1 /* Shared library support for IRIX.
2 Copyright (C) 1993, 1994, 1995, 1996, 1998, 1999, 2000, 2001, 2002, 2004,
3 2007, 2008, 2009, 2010, 2011 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),
167 li.next = extract_mips_address (&buf.ol32.next,
168 sizeof (buf.ol32.next), byte_order);
170 read_memory (obj_addr, obj_buf, sizeof (obj_buf));
172 li.pathname_addr = extract_mips_address (&obj_buf[236], 4, byte_order);
173 li.pathname_len = 0; /* unknown */
174 li.reloc_offset = extract_mips_address (&obj_buf[196], 4, byte_order)
175 - extract_mips_address (&obj_buf[248], 4, byte_order);
178 else if (extract_unsigned_integer (buf.oi32.oi_size.b,
179 sizeof (buf.oi32.oi_size), byte_order)
180 == sizeof (buf.oi32))
182 /* Use buf.oi32... */
184 /* Read rest of buffer. */
185 read_memory (addr + sizeof (buf.ol32),
186 ((char *) &buf) + sizeof (buf.ol32),
187 sizeof (buf.oi32) - sizeof (buf.ol32));
189 /* Fill in fields using buffer contents. */
190 li.next = extract_mips_address (&buf.oi32.oi_next,
191 sizeof (buf.oi32.oi_next), byte_order);
192 li.reloc_offset = extract_mips_address (&buf.oi32.oi_ehdr,
193 sizeof (buf.oi32.oi_ehdr),
195 - extract_mips_address (&buf.oi32.oi_orig_ehdr,
196 sizeof (buf.oi32.oi_orig_ehdr), byte_order);
197 li.pathname_addr = extract_mips_address (&buf.oi32.oi_pathname,
198 sizeof (buf.oi32.oi_pathname),
200 li.pathname_len = extract_unsigned_integer (buf.oi32.oi_pathname_len.b,
205 else if (extract_unsigned_integer (buf.oi64.oi_size.b,
206 sizeof (buf.oi64.oi_size), byte_order)
207 == sizeof (buf.oi64))
209 /* Use buf.oi64... */
211 /* Read rest of buffer. */
212 read_memory (addr + sizeof (buf.ol32),
213 ((char *) &buf) + sizeof (buf.ol32),
214 sizeof (buf.oi64) - sizeof (buf.ol32));
216 /* Fill in fields using buffer contents. */
217 li.next = extract_mips_address (&buf.oi64.oi_next,
218 sizeof (buf.oi64.oi_next), byte_order);
219 li.reloc_offset = extract_mips_address (&buf.oi64.oi_ehdr,
220 sizeof (buf.oi64.oi_ehdr),
222 - extract_mips_address (&buf.oi64.oi_orig_ehdr,
223 sizeof (buf.oi64.oi_orig_ehdr), byte_order);
224 li.pathname_addr = extract_mips_address (&buf.oi64.oi_pathname,
225 sizeof (buf.oi64.oi_pathname),
227 li.pathname_len = extract_unsigned_integer (buf.oi64.oi_pathname_len.b,
234 error (_("Unable to fetch shared library obj_info or obj_list info."));
240 /* The symbol which starts off the list of shared libraries. */
241 #define DEBUG_BASE "__rld_obj_head"
243 static void *base_breakpoint;
245 static CORE_ADDR debug_base; /* Base of dynamic linker structures. */
247 /* Locate the base address of dynamic linker structs.
249 For both the SunOS and SVR4 shared library implementations, if the
250 inferior executable has been linked dynamically, there is a single
251 address somewhere in the inferior's data space which is the key to
252 locating all of the dynamic linker's runtime structures. This
253 address is the value of the symbol defined by the macro DEBUG_BASE.
254 The job of this function is to find and return that address, or to
255 return 0 if there is no such address (the executable is statically
258 For SunOS, the job is almost trivial, since the dynamic linker and
259 all of it's structures are statically linked to the executable at
260 link time. Thus the symbol for the address we are looking for has
261 already been added to the minimal symbol table for the executable's
262 objfile at the time the symbol file's symbols were read, and all we
263 have to do is look it up there. Note that we explicitly do NOT want
264 to find the copies in the shared library.
266 The SVR4 version is much more complicated because the dynamic linker
267 and it's structures are located in the shared C library, which gets
268 run as the executable's "interpreter" by the kernel. We have to go
269 to a lot more work to discover the address of DEBUG_BASE. Because
270 of this complexity, we cache the value we find and return that value
271 on subsequent invocations. Note there is no copy in the executable
274 Irix 5 is basically like SunOS.
276 Note that we can assume nothing about the process state at the time
277 we need to find this address. We may be stopped on the first instruc-
278 tion of the interpreter (C shared library), the first instruction of
279 the executable itself, or somewhere else entirely (if we attached
280 to the process for example). */
285 struct minimal_symbol *msymbol;
286 CORE_ADDR address = 0;
288 msymbol = lookup_minimal_symbol (DEBUG_BASE, NULL, symfile_objfile);
289 if ((msymbol != NULL) && (SYMBOL_VALUE_ADDRESS (msymbol) != 0))
291 address = SYMBOL_VALUE_ADDRESS (msymbol);
296 /* Remove the "mapping changed" breakpoint.
298 Removes the breakpoint that gets hit when the dynamic linker
299 completes a mapping change. */
306 /* Note that breakpoint address and original contents are in our address
307 space, so we just need to write the original contents back. */
309 if (deprecated_remove_raw_breakpoint (target_gdbarch, base_breakpoint) != 0)
314 base_breakpoint = NULL;
316 /* Note that it is possible that we have stopped at a location that
317 is different from the location where we inserted our breakpoint.
318 On mips-irix, we can actually land in __dbx_init(), so we should
319 not check the PC against our breakpoint address here. See procfs.c
325 /* Arrange for dynamic linker to hit breakpoint.
327 This functions inserts a breakpoint at the entry point of the
328 main executable, where all shared libraries are mapped in. */
333 if (symfile_objfile != NULL && has_stack_frames ())
335 struct frame_info *frame = get_current_frame ();
336 struct address_space *aspace = get_frame_address_space (frame);
337 CORE_ADDR entry_point;
339 if (!entry_point_address_query (&entry_point))
342 base_breakpoint = deprecated_insert_raw_breakpoint (target_gdbarch,
343 aspace, entry_point);
345 if (base_breakpoint != NULL)
352 /* Implement the "create_inferior_hook" target_solib_ops method.
354 For SunOS executables, this first instruction is typically the
355 one at "_start", or a similar text label, regardless of whether
356 the executable is statically or dynamically linked. The runtime
357 startup code takes care of dynamically linking in any shared
358 libraries, once gdb allows the inferior to continue.
360 For SVR4 executables, this first instruction is either the first
361 instruction in the dynamic linker (for dynamically linked
362 executables) or the instruction at "start" for statically linked
363 executables. For dynamically linked executables, the system
364 first exec's /lib/libc.so.N, which contains the dynamic linker,
365 and starts it running. The dynamic linker maps in any needed
366 shared libraries, maps in the actual user executable, and then
367 jumps to "start" in the user executable.
369 For both SunOS shared libraries, and SVR4 shared libraries, we
370 can arrange to cooperate with the dynamic linker to discover the
371 names of shared libraries that are dynamically linked, and the
372 base addresses to which they are linked.
374 This function is responsible for discovering those names and
375 addresses, and saving sufficient information about them to allow
376 their symbols to be read at a later time.
380 Between enable_break() and disable_break(), this code does not
381 properly handle hitting breakpoints which the user might have
382 set in the startup code or in the dynamic linker itself. Proper
383 handling will probably have to wait until the implementation is
384 changed to use the "breakpoint handler function" method.
386 Also, what if child has exit()ed? Must exit loop somehow. */
389 irix_solib_create_inferior_hook (int from_tty)
391 struct inferior *inf;
392 struct thread_info *tp;
394 inf = current_inferior ();
396 /* If we are attaching to the inferior, the shared libraries
397 have already been mapped, so nothing more to do. */
398 if (inf->attach_flag)
401 /* Likewise when debugging from a core file, the shared libraries
402 have already been mapped, so nothing more to do. */
403 if (!target_can_run (¤t_target))
406 if (!enable_break ())
408 warning (_("shared library handler failed to enable breakpoint"));
412 /* Now run the target. It will eventually hit the breakpoint, at
413 which point all of the libraries will have been mapped in and we
414 can go groveling around in the dynamic linker structures to find
415 out what we need to know about them. */
417 tp = inferior_thread ();
419 clear_proceed_status ();
421 inf->control.stop_soon = STOP_QUIETLY;
422 tp->suspend.stop_signal = TARGET_SIGNAL_0;
426 target_resume (pid_to_ptid (-1), 0, tp->suspend.stop_signal);
427 wait_for_inferior ();
429 while (tp->suspend.stop_signal != TARGET_SIGNAL_TRAP);
431 /* We are now either at the "mapping complete" breakpoint (or somewhere
432 else, a condition we aren't prepared to deal with anyway), so adjust
433 the PC as necessary after a breakpoint, disable the breakpoint, and
434 add any shared libraries that were mapped in. */
436 if (!disable_break ())
438 warning (_("shared library handler failed to disable breakpoint"));
441 /* solib_add will call reinit_frame_cache.
442 But we are stopped in the startup code and we might not have symbols
443 for the startup code, so heuristic_proc_start could be called
444 and will put out an annoying warning.
445 Delaying the resetting of stop_soon until after symbol loading
446 suppresses the warning. */
447 solib_add ((char *) 0, 0, (struct target_ops *) 0, auto_solib_add);
448 inf->control.stop_soon = NO_STOP_QUIETLY;
451 /* Implement the "current_sos" target_so_ops method. */
453 static struct so_list *
454 irix_current_sos (void)
456 enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch);
457 int addr_size = gdbarch_addr_bit (target_gdbarch) / TARGET_CHAR_BIT;
460 struct so_list *head = 0;
461 struct so_list **link_ptr = &head;
465 /* Make sure we've looked up the inferior's dynamic linker's base
469 debug_base = locate_base ();
471 /* If we can't find the dynamic linker's base structure, this
472 must not be a dynamically linked executable. Hmm. */
477 read_memory (debug_base, addr_buf, addr_size);
478 lma = extract_mips_address (addr_buf, addr_size, byte_order);
482 lm = fetch_lm_info (lma);
489 = (struct so_list *) xmalloc (sizeof (struct so_list));
490 struct cleanup *old_chain = make_cleanup (xfree, new);
492 memset (new, 0, sizeof (*new));
494 new->lm_info = xmalloc (sizeof (struct lm_info));
495 make_cleanup (xfree, new->lm_info);
499 /* Extract this shared object's name. */
500 name_size = lm.pathname_len;
502 name_size = SO_NAME_MAX_PATH_SIZE - 1;
504 if (name_size >= SO_NAME_MAX_PATH_SIZE)
506 name_size = SO_NAME_MAX_PATH_SIZE - 1;
507 warning (_("current_sos: truncating name of "
508 "%d characters to only %d characters"),
509 lm.pathname_len, name_size);
512 target_read_string (lm.pathname_addr, &name_buf,
513 name_size, &errcode);
515 warning (_("Can't read pathname for load map: %s."),
516 safe_strerror (errcode));
519 strncpy (new->so_name, name_buf, name_size);
520 new->so_name[name_size] = '\0';
522 strcpy (new->so_original_name, new->so_name);
527 link_ptr = &new->next;
529 discard_cleanups (old_chain);
538 /* Implement the "open_symbol_file_object" target_so_ops method.
540 If no open symbol file, attempt to locate and open the main symbol
541 file. On IRIX, this is the first link map entry. If its name is
542 here, we can open it. Useful when attaching to a process without
543 first loading its symbol file. */
546 irix_open_symbol_file_object (void *from_ttyp)
548 enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch);
549 int addr_size = gdbarch_addr_bit (target_gdbarch) / TARGET_CHAR_BIT;
553 struct cleanup *cleanups;
555 int from_tty = *(int *) from_ttyp;
559 if (!query (_("Attempt to reload symbols from process? ")))
562 if ((debug_base = locate_base ()) == 0)
563 return 0; /* failed somehow... */
565 /* First link map member should be the executable. */
566 read_memory (debug_base, addr_buf, addr_size);
567 lma = extract_mips_address (addr_buf, addr_size, byte_order);
569 return 0; /* failed somehow... */
571 lm = fetch_lm_info (lma);
573 if (lm.pathname_addr == 0)
574 return 0; /* No filename. */
576 /* Now fetch the filename from target memory. */
577 target_read_string (lm.pathname_addr, &filename, SO_NAME_MAX_PATH_SIZE - 1,
582 warning (_("failed to read exec filename from attached file: %s"),
583 safe_strerror (errcode));
587 cleanups = make_cleanup (xfree, filename);
588 /* Have a pathname: read the symbol file. */
589 symbol_file_add_main (filename, from_tty);
591 do_cleanups (cleanups);
596 /* Implement the "special_symbol_handling" target_so_ops method.
598 For IRIX, there's nothing to do. */
601 irix_special_symbol_handling (void)
605 /* Using the solist entry SO, relocate the addresses in SEC. */
608 irix_relocate_section_addresses (struct so_list *so,
609 struct target_section *sec)
611 sec->addr += so->lm_info->reloc_offset;
612 sec->endaddr += so->lm_info->reloc_offset;
615 /* Free the lm_info struct. */
618 irix_free_so (struct so_list *so)
623 /* Clear backend specific state. */
626 irix_clear_solib (void)
631 /* Return 1 if PC lies in the dynamic symbol resolution code of the
634 irix_in_dynsym_resolve_code (CORE_ADDR pc)
639 struct target_so_ops irix_so_ops;
641 /* Provide a prototype to silence -Wmissing-prototypes. */
642 extern initialize_file_ftype _initialize_irix_solib;
645 _initialize_irix_solib (void)
647 irix_so_ops.relocate_section_addresses = irix_relocate_section_addresses;
648 irix_so_ops.free_so = irix_free_so;
649 irix_so_ops.clear_solib = irix_clear_solib;
650 irix_so_ops.solib_create_inferior_hook = irix_solib_create_inferior_hook;
651 irix_so_ops.special_symbol_handling = irix_special_symbol_handling;
652 irix_so_ops.current_sos = irix_current_sos;
653 irix_so_ops.open_symbol_file_object = irix_open_symbol_file_object;
654 irix_so_ops.in_dynsym_resolve_code = irix_in_dynsym_resolve_code;
655 irix_so_ops.bfd_open = solib_bfd_open;