1 /* BFD back-end for linux flavored sparc a.out binaries.
2 Copyright 1992, 1993, 1994, 1995, 1996, 1997, 2000, 2001
3 Free Software Foundation, Inc.
5 This file is part of BFD, the Binary File Descriptor library.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program; if not, write to the Free Software
19 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
22 #define TARGET_PAGE_SIZE 4096
23 #define ZMAGIC_DISK_BLOCK_SIZE 1024
24 #define SEGMENT_SIZE TARGET_PAGE_SIZE
25 #define TEXT_START_ADDR 0x0
26 #define N_SHARED_LIB(x) 0
27 #define BYTES_IN_WORD 4
29 #define MACHTYPE_OK(mtype) ((mtype) == M_SPARC || (mtype) == M_UNKNOWN)
34 #include "aout/aout64.h"
35 #include "aout/stab_gnu.h"
37 #include "libaout.h" /* BFD a.out internal data structures */
39 #define DEFAULT_ARCH bfd_arch_sparc
40 /* Do not "beautify" the CONCAT* macro args. Traditional C will not
41 remove whitespace added here, and thus will fail to concatenate
43 #define MY(OP) CONCAT2 (sparclinux_,OP)
44 #define TARGETNAME "a.out-sparc-linux"
46 extern const bfd_target
MY(vec
);
48 /* We always generate QMAGIC files in preference to ZMAGIC files. It
49 would be possible to make this a linker option, if that ever
52 static void MY_final_link_callback
53 PARAMS ((bfd
*, file_ptr
*, file_ptr
*, file_ptr
*));
55 static boolean sparclinux_bfd_final_link
56 PARAMS ((bfd
*abfd
, struct bfd_link_info
*info
));
59 sparclinux_bfd_final_link (abfd
, info
)
61 struct bfd_link_info
*info
;
63 obj_aout_subformat (abfd
) = q_magic_format
;
64 return NAME(aout
,final_link
) (abfd
, info
, MY_final_link_callback
);
67 #define MY_bfd_final_link sparclinux_bfd_final_link
69 /* Set the machine type correctly. */
71 static boolean sparclinux_write_object_contents
PARAMS ((bfd
*abfd
));
74 sparclinux_write_object_contents (abfd
)
77 struct external_exec exec_bytes
;
78 struct internal_exec
*execp
= exec_hdr (abfd
);
80 N_SET_MACHTYPE (*execp
, M_SPARC
);
82 obj_reloc_entry_size (abfd
) = RELOC_STD_SIZE
;
84 WRITE_HEADERS(abfd
, execp
);
89 #define MY_write_object_contents sparclinux_write_object_contents
90 /* Code to link against Linux a.out shared libraries. */
92 /* See if a symbol name is a reference to the global offset table. */
94 #ifndef GOT_REF_PREFIX
95 #define GOT_REF_PREFIX "__GOT_"
98 #define IS_GOT_SYM(name) \
99 (strncmp (name, GOT_REF_PREFIX, sizeof GOT_REF_PREFIX - 1) == 0)
101 /* See if a symbol name is a reference to the procedure linkage table. */
103 #ifndef PLT_REF_PREFIX
104 #define PLT_REF_PREFIX "__PLT_"
107 #define IS_PLT_SYM(name) \
108 (strncmp (name, PLT_REF_PREFIX, sizeof PLT_REF_PREFIX - 1) == 0)
110 /* This string is used to generate specialized error messages. */
113 #define NEEDS_SHRLIB "__NEEDS_SHRLIB_"
116 /* This special symbol is a set vector that contains a list of
117 pointers to fixup tables. It will be present in any dynamicly
118 linked file. The linker generated fixup table should also be added
119 to the list, and it should always appear in the second slot (the
120 first one is a dummy with a magic number that is defined in
123 #ifndef SHARABLE_CONFLICTS
124 #define SHARABLE_CONFLICTS "__SHARABLE_CONFLICTS__"
127 /* We keep a list of fixups. The terminology is a bit strange, but
128 each fixup contains two 32 bit numbers. A regular fixup contains
129 an address and a pointer, and at runtime we should store the
130 address at the location pointed to by the pointer. A builtin fixup
131 contains two pointers, and we should read the address using one
132 pointer and store it at the location pointed to by the other
133 pointer. Builtin fixups come into play when we have duplicate
134 __GOT__ symbols for the same variable. The builtin fixup will copy
135 the GOT pointer from one over into the other. */
140 struct linux_link_hash_entry
*h
;
143 /* Nonzero if this is a jump instruction that needs to be fixed,
144 zero if this is just a pointer */
150 /* We don't need a special hash table entry structure, but we do need
151 to keep some information between linker passes, so we use a special
154 struct linux_link_hash_entry
156 struct aout_link_hash_entry root
;
159 struct linux_link_hash_table
161 struct aout_link_hash_table root
;
163 /* First dynamic object found in link. */
166 /* Number of fixups. */
169 /* Number of builtin fixups. */
170 size_t local_builtins
;
172 /* List of fixups. */
173 struct fixup
*fixup_list
;
176 static struct bfd_hash_entry
*linux_link_hash_newfunc
177 PARAMS ((struct bfd_hash_entry
*, struct bfd_hash_table
*, const char *));
178 static struct bfd_link_hash_table
*linux_link_hash_table_create
180 static struct fixup
*new_fixup
181 PARAMS ((struct bfd_link_info
*, struct linux_link_hash_entry
*,
183 static boolean linux_link_create_dynamic_sections
184 PARAMS ((bfd
*, struct bfd_link_info
*));
185 static boolean linux_add_one_symbol
186 PARAMS ((struct bfd_link_info
*, bfd
*, const char *, flagword
, asection
*,
187 bfd_vma
, const char *, boolean
, boolean
,
188 struct bfd_link_hash_entry
**));
189 static boolean linux_tally_symbols
190 PARAMS ((struct linux_link_hash_entry
*, PTR
));
191 static boolean linux_finish_dynamic_link
192 PARAMS ((bfd
*, struct bfd_link_info
*));
194 /* Routine to create an entry in an Linux link hash table. */
196 static struct bfd_hash_entry
*
197 linux_link_hash_newfunc (entry
, table
, string
)
198 struct bfd_hash_entry
*entry
;
199 struct bfd_hash_table
*table
;
202 struct linux_link_hash_entry
*ret
= (struct linux_link_hash_entry
*) entry
;
204 /* Allocate the structure if it has not already been allocated by a
206 if (ret
== (struct linux_link_hash_entry
*) NULL
)
207 ret
= ((struct linux_link_hash_entry
*)
208 bfd_hash_allocate (table
, sizeof (struct linux_link_hash_entry
)));
210 return (struct bfd_hash_entry
*) ret
;
212 /* Call the allocation method of the superclass. */
213 ret
= ((struct linux_link_hash_entry
*)
214 NAME(aout
,link_hash_newfunc
) ((struct bfd_hash_entry
*) ret
,
218 /* Set local fields; there aren't any. */
221 return (struct bfd_hash_entry
*) ret
;
224 /* Create a Linux link hash table. */
226 static struct bfd_link_hash_table
*
227 linux_link_hash_table_create (abfd
)
230 struct linux_link_hash_table
*ret
;
231 bfd_size_type amt
= sizeof (struct linux_link_hash_table
);
233 ret
= (struct linux_link_hash_table
*) bfd_alloc (abfd
, amt
);
234 if (ret
== (struct linux_link_hash_table
*) NULL
)
235 return (struct bfd_link_hash_table
*) NULL
;
236 if (! NAME(aout
,link_hash_table_init
) (&ret
->root
, abfd
,
237 linux_link_hash_newfunc
))
240 return (struct bfd_link_hash_table
*) NULL
;
244 ret
->fixup_count
= 0;
245 ret
->local_builtins
= 0;
246 ret
->fixup_list
= NULL
;
248 return &ret
->root
.root
;
251 /* Look up an entry in a Linux link hash table. */
253 #define linux_link_hash_lookup(table, string, create, copy, follow) \
254 ((struct linux_link_hash_entry *) \
255 aout_link_hash_lookup (&(table)->root, (string), (create), (copy),\
258 /* Traverse a Linux link hash table. */
260 #define linux_link_hash_traverse(table, func, info) \
261 (aout_link_hash_traverse \
263 (boolean (*) PARAMS ((struct aout_link_hash_entry *, PTR))) (func), \
266 /* Get the Linux link hash table from the info structure. This is
269 #define linux_hash_table(p) ((struct linux_link_hash_table *) ((p)->hash))
271 /* Store the information for a new fixup. */
273 static struct fixup
*
274 new_fixup (info
, h
, value
, builtin
)
275 struct bfd_link_info
*info
;
276 struct linux_link_hash_entry
*h
;
282 f
= (struct fixup
*) bfd_hash_allocate (&info
->hash
->table
,
283 sizeof (struct fixup
));
286 f
->next
= linux_hash_table (info
)->fixup_list
;
287 linux_hash_table (info
)->fixup_list
= f
;
290 f
->builtin
= builtin
;
292 ++linux_hash_table (info
)->fixup_count
;
296 /* We come here once we realize that we are going to link to a shared
297 library. We need to create a special section that contains the
298 fixup table, and we ultimately need to add a pointer to this into
299 the set vector for SHARABLE_CONFLICTS. At this point we do not
300 know the size of the section, but that's OK - we just need to
301 create it for now. */
304 linux_link_create_dynamic_sections (abfd
, info
)
306 struct bfd_link_info
*info ATTRIBUTE_UNUSED
;
309 register asection
*s
;
311 /* Note that we set the SEC_IN_MEMORY flag. */
312 flags
= SEC_ALLOC
| SEC_LOAD
| SEC_HAS_CONTENTS
| SEC_IN_MEMORY
;
314 /* We choose to use the name ".linux-dynamic" for the fixup table.
316 s
= bfd_make_section (abfd
, ".linux-dynamic");
318 || ! bfd_set_section_flags (abfd
, s
, flags
)
319 || ! bfd_set_section_alignment (abfd
, s
, 2))
327 /* Function to add a single symbol to the linker hash table. This is
328 a wrapper around _bfd_generic_link_add_one_symbol which handles the
329 tweaking needed for dynamic linking support. */
332 linux_add_one_symbol (info
, abfd
, name
, flags
, section
, value
, string
,
333 copy
, collect
, hashp
)
334 struct bfd_link_info
*info
;
343 struct bfd_link_hash_entry
**hashp
;
345 struct linux_link_hash_entry
*h
;
348 /* Look up and see if we already have this symbol in the hash table.
349 If we do, and the defining entry is from a shared library, we
350 need to create the dynamic sections.
352 FIXME: What if abfd->xvec != info->hash->creator? We may want to
353 be able to link Linux a.out and ELF objects together, but serious
354 confusion is possible. */
358 if (! info
->relocateable
359 && linux_hash_table (info
)->dynobj
== NULL
360 && strcmp (name
, SHARABLE_CONFLICTS
) == 0
361 && (flags
& BSF_CONSTRUCTOR
) != 0
362 && abfd
->xvec
== info
->hash
->creator
)
364 if (! linux_link_create_dynamic_sections (abfd
, info
))
366 linux_hash_table (info
)->dynobj
= abfd
;
370 if (bfd_is_abs_section (section
)
371 && abfd
->xvec
== info
->hash
->creator
)
373 h
= linux_link_hash_lookup (linux_hash_table (info
), name
, false,
376 && (h
->root
.root
.type
== bfd_link_hash_defined
377 || h
->root
.root
.type
== bfd_link_hash_defweak
))
382 *hashp
= (struct bfd_link_hash_entry
*) h
;
384 f
= new_fixup (info
, h
, value
, ! IS_PLT_SYM (name
));
387 f
->jump
= IS_PLT_SYM (name
);
393 /* Do the usual procedure for adding a symbol. */
394 if (! _bfd_generic_link_add_one_symbol (info
, abfd
, name
, flags
, section
,
395 value
, string
, copy
, collect
,
399 /* Insert a pointer to our table in the set vector. The dynamic
400 linker requires this information */
405 /* Here we do our special thing to add the pointer to the
406 dynamic section in the SHARABLE_CONFLICTS set vector. */
407 s
= bfd_get_section_by_name (linux_hash_table (info
)->dynobj
,
409 BFD_ASSERT (s
!= NULL
);
411 if (! (_bfd_generic_link_add_one_symbol
412 (info
, linux_hash_table (info
)->dynobj
, SHARABLE_CONFLICTS
,
413 BSF_GLOBAL
| BSF_CONSTRUCTOR
, s
, (bfd_vma
) 0, NULL
,
414 false, false, NULL
)))
421 /* We will crawl the hash table and come here for every global symbol.
422 We will examine each entry and see if there are indications that we
423 need to add a fixup. There are two possible cases - one is where
424 you have duplicate definitions of PLT or GOT symbols - these will
425 have already been caught and added as "builtin" fixups. If we find
426 that the corresponding non PLT/GOT symbol is also present, we
427 convert it to a regular fixup instead.
429 This function is called via linux_link_hash_traverse. */
432 linux_tally_symbols (h
, data
)
433 struct linux_link_hash_entry
*h
;
436 struct bfd_link_info
*info
= (struct bfd_link_info
*) data
;
437 struct fixup
*f
, *f1
;
439 struct linux_link_hash_entry
*h1
, *h2
;
442 if (h
->root
.root
.type
== bfd_link_hash_undefined
443 && strncmp (h
->root
.root
.root
.string
, NEEDS_SHRLIB
,
444 sizeof NEEDS_SHRLIB
- 1) == 0)
450 name
= h
->root
.root
.root
.string
+ sizeof NEEDS_SHRLIB
- 1;
451 p
= strrchr (name
, '_');
453 alloc
= (char *) bfd_malloc ((bfd_size_type
) strlen (name
) + 1);
455 if (p
== NULL
|| alloc
== NULL
)
456 (*_bfd_error_handler
) (_("Output file requires shared library `%s'\n"),
460 strcpy (alloc
, name
);
461 p
= strrchr (alloc
, '_');
463 (*_bfd_error_handler
)
464 (_("Output file requires shared library `%s.so.%s'\n"),
472 /* If this symbol is not a PLT/GOT, we do not even need to look at
474 is_plt
= IS_PLT_SYM (h
->root
.root
.root
.string
);
476 if (is_plt
|| IS_GOT_SYM (h
->root
.root
.root
.string
))
478 /* Look up this symbol twice. Once just as a regular lookup,
479 and then again following all of the indirect links until we
480 reach a real symbol. */
481 h1
= linux_link_hash_lookup (linux_hash_table (info
),
482 (h
->root
.root
.root
.string
483 + sizeof PLT_REF_PREFIX
- 1),
485 /* h2 does not follow indirect symbols. */
486 h2
= linux_link_hash_lookup (linux_hash_table (info
),
487 (h
->root
.root
.root
.string
488 + sizeof PLT_REF_PREFIX
- 1),
489 false, false, false);
491 /* The real symbol must exist but if it is also an ABS symbol,
492 there is no need to have a fixup. This is because they both
493 came from the same library. If on the other hand, we had to
494 use an indirect symbol to get to the real symbol, we add the
495 fixup anyway, since there are cases where these symbols come
496 from different shared libraries */
498 && (((h1
->root
.root
.type
== bfd_link_hash_defined
499 || h1
->root
.root
.type
== bfd_link_hash_defweak
)
500 && ! bfd_is_abs_section (h1
->root
.root
.u
.def
.section
))
501 || h2
->root
.root
.type
== bfd_link_hash_indirect
))
503 /* See if there is a "builtin" fixup already present
504 involving this symbol. If so, convert it to a regular
505 fixup. In the end, this relaxes some of the requirements
506 about the order of performing fixups. */
508 for (f1
= linux_hash_table (info
)->fixup_list
;
512 if ((f1
->h
!= h
&& f1
->h
!= h1
)
513 || (! f1
->builtin
&& ! f1
->jump
))
518 && bfd_is_abs_section (h
->root
.root
.u
.def
.section
))
520 f
= new_fixup (info
, h1
, f1
->h
->root
.root
.u
.def
.value
, 0);
529 && bfd_is_abs_section (h
->root
.root
.u
.def
.section
))
531 f
= new_fixup (info
, h1
, h
->root
.root
.u
.def
.value
, 0);
534 /* FIXME: No way to return error. */
541 /* Quick and dirty way of stripping these symbols from the
543 if (bfd_is_abs_section (h
->root
.root
.u
.def
.section
))
544 h
->root
.written
= true;
550 /* This is called to set the size of the .linux-dynamic section is.
551 It is called by the Linux linker emulation before_allocation
552 routine. We have finished reading all of the input files, and now
553 we just scan the hash tables to find out how many additional fixups
557 bfd_sparclinux_size_dynamic_sections (output_bfd
, info
)
559 struct bfd_link_info
*info
;
564 if (output_bfd
->xvec
!= &MY(vec
))
567 /* First find the fixups... */
568 linux_link_hash_traverse (linux_hash_table (info
),
572 /* If there are builtin fixups, leave room for a marker. This is
573 used by the dynamic linker so that it knows that all that follow
574 are builtin fixups instead of regular fixups. */
575 for (f
= linux_hash_table (info
)->fixup_list
; f
!= NULL
; f
= f
->next
)
579 ++linux_hash_table (info
)->fixup_count
;
580 ++linux_hash_table (info
)->local_builtins
;
585 if (linux_hash_table (info
)->dynobj
== NULL
)
587 if (linux_hash_table (info
)->fixup_count
> 0)
592 /* Allocate memory for our fixup table. We will fill it in later. */
593 s
= bfd_get_section_by_name (linux_hash_table (info
)->dynobj
,
597 s
->_raw_size
= linux_hash_table (info
)->fixup_count
+ 1;
599 s
->contents
= (bfd_byte
*) bfd_alloc (output_bfd
, s
->_raw_size
);
600 if (s
->contents
== NULL
)
602 memset (s
->contents
, 0, (size_t) s
->_raw_size
);
608 /* We come here once we are ready to actually write the fixup table to
609 the output file. Scan the fixup tables and so forth and generate
610 the stuff we need. */
613 linux_finish_dynamic_link (output_bfd
, info
)
615 struct bfd_link_info
*info
;
617 asection
*s
, *os
, *is
;
618 bfd_byte
*fixup_table
;
619 struct linux_link_hash_entry
*h
;
621 unsigned int new_addr
;
623 unsigned int fixups_written
;
625 if (linux_hash_table (info
)->dynobj
== NULL
)
628 s
= bfd_get_section_by_name (linux_hash_table (info
)->dynobj
,
630 BFD_ASSERT (s
!= NULL
);
631 os
= s
->output_section
;
634 #ifdef LINUX_LINK_DEBUG
635 printf ("Fixup table file offset: %x VMA: %x\n",
636 os
->filepos
+ s
->output_offset
,
637 os
->vma
+ s
->output_offset
);
640 fixup_table
= s
->contents
;
641 bfd_put_32 (output_bfd
,
642 (bfd_vma
) linux_hash_table (info
)->fixup_count
, fixup_table
);
645 /* Fill in fixup table. */
646 for (f
= linux_hash_table (info
)->fixup_list
; f
!= NULL
; f
= f
->next
)
651 if (f
->h
->root
.root
.type
!= bfd_link_hash_defined
652 && f
->h
->root
.root
.type
!= bfd_link_hash_defweak
)
654 (*_bfd_error_handler
)
655 (_("Symbol %s not defined for fixups\n"),
656 f
->h
->root
.root
.root
.string
);
660 is
= f
->h
->root
.root
.u
.def
.section
;
661 section_offset
= is
->output_section
->vma
+ is
->output_offset
;
662 new_addr
= f
->h
->root
.root
.u
.def
.value
+ section_offset
;
664 #ifdef LINUX_LINK_DEBUG
665 printf ("Fixup(%d) %s: %x %x\n",f
->jump
, f
->h
->root
.root
.string
,
671 /* Relative address */
672 new_addr
= new_addr
- (f
->value
+ 5);
673 bfd_put_32 (output_bfd
, (bfd_vma
) new_addr
, fixup_table
);
675 bfd_put_32 (output_bfd
, f
->value
+ 1, fixup_table
);
680 bfd_put_32 (output_bfd
, (bfd_vma
) new_addr
, fixup_table
);
682 bfd_put_32 (output_bfd
, f
->value
, fixup_table
);
688 if (linux_hash_table (info
)->local_builtins
!= 0)
690 /* Special marker so we know to switch to the other type of fixup */
691 bfd_put_32 (output_bfd
, (bfd_vma
) 0, fixup_table
);
693 bfd_put_32 (output_bfd
, (bfd_vma
) 0, fixup_table
);
696 for (f
= linux_hash_table (info
)->fixup_list
; f
!= NULL
; f
= f
->next
)
701 if (f
->h
->root
.root
.type
!= bfd_link_hash_defined
702 && f
->h
->root
.root
.type
!= bfd_link_hash_defweak
)
704 (*_bfd_error_handler
)
705 (_("Symbol %s not defined for fixups\n"),
706 f
->h
->root
.root
.root
.string
);
710 is
= f
->h
->root
.root
.u
.def
.section
;
711 section_offset
= is
->output_section
->vma
+ is
->output_offset
;
712 new_addr
= f
->h
->root
.root
.u
.def
.value
+ section_offset
;
714 #ifdef LINUX_LINK_DEBUG
715 printf ("Fixup(B) %s: %x %x\n", f
->h
->root
.root
.string
,
719 bfd_put_32 (output_bfd
, (bfd_vma
) new_addr
, fixup_table
);
721 bfd_put_32 (output_bfd
, f
->value
, fixup_table
);
727 if (linux_hash_table (info
)->fixup_count
!= fixups_written
)
729 (*_bfd_error_handler
) (_("Warning: fixup count mismatch\n"));
730 while (linux_hash_table (info
)->fixup_count
> fixups_written
)
732 bfd_put_32 (output_bfd
, (bfd_vma
) 0, fixup_table
);
734 bfd_put_32 (output_bfd
, (bfd_vma
) 0, fixup_table
);
740 h
= linux_link_hash_lookup (linux_hash_table (info
),
741 "__BUILTIN_FIXUPS__",
742 false, false, false);
745 && (h
->root
.root
.type
== bfd_link_hash_defined
746 || h
->root
.root
.type
== bfd_link_hash_defweak
))
748 is
= h
->root
.root
.u
.def
.section
;
749 section_offset
= is
->output_section
->vma
+ is
->output_offset
;
750 new_addr
= h
->root
.root
.u
.def
.value
+ section_offset
;
752 #ifdef LINUX_LINK_DEBUG
753 printf ("Builtin fixup table at %x\n", new_addr
);
756 bfd_put_32 (output_bfd
, (bfd_vma
) new_addr
, fixup_table
);
759 bfd_put_32 (output_bfd
, (bfd_vma
) 0, fixup_table
);
761 if (bfd_seek (output_bfd
, (file_ptr
) (os
->filepos
+ s
->output_offset
),
765 if (bfd_bwrite ((PTR
) s
->contents
, s
->_raw_size
, output_bfd
)
772 #define MY_bfd_link_hash_table_create linux_link_hash_table_create
773 #define MY_add_one_symbol linux_add_one_symbol
774 #define MY_finish_dynamic_link linux_finish_dynamic_link
776 #define MY_zmagic_contiguous 1
778 #include "aout-target.h"