1 /* Handle SVR4 shared libraries for GDB, the GNU Debugger.
3 Copyright (C) 1990-2019 Free Software Foundation, Inc.
5 This file is part of GDB.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>. */
22 #include "elf/external.h"
23 #include "elf/common.h"
35 #include "gdbthread.h"
36 #include "observable.h"
40 #include "solib-svr4.h"
42 #include "bfd-target.h"
49 static struct link_map_offsets *svr4_fetch_link_map_offsets (void);
50 static int svr4_have_link_map_offsets (void);
51 static void svr4_relocate_main_executable (void);
52 static void svr4_free_library_list (void *p_list);
54 /* On SVR4 systems, a list of symbols in the dynamic linker where
55 GDB can try to place a breakpoint to monitor shared library
58 If none of these symbols are found, or other errors occur, then
59 SVR4 systems will fall back to using a symbol as the "startup
60 mapping complete" breakpoint address. */
62 static const char * const solib_break_names[] =
68 "__dl_rtld_db_dlactivity",
74 static const char * const bkpt_names[] =
82 static const char * const main_name_list[] =
88 /* What to do when a probe stop occurs. */
92 /* Something went seriously wrong. Stop using probes and
93 revert to using the older interface. */
94 PROBES_INTERFACE_FAILED,
96 /* No action is required. The shared object list is still
100 /* The shared object list should be reloaded entirely. */
103 /* Attempt to incrementally update the shared object list. If
104 the update fails or is not possible, fall back to reloading
109 /* A probe's name and its associated action. */
113 /* The name of the probe. */
116 /* What to do when a probe stop occurs. */
117 enum probe_action action;
120 /* A list of named probes and their associated actions. If all
121 probes are present in the dynamic linker then the probes-based
122 interface will be used. */
124 static const struct probe_info probe_info[] =
126 { "init_start", DO_NOTHING },
127 { "init_complete", FULL_RELOAD },
128 { "map_start", DO_NOTHING },
129 { "map_failed", DO_NOTHING },
130 { "reloc_complete", UPDATE_OR_RELOAD },
131 { "unmap_start", DO_NOTHING },
132 { "unmap_complete", FULL_RELOAD },
135 #define NUM_PROBES ARRAY_SIZE (probe_info)
137 /* Return non-zero if GDB_SO_NAME and INFERIOR_SO_NAME represent
138 the same shared library. */
141 svr4_same_1 (const char *gdb_so_name, const char *inferior_so_name)
143 if (strcmp (gdb_so_name, inferior_so_name) == 0)
146 /* On Solaris, when starting inferior we think that dynamic linker is
147 /usr/lib/ld.so.1, but later on, the table of loaded shared libraries
148 contains /lib/ld.so.1. Sometimes one file is a link to another, but
149 sometimes they have identical content, but are not linked to each
150 other. We don't restrict this check for Solaris, but the chances
151 of running into this situation elsewhere are very low. */
152 if (strcmp (gdb_so_name, "/usr/lib/ld.so.1") == 0
153 && strcmp (inferior_so_name, "/lib/ld.so.1") == 0)
156 /* Similarly, we observed the same issue with amd64 and sparcv9, but with
157 different locations. */
158 if (strcmp (gdb_so_name, "/usr/lib/amd64/ld.so.1") == 0
159 && strcmp (inferior_so_name, "/lib/amd64/ld.so.1") == 0)
162 if (strcmp (gdb_so_name, "/usr/lib/sparcv9/ld.so.1") == 0
163 && strcmp (inferior_so_name, "/lib/sparcv9/ld.so.1") == 0)
170 svr4_same (struct so_list *gdb, struct so_list *inferior)
172 return (svr4_same_1 (gdb->so_original_name, inferior->so_original_name));
175 static std::unique_ptr<lm_info_svr4>
176 lm_info_read (CORE_ADDR lm_addr)
178 struct link_map_offsets *lmo = svr4_fetch_link_map_offsets ();
179 std::unique_ptr<lm_info_svr4> lm_info;
181 gdb::byte_vector lm (lmo->link_map_size);
183 if (target_read_memory (lm_addr, lm.data (), lmo->link_map_size) != 0)
184 warning (_("Error reading shared library list entry at %s"),
185 paddress (target_gdbarch (), lm_addr));
188 struct type *ptr_type = builtin_type (target_gdbarch ())->builtin_data_ptr;
190 lm_info.reset (new lm_info_svr4);
191 lm_info->lm_addr = lm_addr;
193 lm_info->l_addr_inferior = extract_typed_address (&lm[lmo->l_addr_offset],
195 lm_info->l_ld = extract_typed_address (&lm[lmo->l_ld_offset], ptr_type);
196 lm_info->l_next = extract_typed_address (&lm[lmo->l_next_offset],
198 lm_info->l_prev = extract_typed_address (&lm[lmo->l_prev_offset],
200 lm_info->l_name = extract_typed_address (&lm[lmo->l_name_offset],
208 has_lm_dynamic_from_link_map (void)
210 struct link_map_offsets *lmo = svr4_fetch_link_map_offsets ();
212 return lmo->l_ld_offset >= 0;
216 lm_addr_check (const struct so_list *so, bfd *abfd)
218 lm_info_svr4 *li = (lm_info_svr4 *) so->lm_info;
222 struct bfd_section *dyninfo_sect;
223 CORE_ADDR l_addr, l_dynaddr, dynaddr;
225 l_addr = li->l_addr_inferior;
227 if (! abfd || ! has_lm_dynamic_from_link_map ())
230 l_dynaddr = li->l_ld;
232 dyninfo_sect = bfd_get_section_by_name (abfd, ".dynamic");
233 if (dyninfo_sect == NULL)
236 dynaddr = bfd_section_vma (abfd, dyninfo_sect);
238 if (dynaddr + l_addr != l_dynaddr)
240 CORE_ADDR align = 0x1000;
241 CORE_ADDR minpagesize = align;
243 if (bfd_get_flavour (abfd) == bfd_target_elf_flavour)
245 Elf_Internal_Ehdr *ehdr = elf_tdata (abfd)->elf_header;
246 Elf_Internal_Phdr *phdr = elf_tdata (abfd)->phdr;
251 for (i = 0; i < ehdr->e_phnum; i++)
252 if (phdr[i].p_type == PT_LOAD && phdr[i].p_align > align)
253 align = phdr[i].p_align;
255 minpagesize = get_elf_backend_data (abfd)->minpagesize;
258 /* Turn it into a mask. */
261 /* If the changes match the alignment requirements, we
262 assume we're using a core file that was generated by the
263 same binary, just prelinked with a different base offset.
264 If it doesn't match, we may have a different binary, the
265 same binary with the dynamic table loaded at an unrelated
266 location, or anything, really. To avoid regressions,
267 don't adjust the base offset in the latter case, although
268 odds are that, if things really changed, debugging won't
271 One could expect more the condition
272 ((l_addr & align) == 0 && ((l_dynaddr - dynaddr) & align) == 0)
273 but the one below is relaxed for PPC. The PPC kernel supports
274 either 4k or 64k page sizes. To be prepared for 64k pages,
275 PPC ELF files are built using an alignment requirement of 64k.
276 However, when running on a kernel supporting 4k pages, the memory
277 mapping of the library may not actually happen on a 64k boundary!
279 (In the usual case where (l_addr & align) == 0, this check is
280 equivalent to the possibly expected check above.)
282 Even on PPC it must be zero-aligned at least for MINPAGESIZE. */
284 l_addr = l_dynaddr - dynaddr;
286 if ((l_addr & (minpagesize - 1)) == 0
287 && (l_addr & align) == ((l_dynaddr - dynaddr) & align))
290 printf_unfiltered (_("Using PIC (Position Independent Code) "
291 "prelink displacement %s for \"%s\".\n"),
292 paddress (target_gdbarch (), l_addr),
297 /* There is no way to verify the library file matches. prelink
298 can during prelinking of an unprelinked file (or unprelinking
299 of a prelinked file) shift the DYNAMIC segment by arbitrary
300 offset without any page size alignment. There is no way to
301 find out the ELF header and/or Program Headers for a limited
302 verification if it they match. One could do a verification
303 of the DYNAMIC segment. Still the found address is the best
304 one GDB could find. */
306 warning (_(".dynamic section for \"%s\" "
307 "is not at the expected address "
308 "(wrong library or version mismatch?)"), so->so_name);
320 /* Per pspace SVR4 specific data. */
324 CORE_ADDR debug_base; /* Base of dynamic linker structures. */
326 /* Validity flag for debug_loader_offset. */
327 int debug_loader_offset_p;
329 /* Load address for the dynamic linker, inferred. */
330 CORE_ADDR debug_loader_offset;
332 /* Name of the dynamic linker, valid if debug_loader_offset_p. */
333 char *debug_loader_name;
335 /* Load map address for the main executable. */
336 CORE_ADDR main_lm_addr;
338 CORE_ADDR interp_text_sect_low;
339 CORE_ADDR interp_text_sect_high;
340 CORE_ADDR interp_plt_sect_low;
341 CORE_ADDR interp_plt_sect_high;
343 /* Nonzero if the list of objects was last obtained from the target
344 via qXfer:libraries-svr4:read. */
347 /* Table of struct probe_and_action instances, used by the
348 probes-based interface to map breakpoint addresses to probes
349 and their associated actions. Lookup is performed using
350 probe_and_action->prob->address. */
353 /* List of objects loaded into the inferior, used by the probes-
355 struct so_list *solib_list;
358 /* Per-program-space data key. */
359 static const struct program_space_data *solib_svr4_pspace_data;
361 /* Free the probes table. */
364 free_probes_table (struct svr4_info *info)
366 if (info->probes_table == NULL)
369 htab_delete (info->probes_table);
370 info->probes_table = NULL;
373 /* Free the solib list. */
376 free_solib_list (struct svr4_info *info)
378 svr4_free_library_list (&info->solib_list);
379 info->solib_list = NULL;
383 svr4_pspace_data_cleanup (struct program_space *pspace, void *arg)
385 struct svr4_info *info = (struct svr4_info *) arg;
387 free_probes_table (info);
388 free_solib_list (info);
393 /* Get the current svr4 data. If none is found yet, add it now. This
394 function always returns a valid object. */
396 static struct svr4_info *
399 struct svr4_info *info;
401 info = (struct svr4_info *) program_space_data (current_program_space,
402 solib_svr4_pspace_data);
406 info = XCNEW (struct svr4_info);
407 set_program_space_data (current_program_space, solib_svr4_pspace_data, info);
411 /* Local function prototypes */
413 static int match_main (const char *);
415 /* Read program header TYPE from inferior memory. The header is found
416 by scanning the OS auxiliary vector.
418 If TYPE == -1, return the program headers instead of the contents of
421 Return vector of bytes holding the program header contents, or an empty
422 optional on failure. If successful and P_ARCH_SIZE is non-NULL, the target
423 architecture size (32-bit or 64-bit) is returned to *P_ARCH_SIZE. Likewise,
424 the base address of the section is returned in *BASE_ADDR. */
426 static gdb::optional<gdb::byte_vector>
427 read_program_header (int type, int *p_arch_size, CORE_ADDR *base_addr)
429 enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ());
430 CORE_ADDR at_phdr, at_phent, at_phnum, pt_phdr = 0;
431 int arch_size, sect_size;
435 /* Get required auxv elements from target. */
436 if (target_auxv_search (current_top_target (), AT_PHDR, &at_phdr) <= 0)
438 if (target_auxv_search (current_top_target (), AT_PHENT, &at_phent) <= 0)
440 if (target_auxv_search (current_top_target (), AT_PHNUM, &at_phnum) <= 0)
442 if (!at_phdr || !at_phnum)
445 /* Determine ELF architecture type. */
446 if (at_phent == sizeof (Elf32_External_Phdr))
448 else if (at_phent == sizeof (Elf64_External_Phdr))
453 /* Find the requested segment. */
457 sect_size = at_phent * at_phnum;
459 else if (arch_size == 32)
461 Elf32_External_Phdr phdr;
464 /* Search for requested PHDR. */
465 for (i = 0; i < at_phnum; i++)
469 if (target_read_memory (at_phdr + i * sizeof (phdr),
470 (gdb_byte *)&phdr, sizeof (phdr)))
473 p_type = extract_unsigned_integer ((gdb_byte *) phdr.p_type,
476 if (p_type == PT_PHDR)
479 pt_phdr = extract_unsigned_integer ((gdb_byte *) phdr.p_vaddr,
490 /* Retrieve address and size. */
491 sect_addr = extract_unsigned_integer ((gdb_byte *)phdr.p_vaddr,
493 sect_size = extract_unsigned_integer ((gdb_byte *)phdr.p_memsz,
498 Elf64_External_Phdr phdr;
501 /* Search for requested PHDR. */
502 for (i = 0; i < at_phnum; i++)
506 if (target_read_memory (at_phdr + i * sizeof (phdr),
507 (gdb_byte *)&phdr, sizeof (phdr)))
510 p_type = extract_unsigned_integer ((gdb_byte *) phdr.p_type,
513 if (p_type == PT_PHDR)
516 pt_phdr = extract_unsigned_integer ((gdb_byte *) phdr.p_vaddr,
527 /* Retrieve address and size. */
528 sect_addr = extract_unsigned_integer ((gdb_byte *)phdr.p_vaddr,
530 sect_size = extract_unsigned_integer ((gdb_byte *)phdr.p_memsz,
534 /* PT_PHDR is optional, but we really need it
535 for PIE to make this work in general. */
539 /* at_phdr is real address in memory. pt_phdr is what pheader says it is.
540 Relocation offset is the difference between the two. */
541 sect_addr = sect_addr + (at_phdr - pt_phdr);
544 /* Read in requested program header. */
545 gdb::byte_vector buf (sect_size);
546 if (target_read_memory (sect_addr, buf.data (), sect_size))
550 *p_arch_size = arch_size;
552 *base_addr = sect_addr;
558 /* Return program interpreter string. */
559 static gdb::optional<gdb::byte_vector>
560 find_program_interpreter (void)
562 /* If we have an exec_bfd, use its section table. */
564 && bfd_get_flavour (exec_bfd) == bfd_target_elf_flavour)
566 struct bfd_section *interp_sect;
568 interp_sect = bfd_get_section_by_name (exec_bfd, ".interp");
569 if (interp_sect != NULL)
571 int sect_size = bfd_section_size (exec_bfd, interp_sect);
573 gdb::byte_vector buf (sect_size);
574 bfd_get_section_contents (exec_bfd, interp_sect, buf.data (), 0,
580 /* If we didn't find it, use the target auxiliary vector. */
581 return read_program_header (PT_INTERP, NULL, NULL);
585 /* Scan for DESIRED_DYNTAG in .dynamic section of ABFD. If DESIRED_DYNTAG is
586 found, 1 is returned and the corresponding PTR is set. */
589 scan_dyntag (const int desired_dyntag, bfd *abfd, CORE_ADDR *ptr,
592 int arch_size, step, sect_size;
594 CORE_ADDR dyn_ptr, dyn_addr;
595 gdb_byte *bufend, *bufstart, *buf;
596 Elf32_External_Dyn *x_dynp_32;
597 Elf64_External_Dyn *x_dynp_64;
598 struct bfd_section *sect;
599 struct target_section *target_section;
604 if (bfd_get_flavour (abfd) != bfd_target_elf_flavour)
607 arch_size = bfd_get_arch_size (abfd);
611 /* Find the start address of the .dynamic section. */
612 sect = bfd_get_section_by_name (abfd, ".dynamic");
616 for (target_section = current_target_sections->sections;
617 target_section < current_target_sections->sections_end;
619 if (sect == target_section->the_bfd_section)
621 if (target_section < current_target_sections->sections_end)
622 dyn_addr = target_section->addr;
625 /* ABFD may come from OBJFILE acting only as a symbol file without being
626 loaded into the target (see add_symbol_file_command). This case is
627 such fallback to the file VMA address without the possibility of
628 having the section relocated to its actual in-memory address. */
630 dyn_addr = bfd_section_vma (abfd, sect);
633 /* Read in .dynamic from the BFD. We will get the actual value
634 from memory later. */
635 sect_size = bfd_section_size (abfd, sect);
636 buf = bufstart = (gdb_byte *) alloca (sect_size);
637 if (!bfd_get_section_contents (abfd, sect,
641 /* Iterate over BUF and scan for DYNTAG. If found, set PTR and return. */
642 step = (arch_size == 32) ? sizeof (Elf32_External_Dyn)
643 : sizeof (Elf64_External_Dyn);
644 for (bufend = buf + sect_size;
650 x_dynp_32 = (Elf32_External_Dyn *) buf;
651 current_dyntag = bfd_h_get_32 (abfd, (bfd_byte *) x_dynp_32->d_tag);
652 dyn_ptr = bfd_h_get_32 (abfd, (bfd_byte *) x_dynp_32->d_un.d_ptr);
656 x_dynp_64 = (Elf64_External_Dyn *) buf;
657 current_dyntag = bfd_h_get_64 (abfd, (bfd_byte *) x_dynp_64->d_tag);
658 dyn_ptr = bfd_h_get_64 (abfd, (bfd_byte *) x_dynp_64->d_un.d_ptr);
660 if (current_dyntag == DT_NULL)
662 if (current_dyntag == desired_dyntag)
664 /* If requested, try to read the runtime value of this .dynamic
668 struct type *ptr_type;
670 CORE_ADDR ptr_addr_1;
672 ptr_type = builtin_type (target_gdbarch ())->builtin_data_ptr;
673 ptr_addr_1 = dyn_addr + (buf - bufstart) + arch_size / 8;
674 if (target_read_memory (ptr_addr_1, ptr_buf, arch_size / 8) == 0)
675 dyn_ptr = extract_typed_address (ptr_buf, ptr_type);
678 *ptr_addr = dyn_addr + (buf - bufstart);
687 /* Scan for DESIRED_DYNTAG in .dynamic section of the target's main executable,
688 found by consulting the OS auxillary vector. If DESIRED_DYNTAG is found, 1
689 is returned and the corresponding PTR is set. */
692 scan_dyntag_auxv (const int desired_dyntag, CORE_ADDR *ptr,
695 enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ());
701 /* Read in .dynamic section. */
702 gdb::optional<gdb::byte_vector> ph_data
703 = read_program_header (PT_DYNAMIC, &arch_size, &base_addr);
707 /* Iterate over BUF and scan for DYNTAG. If found, set PTR and return. */
708 step = (arch_size == 32) ? sizeof (Elf32_External_Dyn)
709 : sizeof (Elf64_External_Dyn);
710 for (gdb_byte *buf = ph_data->data (), *bufend = buf + ph_data->size ();
711 buf < bufend; buf += step)
715 Elf32_External_Dyn *dynp = (Elf32_External_Dyn *) buf;
717 current_dyntag = extract_unsigned_integer ((gdb_byte *) dynp->d_tag,
719 dyn_ptr = extract_unsigned_integer ((gdb_byte *) dynp->d_un.d_ptr,
724 Elf64_External_Dyn *dynp = (Elf64_External_Dyn *) buf;
726 current_dyntag = extract_unsigned_integer ((gdb_byte *) dynp->d_tag,
728 dyn_ptr = extract_unsigned_integer ((gdb_byte *) dynp->d_un.d_ptr,
731 if (current_dyntag == DT_NULL)
734 if (current_dyntag == desired_dyntag)
740 *ptr_addr = base_addr + buf - ph_data->data ();
749 /* Locate the base address of dynamic linker structs for SVR4 elf
752 For SVR4 elf targets the address of the dynamic linker's runtime
753 structure is contained within the dynamic info section in the
754 executable file. The dynamic section is also mapped into the
755 inferior address space. Because the runtime loader fills in the
756 real address before starting the inferior, we have to read in the
757 dynamic info section from the inferior address space.
758 If there are any errors while trying to find the address, we
759 silently return 0, otherwise the found address is returned. */
762 elf_locate_base (void)
764 struct bound_minimal_symbol msymbol;
765 CORE_ADDR dyn_ptr, dyn_ptr_addr;
767 /* Look for DT_MIPS_RLD_MAP first. MIPS executables use this
768 instead of DT_DEBUG, although they sometimes contain an unused
770 if (scan_dyntag (DT_MIPS_RLD_MAP, exec_bfd, &dyn_ptr, NULL)
771 || scan_dyntag_auxv (DT_MIPS_RLD_MAP, &dyn_ptr, NULL))
773 struct type *ptr_type = builtin_type (target_gdbarch ())->builtin_data_ptr;
775 int pbuf_size = TYPE_LENGTH (ptr_type);
777 pbuf = (gdb_byte *) alloca (pbuf_size);
778 /* DT_MIPS_RLD_MAP contains a pointer to the address
779 of the dynamic link structure. */
780 if (target_read_memory (dyn_ptr, pbuf, pbuf_size))
782 return extract_typed_address (pbuf, ptr_type);
785 /* Then check DT_MIPS_RLD_MAP_REL. MIPS executables now use this form
786 because of needing to support PIE. DT_MIPS_RLD_MAP will also exist
788 if (scan_dyntag (DT_MIPS_RLD_MAP_REL, exec_bfd, &dyn_ptr, &dyn_ptr_addr)
789 || scan_dyntag_auxv (DT_MIPS_RLD_MAP_REL, &dyn_ptr, &dyn_ptr_addr))
791 struct type *ptr_type = builtin_type (target_gdbarch ())->builtin_data_ptr;
793 int pbuf_size = TYPE_LENGTH (ptr_type);
795 pbuf = (gdb_byte *) alloca (pbuf_size);
796 /* DT_MIPS_RLD_MAP_REL contains an offset from the address of the
797 DT slot to the address of the dynamic link structure. */
798 if (target_read_memory (dyn_ptr + dyn_ptr_addr, pbuf, pbuf_size))
800 return extract_typed_address (pbuf, ptr_type);
804 if (scan_dyntag (DT_DEBUG, exec_bfd, &dyn_ptr, NULL)
805 || scan_dyntag_auxv (DT_DEBUG, &dyn_ptr, NULL))
808 /* This may be a static executable. Look for the symbol
809 conventionally named _r_debug, as a last resort. */
810 msymbol = lookup_minimal_symbol ("_r_debug", NULL, symfile_objfile);
811 if (msymbol.minsym != NULL)
812 return BMSYMBOL_VALUE_ADDRESS (msymbol);
814 /* DT_DEBUG entry not found. */
818 /* Locate the base address of dynamic linker structs.
820 For both the SunOS and SVR4 shared library implementations, if the
821 inferior executable has been linked dynamically, there is a single
822 address somewhere in the inferior's data space which is the key to
823 locating all of the dynamic linker's runtime structures. This
824 address is the value of the debug base symbol. The job of this
825 function is to find and return that address, or to return 0 if there
826 is no such address (the executable is statically linked for example).
828 For SunOS, the job is almost trivial, since the dynamic linker and
829 all of it's structures are statically linked to the executable at
830 link time. Thus the symbol for the address we are looking for has
831 already been added to the minimal symbol table for the executable's
832 objfile at the time the symbol file's symbols were read, and all we
833 have to do is look it up there. Note that we explicitly do NOT want
834 to find the copies in the shared library.
836 The SVR4 version is a bit more complicated because the address
837 is contained somewhere in the dynamic info section. We have to go
838 to a lot more work to discover the address of the debug base symbol.
839 Because of this complexity, we cache the value we find and return that
840 value on subsequent invocations. Note there is no copy in the
841 executable symbol tables. */
844 locate_base (struct svr4_info *info)
846 /* Check to see if we have a currently valid address, and if so, avoid
847 doing all this work again and just return the cached address. If
848 we have no cached address, try to locate it in the dynamic info
849 section for ELF executables. There's no point in doing any of this
850 though if we don't have some link map offsets to work with. */
852 if (info->debug_base == 0 && svr4_have_link_map_offsets ())
853 info->debug_base = elf_locate_base ();
854 return info->debug_base;
857 /* Find the first element in the inferior's dynamic link map, and
858 return its address in the inferior. Return zero if the address
859 could not be determined.
861 FIXME: Perhaps we should validate the info somehow, perhaps by
862 checking r_version for a known version number, or r_state for
866 solib_svr4_r_map (struct svr4_info *info)
868 struct link_map_offsets *lmo = svr4_fetch_link_map_offsets ();
869 struct type *ptr_type = builtin_type (target_gdbarch ())->builtin_data_ptr;
874 addr = read_memory_typed_address (info->debug_base + lmo->r_map_offset,
877 CATCH (ex, RETURN_MASK_ERROR)
879 exception_print (gdb_stderr, ex);
886 /* Find r_brk from the inferior's debug base. */
889 solib_svr4_r_brk (struct svr4_info *info)
891 struct link_map_offsets *lmo = svr4_fetch_link_map_offsets ();
892 struct type *ptr_type = builtin_type (target_gdbarch ())->builtin_data_ptr;
894 return read_memory_typed_address (info->debug_base + lmo->r_brk_offset,
898 /* Find the link map for the dynamic linker (if it is not in the
899 normal list of loaded shared objects). */
902 solib_svr4_r_ldsomap (struct svr4_info *info)
904 struct link_map_offsets *lmo = svr4_fetch_link_map_offsets ();
905 struct type *ptr_type = builtin_type (target_gdbarch ())->builtin_data_ptr;
906 enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ());
907 ULONGEST version = 0;
911 /* Check version, and return zero if `struct r_debug' doesn't have
912 the r_ldsomap member. */
914 = read_memory_unsigned_integer (info->debug_base + lmo->r_version_offset,
915 lmo->r_version_size, byte_order);
917 CATCH (ex, RETURN_MASK_ERROR)
919 exception_print (gdb_stderr, ex);
923 if (version < 2 || lmo->r_ldsomap_offset == -1)
926 return read_memory_typed_address (info->debug_base + lmo->r_ldsomap_offset,
930 /* On Solaris systems with some versions of the dynamic linker,
931 ld.so's l_name pointer points to the SONAME in the string table
932 rather than into writable memory. So that GDB can find shared
933 libraries when loading a core file generated by gcore, ensure that
934 memory areas containing the l_name string are saved in the core
938 svr4_keep_data_in_core (CORE_ADDR vaddr, unsigned long size)
940 struct svr4_info *info;
944 info = get_svr4_info ();
946 info->debug_base = 0;
948 if (!info->debug_base)
951 ldsomap = solib_svr4_r_ldsomap (info);
955 std::unique_ptr<lm_info_svr4> li = lm_info_read (ldsomap);
956 name_lm = li != NULL ? li->l_name : 0;
958 return (name_lm >= vaddr && name_lm < vaddr + size);
964 open_symbol_file_object (int from_tty)
966 CORE_ADDR lm, l_name;
967 gdb::unique_xmalloc_ptr<char> filename;
969 struct link_map_offsets *lmo = svr4_fetch_link_map_offsets ();
970 struct type *ptr_type = builtin_type (target_gdbarch ())->builtin_data_ptr;
971 int l_name_size = TYPE_LENGTH (ptr_type);
972 gdb::byte_vector l_name_buf (l_name_size);
973 struct svr4_info *info = get_svr4_info ();
974 symfile_add_flags add_flags = 0;
977 add_flags |= SYMFILE_VERBOSE;
980 if (!query (_("Attempt to reload symbols from process? ")))
983 /* Always locate the debug struct, in case it has moved. */
984 info->debug_base = 0;
985 if (locate_base (info) == 0)
986 return 0; /* failed somehow... */
988 /* First link map member should be the executable. */
989 lm = solib_svr4_r_map (info);
991 return 0; /* failed somehow... */
993 /* Read address of name from target memory to GDB. */
994 read_memory (lm + lmo->l_name_offset, l_name_buf.data (), l_name_size);
996 /* Convert the address to host format. */
997 l_name = extract_typed_address (l_name_buf.data (), ptr_type);
1000 return 0; /* No filename. */
1002 /* Now fetch the filename from target memory. */
1003 target_read_string (l_name, &filename, SO_NAME_MAX_PATH_SIZE - 1, &errcode);
1007 warning (_("failed to read exec filename from attached file: %s"),
1008 safe_strerror (errcode));
1012 /* Have a pathname: read the symbol file. */
1013 symbol_file_add_main (filename.get (), add_flags);
1018 /* Data exchange structure for the XML parser as returned by
1019 svr4_current_sos_via_xfer_libraries. */
1021 struct svr4_library_list
1023 struct so_list *head, **tailp;
1025 /* Inferior address of struct link_map used for the main executable. It is
1026 NULL if not known. */
1030 /* Implementation for target_so_ops.free_so. */
1033 svr4_free_so (struct so_list *so)
1035 lm_info_svr4 *li = (lm_info_svr4 *) so->lm_info;
1040 /* Implement target_so_ops.clear_so. */
1043 svr4_clear_so (struct so_list *so)
1045 lm_info_svr4 *li = (lm_info_svr4 *) so->lm_info;
1051 /* Free so_list built so far (called via cleanup). */
1054 svr4_free_library_list (void *p_list)
1056 struct so_list *list = *(struct so_list **) p_list;
1058 while (list != NULL)
1060 struct so_list *next = list->next;
1067 /* Copy library list. */
1069 static struct so_list *
1070 svr4_copy_library_list (struct so_list *src)
1072 struct so_list *dst = NULL;
1073 struct so_list **link = &dst;
1077 struct so_list *newobj;
1079 newobj = XNEW (struct so_list);
1080 memcpy (newobj, src, sizeof (struct so_list));
1082 lm_info_svr4 *src_li = (lm_info_svr4 *) src->lm_info;
1083 newobj->lm_info = new lm_info_svr4 (*src_li);
1085 newobj->next = NULL;
1087 link = &newobj->next;
1095 #ifdef HAVE_LIBEXPAT
1097 #include "xml-support.h"
1099 /* Handle the start of a <library> element. Note: new elements are added
1100 at the tail of the list, keeping the list in order. */
1103 library_list_start_library (struct gdb_xml_parser *parser,
1104 const struct gdb_xml_element *element,
1106 std::vector<gdb_xml_value> &attributes)
1108 struct svr4_library_list *list = (struct svr4_library_list *) user_data;
1110 = (const char *) xml_find_attribute (attributes, "name")->value.get ();
1112 = (ULONGEST *) xml_find_attribute (attributes, "lm")->value.get ();
1114 = (ULONGEST *) xml_find_attribute (attributes, "l_addr")->value.get ();
1116 = (ULONGEST *) xml_find_attribute (attributes, "l_ld")->value.get ();
1117 struct so_list *new_elem;
1119 new_elem = XCNEW (struct so_list);
1120 lm_info_svr4 *li = new lm_info_svr4;
1121 new_elem->lm_info = li;
1123 li->l_addr_inferior = *l_addrp;
1126 strncpy (new_elem->so_name, name, sizeof (new_elem->so_name) - 1);
1127 new_elem->so_name[sizeof (new_elem->so_name) - 1] = 0;
1128 strcpy (new_elem->so_original_name, new_elem->so_name);
1130 *list->tailp = new_elem;
1131 list->tailp = &new_elem->next;
1134 /* Handle the start of a <library-list-svr4> element. */
1137 svr4_library_list_start_list (struct gdb_xml_parser *parser,
1138 const struct gdb_xml_element *element,
1140 std::vector<gdb_xml_value> &attributes)
1142 struct svr4_library_list *list = (struct svr4_library_list *) user_data;
1144 = (const char *) xml_find_attribute (attributes, "version")->value.get ();
1145 struct gdb_xml_value *main_lm = xml_find_attribute (attributes, "main-lm");
1147 if (strcmp (version, "1.0") != 0)
1148 gdb_xml_error (parser,
1149 _("SVR4 Library list has unsupported version \"%s\""),
1153 list->main_lm = *(ULONGEST *) main_lm->value.get ();
1156 /* The allowed elements and attributes for an XML library list.
1157 The root element is a <library-list>. */
1159 static const struct gdb_xml_attribute svr4_library_attributes[] =
1161 { "name", GDB_XML_AF_NONE, NULL, NULL },
1162 { "lm", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL },
1163 { "l_addr", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL },
1164 { "l_ld", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL },
1165 { NULL, GDB_XML_AF_NONE, NULL, NULL }
1168 static const struct gdb_xml_element svr4_library_list_children[] =
1171 "library", svr4_library_attributes, NULL,
1172 GDB_XML_EF_REPEATABLE | GDB_XML_EF_OPTIONAL,
1173 library_list_start_library, NULL
1175 { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
1178 static const struct gdb_xml_attribute svr4_library_list_attributes[] =
1180 { "version", GDB_XML_AF_NONE, NULL, NULL },
1181 { "main-lm", GDB_XML_AF_OPTIONAL, gdb_xml_parse_attr_ulongest, NULL },
1182 { NULL, GDB_XML_AF_NONE, NULL, NULL }
1185 static const struct gdb_xml_element svr4_library_list_elements[] =
1187 { "library-list-svr4", svr4_library_list_attributes, svr4_library_list_children,
1188 GDB_XML_EF_NONE, svr4_library_list_start_list, NULL },
1189 { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
1192 /* Parse qXfer:libraries:read packet into *SO_LIST_RETURN. Return 1 if
1194 Return 0 if packet not supported, *SO_LIST_RETURN is not modified in such
1195 case. Return 1 if *SO_LIST_RETURN contains the library list, it may be
1196 empty, caller is responsible for freeing all its entries. */
1199 svr4_parse_libraries (const char *document, struct svr4_library_list *list)
1201 struct cleanup *back_to = make_cleanup (svr4_free_library_list,
1204 memset (list, 0, sizeof (*list));
1205 list->tailp = &list->head;
1206 if (gdb_xml_parse_quick (_("target library list"), "library-list-svr4.dtd",
1207 svr4_library_list_elements, document, list) == 0)
1209 /* Parsed successfully, keep the result. */
1210 discard_cleanups (back_to);
1214 do_cleanups (back_to);
1218 /* Attempt to get so_list from target via qXfer:libraries-svr4:read packet.
1220 Return 0 if packet not supported, *SO_LIST_RETURN is not modified in such
1221 case. Return 1 if *SO_LIST_RETURN contains the library list, it may be
1222 empty, caller is responsible for freeing all its entries.
1224 Note that ANNEX must be NULL if the remote does not explicitly allow
1225 qXfer:libraries-svr4:read packets with non-empty annexes. Support for
1226 this can be checked using target_augmented_libraries_svr4_read (). */
1229 svr4_current_sos_via_xfer_libraries (struct svr4_library_list *list,
1232 gdb_assert (annex == NULL || target_augmented_libraries_svr4_read ());
1234 /* Fetch the list of shared libraries. */
1235 gdb::optional<gdb::char_vector> svr4_library_document
1236 = target_read_stralloc (current_top_target (), TARGET_OBJECT_LIBRARIES_SVR4,
1238 if (!svr4_library_document)
1241 return svr4_parse_libraries (svr4_library_document->data (), list);
1247 svr4_current_sos_via_xfer_libraries (struct svr4_library_list *list,
1255 /* If no shared library information is available from the dynamic
1256 linker, build a fallback list from other sources. */
1258 static struct so_list *
1259 svr4_default_sos (void)
1261 struct svr4_info *info = get_svr4_info ();
1262 struct so_list *newobj;
1264 if (!info->debug_loader_offset_p)
1267 newobj = XCNEW (struct so_list);
1268 lm_info_svr4 *li = new lm_info_svr4;
1269 newobj->lm_info = li;
1271 /* Nothing will ever check the other fields if we set l_addr_p. */
1272 li->l_addr = info->debug_loader_offset;
1275 strncpy (newobj->so_name, info->debug_loader_name, SO_NAME_MAX_PATH_SIZE - 1);
1276 newobj->so_name[SO_NAME_MAX_PATH_SIZE - 1] = '\0';
1277 strcpy (newobj->so_original_name, newobj->so_name);
1282 /* Read the whole inferior libraries chain starting at address LM.
1283 Expect the first entry in the chain's previous entry to be PREV_LM.
1284 Add the entries to the tail referenced by LINK_PTR_PTR. Ignore the
1285 first entry if IGNORE_FIRST and set global MAIN_LM_ADDR according
1286 to it. Returns nonzero upon success. If zero is returned the
1287 entries stored to LINK_PTR_PTR are still valid although they may
1288 represent only part of the inferior library list. */
1291 svr4_read_so_list (CORE_ADDR lm, CORE_ADDR prev_lm,
1292 struct so_list ***link_ptr_ptr, int ignore_first)
1294 CORE_ADDR first_l_name = 0;
1297 for (; lm != 0; prev_lm = lm, lm = next_lm)
1300 gdb::unique_xmalloc_ptr<char> buffer;
1302 so_list_up newobj (XCNEW (struct so_list));
1304 lm_info_svr4 *li = lm_info_read (lm).release ();
1305 newobj->lm_info = li;
1309 next_lm = li->l_next;
1311 if (li->l_prev != prev_lm)
1313 warning (_("Corrupted shared library list: %s != %s"),
1314 paddress (target_gdbarch (), prev_lm),
1315 paddress (target_gdbarch (), li->l_prev));
1319 /* For SVR4 versions, the first entry in the link map is for the
1320 inferior executable, so we must ignore it. For some versions of
1321 SVR4, it has no name. For others (Solaris 2.3 for example), it
1322 does have a name, so we can no longer use a missing name to
1323 decide when to ignore it. */
1324 if (ignore_first && li->l_prev == 0)
1326 struct svr4_info *info = get_svr4_info ();
1328 first_l_name = li->l_name;
1329 info->main_lm_addr = li->lm_addr;
1333 /* Extract this shared object's name. */
1334 target_read_string (li->l_name, &buffer, SO_NAME_MAX_PATH_SIZE - 1,
1338 /* If this entry's l_name address matches that of the
1339 inferior executable, then this is not a normal shared
1340 object, but (most likely) a vDSO. In this case, silently
1341 skip it; otherwise emit a warning. */
1342 if (first_l_name == 0 || li->l_name != first_l_name)
1343 warning (_("Can't read pathname for load map: %s."),
1344 safe_strerror (errcode));
1348 strncpy (newobj->so_name, buffer.get (), SO_NAME_MAX_PATH_SIZE - 1);
1349 newobj->so_name[SO_NAME_MAX_PATH_SIZE - 1] = '\0';
1350 strcpy (newobj->so_original_name, newobj->so_name);
1352 /* If this entry has no name, or its name matches the name
1353 for the main executable, don't include it in the list. */
1354 if (! newobj->so_name[0] || match_main (newobj->so_name))
1358 /* Don't free it now. */
1359 **link_ptr_ptr = newobj.release ();
1360 *link_ptr_ptr = &(**link_ptr_ptr)->next;
1366 /* Read the full list of currently loaded shared objects directly
1367 from the inferior, without referring to any libraries read and
1368 stored by the probes interface. Handle special cases relating
1369 to the first elements of the list. */
1371 static struct so_list *
1372 svr4_current_sos_direct (struct svr4_info *info)
1375 struct so_list *head = NULL;
1376 struct so_list **link_ptr = &head;
1377 struct cleanup *back_to;
1379 struct svr4_library_list library_list;
1381 /* Fall back to manual examination of the target if the packet is not
1382 supported or gdbserver failed to find DT_DEBUG. gdb.server/solib-list.exp
1383 tests a case where gdbserver cannot find the shared libraries list while
1384 GDB itself is able to find it via SYMFILE_OBJFILE.
1386 Unfortunately statically linked inferiors will also fall back through this
1387 suboptimal code path. */
1389 info->using_xfer = svr4_current_sos_via_xfer_libraries (&library_list,
1391 if (info->using_xfer)
1393 if (library_list.main_lm)
1394 info->main_lm_addr = library_list.main_lm;
1396 return library_list.head ? library_list.head : svr4_default_sos ();
1399 /* Always locate the debug struct, in case it has moved. */
1400 info->debug_base = 0;
1403 /* If we can't find the dynamic linker's base structure, this
1404 must not be a dynamically linked executable. Hmm. */
1405 if (! info->debug_base)
1406 return svr4_default_sos ();
1408 /* Assume that everything is a library if the dynamic loader was loaded
1409 late by a static executable. */
1410 if (exec_bfd && bfd_get_section_by_name (exec_bfd, ".dynamic") == NULL)
1415 back_to = make_cleanup (svr4_free_library_list, &head);
1417 /* Walk the inferior's link map list, and build our list of
1418 `struct so_list' nodes. */
1419 lm = solib_svr4_r_map (info);
1421 svr4_read_so_list (lm, 0, &link_ptr, ignore_first);
1423 /* On Solaris, the dynamic linker is not in the normal list of
1424 shared objects, so make sure we pick it up too. Having
1425 symbol information for the dynamic linker is quite crucial
1426 for skipping dynamic linker resolver code. */
1427 lm = solib_svr4_r_ldsomap (info);
1429 svr4_read_so_list (lm, 0, &link_ptr, 0);
1431 discard_cleanups (back_to);
1434 return svr4_default_sos ();
1439 /* Implement the main part of the "current_sos" target_so_ops
1442 static struct so_list *
1443 svr4_current_sos_1 (void)
1445 struct svr4_info *info = get_svr4_info ();
1447 /* If the solib list has been read and stored by the probes
1448 interface then we return a copy of the stored list. */
1449 if (info->solib_list != NULL)
1450 return svr4_copy_library_list (info->solib_list);
1452 /* Otherwise obtain the solib list directly from the inferior. */
1453 return svr4_current_sos_direct (info);
1456 /* Implement the "current_sos" target_so_ops method. */
1458 static struct so_list *
1459 svr4_current_sos (void)
1461 struct so_list *so_head = svr4_current_sos_1 ();
1462 struct mem_range vsyscall_range;
1464 /* Filter out the vDSO module, if present. Its symbol file would
1465 not be found on disk. The vDSO/vsyscall's OBJFILE is instead
1466 managed by symfile-mem.c:add_vsyscall_page. */
1467 if (gdbarch_vsyscall_range (target_gdbarch (), &vsyscall_range)
1468 && vsyscall_range.length != 0)
1470 struct so_list **sop;
1473 while (*sop != NULL)
1475 struct so_list *so = *sop;
1477 /* We can't simply match the vDSO by starting address alone,
1478 because lm_info->l_addr_inferior (and also l_addr) do not
1479 necessarily represent the real starting address of the
1480 ELF if the vDSO's ELF itself is "prelinked". The l_ld
1481 field (the ".dynamic" section of the shared object)
1482 always points at the absolute/resolved address though.
1483 So check whether that address is inside the vDSO's
1486 E.g., on Linux 3.16 (x86_64) the vDSO is a regular
1487 0-based ELF, and we see:
1490 33 AT_SYSINFO_EHDR System-supplied DSO's ELF header 0x7ffff7ffb000
1491 (gdb) p/x *_r_debug.r_map.l_next
1492 $1 = {l_addr = 0x7ffff7ffb000, ..., l_ld = 0x7ffff7ffb318, ...}
1494 And on Linux 2.6.32 (x86_64) we see:
1497 33 AT_SYSINFO_EHDR System-supplied DSO's ELF header 0x7ffff7ffe000
1498 (gdb) p/x *_r_debug.r_map.l_next
1499 $5 = {l_addr = 0x7ffff88fe000, ..., l_ld = 0x7ffff7ffe580, ... }
1501 Dumping that vDSO shows:
1503 (gdb) info proc mappings
1504 0x7ffff7ffe000 0x7ffff7fff000 0x1000 0 [vdso]
1505 (gdb) dump memory vdso.bin 0x7ffff7ffe000 0x7ffff7fff000
1506 # readelf -Wa vdso.bin
1508 Entry point address: 0xffffffffff700700
1511 [Nr] Name Type Address Off Size
1512 [ 0] NULL 0000000000000000 000000 000000
1513 [ 1] .hash HASH ffffffffff700120 000120 000038
1514 [ 2] .dynsym DYNSYM ffffffffff700158 000158 0000d8
1516 [ 9] .dynamic DYNAMIC ffffffffff700580 000580 0000f0
1519 lm_info_svr4 *li = (lm_info_svr4 *) so->lm_info;
1521 if (address_in_mem_range (li->l_ld, &vsyscall_range))
1535 /* Get the address of the link_map for a given OBJFILE. */
1538 svr4_fetch_objfile_link_map (struct objfile *objfile)
1541 struct svr4_info *info = get_svr4_info ();
1543 /* Cause svr4_current_sos() to be run if it hasn't been already. */
1544 if (info->main_lm_addr == 0)
1545 solib_add (NULL, 0, auto_solib_add);
1547 /* svr4_current_sos() will set main_lm_addr for the main executable. */
1548 if (objfile == symfile_objfile)
1549 return info->main_lm_addr;
1551 /* The other link map addresses may be found by examining the list
1552 of shared libraries. */
1553 for (so = master_so_list (); so; so = so->next)
1554 if (so->objfile == objfile)
1556 lm_info_svr4 *li = (lm_info_svr4 *) so->lm_info;
1565 /* On some systems, the only way to recognize the link map entry for
1566 the main executable file is by looking at its name. Return
1567 non-zero iff SONAME matches one of the known main executable names. */
1570 match_main (const char *soname)
1572 const char * const *mainp;
1574 for (mainp = main_name_list; *mainp != NULL; mainp++)
1576 if (strcmp (soname, *mainp) == 0)
1583 /* Return 1 if PC lies in the dynamic symbol resolution code of the
1584 SVR4 run time loader. */
1587 svr4_in_dynsym_resolve_code (CORE_ADDR pc)
1589 struct svr4_info *info = get_svr4_info ();
1591 return ((pc >= info->interp_text_sect_low
1592 && pc < info->interp_text_sect_high)
1593 || (pc >= info->interp_plt_sect_low
1594 && pc < info->interp_plt_sect_high)
1595 || in_plt_section (pc)
1596 || in_gnu_ifunc_stub (pc));
1599 /* Given an executable's ABFD and target, compute the entry-point
1603 exec_entry_point (struct bfd *abfd, struct target_ops *targ)
1607 /* KevinB wrote ... for most targets, the address returned by
1608 bfd_get_start_address() is the entry point for the start
1609 function. But, for some targets, bfd_get_start_address() returns
1610 the address of a function descriptor from which the entry point
1611 address may be extracted. This address is extracted by
1612 gdbarch_convert_from_func_ptr_addr(). The method
1613 gdbarch_convert_from_func_ptr_addr() is the merely the identify
1614 function for targets which don't use function descriptors. */
1615 addr = gdbarch_convert_from_func_ptr_addr (target_gdbarch (),
1616 bfd_get_start_address (abfd),
1618 return gdbarch_addr_bits_remove (target_gdbarch (), addr);
1621 /* A probe and its associated action. */
1623 struct probe_and_action
1628 /* The relocated address of the probe. */
1632 enum probe_action action;
1635 /* Returns a hash code for the probe_and_action referenced by p. */
1638 hash_probe_and_action (const void *p)
1640 const struct probe_and_action *pa = (const struct probe_and_action *) p;
1642 return (hashval_t) pa->address;
1645 /* Returns non-zero if the probe_and_actions referenced by p1 and p2
1649 equal_probe_and_action (const void *p1, const void *p2)
1651 const struct probe_and_action *pa1 = (const struct probe_and_action *) p1;
1652 const struct probe_and_action *pa2 = (const struct probe_and_action *) p2;
1654 return pa1->address == pa2->address;
1657 /* Register a solib event probe and its associated action in the
1661 register_solib_event_probe (probe *prob, CORE_ADDR address,
1662 enum probe_action action)
1664 struct svr4_info *info = get_svr4_info ();
1665 struct probe_and_action lookup, *pa;
1668 /* Create the probes table, if necessary. */
1669 if (info->probes_table == NULL)
1670 info->probes_table = htab_create_alloc (1, hash_probe_and_action,
1671 equal_probe_and_action,
1672 xfree, xcalloc, xfree);
1675 lookup.address = address;
1676 slot = htab_find_slot (info->probes_table, &lookup, INSERT);
1677 gdb_assert (*slot == HTAB_EMPTY_ENTRY);
1679 pa = XCNEW (struct probe_and_action);
1681 pa->address = address;
1682 pa->action = action;
1687 /* Get the solib event probe at the specified location, and the
1688 action associated with it. Returns NULL if no solib event probe
1691 static struct probe_and_action *
1692 solib_event_probe_at (struct svr4_info *info, CORE_ADDR address)
1694 struct probe_and_action lookup;
1697 lookup.address = address;
1698 slot = htab_find_slot (info->probes_table, &lookup, NO_INSERT);
1703 return (struct probe_and_action *) *slot;
1706 /* Decide what action to take when the specified solib event probe is
1709 static enum probe_action
1710 solib_event_probe_action (struct probe_and_action *pa)
1712 enum probe_action action;
1713 unsigned probe_argc = 0;
1714 struct frame_info *frame = get_current_frame ();
1716 action = pa->action;
1717 if (action == DO_NOTHING || action == PROBES_INTERFACE_FAILED)
1720 gdb_assert (action == FULL_RELOAD || action == UPDATE_OR_RELOAD);
1722 /* Check that an appropriate number of arguments has been supplied.
1724 arg0: Lmid_t lmid (mandatory)
1725 arg1: struct r_debug *debug_base (mandatory)
1726 arg2: struct link_map *new (optional, for incremental updates) */
1729 probe_argc = pa->prob->get_argument_count (frame);
1731 CATCH (ex, RETURN_MASK_ERROR)
1733 exception_print (gdb_stderr, ex);
1738 /* If get_argument_count throws an exception, probe_argc will be set
1739 to zero. However, if pa->prob does not have arguments, then
1740 get_argument_count will succeed but probe_argc will also be zero.
1741 Both cases happen because of different things, but they are
1742 treated equally here: action will be set to
1743 PROBES_INTERFACE_FAILED. */
1744 if (probe_argc == 2)
1745 action = FULL_RELOAD;
1746 else if (probe_argc < 2)
1747 action = PROBES_INTERFACE_FAILED;
1752 /* Populate the shared object list by reading the entire list of
1753 shared objects from the inferior. Handle special cases relating
1754 to the first elements of the list. Returns nonzero on success. */
1757 solist_update_full (struct svr4_info *info)
1759 free_solib_list (info);
1760 info->solib_list = svr4_current_sos_direct (info);
1765 /* Update the shared object list starting from the link-map entry
1766 passed by the linker in the probe's third argument. Returns
1767 nonzero if the list was successfully updated, or zero to indicate
1771 solist_update_incremental (struct svr4_info *info, CORE_ADDR lm)
1773 struct so_list *tail;
1776 /* svr4_current_sos_direct contains logic to handle a number of
1777 special cases relating to the first elements of the list. To
1778 avoid duplicating this logic we defer to solist_update_full
1779 if the list is empty. */
1780 if (info->solib_list == NULL)
1783 /* Fall back to a full update if we are using a remote target
1784 that does not support incremental transfers. */
1785 if (info->using_xfer && !target_augmented_libraries_svr4_read ())
1788 /* Walk to the end of the list. */
1789 for (tail = info->solib_list; tail->next != NULL; tail = tail->next)
1792 lm_info_svr4 *li = (lm_info_svr4 *) tail->lm_info;
1793 prev_lm = li->lm_addr;
1795 /* Read the new objects. */
1796 if (info->using_xfer)
1798 struct svr4_library_list library_list;
1801 xsnprintf (annex, sizeof (annex), "start=%s;prev=%s",
1802 phex_nz (lm, sizeof (lm)),
1803 phex_nz (prev_lm, sizeof (prev_lm)));
1804 if (!svr4_current_sos_via_xfer_libraries (&library_list, annex))
1807 tail->next = library_list.head;
1811 struct so_list **link = &tail->next;
1813 /* IGNORE_FIRST may safely be set to zero here because the
1814 above check and deferral to solist_update_full ensures
1815 that this call to svr4_read_so_list will never see the
1817 if (!svr4_read_so_list (lm, prev_lm, &link, 0))
1824 /* Disable the probes-based linker interface and revert to the
1825 original interface. We don't reset the breakpoints as the
1826 ones set up for the probes-based interface are adequate. */
1829 disable_probes_interface ()
1831 struct svr4_info *info = get_svr4_info ();
1833 warning (_("Probes-based dynamic linker interface failed.\n"
1834 "Reverting to original interface.\n"));
1836 free_probes_table (info);
1837 free_solib_list (info);
1840 /* Update the solib list as appropriate when using the
1841 probes-based linker interface. Do nothing if using the
1842 standard interface. */
1845 svr4_handle_solib_event (void)
1847 struct svr4_info *info = get_svr4_info ();
1848 struct probe_and_action *pa;
1849 enum probe_action action;
1850 struct value *val = NULL;
1851 CORE_ADDR pc, debug_base, lm = 0;
1852 struct frame_info *frame = get_current_frame ();
1854 /* Do nothing if not using the probes interface. */
1855 if (info->probes_table == NULL)
1858 /* If anything goes wrong we revert to the original linker
1860 auto cleanup = make_scope_exit (disable_probes_interface);
1862 pc = regcache_read_pc (get_current_regcache ());
1863 pa = solib_event_probe_at (info, pc);
1867 action = solib_event_probe_action (pa);
1868 if (action == PROBES_INTERFACE_FAILED)
1871 if (action == DO_NOTHING)
1877 /* evaluate_argument looks up symbols in the dynamic linker
1878 using find_pc_section. find_pc_section is accelerated by a cache
1879 called the section map. The section map is invalidated every
1880 time a shared library is loaded or unloaded, and if the inferior
1881 is generating a lot of shared library events then the section map
1882 will be updated every time svr4_handle_solib_event is called.
1883 We called find_pc_section in svr4_create_solib_event_breakpoints,
1884 so we can guarantee that the dynamic linker's sections are in the
1885 section map. We can therefore inhibit section map updates across
1886 these calls to evaluate_argument and save a lot of time. */
1888 scoped_restore inhibit_updates
1889 = inhibit_section_map_updates (current_program_space);
1893 val = pa->prob->evaluate_argument (1, frame);
1895 CATCH (ex, RETURN_MASK_ERROR)
1897 exception_print (gdb_stderr, ex);
1905 debug_base = value_as_address (val);
1906 if (debug_base == 0)
1909 /* Always locate the debug struct, in case it moved. */
1910 info->debug_base = 0;
1911 if (locate_base (info) == 0)
1914 /* GDB does not currently support libraries loaded via dlmopen
1915 into namespaces other than the initial one. We must ignore
1916 any namespace other than the initial namespace here until
1917 support for this is added to GDB. */
1918 if (debug_base != info->debug_base)
1919 action = DO_NOTHING;
1921 if (action == UPDATE_OR_RELOAD)
1925 val = pa->prob->evaluate_argument (2, frame);
1927 CATCH (ex, RETURN_MASK_ERROR)
1929 exception_print (gdb_stderr, ex);
1935 lm = value_as_address (val);
1938 action = FULL_RELOAD;
1941 /* Resume section map updates. Closing the scope is
1945 if (action == UPDATE_OR_RELOAD)
1947 if (!solist_update_incremental (info, lm))
1948 action = FULL_RELOAD;
1951 if (action == FULL_RELOAD)
1953 if (!solist_update_full (info))
1960 /* Helper function for svr4_update_solib_event_breakpoints. */
1963 svr4_update_solib_event_breakpoint (struct breakpoint *b, void *arg)
1965 struct bp_location *loc;
1967 if (b->type != bp_shlib_event)
1969 /* Continue iterating. */
1973 for (loc = b->loc; loc != NULL; loc = loc->next)
1975 struct svr4_info *info;
1976 struct probe_and_action *pa;
1978 info = ((struct svr4_info *)
1979 program_space_data (loc->pspace, solib_svr4_pspace_data));
1980 if (info == NULL || info->probes_table == NULL)
1983 pa = solib_event_probe_at (info, loc->address);
1987 if (pa->action == DO_NOTHING)
1989 if (b->enable_state == bp_disabled && stop_on_solib_events)
1990 enable_breakpoint (b);
1991 else if (b->enable_state == bp_enabled && !stop_on_solib_events)
1992 disable_breakpoint (b);
1998 /* Continue iterating. */
2002 /* Enable or disable optional solib event breakpoints as appropriate.
2003 Called whenever stop_on_solib_events is changed. */
2006 svr4_update_solib_event_breakpoints (void)
2008 iterate_over_breakpoints (svr4_update_solib_event_breakpoint, NULL);
2011 /* Create and register solib event breakpoints. PROBES is an array
2012 of NUM_PROBES elements, each of which is vector of probes. A
2013 solib event breakpoint will be created and registered for each
2017 svr4_create_probe_breakpoints (struct gdbarch *gdbarch,
2018 const std::vector<probe *> *probes,
2019 struct objfile *objfile)
2021 for (int i = 0; i < NUM_PROBES; i++)
2023 enum probe_action action = probe_info[i].action;
2025 for (probe *p : probes[i])
2027 CORE_ADDR address = p->get_relocated_address (objfile);
2029 create_solib_event_breakpoint (gdbarch, address);
2030 register_solib_event_probe (p, address, action);
2034 svr4_update_solib_event_breakpoints ();
2037 /* Both the SunOS and the SVR4 dynamic linkers call a marker function
2038 before and after mapping and unmapping shared libraries. The sole
2039 purpose of this method is to allow debuggers to set a breakpoint so
2040 they can track these changes.
2042 Some versions of the glibc dynamic linker contain named probes
2043 to allow more fine grained stopping. Given the address of the
2044 original marker function, this function attempts to find these
2045 probes, and if found, sets breakpoints on those instead. If the
2046 probes aren't found, a single breakpoint is set on the original
2050 svr4_create_solib_event_breakpoints (struct gdbarch *gdbarch,
2053 struct obj_section *os;
2055 os = find_pc_section (address);
2060 for (with_prefix = 0; with_prefix <= 1; with_prefix++)
2062 std::vector<probe *> probes[NUM_PROBES];
2063 int all_probes_found = 1;
2064 int checked_can_use_probe_arguments = 0;
2066 for (int i = 0; i < NUM_PROBES; i++)
2068 const char *name = probe_info[i].name;
2072 /* Fedora 17 and Red Hat Enterprise Linux 6.2-6.4
2073 shipped with an early version of the probes code in
2074 which the probes' names were prefixed with "rtld_"
2075 and the "map_failed" probe did not exist. The
2076 locations of the probes are otherwise the same, so
2077 we check for probes with prefixed names if probes
2078 with unprefixed names are not present. */
2081 xsnprintf (buf, sizeof (buf), "rtld_%s", name);
2085 probes[i] = find_probes_in_objfile (os->objfile, "rtld", name);
2087 /* The "map_failed" probe did not exist in early
2088 versions of the probes code in which the probes'
2089 names were prefixed with "rtld_". */
2090 if (strcmp (name, "rtld_map_failed") == 0)
2093 if (probes[i].empty ())
2095 all_probes_found = 0;
2099 /* Ensure probe arguments can be evaluated. */
2100 if (!checked_can_use_probe_arguments)
2103 if (!p->can_evaluate_arguments ())
2105 all_probes_found = 0;
2108 checked_can_use_probe_arguments = 1;
2112 if (all_probes_found)
2113 svr4_create_probe_breakpoints (gdbarch, probes, os->objfile);
2115 if (all_probes_found)
2120 create_solib_event_breakpoint (gdbarch, address);
2123 /* Helper function for gdb_bfd_lookup_symbol. */
2126 cmp_name_and_sec_flags (const asymbol *sym, const void *data)
2128 return (strcmp (sym->name, (const char *) data) == 0
2129 && (sym->section->flags & (SEC_CODE | SEC_DATA)) != 0);
2131 /* Arrange for dynamic linker to hit breakpoint.
2133 Both the SunOS and the SVR4 dynamic linkers have, as part of their
2134 debugger interface, support for arranging for the inferior to hit
2135 a breakpoint after mapping in the shared libraries. This function
2136 enables that breakpoint.
2138 For SunOS, there is a special flag location (in_debugger) which we
2139 set to 1. When the dynamic linker sees this flag set, it will set
2140 a breakpoint at a location known only to itself, after saving the
2141 original contents of that place and the breakpoint address itself,
2142 in it's own internal structures. When we resume the inferior, it
2143 will eventually take a SIGTRAP when it runs into the breakpoint.
2144 We handle this (in a different place) by restoring the contents of
2145 the breakpointed location (which is only known after it stops),
2146 chasing around to locate the shared libraries that have been
2147 loaded, then resuming.
2149 For SVR4, the debugger interface structure contains a member (r_brk)
2150 which is statically initialized at the time the shared library is
2151 built, to the offset of a function (_r_debug_state) which is guaran-
2152 teed to be called once before mapping in a library, and again when
2153 the mapping is complete. At the time we are examining this member,
2154 it contains only the unrelocated offset of the function, so we have
2155 to do our own relocation. Later, when the dynamic linker actually
2156 runs, it relocates r_brk to be the actual address of _r_debug_state().
2158 The debugger interface structure also contains an enumeration which
2159 is set to either RT_ADD or RT_DELETE prior to changing the mapping,
2160 depending upon whether or not the library is being mapped or unmapped,
2161 and then set to RT_CONSISTENT after the library is mapped/unmapped. */
2164 enable_break (struct svr4_info *info, int from_tty)
2166 struct bound_minimal_symbol msymbol;
2167 const char * const *bkpt_namep;
2168 asection *interp_sect;
2171 info->interp_text_sect_low = info->interp_text_sect_high = 0;
2172 info->interp_plt_sect_low = info->interp_plt_sect_high = 0;
2174 /* If we already have a shared library list in the target, and
2175 r_debug contains r_brk, set the breakpoint there - this should
2176 mean r_brk has already been relocated. Assume the dynamic linker
2177 is the object containing r_brk. */
2179 solib_add (NULL, from_tty, auto_solib_add);
2181 if (info->debug_base && solib_svr4_r_map (info) != 0)
2182 sym_addr = solib_svr4_r_brk (info);
2186 struct obj_section *os;
2188 sym_addr = gdbarch_addr_bits_remove
2190 gdbarch_convert_from_func_ptr_addr (target_gdbarch (),
2192 current_top_target ()));
2194 /* On at least some versions of Solaris there's a dynamic relocation
2195 on _r_debug.r_brk and SYM_ADDR may not be relocated yet, e.g., if
2196 we get control before the dynamic linker has self-relocated.
2197 Check if SYM_ADDR is in a known section, if it is assume we can
2198 trust its value. This is just a heuristic though, it could go away
2199 or be replaced if it's getting in the way.
2201 On ARM we need to know whether the ISA of rtld_db_dlactivity (or
2202 however it's spelled in your particular system) is ARM or Thumb.
2203 That knowledge is encoded in the address, if it's Thumb the low bit
2204 is 1. However, we've stripped that info above and it's not clear
2205 what all the consequences are of passing a non-addr_bits_remove'd
2206 address to svr4_create_solib_event_breakpoints. The call to
2207 find_pc_section verifies we know about the address and have some
2208 hope of computing the right kind of breakpoint to use (via
2209 symbol info). It does mean that GDB needs to be pointed at a
2210 non-stripped version of the dynamic linker in order to obtain
2211 information it already knows about. Sigh. */
2213 os = find_pc_section (sym_addr);
2216 /* Record the relocated start and end address of the dynamic linker
2217 text and plt section for svr4_in_dynsym_resolve_code. */
2219 CORE_ADDR load_addr;
2221 tmp_bfd = os->objfile->obfd;
2222 load_addr = ANOFFSET (os->objfile->section_offsets,
2223 SECT_OFF_TEXT (os->objfile));
2225 interp_sect = bfd_get_section_by_name (tmp_bfd, ".text");
2228 info->interp_text_sect_low =
2229 bfd_section_vma (tmp_bfd, interp_sect) + load_addr;
2230 info->interp_text_sect_high =
2231 info->interp_text_sect_low
2232 + bfd_section_size (tmp_bfd, interp_sect);
2234 interp_sect = bfd_get_section_by_name (tmp_bfd, ".plt");
2237 info->interp_plt_sect_low =
2238 bfd_section_vma (tmp_bfd, interp_sect) + load_addr;
2239 info->interp_plt_sect_high =
2240 info->interp_plt_sect_low
2241 + bfd_section_size (tmp_bfd, interp_sect);
2244 svr4_create_solib_event_breakpoints (target_gdbarch (), sym_addr);
2249 /* Find the program interpreter; if not found, warn the user and drop
2250 into the old breakpoint at symbol code. */
2251 gdb::optional<gdb::byte_vector> interp_name_holder
2252 = find_program_interpreter ();
2253 if (interp_name_holder)
2255 const char *interp_name = (const char *) interp_name_holder->data ();
2256 CORE_ADDR load_addr = 0;
2257 int load_addr_found = 0;
2258 int loader_found_in_list = 0;
2260 struct target_ops *tmp_bfd_target;
2264 /* Now we need to figure out where the dynamic linker was
2265 loaded so that we can load its symbols and place a breakpoint
2266 in the dynamic linker itself.
2268 This address is stored on the stack. However, I've been unable
2269 to find any magic formula to find it for Solaris (appears to
2270 be trivial on GNU/Linux). Therefore, we have to try an alternate
2271 mechanism to find the dynamic linker's base address. */
2273 gdb_bfd_ref_ptr tmp_bfd;
2276 tmp_bfd = solib_bfd_open (interp_name);
2278 CATCH (ex, RETURN_MASK_ALL)
2283 if (tmp_bfd == NULL)
2284 goto bkpt_at_symbol;
2286 /* Now convert the TMP_BFD into a target. That way target, as
2287 well as BFD operations can be used. target_bfd_reopen
2288 acquires its own reference. */
2289 tmp_bfd_target = target_bfd_reopen (tmp_bfd.get ());
2291 /* On a running target, we can get the dynamic linker's base
2292 address from the shared library table. */
2293 so = master_so_list ();
2296 if (svr4_same_1 (interp_name, so->so_original_name))
2298 load_addr_found = 1;
2299 loader_found_in_list = 1;
2300 load_addr = lm_addr_check (so, tmp_bfd.get ());
2306 /* If we were not able to find the base address of the loader
2307 from our so_list, then try using the AT_BASE auxilliary entry. */
2308 if (!load_addr_found)
2309 if (target_auxv_search (current_top_target (), AT_BASE, &load_addr) > 0)
2311 int addr_bit = gdbarch_addr_bit (target_gdbarch ());
2313 /* Ensure LOAD_ADDR has proper sign in its possible upper bits so
2314 that `+ load_addr' will overflow CORE_ADDR width not creating
2315 invalid addresses like 0x101234567 for 32bit inferiors on 64bit
2318 if (addr_bit < (sizeof (CORE_ADDR) * HOST_CHAR_BIT))
2320 CORE_ADDR space_size = (CORE_ADDR) 1 << addr_bit;
2321 CORE_ADDR tmp_entry_point = exec_entry_point (tmp_bfd.get (),
2324 gdb_assert (load_addr < space_size);
2326 /* TMP_ENTRY_POINT exceeding SPACE_SIZE would be for prelinked
2327 64bit ld.so with 32bit executable, it should not happen. */
2329 if (tmp_entry_point < space_size
2330 && tmp_entry_point + load_addr >= space_size)
2331 load_addr -= space_size;
2334 load_addr_found = 1;
2337 /* Otherwise we find the dynamic linker's base address by examining
2338 the current pc (which should point at the entry point for the
2339 dynamic linker) and subtracting the offset of the entry point.
2341 This is more fragile than the previous approaches, but is a good
2342 fallback method because it has actually been working well in
2344 if (!load_addr_found)
2346 struct regcache *regcache
2347 = get_thread_arch_regcache (inferior_ptid, target_gdbarch ());
2349 load_addr = (regcache_read_pc (regcache)
2350 - exec_entry_point (tmp_bfd.get (), tmp_bfd_target));
2353 if (!loader_found_in_list)
2355 info->debug_loader_name = xstrdup (interp_name);
2356 info->debug_loader_offset_p = 1;
2357 info->debug_loader_offset = load_addr;
2358 solib_add (NULL, from_tty, auto_solib_add);
2361 /* Record the relocated start and end address of the dynamic linker
2362 text and plt section for svr4_in_dynsym_resolve_code. */
2363 interp_sect = bfd_get_section_by_name (tmp_bfd.get (), ".text");
2366 info->interp_text_sect_low =
2367 bfd_section_vma (tmp_bfd.get (), interp_sect) + load_addr;
2368 info->interp_text_sect_high =
2369 info->interp_text_sect_low
2370 + bfd_section_size (tmp_bfd.get (), interp_sect);
2372 interp_sect = bfd_get_section_by_name (tmp_bfd.get (), ".plt");
2375 info->interp_plt_sect_low =
2376 bfd_section_vma (tmp_bfd.get (), interp_sect) + load_addr;
2377 info->interp_plt_sect_high =
2378 info->interp_plt_sect_low
2379 + bfd_section_size (tmp_bfd.get (), interp_sect);
2382 /* Now try to set a breakpoint in the dynamic linker. */
2383 for (bkpt_namep = solib_break_names; *bkpt_namep != NULL; bkpt_namep++)
2385 sym_addr = gdb_bfd_lookup_symbol (tmp_bfd.get (),
2386 cmp_name_and_sec_flags,
2393 /* Convert 'sym_addr' from a function pointer to an address.
2394 Because we pass tmp_bfd_target instead of the current
2395 target, this will always produce an unrelocated value. */
2396 sym_addr = gdbarch_convert_from_func_ptr_addr (target_gdbarch (),
2400 /* We're done with both the temporary bfd and target. Closing
2401 the target closes the underlying bfd, because it holds the
2402 only remaining reference. */
2403 target_close (tmp_bfd_target);
2407 svr4_create_solib_event_breakpoints (target_gdbarch (),
2408 load_addr + sym_addr);
2412 /* For whatever reason we couldn't set a breakpoint in the dynamic
2413 linker. Warn and drop into the old code. */
2415 warning (_("Unable to find dynamic linker breakpoint function.\n"
2416 "GDB will be unable to debug shared library initializers\n"
2417 "and track explicitly loaded dynamic code."));
2420 /* Scan through the lists of symbols, trying to look up the symbol and
2421 set a breakpoint there. Terminate loop when we/if we succeed. */
2423 for (bkpt_namep = solib_break_names; *bkpt_namep != NULL; bkpt_namep++)
2425 msymbol = lookup_minimal_symbol (*bkpt_namep, NULL, symfile_objfile);
2426 if ((msymbol.minsym != NULL)
2427 && (BMSYMBOL_VALUE_ADDRESS (msymbol) != 0))
2429 sym_addr = BMSYMBOL_VALUE_ADDRESS (msymbol);
2430 sym_addr = gdbarch_convert_from_func_ptr_addr (target_gdbarch (),
2432 current_top_target ());
2433 svr4_create_solib_event_breakpoints (target_gdbarch (), sym_addr);
2438 if (interp_name_holder && !current_inferior ()->attach_flag)
2440 for (bkpt_namep = bkpt_names; *bkpt_namep != NULL; bkpt_namep++)
2442 msymbol = lookup_minimal_symbol (*bkpt_namep, NULL, symfile_objfile);
2443 if ((msymbol.minsym != NULL)
2444 && (BMSYMBOL_VALUE_ADDRESS (msymbol) != 0))
2446 sym_addr = BMSYMBOL_VALUE_ADDRESS (msymbol);
2447 sym_addr = gdbarch_convert_from_func_ptr_addr (target_gdbarch (),
2449 current_top_target ());
2450 svr4_create_solib_event_breakpoints (target_gdbarch (), sym_addr);
2458 /* Read the ELF program headers from ABFD. */
2460 static gdb::optional<gdb::byte_vector>
2461 read_program_headers_from_bfd (bfd *abfd)
2463 Elf_Internal_Ehdr *ehdr = elf_elfheader (abfd);
2464 int phdrs_size = ehdr->e_phnum * ehdr->e_phentsize;
2465 if (phdrs_size == 0)
2468 gdb::byte_vector buf (phdrs_size);
2469 if (bfd_seek (abfd, ehdr->e_phoff, SEEK_SET) != 0
2470 || bfd_bread (buf.data (), phdrs_size, abfd) != phdrs_size)
2476 /* Return 1 and fill *DISPLACEMENTP with detected PIE offset of inferior
2477 exec_bfd. Otherwise return 0.
2479 We relocate all of the sections by the same amount. This
2480 behavior is mandated by recent editions of the System V ABI.
2481 According to the System V Application Binary Interface,
2482 Edition 4.1, page 5-5:
2484 ... Though the system chooses virtual addresses for
2485 individual processes, it maintains the segments' relative
2486 positions. Because position-independent code uses relative
2487 addressesing between segments, the difference between
2488 virtual addresses in memory must match the difference
2489 between virtual addresses in the file. The difference
2490 between the virtual address of any segment in memory and
2491 the corresponding virtual address in the file is thus a
2492 single constant value for any one executable or shared
2493 object in a given process. This difference is the base
2494 address. One use of the base address is to relocate the
2495 memory image of the program during dynamic linking.
2497 The same language also appears in Edition 4.0 of the System V
2498 ABI and is left unspecified in some of the earlier editions.
2500 Decide if the objfile needs to be relocated. As indicated above, we will
2501 only be here when execution is stopped. But during attachment PC can be at
2502 arbitrary address therefore regcache_read_pc can be misleading (contrary to
2503 the auxv AT_ENTRY value). Moreover for executable with interpreter section
2504 regcache_read_pc would point to the interpreter and not the main executable.
2506 So, to summarize, relocations are necessary when the start address obtained
2507 from the executable is different from the address in auxv AT_ENTRY entry.
2509 [ The astute reader will note that we also test to make sure that
2510 the executable in question has the DYNAMIC flag set. It is my
2511 opinion that this test is unnecessary (undesirable even). It
2512 was added to avoid inadvertent relocation of an executable
2513 whose e_type member in the ELF header is not ET_DYN. There may
2514 be a time in the future when it is desirable to do relocations
2515 on other types of files as well in which case this condition
2516 should either be removed or modified to accomodate the new file
2517 type. - Kevin, Nov 2000. ] */
2520 svr4_exec_displacement (CORE_ADDR *displacementp)
2522 /* ENTRY_POINT is a possible function descriptor - before
2523 a call to gdbarch_convert_from_func_ptr_addr. */
2524 CORE_ADDR entry_point, exec_displacement;
2526 if (exec_bfd == NULL)
2529 /* Therefore for ELF it is ET_EXEC and not ET_DYN. Both shared libraries
2530 being executed themselves and PIE (Position Independent Executable)
2531 executables are ET_DYN. */
2533 if ((bfd_get_file_flags (exec_bfd) & DYNAMIC) == 0)
2536 if (target_auxv_search (current_top_target (), AT_ENTRY, &entry_point) <= 0)
2539 exec_displacement = entry_point - bfd_get_start_address (exec_bfd);
2541 /* Verify the EXEC_DISPLACEMENT candidate complies with the required page
2542 alignment. It is cheaper than the program headers comparison below. */
2544 if (bfd_get_flavour (exec_bfd) == bfd_target_elf_flavour)
2546 const struct elf_backend_data *elf = get_elf_backend_data (exec_bfd);
2548 /* p_align of PT_LOAD segments does not specify any alignment but
2549 only congruency of addresses:
2550 p_offset % p_align == p_vaddr % p_align
2551 Kernel is free to load the executable with lower alignment. */
2553 if ((exec_displacement & (elf->minpagesize - 1)) != 0)
2557 /* Verify that the auxilliary vector describes the same file as exec_bfd, by
2558 comparing their program headers. If the program headers in the auxilliary
2559 vector do not match the program headers in the executable, then we are
2560 looking at a different file than the one used by the kernel - for
2561 instance, "gdb program" connected to "gdbserver :PORT ld.so program". */
2563 if (bfd_get_flavour (exec_bfd) == bfd_target_elf_flavour)
2565 /* Be optimistic and return 0 only if GDB was able to verify the headers
2566 really do not match. */
2569 gdb::optional<gdb::byte_vector> phdrs_target
2570 = read_program_header (-1, &arch_size, NULL);
2571 gdb::optional<gdb::byte_vector> phdrs_binary
2572 = read_program_headers_from_bfd (exec_bfd);
2573 if (phdrs_target && phdrs_binary)
2575 enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ());
2577 /* We are dealing with three different addresses. EXEC_BFD
2578 represents current address in on-disk file. target memory content
2579 may be different from EXEC_BFD as the file may have been prelinked
2580 to a different address after the executable has been loaded.
2581 Moreover the address of placement in target memory can be
2582 different from what the program headers in target memory say -
2583 this is the goal of PIE.
2585 Detected DISPLACEMENT covers both the offsets of PIE placement and
2586 possible new prelink performed after start of the program. Here
2587 relocate BUF and BUF2 just by the EXEC_BFD vs. target memory
2588 content offset for the verification purpose. */
2590 if (phdrs_target->size () != phdrs_binary->size ()
2591 || bfd_get_arch_size (exec_bfd) != arch_size)
2593 else if (arch_size == 32
2594 && phdrs_target->size () >= sizeof (Elf32_External_Phdr)
2595 && phdrs_target->size () % sizeof (Elf32_External_Phdr) == 0)
2597 Elf_Internal_Ehdr *ehdr2 = elf_tdata (exec_bfd)->elf_header;
2598 Elf_Internal_Phdr *phdr2 = elf_tdata (exec_bfd)->phdr;
2599 CORE_ADDR displacement = 0;
2602 /* DISPLACEMENT could be found more easily by the difference of
2603 ehdr2->e_entry. But we haven't read the ehdr yet, and we
2604 already have enough information to compute that displacement
2605 with what we've read. */
2607 for (i = 0; i < ehdr2->e_phnum; i++)
2608 if (phdr2[i].p_type == PT_LOAD)
2610 Elf32_External_Phdr *phdrp;
2611 gdb_byte *buf_vaddr_p, *buf_paddr_p;
2612 CORE_ADDR vaddr, paddr;
2613 CORE_ADDR displacement_vaddr = 0;
2614 CORE_ADDR displacement_paddr = 0;
2616 phdrp = &((Elf32_External_Phdr *) phdrs_target->data ())[i];
2617 buf_vaddr_p = (gdb_byte *) &phdrp->p_vaddr;
2618 buf_paddr_p = (gdb_byte *) &phdrp->p_paddr;
2620 vaddr = extract_unsigned_integer (buf_vaddr_p, 4,
2622 displacement_vaddr = vaddr - phdr2[i].p_vaddr;
2624 paddr = extract_unsigned_integer (buf_paddr_p, 4,
2626 displacement_paddr = paddr - phdr2[i].p_paddr;
2628 if (displacement_vaddr == displacement_paddr)
2629 displacement = displacement_vaddr;
2634 /* Now compare program headers from the target and the binary
2635 with optional DISPLACEMENT. */
2638 i < phdrs_target->size () / sizeof (Elf32_External_Phdr);
2641 Elf32_External_Phdr *phdrp;
2642 Elf32_External_Phdr *phdr2p;
2643 gdb_byte *buf_vaddr_p, *buf_paddr_p;
2644 CORE_ADDR vaddr, paddr;
2645 asection *plt2_asect;
2647 phdrp = &((Elf32_External_Phdr *) phdrs_target->data ())[i];
2648 buf_vaddr_p = (gdb_byte *) &phdrp->p_vaddr;
2649 buf_paddr_p = (gdb_byte *) &phdrp->p_paddr;
2650 phdr2p = &((Elf32_External_Phdr *) phdrs_binary->data ())[i];
2652 /* PT_GNU_STACK is an exception by being never relocated by
2653 prelink as its addresses are always zero. */
2655 if (memcmp (phdrp, phdr2p, sizeof (*phdrp)) == 0)
2658 /* Check also other adjustment combinations - PR 11786. */
2660 vaddr = extract_unsigned_integer (buf_vaddr_p, 4,
2662 vaddr -= displacement;
2663 store_unsigned_integer (buf_vaddr_p, 4, byte_order, vaddr);
2665 paddr = extract_unsigned_integer (buf_paddr_p, 4,
2667 paddr -= displacement;
2668 store_unsigned_integer (buf_paddr_p, 4, byte_order, paddr);
2670 if (memcmp (phdrp, phdr2p, sizeof (*phdrp)) == 0)
2673 /* Strip modifies the flags and alignment of PT_GNU_RELRO.
2674 CentOS-5 has problems with filesz, memsz as well.
2675 Strip also modifies memsz of PT_TLS.
2677 if (phdr2[i].p_type == PT_GNU_RELRO
2678 || phdr2[i].p_type == PT_TLS)
2680 Elf32_External_Phdr tmp_phdr = *phdrp;
2681 Elf32_External_Phdr tmp_phdr2 = *phdr2p;
2683 memset (tmp_phdr.p_filesz, 0, 4);
2684 memset (tmp_phdr.p_memsz, 0, 4);
2685 memset (tmp_phdr.p_flags, 0, 4);
2686 memset (tmp_phdr.p_align, 0, 4);
2687 memset (tmp_phdr2.p_filesz, 0, 4);
2688 memset (tmp_phdr2.p_memsz, 0, 4);
2689 memset (tmp_phdr2.p_flags, 0, 4);
2690 memset (tmp_phdr2.p_align, 0, 4);
2692 if (memcmp (&tmp_phdr, &tmp_phdr2, sizeof (tmp_phdr))
2697 /* prelink can convert .plt SHT_NOBITS to SHT_PROGBITS. */
2698 plt2_asect = bfd_get_section_by_name (exec_bfd, ".plt");
2702 gdb_byte *buf_filesz_p = (gdb_byte *) &phdrp->p_filesz;
2705 content2 = (bfd_get_section_flags (exec_bfd, plt2_asect)
2706 & SEC_HAS_CONTENTS) != 0;
2708 filesz = extract_unsigned_integer (buf_filesz_p, 4,
2711 /* PLT2_ASECT is from on-disk file (exec_bfd) while
2712 FILESZ is from the in-memory image. */
2714 filesz += bfd_get_section_size (plt2_asect);
2716 filesz -= bfd_get_section_size (plt2_asect);
2718 store_unsigned_integer (buf_filesz_p, 4, byte_order,
2721 if (memcmp (phdrp, phdr2p, sizeof (*phdrp)) == 0)
2728 else if (arch_size == 64
2729 && phdrs_target->size () >= sizeof (Elf64_External_Phdr)
2730 && phdrs_target->size () % sizeof (Elf64_External_Phdr) == 0)
2732 Elf_Internal_Ehdr *ehdr2 = elf_tdata (exec_bfd)->elf_header;
2733 Elf_Internal_Phdr *phdr2 = elf_tdata (exec_bfd)->phdr;
2734 CORE_ADDR displacement = 0;
2737 /* DISPLACEMENT could be found more easily by the difference of
2738 ehdr2->e_entry. But we haven't read the ehdr yet, and we
2739 already have enough information to compute that displacement
2740 with what we've read. */
2742 for (i = 0; i < ehdr2->e_phnum; i++)
2743 if (phdr2[i].p_type == PT_LOAD)
2745 Elf64_External_Phdr *phdrp;
2746 gdb_byte *buf_vaddr_p, *buf_paddr_p;
2747 CORE_ADDR vaddr, paddr;
2748 CORE_ADDR displacement_vaddr = 0;
2749 CORE_ADDR displacement_paddr = 0;
2751 phdrp = &((Elf64_External_Phdr *) phdrs_target->data ())[i];
2752 buf_vaddr_p = (gdb_byte *) &phdrp->p_vaddr;
2753 buf_paddr_p = (gdb_byte *) &phdrp->p_paddr;
2755 vaddr = extract_unsigned_integer (buf_vaddr_p, 8,
2757 displacement_vaddr = vaddr - phdr2[i].p_vaddr;
2759 paddr = extract_unsigned_integer (buf_paddr_p, 8,
2761 displacement_paddr = paddr - phdr2[i].p_paddr;
2763 if (displacement_vaddr == displacement_paddr)
2764 displacement = displacement_vaddr;
2769 /* Now compare BUF and BUF2 with optional DISPLACEMENT. */
2772 i < phdrs_target->size () / sizeof (Elf64_External_Phdr);
2775 Elf64_External_Phdr *phdrp;
2776 Elf64_External_Phdr *phdr2p;
2777 gdb_byte *buf_vaddr_p, *buf_paddr_p;
2778 CORE_ADDR vaddr, paddr;
2779 asection *plt2_asect;
2781 phdrp = &((Elf64_External_Phdr *) phdrs_target->data ())[i];
2782 buf_vaddr_p = (gdb_byte *) &phdrp->p_vaddr;
2783 buf_paddr_p = (gdb_byte *) &phdrp->p_paddr;
2784 phdr2p = &((Elf64_External_Phdr *) phdrs_binary->data ())[i];
2786 /* PT_GNU_STACK is an exception by being never relocated by
2787 prelink as its addresses are always zero. */
2789 if (memcmp (phdrp, phdr2p, sizeof (*phdrp)) == 0)
2792 /* Check also other adjustment combinations - PR 11786. */
2794 vaddr = extract_unsigned_integer (buf_vaddr_p, 8,
2796 vaddr -= displacement;
2797 store_unsigned_integer (buf_vaddr_p, 8, byte_order, vaddr);
2799 paddr = extract_unsigned_integer (buf_paddr_p, 8,
2801 paddr -= displacement;
2802 store_unsigned_integer (buf_paddr_p, 8, byte_order, paddr);
2804 if (memcmp (phdrp, phdr2p, sizeof (*phdrp)) == 0)
2807 /* Strip modifies the flags and alignment of PT_GNU_RELRO.
2808 CentOS-5 has problems with filesz, memsz as well.
2809 Strip also modifies memsz of PT_TLS.
2811 if (phdr2[i].p_type == PT_GNU_RELRO
2812 || phdr2[i].p_type == PT_TLS)
2814 Elf64_External_Phdr tmp_phdr = *phdrp;
2815 Elf64_External_Phdr tmp_phdr2 = *phdr2p;
2817 memset (tmp_phdr.p_filesz, 0, 8);
2818 memset (tmp_phdr.p_memsz, 0, 8);
2819 memset (tmp_phdr.p_flags, 0, 4);
2820 memset (tmp_phdr.p_align, 0, 8);
2821 memset (tmp_phdr2.p_filesz, 0, 8);
2822 memset (tmp_phdr2.p_memsz, 0, 8);
2823 memset (tmp_phdr2.p_flags, 0, 4);
2824 memset (tmp_phdr2.p_align, 0, 8);
2826 if (memcmp (&tmp_phdr, &tmp_phdr2, sizeof (tmp_phdr))
2831 /* prelink can convert .plt SHT_NOBITS to SHT_PROGBITS. */
2832 plt2_asect = bfd_get_section_by_name (exec_bfd, ".plt");
2836 gdb_byte *buf_filesz_p = (gdb_byte *) &phdrp->p_filesz;
2839 content2 = (bfd_get_section_flags (exec_bfd, plt2_asect)
2840 & SEC_HAS_CONTENTS) != 0;
2842 filesz = extract_unsigned_integer (buf_filesz_p, 8,
2845 /* PLT2_ASECT is from on-disk file (exec_bfd) while
2846 FILESZ is from the in-memory image. */
2848 filesz += bfd_get_section_size (plt2_asect);
2850 filesz -= bfd_get_section_size (plt2_asect);
2852 store_unsigned_integer (buf_filesz_p, 8, byte_order,
2855 if (memcmp (phdrp, phdr2p, sizeof (*phdrp)) == 0)
2869 /* It can be printed repeatedly as there is no easy way to check
2870 the executable symbols/file has been already relocated to
2873 printf_unfiltered (_("Using PIE (Position Independent Executable) "
2874 "displacement %s for \"%s\".\n"),
2875 paddress (target_gdbarch (), exec_displacement),
2876 bfd_get_filename (exec_bfd));
2879 *displacementp = exec_displacement;
2883 /* Relocate the main executable. This function should be called upon
2884 stopping the inferior process at the entry point to the program.
2885 The entry point from BFD is compared to the AT_ENTRY of AUXV and if they are
2886 different, the main executable is relocated by the proper amount. */
2889 svr4_relocate_main_executable (void)
2891 CORE_ADDR displacement;
2893 /* If we are re-running this executable, SYMFILE_OBJFILE->SECTION_OFFSETS
2894 probably contains the offsets computed using the PIE displacement
2895 from the previous run, which of course are irrelevant for this run.
2896 So we need to determine the new PIE displacement and recompute the
2897 section offsets accordingly, even if SYMFILE_OBJFILE->SECTION_OFFSETS
2898 already contains pre-computed offsets.
2900 If we cannot compute the PIE displacement, either:
2902 - The executable is not PIE.
2904 - SYMFILE_OBJFILE does not match the executable started in the target.
2905 This can happen for main executable symbols loaded at the host while
2906 `ld.so --ld-args main-executable' is loaded in the target.
2908 Then we leave the section offsets untouched and use them as is for
2911 - These section offsets were properly reset earlier, and thus
2912 already contain the correct values. This can happen for instance
2913 when reconnecting via the remote protocol to a target that supports
2914 the `qOffsets' packet.
2916 - The section offsets were not reset earlier, and the best we can
2917 hope is that the old offsets are still applicable to the new run. */
2919 if (! svr4_exec_displacement (&displacement))
2922 /* Even DISPLACEMENT 0 is a valid new difference of in-memory vs. in-file
2925 if (symfile_objfile)
2927 struct section_offsets *new_offsets;
2930 new_offsets = XALLOCAVEC (struct section_offsets,
2931 symfile_objfile->num_sections);
2933 for (i = 0; i < symfile_objfile->num_sections; i++)
2934 new_offsets->offsets[i] = displacement;
2936 objfile_relocate (symfile_objfile, new_offsets);
2942 for (asect = exec_bfd->sections; asect != NULL; asect = asect->next)
2943 exec_set_section_address (bfd_get_filename (exec_bfd), asect->index,
2944 (bfd_section_vma (exec_bfd, asect)
2949 /* Implement the "create_inferior_hook" target_solib_ops method.
2951 For SVR4 executables, this first instruction is either the first
2952 instruction in the dynamic linker (for dynamically linked
2953 executables) or the instruction at "start" for statically linked
2954 executables. For dynamically linked executables, the system
2955 first exec's /lib/libc.so.N, which contains the dynamic linker,
2956 and starts it running. The dynamic linker maps in any needed
2957 shared libraries, maps in the actual user executable, and then
2958 jumps to "start" in the user executable.
2960 We can arrange to cooperate with the dynamic linker to discover the
2961 names of shared libraries that are dynamically linked, and the base
2962 addresses to which they are linked.
2964 This function is responsible for discovering those names and
2965 addresses, and saving sufficient information about them to allow
2966 their symbols to be read at a later time. */
2969 svr4_solib_create_inferior_hook (int from_tty)
2971 struct svr4_info *info;
2973 info = get_svr4_info ();
2975 /* Clear the probes-based interface's state. */
2976 free_probes_table (info);
2977 free_solib_list (info);
2979 /* Relocate the main executable if necessary. */
2980 svr4_relocate_main_executable ();
2982 /* No point setting a breakpoint in the dynamic linker if we can't
2983 hit it (e.g., a core file, or a trace file). */
2984 if (!target_has_execution)
2987 if (!svr4_have_link_map_offsets ())
2990 if (!enable_break (info, from_tty))
2995 svr4_clear_solib (void)
2997 struct svr4_info *info;
2999 info = get_svr4_info ();
3000 info->debug_base = 0;
3001 info->debug_loader_offset_p = 0;
3002 info->debug_loader_offset = 0;
3003 xfree (info->debug_loader_name);
3004 info->debug_loader_name = NULL;
3007 /* Clear any bits of ADDR that wouldn't fit in a target-format
3008 data pointer. "Data pointer" here refers to whatever sort of
3009 address the dynamic linker uses to manage its sections. At the
3010 moment, we don't support shared libraries on any processors where
3011 code and data pointers are different sizes.
3013 This isn't really the right solution. What we really need here is
3014 a way to do arithmetic on CORE_ADDR values that respects the
3015 natural pointer/address correspondence. (For example, on the MIPS,
3016 converting a 32-bit pointer to a 64-bit CORE_ADDR requires you to
3017 sign-extend the value. There, simply truncating the bits above
3018 gdbarch_ptr_bit, as we do below, is no good.) This should probably
3019 be a new gdbarch method or something. */
3021 svr4_truncate_ptr (CORE_ADDR addr)
3023 if (gdbarch_ptr_bit (target_gdbarch ()) == sizeof (CORE_ADDR) * 8)
3024 /* We don't need to truncate anything, and the bit twiddling below
3025 will fail due to overflow problems. */
3028 return addr & (((CORE_ADDR) 1 << gdbarch_ptr_bit (target_gdbarch ())) - 1);
3033 svr4_relocate_section_addresses (struct so_list *so,
3034 struct target_section *sec)
3036 bfd *abfd = sec->the_bfd_section->owner;
3038 sec->addr = svr4_truncate_ptr (sec->addr + lm_addr_check (so, abfd));
3039 sec->endaddr = svr4_truncate_ptr (sec->endaddr + lm_addr_check (so, abfd));
3043 /* Architecture-specific operations. */
3045 /* Per-architecture data key. */
3046 static struct gdbarch_data *solib_svr4_data;
3048 struct solib_svr4_ops
3050 /* Return a description of the layout of `struct link_map'. */
3051 struct link_map_offsets *(*fetch_link_map_offsets)(void);
3054 /* Return a default for the architecture-specific operations. */
3057 solib_svr4_init (struct obstack *obstack)
3059 struct solib_svr4_ops *ops;
3061 ops = OBSTACK_ZALLOC (obstack, struct solib_svr4_ops);
3062 ops->fetch_link_map_offsets = NULL;
3066 /* Set the architecture-specific `struct link_map_offsets' fetcher for
3067 GDBARCH to FLMO. Also, install SVR4 solib_ops into GDBARCH. */
3070 set_solib_svr4_fetch_link_map_offsets (struct gdbarch *gdbarch,
3071 struct link_map_offsets *(*flmo) (void))
3073 struct solib_svr4_ops *ops
3074 = (struct solib_svr4_ops *) gdbarch_data (gdbarch, solib_svr4_data);
3076 ops->fetch_link_map_offsets = flmo;
3078 set_solib_ops (gdbarch, &svr4_so_ops);
3081 /* Fetch a link_map_offsets structure using the architecture-specific
3082 `struct link_map_offsets' fetcher. */
3084 static struct link_map_offsets *
3085 svr4_fetch_link_map_offsets (void)
3087 struct solib_svr4_ops *ops
3088 = (struct solib_svr4_ops *) gdbarch_data (target_gdbarch (),
3091 gdb_assert (ops->fetch_link_map_offsets);
3092 return ops->fetch_link_map_offsets ();
3095 /* Return 1 if a link map offset fetcher has been defined, 0 otherwise. */
3098 svr4_have_link_map_offsets (void)
3100 struct solib_svr4_ops *ops
3101 = (struct solib_svr4_ops *) gdbarch_data (target_gdbarch (),
3104 return (ops->fetch_link_map_offsets != NULL);
3108 /* Most OS'es that have SVR4-style ELF dynamic libraries define a
3109 `struct r_debug' and a `struct link_map' that are binary compatible
3110 with the origional SVR4 implementation. */
3112 /* Fetch (and possibly build) an appropriate `struct link_map_offsets'
3113 for an ILP32 SVR4 system. */
3115 struct link_map_offsets *
3116 svr4_ilp32_fetch_link_map_offsets (void)
3118 static struct link_map_offsets lmo;
3119 static struct link_map_offsets *lmp = NULL;
3125 lmo.r_version_offset = 0;
3126 lmo.r_version_size = 4;
3127 lmo.r_map_offset = 4;
3128 lmo.r_brk_offset = 8;
3129 lmo.r_ldsomap_offset = 20;
3131 /* Everything we need is in the first 20 bytes. */
3132 lmo.link_map_size = 20;
3133 lmo.l_addr_offset = 0;
3134 lmo.l_name_offset = 4;
3135 lmo.l_ld_offset = 8;
3136 lmo.l_next_offset = 12;
3137 lmo.l_prev_offset = 16;
3143 /* Fetch (and possibly build) an appropriate `struct link_map_offsets'
3144 for an LP64 SVR4 system. */
3146 struct link_map_offsets *
3147 svr4_lp64_fetch_link_map_offsets (void)
3149 static struct link_map_offsets lmo;
3150 static struct link_map_offsets *lmp = NULL;
3156 lmo.r_version_offset = 0;
3157 lmo.r_version_size = 4;
3158 lmo.r_map_offset = 8;
3159 lmo.r_brk_offset = 16;
3160 lmo.r_ldsomap_offset = 40;
3162 /* Everything we need is in the first 40 bytes. */
3163 lmo.link_map_size = 40;
3164 lmo.l_addr_offset = 0;
3165 lmo.l_name_offset = 8;
3166 lmo.l_ld_offset = 16;
3167 lmo.l_next_offset = 24;
3168 lmo.l_prev_offset = 32;
3175 struct target_so_ops svr4_so_ops;
3177 /* Lookup global symbol for ELF DSOs linked with -Bsymbolic. Those DSOs have a
3178 different rule for symbol lookup. The lookup begins here in the DSO, not in
3179 the main executable. */
3181 static struct block_symbol
3182 elf_lookup_lib_symbol (struct objfile *objfile,
3184 const domain_enum domain)
3188 if (objfile == symfile_objfile)
3192 /* OBJFILE should have been passed as the non-debug one. */
3193 gdb_assert (objfile->separate_debug_objfile_backlink == NULL);
3195 abfd = objfile->obfd;
3198 if (abfd == NULL || scan_dyntag (DT_SYMBOLIC, abfd, NULL, NULL) != 1)
3199 return (struct block_symbol) {NULL, NULL};
3201 return lookup_global_symbol_from_objfile (objfile, name, domain);
3205 _initialize_svr4_solib (void)
3207 solib_svr4_data = gdbarch_data_register_pre_init (solib_svr4_init);
3208 solib_svr4_pspace_data
3209 = register_program_space_data_with_cleanup (NULL, svr4_pspace_data_cleanup);
3211 svr4_so_ops.relocate_section_addresses = svr4_relocate_section_addresses;
3212 svr4_so_ops.free_so = svr4_free_so;
3213 svr4_so_ops.clear_so = svr4_clear_so;
3214 svr4_so_ops.clear_solib = svr4_clear_solib;
3215 svr4_so_ops.solib_create_inferior_hook = svr4_solib_create_inferior_hook;
3216 svr4_so_ops.current_sos = svr4_current_sos;
3217 svr4_so_ops.open_symbol_file_object = open_symbol_file_object;
3218 svr4_so_ops.in_dynsym_resolve_code = svr4_in_dynsym_resolve_code;
3219 svr4_so_ops.bfd_open = solib_bfd_open;
3220 svr4_so_ops.lookup_lib_global_symbol = elf_lookup_lib_symbol;
3221 svr4_so_ops.same = svr4_same;
3222 svr4_so_ops.keep_data_in_core = svr4_keep_data_in_core;
3223 svr4_so_ops.update_breakpoints = svr4_update_solib_event_breakpoints;
3224 svr4_so_ops.handle_event = svr4_handle_solib_event;