4063 * Kernel stack traversals can be done immediately, 4064 * while we defer to an AST for user space traversals. 4065 */ 4066 if (!inuserspace) 4067 callchaindepth = 4068 pmc_save_kernel_callchain(ps->ps_pc, 4069 callchaindepth, tf); 4070 else { 4071 pmc_post_callchain_callback(); 4072 callchaindepth = PMC_SAMPLE_INUSE; 4073 } 4074 } 4075 4076 ps->ps_nsamples = callchaindepth; /* mark entry as in use */ 4077 4078 /* increment write pointer, modulo ring buffer size */ 4079 ps++; 4080 if (ps == psb->ps_fence) 4081 psb->ps_write = psb->ps_samples; 4082 else 4083 psb->ps_write = ps; 4084 4085 done: 4086 /* mark CPU as needing processing */ 4087 atomic_set_rel_int(&pmc_cpumask, (1 << cpu)); 4088 4089 return (error); 4090 } 4091 4092 /* 4093 * Capture a user call chain. This function will be called from ast() 4094 * before control returns to userland and before the process gets 4095 * rescheduled. 4096 */ 4097 4098 static void 4099 pmc_capture_user_callchain(int cpu, struct trapframe *tf) 4100 { 4101 int i; 4102 struct pmc *pm; 4103 struct thread *td; 4104 struct pmc_sample *ps; 4105 struct pmc_samplebuffer *psb; 4106 #ifdef INVARIANTS 4107 int ncallchains; 4108 #endif 4109 4110 sched_unpin(); /* Can migrate safely now. */ 4111 4112 psb = pmc_pcpu[cpu]->pc_sb; 4113 td = curthread; 4114 4115 KASSERT(td->td_pflags & TDP_CALLCHAIN, 4116 ("[pmc,%d] Retrieving callchain for thread that doesn't want it", 4117 __LINE__)); 4118 4119 #ifdef INVARIANTS 4120 ncallchains = 0; 4121 #endif 4122 4123 /* 4124 * Iterate through all deferred callchain requests. 4125 */ 4126 4127 ps = psb->ps_samples; 4128 for (i = 0; i < pmc_nsamples; i++, ps++) { 4129 4130 if (ps->ps_nsamples != PMC_SAMPLE_INUSE) 4131 continue; 4132 if (ps->ps_td != td) 4133 continue; 4134 4135 KASSERT(ps->ps_cpu == cpu, 4136 ("[pmc,%d] cpu mismatch ps_cpu=%d pcpu=%d", __LINE__, 4137 ps->ps_cpu, PCPU_GET(cpuid))); 4138 4139 pm = ps->ps_pmc; 4140 4141 KASSERT(pm->pm_flags & PMC_F_CALLCHAIN, 4142 ("[pmc,%d] Retrieving callchain for PMC that doesn't " 4143 "want it", __LINE__)); 4144 4145 KASSERT(pm->pm_runcount > 0, 4146 ("[pmc,%d] runcount %d", __LINE__, pm->pm_runcount)); 4147 4148 /* 4149 * Retrieve the callchain and mark the sample buffer 4150 * as 'processable' by the timer tick sweep code. 4151 */ 4152 ps->ps_nsamples = pmc_save_user_callchain(ps->ps_pc, 4153 pmc_callchaindepth, tf); 4154 4155 #ifdef INVARIANTS 4156 ncallchains++; 4157 #endif 4158 4159 } 4160 4161 KASSERT(ncallchains > 0, 4162 ("[pmc,%d] cpu %d didn't find a sample to collect", __LINE__, 4163 cpu)); 4164 4165 return; 4166 } 4167 4168 4169 /* 4170 * Process saved PC samples. 4171 */ 4172 4173 static void 4174 pmc_process_samples(int cpu) 4175 { 4176 struct pmc *pm; 4177 int adjri, n; 4178 struct thread *td; 4179 struct pmc_owner *po; 4180 struct pmc_sample *ps; 4181 struct pmc_classdep *pcd; 4182 struct pmc_samplebuffer *psb; 4183 4184 KASSERT(PCPU_GET(cpuid) == cpu, 4185 ("[pmc,%d] not on the correct CPU pcpu=%d cpu=%d", __LINE__, 4186 PCPU_GET(cpuid), cpu)); 4187 4188 psb = pmc_pcpu[cpu]->pc_sb; 4189 4190 for (n = 0; n < pmc_nsamples; n++) { /* bound on #iterations */ 4191 4192 ps = psb->ps_read; 4193 if (ps->ps_nsamples == PMC_SAMPLE_FREE) 4194 break; 4195 if (ps->ps_nsamples == PMC_SAMPLE_INUSE) { 4196 /* Need a rescan at a later time. */ 4197 atomic_set_rel_int(&pmc_cpumask, (1 << cpu)); 4198 break; 4199 } 4200 4201 pm = ps->ps_pmc; 4202 4203 KASSERT(pm->pm_runcount > 0, 4204 ("[pmc,%d] pm=%p runcount %d", __LINE__, (void *) pm, 4205 pm->pm_runcount)); 4206 4207 po = pm->pm_owner; 4208 4209 KASSERT(PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)), 4210 ("[pmc,%d] pmc=%p non-sampling mode=%d", __LINE__, 4211 pm, PMC_TO_MODE(pm))); 4212 4213 /* Ignore PMCs that have been switched off */ 4214 if (pm->pm_state != PMC_STATE_RUNNING) 4215 goto entrydone; 4216 4217 PMCDBG(SAM,OPS,1,"cpu=%d pm=%p n=%d fl=%x wr=%d rd=%d", cpu, 4218 pm, ps->ps_nsamples, ps->ps_flags, 4219 (int) (psb->ps_write - psb->ps_samples), 4220 (int) (psb->ps_read - psb->ps_samples)); 4221 4222 /* 4223 * If this is a process-mode PMC that is attached to 4224 * its owner, and if the PC is in user mode, update 4225 * profiling statistics like timer-based profiling 4226 * would have done. 4227 */ 4228 if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) { 4229 if (ps->ps_flags & PMC_CC_F_USERSPACE) { 4230 td = FIRST_THREAD_IN_PROC(po->po_owner); 4231 addupc_intr(td, ps->ps_pc[0], 1); 4232 } 4233 goto entrydone; 4234 } 4235 4236 /* 4237 * Otherwise, this is either a sampling mode PMC that 4238 * is attached to a different process than its owner, 4239 * or a system-wide sampling PMC. Dispatch a log 4240 * entry to the PMC's owner process. 4241 */ 4242 4243 pmclog_process_callchain(pm, ps); 4244 4245 entrydone: 4246 ps->ps_nsamples = 0; /* mark entry as free */ 4247 atomic_subtract_rel_32(&pm->pm_runcount, 1); 4248 4249 /* increment read pointer, modulo sample size */ 4250 if (++ps == psb->ps_fence) 4251 psb->ps_read = psb->ps_samples; 4252 else 4253 psb->ps_read = ps; 4254 } 4255 4256 atomic_add_int(&pmc_stats.pm_log_sweeps, 1); 4257 4258 /* Do not re-enable stalled PMCs if we failed to process any samples */ 4259 if (n == 0) 4260 return; 4261 4262 /* 4263 * Restart any stalled sampling PMCs on this CPU. 4264 * 4265 * If the NMI handler sets the pm_stalled field of a PMC after 4266 * the check below, we'll end up processing the stalled PMC at 4267 * the next hardclock tick. 4268 */ 4269 for (n = 0; n < md->pmd_npmc; n++) { 4270 pcd = pmc_ri_to_classdep(md, n, &adjri); 4271 KASSERT(pcd != NULL, 4272 ("[pmc,%d] null pcd ri=%d", __LINE__, n)); 4273 (void) (*pcd->pcd_get_config)(cpu,adjri,&pm); 4274 4275 if (pm == NULL || /* !cfg'ed */ 4276 pm->pm_state != PMC_STATE_RUNNING || /* !active */ 4277 !PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)) || /* !sampling */ 4278 pm->pm_stalled == 0) /* !stalled */ 4279 continue; 4280 4281 pm->pm_stalled = 0; 4282 (*pcd->pcd_start_pmc)(cpu, adjri); 4283 } 4284 } 4285 4286 /* 4287 * Event handlers. 4288 */ 4289 4290 /* 4291 * Handle a process exit. 4292 * 4293 * Remove this process from all hash tables. If this process 4294 * owned any PMCs, turn off those PMCs and deallocate them, 4295 * removing any associations with target processes. 4296 * 4297 * This function will be called by the last 'thread' of a 4298 * process. 4299 * 4300 * XXX This eventhandler gets called early in the exit process. 4301 * Consider using a 'hook' invocation from thread_exit() or equivalent 4302 * spot. Another negative is that kse_exit doesn't seem to call 4303 * exit1() [??]. 4304 * 4305 */ 4306 4307 static void 4308 pmc_process_exit(void *arg __unused, struct proc *p) 4309 { 4310 struct pmc *pm; 4311 int adjri, cpu; 4312 unsigned int ri; 4313 int is_using_hwpmcs; 4314 struct pmc_owner *po; 4315 struct pmc_process *pp; 4316 struct pmc_classdep *pcd; 4317 pmc_value_t newvalue, tmp; 4318 4319 PROC_LOCK(p); 4320 is_using_hwpmcs = p->p_flag & P_HWPMC; 4321 PROC_UNLOCK(p); 4322 4323 /* 4324 * Log a sysexit event to all SS PMC owners. 4325 */ 4326 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 4327 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 4328 pmclog_process_sysexit(po, p->p_pid); 4329 4330 if (!is_using_hwpmcs) 4331 return; 4332 4333 PMC_GET_SX_XLOCK(); 4334 PMCDBG(PRC,EXT,1,"process-exit proc=%p (%d, %s)", p, p->p_pid, 4335 p->p_comm); 4336 4337 /* 4338 * Since this code is invoked by the last thread in an exiting 4339 * process, we would have context switched IN at some prior 4340 * point. However, with PREEMPTION, kernel mode context 4341 * switches may happen any time, so we want to disable a 4342 * context switch OUT till we get any PMCs targetting this 4343 * process off the hardware. 4344 * 4345 * We also need to atomically remove this process' 4346 * entry from our target process hash table, using 4347 * PMC_FLAG_REMOVE. 4348 */ 4349 PMCDBG(PRC,EXT,1, "process-exit proc=%p (%d, %s)", p, p->p_pid, 4350 p->p_comm); 4351 4352 critical_enter(); /* no preemption */ 4353 4354 cpu = curthread->td_oncpu; 4355 4356 if ((pp = pmc_find_process_descriptor(p, 4357 PMC_FLAG_REMOVE)) != NULL) { 4358 4359 PMCDBG(PRC,EXT,2, 4360 "process-exit proc=%p pmc-process=%p", p, pp); 4361 4362 /* 4363 * The exiting process could the target of 4364 * some PMCs which will be running on 4365 * currently executing CPU. 4366 * 4367 * We need to turn these PMCs off like we 4368 * would do at context switch OUT time. 4369 */ 4370 for (ri = 0; ri < md->pmd_npmc; ri++) { 4371 4372 /* 4373 * Pick up the pmc pointer from hardware 4374 * state similar to the CSW_OUT code. 4375 */ 4376 pm = NULL; 4377 4378 pcd = pmc_ri_to_classdep(md, ri, &adjri); 4379 4380 (void) (*pcd->pcd_get_config)(cpu, adjri, &pm); 4381 4382 PMCDBG(PRC,EXT,2, "ri=%d pm=%p", ri, pm); 4383 4384 if (pm == NULL || 4385 !PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) 4386 continue; 4387 4388 PMCDBG(PRC,EXT,2, "ppmcs[%d]=%p pm=%p " 4389 "state=%d", ri, pp->pp_pmcs[ri].pp_pmc, 4390 pm, pm->pm_state); 4391 4392 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 4393 ("[pmc,%d] ri mismatch pmc(%d) ri(%d)", 4394 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 4395 4396 KASSERT(pm == pp->pp_pmcs[ri].pp_pmc, 4397 ("[pmc,%d] pm %p != pp_pmcs[%d] %p", 4398 __LINE__, pm, ri, pp->pp_pmcs[ri].pp_pmc)); 4399 4400 (void) pcd->pcd_stop_pmc(cpu, adjri); 4401 4402 KASSERT(pm->pm_runcount > 0, 4403 ("[pmc,%d] bad runcount ri %d rc %d", 4404 __LINE__, ri, pm->pm_runcount)); 4405 4406 /* Stop hardware only if it is actually running */ 4407 if (pm->pm_state == PMC_STATE_RUNNING && 4408 pm->pm_stalled == 0) { 4409 pcd->pcd_read_pmc(cpu, adjri, &newvalue); 4410 tmp = newvalue - 4411 PMC_PCPU_SAVED(cpu,ri); 4412 4413 mtx_pool_lock_spin(pmc_mtxpool, pm); 4414 pm->pm_gv.pm_savedvalue += tmp; 4415 pp->pp_pmcs[ri].pp_pmcval += tmp; 4416 mtx_pool_unlock_spin(pmc_mtxpool, pm); 4417 } 4418 4419 atomic_subtract_rel_32(&pm->pm_runcount,1); 4420 4421 KASSERT((int) pm->pm_runcount >= 0, 4422 ("[pmc,%d] runcount is %d", __LINE__, ri)); 4423 4424 (void) pcd->pcd_config_pmc(cpu, adjri, NULL); 4425 } 4426 4427 /* 4428 * Inform the MD layer of this pseudo "context switch 4429 * out" 4430 */ 4431 (void) md->pmd_switch_out(pmc_pcpu[cpu], pp); 4432 4433 critical_exit(); /* ok to be pre-empted now */ 4434 4435 /* 4436 * Unlink this process from the PMCs that are 4437 * targetting it. This will send a signal to 4438 * all PMC owner's whose PMCs are orphaned. 4439 * 4440 * Log PMC value at exit time if requested. 4441 */ 4442 for (ri = 0; ri < md->pmd_npmc; ri++) 4443 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) { 4444 if (pm->pm_flags & PMC_F_NEEDS_LOGFILE && 4445 PMC_IS_COUNTING_MODE(PMC_TO_MODE(pm))) 4446 pmclog_process_procexit(pm, pp); 4447 pmc_unlink_target_process(pm, pp); 4448 } 4449 free(pp, M_PMC); 4450 4451 } else 4452 critical_exit(); /* pp == NULL */ 4453 4454 4455 /* 4456 * If the process owned PMCs, free them up and free up 4457 * memory. 4458 */ 4459 if ((po = pmc_find_owner_descriptor(p)) != NULL) { 4460 pmc_remove_owner(po); 4461 pmc_destroy_owner_descriptor(po); 4462 } 4463 4464 sx_xunlock(&pmc_sx); 4465 } 4466 4467 /* 4468 * Handle a process fork. 4469 * 4470 * If the parent process 'p1' is under HWPMC monitoring, then copy 4471 * over any attached PMCs that have 'do_descendants' semantics. 4472 */ 4473 4474 static void 4475 pmc_process_fork(void *arg __unused, struct proc *p1, struct proc *newproc, 4476 int flags) 4477 { 4478 int is_using_hwpmcs; 4479 unsigned int ri; 4480 uint32_t do_descendants; 4481 struct pmc *pm; 4482 struct pmc_owner *po; 4483 struct pmc_process *ppnew, *ppold; 4484 4485 (void) flags; /* unused parameter */ 4486 4487 PROC_LOCK(p1); 4488 is_using_hwpmcs = p1->p_flag & P_HWPMC; 4489 PROC_UNLOCK(p1); 4490 4491 /* 4492 * If there are system-wide sampling PMCs active, we need to 4493 * log all fork events to their owner's logs. 4494 */ 4495 4496 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 4497 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 4498 pmclog_process_procfork(po, p1->p_pid, newproc->p_pid); 4499 4500 if (!is_using_hwpmcs) 4501 return; 4502 4503 PMC_GET_SX_XLOCK(); 4504 PMCDBG(PMC,FRK,1, "process-fork proc=%p (%d, %s) -> %p", p1, 4505 p1->p_pid, p1->p_comm, newproc); 4506 4507 /* 4508 * If the parent process (curthread->td_proc) is a 4509 * target of any PMCs, look for PMCs that are to be 4510 * inherited, and link these into the new process 4511 * descriptor. 4512 */ 4513 if ((ppold = pmc_find_process_descriptor(curthread->td_proc, 4514 PMC_FLAG_NONE)) == NULL) 4515 goto done; /* nothing to do */ 4516 4517 do_descendants = 0; 4518 for (ri = 0; ri < md->pmd_npmc; ri++) 4519 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL) 4520 do_descendants |= pm->pm_flags & PMC_F_DESCENDANTS; 4521 if (do_descendants == 0) /* nothing to do */ 4522 goto done; 4523 4524 /* allocate a descriptor for the new process */ 4525 if ((ppnew = pmc_find_process_descriptor(newproc, 4526 PMC_FLAG_ALLOCATE)) == NULL) 4527 goto done; 4528 4529 /* 4530 * Run through all PMCs that were targeting the old process 4531 * and which specified F_DESCENDANTS and attach them to the 4532 * new process. 4533 * 4534 * Log the fork event to all owners of PMCs attached to this 4535 * process, if not already logged. 4536 */ 4537 for (ri = 0; ri < md->pmd_npmc; ri++) 4538 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL && 4539 (pm->pm_flags & PMC_F_DESCENDANTS)) { 4540 pmc_link_target_process(pm, ppnew); 4541 po = pm->pm_owner; 4542 if (po->po_sscount == 0 && 4543 po->po_flags & PMC_PO_OWNS_LOGFILE) 4544 pmclog_process_procfork(po, p1->p_pid, 4545 newproc->p_pid); 4546 } 4547 4548 /* 4549 * Now mark the new process as being tracked by this driver. 4550 */ 4551 PROC_LOCK(newproc); 4552 newproc->p_flag |= P_HWPMC; 4553 PROC_UNLOCK(newproc); 4554 4555 done: 4556 sx_xunlock(&pmc_sx); 4557 } 4558 4559 4560 /* 4561 * initialization 4562 */ 4563 4564 static const char *pmc_name_of_pmcclass[] = { 4565 #undef __PMC_CLASS 4566 #define __PMC_CLASS(N) #N , 4567 __PMC_CLASSES() 4568 }; 4569 4570 static int 4571 pmc_initialize(void) 4572 { 4573 int c, cpu, error, n, ri; 4574 unsigned int maxcpu; 4575 struct pmc_binding pb; 4576 struct pmc_sample *ps; 4577 struct pmc_classdep *pcd; 4578 struct pmc_samplebuffer *sb; 4579 4580 md = NULL; 4581 error = 0; 4582 4583 #ifdef DEBUG 4584 /* parse debug flags first */ 4585 if (TUNABLE_STR_FETCH(PMC_SYSCTL_NAME_PREFIX "debugflags", 4586 pmc_debugstr, sizeof(pmc_debugstr))) 4587 pmc_debugflags_parse(pmc_debugstr, 4588 pmc_debugstr+strlen(pmc_debugstr)); 4589 #endif 4590 4591 PMCDBG(MOD,INI,0, "PMC Initialize (version %x)", PMC_VERSION); 4592 4593 /* check kernel version */ 4594 if (pmc_kernel_version != PMC_VERSION) { 4595 if (pmc_kernel_version == 0) 4596 printf("hwpmc: this kernel has not been compiled with " 4597 "'options HWPMC_HOOKS'.\n"); 4598 else 4599 printf("hwpmc: kernel version (0x%x) does not match " 4600 "module version (0x%x).\n", pmc_kernel_version, 4601 PMC_VERSION); 4602 return EPROGMISMATCH; 4603 } 4604 4605 /* 4606 * check sysctl parameters 4607 */ 4608 4609 if (pmc_hashsize <= 0) { 4610 (void) printf("hwpmc: tunable \"hashsize\"=%d must be " 4611 "greater than zero.\n", pmc_hashsize); 4612 pmc_hashsize = PMC_HASH_SIZE; 4613 } 4614 4615 if (pmc_nsamples <= 0 || pmc_nsamples > 65535) { 4616 (void) printf("hwpmc: tunable \"nsamples\"=%d out of " 4617 "range.\n", pmc_nsamples); 4618 pmc_nsamples = PMC_NSAMPLES; 4619 } 4620 4621 if (pmc_callchaindepth <= 0 || 4622 pmc_callchaindepth > PMC_CALLCHAIN_DEPTH_MAX) { 4623 (void) printf("hwpmc: tunable \"callchaindepth\"=%d out of " 4624 "range.\n", pmc_callchaindepth); 4625 pmc_callchaindepth = PMC_CALLCHAIN_DEPTH; 4626 } 4627 4628 md = pmc_md_initialize(); 4629 4630 if (md == NULL) 4631 return (ENOSYS); 4632 4633 KASSERT(md->pmd_nclass >= 1 && md->pmd_npmc >= 1, 4634 ("[pmc,%d] no classes or pmcs", __LINE__)); 4635 4636 /* Compute the map from row-indices to classdep pointers. */ 4637 pmc_rowindex_to_classdep = malloc(sizeof(struct pmc_classdep *) * 4638 md->pmd_npmc, M_PMC, M_WAITOK|M_ZERO); 4639 4640 for (n = 0; n < md->pmd_npmc; n++) 4641 pmc_rowindex_to_classdep[n] = NULL; 4642 for (ri = c = 0; c < md->pmd_nclass; c++) { 4643 pcd = &md->pmd_classdep[c]; 4644 for (n = 0; n < pcd->pcd_num; n++, ri++) 4645 pmc_rowindex_to_classdep[ri] = pcd; 4646 } 4647 4648 KASSERT(ri == md->pmd_npmc, 4649 ("[pmc,%d] npmc miscomputed: ri=%d, md->npmc=%d", __LINE__, 4650 ri, md->pmd_npmc)); 4651 4652 maxcpu = pmc_cpu_max(); 4653 4654 /* allocate space for the per-cpu array */ 4655 pmc_pcpu = malloc(maxcpu * sizeof(struct pmc_cpu *), M_PMC, 4656 M_WAITOK|M_ZERO); 4657 4658 /* per-cpu 'saved values' for managing process-mode PMCs */ 4659 pmc_pcpu_saved = malloc(sizeof(pmc_value_t) * maxcpu * md->pmd_npmc, 4660 M_PMC, M_WAITOK); 4661 4662 /* Perform CPU-dependent initialization. */ 4663 pmc_save_cpu_binding(&pb); 4664 error = 0; 4665 for (cpu = 0; error == 0 && cpu < maxcpu; cpu++) { 4666 if (!pmc_cpu_is_active(cpu)) 4667 continue; 4668 pmc_select_cpu(cpu); 4669 pmc_pcpu[cpu] = malloc(sizeof(struct pmc_cpu) + 4670 md->pmd_npmc * sizeof(struct pmc_hw *), M_PMC, 4671 M_WAITOK|M_ZERO); 4672 if (md->pmd_pcpu_init) 4673 error = md->pmd_pcpu_init(md, cpu); 4674 for (n = 0; error == 0 && n < md->pmd_nclass; n++) 4675 error = md->pmd_classdep[n].pcd_pcpu_init(md, cpu); 4676 } 4677 pmc_restore_cpu_binding(&pb); 4678 4679 if (error) 4680 return (error); 4681 4682 /* allocate space for the sample array */ 4683 for (cpu = 0; cpu < maxcpu; cpu++) { 4684 if (!pmc_cpu_is_active(cpu)) 4685 continue; 4686 4687 sb = malloc(sizeof(struct pmc_samplebuffer) + 4688 pmc_nsamples * sizeof(struct pmc_sample), M_PMC, 4689 M_WAITOK|M_ZERO); 4690 sb->ps_read = sb->ps_write = sb->ps_samples; 4691 sb->ps_fence = sb->ps_samples + pmc_nsamples; 4692 4693 KASSERT(pmc_pcpu[cpu] != NULL, 4694 ("[pmc,%d] cpu=%d Null per-cpu data", __LINE__, cpu)); 4695 4696 sb->ps_callchains = malloc(pmc_callchaindepth * pmc_nsamples * 4697 sizeof(uintptr_t), M_PMC, M_WAITOK|M_ZERO); 4698 4699 for (n = 0, ps = sb->ps_samples; n < pmc_nsamples; n++, ps++) 4700 ps->ps_pc = sb->ps_callchains + 4701 (n * pmc_callchaindepth); 4702 4703 pmc_pcpu[cpu]->pc_sb = sb; 4704 } 4705 4706 /* allocate space for the row disposition array */ 4707 pmc_pmcdisp = malloc(sizeof(enum pmc_mode) * md->pmd_npmc, 4708 M_PMC, M_WAITOK|M_ZERO); 4709 4710 KASSERT(pmc_pmcdisp != NULL, 4711 ("[pmc,%d] pmcdisp allocation returned NULL", __LINE__)); 4712 4713 /* mark all PMCs as available */ 4714 for (n = 0; n < (int) md->pmd_npmc; n++) 4715 PMC_MARK_ROW_FREE(n); 4716 4717 /* allocate thread hash tables */ 4718 pmc_ownerhash = hashinit(pmc_hashsize, M_PMC, 4719 &pmc_ownerhashmask); 4720 4721 pmc_processhash = hashinit(pmc_hashsize, M_PMC, 4722 &pmc_processhashmask); 4723 mtx_init(&pmc_processhash_mtx, "pmc-process-hash", "pmc-leaf", 4724 MTX_SPIN); 4725 4726 LIST_INIT(&pmc_ss_owners); 4727 pmc_ss_count = 0; 4728 4729 /* allocate a pool of spin mutexes */ 4730 pmc_mtxpool = mtx_pool_create("pmc-leaf", pmc_mtxpool_size, 4731 MTX_SPIN); 4732 4733 PMCDBG(MOD,INI,1, "pmc_ownerhash=%p, mask=0x%lx " 4734 "targethash=%p mask=0x%lx", pmc_ownerhash, pmc_ownerhashmask, 4735 pmc_processhash, pmc_processhashmask); 4736 4737 /* register process {exit,fork,exec} handlers */ 4738 pmc_exit_tag = EVENTHANDLER_REGISTER(process_exit, 4739 pmc_process_exit, NULL, EVENTHANDLER_PRI_ANY); 4740 pmc_fork_tag = EVENTHANDLER_REGISTER(process_fork, 4741 pmc_process_fork, NULL, EVENTHANDLER_PRI_ANY); 4742 4743 /* initialize logging */ 4744 pmclog_initialize(); 4745 4746 /* set hook functions */ 4747 pmc_intr = md->pmd_intr; 4748 pmc_hook = pmc_hook_handler; 4749 4750 if (error == 0) { 4751 printf(PMC_MODULE_NAME ":"); 4752 for (n = 0; n < (int) md->pmd_nclass; n++) { 4753 pcd = &md->pmd_classdep[n]; 4754 printf(" %s/%d/%d/0x%b", 4755 pmc_name_of_pmcclass[pcd->pcd_class], 4756 pcd->pcd_num, 4757 pcd->pcd_width, 4758 pcd->pcd_caps, 4759 "\20" 4760 "\1INT\2USR\3SYS\4EDG\5THR" 4761 "\6REA\7WRI\10INV\11QUA\12PRC" 4762 "\13TAG\14CSC"); 4763 } 4764 printf("\n"); 4765 } 4766 4767 return (error); 4768 } 4769 4770 /* prepare to be unloaded */ 4771 static void 4772 pmc_cleanup(void) 4773 { 4774 int c, cpu; 4775 unsigned int maxcpu; 4776 struct pmc_ownerhash *ph; 4777 struct pmc_owner *po, *tmp; 4778 struct pmc_binding pb; 4779 #ifdef DEBUG 4780 struct pmc_processhash *prh; 4781 #endif 4782 4783 PMCDBG(MOD,INI,0, "%s", "cleanup"); 4784 4785 /* switch off sampling */ 4786 atomic_store_rel_int(&pmc_cpumask, 0); 4787 pmc_intr = NULL; 4788 4789 sx_xlock(&pmc_sx); 4790 if (pmc_hook == NULL) { /* being unloaded already */ 4791 sx_xunlock(&pmc_sx); 4792 return; 4793 } 4794 4795 pmc_hook = NULL; /* prevent new threads from entering module */ 4796 4797 /* deregister event handlers */ 4798 EVENTHANDLER_DEREGISTER(process_fork, pmc_fork_tag); 4799 EVENTHANDLER_DEREGISTER(process_exit, pmc_exit_tag); 4800 4801 /* send SIGBUS to all owner threads, free up allocations */ 4802 if (pmc_ownerhash) 4803 for (ph = pmc_ownerhash; 4804 ph <= &pmc_ownerhash[pmc_ownerhashmask]; 4805 ph++) { 4806 LIST_FOREACH_SAFE(po, ph, po_next, tmp) { 4807 pmc_remove_owner(po); 4808 4809 /* send SIGBUS to owner processes */ 4810 PMCDBG(MOD,INI,2, "cleanup signal proc=%p " 4811 "(%d, %s)", po->po_owner, 4812 po->po_owner->p_pid, 4813 po->po_owner->p_comm); 4814 4815 PROC_LOCK(po->po_owner); 4816 psignal(po->po_owner, SIGBUS); 4817 PROC_UNLOCK(po->po_owner); 4818 4819 pmc_destroy_owner_descriptor(po); 4820 } 4821 } 4822 4823 /* reclaim allocated data structures */ 4824 if (pmc_mtxpool) 4825 mtx_pool_destroy(&pmc_mtxpool); 4826 4827 mtx_destroy(&pmc_processhash_mtx); 4828 if (pmc_processhash) { 4829 #ifdef DEBUG 4830 struct pmc_process *pp; 4831 4832 PMCDBG(MOD,INI,3, "%s", "destroy process hash"); 4833 for (prh = pmc_processhash; 4834 prh <= &pmc_processhash[pmc_processhashmask]; 4835 prh++) 4836 LIST_FOREACH(pp, prh, pp_next) 4837 PMCDBG(MOD,INI,3, "pid=%d", pp->pp_proc->p_pid); 4838 #endif 4839 4840 hashdestroy(pmc_processhash, M_PMC, pmc_processhashmask); 4841 pmc_processhash = NULL; 4842 } 4843 4844 if (pmc_ownerhash) { 4845 PMCDBG(MOD,INI,3, "%s", "destroy owner hash"); 4846 hashdestroy(pmc_ownerhash, M_PMC, pmc_ownerhashmask); 4847 pmc_ownerhash = NULL; 4848 } 4849 4850 KASSERT(LIST_EMPTY(&pmc_ss_owners), 4851 ("[pmc,%d] Global SS owner list not empty", __LINE__)); 4852 KASSERT(pmc_ss_count == 0, 4853 ("[pmc,%d] Global SS count not empty", __LINE__)); 4854 4855 /* do processor and pmc-class dependent cleanup */ 4856 maxcpu = pmc_cpu_max(); 4857 4858 PMCDBG(MOD,INI,3, "%s", "md cleanup"); 4859 if (md) { 4860 pmc_save_cpu_binding(&pb); 4861 for (cpu = 0; cpu < maxcpu; cpu++) { 4862 PMCDBG(MOD,INI,1,"pmc-cleanup cpu=%d pcs=%p", 4863 cpu, pmc_pcpu[cpu]); 4864 if (!pmc_cpu_is_active(cpu) || pmc_pcpu[cpu] == NULL) 4865 continue; 4866 pmc_select_cpu(cpu); 4867 for (c = 0; c < md->pmd_nclass; c++) 4868 md->pmd_classdep[c].pcd_pcpu_fini(md, cpu); 4869 if (md->pmd_pcpu_fini) 4870 md->pmd_pcpu_fini(md, cpu); 4871 } 4872 4873 pmc_md_finalize(md); 4874 4875 free(md, M_PMC); 4876 md = NULL; 4877 pmc_restore_cpu_binding(&pb); 4878 } 4879 4880 /* Free per-cpu descriptors. */ 4881 for (cpu = 0; cpu < maxcpu; cpu++) { 4882 if (!pmc_cpu_is_active(cpu)) 4883 continue; 4884 KASSERT(pmc_pcpu[cpu]->pc_sb != NULL, 4885 ("[pmc,%d] Null cpu sample buffer cpu=%d", __LINE__, 4886 cpu)); 4887 free(pmc_pcpu[cpu]->pc_sb->ps_callchains, M_PMC); 4888 free(pmc_pcpu[cpu]->pc_sb, M_PMC); 4889 free(pmc_pcpu[cpu], M_PMC); 4890 } 4891 4892 free(pmc_pcpu, M_PMC); 4893 pmc_pcpu = NULL; 4894 4895 free(pmc_pcpu_saved, M_PMC); 4896 pmc_pcpu_saved = NULL; 4897 4898 if (pmc_pmcdisp) { 4899 free(pmc_pmcdisp, M_PMC); 4900 pmc_pmcdisp = NULL; 4901 } 4902 4903 if (pmc_rowindex_to_classdep) { 4904 free(pmc_rowindex_to_classdep, M_PMC); 4905 pmc_rowindex_to_classdep = NULL; 4906 } 4907 4908 pmclog_shutdown(); 4909 4910 sx_xunlock(&pmc_sx); /* we are done */ 4911 } 4912 4913 /* 4914 * The function called at load/unload. 4915 */ 4916 4917 static int 4918 load (struct module *module __unused, int cmd, void *arg __unused) 4919 { 4920 int error; 4921 4922 error = 0; 4923 4924 switch (cmd) { 4925 case MOD_LOAD : 4926 /* initialize the subsystem */ 4927 error = pmc_initialize(); 4928 if (error != 0) 4929 break; 4930 PMCDBG(MOD,INI,1, "syscall=%d maxcpu=%d", 4931 pmc_syscall_num, pmc_cpu_max()); 4932 break; 4933 4934 4935 case MOD_UNLOAD : 4936 case MOD_SHUTDOWN: 4937 pmc_cleanup(); 4938 PMCDBG(MOD,INI,1, "%s", "unloaded"); 4939 break; 4940 4941 default : 4942 error = EINVAL; /* XXX should panic(9) */ 4943 break; 4944 } 4945 4946 return error; 4947 } 4948 4949 /* memory pool */ 4950 MALLOC_DEFINE(M_PMC, "pmc", "Memory space for the PMC module"); 4951