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