/* ELF executable support for BFD. Copyright 1991, 1992, 1993, 1994 Free Software Foundation, Inc. Written by Fred Fish @ Cygnus Support, from information published in "UNIX System V Release 4, Programmers Guide: ANSI C and Programming Support Tools". Sufficient support for gdb. Rewritten by Mark Eichin @ Cygnus Support, from information published in "System V Application Binary Interface", chapters 4 and 5, as well as the various "Processor Supplement" documents derived from it. Added support for assembler and other object file utilities. Further work done by Ken Raeburn (Cygnus Support), Michael Meissner (Open Software Foundation), and Peter Hoogenboom (University of Utah) to finish and extend this. This file is part of BFD, the Binary File Descriptor library. 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 2 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, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ /* Problems and other issues to resolve. (1) BFD expects there to be some fixed number of "sections" in the object file. I.E. there is a "section_count" variable in the bfd structure which contains the number of sections. However, ELF supports multiple "views" of a file. In particular, with current implementations, executable files typically have two tables, a program header table and a section header table, both of which partition the executable. In ELF-speak, the "linking view" of the file uses the section header table to access "sections" within the file, and the "execution view" uses the program header table to access "segments" within the file. "Segments" typically may contain all the data from one or more "sections". Note that the section header table is optional in ELF executables, but it is this information that is most useful to gdb. If the section header table is missing, then gdb should probably try to make do with the program header table. (FIXME) (2) The code in this file is compiled twice, once in 32-bit mode and once in 64-bit mode. More of it should be made size-independent and moved into elf.c. (3) ELF section symbols are handled rather sloppily now. This should be cleaned up, and ELF section symbols reconciled with BFD section symbols. (4) We need a published spec for 64-bit ELF. We've got some stuff here that we're using for SPARC V9 64-bit chips, but don't assume that it's cast in stone. */ #include /* For strrchr and friends */ #include "bfd.h" #include "sysdep.h" #include "bfdlink.h" #include "libbfd.h" #include "libelf.h" /* Renaming structures, typedefs, macros and functions to be size-specific. */ #define Elf_External_Ehdr NAME(Elf,External_Ehdr) #define Elf_External_Sym NAME(Elf,External_Sym) #define Elf_External_Shdr NAME(Elf,External_Shdr) #define Elf_External_Phdr NAME(Elf,External_Phdr) #define Elf_External_Rel NAME(Elf,External_Rel) #define Elf_External_Rela NAME(Elf,External_Rela) #define Elf_External_Dyn NAME(Elf,External_Dyn) #define elf_core_file_failing_command NAME(bfd_elf,core_file_failing_command) #define elf_core_file_failing_signal NAME(bfd_elf,core_file_failing_signal) #define elf_core_file_matches_executable_p \ NAME(bfd_elf,core_file_matches_executable_p) #define elf_object_p NAME(bfd_elf,object_p) #define elf_core_file_p NAME(bfd_elf,core_file_p) #define elf_get_symtab_upper_bound NAME(bfd_elf,get_symtab_upper_bound) #define elf_get_dynamic_symtab_upper_bound \ NAME(bfd_elf,get_dynamic_symtab_upper_bound) #define elf_swap_reloc_in NAME(bfd_elf,swap_reloc_in) #define elf_swap_reloca_in NAME(bfd_elf,swap_reloca_in) #define elf_swap_reloc_out NAME(bfd_elf,swap_reloc_out) #define elf_swap_reloca_out NAME(bfd_elf,swap_reloca_out) #define elf_swap_symbol_in NAME(bfd_elf,swap_symbol_in) #define elf_swap_symbol_out NAME(bfd_elf,swap_symbol_out) #define elf_swap_dyn_in NAME(bfd_elf,swap_dyn_in) #define elf_swap_dyn_out NAME(bfd_elf,swap_dyn_out) #define elf_get_reloc_upper_bound NAME(bfd_elf,get_reloc_upper_bound) #define elf_canonicalize_reloc NAME(bfd_elf,canonicalize_reloc) #define elf_get_symtab NAME(bfd_elf,get_symtab) #define elf_canonicalize_dynamic_symtab \ NAME(bfd_elf,canonicalize_dynamic_symtab) #define elf_make_empty_symbol NAME(bfd_elf,make_empty_symbol) #define elf_get_symbol_info NAME(bfd_elf,get_symbol_info) #define elf_get_lineno NAME(bfd_elf,get_lineno) #define elf_set_arch_mach NAME(bfd_elf,set_arch_mach) #define elf_find_nearest_line NAME(bfd_elf,find_nearest_line) #define elf_sizeof_headers NAME(bfd_elf,sizeof_headers) #define elf_set_section_contents NAME(bfd_elf,set_section_contents) #define elf_no_info_to_howto NAME(bfd_elf,no_info_to_howto) #define elf_no_info_to_howto_rel NAME(bfd_elf,no_info_to_howto_rel) #define elf_new_section_hook NAME(bfd_elf,new_section_hook) #define write_relocs NAME(bfd_elf,_write_relocs) #define elf_find_section NAME(bfd_elf,find_section) #define elf_bfd_link_add_symbols NAME(bfd_elf,bfd_link_add_symbols) #define elf_add_dynamic_entry NAME(bfd_elf,add_dynamic_entry) #define elf_link_create_dynamic_sections \ NAME(bfd_elf,link_create_dynamic_sections) #define elf_link_record_dynamic_symbol \ NAME(bfd_elf,link_record_dynamic_symbol) #define elf_bfd_final_link NAME(bfd_elf,bfd_final_link) #if ARCH_SIZE == 64 #define ELF_R_INFO(X,Y) ELF64_R_INFO(X,Y) #define ELF_R_SYM(X) ELF64_R_SYM(X) #define ELF_R_TYPE(X) ELF64_R_TYPE(X) #define ELFCLASS ELFCLASS64 #define FILE_ALIGN 8 #define LOG_FILE_ALIGN 3 #endif #if ARCH_SIZE == 32 #define ELF_R_INFO(X,Y) ELF32_R_INFO(X,Y) #define ELF_R_SYM(X) ELF32_R_SYM(X) #define ELF_R_TYPE(X) ELF32_R_TYPE(X) #define ELFCLASS ELFCLASS32 #define FILE_ALIGN 4 #define LOG_FILE_ALIGN 2 #endif /* Forward declarations of static functions */ static unsigned long bfd_add_to_strtab PARAMS ((bfd *, struct strtab *, const char *)); static asection *section_from_elf_index PARAMS ((bfd *, unsigned int)); static int elf_section_from_bfd_section PARAMS ((bfd *, struct sec *)); static long elf_slurp_symbol_table PARAMS ((bfd *, asymbol **, boolean)); static boolean elf_slurp_reloc_table PARAMS ((bfd *, asection *, asymbol **)); static int elf_symbol_from_bfd_symbol PARAMS ((bfd *, struct symbol_cache_entry **)); static boolean elf_compute_section_file_positions PARAMS ((bfd *, struct bfd_link_info *)); static boolean prep_headers PARAMS ((bfd *)); static void elf_fake_sections PARAMS ((bfd *, asection *, PTR)); static boolean assign_section_numbers PARAMS ((bfd *)); static file_ptr align_file_position PARAMS ((file_ptr)); static file_ptr assign_file_position_for_section PARAMS ((Elf_Internal_Shdr *, file_ptr, boolean)); static boolean assign_file_positions_except_relocs PARAMS ((bfd *, boolean)); static void assign_file_positions_for_relocs PARAMS ((bfd *)); static bfd_size_type get_program_header_size PARAMS ((bfd *)); static file_ptr map_program_segments PARAMS ((bfd *, file_ptr, Elf_Internal_Shdr *, bfd_size_type)); static boolean elf_map_symbols PARAMS ((bfd *)); static boolean swap_out_syms PARAMS ((bfd *)); static boolean bfd_section_from_shdr PARAMS ((bfd *, unsigned int shindex)); #ifdef DEBUG static void elf_debug_section PARAMS ((char *, int, Elf_Internal_Shdr *)); static void elf_debug_file PARAMS ((Elf_Internal_Ehdr *)); #endif #define elf_string_from_elf_strtab(abfd,strindex) \ elf_string_from_elf_section(abfd,elf_elfheader(abfd)->e_shstrndx,strindex) /* Structure swapping routines */ /* Should perhaps use put_offset, put_word, etc. For now, the two versions can be handled by explicitly specifying 32 bits or "the long type". */ #if ARCH_SIZE == 64 #define put_word bfd_h_put_64 #define get_word bfd_h_get_64 #endif #if ARCH_SIZE == 32 #define put_word bfd_h_put_32 #define get_word bfd_h_get_32 #endif /* Translate an ELF symbol in external format into an ELF symbol in internal format. */ void elf_swap_symbol_in (abfd, src, dst) bfd *abfd; Elf_External_Sym *src; Elf_Internal_Sym *dst; { dst->st_name = bfd_h_get_32 (abfd, (bfd_byte *) src->st_name); dst->st_value = get_word (abfd, (bfd_byte *) src->st_value); dst->st_size = get_word (abfd, (bfd_byte *) src->st_size); dst->st_info = bfd_h_get_8 (abfd, (bfd_byte *) src->st_info); dst->st_other = bfd_h_get_8 (abfd, (bfd_byte *) src->st_other); dst->st_shndx = bfd_h_get_16 (abfd, (bfd_byte *) src->st_shndx); } /* Translate an ELF symbol in internal format into an ELF symbol in external format. */ void elf_swap_symbol_out (abfd, src, dst) bfd *abfd; Elf_Internal_Sym *src; Elf_External_Sym *dst; { bfd_h_put_32 (abfd, src->st_name, dst->st_name); put_word (abfd, src->st_value, dst->st_value); put_word (abfd, src->st_size, dst->st_size); bfd_h_put_8 (abfd, src->st_info, dst->st_info); bfd_h_put_8 (abfd, src->st_other, dst->st_other); bfd_h_put_16 (abfd, src->st_shndx, dst->st_shndx); } /* Translate an ELF file header in external format into an ELF file header in internal format. */ static void elf_swap_ehdr_in (abfd, src, dst) bfd *abfd; Elf_External_Ehdr *src; Elf_Internal_Ehdr *dst; { memcpy (dst->e_ident, src->e_ident, EI_NIDENT); dst->e_type = bfd_h_get_16 (abfd, (bfd_byte *) src->e_type); dst->e_machine = bfd_h_get_16 (abfd, (bfd_byte *) src->e_machine); dst->e_version = bfd_h_get_32 (abfd, (bfd_byte *) src->e_version); dst->e_entry = get_word (abfd, (bfd_byte *) src->e_entry); dst->e_phoff = get_word (abfd, (bfd_byte *) src->e_phoff); dst->e_shoff = get_word (abfd, (bfd_byte *) src->e_shoff); dst->e_flags = bfd_h_get_32 (abfd, (bfd_byte *) src->e_flags); dst->e_ehsize = bfd_h_get_16 (abfd, (bfd_byte *) src->e_ehsize); dst->e_phentsize = bfd_h_get_16 (abfd, (bfd_byte *) src->e_phentsize); dst->e_phnum = bfd_h_get_16 (abfd, (bfd_byte *) src->e_phnum); dst->e_shentsize = bfd_h_get_16 (abfd, (bfd_byte *) src->e_shentsize); dst->e_shnum = bfd_h_get_16 (abfd, (bfd_byte *) src->e_shnum); dst->e_shstrndx = bfd_h_get_16 (abfd, (bfd_byte *) src->e_shstrndx); } /* Translate an ELF file header in internal format into an ELF file header in external format. */ static void elf_swap_ehdr_out (abfd, src, dst) bfd *abfd; Elf_Internal_Ehdr *src; Elf_External_Ehdr *dst; { memcpy (dst->e_ident, src->e_ident, EI_NIDENT); /* note that all elements of dst are *arrays of unsigned char* already... */ bfd_h_put_16 (abfd, src->e_type, dst->e_type); bfd_h_put_16 (abfd, src->e_machine, dst->e_machine); bfd_h_put_32 (abfd, src->e_version, dst->e_version); put_word (abfd, src->e_entry, dst->e_entry); put_word (abfd, src->e_phoff, dst->e_phoff); put_word (abfd, src->e_shoff, dst->e_shoff); bfd_h_put_32 (abfd, src->e_flags, dst->e_flags); bfd_h_put_16 (abfd, src->e_ehsize, dst->e_ehsize); bfd_h_put_16 (abfd, src->e_phentsize, dst->e_phentsize); bfd_h_put_16 (abfd, src->e_phnum, dst->e_phnum); bfd_h_put_16 (abfd, src->e_shentsize, dst->e_shentsize); bfd_h_put_16 (abfd, src->e_shnum, dst->e_shnum); bfd_h_put_16 (abfd, src->e_shstrndx, dst->e_shstrndx); } /* Translate an ELF section header table entry in external format into an ELF section header table entry in internal format. */ static void elf_swap_shdr_in (abfd, src, dst) bfd *abfd; Elf_External_Shdr *src; Elf_Internal_Shdr *dst; { dst->sh_name = bfd_h_get_32 (abfd, (bfd_byte *) src->sh_name); dst->sh_type = bfd_h_get_32 (abfd, (bfd_byte *) src->sh_type); dst->sh_flags = get_word (abfd, (bfd_byte *) src->sh_flags); dst->sh_addr = get_word (abfd, (bfd_byte *) src->sh_addr); dst->sh_offset = get_word (abfd, (bfd_byte *) src->sh_offset); dst->sh_size = get_word (abfd, (bfd_byte *) src->sh_size); dst->sh_link = bfd_h_get_32 (abfd, (bfd_byte *) src->sh_link); dst->sh_info = bfd_h_get_32 (abfd, (bfd_byte *) src->sh_info); dst->sh_addralign = get_word (abfd, (bfd_byte *) src->sh_addralign); dst->sh_entsize = get_word (abfd, (bfd_byte *) src->sh_entsize); /* we haven't done any processing on it yet, so... */ dst->rawdata = (void *) 0; } /* Translate an ELF section header table entry in internal format into an ELF section header table entry in external format. */ static void elf_swap_shdr_out (abfd, src, dst) bfd *abfd; Elf_Internal_Shdr *src; Elf_External_Shdr *dst; { /* note that all elements of dst are *arrays of unsigned char* already... */ bfd_h_put_32 (abfd, src->sh_name, dst->sh_name); bfd_h_put_32 (abfd, src->sh_type, dst->sh_type); put_word (abfd, src->sh_flags, dst->sh_flags); put_word (abfd, src->sh_addr, dst->sh_addr); put_word (abfd, src->sh_offset, dst->sh_offset); put_word (abfd, src->sh_size, dst->sh_size); bfd_h_put_32 (abfd, src->sh_link, dst->sh_link); bfd_h_put_32 (abfd, src->sh_info, dst->sh_info); put_word (abfd, src->sh_addralign, dst->sh_addralign); put_word (abfd, src->sh_entsize, dst->sh_entsize); } /* Translate an ELF program header table entry in external format into an ELF program header table entry in internal format. */ static void elf_swap_phdr_in (abfd, src, dst) bfd *abfd; Elf_External_Phdr *src; Elf_Internal_Phdr *dst; { dst->p_type = bfd_h_get_32 (abfd, (bfd_byte *) src->p_type); dst->p_flags = bfd_h_get_32 (abfd, (bfd_byte *) src->p_flags); dst->p_offset = get_word (abfd, (bfd_byte *) src->p_offset); dst->p_vaddr = get_word (abfd, (bfd_byte *) src->p_vaddr); dst->p_paddr = get_word (abfd, (bfd_byte *) src->p_paddr); dst->p_filesz = get_word (abfd, (bfd_byte *) src->p_filesz); dst->p_memsz = get_word (abfd, (bfd_byte *) src->p_memsz); dst->p_align = get_word (abfd, (bfd_byte *) src->p_align); } static void elf_swap_phdr_out (abfd, src, dst) bfd *abfd; Elf_Internal_Phdr *src; Elf_External_Phdr *dst; { /* note that all elements of dst are *arrays of unsigned char* already... */ bfd_h_put_32 (abfd, src->p_type, dst->p_type); put_word (abfd, src->p_offset, dst->p_offset); put_word (abfd, src->p_vaddr, dst->p_vaddr); put_word (abfd, src->p_paddr, dst->p_paddr); put_word (abfd, src->p_filesz, dst->p_filesz); put_word (abfd, src->p_memsz, dst->p_memsz); bfd_h_put_32 (abfd, src->p_flags, dst->p_flags); put_word (abfd, src->p_align, dst->p_align); } /* Translate an ELF reloc from external format to internal format. */ INLINE void elf_swap_reloc_in (abfd, src, dst) bfd *abfd; Elf_External_Rel *src; Elf_Internal_Rel *dst; { dst->r_offset = get_word (abfd, (bfd_byte *) src->r_offset); dst->r_info = get_word (abfd, (bfd_byte *) src->r_info); } INLINE void elf_swap_reloca_in (abfd, src, dst) bfd *abfd; Elf_External_Rela *src; Elf_Internal_Rela *dst; { dst->r_offset = get_word (abfd, (bfd_byte *) src->r_offset); dst->r_info = get_word (abfd, (bfd_byte *) src->r_info); dst->r_addend = get_word (abfd, (bfd_byte *) src->r_addend); } /* Translate an ELF reloc from internal format to external format. */ INLINE void elf_swap_reloc_out (abfd, src, dst) bfd *abfd; Elf_Internal_Rel *src; Elf_External_Rel *dst; { put_word (abfd, src->r_offset, dst->r_offset); put_word (abfd, src->r_info, dst->r_info); } INLINE void elf_swap_reloca_out (abfd, src, dst) bfd *abfd; Elf_Internal_Rela *src; Elf_External_Rela *dst; { put_word (abfd, src->r_offset, dst->r_offset); put_word (abfd, src->r_info, dst->r_info); put_word (abfd, src->r_addend, dst->r_addend); } INLINE void elf_swap_dyn_in (abfd, src, dst) bfd *abfd; const Elf_External_Dyn *src; Elf_Internal_Dyn *dst; { dst->d_tag = get_word (abfd, src->d_tag); dst->d_un.d_val = get_word (abfd, src->d_un.d_val); } INLINE void elf_swap_dyn_out (abfd, src, dst) bfd *abfd; const Elf_Internal_Dyn *src; Elf_External_Dyn *dst; { put_word (abfd, src->d_tag, dst->d_tag); put_word (abfd, src->d_un.d_val, dst->d_un.d_val); } /* String table creation/manipulation routines */ static struct strtab * bfd_new_strtab (abfd) bfd *abfd; { struct strtab *ss; ss = (struct strtab *) malloc (sizeof (struct strtab)); if (!ss) { bfd_set_error (bfd_error_no_memory); return NULL; } ss->tab = malloc (1); if (!ss->tab) { bfd_set_error (bfd_error_no_memory); return NULL; } *ss->tab = 0; ss->nentries = 0; ss->length = 1; return ss; } static unsigned long bfd_add_to_strtab (abfd, ss, str) bfd *abfd; struct strtab *ss; const char *str; { /* should search first, but for now: */ /* include the trailing NUL */ int ln = strlen (str) + 1; /* FIXME: This is slow. Also, we could combine this with the a.out string table building and use a hash table, although it might not be worth it since ELF symbols don't include debugging information and thus have much less overlap. */ ss->tab = realloc (ss->tab, ss->length + ln); if (ss->tab == NULL) { bfd_set_error (bfd_error_no_memory); return (unsigned long) -1; } strcpy (ss->tab + ss->length, str); ss->nentries++; ss->length += ln; return ss->length - ln; } static int bfd_add_2_to_strtab (abfd, ss, str, str2) bfd *abfd; struct strtab *ss; char *str; CONST char *str2; { /* should search first, but for now: */ /* include the trailing NUL */ int ln = strlen (str) + strlen (str2) + 1; /* should this be using obstacks? */ if (ss->length) ss->tab = realloc (ss->tab, ss->length + ln); else ss->tab = malloc (ln); BFD_ASSERT (ss->tab != 0); /* FIXME */ strcpy (ss->tab + ss->length, str); strcpy (ss->tab + ss->length + strlen (str), str2); ss->nentries++; ss->length += ln; return ss->length - ln; } /* ELF .o/exec file reading */ /* Create a new bfd section from an ELF section header. */ static boolean bfd_section_from_shdr (abfd, shindex) bfd *abfd; unsigned int shindex; { Elf_Internal_Shdr *hdr = elf_elfsections (abfd)[shindex]; Elf_Internal_Ehdr *ehdr = elf_elfheader (abfd); char *name; name = elf_string_from_elf_strtab (abfd, hdr->sh_name); switch (hdr->sh_type) { case SHT_NULL: /* Inactive section. Throw it away. */ return true; case SHT_PROGBITS: /* Normal section with contents. */ case SHT_DYNAMIC: /* Dynamic linking information. */ case SHT_NOBITS: /* .bss section. */ case SHT_HASH: /* .hash section. */ return _bfd_elf_make_section_from_shdr (abfd, hdr, name); case SHT_SYMTAB: /* A symbol table */ if (elf_onesymtab (abfd) == shindex) return true; BFD_ASSERT (hdr->sh_entsize == sizeof (Elf_External_Sym)); BFD_ASSERT (elf_onesymtab (abfd) == 0); elf_onesymtab (abfd) = shindex; elf_tdata (abfd)->symtab_hdr = *hdr; elf_elfsections (abfd)[shindex] = &elf_tdata (abfd)->symtab_hdr; abfd->flags |= HAS_SYMS; /* Sometimes a shared object will map in the symbol table. If SHF_ALLOC is set, and this is a shared object, then we also treat this section as a BFD section. We can not base the decision purely on SHF_ALLOC, because that flag is sometimes set in a relocateable object file, which would confuse the linker. */ if ((hdr->sh_flags & SHF_ALLOC) != 0 && (abfd->flags & DYNAMIC) != 0 && ! _bfd_elf_make_section_from_shdr (abfd, hdr, name)) return false; return true; case SHT_DYNSYM: /* A dynamic symbol table */ if (elf_dynsymtab (abfd) == shindex) return true; BFD_ASSERT (hdr->sh_entsize == sizeof (Elf_External_Sym)); BFD_ASSERT (elf_dynsymtab (abfd) == 0); elf_dynsymtab (abfd) = shindex; elf_tdata (abfd)->dynsymtab_hdr = *hdr; elf_elfsections (abfd)[shindex] = &elf_tdata (abfd)->dynsymtab_hdr; abfd->flags |= HAS_SYMS; /* Besides being a symbol table, we also treat this as a regular section, so that objcopy can handle it. */ return _bfd_elf_make_section_from_shdr (abfd, hdr, name); case SHT_STRTAB: /* A string table */ if (hdr->rawdata != NULL) return true; if (ehdr->e_shstrndx == shindex) { elf_tdata (abfd)->shstrtab_hdr = *hdr; elf_elfsections (abfd)[shindex] = &elf_tdata (abfd)->shstrtab_hdr; hdr->rawdata = (PTR) & elf_tdata (abfd)->shstrtab_hdr; return true; } { unsigned int i; for (i = 1; i < ehdr->e_shnum; i++) { Elf_Internal_Shdr *hdr2 = elf_elfsections (abfd)[i]; if (hdr2->sh_link == shindex) { if (! bfd_section_from_shdr (abfd, i)) return false; if (elf_onesymtab (abfd) == i) { elf_tdata (abfd)->strtab_hdr = *hdr; elf_elfsections (abfd)[shindex] = &elf_tdata (abfd)->strtab_hdr; return true; } if (elf_dynsymtab (abfd) == i) { elf_tdata (abfd)->dynstrtab_hdr = *hdr; elf_elfsections (abfd)[shindex] = &elf_tdata (abfd)->dynstrtab_hdr; /* We also treat this as a regular section, so that objcopy can handle it. */ break; } #if 0 /* Not handling other string tables specially right now. */ hdr2 = elf_elfsections (abfd)[i]; /* in case it moved */ /* We have a strtab for some random other section. */ newsect = (asection *) hdr2->rawdata; if (!newsect) break; hdr->rawdata = (PTR) newsect; hdr2 = &elf_section_data (newsect)->str_hdr; *hdr2 = *hdr; elf_elfsections (abfd)[shindex] = hdr2; #endif } } } return _bfd_elf_make_section_from_shdr (abfd, hdr, name); case SHT_REL: case SHT_RELA: /* *These* do a lot of work -- but build no sections! */ { asection *target_sect; Elf_Internal_Shdr *hdr2; int use_rela_p = get_elf_backend_data (abfd)->use_rela_p; /* Get the symbol table. */ if (! bfd_section_from_shdr (abfd, hdr->sh_link)) return false; /* If this reloc section does not use the main symbol table we don't treat it as a reloc section. BFD can't adequately represent such a section, so at least for now, we don't try. We just present it as a normal section. */ if (hdr->sh_link != elf_onesymtab (abfd)) return _bfd_elf_make_section_from_shdr (abfd, hdr, name); /* Don't allow REL relocations on a machine that uses RELA and vice versa. */ /* @@ Actually, the generic ABI does suggest that both might be used in one file. But the four ABI Processor Supplements I have access to right now all specify that only one is used on each of those architectures. It's conceivable that, e.g., a bunch of absolute 32-bit relocs might be more compact in REL form even on a RELA machine... */ BFD_ASSERT (use_rela_p ? (hdr->sh_type == SHT_RELA && hdr->sh_entsize == sizeof (Elf_External_Rela)) : (hdr->sh_type == SHT_REL && hdr->sh_entsize == sizeof (Elf_External_Rel))); if (! bfd_section_from_shdr (abfd, hdr->sh_info)) return false; target_sect = section_from_elf_index (abfd, hdr->sh_info); if (target_sect == NULL || elf_section_data (target_sect) == NULL) return false; hdr2 = &elf_section_data (target_sect)->rel_hdr; *hdr2 = *hdr; elf_elfsections (abfd)[shindex] = hdr2; target_sect->reloc_count = hdr->sh_size / hdr->sh_entsize; target_sect->flags |= SEC_RELOC; target_sect->relocation = NULL; target_sect->rel_filepos = hdr->sh_offset; abfd->flags |= HAS_RELOC; return true; } break; case SHT_NOTE: #if 0 fprintf (stderr, "Note Sections not yet supported.\n"); BFD_FAIL (); #endif break; case SHT_SHLIB: #if 0 fprintf (stderr, "SHLIB Sections not supported (and non conforming.)\n"); #endif return true; default: /* Check for any processor-specific section types. */ { struct elf_backend_data *bed = get_elf_backend_data (abfd); if (bed->elf_backend_section_from_shdr) (*bed->elf_backend_section_from_shdr) (abfd, hdr, name); } break; } return true; } boolean elf_new_section_hook (abfd, sec) bfd *abfd ; asection *sec; { struct bfd_elf_section_data *sdata; sdata = (struct bfd_elf_section_data *) bfd_alloc (abfd, sizeof (*sdata)); if (!sdata) { bfd_set_error (bfd_error_no_memory); return false; } sec->used_by_bfd = (PTR) sdata; memset (sdata, 0, sizeof (*sdata)); return true; } /* Create a new bfd section from an ELF program header. Since program segments have no names, we generate a synthetic name of the form segment, where NUM is generally the index in the program header table. For segments that are split (see below) we generate the names segmenta and segmentb. Note that some program segments may have a file size that is different than (less than) the memory size. All this means is that at execution the system must allocate the amount of memory specified by the memory size, but only initialize it with the first "file size" bytes read from the file. This would occur for example, with program segments consisting of combined data+bss. To handle the above situation, this routine generates TWO bfd sections for the single program segment. The first has the length specified by the file size of the segment, and the second has the length specified by the difference between the two sizes. In effect, the segment is split into it's initialized and uninitialized parts. */ static boolean bfd_section_from_phdr (abfd, hdr, index) bfd *abfd; Elf_Internal_Phdr *hdr; int index; { asection *newsect; char *name; char namebuf[64]; int split; split = ((hdr->p_memsz > 0) && (hdr->p_filesz > 0) && (hdr->p_memsz > hdr->p_filesz)); sprintf (namebuf, split ? "segment%da" : "segment%d", index); name = bfd_alloc (abfd, strlen (namebuf) + 1); if (!name) { bfd_set_error (bfd_error_no_memory); return false; } strcpy (name, namebuf); newsect = bfd_make_section (abfd, name); if (newsect == NULL) return false; newsect->vma = hdr->p_vaddr; newsect->_raw_size = hdr->p_filesz; newsect->filepos = hdr->p_offset; newsect->flags |= SEC_HAS_CONTENTS; if (hdr->p_type == PT_LOAD) { newsect->flags |= SEC_ALLOC; newsect->flags |= SEC_LOAD; if (hdr->p_flags & PF_X) { /* FIXME: all we known is that it has execute PERMISSION, may be data. */ newsect->flags |= SEC_CODE; } } if (!(hdr->p_flags & PF_W)) { newsect->flags |= SEC_READONLY; } if (split) { sprintf (namebuf, "segment%db", index); name = bfd_alloc (abfd, strlen (namebuf) + 1); if (!name) { bfd_set_error (bfd_error_no_memory); return false; } strcpy (name, namebuf); newsect = bfd_make_section (abfd, name); if (newsect == NULL) return false; newsect->vma = hdr->p_vaddr + hdr->p_filesz; newsect->_raw_size = hdr->p_memsz - hdr->p_filesz; if (hdr->p_type == PT_LOAD) { newsect->flags |= SEC_ALLOC; if (hdr->p_flags & PF_X) newsect->flags |= SEC_CODE; } if (!(hdr->p_flags & PF_W)) newsect->flags |= SEC_READONLY; } return true; } /* Begin processing a given object. First we validate the file by reading in the ELF header and checking the magic number. */ static INLINE boolean elf_file_p (x_ehdrp) Elf_External_Ehdr *x_ehdrp; { return ((x_ehdrp->e_ident[EI_MAG0] == ELFMAG0) && (x_ehdrp->e_ident[EI_MAG1] == ELFMAG1) && (x_ehdrp->e_ident[EI_MAG2] == ELFMAG2) && (x_ehdrp->e_ident[EI_MAG3] == ELFMAG3)); } /* Check to see if the file associated with ABFD matches the target vector that ABFD points to. Note that we may be called several times with the same ABFD, but different target vectors, most of which will not match. We have to avoid leaving any side effects in ABFD, or any data it points to (like tdata), if the file does not match the target vector. */ const bfd_target * elf_object_p (abfd) bfd *abfd; { Elf_External_Ehdr x_ehdr; /* Elf file header, external form */ Elf_Internal_Ehdr *i_ehdrp; /* Elf file header, internal form */ Elf_External_Shdr x_shdr; /* Section header table entry, external form */ Elf_Internal_Shdr *i_shdrp = NULL; /* Section header table, internal form */ unsigned int shindex; char *shstrtab; /* Internal copy of section header stringtab */ struct elf_backend_data *ebd; struct elf_obj_tdata *preserved_tdata = elf_tdata (abfd); struct elf_obj_tdata *new_tdata = NULL; /* Read in the ELF header in external format. */ if (bfd_read ((PTR) & x_ehdr, sizeof (x_ehdr), 1, abfd) != sizeof (x_ehdr)) { if (bfd_get_error () != bfd_error_system_call) goto got_wrong_format_error; else goto got_no_match; } /* Now check to see if we have a valid ELF file, and one that BFD can make use of. The magic number must match, the address size ('class') and byte-swapping must match our XVEC entry, and it must have a section header table (FIXME: See comments re sections at top of this file). */ if ((elf_file_p (&x_ehdr) == false) || (x_ehdr.e_ident[EI_VERSION] != EV_CURRENT) || (x_ehdr.e_ident[EI_CLASS] != ELFCLASS)) goto got_wrong_format_error; /* Check that file's byte order matches xvec's */ switch (x_ehdr.e_ident[EI_DATA]) { case ELFDATA2MSB: /* Big-endian */ if (!abfd->xvec->header_byteorder_big_p) goto got_wrong_format_error; break; case ELFDATA2LSB: /* Little-endian */ if (abfd->xvec->header_byteorder_big_p) goto got_wrong_format_error; break; case ELFDATANONE: /* No data encoding specified */ default: /* Unknown data encoding specified */ goto got_wrong_format_error; } /* Allocate an instance of the elf_obj_tdata structure and hook it up to the tdata pointer in the bfd. */ new_tdata = ((struct elf_obj_tdata *) bfd_zalloc (abfd, sizeof (struct elf_obj_tdata))); if (new_tdata == NULL) goto got_no_memory_error; elf_tdata (abfd) = new_tdata; /* Now that we know the byte order, swap in the rest of the header */ i_ehdrp = elf_elfheader (abfd); elf_swap_ehdr_in (abfd, &x_ehdr, i_ehdrp); #if DEBUG & 1 elf_debug_file (i_ehdrp); #endif /* If there is no section header table, we're hosed. */ if (i_ehdrp->e_shoff == 0) goto got_wrong_format_error; /* As a simple sanity check, verify that the what BFD thinks is the size of each section header table entry actually matches the size recorded in the file. */ if (i_ehdrp->e_shentsize != sizeof (x_shdr)) goto got_wrong_format_error; ebd = get_elf_backend_data (abfd); /* Check that the ELF e_machine field matches what this particular BFD format expects. */ if (ebd->elf_machine_code != i_ehdrp->e_machine) { const bfd_target * const *target_ptr; if (ebd->elf_machine_code != EM_NONE) goto got_wrong_format_error; /* This is the generic ELF target. Let it match any ELF target for which we do not have a specific backend. */ for (target_ptr = bfd_target_vector; *target_ptr != NULL; target_ptr++) { struct elf_backend_data *back; if ((*target_ptr)->flavour != bfd_target_elf_flavour) continue; back = (struct elf_backend_data *) (*target_ptr)->backend_data; if (back->elf_machine_code == i_ehdrp->e_machine) { /* target_ptr is an ELF backend which matches this object file, so reject the generic ELF target. */ goto got_wrong_format_error; } } } if (i_ehdrp->e_type == ET_EXEC) abfd->flags |= EXEC_P; else if (i_ehdrp->e_type == ET_DYN) abfd->flags |= DYNAMIC; if (i_ehdrp->e_phnum > 0) abfd->flags |= D_PAGED; if (! bfd_default_set_arch_mach (abfd, ebd->arch, 0)) goto got_no_match; /* Remember the entry point specified in the ELF file header. */ bfd_get_start_address (abfd) = i_ehdrp->e_entry; /* Allocate space for a copy of the section header table in internal form, seek to the section header table in the file, read it in, and convert it to internal form. */ i_shdrp = ((Elf_Internal_Shdr *) bfd_alloc (abfd, sizeof (*i_shdrp) * i_ehdrp->e_shnum)); elf_elfsections (abfd) = ((Elf_Internal_Shdr **) bfd_alloc (abfd, sizeof (i_shdrp) * i_ehdrp->e_shnum)); if (!i_shdrp || !elf_elfsections (abfd)) goto got_no_memory_error; if (bfd_seek (abfd, i_ehdrp->e_shoff, SEEK_SET) != 0) goto got_no_match; for (shindex = 0; shindex < i_ehdrp->e_shnum; shindex++) { if (bfd_read ((PTR) & x_shdr, sizeof x_shdr, 1, abfd) != sizeof (x_shdr)) goto got_no_match; elf_swap_shdr_in (abfd, &x_shdr, i_shdrp + shindex); elf_elfsections (abfd)[shindex] = i_shdrp + shindex; } if (i_ehdrp->e_shstrndx) { if (! bfd_section_from_shdr (abfd, i_ehdrp->e_shstrndx)) goto got_no_match; } /* Read in the string table containing the names of the sections. We will need the base pointer to this table later. */ /* We read this inline now, so that we don't have to go through bfd_section_from_shdr with it (since this particular strtab is used to find all of the ELF section names.) */ shstrtab = elf_get_str_section (abfd, i_ehdrp->e_shstrndx); if (!shstrtab) goto got_no_match; /* Once all of the section headers have been read and converted, we can start processing them. Note that the first section header is a dummy placeholder entry, so we ignore it. */ for (shindex = 1; shindex < i_ehdrp->e_shnum; shindex++) { if (! bfd_section_from_shdr (abfd, shindex)) goto got_no_match; } /* Let the backend double check the format and override global information. */ if (ebd->elf_backend_object_p) { if ((*ebd->elf_backend_object_p) (abfd) == false) goto got_wrong_format_error; } return (abfd->xvec); got_wrong_format_error: bfd_set_error (bfd_error_wrong_format); goto got_no_match; got_no_memory_error: bfd_set_error (bfd_error_no_memory); goto got_no_match; got_no_match: if (new_tdata != NULL && new_tdata->elf_sect_ptr != NULL) bfd_release (abfd, new_tdata->elf_sect_ptr); if (i_shdrp != NULL) bfd_release (abfd, i_shdrp); if (new_tdata != NULL) bfd_release (abfd, new_tdata); elf_tdata (abfd) = preserved_tdata; return (NULL); } /* ELF .o/exec file writing */ /* Takes a bfd and a symbol, returns a pointer to the elf specific area of the symbol if there is one. */ static INLINE elf_symbol_type * elf_symbol_from (ignore_abfd, symbol) bfd *ignore_abfd; asymbol *symbol; { if (symbol->the_bfd->xvec->flavour != bfd_target_elf_flavour) return 0; if (symbol->the_bfd->tdata.elf_obj_data == (struct elf_obj_tdata *) NULL) return 0; return (elf_symbol_type *) symbol; } void write_relocs (abfd, sec, xxx) bfd *abfd; asection *sec; PTR xxx; { Elf_Internal_Shdr *rela_hdr; Elf_External_Rela *outbound_relocas; Elf_External_Rel *outbound_relocs; int idx; int use_rela_p = get_elf_backend_data (abfd)->use_rela_p; asymbol *last_sym = 0; int last_sym_idx = 9999999; /* should always be written before use */ if ((sec->flags & SEC_RELOC) == 0) return; /* The linker backend writes the relocs out itself, and sets the reloc_count field to zero to inhibit writing them here. Also, sometimes the SEC_RELOC flag gets set even when there aren't any relocs. */ if (sec->reloc_count == 0) return; rela_hdr = &elf_section_data (sec)->rel_hdr; rela_hdr->sh_size = rela_hdr->sh_entsize * sec->reloc_count; rela_hdr->contents = (void *) bfd_alloc (abfd, rela_hdr->sh_size); if (!rela_hdr->contents) { bfd_set_error (bfd_error_no_memory); abort (); /* FIXME */ } /* orelocation has the data, reloc_count has the count... */ if (use_rela_p) { outbound_relocas = (Elf_External_Rela *) rela_hdr->contents; for (idx = 0; idx < sec->reloc_count; idx++) { Elf_Internal_Rela dst_rela; Elf_External_Rela *src_rela; arelent *ptr; asymbol *sym; int n; ptr = sec->orelocation[idx]; src_rela = outbound_relocas + idx; if (!(abfd->flags & EXEC_P)) dst_rela.r_offset = ptr->address - sec->vma; else dst_rela.r_offset = ptr->address; sym = *ptr->sym_ptr_ptr; if (sym == last_sym) n = last_sym_idx; else { last_sym = sym; last_sym_idx = n = elf_symbol_from_bfd_symbol (abfd, &sym); } dst_rela.r_info = ELF_R_INFO (n, ptr->howto->type); dst_rela.r_addend = ptr->addend; elf_swap_reloca_out (abfd, &dst_rela, src_rela); } } else /* REL relocations */ { outbound_relocs = (Elf_External_Rel *) rela_hdr->contents; for (idx = 0; idx < sec->reloc_count; idx++) { Elf_Internal_Rel dst_rel; Elf_External_Rel *src_rel; arelent *ptr; int n; asymbol *sym; ptr = sec->orelocation[idx]; sym = *ptr->sym_ptr_ptr; src_rel = outbound_relocs + idx; if (!(abfd->flags & EXEC_P)) dst_rel.r_offset = ptr->address - sec->vma; else dst_rel.r_offset = ptr->address; if (sym == last_sym) n = last_sym_idx; else { last_sym = sym; last_sym_idx = n = elf_symbol_from_bfd_symbol (abfd, &sym); } dst_rel.r_info = ELF_R_INFO (n, ptr->howto->type); elf_swap_reloc_out (abfd, &dst_rel, src_rel); } } } /* Set up an ELF internal section header for a section. */ /*ARGSUSED*/ static void elf_fake_sections (abfd, asect, ignore) bfd *abfd; asection *asect; PTR ignore; { Elf_Internal_Shdr *this_hdr; this_hdr = &elf_section_data (asect)->this_hdr; this_hdr->sh_name = bfd_add_to_strtab (abfd, elf_shstrtab (abfd), asect->name); if (this_hdr->sh_name == (unsigned long) -1) abort (); /* FIXME */ this_hdr->sh_flags = 0; if ((asect->flags & SEC_ALLOC) != 0) this_hdr->sh_addr = asect->vma; else this_hdr->sh_addr = 0; this_hdr->sh_offset = 0; this_hdr->sh_size = asect->_raw_size; this_hdr->sh_link = 0; this_hdr->sh_info = 0; this_hdr->sh_addralign = 1 << asect->alignment_power; this_hdr->sh_entsize = 0; this_hdr->rawdata = (PTR) asect; this_hdr->contents = NULL; this_hdr->size = 0; /* FIXME: This should not be based on section names. */ if (strcmp (asect->name, ".dynstr") == 0) this_hdr->sh_type = SHT_STRTAB; else if (strcmp (asect->name, ".hash") == 0) { this_hdr->sh_type = SHT_HASH; this_hdr->sh_entsize = ARCH_SIZE / 8; } else if (strcmp (asect->name, ".dynsym") == 0) { this_hdr->sh_type = SHT_DYNSYM; this_hdr->sh_entsize = sizeof (Elf_External_Sym); } else if (strcmp (asect->name, ".dynamic") == 0) { this_hdr->sh_type = SHT_DYNAMIC; this_hdr->sh_entsize = sizeof (Elf_External_Dyn); } else if (strncmp (asect->name, ".rela", 5) == 0 && get_elf_backend_data (abfd)->use_rela_p) { this_hdr->sh_type = SHT_RELA; this_hdr->sh_entsize = sizeof (Elf_External_Rela); } else if (strncmp (asect->name, ".rel", 4) == 0 && ! get_elf_backend_data (abfd)->use_rela_p) { this_hdr->sh_type = SHT_REL; this_hdr->sh_entsize = sizeof (Elf_External_Rel); } else if (strcmp (asect->name, ".note") == 0) this_hdr->sh_type = SHT_NOTE; else if (strncmp (asect->name, ".stab", 5) == 0 && strcmp (asect->name + strlen (asect->name) - 3, "str") == 0) this_hdr->sh_type = SHT_STRTAB; else if ((asect->flags & SEC_ALLOC) != 0 && (asect->flags & SEC_LOAD) != 0) this_hdr->sh_type = SHT_PROGBITS; else if ((asect->flags & SEC_ALLOC) != 0 && ((asect->flags & SEC_LOAD) == 0)) { BFD_ASSERT (strcmp (asect->name, ".bss") == 0 || strcmp (asect->name, ".sbss") == 0); this_hdr->sh_type = SHT_NOBITS; } else { /* Who knows? */ this_hdr->sh_type = SHT_PROGBITS; } if ((asect->flags & SEC_ALLOC) != 0) this_hdr->sh_flags |= SHF_ALLOC; if ((asect->flags & SEC_READONLY) == 0) this_hdr->sh_flags |= SHF_WRITE; if ((asect->flags & SEC_CODE) != 0) this_hdr->sh_flags |= SHF_EXECINSTR; /* Check for processor-specific section types. */ { struct elf_backend_data *bed = get_elf_backend_data (abfd); if (bed->elf_backend_fake_sections) (*bed->elf_backend_fake_sections) (abfd, this_hdr, asect); } /* If the section has relocs, set up a section header for the SHT_REL[A] section. */ if ((asect->flags & SEC_RELOC) != 0) { Elf_Internal_Shdr *rela_hdr; int use_rela_p = get_elf_backend_data (abfd)->use_rela_p; rela_hdr = &elf_section_data (asect)->rel_hdr; rela_hdr->sh_name = bfd_add_2_to_strtab (abfd, elf_shstrtab (abfd), use_rela_p ? ".rela" : ".rel", asect->name); rela_hdr->sh_type = use_rela_p ? SHT_RELA : SHT_REL; rela_hdr->sh_entsize = (use_rela_p ? sizeof (Elf_External_Rela) : sizeof (Elf_External_Rel)); rela_hdr->sh_addralign = FILE_ALIGN; rela_hdr->sh_flags = 0; rela_hdr->sh_addr = 0; rela_hdr->sh_size = 0; rela_hdr->sh_offset = 0; rela_hdr->size = 0; } } /* Assign all ELF section numbers. The dummy first section is handled here too. The link/info pointers for the standard section types are filled in here too, while we're at it. */ static boolean assign_section_numbers (abfd) bfd *abfd; { struct elf_obj_tdata *t = elf_tdata (abfd); asection *sec; unsigned int section_number; Elf_Internal_Shdr **i_shdrp; section_number = 1; for (sec = abfd->sections; sec; sec = sec->next) { struct bfd_elf_section_data *d = elf_section_data (sec); d->this_idx = section_number++; if ((sec->flags & SEC_RELOC) == 0) d->rel_idx = 0; else d->rel_idx = section_number++; } t->shstrtab_section = section_number++; elf_elfheader (abfd)->e_shstrndx = t->shstrtab_section; t->shstrtab_hdr.sh_size = elf_shstrtab (abfd)->length; t->shstrtab_hdr.contents = (PTR) elf_shstrtab (abfd)->tab; if (abfd->symcount > 0) { t->symtab_section = section_number++; t->strtab_section = section_number++; } elf_elfheader (abfd)->e_shnum = section_number; /* Set up the list of section header pointers, in agreement with the indices. */ i_shdrp = ((Elf_Internal_Shdr **) bfd_alloc (abfd, section_number * sizeof (Elf_Internal_Shdr *))); if (i_shdrp == NULL) { bfd_set_error (bfd_error_no_memory); return false; } i_shdrp[0] = ((Elf_Internal_Shdr *) bfd_alloc (abfd, sizeof (Elf_Internal_Shdr))); if (i_shdrp[0] == NULL) { bfd_release (abfd, i_shdrp); bfd_set_error (bfd_error_no_memory); return false; } memset (i_shdrp[0], 0, sizeof (Elf_Internal_Shdr)); elf_elfsections (abfd) = i_shdrp; i_shdrp[t->shstrtab_section] = &t->shstrtab_hdr; if (abfd->symcount > 0) { i_shdrp[t->symtab_section] = &t->symtab_hdr; i_shdrp[t->strtab_section] = &t->strtab_hdr; t->symtab_hdr.sh_link = t->strtab_section; } for (sec = abfd->sections; sec; sec = sec->next) { struct bfd_elf_section_data *d = elf_section_data (sec); asection *s; const char *name; i_shdrp[d->this_idx] = &d->this_hdr; if (d->rel_idx != 0) i_shdrp[d->rel_idx] = &d->rel_hdr; /* Fill in the sh_link and sh_info fields while we're at it. */ /* sh_link of a reloc section is the section index of the symbol table. sh_info is the section index of the section to which the relocation entries apply. */ if (d->rel_idx != 0) { d->rel_hdr.sh_link = t->symtab_section; d->rel_hdr.sh_info = d->this_idx; } switch (d->this_hdr.sh_type) { case SHT_REL: case SHT_RELA: /* A reloc section which we are treating as a normal BFD section. sh_link is the section index of the symbol table. sh_info is the section index of the section to which the relocation entries apply. We assume that an allocated reloc section uses the dynamic symbol table. FIXME: How can we be sure? */ s = bfd_get_section_by_name (abfd, ".dynsym"); if (s != NULL) d->this_hdr.sh_link = elf_section_data (s)->this_idx; /* We look up the section the relocs apply to by name. */ name = sec->name; if (d->this_hdr.sh_type == SHT_REL) name += 4; else name += 5; s = bfd_get_section_by_name (abfd, name); if (s != NULL) d->this_hdr.sh_info = elf_section_data (s)->this_idx; break; case SHT_STRTAB: /* We assume that a section named .stab*str is a stabs string section. We look for a section with the same name but without the trailing ``str'', and set its sh_link field to point to this section. */ if (strncmp (sec->name, ".stab", sizeof ".stab" - 1) == 0 && strcmp (sec->name + strlen (sec->name) - 3, "str") == 0) { size_t len; char *alc; len = strlen (sec->name); alc = (char *) malloc (len - 2); if (alc == NULL) { bfd_set_error (bfd_error_no_memory); return false; } strncpy (alc, sec->name, len - 3); alc[len - 3] = '\0'; s = bfd_get_section_by_name (abfd, alc); free (alc); if (s != NULL) { elf_section_data (s)->this_hdr.sh_link = d->this_idx; /* This is a .stab section. */ elf_section_data (s)->this_hdr.sh_entsize = 4 + 2 * (ARCH_SIZE / 8); } } break; case SHT_DYNAMIC: case SHT_DYNSYM: /* sh_link is the section header index of the string table used for the dynamic entries or symbol table. */ s = bfd_get_section_by_name (abfd, ".dynstr"); if (s != NULL) d->this_hdr.sh_link = elf_section_data (s)->this_idx; break; case SHT_HASH: /* sh_link is the section header index of the symbol table this hash table is for. */ s = bfd_get_section_by_name (abfd, ".dynsym"); if (s != NULL) d->this_hdr.sh_link = elf_section_data (s)->this_idx; break; } } return true; } /* Map symbol from it's internal number to the external number, moving all local symbols to be at the head of the list. */ static INLINE int sym_is_global (abfd, sym) bfd *abfd; asymbol *sym; { /* If the backend has a special mapping, use it. */ if (get_elf_backend_data (abfd)->elf_backend_sym_is_global) return ((*get_elf_backend_data (abfd)->elf_backend_sym_is_global) (abfd, sym)); if (sym->flags & (BSF_GLOBAL | BSF_WEAK)) { if (sym->flags & BSF_LOCAL) abort (); return 1; } if (sym->section == 0) { /* Is this valid? */ abort (); return 1; } if (bfd_is_und_section (sym->section)) return 1; if (bfd_is_com_section (sym->section)) return 1; if (sym->flags & (BSF_LOCAL | BSF_SECTION_SYM | BSF_FILE)) return 0; return 0; } static boolean elf_map_symbols (abfd) bfd *abfd; { int symcount = bfd_get_symcount (abfd); asymbol **syms = bfd_get_outsymbols (abfd); asymbol **sect_syms; int num_locals = 0; int num_globals = 0; int num_locals2 = 0; int num_globals2 = 0; int max_index = 0; int num_sections = 0; Elf_Sym_Extra *sym_extra; int idx; asection *asect; #ifdef DEBUG fprintf (stderr, "elf_map_symbols\n"); fflush (stderr); #endif /* Add local symbols for each section for which there are relocs. FIXME: How can we tell which sections have relocs at this point? Will reloc_count always be accurate? Actually, I think most ELF targets create section symbols for all sections anyhow. */ for (asect = abfd->sections; asect; asect = asect->next) { if (max_index < asect->index) max_index = asect->index; } max_index++; elf_num_section_syms (abfd) = max_index; sect_syms = (asymbol **) bfd_zalloc (abfd, max_index * sizeof (asymbol *)); elf_section_syms (abfd) = sect_syms; if (sect_syms == 0) { bfd_set_error (bfd_error_no_memory); return false; } for (asect = abfd->sections; asect; asect = asect->next) { asymbol *sym = bfd_make_empty_symbol (abfd); if (!sym) { bfd_set_error (bfd_error_no_memory); return false; } sym->the_bfd = abfd; sym->name = asect->name; sym->value = asect->vma; sym->flags = BSF_SECTION_SYM; sym->section = asect; sect_syms[asect->index] = sym; num_sections++; #ifdef DEBUG fprintf (stderr, "creating section symbol, name = %s, value = 0x%.8lx, index = %d, section = 0x%.8lx\n", asect->name, (long) asect->vma, asect->index, (long) asect); #endif } if (num_sections) { if (syms) syms = (asymbol **) bfd_realloc (abfd, syms, ((symcount + num_sections + 1) * sizeof (asymbol *))); else syms = (asymbol **) bfd_alloc (abfd, (num_sections + 1) * sizeof (asymbol *)); if (!syms) { bfd_set_error (bfd_error_no_memory); return false; } for (asect = abfd->sections; asect; asect = asect->next) { if (sect_syms[asect->index]) syms[symcount++] = sect_syms[asect->index]; } syms[symcount] = (asymbol *) 0; bfd_set_symtab (abfd, syms, symcount); } elf_sym_extra (abfd) = sym_extra = (Elf_Sym_Extra *) bfd_alloc (abfd, symcount * sizeof (Elf_Sym_Extra)); if (!sym_extra) { bfd_set_error (bfd_error_no_memory); return false; } /* Identify and classify all of the symbols. */ for (idx = 0; idx < symcount; idx++) { if (!sym_is_global (abfd, syms[idx])) num_locals++; else num_globals++; } /* Now provide mapping information. Add +1 for skipping over the dummy symbol. */ for (idx = 0; idx < symcount; idx++) { syms[idx]->udata = (PTR) & sym_extra[idx]; if (!sym_is_global (abfd, syms[idx])) sym_extra[idx].elf_sym_num = 1 + num_locals2++; else sym_extra[idx].elf_sym_num = 1 + num_locals + num_globals2++; } elf_num_locals (abfd) = num_locals; elf_num_globals (abfd) = num_globals; return true; } /* Compute the file positions we are going to put the sections at, and otherwise prepare to begin writing out the ELF file. If LINK_INFO is not NULL, this is being called by the ELF backend linker. */ static boolean elf_compute_section_file_positions (abfd, link_info) bfd *abfd; struct bfd_link_info *link_info; { struct elf_backend_data *bed = get_elf_backend_data (abfd); Elf_Internal_Shdr *shstrtab_hdr; if (abfd->output_has_begun) return true; /* Do any elf backend specific processing first. */ if (bed->elf_backend_begin_write_processing) (*bed->elf_backend_begin_write_processing) (abfd, link_info); if (! prep_headers (abfd)) return false; bfd_map_over_sections (abfd, elf_fake_sections, 0); if (!assign_section_numbers (abfd)) return false; /* The backend linker builds symbol table information itself. */ if (link_info == NULL) { if (! swap_out_syms (abfd)) return false; } shstrtab_hdr = &elf_tdata (abfd)->shstrtab_hdr; /* sh_name was set in prep_headers. */ shstrtab_hdr->sh_type = SHT_STRTAB; shstrtab_hdr->sh_flags = 0; shstrtab_hdr->sh_addr = 0; shstrtab_hdr->sh_size = elf_shstrtab (abfd)->length; shstrtab_hdr->sh_entsize = 0; shstrtab_hdr->sh_link = 0; shstrtab_hdr->sh_info = 0; /* sh_offset is set in assign_file_positions_for_symtabs_and_strtabs. */ shstrtab_hdr->sh_addralign = 1; shstrtab_hdr->contents = (PTR) elf_shstrtab (abfd)->tab; if (!assign_file_positions_except_relocs (abfd, link_info == NULL ? true : false)) return false; abfd->output_has_begun = true; return true; } /* Align to the maximum file alignment that could be required for any ELF data structure. */ static INLINE file_ptr align_file_position (off) file_ptr off; { return (off + FILE_ALIGN - 1) & ~(FILE_ALIGN - 1); } /* Assign a file position to a section, optionally aligning to the required section alignment. */ static INLINE file_ptr assign_file_position_for_section (i_shdrp, offset, align) Elf_Internal_Shdr *i_shdrp; file_ptr offset; boolean align; { if (align) { unsigned int al; al = i_shdrp->sh_addralign; if (al > 1) offset = BFD_ALIGN (offset, al); } i_shdrp->sh_offset = offset; if (i_shdrp->rawdata != NULL) ((asection *) i_shdrp->rawdata)->filepos = offset; if (i_shdrp->sh_type != SHT_NOBITS) offset += i_shdrp->sh_size; return offset; } /* Get the size of the program header. This is called by the linker before any of the section VMA's are set, so it can't calculate the correct value for a strange memory layout. */ static bfd_size_type get_program_header_size (abfd) bfd *abfd; { size_t segs; asection *s; /* Assume we will need exactly two PT_LOAD segments: one for text and one for data. */ segs = 2; s = bfd_get_section_by_name (abfd, ".interp"); if (s != NULL && (s->flags & SEC_LOAD) != 0) { /* If we have a loadable interpreter section, we need a PT_INTERP segment. In this case, assume we also need a PT_PHDR segment, although that may not be true for all targets. */ segs += 2; } if (bfd_get_section_by_name (abfd, ".dynamic") != NULL) { /* We need a PT_DYNAMIC segment. */ ++segs; } return segs * sizeof (Elf_External_Phdr); } /* Create the program header. OFF is the file offset where the program header should be written. FIRST is the first loadable ELF section. PHDR_SIZE is the size of the program header as returned by get_program_header_size. */ static file_ptr map_program_segments (abfd, off, first, phdr_size) bfd *abfd; file_ptr off; Elf_Internal_Shdr *first; bfd_size_type phdr_size; { Elf_Internal_Phdr phdrs[10]; unsigned int phdr_count; Elf_Internal_Phdr *phdr; int phdr_size_adjust; unsigned int i; Elf_Internal_Shdr **hdrpp; asection *sinterp, *sdyn; unsigned int last_type; Elf_Internal_Ehdr *i_ehdrp; BFD_ASSERT ((abfd->flags & (EXEC_P | DYNAMIC)) != 0); BFD_ASSERT (phdr_size / sizeof (Elf_Internal_Phdr) <= sizeof phdrs / sizeof (phdrs[0])); phdr_count = 0; phdr = phdrs; phdr_size_adjust = 0; /* If we have a loadable .interp section, we must create a PT_INTERP segment which must precede all PT_LOAD segments. We assume that we must also create a PT_PHDR segment, although that may not be true for all targets. */ sinterp = bfd_get_section_by_name (abfd, ".interp"); if (sinterp != NULL && (sinterp->flags & SEC_LOAD) != 0) { BFD_ASSERT (first != NULL); phdr->p_type = PT_PHDR; phdr->p_offset = off; /* Account for any adjustment made because of the alignment of the first loadable section. */ phdr_size_adjust = (first->sh_offset - phdr_size) - off; BFD_ASSERT (phdr_size_adjust >= 0 && phdr_size_adjust < 128); /* The program header precedes all loadable sections. This lets us compute its loadable address. This depends on the linker script. */ phdr->p_vaddr = first->sh_addr - (phdr_size + phdr_size_adjust); phdr->p_paddr = 0; phdr->p_filesz = phdr_size; phdr->p_memsz = phdr_size; /* FIXME: UnixWare and Solaris set PF_X, Irix 5 does not. */ phdr->p_flags = PF_R | PF_X; phdr->p_align = FILE_ALIGN; BFD_ASSERT ((phdr->p_vaddr - phdr->p_offset) % FILE_ALIGN == 0); /* Include the ELF header in the first loadable segment. */ phdr_size_adjust += off; ++phdr_count; ++phdr; phdr->p_type = PT_INTERP; phdr->p_offset = sinterp->filepos; phdr->p_vaddr = sinterp->vma; phdr->p_paddr = 0; phdr->p_filesz = sinterp->_raw_size; phdr->p_memsz = sinterp->_raw_size; phdr->p_flags = PF_R; phdr->p_align = 1 << bfd_get_section_alignment (abfd, sinterp); ++phdr_count; ++phdr; } /* Look through the sections to see how they will be divided into program segments. The sections must be arranged in order by sh_addr for this to work correctly. */ phdr->p_type = PT_NULL; last_type = SHT_PROGBITS; for (i = 1, hdrpp = elf_elfsections (abfd) + 1; i < elf_elfheader (abfd)->e_shnum; i++, hdrpp++) { Elf_Internal_Shdr *hdr; hdr = *hdrpp; /* Ignore any section which will not be part of the process image. */ if ((hdr->sh_flags & SHF_ALLOC) == 0) continue; /* If this section fits in the segment we are constructing, add it in. */ if (phdr->p_type != PT_NULL && (hdr->sh_offset - (phdr->p_offset + phdr->p_memsz) == hdr->sh_addr - (phdr->p_vaddr + phdr->p_memsz)) && (last_type != SHT_NOBITS || hdr->sh_type == SHT_NOBITS)) { bfd_size_type adjust; adjust = hdr->sh_addr - (phdr->p_vaddr + phdr->p_memsz); phdr->p_memsz += hdr->sh_size + adjust; if (hdr->sh_type != SHT_NOBITS) phdr->p_filesz += hdr->sh_size + adjust; if ((hdr->sh_flags & SHF_WRITE) != 0) phdr->p_flags |= PF_W; if ((hdr->sh_flags & SHF_EXECINSTR) != 0) phdr->p_flags |= PF_X; last_type = hdr->sh_type; continue; } /* If we have a segment, move to the next one. */ if (phdr->p_type != PT_NULL) { ++phdr; ++phdr_count; } /* Start a new segment. */ phdr->p_type = PT_LOAD; phdr->p_offset = hdr->sh_offset; phdr->p_vaddr = hdr->sh_addr; phdr->p_paddr = 0; if (hdr->sh_type == SHT_NOBITS) phdr->p_filesz = 0; else phdr->p_filesz = hdr->sh_size; phdr->p_memsz = hdr->sh_size; phdr->p_flags = PF_R; if ((hdr->sh_flags & SHF_WRITE) != 0) phdr->p_flags |= PF_W; if ((hdr->sh_flags & SHF_EXECINSTR) != 0) phdr->p_flags |= PF_X; phdr->p_align = get_elf_backend_data (abfd)->maxpagesize; if (hdr == first && sinterp != NULL && (sinterp->flags & SEC_LOAD) != 0) { phdr->p_offset -= phdr_size + phdr_size_adjust; phdr->p_vaddr -= phdr_size + phdr_size_adjust; phdr->p_filesz += phdr_size + phdr_size_adjust; phdr->p_memsz += phdr_size + phdr_size_adjust; } last_type = hdr->sh_type; } if (phdr->p_type != PT_NULL) { ++phdr; ++phdr_count; } /* If we have a .dynamic section, create a PT_DYNAMIC segment. */ sdyn = bfd_get_section_by_name (abfd, ".dynamic"); if (sdyn != NULL && (sdyn->flags & SEC_LOAD) != 0) { phdr->p_type = PT_DYNAMIC; phdr->p_offset = sdyn->filepos; phdr->p_vaddr = sdyn->vma; phdr->p_paddr = 0; phdr->p_filesz = sdyn->_raw_size; phdr->p_memsz = sdyn->_raw_size; phdr->p_flags = PF_R; if ((sdyn->flags & SEC_READONLY) == 0) phdr->p_flags |= PF_W; if ((sdyn->flags & SEC_CODE) != 0) phdr->p_flags |= PF_X; phdr->p_align = 1 << bfd_get_section_alignment (abfd, sdyn); ++phdr; ++phdr_count; } /* Make sure the return value from get_program_header_size matches what we computed here. Actually, it's OK if we allocated too much space in the program header. */ if (phdr_count > phdr_size / sizeof (Elf_External_Phdr)) abort (); /* Set up program header information. */ i_ehdrp = elf_elfheader (abfd); i_ehdrp->e_phentsize = sizeof (Elf_External_Phdr); i_ehdrp->e_phoff = off; i_ehdrp->e_phnum = phdr_count; /* Save the program headers away. I don't think anybody uses this information right now. */ elf_tdata (abfd)->phdr = ((Elf_Internal_Phdr *) bfd_alloc (abfd, (phdr_count * sizeof (Elf_Internal_Phdr)))); if (elf_tdata (abfd)->phdr == NULL && phdr_count != 0) { bfd_set_error (bfd_error_no_memory); return (file_ptr) -1; } memcpy (elf_tdata (abfd)->phdr, phdrs, phdr_count * sizeof (Elf_Internal_Phdr)); /* Write out the program headers. */ if (bfd_seek (abfd, off, SEEK_SET) != 0) return (file_ptr) -1; for (i = 0, phdr = phdrs; i < phdr_count; i++, phdr++) { Elf_External_Phdr extphdr; elf_swap_phdr_out (abfd, phdr, &extphdr); if (bfd_write (&extphdr, sizeof (Elf_External_Phdr), 1, abfd) != sizeof (Elf_External_Phdr)) return (file_ptr) -1; } return off + phdr_count * sizeof (Elf_External_Phdr); } /* Work out the file positions of all the sections. This is called by elf_compute_section_file_positions. All the section sizes and VMAs must be known before this is called. We do not consider reloc sections at this point, unless they form part of the loadable image. Reloc sections are assigned file positions in assign_file_positions_for_relocs, which is called by write_object_contents and final_link. If DOSYMS is false, we do not assign file positions for the symbol table or the string table. */ static boolean assign_file_positions_except_relocs (abfd, dosyms) bfd *abfd; boolean dosyms; { struct elf_obj_tdata * const tdata = elf_tdata (abfd); Elf_Internal_Ehdr * const i_ehdrp = elf_elfheader (abfd); Elf_Internal_Shdr ** const i_shdrpp = elf_elfsections (abfd); file_ptr off; /* Start after the ELF header. */ off = i_ehdrp->e_ehsize; if ((abfd->flags & (EXEC_P | DYNAMIC)) == 0) { Elf_Internal_Shdr **hdrpp; unsigned int i; /* We are not creating an executable, which means that we are not creating a program header, and that the actual order of the sections in the file is unimportant. */ for (i = 1, hdrpp = i_shdrpp + 1; i < i_ehdrp->e_shnum; i++, hdrpp++) { Elf_Internal_Shdr *hdr; hdr = *hdrpp; if (hdr->sh_type == SHT_REL || hdr->sh_type == SHT_RELA) { hdr->sh_offset = -1; continue; } if (! dosyms && (i == tdata->symtab_section || i == tdata->strtab_section)) { hdr->sh_offset = -1; continue; } off = assign_file_position_for_section (hdr, off, true); } } else { file_ptr phdr_off; bfd_size_type phdr_size; bfd_vma maxpagesize; Elf_Internal_Shdr **hdrpp; unsigned int i; Elf_Internal_Shdr *first; file_ptr phdr_map; /* We are creating an executable. We must create a program header. We can't actually create the program header until we have set the file positions for the sections, but we can figure out how big it is going to be. */ off = align_file_position (off); phdr_size = get_program_header_size (abfd); if (phdr_size == (file_ptr) -1) return false; phdr_off = off; off += phdr_size; maxpagesize = get_elf_backend_data (abfd)->maxpagesize; if (maxpagesize == 0) maxpagesize = 1; /* FIXME: We might want to sort the sections on the sh_addr field here. For now, we just assume that the linker will create the sections in an appropriate order. */ /* Assign file positions in two passes. In the first pass, we assign a file position to every section which forms part of the executable image. */ first = NULL; for (i = 1, hdrpp = i_shdrpp + 1; i < i_ehdrp->e_shnum; i++, hdrpp++) { Elf_Internal_Shdr *hdr; hdr = *hdrpp; if ((hdr->sh_flags & SHF_ALLOC) == 0) continue; if (first == NULL) first = hdr; /* The section VMA must equal the file position modulo the page size. This is required by the program header. */ off += (hdr->sh_addr - off) % maxpagesize; off = assign_file_position_for_section (hdr, off, false); } /* Assign file positions to all the sections which do not form part of the loadable image, except for the relocs. */ for (i = 1, hdrpp = i_shdrpp + 1; i < i_ehdrp->e_shnum; i++, hdrpp++) { Elf_Internal_Shdr *hdr; hdr = *hdrpp; if ((hdr->sh_flags & SHF_ALLOC) != 0) continue; if (hdr->sh_type == SHT_REL || hdr->sh_type == SHT_RELA) { hdr->sh_offset = -1; continue; } if (! dosyms && (i == tdata->symtab_section || i == tdata->strtab_section)) { hdr->sh_offset = -1; continue; } off = assign_file_position_for_section (hdr, off, true); } phdr_map = map_program_segments (abfd, phdr_off, first, phdr_size); if (phdr_map == (file_ptr) -1) return false; BFD_ASSERT (phdr_map <= phdr_off + phdr_size); } /* Place the section headers. */ off = align_file_position (off); i_ehdrp->e_shoff = off; off += i_ehdrp->e_shnum * i_ehdrp->e_shentsize; elf_tdata (abfd)->next_file_pos = off; return true; } static boolean prep_headers (abfd) bfd *abfd; { Elf_Internal_Ehdr *i_ehdrp; /* Elf file header, internal form */ Elf_Internal_Phdr *i_phdrp = 0; /* Program header table, internal form */ Elf_Internal_Shdr **i_shdrp; /* Section header table, internal form */ int count; struct strtab *shstrtab; i_ehdrp = elf_elfheader (abfd); i_shdrp = elf_elfsections (abfd); shstrtab = bfd_new_strtab (abfd); if (!shstrtab) return false; elf_shstrtab (abfd) = shstrtab; i_ehdrp->e_ident[EI_MAG0] = ELFMAG0; i_ehdrp->e_ident[EI_MAG1] = ELFMAG1; i_ehdrp->e_ident[EI_MAG2] = ELFMAG2; i_ehdrp->e_ident[EI_MAG3] = ELFMAG3; i_ehdrp->e_ident[EI_CLASS] = ELFCLASS; i_ehdrp->e_ident[EI_DATA] = abfd->xvec->byteorder_big_p ? ELFDATA2MSB : ELFDATA2LSB; i_ehdrp->e_ident[EI_VERSION] = EV_CURRENT; for (count = EI_PAD; count < EI_NIDENT; count++) i_ehdrp->e_ident[count] = 0; if ((abfd->flags & DYNAMIC) != 0) i_ehdrp->e_type = ET_DYN; else if ((abfd->flags & EXEC_P) != 0) i_ehdrp->e_type = ET_EXEC; else i_ehdrp->e_type = ET_REL; switch (bfd_get_arch (abfd)) { case bfd_arch_unknown: i_ehdrp->e_machine = EM_NONE; break; case bfd_arch_sparc: #if ARCH_SIZE == 64 i_ehdrp->e_machine = EM_SPARC64; #else i_ehdrp->e_machine = EM_SPARC; #endif break; case bfd_arch_i386: i_ehdrp->e_machine = EM_386; break; case bfd_arch_m68k: i_ehdrp->e_machine = EM_68K; break; case bfd_arch_m88k: i_ehdrp->e_machine = EM_88K; break; case bfd_arch_i860: i_ehdrp->e_machine = EM_860; break; case bfd_arch_mips: /* MIPS Rxxxx */ i_ehdrp->e_machine = EM_MIPS; /* only MIPS R3000 */ break; case bfd_arch_hppa: i_ehdrp->e_machine = EM_PARISC; break; case bfd_arch_powerpc: i_ehdrp->e_machine = EM_CYGNUS_POWERPC; break; /* also note that EM_M32, AT&T WE32100 is unknown to bfd */ default: i_ehdrp->e_machine = EM_NONE; } i_ehdrp->e_version = EV_CURRENT; i_ehdrp->e_ehsize = sizeof (Elf_External_Ehdr); /* no program header, for now. */ i_ehdrp->e_phoff = 0; i_ehdrp->e_phentsize = 0; i_ehdrp->e_phnum = 0; /* each bfd section is section header entry */ i_ehdrp->e_entry = bfd_get_start_address (abfd); i_ehdrp->e_shentsize = sizeof (Elf_External_Shdr); /* if we're building an executable, we'll need a program header table */ if (abfd->flags & EXEC_P) { /* it all happens later */ #if 0 i_ehdrp->e_phentsize = sizeof (Elf_External_Phdr); /* elf_build_phdrs() returns a (NULL-terminated) array of Elf_Internal_Phdrs */ i_phdrp = elf_build_phdrs (abfd, i_ehdrp, i_shdrp, &i_ehdrp->e_phnum); i_ehdrp->e_phoff = outbase; outbase += i_ehdrp->e_phentsize * i_ehdrp->e_phnum; #endif } else { i_ehdrp->e_phentsize = 0; i_phdrp = 0; i_ehdrp->e_phoff = 0; } elf_tdata (abfd)->symtab_hdr.sh_name = bfd_add_to_strtab (abfd, shstrtab, ".symtab"); elf_tdata (abfd)->strtab_hdr.sh_name = bfd_add_to_strtab (abfd, shstrtab, ".strtab"); elf_tdata (abfd)->shstrtab_hdr.sh_name = bfd_add_to_strtab (abfd, shstrtab, ".shstrtab"); if (elf_tdata (abfd)->symtab_hdr.sh_name == (unsigned int) -1 || elf_tdata (abfd)->symtab_hdr.sh_name == (unsigned int) -1 || elf_tdata (abfd)->shstrtab_hdr.sh_name == (unsigned int) -1) return false; return true; } static boolean swap_out_syms (abfd) bfd *abfd; { if (!elf_map_symbols (abfd)) return false; /* Dump out the symtabs. */ { int symcount = bfd_get_symcount (abfd); asymbol **syms = bfd_get_outsymbols (abfd); struct strtab *stt = bfd_new_strtab (abfd); Elf_Internal_Shdr *symtab_hdr; Elf_Internal_Shdr *symstrtab_hdr; Elf_External_Sym *outbound_syms; int idx; if (!stt) return false; symtab_hdr = &elf_tdata (abfd)->symtab_hdr; symtab_hdr->sh_type = SHT_SYMTAB; symtab_hdr->sh_entsize = sizeof (Elf_External_Sym); symtab_hdr->sh_size = symtab_hdr->sh_entsize * (symcount + 1); symtab_hdr->sh_info = elf_num_locals (abfd) + 1; symtab_hdr->sh_addralign = FILE_ALIGN; symstrtab_hdr = &elf_tdata (abfd)->strtab_hdr; symstrtab_hdr->sh_type = SHT_STRTAB; outbound_syms = (Elf_External_Sym *) bfd_alloc (abfd, (1 + symcount) * sizeof (Elf_External_Sym)); if (!outbound_syms) { bfd_set_error (bfd_error_no_memory); return false; } /* now generate the data (for "contents") */ { /* Fill in zeroth symbol and swap it out. */ Elf_Internal_Sym sym; sym.st_name = 0; sym.st_value = 0; sym.st_size = 0; sym.st_info = 0; sym.st_other = 0; sym.st_shndx = SHN_UNDEF; elf_swap_symbol_out (abfd, &sym, outbound_syms); } for (idx = 0; idx < symcount; idx++) { Elf_Internal_Sym sym; bfd_vma value = syms[idx]->value; elf_symbol_type *type_ptr; if (syms[idx]->flags & BSF_SECTION_SYM) /* Section symbols have no names. */ sym.st_name = 0; else { sym.st_name = bfd_add_to_strtab (abfd, stt, syms[idx]->name); if (sym.st_name == (unsigned long) -1) return false; } type_ptr = elf_symbol_from (abfd, syms[idx]); if (bfd_is_com_section (syms[idx]->section)) { /* ELF common symbols put the alignment into the `value' field, and the size into the `size' field. This is backwards from how BFD handles it, so reverse it here. */ sym.st_size = value; if (type_ptr == NULL || type_ptr->internal_elf_sym.st_value == 0) sym.st_value = value >= 16 ? 16 : (1 << bfd_log2 (value)); else sym.st_value = type_ptr->internal_elf_sym.st_value; sym.st_shndx = elf_section_from_bfd_section (abfd, syms[idx]->section); } else { asection *sec = syms[idx]->section; int shndx; if (sec->output_section) { value += sec->output_offset; sec = sec->output_section; } value += sec->vma; sym.st_value = value; sym.st_size = type_ptr ? type_ptr->internal_elf_sym.st_size : 0; sym.st_shndx = shndx = elf_section_from_bfd_section (abfd, sec); if (shndx == -1) { asection *sec2; /* Writing this would be a hell of a lot easier if we had some decent documentation on bfd, and knew what to expect of the library, and what to demand of applications. For example, it appears that `objcopy' might not set the section of a symbol to be a section that is actually in the output file. */ sec2 = bfd_get_section_by_name (abfd, sec->name); BFD_ASSERT (sec2 != 0); sym.st_shndx = shndx = elf_section_from_bfd_section (abfd, sec2); BFD_ASSERT (shndx != -1); } } if (bfd_is_com_section (syms[idx]->section)) sym.st_info = ELF_ST_INFO (STB_GLOBAL, STT_OBJECT); else if (bfd_is_und_section (syms[idx]->section)) sym.st_info = ELF_ST_INFO (STB_GLOBAL, ((syms[idx]->flags & BSF_FUNCTION) ? STT_FUNC : STT_NOTYPE)); else if (syms[idx]->flags & BSF_SECTION_SYM) sym.st_info = ELF_ST_INFO (STB_LOCAL, STT_SECTION); else if (syms[idx]->flags & BSF_FILE) sym.st_info = ELF_ST_INFO (STB_LOCAL, STT_FILE); else { int bind = STB_LOCAL; int type = STT_OBJECT; unsigned int flags = syms[idx]->flags; if (flags & BSF_LOCAL) bind = STB_LOCAL; else if (flags & BSF_WEAK) bind = STB_WEAK; else if (flags & BSF_GLOBAL) bind = STB_GLOBAL; if (flags & BSF_FUNCTION) type = STT_FUNC; sym.st_info = ELF_ST_INFO (bind, type); } sym.st_other = 0; elf_swap_symbol_out (abfd, &sym, (outbound_syms + elf_sym_extra (abfd)[idx].elf_sym_num)); } symtab_hdr->contents = (PTR) outbound_syms; symstrtab_hdr->contents = (PTR) stt->tab; symstrtab_hdr->sh_size = stt->length; symstrtab_hdr->sh_type = SHT_STRTAB; symstrtab_hdr->sh_flags = 0; symstrtab_hdr->sh_addr = 0; symstrtab_hdr->sh_entsize = 0; symstrtab_hdr->sh_link = 0; symstrtab_hdr->sh_info = 0; symstrtab_hdr->sh_addralign = 1; symstrtab_hdr->size = 0; } return true; } static boolean write_shdrs_and_ehdr (abfd) bfd *abfd; { Elf_External_Ehdr x_ehdr; /* Elf file header, external form */ Elf_Internal_Ehdr *i_ehdrp; /* Elf file header, internal form */ Elf_External_Shdr *x_shdrp; /* Section header table, external form */ Elf_Internal_Shdr **i_shdrp; /* Section header table, internal form */ unsigned int count; struct strtab *shstrtab; i_ehdrp = elf_elfheader (abfd); i_shdrp = elf_elfsections (abfd); shstrtab = elf_shstrtab (abfd); /* swap the header before spitting it out... */ #if DEBUG & 1 elf_debug_file (i_ehdrp); #endif elf_swap_ehdr_out (abfd, i_ehdrp, &x_ehdr); if (bfd_seek (abfd, (file_ptr) 0, SEEK_SET) != 0 || (bfd_write ((PTR) & x_ehdr, sizeof (x_ehdr), 1, abfd) != sizeof (x_ehdr))) return false; /* at this point we've concocted all the ELF sections... */ x_shdrp = (Elf_External_Shdr *) bfd_alloc (abfd, sizeof (*x_shdrp) * (i_ehdrp->e_shnum)); if (!x_shdrp) { bfd_set_error (bfd_error_no_memory); return false; } for (count = 0; count < i_ehdrp->e_shnum; count++) { #if DEBUG & 2 elf_debug_section (shstrtab->tab + i_shdrp[count]->sh_name, count, i_shdrp[count]); #endif elf_swap_shdr_out (abfd, i_shdrp[count], x_shdrp + count); } if (bfd_seek (abfd, (file_ptr) i_ehdrp->e_shoff, SEEK_SET) != 0 || (bfd_write ((PTR) x_shdrp, sizeof (*x_shdrp), i_ehdrp->e_shnum, abfd) != sizeof (*x_shdrp) * i_ehdrp->e_shnum)) return false; /* need to dump the string table too... */ return true; } /* Assign file positions for all the reloc sections which are not part of the loadable file image. */ static void assign_file_positions_for_relocs (abfd) bfd *abfd; { file_ptr off; unsigned int i; Elf_Internal_Shdr **shdrpp; off = elf_tdata (abfd)->next_file_pos; for (i = 1, shdrpp = elf_elfsections (abfd) + 1; i < elf_elfheader (abfd)->e_shnum; i++, shdrpp++) { Elf_Internal_Shdr *shdrp; shdrp = *shdrpp; if ((shdrp->sh_type == SHT_REL || shdrp->sh_type == SHT_RELA) && shdrp->sh_offset == -1) off = assign_file_position_for_section (shdrp, off, true); } elf_tdata (abfd)->next_file_pos = off; } boolean NAME(bfd_elf,write_object_contents) (abfd) bfd *abfd; { struct elf_backend_data *bed = get_elf_backend_data (abfd); Elf_Internal_Ehdr *i_ehdrp; Elf_Internal_Shdr **i_shdrp; unsigned int count; if (! abfd->output_has_begun && ! elf_compute_section_file_positions (abfd, (struct bfd_link_info *) NULL)) return false; i_shdrp = elf_elfsections (abfd); i_ehdrp = elf_elfheader (abfd); bfd_map_over_sections (abfd, write_relocs, (PTR) 0); assign_file_positions_for_relocs (abfd); /* After writing the headers, we need to write the sections too... */ for (count = 1; count < i_ehdrp->e_shnum; count++) { if (bed->elf_backend_section_processing) (*bed->elf_backend_section_processing) (abfd, i_shdrp[count]); if (i_shdrp[count]->contents) { if (bfd_seek (abfd, i_shdrp[count]->sh_offset, SEEK_SET) != 0 || (bfd_write (i_shdrp[count]->contents, i_shdrp[count]->sh_size, 1, abfd) != i_shdrp[count]->sh_size)) return false; } } if (bed->elf_backend_final_write_processing) (*bed->elf_backend_final_write_processing) (abfd, elf_tdata (abfd)->linker); return write_shdrs_and_ehdr (abfd); } /* Given an index of a section, retrieve a pointer to it. Note that for our purposes, sections are indexed by {1, 2, ...} with 0 being an illegal index. */ /* In the original, each ELF section went into exactly one BFD section. This doesn't really make sense, so we need a real mapping. The mapping has to hide in the Elf_Internal_Shdr since asection doesn't have anything like a tdata field... */ static asection * section_from_elf_index (abfd, index) bfd *abfd; unsigned int index; { /* @@ Is bfd_com_section_ptr really correct in all the places it could be returned from this routine? */ if (index == SHN_ABS) return bfd_com_section_ptr; /* not abs? */ if (index == SHN_COMMON) return bfd_com_section_ptr; if (index >= elf_elfheader (abfd)->e_shnum) return NULL; { Elf_Internal_Shdr *hdr = elf_elfsections (abfd)[index]; switch (hdr->sh_type) { /* ELF sections that map to BFD sections */ case SHT_PROGBITS: case SHT_NOBITS: case SHT_HASH: case SHT_DYNAMIC: if (hdr->rawdata == NULL) { if (! bfd_section_from_shdr (abfd, index)) return NULL; } return (struct sec *) hdr->rawdata; default: return bfd_abs_section_ptr; } } } /* given a section, search the header to find them... */ static int elf_section_from_bfd_section (abfd, asect) bfd *abfd; struct sec *asect; { Elf_Internal_Shdr **i_shdrp = elf_elfsections (abfd); int index; Elf_Internal_Shdr *hdr; int maxindex = elf_elfheader (abfd)->e_shnum; if (asect->owner == NULL) { if (bfd_is_abs_section (asect)) return SHN_ABS; if (bfd_is_com_section (asect)) return SHN_COMMON; if (bfd_is_und_section (asect)) return SHN_UNDEF; return -1; } BFD_ASSERT (asect->owner == abfd); for (index = 0; index < maxindex; index++) { hdr = i_shdrp[index]; switch (hdr->sh_type) { /* ELF sections that map to BFD sections */ case SHT_PROGBITS: case SHT_NOBITS: case SHT_NOTE: case SHT_HASH: case SHT_DYNAMIC: case SHT_DYNSYM: case SHT_SYMTAB: if (hdr->rawdata) { if (((struct sec *) (hdr->rawdata)) == asect) return index; } break; case SHT_REL: case SHT_RELA: /* We sometimes map a reloc section to a BFD section. */ if (hdr->sh_link != elf_onesymtab (abfd) && (asection *) hdr->rawdata == asect) return index; break; case SHT_STRTAB: /* We map most string tables to BFD sections. */ if (index != elf_elfheader (abfd)->e_shstrndx && index != elf_onesymtab (abfd) && (asection *) hdr->rawdata == asect) return index; /* FALL THROUGH */ default: { struct elf_backend_data *bed = get_elf_backend_data (abfd); if (bed->elf_backend_section_from_bfd_section) { int retval; retval = index; if ((*bed->elf_backend_section_from_bfd_section) (abfd, hdr, asect, &retval)) return retval; } } break; } } return -1; } /* given a symbol, return the bfd index for that symbol. */ static int elf_symbol_from_bfd_symbol (abfd, asym_ptr_ptr) bfd *abfd; struct symbol_cache_entry **asym_ptr_ptr; { struct symbol_cache_entry *asym_ptr = *asym_ptr_ptr; int idx; flagword flags = asym_ptr->flags; /* When gas creates relocations against local labels, it creates its own symbol for the section, but does put the symbol into the symbol chain, so udata is 0. When the linker is generating relocatable output, this section symbol may be for one of the input sections rather than the output section. */ if (asym_ptr->udata == (PTR) 0 && (flags & BSF_SECTION_SYM) && asym_ptr->section) { int indx; if (asym_ptr->section->output_section != NULL) indx = asym_ptr->section->output_section->index; else indx = asym_ptr->section->index; if (elf_section_syms (abfd)[indx]) asym_ptr->udata = elf_section_syms (abfd)[indx]->udata; } if (asym_ptr->udata) idx = ((Elf_Sym_Extra *) asym_ptr->udata)->elf_sym_num; else { abort (); } #if DEBUG & 4 { fprintf (stderr, "elf_symbol_from_bfd_symbol 0x%.8lx, name = %s, sym num = %d, flags = 0x%.8lx %s\n", (long) asym_ptr, asym_ptr->name, idx, flags, elf_symbol_flags (flags)); fflush (stderr); } #endif return idx; } static long elf_slurp_symbol_table (abfd, symptrs, dynamic) bfd *abfd; asymbol **symptrs; /* Buffer for generated bfd symbols */ boolean dynamic; { Elf_Internal_Shdr *hdr; long symcount; /* Number of external ELF symbols */ elf_symbol_type *sym; /* Pointer to current bfd symbol */ elf_symbol_type *symbase; /* Buffer for generated bfd symbols */ Elf_Internal_Sym i_sym; Elf_External_Sym *x_symp = NULL; /* Read each raw ELF symbol, converting from external ELF form to internal ELF form, and then using the information to create a canonical bfd symbol table entry. Note that we allocate the initial bfd canonical symbol buffer based on a one-to-one mapping of the ELF symbols to canonical symbols. We actually use all the ELF symbols, so there will be no space left over at the end. When we have all the symbols, we build the caller's pointer vector. */ if (dynamic) hdr = &elf_tdata (abfd)->dynsymtab_hdr; else hdr = &elf_tdata (abfd)->symtab_hdr; if (bfd_seek (abfd, hdr->sh_offset, SEEK_SET) == -1) return -1; symcount = hdr->sh_size / sizeof (Elf_External_Sym); if (symcount == 0) sym = symbase = NULL; else { long i; if (bfd_seek (abfd, hdr->sh_offset, SEEK_SET) == -1) return -1; symbase = ((elf_symbol_type *) bfd_zalloc (abfd, symcount * sizeof (elf_symbol_type))); if (symbase == (elf_symbol_type *) NULL) { bfd_set_error (bfd_error_no_memory); return -1; } sym = symbase; /* Temporarily allocate room for the raw ELF symbols. */ x_symp = ((Elf_External_Sym *) malloc (symcount * sizeof (Elf_External_Sym))); if (x_symp == NULL && symcount != 0) { bfd_set_error (bfd_error_no_memory); goto error_return; } if (bfd_read ((PTR) x_symp, sizeof (Elf_External_Sym), symcount, abfd) != symcount * sizeof (Elf_External_Sym)) goto error_return; /* Skip first symbol, which is a null dummy. */ for (i = 1; i < symcount; i++) { elf_swap_symbol_in (abfd, x_symp + i, &i_sym); memcpy (&sym->internal_elf_sym, &i_sym, sizeof (Elf_Internal_Sym)); #ifdef ELF_KEEP_EXTSYM memcpy (&sym->native_elf_sym, x_symp + i, sizeof (Elf_External_Sym)); #endif sym->symbol.the_bfd = abfd; sym->symbol.name = elf_string_from_elf_section (abfd, hdr->sh_link, i_sym.st_name); sym->symbol.value = i_sym.st_value; if (i_sym.st_shndx > 0 && i_sym.st_shndx < SHN_LORESERVE) { sym->symbol.section = section_from_elf_index (abfd, i_sym.st_shndx); if (sym->symbol.section == NULL) { /* This symbol is in a section for which we did not create a BFD section. Just use bfd_abs_section, although it is wrong. FIXME. */ sym->symbol.section = bfd_abs_section_ptr; } } else if (i_sym.st_shndx == SHN_ABS) { sym->symbol.section = bfd_abs_section_ptr; } else if (i_sym.st_shndx == SHN_COMMON) { sym->symbol.section = bfd_com_section_ptr; /* Elf puts the alignment into the `value' field, and the size into the `size' field. BFD wants to see the size in the value field, and doesn't care (at the moment) about the alignment. */ sym->symbol.value = i_sym.st_size; } else if (i_sym.st_shndx == SHN_UNDEF) { sym->symbol.section = bfd_und_section_ptr; } else sym->symbol.section = bfd_abs_section_ptr; sym->symbol.value -= sym->symbol.section->vma; switch (ELF_ST_BIND (i_sym.st_info)) { case STB_LOCAL: sym->symbol.flags |= BSF_LOCAL; break; case STB_GLOBAL: sym->symbol.flags |= BSF_GLOBAL; break; case STB_WEAK: sym->symbol.flags |= BSF_WEAK; break; } switch (ELF_ST_TYPE (i_sym.st_info)) { case STT_SECTION: sym->symbol.flags |= BSF_SECTION_SYM | BSF_DEBUGGING; break; case STT_FILE: sym->symbol.flags |= BSF_FILE | BSF_DEBUGGING; break; case STT_FUNC: sym->symbol.flags |= BSF_FUNCTION; break; } if (dynamic) sym->symbol.flags |= BSF_DYNAMIC; /* Do some backend-specific processing on this symbol. */ { struct elf_backend_data *ebd = get_elf_backend_data (abfd); if (ebd->elf_backend_symbol_processing) (*ebd->elf_backend_symbol_processing) (abfd, &sym->symbol); } sym++; } } /* Do some backend-specific processing on this symbol table. */ { struct elf_backend_data *ebd = get_elf_backend_data (abfd); if (ebd->elf_backend_symbol_table_processing) (*ebd->elf_backend_symbol_table_processing) (abfd, symbase, symcount); } /* We rely on the zalloc to clear out the final symbol entry. */ symcount = sym - symbase; /* Fill in the user's symbol pointer vector if needed. */ if (symptrs) { long l = symcount; sym = symbase; while (l-- > 0) { *symptrs++ = &sym->symbol; sym++; } *symptrs = 0; /* Final null pointer */ } if (x_symp != NULL) free (x_symp); return symcount; error_return: if (x_symp != NULL) free (x_symp); return -1; } /* Return the number of bytes required to hold the symtab vector. Note that we base it on the count plus 1, since we will null terminate the vector allocated based on this size. However, the ELF symbol table always has a dummy entry as symbol #0, so it ends up even. */ long elf_get_symtab_upper_bound (abfd) bfd *abfd; { long symcount; long symtab_size; Elf_Internal_Shdr *hdr = &elf_tdata (abfd)->symtab_hdr; symcount = hdr->sh_size / sizeof (Elf_External_Sym); symtab_size = (symcount - 1 + 1) * (sizeof (asymbol *)); return symtab_size; } long elf_get_dynamic_symtab_upper_bound (abfd) bfd *abfd; { long symcount; long symtab_size; Elf_Internal_Shdr *hdr = &elf_tdata (abfd)->dynsymtab_hdr; if (elf_dynsymtab (abfd) == 0) { bfd_set_error (bfd_error_invalid_operation); return -1; } symcount = hdr->sh_size / sizeof (Elf_External_Sym); symtab_size = (symcount - 1 + 1) * (sizeof (asymbol *)); return symtab_size; } long elf_get_reloc_upper_bound (abfd, asect) bfd *abfd; sec_ptr asect; { return (asect->reloc_count + 1) * sizeof (arelent *); } /* Read in and swap the external relocs. */ static boolean elf_slurp_reloc_table (abfd, asect, symbols) bfd *abfd; asection *asect; asymbol **symbols; { struct elf_backend_data * const ebd = get_elf_backend_data (abfd); struct bfd_elf_section_data * const d = elf_section_data (asect); PTR allocated = NULL; bfd_byte *native_relocs; arelent *relents; arelent *relent; unsigned int i; int entsize; if (asect->relocation != NULL || (asect->flags & SEC_RELOC) == 0 || asect->reloc_count == 0) return true; BFD_ASSERT (asect->rel_filepos == d->rel_hdr.sh_offset && (asect->reloc_count == d->rel_hdr.sh_size / d->rel_hdr.sh_entsize)); allocated = (PTR) malloc (d->rel_hdr.sh_size); if (allocated == NULL) { bfd_set_error (bfd_error_no_memory); goto error_return; } if (bfd_seek (abfd, asect->rel_filepos, SEEK_SET) != 0 || (bfd_read (allocated, 1, d->rel_hdr.sh_size, abfd) != d->rel_hdr.sh_size)) goto error_return; native_relocs = (bfd_byte *) allocated; relents = ((arelent *) bfd_alloc (abfd, asect->reloc_count * sizeof (arelent))); if (relents == NULL) { bfd_set_error (bfd_error_no_memory); goto error_return; } entsize = d->rel_hdr.sh_entsize; BFD_ASSERT (entsize == sizeof (Elf_External_Rel) || entsize == sizeof (Elf_External_Rela)); for (i = 0, relent = relents; i < asect->reloc_count; i++, relent++, native_relocs += entsize) { Elf_Internal_Rela rela; Elf_Internal_Rel rel; if (entsize == sizeof (Elf_External_Rela)) elf_swap_reloca_in (abfd, (Elf_External_Rela *) native_relocs, &rela); else { elf_swap_reloc_in (abfd, (Elf_External_Rel *) native_relocs, &rel); rela.r_offset = rel.r_offset; rela.r_info = rel.r_info; rela.r_addend = 0; } /* The address of an ELF reloc is section relative for an object file, and absolute for an executable file or shared library. The address of a BFD reloc is always section relative. */ if ((abfd->flags & (EXEC_P | DYNAMIC)) == 0) relent->address = rela.r_offset; else relent->address = rela.r_offset - asect->vma; if (ELF_R_SYM (rela.r_info) == 0) relent->sym_ptr_ptr = bfd_abs_section_ptr->symbol_ptr_ptr; else { asymbol **ps, *s; ps = symbols + ELF_R_SYM (rela.r_info) - 1; s = *ps; /* Canonicalize ELF section symbols. FIXME: Why? */ if ((s->flags & BSF_SECTION_SYM) == 0) relent->sym_ptr_ptr = ps; else relent->sym_ptr_ptr = s->section->symbol_ptr_ptr; } relent->addend = rela.r_addend; if (entsize == sizeof (Elf_External_Rela)) (*ebd->elf_info_to_howto) (abfd, relent, &rela); else (*ebd->elf_info_to_howto_rel) (abfd, relent, &rel); } asect->relocation = relents; if (allocated != NULL) free (allocated); return true; error_return: if (allocated != NULL) free (allocated); return false; } #ifdef DEBUG static void elf_debug_section (str, num, hdr) char *str; int num; Elf_Internal_Shdr *hdr; { fprintf (stderr, "\nSection#%d '%s' 0x%.8lx\n", num, str, (long) hdr); fprintf (stderr, "sh_name = %ld\tsh_type = %ld\tsh_flags = %ld\n", (long) hdr->sh_name, (long) hdr->sh_type, (long) hdr->sh_flags); fprintf (stderr, "sh_addr = %ld\tsh_offset = %ld\tsh_size = %ld\n", (long) hdr->sh_addr, (long) hdr->sh_offset, (long) hdr->sh_size); fprintf (stderr, "sh_link = %ld\tsh_info = %ld\tsh_addralign = %ld\n", (long) hdr->sh_link, (long) hdr->sh_info, (long) hdr->sh_addralign); fprintf (stderr, "sh_entsize = %ld\n", (long) hdr->sh_entsize); fprintf (stderr, "rawdata = 0x%.8lx\n", (long) hdr->rawdata); fprintf (stderr, "contents = 0x%.8lx\n", (long) hdr->contents); fprintf (stderr, "size = %ld\n", (long) hdr->size); fflush (stderr); } static void elf_debug_file (ehdrp) Elf_Internal_Ehdr *ehdrp; { fprintf (stderr, "e_entry = 0x%.8lx\n", (long) ehdrp->e_entry); fprintf (stderr, "e_phoff = %ld\n", (long) ehdrp->e_phoff); fprintf (stderr, "e_phnum = %ld\n", (long) ehdrp->e_phnum); fprintf (stderr, "e_phentsize = %ld\n", (long) ehdrp->e_phentsize); fprintf (stderr, "e_shoff = %ld\n", (long) ehdrp->e_shoff); fprintf (stderr, "e_shnum = %ld\n", (long) ehdrp->e_shnum); fprintf (stderr, "e_shentsize = %ld\n", (long) ehdrp->e_shentsize); } #endif /* Canonicalize the relocs. */ long elf_canonicalize_reloc (abfd, section, relptr, symbols) bfd *abfd; sec_ptr section; arelent **relptr; asymbol **symbols; { arelent *tblptr; unsigned int i; if (! elf_slurp_reloc_table (abfd, section, symbols)) return -1; tblptr = section->relocation; for (i = 0; i < section->reloc_count; i++) *relptr++ = tblptr++; *relptr = NULL; return section->reloc_count; } long elf_get_symtab (abfd, alocation) bfd *abfd; asymbol **alocation; { long symcount = elf_slurp_symbol_table (abfd, alocation, false); if (symcount >= 0) bfd_get_symcount (abfd) = symcount; return symcount; } long elf_canonicalize_dynamic_symtab (abfd, alocation) bfd *abfd; asymbol **alocation; { return elf_slurp_symbol_table (abfd, alocation, true); } asymbol * elf_make_empty_symbol (abfd) bfd *abfd; { elf_symbol_type *newsym; newsym = (elf_symbol_type *) bfd_zalloc (abfd, sizeof (elf_symbol_type)); if (!newsym) { bfd_set_error (bfd_error_no_memory); return NULL; } else { newsym->symbol.the_bfd = abfd; return &newsym->symbol; } } void elf_get_symbol_info (ignore_abfd, symbol, ret) bfd *ignore_abfd; asymbol *symbol; symbol_info *ret; { bfd_symbol_info (symbol, ret); } alent * elf_get_lineno (ignore_abfd, symbol) bfd *ignore_abfd; asymbol *symbol; { fprintf (stderr, "elf_get_lineno unimplemented\n"); fflush (stderr); BFD_FAIL (); return NULL; } boolean elf_set_arch_mach (abfd, arch, machine) bfd *abfd; enum bfd_architecture arch; unsigned long machine; { /* If this isn't the right architecture for this backend, and this isn't the generic backend, fail. */ if (arch != get_elf_backend_data (abfd)->arch && arch != bfd_arch_unknown && get_elf_backend_data (abfd)->arch != bfd_arch_unknown) return false; return bfd_default_set_arch_mach (abfd, arch, machine); } boolean elf_find_nearest_line (abfd, section, symbols, offset, filename_ptr, functionname_ptr, line_ptr) bfd *abfd; asection *section; asymbol **symbols; bfd_vma offset; CONST char **filename_ptr; CONST char **functionname_ptr; unsigned int *line_ptr; { return false; } int elf_sizeof_headers (abfd, reloc) bfd *abfd; boolean reloc; { int ret; ret = sizeof (Elf_External_Ehdr); if (! reloc) ret += get_program_header_size (abfd); return ret; } boolean elf_set_section_contents (abfd, section, location, offset, count) bfd *abfd; sec_ptr section; PTR location; file_ptr offset; bfd_size_type count; { Elf_Internal_Shdr *hdr; if (! abfd->output_has_begun && ! elf_compute_section_file_positions (abfd, (struct bfd_link_info *) NULL)) return false; hdr = &elf_section_data (section)->this_hdr; if (bfd_seek (abfd, hdr->sh_offset + offset, SEEK_SET) == -1) return false; if (bfd_write (location, 1, count, abfd) != count) return false; return true; } void elf_no_info_to_howto (abfd, cache_ptr, dst) bfd *abfd; arelent *cache_ptr; Elf_Internal_Rela *dst; { fprintf (stderr, "elf RELA relocation support for target machine unimplemented\n"); fflush (stderr); BFD_FAIL (); } void elf_no_info_to_howto_rel (abfd, cache_ptr, dst) bfd *abfd; arelent *cache_ptr; Elf_Internal_Rel *dst; { fprintf (stderr, "elf REL relocation support for target machine unimplemented\n"); fflush (stderr); BFD_FAIL (); } /* Core file support */ #ifdef HAVE_PROCFS /* Some core file support requires host /proc files */ #include #else #define bfd_prstatus(abfd, descdata, descsz, filepos) true #define bfd_fpregset(abfd, descdata, descsz, filepos) true #define bfd_prpsinfo(abfd, descdata, descsz, filepos) true #endif #ifdef HAVE_PROCFS static boolean bfd_prstatus (abfd, descdata, descsz, filepos) bfd *abfd; char *descdata; int descsz; long filepos; { asection *newsect; prstatus_t *status = (prstatus_t *) 0; if (descsz == sizeof (prstatus_t)) { newsect = bfd_make_section (abfd, ".reg"); if (newsect == NULL) return false; newsect->_raw_size = sizeof (status->pr_reg); newsect->filepos = filepos + (long) &status->pr_reg; newsect->flags = SEC_HAS_CONTENTS; newsect->alignment_power = 2; if ((core_prstatus (abfd) = bfd_alloc (abfd, descsz)) != NULL) { memcpy (core_prstatus (abfd), descdata, descsz); } } return true; } /* Stash a copy of the prpsinfo structure away for future use. */ static boolean bfd_prpsinfo (abfd, descdata, descsz, filepos) bfd *abfd; char *descdata; int descsz; long filepos; { if (descsz == sizeof (prpsinfo_t)) { if ((core_prpsinfo (abfd) = bfd_alloc (abfd, descsz)) == NULL) { bfd_set_error (bfd_error_no_memory); return false; } memcpy (core_prpsinfo (abfd), descdata, descsz); } return true; } static boolean bfd_fpregset (abfd, descdata, descsz, filepos) bfd *abfd; char *descdata; int descsz; long filepos; { asection *newsect; newsect = bfd_make_section (abfd, ".reg2"); if (newsect == NULL) return false; newsect->_raw_size = descsz; newsect->filepos = filepos; newsect->flags = SEC_HAS_CONTENTS; newsect->alignment_power = 2; return true; } #endif /* HAVE_PROCFS */ /* Return a pointer to the args (including the command name) that were seen by the program that generated the core dump. Note that for some reason, a spurious space is tacked onto the end of the args in some (at least one anyway) implementations, so strip it off if it exists. */ char * elf_core_file_failing_command (abfd) bfd *abfd; { #ifdef HAVE_PROCFS if (core_prpsinfo (abfd)) { prpsinfo_t *p = core_prpsinfo (abfd); char *scan = p->pr_psargs; while (*scan++) {; } scan -= 2; if ((scan > p->pr_psargs) && (*scan == ' ')) { *scan = '\000'; } return p->pr_psargs; } #endif return NULL; } /* Return the number of the signal that caused the core dump. Presumably, since we have a core file, we got a signal of some kind, so don't bother checking the other process status fields, just return the signal number. */ int elf_core_file_failing_signal (abfd) bfd *abfd; { #ifdef HAVE_PROCFS if (core_prstatus (abfd)) { return ((prstatus_t *) (core_prstatus (abfd)))->pr_cursig; } #endif return -1; } /* Check to see if the core file could reasonably be expected to have come for the current executable file. Note that by default we return true unless we find something that indicates that there might be a problem. */ boolean elf_core_file_matches_executable_p (core_bfd, exec_bfd) bfd *core_bfd; bfd *exec_bfd; { #ifdef HAVE_PROCFS char *corename; char *execname; #endif /* First, xvecs must match since both are ELF files for the same target. */ if (core_bfd->xvec != exec_bfd->xvec) { bfd_set_error (bfd_error_system_call); return false; } #ifdef HAVE_PROCFS /* If no prpsinfo, just return true. Otherwise, grab the last component of the exec'd pathname from the prpsinfo. */ if (core_prpsinfo (core_bfd)) { corename = (((struct prpsinfo *) core_prpsinfo (core_bfd))->pr_fname); } else { return true; } /* Find the last component of the executable pathname. */ if ((execname = strrchr (exec_bfd->filename, '/')) != NULL) { execname++; } else { execname = (char *) exec_bfd->filename; } /* See if they match */ return strcmp (execname, corename) ? false : true; #else return true; #endif /* HAVE_PROCFS */ } /* ELF core files contain a segment of type PT_NOTE, that holds much of the information that would normally be available from the /proc interface for the process, at the time the process dumped core. Currently this includes copies of the prstatus, prpsinfo, and fpregset structures. Since these structures are potentially machine dependent in size and ordering, bfd provides two levels of support for them. The first level, available on all machines since it does not require that the host have /proc support or the relevant include files, is to create a bfd section for each of the prstatus, prpsinfo, and fpregset structures, without any interpretation of their contents. With just this support, the bfd client will have to interpret the structures itself. Even with /proc support, it might want these full structures for it's own reasons. In the second level of support, where HAVE_PROCFS is defined, bfd will pick apart the structures to gather some additional information that clients may want, such as the general register set, the name of the exec'ed file and its arguments, the signal (if any) that caused the core dump, etc. */ static boolean elf_corefile_note (abfd, hdr) bfd *abfd; Elf_Internal_Phdr *hdr; { Elf_External_Note *x_note_p; /* Elf note, external form */ Elf_Internal_Note i_note; /* Elf note, internal form */ char *buf = NULL; /* Entire note segment contents */ char *namedata; /* Name portion of the note */ char *descdata; /* Descriptor portion of the note */ char *sectname; /* Name to use for new section */ long filepos; /* File offset to descriptor data */ asection *newsect; if (hdr->p_filesz > 0 && (buf = (char *) malloc (hdr->p_filesz)) != NULL && bfd_seek (abfd, hdr->p_offset, SEEK_SET) != -1 && bfd_read ((PTR) buf, hdr->p_filesz, 1, abfd) == hdr->p_filesz) { x_note_p = (Elf_External_Note *) buf; while ((char *) x_note_p < (buf + hdr->p_filesz)) { i_note.namesz = bfd_h_get_32 (abfd, (bfd_byte *) x_note_p->namesz); i_note.descsz = bfd_h_get_32 (abfd, (bfd_byte *) x_note_p->descsz); i_note.type = bfd_h_get_32 (abfd, (bfd_byte *) x_note_p->type); namedata = x_note_p->name; descdata = namedata + BFD_ALIGN (i_note.namesz, 4); filepos = hdr->p_offset + (descdata - buf); switch (i_note.type) { case NT_PRSTATUS: /* process descdata as prstatus info */ if (! bfd_prstatus (abfd, descdata, i_note.descsz, filepos)) return false; sectname = ".prstatus"; break; case NT_FPREGSET: /* process descdata as fpregset info */ if (! bfd_fpregset (abfd, descdata, i_note.descsz, filepos)) return false; sectname = ".fpregset"; break; case NT_PRPSINFO: /* process descdata as prpsinfo */ if (! bfd_prpsinfo (abfd, descdata, i_note.descsz, filepos)) return false; sectname = ".prpsinfo"; break; default: /* Unknown descriptor, just ignore it. */ sectname = NULL; break; } if (sectname != NULL) { newsect = bfd_make_section (abfd, sectname); if (newsect == NULL) return false; newsect->_raw_size = i_note.descsz; newsect->filepos = filepos; newsect->flags = SEC_ALLOC | SEC_HAS_CONTENTS; newsect->alignment_power = 2; } x_note_p = (Elf_External_Note *) (descdata + BFD_ALIGN (i_note.descsz, 4)); } } if (buf != NULL) { free (buf); } else if (hdr->p_filesz > 0) { bfd_set_error (bfd_error_no_memory); return false; } return true; } /* Core files are simply standard ELF formatted files that partition the file using the execution view of the file (program header table) rather than the linking view. In fact, there is no section header table in a core file. The process status information (including the contents of the general register set) and the floating point register set are stored in a segment of type PT_NOTE. We handcraft a couple of extra bfd sections that allow standard bfd access to the general registers (.reg) and the floating point registers (.reg2). */ const bfd_target * elf_core_file_p (abfd) bfd *abfd; { Elf_External_Ehdr x_ehdr; /* Elf file header, external form */ Elf_Internal_Ehdr *i_ehdrp; /* Elf file header, internal form */ Elf_External_Phdr x_phdr; /* Program header table entry, external form */ Elf_Internal_Phdr *i_phdrp; /* Program header table, internal form */ unsigned int phindex; struct elf_backend_data *ebd; /* Read in the ELF header in external format. */ if (bfd_read ((PTR) & x_ehdr, sizeof (x_ehdr), 1, abfd) != sizeof (x_ehdr)) { if (bfd_get_error () != bfd_error_system_call) bfd_set_error (bfd_error_wrong_format); return NULL; } /* Now check to see if we have a valid ELF file, and one that BFD can make use of. The magic number must match, the address size ('class') and byte-swapping must match our XVEC entry, and it must have a program header table (FIXME: See comments re segments at top of this file). */ if (elf_file_p (&x_ehdr) == false) { wrong: bfd_set_error (bfd_error_wrong_format); return NULL; } /* FIXME, Check EI_VERSION here ! */ { #if ARCH_SIZE == 32 int desired_address_size = ELFCLASS32; #endif #if ARCH_SIZE == 64 int desired_address_size = ELFCLASS64; #endif if (x_ehdr.e_ident[EI_CLASS] != desired_address_size) goto wrong; } /* Switch xvec to match the specified byte order. */ switch (x_ehdr.e_ident[EI_DATA]) { case ELFDATA2MSB: /* Big-endian */ if (abfd->xvec->byteorder_big_p == false) goto wrong; break; case ELFDATA2LSB: /* Little-endian */ if (abfd->xvec->byteorder_big_p == true) goto wrong; break; case ELFDATANONE: /* No data encoding specified */ default: /* Unknown data encoding specified */ goto wrong; } /* Allocate an instance of the elf_obj_tdata structure and hook it up to the tdata pointer in the bfd. */ elf_tdata (abfd) = (struct elf_obj_tdata *) bfd_zalloc (abfd, sizeof (struct elf_obj_tdata)); if (elf_tdata (abfd) == NULL) { bfd_set_error (bfd_error_no_memory); return NULL; } /* FIXME, `wrong' returns from this point onward, leak memory. */ /* Now that we know the byte order, swap in the rest of the header */ i_ehdrp = elf_elfheader (abfd); elf_swap_ehdr_in (abfd, &x_ehdr, i_ehdrp); #if DEBUG & 1 elf_debug_file (i_ehdrp); #endif ebd = get_elf_backend_data (abfd); /* Check that the ELF e_machine field matches what this particular BFD format expects. */ if (ebd->elf_machine_code != i_ehdrp->e_machine) { const bfd_target * const *target_ptr; if (ebd->elf_machine_code != EM_NONE) goto wrong; /* This is the generic ELF target. Let it match any ELF target for which we do not have a specific backend. */ for (target_ptr = bfd_target_vector; *target_ptr != NULL; target_ptr++) { struct elf_backend_data *back; if ((*target_ptr)->flavour != bfd_target_elf_flavour) continue; back = (struct elf_backend_data *) (*target_ptr)->backend_data; if (back->elf_machine_code == i_ehdrp->e_machine) { /* target_ptr is an ELF backend which matches this object file, so reject the generic ELF target. */ goto wrong; } } } /* If there is no program header, or the type is not a core file, then we are hosed. */ if (i_ehdrp->e_phoff == 0 || i_ehdrp->e_type != ET_CORE) goto wrong; /* Allocate space for a copy of the program header table in internal form, seek to the program header table in the file, read it in, and convert it to internal form. As a simple sanity check, verify that the what BFD thinks is the size of each program header table entry actually matches the size recorded in the file. */ if (i_ehdrp->e_phentsize != sizeof (x_phdr)) goto wrong; i_phdrp = (Elf_Internal_Phdr *) bfd_alloc (abfd, sizeof (*i_phdrp) * i_ehdrp->e_phnum); if (!i_phdrp) { bfd_set_error (bfd_error_no_memory); return NULL; } if (bfd_seek (abfd, i_ehdrp->e_phoff, SEEK_SET) == -1) return NULL; for (phindex = 0; phindex < i_ehdrp->e_phnum; phindex++) { if (bfd_read ((PTR) & x_phdr, sizeof (x_phdr), 1, abfd) != sizeof (x_phdr)) return NULL; elf_swap_phdr_in (abfd, &x_phdr, i_phdrp + phindex); } /* Once all of the program headers have been read and converted, we can start processing them. */ for (phindex = 0; phindex < i_ehdrp->e_phnum; phindex++) { bfd_section_from_phdr (abfd, i_phdrp + phindex, phindex); if ((i_phdrp + phindex)->p_type == PT_NOTE) { if (! elf_corefile_note (abfd, i_phdrp + phindex)) return NULL; } } /* Remember the entry point specified in the ELF file header. */ bfd_get_start_address (abfd) = i_ehdrp->e_entry; return abfd->xvec; } /* ELF linker code. */ static boolean elf_link_add_object_symbols PARAMS ((bfd *, struct bfd_link_info *)); static boolean elf_link_add_archive_symbols PARAMS ((bfd *, struct bfd_link_info *)); static Elf_Internal_Rela *elf_link_read_relocs PARAMS ((bfd *, asection *, PTR, Elf_Internal_Rela *, boolean)); static boolean elf_adjust_dynamic_symbol PARAMS ((struct elf_link_hash_entry *, PTR)); /* Given an ELF BFD, add symbols to the global hash table as appropriate. */ boolean elf_bfd_link_add_symbols (abfd, info) bfd *abfd; struct bfd_link_info *info; { switch (bfd_get_format (abfd)) { case bfd_object: return elf_link_add_object_symbols (abfd, info); case bfd_archive: return elf_link_add_archive_symbols (abfd, info); default: bfd_set_error (bfd_error_wrong_format); return false; } } /* Add symbols from an ELF archive file to the linker hash table. We don't use _bfd_generic_link_add_archive_symbols because of a problem which arises on UnixWare. The UnixWare libc.so is an archive which includes an entry libc.so.1 which defines a bunch of symbols. The libc.so archive also includes a number of other object files, which also define symbols, some of which are the same as those defined in libc.so.1. Correct linking requires that we consider each object file in turn, and include it if it defines any symbols we need. _bfd_generic_link_add_archive_symbols does not do this; it looks through the list of undefined symbols, and includes any object file which defines them. When this algorithm is used on UnixWare, it winds up pulling in libc.so.1 early and defining a bunch of symbols. This means that some of the other objects in the archive are not included in the link, which is incorrect since they precede libc.so.1 in the archive. Fortunately, ELF archive handling is simpler than that done by _bfd_generic_link_add_archive_symbols, which has to allow for a.out oddities. In ELF, if we find a symbol in the archive map, and the symbol is currently undefined, we know that we must pull in that object file. Unfortunately, we do have to make multiple passes over the symbol table until nothing further is resolved. */ static boolean elf_link_add_archive_symbols (abfd, info) bfd *abfd; struct bfd_link_info *info; { symindex c; boolean *defined = NULL; boolean *included = NULL; carsym *symdefs; boolean loop; if (! bfd_has_map (abfd)) { bfd_set_error (bfd_error_no_symbols); return false; } /* Keep track of all symbols we know to be already defined, and all files we know to be already included. This is to speed up the second and subsequent passes. */ c = bfd_ardata (abfd)->symdef_count; if (c == 0) return true; defined = (boolean *) malloc (c * sizeof (boolean)); included = (boolean *) malloc (c * sizeof (boolean)); if (defined == (boolean *) NULL || included == (boolean *) NULL) { bfd_set_error (bfd_error_no_memory); goto error_return; } memset (defined, 0, c * sizeof (boolean)); memset (included, 0, c * sizeof (boolean)); symdefs = bfd_ardata (abfd)->symdefs; do { file_ptr last; symindex i; carsym *symdef; carsym *symdefend; loop = false; last = -1; symdef = symdefs; symdefend = symdef + c; for (i = 0; symdef < symdefend; symdef++, i++) { struct elf_link_hash_entry *h; bfd *element; struct bfd_link_hash_entry *undefs_tail; symindex mark; if (defined[i] || included[i]) continue; if (symdef->file_offset == last) { included[i] = true; continue; } h = elf_link_hash_lookup (elf_hash_table (info), symdef->name, false, false, false); if (h == (struct elf_link_hash_entry *) NULL) continue; if (h->root.type != bfd_link_hash_undefined) { defined[i] = true; continue; } /* We need to include this archive member. */ element = _bfd_get_elt_at_filepos (abfd, symdef->file_offset); if (element == (bfd *) NULL) goto error_return; if (! bfd_check_format (element, bfd_object)) goto error_return; /* Doublecheck that we have not included this object already--it should be impossible, but there may be something wrong with the archive. */ if (element->archive_pass != 0) { bfd_set_error (bfd_error_bad_value); goto error_return; } element->archive_pass = 1; undefs_tail = info->hash->undefs_tail; if (! (*info->callbacks->add_archive_element) (info, element, symdef->name)) goto error_return; if (! elf_link_add_object_symbols (element, info)) goto error_return; /* If there are any new undefined symbols, we need to make another pass through the archive in order to see whether they can be defined. FIXME: This isn't perfect, because common symbols wind up on undefs_tail and because an undefined symbol which is defined later on in this pass does not require another pass. This isn't a bug, but it does make the code less efficient than it could be. */ if (undefs_tail != info->hash->undefs_tail) loop = true; /* Look backward to mark all symbols from this object file which we have already seen in this pass. */ mark = i; do { included[mark] = true; if (mark == 0) break; --mark; } while (symdefs[mark].file_offset == symdef->file_offset); /* We mark subsequent symbols from this object file as we go on through the loop. */ last = symdef->file_offset; } } while (loop); free (defined); free (included); return true; error_return: if (defined != (boolean *) NULL) free (defined); if (included != (boolean *) NULL) free (included); return false; } /* Record a new dynamic symbol. We record the dynamic symbols as we read the input files, since we need to have a list of all of them before we can determine the final sizes of the output sections. */ INLINE boolean elf_link_record_dynamic_symbol (info, h) struct bfd_link_info *info; struct elf_link_hash_entry *h; { if (h->dynindx == -1) { h->dynindx = elf_hash_table (info)->dynsymcount; ++elf_hash_table (info)->dynsymcount; h->dynstr_index = bfd_add_to_strtab (elf_hash_table (info)->dynobj, elf_hash_table (info)->dynstr, h->root.root.string); if (h->dynstr_index == (unsigned long) -1) return false; } return true; } /* Add symbols from an ELF object file to the linker hash table. */ static boolean elf_link_add_object_symbols (abfd, info) bfd *abfd; struct bfd_link_info *info; { boolean (*add_symbol_hook) PARAMS ((bfd *, struct bfd_link_info *, const Elf_Internal_Sym *, const char **, flagword *, asection **, bfd_vma *)); boolean (*check_relocs) PARAMS ((bfd *, struct bfd_link_info *, asection *, const Elf_Internal_Rela *)); boolean collect; Elf_Internal_Shdr *hdr; size_t symcount; size_t extsymcount; size_t extsymoff; Elf_External_Sym *buf = NULL; struct elf_link_hash_entry **sym_hash; boolean dynamic; Elf_External_Dyn *dynbuf = NULL; struct elf_link_hash_entry *weaks; Elf_External_Sym *esym; Elf_External_Sym *esymend; add_symbol_hook = get_elf_backend_data (abfd)->elf_add_symbol_hook; collect = get_elf_backend_data (abfd)->collect; /* A stripped shared library might only have a dynamic symbol table, not a regular symbol table. In that case we can still go ahead and link using the dynamic symbol table. */ if (elf_onesymtab (abfd) == 0 && elf_dynsymtab (abfd) != 0) { elf_onesymtab (abfd) = elf_dynsymtab (abfd); elf_tdata (abfd)->symtab_hdr = elf_tdata (abfd)->dynsymtab_hdr; } hdr = &elf_tdata (abfd)->symtab_hdr; symcount = hdr->sh_size / sizeof (Elf_External_Sym); /* The sh_info field of the symtab header tells us where the external symbols start. We don't care about the local symbols at this point. */ if (elf_bad_symtab (abfd)) { extsymcount = symcount; extsymoff = 0; } else { extsymcount = symcount - hdr->sh_info; extsymoff = hdr->sh_info; } buf = (Elf_External_Sym *) malloc (extsymcount * sizeof (Elf_External_Sym)); if (buf == NULL && extsymcount != 0) { bfd_set_error (bfd_error_no_memory); goto error_return; } /* We store a pointer to the hash table entry for each external symbol. */ sym_hash = ((struct elf_link_hash_entry **) bfd_alloc (abfd, extsymcount * sizeof (struct elf_link_hash_entry *))); if (sym_hash == NULL) { bfd_set_error (bfd_error_no_memory); goto error_return; } elf_sym_hashes (abfd) = sym_hash; if (elf_elfheader (abfd)->e_type != ET_DYN) { dynamic = false; /* If we are creating a shared library, create all the dynamic sections immediately. We need to attach them to something, so we attach them to this BFD, provided it is the right format. FIXME: If there are no input BFD's of the same format as the output, we can't make a shared library. */ if (info->shared && elf_hash_table (info)->dynobj == NULL && abfd->xvec == info->hash->creator) { if (! elf_link_create_dynamic_sections (abfd, info)) goto error_return; elf_hash_table (info)->dynobj = abfd; } } else { asection *s; const char *name; unsigned long strindex; dynamic = true; /* You can't use -r against a dynamic object. Also, there's no hope of using a dynamic object which does not exactly match the format of the output file. */ if (info->relocateable || info->hash->creator != abfd->xvec) { bfd_set_error (bfd_error_invalid_operation); goto error_return; } /* Find the name to use in a DT_NEEDED entry that refers to this object. If the object has a DT_SONAME entry, we use it. Otherwise, if the generic linker stuck something in elf_dt_needed_name, we use that. Otherwise, we just use the file name. */ name = bfd_get_filename (abfd); if (elf_dt_needed_name (abfd) != NULL) name = elf_dt_needed_name (abfd); s = bfd_get_section_by_name (abfd, ".dynamic"); if (s != NULL) { Elf_External_Dyn *extdyn; Elf_External_Dyn *extdynend; dynbuf = (Elf_External_Dyn *) malloc (s->_raw_size); if (dynbuf == NULL) { bfd_set_error (bfd_error_no_memory); goto error_return; } if (! bfd_get_section_contents (abfd, s, (PTR) dynbuf, (file_ptr) 0, s->_raw_size)) goto error_return; extdyn = dynbuf; extdynend = extdyn + s->_raw_size / sizeof (Elf_External_Dyn); for (; extdyn < extdynend; extdyn++) { Elf_Internal_Dyn dyn; elf_swap_dyn_in (abfd, extdyn, &dyn); if (dyn.d_tag == DT_SONAME) { int elfsec; unsigned long link; elfsec = elf_section_from_bfd_section (abfd, s); if (elfsec == -1) goto error_return; link = elf_elfsections (abfd)[elfsec]->sh_link; name = elf_string_from_elf_section (abfd, link, dyn.d_un.d_val); if (name == NULL) goto error_return; break; } } free (dynbuf); dynbuf = NULL; } /* We do not want to include any of the sections in a dynamic object in the output file. We hack by simply clobbering the list of sections in the BFD. This could be handled more cleanly by, say, a new section flag; the existing SEC_NEVER_LOAD flag is not the one we want, because that one still implies that the section takes up space in the output file. */ abfd->sections = NULL; /* If this is the first dynamic object found in the link, create the special sections required for dynamic linking. We need to put them somewhere, and attaching them to the first dynamic object is as good place as any. */ if (elf_hash_table (info)->dynobj == NULL) { if (! elf_link_create_dynamic_sections (abfd, info)) goto error_return; elf_hash_table (info)->dynobj = abfd; } /* Add a DT_NEEDED entry for this dynamic object. */ strindex = bfd_add_to_strtab (abfd, elf_hash_table (info)->dynstr, name); if (strindex == (unsigned long) -1) goto error_return; if (! elf_add_dynamic_entry (info, DT_NEEDED, strindex)) goto error_return; } if (bfd_seek (abfd, hdr->sh_offset + extsymoff * sizeof (Elf_External_Sym), SEEK_SET) != 0 || (bfd_read ((PTR) buf, sizeof (Elf_External_Sym), extsymcount, abfd) != extsymcount * sizeof (Elf_External_Sym))) goto error_return; weaks = NULL; esymend = buf + extsymcount; for (esym = buf; esym < esymend; esym++, sym_hash++) { Elf_Internal_Sym sym; int bind; bfd_vma value; asection *sec; flagword flags; const char *name; struct elf_link_hash_entry *h = NULL; boolean definition; elf_swap_symbol_in (abfd, esym, &sym); flags = BSF_NO_FLAGS; sec = NULL; value = sym.st_value; *sym_hash = NULL; bind = ELF_ST_BIND (sym.st_info); if (bind == STB_LOCAL) { /* This should be impossible, since ELF requires that all global symbols follow all local symbols, and that sh_info point to the first global symbol. Unfortunatealy, Irix 5 screws this up. */ continue; } else if (bind == STB_GLOBAL) flags = BSF_GLOBAL; else if (bind == STB_WEAK) flags = BSF_WEAK; else { /* Leave it up to the processor backend. */ } if (sym.st_shndx == SHN_UNDEF) sec = bfd_und_section_ptr; else if (sym.st_shndx > 0 && sym.st_shndx < SHN_LORESERVE) { sec = section_from_elf_index (abfd, sym.st_shndx); if (sec == NULL) goto error_return; value -= sec->vma; } else if (sym.st_shndx == SHN_ABS) sec = bfd_abs_section_ptr; else if (sym.st_shndx == SHN_COMMON) { sec = bfd_com_section_ptr; /* What ELF calls the size we call the value. What ELF calls the value we call the alignment. */ value = sym.st_size; } else { /* Leave it up to the processor backend. */ } name = elf_string_from_elf_section (abfd, hdr->sh_link, sym.st_name); if (name == (const char *) NULL) goto error_return; if (add_symbol_hook) { if (! (*add_symbol_hook) (abfd, info, &sym, &name, &flags, &sec, &value)) goto error_return; /* The hook function sets the name to NULL if this symbol should be skipped for some reason. */ if (name == (const char *) NULL) continue; } /* Sanity check that all possibilities were handled. */ if (flags == BSF_NO_FLAGS || sec == (asection *) NULL) { bfd_set_error (bfd_error_bad_value); goto error_return; } if (bfd_is_und_section (sec) || bfd_is_com_section (sec)) definition = false; else definition = true; if (info->hash->creator->flavour == bfd_target_elf_flavour) { /* We need to look up the symbol now in order to get some of the dynamic object handling right. We pass the hash table entry in to _bfd_generic_link_add_one_symbol so that it does not have to look it up again. */ h = elf_link_hash_lookup (elf_hash_table (info), name, true, false, false); if (h == NULL) goto error_return; *sym_hash = h; /* If we are looking at a dynamic object, and this is a definition, we need to see if it has already been defined by some other object. If it has, we want to use the existing definition, and we do not want to report a multiple symbol definition error; we do this by clobbering sec to be bfd_und_section_ptr. */ if (dynamic && definition) { if (h->root.type == bfd_link_hash_defined) sec = bfd_und_section_ptr; } /* Similarly, if we are not looking at a dynamic object, and we have a definition, we want to override any definition we may have from a dynamic object. Symbols from regular files always take precedence over symbols from dynamic objects, even if they are defined after the dynamic object in the link. */ if (! dynamic && definition && h->root.type == bfd_link_hash_defined && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0 && (bfd_get_flavour (h->root.u.def.section->owner) == bfd_target_elf_flavour) && (elf_elfheader (h->root.u.def.section->owner)->e_type == ET_DYN)) { /* Change the hash table entry to undefined, and let _bfd_generic_link_add_one_symbol do the right thing with the new definition. */ h->root.type = bfd_link_hash_undefined; h->root.u.undef.abfd = h->root.u.def.section->owner; h->elf_link_hash_flags &=~ ELF_LINK_HASH_DEFINED_WEAK; } /* If this is a weak definition which we are going to use, and the symbol is currently undefined, record that the definition is weak. */ if (definition && (flags & BSF_WEAK) != 0 && ! bfd_is_und_section (sec) && (h->root.type == bfd_link_hash_new || h->root.type == bfd_link_hash_undefined || h->root.type == bfd_link_hash_weak)) h->elf_link_hash_flags |= ELF_LINK_HASH_DEFINED_WEAK; } if (! (_bfd_generic_link_add_one_symbol (info, abfd, name, flags, sec, value, (const char *) NULL, false, collect, (struct bfd_link_hash_entry **) sym_hash))) goto error_return; if (dynamic && definition && (flags & BSF_WEAK) != 0 && ELF_ST_TYPE (sym.st_info) != STT_FUNC && (*sym_hash)->weakdef == NULL) { /* Keep a list of all weak defined non function symbols from a dynamic object, using the weakdef field. Later in this function we will set the weakdef field to the correct value. We only put non-function symbols from dynamic objects on this list, because that happens to be the only time we need to know the normal symbol corresponding to a weak symbol, and the information is time consuming to figure out. If the weakdef field is not already NULL, then this symbol was already defined by some previous dynamic object, and we will be using that previous definition anyhow. */ (*sym_hash)->weakdef = weaks; weaks = *sym_hash; } /* Get the alignment of a common symbol. */ if (sym.st_shndx == SHN_COMMON && h->root.type == bfd_link_hash_common) h->root.u.c.alignment_power = bfd_log2 (sym.st_value); if (info->hash->creator->flavour == bfd_target_elf_flavour) { int old_flags; boolean dynsym; int new_flag; /* Remember the symbol size and type. */ if (sym.st_size != 0) { /* FIXME: We should probably somehow give a warning if the symbol size changes. */ h->size = sym.st_size; } if (ELF_ST_TYPE (sym.st_info) != STT_NOTYPE) { /* FIXME: We should probably somehow give a warning if the symbol type changes. */ h->type = ELF_ST_TYPE (sym.st_info); } /* Set a flag in the hash table entry indicating the type of reference or definition we just found. Keep a count of the number of dynamic symbols we find. A dynamic symbol is one which is referenced or defined by both a regular object and a shared object, or one which is referenced or defined by more than one shared object. */ old_flags = h->elf_link_hash_flags; dynsym = false; if (! dynamic) { if (! definition) new_flag = ELF_LINK_HASH_REF_REGULAR; else new_flag = ELF_LINK_HASH_DEF_REGULAR; if (info->shared || (old_flags & (ELF_LINK_HASH_DEF_DYNAMIC | ELF_LINK_HASH_REF_DYNAMIC)) != 0) dynsym = true; } else { if (! definition) new_flag = ELF_LINK_HASH_REF_DYNAMIC; else new_flag = ELF_LINK_HASH_DEF_DYNAMIC; if ((old_flags & new_flag) != 0 || (old_flags & (ELF_LINK_HASH_DEF_REGULAR | ELF_LINK_HASH_REF_REGULAR)) != 0) dynsym = true; } h->elf_link_hash_flags |= new_flag; if (dynsym && h->dynindx == -1) { if (! elf_link_record_dynamic_symbol (info, h)) goto error_return; } } } /* Now set the weakdefs field correctly for all the weak defined symbols we found. The only way to do this is to search all the symbols. Since we only need the information for non functions in dynamic objects, that's the only time we actually put anything on the list WEAKS. We need this information so that if a regular object refers to a symbol defined weakly in a dynamic object, the real symbol in the dynamic object is also put in the dynamic symbols; we also must arrange for both symbols to point to the same memory location. We could handle the general case of symbol aliasing, but a general symbol alias can only be generated in assembler code, handling it correctly would be very time consuming, and other ELF linkers don't handle general aliasing either. */ while (weaks != NULL) { struct elf_link_hash_entry *hlook; asection *slook; bfd_vma vlook; struct elf_link_hash_entry **hpp; struct elf_link_hash_entry **hppend; hlook = weaks; weaks = hlook->weakdef; hlook->weakdef = NULL; BFD_ASSERT (hlook->root.type == bfd_link_hash_defined); slook = hlook->root.u.def.section; vlook = hlook->root.u.def.value; hpp = elf_sym_hashes (abfd); hppend = hpp + extsymcount; for (; hpp < hppend; hpp++) { struct elf_link_hash_entry *h; h = *hpp; if (h != hlook && h->root.type == bfd_link_hash_defined && h->root.u.def.section == slook && h->root.u.def.value == vlook) { hlook->weakdef = h; /* If the weak definition is in the list of dynamic symbols, make sure the real definition is put there as well. */ if (hlook->dynindx != -1 && h->dynindx == -1) { if (! elf_link_record_dynamic_symbol (info, h)) goto error_return; } break; } } } if (buf != NULL) { free (buf); buf = NULL; } /* If this object is the same format as the output object, and it is not a shared library, then let the backend look through the relocs. This is required to build global offset table entries and to arrange for dynamic relocs. It is not required for the particular common case of linking non PIC code, even when linking against shared libraries, but unfortunately there is no way of knowing whether an object file has been compiled PIC or not. Looking through the relocs is not particularly time consuming. The problem is that we must either (1) keep the relocs in memory, which causes the linker to require additional runtime memory or (2) read the relocs twice from the input file, which wastes time. This would be a good case for using mmap. I have no idea how to handle linking PIC code into a file of a different format. It probably can't be done. */ check_relocs = get_elf_backend_data (abfd)->check_relocs; if (! dynamic && abfd->xvec == info->hash->creator && check_relocs != NULL) { asection *o; for (o = abfd->sections; o != NULL; o = o->next) { Elf_Internal_Rela *internal_relocs; boolean ok; if ((o->flags & SEC_RELOC) == 0 || o->reloc_count == 0) continue; /* I believe we can ignore the relocs for any section which does not form part of the final process image, such as a debugging section. */ if ((o->flags & SEC_ALLOC) == 0) continue; internal_relocs = elf_link_read_relocs (abfd, o, (PTR) NULL, (Elf_Internal_Rela *) NULL, info->keep_memory); if (internal_relocs == NULL) goto error_return; ok = (*check_relocs) (abfd, info, o, internal_relocs); if (! info->keep_memory) free (internal_relocs); if (! ok) goto error_return; } } return true; error_return: if (buf != NULL) free (buf); if (dynbuf != NULL) free (dynbuf); return false; } /* Create some sections which will be filled in with dynamic linking information. The ABFD argument is an input file which is a dynamic object. The dynamic sections take up virtual memory space when the final executable is run, so we need to create them before addresses are assigned to the output sections. We work out the actual contents and size of these sections later. */ boolean elf_link_create_dynamic_sections (abfd, info) bfd *abfd; struct bfd_link_info *info; { flagword flags; register asection *s; struct elf_link_hash_entry *h; struct elf_backend_data *bed; /* Note that we set the SEC_IN_MEMORY flag for all of these sections. */ flags = SEC_ALLOC | SEC_LOAD | SEC_HAS_CONTENTS | SEC_IN_MEMORY; /* A dynamically linked executable has a .interp section, but a shared library does not. */ if (! info->shared) { s = bfd_make_section (abfd, ".interp"); if (s == NULL || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY)) return false; } s = bfd_make_section (abfd, ".dynsym"); if (s == NULL || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY) || ! bfd_set_section_alignment (abfd, s, LOG_FILE_ALIGN)) return false; /* The first .dynsym symbol is a dummy. */ elf_hash_table (info)->dynsymcount = 1; s = bfd_make_section (abfd, ".dynstr"); if (s == NULL || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY)) return false; /* Create a strtab to hold the dynamic symbol names. */ elf_hash_table (info)->dynstr = bfd_new_strtab (abfd); if (elf_hash_table (info)->dynstr == NULL) return false; s = bfd_make_section (abfd, ".dynamic"); if (s == NULL || ! bfd_set_section_flags (abfd, s, flags) || ! bfd_set_section_alignment (abfd, s, LOG_FILE_ALIGN)) return false; /* The special symbol _DYNAMIC is always set to the start of the .dynamic section. This call occurs before we have processed the symbols for any dynamic object, so we don't have to worry about overriding a dynamic definition. We could set _DYNAMIC in a linker script, but we only want to define it if we are, in fact, creating a .dynamic section. We don't want to define it if there is no .dynamic section, since on some ELF platforms the start up code examines it to decide how to initialize the process. */ h = NULL; if (! (_bfd_generic_link_add_one_symbol (info, abfd, "_DYNAMIC", BSF_GLOBAL, s, (bfd_vma) 0, (const char *) NULL, false, get_elf_backend_data (abfd)->collect, (struct bfd_link_hash_entry **) &h))) return false; h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR; h->type = STT_OBJECT; if (info->shared && ! elf_link_record_dynamic_symbol (info, h)) return false; s = bfd_make_section (abfd, ".hash"); if (s == NULL || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY) || ! bfd_set_section_alignment (abfd, s, LOG_FILE_ALIGN)) return false; /* Let the backend create the rest of the sections. This lets the backend set the right flags. The backend will normally create the .got and .plt sections. */ bed = get_elf_backend_data (abfd); return (*bed->elf_backend_create_dynamic_sections) (abfd, info); } /* Add an entry to the .dynamic table. */ boolean elf_add_dynamic_entry (info, tag, val) struct bfd_link_info *info; bfd_vma tag; bfd_vma val; { Elf_Internal_Dyn dyn; bfd *dynobj; asection *s; size_t newsize; bfd_byte *newcontents; dynobj = elf_hash_table (info)->dynobj; s = bfd_get_section_by_name (dynobj, ".dynamic"); BFD_ASSERT (s != NULL); newsize = s->_raw_size + sizeof (Elf_External_Dyn); if (s->contents == NULL) newcontents = (bfd_byte *) malloc (newsize); else newcontents = (bfd_byte *) realloc (s->contents, newsize); if (newcontents == NULL) { bfd_set_error (bfd_error_no_memory); return false; } dyn.d_tag = tag; dyn.d_un.d_val = val; elf_swap_dyn_out (dynobj, &dyn, (Elf_External_Dyn *) (newcontents + s->_raw_size)); s->_raw_size = newsize; s->contents = newcontents; return true; } /* Read and swap the relocs for a section. They may have been cached. If the EXTERNAL_RELOCS and INTERNAL_RELOCS arguments are not NULL, they are used as buffers to read into. They are known to be large enough. If the INTERNAL_RELOCS relocs argument is NULL, the return value is allocated using either malloc or bfd_alloc, according to the KEEP_MEMORY argument. */ static Elf_Internal_Rela * elf_link_read_relocs (abfd, o, external_relocs, internal_relocs, keep_memory) bfd *abfd; asection *o; PTR external_relocs; Elf_Internal_Rela *internal_relocs; boolean keep_memory; { Elf_Internal_Shdr *rel_hdr; PTR alloc1 = NULL; Elf_Internal_Rela *alloc2 = NULL; if (elf_section_data (o)->relocs != NULL) return elf_section_data (o)->relocs; if (o->reloc_count == 0) return NULL; rel_hdr = &elf_section_data (o)->rel_hdr; if (internal_relocs == NULL) { size_t size; size = o->reloc_count * sizeof (Elf_Internal_Rela); if (keep_memory) internal_relocs = (Elf_Internal_Rela *) bfd_alloc (abfd, size); else internal_relocs = alloc2 = (Elf_Internal_Rela *) malloc (size); if (internal_relocs == NULL) { bfd_set_error (bfd_error_no_memory); goto error_return; } } if (external_relocs == NULL) { alloc1 = (PTR) malloc (rel_hdr->sh_size); if (alloc1 == NULL) { bfd_set_error (bfd_error_no_memory); goto error_return; } external_relocs = alloc1; } if ((bfd_seek (abfd, rel_hdr->sh_offset, SEEK_SET) != 0) || (bfd_read (external_relocs, 1, rel_hdr->sh_size, abfd) != rel_hdr->sh_size)) goto error_return; /* Swap in the relocs. For convenience, we always produce an Elf_Internal_Rela array; if the relocs are Rel, we set the addend to 0. */ if (rel_hdr->sh_entsize == sizeof (Elf_External_Rel)) { Elf_External_Rel *erel; Elf_External_Rel *erelend; Elf_Internal_Rela *irela; erel = (Elf_External_Rel *) external_relocs; erelend = erel + o->reloc_count; irela = internal_relocs; for (; erel < erelend; erel++, irela++) { Elf_Internal_Rel irel; elf_swap_reloc_in (abfd, erel, &irel); irela->r_offset = irel.r_offset; irela->r_info = irel.r_info; irela->r_addend = 0; } } else { Elf_External_Rela *erela; Elf_External_Rela *erelaend; Elf_Internal_Rela *irela; BFD_ASSERT (rel_hdr->sh_entsize == sizeof (Elf_External_Rela)); erela = (Elf_External_Rela *) external_relocs; erelaend = erela + o->reloc_count; irela = internal_relocs; for (; erela < erelaend; erela++, irela++) elf_swap_reloca_in (abfd, erela, irela); } /* Cache the results for next time, if we can. */ if (keep_memory) elf_section_data (o)->relocs = internal_relocs; if (alloc1 != NULL) free (alloc1); /* Don't free alloc2, since if it was allocated we are passing it back (under the name of internal_relocs). */ return internal_relocs; error_return: if (alloc1 != NULL) free (alloc1); if (alloc2 != NULL) free (alloc2); return NULL; } /* Record an assignment to a symbol made by a linker script. We need this in case some dynamic object refers to this symbol. */ /*ARGSUSED*/ boolean NAME(bfd_elf,record_link_assignment) (output_bfd, info, name) bfd *output_bfd; struct bfd_link_info *info; const char *name; { struct elf_link_hash_entry *h; h = elf_link_hash_lookup (elf_hash_table (info), name, true, true, false); if (h == NULL) return false; h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR; h->type = STT_OBJECT; if (((h->elf_link_hash_flags & (ELF_LINK_HASH_DEF_DYNAMIC | ELF_LINK_HASH_REF_DYNAMIC)) != 0 || info->shared) && h->dynindx == -1) { if (! elf_link_record_dynamic_symbol (info, h)) return false; /* If this is a weak defined symbol, and we know a corresponding real symbol from the same dynamic object, make sure the real symbol is also made into a dynamic symbol. */ if (h->weakdef != NULL && h->weakdef->dynindx == -1) { if (! elf_link_record_dynamic_symbol (info, h->weakdef)) return false; } } return true; } /* Array used to determine the number of hash table buckets to use based on the number of symbols there are. If there are fewer than 3 symbols we use 1 bucket, fewer than 17 symbols we use 3 buckets, fewer than 37 we use 17 buckets, and so forth. We never use more than 521 buckets. */ static const size_t elf_buckets[] = { 1, 3, 17, 37, 67, 97, 131, 197, 263, 521, 0 }; /* Set up the sizes and contents of the ELF dynamic sections. This is called by the ELF linker emulation before_allocation routine. We must set the sizes of the sections before the linker sets the addresses of the various sections. */ boolean NAME(bfd_elf,size_dynamic_sections) (output_bfd, soname, rpath, info, sinterpptr) bfd *output_bfd; const char *soname; const char *rpath; struct bfd_link_info *info; asection **sinterpptr; { bfd *dynobj; size_t dynsymcount; asection *s; Elf_Internal_Sym isym; size_t i; size_t bucketcount; struct elf_backend_data *bed; *sinterpptr = NULL; dynobj = elf_hash_table (info)->dynobj; dynsymcount = elf_hash_table (info)->dynsymcount; /* If there were no dynamic objects in the link, there is nothing to do here. */ if (dynobj == NULL) return true; *sinterpptr = bfd_get_section_by_name (dynobj, ".interp"); BFD_ASSERT (*sinterpptr != NULL || info->shared); /* Set the size of the .dynsym and .hash sections. We counted the number of dynamic symbols in elf_link_add_object_symbols. We will build the contents of .dynsym and .hash when we build the final symbol table, because until then we do not know the correct value to give the symbols. We built the .dynstr section as we went along in elf_link_add_object_symbols. */ s = bfd_get_section_by_name (dynobj, ".dynsym"); BFD_ASSERT (s != NULL); s->_raw_size = dynsymcount * sizeof (Elf_External_Sym); s->contents = (bfd_byte *) bfd_alloc (output_bfd, s->_raw_size); if (s->contents == NULL && s->_raw_size != 0) { bfd_set_error (bfd_error_no_memory); return false; } /* The first entry in .dynsym is a dummy symbol. */ isym.st_value = 0; isym.st_size = 0; isym.st_name = 0; isym.st_info = 0; isym.st_other = 0; isym.st_shndx = 0; elf_swap_symbol_out (output_bfd, &isym, (Elf_External_Sym *) s->contents); for (i = 0; elf_buckets[i] != 0; i++) { bucketcount = elf_buckets[i]; if (dynsymcount < elf_buckets[i + 1]) break; } s = bfd_get_section_by_name (dynobj, ".hash"); BFD_ASSERT (s != NULL); s->_raw_size = (2 + bucketcount + dynsymcount) * (ARCH_SIZE / 8); s->contents = (bfd_byte *) bfd_alloc (output_bfd, s->_raw_size); if (s->contents == NULL) { bfd_set_error (bfd_error_no_memory); return false; } memset (s->contents, 0, s->_raw_size); put_word (output_bfd, bucketcount, s->contents); put_word (output_bfd, dynsymcount, s->contents + (ARCH_SIZE / 8)); elf_hash_table (info)->bucketcount = bucketcount; if (soname != NULL) { unsigned long indx; indx = bfd_add_to_strtab (dynobj, elf_hash_table (info)->dynstr, soname); if (indx == (unsigned long) -1 || ! elf_add_dynamic_entry (info, DT_SONAME, indx)) return false; } if (rpath != NULL) { unsigned long indx; indx = bfd_add_to_strtab (dynobj, elf_hash_table (info)->dynstr, rpath); if (indx == (unsigned long) -1 || ! elf_add_dynamic_entry (info, DT_RPATH, indx)) return false; } s = bfd_get_section_by_name (dynobj, ".dynstr"); BFD_ASSERT (s != NULL); s->_raw_size = elf_hash_table (info)->dynstr->length; s->contents = (unsigned char *) elf_hash_table (info)->dynstr->tab; /* Find all symbols which were defined in a dynamic object and make the backend pick a reasonable value for them. */ elf_link_hash_traverse (elf_hash_table (info), elf_adjust_dynamic_symbol, (PTR) info); /* Add some entries to the .dynamic section. We fill in some of the values later, in elf_bfd_final_link, but we must add the entries now so that we know the final size of the .dynamic section. */ if (bfd_get_section_by_name (output_bfd, ".init") != NULL) { if (! elf_add_dynamic_entry (info, DT_INIT, 0)) return false; } if (bfd_get_section_by_name (output_bfd, ".fini") != NULL) { if (! elf_add_dynamic_entry (info, DT_FINI, 0)) return false; } if (! elf_add_dynamic_entry (info, DT_HASH, 0) || ! elf_add_dynamic_entry (info, DT_STRTAB, 0) || ! elf_add_dynamic_entry (info, DT_SYMTAB, 0) || ! elf_add_dynamic_entry (info, DT_STRSZ, elf_hash_table (info)->dynstr->length) || ! elf_add_dynamic_entry (info, DT_SYMENT, sizeof (Elf_External_Sym))) return false; /* The backend must work out the sizes of all the other dynamic sections. */ bed = get_elf_backend_data (output_bfd); if (! (*bed->elf_backend_size_dynamic_sections) (output_bfd, info)) return false; return elf_add_dynamic_entry (info, DT_NULL, 0); } /* Make the backend pick a good value for a dynamic symbol. This is called via elf_link_hash_traverse, and also calls itself recursively. */ static boolean elf_adjust_dynamic_symbol (h, data) struct elf_link_hash_entry *h; PTR data; { struct bfd_link_info *info = (struct bfd_link_info *) data; bfd *dynobj; struct elf_backend_data *bed; /* If this symbol is not defined by a dynamic object, or is not referenced by a regular object, ignore it. FIXME: Do we need to worry about symbols which are defined by one dynamic object and referenced by another one? */ if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0 || (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) == 0 || (h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR) == 0) return true; /* If we've already adjusted this symbol, don't do it again. This can happen via a recursive call. */ if ((h->elf_link_hash_flags & ELF_LINK_HASH_DYNAMIC_ADJUSTED) != 0) return true; /* Don't look at this symbol again. Note that we must set this after checking the above conditions, because we may look at a symbol once, decide not to do anything, and then get called recursively later after REF_REGULAR is set below. */ h->elf_link_hash_flags |= ELF_LINK_HASH_DYNAMIC_ADJUSTED; /* If this is a weak definition, and we know a real definition, and the real symbol is not itself defined by a regular object file, then get a good value for the real definition. We handle the real symbol first, for the convenience of the backend routine. Note that there is a confusing case here. If the real definition is defined by a regular object file, we don't get the real symbol from the dynamic object, but we do get the weak symbol. If the processor backend uses a COPY reloc, then if some routine in the dynamic object changes the real symbol, we will not see that change in the corresponding weak symbol. This is the way other ELF linkers work as well, and seems to be a result of the shared library model. I will clarify this issue. Most SVR4 shared libraries define the variable _timezone and define timezone as a weak synonym. The tzset call changes _timezone. If you write extern int timezone; int _timezone = 5; int main () { tzset (); printf ("%d %d\n", timezone, _timezone); } you might expect that, since timezone is a synonym for _timezone, the same number will print both times. However, if the processor backend uses a COPY reloc, then actually timezone will be copied into your process image, and, since you define _timezone yourself, _timezone will not. Thus timezone and _timezone will wind up at different memory locations. The tzset call will set _timezone, leaving timezone unchanged. */ if (h->weakdef != NULL) { struct elf_link_hash_entry *weakdef; BFD_ASSERT (h->root.type == bfd_link_hash_defined); weakdef = h->weakdef; BFD_ASSERT (weakdef->root.type == bfd_link_hash_defined); BFD_ASSERT (weakdef->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC); if ((weakdef->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0) { /* This symbol is defined by a regular object file, so we will not do anything special. Clear weakdef for the convenience of the processor backend. */ h->weakdef = NULL; } else { /* There is an implicit reference by a regular object file via the weak symbol. */ weakdef->elf_link_hash_flags |= ELF_LINK_HASH_REF_REGULAR; if (! elf_adjust_dynamic_symbol (weakdef, (PTR) info)) return false; } } dynobj = elf_hash_table (info)->dynobj; bed = get_elf_backend_data (dynobj); if (! (*bed->elf_backend_adjust_dynamic_symbol) (info, h)) { /* FIXME: No way to return error. */ abort (); } return true; } /* Final phase of ELF linker. */ /* A structure we use to avoid passing large numbers of arguments. */ struct elf_final_link_info { /* General link information. */ struct bfd_link_info *info; /* Output BFD. */ bfd *output_bfd; /* Symbol string table. */ struct strtab *symstrtab; /* .dynsym section. */ asection *dynsym_sec; /* .hash section. */ asection *hash_sec; /* Buffer large enough to hold contents of any section. */ bfd_byte *contents; /* Buffer large enough to hold external relocs of any section. */ PTR external_relocs; /* Buffer large enough to hold internal relocs of any section. */ Elf_Internal_Rela *internal_relocs; /* Buffer large enough to hold external local symbols of any input BFD. */ Elf_External_Sym *external_syms; /* Buffer large enough to hold internal local symbols of any input BFD. */ Elf_Internal_Sym *internal_syms; /* Array large enough to hold a symbol index for each local symbol of any input BFD. */ long *indices; /* Array large enough to hold a section pointer for each local symbol of any input BFD. */ asection **sections; /* Buffer to hold swapped out symbols. */ Elf_External_Sym *symbuf; /* Number of swapped out symbols in buffer. */ size_t symbuf_count; /* Number of symbols which fit in symbuf. */ size_t symbuf_size; }; static boolean elf_link_output_sym PARAMS ((struct elf_final_link_info *, const char *, Elf_Internal_Sym *, asection *)); static boolean elf_link_flush_output_syms PARAMS ((struct elf_final_link_info *)); static boolean elf_link_output_extsym PARAMS ((struct elf_link_hash_entry *, PTR)); static boolean elf_link_input_bfd PARAMS ((struct elf_final_link_info *, bfd *)); static boolean elf_reloc_link_order PARAMS ((bfd *, struct bfd_link_info *, asection *, struct bfd_link_order *)); /* Do the final step of an ELF link. */ boolean elf_bfd_final_link (abfd, info) bfd *abfd; struct bfd_link_info *info; { bfd *dynobj; struct elf_final_link_info finfo; register asection *o; register struct bfd_link_order *p; register bfd *sub; size_t max_contents_size; size_t max_external_reloc_size; size_t max_internal_reloc_count; size_t max_sym_count; file_ptr off; Elf_Internal_Sym elfsym; unsigned int i; Elf_Internal_Shdr *symtab_hdr; Elf_Internal_Shdr *symstrtab_hdr; struct elf_backend_data *bed = get_elf_backend_data (abfd); if (info->shared) abfd->flags |= DYNAMIC; dynobj = elf_hash_table (info)->dynobj; finfo.info = info; finfo.output_bfd = abfd; finfo.symstrtab = bfd_new_strtab (abfd); if (finfo.symstrtab == NULL) return false; if (dynobj == NULL) { finfo.dynsym_sec = NULL; finfo.hash_sec = NULL; } else { finfo.dynsym_sec = bfd_get_section_by_name (dynobj, ".dynsym"); finfo.hash_sec = bfd_get_section_by_name (dynobj, ".hash"); if (finfo.dynsym_sec == NULL || finfo.hash_sec == NULL) abort (); } finfo.contents = NULL; finfo.external_relocs = NULL; finfo.internal_relocs = NULL; finfo.external_syms = NULL; finfo.internal_syms = NULL; finfo.indices = NULL; finfo.sections = NULL; finfo.symbuf = NULL; finfo.symbuf_count = 0; /* Count up the number of relocations we will output for each output section, so that we know the sizes of the reloc sections. We also figure out some maximum sizes. */ max_contents_size = 0; max_external_reloc_size = 0; max_internal_reloc_count = 0; max_sym_count = 0; for (o = abfd->sections; o != (asection *) NULL; o = o->next) { o->reloc_count = 0; for (p = o->link_order_head; p != NULL; p = p->next) { if (p->type == bfd_section_reloc_link_order || p->type == bfd_symbol_reloc_link_order) ++o->reloc_count; else if (p->type == bfd_indirect_link_order) { asection *sec; sec = p->u.indirect.section; if (info->relocateable) o->reloc_count += sec->reloc_count; if (sec->_raw_size > max_contents_size) max_contents_size = sec->_raw_size; if (sec->_cooked_size > max_contents_size) max_contents_size = sec->_cooked_size; /* We are interested in just local symbols, not all symbols. */ if (bfd_get_flavour (sec->owner) == bfd_target_elf_flavour) { size_t sym_count; if (elf_bad_symtab (sec->owner)) sym_count = (elf_tdata (sec->owner)->symtab_hdr.sh_size / sizeof (Elf_External_Sym)); else sym_count = elf_tdata (sec->owner)->symtab_hdr.sh_info; if (sym_count > max_sym_count) max_sym_count = sym_count; if ((sec->flags & SEC_RELOC) != 0) { size_t ext_size; ext_size = elf_section_data (sec)->rel_hdr.sh_size; if (ext_size > max_external_reloc_size) max_external_reloc_size = ext_size; if (sec->reloc_count > max_internal_reloc_count) max_internal_reloc_count = sec->reloc_count; } } } } if (o->reloc_count > 0) o->flags |= SEC_RELOC; else { /* Explicitly clear the SEC_RELOC flag. The linker tends to set it (this is probably a bug) and if it is set assign_section_numbers will create a reloc section. */ o->flags &=~ SEC_RELOC; } /* If the SEC_ALLOC flag is not set, force the section VMA to zero. This is done in elf_fake_sections as well, but forcing the VMA to 0 here will ensure that relocs against these sections are handled correctly. */ if ((o->flags & SEC_ALLOC) == 0) o->vma = 0; } /* Figure out the file positions for everything but the symbol table and the relocs. We set symcount to force assign_section_numbers to create a symbol table. */ abfd->symcount = info->strip == strip_all ? 0 : 1; BFD_ASSERT (! abfd->output_has_begun); if (! elf_compute_section_file_positions (abfd, info)) goto error_return; /* That created the reloc sections. Set their sizes, and assign them file positions, and allocate some buffers. */ for (o = abfd->sections; o != NULL; o = o->next) { if ((o->flags & SEC_RELOC) != 0) { Elf_Internal_Shdr *rel_hdr; register struct elf_link_hash_entry **p, **pend; rel_hdr = &elf_section_data (o)->rel_hdr; rel_hdr->sh_size = rel_hdr->sh_entsize * o->reloc_count; /* The contents field must last into write_object_contents, so we allocate it with bfd_alloc rather than malloc. */ rel_hdr->contents = (PTR) bfd_alloc (abfd, rel_hdr->sh_size); if (rel_hdr->contents == NULL && rel_hdr->sh_size != 0) { bfd_set_error (bfd_error_no_memory); goto error_return; } p = ((struct elf_link_hash_entry **) malloc (o->reloc_count * sizeof (struct elf_link_hash_entry *))); if (p == NULL && o->reloc_count != 0) { bfd_set_error (bfd_error_no_memory); goto error_return; } elf_section_data (o)->rel_hashes = p; pend = p + o->reloc_count; for (; p < pend; p++) *p = NULL; /* Use the reloc_count field as an index when outputting the relocs. */ o->reloc_count = 0; } } assign_file_positions_for_relocs (abfd); /* We have now assigned file positions for all the sections except .symtab and .strtab. We start the .symtab section at the current file position, and write directly to it. We build the .strtab section in memory. When we add .dynsym support, we will build that in memory as well (.dynsym is smaller than .symtab). */ abfd->symcount = 0; symtab_hdr = &elf_tdata (abfd)->symtab_hdr; /* sh_name is set in prep_headers. */ symtab_hdr->sh_type = SHT_SYMTAB; symtab_hdr->sh_flags = 0; symtab_hdr->sh_addr = 0; symtab_hdr->sh_size = 0; symtab_hdr->sh_entsize = sizeof (Elf_External_Sym); /* sh_link is set in assign_section_numbers. */ /* sh_info is set below. */ /* sh_offset is set just below. */ symtab_hdr->sh_addralign = 4; /* FIXME: system dependent? */ off = elf_tdata (abfd)->next_file_pos; off = assign_file_position_for_section (symtab_hdr, off, true); /* Note that at this point elf_tdata (abfd)->next_file_pos is incorrect. We do not yet know the size of the .symtab section. We correct next_file_pos below, after we do know the size. */ /* Allocate a buffer to hold swapped out symbols. This is to avoid continuously seeking to the right position in the file. */ if (! info->keep_memory || max_sym_count < 20) finfo.symbuf_size = 20; else finfo.symbuf_size = max_sym_count; finfo.symbuf = ((Elf_External_Sym *) malloc (finfo.symbuf_size * sizeof (Elf_External_Sym))); if (finfo.symbuf == NULL) { bfd_set_error (bfd_error_no_memory); goto error_return; } /* Start writing out the symbol table. The first symbol is always a dummy symbol. */ elfsym.st_value = 0; elfsym.st_size = 0; elfsym.st_info = 0; elfsym.st_other = 0; elfsym.st_shndx = SHN_UNDEF; if (! elf_link_output_sym (&finfo, (const char *) NULL, &elfsym, bfd_und_section_ptr)) goto error_return; #if 0 /* Some standard ELF linkers do this, but we don't because it causes bootstrap comparison failures. */ /* Output a file symbol for the output file as the second symbol. We output this even if we are discarding local symbols, although I'm not sure if this is correct. */ elfsym.st_value = 0; elfsym.st_size = 0; elfsym.st_info = ELF_ST_INFO (STB_LOCAL, STT_FILE); elfsym.st_other = 0; elfsym.st_shndx = SHN_ABS; if (! elf_link_output_sym (&finfo, bfd_get_filename (abfd), &elfsym, bfd_abs_section_ptr)) goto error_return; #endif /* Output a symbol for each section. We output these even if we are discarding local symbols, since they are used for relocs. These symbols have no names. We store the index of each one in the index field of the section, so that we can find it again when outputting relocs. */ elfsym.st_value = 0; elfsym.st_size = 0; elfsym.st_info = ELF_ST_INFO (STB_LOCAL, STT_SECTION); elfsym.st_other = 0; for (i = 1; i < elf_elfheader (abfd)->e_shnum; i++) { o = section_from_elf_index (abfd, i); if (! bfd_is_abs_section (o)) o->target_index = abfd->symcount; elfsym.st_shndx = i; if (! elf_link_output_sym (&finfo, (const char *) NULL, &elfsym, o)) goto error_return; } /* Allocate some memory to hold information read in from the input files. */ finfo.contents = (bfd_byte *) malloc (max_contents_size); finfo.external_relocs = (PTR) malloc (max_external_reloc_size); finfo.internal_relocs = ((Elf_Internal_Rela *) malloc (max_internal_reloc_count * sizeof (Elf_Internal_Rela))); finfo.external_syms = ((Elf_External_Sym *) malloc (max_sym_count * sizeof (Elf_External_Sym))); finfo.internal_syms = ((Elf_Internal_Sym *) malloc (max_sym_count * sizeof (Elf_Internal_Sym))); finfo.indices = (long *) malloc (max_sym_count * sizeof (long)); finfo.sections = (asection **) malloc (max_sym_count * sizeof (asection *)); if ((finfo.contents == NULL && max_contents_size != 0) || (finfo.external_relocs == NULL && max_external_reloc_size != 0) || (finfo.internal_relocs == NULL && max_internal_reloc_count != 0) || (finfo.external_syms == NULL && max_sym_count != 0) || (finfo.internal_syms == NULL && max_sym_count != 0) || (finfo.indices == NULL && max_sym_count != 0) || (finfo.sections == NULL && max_sym_count != 0)) { bfd_set_error (bfd_error_no_memory); goto error_return; } /* Since ELF permits relocations to be against local symbols, we must have the local symbols available when we do the relocations. Since we would rather only read the local symbols once, and we would rather not keep them in memory, we handle all the relocations for a single input file at the same time. Unfortunately, there is no way to know the total number of local symbols until we have seen all of them, and the local symbol indices precede the global symbol indices. This means that when we are generating relocateable output, and we see a reloc against a global symbol, we can not know the symbol index until we have finished examining all the local symbols to see which ones we are going to output. To deal with this, we keep the relocations in memory, and don't output them until the end of the link. This is an unfortunate waste of memory, but I don't see a good way around it. Fortunately, it only happens when performing a relocateable link, which is not the common case. FIXME: If keep_memory is set we could write the relocs out and then read them again; I don't know how bad the memory loss will be. */ for (sub = info->input_bfds; sub != NULL; sub = sub->next) sub->output_has_begun = false; for (o = abfd->sections; o != NULL; o = o->next) { for (p = o->link_order_head; p != NULL; p = p->next) { if (p->type == bfd_indirect_link_order && (bfd_get_flavour (p->u.indirect.section->owner) == bfd_target_elf_flavour)) { sub = p->u.indirect.section->owner; if (! sub->output_has_begun) { if (! elf_link_input_bfd (&finfo, sub)) goto error_return; sub->output_has_begun = true; } } else if (p->type == bfd_section_reloc_link_order || p->type == bfd_symbol_reloc_link_order) { if (! elf_reloc_link_order (abfd, info, o, p)) goto error_return; } else { if (! _bfd_default_link_order (abfd, info, o, p)) goto error_return; } } } /* That wrote out all the local symbols. Finish up the symbol table with the global symbols. */ /* The sh_info field records the index of the first non local symbol. */ symtab_hdr->sh_info = abfd->symcount; if (dynobj != NULL) elf_section_data (finfo.dynsym_sec->output_section)->this_hdr.sh_info = 1; /* We get the global symbols from the hash table. */ elf_link_hash_traverse (elf_hash_table (info), elf_link_output_extsym, (PTR) &finfo); /* Flush all symbols to the file. */ if (! elf_link_flush_output_syms (&finfo)) return false; /* Now we know the size of the symtab section. */ off += symtab_hdr->sh_size; /* Finish up the symbol string table (.strtab) section. */ symstrtab_hdr = &elf_tdata (abfd)->strtab_hdr; /* sh_name was set in prep_headers. */ symstrtab_hdr->sh_type = SHT_STRTAB; symstrtab_hdr->sh_flags = 0; symstrtab_hdr->sh_addr = 0; symstrtab_hdr->sh_size = finfo.symstrtab->length; symstrtab_hdr->sh_entsize = 0; symstrtab_hdr->sh_link = 0; symstrtab_hdr->sh_info = 0; /* sh_offset is set just below. */ symstrtab_hdr->sh_addralign = 1; symstrtab_hdr->contents = (PTR) finfo.symstrtab->tab; off = assign_file_position_for_section (symstrtab_hdr, off, true); elf_tdata (abfd)->next_file_pos = off; /* Adjust the relocs to have the correct symbol indices. */ for (o = abfd->sections; o != NULL; o = o->next) { struct elf_link_hash_entry **rel_hash; Elf_Internal_Shdr *rel_hdr; if ((o->flags & SEC_RELOC) == 0) continue; rel_hash = elf_section_data (o)->rel_hashes; rel_hdr = &elf_section_data (o)->rel_hdr; for (i = 0; i < o->reloc_count; i++, rel_hash++) { if (*rel_hash == NULL) continue; BFD_ASSERT ((*rel_hash)->indx >= 0); if (rel_hdr->sh_entsize == sizeof (Elf_External_Rel)) { Elf_External_Rel *erel; Elf_Internal_Rel irel; erel = (Elf_External_Rel *) rel_hdr->contents + i; elf_swap_reloc_in (abfd, erel, &irel); irel.r_info = ELF_R_INFO ((*rel_hash)->indx, ELF_R_TYPE (irel.r_info)); elf_swap_reloc_out (abfd, &irel, erel); } else { Elf_External_Rela *erela; Elf_Internal_Rela irela; BFD_ASSERT (rel_hdr->sh_entsize == sizeof (Elf_External_Rela)); erela = (Elf_External_Rela *) rel_hdr->contents + i; elf_swap_reloca_in (abfd, erela, &irela); irela.r_info = ELF_R_INFO ((*rel_hash)->indx, ELF_R_TYPE (irela.r_info)); elf_swap_reloca_out (abfd, &irela, erela); } } /* Set the reloc_count field to 0 to prevent write_relocs from trying to swap the relocs out itself. */ o->reloc_count = 0; } /* If we are linking against a dynamic object, finish up the dynamic linking information. */ if (dynobj != NULL) { Elf_External_Dyn *dyncon, *dynconend; /* Fix up .dynamic entries. */ o = bfd_get_section_by_name (dynobj, ".dynamic"); BFD_ASSERT (o != NULL); dyncon = (Elf_External_Dyn *) o->contents; dynconend = (Elf_External_Dyn *) (o->contents + o->_raw_size); for (; dyncon < dynconend; dyncon++) { Elf_Internal_Dyn dyn; const char *name; unsigned int type; elf_swap_dyn_in (dynobj, dyncon, &dyn); switch (dyn.d_tag) { default: break; case DT_INIT: name = ".init"; goto get_vma; case DT_FINI: name = ".fini"; goto get_vma; case DT_HASH: name = ".hash"; goto get_vma; case DT_STRTAB: name = ".dynstr"; goto get_vma; case DT_SYMTAB: name = ".dynsym"; get_vma: o = bfd_get_section_by_name (abfd, name); BFD_ASSERT (o != NULL); dyn.d_un.d_ptr = o->vma; elf_swap_dyn_out (dynobj, &dyn, dyncon); break; case DT_REL: case DT_RELA: case DT_RELSZ: case DT_RELASZ: if (dyn.d_tag == DT_REL || dyn.d_tag == DT_RELSZ) type = SHT_REL; else type = SHT_RELA; dyn.d_un.d_val = 0; for (i = 1; i < elf_elfheader (abfd)->e_shnum; i++) { Elf_Internal_Shdr *hdr; hdr = elf_elfsections (abfd)[i]; if (hdr->sh_type == type && (hdr->sh_flags & SHF_ALLOC) != 0) { if (dyn.d_tag == DT_RELSZ || dyn.d_tag == DT_RELASZ) dyn.d_un.d_val += hdr->sh_size; else { if (dyn.d_un.d_val == 0 || hdr->sh_addr < dyn.d_un.d_val) dyn.d_un.d_val = hdr->sh_addr; } } } elf_swap_dyn_out (dynobj, &dyn, dyncon); break; } } if (! (*bed->elf_backend_finish_dynamic_sections) (abfd, info)) goto error_return; for (o = dynobj->sections; o != NULL; o = o->next) { if ((o->flags & SEC_HAS_CONTENTS) == 0) continue; if ((o->flags & SEC_IN_MEMORY) == 0) { /* At this point, we are only interested in sections created by elf_link_create_dynamic_sections. FIXME: This test is fragile. */ continue; } if (! bfd_set_section_contents (abfd, o->output_section, o->contents, o->output_offset, o->_raw_size)) goto error_return; } } if (finfo.contents != NULL) free (finfo.contents); if (finfo.external_relocs != NULL) free (finfo.external_relocs); if (finfo.internal_relocs != NULL) free (finfo.internal_relocs); if (finfo.external_syms != NULL) free (finfo.external_syms); if (finfo.internal_syms != NULL) free (finfo.internal_syms); if (finfo.indices != NULL) free (finfo.indices); if (finfo.sections != NULL) free (finfo.sections); if (finfo.symbuf != NULL) free (finfo.symbuf); for (o = abfd->sections; o != NULL; o = o->next) { if ((o->flags & SEC_RELOC) != 0 && elf_section_data (o)->rel_hashes != NULL) free (elf_section_data (o)->rel_hashes); } elf_tdata (abfd)->linker = true; return true; error_return: if (finfo.contents != NULL) free (finfo.contents); if (finfo.external_relocs != NULL) free (finfo.external_relocs); if (finfo.internal_relocs != NULL) free (finfo.internal_relocs); if (finfo.external_syms != NULL) free (finfo.external_syms); if (finfo.internal_syms != NULL) free (finfo.internal_syms); if (finfo.indices != NULL) free (finfo.indices); if (finfo.sections != NULL) free (finfo.sections); if (finfo.symbuf != NULL) free (finfo.symbuf); for (o = abfd->sections; o != NULL; o = o->next) { if ((o->flags & SEC_RELOC) != 0 && elf_section_data (o)->rel_hashes != NULL) free (elf_section_data (o)->rel_hashes); } return false; } /* Add a symbol to the output symbol table. */ static boolean elf_link_output_sym (finfo, name, elfsym, input_sec) struct elf_final_link_info *finfo; const char *name; Elf_Internal_Sym *elfsym; asection *input_sec; { boolean (*output_symbol_hook) PARAMS ((bfd *, struct bfd_link_info *info, const char *, Elf_Internal_Sym *, asection *)); output_symbol_hook = get_elf_backend_data (finfo->output_bfd)-> elf_backend_link_output_symbol_hook; if (output_symbol_hook != NULL) { if (! ((*output_symbol_hook) (finfo->output_bfd, finfo->info, name, elfsym, input_sec))) return false; } if (name == (const char *) NULL || *name == '\0') elfsym->st_name = 0; else { elfsym->st_name = bfd_add_to_strtab (finfo->output_bfd, finfo->symstrtab, name); if (elfsym->st_name == (unsigned long) -1) return false; } if (finfo->symbuf_count >= finfo->symbuf_size) { if (! elf_link_flush_output_syms (finfo)) return false; } elf_swap_symbol_out (finfo->output_bfd, elfsym, finfo->symbuf + finfo->symbuf_count); ++finfo->symbuf_count; ++finfo->output_bfd->symcount; return true; } /* Flush the output symbols to the file. */ static boolean elf_link_flush_output_syms (finfo) struct elf_final_link_info *finfo; { Elf_Internal_Shdr *symtab; symtab = &elf_tdata (finfo->output_bfd)->symtab_hdr; if (bfd_seek (finfo->output_bfd, symtab->sh_offset + symtab->sh_size, SEEK_SET) != 0 || (bfd_write ((PTR) finfo->symbuf, finfo->symbuf_count, sizeof (Elf_External_Sym), finfo->output_bfd) != finfo->symbuf_count * sizeof (Elf_External_Sym))) return false; symtab->sh_size += finfo->symbuf_count * sizeof (Elf_External_Sym); finfo->symbuf_count = 0; return true; } /* Add an external symbol to the symbol table. This is called from the hash table traversal routine. */ static boolean elf_link_output_extsym (h, data) struct elf_link_hash_entry *h; PTR data; { struct elf_final_link_info *finfo = (struct elf_final_link_info *) data; boolean strip; Elf_Internal_Sym sym; asection *input_sec; /* We don't want to output symbols that have never been mentioned by a regular file, or that we have been told to strip. However, if h->indx is set to -2, the symbol is used by a reloc and we must output it. */ if (h->indx == -2) strip = false; else if (((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0 || (h->elf_link_hash_flags & ELF_LINK_HASH_REF_DYNAMIC) != 0) && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0 && (h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR) == 0) strip = true; else if (finfo->info->strip == strip_all || (finfo->info->strip == strip_some && bfd_hash_lookup (finfo->info->keep_hash, h->root.root.string, false, false) == NULL)) strip = true; else strip = false; /* If we're stripping it, and it's not a dynamic symbol, there's nothing else to do. */ if (strip && h->dynindx == -1) return true; sym.st_value = 0; sym.st_size = h->size; sym.st_other = 0; if (h->root.type == bfd_link_hash_weak || (h->elf_link_hash_flags & ELF_LINK_HASH_DEFINED_WEAK) != 0) sym.st_info = ELF_ST_INFO (STB_WEAK, h->type); else sym.st_info = ELF_ST_INFO (STB_GLOBAL, h->type); switch (h->root.type) { default: case bfd_link_hash_new: abort (); return false; case bfd_link_hash_undefined: input_sec = bfd_und_section_ptr; sym.st_shndx = SHN_UNDEF; break; case bfd_link_hash_weak: input_sec = bfd_und_section_ptr; sym.st_shndx = SHN_UNDEF; break; case bfd_link_hash_defined: { input_sec = h->root.u.def.section; if (input_sec->output_section != NULL) { sym.st_shndx = elf_section_from_bfd_section (finfo->output_bfd, input_sec->output_section); if (sym.st_shndx == (unsigned short) -1) { /* FIXME: No way to handle errors. */ abort (); } /* ELF symbols in relocateable files are section relative, but in nonrelocateable files they are virtual addresses. */ sym.st_value = h->root.u.def.value + input_sec->output_offset; if (! finfo->info->relocateable) sym.st_value += input_sec->output_section->vma; } else { BFD_ASSERT (bfd_get_flavour (input_sec->owner) == bfd_target_elf_flavour && elf_elfheader (input_sec->owner)->e_type == ET_DYN); sym.st_shndx = SHN_UNDEF; input_sec = bfd_und_section_ptr; } } break; case bfd_link_hash_common: input_sec = bfd_com_section_ptr; sym.st_shndx = SHN_COMMON; sym.st_value = 1 << h->root.u.c.alignment_power; break; case bfd_link_hash_indirect: case bfd_link_hash_warning: /* I have no idea how these should be handled. */ return true; } /* If this symbol should be put in the .dynsym section, then put it there now. We have already know the symbol index. We also fill in the entry in the .hash section. */ if (h->dynindx != -1) { struct elf_backend_data *bed; size_t bucketcount; size_t bucket; bfd_byte *bucketpos; bfd_vma chain; sym.st_name = h->dynstr_index; /* Give the processor backend a chance to tweak the symbol value, and also to finish up anything that needs to be done for this symbol. */ bed = get_elf_backend_data (finfo->output_bfd); if (! ((*bed->elf_backend_finish_dynamic_symbol) (finfo->output_bfd, finfo->info, h, &sym))) { /* FIXME: No way to return error. */ abort (); } elf_swap_symbol_out (finfo->output_bfd, &sym, ((Elf_External_Sym *) finfo->dynsym_sec->contents + h->dynindx)); bucketcount = elf_hash_table (finfo->info)->bucketcount; bucket = bfd_elf_hash ((const unsigned char *) h->root.root.string) % bucketcount; bucketpos = ((bfd_byte *) finfo->hash_sec->contents + (bucket + 2) * (ARCH_SIZE / 8)); chain = get_word (finfo->output_bfd, bucketpos); put_word (finfo->output_bfd, h->dynindx, bucketpos); put_word (finfo->output_bfd, chain, ((bfd_byte *) finfo->hash_sec->contents + (bucketcount + 2 + h->dynindx) * (ARCH_SIZE / 8))); } /* If we're stripping it, then it was just a dynamic symbol, and there's nothing else to do. */ if (strip) return true; h->indx = finfo->output_bfd->symcount; if (! elf_link_output_sym (finfo, h->root.root.string, &sym, input_sec)) { /* FIXME: No way to return error. */ abort (); } return true; } /* Link an input file into the linker output file. This function handles all the sections and relocations of the input file at once. This is so that we only have to read the local symbols once, and don't have to keep them in memory. */ static boolean elf_link_input_bfd (finfo, input_bfd) struct elf_final_link_info *finfo; bfd *input_bfd; { boolean (*relocate_section) PARAMS ((bfd *, struct bfd_link_info *, bfd *, asection *, bfd_byte *, Elf_Internal_Rela *, Elf_Internal_Sym *, asection **, char *)); bfd *output_bfd; Elf_Internal_Shdr *symtab_hdr; size_t locsymcount; size_t extsymoff; Elf_External_Sym *esym; Elf_External_Sym *esymend; Elf_Internal_Sym *isym; long *pindex; asection **ppsection; asection *o; output_bfd = finfo->output_bfd; relocate_section = get_elf_backend_data (output_bfd)->elf_backend_relocate_section; /* If this is a dynamic object, we don't want to do anything here: we don't want the local symbols, and we don't want the section contents. */ if (elf_elfheader (input_bfd)->e_type == ET_DYN) return true; symtab_hdr = &elf_tdata (input_bfd)->symtab_hdr; if (elf_bad_symtab (input_bfd)) { locsymcount = symtab_hdr->sh_size / sizeof (Elf_External_Sym); extsymoff = 0; } else { locsymcount = symtab_hdr->sh_info; extsymoff = symtab_hdr->sh_info; } /* Read the local symbols. */ if (locsymcount > 0 && (bfd_seek (input_bfd, symtab_hdr->sh_offset, SEEK_SET) != 0 || (bfd_read (finfo->external_syms, sizeof (Elf_External_Sym), locsymcount, input_bfd) != locsymcount * sizeof (Elf_External_Sym)))) return false; /* Swap in the local symbols and write out the ones which we know are going into the output file. */ esym = finfo->external_syms; esymend = esym + locsymcount; isym = finfo->internal_syms; pindex = finfo->indices; ppsection = finfo->sections; for (; esym < esymend; esym++, isym++, pindex++, ppsection++) { asection *isec; const char *name; bfd_vma oldval; elf_swap_symbol_in (input_bfd, esym, isym); *pindex = -1; if (elf_bad_symtab (input_bfd)) { if (ELF_ST_BIND (isym->st_info) != STB_LOCAL) { *ppsection = NULL; continue; } } if (isym->st_shndx == SHN_UNDEF) isec = bfd_und_section_ptr; else if (isym->st_shndx > 0 && isym->st_shndx < SHN_LORESERVE) { isec = section_from_elf_index (input_bfd, isym->st_shndx); if (isec == NULL) return false; } else if (isym->st_shndx == SHN_ABS) isec = bfd_abs_section_ptr; else if (isym->st_shndx == SHN_COMMON) isec = bfd_com_section_ptr; else { /* Who knows? */ isec = NULL; } *ppsection = isec; /* Don't output the first, undefined, symbol. */ if (esym == finfo->external_syms) continue; /* If we are stripping all symbols, we don't want to output this one. */ if (finfo->info->strip == strip_all) continue; /* We never output section symbols. Instead, we use the section symbol of the corresponding section in the output file. */ if (ELF_ST_TYPE (isym->st_info) == STT_SECTION) continue; /* If we are discarding all local symbols, we don't want to output this one. If we are generating a relocateable output file, then some of the local symbols may be required by relocs; we output them below as we discover that they are needed. */ if (finfo->info->discard == discard_all) continue; /* Get the name of the symbol. */ name = elf_string_from_elf_section (input_bfd, symtab_hdr->sh_link, isym->st_name); if (name == NULL) return false; /* See if we are discarding symbols with this name. */ if ((finfo->info->strip == strip_some && (bfd_hash_lookup (finfo->info->keep_hash, name, false, false) == NULL)) || (finfo->info->discard == discard_l && strncmp (name, finfo->info->lprefix, finfo->info->lprefix_len) == 0)) continue; /* If we get here, we are going to output this symbol. */ /* Adjust the section index for the output file. */ isym->st_shndx = elf_section_from_bfd_section (output_bfd, isec->output_section); if (isym->st_shndx == (unsigned short) -1) return false; *pindex = output_bfd->symcount; /* ELF symbols in relocateable files are section relative, but in executable files they are virtual addresses. Note that this code assumes that all ELF sections have an associated BFD section with a reasonable value for output_offset; below we assume that they also have a reasonable value for output_section. Any special sections must be set up to meet these requirements. */ oldval = isym->st_value; isym->st_value += isec->output_offset; if (! finfo->info->relocateable) isym->st_value += isec->output_section->vma; if (! elf_link_output_sym (finfo, name, isym, isec)) return false; /* Restore the old value for reloc handling. */ isym->st_value = oldval; } /* Relocate the contents of each section. */ for (o = input_bfd->sections; o != NULL; o = o->next) { if ((o->flags & SEC_HAS_CONTENTS) == 0) continue; if ((o->flags & SEC_IN_MEMORY) != 0 && input_bfd == elf_hash_table (finfo->info)->dynobj) { /* Section was created by elf_link_create_dynamic_sections. FIXME: This test is fragile. */ continue; } /* Read the contents of the section. */ if (! bfd_get_section_contents (input_bfd, o, finfo->contents, (file_ptr) 0, o->_raw_size)) return false; if ((o->flags & SEC_RELOC) != 0) { Elf_Internal_Rela *internal_relocs; /* Get the swapped relocs. */ internal_relocs = elf_link_read_relocs (input_bfd, o, finfo->external_relocs, finfo->internal_relocs, false); if (internal_relocs == NULL && o->reloc_count > 0) return false; /* Relocate the section by invoking a back end routine. The back end routine is responsible for adjusting the section contents as necessary, and (if using Rela relocs and generating a relocateable output file) adjusting the reloc addend as necessary. The back end routine does not have to worry about setting the reloc address or the reloc symbol index. The back end routine is given a pointer to the swapped in internal symbols, and can access the hash table entries for the external symbols via elf_sym_hashes (input_bfd). When generating relocateable output, the back end routine must handle STB_LOCAL/STT_SECTION symbols specially. The output symbol is going to be a section symbol corresponding to the output section, which will require the addend to be adjusted. */ if (! (*relocate_section) (output_bfd, finfo->info, input_bfd, o, finfo->contents, internal_relocs, finfo->internal_syms, finfo->sections, finfo->symstrtab->tab)) return false; if (finfo->info->relocateable) { Elf_Internal_Rela *irela; Elf_Internal_Rela *irelaend; struct elf_link_hash_entry **rel_hash; Elf_Internal_Shdr *input_rel_hdr; Elf_Internal_Shdr *output_rel_hdr; /* Adjust the reloc addresses and symbol indices. */ irela = internal_relocs; irelaend = irela + o->reloc_count; rel_hash = (elf_section_data (o->output_section)->rel_hashes + o->output_section->reloc_count); for (; irela < irelaend; irela++, rel_hash++) { long r_symndx; Elf_Internal_Sym *isym; asection *sec; irela->r_offset += o->output_offset; r_symndx = ELF_R_SYM (irela->r_info); if (r_symndx == 0) continue; if (r_symndx >= locsymcount || (elf_bad_symtab (input_bfd) && finfo->sections[r_symndx] == NULL)) { long indx; /* This is a reloc against a global symbol. We have not yet output all the local symbols, so we do not know the symbol index of any global symbol. We set the rel_hash entry for this reloc to point to the global hash table entry for this symbol. The symbol index is then set at the end of elf_bfd_final_link. */ indx = r_symndx - extsymoff; *rel_hash = elf_sym_hashes (input_bfd)[indx]; /* Setting the index to -2 tells elf_link_output_extsym that this symbol is used by a reloc. */ BFD_ASSERT ((*rel_hash)->indx < 0); (*rel_hash)->indx = -2; continue; } /* This is a reloc against a local symbol. */ *rel_hash = NULL; isym = finfo->internal_syms + r_symndx; sec = finfo->sections[r_symndx]; if (ELF_ST_TYPE (isym->st_info) == STT_SECTION) { /* I suppose the backend ought to fill in the section of any STT_SECTION symbol against a processor specific section. */ if (sec != NULL && bfd_is_abs_section (sec)) r_symndx = 0; else if (sec == NULL || sec->owner == NULL) { bfd_set_error (bfd_error_bad_value); return false; } else { r_symndx = sec->output_section->target_index; if (r_symndx == 0) abort (); } } else { if (finfo->indices[r_symndx] == -1) { unsigned long link; const char *name; asection *osec; if (finfo->info->strip == strip_all) { /* You can't do ld -r -s. */ bfd_set_error (bfd_error_invalid_operation); return false; } /* This symbol was skipped earlier, but since it is needed by a reloc, we must output it now. */ link = symtab_hdr->sh_link; name = elf_string_from_elf_section (input_bfd, link, isym->st_name); if (name == NULL) return false; osec = sec->output_section; isym->st_shndx = elf_section_from_bfd_section (output_bfd, osec); if (isym->st_shndx == (unsigned short) -1) return false; isym->st_value += sec->output_offset; if (! finfo->info->relocateable) isym->st_value += osec->vma; finfo->indices[r_symndx] = output_bfd->symcount; if (! elf_link_output_sym (finfo, name, isym, sec)) return false; } r_symndx = finfo->indices[r_symndx]; } irela->r_info = ELF_R_INFO (r_symndx, ELF_R_TYPE (irela->r_info)); } /* Swap out the relocs. */ input_rel_hdr = &elf_section_data (o)->rel_hdr; output_rel_hdr = &elf_section_data (o->output_section)->rel_hdr; BFD_ASSERT (output_rel_hdr->sh_entsize == input_rel_hdr->sh_entsize); irela = internal_relocs; irelaend = irela + o->reloc_count; if (input_rel_hdr->sh_entsize == sizeof (Elf_External_Rel)) { Elf_External_Rel *erel; erel = ((Elf_External_Rel *) output_rel_hdr->contents + o->output_section->reloc_count); for (; irela < irelaend; irela++, erel++) { Elf_Internal_Rel irel; irel.r_offset = irela->r_offset; irel.r_info = irela->r_info; BFD_ASSERT (irela->r_addend == 0); elf_swap_reloc_out (output_bfd, &irel, erel); } } else { Elf_External_Rela *erela; BFD_ASSERT (input_rel_hdr->sh_entsize == sizeof (Elf_External_Rela)); erela = ((Elf_External_Rela *) output_rel_hdr->contents + o->output_section->reloc_count); for (; irela < irelaend; irela++, erela++) elf_swap_reloca_out (output_bfd, irela, erela); } o->output_section->reloc_count += o->reloc_count; } } /* Write out the modified section contents. */ if (! bfd_set_section_contents (output_bfd, o->output_section, finfo->contents, o->output_offset, (o->_cooked_size != 0 ? o->_cooked_size : o->_raw_size))) return false; } return true; } /* Generate a reloc when linking an ELF file. This is a reloc requested by the linker, and does come from any input file. This is used to build constructor and destructor tables when linking with -Ur. */ static boolean elf_reloc_link_order (output_bfd, info, output_section, link_order) bfd *output_bfd; struct bfd_link_info *info; asection *output_section; struct bfd_link_order *link_order; { const reloc_howto_type *howto; long indx; bfd_vma offset; struct elf_link_hash_entry **rel_hash_ptr; Elf_Internal_Shdr *rel_hdr; howto = bfd_reloc_type_lookup (output_bfd, link_order->u.reloc.p->reloc); if (howto == NULL) { bfd_set_error (bfd_error_bad_value); return false; } /* If this is an inplace reloc, we must write the addend into the object file. */ if (howto->partial_inplace && link_order->u.reloc.p->addend != 0) { bfd_size_type size; bfd_reloc_status_type rstat; bfd_byte *buf; boolean ok; size = bfd_get_reloc_size (howto); buf = (bfd_byte *) bfd_zmalloc (size); if (buf == (bfd_byte *) NULL) { bfd_set_error (bfd_error_no_memory); return false; } rstat = _bfd_relocate_contents (howto, output_bfd, link_order->u.reloc.p->addend, buf); switch (rstat) { case bfd_reloc_ok: break; default: case bfd_reloc_outofrange: abort (); case bfd_reloc_overflow: if (! ((*info->callbacks->reloc_overflow) (info, (link_order->type == bfd_section_reloc_link_order ? bfd_section_name (output_bfd, link_order->u.reloc.p->u.section) : link_order->u.reloc.p->u.name), howto->name, link_order->u.reloc.p->addend, (bfd *) NULL, (asection *) NULL, (bfd_vma) 0))) { free (buf); return false; } break; } ok = bfd_set_section_contents (output_bfd, output_section, (PTR) buf, (file_ptr) link_order->offset, size); free (buf); if (! ok) return false; } /* Figure out the symbol index. */ rel_hash_ptr = (elf_section_data (output_section)->rel_hashes + output_section->reloc_count); if (link_order->type == bfd_section_reloc_link_order) { indx = link_order->u.reloc.p->u.section->target_index; if (indx == 0) abort (); *rel_hash_ptr = NULL; } else { struct elf_link_hash_entry *h; h = elf_link_hash_lookup (elf_hash_table (info), link_order->u.reloc.p->u.name, false, false, true); if (h != NULL) { /* Setting the index to -2 tells elf_link_output_extsym that this symbol is used by a reloc. */ h->indx = -2; *rel_hash_ptr = h; indx = 0; } else { if (! ((*info->callbacks->unattached_reloc) (info, link_order->u.reloc.p->u.name, (bfd *) NULL, (asection *) NULL, (bfd_vma) 0))) return false; indx = 0; } } /* The address of a reloc is relative to the section in a relocateable file, and is a virtual address in an executable file. */ offset = link_order->offset; if (! info->relocateable) offset += output_section->vma; rel_hdr = &elf_section_data (output_section)->rel_hdr; if (rel_hdr->sh_type == SHT_REL) { Elf_Internal_Rel irel; Elf_External_Rel *erel; irel.r_offset = offset; irel.r_info = ELF_R_INFO (indx, howto->type); erel = ((Elf_External_Rel *) rel_hdr->contents + output_section->reloc_count); elf_swap_reloc_out (output_bfd, &irel, erel); } else { Elf_Internal_Rela irela; Elf_External_Rela *erela; irela.r_offset = offset; irela.r_info = ELF_R_INFO (indx, howto->type); irela.r_addend = link_order->u.reloc.p->addend; erela = ((Elf_External_Rela *) rel_hdr->contents + output_section->reloc_count); elf_swap_reloca_out (output_bfd, &irela, erela); } ++output_section->reloc_count; return true; }