1 /* BFD back-end for linux flavored sparc a.out binaries.
2 Copyright (C) 1992-2016 Free Software Foundation, Inc.
4 This file is part of BFD, the Binary File Descriptor library.
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 3 of the License, or
9 (at your option) any later version.
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, write to the Free Software
18 Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
19 MA 02110-1301, USA. */
21 #define TARGET_PAGE_SIZE 4096
22 #define ZMAGIC_DISK_BLOCK_SIZE 1024
23 #define SEGMENT_SIZE TARGET_PAGE_SIZE
24 #define TEXT_START_ADDR 0x0
26 #define MACHTYPE_OK(mtype) ((mtype) == M_SPARC || (mtype) == M_UNKNOWN)
31 #include "aout/aout64.h"
32 #include "aout/stab_gnu.h"
34 #include "libaout.h" /* BFD a.out internal data structures */
36 #define DEFAULT_ARCH bfd_arch_sparc
37 /* Do not "beautify" the CONCAT* macro args. Traditional C will not
38 remove whitespace added here, and thus will fail to concatenate
40 #define MY(OP) CONCAT2 (sparc_aout_linux_,OP)
41 #define TARGETNAME "a.out-sparc-linux"
43 extern const bfd_target MY(vec);
45 /* We always generate QMAGIC files in preference to ZMAGIC files. It
46 would be possible to make this a linker option, if that ever
49 static void MY_final_link_callback
50 (bfd *, file_ptr *, file_ptr *, file_ptr *);
53 sparclinux_bfd_final_link (bfd *abfd, struct bfd_link_info *info)
55 obj_aout_subformat (abfd) = q_magic_format;
56 return NAME(aout,final_link) (abfd, info, MY_final_link_callback);
59 #define MY_bfd_final_link sparclinux_bfd_final_link
61 /* Set the machine type correctly. */
64 sparclinux_write_object_contents (bfd *abfd)
66 struct external_exec exec_bytes;
67 struct internal_exec *execp = exec_hdr (abfd);
69 N_SET_MACHTYPE (execp, M_SPARC);
71 obj_reloc_entry_size (abfd) = RELOC_STD_SIZE;
73 WRITE_HEADERS (abfd, execp);
78 #define MY_write_object_contents sparclinux_write_object_contents
79 /* Code to link against Linux a.out shared libraries. */
81 /* See if a symbol name is a reference to the global offset table. */
83 #ifndef GOT_REF_PREFIX
84 #define GOT_REF_PREFIX "__GOT_"
87 #define IS_GOT_SYM(name) (CONST_STRNEQ (name, GOT_REF_PREFIX))
89 /* See if a symbol name is a reference to the procedure linkage table. */
91 #ifndef PLT_REF_PREFIX
92 #define PLT_REF_PREFIX "__PLT_"
95 #define IS_PLT_SYM(name) (CONST_STRNEQ (name, PLT_REF_PREFIX))
97 /* This string is used to generate specialized error messages. */
100 #define NEEDS_SHRLIB "__NEEDS_SHRLIB_"
103 /* This special symbol is a set vector that contains a list of
104 pointers to fixup tables. It will be present in any dynamically
105 linked file. The linker generated fixup table should also be added
106 to the list, and it should always appear in the second slot (the
107 first one is a dummy with a magic number that is defined in
110 #ifndef SHARABLE_CONFLICTS
111 #define SHARABLE_CONFLICTS "__SHARABLE_CONFLICTS__"
114 /* We keep a list of fixups. The terminology is a bit strange, but
115 each fixup contains two 32 bit numbers. A regular fixup contains
116 an address and a pointer, and at runtime we should store the
117 address at the location pointed to by the pointer. A builtin fixup
118 contains two pointers, and we should read the address using one
119 pointer and store it at the location pointed to by the other
120 pointer. Builtin fixups come into play when we have duplicate
121 __GOT__ symbols for the same variable. The builtin fixup will copy
122 the GOT pointer from one over into the other. */
127 struct linux_link_hash_entry *h;
130 /* Nonzero if this is a jump instruction that needs to be fixed,
131 zero if this is just a pointer */
137 /* We don't need a special hash table entry structure, but we do need
138 to keep some information between linker passes, so we use a special
141 struct linux_link_hash_entry
143 struct aout_link_hash_entry root;
146 struct linux_link_hash_table
148 struct aout_link_hash_table root;
150 /* First dynamic object found in link. */
153 /* Number of fixups. */
156 /* Number of builtin fixups. */
157 size_t local_builtins;
159 /* List of fixups. */
160 struct fixup *fixup_list;
164 /* Routine to create an entry in an Linux link hash table. */
166 static struct bfd_hash_entry *
167 linux_link_hash_newfunc (struct bfd_hash_entry *entry,
168 struct bfd_hash_table *table,
171 struct linux_link_hash_entry *ret = (struct linux_link_hash_entry *) entry;
173 /* Allocate the structure if it has not already been allocated by a
175 if (ret == (struct linux_link_hash_entry *) NULL)
176 ret = ((struct linux_link_hash_entry *)
177 bfd_hash_allocate (table, sizeof (struct linux_link_hash_entry)));
179 return (struct bfd_hash_entry *) ret;
181 /* Call the allocation method of the superclass. */
182 ret = ((struct linux_link_hash_entry *)
183 NAME(aout,link_hash_newfunc) ((struct bfd_hash_entry *) ret,
187 /* Set local fields; there aren't any. */
190 return (struct bfd_hash_entry *) ret;
193 /* Create a Linux link hash table. */
195 static struct bfd_link_hash_table *
196 linux_link_hash_table_create (bfd *abfd)
198 struct linux_link_hash_table *ret;
199 bfd_size_type amt = sizeof (struct linux_link_hash_table);
201 ret = (struct linux_link_hash_table *) bfd_zmalloc (amt);
202 if (ret == (struct linux_link_hash_table *) NULL)
203 return (struct bfd_link_hash_table *) NULL;
204 if (!NAME(aout,link_hash_table_init) (&ret->root, abfd,
205 linux_link_hash_newfunc,
206 sizeof (struct linux_link_hash_entry)))
209 return (struct bfd_link_hash_table *) NULL;
212 return &ret->root.root;
215 /* Look up an entry in a Linux link hash table. */
217 #define linux_link_hash_lookup(table, string, create, copy, follow) \
218 ((struct linux_link_hash_entry *) \
219 aout_link_hash_lookup (&(table)->root, (string), (create), (copy),\
222 /* Traverse a Linux link hash table. */
224 #define linux_link_hash_traverse(table, func, info) \
225 (aout_link_hash_traverse \
227 (bfd_boolean (*) (struct aout_link_hash_entry *, void *)) (func), \
230 /* Get the Linux link hash table from the info structure. This is
233 #define linux_hash_table(p) ((struct linux_link_hash_table *) ((p)->hash))
235 /* Store the information for a new fixup. */
237 static struct fixup *
238 new_fixup (struct bfd_link_info *info,
239 struct linux_link_hash_entry *h,
245 f = (struct fixup *) bfd_hash_allocate (&info->hash->table,
246 sizeof (struct fixup));
249 f->next = linux_hash_table (info)->fixup_list;
250 linux_hash_table (info)->fixup_list = f;
253 f->builtin = builtin;
255 ++linux_hash_table (info)->fixup_count;
259 /* We come here once we realize that we are going to link to a shared
260 library. We need to create a special section that contains the
261 fixup table, and we ultimately need to add a pointer to this into
262 the set vector for SHARABLE_CONFLICTS. At this point we do not
263 know the size of the section, but that's OK - we just need to
264 create it for now. */
267 linux_link_create_dynamic_sections (bfd *abfd,
268 struct bfd_link_info *info ATTRIBUTE_UNUSED)
273 /* Note that we set the SEC_IN_MEMORY flag. */
274 flags = SEC_ALLOC | SEC_LOAD | SEC_HAS_CONTENTS | SEC_IN_MEMORY;
276 /* We choose to use the name ".linux-dynamic" for the fixup table.
278 s = bfd_make_section_with_flags (abfd, ".linux-dynamic", flags);
280 || ! bfd_set_section_alignment (abfd, s, 2))
288 /* Function to add a single symbol to the linker hash table. This is
289 a wrapper around _bfd_generic_link_add_one_symbol which handles the
290 tweaking needed for dynamic linking support. */
293 linux_add_one_symbol (struct bfd_link_info *info,
302 struct bfd_link_hash_entry **hashp)
304 struct linux_link_hash_entry *h;
307 /* Look up and see if we already have this symbol in the hash table.
308 If we do, and the defining entry is from a shared library, we
309 need to create the dynamic sections.
311 FIXME: What if abfd->xvec != info->output_bfd->xvec? We may
312 want to be able to link Linux a.out and ELF objects together,
313 but serious confusion is possible. */
317 if (! bfd_link_relocatable (info)
318 && linux_hash_table (info)->dynobj == NULL
319 && strcmp (name, SHARABLE_CONFLICTS) == 0
320 && (flags & BSF_CONSTRUCTOR) != 0
321 && abfd->xvec == info->output_bfd->xvec)
323 if (! linux_link_create_dynamic_sections (abfd, info))
325 linux_hash_table (info)->dynobj = abfd;
329 if (bfd_is_abs_section (section)
330 && abfd->xvec == info->output_bfd->xvec)
332 h = linux_link_hash_lookup (linux_hash_table (info), name, FALSE,
335 && (h->root.root.type == bfd_link_hash_defined
336 || h->root.root.type == bfd_link_hash_defweak))
341 *hashp = (struct bfd_link_hash_entry *) h;
343 f = new_fixup (info, h, value, ! IS_PLT_SYM (name));
346 f->jump = IS_PLT_SYM (name);
352 /* Do the usual procedure for adding a symbol. */
353 if (! _bfd_generic_link_add_one_symbol (info, abfd, name, flags, section,
354 value, string, copy, collect,
358 /* Insert a pointer to our table in the set vector. The dynamic
359 linker requires this information. */
364 /* Here we do our special thing to add the pointer to the
365 dynamic section in the SHARABLE_CONFLICTS set vector. */
366 s = bfd_get_section_by_name (linux_hash_table (info)->dynobj,
368 BFD_ASSERT (s != NULL);
370 if (! (_bfd_generic_link_add_one_symbol
371 (info, linux_hash_table (info)->dynobj, SHARABLE_CONFLICTS,
372 BSF_GLOBAL | BSF_CONSTRUCTOR, s, (bfd_vma) 0, NULL,
373 FALSE, FALSE, NULL)))
380 /* We will crawl the hash table and come here for every global symbol.
381 We will examine each entry and see if there are indications that we
382 need to add a fixup. There are two possible cases - one is where
383 you have duplicate definitions of PLT or GOT symbols - these will
384 have already been caught and added as "builtin" fixups. If we find
385 that the corresponding non PLT/GOT symbol is also present, we
386 convert it to a regular fixup instead.
388 This function is called via linux_link_hash_traverse. */
391 linux_tally_symbols (struct linux_link_hash_entry *h, void * data)
393 struct bfd_link_info *info = (struct bfd_link_info *) data;
394 struct fixup *f, *f1;
396 struct linux_link_hash_entry *h1, *h2;
399 if (h->root.root.type == bfd_link_hash_undefined
400 && CONST_STRNEQ (h->root.root.root.string, NEEDS_SHRLIB))
406 name = h->root.root.root.string + sizeof NEEDS_SHRLIB - 1;
407 p = strrchr (name, '_');
409 alloc = (char *) bfd_malloc ((bfd_size_type) strlen (name) + 1);
411 if (p == NULL || alloc == NULL)
412 (*_bfd_error_handler) (_("Output file requires shared library `%s'\n"),
416 strcpy (alloc, name);
417 p = strrchr (alloc, '_');
419 (*_bfd_error_handler)
420 (_("Output file requires shared library `%s.so.%s'\n"),
428 /* If this symbol is not a PLT/GOT, we do not even need to look at
430 is_plt = IS_PLT_SYM (h->root.root.root.string);
432 if (is_plt || IS_GOT_SYM (h->root.root.root.string))
434 /* Look up this symbol twice. Once just as a regular lookup,
435 and then again following all of the indirect links until we
436 reach a real symbol. */
437 h1 = linux_link_hash_lookup (linux_hash_table (info),
438 (h->root.root.root.string
439 + sizeof PLT_REF_PREFIX - 1),
441 /* h2 does not follow indirect symbols. */
442 h2 = linux_link_hash_lookup (linux_hash_table (info),
443 (h->root.root.root.string
444 + sizeof PLT_REF_PREFIX - 1),
445 FALSE, FALSE, FALSE);
447 /* The real symbol must exist but if it is also an ABS symbol,
448 there is no need to have a fixup. This is because they both
449 came from the same library. If on the other hand, we had to
450 use an indirect symbol to get to the real symbol, we add the
451 fixup anyway, since there are cases where these symbols come
452 from different shared libraries */
454 && (((h1->root.root.type == bfd_link_hash_defined
455 || h1->root.root.type == bfd_link_hash_defweak)
456 && ! bfd_is_abs_section (h1->root.root.u.def.section))
457 || h2->root.root.type == bfd_link_hash_indirect))
459 /* See if there is a "builtin" fixup already present
460 involving this symbol. If so, convert it to a regular
461 fixup. In the end, this relaxes some of the requirements
462 about the order of performing fixups. */
464 for (f1 = linux_hash_table (info)->fixup_list;
468 if ((f1->h != h && f1->h != h1)
469 || (! f1->builtin && ! f1->jump))
474 && bfd_is_abs_section (h->root.root.u.def.section))
476 f = new_fixup (info, h1, f1->h->root.root.u.def.value, 0);
485 && bfd_is_abs_section (h->root.root.u.def.section))
487 f = new_fixup (info, h1, h->root.root.u.def.value, 0);
490 /* FIXME: No way to return error. */
497 /* Quick and dirty way of stripping these symbols from the
499 if (bfd_is_abs_section (h->root.root.u.def.section))
500 h->root.written = TRUE;
506 /* This is called to set the size of the .linux-dynamic section is.
507 It is called by the Linux linker emulation before_allocation
508 routine. We have finished reading all of the input files, and now
509 we just scan the hash tables to find out how many additional fixups
513 bfd_sparclinux_size_dynamic_sections (bfd *output_bfd,
514 struct bfd_link_info *info)
519 if (output_bfd->xvec != &MY(vec))
522 /* First find the fixups... */
523 linux_link_hash_traverse (linux_hash_table (info),
527 /* If there are builtin fixups, leave room for a marker. This is
528 used by the dynamic linker so that it knows that all that follow
529 are builtin fixups instead of regular fixups. */
530 for (f = linux_hash_table (info)->fixup_list; f != NULL; f = f->next)
534 ++linux_hash_table (info)->fixup_count;
535 ++linux_hash_table (info)->local_builtins;
540 if (linux_hash_table (info)->dynobj == NULL)
542 if (linux_hash_table (info)->fixup_count > 0)
547 /* Allocate memory for our fixup table. We will fill it in later. */
548 s = bfd_get_section_by_name (linux_hash_table (info)->dynobj,
552 s->size = linux_hash_table (info)->fixup_count + 1;
554 s->contents = (bfd_byte *) bfd_zalloc (output_bfd, s->size);
555 if (s->contents == NULL)
562 /* We come here once we are ready to actually write the fixup table to
563 the output file. Scan the fixup tables and so forth and generate
564 the stuff we need. */
567 linux_finish_dynamic_link (bfd *output_bfd, struct bfd_link_info *info)
569 asection *s, *os, *is;
570 bfd_byte *fixup_table;
571 struct linux_link_hash_entry *h;
573 unsigned int new_addr;
575 unsigned int fixups_written;
577 if (linux_hash_table (info)->dynobj == NULL)
580 s = bfd_get_section_by_name (linux_hash_table (info)->dynobj,
582 BFD_ASSERT (s != NULL);
583 os = s->output_section;
586 #ifdef LINUX_LINK_DEBUG
587 printf ("Fixup table file offset: %x VMA: %x\n",
588 os->filepos + s->output_offset,
589 os->vma + s->output_offset);
592 fixup_table = s->contents;
593 bfd_put_32 (output_bfd,
594 (bfd_vma) linux_hash_table (info)->fixup_count, fixup_table);
597 /* Fill in fixup table. */
598 for (f = linux_hash_table (info)->fixup_list; f != NULL; f = f->next)
603 if (f->h->root.root.type != bfd_link_hash_defined
604 && f->h->root.root.type != bfd_link_hash_defweak)
606 (*_bfd_error_handler)
607 (_("Symbol %s not defined for fixups\n"),
608 f->h->root.root.root.string);
612 is = f->h->root.root.u.def.section;
613 section_offset = is->output_section->vma + is->output_offset;
614 new_addr = f->h->root.root.u.def.value + section_offset;
616 #ifdef LINUX_LINK_DEBUG
617 printf ("Fixup(%d) %s: %x %x\n",f->jump, f->h->root.root.string,
623 /* Relative address */
624 new_addr = new_addr - (f->value + 5);
625 bfd_put_32 (output_bfd, (bfd_vma) new_addr, fixup_table);
627 bfd_put_32 (output_bfd, f->value + 1, fixup_table);
632 bfd_put_32 (output_bfd, (bfd_vma) new_addr, fixup_table);
634 bfd_put_32 (output_bfd, f->value, fixup_table);
640 if (linux_hash_table (info)->local_builtins != 0)
642 /* Special marker so we know to switch to the other type of fixup */
643 bfd_put_32 (output_bfd, (bfd_vma) 0, fixup_table);
645 bfd_put_32 (output_bfd, (bfd_vma) 0, fixup_table);
648 for (f = linux_hash_table (info)->fixup_list; f != NULL; f = f->next)
653 if (f->h->root.root.type != bfd_link_hash_defined
654 && f->h->root.root.type != bfd_link_hash_defweak)
656 (*_bfd_error_handler)
657 (_("Symbol %s not defined for fixups\n"),
658 f->h->root.root.root.string);
662 is = f->h->root.root.u.def.section;
663 section_offset = is->output_section->vma + is->output_offset;
664 new_addr = f->h->root.root.u.def.value + section_offset;
666 #ifdef LINUX_LINK_DEBUG
667 printf ("Fixup(B) %s: %x %x\n", f->h->root.root.string,
671 bfd_put_32 (output_bfd, (bfd_vma) new_addr, fixup_table);
673 bfd_put_32 (output_bfd, f->value, fixup_table);
679 if (linux_hash_table (info)->fixup_count != fixups_written)
681 (*_bfd_error_handler) (_("Warning: fixup count mismatch\n"));
682 while (linux_hash_table (info)->fixup_count > fixups_written)
684 bfd_put_32 (output_bfd, (bfd_vma) 0, fixup_table);
686 bfd_put_32 (output_bfd, (bfd_vma) 0, fixup_table);
692 h = linux_link_hash_lookup (linux_hash_table (info),
693 "__BUILTIN_FIXUPS__",
694 FALSE, FALSE, FALSE);
697 && (h->root.root.type == bfd_link_hash_defined
698 || h->root.root.type == bfd_link_hash_defweak))
700 is = h->root.root.u.def.section;
701 section_offset = is->output_section->vma + is->output_offset;
702 new_addr = h->root.root.u.def.value + section_offset;
704 #ifdef LINUX_LINK_DEBUG
705 printf ("Builtin fixup table at %x\n", new_addr);
708 bfd_put_32 (output_bfd, (bfd_vma) new_addr, fixup_table);
711 bfd_put_32 (output_bfd, (bfd_vma) 0, fixup_table);
713 if (bfd_seek (output_bfd, (file_ptr) (os->filepos + s->output_offset),
717 if (bfd_bwrite (s->contents, s->size, output_bfd) != s->size)
723 #define MY_bfd_link_hash_table_create linux_link_hash_table_create
724 #define MY_add_one_symbol linux_add_one_symbol
725 #define MY_finish_dynamic_link linux_finish_dynamic_link
727 #define MY_zmagic_contiguous 1
729 #include "aout-target.h"