1 /* Program and address space management, for GDB, the GNU debugger. 2 3 Copyright (C) 2009-2013 Free Software Foundation, Inc. 4 5 This file is part of GDB. 6 7 This program is free software; you can redistribute it and/or modify 8 it under the terms of the GNU General Public License as published by 9 the Free Software Foundation; either version 3 of the License, or 10 (at your option) any later version. 11 12 This program is distributed in the hope that it will be useful, 13 but WITHOUT ANY WARRANTY; without even the implied warranty of 14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 GNU General Public License for more details. 16 17 You should have received a copy of the GNU General Public License 18 along with this program. If not, see <http://www.gnu.org/licenses/>. */ 19 20 21 #ifndef PROGSPACE_H 22 #define PROGSPACE_H 23 24 #include "target.h" 25 #include "vec.h" 26 #include "gdb_vecs.h" 27 #include "registry.h" 28 29 struct target_ops; 30 struct bfd; 31 struct objfile; 32 struct inferior; 33 struct exec; 34 struct address_space; 35 struct program_space_data; 36 37 typedef struct so_list *so_list_ptr; 38 DEF_VEC_P (so_list_ptr); 39 40 /* A program space represents a symbolic view of an address space. 41 Roughly speaking, it holds all the data associated with a 42 non-running-yet program (main executable, main symbols), and when 43 an inferior is running and is bound to it, includes the list of its 44 mapped in shared libraries. 45 46 In the traditional debugging scenario, there's a 1-1 correspondence 47 among program spaces, inferiors and address spaces, like so: 48 49 pspace1 (prog1) <--> inf1(pid1) <--> aspace1 50 51 In the case of debugging more than one traditional unix process or 52 program, we still have: 53 54 |-----------------+------------+---------| 55 | pspace1 (prog1) | inf1(pid1) | aspace1 | 56 |----------------------------------------| 57 | pspace2 (prog1) | no inf yet | aspace2 | 58 |-----------------+------------+---------| 59 | pspace3 (prog2) | inf2(pid2) | aspace3 | 60 |-----------------+------------+---------| 61 62 In the former example, if inf1 forks (and GDB stays attached to 63 both processes), the new child will have its own program and 64 address spaces. Like so: 65 66 |-----------------+------------+---------| 67 | pspace1 (prog1) | inf1(pid1) | aspace1 | 68 |-----------------+------------+---------| 69 | pspace2 (prog1) | inf2(pid2) | aspace2 | 70 |-----------------+------------+---------| 71 72 However, had inf1 from the latter case vforked instead, it would 73 share the program and address spaces with its parent, until it 74 execs or exits, like so: 75 76 |-----------------+------------+---------| 77 | pspace1 (prog1) | inf1(pid1) | aspace1 | 78 | | inf2(pid2) | | 79 |-----------------+------------+---------| 80 81 When the vfork child execs, it is finally given new program and 82 address spaces. 83 84 |-----------------+------------+---------| 85 | pspace1 (prog1) | inf1(pid1) | aspace1 | 86 |-----------------+------------+---------| 87 | pspace2 (prog1) | inf2(pid2) | aspace2 | 88 |-----------------+------------+---------| 89 90 There are targets where the OS (if any) doesn't provide memory 91 management or VM protection, where all inferiors share the same 92 address space --- e.g. uClinux. GDB models this by having all 93 inferiors share the same address space, but, giving each its own 94 program space, like so: 95 96 |-----------------+------------+---------| 97 | pspace1 (prog1) | inf1(pid1) | | 98 |-----------------+------------+ | 99 | pspace2 (prog1) | inf2(pid2) | aspace1 | 100 |-----------------+------------+ | 101 | pspace3 (prog2) | inf3(pid3) | | 102 |-----------------+------------+---------| 103 104 The address space sharing matters for run control and breakpoints 105 management. E.g., did we just hit a known breakpoint that we need 106 to step over? Is this breakpoint a duplicate of this other one, or 107 do I need to insert a trap? 108 109 Then, there are targets where all symbols look the same for all 110 inferiors, although each has its own address space, as e.g., 111 Ericsson DICOS. In such case, the model is: 112 113 |---------+------------+---------| 114 | | inf1(pid1) | aspace1 | 115 | +------------+---------| 116 | pspace | inf2(pid2) | aspace2 | 117 | +------------+---------| 118 | | inf3(pid3) | aspace3 | 119 |---------+------------+---------| 120 121 Note however, that the DICOS debug API takes care of making GDB 122 believe that breakpoints are "global". That is, although each 123 process does have its own private copy of data symbols (just like a 124 bunch of forks), to the breakpoints module, all processes share a 125 single address space, so all breakpoints set at the same address 126 are duplicates of each other, even breakpoints set in the data 127 space (e.g., call dummy breakpoints placed on stack). This allows 128 a simplification in the spaces implementation: we avoid caring for 129 a many-many links between address and program spaces. Either 130 there's a single address space bound to the program space 131 (traditional unix/uClinux), or, in the DICOS case, the address 132 space bound to the program space is mostly ignored. */ 133 134 /* The program space structure. */ 135 136 struct program_space 137 { 138 /* Pointer to next in linked list. */ 139 struct program_space *next; 140 141 /* Unique ID number. */ 142 int num; 143 144 /* The main executable loaded into this program space. This is 145 managed by the exec target. */ 146 147 /* The BFD handle for the main executable. */ 148 bfd *ebfd; 149 /* The last-modified time, from when the exec was brought in. */ 150 long ebfd_mtime; 151 /* Similar to bfd_get_filename (exec_bfd) but in original form given 152 by user, without symbolic links and pathname resolved. 153 It needs to be freed by xfree. It is not NULL iff EBFD is not NULL. */ 154 char *pspace_exec_filename; 155 156 /* The address space attached to this program space. More than one 157 program space may be bound to the same address space. In the 158 traditional unix-like debugging scenario, this will usually 159 match the address space bound to the inferior, and is mostly 160 used by the breakpoints module for address matches. If the 161 target shares a program space for all inferiors and breakpoints 162 are global, then this field is ignored (we don't currently 163 support inferiors sharing a program space if the target doesn't 164 make breakpoints global). */ 165 struct address_space *aspace; 166 167 /* True if this program space's section offsets don't yet represent 168 the final offsets of the "live" address space (that is, the 169 section addresses still require the relocation offsets to be 170 applied, and hence we can't trust the section addresses for 171 anything that pokes at live memory). E.g., for qOffsets 172 targets, or for PIE executables, until we connect and ask the 173 target for the final relocation offsets, the symbols we've used 174 to set breakpoints point at the wrong addresses. */ 175 int executing_startup; 176 177 /* True if no breakpoints should be inserted in this program 178 space. */ 179 int breakpoints_not_allowed; 180 181 /* The object file that the main symbol table was loaded from 182 (e.g. the argument to the "symbol-file" or "file" command). */ 183 struct objfile *symfile_object_file; 184 185 /* All known objfiles are kept in a linked list. This points to 186 the head of this list. */ 187 struct objfile *objfiles; 188 189 /* The set of target sections matching the sections mapped into 190 this program space. Managed by both exec_ops and solib.c. */ 191 struct target_section_table target_sections; 192 193 /* List of shared objects mapped into this space. Managed by 194 solib.c. */ 195 struct so_list *so_list; 196 197 /* Number of calls to solib_add. */ 198 unsigned solib_add_generation; 199 200 /* When an solib is added, it is also added to this vector. This 201 is so we can properly report solib changes to the user. */ 202 VEC (so_list_ptr) *added_solibs; 203 204 /* When an solib is removed, its name is added to this vector. 205 This is so we can properly report solib changes to the user. */ 206 VEC (char_ptr) *deleted_solibs; 207 208 /* Per pspace data-pointers required by other GDB modules. */ 209 REGISTRY_FIELDS; 210 }; 211 212 /* The object file that the main symbol table was loaded from (e.g. the 213 argument to the "symbol-file" or "file" command). */ 214 215 #define symfile_objfile current_program_space->symfile_object_file 216 217 /* All known objfiles are kept in a linked list. This points to the 218 root of this list. */ 219 #define object_files current_program_space->objfiles 220 221 /* The set of target sections matching the sections mapped into the 222 current program space. */ 223 #define current_target_sections (¤t_program_space->target_sections) 224 225 /* The list of all program spaces. There's always at least one. */ 226 extern struct program_space *program_spaces; 227 228 /* The current program space. This is always non-null. */ 229 extern struct program_space *current_program_space; 230 231 #define ALL_PSPACES(pspace) \ 232 for ((pspace) = program_spaces; (pspace) != NULL; (pspace) = (pspace)->next) 233 234 /* Add a new empty program space, and assign ASPACE to it. Returns the 235 pointer to the new object. */ 236 extern struct program_space *add_program_space (struct address_space *aspace); 237 238 /* Release PSPACE and removes it from the pspace list. */ 239 extern void remove_program_space (struct program_space *pspace); 240 241 /* Returns the number of program spaces listed. */ 242 extern int number_of_program_spaces (void); 243 244 /* Copies program space SRC to DEST. Copies the main executable file, 245 and the main symbol file. Returns DEST. */ 246 extern struct program_space *clone_program_space (struct program_space *dest, 247 struct program_space *src); 248 249 /* Save the current program space so that it may be restored by a later 250 call to do_cleanups. Returns the struct cleanup pointer needed for 251 later doing the cleanup. */ 252 extern struct cleanup *save_current_program_space (void); 253 254 /* Sets PSPACE as the current program space. This is usually used 255 instead of set_current_space_and_thread when the current 256 thread/inferior is not important for the operations that follow. 257 E.g., when accessing the raw symbol tables. If memory access is 258 required, then you should use switch_to_program_space_and_thread. 259 Otherwise, it is the caller's responsibility to make sure that the 260 currently selected inferior/thread matches the selected program 261 space. */ 262 extern void set_current_program_space (struct program_space *pspace); 263 264 /* Saves the current thread (may be null), frame and program space in 265 the current cleanup chain. */ 266 extern struct cleanup *save_current_space_and_thread (void); 267 268 /* Switches full context to program space PSPACE. Switches to the 269 first thread found bound to PSPACE. */ 270 extern void switch_to_program_space_and_thread (struct program_space *pspace); 271 272 /* Create a new address space object, and add it to the list. */ 273 extern struct address_space *new_address_space (void); 274 275 /* Maybe create a new address space object, and add it to the list, or 276 return a pointer to an existing address space, in case inferiors 277 share an address space. */ 278 extern struct address_space *maybe_new_address_space (void); 279 280 /* Returns the integer address space id of ASPACE. */ 281 extern int address_space_num (struct address_space *aspace); 282 283 /* Update all program spaces matching to address spaces. The user may 284 have created several program spaces, and loaded executables into 285 them before connecting to the target interface that will create the 286 inferiors. All that happens before GDB has a chance to know if the 287 inferiors will share an address space or not. Call this after 288 having connected to the target interface and having fetched the 289 target description, to fixup the program/address spaces 290 mappings. */ 291 extern void update_address_spaces (void); 292 293 /* Prune away automatically added program spaces that aren't required 294 anymore. */ 295 extern void prune_program_spaces (void); 296 297 /* Reset saved solib data at the start of an solib event. This lets 298 us properly collect the data when calling solib_add, so it can then 299 later be printed. */ 300 extern void clear_program_space_solib_cache (struct program_space *); 301 302 /* Keep a registry of per-pspace data-pointers required by other GDB 303 modules. */ 304 305 DECLARE_REGISTRY (program_space); 306 307 #endif 308