1/* libunwind - a platform-independent unwind library
2 Copyright (C) 2002-2004 Hewlett-Packard Co
3 Contributed by David Mosberger-Tang <davidm@hpl.hp.com>
4
5This file is part of libunwind.
6
7Permission is hereby granted, free of charge, to any person obtaining
8a copy of this software and associated documentation files (the
9"Software"), to deal in the Software without restriction, including
10without limitation the rights to use, copy, modify, merge, publish,
11distribute, sublicense, and/or sell copies of the Software, and to
12permit persons to whom the Software is furnished to do so, subject to
13the following conditions:
14
15The above copyright notice and this permission notice shall be
16included in all copies or substantial portions of the Software.
17
18THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
19EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
20MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
21NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
22LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
23OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
24WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
25
26/* This file defines the runtime-support routines for dynamically
27generated code. Even though it is implemented as part of libunwind,
28it is logically separate from the interface to perform the actual
29unwinding. In particular, this interface is always used in the
30context of the unwind target, whereas the rest of the unwind API is
31used in context of the process that is doing the unwind (which may be
32a debugger running on another machine, for example).
33
34Note that the data-structures declared here server a dual purpose:
35when a program registers a dynamically generated procedure, it uses
36these structures directly. On the other hand, with remote-unwinding,
37the data-structures are read from the remote process's memory and
38translated into internalized versions. To facilitate remote-access,
39the following rules should be followed in declaring these structures:
40
41 (1) Declare a member as a pointer only if the the information the
42 member points to needs to be internalized as well (e.g., a
43 string representing a procedure name should be declared as
44 "const char *", but the instruction pointer should be declared
45 as unw_word_t).
46
47 (2) Provide sufficient padding to ensure that no implicit padding
48 will be needed on any of the supported target architectures. For
49 the time being, padding data structures with the assumption that
50 sizeof (unw_word_t) == 8 should be sufficient. (Note: it's not
51 impossible to internalize structures with internal padding, but
52 it does make the process a bit harder).
53
54 (3) Don't declare members that contain bitfields or floating-point
55 values.
56
57 (4) Don't declare members with enumeration types. Declare them as
58 int32_t instead. */
59
60typedef enum
61 {
62 UNW_DYN_STOP = 0, /* end-of-unwind-info marker */
63 UNW_DYN_SAVE_REG, /* save register to another register */
64 UNW_DYN_SPILL_FP_REL, /* frame-pointer-relative register spill */
65 UNW_DYN_SPILL_SP_REL, /* stack-pointer-relative register spill */
66 UNW_DYN_ADD, /* add constant value to a register */
67 UNW_DYN_POP_FRAMES, /* drop one or more stack frames */
68 UNW_DYN_LABEL_STATE, /* name the current state */
69 UNW_DYN_COPY_STATE, /* set the region's entry-state */
70 UNW_DYN_ALIAS /* get unwind info from an alias */
71 }
72unw_dyn_operation_t;
73
74typedef enum
75 {
76 UNW_INFO_FORMAT_DYNAMIC, /* unw_dyn_proc_info_t */
77 UNW_INFO_FORMAT_TABLE, /* unw_dyn_table_t */
78 UNW_INFO_FORMAT_REMOTE_TABLE, /* unw_dyn_remote_table_t */
79 UNW_INFO_FORMAT_ARM_EXIDX, /* ARM specific unwind info */
80 UNW_INFO_FORMAT_IP_OFFSET, /* Like UNW_INFO_FORMAT_REMOTE_TABLE, but
81 table entries are considered
82 relative to di->start_ip, rather
83 than di->segbase */
84 }
85unw_dyn_info_format_t;
86
87typedef struct unw_dyn_op
88 {
89 int8_t tag; /* what operation? */
90 int8_t qp; /* qualifying predicate register */
91 int16_t reg; /* what register */
92 int32_t when; /* when does it take effect? */
93 unw_word_t val; /* auxiliary value */
94 }
95unw_dyn_op_t;
96
97typedef struct unw_dyn_region_info
98 {
99 struct unw_dyn_region_info *next; /* linked list of regions */
100 int32_t insn_count; /* region length (# of instructions) */
101 uint32_t op_count; /* length of op-array */
102 unw_dyn_op_t op[1]; /* variable-length op-array */
103 }
104unw_dyn_region_info_t;
105
106typedef struct unw_dyn_proc_info
107 {
108 unw_word_t name_ptr; /* address of human-readable procedure name */
109 unw_word_t handler; /* address of personality routine */
110 uint32_t flags;
111 int32_t pad0;
112 unw_dyn_region_info_t *regions;
113 }
114unw_dyn_proc_info_t;
115
116typedef struct unw_dyn_table_info
117 {
118 unw_word_t name_ptr; /* addr. of table name (e.g., library name) */
119 unw_word_t segbase; /* segment base */
120 unw_word_t table_len; /* must be a multiple of sizeof(unw_word_t)! */
121 unw_word_t *table_data;
122 }
123unw_dyn_table_info_t;
124
125typedef struct unw_dyn_remote_table_info
126 {
127 unw_word_t name_ptr; /* addr. of table name (e.g., library name) */
128 unw_word_t segbase; /* segment base */
129 unw_word_t table_len; /* must be a multiple of sizeof(unw_word_t)! */
130 unw_word_t table_data;
131 }
132unw_dyn_remote_table_info_t;
133
134typedef struct unw_dyn_info
135 {
136 /* doubly-linked list of dyn-info structures: */
137 struct unw_dyn_info *next;
138 struct unw_dyn_info *prev;
139 unw_word_t start_ip; /* first IP covered by this entry */
140 unw_word_t end_ip; /* first IP NOT covered by this entry */
141 unw_word_t gp; /* global-pointer in effect for this entry */
142 int32_t format; /* real type: unw_dyn_info_format_t */
143 int32_t pad;
144 union
145 {
146 unw_dyn_proc_info_t pi;
147 unw_dyn_table_info_t ti;
148 unw_dyn_remote_table_info_t rti;
149 }
150 u;
151 }
152unw_dyn_info_t;
153
154typedef struct unw_dyn_info_list
155 {
156 uint32_t version;
157 uint32_t generation;
158 unw_dyn_info_t *first;
159 }
160unw_dyn_info_list_t;
161
162/* Return the size (in bytes) of an unw_dyn_region_info_t structure that can
163 hold OP_COUNT ops. */
164#define _U_dyn_region_info_size(op_count) \
165 ((char *) (((unw_dyn_region_info_t *) NULL)->op + (op_count)) \
166 - (char *) NULL)
167
168/* Register the unwind info for a single procedure.
169 This routine is NOT signal-safe. */
170extern void _U_dyn_register (unw_dyn_info_t *);
171
172/* Cancel the unwind info for a single procedure.
173 This routine is NOT signal-safe. */
174extern void _U_dyn_cancel (unw_dyn_info_t *);
175
176
177/* Convenience routines. */
178
179#define _U_dyn_op(_tag, _qp, _when, _reg, _val) \
180 ((unw_dyn_op_t) { (_tag), (_qp), (_reg), (_when), (_val) })
181
182#define _U_dyn_op_save_reg(op, qp, when, reg, dst) \
183 (*(op) = _U_dyn_op (UNW_DYN_SAVE_REG, (qp), (when), (reg), (dst)))
184
185#define _U_dyn_op_spill_fp_rel(op, qp, when, reg, offset) \
186 (*(op) = _U_dyn_op (UNW_DYN_SPILL_FP_REL, (qp), (when), (reg), \
187 (offset)))
188
189#define _U_dyn_op_spill_sp_rel(op, qp, when, reg, offset) \
190 (*(op) = _U_dyn_op (UNW_DYN_SPILL_SP_REL, (qp), (when), (reg), \
191 (offset)))
192
193#define _U_dyn_op_add(op, qp, when, reg, value) \
194 (*(op) = _U_dyn_op (UNW_DYN_ADD, (qp), (when), (reg), (value)))
195
196#define _U_dyn_op_pop_frames(op, qp, when, num_frames) \
197 (*(op) = _U_dyn_op (UNW_DYN_POP_FRAMES, (qp), (when), 0, (num_frames)))
198
199#define _U_dyn_op_label_state(op, label) \
200 (*(op) = _U_dyn_op (UNW_DYN_LABEL_STATE, _U_QP_TRUE, -1, 0, (label)))
201
202#define _U_dyn_op_copy_state(op, label) \
203 (*(op) = _U_dyn_op (UNW_DYN_COPY_STATE, _U_QP_TRUE, -1, 0, (label)))
204
205#define _U_dyn_op_alias(op, qp, when, addr) \
206 (*(op) = _U_dyn_op (UNW_DYN_ALIAS, (qp), (when), 0, (addr)))
207
208#define _U_dyn_op_stop(op) \
209 (*(op) = _U_dyn_op (UNW_DYN_STOP, _U_QP_TRUE, -1, 0, 0))
210
211/* The target-dependent qualifying predicate which is always TRUE. On
212 IA-64, that's p0 (0), on non-predicated architectures, the value is
213 ignored. */
214#define _U_QP_TRUE _U_TDEP_QP_TRUE
215

source code of include/x86_64-linux-gnu/libunwind-dynamic.h