1 /* Copyright (C) 2003, 2004, 2005 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3 Contributed by Ulrich Drepper <drepper@redhat.com>
4 and Richard Henderson <rth@redhat.com>, 2003.
6 The GNU C Library is free software; you can redistribute it and/or
7 modify it under the terms of the GNU Lesser General Public
8 License as published by the Free Software Foundation; either
9 version 2.1 of the License, or (at your option) any later version.
11 The GNU C Library is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Lesser General Public License for more details.
16 You should have received a copy of the GNU Lesser General Public
17 License along with the GNU C Library; if not, write to the Free
18 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
26 #include <jmpbuf-unwind.h>
28 #ifdef HAVE_FORCED_UNWIND
30 #ifdef _STACK_GROWS_DOWN
31 # define FRAME_LEFT(frame, other, adj) \
32 ((uintptr_t) frame - adj >= (uintptr_t) other - adj)
33 #elif defined _STACK_GROWS_UP
34 # define FRAME_LEFT(frame, other, adj) \
35 ((uintptr_t) frame - adj <= (uintptr_t) other - adj)
37 # error "Define either _STACK_GROWS_DOWN or _STACK_GROWS_UP"
40 static _Unwind_Reason_Code
41 unwind_stop (int version, _Unwind_Action actions,
42 _Unwind_Exception_Class exc_class,
43 struct _Unwind_Exception *exc_obj,
44 struct _Unwind_Context *context, void *stop_parameter)
46 struct pthread_unwind_buf *buf = stop_parameter;
47 struct pthread *self = THREAD_SELF;
48 struct _pthread_cleanup_buffer *curp = THREAD_GETMEM (self, cleanup);
51 /* Adjust all pointers used in comparisons, so that top of thread's
52 stack is at the top of address space. Without that, things break
53 if stack is allocated above the main stack. */
54 uintptr_t adj = (uintptr_t) self->stackblock + self->stackblock_size;
56 /* Do longjmp if we're at "end of stack", aka "end of unwind data".
57 We assume there are only C frame without unwind data in between
58 here and the jmp_buf target. Otherwise simply note that the CFA
59 of a function is NOT within it's stack frame; it's the SP of the
61 if ((actions & _UA_END_OF_STACK)
62 || ! _JMPBUF_CFA_UNWINDS_ADJ (buf->cancel_jmp_buf[0].jmp_buf, context,
66 if (__builtin_expect (curp != NULL, 0))
68 /* Handle the compatibility stuff. Execute all handlers
69 registered with the old method which would be unwound by this
71 struct _pthread_cleanup_buffer *oldp = buf->priv.data.cleanup;
72 void *cfa = (void *) _Unwind_GetCFA (context);
74 if (curp != oldp && (do_longjump || FRAME_LEFT (cfa, curp, adj)))
78 /* Pointer to the next element. */
79 struct _pthread_cleanup_buffer *nextp = curp->__prev;
81 /* Call the handler. */
82 curp->__routine (curp->__arg);
88 && (do_longjump || FRAME_LEFT (cfa, curp, adj)));
90 /* Mark the current element as handled. */
91 THREAD_SETMEM (self, cleanup, curp);
96 __libc_unwind_longjmp ((struct __jmp_buf_tag *) buf->cancel_jmp_buf, 1);
98 return _URC_NO_REASON;
102 static attribute_noreturn void
103 unwind_cleanup (_Unwind_Reason_Code reason, struct _Unwind_Exception *exc)
105 /* When we get here a C++ catch block didn't rethrow the object. We
106 cannot handle this case and therefore abort. */
107 # define STR_N_LEN(str) str, strlen (str)
108 INTERNAL_SYSCALL_DECL (err);
109 INTERNAL_SYSCALL (write, err, 3, STDERR_FILENO,
110 STR_N_LEN ("FATAL: exception not rethrown\n"));
114 #endif /* have forced unwind */
118 /*does not apply due to hidden_proto(): attribute_protected*/
119 __cleanup_fct_attribute __attribute ((noreturn))
120 #if !defined SHARED && !defined IS_IN_libpthread
123 __pthread_unwind (__pthread_unwind_buf_t *buf)
125 struct pthread_unwind_buf *ibuf = (struct pthread_unwind_buf *) buf;
126 struct pthread *self = THREAD_SELF;
128 #ifdef HAVE_FORCED_UNWIND
129 /* This is not a catchable exception, so don't provide any details about
130 the exception type. We do need to initialize the field though. */
131 THREAD_SETMEM (self, exc.exception_class, 0);
132 THREAD_SETMEM (self, exc.exception_cleanup, unwind_cleanup);
134 _Unwind_ForcedUnwind (&self->exc, unwind_stop, ibuf);
136 /* Handle the compatibility stuff first. Execute all handlers
137 registered with the old method. We don't execute them in order,
138 instead, they will run first. */
139 struct _pthread_cleanup_buffer *oldp = ibuf->priv.data.cleanup;
140 struct _pthread_cleanup_buffer *curp = THREAD_GETMEM (self, cleanup);
146 /* Pointer to the next element. */
147 struct _pthread_cleanup_buffer *nextp = curp->__prev;
149 /* Call the handler. */
150 curp->__routine (curp->__arg);
155 while (curp != oldp);
157 /* Mark the current element as handled. */
158 THREAD_SETMEM (self, cleanup, curp);
161 /* We simply jump to the registered setjmp buffer. */
162 __libc_unwind_longjmp ((struct __jmp_buf_tag *) ibuf->cancel_jmp_buf, 1);
166 /* We better do not get here. */
169 hidden_def (__pthread_unwind)
173 __cleanup_fct_attribute __attribute ((noreturn))
174 __pthread_unwind_next (__pthread_unwind_buf_t *buf)
176 struct pthread_unwind_buf *ibuf = (struct pthread_unwind_buf *) buf;
178 __pthread_unwind ((__pthread_unwind_buf_t *) ibuf->priv.data.prev);
180 hidden_def (__pthread_unwind_next)