| /* Program and address space management, for GDB, the GNU debugger. |
| |
| Copyright (C) 2009-2021 Free Software Foundation, Inc. |
| |
| This file is part of GDB. |
| |
| This program is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 3 of the License, or |
| (at your option) any later version. |
| |
| This program is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| GNU General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| |
| |
| #ifndef PROGSPACE_H |
| #define PROGSPACE_H |
| |
| #include "target.h" |
| #include "gdb_bfd.h" |
| #include "gdbsupport/gdb_vecs.h" |
| #include "registry.h" |
| #include "solist.h" |
| #include "gdbsupport/next-iterator.h" |
| #include "gdbsupport/safe-iterator.h" |
| #include <list> |
| #include <vector> |
| |
| struct target_ops; |
| struct bfd; |
| struct objfile; |
| struct inferior; |
| struct exec; |
| struct address_space; |
| struct program_space_data; |
| struct address_space_data; |
| struct so_list; |
| |
| typedef std::list<std::shared_ptr<objfile>> objfile_list; |
| |
| /* An iterator that wraps an iterator over std::shared_ptr<objfile>, |
| and dereferences the returned object. This is useful for iterating |
| over a list of shared pointers and returning raw pointers -- which |
| helped avoid touching a lot of code when changing how objfiles are |
| managed. */ |
| |
| class unwrapping_objfile_iterator |
| { |
| public: |
| |
| typedef unwrapping_objfile_iterator self_type; |
| typedef typename ::objfile *value_type; |
| typedef typename ::objfile &reference; |
| typedef typename ::objfile **pointer; |
| typedef typename objfile_list::iterator::iterator_category iterator_category; |
| typedef typename objfile_list::iterator::difference_type difference_type; |
| |
| unwrapping_objfile_iterator (objfile_list::iterator iter) |
| : m_iter (std::move (iter)) |
| { |
| } |
| |
| objfile *operator* () const |
| { |
| return m_iter->get (); |
| } |
| |
| unwrapping_objfile_iterator operator++ () |
| { |
| ++m_iter; |
| return *this; |
| } |
| |
| bool operator!= (const unwrapping_objfile_iterator &other) const |
| { |
| return m_iter != other.m_iter; |
| } |
| |
| private: |
| |
| /* The underlying iterator. */ |
| objfile_list::iterator m_iter; |
| }; |
| |
| |
| /* A range that returns unwrapping_objfile_iterators. */ |
| |
| using unwrapping_objfile_range = iterator_range<unwrapping_objfile_iterator>; |
| |
| /* A program space represents a symbolic view of an address space. |
| Roughly speaking, it holds all the data associated with a |
| non-running-yet program (main executable, main symbols), and when |
| an inferior is running and is bound to it, includes the list of its |
| mapped in shared libraries. |
| |
| In the traditional debugging scenario, there's a 1-1 correspondence |
| among program spaces, inferiors and address spaces, like so: |
| |
| pspace1 (prog1) <--> inf1(pid1) <--> aspace1 |
| |
| In the case of debugging more than one traditional unix process or |
| program, we still have: |
| |
| |-----------------+------------+---------| |
| | pspace1 (prog1) | inf1(pid1) | aspace1 | |
| |----------------------------------------| |
| | pspace2 (prog1) | no inf yet | aspace2 | |
| |-----------------+------------+---------| |
| | pspace3 (prog2) | inf2(pid2) | aspace3 | |
| |-----------------+------------+---------| |
| |
| In the former example, if inf1 forks (and GDB stays attached to |
| both processes), the new child will have its own program and |
| address spaces. Like so: |
| |
| |-----------------+------------+---------| |
| | pspace1 (prog1) | inf1(pid1) | aspace1 | |
| |-----------------+------------+---------| |
| | pspace2 (prog1) | inf2(pid2) | aspace2 | |
| |-----------------+------------+---------| |
| |
| However, had inf1 from the latter case vforked instead, it would |
| share the program and address spaces with its parent, until it |
| execs or exits, like so: |
| |
| |-----------------+------------+---------| |
| | pspace1 (prog1) | inf1(pid1) | aspace1 | |
| | | inf2(pid2) | | |
| |-----------------+------------+---------| |
| |
| When the vfork child execs, it is finally given new program and |
| address spaces. |
| |
| |-----------------+------------+---------| |
| | pspace1 (prog1) | inf1(pid1) | aspace1 | |
| |-----------------+------------+---------| |
| | pspace2 (prog1) | inf2(pid2) | aspace2 | |
| |-----------------+------------+---------| |
| |
| There are targets where the OS (if any) doesn't provide memory |
| management or VM protection, where all inferiors share the same |
| address space --- e.g. uClinux. GDB models this by having all |
| inferiors share the same address space, but, giving each its own |
| program space, like so: |
| |
| |-----------------+------------+---------| |
| | pspace1 (prog1) | inf1(pid1) | | |
| |-----------------+------------+ | |
| | pspace2 (prog1) | inf2(pid2) | aspace1 | |
| |-----------------+------------+ | |
| | pspace3 (prog2) | inf3(pid3) | | |
| |-----------------+------------+---------| |
| |
| The address space sharing matters for run control and breakpoints |
| management. E.g., did we just hit a known breakpoint that we need |
| to step over? Is this breakpoint a duplicate of this other one, or |
| do I need to insert a trap? |
| |
| Then, there are targets where all symbols look the same for all |
| inferiors, although each has its own address space, as e.g., |
| Ericsson DICOS. In such case, the model is: |
| |
| |---------+------------+---------| |
| | | inf1(pid1) | aspace1 | |
| | +------------+---------| |
| | pspace | inf2(pid2) | aspace2 | |
| | +------------+---------| |
| | | inf3(pid3) | aspace3 | |
| |---------+------------+---------| |
| |
| Note however, that the DICOS debug API takes care of making GDB |
| believe that breakpoints are "global". That is, although each |
| process does have its own private copy of data symbols (just like a |
| bunch of forks), to the breakpoints module, all processes share a |
| single address space, so all breakpoints set at the same address |
| are duplicates of each other, even breakpoints set in the data |
| space (e.g., call dummy breakpoints placed on stack). This allows |
| a simplification in the spaces implementation: we avoid caring for |
| a many-many links between address and program spaces. Either |
| there's a single address space bound to the program space |
| (traditional unix/uClinux), or, in the DICOS case, the address |
| space bound to the program space is mostly ignored. */ |
| |
| /* The program space structure. */ |
| |
| struct program_space |
| { |
| /* Constructs a new empty program space, binds it to ASPACE, and |
| adds it to the program space list. */ |
| explicit program_space (address_space *aspace); |
| |
| /* Releases a program space, and all its contents (shared libraries, |
| objfiles, and any other references to the program space in other |
| modules). It is an internal error to call this when the program |
| space is the current program space, since there should always be |
| a program space. */ |
| ~program_space (); |
| |
| using objfiles_range = unwrapping_objfile_range; |
| |
| /* Return an iterable object that can be used to iterate over all |
| objfiles. The basic use is in a foreach, like: |
| |
| for (objfile *objf : pspace->objfiles ()) { ... } */ |
| objfiles_range objfiles () |
| { |
| return objfiles_range |
| (unwrapping_objfile_iterator (objfiles_list.begin ()), |
| unwrapping_objfile_iterator (objfiles_list.end ())); |
| } |
| |
| using objfiles_safe_range = basic_safe_range<objfiles_range>; |
| |
| /* An iterable object that can be used to iterate over all objfiles. |
| The basic use is in a foreach, like: |
| |
| for (objfile *objf : pspace->objfiles_safe ()) { ... } |
| |
| This variant uses a basic_safe_iterator so that objfiles can be |
| deleted during iteration. */ |
| objfiles_safe_range objfiles_safe () |
| { |
| return objfiles_safe_range |
| (objfiles_range |
| (unwrapping_objfile_iterator (objfiles_list.begin ()), |
| unwrapping_objfile_iterator (objfiles_list.end ()))); |
| } |
| |
| /* Add OBJFILE to the list of objfiles, putting it just before |
| BEFORE. If BEFORE is nullptr, it will go at the end of the |
| list. */ |
| void add_objfile (std::shared_ptr<objfile> &&objfile, |
| struct objfile *before); |
| |
| /* Remove OBJFILE from the list of objfiles. */ |
| void remove_objfile (struct objfile *objfile); |
| |
| /* Return true if there is more than one object file loaded; false |
| otherwise. */ |
| bool multi_objfile_p () const |
| { |
| return objfiles_list.size () > 1; |
| } |
| |
| /* Free all the objfiles associated with this program space. */ |
| void free_all_objfiles (); |
| |
| /* Return a range adapter for iterating over all the solibs in this |
| program space. Use it like: |
| |
| for (so_list *so : pspace->solibs ()) { ... } */ |
| so_list_range solibs () const |
| { return so_list_range (this->so_list); } |
| |
| /* Close and clear exec_bfd. If we end up with no target sections |
| to read memory from, this unpushes the exec_ops target. */ |
| void exec_close (); |
| |
| /* Return the exec BFD for this program space. */ |
| bfd *exec_bfd () const |
| { |
| return ebfd.get (); |
| } |
| |
| /* Set the exec BFD for this program space to ABFD. */ |
| void set_exec_bfd (gdb_bfd_ref_ptr &&abfd) |
| { |
| ebfd = std::move (abfd); |
| } |
| |
| /* Reset saved solib data at the start of an solib event. This lets |
| us properly collect the data when calling solib_add, so it can then |
| later be printed. */ |
| void clear_solib_cache (); |
| |
| /* Returns true iff there's no inferior bound to this program |
| space. */ |
| bool empty (); |
| |
| /* Remove all target sections owned by OWNER. */ |
| void remove_target_sections (void *owner); |
| |
| /* Add the sections array defined by SECTIONS to the |
| current set of target sections. */ |
| void add_target_sections (void *owner, |
| const target_section_table §ions); |
| |
| /* Add the sections of OBJFILE to the current set of target |
| sections. They are given OBJFILE as the "owner". */ |
| void add_target_sections (struct objfile *objfile); |
| |
| /* Clear all target sections from M_TARGET_SECTIONS table. */ |
| void clear_target_sections () |
| { |
| m_target_sections.clear (); |
| } |
| |
| /* Return a reference to the M_TARGET_SECTIONS table. */ |
| target_section_table &target_sections () |
| { |
| return m_target_sections; |
| } |
| |
| /* Unique ID number. */ |
| int num = 0; |
| |
| /* The main executable loaded into this program space. This is |
| managed by the exec target. */ |
| |
| /* The BFD handle for the main executable. */ |
| gdb_bfd_ref_ptr ebfd; |
| /* The last-modified time, from when the exec was brought in. */ |
| long ebfd_mtime = 0; |
| /* Similar to bfd_get_filename (exec_bfd) but in original form given |
| by user, without symbolic links and pathname resolved. It is not |
| NULL iff EBFD is not NULL. */ |
| gdb::unique_xmalloc_ptr<char> exec_filename; |
| |
| /* Binary file diddling handle for the core file. */ |
| gdb_bfd_ref_ptr cbfd; |
| |
| /* The address space attached to this program space. More than one |
| program space may be bound to the same address space. In the |
| traditional unix-like debugging scenario, this will usually |
| match the address space bound to the inferior, and is mostly |
| used by the breakpoints module for address matches. If the |
| target shares a program space for all inferiors and breakpoints |
| are global, then this field is ignored (we don't currently |
| support inferiors sharing a program space if the target doesn't |
| make breakpoints global). */ |
| struct address_space *aspace = NULL; |
| |
| /* True if this program space's section offsets don't yet represent |
| the final offsets of the "live" address space (that is, the |
| section addresses still require the relocation offsets to be |
| applied, and hence we can't trust the section addresses for |
| anything that pokes at live memory). E.g., for qOffsets |
| targets, or for PIE executables, until we connect and ask the |
| target for the final relocation offsets, the symbols we've used |
| to set breakpoints point at the wrong addresses. */ |
| int executing_startup = 0; |
| |
| /* True if no breakpoints should be inserted in this program |
| space. */ |
| int breakpoints_not_allowed = 0; |
| |
| /* The object file that the main symbol table was loaded from |
| (e.g. the argument to the "symbol-file" or "file" command). */ |
| struct objfile *symfile_object_file = NULL; |
| |
| /* All known objfiles are kept in a linked list. */ |
| std::list<std::shared_ptr<objfile>> objfiles_list; |
| |
| /* List of shared objects mapped into this space. Managed by |
| solib.c. */ |
| struct so_list *so_list = NULL; |
| |
| /* Number of calls to solib_add. */ |
| unsigned int solib_add_generation = 0; |
| |
| /* When an solib is added, it is also added to this vector. This |
| is so we can properly report solib changes to the user. */ |
| std::vector<struct so_list *> added_solibs; |
| |
| /* When an solib is removed, its name is added to this vector. |
| This is so we can properly report solib changes to the user. */ |
| std::vector<std::string> deleted_solibs; |
| |
| /* Per pspace data-pointers required by other GDB modules. */ |
| REGISTRY_FIELDS {}; |
| |
| private: |
| /* The set of target sections matching the sections mapped into |
| this program space. Managed by both exec_ops and solib.c. */ |
| target_section_table m_target_sections; |
| }; |
| |
| /* An address space. It is used for comparing if |
| pspaces/inferior/threads see the same address space and for |
| associating caches to each address space. */ |
| struct address_space |
| { |
| int num; |
| |
| /* Per aspace data-pointers required by other GDB modules. */ |
| REGISTRY_FIELDS; |
| }; |
| |
| /* The list of all program spaces. There's always at least one. */ |
| extern std::vector<struct program_space *>program_spaces; |
| |
| /* The current program space. This is always non-null. */ |
| extern struct program_space *current_program_space; |
| |
| /* Copies program space SRC to DEST. Copies the main executable file, |
| and the main symbol file. Returns DEST. */ |
| extern struct program_space *clone_program_space (struct program_space *dest, |
| struct program_space *src); |
| |
| /* Sets PSPACE as the current program space. This is usually used |
| instead of set_current_space_and_thread when the current |
| thread/inferior is not important for the operations that follow. |
| E.g., when accessing the raw symbol tables. If memory access is |
| required, then you should use switch_to_program_space_and_thread. |
| Otherwise, it is the caller's responsibility to make sure that the |
| currently selected inferior/thread matches the selected program |
| space. */ |
| extern void set_current_program_space (struct program_space *pspace); |
| |
| /* Save/restore the current program space. */ |
| |
| class scoped_restore_current_program_space |
| { |
| public: |
| scoped_restore_current_program_space () |
| : m_saved_pspace (current_program_space) |
| {} |
| |
| ~scoped_restore_current_program_space () |
| { set_current_program_space (m_saved_pspace); } |
| |
| DISABLE_COPY_AND_ASSIGN (scoped_restore_current_program_space); |
| |
| private: |
| program_space *m_saved_pspace; |
| }; |
| |
| /* Create a new address space object, and add it to the list. */ |
| extern struct address_space *new_address_space (void); |
| |
| /* Maybe create a new address space object, and add it to the list, or |
| return a pointer to an existing address space, in case inferiors |
| share an address space. */ |
| extern struct address_space *maybe_new_address_space (void); |
| |
| /* Returns the integer address space id of ASPACE. */ |
| extern int address_space_num (struct address_space *aspace); |
| |
| /* Update all program spaces matching to address spaces. The user may |
| have created several program spaces, and loaded executables into |
| them before connecting to the target interface that will create the |
| inferiors. All that happens before GDB has a chance to know if the |
| inferiors will share an address space or not. Call this after |
| having connected to the target interface and having fetched the |
| target description, to fixup the program/address spaces |
| mappings. */ |
| extern void update_address_spaces (void); |
| |
| /* Keep a registry of per-pspace data-pointers required by other GDB |
| modules. */ |
| |
| DECLARE_REGISTRY (program_space); |
| |
| /* Keep a registry of per-aspace data-pointers required by other GDB |
| modules. */ |
| |
| DECLARE_REGISTRY (address_space); |
| |
| #endif |