1 /* Shared library support for IRIX.
2 Copyright (C) 1993, 1994, 1995, 1996, 1998, 1999, 2000, 2001, 2002, 2004,
3 2007, 2008, 2009 Free Software Foundation, Inc.
5 This file was created using portions of irix5-nat.c originally
6 contributed to GDB by Ian Lance Taylor.
8 This file is part of GDB.
10 This program is free software; you can redistribute it and/or modify
11 it under the terms of the GNU General Public License as published by
12 the Free Software Foundation; either version 3 of the License, or
13 (at your option) any later version.
15 This program is distributed in the hope that it will be useful,
16 but WITHOUT ANY WARRANTY; without even the implied warranty of
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 GNU General Public License for more details.
20 You should have received a copy of the GNU General Public License
21 along with this program. If not, see <http://www.gnu.org/licenses/>. */
27 /* FIXME: ezannoni/2004-02-13 Verify that the include below is
34 #include "gdbthread.h"
38 #include "solib-irix.h"
41 /* Link map info to include in an allocate so_list entry. Unlike some
42 of the other solib backends, this (Irix) backend chooses to decode
43 the link map info obtained from the target and store it as (mostly)
44 CORE_ADDRs which need no further decoding. This is more convenient
45 because there are three different link map formats to worry about.
46 We use a single routine (fetch_lm_info) to read (and decode) the target
47 specific link map data. */
51 CORE_ADDR addr
; /* address of obj_info or obj_list
52 struct on target (from which the
53 following information is obtained). */
54 CORE_ADDR next
; /* address of next item in list. */
55 CORE_ADDR reloc_offset
; /* amount to relocate by */
56 CORE_ADDR pathname_addr
; /* address of pathname */
57 int pathname_len
; /* length of pathname */
60 /* It's not desirable to use the system header files to obtain the
61 structure of the obj_list or obj_info structs. Therefore, we use a
62 platform neutral representation which has been derived from the IRIX
76 /* The "old" obj_list struct. This is used with old (o32) binaries.
77 The ``data'' member points at a much larger and more complicated
78 struct which we will only refer to by offsets. See
88 /* The ELF32 and ELF64 versions of the above struct. The oi_magic value
89 corresponds to the ``data'' value in the "old" struct. When this value
90 is 0xffffffff, the data will be in one of the following formats. The
91 ``oi_size'' field is used to decide which one we actually have. */
93 struct irix_elf32_obj_info
95 gdb_int32_bytes oi_magic
;
96 gdb_int32_bytes oi_size
;
97 gdb_int32_bytes oi_next
;
98 gdb_int32_bytes oi_prev
;
99 gdb_int32_bytes oi_ehdr
;
100 gdb_int32_bytes oi_orig_ehdr
;
101 gdb_int32_bytes oi_pathname
;
102 gdb_int32_bytes oi_pathname_len
;
105 struct irix_elf64_obj_info
107 gdb_int32_bytes oi_magic
;
108 gdb_int32_bytes oi_size
;
109 gdb_int64_bytes oi_next
;
110 gdb_int64_bytes oi_prev
;
111 gdb_int64_bytes oi_ehdr
;
112 gdb_int64_bytes oi_orig_ehdr
;
113 gdb_int64_bytes oi_pathname
;
114 gdb_int32_bytes oi_pathname_len
;
115 gdb_int32_bytes padding
;
118 /* Union of all of the above (plus a split out magic field). */
122 gdb_int32_bytes magic
;
123 struct irix_obj_list ol32
;
124 struct irix_elf32_obj_info oi32
;
125 struct irix_elf64_obj_info oi64
;
128 /* MIPS sign extends its 32 bit addresses. We could conceivably use
129 extract_typed_address here, but to do so, we'd have to construct an
130 appropriate type. Calling extract_signed_integer seems simpler. */
133 extract_mips_address (void *addr
, int len
, enum bfd_endian byte_order
)
135 return extract_signed_integer (addr
, len
, byte_order
);
138 /* Fetch and return the link map data associated with ADDR. Note that
139 this routine automatically determines which (of three) link map
140 formats is in use by the target. */
142 static struct lm_info
143 fetch_lm_info (CORE_ADDR addr
)
145 enum bfd_endian byte_order
= gdbarch_byte_order (target_gdbarch
);
147 union irix_obj_info buf
;
151 /* The smallest region that we'll need is for buf.ol32. We'll read
152 that first. We'll read more of the buffer later if we have to deal
153 with one of the other cases. (We don't want to incur a memory error
154 if we were to read a larger region that generates an error due to
155 being at the end of a page or the like.) */
156 read_memory (addr
, (char *) &buf
, sizeof (buf
.ol32
));
158 if (extract_unsigned_integer (buf
.magic
.b
, sizeof (buf
.magic
), byte_order
)
161 /* Use buf.ol32... */
163 CORE_ADDR obj_addr
= extract_mips_address (&buf
.ol32
.data
,
164 sizeof (buf
.ol32
.data
),
166 li
.next
= extract_mips_address (&buf
.ol32
.next
,
167 sizeof (buf
.ol32
.next
), byte_order
);
169 read_memory (obj_addr
, obj_buf
, sizeof (obj_buf
));
171 li
.pathname_addr
= extract_mips_address (&obj_buf
[236], 4, byte_order
);
172 li
.pathname_len
= 0; /* unknown */
173 li
.reloc_offset
= extract_mips_address (&obj_buf
[196], 4, byte_order
)
174 - extract_mips_address (&obj_buf
[248], 4, byte_order
);
177 else if (extract_unsigned_integer (buf
.oi32
.oi_size
.b
,
178 sizeof (buf
.oi32
.oi_size
), byte_order
)
179 == sizeof (buf
.oi32
))
181 /* Use buf.oi32... */
183 /* Read rest of buffer. */
184 read_memory (addr
+ sizeof (buf
.ol32
),
185 ((char *) &buf
) + sizeof (buf
.ol32
),
186 sizeof (buf
.oi32
) - sizeof (buf
.ol32
));
188 /* Fill in fields using buffer contents. */
189 li
.next
= extract_mips_address (&buf
.oi32
.oi_next
,
190 sizeof (buf
.oi32
.oi_next
), byte_order
);
191 li
.reloc_offset
= extract_mips_address (&buf
.oi32
.oi_ehdr
,
192 sizeof (buf
.oi32
.oi_ehdr
),
194 - extract_mips_address (&buf
.oi32
.oi_orig_ehdr
,
195 sizeof (buf
.oi32
.oi_orig_ehdr
), byte_order
);
196 li
.pathname_addr
= extract_mips_address (&buf
.oi32
.oi_pathname
,
197 sizeof (buf
.oi32
.oi_pathname
),
199 li
.pathname_len
= extract_unsigned_integer (buf
.oi32
.oi_pathname_len
.b
,
204 else if (extract_unsigned_integer (buf
.oi64
.oi_size
.b
,
205 sizeof (buf
.oi64
.oi_size
), byte_order
)
206 == sizeof (buf
.oi64
))
208 /* Use buf.oi64... */
210 /* Read rest of buffer. */
211 read_memory (addr
+ sizeof (buf
.ol32
),
212 ((char *) &buf
) + sizeof (buf
.ol32
),
213 sizeof (buf
.oi64
) - sizeof (buf
.ol32
));
215 /* Fill in fields using buffer contents. */
216 li
.next
= extract_mips_address (&buf
.oi64
.oi_next
,
217 sizeof (buf
.oi64
.oi_next
), byte_order
);
218 li
.reloc_offset
= extract_mips_address (&buf
.oi64
.oi_ehdr
,
219 sizeof (buf
.oi64
.oi_ehdr
),
221 - extract_mips_address (&buf
.oi64
.oi_orig_ehdr
,
222 sizeof (buf
.oi64
.oi_orig_ehdr
), byte_order
);
223 li
.pathname_addr
= extract_mips_address (&buf
.oi64
.oi_pathname
,
224 sizeof (buf
.oi64
.oi_pathname
),
226 li
.pathname_len
= extract_unsigned_integer (buf
.oi64
.oi_pathname_len
.b
,
233 error (_("Unable to fetch shared library obj_info or obj_list info."));
239 /* The symbol which starts off the list of shared libraries. */
240 #define DEBUG_BASE "__rld_obj_head"
242 static void *base_breakpoint
;
244 static CORE_ADDR debug_base
; /* Base of dynamic linker structures */
250 locate_base -- locate the base address of dynamic linker structs
254 CORE_ADDR locate_base (void)
258 For both the SunOS and SVR4 shared library implementations, if the
259 inferior executable has been linked dynamically, there is a single
260 address somewhere in the inferior's data space which is the key to
261 locating all of the dynamic linker's runtime structures. This
262 address is the value of the symbol defined by the macro DEBUG_BASE.
263 The job of this function is to find and return that address, or to
264 return 0 if there is no such address (the executable is statically
267 For SunOS, the job is almost trivial, since the dynamic linker and
268 all of it's structures are statically linked to the executable at
269 link time. Thus the symbol for the address we are looking for has
270 already been added to the minimal symbol table for the executable's
271 objfile at the time the symbol file's symbols were read, and all we
272 have to do is look it up there. Note that we explicitly do NOT want
273 to find the copies in the shared library.
275 The SVR4 version is much more complicated because the dynamic linker
276 and it's structures are located in the shared C library, which gets
277 run as the executable's "interpreter" by the kernel. We have to go
278 to a lot more work to discover the address of DEBUG_BASE. Because
279 of this complexity, we cache the value we find and return that value
280 on subsequent invocations. Note there is no copy in the executable
283 Irix 5 is basically like SunOS.
285 Note that we can assume nothing about the process state at the time
286 we need to find this address. We may be stopped on the first instruc-
287 tion of the interpreter (C shared library), the first instruction of
288 the executable itself, or somewhere else entirely (if we attached
289 to the process for example).
296 struct minimal_symbol
*msymbol
;
297 CORE_ADDR address
= 0;
299 msymbol
= lookup_minimal_symbol (DEBUG_BASE
, NULL
, symfile_objfile
);
300 if ((msymbol
!= NULL
) && (SYMBOL_VALUE_ADDRESS (msymbol
) != 0))
302 address
= SYMBOL_VALUE_ADDRESS (msymbol
);
311 disable_break -- remove the "mapping changed" breakpoint
315 static int disable_break ()
319 Removes the breakpoint that gets hit when the dynamic linker
320 completes a mapping change.
330 /* Note that breakpoint address and original contents are in our address
331 space, so we just need to write the original contents back. */
333 if (deprecated_remove_raw_breakpoint (target_gdbarch
, base_breakpoint
) != 0)
338 base_breakpoint
= NULL
;
340 /* Note that it is possible that we have stopped at a location that
341 is different from the location where we inserted our breakpoint.
342 On mips-irix, we can actually land in __dbx_init(), so we should
343 not check the PC against our breakpoint address here. See procfs.c
353 enable_break -- arrange for dynamic linker to hit breakpoint
357 int enable_break (void)
361 This functions inserts a breakpoint at the entry point of the
362 main executable, where all shared libraries are mapped in.
368 if (symfile_objfile
!= NULL
&& has_stack_frames ())
370 struct frame_info
*frame
= get_current_frame ();
371 struct address_space
*aspace
= get_frame_address_space (frame
);
374 = deprecated_insert_raw_breakpoint (target_gdbarch
,
376 entry_point_address ());
378 if (base_breakpoint
!= NULL
)
389 irix_solib_create_inferior_hook -- shared library startup support
393 void solib_create_inferior_hook ()
397 When gdb starts up the inferior, it nurses it along (through the
398 shell) until it is ready to execute it's first instruction. At this
399 point, this function gets called via expansion of the macro
400 SOLIB_CREATE_INFERIOR_HOOK.
402 For SunOS executables, this first instruction is typically the
403 one at "_start", or a similar text label, regardless of whether
404 the executable is statically or dynamically linked. The runtime
405 startup code takes care of dynamically linking in any shared
406 libraries, once gdb allows the inferior to continue.
408 For SVR4 executables, this first instruction is either the first
409 instruction in the dynamic linker (for dynamically linked
410 executables) or the instruction at "start" for statically linked
411 executables. For dynamically linked executables, the system
412 first exec's /lib/libc.so.N, which contains the dynamic linker,
413 and starts it running. The dynamic linker maps in any needed
414 shared libraries, maps in the actual user executable, and then
415 jumps to "start" in the user executable.
417 For both SunOS shared libraries, and SVR4 shared libraries, we
418 can arrange to cooperate with the dynamic linker to discover the
419 names of shared libraries that are dynamically linked, and the
420 base addresses to which they are linked.
422 This function is responsible for discovering those names and
423 addresses, and saving sufficient information about them to allow
424 their symbols to be read at a later time.
428 Between enable_break() and disable_break(), this code does not
429 properly handle hitting breakpoints which the user might have
430 set in the startup code or in the dynamic linker itself. Proper
431 handling will probably have to wait until the implementation is
432 changed to use the "breakpoint handler function" method.
434 Also, what if child has exit()ed? Must exit loop somehow.
438 irix_solib_create_inferior_hook (void)
440 struct inferior
*inf
;
441 struct thread_info
*tp
;
443 if (!enable_break ())
445 warning (_("shared library handler failed to enable breakpoint"));
449 /* Now run the target. It will eventually hit the breakpoint, at
450 which point all of the libraries will have been mapped in and we
451 can go groveling around in the dynamic linker structures to find
452 out what we need to know about them. */
454 inf
= current_inferior ();
455 tp
= inferior_thread ();
457 clear_proceed_status ();
459 inf
->stop_soon
= STOP_QUIETLY
;
460 tp
->stop_signal
= TARGET_SIGNAL_0
;
464 target_resume (pid_to_ptid (-1), 0, tp
->stop_signal
);
465 wait_for_inferior (0);
467 while (tp
->stop_signal
!= TARGET_SIGNAL_TRAP
);
469 /* We are now either at the "mapping complete" breakpoint (or somewhere
470 else, a condition we aren't prepared to deal with anyway), so adjust
471 the PC as necessary after a breakpoint, disable the breakpoint, and
472 add any shared libraries that were mapped in. */
474 if (!disable_break ())
476 warning (_("shared library handler failed to disable breakpoint"));
479 /* solib_add will call reinit_frame_cache.
480 But we are stopped in the startup code and we might not have symbols
481 for the startup code, so heuristic_proc_start could be called
482 and will put out an annoying warning.
483 Delaying the resetting of stop_soon until after symbol loading
484 suppresses the warning. */
485 solib_add ((char *) 0, 0, (struct target_ops
*) 0, auto_solib_add
);
486 inf
->stop_soon
= NO_STOP_QUIETLY
;
491 current_sos -- build a list of currently loaded shared objects
495 struct so_list *current_sos ()
499 Build a list of `struct so_list' objects describing the shared
500 objects currently loaded in the inferior. This list does not
501 include an entry for the main executable file.
503 Note that we only gather information directly available from the
504 inferior --- we don't examine any of the shared library files
505 themselves. The declaration of `struct so_list' says which fields
506 we provide values for. */
508 static struct so_list
*
509 irix_current_sos (void)
511 enum bfd_endian byte_order
= gdbarch_byte_order (target_gdbarch
);
512 int addr_size
= gdbarch_addr_bit (target_gdbarch
) / TARGET_CHAR_BIT
;
515 struct so_list
*head
= 0;
516 struct so_list
**link_ptr
= &head
;
520 /* Make sure we've looked up the inferior's dynamic linker's base
524 debug_base
= locate_base ();
526 /* If we can't find the dynamic linker's base structure, this
527 must not be a dynamically linked executable. Hmm. */
532 read_memory (debug_base
, addr_buf
, addr_size
);
533 lma
= extract_mips_address (addr_buf
, addr_size
, byte_order
);
537 lm
= fetch_lm_info (lma
);
544 = (struct so_list
*) xmalloc (sizeof (struct so_list
));
545 struct cleanup
*old_chain
= make_cleanup (xfree
, new);
547 memset (new, 0, sizeof (*new));
549 new->lm_info
= xmalloc (sizeof (struct lm_info
));
550 make_cleanup (xfree
, new->lm_info
);
554 /* Extract this shared object's name. */
555 name_size
= lm
.pathname_len
;
557 name_size
= SO_NAME_MAX_PATH_SIZE
- 1;
559 if (name_size
>= SO_NAME_MAX_PATH_SIZE
)
561 name_size
= SO_NAME_MAX_PATH_SIZE
- 1;
563 ("current_sos: truncating name of %d characters to only %d characters",
564 lm
.pathname_len
, name_size
);
567 target_read_string (lm
.pathname_addr
, &name_buf
,
568 name_size
, &errcode
);
570 warning (_("Can't read pathname for load map: %s."),
571 safe_strerror (errcode
));
574 strncpy (new->so_name
, name_buf
, name_size
);
575 new->so_name
[name_size
] = '\0';
577 strcpy (new->so_original_name
, new->so_name
);
582 link_ptr
= &new->next
;
584 discard_cleanups (old_chain
);
597 irix_open_symbol_file_object
601 void irix_open_symbol_file_object (void *from_tty)
605 If no open symbol file, attempt to locate and open the main symbol
606 file. On IRIX, this is the first link map entry. If its name is
607 here, we can open it. Useful when attaching to a process without
608 first loading its symbol file.
610 If FROM_TTYP dereferences to a non-zero integer, allow messages to
611 be printed. This parameter is a pointer rather than an int because
612 open_symbol_file_object() is called via catch_errors() and
613 catch_errors() requires a pointer argument. */
616 irix_open_symbol_file_object (void *from_ttyp
)
618 enum bfd_endian byte_order
= gdbarch_byte_order (target_gdbarch
);
619 int addr_size
= gdbarch_addr_bit (target_gdbarch
) / TARGET_CHAR_BIT
;
623 struct cleanup
*cleanups
;
625 int from_tty
= *(int *) from_ttyp
;
629 if (!query (_("Attempt to reload symbols from process? ")))
632 if ((debug_base
= locate_base ()) == 0)
633 return 0; /* failed somehow... */
635 /* First link map member should be the executable. */
636 read_memory (debug_base
, addr_buf
, addr_size
);
637 lma
= extract_mips_address (addr_buf
, addr_size
, byte_order
);
639 return 0; /* failed somehow... */
641 lm
= fetch_lm_info (lma
);
643 if (lm
.pathname_addr
== 0)
644 return 0; /* No filename. */
646 /* Now fetch the filename from target memory. */
647 target_read_string (lm
.pathname_addr
, &filename
, SO_NAME_MAX_PATH_SIZE
- 1,
652 warning (_("failed to read exec filename from attached file: %s"),
653 safe_strerror (errcode
));
657 cleanups
= make_cleanup (xfree
, filename
);
658 /* Have a pathname: read the symbol file. */
659 symbol_file_add_main (filename
, from_tty
);
661 do_cleanups (cleanups
);
671 irix_special_symbol_handling -- additional shared library symbol handling
675 void irix_special_symbol_handling ()
679 Once the symbols from a shared object have been loaded in the usual
680 way, we are called to do any system specific symbol handling that
683 For SunOS4, this consisted of grunging around in the dynamic
684 linkers structures to find symbol definitions for "common" symbols
685 and adding them to the minimal symbol table for the runtime common
688 However, for IRIX, there's nothing to do.
693 irix_special_symbol_handling (void)
697 /* Using the solist entry SO, relocate the addresses in SEC. */
700 irix_relocate_section_addresses (struct so_list
*so
,
701 struct target_section
*sec
)
703 sec
->addr
+= so
->lm_info
->reloc_offset
;
704 sec
->endaddr
+= so
->lm_info
->reloc_offset
;
707 /* Free the lm_info struct. */
710 irix_free_so (struct so_list
*so
)
715 /* Clear backend specific state. */
718 irix_clear_solib (void)
723 /* Return 1 if PC lies in the dynamic symbol resolution code of the
726 irix_in_dynsym_resolve_code (CORE_ADDR pc
)
731 struct target_so_ops irix_so_ops
;
733 /* Provide a prototype to silence -Wmissing-prototypes. */
734 extern initialize_file_ftype _initialize_irix_solib
;
737 _initialize_irix_solib (void)
739 irix_so_ops
.relocate_section_addresses
= irix_relocate_section_addresses
;
740 irix_so_ops
.free_so
= irix_free_so
;
741 irix_so_ops
.clear_solib
= irix_clear_solib
;
742 irix_so_ops
.solib_create_inferior_hook
= irix_solib_create_inferior_hook
;
743 irix_so_ops
.special_symbol_handling
= irix_special_symbol_handling
;
744 irix_so_ops
.current_sos
= irix_current_sos
;
745 irix_so_ops
.open_symbol_file_object
= irix_open_symbol_file_object
;
746 irix_so_ops
.in_dynsym_resolve_code
= irix_in_dynsym_resolve_code
;
747 irix_so_ops
.bfd_open
= solib_bfd_open
;