1 /* Program and address space management, for GDB, the GNU debugger.
3 Copyright (C) 2009-2024 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/>. */
26 #include "gdbsupport/gdb_vecs.h"
29 #include "gdbsupport/next-iterator.h"
30 #include "gdbsupport/safe-iterator.h"
31 #include "gdbsupport/intrusive_list.h"
32 #include "gdbsupport/refcounted-object.h"
33 #include "gdbsupport/gdb_ref_ptr.h"
46 typedef std::list
<std::unique_ptr
<objfile
>> objfile_list
;
48 /* An address space. It is used for comparing if
49 pspaces/inferior/threads see the same address space and for
50 associating caches to each address space. */
51 struct address_space
: public refcounted_object
53 /* Create a new address space object, and add it to the list. */
55 DISABLE_COPY_AND_ASSIGN (address_space
);
57 /* Returns the integer address space id of this address space. */
63 /* Per aspace data-pointers required by other GDB modules. */
64 registry
<address_space
> registry_fields
;
70 using address_space_ref_ptr
71 = gdb::ref_ptr
<address_space
,
72 refcounted_object_delete_ref_policy
<address_space
>>;
74 /* Create a new address space. */
76 static inline address_space_ref_ptr
79 return address_space_ref_ptr::new_reference (new address_space
);
82 /* An iterator that wraps an iterator over std::unique_ptr<objfile>,
83 and dereferences the returned object. This is useful for iterating
84 over a list of shared pointers and returning raw pointers -- which
85 helped avoid touching a lot of code when changing how objfiles are
88 class unwrapping_objfile_iterator
92 typedef unwrapping_objfile_iterator self_type
;
93 typedef typename ::objfile
*value_type
;
94 typedef typename ::objfile
&reference
;
95 typedef typename ::objfile
**pointer
;
96 typedef typename
objfile_list::iterator::iterator_category iterator_category
;
97 typedef typename
objfile_list::iterator::difference_type difference_type
;
99 unwrapping_objfile_iterator (objfile_list::iterator iter
)
100 : m_iter (std::move (iter
))
104 objfile
*operator* () const
106 return m_iter
->get ();
109 unwrapping_objfile_iterator
operator++ ()
115 bool operator!= (const unwrapping_objfile_iterator
&other
) const
117 return m_iter
!= other
.m_iter
;
122 /* The underlying iterator. */
123 objfile_list::iterator m_iter
;
127 /* A range that returns unwrapping_objfile_iterators. */
129 using unwrapping_objfile_range
= iterator_range
<unwrapping_objfile_iterator
>;
131 /* A program space represents a symbolic view of an address space.
132 Roughly speaking, it holds all the data associated with a
133 non-running-yet program (main executable, main symbols), and when
134 an inferior is running and is bound to it, includes the list of its
135 mapped in shared libraries.
137 In the traditional debugging scenario, there's a 1-1 correspondence
138 among program spaces, inferiors and address spaces, like so:
140 pspace1 (prog1) <--> inf1(pid1) <--> aspace1
142 In the case of debugging more than one traditional unix process or
143 program, we still have:
145 |-----------------+------------+---------|
146 | pspace1 (prog1) | inf1(pid1) | aspace1 |
147 |----------------------------------------|
148 | pspace2 (prog1) | no inf yet | aspace2 |
149 |-----------------+------------+---------|
150 | pspace3 (prog2) | inf2(pid2) | aspace3 |
151 |-----------------+------------+---------|
153 In the former example, if inf1 forks (and GDB stays attached to
154 both processes), the new child will have its own program and
155 address spaces. Like so:
157 |-----------------+------------+---------|
158 | pspace1 (prog1) | inf1(pid1) | aspace1 |
159 |-----------------+------------+---------|
160 | pspace2 (prog1) | inf2(pid2) | aspace2 |
161 |-----------------+------------+---------|
163 However, had inf1 from the latter case vforked instead, it would
164 share the program and address spaces with its parent, until it
165 execs or exits, like so:
167 |-----------------+------------+---------|
168 | pspace1 (prog1) | inf1(pid1) | aspace1 |
170 |-----------------+------------+---------|
172 When the vfork child execs, it is finally given new program and
175 |-----------------+------------+---------|
176 | pspace1 (prog1) | inf1(pid1) | aspace1 |
177 |-----------------+------------+---------|
178 | pspace2 (prog1) | inf2(pid2) | aspace2 |
179 |-----------------+------------+---------|
181 There are targets where the OS (if any) doesn't provide memory
182 management or VM protection, where all inferiors share the same
183 address space --- e.g. uClinux. GDB models this by having all
184 inferiors share the same address space, but, giving each its own
185 program space, like so:
187 |-----------------+------------+---------|
188 | pspace1 (prog1) | inf1(pid1) | |
189 |-----------------+------------+ |
190 | pspace2 (prog1) | inf2(pid2) | aspace1 |
191 |-----------------+------------+ |
192 | pspace3 (prog2) | inf3(pid3) | |
193 |-----------------+------------+---------|
195 The address space sharing matters for run control and breakpoints
196 management. E.g., did we just hit a known breakpoint that we need
197 to step over? Is this breakpoint a duplicate of this other one, or
198 do I need to insert a trap?
200 Then, there are targets where all symbols look the same for all
201 inferiors, although each has its own address space, as e.g.,
202 Ericsson DICOS. In such case, the model is:
204 |---------+------------+---------|
205 | | inf1(pid1) | aspace1 |
206 | +------------+---------|
207 | pspace | inf2(pid2) | aspace2 |
208 | +------------+---------|
209 | | inf3(pid3) | aspace3 |
210 |---------+------------+---------|
212 Note however, that the DICOS debug API takes care of making GDB
213 believe that breakpoints are "global". That is, although each
214 process does have its own private copy of data symbols (just like a
215 bunch of forks), to the breakpoints module, all processes share a
216 single address space, so all breakpoints set at the same address
217 are duplicates of each other, even breakpoints set in the data
218 space (e.g., call dummy breakpoints placed on stack). This allows
219 a simplification in the spaces implementation: we avoid caring for
220 a many-many links between address and program spaces. Either
221 there's a single address space bound to the program space
222 (traditional unix/uClinux), or, in the DICOS case, the address
223 space bound to the program space is mostly ignored. */
225 /* The program space structure. */
229 /* Constructs a new empty program space, binds it to ASPACE, and
230 adds it to the program space list. */
231 explicit program_space (address_space_ref_ptr aspace
);
233 /* Releases a program space, and all its contents (shared libraries,
234 objfiles, and any other references to the program space in other
235 modules). It is an internal error to call this when the program
236 space is the current program space, since there should always be
240 using objfiles_range
= unwrapping_objfile_range
;
242 /* Return an iterable object that can be used to iterate over all
243 objfiles. The basic use is in a foreach, like:
245 for (objfile *objf : pspace->objfiles ()) { ... } */
246 objfiles_range
objfiles ()
248 return objfiles_range
249 (unwrapping_objfile_iterator (objfiles_list
.begin ()),
250 unwrapping_objfile_iterator (objfiles_list
.end ()));
253 using objfiles_safe_range
= basic_safe_range
<objfiles_range
>;
255 /* An iterable object that can be used to iterate over all objfiles.
256 The basic use is in a foreach, like:
258 for (objfile *objf : pspace->objfiles_safe ()) { ... }
260 This variant uses a basic_safe_iterator so that objfiles can be
261 deleted during iteration. */
262 objfiles_safe_range
objfiles_safe ()
264 return objfiles_safe_range
266 (unwrapping_objfile_iterator (objfiles_list
.begin ()),
267 unwrapping_objfile_iterator (objfiles_list
.end ())));
270 /* Add OBJFILE to the list of objfiles, putting it just before
271 BEFORE. If BEFORE is nullptr, it will go at the end of the
273 void add_objfile (std::unique_ptr
<objfile
> &&objfile
,
274 struct objfile
*before
);
276 /* Remove OBJFILE from the list of objfiles. */
277 void remove_objfile (struct objfile
*objfile
);
279 /* Return true if there is more than one object file loaded; false
281 bool multi_objfile_p () const
283 return objfiles_list
.size () > 1;
286 /* Free all the objfiles associated with this program space. */
287 void free_all_objfiles ();
289 /* Return the objfile containing ADDRESS, or nullptr if the address
290 is outside all objfiles in this progspace. */
291 struct objfile
*objfile_for_address (CORE_ADDR address
);
293 /* Return the list of all the solibs in this program space. */
294 intrusive_list
<shobj
> &solibs ()
297 /* Close and clear exec_bfd. If we end up with no target sections
298 to read memory from, this unpushes the exec_ops target. */
301 /* Return the exec BFD for this program space. */
302 bfd
*exec_bfd () const
307 /* Set the exec BFD for this program space to ABFD. */
308 void set_exec_bfd (gdb_bfd_ref_ptr
&&abfd
)
310 ebfd
= std::move (abfd
);
313 /* Reset saved solib data at the start of an solib event. This lets
314 us properly collect the data when calling solib_add, so it can then
316 void clear_solib_cache ();
318 /* Returns true iff there's no inferior bound to this program
322 /* Remove all target sections owned by OWNER. */
323 void remove_target_sections (target_section_owner owner
);
325 /* Add the sections array defined by SECTIONS to the
326 current set of target sections. */
327 void add_target_sections (target_section_owner owner
,
328 const std::vector
<target_section
> §ions
);
330 /* Add the sections of OBJFILE to the current set of target
331 sections. They are given OBJFILE as the "owner". */
332 void add_target_sections (struct objfile
*objfile
);
334 /* Clear all target sections from M_TARGET_SECTIONS table. */
335 void clear_target_sections ()
337 m_target_sections
.clear ();
340 /* Return a reference to the M_TARGET_SECTIONS table. */
341 std::vector
<target_section
> &target_sections ()
343 return m_target_sections
;
346 /* Unique ID number. */
349 /* The main executable loaded into this program space. This is
350 managed by the exec target. */
352 /* The BFD handle for the main executable. */
353 gdb_bfd_ref_ptr ebfd
;
354 /* The last-modified time, from when the exec was brought in. */
356 /* Similar to bfd_get_filename (exec_bfd) but in original form given
357 by user, without symbolic links and pathname resolved. It is not
358 NULL iff EBFD is not NULL. */
359 gdb::unique_xmalloc_ptr
<char> exec_filename
;
361 /* Binary file diddling handle for the core file. */
362 gdb_bfd_ref_ptr cbfd
;
364 /* The address space attached to this program space. More than one
365 program space may be bound to the same address space. In the
366 traditional unix-like debugging scenario, this will usually
367 match the address space bound to the inferior, and is mostly
368 used by the breakpoints module for address matches. If the
369 target shares a program space for all inferiors and breakpoints
370 are global, then this field is ignored (we don't currently
371 support inferiors sharing a program space if the target doesn't
372 make breakpoints global). */
373 address_space_ref_ptr aspace
;
375 /* True if this program space's section offsets don't yet represent
376 the final offsets of the "live" address space (that is, the
377 section addresses still require the relocation offsets to be
378 applied, and hence we can't trust the section addresses for
379 anything that pokes at live memory). E.g., for qOffsets
380 targets, or for PIE executables, until we connect and ask the
381 target for the final relocation offsets, the symbols we've used
382 to set breakpoints point at the wrong addresses. */
383 int executing_startup
= 0;
385 /* True if no breakpoints should be inserted in this program
387 int breakpoints_not_allowed
= 0;
389 /* The object file that the main symbol table was loaded from
390 (e.g. the argument to the "symbol-file" or "file" command). */
391 struct objfile
*symfile_object_file
= NULL
;
393 /* All known objfiles are kept in a linked list. */
394 std::list
<std::unique_ptr
<objfile
>> objfiles_list
;
396 /* List of shared objects mapped into this space. Managed by
398 intrusive_list
<shobj
> so_list
;
400 /* Number of calls to solib_add. */
401 unsigned int solib_add_generation
= 0;
403 /* When an solib is added, it is also added to this vector. This
404 is so we can properly report solib changes to the user. */
405 std::vector
<shobj
*> added_solibs
;
407 /* When an solib is removed, its name is added to this vector.
408 This is so we can properly report solib changes to the user. */
409 std::vector
<std::string
> deleted_solibs
;
411 /* Per pspace data-pointers required by other GDB modules. */
412 registry
<program_space
> registry_fields
;
415 /* The set of target sections matching the sections mapped into
416 this program space. Managed by both exec_ops and solib.c. */
417 std::vector
<target_section
> m_target_sections
;
420 /* The list of all program spaces. There's always at least one. */
421 extern std::vector
<struct program_space
*>program_spaces
;
423 /* The current program space. This is always non-null. */
424 extern struct program_space
*current_program_space
;
426 /* Copies program space SRC to DEST. Copies the main executable file,
427 and the main symbol file. Returns DEST. */
428 extern struct program_space
*clone_program_space (struct program_space
*dest
,
429 struct program_space
*src
);
431 /* Sets PSPACE as the current program space. This is usually used
432 instead of set_current_space_and_thread when the current
433 thread/inferior is not important for the operations that follow.
434 E.g., when accessing the raw symbol tables. If memory access is
435 required, then you should use switch_to_program_space_and_thread.
436 Otherwise, it is the caller's responsibility to make sure that the
437 currently selected inferior/thread matches the selected program
439 extern void set_current_program_space (struct program_space
*pspace
);
441 /* Save/restore the current program space. */
443 class scoped_restore_current_program_space
446 scoped_restore_current_program_space ()
447 : m_saved_pspace (current_program_space
)
450 ~scoped_restore_current_program_space ()
451 { set_current_program_space (m_saved_pspace
); }
453 DISABLE_COPY_AND_ASSIGN (scoped_restore_current_program_space
);
456 program_space
*m_saved_pspace
;
459 /* Maybe create a new address space object, and add it to the list, or
460 return a pointer to an existing address space, in case inferiors
461 share an address space. */
462 extern address_space_ref_ptr
maybe_new_address_space ();
464 /* Update all program spaces matching to address spaces. The user may
465 have created several program spaces, and loaded executables into
466 them before connecting to the target interface that will create the
467 inferiors. All that happens before GDB has a chance to know if the
468 inferiors will share an address space or not. Call this after
469 having connected to the target interface and having fetched the
470 target description, to fixup the program/address spaces
472 extern void update_address_spaces (void);