1*0Sstevel@tonic-gate /* 2*0Sstevel@tonic-gate * CDDL HEADER START 3*0Sstevel@tonic-gate * 4*0Sstevel@tonic-gate * The contents of this file are subject to the terms of the 5*0Sstevel@tonic-gate * Common Development and Distribution License, Version 1.0 only 6*0Sstevel@tonic-gate * (the "License"). You may not use this file except in compliance 7*0Sstevel@tonic-gate * with the License. 8*0Sstevel@tonic-gate * 9*0Sstevel@tonic-gate * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10*0Sstevel@tonic-gate * or http://www.opensolaris.org/os/licensing. 11*0Sstevel@tonic-gate * See the License for the specific language governing permissions 12*0Sstevel@tonic-gate * and limitations under the License. 13*0Sstevel@tonic-gate * 14*0Sstevel@tonic-gate * When distributing Covered Code, include this CDDL HEADER in each 15*0Sstevel@tonic-gate * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16*0Sstevel@tonic-gate * If applicable, add the following below this CDDL HEADER, with the 17*0Sstevel@tonic-gate * fields enclosed by brackets "[]" replaced with your own identifying 18*0Sstevel@tonic-gate * information: Portions Copyright [yyyy] [name of copyright owner] 19*0Sstevel@tonic-gate * 20*0Sstevel@tonic-gate * CDDL HEADER END 21*0Sstevel@tonic-gate */ 22*0Sstevel@tonic-gate /* 23*0Sstevel@tonic-gate * Copyright 2004 Sun Microsystems, Inc. All rights reserved. 24*0Sstevel@tonic-gate * Use is subject to license terms. 25*0Sstevel@tonic-gate */ 26*0Sstevel@tonic-gate 27*0Sstevel@tonic-gate #pragma ident "%Z%%M% %I% %E% SMI" 28*0Sstevel@tonic-gate 29*0Sstevel@tonic-gate #include <sys/param.h> 30*0Sstevel@tonic-gate #include <sys/t_lock.h> 31*0Sstevel@tonic-gate #include <sys/types.h> 32*0Sstevel@tonic-gate #include <sys/time.h> 33*0Sstevel@tonic-gate #include <sys/sysmacros.h> 34*0Sstevel@tonic-gate #include <sys/systm.h> 35*0Sstevel@tonic-gate #include <sys/cpuvar.h> 36*0Sstevel@tonic-gate #include <sys/user.h> 37*0Sstevel@tonic-gate #include <sys/proc.h> 38*0Sstevel@tonic-gate #include <sys/callb.h> 39*0Sstevel@tonic-gate #include <sys/kmem.h> 40*0Sstevel@tonic-gate #include <sys/cmn_err.h> 41*0Sstevel@tonic-gate #include <sys/swap.h> 42*0Sstevel@tonic-gate #include <sys/vmsystm.h> 43*0Sstevel@tonic-gate #include <sys/class.h> 44*0Sstevel@tonic-gate #include <sys/debug.h> 45*0Sstevel@tonic-gate #include <sys/thread.h> 46*0Sstevel@tonic-gate #include <sys/kobj.h> 47*0Sstevel@tonic-gate #include <sys/ddi.h> /* for delay() */ 48*0Sstevel@tonic-gate #include <sys/taskq.h> /* For TASKQ_NAMELEN */ 49*0Sstevel@tonic-gate 50*0Sstevel@tonic-gate #define CB_MAXNAME TASKQ_NAMELEN 51*0Sstevel@tonic-gate 52*0Sstevel@tonic-gate /* 53*0Sstevel@tonic-gate * The callb mechanism provides generic event scheduling/echoing. 54*0Sstevel@tonic-gate * A callb function is registered and called on behalf of the event. 55*0Sstevel@tonic-gate */ 56*0Sstevel@tonic-gate typedef struct callb { 57*0Sstevel@tonic-gate struct callb *c_next; /* next in class or on freelist */ 58*0Sstevel@tonic-gate kthread_id_t c_thread; /* ptr to caller's thread struct */ 59*0Sstevel@tonic-gate char c_flag; /* info about the callb state */ 60*0Sstevel@tonic-gate uchar_t c_class; /* this callb's class */ 61*0Sstevel@tonic-gate kcondvar_t c_done_cv; /* signal callb completion */ 62*0Sstevel@tonic-gate boolean_t (*c_func)(); /* cb function: returns true if ok */ 63*0Sstevel@tonic-gate void *c_arg; /* arg to c_func */ 64*0Sstevel@tonic-gate char c_name[CB_MAXNAME+1]; /* debug:max func name length */ 65*0Sstevel@tonic-gate } callb_t; 66*0Sstevel@tonic-gate 67*0Sstevel@tonic-gate /* 68*0Sstevel@tonic-gate * callb c_flag bitmap definitions 69*0Sstevel@tonic-gate */ 70*0Sstevel@tonic-gate #define CALLB_FREE 0x0 71*0Sstevel@tonic-gate #define CALLB_TAKEN 0x1 72*0Sstevel@tonic-gate #define CALLB_EXECUTING 0x2 73*0Sstevel@tonic-gate 74*0Sstevel@tonic-gate /* 75*0Sstevel@tonic-gate * Basic structure for a callb table. 76*0Sstevel@tonic-gate * All callbs are organized into different class groups described 77*0Sstevel@tonic-gate * by ct_class array. 78*0Sstevel@tonic-gate * The callbs within a class are single-linked and normally run by a 79*0Sstevel@tonic-gate * serial execution. 80*0Sstevel@tonic-gate */ 81*0Sstevel@tonic-gate typedef struct callb_table { 82*0Sstevel@tonic-gate kmutex_t ct_lock; /* protect all callb states */ 83*0Sstevel@tonic-gate callb_t *ct_freelist; /* free callb structures */ 84*0Sstevel@tonic-gate int ct_busy; /* != 0 prevents additions */ 85*0Sstevel@tonic-gate kcondvar_t ct_busy_cv; /* to wait for not busy */ 86*0Sstevel@tonic-gate int ct_ncallb; /* num of callbs allocated */ 87*0Sstevel@tonic-gate callb_t *ct_first_cb[NCBCLASS]; /* ptr to 1st callb in a class */ 88*0Sstevel@tonic-gate } callb_table_t; 89*0Sstevel@tonic-gate 90*0Sstevel@tonic-gate int callb_timeout_sec = CPR_KTHREAD_TIMEOUT_SEC; 91*0Sstevel@tonic-gate 92*0Sstevel@tonic-gate static callb_id_t callb_add_common(boolean_t (*)(void *, int), 93*0Sstevel@tonic-gate void *, int, char *, kthread_id_t); 94*0Sstevel@tonic-gate 95*0Sstevel@tonic-gate static callb_table_t callb_table; /* system level callback table */ 96*0Sstevel@tonic-gate static callb_table_t *ct = &callb_table; 97*0Sstevel@tonic-gate static kmutex_t callb_safe_mutex; 98*0Sstevel@tonic-gate callb_cpr_t callb_cprinfo_safe = { 99*0Sstevel@tonic-gate &callb_safe_mutex, CALLB_CPR_ALWAYS_SAFE, 0, 0, 0 }; 100*0Sstevel@tonic-gate 101*0Sstevel@tonic-gate /* 102*0Sstevel@tonic-gate * Init all callb tables in the system. 103*0Sstevel@tonic-gate */ 104*0Sstevel@tonic-gate void 105*0Sstevel@tonic-gate callb_init() 106*0Sstevel@tonic-gate { 107*0Sstevel@tonic-gate callb_table.ct_busy = 0; /* mark table open for additions */ 108*0Sstevel@tonic-gate mutex_init(&callb_safe_mutex, NULL, MUTEX_DEFAULT, NULL); 109*0Sstevel@tonic-gate mutex_init(&callb_table.ct_lock, NULL, MUTEX_DEFAULT, NULL); 110*0Sstevel@tonic-gate } 111*0Sstevel@tonic-gate 112*0Sstevel@tonic-gate /* 113*0Sstevel@tonic-gate * callout_add() is called to register func() be called later. 114*0Sstevel@tonic-gate */ 115*0Sstevel@tonic-gate static callb_id_t 116*0Sstevel@tonic-gate callb_add_common(boolean_t (*func)(void *arg, int code), 117*0Sstevel@tonic-gate void *arg, int class, char *name, kthread_id_t t) 118*0Sstevel@tonic-gate { 119*0Sstevel@tonic-gate callb_t *cp; 120*0Sstevel@tonic-gate 121*0Sstevel@tonic-gate ASSERT(class < NCBCLASS); 122*0Sstevel@tonic-gate 123*0Sstevel@tonic-gate mutex_enter(&ct->ct_lock); 124*0Sstevel@tonic-gate while (ct->ct_busy) 125*0Sstevel@tonic-gate cv_wait(&ct->ct_busy_cv, &ct->ct_lock); 126*0Sstevel@tonic-gate if ((cp = ct->ct_freelist) == NULL) { 127*0Sstevel@tonic-gate ct->ct_ncallb++; 128*0Sstevel@tonic-gate cp = (callb_t *)kmem_zalloc(sizeof (callb_t), KM_SLEEP); 129*0Sstevel@tonic-gate } 130*0Sstevel@tonic-gate ct->ct_freelist = cp->c_next; 131*0Sstevel@tonic-gate cp->c_thread = t; 132*0Sstevel@tonic-gate cp->c_func = func; 133*0Sstevel@tonic-gate cp->c_arg = arg; 134*0Sstevel@tonic-gate cp->c_class = (uchar_t)class; 135*0Sstevel@tonic-gate cp->c_flag |= CALLB_TAKEN; 136*0Sstevel@tonic-gate #ifdef DEBUG 137*0Sstevel@tonic-gate if (strlen(name) > CB_MAXNAME) 138*0Sstevel@tonic-gate cmn_err(CE_WARN, "callb_add: name of callback function '%s' " 139*0Sstevel@tonic-gate "too long -- truncated to %d chars", 140*0Sstevel@tonic-gate name, CB_MAXNAME); 141*0Sstevel@tonic-gate #endif 142*0Sstevel@tonic-gate (void) strncpy(cp->c_name, name, CB_MAXNAME); 143*0Sstevel@tonic-gate cp->c_name[CB_MAXNAME] = '\0'; 144*0Sstevel@tonic-gate 145*0Sstevel@tonic-gate /* 146*0Sstevel@tonic-gate * Insert the new callb at the head of its class list. 147*0Sstevel@tonic-gate */ 148*0Sstevel@tonic-gate cp->c_next = ct->ct_first_cb[class]; 149*0Sstevel@tonic-gate ct->ct_first_cb[class] = cp; 150*0Sstevel@tonic-gate 151*0Sstevel@tonic-gate mutex_exit(&ct->ct_lock); 152*0Sstevel@tonic-gate return ((callb_id_t)cp); 153*0Sstevel@tonic-gate } 154*0Sstevel@tonic-gate 155*0Sstevel@tonic-gate /* 156*0Sstevel@tonic-gate * The default function to add an entry to the callback table. Since 157*0Sstevel@tonic-gate * it uses curthread as the thread identifier to store in the table, 158*0Sstevel@tonic-gate * it should be used for the normal case of a thread which is calling 159*0Sstevel@tonic-gate * to add ITSELF to the table. 160*0Sstevel@tonic-gate */ 161*0Sstevel@tonic-gate callb_id_t 162*0Sstevel@tonic-gate callb_add(boolean_t (*func)(void *arg, int code), 163*0Sstevel@tonic-gate void *arg, int class, char *name) 164*0Sstevel@tonic-gate { 165*0Sstevel@tonic-gate return (callb_add_common(func, arg, class, name, curthread)); 166*0Sstevel@tonic-gate } 167*0Sstevel@tonic-gate 168*0Sstevel@tonic-gate /* 169*0Sstevel@tonic-gate * A special version of callb_add() above for use by threads which 170*0Sstevel@tonic-gate * might be adding an entry to the table on behalf of some other 171*0Sstevel@tonic-gate * thread (for example, one which is constructed but not yet running). 172*0Sstevel@tonic-gate * In this version the thread id is an argument. 173*0Sstevel@tonic-gate */ 174*0Sstevel@tonic-gate callb_id_t 175*0Sstevel@tonic-gate callb_add_thread(boolean_t (*func)(void *arg, int code), 176*0Sstevel@tonic-gate void *arg, int class, char *name, kthread_id_t t) 177*0Sstevel@tonic-gate { 178*0Sstevel@tonic-gate return (callb_add_common(func, arg, class, name, t)); 179*0Sstevel@tonic-gate } 180*0Sstevel@tonic-gate 181*0Sstevel@tonic-gate /* 182*0Sstevel@tonic-gate * callout_delete() is called to remove an entry identified by id 183*0Sstevel@tonic-gate * that was originally placed there by a call to callout_add(). 184*0Sstevel@tonic-gate * return -1 if fail to delete a callb entry otherwise return 0. 185*0Sstevel@tonic-gate */ 186*0Sstevel@tonic-gate int 187*0Sstevel@tonic-gate callb_delete(callb_id_t id) 188*0Sstevel@tonic-gate { 189*0Sstevel@tonic-gate callb_t **pp; 190*0Sstevel@tonic-gate callb_t *me = (callb_t *)id; 191*0Sstevel@tonic-gate 192*0Sstevel@tonic-gate mutex_enter(&ct->ct_lock); 193*0Sstevel@tonic-gate 194*0Sstevel@tonic-gate for (;;) { 195*0Sstevel@tonic-gate pp = &ct->ct_first_cb[me->c_class]; 196*0Sstevel@tonic-gate while (*pp != NULL && *pp != me) 197*0Sstevel@tonic-gate pp = &(*pp)->c_next; 198*0Sstevel@tonic-gate 199*0Sstevel@tonic-gate #ifdef DEBUG 200*0Sstevel@tonic-gate if (*pp != me) { 201*0Sstevel@tonic-gate cmn_err(CE_WARN, "callb delete bogus entry 0x%p", 202*0Sstevel@tonic-gate (void *)me); 203*0Sstevel@tonic-gate mutex_exit(&ct->ct_lock); 204*0Sstevel@tonic-gate return (-1); 205*0Sstevel@tonic-gate } 206*0Sstevel@tonic-gate #endif /* DEBUG */ 207*0Sstevel@tonic-gate 208*0Sstevel@tonic-gate /* 209*0Sstevel@tonic-gate * It is not allowed to delete a callb in the middle of 210*0Sstevel@tonic-gate * executing otherwise, the callb_execute() will be confused. 211*0Sstevel@tonic-gate */ 212*0Sstevel@tonic-gate if (!(me->c_flag & CALLB_EXECUTING)) 213*0Sstevel@tonic-gate break; 214*0Sstevel@tonic-gate 215*0Sstevel@tonic-gate cv_wait(&me->c_done_cv, &ct->ct_lock); 216*0Sstevel@tonic-gate } 217*0Sstevel@tonic-gate /* relink the class list */ 218*0Sstevel@tonic-gate *pp = me->c_next; 219*0Sstevel@tonic-gate 220*0Sstevel@tonic-gate /* clean up myself and return the free callb to the head of freelist */ 221*0Sstevel@tonic-gate me->c_flag = CALLB_FREE; 222*0Sstevel@tonic-gate me->c_next = ct->ct_freelist; 223*0Sstevel@tonic-gate ct->ct_freelist = me; 224*0Sstevel@tonic-gate 225*0Sstevel@tonic-gate mutex_exit(&ct->ct_lock); 226*0Sstevel@tonic-gate return (0); 227*0Sstevel@tonic-gate } 228*0Sstevel@tonic-gate 229*0Sstevel@tonic-gate /* 230*0Sstevel@tonic-gate * class: indicates to execute all callbs in the same class; 231*0Sstevel@tonic-gate * code: optional argument for the callb functions. 232*0Sstevel@tonic-gate * return: = 0: success 233*0Sstevel@tonic-gate * != 0: ptr to string supplied when callback was registered 234*0Sstevel@tonic-gate */ 235*0Sstevel@tonic-gate void * 236*0Sstevel@tonic-gate callb_execute_class(int class, int code) 237*0Sstevel@tonic-gate { 238*0Sstevel@tonic-gate callb_t *cp; 239*0Sstevel@tonic-gate void *ret = NULL; 240*0Sstevel@tonic-gate 241*0Sstevel@tonic-gate ASSERT(class < NCBCLASS); 242*0Sstevel@tonic-gate 243*0Sstevel@tonic-gate mutex_enter(&ct->ct_lock); 244*0Sstevel@tonic-gate 245*0Sstevel@tonic-gate for (cp = ct->ct_first_cb[class]; 246*0Sstevel@tonic-gate cp != NULL && ret == 0; cp = cp->c_next) { 247*0Sstevel@tonic-gate while (cp->c_flag & CALLB_EXECUTING) 248*0Sstevel@tonic-gate cv_wait(&cp->c_done_cv, &ct->ct_lock); 249*0Sstevel@tonic-gate /* 250*0Sstevel@tonic-gate * cont if the callb is deleted while we're sleeping 251*0Sstevel@tonic-gate */ 252*0Sstevel@tonic-gate if (cp->c_flag == CALLB_FREE) 253*0Sstevel@tonic-gate continue; 254*0Sstevel@tonic-gate cp->c_flag |= CALLB_EXECUTING; 255*0Sstevel@tonic-gate 256*0Sstevel@tonic-gate #ifdef CALLB_DEBUG 257*0Sstevel@tonic-gate printf("callb_execute: name=%s func=%p arg=%p\n", 258*0Sstevel@tonic-gate cp->c_name, (void *)cp->c_func, (void *)cp->c_arg); 259*0Sstevel@tonic-gate #endif /* CALLB_DEBUG */ 260*0Sstevel@tonic-gate 261*0Sstevel@tonic-gate mutex_exit(&ct->ct_lock); 262*0Sstevel@tonic-gate /* If callback function fails, pass back client's name */ 263*0Sstevel@tonic-gate if (!(*cp->c_func)(cp->c_arg, code)) 264*0Sstevel@tonic-gate ret = cp->c_name; 265*0Sstevel@tonic-gate mutex_enter(&ct->ct_lock); 266*0Sstevel@tonic-gate 267*0Sstevel@tonic-gate cp->c_flag &= ~CALLB_EXECUTING; 268*0Sstevel@tonic-gate cv_broadcast(&cp->c_done_cv); 269*0Sstevel@tonic-gate } 270*0Sstevel@tonic-gate mutex_exit(&ct->ct_lock); 271*0Sstevel@tonic-gate return (ret); 272*0Sstevel@tonic-gate } 273*0Sstevel@tonic-gate 274*0Sstevel@tonic-gate /* 275*0Sstevel@tonic-gate * callers make sure no recursive entries to this func. 276*0Sstevel@tonic-gate * dp->cc_lockp is registered by callb_add to protect callb_cpr_t structure. 277*0Sstevel@tonic-gate * 278*0Sstevel@tonic-gate * When calling to stop a kernel thread (code == CB_CODE_CPR_CHKPT) we 279*0Sstevel@tonic-gate * use a cv_timedwait() in case the kernel thread is blocked. 280*0Sstevel@tonic-gate * 281*0Sstevel@tonic-gate * Note that this is a generic callback handler for daemon CPR and 282*0Sstevel@tonic-gate * should NOT be changed to accommodate any specific requirement in a daemon. 283*0Sstevel@tonic-gate * Individual daemons that require changes to the handler shall write 284*0Sstevel@tonic-gate * callback routines in their own daemon modules. 285*0Sstevel@tonic-gate */ 286*0Sstevel@tonic-gate boolean_t 287*0Sstevel@tonic-gate callb_generic_cpr(void *arg, int code) 288*0Sstevel@tonic-gate { 289*0Sstevel@tonic-gate callb_cpr_t *cp = (callb_cpr_t *)arg; 290*0Sstevel@tonic-gate clock_t ret = 0; /* assume success */ 291*0Sstevel@tonic-gate 292*0Sstevel@tonic-gate mutex_enter(cp->cc_lockp); 293*0Sstevel@tonic-gate 294*0Sstevel@tonic-gate switch (code) { 295*0Sstevel@tonic-gate case CB_CODE_CPR_CHKPT: 296*0Sstevel@tonic-gate cp->cc_events |= CALLB_CPR_START; 297*0Sstevel@tonic-gate while (!(cp->cc_events & CALLB_CPR_SAFE)) 298*0Sstevel@tonic-gate /* cv_timedwait() returns -1 if it times out. */ 299*0Sstevel@tonic-gate if ((ret = cv_timedwait(&cp->cc_callb_cv, 300*0Sstevel@tonic-gate cp->cc_lockp, 301*0Sstevel@tonic-gate lbolt + callb_timeout_sec * hz)) == -1) 302*0Sstevel@tonic-gate break; 303*0Sstevel@tonic-gate break; 304*0Sstevel@tonic-gate 305*0Sstevel@tonic-gate case CB_CODE_CPR_RESUME: 306*0Sstevel@tonic-gate cp->cc_events &= ~CALLB_CPR_START; 307*0Sstevel@tonic-gate cv_signal(&cp->cc_stop_cv); 308*0Sstevel@tonic-gate break; 309*0Sstevel@tonic-gate } 310*0Sstevel@tonic-gate mutex_exit(cp->cc_lockp); 311*0Sstevel@tonic-gate return (ret != -1); 312*0Sstevel@tonic-gate } 313*0Sstevel@tonic-gate 314*0Sstevel@tonic-gate /* 315*0Sstevel@tonic-gate * The generic callback function associated with kernel threads which 316*0Sstevel@tonic-gate * are always considered safe. 317*0Sstevel@tonic-gate */ 318*0Sstevel@tonic-gate /* ARGSUSED */ 319*0Sstevel@tonic-gate boolean_t 320*0Sstevel@tonic-gate callb_generic_cpr_safe(void *arg, int code) 321*0Sstevel@tonic-gate { 322*0Sstevel@tonic-gate return (B_TRUE); 323*0Sstevel@tonic-gate } 324*0Sstevel@tonic-gate /* 325*0Sstevel@tonic-gate * Prevent additions to callback table. 326*0Sstevel@tonic-gate */ 327*0Sstevel@tonic-gate void 328*0Sstevel@tonic-gate callb_lock_table(void) 329*0Sstevel@tonic-gate { 330*0Sstevel@tonic-gate mutex_enter(&ct->ct_lock); 331*0Sstevel@tonic-gate ASSERT(ct->ct_busy == 0); 332*0Sstevel@tonic-gate ct->ct_busy = 1; 333*0Sstevel@tonic-gate mutex_exit(&ct->ct_lock); 334*0Sstevel@tonic-gate } 335*0Sstevel@tonic-gate 336*0Sstevel@tonic-gate /* 337*0Sstevel@tonic-gate * Allow additions to callback table. 338*0Sstevel@tonic-gate */ 339*0Sstevel@tonic-gate void 340*0Sstevel@tonic-gate callb_unlock_table(void) 341*0Sstevel@tonic-gate { 342*0Sstevel@tonic-gate mutex_enter(&ct->ct_lock); 343*0Sstevel@tonic-gate ASSERT(ct->ct_busy != 0); 344*0Sstevel@tonic-gate ct->ct_busy = 0; 345*0Sstevel@tonic-gate cv_broadcast(&ct->ct_busy_cv); 346*0Sstevel@tonic-gate mutex_exit(&ct->ct_lock); 347*0Sstevel@tonic-gate } 348*0Sstevel@tonic-gate 349*0Sstevel@tonic-gate /* 350*0Sstevel@tonic-gate * Return a boolean value indicating whether a particular kernel thread is 351*0Sstevel@tonic-gate * stopped in accordance with the cpr callback protocol. If returning 352*0Sstevel@tonic-gate * false, also return a pointer to the thread name via the 2nd argument. 353*0Sstevel@tonic-gate */ 354*0Sstevel@tonic-gate boolean_t 355*0Sstevel@tonic-gate callb_is_stopped(kthread_id_t tp, caddr_t *thread_name) 356*0Sstevel@tonic-gate { 357*0Sstevel@tonic-gate callb_t *cp; 358*0Sstevel@tonic-gate boolean_t ret_val; 359*0Sstevel@tonic-gate 360*0Sstevel@tonic-gate mutex_enter(&ct->ct_lock); 361*0Sstevel@tonic-gate 362*0Sstevel@tonic-gate for (cp = ct->ct_first_cb[CB_CL_CPR_DAEMON]; 363*0Sstevel@tonic-gate cp != NULL && tp != cp->c_thread; cp = cp->c_next) 364*0Sstevel@tonic-gate ; 365*0Sstevel@tonic-gate 366*0Sstevel@tonic-gate ret_val = (cp != NULL); 367*0Sstevel@tonic-gate if (ret_val) { 368*0Sstevel@tonic-gate /* 369*0Sstevel@tonic-gate * We found the thread in the callback table and have 370*0Sstevel@tonic-gate * provisionally set the return value to true. Now 371*0Sstevel@tonic-gate * see if it is marked "safe" and is sleeping or stopped. 372*0Sstevel@tonic-gate */ 373*0Sstevel@tonic-gate callb_cpr_t *ccp = (callb_cpr_t *)cp->c_arg; 374*0Sstevel@tonic-gate 375*0Sstevel@tonic-gate *thread_name = cp->c_name; /* in case not stopped */ 376*0Sstevel@tonic-gate mutex_enter(ccp->cc_lockp); 377*0Sstevel@tonic-gate 378*0Sstevel@tonic-gate if (ccp->cc_events & CALLB_CPR_SAFE) { 379*0Sstevel@tonic-gate int retry; 380*0Sstevel@tonic-gate 381*0Sstevel@tonic-gate mutex_exit(ccp->cc_lockp); 382*0Sstevel@tonic-gate for (retry = 0; retry < CALLB_MAX_RETRY; retry++) { 383*0Sstevel@tonic-gate thread_lock(tp); 384*0Sstevel@tonic-gate if (tp->t_state & (TS_SLEEP | TS_STOPPED)) { 385*0Sstevel@tonic-gate thread_unlock(tp); 386*0Sstevel@tonic-gate break; 387*0Sstevel@tonic-gate } 388*0Sstevel@tonic-gate thread_unlock(tp); 389*0Sstevel@tonic-gate delay(CALLB_THREAD_DELAY); 390*0Sstevel@tonic-gate } 391*0Sstevel@tonic-gate ret_val = retry < CALLB_MAX_RETRY; 392*0Sstevel@tonic-gate } else { 393*0Sstevel@tonic-gate ret_val = 394*0Sstevel@tonic-gate (ccp->cc_events & CALLB_CPR_ALWAYS_SAFE) != 0; 395*0Sstevel@tonic-gate mutex_exit(ccp->cc_lockp); 396*0Sstevel@tonic-gate } 397*0Sstevel@tonic-gate } else { 398*0Sstevel@tonic-gate /* 399*0Sstevel@tonic-gate * Thread not found in callback table. Make the best 400*0Sstevel@tonic-gate * attempt to identify the thread in the error message. 401*0Sstevel@tonic-gate */ 402*0Sstevel@tonic-gate ulong_t offset; 403*0Sstevel@tonic-gate char *sym = kobj_getsymname((uintptr_t)tp->t_startpc, 404*0Sstevel@tonic-gate &offset); 405*0Sstevel@tonic-gate 406*0Sstevel@tonic-gate *thread_name = sym ? sym : "*unknown*"; 407*0Sstevel@tonic-gate } 408*0Sstevel@tonic-gate 409*0Sstevel@tonic-gate mutex_exit(&ct->ct_lock); 410*0Sstevel@tonic-gate return (ret_val); 411*0Sstevel@tonic-gate } 412