/* Motorola MCore specific support for 32-bit ELF Copyright (C) 1994-2016 Free Software Foundation, Inc. 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. */ /* This file is based on a preliminary RCE ELF ABI. The information may not match the final RCE ELF ABI. */ #include "sysdep.h" #include "bfd.h" #include "bfdlink.h" #include "libbfd.h" #include "elf-bfd.h" #include "elf/mcore.h" #include <assert.h> /* RELA relocs are used here... */ /* Function to set whether a module needs the -mrelocatable bit set. */ static bfd_boolean mcore_elf_set_private_flags (bfd * abfd, flagword flags) { BFD_ASSERT (! elf_flags_init (abfd) || elf_elfheader (abfd)->e_flags == flags); elf_elfheader (abfd)->e_flags = flags; elf_flags_init (abfd) = TRUE; return TRUE; } /* Merge backend specific data from an object file to the output object file when linking. */ static bfd_boolean mcore_elf_merge_private_bfd_data (bfd * ibfd, bfd * obfd) { flagword old_flags; flagword new_flags; /* Check if we have the same endianness. */ if (! _bfd_generic_verify_endian_match (ibfd, obfd)) return FALSE; if ( bfd_get_flavour (ibfd) != bfd_target_elf_flavour || bfd_get_flavour (obfd) != bfd_target_elf_flavour) return TRUE; new_flags = elf_elfheader (ibfd)->e_flags; old_flags = elf_elfheader (obfd)->e_flags; if (! elf_flags_init (obfd)) { /* First call, no flags set. */ elf_flags_init (obfd) = TRUE; elf_elfheader (obfd)->e_flags = new_flags; } else if (new_flags == old_flags) /* Compatible flags are OK. */ ; else { /* FIXME */ } return TRUE; } /* Don't pretend we can deal with unsupported relocs. */ static bfd_reloc_status_type mcore_elf_unsupported_reloc (bfd * abfd, arelent * reloc_entry, asymbol * symbol ATTRIBUTE_UNUSED, void * data ATTRIBUTE_UNUSED, asection * input_section ATTRIBUTE_UNUSED, bfd * output_bfd ATTRIBUTE_UNUSED, char ** error_message ATTRIBUTE_UNUSED) { BFD_ASSERT (reloc_entry->howto != (reloc_howto_type *)0); _bfd_error_handler (_("%B: Relocation %s (%d) is not currently supported.\n"), abfd, reloc_entry->howto->name, reloc_entry->howto->type); return bfd_reloc_notsupported; } static reloc_howto_type * mcore_elf_howto_table [(int) R_MCORE_max]; static reloc_howto_type mcore_elf_howto_raw[] = { /* This reloc does nothing. */ HOWTO (R_MCORE_NONE, /* type */ 0, /* rightshift */ 3, /* size (0 = byte, 1 = short, 2 = long) */ 0, /* bitsize */ FALSE, /* pc_relative */ 0, /* bitpos */ complain_overflow_dont, /* complain_on_overflow */ NULL, /* special_function */ "R_MCORE_NONE", /* name */ FALSE, /* partial_inplace */ 0, /* src_mask */ 0, /* dst_mask */ FALSE), /* pcrel_offset */ /* A standard 32 bit relocation. */ HOWTO (R_MCORE_ADDR32, /* type */ 0, /* rightshift */ 2, /* size (0 = byte, 1 = short, 2 = long) */ 32, /* bitsize */ FALSE, /* pc_relative */ 0, /* bitpos */ complain_overflow_bitfield, /* complain_on_overflow */ bfd_elf_generic_reloc, /* special_function */ "ADDR32", /* name *//* For compatibility with coff/pe port. */ FALSE, /* partial_inplace */ 0x0, /* src_mask */ 0xffffffff, /* dst_mask */ FALSE), /* pcrel_offset */ /* 8 bits + 2 zero bits; jmpi/jsri/lrw instructions. Should not appear in object files. */ HOWTO (R_MCORE_PCRELIMM8BY4, /* type */ 2, /* rightshift */ 1, /* size (0 = byte, 1 = short, 2 = long) */ 8, /* bitsize */ TRUE, /* pc_relative */ 0, /* bitpos */ complain_overflow_bitfield, /* complain_on_overflow */ mcore_elf_unsupported_reloc, /* special_function */ "R_MCORE_PCRELIMM8BY4",/* name */ FALSE, /* partial_inplace */ 0, /* src_mask */ 0, /* dst_mask */ TRUE), /* pcrel_offset */ /* bsr/bt/bf/br instructions; 11 bits + 1 zero bit Span 2k instructions == 4k bytes. Only useful pieces at the relocated address are the opcode (5 bits) */ HOWTO (R_MCORE_PCRELIMM11BY2,/* type */ 1, /* rightshift */ 1, /* size (0 = byte, 1 = short, 2 = long) */ 11, /* bitsize */ TRUE, /* pc_relative */ 0, /* bitpos */ complain_overflow_signed, /* complain_on_overflow */ bfd_elf_generic_reloc, /* special_function */ "R_MCORE_PCRELIMM11BY2",/* name */ FALSE, /* partial_inplace */ 0x0, /* src_mask */ 0x7ff, /* dst_mask */ TRUE), /* pcrel_offset */ /* 4 bits + 1 zero bit; 'loopt' instruction only; unsupported. */ HOWTO (R_MCORE_PCRELIMM4BY2, /* type */ 1, /* rightshift */ 1, /* size (0 = byte, 1 = short, 2 = long) */ 4, /* bitsize */ TRUE, /* pc_relative */ 0, /* bitpos */ complain_overflow_bitfield, /* complain_on_overflow */ mcore_elf_unsupported_reloc,/* special_function */ "R_MCORE_PCRELIMM4BY2",/* name */ FALSE, /* partial_inplace */ 0, /* src_mask */ 0, /* dst_mask */ TRUE), /* pcrel_offset */ /* 32-bit pc-relative. Eventually this will help support PIC code. */ HOWTO (R_MCORE_PCREL32, /* type */ 0, /* rightshift */ 2, /* size (0 = byte, 1 = short, 2 = long) */ 32, /* bitsize */ TRUE, /* pc_relative */ 0, /* bitpos */ complain_overflow_bitfield, /* complain_on_overflow */ bfd_elf_generic_reloc, /* special_function */ "R_MCORE_PCREL32", /* name */ FALSE, /* partial_inplace */ 0x0, /* src_mask */ 0xffffffff, /* dst_mask */ TRUE), /* pcrel_offset */ /* Like PCRELIMM11BY2, this relocation indicates that there is a 'jsri' at the specified address. There is a separate relocation entry for the literal pool entry that it references, but we might be able to change the jsri to a bsr if the target turns out to be close enough [even though we won't reclaim the literal pool entry, we'll get some runtime efficiency back]. Note that this is a relocation that we are allowed to safely ignore. */ HOWTO (R_MCORE_PCRELJSR_IMM11BY2,/* type */ 1, /* rightshift */ 1, /* size (0 = byte, 1 = short, 2 = long) */ 11, /* bitsize */ TRUE, /* pc_relative */ 0, /* bitpos */ complain_overflow_signed, /* complain_on_overflow */ bfd_elf_generic_reloc, /* special_function */ "R_MCORE_PCRELJSR_IMM11BY2", /* name */ FALSE, /* partial_inplace */ 0x0, /* src_mask */ 0x7ff, /* dst_mask */ TRUE), /* pcrel_offset */ /* GNU extension to record C++ vtable hierarchy. */ HOWTO (R_MCORE_GNU_VTINHERIT, /* type */ 0, /* rightshift */ 2, /* size (0 = byte, 1 = short, 2 = long) */ 0, /* bitsize */ FALSE, /* pc_relative */ 0, /* bitpos */ complain_overflow_dont, /* complain_on_overflow */ NULL, /* special_function */ "R_MCORE_GNU_VTINHERIT", /* name */ FALSE, /* partial_inplace */ 0, /* src_mask */ 0, /* dst_mask */ FALSE), /* pcrel_offset */ /* GNU extension to record C++ vtable member usage. */ HOWTO (R_MCORE_GNU_VTENTRY, /* type */ 0, /* rightshift */ 2, /* size (0 = byte, 1 = short, 2 = long) */ 0, /* bitsize */ FALSE, /* pc_relative */ 0, /* bitpos */ complain_overflow_dont,/* complain_on_overflow */ _bfd_elf_rel_vtable_reloc_fn, /* special_function */ "R_MCORE_GNU_VTENTRY", /* name */ FALSE, /* partial_inplace */ 0, /* src_mask */ 0, /* dst_mask */ FALSE), /* pcrel_offset */ HOWTO (R_MCORE_RELATIVE, /* type */ 0, /* rightshift */ 2, /* size (0 = byte, 1 = short, 2 = long) */ 32, /* bitsize */ FALSE, /* pc_relative */ 0, /* bitpos */ complain_overflow_signed, /* complain_on_overflow */ NULL, /* special_function */ "R_MCORE_RELATIVE", /* name */ TRUE, /* partial_inplace */ 0xffffffff, /* src_mask */ 0xffffffff, /* dst_mask */ FALSE) /* pcrel_offset */ }; #ifndef NUM_ELEM #define NUM_ELEM(a) (sizeof (a) / sizeof (a)[0]) #endif /* Initialize the mcore_elf_howto_table, so that linear accesses can be done. */ static void mcore_elf_howto_init (void) { unsigned int i; for (i = NUM_ELEM (mcore_elf_howto_raw); i--;) { unsigned int type; type = mcore_elf_howto_raw[i].type; BFD_ASSERT (type < NUM_ELEM (mcore_elf_howto_table)); mcore_elf_howto_table [type] = & mcore_elf_howto_raw [i]; } } static reloc_howto_type * mcore_elf_reloc_type_lookup (bfd * abfd ATTRIBUTE_UNUSED, bfd_reloc_code_real_type code) { enum elf_mcore_reloc_type mcore_reloc = R_MCORE_NONE; switch (code) { case BFD_RELOC_NONE: mcore_reloc = R_MCORE_NONE; break; case BFD_RELOC_32: mcore_reloc = R_MCORE_ADDR32; break; case BFD_RELOC_MCORE_PCREL_IMM8BY4: mcore_reloc = R_MCORE_PCRELIMM8BY4; break; case BFD_RELOC_MCORE_PCREL_IMM11BY2: mcore_reloc = R_MCORE_PCRELIMM11BY2; break; case BFD_RELOC_MCORE_PCREL_IMM4BY2: mcore_reloc = R_MCORE_PCRELIMM4BY2; break; case BFD_RELOC_32_PCREL: mcore_reloc = R_MCORE_PCREL32; break; case BFD_RELOC_MCORE_PCREL_JSR_IMM11BY2: mcore_reloc = R_MCORE_PCRELJSR_IMM11BY2; break; case BFD_RELOC_VTABLE_INHERIT: mcore_reloc = R_MCORE_GNU_VTINHERIT; break; case BFD_RELOC_VTABLE_ENTRY: mcore_reloc = R_MCORE_GNU_VTENTRY; break; case BFD_RELOC_RVA: mcore_reloc = R_MCORE_RELATIVE; break; default: return NULL; } if (! mcore_elf_howto_table [R_MCORE_PCRELIMM8BY4]) /* Initialize howto table if needed. */ mcore_elf_howto_init (); return mcore_elf_howto_table [(int) mcore_reloc]; }; static reloc_howto_type * mcore_elf_reloc_name_lookup (bfd *abfd ATTRIBUTE_UNUSED, const char *r_name) { unsigned int i; for (i = 0; i < sizeof (mcore_elf_howto_raw) / sizeof (mcore_elf_howto_raw[0]); i++) if (mcore_elf_howto_raw[i].name != NULL && strcasecmp (mcore_elf_howto_raw[i].name, r_name) == 0) return &mcore_elf_howto_raw[i]; return NULL; } /* Set the howto pointer for a RCE ELF reloc. */ static void mcore_elf_info_to_howto (bfd * abfd ATTRIBUTE_UNUSED, arelent * cache_ptr, Elf_Internal_Rela * dst) { unsigned int r_type; if (! mcore_elf_howto_table [R_MCORE_PCRELIMM8BY4]) /* Initialize howto table if needed. */ mcore_elf_howto_init (); r_type = ELF32_R_TYPE (dst->r_info); if (r_type >= R_MCORE_max) { (*_bfd_error_handler) (_("%B: unrecognised MCore reloc number: %d"), abfd, r_type); bfd_set_error (bfd_error_bad_value); r_type = R_MCORE_NONE; } cache_ptr->howto = mcore_elf_howto_table [r_type]; } /* The RELOCATE_SECTION function is called by the ELF backend linker to handle the relocations for a section. The relocs are always passed as Rela structures; if the section actually uses Rel structures, the r_addend field will always be zero. This function is responsible for adjust the section contents as necessary, and (if using Rela relocs and generating a relocatable output file) adjusting the reloc addend as necessary. This function does not have to worry about setting the reloc address or the reloc symbol index. LOCAL_SYMS is a pointer to the swapped in local symbols. LOCAL_SECTIONS is an array giving the section in the input file corresponding to the st_shndx field of each local symbol. The global hash table entry for the global symbols can be found via elf_sym_hashes (input_bfd). When generating relocatable output, this function must handle STB_LOCAL/STT_SECTION symbols specially. The output symbol is going to be the section symbol corresponding to the output section, which means that the addend must be adjusted accordingly. */ static bfd_boolean mcore_elf_relocate_section (bfd * output_bfd, struct bfd_link_info * info, bfd * input_bfd, asection * input_section, bfd_byte * contents, Elf_Internal_Rela * relocs, Elf_Internal_Sym * local_syms, asection ** local_sections) { Elf_Internal_Shdr * symtab_hdr = & elf_tdata (input_bfd)->symtab_hdr; struct elf_link_hash_entry ** sym_hashes = elf_sym_hashes (input_bfd); Elf_Internal_Rela * rel = relocs; Elf_Internal_Rela * relend = relocs + input_section->reloc_count; bfd_boolean ret = TRUE; #ifdef DEBUG _bfd_error_handler ("mcore_elf_relocate_section called for %B section %A, %ld relocations%s", input_bfd, input_section, (long) input_section->reloc_count, (bfd_link_relocatable (info)) ? " (relocatable)" : ""); #endif if (! mcore_elf_howto_table [R_MCORE_PCRELIMM8BY4]) /* Initialize howto table if needed */ mcore_elf_howto_init (); for (; rel < relend; rel++) { enum elf_mcore_reloc_type r_type = (enum elf_mcore_reloc_type) ELF32_R_TYPE (rel->r_info); bfd_vma offset = rel->r_offset; bfd_vma addend = rel->r_addend; bfd_reloc_status_type r = bfd_reloc_other; asection * sec = NULL; reloc_howto_type * howto; bfd_vma relocation; Elf_Internal_Sym * sym = NULL; unsigned long r_symndx; struct elf_link_hash_entry * h = NULL; unsigned short oldinst = 0; /* Unknown relocation handling. */ if ((unsigned) r_type >= (unsigned) R_MCORE_max || ! mcore_elf_howto_table [(int)r_type]) { _bfd_error_handler (_("%B: Unknown relocation type %d\n"), input_bfd, (int) r_type); bfd_set_error (bfd_error_bad_value); ret = FALSE; continue; } howto = mcore_elf_howto_table [(int) r_type]; r_symndx = ELF32_R_SYM (rel->r_info); /* Complain about known relocation that are not yet supported. */ if (howto->special_function == mcore_elf_unsupported_reloc) { _bfd_error_handler (_("%B: Relocation %s (%d) is not currently supported.\n"), input_bfd, howto->name, (int)r_type); bfd_set_error (bfd_error_bad_value); ret = FALSE; continue; } if (r_symndx < symtab_hdr->sh_info) { sym = local_syms + r_symndx; sec = local_sections [r_symndx]; relocation = _bfd_elf_rela_local_sym (output_bfd, sym, &sec, rel); addend = rel->r_addend; } else { bfd_boolean unresolved_reloc, warned, ignored; RELOC_FOR_GLOBAL_SYMBOL (info, input_bfd, input_section, rel, r_symndx, symtab_hdr, sym_hashes, h, sec, relocation, unresolved_reloc, warned, ignored); } if (sec != NULL && discarded_section (sec)) RELOC_AGAINST_DISCARDED_SECTION (info, input_bfd, input_section, rel, 1, relend, howto, 0, contents); if (bfd_link_relocatable (info)) continue; switch (r_type) { default: break; case R_MCORE_PCRELJSR_IMM11BY2: oldinst = bfd_get_16 (input_bfd, contents + offset); #define MCORE_INST_BSR 0xF800 bfd_put_16 (input_bfd, (bfd_vma) MCORE_INST_BSR, contents + offset); break; } #ifdef DEBUG fprintf (stderr, "\ttype = %s (%d), symbol index = %ld, offset = %ld, addend = %ld\n", howto->name, r_type, r_symndx, (long) offset, (long) addend); #endif r = _bfd_final_link_relocate (howto, input_bfd, input_section, contents, offset, relocation, addend); if (r != bfd_reloc_ok && r_type == R_MCORE_PCRELJSR_IMM11BY2) { /* Wasn't ok, back it out and give up. */ bfd_put_16 (input_bfd, (bfd_vma) oldinst, contents + offset); r = bfd_reloc_ok; } if (r != bfd_reloc_ok) { ret = FALSE; switch (r) { default: break; case bfd_reloc_overflow: { const char * name; if (h != NULL) name = NULL; else { name = bfd_elf_string_from_elf_section (input_bfd, symtab_hdr->sh_link, sym->st_name); if (name == NULL) break; if (* name == '\0') name = bfd_section_name (input_bfd, sec); } (*info->callbacks->reloc_overflow) (info, (h ? &h->root : NULL), name, howto->name, (bfd_vma) 0, input_bfd, input_section, offset); } break; } } } #ifdef DEBUG fprintf (stderr, "\n"); #endif return ret; } /* Return the section that should be marked against GC for a given relocation. */ static asection * mcore_elf_gc_mark_hook (asection *sec, struct bfd_link_info *info, Elf_Internal_Rela *rel, struct elf_link_hash_entry *h, Elf_Internal_Sym *sym) { if (h != NULL) switch (ELF32_R_TYPE (rel->r_info)) { case R_MCORE_GNU_VTINHERIT: case R_MCORE_GNU_VTENTRY: return NULL; } return _bfd_elf_gc_mark_hook (sec, info, rel, h, sym); } /* Update the got entry reference counts for the section being removed. */ static bfd_boolean mcore_elf_gc_sweep_hook (bfd * abfd ATTRIBUTE_UNUSED, struct bfd_link_info * info ATTRIBUTE_UNUSED, asection * sec ATTRIBUTE_UNUSED, const Elf_Internal_Rela * relocs ATTRIBUTE_UNUSED) { return TRUE; } /* Look through the relocs for a section during the first phase. Since we don't do .gots or .plts, we just need to consider the virtual table relocs for gc. */ static bfd_boolean mcore_elf_check_relocs (bfd * abfd, struct bfd_link_info * info, asection * sec, const Elf_Internal_Rela * relocs) { Elf_Internal_Shdr * symtab_hdr; struct elf_link_hash_entry ** sym_hashes; const Elf_Internal_Rela * rel; const Elf_Internal_Rela * rel_end; if (bfd_link_relocatable (info)) return TRUE; symtab_hdr = & elf_tdata (abfd)->symtab_hdr; sym_hashes = elf_sym_hashes (abfd); rel_end = relocs + sec->reloc_count; for (rel = relocs; rel < rel_end; rel++) { struct elf_link_hash_entry * h; unsigned long r_symndx; r_symndx = ELF32_R_SYM (rel->r_info); if (r_symndx < symtab_hdr->sh_info) h = NULL; else { h = sym_hashes [r_symndx - symtab_hdr->sh_info]; while (h->root.type == bfd_link_hash_indirect || h->root.type == bfd_link_hash_warning) h = (struct elf_link_hash_entry *) h->root.u.i.link; /* PR15323, ref flags aren't set for references in the same object. */ h->root.non_ir_ref = 1; } switch (ELF32_R_TYPE (rel->r_info)) { /* This relocation describes the C++ object vtable hierarchy. Reconstruct it for later use during GC. */ case R_MCORE_GNU_VTINHERIT: if (!bfd_elf_gc_record_vtinherit (abfd, sec, h, rel->r_offset)) return FALSE; break; /* This relocation describes which C++ vtable entries are actually used. Record for later use during GC. */ case R_MCORE_GNU_VTENTRY: BFD_ASSERT (h != NULL); if (h != NULL && !bfd_elf_gc_record_vtentry (abfd, sec, h, rel->r_addend)) return FALSE; break; } } return TRUE; } static const struct bfd_elf_special_section mcore_elf_special_sections[]= { { STRING_COMMA_LEN (".ctors"), -2, SHT_PROGBITS, SHF_ALLOC + SHF_WRITE }, { STRING_COMMA_LEN (".dtors"), -2, SHT_PROGBITS, SHF_ALLOC + SHF_WRITE }, { NULL, 0, 0, 0, 0 } }; #define TARGET_BIG_SYM mcore_elf32_be_vec #define TARGET_BIG_NAME "elf32-mcore-big" #define TARGET_LITTLE_SYM mcore_elf32_le_vec #define TARGET_LITTLE_NAME "elf32-mcore-little" #define ELF_ARCH bfd_arch_mcore #define ELF_MACHINE_CODE EM_MCORE #define ELF_MAXPAGESIZE 0x1000 /* 4k, if we ever have 'em */ #define elf_info_to_howto mcore_elf_info_to_howto #define elf_info_to_howto_rel NULL #define bfd_elf32_bfd_merge_private_bfd_data mcore_elf_merge_private_bfd_data #define bfd_elf32_bfd_set_private_flags mcore_elf_set_private_flags #define bfd_elf32_bfd_reloc_type_lookup mcore_elf_reloc_type_lookup #define bfd_elf32_bfd_reloc_name_lookup mcore_elf_reloc_name_lookup #define elf_backend_relocate_section mcore_elf_relocate_section #define elf_backend_gc_mark_hook mcore_elf_gc_mark_hook #define elf_backend_gc_sweep_hook mcore_elf_gc_sweep_hook #define elf_backend_check_relocs mcore_elf_check_relocs #define elf_backend_special_sections mcore_elf_special_sections #define elf_backend_can_gc_sections 1 #define elf_backend_rela_normal 1 #include "elf32-target.h"