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/mutex.h> 45 #include <sys/pmc.h> 46 #include <sys/pmckern.h> 47 #include <sys/pmclog.h> 48 #include <sys/priv.h> 49 #include <sys/proc.h> 50 #include <sys/queue.h> 51 #include <sys/resourcevar.h> 52 #include <sys/sched.h> 53 #include <sys/signalvar.h> 54 #include <sys/smp.h> 55 #include <sys/sx.h> 56 #include <sys/sysctl.h> 57 #include <sys/sysent.h> 58 #include <sys/systm.h> 59 #include <sys/vnode.h> 60 61 #include <sys/linker.h> /* needs to be after <sys/malloc.h> */ 62 63 #include <machine/atomic.h> 64 #include <machine/md_var.h> 65 66 /* 67 * Types 68 */ 69 70 enum pmc_flags { 71 PMC_FLAG_NONE = 0x00, /* do nothing */ 72 PMC_FLAG_REMOVE = 0x01, /* atomically remove entry from hash */ 73 PMC_FLAG_ALLOCATE = 0x02, /* add entry to hash if not found */ 74 }; 75 76 /* 77 * The offset in sysent where the syscall is allocated. 78 */ 79 80 static int pmc_syscall_num = NO_SYSCALL; 81 struct pmc_cpu **pmc_pcpu; /* per-cpu state */ 82 pmc_value_t *pmc_pcpu_saved; /* saved PMC values: CSW handling */ 83 84 #define PMC_PCPU_SAVED(C,R) pmc_pcpu_saved[(R) + md->pmd_npmc*(C)] 85 86 struct mtx_pool *pmc_mtxpool; 87 static int *pmc_pmcdisp; /* PMC row dispositions */ 88 89 #define PMC_ROW_DISP_IS_FREE(R) (pmc_pmcdisp[(R)] == 0) 90 #define PMC_ROW_DISP_IS_THREAD(R) (pmc_pmcdisp[(R)] > 0) 91 #define PMC_ROW_DISP_IS_STANDALONE(R) (pmc_pmcdisp[(R)] < 0) 92 93 #define PMC_MARK_ROW_FREE(R) do { \ 94 pmc_pmcdisp[(R)] = 0; \ 95 } while (0) 96 97 #define PMC_MARK_ROW_STANDALONE(R) do { \ 98 KASSERT(pmc_pmcdisp[(R)] <= 0, ("[pmc,%d] row disposition error", \ 99 __LINE__)); \ 100 atomic_add_int(&pmc_pmcdisp[(R)], -1); \ 101 KASSERT(pmc_pmcdisp[(R)] >= (-pmc_cpu_max_active()), \ 102 ("[pmc,%d] row disposition error", __LINE__)); \ 103 } while (0) 104 105 #define PMC_UNMARK_ROW_STANDALONE(R) do { \ 106 atomic_add_int(&pmc_pmcdisp[(R)], 1); \ 107 KASSERT(pmc_pmcdisp[(R)] <= 0, ("[pmc,%d] row disposition error", \ 108 __LINE__)); \ 109 } while (0) 110 111 #define PMC_MARK_ROW_THREAD(R) do { \ 112 KASSERT(pmc_pmcdisp[(R)] >= 0, ("[pmc,%d] row disposition error", \ 113 __LINE__)); \ 114 atomic_add_int(&pmc_pmcdisp[(R)], 1); \ 115 } while (0) 116 117 #define PMC_UNMARK_ROW_THREAD(R) do { \ 118 atomic_add_int(&pmc_pmcdisp[(R)], -1); \ 119 KASSERT(pmc_pmcdisp[(R)] >= 0, ("[pmc,%d] row disposition error", \ 120 __LINE__)); \ 121 } while (0) 122 123 124 /* various event handlers */ 125 static eventhandler_tag pmc_exit_tag, pmc_fork_tag; 126 127 /* Module statistics */ 128 struct pmc_op_getdriverstats pmc_stats; 129 130 /* Machine/processor dependent operations */ 131 struct pmc_mdep *md; 132 133 /* 134 * Hash tables mapping owner processes and target threads to PMCs. 135 */ 136 137 struct mtx pmc_processhash_mtx; /* spin mutex */ 138 static u_long pmc_processhashmask; 139 static LIST_HEAD(pmc_processhash, pmc_process) *pmc_processhash; 140 141 /* 142 * Hash table of PMC owner descriptors. This table is protected by 143 * the shared PMC "sx" lock. 144 */ 145 146 static u_long pmc_ownerhashmask; 147 static LIST_HEAD(pmc_ownerhash, pmc_owner) *pmc_ownerhash; 148 149 /* 150 * List of PMC owners with system-wide sampling PMCs. 151 */ 152 153 static LIST_HEAD(, pmc_owner) pmc_ss_owners; 154 155 156 /* 157 * Prototypes 158 */ 159 160 #ifdef DEBUG 161 static int pmc_debugflags_sysctl_handler(SYSCTL_HANDLER_ARGS); 162 static int pmc_debugflags_parse(char *newstr, char *fence); 163 #endif 164 165 static int load(struct module *module, int cmd, void *arg); 166 static int pmc_attach_process(struct proc *p, struct pmc *pm); 167 static struct pmc *pmc_allocate_pmc_descriptor(void); 168 static struct pmc_owner *pmc_allocate_owner_descriptor(struct proc *p); 169 static int pmc_attach_one_process(struct proc *p, struct pmc *pm); 170 static int pmc_can_allocate_rowindex(struct proc *p, unsigned int ri, 171 int cpu); 172 static int pmc_can_attach(struct pmc *pm, struct proc *p); 173 static void pmc_capture_user_callchain(int cpu, struct trapframe *tf); 174 static void pmc_cleanup(void); 175 static int pmc_detach_process(struct proc *p, struct pmc *pm); 176 static int pmc_detach_one_process(struct proc *p, struct pmc *pm, 177 int flags); 178 static void pmc_destroy_owner_descriptor(struct pmc_owner *po); 179 static struct pmc_owner *pmc_find_owner_descriptor(struct proc *p); 180 static int pmc_find_pmc(pmc_id_t pmcid, struct pmc **pm); 181 static struct pmc *pmc_find_pmc_descriptor_in_process(struct pmc_owner *po, 182 pmc_id_t pmc); 183 static struct pmc_process *pmc_find_process_descriptor(struct proc *p, 184 uint32_t mode); 185 static void pmc_force_context_switch(void); 186 static void pmc_link_target_process(struct pmc *pm, 187 struct pmc_process *pp); 188 static void pmc_log_all_process_mappings(struct pmc_owner *po); 189 static void pmc_log_kernel_mappings(struct pmc *pm); 190 static void pmc_log_process_mappings(struct pmc_owner *po, struct proc *p); 191 static void pmc_maybe_remove_owner(struct pmc_owner *po); 192 static void pmc_process_csw_in(struct thread *td); 193 static void pmc_process_csw_out(struct thread *td); 194 static void pmc_process_exit(void *arg, struct proc *p); 195 static void pmc_process_fork(void *arg, struct proc *p1, 196 struct proc *p2, int n); 197 static void pmc_process_samples(int cpu); 198 static void pmc_release_pmc_descriptor(struct pmc *pmc); 199 static void pmc_remove_owner(struct pmc_owner *po); 200 static void pmc_remove_process_descriptor(struct pmc_process *pp); 201 static void pmc_restore_cpu_binding(struct pmc_binding *pb); 202 static void pmc_save_cpu_binding(struct pmc_binding *pb); 203 static void pmc_select_cpu(int cpu); 204 static int pmc_start(struct pmc *pm); 205 static int pmc_stop(struct pmc *pm); 206 static int pmc_syscall_handler(struct thread *td, void *syscall_args); 207 static void pmc_unlink_target_process(struct pmc *pmc, 208 struct pmc_process *pp); 209 210 /* 211 * Kernel tunables and sysctl(8) interface. 212 */ 213 214 SYSCTL_NODE(_kern, OID_AUTO, hwpmc, CTLFLAG_RW, 0, "HWPMC parameters"); 215 216 static int pmc_callchaindepth = PMC_CALLCHAIN_DEPTH; 217 TUNABLE_INT(PMC_SYSCTL_NAME_PREFIX "callchaindepth", &pmc_callchaindepth); 218 SYSCTL_INT(_kern_hwpmc, OID_AUTO, callchaindepth, CTLFLAG_TUN|CTLFLAG_RD, 219 &pmc_callchaindepth, 0, "depth of call chain records"); 220 221 #ifdef DEBUG 222 struct pmc_debugflags pmc_debugflags = PMC_DEBUG_DEFAULT_FLAGS; 223 char pmc_debugstr[PMC_DEBUG_STRSIZE]; 224 TUNABLE_STR(PMC_SYSCTL_NAME_PREFIX "debugflags", pmc_debugstr, 225 sizeof(pmc_debugstr)); 226 SYSCTL_PROC(_kern_hwpmc, OID_AUTO, debugflags, 227 CTLTYPE_STRING|CTLFLAG_RW|CTLFLAG_TUN, 228 0, 0, pmc_debugflags_sysctl_handler, "A", "debug flags"); 229 #endif 230 231 /* 232 * kern.hwpmc.hashrows -- determines the number of rows in the 233 * of the hash table used to look up threads 234 */ 235 236 static int pmc_hashsize = PMC_HASH_SIZE; 237 TUNABLE_INT(PMC_SYSCTL_NAME_PREFIX "hashsize", &pmc_hashsize); 238 SYSCTL_INT(_kern_hwpmc, OID_AUTO, hashsize, CTLFLAG_TUN|CTLFLAG_RD, 239 &pmc_hashsize, 0, "rows in hash tables"); 240 241 /* 242 * kern.hwpmc.nsamples --- number of PC samples/callchain stacks per CPU 243 */ 244 245 static int pmc_nsamples = PMC_NSAMPLES; 246 TUNABLE_INT(PMC_SYSCTL_NAME_PREFIX "nsamples", &pmc_nsamples); 247 SYSCTL_INT(_kern_hwpmc, OID_AUTO, nsamples, CTLFLAG_TUN|CTLFLAG_RD, 248 &pmc_nsamples, 0, "number of PC samples per CPU"); 249 250 251 /* 252 * kern.hwpmc.mtxpoolsize -- number of mutexes in the mutex pool. 253 */ 254 255 static int pmc_mtxpool_size = PMC_MTXPOOL_SIZE; 256 TUNABLE_INT(PMC_SYSCTL_NAME_PREFIX "mtxpoolsize", &pmc_mtxpool_size); 257 SYSCTL_INT(_kern_hwpmc, OID_AUTO, mtxpoolsize, CTLFLAG_TUN|CTLFLAG_RD, 258 &pmc_mtxpool_size, 0, "size of spin mutex pool"); 259 260 261 /* 262 * security.bsd.unprivileged_syspmcs -- allow non-root processes to 263 * allocate system-wide PMCs. 264 * 265 * Allowing unprivileged processes to allocate system PMCs is convenient 266 * if system-wide measurements need to be taken concurrently with other 267 * per-process measurements. This feature is turned off by default. 268 */ 269 270 static int pmc_unprivileged_syspmcs = 0; 271 TUNABLE_INT("security.bsd.unprivileged_syspmcs", &pmc_unprivileged_syspmcs); 272 SYSCTL_INT(_security_bsd, OID_AUTO, unprivileged_syspmcs, CTLFLAG_RW, 273 &pmc_unprivileged_syspmcs, 0, 274 "allow unprivileged process to allocate system PMCs"); 275 276 /* 277 * Hash function. Discard the lower 2 bits of the pointer since 278 * these are always zero for our uses. The hash multiplier is 279 * round((2^LONG_BIT) * ((sqrt(5)-1)/2)). 280 */ 281 282 #if LONG_BIT == 64 283 #define _PMC_HM 11400714819323198486u 284 #elif LONG_BIT == 32 285 #define _PMC_HM 2654435769u 286 #else 287 #error Must know the size of 'long' to compile 288 #endif 289 290 #define PMC_HASH_PTR(P,M) ((((unsigned long) (P) >> 2) * _PMC_HM) & (M)) 291 292 /* 293 * Syscall structures 294 */ 295 296 /* The `sysent' for the new syscall */ 297 static struct sysent pmc_sysent = { 298 2, /* sy_narg */ 299 pmc_syscall_handler /* sy_call */ 300 }; 301 302 static struct syscall_module_data pmc_syscall_mod = { 303 load, 304 NULL, 305 &pmc_syscall_num, 306 &pmc_sysent, 307 { 0, NULL } 308 }; 309 310 static moduledata_t pmc_mod = { 311 PMC_MODULE_NAME, 312 syscall_module_handler, 313 &pmc_syscall_mod 314 }; 315 316 DECLARE_MODULE(pmc, pmc_mod, SI_SUB_SMP, SI_ORDER_ANY); 317 MODULE_VERSION(pmc, PMC_VERSION); 318 319 #ifdef DEBUG 320 enum pmc_dbgparse_state { 321 PMCDS_WS, /* in whitespace */ 322 PMCDS_MAJOR, /* seen a major keyword */ 323 PMCDS_MINOR 324 }; 325 326 static int 327 pmc_debugflags_parse(char *newstr, char *fence) 328 { 329 char c, *p, *q; 330 struct pmc_debugflags *tmpflags; 331 int error, found, *newbits, tmp; 332 size_t kwlen; 333 334 tmpflags = malloc(sizeof(*tmpflags), M_PMC, M_WAITOK|M_ZERO); 335 336 p = newstr; 337 error = 0; 338 339 for (; p < fence && (c = *p); p++) { 340 341 /* skip white space */ 342 if (c == ' ' || c == '\t') 343 continue; 344 345 /* look for a keyword followed by "=" */ 346 for (q = p; p < fence && (c = *p) && c != '='; p++) 347 ; 348 if (c != '=') { 349 error = EINVAL; 350 goto done; 351 } 352 353 kwlen = p - q; 354 newbits = NULL; 355 356 /* lookup flag group name */ 357 #define DBG_SET_FLAG_MAJ(S,F) \ 358 if (kwlen == sizeof(S)-1 && strncmp(q, S, kwlen) == 0) \ 359 newbits = &tmpflags->pdb_ ## F; 360 361 DBG_SET_FLAG_MAJ("cpu", CPU); 362 DBG_SET_FLAG_MAJ("csw", CSW); 363 DBG_SET_FLAG_MAJ("logging", LOG); 364 DBG_SET_FLAG_MAJ("module", MOD); 365 DBG_SET_FLAG_MAJ("md", MDP); 366 DBG_SET_FLAG_MAJ("owner", OWN); 367 DBG_SET_FLAG_MAJ("pmc", PMC); 368 DBG_SET_FLAG_MAJ("process", PRC); 369 DBG_SET_FLAG_MAJ("sampling", SAM); 370 371 if (newbits == NULL) { 372 error = EINVAL; 373 goto done; 374 } 375 376 p++; /* skip the '=' */ 377 378 /* Now parse the individual flags */ 379 tmp = 0; 380 newflag: 381 for (q = p; p < fence && (c = *p); p++) 382 if (c == ' ' || c == '\t' || c == ',') 383 break; 384 385 /* p == fence or c == ws or c == "," or c == 0 */ 386 387 if ((kwlen = p - q) == 0) { 388 *newbits = tmp; 389 continue; 390 } 391 392 found = 0; 393 #define DBG_SET_FLAG_MIN(S,F) \ 394 if (kwlen == sizeof(S)-1 && strncmp(q, S, kwlen) == 0) \ 395 tmp |= found = (1 << PMC_DEBUG_MIN_ ## F) 396 397 /* a '*' denotes all possible flags in the group */ 398 if (kwlen == 1 && *q == '*') 399 tmp = found = ~0; 400 /* look for individual flag names */ 401 DBG_SET_FLAG_MIN("allocaterow", ALR); 402 DBG_SET_FLAG_MIN("allocate", ALL); 403 DBG_SET_FLAG_MIN("attach", ATT); 404 DBG_SET_FLAG_MIN("bind", BND); 405 DBG_SET_FLAG_MIN("config", CFG); 406 DBG_SET_FLAG_MIN("exec", EXC); 407 DBG_SET_FLAG_MIN("exit", EXT); 408 DBG_SET_FLAG_MIN("find", FND); 409 DBG_SET_FLAG_MIN("flush", FLS); 410 DBG_SET_FLAG_MIN("fork", FRK); 411 DBG_SET_FLAG_MIN("getbuf", GTB); 412 DBG_SET_FLAG_MIN("hook", PMH); 413 DBG_SET_FLAG_MIN("init", INI); 414 DBG_SET_FLAG_MIN("intr", INT); 415 DBG_SET_FLAG_MIN("linktarget", TLK); 416 DBG_SET_FLAG_MIN("mayberemove", OMR); 417 DBG_SET_FLAG_MIN("ops", OPS); 418 DBG_SET_FLAG_MIN("read", REA); 419 DBG_SET_FLAG_MIN("register", REG); 420 DBG_SET_FLAG_MIN("release", REL); 421 DBG_SET_FLAG_MIN("remove", ORM); 422 DBG_SET_FLAG_MIN("sample", SAM); 423 DBG_SET_FLAG_MIN("scheduleio", SIO); 424 DBG_SET_FLAG_MIN("select", SEL); 425 DBG_SET_FLAG_MIN("signal", SIG); 426 DBG_SET_FLAG_MIN("swi", SWI); 427 DBG_SET_FLAG_MIN("swo", SWO); 428 DBG_SET_FLAG_MIN("start", STA); 429 DBG_SET_FLAG_MIN("stop", STO); 430 DBG_SET_FLAG_MIN("syscall", PMS); 431 DBG_SET_FLAG_MIN("unlinktarget", TUL); 432 DBG_SET_FLAG_MIN("write", WRI); 433 if (found == 0) { 434 /* unrecognized flag name */ 435 error = EINVAL; 436 goto done; 437 } 438 439 if (c == 0 || c == ' ' || c == '\t') { /* end of flag group */ 440 *newbits = tmp; 441 continue; 442 } 443 444 p++; 445 goto newflag; 446 } 447 448 /* save the new flag set */ 449 bcopy(tmpflags, &pmc_debugflags, sizeof(pmc_debugflags)); 450 451 done: 452 free(tmpflags, M_PMC); 453 return error; 454 } 455 456 static int 457 pmc_debugflags_sysctl_handler(SYSCTL_HANDLER_ARGS) 458 { 459 char *fence, *newstr; 460 int error; 461 unsigned int n; 462 463 (void) arg1; (void) arg2; /* unused parameters */ 464 465 n = sizeof(pmc_debugstr); 466 newstr = malloc(n, M_PMC, M_ZERO|M_WAITOK); 467 (void) strlcpy(newstr, pmc_debugstr, n); 468 469 error = sysctl_handle_string(oidp, newstr, n, req); 470 471 /* if there is a new string, parse and copy it */ 472 if (error == 0 && req->newptr != NULL) { 473 fence = newstr + (n < req->newlen ? n : req->newlen + 1); 474 if ((error = pmc_debugflags_parse(newstr, fence)) == 0) 475 (void) strlcpy(pmc_debugstr, newstr, 476 sizeof(pmc_debugstr)); 477 } 478 479 free(newstr, M_PMC); 480 481 return error; 482 } 483 #endif 484 485 /* 486 * Concurrency Control 487 * 488 * The driver manages the following data structures: 489 * 490 * - target process descriptors, one per target process 491 * - owner process descriptors (and attached lists), one per owner process 492 * - lookup hash tables for owner and target processes 493 * - PMC descriptors (and attached lists) 494 * - per-cpu hardware state 495 * - the 'hook' variable through which the kernel calls into 496 * this module 497 * - the machine hardware state (managed by the MD layer) 498 * 499 * These data structures are accessed from: 500 * 501 * - thread context-switch code 502 * - interrupt handlers (possibly on multiple cpus) 503 * - kernel threads on multiple cpus running on behalf of user 504 * processes doing system calls 505 * - this driver's private kernel threads 506 * 507 * = Locks and Locking strategy = 508 * 509 * The driver uses four locking strategies for its operation: 510 * 511 * - The global SX lock "pmc_sx" is used to protect internal 512 * data structures. 513 * 514 * Calls into the module by syscall() start with this lock being 515 * held in exclusive mode. Depending on the requested operation, 516 * the lock may be downgraded to 'shared' mode to allow more 517 * concurrent readers into the module. Calls into the module from 518 * other parts of the kernel acquire the lock in shared mode. 519 * 520 * This SX lock is held in exclusive mode for any operations that 521 * modify the linkages between the driver's internal data structures. 522 * 523 * The 'pmc_hook' function pointer is also protected by this lock. 524 * It is only examined with the sx lock held in exclusive mode. The 525 * kernel module is allowed to be unloaded only with the sx lock held 526 * in exclusive mode. In normal syscall handling, after acquiring the 527 * pmc_sx lock we first check that 'pmc_hook' is non-null before 528 * proceeding. This prevents races between the thread unloading the module 529 * and other threads seeking to use the module. 530 * 531 * - Lookups of target process structures and owner process structures 532 * cannot use the global "pmc_sx" SX lock because these lookups need 533 * to happen during context switches and in other critical sections 534 * where sleeping is not allowed. We protect these lookup tables 535 * with their own private spin-mutexes, "pmc_processhash_mtx" and 536 * "pmc_ownerhash_mtx". 537 * 538 * - Interrupt handlers work in a lock free manner. At interrupt 539 * time, handlers look at the PMC pointer (phw->phw_pmc) configured 540 * when the PMC was started. If this pointer is NULL, the interrupt 541 * is ignored after updating driver statistics. We ensure that this 542 * pointer is set (using an atomic operation if necessary) before the 543 * PMC hardware is started. Conversely, this pointer is unset atomically 544 * only after the PMC hardware is stopped. 545 * 546 * We ensure that everything needed for the operation of an 547 * interrupt handler is available without it needing to acquire any 548 * locks. We also ensure that a PMC's software state is destroyed only 549 * after the PMC is taken off hardware (on all CPUs). 550 * 551 * - Context-switch handling with process-private PMCs needs more 552 * care. 553 * 554 * A given process may be the target of multiple PMCs. For example, 555 * PMCATTACH and PMCDETACH may be requested by a process on one CPU 556 * while the target process is running on another. A PMC could also 557 * be getting released because its owner is exiting. We tackle 558 * these situations in the following manner: 559 * 560 * - each target process structure 'pmc_process' has an array 561 * of 'struct pmc *' pointers, one for each hardware PMC. 562 * 563 * - At context switch IN time, each "target" PMC in RUNNING state 564 * gets started on hardware and a pointer to each PMC is copied into 565 * the per-cpu phw array. The 'runcount' for the PMC is 566 * incremented. 567 * 568 * - At context switch OUT time, all process-virtual PMCs are stopped 569 * on hardware. The saved value is added to the PMCs value field 570 * only if the PMC is in a non-deleted state (the PMCs state could 571 * have changed during the current time slice). 572 * 573 * Note that since in-between a switch IN on a processor and a switch 574 * OUT, the PMC could have been released on another CPU. Therefore 575 * context switch OUT always looks at the hardware state to turn 576 * OFF PMCs and will update a PMC's saved value only if reachable 577 * from the target process record. 578 * 579 * - OP PMCRELEASE could be called on a PMC at any time (the PMC could 580 * be attached to many processes at the time of the call and could 581 * be active on multiple CPUs). 582 * 583 * We prevent further scheduling of the PMC by marking it as in 584 * state 'DELETED'. If the runcount of the PMC is non-zero then 585 * this PMC is currently running on a CPU somewhere. The thread 586 * doing the PMCRELEASE operation waits by repeatedly doing a 587 * pause() till the runcount comes to zero. 588 * 589 * The contents of a PMC descriptor (struct pmc) are protected using 590 * a spin-mutex. In order to save space, we use a mutex pool. 591 * 592 * In terms of lock types used by witness(4), we use: 593 * - Type "pmc-sx", used by the global SX lock. 594 * - Type "pmc-sleep", for sleep mutexes used by logger threads. 595 * - Type "pmc-per-proc", for protecting PMC owner descriptors. 596 * - Type "pmc-leaf", used for all other spin mutexes. 597 */ 598 599 /* 600 * save the cpu binding of the current kthread 601 */ 602 603 static void 604 pmc_save_cpu_binding(struct pmc_binding *pb) 605 { 606 PMCDBG(CPU,BND,2, "%s", "save-cpu"); 607 thread_lock(curthread); 608 pb->pb_bound = sched_is_bound(curthread); 609 pb->pb_cpu = curthread->td_oncpu; 610 thread_unlock(curthread); 611 PMCDBG(CPU,BND,2, "save-cpu cpu=%d", pb->pb_cpu); 612 } 613 614 /* 615 * restore the cpu binding of the current thread 616 */ 617 618 static void 619 pmc_restore_cpu_binding(struct pmc_binding *pb) 620 { 621 PMCDBG(CPU,BND,2, "restore-cpu curcpu=%d restore=%d", 622 curthread->td_oncpu, pb->pb_cpu); 623 thread_lock(curthread); 624 if (pb->pb_bound) 625 sched_bind(curthread, pb->pb_cpu); 626 else 627 sched_unbind(curthread); 628 thread_unlock(curthread); 629 PMCDBG(CPU,BND,2, "%s", "restore-cpu done"); 630 } 631 632 /* 633 * move execution over the specified cpu and bind it there. 634 */ 635 636 static void 637 pmc_select_cpu(int cpu) 638 { 639 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 640 ("[pmc,%d] bad cpu number %d", __LINE__, cpu)); 641 642 /* Never move to an inactive CPU. */ 643 KASSERT(pmc_cpu_is_active(cpu), ("[pmc,%d] selecting inactive " 644 "CPU %d", __LINE__, cpu)); 645 646 PMCDBG(CPU,SEL,2, "select-cpu cpu=%d", cpu); 647 thread_lock(curthread); 648 sched_bind(curthread, cpu); 649 thread_unlock(curthread); 650 651 KASSERT(curthread->td_oncpu == cpu, 652 ("[pmc,%d] CPU not bound [cpu=%d, curr=%d]", __LINE__, 653 cpu, curthread->td_oncpu)); 654 655 PMCDBG(CPU,SEL,2, "select-cpu cpu=%d ok", cpu); 656 } 657 658 /* 659 * Force a context switch. 660 * 661 * We do this by pause'ing for 1 tick -- invoking mi_switch() is not 662 * guaranteed to force a context switch. 663 */ 664 665 static void 666 pmc_force_context_switch(void) 667 { 668 669 pause("pmcctx", 1); 670 } 671 672 /* 673 * Get the file name for an executable. This is a simple wrapper 674 * around vn_fullpath(9). 675 */ 676 677 static void 678 pmc_getfilename(struct vnode *v, char **fullpath, char **freepath) 679 { 680 681 *fullpath = "unknown"; 682 *freepath = NULL; 683 vn_fullpath(curthread, v, fullpath, freepath); 684 } 685 686 /* 687 * remove an process owning PMCs 688 */ 689 690 void 691 pmc_remove_owner(struct pmc_owner *po) 692 { 693 struct pmc *pm, *tmp; 694 695 sx_assert(&pmc_sx, SX_XLOCKED); 696 697 PMCDBG(OWN,ORM,1, "remove-owner po=%p", po); 698 699 /* Remove descriptor from the owner hash table */ 700 LIST_REMOVE(po, po_next); 701 702 /* release all owned PMC descriptors */ 703 LIST_FOREACH_SAFE(pm, &po->po_pmcs, pm_next, tmp) { 704 PMCDBG(OWN,ORM,2, "pmc=%p", pm); 705 KASSERT(pm->pm_owner == po, 706 ("[pmc,%d] owner %p != po %p", __LINE__, pm->pm_owner, po)); 707 708 pmc_release_pmc_descriptor(pm); /* will unlink from the list */ 709 } 710 711 KASSERT(po->po_sscount == 0, 712 ("[pmc,%d] SS count not zero", __LINE__)); 713 KASSERT(LIST_EMPTY(&po->po_pmcs), 714 ("[pmc,%d] PMC list not empty", __LINE__)); 715 716 /* de-configure the log file if present */ 717 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 718 pmclog_deconfigure_log(po); 719 } 720 721 /* 722 * remove an owner process record if all conditions are met. 723 */ 724 725 static void 726 pmc_maybe_remove_owner(struct pmc_owner *po) 727 { 728 729 PMCDBG(OWN,OMR,1, "maybe-remove-owner po=%p", po); 730 731 /* 732 * Remove owner record if 733 * - this process does not own any PMCs 734 * - this process has not allocated a system-wide sampling buffer 735 */ 736 737 if (LIST_EMPTY(&po->po_pmcs) && 738 ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0)) { 739 pmc_remove_owner(po); 740 pmc_destroy_owner_descriptor(po); 741 } 742 } 743 744 /* 745 * Add an association between a target process and a PMC. 746 */ 747 748 static void 749 pmc_link_target_process(struct pmc *pm, struct pmc_process *pp) 750 { 751 int ri; 752 struct pmc_target *pt; 753 754 sx_assert(&pmc_sx, SX_XLOCKED); 755 756 KASSERT(pm != NULL && pp != NULL, 757 ("[pmc,%d] Null pm %p or pp %p", __LINE__, pm, pp)); 758 KASSERT(PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)), 759 ("[pmc,%d] Attaching a non-process-virtual pmc=%p to pid=%d", 760 __LINE__, pm, pp->pp_proc->p_pid)); 761 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt < ((int) md->pmd_npmc - 1), 762 ("[pmc,%d] Illegal reference count %d for process record %p", 763 __LINE__, pp->pp_refcnt, (void *) pp)); 764 765 ri = PMC_TO_ROWINDEX(pm); 766 767 PMCDBG(PRC,TLK,1, "link-target pmc=%p ri=%d pmc-process=%p", 768 pm, ri, pp); 769 770 #ifdef DEBUG 771 LIST_FOREACH(pt, &pm->pm_targets, pt_next) 772 if (pt->pt_process == pp) 773 KASSERT(0, ("[pmc,%d] pp %p already in pmc %p targets", 774 __LINE__, pp, pm)); 775 #endif 776 777 pt = malloc(sizeof(struct pmc_target), M_PMC, M_ZERO|M_WAITOK); 778 779 pt->pt_process = pp; 780 781 LIST_INSERT_HEAD(&pm->pm_targets, pt, pt_next); 782 783 atomic_store_rel_ptr((uintptr_t *)&pp->pp_pmcs[ri].pp_pmc, 784 (uintptr_t)pm); 785 786 if (pm->pm_owner->po_owner == pp->pp_proc) 787 pm->pm_flags |= PMC_F_ATTACHED_TO_OWNER; 788 789 /* 790 * Initialize the per-process values at this row index. 791 */ 792 pp->pp_pmcs[ri].pp_pmcval = PMC_TO_MODE(pm) == PMC_MODE_TS ? 793 pm->pm_sc.pm_reloadcount : 0; 794 795 pp->pp_refcnt++; 796 797 } 798 799 /* 800 * Removes the association between a target process and a PMC. 801 */ 802 803 static void 804 pmc_unlink_target_process(struct pmc *pm, struct pmc_process *pp) 805 { 806 int ri; 807 struct proc *p; 808 struct pmc_target *ptgt; 809 810 sx_assert(&pmc_sx, SX_XLOCKED); 811 812 KASSERT(pm != NULL && pp != NULL, 813 ("[pmc,%d] Null pm %p or pp %p", __LINE__, pm, pp)); 814 815 KASSERT(pp->pp_refcnt >= 1 && pp->pp_refcnt < (int) md->pmd_npmc, 816 ("[pmc,%d] Illegal ref count %d on process record %p", 817 __LINE__, pp->pp_refcnt, (void *) pp)); 818 819 ri = PMC_TO_ROWINDEX(pm); 820 821 PMCDBG(PRC,TUL,1, "unlink-target pmc=%p ri=%d pmc-process=%p", 822 pm, ri, pp); 823 824 KASSERT(pp->pp_pmcs[ri].pp_pmc == pm, 825 ("[pmc,%d] PMC ri %d mismatch pmc %p pp->[ri] %p", __LINE__, 826 ri, pm, pp->pp_pmcs[ri].pp_pmc)); 827 828 pp->pp_pmcs[ri].pp_pmc = NULL; 829 pp->pp_pmcs[ri].pp_pmcval = (pmc_value_t) 0; 830 831 /* Remove owner-specific flags */ 832 if (pm->pm_owner->po_owner == pp->pp_proc) { 833 pp->pp_flags &= ~PMC_PP_ENABLE_MSR_ACCESS; 834 pm->pm_flags &= ~PMC_F_ATTACHED_TO_OWNER; 835 } 836 837 pp->pp_refcnt--; 838 839 /* Remove the target process from the PMC structure */ 840 LIST_FOREACH(ptgt, &pm->pm_targets, pt_next) 841 if (ptgt->pt_process == pp) 842 break; 843 844 KASSERT(ptgt != NULL, ("[pmc,%d] process %p (pp: %p) not found " 845 "in pmc %p", __LINE__, pp->pp_proc, pp, pm)); 846 847 LIST_REMOVE(ptgt, pt_next); 848 free(ptgt, M_PMC); 849 850 /* if the PMC now lacks targets, send the owner a SIGIO */ 851 if (LIST_EMPTY(&pm->pm_targets)) { 852 p = pm->pm_owner->po_owner; 853 PROC_LOCK(p); 854 psignal(p, SIGIO); 855 PROC_UNLOCK(p); 856 857 PMCDBG(PRC,SIG,2, "signalling proc=%p signal=%d", p, 858 SIGIO); 859 } 860 } 861 862 /* 863 * Check if PMC 'pm' may be attached to target process 't'. 864 */ 865 866 static int 867 pmc_can_attach(struct pmc *pm, struct proc *t) 868 { 869 struct proc *o; /* pmc owner */ 870 struct ucred *oc, *tc; /* owner, target credentials */ 871 int decline_attach, i; 872 873 /* 874 * A PMC's owner can always attach that PMC to itself. 875 */ 876 877 if ((o = pm->pm_owner->po_owner) == t) 878 return 0; 879 880 PROC_LOCK(o); 881 oc = o->p_ucred; 882 crhold(oc); 883 PROC_UNLOCK(o); 884 885 PROC_LOCK(t); 886 tc = t->p_ucred; 887 crhold(tc); 888 PROC_UNLOCK(t); 889 890 /* 891 * The effective uid of the PMC owner should match at least one 892 * of the {effective,real,saved} uids of the target process. 893 */ 894 895 decline_attach = oc->cr_uid != tc->cr_uid && 896 oc->cr_uid != tc->cr_svuid && 897 oc->cr_uid != tc->cr_ruid; 898 899 /* 900 * Every one of the target's group ids, must be in the owner's 901 * group list. 902 */ 903 for (i = 0; !decline_attach && i < tc->cr_ngroups; i++) 904 decline_attach = !groupmember(tc->cr_groups[i], oc); 905 906 /* check the read and saved gids too */ 907 if (decline_attach == 0) 908 decline_attach = !groupmember(tc->cr_rgid, oc) || 909 !groupmember(tc->cr_svgid, oc); 910 911 crfree(tc); 912 crfree(oc); 913 914 return !decline_attach; 915 } 916 917 /* 918 * Attach a process to a PMC. 919 */ 920 921 static int 922 pmc_attach_one_process(struct proc *p, struct pmc *pm) 923 { 924 int ri; 925 char *fullpath, *freepath; 926 struct pmc_process *pp; 927 928 sx_assert(&pmc_sx, SX_XLOCKED); 929 930 PMCDBG(PRC,ATT,2, "attach-one pm=%p ri=%d proc=%p (%d, %s)", pm, 931 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 932 933 /* 934 * Locate the process descriptor corresponding to process 'p', 935 * allocating space as needed. 936 * 937 * Verify that rowindex 'pm_rowindex' is free in the process 938 * descriptor. 939 * 940 * If not, allocate space for a descriptor and link the 941 * process descriptor and PMC. 942 */ 943 ri = PMC_TO_ROWINDEX(pm); 944 945 if ((pp = pmc_find_process_descriptor(p, PMC_FLAG_ALLOCATE)) == NULL) 946 return ENOMEM; 947 948 if (pp->pp_pmcs[ri].pp_pmc == pm) /* already present at slot [ri] */ 949 return EEXIST; 950 951 if (pp->pp_pmcs[ri].pp_pmc != NULL) 952 return EBUSY; 953 954 pmc_link_target_process(pm, pp); 955 956 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)) && 957 (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) == 0) 958 pm->pm_flags |= PMC_F_NEEDS_LOGFILE; 959 960 pm->pm_flags |= PMC_F_ATTACH_DONE; /* mark as attached */ 961 962 /* issue an attach event to a configured log file */ 963 if (pm->pm_owner->po_flags & PMC_PO_OWNS_LOGFILE) { 964 pmc_getfilename(p->p_textvp, &fullpath, &freepath); 965 if (p->p_flag & P_KTHREAD) { 966 fullpath = kernelname; 967 freepath = NULL; 968 } else 969 pmclog_process_pmcattach(pm, p->p_pid, fullpath); 970 if (freepath) 971 free(freepath, M_TEMP); 972 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 973 pmc_log_process_mappings(pm->pm_owner, p); 974 } 975 /* mark process as using HWPMCs */ 976 PROC_LOCK(p); 977 p->p_flag |= P_HWPMC; 978 PROC_UNLOCK(p); 979 980 return 0; 981 } 982 983 /* 984 * Attach a process and optionally its children 985 */ 986 987 static int 988 pmc_attach_process(struct proc *p, struct pmc *pm) 989 { 990 int error; 991 struct proc *top; 992 993 sx_assert(&pmc_sx, SX_XLOCKED); 994 995 PMCDBG(PRC,ATT,1, "attach pm=%p ri=%d proc=%p (%d, %s)", pm, 996 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 997 998 999 /* 1000 * If this PMC successfully allowed a GETMSR operation 1001 * in the past, disallow further ATTACHes. 1002 */ 1003 1004 if ((pm->pm_flags & PMC_PP_ENABLE_MSR_ACCESS) != 0) 1005 return EPERM; 1006 1007 if ((pm->pm_flags & PMC_F_DESCENDANTS) == 0) 1008 return pmc_attach_one_process(p, pm); 1009 1010 /* 1011 * Traverse all child processes, attaching them to 1012 * this PMC. 1013 */ 1014 1015 sx_slock(&proctree_lock); 1016 1017 top = p; 1018 1019 for (;;) { 1020 if ((error = pmc_attach_one_process(p, pm)) != 0) 1021 break; 1022 if (!LIST_EMPTY(&p->p_children)) 1023 p = LIST_FIRST(&p->p_children); 1024 else for (;;) { 1025 if (p == top) 1026 goto done; 1027 if (LIST_NEXT(p, p_sibling)) { 1028 p = LIST_NEXT(p, p_sibling); 1029 break; 1030 } 1031 p = p->p_pptr; 1032 } 1033 } 1034 1035 if (error) 1036 (void) pmc_detach_process(top, pm); 1037 1038 done: 1039 sx_sunlock(&proctree_lock); 1040 return error; 1041 } 1042 1043 /* 1044 * Detach a process from a PMC. If there are no other PMCs tracking 1045 * this process, remove the process structure from its hash table. If 1046 * 'flags' contains PMC_FLAG_REMOVE, then free the process structure. 1047 */ 1048 1049 static int 1050 pmc_detach_one_process(struct proc *p, struct pmc *pm, int flags) 1051 { 1052 int ri; 1053 struct pmc_process *pp; 1054 1055 sx_assert(&pmc_sx, SX_XLOCKED); 1056 1057 KASSERT(pm != NULL, 1058 ("[pmc,%d] null pm pointer", __LINE__)); 1059 1060 ri = PMC_TO_ROWINDEX(pm); 1061 1062 PMCDBG(PRC,ATT,2, "detach-one pm=%p ri=%d proc=%p (%d, %s) flags=0x%x", 1063 pm, ri, p, p->p_pid, p->p_comm, flags); 1064 1065 if ((pp = pmc_find_process_descriptor(p, 0)) == NULL) 1066 return ESRCH; 1067 1068 if (pp->pp_pmcs[ri].pp_pmc != pm) 1069 return EINVAL; 1070 1071 pmc_unlink_target_process(pm, pp); 1072 1073 /* Issue a detach entry if a log file is configured */ 1074 if (pm->pm_owner->po_flags & PMC_PO_OWNS_LOGFILE) 1075 pmclog_process_pmcdetach(pm, p->p_pid); 1076 1077 /* 1078 * If there are no PMCs targetting this process, we remove its 1079 * descriptor from the target hash table and unset the P_HWPMC 1080 * flag in the struct proc. 1081 */ 1082 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt < (int) md->pmd_npmc, 1083 ("[pmc,%d] Illegal refcnt %d for process struct %p", 1084 __LINE__, pp->pp_refcnt, pp)); 1085 1086 if (pp->pp_refcnt != 0) /* still a target of some PMC */ 1087 return 0; 1088 1089 pmc_remove_process_descriptor(pp); 1090 1091 if (flags & PMC_FLAG_REMOVE) 1092 free(pp, M_PMC); 1093 1094 PROC_LOCK(p); 1095 p->p_flag &= ~P_HWPMC; 1096 PROC_UNLOCK(p); 1097 1098 return 0; 1099 } 1100 1101 /* 1102 * Detach a process and optionally its descendants from a PMC. 1103 */ 1104 1105 static int 1106 pmc_detach_process(struct proc *p, struct pmc *pm) 1107 { 1108 struct proc *top; 1109 1110 sx_assert(&pmc_sx, SX_XLOCKED); 1111 1112 PMCDBG(PRC,ATT,1, "detach pm=%p ri=%d proc=%p (%d, %s)", pm, 1113 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 1114 1115 if ((pm->pm_flags & PMC_F_DESCENDANTS) == 0) 1116 return pmc_detach_one_process(p, pm, PMC_FLAG_REMOVE); 1117 1118 /* 1119 * Traverse all children, detaching them from this PMC. We 1120 * ignore errors since we could be detaching a PMC from a 1121 * partially attached proc tree. 1122 */ 1123 1124 sx_slock(&proctree_lock); 1125 1126 top = p; 1127 1128 for (;;) { 1129 (void) pmc_detach_one_process(p, pm, PMC_FLAG_REMOVE); 1130 1131 if (!LIST_EMPTY(&p->p_children)) 1132 p = LIST_FIRST(&p->p_children); 1133 else for (;;) { 1134 if (p == top) 1135 goto done; 1136 if (LIST_NEXT(p, p_sibling)) { 1137 p = LIST_NEXT(p, p_sibling); 1138 break; 1139 } 1140 p = p->p_pptr; 1141 } 1142 } 1143 1144 done: 1145 sx_sunlock(&proctree_lock); 1146 1147 if (LIST_EMPTY(&pm->pm_targets)) 1148 pm->pm_flags &= ~PMC_F_ATTACH_DONE; 1149 1150 return 0; 1151 } 1152 1153 1154 /* 1155 * Thread context switch IN 1156 */ 1157 1158 static void 1159 pmc_process_csw_in(struct thread *td) 1160 { 1161 int cpu; 1162 unsigned int ri; 1163 struct pmc *pm; 1164 struct proc *p; 1165 struct pmc_cpu *pc; 1166 struct pmc_hw *phw; 1167 struct pmc_process *pp; 1168 pmc_value_t newvalue; 1169 1170 p = td->td_proc; 1171 1172 if ((pp = pmc_find_process_descriptor(p, PMC_FLAG_NONE)) == NULL) 1173 return; 1174 1175 KASSERT(pp->pp_proc == td->td_proc, 1176 ("[pmc,%d] not my thread state", __LINE__)); 1177 1178 critical_enter(); /* no preemption from this point */ 1179 1180 cpu = PCPU_GET(cpuid); /* td->td_oncpu is invalid */ 1181 1182 PMCDBG(CSW,SWI,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p, 1183 p->p_pid, p->p_comm, pp); 1184 1185 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 1186 ("[pmc,%d] wierd CPU id %d", __LINE__, cpu)); 1187 1188 pc = pmc_pcpu[cpu]; 1189 1190 for (ri = 0; ri < md->pmd_npmc; ri++) { 1191 1192 if ((pm = pp->pp_pmcs[ri].pp_pmc) == NULL) 1193 continue; 1194 1195 KASSERT(PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)), 1196 ("[pmc,%d] Target PMC in non-virtual mode (%d)", 1197 __LINE__, PMC_TO_MODE(pm))); 1198 1199 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 1200 ("[pmc,%d] Row index mismatch pmc %d != ri %d", 1201 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 1202 1203 /* 1204 * Only PMCs that are marked as 'RUNNING' need 1205 * be placed on hardware. 1206 */ 1207 1208 if (pm->pm_state != PMC_STATE_RUNNING) 1209 continue; 1210 1211 /* increment PMC runcount */ 1212 atomic_add_rel_32(&pm->pm_runcount, 1); 1213 1214 /* configure the HWPMC we are going to use. */ 1215 md->pmd_config_pmc(cpu, ri, pm); 1216 1217 phw = pc->pc_hwpmcs[ri]; 1218 1219 KASSERT(phw != NULL, 1220 ("[pmc,%d] null hw pointer", __LINE__)); 1221 1222 KASSERT(phw->phw_pmc == pm, 1223 ("[pmc,%d] hw->pmc %p != pmc %p", __LINE__, 1224 phw->phw_pmc, pm)); 1225 1226 /* 1227 * Write out saved value and start the PMC. 1228 * 1229 * Sampling PMCs use a per-process value, while 1230 * counting mode PMCs use a per-pmc value that is 1231 * inherited across descendants. 1232 */ 1233 if (PMC_TO_MODE(pm) == PMC_MODE_TS) { 1234 mtx_pool_lock_spin(pmc_mtxpool, pm); 1235 newvalue = PMC_PCPU_SAVED(cpu,ri) = 1236 pp->pp_pmcs[ri].pp_pmcval; 1237 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1238 } else { 1239 KASSERT(PMC_TO_MODE(pm) == PMC_MODE_TC, 1240 ("[pmc,%d] illegal mode=%d", __LINE__, 1241 PMC_TO_MODE(pm))); 1242 mtx_pool_lock_spin(pmc_mtxpool, pm); 1243 newvalue = PMC_PCPU_SAVED(cpu, ri) = 1244 pm->pm_gv.pm_savedvalue; 1245 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1246 } 1247 1248 PMCDBG(CSW,SWI,1,"cpu=%d ri=%d new=%jd", cpu, ri, newvalue); 1249 1250 md->pmd_write_pmc(cpu, ri, newvalue); 1251 md->pmd_start_pmc(cpu, ri); 1252 } 1253 1254 /* 1255 * perform any other architecture/cpu dependent thread 1256 * switch-in actions. 1257 */ 1258 1259 (void) (*md->pmd_switch_in)(pc, pp); 1260 1261 critical_exit(); 1262 1263 } 1264 1265 /* 1266 * Thread context switch OUT. 1267 */ 1268 1269 static void 1270 pmc_process_csw_out(struct thread *td) 1271 { 1272 int cpu; 1273 enum pmc_mode mode; 1274 unsigned int ri; 1275 struct pmc *pm; 1276 struct proc *p; 1277 struct pmc_cpu *pc; 1278 struct pmc_process *pp; 1279 int64_t tmp; 1280 pmc_value_t newvalue; 1281 1282 /* 1283 * Locate our process descriptor; this may be NULL if 1284 * this process is exiting and we have already removed 1285 * the process from the target process table. 1286 * 1287 * Note that due to kernel preemption, multiple 1288 * context switches may happen while the process is 1289 * exiting. 1290 * 1291 * Note also that if the target process cannot be 1292 * found we still need to deconfigure any PMCs that 1293 * are currently running on hardware. 1294 */ 1295 1296 p = td->td_proc; 1297 pp = pmc_find_process_descriptor(p, PMC_FLAG_NONE); 1298 1299 /* 1300 * save PMCs 1301 */ 1302 1303 critical_enter(); 1304 1305 cpu = PCPU_GET(cpuid); /* td->td_oncpu is invalid */ 1306 1307 PMCDBG(CSW,SWO,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p, 1308 p->p_pid, p->p_comm, pp); 1309 1310 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 1311 ("[pmc,%d wierd CPU id %d", __LINE__, cpu)); 1312 1313 pc = pmc_pcpu[cpu]; 1314 1315 /* 1316 * When a PMC gets unlinked from a target PMC, it will 1317 * be removed from the target's pp_pmc[] array. 1318 * 1319 * However, on a MP system, the target could have been 1320 * executing on another CPU at the time of the unlink. 1321 * So, at context switch OUT time, we need to look at 1322 * the hardware to determine if a PMC is scheduled on 1323 * it. 1324 */ 1325 1326 for (ri = 0; ri < md->pmd_npmc; ri++) { 1327 1328 pm = NULL; 1329 (void) (*md->pmd_get_config)(cpu, ri, &pm); 1330 1331 if (pm == NULL) /* nothing at this row index */ 1332 continue; 1333 1334 mode = PMC_TO_MODE(pm); 1335 if (!PMC_IS_VIRTUAL_MODE(mode)) 1336 continue; /* not a process virtual PMC */ 1337 1338 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 1339 ("[pmc,%d] ri mismatch pmc(%d) ri(%d)", 1340 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 1341 1342 /* Stop hardware if not already stopped */ 1343 if (pm->pm_stalled == 0) 1344 md->pmd_stop_pmc(cpu, ri); 1345 1346 /* reduce this PMC's runcount */ 1347 atomic_subtract_rel_32(&pm->pm_runcount, 1); 1348 1349 /* 1350 * If this PMC is associated with this process, 1351 * save the reading. 1352 */ 1353 1354 if (pp != NULL && pp->pp_pmcs[ri].pp_pmc != NULL) { 1355 1356 KASSERT(pm == pp->pp_pmcs[ri].pp_pmc, 1357 ("[pmc,%d] pm %p != pp_pmcs[%d] %p", __LINE__, 1358 pm, ri, pp->pp_pmcs[ri].pp_pmc)); 1359 1360 KASSERT(pp->pp_refcnt > 0, 1361 ("[pmc,%d] pp refcnt = %d", __LINE__, 1362 pp->pp_refcnt)); 1363 1364 md->pmd_read_pmc(cpu, ri, &newvalue); 1365 1366 tmp = newvalue - PMC_PCPU_SAVED(cpu,ri); 1367 1368 PMCDBG(CSW,SWI,1,"cpu=%d ri=%d tmp=%jd", cpu, ri, 1369 tmp); 1370 1371 if (mode == PMC_MODE_TS) { 1372 1373 /* 1374 * For sampling process-virtual PMCs, 1375 * we expect the count to be 1376 * decreasing as the 'value' 1377 * programmed into the PMC is the 1378 * number of events to be seen till 1379 * the next sampling interrupt. 1380 */ 1381 if (tmp < 0) 1382 tmp += pm->pm_sc.pm_reloadcount; 1383 mtx_pool_lock_spin(pmc_mtxpool, pm); 1384 pp->pp_pmcs[ri].pp_pmcval -= tmp; 1385 if ((int64_t) pp->pp_pmcs[ri].pp_pmcval < 0) 1386 pp->pp_pmcs[ri].pp_pmcval += 1387 pm->pm_sc.pm_reloadcount; 1388 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1389 1390 } else { 1391 1392 /* 1393 * For counting process-virtual PMCs, 1394 * we expect the count to be 1395 * increasing monotonically, modulo a 64 1396 * bit wraparound. 1397 */ 1398 KASSERT((int64_t) tmp >= 0, 1399 ("[pmc,%d] negative increment cpu=%d " 1400 "ri=%d newvalue=%jx saved=%jx " 1401 "incr=%jx", __LINE__, cpu, ri, 1402 newvalue, PMC_PCPU_SAVED(cpu,ri), tmp)); 1403 1404 mtx_pool_lock_spin(pmc_mtxpool, pm); 1405 pm->pm_gv.pm_savedvalue += tmp; 1406 pp->pp_pmcs[ri].pp_pmcval += tmp; 1407 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1408 1409 if (pm->pm_flags & PMC_F_LOG_PROCCSW) 1410 pmclog_process_proccsw(pm, pp, tmp); 1411 } 1412 } 1413 1414 /* mark hardware as free */ 1415 md->pmd_config_pmc(cpu, ri, NULL); 1416 } 1417 1418 /* 1419 * perform any other architecture/cpu dependent thread 1420 * switch out functions. 1421 */ 1422 1423 (void) (*md->pmd_switch_out)(pc, pp); 1424 1425 critical_exit(); 1426 } 1427 1428 /* 1429 * Log a KLD operation. 1430 */ 1431 1432 static void 1433 pmc_process_kld_load(struct pmckern_map_in *pkm) 1434 { 1435 struct pmc_owner *po; 1436 1437 sx_assert(&pmc_sx, SX_LOCKED); 1438 1439 /* 1440 * Notify owners of system sampling PMCs about KLD operations. 1441 */ 1442 1443 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1444 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1445 pmclog_process_map_in(po, (pid_t) -1, pkm->pm_address, 1446 (char *) pkm->pm_file); 1447 1448 /* 1449 * TODO: Notify owners of (all) process-sampling PMCs too. 1450 */ 1451 1452 return; 1453 } 1454 1455 static void 1456 pmc_process_kld_unload(struct pmckern_map_out *pkm) 1457 { 1458 struct pmc_owner *po; 1459 1460 sx_assert(&pmc_sx, SX_LOCKED); 1461 1462 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1463 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1464 pmclog_process_map_out(po, (pid_t) -1, 1465 pkm->pm_address, pkm->pm_address + pkm->pm_size); 1466 1467 /* 1468 * TODO: Notify owners of process-sampling PMCs. 1469 */ 1470 } 1471 1472 /* 1473 * A mapping change for a process. 1474 */ 1475 1476 static void 1477 pmc_process_mmap(struct thread *td, struct pmckern_map_in *pkm) 1478 { 1479 int ri; 1480 pid_t pid; 1481 char *fullpath, *freepath; 1482 const struct pmc *pm; 1483 struct pmc_owner *po; 1484 const struct pmc_process *pp; 1485 1486 freepath = fullpath = NULL; 1487 pmc_getfilename((struct vnode *) pkm->pm_file, &fullpath, &freepath); 1488 1489 pid = td->td_proc->p_pid; 1490 1491 /* Inform owners of all system-wide sampling PMCs. */ 1492 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1493 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1494 pmclog_process_map_in(po, pid, pkm->pm_address, fullpath); 1495 1496 if ((pp = pmc_find_process_descriptor(td->td_proc, 0)) == NULL) 1497 goto done; 1498 1499 /* 1500 * Inform sampling PMC owners tracking this process. 1501 */ 1502 for (ri = 0; ri < md->pmd_npmc; ri++) 1503 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL && 1504 PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 1505 pmclog_process_map_in(pm->pm_owner, 1506 pid, pkm->pm_address, fullpath); 1507 1508 done: 1509 if (freepath) 1510 free(freepath, M_TEMP); 1511 } 1512 1513 1514 /* 1515 * Log an munmap request. 1516 */ 1517 1518 static void 1519 pmc_process_munmap(struct thread *td, struct pmckern_map_out *pkm) 1520 { 1521 int ri; 1522 pid_t pid; 1523 struct pmc_owner *po; 1524 const struct pmc *pm; 1525 const struct pmc_process *pp; 1526 1527 pid = td->td_proc->p_pid; 1528 1529 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1530 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1531 pmclog_process_map_out(po, pid, pkm->pm_address, 1532 pkm->pm_address + pkm->pm_size); 1533 1534 if ((pp = pmc_find_process_descriptor(td->td_proc, 0)) == NULL) 1535 return; 1536 1537 for (ri = 0; ri < md->pmd_npmc; ri++) 1538 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL && 1539 PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 1540 pmclog_process_map_out(pm->pm_owner, pid, 1541 pkm->pm_address, pkm->pm_address + pkm->pm_size); 1542 } 1543 1544 /* 1545 * Log mapping information about the kernel. 1546 */ 1547 1548 static void 1549 pmc_log_kernel_mappings(struct pmc *pm) 1550 { 1551 struct pmc_owner *po; 1552 struct pmckern_map_in *km, *kmbase; 1553 1554 sx_assert(&pmc_sx, SX_LOCKED); 1555 KASSERT(PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)), 1556 ("[pmc,%d] non-sampling PMC (%p) desires mapping information", 1557 __LINE__, (void *) pm)); 1558 1559 po = pm->pm_owner; 1560 1561 if (po->po_flags & PMC_PO_INITIAL_MAPPINGS_DONE) 1562 return; 1563 1564 /* 1565 * Log the current set of kernel modules. 1566 */ 1567 kmbase = linker_hwpmc_list_objects(); 1568 for (km = kmbase; km->pm_file != NULL; km++) { 1569 PMCDBG(LOG,REG,1,"%s %p", (char *) km->pm_file, 1570 (void *) km->pm_address); 1571 pmclog_process_map_in(po, (pid_t) -1, km->pm_address, 1572 km->pm_file); 1573 } 1574 free(kmbase, M_LINKER); 1575 1576 po->po_flags |= PMC_PO_INITIAL_MAPPINGS_DONE; 1577 } 1578 1579 /* 1580 * Log the mappings for a single process. 1581 */ 1582 1583 static void 1584 pmc_log_process_mappings(struct pmc_owner *po, struct proc *p) 1585 { 1586 } 1587 1588 /* 1589 * Log mappings for all processes in the system. 1590 */ 1591 1592 static void 1593 pmc_log_all_process_mappings(struct pmc_owner *po) 1594 { 1595 struct proc *p, *top; 1596 1597 sx_assert(&pmc_sx, SX_XLOCKED); 1598 1599 if ((p = pfind(1)) == NULL) 1600 panic("[pmc,%d] Cannot find init", __LINE__); 1601 1602 PROC_UNLOCK(p); 1603 1604 sx_slock(&proctree_lock); 1605 1606 top = p; 1607 1608 for (;;) { 1609 pmc_log_process_mappings(po, p); 1610 if (!LIST_EMPTY(&p->p_children)) 1611 p = LIST_FIRST(&p->p_children); 1612 else for (;;) { 1613 if (p == top) 1614 goto done; 1615 if (LIST_NEXT(p, p_sibling)) { 1616 p = LIST_NEXT(p, p_sibling); 1617 break; 1618 } 1619 p = p->p_pptr; 1620 } 1621 } 1622 done: 1623 sx_sunlock(&proctree_lock); 1624 } 1625 1626 /* 1627 * The 'hook' invoked from the kernel proper 1628 */ 1629 1630 1631 #ifdef DEBUG 1632 const char *pmc_hooknames[] = { 1633 /* these strings correspond to PMC_FN_* in <sys/pmckern.h> */ 1634 "", 1635 "EXEC", 1636 "CSW-IN", 1637 "CSW-OUT", 1638 "SAMPLE", 1639 "KLDLOAD", 1640 "KLDUNLOAD", 1641 "MMAP", 1642 "MUNMAP", 1643 "CALLCHAIN" 1644 }; 1645 #endif 1646 1647 static int 1648 pmc_hook_handler(struct thread *td, int function, void *arg) 1649 { 1650 1651 PMCDBG(MOD,PMH,1, "hook td=%p func=%d \"%s\" arg=%p", td, function, 1652 pmc_hooknames[function], arg); 1653 1654 switch (function) 1655 { 1656 1657 /* 1658 * Process exec() 1659 */ 1660 1661 case PMC_FN_PROCESS_EXEC: 1662 { 1663 char *fullpath, *freepath; 1664 unsigned int ri; 1665 int is_using_hwpmcs; 1666 struct pmc *pm; 1667 struct proc *p; 1668 struct pmc_owner *po; 1669 struct pmc_process *pp; 1670 struct pmckern_procexec *pk; 1671 1672 sx_assert(&pmc_sx, SX_XLOCKED); 1673 1674 p = td->td_proc; 1675 pmc_getfilename(p->p_textvp, &fullpath, &freepath); 1676 1677 pk = (struct pmckern_procexec *) arg; 1678 1679 /* Inform owners of SS mode PMCs of the exec event. */ 1680 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1681 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1682 pmclog_process_procexec(po, PMC_ID_INVALID, 1683 p->p_pid, pk->pm_entryaddr, fullpath); 1684 1685 PROC_LOCK(p); 1686 is_using_hwpmcs = p->p_flag & P_HWPMC; 1687 PROC_UNLOCK(p); 1688 1689 if (!is_using_hwpmcs) { 1690 if (freepath) 1691 free(freepath, M_TEMP); 1692 break; 1693 } 1694 1695 /* 1696 * PMCs are not inherited across an exec(): remove any 1697 * PMCs that this process is the owner of. 1698 */ 1699 1700 if ((po = pmc_find_owner_descriptor(p)) != NULL) { 1701 pmc_remove_owner(po); 1702 pmc_destroy_owner_descriptor(po); 1703 } 1704 1705 /* 1706 * If the process being exec'ed is not the target of any 1707 * PMC, we are done. 1708 */ 1709 if ((pp = pmc_find_process_descriptor(p, 0)) == NULL) { 1710 if (freepath) 1711 free(freepath, M_TEMP); 1712 break; 1713 } 1714 1715 /* 1716 * Log the exec event to all monitoring owners. Skip 1717 * owners who have already recieved the event because 1718 * they had system sampling PMCs active. 1719 */ 1720 for (ri = 0; ri < md->pmd_npmc; ri++) 1721 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) { 1722 po = pm->pm_owner; 1723 if (po->po_sscount == 0 && 1724 po->po_flags & PMC_PO_OWNS_LOGFILE) 1725 pmclog_process_procexec(po, pm->pm_id, 1726 p->p_pid, pk->pm_entryaddr, 1727 fullpath); 1728 } 1729 1730 if (freepath) 1731 free(freepath, M_TEMP); 1732 1733 1734 PMCDBG(PRC,EXC,1, "exec proc=%p (%d, %s) cred-changed=%d", 1735 p, p->p_pid, p->p_comm, pk->pm_credentialschanged); 1736 1737 if (pk->pm_credentialschanged == 0) /* no change */ 1738 break; 1739 1740 /* 1741 * If the newly exec()'ed process has a different credential 1742 * than before, allow it to be the target of a PMC only if 1743 * the PMC's owner has sufficient priviledge. 1744 */ 1745 1746 for (ri = 0; ri < md->pmd_npmc; ri++) 1747 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) 1748 if (pmc_can_attach(pm, td->td_proc) != 0) 1749 pmc_detach_one_process(td->td_proc, 1750 pm, PMC_FLAG_NONE); 1751 1752 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt < (int) md->pmd_npmc, 1753 ("[pmc,%d] Illegal ref count %d on pp %p", __LINE__, 1754 pp->pp_refcnt, pp)); 1755 1756 /* 1757 * If this process is no longer the target of any 1758 * PMCs, we can remove the process entry and free 1759 * up space. 1760 */ 1761 1762 if (pp->pp_refcnt == 0) { 1763 pmc_remove_process_descriptor(pp); 1764 free(pp, M_PMC); 1765 break; 1766 } 1767 1768 } 1769 break; 1770 1771 case PMC_FN_CSW_IN: 1772 pmc_process_csw_in(td); 1773 break; 1774 1775 case PMC_FN_CSW_OUT: 1776 pmc_process_csw_out(td); 1777 break; 1778 1779 /* 1780 * Process accumulated PC samples. 1781 * 1782 * This function is expected to be called by hardclock() for 1783 * each CPU that has accumulated PC samples. 1784 * 1785 * This function is to be executed on the CPU whose samples 1786 * are being processed. 1787 */ 1788 case PMC_FN_DO_SAMPLES: 1789 1790 /* 1791 * Clear the cpu specific bit in the CPU mask before 1792 * do the rest of the processing. If the NMI handler 1793 * gets invoked after the "atomic_clear_int()" call 1794 * below but before "pmc_process_samples()" gets 1795 * around to processing the interrupt, then we will 1796 * come back here at the next hardclock() tick (and 1797 * may find nothing to do if "pmc_process_samples()" 1798 * had already processed the interrupt). We don't 1799 * lose the interrupt sample. 1800 */ 1801 atomic_clear_int(&pmc_cpumask, (1 << PCPU_GET(cpuid))); 1802 pmc_process_samples(PCPU_GET(cpuid)); 1803 break; 1804 1805 1806 case PMC_FN_KLD_LOAD: 1807 sx_assert(&pmc_sx, SX_LOCKED); 1808 pmc_process_kld_load((struct pmckern_map_in *) arg); 1809 break; 1810 1811 case PMC_FN_KLD_UNLOAD: 1812 sx_assert(&pmc_sx, SX_LOCKED); 1813 pmc_process_kld_unload((struct pmckern_map_out *) arg); 1814 break; 1815 1816 case PMC_FN_MMAP: 1817 sx_assert(&pmc_sx, SX_LOCKED); 1818 pmc_process_mmap(td, (struct pmckern_map_in *) arg); 1819 break; 1820 1821 case PMC_FN_MUNMAP: 1822 sx_assert(&pmc_sx, SX_LOCKED); 1823 pmc_process_munmap(td, (struct pmckern_map_out *) arg); 1824 break; 1825 1826 case PMC_FN_USER_CALLCHAIN: 1827 /* 1828 * Record a call chain. 1829 */ 1830 pmc_capture_user_callchain(PCPU_GET(cpuid), 1831 (struct trapframe *) arg); 1832 break; 1833 1834 default: 1835 #ifdef DEBUG 1836 KASSERT(0, ("[pmc,%d] unknown hook %d\n", __LINE__, function)); 1837 #endif 1838 break; 1839 1840 } 1841 1842 return 0; 1843 } 1844 1845 /* 1846 * allocate a 'struct pmc_owner' descriptor in the owner hash table. 1847 */ 1848 1849 static struct pmc_owner * 1850 pmc_allocate_owner_descriptor(struct proc *p) 1851 { 1852 uint32_t hindex; 1853 struct pmc_owner *po; 1854 struct pmc_ownerhash *poh; 1855 1856 hindex = PMC_HASH_PTR(p, pmc_ownerhashmask); 1857 poh = &pmc_ownerhash[hindex]; 1858 1859 /* allocate space for N pointers and one descriptor struct */ 1860 po = malloc(sizeof(struct pmc_owner), M_PMC, M_ZERO|M_WAITOK); 1861 1862 po->po_sscount = po->po_error = po->po_flags = 0; 1863 po->po_file = NULL; 1864 po->po_owner = p; 1865 po->po_kthread = NULL; 1866 LIST_INIT(&po->po_pmcs); 1867 LIST_INSERT_HEAD(poh, po, po_next); /* insert into hash table */ 1868 1869 TAILQ_INIT(&po->po_logbuffers); 1870 mtx_init(&po->po_mtx, "pmc-owner-mtx", "pmc-per-proc", MTX_SPIN); 1871 1872 PMCDBG(OWN,ALL,1, "allocate-owner proc=%p (%d, %s) pmc-owner=%p", 1873 p, p->p_pid, p->p_comm, po); 1874 1875 return po; 1876 } 1877 1878 static void 1879 pmc_destroy_owner_descriptor(struct pmc_owner *po) 1880 { 1881 1882 PMCDBG(OWN,REL,1, "destroy-owner po=%p proc=%p (%d, %s)", 1883 po, po->po_owner, po->po_owner->p_pid, po->po_owner->p_comm); 1884 1885 mtx_destroy(&po->po_mtx); 1886 free(po, M_PMC); 1887 } 1888 1889 /* 1890 * find the descriptor corresponding to process 'p', adding or removing it 1891 * as specified by 'mode'. 1892 */ 1893 1894 static struct pmc_process * 1895 pmc_find_process_descriptor(struct proc *p, uint32_t mode) 1896 { 1897 uint32_t hindex; 1898 struct pmc_process *pp, *ppnew; 1899 struct pmc_processhash *pph; 1900 1901 hindex = PMC_HASH_PTR(p, pmc_processhashmask); 1902 pph = &pmc_processhash[hindex]; 1903 1904 ppnew = NULL; 1905 1906 /* 1907 * Pre-allocate memory in the FIND_ALLOCATE case since we 1908 * cannot call malloc(9) once we hold a spin lock. 1909 */ 1910 1911 if (mode & PMC_FLAG_ALLOCATE) { 1912 /* allocate additional space for 'n' pmc pointers */ 1913 ppnew = malloc(sizeof(struct pmc_process) + md->pmd_npmc * 1914 sizeof(struct pmc_targetstate), M_PMC, M_ZERO|M_WAITOK); 1915 } 1916 1917 mtx_lock_spin(&pmc_processhash_mtx); 1918 LIST_FOREACH(pp, pph, pp_next) 1919 if (pp->pp_proc == p) 1920 break; 1921 1922 if ((mode & PMC_FLAG_REMOVE) && pp != NULL) 1923 LIST_REMOVE(pp, pp_next); 1924 1925 if ((mode & PMC_FLAG_ALLOCATE) && pp == NULL && 1926 ppnew != NULL) { 1927 ppnew->pp_proc = p; 1928 LIST_INSERT_HEAD(pph, ppnew, pp_next); 1929 pp = ppnew; 1930 ppnew = NULL; 1931 } 1932 mtx_unlock_spin(&pmc_processhash_mtx); 1933 1934 if (pp != NULL && ppnew != NULL) 1935 free(ppnew, M_PMC); 1936 1937 return pp; 1938 } 1939 1940 /* 1941 * remove a process descriptor from the process hash table. 1942 */ 1943 1944 static void 1945 pmc_remove_process_descriptor(struct pmc_process *pp) 1946 { 1947 KASSERT(pp->pp_refcnt == 0, 1948 ("[pmc,%d] Removing process descriptor %p with count %d", 1949 __LINE__, pp, pp->pp_refcnt)); 1950 1951 mtx_lock_spin(&pmc_processhash_mtx); 1952 LIST_REMOVE(pp, pp_next); 1953 mtx_unlock_spin(&pmc_processhash_mtx); 1954 } 1955 1956 1957 /* 1958 * find an owner descriptor corresponding to proc 'p' 1959 */ 1960 1961 static struct pmc_owner * 1962 pmc_find_owner_descriptor(struct proc *p) 1963 { 1964 uint32_t hindex; 1965 struct pmc_owner *po; 1966 struct pmc_ownerhash *poh; 1967 1968 hindex = PMC_HASH_PTR(p, pmc_ownerhashmask); 1969 poh = &pmc_ownerhash[hindex]; 1970 1971 po = NULL; 1972 LIST_FOREACH(po, poh, po_next) 1973 if (po->po_owner == p) 1974 break; 1975 1976 PMCDBG(OWN,FND,1, "find-owner proc=%p (%d, %s) hindex=0x%x -> " 1977 "pmc-owner=%p", p, p->p_pid, p->p_comm, hindex, po); 1978 1979 return po; 1980 } 1981 1982 /* 1983 * pmc_allocate_pmc_descriptor 1984 * 1985 * Allocate a pmc descriptor and initialize its 1986 * fields. 1987 */ 1988 1989 static struct pmc * 1990 pmc_allocate_pmc_descriptor(void) 1991 { 1992 struct pmc *pmc; 1993 1994 pmc = malloc(sizeof(struct pmc), M_PMC, M_ZERO|M_WAITOK); 1995 1996 if (pmc != NULL) { 1997 pmc->pm_owner = NULL; 1998 LIST_INIT(&pmc->pm_targets); 1999 } 2000 2001 PMCDBG(PMC,ALL,1, "allocate-pmc -> pmc=%p", pmc); 2002 2003 return pmc; 2004 } 2005 2006 /* 2007 * Destroy a pmc descriptor. 2008 */ 2009 2010 static void 2011 pmc_destroy_pmc_descriptor(struct pmc *pm) 2012 { 2013 (void) pm; 2014 2015 #ifdef DEBUG 2016 KASSERT(pm->pm_state == PMC_STATE_DELETED || 2017 pm->pm_state == PMC_STATE_FREE, 2018 ("[pmc,%d] destroying non-deleted PMC", __LINE__)); 2019 KASSERT(LIST_EMPTY(&pm->pm_targets), 2020 ("[pmc,%d] destroying pmc with targets", __LINE__)); 2021 KASSERT(pm->pm_owner == NULL, 2022 ("[pmc,%d] destroying pmc attached to an owner", __LINE__)); 2023 KASSERT(pm->pm_runcount == 0, 2024 ("[pmc,%d] pmc has non-zero run count %d", __LINE__, 2025 pm->pm_runcount)); 2026 #endif 2027 } 2028 2029 static void 2030 pmc_wait_for_pmc_idle(struct pmc *pm) 2031 { 2032 #ifdef DEBUG 2033 volatile int maxloop; 2034 2035 maxloop = 100 * pmc_cpu_max(); 2036 #endif 2037 2038 /* 2039 * Loop (with a forced context switch) till the PMC's runcount 2040 * comes down to zero. 2041 */ 2042 while (atomic_load_acq_32(&pm->pm_runcount) > 0) { 2043 #ifdef DEBUG 2044 maxloop--; 2045 KASSERT(maxloop > 0, 2046 ("[pmc,%d] (ri%d, rc%d) waiting too long for " 2047 "pmc to be free", __LINE__, 2048 PMC_TO_ROWINDEX(pm), pm->pm_runcount)); 2049 #endif 2050 pmc_force_context_switch(); 2051 } 2052 } 2053 2054 /* 2055 * This function does the following things: 2056 * 2057 * - detaches the PMC from hardware 2058 * - unlinks all target threads that were attached to it 2059 * - removes the PMC from its owner's list 2060 * - destroy's the PMC private mutex 2061 * 2062 * Once this function completes, the given pmc pointer can be safely 2063 * FREE'd by the caller. 2064 */ 2065 2066 static void 2067 pmc_release_pmc_descriptor(struct pmc *pm) 2068 { 2069 u_int ri, cpu; 2070 enum pmc_mode mode; 2071 struct pmc_hw *phw; 2072 struct pmc_owner *po; 2073 struct pmc_process *pp; 2074 struct pmc_target *ptgt, *tmp; 2075 struct pmc_binding pb; 2076 2077 sx_assert(&pmc_sx, SX_XLOCKED); 2078 2079 KASSERT(pm, ("[pmc,%d] null pmc", __LINE__)); 2080 2081 ri = PMC_TO_ROWINDEX(pm); 2082 mode = PMC_TO_MODE(pm); 2083 2084 PMCDBG(PMC,REL,1, "release-pmc pmc=%p ri=%d mode=%d", pm, ri, 2085 mode); 2086 2087 /* 2088 * First, we take the PMC off hardware. 2089 */ 2090 cpu = 0; 2091 if (PMC_IS_SYSTEM_MODE(mode)) { 2092 2093 /* 2094 * A system mode PMC runs on a specific CPU. Switch 2095 * to this CPU and turn hardware off. 2096 */ 2097 pmc_save_cpu_binding(&pb); 2098 2099 cpu = PMC_TO_CPU(pm); 2100 2101 pmc_select_cpu(cpu); 2102 2103 /* switch off non-stalled CPUs */ 2104 if (pm->pm_state == PMC_STATE_RUNNING && 2105 pm->pm_stalled == 0) { 2106 2107 phw = pmc_pcpu[cpu]->pc_hwpmcs[ri]; 2108 2109 KASSERT(phw->phw_pmc == pm, 2110 ("[pmc, %d] pmc ptr ri(%d) hw(%p) pm(%p)", 2111 __LINE__, ri, phw->phw_pmc, pm)); 2112 PMCDBG(PMC,REL,2, "stopping cpu=%d ri=%d", cpu, ri); 2113 2114 critical_enter(); 2115 md->pmd_stop_pmc(cpu, ri); 2116 critical_exit(); 2117 } 2118 2119 PMCDBG(PMC,REL,2, "decfg cpu=%d ri=%d", cpu, ri); 2120 2121 critical_enter(); 2122 md->pmd_config_pmc(cpu, ri, NULL); 2123 critical_exit(); 2124 2125 /* adjust the global and process count of SS mode PMCs */ 2126 if (mode == PMC_MODE_SS && pm->pm_state == PMC_STATE_RUNNING) { 2127 po = pm->pm_owner; 2128 po->po_sscount--; 2129 if (po->po_sscount == 0) { 2130 atomic_subtract_rel_int(&pmc_ss_count, 1); 2131 LIST_REMOVE(po, po_ssnext); 2132 } 2133 } 2134 2135 pm->pm_state = PMC_STATE_DELETED; 2136 2137 pmc_restore_cpu_binding(&pb); 2138 2139 /* 2140 * We could have references to this PMC structure in 2141 * the per-cpu sample queues. Wait for the queue to 2142 * drain. 2143 */ 2144 pmc_wait_for_pmc_idle(pm); 2145 2146 } else if (PMC_IS_VIRTUAL_MODE(mode)) { 2147 2148 /* 2149 * A virtual PMC could be running on multiple CPUs at 2150 * a given instant. 2151 * 2152 * By marking its state as DELETED, we ensure that 2153 * this PMC is never further scheduled on hardware. 2154 * 2155 * Then we wait till all CPUs are done with this PMC. 2156 */ 2157 pm->pm_state = PMC_STATE_DELETED; 2158 2159 2160 /* Wait for the PMCs runcount to come to zero. */ 2161 pmc_wait_for_pmc_idle(pm); 2162 2163 /* 2164 * At this point the PMC is off all CPUs and cannot be 2165 * freshly scheduled onto a CPU. It is now safe to 2166 * unlink all targets from this PMC. If a 2167 * process-record's refcount falls to zero, we remove 2168 * it from the hash table. The module-wide SX lock 2169 * protects us from races. 2170 */ 2171 LIST_FOREACH_SAFE(ptgt, &pm->pm_targets, pt_next, tmp) { 2172 pp = ptgt->pt_process; 2173 pmc_unlink_target_process(pm, pp); /* frees 'ptgt' */ 2174 2175 PMCDBG(PMC,REL,3, "pp->refcnt=%d", pp->pp_refcnt); 2176 2177 /* 2178 * If the target process record shows that no 2179 * PMCs are attached to it, reclaim its space. 2180 */ 2181 2182 if (pp->pp_refcnt == 0) { 2183 pmc_remove_process_descriptor(pp); 2184 free(pp, M_PMC); 2185 } 2186 } 2187 2188 cpu = curthread->td_oncpu; /* setup cpu for pmd_release() */ 2189 2190 } 2191 2192 /* 2193 * Release any MD resources 2194 */ 2195 2196 (void) md->pmd_release_pmc(cpu, ri, pm); 2197 2198 /* 2199 * Update row disposition 2200 */ 2201 2202 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) 2203 PMC_UNMARK_ROW_STANDALONE(ri); 2204 else 2205 PMC_UNMARK_ROW_THREAD(ri); 2206 2207 /* unlink from the owner's list */ 2208 if (pm->pm_owner) { 2209 LIST_REMOVE(pm, pm_next); 2210 pm->pm_owner = NULL; 2211 } 2212 2213 pmc_destroy_pmc_descriptor(pm); 2214 } 2215 2216 /* 2217 * Register an owner and a pmc. 2218 */ 2219 2220 static int 2221 pmc_register_owner(struct proc *p, struct pmc *pmc) 2222 { 2223 struct pmc_owner *po; 2224 2225 sx_assert(&pmc_sx, SX_XLOCKED); 2226 2227 if ((po = pmc_find_owner_descriptor(p)) == NULL) 2228 if ((po = pmc_allocate_owner_descriptor(p)) == NULL) 2229 return ENOMEM; 2230 2231 KASSERT(pmc->pm_owner == NULL, 2232 ("[pmc,%d] attempting to own an initialized PMC", __LINE__)); 2233 pmc->pm_owner = po; 2234 2235 LIST_INSERT_HEAD(&po->po_pmcs, pmc, pm_next); 2236 2237 PROC_LOCK(p); 2238 p->p_flag |= P_HWPMC; 2239 PROC_UNLOCK(p); 2240 2241 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 2242 pmclog_process_pmcallocate(pmc); 2243 2244 PMCDBG(PMC,REG,1, "register-owner pmc-owner=%p pmc=%p", 2245 po, pmc); 2246 2247 return 0; 2248 } 2249 2250 /* 2251 * Return the current row disposition: 2252 * == 0 => FREE 2253 * > 0 => PROCESS MODE 2254 * < 0 => SYSTEM MODE 2255 */ 2256 2257 int 2258 pmc_getrowdisp(int ri) 2259 { 2260 return pmc_pmcdisp[ri]; 2261 } 2262 2263 /* 2264 * Check if a PMC at row index 'ri' can be allocated to the current 2265 * process. 2266 * 2267 * Allocation can fail if: 2268 * - the current process is already being profiled by a PMC at index 'ri', 2269 * attached to it via OP_PMCATTACH. 2270 * - the current process has already allocated a PMC at index 'ri' 2271 * via OP_ALLOCATE. 2272 */ 2273 2274 static int 2275 pmc_can_allocate_rowindex(struct proc *p, unsigned int ri, int cpu) 2276 { 2277 enum pmc_mode mode; 2278 struct pmc *pm; 2279 struct pmc_owner *po; 2280 struct pmc_process *pp; 2281 2282 PMCDBG(PMC,ALR,1, "can-allocate-rowindex proc=%p (%d, %s) ri=%d " 2283 "cpu=%d", p, p->p_pid, p->p_comm, ri, cpu); 2284 2285 /* 2286 * We shouldn't have already allocated a process-mode PMC at 2287 * row index 'ri'. 2288 * 2289 * We shouldn't have allocated a system-wide PMC on the same 2290 * CPU and same RI. 2291 */ 2292 if ((po = pmc_find_owner_descriptor(p)) != NULL) 2293 LIST_FOREACH(pm, &po->po_pmcs, pm_next) { 2294 if (PMC_TO_ROWINDEX(pm) == ri) { 2295 mode = PMC_TO_MODE(pm); 2296 if (PMC_IS_VIRTUAL_MODE(mode)) 2297 return EEXIST; 2298 if (PMC_IS_SYSTEM_MODE(mode) && 2299 (int) PMC_TO_CPU(pm) == cpu) 2300 return EEXIST; 2301 } 2302 } 2303 2304 /* 2305 * We also shouldn't be the target of any PMC at this index 2306 * since otherwise a PMC_ATTACH to ourselves will fail. 2307 */ 2308 if ((pp = pmc_find_process_descriptor(p, 0)) != NULL) 2309 if (pp->pp_pmcs[ri].pp_pmc) 2310 return EEXIST; 2311 2312 PMCDBG(PMC,ALR,2, "can-allocate-rowindex proc=%p (%d, %s) ri=%d ok", 2313 p, p->p_pid, p->p_comm, ri); 2314 2315 return 0; 2316 } 2317 2318 /* 2319 * Check if a given PMC at row index 'ri' can be currently used in 2320 * mode 'mode'. 2321 */ 2322 2323 static int 2324 pmc_can_allocate_row(int ri, enum pmc_mode mode) 2325 { 2326 enum pmc_disp disp; 2327 2328 sx_assert(&pmc_sx, SX_XLOCKED); 2329 2330 PMCDBG(PMC,ALR,1, "can-allocate-row ri=%d mode=%d", ri, mode); 2331 2332 if (PMC_IS_SYSTEM_MODE(mode)) 2333 disp = PMC_DISP_STANDALONE; 2334 else 2335 disp = PMC_DISP_THREAD; 2336 2337 /* 2338 * check disposition for PMC row 'ri': 2339 * 2340 * Expected disposition Row-disposition Result 2341 * 2342 * STANDALONE STANDALONE or FREE proceed 2343 * STANDALONE THREAD fail 2344 * THREAD THREAD or FREE proceed 2345 * THREAD STANDALONE fail 2346 */ 2347 2348 if (!PMC_ROW_DISP_IS_FREE(ri) && 2349 !(disp == PMC_DISP_THREAD && PMC_ROW_DISP_IS_THREAD(ri)) && 2350 !(disp == PMC_DISP_STANDALONE && PMC_ROW_DISP_IS_STANDALONE(ri))) 2351 return EBUSY; 2352 2353 /* 2354 * All OK 2355 */ 2356 2357 PMCDBG(PMC,ALR,2, "can-allocate-row ri=%d mode=%d ok", ri, mode); 2358 2359 return 0; 2360 2361 } 2362 2363 /* 2364 * Find a PMC descriptor with user handle 'pmcid' for thread 'td'. 2365 */ 2366 2367 static struct pmc * 2368 pmc_find_pmc_descriptor_in_process(struct pmc_owner *po, pmc_id_t pmcid) 2369 { 2370 struct pmc *pm; 2371 2372 KASSERT(PMC_ID_TO_ROWINDEX(pmcid) < md->pmd_npmc, 2373 ("[pmc,%d] Illegal pmc index %d (max %d)", __LINE__, 2374 PMC_ID_TO_ROWINDEX(pmcid), md->pmd_npmc)); 2375 2376 LIST_FOREACH(pm, &po->po_pmcs, pm_next) 2377 if (pm->pm_id == pmcid) 2378 return pm; 2379 2380 return NULL; 2381 } 2382 2383 static int 2384 pmc_find_pmc(pmc_id_t pmcid, struct pmc **pmc) 2385 { 2386 2387 struct pmc *pm; 2388 struct pmc_owner *po; 2389 2390 PMCDBG(PMC,FND,1, "find-pmc id=%d", pmcid); 2391 2392 if ((po = pmc_find_owner_descriptor(curthread->td_proc)) == NULL) 2393 return ESRCH; 2394 2395 if ((pm = pmc_find_pmc_descriptor_in_process(po, pmcid)) == NULL) 2396 return EINVAL; 2397 2398 PMCDBG(PMC,FND,2, "find-pmc id=%d -> pmc=%p", pmcid, pm); 2399 2400 *pmc = pm; 2401 return 0; 2402 } 2403 2404 /* 2405 * Start a PMC. 2406 */ 2407 2408 static int 2409 pmc_start(struct pmc *pm) 2410 { 2411 int error, cpu, ri; 2412 enum pmc_mode mode; 2413 struct pmc_owner *po; 2414 struct pmc_binding pb; 2415 2416 KASSERT(pm != NULL, 2417 ("[pmc,%d] null pm", __LINE__)); 2418 2419 mode = PMC_TO_MODE(pm); 2420 ri = PMC_TO_ROWINDEX(pm); 2421 error = 0; 2422 2423 PMCDBG(PMC,OPS,1, "start pmc=%p mode=%d ri=%d", pm, mode, ri); 2424 2425 po = pm->pm_owner; 2426 2427 /* 2428 * Disallow PMCSTART if a logfile is required but has not been 2429 * configured yet. 2430 */ 2431 if ((pm->pm_flags & PMC_F_NEEDS_LOGFILE) && 2432 (po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) 2433 return EDOOFUS; /* programming error */ 2434 2435 /* 2436 * If this is a sampling mode PMC, log mapping information for 2437 * the kernel modules that are currently loaded. 2438 */ 2439 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 2440 pmc_log_kernel_mappings(pm); 2441 2442 if (PMC_IS_VIRTUAL_MODE(mode)) { 2443 2444 /* 2445 * If a PMCATTACH has never been done on this PMC, 2446 * attach it to its owner process. 2447 */ 2448 2449 if (LIST_EMPTY(&pm->pm_targets)) 2450 error = (pm->pm_flags & PMC_F_ATTACH_DONE) ? ESRCH : 2451 pmc_attach_process(po->po_owner, pm); 2452 2453 /* 2454 * If the PMC is attached to its owner, then force a context 2455 * switch to ensure that the MD state gets set correctly. 2456 */ 2457 2458 if (error == 0) { 2459 pm->pm_state = PMC_STATE_RUNNING; 2460 if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) 2461 pmc_force_context_switch(); 2462 } 2463 2464 return error; 2465 } 2466 2467 2468 /* 2469 * A system-wide PMC. 2470 * 2471 * Add the owner to the global list if this is a system-wide 2472 * sampling PMC. 2473 */ 2474 2475 if (mode == PMC_MODE_SS) { 2476 if (po->po_sscount == 0) { 2477 LIST_INSERT_HEAD(&pmc_ss_owners, po, po_ssnext); 2478 atomic_add_rel_int(&pmc_ss_count, 1); 2479 PMCDBG(PMC,OPS,1, "po=%p in global list", po); 2480 } 2481 po->po_sscount++; 2482 } 2483 2484 /* Log mapping information for all processes in the system. */ 2485 pmc_log_all_process_mappings(po); 2486 2487 /* 2488 * Move to the CPU associated with this 2489 * PMC, and start the hardware. 2490 */ 2491 2492 pmc_save_cpu_binding(&pb); 2493 2494 cpu = PMC_TO_CPU(pm); 2495 2496 if (!pmc_cpu_is_active(cpu)) 2497 return ENXIO; 2498 2499 pmc_select_cpu(cpu); 2500 2501 /* 2502 * global PMCs are configured at allocation time 2503 * so write out the initial value and start the PMC. 2504 */ 2505 2506 pm->pm_state = PMC_STATE_RUNNING; 2507 2508 critical_enter(); 2509 if ((error = md->pmd_write_pmc(cpu, ri, 2510 PMC_IS_SAMPLING_MODE(mode) ? 2511 pm->pm_sc.pm_reloadcount : 2512 pm->pm_sc.pm_initial)) == 0) 2513 error = md->pmd_start_pmc(cpu, ri); 2514 critical_exit(); 2515 2516 pmc_restore_cpu_binding(&pb); 2517 2518 return error; 2519 } 2520 2521 /* 2522 * Stop a PMC. 2523 */ 2524 2525 static int 2526 pmc_stop(struct pmc *pm) 2527 { 2528 int cpu, error, ri; 2529 struct pmc_owner *po; 2530 struct pmc_binding pb; 2531 2532 KASSERT(pm != NULL, ("[pmc,%d] null pmc", __LINE__)); 2533 2534 PMCDBG(PMC,OPS,1, "stop pmc=%p mode=%d ri=%d", pm, 2535 PMC_TO_MODE(pm), PMC_TO_ROWINDEX(pm)); 2536 2537 pm->pm_state = PMC_STATE_STOPPED; 2538 2539 /* 2540 * If the PMC is a virtual mode one, changing the state to 2541 * non-RUNNING is enough to ensure that the PMC never gets 2542 * scheduled. 2543 * 2544 * If this PMC is current running on a CPU, then it will 2545 * handled correctly at the time its target process is context 2546 * switched out. 2547 */ 2548 2549 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) 2550 return 0; 2551 2552 /* 2553 * A system-mode PMC. Move to the CPU associated with 2554 * this PMC, and stop the hardware. We update the 2555 * 'initial count' so that a subsequent PMCSTART will 2556 * resume counting from the current hardware count. 2557 */ 2558 2559 pmc_save_cpu_binding(&pb); 2560 2561 cpu = PMC_TO_CPU(pm); 2562 2563 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 2564 ("[pmc,%d] illegal cpu=%d", __LINE__, cpu)); 2565 2566 if (!pmc_cpu_is_active(cpu)) 2567 return ENXIO; 2568 2569 pmc_select_cpu(cpu); 2570 2571 ri = PMC_TO_ROWINDEX(pm); 2572 2573 critical_enter(); 2574 if ((error = md->pmd_stop_pmc(cpu, ri)) == 0) 2575 error = md->pmd_read_pmc(cpu, ri, &pm->pm_sc.pm_initial); 2576 critical_exit(); 2577 2578 pmc_restore_cpu_binding(&pb); 2579 2580 po = pm->pm_owner; 2581 2582 /* remove this owner from the global list of SS PMC owners */ 2583 if (PMC_TO_MODE(pm) == PMC_MODE_SS) { 2584 po->po_sscount--; 2585 if (po->po_sscount == 0) { 2586 atomic_subtract_rel_int(&pmc_ss_count, 1); 2587 LIST_REMOVE(po, po_ssnext); 2588 PMCDBG(PMC,OPS,2,"po=%p removed from global list", po); 2589 } 2590 } 2591 2592 return error; 2593 } 2594 2595 2596 #ifdef DEBUG 2597 static const char *pmc_op_to_name[] = { 2598 #undef __PMC_OP 2599 #define __PMC_OP(N, D) #N , 2600 __PMC_OPS() 2601 NULL 2602 }; 2603 #endif 2604 2605 /* 2606 * The syscall interface 2607 */ 2608 2609 #define PMC_GET_SX_XLOCK(...) do { \ 2610 sx_xlock(&pmc_sx); \ 2611 if (pmc_hook == NULL) { \ 2612 sx_xunlock(&pmc_sx); \ 2613 return __VA_ARGS__; \ 2614 } \ 2615 } while (0) 2616 2617 #define PMC_DOWNGRADE_SX() do { \ 2618 sx_downgrade(&pmc_sx); \ 2619 is_sx_downgraded = 1; \ 2620 } while (0) 2621 2622 static int 2623 pmc_syscall_handler(struct thread *td, void *syscall_args) 2624 { 2625 int error, is_sx_downgraded, op; 2626 struct pmc_syscall_args *c; 2627 void *arg; 2628 2629 PMC_GET_SX_XLOCK(ENOSYS); 2630 2631 DROP_GIANT(); 2632 2633 is_sx_downgraded = 0; 2634 2635 c = (struct pmc_syscall_args *) syscall_args; 2636 2637 op = c->pmop_code; 2638 arg = c->pmop_data; 2639 2640 PMCDBG(MOD,PMS,1, "syscall op=%d \"%s\" arg=%p", op, 2641 pmc_op_to_name[op], arg); 2642 2643 error = 0; 2644 atomic_add_int(&pmc_stats.pm_syscalls, 1); 2645 2646 switch(op) 2647 { 2648 2649 2650 /* 2651 * Configure a log file. 2652 * 2653 * XXX This OP will be reworked. 2654 */ 2655 2656 case PMC_OP_CONFIGURELOG: 2657 { 2658 struct proc *p; 2659 struct pmc *pm; 2660 struct pmc_owner *po; 2661 struct pmc_op_configurelog cl; 2662 2663 sx_assert(&pmc_sx, SX_XLOCKED); 2664 2665 if ((error = copyin(arg, &cl, sizeof(cl))) != 0) 2666 break; 2667 2668 /* mark this process as owning a log file */ 2669 p = td->td_proc; 2670 if ((po = pmc_find_owner_descriptor(p)) == NULL) 2671 if ((po = pmc_allocate_owner_descriptor(p)) == NULL) { 2672 error = ENOMEM; 2673 break; 2674 } 2675 2676 /* 2677 * If a valid fd was passed in, try to configure that, 2678 * otherwise if 'fd' was less than zero and there was 2679 * a log file configured, flush its buffers and 2680 * de-configure it. 2681 */ 2682 if (cl.pm_logfd >= 0) 2683 error = pmclog_configure_log(po, cl.pm_logfd); 2684 else if (po->po_flags & PMC_PO_OWNS_LOGFILE) { 2685 pmclog_process_closelog(po); 2686 error = pmclog_flush(po); 2687 if (error == 0) { 2688 LIST_FOREACH(pm, &po->po_pmcs, pm_next) 2689 if (pm->pm_flags & PMC_F_NEEDS_LOGFILE && 2690 pm->pm_state == PMC_STATE_RUNNING) 2691 pmc_stop(pm); 2692 error = pmclog_deconfigure_log(po); 2693 } 2694 } else 2695 error = EINVAL; 2696 2697 if (error) 2698 break; 2699 } 2700 break; 2701 2702 2703 /* 2704 * Flush a log file. 2705 */ 2706 2707 case PMC_OP_FLUSHLOG: 2708 { 2709 struct pmc_owner *po; 2710 2711 sx_assert(&pmc_sx, SX_XLOCKED); 2712 2713 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 2714 error = EINVAL; 2715 break; 2716 } 2717 2718 error = pmclog_flush(po); 2719 } 2720 break; 2721 2722 /* 2723 * Retrieve hardware configuration. 2724 */ 2725 2726 case PMC_OP_GETCPUINFO: /* CPU information */ 2727 { 2728 struct pmc_op_getcpuinfo gci; 2729 2730 gci.pm_cputype = md->pmd_cputype; 2731 gci.pm_ncpu = pmc_cpu_max(); 2732 gci.pm_npmc = md->pmd_npmc; 2733 gci.pm_nclass = md->pmd_nclass; 2734 bcopy(md->pmd_classes, &gci.pm_classes, 2735 sizeof(gci.pm_classes)); 2736 error = copyout(&gci, arg, sizeof(gci)); 2737 } 2738 break; 2739 2740 2741 /* 2742 * Get module statistics 2743 */ 2744 2745 case PMC_OP_GETDRIVERSTATS: 2746 { 2747 struct pmc_op_getdriverstats gms; 2748 2749 bcopy(&pmc_stats, &gms, sizeof(gms)); 2750 error = copyout(&gms, arg, sizeof(gms)); 2751 } 2752 break; 2753 2754 2755 /* 2756 * Retrieve module version number 2757 */ 2758 2759 case PMC_OP_GETMODULEVERSION: 2760 { 2761 uint32_t cv, modv; 2762 2763 /* retrieve the client's idea of the ABI version */ 2764 if ((error = copyin(arg, &cv, sizeof(uint32_t))) != 0) 2765 break; 2766 /* don't service clients newer than our driver */ 2767 modv = PMC_VERSION; 2768 if ((cv & 0xFFFF0000) > (modv & 0xFFFF0000)) { 2769 error = EPROGMISMATCH; 2770 break; 2771 } 2772 error = copyout(&modv, arg, sizeof(int)); 2773 } 2774 break; 2775 2776 2777 /* 2778 * Retrieve the state of all the PMCs on a given 2779 * CPU. 2780 */ 2781 2782 case PMC_OP_GETPMCINFO: 2783 { 2784 uint32_t cpu, n, npmc; 2785 size_t pmcinfo_size; 2786 struct pmc *pm; 2787 struct pmc_info *p, *pmcinfo; 2788 struct pmc_op_getpmcinfo *gpi; 2789 struct pmc_owner *po; 2790 struct pmc_binding pb; 2791 2792 PMC_DOWNGRADE_SX(); 2793 2794 gpi = (struct pmc_op_getpmcinfo *) arg; 2795 2796 if ((error = copyin(&gpi->pm_cpu, &cpu, sizeof(cpu))) != 0) 2797 break; 2798 2799 if (cpu >= pmc_cpu_max()) { 2800 error = EINVAL; 2801 break; 2802 } 2803 2804 if (!pmc_cpu_is_active(cpu)) { 2805 error = ENXIO; 2806 break; 2807 } 2808 2809 /* switch to CPU 'cpu' */ 2810 pmc_save_cpu_binding(&pb); 2811 pmc_select_cpu(cpu); 2812 2813 npmc = md->pmd_npmc; 2814 2815 pmcinfo_size = npmc * sizeof(struct pmc_info); 2816 pmcinfo = malloc(pmcinfo_size, M_PMC, M_WAITOK); 2817 2818 p = pmcinfo; 2819 2820 for (n = 0; n < md->pmd_npmc; n++, p++) { 2821 2822 if ((error = md->pmd_describe(cpu, n, p, &pm)) != 0) 2823 break; 2824 2825 if (PMC_ROW_DISP_IS_STANDALONE(n)) 2826 p->pm_rowdisp = PMC_DISP_STANDALONE; 2827 else if (PMC_ROW_DISP_IS_THREAD(n)) 2828 p->pm_rowdisp = PMC_DISP_THREAD; 2829 else 2830 p->pm_rowdisp = PMC_DISP_FREE; 2831 2832 p->pm_ownerpid = -1; 2833 2834 if (pm == NULL) /* no PMC associated */ 2835 continue; 2836 2837 po = pm->pm_owner; 2838 2839 KASSERT(po->po_owner != NULL, 2840 ("[pmc,%d] pmc_owner had a null proc pointer", 2841 __LINE__)); 2842 2843 p->pm_ownerpid = po->po_owner->p_pid; 2844 p->pm_mode = PMC_TO_MODE(pm); 2845 p->pm_event = pm->pm_event; 2846 p->pm_flags = pm->pm_flags; 2847 2848 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 2849 p->pm_reloadcount = 2850 pm->pm_sc.pm_reloadcount; 2851 } 2852 2853 pmc_restore_cpu_binding(&pb); 2854 2855 /* now copy out the PMC info collected */ 2856 if (error == 0) 2857 error = copyout(pmcinfo, &gpi->pm_pmcs, pmcinfo_size); 2858 2859 free(pmcinfo, M_PMC); 2860 } 2861 break; 2862 2863 2864 /* 2865 * Set the administrative state of a PMC. I.e. whether 2866 * the PMC is to be used or not. 2867 */ 2868 2869 case PMC_OP_PMCADMIN: 2870 { 2871 int cpu, ri; 2872 enum pmc_state request; 2873 struct pmc_cpu *pc; 2874 struct pmc_hw *phw; 2875 struct pmc_op_pmcadmin pma; 2876 struct pmc_binding pb; 2877 2878 sx_assert(&pmc_sx, SX_XLOCKED); 2879 2880 KASSERT(td == curthread, 2881 ("[pmc,%d] td != curthread", __LINE__)); 2882 2883 error = priv_check(td, PRIV_PMC_MANAGE); 2884 if (error) 2885 break; 2886 2887 if ((error = copyin(arg, &pma, sizeof(pma))) != 0) 2888 break; 2889 2890 cpu = pma.pm_cpu; 2891 2892 if (cpu < 0 || cpu >= (int) pmc_cpu_max()) { 2893 error = EINVAL; 2894 break; 2895 } 2896 2897 if (!pmc_cpu_is_active(cpu)) { 2898 error = ENXIO; 2899 break; 2900 } 2901 2902 request = pma.pm_state; 2903 2904 if (request != PMC_STATE_DISABLED && 2905 request != PMC_STATE_FREE) { 2906 error = EINVAL; 2907 break; 2908 } 2909 2910 ri = pma.pm_pmc; /* pmc id == row index */ 2911 if (ri < 0 || ri >= (int) md->pmd_npmc) { 2912 error = EINVAL; 2913 break; 2914 } 2915 2916 /* 2917 * We can't disable a PMC with a row-index allocated 2918 * for process virtual PMCs. 2919 */ 2920 2921 if (PMC_ROW_DISP_IS_THREAD(ri) && 2922 request == PMC_STATE_DISABLED) { 2923 error = EBUSY; 2924 break; 2925 } 2926 2927 /* 2928 * otherwise, this PMC on this CPU is either free or 2929 * in system-wide mode. 2930 */ 2931 2932 pmc_save_cpu_binding(&pb); 2933 pmc_select_cpu(cpu); 2934 2935 pc = pmc_pcpu[cpu]; 2936 phw = pc->pc_hwpmcs[ri]; 2937 2938 /* 2939 * XXX do we need some kind of 'forced' disable? 2940 */ 2941 2942 if (phw->phw_pmc == NULL) { 2943 if (request == PMC_STATE_DISABLED && 2944 (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED)) { 2945 phw->phw_state &= ~PMC_PHW_FLAG_IS_ENABLED; 2946 PMC_MARK_ROW_STANDALONE(ri); 2947 } else if (request == PMC_STATE_FREE && 2948 (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0) { 2949 phw->phw_state |= PMC_PHW_FLAG_IS_ENABLED; 2950 PMC_UNMARK_ROW_STANDALONE(ri); 2951 } 2952 /* other cases are a no-op */ 2953 } else 2954 error = EBUSY; 2955 2956 pmc_restore_cpu_binding(&pb); 2957 } 2958 break; 2959 2960 2961 /* 2962 * Allocate a PMC. 2963 */ 2964 2965 case PMC_OP_PMCALLOCATE: 2966 { 2967 uint32_t caps; 2968 u_int cpu; 2969 int n; 2970 enum pmc_mode mode; 2971 struct pmc *pmc; 2972 struct pmc_hw *phw; 2973 struct pmc_op_pmcallocate pa; 2974 struct pmc_binding pb; 2975 2976 if ((error = copyin(arg, &pa, sizeof(pa))) != 0) 2977 break; 2978 2979 caps = pa.pm_caps; 2980 mode = pa.pm_mode; 2981 cpu = pa.pm_cpu; 2982 2983 if ((mode != PMC_MODE_SS && mode != PMC_MODE_SC && 2984 mode != PMC_MODE_TS && mode != PMC_MODE_TC) || 2985 (cpu != (u_int) PMC_CPU_ANY && cpu >= pmc_cpu_max())) { 2986 error = EINVAL; 2987 break; 2988 } 2989 2990 /* 2991 * Virtual PMCs should only ask for a default CPU. 2992 * System mode PMCs need to specify a non-default CPU. 2993 */ 2994 2995 if ((PMC_IS_VIRTUAL_MODE(mode) && cpu != (u_int) PMC_CPU_ANY) || 2996 (PMC_IS_SYSTEM_MODE(mode) && cpu == (u_int) PMC_CPU_ANY)) { 2997 error = EINVAL; 2998 break; 2999 } 3000 3001 /* 3002 * Check that an inactive CPU is not being asked for. 3003 */ 3004 3005 if (PMC_IS_SYSTEM_MODE(mode) && !pmc_cpu_is_active(cpu)) { 3006 error = ENXIO; 3007 break; 3008 } 3009 3010 /* 3011 * Refuse an allocation for a system-wide PMC if this 3012 * process has been jailed, or if this process lacks 3013 * super-user credentials and the sysctl tunable 3014 * 'security.bsd.unprivileged_syspmcs' is zero. 3015 */ 3016 3017 if (PMC_IS_SYSTEM_MODE(mode)) { 3018 if (jailed(curthread->td_ucred)) { 3019 error = EPERM; 3020 break; 3021 } 3022 if (!pmc_unprivileged_syspmcs) { 3023 error = priv_check(curthread, 3024 PRIV_PMC_SYSTEM); 3025 if (error) 3026 break; 3027 } 3028 } 3029 3030 if (error) 3031 break; 3032 3033 /* 3034 * Look for valid values for 'pm_flags' 3035 */ 3036 3037 if ((pa.pm_flags & ~(PMC_F_DESCENDANTS | PMC_F_LOG_PROCCSW | 3038 PMC_F_LOG_PROCEXIT | PMC_F_CALLCHAIN)) != 0) { 3039 error = EINVAL; 3040 break; 3041 } 3042 3043 /* process logging options are not allowed for system PMCs */ 3044 if (PMC_IS_SYSTEM_MODE(mode) && (pa.pm_flags & 3045 (PMC_F_LOG_PROCCSW | PMC_F_LOG_PROCEXIT))) { 3046 error = EINVAL; 3047 break; 3048 } 3049 3050 /* 3051 * All sampling mode PMCs need to be able to interrupt the 3052 * CPU. 3053 */ 3054 if (PMC_IS_SAMPLING_MODE(mode)) 3055 caps |= PMC_CAP_INTERRUPT; 3056 3057 /* A valid class specifier should have been passed in. */ 3058 for (n = 0; n < md->pmd_nclass; n++) 3059 if (md->pmd_classes[n].pm_class == pa.pm_class) 3060 break; 3061 if (n == md->pmd_nclass) { 3062 error = EINVAL; 3063 break; 3064 } 3065 3066 /* The requested PMC capabilities should be feasible. */ 3067 if ((md->pmd_classes[n].pm_caps & caps) != caps) { 3068 error = EOPNOTSUPP; 3069 break; 3070 } 3071 3072 PMCDBG(PMC,ALL,2, "event=%d caps=0x%x mode=%d cpu=%d", 3073 pa.pm_ev, caps, mode, cpu); 3074 3075 pmc = pmc_allocate_pmc_descriptor(); 3076 pmc->pm_id = PMC_ID_MAKE_ID(cpu,pa.pm_mode,pa.pm_class, 3077 PMC_ID_INVALID); 3078 pmc->pm_event = pa.pm_ev; 3079 pmc->pm_state = PMC_STATE_FREE; 3080 pmc->pm_caps = caps; 3081 pmc->pm_flags = pa.pm_flags; 3082 3083 /* switch thread to CPU 'cpu' */ 3084 pmc_save_cpu_binding(&pb); 3085 3086 #define PMC_IS_SHAREABLE_PMC(cpu, n) \ 3087 (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_state & \ 3088 PMC_PHW_FLAG_IS_SHAREABLE) 3089 #define PMC_IS_UNALLOCATED(cpu, n) \ 3090 (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_pmc == NULL) 3091 3092 if (PMC_IS_SYSTEM_MODE(mode)) { 3093 pmc_select_cpu(cpu); 3094 for (n = 0; n < (int) md->pmd_npmc; n++) 3095 if (pmc_can_allocate_row(n, mode) == 0 && 3096 pmc_can_allocate_rowindex( 3097 curthread->td_proc, n, cpu) == 0 && 3098 (PMC_IS_UNALLOCATED(cpu, n) || 3099 PMC_IS_SHAREABLE_PMC(cpu, n)) && 3100 md->pmd_allocate_pmc(cpu, n, pmc, 3101 &pa) == 0) 3102 break; 3103 } else { 3104 /* Process virtual mode */ 3105 for (n = 0; n < (int) md->pmd_npmc; n++) { 3106 if (pmc_can_allocate_row(n, mode) == 0 && 3107 pmc_can_allocate_rowindex( 3108 curthread->td_proc, n, 3109 PMC_CPU_ANY) == 0 && 3110 md->pmd_allocate_pmc(curthread->td_oncpu, 3111 n, pmc, &pa) == 0) 3112 break; 3113 } 3114 } 3115 3116 #undef PMC_IS_UNALLOCATED 3117 #undef PMC_IS_SHAREABLE_PMC 3118 3119 pmc_restore_cpu_binding(&pb); 3120 3121 if (n == (int) md->pmd_npmc) { 3122 pmc_destroy_pmc_descriptor(pmc); 3123 free(pmc, M_PMC); 3124 pmc = NULL; 3125 error = EINVAL; 3126 break; 3127 } 3128 3129 /* Fill in the correct value in the ID field */ 3130 pmc->pm_id = PMC_ID_MAKE_ID(cpu,mode,pa.pm_class,n); 3131 3132 PMCDBG(PMC,ALL,2, "ev=%d class=%d mode=%d n=%d -> pmcid=%x", 3133 pmc->pm_event, pa.pm_class, mode, n, pmc->pm_id); 3134 3135 /* Process mode PMCs with logging enabled need log files */ 3136 if (pmc->pm_flags & (PMC_F_LOG_PROCEXIT | PMC_F_LOG_PROCCSW)) 3137 pmc->pm_flags |= PMC_F_NEEDS_LOGFILE; 3138 3139 /* All system mode sampling PMCs require a log file */ 3140 if (PMC_IS_SAMPLING_MODE(mode) && PMC_IS_SYSTEM_MODE(mode)) 3141 pmc->pm_flags |= PMC_F_NEEDS_LOGFILE; 3142 3143 /* 3144 * Configure global pmc's immediately 3145 */ 3146 3147 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pmc))) { 3148 3149 pmc_save_cpu_binding(&pb); 3150 pmc_select_cpu(cpu); 3151 3152 phw = pmc_pcpu[cpu]->pc_hwpmcs[n]; 3153 3154 if ((phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0 || 3155 (error = md->pmd_config_pmc(cpu, n, pmc)) != 0) { 3156 (void) md->pmd_release_pmc(cpu, n, pmc); 3157 pmc_destroy_pmc_descriptor(pmc); 3158 free(pmc, M_PMC); 3159 pmc = NULL; 3160 pmc_restore_cpu_binding(&pb); 3161 error = EPERM; 3162 break; 3163 } 3164 3165 pmc_restore_cpu_binding(&pb); 3166 } 3167 3168 pmc->pm_state = PMC_STATE_ALLOCATED; 3169 3170 /* 3171 * mark row disposition 3172 */ 3173 3174 if (PMC_IS_SYSTEM_MODE(mode)) 3175 PMC_MARK_ROW_STANDALONE(n); 3176 else 3177 PMC_MARK_ROW_THREAD(n); 3178 3179 /* 3180 * Register this PMC with the current thread as its owner. 3181 */ 3182 3183 if ((error = 3184 pmc_register_owner(curthread->td_proc, pmc)) != 0) { 3185 pmc_release_pmc_descriptor(pmc); 3186 free(pmc, M_PMC); 3187 pmc = NULL; 3188 break; 3189 } 3190 3191 /* 3192 * Return the allocated index. 3193 */ 3194 3195 pa.pm_pmcid = pmc->pm_id; 3196 3197 error = copyout(&pa, arg, sizeof(pa)); 3198 } 3199 break; 3200 3201 3202 /* 3203 * Attach a PMC to a process. 3204 */ 3205 3206 case PMC_OP_PMCATTACH: 3207 { 3208 struct pmc *pm; 3209 struct proc *p; 3210 struct pmc_op_pmcattach a; 3211 3212 sx_assert(&pmc_sx, SX_XLOCKED); 3213 3214 if ((error = copyin(arg, &a, sizeof(a))) != 0) 3215 break; 3216 3217 if (a.pm_pid < 0) { 3218 error = EINVAL; 3219 break; 3220 } else if (a.pm_pid == 0) 3221 a.pm_pid = td->td_proc->p_pid; 3222 3223 if ((error = pmc_find_pmc(a.pm_pmc, &pm)) != 0) 3224 break; 3225 3226 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) { 3227 error = EINVAL; 3228 break; 3229 } 3230 3231 /* PMCs may be (re)attached only when allocated or stopped */ 3232 if (pm->pm_state == PMC_STATE_RUNNING) { 3233 error = EBUSY; 3234 break; 3235 } else if (pm->pm_state != PMC_STATE_ALLOCATED && 3236 pm->pm_state != PMC_STATE_STOPPED) { 3237 error = EINVAL; 3238 break; 3239 } 3240 3241 /* lookup pid */ 3242 if ((p = pfind(a.pm_pid)) == NULL) { 3243 error = ESRCH; 3244 break; 3245 } 3246 3247 /* 3248 * Ignore processes that are working on exiting. 3249 */ 3250 if (p->p_flag & P_WEXIT) { 3251 error = ESRCH; 3252 PROC_UNLOCK(p); /* pfind() returns a locked process */ 3253 break; 3254 } 3255 3256 /* 3257 * we are allowed to attach a PMC to a process if 3258 * we can debug it. 3259 */ 3260 error = p_candebug(curthread, p); 3261 3262 PROC_UNLOCK(p); 3263 3264 if (error == 0) 3265 error = pmc_attach_process(p, pm); 3266 } 3267 break; 3268 3269 3270 /* 3271 * Detach an attached PMC from a process. 3272 */ 3273 3274 case PMC_OP_PMCDETACH: 3275 { 3276 struct pmc *pm; 3277 struct proc *p; 3278 struct pmc_op_pmcattach a; 3279 3280 if ((error = copyin(arg, &a, sizeof(a))) != 0) 3281 break; 3282 3283 if (a.pm_pid < 0) { 3284 error = EINVAL; 3285 break; 3286 } else if (a.pm_pid == 0) 3287 a.pm_pid = td->td_proc->p_pid; 3288 3289 if ((error = pmc_find_pmc(a.pm_pmc, &pm)) != 0) 3290 break; 3291 3292 if ((p = pfind(a.pm_pid)) == NULL) { 3293 error = ESRCH; 3294 break; 3295 } 3296 3297 /* 3298 * Treat processes that are in the process of exiting 3299 * as if they were not present. 3300 */ 3301 3302 if (p->p_flag & P_WEXIT) 3303 error = ESRCH; 3304 3305 PROC_UNLOCK(p); /* pfind() returns a locked process */ 3306 3307 if (error == 0) 3308 error = pmc_detach_process(p, pm); 3309 } 3310 break; 3311 3312 3313 /* 3314 * Retrieve the MSR number associated with the counter 3315 * 'pmc_id'. This allows processes to directly use RDPMC 3316 * instructions to read their PMCs, without the overhead of a 3317 * system call. 3318 */ 3319 3320 case PMC_OP_PMCGETMSR: 3321 { 3322 int ri; 3323 struct pmc *pm; 3324 struct pmc_target *pt; 3325 struct pmc_op_getmsr gm; 3326 3327 PMC_DOWNGRADE_SX(); 3328 3329 /* CPU has no 'GETMSR' support */ 3330 if (md->pmd_get_msr == NULL) { 3331 error = ENOSYS; 3332 break; 3333 } 3334 3335 if ((error = copyin(arg, &gm, sizeof(gm))) != 0) 3336 break; 3337 3338 if ((error = pmc_find_pmc(gm.pm_pmcid, &pm)) != 0) 3339 break; 3340 3341 /* 3342 * The allocated PMC has to be a process virtual PMC, 3343 * i.e., of type MODE_T[CS]. Global PMCs can only be 3344 * read using the PMCREAD operation since they may be 3345 * allocated on a different CPU than the one we could 3346 * be running on at the time of the RDPMC instruction. 3347 * 3348 * The GETMSR operation is not allowed for PMCs that 3349 * are inherited across processes. 3350 */ 3351 3352 if (!PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)) || 3353 (pm->pm_flags & PMC_F_DESCENDANTS)) { 3354 error = EINVAL; 3355 break; 3356 } 3357 3358 /* 3359 * It only makes sense to use a RDPMC (or its 3360 * equivalent instruction on non-x86 architectures) on 3361 * a process that has allocated and attached a PMC to 3362 * itself. Conversely the PMC is only allowed to have 3363 * one process attached to it -- its owner. 3364 */ 3365 3366 if ((pt = LIST_FIRST(&pm->pm_targets)) == NULL || 3367 LIST_NEXT(pt, pt_next) != NULL || 3368 pt->pt_process->pp_proc != pm->pm_owner->po_owner) { 3369 error = EINVAL; 3370 break; 3371 } 3372 3373 ri = PMC_TO_ROWINDEX(pm); 3374 3375 if ((error = (*md->pmd_get_msr)(ri, &gm.pm_msr)) < 0) 3376 break; 3377 3378 if ((error = copyout(&gm, arg, sizeof(gm))) < 0) 3379 break; 3380 3381 /* 3382 * Mark our process as using MSRs. Update machine 3383 * state using a forced context switch. 3384 */ 3385 3386 pt->pt_process->pp_flags |= PMC_PP_ENABLE_MSR_ACCESS; 3387 pmc_force_context_switch(); 3388 3389 } 3390 break; 3391 3392 /* 3393 * Release an allocated PMC 3394 */ 3395 3396 case PMC_OP_PMCRELEASE: 3397 { 3398 pmc_id_t pmcid; 3399 struct pmc *pm; 3400 struct pmc_owner *po; 3401 struct pmc_op_simple sp; 3402 3403 /* 3404 * Find PMC pointer for the named PMC. 3405 * 3406 * Use pmc_release_pmc_descriptor() to switch off the 3407 * PMC, remove all its target threads, and remove the 3408 * PMC from its owner's list. 3409 * 3410 * Remove the owner record if this is the last PMC 3411 * owned. 3412 * 3413 * Free up space. 3414 */ 3415 3416 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 3417 break; 3418 3419 pmcid = sp.pm_pmcid; 3420 3421 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 3422 break; 3423 3424 po = pm->pm_owner; 3425 pmc_release_pmc_descriptor(pm); 3426 pmc_maybe_remove_owner(po); 3427 3428 free(pm, M_PMC); 3429 } 3430 break; 3431 3432 3433 /* 3434 * Read and/or write a PMC. 3435 */ 3436 3437 case PMC_OP_PMCRW: 3438 { 3439 uint32_t cpu, ri; 3440 struct pmc *pm; 3441 struct pmc_op_pmcrw *pprw; 3442 struct pmc_op_pmcrw prw; 3443 struct pmc_binding pb; 3444 pmc_value_t oldvalue; 3445 3446 PMC_DOWNGRADE_SX(); 3447 3448 if ((error = copyin(arg, &prw, sizeof(prw))) != 0) 3449 break; 3450 3451 ri = 0; 3452 PMCDBG(PMC,OPS,1, "rw id=%d flags=0x%x", prw.pm_pmcid, 3453 prw.pm_flags); 3454 3455 /* must have at least one flag set */ 3456 if ((prw.pm_flags & (PMC_F_OLDVALUE|PMC_F_NEWVALUE)) == 0) { 3457 error = EINVAL; 3458 break; 3459 } 3460 3461 /* locate pmc descriptor */ 3462 if ((error = pmc_find_pmc(prw.pm_pmcid, &pm)) != 0) 3463 break; 3464 3465 /* Can't read a PMC that hasn't been started. */ 3466 if (pm->pm_state != PMC_STATE_ALLOCATED && 3467 pm->pm_state != PMC_STATE_STOPPED && 3468 pm->pm_state != PMC_STATE_RUNNING) { 3469 error = EINVAL; 3470 break; 3471 } 3472 3473 /* writing a new value is allowed only for 'STOPPED' pmcs */ 3474 if (pm->pm_state == PMC_STATE_RUNNING && 3475 (prw.pm_flags & PMC_F_NEWVALUE)) { 3476 error = EBUSY; 3477 break; 3478 } 3479 3480 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) { 3481 3482 /* 3483 * If this PMC is attached to its owner (i.e., 3484 * the process requesting this operation) and 3485 * is running, then attempt to get an 3486 * upto-date reading from hardware for a READ. 3487 * Writes are only allowed when the PMC is 3488 * stopped, so only update the saved value 3489 * field. 3490 * 3491 * If the PMC is not running, or is not 3492 * attached to its owner, read/write to the 3493 * savedvalue field. 3494 */ 3495 3496 ri = PMC_TO_ROWINDEX(pm); 3497 3498 mtx_pool_lock_spin(pmc_mtxpool, pm); 3499 cpu = curthread->td_oncpu; 3500 3501 if (prw.pm_flags & PMC_F_OLDVALUE) { 3502 if ((pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) && 3503 (pm->pm_state == PMC_STATE_RUNNING)) 3504 error = (*md->pmd_read_pmc)(cpu, ri, 3505 &oldvalue); 3506 else 3507 oldvalue = pm->pm_gv.pm_savedvalue; 3508 } 3509 if (prw.pm_flags & PMC_F_NEWVALUE) 3510 pm->pm_gv.pm_savedvalue = prw.pm_value; 3511 3512 mtx_pool_unlock_spin(pmc_mtxpool, pm); 3513 3514 } else { /* System mode PMCs */ 3515 cpu = PMC_TO_CPU(pm); 3516 ri = PMC_TO_ROWINDEX(pm); 3517 3518 if (!pmc_cpu_is_active(cpu)) { 3519 error = ENXIO; 3520 break; 3521 } 3522 3523 /* move this thread to CPU 'cpu' */ 3524 pmc_save_cpu_binding(&pb); 3525 pmc_select_cpu(cpu); 3526 3527 critical_enter(); 3528 /* save old value */ 3529 if (prw.pm_flags & PMC_F_OLDVALUE) 3530 if ((error = (*md->pmd_read_pmc)(cpu, ri, 3531 &oldvalue))) 3532 goto error; 3533 /* write out new value */ 3534 if (prw.pm_flags & PMC_F_NEWVALUE) 3535 error = (*md->pmd_write_pmc)(cpu, ri, 3536 prw.pm_value); 3537 error: 3538 critical_exit(); 3539 pmc_restore_cpu_binding(&pb); 3540 if (error) 3541 break; 3542 } 3543 3544 pprw = (struct pmc_op_pmcrw *) arg; 3545 3546 #ifdef DEBUG 3547 if (prw.pm_flags & PMC_F_NEWVALUE) 3548 PMCDBG(PMC,OPS,2, "rw id=%d new %jx -> old %jx", 3549 ri, prw.pm_value, oldvalue); 3550 else if (prw.pm_flags & PMC_F_OLDVALUE) 3551 PMCDBG(PMC,OPS,2, "rw id=%d -> old %jx", ri, oldvalue); 3552 #endif 3553 3554 /* return old value if requested */ 3555 if (prw.pm_flags & PMC_F_OLDVALUE) 3556 if ((error = copyout(&oldvalue, &pprw->pm_value, 3557 sizeof(prw.pm_value)))) 3558 break; 3559 3560 } 3561 break; 3562 3563 3564 /* 3565 * Set the sampling rate for a sampling mode PMC and the 3566 * initial count for a counting mode PMC. 3567 */ 3568 3569 case PMC_OP_PMCSETCOUNT: 3570 { 3571 struct pmc *pm; 3572 struct pmc_op_pmcsetcount sc; 3573 3574 PMC_DOWNGRADE_SX(); 3575 3576 if ((error = copyin(arg, &sc, sizeof(sc))) != 0) 3577 break; 3578 3579 if ((error = pmc_find_pmc(sc.pm_pmcid, &pm)) != 0) 3580 break; 3581 3582 if (pm->pm_state == PMC_STATE_RUNNING) { 3583 error = EBUSY; 3584 break; 3585 } 3586 3587 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 3588 pm->pm_sc.pm_reloadcount = sc.pm_count; 3589 else 3590 pm->pm_sc.pm_initial = sc.pm_count; 3591 } 3592 break; 3593 3594 3595 /* 3596 * Start a PMC. 3597 */ 3598 3599 case PMC_OP_PMCSTART: 3600 { 3601 pmc_id_t pmcid; 3602 struct pmc *pm; 3603 struct pmc_op_simple sp; 3604 3605 sx_assert(&pmc_sx, SX_XLOCKED); 3606 3607 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 3608 break; 3609 3610 pmcid = sp.pm_pmcid; 3611 3612 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 3613 break; 3614 3615 KASSERT(pmcid == pm->pm_id, 3616 ("[pmc,%d] pmcid %x != id %x", __LINE__, 3617 pm->pm_id, pmcid)); 3618 3619 if (pm->pm_state == PMC_STATE_RUNNING) /* already running */ 3620 break; 3621 else if (pm->pm_state != PMC_STATE_STOPPED && 3622 pm->pm_state != PMC_STATE_ALLOCATED) { 3623 error = EINVAL; 3624 break; 3625 } 3626 3627 error = pmc_start(pm); 3628 } 3629 break; 3630 3631 3632 /* 3633 * Stop a PMC. 3634 */ 3635 3636 case PMC_OP_PMCSTOP: 3637 { 3638 pmc_id_t pmcid; 3639 struct pmc *pm; 3640 struct pmc_op_simple sp; 3641 3642 PMC_DOWNGRADE_SX(); 3643 3644 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 3645 break; 3646 3647 pmcid = sp.pm_pmcid; 3648 3649 /* 3650 * Mark the PMC as inactive and invoke the MD stop 3651 * routines if needed. 3652 */ 3653 3654 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 3655 break; 3656 3657 KASSERT(pmcid == pm->pm_id, 3658 ("[pmc,%d] pmc id %x != pmcid %x", __LINE__, 3659 pm->pm_id, pmcid)); 3660 3661 if (pm->pm_state == PMC_STATE_STOPPED) /* already stopped */ 3662 break; 3663 else if (pm->pm_state != PMC_STATE_RUNNING) { 3664 error = EINVAL; 3665 break; 3666 } 3667 3668 error = pmc_stop(pm); 3669 } 3670 break; 3671 3672 3673 /* 3674 * Write a user supplied value to the log file. 3675 */ 3676 3677 case PMC_OP_WRITELOG: 3678 { 3679 struct pmc_op_writelog wl; 3680 struct pmc_owner *po; 3681 3682 PMC_DOWNGRADE_SX(); 3683 3684 if ((error = copyin(arg, &wl, sizeof(wl))) != 0) 3685 break; 3686 3687 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 3688 error = EINVAL; 3689 break; 3690 } 3691 3692 if ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) { 3693 error = EINVAL; 3694 break; 3695 } 3696 3697 error = pmclog_process_userlog(po, &wl); 3698 } 3699 break; 3700 3701 3702 default: 3703 error = EINVAL; 3704 break; 3705 } 3706 3707 if (is_sx_downgraded) 3708 sx_sunlock(&pmc_sx); 3709 else 3710 sx_xunlock(&pmc_sx); 3711 3712 if (error) 3713 atomic_add_int(&pmc_stats.pm_syscall_errors, 1); 3714 3715 PICKUP_GIANT(); 3716 3717 return error; 3718 } 3719 3720 /* 3721 * Helper functions 3722 */ 3723 3724 3725 /* 3726 * Mark the thread as needing callchain capture and post an AST. The 3727 * actual callchain capture will be done in a context where it is safe 3728 * to take page faults. 3729 */ 3730 3731 static void 3732 pmc_post_callchain_ast(void) 3733 { 3734 struct thread *td; 3735 3736 td = curthread; 3737 3738 /* 3739 * Mark this thread as needing processing in ast(). 3740 * td->td_pflags will be safe to touch as the process was in 3741 * user space when it was interrupted. 3742 */ 3743 td->td_pflags |= TDP_CALLCHAIN; 3744 3745 /* 3746 * Again, since we've entered this function directly from 3747 * userland, `td' is guaranteed to be not locked by this CPU, 3748 * so its safe to try acquire the thread lock even though we 3749 * are executing in an NMI context. We need to acquire this 3750 * lock before touching `td_flags' because other CPUs may be 3751 * in the process of touching this field. 3752 */ 3753 thread_lock(td); 3754 td->td_flags |= TDF_ASTPENDING; 3755 thread_unlock(td); 3756 3757 return; 3758 } 3759 3760 /* 3761 * Interrupt processing. 3762 * 3763 * Find a free slot in the per-cpu array of samples and capture the 3764 * current callchain there. If a sample was successfully added, a bit 3765 * is set in mask 'pmc_cpumask' denoting that the DO_SAMPLES hook 3766 * needs to be invoked from the clock handler. 3767 * 3768 * This function is meant to be called from an NMI handler. It cannot 3769 * use any of the locking primitives supplied by the OS. 3770 */ 3771 3772 int 3773 pmc_process_interrupt(int cpu, struct pmc *pm, struct trapframe *tf, 3774 int inuserspace) 3775 { 3776 int error, callchaindepth; 3777 struct thread *td; 3778 struct pmc_sample *ps; 3779 struct pmc_samplebuffer *psb; 3780 3781 error = 0; 3782 3783 /* 3784 * Allocate space for a sample buffer. 3785 */ 3786 psb = pmc_pcpu[cpu]->pc_sb; 3787 3788 ps = psb->ps_write; 3789 if (ps->ps_nsamples) { /* in use, reader hasn't caught up */ 3790 pm->pm_stalled = 1; 3791 atomic_add_int(&pmc_stats.pm_intr_bufferfull, 1); 3792 PMCDBG(SAM,INT,1,"(spc) cpu=%d pm=%p tf=%p um=%d wr=%d rd=%d", 3793 cpu, pm, (void *) tf, inuserspace, 3794 (int) (psb->ps_write - psb->ps_samples), 3795 (int) (psb->ps_read - psb->ps_samples)); 3796 error = ENOMEM; 3797 goto done; 3798 } 3799 3800 3801 /* Fill in entry. */ 3802 PMCDBG(SAM,INT,1,"cpu=%d pm=%p tf=%p um=%d wr=%d rd=%d", cpu, pm, 3803 (void *) tf, inuserspace, 3804 (int) (psb->ps_write - psb->ps_samples), 3805 (int) (psb->ps_read - psb->ps_samples)); 3806 3807 atomic_add_rel_32(&pm->pm_runcount, 1); /* hold onto PMC */ 3808 ps->ps_pmc = pm; 3809 if ((td = curthread) && td->td_proc) 3810 ps->ps_pid = td->td_proc->p_pid; 3811 else 3812 ps->ps_pid = -1; 3813 ps->ps_cpu = cpu; 3814 ps->ps_flags = inuserspace ? PMC_CC_F_USERSPACE : 0; 3815 3816 callchaindepth = (pm->pm_flags & PMC_F_CALLCHAIN) ? 3817 pmc_callchaindepth : 1; 3818 3819 if (callchaindepth == 1) 3820 ps->ps_pc[0] = PMC_TRAPFRAME_TO_PC(tf); 3821 else { 3822 /* 3823 * Kernel stack traversals can be done immediately, 3824 * while we defer to an AST for user space traversals. 3825 */ 3826 if (!inuserspace) 3827 callchaindepth = 3828 pmc_save_kernel_callchain(ps->ps_pc, 3829 callchaindepth, tf); 3830 else { 3831 pmc_post_callchain_ast(); 3832 callchaindepth = PMC_SAMPLE_INUSE; 3833 } 3834 } 3835 3836 ps->ps_nsamples = callchaindepth; /* mark entry as in use */ 3837 3838 /* increment write pointer, modulo ring buffer size */ 3839 ps++; 3840 if (ps == psb->ps_fence) 3841 psb->ps_write = psb->ps_samples; 3842 else 3843 psb->ps_write = ps; 3844 3845 done: 3846 /* mark CPU as needing processing */ 3847 atomic_set_rel_int(&pmc_cpumask, (1 << cpu)); 3848 3849 return (error); 3850 } 3851 3852 /* 3853 * Capture a user call chain. This function will be called from ast() 3854 * before control returns to userland and before the process gets 3855 * rescheduled. 3856 */ 3857 3858 static void 3859 pmc_capture_user_callchain(int cpu, struct trapframe *tf) 3860 { 3861 int i; 3862 struct pmc *pm; 3863 struct pmc_sample *ps; 3864 struct pmc_samplebuffer *psb; 3865 3866 psb = pmc_pcpu[cpu]->pc_sb; 3867 3868 /* 3869 * Iterate through all deferred callchain requests. 3870 */ 3871 3872 for (i = 0; i < pmc_nsamples; i++) { 3873 3874 ps = &psb->ps_samples[i]; 3875 if (ps->ps_nsamples != PMC_SAMPLE_INUSE) 3876 continue; 3877 3878 pm = ps->ps_pmc; 3879 3880 KASSERT(pm->pm_flags & PMC_F_CALLCHAIN, 3881 ("[pmc,%d] Retrieving callchain for PMC that doesn't " 3882 "want it", __LINE__)); 3883 3884 /* 3885 * Retrieve the callchain and mark the sample buffer 3886 * as 'processable' by the timer tick sweep code. 3887 */ 3888 ps->ps_nsamples = pmc_save_user_callchain(ps->ps_pc, 3889 pmc_callchaindepth, tf); 3890 } 3891 3892 return; 3893 } 3894 3895 3896 /* 3897 * Process saved PC samples. 3898 */ 3899 3900 static void 3901 pmc_process_samples(int cpu) 3902 { 3903 int n, ri; 3904 struct pmc *pm; 3905 struct thread *td; 3906 struct pmc_owner *po; 3907 struct pmc_sample *ps; 3908 struct pmc_samplebuffer *psb; 3909 3910 KASSERT(PCPU_GET(cpuid) == cpu, 3911 ("[pmc,%d] not on the correct CPU pcpu=%d cpu=%d", __LINE__, 3912 PCPU_GET(cpuid), cpu)); 3913 3914 psb = pmc_pcpu[cpu]->pc_sb; 3915 3916 for (n = 0; n < pmc_nsamples; n++) { /* bound on #iterations */ 3917 3918 ps = psb->ps_read; 3919 if (ps->ps_nsamples == PMC_SAMPLE_FREE) 3920 break; 3921 if (ps->ps_nsamples == PMC_SAMPLE_INUSE) { 3922 /* Need a rescan at a later time. */ 3923 atomic_set_rel_int(&pmc_cpumask, (1 << cpu)); 3924 break; 3925 } 3926 3927 pm = ps->ps_pmc; 3928 po = pm->pm_owner; 3929 3930 KASSERT(PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)), 3931 ("[pmc,%d] pmc=%p non-sampling mode=%d", __LINE__, 3932 pm, PMC_TO_MODE(pm))); 3933 3934 /* Ignore PMCs that have been switched off */ 3935 if (pm->pm_state != PMC_STATE_RUNNING) 3936 goto entrydone; 3937 3938 PMCDBG(SAM,OPS,1,"cpu=%d pm=%p n=%d fl=%x wr=%d rd=%d", cpu, 3939 pm, ps->ps_nsamples, ps->ps_flags, 3940 (int) (psb->ps_write - psb->ps_samples), 3941 (int) (psb->ps_read - psb->ps_samples)); 3942 3943 /* 3944 * If this is a process-mode PMC that is attached to 3945 * its owner, and if the PC is in user mode, update 3946 * profiling statistics like timer-based profiling 3947 * would have done. 3948 */ 3949 if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) { 3950 if (ps->ps_flags & PMC_CC_F_USERSPACE) { 3951 td = FIRST_THREAD_IN_PROC(po->po_owner); 3952 addupc_intr(td, ps->ps_pc[0], 1); 3953 } 3954 goto entrydone; 3955 } 3956 3957 /* 3958 * Otherwise, this is either a sampling mode PMC that 3959 * is attached to a different process than its owner, 3960 * or a system-wide sampling PMC. Dispatch a log 3961 * entry to the PMC's owner process. 3962 */ 3963 3964 pmclog_process_callchain(pm, ps); 3965 3966 entrydone: 3967 ps->ps_nsamples = 0; /* mark entry as free */ 3968 atomic_subtract_rel_32(&pm->pm_runcount, 1); 3969 3970 /* increment read pointer, modulo sample size */ 3971 if (++ps == psb->ps_fence) 3972 psb->ps_read = psb->ps_samples; 3973 else 3974 psb->ps_read = ps; 3975 } 3976 3977 atomic_add_int(&pmc_stats.pm_log_sweeps, 1); 3978 3979 /* Do not re-enable stalled PMCs if we failed to process any samples */ 3980 if (n == 0) 3981 return; 3982 3983 /* 3984 * Restart any stalled sampling PMCs on this CPU. 3985 * 3986 * If the NMI handler sets the pm_stalled field of a PMC after 3987 * the check below, we'll end up processing the stalled PMC at 3988 * the next hardclock tick. 3989 */ 3990 for (n = 0; n < md->pmd_npmc; n++) { 3991 (void) (*md->pmd_get_config)(cpu,n,&pm); 3992 if (pm == NULL || /* !cfg'ed */ 3993 pm->pm_state != PMC_STATE_RUNNING || /* !active */ 3994 !PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)) || /* !sampling */ 3995 pm->pm_stalled == 0) /* !stalled */ 3996 continue; 3997 3998 pm->pm_stalled = 0; 3999 ri = PMC_TO_ROWINDEX(pm); 4000 (*md->pmd_start_pmc)(cpu, ri); 4001 } 4002 } 4003 4004 /* 4005 * Event handlers. 4006 */ 4007 4008 /* 4009 * Handle a process exit. 4010 * 4011 * Remove this process from all hash tables. If this process 4012 * owned any PMCs, turn off those PMCs and deallocate them, 4013 * removing any associations with target processes. 4014 * 4015 * This function will be called by the last 'thread' of a 4016 * process. 4017 * 4018 * XXX This eventhandler gets called early in the exit process. 4019 * Consider using a 'hook' invocation from thread_exit() or equivalent 4020 * spot. Another negative is that kse_exit doesn't seem to call 4021 * exit1() [??]. 4022 * 4023 */ 4024 4025 static void 4026 pmc_process_exit(void *arg __unused, struct proc *p) 4027 { 4028 int is_using_hwpmcs; 4029 int cpu; 4030 unsigned int ri; 4031 struct pmc *pm; 4032 struct pmc_process *pp; 4033 struct pmc_owner *po; 4034 pmc_value_t newvalue, tmp; 4035 4036 PROC_LOCK(p); 4037 is_using_hwpmcs = p->p_flag & P_HWPMC; 4038 PROC_UNLOCK(p); 4039 4040 /* 4041 * Log a sysexit event to all SS PMC owners. 4042 */ 4043 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 4044 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 4045 pmclog_process_sysexit(po, p->p_pid); 4046 4047 if (!is_using_hwpmcs) 4048 return; 4049 4050 PMC_GET_SX_XLOCK(); 4051 PMCDBG(PRC,EXT,1,"process-exit proc=%p (%d, %s)", p, p->p_pid, 4052 p->p_comm); 4053 4054 /* 4055 * Since this code is invoked by the last thread in an exiting 4056 * process, we would have context switched IN at some prior 4057 * point. However, with PREEMPTION, kernel mode context 4058 * switches may happen any time, so we want to disable a 4059 * context switch OUT till we get any PMCs targetting this 4060 * process off the hardware. 4061 * 4062 * We also need to atomically remove this process' 4063 * entry from our target process hash table, using 4064 * PMC_FLAG_REMOVE. 4065 */ 4066 PMCDBG(PRC,EXT,1, "process-exit proc=%p (%d, %s)", p, p->p_pid, 4067 p->p_comm); 4068 4069 critical_enter(); /* no preemption */ 4070 4071 cpu = curthread->td_oncpu; 4072 4073 if ((pp = pmc_find_process_descriptor(p, 4074 PMC_FLAG_REMOVE)) != NULL) { 4075 4076 PMCDBG(PRC,EXT,2, 4077 "process-exit proc=%p pmc-process=%p", p, pp); 4078 4079 /* 4080 * The exiting process could the target of 4081 * some PMCs which will be running on 4082 * currently executing CPU. 4083 * 4084 * We need to turn these PMCs off like we 4085 * would do at context switch OUT time. 4086 */ 4087 for (ri = 0; ri < md->pmd_npmc; ri++) { 4088 4089 /* 4090 * Pick up the pmc pointer from hardware 4091 * state similar to the CSW_OUT code. 4092 */ 4093 pm = NULL; 4094 (void) (*md->pmd_get_config)(cpu, ri, &pm); 4095 4096 PMCDBG(PRC,EXT,2, "ri=%d pm=%p", ri, pm); 4097 4098 if (pm == NULL || 4099 !PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) 4100 continue; 4101 4102 PMCDBG(PRC,EXT,2, "ppmcs[%d]=%p pm=%p " 4103 "state=%d", ri, pp->pp_pmcs[ri].pp_pmc, 4104 pm, pm->pm_state); 4105 4106 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 4107 ("[pmc,%d] ri mismatch pmc(%d) ri(%d)", 4108 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 4109 4110 KASSERT(pm == pp->pp_pmcs[ri].pp_pmc, 4111 ("[pmc,%d] pm %p != pp_pmcs[%d] %p", 4112 __LINE__, pm, ri, pp->pp_pmcs[ri].pp_pmc)); 4113 4114 (void) md->pmd_stop_pmc(cpu, ri); 4115 4116 KASSERT(pm->pm_runcount > 0, 4117 ("[pmc,%d] bad runcount ri %d rc %d", 4118 __LINE__, ri, pm->pm_runcount)); 4119 4120 /* Stop hardware only if it is actually running */ 4121 if (pm->pm_state == PMC_STATE_RUNNING && 4122 pm->pm_stalled == 0) { 4123 md->pmd_read_pmc(cpu, ri, &newvalue); 4124 tmp = newvalue - 4125 PMC_PCPU_SAVED(cpu,ri); 4126 4127 mtx_pool_lock_spin(pmc_mtxpool, pm); 4128 pm->pm_gv.pm_savedvalue += tmp; 4129 pp->pp_pmcs[ri].pp_pmcval += tmp; 4130 mtx_pool_unlock_spin(pmc_mtxpool, pm); 4131 } 4132 4133 atomic_subtract_rel_32(&pm->pm_runcount,1); 4134 4135 KASSERT((int) pm->pm_runcount >= 0, 4136 ("[pmc,%d] runcount is %d", __LINE__, ri)); 4137 4138 (void) md->pmd_config_pmc(cpu, ri, NULL); 4139 } 4140 4141 /* 4142 * Inform the MD layer of this pseudo "context switch 4143 * out" 4144 */ 4145 (void) md->pmd_switch_out(pmc_pcpu[cpu], pp); 4146 4147 critical_exit(); /* ok to be pre-empted now */ 4148 4149 /* 4150 * Unlink this process from the PMCs that are 4151 * targetting it. This will send a signal to 4152 * all PMC owner's whose PMCs are orphaned. 4153 * 4154 * Log PMC value at exit time if requested. 4155 */ 4156 for (ri = 0; ri < md->pmd_npmc; ri++) 4157 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) { 4158 if (pm->pm_flags & PMC_F_NEEDS_LOGFILE && 4159 PMC_IS_COUNTING_MODE(PMC_TO_MODE(pm))) 4160 pmclog_process_procexit(pm, pp); 4161 pmc_unlink_target_process(pm, pp); 4162 } 4163 free(pp, M_PMC); 4164 4165 } else 4166 critical_exit(); /* pp == NULL */ 4167 4168 4169 /* 4170 * If the process owned PMCs, free them up and free up 4171 * memory. 4172 */ 4173 if ((po = pmc_find_owner_descriptor(p)) != NULL) { 4174 pmc_remove_owner(po); 4175 pmc_destroy_owner_descriptor(po); 4176 } 4177 4178 sx_xunlock(&pmc_sx); 4179 } 4180 4181 /* 4182 * Handle a process fork. 4183 * 4184 * If the parent process 'p1' is under HWPMC monitoring, then copy 4185 * over any attached PMCs that have 'do_descendants' semantics. 4186 */ 4187 4188 static void 4189 pmc_process_fork(void *arg __unused, struct proc *p1, struct proc *newproc, 4190 int flags) 4191 { 4192 int is_using_hwpmcs; 4193 unsigned int ri; 4194 uint32_t do_descendants; 4195 struct pmc *pm; 4196 struct pmc_owner *po; 4197 struct pmc_process *ppnew, *ppold; 4198 4199 (void) flags; /* unused parameter */ 4200 4201 PROC_LOCK(p1); 4202 is_using_hwpmcs = p1->p_flag & P_HWPMC; 4203 PROC_UNLOCK(p1); 4204 4205 /* 4206 * If there are system-wide sampling PMCs active, we need to 4207 * log all fork events to their owner's logs. 4208 */ 4209 4210 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 4211 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 4212 pmclog_process_procfork(po, p1->p_pid, newproc->p_pid); 4213 4214 if (!is_using_hwpmcs) 4215 return; 4216 4217 PMC_GET_SX_XLOCK(); 4218 PMCDBG(PMC,FRK,1, "process-fork proc=%p (%d, %s) -> %p", p1, 4219 p1->p_pid, p1->p_comm, newproc); 4220 4221 /* 4222 * If the parent process (curthread->td_proc) is a 4223 * target of any PMCs, look for PMCs that are to be 4224 * inherited, and link these into the new process 4225 * descriptor. 4226 */ 4227 if ((ppold = pmc_find_process_descriptor(curthread->td_proc, 4228 PMC_FLAG_NONE)) == NULL) 4229 goto done; /* nothing to do */ 4230 4231 do_descendants = 0; 4232 for (ri = 0; ri < md->pmd_npmc; ri++) 4233 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL) 4234 do_descendants |= pm->pm_flags & PMC_F_DESCENDANTS; 4235 if (do_descendants == 0) /* nothing to do */ 4236 goto done; 4237 4238 /* allocate a descriptor for the new process */ 4239 if ((ppnew = pmc_find_process_descriptor(newproc, 4240 PMC_FLAG_ALLOCATE)) == NULL) 4241 goto done; 4242 4243 /* 4244 * Run through all PMCs that were targeting the old process 4245 * and which specified F_DESCENDANTS and attach them to the 4246 * new process. 4247 * 4248 * Log the fork event to all owners of PMCs attached to this 4249 * process, if not already logged. 4250 */ 4251 for (ri = 0; ri < md->pmd_npmc; ri++) 4252 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL && 4253 (pm->pm_flags & PMC_F_DESCENDANTS)) { 4254 pmc_link_target_process(pm, ppnew); 4255 po = pm->pm_owner; 4256 if (po->po_sscount == 0 && 4257 po->po_flags & PMC_PO_OWNS_LOGFILE) 4258 pmclog_process_procfork(po, p1->p_pid, 4259 newproc->p_pid); 4260 } 4261 4262 /* 4263 * Now mark the new process as being tracked by this driver. 4264 */ 4265 PROC_LOCK(newproc); 4266 newproc->p_flag |= P_HWPMC; 4267 PROC_UNLOCK(newproc); 4268 4269 done: 4270 sx_xunlock(&pmc_sx); 4271 } 4272 4273 4274 /* 4275 * initialization 4276 */ 4277 4278 static const char *pmc_name_of_pmcclass[] = { 4279 #undef __PMC_CLASS 4280 #define __PMC_CLASS(N) #N , 4281 __PMC_CLASSES() 4282 }; 4283 4284 static int 4285 pmc_initialize(void) 4286 { 4287 int cpu, error, n; 4288 unsigned int maxcpu; 4289 struct pmc_binding pb; 4290 struct pmc_sample *ps; 4291 struct pmc_samplebuffer *sb; 4292 4293 md = NULL; 4294 error = 0; 4295 4296 #ifdef DEBUG 4297 /* parse debug flags first */ 4298 if (TUNABLE_STR_FETCH(PMC_SYSCTL_NAME_PREFIX "debugflags", 4299 pmc_debugstr, sizeof(pmc_debugstr))) 4300 pmc_debugflags_parse(pmc_debugstr, 4301 pmc_debugstr+strlen(pmc_debugstr)); 4302 #endif 4303 4304 PMCDBG(MOD,INI,0, "PMC Initialize (version %x)", PMC_VERSION); 4305 4306 /* check kernel version */ 4307 if (pmc_kernel_version != PMC_VERSION) { 4308 if (pmc_kernel_version == 0) 4309 printf("hwpmc: this kernel has not been compiled with " 4310 "'options HWPMC_HOOKS'.\n"); 4311 else 4312 printf("hwpmc: kernel version (0x%x) does not match " 4313 "module version (0x%x).\n", pmc_kernel_version, 4314 PMC_VERSION); 4315 return EPROGMISMATCH; 4316 } 4317 4318 /* 4319 * check sysctl parameters 4320 */ 4321 4322 if (pmc_hashsize <= 0) { 4323 (void) printf("hwpmc: tunable \"hashsize\"=%d must be " 4324 "greater than zero.\n", pmc_hashsize); 4325 pmc_hashsize = PMC_HASH_SIZE; 4326 } 4327 4328 if (pmc_nsamples <= 0 || pmc_nsamples > 65535) { 4329 (void) printf("hwpmc: tunable \"nsamples\"=%d out of " 4330 "range.\n", pmc_nsamples); 4331 pmc_nsamples = PMC_NSAMPLES; 4332 } 4333 4334 if (pmc_callchaindepth <= 0 || 4335 pmc_callchaindepth > PMC_CALLCHAIN_DEPTH_MAX) { 4336 (void) printf("hwpmc: tunable \"callchaindepth\"=%d out of " 4337 "range.\n", pmc_callchaindepth); 4338 pmc_callchaindepth = PMC_CALLCHAIN_DEPTH; 4339 } 4340 4341 md = pmc_md_initialize(); 4342 4343 if (md == NULL || md->pmd_init == NULL) 4344 return ENOSYS; 4345 4346 maxcpu = pmc_cpu_max(); 4347 4348 /* allocate space for the per-cpu array */ 4349 pmc_pcpu = malloc(maxcpu * sizeof(struct pmc_cpu *), 4350 M_PMC, M_WAITOK|M_ZERO); 4351 4352 /* per-cpu 'saved values' for managing process-mode PMCs */ 4353 pmc_pcpu_saved = malloc(sizeof(pmc_value_t) * maxcpu * md->pmd_npmc, 4354 M_PMC, M_WAITOK); 4355 4356 /* Perform CPU-dependent initialization. */ 4357 pmc_save_cpu_binding(&pb); 4358 for (cpu = 0; cpu < maxcpu; cpu++) { 4359 if (!pmc_cpu_is_active(cpu)) 4360 continue; 4361 pmc_select_cpu(cpu); 4362 if ((error = md->pmd_init(cpu)) != 0) 4363 break; 4364 } 4365 pmc_restore_cpu_binding(&pb); 4366 4367 if (error != 0) 4368 return error; 4369 4370 /* allocate space for the sample array */ 4371 for (cpu = 0; cpu < maxcpu; cpu++) { 4372 if (!pmc_cpu_is_active(cpu)) 4373 continue; 4374 sb = malloc(sizeof(struct pmc_samplebuffer) + 4375 pmc_nsamples * sizeof(struct pmc_sample), M_PMC, 4376 M_WAITOK|M_ZERO); 4377 4378 sb->ps_read = sb->ps_write = sb->ps_samples; 4379 sb->ps_fence = sb->ps_samples + pmc_nsamples; 4380 KASSERT(pmc_pcpu[cpu] != NULL, 4381 ("[pmc,%d] cpu=%d Null per-cpu data", __LINE__, cpu)); 4382 4383 sb->ps_callchains = malloc(pmc_callchaindepth * 4384 pmc_nsamples * sizeof(uintptr_t), 4385 M_PMC, M_WAITOK|M_ZERO); 4386 4387 for (n = 0, ps = sb->ps_samples; n < pmc_nsamples; n++, ps++) 4388 ps->ps_pc = sb->ps_callchains + 4389 (n * pmc_callchaindepth); 4390 4391 pmc_pcpu[cpu]->pc_sb = sb; 4392 } 4393 4394 /* allocate space for the row disposition array */ 4395 pmc_pmcdisp = malloc(sizeof(enum pmc_mode) * md->pmd_npmc, 4396 M_PMC, M_WAITOK|M_ZERO); 4397 4398 KASSERT(pmc_pmcdisp != NULL, 4399 ("[pmc,%d] pmcdisp allocation returned NULL", __LINE__)); 4400 4401 /* mark all PMCs as available */ 4402 for (n = 0; n < (int) md->pmd_npmc; n++) 4403 PMC_MARK_ROW_FREE(n); 4404 4405 /* allocate thread hash tables */ 4406 pmc_ownerhash = hashinit(pmc_hashsize, M_PMC, 4407 &pmc_ownerhashmask); 4408 4409 pmc_processhash = hashinit(pmc_hashsize, M_PMC, 4410 &pmc_processhashmask); 4411 mtx_init(&pmc_processhash_mtx, "pmc-process-hash", "pmc-leaf", 4412 MTX_SPIN); 4413 4414 LIST_INIT(&pmc_ss_owners); 4415 pmc_ss_count = 0; 4416 4417 /* allocate a pool of spin mutexes */ 4418 pmc_mtxpool = mtx_pool_create("pmc-leaf", pmc_mtxpool_size, 4419 MTX_SPIN); 4420 4421 PMCDBG(MOD,INI,1, "pmc_ownerhash=%p, mask=0x%lx " 4422 "targethash=%p mask=0x%lx", pmc_ownerhash, pmc_ownerhashmask, 4423 pmc_processhash, pmc_processhashmask); 4424 4425 /* register process {exit,fork,exec} handlers */ 4426 pmc_exit_tag = EVENTHANDLER_REGISTER(process_exit, 4427 pmc_process_exit, NULL, EVENTHANDLER_PRI_ANY); 4428 pmc_fork_tag = EVENTHANDLER_REGISTER(process_fork, 4429 pmc_process_fork, NULL, EVENTHANDLER_PRI_ANY); 4430 4431 /* initialize logging */ 4432 pmclog_initialize(); 4433 4434 /* set hook functions */ 4435 pmc_intr = md->pmd_intr; 4436 pmc_hook = pmc_hook_handler; 4437 4438 if (error == 0) { 4439 printf(PMC_MODULE_NAME ":"); 4440 for (n = 0; n < (int) md->pmd_nclass; n++) { 4441 printf(" %s/%d/0x%b", 4442 pmc_name_of_pmcclass[md->pmd_classes[n].pm_class], 4443 md->pmd_nclasspmcs[n], 4444 md->pmd_classes[n].pm_caps, 4445 "\20" 4446 "\1INT\2USR\3SYS\4EDG\5THR" 4447 "\6REA\7WRI\10INV\11QUA\12PRC" 4448 "\13TAG\14CSC"); 4449 } 4450 printf("\n"); 4451 } 4452 4453 return error; 4454 } 4455 4456 /* prepare to be unloaded */ 4457 static void 4458 pmc_cleanup(void) 4459 { 4460 int cpu; 4461 unsigned int maxcpu; 4462 struct pmc_ownerhash *ph; 4463 struct pmc_owner *po, *tmp; 4464 struct pmc_binding pb; 4465 #ifdef DEBUG 4466 struct pmc_processhash *prh; 4467 #endif 4468 4469 PMCDBG(MOD,INI,0, "%s", "cleanup"); 4470 4471 /* switch off sampling */ 4472 atomic_store_rel_int(&pmc_cpumask, 0); 4473 pmc_intr = NULL; 4474 4475 sx_xlock(&pmc_sx); 4476 if (pmc_hook == NULL) { /* being unloaded already */ 4477 sx_xunlock(&pmc_sx); 4478 return; 4479 } 4480 4481 pmc_hook = NULL; /* prevent new threads from entering module */ 4482 4483 /* deregister event handlers */ 4484 EVENTHANDLER_DEREGISTER(process_fork, pmc_fork_tag); 4485 EVENTHANDLER_DEREGISTER(process_exit, pmc_exit_tag); 4486 4487 /* send SIGBUS to all owner threads, free up allocations */ 4488 if (pmc_ownerhash) 4489 for (ph = pmc_ownerhash; 4490 ph <= &pmc_ownerhash[pmc_ownerhashmask]; 4491 ph++) { 4492 LIST_FOREACH_SAFE(po, ph, po_next, tmp) { 4493 pmc_remove_owner(po); 4494 4495 /* send SIGBUS to owner processes */ 4496 PMCDBG(MOD,INI,2, "cleanup signal proc=%p " 4497 "(%d, %s)", po->po_owner, 4498 po->po_owner->p_pid, 4499 po->po_owner->p_comm); 4500 4501 PROC_LOCK(po->po_owner); 4502 psignal(po->po_owner, SIGBUS); 4503 PROC_UNLOCK(po->po_owner); 4504 4505 pmc_destroy_owner_descriptor(po); 4506 } 4507 } 4508 4509 /* reclaim allocated data structures */ 4510 if (pmc_mtxpool) 4511 mtx_pool_destroy(&pmc_mtxpool); 4512 4513 mtx_destroy(&pmc_processhash_mtx); 4514 if (pmc_processhash) { 4515 #ifdef DEBUG 4516 struct pmc_process *pp; 4517 4518 PMCDBG(MOD,INI,3, "%s", "destroy process hash"); 4519 for (prh = pmc_processhash; 4520 prh <= &pmc_processhash[pmc_processhashmask]; 4521 prh++) 4522 LIST_FOREACH(pp, prh, pp_next) 4523 PMCDBG(MOD,INI,3, "pid=%d", pp->pp_proc->p_pid); 4524 #endif 4525 4526 hashdestroy(pmc_processhash, M_PMC, pmc_processhashmask); 4527 pmc_processhash = NULL; 4528 } 4529 4530 if (pmc_ownerhash) { 4531 PMCDBG(MOD,INI,3, "%s", "destroy owner hash"); 4532 hashdestroy(pmc_ownerhash, M_PMC, pmc_ownerhashmask); 4533 pmc_ownerhash = NULL; 4534 } 4535 4536 KASSERT(LIST_EMPTY(&pmc_ss_owners), 4537 ("[pmc,%d] Global SS owner list not empty", __LINE__)); 4538 KASSERT(pmc_ss_count == 0, 4539 ("[pmc,%d] Global SS count not empty", __LINE__)); 4540 4541 /* Free the per-cpu sample buffers. */ 4542 maxcpu = pmc_cpu_max(); 4543 for (cpu = 0; cpu < maxcpu; cpu++) { 4544 if (!pmc_cpu_is_active(cpu)) 4545 continue; 4546 KASSERT(pmc_pcpu[cpu]->pc_sb != NULL, 4547 ("[pmc,%d] Null cpu sample buffer cpu=%d", __LINE__, 4548 cpu)); 4549 free(pmc_pcpu[cpu]->pc_sb->ps_callchains, M_PMC); 4550 free(pmc_pcpu[cpu]->pc_sb, M_PMC); 4551 pmc_pcpu[cpu]->pc_sb = NULL; 4552 } 4553 4554 /* do processor dependent cleanup */ 4555 PMCDBG(MOD,INI,3, "%s", "md cleanup"); 4556 if (md) { 4557 pmc_save_cpu_binding(&pb); 4558 for (cpu = 0; cpu < maxcpu; cpu++) { 4559 PMCDBG(MOD,INI,1,"pmc-cleanup cpu=%d pcs=%p", 4560 cpu, pmc_pcpu[cpu]); 4561 if (!pmc_cpu_is_active(cpu) || pmc_pcpu[cpu] == NULL) 4562 continue; 4563 pmc_select_cpu(cpu); 4564 if (md->pmd_cleanup) 4565 md->pmd_cleanup(cpu); 4566 } 4567 free(md, M_PMC); 4568 md = NULL; 4569 pmc_restore_cpu_binding(&pb); 4570 } 4571 4572 /* deallocate per-cpu structures */ 4573 free(pmc_pcpu, M_PMC); 4574 pmc_pcpu = NULL; 4575 4576 free(pmc_pcpu_saved, M_PMC); 4577 pmc_pcpu_saved = NULL; 4578 4579 if (pmc_pmcdisp) { 4580 free(pmc_pmcdisp, M_PMC); 4581 pmc_pmcdisp = NULL; 4582 } 4583 4584 pmclog_shutdown(); 4585 4586 sx_xunlock(&pmc_sx); /* we are done */ 4587 } 4588 4589 /* 4590 * The function called at load/unload. 4591 */ 4592 4593 static int 4594 load (struct module *module __unused, int cmd, void *arg __unused) 4595 { 4596 int error; 4597 4598 error = 0; 4599 4600 switch (cmd) { 4601 case MOD_LOAD : 4602 /* initialize the subsystem */ 4603 error = pmc_initialize(); 4604 if (error != 0) 4605 break; 4606 PMCDBG(MOD,INI,1, "syscall=%d maxcpu=%d", 4607 pmc_syscall_num, pmc_cpu_max()); 4608 break; 4609 4610 4611 case MOD_UNLOAD : 4612 case MOD_SHUTDOWN: 4613 pmc_cleanup(); 4614 PMCDBG(MOD,INI,1, "%s", "unloaded"); 4615 break; 4616 4617 default : 4618 error = EINVAL; /* XXX should panic(9) */ 4619 break; 4620 } 4621 4622 return error; 4623 } 4624 4625 /* memory pool */ 4626 MALLOC_DEFINE(M_PMC, "pmc", "Memory space for the PMC module"); 4627