1 /* Core dump and executable file functions below target vector, for GDB.
3 Copyright (C) 1986-2020 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/>. */
21 #include "arch-utils.h"
24 #include "frame.h" /* required by inferior.h */
31 #include "process-stratum-target.h"
33 #include "gdbthread.h"
38 #include "readline/tilde.h"
40 #include "filenames.h"
41 #include "progspace.h"
44 #include "completer.h"
45 #include "gdbsupport/filestuff.h"
47 #include "gdbsupport/pathstuff.h"
53 /* The core file target. */
55 static const target_info core_target_info
= {
57 N_("Local core dump file"),
58 N_("Use a core file as a target.\n\
59 Specify the filename of the core file.")
62 class core_target final
: public process_stratum_target
66 ~core_target () override
;
68 const target_info
&info () const override
69 { return core_target_info
; }
71 void close () override
;
72 void detach (inferior
*, int) override
;
73 void fetch_registers (struct regcache
*, int) override
;
75 enum target_xfer_status
xfer_partial (enum target_object object
,
78 const gdb_byte
*writebuf
,
79 ULONGEST offset
, ULONGEST len
,
80 ULONGEST
*xfered_len
) override
;
81 void files_info () override
;
83 bool thread_alive (ptid_t ptid
) override
;
84 const struct target_desc
*read_description () override
;
86 std::string
pid_to_str (ptid_t
) override
;
88 const char *thread_name (struct thread_info
*) override
;
90 bool has_all_memory () override
{ return false; }
91 bool has_memory () override
;
92 bool has_stack () override
;
93 bool has_registers () override
;
94 bool has_execution (inferior
*inf
) override
{ return false; }
96 bool info_proc (const char *, enum info_proc_what
) override
;
100 /* Getter, see variable definition. */
101 struct gdbarch
*core_gdbarch ()
103 return m_core_gdbarch
;
106 /* See definition. */
107 void get_core_register_section (struct regcache
*regcache
,
108 const struct regset
*regset
,
110 int section_min_size
,
111 const char *human_name
,
114 private: /* per-core data */
116 /* The core's section table. Note that these target sections are
117 *not* mapped in the current address spaces' set of target
118 sections --- those should come only from pure executable or
119 shared library bfds. The core bfd sections are an implementation
120 detail of the core target, just like ptrace is for unix child
122 target_section_table m_core_section_table
{};
124 /* FIXME: kettenis/20031023: Eventually this field should
126 struct gdbarch
*m_core_gdbarch
= NULL
;
129 core_target::core_target ()
131 m_core_gdbarch
= gdbarch_from_bfd (core_bfd
);
134 || !gdbarch_iterate_over_regset_sections_p (m_core_gdbarch
))
135 error (_("\"%s\": Core file format not supported"),
136 bfd_get_filename (core_bfd
));
138 /* Find the data section */
139 if (build_section_table (core_bfd
,
140 &m_core_section_table
.sections
,
141 &m_core_section_table
.sections_end
))
142 error (_("\"%s\": Can't find sections: %s"),
143 bfd_get_filename (core_bfd
), bfd_errmsg (bfd_get_error ()));
146 core_target::~core_target ()
148 xfree (m_core_section_table
.sections
);
151 static void add_to_thread_list (bfd
*, asection
*, void *);
153 /* An arbitrary identifier for the core inferior. */
154 #define CORELOW_PID 1
156 /* Close the core target. */
159 core_target::close ()
163 switch_to_no_thread (); /* Avoid confusion from thread
165 exit_inferior_silent (current_inferior ());
167 /* Clear out solib state while the bfd is still open. See
168 comments in clear_solib in solib.c. */
171 current_program_space
->cbfd
.reset (nullptr);
174 /* Core targets are heap-allocated (see core_target_open), so here
175 we delete ourselves. */
179 /* Look for sections whose names start with `.reg/' so that we can
180 extract the list of threads in a core file. */
183 add_to_thread_list (bfd
*abfd
, asection
*asect
, void *reg_sect_arg
)
187 asection
*reg_sect
= (asection
*) reg_sect_arg
;
188 bool fake_pid_p
= false;
189 struct inferior
*inf
;
191 if (!startswith (bfd_section_name (asect
), ".reg/"))
194 core_tid
= atoi (bfd_section_name (asect
) + 5);
196 pid
= bfd_core_file_pid (core_bfd
);
205 inf
= current_inferior ();
208 inferior_appeared (inf
, pid
);
209 inf
->fake_pid_p
= fake_pid_p
;
212 ptid_t
ptid (pid
, lwpid
);
214 thread_info
*thr
= add_thread (inf
->process_target (), ptid
);
216 /* Warning, Will Robinson, looking at BFD private data! */
219 && asect
->filepos
== reg_sect
->filepos
) /* Did we find .reg? */
220 switch_to_thread (thr
); /* Yes, make it current. */
223 /* Issue a message saying we have no core to debug, if FROM_TTY. */
226 maybe_say_no_core_file_now (int from_tty
)
229 printf_filtered (_("No core file now.\n"));
232 /* Backward compatibility with old way of specifying core files. */
235 core_file_command (const char *filename
, int from_tty
)
237 dont_repeat (); /* Either way, seems bogus. */
239 if (filename
== NULL
)
241 if (core_bfd
!= NULL
)
243 target_detach (current_inferior (), from_tty
);
244 gdb_assert (core_bfd
== NULL
);
247 maybe_say_no_core_file_now (from_tty
);
250 core_target_open (filename
, from_tty
);
253 /* Locate (and load) an executable file (and symbols) given the core file
257 locate_exec_from_corefile_build_id (bfd
*abfd
, int from_tty
)
259 const bfd_build_id
*build_id
= build_id_bfd_get (abfd
);
260 if (build_id
== nullptr)
263 gdb_bfd_ref_ptr execbfd
264 = build_id_to_exec_bfd (build_id
->size
, build_id
->data
);
266 if (execbfd
!= nullptr)
268 exec_file_attach (bfd_get_filename (execbfd
.get ()), from_tty
);
269 symbol_file_add_main (bfd_get_filename (execbfd
.get ()),
270 symfile_add_flag (from_tty
? SYMFILE_VERBOSE
: 0));
277 core_target_open (const char *arg
, int from_tty
)
284 target_preopen (from_tty
);
288 error (_("No core file specified. (Use `detach' "
289 "to stop debugging a core file.)"));
291 error (_("No core file specified."));
294 gdb::unique_xmalloc_ptr
<char> filename (tilde_expand (arg
));
295 if (!IS_ABSOLUTE_PATH (filename
.get ()))
296 filename
= gdb_abspath (filename
.get ());
298 flags
= O_BINARY
| O_LARGEFILE
;
303 scratch_chan
= gdb_open_cloexec (filename
.get (), flags
, 0);
304 if (scratch_chan
< 0)
305 perror_with_name (filename
.get ());
307 gdb_bfd_ref_ptr
temp_bfd (gdb_bfd_fopen (filename
.get (), gnutarget
,
308 write_files
? FOPEN_RUB
: FOPEN_RB
,
310 if (temp_bfd
== NULL
)
311 perror_with_name (filename
.get ());
313 if (!bfd_check_format (temp_bfd
.get (), bfd_core
))
315 /* Do it after the err msg */
316 /* FIXME: should be checking for errors from bfd_close (for one
317 thing, on error it does not free all the storage associated
319 error (_("\"%s\" is not a core dump: %s"),
320 filename
.get (), bfd_errmsg (bfd_get_error ()));
323 current_program_space
->cbfd
= std::move (temp_bfd
);
325 core_target
*target
= new core_target ();
327 /* Own the target until it is successfully pushed. */
328 target_ops_up
target_holder (target
);
332 /* If we have no exec file, try to set the architecture from the
333 core file. We don't do this unconditionally since an exec file
334 typically contains more information that helps us determine the
335 architecture than a core file. */
337 set_gdbarch_from_file (core_bfd
);
339 push_target (std::move (target_holder
));
341 switch_to_no_thread ();
343 /* Need to flush the register cache (and the frame cache) from a
344 previous debug session. If inferior_ptid ends up the same as the
345 last debug session --- e.g., b foo; run; gcore core1; step; gcore
346 core2; core core1; core core2 --- then there's potential for
347 get_current_regcache to return the cached regcache of the
348 previous session, and the frame cache being stale. */
349 registers_changed ();
351 /* Build up thread list from BFD sections, and possibly set the
352 current thread to the .reg/NN section matching the .reg
354 bfd_map_over_sections (core_bfd
, add_to_thread_list
,
355 bfd_get_section_by_name (core_bfd
, ".reg"));
357 if (inferior_ptid
== null_ptid
)
359 /* Either we found no .reg/NN section, and hence we have a
360 non-threaded core (single-threaded, from gdb's perspective),
361 or for some reason add_to_thread_list couldn't determine
362 which was the "main" thread. The latter case shouldn't
363 usually happen, but we're dealing with input here, which can
364 always be broken in different ways. */
365 thread_info
*thread
= first_thread_of_inferior (current_inferior ());
369 inferior_appeared (current_inferior (), CORELOW_PID
);
370 thread
= add_thread_silent (target
, ptid_t (CORELOW_PID
));
373 switch_to_thread (thread
);
376 if (exec_bfd
== nullptr)
377 locate_exec_from_corefile_build_id (core_bfd
, from_tty
);
379 post_create_inferior (target
, from_tty
);
381 /* Now go through the target stack looking for threads since there
382 may be a thread_stratum target loaded on top of target core by
383 now. The layer above should claim threads found in the BFD
387 target_update_thread_list ();
390 catch (const gdb_exception_error
&except
)
392 exception_print (gdb_stderr
, except
);
395 p
= bfd_core_file_failing_command (core_bfd
);
397 printf_filtered (_("Core was generated by `%s'.\n"), p
);
399 /* Clearing any previous state of convenience variables. */
400 clear_exit_convenience_vars ();
402 siggy
= bfd_core_file_failing_signal (core_bfd
);
405 gdbarch
*core_gdbarch
= target
->core_gdbarch ();
407 /* If we don't have a CORE_GDBARCH to work with, assume a native
408 core (map gdb_signal from host signals). If we do have
409 CORE_GDBARCH to work with, but no gdb_signal_from_target
410 implementation for that gdbarch, as a fallback measure,
411 assume the host signal mapping. It'll be correct for native
412 cores, but most likely incorrect for cross-cores. */
413 enum gdb_signal sig
= (core_gdbarch
!= NULL
414 && gdbarch_gdb_signal_from_target_p (core_gdbarch
)
415 ? gdbarch_gdb_signal_from_target (core_gdbarch
,
417 : gdb_signal_from_host (siggy
));
419 printf_filtered (_("Program terminated with signal %s, %s.\n"),
420 gdb_signal_to_name (sig
), gdb_signal_to_string (sig
));
422 /* Set the value of the internal variable $_exitsignal,
423 which holds the signal uncaught by the inferior. */
424 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
428 /* Fetch all registers from core file. */
429 target_fetch_registers (get_current_regcache (), -1);
431 /* Now, set up the frame cache, and print the top of stack. */
432 reinit_frame_cache ();
433 print_stack_frame (get_selected_frame (NULL
), 1, SRC_AND_LOC
, 1);
435 /* Current thread should be NUM 1 but the user does not know that.
436 If a program is single threaded gdb in general does not mention
437 anything about threads. That is why the test is >= 2. */
438 if (thread_count (target
) >= 2)
442 thread_command (NULL
, from_tty
);
444 catch (const gdb_exception_error
&except
)
446 exception_print (gdb_stderr
, except
);
452 core_target::detach (inferior
*inf
, int from_tty
)
454 /* Note that 'this' is dangling after this call. unpush_target
455 closes the target, and our close implementation deletes
457 unpush_target (this);
459 /* Clear the register cache and the frame cache. */
460 registers_changed ();
461 reinit_frame_cache ();
462 maybe_say_no_core_file_now (from_tty
);
465 /* Try to retrieve registers from a section in core_bfd, and supply
468 If ptid's lwp member is zero, do the single-threaded
469 thing: look for a section named NAME. If ptid's lwp
470 member is non-zero, do the multi-threaded thing: look for a section
471 named "NAME/LWP", where LWP is the shortest ASCII decimal
472 representation of ptid's lwp member.
474 HUMAN_NAME is a human-readable name for the kind of registers the
475 NAME section contains, for use in error messages.
477 If REQUIRED is true, print an error if the core file doesn't have a
478 section by the appropriate name. Otherwise, just do nothing. */
481 core_target::get_core_register_section (struct regcache
*regcache
,
482 const struct regset
*regset
,
484 int section_min_size
,
485 const char *human_name
,
488 gdb_assert (regset
!= nullptr);
490 struct bfd_section
*section
;
492 bool variable_size_section
= (regset
->flags
& REGSET_VARIABLE_SIZE
);
494 thread_section_name
section_name (name
, regcache
->ptid ());
496 section
= bfd_get_section_by_name (core_bfd
, section_name
.c_str ());
500 warning (_("Couldn't find %s registers in core file."),
505 size
= bfd_section_size (section
);
506 if (size
< section_min_size
)
508 warning (_("Section `%s' in core file too small."),
509 section_name
.c_str ());
512 if (size
!= section_min_size
&& !variable_size_section
)
514 warning (_("Unexpected size of section `%s' in core file."),
515 section_name
.c_str ());
518 gdb::byte_vector
contents (size
);
519 if (!bfd_get_section_contents (core_bfd
, section
, contents
.data (),
522 warning (_("Couldn't read %s registers from `%s' section in core file."),
523 human_name
, section_name
.c_str ());
527 regset
->supply_regset (regset
, regcache
, -1, contents
.data (), size
);
530 /* Data passed to gdbarch_iterate_over_regset_sections's callback. */
531 struct get_core_registers_cb_data
534 struct regcache
*regcache
;
537 /* Callback for get_core_registers that handles a single core file
538 register note section. */
541 get_core_registers_cb (const char *sect_name
, int supply_size
, int collect_size
,
542 const struct regset
*regset
,
543 const char *human_name
, void *cb_data
)
545 gdb_assert (regset
!= nullptr);
547 auto *data
= (get_core_registers_cb_data
*) cb_data
;
548 bool required
= false;
549 bool variable_size_section
= (regset
->flags
& REGSET_VARIABLE_SIZE
);
551 if (!variable_size_section
)
552 gdb_assert (supply_size
== collect_size
);
554 if (strcmp (sect_name
, ".reg") == 0)
557 if (human_name
== NULL
)
558 human_name
= "general-purpose";
560 else if (strcmp (sect_name
, ".reg2") == 0)
562 if (human_name
== NULL
)
563 human_name
= "floating-point";
566 data
->target
->get_core_register_section (data
->regcache
, regset
, sect_name
,
567 supply_size
, human_name
, required
);
570 /* Get the registers out of a core file. This is the machine-
571 independent part. Fetch_core_registers is the machine-dependent
572 part, typically implemented in the xm-file for each
575 /* We just get all the registers, so we don't use regno. */
578 core_target::fetch_registers (struct regcache
*regcache
, int regno
)
580 if (!(m_core_gdbarch
!= nullptr
581 && gdbarch_iterate_over_regset_sections_p (m_core_gdbarch
)))
583 fprintf_filtered (gdb_stderr
,
584 "Can't fetch registers from this type of core file\n");
588 struct gdbarch
*gdbarch
= regcache
->arch ();
589 get_core_registers_cb_data data
= { this, regcache
};
590 gdbarch_iterate_over_regset_sections (gdbarch
,
591 get_core_registers_cb
,
592 (void *) &data
, NULL
);
594 /* Mark all registers not found in the core as unavailable. */
595 for (int i
= 0; i
< gdbarch_num_regs (regcache
->arch ()); i
++)
596 if (regcache
->get_register_status (i
) == REG_UNKNOWN
)
597 regcache
->raw_supply (i
, NULL
);
601 core_target::files_info ()
603 print_section_info (&m_core_section_table
, core_bfd
);
606 enum target_xfer_status
607 core_target::xfer_partial (enum target_object object
, const char *annex
,
608 gdb_byte
*readbuf
, const gdb_byte
*writebuf
,
609 ULONGEST offset
, ULONGEST len
, ULONGEST
*xfered_len
)
613 case TARGET_OBJECT_MEMORY
:
614 return (section_table_xfer_memory_partial
616 offset
, len
, xfered_len
,
617 m_core_section_table
.sections
,
618 m_core_section_table
.sections_end
,
621 case TARGET_OBJECT_AUXV
:
624 /* When the aux vector is stored in core file, BFD
625 represents this with a fake section called ".auxv". */
627 struct bfd_section
*section
;
630 section
= bfd_get_section_by_name (core_bfd
, ".auxv");
632 return TARGET_XFER_E_IO
;
634 size
= bfd_section_size (section
);
636 return TARGET_XFER_EOF
;
642 return TARGET_XFER_EOF
;
643 if (!bfd_get_section_contents (core_bfd
, section
, readbuf
,
644 (file_ptr
) offset
, size
))
646 warning (_("Couldn't read NT_AUXV note in core file."));
647 return TARGET_XFER_E_IO
;
650 *xfered_len
= (ULONGEST
) size
;
651 return TARGET_XFER_OK
;
653 return TARGET_XFER_E_IO
;
655 case TARGET_OBJECT_WCOOKIE
:
658 /* When the StackGhost cookie is stored in core file, BFD
659 represents this with a fake section called
662 struct bfd_section
*section
;
665 section
= bfd_get_section_by_name (core_bfd
, ".wcookie");
667 return TARGET_XFER_E_IO
;
669 size
= bfd_section_size (section
);
671 return TARGET_XFER_EOF
;
677 return TARGET_XFER_EOF
;
678 if (!bfd_get_section_contents (core_bfd
, section
, readbuf
,
679 (file_ptr
) offset
, size
))
681 warning (_("Couldn't read StackGhost cookie in core file."));
682 return TARGET_XFER_E_IO
;
685 *xfered_len
= (ULONGEST
) size
;
686 return TARGET_XFER_OK
;
689 return TARGET_XFER_E_IO
;
691 case TARGET_OBJECT_LIBRARIES
:
692 if (m_core_gdbarch
!= nullptr
693 && gdbarch_core_xfer_shared_libraries_p (m_core_gdbarch
))
696 return TARGET_XFER_E_IO
;
699 *xfered_len
= gdbarch_core_xfer_shared_libraries (m_core_gdbarch
,
703 if (*xfered_len
== 0)
704 return TARGET_XFER_EOF
;
706 return TARGET_XFER_OK
;
711 case TARGET_OBJECT_LIBRARIES_AIX
:
712 if (m_core_gdbarch
!= nullptr
713 && gdbarch_core_xfer_shared_libraries_aix_p (m_core_gdbarch
))
716 return TARGET_XFER_E_IO
;
720 = gdbarch_core_xfer_shared_libraries_aix (m_core_gdbarch
,
724 if (*xfered_len
== 0)
725 return TARGET_XFER_EOF
;
727 return TARGET_XFER_OK
;
732 case TARGET_OBJECT_SIGNAL_INFO
:
735 if (m_core_gdbarch
!= nullptr
736 && gdbarch_core_xfer_siginfo_p (m_core_gdbarch
))
738 LONGEST l
= gdbarch_core_xfer_siginfo (m_core_gdbarch
, readbuf
,
745 return TARGET_XFER_EOF
;
747 return TARGET_XFER_OK
;
751 return TARGET_XFER_E_IO
;
754 return this->beneath ()->xfer_partial (object
, annex
, readbuf
,
755 writebuf
, offset
, len
,
762 /* Okay, let's be honest: threads gleaned from a core file aren't
763 exactly lively, are they? On the other hand, if we don't claim
764 that each & every one is alive, then we don't get any of them
765 to appear in an "info thread" command, which is quite a useful
769 core_target::thread_alive (ptid_t ptid
)
774 /* Ask the current architecture what it knows about this core file.
775 That will be used, in turn, to pick a better architecture. This
776 wrapper could be avoided if targets got a chance to specialize
779 const struct target_desc
*
780 core_target::read_description ()
782 if (m_core_gdbarch
&& gdbarch_core_read_description_p (m_core_gdbarch
))
784 const struct target_desc
*result
;
786 result
= gdbarch_core_read_description (m_core_gdbarch
, this, core_bfd
);
791 return this->beneath ()->read_description ();
795 core_target::pid_to_str (ptid_t ptid
)
797 struct inferior
*inf
;
800 /* The preferred way is to have a gdbarch/OS specific
802 if (m_core_gdbarch
!= nullptr
803 && gdbarch_core_pid_to_str_p (m_core_gdbarch
))
804 return gdbarch_core_pid_to_str (m_core_gdbarch
, ptid
);
806 /* Otherwise, if we don't have one, we'll just fallback to
807 "process", with normal_pid_to_str. */
809 /* Try the LWPID field first. */
812 return normal_pid_to_str (ptid_t (pid
));
814 /* Otherwise, this isn't a "threaded" core -- use the PID field, but
815 only if it isn't a fake PID. */
816 inf
= find_inferior_ptid (this, ptid
);
817 if (inf
!= NULL
&& !inf
->fake_pid_p
)
818 return normal_pid_to_str (ptid
);
820 /* No luck. We simply don't have a valid PID to print. */
821 return "<main task>";
825 core_target::thread_name (struct thread_info
*thr
)
827 if (m_core_gdbarch
!= nullptr
828 && gdbarch_core_thread_name_p (m_core_gdbarch
))
829 return gdbarch_core_thread_name (m_core_gdbarch
, thr
);
834 core_target::has_memory ()
836 return (core_bfd
!= NULL
);
840 core_target::has_stack ()
842 return (core_bfd
!= NULL
);
846 core_target::has_registers ()
848 return (core_bfd
!= NULL
);
851 /* Implement the to_info_proc method. */
854 core_target::info_proc (const char *args
, enum info_proc_what request
)
856 struct gdbarch
*gdbarch
= get_current_arch ();
858 /* Since this is the core file target, call the 'core_info_proc'
859 method on gdbarch, not 'info_proc'. */
860 if (gdbarch_core_info_proc_p (gdbarch
))
861 gdbarch_core_info_proc (gdbarch
, args
, request
);
866 void _initialize_corelow ();
868 _initialize_corelow ()
870 add_target (core_target_info
, core_target_open
, filename_completer
);