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 2005 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 "lint.h" 30*0Sstevel@tonic-gate #include "thr_uberdata.h" 31*0Sstevel@tonic-gate #include <dlfcn.h> 32*0Sstevel@tonic-gate 33*0Sstevel@tonic-gate /* 34*0Sstevel@tonic-gate * This is common code for sparc, sparcv9, and i386. 35*0Sstevel@tonic-gate * The amd64 unwind code is vastly different from this. 36*0Sstevel@tonic-gate * Look under the amd64-specific directory structure for details. 37*0Sstevel@tonic-gate */ 38*0Sstevel@tonic-gate 39*0Sstevel@tonic-gate /* 40*0Sstevel@tonic-gate * _ex_unwind() is provided by libC, but if libC is not loaded we 41*0Sstevel@tonic-gate * need to call a local version of _ex_unwind() which does exactly 42*0Sstevel@tonic-gate * the same thing except for calling C++ destructors. 43*0Sstevel@tonic-gate */ 44*0Sstevel@tonic-gate extern void _ex_clnup_handler(void *, void (*)(void *)); 45*0Sstevel@tonic-gate extern void _ex_unwind_local(void); 46*0Sstevel@tonic-gate #pragma unknown_control_flow(_ex_clnup_handler) 47*0Sstevel@tonic-gate #pragma unknown_control_flow(_ex_unwind_local) 48*0Sstevel@tonic-gate 49*0Sstevel@tonic-gate /* 50*0Sstevel@tonic-gate * _t_cancel(fp):calls cleanup handlers if there are any in 51*0Sstevel@tonic-gate * frame (fp), and calls _ex_unwind() to call 52*0Sstevel@tonic-gate * destructors if libC has been linked. 53*0Sstevel@tonic-gate * 54*0Sstevel@tonic-gate * Control comes here from _thrp_unwind. Logically: 55*0Sstevel@tonic-gate * 56*0Sstevel@tonic-gate * _thrp_unwind: first arg = current fp; 57*0Sstevel@tonic-gate * jump _t_cancel; 58*0Sstevel@tonic-gate * 59*0Sstevel@tonic-gate * We could have called _t_cancel(_getfp) from _thr_exit() 60*0Sstevel@tonic-gate * but _ex_unwind() also calls _t_cancel() and it does after 61*0Sstevel@tonic-gate * poping out the two frames. If _ex_unwind() passes the current 62*0Sstevel@tonic-gate * fp, then it will be invalid. For a caller of _thrp_unwind() 63*0Sstevel@tonic-gate * it looks as if it is calling _t_cancel(fp). 64*0Sstevel@tonic-gate * 65*0Sstevel@tonic-gate * _t_cancel will eventually call _thrp_exit(). 66*0Sstevel@tonic-gate * It never returns from _t_cancel(). 67*0Sstevel@tonic-gate * 68*0Sstevel@tonic-gate */ 69*0Sstevel@tonic-gate void 70*0Sstevel@tonic-gate _t_cancel(void *fp) 71*0Sstevel@tonic-gate { 72*0Sstevel@tonic-gate ulwp_t *self = curthread; 73*0Sstevel@tonic-gate __cleanup_t *head; 74*0Sstevel@tonic-gate void (*fptr)(void (*func)(void *), void *arg); 75*0Sstevel@tonic-gate 76*0Sstevel@tonic-gate /* Do this once per thread exit, not once per unwind frame */ 77*0Sstevel@tonic-gate if (self->ul_ex_unwind == NULL && 78*0Sstevel@tonic-gate (self->ul_ex_unwind = dlsym(RTLD_PROBE, "_ex_unwind")) == NULL) 79*0Sstevel@tonic-gate self->ul_ex_unwind = (void *)-1; 80*0Sstevel@tonic-gate 81*0Sstevel@tonic-gate if (self->ul_ex_unwind == (void *)-1) 82*0Sstevel@tonic-gate fptr = NULL; 83*0Sstevel@tonic-gate else 84*0Sstevel@tonic-gate fptr = (void (*)())self->ul_ex_unwind; 85*0Sstevel@tonic-gate 86*0Sstevel@tonic-gate if (fp == NULL) { 87*0Sstevel@tonic-gate _thrp_exit(); 88*0Sstevel@tonic-gate thr_panic("_t_cancel(): _thrp_exit() returned"); 89*0Sstevel@tonic-gate } 90*0Sstevel@tonic-gate 91*0Sstevel@tonic-gate if ((head = self->ul_clnup_hdr) != NULL && fp == head->fp) { 92*0Sstevel@tonic-gate self->ul_clnup_hdr = head->next; 93*0Sstevel@tonic-gate /* execute the cleanup handler */ 94*0Sstevel@tonic-gate _ex_clnup_handler(head->arg, head->func); 95*0Sstevel@tonic-gate thr_panic("_t_cancel(): _ex_clnup_handler() returned"); 96*0Sstevel@tonic-gate } 97*0Sstevel@tonic-gate 98*0Sstevel@tonic-gate if (fptr != NULL && self->ul_unwind) { 99*0Sstevel@tonic-gate /* libC is loaded and thread is canceled, call libC version */ 100*0Sstevel@tonic-gate (*fptr)(_thrp_unwind, NULL); 101*0Sstevel@tonic-gate thr_panic("_t_cancel(): _ex_unwind() returned"); 102*0Sstevel@tonic-gate } else if (head != NULL) { 103*0Sstevel@tonic-gate /* libC not present, call local version */ 104*0Sstevel@tonic-gate _ex_unwind_local(); 105*0Sstevel@tonic-gate thr_panic("_t_cancel(): _ex_unwind_local() returned"); 106*0Sstevel@tonic-gate } else { 107*0Sstevel@tonic-gate /* libC not present and no cleanup handlers, exit here */ 108*0Sstevel@tonic-gate _thrp_exit(); 109*0Sstevel@tonic-gate thr_panic("_t_cancel(): _thrp_exit() returned"); 110*0Sstevel@tonic-gate } 111*0Sstevel@tonic-gate /* never returns here */ 112*0Sstevel@tonic-gate } 113