1 /* Handle SVR4 shared libraries for GDB, the GNU Debugger.
3 Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1998, 1999, 2000,
4 2001, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011
5 Free Software Foundation, Inc.
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/>. */
24 #include "elf/external.h"
25 #include "elf/common.h"
36 #include "gdbthread.h"
39 #include "gdb_assert.h"
43 #include "solib-svr4.h"
45 #include "bfd-target.h"
49 #include "exceptions.h"
51 static struct link_map_offsets *svr4_fetch_link_map_offsets (void);
52 static int svr4_have_link_map_offsets (void);
53 static void svr4_relocate_main_executable (void);
55 /* Link map info to include in an allocated so_list entry */
59 /* Pointer to copy of link map from inferior. The type is char *
60 rather than void *, so that we may use byte offsets to find the
61 various fields without the need for a cast. */
64 /* Amount by which addresses in the binary should be relocated to
65 match the inferior. This could most often be taken directly
66 from lm, but when prelinking is involved and the prelink base
67 address changes, we may need a different offset, we want to
68 warn about the difference and compute it only once. */
71 /* The target location of lm. */
75 /* On SVR4 systems, a list of symbols in the dynamic linker where
76 GDB can try to place a breakpoint to monitor shared library
79 If none of these symbols are found, or other errors occur, then
80 SVR4 systems will fall back to using a symbol as the "startup
81 mapping complete" breakpoint address. */
83 static const char * const solib_break_names[] =
89 "__dl_rtld_db_dlactivity",
95 static const char * const bkpt_names[] =
103 static const char * const main_name_list[] =
109 /* Return non-zero if GDB_SO_NAME and INFERIOR_SO_NAME represent
110 the same shared library. */
113 svr4_same_1 (const char *gdb_so_name, const char *inferior_so_name)
115 if (strcmp (gdb_so_name, inferior_so_name) == 0)
118 /* On Solaris, when starting inferior we think that dynamic linker is
119 /usr/lib/ld.so.1, but later on, the table of loaded shared libraries
120 contains /lib/ld.so.1. Sometimes one file is a link to another, but
121 sometimes they have identical content, but are not linked to each
122 other. We don't restrict this check for Solaris, but the chances
123 of running into this situation elsewhere are very low. */
124 if (strcmp (gdb_so_name, "/usr/lib/ld.so.1") == 0
125 && strcmp (inferior_so_name, "/lib/ld.so.1") == 0)
128 /* Similarly, we observed the same issue with sparc64, but with
129 different locations. */
130 if (strcmp (gdb_so_name, "/usr/lib/sparcv9/ld.so.1") == 0
131 && strcmp (inferior_so_name, "/lib/sparcv9/ld.so.1") == 0)
138 svr4_same (struct so_list *gdb, struct so_list *inferior)
140 return (svr4_same_1 (gdb->so_original_name, inferior->so_original_name));
143 /* link map access functions */
146 LM_ADDR_FROM_LINK_MAP (struct so_list *so)
148 struct link_map_offsets *lmo = svr4_fetch_link_map_offsets ();
149 struct type *ptr_type = builtin_type (target_gdbarch)->builtin_data_ptr;
151 return extract_typed_address (so->lm_info->lm + lmo->l_addr_offset,
156 HAS_LM_DYNAMIC_FROM_LINK_MAP (void)
158 struct link_map_offsets *lmo = svr4_fetch_link_map_offsets ();
160 return lmo->l_ld_offset >= 0;
164 LM_DYNAMIC_FROM_LINK_MAP (struct so_list *so)
166 struct link_map_offsets *lmo = svr4_fetch_link_map_offsets ();
167 struct type *ptr_type = builtin_type (target_gdbarch)->builtin_data_ptr;
169 return extract_typed_address (so->lm_info->lm + lmo->l_ld_offset,
174 LM_ADDR_CHECK (struct so_list *so, bfd *abfd)
176 if (so->lm_info->l_addr == (CORE_ADDR)-1)
178 struct bfd_section *dyninfo_sect;
179 CORE_ADDR l_addr, l_dynaddr, dynaddr;
181 l_addr = LM_ADDR_FROM_LINK_MAP (so);
183 if (! abfd || ! HAS_LM_DYNAMIC_FROM_LINK_MAP ())
186 l_dynaddr = LM_DYNAMIC_FROM_LINK_MAP (so);
188 dyninfo_sect = bfd_get_section_by_name (abfd, ".dynamic");
189 if (dyninfo_sect == NULL)
192 dynaddr = bfd_section_vma (abfd, dyninfo_sect);
194 if (dynaddr + l_addr != l_dynaddr)
196 CORE_ADDR align = 0x1000;
197 CORE_ADDR minpagesize = align;
199 if (bfd_get_flavour (abfd) == bfd_target_elf_flavour)
201 Elf_Internal_Ehdr *ehdr = elf_tdata (abfd)->elf_header;
202 Elf_Internal_Phdr *phdr = elf_tdata (abfd)->phdr;
207 for (i = 0; i < ehdr->e_phnum; i++)
208 if (phdr[i].p_type == PT_LOAD && phdr[i].p_align > align)
209 align = phdr[i].p_align;
211 minpagesize = get_elf_backend_data (abfd)->minpagesize;
214 /* Turn it into a mask. */
217 /* If the changes match the alignment requirements, we
218 assume we're using a core file that was generated by the
219 same binary, just prelinked with a different base offset.
220 If it doesn't match, we may have a different binary, the
221 same binary with the dynamic table loaded at an unrelated
222 location, or anything, really. To avoid regressions,
223 don't adjust the base offset in the latter case, although
224 odds are that, if things really changed, debugging won't
227 One could expect more the condition
228 ((l_addr & align) == 0 && ((l_dynaddr - dynaddr) & align) == 0)
229 but the one below is relaxed for PPC. The PPC kernel supports
230 either 4k or 64k page sizes. To be prepared for 64k pages,
231 PPC ELF files are built using an alignment requirement of 64k.
232 However, when running on a kernel supporting 4k pages, the memory
233 mapping of the library may not actually happen on a 64k boundary!
235 (In the usual case where (l_addr & align) == 0, this check is
236 equivalent to the possibly expected check above.)
238 Even on PPC it must be zero-aligned at least for MINPAGESIZE. */
240 if ((l_addr & (minpagesize - 1)) == 0
241 && (l_addr & align) == ((l_dynaddr - dynaddr) & align))
243 l_addr = l_dynaddr - dynaddr;
246 printf_unfiltered (_("Using PIC (Position Independent Code) "
247 "prelink displacement %s for \"%s\".\n"),
248 paddress (target_gdbarch, l_addr),
252 warning (_(".dynamic section for \"%s\" "
253 "is not at the expected address "
254 "(wrong library or version mismatch?)"), so->so_name);
258 so->lm_info->l_addr = l_addr;
261 return so->lm_info->l_addr;
265 LM_NEXT (struct so_list *so)
267 struct link_map_offsets *lmo = svr4_fetch_link_map_offsets ();
268 struct type *ptr_type = builtin_type (target_gdbarch)->builtin_data_ptr;
270 return extract_typed_address (so->lm_info->lm + lmo->l_next_offset,
275 LM_PREV (struct so_list *so)
277 struct link_map_offsets *lmo = svr4_fetch_link_map_offsets ();
278 struct type *ptr_type = builtin_type (target_gdbarch)->builtin_data_ptr;
280 return extract_typed_address (so->lm_info->lm + lmo->l_prev_offset,
285 LM_NAME (struct so_list *so)
287 struct link_map_offsets *lmo = svr4_fetch_link_map_offsets ();
288 struct type *ptr_type = builtin_type (target_gdbarch)->builtin_data_ptr;
290 return extract_typed_address (so->lm_info->lm + lmo->l_name_offset,
295 IGNORE_FIRST_LINK_MAP_ENTRY (struct so_list *so)
297 /* Assume that everything is a library if the dynamic loader was loaded
298 late by a static executable. */
299 if (exec_bfd && bfd_get_section_by_name (exec_bfd, ".dynamic") == NULL)
302 return LM_PREV (so) == 0;
305 /* Per pspace SVR4 specific data. */
309 CORE_ADDR debug_base; /* Base of dynamic linker structures */
311 /* Validity flag for debug_loader_offset. */
312 int debug_loader_offset_p;
314 /* Load address for the dynamic linker, inferred. */
315 CORE_ADDR debug_loader_offset;
317 /* Name of the dynamic linker, valid if debug_loader_offset_p. */
318 char *debug_loader_name;
320 /* Load map address for the main executable. */
321 CORE_ADDR main_lm_addr;
323 CORE_ADDR interp_text_sect_low;
324 CORE_ADDR interp_text_sect_high;
325 CORE_ADDR interp_plt_sect_low;
326 CORE_ADDR interp_plt_sect_high;
329 /* Per-program-space data key. */
330 static const struct program_space_data *solib_svr4_pspace_data;
333 svr4_pspace_data_cleanup (struct program_space *pspace, void *arg)
335 struct svr4_info *info;
337 info = program_space_data (pspace, solib_svr4_pspace_data);
341 /* Get the current svr4 data. If none is found yet, add it now. This
342 function always returns a valid object. */
344 static struct svr4_info *
347 struct svr4_info *info;
349 info = program_space_data (current_program_space, solib_svr4_pspace_data);
353 info = XZALLOC (struct svr4_info);
354 set_program_space_data (current_program_space, solib_svr4_pspace_data, info);
358 /* Local function prototypes */
360 static int match_main (const char *);
366 bfd_lookup_symbol -- lookup the value for a specific symbol
370 CORE_ADDR bfd_lookup_symbol (bfd *abfd, char *symname)
374 An expensive way to lookup the value of a single symbol for
375 bfd's that are only temporary anyway. This is used by the
376 shared library support to find the address of the debugger
377 notification routine in the shared library.
379 The returned symbol may be in a code or data section; functions
380 will normally be in a code section, but may be in a data section
381 if this architecture uses function descriptors.
383 Note that 0 is specifically allowed as an error return (no
388 bfd_lookup_symbol (bfd *abfd, const char *symname)
392 asymbol **symbol_table;
393 unsigned int number_of_symbols;
395 struct cleanup *back_to;
396 CORE_ADDR symaddr = 0;
398 storage_needed = bfd_get_symtab_upper_bound (abfd);
400 if (storage_needed > 0)
402 symbol_table = (asymbol **) xmalloc (storage_needed);
403 back_to = make_cleanup (xfree, symbol_table);
404 number_of_symbols = bfd_canonicalize_symtab (abfd, symbol_table);
406 for (i = 0; i < number_of_symbols; i++)
408 sym = *symbol_table++;
409 if (strcmp (sym->name, symname) == 0
410 && (sym->section->flags & (SEC_CODE | SEC_DATA)) != 0)
412 /* BFD symbols are section relative. */
413 symaddr = sym->value + sym->section->vma;
417 do_cleanups (back_to);
423 /* On FreeBSD, the dynamic linker is stripped by default. So we'll
424 have to check the dynamic string table too. */
426 storage_needed = bfd_get_dynamic_symtab_upper_bound (abfd);
428 if (storage_needed > 0)
430 symbol_table = (asymbol **) xmalloc (storage_needed);
431 back_to = make_cleanup (xfree, symbol_table);
432 number_of_symbols = bfd_canonicalize_dynamic_symtab (abfd, symbol_table);
434 for (i = 0; i < number_of_symbols; i++)
436 sym = *symbol_table++;
438 if (strcmp (sym->name, symname) == 0
439 && (sym->section->flags & (SEC_CODE | SEC_DATA)) != 0)
441 /* BFD symbols are section relative. */
442 symaddr = sym->value + sym->section->vma;
446 do_cleanups (back_to);
453 /* Read program header TYPE from inferior memory. The header is found
454 by scanning the OS auxillary vector.
456 If TYPE == -1, return the program headers instead of the contents of
459 Return a pointer to allocated memory holding the program header contents,
460 or NULL on failure. If sucessful, and unless P_SECT_SIZE is NULL, the
461 size of those contents is returned to P_SECT_SIZE. Likewise, the target
462 architecture size (32-bit or 64-bit) is returned to P_ARCH_SIZE. */
465 read_program_header (int type, int *p_sect_size, int *p_arch_size)
467 enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch);
468 CORE_ADDR at_phdr, at_phent, at_phnum;
469 int arch_size, sect_size;
473 /* Get required auxv elements from target. */
474 if (target_auxv_search (¤t_target, AT_PHDR, &at_phdr) <= 0)
476 if (target_auxv_search (¤t_target, AT_PHENT, &at_phent) <= 0)
478 if (target_auxv_search (¤t_target, AT_PHNUM, &at_phnum) <= 0)
480 if (!at_phdr || !at_phnum)
483 /* Determine ELF architecture type. */
484 if (at_phent == sizeof (Elf32_External_Phdr))
486 else if (at_phent == sizeof (Elf64_External_Phdr))
491 /* Find the requested segment. */
495 sect_size = at_phent * at_phnum;
497 else if (arch_size == 32)
499 Elf32_External_Phdr phdr;
502 /* Search for requested PHDR. */
503 for (i = 0; i < at_phnum; i++)
505 if (target_read_memory (at_phdr + i * sizeof (phdr),
506 (gdb_byte *)&phdr, sizeof (phdr)))
509 if (extract_unsigned_integer ((gdb_byte *)phdr.p_type,
510 4, byte_order) == type)
517 /* Retrieve address and size. */
518 sect_addr = extract_unsigned_integer ((gdb_byte *)phdr.p_vaddr,
520 sect_size = extract_unsigned_integer ((gdb_byte *)phdr.p_memsz,
525 Elf64_External_Phdr phdr;
528 /* Search for requested PHDR. */
529 for (i = 0; i < at_phnum; i++)
531 if (target_read_memory (at_phdr + i * sizeof (phdr),
532 (gdb_byte *)&phdr, sizeof (phdr)))
535 if (extract_unsigned_integer ((gdb_byte *)phdr.p_type,
536 4, byte_order) == type)
543 /* Retrieve address and size. */
544 sect_addr = extract_unsigned_integer ((gdb_byte *)phdr.p_vaddr,
546 sect_size = extract_unsigned_integer ((gdb_byte *)phdr.p_memsz,
550 /* Read in requested program header. */
551 buf = xmalloc (sect_size);
552 if (target_read_memory (sect_addr, buf, sect_size))
559 *p_arch_size = arch_size;
561 *p_sect_size = sect_size;
567 /* Return program interpreter string. */
569 find_program_interpreter (void)
571 gdb_byte *buf = NULL;
573 /* If we have an exec_bfd, use its section table. */
575 && bfd_get_flavour (exec_bfd) == bfd_target_elf_flavour)
577 struct bfd_section *interp_sect;
579 interp_sect = bfd_get_section_by_name (exec_bfd, ".interp");
580 if (interp_sect != NULL)
582 int sect_size = bfd_section_size (exec_bfd, interp_sect);
584 buf = xmalloc (sect_size);
585 bfd_get_section_contents (exec_bfd, interp_sect, buf, 0, sect_size);
589 /* If we didn't find it, use the target auxillary vector. */
591 buf = read_program_header (PT_INTERP, NULL, NULL);
597 /* Scan for DYNTAG in .dynamic section of ABFD. If DYNTAG is found 1 is
598 returned and the corresponding PTR is set. */
601 scan_dyntag (int dyntag, bfd *abfd, CORE_ADDR *ptr)
603 int arch_size, step, sect_size;
605 CORE_ADDR dyn_ptr, dyn_addr;
606 gdb_byte *bufend, *bufstart, *buf;
607 Elf32_External_Dyn *x_dynp_32;
608 Elf64_External_Dyn *x_dynp_64;
609 struct bfd_section *sect;
610 struct target_section *target_section;
615 if (bfd_get_flavour (abfd) != bfd_target_elf_flavour)
618 arch_size = bfd_get_arch_size (abfd);
622 /* Find the start address of the .dynamic section. */
623 sect = bfd_get_section_by_name (abfd, ".dynamic");
627 for (target_section = current_target_sections->sections;
628 target_section < current_target_sections->sections_end;
630 if (sect == target_section->the_bfd_section)
632 if (target_section < current_target_sections->sections_end)
633 dyn_addr = target_section->addr;
636 /* ABFD may come from OBJFILE acting only as a symbol file without being
637 loaded into the target (see add_symbol_file_command). This case is
638 such fallback to the file VMA address without the possibility of
639 having the section relocated to its actual in-memory address. */
641 dyn_addr = bfd_section_vma (abfd, sect);
644 /* Read in .dynamic from the BFD. We will get the actual value
645 from memory later. */
646 sect_size = bfd_section_size (abfd, sect);
647 buf = bufstart = alloca (sect_size);
648 if (!bfd_get_section_contents (abfd, sect,
652 /* Iterate over BUF and scan for DYNTAG. If found, set PTR and return. */
653 step = (arch_size == 32) ? sizeof (Elf32_External_Dyn)
654 : sizeof (Elf64_External_Dyn);
655 for (bufend = buf + sect_size;
661 x_dynp_32 = (Elf32_External_Dyn *) buf;
662 dyn_tag = bfd_h_get_32 (abfd, (bfd_byte *) x_dynp_32->d_tag);
663 dyn_ptr = bfd_h_get_32 (abfd, (bfd_byte *) x_dynp_32->d_un.d_ptr);
667 x_dynp_64 = (Elf64_External_Dyn *) buf;
668 dyn_tag = bfd_h_get_64 (abfd, (bfd_byte *) x_dynp_64->d_tag);
669 dyn_ptr = bfd_h_get_64 (abfd, (bfd_byte *) x_dynp_64->d_un.d_ptr);
671 if (dyn_tag == DT_NULL)
673 if (dyn_tag == dyntag)
675 /* If requested, try to read the runtime value of this .dynamic
679 struct type *ptr_type;
683 ptr_type = builtin_type (target_gdbarch)->builtin_data_ptr;
684 ptr_addr = dyn_addr + (buf - bufstart) + arch_size / 8;
685 if (target_read_memory (ptr_addr, ptr_buf, arch_size / 8) == 0)
686 dyn_ptr = extract_typed_address (ptr_buf, ptr_type);
696 /* Scan for DYNTAG in .dynamic section of the target's main executable,
697 found by consulting the OS auxillary vector. If DYNTAG is found 1 is
698 returned and the corresponding PTR is set. */
701 scan_dyntag_auxv (int dyntag, CORE_ADDR *ptr)
703 enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch);
704 int sect_size, arch_size, step;
707 gdb_byte *bufend, *bufstart, *buf;
709 /* Read in .dynamic section. */
710 buf = bufstart = read_program_header (PT_DYNAMIC, §_size, &arch_size);
714 /* Iterate over BUF and scan for DYNTAG. If found, set PTR and return. */
715 step = (arch_size == 32) ? sizeof (Elf32_External_Dyn)
716 : sizeof (Elf64_External_Dyn);
717 for (bufend = buf + sect_size;
723 Elf32_External_Dyn *dynp = (Elf32_External_Dyn *) buf;
725 dyn_tag = extract_unsigned_integer ((gdb_byte *) dynp->d_tag,
727 dyn_ptr = extract_unsigned_integer ((gdb_byte *) dynp->d_un.d_ptr,
732 Elf64_External_Dyn *dynp = (Elf64_External_Dyn *) buf;
734 dyn_tag = extract_unsigned_integer ((gdb_byte *) dynp->d_tag,
736 dyn_ptr = extract_unsigned_integer ((gdb_byte *) dynp->d_un.d_ptr,
739 if (dyn_tag == DT_NULL)
742 if (dyn_tag == dyntag)
761 elf_locate_base -- locate the base address of dynamic linker structs
762 for SVR4 elf targets.
766 CORE_ADDR elf_locate_base (void)
770 For SVR4 elf targets the address of the dynamic linker's runtime
771 structure is contained within the dynamic info section in the
772 executable file. The dynamic section is also mapped into the
773 inferior address space. Because the runtime loader fills in the
774 real address before starting the inferior, we have to read in the
775 dynamic info section from the inferior address space.
776 If there are any errors while trying to find the address, we
777 silently return 0, otherwise the found address is returned.
782 elf_locate_base (void)
784 struct minimal_symbol *msymbol;
787 /* Look for DT_MIPS_RLD_MAP first. MIPS executables use this
788 instead of DT_DEBUG, although they sometimes contain an unused
790 if (scan_dyntag (DT_MIPS_RLD_MAP, exec_bfd, &dyn_ptr)
791 || scan_dyntag_auxv (DT_MIPS_RLD_MAP, &dyn_ptr))
793 struct type *ptr_type = builtin_type (target_gdbarch)->builtin_data_ptr;
795 int pbuf_size = TYPE_LENGTH (ptr_type);
797 pbuf = alloca (pbuf_size);
798 /* DT_MIPS_RLD_MAP contains a pointer to the address
799 of the dynamic link structure. */
800 if (target_read_memory (dyn_ptr, pbuf, pbuf_size))
802 return extract_typed_address (pbuf, ptr_type);
806 if (scan_dyntag (DT_DEBUG, exec_bfd, &dyn_ptr)
807 || scan_dyntag_auxv (DT_DEBUG, &dyn_ptr))
810 /* This may be a static executable. Look for the symbol
811 conventionally named _r_debug, as a last resort. */
812 msymbol = lookup_minimal_symbol ("_r_debug", NULL, symfile_objfile);
814 return SYMBOL_VALUE_ADDRESS (msymbol);
816 /* DT_DEBUG entry not found. */
824 locate_base -- locate the base address of dynamic linker structs
828 CORE_ADDR locate_base (struct svr4_info *)
832 For both the SunOS and SVR4 shared library implementations, if the
833 inferior executable has been linked dynamically, there is a single
834 address somewhere in the inferior's data space which is the key to
835 locating all of the dynamic linker's runtime structures. This
836 address is the value of the debug base symbol. The job of this
837 function is to find and return that address, or to return 0 if there
838 is no such address (the executable is statically linked for example).
840 For SunOS, the job is almost trivial, since the dynamic linker and
841 all of it's structures are statically linked to the executable at
842 link time. Thus the symbol for the address we are looking for has
843 already been added to the minimal symbol table for the executable's
844 objfile at the time the symbol file's symbols were read, and all we
845 have to do is look it up there. Note that we explicitly do NOT want
846 to find the copies in the shared library.
848 The SVR4 version is a bit more complicated because the address
849 is contained somewhere in the dynamic info section. We have to go
850 to a lot more work to discover the address of the debug base symbol.
851 Because of this complexity, we cache the value we find and return that
852 value on subsequent invocations. Note there is no copy in the
853 executable symbol tables.
858 locate_base (struct svr4_info *info)
860 /* Check to see if we have a currently valid address, and if so, avoid
861 doing all this work again and just return the cached address. If
862 we have no cached address, try to locate it in the dynamic info
863 section for ELF executables. There's no point in doing any of this
864 though if we don't have some link map offsets to work with. */
866 if (info->debug_base == 0 && svr4_have_link_map_offsets ())
867 info->debug_base = elf_locate_base ();
868 return info->debug_base;
871 /* Find the first element in the inferior's dynamic link map, and
872 return its address in the inferior. Return zero if the address
873 could not be determined.
875 FIXME: Perhaps we should validate the info somehow, perhaps by
876 checking r_version for a known version number, or r_state for
880 solib_svr4_r_map (struct svr4_info *info)
882 struct link_map_offsets *lmo = svr4_fetch_link_map_offsets ();
883 struct type *ptr_type = builtin_type (target_gdbarch)->builtin_data_ptr;
885 volatile struct gdb_exception ex;
887 TRY_CATCH (ex, RETURN_MASK_ERROR)
889 addr = read_memory_typed_address (info->debug_base + lmo->r_map_offset,
892 exception_print (gdb_stderr, ex);
896 /* Find r_brk from the inferior's debug base. */
899 solib_svr4_r_brk (struct svr4_info *info)
901 struct link_map_offsets *lmo = svr4_fetch_link_map_offsets ();
902 struct type *ptr_type = builtin_type (target_gdbarch)->builtin_data_ptr;
904 return read_memory_typed_address (info->debug_base + lmo->r_brk_offset,
908 /* Find the link map for the dynamic linker (if it is not in the
909 normal list of loaded shared objects). */
912 solib_svr4_r_ldsomap (struct svr4_info *info)
914 struct link_map_offsets *lmo = svr4_fetch_link_map_offsets ();
915 struct type *ptr_type = builtin_type (target_gdbarch)->builtin_data_ptr;
916 enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch);
919 /* Check version, and return zero if `struct r_debug' doesn't have
920 the r_ldsomap member. */
922 = read_memory_unsigned_integer (info->debug_base + lmo->r_version_offset,
923 lmo->r_version_size, byte_order);
924 if (version < 2 || lmo->r_ldsomap_offset == -1)
927 return read_memory_typed_address (info->debug_base + lmo->r_ldsomap_offset,
931 /* On Solaris systems with some versions of the dynamic linker,
932 ld.so's l_name pointer points to the SONAME in the string table
933 rather than into writable memory. So that GDB can find shared
934 libraries when loading a core file generated by gcore, ensure that
935 memory areas containing the l_name string are saved in the core
939 svr4_keep_data_in_core (CORE_ADDR vaddr, unsigned long size)
941 struct svr4_info *info;
944 struct cleanup *old_chain;
945 struct link_map_offsets *lmo;
948 info = get_svr4_info ();
950 info->debug_base = 0;
952 if (!info->debug_base)
955 ldsomap = solib_svr4_r_ldsomap (info);
959 lmo = svr4_fetch_link_map_offsets ();
960 new = XZALLOC (struct so_list);
961 old_chain = make_cleanup (xfree, new);
962 new->lm_info = xmalloc (sizeof (struct lm_info));
963 make_cleanup (xfree, new->lm_info);
964 new->lm_info->l_addr = (CORE_ADDR)-1;
965 new->lm_info->lm_addr = ldsomap;
966 new->lm_info->lm = xzalloc (lmo->link_map_size);
967 make_cleanup (xfree, new->lm_info->lm);
968 read_memory (ldsomap, new->lm_info->lm, lmo->link_map_size);
969 lm_name = LM_NAME (new);
970 do_cleanups (old_chain);
972 return (lm_name >= vaddr && lm_name < vaddr + size);
979 open_symbol_file_object
983 void open_symbol_file_object (void *from_tty)
987 If no open symbol file, attempt to locate and open the main symbol
988 file. On SVR4 systems, this is the first link map entry. If its
989 name is here, we can open it. Useful when attaching to a process
990 without first loading its symbol file.
992 If FROM_TTYP dereferences to a non-zero integer, allow messages to
993 be printed. This parameter is a pointer rather than an int because
994 open_symbol_file_object() is called via catch_errors() and
995 catch_errors() requires a pointer argument. */
998 open_symbol_file_object (void *from_ttyp)
1000 CORE_ADDR lm, l_name;
1003 int from_tty = *(int *)from_ttyp;
1004 struct link_map_offsets *lmo = svr4_fetch_link_map_offsets ();
1005 struct type *ptr_type = builtin_type (target_gdbarch)->builtin_data_ptr;
1006 int l_name_size = TYPE_LENGTH (ptr_type);
1007 gdb_byte *l_name_buf = xmalloc (l_name_size);
1008 struct cleanup *cleanups = make_cleanup (xfree, l_name_buf);
1009 struct svr4_info *info = get_svr4_info ();
1011 if (symfile_objfile)
1012 if (!query (_("Attempt to reload symbols from process? ")))
1015 /* Always locate the debug struct, in case it has moved. */
1016 info->debug_base = 0;
1017 if (locate_base (info) == 0)
1018 return 0; /* failed somehow... */
1020 /* First link map member should be the executable. */
1021 lm = solib_svr4_r_map (info);
1023 return 0; /* failed somehow... */
1025 /* Read address of name from target memory to GDB. */
1026 read_memory (lm + lmo->l_name_offset, l_name_buf, l_name_size);
1028 /* Convert the address to host format. */
1029 l_name = extract_typed_address (l_name_buf, ptr_type);
1031 /* Free l_name_buf. */
1032 do_cleanups (cleanups);
1035 return 0; /* No filename. */
1037 /* Now fetch the filename from target memory. */
1038 target_read_string (l_name, &filename, SO_NAME_MAX_PATH_SIZE - 1, &errcode);
1039 make_cleanup (xfree, filename);
1043 warning (_("failed to read exec filename from attached file: %s"),
1044 safe_strerror (errcode));
1048 /* Have a pathname: read the symbol file. */
1049 symbol_file_add_main (filename, from_tty);
1054 /* If no shared library information is available from the dynamic
1055 linker, build a fallback list from other sources. */
1057 static struct so_list *
1058 svr4_default_sos (void)
1060 struct svr4_info *info = get_svr4_info ();
1062 struct so_list *head = NULL;
1063 struct so_list **link_ptr = &head;
1065 if (info->debug_loader_offset_p)
1067 struct so_list *new = XZALLOC (struct so_list);
1069 new->lm_info = xmalloc (sizeof (struct lm_info));
1071 /* Nothing will ever check the cached copy of the link
1072 map if we set l_addr. */
1073 new->lm_info->l_addr = info->debug_loader_offset;
1074 new->lm_info->lm_addr = 0;
1075 new->lm_info->lm = NULL;
1077 strncpy (new->so_name, info->debug_loader_name,
1078 SO_NAME_MAX_PATH_SIZE - 1);
1079 new->so_name[SO_NAME_MAX_PATH_SIZE - 1] = '\0';
1080 strcpy (new->so_original_name, new->so_name);
1083 link_ptr = &new->next;
1091 current_sos -- build a list of currently loaded shared objects
1095 struct so_list *current_sos ()
1099 Build a list of `struct so_list' objects describing the shared
1100 objects currently loaded in the inferior. This list does not
1101 include an entry for the main executable file.
1103 Note that we only gather information directly available from the
1104 inferior --- we don't examine any of the shared library files
1105 themselves. The declaration of `struct so_list' says which fields
1106 we provide values for. */
1108 static struct so_list *
1109 svr4_current_sos (void)
1111 CORE_ADDR lm, prev_lm;
1112 struct so_list *head = 0;
1113 struct so_list **link_ptr = &head;
1114 CORE_ADDR ldsomap = 0;
1115 struct svr4_info *info;
1117 info = get_svr4_info ();
1119 /* Always locate the debug struct, in case it has moved. */
1120 info->debug_base = 0;
1123 /* If we can't find the dynamic linker's base structure, this
1124 must not be a dynamically linked executable. Hmm. */
1125 if (! info->debug_base)
1126 return svr4_default_sos ();
1128 /* Walk the inferior's link map list, and build our list of
1129 `struct so_list' nodes. */
1131 lm = solib_svr4_r_map (info);
1135 struct link_map_offsets *lmo = svr4_fetch_link_map_offsets ();
1136 struct so_list *new = XZALLOC (struct so_list);
1137 struct cleanup *old_chain = make_cleanup (xfree, new);
1140 new->lm_info = xmalloc (sizeof (struct lm_info));
1141 make_cleanup (xfree, new->lm_info);
1143 new->lm_info->l_addr = (CORE_ADDR)-1;
1144 new->lm_info->lm_addr = lm;
1145 new->lm_info->lm = xzalloc (lmo->link_map_size);
1146 make_cleanup (xfree, new->lm_info->lm);
1148 read_memory (lm, new->lm_info->lm, lmo->link_map_size);
1150 next_lm = LM_NEXT (new);
1152 if (LM_PREV (new) != prev_lm)
1154 warning (_("Corrupted shared library list"));
1159 /* For SVR4 versions, the first entry in the link map is for the
1160 inferior executable, so we must ignore it. For some versions of
1161 SVR4, it has no name. For others (Solaris 2.3 for example), it
1162 does have a name, so we can no longer use a missing name to
1163 decide when to ignore it. */
1164 else if (IGNORE_FIRST_LINK_MAP_ENTRY (new) && ldsomap == 0)
1166 info->main_lm_addr = new->lm_info->lm_addr;
1174 /* Extract this shared object's name. */
1175 target_read_string (LM_NAME (new), &buffer,
1176 SO_NAME_MAX_PATH_SIZE - 1, &errcode);
1178 warning (_("Can't read pathname for load map: %s."),
1179 safe_strerror (errcode));
1182 strncpy (new->so_name, buffer, SO_NAME_MAX_PATH_SIZE - 1);
1183 new->so_name[SO_NAME_MAX_PATH_SIZE - 1] = '\0';
1184 strcpy (new->so_original_name, new->so_name);
1188 /* If this entry has no name, or its name matches the name
1189 for the main executable, don't include it in the list. */
1190 if (! new->so_name[0]
1191 || match_main (new->so_name))
1197 link_ptr = &new->next;
1204 /* On Solaris, the dynamic linker is not in the normal list of
1205 shared objects, so make sure we pick it up too. Having
1206 symbol information for the dynamic linker is quite crucial
1207 for skipping dynamic linker resolver code. */
1208 if (lm == 0 && ldsomap == 0)
1210 lm = ldsomap = solib_svr4_r_ldsomap (info);
1214 discard_cleanups (old_chain);
1218 return svr4_default_sos ();
1223 /* Get the address of the link_map for a given OBJFILE. */
1226 svr4_fetch_objfile_link_map (struct objfile *objfile)
1229 struct svr4_info *info = get_svr4_info ();
1231 /* Cause svr4_current_sos() to be run if it hasn't been already. */
1232 if (info->main_lm_addr == 0)
1233 solib_add (NULL, 0, ¤t_target, auto_solib_add);
1235 /* svr4_current_sos() will set main_lm_addr for the main executable. */
1236 if (objfile == symfile_objfile)
1237 return info->main_lm_addr;
1239 /* The other link map addresses may be found by examining the list
1240 of shared libraries. */
1241 for (so = master_so_list (); so; so = so->next)
1242 if (so->objfile == objfile)
1243 return so->lm_info->lm_addr;
1249 /* On some systems, the only way to recognize the link map entry for
1250 the main executable file is by looking at its name. Return
1251 non-zero iff SONAME matches one of the known main executable names. */
1254 match_main (const char *soname)
1256 const char * const *mainp;
1258 for (mainp = main_name_list; *mainp != NULL; mainp++)
1260 if (strcmp (soname, *mainp) == 0)
1267 /* Return 1 if PC lies in the dynamic symbol resolution code of the
1268 SVR4 run time loader. */
1271 svr4_in_dynsym_resolve_code (CORE_ADDR pc)
1273 struct svr4_info *info = get_svr4_info ();
1275 return ((pc >= info->interp_text_sect_low
1276 && pc < info->interp_text_sect_high)
1277 || (pc >= info->interp_plt_sect_low
1278 && pc < info->interp_plt_sect_high)
1279 || in_plt_section (pc, NULL));
1282 /* Given an executable's ABFD and target, compute the entry-point
1286 exec_entry_point (struct bfd *abfd, struct target_ops *targ)
1288 /* KevinB wrote ... for most targets, the address returned by
1289 bfd_get_start_address() is the entry point for the start
1290 function. But, for some targets, bfd_get_start_address() returns
1291 the address of a function descriptor from which the entry point
1292 address may be extracted. This address is extracted by
1293 gdbarch_convert_from_func_ptr_addr(). The method
1294 gdbarch_convert_from_func_ptr_addr() is the merely the identify
1295 function for targets which don't use function descriptors. */
1296 return gdbarch_convert_from_func_ptr_addr (target_gdbarch,
1297 bfd_get_start_address (abfd),
1305 enable_break -- arrange for dynamic linker to hit breakpoint
1309 int enable_break (void)
1313 Both the SunOS and the SVR4 dynamic linkers have, as part of their
1314 debugger interface, support for arranging for the inferior to hit
1315 a breakpoint after mapping in the shared libraries. This function
1316 enables that breakpoint.
1318 For SunOS, there is a special flag location (in_debugger) which we
1319 set to 1. When the dynamic linker sees this flag set, it will set
1320 a breakpoint at a location known only to itself, after saving the
1321 original contents of that place and the breakpoint address itself,
1322 in it's own internal structures. When we resume the inferior, it
1323 will eventually take a SIGTRAP when it runs into the breakpoint.
1324 We handle this (in a different place) by restoring the contents of
1325 the breakpointed location (which is only known after it stops),
1326 chasing around to locate the shared libraries that have been
1327 loaded, then resuming.
1329 For SVR4, the debugger interface structure contains a member (r_brk)
1330 which is statically initialized at the time the shared library is
1331 built, to the offset of a function (_r_debug_state) which is guaran-
1332 teed to be called once before mapping in a library, and again when
1333 the mapping is complete. At the time we are examining this member,
1334 it contains only the unrelocated offset of the function, so we have
1335 to do our own relocation. Later, when the dynamic linker actually
1336 runs, it relocates r_brk to be the actual address of _r_debug_state().
1338 The debugger interface structure also contains an enumeration which
1339 is set to either RT_ADD or RT_DELETE prior to changing the mapping,
1340 depending upon whether or not the library is being mapped or unmapped,
1341 and then set to RT_CONSISTENT after the library is mapped/unmapped.
1345 enable_break (struct svr4_info *info, int from_tty)
1347 struct minimal_symbol *msymbol;
1348 const char * const *bkpt_namep;
1349 asection *interp_sect;
1350 gdb_byte *interp_name;
1353 info->interp_text_sect_low = info->interp_text_sect_high = 0;
1354 info->interp_plt_sect_low = info->interp_plt_sect_high = 0;
1356 /* If we already have a shared library list in the target, and
1357 r_debug contains r_brk, set the breakpoint there - this should
1358 mean r_brk has already been relocated. Assume the dynamic linker
1359 is the object containing r_brk. */
1361 solib_add (NULL, from_tty, ¤t_target, auto_solib_add);
1363 if (info->debug_base && solib_svr4_r_map (info) != 0)
1364 sym_addr = solib_svr4_r_brk (info);
1368 struct obj_section *os;
1370 sym_addr = gdbarch_addr_bits_remove
1371 (target_gdbarch, gdbarch_convert_from_func_ptr_addr (target_gdbarch,
1375 /* On at least some versions of Solaris there's a dynamic relocation
1376 on _r_debug.r_brk and SYM_ADDR may not be relocated yet, e.g., if
1377 we get control before the dynamic linker has self-relocated.
1378 Check if SYM_ADDR is in a known section, if it is assume we can
1379 trust its value. This is just a heuristic though, it could go away
1380 or be replaced if it's getting in the way.
1382 On ARM we need to know whether the ISA of rtld_db_dlactivity (or
1383 however it's spelled in your particular system) is ARM or Thumb.
1384 That knowledge is encoded in the address, if it's Thumb the low bit
1385 is 1. However, we've stripped that info above and it's not clear
1386 what all the consequences are of passing a non-addr_bits_remove'd
1387 address to create_solib_event_breakpoint. The call to
1388 find_pc_section verifies we know about the address and have some
1389 hope of computing the right kind of breakpoint to use (via
1390 symbol info). It does mean that GDB needs to be pointed at a
1391 non-stripped version of the dynamic linker in order to obtain
1392 information it already knows about. Sigh. */
1394 os = find_pc_section (sym_addr);
1397 /* Record the relocated start and end address of the dynamic linker
1398 text and plt section for svr4_in_dynsym_resolve_code. */
1400 CORE_ADDR load_addr;
1402 tmp_bfd = os->objfile->obfd;
1403 load_addr = ANOFFSET (os->objfile->section_offsets,
1404 os->objfile->sect_index_text);
1406 interp_sect = bfd_get_section_by_name (tmp_bfd, ".text");
1409 info->interp_text_sect_low =
1410 bfd_section_vma (tmp_bfd, interp_sect) + load_addr;
1411 info->interp_text_sect_high =
1412 info->interp_text_sect_low
1413 + bfd_section_size (tmp_bfd, interp_sect);
1415 interp_sect = bfd_get_section_by_name (tmp_bfd, ".plt");
1418 info->interp_plt_sect_low =
1419 bfd_section_vma (tmp_bfd, interp_sect) + load_addr;
1420 info->interp_plt_sect_high =
1421 info->interp_plt_sect_low
1422 + bfd_section_size (tmp_bfd, interp_sect);
1425 create_solib_event_breakpoint (target_gdbarch, sym_addr);
1430 /* Find the program interpreter; if not found, warn the user and drop
1431 into the old breakpoint at symbol code. */
1432 interp_name = find_program_interpreter ();
1435 CORE_ADDR load_addr = 0;
1436 int load_addr_found = 0;
1437 int loader_found_in_list = 0;
1439 bfd *tmp_bfd = NULL;
1440 struct target_ops *tmp_bfd_target;
1441 volatile struct gdb_exception ex;
1445 /* Now we need to figure out where the dynamic linker was
1446 loaded so that we can load its symbols and place a breakpoint
1447 in the dynamic linker itself.
1449 This address is stored on the stack. However, I've been unable
1450 to find any magic formula to find it for Solaris (appears to
1451 be trivial on GNU/Linux). Therefore, we have to try an alternate
1452 mechanism to find the dynamic linker's base address. */
1454 TRY_CATCH (ex, RETURN_MASK_ALL)
1456 tmp_bfd = solib_bfd_open (interp_name);
1458 if (tmp_bfd == NULL)
1459 goto bkpt_at_symbol;
1461 /* Now convert the TMP_BFD into a target. That way target, as
1462 well as BFD operations can be used. Note that closing the
1463 target will also close the underlying bfd. */
1464 tmp_bfd_target = target_bfd_reopen (tmp_bfd);
1466 /* On a running target, we can get the dynamic linker's base
1467 address from the shared library table. */
1468 so = master_so_list ();
1471 if (svr4_same_1 (interp_name, so->so_original_name))
1473 load_addr_found = 1;
1474 loader_found_in_list = 1;
1475 load_addr = LM_ADDR_CHECK (so, tmp_bfd);
1481 /* If we were not able to find the base address of the loader
1482 from our so_list, then try using the AT_BASE auxilliary entry. */
1483 if (!load_addr_found)
1484 if (target_auxv_search (¤t_target, AT_BASE, &load_addr) > 0)
1486 int addr_bit = gdbarch_addr_bit (target_gdbarch);
1488 /* Ensure LOAD_ADDR has proper sign in its possible upper bits so
1489 that `+ load_addr' will overflow CORE_ADDR width not creating
1490 invalid addresses like 0x101234567 for 32bit inferiors on 64bit
1493 if (addr_bit < (sizeof (CORE_ADDR) * HOST_CHAR_BIT))
1495 CORE_ADDR space_size = (CORE_ADDR) 1 << addr_bit;
1496 CORE_ADDR tmp_entry_point = exec_entry_point (tmp_bfd,
1499 gdb_assert (load_addr < space_size);
1501 /* TMP_ENTRY_POINT exceeding SPACE_SIZE would be for prelinked
1502 64bit ld.so with 32bit executable, it should not happen. */
1504 if (tmp_entry_point < space_size
1505 && tmp_entry_point + load_addr >= space_size)
1506 load_addr -= space_size;
1509 load_addr_found = 1;
1512 /* Otherwise we find the dynamic linker's base address by examining
1513 the current pc (which should point at the entry point for the
1514 dynamic linker) and subtracting the offset of the entry point.
1516 This is more fragile than the previous approaches, but is a good
1517 fallback method because it has actually been working well in
1519 if (!load_addr_found)
1521 struct regcache *regcache
1522 = get_thread_arch_regcache (inferior_ptid, target_gdbarch);
1524 load_addr = (regcache_read_pc (regcache)
1525 - exec_entry_point (tmp_bfd, tmp_bfd_target));
1528 if (!loader_found_in_list)
1530 info->debug_loader_name = xstrdup (interp_name);
1531 info->debug_loader_offset_p = 1;
1532 info->debug_loader_offset = load_addr;
1533 solib_add (NULL, from_tty, ¤t_target, auto_solib_add);
1536 /* Record the relocated start and end address of the dynamic linker
1537 text and plt section for svr4_in_dynsym_resolve_code. */
1538 interp_sect = bfd_get_section_by_name (tmp_bfd, ".text");
1541 info->interp_text_sect_low =
1542 bfd_section_vma (tmp_bfd, interp_sect) + load_addr;
1543 info->interp_text_sect_high =
1544 info->interp_text_sect_low
1545 + bfd_section_size (tmp_bfd, interp_sect);
1547 interp_sect = bfd_get_section_by_name (tmp_bfd, ".plt");
1550 info->interp_plt_sect_low =
1551 bfd_section_vma (tmp_bfd, interp_sect) + load_addr;
1552 info->interp_plt_sect_high =
1553 info->interp_plt_sect_low
1554 + bfd_section_size (tmp_bfd, interp_sect);
1557 /* Now try to set a breakpoint in the dynamic linker. */
1558 for (bkpt_namep = solib_break_names; *bkpt_namep != NULL; bkpt_namep++)
1560 sym_addr = bfd_lookup_symbol (tmp_bfd, *bkpt_namep);
1566 /* Convert 'sym_addr' from a function pointer to an address.
1567 Because we pass tmp_bfd_target instead of the current
1568 target, this will always produce an unrelocated value. */
1569 sym_addr = gdbarch_convert_from_func_ptr_addr (target_gdbarch,
1573 /* We're done with both the temporary bfd and target. Remember,
1574 closing the target closes the underlying bfd. */
1575 target_close (tmp_bfd_target, 0);
1579 create_solib_event_breakpoint (target_gdbarch, load_addr + sym_addr);
1580 xfree (interp_name);
1584 /* For whatever reason we couldn't set a breakpoint in the dynamic
1585 linker. Warn and drop into the old code. */
1587 xfree (interp_name);
1588 warning (_("Unable to find dynamic linker breakpoint function.\n"
1589 "GDB will be unable to debug shared library initializers\n"
1590 "and track explicitly loaded dynamic code."));
1593 /* Scan through the lists of symbols, trying to look up the symbol and
1594 set a breakpoint there. Terminate loop when we/if we succeed. */
1596 for (bkpt_namep = solib_break_names; *bkpt_namep != NULL; bkpt_namep++)
1598 msymbol = lookup_minimal_symbol (*bkpt_namep, NULL, symfile_objfile);
1599 if ((msymbol != NULL) && (SYMBOL_VALUE_ADDRESS (msymbol) != 0))
1601 sym_addr = SYMBOL_VALUE_ADDRESS (msymbol);
1602 sym_addr = gdbarch_convert_from_func_ptr_addr (target_gdbarch,
1605 create_solib_event_breakpoint (target_gdbarch, sym_addr);
1610 if (!current_inferior ()->attach_flag)
1612 for (bkpt_namep = bkpt_names; *bkpt_namep != NULL; bkpt_namep++)
1614 msymbol = lookup_minimal_symbol (*bkpt_namep, NULL, symfile_objfile);
1615 if ((msymbol != NULL) && (SYMBOL_VALUE_ADDRESS (msymbol) != 0))
1617 sym_addr = SYMBOL_VALUE_ADDRESS (msymbol);
1618 sym_addr = gdbarch_convert_from_func_ptr_addr (target_gdbarch,
1621 create_solib_event_breakpoint (target_gdbarch, sym_addr);
1633 special_symbol_handling -- additional shared library symbol handling
1637 void special_symbol_handling ()
1641 Once the symbols from a shared object have been loaded in the usual
1642 way, we are called to do any system specific symbol handling that
1645 For SunOS4, this consisted of grunging around in the dynamic
1646 linkers structures to find symbol definitions for "common" symbols
1647 and adding them to the minimal symbol table for the runtime common
1650 However, for SVR4, there's nothing to do.
1655 svr4_special_symbol_handling (void)
1659 /* Read the ELF program headers from ABFD. Return the contents and
1660 set *PHDRS_SIZE to the size of the program headers. */
1663 read_program_headers_from_bfd (bfd *abfd, int *phdrs_size)
1665 Elf_Internal_Ehdr *ehdr;
1668 ehdr = elf_elfheader (abfd);
1670 *phdrs_size = ehdr->e_phnum * ehdr->e_phentsize;
1671 if (*phdrs_size == 0)
1674 buf = xmalloc (*phdrs_size);
1675 if (bfd_seek (abfd, ehdr->e_phoff, SEEK_SET) != 0
1676 || bfd_bread (buf, *phdrs_size, abfd) != *phdrs_size)
1685 /* Return 1 and fill *DISPLACEMENTP with detected PIE offset of inferior
1686 exec_bfd. Otherwise return 0.
1688 We relocate all of the sections by the same amount. This
1689 behavior is mandated by recent editions of the System V ABI.
1690 According to the System V Application Binary Interface,
1691 Edition 4.1, page 5-5:
1693 ... Though the system chooses virtual addresses for
1694 individual processes, it maintains the segments' relative
1695 positions. Because position-independent code uses relative
1696 addressesing between segments, the difference between
1697 virtual addresses in memory must match the difference
1698 between virtual addresses in the file. The difference
1699 between the virtual address of any segment in memory and
1700 the corresponding virtual address in the file is thus a
1701 single constant value for any one executable or shared
1702 object in a given process. This difference is the base
1703 address. One use of the base address is to relocate the
1704 memory image of the program during dynamic linking.
1706 The same language also appears in Edition 4.0 of the System V
1707 ABI and is left unspecified in some of the earlier editions.
1709 Decide if the objfile needs to be relocated. As indicated above, we will
1710 only be here when execution is stopped. But during attachment PC can be at
1711 arbitrary address therefore regcache_read_pc can be misleading (contrary to
1712 the auxv AT_ENTRY value). Moreover for executable with interpreter section
1713 regcache_read_pc would point to the interpreter and not the main executable.
1715 So, to summarize, relocations are necessary when the start address obtained
1716 from the executable is different from the address in auxv AT_ENTRY entry.
1718 [ The astute reader will note that we also test to make sure that
1719 the executable in question has the DYNAMIC flag set. It is my
1720 opinion that this test is unnecessary (undesirable even). It
1721 was added to avoid inadvertent relocation of an executable
1722 whose e_type member in the ELF header is not ET_DYN. There may
1723 be a time in the future when it is desirable to do relocations
1724 on other types of files as well in which case this condition
1725 should either be removed or modified to accomodate the new file
1726 type. - Kevin, Nov 2000. ] */
1729 svr4_exec_displacement (CORE_ADDR *displacementp)
1731 /* ENTRY_POINT is a possible function descriptor - before
1732 a call to gdbarch_convert_from_func_ptr_addr. */
1733 CORE_ADDR entry_point, displacement;
1735 if (exec_bfd == NULL)
1738 /* Therefore for ELF it is ET_EXEC and not ET_DYN. Both shared libraries
1739 being executed themselves and PIE (Position Independent Executable)
1740 executables are ET_DYN. */
1742 if ((bfd_get_file_flags (exec_bfd) & DYNAMIC) == 0)
1745 if (target_auxv_search (¤t_target, AT_ENTRY, &entry_point) <= 0)
1748 displacement = entry_point - bfd_get_start_address (exec_bfd);
1750 /* Verify the DISPLACEMENT candidate complies with the required page
1751 alignment. It is cheaper than the program headers comparison below. */
1753 if (bfd_get_flavour (exec_bfd) == bfd_target_elf_flavour)
1755 const struct elf_backend_data *elf = get_elf_backend_data (exec_bfd);
1757 /* p_align of PT_LOAD segments does not specify any alignment but
1758 only congruency of addresses:
1759 p_offset % p_align == p_vaddr % p_align
1760 Kernel is free to load the executable with lower alignment. */
1762 if ((displacement & (elf->minpagesize - 1)) != 0)
1766 /* Verify that the auxilliary vector describes the same file as exec_bfd, by
1767 comparing their program headers. If the program headers in the auxilliary
1768 vector do not match the program headers in the executable, then we are
1769 looking at a different file than the one used by the kernel - for
1770 instance, "gdb program" connected to "gdbserver :PORT ld.so program". */
1772 if (bfd_get_flavour (exec_bfd) == bfd_target_elf_flavour)
1774 /* Be optimistic and clear OK only if GDB was able to verify the headers
1775 really do not match. */
1776 int phdrs_size, phdrs2_size, ok = 1;
1777 gdb_byte *buf, *buf2;
1780 buf = read_program_header (-1, &phdrs_size, &arch_size);
1781 buf2 = read_program_headers_from_bfd (exec_bfd, &phdrs2_size);
1782 if (buf != NULL && buf2 != NULL)
1784 enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch);
1786 /* We are dealing with three different addresses. EXEC_BFD
1787 represents current address in on-disk file. target memory content
1788 may be different from EXEC_BFD as the file may have been prelinked
1789 to a different address after the executable has been loaded.
1790 Moreover the address of placement in target memory can be
1791 different from what the program headers in target memory say - this
1794 Detected DISPLACEMENT covers both the offsets of PIE placement and
1795 possible new prelink performed after start of the program. Here
1796 relocate BUF and BUF2 just by the EXEC_BFD vs. target memory
1797 content offset for the verification purpose. */
1799 if (phdrs_size != phdrs2_size
1800 || bfd_get_arch_size (exec_bfd) != arch_size)
1802 else if (arch_size == 32 && phdrs_size >= sizeof (Elf32_External_Phdr)
1803 && phdrs_size % sizeof (Elf32_External_Phdr) == 0)
1805 Elf_Internal_Ehdr *ehdr2 = elf_tdata (exec_bfd)->elf_header;
1806 Elf_Internal_Phdr *phdr2 = elf_tdata (exec_bfd)->phdr;
1807 CORE_ADDR displacement = 0;
1810 /* DISPLACEMENT could be found more easily by the difference of
1811 ehdr2->e_entry. But we haven't read the ehdr yet, and we
1812 already have enough information to compute that displacement
1813 with what we've read. */
1815 for (i = 0; i < ehdr2->e_phnum; i++)
1816 if (phdr2[i].p_type == PT_LOAD)
1818 Elf32_External_Phdr *phdrp;
1819 gdb_byte *buf_vaddr_p, *buf_paddr_p;
1820 CORE_ADDR vaddr, paddr;
1821 CORE_ADDR displacement_vaddr = 0;
1822 CORE_ADDR displacement_paddr = 0;
1824 phdrp = &((Elf32_External_Phdr *) buf)[i];
1825 buf_vaddr_p = (gdb_byte *) &phdrp->p_vaddr;
1826 buf_paddr_p = (gdb_byte *) &phdrp->p_paddr;
1828 vaddr = extract_unsigned_integer (buf_vaddr_p, 4,
1830 displacement_vaddr = vaddr - phdr2[i].p_vaddr;
1832 paddr = extract_unsigned_integer (buf_paddr_p, 4,
1834 displacement_paddr = paddr - phdr2[i].p_paddr;
1836 if (displacement_vaddr == displacement_paddr)
1837 displacement = displacement_vaddr;
1842 /* Now compare BUF and BUF2 with optional DISPLACEMENT. */
1844 for (i = 0; i < phdrs_size / sizeof (Elf32_External_Phdr); i++)
1846 Elf32_External_Phdr *phdrp;
1847 Elf32_External_Phdr *phdr2p;
1848 gdb_byte *buf_vaddr_p, *buf_paddr_p;
1849 CORE_ADDR vaddr, paddr;
1850 asection *plt2_asect;
1852 phdrp = &((Elf32_External_Phdr *) buf)[i];
1853 buf_vaddr_p = (gdb_byte *) &phdrp->p_vaddr;
1854 buf_paddr_p = (gdb_byte *) &phdrp->p_paddr;
1855 phdr2p = &((Elf32_External_Phdr *) buf2)[i];
1857 /* PT_GNU_STACK is an exception by being never relocated by
1858 prelink as its addresses are always zero. */
1860 if (memcmp (phdrp, phdr2p, sizeof (*phdrp)) == 0)
1863 /* Check also other adjustment combinations - PR 11786. */
1865 vaddr = extract_unsigned_integer (buf_vaddr_p, 4, byte_order);
1866 vaddr -= displacement;
1867 store_unsigned_integer (buf_vaddr_p, 4, byte_order, vaddr);
1869 paddr = extract_unsigned_integer (buf_paddr_p, 4, byte_order);
1870 paddr -= displacement;
1871 store_unsigned_integer (buf_paddr_p, 4, byte_order, paddr);
1873 if (memcmp (phdrp, phdr2p, sizeof (*phdrp)) == 0)
1876 /* prelink can convert .plt SHT_NOBITS to SHT_PROGBITS. */
1877 plt2_asect = bfd_get_section_by_name (exec_bfd, ".plt");
1881 gdb_byte *buf_filesz_p = (gdb_byte *) &phdrp->p_filesz;
1884 content2 = (bfd_get_section_flags (exec_bfd, plt2_asect)
1885 & SEC_HAS_CONTENTS) != 0;
1887 filesz = extract_unsigned_integer (buf_filesz_p, 4,
1890 /* PLT2_ASECT is from on-disk file (exec_bfd) while
1891 FILESZ is from the in-memory image. */
1893 filesz += bfd_get_section_size (plt2_asect);
1895 filesz -= bfd_get_section_size (plt2_asect);
1897 store_unsigned_integer (buf_filesz_p, 4, byte_order,
1900 if (memcmp (phdrp, phdr2p, sizeof (*phdrp)) == 0)
1908 else if (arch_size == 64 && phdrs_size >= sizeof (Elf64_External_Phdr)
1909 && phdrs_size % sizeof (Elf64_External_Phdr) == 0)
1911 Elf_Internal_Ehdr *ehdr2 = elf_tdata (exec_bfd)->elf_header;
1912 Elf_Internal_Phdr *phdr2 = elf_tdata (exec_bfd)->phdr;
1913 CORE_ADDR displacement = 0;
1916 /* DISPLACEMENT could be found more easily by the difference of
1917 ehdr2->e_entry. But we haven't read the ehdr yet, and we
1918 already have enough information to compute that displacement
1919 with what we've read. */
1921 for (i = 0; i < ehdr2->e_phnum; i++)
1922 if (phdr2[i].p_type == PT_LOAD)
1924 Elf64_External_Phdr *phdrp;
1925 gdb_byte *buf_vaddr_p, *buf_paddr_p;
1926 CORE_ADDR vaddr, paddr;
1927 CORE_ADDR displacement_vaddr = 0;
1928 CORE_ADDR displacement_paddr = 0;
1930 phdrp = &((Elf64_External_Phdr *) buf)[i];
1931 buf_vaddr_p = (gdb_byte *) &phdrp->p_vaddr;
1932 buf_paddr_p = (gdb_byte *) &phdrp->p_paddr;
1934 vaddr = extract_unsigned_integer (buf_vaddr_p, 8,
1936 displacement_vaddr = vaddr - phdr2[i].p_vaddr;
1938 paddr = extract_unsigned_integer (buf_paddr_p, 8,
1940 displacement_paddr = paddr - phdr2[i].p_paddr;
1942 if (displacement_vaddr == displacement_paddr)
1943 displacement = displacement_vaddr;
1948 /* Now compare BUF and BUF2 with optional DISPLACEMENT. */
1950 for (i = 0; i < phdrs_size / sizeof (Elf64_External_Phdr); i++)
1952 Elf64_External_Phdr *phdrp;
1953 Elf64_External_Phdr *phdr2p;
1954 gdb_byte *buf_vaddr_p, *buf_paddr_p;
1955 CORE_ADDR vaddr, paddr;
1956 asection *plt2_asect;
1958 phdrp = &((Elf64_External_Phdr *) buf)[i];
1959 buf_vaddr_p = (gdb_byte *) &phdrp->p_vaddr;
1960 buf_paddr_p = (gdb_byte *) &phdrp->p_paddr;
1961 phdr2p = &((Elf64_External_Phdr *) buf2)[i];
1963 /* PT_GNU_STACK is an exception by being never relocated by
1964 prelink as its addresses are always zero. */
1966 if (memcmp (phdrp, phdr2p, sizeof (*phdrp)) == 0)
1969 /* Check also other adjustment combinations - PR 11786. */
1971 vaddr = extract_unsigned_integer (buf_vaddr_p, 8, byte_order);
1972 vaddr -= displacement;
1973 store_unsigned_integer (buf_vaddr_p, 8, byte_order, vaddr);
1975 paddr = extract_unsigned_integer (buf_paddr_p, 8, byte_order);
1976 paddr -= displacement;
1977 store_unsigned_integer (buf_paddr_p, 8, byte_order, paddr);
1979 if (memcmp (phdrp, phdr2p, sizeof (*phdrp)) == 0)
1982 /* prelink can convert .plt SHT_NOBITS to SHT_PROGBITS. */
1983 plt2_asect = bfd_get_section_by_name (exec_bfd, ".plt");
1987 gdb_byte *buf_filesz_p = (gdb_byte *) &phdrp->p_filesz;
1990 content2 = (bfd_get_section_flags (exec_bfd, plt2_asect)
1991 & SEC_HAS_CONTENTS) != 0;
1993 filesz = extract_unsigned_integer (buf_filesz_p, 8,
1996 /* PLT2_ASECT is from on-disk file (exec_bfd) while
1997 FILESZ is from the in-memory image. */
1999 filesz += bfd_get_section_size (plt2_asect);
2001 filesz -= bfd_get_section_size (plt2_asect);
2003 store_unsigned_integer (buf_filesz_p, 8, byte_order,
2006 if (memcmp (phdrp, phdr2p, sizeof (*phdrp)) == 0)
2027 /* It can be printed repeatedly as there is no easy way to check
2028 the executable symbols/file has been already relocated to
2031 printf_unfiltered (_("Using PIE (Position Independent Executable) "
2032 "displacement %s for \"%s\".\n"),
2033 paddress (target_gdbarch, displacement),
2034 bfd_get_filename (exec_bfd));
2037 *displacementp = displacement;
2041 /* Relocate the main executable. This function should be called upon
2042 stopping the inferior process at the entry point to the program.
2043 The entry point from BFD is compared to the AT_ENTRY of AUXV and if they are
2044 different, the main executable is relocated by the proper amount. */
2047 svr4_relocate_main_executable (void)
2049 CORE_ADDR displacement;
2051 /* If we are re-running this executable, SYMFILE_OBJFILE->SECTION_OFFSETS
2052 probably contains the offsets computed using the PIE displacement
2053 from the previous run, which of course are irrelevant for this run.
2054 So we need to determine the new PIE displacement and recompute the
2055 section offsets accordingly, even if SYMFILE_OBJFILE->SECTION_OFFSETS
2056 already contains pre-computed offsets.
2058 If we cannot compute the PIE displacement, either:
2060 - The executable is not PIE.
2062 - SYMFILE_OBJFILE does not match the executable started in the target.
2063 This can happen for main executable symbols loaded at the host while
2064 `ld.so --ld-args main-executable' is loaded in the target.
2066 Then we leave the section offsets untouched and use them as is for
2069 - These section offsets were properly reset earlier, and thus
2070 already contain the correct values. This can happen for instance
2071 when reconnecting via the remote protocol to a target that supports
2072 the `qOffsets' packet.
2074 - The section offsets were not reset earlier, and the best we can
2075 hope is that the old offsets are still applicable to the new run.
2078 if (! svr4_exec_displacement (&displacement))
2081 /* Even DISPLACEMENT 0 is a valid new difference of in-memory vs. in-file
2084 if (symfile_objfile)
2086 struct section_offsets *new_offsets;
2089 new_offsets = alloca (symfile_objfile->num_sections
2090 * sizeof (*new_offsets));
2092 for (i = 0; i < symfile_objfile->num_sections; i++)
2093 new_offsets->offsets[i] = displacement;
2095 objfile_relocate (symfile_objfile, new_offsets);
2101 for (asect = exec_bfd->sections; asect != NULL; asect = asect->next)
2102 exec_set_section_address (bfd_get_filename (exec_bfd), asect->index,
2103 (bfd_section_vma (exec_bfd, asect)
2112 svr4_solib_create_inferior_hook -- shared library startup support
2116 void svr4_solib_create_inferior_hook (int from_tty)
2120 When gdb starts up the inferior, it nurses it along (through the
2121 shell) until it is ready to execute it's first instruction. At this
2122 point, this function gets called via expansion of the macro
2123 SOLIB_CREATE_INFERIOR_HOOK.
2125 For SunOS executables, this first instruction is typically the
2126 one at "_start", or a similar text label, regardless of whether
2127 the executable is statically or dynamically linked. The runtime
2128 startup code takes care of dynamically linking in any shared
2129 libraries, once gdb allows the inferior to continue.
2131 For SVR4 executables, this first instruction is either the first
2132 instruction in the dynamic linker (for dynamically linked
2133 executables) or the instruction at "start" for statically linked
2134 executables. For dynamically linked executables, the system
2135 first exec's /lib/libc.so.N, which contains the dynamic linker,
2136 and starts it running. The dynamic linker maps in any needed
2137 shared libraries, maps in the actual user executable, and then
2138 jumps to "start" in the user executable.
2140 For both SunOS shared libraries, and SVR4 shared libraries, we
2141 can arrange to cooperate with the dynamic linker to discover the
2142 names of shared libraries that are dynamically linked, and the
2143 base addresses to which they are linked.
2145 This function is responsible for discovering those names and
2146 addresses, and saving sufficient information about them to allow
2147 their symbols to be read at a later time.
2151 Between enable_break() and disable_break(), this code does not
2152 properly handle hitting breakpoints which the user might have
2153 set in the startup code or in the dynamic linker itself. Proper
2154 handling will probably have to wait until the implementation is
2155 changed to use the "breakpoint handler function" method.
2157 Also, what if child has exit()ed? Must exit loop somehow.
2161 svr4_solib_create_inferior_hook (int from_tty)
2163 #if defined(_SCO_DS)
2164 struct inferior *inf;
2165 struct thread_info *tp;
2166 #endif /* defined(_SCO_DS) */
2167 struct svr4_info *info;
2169 info = get_svr4_info ();
2171 /* Relocate the main executable if necessary. */
2172 svr4_relocate_main_executable ();
2174 if (!svr4_have_link_map_offsets ())
2177 if (!enable_break (info, from_tty))
2180 #if defined(_SCO_DS)
2181 /* SCO needs the loop below, other systems should be using the
2182 special shared library breakpoints and the shared library breakpoint
2185 Now run the target. It will eventually hit the breakpoint, at
2186 which point all of the libraries will have been mapped in and we
2187 can go groveling around in the dynamic linker structures to find
2188 out what we need to know about them. */
2190 inf = current_inferior ();
2191 tp = inferior_thread ();
2193 clear_proceed_status ();
2194 inf->control.stop_soon = STOP_QUIETLY;
2195 tp->suspend.stop_signal = TARGET_SIGNAL_0;
2198 target_resume (pid_to_ptid (-1), 0, tp->suspend.stop_signal);
2199 wait_for_inferior (0);
2201 while (tp->suspend.stop_signal != TARGET_SIGNAL_TRAP);
2202 inf->control.stop_soon = NO_STOP_QUIETLY;
2203 #endif /* defined(_SCO_DS) */
2207 svr4_clear_solib (void)
2209 struct svr4_info *info;
2211 info = get_svr4_info ();
2212 info->debug_base = 0;
2213 info->debug_loader_offset_p = 0;
2214 info->debug_loader_offset = 0;
2215 xfree (info->debug_loader_name);
2216 info->debug_loader_name = NULL;
2220 svr4_free_so (struct so_list *so)
2222 xfree (so->lm_info->lm);
2223 xfree (so->lm_info);
2227 /* Clear any bits of ADDR that wouldn't fit in a target-format
2228 data pointer. "Data pointer" here refers to whatever sort of
2229 address the dynamic linker uses to manage its sections. At the
2230 moment, we don't support shared libraries on any processors where
2231 code and data pointers are different sizes.
2233 This isn't really the right solution. What we really need here is
2234 a way to do arithmetic on CORE_ADDR values that respects the
2235 natural pointer/address correspondence. (For example, on the MIPS,
2236 converting a 32-bit pointer to a 64-bit CORE_ADDR requires you to
2237 sign-extend the value. There, simply truncating the bits above
2238 gdbarch_ptr_bit, as we do below, is no good.) This should probably
2239 be a new gdbarch method or something. */
2241 svr4_truncate_ptr (CORE_ADDR addr)
2243 if (gdbarch_ptr_bit (target_gdbarch) == sizeof (CORE_ADDR) * 8)
2244 /* We don't need to truncate anything, and the bit twiddling below
2245 will fail due to overflow problems. */
2248 return addr & (((CORE_ADDR) 1 << gdbarch_ptr_bit (target_gdbarch)) - 1);
2253 svr4_relocate_section_addresses (struct so_list *so,
2254 struct target_section *sec)
2256 sec->addr = svr4_truncate_ptr (sec->addr + LM_ADDR_CHECK (so,
2258 sec->endaddr = svr4_truncate_ptr (sec->endaddr + LM_ADDR_CHECK (so,
2263 /* Architecture-specific operations. */
2265 /* Per-architecture data key. */
2266 static struct gdbarch_data *solib_svr4_data;
2268 struct solib_svr4_ops
2270 /* Return a description of the layout of `struct link_map'. */
2271 struct link_map_offsets *(*fetch_link_map_offsets)(void);
2274 /* Return a default for the architecture-specific operations. */
2277 solib_svr4_init (struct obstack *obstack)
2279 struct solib_svr4_ops *ops;
2281 ops = OBSTACK_ZALLOC (obstack, struct solib_svr4_ops);
2282 ops->fetch_link_map_offsets = NULL;
2286 /* Set the architecture-specific `struct link_map_offsets' fetcher for
2287 GDBARCH to FLMO. Also, install SVR4 solib_ops into GDBARCH. */
2290 set_solib_svr4_fetch_link_map_offsets (struct gdbarch *gdbarch,
2291 struct link_map_offsets *(*flmo) (void))
2293 struct solib_svr4_ops *ops = gdbarch_data (gdbarch, solib_svr4_data);
2295 ops->fetch_link_map_offsets = flmo;
2297 set_solib_ops (gdbarch, &svr4_so_ops);
2300 /* Fetch a link_map_offsets structure using the architecture-specific
2301 `struct link_map_offsets' fetcher. */
2303 static struct link_map_offsets *
2304 svr4_fetch_link_map_offsets (void)
2306 struct solib_svr4_ops *ops = gdbarch_data (target_gdbarch, solib_svr4_data);
2308 gdb_assert (ops->fetch_link_map_offsets);
2309 return ops->fetch_link_map_offsets ();
2312 /* Return 1 if a link map offset fetcher has been defined, 0 otherwise. */
2315 svr4_have_link_map_offsets (void)
2317 struct solib_svr4_ops *ops = gdbarch_data (target_gdbarch, solib_svr4_data);
2319 return (ops->fetch_link_map_offsets != NULL);
2323 /* Most OS'es that have SVR4-style ELF dynamic libraries define a
2324 `struct r_debug' and a `struct link_map' that are binary compatible
2325 with the origional SVR4 implementation. */
2327 /* Fetch (and possibly build) an appropriate `struct link_map_offsets'
2328 for an ILP32 SVR4 system. */
2330 struct link_map_offsets *
2331 svr4_ilp32_fetch_link_map_offsets (void)
2333 static struct link_map_offsets lmo;
2334 static struct link_map_offsets *lmp = NULL;
2340 lmo.r_version_offset = 0;
2341 lmo.r_version_size = 4;
2342 lmo.r_map_offset = 4;
2343 lmo.r_brk_offset = 8;
2344 lmo.r_ldsomap_offset = 20;
2346 /* Everything we need is in the first 20 bytes. */
2347 lmo.link_map_size = 20;
2348 lmo.l_addr_offset = 0;
2349 lmo.l_name_offset = 4;
2350 lmo.l_ld_offset = 8;
2351 lmo.l_next_offset = 12;
2352 lmo.l_prev_offset = 16;
2358 /* Fetch (and possibly build) an appropriate `struct link_map_offsets'
2359 for an LP64 SVR4 system. */
2361 struct link_map_offsets *
2362 svr4_lp64_fetch_link_map_offsets (void)
2364 static struct link_map_offsets lmo;
2365 static struct link_map_offsets *lmp = NULL;
2371 lmo.r_version_offset = 0;
2372 lmo.r_version_size = 4;
2373 lmo.r_map_offset = 8;
2374 lmo.r_brk_offset = 16;
2375 lmo.r_ldsomap_offset = 40;
2377 /* Everything we need is in the first 40 bytes. */
2378 lmo.link_map_size = 40;
2379 lmo.l_addr_offset = 0;
2380 lmo.l_name_offset = 8;
2381 lmo.l_ld_offset = 16;
2382 lmo.l_next_offset = 24;
2383 lmo.l_prev_offset = 32;
2390 struct target_so_ops svr4_so_ops;
2392 /* Lookup global symbol for ELF DSOs linked with -Bsymbolic. Those DSOs have a
2393 different rule for symbol lookup. The lookup begins here in the DSO, not in
2394 the main executable. */
2396 static struct symbol *
2397 elf_lookup_lib_symbol (const struct objfile *objfile,
2399 const domain_enum domain)
2403 if (objfile == symfile_objfile)
2407 /* OBJFILE should have been passed as the non-debug one. */
2408 gdb_assert (objfile->separate_debug_objfile_backlink == NULL);
2410 abfd = objfile->obfd;
2413 if (abfd == NULL || scan_dyntag (DT_SYMBOLIC, abfd, NULL) != 1)
2416 return lookup_global_symbol_from_objfile (objfile, name, domain);
2419 extern initialize_file_ftype _initialize_svr4_solib; /* -Wmissing-prototypes */
2422 _initialize_svr4_solib (void)
2424 solib_svr4_data = gdbarch_data_register_pre_init (solib_svr4_init);
2425 solib_svr4_pspace_data
2426 = register_program_space_data_with_cleanup (svr4_pspace_data_cleanup);
2428 svr4_so_ops.relocate_section_addresses = svr4_relocate_section_addresses;
2429 svr4_so_ops.free_so = svr4_free_so;
2430 svr4_so_ops.clear_solib = svr4_clear_solib;
2431 svr4_so_ops.solib_create_inferior_hook = svr4_solib_create_inferior_hook;
2432 svr4_so_ops.special_symbol_handling = svr4_special_symbol_handling;
2433 svr4_so_ops.current_sos = svr4_current_sos;
2434 svr4_so_ops.open_symbol_file_object = open_symbol_file_object;
2435 svr4_so_ops.in_dynsym_resolve_code = svr4_in_dynsym_resolve_code;
2436 svr4_so_ops.bfd_open = solib_bfd_open;
2437 svr4_so_ops.lookup_lib_global_symbol = elf_lookup_lib_symbol;
2438 svr4_so_ops.same = svr4_same;
2439 svr4_so_ops.keep_data_in_core = svr4_keep_data_in_core;