1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 22 /* 23 * Copyright 2008 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 #pragma ident "%Z%%M% %I% %E% SMI" 28 29 #include "lint.h" 30 #include "thr_uberdata.h" 31 #include <dlfcn.h> 32 33 /* 34 * This is common code for sparc, sparcv9, and i386. 35 * The amd64 unwind code is vastly different from this. 36 * Look under the amd64-specific directory structure for details. 37 */ 38 39 /* 40 * _ex_unwind() is provided by libC, but if libC is not loaded we 41 * need to call a local version of _ex_unwind() which does exactly 42 * the same thing except for calling C++ destructors. 43 */ 44 extern void _ex_clnup_handler(void *, void (*)(void *)); 45 extern void _ex_unwind_local(void); 46 #pragma unknown_control_flow(_ex_clnup_handler) 47 #pragma unknown_control_flow(_ex_unwind_local) 48 49 /* 50 * _t_cancel(fp):calls cleanup handlers if there are any in 51 * frame (fp), and calls _ex_unwind() to call 52 * destructors if libC has been linked. 53 * 54 * Control comes here from _thrp_unwind. Logically: 55 * 56 * _thrp_unwind: first arg = current fp; 57 * jump _t_cancel; 58 * 59 * We could have called _t_cancel(_getfp) from thr_exit() 60 * but _ex_unwind() also calls _t_cancel() and it does after 61 * poping out the two frames. If _ex_unwind() passes the current 62 * fp, then it will be invalid. For a caller of _thrp_unwind() 63 * it looks as if it is calling _t_cancel(fp). 64 * 65 * _t_cancel will eventually call _thrp_exit(). 66 * It never returns from _t_cancel(). 67 * 68 */ 69 void 70 _t_cancel(void *fp) 71 { 72 ulwp_t *self = curthread; 73 __cleanup_t *head; 74 void (*fptr)(void (*func)(void *), void *arg); 75 76 /* Do this once per thread exit, not once per unwind frame */ 77 if (self->ul_ex_unwind == NULL && 78 (self->ul_ex_unwind = dlsym(RTLD_PROBE, "_ex_unwind")) == NULL) 79 self->ul_ex_unwind = (void *)-1; 80 81 if (self->ul_ex_unwind == (void *)-1) 82 fptr = NULL; 83 else 84 fptr = (void (*)())self->ul_ex_unwind; 85 86 if (fp == NULL) { 87 _thrp_exit(); 88 thr_panic("_t_cancel(): _thrp_exit() returned"); 89 } 90 91 if ((head = self->ul_clnup_hdr) != NULL && fp == head->fp) { 92 self->ul_clnup_hdr = head->next; 93 /* execute the cleanup handler */ 94 _ex_clnup_handler(head->arg, head->func); 95 thr_panic("_t_cancel(): _ex_clnup_handler() returned"); 96 } 97 98 if (fptr != NULL && self->ul_unwind) { 99 /* libC is loaded and thread is canceled, call libC version */ 100 (*fptr)(_thrp_unwind, NULL); 101 thr_panic("_t_cancel(): _ex_unwind() returned"); 102 } else if (head != NULL) { 103 /* libC not present, call local version */ 104 _ex_unwind_local(); 105 thr_panic("_t_cancel(): _ex_unwind_local() returned"); 106 } else { 107 /* libC not present and no cleanup handlers, exit here */ 108 _thrp_exit(); 109 thr_panic("_t_cancel(): _thrp_exit() returned"); 110 } 111 /* never returns here */ 112 } 113