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/* 32-bit ELF support for ARM Copyright 1998, 1999, 2000 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 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ typedef unsigned long int insn32; typedef unsigned short int insn16; static boolean elf32_arm_set_private_flags PARAMS ((bfd *, flagword)); static boolean elf32_arm_copy_private_bfd_data PARAMS ((bfd *, bfd *)); static boolean elf32_arm_merge_private_bfd_data PARAMS ((bfd *, bfd *)); static boolean elf32_arm_print_private_bfd_data PARAMS ((bfd *, PTR)); static int elf32_arm_get_symbol_type PARAMS (( Elf_Internal_Sym *, int)); static struct bfd_link_hash_table *elf32_arm_link_hash_table_create PARAMS ((bfd *)); static bfd_reloc_status_type elf32_arm_final_link_relocate PARAMS ((reloc_howto_type *, bfd *, bfd *, asection *, bfd_byte *, Elf_Internal_Rela *, bfd_vma, struct bfd_link_info *, asection *, const char *, unsigned char, struct elf_link_hash_entry *)); static insn32 insert_thumb_branch PARAMS ((insn32, int)); static struct elf_link_hash_entry *find_thumb_glue PARAMS ((struct bfd_link_info *, CONST char *, bfd *)); static struct elf_link_hash_entry *find_arm_glue PARAMS ((struct bfd_link_info *, CONST char *, bfd *)); static void record_arm_to_thumb_glue PARAMS ((struct bfd_link_info *, struct elf_link_hash_entry *)); static void record_thumb_to_arm_glue PARAMS ((struct bfd_link_info *, struct elf_link_hash_entry *)); static void elf32_arm_post_process_headers PARAMS ((bfd *, struct bfd_link_info *)); static int elf32_arm_to_thumb_stub PARAMS ((struct bfd_link_info *, const char *, bfd *, bfd *, asection *, bfd_byte *, asection *, bfd_vma, bfd_signed_vma, bfd_vma)); static int elf32_thumb_to_arm_stub PARAMS ((struct bfd_link_info *, const char *, bfd *, bfd *, asection *, bfd_byte *, asection *, bfd_vma, bfd_signed_vma, bfd_vma)); /* The linker script knows the section names for placement. The entry_names are used to do simple name mangling on the stubs. Given a function name, and its type, the stub can be found. The name can be changed. The only requirement is the %s be present. */ #define INTERWORK_FLAG( abfd ) (elf_elfheader (abfd)->e_flags & EF_INTERWORK) #define THUMB2ARM_GLUE_SECTION_NAME ".glue_7t" #define THUMB2ARM_GLUE_ENTRY_NAME "__%s_from_thumb" #define ARM2THUMB_GLUE_SECTION_NAME ".glue_7" #define ARM2THUMB_GLUE_ENTRY_NAME "__%s_from_arm" /* The name of the dynamic interpreter. This is put in the .interp section. */ #define ELF_DYNAMIC_INTERPRETER "/usr/lib/ld.so.1" /* The size in bytes of an entry in the procedure linkage table. */ #define PLT_ENTRY_SIZE 16 /* The first entry in a procedure linkage table looks like this. It is set up so that any shared library function that is called before the relocation has been set up calls the dynamic linker first */ static const bfd_byte elf32_arm_plt0_entry [PLT_ENTRY_SIZE] = { 0x04, 0xe0, 0x2d, 0xe5, /* str lr, [sp, #-4]! */ 0x10, 0xe0, 0x9f, 0xe5, /* ldr lr, [pc, #16] */ 0x0e, 0xe0, 0x8f, 0xe0, /* adr lr, pc, lr */ 0x08, 0xf0, 0xbe, 0xe5 /* ldr pc, [lr, #8]! */ }; /* Subsequent entries in a procedure linkage table look like this. */ static const bfd_byte elf32_arm_plt_entry [PLT_ENTRY_SIZE] = { 0x04, 0xc0, 0x9f, 0xe5, /* ldr ip, [pc, #4] */ 0x0c, 0xc0, 0x8f, 0xe0, /* add ip, pc, ip */ 0x00, 0xf0, 0x9c, 0xe5, /* ldr pc, [ip] */ 0x00, 0x00, 0x00, 0x00 /* offset to symbol in got */ }; /* The ARM linker needs to keep track of the number of relocs that it decides to copy in check_relocs for each symbol. This is so that it can discard PC relative relocs if it doesn't need them when linking with -Bsymbolic. We store the information in a field extending the regular ELF linker hash table. */ /* This structure keeps track of the number of PC relative relocs we have copied for a given symbol. */ struct elf32_arm_pcrel_relocs_copied { /* Next section. */ struct elf32_arm_pcrel_relocs_copied * next; /* A section in dynobj. */ asection * section; /* Number of relocs copied in this section. */ bfd_size_type count; }; /* Arm ELF linker hash entry. */ struct elf32_arm_link_hash_entry { struct elf_link_hash_entry root; /* Number of PC relative relocs copied for this symbol. */ struct elf32_arm_pcrel_relocs_copied * pcrel_relocs_copied; }; /* Declare this now that the above structures are defined. */ static boolean elf32_arm_discard_copies PARAMS ((struct elf32_arm_link_hash_entry *, PTR)); /* Traverse an arm ELF linker hash table. */ #define elf32_arm_link_hash_traverse(table, func, info) \ (elf_link_hash_traverse \ (&(table)->root, \ (boolean (*) PARAMS ((struct elf_link_hash_entry *, PTR))) (func), \ (info))) /* Get the ARM elf linker hash table from a link_info structure. */ #define elf32_arm_hash_table(info) \ ((struct elf32_arm_link_hash_table *) ((info)->hash)) /* ARM ELF linker hash table */ struct elf32_arm_link_hash_table { /* The main hash table. */ struct elf_link_hash_table root; /* The size in bytes of the section containg the Thumb-to-ARM glue. */ long int thumb_glue_size; /* The size in bytes of the section containg the ARM-to-Thumb glue. */ long int arm_glue_size; /* An arbitary input BFD chosen to hold the glue sections. */ bfd * bfd_of_glue_owner; /* A boolean indicating whether knowledge of the ARM's pipeline length should be applied by the linker. */ int no_pipeline_knowledge; }; /* Create an entry in an ARM ELF linker hash table. */ static struct bfd_hash_entry * elf32_arm_link_hash_newfunc (entry, table, string) struct bfd_hash_entry * entry; struct bfd_hash_table * table; const char * string; { struct elf32_arm_link_hash_entry * ret = (struct elf32_arm_link_hash_entry *) entry; /* Allocate the structure if it has not already been allocated by a subclass. */ if (ret == (struct elf32_arm_link_hash_entry *) NULL) ret = ((struct elf32_arm_link_hash_entry *) bfd_hash_allocate (table, sizeof (struct elf32_arm_link_hash_entry))); if (ret == (struct elf32_arm_link_hash_entry *) NULL) return (struct bfd_hash_entry *) ret; /* Call the allocation method of the superclass. */ ret = ((struct elf32_arm_link_hash_entry *) _bfd_elf_link_hash_newfunc ((struct bfd_hash_entry *) ret, table, string)); if (ret != (struct elf32_arm_link_hash_entry *) NULL) ret->pcrel_relocs_copied = NULL; return (struct bfd_hash_entry *) ret; } /* Create an ARM elf linker hash table */ static struct bfd_link_hash_table * elf32_arm_link_hash_table_create (abfd) bfd *abfd; { struct elf32_arm_link_hash_table *ret; ret = ((struct elf32_arm_link_hash_table *) bfd_alloc (abfd, sizeof (struct elf32_arm_link_hash_table))); if (ret == (struct elf32_arm_link_hash_table *) NULL) return NULL; if (!_bfd_elf_link_hash_table_init (&ret->root, abfd, elf32_arm_link_hash_newfunc)) { bfd_release (abfd, ret); return NULL; } ret->thumb_glue_size = 0; ret->arm_glue_size = 0; ret->bfd_of_glue_owner = NULL; ret->no_pipeline_knowledge = 0; return &ret->root.root; } static struct elf_link_hash_entry * find_thumb_glue (link_info, name, input_bfd) struct bfd_link_info *link_info; CONST char *name; bfd *input_bfd; { char *tmp_name; struct elf_link_hash_entry *hash; struct elf32_arm_link_hash_table *hash_table; /* We need a pointer to the armelf specific hash table. */ hash_table = elf32_arm_hash_table (link_info); tmp_name = ((char *) bfd_malloc (strlen (name) + strlen (THUMB2ARM_GLUE_ENTRY_NAME) + 1)); BFD_ASSERT (tmp_name); sprintf (tmp_name, THUMB2ARM_GLUE_ENTRY_NAME, name); hash = elf_link_hash_lookup (&(hash_table)->root, tmp_name, false, false, true); if (hash == NULL) /* xgettext:c-format */ _bfd_error_handler (_ ("%s: unable to find THUMB glue '%s' for `%s'"), bfd_get_filename (input_bfd), tmp_name, name); free (tmp_name); return hash; } static struct elf_link_hash_entry * find_arm_glue (link_info, name, input_bfd) struct bfd_link_info *link_info; CONST char *name; bfd *input_bfd; { char *tmp_name; struct elf_link_hash_entry *myh; struct elf32_arm_link_hash_table *hash_table; /* We need a pointer to the elfarm specific hash table. */ hash_table = elf32_arm_hash_table (link_info); tmp_name = ((char *) bfd_malloc (strlen (name) + strlen (ARM2THUMB_GLUE_ENTRY_NAME) + 1)); BFD_ASSERT (tmp_name); sprintf (tmp_name, ARM2THUMB_GLUE_ENTRY_NAME, name); myh = elf_link_hash_lookup (&(hash_table)->root, tmp_name, false, false, true); if (myh == NULL) /* xgettext:c-format */ _bfd_error_handler (_ ("%s: unable to find ARM glue '%s' for `%s'"), bfd_get_filename (input_bfd), tmp_name, name); free (tmp_name); return myh; } /* ARM->Thumb glue: .arm __func_from_arm: ldr r12, __func_addr bx r12 __func_addr: .word func @ behave as if you saw a ARM_32 reloc */ #define ARM2THUMB_GLUE_SIZE 12 static const insn32 a2t1_ldr_insn = 0xe59fc000; static const insn32 a2t2_bx_r12_insn = 0xe12fff1c; static const insn32 a2t3_func_addr_insn = 0x00000001; /* Thumb->ARM: Thumb->(non-interworking aware) ARM .thumb .thumb .align 2 .align 2 __func_from_thumb: __func_from_thumb: bx pc push {r6, lr} nop ldr r6, __func_addr .arm mov lr, pc __func_change_to_arm: bx r6 b func .arm __func_back_to_thumb: ldmia r13! {r6, lr} bx lr __func_addr: .word func */ #define THUMB2ARM_GLUE_SIZE 8 static const insn16 t2a1_bx_pc_insn = 0x4778; static const insn16 t2a2_noop_insn = 0x46c0; static const insn32 t2a3_b_insn = 0xea000000; static const insn16 t2a1_push_insn = 0xb540; static const insn16 t2a2_ldr_insn = 0x4e03; static const insn16 t2a3_mov_insn = 0x46fe; static const insn16 t2a4_bx_insn = 0x4730; static const insn32 t2a5_pop_insn = 0xe8bd4040; static const insn32 t2a6_bx_insn = 0xe12fff1e; boolean bfd_elf32_arm_allocate_interworking_sections (info) struct bfd_link_info * info; { asection * s; bfd_byte * foo; struct elf32_arm_link_hash_table * globals; globals = elf32_arm_hash_table (info); BFD_ASSERT (globals != NULL); if (globals->arm_glue_size != 0) { BFD_ASSERT (globals->bfd_of_glue_owner != NULL); s = bfd_get_section_by_name (globals->bfd_of_glue_owner, ARM2THUMB_GLUE_SECTION_NAME); BFD_ASSERT (s != NULL); foo = (bfd_byte *) bfd_alloc (globals->bfd_of_glue_owner, globals->arm_glue_size); s->_raw_size = s->_cooked_size = globals->arm_glue_size; s->contents = foo; } if (globals->thumb_glue_size != 0) { BFD_ASSERT (globals->bfd_of_glue_owner != NULL); s = bfd_get_section_by_name (globals->bfd_of_glue_owner, THUMB2ARM_GLUE_SECTION_NAME); BFD_ASSERT (s != NULL); foo = (bfd_byte *) bfd_alloc (globals->bfd_of_glue_owner, globals->thumb_glue_size); s->_raw_size = s->_cooked_size = globals->thumb_glue_size; s->contents = foo; } return true; } static void record_arm_to_thumb_glue (link_info, h) struct bfd_link_info * link_info; struct elf_link_hash_entry * h; { const char * name = h->root.root.string; register asection * s; char * tmp_name; struct elf_link_hash_entry * myh; struct elf32_arm_link_hash_table * globals; globals = elf32_arm_hash_table (link_info); BFD_ASSERT (globals != NULL); BFD_ASSERT (globals->bfd_of_glue_owner != NULL); s = bfd_get_section_by_name (globals->bfd_of_glue_owner, ARM2THUMB_GLUE_SECTION_NAME); BFD_ASSERT (s != NULL); tmp_name = ((char *) bfd_malloc (strlen (name) + strlen (ARM2THUMB_GLUE_ENTRY_NAME) + 1)); BFD_ASSERT (tmp_name); sprintf (tmp_name, ARM2THUMB_GLUE_ENTRY_NAME, name); myh = elf_link_hash_lookup (&(globals)->root, tmp_name, false, false, true); if (myh != NULL) { free (tmp_name); return; /* we've already seen this guy */ } /* The only trick here is using hash_table->arm_glue_size as the value. Even though the section isn't allocated yet, this is where we will be putting it. */ _bfd_generic_link_add_one_symbol (link_info, globals->bfd_of_glue_owner, tmp_name, BSF_GLOBAL, s, globals->arm_glue_size + 1, NULL, true, false, (struct bfd_link_hash_entry **) &myh); free (tmp_name); globals->arm_glue_size += ARM2THUMB_GLUE_SIZE; return; } static void record_thumb_to_arm_glue (link_info, h) struct bfd_link_info *link_info; struct elf_link_hash_entry *h; { const char *name = h->root.root.string; register asection *s; char *tmp_name; struct elf_link_hash_entry *myh; struct elf32_arm_link_hash_table *hash_table; char bind; hash_table = elf32_arm_hash_table (link_info); BFD_ASSERT (hash_table != NULL); BFD_ASSERT (hash_table->bfd_of_glue_owner != NULL); s = bfd_get_section_by_name (hash_table->bfd_of_glue_owner, THUMB2ARM_GLUE_SECTION_NAME); BFD_ASSERT (s != NULL); tmp_name = (char *) bfd_malloc (strlen (name) + strlen (THUMB2ARM_GLUE_ENTRY_NAME) + 1); BFD_ASSERT (tmp_name); sprintf (tmp_name, THUMB2ARM_GLUE_ENTRY_NAME, name); myh = elf_link_hash_lookup (&(hash_table)->root, tmp_name, false, false, true); if (myh != NULL) { free (tmp_name); return; /* we've already seen this guy */ } _bfd_generic_link_add_one_symbol (link_info, hash_table->bfd_of_glue_owner, tmp_name, BSF_GLOBAL, s, hash_table->thumb_glue_size + 1, NULL, true, false, (struct bfd_link_hash_entry **) &myh); /* If we mark it 'thumb', the disassembler will do a better job. */ bind = ELF_ST_BIND (myh->type); myh->type = ELF_ST_INFO (bind, STT_ARM_TFUNC); free (tmp_name); /* Allocate another symbol to mark where we switch to arm mode. */ #define CHANGE_TO_ARM "__%s_change_to_arm" #define BACK_FROM_ARM "__%s_back_from_arm" tmp_name = (char *) bfd_malloc (strlen (name) + strlen (CHANGE_TO_ARM) + 1); BFD_ASSERT (tmp_name); sprintf (tmp_name, CHANGE_TO_ARM, name); myh = NULL; _bfd_generic_link_add_one_symbol (link_info, hash_table->bfd_of_glue_owner, tmp_name, BSF_LOCAL, s, hash_table->thumb_glue_size + 4, NULL, true, false, (struct bfd_link_hash_entry **) &myh); free (tmp_name); hash_table->thumb_glue_size += THUMB2ARM_GLUE_SIZE; return; } /* Select a BFD to be used to hold the sections used by the glue code. This function is called from the linker scripts in ld/emultempl/ {armelf/pe}.em */ boolean bfd_elf32_arm_get_bfd_for_interworking (abfd, info) bfd *abfd; struct bfd_link_info *info; { struct elf32_arm_link_hash_table *globals; flagword flags; asection *sec; /* If we are only performing a partial link do not bother getting a bfd to hold the glue. */ if (info->relocateable) return true; globals = elf32_arm_hash_table (info); BFD_ASSERT (globals != NULL); if (globals->bfd_of_glue_owner != NULL) return true; sec = bfd_get_section_by_name (abfd, ARM2THUMB_GLUE_SECTION_NAME); if (sec == NULL) { /* Note: we do not include the flag SEC_LINKER_CREATED, as this will prevent elf_link_input_bfd() from processing the contents of this section. */ flags = SEC_ALLOC | SEC_LOAD | SEC_HAS_CONTENTS | SEC_IN_MEMORY | SEC_CODE | SEC_READONLY; sec = bfd_make_section (abfd, ARM2THUMB_GLUE_SECTION_NAME); if (sec == NULL || !bfd_set_section_flags (abfd, sec, flags) || !bfd_set_section_alignment (abfd, sec, 2)) return false; /* Set the gc mark to prevent the section from being removed by garbage collection, despite the fact that no relocs refer to this section. */ sec->gc_mark = 1; } sec = bfd_get_section_by_name (abfd, THUMB2ARM_GLUE_SECTION_NAME); if (sec == NULL) { flags = SEC_ALLOC | SEC_LOAD | SEC_HAS_CONTENTS | SEC_IN_MEMORY | SEC_CODE | SEC_READONLY; sec = bfd_make_section (abfd, THUMB2ARM_GLUE_SECTION_NAME); if (sec == NULL || !bfd_set_section_flags (abfd, sec, flags) || !bfd_set_section_alignment (abfd, sec, 2)) return false; sec->gc_mark = 1; } /* Save the bfd for later use. */ globals->bfd_of_glue_owner = abfd; return true; } boolean bfd_elf32_arm_process_before_allocation (abfd, link_info, no_pipeline_knowledge) bfd *abfd; struct bfd_link_info *link_info; int no_pipeline_knowledge; { Elf_Internal_Shdr *symtab_hdr; Elf_Internal_Rela *free_relocs = NULL; Elf_Internal_Rela *irel, *irelend; bfd_byte *contents = NULL; bfd_byte *free_contents = NULL; Elf32_External_Sym *extsyms = NULL; Elf32_External_Sym *free_extsyms = NULL; asection *sec; struct elf32_arm_link_hash_table *globals; /* If we are only performing a partial link do not bother to construct any glue. */ if (link_info->relocateable) return true; /* Here we have a bfd that is to be included on the link. We have a hook to do reloc rummaging, before section sizes are nailed down. */ globals = elf32_arm_hash_table (link_info); BFD_ASSERT (globals != NULL); BFD_ASSERT (globals->bfd_of_glue_owner != NULL); globals->no_pipeline_knowledge = no_pipeline_knowledge; /* Rummage around all the relocs and map the glue vectors. */ sec = abfd->sections; if (sec == NULL) return true; for (; sec != NULL; sec = sec->next) { if (sec->reloc_count == 0) continue; symtab_hdr = &elf_tdata (abfd)->symtab_hdr; /* Load the relocs. */ irel = (_bfd_elf32_link_read_relocs (abfd, sec, (PTR) NULL, (Elf_Internal_Rela *) NULL, false)); BFD_ASSERT (irel != 0); irelend = irel + sec->reloc_count; for (; irel < irelend; irel++) { long r_type; unsigned long r_index; struct elf_link_hash_entry *h; r_type = ELF32_R_TYPE (irel->r_info); r_index = ELF32_R_SYM (irel->r_info); /* These are the only relocation types we care about */ if ( r_type != R_ARM_PC24 && r_type != R_ARM_THM_PC22) continue; /* Get the section contents if we haven't done so already. */ if (contents == NULL) { /* Get cached copy if it exists. */ if (elf_section_data (sec)->this_hdr.contents != NULL) contents = elf_section_data (sec)->this_hdr.contents; else { /* Go get them off disk. */ contents = (bfd_byte *) bfd_malloc (sec->_raw_size); if (contents == NULL) goto error_return; free_contents = contents; if (!bfd_get_section_contents (abfd, sec, contents, (file_ptr) 0, sec->_raw_size)) goto error_return; } } /* Read this BFD's symbols if we haven't done so already. */ if (extsyms == NULL) { /* Get cached copy if it exists. */ if (symtab_hdr->contents != NULL) extsyms = (Elf32_External_Sym *) symtab_hdr->contents; else { /* Go get them off disk. */ extsyms = ((Elf32_External_Sym *) bfd_malloc (symtab_hdr->sh_size)); if (extsyms == NULL) goto error_return; free_extsyms = extsyms; if (bfd_seek (abfd, symtab_hdr->sh_offset, SEEK_SET) != 0 || (bfd_read (extsyms, 1, symtab_hdr->sh_size, abfd) != symtab_hdr->sh_size)) goto error_return; } } /* If the relocation is not against a symbol it cannot concern us. */ h = NULL; /* We don't care about local symbols */ if (r_index < symtab_hdr->sh_info) continue; /* This is an external symbol */ r_index -= symtab_hdr->sh_info; h = (struct elf_link_hash_entry *) elf_sym_hashes (abfd)[r_index]; /* If the relocation is against a static symbol it must be within the current section and so cannot be a cross ARM/Thumb relocation. */ if (h == NULL) continue; switch (r_type) { case R_ARM_PC24: /* This one is a call from arm code. We need to look up the target of the call. If it is a thumb target, we insert glue. */ if (ELF_ST_TYPE(h->type) == STT_ARM_TFUNC) record_arm_to_thumb_glue (link_info, h); break; case R_ARM_THM_PC22: /* This one is a call from thumb code. We look up the target of the call. If it is not a thumb target, we insert glue. */ if (ELF_ST_TYPE (h->type) != STT_ARM_TFUNC) record_thumb_to_arm_glue (link_info, h); break; default: break; } } } return true; error_return: if (free_relocs != NULL) free (free_relocs); if (free_contents != NULL) free (free_contents); if (free_extsyms != NULL) free (free_extsyms); return false; } /* The thumb form of a long branch is a bit finicky, because the offset encoding is split over two fields, each in it's own instruction. They can occur in any order. So given a thumb form of long branch, and an offset, insert the offset into the thumb branch and return finished instruction. It takes two thumb instructions to encode the target address. Each has 11 bits to invest. The upper 11 bits are stored in one (identifed by H-0.. see below), the lower 11 bits are stored in the other (identified by H-1). Combine together and shifted left by 1 (it's a half word address) and there you have it. Op: 1111 = F, H-0, upper address-0 = 000 Op: 1111 = F, H-1, lower address-0 = 800 They can be ordered either way, but the arm tools I've seen always put the lower one first. It probably doesn't matter. krk@cygnus.com XXX: Actually the order does matter. The second instruction (H-1) moves the computed address into the PC, so it must be the second one in the sequence. The problem, however is that whilst little endian code stores the instructions in HI then LOW order, big endian code does the reverse. nickc@cygnus.com. */ #define LOW_HI_ORDER 0xF800F000 #define HI_LOW_ORDER 0xF000F800 static insn32 insert_thumb_branch (br_insn, rel_off) insn32 br_insn; int rel_off; { unsigned int low_bits; unsigned int high_bits; BFD_ASSERT ((rel_off & 1) != 1); rel_off >>= 1; /* Half word aligned address. */ low_bits = rel_off & 0x000007FF; /* The bottom 11 bits. */ high_bits = (rel_off >> 11) & 0x000007FF; /* The top 11 bits. */ if ((br_insn & LOW_HI_ORDER) == LOW_HI_ORDER) br_insn = LOW_HI_ORDER | (low_bits << 16) | high_bits; else if ((br_insn & HI_LOW_ORDER) == HI_LOW_ORDER) br_insn = HI_LOW_ORDER | (high_bits << 16) | low_bits; else abort (); /* error - not a valid branch instruction form */ /* FIXME: abort is probably not the right call. krk@cygnus.com */ return br_insn; } /* Thumb code calling an ARM function */ static int elf32_thumb_to_arm_stub (info, name, input_bfd, output_bfd, input_section, hit_data, sym_sec, offset, addend, val) struct bfd_link_info * info; const char * name; bfd * input_bfd; bfd * output_bfd; asection * input_section; bfd_byte * hit_data; asection * sym_sec; bfd_vma offset; bfd_signed_vma addend; bfd_vma val; { asection * s = 0; long int my_offset; unsigned long int tmp; long int ret_offset; struct elf_link_hash_entry * myh; struct elf32_arm_link_hash_table * globals; myh = find_thumb_glue (info, name, input_bfd); if (myh == NULL) return false; globals = elf32_arm_hash_table (info); BFD_ASSERT (globals != NULL); BFD_ASSERT (globals->bfd_of_glue_owner != NULL); my_offset = myh->root.u.def.value; s = bfd_get_section_by_name (globals->bfd_of_glue_owner, THUMB2ARM_GLUE_SECTION_NAME); BFD_ASSERT (s != NULL); BFD_ASSERT (s->contents != NULL); BFD_ASSERT (s->output_section != NULL); if ((my_offset & 0x01) == 0x01) { if (sym_sec != NULL && sym_sec->owner != NULL && !INTERWORK_FLAG (sym_sec->owner)) { _bfd_error_handler (_ ("%s(%s): warning: interworking not enabled."), bfd_get_filename (sym_sec->owner), name); _bfd_error_handler (_ (" first occurrence: %s: thumb call to arm"), bfd_get_filename (input_bfd)); return false; } --my_offset; myh->root.u.def.value = my_offset; bfd_put_16 (output_bfd, t2a1_bx_pc_insn, s->contents + my_offset); bfd_put_16 (output_bfd, t2a2_noop_insn, s->contents + my_offset + 2); ret_offset = ((bfd_signed_vma) val) /* Address of destination of the stub */ - ((bfd_signed_vma) (s->output_offset /* Offset from the start of the current section to the start of the stubs. */ + my_offset /* Offset of the start of this stub from the start of the stubs. */ + s->output_section->vma) /* Address of the start of the current section. */ + 4 /* The branch instruction is 4 bytes into the stub. */ + 8); /* ARM branches work from the pc of the instruction + 8. */ bfd_put_32 (output_bfd, t2a3_b_insn | ((ret_offset >> 2) & 0x00FFFFFF), s->contents + my_offset + 4); } BFD_ASSERT (my_offset <= globals->thumb_glue_size); /* Now go back and fix up the original BL insn to point to here. */ ret_offset = s->output_offset + my_offset - (input_section->output_offset + offset + addend) - 8; tmp = bfd_get_32 (input_bfd, hit_data - input_section->vma); bfd_put_32 (output_bfd, insert_thumb_branch (tmp, ret_offset), hit_data - input_section->vma); return true; } /* Arm code calling a Thumb function */ static int elf32_arm_to_thumb_stub (info, name, input_bfd, output_bfd, input_section, hit_data, sym_sec, offset, addend, val) struct bfd_link_info * info; const char * name; bfd * input_bfd; bfd * output_bfd; asection * input_section; bfd_byte * hit_data; asection * sym_sec; bfd_vma offset; bfd_signed_vma addend; bfd_vma val; { unsigned long int tmp; long int my_offset; asection * s; long int ret_offset; struct elf_link_hash_entry * myh; struct elf32_arm_link_hash_table * globals; myh = find_arm_glue (info, name, input_bfd); if (myh == NULL) return false; globals = elf32_arm_hash_table (info); BFD_ASSERT (globals != NULL); BFD_ASSERT (globals->bfd_of_glue_owner != NULL); my_offset = myh->root.u.def.value; s = bfd_get_section_by_name (globals->bfd_of_glue_owner, ARM2THUMB_GLUE_SECTION_NAME); BFD_ASSERT (s != NULL); BFD_ASSERT (s->contents != NULL); BFD_ASSERT (s->output_section != NULL); if ((my_offset & 0x01) == 0x01) { if (sym_sec != NULL && sym_sec->owner != NULL && !INTERWORK_FLAG (sym_sec->owner)) { _bfd_error_handler (_ ("%s(%s): warning: interworking not enabled."), bfd_get_filename (sym_sec->owner), name); _bfd_error_handler (_ (" first occurrence: %s: arm call to thumb"), bfd_get_filename (input_bfd)); } --my_offset; myh->root.u.def.value = my_offset; bfd_put_32 (output_bfd, a2t1_ldr_insn, s->contents + my_offset); bfd_put_32 (output_bfd, a2t2_bx_r12_insn, s->contents + my_offset + 4); /* It's a thumb address. Add the low order bit. */ bfd_put_32 (output_bfd, val | a2t3_func_addr_insn, s->contents + my_offset + 8); } BFD_ASSERT (my_offset <= globals->arm_glue_size); tmp = bfd_get_32 (input_bfd, hit_data); tmp = tmp & 0xFF000000; /* Somehow these are both 4 too far, so subtract 8. */ ret_offset = s->output_offset + my_offset + s->output_section->vma - (input_section->output_offset + input_section->output_section->vma + offset + addend) - 8; tmp = tmp | ((ret_offset >> 2) & 0x00FFFFFF); bfd_put_32 (output_bfd, tmp, hit_data - input_section->vma); return true; } /* Perform a relocation as part of a final link. */ static bfd_reloc_status_type elf32_arm_final_link_relocate (howto, input_bfd, output_bfd, input_section, contents, rel, value, info, sym_sec, sym_name, sym_flags, h) reloc_howto_type * howto; bfd * input_bfd; bfd * output_bfd; asection * input_section; bfd_byte * contents; Elf_Internal_Rela * rel; bfd_vma value; struct bfd_link_info * info; asection * sym_sec; const char * sym_name; unsigned char sym_flags; struct elf_link_hash_entry * h; { unsigned long r_type = howto->type; unsigned long r_symndx; bfd_byte * hit_data = contents + rel->r_offset; bfd * dynobj = NULL; Elf_Internal_Shdr * symtab_hdr; struct elf_link_hash_entry ** sym_hashes; bfd_vma * local_got_offsets; asection * sgot = NULL; asection * splt = NULL; asection * sreloc = NULL; bfd_vma addend; bfd_signed_vma signed_addend; struct elf32_arm_link_hash_table * globals; globals = elf32_arm_hash_table (info); dynobj = elf_hash_table (info)->dynobj; if (dynobj) { sgot = bfd_get_section_by_name (dynobj, ".got"); splt = bfd_get_section_by_name (dynobj, ".plt"); } symtab_hdr = & elf_tdata (input_bfd)->symtab_hdr; sym_hashes = elf_sym_hashes (input_bfd); local_got_offsets = elf_local_got_offsets (input_bfd); r_symndx = ELF32_R_SYM (rel->r_info); #ifdef USE_REL addend = bfd_get_32 (input_bfd, hit_data) & howto->src_mask; if (addend & ((howto->src_mask + 1) >> 1)) { signed_addend = -1; signed_addend &= ~ howto->src_mask; signed_addend |= addend; } else signed_addend = addend; #else addend = signed_addend = rel->r_addend; #endif switch (r_type) { case R_ARM_NONE: return bfd_reloc_ok; case R_ARM_PC24: case R_ARM_ABS32: case R_ARM_REL32: #ifndef OLD_ARM_ABI case R_ARM_XPC25: #endif /* When generating a shared object, these relocations are copied into the output file to be resolved at run time. */ if (info->shared && (r_type != R_ARM_PC24 || (h != NULL && h->dynindx != -1 && (! info->symbolic || (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)))) { Elf_Internal_Rel outrel; boolean skip, relocate; if (sreloc == NULL) { const char * name; name = (bfd_elf_string_from_elf_section (input_bfd, elf_elfheader (input_bfd)->e_shstrndx, elf_section_data (input_section)->rel_hdr.sh_name)); if (name == NULL) return bfd_reloc_notsupported; BFD_ASSERT (strncmp (name, ".rel", 4) == 0 && strcmp (bfd_get_section_name (input_bfd, input_section), name + 4) == 0); sreloc = bfd_get_section_by_name (dynobj, name); BFD_ASSERT (sreloc != NULL); } skip = false; if (elf_section_data (input_section)->stab_info == NULL) outrel.r_offset = rel->r_offset; else { bfd_vma off; off = (_bfd_stab_section_offset (output_bfd, &elf_hash_table (info)->stab_info, input_section, & elf_section_data (input_section)->stab_info, rel->r_offset)); if (off == (bfd_vma) -1) skip = true; outrel.r_offset = off; } outrel.r_offset += (input_section->output_section->vma + input_section->output_offset); if (skip) { memset (&outrel, 0, sizeof outrel); relocate = false; } else if (r_type == R_ARM_PC24) { BFD_ASSERT (h != NULL && h->dynindx != -1); if ((input_section->flags & SEC_ALLOC) != 0) relocate = false; else relocate = true; outrel.r_info = ELF32_R_INFO (h->dynindx, R_ARM_PC24); } else { if (h == NULL || ((info->symbolic || h->dynindx == -1) && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0)) { relocate = true; outrel.r_info = ELF32_R_INFO (0, R_ARM_RELATIVE); } else { BFD_ASSERT (h->dynindx != -1); if ((input_section->flags & SEC_ALLOC) != 0) relocate = false; else relocate = true; outrel.r_info = ELF32_R_INFO (h->dynindx, R_ARM_ABS32); } } bfd_elf32_swap_reloc_out (output_bfd, &outrel, (((Elf32_External_Rel *) sreloc->contents) + sreloc->reloc_count)); ++sreloc->reloc_count; /* If this reloc is against an external symbol, we do not want to fiddle with the addend. Otherwise, we need to include the symbol value so that it becomes an addend for the dynamic reloc. */ if (! relocate) return bfd_reloc_ok; return _bfd_final_link_relocate (howto, input_bfd, input_section, contents, rel->r_offset, value, (bfd_vma) 0); } else switch (r_type) { #ifndef OLD_ARM_ABI case R_ARM_XPC25: /* Arm BLX instruction. */ #endif case R_ARM_PC24: /* Arm B/BL instruction */ #ifndef OLD_ARM_ABI if (r_type == R_ARM_XPC25) { /* Check for Arm calling Arm function. */ /* FIXME: Should we translate the instruction into a BL instruction instead ? */ if (sym_flags != STT_ARM_TFUNC) _bfd_error_handler (_("\ %s: Warning: Arm BLX instruction targets Arm function '%s'."), bfd_get_filename (input_bfd), h->root.root.string); } else #endif { /* Check for Arm calling Thumb function. */ if (sym_flags == STT_ARM_TFUNC) { elf32_arm_to_thumb_stub (info, sym_name, input_bfd, output_bfd, input_section, hit_data, sym_sec, rel->r_offset, signed_addend, value); return bfd_reloc_ok; } } if ( strcmp (bfd_get_target (input_bfd), "elf32-littlearm-oabi") == 0 || strcmp (bfd_get_target (input_bfd), "elf32-bigarm-oabi") == 0) { /* The old way of doing things. Trearing the addend as a byte sized field and adding in the pipeline offset. */ value -= (input_section->output_section->vma + input_section->output_offset); value -= rel->r_offset; value += addend; if (! globals->no_pipeline_knowledge) value -= 8; } else { /* The ARM ELF ABI says that this reloc is computed as: S - P + A where: S is the address of the symbol in the relocation. P is address of the instruction being relocated. A is the addend (extracted from the instruction) in bytes. S is held in 'value'. P is the base address of the section containing the instruction plus the offset of the reloc into that section, ie: (input_section->output_section->vma + input_section->output_offset + rel->r_offset). A is the addend, converted into bytes, ie: (signed_addend * 4) Note: None of these operations have knowledge of the pipeline size of the processor, thus it is up to the assembler to encode this information into the addend. */ value -= (input_section->output_section->vma + input_section->output_offset); value -= rel->r_offset; value += (signed_addend << howto->size); /* Previous versions of this code also used to add in the pipeline offset here. This is wrong because the linker is not supposed to know about such things, and one day it might change. In order to support old binaries that need the old behaviour however, so we attempt to detect which ABI was used to create the reloc. */ if (! globals->no_pipeline_knowledge) { Elf_Internal_Ehdr * i_ehdrp; /* Elf file header, internal form */ i_ehdrp = elf_elfheader (input_bfd); if (i_ehdrp->e_ident[EI_OSABI] == 0) value -= 8; } } /* It is not an error for an undefined weak reference to be out of range. Any program that branches to such a symbol is going to crash anyway, so there is no point worrying about getting the destination exactly right. */ if (! h || h->root.type != bfd_link_hash_undefweak) { /* Perform a signed range check. */ signed_addend = value; signed_addend >>= howto->rightshift; if (signed_addend > ((bfd_signed_vma)(howto->dst_mask >> 1)) || signed_addend < - ((bfd_signed_vma) ((howto->dst_mask + 1) >> 1))) return bfd_reloc_overflow; } value = (signed_addend & howto->dst_mask) | (bfd_get_32 (input_bfd, hit_data) & (~ howto->dst_mask)); break; case R_ARM_ABS32: value += addend; if (sym_flags == STT_ARM_TFUNC) value |= 1; break; case R_ARM_REL32: value -= (input_section->output_section->vma + input_section->output_offset); value += addend; break; } bfd_put_32 (input_bfd, value, hit_data); return bfd_reloc_ok; case R_ARM_ABS8: value += addend; if ((long) value > 0x7f || (long) value < -0x80) return bfd_reloc_overflow; bfd_put_8 (input_bfd, value, hit_data); return bfd_reloc_ok; case R_ARM_ABS16: value += addend; if ((long) value > 0x7fff || (long) value < -0x8000) return bfd_reloc_overflow; bfd_put_16 (input_bfd, value, hit_data); return bfd_reloc_ok; case R_ARM_ABS12: /* Support ldr and str instruction for the arm */ /* Also thumb b (unconditional branch). ??? Really? */ value += addend; if ((long) value > 0x7ff || (long) value < -0x800) return bfd_reloc_overflow; value |= (bfd_get_32 (input_bfd, hit_data) & 0xfffff000); bfd_put_32 (input_bfd, value, hit_data); return bfd_reloc_ok; case R_ARM_THM_ABS5: /* Support ldr and str instructions for the thumb. */ #ifdef USE_REL /* Need to refetch addend. */ addend = bfd_get_16 (input_bfd, hit_data) & howto->src_mask; /* ??? Need to determine shift amount from operand size. */ addend >>= howto->rightshift; #endif value += addend; /* ??? Isn't value unsigned? */ if ((long) value > 0x1f || (long) value < -0x10) return bfd_reloc_overflow; /* ??? Value needs to be properly shifted into place first. */ value |= bfd_get_16 (input_bfd, hit_data) & 0xf83f; bfd_put_16 (input_bfd, value, hit_data); return bfd_reloc_ok; #ifndef OLD_ARM_ABI case R_ARM_THM_XPC22: #endif case R_ARM_THM_PC22: /* Thumb BL (branch long instruction). */ { bfd_vma relocation; boolean overflow = false; bfd_vma upper_insn = bfd_get_16 (input_bfd, hit_data); bfd_vma lower_insn = bfd_get_16 (input_bfd, hit_data + 2); bfd_signed_vma reloc_signed_max = (1 << (howto->bitsize - 1)) - 1; bfd_signed_vma reloc_signed_min = ~ reloc_signed_max; bfd_vma check; bfd_signed_vma signed_check; #ifdef USE_REL /* Need to refetch the addend and squish the two 11 bit pieces together. */ { bfd_vma upper = upper_insn & 0x7ff; bfd_vma lower = lower_insn & 0x7ff; upper = (upper ^ 0x400) - 0x400; /* sign extend */ addend = (upper << 12) | (lower << 1); signed_addend = addend; } #endif #ifndef OLD_ARM_ABI if (r_type == R_ARM_THM_XPC22) { /* Check for Thumb to Thumb call. */ /* FIXME: Should we translate the instruction into a BL instruction instead ? */ if (sym_flags == STT_ARM_TFUNC) _bfd_error_handler (_("\ %s: Warning: Thumb BLX instruction targets thumb function '%s'."), bfd_get_filename (input_bfd), h->root.root.string); } else #endif { /* If it is not a call to Thumb, assume call to Arm. If it is a call relative to a section name, then it is not a function call at all, but rather a long jump. */ if (sym_flags != STT_ARM_TFUNC && sym_flags != STT_SECTION) { if (elf32_thumb_to_arm_stub (info, sym_name, input_bfd, output_bfd, input_section, hit_data, sym_sec, rel->r_offset, signed_addend, value)) return bfd_reloc_ok; else return bfd_reloc_dangerous; } } relocation = value + signed_addend; relocation -= (input_section->output_section->vma + input_section->output_offset + rel->r_offset); if (! globals->no_pipeline_knowledge) { Elf_Internal_Ehdr * i_ehdrp; /* Elf file header, internal form */ i_ehdrp = elf_elfheader (input_bfd); /* Previous versions of this code also used to add in the pipline offset here. This is wrong because the linker is not supposed to know about such things, and one day it might change. In order to support old binaries that need the old behaviour however, so we attempt to detect which ABI was used to create the reloc. */ if ( strcmp (bfd_get_target (input_bfd), "elf32-littlearm-oabi") == 0 || strcmp (bfd_get_target (input_bfd), "elf32-bigarm-oabi") == 0 || i_ehdrp->e_ident[EI_OSABI] == 0) relocation += 4; } check = relocation >> howto->rightshift; /* If this is a signed value, the rightshift just dropped leading 1 bits (assuming twos complement). */ if ((bfd_signed_vma) relocation >= 0) signed_check = check; else signed_check = check | ~((bfd_vma) -1 >> howto->rightshift); /* Assumes two's complement. */ if (signed_check > reloc_signed_max || signed_check < reloc_signed_min) overflow = true; /* Put RELOCATION back into the insn. */ upper_insn = (upper_insn & ~(bfd_vma) 0x7ff) | ((relocation >> 12) & 0x7ff); lower_insn = (lower_insn & ~(bfd_vma) 0x7ff) | ((relocation >> 1) & 0x7ff); /* Put the relocated value back in the object file: */ bfd_put_16 (input_bfd, upper_insn, hit_data); bfd_put_16 (input_bfd, lower_insn, hit_data + 2); return (overflow ? bfd_reloc_overflow : bfd_reloc_ok); } break; case R_ARM_GNU_VTINHERIT: case R_ARM_GNU_VTENTRY: return bfd_reloc_ok; case R_ARM_COPY: return bfd_reloc_notsupported; case R_ARM_GLOB_DAT: return bfd_reloc_notsupported; case R_ARM_JUMP_SLOT: return bfd_reloc_notsupported; case R_ARM_RELATIVE: return bfd_reloc_notsupported; case R_ARM_GOTOFF: /* Relocation is relative to the start of the global offset table. */ BFD_ASSERT (sgot != NULL); if (sgot == NULL) return bfd_reloc_notsupported; /* Note that sgot->output_offset is not involved in this calculation. We always want the start of .got. If we define _GLOBAL_OFFSET_TABLE in a different way, as is permitted by the ABI, we might have to change this calculation. */ value -= sgot->output_section->vma; return _bfd_final_link_relocate (howto, input_bfd, input_section, contents, rel->r_offset, value, (bfd_vma) 0); case R_ARM_GOTPC: /* Use global offset table as symbol value. */ BFD_ASSERT (sgot != NULL); if (sgot == NULL) return bfd_reloc_notsupported; value = sgot->output_section->vma; return _bfd_final_link_relocate (howto, input_bfd, input_section, contents, rel->r_offset, value, (bfd_vma) 0); case R_ARM_GOT32: /* Relocation is to the entry for this symbol in the global offset table. */ if (sgot == NULL) return bfd_reloc_notsupported; if (h != NULL) { bfd_vma off; off = h->got.offset; BFD_ASSERT (off != (bfd_vma) -1); if (!elf_hash_table (info)->dynamic_sections_created || (info->shared && (info->symbolic || h->dynindx == -1) && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR))) { /* This is actually a static link, or it is a -Bsymbolic link and the symbol is defined locally. We must initialize this entry in the global offset table. Since the offset must always be a multiple of 4, we use the least significant bit to record whether we have initialized it already. When doing a dynamic link, we create a .rel.got relocation entry to initialize the value. This is done in the finish_dynamic_symbol routine. */ if ((off & 1) != 0) off &= ~1; else { bfd_put_32 (output_bfd, value, sgot->contents + off); h->got.offset |= 1; } } value = sgot->output_offset + off; } else { bfd_vma off; BFD_ASSERT (local_got_offsets != NULL && local_got_offsets[r_symndx] != (bfd_vma) -1); off = local_got_offsets[r_symndx]; /* The offset must always be a multiple of 4. We use the least significant bit to record whether we have already generated the necessary reloc. */ if ((off & 1) != 0) off &= ~1; else { bfd_put_32 (output_bfd, value, sgot->contents + off); if (info->shared) { asection * srelgot; Elf_Internal_Rel outrel; srelgot = bfd_get_section_by_name (dynobj, ".rel.got"); BFD_ASSERT (srelgot != NULL); outrel.r_offset = (sgot->output_section->vma + sgot->output_offset + off); outrel.r_info = ELF32_R_INFO (0, R_ARM_RELATIVE); bfd_elf32_swap_reloc_out (output_bfd, &outrel, (((Elf32_External_Rel *) srelgot->contents) + srelgot->reloc_count)); ++srelgot->reloc_count; } local_got_offsets[r_symndx] |= 1; } value = sgot->output_offset + off; } return _bfd_final_link_relocate (howto, input_bfd, input_section, contents, rel->r_offset, value, (bfd_vma) 0); case R_ARM_PLT32: /* Relocation is to the entry for this symbol in the procedure linkage table. */ /* Resolve a PLT32 reloc against a local symbol directly, without using the procedure linkage table. */ if (h == NULL) return _bfd_final_link_relocate (howto, input_bfd, input_section, contents, rel->r_offset, value, (bfd_vma) 0); if (h->plt.offset == (bfd_vma) -1) /* We didn't make a PLT entry for this symbol. This happens when statically linking PIC code, or when using -Bsymbolic. */ return _bfd_final_link_relocate (howto, input_bfd, input_section, contents, rel->r_offset, value, (bfd_vma) 0); BFD_ASSERT(splt != NULL); if (splt == NULL) return bfd_reloc_notsupported; value = (splt->output_section->vma + splt->output_offset + h->plt.offset); return _bfd_final_link_relocate (howto, input_bfd, input_section, contents, rel->r_offset, value, (bfd_vma) 0); case R_ARM_SBREL32: return bfd_reloc_notsupported; case R_ARM_AMP_VCALL9: return bfd_reloc_notsupported; case R_ARM_RSBREL32: return bfd_reloc_notsupported; case R_ARM_THM_RPC22: return bfd_reloc_notsupported; case R_ARM_RREL32: return bfd_reloc_notsupported; case R_ARM_RABS32: return bfd_reloc_notsupported; case R_ARM_RPC24: return bfd_reloc_notsupported; case R_ARM_RBASE: return bfd_reloc_notsupported; default: return bfd_reloc_notsupported; } } #ifdef USE_REL /* Add INCREMENT to the reloc (of type HOWTO) at ADDRESS. */ static void arm_add_to_rel (abfd, address, howto, increment) bfd * abfd; bfd_byte * address; reloc_howto_type * howto; bfd_signed_vma increment; { bfd_vma contents; bfd_signed_vma addend; contents = bfd_get_32 (abfd, address); /* Get the (signed) value from the instruction. */ addend = contents & howto->src_mask; if (addend & ((howto->src_mask + 1) >> 1)) { bfd_signed_vma mask; mask = -1; mask &= ~ howto->src_mask; addend |= mask; } /* Add in the increment, (which is a byte value). */ switch (howto->type) { case R_ARM_THM_PC22: default: addend += increment; break; case R_ARM_PC24: addend <<= howto->size; addend += increment; /* Should we check for overflow here ? */ /* Drop any undesired bits. */ addend >>= howto->rightshift; break; } contents = (contents & ~ howto->dst_mask) | (addend & howto->dst_mask); bfd_put_32 (abfd, contents, address); } #endif /* USE_REL */ /* Relocate an ARM ELF section. */ static boolean elf32_arm_relocate_section (output_bfd, info, input_bfd, input_section, contents, relocs, local_syms, local_sections) 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; struct elf_link_hash_entry ** sym_hashes; Elf_Internal_Rela * rel; Elf_Internal_Rela * relend; const char * name; symtab_hdr = & elf_tdata (input_bfd)->symtab_hdr; sym_hashes = elf_sym_hashes (input_bfd); rel = relocs; relend = relocs + input_section->reloc_count; for (; rel < relend; rel++) { int r_type; reloc_howto_type * howto; unsigned long r_symndx; Elf_Internal_Sym * sym; asection * sec; struct elf_link_hash_entry * h; bfd_vma relocation; bfd_reloc_status_type r; arelent bfd_reloc; r_symndx = ELF32_R_SYM (rel->r_info); r_type = ELF32_R_TYPE (rel->r_info); if ( r_type == R_ARM_GNU_VTENTRY || r_type == R_ARM_GNU_VTINHERIT) continue; elf32_arm_info_to_howto (input_bfd, & bfd_reloc, rel); howto = bfd_reloc.howto; if (info->relocateable) { /* This is a relocateable link. We don't have to change anything, unless the reloc is against a section symbol, in which case we have to adjust according to where the section symbol winds up in the output section. */ if (r_symndx < symtab_hdr->sh_info) { sym = local_syms + r_symndx; if (ELF_ST_TYPE (sym->st_info) == STT_SECTION) { sec = local_sections[r_symndx]; #ifdef USE_REL arm_add_to_rel (input_bfd, contents + rel->r_offset, howto, sec->output_offset + sym->st_value); #else rel->r_addend += (sec->output_offset + sym->st_value) >> howto->rightshift; #endif } } continue; } /* This is a final link. */ h = NULL; sym = NULL; sec = NULL; if (r_symndx < symtab_hdr->sh_info) { sym = local_syms + r_symndx; sec = local_sections[r_symndx]; relocation = (sec->output_section->vma + sec->output_offset + sym->st_value); } 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; if (h->root.type == bfd_link_hash_defined || h->root.type == bfd_link_hash_defweak) { int relocation_needed = 1; sec = h->root.u.def.section; /* In these cases, we don't need the relocation value. We check specially because in some obscure cases sec->output_section will be NULL. */ switch (r_type) { case R_ARM_PC24: case R_ARM_ABS32: if (info->shared && ( (!info->symbolic && h->dynindx != -1) || (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0 ) && ((input_section->flags & SEC_ALLOC) != 0) ) relocation_needed = 0; break; case R_ARM_GOTPC: relocation_needed = 0; break; case R_ARM_GOT32: if (elf_hash_table(info)->dynamic_sections_created && (!info->shared || (!info->symbolic && h->dynindx != -1) || (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0 ) ) relocation_needed = 0; break; case R_ARM_PLT32: if (h->plt.offset != (bfd_vma)-1) relocation_needed = 0; break; default: if (sec->output_section == NULL) { (*_bfd_error_handler) (_("%s: warning: unresolvable relocation against symbol `%s' from %s section"), bfd_get_filename (input_bfd), h->root.root.string, bfd_get_section_name (input_bfd, input_section)); relocation_needed = 0; } } if (relocation_needed) relocation = h->root.u.def.value + sec->output_section->vma + sec->output_offset; else relocation = 0; } else if (h->root.type == bfd_link_hash_undefweak) relocation = 0; else if (info->shared && !info->symbolic && !info->no_undefined) relocation = 0; else { if (!((*info->callbacks->undefined_symbol) (info, h->root.root.string, input_bfd, input_section, rel->r_offset, (!info->shared || info->no_undefined)))) return false; relocation = 0; } } if (h != NULL) name = h->root.root.string; else { name = (bfd_elf_string_from_elf_section (input_bfd, symtab_hdr->sh_link, sym->st_name)); if (name == NULL || *name == '\0') name = bfd_section_name (input_bfd, sec); } r = elf32_arm_final_link_relocate (howto, input_bfd, output_bfd, input_section, contents, rel, relocation, info, sec, name, (h ? ELF_ST_TYPE (h->type) : ELF_ST_TYPE (sym->st_info)), h); if (r != bfd_reloc_ok) { const char * msg = (const char *) 0; switch (r) { case bfd_reloc_overflow: if (!((*info->callbacks->reloc_overflow) (info, name, howto->name, (bfd_vma) 0, input_bfd, input_section, rel->r_offset))) return false; break; case bfd_reloc_undefined: if (!((*info->callbacks->undefined_symbol) (info, name, input_bfd, input_section, rel->r_offset, true))) return false; break; case bfd_reloc_outofrange: msg = _ ("internal error: out of range error"); goto common_error; case bfd_reloc_notsupported: msg = _ ("internal error: unsupported relocation error"); goto common_error; case bfd_reloc_dangerous: msg = _ ("internal error: dangerous error"); goto common_error; default: msg = _ ("internal error: unknown error"); /* fall through */ common_error: if (!((*info->callbacks->warning) (info, msg, name, input_bfd, input_section, rel->r_offset))) return false; break; } } } return true; } /* Function to keep ARM specific flags in the ELF header. */ static boolean elf32_arm_set_private_flags (abfd, flags) bfd *abfd; flagword flags; { if (elf_flags_init (abfd) && elf_elfheader (abfd)->e_flags != flags) { if (EF_ARM_EABI_VERSION (flags) == EF_ARM_EABI_UNKNOWN) { if (flags & EF_INTERWORK) _bfd_error_handler (_ ("\ Warning: Not setting interwork flag of %s since it has already been specified as non-interworking"), bfd_get_filename (abfd)); else _bfd_error_handler (_ ("\ Warning: Clearing the interwork flag of %s due to outside request"), bfd_get_filename (abfd)); } } else { elf_elfheader (abfd)->e_flags = flags; elf_flags_init (abfd) = true; } return true; } /* Copy backend specific data from one object module to another. */ static boolean elf32_arm_copy_private_bfd_data (ibfd, obfd) bfd *ibfd; bfd *obfd; { flagword in_flags; flagword out_flags; if ( bfd_get_flavour (ibfd) != bfd_target_elf_flavour || bfd_get_flavour (obfd) != bfd_target_elf_flavour) return true; in_flags = elf_elfheader (ibfd)->e_flags; out_flags = elf_elfheader (obfd)->e_flags; if (elf_flags_init (obfd) && EF_ARM_EABI_VERSION (out_flags) == EF_ARM_EABI_UNKNOWN && in_flags != out_flags) { /* Cannot mix PIC and non-PIC code. */ if ((in_flags & EF_PIC) != (out_flags & EF_PIC)) return false; /* Cannot mix APCS26 and APCS32 code. */ if ((in_flags & EF_APCS_26) != (out_flags & EF_APCS_26)) return false; /* Cannot mix float APCS and non-float APCS code. */ if ((in_flags & EF_APCS_FLOAT) != (out_flags & EF_APCS_FLOAT)) return false; /* If the src and dest have different interworking flags then turn off the interworking bit. */ if ((in_flags & EF_INTERWORK) != (out_flags & EF_INTERWORK)) { if (out_flags & EF_INTERWORK) _bfd_error_handler (_ ("\ Warning: Clearing the interwork flag in %s because non-interworking code in %s has been linked with it"), bfd_get_filename (obfd), bfd_get_filename (ibfd)); in_flags &= ~EF_INTERWORK; } } elf_elfheader (obfd)->e_flags = in_flags; elf_flags_init (obfd) = true; return true; } /* Merge backend specific data from an object file to the output object file when linking. */ static boolean elf32_arm_merge_private_bfd_data (ibfd, obfd) bfd * ibfd; bfd * obfd; { flagword out_flags; flagword in_flags; if ( bfd_get_flavour (ibfd) != bfd_target_elf_flavour || bfd_get_flavour (obfd) != bfd_target_elf_flavour) return true; /* Check if we have the same endianess */ if ( ibfd->xvec->byteorder != obfd->xvec->byteorder && obfd->xvec->byteorder != BFD_ENDIAN_UNKNOWN && ibfd->xvec->byteorder != BFD_ENDIAN_UNKNOWN) { (*_bfd_error_handler) (_("%s: compiled for a %s endian system and target is %s endian"), bfd_get_filename (ibfd), bfd_big_endian (ibfd) ? "big" : "little", bfd_big_endian (obfd) ? "big" : "little"); bfd_set_error (bfd_error_wrong_format); return false; } /* The input BFD must have had its flags initialised. */ /* The following seems bogus to me -- The flags are initialized in the assembler but I don't think an elf_flags_init field is written into the object */ /* BFD_ASSERT (elf_flags_init (ibfd)); */ in_flags = elf_elfheader (ibfd)->e_flags; out_flags = elf_elfheader (obfd)->e_flags; if (!elf_flags_init (obfd)) { /* If the input is the default architecture then do not bother setting the flags for the output architecture, instead allow future merges to do this. If no future merges ever set these flags then they will retain their unitialised values, which surprise surprise, correspond to the default values. */ if (bfd_get_arch_info (ibfd)->the_default) return true; elf_flags_init (obfd) = true; elf_elfheader (obfd)->e_flags = in_flags; if (bfd_get_arch (obfd) == bfd_get_arch (ibfd) && bfd_get_arch_info (obfd)->the_default) return bfd_set_arch_mach (obfd, bfd_get_arch (ibfd), bfd_get_mach (ibfd)); return true; } /* Check flag compatibility. */ if (in_flags == out_flags) return true; /* Complain about various flag mismatches. */ if (EF_ARM_EABI_VERSION (in_flags) != EF_ARM_EABI_VERSION (out_flags)) { _bfd_error_handler (_("\ Error: %s compiled for EABI version %d, whereas %s is compiled for version %d"), bfd_get_filename (ibfd), (in_flags & EF_ARM_EABIMASK) >> 24, bfd_get_filename (obfd), (out_flags & EF_ARM_EABIMASK) >> 24); } else if (EF_ARM_EABI_VERSION (in_flags) != EF_ARM_EABI_UNKNOWN) /* Not sure what needs to be checked for EABI versions >= 1. */ return true; if ((in_flags & EF_APCS_26) != (out_flags & EF_APCS_26)) _bfd_error_handler (_ ("\ Error: %s compiled for APCS-%d, whereas %s is compiled for APCS-%d"), bfd_get_filename (ibfd), in_flags & EF_APCS_26 ? 26 : 32, bfd_get_filename (obfd), out_flags & EF_APCS_26 ? 26 : 32); if ((in_flags & EF_APCS_FLOAT) != (out_flags & EF_APCS_FLOAT)) _bfd_error_handler (_ ("\ Error: %s passes floats in %s registers, whereas %s passes them in %s registers"), bfd_get_filename (ibfd), in_flags & EF_APCS_FLOAT ? _ ("float") : _ ("integer"), bfd_get_filename (obfd), out_flags & EF_APCS_26 ? _ ("float") : _ ("integer")); if ((in_flags & EF_PIC) != (out_flags & EF_PIC)) _bfd_error_handler (_ ("\ Error: %s is compiled as position %s code, whereas %s is not"), bfd_get_filename (ibfd), in_flags & EF_PIC ? _ ("independent") : _ ("dependent"), bfd_get_filename (obfd)); /* Interworking mismatch is only a warning. */ if ((in_flags & EF_INTERWORK) != (out_flags & EF_INTERWORK)) { _bfd_error_handler (_ ("\ Warning: %s %s interworking, whereas %s %s"), bfd_get_filename (ibfd), in_flags & EF_INTERWORK ? _ ("supports") : _ ("does not support"), bfd_get_filename (obfd), out_flags & EF_INTERWORK ? _ ("does not") : _ ("does")); return true; } return false; } /* Display the flags field */ static boolean elf32_arm_print_private_bfd_data (abfd, ptr) bfd *abfd; PTR ptr; { FILE * file = (FILE *) ptr; unsigned long flags; BFD_ASSERT (abfd != NULL && ptr != NULL); /* Print normal ELF private data. */ _bfd_elf_print_private_bfd_data (abfd, ptr); flags = elf_elfheader (abfd)->e_flags; /* Ignore init flag - it may not be set, despite the flags field containing valid data. */ /* xgettext:c-format */ fprintf (file, _ ("private flags = %lx:"), elf_elfheader (abfd)->e_flags); switch (EF_ARM_EABI_VERSION (flags)) { case EF_ARM_EABI_UNKNOWN: /* The following flag bits are GNU extenstions and not part of the official ARM ELF extended ABI. Hence they are only decoded if the EABI version is not set. */ if (flags & EF_INTERWORK) fprintf (file, _ (" [interworking enabled]")); if (flags & EF_APCS_26) fprintf (file, _ (" [APCS-26]")); else fprintf (file, _ (" [APCS-32]")); if (flags & EF_APCS_FLOAT) fprintf (file, _ (" [floats passed in float registers]")); if (flags & EF_PIC) fprintf (file, _ (" [position independent]")); if (flags & EF_NEW_ABI) fprintf (file, _ (" [new ABI]")); if (flags & EF_OLD_ABI) fprintf (file, _ (" [old ABI]")); if (flags & EF_SOFT_FLOAT) fprintf (file, _ (" [software FP]")); flags &= ~(EF_INTERWORK | EF_APCS_26 | EF_APCS_FLOAT | EF_PIC | EF_NEW_ABI | EF_OLD_ABI | EF_SOFT_FLOAT); break; case EF_ARM_EABI_VER1: fprintf (file, _ (" [Version1 EABI]")); if (flags & EF_ARM_SYMSARESORTED) fprintf (file, _ (" [sorted symbol table]")); else fprintf (file, _ (" [unsorted symbol table]")); flags &= ~ EF_ARM_SYMSARESORTED; break; default: fprintf (file, _ (" <EABI version unrecognised>")); break; } flags &= ~ EF_ARM_EABIMASK; if (flags & EF_ARM_RELEXEC) fprintf (file, _ (" [relocatable executable]")); if (flags & EF_ARM_HASENTRY) fprintf (file, _ (" [has entry point]")); flags &= ~ (EF_ARM_RELEXEC | EF_ARM_HASENTRY); if (flags) fprintf (file, _ ("<Unrecognised flag bits set>")); fputc ('\n', file); return true; } static int elf32_arm_get_symbol_type (elf_sym, type) Elf_Internal_Sym * elf_sym; int type; { switch (ELF_ST_TYPE (elf_sym->st_info)) { case STT_ARM_TFUNC: return ELF_ST_TYPE (elf_sym->st_info); case STT_ARM_16BIT: /* If the symbol is not an object, return the STT_ARM_16BIT flag. This allows us to distinguish between data used by Thumb instructions and non-data (which is probably code) inside Thumb regions of an executable. */ if (type != STT_OBJECT) return ELF_ST_TYPE (elf_sym->st_info); break; default: break; } return type; } static asection * elf32_arm_gc_mark_hook (abfd, info, rel, h, sym) bfd *abfd; struct bfd_link_info *info ATTRIBUTE_UNUSED; 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_ARM_GNU_VTINHERIT: case R_ARM_GNU_VTENTRY: break; default: switch (h->root.type) { case bfd_link_hash_defined: case bfd_link_hash_defweak: return h->root.u.def.section; case bfd_link_hash_common: return h->root.u.c.p->section; default: break; } } } else { if (!(elf_bad_symtab (abfd) && ELF_ST_BIND (sym->st_info) != STB_LOCAL) && ! ((sym->st_shndx <= 0 || sym->st_shndx >= SHN_LORESERVE) && sym->st_shndx != SHN_COMMON)) { return bfd_section_from_elf_index (abfd, sym->st_shndx); } } return NULL; } /* Update the got entry reference counts for the section being removed. */ static boolean elf32_arm_gc_sweep_hook (abfd, info, sec, relocs) bfd *abfd ATTRIBUTE_UNUSED; struct bfd_link_info *info ATTRIBUTE_UNUSED; asection *sec ATTRIBUTE_UNUSED; const Elf_Internal_Rela *relocs ATTRIBUTE_UNUSED; { /* We don't support garbage collection of GOT and PLT relocs yet. */ return true; } /* Look through the relocs for a section during the first phase. */ static boolean elf32_arm_check_relocs (abfd, info, sec, 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; struct elf_link_hash_entry ** sym_hashes_end; const Elf_Internal_Rela * rel; const Elf_Internal_Rela * rel_end; bfd * dynobj; asection * sgot, *srelgot, *sreloc; bfd_vma * local_got_offsets; if (info->relocateable) return true; sgot = srelgot = sreloc = NULL; dynobj = elf_hash_table (info)->dynobj; local_got_offsets = elf_local_got_offsets (abfd); symtab_hdr = &elf_tdata (abfd)->symtab_hdr; sym_hashes = elf_sym_hashes (abfd); sym_hashes_end = sym_hashes + symtab_hdr->sh_size/sizeof(Elf32_External_Sym); if (!elf_bad_symtab (abfd)) sym_hashes_end -= symtab_hdr->sh_info; 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]; /* Some relocs require a global offset table. */ if (dynobj == NULL) { switch (ELF32_R_TYPE (rel->r_info)) { case R_ARM_GOT32: case R_ARM_GOTOFF: case R_ARM_GOTPC: elf_hash_table (info)->dynobj = dynobj = abfd; if (! _bfd_elf_create_got_section (dynobj, info)) return false; break; default: break; } } switch (ELF32_R_TYPE (rel->r_info)) { case R_ARM_GOT32: /* This symbol requires a global offset table entry. */ if (sgot == NULL) { sgot = bfd_get_section_by_name (dynobj, ".got"); BFD_ASSERT (sgot != NULL); } /* Get the got relocation section if necessary. */ if (srelgot == NULL && (h != NULL || info->shared)) { srelgot = bfd_get_section_by_name (dynobj, ".rel.got"); /* If no got relocation section, make one and initialize. */ if (srelgot == NULL) { srelgot = bfd_make_section (dynobj, ".rel.got"); if (srelgot == NULL || ! bfd_set_section_flags (dynobj, srelgot, (SEC_ALLOC | SEC_LOAD | SEC_HAS_CONTENTS | SEC_IN_MEMORY | SEC_LINKER_CREATED | SEC_READONLY)) || ! bfd_set_section_alignment (dynobj, srelgot, 2)) return false; } } if (h != NULL) { if (h->got.offset != (bfd_vma) -1) /* We have already allocated space in the .got. */ break; h->got.offset = sgot->_raw_size; /* Make sure this symbol is output as a dynamic symbol. */ if (h->dynindx == -1) if (! bfd_elf32_link_record_dynamic_symbol (info, h)) return false; srelgot->_raw_size += sizeof (Elf32_External_Rel); } else { /* This is a global offset table entry for a local symbol. */ if (local_got_offsets == NULL) { size_t size; register unsigned int i; size = symtab_hdr->sh_info * sizeof (bfd_vma); local_got_offsets = (bfd_vma *) bfd_alloc (abfd, size); if (local_got_offsets == NULL) return false; elf_local_got_offsets (abfd) = local_got_offsets; for (i = 0; i < symtab_hdr->sh_info; i++) local_got_offsets[i] = (bfd_vma) -1; } if (local_got_offsets[r_symndx] != (bfd_vma) -1) /* We have already allocated space in the .got. */ break; local_got_offsets[r_symndx] = sgot->_raw_size; if (info->shared) /* If we are generating a shared object, we need to output a R_ARM_RELATIVE reloc so that the dynamic linker can adjust this GOT entry. */ srelgot->_raw_size += sizeof (Elf32_External_Rel); } sgot->_raw_size += 4; break; case R_ARM_PLT32: /* This symbol requires a procedure linkage table entry. We actually build the entry in adjust_dynamic_symbol, because this might be a case of linking PIC code which is never referenced by a dynamic object, in which case we don't need to generate a procedure linkage table entry after all. */ /* If this is a local symbol, we resolve it directly without creating a procedure linkage table entry. */ if (h == NULL) continue; h->elf_link_hash_flags |= ELF_LINK_HASH_NEEDS_PLT; break; case R_ARM_ABS32: case R_ARM_REL32: case R_ARM_PC24: /* If we are creating a shared library, and this is a reloc against a global symbol, or a non PC relative reloc against a local symbol, then we need to copy the reloc into the shared library. However, if we are linking with -Bsymbolic, we do not need to copy a reloc against a global symbol which is defined in an object we are including in the link (i.e., DEF_REGULAR is set). At this point we have not seen all the input files, so it is possible that DEF_REGULAR is not set now but will be set later (it is never cleared). We account for that possibility below by storing information in the pcrel_relocs_copied field of the hash table entry. */ if (info->shared && (ELF32_R_TYPE (rel->r_info) != R_ARM_PC24 || (h != NULL && (! info->symbolic || (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)))) { /* When creating a shared object, we must copy these reloc types into the output file. We create a reloc section in dynobj and make room for this reloc. */ if (sreloc == NULL) { const char * name; name = (bfd_elf_string_from_elf_section (abfd, elf_elfheader (abfd)->e_shstrndx, elf_section_data (sec)->rel_hdr.sh_name)); if (name == NULL) return false; BFD_ASSERT (strncmp (name, ".rel", 4) == 0 && strcmp (bfd_get_section_name (abfd, sec), name + 4) == 0); sreloc = bfd_get_section_by_name (dynobj, name); if (sreloc == NULL) { flagword flags; sreloc = bfd_make_section (dynobj, name); flags = (SEC_HAS_CONTENTS | SEC_READONLY | SEC_IN_MEMORY | SEC_LINKER_CREATED); if ((sec->flags & SEC_ALLOC) != 0) flags |= SEC_ALLOC | SEC_LOAD; if (sreloc == NULL || ! bfd_set_section_flags (dynobj, sreloc, flags) || ! bfd_set_section_alignment (dynobj, sreloc, 2)) return false; } } sreloc->_raw_size += sizeof (Elf32_External_Rel); /* If we are linking with -Bsymbolic, and this is a global symbol, we count the number of PC relative relocations we have entered for this symbol, so that we can discard them again if the symbol is later defined by a regular object. Note that this function is only called if we are using an elf_i386 linker hash table, which means that h is really a pointer to an elf_i386_link_hash_entry. */ if (h != NULL && info->symbolic && ELF32_R_TYPE (rel->r_info) == R_ARM_PC24) { struct elf32_arm_link_hash_entry * eh; struct elf32_arm_pcrel_relocs_copied * p; eh = (struct elf32_arm_link_hash_entry *) h; for (p = eh->pcrel_relocs_copied; p != NULL; p = p->next) if (p->section == sreloc) break; if (p == NULL) { p = ((struct elf32_arm_pcrel_relocs_copied *) bfd_alloc (dynobj, sizeof * p)); if (p == NULL) return false; p->next = eh->pcrel_relocs_copied; eh->pcrel_relocs_copied = p; p->section = sreloc; p->count = 0; } ++p->count; } } break; /* This relocation describes the C++ object vtable hierarchy. Reconstruct it for later use during GC. */ case R_ARM_GNU_VTINHERIT: if (!_bfd_elf32_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_ARM_GNU_VTENTRY: if (!_bfd_elf32_gc_record_vtentry (abfd, sec, h, rel->r_offset)) return false; break; } } return true; } /* Find the nearest line to a particular section and offset, for error reporting. This code is a duplicate of the code in elf.c, except that it also accepts STT_ARM_TFUNC as a symbol that names a function. */ static boolean elf32_arm_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; { boolean found; const char * filename; asymbol * func; bfd_vma low_func; asymbol ** p; if (_bfd_dwarf2_find_nearest_line (abfd, section, symbols, offset, filename_ptr, functionname_ptr, line_ptr, 0)) return true; if (! _bfd_stab_section_find_nearest_line (abfd, symbols, section, offset, &found, filename_ptr, functionname_ptr, line_ptr, &elf_tdata (abfd)->line_info)) return false; if (found) return true; if (symbols == NULL) return false; filename = NULL; func = NULL; low_func = 0; for (p = symbols; *p != NULL; p++) { elf_symbol_type *q; q = (elf_symbol_type *) *p; if (bfd_get_section (&q->symbol) != section) continue; switch (ELF_ST_TYPE (q->internal_elf_sym.st_info)) { default: break; case STT_FILE: filename = bfd_asymbol_name (&q->symbol); break; case STT_NOTYPE: case STT_FUNC: case STT_ARM_TFUNC: if (q->symbol.section == section && q->symbol.value >= low_func && q->symbol.value <= offset) { func = (asymbol *) q; low_func = q->symbol.value; } break; } } if (func == NULL) return false; *filename_ptr = filename; *functionname_ptr = bfd_asymbol_name (func); *line_ptr = 0; return true; } /* Adjust a symbol defined by a dynamic object and referenced by a regular object. The current definition is in some section of the dynamic object, but we're not including those sections. We have to change the definition to something the rest of the link can understand. */ static boolean elf32_arm_adjust_dynamic_symbol (info, h) struct bfd_link_info * info; struct elf_link_hash_entry * h; { bfd * dynobj; asection * s; unsigned int power_of_two; dynobj = elf_hash_table (info)->dynobj; /* Make sure we know what is going on here. */ BFD_ASSERT (dynobj != NULL && ((h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_PLT) || h->weakdef != NULL || ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0 && (h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR) != 0 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0))); /* If this is a function, put it in the procedure linkage table. We will fill in the contents of the procedure linkage table later, when we know the address of the .got section. */ if (h->type == STT_FUNC || (h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_PLT) != 0) { if (! info->shared && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) == 0 && (h->elf_link_hash_flags & ELF_LINK_HASH_REF_DYNAMIC) == 0) { /* This case can occur if we saw a PLT32 reloc in an input file, but the symbol was never referred to by a dynamic object. In such a case, we don't actually need to build a procedure linkage table, and we can just do a PC32 reloc instead. */ BFD_ASSERT ((h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_PLT) != 0); return true; } /* Make sure this symbol is output as a dynamic symbol. */ if (h->dynindx == -1) { if (! bfd_elf32_link_record_dynamic_symbol (info, h)) return false; } s = bfd_get_section_by_name (dynobj, ".plt"); BFD_ASSERT (s != NULL); /* If this is the first .plt entry, make room for the special first entry. */ if (s->_raw_size == 0) s->_raw_size += PLT_ENTRY_SIZE; /* If this symbol is not defined in a regular file, and we are not generating a shared library, then set the symbol to this location in the .plt. This is required to make function pointers compare as equal between the normal executable and the shared library. */ if (! info->shared && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0) { h->root.u.def.section = s; h->root.u.def.value = s->_raw_size; } h->plt.offset = s->_raw_size; /* Make room for this entry. */ s->_raw_size += PLT_ENTRY_SIZE; /* We also need to make an entry in the .got.plt section, which will be placed in the .got section by the linker script. */ s = bfd_get_section_by_name (dynobj, ".got.plt"); BFD_ASSERT (s != NULL); s->_raw_size += 4; /* We also need to make an entry in the .rel.plt section. */ s = bfd_get_section_by_name (dynobj, ".rel.plt"); BFD_ASSERT (s != NULL); s->_raw_size += sizeof (Elf32_External_Rel); return true; } /* If this is a weak symbol, and there is a real definition, the processor independent code will have arranged for us to see the real definition first, and we can just use the same value. */ if (h->weakdef != NULL) { BFD_ASSERT (h->weakdef->root.type == bfd_link_hash_defined || h->weakdef->root.type == bfd_link_hash_defweak); h->root.u.def.section = h->weakdef->root.u.def.section; h->root.u.def.value = h->weakdef->root.u.def.value; return true; } /* This is a reference to a symbol defined by a dynamic object which is not a function. */ /* If we are creating a shared library, we must presume that the only references to the symbol are via the global offset table. For such cases we need not do anything here; the relocations will be handled correctly by relocate_section. */ if (info->shared) return true; /* We must allocate the symbol in our .dynbss section, which will become part of the .bss section of the executable. There will be an entry for this symbol in the .dynsym section. The dynamic object will contain position independent code, so all references from the dynamic object to this symbol will go through the global offset table. The dynamic linker will use the .dynsym entry to determine the address it must put in the global offset table, so both the dynamic object and the regular object will refer to the same memory location for the variable. */ s = bfd_get_section_by_name (dynobj, ".dynbss"); BFD_ASSERT (s != NULL); /* We must generate a R_ARM_COPY reloc to tell the dynamic linker to copy the initial value out of the dynamic object and into the runtime process image. We need to remember the offset into the .rel.bss section we are going to use. */ if ((h->root.u.def.section->flags & SEC_ALLOC) != 0) { asection *srel; srel = bfd_get_section_by_name (dynobj, ".rel.bss"); BFD_ASSERT (srel != NULL); srel->_raw_size += sizeof (Elf32_External_Rel); h->elf_link_hash_flags |= ELF_LINK_HASH_NEEDS_COPY; } /* We need to figure out the alignment required for this symbol. I have no idea how ELF linkers handle this. */ power_of_two = bfd_log2 (h->size); if (power_of_two > 3) power_of_two = 3; /* Apply the required alignment. */ s->_raw_size = BFD_ALIGN (s->_raw_size, (bfd_size_type) (1 << power_of_two)); if (power_of_two > bfd_get_section_alignment (dynobj, s)) { if (! bfd_set_section_alignment (dynobj, s, power_of_two)) return false; } /* Define the symbol as being at this point in the section. */ h->root.u.def.section = s; h->root.u.def.value = s->_raw_size; /* Increment the section size to make room for the symbol. */ s->_raw_size += h->size; return true; } /* Set the sizes of the dynamic sections. */ static boolean elf32_arm_size_dynamic_sections (output_bfd, info) bfd * output_bfd; struct bfd_link_info * info; { bfd * dynobj; asection * s; boolean plt; boolean relocs; boolean reltext; dynobj = elf_hash_table (info)->dynobj; BFD_ASSERT (dynobj != NULL); if (elf_hash_table (info)->dynamic_sections_created) { /* Set the contents of the .interp section to the interpreter. */ if (! info->shared) { s = bfd_get_section_by_name (dynobj, ".interp"); BFD_ASSERT (s != NULL); s->_raw_size = sizeof ELF_DYNAMIC_INTERPRETER; s->contents = (unsigned char *) ELF_DYNAMIC_INTERPRETER; } } else { /* We may have created entries in the .rel.got section. However, if we are not creating the dynamic sections, we will not actually use these entries. Reset the size of .rel.got, which will cause it to get stripped from the output file below. */ s = bfd_get_section_by_name (dynobj, ".rel.got"); if (s != NULL) s->_raw_size = 0; } /* If this is a -Bsymbolic shared link, then we need to discard all PC relative relocs against symbols defined in a regular object. We allocated space for them in the check_relocs routine, but we will not fill them in in the relocate_section routine. */ if (info->shared && info->symbolic) elf32_arm_link_hash_traverse (elf32_arm_hash_table (info), elf32_arm_discard_copies, (PTR) NULL); /* The check_relocs and adjust_dynamic_symbol entry points have determined the sizes of the various dynamic sections. Allocate memory for them. */ plt = false; relocs = false; reltext = false; for (s = dynobj->sections; s != NULL; s = s->next) { const char * name; boolean strip; if ((s->flags & SEC_LINKER_CREATED) == 0) continue; /* It's OK to base decisions on the section name, because none of the dynobj section names depend upon the input files. */ name = bfd_get_section_name (dynobj, s); strip = false; if (strcmp (name, ".plt") == 0) { if (s->_raw_size == 0) { /* Strip this section if we don't need it; see the comment below. */ strip = true; } else { /* Remember whether there is a PLT. */ plt = true; } } else if (strncmp (name, ".rel", 4) == 0) { if (s->_raw_size == 0) { /* If we don't need this section, strip it from the output file. This is mostly to handle .rel.bss and .rel.plt. We must create both sections in create_dynamic_sections, because they must be created before the linker maps input sections to output sections. The linker does that before adjust_dynamic_symbol is called, and it is that function which decides whether anything needs to go into these sections. */ strip = true; } else { asection * target; /* Remember whether there are any reloc sections other than .rel.plt. */ if (strcmp (name, ".rel.plt") != 0) { const char *outname; relocs = true; /* If this relocation section applies to a read only section, then we probably need a DT_TEXTREL entry. The entries in the .rel.plt section really apply to the .got section, which we created ourselves and so know is not readonly. */ outname = bfd_get_section_name (output_bfd, s->output_section); target = bfd_get_section_by_name (output_bfd, outname + 4); if (target != NULL && (target->flags & SEC_READONLY) != 0 && (target->flags & SEC_ALLOC) != 0) reltext = true; } /* We use the reloc_count field as a counter if we need to copy relocs into the output file. */ s->reloc_count = 0; } } else if (strncmp (name, ".got", 4) != 0) { /* It's not one of our sections, so don't allocate space. */ continue; } if (strip) { asection ** spp; for (spp = &s->output_section->owner->sections; *spp != s->output_section; spp = &(*spp)->next) ; *spp = s->output_section->next; --s->output_section->owner->section_count; continue; } /* Allocate memory for the section contents. */ s->contents = (bfd_byte *) bfd_zalloc (dynobj, s->_raw_size); if (s->contents == NULL && s->_raw_size != 0) return false; } if (elf_hash_table (info)->dynamic_sections_created) { /* Add some entries to the .dynamic section. We fill in the values later, in elf32_arm_finish_dynamic_sections, but we must add the entries now so that we get the correct size for the .dynamic section. The DT_DEBUG entry is filled in by the dynamic linker and used by the debugger. */ if (! info->shared) { if (! bfd_elf32_add_dynamic_entry (info, DT_DEBUG, 0)) return false; } if (plt) { if (! bfd_elf32_add_dynamic_entry (info, DT_PLTGOT, 0) || ! bfd_elf32_add_dynamic_entry (info, DT_PLTRELSZ, 0) || ! bfd_elf32_add_dynamic_entry (info, DT_PLTREL, DT_REL) || ! bfd_elf32_add_dynamic_entry (info, DT_JMPREL, 0)) return false; } if (relocs) { if (! bfd_elf32_add_dynamic_entry (info, DT_REL, 0) || ! bfd_elf32_add_dynamic_entry (info, DT_RELSZ, 0) || ! bfd_elf32_add_dynamic_entry (info, DT_RELENT, sizeof (Elf32_External_Rel))) return false; } if (reltext) { if (! bfd_elf32_add_dynamic_entry (info, DT_TEXTREL, 0)) return false; } } return true; } /* This function is called via elf32_arm_link_hash_traverse if we are creating a shared object with -Bsymbolic. It discards the space allocated to copy PC relative relocs against symbols which are defined in regular objects. We allocated space for them in the check_relocs routine, but we won't fill them in in the relocate_section routine. */ static boolean elf32_arm_discard_copies (h, ignore) struct elf32_arm_link_hash_entry * h; PTR ignore ATTRIBUTE_UNUSED; { struct elf32_arm_pcrel_relocs_copied * s; /* We only discard relocs for symbols defined in a regular object. */ if ((h->root.elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0) return true; for (s = h->pcrel_relocs_copied; s != NULL; s = s->next) s->section->_raw_size -= s->count * sizeof (Elf32_External_Rel); return true; } /* Finish up dynamic symbol handling. We set the contents of various dynamic sections here. */ static boolean elf32_arm_finish_dynamic_symbol (output_bfd, info, h, sym) bfd * output_bfd; struct bfd_link_info * info; struct elf_link_hash_entry * h; Elf_Internal_Sym * sym; { bfd * dynobj; dynobj = elf_hash_table (info)->dynobj; if (h->plt.offset != (bfd_vma) -1) { asection * splt; asection * sgot; asection * srel; bfd_vma plt_index; bfd_vma got_offset; Elf_Internal_Rel rel; /* This symbol has an entry in the procedure linkage table. Set it up. */ BFD_ASSERT (h->dynindx != -1); splt = bfd_get_section_by_name (dynobj, ".plt"); sgot = bfd_get_section_by_name (dynobj, ".got.plt"); srel = bfd_get_section_by_name (dynobj, ".rel.plt"); BFD_ASSERT (splt != NULL && sgot != NULL && srel != NULL); /* Get the index in the procedure linkage table which corresponds to this symbol. This is the index of this symbol in all the symbols for which we are making plt entries. The first entry in the procedure linkage table is reserved. */ plt_index = h->plt.offset / PLT_ENTRY_SIZE - 1; /* Get the offset into the .got table of the entry that corresponds to this function. Each .got entry is 4 bytes. The first three are reserved. */ got_offset = (plt_index + 3) * 4; /* Fill in the entry in the procedure linkage table. */ memcpy (splt->contents + h->plt.offset, elf32_arm_plt_entry, PLT_ENTRY_SIZE); bfd_put_32 (output_bfd, (sgot->output_section->vma + sgot->output_offset + got_offset - splt->output_section->vma - splt->output_offset - h->plt.offset - 12), splt->contents + h->plt.offset + 12); /* Fill in the entry in the global offset table. */ bfd_put_32 (output_bfd, (splt->output_section->vma + splt->output_offset), sgot->contents + got_offset); /* Fill in the entry in the .rel.plt section. */ rel.r_offset = (sgot->output_section->vma + sgot->output_offset + got_offset); rel.r_info = ELF32_R_INFO (h->dynindx, R_ARM_JUMP_SLOT); bfd_elf32_swap_reloc_out (output_bfd, &rel, ((Elf32_External_Rel *) srel->contents + plt_index)); if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0) { /* Mark the symbol as undefined, rather than as defined in the .plt section. Leave the value alone. */ sym->st_shndx = SHN_UNDEF; } } if (h->got.offset != (bfd_vma) -1) { asection * sgot; asection * srel; Elf_Internal_Rel rel; /* This symbol has an entry in the global offset table. Set it up. */ sgot = bfd_get_section_by_name (dynobj, ".got"); srel = bfd_get_section_by_name (dynobj, ".rel.got"); BFD_ASSERT (sgot != NULL && srel != NULL); rel.r_offset = (sgot->output_section->vma + sgot->output_offset + (h->got.offset &~ 1)); /* If this is a -Bsymbolic link, and the symbol is defined locally, we just want to emit a RELATIVE reloc. The entry in the global offset table will already have been initialized in the relocate_section function. */ if (info->shared && (info->symbolic || h->dynindx == -1) && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR)) rel.r_info = ELF32_R_INFO (0, R_ARM_RELATIVE); else { bfd_put_32 (output_bfd, (bfd_vma) 0, sgot->contents + h->got.offset); rel.r_info = ELF32_R_INFO (h->dynindx, R_ARM_GLOB_DAT); } bfd_elf32_swap_reloc_out (output_bfd, &rel, ((Elf32_External_Rel *) srel->contents + srel->reloc_count)); ++srel->reloc_count; } if ((h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_COPY) != 0) { asection * s; Elf_Internal_Rel rel; /* This symbol needs a copy reloc. Set it up. */ BFD_ASSERT (h->dynindx != -1 && (h->root.type == bfd_link_hash_defined || h->root.type == bfd_link_hash_defweak)); s = bfd_get_section_by_name (h->root.u.def.section->owner, ".rel.bss"); BFD_ASSERT (s != NULL); rel.r_offset = (h->root.u.def.value + h->root.u.def.section->output_section->vma + h->root.u.def.section->output_offset); rel.r_info = ELF32_R_INFO (h->dynindx, R_ARM_COPY); bfd_elf32_swap_reloc_out (output_bfd, &rel, ((Elf32_External_Rel *) s->contents + s->reloc_count)); ++s->reloc_count; } /* Mark _DYNAMIC and _GLOBAL_OFFSET_TABLE_ as absolute. */ if (strcmp (h->root.root.string, "_DYNAMIC") == 0 || strcmp (h->root.root.string, "_GLOBAL_OFFSET_TABLE_") == 0) sym->st_shndx = SHN_ABS; return true; } /* Finish up the dynamic sections. */ static boolean elf32_arm_finish_dynamic_sections (output_bfd, info) bfd * output_bfd; struct bfd_link_info * info; { bfd * dynobj; asection * sgot; asection * sdyn; dynobj = elf_hash_table (info)->dynobj; sgot = bfd_get_section_by_name (dynobj, ".got.plt"); BFD_ASSERT (sgot != NULL); sdyn = bfd_get_section_by_name (dynobj, ".dynamic"); if (elf_hash_table (info)->dynamic_sections_created) { asection *splt; Elf32_External_Dyn *dyncon, *dynconend; splt = bfd_get_section_by_name (dynobj, ".plt"); BFD_ASSERT (splt != NULL && sdyn != NULL); dyncon = (Elf32_External_Dyn *) sdyn->contents; dynconend = (Elf32_External_Dyn *) (sdyn->contents + sdyn->_raw_size); for (; dyncon < dynconend; dyncon++) { Elf_Internal_Dyn dyn; const char * name; asection * s; bfd_elf32_swap_dyn_in (dynobj, dyncon, &dyn); switch (dyn.d_tag) { default: break; case DT_PLTGOT: name = ".got"; goto get_vma; case DT_JMPREL: name = ".rel.plt"; get_vma: s = bfd_get_section_by_name (output_bfd, name); BFD_ASSERT (s != NULL); dyn.d_un.d_ptr = s->vma; bfd_elf32_swap_dyn_out (output_bfd, &dyn, dyncon); break; case DT_PLTRELSZ: s = bfd_get_section_by_name (output_bfd, ".rel.plt"); BFD_ASSERT (s != NULL); if (s->_cooked_size != 0) dyn.d_un.d_val = s->_cooked_size; else dyn.d_un.d_val = s->_raw_size; bfd_elf32_swap_dyn_out (output_bfd, &dyn, dyncon); break; case DT_RELSZ: /* My reading of the SVR4 ABI indicates that the procedure linkage table relocs (DT_JMPREL) should be included in the overall relocs (DT_REL). This is what Solaris does. However, UnixWare can not handle that case. Therefore, we override the DT_RELSZ entry here to make it not include the JMPREL relocs. Since the linker script arranges for .rel.plt to follow all other relocation sections, we don't have to worry about changing the DT_REL entry. */ s = bfd_get_section_by_name (output_bfd, ".rel.plt"); if (s != NULL) { if (s->_cooked_size != 0) dyn.d_un.d_val -= s->_cooked_size; else dyn.d_un.d_val -= s->_raw_size; } bfd_elf32_swap_dyn_out (output_bfd, &dyn, dyncon); break; } } /* Fill in the first entry in the procedure linkage table. */ if (splt->_raw_size > 0) memcpy (splt->contents, elf32_arm_plt0_entry, PLT_ENTRY_SIZE); /* UnixWare sets the entsize of .plt to 4, although that doesn't really seem like the right value. */ elf_section_data (splt->output_section)->this_hdr.sh_entsize = 4; } /* Fill in the first three entries in the global offset table. */ if (sgot->_raw_size > 0) { if (sdyn == NULL) bfd_put_32 (output_bfd, (bfd_vma) 0, sgot->contents); else bfd_put_32 (output_bfd, sdyn->output_section->vma + sdyn->output_offset, sgot->contents); bfd_put_32 (output_bfd, (bfd_vma) 0, sgot->contents + 4); bfd_put_32 (output_bfd, (bfd_vma) 0, sgot->contents + 8); } elf_section_data (sgot->output_section)->this_hdr.sh_entsize = 4; return true; } static void elf32_arm_post_process_headers (abfd, link_info) bfd * abfd; struct bfd_link_info * link_info ATTRIBUTE_UNUSED; { Elf_Internal_Ehdr * i_ehdrp; /* Elf file header, internal form */ i_ehdrp = elf_elfheader (abfd); i_ehdrp->e_ident[EI_OSABI] = ARM_ELF_OS_ABI_VERSION; i_ehdrp->e_ident[EI_ABIVERSION] = ARM_ELF_ABI_VERSION; } #define ELF_ARCH bfd_arch_arm #define ELF_MACHINE_CODE EM_ARM #define ELF_MAXPAGESIZE 0x8000 #define bfd_elf32_bfd_copy_private_bfd_data elf32_arm_copy_private_bfd_data #define bfd_elf32_bfd_merge_private_bfd_data elf32_arm_merge_private_bfd_data #define bfd_elf32_bfd_set_private_flags elf32_arm_set_private_flags #define bfd_elf32_bfd_print_private_bfd_data elf32_arm_print_private_bfd_data #define bfd_elf32_bfd_link_hash_table_create elf32_arm_link_hash_table_create #define bfd_elf32_bfd_reloc_type_lookup elf32_arm_reloc_type_lookup #define bfd_elf32_find_nearest_line elf32_arm_find_nearest_line #define elf_backend_get_symbol_type elf32_arm_get_symbol_type #define elf_backend_gc_mark_hook elf32_arm_gc_mark_hook #define elf_backend_gc_sweep_hook elf32_arm_gc_sweep_hook #define elf_backend_check_relocs elf32_arm_check_relocs #define elf_backend_relocate_section elf32_arm_relocate_section #define elf_backend_adjust_dynamic_symbol elf32_arm_adjust_dynamic_symbol #define elf_backend_create_dynamic_sections _bfd_elf_create_dynamic_sections #define elf_backend_finish_dynamic_symbol elf32_arm_finish_dynamic_symbol #define elf_backend_finish_dynamic_sections elf32_arm_finish_dynamic_sections #define elf_backend_size_dynamic_sections elf32_arm_size_dynamic_sections #define elf_backend_post_process_headers elf32_arm_post_process_headers #define elf_backend_can_gc_sections 1 #define elf_backend_plt_readonly 1 #define elf_backend_want_got_plt 1 #define elf_backend_want_plt_sym 0 #define elf_backend_got_header_size 12 #define elf_backend_plt_header_size PLT_ENTRY_SIZE #include "elf32-target.h"
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