1 /* Program and address space management, for GDB, the GNU debugger.
3 Copyright (C) 2009-2019 Free Software Foundation, Inc.
5 This file is part of GDB.
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.
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.
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/>. */
29 #include "common/next-iterator.h"
30 #include "common/safe-iterator.h"
38 struct program_space_data;
39 struct address_space_data;
41 /* A program space represents a symbolic view of an address space.
42 Roughly speaking, it holds all the data associated with a
43 non-running-yet program (main executable, main symbols), and when
44 an inferior is running and is bound to it, includes the list of its
45 mapped in shared libraries.
47 In the traditional debugging scenario, there's a 1-1 correspondence
48 among program spaces, inferiors and address spaces, like so:
50 pspace1 (prog1) <--> inf1(pid1) <--> aspace1
52 In the case of debugging more than one traditional unix process or
53 program, we still have:
55 |-----------------+------------+---------|
56 | pspace1 (prog1) | inf1(pid1) | aspace1 |
57 |----------------------------------------|
58 | pspace2 (prog1) | no inf yet | aspace2 |
59 |-----------------+------------+---------|
60 | pspace3 (prog2) | inf2(pid2) | aspace3 |
61 |-----------------+------------+---------|
63 In the former example, if inf1 forks (and GDB stays attached to
64 both processes), the new child will have its own program and
65 address spaces. Like so:
67 |-----------------+------------+---------|
68 | pspace1 (prog1) | inf1(pid1) | aspace1 |
69 |-----------------+------------+---------|
70 | pspace2 (prog1) | inf2(pid2) | aspace2 |
71 |-----------------+------------+---------|
73 However, had inf1 from the latter case vforked instead, it would
74 share the program and address spaces with its parent, until it
75 execs or exits, like so:
77 |-----------------+------------+---------|
78 | pspace1 (prog1) | inf1(pid1) | aspace1 |
80 |-----------------+------------+---------|
82 When the vfork child execs, it is finally given new program and
85 |-----------------+------------+---------|
86 | pspace1 (prog1) | inf1(pid1) | aspace1 |
87 |-----------------+------------+---------|
88 | pspace2 (prog1) | inf2(pid2) | aspace2 |
89 |-----------------+------------+---------|
91 There are targets where the OS (if any) doesn't provide memory
92 management or VM protection, where all inferiors share the same
93 address space --- e.g. uClinux. GDB models this by having all
94 inferiors share the same address space, but, giving each its own
95 program space, like so:
97 |-----------------+------------+---------|
98 | pspace1 (prog1) | inf1(pid1) | |
99 |-----------------+------------+ |
100 | pspace2 (prog1) | inf2(pid2) | aspace1 |
101 |-----------------+------------+ |
102 | pspace3 (prog2) | inf3(pid3) | |
103 |-----------------+------------+---------|
105 The address space sharing matters for run control and breakpoints
106 management. E.g., did we just hit a known breakpoint that we need
107 to step over? Is this breakpoint a duplicate of this other one, or
108 do I need to insert a trap?
110 Then, there are targets where all symbols look the same for all
111 inferiors, although each has its own address space, as e.g.,
112 Ericsson DICOS. In such case, the model is:
114 |---------+------------+---------|
115 | | inf1(pid1) | aspace1 |
116 | +------------+---------|
117 | pspace | inf2(pid2) | aspace2 |
118 | +------------+---------|
119 | | inf3(pid3) | aspace3 |
120 |---------+------------+---------|
122 Note however, that the DICOS debug API takes care of making GDB
123 believe that breakpoints are "global". That is, although each
124 process does have its own private copy of data symbols (just like a
125 bunch of forks), to the breakpoints module, all processes share a
126 single address space, so all breakpoints set at the same address
127 are duplicates of each other, even breakpoints set in the data
128 space (e.g., call dummy breakpoints placed on stack). This allows
129 a simplification in the spaces implementation: we avoid caring for
130 a many-many links between address and program spaces. Either
131 there's a single address space bound to the program space
132 (traditional unix/uClinux), or, in the DICOS case, the address
133 space bound to the program space is mostly ignored. */
135 /* The program space structure. */
139 program_space (address_space *aspace_);
142 typedef next_adapter<struct objfile> objfiles_range;
144 /* Return an iterarable object that can be used to iterate over all
145 objfiles. The basic use is in a foreach, like:
147 for (objfile *objf : pspace->objfiles ()) { ... } */
148 objfiles_range objfiles ()
150 return objfiles_range (objfiles_head);
153 typedef next_adapter<struct objfile,
154 basic_safe_iterator<next_iterator<objfile>>>
157 /* An iterable object that can be used to iterate over all objfiles.
158 The basic use is in a foreach, like:
160 for (objfile *objf : pspace->objfiles_safe ()) { ... }
162 This variant uses a basic_safe_iterator so that objfiles can be
163 deleted during iteration. */
164 objfiles_safe_range objfiles_safe ()
166 return objfiles_safe_range (objfiles_head);
169 /* Pointer to next in linked list. */
170 struct program_space *next = NULL;
172 /* Unique ID number. */
175 /* The main executable loaded into this program space. This is
176 managed by the exec target. */
178 /* The BFD handle for the main executable. */
180 /* The last-modified time, from when the exec was brought in. */
182 /* Similar to bfd_get_filename (exec_bfd) but in original form given
183 by user, without symbolic links and pathname resolved.
184 It needs to be freed by xfree. It is not NULL iff EBFD is not NULL. */
185 char *pspace_exec_filename = NULL;
187 /* Binary file diddling handle for the core file. */
188 gdb_bfd_ref_ptr cbfd;
190 /* The address space attached to this program space. More than one
191 program space may be bound to the same address space. In the
192 traditional unix-like debugging scenario, this will usually
193 match the address space bound to the inferior, and is mostly
194 used by the breakpoints module for address matches. If the
195 target shares a program space for all inferiors and breakpoints
196 are global, then this field is ignored (we don't currently
197 support inferiors sharing a program space if the target doesn't
198 make breakpoints global). */
199 struct address_space *aspace = NULL;
201 /* True if this program space's section offsets don't yet represent
202 the final offsets of the "live" address space (that is, the
203 section addresses still require the relocation offsets to be
204 applied, and hence we can't trust the section addresses for
205 anything that pokes at live memory). E.g., for qOffsets
206 targets, or for PIE executables, until we connect and ask the
207 target for the final relocation offsets, the symbols we've used
208 to set breakpoints point at the wrong addresses. */
209 int executing_startup = 0;
211 /* True if no breakpoints should be inserted in this program
213 int breakpoints_not_allowed = 0;
215 /* The object file that the main symbol table was loaded from
216 (e.g. the argument to the "symbol-file" or "file" command). */
217 struct objfile *symfile_object_file = NULL;
219 /* All known objfiles are kept in a linked list. This points to
220 the head of this list. */
221 struct objfile *objfiles_head = NULL;
223 /* The set of target sections matching the sections mapped into
224 this program space. Managed by both exec_ops and solib.c. */
225 struct target_section_table target_sections {};
227 /* List of shared objects mapped into this space. Managed by
229 struct so_list *so_list = NULL;
231 /* Number of calls to solib_add. */
232 unsigned int solib_add_generation = 0;
234 /* When an solib is added, it is also added to this vector. This
235 is so we can properly report solib changes to the user. */
236 std::vector<struct so_list *> added_solibs;
238 /* When an solib is removed, its name is added to this vector.
239 This is so we can properly report solib changes to the user. */
240 std::vector<std::string> deleted_solibs;
242 /* Per pspace data-pointers required by other GDB modules. */
246 /* An address space. It is used for comparing if
247 pspaces/inferior/threads see the same address space and for
248 associating caches to each address space. */
253 /* Per aspace data-pointers required by other GDB modules. */
257 /* The object file that the main symbol table was loaded from (e.g. the
258 argument to the "symbol-file" or "file" command). */
260 #define symfile_objfile current_program_space->symfile_object_file
262 /* All known objfiles are kept in a linked list. This points to the
263 root of this list. */
264 #define object_files current_program_space->objfiles_head
266 /* The set of target sections matching the sections mapped into the
267 current program space. */
268 #define current_target_sections (¤t_program_space->target_sections)
270 /* The list of all program spaces. There's always at least one. */
271 extern struct program_space *program_spaces;
273 /* The current program space. This is always non-null. */
274 extern struct program_space *current_program_space;
276 #define ALL_PSPACES(pspace) \
277 for ((pspace) = program_spaces; (pspace) != NULL; (pspace) = (pspace)->next)
279 /* Remove a program space from the program spaces list and release it. It is
280 an error to call this function while PSPACE is the current program space. */
281 extern void delete_program_space (struct program_space *pspace);
283 /* Returns the number of program spaces listed. */
284 extern int number_of_program_spaces (void);
286 /* Returns true iff there's no inferior bound to PSPACE. */
287 extern int program_space_empty_p (struct program_space *pspace);
289 /* Copies program space SRC to DEST. Copies the main executable file,
290 and the main symbol file. Returns DEST. */
291 extern struct program_space *clone_program_space (struct program_space *dest,
292 struct program_space *src);
294 /* Sets PSPACE as the current program space. This is usually used
295 instead of set_current_space_and_thread when the current
296 thread/inferior is not important for the operations that follow.
297 E.g., when accessing the raw symbol tables. If memory access is
298 required, then you should use switch_to_program_space_and_thread.
299 Otherwise, it is the caller's responsibility to make sure that the
300 currently selected inferior/thread matches the selected program
302 extern void set_current_program_space (struct program_space *pspace);
304 /* Save/restore the current program space. */
306 class scoped_restore_current_program_space
309 scoped_restore_current_program_space ()
310 : m_saved_pspace (current_program_space)
313 ~scoped_restore_current_program_space ()
314 { set_current_program_space (m_saved_pspace); }
316 DISABLE_COPY_AND_ASSIGN (scoped_restore_current_program_space);
319 program_space *m_saved_pspace;
322 /* Create a new address space object, and add it to the list. */
323 extern struct address_space *new_address_space (void);
325 /* Maybe create a new address space object, and add it to the list, or
326 return a pointer to an existing address space, in case inferiors
327 share an address space. */
328 extern struct address_space *maybe_new_address_space (void);
330 /* Returns the integer address space id of ASPACE. */
331 extern int address_space_num (struct address_space *aspace);
333 /* Update all program spaces matching to address spaces. The user may
334 have created several program spaces, and loaded executables into
335 them before connecting to the target interface that will create the
336 inferiors. All that happens before GDB has a chance to know if the
337 inferiors will share an address space or not. Call this after
338 having connected to the target interface and having fetched the
339 target description, to fixup the program/address spaces
341 extern void update_address_spaces (void);
343 /* Reset saved solib data at the start of an solib event. This lets
344 us properly collect the data when calling solib_add, so it can then
346 extern void clear_program_space_solib_cache (struct program_space *);
348 /* Keep a registry of per-pspace data-pointers required by other GDB
351 DECLARE_REGISTRY (program_space);
353 /* Keep a registry of per-aspace data-pointers required by other GDB
356 DECLARE_REGISTRY (address_space);