diff options
Diffstat (limited to 'bfd/i386linux.c')
-rw-r--r-- | bfd/i386linux.c | 733 |
1 files changed, 0 insertions, 733 deletions
diff --git a/bfd/i386linux.c b/bfd/i386linux.c deleted file mode 100644 index 0887ecb..0000000 --- a/bfd/i386linux.c +++ /dev/null @@ -1,733 +0,0 @@ -/* BFD back-end for linux flavored i386 a.out binaries. - Copyright (C) 1992-2018 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. */ - -#define TARGET_PAGE_SIZE 4096 -#define ZMAGIC_DISK_BLOCK_SIZE 1024 -#define SEGMENT_SIZE TARGET_PAGE_SIZE -#define TEXT_START_ADDR 0x0 - -#define MACHTYPE_OK(mtype) ((mtype) == M_386 || (mtype) == M_UNKNOWN) - -#include "sysdep.h" -#include "bfd.h" -#include "libbfd.h" -#include "aout/aout64.h" -#include "aout/stab_gnu.h" -#include "aout/ar.h" -#include "libaout.h" /* BFD a.out internal data structures */ - -#define DEFAULT_ARCH bfd_arch_i386 - -/* Do not "beautify" the CONCAT* macro args. Traditional C will not - remove whitespace added here, and thus will fail to concatenate - the tokens. */ -#define MY(OP) CONCAT2 (i386_aout_linux_,OP) -#define TARGETNAME "a.out-i386-linux" - -extern const bfd_target MY(vec); - -/* We always generate QMAGIC files in preference to ZMAGIC files. It - would be possible to make this a linker option, if that ever - becomes important. */ - -static void MY_final_link_callback - (bfd *, file_ptr *, file_ptr *, file_ptr *); -static bfd_boolean i386linux_bfd_final_link - (bfd *, struct bfd_link_info *); -static bfd_boolean i386linux_write_object_contents (bfd *); - -static bfd_boolean -i386linux_bfd_final_link (bfd *abfd, struct bfd_link_info *info) -{ - obj_aout_subformat (abfd) = q_magic_format; - return NAME(aout,final_link) (abfd, info, MY_final_link_callback); -} - -#define MY_bfd_final_link i386linux_bfd_final_link - -/* Set the machine type correctly. */ - -static bfd_boolean -i386linux_write_object_contents (bfd *abfd) -{ - struct external_exec exec_bytes; - struct internal_exec *execp = exec_hdr (abfd); - - N_SET_MACHTYPE (execp, M_386); - - obj_reloc_entry_size (abfd) = RELOC_STD_SIZE; - - WRITE_HEADERS (abfd, execp); - - return TRUE; -} - -#define MY_write_object_contents i386linux_write_object_contents - -/* Code to link against Linux a.out shared libraries. */ - -/* See if a symbol name is a reference to the global offset table. */ - -#ifndef GOT_REF_PREFIX -#define GOT_REF_PREFIX "__GOT_" -#endif - -#define IS_GOT_SYM(name) (CONST_STRNEQ (name, GOT_REF_PREFIX)) - -/* See if a symbol name is a reference to the procedure linkage table. */ - -#ifndef PLT_REF_PREFIX -#define PLT_REF_PREFIX "__PLT_" -#endif - -#define IS_PLT_SYM(name) (CONST_STRNEQ (name, PLT_REF_PREFIX)) - -/* This string is used to generate specialized error messages. */ - -#ifndef NEEDS_SHRLIB -#define NEEDS_SHRLIB "__NEEDS_SHRLIB_" -#endif - -/* This special symbol is a set vector that contains a list of - pointers to fixup tables. It will be present in any dynamically - linked file. The linker generated fixup table should also be added - to the list, and it should always appear in the second slot (the - first one is a dummy with a magic number that is defined in - crt0.o). */ - -#ifndef SHARABLE_CONFLICTS -#define SHARABLE_CONFLICTS "__SHARABLE_CONFLICTS__" -#endif - -/* We keep a list of fixups. The terminology is a bit strange, but - each fixup contains two 32 bit numbers. A regular fixup contains - an address and a pointer, and at runtime we should store the - address at the location pointed to by the pointer. A builtin fixup - contains two pointers, and we should read the address using one - pointer and store it at the location pointed to by the other - pointer. Builtin fixups come into play when we have duplicate - __GOT__ symbols for the same variable. The builtin fixup will copy - the GOT pointer from one over into the other. */ - -struct fixup -{ - struct fixup *next; - struct linux_link_hash_entry *h; - bfd_vma value; - - /* Nonzero if this is a jump instruction that needs to be fixed, - zero if this is just a pointer */ - char jump; - - char builtin; -}; - -/* We don't need a special hash table entry structure, but we do need - to keep some information between linker passes, so we use a special - hash table. */ - -struct linux_link_hash_entry -{ - struct aout_link_hash_entry root; -}; - -struct linux_link_hash_table -{ - struct aout_link_hash_table root; - - /* First dynamic object found in link. */ - bfd *dynobj; - - /* Number of fixups. */ - size_t fixup_count; - - /* Number of builtin fixups. */ - size_t local_builtins; - - /* List of fixups. */ - struct fixup *fixup_list; -}; - -/* Routine to create an entry in an Linux link hash table. */ - -static struct bfd_hash_entry * -linux_link_hash_newfunc (struct bfd_hash_entry *entry, - struct bfd_hash_table *table, - const char *string) -{ - struct linux_link_hash_entry *ret = (struct linux_link_hash_entry *) entry; - - /* Allocate the structure if it has not already been allocated by a - subclass. */ - if (ret == (struct linux_link_hash_entry *) NULL) - ret = ((struct linux_link_hash_entry *) - bfd_hash_allocate (table, sizeof (struct linux_link_hash_entry))); - if (ret == NULL) - return (struct bfd_hash_entry *) ret; - - /* Call the allocation method of the superclass. */ - ret = ((struct linux_link_hash_entry *) - NAME(aout,link_hash_newfunc) ((struct bfd_hash_entry *) ret, - table, string)); - if (ret != NULL) - { - /* Set local fields; there aren't any. */ - } - - return (struct bfd_hash_entry *) ret; -} - -/* Create a Linux link hash table. */ - -static struct bfd_link_hash_table * -linux_link_hash_table_create (bfd *abfd) -{ - struct linux_link_hash_table *ret; - bfd_size_type amt = sizeof (struct linux_link_hash_table); - - ret = (struct linux_link_hash_table *) bfd_zmalloc (amt); - if (ret == (struct linux_link_hash_table *) NULL) - return (struct bfd_link_hash_table *) NULL; - if (!NAME(aout,link_hash_table_init) (&ret->root, abfd, - linux_link_hash_newfunc, - sizeof (struct linux_link_hash_entry))) - { - free (ret); - return (struct bfd_link_hash_table *) NULL; - } - - return &ret->root.root; -} - -/* Look up an entry in a Linux link hash table. */ - -#define linux_link_hash_lookup(table, string, create, copy, follow) \ - ((struct linux_link_hash_entry *) \ - aout_link_hash_lookup (&(table)->root, (string), (create), (copy),\ - (follow))) - -/* Traverse a Linux link hash table. */ - -#define linux_link_hash_traverse(table, func, info) \ - (aout_link_hash_traverse \ - (&(table)->root, \ - (bfd_boolean (*) (struct aout_link_hash_entry *, void *)) (func), \ - (info))) - -/* Get the Linux link hash table from the info structure. This is - just a cast. */ - -#define linux_hash_table(p) ((struct linux_link_hash_table *) ((p)->hash)) - -/* Store the information for a new fixup. */ - -static struct fixup * -new_fixup (struct bfd_link_info *info, - struct linux_link_hash_entry *h, - bfd_vma value, - int builtin) -{ - struct fixup *f; - - f = (struct fixup *) bfd_hash_allocate (&info->hash->table, - sizeof (struct fixup)); - if (f == NULL) - return f; - f->next = linux_hash_table (info)->fixup_list; - linux_hash_table (info)->fixup_list = f; - f->h = h; - f->value = value; - f->builtin = builtin; - f->jump = 0; - ++linux_hash_table (info)->fixup_count; - return f; -} - -/* We come here once we realize that we are going to link to a shared - library. We need to create a special section that contains the - fixup table, and we ultimately need to add a pointer to this into - the set vector for SHARABLE_CONFLICTS. At this point we do not - know the size of the section, but that's OK - we just need to - create it for now. */ - -static bfd_boolean -linux_link_create_dynamic_sections (bfd *abfd, - struct bfd_link_info *info ATTRIBUTE_UNUSED) -{ - flagword flags; - asection *s; - - /* Note that we set the SEC_IN_MEMORY flag. */ - flags = SEC_ALLOC | SEC_LOAD | SEC_HAS_CONTENTS | SEC_IN_MEMORY; - - /* We choose to use the name ".linux-dynamic" for the fixup table. - Why not? */ - s = bfd_make_section_with_flags (abfd, ".linux-dynamic", flags); - if (s == NULL - || ! bfd_set_section_alignment (abfd, s, 2)) - return FALSE; - s->size = 0; - s->contents = 0; - - return TRUE; -} - -/* Function to add a single symbol to the linker hash table. This is - a wrapper around _bfd_generic_link_add_one_symbol which handles the - tweaking needed for dynamic linking support. */ - -static bfd_boolean -linux_add_one_symbol (struct bfd_link_info *info, - bfd *abfd, - const char *name, - flagword flags, - asection *section, - bfd_vma value, - const char *string, - bfd_boolean copy, - bfd_boolean collect, - struct bfd_link_hash_entry **hashp) -{ - struct linux_link_hash_entry *h; - bfd_boolean insert; - - /* Look up and see if we already have this symbol in the hash table. - If we do, and the defining entry is from a shared library, we - need to create the dynamic sections. - - FIXME: What if abfd->xvec != info->output_bfd->xvec? We may - want to be able to link Linux a.out and ELF objects together, - but serious confusion is possible. */ - - insert = FALSE; - - if (! bfd_link_relocatable (info) - && linux_hash_table (info)->dynobj == NULL - && strcmp (name, SHARABLE_CONFLICTS) == 0 - && (flags & BSF_CONSTRUCTOR) != 0 - && abfd->xvec == info->output_bfd->xvec) - { - if (! linux_link_create_dynamic_sections (abfd, info)) - return FALSE; - linux_hash_table (info)->dynobj = abfd; - insert = TRUE; - } - - if (bfd_is_abs_section (section) - && abfd->xvec == info->output_bfd->xvec) - { - h = linux_link_hash_lookup (linux_hash_table (info), name, FALSE, - FALSE, FALSE); - if (h != NULL - && (h->root.root.type == bfd_link_hash_defined - || h->root.root.type == bfd_link_hash_defweak)) - { - struct fixup *f; - - if (hashp != NULL) - *hashp = (struct bfd_link_hash_entry *) h; - - f = new_fixup (info, h, value, ! IS_PLT_SYM (name)); - if (f == NULL) - return FALSE; - f->jump = IS_PLT_SYM (name); - - return TRUE; - } - } - - /* Do the usual procedure for adding a symbol. */ - if (! _bfd_generic_link_add_one_symbol (info, abfd, name, flags, section, - value, string, copy, collect, - hashp)) - return FALSE; - - /* Insert a pointer to our table in the set vector. The dynamic - linker requires this information */ - if (insert) - { - asection *s; - - /* Here we do our special thing to add the pointer to the - dynamic section in the SHARABLE_CONFLICTS set vector. */ - s = bfd_get_section_by_name (linux_hash_table (info)->dynobj, - ".linux-dynamic"); - BFD_ASSERT (s != NULL); - - if (! (_bfd_generic_link_add_one_symbol - (info, linux_hash_table (info)->dynobj, SHARABLE_CONFLICTS, - BSF_GLOBAL | BSF_CONSTRUCTOR, s, (bfd_vma) 0, NULL, - FALSE, FALSE, NULL))) - return FALSE; - } - - return TRUE; -} - -/* We will crawl the hash table and come here for every global symbol. - We will examine each entry and see if there are indications that we - need to add a fixup. There are two possible cases - one is where - you have duplicate definitions of PLT or GOT symbols - these will - have already been caught and added as "builtin" fixups. If we find - that the corresponding non PLT/GOT symbol is also present, we - convert it to a regular fixup instead. - - This function is called via linux_link_hash_traverse. */ - -static bfd_boolean -linux_tally_symbols (struct linux_link_hash_entry *h, void * data) -{ - struct bfd_link_info *info = (struct bfd_link_info *) data; - struct fixup *f, *f1; - int is_plt; - struct linux_link_hash_entry *h1, *h2; - bfd_boolean exists; - - if (h->root.root.type == bfd_link_hash_undefined - && CONST_STRNEQ (h->root.root.root.string, NEEDS_SHRLIB)) - { - const char *name; - char *p; - char *alloc = NULL; - - name = h->root.root.root.string + sizeof NEEDS_SHRLIB - 1; - p = strrchr (name, '_'); - if (p != NULL) - alloc = (char *) bfd_malloc ((bfd_size_type) strlen (name) + 1); - - if (p == NULL || alloc == NULL) - _bfd_error_handler (_("output file requires shared library `%s'"), - name); - else - { - strcpy (alloc, name); - p = strrchr (alloc, '_'); - *p++ = '\0'; - _bfd_error_handler - (_("output file requires shared library `%s.so.%s'"), - alloc, p); - free (alloc); - } - - abort (); - } - - /* If this symbol is not a PLT/GOT, we do not even need to look at it */ - is_plt = IS_PLT_SYM (h->root.root.root.string); - - if (is_plt || IS_GOT_SYM (h->root.root.root.string)) - { - /* Look up this symbol twice. Once just as a regular lookup, - and then again following all of the indirect links until we - reach a real symbol. */ - h1 = linux_link_hash_lookup (linux_hash_table (info), - (h->root.root.root.string - + sizeof PLT_REF_PREFIX - 1), - FALSE, FALSE, TRUE); - /* h2 does not follow indirect symbols. */ - h2 = linux_link_hash_lookup (linux_hash_table (info), - (h->root.root.root.string - + sizeof PLT_REF_PREFIX - 1), - FALSE, FALSE, FALSE); - - /* The real symbol must exist but if it is also an ABS symbol, - there is no need to have a fixup. This is because they both - came from the same library. If on the other hand, we had to - use an indirect symbol to get to the real symbol, we add the - fixup anyway, since there are cases where these symbols come - from different shared libraries */ - if (h1 != NULL - && (((h1->root.root.type == bfd_link_hash_defined - || h1->root.root.type == bfd_link_hash_defweak) - && ! bfd_is_abs_section (h1->root.root.u.def.section)) - || h2->root.root.type == bfd_link_hash_indirect)) - { - /* See if there is a "builtin" fixup already present - involving this symbol. If so, convert it to a regular - fixup. In the end, this relaxes some of the requirements - about the order of performing fixups. */ - exists = FALSE; - for (f1 = linux_hash_table (info)->fixup_list; - f1 != NULL; - f1 = f1->next) - { - if ((f1->h != h && f1->h != h1) - || (! f1->builtin && ! f1->jump)) - continue; - if (f1->h == h1) - exists = TRUE; - if (! exists - && bfd_is_abs_section (h->root.root.u.def.section)) - { - f = new_fixup (info, h1, f1->h->root.root.u.def.value, 0); - f->jump = is_plt; - } - f1->h = h1; - f1->jump = is_plt; - f1->builtin = 0; - exists = TRUE; - } - if (! exists - && bfd_is_abs_section (h->root.root.u.def.section)) - { - f = new_fixup (info, h1, h->root.root.u.def.value, 0); - if (f == NULL) - { - /* FIXME: No way to return error. */ - abort (); - } - f->jump = is_plt; - } - } - - /* Quick and dirty way of stripping these symbols from the - symtab. */ - if (bfd_is_abs_section (h->root.root.u.def.section)) - h->root.written = TRUE; - } - - return TRUE; -} - -/* This is called to set the size of the .linux-dynamic section is. - It is called by the Linux linker emulation before_allocation - routine. We have finished reading all of the input files, and now - we just scan the hash tables to find out how many additional fixups - are required. */ - -bfd_boolean -bfd_i386linux_size_dynamic_sections (bfd *output_bfd, - struct bfd_link_info *info) -{ - struct fixup *f; - asection *s; - - if (output_bfd->xvec != &MY(vec)) - return TRUE; - - /* First find the fixups... */ - linux_link_hash_traverse (linux_hash_table (info), - linux_tally_symbols, - info); - - /* If there are builtin fixups, leave room for a marker. This is - used by the dynamic linker so that it knows that all that follow - are builtin fixups instead of regular fixups. */ - for (f = linux_hash_table (info)->fixup_list; f != NULL; f = f->next) - { - if (f->builtin) - { - ++linux_hash_table (info)->fixup_count; - ++linux_hash_table (info)->local_builtins; - break; - } - } - - if (linux_hash_table (info)->dynobj == NULL) - { - if (linux_hash_table (info)->fixup_count > 0) - abort (); - return TRUE; - } - - /* Allocate memory for our fixup table. We will fill it in later. */ - s = bfd_get_section_by_name (linux_hash_table (info)->dynobj, - ".linux-dynamic"); - if (s != NULL) - { - s->size = linux_hash_table (info)->fixup_count + 1; - s->size *= 8; - s->contents = (bfd_byte *) bfd_zalloc (output_bfd, s->size); - if (s->contents == NULL) - return FALSE; - } - - return TRUE; -} - -/* We come here once we are ready to actually write the fixup table to - the output file. Scan the fixup tables and so forth and generate - the stuff we need. */ - -static bfd_boolean -linux_finish_dynamic_link (bfd *output_bfd, - struct bfd_link_info *info) -{ - asection *s, *os, *is; - bfd_byte *fixup_table; - struct linux_link_hash_entry *h; - struct fixup *f; - unsigned int new_addr; - int section_offset; - unsigned int fixups_written; - - if (linux_hash_table (info)->dynobj == NULL) - return TRUE; - - s = bfd_get_section_by_name (linux_hash_table (info)->dynobj, - ".linux-dynamic"); - BFD_ASSERT (s != NULL); - os = s->output_section; - fixups_written = 0; - -#ifdef LINUX_LINK_DEBUG - printf ("Fixup table file offset: %x VMA: %x\n", - os->filepos + s->output_offset, - os->vma + s->output_offset); -#endif - - fixup_table = s->contents; - bfd_put_32 (output_bfd, - (bfd_vma) linux_hash_table (info)->fixup_count, fixup_table); - fixup_table += 4; - - /* Fill in fixup table. */ - for (f = linux_hash_table (info)->fixup_list; f != NULL; f = f->next) - { - if (f->builtin) - continue; - - if (f->h->root.root.type != bfd_link_hash_defined - && f->h->root.root.type != bfd_link_hash_defweak) - { - _bfd_error_handler - (_("symbol %s not defined for fixups"), - f->h->root.root.root.string); - continue; - } - - is = f->h->root.root.u.def.section; - section_offset = is->output_section->vma + is->output_offset; - new_addr = f->h->root.root.u.def.value + section_offset; - -#ifdef LINUX_LINK_DEBUG - printf ("Fixup(%d) %s: %x %x\n",f->jump, f->h->root.root.string, - new_addr, f->value); -#endif - - if (f->jump) - { - /* Relative address */ - new_addr = new_addr - (f->value + 5); - bfd_put_32 (output_bfd, (bfd_vma) new_addr, fixup_table); - fixup_table += 4; - bfd_put_32 (output_bfd, f->value + 1, fixup_table); - fixup_table += 4; - } - else - { - bfd_put_32 (output_bfd, (bfd_vma) new_addr, fixup_table); - fixup_table += 4; - bfd_put_32 (output_bfd, f->value, fixup_table); - fixup_table += 4; - } - ++fixups_written; - } - - if (linux_hash_table (info)->local_builtins != 0) - { - /* Special marker so we know to switch to the other type of fixup */ - bfd_put_32 (output_bfd, (bfd_vma) 0, fixup_table); - fixup_table += 4; - bfd_put_32 (output_bfd, (bfd_vma) 0, fixup_table); - fixup_table += 4; - ++fixups_written; - for (f = linux_hash_table (info)->fixup_list; f != NULL; f = f->next) - { - if (! f->builtin) - continue; - - if (f->h->root.root.type != bfd_link_hash_defined - && f->h->root.root.type != bfd_link_hash_defweak) - { - _bfd_error_handler - (_("symbol %s not defined for fixups"), - f->h->root.root.root.string); - continue; - } - - is = f->h->root.root.u.def.section; - section_offset = is->output_section->vma + is->output_offset; - new_addr = f->h->root.root.u.def.value + section_offset; - -#ifdef LINUX_LINK_DEBUG - printf ("Fixup(B) %s: %x %x\n", f->h->root.root.string, - new_addr, f->value); -#endif - - bfd_put_32 (output_bfd, (bfd_vma) new_addr, fixup_table); - fixup_table += 4; - bfd_put_32 (output_bfd, f->value, fixup_table); - fixup_table += 4; - ++fixups_written; - } - } - - if (linux_hash_table (info)->fixup_count != fixups_written) - { - _bfd_error_handler (_("warning: fixup count mismatch")); - while (linux_hash_table (info)->fixup_count > fixups_written) - { - bfd_put_32 (output_bfd, (bfd_vma) 0, fixup_table); - fixup_table += 4; - bfd_put_32 (output_bfd, (bfd_vma) 0, fixup_table); - fixup_table += 4; - ++fixups_written; - } - } - - h = linux_link_hash_lookup (linux_hash_table (info), - "__BUILTIN_FIXUPS__", - FALSE, FALSE, FALSE); - - if (h != NULL - && (h->root.root.type == bfd_link_hash_defined - || h->root.root.type == bfd_link_hash_defweak)) - { - is = h->root.root.u.def.section; - section_offset = is->output_section->vma + is->output_offset; - new_addr = h->root.root.u.def.value + section_offset; - -#ifdef LINUX_LINK_DEBUG - printf ("Builtin fixup table at %x\n", new_addr); -#endif - - bfd_put_32 (output_bfd, (bfd_vma) new_addr, fixup_table); - } - else - bfd_put_32 (output_bfd, (bfd_vma) 0, fixup_table); - - if (bfd_seek (output_bfd, (file_ptr) (os->filepos + s->output_offset), - SEEK_SET) != 0) - return FALSE; - - if (bfd_bwrite (s->contents, s->size, output_bfd) != s->size) - return FALSE; - - return TRUE; -} - -#define MY_bfd_link_hash_table_create linux_link_hash_table_create -#define MY_add_one_symbol linux_add_one_symbol -#define MY_finish_dynamic_link linux_finish_dynamic_link - -#define MY_zmagic_contiguous 1 - -#include "aout-target.h" |