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[/] [openrisc/] [trunk/] [gnu-src/] [gdb-6.8/] [bfd/] [elfcode.h] - Rev 24
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/* ELF executable support for BFD. Copyright 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007 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 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, 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 "sysdep.h" #include "bfd.h" #include "libiberty.h" #include "bfdlink.h" #include "libbfd.h" #include "elf-bfd.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_phdr_in NAME(bfd_elf,swap_phdr_in) #define elf_swap_phdr_out NAME(bfd_elf,swap_phdr_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_slurp_symbol_table NAME(bfd_elf,slurp_symbol_table) #define elf_canonicalize_symtab NAME(bfd_elf,canonicalize_symtab) #define elf_canonicalize_dynamic_symtab \ NAME(bfd_elf,canonicalize_dynamic_symtab) #define elf_get_synthetic_symtab \ NAME(bfd_elf,get_synthetic_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_find_section NAME(bfd_elf,find_section) #define elf_write_shdrs_and_ehdr NAME(bfd_elf,write_shdrs_and_ehdr) #define elf_write_out_phdrs NAME(bfd_elf,write_out_phdrs) #define elf_checksum_contents NAME(bfd_elf,checksum_contents) #define elf_write_relocs NAME(bfd_elf,write_relocs) #define elf_slurp_reloc_table NAME(bfd_elf,slurp_reloc_table) #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 #if DEBUG & 2 static void elf_debug_section (int, Elf_Internal_Shdr *); #endif #if DEBUG & 1 static void elf_debug_file (Elf_Internal_Ehdr *); #endif /* 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 H_PUT_WORD H_PUT_64 #define H_PUT_SIGNED_WORD H_PUT_S64 #define H_GET_WORD H_GET_64 #define H_GET_SIGNED_WORD H_GET_S64 #endif #if ARCH_SIZE == 32 #define H_PUT_WORD H_PUT_32 #define H_PUT_SIGNED_WORD H_PUT_S32 #define H_GET_WORD H_GET_32 #define H_GET_SIGNED_WORD H_GET_S32 #endif /* Translate an ELF symbol in external format into an ELF symbol in internal format. */ bfd_boolean elf_swap_symbol_in (bfd *abfd, const void *psrc, const void *pshn, Elf_Internal_Sym *dst) { const Elf_External_Sym *src = psrc; const Elf_External_Sym_Shndx *shndx = pshn; int signed_vma = get_elf_backend_data (abfd)->sign_extend_vma; dst->st_name = H_GET_32 (abfd, src->st_name); if (signed_vma) dst->st_value = H_GET_SIGNED_WORD (abfd, src->st_value); else dst->st_value = H_GET_WORD (abfd, src->st_value); dst->st_size = H_GET_WORD (abfd, src->st_size); dst->st_info = H_GET_8 (abfd, src->st_info); dst->st_other = H_GET_8 (abfd, src->st_other); dst->st_shndx = H_GET_16 (abfd, src->st_shndx); if (dst->st_shndx == SHN_XINDEX) { if (shndx == NULL) return FALSE; dst->st_shndx = H_GET_32 (abfd, shndx->est_shndx); } return TRUE; } /* Translate an ELF symbol in internal format into an ELF symbol in external format. */ void elf_swap_symbol_out (bfd *abfd, const Elf_Internal_Sym *src, void *cdst, void *shndx) { unsigned int tmp; Elf_External_Sym *dst = cdst; H_PUT_32 (abfd, src->st_name, dst->st_name); H_PUT_WORD (abfd, src->st_value, dst->st_value); H_PUT_WORD (abfd, src->st_size, dst->st_size); H_PUT_8 (abfd, src->st_info, dst->st_info); H_PUT_8 (abfd, src->st_other, dst->st_other); tmp = src->st_shndx; if (tmp > SHN_HIRESERVE) { if (shndx == NULL) abort (); H_PUT_32 (abfd, tmp, shndx); tmp = SHN_XINDEX; } H_PUT_16 (abfd, tmp, 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 (bfd *abfd, const Elf_External_Ehdr *src, Elf_Internal_Ehdr *dst) { int signed_vma = get_elf_backend_data (abfd)->sign_extend_vma; memcpy (dst->e_ident, src->e_ident, EI_NIDENT); dst->e_type = H_GET_16 (abfd, src->e_type); dst->e_machine = H_GET_16 (abfd, src->e_machine); dst->e_version = H_GET_32 (abfd, src->e_version); if (signed_vma) dst->e_entry = H_GET_SIGNED_WORD (abfd, src->e_entry); else dst->e_entry = H_GET_WORD (abfd, src->e_entry); dst->e_phoff = H_GET_WORD (abfd, src->e_phoff); dst->e_shoff = H_GET_WORD (abfd, src->e_shoff); dst->e_flags = H_GET_32 (abfd, src->e_flags); dst->e_ehsize = H_GET_16 (abfd, src->e_ehsize); dst->e_phentsize = H_GET_16 (abfd, src->e_phentsize); dst->e_phnum = H_GET_16 (abfd, src->e_phnum); dst->e_shentsize = H_GET_16 (abfd, src->e_shentsize); dst->e_shnum = H_GET_16 (abfd, src->e_shnum); dst->e_shstrndx = H_GET_16 (abfd, 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 (bfd *abfd, const Elf_Internal_Ehdr *src, Elf_External_Ehdr *dst) { unsigned int tmp; int signed_vma = get_elf_backend_data (abfd)->sign_extend_vma; memcpy (dst->e_ident, src->e_ident, EI_NIDENT); /* note that all elements of dst are *arrays of unsigned char* already... */ H_PUT_16 (abfd, src->e_type, dst->e_type); H_PUT_16 (abfd, src->e_machine, dst->e_machine); H_PUT_32 (abfd, src->e_version, dst->e_version); if (signed_vma) H_PUT_SIGNED_WORD (abfd, src->e_entry, dst->e_entry); else H_PUT_WORD (abfd, src->e_entry, dst->e_entry); H_PUT_WORD (abfd, src->e_phoff, dst->e_phoff); H_PUT_WORD (abfd, src->e_shoff, dst->e_shoff); H_PUT_32 (abfd, src->e_flags, dst->e_flags); H_PUT_16 (abfd, src->e_ehsize, dst->e_ehsize); H_PUT_16 (abfd, src->e_phentsize, dst->e_phentsize); H_PUT_16 (abfd, src->e_phnum, dst->e_phnum); H_PUT_16 (abfd, src->e_shentsize, dst->e_shentsize); tmp = src->e_shnum; if (tmp >= SHN_LORESERVE) tmp = SHN_UNDEF; H_PUT_16 (abfd, tmp, dst->e_shnum); tmp = src->e_shstrndx; if (tmp >= SHN_LORESERVE) tmp = SHN_XINDEX; H_PUT_16 (abfd, tmp, 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 (bfd *abfd, const Elf_External_Shdr *src, Elf_Internal_Shdr *dst) { int signed_vma = get_elf_backend_data (abfd)->sign_extend_vma; dst->sh_name = H_GET_32 (abfd, src->sh_name); dst->sh_type = H_GET_32 (abfd, src->sh_type); dst->sh_flags = H_GET_WORD (abfd, src->sh_flags); if (signed_vma) dst->sh_addr = H_GET_SIGNED_WORD (abfd, src->sh_addr); else dst->sh_addr = H_GET_WORD (abfd, src->sh_addr); dst->sh_offset = H_GET_WORD (abfd, src->sh_offset); dst->sh_size = H_GET_WORD (abfd, src->sh_size); dst->sh_link = H_GET_32 (abfd, src->sh_link); dst->sh_info = H_GET_32 (abfd, src->sh_info); dst->sh_addralign = H_GET_WORD (abfd, src->sh_addralign); dst->sh_entsize = H_GET_WORD (abfd, src->sh_entsize); dst->bfd_section = NULL; dst->contents = NULL; } /* 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 (bfd *abfd, const Elf_Internal_Shdr *src, Elf_External_Shdr *dst) { /* note that all elements of dst are *arrays of unsigned char* already... */ H_PUT_32 (abfd, src->sh_name, dst->sh_name); H_PUT_32 (abfd, src->sh_type, dst->sh_type); H_PUT_WORD (abfd, src->sh_flags, dst->sh_flags); H_PUT_WORD (abfd, src->sh_addr, dst->sh_addr); H_PUT_WORD (abfd, src->sh_offset, dst->sh_offset); H_PUT_WORD (abfd, src->sh_size, dst->sh_size); H_PUT_32 (abfd, src->sh_link, dst->sh_link); H_PUT_32 (abfd, src->sh_info, dst->sh_info); H_PUT_WORD (abfd, src->sh_addralign, dst->sh_addralign); H_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. */ void elf_swap_phdr_in (bfd *abfd, const Elf_External_Phdr *src, Elf_Internal_Phdr *dst) { int signed_vma = get_elf_backend_data (abfd)->sign_extend_vma; dst->p_type = H_GET_32 (abfd, src->p_type); dst->p_flags = H_GET_32 (abfd, src->p_flags); dst->p_offset = H_GET_WORD (abfd, src->p_offset); if (signed_vma) { dst->p_vaddr = H_GET_SIGNED_WORD (abfd, src->p_vaddr); dst->p_paddr = H_GET_SIGNED_WORD (abfd, src->p_paddr); } else { dst->p_vaddr = H_GET_WORD (abfd, src->p_vaddr); dst->p_paddr = H_GET_WORD (abfd, src->p_paddr); } dst->p_filesz = H_GET_WORD (abfd, src->p_filesz); dst->p_memsz = H_GET_WORD (abfd, src->p_memsz); dst->p_align = H_GET_WORD (abfd, src->p_align); } void elf_swap_phdr_out (bfd *abfd, const Elf_Internal_Phdr *src, Elf_External_Phdr *dst) { const struct elf_backend_data *bed; bfd_vma p_paddr; bed = get_elf_backend_data (abfd); p_paddr = bed->want_p_paddr_set_to_zero ? 0 : src->p_paddr; /* note that all elements of dst are *arrays of unsigned char* already... */ H_PUT_32 (abfd, src->p_type, dst->p_type); H_PUT_WORD (abfd, src->p_offset, dst->p_offset); H_PUT_WORD (abfd, src->p_vaddr, dst->p_vaddr); H_PUT_WORD (abfd, p_paddr, dst->p_paddr); H_PUT_WORD (abfd, src->p_filesz, dst->p_filesz); H_PUT_WORD (abfd, src->p_memsz, dst->p_memsz); H_PUT_32 (abfd, src->p_flags, dst->p_flags); H_PUT_WORD (abfd, src->p_align, dst->p_align); } /* Translate an ELF reloc from external format to internal format. */ void elf_swap_reloc_in (bfd *abfd, const bfd_byte *s, Elf_Internal_Rela *dst) { const Elf_External_Rel *src = (const Elf_External_Rel *) s; dst->r_offset = H_GET_WORD (abfd, src->r_offset); dst->r_info = H_GET_WORD (abfd, src->r_info); dst->r_addend = 0; } void elf_swap_reloca_in (bfd *abfd, const bfd_byte *s, Elf_Internal_Rela *dst) { const Elf_External_Rela *src = (const Elf_External_Rela *) s; dst->r_offset = H_GET_WORD (abfd, src->r_offset); dst->r_info = H_GET_WORD (abfd, src->r_info); dst->r_addend = H_GET_SIGNED_WORD (abfd, src->r_addend); } /* Translate an ELF reloc from internal format to external format. */ void elf_swap_reloc_out (bfd *abfd, const Elf_Internal_Rela *src, bfd_byte *d) { Elf_External_Rel *dst = (Elf_External_Rel *) d; H_PUT_WORD (abfd, src->r_offset, dst->r_offset); H_PUT_WORD (abfd, src->r_info, dst->r_info); } void elf_swap_reloca_out (bfd *abfd, const Elf_Internal_Rela *src, bfd_byte *d) { Elf_External_Rela *dst = (Elf_External_Rela *) d; H_PUT_WORD (abfd, src->r_offset, dst->r_offset); H_PUT_WORD (abfd, src->r_info, dst->r_info); H_PUT_SIGNED_WORD (abfd, src->r_addend, dst->r_addend); } void elf_swap_dyn_in (bfd *abfd, const void *p, Elf_Internal_Dyn *dst) { const Elf_External_Dyn *src = p; dst->d_tag = H_GET_WORD (abfd, src->d_tag); dst->d_un.d_val = H_GET_WORD (abfd, src->d_un.d_val); } void elf_swap_dyn_out (bfd *abfd, const Elf_Internal_Dyn *src, void *p) { Elf_External_Dyn *dst = p; H_PUT_WORD (abfd, src->d_tag, dst->d_tag); H_PUT_WORD (abfd, src->d_un.d_val, dst->d_un.d_val); } /* ELF .o/exec file reading */ /* Begin processing a given object. First we validate the file by reading in the ELF header and checking the magic number. */ static inline bfd_boolean elf_file_p (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)); } /* Determines if a given section index is valid. */ static inline bfd_boolean valid_section_index_p (unsigned index, unsigned num_sections) { /* Note: We allow SHN_UNDEF as a valid section index. */ if (index < SHN_LORESERVE || index > SHN_HIRESERVE) return index < num_sections; /* We disallow the use of reserved indcies, except for those with OS or Application specific meaning. The test make use of the knowledge that: SHN_LORESERVE == SHN_LOPROC and SHN_HIPROC == SHN_LOOS - 1 */ /* XXX - Should we allow SHN_XINDEX as a valid index here ? */ return (index >= SHN_LOPROC && index <= SHN_HIOS); } /* 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 (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_shdr; Elf_Internal_Shdr *i_shdrp; /* Section header table, internal form */ unsigned int shindex; const struct elf_backend_data *ebd; struct bfd_preserve preserve; asection *s; bfd_size_type amt; const bfd_target *target; const bfd_target * const *target_ptr; preserve.marker = NULL; /* Read in the ELF header in external format. */ if (bfd_bread (&x_ehdr, sizeof (x_ehdr), 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) || 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 (! bfd_header_big_endian (abfd)) goto got_wrong_format_error; break; case ELFDATA2LSB: /* Little-endian */ if (! bfd_header_little_endian (abfd)) goto got_wrong_format_error; break; case ELFDATANONE: /* No data encoding specified */ default: /* Unknown data encoding specified */ goto got_wrong_format_error; } if (!bfd_preserve_save (abfd, &preserve)) goto got_no_match; target = abfd->xvec; /* Allocate an instance of the elf_obj_tdata structure and hook it up to the tdata pointer in the bfd. */ if (! (*target->_bfd_set_format[bfd_object]) (abfd)) goto got_no_match; preserve.marker = elf_tdata (abfd); /* 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 /* Reject ET_CORE (header indicates core file, not object file) */ if (i_ehdrp->e_type == ET_CORE) goto got_wrong_format_error; /* If this is a relocatable file and there is no section header table, then we're hosed. */ if (i_ehdrp->e_shoff == 0 && i_ehdrp->e_type == ET_REL) goto got_wrong_format_error; /* As a simple sanity check, verify that what BFD thinks is the size of each section header table entry actually matches the size recorded in the file, but only if there are any sections. */ if (i_ehdrp->e_shentsize != sizeof (x_shdr) && i_ehdrp->e_shnum != 0) goto got_wrong_format_error; /* Further sanity check. */ if (i_ehdrp->e_shoff == 0 && i_ehdrp->e_shnum != 0) 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 && (ebd->elf_machine_alt1 == 0 || i_ehdrp->e_machine != ebd->elf_machine_alt1) && (ebd->elf_machine_alt2 == 0 || i_ehdrp->e_machine != ebd->elf_machine_alt2)) { 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++) { const struct elf_backend_data *back; if ((*target_ptr)->flavour != bfd_target_elf_flavour) continue; back = xvec_get_elf_backend_data (*target_ptr); if (back->elf_machine_code == i_ehdrp->e_machine || (back->elf_machine_alt1 != 0 && back->elf_machine_alt1 == i_ehdrp->e_machine) || (back->elf_machine_alt2 != 0 && back->elf_machine_alt2 == 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)) { /* It's OK if this fails for the generic target. */ if (ebd->elf_machine_code != EM_NONE) goto got_no_match; } if (ebd->elf_machine_code != EM_NONE && i_ehdrp->e_ident[EI_OSABI] != ebd->elf_osabi) { if (ebd->elf_osabi != ELFOSABI_NONE) goto got_wrong_format_error; /* This is an ELFOSABI_NONE ELF target. Let it match any ELF target of the compatible machine for which we do not have a backend with matching ELFOSABI. */ for (target_ptr = bfd_target_vector; *target_ptr != NULL; target_ptr++) { const struct elf_backend_data *back; /* Skip this target and targets with incompatible byte order. */ if (*target_ptr == target || (*target_ptr)->flavour != bfd_target_elf_flavour || (*target_ptr)->byteorder != target->byteorder || ((*target_ptr)->header_byteorder != target->header_byteorder)) continue; back = xvec_get_elf_backend_data (*target_ptr); if (back->elf_osabi == i_ehdrp->e_ident[EI_OSABI] && (back->elf_machine_code == i_ehdrp->e_machine || (back->elf_machine_alt1 != 0 && back->elf_machine_alt1 == i_ehdrp->e_machine) || (back->elf_machine_alt2 != 0 && back->elf_machine_alt2 == i_ehdrp->e_machine))) { /* target_ptr is an ELF backend which matches this object file, so reject the ELFOSABI_NONE ELF target. */ goto got_wrong_format_error; } } } if (i_ehdrp->e_shoff != 0) { bfd_signed_vma where = i_ehdrp->e_shoff; if (where != (file_ptr) where) goto got_wrong_format_error; /* Seek to the section header table in the file. */ if (bfd_seek (abfd, (file_ptr) where, SEEK_SET) != 0) goto got_no_match; /* Read the first section header at index 0, and convert to internal form. */ if (bfd_bread (&x_shdr, sizeof x_shdr, abfd) != sizeof (x_shdr)) goto got_no_match; elf_swap_shdr_in (abfd, &x_shdr, &i_shdr); /* If the section count is zero, the actual count is in the first section header. */ if (i_ehdrp->e_shnum == SHN_UNDEF) { i_ehdrp->e_shnum = i_shdr.sh_size; if (i_ehdrp->e_shnum != i_shdr.sh_size || i_ehdrp->e_shnum == 0) goto got_wrong_format_error; } /* And similarly for the string table index. */ if (i_ehdrp->e_shstrndx == SHN_XINDEX) { i_ehdrp->e_shstrndx = i_shdr.sh_link; if (i_ehdrp->e_shstrndx != i_shdr.sh_link) goto got_wrong_format_error; } /* Sanity check that we can read all of the section headers. It ought to be good enough to just read the last one. */ if (i_ehdrp->e_shnum != 1) { /* Check that we don't have a totally silly number of sections. */ if (i_ehdrp->e_shnum > (unsigned int) -1 / sizeof (x_shdr) || i_ehdrp->e_shnum > (unsigned int) -1 / sizeof (i_shdr)) goto got_wrong_format_error; where += (i_ehdrp->e_shnum - 1) * sizeof (x_shdr); if (where != (file_ptr) where) goto got_wrong_format_error; if ((bfd_size_type) where <= i_ehdrp->e_shoff) goto got_wrong_format_error; if (bfd_seek (abfd, (file_ptr) where, SEEK_SET) != 0) goto got_no_match; if (bfd_bread (&x_shdr, sizeof x_shdr, abfd) != sizeof (x_shdr)) goto got_no_match; /* Back to where we were. */ where = i_ehdrp->e_shoff + sizeof (x_shdr); if (bfd_seek (abfd, (file_ptr) where, SEEK_SET) != 0) goto got_no_match; } } /* Allocate space for a copy of the section header table in internal form. */ if (i_ehdrp->e_shnum != 0) { Elf_Internal_Shdr *shdrp; unsigned int num_sec; amt = sizeof (*i_shdrp) * i_ehdrp->e_shnum; i_shdrp = bfd_alloc (abfd, amt); if (!i_shdrp) goto got_no_match; num_sec = i_ehdrp->e_shnum; if (num_sec > SHN_LORESERVE) num_sec += SHN_HIRESERVE + 1 - SHN_LORESERVE; elf_numsections (abfd) = num_sec; amt = sizeof (i_shdrp) * num_sec; elf_elfsections (abfd) = bfd_alloc (abfd, amt); if (!elf_elfsections (abfd)) goto got_no_match; memcpy (i_shdrp, &i_shdr, sizeof (*i_shdrp)); shdrp = i_shdrp; shindex = 0; if (num_sec > SHN_LORESERVE) { for ( ; shindex < SHN_LORESERVE; shindex++) elf_elfsections (abfd)[shindex] = shdrp++; for ( ; shindex < SHN_HIRESERVE + 1; shindex++) elf_elfsections (abfd)[shindex] = i_shdrp; } for ( ; shindex < num_sec; shindex++) elf_elfsections (abfd)[shindex] = shdrp++; /* Read in the rest of the section header table and convert it to internal form. */ for (shindex = 1; shindex < i_ehdrp->e_shnum; shindex++) { if (bfd_bread (&x_shdr, sizeof x_shdr, abfd) != sizeof (x_shdr)) goto got_no_match; elf_swap_shdr_in (abfd, &x_shdr, i_shdrp + shindex); /* Sanity check sh_link and sh_info. */ if (! valid_section_index_p (i_shdrp[shindex].sh_link, num_sec)) goto got_wrong_format_error; if (((i_shdrp[shindex].sh_flags & SHF_INFO_LINK) || i_shdrp[shindex].sh_type == SHT_RELA || i_shdrp[shindex].sh_type == SHT_REL) && ! valid_section_index_p (i_shdrp[shindex].sh_info, num_sec)) goto got_wrong_format_error; /* If the section is loaded, but not page aligned, clear D_PAGED. */ if (i_shdrp[shindex].sh_size != 0 && (i_shdrp[shindex].sh_flags & SHF_ALLOC) != 0 && i_shdrp[shindex].sh_type != SHT_NOBITS && (((i_shdrp[shindex].sh_addr - i_shdrp[shindex].sh_offset) % ebd->minpagesize) != 0)) abfd->flags &= ~D_PAGED; } } /* A further sanity check. */ if (i_ehdrp->e_shnum != 0) { if (! valid_section_index_p (i_ehdrp->e_shstrndx, elf_numsections (abfd))) { /* PR 2257: We used to just goto got_wrong_format_error here but there are binaries in existance for which this test will prevent the binutils from working with them at all. So we are kind, and reset the string index value to 0 so that at least some processing can be done. */ i_ehdrp->e_shstrndx = SHN_UNDEF; _bfd_error_handler (_("warning: %s has a corrupt string table index - ignoring"), abfd->filename); } } else if (i_ehdrp->e_shstrndx != SHN_UNDEF) goto got_wrong_format_error; /* Read in the program headers. */ if (i_ehdrp->e_phnum == 0) elf_tdata (abfd)->phdr = NULL; else { Elf_Internal_Phdr *i_phdr; unsigned int i; amt = i_ehdrp->e_phnum * sizeof (Elf_Internal_Phdr); elf_tdata (abfd)->phdr = bfd_alloc (abfd, amt); if (elf_tdata (abfd)->phdr == NULL) goto got_no_match; if (bfd_seek (abfd, (file_ptr) i_ehdrp->e_phoff, SEEK_SET) != 0) goto got_no_match; i_phdr = elf_tdata (abfd)->phdr; for (i = 0; i < i_ehdrp->e_phnum; i++, i_phdr++) { Elf_External_Phdr x_phdr; if (bfd_bread (&x_phdr, sizeof x_phdr, abfd) != sizeof x_phdr) goto got_no_match; elf_swap_phdr_in (abfd, &x_phdr, i_phdr); } } if (i_ehdrp->e_shstrndx != 0 && i_ehdrp->e_shoff != 0) { unsigned int num_sec; /* 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. */ num_sec = elf_numsections (abfd); for (shindex = 1; shindex < num_sec; shindex++) { if (! bfd_section_from_shdr (abfd, shindex)) goto got_no_match; if (shindex == SHN_LORESERVE - 1) shindex += SHN_HIRESERVE + 1 - SHN_LORESERVE; } /* Set up ELF sections for SHF_GROUP and SHF_LINK_ORDER. */ if (! _bfd_elf_setup_sections (abfd)) goto got_wrong_format_error; } /* Let the backend double check the format and override global information. */ if (ebd->elf_backend_object_p) { if (! (*ebd->elf_backend_object_p) (abfd)) goto got_wrong_format_error; } /* Remember the entry point specified in the ELF file header. */ bfd_set_start_address (abfd, i_ehdrp->e_entry); /* If we have created any reloc sections that are associated with debugging sections, mark the reloc sections as debugging as well. */ for (s = abfd->sections; s != NULL; s = s->next) { if ((elf_section_data (s)->this_hdr.sh_type == SHT_REL || elf_section_data (s)->this_hdr.sh_type == SHT_RELA) && elf_section_data (s)->this_hdr.sh_info > 0) { unsigned long targ_index; asection *targ_sec; targ_index = elf_section_data (s)->this_hdr.sh_info; targ_sec = bfd_section_from_elf_index (abfd, targ_index); if (targ_sec != NULL && (targ_sec->flags & SEC_DEBUGGING) != 0) s->flags |= SEC_DEBUGGING; } } bfd_preserve_finish (abfd, &preserve); return target; got_wrong_format_error: /* There is way too much undoing of half-known state here. The caller, bfd_check_format_matches, really shouldn't iterate on live bfd's to check match/no-match like it does. We have to rely on that a call to bfd_default_set_arch_mach with the previously known mach, undoes what was done by the first bfd_default_set_arch_mach (with mach 0) here. For this to work, only elf-data and the mach may be changed by the target-specific elf_backend_object_p function. Note that saving the whole bfd here and restoring it would be even worse; the first thing you notice is that the cached bfd file position gets out of sync. */ bfd_set_error (bfd_error_wrong_format); got_no_match: if (preserve.marker != NULL) bfd_preserve_restore (abfd, &preserve); return NULL; } /* ELF .o/exec file writing */ /* Write out the relocs. */ void elf_write_relocs (bfd *abfd, asection *sec, void *data) { bfd_boolean *failedp = data; Elf_Internal_Shdr *rela_hdr; bfd_vma addr_offset; void (*swap_out) (bfd *, const Elf_Internal_Rela *, bfd_byte *); size_t extsize; bfd_byte *dst_rela; unsigned int idx; asymbol *last_sym; int last_sym_idx; /* If we have already failed, don't do anything. */ if (*failedp) return; 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; /* If we have opened an existing file for update, reloc_count may be set even though we are not linking. In that case we have nothing to do. */ if (sec->orelocation == NULL) return; rela_hdr = &elf_section_data (sec)->rel_hdr; rela_hdr->sh_size = rela_hdr->sh_entsize * sec->reloc_count; rela_hdr->contents = bfd_alloc (abfd, rela_hdr->sh_size); if (rela_hdr->contents == NULL) { *failedp = TRUE; return; } /* Figure out whether the relocations are RELA or REL relocations. */ if (rela_hdr->sh_type == SHT_RELA) { swap_out = elf_swap_reloca_out; extsize = sizeof (Elf_External_Rela); } else if (rela_hdr->sh_type == SHT_REL) { swap_out = elf_swap_reloc_out; extsize = sizeof (Elf_External_Rel); } else /* Every relocation section should be either an SHT_RELA or an SHT_REL section. */ abort (); /* 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. */ addr_offset = 0; if ((abfd->flags & (EXEC_P | DYNAMIC)) != 0) addr_offset = sec->vma; /* orelocation has the data, reloc_count has the count... */ last_sym = 0; last_sym_idx = 0; dst_rela = rela_hdr->contents; for (idx = 0; idx < sec->reloc_count; idx++, dst_rela += extsize) { Elf_Internal_Rela src_rela; arelent *ptr; asymbol *sym; int n; ptr = sec->orelocation[idx]; sym = *ptr->sym_ptr_ptr; if (sym == last_sym) n = last_sym_idx; else if (bfd_is_abs_section (sym->section) && sym->value == 0) n = STN_UNDEF; else { last_sym = sym; n = _bfd_elf_symbol_from_bfd_symbol (abfd, &sym); if (n < 0) { *failedp = TRUE; return; } last_sym_idx = n; } if ((*ptr->sym_ptr_ptr)->the_bfd != NULL && (*ptr->sym_ptr_ptr)->the_bfd->xvec != abfd->xvec && ! _bfd_elf_validate_reloc (abfd, ptr)) { *failedp = TRUE; return; } src_rela.r_offset = ptr->address + addr_offset; src_rela.r_info = ELF_R_INFO (n, ptr->howto->type); src_rela.r_addend = ptr->addend; (*swap_out) (abfd, &src_rela, dst_rela); } } /* Write out the program headers. */ int elf_write_out_phdrs (bfd *abfd, const Elf_Internal_Phdr *phdr, unsigned int count) { while (count--) { Elf_External_Phdr extphdr; elf_swap_phdr_out (abfd, phdr, &extphdr); if (bfd_bwrite (&extphdr, sizeof (Elf_External_Phdr), abfd) != sizeof (Elf_External_Phdr)) return -1; phdr++; } return 0; } /* Write out the section headers and the ELF file header. */ bfd_boolean elf_write_shdrs_and_ehdr (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; bfd_size_type amt; i_ehdrp = elf_elfheader (abfd); i_shdrp = elf_elfsections (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); amt = sizeof (x_ehdr); if (bfd_seek (abfd, (file_ptr) 0, SEEK_SET) != 0 || bfd_bwrite (&x_ehdr, amt, abfd) != amt) return FALSE; /* Some fields in the first section header handle overflow of ehdr fields. */ if (i_ehdrp->e_shnum >= SHN_LORESERVE) i_shdrp[0]->sh_size = i_ehdrp->e_shnum; if (i_ehdrp->e_shstrndx >= SHN_LORESERVE) i_shdrp[0]->sh_link = i_ehdrp->e_shstrndx; /* at this point we've concocted all the ELF sections... */ amt = i_ehdrp->e_shnum; amt *= sizeof (*x_shdrp); x_shdrp = bfd_alloc (abfd, amt); if (!x_shdrp) return FALSE; for (count = 0; count < i_ehdrp->e_shnum; i_shdrp++, count++) { #if DEBUG & 2 elf_debug_section (count, *i_shdrp); #endif elf_swap_shdr_out (abfd, *i_shdrp, x_shdrp + count); if (count == SHN_LORESERVE - 1) i_shdrp += SHN_HIRESERVE + 1 - SHN_LORESERVE; } if (bfd_seek (abfd, (file_ptr) i_ehdrp->e_shoff, SEEK_SET) != 0 || bfd_bwrite (x_shdrp, amt, abfd) != amt) return FALSE; /* need to dump the string table too... */ return TRUE; } bfd_boolean elf_checksum_contents (bfd *abfd, void (*process) (const void *, size_t, void *), void *arg) { Elf_Internal_Ehdr *i_ehdrp = elf_elfheader (abfd); Elf_Internal_Shdr **i_shdrp = elf_elfsections (abfd); Elf_Internal_Phdr *i_phdrp = elf_tdata (abfd)->phdr; unsigned int count, num; { Elf_External_Ehdr x_ehdr; Elf_Internal_Ehdr i_ehdr; i_ehdr = *i_ehdrp; i_ehdr.e_phoff = i_ehdr.e_shoff = 0; elf_swap_ehdr_out (abfd, &i_ehdr, &x_ehdr); (*process) (&x_ehdr, sizeof x_ehdr, arg); } num = i_ehdrp->e_phnum; for (count = 0; count < num; count++) { Elf_External_Phdr x_phdr; elf_swap_phdr_out (abfd, &i_phdrp[count], &x_phdr); (*process) (&x_phdr, sizeof x_phdr, arg); } num = elf_numsections (abfd); for (count = 0; count < num; count++) { Elf_Internal_Shdr i_shdr; Elf_External_Shdr x_shdr; i_shdr = *i_shdrp[count]; i_shdr.sh_offset = 0; elf_swap_shdr_out (abfd, &i_shdr, &x_shdr); (*process) (&x_shdr, sizeof x_shdr, arg); if (i_shdr.contents) (*process) (i_shdr.contents, i_shdr.sh_size, arg); } return TRUE; } long elf_slurp_symbol_table (bfd *abfd, asymbol **symptrs, bfd_boolean dynamic) { Elf_Internal_Shdr *hdr; Elf_Internal_Shdr *verhdr; unsigned 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 *isym; Elf_Internal_Sym *isymend; Elf_Internal_Sym *isymbuf = NULL; Elf_External_Versym *xver; Elf_External_Versym *xverbuf = NULL; const struct elf_backend_data *ebd; bfd_size_type amt; /* 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)->symtab_hdr; verhdr = NULL; } else { hdr = &elf_tdata (abfd)->dynsymtab_hdr; if (elf_dynversym (abfd) == 0) verhdr = NULL; else verhdr = &elf_tdata (abfd)->dynversym_hdr; if ((elf_tdata (abfd)->dynverdef_section != 0 && elf_tdata (abfd)->verdef == NULL) || (elf_tdata (abfd)->dynverref_section != 0 && elf_tdata (abfd)->verref == NULL)) { if (!_bfd_elf_slurp_version_tables (abfd, FALSE)) return -1; } } ebd = get_elf_backend_data (abfd); symcount = hdr->sh_size / sizeof (Elf_External_Sym); if (symcount == 0) sym = symbase = NULL; else { isymbuf = bfd_elf_get_elf_syms (abfd, hdr, symcount, 0, NULL, NULL, NULL); if (isymbuf == NULL) return -1; amt = symcount; amt *= sizeof (elf_symbol_type); symbase = bfd_zalloc (abfd, amt); if (symbase == (elf_symbol_type *) NULL) goto error_return; /* Read the raw ELF version symbol information. */ if (verhdr != NULL && verhdr->sh_size / sizeof (Elf_External_Versym) != symcount) { (*_bfd_error_handler) (_("%s: version count (%ld) does not match symbol count (%ld)"), abfd->filename, (long) (verhdr->sh_size / sizeof (Elf_External_Versym)), symcount); /* Slurp in the symbols without the version information, since that is more helpful than just quitting. */ verhdr = NULL; } if (verhdr != NULL) { if (bfd_seek (abfd, verhdr->sh_offset, SEEK_SET) != 0) goto error_return; xverbuf = bfd_malloc (verhdr->sh_size); if (xverbuf == NULL && verhdr->sh_size != 0) goto error_return; if (bfd_bread (xverbuf, verhdr->sh_size, abfd) != verhdr->sh_size) goto error_return; } /* Skip first symbol, which is a null dummy. */ xver = xverbuf; if (xver != NULL) ++xver; isymend = isymbuf + symcount; for (isym = isymbuf + 1, sym = symbase; isym < isymend; isym++, sym++) { memcpy (&sym->internal_elf_sym, isym, sizeof (Elf_Internal_Sym)); sym->symbol.the_bfd = abfd; sym->symbol.name = bfd_elf_sym_name (abfd, hdr, isym, NULL); sym->symbol.value = isym->st_value; if (isym->st_shndx == SHN_UNDEF) { sym->symbol.section = bfd_und_section_ptr; } else if (isym->st_shndx < SHN_LORESERVE || isym->st_shndx > SHN_HIRESERVE) { sym->symbol.section = bfd_section_from_elf_index (abfd, isym->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 (isym->st_shndx == SHN_ABS) { sym->symbol.section = bfd_abs_section_ptr; } else if (isym->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 = isym->st_size; } else sym->symbol.section = bfd_abs_section_ptr; /* If this is a relocatable file, then the symbol value is already section relative. */ if ((abfd->flags & (EXEC_P | DYNAMIC)) != 0) sym->symbol.value -= sym->symbol.section->vma; switch (ELF_ST_BIND (isym->st_info)) { case STB_LOCAL: sym->symbol.flags |= BSF_LOCAL; break; case STB_GLOBAL: if (isym->st_shndx != SHN_UNDEF && isym->st_shndx != SHN_COMMON) sym->symbol.flags |= BSF_GLOBAL; break; case STB_WEAK: sym->symbol.flags |= BSF_WEAK; break; } switch (ELF_ST_TYPE (isym->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; case STT_COMMON: /* FIXME: Do we have to put the size field into the value field as we do with symbols in SHN_COMMON sections (see above) ? */ /* Fall through. */ case STT_OBJECT: sym->symbol.flags |= BSF_OBJECT; break; case STT_TLS: sym->symbol.flags |= BSF_THREAD_LOCAL; break; case STT_RELC: sym->symbol.flags |= BSF_RELC; break; case STT_SRELC: sym->symbol.flags |= BSF_SRELC; break; } if (dynamic) sym->symbol.flags |= BSF_DYNAMIC; if (xver != NULL) { Elf_Internal_Versym iversym; _bfd_elf_swap_versym_in (abfd, xver, &iversym); sym->version = iversym.vs_vers; xver++; } /* Do some backend-specific processing on this symbol. */ if (ebd->elf_backend_symbol_processing) (*ebd->elf_backend_symbol_processing) (abfd, &sym->symbol); } } /* Do some backend-specific processing on this symbol table. */ 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 (xverbuf != NULL) free (xverbuf); if (isymbuf != NULL && hdr->contents != (unsigned char *) isymbuf) free (isymbuf); return symcount; error_return: if (xverbuf != NULL) free (xverbuf); if (isymbuf != NULL && hdr->contents != (unsigned char *) isymbuf) free (isymbuf); return -1; } /* Read relocations for ASECT from REL_HDR. There are RELOC_COUNT of them. */ static bfd_boolean elf_slurp_reloc_table_from_section (bfd *abfd, asection *asect, Elf_Internal_Shdr *rel_hdr, bfd_size_type reloc_count, arelent *relents, asymbol **symbols, bfd_boolean dynamic) { const struct elf_backend_data * const ebd = get_elf_backend_data (abfd); void *allocated = NULL; bfd_byte *native_relocs; arelent *relent; unsigned int i; int entsize; unsigned int symcount; allocated = bfd_malloc (rel_hdr->sh_size); if (allocated == NULL) goto error_return; if (bfd_seek (abfd, rel_hdr->sh_offset, SEEK_SET) != 0 || (bfd_bread (allocated, rel_hdr->sh_size, abfd) != rel_hdr->sh_size)) goto error_return; native_relocs = allocated; entsize = rel_hdr->sh_entsize; BFD_ASSERT (entsize == sizeof (Elf_External_Rel) || entsize == sizeof (Elf_External_Rela)); if (dynamic) symcount = bfd_get_dynamic_symcount (abfd); else symcount = bfd_get_symcount (abfd); for (i = 0, relent = relents; i < reloc_count; i++, relent++, native_relocs += entsize) { Elf_Internal_Rela rela; if (entsize == sizeof (Elf_External_Rela)) elf_swap_reloca_in (abfd, native_relocs, &rela); else elf_swap_reloc_in (abfd, native_relocs, &rela); /* 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 normal BFD reloc is always section relative, and the address of a dynamic reloc is absolute.. */ if ((abfd->flags & (EXEC_P | DYNAMIC)) == 0 || dynamic) 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 if (ELF_R_SYM (rela.r_info) > symcount) { (*_bfd_error_handler) (_("%s(%s): relocation %d has invalid symbol index %ld"), abfd->filename, asect->name, i, ELF_R_SYM (rela.r_info)); relent->sym_ptr_ptr = bfd_abs_section.symbol_ptr_ptr; } else { asymbol **ps; ps = symbols + ELF_R_SYM (rela.r_info) - 1; relent->sym_ptr_ptr = ps; } relent->addend = rela.r_addend; if ((entsize == sizeof (Elf_External_Rela) && ebd->elf_info_to_howto != NULL) || ebd->elf_info_to_howto_rel == NULL) (*ebd->elf_info_to_howto) (abfd, relent, &rela); else (*ebd->elf_info_to_howto_rel) (abfd, relent, &rela); } if (allocated != NULL) free (allocated); return TRUE; error_return: if (allocated != NULL) free (allocated); return FALSE; } /* Read in and swap the external relocs. */ bfd_boolean elf_slurp_reloc_table (bfd *abfd, asection *asect, asymbol **symbols, bfd_boolean dynamic) { struct bfd_elf_section_data * const d = elf_section_data (asect); Elf_Internal_Shdr *rel_hdr; Elf_Internal_Shdr *rel_hdr2; bfd_size_type reloc_count; bfd_size_type reloc_count2; arelent *relents; bfd_size_type amt; if (asect->relocation != NULL) return TRUE; if (! dynamic) { if ((asect->flags & SEC_RELOC) == 0 || asect->reloc_count == 0) return TRUE; rel_hdr = &d->rel_hdr; reloc_count = NUM_SHDR_ENTRIES (rel_hdr); rel_hdr2 = d->rel_hdr2; reloc_count2 = (rel_hdr2 ? NUM_SHDR_ENTRIES (rel_hdr2) : 0); BFD_ASSERT (asect->reloc_count == reloc_count + reloc_count2); BFD_ASSERT (asect->rel_filepos == rel_hdr->sh_offset || (rel_hdr2 && asect->rel_filepos == rel_hdr2->sh_offset)); } else { /* Note that ASECT->RELOC_COUNT tends not to be accurate in this case because relocations against this section may use the dynamic symbol table, and in that case bfd_section_from_shdr in elf.c does not update the RELOC_COUNT. */ if (asect->size == 0) return TRUE; rel_hdr = &d->this_hdr; reloc_count = NUM_SHDR_ENTRIES (rel_hdr); rel_hdr2 = NULL; reloc_count2 = 0; } amt = (reloc_count + reloc_count2) * sizeof (arelent); relents = bfd_alloc (abfd, amt); if (relents == NULL) return FALSE; if (!elf_slurp_reloc_table_from_section (abfd, asect, rel_hdr, reloc_count, relents, symbols, dynamic)) return FALSE; if (rel_hdr2 && !elf_slurp_reloc_table_from_section (abfd, asect, rel_hdr2, reloc_count2, relents + reloc_count, symbols, dynamic)) return FALSE; asect->relocation = relents; return TRUE; } #if DEBUG & 2 static void elf_debug_section (int num, Elf_Internal_Shdr *hdr) { fprintf (stderr, "\nSection#%d '%s' 0x%.8lx\n", num, hdr->bfd_section != NULL ? hdr->bfd_section->name : "", (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); fflush (stderr); } #endif #if DEBUG & 1 static void elf_debug_file (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 /* Create a new BFD as if by bfd_openr. Rather than opening a file, reconstruct an ELF file by reading the segments out of remote memory based on the ELF file header at EHDR_VMA and the ELF program headers it points to. If not null, *LOADBASEP is filled in with the difference between the VMAs from which the segments were read, and the VMAs the file headers (and hence BFD's idea of each section's VMA) put them at. The function TARGET_READ_MEMORY is called to copy LEN bytes from the remote memory at target address VMA into the local buffer at MYADDR; it should return zero on success or an `errno' code on failure. TEMPL must be a BFD for a target with the word size and byte order found in the remote memory. */ bfd * NAME(_bfd_elf,bfd_from_remote_memory) (bfd *templ, bfd_vma ehdr_vma, bfd_vma *loadbasep, int (*target_read_memory) (bfd_vma, bfd_byte *, int)) { Elf_External_Ehdr x_ehdr; /* Elf file header, external form */ Elf_Internal_Ehdr i_ehdr; /* Elf file header, internal form */ Elf_External_Phdr *x_phdrs; Elf_Internal_Phdr *i_phdrs, *last_phdr; bfd *nbfd; struct bfd_in_memory *bim; int contents_size; bfd_byte *contents; int err; unsigned int i; bfd_vma loadbase; bfd_boolean loadbase_set; /* Read in the ELF header in external format. */ err = target_read_memory (ehdr_vma, (bfd_byte *) &x_ehdr, sizeof x_ehdr); if (err) { bfd_set_error (bfd_error_system_call); errno = err; 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. */ if (! elf_file_p (&x_ehdr) || x_ehdr.e_ident[EI_VERSION] != EV_CURRENT || x_ehdr.e_ident[EI_CLASS] != ELFCLASS) { bfd_set_error (bfd_error_wrong_format); return NULL; } /* Check that file's byte order matches xvec's */ switch (x_ehdr.e_ident[EI_DATA]) { case ELFDATA2MSB: /* Big-endian */ if (! bfd_header_big_endian (templ)) { bfd_set_error (bfd_error_wrong_format); return NULL; } break; case ELFDATA2LSB: /* Little-endian */ if (! bfd_header_little_endian (templ)) { bfd_set_error (bfd_error_wrong_format); return NULL; } break; case ELFDATANONE: /* No data encoding specified */ default: /* Unknown data encoding specified */ bfd_set_error (bfd_error_wrong_format); return NULL; } elf_swap_ehdr_in (templ, &x_ehdr, &i_ehdr); /* The file header tells where to find the program headers. These are what we use to actually choose what to read. */ if (i_ehdr.e_phentsize != sizeof (Elf_External_Phdr) || i_ehdr.e_phnum == 0) { bfd_set_error (bfd_error_wrong_format); return NULL; } x_phdrs = bfd_malloc (i_ehdr.e_phnum * (sizeof *x_phdrs + sizeof *i_phdrs)); if (x_phdrs == NULL) { bfd_set_error (bfd_error_no_memory); return NULL; } err = target_read_memory (ehdr_vma + i_ehdr.e_phoff, (bfd_byte *) x_phdrs, i_ehdr.e_phnum * sizeof x_phdrs[0]); if (err) { free (x_phdrs); bfd_set_error (bfd_error_system_call); errno = err; return NULL; } i_phdrs = (Elf_Internal_Phdr *) &x_phdrs[i_ehdr.e_phnum]; contents_size = 0; last_phdr = NULL; loadbase = ehdr_vma; loadbase_set = FALSE; for (i = 0; i < i_ehdr.e_phnum; ++i) { elf_swap_phdr_in (templ, &x_phdrs[i], &i_phdrs[i]); if (i_phdrs[i].p_type == PT_LOAD) { bfd_vma segment_end; segment_end = (i_phdrs[i].p_offset + i_phdrs[i].p_filesz + i_phdrs[i].p_align - 1) & -i_phdrs[i].p_align; if (segment_end > (bfd_vma) contents_size) contents_size = segment_end; /* LOADADDR is the `Base address' from the gELF specification: `lowest p_vaddr value for a PT_LOAD segment' is P_VADDR from the first PT_LOAD as PT_LOADs are ordered by P_VADDR. */ if (!loadbase_set && (i_phdrs[i].p_offset & -i_phdrs[i].p_align) == 0) { loadbase = ehdr_vma - (i_phdrs[i].p_vaddr & -i_phdrs[i].p_align); loadbase_set = TRUE; } last_phdr = &i_phdrs[i]; } } if (last_phdr == NULL) { /* There were no PT_LOAD segments, so we don't have anything to read. */ free (x_phdrs); bfd_set_error (bfd_error_wrong_format); return NULL; } /* Trim the last segment so we don't bother with zeros in the last page that are off the end of the file. However, if the extra bit in that page includes the section headers, keep them. */ if ((bfd_vma) contents_size > last_phdr->p_offset + last_phdr->p_filesz && (bfd_vma) contents_size >= (i_ehdr.e_shoff + i_ehdr.e_shnum * i_ehdr.e_shentsize)) { contents_size = last_phdr->p_offset + last_phdr->p_filesz; if ((bfd_vma) contents_size < (i_ehdr.e_shoff + i_ehdr.e_shnum * i_ehdr.e_shentsize)) contents_size = i_ehdr.e_shoff + i_ehdr.e_shnum * i_ehdr.e_shentsize; } else contents_size = last_phdr->p_offset + last_phdr->p_filesz; /* Now we know the size of the whole image we want read in. */ contents = bfd_zmalloc (contents_size); if (contents == NULL) { free (x_phdrs); bfd_set_error (bfd_error_no_memory); return NULL; } for (i = 0; i < i_ehdr.e_phnum; ++i) if (i_phdrs[i].p_type == PT_LOAD) { bfd_vma start = i_phdrs[i].p_offset & -i_phdrs[i].p_align; bfd_vma end = (i_phdrs[i].p_offset + i_phdrs[i].p_filesz + i_phdrs[i].p_align - 1) & -i_phdrs[i].p_align; if (end > (bfd_vma) contents_size) end = contents_size; err = target_read_memory ((loadbase + i_phdrs[i].p_vaddr) & -i_phdrs[i].p_align, contents + start, end - start); if (err) { free (x_phdrs); free (contents); bfd_set_error (bfd_error_system_call); errno = err; return NULL; } } free (x_phdrs); /* If the segments visible in memory didn't include the section headers, then clear them from the file header. */ if ((bfd_vma) contents_size < (i_ehdr.e_shoff + i_ehdr.e_shnum * i_ehdr.e_shentsize)) { memset (&x_ehdr.e_shoff, 0, sizeof x_ehdr.e_shoff); memset (&x_ehdr.e_shnum, 0, sizeof x_ehdr.e_shnum); memset (&x_ehdr.e_shstrndx, 0, sizeof x_ehdr.e_shstrndx); } /* This will normally have been in the first PT_LOAD segment. But it conceivably could be missing, and we might have just changed it. */ memcpy (contents, &x_ehdr, sizeof x_ehdr); /* Now we have a memory image of the ELF file contents. Make a BFD. */ bim = bfd_malloc (sizeof (struct bfd_in_memory)); if (bim == NULL) { free (contents); bfd_set_error (bfd_error_no_memory); return NULL; } nbfd = _bfd_new_bfd (); if (nbfd == NULL) { free (bim); free (contents); bfd_set_error (bfd_error_no_memory); return NULL; } nbfd->filename = "<in-memory>"; nbfd->xvec = templ->xvec; bim->size = contents_size; bim->buffer = contents; nbfd->iostream = bim; nbfd->flags = BFD_IN_MEMORY; nbfd->direction = read_direction; nbfd->mtime = time (NULL); nbfd->mtime_set = TRUE; if (loadbasep) *loadbasep = loadbase; return nbfd; } #include "elfcore.h" /* Size-dependent data and functions. */ const struct elf_size_info NAME(_bfd_elf,size_info) = { sizeof (Elf_External_Ehdr), sizeof (Elf_External_Phdr), sizeof (Elf_External_Shdr), sizeof (Elf_External_Rel), sizeof (Elf_External_Rela), sizeof (Elf_External_Sym), sizeof (Elf_External_Dyn), sizeof (Elf_External_Note), 4, 1, ARCH_SIZE, LOG_FILE_ALIGN, ELFCLASS, EV_CURRENT, elf_write_out_phdrs, elf_write_shdrs_and_ehdr, elf_checksum_contents, elf_write_relocs, elf_swap_symbol_in, elf_swap_symbol_out, elf_slurp_reloc_table, elf_slurp_symbol_table, elf_swap_dyn_in, elf_swap_dyn_out, elf_swap_reloc_in, elf_swap_reloc_out, elf_swap_reloca_in, elf_swap_reloca_out };
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