| /* Read ELF (Executable and Linking Format) object files for GDB. | |
| Copyright (C) 1991-2022 Free Software Foundation, Inc. | |
| Written by Fred Fish at Cygnus Support. | |
| This file is part of GDB. | |
| This program is free software; you can redistribute it and/or modify | |
| it under the terms of the GNU General Public License as published by | |
| the Free Software Foundation; either version 3 of the License, or | |
| (at your option) any later version. | |
| This program is distributed in the hope that it will be useful, | |
| but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
| GNU General Public License for more details. | |
| You should have received a copy of the GNU General Public License | |
| along with this program. If not, see <http://www.gnu.org/licenses/>. */ | |
| #include "defs.h" | |
| #include "bfd.h" | |
| #include "elf-bfd.h" | |
| #include "elf/common.h" | |
| #include "elf/internal.h" | |
| #include "elf/mips.h" | |
| #include "symtab.h" | |
| #include "symfile.h" | |
| #include "objfiles.h" | |
| #include "stabsread.h" | |
| #include "demangle.h" | |
| #include "psympriv.h" | |
| #include "filenames.h" | |
| #include "probe.h" | |
| #include "arch-utils.h" | |
| #include "gdbtypes.h" | |
| #include "value.h" | |
| #include "infcall.h" | |
| #include "gdbthread.h" | |
| #include "inferior.h" | |
| #include "regcache.h" | |
| #include "bcache.h" | |
| #include "gdb_bfd.h" | |
| #include "build-id.h" | |
| #include "location.h" | |
| #include "auxv.h" | |
| #include "mdebugread.h" | |
| #include "ctfread.h" | |
| #include "gdbsupport/gdb_string_view.h" | |
| #include "gdbsupport/scoped_fd.h" | |
| #include "debuginfod-support.h" | |
| #include "dwarf2/public.h" | |
| /* The struct elfinfo is available only during ELF symbol table and | |
| psymtab reading. It is destroyed at the completion of psymtab-reading. | |
| It's local to elf_symfile_read. */ | |
| struct elfinfo | |
| { | |
| asection *stabsect; /* Section pointer for .stab section */ | |
| asection *mdebugsect; /* Section pointer for .mdebug section */ | |
| asection *ctfsect; /* Section pointer for .ctf section */ | |
| }; | |
| /* Type for per-BFD data. */ | |
| typedef std::vector<std::unique_ptr<probe>> elfread_data; | |
| /* Per-BFD data for probe info. */ | |
| static const struct bfd_key<elfread_data> probe_key; | |
| /* Minimal symbols located at the GOT entries for .plt - that is the real | |
| pointer where the given entry will jump to. It gets updated by the real | |
| function address during lazy ld.so resolving in the inferior. These | |
| minimal symbols are indexed for <tab>-completion. */ | |
| #define SYMBOL_GOT_PLT_SUFFIX "@got.plt" | |
| /* Locate the segments in ABFD. */ | |
| static symfile_segment_data_up | |
| elf_symfile_segments (bfd *abfd) | |
| { | |
| Elf_Internal_Phdr *phdrs, **segments; | |
| long phdrs_size; | |
| int num_phdrs, num_segments, num_sections, i; | |
| asection *sect; | |
| phdrs_size = bfd_get_elf_phdr_upper_bound (abfd); | |
| if (phdrs_size == -1) | |
| return NULL; | |
| phdrs = (Elf_Internal_Phdr *) alloca (phdrs_size); | |
| num_phdrs = bfd_get_elf_phdrs (abfd, phdrs); | |
| if (num_phdrs == -1) | |
| return NULL; | |
| num_segments = 0; | |
| segments = XALLOCAVEC (Elf_Internal_Phdr *, num_phdrs); | |
| for (i = 0; i < num_phdrs; i++) | |
| if (phdrs[i].p_type == PT_LOAD) | |
| segments[num_segments++] = &phdrs[i]; | |
| if (num_segments == 0) | |
| return NULL; | |
| symfile_segment_data_up data (new symfile_segment_data); | |
| data->segments.reserve (num_segments); | |
| for (i = 0; i < num_segments; i++) | |
| data->segments.emplace_back (segments[i]->p_vaddr, segments[i]->p_memsz); | |
| num_sections = bfd_count_sections (abfd); | |
| /* All elements are initialized to 0 (map to no segment). */ | |
| data->segment_info.resize (num_sections); | |
| for (i = 0, sect = abfd->sections; sect != NULL; i++, sect = sect->next) | |
| { | |
| int j; | |
| if ((bfd_section_flags (sect) & SEC_ALLOC) == 0) | |
| continue; | |
| Elf_Internal_Shdr *this_hdr = &elf_section_data (sect)->this_hdr; | |
| for (j = 0; j < num_segments; j++) | |
| if (ELF_SECTION_IN_SEGMENT (this_hdr, segments[j])) | |
| { | |
| data->segment_info[i] = j + 1; | |
| break; | |
| } | |
| /* We should have found a segment for every non-empty section. | |
| If we haven't, we will not relocate this section by any | |
| offsets we apply to the segments. As an exception, do not | |
| warn about SHT_NOBITS sections; in normal ELF execution | |
| environments, SHT_NOBITS means zero-initialized and belongs | |
| in a segment, but in no-OS environments some tools (e.g. ARM | |
| RealView) use SHT_NOBITS for uninitialized data. Since it is | |
| uninitialized, it doesn't need a program header. Such | |
| binaries are not relocatable. */ | |
| /* Exclude debuginfo files from this warning, too, since those | |
| are often not strictly compliant with the standard. See, e.g., | |
| ld/24717 for more discussion. */ | |
| if (!is_debuginfo_file (abfd) | |
| && bfd_section_size (sect) > 0 && j == num_segments | |
| && (bfd_section_flags (sect) & SEC_LOAD) != 0) | |
| warning (_("Loadable section \"%s\" outside of ELF segments\n in %s"), | |
| bfd_section_name (sect), bfd_get_filename (abfd)); | |
| } | |
| return data; | |
| } | |
| /* We are called once per section from elf_symfile_read. We | |
| need to examine each section we are passed, check to see | |
| if it is something we are interested in processing, and | |
| if so, stash away some access information for the section. | |
| For now we recognize the dwarf debug information sections and | |
| line number sections from matching their section names. The | |
| ELF definition is no real help here since it has no direct | |
| knowledge of DWARF (by design, so any debugging format can be | |
| used). | |
| We also recognize the ".stab" sections used by the Sun compilers | |
| released with Solaris 2. | |
| FIXME: The section names should not be hardwired strings (what | |
| should they be? I don't think most object file formats have enough | |
| section flags to specify what kind of debug section it is. | |
| -kingdon). */ | |
| static void | |
| elf_locate_sections (asection *sectp, struct elfinfo *ei) | |
| { | |
| if (strcmp (sectp->name, ".stab") == 0) | |
| { | |
| ei->stabsect = sectp; | |
| } | |
| else if (strcmp (sectp->name, ".mdebug") == 0) | |
| { | |
| ei->mdebugsect = sectp; | |
| } | |
| else if (strcmp (sectp->name, ".ctf") == 0) | |
| { | |
| ei->ctfsect = sectp; | |
| } | |
| } | |
| static struct minimal_symbol * | |
| record_minimal_symbol (minimal_symbol_reader &reader, | |
| gdb::string_view name, bool copy_name, | |
| CORE_ADDR address, | |
| enum minimal_symbol_type ms_type, | |
| asection *bfd_section, struct objfile *objfile) | |
| { | |
| struct gdbarch *gdbarch = objfile->arch (); | |
| if (ms_type == mst_text || ms_type == mst_file_text | |
| || ms_type == mst_text_gnu_ifunc) | |
| address = gdbarch_addr_bits_remove (gdbarch, address); | |
| /* We only setup section information for allocatable sections. Usually | |
| we'd only expect to find msymbols for allocatable sections, but if the | |
| ELF is malformed then this might not be the case. In that case don't | |
| create an msymbol that references an uninitialised section object. */ | |
| int section_index = 0; | |
| if ((bfd_section_flags (bfd_section) & SEC_ALLOC) == SEC_ALLOC) | |
| section_index = gdb_bfd_section_index (objfile->obfd, bfd_section); | |
| struct minimal_symbol *result | |
| = reader.record_full (name, copy_name, address, ms_type, section_index); | |
| if ((objfile->flags & OBJF_MAINLINE) == 0 | |
| && (ms_type == mst_data || ms_type == mst_bss)) | |
| result->maybe_copied = 1; | |
| return result; | |
| } | |
| /* Read the symbol table of an ELF file. | |
| Given an objfile, a symbol table, and a flag indicating whether the | |
| symbol table contains regular, dynamic, or synthetic symbols, add all | |
| the global function and data symbols to the minimal symbol table. | |
| In stabs-in-ELF, as implemented by Sun, there are some local symbols | |
| defined in the ELF symbol table, which can be used to locate | |
| the beginnings of sections from each ".o" file that was linked to | |
| form the executable objfile. We gather any such info and record it | |
| in data structures hung off the objfile's private data. */ | |
| #define ST_REGULAR 0 | |
| #define ST_DYNAMIC 1 | |
| #define ST_SYNTHETIC 2 | |
| static void | |
| elf_symtab_read (minimal_symbol_reader &reader, | |
| struct objfile *objfile, int type, | |
| long number_of_symbols, asymbol **symbol_table, | |
| bool copy_names) | |
| { | |
| struct gdbarch *gdbarch = objfile->arch (); | |
| asymbol *sym; | |
| long i; | |
| CORE_ADDR symaddr; | |
| enum minimal_symbol_type ms_type; | |
| /* Name of the last file symbol. This is either a constant string or is | |
| saved on the objfile's filename cache. */ | |
| const char *filesymname = ""; | |
| int stripped = (bfd_get_symcount (objfile->obfd) == 0); | |
| int elf_make_msymbol_special_p | |
| = gdbarch_elf_make_msymbol_special_p (gdbarch); | |
| for (i = 0; i < number_of_symbols; i++) | |
| { | |
| sym = symbol_table[i]; | |
| if (sym->name == NULL || *sym->name == '\0') | |
| { | |
| /* Skip names that don't exist (shouldn't happen), or names | |
| that are null strings (may happen). */ | |
| continue; | |
| } | |
| elf_symbol_type *elf_sym = (elf_symbol_type *) sym; | |
| /* Skip "special" symbols, e.g. ARM mapping symbols. These are | |
| symbols which do not correspond to objects in the symbol table, | |
| but have some other target-specific meaning. */ | |
| if (bfd_is_target_special_symbol (objfile->obfd, sym)) | |
| { | |
| if (gdbarch_record_special_symbol_p (gdbarch)) | |
| gdbarch_record_special_symbol (gdbarch, objfile, sym); | |
| continue; | |
| } | |
| if (type == ST_DYNAMIC | |
| && sym->section == bfd_und_section_ptr | |
| && (sym->flags & BSF_FUNCTION)) | |
| { | |
| struct minimal_symbol *msym; | |
| bfd *abfd = objfile->obfd; | |
| asection *sect; | |
| /* Symbol is a reference to a function defined in | |
| a shared library. | |
| If its value is non zero then it is usually the address | |
| of the corresponding entry in the procedure linkage table, | |
| plus the desired section offset. | |
| If its value is zero then the dynamic linker has to resolve | |
| the symbol. We are unable to find any meaningful address | |
| for this symbol in the executable file, so we skip it. */ | |
| symaddr = sym->value; | |
| if (symaddr == 0) | |
| continue; | |
| /* sym->section is the undefined section. However, we want to | |
| record the section where the PLT stub resides with the | |
| minimal symbol. Search the section table for the one that | |
| covers the stub's address. */ | |
| for (sect = abfd->sections; sect != NULL; sect = sect->next) | |
| { | |
| if ((bfd_section_flags (sect) & SEC_ALLOC) == 0) | |
| continue; | |
| if (symaddr >= bfd_section_vma (sect) | |
| && symaddr < bfd_section_vma (sect) | |
| + bfd_section_size (sect)) | |
| break; | |
| } | |
| if (!sect) | |
| continue; | |
| /* On ia64-hpux, we have discovered that the system linker | |
| adds undefined symbols with nonzero addresses that cannot | |
| be right (their address points inside the code of another | |
| function in the .text section). This creates problems | |
| when trying to determine which symbol corresponds to | |
| a given address. | |
| We try to detect those buggy symbols by checking which | |
| section we think they correspond to. Normally, PLT symbols | |
| are stored inside their own section, and the typical name | |
| for that section is ".plt". So, if there is a ".plt" | |
| section, and yet the section name of our symbol does not | |
| start with ".plt", we ignore that symbol. */ | |
| if (!startswith (sect->name, ".plt") | |
| && bfd_get_section_by_name (abfd, ".plt") != NULL) | |
| continue; | |
| msym = record_minimal_symbol | |
| (reader, sym->name, copy_names, | |
| symaddr, mst_solib_trampoline, sect, objfile); | |
| if (msym != NULL) | |
| { | |
| msym->filename = filesymname; | |
| if (elf_make_msymbol_special_p) | |
| gdbarch_elf_make_msymbol_special (gdbarch, sym, msym); | |
| } | |
| continue; | |
| } | |
| /* If it is a nonstripped executable, do not enter dynamic | |
| symbols, as the dynamic symbol table is usually a subset | |
| of the main symbol table. */ | |
| if (type == ST_DYNAMIC && !stripped) | |
| continue; | |
| if (sym->flags & BSF_FILE) | |
| filesymname = objfile->intern (sym->name); | |
| else if (sym->flags & BSF_SECTION_SYM) | |
| continue; | |
| else if (sym->flags & (BSF_GLOBAL | BSF_LOCAL | BSF_WEAK | |
| | BSF_GNU_UNIQUE)) | |
| { | |
| struct minimal_symbol *msym; | |
| /* Select global/local/weak symbols. Note that bfd puts abs | |
| symbols in their own section, so all symbols we are | |
| interested in will have a section. */ | |
| /* Bfd symbols are section relative. */ | |
| symaddr = sym->value + sym->section->vma; | |
| /* For non-absolute symbols, use the type of the section | |
| they are relative to, to intuit text/data. Bfd provides | |
| no way of figuring this out for absolute symbols. */ | |
| if (sym->section == bfd_abs_section_ptr) | |
| { | |
| /* This is a hack to get the minimal symbol type | |
| right for Irix 5, which has absolute addresses | |
| with special section indices for dynamic symbols. | |
| NOTE: uweigand-20071112: Synthetic symbols do not | |
| have an ELF-private part, so do not touch those. */ | |
| unsigned int shndx = type == ST_SYNTHETIC ? 0 : | |
| elf_sym->internal_elf_sym.st_shndx; | |
| switch (shndx) | |
| { | |
| case SHN_MIPS_TEXT: | |
| ms_type = mst_text; | |
| break; | |
| case SHN_MIPS_DATA: | |
| ms_type = mst_data; | |
| break; | |
| case SHN_MIPS_ACOMMON: | |
| ms_type = mst_bss; | |
| break; | |
| default: | |
| ms_type = mst_abs; | |
| } | |
| /* If it is an Irix dynamic symbol, skip section name | |
| symbols, relocate all others by section offset. */ | |
| if (ms_type != mst_abs) | |
| { | |
| if (sym->name[0] == '.') | |
| continue; | |
| } | |
| } | |
| else if (sym->section->flags & SEC_CODE) | |
| { | |
| if (sym->flags & (BSF_GLOBAL | BSF_WEAK | BSF_GNU_UNIQUE)) | |
| { | |
| if (sym->flags & BSF_GNU_INDIRECT_FUNCTION) | |
| ms_type = mst_text_gnu_ifunc; | |
| else | |
| 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, 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!!! */ | |
| msym->set_size (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, '@'); | |
| bool is_at_symbol = atsign != nullptr && atsign > sym->name; | |
| bool is_plt = is_at_symbol && strcmp (atsign, "@plt") == 0; | |
| int len = is_at_symbol ? atsign - sym->name : 0; | |
| if (is_at_symbol | |
| && !is_plt | |
| && (elf_sym->version & VERSYM_HIDDEN) == 0) | |
| record_minimal_symbol (reader, | |
| gdb::string_view (sym->name, len), | |
| true, symaddr, ms_type, sym->section, | |
| objfile); | |
| else if (is_plt) | |
| { | |
| /* 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 (ms_type == mst_text && type == ST_SYNTHETIC) | |
| { | |
| struct minimal_symbol *mtramp; | |
| mtramp = record_minimal_symbol | |
| (reader, gdb::string_view (sym->name, len), true, | |
| symaddr, mst_solib_trampoline, sym->section, objfile); | |
| if (mtramp) | |
| { | |
| mtramp->set_size (msym->size()); | |
| 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 = objfile->arch (); | |
| 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_section_vma (section) <= address | |
| && (address < bfd_section_vma (section) | |
| + bfd_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, | |
| true, address, mst_slot_got_plt, | |
| msym_section, objfile); | |
| if (msym) | |
| msym->set_size (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 (msym.value_address () != 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 = msym.minsym->linkage_name (); | |
| 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 = objfile->arch (); | |
| 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 = objfile->arch (); | |
| 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 (msym.minsym->type () != mst_slot_got_plt) | |
| continue; | |
| pointer_address = msym.value_address (); | |
| plt = bfd_get_section_by_name (obfd, ".plt"); | |
| if (plt == NULL) | |
| continue; | |
| if (msym.minsym->size () != 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_inferior ()->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 true. It returns false otherwise. | |
| Both the elf_objfile_gnu_ifunc_cache_data hash table and | |
| SYMBOL_GOT_PLT_SUFFIX locations are searched by this function. */ | |
| static bool | |
| elf_gnu_ifunc_resolve_name (const char *name, CORE_ADDR *addr_p) | |
| { | |
| if (elf_gnu_ifunc_resolve_by_cache (name, addr_p)) | |
| return true; | |
| if (elf_gnu_ifunc_resolve_by_got (name, addr_p)) | |
| return true; | |
| return false; | |
| } | |
| /* 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_inferior ()->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_inferior ()->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 (code_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 (code_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 = (code_breakpoint *) 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).data (), NULL); | |
| resolved_address = value_as_address (value); | |
| resolved_pc = gdbarch_convert_from_func_ptr_addr | |
| (gdbarch, resolved_address, current_inferior ()->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 (b->locspec->to_string (), 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) | |
| { | |
| gdb_printf (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 | |
| && ei->ctfsect == NULL) | |
| { | |
| if (symtab_create_debug) | |
| gdb_printf (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) | |
| gdb_printf (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; | |
| bool has_dwarf2 = true; | |
| memset ((char *) &ei, 0, sizeof (ei)); | |
| if (!(objfile->flags & OBJF_READNEVER)) | |
| { | |
| for (asection *sect : gdb_bfd_sections (abfd)) | |
| elf_locate_sections (sect, &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 (str_sect)); | |
| } | |
| if (dwarf2_has_info (objfile, NULL, true)) | |
| dwarf2_initialize_objfile (objfile); | |
| /* 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->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); | |
| } | |
| else | |
| { | |
| has_dwarf2 = false; | |
| const struct bfd_build_id *build_id = build_id_bfd_get (objfile->obfd); | |
| if (build_id != nullptr) | |
| { | |
| gdb::unique_xmalloc_ptr<char> symfile_path; | |
| scoped_fd fd (debuginfod_debuginfo_query (build_id->data, | |
| build_id->size, | |
| objfile->original_name, | |
| &symfile_path)); | |
| if (fd.get () >= 0) | |
| { | |
| /* File successfully retrieved from server. */ | |
| gdb_bfd_ref_ptr debug_bfd (symfile_bfd_open (symfile_path.get ())); | |
| if (debug_bfd == nullptr) | |
| warning (_("File \"%s\" from debuginfod cannot be opened as bfd"), | |
| objfile->original_name); | |
| else if (build_id_verify (debug_bfd.get (), build_id->size, build_id->data)) | |
| { | |
| symbol_file_add_separate (debug_bfd.get (), symfile_path.get (), | |
| symfile_flags, objfile); | |
| has_dwarf2 = true; | |
| } | |
| } | |
| } | |
| } | |
| } | |
| /* Read the CTF section only if there is no DWARF info. */ | |
| if (!has_dwarf2 && ei.ctfsect) | |
| { | |
| elfctf_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 */ | |
| 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 */ | |
| }; | |
| /* 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 | |
| _initialize_elfread () | |
| { | |
| add_symtab_fns (bfd_target_elf_flavour, &elf_sym_fns); | |
| gnu_ifunc_fns_p = &elf_gnu_ifunc_fns; | |
| } |