1 /*-
2 * Copyright (c) 2003-2008 Joseph Koshy
3 * Copyright (c) 2007 The FreeBSD Foundation
4 * All rights reserved.
5 *
6 * Portions of this software were developed by A. Joseph Koshy under
7 * sponsorship from the FreeBSD Foundation and Google, Inc.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 *
30 */
31
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD$");
34
35 #include <sys/param.h>
36 #include <sys/eventhandler.h>
37 #include <sys/jail.h>
38 #include <sys/kernel.h>
39 #include <sys/kthread.h>
40 #include <sys/limits.h>
41 #include <sys/lock.h>
42 #include <sys/malloc.h>
43 #include <sys/module.h>
44 #include <sys/mount.h>
45 #include <sys/mutex.h>
46 #include <sys/pmc.h>
47 #include <sys/pmckern.h>
48 #include <sys/pmclog.h>
49 #include <sys/priv.h>
50 #include <sys/proc.h>
51 #include <sys/queue.h>
52 #include <sys/resourcevar.h>
53 #include <sys/rwlock.h>
54 #include <sys/sched.h>
55 #include <sys/signalvar.h>
56 #include <sys/smp.h>
57 #include <sys/sx.h>
58 #include <sys/sysctl.h>
59 #include <sys/sysent.h>
60 #include <sys/systm.h>
61 #include <sys/vnode.h>
62
63 #include <sys/linker.h> /* needs to be after <sys/malloc.h> */
64
65 #include <machine/atomic.h>
66 #include <machine/md_var.h>
67
68 #include <vm/vm.h>
69 #include <vm/vm_extern.h>
70 #include <vm/pmap.h>
71 #include <vm/vm_map.h>
72 #include <vm/vm_object.h>
73
74 #include "hwpmc_soft.h"
75
76 /*
77 * Types
78 */
79
80 enum pmc_flags {
81 PMC_FLAG_NONE = 0x00, /* do nothing */
82 PMC_FLAG_REMOVE = 0x01, /* atomically remove entry from hash */
83 PMC_FLAG_ALLOCATE = 0x02, /* add entry to hash if not found */
84 };
85
86 /*
87 * The offset in sysent where the syscall is allocated.
88 */
89
90 static int pmc_syscall_num = NO_SYSCALL;
91 struct pmc_cpu **pmc_pcpu; /* per-cpu state */
92 pmc_value_t *pmc_pcpu_saved; /* saved PMC values: CSW handling */
93
94 #define PMC_PCPU_SAVED(C,R) pmc_pcpu_saved[(R) + md->pmd_npmc*(C)]
95
96 struct mtx_pool *pmc_mtxpool;
97 static int *pmc_pmcdisp; /* PMC row dispositions */
98
99 #define PMC_ROW_DISP_IS_FREE(R) (pmc_pmcdisp[(R)] == 0)
100 #define PMC_ROW_DISP_IS_THREAD(R) (pmc_pmcdisp[(R)] > 0)
101 #define PMC_ROW_DISP_IS_STANDALONE(R) (pmc_pmcdisp[(R)] < 0)
102
103 #define PMC_MARK_ROW_FREE(R) do { \
104 pmc_pmcdisp[(R)] = 0; \
105 } while (0)
106
107 #define PMC_MARK_ROW_STANDALONE(R) do { \
108 KASSERT(pmc_pmcdisp[(R)] <= 0, ("[pmc,%d] row disposition error", \
109 __LINE__)); \
110 atomic_add_int(&pmc_pmcdisp[(R)], -1); \
111 KASSERT(pmc_pmcdisp[(R)] >= (-pmc_cpu_max_active()), \
112 ("[pmc,%d] row disposition error", __LINE__)); \
113 } while (0)
114
115 #define PMC_UNMARK_ROW_STANDALONE(R) do { \
116 atomic_add_int(&pmc_pmcdisp[(R)], 1); \
117 KASSERT(pmc_pmcdisp[(R)] <= 0, ("[pmc,%d] row disposition error", \
118 __LINE__)); \
119 } while (0)
120
121 #define PMC_MARK_ROW_THREAD(R) do { \
122 KASSERT(pmc_pmcdisp[(R)] >= 0, ("[pmc,%d] row disposition error", \
123 __LINE__)); \
124 atomic_add_int(&pmc_pmcdisp[(R)], 1); \
125 } while (0)
126
127 #define PMC_UNMARK_ROW_THREAD(R) do { \
128 atomic_add_int(&pmc_pmcdisp[(R)], -1); \
129 KASSERT(pmc_pmcdisp[(R)] >= 0, ("[pmc,%d] row disposition error", \
130 __LINE__)); \
131 } while (0)
132
133
134 /* various event handlers */
135 static eventhandler_tag pmc_exit_tag, pmc_fork_tag, pmc_kld_load_tag,
136 pmc_kld_unload_tag;
137
138 /* Module statistics */
139 struct pmc_op_getdriverstats pmc_stats;
140
141 /* Machine/processor dependent operations */
142 static struct pmc_mdep *md;
143
144 /*
145 * Hash tables mapping owner processes and target threads to PMCs.
146 */
147
148 struct mtx pmc_processhash_mtx; /* spin mutex */
149 static u_long pmc_processhashmask;
150 static LIST_HEAD(pmc_processhash, pmc_process) *pmc_processhash;
151
152 /*
153 * Hash table of PMC owner descriptors. This table is protected by
154 * the shared PMC "sx" lock.
155 */
156
157 static u_long pmc_ownerhashmask;
158 static LIST_HEAD(pmc_ownerhash, pmc_owner) *pmc_ownerhash;
159
160 /*
161 * List of PMC owners with system-wide sampling PMCs.
162 */
163
164 static LIST_HEAD(, pmc_owner) pmc_ss_owners;
165
166
167 /*
168 * A map of row indices to classdep structures.
169 */
170 static struct pmc_classdep **pmc_rowindex_to_classdep;
171
172 /*
173 * Prototypes
174 */
175
176 #ifdef HWPMC_DEBUG
177 static int pmc_debugflags_sysctl_handler(SYSCTL_HANDLER_ARGS);
178 static int pmc_debugflags_parse(char *newstr, char *fence);
179 #endif
180
181 static int load(struct module *module, int cmd, void *arg);
182 static int pmc_attach_process(struct proc *p, struct pmc *pm);
183 static struct pmc *pmc_allocate_pmc_descriptor(void);
184 static struct pmc_owner *pmc_allocate_owner_descriptor(struct proc *p);
185 static int pmc_attach_one_process(struct proc *p, struct pmc *pm);
186 static int pmc_can_allocate_rowindex(struct proc *p, unsigned int ri,
187 int cpu);
188 static int pmc_can_attach(struct pmc *pm, struct proc *p);
189 static void pmc_capture_user_callchain(int cpu, int soft, struct trapframe *tf);
190 static void pmc_cleanup(void);
191 static int pmc_detach_process(struct proc *p, struct pmc *pm);
192 static int pmc_detach_one_process(struct proc *p, struct pmc *pm,
193 int flags);
194 static void pmc_destroy_owner_descriptor(struct pmc_owner *po);
195 static void pmc_destroy_pmc_descriptor(struct pmc *pm);
196 static struct pmc_owner *pmc_find_owner_descriptor(struct proc *p);
197 static int pmc_find_pmc(pmc_id_t pmcid, struct pmc **pm);
198 static struct pmc *pmc_find_pmc_descriptor_in_process(struct pmc_owner *po,
199 pmc_id_t pmc);
200 static struct pmc_process *pmc_find_process_descriptor(struct proc *p,
201 uint32_t mode);
202 static void pmc_force_context_switch(void);
203 static void pmc_link_target_process(struct pmc *pm,
204 struct pmc_process *pp);
205 static void pmc_log_all_process_mappings(struct pmc_owner *po);
206 static void pmc_log_kernel_mappings(struct pmc *pm);
207 static void pmc_log_process_mappings(struct pmc_owner *po, struct proc *p);
208 static void pmc_maybe_remove_owner(struct pmc_owner *po);
209 static void pmc_process_csw_in(struct thread *td);
210 static void pmc_process_csw_out(struct thread *td);
211 static void pmc_process_exit(void *arg, struct proc *p);
212 static void pmc_process_fork(void *arg, struct proc *p1,
213 struct proc *p2, int n);
214 static void pmc_process_samples(int cpu, int soft);
215 static void pmc_release_pmc_descriptor(struct pmc *pmc);
216 static void pmc_remove_owner(struct pmc_owner *po);
217 static void pmc_remove_process_descriptor(struct pmc_process *pp);
218 static void pmc_restore_cpu_binding(struct pmc_binding *pb);
219 static void pmc_save_cpu_binding(struct pmc_binding *pb);
220 static void pmc_select_cpu(int cpu);
221 static int pmc_start(struct pmc *pm);
222 static int pmc_stop(struct pmc *pm);
223 static int pmc_syscall_handler(struct thread *td, void *syscall_args);
224 static void pmc_unlink_target_process(struct pmc *pmc,
225 struct pmc_process *pp);
226 static int generic_switch_in(struct pmc_cpu *pc, struct pmc_process *pp);
227 static int generic_switch_out(struct pmc_cpu *pc, struct pmc_process *pp);
228 static struct pmc_mdep *pmc_generic_cpu_initialize(void);
229 static void pmc_generic_cpu_finalize(struct pmc_mdep *md);
230
231 /*
232 * Kernel tunables and sysctl(8) interface.
233 */
234
235 SYSCTL_DECL(_kern_hwpmc);
236
237 static int pmc_callchaindepth = PMC_CALLCHAIN_DEPTH;
238 SYSCTL_INT(_kern_hwpmc, OID_AUTO, callchaindepth, CTLFLAG_RDTUN,
239 &pmc_callchaindepth, 0, "depth of call chain records");
240
241 #ifdef HWPMC_DEBUG
242 struct pmc_debugflags pmc_debugflags = PMC_DEBUG_DEFAULT_FLAGS;
243 char pmc_debugstr[PMC_DEBUG_STRSIZE];
244 TUNABLE_STR(PMC_SYSCTL_NAME_PREFIX "debugflags", pmc_debugstr,
245 sizeof(pmc_debugstr));
246 SYSCTL_PROC(_kern_hwpmc, OID_AUTO, debugflags,
247 CTLTYPE_STRING | CTLFLAG_RWTUN | CTLFLAG_NOFETCH,
248 0, 0, pmc_debugflags_sysctl_handler, "A", "debug flags");
249 #endif
250
251 /*
252 * kern.hwpmc.hashrows -- determines the number of rows in the
253 * of the hash table used to look up threads
254 */
255
256 static int pmc_hashsize = PMC_HASH_SIZE;
257 SYSCTL_INT(_kern_hwpmc, OID_AUTO, hashsize, CTLFLAG_RDTUN,
258 &pmc_hashsize, 0, "rows in hash tables");
259
260 /*
261 * kern.hwpmc.nsamples --- number of PC samples/callchain stacks per CPU
262 */
263
264 static int pmc_nsamples = PMC_NSAMPLES;
265 SYSCTL_INT(_kern_hwpmc, OID_AUTO, nsamples, CTLFLAG_RDTUN,
266 &pmc_nsamples, 0, "number of PC samples per CPU");
267
268
269 /*
270 * kern.hwpmc.mtxpoolsize -- number of mutexes in the mutex pool.
271 */
272
273 static int pmc_mtxpool_size = PMC_MTXPOOL_SIZE;
274 SYSCTL_INT(_kern_hwpmc, OID_AUTO, mtxpoolsize, CTLFLAG_RDTUN,
275 &pmc_mtxpool_size, 0, "size of spin mutex pool");
276
277
278 /*
279 * security.bsd.unprivileged_syspmcs -- allow non-root processes to
280 * allocate system-wide PMCs.
281 *
282 * Allowing unprivileged processes to allocate system PMCs is convenient
283 * if system-wide measurements need to be taken concurrently with other
284 * per-process measurements. This feature is turned off by default.
285 */
286
287 static int pmc_unprivileged_syspmcs = 0;
288 SYSCTL_INT(_security_bsd, OID_AUTO, unprivileged_syspmcs, CTLFLAG_RWTUN,
289 &pmc_unprivileged_syspmcs, 0,
290 "allow unprivileged process to allocate system PMCs");
291
292 /*
293 * Hash function. Discard the lower 2 bits of the pointer since
294 * these are always zero for our uses. The hash multiplier is
295 * round((2^LONG_BIT) * ((sqrt(5)-1)/2)).
296 */
297
298 #if LONG_BIT == 64
299 #define _PMC_HM 11400714819323198486u
300 #elif LONG_BIT == 32
301 #define _PMC_HM 2654435769u
302 #else
303 #error Must know the size of 'long' to compile
304 #endif
305
306 #define PMC_HASH_PTR(P,M) ((((unsigned long) (P) >> 2) * _PMC_HM) & (M))
307
308 /*
309 * Syscall structures
310 */
311
312 /* The `sysent' for the new syscall */
313 static struct sysent pmc_sysent = {
314 2, /* sy_narg */
315 pmc_syscall_handler /* sy_call */
316 };
317
318 static struct syscall_module_data pmc_syscall_mod = {
319 load,
320 NULL,
321 &pmc_syscall_num,
322 &pmc_sysent,
323 #if (__FreeBSD_version >= 1100000)
324 { 0, NULL },
325 SY_THR_STATIC_KLD,
326 #else
327 { 0, NULL }
328 #endif
329 };
330
331 static moduledata_t pmc_mod = {
332 PMC_MODULE_NAME,
333 syscall_module_handler,
334 &pmc_syscall_mod
335 };
336
337 DECLARE_MODULE(pmc, pmc_mod, SI_SUB_SMP, SI_ORDER_ANY);
338 MODULE_VERSION(pmc, PMC_VERSION);
339
340 #ifdef HWPMC_DEBUG
341 enum pmc_dbgparse_state {
342 PMCDS_WS, /* in whitespace */
343 PMCDS_MAJOR, /* seen a major keyword */
344 PMCDS_MINOR
345 };
346
347 static int
pmc_debugflags_parse(char * newstr,char * fence)348 pmc_debugflags_parse(char *newstr, char *fence)
349 {
350 char c, *p, *q;
351 struct pmc_debugflags *tmpflags;
352 int error, found, *newbits, tmp;
353 size_t kwlen;
354
355 tmpflags = malloc(sizeof(*tmpflags), M_PMC, M_WAITOK|M_ZERO);
356
357 p = newstr;
358 error = 0;
359
360 for (; p < fence && (c = *p); p++) {
361
362 /* skip white space */
363 if (c == ' ' || c == '\t')
364 continue;
365
366 /* look for a keyword followed by "=" */
367 for (q = p; p < fence && (c = *p) && c != '='; p++)
368 ;
369 if (c != '=') {
370 error = EINVAL;
371 goto done;
372 }
373
374 kwlen = p - q;
375 newbits = NULL;
376
377 /* lookup flag group name */
378 #define DBG_SET_FLAG_MAJ(S,F) \
379 if (kwlen == sizeof(S)-1 && strncmp(q, S, kwlen) == 0) \
380 newbits = &tmpflags->pdb_ ## F;
381
382 DBG_SET_FLAG_MAJ("cpu", CPU);
383 DBG_SET_FLAG_MAJ("csw", CSW);
384 DBG_SET_FLAG_MAJ("logging", LOG);
385 DBG_SET_FLAG_MAJ("module", MOD);
386 DBG_SET_FLAG_MAJ("md", MDP);
387 DBG_SET_FLAG_MAJ("owner", OWN);
388 DBG_SET_FLAG_MAJ("pmc", PMC);
389 DBG_SET_FLAG_MAJ("process", PRC);
390 DBG_SET_FLAG_MAJ("sampling", SAM);
391
392 if (newbits == NULL) {
393 error = EINVAL;
394 goto done;
395 }
396
397 p++; /* skip the '=' */
398
399 /* Now parse the individual flags */
400 tmp = 0;
401 newflag:
402 for (q = p; p < fence && (c = *p); p++)
403 if (c == ' ' || c == '\t' || c == ',')
404 break;
405
406 /* p == fence or c == ws or c == "," or c == 0 */
407
408 if ((kwlen = p - q) == 0) {
409 *newbits = tmp;
410 continue;
411 }
412
413 found = 0;
414 #define DBG_SET_FLAG_MIN(S,F) \
415 if (kwlen == sizeof(S)-1 && strncmp(q, S, kwlen) == 0) \
416 tmp |= found = (1 << PMC_DEBUG_MIN_ ## F)
417
418 /* a '*' denotes all possible flags in the group */
419 if (kwlen == 1 && *q == '*')
420 tmp = found = ~0;
421 /* look for individual flag names */
422 DBG_SET_FLAG_MIN("allocaterow", ALR);
423 DBG_SET_FLAG_MIN("allocate", ALL);
424 DBG_SET_FLAG_MIN("attach", ATT);
425 DBG_SET_FLAG_MIN("bind", BND);
426 DBG_SET_FLAG_MIN("config", CFG);
427 DBG_SET_FLAG_MIN("exec", EXC);
428 DBG_SET_FLAG_MIN("exit", EXT);
429 DBG_SET_FLAG_MIN("find", FND);
430 DBG_SET_FLAG_MIN("flush", FLS);
431 DBG_SET_FLAG_MIN("fork", FRK);
432 DBG_SET_FLAG_MIN("getbuf", GTB);
433 DBG_SET_FLAG_MIN("hook", PMH);
434 DBG_SET_FLAG_MIN("init", INI);
435 DBG_SET_FLAG_MIN("intr", INT);
436 DBG_SET_FLAG_MIN("linktarget", TLK);
437 DBG_SET_FLAG_MIN("mayberemove", OMR);
438 DBG_SET_FLAG_MIN("ops", OPS);
439 DBG_SET_FLAG_MIN("read", REA);
440 DBG_SET_FLAG_MIN("register", REG);
441 DBG_SET_FLAG_MIN("release", REL);
442 DBG_SET_FLAG_MIN("remove", ORM);
443 DBG_SET_FLAG_MIN("sample", SAM);
444 DBG_SET_FLAG_MIN("scheduleio", SIO);
445 DBG_SET_FLAG_MIN("select", SEL);
446 DBG_SET_FLAG_MIN("signal", SIG);
447 DBG_SET_FLAG_MIN("swi", SWI);
448 DBG_SET_FLAG_MIN("swo", SWO);
449 DBG_SET_FLAG_MIN("start", STA);
450 DBG_SET_FLAG_MIN("stop", STO);
451 DBG_SET_FLAG_MIN("syscall", PMS);
452 DBG_SET_FLAG_MIN("unlinktarget", TUL);
453 DBG_SET_FLAG_MIN("write", WRI);
454 if (found == 0) {
455 /* unrecognized flag name */
456 error = EINVAL;
457 goto done;
458 }
459
460 if (c == 0 || c == ' ' || c == '\t') { /* end of flag group */
461 *newbits = tmp;
462 continue;
463 }
464
465 p++;
466 goto newflag;
467 }
468
469 /* save the new flag set */
470 bcopy(tmpflags, &pmc_debugflags, sizeof(pmc_debugflags));
471
472 done:
473 free(tmpflags, M_PMC);
474 return error;
475 }
476
477 static int
pmc_debugflags_sysctl_handler(SYSCTL_HANDLER_ARGS)478 pmc_debugflags_sysctl_handler(SYSCTL_HANDLER_ARGS)
479 {
480 char *fence, *newstr;
481 int error;
482 unsigned int n;
483
484 (void) arg1; (void) arg2; /* unused parameters */
485
486 n = sizeof(pmc_debugstr);
487 newstr = malloc(n, M_PMC, M_WAITOK|M_ZERO);
488 (void) strlcpy(newstr, pmc_debugstr, n);
489
490 error = sysctl_handle_string(oidp, newstr, n, req);
491
492 /* if there is a new string, parse and copy it */
493 if (error == 0 && req->newptr != NULL) {
494 fence = newstr + (n < req->newlen ? n : req->newlen + 1);
495 if ((error = pmc_debugflags_parse(newstr, fence)) == 0)
496 (void) strlcpy(pmc_debugstr, newstr,
497 sizeof(pmc_debugstr));
498 }
499
500 free(newstr, M_PMC);
501
502 return error;
503 }
504 #endif
505
506 /*
507 * Map a row index to a classdep structure and return the adjusted row
508 * index for the PMC class index.
509 */
510 static struct pmc_classdep *
pmc_ri_to_classdep(struct pmc_mdep * md,int ri,int * adjri)511 pmc_ri_to_classdep(struct pmc_mdep *md, int ri, int *adjri)
512 {
513 struct pmc_classdep *pcd;
514
515 (void) md;
516
517 KASSERT(ri >= 0 && ri < md->pmd_npmc,
518 ("[pmc,%d] illegal row-index %d", __LINE__, ri));
519
520 pcd = pmc_rowindex_to_classdep[ri];
521
522 KASSERT(pcd != NULL,
523 ("[pmc,%d] ri %d null pcd", __LINE__, ri));
524
525 *adjri = ri - pcd->pcd_ri;
526
527 KASSERT(*adjri >= 0 && *adjri < pcd->pcd_num,
528 ("[pmc,%d] adjusted row-index %d", __LINE__, *adjri));
529
530 return (pcd);
531 }
532
533 /*
534 * Concurrency Control
535 *
536 * The driver manages the following data structures:
537 *
538 * - target process descriptors, one per target process
539 * - owner process descriptors (and attached lists), one per owner process
540 * - lookup hash tables for owner and target processes
541 * - PMC descriptors (and attached lists)
542 * - per-cpu hardware state
543 * - the 'hook' variable through which the kernel calls into
544 * this module
545 * - the machine hardware state (managed by the MD layer)
546 *
547 * These data structures are accessed from:
548 *
549 * - thread context-switch code
550 * - interrupt handlers (possibly on multiple cpus)
551 * - kernel threads on multiple cpus running on behalf of user
552 * processes doing system calls
553 * - this driver's private kernel threads
554 *
555 * = Locks and Locking strategy =
556 *
557 * The driver uses four locking strategies for its operation:
558 *
559 * - The global SX lock "pmc_sx" is used to protect internal
560 * data structures.
561 *
562 * Calls into the module by syscall() start with this lock being
563 * held in exclusive mode. Depending on the requested operation,
564 * the lock may be downgraded to 'shared' mode to allow more
565 * concurrent readers into the module. Calls into the module from
566 * other parts of the kernel acquire the lock in shared mode.
567 *
568 * This SX lock is held in exclusive mode for any operations that
569 * modify the linkages between the driver's internal data structures.
570 *
571 * The 'pmc_hook' function pointer is also protected by this lock.
572 * It is only examined with the sx lock held in exclusive mode. The
573 * kernel module is allowed to be unloaded only with the sx lock held
574 * in exclusive mode. In normal syscall handling, after acquiring the
575 * pmc_sx lock we first check that 'pmc_hook' is non-null before
576 * proceeding. This prevents races between the thread unloading the module
577 * and other threads seeking to use the module.
578 *
579 * - Lookups of target process structures and owner process structures
580 * cannot use the global "pmc_sx" SX lock because these lookups need
581 * to happen during context switches and in other critical sections
582 * where sleeping is not allowed. We protect these lookup tables
583 * with their own private spin-mutexes, "pmc_processhash_mtx" and
584 * "pmc_ownerhash_mtx".
585 *
586 * - Interrupt handlers work in a lock free manner. At interrupt
587 * time, handlers look at the PMC pointer (phw->phw_pmc) configured
588 * when the PMC was started. If this pointer is NULL, the interrupt
589 * is ignored after updating driver statistics. We ensure that this
590 * pointer is set (using an atomic operation if necessary) before the
591 * PMC hardware is started. Conversely, this pointer is unset atomically
592 * only after the PMC hardware is stopped.
593 *
594 * We ensure that everything needed for the operation of an
595 * interrupt handler is available without it needing to acquire any
596 * locks. We also ensure that a PMC's software state is destroyed only
597 * after the PMC is taken off hardware (on all CPUs).
598 *
599 * - Context-switch handling with process-private PMCs needs more
600 * care.
601 *
602 * A given process may be the target of multiple PMCs. For example,
603 * PMCATTACH and PMCDETACH may be requested by a process on one CPU
604 * while the target process is running on another. A PMC could also
605 * be getting released because its owner is exiting. We tackle
606 * these situations in the following manner:
607 *
608 * - each target process structure 'pmc_process' has an array
609 * of 'struct pmc *' pointers, one for each hardware PMC.
610 *
611 * - At context switch IN time, each "target" PMC in RUNNING state
612 * gets started on hardware and a pointer to each PMC is copied into
613 * the per-cpu phw array. The 'runcount' for the PMC is
614 * incremented.
615 *
616 * - At context switch OUT time, all process-virtual PMCs are stopped
617 * on hardware. The saved value is added to the PMCs value field
618 * only if the PMC is in a non-deleted state (the PMCs state could
619 * have changed during the current time slice).
620 *
621 * Note that since in-between a switch IN on a processor and a switch
622 * OUT, the PMC could have been released on another CPU. Therefore
623 * context switch OUT always looks at the hardware state to turn
624 * OFF PMCs and will update a PMC's saved value only if reachable
625 * from the target process record.
626 *
627 * - OP PMCRELEASE could be called on a PMC at any time (the PMC could
628 * be attached to many processes at the time of the call and could
629 * be active on multiple CPUs).
630 *
631 * We prevent further scheduling of the PMC by marking it as in
632 * state 'DELETED'. If the runcount of the PMC is non-zero then
633 * this PMC is currently running on a CPU somewhere. The thread
634 * doing the PMCRELEASE operation waits by repeatedly doing a
635 * pause() till the runcount comes to zero.
636 *
637 * The contents of a PMC descriptor (struct pmc) are protected using
638 * a spin-mutex. In order to save space, we use a mutex pool.
639 *
640 * In terms of lock types used by witness(4), we use:
641 * - Type "pmc-sx", used by the global SX lock.
642 * - Type "pmc-sleep", for sleep mutexes used by logger threads.
643 * - Type "pmc-per-proc", for protecting PMC owner descriptors.
644 * - Type "pmc-leaf", used for all other spin mutexes.
645 */
646
647 /*
648 * save the cpu binding of the current kthread
649 */
650
651 static void
pmc_save_cpu_binding(struct pmc_binding * pb)652 pmc_save_cpu_binding(struct pmc_binding *pb)
653 {
654 PMCDBG0(CPU,BND,2, "save-cpu");
655 thread_lock(curthread);
656 pb->pb_bound = sched_is_bound(curthread);
657 pb->pb_cpu = curthread->td_oncpu;
658 thread_unlock(curthread);
659 PMCDBG1(CPU,BND,2, "save-cpu cpu=%d", pb->pb_cpu);
660 }
661
662 /*
663 * restore the cpu binding of the current thread
664 */
665
666 static void
pmc_restore_cpu_binding(struct pmc_binding * pb)667 pmc_restore_cpu_binding(struct pmc_binding *pb)
668 {
669 PMCDBG2(CPU,BND,2, "restore-cpu curcpu=%d restore=%d",
670 curthread->td_oncpu, pb->pb_cpu);
671 thread_lock(curthread);
672 if (pb->pb_bound)
673 sched_bind(curthread, pb->pb_cpu);
674 else
675 sched_unbind(curthread);
676 thread_unlock(curthread);
677 PMCDBG0(CPU,BND,2, "restore-cpu done");
678 }
679
680 /*
681 * move execution over the specified cpu and bind it there.
682 */
683
684 static void
pmc_select_cpu(int cpu)685 pmc_select_cpu(int cpu)
686 {
687 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
688 ("[pmc,%d] bad cpu number %d", __LINE__, cpu));
689
690 /* Never move to an inactive CPU. */
691 KASSERT(pmc_cpu_is_active(cpu), ("[pmc,%d] selecting inactive "
692 "CPU %d", __LINE__, cpu));
693
694 PMCDBG1(CPU,SEL,2, "select-cpu cpu=%d", cpu);
695 thread_lock(curthread);
696 sched_bind(curthread, cpu);
697 thread_unlock(curthread);
698
699 KASSERT(curthread->td_oncpu == cpu,
700 ("[pmc,%d] CPU not bound [cpu=%d, curr=%d]", __LINE__,
701 cpu, curthread->td_oncpu));
702
703 PMCDBG1(CPU,SEL,2, "select-cpu cpu=%d ok", cpu);
704 }
705
706 /*
707 * Force a context switch.
708 *
709 * We do this by pause'ing for 1 tick -- invoking mi_switch() is not
710 * guaranteed to force a context switch.
711 */
712
713 static void
pmc_force_context_switch(void)714 pmc_force_context_switch(void)
715 {
716
717 pause("pmcctx", 1);
718 }
719
720 /*
721 * Get the file name for an executable. This is a simple wrapper
722 * around vn_fullpath(9).
723 */
724
725 static void
pmc_getfilename(struct vnode * v,char ** fullpath,char ** freepath)726 pmc_getfilename(struct vnode *v, char **fullpath, char **freepath)
727 {
728
729 *fullpath = "unknown";
730 *freepath = NULL;
731 vn_fullpath(curthread, v, fullpath, freepath);
732 }
733
734 /*
735 * remove an process owning PMCs
736 */
737
738 void
pmc_remove_owner(struct pmc_owner * po)739 pmc_remove_owner(struct pmc_owner *po)
740 {
741 struct pmc *pm, *tmp;
742
743 sx_assert(&pmc_sx, SX_XLOCKED);
744
745 PMCDBG1(OWN,ORM,1, "remove-owner po=%p", po);
746
747 /* Remove descriptor from the owner hash table */
748 LIST_REMOVE(po, po_next);
749
750 /* release all owned PMC descriptors */
751 LIST_FOREACH_SAFE(pm, &po->po_pmcs, pm_next, tmp) {
752 PMCDBG1(OWN,ORM,2, "pmc=%p", pm);
753 KASSERT(pm->pm_owner == po,
754 ("[pmc,%d] owner %p != po %p", __LINE__, pm->pm_owner, po));
755
756 pmc_release_pmc_descriptor(pm); /* will unlink from the list */
757 pmc_destroy_pmc_descriptor(pm);
758 }
759
760 KASSERT(po->po_sscount == 0,
761 ("[pmc,%d] SS count not zero", __LINE__));
762 KASSERT(LIST_EMPTY(&po->po_pmcs),
763 ("[pmc,%d] PMC list not empty", __LINE__));
764
765 /* de-configure the log file if present */
766 if (po->po_flags & PMC_PO_OWNS_LOGFILE)
767 pmclog_deconfigure_log(po);
768 }
769
770 /*
771 * remove an owner process record if all conditions are met.
772 */
773
774 static void
pmc_maybe_remove_owner(struct pmc_owner * po)775 pmc_maybe_remove_owner(struct pmc_owner *po)
776 {
777
778 PMCDBG1(OWN,OMR,1, "maybe-remove-owner po=%p", po);
779
780 /*
781 * Remove owner record if
782 * - this process does not own any PMCs
783 * - this process has not allocated a system-wide sampling buffer
784 */
785
786 if (LIST_EMPTY(&po->po_pmcs) &&
787 ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0)) {
788 pmc_remove_owner(po);
789 pmc_destroy_owner_descriptor(po);
790 }
791 }
792
793 /*
794 * Add an association between a target process and a PMC.
795 */
796
797 static void
pmc_link_target_process(struct pmc * pm,struct pmc_process * pp)798 pmc_link_target_process(struct pmc *pm, struct pmc_process *pp)
799 {
800 int ri;
801 struct pmc_target *pt;
802
803 sx_assert(&pmc_sx, SX_XLOCKED);
804
805 KASSERT(pm != NULL && pp != NULL,
806 ("[pmc,%d] Null pm %p or pp %p", __LINE__, pm, pp));
807 KASSERT(PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)),
808 ("[pmc,%d] Attaching a non-process-virtual pmc=%p to pid=%d",
809 __LINE__, pm, pp->pp_proc->p_pid));
810 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= ((int) md->pmd_npmc - 1),
811 ("[pmc,%d] Illegal reference count %d for process record %p",
812 __LINE__, pp->pp_refcnt, (void *) pp));
813
814 ri = PMC_TO_ROWINDEX(pm);
815
816 PMCDBG3(PRC,TLK,1, "link-target pmc=%p ri=%d pmc-process=%p",
817 pm, ri, pp);
818
819 #ifdef HWPMC_DEBUG
820 LIST_FOREACH(pt, &pm->pm_targets, pt_next)
821 if (pt->pt_process == pp)
822 KASSERT(0, ("[pmc,%d] pp %p already in pmc %p targets",
823 __LINE__, pp, pm));
824 #endif
825
826 pt = malloc(sizeof(struct pmc_target), M_PMC, M_WAITOK|M_ZERO);
827 pt->pt_process = pp;
828
829 LIST_INSERT_HEAD(&pm->pm_targets, pt, pt_next);
830
831 atomic_store_rel_ptr((uintptr_t *)&pp->pp_pmcs[ri].pp_pmc,
832 (uintptr_t)pm);
833
834 if (pm->pm_owner->po_owner == pp->pp_proc)
835 pm->pm_flags |= PMC_F_ATTACHED_TO_OWNER;
836
837 /*
838 * Initialize the per-process values at this row index.
839 */
840 pp->pp_pmcs[ri].pp_pmcval = PMC_TO_MODE(pm) == PMC_MODE_TS ?
841 pm->pm_sc.pm_reloadcount : 0;
842
843 pp->pp_refcnt++;
844
845 }
846
847 /*
848 * Removes the association between a target process and a PMC.
849 */
850
851 static void
pmc_unlink_target_process(struct pmc * pm,struct pmc_process * pp)852 pmc_unlink_target_process(struct pmc *pm, struct pmc_process *pp)
853 {
854 int ri;
855 struct proc *p;
856 struct pmc_target *ptgt;
857
858 sx_assert(&pmc_sx, SX_XLOCKED);
859
860 KASSERT(pm != NULL && pp != NULL,
861 ("[pmc,%d] Null pm %p or pp %p", __LINE__, pm, pp));
862
863 KASSERT(pp->pp_refcnt >= 1 && pp->pp_refcnt <= (int) md->pmd_npmc,
864 ("[pmc,%d] Illegal ref count %d on process record %p",
865 __LINE__, pp->pp_refcnt, (void *) pp));
866
867 ri = PMC_TO_ROWINDEX(pm);
868
869 PMCDBG3(PRC,TUL,1, "unlink-target pmc=%p ri=%d pmc-process=%p",
870 pm, ri, pp);
871
872 KASSERT(pp->pp_pmcs[ri].pp_pmc == pm,
873 ("[pmc,%d] PMC ri %d mismatch pmc %p pp->[ri] %p", __LINE__,
874 ri, pm, pp->pp_pmcs[ri].pp_pmc));
875
876 pp->pp_pmcs[ri].pp_pmc = NULL;
877 pp->pp_pmcs[ri].pp_pmcval = (pmc_value_t) 0;
878
879 /* Remove owner-specific flags */
880 if (pm->pm_owner->po_owner == pp->pp_proc) {
881 pp->pp_flags &= ~PMC_PP_ENABLE_MSR_ACCESS;
882 pm->pm_flags &= ~PMC_F_ATTACHED_TO_OWNER;
883 }
884
885 pp->pp_refcnt--;
886
887 /* Remove the target process from the PMC structure */
888 LIST_FOREACH(ptgt, &pm->pm_targets, pt_next)
889 if (ptgt->pt_process == pp)
890 break;
891
892 KASSERT(ptgt != NULL, ("[pmc,%d] process %p (pp: %p) not found "
893 "in pmc %p", __LINE__, pp->pp_proc, pp, pm));
894
895 LIST_REMOVE(ptgt, pt_next);
896 free(ptgt, M_PMC);
897
898 /* if the PMC now lacks targets, send the owner a SIGIO */
899 if (LIST_EMPTY(&pm->pm_targets)) {
900 p = pm->pm_owner->po_owner;
901 PROC_LOCK(p);
902 kern_psignal(p, SIGIO);
903 PROC_UNLOCK(p);
904
905 PMCDBG2(PRC,SIG,2, "signalling proc=%p signal=%d", p,
906 SIGIO);
907 }
908 }
909
910 /*
911 * Check if PMC 'pm' may be attached to target process 't'.
912 */
913
914 static int
pmc_can_attach(struct pmc * pm,struct proc * t)915 pmc_can_attach(struct pmc *pm, struct proc *t)
916 {
917 struct proc *o; /* pmc owner */
918 struct ucred *oc, *tc; /* owner, target credentials */
919 int decline_attach, i;
920
921 /*
922 * A PMC's owner can always attach that PMC to itself.
923 */
924
925 if ((o = pm->pm_owner->po_owner) == t)
926 return 0;
927
928 PROC_LOCK(o);
929 oc = o->p_ucred;
930 crhold(oc);
931 PROC_UNLOCK(o);
932
933 PROC_LOCK(t);
934 tc = t->p_ucred;
935 crhold(tc);
936 PROC_UNLOCK(t);
937
938 /*
939 * The effective uid of the PMC owner should match at least one
940 * of the {effective,real,saved} uids of the target process.
941 */
942
943 decline_attach = oc->cr_uid != tc->cr_uid &&
944 oc->cr_uid != tc->cr_svuid &&
945 oc->cr_uid != tc->cr_ruid;
946
947 /*
948 * Every one of the target's group ids, must be in the owner's
949 * group list.
950 */
951 for (i = 0; !decline_attach && i < tc->cr_ngroups; i++)
952 decline_attach = !groupmember(tc->cr_groups[i], oc);
953
954 /* check the read and saved gids too */
955 if (decline_attach == 0)
956 decline_attach = !groupmember(tc->cr_rgid, oc) ||
957 !groupmember(tc->cr_svgid, oc);
958
959 crfree(tc);
960 crfree(oc);
961
962 return !decline_attach;
963 }
964
965 /*
966 * Attach a process to a PMC.
967 */
968
969 static int
pmc_attach_one_process(struct proc * p,struct pmc * pm)970 pmc_attach_one_process(struct proc *p, struct pmc *pm)
971 {
972 int ri;
973 char *fullpath, *freepath;
974 struct pmc_process *pp;
975
976 sx_assert(&pmc_sx, SX_XLOCKED);
977
978 PMCDBG5(PRC,ATT,2, "attach-one pm=%p ri=%d proc=%p (%d, %s)", pm,
979 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm);
980
981 /*
982 * Locate the process descriptor corresponding to process 'p',
983 * allocating space as needed.
984 *
985 * Verify that rowindex 'pm_rowindex' is free in the process
986 * descriptor.
987 *
988 * If not, allocate space for a descriptor and link the
989 * process descriptor and PMC.
990 */
991 ri = PMC_TO_ROWINDEX(pm);
992
993 if ((pp = pmc_find_process_descriptor(p, PMC_FLAG_ALLOCATE)) == NULL)
994 return ENOMEM;
995
996 if (pp->pp_pmcs[ri].pp_pmc == pm) /* already present at slot [ri] */
997 return EEXIST;
998
999 if (pp->pp_pmcs[ri].pp_pmc != NULL)
1000 return EBUSY;
1001
1002 pmc_link_target_process(pm, pp);
1003
1004 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)) &&
1005 (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) == 0)
1006 pm->pm_flags |= PMC_F_NEEDS_LOGFILE;
1007
1008 pm->pm_flags |= PMC_F_ATTACH_DONE; /* mark as attached */
1009
1010 /* issue an attach event to a configured log file */
1011 if (pm->pm_owner->po_flags & PMC_PO_OWNS_LOGFILE) {
1012 pmc_getfilename(p->p_textvp, &fullpath, &freepath);
1013 if (p->p_flag & P_KTHREAD) {
1014 fullpath = kernelname;
1015 freepath = NULL;
1016 } else
1017 pmclog_process_pmcattach(pm, p->p_pid, fullpath);
1018 if (freepath)
1019 free(freepath, M_TEMP);
1020 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)))
1021 pmc_log_process_mappings(pm->pm_owner, p);
1022 }
1023 /* mark process as using HWPMCs */
1024 PROC_LOCK(p);
1025 p->p_flag |= P_HWPMC;
1026 PROC_UNLOCK(p);
1027
1028 return 0;
1029 }
1030
1031 /*
1032 * Attach a process and optionally its children
1033 */
1034
1035 static int
pmc_attach_process(struct proc * p,struct pmc * pm)1036 pmc_attach_process(struct proc *p, struct pmc *pm)
1037 {
1038 int error;
1039 struct proc *top;
1040
1041 sx_assert(&pmc_sx, SX_XLOCKED);
1042
1043 PMCDBG5(PRC,ATT,1, "attach pm=%p ri=%d proc=%p (%d, %s)", pm,
1044 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm);
1045
1046
1047 /*
1048 * If this PMC successfully allowed a GETMSR operation
1049 * in the past, disallow further ATTACHes.
1050 */
1051
1052 if ((pm->pm_flags & PMC_PP_ENABLE_MSR_ACCESS) != 0)
1053 return EPERM;
1054
1055 if ((pm->pm_flags & PMC_F_DESCENDANTS) == 0)
1056 return pmc_attach_one_process(p, pm);
1057
1058 /*
1059 * Traverse all child processes, attaching them to
1060 * this PMC.
1061 */
1062
1063 sx_slock(&proctree_lock);
1064
1065 top = p;
1066
1067 for (;;) {
1068 if ((error = pmc_attach_one_process(p, pm)) != 0)
1069 break;
1070 if (!LIST_EMPTY(&p->p_children))
1071 p = LIST_FIRST(&p->p_children);
1072 else for (;;) {
1073 if (p == top)
1074 goto done;
1075 if (LIST_NEXT(p, p_sibling)) {
1076 p = LIST_NEXT(p, p_sibling);
1077 break;
1078 }
1079 p = p->p_pptr;
1080 }
1081 }
1082
1083 if (error)
1084 (void) pmc_detach_process(top, pm);
1085
1086 done:
1087 sx_sunlock(&proctree_lock);
1088 return error;
1089 }
1090
1091 /*
1092 * Detach a process from a PMC. If there are no other PMCs tracking
1093 * this process, remove the process structure from its hash table. If
1094 * 'flags' contains PMC_FLAG_REMOVE, then free the process structure.
1095 */
1096
1097 static int
pmc_detach_one_process(struct proc * p,struct pmc * pm,int flags)1098 pmc_detach_one_process(struct proc *p, struct pmc *pm, int flags)
1099 {
1100 int ri;
1101 struct pmc_process *pp;
1102
1103 sx_assert(&pmc_sx, SX_XLOCKED);
1104
1105 KASSERT(pm != NULL,
1106 ("[pmc,%d] null pm pointer", __LINE__));
1107
1108 ri = PMC_TO_ROWINDEX(pm);
1109
1110 PMCDBG6(PRC,ATT,2, "detach-one pm=%p ri=%d proc=%p (%d, %s) flags=0x%x",
1111 pm, ri, p, p->p_pid, p->p_comm, flags);
1112
1113 if ((pp = pmc_find_process_descriptor(p, 0)) == NULL)
1114 return ESRCH;
1115
1116 if (pp->pp_pmcs[ri].pp_pmc != pm)
1117 return EINVAL;
1118
1119 pmc_unlink_target_process(pm, pp);
1120
1121 /* Issue a detach entry if a log file is configured */
1122 if (pm->pm_owner->po_flags & PMC_PO_OWNS_LOGFILE)
1123 pmclog_process_pmcdetach(pm, p->p_pid);
1124
1125 /*
1126 * If there are no PMCs targetting this process, we remove its
1127 * descriptor from the target hash table and unset the P_HWPMC
1128 * flag in the struct proc.
1129 */
1130 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= (int) md->pmd_npmc,
1131 ("[pmc,%d] Illegal refcnt %d for process struct %p",
1132 __LINE__, pp->pp_refcnt, pp));
1133
1134 if (pp->pp_refcnt != 0) /* still a target of some PMC */
1135 return 0;
1136
1137 pmc_remove_process_descriptor(pp);
1138
1139 if (flags & PMC_FLAG_REMOVE)
1140 free(pp, M_PMC);
1141
1142 PROC_LOCK(p);
1143 p->p_flag &= ~P_HWPMC;
1144 PROC_UNLOCK(p);
1145
1146 return 0;
1147 }
1148
1149 /*
1150 * Detach a process and optionally its descendants from a PMC.
1151 */
1152
1153 static int
pmc_detach_process(struct proc * p,struct pmc * pm)1154 pmc_detach_process(struct proc *p, struct pmc *pm)
1155 {
1156 struct proc *top;
1157
1158 sx_assert(&pmc_sx, SX_XLOCKED);
1159
1160 PMCDBG5(PRC,ATT,1, "detach pm=%p ri=%d proc=%p (%d, %s)", pm,
1161 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm);
1162
1163 if ((pm->pm_flags & PMC_F_DESCENDANTS) == 0)
1164 return pmc_detach_one_process(p, pm, PMC_FLAG_REMOVE);
1165
1166 /*
1167 * Traverse all children, detaching them from this PMC. We
1168 * ignore errors since we could be detaching a PMC from a
1169 * partially attached proc tree.
1170 */
1171
1172 sx_slock(&proctree_lock);
1173
1174 top = p;
1175
1176 for (;;) {
1177 (void) pmc_detach_one_process(p, pm, PMC_FLAG_REMOVE);
1178
1179 if (!LIST_EMPTY(&p->p_children))
1180 p = LIST_FIRST(&p->p_children);
1181 else for (;;) {
1182 if (p == top)
1183 goto done;
1184 if (LIST_NEXT(p, p_sibling)) {
1185 p = LIST_NEXT(p, p_sibling);
1186 break;
1187 }
1188 p = p->p_pptr;
1189 }
1190 }
1191
1192 done:
1193 sx_sunlock(&proctree_lock);
1194
1195 if (LIST_EMPTY(&pm->pm_targets))
1196 pm->pm_flags &= ~PMC_F_ATTACH_DONE;
1197
1198 return 0;
1199 }
1200
1201
1202 /*
1203 * Thread context switch IN
1204 */
1205
1206 static void
pmc_process_csw_in(struct thread * td)1207 pmc_process_csw_in(struct thread *td)
1208 {
1209 int cpu;
1210 unsigned int adjri, ri;
1211 struct pmc *pm;
1212 struct proc *p;
1213 struct pmc_cpu *pc;
1214 struct pmc_hw *phw;
1215 pmc_value_t newvalue;
1216 struct pmc_process *pp;
1217 struct pmc_classdep *pcd;
1218
1219 p = td->td_proc;
1220
1221 if ((pp = pmc_find_process_descriptor(p, PMC_FLAG_NONE)) == NULL)
1222 return;
1223
1224 KASSERT(pp->pp_proc == td->td_proc,
1225 ("[pmc,%d] not my thread state", __LINE__));
1226
1227 critical_enter(); /* no preemption from this point */
1228
1229 cpu = PCPU_GET(cpuid); /* td->td_oncpu is invalid */
1230
1231 PMCDBG5(CSW,SWI,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p,
1232 p->p_pid, p->p_comm, pp);
1233
1234 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
1235 ("[pmc,%d] wierd CPU id %d", __LINE__, cpu));
1236
1237 pc = pmc_pcpu[cpu];
1238
1239 for (ri = 0; ri < md->pmd_npmc; ri++) {
1240
1241 if ((pm = pp->pp_pmcs[ri].pp_pmc) == NULL)
1242 continue;
1243
1244 KASSERT(PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)),
1245 ("[pmc,%d] Target PMC in non-virtual mode (%d)",
1246 __LINE__, PMC_TO_MODE(pm)));
1247
1248 KASSERT(PMC_TO_ROWINDEX(pm) == ri,
1249 ("[pmc,%d] Row index mismatch pmc %d != ri %d",
1250 __LINE__, PMC_TO_ROWINDEX(pm), ri));
1251
1252 /*
1253 * Only PMCs that are marked as 'RUNNING' need
1254 * be placed on hardware.
1255 */
1256
1257 if (pm->pm_state != PMC_STATE_RUNNING)
1258 continue;
1259
1260 /* increment PMC runcount */
1261 atomic_add_rel_int(&pm->pm_runcount, 1);
1262
1263 /* configure the HWPMC we are going to use. */
1264 pcd = pmc_ri_to_classdep(md, ri, &adjri);
1265 pcd->pcd_config_pmc(cpu, adjri, pm);
1266
1267 phw = pc->pc_hwpmcs[ri];
1268
1269 KASSERT(phw != NULL,
1270 ("[pmc,%d] null hw pointer", __LINE__));
1271
1272 KASSERT(phw->phw_pmc == pm,
1273 ("[pmc,%d] hw->pmc %p != pmc %p", __LINE__,
1274 phw->phw_pmc, pm));
1275
1276 /*
1277 * Write out saved value and start the PMC.
1278 *
1279 * Sampling PMCs use a per-process value, while
1280 * counting mode PMCs use a per-pmc value that is
1281 * inherited across descendants.
1282 */
1283 if (PMC_TO_MODE(pm) == PMC_MODE_TS) {
1284 mtx_pool_lock_spin(pmc_mtxpool, pm);
1285
1286 /*
1287 * Use the saved value calculated after the most recent
1288 * thread switch out to start this counter. Reset
1289 * the saved count in case another thread from this
1290 * process switches in before any threads switch out.
1291 */
1292 newvalue = PMC_PCPU_SAVED(cpu,ri) =
1293 pp->pp_pmcs[ri].pp_pmcval;
1294 pp->pp_pmcs[ri].pp_pmcval = pm->pm_sc.pm_reloadcount;
1295 mtx_pool_unlock_spin(pmc_mtxpool, pm);
1296 } else {
1297 KASSERT(PMC_TO_MODE(pm) == PMC_MODE_TC,
1298 ("[pmc,%d] illegal mode=%d", __LINE__,
1299 PMC_TO_MODE(pm)));
1300 mtx_pool_lock_spin(pmc_mtxpool, pm);
1301 newvalue = PMC_PCPU_SAVED(cpu, ri) =
1302 pm->pm_gv.pm_savedvalue;
1303 mtx_pool_unlock_spin(pmc_mtxpool, pm);
1304 }
1305
1306 PMCDBG3(CSW,SWI,1,"cpu=%d ri=%d new=%jd", cpu, ri, newvalue);
1307
1308 pcd->pcd_write_pmc(cpu, adjri, newvalue);
1309
1310 /* If a sampling mode PMC, reset stalled state. */
1311 if (PMC_TO_MODE(pm) == PMC_MODE_TS)
1312 CPU_CLR_ATOMIC(cpu, &pm->pm_stalled);
1313
1314 /* Indicate that we desire this to run. */
1315 CPU_SET_ATOMIC(cpu, &pm->pm_cpustate);
1316
1317 /* Start the PMC. */
1318 pcd->pcd_start_pmc(cpu, adjri);
1319 }
1320
1321 /*
1322 * perform any other architecture/cpu dependent thread
1323 * switch-in actions.
1324 */
1325
1326 (void) (*md->pmd_switch_in)(pc, pp);
1327
1328 critical_exit();
1329
1330 }
1331
1332 /*
1333 * Thread context switch OUT.
1334 */
1335
1336 static void
pmc_process_csw_out(struct thread * td)1337 pmc_process_csw_out(struct thread *td)
1338 {
1339 int cpu;
1340 int64_t tmp;
1341 struct pmc *pm;
1342 struct proc *p;
1343 enum pmc_mode mode;
1344 struct pmc_cpu *pc;
1345 pmc_value_t newvalue;
1346 unsigned int adjri, ri;
1347 struct pmc_process *pp;
1348 struct pmc_classdep *pcd;
1349
1350
1351 /*
1352 * Locate our process descriptor; this may be NULL if
1353 * this process is exiting and we have already removed
1354 * the process from the target process table.
1355 *
1356 * Note that due to kernel preemption, multiple
1357 * context switches may happen while the process is
1358 * exiting.
1359 *
1360 * Note also that if the target process cannot be
1361 * found we still need to deconfigure any PMCs that
1362 * are currently running on hardware.
1363 */
1364
1365 p = td->td_proc;
1366 pp = pmc_find_process_descriptor(p, PMC_FLAG_NONE);
1367
1368 /*
1369 * save PMCs
1370 */
1371
1372 critical_enter();
1373
1374 cpu = PCPU_GET(cpuid); /* td->td_oncpu is invalid */
1375
1376 PMCDBG5(CSW,SWO,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p,
1377 p->p_pid, p->p_comm, pp);
1378
1379 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
1380 ("[pmc,%d wierd CPU id %d", __LINE__, cpu));
1381
1382 pc = pmc_pcpu[cpu];
1383
1384 /*
1385 * When a PMC gets unlinked from a target PMC, it will
1386 * be removed from the target's pp_pmc[] array.
1387 *
1388 * However, on a MP system, the target could have been
1389 * executing on another CPU at the time of the unlink.
1390 * So, at context switch OUT time, we need to look at
1391 * the hardware to determine if a PMC is scheduled on
1392 * it.
1393 */
1394
1395 for (ri = 0; ri < md->pmd_npmc; ri++) {
1396
1397 pcd = pmc_ri_to_classdep(md, ri, &adjri);
1398 pm = NULL;
1399 (void) (*pcd->pcd_get_config)(cpu, adjri, &pm);
1400
1401 if (pm == NULL) /* nothing at this row index */
1402 continue;
1403
1404 mode = PMC_TO_MODE(pm);
1405 if (!PMC_IS_VIRTUAL_MODE(mode))
1406 continue; /* not a process virtual PMC */
1407
1408 KASSERT(PMC_TO_ROWINDEX(pm) == ri,
1409 ("[pmc,%d] ri mismatch pmc(%d) ri(%d)",
1410 __LINE__, PMC_TO_ROWINDEX(pm), ri));
1411
1412 /*
1413 * Change desired state, and then stop if not stalled.
1414 * This two-step dance should avoid race conditions where
1415 * an interrupt re-enables the PMC after this code has
1416 * already checked the pm_stalled flag.
1417 */
1418 CPU_CLR_ATOMIC(cpu, &pm->pm_cpustate);
1419 if (!CPU_ISSET(cpu, &pm->pm_stalled))
1420 pcd->pcd_stop_pmc(cpu, adjri);
1421
1422 /* reduce this PMC's runcount */
1423 atomic_subtract_rel_int(&pm->pm_runcount, 1);
1424
1425 /*
1426 * If this PMC is associated with this process,
1427 * save the reading.
1428 */
1429
1430 if (pp != NULL && pp->pp_pmcs[ri].pp_pmc != NULL) {
1431
1432 KASSERT(pm == pp->pp_pmcs[ri].pp_pmc,
1433 ("[pmc,%d] pm %p != pp_pmcs[%d] %p", __LINE__,
1434 pm, ri, pp->pp_pmcs[ri].pp_pmc));
1435
1436 KASSERT(pp->pp_refcnt > 0,
1437 ("[pmc,%d] pp refcnt = %d", __LINE__,
1438 pp->pp_refcnt));
1439
1440 pcd->pcd_read_pmc(cpu, adjri, &newvalue);
1441
1442 if (mode == PMC_MODE_TS) {
1443 PMCDBG3(CSW,SWO,1,"cpu=%d ri=%d tmp=%jd (samp)",
1444 cpu, ri, PMC_PCPU_SAVED(cpu,ri) - newvalue);
1445
1446 /*
1447 * For sampling process-virtual PMCs,
1448 * newvalue is the number of events to be seen
1449 * until the next sampling interrupt.
1450 * We can just add the events left from this
1451 * invocation to the counter, then adjust
1452 * in case we overflow our range.
1453 *
1454 * (Recall that we reload the counter every
1455 * time we use it.)
1456 */
1457 mtx_pool_lock_spin(pmc_mtxpool, pm);
1458
1459 pp->pp_pmcs[ri].pp_pmcval += newvalue;
1460 if (pp->pp_pmcs[ri].pp_pmcval >
1461 pm->pm_sc.pm_reloadcount)
1462 pp->pp_pmcs[ri].pp_pmcval -=
1463 pm->pm_sc.pm_reloadcount;
1464 KASSERT(pp->pp_pmcs[ri].pp_pmcval > 0 &&
1465 pp->pp_pmcs[ri].pp_pmcval <=
1466 pm->pm_sc.pm_reloadcount,
1467 ("[pmc,%d] pp_pmcval outside of expected "
1468 "range cpu=%d ri=%d pp_pmcval=%jx "
1469 "pm_reloadcount=%jx", __LINE__, cpu, ri,
1470 pp->pp_pmcs[ri].pp_pmcval,
1471 pm->pm_sc.pm_reloadcount));
1472 mtx_pool_unlock_spin(pmc_mtxpool, pm);
1473
1474 } else {
1475 tmp = newvalue - PMC_PCPU_SAVED(cpu,ri);
1476
1477 PMCDBG3(CSW,SWO,1,"cpu=%d ri=%d tmp=%jd (count)",
1478 cpu, ri, tmp);
1479
1480 /*
1481 * For counting process-virtual PMCs,
1482 * we expect the count to be
1483 * increasing monotonically, modulo a 64
1484 * bit wraparound.
1485 */
1486 KASSERT((int64_t) tmp >= 0,
1487 ("[pmc,%d] negative increment cpu=%d "
1488 "ri=%d newvalue=%jx saved=%jx "
1489 "incr=%jx", __LINE__, cpu, ri,
1490 newvalue, PMC_PCPU_SAVED(cpu,ri), tmp));
1491
1492 mtx_pool_lock_spin(pmc_mtxpool, pm);
1493 pm->pm_gv.pm_savedvalue += tmp;
1494 pp->pp_pmcs[ri].pp_pmcval += tmp;
1495 mtx_pool_unlock_spin(pmc_mtxpool, pm);
1496
1497 if (pm->pm_flags & PMC_F_LOG_PROCCSW)
1498 pmclog_process_proccsw(pm, pp, tmp);
1499 }
1500 }
1501
1502 /* mark hardware as free */
1503 pcd->pcd_config_pmc(cpu, adjri, NULL);
1504 }
1505
1506 /*
1507 * perform any other architecture/cpu dependent thread
1508 * switch out functions.
1509 */
1510
1511 (void) (*md->pmd_switch_out)(pc, pp);
1512
1513 critical_exit();
1514 }
1515
1516 /*
1517 * A mapping change for a process.
1518 */
1519
1520 static void
pmc_process_mmap(struct thread * td,struct pmckern_map_in * pkm)1521 pmc_process_mmap(struct thread *td, struct pmckern_map_in *pkm)
1522 {
1523 int ri;
1524 pid_t pid;
1525 char *fullpath, *freepath;
1526 const struct pmc *pm;
1527 struct pmc_owner *po;
1528 const struct pmc_process *pp;
1529
1530 freepath = fullpath = NULL;
1531 pmc_getfilename((struct vnode *) pkm->pm_file, &fullpath, &freepath);
1532
1533 pid = td->td_proc->p_pid;
1534
1535 /* Inform owners of all system-wide sampling PMCs. */
1536 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext)
1537 if (po->po_flags & PMC_PO_OWNS_LOGFILE)
1538 pmclog_process_map_in(po, pid, pkm->pm_address, fullpath);
1539
1540 if ((pp = pmc_find_process_descriptor(td->td_proc, 0)) == NULL)
1541 goto done;
1542
1543 /*
1544 * Inform sampling PMC owners tracking this process.
1545 */
1546 for (ri = 0; ri < md->pmd_npmc; ri++)
1547 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL &&
1548 PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)))
1549 pmclog_process_map_in(pm->pm_owner,
1550 pid, pkm->pm_address, fullpath);
1551
1552 done:
1553 if (freepath)
1554 free(freepath, M_TEMP);
1555 }
1556
1557
1558 /*
1559 * Log an munmap request.
1560 */
1561
1562 static void
pmc_process_munmap(struct thread * td,struct pmckern_map_out * pkm)1563 pmc_process_munmap(struct thread *td, struct pmckern_map_out *pkm)
1564 {
1565 int ri;
1566 pid_t pid;
1567 struct pmc_owner *po;
1568 const struct pmc *pm;
1569 const struct pmc_process *pp;
1570
1571 pid = td->td_proc->p_pid;
1572
1573 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext)
1574 if (po->po_flags & PMC_PO_OWNS_LOGFILE)
1575 pmclog_process_map_out(po, pid, pkm->pm_address,
1576 pkm->pm_address + pkm->pm_size);
1577
1578 if ((pp = pmc_find_process_descriptor(td->td_proc, 0)) == NULL)
1579 return;
1580
1581 for (ri = 0; ri < md->pmd_npmc; ri++)
1582 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL &&
1583 PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)))
1584 pmclog_process_map_out(pm->pm_owner, pid,
1585 pkm->pm_address, pkm->pm_address + pkm->pm_size);
1586 }
1587
1588 /*
1589 * Log mapping information about the kernel.
1590 */
1591
1592 static void
pmc_log_kernel_mappings(struct pmc * pm)1593 pmc_log_kernel_mappings(struct pmc *pm)
1594 {
1595 struct pmc_owner *po;
1596 struct pmckern_map_in *km, *kmbase;
1597
1598 sx_assert(&pmc_sx, SX_LOCKED);
1599 KASSERT(PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)),
1600 ("[pmc,%d] non-sampling PMC (%p) desires mapping information",
1601 __LINE__, (void *) pm));
1602
1603 po = pm->pm_owner;
1604
1605 if (po->po_flags & PMC_PO_INITIAL_MAPPINGS_DONE)
1606 return;
1607
1608 /*
1609 * Log the current set of kernel modules.
1610 */
1611 kmbase = linker_hwpmc_list_objects();
1612 for (km = kmbase; km->pm_file != NULL; km++) {
1613 PMCDBG2(LOG,REG,1,"%s %p", (char *) km->pm_file,
1614 (void *) km->pm_address);
1615 pmclog_process_map_in(po, (pid_t) -1, km->pm_address,
1616 km->pm_file);
1617 }
1618 free(kmbase, M_LINKER);
1619
1620 po->po_flags |= PMC_PO_INITIAL_MAPPINGS_DONE;
1621 }
1622
1623 /*
1624 * Log the mappings for a single process.
1625 */
1626
1627 static void
pmc_log_process_mappings(struct pmc_owner * po,struct proc * p)1628 pmc_log_process_mappings(struct pmc_owner *po, struct proc *p)
1629 {
1630 vm_map_t map;
1631 struct vnode *vp;
1632 struct vmspace *vm;
1633 vm_map_entry_t entry;
1634 vm_offset_t last_end;
1635 u_int last_timestamp;
1636 struct vnode *last_vp;
1637 vm_offset_t start_addr;
1638 vm_object_t obj, lobj, tobj;
1639 char *fullpath, *freepath;
1640
1641 last_vp = NULL;
1642 last_end = (vm_offset_t) 0;
1643 fullpath = freepath = NULL;
1644
1645 if ((vm = vmspace_acquire_ref(p)) == NULL)
1646 return;
1647
1648 map = &vm->vm_map;
1649 vm_map_lock_read(map);
1650
1651 for (entry = map->header.next; entry != &map->header; entry = entry->next) {
1652
1653 if (entry == NULL) {
1654 PMCDBG2(LOG,OPS,2, "hwpmc: vm_map entry unexpectedly "
1655 "NULL! pid=%d vm_map=%p\n", p->p_pid, map);
1656 break;
1657 }
1658
1659 /*
1660 * We only care about executable map entries.
1661 */
1662 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) ||
1663 !(entry->protection & VM_PROT_EXECUTE) ||
1664 (entry->object.vm_object == NULL)) {
1665 continue;
1666 }
1667
1668 obj = entry->object.vm_object;
1669 VM_OBJECT_RLOCK(obj);
1670
1671 /*
1672 * Walk the backing_object list to find the base
1673 * (non-shadowed) vm_object.
1674 */
1675 for (lobj = tobj = obj; tobj != NULL; tobj = tobj->backing_object) {
1676 if (tobj != obj)
1677 VM_OBJECT_RLOCK(tobj);
1678 if (lobj != obj)
1679 VM_OBJECT_RUNLOCK(lobj);
1680 lobj = tobj;
1681 }
1682
1683 /*
1684 * At this point lobj is the base vm_object and it is locked.
1685 */
1686 if (lobj == NULL) {
1687 PMCDBG3(LOG,OPS,2, "hwpmc: lobj unexpectedly NULL! pid=%d "
1688 "vm_map=%p vm_obj=%p\n", p->p_pid, map, obj);
1689 VM_OBJECT_RUNLOCK(obj);
1690 continue;
1691 }
1692
1693 vp = vm_object_vnode(lobj);
1694 if (vp == NULL) {
1695 if (lobj != obj)
1696 VM_OBJECT_RUNLOCK(lobj);
1697 VM_OBJECT_RUNLOCK(obj);
1698 continue;
1699 }
1700
1701 /*
1702 * Skip contiguous regions that point to the same
1703 * vnode, so we don't emit redundant MAP-IN
1704 * directives.
1705 */
1706 if (entry->start == last_end && vp == last_vp) {
1707 last_end = entry->end;
1708 if (lobj != obj)
1709 VM_OBJECT_RUNLOCK(lobj);
1710 VM_OBJECT_RUNLOCK(obj);
1711 continue;
1712 }
1713
1714 /*
1715 * We don't want to keep the proc's vm_map or this
1716 * vm_object locked while we walk the pathname, since
1717 * vn_fullpath() can sleep. However, if we drop the
1718 * lock, it's possible for concurrent activity to
1719 * modify the vm_map list. To protect against this,
1720 * we save the vm_map timestamp before we release the
1721 * lock, and check it after we reacquire the lock
1722 * below.
1723 */
1724 start_addr = entry->start;
1725 last_end = entry->end;
1726 last_timestamp = map->timestamp;
1727 vm_map_unlock_read(map);
1728
1729 vref(vp);
1730 if (lobj != obj)
1731 VM_OBJECT_RUNLOCK(lobj);
1732
1733 VM_OBJECT_RUNLOCK(obj);
1734
1735 freepath = NULL;
1736 pmc_getfilename(vp, &fullpath, &freepath);
1737 last_vp = vp;
1738
1739 vrele(vp);
1740
1741 vp = NULL;
1742 pmclog_process_map_in(po, p->p_pid, start_addr, fullpath);
1743 if (freepath)
1744 free(freepath, M_TEMP);
1745
1746 vm_map_lock_read(map);
1747
1748 /*
1749 * If our saved timestamp doesn't match, this means
1750 * that the vm_map was modified out from under us and
1751 * we can't trust our current "entry" pointer. Do a
1752 * new lookup for this entry. If there is no entry
1753 * for this address range, vm_map_lookup_entry() will
1754 * return the previous one, so we always want to go to
1755 * entry->next on the next loop iteration.
1756 *
1757 * There is an edge condition here that can occur if
1758 * there is no entry at or before this address. In
1759 * this situation, vm_map_lookup_entry returns
1760 * &map->header, which would cause our loop to abort
1761 * without processing the rest of the map. However,
1762 * in practice this will never happen for process
1763 * vm_map. This is because the executable's text
1764 * segment is the first mapping in the proc's address
1765 * space, and this mapping is never removed until the
1766 * process exits, so there will always be a non-header
1767 * entry at or before the requested address for
1768 * vm_map_lookup_entry to return.
1769 */
1770 if (map->timestamp != last_timestamp)
1771 vm_map_lookup_entry(map, last_end - 1, &entry);
1772 }
1773
1774 vm_map_unlock_read(map);
1775 vmspace_free(vm);
1776 return;
1777 }
1778
1779 /*
1780 * Log mappings for all processes in the system.
1781 */
1782
1783 static void
pmc_log_all_process_mappings(struct pmc_owner * po)1784 pmc_log_all_process_mappings(struct pmc_owner *po)
1785 {
1786 struct proc *p, *top;
1787
1788 sx_assert(&pmc_sx, SX_XLOCKED);
1789
1790 if ((p = pfind(1)) == NULL)
1791 panic("[pmc,%d] Cannot find init", __LINE__);
1792
1793 PROC_UNLOCK(p);
1794
1795 sx_slock(&proctree_lock);
1796
1797 top = p;
1798
1799 for (;;) {
1800 pmc_log_process_mappings(po, p);
1801 if (!LIST_EMPTY(&p->p_children))
1802 p = LIST_FIRST(&p->p_children);
1803 else for (;;) {
1804 if (p == top)
1805 goto done;
1806 if (LIST_NEXT(p, p_sibling)) {
1807 p = LIST_NEXT(p, p_sibling);
1808 break;
1809 }
1810 p = p->p_pptr;
1811 }
1812 }
1813 done:
1814 sx_sunlock(&proctree_lock);
1815 }
1816
1817 /*
1818 * The 'hook' invoked from the kernel proper
1819 */
1820
1821
1822 #ifdef HWPMC_DEBUG
1823 const char *pmc_hooknames[] = {
1824 /* these strings correspond to PMC_FN_* in <sys/pmckern.h> */
1825 "",
1826 "EXEC",
1827 "CSW-IN",
1828 "CSW-OUT",
1829 "SAMPLE",
1830 "UNUSED1",
1831 "UNUSED2",
1832 "MMAP",
1833 "MUNMAP",
1834 "CALLCHAIN-NMI",
1835 "CALLCHAIN-SOFT",
1836 "SOFTSAMPLING"
1837 };
1838 #endif
1839
1840 static int
pmc_hook_handler(struct thread * td,int function,void * arg)1841 pmc_hook_handler(struct thread *td, int function, void *arg)
1842 {
1843
1844 PMCDBG4(MOD,PMH,1, "hook td=%p func=%d \"%s\" arg=%p", td, function,
1845 pmc_hooknames[function], arg);
1846
1847 switch (function)
1848 {
1849
1850 /*
1851 * Process exec()
1852 */
1853
1854 case PMC_FN_PROCESS_EXEC:
1855 {
1856 char *fullpath, *freepath;
1857 unsigned int ri;
1858 int is_using_hwpmcs;
1859 struct pmc *pm;
1860 struct proc *p;
1861 struct pmc_owner *po;
1862 struct pmc_process *pp;
1863 struct pmckern_procexec *pk;
1864
1865 sx_assert(&pmc_sx, SX_XLOCKED);
1866
1867 p = td->td_proc;
1868 pmc_getfilename(p->p_textvp, &fullpath, &freepath);
1869
1870 pk = (struct pmckern_procexec *) arg;
1871
1872 /* Inform owners of SS mode PMCs of the exec event. */
1873 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext)
1874 if (po->po_flags & PMC_PO_OWNS_LOGFILE)
1875 pmclog_process_procexec(po, PMC_ID_INVALID,
1876 p->p_pid, pk->pm_entryaddr, fullpath);
1877
1878 PROC_LOCK(p);
1879 is_using_hwpmcs = p->p_flag & P_HWPMC;
1880 PROC_UNLOCK(p);
1881
1882 if (!is_using_hwpmcs) {
1883 if (freepath)
1884 free(freepath, M_TEMP);
1885 break;
1886 }
1887
1888 /*
1889 * PMCs are not inherited across an exec(): remove any
1890 * PMCs that this process is the owner of.
1891 */
1892
1893 if ((po = pmc_find_owner_descriptor(p)) != NULL) {
1894 pmc_remove_owner(po);
1895 pmc_destroy_owner_descriptor(po);
1896 }
1897
1898 /*
1899 * If the process being exec'ed is not the target of any
1900 * PMC, we are done.
1901 */
1902 if ((pp = pmc_find_process_descriptor(p, 0)) == NULL) {
1903 if (freepath)
1904 free(freepath, M_TEMP);
1905 break;
1906 }
1907
1908 /*
1909 * Log the exec event to all monitoring owners. Skip
1910 * owners who have already recieved the event because
1911 * they had system sampling PMCs active.
1912 */
1913 for (ri = 0; ri < md->pmd_npmc; ri++)
1914 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) {
1915 po = pm->pm_owner;
1916 if (po->po_sscount == 0 &&
1917 po->po_flags & PMC_PO_OWNS_LOGFILE)
1918 pmclog_process_procexec(po, pm->pm_id,
1919 p->p_pid, pk->pm_entryaddr,
1920 fullpath);
1921 }
1922
1923 if (freepath)
1924 free(freepath, M_TEMP);
1925
1926
1927 PMCDBG4(PRC,EXC,1, "exec proc=%p (%d, %s) cred-changed=%d",
1928 p, p->p_pid, p->p_comm, pk->pm_credentialschanged);
1929
1930 if (pk->pm_credentialschanged == 0) /* no change */
1931 break;
1932
1933 /*
1934 * If the newly exec()'ed process has a different credential
1935 * than before, allow it to be the target of a PMC only if
1936 * the PMC's owner has sufficient priviledge.
1937 */
1938
1939 for (ri = 0; ri < md->pmd_npmc; ri++)
1940 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL)
1941 if (pmc_can_attach(pm, td->td_proc) != 0)
1942 pmc_detach_one_process(td->td_proc,
1943 pm, PMC_FLAG_NONE);
1944
1945 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= (int) md->pmd_npmc,
1946 ("[pmc,%d] Illegal ref count %d on pp %p", __LINE__,
1947 pp->pp_refcnt, pp));
1948
1949 /*
1950 * If this process is no longer the target of any
1951 * PMCs, we can remove the process entry and free
1952 * up space.
1953 */
1954
1955 if (pp->pp_refcnt == 0) {
1956 pmc_remove_process_descriptor(pp);
1957 free(pp, M_PMC);
1958 break;
1959 }
1960
1961 }
1962 break;
1963
1964 case PMC_FN_CSW_IN:
1965 pmc_process_csw_in(td);
1966 break;
1967
1968 case PMC_FN_CSW_OUT:
1969 pmc_process_csw_out(td);
1970 break;
1971
1972 /*
1973 * Process accumulated PC samples.
1974 *
1975 * This function is expected to be called by hardclock() for
1976 * each CPU that has accumulated PC samples.
1977 *
1978 * This function is to be executed on the CPU whose samples
1979 * are being processed.
1980 */
1981 case PMC_FN_DO_SAMPLES:
1982
1983 /*
1984 * Clear the cpu specific bit in the CPU mask before
1985 * do the rest of the processing. If the NMI handler
1986 * gets invoked after the "atomic_clear_int()" call
1987 * below but before "pmc_process_samples()" gets
1988 * around to processing the interrupt, then we will
1989 * come back here at the next hardclock() tick (and
1990 * may find nothing to do if "pmc_process_samples()"
1991 * had already processed the interrupt). We don't
1992 * lose the interrupt sample.
1993 */
1994 CPU_CLR_ATOMIC(PCPU_GET(cpuid), &pmc_cpumask);
1995 pmc_process_samples(PCPU_GET(cpuid), PMC_HR);
1996 pmc_process_samples(PCPU_GET(cpuid), PMC_SR);
1997 break;
1998
1999 case PMC_FN_MMAP:
2000 sx_assert(&pmc_sx, SX_LOCKED);
2001 pmc_process_mmap(td, (struct pmckern_map_in *) arg);
2002 break;
2003
2004 case PMC_FN_MUNMAP:
2005 sx_assert(&pmc_sx, SX_LOCKED);
2006 pmc_process_munmap(td, (struct pmckern_map_out *) arg);
2007 break;
2008
2009 case PMC_FN_USER_CALLCHAIN:
2010 /*
2011 * Record a call chain.
2012 */
2013 KASSERT(td == curthread, ("[pmc,%d] td != curthread",
2014 __LINE__));
2015
2016 pmc_capture_user_callchain(PCPU_GET(cpuid), PMC_HR,
2017 (struct trapframe *) arg);
2018 td->td_pflags &= ~TDP_CALLCHAIN;
2019 break;
2020
2021 case PMC_FN_USER_CALLCHAIN_SOFT:
2022 /*
2023 * Record a call chain.
2024 */
2025 KASSERT(td == curthread, ("[pmc,%d] td != curthread",
2026 __LINE__));
2027 pmc_capture_user_callchain(PCPU_GET(cpuid), PMC_SR,
2028 (struct trapframe *) arg);
2029 td->td_pflags &= ~TDP_CALLCHAIN;
2030 break;
2031
2032 case PMC_FN_SOFT_SAMPLING:
2033 /*
2034 * Call soft PMC sampling intr.
2035 */
2036 pmc_soft_intr((struct pmckern_soft *) arg);
2037 break;
2038
2039 default:
2040 #ifdef HWPMC_DEBUG
2041 KASSERT(0, ("[pmc,%d] unknown hook %d\n", __LINE__, function));
2042 #endif
2043 break;
2044
2045 }
2046
2047 return 0;
2048 }
2049
2050 /*
2051 * allocate a 'struct pmc_owner' descriptor in the owner hash table.
2052 */
2053
2054 static struct pmc_owner *
pmc_allocate_owner_descriptor(struct proc * p)2055 pmc_allocate_owner_descriptor(struct proc *p)
2056 {
2057 uint32_t hindex;
2058 struct pmc_owner *po;
2059 struct pmc_ownerhash *poh;
2060
2061 hindex = PMC_HASH_PTR(p, pmc_ownerhashmask);
2062 poh = &pmc_ownerhash[hindex];
2063
2064 /* allocate space for N pointers and one descriptor struct */
2065 po = malloc(sizeof(struct pmc_owner), M_PMC, M_WAITOK|M_ZERO);
2066 po->po_owner = p;
2067 LIST_INSERT_HEAD(poh, po, po_next); /* insert into hash table */
2068
2069 TAILQ_INIT(&po->po_logbuffers);
2070 mtx_init(&po->po_mtx, "pmc-owner-mtx", "pmc-per-proc", MTX_SPIN);
2071
2072 PMCDBG4(OWN,ALL,1, "allocate-owner proc=%p (%d, %s) pmc-owner=%p",
2073 p, p->p_pid, p->p_comm, po);
2074
2075 return po;
2076 }
2077
2078 static void
pmc_destroy_owner_descriptor(struct pmc_owner * po)2079 pmc_destroy_owner_descriptor(struct pmc_owner *po)
2080 {
2081
2082 PMCDBG4(OWN,REL,1, "destroy-owner po=%p proc=%p (%d, %s)",
2083 po, po->po_owner, po->po_owner->p_pid, po->po_owner->p_comm);
2084
2085 mtx_destroy(&po->po_mtx);
2086 free(po, M_PMC);
2087 }
2088
2089 /*
2090 * find the descriptor corresponding to process 'p', adding or removing it
2091 * as specified by 'mode'.
2092 */
2093
2094 static struct pmc_process *
pmc_find_process_descriptor(struct proc * p,uint32_t mode)2095 pmc_find_process_descriptor(struct proc *p, uint32_t mode)
2096 {
2097 uint32_t hindex;
2098 struct pmc_process *pp, *ppnew;
2099 struct pmc_processhash *pph;
2100
2101 hindex = PMC_HASH_PTR(p, pmc_processhashmask);
2102 pph = &pmc_processhash[hindex];
2103
2104 ppnew = NULL;
2105
2106 /*
2107 * Pre-allocate memory in the FIND_ALLOCATE case since we
2108 * cannot call malloc(9) once we hold a spin lock.
2109 */
2110 if (mode & PMC_FLAG_ALLOCATE)
2111 ppnew = malloc(sizeof(struct pmc_process) + md->pmd_npmc *
2112 sizeof(struct pmc_targetstate), M_PMC, M_WAITOK|M_ZERO);
2113
2114 mtx_lock_spin(&pmc_processhash_mtx);
2115 LIST_FOREACH(pp, pph, pp_next)
2116 if (pp->pp_proc == p)
2117 break;
2118
2119 if ((mode & PMC_FLAG_REMOVE) && pp != NULL)
2120 LIST_REMOVE(pp, pp_next);
2121
2122 if ((mode & PMC_FLAG_ALLOCATE) && pp == NULL &&
2123 ppnew != NULL) {
2124 ppnew->pp_proc = p;
2125 LIST_INSERT_HEAD(pph, ppnew, pp_next);
2126 pp = ppnew;
2127 ppnew = NULL;
2128 }
2129 mtx_unlock_spin(&pmc_processhash_mtx);
2130
2131 if (pp != NULL && ppnew != NULL)
2132 free(ppnew, M_PMC);
2133
2134 return pp;
2135 }
2136
2137 /*
2138 * remove a process descriptor from the process hash table.
2139 */
2140
2141 static void
pmc_remove_process_descriptor(struct pmc_process * pp)2142 pmc_remove_process_descriptor(struct pmc_process *pp)
2143 {
2144 KASSERT(pp->pp_refcnt == 0,
2145 ("[pmc,%d] Removing process descriptor %p with count %d",
2146 __LINE__, pp, pp->pp_refcnt));
2147
2148 mtx_lock_spin(&pmc_processhash_mtx);
2149 LIST_REMOVE(pp, pp_next);
2150 mtx_unlock_spin(&pmc_processhash_mtx);
2151 }
2152
2153
2154 /*
2155 * find an owner descriptor corresponding to proc 'p'
2156 */
2157
2158 static struct pmc_owner *
pmc_find_owner_descriptor(struct proc * p)2159 pmc_find_owner_descriptor(struct proc *p)
2160 {
2161 uint32_t hindex;
2162 struct pmc_owner *po;
2163 struct pmc_ownerhash *poh;
2164
2165 hindex = PMC_HASH_PTR(p, pmc_ownerhashmask);
2166 poh = &pmc_ownerhash[hindex];
2167
2168 po = NULL;
2169 LIST_FOREACH(po, poh, po_next)
2170 if (po->po_owner == p)
2171 break;
2172
2173 PMCDBG5(OWN,FND,1, "find-owner proc=%p (%d, %s) hindex=0x%x -> "
2174 "pmc-owner=%p", p, p->p_pid, p->p_comm, hindex, po);
2175
2176 return po;
2177 }
2178
2179 /*
2180 * pmc_allocate_pmc_descriptor
2181 *
2182 * Allocate a pmc descriptor and initialize its
2183 * fields.
2184 */
2185
2186 static struct pmc *
pmc_allocate_pmc_descriptor(void)2187 pmc_allocate_pmc_descriptor(void)
2188 {
2189 struct pmc *pmc;
2190
2191 pmc = malloc(sizeof(struct pmc), M_PMC, M_WAITOK|M_ZERO);
2192
2193 PMCDBG1(PMC,ALL,1, "allocate-pmc -> pmc=%p", pmc);
2194
2195 return pmc;
2196 }
2197
2198 /*
2199 * Destroy a pmc descriptor.
2200 */
2201
2202 static void
pmc_destroy_pmc_descriptor(struct pmc * pm)2203 pmc_destroy_pmc_descriptor(struct pmc *pm)
2204 {
2205
2206 KASSERT(pm->pm_state == PMC_STATE_DELETED ||
2207 pm->pm_state == PMC_STATE_FREE,
2208 ("[pmc,%d] destroying non-deleted PMC", __LINE__));
2209 KASSERT(LIST_EMPTY(&pm->pm_targets),
2210 ("[pmc,%d] destroying pmc with targets", __LINE__));
2211 KASSERT(pm->pm_owner == NULL,
2212 ("[pmc,%d] destroying pmc attached to an owner", __LINE__));
2213 KASSERT(pm->pm_runcount == 0,
2214 ("[pmc,%d] pmc has non-zero run count %d", __LINE__,
2215 pm->pm_runcount));
2216
2217 free(pm, M_PMC);
2218 }
2219
2220 static void
pmc_wait_for_pmc_idle(struct pmc * pm)2221 pmc_wait_for_pmc_idle(struct pmc *pm)
2222 {
2223 #ifdef HWPMC_DEBUG
2224 volatile int maxloop;
2225
2226 maxloop = 100 * pmc_cpu_max();
2227 #endif
2228 /*
2229 * Loop (with a forced context switch) till the PMC's runcount
2230 * comes down to zero.
2231 */
2232 while (atomic_load_acq_32(&pm->pm_runcount) > 0) {
2233 #ifdef HWPMC_DEBUG
2234 maxloop--;
2235 KASSERT(maxloop > 0,
2236 ("[pmc,%d] (ri%d, rc%d) waiting too long for "
2237 "pmc to be free", __LINE__,
2238 PMC_TO_ROWINDEX(pm), pm->pm_runcount));
2239 #endif
2240 pmc_force_context_switch();
2241 }
2242 }
2243
2244 /*
2245 * This function does the following things:
2246 *
2247 * - detaches the PMC from hardware
2248 * - unlinks all target threads that were attached to it
2249 * - removes the PMC from its owner's list
2250 * - destroys the PMC private mutex
2251 *
2252 * Once this function completes, the given pmc pointer can be freed by
2253 * calling pmc_destroy_pmc_descriptor().
2254 */
2255
2256 static void
pmc_release_pmc_descriptor(struct pmc * pm)2257 pmc_release_pmc_descriptor(struct pmc *pm)
2258 {
2259 enum pmc_mode mode;
2260 struct pmc_hw *phw;
2261 u_int adjri, ri, cpu;
2262 struct pmc_owner *po;
2263 struct pmc_binding pb;
2264 struct pmc_process *pp;
2265 struct pmc_classdep *pcd;
2266 struct pmc_target *ptgt, *tmp;
2267
2268 sx_assert(&pmc_sx, SX_XLOCKED);
2269
2270 KASSERT(pm, ("[pmc,%d] null pmc", __LINE__));
2271
2272 ri = PMC_TO_ROWINDEX(pm);
2273 pcd = pmc_ri_to_classdep(md, ri, &adjri);
2274 mode = PMC_TO_MODE(pm);
2275
2276 PMCDBG3(PMC,REL,1, "release-pmc pmc=%p ri=%d mode=%d", pm, ri,
2277 mode);
2278
2279 /*
2280 * First, we take the PMC off hardware.
2281 */
2282 cpu = 0;
2283 if (PMC_IS_SYSTEM_MODE(mode)) {
2284
2285 /*
2286 * A system mode PMC runs on a specific CPU. Switch
2287 * to this CPU and turn hardware off.
2288 */
2289 pmc_save_cpu_binding(&pb);
2290
2291 cpu = PMC_TO_CPU(pm);
2292
2293 pmc_select_cpu(cpu);
2294
2295 /* switch off non-stalled CPUs */
2296 CPU_CLR_ATOMIC(cpu, &pm->pm_cpustate);
2297 if (pm->pm_state == PMC_STATE_RUNNING &&
2298 !CPU_ISSET(cpu, &pm->pm_stalled)) {
2299
2300 phw = pmc_pcpu[cpu]->pc_hwpmcs[ri];
2301
2302 KASSERT(phw->phw_pmc == pm,
2303 ("[pmc, %d] pmc ptr ri(%d) hw(%p) pm(%p)",
2304 __LINE__, ri, phw->phw_pmc, pm));
2305 PMCDBG2(PMC,REL,2, "stopping cpu=%d ri=%d", cpu, ri);
2306
2307 critical_enter();
2308 pcd->pcd_stop_pmc(cpu, adjri);
2309 critical_exit();
2310 }
2311
2312 PMCDBG2(PMC,REL,2, "decfg cpu=%d ri=%d", cpu, ri);
2313
2314 critical_enter();
2315 pcd->pcd_config_pmc(cpu, adjri, NULL);
2316 critical_exit();
2317
2318 /* adjust the global and process count of SS mode PMCs */
2319 if (mode == PMC_MODE_SS && pm->pm_state == PMC_STATE_RUNNING) {
2320 po = pm->pm_owner;
2321 po->po_sscount--;
2322 if (po->po_sscount == 0) {
2323 atomic_subtract_rel_int(&pmc_ss_count, 1);
2324 LIST_REMOVE(po, po_ssnext);
2325 }
2326 }
2327
2328 pm->pm_state = PMC_STATE_DELETED;
2329
2330 pmc_restore_cpu_binding(&pb);
2331
2332 /*
2333 * We could have references to this PMC structure in
2334 * the per-cpu sample queues. Wait for the queue to
2335 * drain.
2336 */
2337 pmc_wait_for_pmc_idle(pm);
2338
2339 } else if (PMC_IS_VIRTUAL_MODE(mode)) {
2340
2341 /*
2342 * A virtual PMC could be running on multiple CPUs at
2343 * a given instant.
2344 *
2345 * By marking its state as DELETED, we ensure that
2346 * this PMC is never further scheduled on hardware.
2347 *
2348 * Then we wait till all CPUs are done with this PMC.
2349 */
2350 pm->pm_state = PMC_STATE_DELETED;
2351
2352
2353 /* Wait for the PMCs runcount to come to zero. */
2354 pmc_wait_for_pmc_idle(pm);
2355
2356 /*
2357 * At this point the PMC is off all CPUs and cannot be
2358 * freshly scheduled onto a CPU. It is now safe to
2359 * unlink all targets from this PMC. If a
2360 * process-record's refcount falls to zero, we remove
2361 * it from the hash table. The module-wide SX lock
2362 * protects us from races.
2363 */
2364 LIST_FOREACH_SAFE(ptgt, &pm->pm_targets, pt_next, tmp) {
2365 pp = ptgt->pt_process;
2366 pmc_unlink_target_process(pm, pp); /* frees 'ptgt' */
2367
2368 PMCDBG1(PMC,REL,3, "pp->refcnt=%d", pp->pp_refcnt);
2369
2370 /*
2371 * If the target process record shows that no
2372 * PMCs are attached to it, reclaim its space.
2373 */
2374
2375 if (pp->pp_refcnt == 0) {
2376 pmc_remove_process_descriptor(pp);
2377 free(pp, M_PMC);
2378 }
2379 }
2380
2381 cpu = curthread->td_oncpu; /* setup cpu for pmd_release() */
2382
2383 }
2384
2385 /*
2386 * Release any MD resources
2387 */
2388 (void) pcd->pcd_release_pmc(cpu, adjri, pm);
2389
2390 /*
2391 * Update row disposition
2392 */
2393
2394 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm)))
2395 PMC_UNMARK_ROW_STANDALONE(ri);
2396 else
2397 PMC_UNMARK_ROW_THREAD(ri);
2398
2399 /* unlink from the owner's list */
2400 if (pm->pm_owner) {
2401 LIST_REMOVE(pm, pm_next);
2402 pm->pm_owner = NULL;
2403 }
2404 }
2405
2406 /*
2407 * Register an owner and a pmc.
2408 */
2409
2410 static int
pmc_register_owner(struct proc * p,struct pmc * pmc)2411 pmc_register_owner(struct proc *p, struct pmc *pmc)
2412 {
2413 struct pmc_owner *po;
2414
2415 sx_assert(&pmc_sx, SX_XLOCKED);
2416
2417 if ((po = pmc_find_owner_descriptor(p)) == NULL)
2418 if ((po = pmc_allocate_owner_descriptor(p)) == NULL)
2419 return ENOMEM;
2420
2421 KASSERT(pmc->pm_owner == NULL,
2422 ("[pmc,%d] attempting to own an initialized PMC", __LINE__));
2423 pmc->pm_owner = po;
2424
2425 LIST_INSERT_HEAD(&po->po_pmcs, pmc, pm_next);
2426
2427 PROC_LOCK(p);
2428 p->p_flag |= P_HWPMC;
2429 PROC_UNLOCK(p);
2430
2431 if (po->po_flags & PMC_PO_OWNS_LOGFILE)
2432 pmclog_process_pmcallocate(pmc);
2433
2434 PMCDBG2(PMC,REG,1, "register-owner pmc-owner=%p pmc=%p",
2435 po, pmc);
2436
2437 return 0;
2438 }
2439
2440 /*
2441 * Return the current row disposition:
2442 * == 0 => FREE
2443 * > 0 => PROCESS MODE
2444 * < 0 => SYSTEM MODE
2445 */
2446
2447 int
pmc_getrowdisp(int ri)2448 pmc_getrowdisp(int ri)
2449 {
2450 return pmc_pmcdisp[ri];
2451 }
2452
2453 /*
2454 * Check if a PMC at row index 'ri' can be allocated to the current
2455 * process.
2456 *
2457 * Allocation can fail if:
2458 * - the current process is already being profiled by a PMC at index 'ri',
2459 * attached to it via OP_PMCATTACH.
2460 * - the current process has already allocated a PMC at index 'ri'
2461 * via OP_ALLOCATE.
2462 */
2463
2464 static int
pmc_can_allocate_rowindex(struct proc * p,unsigned int ri,int cpu)2465 pmc_can_allocate_rowindex(struct proc *p, unsigned int ri, int cpu)
2466 {
2467 enum pmc_mode mode;
2468 struct pmc *pm;
2469 struct pmc_owner *po;
2470 struct pmc_process *pp;
2471
2472 PMCDBG5(PMC,ALR,1, "can-allocate-rowindex proc=%p (%d, %s) ri=%d "
2473 "cpu=%d", p, p->p_pid, p->p_comm, ri, cpu);
2474
2475 /*
2476 * We shouldn't have already allocated a process-mode PMC at
2477 * row index 'ri'.
2478 *
2479 * We shouldn't have allocated a system-wide PMC on the same
2480 * CPU and same RI.
2481 */
2482 if ((po = pmc_find_owner_descriptor(p)) != NULL)
2483 LIST_FOREACH(pm, &po->po_pmcs, pm_next) {
2484 if (PMC_TO_ROWINDEX(pm) == ri) {
2485 mode = PMC_TO_MODE(pm);
2486 if (PMC_IS_VIRTUAL_MODE(mode))
2487 return EEXIST;
2488 if (PMC_IS_SYSTEM_MODE(mode) &&
2489 (int) PMC_TO_CPU(pm) == cpu)
2490 return EEXIST;
2491 }
2492 }
2493
2494 /*
2495 * We also shouldn't be the target of any PMC at this index
2496 * since otherwise a PMC_ATTACH to ourselves will fail.
2497 */
2498 if ((pp = pmc_find_process_descriptor(p, 0)) != NULL)
2499 if (pp->pp_pmcs[ri].pp_pmc)
2500 return EEXIST;
2501
2502 PMCDBG4(PMC,ALR,2, "can-allocate-rowindex proc=%p (%d, %s) ri=%d ok",
2503 p, p->p_pid, p->p_comm, ri);
2504
2505 return 0;
2506 }
2507
2508 /*
2509 * Check if a given PMC at row index 'ri' can be currently used in
2510 * mode 'mode'.
2511 */
2512
2513 static int
pmc_can_allocate_row(int ri,enum pmc_mode mode)2514 pmc_can_allocate_row(int ri, enum pmc_mode mode)
2515 {
2516 enum pmc_disp disp;
2517
2518 sx_assert(&pmc_sx, SX_XLOCKED);
2519
2520 PMCDBG2(PMC,ALR,1, "can-allocate-row ri=%d mode=%d", ri, mode);
2521
2522 if (PMC_IS_SYSTEM_MODE(mode))
2523 disp = PMC_DISP_STANDALONE;
2524 else
2525 disp = PMC_DISP_THREAD;
2526
2527 /*
2528 * check disposition for PMC row 'ri':
2529 *
2530 * Expected disposition Row-disposition Result
2531 *
2532 * STANDALONE STANDALONE or FREE proceed
2533 * STANDALONE THREAD fail
2534 * THREAD THREAD or FREE proceed
2535 * THREAD STANDALONE fail
2536 */
2537
2538 if (!PMC_ROW_DISP_IS_FREE(ri) &&
2539 !(disp == PMC_DISP_THREAD && PMC_ROW_DISP_IS_THREAD(ri)) &&
2540 !(disp == PMC_DISP_STANDALONE && PMC_ROW_DISP_IS_STANDALONE(ri)))
2541 return EBUSY;
2542
2543 /*
2544 * All OK
2545 */
2546
2547 PMCDBG2(PMC,ALR,2, "can-allocate-row ri=%d mode=%d ok", ri, mode);
2548
2549 return 0;
2550
2551 }
2552
2553 /*
2554 * Find a PMC descriptor with user handle 'pmcid' for thread 'td'.
2555 */
2556
2557 static struct pmc *
pmc_find_pmc_descriptor_in_process(struct pmc_owner * po,pmc_id_t pmcid)2558 pmc_find_pmc_descriptor_in_process(struct pmc_owner *po, pmc_id_t pmcid)
2559 {
2560 struct pmc *pm;
2561
2562 KASSERT(PMC_ID_TO_ROWINDEX(pmcid) < md->pmd_npmc,
2563 ("[pmc,%d] Illegal pmc index %d (max %d)", __LINE__,
2564 PMC_ID_TO_ROWINDEX(pmcid), md->pmd_npmc));
2565
2566 LIST_FOREACH(pm, &po->po_pmcs, pm_next)
2567 if (pm->pm_id == pmcid)
2568 return pm;
2569
2570 return NULL;
2571 }
2572
2573 static int
pmc_find_pmc(pmc_id_t pmcid,struct pmc ** pmc)2574 pmc_find_pmc(pmc_id_t pmcid, struct pmc **pmc)
2575 {
2576
2577 struct pmc *pm, *opm;
2578 struct pmc_owner *po;
2579 struct pmc_process *pp;
2580
2581 KASSERT(PMC_ID_TO_ROWINDEX(pmcid) < md->pmd_npmc,
2582 ("[pmc,%d] Illegal pmc index %d (max %d)", __LINE__,
2583 PMC_ID_TO_ROWINDEX(pmcid), md->pmd_npmc));
2584 PMCDBG1(PMC,FND,1, "find-pmc id=%d", pmcid);
2585
2586 if ((po = pmc_find_owner_descriptor(curthread->td_proc)) == NULL) {
2587 /*
2588 * In case of PMC_F_DESCENDANTS child processes we will not find
2589 * the current process in the owners hash list. Find the owner
2590 * process first and from there lookup the po.
2591 */
2592 if ((pp = pmc_find_process_descriptor(curthread->td_proc,
2593 PMC_FLAG_NONE)) == NULL) {
2594 return ESRCH;
2595 } else {
2596 opm = pp->pp_pmcs[PMC_ID_TO_ROWINDEX(pmcid)].pp_pmc;
2597 if (opm == NULL)
2598 return ESRCH;
2599 if ((opm->pm_flags & (PMC_F_ATTACHED_TO_OWNER|
2600 PMC_F_DESCENDANTS)) != (PMC_F_ATTACHED_TO_OWNER|
2601 PMC_F_DESCENDANTS))
2602 return ESRCH;
2603 po = opm->pm_owner;
2604 }
2605 }
2606
2607 if ((pm = pmc_find_pmc_descriptor_in_process(po, pmcid)) == NULL)
2608 return EINVAL;
2609
2610 PMCDBG2(PMC,FND,2, "find-pmc id=%d -> pmc=%p", pmcid, pm);
2611
2612 *pmc = pm;
2613 return 0;
2614 }
2615
2616 /*
2617 * Start a PMC.
2618 */
2619
2620 static int
pmc_start(struct pmc * pm)2621 pmc_start(struct pmc *pm)
2622 {
2623 enum pmc_mode mode;
2624 struct pmc_owner *po;
2625 struct pmc_binding pb;
2626 struct pmc_classdep *pcd;
2627 int adjri, error, cpu, ri;
2628
2629 KASSERT(pm != NULL,
2630 ("[pmc,%d] null pm", __LINE__));
2631
2632 mode = PMC_TO_MODE(pm);
2633 ri = PMC_TO_ROWINDEX(pm);
2634 pcd = pmc_ri_to_classdep(md, ri, &adjri);
2635
2636 error = 0;
2637
2638 PMCDBG3(PMC,OPS,1, "start pmc=%p mode=%d ri=%d", pm, mode, ri);
2639
2640 po = pm->pm_owner;
2641
2642 /*
2643 * Disallow PMCSTART if a logfile is required but has not been
2644 * configured yet.
2645 */
2646 if ((pm->pm_flags & PMC_F_NEEDS_LOGFILE) &&
2647 (po->po_flags & PMC_PO_OWNS_LOGFILE) == 0)
2648 return (EDOOFUS); /* programming error */
2649
2650 /*
2651 * If this is a sampling mode PMC, log mapping information for
2652 * the kernel modules that are currently loaded.
2653 */
2654 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)))
2655 pmc_log_kernel_mappings(pm);
2656
2657 if (PMC_IS_VIRTUAL_MODE(mode)) {
2658
2659 /*
2660 * If a PMCATTACH has never been done on this PMC,
2661 * attach it to its owner process.
2662 */
2663
2664 if (LIST_EMPTY(&pm->pm_targets))
2665 error = (pm->pm_flags & PMC_F_ATTACH_DONE) ? ESRCH :
2666 pmc_attach_process(po->po_owner, pm);
2667
2668 /*
2669 * If the PMC is attached to its owner, then force a context
2670 * switch to ensure that the MD state gets set correctly.
2671 */
2672
2673 if (error == 0) {
2674 pm->pm_state = PMC_STATE_RUNNING;
2675 if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER)
2676 pmc_force_context_switch();
2677 }
2678
2679 return (error);
2680 }
2681
2682
2683 /*
2684 * A system-wide PMC.
2685 *
2686 * Add the owner to the global list if this is a system-wide
2687 * sampling PMC.
2688 */
2689
2690 if (mode == PMC_MODE_SS) {
2691 if (po->po_sscount == 0) {
2692 LIST_INSERT_HEAD(&pmc_ss_owners, po, po_ssnext);
2693 atomic_add_rel_int(&pmc_ss_count, 1);
2694 PMCDBG1(PMC,OPS,1, "po=%p in global list", po);
2695 }
2696 po->po_sscount++;
2697
2698 /*
2699 * Log mapping information for all existing processes in the
2700 * system. Subsequent mappings are logged as they happen;
2701 * see pmc_process_mmap().
2702 */
2703 if (po->po_logprocmaps == 0) {
2704 pmc_log_all_process_mappings(po);
2705 po->po_logprocmaps = 1;
2706 }
2707 }
2708
2709 /*
2710 * Move to the CPU associated with this
2711 * PMC, and start the hardware.
2712 */
2713
2714 pmc_save_cpu_binding(&pb);
2715
2716 cpu = PMC_TO_CPU(pm);
2717
2718 if (!pmc_cpu_is_active(cpu))
2719 return (ENXIO);
2720
2721 pmc_select_cpu(cpu);
2722
2723 /*
2724 * global PMCs are configured at allocation time
2725 * so write out the initial value and start the PMC.
2726 */
2727
2728 pm->pm_state = PMC_STATE_RUNNING;
2729
2730 critical_enter();
2731 if ((error = pcd->pcd_write_pmc(cpu, adjri,
2732 PMC_IS_SAMPLING_MODE(mode) ?
2733 pm->pm_sc.pm_reloadcount :
2734 pm->pm_sc.pm_initial)) == 0) {
2735 /* If a sampling mode PMC, reset stalled state. */
2736 if (PMC_IS_SAMPLING_MODE(mode))
2737 CPU_CLR_ATOMIC(cpu, &pm->pm_stalled);
2738
2739 /* Indicate that we desire this to run. Start it. */
2740 CPU_SET_ATOMIC(cpu, &pm->pm_cpustate);
2741 error = pcd->pcd_start_pmc(cpu, adjri);
2742 }
2743 critical_exit();
2744
2745 pmc_restore_cpu_binding(&pb);
2746
2747 return (error);
2748 }
2749
2750 /*
2751 * Stop a PMC.
2752 */
2753
2754 static int
pmc_stop(struct pmc * pm)2755 pmc_stop(struct pmc *pm)
2756 {
2757 struct pmc_owner *po;
2758 struct pmc_binding pb;
2759 struct pmc_classdep *pcd;
2760 int adjri, cpu, error, ri;
2761
2762 KASSERT(pm != NULL, ("[pmc,%d] null pmc", __LINE__));
2763
2764 PMCDBG3(PMC,OPS,1, "stop pmc=%p mode=%d ri=%d", pm,
2765 PMC_TO_MODE(pm), PMC_TO_ROWINDEX(pm));
2766
2767 pm->pm_state = PMC_STATE_STOPPED;
2768
2769 /*
2770 * If the PMC is a virtual mode one, changing the state to
2771 * non-RUNNING is enough to ensure that the PMC never gets
2772 * scheduled.
2773 *
2774 * If this PMC is current running on a CPU, then it will
2775 * handled correctly at the time its target process is context
2776 * switched out.
2777 */
2778
2779 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)))
2780 return 0;
2781
2782 /*
2783 * A system-mode PMC. Move to the CPU associated with
2784 * this PMC, and stop the hardware. We update the
2785 * 'initial count' so that a subsequent PMCSTART will
2786 * resume counting from the current hardware count.
2787 */
2788
2789 pmc_save_cpu_binding(&pb);
2790
2791 cpu = PMC_TO_CPU(pm);
2792
2793 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
2794 ("[pmc,%d] illegal cpu=%d", __LINE__, cpu));
2795
2796 if (!pmc_cpu_is_active(cpu))
2797 return ENXIO;
2798
2799 pmc_select_cpu(cpu);
2800
2801 ri = PMC_TO_ROWINDEX(pm);
2802 pcd = pmc_ri_to_classdep(md, ri, &adjri);
2803
2804 CPU_CLR_ATOMIC(cpu, &pm->pm_cpustate);
2805 critical_enter();
2806 if ((error = pcd->pcd_stop_pmc(cpu, adjri)) == 0)
2807 error = pcd->pcd_read_pmc(cpu, adjri, &pm->pm_sc.pm_initial);
2808 critical_exit();
2809
2810 pmc_restore_cpu_binding(&pb);
2811
2812 po = pm->pm_owner;
2813
2814 /* remove this owner from the global list of SS PMC owners */
2815 if (PMC_TO_MODE(pm) == PMC_MODE_SS) {
2816 po->po_sscount--;
2817 if (po->po_sscount == 0) {
2818 atomic_subtract_rel_int(&pmc_ss_count, 1);
2819 LIST_REMOVE(po, po_ssnext);
2820 PMCDBG1(PMC,OPS,2,"po=%p removed from global list", po);
2821 }
2822 }
2823
2824 return (error);
2825 }
2826
2827
2828 #ifdef HWPMC_DEBUG
2829 static const char *pmc_op_to_name[] = {
2830 #undef __PMC_OP
2831 #define __PMC_OP(N, D) #N ,
2832 __PMC_OPS()
2833 NULL
2834 };
2835 #endif
2836
2837 /*
2838 * The syscall interface
2839 */
2840
2841 #define PMC_GET_SX_XLOCK(...) do { \
2842 sx_xlock(&pmc_sx); \
2843 if (pmc_hook == NULL) { \
2844 sx_xunlock(&pmc_sx); \
2845 return __VA_ARGS__; \
2846 } \
2847 } while (0)
2848
2849 #define PMC_DOWNGRADE_SX() do { \
2850 sx_downgrade(&pmc_sx); \
2851 is_sx_downgraded = 1; \
2852 } while (0)
2853
2854 static int
pmc_syscall_handler(struct thread * td,void * syscall_args)2855 pmc_syscall_handler(struct thread *td, void *syscall_args)
2856 {
2857 int error, is_sx_downgraded, is_sx_locked, op;
2858 struct pmc_syscall_args *c;
2859 void *arg;
2860
2861 PMC_GET_SX_XLOCK(ENOSYS);
2862
2863 DROP_GIANT();
2864
2865 is_sx_downgraded = 0;
2866 is_sx_locked = 1;
2867
2868 c = (struct pmc_syscall_args *) syscall_args;
2869
2870 op = c->pmop_code;
2871 arg = c->pmop_data;
2872
2873 PMCDBG3(MOD,PMS,1, "syscall op=%d \"%s\" arg=%p", op,
2874 pmc_op_to_name[op], arg);
2875
2876 error = 0;
2877 atomic_add_int(&pmc_stats.pm_syscalls, 1);
2878
2879 switch(op)
2880 {
2881
2882
2883 /*
2884 * Configure a log file.
2885 *
2886 * XXX This OP will be reworked.
2887 */
2888
2889 case PMC_OP_CONFIGURELOG:
2890 {
2891 struct proc *p;
2892 struct pmc *pm;
2893 struct pmc_owner *po;
2894 struct pmc_op_configurelog cl;
2895
2896 sx_assert(&pmc_sx, SX_XLOCKED);
2897
2898 if ((error = copyin(arg, &cl, sizeof(cl))) != 0)
2899 break;
2900
2901 /* mark this process as owning a log file */
2902 p = td->td_proc;
2903 if ((po = pmc_find_owner_descriptor(p)) == NULL)
2904 if ((po = pmc_allocate_owner_descriptor(p)) == NULL) {
2905 error = ENOMEM;
2906 break;
2907 }
2908
2909 /*
2910 * If a valid fd was passed in, try to configure that,
2911 * otherwise if 'fd' was less than zero and there was
2912 * a log file configured, flush its buffers and
2913 * de-configure it.
2914 */
2915 if (cl.pm_logfd >= 0) {
2916 sx_xunlock(&pmc_sx);
2917 is_sx_locked = 0;
2918 error = pmclog_configure_log(md, po, cl.pm_logfd);
2919 } else if (po->po_flags & PMC_PO_OWNS_LOGFILE) {
2920 pmclog_process_closelog(po);
2921 error = pmclog_close(po);
2922 if (error == 0) {
2923 LIST_FOREACH(pm, &po->po_pmcs, pm_next)
2924 if (pm->pm_flags & PMC_F_NEEDS_LOGFILE &&
2925 pm->pm_state == PMC_STATE_RUNNING)
2926 pmc_stop(pm);
2927 error = pmclog_deconfigure_log(po);
2928 }
2929 } else
2930 error = EINVAL;
2931
2932 if (error)
2933 break;
2934 }
2935 break;
2936
2937 /*
2938 * Flush a log file.
2939 */
2940
2941 case PMC_OP_FLUSHLOG:
2942 {
2943 struct pmc_owner *po;
2944
2945 sx_assert(&pmc_sx, SX_XLOCKED);
2946
2947 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) {
2948 error = EINVAL;
2949 break;
2950 }
2951
2952 error = pmclog_flush(po);
2953 }
2954 break;
2955
2956 /*
2957 * Close a log file.
2958 */
2959
2960 case PMC_OP_CLOSELOG:
2961 {
2962 struct pmc_owner *po;
2963
2964 sx_assert(&pmc_sx, SX_XLOCKED);
2965
2966 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) {
2967 error = EINVAL;
2968 break;
2969 }
2970
2971 error = pmclog_close(po);
2972 }
2973 break;
2974
2975 /*
2976 * Retrieve hardware configuration.
2977 */
2978
2979 case PMC_OP_GETCPUINFO: /* CPU information */
2980 {
2981 struct pmc_op_getcpuinfo gci;
2982 struct pmc_classinfo *pci;
2983 struct pmc_classdep *pcd;
2984 int cl;
2985
2986 gci.pm_cputype = md->pmd_cputype;
2987 gci.pm_ncpu = pmc_cpu_max();
2988 gci.pm_npmc = md->pmd_npmc;
2989 gci.pm_nclass = md->pmd_nclass;
2990 pci = gci.pm_classes;
2991 pcd = md->pmd_classdep;
2992 for (cl = 0; cl < md->pmd_nclass; cl++, pci++, pcd++) {
2993 pci->pm_caps = pcd->pcd_caps;
2994 pci->pm_class = pcd->pcd_class;
2995 pci->pm_width = pcd->pcd_width;
2996 pci->pm_num = pcd->pcd_num;
2997 }
2998 error = copyout(&gci, arg, sizeof(gci));
2999 }
3000 break;
3001
3002 /*
3003 * Retrieve soft events list.
3004 */
3005 case PMC_OP_GETDYNEVENTINFO:
3006 {
3007 enum pmc_class cl;
3008 enum pmc_event ev;
3009 struct pmc_op_getdyneventinfo *gei;
3010 struct pmc_dyn_event_descr dev;
3011 struct pmc_soft *ps;
3012 uint32_t nevent;
3013
3014 sx_assert(&pmc_sx, SX_LOCKED);
3015
3016 gei = (struct pmc_op_getdyneventinfo *) arg;
3017
3018 if ((error = copyin(&gei->pm_class, &cl, sizeof(cl))) != 0)
3019 break;
3020
3021 /* Only SOFT class is dynamic. */
3022 if (cl != PMC_CLASS_SOFT) {
3023 error = EINVAL;
3024 break;
3025 }
3026
3027 nevent = 0;
3028 for (ev = PMC_EV_SOFT_FIRST; (int)ev <= PMC_EV_SOFT_LAST; ev++) {
3029 ps = pmc_soft_ev_acquire(ev);
3030 if (ps == NULL)
3031 continue;
3032 bcopy(&ps->ps_ev, &dev, sizeof(dev));
3033 pmc_soft_ev_release(ps);
3034
3035 error = copyout(&dev,
3036 &gei->pm_events[nevent],
3037 sizeof(struct pmc_dyn_event_descr));
3038 if (error != 0)
3039 break;
3040 nevent++;
3041 }
3042 if (error != 0)
3043 break;
3044
3045 error = copyout(&nevent, &gei->pm_nevent,
3046 sizeof(nevent));
3047 }
3048 break;
3049
3050 /*
3051 * Get module statistics
3052 */
3053
3054 case PMC_OP_GETDRIVERSTATS:
3055 {
3056 struct pmc_op_getdriverstats gms;
3057
3058 bcopy(&pmc_stats, &gms, sizeof(gms));
3059 error = copyout(&gms, arg, sizeof(gms));
3060 }
3061 break;
3062
3063
3064 /*
3065 * Retrieve module version number
3066 */
3067
3068 case PMC_OP_GETMODULEVERSION:
3069 {
3070 uint32_t cv, modv;
3071
3072 /* retrieve the client's idea of the ABI version */
3073 if ((error = copyin(arg, &cv, sizeof(uint32_t))) != 0)
3074 break;
3075 /* don't service clients newer than our driver */
3076 modv = PMC_VERSION;
3077 if ((cv & 0xFFFF0000) > (modv & 0xFFFF0000)) {
3078 error = EPROGMISMATCH;
3079 break;
3080 }
3081 error = copyout(&modv, arg, sizeof(int));
3082 }
3083 break;
3084
3085
3086 /*
3087 * Retrieve the state of all the PMCs on a given
3088 * CPU.
3089 */
3090
3091 case PMC_OP_GETPMCINFO:
3092 {
3093 int ari;
3094 struct pmc *pm;
3095 size_t pmcinfo_size;
3096 uint32_t cpu, n, npmc;
3097 struct pmc_owner *po;
3098 struct pmc_binding pb;
3099 struct pmc_classdep *pcd;
3100 struct pmc_info *p, *pmcinfo;
3101 struct pmc_op_getpmcinfo *gpi;
3102
3103 PMC_DOWNGRADE_SX();
3104
3105 gpi = (struct pmc_op_getpmcinfo *) arg;
3106
3107 if ((error = copyin(&gpi->pm_cpu, &cpu, sizeof(cpu))) != 0)
3108 break;
3109
3110 if (cpu >= pmc_cpu_max()) {
3111 error = EINVAL;
3112 break;
3113 }
3114
3115 if (!pmc_cpu_is_active(cpu)) {
3116 error = ENXIO;
3117 break;
3118 }
3119
3120 /* switch to CPU 'cpu' */
3121 pmc_save_cpu_binding(&pb);
3122 pmc_select_cpu(cpu);
3123
3124 npmc = md->pmd_npmc;
3125
3126 pmcinfo_size = npmc * sizeof(struct pmc_info);
3127 pmcinfo = malloc(pmcinfo_size, M_PMC, M_WAITOK);
3128
3129 p = pmcinfo;
3130
3131 for (n = 0; n < md->pmd_npmc; n++, p++) {
3132
3133 pcd = pmc_ri_to_classdep(md, n, &ari);
3134
3135 KASSERT(pcd != NULL,
3136 ("[pmc,%d] null pcd ri=%d", __LINE__, n));
3137
3138 if ((error = pcd->pcd_describe(cpu, ari, p, &pm)) != 0)
3139 break;
3140
3141 if (PMC_ROW_DISP_IS_STANDALONE(n))
3142 p->pm_rowdisp = PMC_DISP_STANDALONE;
3143 else if (PMC_ROW_DISP_IS_THREAD(n))
3144 p->pm_rowdisp = PMC_DISP_THREAD;
3145 else
3146 p->pm_rowdisp = PMC_DISP_FREE;
3147
3148 p->pm_ownerpid = -1;
3149
3150 if (pm == NULL) /* no PMC associated */
3151 continue;
3152
3153 po = pm->pm_owner;
3154
3155 KASSERT(po->po_owner != NULL,
3156 ("[pmc,%d] pmc_owner had a null proc pointer",
3157 __LINE__));
3158
3159 p->pm_ownerpid = po->po_owner->p_pid;
3160 p->pm_mode = PMC_TO_MODE(pm);
3161 p->pm_event = pm->pm_event;
3162 p->pm_flags = pm->pm_flags;
3163
3164 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)))
3165 p->pm_reloadcount =
3166 pm->pm_sc.pm_reloadcount;
3167 }
3168
3169 pmc_restore_cpu_binding(&pb);
3170
3171 /* now copy out the PMC info collected */
3172 if (error == 0)
3173 error = copyout(pmcinfo, &gpi->pm_pmcs, pmcinfo_size);
3174
3175 free(pmcinfo, M_PMC);
3176 }
3177 break;
3178
3179
3180 /*
3181 * Set the administrative state of a PMC. I.e. whether
3182 * the PMC is to be used or not.
3183 */
3184
3185 case PMC_OP_PMCADMIN:
3186 {
3187 int cpu, ri;
3188 enum pmc_state request;
3189 struct pmc_cpu *pc;
3190 struct pmc_hw *phw;
3191 struct pmc_op_pmcadmin pma;
3192 struct pmc_binding pb;
3193
3194 sx_assert(&pmc_sx, SX_XLOCKED);
3195
3196 KASSERT(td == curthread,
3197 ("[pmc,%d] td != curthread", __LINE__));
3198
3199 error = priv_check(td, PRIV_PMC_MANAGE);
3200 if (error)
3201 break;
3202
3203 if ((error = copyin(arg, &pma, sizeof(pma))) != 0)
3204 break;
3205
3206 cpu = pma.pm_cpu;
3207
3208 if (cpu < 0 || cpu >= (int) pmc_cpu_max()) {
3209 error = EINVAL;
3210 break;
3211 }
3212
3213 if (!pmc_cpu_is_active(cpu)) {
3214 error = ENXIO;
3215 break;
3216 }
3217
3218 request = pma.pm_state;
3219
3220 if (request != PMC_STATE_DISABLED &&
3221 request != PMC_STATE_FREE) {
3222 error = EINVAL;
3223 break;
3224 }
3225
3226 ri = pma.pm_pmc; /* pmc id == row index */
3227 if (ri < 0 || ri >= (int) md->pmd_npmc) {
3228 error = EINVAL;
3229 break;
3230 }
3231
3232 /*
3233 * We can't disable a PMC with a row-index allocated
3234 * for process virtual PMCs.
3235 */
3236
3237 if (PMC_ROW_DISP_IS_THREAD(ri) &&
3238 request == PMC_STATE_DISABLED) {
3239 error = EBUSY;
3240 break;
3241 }
3242
3243 /*
3244 * otherwise, this PMC on this CPU is either free or
3245 * in system-wide mode.
3246 */
3247
3248 pmc_save_cpu_binding(&pb);
3249 pmc_select_cpu(cpu);
3250
3251 pc = pmc_pcpu[cpu];
3252 phw = pc->pc_hwpmcs[ri];
3253
3254 /*
3255 * XXX do we need some kind of 'forced' disable?
3256 */
3257
3258 if (phw->phw_pmc == NULL) {
3259 if (request == PMC_STATE_DISABLED &&
3260 (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED)) {
3261 phw->phw_state &= ~PMC_PHW_FLAG_IS_ENABLED;
3262 PMC_MARK_ROW_STANDALONE(ri);
3263 } else if (request == PMC_STATE_FREE &&
3264 (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0) {
3265 phw->phw_state |= PMC_PHW_FLAG_IS_ENABLED;
3266 PMC_UNMARK_ROW_STANDALONE(ri);
3267 }
3268 /* other cases are a no-op */
3269 } else
3270 error = EBUSY;
3271
3272 pmc_restore_cpu_binding(&pb);
3273 }
3274 break;
3275
3276
3277 /*
3278 * Allocate a PMC.
3279 */
3280
3281 case PMC_OP_PMCALLOCATE:
3282 {
3283 int adjri, n;
3284 u_int cpu;
3285 uint32_t caps;
3286 struct pmc *pmc;
3287 enum pmc_mode mode;
3288 struct pmc_hw *phw;
3289 struct pmc_binding pb;
3290 struct pmc_classdep *pcd;
3291 struct pmc_op_pmcallocate pa;
3292
3293 if ((error = copyin(arg, &pa, sizeof(pa))) != 0)
3294 break;
3295
3296 caps = pa.pm_caps;
3297 mode = pa.pm_mode;
3298 cpu = pa.pm_cpu;
3299
3300 if ((mode != PMC_MODE_SS && mode != PMC_MODE_SC &&
3301 mode != PMC_MODE_TS && mode != PMC_MODE_TC) ||
3302 (cpu != (u_int) PMC_CPU_ANY && cpu >= pmc_cpu_max())) {
3303 error = EINVAL;
3304 break;
3305 }
3306
3307 /*
3308 * Virtual PMCs should only ask for a default CPU.
3309 * System mode PMCs need to specify a non-default CPU.
3310 */
3311
3312 if ((PMC_IS_VIRTUAL_MODE(mode) && cpu != (u_int) PMC_CPU_ANY) ||
3313 (PMC_IS_SYSTEM_MODE(mode) && cpu == (u_int) PMC_CPU_ANY)) {
3314 error = EINVAL;
3315 break;
3316 }
3317
3318 /*
3319 * Check that an inactive CPU is not being asked for.
3320 */
3321
3322 if (PMC_IS_SYSTEM_MODE(mode) && !pmc_cpu_is_active(cpu)) {
3323 error = ENXIO;
3324 break;
3325 }
3326
3327 /*
3328 * Refuse an allocation for a system-wide PMC if this
3329 * process has been jailed, or if this process lacks
3330 * super-user credentials and the sysctl tunable
3331 * 'security.bsd.unprivileged_syspmcs' is zero.
3332 */
3333
3334 if (PMC_IS_SYSTEM_MODE(mode)) {
3335 if (jailed(curthread->td_ucred)) {
3336 error = EPERM;
3337 break;
3338 }
3339 if (!pmc_unprivileged_syspmcs) {
3340 error = priv_check(curthread,
3341 PRIV_PMC_SYSTEM);
3342 if (error)
3343 break;
3344 }
3345 }
3346
3347 /*
3348 * Look for valid values for 'pm_flags'
3349 */
3350
3351 if ((pa.pm_flags & ~(PMC_F_DESCENDANTS | PMC_F_LOG_PROCCSW |
3352 PMC_F_LOG_PROCEXIT | PMC_F_CALLCHAIN)) != 0) {
3353 error = EINVAL;
3354 break;
3355 }
3356
3357 /* process logging options are not allowed for system PMCs */
3358 if (PMC_IS_SYSTEM_MODE(mode) && (pa.pm_flags &
3359 (PMC_F_LOG_PROCCSW | PMC_F_LOG_PROCEXIT))) {
3360 error = EINVAL;
3361 break;
3362 }
3363
3364 /*
3365 * All sampling mode PMCs need to be able to interrupt the
3366 * CPU.
3367 */
3368 if (PMC_IS_SAMPLING_MODE(mode))
3369 caps |= PMC_CAP_INTERRUPT;
3370
3371 /* A valid class specifier should have been passed in. */
3372 for (n = 0; n < md->pmd_nclass; n++)
3373 if (md->pmd_classdep[n].pcd_class == pa.pm_class)
3374 break;
3375 if (n == md->pmd_nclass) {
3376 error = EINVAL;
3377 break;
3378 }
3379
3380 /* The requested PMC capabilities should be feasible. */
3381 if ((md->pmd_classdep[n].pcd_caps & caps) != caps) {
3382 error = EOPNOTSUPP;
3383 break;
3384 }
3385
3386 PMCDBG4(PMC,ALL,2, "event=%d caps=0x%x mode=%d cpu=%d",
3387 pa.pm_ev, caps, mode, cpu);
3388
3389 pmc = pmc_allocate_pmc_descriptor();
3390 pmc->pm_id = PMC_ID_MAKE_ID(cpu,pa.pm_mode,pa.pm_class,
3391 PMC_ID_INVALID);
3392 pmc->pm_event = pa.pm_ev;
3393 pmc->pm_state = PMC_STATE_FREE;
3394 pmc->pm_caps = caps;
3395 pmc->pm_flags = pa.pm_flags;
3396
3397 /* switch thread to CPU 'cpu' */
3398 pmc_save_cpu_binding(&pb);
3399
3400 #define PMC_IS_SHAREABLE_PMC(cpu, n) \
3401 (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_state & \
3402 PMC_PHW_FLAG_IS_SHAREABLE)
3403 #define PMC_IS_UNALLOCATED(cpu, n) \
3404 (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_pmc == NULL)
3405
3406 if (PMC_IS_SYSTEM_MODE(mode)) {
3407 pmc_select_cpu(cpu);
3408 for (n = 0; n < (int) md->pmd_npmc; n++) {
3409 pcd = pmc_ri_to_classdep(md, n, &adjri);
3410 if (pmc_can_allocate_row(n, mode) == 0 &&
3411 pmc_can_allocate_rowindex(
3412 curthread->td_proc, n, cpu) == 0 &&
3413 (PMC_IS_UNALLOCATED(cpu, n) ||
3414 PMC_IS_SHAREABLE_PMC(cpu, n)) &&
3415 pcd->pcd_allocate_pmc(cpu, adjri, pmc,
3416 &pa) == 0)
3417 break;
3418 }
3419 } else {
3420 /* Process virtual mode */
3421 for (n = 0; n < (int) md->pmd_npmc; n++) {
3422 pcd = pmc_ri_to_classdep(md, n, &adjri);
3423 if (pmc_can_allocate_row(n, mode) == 0 &&
3424 pmc_can_allocate_rowindex(
3425 curthread->td_proc, n,
3426 PMC_CPU_ANY) == 0 &&
3427 pcd->pcd_allocate_pmc(curthread->td_oncpu,
3428 adjri, pmc, &pa) == 0)
3429 break;
3430 }
3431 }
3432
3433 #undef PMC_IS_UNALLOCATED
3434 #undef PMC_IS_SHAREABLE_PMC
3435
3436 pmc_restore_cpu_binding(&pb);
3437
3438 if (n == (int) md->pmd_npmc) {
3439 pmc_destroy_pmc_descriptor(pmc);
3440 pmc = NULL;
3441 error = EINVAL;
3442 break;
3443 }
3444
3445 /* Fill in the correct value in the ID field */
3446 pmc->pm_id = PMC_ID_MAKE_ID(cpu,mode,pa.pm_class,n);
3447
3448 PMCDBG5(PMC,ALL,2, "ev=%d class=%d mode=%d n=%d -> pmcid=%x",
3449 pmc->pm_event, pa.pm_class, mode, n, pmc->pm_id);
3450
3451 /* Process mode PMCs with logging enabled need log files */
3452 if (pmc->pm_flags & (PMC_F_LOG_PROCEXIT | PMC_F_LOG_PROCCSW))
3453 pmc->pm_flags |= PMC_F_NEEDS_LOGFILE;
3454
3455 /* All system mode sampling PMCs require a log file */
3456 if (PMC_IS_SAMPLING_MODE(mode) && PMC_IS_SYSTEM_MODE(mode))
3457 pmc->pm_flags |= PMC_F_NEEDS_LOGFILE;
3458
3459 /*
3460 * Configure global pmc's immediately
3461 */
3462
3463 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pmc))) {
3464
3465 pmc_save_cpu_binding(&pb);
3466 pmc_select_cpu(cpu);
3467
3468 phw = pmc_pcpu[cpu]->pc_hwpmcs[n];
3469 pcd = pmc_ri_to_classdep(md, n, &adjri);
3470
3471 if ((phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0 ||
3472 (error = pcd->pcd_config_pmc(cpu, adjri, pmc)) != 0) {
3473 (void) pcd->pcd_release_pmc(cpu, adjri, pmc);
3474 pmc_destroy_pmc_descriptor(pmc);
3475 pmc = NULL;
3476 pmc_restore_cpu_binding(&pb);
3477 error = EPERM;
3478 break;
3479 }
3480
3481 pmc_restore_cpu_binding(&pb);
3482 }
3483
3484 pmc->pm_state = PMC_STATE_ALLOCATED;
3485
3486 /*
3487 * mark row disposition
3488 */
3489
3490 if (PMC_IS_SYSTEM_MODE(mode))
3491 PMC_MARK_ROW_STANDALONE(n);
3492 else
3493 PMC_MARK_ROW_THREAD(n);
3494
3495 /*
3496 * Register this PMC with the current thread as its owner.
3497 */
3498
3499 if ((error =
3500 pmc_register_owner(curthread->td_proc, pmc)) != 0) {
3501 pmc_release_pmc_descriptor(pmc);
3502 pmc_destroy_pmc_descriptor(pmc);
3503 pmc = NULL;
3504 break;
3505 }
3506
3507 /*
3508 * Return the allocated index.
3509 */
3510
3511 pa.pm_pmcid = pmc->pm_id;
3512
3513 error = copyout(&pa, arg, sizeof(pa));
3514 }
3515 break;
3516
3517
3518 /*
3519 * Attach a PMC to a process.
3520 */
3521
3522 case PMC_OP_PMCATTACH:
3523 {
3524 struct pmc *pm;
3525 struct proc *p;
3526 struct pmc_op_pmcattach a;
3527
3528 sx_assert(&pmc_sx, SX_XLOCKED);
3529
3530 if ((error = copyin(arg, &a, sizeof(a))) != 0)
3531 break;
3532
3533 if (a.pm_pid < 0) {
3534 error = EINVAL;
3535 break;
3536 } else if (a.pm_pid == 0)
3537 a.pm_pid = td->td_proc->p_pid;
3538
3539 if ((error = pmc_find_pmc(a.pm_pmc, &pm)) != 0)
3540 break;
3541
3542 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) {
3543 error = EINVAL;
3544 break;
3545 }
3546
3547 /* PMCs may be (re)attached only when allocated or stopped */
3548 if (pm->pm_state == PMC_STATE_RUNNING) {
3549 error = EBUSY;
3550 break;
3551 } else if (pm->pm_state != PMC_STATE_ALLOCATED &&
3552 pm->pm_state != PMC_STATE_STOPPED) {
3553 error = EINVAL;
3554 break;
3555 }
3556
3557 /* lookup pid */
3558 if ((p = pfind(a.pm_pid)) == NULL) {
3559 error = ESRCH;
3560 break;
3561 }
3562
3563 /*
3564 * Ignore processes that are working on exiting.
3565 */
3566 if (p->p_flag & P_WEXIT) {
3567 error = ESRCH;
3568 PROC_UNLOCK(p); /* pfind() returns a locked process */
3569 break;
3570 }
3571
3572 /*
3573 * we are allowed to attach a PMC to a process if
3574 * we can debug it.
3575 */
3576 error = p_candebug(curthread, p);
3577
3578 PROC_UNLOCK(p);
3579
3580 if (error == 0)
3581 error = pmc_attach_process(p, pm);
3582 }
3583 break;
3584
3585
3586 /*
3587 * Detach an attached PMC from a process.
3588 */
3589
3590 case PMC_OP_PMCDETACH:
3591 {
3592 struct pmc *pm;
3593 struct proc *p;
3594 struct pmc_op_pmcattach a;
3595
3596 if ((error = copyin(arg, &a, sizeof(a))) != 0)
3597 break;
3598
3599 if (a.pm_pid < 0) {
3600 error = EINVAL;
3601 break;
3602 } else if (a.pm_pid == 0)
3603 a.pm_pid = td->td_proc->p_pid;
3604
3605 if ((error = pmc_find_pmc(a.pm_pmc, &pm)) != 0)
3606 break;
3607
3608 if ((p = pfind(a.pm_pid)) == NULL) {
3609 error = ESRCH;
3610 break;
3611 }
3612
3613 /*
3614 * Treat processes that are in the process of exiting
3615 * as if they were not present.
3616 */
3617
3618 if (p->p_flag & P_WEXIT)
3619 error = ESRCH;
3620
3621 PROC_UNLOCK(p); /* pfind() returns a locked process */
3622
3623 if (error == 0)
3624 error = pmc_detach_process(p, pm);
3625 }
3626 break;
3627
3628
3629 /*
3630 * Retrieve the MSR number associated with the counter
3631 * 'pmc_id'. This allows processes to directly use RDPMC
3632 * instructions to read their PMCs, without the overhead of a
3633 * system call.
3634 */
3635
3636 case PMC_OP_PMCGETMSR:
3637 {
3638 int adjri, ri;
3639 struct pmc *pm;
3640 struct pmc_target *pt;
3641 struct pmc_op_getmsr gm;
3642 struct pmc_classdep *pcd;
3643
3644 PMC_DOWNGRADE_SX();
3645
3646 if ((error = copyin(arg, &gm, sizeof(gm))) != 0)
3647 break;
3648
3649 if ((error = pmc_find_pmc(gm.pm_pmcid, &pm)) != 0)
3650 break;
3651
3652 /*
3653 * The allocated PMC has to be a process virtual PMC,
3654 * i.e., of type MODE_T[CS]. Global PMCs can only be
3655 * read using the PMCREAD operation since they may be
3656 * allocated on a different CPU than the one we could
3657 * be running on at the time of the RDPMC instruction.
3658 *
3659 * The GETMSR operation is not allowed for PMCs that
3660 * are inherited across processes.
3661 */
3662
3663 if (!PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)) ||
3664 (pm->pm_flags & PMC_F_DESCENDANTS)) {
3665 error = EINVAL;
3666 break;
3667 }
3668
3669 /*
3670 * It only makes sense to use a RDPMC (or its
3671 * equivalent instruction on non-x86 architectures) on
3672 * a process that has allocated and attached a PMC to
3673 * itself. Conversely the PMC is only allowed to have
3674 * one process attached to it -- its owner.
3675 */
3676
3677 if ((pt = LIST_FIRST(&pm->pm_targets)) == NULL ||
3678 LIST_NEXT(pt, pt_next) != NULL ||
3679 pt->pt_process->pp_proc != pm->pm_owner->po_owner) {
3680 error = EINVAL;
3681 break;
3682 }
3683
3684 ri = PMC_TO_ROWINDEX(pm);
3685 pcd = pmc_ri_to_classdep(md, ri, &adjri);
3686
3687 /* PMC class has no 'GETMSR' support */
3688 if (pcd->pcd_get_msr == NULL) {
3689 error = ENOSYS;
3690 break;
3691 }
3692
3693 if ((error = (*pcd->pcd_get_msr)(adjri, &gm.pm_msr)) < 0)
3694 break;
3695
3696 if ((error = copyout(&gm, arg, sizeof(gm))) < 0)
3697 break;
3698
3699 /*
3700 * Mark our process as using MSRs. Update machine
3701 * state using a forced context switch.
3702 */
3703
3704 pt->pt_process->pp_flags |= PMC_PP_ENABLE_MSR_ACCESS;
3705 pmc_force_context_switch();
3706
3707 }
3708 break;
3709
3710 /*
3711 * Release an allocated PMC
3712 */
3713
3714 case PMC_OP_PMCRELEASE:
3715 {
3716 pmc_id_t pmcid;
3717 struct pmc *pm;
3718 struct pmc_owner *po;
3719 struct pmc_op_simple sp;
3720
3721 /*
3722 * Find PMC pointer for the named PMC.
3723 *
3724 * Use pmc_release_pmc_descriptor() to switch off the
3725 * PMC, remove all its target threads, and remove the
3726 * PMC from its owner's list.
3727 *
3728 * Remove the owner record if this is the last PMC
3729 * owned.
3730 *
3731 * Free up space.
3732 */
3733
3734 if ((error = copyin(arg, &sp, sizeof(sp))) != 0)
3735 break;
3736
3737 pmcid = sp.pm_pmcid;
3738
3739 if ((error = pmc_find_pmc(pmcid, &pm)) != 0)
3740 break;
3741
3742 po = pm->pm_owner;
3743 pmc_release_pmc_descriptor(pm);
3744 pmc_maybe_remove_owner(po);
3745 pmc_destroy_pmc_descriptor(pm);
3746 }
3747 break;
3748
3749
3750 /*
3751 * Read and/or write a PMC.
3752 */
3753
3754 case PMC_OP_PMCRW:
3755 {
3756 int adjri;
3757 struct pmc *pm;
3758 uint32_t cpu, ri;
3759 pmc_value_t oldvalue;
3760 struct pmc_binding pb;
3761 struct pmc_op_pmcrw prw;
3762 struct pmc_classdep *pcd;
3763 struct pmc_op_pmcrw *pprw;
3764
3765 PMC_DOWNGRADE_SX();
3766
3767 if ((error = copyin(arg, &prw, sizeof(prw))) != 0)
3768 break;
3769
3770 ri = 0;
3771 PMCDBG2(PMC,OPS,1, "rw id=%d flags=0x%x", prw.pm_pmcid,
3772 prw.pm_flags);
3773
3774 /* must have at least one flag set */
3775 if ((prw.pm_flags & (PMC_F_OLDVALUE|PMC_F_NEWVALUE)) == 0) {
3776 error = EINVAL;
3777 break;
3778 }
3779
3780 /* locate pmc descriptor */
3781 if ((error = pmc_find_pmc(prw.pm_pmcid, &pm)) != 0)
3782 break;
3783
3784 /* Can't read a PMC that hasn't been started. */
3785 if (pm->pm_state != PMC_STATE_ALLOCATED &&
3786 pm->pm_state != PMC_STATE_STOPPED &&
3787 pm->pm_state != PMC_STATE_RUNNING) {
3788 error = EINVAL;
3789 break;
3790 }
3791
3792 /* writing a new value is allowed only for 'STOPPED' pmcs */
3793 if (pm->pm_state == PMC_STATE_RUNNING &&
3794 (prw.pm_flags & PMC_F_NEWVALUE)) {
3795 error = EBUSY;
3796 break;
3797 }
3798
3799 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) {
3800
3801 /*
3802 * If this PMC is attached to its owner (i.e.,
3803 * the process requesting this operation) and
3804 * is running, then attempt to get an
3805 * upto-date reading from hardware for a READ.
3806 * Writes are only allowed when the PMC is
3807 * stopped, so only update the saved value
3808 * field.
3809 *
3810 * If the PMC is not running, or is not
3811 * attached to its owner, read/write to the
3812 * savedvalue field.
3813 */
3814
3815 ri = PMC_TO_ROWINDEX(pm);
3816 pcd = pmc_ri_to_classdep(md, ri, &adjri);
3817
3818 mtx_pool_lock_spin(pmc_mtxpool, pm);
3819 cpu = curthread->td_oncpu;
3820
3821 if (prw.pm_flags & PMC_F_OLDVALUE) {
3822 if ((pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) &&
3823 (pm->pm_state == PMC_STATE_RUNNING))
3824 error = (*pcd->pcd_read_pmc)(cpu, adjri,
3825 &oldvalue);
3826 else
3827 oldvalue = pm->pm_gv.pm_savedvalue;
3828 }
3829 if (prw.pm_flags & PMC_F_NEWVALUE)
3830 pm->pm_gv.pm_savedvalue = prw.pm_value;
3831
3832 mtx_pool_unlock_spin(pmc_mtxpool, pm);
3833
3834 } else { /* System mode PMCs */
3835 cpu = PMC_TO_CPU(pm);
3836 ri = PMC_TO_ROWINDEX(pm);
3837 pcd = pmc_ri_to_classdep(md, ri, &adjri);
3838
3839 if (!pmc_cpu_is_active(cpu)) {
3840 error = ENXIO;
3841 break;
3842 }
3843
3844 /* move this thread to CPU 'cpu' */
3845 pmc_save_cpu_binding(&pb);
3846 pmc_select_cpu(cpu);
3847
3848 critical_enter();
3849 /* save old value */
3850 if (prw.pm_flags & PMC_F_OLDVALUE)
3851 if ((error = (*pcd->pcd_read_pmc)(cpu, adjri,
3852 &oldvalue)))
3853 goto error;
3854 /* write out new value */
3855 if (prw.pm_flags & PMC_F_NEWVALUE)
3856 error = (*pcd->pcd_write_pmc)(cpu, adjri,
3857 prw.pm_value);
3858 error:
3859 critical_exit();
3860 pmc_restore_cpu_binding(&pb);
3861 if (error)
3862 break;
3863 }
3864
3865 pprw = (struct pmc_op_pmcrw *) arg;
3866
3867 #ifdef HWPMC_DEBUG
3868 if (prw.pm_flags & PMC_F_NEWVALUE)
3869 PMCDBG3(PMC,OPS,2, "rw id=%d new %jx -> old %jx",
3870 ri, prw.pm_value, oldvalue);
3871 else if (prw.pm_flags & PMC_F_OLDVALUE)
3872 PMCDBG2(PMC,OPS,2, "rw id=%d -> old %jx", ri, oldvalue);
3873 #endif
3874
3875 /* return old value if requested */
3876 if (prw.pm_flags & PMC_F_OLDVALUE)
3877 if ((error = copyout(&oldvalue, &pprw->pm_value,
3878 sizeof(prw.pm_value))))
3879 break;
3880
3881 }
3882 break;
3883
3884
3885 /*
3886 * Set the sampling rate for a sampling mode PMC and the
3887 * initial count for a counting mode PMC.
3888 */
3889
3890 case PMC_OP_PMCSETCOUNT:
3891 {
3892 struct pmc *pm;
3893 struct pmc_op_pmcsetcount sc;
3894
3895 PMC_DOWNGRADE_SX();
3896
3897 if ((error = copyin(arg, &sc, sizeof(sc))) != 0)
3898 break;
3899
3900 if ((error = pmc_find_pmc(sc.pm_pmcid, &pm)) != 0)
3901 break;
3902
3903 if (pm->pm_state == PMC_STATE_RUNNING) {
3904 error = EBUSY;
3905 break;
3906 }
3907
3908 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)))
3909 pm->pm_sc.pm_reloadcount = sc.pm_count;
3910 else
3911 pm->pm_sc.pm_initial = sc.pm_count;
3912 }
3913 break;
3914
3915
3916 /*
3917 * Start a PMC.
3918 */
3919
3920 case PMC_OP_PMCSTART:
3921 {
3922 pmc_id_t pmcid;
3923 struct pmc *pm;
3924 struct pmc_op_simple sp;
3925
3926 sx_assert(&pmc_sx, SX_XLOCKED);
3927
3928 if ((error = copyin(arg, &sp, sizeof(sp))) != 0)
3929 break;
3930
3931 pmcid = sp.pm_pmcid;
3932
3933 if ((error = pmc_find_pmc(pmcid, &pm)) != 0)
3934 break;
3935
3936 KASSERT(pmcid == pm->pm_id,
3937 ("[pmc,%d] pmcid %x != id %x", __LINE__,
3938 pm->pm_id, pmcid));
3939
3940 if (pm->pm_state == PMC_STATE_RUNNING) /* already running */
3941 break;
3942 else if (pm->pm_state != PMC_STATE_STOPPED &&
3943 pm->pm_state != PMC_STATE_ALLOCATED) {
3944 error = EINVAL;
3945 break;
3946 }
3947
3948 error = pmc_start(pm);
3949 }
3950 break;
3951
3952
3953 /*
3954 * Stop a PMC.
3955 */
3956
3957 case PMC_OP_PMCSTOP:
3958 {
3959 pmc_id_t pmcid;
3960 struct pmc *pm;
3961 struct pmc_op_simple sp;
3962
3963 PMC_DOWNGRADE_SX();
3964
3965 if ((error = copyin(arg, &sp, sizeof(sp))) != 0)
3966 break;
3967
3968 pmcid = sp.pm_pmcid;
3969
3970 /*
3971 * Mark the PMC as inactive and invoke the MD stop
3972 * routines if needed.
3973 */
3974
3975 if ((error = pmc_find_pmc(pmcid, &pm)) != 0)
3976 break;
3977
3978 KASSERT(pmcid == pm->pm_id,
3979 ("[pmc,%d] pmc id %x != pmcid %x", __LINE__,
3980 pm->pm_id, pmcid));
3981
3982 if (pm->pm_state == PMC_STATE_STOPPED) /* already stopped */
3983 break;
3984 else if (pm->pm_state != PMC_STATE_RUNNING) {
3985 error = EINVAL;
3986 break;
3987 }
3988
3989 error = pmc_stop(pm);
3990 }
3991 break;
3992
3993
3994 /*
3995 * Write a user supplied value to the log file.
3996 */
3997
3998 case PMC_OP_WRITELOG:
3999 {
4000 struct pmc_op_writelog wl;
4001 struct pmc_owner *po;
4002
4003 PMC_DOWNGRADE_SX();
4004
4005 if ((error = copyin(arg, &wl, sizeof(wl))) != 0)
4006 break;
4007
4008 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) {
4009 error = EINVAL;
4010 break;
4011 }
4012
4013 if ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) {
4014 error = EINVAL;
4015 break;
4016 }
4017
4018 error = pmclog_process_userlog(po, &wl);
4019 }
4020 break;
4021
4022
4023 default:
4024 error = EINVAL;
4025 break;
4026 }
4027
4028 if (is_sx_locked != 0) {
4029 if (is_sx_downgraded)
4030 sx_sunlock(&pmc_sx);
4031 else
4032 sx_xunlock(&pmc_sx);
4033 }
4034
4035 if (error)
4036 atomic_add_int(&pmc_stats.pm_syscall_errors, 1);
4037
4038 PICKUP_GIANT();
4039
4040 return error;
4041 }
4042
4043 /*
4044 * Helper functions
4045 */
4046
4047
4048 /*
4049 * Mark the thread as needing callchain capture and post an AST. The
4050 * actual callchain capture will be done in a context where it is safe
4051 * to take page faults.
4052 */
4053
4054 static void
pmc_post_callchain_callback(void)4055 pmc_post_callchain_callback(void)
4056 {
4057 struct thread *td;
4058
4059 td = curthread;
4060
4061 /*
4062 * If there is multiple PMCs for the same interrupt ignore new post
4063 */
4064 if (td->td_pflags & TDP_CALLCHAIN)
4065 return;
4066
4067 /*
4068 * Mark this thread as needing callchain capture.
4069 * `td->td_pflags' will be safe to touch because this thread
4070 * was in user space when it was interrupted.
4071 */
4072 td->td_pflags |= TDP_CALLCHAIN;
4073
4074 /*
4075 * Don't let this thread migrate between CPUs until callchain
4076 * capture completes.
4077 */
4078 sched_pin();
4079
4080 return;
4081 }
4082
4083 /*
4084 * Interrupt processing.
4085 *
4086 * Find a free slot in the per-cpu array of samples and capture the
4087 * current callchain there. If a sample was successfully added, a bit
4088 * is set in mask 'pmc_cpumask' denoting that the DO_SAMPLES hook
4089 * needs to be invoked from the clock handler.
4090 *
4091 * This function is meant to be called from an NMI handler. It cannot
4092 * use any of the locking primitives supplied by the OS.
4093 */
4094
4095 int
pmc_process_interrupt(int cpu,int ring,struct pmc * pm,struct trapframe * tf,int inuserspace)4096 pmc_process_interrupt(int cpu, int ring, struct pmc *pm, struct trapframe *tf,
4097 int inuserspace)
4098 {
4099 int error, callchaindepth;
4100 struct thread *td;
4101 struct pmc_sample *ps;
4102 struct pmc_samplebuffer *psb;
4103
4104 error = 0;
4105
4106 /*
4107 * Allocate space for a sample buffer.
4108 */
4109 psb = pmc_pcpu[cpu]->pc_sb[ring];
4110
4111 ps = psb->ps_write;
4112 if (ps->ps_nsamples) { /* in use, reader hasn't caught up */
4113 CPU_SET_ATOMIC(cpu, &pm->pm_stalled);
4114 atomic_add_int(&pmc_stats.pm_intr_bufferfull, 1);
4115 PMCDBG6(SAM,INT,1,"(spc) cpu=%d pm=%p tf=%p um=%d wr=%d rd=%d",
4116 cpu, pm, (void *) tf, inuserspace,
4117 (int) (psb->ps_write - psb->ps_samples),
4118 (int) (psb->ps_read - psb->ps_samples));
4119 callchaindepth = 1;
4120 error = ENOMEM;
4121 goto done;
4122 }
4123
4124
4125 /* Fill in entry. */
4126 PMCDBG6(SAM,INT,1,"cpu=%d pm=%p tf=%p um=%d wr=%d rd=%d", cpu, pm,
4127 (void *) tf, inuserspace,
4128 (int) (psb->ps_write - psb->ps_samples),
4129 (int) (psb->ps_read - psb->ps_samples));
4130
4131 KASSERT(pm->pm_runcount >= 0,
4132 ("[pmc,%d] pm=%p runcount %d", __LINE__, (void *) pm,
4133 pm->pm_runcount));
4134
4135 atomic_add_rel_int(&pm->pm_runcount, 1); /* hold onto PMC */
4136
4137 ps->ps_pmc = pm;
4138 if ((td = curthread) && td->td_proc)
4139 ps->ps_pid = td->td_proc->p_pid;
4140 else
4141 ps->ps_pid = -1;
4142 ps->ps_cpu = cpu;
4143 ps->ps_td = td;
4144 ps->ps_flags = inuserspace ? PMC_CC_F_USERSPACE : 0;
4145
4146 callchaindepth = (pm->pm_flags & PMC_F_CALLCHAIN) ?
4147 pmc_callchaindepth : 1;
4148
4149 if (callchaindepth == 1)
4150 ps->ps_pc[0] = PMC_TRAPFRAME_TO_PC(tf);
4151 else {
4152 /*
4153 * Kernel stack traversals can be done immediately,
4154 * while we defer to an AST for user space traversals.
4155 */
4156 if (!inuserspace) {
4157 callchaindepth =
4158 pmc_save_kernel_callchain(ps->ps_pc,
4159 callchaindepth, tf);
4160 } else {
4161 pmc_post_callchain_callback();
4162 callchaindepth = PMC_SAMPLE_INUSE;
4163 }
4164 }
4165
4166 ps->ps_nsamples = callchaindepth; /* mark entry as in use */
4167
4168 /* increment write pointer, modulo ring buffer size */
4169 ps++;
4170 if (ps == psb->ps_fence)
4171 psb->ps_write = psb->ps_samples;
4172 else
4173 psb->ps_write = ps;
4174
4175 done:
4176 /* mark CPU as needing processing */
4177 if (callchaindepth != PMC_SAMPLE_INUSE)
4178 CPU_SET_ATOMIC(cpu, &pmc_cpumask);
4179
4180 return (error);
4181 }
4182
4183 /*
4184 * Capture a user call chain. This function will be called from ast()
4185 * before control returns to userland and before the process gets
4186 * rescheduled.
4187 */
4188
4189 static void
pmc_capture_user_callchain(int cpu,int ring,struct trapframe * tf)4190 pmc_capture_user_callchain(int cpu, int ring, struct trapframe *tf)
4191 {
4192 struct pmc *pm;
4193 struct thread *td;
4194 struct pmc_sample *ps, *ps_end;
4195 struct pmc_samplebuffer *psb;
4196 #ifdef INVARIANTS
4197 int ncallchains;
4198 #endif
4199
4200 psb = pmc_pcpu[cpu]->pc_sb[ring];
4201 td = curthread;
4202
4203 KASSERT(td->td_pflags & TDP_CALLCHAIN,
4204 ("[pmc,%d] Retrieving callchain for thread that doesn't want it",
4205 __LINE__));
4206
4207 #ifdef INVARIANTS
4208 ncallchains = 0;
4209 #endif
4210
4211 /*
4212 * Iterate through all deferred callchain requests.
4213 * Walk from the current read pointer to the current
4214 * write pointer.
4215 */
4216
4217 ps = psb->ps_read;
4218 ps_end = psb->ps_write;
4219 do {
4220 if (ps->ps_nsamples != PMC_SAMPLE_INUSE)
4221 goto next;
4222 if (ps->ps_td != td)
4223 goto next;
4224
4225 KASSERT(ps->ps_cpu == cpu,
4226 ("[pmc,%d] cpu mismatch ps_cpu=%d pcpu=%d", __LINE__,
4227 ps->ps_cpu, PCPU_GET(cpuid)));
4228
4229 pm = ps->ps_pmc;
4230
4231 KASSERT(pm->pm_flags & PMC_F_CALLCHAIN,
4232 ("[pmc,%d] Retrieving callchain for PMC that doesn't "
4233 "want it", __LINE__));
4234
4235 KASSERT(pm->pm_runcount > 0,
4236 ("[pmc,%d] runcount %d", __LINE__, pm->pm_runcount));
4237
4238 /*
4239 * Retrieve the callchain and mark the sample buffer
4240 * as 'processable' by the timer tick sweep code.
4241 */
4242 ps->ps_nsamples = pmc_save_user_callchain(ps->ps_pc,
4243 pmc_callchaindepth, tf);
4244
4245 #ifdef INVARIANTS
4246 ncallchains++;
4247 #endif
4248
4249 next:
4250 /* increment the pointer, modulo sample ring size */
4251 if (++ps == psb->ps_fence)
4252 ps = psb->ps_samples;
4253 } while (ps != ps_end);
4254
4255 KASSERT(ncallchains > 0,
4256 ("[pmc,%d] cpu %d didn't find a sample to collect", __LINE__,
4257 cpu));
4258
4259 KASSERT(td->td_pinned == 1,
4260 ("[pmc,%d] invalid td_pinned value", __LINE__));
4261 sched_unpin(); /* Can migrate safely now. */
4262
4263 /* mark CPU as needing processing */
4264 CPU_SET_ATOMIC(cpu, &pmc_cpumask);
4265
4266 return;
4267 }
4268
4269 /*
4270 * Process saved PC samples.
4271 */
4272
4273 static void
pmc_process_samples(int cpu,int ring)4274 pmc_process_samples(int cpu, int ring)
4275 {
4276 struct pmc *pm;
4277 int adjri, n;
4278 struct thread *td;
4279 struct pmc_owner *po;
4280 struct pmc_sample *ps;
4281 struct pmc_classdep *pcd;
4282 struct pmc_samplebuffer *psb;
4283
4284 KASSERT(PCPU_GET(cpuid) == cpu,
4285 ("[pmc,%d] not on the correct CPU pcpu=%d cpu=%d", __LINE__,
4286 PCPU_GET(cpuid), cpu));
4287
4288 psb = pmc_pcpu[cpu]->pc_sb[ring];
4289
4290 for (n = 0; n < pmc_nsamples; n++) { /* bound on #iterations */
4291
4292 ps = psb->ps_read;
4293 if (ps->ps_nsamples == PMC_SAMPLE_FREE)
4294 break;
4295
4296 pm = ps->ps_pmc;
4297
4298 KASSERT(pm->pm_runcount > 0,
4299 ("[pmc,%d] pm=%p runcount %d", __LINE__, (void *) pm,
4300 pm->pm_runcount));
4301
4302 po = pm->pm_owner;
4303
4304 KASSERT(PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)),
4305 ("[pmc,%d] pmc=%p non-sampling mode=%d", __LINE__,
4306 pm, PMC_TO_MODE(pm)));
4307
4308 /* Ignore PMCs that have been switched off */
4309 if (pm->pm_state != PMC_STATE_RUNNING)
4310 goto entrydone;
4311
4312 /* If there is a pending AST wait for completion */
4313 if (ps->ps_nsamples == PMC_SAMPLE_INUSE) {
4314 /* Need a rescan at a later time. */
4315 CPU_SET_ATOMIC(cpu, &pmc_cpumask);
4316 break;
4317 }
4318
4319 PMCDBG6(SAM,OPS,1,"cpu=%d pm=%p n=%d fl=%x wr=%d rd=%d", cpu,
4320 pm, ps->ps_nsamples, ps->ps_flags,
4321 (int) (psb->ps_write - psb->ps_samples),
4322 (int) (psb->ps_read - psb->ps_samples));
4323
4324 /*
4325 * If this is a process-mode PMC that is attached to
4326 * its owner, and if the PC is in user mode, update
4327 * profiling statistics like timer-based profiling
4328 * would have done.
4329 */
4330 if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) {
4331 if (ps->ps_flags & PMC_CC_F_USERSPACE) {
4332 td = FIRST_THREAD_IN_PROC(po->po_owner);
4333 addupc_intr(td, ps->ps_pc[0], 1);
4334 }
4335 goto entrydone;
4336 }
4337
4338 /*
4339 * Otherwise, this is either a sampling mode PMC that
4340 * is attached to a different process than its owner,
4341 * or a system-wide sampling PMC. Dispatch a log
4342 * entry to the PMC's owner process.
4343 */
4344 pmclog_process_callchain(pm, ps);
4345
4346 entrydone:
4347 ps->ps_nsamples = 0; /* mark entry as free */
4348 atomic_subtract_rel_int(&pm->pm_runcount, 1);
4349
4350 /* increment read pointer, modulo sample size */
4351 if (++ps == psb->ps_fence)
4352 psb->ps_read = psb->ps_samples;
4353 else
4354 psb->ps_read = ps;
4355 }
4356
4357 atomic_add_int(&pmc_stats.pm_log_sweeps, 1);
4358
4359 /* Do not re-enable stalled PMCs if we failed to process any samples */
4360 if (n == 0)
4361 return;
4362
4363 /*
4364 * Restart any stalled sampling PMCs on this CPU.
4365 *
4366 * If the NMI handler sets the pm_stalled field of a PMC after
4367 * the check below, we'll end up processing the stalled PMC at
4368 * the next hardclock tick.
4369 */
4370 for (n = 0; n < md->pmd_npmc; n++) {
4371 pcd = pmc_ri_to_classdep(md, n, &adjri);
4372 KASSERT(pcd != NULL,
4373 ("[pmc,%d] null pcd ri=%d", __LINE__, n));
4374 (void) (*pcd->pcd_get_config)(cpu,adjri,&pm);
4375
4376 if (pm == NULL || /* !cfg'ed */
4377 pm->pm_state != PMC_STATE_RUNNING || /* !active */
4378 !PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)) || /* !sampling */
4379 !CPU_ISSET(cpu, &pm->pm_cpustate) || /* !desired */
4380 !CPU_ISSET(cpu, &pm->pm_stalled)) /* !stalled */
4381 continue;
4382
4383 CPU_CLR_ATOMIC(cpu, &pm->pm_stalled);
4384 (*pcd->pcd_start_pmc)(cpu, adjri);
4385 }
4386 }
4387
4388 /*
4389 * Event handlers.
4390 */
4391
4392 /*
4393 * Handle a process exit.
4394 *
4395 * Remove this process from all hash tables. If this process
4396 * owned any PMCs, turn off those PMCs and deallocate them,
4397 * removing any associations with target processes.
4398 *
4399 * This function will be called by the last 'thread' of a
4400 * process.
4401 *
4402 * XXX This eventhandler gets called early in the exit process.
4403 * Consider using a 'hook' invocation from thread_exit() or equivalent
4404 * spot. Another negative is that kse_exit doesn't seem to call
4405 * exit1() [??].
4406 *
4407 */
4408
4409 static void
pmc_process_exit(void * arg __unused,struct proc * p)4410 pmc_process_exit(void *arg __unused, struct proc *p)
4411 {
4412 struct pmc *pm;
4413 int adjri, cpu;
4414 unsigned int ri;
4415 int is_using_hwpmcs;
4416 struct pmc_owner *po;
4417 struct pmc_process *pp;
4418 struct pmc_classdep *pcd;
4419 pmc_value_t newvalue, tmp;
4420
4421 PROC_LOCK(p);
4422 is_using_hwpmcs = p->p_flag & P_HWPMC;
4423 PROC_UNLOCK(p);
4424
4425 /*
4426 * Log a sysexit event to all SS PMC owners.
4427 */
4428 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext)
4429 if (po->po_flags & PMC_PO_OWNS_LOGFILE)
4430 pmclog_process_sysexit(po, p->p_pid);
4431
4432 if (!is_using_hwpmcs)
4433 return;
4434
4435 PMC_GET_SX_XLOCK();
4436 PMCDBG3(PRC,EXT,1,"process-exit proc=%p (%d, %s)", p, p->p_pid,
4437 p->p_comm);
4438
4439 /*
4440 * Since this code is invoked by the last thread in an exiting
4441 * process, we would have context switched IN at some prior
4442 * point. However, with PREEMPTION, kernel mode context
4443 * switches may happen any time, so we want to disable a
4444 * context switch OUT till we get any PMCs targetting this
4445 * process off the hardware.
4446 *
4447 * We also need to atomically remove this process'
4448 * entry from our target process hash table, using
4449 * PMC_FLAG_REMOVE.
4450 */
4451 PMCDBG3(PRC,EXT,1, "process-exit proc=%p (%d, %s)", p, p->p_pid,
4452 p->p_comm);
4453
4454 critical_enter(); /* no preemption */
4455
4456 cpu = curthread->td_oncpu;
4457
4458 if ((pp = pmc_find_process_descriptor(p,
4459 PMC_FLAG_REMOVE)) != NULL) {
4460
4461 PMCDBG2(PRC,EXT,2,
4462 "process-exit proc=%p pmc-process=%p", p, pp);
4463
4464 /*
4465 * The exiting process could the target of
4466 * some PMCs which will be running on
4467 * currently executing CPU.
4468 *
4469 * We need to turn these PMCs off like we
4470 * would do at context switch OUT time.
4471 */
4472 for (ri = 0; ri < md->pmd_npmc; ri++) {
4473
4474 /*
4475 * Pick up the pmc pointer from hardware
4476 * state similar to the CSW_OUT code.
4477 */
4478 pm = NULL;
4479
4480 pcd = pmc_ri_to_classdep(md, ri, &adjri);
4481
4482 (void) (*pcd->pcd_get_config)(cpu, adjri, &pm);
4483
4484 PMCDBG2(PRC,EXT,2, "ri=%d pm=%p", ri, pm);
4485
4486 if (pm == NULL ||
4487 !PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)))
4488 continue;
4489
4490 PMCDBG4(PRC,EXT,2, "ppmcs[%d]=%p pm=%p "
4491 "state=%d", ri, pp->pp_pmcs[ri].pp_pmc,
4492 pm, pm->pm_state);
4493
4494 KASSERT(PMC_TO_ROWINDEX(pm) == ri,
4495 ("[pmc,%d] ri mismatch pmc(%d) ri(%d)",
4496 __LINE__, PMC_TO_ROWINDEX(pm), ri));
4497
4498 KASSERT(pm == pp->pp_pmcs[ri].pp_pmc,
4499 ("[pmc,%d] pm %p != pp_pmcs[%d] %p",
4500 __LINE__, pm, ri, pp->pp_pmcs[ri].pp_pmc));
4501
4502 KASSERT(pm->pm_runcount > 0,
4503 ("[pmc,%d] bad runcount ri %d rc %d",
4504 __LINE__, ri, pm->pm_runcount));
4505
4506 /*
4507 * Change desired state, and then stop if not
4508 * stalled. This two-step dance should avoid
4509 * race conditions where an interrupt re-enables
4510 * the PMC after this code has already checked
4511 * the pm_stalled flag.
4512 */
4513 if (CPU_ISSET(cpu, &pm->pm_cpustate)) {
4514 CPU_CLR_ATOMIC(cpu, &pm->pm_cpustate);
4515 if (!CPU_ISSET(cpu, &pm->pm_stalled)) {
4516 (void) pcd->pcd_stop_pmc(cpu, adjri);
4517 pcd->pcd_read_pmc(cpu, adjri,
4518 &newvalue);
4519 tmp = newvalue -
4520 PMC_PCPU_SAVED(cpu,ri);
4521
4522 mtx_pool_lock_spin(pmc_mtxpool, pm);
4523 pm->pm_gv.pm_savedvalue += tmp;
4524 pp->pp_pmcs[ri].pp_pmcval += tmp;
4525 mtx_pool_unlock_spin(pmc_mtxpool, pm);
4526 }
4527 }
4528
4529 atomic_subtract_rel_int(&pm->pm_runcount,1);
4530
4531 KASSERT((int) pm->pm_runcount >= 0,
4532 ("[pmc,%d] runcount is %d", __LINE__, ri));
4533
4534 (void) pcd->pcd_config_pmc(cpu, adjri, NULL);
4535 }
4536
4537 /*
4538 * Inform the MD layer of this pseudo "context switch
4539 * out"
4540 */
4541 (void) md->pmd_switch_out(pmc_pcpu[cpu], pp);
4542
4543 critical_exit(); /* ok to be pre-empted now */
4544
4545 /*
4546 * Unlink this process from the PMCs that are
4547 * targetting it. This will send a signal to
4548 * all PMC owner's whose PMCs are orphaned.
4549 *
4550 * Log PMC value at exit time if requested.
4551 */
4552 for (ri = 0; ri < md->pmd_npmc; ri++)
4553 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) {
4554 if (pm->pm_flags & PMC_F_NEEDS_LOGFILE &&
4555 PMC_IS_COUNTING_MODE(PMC_TO_MODE(pm)))
4556 pmclog_process_procexit(pm, pp);
4557 pmc_unlink_target_process(pm, pp);
4558 }
4559 free(pp, M_PMC);
4560
4561 } else
4562 critical_exit(); /* pp == NULL */
4563
4564
4565 /*
4566 * If the process owned PMCs, free them up and free up
4567 * memory.
4568 */
4569 if ((po = pmc_find_owner_descriptor(p)) != NULL) {
4570 pmc_remove_owner(po);
4571 pmc_destroy_owner_descriptor(po);
4572 }
4573
4574 sx_xunlock(&pmc_sx);
4575 }
4576
4577 /*
4578 * Handle a process fork.
4579 *
4580 * If the parent process 'p1' is under HWPMC monitoring, then copy
4581 * over any attached PMCs that have 'do_descendants' semantics.
4582 */
4583
4584 static void
pmc_process_fork(void * arg __unused,struct proc * p1,struct proc * newproc,int flags)4585 pmc_process_fork(void *arg __unused, struct proc *p1, struct proc *newproc,
4586 int flags)
4587 {
4588 int is_using_hwpmcs;
4589 unsigned int ri;
4590 uint32_t do_descendants;
4591 struct pmc *pm;
4592 struct pmc_owner *po;
4593 struct pmc_process *ppnew, *ppold;
4594
4595 (void) flags; /* unused parameter */
4596
4597 PROC_LOCK(p1);
4598 is_using_hwpmcs = p1->p_flag & P_HWPMC;
4599 PROC_UNLOCK(p1);
4600
4601 /*
4602 * If there are system-wide sampling PMCs active, we need to
4603 * log all fork events to their owner's logs.
4604 */
4605
4606 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext)
4607 if (po->po_flags & PMC_PO_OWNS_LOGFILE)
4608 pmclog_process_procfork(po, p1->p_pid, newproc->p_pid);
4609
4610 if (!is_using_hwpmcs)
4611 return;
4612
4613 PMC_GET_SX_XLOCK();
4614 PMCDBG4(PMC,FRK,1, "process-fork proc=%p (%d, %s) -> %p", p1,
4615 p1->p_pid, p1->p_comm, newproc);
4616
4617 /*
4618 * If the parent process (curthread->td_proc) is a
4619 * target of any PMCs, look for PMCs that are to be
4620 * inherited, and link these into the new process
4621 * descriptor.
4622 */
4623 if ((ppold = pmc_find_process_descriptor(curthread->td_proc,
4624 PMC_FLAG_NONE)) == NULL)
4625 goto done; /* nothing to do */
4626
4627 do_descendants = 0;
4628 for (ri = 0; ri < md->pmd_npmc; ri++)
4629 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL)
4630 do_descendants |= pm->pm_flags & PMC_F_DESCENDANTS;
4631 if (do_descendants == 0) /* nothing to do */
4632 goto done;
4633
4634 /* allocate a descriptor for the new process */
4635 if ((ppnew = pmc_find_process_descriptor(newproc,
4636 PMC_FLAG_ALLOCATE)) == NULL)
4637 goto done;
4638
4639 /*
4640 * Run through all PMCs that were targeting the old process
4641 * and which specified F_DESCENDANTS and attach them to the
4642 * new process.
4643 *
4644 * Log the fork event to all owners of PMCs attached to this
4645 * process, if not already logged.
4646 */
4647 for (ri = 0; ri < md->pmd_npmc; ri++)
4648 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL &&
4649 (pm->pm_flags & PMC_F_DESCENDANTS)) {
4650 pmc_link_target_process(pm, ppnew);
4651 po = pm->pm_owner;
4652 if (po->po_sscount == 0 &&
4653 po->po_flags & PMC_PO_OWNS_LOGFILE)
4654 pmclog_process_procfork(po, p1->p_pid,
4655 newproc->p_pid);
4656 }
4657
4658 /*
4659 * Now mark the new process as being tracked by this driver.
4660 */
4661 PROC_LOCK(newproc);
4662 newproc->p_flag |= P_HWPMC;
4663 PROC_UNLOCK(newproc);
4664
4665 done:
4666 sx_xunlock(&pmc_sx);
4667 }
4668
4669 static void
pmc_kld_load(void * arg __unused,linker_file_t lf)4670 pmc_kld_load(void *arg __unused, linker_file_t lf)
4671 {
4672 struct pmc_owner *po;
4673
4674 sx_slock(&pmc_sx);
4675
4676 /*
4677 * Notify owners of system sampling PMCs about KLD operations.
4678 */
4679 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext)
4680 if (po->po_flags & PMC_PO_OWNS_LOGFILE)
4681 pmclog_process_map_in(po, (pid_t) -1,
4682 (uintfptr_t) lf->address, lf->filename);
4683
4684 /*
4685 * TODO: Notify owners of (all) process-sampling PMCs too.
4686 */
4687
4688 sx_sunlock(&pmc_sx);
4689 }
4690
4691 static void
pmc_kld_unload(void * arg __unused,const char * filename __unused,caddr_t address,size_t size)4692 pmc_kld_unload(void *arg __unused, const char *filename __unused,
4693 caddr_t address, size_t size)
4694 {
4695 struct pmc_owner *po;
4696
4697 sx_slock(&pmc_sx);
4698
4699 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext)
4700 if (po->po_flags & PMC_PO_OWNS_LOGFILE)
4701 pmclog_process_map_out(po, (pid_t) -1,
4702 (uintfptr_t) address, (uintfptr_t) address + size);
4703
4704 /*
4705 * TODO: Notify owners of process-sampling PMCs.
4706 */
4707
4708 sx_sunlock(&pmc_sx);
4709 }
4710
4711 /*
4712 * initialization
4713 */
4714 static const char *
pmc_name_of_pmcclass(enum pmc_class class)4715 pmc_name_of_pmcclass(enum pmc_class class)
4716 {
4717
4718 switch (class) {
4719 #undef __PMC_CLASS
4720 #define __PMC_CLASS(S,V,D) \
4721 case PMC_CLASS_##S: \
4722 return #S;
4723 __PMC_CLASSES();
4724 default:
4725 return ("<unknown>");
4726 }
4727 }
4728
4729 /*
4730 * Base class initializer: allocate structure and set default classes.
4731 */
4732 struct pmc_mdep *
pmc_mdep_alloc(int nclasses)4733 pmc_mdep_alloc(int nclasses)
4734 {
4735 struct pmc_mdep *md;
4736 int n;
4737
4738 /* SOFT + md classes */
4739 n = 1 + nclasses;
4740 md = malloc(sizeof(struct pmc_mdep) + n *
4741 sizeof(struct pmc_classdep), M_PMC, M_WAITOK|M_ZERO);
4742 md->pmd_nclass = n;
4743
4744 /* Add base class. */
4745 pmc_soft_initialize(md);
4746 return md;
4747 }
4748
4749 void
pmc_mdep_free(struct pmc_mdep * md)4750 pmc_mdep_free(struct pmc_mdep *md)
4751 {
4752 pmc_soft_finalize(md);
4753 free(md, M_PMC);
4754 }
4755
4756 static int
generic_switch_in(struct pmc_cpu * pc,struct pmc_process * pp)4757 generic_switch_in(struct pmc_cpu *pc, struct pmc_process *pp)
4758 {
4759 (void) pc; (void) pp;
4760
4761 return (0);
4762 }
4763
4764 static int
generic_switch_out(struct pmc_cpu * pc,struct pmc_process * pp)4765 generic_switch_out(struct pmc_cpu *pc, struct pmc_process *pp)
4766 {
4767 (void) pc; (void) pp;
4768
4769 return (0);
4770 }
4771
4772 static struct pmc_mdep *
pmc_generic_cpu_initialize(void)4773 pmc_generic_cpu_initialize(void)
4774 {
4775 struct pmc_mdep *md;
4776
4777 md = pmc_mdep_alloc(0);
4778
4779 md->pmd_cputype = PMC_CPU_GENERIC;
4780
4781 md->pmd_pcpu_init = NULL;
4782 md->pmd_pcpu_fini = NULL;
4783 md->pmd_switch_in = generic_switch_in;
4784 md->pmd_switch_out = generic_switch_out;
4785
4786 return (md);
4787 }
4788
4789 static void
pmc_generic_cpu_finalize(struct pmc_mdep * md)4790 pmc_generic_cpu_finalize(struct pmc_mdep *md)
4791 {
4792 (void) md;
4793 }
4794
4795
4796 static int
pmc_initialize(void)4797 pmc_initialize(void)
4798 {
4799 int c, cpu, error, n, ri;
4800 unsigned int maxcpu;
4801 struct pmc_binding pb;
4802 struct pmc_sample *ps;
4803 struct pmc_classdep *pcd;
4804 struct pmc_samplebuffer *sb;
4805
4806 md = NULL;
4807 error = 0;
4808
4809 #ifdef HWPMC_DEBUG
4810 /* parse debug flags first */
4811 if (TUNABLE_STR_FETCH(PMC_SYSCTL_NAME_PREFIX "debugflags",
4812 pmc_debugstr, sizeof(pmc_debugstr)))
4813 pmc_debugflags_parse(pmc_debugstr,
4814 pmc_debugstr+strlen(pmc_debugstr));
4815 #endif
4816
4817 PMCDBG1(MOD,INI,0, "PMC Initialize (version %x)", PMC_VERSION);
4818
4819 /* check kernel version */
4820 if (pmc_kernel_version != PMC_VERSION) {
4821 if (pmc_kernel_version == 0)
4822 printf("hwpmc: this kernel has not been compiled with "
4823 "'options HWPMC_HOOKS'.\n");
4824 else
4825 printf("hwpmc: kernel version (0x%x) does not match "
4826 "module version (0x%x).\n", pmc_kernel_version,
4827 PMC_VERSION);
4828 return EPROGMISMATCH;
4829 }
4830
4831 /*
4832 * check sysctl parameters
4833 */
4834
4835 if (pmc_hashsize <= 0) {
4836 (void) printf("hwpmc: tunable \"hashsize\"=%d must be "
4837 "greater than zero.\n", pmc_hashsize);
4838 pmc_hashsize = PMC_HASH_SIZE;
4839 }
4840
4841 if (pmc_nsamples <= 0 || pmc_nsamples > 65535) {
4842 (void) printf("hwpmc: tunable \"nsamples\"=%d out of "
4843 "range.\n", pmc_nsamples);
4844 pmc_nsamples = PMC_NSAMPLES;
4845 }
4846
4847 if (pmc_callchaindepth <= 0 ||
4848 pmc_callchaindepth > PMC_CALLCHAIN_DEPTH_MAX) {
4849 (void) printf("hwpmc: tunable \"callchaindepth\"=%d out of "
4850 "range - using %d.\n", pmc_callchaindepth,
4851 PMC_CALLCHAIN_DEPTH_MAX);
4852 pmc_callchaindepth = PMC_CALLCHAIN_DEPTH_MAX;
4853 }
4854
4855 md = pmc_md_initialize();
4856 if (md == NULL) {
4857 /* Default to generic CPU. */
4858 md = pmc_generic_cpu_initialize();
4859 if (md == NULL)
4860 return (ENOSYS);
4861 }
4862
4863 KASSERT(md->pmd_nclass >= 1 && md->pmd_npmc >= 1,
4864 ("[pmc,%d] no classes or pmcs", __LINE__));
4865
4866 /* Compute the map from row-indices to classdep pointers. */
4867 pmc_rowindex_to_classdep = malloc(sizeof(struct pmc_classdep *) *
4868 md->pmd_npmc, M_PMC, M_WAITOK|M_ZERO);
4869
4870 for (n = 0; n < md->pmd_npmc; n++)
4871 pmc_rowindex_to_classdep[n] = NULL;
4872 for (ri = c = 0; c < md->pmd_nclass; c++) {
4873 pcd = &md->pmd_classdep[c];
4874 for (n = 0; n < pcd->pcd_num; n++, ri++)
4875 pmc_rowindex_to_classdep[ri] = pcd;
4876 }
4877
4878 KASSERT(ri == md->pmd_npmc,
4879 ("[pmc,%d] npmc miscomputed: ri=%d, md->npmc=%d", __LINE__,
4880 ri, md->pmd_npmc));
4881
4882 maxcpu = pmc_cpu_max();
4883
4884 /* allocate space for the per-cpu array */
4885 pmc_pcpu = malloc(maxcpu * sizeof(struct pmc_cpu *), M_PMC,
4886 M_WAITOK|M_ZERO);
4887
4888 /* per-cpu 'saved values' for managing process-mode PMCs */
4889 pmc_pcpu_saved = malloc(sizeof(pmc_value_t) * maxcpu * md->pmd_npmc,
4890 M_PMC, M_WAITOK);
4891
4892 /* Perform CPU-dependent initialization. */
4893 pmc_save_cpu_binding(&pb);
4894 error = 0;
4895 for (cpu = 0; error == 0 && cpu < maxcpu; cpu++) {
4896 if (!pmc_cpu_is_active(cpu))
4897 continue;
4898 pmc_select_cpu(cpu);
4899 pmc_pcpu[cpu] = malloc(sizeof(struct pmc_cpu) +
4900 md->pmd_npmc * sizeof(struct pmc_hw *), M_PMC,
4901 M_WAITOK|M_ZERO);
4902 if (md->pmd_pcpu_init)
4903 error = md->pmd_pcpu_init(md, cpu);
4904 for (n = 0; error == 0 && n < md->pmd_nclass; n++)
4905 error = md->pmd_classdep[n].pcd_pcpu_init(md, cpu);
4906 }
4907 pmc_restore_cpu_binding(&pb);
4908
4909 if (error)
4910 return (error);
4911
4912 /* allocate space for the sample array */
4913 for (cpu = 0; cpu < maxcpu; cpu++) {
4914 if (!pmc_cpu_is_active(cpu))
4915 continue;
4916
4917 sb = malloc(sizeof(struct pmc_samplebuffer) +
4918 pmc_nsamples * sizeof(struct pmc_sample), M_PMC,
4919 M_WAITOK|M_ZERO);
4920 sb->ps_read = sb->ps_write = sb->ps_samples;
4921 sb->ps_fence = sb->ps_samples + pmc_nsamples;
4922
4923 KASSERT(pmc_pcpu[cpu] != NULL,
4924 ("[pmc,%d] cpu=%d Null per-cpu data", __LINE__, cpu));
4925
4926 sb->ps_callchains = malloc(pmc_callchaindepth * pmc_nsamples *
4927 sizeof(uintptr_t), M_PMC, M_WAITOK|M_ZERO);
4928
4929 for (n = 0, ps = sb->ps_samples; n < pmc_nsamples; n++, ps++)
4930 ps->ps_pc = sb->ps_callchains +
4931 (n * pmc_callchaindepth);
4932
4933 pmc_pcpu[cpu]->pc_sb[PMC_HR] = sb;
4934
4935 sb = malloc(sizeof(struct pmc_samplebuffer) +
4936 pmc_nsamples * sizeof(struct pmc_sample), M_PMC,
4937 M_WAITOK|M_ZERO);
4938 sb->ps_read = sb->ps_write = sb->ps_samples;
4939 sb->ps_fence = sb->ps_samples + pmc_nsamples;
4940
4941 KASSERT(pmc_pcpu[cpu] != NULL,
4942 ("[pmc,%d] cpu=%d Null per-cpu data", __LINE__, cpu));
4943
4944 sb->ps_callchains = malloc(pmc_callchaindepth * pmc_nsamples *
4945 sizeof(uintptr_t), M_PMC, M_WAITOK|M_ZERO);
4946
4947 for (n = 0, ps = sb->ps_samples; n < pmc_nsamples; n++, ps++)
4948 ps->ps_pc = sb->ps_callchains +
4949 (n * pmc_callchaindepth);
4950
4951 pmc_pcpu[cpu]->pc_sb[PMC_SR] = sb;
4952 }
4953
4954 /* allocate space for the row disposition array */
4955 pmc_pmcdisp = malloc(sizeof(enum pmc_mode) * md->pmd_npmc,
4956 M_PMC, M_WAITOK|M_ZERO);
4957
4958 /* mark all PMCs as available */
4959 for (n = 0; n < (int) md->pmd_npmc; n++)
4960 PMC_MARK_ROW_FREE(n);
4961
4962 /* allocate thread hash tables */
4963 pmc_ownerhash = hashinit(pmc_hashsize, M_PMC,
4964 &pmc_ownerhashmask);
4965
4966 pmc_processhash = hashinit(pmc_hashsize, M_PMC,
4967 &pmc_processhashmask);
4968 mtx_init(&pmc_processhash_mtx, "pmc-process-hash", "pmc-leaf",
4969 MTX_SPIN);
4970
4971 LIST_INIT(&pmc_ss_owners);
4972 pmc_ss_count = 0;
4973
4974 /* allocate a pool of spin mutexes */
4975 pmc_mtxpool = mtx_pool_create("pmc-leaf", pmc_mtxpool_size,
4976 MTX_SPIN);
4977
4978 PMCDBG4(MOD,INI,1, "pmc_ownerhash=%p, mask=0x%lx "
4979 "targethash=%p mask=0x%lx", pmc_ownerhash, pmc_ownerhashmask,
4980 pmc_processhash, pmc_processhashmask);
4981
4982 /* register process {exit,fork,exec} handlers */
4983 pmc_exit_tag = EVENTHANDLER_REGISTER(process_exit,
4984 pmc_process_exit, NULL, EVENTHANDLER_PRI_ANY);
4985 pmc_fork_tag = EVENTHANDLER_REGISTER(process_fork,
4986 pmc_process_fork, NULL, EVENTHANDLER_PRI_ANY);
4987
4988 /* register kld event handlers */
4989 pmc_kld_load_tag = EVENTHANDLER_REGISTER(kld_load, pmc_kld_load,
4990 NULL, EVENTHANDLER_PRI_ANY);
4991 pmc_kld_unload_tag = EVENTHANDLER_REGISTER(kld_unload, pmc_kld_unload,
4992 NULL, EVENTHANDLER_PRI_ANY);
4993
4994 /* initialize logging */
4995 pmclog_initialize();
4996
4997 /* set hook functions */
4998 pmc_intr = md->pmd_intr;
4999 pmc_hook = pmc_hook_handler;
5000
5001 if (error == 0) {
5002 printf(PMC_MODULE_NAME ":");
5003 for (n = 0; n < (int) md->pmd_nclass; n++) {
5004 pcd = &md->pmd_classdep[n];
5005 printf(" %s/%d/%d/0x%b",
5006 pmc_name_of_pmcclass(pcd->pcd_class),
5007 pcd->pcd_num,
5008 pcd->pcd_width,
5009 pcd->pcd_caps,
5010 "\20"
5011 "\1INT\2USR\3SYS\4EDG\5THR"
5012 "\6REA\7WRI\10INV\11QUA\12PRC"
5013 "\13TAG\14CSC");
5014 }
5015 printf("\n");
5016 }
5017
5018 return (error);
5019 }
5020
5021 /* prepare to be unloaded */
5022 static void
pmc_cleanup(void)5023 pmc_cleanup(void)
5024 {
5025 int c, cpu;
5026 unsigned int maxcpu;
5027 struct pmc_ownerhash *ph;
5028 struct pmc_owner *po, *tmp;
5029 struct pmc_binding pb;
5030 #ifdef HWPMC_DEBUG
5031 struct pmc_processhash *prh;
5032 #endif
5033
5034 PMCDBG0(MOD,INI,0, "cleanup");
5035
5036 /* switch off sampling */
5037 CPU_ZERO(&pmc_cpumask);
5038 pmc_intr = NULL;
5039
5040 sx_xlock(&pmc_sx);
5041 if (pmc_hook == NULL) { /* being unloaded already */
5042 sx_xunlock(&pmc_sx);
5043 return;
5044 }
5045
5046 pmc_hook = NULL; /* prevent new threads from entering module */
5047
5048 /* deregister event handlers */
5049 EVENTHANDLER_DEREGISTER(process_fork, pmc_fork_tag);
5050 EVENTHANDLER_DEREGISTER(process_exit, pmc_exit_tag);
5051 EVENTHANDLER_DEREGISTER(kld_load, pmc_kld_load_tag);
5052 EVENTHANDLER_DEREGISTER(kld_unload, pmc_kld_unload_tag);
5053
5054 /* send SIGBUS to all owner threads, free up allocations */
5055 if (pmc_ownerhash)
5056 for (ph = pmc_ownerhash;
5057 ph <= &pmc_ownerhash[pmc_ownerhashmask];
5058 ph++) {
5059 LIST_FOREACH_SAFE(po, ph, po_next, tmp) {
5060 pmc_remove_owner(po);
5061
5062 /* send SIGBUS to owner processes */
5063 PMCDBG3(MOD,INI,2, "cleanup signal proc=%p "
5064 "(%d, %s)", po->po_owner,
5065 po->po_owner->p_pid,
5066 po->po_owner->p_comm);
5067
5068 PROC_LOCK(po->po_owner);
5069 kern_psignal(po->po_owner, SIGBUS);
5070 PROC_UNLOCK(po->po_owner);
5071
5072 pmc_destroy_owner_descriptor(po);
5073 }
5074 }
5075
5076 /* reclaim allocated data structures */
5077 if (pmc_mtxpool)
5078 mtx_pool_destroy(&pmc_mtxpool);
5079
5080 mtx_destroy(&pmc_processhash_mtx);
5081 if (pmc_processhash) {
5082 #ifdef HWPMC_DEBUG
5083 struct pmc_process *pp;
5084
5085 PMCDBG0(MOD,INI,3, "destroy process hash");
5086 for (prh = pmc_processhash;
5087 prh <= &pmc_processhash[pmc_processhashmask];
5088 prh++)
5089 LIST_FOREACH(pp, prh, pp_next)
5090 PMCDBG1(MOD,INI,3, "pid=%d", pp->pp_proc->p_pid);
5091 #endif
5092
5093 hashdestroy(pmc_processhash, M_PMC, pmc_processhashmask);
5094 pmc_processhash = NULL;
5095 }
5096
5097 if (pmc_ownerhash) {
5098 PMCDBG0(MOD,INI,3, "destroy owner hash");
5099 hashdestroy(pmc_ownerhash, M_PMC, pmc_ownerhashmask);
5100 pmc_ownerhash = NULL;
5101 }
5102
5103 KASSERT(LIST_EMPTY(&pmc_ss_owners),
5104 ("[pmc,%d] Global SS owner list not empty", __LINE__));
5105 KASSERT(pmc_ss_count == 0,
5106 ("[pmc,%d] Global SS count not empty", __LINE__));
5107
5108 /* do processor and pmc-class dependent cleanup */
5109 maxcpu = pmc_cpu_max();
5110
5111 PMCDBG0(MOD,INI,3, "md cleanup");
5112 if (md) {
5113 pmc_save_cpu_binding(&pb);
5114 for (cpu = 0; cpu < maxcpu; cpu++) {
5115 PMCDBG2(MOD,INI,1,"pmc-cleanup cpu=%d pcs=%p",
5116 cpu, pmc_pcpu[cpu]);
5117 if (!pmc_cpu_is_active(cpu) || pmc_pcpu[cpu] == NULL)
5118 continue;
5119 pmc_select_cpu(cpu);
5120 for (c = 0; c < md->pmd_nclass; c++)
5121 md->pmd_classdep[c].pcd_pcpu_fini(md, cpu);
5122 if (md->pmd_pcpu_fini)
5123 md->pmd_pcpu_fini(md, cpu);
5124 }
5125
5126 if (md->pmd_cputype == PMC_CPU_GENERIC)
5127 pmc_generic_cpu_finalize(md);
5128 else
5129 pmc_md_finalize(md);
5130
5131 pmc_mdep_free(md);
5132 md = NULL;
5133 pmc_restore_cpu_binding(&pb);
5134 }
5135
5136 /* Free per-cpu descriptors. */
5137 for (cpu = 0; cpu < maxcpu; cpu++) {
5138 if (!pmc_cpu_is_active(cpu))
5139 continue;
5140 KASSERT(pmc_pcpu[cpu]->pc_sb[PMC_HR] != NULL,
5141 ("[pmc,%d] Null hw cpu sample buffer cpu=%d", __LINE__,
5142 cpu));
5143 KASSERT(pmc_pcpu[cpu]->pc_sb[PMC_SR] != NULL,
5144 ("[pmc,%d] Null sw cpu sample buffer cpu=%d", __LINE__,
5145 cpu));
5146 free(pmc_pcpu[cpu]->pc_sb[PMC_HR]->ps_callchains, M_PMC);
5147 free(pmc_pcpu[cpu]->pc_sb[PMC_HR], M_PMC);
5148 free(pmc_pcpu[cpu]->pc_sb[PMC_SR]->ps_callchains, M_PMC);
5149 free(pmc_pcpu[cpu]->pc_sb[PMC_SR], M_PMC);
5150 free(pmc_pcpu[cpu], M_PMC);
5151 }
5152
5153 free(pmc_pcpu, M_PMC);
5154 pmc_pcpu = NULL;
5155
5156 free(pmc_pcpu_saved, M_PMC);
5157 pmc_pcpu_saved = NULL;
5158
5159 if (pmc_pmcdisp) {
5160 free(pmc_pmcdisp, M_PMC);
5161 pmc_pmcdisp = NULL;
5162 }
5163
5164 if (pmc_rowindex_to_classdep) {
5165 free(pmc_rowindex_to_classdep, M_PMC);
5166 pmc_rowindex_to_classdep = NULL;
5167 }
5168
5169 pmclog_shutdown();
5170
5171 sx_xunlock(&pmc_sx); /* we are done */
5172 }
5173
5174 /*
5175 * The function called at load/unload.
5176 */
5177
5178 static int
load(struct module * module __unused,int cmd,void * arg __unused)5179 load (struct module *module __unused, int cmd, void *arg __unused)
5180 {
5181 int error;
5182
5183 error = 0;
5184
5185 switch (cmd) {
5186 case MOD_LOAD :
5187 /* initialize the subsystem */
5188 error = pmc_initialize();
5189 if (error != 0)
5190 break;
5191 PMCDBG2(MOD,INI,1, "syscall=%d maxcpu=%d",
5192 pmc_syscall_num, pmc_cpu_max());
5193 break;
5194
5195
5196 case MOD_UNLOAD :
5197 case MOD_SHUTDOWN:
5198 pmc_cleanup();
5199 PMCDBG0(MOD,INI,1, "unloaded");
5200 break;
5201
5202 default :
5203 error = EINVAL; /* XXX should panic(9) */
5204 break;
5205 }
5206
5207 return error;
5208 }
5209
5210 /* memory pool */
5211 MALLOC_DEFINE(M_PMC, "pmc", "Memory space for the PMC module");
5212