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1 /* Program and address space management, for GDB, the GNU debugger.
2 
3  Copyright (C) 2009-2015 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 struct address_space_data;
37 
38 typedef struct so_list *so_list_ptr;
39 DEF_VEC_P (so_list_ptr);
40 
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.
46 
47  In the traditional debugging scenario, there's a 1-1 correspondence
48  among program spaces, inferiors and address spaces, like so:
49 
50  pspace1 (prog1) <--> inf1(pid1) <--> aspace1
51 
52  In the case of debugging more than one traditional unix process or
53  program, we still have:
54 
55  |-----------------+------------+---------|
56  | pspace1 (prog1) | inf1(pid1) | aspace1 |
57  |----------------------------------------|
58  | pspace2 (prog1) | no inf yet | aspace2 |
59  |-----------------+------------+---------|
60  | pspace3 (prog2) | inf2(pid2) | aspace3 |
61  |-----------------+------------+---------|
62 
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:
66 
67  |-----------------+------------+---------|
68  | pspace1 (prog1) | inf1(pid1) | aspace1 |
69  |-----------------+------------+---------|
70  | pspace2 (prog1) | inf2(pid2) | aspace2 |
71  |-----------------+------------+---------|
72 
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:
76 
77  |-----------------+------------+---------|
78  | pspace1 (prog1) | inf1(pid1) | aspace1 |
79  | | inf2(pid2) | |
80  |-----------------+------------+---------|
81 
82  When the vfork child execs, it is finally given new program and
83  address spaces.
84 
85  |-----------------+------------+---------|
86  | pspace1 (prog1) | inf1(pid1) | aspace1 |
87  |-----------------+------------+---------|
88  | pspace2 (prog1) | inf2(pid2) | aspace2 |
89  |-----------------+------------+---------|
90 
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:
96 
97  |-----------------+------------+---------|
98  | pspace1 (prog1) | inf1(pid1) | |
99  |-----------------+------------+ |
100  | pspace2 (prog1) | inf2(pid2) | aspace1 |
101  |-----------------+------------+ |
102  | pspace3 (prog2) | inf3(pid3) | |
103  |-----------------+------------+---------|
104 
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?
109 
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:
113 
114  |---------+------------+---------|
115  | | inf1(pid1) | aspace1 |
116  | +------------+---------|
117  | pspace | inf2(pid2) | aspace2 |
118  | +------------+---------|
119  | | inf3(pid3) | aspace3 |
120  |---------+------------+---------|
121 
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. */
134 
135 /* The program space structure. */
136 
138  {
139  /* Pointer to next in linked list. */
141 
142  /* Unique ID number. */
143  int num;
144 
145  /* The main executable loaded into this program space. This is
146  managed by the exec target. */
147 
148  /* The BFD handle for the main executable. */
149  bfd *ebfd;
150  /* The last-modified time, from when the exec was brought in. */
152  /* Similar to bfd_get_filename (exec_bfd) but in original form given
153  by user, without symbolic links and pathname resolved.
154  It needs to be freed by xfree. It is not NULL iff EBFD is not NULL. */
156 
157  /* The address space attached to this program space. More than one
158  program space may be bound to the same address space. In the
159  traditional unix-like debugging scenario, this will usually
160  match the address space bound to the inferior, and is mostly
161  used by the breakpoints module for address matches. If the
162  target shares a program space for all inferiors and breakpoints
163  are global, then this field is ignored (we don't currently
164  support inferiors sharing a program space if the target doesn't
165  make breakpoints global). */
167 
168  /* True if this program space's section offsets don't yet represent
169  the final offsets of the "live" address space (that is, the
170  section addresses still require the relocation offsets to be
171  applied, and hence we can't trust the section addresses for
172  anything that pokes at live memory). E.g., for qOffsets
173  targets, or for PIE executables, until we connect and ask the
174  target for the final relocation offsets, the symbols we've used
175  to set breakpoints point at the wrong addresses. */
177 
178  /* True if no breakpoints should be inserted in this program
179  space. */
181 
182  /* The object file that the main symbol table was loaded from
183  (e.g. the argument to the "symbol-file" or "file" command). */
185 
186  /* All known objfiles are kept in a linked list. This points to
187  the head of this list. */
188  struct objfile *objfiles;
189 
190  /* The set of target sections matching the sections mapped into
191  this program space. Managed by both exec_ops and solib.c. */
193 
194  /* List of shared objects mapped into this space. Managed by
195  solib.c. */
196  struct so_list *so_list;
197 
198  /* Number of calls to solib_add. */
200 
201  /* When an solib is added, it is also added to this vector. This
202  is so we can properly report solib changes to the user. */
203  VEC (so_list_ptr) *added_solibs;
204 
205  /* When an solib is removed, its name is added to this vector.
206  This is so we can properly report solib changes to the user. */
207  VEC (char_ptr) *deleted_solibs;
208 
209  /* Per pspace data-pointers required by other GDB modules. */
211  };
212 
213 /* The object file that the main symbol table was loaded from (e.g. the
214  argument to the "symbol-file" or "file" command). */
215 
216 #define symfile_objfile current_program_space->symfile_object_file
217 
218 /* All known objfiles are kept in a linked list. This points to the
219  root of this list. */
220 #define object_files current_program_space->objfiles
221 
222 /* The set of target sections matching the sections mapped into the
223  current program space. */
224 #define current_target_sections (&current_program_space->target_sections)
225 
226 /* The list of all program spaces. There's always at least one. */
227 extern struct program_space *program_spaces;
228 
229 /* The current program space. This is always non-null. */
230 extern struct program_space *current_program_space;
231 
232 #define ALL_PSPACES(pspace) \
233  for ((pspace) = program_spaces; (pspace) != NULL; (pspace) = (pspace)->next)
234 
235 /* Add a new empty program space, and assign ASPACE to it. Returns the
236  pointer to the new object. */
237 extern struct program_space *add_program_space (struct address_space *aspace);
238 
239 /* Returns the number of program spaces listed. */
240 extern int number_of_program_spaces (void);
241 
242 /* Copies program space SRC to DEST. Copies the main executable file,
243  and the main symbol file. Returns DEST. */
244 extern struct program_space *clone_program_space (struct program_space *dest,
245  struct program_space *src);
246 
247 /* Save the current program space so that it may be restored by a later
248  call to do_cleanups. Returns the struct cleanup pointer needed for
249  later doing the cleanup. */
250 extern struct cleanup *save_current_program_space (void);
251 
252 /* Sets PSPACE as the current program space. This is usually used
253  instead of set_current_space_and_thread when the current
254  thread/inferior is not important for the operations that follow.
255  E.g., when accessing the raw symbol tables. If memory access is
256  required, then you should use switch_to_program_space_and_thread.
257  Otherwise, it is the caller's responsibility to make sure that the
258  currently selected inferior/thread matches the selected program
259  space. */
260 extern void set_current_program_space (struct program_space *pspace);
261 
262 /* Saves the current thread (may be null), frame and program space in
263  the current cleanup chain. */
264 extern struct cleanup *save_current_space_and_thread (void);
265 
266 /* Switches full context to program space PSPACE. Switches to the
267  first thread found bound to PSPACE, giving preference to the
268  current thread, if there's one and it isn't executing. */
269 extern void switch_to_program_space_and_thread (struct program_space *pspace);
270 
271 /* Create a new address space object, and add it to the list. */
272 extern struct address_space *new_address_space (void);
273 
274 /* Maybe create a new address space object, and add it to the list, or
275  return a pointer to an existing address space, in case inferiors
276  share an address space. */
277 extern struct address_space *maybe_new_address_space (void);
278 
279 /* Returns the integer address space id of ASPACE. */
280 extern int address_space_num (struct address_space *aspace);
281 
282 /* Update all program spaces matching to address spaces. The user may
283  have created several program spaces, and loaded executables into
284  them before connecting to the target interface that will create the
285  inferiors. All that happens before GDB has a chance to know if the
286  inferiors will share an address space or not. Call this after
287  having connected to the target interface and having fetched the
288  target description, to fixup the program/address spaces
289  mappings. */
290 extern void update_address_spaces (void);
291 
292 /* Prune away automatically added program spaces that aren't required
293  anymore. */
294 extern void prune_program_spaces (void);
295 
296 /* Reset saved solib data at the start of an solib event. This lets
297  us properly collect the data when calling solib_add, so it can then
298  later be printed. */
299 extern void clear_program_space_solib_cache (struct program_space *);
300 
301 /* Keep a registry of per-pspace data-pointers required by other GDB
302  modules. */
303 
305 
306 /* Keep a registry of per-aspace data-pointers required by other GDB
307  modules. */
308 
310 
311 #endif
struct objfile * objfiles
Definition: progspace.h:188
struct cleanup * save_current_space_and_thread(void)
Definition: progspace.c:448
struct address_space * aspace
Definition: progspace.h:166
struct program_space * add_program_space(struct address_space *aspace)
Definition: progspace.c:125
void set_current_program_space(struct program_space *pspace)
Definition: progspace.c:199
struct objfile * symfile_object_file
Definition: progspace.h:184
struct so_list * so_list_ptr
Definition: progspace.h:38
int address_space_num(struct address_space *aspace)
Definition: progspace.c:106
int breakpoints_not_allowed
Definition: progspace.h:180
Definition: solist.h:30
char * char_ptr
Definition: gdb_vecs.h:25
void update_address_spaces(void)
Definition: progspace.c:413
struct program_space * current_program_space
Definition: progspace.c:35
struct target_section_table target_sections
Definition: progspace.h:192
struct so_list * so_list
Definition: progspace.h:196
void switch_to_program_space_and_thread(struct program_space *pspace)
Definition: progspace.c:465
void clear_program_space_solib_cache(struct program_space *)
Definition: progspace.c:493
DEF_VEC_P(so_list_ptr)
DECLARE_REGISTRY(program_space)
unsigned solib_add_generation
Definition: progspace.h:199
struct cleanup * save_current_program_space(void)
Definition: progspace.c:228
struct address_space * new_address_space(void)
Definition: progspace.c:69
void prune_program_spaces(void)
Definition: progspace.c:251
long ebfd_mtime
Definition: progspace.h:151
int executing_startup
Definition: progspace.h:176
char * pspace_exec_filename
Definition: progspace.h:155
int number_of_program_spaces(void)
Definition: progspace.c:390
struct address_space * maybe_new_address_space(void)
Definition: progspace.c:85
VEC(so_list_ptr)*added_solibs
struct program_space * program_spaces
Definition: progspace.c:32
struct program_space * clone_program_space(struct program_space *dest, struct program_space *src)
Definition: progspace.c:176
struct program_space * next
Definition: progspace.h:140