| /* Read ELF (Executable and Linking Format) object files for GDB. |
| |
| Copyright (C) 1991-2021 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; |
| } |
| |
| /* 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_symbol_type *) 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!!! */ |
| 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, |
| gdb::string_view (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, gdb::string_view (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 = 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) |
| 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 = 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 (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_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 (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_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 (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 |
| && ei->ctfsect == 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; |
| 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; |
| } |