1 /* Shared library support for IRIX.
2 Copyright (C) 1993-2014 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
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, (gdb_byte *) &buf, sizeof (buf.ol32));
158 if (extract_unsigned_integer (buf.magic.b, sizeof (buf.magic), byte_order)
161 /* Use buf.ol32... */
162 gdb_byte obj_buf[432];
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 ((gdb_byte *) &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 ((gdb_byte *) &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 CORE_ADDR debug_base; /* Base of dynamic linker structures. */
245 /* Locate the base address of dynamic linker structs.
247 For both the SunOS and SVR4 shared library implementations, if the
248 inferior executable has been linked dynamically, there is a single
249 address somewhere in the inferior's data space which is the key to
250 locating all of the dynamic linker's runtime structures. This
251 address is the value of the symbol defined by the macro DEBUG_BASE.
252 The job of this function is to find and return that address, or to
253 return 0 if there is no such address (the executable is statically
256 For SunOS, the job is almost trivial, since the dynamic linker and
257 all of it's structures are statically linked to the executable at
258 link time. Thus the symbol for the address we are looking for has
259 already been added to the minimal symbol table for the executable's
260 objfile at the time the symbol file's symbols were read, and all we
261 have to do is look it up there. Note that we explicitly do NOT want
262 to find the copies in the shared library.
264 The SVR4 version is much more complicated because the dynamic linker
265 and it's structures are located in the shared C library, which gets
266 run as the executable's "interpreter" by the kernel. We have to go
267 to a lot more work to discover the address of DEBUG_BASE. Because
268 of this complexity, we cache the value we find and return that value
269 on subsequent invocations. Note there is no copy in the executable
272 Irix 5 is basically like SunOS.
274 Note that we can assume nothing about the process state at the time
275 we need to find this address. We may be stopped on the first instruc-
276 tion of the interpreter (C shared library), the first instruction of
277 the executable itself, or somewhere else entirely (if we attached
278 to the process for example). */
283 struct bound_minimal_symbol msymbol;
284 CORE_ADDR address = 0;
286 msymbol = lookup_minimal_symbol (DEBUG_BASE, NULL, symfile_objfile);
287 if ((msymbol.minsym != NULL) && (BMSYMBOL_VALUE_ADDRESS (msymbol) != 0))
289 address = BMSYMBOL_VALUE_ADDRESS (msymbol);
295 /* Arrange for dynamic linker to hit breakpoint.
297 This functions inserts a breakpoint at the entry point of the
298 main executable, where all shared libraries are mapped in. */
303 if (symfile_objfile != NULL && has_stack_frames ())
305 CORE_ADDR entry_point;
307 if (entry_point_address_query (&entry_point))
309 create_solib_event_breakpoint (target_gdbarch (), entry_point);
317 /* Implement the "handle_event" target_solib_ops method. */
320 irix_solib_handle_event (void)
322 /* We are now at the "mapping complete" breakpoint, we no longer
323 need it. Note that it is possible that we have stopped at a
324 location that is different from the location where we inserted
325 our breakpoint: On mips-irix, we can actually land in
326 __dbx_link(), so we should not check the PC against our
327 breakpoint address here. See procfs.c for more details. Note
328 we're being called by the bpstat handling code, and so can't
329 delete the breakpoint immediately. Mark it for later deletion,
330 which has the same effect (it'll be removed before we next resume
331 or if we're stopping). */
332 remove_solib_event_breakpoints_at_next_stop ();
334 /* The caller calls solib_add, which will add any shared libraries
335 that were mapped in. */
338 /* Implement the "create_inferior_hook" target_solib_ops method.
340 For SunOS executables, this first instruction is typically the
341 one at "_start", or a similar text label, regardless of whether
342 the executable is statically or dynamically linked. The runtime
343 startup code takes care of dynamically linking in any shared
344 libraries, once gdb allows the inferior to continue.
346 For SVR4 executables, this first instruction is either the first
347 instruction in the dynamic linker (for dynamically linked
348 executables) or the instruction at "start" for statically linked
349 executables. For dynamically linked executables, the system
350 first exec's /lib/libc.so.N, which contains the dynamic linker,
351 and starts it running. The dynamic linker maps in any needed
352 shared libraries, maps in the actual user executable, and then
353 jumps to "start" in the user executable.
355 For both SunOS shared libraries, and SVR4 shared libraries, we
356 can arrange to cooperate with the dynamic linker to discover the
357 names of shared libraries that are dynamically linked, and the
358 base addresses to which they are linked.
360 This function is responsible for discovering those names and
361 addresses, and saving sufficient information about them to allow
362 their symbols to be read at a later time.
366 Between enable_break() and disable_break(), this code does not
367 properly handle hitting breakpoints which the user might have
368 set in the startup code or in the dynamic linker itself. Proper
369 handling will probably have to wait until the implementation is
370 changed to use the "breakpoint handler function" method.
372 Also, what if child has exit()ed? Must exit loop somehow. */
375 irix_solib_create_inferior_hook (int from_tty)
377 struct inferior *inf;
378 struct thread_info *tp;
380 inf = current_inferior ();
382 /* If we are attaching to the inferior, the shared libraries
383 have already been mapped, so nothing more to do. */
384 if (inf->attach_flag)
387 /* Likewise when debugging from a core file, the shared libraries
388 have already been mapped, so nothing more to do. */
389 if (!target_can_run (¤t_target))
392 if (!enable_break ())
394 warning (_("shared library handler failed to enable breakpoint"));
398 /* The target will eventually hit the breakpoint, at which point all
399 of the libraries will have been mapped in and we can go groveling
400 around in the dynamic linker structures to find out what we need
401 to know about them. */
404 /* Implement the "current_sos" target_so_ops method. */
406 static struct so_list *
407 irix_current_sos (void)
409 enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ());
410 int addr_size = gdbarch_addr_bit (target_gdbarch ()) / TARGET_CHAR_BIT;
412 gdb_byte addr_buf[8];
413 struct so_list *head = 0;
414 struct so_list **link_ptr = &head;
418 /* Make sure we've looked up the inferior's dynamic linker's base
422 debug_base = locate_base ();
424 /* If we can't find the dynamic linker's base structure, this
425 must not be a dynamically linked executable. Hmm. */
430 read_memory (debug_base, addr_buf, addr_size);
431 lma = extract_mips_address (addr_buf, addr_size, byte_order);
435 lm = fetch_lm_info (lma);
442 = (struct so_list *) xmalloc (sizeof (struct so_list));
443 struct cleanup *old_chain = make_cleanup (xfree, new);
445 memset (new, 0, sizeof (*new));
447 new->lm_info = xmalloc (sizeof (struct lm_info));
448 make_cleanup (xfree, new->lm_info);
452 /* Extract this shared object's name. */
453 name_size = lm.pathname_len;
455 name_size = SO_NAME_MAX_PATH_SIZE - 1;
457 if (name_size >= SO_NAME_MAX_PATH_SIZE)
459 name_size = SO_NAME_MAX_PATH_SIZE - 1;
460 warning (_("current_sos: truncating name of "
461 "%d characters to only %d characters"),
462 lm.pathname_len, name_size);
465 target_read_string (lm.pathname_addr, &name_buf,
466 name_size, &errcode);
468 warning (_("Can't read pathname for load map: %s."),
469 safe_strerror (errcode));
472 strncpy (new->so_name, name_buf, name_size);
473 new->so_name[name_size] = '\0';
475 strcpy (new->so_original_name, new->so_name);
480 link_ptr = &new->next;
482 discard_cleanups (old_chain);
491 /* Implement the "open_symbol_file_object" target_so_ops method.
493 If no open symbol file, attempt to locate and open the main symbol
494 file. On IRIX, this is the first link map entry. If its name is
495 here, we can open it. Useful when attaching to a process without
496 first loading its symbol file. */
499 irix_open_symbol_file_object (void *from_ttyp)
501 enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ());
502 int addr_size = gdbarch_addr_bit (target_gdbarch ()) / TARGET_CHAR_BIT;
504 gdb_byte addr_buf[8];
506 struct cleanup *cleanups;
508 int from_tty = *(int *) from_ttyp;
512 if (!query (_("Attempt to reload symbols from process? ")))
515 if ((debug_base = locate_base ()) == 0)
516 return 0; /* failed somehow... */
518 /* First link map member should be the executable. */
519 read_memory (debug_base, addr_buf, addr_size);
520 lma = extract_mips_address (addr_buf, addr_size, byte_order);
522 return 0; /* failed somehow... */
524 lm = fetch_lm_info (lma);
526 if (lm.pathname_addr == 0)
527 return 0; /* No filename. */
529 /* Now fetch the filename from target memory. */
530 target_read_string (lm.pathname_addr, &filename, SO_NAME_MAX_PATH_SIZE - 1,
535 warning (_("failed to read exec filename from attached file: %s"),
536 safe_strerror (errcode));
540 cleanups = make_cleanup (xfree, filename);
541 /* Have a pathname: read the symbol file. */
542 symbol_file_add_main (filename, from_tty);
544 do_cleanups (cleanups);
549 /* Implement the "special_symbol_handling" target_so_ops method.
551 For IRIX, there's nothing to do. */
554 irix_special_symbol_handling (void)
558 /* Using the solist entry SO, relocate the addresses in SEC. */
561 irix_relocate_section_addresses (struct so_list *so,
562 struct target_section *sec)
564 sec->addr += so->lm_info->reloc_offset;
565 sec->endaddr += so->lm_info->reloc_offset;
568 /* Free the lm_info struct. */
571 irix_free_so (struct so_list *so)
576 /* Clear backend specific state. */
579 irix_clear_solib (void)
584 /* Return 1 if PC lies in the dynamic symbol resolution code of the
587 irix_in_dynsym_resolve_code (CORE_ADDR pc)
592 struct target_so_ops irix_so_ops;
594 /* Provide a prototype to silence -Wmissing-prototypes. */
595 extern initialize_file_ftype _initialize_irix_solib;
598 _initialize_irix_solib (void)
600 irix_so_ops.relocate_section_addresses = irix_relocate_section_addresses;
601 irix_so_ops.free_so = irix_free_so;
602 irix_so_ops.clear_solib = irix_clear_solib;
603 irix_so_ops.solib_create_inferior_hook = irix_solib_create_inferior_hook;
604 irix_so_ops.special_symbol_handling = irix_special_symbol_handling;
605 irix_so_ops.current_sos = irix_current_sos;
606 irix_so_ops.open_symbol_file_object = irix_open_symbol_file_object;
607 irix_so_ops.in_dynsym_resolve_code = irix_in_dynsym_resolve_code;
608 irix_so_ops.bfd_open = solib_bfd_open;
609 irix_so_ops.handle_event = irix_solib_handle_event;