fasttrap.c revision 264434
1179193Sjb/* 2179193Sjb * CDDL HEADER START 3179193Sjb * 4179193Sjb * The contents of this file are subject to the terms of the 5179193Sjb * Common Development and Distribution License (the "License"). 6179193Sjb * You may not use this file except in compliance with the License. 7179193Sjb * 8179193Sjb * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9179193Sjb * or http://www.opensolaris.org/os/licensing. 10179193Sjb * See the License for the specific language governing permissions 11179193Sjb * and limitations under the License. 12179193Sjb * 13179193Sjb * When distributing Covered Code, include this CDDL HEADER in each 14179193Sjb * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15179193Sjb * If applicable, add the following below this CDDL HEADER, with the 16179193Sjb * fields enclosed by brackets "[]" replaced with your own identifying 17179193Sjb * information: Portions Copyright [yyyy] [name of copyright owner] 18179193Sjb * 19179193Sjb * CDDL HEADER END 20211738Srpaulo * 21211738Srpaulo * Portions Copyright 2010 The FreeBSD Foundation 22211738Srpaulo * 23211738Srpaulo * $FreeBSD: head/sys/cddl/contrib/opensolaris/uts/common/dtrace/fasttrap.c 264434 2014-04-14 00:22:42Z markj $ 24179193Sjb */ 25179193Sjb 26179193Sjb/* 27179198Sjb * Copyright 2008 Sun Microsystems, Inc. All rights reserved. 28179193Sjb * Use is subject to license terms. 29179193Sjb */ 30179193Sjb 31211738Srpaulo#if defined(sun) 32179193Sjb#pragma ident "%Z%%M% %I% %E% SMI" 33211738Srpaulo#endif 34179193Sjb 35179193Sjb#include <sys/atomic.h> 36179193Sjb#include <sys/errno.h> 37179193Sjb#include <sys/stat.h> 38179193Sjb#include <sys/modctl.h> 39179193Sjb#include <sys/conf.h> 40179193Sjb#include <sys/systm.h> 41211738Srpaulo#if defined(sun) 42179193Sjb#include <sys/ddi.h> 43211738Srpaulo#endif 44179193Sjb#include <sys/sunddi.h> 45179193Sjb#include <sys/cpuvar.h> 46179193Sjb#include <sys/kmem.h> 47211738Srpaulo#if defined(sun) 48179193Sjb#include <sys/strsubr.h> 49211738Srpaulo#endif 50179193Sjb#include <sys/fasttrap.h> 51179193Sjb#include <sys/fasttrap_impl.h> 52179193Sjb#include <sys/fasttrap_isa.h> 53179193Sjb#include <sys/dtrace.h> 54179193Sjb#include <sys/dtrace_impl.h> 55179193Sjb#include <sys/sysmacros.h> 56179193Sjb#include <sys/proc.h> 57179193Sjb#include <sys/policy.h> 58211738Srpaulo#if defined(sun) 59179193Sjb#include <util/qsort.h> 60211738Srpaulo#endif 61211738Srpaulo#include <sys/mutex.h> 62211738Srpaulo#include <sys/kernel.h> 63211738Srpaulo#if !defined(sun) 64264434Smarkj#include <sys/dtrace_bsd.h> 65264434Smarkj#include <sys/eventhandler.h> 66211738Srpaulo#include <sys/user.h> 67264434Smarkj#include <vm/vm.h> 68264434Smarkj#include <vm/pmap.h> 69264434Smarkj#include <vm/vm_map.h> 70264434Smarkj#include <vm/vm_param.h> 71211738Srpaulo#include <cddl/dev/dtrace/dtrace_cddl.h> 72211738Srpaulo#endif 73179193Sjb 74179193Sjb/* 75179193Sjb * User-Land Trap-Based Tracing 76179193Sjb * ---------------------------- 77179193Sjb * 78179193Sjb * The fasttrap provider allows DTrace consumers to instrument any user-level 79179193Sjb * instruction to gather data; this includes probes with semantic 80179193Sjb * signifigance like entry and return as well as simple offsets into the 81179193Sjb * function. While the specific techniques used are very ISA specific, the 82179193Sjb * methodology is generalizable to any architecture. 83179193Sjb * 84179193Sjb * 85179193Sjb * The General Methodology 86179193Sjb * ----------------------- 87179193Sjb * 88179193Sjb * With the primary goal of tracing every user-land instruction and the 89179193Sjb * limitation that we can't trust user space so don't want to rely on much 90179193Sjb * information there, we begin by replacing the instructions we want to trace 91179193Sjb * with trap instructions. Each instruction we overwrite is saved into a hash 92179193Sjb * table keyed by process ID and pc address. When we enter the kernel due to 93179193Sjb * this trap instruction, we need the effects of the replaced instruction to 94179193Sjb * appear to have occurred before we proceed with the user thread's 95179193Sjb * execution. 96179193Sjb * 97179193Sjb * Each user level thread is represented by a ulwp_t structure which is 98179193Sjb * always easily accessible through a register. The most basic way to produce 99179193Sjb * the effects of the instruction we replaced is to copy that instruction out 100179193Sjb * to a bit of scratch space reserved in the user thread's ulwp_t structure 101179193Sjb * (a sort of kernel-private thread local storage), set the PC to that 102179193Sjb * scratch space and single step. When we reenter the kernel after single 103179193Sjb * stepping the instruction we must then adjust the PC to point to what would 104179193Sjb * normally be the next instruction. Of course, special care must be taken 105179193Sjb * for branches and jumps, but these represent such a small fraction of any 106179193Sjb * instruction set that writing the code to emulate these in the kernel is 107179193Sjb * not too difficult. 108179193Sjb * 109179193Sjb * Return probes may require several tracepoints to trace every return site, 110179193Sjb * and, conversely, each tracepoint may activate several probes (the entry 111179193Sjb * and offset 0 probes, for example). To solve this muliplexing problem, 112179193Sjb * tracepoints contain lists of probes to activate and probes contain lists 113179193Sjb * of tracepoints to enable. If a probe is activated, it adds its ID to 114179193Sjb * existing tracepoints or creates new ones as necessary. 115179193Sjb * 116179193Sjb * Most probes are activated _before_ the instruction is executed, but return 117179193Sjb * probes are activated _after_ the effects of the last instruction of the 118179193Sjb * function are visible. Return probes must be fired _after_ we have 119179193Sjb * single-stepped the instruction whereas all other probes are fired 120179193Sjb * beforehand. 121179193Sjb * 122179193Sjb * 123179193Sjb * Lock Ordering 124179193Sjb * ------------- 125179193Sjb * 126179193Sjb * The lock ordering below -- both internally and with respect to the DTrace 127179193Sjb * framework -- is a little tricky and bears some explanation. Each provider 128179193Sjb * has a lock (ftp_mtx) that protects its members including reference counts 129179193Sjb * for enabled probes (ftp_rcount), consumers actively creating probes 130179193Sjb * (ftp_ccount) and USDT consumers (ftp_mcount); all three prevent a provider 131179193Sjb * from being freed. A provider is looked up by taking the bucket lock for the 132179193Sjb * provider hash table, and is returned with its lock held. The provider lock 133179193Sjb * may be taken in functions invoked by the DTrace framework, but may not be 134179193Sjb * held while calling functions in the DTrace framework. 135179193Sjb * 136179193Sjb * To ensure consistency over multiple calls to the DTrace framework, the 137179193Sjb * creation lock (ftp_cmtx) should be held. Naturally, the creation lock may 138179193Sjb * not be taken when holding the provider lock as that would create a cyclic 139179193Sjb * lock ordering. In situations where one would naturally take the provider 140179193Sjb * lock and then the creation lock, we instead up a reference count to prevent 141179193Sjb * the provider from disappearing, drop the provider lock, and acquire the 142179193Sjb * creation lock. 143179193Sjb * 144179193Sjb * Briefly: 145179193Sjb * bucket lock before provider lock 146179193Sjb * DTrace before provider lock 147179193Sjb * creation lock before DTrace 148179193Sjb * never hold the provider lock and creation lock simultaneously 149179193Sjb */ 150179193Sjb 151211738Srpaulostatic d_open_t fasttrap_open; 152211738Srpaulostatic d_ioctl_t fasttrap_ioctl; 153211738Srpaulo 154211738Srpaulostatic struct cdevsw fasttrap_cdevsw = { 155211738Srpaulo .d_version = D_VERSION, 156211738Srpaulo .d_open = fasttrap_open, 157211738Srpaulo .d_ioctl = fasttrap_ioctl, 158211738Srpaulo .d_name = "fasttrap", 159211738Srpaulo}; 160211738Srpaulostatic struct cdev *fasttrap_cdev; 161179193Sjbstatic dtrace_meta_provider_id_t fasttrap_meta_id; 162179193Sjb 163250953Smarkjstatic struct proc *fasttrap_cleanup_proc; 164211738Srpaulostatic struct mtx fasttrap_cleanup_mtx; 165250953Smarkjstatic uint_t fasttrap_cleanup_work, fasttrap_cleanup_drain, fasttrap_cleanup_cv; 166179193Sjb 167179193Sjb/* 168179193Sjb * Generation count on modifications to the global tracepoint lookup table. 169179193Sjb */ 170179193Sjbstatic volatile uint64_t fasttrap_mod_gen; 171179193Sjb 172179193Sjb/* 173179193Sjb * When the fasttrap provider is loaded, fasttrap_max is set to either 174179193Sjb * FASTTRAP_MAX_DEFAULT or the value for fasttrap-max-probes in the 175179193Sjb * fasttrap.conf file. Each time a probe is created, fasttrap_total is 176179193Sjb * incremented by the number of tracepoints that may be associated with that 177179193Sjb * probe; fasttrap_total is capped at fasttrap_max. 178179193Sjb */ 179179193Sjb#define FASTTRAP_MAX_DEFAULT 250000 180179193Sjbstatic uint32_t fasttrap_max; 181179193Sjbstatic uint32_t fasttrap_total; 182179193Sjb 183248983Spfg/* 184248983Spfg * Copyright (c) 2011, Joyent, Inc. All rights reserved. 185248983Spfg */ 186179193Sjb 187179193Sjb#define FASTTRAP_TPOINTS_DEFAULT_SIZE 0x4000 188179193Sjb#define FASTTRAP_PROVIDERS_DEFAULT_SIZE 0x100 189179193Sjb#define FASTTRAP_PROCS_DEFAULT_SIZE 0x100 190179193Sjb 191179193Sjb#define FASTTRAP_PID_NAME "pid" 192179193Sjb 193179193Sjbfasttrap_hash_t fasttrap_tpoints; 194179193Sjbstatic fasttrap_hash_t fasttrap_provs; 195179193Sjbstatic fasttrap_hash_t fasttrap_procs; 196179193Sjb 197179193Sjbstatic uint64_t fasttrap_pid_count; /* pid ref count */ 198179193Sjbstatic kmutex_t fasttrap_count_mtx; /* lock on ref count */ 199179193Sjb 200179193Sjb#define FASTTRAP_ENABLE_FAIL 1 201179193Sjb#define FASTTRAP_ENABLE_PARTIAL 2 202179193Sjb 203179193Sjbstatic int fasttrap_tracepoint_enable(proc_t *, fasttrap_probe_t *, uint_t); 204179193Sjbstatic void fasttrap_tracepoint_disable(proc_t *, fasttrap_probe_t *, uint_t); 205179193Sjb 206179193Sjbstatic fasttrap_provider_t *fasttrap_provider_lookup(pid_t, const char *, 207179193Sjb const dtrace_pattr_t *); 208179193Sjbstatic void fasttrap_provider_retire(pid_t, const char *, int); 209179193Sjbstatic void fasttrap_provider_free(fasttrap_provider_t *); 210179193Sjb 211179193Sjbstatic fasttrap_proc_t *fasttrap_proc_lookup(pid_t); 212179193Sjbstatic void fasttrap_proc_release(fasttrap_proc_t *); 213179193Sjb 214264434Smarkj#if !defined(sun) 215264434Smarkjstatic void fasttrap_thread_dtor(void *, struct thread *); 216264434Smarkj#endif 217264434Smarkj 218179193Sjb#define FASTTRAP_PROVS_INDEX(pid, name) \ 219179193Sjb ((fasttrap_hash_str(name) + (pid)) & fasttrap_provs.fth_mask) 220179193Sjb 221179193Sjb#define FASTTRAP_PROCS_INDEX(pid) ((pid) & fasttrap_procs.fth_mask) 222179193Sjb 223211925Srpaulo#if !defined(sun) 224211925Srpaulostatic kmutex_t fasttrap_cpuc_pid_lock[MAXCPU]; 225264434Smarkjstatic eventhandler_tag fasttrap_thread_dtor_tag; 226211925Srpaulo#endif 227211925Srpaulo 228179193Sjbstatic int 229179193Sjbfasttrap_highbit(ulong_t i) 230179193Sjb{ 231179193Sjb int h = 1; 232179193Sjb 233179193Sjb if (i == 0) 234179193Sjb return (0); 235179193Sjb#ifdef _LP64 236179193Sjb if (i & 0xffffffff00000000ul) { 237179193Sjb h += 32; i >>= 32; 238179193Sjb } 239179193Sjb#endif 240179193Sjb if (i & 0xffff0000) { 241179193Sjb h += 16; i >>= 16; 242179193Sjb } 243179193Sjb if (i & 0xff00) { 244179193Sjb h += 8; i >>= 8; 245179193Sjb } 246179193Sjb if (i & 0xf0) { 247179193Sjb h += 4; i >>= 4; 248179193Sjb } 249179193Sjb if (i & 0xc) { 250179193Sjb h += 2; i >>= 2; 251179193Sjb } 252179193Sjb if (i & 0x2) { 253179193Sjb h += 1; 254179193Sjb } 255179193Sjb return (h); 256179193Sjb} 257179193Sjb 258179193Sjbstatic uint_t 259179193Sjbfasttrap_hash_str(const char *p) 260179193Sjb{ 261179193Sjb unsigned int g; 262179193Sjb uint_t hval = 0; 263179193Sjb 264179193Sjb while (*p) { 265179193Sjb hval = (hval << 4) + *p++; 266179193Sjb if ((g = (hval & 0xf0000000)) != 0) 267179193Sjb hval ^= g >> 24; 268179193Sjb hval &= ~g; 269179193Sjb } 270179193Sjb return (hval); 271179193Sjb} 272179193Sjb 273179193Sjbvoid 274179193Sjbfasttrap_sigtrap(proc_t *p, kthread_t *t, uintptr_t pc) 275179193Sjb{ 276211738Srpaulo#if defined(sun) 277179193Sjb sigqueue_t *sqp = kmem_zalloc(sizeof (sigqueue_t), KM_SLEEP); 278179193Sjb 279179193Sjb sqp->sq_info.si_signo = SIGTRAP; 280179193Sjb sqp->sq_info.si_code = TRAP_DTRACE; 281179193Sjb sqp->sq_info.si_addr = (caddr_t)pc; 282179193Sjb 283179193Sjb mutex_enter(&p->p_lock); 284179193Sjb sigaddqa(p, t, sqp); 285179193Sjb mutex_exit(&p->p_lock); 286179193Sjb 287179193Sjb if (t != NULL) 288179193Sjb aston(t); 289211738Srpaulo#else 290211738Srpaulo ksiginfo_t *ksi = kmem_zalloc(sizeof (ksiginfo_t), KM_SLEEP); 291211738Srpaulo 292211738Srpaulo ksiginfo_init(ksi); 293211738Srpaulo ksi->ksi_signo = SIGTRAP; 294211738Srpaulo ksi->ksi_code = TRAP_DTRACE; 295211738Srpaulo ksi->ksi_addr = (caddr_t)pc; 296211738Srpaulo PROC_LOCK(p); 297211745Srpaulo (void) tdksignal(t, SIGTRAP, ksi); 298211738Srpaulo PROC_UNLOCK(p); 299211738Srpaulo#endif 300179193Sjb} 301179193Sjb 302264434Smarkj#if !defined(sun) 303179193Sjb/* 304264434Smarkj * Obtain a chunk of scratch space in the address space of the target process. 305264434Smarkj */ 306264434Smarkjfasttrap_scrspace_t * 307264434Smarkjfasttrap_scraddr(struct thread *td, fasttrap_proc_t *fprc) 308264434Smarkj{ 309264434Smarkj fasttrap_scrblock_t *scrblk; 310264434Smarkj fasttrap_scrspace_t *scrspc; 311264434Smarkj struct proc *p; 312264434Smarkj vm_offset_t addr; 313264434Smarkj int error, i; 314264434Smarkj 315264434Smarkj scrspc = NULL; 316264434Smarkj if (td->t_dtrace_sscr != NULL) { 317264434Smarkj /* If the thread already has scratch space, we're done. */ 318264434Smarkj scrspc = (fasttrap_scrspace_t *)td->t_dtrace_sscr; 319264434Smarkj return (scrspc); 320264434Smarkj } 321264434Smarkj 322264434Smarkj p = td->td_proc; 323264434Smarkj 324264434Smarkj mutex_enter(&fprc->ftpc_mtx); 325264434Smarkj if (LIST_EMPTY(&fprc->ftpc_fscr)) { 326264434Smarkj /* 327264434Smarkj * No scratch space is available, so we'll map a new scratch 328264434Smarkj * space block into the traced process' address space. 329264434Smarkj */ 330264434Smarkj addr = 0; 331264434Smarkj error = vm_map_find(&p->p_vmspace->vm_map, NULL, 0, &addr, 332264434Smarkj FASTTRAP_SCRBLOCK_SIZE, 0, VMFS_ANY_SPACE, VM_PROT_ALL, 333264434Smarkj VM_PROT_ALL, 0); 334264434Smarkj if (error != KERN_SUCCESS) 335264434Smarkj goto done; 336264434Smarkj 337264434Smarkj scrblk = malloc(sizeof(*scrblk), M_SOLARIS, M_WAITOK); 338264434Smarkj scrblk->ftsb_addr = addr; 339264434Smarkj LIST_INSERT_HEAD(&fprc->ftpc_scrblks, scrblk, ftsb_next); 340264434Smarkj 341264434Smarkj /* 342264434Smarkj * Carve the block up into chunks and put them on the free list. 343264434Smarkj */ 344264434Smarkj for (i = 0; 345264434Smarkj i < FASTTRAP_SCRBLOCK_SIZE / FASTTRAP_SCRSPACE_SIZE; i++) { 346264434Smarkj scrspc = malloc(sizeof(*scrspc), M_SOLARIS, M_WAITOK); 347264434Smarkj scrspc->ftss_addr = addr + 348264434Smarkj i * FASTTRAP_SCRSPACE_SIZE; 349264434Smarkj LIST_INSERT_HEAD(&fprc->ftpc_fscr, scrspc, 350264434Smarkj ftss_next); 351264434Smarkj } 352264434Smarkj } 353264434Smarkj 354264434Smarkj /* 355264434Smarkj * Take the first scratch chunk off the free list, put it on the 356264434Smarkj * allocated list, and return its address. 357264434Smarkj */ 358264434Smarkj scrspc = LIST_FIRST(&fprc->ftpc_fscr); 359264434Smarkj LIST_REMOVE(scrspc, ftss_next); 360264434Smarkj LIST_INSERT_HEAD(&fprc->ftpc_ascr, scrspc, ftss_next); 361264434Smarkj 362264434Smarkj /* 363264434Smarkj * This scratch space is reserved for use by td until the thread exits. 364264434Smarkj */ 365264434Smarkj td->t_dtrace_sscr = scrspc; 366264434Smarkj 367264434Smarkjdone: 368264434Smarkj mutex_exit(&fprc->ftpc_mtx); 369264434Smarkj 370264434Smarkj return (scrspc); 371264434Smarkj} 372264434Smarkj 373264434Smarkj/* 374264434Smarkj * Return any allocated per-thread scratch space chunks back to the process' 375264434Smarkj * free list. 376264434Smarkj */ 377264434Smarkjstatic void 378264434Smarkjfasttrap_thread_dtor(void *arg __unused, struct thread *td) 379264434Smarkj{ 380264434Smarkj fasttrap_bucket_t *bucket; 381264434Smarkj fasttrap_proc_t *fprc; 382264434Smarkj fasttrap_scrspace_t *scrspc; 383264434Smarkj pid_t pid; 384264434Smarkj 385264434Smarkj if (td->t_dtrace_sscr == NULL) 386264434Smarkj return; 387264434Smarkj 388264434Smarkj pid = td->td_proc->p_pid; 389264434Smarkj bucket = &fasttrap_procs.fth_table[FASTTRAP_PROCS_INDEX(pid)]; 390264434Smarkj fprc = NULL; 391264434Smarkj 392264434Smarkj /* Look up the fasttrap process handle for this process. */ 393264434Smarkj mutex_enter(&bucket->ftb_mtx); 394264434Smarkj for (fprc = bucket->ftb_data; fprc != NULL; fprc = fprc->ftpc_next) { 395264434Smarkj if (fprc->ftpc_pid == pid) { 396264434Smarkj mutex_enter(&fprc->ftpc_mtx); 397264434Smarkj mutex_exit(&bucket->ftb_mtx); 398264434Smarkj break; 399264434Smarkj } 400264434Smarkj } 401264434Smarkj if (fprc == NULL) { 402264434Smarkj mutex_exit(&bucket->ftb_mtx); 403264434Smarkj return; 404264434Smarkj } 405264434Smarkj 406264434Smarkj scrspc = (fasttrap_scrspace_t *)td->t_dtrace_sscr; 407264434Smarkj LIST_REMOVE(scrspc, ftss_next); 408264434Smarkj LIST_INSERT_HEAD(&fprc->ftpc_fscr, scrspc, ftss_next); 409264434Smarkj 410264434Smarkj mutex_exit(&fprc->ftpc_mtx); 411264434Smarkj} 412264434Smarkj#endif 413264434Smarkj 414264434Smarkj/* 415179193Sjb * This function ensures that no threads are actively using the memory 416179193Sjb * associated with probes that were formerly live. 417179193Sjb */ 418179193Sjbstatic void 419179193Sjbfasttrap_mod_barrier(uint64_t gen) 420179193Sjb{ 421179193Sjb int i; 422179193Sjb 423179193Sjb if (gen < fasttrap_mod_gen) 424179193Sjb return; 425179193Sjb 426179193Sjb fasttrap_mod_gen++; 427179193Sjb 428211925Srpaulo CPU_FOREACH(i) { 429211925Srpaulo mutex_enter(&fasttrap_cpuc_pid_lock[i]); 430211925Srpaulo mutex_exit(&fasttrap_cpuc_pid_lock[i]); 431179193Sjb } 432179193Sjb} 433179193Sjb 434179193Sjb/* 435250953Smarkj * This function performs asynchronous cleanup of fasttrap providers. The 436250953Smarkj * Solaris implementation of this mechanism use a timeout that's activated in 437250953Smarkj * fasttrap_pid_cleanup(), but this doesn't work in FreeBSD: one may sleep while 438250953Smarkj * holding the DTrace mutexes, but it is unsafe to sleep in a callout handler. 439250953Smarkj * Thus we use a dedicated process to perform the cleanup when requested. 440179193Sjb */ 441179193Sjb/*ARGSUSED*/ 442179193Sjbstatic void 443179193Sjbfasttrap_pid_cleanup_cb(void *data) 444179193Sjb{ 445179193Sjb fasttrap_provider_t **fpp, *fp; 446179193Sjb fasttrap_bucket_t *bucket; 447179193Sjb dtrace_provider_id_t provid; 448248983Spfg int i, later = 0, rval; 449179193Sjb 450250953Smarkj mtx_lock(&fasttrap_cleanup_mtx); 451250953Smarkj while (!fasttrap_cleanup_drain || later > 0) { 452179193Sjb fasttrap_cleanup_work = 0; 453211738Srpaulo mtx_unlock(&fasttrap_cleanup_mtx); 454179193Sjb 455179193Sjb later = 0; 456179193Sjb 457179193Sjb /* 458179193Sjb * Iterate over all the providers trying to remove the marked 459179193Sjb * ones. If a provider is marked but not retired, we just 460179193Sjb * have to take a crack at removing it -- it's no big deal if 461179193Sjb * we can't. 462179193Sjb */ 463179193Sjb for (i = 0; i < fasttrap_provs.fth_nent; i++) { 464179193Sjb bucket = &fasttrap_provs.fth_table[i]; 465179193Sjb mutex_enter(&bucket->ftb_mtx); 466179193Sjb fpp = (fasttrap_provider_t **)&bucket->ftb_data; 467179193Sjb 468179193Sjb while ((fp = *fpp) != NULL) { 469179193Sjb if (!fp->ftp_marked) { 470179193Sjb fpp = &fp->ftp_next; 471179193Sjb continue; 472179193Sjb } 473179193Sjb 474179193Sjb mutex_enter(&fp->ftp_mtx); 475179193Sjb 476179193Sjb /* 477179193Sjb * If this provider has consumers actively 478179193Sjb * creating probes (ftp_ccount) or is a USDT 479179193Sjb * provider (ftp_mcount), we can't unregister 480179193Sjb * or even condense. 481179193Sjb */ 482179193Sjb if (fp->ftp_ccount != 0 || 483179193Sjb fp->ftp_mcount != 0) { 484179193Sjb mutex_exit(&fp->ftp_mtx); 485179193Sjb fp->ftp_marked = 0; 486179193Sjb continue; 487179193Sjb } 488179193Sjb 489179193Sjb if (!fp->ftp_retired || fp->ftp_rcount != 0) 490179193Sjb fp->ftp_marked = 0; 491179193Sjb 492179193Sjb mutex_exit(&fp->ftp_mtx); 493179193Sjb 494179193Sjb /* 495179193Sjb * If we successfully unregister this 496179193Sjb * provider we can remove it from the hash 497179193Sjb * chain and free the memory. If our attempt 498179193Sjb * to unregister fails and this is a retired 499179193Sjb * provider, increment our flag to try again 500179193Sjb * pretty soon. If we've consumed more than 501179193Sjb * half of our total permitted number of 502179193Sjb * probes call dtrace_condense() to try to 503179193Sjb * clean out the unenabled probes. 504179193Sjb */ 505179193Sjb provid = fp->ftp_provid; 506248983Spfg if ((rval = dtrace_unregister(provid)) != 0) { 507179193Sjb if (fasttrap_total > fasttrap_max / 2) 508179193Sjb (void) dtrace_condense(provid); 509248983Spfg 510248983Spfg if (rval == EAGAIN) 511248983Spfg fp->ftp_marked = 1; 512248983Spfg 513179193Sjb later += fp->ftp_marked; 514179193Sjb fpp = &fp->ftp_next; 515179193Sjb } else { 516179193Sjb *fpp = fp->ftp_next; 517179193Sjb fasttrap_provider_free(fp); 518179193Sjb } 519179193Sjb } 520179193Sjb mutex_exit(&bucket->ftb_mtx); 521179193Sjb } 522250953Smarkj mtx_lock(&fasttrap_cleanup_mtx); 523179193Sjb 524250953Smarkj /* 525250953Smarkj * If we were unable to retire a provider, try again after a 526250953Smarkj * second. This situation can occur in certain circumstances 527250953Smarkj * where providers cannot be unregistered even though they have 528250953Smarkj * no probes enabled because of an execution of dtrace -l or 529250953Smarkj * something similar. 530250953Smarkj */ 531250953Smarkj if (later > 0 || fasttrap_cleanup_work || 532250953Smarkj fasttrap_cleanup_drain) { 533250953Smarkj mtx_unlock(&fasttrap_cleanup_mtx); 534250953Smarkj pause("ftclean", hz); 535250953Smarkj mtx_lock(&fasttrap_cleanup_mtx); 536250953Smarkj } else 537250953Smarkj mtx_sleep(&fasttrap_cleanup_cv, &fasttrap_cleanup_mtx, 538250953Smarkj 0, "ftcl", 0); 539179193Sjb } 540179193Sjb 541179193Sjb /* 542250953Smarkj * Wake up the thread in fasttrap_unload() now that we're done. 543179193Sjb */ 544250953Smarkj wakeup(&fasttrap_cleanup_drain); 545250953Smarkj mtx_unlock(&fasttrap_cleanup_mtx); 546179193Sjb 547250953Smarkj kthread_exit(); 548179193Sjb} 549179193Sjb 550179193Sjb/* 551179193Sjb * Activates the asynchronous cleanup mechanism. 552179193Sjb */ 553179193Sjbstatic void 554179193Sjbfasttrap_pid_cleanup(void) 555179193Sjb{ 556211738Srpaulo 557211738Srpaulo mtx_lock(&fasttrap_cleanup_mtx); 558250953Smarkj if (!fasttrap_cleanup_work) { 559250953Smarkj fasttrap_cleanup_work = 1; 560250953Smarkj wakeup(&fasttrap_cleanup_cv); 561250953Smarkj } 562211738Srpaulo mtx_unlock(&fasttrap_cleanup_mtx); 563179193Sjb} 564179193Sjb 565179193Sjb/* 566179193Sjb * This is called from cfork() via dtrace_fasttrap_fork(). The child 567179198Sjb * process's address space is (roughly) a copy of the parent process's so 568179193Sjb * we have to remove all the instrumentation we had previously enabled in the 569179193Sjb * parent. 570179193Sjb */ 571179193Sjbstatic void 572179193Sjbfasttrap_fork(proc_t *p, proc_t *cp) 573179193Sjb{ 574264434Smarkj#if !defined(sun) 575264434Smarkj fasttrap_scrblock_t *scrblk; 576264434Smarkj fasttrap_proc_t *fprc = NULL; 577264434Smarkj#endif 578179193Sjb pid_t ppid = p->p_pid; 579179193Sjb int i; 580179193Sjb 581211738Srpaulo#if defined(sun) 582179193Sjb ASSERT(curproc == p); 583179193Sjb ASSERT(p->p_proc_flag & P_PR_LOCK); 584211738Srpaulo#else 585211738Srpaulo PROC_LOCK_ASSERT(p, MA_OWNED); 586211738Srpaulo#endif 587211738Srpaulo#if defined(sun) 588179193Sjb ASSERT(p->p_dtrace_count > 0); 589211738Srpaulo#else 590212357Srpaulo if (p->p_dtrace_helpers) { 591212357Srpaulo /* 592212357Srpaulo * dtrace_helpers_duplicate() allocates memory. 593212357Srpaulo */ 594212494Srpaulo _PHOLD(cp); 595212357Srpaulo PROC_UNLOCK(p); 596212357Srpaulo PROC_UNLOCK(cp); 597212357Srpaulo dtrace_helpers_duplicate(p, cp); 598212357Srpaulo PROC_LOCK(cp); 599212357Srpaulo PROC_LOCK(p); 600212494Srpaulo _PRELE(cp); 601212357Srpaulo } 602211738Srpaulo /* 603211738Srpaulo * This check is purposely here instead of in kern_fork.c because, 604211738Srpaulo * for legal resons, we cannot include the dtrace_cddl.h header 605211738Srpaulo * inside kern_fork.c and insert if-clause there. 606211738Srpaulo */ 607211738Srpaulo if (p->p_dtrace_count == 0) 608211738Srpaulo return; 609211738Srpaulo#endif 610179193Sjb ASSERT(cp->p_dtrace_count == 0); 611179193Sjb 612179193Sjb /* 613179193Sjb * This would be simpler and faster if we maintained per-process 614179193Sjb * hash tables of enabled tracepoints. It could, however, potentially 615179193Sjb * slow down execution of a tracepoint since we'd need to go 616179193Sjb * through two levels of indirection. In the future, we should 617179193Sjb * consider either maintaining per-process ancillary lists of 618179193Sjb * enabled tracepoints or hanging a pointer to a per-process hash 619179193Sjb * table of enabled tracepoints off the proc structure. 620179193Sjb */ 621179193Sjb 622179193Sjb /* 623179193Sjb * We don't have to worry about the child process disappearing 624179193Sjb * because we're in fork(). 625179193Sjb */ 626211738Srpaulo#if defined(sun) 627211738Srpaulo mtx_lock_spin(&cp->p_slock); 628179193Sjb sprlock_proc(cp); 629211738Srpaulo mtx_unlock_spin(&cp->p_slock); 630212494Srpaulo#else 631254198Srpaulo /* 632254198Srpaulo * fasttrap_tracepoint_remove() expects the child process to be 633254198Srpaulo * unlocked and the VM then expects curproc to be unlocked. 634254198Srpaulo */ 635212494Srpaulo _PHOLD(cp); 636254198Srpaulo PROC_UNLOCK(cp); 637254198Srpaulo PROC_UNLOCK(p); 638211738Srpaulo#endif 639179193Sjb 640179193Sjb /* 641179193Sjb * Iterate over every tracepoint looking for ones that belong to the 642179193Sjb * parent process, and remove each from the child process. 643179193Sjb */ 644179193Sjb for (i = 0; i < fasttrap_tpoints.fth_nent; i++) { 645179193Sjb fasttrap_tracepoint_t *tp; 646179193Sjb fasttrap_bucket_t *bucket = &fasttrap_tpoints.fth_table[i]; 647179193Sjb 648179193Sjb mutex_enter(&bucket->ftb_mtx); 649179193Sjb for (tp = bucket->ftb_data; tp != NULL; tp = tp->ftt_next) { 650179193Sjb if (tp->ftt_pid == ppid && 651179193Sjb tp->ftt_proc->ftpc_acount != 0) { 652179193Sjb int ret = fasttrap_tracepoint_remove(cp, tp); 653179193Sjb ASSERT(ret == 0); 654179198Sjb 655179198Sjb /* 656179198Sjb * The count of active providers can only be 657179198Sjb * decremented (i.e. to zero) during exec, 658179198Sjb * exit, and removal of a meta provider so it 659179198Sjb * should be impossible to drop the count 660179198Sjb * mid-fork. 661179198Sjb */ 662179198Sjb ASSERT(tp->ftt_proc->ftpc_acount != 0); 663264434Smarkj#if !defined(sun) 664264434Smarkj fprc = tp->ftt_proc; 665264434Smarkj#endif 666179193Sjb } 667179193Sjb } 668179193Sjb mutex_exit(&bucket->ftb_mtx); 669264434Smarkj 670264434Smarkj#if !defined(sun) 671264434Smarkj /* 672264434Smarkj * Unmap any scratch space inherited from the parent's address 673264434Smarkj * space. 674264434Smarkj */ 675264434Smarkj if (fprc != NULL) { 676264434Smarkj mutex_enter(&fprc->ftpc_mtx); 677264434Smarkj LIST_FOREACH(scrblk, &fprc->ftpc_scrblks, ftsb_next) { 678264434Smarkj vm_map_remove(&cp->p_vmspace->vm_map, 679264434Smarkj scrblk->ftsb_addr, 680264434Smarkj scrblk->ftsb_addr + FASTTRAP_SCRBLOCK_SIZE); 681264434Smarkj } 682264434Smarkj mutex_exit(&fprc->ftpc_mtx); 683264434Smarkj } 684264434Smarkj#endif 685179193Sjb } 686179193Sjb 687211738Srpaulo#if defined(sun) 688179193Sjb mutex_enter(&cp->p_lock); 689179193Sjb sprunlock(cp); 690212494Srpaulo#else 691254198Srpaulo PROC_LOCK(p); 692254198Srpaulo PROC_LOCK(cp); 693212494Srpaulo _PRELE(cp); 694211738Srpaulo#endif 695179193Sjb} 696179193Sjb 697179193Sjb/* 698179193Sjb * This is called from proc_exit() or from exec_common() if p_dtrace_probes 699179193Sjb * is set on the proc structure to indicate that there is a pid provider 700179193Sjb * associated with this process. 701179193Sjb */ 702179193Sjbstatic void 703179193Sjbfasttrap_exec_exit(proc_t *p) 704179193Sjb{ 705264434Smarkj#if !defined(sun) 706264434Smarkj struct thread *td; 707264434Smarkj#endif 708264434Smarkj 709211738Srpaulo#if defined(sun) 710179193Sjb ASSERT(p == curproc); 711264434Smarkj#else 712211738Srpaulo PROC_LOCK_ASSERT(p, MA_OWNED); 713212494Srpaulo _PHOLD(p); 714264434Smarkj /* 715264434Smarkj * Since struct threads may be recycled, we cannot rely on t_dtrace_sscr 716264434Smarkj * fields to be zeroed by kdtrace_thread_ctor. Thus we must zero it 717264434Smarkj * ourselves when a process exits. 718264434Smarkj */ 719264434Smarkj FOREACH_THREAD_IN_PROC(p, td) 720264434Smarkj td->t_dtrace_sscr = NULL; 721211738Srpaulo PROC_UNLOCK(p); 722264434Smarkj#endif 723179193Sjb 724179193Sjb /* 725179193Sjb * We clean up the pid provider for this process here; user-land 726179193Sjb * static probes are handled by the meta-provider remove entry point. 727179193Sjb */ 728179193Sjb fasttrap_provider_retire(p->p_pid, FASTTRAP_PID_NAME, 0); 729212357Srpaulo#if !defined(sun) 730212357Srpaulo if (p->p_dtrace_helpers) 731212357Srpaulo dtrace_helpers_destroy(p); 732211738Srpaulo PROC_LOCK(p); 733212494Srpaulo _PRELE(p); 734264434Smarkj#endif 735179193Sjb} 736179193Sjb 737179193Sjb 738179193Sjb/*ARGSUSED*/ 739179193Sjbstatic void 740211738Srpaulofasttrap_pid_provide(void *arg, dtrace_probedesc_t *desc) 741179193Sjb{ 742179193Sjb /* 743179193Sjb * There are no "default" pid probes. 744179193Sjb */ 745179193Sjb} 746179193Sjb 747179193Sjbstatic int 748179193Sjbfasttrap_tracepoint_enable(proc_t *p, fasttrap_probe_t *probe, uint_t index) 749179193Sjb{ 750179193Sjb fasttrap_tracepoint_t *tp, *new_tp = NULL; 751179193Sjb fasttrap_bucket_t *bucket; 752179193Sjb fasttrap_id_t *id; 753179193Sjb pid_t pid; 754179193Sjb uintptr_t pc; 755179193Sjb 756179193Sjb ASSERT(index < probe->ftp_ntps); 757179193Sjb 758179193Sjb pid = probe->ftp_pid; 759179193Sjb pc = probe->ftp_tps[index].fit_tp->ftt_pc; 760179193Sjb id = &probe->ftp_tps[index].fit_id; 761179193Sjb 762179193Sjb ASSERT(probe->ftp_tps[index].fit_tp->ftt_pid == pid); 763179193Sjb 764211738Srpaulo#if defined(sun) 765179193Sjb ASSERT(!(p->p_flag & SVFORK)); 766211738Srpaulo#endif 767179193Sjb 768179193Sjb /* 769179193Sjb * Before we make any modifications, make sure we've imposed a barrier 770179193Sjb * on the generation in which this probe was last modified. 771179193Sjb */ 772179193Sjb fasttrap_mod_barrier(probe->ftp_gen); 773179193Sjb 774179193Sjb bucket = &fasttrap_tpoints.fth_table[FASTTRAP_TPOINTS_INDEX(pid, pc)]; 775179193Sjb 776179193Sjb /* 777179193Sjb * If the tracepoint has already been enabled, just add our id to the 778179193Sjb * list of interested probes. This may be our second time through 779179193Sjb * this path in which case we'll have constructed the tracepoint we'd 780179193Sjb * like to install. If we can't find a match, and have an allocated 781179193Sjb * tracepoint ready to go, enable that one now. 782179193Sjb * 783179193Sjb * A tracepoint whose process is defunct is also considered defunct. 784179193Sjb */ 785179193Sjbagain: 786179193Sjb mutex_enter(&bucket->ftb_mtx); 787179193Sjb for (tp = bucket->ftb_data; tp != NULL; tp = tp->ftt_next) { 788179198Sjb /* 789179198Sjb * Note that it's safe to access the active count on the 790179198Sjb * associated proc structure because we know that at least one 791179198Sjb * provider (this one) will still be around throughout this 792179198Sjb * operation. 793179198Sjb */ 794179193Sjb if (tp->ftt_pid != pid || tp->ftt_pc != pc || 795179193Sjb tp->ftt_proc->ftpc_acount == 0) 796179193Sjb continue; 797179193Sjb 798179193Sjb /* 799179193Sjb * Now that we've found a matching tracepoint, it would be 800179193Sjb * a decent idea to confirm that the tracepoint is still 801179193Sjb * enabled and the trap instruction hasn't been overwritten. 802179193Sjb * Since this is a little hairy, we'll punt for now. 803179193Sjb */ 804179193Sjb 805179193Sjb /* 806179193Sjb * This can't be the first interested probe. We don't have 807179193Sjb * to worry about another thread being in the midst of 808179193Sjb * deleting this tracepoint (which would be the only valid 809179193Sjb * reason for a tracepoint to have no interested probes) 810179193Sjb * since we're holding P_PR_LOCK for this process. 811179193Sjb */ 812179193Sjb ASSERT(tp->ftt_ids != NULL || tp->ftt_retids != NULL); 813179193Sjb 814179193Sjb switch (id->fti_ptype) { 815179193Sjb case DTFTP_ENTRY: 816179193Sjb case DTFTP_OFFSETS: 817179193Sjb case DTFTP_IS_ENABLED: 818179193Sjb id->fti_next = tp->ftt_ids; 819179193Sjb membar_producer(); 820179193Sjb tp->ftt_ids = id; 821179193Sjb membar_producer(); 822179193Sjb break; 823179193Sjb 824179193Sjb case DTFTP_RETURN: 825179193Sjb case DTFTP_POST_OFFSETS: 826179193Sjb id->fti_next = tp->ftt_retids; 827179193Sjb membar_producer(); 828179193Sjb tp->ftt_retids = id; 829179193Sjb membar_producer(); 830179193Sjb break; 831179193Sjb 832179193Sjb default: 833179193Sjb ASSERT(0); 834179193Sjb } 835179193Sjb 836179193Sjb mutex_exit(&bucket->ftb_mtx); 837179193Sjb 838179193Sjb if (new_tp != NULL) { 839179193Sjb new_tp->ftt_ids = NULL; 840179193Sjb new_tp->ftt_retids = NULL; 841179193Sjb } 842179193Sjb 843179193Sjb return (0); 844179193Sjb } 845179193Sjb 846179193Sjb /* 847179193Sjb * If we have a good tracepoint ready to go, install it now while 848179193Sjb * we have the lock held and no one can screw with us. 849179193Sjb */ 850179193Sjb if (new_tp != NULL) { 851179193Sjb int rc = 0; 852179193Sjb 853179193Sjb new_tp->ftt_next = bucket->ftb_data; 854179193Sjb membar_producer(); 855179193Sjb bucket->ftb_data = new_tp; 856179193Sjb membar_producer(); 857179193Sjb mutex_exit(&bucket->ftb_mtx); 858179193Sjb 859179193Sjb /* 860179193Sjb * Activate the tracepoint in the ISA-specific manner. 861179193Sjb * If this fails, we need to report the failure, but 862179193Sjb * indicate that this tracepoint must still be disabled 863179193Sjb * by calling fasttrap_tracepoint_disable(). 864179193Sjb */ 865179193Sjb if (fasttrap_tracepoint_install(p, new_tp) != 0) 866179193Sjb rc = FASTTRAP_ENABLE_PARTIAL; 867179193Sjb 868179193Sjb /* 869179193Sjb * Increment the count of the number of tracepoints active in 870179193Sjb * the victim process. 871179193Sjb */ 872211738Srpaulo#if defined(sun) 873179193Sjb ASSERT(p->p_proc_flag & P_PR_LOCK); 874211738Srpaulo#endif 875179193Sjb p->p_dtrace_count++; 876179193Sjb 877179193Sjb return (rc); 878179193Sjb } 879179193Sjb 880179193Sjb mutex_exit(&bucket->ftb_mtx); 881179193Sjb 882179193Sjb /* 883179193Sjb * Initialize the tracepoint that's been preallocated with the probe. 884179193Sjb */ 885179193Sjb new_tp = probe->ftp_tps[index].fit_tp; 886179193Sjb 887179193Sjb ASSERT(new_tp->ftt_pid == pid); 888179193Sjb ASSERT(new_tp->ftt_pc == pc); 889179193Sjb ASSERT(new_tp->ftt_proc == probe->ftp_prov->ftp_proc); 890179193Sjb ASSERT(new_tp->ftt_ids == NULL); 891179193Sjb ASSERT(new_tp->ftt_retids == NULL); 892179193Sjb 893179193Sjb switch (id->fti_ptype) { 894179193Sjb case DTFTP_ENTRY: 895179193Sjb case DTFTP_OFFSETS: 896179193Sjb case DTFTP_IS_ENABLED: 897179193Sjb id->fti_next = NULL; 898179193Sjb new_tp->ftt_ids = id; 899179193Sjb break; 900179193Sjb 901179193Sjb case DTFTP_RETURN: 902179193Sjb case DTFTP_POST_OFFSETS: 903179193Sjb id->fti_next = NULL; 904179193Sjb new_tp->ftt_retids = id; 905179193Sjb break; 906179193Sjb 907179193Sjb default: 908179193Sjb ASSERT(0); 909179193Sjb } 910179193Sjb 911179193Sjb /* 912179193Sjb * If the ISA-dependent initialization goes to plan, go back to the 913179193Sjb * beginning and try to install this freshly made tracepoint. 914179193Sjb */ 915179193Sjb if (fasttrap_tracepoint_init(p, new_tp, pc, id->fti_ptype) == 0) 916179193Sjb goto again; 917179193Sjb 918179193Sjb new_tp->ftt_ids = NULL; 919179193Sjb new_tp->ftt_retids = NULL; 920179193Sjb 921179193Sjb return (FASTTRAP_ENABLE_FAIL); 922179193Sjb} 923179193Sjb 924179193Sjbstatic void 925179193Sjbfasttrap_tracepoint_disable(proc_t *p, fasttrap_probe_t *probe, uint_t index) 926179193Sjb{ 927179193Sjb fasttrap_bucket_t *bucket; 928179193Sjb fasttrap_provider_t *provider = probe->ftp_prov; 929179193Sjb fasttrap_tracepoint_t **pp, *tp; 930211738Srpaulo fasttrap_id_t *id, **idp = NULL; 931179193Sjb pid_t pid; 932179193Sjb uintptr_t pc; 933179193Sjb 934179193Sjb ASSERT(index < probe->ftp_ntps); 935179193Sjb 936179193Sjb pid = probe->ftp_pid; 937179193Sjb pc = probe->ftp_tps[index].fit_tp->ftt_pc; 938179193Sjb id = &probe->ftp_tps[index].fit_id; 939179193Sjb 940179193Sjb ASSERT(probe->ftp_tps[index].fit_tp->ftt_pid == pid); 941179193Sjb 942179193Sjb /* 943179193Sjb * Find the tracepoint and make sure that our id is one of the 944179193Sjb * ones registered with it. 945179193Sjb */ 946179193Sjb bucket = &fasttrap_tpoints.fth_table[FASTTRAP_TPOINTS_INDEX(pid, pc)]; 947179193Sjb mutex_enter(&bucket->ftb_mtx); 948179193Sjb for (tp = bucket->ftb_data; tp != NULL; tp = tp->ftt_next) { 949179193Sjb if (tp->ftt_pid == pid && tp->ftt_pc == pc && 950179193Sjb tp->ftt_proc == provider->ftp_proc) 951179193Sjb break; 952179193Sjb } 953179193Sjb 954179193Sjb /* 955179193Sjb * If we somehow lost this tracepoint, we're in a world of hurt. 956179193Sjb */ 957179193Sjb ASSERT(tp != NULL); 958179193Sjb 959179193Sjb switch (id->fti_ptype) { 960179193Sjb case DTFTP_ENTRY: 961179193Sjb case DTFTP_OFFSETS: 962179193Sjb case DTFTP_IS_ENABLED: 963179193Sjb ASSERT(tp->ftt_ids != NULL); 964179193Sjb idp = &tp->ftt_ids; 965179193Sjb break; 966179193Sjb 967179193Sjb case DTFTP_RETURN: 968179193Sjb case DTFTP_POST_OFFSETS: 969179193Sjb ASSERT(tp->ftt_retids != NULL); 970179193Sjb idp = &tp->ftt_retids; 971179193Sjb break; 972179193Sjb 973179193Sjb default: 974179193Sjb ASSERT(0); 975179193Sjb } 976179193Sjb 977179193Sjb while ((*idp)->fti_probe != probe) { 978179193Sjb idp = &(*idp)->fti_next; 979179193Sjb ASSERT(*idp != NULL); 980179193Sjb } 981179193Sjb 982179193Sjb id = *idp; 983179193Sjb *idp = id->fti_next; 984179193Sjb membar_producer(); 985179193Sjb 986179193Sjb ASSERT(id->fti_probe == probe); 987179193Sjb 988179193Sjb /* 989179193Sjb * If there are other registered enablings of this tracepoint, we're 990179193Sjb * all done, but if this was the last probe assocated with this 991179193Sjb * this tracepoint, we need to remove and free it. 992179193Sjb */ 993179193Sjb if (tp->ftt_ids != NULL || tp->ftt_retids != NULL) { 994179193Sjb 995179193Sjb /* 996179193Sjb * If the current probe's tracepoint is in use, swap it 997179193Sjb * for an unused tracepoint. 998179193Sjb */ 999179193Sjb if (tp == probe->ftp_tps[index].fit_tp) { 1000179193Sjb fasttrap_probe_t *tmp_probe; 1001179193Sjb fasttrap_tracepoint_t **tmp_tp; 1002179193Sjb uint_t tmp_index; 1003179193Sjb 1004179193Sjb if (tp->ftt_ids != NULL) { 1005179193Sjb tmp_probe = tp->ftt_ids->fti_probe; 1006179193Sjb /* LINTED - alignment */ 1007179193Sjb tmp_index = FASTTRAP_ID_INDEX(tp->ftt_ids); 1008179193Sjb tmp_tp = &tmp_probe->ftp_tps[tmp_index].fit_tp; 1009179193Sjb } else { 1010179193Sjb tmp_probe = tp->ftt_retids->fti_probe; 1011179193Sjb /* LINTED - alignment */ 1012179193Sjb tmp_index = FASTTRAP_ID_INDEX(tp->ftt_retids); 1013179193Sjb tmp_tp = &tmp_probe->ftp_tps[tmp_index].fit_tp; 1014179193Sjb } 1015179193Sjb 1016179193Sjb ASSERT(*tmp_tp != NULL); 1017179193Sjb ASSERT(*tmp_tp != probe->ftp_tps[index].fit_tp); 1018179193Sjb ASSERT((*tmp_tp)->ftt_ids == NULL); 1019179193Sjb ASSERT((*tmp_tp)->ftt_retids == NULL); 1020179193Sjb 1021179193Sjb probe->ftp_tps[index].fit_tp = *tmp_tp; 1022179193Sjb *tmp_tp = tp; 1023179193Sjb } 1024179193Sjb 1025179193Sjb mutex_exit(&bucket->ftb_mtx); 1026179193Sjb 1027179193Sjb /* 1028179193Sjb * Tag the modified probe with the generation in which it was 1029179193Sjb * changed. 1030179193Sjb */ 1031179193Sjb probe->ftp_gen = fasttrap_mod_gen; 1032179193Sjb return; 1033179193Sjb } 1034179193Sjb 1035179193Sjb mutex_exit(&bucket->ftb_mtx); 1036179193Sjb 1037179193Sjb /* 1038179193Sjb * We can't safely remove the tracepoint from the set of active 1039179193Sjb * tracepoints until we've actually removed the fasttrap instruction 1040179193Sjb * from the process's text. We can, however, operate on this 1041179193Sjb * tracepoint secure in the knowledge that no other thread is going to 1042179193Sjb * be looking at it since we hold P_PR_LOCK on the process if it's 1043179193Sjb * live or we hold the provider lock on the process if it's dead and 1044179193Sjb * gone. 1045179193Sjb */ 1046179193Sjb 1047179193Sjb /* 1048179193Sjb * We only need to remove the actual instruction if we're looking 1049179193Sjb * at an existing process 1050179193Sjb */ 1051179193Sjb if (p != NULL) { 1052179193Sjb /* 1053179193Sjb * If we fail to restore the instruction we need to kill 1054179193Sjb * this process since it's in a completely unrecoverable 1055179193Sjb * state. 1056179193Sjb */ 1057179193Sjb if (fasttrap_tracepoint_remove(p, tp) != 0) 1058179193Sjb fasttrap_sigtrap(p, NULL, pc); 1059179193Sjb 1060179193Sjb /* 1061179193Sjb * Decrement the count of the number of tracepoints active 1062179193Sjb * in the victim process. 1063179193Sjb */ 1064211738Srpaulo#if defined(sun) 1065179193Sjb ASSERT(p->p_proc_flag & P_PR_LOCK); 1066211738Srpaulo#endif 1067179193Sjb p->p_dtrace_count--; 1068179193Sjb } 1069179193Sjb 1070179193Sjb /* 1071179193Sjb * Remove the probe from the hash table of active tracepoints. 1072179193Sjb */ 1073179193Sjb mutex_enter(&bucket->ftb_mtx); 1074179193Sjb pp = (fasttrap_tracepoint_t **)&bucket->ftb_data; 1075179193Sjb ASSERT(*pp != NULL); 1076179193Sjb while (*pp != tp) { 1077179193Sjb pp = &(*pp)->ftt_next; 1078179193Sjb ASSERT(*pp != NULL); 1079179193Sjb } 1080179193Sjb 1081179193Sjb *pp = tp->ftt_next; 1082179193Sjb membar_producer(); 1083179193Sjb 1084179193Sjb mutex_exit(&bucket->ftb_mtx); 1085179193Sjb 1086179193Sjb /* 1087179193Sjb * Tag the modified probe with the generation in which it was changed. 1088179193Sjb */ 1089179193Sjb probe->ftp_gen = fasttrap_mod_gen; 1090179193Sjb} 1091179193Sjb 1092179193Sjbstatic void 1093179193Sjbfasttrap_enable_callbacks(void) 1094179193Sjb{ 1095179193Sjb /* 1096179193Sjb * We don't have to play the rw lock game here because we're 1097179193Sjb * providing something rather than taking something away -- 1098179193Sjb * we can be sure that no threads have tried to follow this 1099179193Sjb * function pointer yet. 1100179193Sjb */ 1101179193Sjb mutex_enter(&fasttrap_count_mtx); 1102179193Sjb if (fasttrap_pid_count == 0) { 1103179193Sjb ASSERT(dtrace_pid_probe_ptr == NULL); 1104179193Sjb ASSERT(dtrace_return_probe_ptr == NULL); 1105179193Sjb dtrace_pid_probe_ptr = &fasttrap_pid_probe; 1106179193Sjb dtrace_return_probe_ptr = &fasttrap_return_probe; 1107179193Sjb } 1108179193Sjb ASSERT(dtrace_pid_probe_ptr == &fasttrap_pid_probe); 1109179193Sjb ASSERT(dtrace_return_probe_ptr == &fasttrap_return_probe); 1110179193Sjb fasttrap_pid_count++; 1111179193Sjb mutex_exit(&fasttrap_count_mtx); 1112179193Sjb} 1113179193Sjb 1114179193Sjbstatic void 1115179193Sjbfasttrap_disable_callbacks(void) 1116179193Sjb{ 1117211738Srpaulo#if defined(sun) 1118179193Sjb ASSERT(MUTEX_HELD(&cpu_lock)); 1119211738Srpaulo#endif 1120179193Sjb 1121211738Srpaulo 1122179193Sjb mutex_enter(&fasttrap_count_mtx); 1123179193Sjb ASSERT(fasttrap_pid_count > 0); 1124179193Sjb fasttrap_pid_count--; 1125179193Sjb if (fasttrap_pid_count == 0) { 1126211738Srpaulo#if defined(sun) 1127179193Sjb cpu_t *cur, *cpu = CPU; 1128179193Sjb 1129179193Sjb for (cur = cpu->cpu_next_onln; cur != cpu; 1130179193Sjb cur = cur->cpu_next_onln) { 1131179193Sjb rw_enter(&cur->cpu_ft_lock, RW_WRITER); 1132179193Sjb } 1133211738Srpaulo#endif 1134179193Sjb dtrace_pid_probe_ptr = NULL; 1135179193Sjb dtrace_return_probe_ptr = NULL; 1136211738Srpaulo#if defined(sun) 1137179193Sjb for (cur = cpu->cpu_next_onln; cur != cpu; 1138179193Sjb cur = cur->cpu_next_onln) { 1139179193Sjb rw_exit(&cur->cpu_ft_lock); 1140179193Sjb } 1141211738Srpaulo#endif 1142179193Sjb } 1143179193Sjb mutex_exit(&fasttrap_count_mtx); 1144179193Sjb} 1145179193Sjb 1146179193Sjb/*ARGSUSED*/ 1147179193Sjbstatic void 1148179193Sjbfasttrap_pid_enable(void *arg, dtrace_id_t id, void *parg) 1149179193Sjb{ 1150179193Sjb fasttrap_probe_t *probe = parg; 1151211738Srpaulo proc_t *p = NULL; 1152179193Sjb int i, rc; 1153179193Sjb 1154179193Sjb ASSERT(probe != NULL); 1155179193Sjb ASSERT(!probe->ftp_enabled); 1156179193Sjb ASSERT(id == probe->ftp_id); 1157211738Srpaulo#if defined(sun) 1158179193Sjb ASSERT(MUTEX_HELD(&cpu_lock)); 1159211738Srpaulo#endif 1160179193Sjb 1161179193Sjb /* 1162179193Sjb * Increment the count of enabled probes on this probe's provider; 1163179193Sjb * the provider can't go away while the probe still exists. We 1164179193Sjb * must increment this even if we aren't able to properly enable 1165179193Sjb * this probe. 1166179193Sjb */ 1167179193Sjb mutex_enter(&probe->ftp_prov->ftp_mtx); 1168179193Sjb probe->ftp_prov->ftp_rcount++; 1169179193Sjb mutex_exit(&probe->ftp_prov->ftp_mtx); 1170179193Sjb 1171179193Sjb /* 1172179193Sjb * If this probe's provider is retired (meaning it was valid in a 1173179193Sjb * previously exec'ed incarnation of this address space), bail out. The 1174179193Sjb * provider can't go away while we're in this code path. 1175179193Sjb */ 1176179193Sjb if (probe->ftp_prov->ftp_retired) 1177179193Sjb return; 1178179193Sjb 1179179193Sjb /* 1180179193Sjb * If we can't find the process, it may be that we're in the context of 1181179193Sjb * a fork in which the traced process is being born and we're copying 1182179193Sjb * USDT probes. Otherwise, the process is gone so bail. 1183179193Sjb */ 1184211738Srpaulo#if defined(sun) 1185179193Sjb if ((p = sprlock(probe->ftp_pid)) == NULL) { 1186179193Sjb if ((curproc->p_flag & SFORKING) == 0) 1187179193Sjb return; 1188179193Sjb 1189179193Sjb mutex_enter(&pidlock); 1190179193Sjb p = prfind(probe->ftp_pid); 1191179193Sjb 1192179193Sjb /* 1193179193Sjb * Confirm that curproc is indeed forking the process in which 1194179193Sjb * we're trying to enable probes. 1195179193Sjb */ 1196179193Sjb ASSERT(p != NULL); 1197179193Sjb ASSERT(p->p_parent == curproc); 1198179193Sjb ASSERT(p->p_stat == SIDL); 1199179193Sjb 1200179193Sjb mutex_enter(&p->p_lock); 1201179193Sjb mutex_exit(&pidlock); 1202179193Sjb 1203179193Sjb sprlock_proc(p); 1204179193Sjb } 1205179193Sjb 1206179193Sjb ASSERT(!(p->p_flag & SVFORK)); 1207179193Sjb mutex_exit(&p->p_lock); 1208211738Srpaulo#else 1209211738Srpaulo if ((p = pfind(probe->ftp_pid)) == NULL) 1210211738Srpaulo return; 1211211738Srpaulo#endif 1212179193Sjb 1213179193Sjb /* 1214179193Sjb * We have to enable the trap entry point before any user threads have 1215179193Sjb * the chance to execute the trap instruction we're about to place 1216179193Sjb * in their process's text. 1217179193Sjb */ 1218212494Srpaulo#ifdef __FreeBSD__ 1219212494Srpaulo /* 1220212494Srpaulo * pfind() returns a locked process. 1221212494Srpaulo */ 1222212494Srpaulo _PHOLD(p); 1223211738Srpaulo PROC_UNLOCK(p); 1224212494Srpaulo#endif 1225179193Sjb fasttrap_enable_callbacks(); 1226179193Sjb 1227179193Sjb /* 1228179193Sjb * Enable all the tracepoints and add this probe's id to each 1229179193Sjb * tracepoint's list of active probes. 1230179193Sjb */ 1231179193Sjb for (i = 0; i < probe->ftp_ntps; i++) { 1232179193Sjb if ((rc = fasttrap_tracepoint_enable(p, probe, i)) != 0) { 1233179193Sjb /* 1234179193Sjb * If enabling the tracepoint failed completely, 1235179193Sjb * we don't have to disable it; if the failure 1236179193Sjb * was only partial we must disable it. 1237179193Sjb */ 1238179193Sjb if (rc == FASTTRAP_ENABLE_FAIL) 1239179193Sjb i--; 1240179193Sjb else 1241179193Sjb ASSERT(rc == FASTTRAP_ENABLE_PARTIAL); 1242179193Sjb 1243179193Sjb /* 1244179193Sjb * Back up and pull out all the tracepoints we've 1245179193Sjb * created so far for this probe. 1246179193Sjb */ 1247179193Sjb while (i >= 0) { 1248179193Sjb fasttrap_tracepoint_disable(p, probe, i); 1249179193Sjb i--; 1250179193Sjb } 1251179193Sjb 1252211738Srpaulo#if defined(sun) 1253179193Sjb mutex_enter(&p->p_lock); 1254179193Sjb sprunlock(p); 1255211738Srpaulo#else 1256212494Srpaulo PRELE(p); 1257211738Srpaulo#endif 1258179193Sjb 1259179193Sjb /* 1260179193Sjb * Since we're not actually enabling this probe, 1261179193Sjb * drop our reference on the trap table entry. 1262179193Sjb */ 1263179193Sjb fasttrap_disable_callbacks(); 1264179193Sjb return; 1265179193Sjb } 1266179193Sjb } 1267211738Srpaulo#if defined(sun) 1268179193Sjb mutex_enter(&p->p_lock); 1269179193Sjb sprunlock(p); 1270211738Srpaulo#else 1271212494Srpaulo PRELE(p); 1272211738Srpaulo#endif 1273179193Sjb 1274179193Sjb probe->ftp_enabled = 1; 1275179193Sjb} 1276179193Sjb 1277179193Sjb/*ARGSUSED*/ 1278179193Sjbstatic void 1279179193Sjbfasttrap_pid_disable(void *arg, dtrace_id_t id, void *parg) 1280179193Sjb{ 1281179193Sjb fasttrap_probe_t *probe = parg; 1282179193Sjb fasttrap_provider_t *provider = probe->ftp_prov; 1283179193Sjb proc_t *p; 1284179193Sjb int i, whack = 0; 1285179193Sjb 1286179193Sjb ASSERT(id == probe->ftp_id); 1287179193Sjb 1288211738Srpaulo mutex_enter(&provider->ftp_mtx); 1289211738Srpaulo 1290179193Sjb /* 1291179193Sjb * We won't be able to acquire a /proc-esque lock on the process 1292179193Sjb * iff the process is dead and gone. In this case, we rely on the 1293179193Sjb * provider lock as a point of mutual exclusion to prevent other 1294179193Sjb * DTrace consumers from disabling this probe. 1295179193Sjb */ 1296247049Sgibbs if ((p = pfind(probe->ftp_pid)) != NULL) { 1297212494Srpaulo#ifdef __FreeBSD__ 1298247049Sgibbs _PHOLD(p); 1299247049Sgibbs PROC_UNLOCK(p); 1300212494Srpaulo#endif 1301247049Sgibbs } 1302179193Sjb 1303179193Sjb /* 1304179193Sjb * Disable all the associated tracepoints (for fully enabled probes). 1305179193Sjb */ 1306179193Sjb if (probe->ftp_enabled) { 1307179193Sjb for (i = 0; i < probe->ftp_ntps; i++) { 1308179193Sjb fasttrap_tracepoint_disable(p, probe, i); 1309179193Sjb } 1310179193Sjb } 1311179193Sjb 1312179193Sjb ASSERT(provider->ftp_rcount > 0); 1313179193Sjb provider->ftp_rcount--; 1314179193Sjb 1315179193Sjb if (p != NULL) { 1316179193Sjb /* 1317179193Sjb * Even though we may not be able to remove it entirely, we 1318179193Sjb * mark this retired provider to get a chance to remove some 1319179193Sjb * of the associated probes. 1320179193Sjb */ 1321179193Sjb if (provider->ftp_retired && !provider->ftp_marked) 1322179193Sjb whack = provider->ftp_marked = 1; 1323179193Sjb mutex_exit(&provider->ftp_mtx); 1324179193Sjb } else { 1325179193Sjb /* 1326179193Sjb * If the process is dead, we're just waiting for the 1327179193Sjb * last probe to be disabled to be able to free it. 1328179193Sjb */ 1329179193Sjb if (provider->ftp_rcount == 0 && !provider->ftp_marked) 1330179193Sjb whack = provider->ftp_marked = 1; 1331179193Sjb mutex_exit(&provider->ftp_mtx); 1332179193Sjb } 1333179193Sjb 1334179193Sjb if (whack) 1335179193Sjb fasttrap_pid_cleanup(); 1336179193Sjb 1337212494Srpaulo#ifdef __FreeBSD__ 1338247049Sgibbs if (p != NULL) 1339247049Sgibbs PRELE(p); 1340212494Srpaulo#endif 1341179193Sjb if (!probe->ftp_enabled) 1342179193Sjb return; 1343179193Sjb 1344179193Sjb probe->ftp_enabled = 0; 1345179193Sjb 1346211738Srpaulo#if defined(sun) 1347179193Sjb ASSERT(MUTEX_HELD(&cpu_lock)); 1348211738Srpaulo#endif 1349179193Sjb fasttrap_disable_callbacks(); 1350179193Sjb} 1351179193Sjb 1352179193Sjb/*ARGSUSED*/ 1353179193Sjbstatic void 1354179193Sjbfasttrap_pid_getargdesc(void *arg, dtrace_id_t id, void *parg, 1355179193Sjb dtrace_argdesc_t *desc) 1356179193Sjb{ 1357179193Sjb fasttrap_probe_t *probe = parg; 1358179193Sjb char *str; 1359179193Sjb int i, ndx; 1360179193Sjb 1361179193Sjb desc->dtargd_native[0] = '\0'; 1362179193Sjb desc->dtargd_xlate[0] = '\0'; 1363179193Sjb 1364179193Sjb if (probe->ftp_prov->ftp_retired != 0 || 1365179193Sjb desc->dtargd_ndx >= probe->ftp_nargs) { 1366179193Sjb desc->dtargd_ndx = DTRACE_ARGNONE; 1367179193Sjb return; 1368179193Sjb } 1369179193Sjb 1370179193Sjb ndx = (probe->ftp_argmap != NULL) ? 1371179193Sjb probe->ftp_argmap[desc->dtargd_ndx] : desc->dtargd_ndx; 1372179193Sjb 1373179193Sjb str = probe->ftp_ntypes; 1374179193Sjb for (i = 0; i < ndx; i++) { 1375179193Sjb str += strlen(str) + 1; 1376179193Sjb } 1377179193Sjb 1378179193Sjb ASSERT(strlen(str + 1) < sizeof (desc->dtargd_native)); 1379179193Sjb (void) strcpy(desc->dtargd_native, str); 1380179193Sjb 1381179193Sjb if (probe->ftp_xtypes == NULL) 1382179193Sjb return; 1383179193Sjb 1384179193Sjb str = probe->ftp_xtypes; 1385179193Sjb for (i = 0; i < desc->dtargd_ndx; i++) { 1386179193Sjb str += strlen(str) + 1; 1387179193Sjb } 1388179193Sjb 1389179193Sjb ASSERT(strlen(str + 1) < sizeof (desc->dtargd_xlate)); 1390179193Sjb (void) strcpy(desc->dtargd_xlate, str); 1391179193Sjb} 1392179193Sjb 1393179193Sjb/*ARGSUSED*/ 1394179193Sjbstatic void 1395179193Sjbfasttrap_pid_destroy(void *arg, dtrace_id_t id, void *parg) 1396179193Sjb{ 1397179193Sjb fasttrap_probe_t *probe = parg; 1398179193Sjb int i; 1399179193Sjb size_t size; 1400179193Sjb 1401179193Sjb ASSERT(probe != NULL); 1402179193Sjb ASSERT(!probe->ftp_enabled); 1403179193Sjb ASSERT(fasttrap_total >= probe->ftp_ntps); 1404179193Sjb 1405179193Sjb atomic_add_32(&fasttrap_total, -probe->ftp_ntps); 1406179193Sjb size = offsetof(fasttrap_probe_t, ftp_tps[probe->ftp_ntps]); 1407179193Sjb 1408179193Sjb if (probe->ftp_gen + 1 >= fasttrap_mod_gen) 1409179193Sjb fasttrap_mod_barrier(probe->ftp_gen); 1410179193Sjb 1411179193Sjb for (i = 0; i < probe->ftp_ntps; i++) { 1412179193Sjb kmem_free(probe->ftp_tps[i].fit_tp, 1413179193Sjb sizeof (fasttrap_tracepoint_t)); 1414179193Sjb } 1415179193Sjb 1416179193Sjb kmem_free(probe, size); 1417179193Sjb} 1418179193Sjb 1419179193Sjb 1420179193Sjbstatic const dtrace_pattr_t pid_attr = { 1421179193Sjb{ DTRACE_STABILITY_EVOLVING, DTRACE_STABILITY_EVOLVING, DTRACE_CLASS_ISA }, 1422179193Sjb{ DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_UNKNOWN }, 1423179193Sjb{ DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_UNKNOWN }, 1424179193Sjb{ DTRACE_STABILITY_EVOLVING, DTRACE_STABILITY_EVOLVING, DTRACE_CLASS_ISA }, 1425179193Sjb{ DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_UNKNOWN }, 1426179193Sjb}; 1427179193Sjb 1428179193Sjbstatic dtrace_pops_t pid_pops = { 1429179193Sjb fasttrap_pid_provide, 1430179193Sjb NULL, 1431179193Sjb fasttrap_pid_enable, 1432179193Sjb fasttrap_pid_disable, 1433179193Sjb NULL, 1434179193Sjb NULL, 1435179193Sjb fasttrap_pid_getargdesc, 1436179193Sjb fasttrap_pid_getarg, 1437179193Sjb NULL, 1438179193Sjb fasttrap_pid_destroy 1439179193Sjb}; 1440179193Sjb 1441179193Sjbstatic dtrace_pops_t usdt_pops = { 1442179193Sjb fasttrap_pid_provide, 1443179193Sjb NULL, 1444179193Sjb fasttrap_pid_enable, 1445179193Sjb fasttrap_pid_disable, 1446179193Sjb NULL, 1447179193Sjb NULL, 1448179193Sjb fasttrap_pid_getargdesc, 1449179193Sjb fasttrap_usdt_getarg, 1450179193Sjb NULL, 1451179193Sjb fasttrap_pid_destroy 1452179193Sjb}; 1453179193Sjb 1454179193Sjbstatic fasttrap_proc_t * 1455179193Sjbfasttrap_proc_lookup(pid_t pid) 1456179193Sjb{ 1457179193Sjb fasttrap_bucket_t *bucket; 1458179193Sjb fasttrap_proc_t *fprc, *new_fprc; 1459179193Sjb 1460211738Srpaulo 1461179193Sjb bucket = &fasttrap_procs.fth_table[FASTTRAP_PROCS_INDEX(pid)]; 1462179193Sjb mutex_enter(&bucket->ftb_mtx); 1463179193Sjb 1464179193Sjb for (fprc = bucket->ftb_data; fprc != NULL; fprc = fprc->ftpc_next) { 1465179193Sjb if (fprc->ftpc_pid == pid && fprc->ftpc_acount != 0) { 1466179193Sjb mutex_enter(&fprc->ftpc_mtx); 1467179193Sjb mutex_exit(&bucket->ftb_mtx); 1468179193Sjb fprc->ftpc_rcount++; 1469179193Sjb atomic_add_64(&fprc->ftpc_acount, 1); 1470179198Sjb ASSERT(fprc->ftpc_acount <= fprc->ftpc_rcount); 1471179193Sjb mutex_exit(&fprc->ftpc_mtx); 1472179193Sjb 1473179193Sjb return (fprc); 1474179193Sjb } 1475179193Sjb } 1476179193Sjb 1477179193Sjb /* 1478179193Sjb * Drop the bucket lock so we don't try to perform a sleeping 1479179193Sjb * allocation under it. 1480179193Sjb */ 1481179193Sjb mutex_exit(&bucket->ftb_mtx); 1482179193Sjb 1483179193Sjb new_fprc = kmem_zalloc(sizeof (fasttrap_proc_t), KM_SLEEP); 1484179193Sjb new_fprc->ftpc_pid = pid; 1485179193Sjb new_fprc->ftpc_rcount = 1; 1486179193Sjb new_fprc->ftpc_acount = 1; 1487211738Srpaulo#if !defined(sun) 1488211738Srpaulo mutex_init(&new_fprc->ftpc_mtx, "fasttrap proc mtx", MUTEX_DEFAULT, 1489211738Srpaulo NULL); 1490211738Srpaulo#endif 1491179193Sjb 1492179193Sjb mutex_enter(&bucket->ftb_mtx); 1493179193Sjb 1494179193Sjb /* 1495179193Sjb * Take another lap through the list to make sure a proc hasn't 1496179193Sjb * been created for this pid while we weren't under the bucket lock. 1497179193Sjb */ 1498179193Sjb for (fprc = bucket->ftb_data; fprc != NULL; fprc = fprc->ftpc_next) { 1499179193Sjb if (fprc->ftpc_pid == pid && fprc->ftpc_acount != 0) { 1500179193Sjb mutex_enter(&fprc->ftpc_mtx); 1501179193Sjb mutex_exit(&bucket->ftb_mtx); 1502179193Sjb fprc->ftpc_rcount++; 1503179193Sjb atomic_add_64(&fprc->ftpc_acount, 1); 1504179198Sjb ASSERT(fprc->ftpc_acount <= fprc->ftpc_rcount); 1505179193Sjb mutex_exit(&fprc->ftpc_mtx); 1506179193Sjb 1507179193Sjb kmem_free(new_fprc, sizeof (fasttrap_proc_t)); 1508179193Sjb 1509179193Sjb return (fprc); 1510179193Sjb } 1511179193Sjb } 1512179193Sjb 1513179193Sjb new_fprc->ftpc_next = bucket->ftb_data; 1514179193Sjb bucket->ftb_data = new_fprc; 1515179193Sjb 1516179193Sjb mutex_exit(&bucket->ftb_mtx); 1517179193Sjb 1518179193Sjb return (new_fprc); 1519179193Sjb} 1520179193Sjb 1521179193Sjbstatic void 1522179193Sjbfasttrap_proc_release(fasttrap_proc_t *proc) 1523179193Sjb{ 1524179193Sjb fasttrap_bucket_t *bucket; 1525179193Sjb fasttrap_proc_t *fprc, **fprcp; 1526179193Sjb pid_t pid = proc->ftpc_pid; 1527264434Smarkj#if !defined(sun) 1528264434Smarkj fasttrap_scrblock_t *scrblk, *scrblktmp; 1529264434Smarkj fasttrap_scrspace_t *scrspc, *scrspctmp; 1530264434Smarkj struct proc *p; 1531264434Smarkj struct thread *td; 1532264434Smarkj#endif 1533179193Sjb 1534179193Sjb mutex_enter(&proc->ftpc_mtx); 1535179193Sjb 1536179193Sjb ASSERT(proc->ftpc_rcount != 0); 1537179198Sjb ASSERT(proc->ftpc_acount <= proc->ftpc_rcount); 1538179193Sjb 1539179193Sjb if (--proc->ftpc_rcount != 0) { 1540179193Sjb mutex_exit(&proc->ftpc_mtx); 1541179193Sjb return; 1542179193Sjb } 1543179193Sjb 1544264434Smarkj#if !defined(sun) 1545264434Smarkj /* 1546264434Smarkj * Free all structures used to manage per-thread scratch space. 1547264434Smarkj */ 1548264434Smarkj LIST_FOREACH_SAFE(scrblk, &proc->ftpc_scrblks, ftsb_next, 1549264434Smarkj scrblktmp) { 1550264434Smarkj LIST_REMOVE(scrblk, ftsb_next); 1551264434Smarkj free(scrblk, M_SOLARIS); 1552264434Smarkj } 1553264434Smarkj LIST_FOREACH_SAFE(scrspc, &proc->ftpc_fscr, ftss_next, scrspctmp) { 1554264434Smarkj LIST_REMOVE(scrspc, ftss_next); 1555264434Smarkj free(scrspc, M_SOLARIS); 1556264434Smarkj } 1557264434Smarkj LIST_FOREACH_SAFE(scrspc, &proc->ftpc_ascr, ftss_next, scrspctmp) { 1558264434Smarkj LIST_REMOVE(scrspc, ftss_next); 1559264434Smarkj free(scrspc, M_SOLARIS); 1560264434Smarkj } 1561264434Smarkj 1562264434Smarkj if ((p = pfind(pid)) != NULL) { 1563264434Smarkj FOREACH_THREAD_IN_PROC(p, td) 1564264434Smarkj td->t_dtrace_sscr = NULL; 1565264434Smarkj PROC_UNLOCK(p); 1566264434Smarkj } 1567264434Smarkj#endif 1568264434Smarkj 1569179193Sjb mutex_exit(&proc->ftpc_mtx); 1570179193Sjb 1571179193Sjb /* 1572179193Sjb * There should definitely be no live providers associated with this 1573179193Sjb * process at this point. 1574179193Sjb */ 1575179193Sjb ASSERT(proc->ftpc_acount == 0); 1576179193Sjb 1577179193Sjb bucket = &fasttrap_procs.fth_table[FASTTRAP_PROCS_INDEX(pid)]; 1578179193Sjb mutex_enter(&bucket->ftb_mtx); 1579179193Sjb 1580179193Sjb fprcp = (fasttrap_proc_t **)&bucket->ftb_data; 1581179193Sjb while ((fprc = *fprcp) != NULL) { 1582179193Sjb if (fprc == proc) 1583179193Sjb break; 1584179193Sjb 1585179193Sjb fprcp = &fprc->ftpc_next; 1586179193Sjb } 1587179193Sjb 1588179193Sjb /* 1589179193Sjb * Something strange has happened if we can't find the proc. 1590179193Sjb */ 1591179193Sjb ASSERT(fprc != NULL); 1592179193Sjb 1593179193Sjb *fprcp = fprc->ftpc_next; 1594179193Sjb 1595179193Sjb mutex_exit(&bucket->ftb_mtx); 1596179193Sjb 1597179193Sjb kmem_free(fprc, sizeof (fasttrap_proc_t)); 1598179193Sjb} 1599179193Sjb 1600179193Sjb/* 1601179193Sjb * Lookup a fasttrap-managed provider based on its name and associated pid. 1602179193Sjb * If the pattr argument is non-NULL, this function instantiates the provider 1603179193Sjb * if it doesn't exist otherwise it returns NULL. The provider is returned 1604179193Sjb * with its lock held. 1605179193Sjb */ 1606179193Sjbstatic fasttrap_provider_t * 1607179193Sjbfasttrap_provider_lookup(pid_t pid, const char *name, 1608179193Sjb const dtrace_pattr_t *pattr) 1609179193Sjb{ 1610179193Sjb fasttrap_provider_t *fp, *new_fp = NULL; 1611179193Sjb fasttrap_bucket_t *bucket; 1612179193Sjb char provname[DTRACE_PROVNAMELEN]; 1613179193Sjb proc_t *p; 1614179193Sjb cred_t *cred; 1615179193Sjb 1616179193Sjb ASSERT(strlen(name) < sizeof (fp->ftp_name)); 1617179193Sjb ASSERT(pattr != NULL); 1618179193Sjb 1619179193Sjb bucket = &fasttrap_provs.fth_table[FASTTRAP_PROVS_INDEX(pid, name)]; 1620179193Sjb mutex_enter(&bucket->ftb_mtx); 1621179193Sjb 1622179193Sjb /* 1623179193Sjb * Take a lap through the list and return the match if we find it. 1624179193Sjb */ 1625179193Sjb for (fp = bucket->ftb_data; fp != NULL; fp = fp->ftp_next) { 1626179193Sjb if (fp->ftp_pid == pid && strcmp(fp->ftp_name, name) == 0 && 1627179193Sjb !fp->ftp_retired) { 1628179193Sjb mutex_enter(&fp->ftp_mtx); 1629179193Sjb mutex_exit(&bucket->ftb_mtx); 1630179193Sjb return (fp); 1631179193Sjb } 1632179193Sjb } 1633179193Sjb 1634179193Sjb /* 1635179193Sjb * Drop the bucket lock so we don't try to perform a sleeping 1636179193Sjb * allocation under it. 1637179193Sjb */ 1638179193Sjb mutex_exit(&bucket->ftb_mtx); 1639179193Sjb 1640179193Sjb /* 1641179193Sjb * Make sure the process exists, isn't a child created as the result 1642179193Sjb * of a vfork(2), and isn't a zombie (but may be in fork). 1643179193Sjb */ 1644211738Srpaulo if ((p = pfind(pid)) == NULL) 1645179193Sjb return (NULL); 1646179193Sjb 1647179193Sjb /* 1648179193Sjb * Increment p_dtrace_probes so that the process knows to inform us 1649179193Sjb * when it exits or execs. fasttrap_provider_free() decrements this 1650179193Sjb * when we're done with this provider. 1651179193Sjb */ 1652179193Sjb p->p_dtrace_probes++; 1653179193Sjb 1654179193Sjb /* 1655179193Sjb * Grab the credentials for this process so we have 1656179193Sjb * something to pass to dtrace_register(). 1657179193Sjb */ 1658211738Srpaulo PROC_LOCK_ASSERT(p, MA_OWNED); 1659211738Srpaulo crhold(p->p_ucred); 1660211738Srpaulo cred = p->p_ucred; 1661211738Srpaulo PROC_UNLOCK(p); 1662179193Sjb 1663179193Sjb new_fp = kmem_zalloc(sizeof (fasttrap_provider_t), KM_SLEEP); 1664179193Sjb new_fp->ftp_pid = pid; 1665179193Sjb new_fp->ftp_proc = fasttrap_proc_lookup(pid); 1666211738Srpaulo#if !defined(sun) 1667211738Srpaulo mutex_init(&new_fp->ftp_mtx, "provider mtx", MUTEX_DEFAULT, NULL); 1668211738Srpaulo mutex_init(&new_fp->ftp_cmtx, "lock on creating", MUTEX_DEFAULT, NULL); 1669211738Srpaulo#endif 1670179193Sjb 1671179193Sjb ASSERT(new_fp->ftp_proc != NULL); 1672179193Sjb 1673179193Sjb mutex_enter(&bucket->ftb_mtx); 1674179193Sjb 1675179193Sjb /* 1676179193Sjb * Take another lap through the list to make sure a provider hasn't 1677179193Sjb * been created for this pid while we weren't under the bucket lock. 1678179193Sjb */ 1679179193Sjb for (fp = bucket->ftb_data; fp != NULL; fp = fp->ftp_next) { 1680179193Sjb if (fp->ftp_pid == pid && strcmp(fp->ftp_name, name) == 0 && 1681179193Sjb !fp->ftp_retired) { 1682179193Sjb mutex_enter(&fp->ftp_mtx); 1683179193Sjb mutex_exit(&bucket->ftb_mtx); 1684179193Sjb fasttrap_provider_free(new_fp); 1685179193Sjb crfree(cred); 1686179193Sjb return (fp); 1687179193Sjb } 1688179193Sjb } 1689179193Sjb 1690179193Sjb (void) strcpy(new_fp->ftp_name, name); 1691179193Sjb 1692179193Sjb /* 1693179193Sjb * Fail and return NULL if either the provider name is too long 1694179193Sjb * or we fail to register this new provider with the DTrace 1695179193Sjb * framework. Note that this is the only place we ever construct 1696179193Sjb * the full provider name -- we keep it in pieces in the provider 1697179193Sjb * structure. 1698179193Sjb */ 1699179193Sjb if (snprintf(provname, sizeof (provname), "%s%u", name, (uint_t)pid) >= 1700179193Sjb sizeof (provname) || 1701179193Sjb dtrace_register(provname, pattr, 1702179193Sjb DTRACE_PRIV_PROC | DTRACE_PRIV_OWNER | DTRACE_PRIV_ZONEOWNER, cred, 1703179193Sjb pattr == &pid_attr ? &pid_pops : &usdt_pops, new_fp, 1704179193Sjb &new_fp->ftp_provid) != 0) { 1705179193Sjb mutex_exit(&bucket->ftb_mtx); 1706179193Sjb fasttrap_provider_free(new_fp); 1707179193Sjb crfree(cred); 1708179193Sjb return (NULL); 1709179193Sjb } 1710179193Sjb 1711179193Sjb new_fp->ftp_next = bucket->ftb_data; 1712179193Sjb bucket->ftb_data = new_fp; 1713179193Sjb 1714179193Sjb mutex_enter(&new_fp->ftp_mtx); 1715179193Sjb mutex_exit(&bucket->ftb_mtx); 1716179193Sjb 1717179193Sjb crfree(cred); 1718179193Sjb return (new_fp); 1719179193Sjb} 1720179193Sjb 1721179193Sjbstatic void 1722179193Sjbfasttrap_provider_free(fasttrap_provider_t *provider) 1723179193Sjb{ 1724179193Sjb pid_t pid = provider->ftp_pid; 1725179193Sjb proc_t *p; 1726179193Sjb 1727179193Sjb /* 1728179193Sjb * There need to be no associated enabled probes, no consumers 1729179193Sjb * creating probes, and no meta providers referencing this provider. 1730179193Sjb */ 1731179193Sjb ASSERT(provider->ftp_rcount == 0); 1732179193Sjb ASSERT(provider->ftp_ccount == 0); 1733179193Sjb ASSERT(provider->ftp_mcount == 0); 1734179193Sjb 1735179198Sjb /* 1736179198Sjb * If this provider hasn't been retired, we need to explicitly drop the 1737179198Sjb * count of active providers on the associated process structure. 1738179198Sjb */ 1739179198Sjb if (!provider->ftp_retired) { 1740179198Sjb atomic_add_64(&provider->ftp_proc->ftpc_acount, -1); 1741179198Sjb ASSERT(provider->ftp_proc->ftpc_acount < 1742179198Sjb provider->ftp_proc->ftpc_rcount); 1743179198Sjb } 1744179198Sjb 1745179193Sjb fasttrap_proc_release(provider->ftp_proc); 1746179193Sjb 1747211738Srpaulo#if !defined(sun) 1748211738Srpaulo mutex_destroy(&provider->ftp_mtx); 1749211738Srpaulo mutex_destroy(&provider->ftp_cmtx); 1750211738Srpaulo#endif 1751179193Sjb kmem_free(provider, sizeof (fasttrap_provider_t)); 1752179193Sjb 1753179193Sjb /* 1754179193Sjb * Decrement p_dtrace_probes on the process whose provider we're 1755179193Sjb * freeing. We don't have to worry about clobbering somone else's 1756179193Sjb * modifications to it because we have locked the bucket that 1757179193Sjb * corresponds to this process's hash chain in the provider hash 1758179193Sjb * table. Don't sweat it if we can't find the process. 1759179193Sjb */ 1760211738Srpaulo if ((p = pfind(pid)) == NULL) { 1761179193Sjb return; 1762179193Sjb } 1763179193Sjb 1764179193Sjb p->p_dtrace_probes--; 1765211738Srpaulo#if !defined(sun) 1766211738Srpaulo PROC_UNLOCK(p); 1767211738Srpaulo#endif 1768179193Sjb} 1769179193Sjb 1770179193Sjbstatic void 1771179193Sjbfasttrap_provider_retire(pid_t pid, const char *name, int mprov) 1772179193Sjb{ 1773179193Sjb fasttrap_provider_t *fp; 1774179193Sjb fasttrap_bucket_t *bucket; 1775179193Sjb dtrace_provider_id_t provid; 1776179193Sjb 1777179193Sjb ASSERT(strlen(name) < sizeof (fp->ftp_name)); 1778179193Sjb 1779179193Sjb bucket = &fasttrap_provs.fth_table[FASTTRAP_PROVS_INDEX(pid, name)]; 1780179193Sjb mutex_enter(&bucket->ftb_mtx); 1781179193Sjb 1782179193Sjb for (fp = bucket->ftb_data; fp != NULL; fp = fp->ftp_next) { 1783179193Sjb if (fp->ftp_pid == pid && strcmp(fp->ftp_name, name) == 0 && 1784179193Sjb !fp->ftp_retired) 1785179193Sjb break; 1786179193Sjb } 1787179193Sjb 1788179193Sjb if (fp == NULL) { 1789179193Sjb mutex_exit(&bucket->ftb_mtx); 1790179193Sjb return; 1791179193Sjb } 1792179193Sjb 1793179193Sjb mutex_enter(&fp->ftp_mtx); 1794179193Sjb ASSERT(!mprov || fp->ftp_mcount > 0); 1795179193Sjb if (mprov && --fp->ftp_mcount != 0) { 1796179193Sjb mutex_exit(&fp->ftp_mtx); 1797179193Sjb mutex_exit(&bucket->ftb_mtx); 1798179193Sjb return; 1799179193Sjb } 1800179193Sjb 1801179193Sjb /* 1802179193Sjb * Mark the provider to be removed in our post-processing step, mark it 1803179193Sjb * retired, and drop the active count on its proc. Marking it indicates 1804179193Sjb * that we should try to remove it; setting the retired flag indicates 1805179193Sjb * that we're done with this provider; dropping the active the proc 1806179193Sjb * releases our hold, and when this reaches zero (as it will during 1807179193Sjb * exit or exec) the proc and associated providers become defunct. 1808179193Sjb * 1809179193Sjb * We obviously need to take the bucket lock before the provider lock 1810179193Sjb * to perform the lookup, but we need to drop the provider lock 1811179193Sjb * before calling into the DTrace framework since we acquire the 1812179193Sjb * provider lock in callbacks invoked from the DTrace framework. The 1813179193Sjb * bucket lock therefore protects the integrity of the provider hash 1814179193Sjb * table. 1815179193Sjb */ 1816179193Sjb atomic_add_64(&fp->ftp_proc->ftpc_acount, -1); 1817179198Sjb ASSERT(fp->ftp_proc->ftpc_acount < fp->ftp_proc->ftpc_rcount); 1818179198Sjb 1819179193Sjb fp->ftp_retired = 1; 1820179193Sjb fp->ftp_marked = 1; 1821179193Sjb provid = fp->ftp_provid; 1822179193Sjb mutex_exit(&fp->ftp_mtx); 1823179193Sjb 1824179193Sjb /* 1825179193Sjb * We don't have to worry about invalidating the same provider twice 1826179193Sjb * since fasttrap_provider_lookup() will ignore provider that have 1827179193Sjb * been marked as retired. 1828179193Sjb */ 1829179193Sjb dtrace_invalidate(provid); 1830179193Sjb 1831179193Sjb mutex_exit(&bucket->ftb_mtx); 1832179193Sjb 1833179193Sjb fasttrap_pid_cleanup(); 1834179193Sjb} 1835179193Sjb 1836179193Sjbstatic int 1837179193Sjbfasttrap_uint32_cmp(const void *ap, const void *bp) 1838179193Sjb{ 1839179193Sjb return (*(const uint32_t *)ap - *(const uint32_t *)bp); 1840179193Sjb} 1841179193Sjb 1842179193Sjbstatic int 1843179193Sjbfasttrap_uint64_cmp(const void *ap, const void *bp) 1844179193Sjb{ 1845179193Sjb return (*(const uint64_t *)ap - *(const uint64_t *)bp); 1846179193Sjb} 1847179193Sjb 1848179193Sjbstatic int 1849179193Sjbfasttrap_add_probe(fasttrap_probe_spec_t *pdata) 1850179193Sjb{ 1851179193Sjb fasttrap_provider_t *provider; 1852179193Sjb fasttrap_probe_t *pp; 1853179193Sjb fasttrap_tracepoint_t *tp; 1854179193Sjb char *name; 1855211738Srpaulo int i, aframes = 0, whack; 1856179193Sjb 1857179193Sjb /* 1858179193Sjb * There needs to be at least one desired trace point. 1859179193Sjb */ 1860179193Sjb if (pdata->ftps_noffs == 0) 1861179193Sjb return (EINVAL); 1862179193Sjb 1863179193Sjb switch (pdata->ftps_type) { 1864179193Sjb case DTFTP_ENTRY: 1865179193Sjb name = "entry"; 1866179193Sjb aframes = FASTTRAP_ENTRY_AFRAMES; 1867179193Sjb break; 1868179193Sjb case DTFTP_RETURN: 1869179193Sjb name = "return"; 1870179193Sjb aframes = FASTTRAP_RETURN_AFRAMES; 1871179193Sjb break; 1872179193Sjb case DTFTP_OFFSETS: 1873179193Sjb name = NULL; 1874179193Sjb break; 1875179193Sjb default: 1876179193Sjb return (EINVAL); 1877179193Sjb } 1878179193Sjb 1879179193Sjb if ((provider = fasttrap_provider_lookup(pdata->ftps_pid, 1880179193Sjb FASTTRAP_PID_NAME, &pid_attr)) == NULL) 1881179193Sjb return (ESRCH); 1882179193Sjb 1883179193Sjb /* 1884179193Sjb * Increment this reference count to indicate that a consumer is 1885179193Sjb * actively adding a new probe associated with this provider. This 1886179193Sjb * prevents the provider from being deleted -- we'll need to check 1887179193Sjb * for pending deletions when we drop this reference count. 1888179193Sjb */ 1889179193Sjb provider->ftp_ccount++; 1890179193Sjb mutex_exit(&provider->ftp_mtx); 1891179193Sjb 1892179193Sjb /* 1893179193Sjb * Grab the creation lock to ensure consistency between calls to 1894179193Sjb * dtrace_probe_lookup() and dtrace_probe_create() in the face of 1895179193Sjb * other threads creating probes. We must drop the provider lock 1896179193Sjb * before taking this lock to avoid a three-way deadlock with the 1897179193Sjb * DTrace framework. 1898179193Sjb */ 1899179193Sjb mutex_enter(&provider->ftp_cmtx); 1900179193Sjb 1901179193Sjb if (name == NULL) { 1902179193Sjb for (i = 0; i < pdata->ftps_noffs; i++) { 1903179193Sjb char name_str[17]; 1904179193Sjb 1905179193Sjb (void) sprintf(name_str, "%llx", 1906179193Sjb (unsigned long long)pdata->ftps_offs[i]); 1907179193Sjb 1908179193Sjb if (dtrace_probe_lookup(provider->ftp_provid, 1909179193Sjb pdata->ftps_mod, pdata->ftps_func, name_str) != 0) 1910179193Sjb continue; 1911179193Sjb 1912179193Sjb atomic_add_32(&fasttrap_total, 1); 1913179193Sjb 1914179193Sjb if (fasttrap_total > fasttrap_max) { 1915179193Sjb atomic_add_32(&fasttrap_total, -1); 1916179193Sjb goto no_mem; 1917179193Sjb } 1918179193Sjb 1919179193Sjb pp = kmem_zalloc(sizeof (fasttrap_probe_t), KM_SLEEP); 1920179193Sjb 1921179193Sjb pp->ftp_prov = provider; 1922179193Sjb pp->ftp_faddr = pdata->ftps_pc; 1923179193Sjb pp->ftp_fsize = pdata->ftps_size; 1924179193Sjb pp->ftp_pid = pdata->ftps_pid; 1925179193Sjb pp->ftp_ntps = 1; 1926179193Sjb 1927179193Sjb tp = kmem_zalloc(sizeof (fasttrap_tracepoint_t), 1928179193Sjb KM_SLEEP); 1929179193Sjb 1930179193Sjb tp->ftt_proc = provider->ftp_proc; 1931179193Sjb tp->ftt_pc = pdata->ftps_offs[i] + pdata->ftps_pc; 1932179193Sjb tp->ftt_pid = pdata->ftps_pid; 1933179193Sjb 1934179193Sjb pp->ftp_tps[0].fit_tp = tp; 1935179193Sjb pp->ftp_tps[0].fit_id.fti_probe = pp; 1936179193Sjb pp->ftp_tps[0].fit_id.fti_ptype = pdata->ftps_type; 1937179193Sjb 1938179193Sjb pp->ftp_id = dtrace_probe_create(provider->ftp_provid, 1939179193Sjb pdata->ftps_mod, pdata->ftps_func, name_str, 1940179193Sjb FASTTRAP_OFFSET_AFRAMES, pp); 1941179193Sjb } 1942179193Sjb 1943179193Sjb } else if (dtrace_probe_lookup(provider->ftp_provid, pdata->ftps_mod, 1944179193Sjb pdata->ftps_func, name) == 0) { 1945179193Sjb atomic_add_32(&fasttrap_total, pdata->ftps_noffs); 1946179193Sjb 1947179193Sjb if (fasttrap_total > fasttrap_max) { 1948179193Sjb atomic_add_32(&fasttrap_total, -pdata->ftps_noffs); 1949179193Sjb goto no_mem; 1950179193Sjb } 1951179193Sjb 1952179193Sjb /* 1953179193Sjb * Make sure all tracepoint program counter values are unique. 1954179193Sjb * We later assume that each probe has exactly one tracepoint 1955179193Sjb * for a given pc. 1956179193Sjb */ 1957179193Sjb qsort(pdata->ftps_offs, pdata->ftps_noffs, 1958179193Sjb sizeof (uint64_t), fasttrap_uint64_cmp); 1959179193Sjb for (i = 1; i < pdata->ftps_noffs; i++) { 1960179193Sjb if (pdata->ftps_offs[i] > pdata->ftps_offs[i - 1]) 1961179193Sjb continue; 1962179193Sjb 1963179193Sjb atomic_add_32(&fasttrap_total, -pdata->ftps_noffs); 1964179193Sjb goto no_mem; 1965179193Sjb } 1966179193Sjb 1967179193Sjb ASSERT(pdata->ftps_noffs > 0); 1968179193Sjb pp = kmem_zalloc(offsetof(fasttrap_probe_t, 1969179193Sjb ftp_tps[pdata->ftps_noffs]), KM_SLEEP); 1970179193Sjb 1971179193Sjb pp->ftp_prov = provider; 1972179193Sjb pp->ftp_faddr = pdata->ftps_pc; 1973179193Sjb pp->ftp_fsize = pdata->ftps_size; 1974179193Sjb pp->ftp_pid = pdata->ftps_pid; 1975179193Sjb pp->ftp_ntps = pdata->ftps_noffs; 1976179193Sjb 1977179193Sjb for (i = 0; i < pdata->ftps_noffs; i++) { 1978179193Sjb tp = kmem_zalloc(sizeof (fasttrap_tracepoint_t), 1979179193Sjb KM_SLEEP); 1980179193Sjb 1981179193Sjb tp->ftt_proc = provider->ftp_proc; 1982179193Sjb tp->ftt_pc = pdata->ftps_offs[i] + pdata->ftps_pc; 1983179193Sjb tp->ftt_pid = pdata->ftps_pid; 1984179193Sjb 1985179193Sjb pp->ftp_tps[i].fit_tp = tp; 1986179193Sjb pp->ftp_tps[i].fit_id.fti_probe = pp; 1987179193Sjb pp->ftp_tps[i].fit_id.fti_ptype = pdata->ftps_type; 1988179193Sjb } 1989179193Sjb 1990179193Sjb pp->ftp_id = dtrace_probe_create(provider->ftp_provid, 1991179193Sjb pdata->ftps_mod, pdata->ftps_func, name, aframes, pp); 1992179193Sjb } 1993179193Sjb 1994179193Sjb mutex_exit(&provider->ftp_cmtx); 1995179193Sjb 1996179193Sjb /* 1997179193Sjb * We know that the provider is still valid since we incremented the 1998179193Sjb * creation reference count. If someone tried to clean up this provider 1999179193Sjb * while we were using it (e.g. because the process called exec(2) or 2000179193Sjb * exit(2)), take note of that and try to clean it up now. 2001179193Sjb */ 2002179193Sjb mutex_enter(&provider->ftp_mtx); 2003179193Sjb provider->ftp_ccount--; 2004179193Sjb whack = provider->ftp_retired; 2005179193Sjb mutex_exit(&provider->ftp_mtx); 2006179193Sjb 2007179193Sjb if (whack) 2008179193Sjb fasttrap_pid_cleanup(); 2009179193Sjb 2010179193Sjb return (0); 2011179193Sjb 2012179193Sjbno_mem: 2013179193Sjb /* 2014179193Sjb * If we've exhausted the allowable resources, we'll try to remove 2015179193Sjb * this provider to free some up. This is to cover the case where 2016179193Sjb * the user has accidentally created many more probes than was 2017179193Sjb * intended (e.g. pid123:::). 2018179193Sjb */ 2019179193Sjb mutex_exit(&provider->ftp_cmtx); 2020179193Sjb mutex_enter(&provider->ftp_mtx); 2021179193Sjb provider->ftp_ccount--; 2022179193Sjb provider->ftp_marked = 1; 2023179193Sjb mutex_exit(&provider->ftp_mtx); 2024179193Sjb 2025179193Sjb fasttrap_pid_cleanup(); 2026179193Sjb 2027179193Sjb return (ENOMEM); 2028179193Sjb} 2029179193Sjb 2030179193Sjb/*ARGSUSED*/ 2031179193Sjbstatic void * 2032179193Sjbfasttrap_meta_provide(void *arg, dtrace_helper_provdesc_t *dhpv, pid_t pid) 2033179193Sjb{ 2034179193Sjb fasttrap_provider_t *provider; 2035179193Sjb 2036179193Sjb /* 2037179193Sjb * A 32-bit unsigned integer (like a pid for example) can be 2038179193Sjb * expressed in 10 or fewer decimal digits. Make sure that we'll 2039179193Sjb * have enough space for the provider name. 2040179193Sjb */ 2041179193Sjb if (strlen(dhpv->dthpv_provname) + 10 >= 2042179193Sjb sizeof (provider->ftp_name)) { 2043211738Srpaulo printf("failed to instantiate provider %s: " 2044179193Sjb "name too long to accomodate pid", dhpv->dthpv_provname); 2045179193Sjb return (NULL); 2046179193Sjb } 2047179193Sjb 2048179193Sjb /* 2049179193Sjb * Don't let folks spoof the true pid provider. 2050179193Sjb */ 2051179193Sjb if (strcmp(dhpv->dthpv_provname, FASTTRAP_PID_NAME) == 0) { 2052211738Srpaulo printf("failed to instantiate provider %s: " 2053179193Sjb "%s is an invalid name", dhpv->dthpv_provname, 2054179193Sjb FASTTRAP_PID_NAME); 2055179193Sjb return (NULL); 2056179193Sjb } 2057179193Sjb 2058179193Sjb /* 2059179193Sjb * The highest stability class that fasttrap supports is ISA; cap 2060179193Sjb * the stability of the new provider accordingly. 2061179193Sjb */ 2062179193Sjb if (dhpv->dthpv_pattr.dtpa_provider.dtat_class > DTRACE_CLASS_ISA) 2063179193Sjb dhpv->dthpv_pattr.dtpa_provider.dtat_class = DTRACE_CLASS_ISA; 2064179193Sjb if (dhpv->dthpv_pattr.dtpa_mod.dtat_class > DTRACE_CLASS_ISA) 2065179193Sjb dhpv->dthpv_pattr.dtpa_mod.dtat_class = DTRACE_CLASS_ISA; 2066179193Sjb if (dhpv->dthpv_pattr.dtpa_func.dtat_class > DTRACE_CLASS_ISA) 2067179193Sjb dhpv->dthpv_pattr.dtpa_func.dtat_class = DTRACE_CLASS_ISA; 2068179193Sjb if (dhpv->dthpv_pattr.dtpa_name.dtat_class > DTRACE_CLASS_ISA) 2069179193Sjb dhpv->dthpv_pattr.dtpa_name.dtat_class = DTRACE_CLASS_ISA; 2070179193Sjb if (dhpv->dthpv_pattr.dtpa_args.dtat_class > DTRACE_CLASS_ISA) 2071179193Sjb dhpv->dthpv_pattr.dtpa_args.dtat_class = DTRACE_CLASS_ISA; 2072179193Sjb 2073179193Sjb if ((provider = fasttrap_provider_lookup(pid, dhpv->dthpv_provname, 2074179193Sjb &dhpv->dthpv_pattr)) == NULL) { 2075211738Srpaulo printf("failed to instantiate provider %s for " 2076179193Sjb "process %u", dhpv->dthpv_provname, (uint_t)pid); 2077179193Sjb return (NULL); 2078179193Sjb } 2079179193Sjb 2080179193Sjb /* 2081179193Sjb * Up the meta provider count so this provider isn't removed until 2082179193Sjb * the meta provider has been told to remove it. 2083179193Sjb */ 2084179193Sjb provider->ftp_mcount++; 2085179193Sjb 2086179193Sjb mutex_exit(&provider->ftp_mtx); 2087179193Sjb 2088179193Sjb return (provider); 2089179193Sjb} 2090179193Sjb 2091179193Sjb/*ARGSUSED*/ 2092179193Sjbstatic void 2093179193Sjbfasttrap_meta_create_probe(void *arg, void *parg, 2094179193Sjb dtrace_helper_probedesc_t *dhpb) 2095179193Sjb{ 2096179193Sjb fasttrap_provider_t *provider = parg; 2097179193Sjb fasttrap_probe_t *pp; 2098179193Sjb fasttrap_tracepoint_t *tp; 2099179193Sjb int i, j; 2100179193Sjb uint32_t ntps; 2101179193Sjb 2102179193Sjb /* 2103179193Sjb * Since the meta provider count is non-zero we don't have to worry 2104179193Sjb * about this provider disappearing. 2105179193Sjb */ 2106179193Sjb ASSERT(provider->ftp_mcount > 0); 2107179193Sjb 2108179193Sjb /* 2109179193Sjb * The offsets must be unique. 2110179193Sjb */ 2111179193Sjb qsort(dhpb->dthpb_offs, dhpb->dthpb_noffs, sizeof (uint32_t), 2112179193Sjb fasttrap_uint32_cmp); 2113179193Sjb for (i = 1; i < dhpb->dthpb_noffs; i++) { 2114179193Sjb if (dhpb->dthpb_base + dhpb->dthpb_offs[i] <= 2115179193Sjb dhpb->dthpb_base + dhpb->dthpb_offs[i - 1]) 2116179193Sjb return; 2117179193Sjb } 2118179193Sjb 2119179193Sjb qsort(dhpb->dthpb_enoffs, dhpb->dthpb_nenoffs, sizeof (uint32_t), 2120179193Sjb fasttrap_uint32_cmp); 2121179193Sjb for (i = 1; i < dhpb->dthpb_nenoffs; i++) { 2122179193Sjb if (dhpb->dthpb_base + dhpb->dthpb_enoffs[i] <= 2123179193Sjb dhpb->dthpb_base + dhpb->dthpb_enoffs[i - 1]) 2124179193Sjb return; 2125179193Sjb } 2126179193Sjb 2127179193Sjb /* 2128179193Sjb * Grab the creation lock to ensure consistency between calls to 2129179193Sjb * dtrace_probe_lookup() and dtrace_probe_create() in the face of 2130179193Sjb * other threads creating probes. 2131179193Sjb */ 2132179193Sjb mutex_enter(&provider->ftp_cmtx); 2133179193Sjb 2134179193Sjb if (dtrace_probe_lookup(provider->ftp_provid, dhpb->dthpb_mod, 2135179193Sjb dhpb->dthpb_func, dhpb->dthpb_name) != 0) { 2136179193Sjb mutex_exit(&provider->ftp_cmtx); 2137179193Sjb return; 2138179193Sjb } 2139179193Sjb 2140179193Sjb ntps = dhpb->dthpb_noffs + dhpb->dthpb_nenoffs; 2141179193Sjb ASSERT(ntps > 0); 2142179193Sjb 2143179193Sjb atomic_add_32(&fasttrap_total, ntps); 2144179193Sjb 2145179193Sjb if (fasttrap_total > fasttrap_max) { 2146179193Sjb atomic_add_32(&fasttrap_total, -ntps); 2147179193Sjb mutex_exit(&provider->ftp_cmtx); 2148179193Sjb return; 2149179193Sjb } 2150179193Sjb 2151179193Sjb pp = kmem_zalloc(offsetof(fasttrap_probe_t, ftp_tps[ntps]), KM_SLEEP); 2152179193Sjb 2153179193Sjb pp->ftp_prov = provider; 2154179193Sjb pp->ftp_pid = provider->ftp_pid; 2155179193Sjb pp->ftp_ntps = ntps; 2156179193Sjb pp->ftp_nargs = dhpb->dthpb_xargc; 2157179193Sjb pp->ftp_xtypes = dhpb->dthpb_xtypes; 2158179193Sjb pp->ftp_ntypes = dhpb->dthpb_ntypes; 2159179193Sjb 2160179193Sjb /* 2161179193Sjb * First create a tracepoint for each actual point of interest. 2162179193Sjb */ 2163179193Sjb for (i = 0; i < dhpb->dthpb_noffs; i++) { 2164179193Sjb tp = kmem_zalloc(sizeof (fasttrap_tracepoint_t), KM_SLEEP); 2165179193Sjb 2166179193Sjb tp->ftt_proc = provider->ftp_proc; 2167179193Sjb tp->ftt_pc = dhpb->dthpb_base + dhpb->dthpb_offs[i]; 2168179193Sjb tp->ftt_pid = provider->ftp_pid; 2169179193Sjb 2170179193Sjb pp->ftp_tps[i].fit_tp = tp; 2171179193Sjb pp->ftp_tps[i].fit_id.fti_probe = pp; 2172179193Sjb#ifdef __sparc 2173179193Sjb pp->ftp_tps[i].fit_id.fti_ptype = DTFTP_POST_OFFSETS; 2174179193Sjb#else 2175179193Sjb pp->ftp_tps[i].fit_id.fti_ptype = DTFTP_OFFSETS; 2176179193Sjb#endif 2177179193Sjb } 2178179193Sjb 2179179193Sjb /* 2180179193Sjb * Then create a tracepoint for each is-enabled point. 2181179193Sjb */ 2182179193Sjb for (j = 0; i < ntps; i++, j++) { 2183179193Sjb tp = kmem_zalloc(sizeof (fasttrap_tracepoint_t), KM_SLEEP); 2184179193Sjb 2185179193Sjb tp->ftt_proc = provider->ftp_proc; 2186179193Sjb tp->ftt_pc = dhpb->dthpb_base + dhpb->dthpb_enoffs[j]; 2187179193Sjb tp->ftt_pid = provider->ftp_pid; 2188179193Sjb 2189179193Sjb pp->ftp_tps[i].fit_tp = tp; 2190179193Sjb pp->ftp_tps[i].fit_id.fti_probe = pp; 2191179193Sjb pp->ftp_tps[i].fit_id.fti_ptype = DTFTP_IS_ENABLED; 2192179193Sjb } 2193179193Sjb 2194179193Sjb /* 2195179193Sjb * If the arguments are shuffled around we set the argument remapping 2196179193Sjb * table. Later, when the probe fires, we only remap the arguments 2197179193Sjb * if the table is non-NULL. 2198179193Sjb */ 2199179193Sjb for (i = 0; i < dhpb->dthpb_xargc; i++) { 2200179193Sjb if (dhpb->dthpb_args[i] != i) { 2201179193Sjb pp->ftp_argmap = dhpb->dthpb_args; 2202179193Sjb break; 2203179193Sjb } 2204179193Sjb } 2205179193Sjb 2206179193Sjb /* 2207179193Sjb * The probe is fully constructed -- register it with DTrace. 2208179193Sjb */ 2209179193Sjb pp->ftp_id = dtrace_probe_create(provider->ftp_provid, dhpb->dthpb_mod, 2210179193Sjb dhpb->dthpb_func, dhpb->dthpb_name, FASTTRAP_OFFSET_AFRAMES, pp); 2211179193Sjb 2212179193Sjb mutex_exit(&provider->ftp_cmtx); 2213179193Sjb} 2214179193Sjb 2215179193Sjb/*ARGSUSED*/ 2216179193Sjbstatic void 2217179193Sjbfasttrap_meta_remove(void *arg, dtrace_helper_provdesc_t *dhpv, pid_t pid) 2218179193Sjb{ 2219179193Sjb /* 2220179193Sjb * Clean up the USDT provider. There may be active consumers of the 2221179193Sjb * provider busy adding probes, no damage will actually befall the 2222179193Sjb * provider until that count has dropped to zero. This just puts 2223179193Sjb * the provider on death row. 2224179193Sjb */ 2225179193Sjb fasttrap_provider_retire(pid, dhpv->dthpv_provname, 1); 2226179193Sjb} 2227179193Sjb 2228179193Sjbstatic dtrace_mops_t fasttrap_mops = { 2229179193Sjb fasttrap_meta_create_probe, 2230179193Sjb fasttrap_meta_provide, 2231179193Sjb fasttrap_meta_remove 2232179193Sjb}; 2233179193Sjb 2234179193Sjb/*ARGSUSED*/ 2235179193Sjbstatic int 2236211738Srpaulofasttrap_open(struct cdev *dev __unused, int oflags __unused, 2237211738Srpaulo int devtype __unused, struct thread *td __unused) 2238179193Sjb{ 2239179193Sjb return (0); 2240179193Sjb} 2241179193Sjb 2242179193Sjb/*ARGSUSED*/ 2243179193Sjbstatic int 2244211738Srpaulofasttrap_ioctl(struct cdev *dev, u_long cmd, caddr_t arg, int fflag, 2245211738Srpaulo struct thread *td) 2246179193Sjb{ 2247211738Srpaulo#ifdef notyet 2248211738Srpaulo struct kinfo_proc kp; 2249211738Srpaulo const cred_t *cr = td->td_ucred; 2250211738Srpaulo#endif 2251179193Sjb if (!dtrace_attached()) 2252179193Sjb return (EAGAIN); 2253179193Sjb 2254179193Sjb if (cmd == FASTTRAPIOC_MAKEPROBE) { 2255258291Smarkj fasttrap_probe_spec_t *uprobe = *(fasttrap_probe_spec_t **)arg; 2256179193Sjb fasttrap_probe_spec_t *probe; 2257179193Sjb uint64_t noffs; 2258179193Sjb size_t size; 2259179193Sjb int ret; 2260179193Sjb char *c; 2261179193Sjb 2262179193Sjb if (copyin(&uprobe->ftps_noffs, &noffs, 2263179193Sjb sizeof (uprobe->ftps_noffs))) 2264179193Sjb return (EFAULT); 2265179193Sjb 2266179193Sjb /* 2267179193Sjb * Probes must have at least one tracepoint. 2268179193Sjb */ 2269179193Sjb if (noffs == 0) 2270179193Sjb return (EINVAL); 2271179193Sjb 2272179193Sjb size = sizeof (fasttrap_probe_spec_t) + 2273179193Sjb sizeof (probe->ftps_offs[0]) * (noffs - 1); 2274179193Sjb 2275179193Sjb if (size > 1024 * 1024) 2276179193Sjb return (ENOMEM); 2277179193Sjb 2278179193Sjb probe = kmem_alloc(size, KM_SLEEP); 2279179193Sjb 2280179193Sjb if (copyin(uprobe, probe, size) != 0) { 2281179193Sjb kmem_free(probe, size); 2282179193Sjb return (EFAULT); 2283179193Sjb } 2284179193Sjb 2285179193Sjb /* 2286179193Sjb * Verify that the function and module strings contain no 2287179193Sjb * funny characters. 2288179193Sjb */ 2289179193Sjb for (c = &probe->ftps_func[0]; *c != '\0'; c++) { 2290179193Sjb if (*c < 0x20 || 0x7f <= *c) { 2291179193Sjb ret = EINVAL; 2292179193Sjb goto err; 2293179193Sjb } 2294179193Sjb } 2295179193Sjb 2296179193Sjb for (c = &probe->ftps_mod[0]; *c != '\0'; c++) { 2297179193Sjb if (*c < 0x20 || 0x7f <= *c) { 2298179193Sjb ret = EINVAL; 2299179193Sjb goto err; 2300179193Sjb } 2301179193Sjb } 2302179193Sjb 2303211738Srpaulo#ifdef notyet 2304179193Sjb if (!PRIV_POLICY_CHOICE(cr, PRIV_ALL, B_FALSE)) { 2305179193Sjb proc_t *p; 2306179193Sjb pid_t pid = probe->ftps_pid; 2307179193Sjb 2308211738Srpaulo#if defined(sun) 2309179193Sjb mutex_enter(&pidlock); 2310211738Srpaulo#endif 2311179193Sjb /* 2312179193Sjb * Report an error if the process doesn't exist 2313179193Sjb * or is actively being birthed. 2314179193Sjb */ 2315211738Srpaulo p = pfind(pid); 2316211738Srpaulo if (p) 2317211738Srpaulo fill_kinfo_proc(p, &kp); 2318211738Srpaulo if (p == NULL || kp.ki_stat == SIDL) { 2319211738Srpaulo#if defined(sun) 2320179193Sjb mutex_exit(&pidlock); 2321211738Srpaulo#endif 2322179193Sjb return (ESRCH); 2323179193Sjb } 2324211738Srpaulo#if defined(sun) 2325179193Sjb mutex_enter(&p->p_lock); 2326179193Sjb mutex_exit(&pidlock); 2327211738Srpaulo#else 2328211738Srpaulo PROC_LOCK_ASSERT(p, MA_OWNED); 2329211738Srpaulo#endif 2330179193Sjb 2331211738Srpaulo#ifdef notyet 2332179193Sjb if ((ret = priv_proc_cred_perm(cr, p, NULL, 2333179193Sjb VREAD | VWRITE)) != 0) { 2334211738Srpaulo#if defined(sun) 2335179193Sjb mutex_exit(&p->p_lock); 2336211738Srpaulo#else 2337211738Srpaulo PROC_UNLOCK(p); 2338211738Srpaulo#endif 2339179193Sjb return (ret); 2340179193Sjb } 2341211738Srpaulo#endif /* notyet */ 2342211738Srpaulo#if defined(sun) 2343179193Sjb mutex_exit(&p->p_lock); 2344211738Srpaulo#else 2345211738Srpaulo PROC_UNLOCK(p); 2346211738Srpaulo#endif 2347179193Sjb } 2348211738Srpaulo#endif /* notyet */ 2349179193Sjb 2350179193Sjb ret = fasttrap_add_probe(probe); 2351179193Sjberr: 2352179193Sjb kmem_free(probe, size); 2353179193Sjb 2354179193Sjb return (ret); 2355179193Sjb 2356179193Sjb } else if (cmd == FASTTRAPIOC_GETINSTR) { 2357179193Sjb fasttrap_instr_query_t instr; 2358179193Sjb fasttrap_tracepoint_t *tp; 2359179193Sjb uint_t index; 2360211738Srpaulo#if defined(sun) 2361179193Sjb int ret; 2362211738Srpaulo#endif 2363179193Sjb 2364211738Srpaulo#if defined(sun) 2365179193Sjb if (copyin((void *)arg, &instr, sizeof (instr)) != 0) 2366179193Sjb return (EFAULT); 2367211738Srpaulo#endif 2368179193Sjb 2369211738Srpaulo#ifdef notyet 2370179193Sjb if (!PRIV_POLICY_CHOICE(cr, PRIV_ALL, B_FALSE)) { 2371179193Sjb proc_t *p; 2372179193Sjb pid_t pid = instr.ftiq_pid; 2373179193Sjb 2374211738Srpaulo#if defined(sun) 2375179193Sjb mutex_enter(&pidlock); 2376211738Srpaulo#endif 2377179193Sjb /* 2378179193Sjb * Report an error if the process doesn't exist 2379179193Sjb * or is actively being birthed. 2380179193Sjb */ 2381211738Srpaulo p = pfind(pid); 2382211738Srpaulo if (p) 2383211738Srpaulo fill_kinfo_proc(p, &kp); 2384211738Srpaulo if (p == NULL || kp.ki_stat == SIDL) { 2385211738Srpaulo#if defined(sun) 2386179193Sjb mutex_exit(&pidlock); 2387211738Srpaulo#endif 2388179193Sjb return (ESRCH); 2389179193Sjb } 2390211738Srpaulo#if defined(sun) 2391179193Sjb mutex_enter(&p->p_lock); 2392179193Sjb mutex_exit(&pidlock); 2393211738Srpaulo#else 2394211738Srpaulo PROC_LOCK_ASSERT(p, MA_OWNED); 2395211738Srpaulo#endif 2396179193Sjb 2397211738Srpaulo#ifdef notyet 2398179193Sjb if ((ret = priv_proc_cred_perm(cr, p, NULL, 2399179193Sjb VREAD)) != 0) { 2400211738Srpaulo#if defined(sun) 2401179193Sjb mutex_exit(&p->p_lock); 2402211738Srpaulo#else 2403211738Srpaulo PROC_UNLOCK(p); 2404211738Srpaulo#endif 2405179193Sjb return (ret); 2406179193Sjb } 2407211738Srpaulo#endif /* notyet */ 2408179193Sjb 2409211738Srpaulo#if defined(sun) 2410179193Sjb mutex_exit(&p->p_lock); 2411211738Srpaulo#else 2412211738Srpaulo PROC_UNLOCK(p); 2413211738Srpaulo#endif 2414179193Sjb } 2415211738Srpaulo#endif /* notyet */ 2416179193Sjb 2417179193Sjb index = FASTTRAP_TPOINTS_INDEX(instr.ftiq_pid, instr.ftiq_pc); 2418179193Sjb 2419179193Sjb mutex_enter(&fasttrap_tpoints.fth_table[index].ftb_mtx); 2420179193Sjb tp = fasttrap_tpoints.fth_table[index].ftb_data; 2421179193Sjb while (tp != NULL) { 2422179193Sjb if (instr.ftiq_pid == tp->ftt_pid && 2423179193Sjb instr.ftiq_pc == tp->ftt_pc && 2424179193Sjb tp->ftt_proc->ftpc_acount != 0) 2425179193Sjb break; 2426179193Sjb 2427179193Sjb tp = tp->ftt_next; 2428179193Sjb } 2429179193Sjb 2430179193Sjb if (tp == NULL) { 2431179193Sjb mutex_exit(&fasttrap_tpoints.fth_table[index].ftb_mtx); 2432179193Sjb return (ENOENT); 2433179193Sjb } 2434179193Sjb 2435179193Sjb bcopy(&tp->ftt_instr, &instr.ftiq_instr, 2436179193Sjb sizeof (instr.ftiq_instr)); 2437179193Sjb mutex_exit(&fasttrap_tpoints.fth_table[index].ftb_mtx); 2438179193Sjb 2439179193Sjb if (copyout(&instr, (void *)arg, sizeof (instr)) != 0) 2440179193Sjb return (EFAULT); 2441179193Sjb 2442179193Sjb return (0); 2443179193Sjb } 2444179193Sjb 2445179193Sjb return (EINVAL); 2446179193Sjb} 2447179193Sjb 2448179193Sjbstatic int 2449211738Srpaulofasttrap_load(void) 2450179193Sjb{ 2451179193Sjb ulong_t nent; 2452250953Smarkj int i, ret; 2453179193Sjb 2454211738Srpaulo /* Create the /dev/dtrace/fasttrap entry. */ 2455211738Srpaulo fasttrap_cdev = make_dev(&fasttrap_cdevsw, 0, UID_ROOT, GID_WHEEL, 0600, 2456211738Srpaulo "dtrace/fasttrap"); 2457179193Sjb 2458211738Srpaulo mtx_init(&fasttrap_cleanup_mtx, "fasttrap clean", "dtrace", MTX_DEF); 2459211738Srpaulo mutex_init(&fasttrap_count_mtx, "fasttrap count mtx", MUTEX_DEFAULT, 2460211738Srpaulo NULL); 2461179193Sjb 2462211738Srpaulo#if defined(sun) 2463179193Sjb fasttrap_max = ddi_getprop(DDI_DEV_T_ANY, devi, DDI_PROP_DONTPASS, 2464179193Sjb "fasttrap-max-probes", FASTTRAP_MAX_DEFAULT); 2465211738Srpaulo#else 2466211738Srpaulo fasttrap_max = FASTTRAP_MAX_DEFAULT; 2467211738Srpaulo#endif 2468179193Sjb fasttrap_total = 0; 2469179193Sjb 2470179193Sjb /* 2471179193Sjb * Conjure up the tracepoints hashtable... 2472179193Sjb */ 2473211738Srpaulo#if defined(sun) 2474179193Sjb nent = ddi_getprop(DDI_DEV_T_ANY, devi, DDI_PROP_DONTPASS, 2475179193Sjb "fasttrap-hash-size", FASTTRAP_TPOINTS_DEFAULT_SIZE); 2476211738Srpaulo#else 2477211738Srpaulo nent = FASTTRAP_TPOINTS_DEFAULT_SIZE; 2478211738Srpaulo#endif 2479179193Sjb 2480179193Sjb if (nent == 0 || nent > 0x1000000) 2481179193Sjb nent = FASTTRAP_TPOINTS_DEFAULT_SIZE; 2482179193Sjb 2483179193Sjb if ((nent & (nent - 1)) == 0) 2484179193Sjb fasttrap_tpoints.fth_nent = nent; 2485179193Sjb else 2486179193Sjb fasttrap_tpoints.fth_nent = 1 << fasttrap_highbit(nent); 2487179193Sjb ASSERT(fasttrap_tpoints.fth_nent > 0); 2488179193Sjb fasttrap_tpoints.fth_mask = fasttrap_tpoints.fth_nent - 1; 2489179193Sjb fasttrap_tpoints.fth_table = kmem_zalloc(fasttrap_tpoints.fth_nent * 2490179193Sjb sizeof (fasttrap_bucket_t), KM_SLEEP); 2491211738Srpaulo#if !defined(sun) 2492211738Srpaulo for (i = 0; i < fasttrap_tpoints.fth_nent; i++) 2493211738Srpaulo mutex_init(&fasttrap_tpoints.fth_table[i].ftb_mtx, 2494211738Srpaulo "tracepoints bucket mtx", MUTEX_DEFAULT, NULL); 2495211738Srpaulo#endif 2496179193Sjb 2497179193Sjb /* 2498179193Sjb * ... and the providers hash table... 2499179193Sjb */ 2500179193Sjb nent = FASTTRAP_PROVIDERS_DEFAULT_SIZE; 2501179193Sjb if ((nent & (nent - 1)) == 0) 2502179193Sjb fasttrap_provs.fth_nent = nent; 2503179193Sjb else 2504179193Sjb fasttrap_provs.fth_nent = 1 << fasttrap_highbit(nent); 2505179193Sjb ASSERT(fasttrap_provs.fth_nent > 0); 2506179193Sjb fasttrap_provs.fth_mask = fasttrap_provs.fth_nent - 1; 2507179193Sjb fasttrap_provs.fth_table = kmem_zalloc(fasttrap_provs.fth_nent * 2508179193Sjb sizeof (fasttrap_bucket_t), KM_SLEEP); 2509211738Srpaulo#if !defined(sun) 2510211738Srpaulo for (i = 0; i < fasttrap_provs.fth_nent; i++) 2511211738Srpaulo mutex_init(&fasttrap_provs.fth_table[i].ftb_mtx, 2512211738Srpaulo "providers bucket mtx", MUTEX_DEFAULT, NULL); 2513211738Srpaulo#endif 2514179193Sjb 2515258311Sasomers ret = kproc_create(fasttrap_pid_cleanup_cb, NULL, 2516258311Sasomers &fasttrap_cleanup_proc, 0, 0, "ftcleanup"); 2517258311Sasomers if (ret != 0) { 2518258311Sasomers destroy_dev(fasttrap_cdev); 2519258311Sasomers#if !defined(sun) 2520258311Sasomers for (i = 0; i < fasttrap_provs.fth_nent; i++) 2521258311Sasomers mutex_destroy(&fasttrap_provs.fth_table[i].ftb_mtx); 2522258311Sasomers for (i = 0; i < fasttrap_tpoints.fth_nent; i++) 2523258311Sasomers mutex_destroy(&fasttrap_tpoints.fth_table[i].ftb_mtx); 2524258311Sasomers#endif 2525258311Sasomers kmem_free(fasttrap_provs.fth_table, fasttrap_provs.fth_nent * 2526258311Sasomers sizeof (fasttrap_bucket_t)); 2527258311Sasomers mtx_destroy(&fasttrap_cleanup_mtx); 2528258311Sasomers mutex_destroy(&fasttrap_count_mtx); 2529258311Sasomers return (ret); 2530258311Sasomers } 2531258311Sasomers 2532258311Sasomers 2533179193Sjb /* 2534179193Sjb * ... and the procs hash table. 2535179193Sjb */ 2536179193Sjb nent = FASTTRAP_PROCS_DEFAULT_SIZE; 2537179193Sjb if ((nent & (nent - 1)) == 0) 2538179193Sjb fasttrap_procs.fth_nent = nent; 2539179193Sjb else 2540179193Sjb fasttrap_procs.fth_nent = 1 << fasttrap_highbit(nent); 2541179193Sjb ASSERT(fasttrap_procs.fth_nent > 0); 2542179193Sjb fasttrap_procs.fth_mask = fasttrap_procs.fth_nent - 1; 2543179193Sjb fasttrap_procs.fth_table = kmem_zalloc(fasttrap_procs.fth_nent * 2544179193Sjb sizeof (fasttrap_bucket_t), KM_SLEEP); 2545211738Srpaulo#if !defined(sun) 2546211738Srpaulo for (i = 0; i < fasttrap_procs.fth_nent; i++) 2547211738Srpaulo mutex_init(&fasttrap_procs.fth_table[i].ftb_mtx, 2548211738Srpaulo "processes bucket mtx", MUTEX_DEFAULT, NULL); 2549211925Srpaulo 2550211925Srpaulo CPU_FOREACH(i) { 2551211925Srpaulo mutex_init(&fasttrap_cpuc_pid_lock[i], "fasttrap barrier", 2552211925Srpaulo MUTEX_DEFAULT, NULL); 2553211925Srpaulo } 2554264434Smarkj 2555264434Smarkj /* 2556264434Smarkj * This event handler must run before kdtrace_thread_dtor() since it 2557264434Smarkj * accesses the thread's struct kdtrace_thread. 2558264434Smarkj */ 2559264434Smarkj fasttrap_thread_dtor_tag = EVENTHANDLER_REGISTER(thread_dtor, 2560264434Smarkj fasttrap_thread_dtor, NULL, EVENTHANDLER_PRI_FIRST); 2561211738Srpaulo#endif 2562179193Sjb 2563253079Savg /* 2564253079Savg * Install our hooks into fork(2), exec(2), and exit(2). 2565253079Savg */ 2566253079Savg dtrace_fasttrap_fork = &fasttrap_fork; 2567253079Savg dtrace_fasttrap_exit = &fasttrap_exec_exit; 2568253079Savg dtrace_fasttrap_exec = &fasttrap_exec_exit; 2569253079Savg 2570179193Sjb (void) dtrace_meta_register("fasttrap", &fasttrap_mops, NULL, 2571179193Sjb &fasttrap_meta_id); 2572179193Sjb 2573211738Srpaulo return (0); 2574179193Sjb} 2575179193Sjb 2576179193Sjbstatic int 2577211738Srpaulofasttrap_unload(void) 2578179193Sjb{ 2579179193Sjb int i, fail = 0; 2580179193Sjb 2581179193Sjb /* 2582179193Sjb * Unregister the meta-provider to make sure no new fasttrap- 2583179193Sjb * managed providers come along while we're trying to close up 2584179193Sjb * shop. If we fail to detach, we'll need to re-register as a 2585179193Sjb * meta-provider. We can fail to unregister as a meta-provider 2586179193Sjb * if providers we manage still exist. 2587179193Sjb */ 2588179193Sjb if (fasttrap_meta_id != DTRACE_METAPROVNONE && 2589179193Sjb dtrace_meta_unregister(fasttrap_meta_id) != 0) 2590211738Srpaulo return (-1); 2591179193Sjb 2592179193Sjb /* 2593179193Sjb * Iterate over all of our providers. If there's still a process 2594179193Sjb * that corresponds to that pid, fail to detach. 2595179193Sjb */ 2596179193Sjb for (i = 0; i < fasttrap_provs.fth_nent; i++) { 2597179193Sjb fasttrap_provider_t **fpp, *fp; 2598179193Sjb fasttrap_bucket_t *bucket = &fasttrap_provs.fth_table[i]; 2599179193Sjb 2600179193Sjb mutex_enter(&bucket->ftb_mtx); 2601179193Sjb fpp = (fasttrap_provider_t **)&bucket->ftb_data; 2602179193Sjb while ((fp = *fpp) != NULL) { 2603179193Sjb /* 2604179193Sjb * Acquire and release the lock as a simple way of 2605179193Sjb * waiting for any other consumer to finish with 2606179193Sjb * this provider. A thread must first acquire the 2607179193Sjb * bucket lock so there's no chance of another thread 2608179193Sjb * blocking on the provider's lock. 2609179193Sjb */ 2610179193Sjb mutex_enter(&fp->ftp_mtx); 2611179193Sjb mutex_exit(&fp->ftp_mtx); 2612179193Sjb 2613179193Sjb if (dtrace_unregister(fp->ftp_provid) != 0) { 2614179193Sjb fail = 1; 2615179193Sjb fpp = &fp->ftp_next; 2616179193Sjb } else { 2617179193Sjb *fpp = fp->ftp_next; 2618179193Sjb fasttrap_provider_free(fp); 2619179193Sjb } 2620179193Sjb } 2621179193Sjb 2622179193Sjb mutex_exit(&bucket->ftb_mtx); 2623179193Sjb } 2624179193Sjb 2625179193Sjb if (fail) { 2626179193Sjb (void) dtrace_meta_register("fasttrap", &fasttrap_mops, NULL, 2627179193Sjb &fasttrap_meta_id); 2628179193Sjb 2629211738Srpaulo return (-1); 2630179193Sjb } 2631179193Sjb 2632258311Sasomers /* 2633258311Sasomers * Stop new processes from entering these hooks now, before the 2634258311Sasomers * fasttrap_cleanup thread runs. That way all processes will hopefully 2635258311Sasomers * be out of these hooks before we free fasttrap_provs.fth_table 2636258311Sasomers */ 2637258311Sasomers ASSERT(dtrace_fasttrap_fork == &fasttrap_fork); 2638258311Sasomers dtrace_fasttrap_fork = NULL; 2639258311Sasomers 2640258311Sasomers ASSERT(dtrace_fasttrap_exec == &fasttrap_exec_exit); 2641258311Sasomers dtrace_fasttrap_exec = NULL; 2642258311Sasomers 2643258311Sasomers ASSERT(dtrace_fasttrap_exit == &fasttrap_exec_exit); 2644258311Sasomers dtrace_fasttrap_exit = NULL; 2645258311Sasomers 2646250953Smarkj mtx_lock(&fasttrap_cleanup_mtx); 2647250953Smarkj fasttrap_cleanup_drain = 1; 2648250953Smarkj /* Wait for the cleanup thread to finish up and signal us. */ 2649250953Smarkj wakeup(&fasttrap_cleanup_cv); 2650250953Smarkj mtx_sleep(&fasttrap_cleanup_drain, &fasttrap_cleanup_mtx, 0, "ftcld", 2651250953Smarkj 0); 2652250953Smarkj fasttrap_cleanup_proc = NULL; 2653252493Smarkj mtx_destroy(&fasttrap_cleanup_mtx); 2654250953Smarkj 2655179193Sjb#ifdef DEBUG 2656179193Sjb mutex_enter(&fasttrap_count_mtx); 2657179193Sjb ASSERT(fasttrap_pid_count == 0); 2658179193Sjb mutex_exit(&fasttrap_count_mtx); 2659179193Sjb#endif 2660179193Sjb 2661258311Sasomers#if !defined(sun) 2662264434Smarkj EVENTHANDLER_DEREGISTER(thread_dtor, fasttrap_thread_dtor_tag); 2663264434Smarkj 2664258311Sasomers for (i = 0; i < fasttrap_tpoints.fth_nent; i++) 2665258311Sasomers mutex_destroy(&fasttrap_tpoints.fth_table[i].ftb_mtx); 2666258311Sasomers for (i = 0; i < fasttrap_provs.fth_nent; i++) 2667258311Sasomers mutex_destroy(&fasttrap_provs.fth_table[i].ftb_mtx); 2668258311Sasomers for (i = 0; i < fasttrap_procs.fth_nent; i++) 2669258311Sasomers mutex_destroy(&fasttrap_procs.fth_table[i].ftb_mtx); 2670258311Sasomers#endif 2671179193Sjb kmem_free(fasttrap_tpoints.fth_table, 2672179193Sjb fasttrap_tpoints.fth_nent * sizeof (fasttrap_bucket_t)); 2673179193Sjb fasttrap_tpoints.fth_nent = 0; 2674179193Sjb 2675179193Sjb kmem_free(fasttrap_provs.fth_table, 2676179193Sjb fasttrap_provs.fth_nent * sizeof (fasttrap_bucket_t)); 2677179193Sjb fasttrap_provs.fth_nent = 0; 2678179193Sjb 2679179193Sjb kmem_free(fasttrap_procs.fth_table, 2680179193Sjb fasttrap_procs.fth_nent * sizeof (fasttrap_bucket_t)); 2681179193Sjb fasttrap_procs.fth_nent = 0; 2682179193Sjb 2683211738Srpaulo#if !defined(sun) 2684211738Srpaulo destroy_dev(fasttrap_cdev); 2685211738Srpaulo mutex_destroy(&fasttrap_count_mtx); 2686211925Srpaulo CPU_FOREACH(i) { 2687211925Srpaulo mutex_destroy(&fasttrap_cpuc_pid_lock[i]); 2688211925Srpaulo } 2689211738Srpaulo#endif 2690179193Sjb 2691211738Srpaulo return (0); 2692179193Sjb} 2693179193Sjb 2694211738Srpaulo/* ARGSUSED */ 2695211738Srpaulostatic int 2696211738Srpaulofasttrap_modevent(module_t mod __unused, int type, void *data __unused) 2697211738Srpaulo{ 2698211738Srpaulo int error = 0; 2699179193Sjb 2700211738Srpaulo switch (type) { 2701211738Srpaulo case MOD_LOAD: 2702211738Srpaulo break; 2703179193Sjb 2704211738Srpaulo case MOD_UNLOAD: 2705211738Srpaulo break; 2706179193Sjb 2707211738Srpaulo case MOD_SHUTDOWN: 2708211738Srpaulo break; 2709179193Sjb 2710211738Srpaulo default: 2711211738Srpaulo error = EOPNOTSUPP; 2712211738Srpaulo break; 2713211738Srpaulo } 2714211738Srpaulo return (error); 2715179193Sjb} 2716179193Sjb 2717211738SrpauloSYSINIT(fasttrap_load, SI_SUB_DTRACE_PROVIDER, SI_ORDER_ANY, fasttrap_load, 2718211738Srpaulo NULL); 2719211738SrpauloSYSUNINIT(fasttrap_unload, SI_SUB_DTRACE_PROVIDER, SI_ORDER_ANY, 2720211738Srpaulo fasttrap_unload, NULL); 2721211738Srpaulo 2722211738SrpauloDEV_MODULE(fasttrap, fasttrap_modevent, NULL); 2723211738SrpauloMODULE_VERSION(fasttrap, 1); 2724211738SrpauloMODULE_DEPEND(fasttrap, dtrace, 1, 1, 1); 2725211738SrpauloMODULE_DEPEND(fasttrap, opensolaris, 1, 1, 1); 2726