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https://sourceware.org/git/binutils-gdb.git
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caa429d81a
I noticed that elfread.c always allocates a dbx_symfile_info, even though this is only ever needed in the unusual case of reading stabs in ELF. This patch moves the allocation into dbxread.c, and applies the same treatment to similar code in coffread.c. Regression tested on x86-64 Fedora 29. gdb/ChangeLog 2019-06-10 Tom Tromey <tromey@adacore.com> * elfread.c (elf_read_minimal_symbols): Don't set the dbx objfile data. (elf_new_init): Don't call stabsread_new_init. * dbxread.c (coffstab_build_psymtabs): Set dbx objfile data. (elfstab_build_psymtabs): Likewise. Call stabsread_new_init. * coffread.c (coff_symfile_init): Don't set the dbx objfile data.
1456 lines
46 KiB
C
1456 lines
46 KiB
C
/* Read ELF (Executable and Linking Format) object files for GDB.
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Copyright (C) 1991-2019 Free Software Foundation, Inc.
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Written by Fred Fish at Cygnus Support.
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This file is part of GDB.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>. */
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#include "defs.h"
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#include "bfd.h"
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#include "elf-bfd.h"
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#include "elf/common.h"
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#include "elf/internal.h"
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#include "elf/mips.h"
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#include "symtab.h"
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#include "symfile.h"
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#include "objfiles.h"
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#include "stabsread.h"
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#include "complaints.h"
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#include "demangle.h"
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#include "psympriv.h"
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#include "filenames.h"
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#include "probe.h"
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#include "arch-utils.h"
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#include "gdbtypes.h"
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#include "value.h"
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#include "infcall.h"
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#include "gdbthread.h"
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#include "inferior.h"
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#include "regcache.h"
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#include "bcache.h"
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#include "gdb_bfd.h"
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#include "build-id.h"
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#include "location.h"
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#include "auxv.h"
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#include "mdebugread.h"
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/* Forward declarations. */
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extern const struct sym_fns elf_sym_fns_gdb_index;
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extern const struct sym_fns elf_sym_fns_debug_names;
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extern const struct sym_fns elf_sym_fns_lazy_psyms;
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/* The struct elfinfo is available only during ELF symbol table and
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psymtab reading. It is destroyed at the completion of psymtab-reading.
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It's local to elf_symfile_read. */
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struct elfinfo
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{
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asection *stabsect; /* Section pointer for .stab section */
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asection *mdebugsect; /* Section pointer for .mdebug section */
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};
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/* Type for per-BFD data. */
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typedef std::vector<std::unique_ptr<probe>> elfread_data;
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/* Per-BFD data for probe info. */
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static const struct bfd_key<elfread_data> probe_key;
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/* Minimal symbols located at the GOT entries for .plt - that is the real
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pointer where the given entry will jump to. It gets updated by the real
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function address during lazy ld.so resolving in the inferior. These
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minimal symbols are indexed for <tab>-completion. */
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#define SYMBOL_GOT_PLT_SUFFIX "@got.plt"
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/* Locate the segments in ABFD. */
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static struct symfile_segment_data *
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elf_symfile_segments (bfd *abfd)
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{
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Elf_Internal_Phdr *phdrs, **segments;
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long phdrs_size;
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int num_phdrs, num_segments, num_sections, i;
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asection *sect;
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struct symfile_segment_data *data;
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phdrs_size = bfd_get_elf_phdr_upper_bound (abfd);
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if (phdrs_size == -1)
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return NULL;
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phdrs = (Elf_Internal_Phdr *) alloca (phdrs_size);
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num_phdrs = bfd_get_elf_phdrs (abfd, phdrs);
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if (num_phdrs == -1)
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return NULL;
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num_segments = 0;
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segments = XALLOCAVEC (Elf_Internal_Phdr *, num_phdrs);
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for (i = 0; i < num_phdrs; i++)
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if (phdrs[i].p_type == PT_LOAD)
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segments[num_segments++] = &phdrs[i];
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if (num_segments == 0)
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return NULL;
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data = XCNEW (struct symfile_segment_data);
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data->num_segments = num_segments;
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data->segment_bases = XCNEWVEC (CORE_ADDR, num_segments);
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data->segment_sizes = XCNEWVEC (CORE_ADDR, num_segments);
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for (i = 0; i < num_segments; i++)
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{
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data->segment_bases[i] = segments[i]->p_vaddr;
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data->segment_sizes[i] = segments[i]->p_memsz;
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}
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num_sections = bfd_count_sections (abfd);
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data->segment_info = XCNEWVEC (int, num_sections);
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for (i = 0, sect = abfd->sections; sect != NULL; i++, sect = sect->next)
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{
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int j;
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if ((bfd_get_section_flags (abfd, sect) & SEC_ALLOC) == 0)
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continue;
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Elf_Internal_Shdr *this_hdr = &elf_section_data (sect)->this_hdr;
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for (j = 0; j < num_segments; j++)
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if (ELF_SECTION_IN_SEGMENT (this_hdr, segments[j]))
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{
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data->segment_info[i] = j + 1;
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break;
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}
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/* We should have found a segment for every non-empty section.
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If we haven't, we will not relocate this section by any
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offsets we apply to the segments. As an exception, do not
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warn about SHT_NOBITS sections; in normal ELF execution
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environments, SHT_NOBITS means zero-initialized and belongs
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in a segment, but in no-OS environments some tools (e.g. ARM
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RealView) use SHT_NOBITS for uninitialized data. Since it is
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uninitialized, it doesn't need a program header. Such
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binaries are not relocatable. */
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if (bfd_get_section_size (sect) > 0 && j == num_segments
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&& (bfd_get_section_flags (abfd, sect) & SEC_LOAD) != 0)
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warning (_("Loadable section \"%s\" outside of ELF segments"),
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bfd_section_name (abfd, sect));
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}
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return data;
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}
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/* We are called once per section from elf_symfile_read. We
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need to examine each section we are passed, check to see
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if it is something we are interested in processing, and
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if so, stash away some access information for the section.
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For now we recognize the dwarf debug information sections and
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line number sections from matching their section names. The
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ELF definition is no real help here since it has no direct
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knowledge of DWARF (by design, so any debugging format can be
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used).
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We also recognize the ".stab" sections used by the Sun compilers
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released with Solaris 2.
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FIXME: The section names should not be hardwired strings (what
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should they be? I don't think most object file formats have enough
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section flags to specify what kind of debug section it is.
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-kingdon). */
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static void
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elf_locate_sections (bfd *ignore_abfd, asection *sectp, void *eip)
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{
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struct elfinfo *ei;
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ei = (struct elfinfo *) eip;
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if (strcmp (sectp->name, ".stab") == 0)
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{
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ei->stabsect = sectp;
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}
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else if (strcmp (sectp->name, ".mdebug") == 0)
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{
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ei->mdebugsect = sectp;
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}
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}
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static struct minimal_symbol *
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record_minimal_symbol (minimal_symbol_reader &reader,
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const char *name, int name_len, bool copy_name,
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CORE_ADDR address,
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enum minimal_symbol_type ms_type,
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asection *bfd_section, struct objfile *objfile)
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{
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struct gdbarch *gdbarch = get_objfile_arch (objfile);
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if (ms_type == mst_text || ms_type == mst_file_text
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|| ms_type == mst_text_gnu_ifunc)
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address = gdbarch_addr_bits_remove (gdbarch, address);
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return reader.record_full (name, name_len, copy_name, address,
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ms_type,
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gdb_bfd_section_index (objfile->obfd,
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bfd_section));
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}
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/* Read the symbol table of an ELF file.
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Given an objfile, a symbol table, and a flag indicating whether the
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symbol table contains regular, dynamic, or synthetic symbols, add all
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the global function and data symbols to the minimal symbol table.
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In stabs-in-ELF, as implemented by Sun, there are some local symbols
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defined in the ELF symbol table, which can be used to locate
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the beginnings of sections from each ".o" file that was linked to
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form the executable objfile. We gather any such info and record it
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in data structures hung off the objfile's private data. */
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#define ST_REGULAR 0
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#define ST_DYNAMIC 1
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#define ST_SYNTHETIC 2
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static void
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elf_symtab_read (minimal_symbol_reader &reader,
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struct objfile *objfile, int type,
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long number_of_symbols, asymbol **symbol_table,
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bool copy_names)
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{
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struct gdbarch *gdbarch = get_objfile_arch (objfile);
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asymbol *sym;
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long i;
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CORE_ADDR symaddr;
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enum minimal_symbol_type ms_type;
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/* Name of the last file symbol. This is either a constant string or is
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saved on the objfile's filename cache. */
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const char *filesymname = "";
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int stripped = (bfd_get_symcount (objfile->obfd) == 0);
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int elf_make_msymbol_special_p
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= gdbarch_elf_make_msymbol_special_p (gdbarch);
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for (i = 0; i < number_of_symbols; i++)
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{
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sym = symbol_table[i];
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if (sym->name == NULL || *sym->name == '\0')
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{
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/* Skip names that don't exist (shouldn't happen), or names
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that are null strings (may happen). */
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continue;
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}
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/* Skip "special" symbols, e.g. ARM mapping symbols. These are
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symbols which do not correspond to objects in the symbol table,
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but have some other target-specific meaning. */
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if (bfd_is_target_special_symbol (objfile->obfd, sym))
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{
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if (gdbarch_record_special_symbol_p (gdbarch))
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gdbarch_record_special_symbol (gdbarch, objfile, sym);
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continue;
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}
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if (type == ST_DYNAMIC
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&& sym->section == bfd_und_section_ptr
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&& (sym->flags & BSF_FUNCTION))
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{
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struct minimal_symbol *msym;
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bfd *abfd = objfile->obfd;
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asection *sect;
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/* Symbol is a reference to a function defined in
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a shared library.
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If its value is non zero then it is usually the address
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of the corresponding entry in the procedure linkage table,
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plus the desired section offset.
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If its value is zero then the dynamic linker has to resolve
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the symbol. We are unable to find any meaningful address
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for this symbol in the executable file, so we skip it. */
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symaddr = sym->value;
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if (symaddr == 0)
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continue;
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/* sym->section is the undefined section. However, we want to
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record the section where the PLT stub resides with the
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minimal symbol. Search the section table for the one that
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covers the stub's address. */
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for (sect = abfd->sections; sect != NULL; sect = sect->next)
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{
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if ((bfd_get_section_flags (abfd, sect) & SEC_ALLOC) == 0)
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continue;
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if (symaddr >= bfd_get_section_vma (abfd, sect)
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&& symaddr < bfd_get_section_vma (abfd, sect)
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+ bfd_get_section_size (sect))
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break;
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}
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if (!sect)
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continue;
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/* On ia64-hpux, we have discovered that the system linker
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adds undefined symbols with nonzero addresses that cannot
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be right (their address points inside the code of another
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function in the .text section). This creates problems
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when trying to determine which symbol corresponds to
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a given address.
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We try to detect those buggy symbols by checking which
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section we think they correspond to. Normally, PLT symbols
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are stored inside their own section, and the typical name
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for that section is ".plt". So, if there is a ".plt"
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section, and yet the section name of our symbol does not
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start with ".plt", we ignore that symbol. */
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if (!startswith (sect->name, ".plt")
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&& bfd_get_section_by_name (abfd, ".plt") != NULL)
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continue;
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msym = record_minimal_symbol
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(reader, sym->name, strlen (sym->name), copy_names,
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symaddr, mst_solib_trampoline, sect, objfile);
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if (msym != NULL)
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{
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msym->filename = filesymname;
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if (elf_make_msymbol_special_p)
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gdbarch_elf_make_msymbol_special (gdbarch, sym, msym);
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}
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continue;
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}
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/* If it is a nonstripped executable, do not enter dynamic
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symbols, as the dynamic symbol table is usually a subset
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of the main symbol table. */
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if (type == ST_DYNAMIC && !stripped)
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continue;
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if (sym->flags & BSF_FILE)
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{
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filesymname
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= ((const char *) objfile->per_bfd->filename_cache.insert
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(sym->name, strlen (sym->name) + 1));
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}
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else if (sym->flags & BSF_SECTION_SYM)
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continue;
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else if (sym->flags & (BSF_GLOBAL | BSF_LOCAL | BSF_WEAK
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| BSF_GNU_UNIQUE))
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{
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struct minimal_symbol *msym;
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/* Select global/local/weak symbols. Note that bfd puts abs
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symbols in their own section, so all symbols we are
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interested in will have a section. */
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/* Bfd symbols are section relative. */
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symaddr = sym->value + sym->section->vma;
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/* For non-absolute symbols, use the type of the section
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they are relative to, to intuit text/data. Bfd provides
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no way of figuring this out for absolute symbols. */
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if (sym->section == bfd_abs_section_ptr)
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{
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/* This is a hack to get the minimal symbol type
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right for Irix 5, which has absolute addresses
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with special section indices for dynamic symbols.
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NOTE: uweigand-20071112: Synthetic symbols do not
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have an ELF-private part, so do not touch those. */
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unsigned int shndx = type == ST_SYNTHETIC ? 0 :
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((elf_symbol_type *) sym)->internal_elf_sym.st_shndx;
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switch (shndx)
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{
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case SHN_MIPS_TEXT:
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ms_type = mst_text;
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break;
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case SHN_MIPS_DATA:
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ms_type = mst_data;
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break;
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case SHN_MIPS_ACOMMON:
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ms_type = mst_bss;
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break;
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default:
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ms_type = mst_abs;
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}
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/* If it is an Irix dynamic symbol, skip section name
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symbols, relocate all others by section offset. */
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if (ms_type != mst_abs)
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{
|
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if (sym->name[0] == '.')
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continue;
|
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}
|
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}
|
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else if (sym->section->flags & SEC_CODE)
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{
|
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if (sym->flags & (BSF_GLOBAL | BSF_WEAK | BSF_GNU_UNIQUE))
|
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{
|
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if (sym->flags & BSF_GNU_INDIRECT_FUNCTION)
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ms_type = mst_text_gnu_ifunc;
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||
else
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||
ms_type = mst_text;
|
||
}
|
||
/* The BSF_SYNTHETIC check is there to omit ppc64 function
|
||
descriptors mistaken for static functions starting with 'L'.
|
||
*/
|
||
else if ((sym->name[0] == '.' && sym->name[1] == 'L'
|
||
&& (sym->flags & BSF_SYNTHETIC) == 0)
|
||
|| ((sym->flags & BSF_LOCAL)
|
||
&& sym->name[0] == '$'
|
||
&& sym->name[1] == 'L'))
|
||
/* Looks like a compiler-generated label. Skip
|
||
it. The assembler should be skipping these (to
|
||
keep executables small), but apparently with
|
||
gcc on the (deleted) delta m88k SVR4, it loses.
|
||
So to have us check too should be harmless (but
|
||
I encourage people to fix this in the assembler
|
||
instead of adding checks here). */
|
||
continue;
|
||
else
|
||
{
|
||
ms_type = mst_file_text;
|
||
}
|
||
}
|
||
else if (sym->section->flags & SEC_ALLOC)
|
||
{
|
||
if (sym->flags & (BSF_GLOBAL | BSF_WEAK | BSF_GNU_UNIQUE))
|
||
{
|
||
if (sym->flags & BSF_GNU_INDIRECT_FUNCTION)
|
||
{
|
||
ms_type = mst_data_gnu_ifunc;
|
||
}
|
||
else if (sym->section->flags & SEC_LOAD)
|
||
{
|
||
ms_type = mst_data;
|
||
}
|
||
else
|
||
{
|
||
ms_type = mst_bss;
|
||
}
|
||
}
|
||
else if (sym->flags & BSF_LOCAL)
|
||
{
|
||
if (sym->section->flags & SEC_LOAD)
|
||
{
|
||
ms_type = mst_file_data;
|
||
}
|
||
else
|
||
{
|
||
ms_type = mst_file_bss;
|
||
}
|
||
}
|
||
else
|
||
{
|
||
ms_type = mst_unknown;
|
||
}
|
||
}
|
||
else
|
||
{
|
||
/* FIXME: Solaris2 shared libraries include lots of
|
||
odd "absolute" and "undefined" symbols, that play
|
||
hob with actions like finding what function the PC
|
||
is in. Ignore them if they aren't text, data, or bss. */
|
||
/* ms_type = mst_unknown; */
|
||
continue; /* Skip this symbol. */
|
||
}
|
||
msym = record_minimal_symbol
|
||
(reader, sym->name, strlen (sym->name), copy_names, symaddr,
|
||
ms_type, sym->section, objfile);
|
||
|
||
if (msym)
|
||
{
|
||
/* NOTE: uweigand-20071112: A synthetic symbol does not have an
|
||
ELF-private part. */
|
||
if (type != ST_SYNTHETIC)
|
||
{
|
||
/* Pass symbol size field in via BFD. FIXME!!! */
|
||
elf_symbol_type *elf_sym = (elf_symbol_type *) sym;
|
||
SET_MSYMBOL_SIZE (msym, elf_sym->internal_elf_sym.st_size);
|
||
}
|
||
|
||
msym->filename = filesymname;
|
||
if (elf_make_msymbol_special_p)
|
||
gdbarch_elf_make_msymbol_special (gdbarch, sym, msym);
|
||
}
|
||
|
||
/* If we see a default versioned symbol, install it under
|
||
its version-less name. */
|
||
if (msym != NULL)
|
||
{
|
||
const char *atsign = strchr (sym->name, '@');
|
||
|
||
if (atsign != NULL && atsign[1] == '@' && atsign > sym->name)
|
||
{
|
||
int len = atsign - sym->name;
|
||
|
||
record_minimal_symbol (reader, sym->name, len, true, symaddr,
|
||
ms_type, sym->section, objfile);
|
||
}
|
||
}
|
||
|
||
/* For @plt symbols, also record a trampoline to the
|
||
destination symbol. The @plt symbol will be used in
|
||
disassembly, and the trampoline will be used when we are
|
||
trying to find the target. */
|
||
if (msym && ms_type == mst_text && type == ST_SYNTHETIC)
|
||
{
|
||
int len = strlen (sym->name);
|
||
|
||
if (len > 4 && strcmp (sym->name + len - 4, "@plt") == 0)
|
||
{
|
||
struct minimal_symbol *mtramp;
|
||
|
||
mtramp = record_minimal_symbol (reader, sym->name, len - 4,
|
||
true, symaddr,
|
||
mst_solib_trampoline,
|
||
sym->section, objfile);
|
||
if (mtramp)
|
||
{
|
||
SET_MSYMBOL_SIZE (mtramp, MSYMBOL_SIZE (msym));
|
||
mtramp->created_by_gdb = 1;
|
||
mtramp->filename = filesymname;
|
||
if (elf_make_msymbol_special_p)
|
||
gdbarch_elf_make_msymbol_special (gdbarch,
|
||
sym, mtramp);
|
||
}
|
||
}
|
||
}
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Build minimal symbols named `function@got.plt' (see SYMBOL_GOT_PLT_SUFFIX)
|
||
for later look ups of which function to call when user requests
|
||
a STT_GNU_IFUNC function. As the STT_GNU_IFUNC type is found at the target
|
||
library defining `function' we cannot yet know while reading OBJFILE which
|
||
of the SYMBOL_GOT_PLT_SUFFIX entries will be needed and later
|
||
DYN_SYMBOL_TABLE is no longer easily available for OBJFILE. */
|
||
|
||
static void
|
||
elf_rel_plt_read (minimal_symbol_reader &reader,
|
||
struct objfile *objfile, asymbol **dyn_symbol_table)
|
||
{
|
||
bfd *obfd = objfile->obfd;
|
||
const struct elf_backend_data *bed = get_elf_backend_data (obfd);
|
||
asection *relplt, *got_plt;
|
||
bfd_size_type reloc_count, reloc;
|
||
struct gdbarch *gdbarch = get_objfile_arch (objfile);
|
||
struct type *ptr_type = builtin_type (gdbarch)->builtin_data_ptr;
|
||
size_t ptr_size = TYPE_LENGTH (ptr_type);
|
||
|
||
if (objfile->separate_debug_objfile_backlink)
|
||
return;
|
||
|
||
got_plt = bfd_get_section_by_name (obfd, ".got.plt");
|
||
if (got_plt == NULL)
|
||
{
|
||
/* For platforms where there is no separate .got.plt. */
|
||
got_plt = bfd_get_section_by_name (obfd, ".got");
|
||
if (got_plt == NULL)
|
||
return;
|
||
}
|
||
|
||
/* Depending on system, we may find jump slots in a relocation
|
||
section for either .got.plt or .plt. */
|
||
asection *plt = bfd_get_section_by_name (obfd, ".plt");
|
||
int plt_elf_idx = (plt != NULL) ? elf_section_data (plt)->this_idx : -1;
|
||
|
||
int got_plt_elf_idx = elf_section_data (got_plt)->this_idx;
|
||
|
||
/* This search algorithm is from _bfd_elf_canonicalize_dynamic_reloc. */
|
||
for (relplt = obfd->sections; relplt != NULL; relplt = relplt->next)
|
||
{
|
||
const auto &this_hdr = elf_section_data (relplt)->this_hdr;
|
||
|
||
if (this_hdr.sh_type == SHT_REL || this_hdr.sh_type == SHT_RELA)
|
||
{
|
||
if (this_hdr.sh_info == plt_elf_idx
|
||
|| this_hdr.sh_info == got_plt_elf_idx)
|
||
break;
|
||
}
|
||
}
|
||
if (relplt == NULL)
|
||
return;
|
||
|
||
if (! bed->s->slurp_reloc_table (obfd, relplt, dyn_symbol_table, TRUE))
|
||
return;
|
||
|
||
std::string string_buffer;
|
||
|
||
/* Does ADDRESS reside in SECTION of OBFD? */
|
||
auto within_section = [obfd] (asection *section, CORE_ADDR address)
|
||
{
|
||
if (section == NULL)
|
||
return false;
|
||
|
||
return (bfd_get_section_vma (obfd, section) <= address
|
||
&& (address < bfd_get_section_vma (obfd, section)
|
||
+ bfd_get_section_size (section)));
|
||
};
|
||
|
||
reloc_count = relplt->size / elf_section_data (relplt)->this_hdr.sh_entsize;
|
||
for (reloc = 0; reloc < reloc_count; reloc++)
|
||
{
|
||
const char *name;
|
||
struct minimal_symbol *msym;
|
||
CORE_ADDR address;
|
||
const char *got_suffix = SYMBOL_GOT_PLT_SUFFIX;
|
||
const size_t got_suffix_len = strlen (SYMBOL_GOT_PLT_SUFFIX);
|
||
|
||
name = bfd_asymbol_name (*relplt->relocation[reloc].sym_ptr_ptr);
|
||
address = relplt->relocation[reloc].address;
|
||
|
||
asection *msym_section;
|
||
|
||
/* Does the pointer reside in either the .got.plt or .plt
|
||
sections? */
|
||
if (within_section (got_plt, address))
|
||
msym_section = got_plt;
|
||
else if (within_section (plt, address))
|
||
msym_section = plt;
|
||
else
|
||
continue;
|
||
|
||
/* We cannot check if NAME is a reference to
|
||
mst_text_gnu_ifunc/mst_data_gnu_ifunc as in OBJFILE the
|
||
symbol is undefined and the objfile having NAME defined may
|
||
not yet have been loaded. */
|
||
|
||
string_buffer.assign (name);
|
||
string_buffer.append (got_suffix, got_suffix + got_suffix_len);
|
||
|
||
msym = record_minimal_symbol (reader, string_buffer.c_str (),
|
||
string_buffer.size (),
|
||
true, address, mst_slot_got_plt,
|
||
msym_section, objfile);
|
||
if (msym)
|
||
SET_MSYMBOL_SIZE (msym, ptr_size);
|
||
}
|
||
}
|
||
|
||
/* The data pointer is htab_t for gnu_ifunc_record_cache_unchecked. */
|
||
|
||
static const struct objfile_key<htab, htab_deleter>
|
||
elf_objfile_gnu_ifunc_cache_data;
|
||
|
||
/* Map function names to CORE_ADDR in elf_objfile_gnu_ifunc_cache_data. */
|
||
|
||
struct elf_gnu_ifunc_cache
|
||
{
|
||
/* This is always a function entry address, not a function descriptor. */
|
||
CORE_ADDR addr;
|
||
|
||
char name[1];
|
||
};
|
||
|
||
/* htab_hash for elf_objfile_gnu_ifunc_cache_data. */
|
||
|
||
static hashval_t
|
||
elf_gnu_ifunc_cache_hash (const void *a_voidp)
|
||
{
|
||
const struct elf_gnu_ifunc_cache *a
|
||
= (const struct elf_gnu_ifunc_cache *) a_voidp;
|
||
|
||
return htab_hash_string (a->name);
|
||
}
|
||
|
||
/* htab_eq for elf_objfile_gnu_ifunc_cache_data. */
|
||
|
||
static int
|
||
elf_gnu_ifunc_cache_eq (const void *a_voidp, const void *b_voidp)
|
||
{
|
||
const struct elf_gnu_ifunc_cache *a
|
||
= (const struct elf_gnu_ifunc_cache *) a_voidp;
|
||
const struct elf_gnu_ifunc_cache *b
|
||
= (const struct elf_gnu_ifunc_cache *) b_voidp;
|
||
|
||
return strcmp (a->name, b->name) == 0;
|
||
}
|
||
|
||
/* Record the target function address of a STT_GNU_IFUNC function NAME is the
|
||
function entry address ADDR. Return 1 if NAME and ADDR are considered as
|
||
valid and therefore they were successfully recorded, return 0 otherwise.
|
||
|
||
Function does not expect a duplicate entry. Use
|
||
elf_gnu_ifunc_resolve_by_cache first to check if the entry for NAME already
|
||
exists. */
|
||
|
||
static int
|
||
elf_gnu_ifunc_record_cache (const char *name, CORE_ADDR addr)
|
||
{
|
||
struct bound_minimal_symbol msym;
|
||
struct objfile *objfile;
|
||
htab_t htab;
|
||
struct elf_gnu_ifunc_cache entry_local, *entry_p;
|
||
void **slot;
|
||
|
||
msym = lookup_minimal_symbol_by_pc (addr);
|
||
if (msym.minsym == NULL)
|
||
return 0;
|
||
if (BMSYMBOL_VALUE_ADDRESS (msym) != addr)
|
||
return 0;
|
||
objfile = msym.objfile;
|
||
|
||
/* If .plt jumps back to .plt the symbol is still deferred for later
|
||
resolution and it has no use for GDB. */
|
||
const char *target_name = MSYMBOL_LINKAGE_NAME (msym.minsym);
|
||
size_t len = strlen (target_name);
|
||
|
||
/* Note we check the symbol's name instead of checking whether the
|
||
symbol is in the .plt section because some systems have @plt
|
||
symbols in the .text section. */
|
||
if (len > 4 && strcmp (target_name + len - 4, "@plt") == 0)
|
||
return 0;
|
||
|
||
htab = elf_objfile_gnu_ifunc_cache_data.get (objfile);
|
||
if (htab == NULL)
|
||
{
|
||
htab = htab_create_alloc (1, elf_gnu_ifunc_cache_hash,
|
||
elf_gnu_ifunc_cache_eq,
|
||
NULL, xcalloc, xfree);
|
||
elf_objfile_gnu_ifunc_cache_data.set (objfile, htab);
|
||
}
|
||
|
||
entry_local.addr = addr;
|
||
obstack_grow (&objfile->objfile_obstack, &entry_local,
|
||
offsetof (struct elf_gnu_ifunc_cache, name));
|
||
obstack_grow_str0 (&objfile->objfile_obstack, name);
|
||
entry_p
|
||
= (struct elf_gnu_ifunc_cache *) obstack_finish (&objfile->objfile_obstack);
|
||
|
||
slot = htab_find_slot (htab, entry_p, INSERT);
|
||
if (*slot != NULL)
|
||
{
|
||
struct elf_gnu_ifunc_cache *entry_found_p
|
||
= (struct elf_gnu_ifunc_cache *) *slot;
|
||
struct gdbarch *gdbarch = get_objfile_arch (objfile);
|
||
|
||
if (entry_found_p->addr != addr)
|
||
{
|
||
/* This case indicates buggy inferior program, the resolved address
|
||
should never change. */
|
||
|
||
warning (_("gnu-indirect-function \"%s\" has changed its resolved "
|
||
"function_address from %s to %s"),
|
||
name, paddress (gdbarch, entry_found_p->addr),
|
||
paddress (gdbarch, addr));
|
||
}
|
||
|
||
/* New ENTRY_P is here leaked/duplicate in the OBJFILE obstack. */
|
||
}
|
||
*slot = entry_p;
|
||
|
||
return 1;
|
||
}
|
||
|
||
/* Try to find the target resolved function entry address of a STT_GNU_IFUNC
|
||
function NAME. If the address is found it is stored to *ADDR_P (if ADDR_P
|
||
is not NULL) and the function returns 1. It returns 0 otherwise.
|
||
|
||
Only the elf_objfile_gnu_ifunc_cache_data hash table is searched by this
|
||
function. */
|
||
|
||
static int
|
||
elf_gnu_ifunc_resolve_by_cache (const char *name, CORE_ADDR *addr_p)
|
||
{
|
||
for (objfile *objfile : current_program_space->objfiles ())
|
||
{
|
||
htab_t htab;
|
||
struct elf_gnu_ifunc_cache *entry_p;
|
||
void **slot;
|
||
|
||
htab = elf_objfile_gnu_ifunc_cache_data.get (objfile);
|
||
if (htab == NULL)
|
||
continue;
|
||
|
||
entry_p = ((struct elf_gnu_ifunc_cache *)
|
||
alloca (sizeof (*entry_p) + strlen (name)));
|
||
strcpy (entry_p->name, name);
|
||
|
||
slot = htab_find_slot (htab, entry_p, NO_INSERT);
|
||
if (slot == NULL)
|
||
continue;
|
||
entry_p = (struct elf_gnu_ifunc_cache *) *slot;
|
||
gdb_assert (entry_p != NULL);
|
||
|
||
if (addr_p)
|
||
*addr_p = entry_p->addr;
|
||
return 1;
|
||
}
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* Try to find the target resolved function entry address of a STT_GNU_IFUNC
|
||
function NAME. If the address is found it is stored to *ADDR_P (if ADDR_P
|
||
is not NULL) and the function returns 1. It returns 0 otherwise.
|
||
|
||
Only the SYMBOL_GOT_PLT_SUFFIX locations are searched by this function.
|
||
elf_gnu_ifunc_resolve_by_cache must have been already called for NAME to
|
||
prevent cache entries duplicates. */
|
||
|
||
static int
|
||
elf_gnu_ifunc_resolve_by_got (const char *name, CORE_ADDR *addr_p)
|
||
{
|
||
char *name_got_plt;
|
||
const size_t got_suffix_len = strlen (SYMBOL_GOT_PLT_SUFFIX);
|
||
|
||
name_got_plt = (char *) alloca (strlen (name) + got_suffix_len + 1);
|
||
sprintf (name_got_plt, "%s" SYMBOL_GOT_PLT_SUFFIX, name);
|
||
|
||
for (objfile *objfile : current_program_space->objfiles ())
|
||
{
|
||
bfd *obfd = objfile->obfd;
|
||
struct gdbarch *gdbarch = get_objfile_arch (objfile);
|
||
struct type *ptr_type = builtin_type (gdbarch)->builtin_data_ptr;
|
||
size_t ptr_size = TYPE_LENGTH (ptr_type);
|
||
CORE_ADDR pointer_address, addr;
|
||
asection *plt;
|
||
gdb_byte *buf = (gdb_byte *) alloca (ptr_size);
|
||
struct bound_minimal_symbol msym;
|
||
|
||
msym = lookup_minimal_symbol (name_got_plt, NULL, objfile);
|
||
if (msym.minsym == NULL)
|
||
continue;
|
||
if (MSYMBOL_TYPE (msym.minsym) != mst_slot_got_plt)
|
||
continue;
|
||
pointer_address = BMSYMBOL_VALUE_ADDRESS (msym);
|
||
|
||
plt = bfd_get_section_by_name (obfd, ".plt");
|
||
if (plt == NULL)
|
||
continue;
|
||
|
||
if (MSYMBOL_SIZE (msym.minsym) != ptr_size)
|
||
continue;
|
||
if (target_read_memory (pointer_address, buf, ptr_size) != 0)
|
||
continue;
|
||
addr = extract_typed_address (buf, ptr_type);
|
||
addr = gdbarch_convert_from_func_ptr_addr (gdbarch, addr,
|
||
current_top_target ());
|
||
addr = gdbarch_addr_bits_remove (gdbarch, addr);
|
||
|
||
if (elf_gnu_ifunc_record_cache (name, addr))
|
||
{
|
||
if (addr_p != NULL)
|
||
*addr_p = addr;
|
||
return 1;
|
||
}
|
||
}
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* Try to find the target resolved function entry address of a STT_GNU_IFUNC
|
||
function NAME. If the address is found it is stored to *ADDR_P (if ADDR_P
|
||
is not NULL) and the function returns 1. It returns 0 otherwise.
|
||
|
||
Both the elf_objfile_gnu_ifunc_cache_data hash table and
|
||
SYMBOL_GOT_PLT_SUFFIX locations are searched by this function. */
|
||
|
||
static int
|
||
elf_gnu_ifunc_resolve_name (const char *name, CORE_ADDR *addr_p)
|
||
{
|
||
if (elf_gnu_ifunc_resolve_by_cache (name, addr_p))
|
||
return 1;
|
||
|
||
if (elf_gnu_ifunc_resolve_by_got (name, addr_p))
|
||
return 1;
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* Call STT_GNU_IFUNC - a function returning addresss of a real function to
|
||
call. PC is theSTT_GNU_IFUNC resolving function entry. The value returned
|
||
is the entry point of the resolved STT_GNU_IFUNC target function to call.
|
||
*/
|
||
|
||
static CORE_ADDR
|
||
elf_gnu_ifunc_resolve_addr (struct gdbarch *gdbarch, CORE_ADDR pc)
|
||
{
|
||
const char *name_at_pc;
|
||
CORE_ADDR start_at_pc, address;
|
||
struct type *func_func_type = builtin_type (gdbarch)->builtin_func_func;
|
||
struct value *function, *address_val;
|
||
CORE_ADDR hwcap = 0;
|
||
struct value *hwcap_val;
|
||
|
||
/* Try first any non-intrusive methods without an inferior call. */
|
||
|
||
if (find_pc_partial_function (pc, &name_at_pc, &start_at_pc, NULL)
|
||
&& start_at_pc == pc)
|
||
{
|
||
if (elf_gnu_ifunc_resolve_name (name_at_pc, &address))
|
||
return address;
|
||
}
|
||
else
|
||
name_at_pc = NULL;
|
||
|
||
function = allocate_value (func_func_type);
|
||
VALUE_LVAL (function) = lval_memory;
|
||
set_value_address (function, pc);
|
||
|
||
/* STT_GNU_IFUNC resolver functions usually receive the HWCAP vector as
|
||
parameter. FUNCTION is the function entry address. ADDRESS may be a
|
||
function descriptor. */
|
||
|
||
target_auxv_search (current_top_target (), AT_HWCAP, &hwcap);
|
||
hwcap_val = value_from_longest (builtin_type (gdbarch)
|
||
->builtin_unsigned_long, hwcap);
|
||
address_val = call_function_by_hand (function, NULL, hwcap_val);
|
||
address = value_as_address (address_val);
|
||
address = gdbarch_convert_from_func_ptr_addr (gdbarch, address, current_top_target ());
|
||
address = gdbarch_addr_bits_remove (gdbarch, address);
|
||
|
||
if (name_at_pc)
|
||
elf_gnu_ifunc_record_cache (name_at_pc, address);
|
||
|
||
return address;
|
||
}
|
||
|
||
/* Handle inferior hit of bp_gnu_ifunc_resolver, see its definition. */
|
||
|
||
static void
|
||
elf_gnu_ifunc_resolver_stop (struct breakpoint *b)
|
||
{
|
||
struct breakpoint *b_return;
|
||
struct frame_info *prev_frame = get_prev_frame (get_current_frame ());
|
||
struct frame_id prev_frame_id = get_stack_frame_id (prev_frame);
|
||
CORE_ADDR prev_pc = get_frame_pc (prev_frame);
|
||
int thread_id = inferior_thread ()->global_num;
|
||
|
||
gdb_assert (b->type == bp_gnu_ifunc_resolver);
|
||
|
||
for (b_return = b->related_breakpoint; b_return != b;
|
||
b_return = b_return->related_breakpoint)
|
||
{
|
||
gdb_assert (b_return->type == bp_gnu_ifunc_resolver_return);
|
||
gdb_assert (b_return->loc != NULL && b_return->loc->next == NULL);
|
||
gdb_assert (frame_id_p (b_return->frame_id));
|
||
|
||
if (b_return->thread == thread_id
|
||
&& b_return->loc->requested_address == prev_pc
|
||
&& frame_id_eq (b_return->frame_id, prev_frame_id))
|
||
break;
|
||
}
|
||
|
||
if (b_return == b)
|
||
{
|
||
/* No need to call find_pc_line for symbols resolving as this is only
|
||
a helper breakpointer never shown to the user. */
|
||
|
||
symtab_and_line sal;
|
||
sal.pspace = current_inferior ()->pspace;
|
||
sal.pc = prev_pc;
|
||
sal.section = find_pc_overlay (sal.pc);
|
||
sal.explicit_pc = 1;
|
||
b_return
|
||
= set_momentary_breakpoint (get_frame_arch (prev_frame), sal,
|
||
prev_frame_id,
|
||
bp_gnu_ifunc_resolver_return).release ();
|
||
|
||
/* set_momentary_breakpoint invalidates PREV_FRAME. */
|
||
prev_frame = NULL;
|
||
|
||
/* Add new b_return to the ring list b->related_breakpoint. */
|
||
gdb_assert (b_return->related_breakpoint == b_return);
|
||
b_return->related_breakpoint = b->related_breakpoint;
|
||
b->related_breakpoint = b_return;
|
||
}
|
||
}
|
||
|
||
/* Handle inferior hit of bp_gnu_ifunc_resolver_return, see its definition. */
|
||
|
||
static void
|
||
elf_gnu_ifunc_resolver_return_stop (struct breakpoint *b)
|
||
{
|
||
thread_info *thread = inferior_thread ();
|
||
struct gdbarch *gdbarch = get_frame_arch (get_current_frame ());
|
||
struct type *func_func_type = builtin_type (gdbarch)->builtin_func_func;
|
||
struct type *value_type = TYPE_TARGET_TYPE (func_func_type);
|
||
struct regcache *regcache = get_thread_regcache (thread);
|
||
struct value *func_func;
|
||
struct value *value;
|
||
CORE_ADDR resolved_address, resolved_pc;
|
||
|
||
gdb_assert (b->type == bp_gnu_ifunc_resolver_return);
|
||
|
||
while (b->related_breakpoint != b)
|
||
{
|
||
struct breakpoint *b_next = b->related_breakpoint;
|
||
|
||
switch (b->type)
|
||
{
|
||
case bp_gnu_ifunc_resolver:
|
||
break;
|
||
case bp_gnu_ifunc_resolver_return:
|
||
delete_breakpoint (b);
|
||
break;
|
||
default:
|
||
internal_error (__FILE__, __LINE__,
|
||
_("handle_inferior_event: Invalid "
|
||
"gnu-indirect-function breakpoint type %d"),
|
||
(int) b->type);
|
||
}
|
||
b = b_next;
|
||
}
|
||
gdb_assert (b->type == bp_gnu_ifunc_resolver);
|
||
gdb_assert (b->loc->next == NULL);
|
||
|
||
func_func = allocate_value (func_func_type);
|
||
VALUE_LVAL (func_func) = lval_memory;
|
||
set_value_address (func_func, b->loc->related_address);
|
||
|
||
value = allocate_value (value_type);
|
||
gdbarch_return_value (gdbarch, func_func, value_type, regcache,
|
||
value_contents_raw (value), NULL);
|
||
resolved_address = value_as_address (value);
|
||
resolved_pc = gdbarch_convert_from_func_ptr_addr (gdbarch,
|
||
resolved_address,
|
||
current_top_target ());
|
||
resolved_pc = gdbarch_addr_bits_remove (gdbarch, resolved_pc);
|
||
|
||
gdb_assert (current_program_space == b->pspace || b->pspace == NULL);
|
||
elf_gnu_ifunc_record_cache (event_location_to_string (b->location.get ()),
|
||
resolved_pc);
|
||
|
||
b->type = bp_breakpoint;
|
||
update_breakpoint_locations (b, current_program_space,
|
||
find_function_start_sal (resolved_pc, NULL, true),
|
||
{});
|
||
}
|
||
|
||
/* A helper function for elf_symfile_read that reads the minimal
|
||
symbols. */
|
||
|
||
static void
|
||
elf_read_minimal_symbols (struct objfile *objfile, int symfile_flags,
|
||
const struct elfinfo *ei)
|
||
{
|
||
bfd *synth_abfd, *abfd = objfile->obfd;
|
||
long symcount = 0, dynsymcount = 0, synthcount, storage_needed;
|
||
asymbol **symbol_table = NULL, **dyn_symbol_table = NULL;
|
||
asymbol *synthsyms;
|
||
|
||
if (symtab_create_debug)
|
||
{
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"Reading minimal symbols of objfile %s ...\n",
|
||
objfile_name (objfile));
|
||
}
|
||
|
||
/* If we already have minsyms, then we can skip some work here.
|
||
However, if there were stabs or mdebug sections, we go ahead and
|
||
redo all the work anyway, because the psym readers for those
|
||
kinds of debuginfo need extra information found here. This can
|
||
go away once all types of symbols are in the per-BFD object. */
|
||
if (objfile->per_bfd->minsyms_read
|
||
&& ei->stabsect == NULL
|
||
&& ei->mdebugsect == NULL)
|
||
{
|
||
if (symtab_create_debug)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"... minimal symbols previously read\n");
|
||
return;
|
||
}
|
||
|
||
minimal_symbol_reader reader (objfile);
|
||
|
||
/* Process the normal ELF symbol table first. */
|
||
|
||
storage_needed = bfd_get_symtab_upper_bound (objfile->obfd);
|
||
if (storage_needed < 0)
|
||
error (_("Can't read symbols from %s: %s"),
|
||
bfd_get_filename (objfile->obfd),
|
||
bfd_errmsg (bfd_get_error ()));
|
||
|
||
if (storage_needed > 0)
|
||
{
|
||
/* Memory gets permanently referenced from ABFD after
|
||
bfd_canonicalize_symtab so it must not get freed before ABFD gets. */
|
||
|
||
symbol_table = (asymbol **) bfd_alloc (abfd, storage_needed);
|
||
symcount = bfd_canonicalize_symtab (objfile->obfd, symbol_table);
|
||
|
||
if (symcount < 0)
|
||
error (_("Can't read symbols from %s: %s"),
|
||
bfd_get_filename (objfile->obfd),
|
||
bfd_errmsg (bfd_get_error ()));
|
||
|
||
elf_symtab_read (reader, objfile, ST_REGULAR, symcount, symbol_table,
|
||
false);
|
||
}
|
||
|
||
/* Add the dynamic symbols. */
|
||
|
||
storage_needed = bfd_get_dynamic_symtab_upper_bound (objfile->obfd);
|
||
|
||
if (storage_needed > 0)
|
||
{
|
||
/* Memory gets permanently referenced from ABFD after
|
||
bfd_get_synthetic_symtab so it must not get freed before ABFD gets.
|
||
It happens only in the case when elf_slurp_reloc_table sees
|
||
asection->relocation NULL. Determining which section is asection is
|
||
done by _bfd_elf_get_synthetic_symtab which is all a bfd
|
||
implementation detail, though. */
|
||
|
||
dyn_symbol_table = (asymbol **) bfd_alloc (abfd, storage_needed);
|
||
dynsymcount = bfd_canonicalize_dynamic_symtab (objfile->obfd,
|
||
dyn_symbol_table);
|
||
|
||
if (dynsymcount < 0)
|
||
error (_("Can't read symbols from %s: %s"),
|
||
bfd_get_filename (objfile->obfd),
|
||
bfd_errmsg (bfd_get_error ()));
|
||
|
||
elf_symtab_read (reader, objfile, ST_DYNAMIC, dynsymcount,
|
||
dyn_symbol_table, false);
|
||
|
||
elf_rel_plt_read (reader, objfile, dyn_symbol_table);
|
||
}
|
||
|
||
/* Contrary to binutils --strip-debug/--only-keep-debug the strip command from
|
||
elfutils (eu-strip) moves even the .symtab section into the .debug file.
|
||
|
||
bfd_get_synthetic_symtab on ppc64 for each function descriptor ELF symbol
|
||
'name' creates a new BSF_SYNTHETIC ELF symbol '.name' with its code
|
||
address. But with eu-strip files bfd_get_synthetic_symtab would fail to
|
||
read the code address from .opd while it reads the .symtab section from
|
||
a separate debug info file as the .opd section is SHT_NOBITS there.
|
||
|
||
With SYNTH_ABFD the .opd section will be read from the original
|
||
backlinked binary where it is valid. */
|
||
|
||
if (objfile->separate_debug_objfile_backlink)
|
||
synth_abfd = objfile->separate_debug_objfile_backlink->obfd;
|
||
else
|
||
synth_abfd = abfd;
|
||
|
||
/* Add synthetic symbols - for instance, names for any PLT entries. */
|
||
|
||
synthcount = bfd_get_synthetic_symtab (synth_abfd, symcount, symbol_table,
|
||
dynsymcount, dyn_symbol_table,
|
||
&synthsyms);
|
||
if (synthcount > 0)
|
||
{
|
||
long i;
|
||
|
||
std::unique_ptr<asymbol *[]>
|
||
synth_symbol_table (new asymbol *[synthcount]);
|
||
for (i = 0; i < synthcount; i++)
|
||
synth_symbol_table[i] = synthsyms + i;
|
||
elf_symtab_read (reader, objfile, ST_SYNTHETIC, synthcount,
|
||
synth_symbol_table.get (), true);
|
||
|
||
xfree (synthsyms);
|
||
synthsyms = NULL;
|
||
}
|
||
|
||
/* Install any minimal symbols that have been collected as the current
|
||
minimal symbols for this objfile. The debug readers below this point
|
||
should not generate new minimal symbols; if they do it's their
|
||
responsibility to install them. "mdebug" appears to be the only one
|
||
which will do this. */
|
||
|
||
reader.install ();
|
||
|
||
if (symtab_create_debug)
|
||
fprintf_unfiltered (gdb_stdlog, "Done reading minimal symbols.\n");
|
||
}
|
||
|
||
/* Scan and build partial symbols for a symbol file.
|
||
We have been initialized by a call to elf_symfile_init, which
|
||
currently does nothing.
|
||
|
||
This function only does the minimum work necessary for letting the
|
||
user "name" things symbolically; it does not read the entire symtab.
|
||
Instead, it reads the external and static symbols and puts them in partial
|
||
symbol tables. When more extensive information is requested of a
|
||
file, the corresponding partial symbol table is mutated into a full
|
||
fledged symbol table by going back and reading the symbols
|
||
for real.
|
||
|
||
We look for sections with specific names, to tell us what debug
|
||
format to look for: FIXME!!!
|
||
|
||
elfstab_build_psymtabs() handles STABS symbols;
|
||
mdebug_build_psymtabs() handles ECOFF debugging information.
|
||
|
||
Note that ELF files have a "minimal" symbol table, which looks a lot
|
||
like a COFF symbol table, but has only the minimal information necessary
|
||
for linking. We process this also, and use the information to
|
||
build gdb's minimal symbol table. This gives us some minimal debugging
|
||
capability even for files compiled without -g. */
|
||
|
||
static void
|
||
elf_symfile_read (struct objfile *objfile, symfile_add_flags symfile_flags)
|
||
{
|
||
bfd *abfd = objfile->obfd;
|
||
struct elfinfo ei;
|
||
|
||
memset ((char *) &ei, 0, sizeof (ei));
|
||
if (!(objfile->flags & OBJF_READNEVER))
|
||
bfd_map_over_sections (abfd, elf_locate_sections, (void *) & ei);
|
||
|
||
elf_read_minimal_symbols (objfile, symfile_flags, &ei);
|
||
|
||
/* ELF debugging information is inserted into the psymtab in the
|
||
order of least informative first - most informative last. Since
|
||
the psymtab table is searched `most recent insertion first' this
|
||
increases the probability that more detailed debug information
|
||
for a section is found.
|
||
|
||
For instance, an object file might contain both .mdebug (XCOFF)
|
||
and .debug_info (DWARF2) sections then .mdebug is inserted first
|
||
(searched last) and DWARF2 is inserted last (searched first). If
|
||
we don't do this then the XCOFF info is found first - for code in
|
||
an included file XCOFF info is useless. */
|
||
|
||
if (ei.mdebugsect)
|
||
{
|
||
const struct ecoff_debug_swap *swap;
|
||
|
||
/* .mdebug section, presumably holding ECOFF debugging
|
||
information. */
|
||
swap = get_elf_backend_data (abfd)->elf_backend_ecoff_debug_swap;
|
||
if (swap)
|
||
elfmdebug_build_psymtabs (objfile, swap, ei.mdebugsect);
|
||
}
|
||
if (ei.stabsect)
|
||
{
|
||
asection *str_sect;
|
||
|
||
/* Stab sections have an associated string table that looks like
|
||
a separate section. */
|
||
str_sect = bfd_get_section_by_name (abfd, ".stabstr");
|
||
|
||
/* FIXME should probably warn about a stab section without a stabstr. */
|
||
if (str_sect)
|
||
elfstab_build_psymtabs (objfile,
|
||
ei.stabsect,
|
||
str_sect->filepos,
|
||
bfd_section_size (abfd, str_sect));
|
||
}
|
||
|
||
if (dwarf2_has_info (objfile, NULL))
|
||
{
|
||
dw_index_kind index_kind;
|
||
|
||
/* elf_sym_fns_gdb_index cannot handle simultaneous non-DWARF
|
||
debug information present in OBJFILE. If there is such debug
|
||
info present never use an index. */
|
||
if (!objfile_has_partial_symbols (objfile)
|
||
&& dwarf2_initialize_objfile (objfile, &index_kind))
|
||
{
|
||
switch (index_kind)
|
||
{
|
||
case dw_index_kind::GDB_INDEX:
|
||
objfile_set_sym_fns (objfile, &elf_sym_fns_gdb_index);
|
||
break;
|
||
case dw_index_kind::DEBUG_NAMES:
|
||
objfile_set_sym_fns (objfile, &elf_sym_fns_debug_names);
|
||
break;
|
||
}
|
||
}
|
||
else
|
||
{
|
||
/* It is ok to do this even if the stabs reader made some
|
||
partial symbols, because OBJF_PSYMTABS_READ has not been
|
||
set, and so our lazy reader function will still be called
|
||
when needed. */
|
||
objfile_set_sym_fns (objfile, &elf_sym_fns_lazy_psyms);
|
||
}
|
||
}
|
||
/* If the file has its own symbol tables it has no separate debug
|
||
info. `.dynsym'/`.symtab' go to MSYMBOLS, `.debug_info' goes to
|
||
SYMTABS/PSYMTABS. `.gnu_debuglink' may no longer be present with
|
||
`.note.gnu.build-id'.
|
||
|
||
.gnu_debugdata is !objfile_has_partial_symbols because it contains only
|
||
.symtab, not .debug_* section. But if we already added .gnu_debugdata as
|
||
an objfile via find_separate_debug_file_in_section there was no separate
|
||
debug info available. Therefore do not attempt to search for another one,
|
||
objfile->separate_debug_objfile->separate_debug_objfile GDB guarantees to
|
||
be NULL and we would possibly violate it. */
|
||
|
||
else if (!objfile_has_partial_symbols (objfile)
|
||
&& objfile->separate_debug_objfile == NULL
|
||
&& objfile->separate_debug_objfile_backlink == NULL)
|
||
{
|
||
std::string debugfile = find_separate_debug_file_by_buildid (objfile);
|
||
|
||
if (debugfile.empty ())
|
||
debugfile = find_separate_debug_file_by_debuglink (objfile);
|
||
|
||
if (!debugfile.empty ())
|
||
{
|
||
gdb_bfd_ref_ptr debug_bfd (symfile_bfd_open (debugfile.c_str ()));
|
||
|
||
symbol_file_add_separate (debug_bfd.get (), debugfile.c_str (),
|
||
symfile_flags, objfile);
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Callback to lazily read psymtabs. */
|
||
|
||
static void
|
||
read_psyms (struct objfile *objfile)
|
||
{
|
||
if (dwarf2_has_info (objfile, NULL))
|
||
dwarf2_build_psymtabs (objfile);
|
||
}
|
||
|
||
/* Initialize anything that needs initializing when a completely new symbol
|
||
file is specified (not just adding some symbols from another file, e.g. a
|
||
shared library). */
|
||
|
||
static void
|
||
elf_new_init (struct objfile *ignore)
|
||
{
|
||
}
|
||
|
||
/* Perform any local cleanups required when we are done with a particular
|
||
objfile. I.E, we are in the process of discarding all symbol information
|
||
for an objfile, freeing up all memory held for it, and unlinking the
|
||
objfile struct from the global list of known objfiles. */
|
||
|
||
static void
|
||
elf_symfile_finish (struct objfile *objfile)
|
||
{
|
||
}
|
||
|
||
/* ELF specific initialization routine for reading symbols. */
|
||
|
||
static void
|
||
elf_symfile_init (struct objfile *objfile)
|
||
{
|
||
/* ELF objects may be reordered, so set OBJF_REORDERED. If we
|
||
find this causes a significant slowdown in gdb then we could
|
||
set it in the debug symbol readers only when necessary. */
|
||
objfile->flags |= OBJF_REORDERED;
|
||
}
|
||
|
||
/* Implementation of `sym_get_probes', as documented in symfile.h. */
|
||
|
||
static const elfread_data &
|
||
elf_get_probes (struct objfile *objfile)
|
||
{
|
||
elfread_data *probes_per_bfd = probe_key.get (objfile->obfd);
|
||
|
||
if (probes_per_bfd == NULL)
|
||
{
|
||
probes_per_bfd = probe_key.emplace (objfile->obfd);
|
||
|
||
/* Here we try to gather information about all types of probes from the
|
||
objfile. */
|
||
for (const static_probe_ops *ops : all_static_probe_ops)
|
||
ops->get_probes (probes_per_bfd, objfile);
|
||
}
|
||
|
||
return *probes_per_bfd;
|
||
}
|
||
|
||
|
||
|
||
/* Implementation `sym_probe_fns', as documented in symfile.h. */
|
||
|
||
static const struct sym_probe_fns elf_probe_fns =
|
||
{
|
||
elf_get_probes, /* sym_get_probes */
|
||
};
|
||
|
||
/* Register that we are able to handle ELF object file formats. */
|
||
|
||
static const struct sym_fns elf_sym_fns =
|
||
{
|
||
elf_new_init, /* init anything gbl to entire symtab */
|
||
elf_symfile_init, /* read initial info, setup for sym_read() */
|
||
elf_symfile_read, /* read a symbol file into symtab */
|
||
NULL, /* sym_read_psymbols */
|
||
elf_symfile_finish, /* finished with file, cleanup */
|
||
default_symfile_offsets, /* Translate ext. to int. relocation */
|
||
elf_symfile_segments, /* Get segment information from a file. */
|
||
NULL,
|
||
default_symfile_relocate, /* Relocate a debug section. */
|
||
&elf_probe_fns, /* sym_probe_fns */
|
||
&psym_functions
|
||
};
|
||
|
||
/* The same as elf_sym_fns, but not registered and lazily reads
|
||
psymbols. */
|
||
|
||
const struct sym_fns elf_sym_fns_lazy_psyms =
|
||
{
|
||
elf_new_init, /* init anything gbl to entire symtab */
|
||
elf_symfile_init, /* read initial info, setup for sym_read() */
|
||
elf_symfile_read, /* read a symbol file into symtab */
|
||
read_psyms, /* sym_read_psymbols */
|
||
elf_symfile_finish, /* finished with file, cleanup */
|
||
default_symfile_offsets, /* Translate ext. to int. relocation */
|
||
elf_symfile_segments, /* Get segment information from a file. */
|
||
NULL,
|
||
default_symfile_relocate, /* Relocate a debug section. */
|
||
&elf_probe_fns, /* sym_probe_fns */
|
||
&psym_functions
|
||
};
|
||
|
||
/* The same as elf_sym_fns, but not registered and uses the
|
||
DWARF-specific GNU index rather than psymtab. */
|
||
const struct sym_fns elf_sym_fns_gdb_index =
|
||
{
|
||
elf_new_init, /* init anything gbl to entire symab */
|
||
elf_symfile_init, /* read initial info, setup for sym_red() */
|
||
elf_symfile_read, /* read a symbol file into symtab */
|
||
NULL, /* sym_read_psymbols */
|
||
elf_symfile_finish, /* finished with file, cleanup */
|
||
default_symfile_offsets, /* Translate ext. to int. relocatin */
|
||
elf_symfile_segments, /* Get segment information from a file. */
|
||
NULL,
|
||
default_symfile_relocate, /* Relocate a debug section. */
|
||
&elf_probe_fns, /* sym_probe_fns */
|
||
&dwarf2_gdb_index_functions
|
||
};
|
||
|
||
/* The same as elf_sym_fns, but not registered and uses the
|
||
DWARF-specific .debug_names index rather than psymtab. */
|
||
const struct sym_fns elf_sym_fns_debug_names =
|
||
{
|
||
elf_new_init, /* init anything gbl to entire symab */
|
||
elf_symfile_init, /* read initial info, setup for sym_red() */
|
||
elf_symfile_read, /* read a symbol file into symtab */
|
||
NULL, /* sym_read_psymbols */
|
||
elf_symfile_finish, /* finished with file, cleanup */
|
||
default_symfile_offsets, /* Translate ext. to int. relocatin */
|
||
elf_symfile_segments, /* Get segment information from a file. */
|
||
NULL,
|
||
default_symfile_relocate, /* Relocate a debug section. */
|
||
&elf_probe_fns, /* sym_probe_fns */
|
||
&dwarf2_debug_names_functions
|
||
};
|
||
|
||
/* STT_GNU_IFUNC resolver vector to be installed to gnu_ifunc_fns_p. */
|
||
|
||
static const struct gnu_ifunc_fns elf_gnu_ifunc_fns =
|
||
{
|
||
elf_gnu_ifunc_resolve_addr,
|
||
elf_gnu_ifunc_resolve_name,
|
||
elf_gnu_ifunc_resolver_stop,
|
||
elf_gnu_ifunc_resolver_return_stop
|
||
};
|
||
|
||
void
|
||
_initialize_elfread (void)
|
||
{
|
||
add_symtab_fns (bfd_target_elf_flavour, &elf_sym_fns);
|
||
|
||
gnu_ifunc_fns_p = &elf_gnu_ifunc_fns;
|
||
}
|