1 /* Shared library support for IRIX.
2 Copyright (C) 1993-2013 Free Software Foundation, Inc.
4 This file was created using portions of irix5-nat.c originally
5 contributed to GDB by Ian Lance Taylor.
7 This file is part of GDB.
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 3 of the License, or
12 (at your option) any later version.
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with this program. If not, see <http://www.gnu.org/licenses/>. */
26 /* FIXME: ezannoni/2004-02-13 Verify that the include below is
33 #include "gdbthread.h"
37 #include "solib-irix.h"
40 /* Link map info to include in an allocate so_list entry. Unlike some
41 of the other solib backends, this (Irix) backend chooses to decode
42 the link map info obtained from the target and store it as (mostly)
43 CORE_ADDRs which need no further decoding. This is more convenient
44 because there are three different link map formats to worry about.
45 We use a single routine (fetch_lm_info) to read (and decode) the target
46 specific link map data. */
50 CORE_ADDR addr; /* address of obj_info or obj_list
51 struct on target (from which the
52 following information is obtained). */
53 CORE_ADDR next; /* address of next item in list. */
54 CORE_ADDR reloc_offset; /* amount to relocate by */
55 CORE_ADDR pathname_addr; /* address of pathname */
56 int pathname_len; /* length of pathname */
59 /* It's not desirable to use the system header files to obtain the
60 structure of the obj_list or obj_info structs. Therefore, we use a
61 platform neutral representation which has been derived from the IRIX
75 /* The "old" obj_list struct. This is used with old (o32) binaries.
76 The ``data'' member points at a much larger and more complicated
77 struct which we will only refer to by offsets. See
87 /* The ELF32 and ELF64 versions of the above struct. The oi_magic value
88 corresponds to the ``data'' value in the "old" struct. When this value
89 is 0xffffffff, the data will be in one of the following formats. The
90 ``oi_size'' field is used to decide which one we actually have. */
92 struct irix_elf32_obj_info
94 gdb_int32_bytes oi_magic;
95 gdb_int32_bytes oi_size;
96 gdb_int32_bytes oi_next;
97 gdb_int32_bytes oi_prev;
98 gdb_int32_bytes oi_ehdr;
99 gdb_int32_bytes oi_orig_ehdr;
100 gdb_int32_bytes oi_pathname;
101 gdb_int32_bytes oi_pathname_len;
104 struct irix_elf64_obj_info
106 gdb_int32_bytes oi_magic;
107 gdb_int32_bytes oi_size;
108 gdb_int64_bytes oi_next;
109 gdb_int64_bytes oi_prev;
110 gdb_int64_bytes oi_ehdr;
111 gdb_int64_bytes oi_orig_ehdr;
112 gdb_int64_bytes oi_pathname;
113 gdb_int32_bytes oi_pathname_len;
114 gdb_int32_bytes padding;
117 /* Union of all of the above (plus a split out magic field). */
121 gdb_int32_bytes magic;
122 struct irix_obj_list ol32;
123 struct irix_elf32_obj_info oi32;
124 struct irix_elf64_obj_info oi64;
127 /* MIPS sign extends its 32 bit addresses. We could conceivably use
128 extract_typed_address here, but to do so, we'd have to construct an
129 appropriate type. Calling extract_signed_integer seems simpler. */
132 extract_mips_address (void *addr, int len, enum bfd_endian byte_order)
134 return extract_signed_integer (addr, len, byte_order);
137 /* Fetch and return the link map data associated with ADDR. Note that
138 this routine automatically determines which (of three) link map
139 formats is in use by the target. */
141 static struct lm_info
142 fetch_lm_info (CORE_ADDR addr)
144 enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ());
146 union irix_obj_info buf;
150 /* The smallest region that we'll need is for buf.ol32. We'll read
151 that first. We'll read more of the buffer later if we have to deal
152 with one of the other cases. (We don't want to incur a memory error
153 if we were to read a larger region that generates an error due to
154 being at the end of a page or the like.) */
155 read_memory (addr, (gdb_byte *) &buf, sizeof (buf.ol32));
157 if (extract_unsigned_integer (buf.magic.b, sizeof (buf.magic), byte_order)
160 /* Use buf.ol32... */
161 gdb_byte obj_buf[432];
162 CORE_ADDR obj_addr = extract_mips_address (&buf.ol32.data,
163 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 ((gdb_byte *) &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 ((gdb_byte *) &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. */
246 /* Locate the base address of dynamic linker structs.
248 For both the SunOS and SVR4 shared library implementations, if the
249 inferior executable has been linked dynamically, there is a single
250 address somewhere in the inferior's data space which is the key to
251 locating all of the dynamic linker's runtime structures. This
252 address is the value of the symbol defined by the macro DEBUG_BASE.
253 The job of this function is to find and return that address, or to
254 return 0 if there is no such address (the executable is statically
257 For SunOS, the job is almost trivial, since the dynamic linker and
258 all of it's structures are statically linked to the executable at
259 link time. Thus the symbol for the address we are looking for has
260 already been added to the minimal symbol table for the executable's
261 objfile at the time the symbol file's symbols were read, and all we
262 have to do is look it up there. Note that we explicitly do NOT want
263 to find the copies in the shared library.
265 The SVR4 version is much more complicated because the dynamic linker
266 and it's structures are located in the shared C library, which gets
267 run as the executable's "interpreter" by the kernel. We have to go
268 to a lot more work to discover the address of DEBUG_BASE. Because
269 of this complexity, we cache the value we find and return that value
270 on subsequent invocations. Note there is no copy in the executable
273 Irix 5 is basically like SunOS.
275 Note that we can assume nothing about the process state at the time
276 we need to find this address. We may be stopped on the first instruc-
277 tion of the interpreter (C shared library), the first instruction of
278 the executable itself, or somewhere else entirely (if we attached
279 to the process for example). */
284 struct minimal_symbol *msymbol;
285 CORE_ADDR address = 0;
287 msymbol = lookup_minimal_symbol (DEBUG_BASE, NULL, symfile_objfile);
288 if ((msymbol != NULL) && (SYMBOL_VALUE_ADDRESS (msymbol) != 0))
290 address = SYMBOL_VALUE_ADDRESS (msymbol);
295 /* Remove the "mapping changed" breakpoint.
297 Removes the breakpoint that gets hit when the dynamic linker
298 completes a mapping change. */
305 /* Note that breakpoint address and original contents are in our address
306 space, so we just need to write the original contents back. */
308 if (deprecated_remove_raw_breakpoint (target_gdbarch (), base_breakpoint) != 0)
313 base_breakpoint = NULL;
315 /* Note that it is possible that we have stopped at a location that
316 is different from the location where we inserted our breakpoint.
317 On mips-irix, we can actually land in __dbx_init(), so we should
318 not check the PC against our breakpoint address here. See procfs.c
324 /* Arrange for dynamic linker to hit breakpoint.
326 This functions inserts a breakpoint at the entry point of the
327 main executable, where all shared libraries are mapped in. */
332 if (symfile_objfile != NULL && has_stack_frames ())
334 struct frame_info *frame = get_current_frame ();
335 struct address_space *aspace = get_frame_address_space (frame);
336 CORE_ADDR entry_point;
338 if (!entry_point_address_query (&entry_point))
341 base_breakpoint = deprecated_insert_raw_breakpoint (target_gdbarch (),
342 aspace, entry_point);
344 if (base_breakpoint != NULL)
351 /* Implement the "create_inferior_hook" target_solib_ops method.
353 For SunOS executables, this first instruction is typically the
354 one at "_start", or a similar text label, regardless of whether
355 the executable is statically or dynamically linked. The runtime
356 startup code takes care of dynamically linking in any shared
357 libraries, once gdb allows the inferior to continue.
359 For SVR4 executables, this first instruction is either the first
360 instruction in the dynamic linker (for dynamically linked
361 executables) or the instruction at "start" for statically linked
362 executables. For dynamically linked executables, the system
363 first exec's /lib/libc.so.N, which contains the dynamic linker,
364 and starts it running. The dynamic linker maps in any needed
365 shared libraries, maps in the actual user executable, and then
366 jumps to "start" in the user executable.
368 For both SunOS shared libraries, and SVR4 shared libraries, we
369 can arrange to cooperate with the dynamic linker to discover the
370 names of shared libraries that are dynamically linked, and the
371 base addresses to which they are linked.
373 This function is responsible for discovering those names and
374 addresses, and saving sufficient information about them to allow
375 their symbols to be read at a later time.
379 Between enable_break() and disable_break(), this code does not
380 properly handle hitting breakpoints which the user might have
381 set in the startup code or in the dynamic linker itself. Proper
382 handling will probably have to wait until the implementation is
383 changed to use the "breakpoint handler function" method.
385 Also, what if child has exit()ed? Must exit loop somehow. */
388 irix_solib_create_inferior_hook (int from_tty)
390 struct inferior *inf;
391 struct thread_info *tp;
393 inf = current_inferior ();
395 /* If we are attaching to the inferior, the shared libraries
396 have already been mapped, so nothing more to do. */
397 if (inf->attach_flag)
400 /* Likewise when debugging from a core file, the shared libraries
401 have already been mapped, so nothing more to do. */
402 if (!target_can_run (¤t_target))
405 if (!enable_break ())
407 warning (_("shared library handler failed to enable breakpoint"));
411 /* Now run the target. It will eventually hit the breakpoint, at
412 which point all of the libraries will have been mapped in and we
413 can go groveling around in the dynamic linker structures to find
414 out what we need to know about them. */
416 tp = inferior_thread ();
418 clear_proceed_status ();
420 inf->control.stop_soon = STOP_QUIETLY;
421 tp->suspend.stop_signal = GDB_SIGNAL_0;
425 target_resume (pid_to_ptid (-1), 0, tp->suspend.stop_signal);
426 wait_for_inferior ();
428 while (tp->suspend.stop_signal != GDB_SIGNAL_TRAP);
430 /* We are now either at the "mapping complete" breakpoint (or somewhere
431 else, a condition we aren't prepared to deal with anyway), so adjust
432 the PC as necessary after a breakpoint, disable the breakpoint, and
433 add any shared libraries that were mapped in. */
435 if (!disable_break ())
437 warning (_("shared library handler failed to disable breakpoint"));
440 /* solib_add will call reinit_frame_cache.
441 But we are stopped in the startup code and we might not have symbols
442 for the startup code, so heuristic_proc_start could be called
443 and will put out an annoying warning.
444 Delaying the resetting of stop_soon until after symbol loading
445 suppresses the warning. */
446 solib_add ((char *) 0, 0, (struct target_ops *) 0, auto_solib_add);
447 inf->control.stop_soon = NO_STOP_QUIETLY;
450 /* Implement the "current_sos" target_so_ops method. */
452 static struct so_list *
453 irix_current_sos (void)
455 enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ());
456 int addr_size = gdbarch_addr_bit (target_gdbarch ()) / TARGET_CHAR_BIT;
458 gdb_byte addr_buf[8];
459 struct so_list *head = 0;
460 struct so_list **link_ptr = &head;
464 /* Make sure we've looked up the inferior's dynamic linker's base
468 debug_base = locate_base ();
470 /* If we can't find the dynamic linker's base structure, this
471 must not be a dynamically linked executable. Hmm. */
476 read_memory (debug_base, addr_buf, addr_size);
477 lma = extract_mips_address (addr_buf, addr_size, byte_order);
481 lm = fetch_lm_info (lma);
488 = (struct so_list *) xmalloc (sizeof (struct so_list));
489 struct cleanup *old_chain = make_cleanup (xfree, new);
491 memset (new, 0, sizeof (*new));
493 new->lm_info = xmalloc (sizeof (struct lm_info));
494 make_cleanup (xfree, new->lm_info);
498 /* Extract this shared object's name. */
499 name_size = lm.pathname_len;
501 name_size = SO_NAME_MAX_PATH_SIZE - 1;
503 if (name_size >= SO_NAME_MAX_PATH_SIZE)
505 name_size = SO_NAME_MAX_PATH_SIZE - 1;
506 warning (_("current_sos: truncating name of "
507 "%d characters to only %d characters"),
508 lm.pathname_len, name_size);
511 target_read_string (lm.pathname_addr, &name_buf,
512 name_size, &errcode);
514 warning (_("Can't read pathname for load map: %s."),
515 safe_strerror (errcode));
518 strncpy (new->so_name, name_buf, name_size);
519 new->so_name[name_size] = '\0';
521 strcpy (new->so_original_name, new->so_name);
526 link_ptr = &new->next;
528 discard_cleanups (old_chain);
537 /* Implement the "open_symbol_file_object" target_so_ops method.
539 If no open symbol file, attempt to locate and open the main symbol
540 file. On IRIX, this is the first link map entry. If its name is
541 here, we can open it. Useful when attaching to a process without
542 first loading its symbol file. */
545 irix_open_symbol_file_object (void *from_ttyp)
547 enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ());
548 int addr_size = gdbarch_addr_bit (target_gdbarch ()) / TARGET_CHAR_BIT;
550 gdb_byte addr_buf[8];
552 struct cleanup *cleanups;
554 int from_tty = *(int *) from_ttyp;
558 if (!query (_("Attempt to reload symbols from process? ")))
561 if ((debug_base = locate_base ()) == 0)
562 return 0; /* failed somehow... */
564 /* First link map member should be the executable. */
565 read_memory (debug_base, addr_buf, addr_size);
566 lma = extract_mips_address (addr_buf, addr_size, byte_order);
568 return 0; /* failed somehow... */
570 lm = fetch_lm_info (lma);
572 if (lm.pathname_addr == 0)
573 return 0; /* No filename. */
575 /* Now fetch the filename from target memory. */
576 target_read_string (lm.pathname_addr, &filename, SO_NAME_MAX_PATH_SIZE - 1,
581 warning (_("failed to read exec filename from attached file: %s"),
582 safe_strerror (errcode));
586 cleanups = make_cleanup (xfree, filename);
587 /* Have a pathname: read the symbol file. */
588 symbol_file_add_main (filename, from_tty);
590 do_cleanups (cleanups);
595 /* Implement the "special_symbol_handling" target_so_ops method.
597 For IRIX, there's nothing to do. */
600 irix_special_symbol_handling (void)
604 /* Using the solist entry SO, relocate the addresses in SEC. */
607 irix_relocate_section_addresses (struct so_list *so,
608 struct target_section *sec)
610 sec->addr += so->lm_info->reloc_offset;
611 sec->endaddr += so->lm_info->reloc_offset;
614 /* Free the lm_info struct. */
617 irix_free_so (struct so_list *so)
622 /* Clear backend specific state. */
625 irix_clear_solib (void)
630 /* Return 1 if PC lies in the dynamic symbol resolution code of the
633 irix_in_dynsym_resolve_code (CORE_ADDR pc)
638 struct target_so_ops irix_so_ops;
640 /* Provide a prototype to silence -Wmissing-prototypes. */
641 extern initialize_file_ftype _initialize_irix_solib;
644 _initialize_irix_solib (void)
646 irix_so_ops.relocate_section_addresses = irix_relocate_section_addresses;
647 irix_so_ops.free_so = irix_free_so;
648 irix_so_ops.clear_solib = irix_clear_solib;
649 irix_so_ops.solib_create_inferior_hook = irix_solib_create_inferior_hook;
650 irix_so_ops.special_symbol_handling = irix_special_symbol_handling;
651 irix_so_ops.current_sos = irix_current_sos;
652 irix_so_ops.open_symbol_file_object = irix_open_symbol_file_object;
653 irix_so_ops.in_dynsym_resolve_code = irix_in_dynsym_resolve_code;
654 irix_so_ops.bfd_open = solib_bfd_open;