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 "stack_unwind.h"
32 #include "reg_num.h"
33 #include <dlfcn.h>
34
35 /*
36 * Due to the subtle mysteries of the amd64 unwind interfaces, the
37 * "Canonical Frame Address" is 16 bytes higher in memory than the
38 * value of the frame pointer (%fp).
39 */
40 #define CFA_ADJUST 16
41
42 /* ARGSUSED */
43 static _Unwind_Reason_Code
posix_stop_func(int version,_Unwind_Action _Unwind_actions,uint64_t exceptionClass,struct _Unwind_Exception * exceptionObject,struct _Unwind_Context * context,void * func_arg)44 posix_stop_func(
45 int version,
46 _Unwind_Action _Unwind_actions,
47 uint64_t exceptionClass,
48 struct _Unwind_Exception *exceptionObject,
49 struct _Unwind_Context *context,
50 void *func_arg)
51 {
52 __cleanup_t **headp = (__cleanup_t **)func_arg;
53 __cleanup_t *head;
54 uint64_t cfa;
55
56 /*
57 * If we have reached the origin of the stack, exit now.
58 */
59 cfa = _Unwind_GetCFA(context);
60 if (cfa == 0 || _Unwind_GetGR(context, RET_ADD) == 0) {
61 _Unwind_DeleteException(exceptionObject);
62 _thrp_exit();
63 thr_panic("posix_stop_func(): _thrp_exit() returned");
64 }
65
66 /*
67 * Call all Posix cleanup handlers for this frame.
68 */
69 while ((head = *headp) != NULL &&
70 (caddr_t)cfa == head->fp + CFA_ADJUST) {
71 *headp = head->next;
72 (*head->func)(head->arg);
73 }
74
75 return (_URC_NO_REASON);
76 }
77
78 /*
79 * _ex_unwind() is provided by libCrun to perform stack unwinding
80 * and calling C++ destructors as needed, interleaved with calling
81 * Posix cleanup handlers along the way. If libCrun is not present
82 * we just need to call the Posix cleanup handlers.
83 */
84
85 /* ARGSUSED */
86 void
_thrp_unwind(void * dummy)87 _thrp_unwind(void *dummy)
88 {
89 ulwp_t *self = curthread;
90 __cleanup_t **headp = &self->ul_clnup_hdr;
91 __cleanup_t *head;
92 void (*fptr)(_Unwind_Stop_Fn, void *);
93
94 /* Do this once per thread exit, not once per unwind frame */
95 if (self->ul_ex_unwind == NULL &&
96 (self->ul_ex_unwind = dlsym(RTLD_PROBE, "_ex_unwind")) == NULL)
97 self->ul_ex_unwind = (void *)-1;
98
99 if (self->ul_ex_unwind == (void *)-1)
100 fptr = NULL;
101 else
102 fptr = (void (*)())self->ul_ex_unwind;
103
104 /*
105 * Call _ex_unwind() if it is present (C++ loaded),
106 * else just call the Posix cleanup handlers.
107 */
108 if (fptr != NULL)
109 (*fptr)(posix_stop_func, headp);
110
111 /*
112 * Call all remaining Posix cleanup handlers.
113 */
114 while ((head = *headp) != NULL) {
115 *headp = head->next;
116 (*head->func)(head->arg);
117 }
118
119 _thrp_exit();
120 thr_panic("_thrp_unwind(): _thrp_exit() returned");
121 }
122